xref: /illumos-gate/usr/src/uts/common/dtrace/dtrace.c (revision 2b6e762c557496a41438c0b105d604f60c593682)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 /*
30  * DTrace - Dynamic Tracing for Solaris
31  *
32  * This is the implementation of the Solaris Dynamic Tracing framework
33  * (DTrace).  The user-visible interface to DTrace is described at length in
34  * the "Solaris Dynamic Tracing Guide".  The interfaces between the libdtrace
35  * library, the in-kernel DTrace framework, and the DTrace providers are
36  * described in the block comments in the <sys/dtrace.h> header file.  The
37  * internal architecture of DTrace is described in the block comments in the
38  * <sys/dtrace_impl.h> header file.  The comments contained within the DTrace
39  * implementation very much assume mastery of all of these sources; if one has
40  * an unanswered question about the implementation, one should consult them
41  * first.
42  *
43  * The functions here are ordered roughly as follows:
44  *
45  *   - Probe context functions
46  *   - Probe hashing functions
47  *   - Non-probe context utility functions
48  *   - Matching functions
49  *   - Provider-to-Framework API functions
50  *   - Probe management functions
51  *   - DIF object functions
52  *   - Format functions
53  *   - Predicate functions
54  *   - ECB functions
55  *   - Buffer functions
56  *   - Enabling functions
57  *   - DOF functions
58  *   - Anonymous enabling functions
59  *   - Consumer state functions
60  *   - Helper functions
61  *   - Hook functions
62  *   - Driver cookbook functions
63  *
64  * Each group of functions begins with a block comment labelled the "DTrace
65  * [Group] Functions", allowing one to find each block by searching forward
66  * on capital-f functions.
67  */
68 #include <sys/errno.h>
69 #include <sys/stat.h>
70 #include <sys/modctl.h>
71 #include <sys/conf.h>
72 #include <sys/systm.h>
73 #include <sys/ddi.h>
74 #include <sys/sunddi.h>
75 #include <sys/cpuvar.h>
76 #include <sys/kmem.h>
77 #include <sys/strsubr.h>
78 #include <sys/sysmacros.h>
79 #include <sys/dtrace_impl.h>
80 #include <sys/atomic.h>
81 #include <sys/cmn_err.h>
82 #include <sys/mutex_impl.h>
83 #include <sys/rwlock_impl.h>
84 #include <sys/ctf_api.h>
85 #include <sys/panic.h>
86 #include <sys/priv_impl.h>
87 #include <sys/policy.h>
88 #include <sys/cred_impl.h>
89 #include <sys/procfs_isa.h>
90 #include <sys/taskq.h>
91 #include <sys/mkdev.h>
92 #include <sys/kdi.h>
93 #include <sys/zone.h>
94 
95 /*
96  * DTrace Tunable Variables
97  *
98  * The following variables may be tuned by adding a line to /etc/system that
99  * includes both the name of the DTrace module ("dtrace") and the name of the
100  * variable.  For example:
101  *
102  *   set dtrace:dtrace_destructive_disallow = 1
103  *
104  * In general, the only variables that one should be tuning this way are those
105  * that affect system-wide DTrace behavior, and for which the default behavior
106  * is undesirable.  Most of these variables are tunable on a per-consumer
107  * basis using DTrace options, and need not be tuned on a system-wide basis.
108  * When tuning these variables, avoid pathological values; while some attempt
109  * is made to verify the integrity of these variables, they are not considered
110  * part of the supported interface to DTrace, and they are therefore not
111  * checked comprehensively.  Further, these variables should not be tuned
112  * dynamically via "mdb -kw" or other means; they should only be tuned via
113  * /etc/system.
114  */
115 int		dtrace_destructive_disallow = 0;
116 dtrace_optval_t	dtrace_nonroot_maxsize = (16 * 1024 * 1024);
117 size_t		dtrace_difo_maxsize = (256 * 1024);
118 dtrace_optval_t	dtrace_dof_maxsize = (256 * 1024);
119 size_t		dtrace_global_maxsize = (16 * 1024);
120 size_t		dtrace_actions_max = (16 * 1024);
121 size_t		dtrace_retain_max = 1024;
122 dtrace_optval_t	dtrace_helper_actions_max = 32;
123 dtrace_optval_t	dtrace_helper_providers_max = 32;
124 dtrace_optval_t	dtrace_dstate_defsize = (1 * 1024 * 1024);
125 size_t		dtrace_strsize_default = 256;
126 dtrace_optval_t	dtrace_cleanrate_default = 9900990;		/* 101 hz */
127 dtrace_optval_t	dtrace_cleanrate_min = 200000;			/* 5000 hz */
128 dtrace_optval_t	dtrace_cleanrate_max = (uint64_t)60 * NANOSEC;	/* 1/minute */
129 dtrace_optval_t	dtrace_aggrate_default = NANOSEC;		/* 1 hz */
130 dtrace_optval_t	dtrace_statusrate_default = NANOSEC;		/* 1 hz */
131 dtrace_optval_t dtrace_statusrate_max = (hrtime_t)10 * NANOSEC;	 /* 6/minute */
132 dtrace_optval_t	dtrace_switchrate_default = NANOSEC;		/* 1 hz */
133 dtrace_optval_t	dtrace_nspec_default = 1;
134 dtrace_optval_t	dtrace_specsize_default = 32 * 1024;
135 dtrace_optval_t dtrace_stackframes_default = 20;
136 dtrace_optval_t dtrace_ustackframes_default = 20;
137 dtrace_optval_t dtrace_jstackframes_default = 50;
138 dtrace_optval_t dtrace_jstackstrsize_default = 512;
139 int		dtrace_msgdsize_max = 128;
140 hrtime_t	dtrace_chill_max = 500 * (NANOSEC / MILLISEC);	/* 500 ms */
141 hrtime_t	dtrace_chill_interval = NANOSEC;		/* 1000 ms */
142 int		dtrace_devdepth_max = 32;
143 int		dtrace_err_verbose;
144 hrtime_t	dtrace_deadman_interval = NANOSEC;
145 hrtime_t	dtrace_deadman_timeout = (hrtime_t)10 * NANOSEC;
146 hrtime_t	dtrace_deadman_user = (hrtime_t)30 * NANOSEC;
147 
148 /*
149  * DTrace External Variables
150  *
151  * As dtrace(7D) is a kernel module, any DTrace variables are obviously
152  * available to DTrace consumers via the backtick (`) syntax.  One of these,
153  * dtrace_zero, is made deliberately so:  it is provided as a source of
154  * well-known, zero-filled memory.  While this variable is not documented,
155  * it is used by some translators as an implementation detail.
156  */
157 const char	dtrace_zero[256] = { 0 };	/* zero-filled memory */
158 
159 /*
160  * DTrace Internal Variables
161  */
162 static dev_info_t	*dtrace_devi;		/* device info */
163 static vmem_t		*dtrace_arena;		/* probe ID arena */
164 static vmem_t		*dtrace_minor;		/* minor number arena */
165 static taskq_t		*dtrace_taskq;		/* task queue */
166 static dtrace_probe_t	**dtrace_probes;	/* array of all probes */
167 static int		dtrace_nprobes;		/* number of probes */
168 static dtrace_provider_t *dtrace_provider;	/* provider list */
169 static dtrace_meta_t	*dtrace_meta_pid;	/* user-land meta provider */
170 static int		dtrace_opens;		/* number of opens */
171 static int		dtrace_helpers;		/* number of helpers */
172 static void		*dtrace_softstate;	/* softstate pointer */
173 static dtrace_hash_t	*dtrace_bymod;		/* probes hashed by module */
174 static dtrace_hash_t	*dtrace_byfunc;		/* probes hashed by function */
175 static dtrace_hash_t	*dtrace_byname;		/* probes hashed by name */
176 static dtrace_toxrange_t *dtrace_toxrange;	/* toxic range array */
177 static int		dtrace_toxranges;	/* number of toxic ranges */
178 static int		dtrace_toxranges_max;	/* size of toxic range array */
179 static dtrace_anon_t	dtrace_anon;		/* anonymous enabling */
180 static kmem_cache_t	*dtrace_state_cache;	/* cache for dynamic state */
181 static uint64_t		dtrace_vtime_references; /* number of vtimestamp refs */
182 static kthread_t	*dtrace_panicked;	/* panicking thread */
183 static dtrace_ecb_t	*dtrace_ecb_create_cache; /* cached created ECB */
184 static dtrace_genid_t	dtrace_probegen;	/* current probe generation */
185 static dtrace_helpers_t *dtrace_deferred_pid;	/* deferred helper list */
186 static dtrace_enabling_t *dtrace_retained;	/* list of retained enablings */
187 static dtrace_dynvar_t	dtrace_dynhash_sink;	/* end of dynamic hash chains */
188 
189 /*
190  * DTrace Locking
191  * DTrace is protected by three (relatively coarse-grained) locks:
192  *
193  * (1) dtrace_lock is required to manipulate essentially any DTrace state,
194  *     including enabling state, probes, ECBs, consumer state, helper state,
195  *     etc.  Importantly, dtrace_lock is _not_ required when in probe context;
196  *     probe context is lock-free -- synchronization is handled via the
197  *     dtrace_sync() cross call mechanism.
198  *
199  * (2) dtrace_provider_lock is required when manipulating provider state, or
200  *     when provider state must be held constant.
201  *
202  * (3) dtrace_meta_lock is required when manipulating meta provider state, or
203  *     when meta provider state must be held constant.
204  *
205  * The lock ordering between these three locks is dtrace_meta_lock before
206  * dtrace_provider_lock before dtrace_lock.  (In particular, there are
207  * several places where dtrace_provider_lock is held by the framework as it
208  * calls into the providers -- which then call back into the framework,
209  * grabbing dtrace_lock.)
210  *
211  * There are two other locks in the mix:  mod_lock and cpu_lock.  With respect
212  * to dtrace_provider_lock and dtrace_lock, cpu_lock continues its historical
213  * role as a coarse-grained lock; it is acquired before both of these locks.
214  * With respect to dtrace_meta_lock, its behavior is stranger:  cpu_lock must
215  * be acquired _between_ dtrace_meta_lock and any other DTrace locks.
216  * mod_lock is similar with respect to dtrace_provider_lock in that it must be
217  * acquired _between_ dtrace_provider_lock and dtrace_lock.
218  */
219 static kmutex_t		dtrace_lock;		/* probe state lock */
220 static kmutex_t		dtrace_provider_lock;	/* provider state lock */
221 static kmutex_t		dtrace_meta_lock;	/* meta-provider state lock */
222 
223 /*
224  * DTrace Provider Variables
225  *
226  * These are the variables relating to DTrace as a provider (that is, the
227  * provider of the BEGIN, END, and ERROR probes).
228  */
229 static dtrace_pattr_t	dtrace_provider_attr = {
230 { DTRACE_STABILITY_STABLE, DTRACE_STABILITY_STABLE, DTRACE_CLASS_COMMON },
231 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
232 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
233 { DTRACE_STABILITY_STABLE, DTRACE_STABILITY_STABLE, DTRACE_CLASS_COMMON },
234 { DTRACE_STABILITY_STABLE, DTRACE_STABILITY_STABLE, DTRACE_CLASS_COMMON },
235 };
236 
237 static void
238 dtrace_nullop(void)
239 {}
240 
241 static dtrace_pops_t	dtrace_provider_ops = {
242 	(void (*)(void *, const dtrace_probedesc_t *))dtrace_nullop,
243 	(void (*)(void *, struct modctl *))dtrace_nullop,
244 	(void (*)(void *, dtrace_id_t, void *))dtrace_nullop,
245 	(void (*)(void *, dtrace_id_t, void *))dtrace_nullop,
246 	(void (*)(void *, dtrace_id_t, void *))dtrace_nullop,
247 	(void (*)(void *, dtrace_id_t, void *))dtrace_nullop,
248 	NULL,
249 	NULL,
250 	NULL,
251 	(void (*)(void *, dtrace_id_t, void *))dtrace_nullop
252 };
253 
254 static dtrace_id_t	dtrace_probeid_begin;	/* special BEGIN probe */
255 static dtrace_id_t	dtrace_probeid_end;	/* special END probe */
256 dtrace_id_t		dtrace_probeid_error;	/* special ERROR probe */
257 
258 /*
259  * DTrace Helper Tracing Variables
260  */
261 uint32_t dtrace_helptrace_next = 0;
262 uint32_t dtrace_helptrace_nlocals;
263 char	*dtrace_helptrace_buffer;
264 int	dtrace_helptrace_bufsize = 512 * 1024;
265 
266 #ifdef DEBUG
267 int	dtrace_helptrace_enabled = 1;
268 #else
269 int	dtrace_helptrace_enabled = 0;
270 #endif
271 
272 /*
273  * DTrace Error Hashing
274  *
275  * On DEBUG kernels, DTrace will track the errors that has seen in a hash
276  * table.  This is very useful for checking coverage of tests that are
277  * expected to induce DIF or DOF processing errors, and may be useful for
278  * debugging problems in the DIF code generator or in DOF generation .  The
279  * error hash may be examined with the ::dtrace_errhash MDB dcmd.
280  */
281 #ifdef DEBUG
282 static dtrace_errhash_t	dtrace_errhash[DTRACE_ERRHASHSZ];
283 static const char *dtrace_errlast;
284 static kthread_t *dtrace_errthread;
285 static kmutex_t dtrace_errlock;
286 #endif
287 
288 /*
289  * DTrace Macros and Constants
290  *
291  * These are various macros that are useful in various spots in the
292  * implementation, along with a few random constants that have no meaning
293  * outside of the implementation.  There is no real structure to this cpp
294  * mishmash -- but is there ever?
295  */
296 #define	DTRACE_HASHSTR(hash, probe)	\
297 	dtrace_hash_str(*((char **)((uintptr_t)(probe) + (hash)->dth_stroffs)))
298 
299 #define	DTRACE_HASHNEXT(hash, probe)	\
300 	(dtrace_probe_t **)((uintptr_t)(probe) + (hash)->dth_nextoffs)
301 
302 #define	DTRACE_HASHPREV(hash, probe)	\
303 	(dtrace_probe_t **)((uintptr_t)(probe) + (hash)->dth_prevoffs)
304 
305 #define	DTRACE_HASHEQ(hash, lhs, rhs)	\
306 	(strcmp(*((char **)((uintptr_t)(lhs) + (hash)->dth_stroffs)), \
307 	    *((char **)((uintptr_t)(rhs) + (hash)->dth_stroffs))) == 0)
308 
309 #define	DTRACE_AGGHASHSIZE_SLEW		17
310 
311 /*
312  * The key for a thread-local variable consists of the lower 61 bits of the
313  * t_did, plus the 3 bits of the highest active interrupt above LOCK_LEVEL.
314  * We add DIF_VARIABLE_MAX to t_did to assure that the thread key is never
315  * equal to a variable identifier.  This is necessary (but not sufficient) to
316  * assure that global associative arrays never collide with thread-local
317  * variables.  To guarantee that they cannot collide, we must also define the
318  * order for keying dynamic variables.  That order is:
319  *
320  *   [ key0 ] ... [ keyn ] [ variable-key ] [ tls-key ]
321  *
322  * Because the variable-key and the tls-key are in orthogonal spaces, there is
323  * no way for a global variable key signature to match a thread-local key
324  * signature.
325  */
326 #define	DTRACE_TLS_THRKEY(where) { \
327 	uint_t intr = 0; \
328 	uint_t actv = CPU->cpu_intr_actv >> (LOCK_LEVEL + 1); \
329 	for (; actv; actv >>= 1) \
330 		intr++; \
331 	ASSERT(intr < (1 << 3)); \
332 	(where) = ((curthread->t_did + DIF_VARIABLE_MAX) & \
333 	    (((uint64_t)1 << 61) - 1)) | ((uint64_t)intr << 61); \
334 }
335 
336 #define	DT_BSWAP_8(x)	((x) & 0xff)
337 #define	DT_BSWAP_16(x)	((DT_BSWAP_8(x) << 8) | DT_BSWAP_8((x) >> 8))
338 #define	DT_BSWAP_32(x)	((DT_BSWAP_16(x) << 16) | DT_BSWAP_16((x) >> 16))
339 #define	DT_BSWAP_64(x)	((DT_BSWAP_32(x) << 32) | DT_BSWAP_32((x) >> 32))
340 
341 #define	DTRACE_STORE(type, tomax, offset, what) \
342 	*((type *)((uintptr_t)(tomax) + (uintptr_t)offset)) = (type)(what);
343 
344 #ifndef __i386
345 #define	DTRACE_ALIGNCHECK(addr, size, flags)				\
346 	if (addr & (size - 1)) {					\
347 		*flags |= CPU_DTRACE_BADALIGN;				\
348 		cpu_core[CPU->cpu_id].cpuc_dtrace_illval = addr;	\
349 		return (0);						\
350 	}
351 #else
352 #define	DTRACE_ALIGNCHECK(addr, size, flags)
353 #endif
354 
355 #define	DTRACE_LOADFUNC(bits)						\
356 /*CSTYLED*/								\
357 uint##bits##_t								\
358 dtrace_load##bits(uintptr_t addr)					\
359 {									\
360 	size_t size = bits / NBBY;					\
361 	/*CSTYLED*/							\
362 	uint##bits##_t rval;						\
363 	int i;								\
364 	volatile uint16_t *flags = (volatile uint16_t *)		\
365 	    &cpu_core[CPU->cpu_id].cpuc_dtrace_flags;			\
366 									\
367 	DTRACE_ALIGNCHECK(addr, size, flags);				\
368 									\
369 	for (i = 0; i < dtrace_toxranges; i++) {			\
370 		if (addr >= dtrace_toxrange[i].dtt_limit)		\
371 			continue;					\
372 									\
373 		if (addr + size <= dtrace_toxrange[i].dtt_base)		\
374 			continue;					\
375 									\
376 		/*							\
377 		 * This address falls within a toxic region; return 0.	\
378 		 */							\
379 		*flags |= CPU_DTRACE_BADADDR;				\
380 		cpu_core[CPU->cpu_id].cpuc_dtrace_illval = addr;	\
381 		return (0);						\
382 	}								\
383 									\
384 	*flags |= CPU_DTRACE_NOFAULT;					\
385 	/*CSTYLED*/							\
386 	rval = *((volatile uint##bits##_t *)addr);			\
387 	*flags &= ~CPU_DTRACE_NOFAULT;					\
388 									\
389 	return (rval);							\
390 }
391 
392 #ifdef _LP64
393 #define	dtrace_loadptr	dtrace_load64
394 #else
395 #define	dtrace_loadptr	dtrace_load32
396 #endif
397 
398 #define	DTRACE_DYNHASH_FREE	0
399 #define	DTRACE_DYNHASH_SINK	1
400 #define	DTRACE_DYNHASH_VALID	2
401 
402 #define	DTRACE_MATCH_NEXT	0
403 #define	DTRACE_MATCH_DONE	1
404 #define	DTRACE_ANCHORED(probe)	((probe)->dtpr_func[0] != '\0')
405 #define	DTRACE_STATE_ALIGN	64
406 
407 #define	DTRACE_FLAGS2FLT(flags)						\
408 	(((flags) & CPU_DTRACE_BADADDR) ? DTRACEFLT_BADADDR :		\
409 	((flags) & CPU_DTRACE_ILLOP) ? DTRACEFLT_ILLOP :		\
410 	((flags) & CPU_DTRACE_DIVZERO) ? DTRACEFLT_DIVZERO :		\
411 	((flags) & CPU_DTRACE_KPRIV) ? DTRACEFLT_KPRIV :		\
412 	((flags) & CPU_DTRACE_UPRIV) ? DTRACEFLT_UPRIV :		\
413 	((flags) & CPU_DTRACE_TUPOFLOW) ?  DTRACEFLT_TUPOFLOW :		\
414 	((flags) & CPU_DTRACE_BADALIGN) ?  DTRACEFLT_BADALIGN :		\
415 	((flags) & CPU_DTRACE_NOSCRATCH) ?  DTRACEFLT_NOSCRATCH :	\
416 	DTRACEFLT_UNKNOWN)
417 
418 #define	DTRACEACT_ISSTRING(act)						\
419 	((act)->dta_kind == DTRACEACT_DIFEXPR &&			\
420 	(act)->dta_difo->dtdo_rtype.dtdt_kind == DIF_TYPE_STRING)
421 
422 static dtrace_probe_t *dtrace_probe_lookup_id(dtrace_id_t id);
423 static void dtrace_enabling_provide(dtrace_provider_t *);
424 static int dtrace_enabling_match(dtrace_enabling_t *, int *);
425 static void dtrace_enabling_matchall(void);
426 static dtrace_state_t *dtrace_anon_grab(void);
427 static uint64_t dtrace_helper(int, dtrace_mstate_t *,
428     dtrace_state_t *, uint64_t, uint64_t);
429 static dtrace_helpers_t *dtrace_helpers_create(proc_t *);
430 static void dtrace_buffer_drop(dtrace_buffer_t *);
431 static intptr_t dtrace_buffer_reserve(dtrace_buffer_t *, size_t, size_t,
432     dtrace_state_t *, dtrace_mstate_t *);
433 static int dtrace_state_option(dtrace_state_t *, dtrace_optid_t,
434     dtrace_optval_t);
435 static int dtrace_ecb_create_enable(dtrace_probe_t *, void *);
436 static void dtrace_helper_provider_destroy(dtrace_helper_provider_t *);
437 
438 /*
439  * DTrace Probe Context Functions
440  *
441  * These functions are called from probe context.  Because probe context is
442  * any context in which C may be called, arbitrarily locks may be held,
443  * interrupts may be disabled, we may be in arbitrary dispatched state, etc.
444  * As a result, functions called from probe context may only call other DTrace
445  * support functions -- they may not interact at all with the system at large.
446  * (Note that the ASSERT macro is made probe-context safe by redefining it in
447  * terms of dtrace_assfail(), a probe-context safe function.) If arbitrary
448  * loads are to be performed from probe context, they _must_ be in terms of
449  * the safe dtrace_load*() variants.
450  *
451  * Some functions in this block are not actually called from probe context;
452  * for these functions, there will be a comment above the function reading
453  * "Note:  not called from probe context."
454  */
455 void
456 dtrace_panic(const char *format, ...)
457 {
458 	va_list alist;
459 
460 	va_start(alist, format);
461 	dtrace_vpanic(format, alist);
462 	va_end(alist);
463 }
464 
465 int
466 dtrace_assfail(const char *a, const char *f, int l)
467 {
468 	dtrace_panic("assertion failed: %s, file: %s, line: %d", a, f, l);
469 
470 	/*
471 	 * We just need something here that even the most clever compiler
472 	 * cannot optimize away.
473 	 */
474 	return (a[(uintptr_t)f]);
475 }
476 
477 /*
478  * Atomically increment a specified error counter from probe context.
479  */
480 static void
481 dtrace_error(uint32_t *counter)
482 {
483 	/*
484 	 * Most counters stored to in probe context are per-CPU counters.
485 	 * However, there are some error conditions that are sufficiently
486 	 * arcane that they don't merit per-CPU storage.  If these counters
487 	 * are incremented concurrently on different CPUs, scalability will be
488 	 * adversely affected -- but we don't expect them to be white-hot in a
489 	 * correctly constructed enabling...
490 	 */
491 	uint32_t oval, nval;
492 
493 	do {
494 		oval = *counter;
495 
496 		if ((nval = oval + 1) == 0) {
497 			/*
498 			 * If the counter would wrap, set it to 1 -- assuring
499 			 * that the counter is never zero when we have seen
500 			 * errors.  (The counter must be 32-bits because we
501 			 * aren't guaranteed a 64-bit compare&swap operation.)
502 			 * To save this code both the infamy of being fingered
503 			 * by a priggish news story and the indignity of being
504 			 * the target of a neo-puritan witch trial, we're
505 			 * carefully avoiding any colorful description of the
506 			 * likelihood of this condition -- but suffice it to
507 			 * say that it is only slightly more likely than the
508 			 * overflow of predicate cache IDs, as discussed in
509 			 * dtrace_predicate_create().
510 			 */
511 			nval = 1;
512 		}
513 	} while (dtrace_cas32(counter, oval, nval) != oval);
514 }
515 
516 /*
517  * Use the DTRACE_LOADFUNC macro to define functions for each of loading a
518  * uint8_t, a uint16_t, a uint32_t and a uint64_t.
519  */
520 DTRACE_LOADFUNC(8)
521 DTRACE_LOADFUNC(16)
522 DTRACE_LOADFUNC(32)
523 DTRACE_LOADFUNC(64)
524 
525 static int
526 dtrace_inscratch(uintptr_t dest, size_t size, dtrace_mstate_t *mstate)
527 {
528 	if (dest < mstate->dtms_scratch_base)
529 		return (0);
530 
531 	if (dest + size < dest)
532 		return (0);
533 
534 	if (dest + size > mstate->dtms_scratch_ptr)
535 		return (0);
536 
537 	return (1);
538 }
539 
540 static int
541 dtrace_canstore_statvar(uint64_t addr, size_t sz,
542     dtrace_statvar_t **svars, int nsvars)
543 {
544 	int i;
545 
546 	for (i = 0; i < nsvars; i++) {
547 		dtrace_statvar_t *svar = svars[i];
548 
549 		if (svar == NULL || svar->dtsv_size == 0)
550 			continue;
551 
552 		if (addr - svar->dtsv_data < svar->dtsv_size &&
553 		    addr + sz <= svar->dtsv_data + svar->dtsv_size)
554 			return (1);
555 	}
556 
557 	return (0);
558 }
559 
560 /*
561  * Check to see if the address is within a memory region to which a store may
562  * be issued.  This includes the DTrace scratch areas, and any DTrace variable
563  * region.  The caller of dtrace_canstore() is responsible for performing any
564  * alignment checks that are needed before stores are actually executed.
565  */
566 static int
567 dtrace_canstore(uint64_t addr, size_t sz, dtrace_mstate_t *mstate,
568     dtrace_vstate_t *vstate)
569 {
570 	uintptr_t a;
571 	size_t s;
572 
573 	/*
574 	 * First, check to see if the address is in scratch space...
575 	 */
576 	a = mstate->dtms_scratch_base;
577 	s = mstate->dtms_scratch_size;
578 
579 	if (addr - a < s && addr + sz <= a + s)
580 		return (1);
581 
582 	/*
583 	 * Now check to see if it's a dynamic variable.  This check will pick
584 	 * up both thread-local variables and any global dynamically-allocated
585 	 * variables.
586 	 */
587 	a = (uintptr_t)vstate->dtvs_dynvars.dtds_base;
588 	s = vstate->dtvs_dynvars.dtds_size;
589 	if (addr - a < s && addr + sz <= a + s)
590 		return (1);
591 
592 	/*
593 	 * Finally, check the static local and global variables.  These checks
594 	 * take the longest, so we perform them last.
595 	 */
596 	if (dtrace_canstore_statvar(addr, sz,
597 	    vstate->dtvs_locals, vstate->dtvs_nlocals))
598 		return (1);
599 
600 	if (dtrace_canstore_statvar(addr, sz,
601 	    vstate->dtvs_globals, vstate->dtvs_nglobals))
602 		return (1);
603 
604 	return (0);
605 }
606 
607 /*
608  * Compare two strings using safe loads.
609  */
610 static int
611 dtrace_strncmp(char *s1, char *s2, size_t limit)
612 {
613 	uint8_t c1, c2;
614 	volatile uint16_t *flags;
615 
616 	if (s1 == s2 || limit == 0)
617 		return (0);
618 
619 	flags = (volatile uint16_t *)&cpu_core[CPU->cpu_id].cpuc_dtrace_flags;
620 
621 	do {
622 		if (s1 == NULL) {
623 			c1 = '\0';
624 		} else {
625 			c1 = dtrace_load8((uintptr_t)s1++);
626 		}
627 
628 		if (s2 == NULL) {
629 			c2 = '\0';
630 		} else {
631 			c2 = dtrace_load8((uintptr_t)s2++);
632 		}
633 
634 		if (c1 != c2)
635 			return (c1 - c2);
636 	} while (--limit && c1 != '\0' && !(*flags & CPU_DTRACE_FAULT));
637 
638 	return (0);
639 }
640 
641 /*
642  * Compute strlen(s) for a string using safe memory accesses.  The additional
643  * len parameter is used to specify a maximum length to ensure completion.
644  */
645 static size_t
646 dtrace_strlen(const char *s, size_t lim)
647 {
648 	uint_t len;
649 
650 	for (len = 0; len != lim; len++) {
651 		if (dtrace_load8((uintptr_t)s++) == '\0')
652 			break;
653 	}
654 
655 	return (len);
656 }
657 
658 /*
659  * Check if an address falls within a toxic region.
660  */
661 static int
662 dtrace_istoxic(uintptr_t kaddr, size_t size)
663 {
664 	uintptr_t taddr, tsize;
665 	int i;
666 
667 	for (i = 0; i < dtrace_toxranges; i++) {
668 		taddr = dtrace_toxrange[i].dtt_base;
669 		tsize = dtrace_toxrange[i].dtt_limit - taddr;
670 
671 		if (kaddr - taddr < tsize) {
672 			DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
673 			cpu_core[CPU->cpu_id].cpuc_dtrace_illval = kaddr;
674 			return (1);
675 		}
676 
677 		if (taddr - kaddr < size) {
678 			DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
679 			cpu_core[CPU->cpu_id].cpuc_dtrace_illval = taddr;
680 			return (1);
681 		}
682 	}
683 
684 	return (0);
685 }
686 
687 /*
688  * Copy src to dst using safe memory accesses.  The src is assumed to be unsafe
689  * memory specified by the DIF program.  The dst is assumed to be safe memory
690  * that we can store to directly because it is managed by DTrace.  As with
691  * standard bcopy, overlapping copies are handled properly.
692  */
693 static void
694 dtrace_bcopy(const void *src, void *dst, size_t len)
695 {
696 	if (len != 0) {
697 		uint8_t *s1 = dst;
698 		const uint8_t *s2 = src;
699 
700 		if (s1 <= s2) {
701 			do {
702 				*s1++ = dtrace_load8((uintptr_t)s2++);
703 			} while (--len != 0);
704 		} else {
705 			s2 += len;
706 			s1 += len;
707 
708 			do {
709 				*--s1 = dtrace_load8((uintptr_t)--s2);
710 			} while (--len != 0);
711 		}
712 	}
713 }
714 
715 /*
716  * Copy src to dst using safe memory accesses, up to either the specified
717  * length, or the point that a nul byte is encountered.  The src is assumed to
718  * be unsafe memory specified by the DIF program.  The dst is assumed to be
719  * safe memory that we can store to directly because it is managed by DTrace.
720  * Unlike dtrace_bcopy(), overlapping regions are not handled.
721  */
722 static void
723 dtrace_strcpy(const void *src, void *dst, size_t len)
724 {
725 	if (len != 0) {
726 		uint8_t *s1 = dst, c;
727 		const uint8_t *s2 = src;
728 
729 		do {
730 			*s1++ = c = dtrace_load8((uintptr_t)s2++);
731 		} while (--len != 0 && c != '\0');
732 	}
733 }
734 
735 /*
736  * Copy src to dst, deriving the size and type from the specified (BYREF)
737  * variable type.  The src is assumed to be unsafe memory specified by the DIF
738  * program.  The dst is assumed to be DTrace variable memory that is of the
739  * specified type; we assume that we can store to directly.
740  */
741 static void
742 dtrace_vcopy(void *src, void *dst, dtrace_diftype_t *type)
743 {
744 	ASSERT(type->dtdt_flags & DIF_TF_BYREF);
745 
746 	if (type->dtdt_kind == DIF_TYPE_STRING) {
747 		dtrace_strcpy(src, dst, type->dtdt_size);
748 	} else {
749 		dtrace_bcopy(src, dst, type->dtdt_size);
750 	}
751 }
752 
753 /*
754  * Compare s1 to s2 using safe memory accesses.  The s1 data is assumed to be
755  * unsafe memory specified by the DIF program.  The s2 data is assumed to be
756  * safe memory that we can access directly because it is managed by DTrace.
757  */
758 static int
759 dtrace_bcmp(const void *s1, const void *s2, size_t len)
760 {
761 	volatile uint16_t *flags;
762 
763 	flags = (volatile uint16_t *)&cpu_core[CPU->cpu_id].cpuc_dtrace_flags;
764 
765 	if (s1 == s2)
766 		return (0);
767 
768 	if (s1 == NULL || s2 == NULL)
769 		return (1);
770 
771 	if (s1 != s2 && len != 0) {
772 		const uint8_t *ps1 = s1;
773 		const uint8_t *ps2 = s2;
774 
775 		do {
776 			if (dtrace_load8((uintptr_t)ps1++) != *ps2++)
777 				return (1);
778 		} while (--len != 0 && !(*flags & CPU_DTRACE_FAULT));
779 	}
780 	return (0);
781 }
782 
783 /*
784  * Zero the specified region using a simple byte-by-byte loop.  Note that this
785  * is for safe DTrace-managed memory only.
786  */
787 static void
788 dtrace_bzero(void *dst, size_t len)
789 {
790 	uchar_t *cp;
791 
792 	for (cp = dst; len != 0; len--)
793 		*cp++ = 0;
794 }
795 
796 /*
797  * This privilege check should be used by actions and subroutines to
798  * verify that the user credentials of the process that enabled the
799  * invoking ECB match the target credentials
800  */
801 static int
802 dtrace_priv_proc_common_user(dtrace_state_t *state)
803 {
804 	cred_t *cr, *s_cr = state->dts_cred.dcr_cred;
805 
806 	/*
807 	 * We should always have a non-NULL state cred here, since if cred
808 	 * is null (anonymous tracing), we fast-path bypass this routine.
809 	 */
810 	ASSERT(s_cr != NULL);
811 
812 	if ((cr = CRED()) != NULL &&
813 	    s_cr->cr_uid == cr->cr_uid &&
814 	    s_cr->cr_uid == cr->cr_ruid &&
815 	    s_cr->cr_uid == cr->cr_suid &&
816 	    s_cr->cr_gid == cr->cr_gid &&
817 	    s_cr->cr_gid == cr->cr_rgid &&
818 	    s_cr->cr_gid == cr->cr_sgid)
819 		return (1);
820 
821 	return (0);
822 }
823 
824 /*
825  * This privilege check should be used by actions and subroutines to
826  * verify that the zone of the process that enabled the invoking ECB
827  * matches the target credentials
828  */
829 static int
830 dtrace_priv_proc_common_zone(dtrace_state_t *state)
831 {
832 	cred_t *cr, *s_cr = state->dts_cred.dcr_cred;
833 
834 	/*
835 	 * We should always have a non-NULL state cred here, since if cred
836 	 * is null (anonymous tracing), we fast-path bypass this routine.
837 	 */
838 	ASSERT(s_cr != NULL);
839 
840 	if ((cr = CRED()) != NULL &&
841 	    s_cr->cr_zone == cr->cr_zone)
842 		return (1);
843 
844 	return (0);
845 }
846 
847 /*
848  * This privilege check should be used by actions and subroutines to
849  * verify that the process has not setuid or changed credentials.
850  */
851 static int
852 dtrace_priv_proc_common_nocd()
853 {
854 	proc_t *proc;
855 
856 	if ((proc = ttoproc(curthread)) != NULL &&
857 	    !(proc->p_flag & SNOCD))
858 		return (1);
859 
860 	return (0);
861 }
862 
863 static int
864 dtrace_priv_proc_destructive(dtrace_state_t *state)
865 {
866 	int action = state->dts_cred.dcr_action;
867 
868 	if (((action & DTRACE_CRA_PROC_DESTRUCTIVE_ALLZONE) == 0) &&
869 	    dtrace_priv_proc_common_zone(state) == 0)
870 		goto bad;
871 
872 	if (((action & DTRACE_CRA_PROC_DESTRUCTIVE_ALLUSER) == 0) &&
873 	    dtrace_priv_proc_common_user(state) == 0)
874 		goto bad;
875 
876 	if (((action & DTRACE_CRA_PROC_DESTRUCTIVE_CREDCHG) == 0) &&
877 	    dtrace_priv_proc_common_nocd() == 0)
878 		goto bad;
879 
880 	return (1);
881 
882 bad:
883 	cpu_core[CPU->cpu_id].cpuc_dtrace_flags |= CPU_DTRACE_UPRIV;
884 
885 	return (0);
886 }
887 
888 static int
889 dtrace_priv_proc_control(dtrace_state_t *state)
890 {
891 	if (state->dts_cred.dcr_action & DTRACE_CRA_PROC_CONTROL)
892 		return (1);
893 
894 	if (dtrace_priv_proc_common_zone(state) &&
895 	    dtrace_priv_proc_common_user(state) &&
896 	    dtrace_priv_proc_common_nocd())
897 		return (1);
898 
899 	cpu_core[CPU->cpu_id].cpuc_dtrace_flags |= CPU_DTRACE_UPRIV;
900 
901 	return (0);
902 }
903 
904 static int
905 dtrace_priv_proc(dtrace_state_t *state)
906 {
907 	if (state->dts_cred.dcr_action & DTRACE_CRA_PROC)
908 		return (1);
909 
910 	cpu_core[CPU->cpu_id].cpuc_dtrace_flags |= CPU_DTRACE_UPRIV;
911 
912 	return (0);
913 }
914 
915 static int
916 dtrace_priv_kernel(dtrace_state_t *state)
917 {
918 	if (state->dts_cred.dcr_action & DTRACE_CRA_KERNEL)
919 		return (1);
920 
921 	cpu_core[CPU->cpu_id].cpuc_dtrace_flags |= CPU_DTRACE_KPRIV;
922 
923 	return (0);
924 }
925 
926 static int
927 dtrace_priv_kernel_destructive(dtrace_state_t *state)
928 {
929 	if (state->dts_cred.dcr_action & DTRACE_CRA_KERNEL_DESTRUCTIVE)
930 		return (1);
931 
932 	cpu_core[CPU->cpu_id].cpuc_dtrace_flags |= CPU_DTRACE_KPRIV;
933 
934 	return (0);
935 }
936 
937 /*
938  * Note:  not called from probe context.  This function is called
939  * asynchronously (and at a regular interval) from outside of probe context to
940  * clean the dirty dynamic variable lists on all CPUs.  Dynamic variable
941  * cleaning is explained in detail in <sys/dtrace_impl.h>.
942  */
943 void
944 dtrace_dynvar_clean(dtrace_dstate_t *dstate)
945 {
946 	dtrace_dynvar_t *dirty;
947 	dtrace_dstate_percpu_t *dcpu;
948 	int i, work = 0;
949 
950 	for (i = 0; i < NCPU; i++) {
951 		dcpu = &dstate->dtds_percpu[i];
952 
953 		ASSERT(dcpu->dtdsc_rinsing == NULL);
954 
955 		/*
956 		 * If the dirty list is NULL, there is no dirty work to do.
957 		 */
958 		if (dcpu->dtdsc_dirty == NULL)
959 			continue;
960 
961 		/*
962 		 * If the clean list is non-NULL, then we're not going to do
963 		 * any work for this CPU -- it means that there has not been
964 		 * a dtrace_dynvar() allocation on this CPU (or from this CPU)
965 		 * since the last time we cleaned house.
966 		 */
967 		if (dcpu->dtdsc_clean != NULL)
968 			continue;
969 
970 		work = 1;
971 
972 		/*
973 		 * Atomically move the dirty list aside.
974 		 */
975 		do {
976 			dirty = dcpu->dtdsc_dirty;
977 
978 			/*
979 			 * Before we zap the dirty list, set the rinsing list.
980 			 * (This allows for a potential assertion in
981 			 * dtrace_dynvar():  if a free dynamic variable appears
982 			 * on a hash chain, either the dirty list or the
983 			 * rinsing list for some CPU must be non-NULL.)
984 			 */
985 			dcpu->dtdsc_rinsing = dirty;
986 			dtrace_membar_producer();
987 		} while (dtrace_casptr(&dcpu->dtdsc_dirty,
988 		    dirty, NULL) != dirty);
989 	}
990 
991 	if (!work) {
992 		/*
993 		 * We have no work to do; we can simply return.
994 		 */
995 		return;
996 	}
997 
998 	dtrace_sync();
999 
1000 	for (i = 0; i < NCPU; i++) {
1001 		dcpu = &dstate->dtds_percpu[i];
1002 
1003 		if (dcpu->dtdsc_rinsing == NULL)
1004 			continue;
1005 
1006 		/*
1007 		 * We are now guaranteed that no hash chain contains a pointer
1008 		 * into this dirty list; we can make it clean.
1009 		 */
1010 		ASSERT(dcpu->dtdsc_clean == NULL);
1011 		dcpu->dtdsc_clean = dcpu->dtdsc_rinsing;
1012 		dcpu->dtdsc_rinsing = NULL;
1013 	}
1014 
1015 	/*
1016 	 * Before we actually set the state to be DTRACE_DSTATE_CLEAN, make
1017 	 * sure that all CPUs have seen all of the dtdsc_clean pointers.
1018 	 * This prevents a race whereby a CPU incorrectly decides that
1019 	 * the state should be something other than DTRACE_DSTATE_CLEAN
1020 	 * after dtrace_dynvar_clean() has completed.
1021 	 */
1022 	dtrace_sync();
1023 
1024 	dstate->dtds_state = DTRACE_DSTATE_CLEAN;
1025 }
1026 
1027 /*
1028  * Depending on the value of the op parameter, this function looks-up,
1029  * allocates or deallocates an arbitrarily-keyed dynamic variable.  If an
1030  * allocation is requested, this function will return a pointer to a
1031  * dtrace_dynvar_t corresponding to the allocated variable -- or NULL if no
1032  * variable can be allocated.  If NULL is returned, the appropriate counter
1033  * will be incremented.
1034  */
1035 dtrace_dynvar_t *
1036 dtrace_dynvar(dtrace_dstate_t *dstate, uint_t nkeys,
1037     dtrace_key_t *key, size_t dsize, dtrace_dynvar_op_t op)
1038 {
1039 	uint64_t hashval = DTRACE_DYNHASH_VALID;
1040 	dtrace_dynhash_t *hash = dstate->dtds_hash;
1041 	dtrace_dynvar_t *free, *new_free, *next, *dvar, *start, *prev = NULL;
1042 	processorid_t me = CPU->cpu_id, cpu = me;
1043 	dtrace_dstate_percpu_t *dcpu = &dstate->dtds_percpu[me];
1044 	size_t bucket, ksize;
1045 	size_t chunksize = dstate->dtds_chunksize;
1046 	uintptr_t kdata, lock, nstate;
1047 	uint_t i;
1048 
1049 	ASSERT(nkeys != 0);
1050 
1051 	/*
1052 	 * Hash the key.  As with aggregations, we use Jenkins' "One-at-a-time"
1053 	 * algorithm.  For the by-value portions, we perform the algorithm in
1054 	 * 16-bit chunks (as opposed to 8-bit chunks).  This speeds things up a
1055 	 * bit, and seems to have only a minute effect on distribution.  For
1056 	 * the by-reference data, we perform "One-at-a-time" iterating (safely)
1057 	 * over each referenced byte.  It's painful to do this, but it's much
1058 	 * better than pathological hash distribution.  The efficacy of the
1059 	 * hashing algorithm (and a comparison with other algorithms) may be
1060 	 * found by running the ::dtrace_dynstat MDB dcmd.
1061 	 */
1062 	for (i = 0; i < nkeys; i++) {
1063 		if (key[i].dttk_size == 0) {
1064 			uint64_t val = key[i].dttk_value;
1065 
1066 			hashval += (val >> 48) & 0xffff;
1067 			hashval += (hashval << 10);
1068 			hashval ^= (hashval >> 6);
1069 
1070 			hashval += (val >> 32) & 0xffff;
1071 			hashval += (hashval << 10);
1072 			hashval ^= (hashval >> 6);
1073 
1074 			hashval += (val >> 16) & 0xffff;
1075 			hashval += (hashval << 10);
1076 			hashval ^= (hashval >> 6);
1077 
1078 			hashval += val & 0xffff;
1079 			hashval += (hashval << 10);
1080 			hashval ^= (hashval >> 6);
1081 		} else {
1082 			/*
1083 			 * This is incredibly painful, but it beats the hell
1084 			 * out of the alternative.
1085 			 */
1086 			uint64_t j, size = key[i].dttk_size;
1087 			uintptr_t base = (uintptr_t)key[i].dttk_value;
1088 
1089 			for (j = 0; j < size; j++) {
1090 				hashval += dtrace_load8(base + j);
1091 				hashval += (hashval << 10);
1092 				hashval ^= (hashval >> 6);
1093 			}
1094 		}
1095 	}
1096 
1097 	hashval += (hashval << 3);
1098 	hashval ^= (hashval >> 11);
1099 	hashval += (hashval << 15);
1100 
1101 	/*
1102 	 * There is a remote chance (ideally, 1 in 2^31) that our hashval
1103 	 * comes out to be one of our two sentinel hash values.  If this
1104 	 * actually happens, we set the hashval to be a value known to be a
1105 	 * non-sentinel value.
1106 	 */
1107 	if (hashval == DTRACE_DYNHASH_FREE || hashval == DTRACE_DYNHASH_SINK)
1108 		hashval = DTRACE_DYNHASH_VALID;
1109 
1110 	/*
1111 	 * Yes, it's painful to do a divide here.  If the cycle count becomes
1112 	 * important here, tricks can be pulled to reduce it.  (However, it's
1113 	 * critical that hash collisions be kept to an absolute minimum;
1114 	 * they're much more painful than a divide.)  It's better to have a
1115 	 * solution that generates few collisions and still keeps things
1116 	 * relatively simple.
1117 	 */
1118 	bucket = hashval % dstate->dtds_hashsize;
1119 
1120 	if (op == DTRACE_DYNVAR_DEALLOC) {
1121 		volatile uintptr_t *lockp = &hash[bucket].dtdh_lock;
1122 
1123 		for (;;) {
1124 			while ((lock = *lockp) & 1)
1125 				continue;
1126 
1127 			if (dtrace_casptr((void *)lockp,
1128 			    (void *)lock, (void *)(lock + 1)) == (void *)lock)
1129 				break;
1130 		}
1131 
1132 		dtrace_membar_producer();
1133 	}
1134 
1135 top:
1136 	prev = NULL;
1137 	lock = hash[bucket].dtdh_lock;
1138 
1139 	dtrace_membar_consumer();
1140 
1141 	start = hash[bucket].dtdh_chain;
1142 	ASSERT(start != NULL && (start->dtdv_hashval == DTRACE_DYNHASH_SINK ||
1143 	    start->dtdv_hashval != DTRACE_DYNHASH_FREE ||
1144 	    op != DTRACE_DYNVAR_DEALLOC));
1145 
1146 	for (dvar = start; dvar != NULL; dvar = dvar->dtdv_next) {
1147 		dtrace_tuple_t *dtuple = &dvar->dtdv_tuple;
1148 		dtrace_key_t *dkey = &dtuple->dtt_key[0];
1149 
1150 		if (dvar->dtdv_hashval != hashval) {
1151 			if (dvar->dtdv_hashval == DTRACE_DYNHASH_SINK) {
1152 				/*
1153 				 * We've reached the sink, and therefore the
1154 				 * end of the hash chain; we can kick out of
1155 				 * the loop knowing that we have seen a valid
1156 				 * snapshot of state.
1157 				 */
1158 				ASSERT(dvar->dtdv_next == NULL);
1159 				ASSERT(dvar == &dtrace_dynhash_sink);
1160 				break;
1161 			}
1162 
1163 			if (dvar->dtdv_hashval == DTRACE_DYNHASH_FREE) {
1164 				/*
1165 				 * We've gone off the rails:  somewhere along
1166 				 * the line, one of the members of this hash
1167 				 * chain was deleted.  Note that we could also
1168 				 * detect this by simply letting this loop run
1169 				 * to completion, as we would eventually hit
1170 				 * the end of the dirty list.  However, we
1171 				 * want to avoid running the length of the
1172 				 * dirty list unnecessarily (it might be quite
1173 				 * long), so we catch this as early as
1174 				 * possible by detecting the hash marker.  In
1175 				 * this case, we simply set dvar to NULL and
1176 				 * break; the conditional after the loop will
1177 				 * send us back to top.
1178 				 */
1179 				dvar = NULL;
1180 				break;
1181 			}
1182 
1183 			goto next;
1184 		}
1185 
1186 		if (dtuple->dtt_nkeys != nkeys)
1187 			goto next;
1188 
1189 		for (i = 0; i < nkeys; i++, dkey++) {
1190 			if (dkey->dttk_size != key[i].dttk_size)
1191 				goto next; /* size or type mismatch */
1192 
1193 			if (dkey->dttk_size != 0) {
1194 				if (dtrace_bcmp(
1195 				    (void *)(uintptr_t)key[i].dttk_value,
1196 				    (void *)(uintptr_t)dkey->dttk_value,
1197 				    dkey->dttk_size))
1198 					goto next;
1199 			} else {
1200 				if (dkey->dttk_value != key[i].dttk_value)
1201 					goto next;
1202 			}
1203 		}
1204 
1205 		if (op != DTRACE_DYNVAR_DEALLOC)
1206 			return (dvar);
1207 
1208 		ASSERT(dvar->dtdv_next == NULL ||
1209 		    dvar->dtdv_next->dtdv_hashval != DTRACE_DYNHASH_FREE);
1210 
1211 		if (prev != NULL) {
1212 			ASSERT(hash[bucket].dtdh_chain != dvar);
1213 			ASSERT(start != dvar);
1214 			ASSERT(prev->dtdv_next == dvar);
1215 			prev->dtdv_next = dvar->dtdv_next;
1216 		} else {
1217 			if (dtrace_casptr(&hash[bucket].dtdh_chain,
1218 			    start, dvar->dtdv_next) != start) {
1219 				/*
1220 				 * We have failed to atomically swing the
1221 				 * hash table head pointer, presumably because
1222 				 * of a conflicting allocation on another CPU.
1223 				 * We need to reread the hash chain and try
1224 				 * again.
1225 				 */
1226 				goto top;
1227 			}
1228 		}
1229 
1230 		dtrace_membar_producer();
1231 
1232 		/*
1233 		 * Now set the hash value to indicate that it's free.
1234 		 */
1235 		ASSERT(hash[bucket].dtdh_chain != dvar);
1236 		dvar->dtdv_hashval = DTRACE_DYNHASH_FREE;
1237 
1238 		dtrace_membar_producer();
1239 
1240 		/*
1241 		 * Set the next pointer to point at the dirty list, and
1242 		 * atomically swing the dirty pointer to the newly freed dvar.
1243 		 */
1244 		do {
1245 			next = dcpu->dtdsc_dirty;
1246 			dvar->dtdv_next = next;
1247 		} while (dtrace_casptr(&dcpu->dtdsc_dirty, next, dvar) != next);
1248 
1249 		/*
1250 		 * Finally, unlock this hash bucket.
1251 		 */
1252 		ASSERT(hash[bucket].dtdh_lock == lock);
1253 		ASSERT(lock & 1);
1254 		hash[bucket].dtdh_lock++;
1255 
1256 		return (NULL);
1257 next:
1258 		prev = dvar;
1259 		continue;
1260 	}
1261 
1262 	if (dvar == NULL) {
1263 		/*
1264 		 * If dvar is NULL, it is because we went off the rails:
1265 		 * one of the elements that we traversed in the hash chain
1266 		 * was deleted while we were traversing it.  In this case,
1267 		 * we assert that we aren't doing a dealloc (deallocs lock
1268 		 * the hash bucket to prevent themselves from racing with
1269 		 * one another), and retry the hash chain traversal.
1270 		 */
1271 		ASSERT(op != DTRACE_DYNVAR_DEALLOC);
1272 		goto top;
1273 	}
1274 
1275 	if (op != DTRACE_DYNVAR_ALLOC) {
1276 		/*
1277 		 * If we are not to allocate a new variable, we want to
1278 		 * return NULL now.  Before we return, check that the value
1279 		 * of the lock word hasn't changed.  If it has, we may have
1280 		 * seen an inconsistent snapshot.
1281 		 */
1282 		if (op == DTRACE_DYNVAR_NOALLOC) {
1283 			if (hash[bucket].dtdh_lock != lock)
1284 				goto top;
1285 		} else {
1286 			ASSERT(op == DTRACE_DYNVAR_DEALLOC);
1287 			ASSERT(hash[bucket].dtdh_lock == lock);
1288 			ASSERT(lock & 1);
1289 			hash[bucket].dtdh_lock++;
1290 		}
1291 
1292 		return (NULL);
1293 	}
1294 
1295 	/*
1296 	 * We need to allocate a new dynamic variable.  The size we need is the
1297 	 * size of dtrace_dynvar plus the size of nkeys dtrace_key_t's plus the
1298 	 * size of any auxiliary key data (rounded up to 8-byte alignment) plus
1299 	 * the size of any referred-to data (dsize).  We then round the final
1300 	 * size up to the chunksize for allocation.
1301 	 */
1302 	for (ksize = 0, i = 0; i < nkeys; i++)
1303 		ksize += P2ROUNDUP(key[i].dttk_size, sizeof (uint64_t));
1304 
1305 	/*
1306 	 * This should be pretty much impossible, but could happen if, say,
1307 	 * strange DIF specified the tuple.  Ideally, this should be an
1308 	 * assertion and not an error condition -- but that requires that the
1309 	 * chunksize calculation in dtrace_difo_chunksize() be absolutely
1310 	 * bullet-proof.  (That is, it must not be able to be fooled by
1311 	 * malicious DIF.)  Given the lack of backwards branches in DIF,
1312 	 * solving this would presumably not amount to solving the Halting
1313 	 * Problem -- but it still seems awfully hard.
1314 	 */
1315 	if (sizeof (dtrace_dynvar_t) + sizeof (dtrace_key_t) * (nkeys - 1) +
1316 	    ksize + dsize > chunksize) {
1317 		dcpu->dtdsc_drops++;
1318 		return (NULL);
1319 	}
1320 
1321 	nstate = DTRACE_DSTATE_EMPTY;
1322 
1323 	do {
1324 retry:
1325 		free = dcpu->dtdsc_free;
1326 
1327 		if (free == NULL) {
1328 			dtrace_dynvar_t *clean = dcpu->dtdsc_clean;
1329 			void *rval;
1330 
1331 			if (clean == NULL) {
1332 				/*
1333 				 * We're out of dynamic variable space on
1334 				 * this CPU.  Unless we have tried all CPUs,
1335 				 * we'll try to allocate from a different
1336 				 * CPU.
1337 				 */
1338 				switch (dstate->dtds_state) {
1339 				case DTRACE_DSTATE_CLEAN: {
1340 					void *sp = &dstate->dtds_state;
1341 
1342 					if (++cpu >= NCPU)
1343 						cpu = 0;
1344 
1345 					if (dcpu->dtdsc_dirty != NULL &&
1346 					    nstate == DTRACE_DSTATE_EMPTY)
1347 						nstate = DTRACE_DSTATE_DIRTY;
1348 
1349 					if (dcpu->dtdsc_rinsing != NULL)
1350 						nstate = DTRACE_DSTATE_RINSING;
1351 
1352 					dcpu = &dstate->dtds_percpu[cpu];
1353 
1354 					if (cpu != me)
1355 						goto retry;
1356 
1357 					(void) dtrace_cas32(sp,
1358 					    DTRACE_DSTATE_CLEAN, nstate);
1359 
1360 					/*
1361 					 * To increment the correct bean
1362 					 * counter, take another lap.
1363 					 */
1364 					goto retry;
1365 				}
1366 
1367 				case DTRACE_DSTATE_DIRTY:
1368 					dcpu->dtdsc_dirty_drops++;
1369 					break;
1370 
1371 				case DTRACE_DSTATE_RINSING:
1372 					dcpu->dtdsc_rinsing_drops++;
1373 					break;
1374 
1375 				case DTRACE_DSTATE_EMPTY:
1376 					dcpu->dtdsc_drops++;
1377 					break;
1378 				}
1379 
1380 				DTRACE_CPUFLAG_SET(CPU_DTRACE_DROP);
1381 				return (NULL);
1382 			}
1383 
1384 			/*
1385 			 * The clean list appears to be non-empty.  We want to
1386 			 * move the clean list to the free list; we start by
1387 			 * moving the clean pointer aside.
1388 			 */
1389 			if (dtrace_casptr(&dcpu->dtdsc_clean,
1390 			    clean, NULL) != clean) {
1391 				/*
1392 				 * We are in one of two situations:
1393 				 *
1394 				 *  (a)	The clean list was switched to the
1395 				 *	free list by another CPU.
1396 				 *
1397 				 *  (b)	The clean list was added to by the
1398 				 *	cleansing cyclic.
1399 				 *
1400 				 * In either of these situations, we can
1401 				 * just reattempt the free list allocation.
1402 				 */
1403 				goto retry;
1404 			}
1405 
1406 			ASSERT(clean->dtdv_hashval == DTRACE_DYNHASH_FREE);
1407 
1408 			/*
1409 			 * Now we'll move the clean list to the free list.
1410 			 * It's impossible for this to fail:  the only way
1411 			 * the free list can be updated is through this
1412 			 * code path, and only one CPU can own the clean list.
1413 			 * Thus, it would only be possible for this to fail if
1414 			 * this code were racing with dtrace_dynvar_clean().
1415 			 * (That is, if dtrace_dynvar_clean() updated the clean
1416 			 * list, and we ended up racing to update the free
1417 			 * list.)  This race is prevented by the dtrace_sync()
1418 			 * in dtrace_dynvar_clean() -- which flushes the
1419 			 * owners of the clean lists out before resetting
1420 			 * the clean lists.
1421 			 */
1422 			rval = dtrace_casptr(&dcpu->dtdsc_free, NULL, clean);
1423 			ASSERT(rval == NULL);
1424 			goto retry;
1425 		}
1426 
1427 		dvar = free;
1428 		new_free = dvar->dtdv_next;
1429 	} while (dtrace_casptr(&dcpu->dtdsc_free, free, new_free) != free);
1430 
1431 	/*
1432 	 * We have now allocated a new chunk.  We copy the tuple keys into the
1433 	 * tuple array and copy any referenced key data into the data space
1434 	 * following the tuple array.  As we do this, we relocate dttk_value
1435 	 * in the final tuple to point to the key data address in the chunk.
1436 	 */
1437 	kdata = (uintptr_t)&dvar->dtdv_tuple.dtt_key[nkeys];
1438 	dvar->dtdv_data = (void *)(kdata + ksize);
1439 	dvar->dtdv_tuple.dtt_nkeys = nkeys;
1440 
1441 	for (i = 0; i < nkeys; i++) {
1442 		dtrace_key_t *dkey = &dvar->dtdv_tuple.dtt_key[i];
1443 		size_t kesize = key[i].dttk_size;
1444 
1445 		if (kesize != 0) {
1446 			dtrace_bcopy(
1447 			    (const void *)(uintptr_t)key[i].dttk_value,
1448 			    (void *)kdata, kesize);
1449 			dkey->dttk_value = kdata;
1450 			kdata += P2ROUNDUP(kesize, sizeof (uint64_t));
1451 		} else {
1452 			dkey->dttk_value = key[i].dttk_value;
1453 		}
1454 
1455 		dkey->dttk_size = kesize;
1456 	}
1457 
1458 	ASSERT(dvar->dtdv_hashval == DTRACE_DYNHASH_FREE);
1459 	dvar->dtdv_hashval = hashval;
1460 	dvar->dtdv_next = start;
1461 
1462 	if (dtrace_casptr(&hash[bucket].dtdh_chain, start, dvar) == start)
1463 		return (dvar);
1464 
1465 	/*
1466 	 * The cas has failed.  Either another CPU is adding an element to
1467 	 * this hash chain, or another CPU is deleting an element from this
1468 	 * hash chain.  The simplest way to deal with both of these cases
1469 	 * (though not necessarily the most efficient) is to free our
1470 	 * allocated block and tail-call ourselves.  Note that the free is
1471 	 * to the dirty list and _not_ to the free list.  This is to prevent
1472 	 * races with allocators, above.
1473 	 */
1474 	dvar->dtdv_hashval = DTRACE_DYNHASH_FREE;
1475 
1476 	dtrace_membar_producer();
1477 
1478 	do {
1479 		free = dcpu->dtdsc_dirty;
1480 		dvar->dtdv_next = free;
1481 	} while (dtrace_casptr(&dcpu->dtdsc_dirty, free, dvar) != free);
1482 
1483 	return (dtrace_dynvar(dstate, nkeys, key, dsize, op));
1484 }
1485 
1486 /*ARGSUSED*/
1487 static void
1488 dtrace_aggregate_min(uint64_t *oval, uint64_t nval, uint64_t arg)
1489 {
1490 	if (nval < *oval)
1491 		*oval = nval;
1492 }
1493 
1494 /*ARGSUSED*/
1495 static void
1496 dtrace_aggregate_max(uint64_t *oval, uint64_t nval, uint64_t arg)
1497 {
1498 	if (nval > *oval)
1499 		*oval = nval;
1500 }
1501 
1502 static void
1503 dtrace_aggregate_quantize(uint64_t *quanta, uint64_t nval, uint64_t incr)
1504 {
1505 	int i, zero = DTRACE_QUANTIZE_ZEROBUCKET;
1506 	int64_t val = (int64_t)nval;
1507 
1508 	if (val < 0) {
1509 		for (i = 0; i < zero; i++) {
1510 			if (val <= DTRACE_QUANTIZE_BUCKETVAL(i)) {
1511 				quanta[i] += incr;
1512 				return;
1513 			}
1514 		}
1515 	} else {
1516 		for (i = zero + 1; i < DTRACE_QUANTIZE_NBUCKETS; i++) {
1517 			if (val < DTRACE_QUANTIZE_BUCKETVAL(i)) {
1518 				quanta[i - 1] += incr;
1519 				return;
1520 			}
1521 		}
1522 
1523 		quanta[DTRACE_QUANTIZE_NBUCKETS - 1] += incr;
1524 		return;
1525 	}
1526 
1527 	ASSERT(0);
1528 }
1529 
1530 static void
1531 dtrace_aggregate_lquantize(uint64_t *lquanta, uint64_t nval, uint64_t incr)
1532 {
1533 	uint64_t arg = *lquanta++;
1534 	int32_t base = DTRACE_LQUANTIZE_BASE(arg);
1535 	uint16_t step = DTRACE_LQUANTIZE_STEP(arg);
1536 	uint16_t levels = DTRACE_LQUANTIZE_LEVELS(arg);
1537 	int32_t val = (int32_t)nval, level;
1538 
1539 	ASSERT(step != 0);
1540 	ASSERT(levels != 0);
1541 
1542 	if (val < base) {
1543 		/*
1544 		 * This is an underflow.
1545 		 */
1546 		lquanta[0] += incr;
1547 		return;
1548 	}
1549 
1550 	level = (val - base) / step;
1551 
1552 	if (level < levels) {
1553 		lquanta[level + 1] += incr;
1554 		return;
1555 	}
1556 
1557 	/*
1558 	 * This is an overflow.
1559 	 */
1560 	lquanta[levels + 1] += incr;
1561 }
1562 
1563 /*ARGSUSED*/
1564 static void
1565 dtrace_aggregate_avg(uint64_t *data, uint64_t nval, uint64_t arg)
1566 {
1567 	data[0]++;
1568 	data[1] += nval;
1569 }
1570 
1571 /*ARGSUSED*/
1572 static void
1573 dtrace_aggregate_count(uint64_t *oval, uint64_t nval, uint64_t arg)
1574 {
1575 	*oval = *oval + 1;
1576 }
1577 
1578 /*ARGSUSED*/
1579 static void
1580 dtrace_aggregate_sum(uint64_t *oval, uint64_t nval, uint64_t arg)
1581 {
1582 	*oval += nval;
1583 }
1584 
1585 /*
1586  * Aggregate given the tuple in the principal data buffer, and the aggregating
1587  * action denoted by the specified dtrace_aggregation_t.  The aggregation
1588  * buffer is specified as the buf parameter.  This routine does not return
1589  * failure; if there is no space in the aggregation buffer, the data will be
1590  * dropped, and a corresponding counter incremented.
1591  */
1592 static void
1593 dtrace_aggregate(dtrace_aggregation_t *agg, dtrace_buffer_t *dbuf,
1594     intptr_t offset, dtrace_buffer_t *buf, uint64_t expr, uint64_t arg)
1595 {
1596 	dtrace_recdesc_t *rec = &agg->dtag_action.dta_rec;
1597 	uint32_t i, ndx, size, fsize;
1598 	uint32_t align = sizeof (uint64_t) - 1;
1599 	dtrace_aggbuffer_t *agb;
1600 	dtrace_aggkey_t *key;
1601 	uint32_t hashval = 0, limit, isstr;
1602 	caddr_t tomax, data, kdata;
1603 	dtrace_actkind_t action;
1604 	dtrace_action_t *act;
1605 	uintptr_t offs;
1606 
1607 	if (buf == NULL)
1608 		return;
1609 
1610 	if (!agg->dtag_hasarg) {
1611 		/*
1612 		 * Currently, only quantize() and lquantize() take additional
1613 		 * arguments, and they have the same semantics:  an increment
1614 		 * value that defaults to 1 when not present.  If additional
1615 		 * aggregating actions take arguments, the setting of the
1616 		 * default argument value will presumably have to become more
1617 		 * sophisticated...
1618 		 */
1619 		arg = 1;
1620 	}
1621 
1622 	action = agg->dtag_action.dta_kind - DTRACEACT_AGGREGATION;
1623 	size = rec->dtrd_offset - agg->dtag_base;
1624 	fsize = size + rec->dtrd_size;
1625 
1626 	ASSERT(dbuf->dtb_tomax != NULL);
1627 	data = dbuf->dtb_tomax + offset + agg->dtag_base;
1628 
1629 	if ((tomax = buf->dtb_tomax) == NULL) {
1630 		dtrace_buffer_drop(buf);
1631 		return;
1632 	}
1633 
1634 	/*
1635 	 * The metastructure is always at the bottom of the buffer.
1636 	 */
1637 	agb = (dtrace_aggbuffer_t *)(tomax + buf->dtb_size -
1638 	    sizeof (dtrace_aggbuffer_t));
1639 
1640 	if (buf->dtb_offset == 0) {
1641 		/*
1642 		 * We just kludge up approximately 1/8th of the size to be
1643 		 * buckets.  If this guess ends up being routinely
1644 		 * off-the-mark, we may need to dynamically readjust this
1645 		 * based on past performance.
1646 		 */
1647 		uintptr_t hashsize = (buf->dtb_size >> 3) / sizeof (uintptr_t);
1648 
1649 		if ((uintptr_t)agb - hashsize * sizeof (dtrace_aggkey_t *) <
1650 		    (uintptr_t)tomax || hashsize == 0) {
1651 			/*
1652 			 * We've been given a ludicrously small buffer;
1653 			 * increment our drop count and leave.
1654 			 */
1655 			dtrace_buffer_drop(buf);
1656 			return;
1657 		}
1658 
1659 		/*
1660 		 * And now, a pathetic attempt to try to get a an odd (or
1661 		 * perchance, a prime) hash size for better hash distribution.
1662 		 */
1663 		if (hashsize > (DTRACE_AGGHASHSIZE_SLEW << 3))
1664 			hashsize -= DTRACE_AGGHASHSIZE_SLEW;
1665 
1666 		agb->dtagb_hashsize = hashsize;
1667 		agb->dtagb_hash = (dtrace_aggkey_t **)((uintptr_t)agb -
1668 		    agb->dtagb_hashsize * sizeof (dtrace_aggkey_t *));
1669 		agb->dtagb_free = (uintptr_t)agb->dtagb_hash;
1670 
1671 		for (i = 0; i < agb->dtagb_hashsize; i++)
1672 			agb->dtagb_hash[i] = NULL;
1673 	}
1674 
1675 	ASSERT(agg->dtag_first != NULL);
1676 	ASSERT(agg->dtag_first->dta_intuple);
1677 
1678 	/*
1679 	 * Calculate the hash value based on the key.  Note that we _don't_
1680 	 * include the aggid in the hashing (but we will store it as part of
1681 	 * the key).  The hashing algorithm is Bob Jenkins' "One-at-a-time"
1682 	 * algorithm: a simple, quick algorithm that has no known funnels, and
1683 	 * gets good distribution in practice.  The efficacy of the hashing
1684 	 * algorithm (and a comparison with other algorithms) may be found by
1685 	 * running the ::dtrace_aggstat MDB dcmd.
1686 	 */
1687 	for (act = agg->dtag_first; act->dta_intuple; act = act->dta_next) {
1688 		i = act->dta_rec.dtrd_offset - agg->dtag_base;
1689 		limit = i + act->dta_rec.dtrd_size;
1690 		ASSERT(limit <= size);
1691 		isstr = DTRACEACT_ISSTRING(act);
1692 
1693 		for (; i < limit; i++) {
1694 			hashval += data[i];
1695 			hashval += (hashval << 10);
1696 			hashval ^= (hashval >> 6);
1697 
1698 			if (isstr && data[i] == '\0')
1699 				break;
1700 		}
1701 	}
1702 
1703 	hashval += (hashval << 3);
1704 	hashval ^= (hashval >> 11);
1705 	hashval += (hashval << 15);
1706 
1707 	/*
1708 	 * Yes, the divide here is expensive -- but it's generally the least
1709 	 * of the performance issues given the amount of data that we iterate
1710 	 * over to compute hash values, compare data, etc.
1711 	 */
1712 	ndx = hashval % agb->dtagb_hashsize;
1713 
1714 	for (key = agb->dtagb_hash[ndx]; key != NULL; key = key->dtak_next) {
1715 		ASSERT((caddr_t)key >= tomax);
1716 		ASSERT((caddr_t)key < tomax + buf->dtb_size);
1717 
1718 		if (hashval != key->dtak_hashval || key->dtak_size != size)
1719 			continue;
1720 
1721 		kdata = key->dtak_data;
1722 		ASSERT(kdata >= tomax && kdata < tomax + buf->dtb_size);
1723 
1724 		for (act = agg->dtag_first; act->dta_intuple;
1725 		    act = act->dta_next) {
1726 			i = act->dta_rec.dtrd_offset - agg->dtag_base;
1727 			limit = i + act->dta_rec.dtrd_size;
1728 			ASSERT(limit <= size);
1729 			isstr = DTRACEACT_ISSTRING(act);
1730 
1731 			for (; i < limit; i++) {
1732 				if (kdata[i] != data[i])
1733 					goto next;
1734 
1735 				if (isstr && data[i] == '\0')
1736 					break;
1737 			}
1738 		}
1739 
1740 		if (action != key->dtak_action) {
1741 			/*
1742 			 * We are aggregating on the same value in the same
1743 			 * aggregation with two different aggregating actions.
1744 			 * (This should have been picked up in the compiler,
1745 			 * so we may be dealing with errant or devious DIF.)
1746 			 * This is an error condition; we indicate as much,
1747 			 * and return.
1748 			 */
1749 			DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
1750 			return;
1751 		}
1752 
1753 		/*
1754 		 * This is a hit:  we need to apply the aggregator to
1755 		 * the value at this key.
1756 		 */
1757 		agg->dtag_aggregate((uint64_t *)(kdata + size), expr, arg);
1758 		return;
1759 next:
1760 		continue;
1761 	}
1762 
1763 	/*
1764 	 * We didn't find it.  We need to allocate some zero-filled space,
1765 	 * link it into the hash table appropriately, and apply the aggregator
1766 	 * to the (zero-filled) value.
1767 	 */
1768 	offs = buf->dtb_offset;
1769 	while (offs & (align - 1))
1770 		offs += sizeof (uint32_t);
1771 
1772 	/*
1773 	 * If we don't have enough room to both allocate a new key _and_
1774 	 * its associated data, increment the drop count and return.
1775 	 */
1776 	if ((uintptr_t)tomax + offs + fsize >
1777 	    agb->dtagb_free - sizeof (dtrace_aggkey_t)) {
1778 		dtrace_buffer_drop(buf);
1779 		return;
1780 	}
1781 
1782 	/*CONSTCOND*/
1783 	ASSERT(!(sizeof (dtrace_aggkey_t) & (sizeof (uintptr_t) - 1)));
1784 	key = (dtrace_aggkey_t *)(agb->dtagb_free - sizeof (dtrace_aggkey_t));
1785 	agb->dtagb_free -= sizeof (dtrace_aggkey_t);
1786 
1787 	key->dtak_data = kdata = tomax + offs;
1788 	buf->dtb_offset = offs + fsize;
1789 
1790 	/*
1791 	 * Now copy the data across.
1792 	 */
1793 	*((dtrace_aggid_t *)kdata) = agg->dtag_id;
1794 
1795 	for (i = sizeof (dtrace_aggid_t); i < size; i++)
1796 		kdata[i] = data[i];
1797 
1798 	/*
1799 	 * Because strings are not zeroed out by default, we need to iterate
1800 	 * looking for actions that store strings, and we need to explicitly
1801 	 * pad these strings out with zeroes.
1802 	 */
1803 	for (act = agg->dtag_first; act->dta_intuple; act = act->dta_next) {
1804 		int nul;
1805 
1806 		if (!DTRACEACT_ISSTRING(act))
1807 			continue;
1808 
1809 		i = act->dta_rec.dtrd_offset - agg->dtag_base;
1810 		limit = i + act->dta_rec.dtrd_size;
1811 		ASSERT(limit <= size);
1812 
1813 		for (nul = 0; i < limit; i++) {
1814 			if (nul) {
1815 				kdata[i] = '\0';
1816 				continue;
1817 			}
1818 
1819 			if (data[i] != '\0')
1820 				continue;
1821 
1822 			nul = 1;
1823 		}
1824 	}
1825 
1826 	for (i = size; i < fsize; i++)
1827 		kdata[i] = 0;
1828 
1829 	key->dtak_hashval = hashval;
1830 	key->dtak_size = size;
1831 	key->dtak_action = action;
1832 	key->dtak_next = agb->dtagb_hash[ndx];
1833 	agb->dtagb_hash[ndx] = key;
1834 
1835 	/*
1836 	 * Finally, apply the aggregator.
1837 	 */
1838 	*((uint64_t *)(key->dtak_data + size)) = agg->dtag_initial;
1839 	agg->dtag_aggregate((uint64_t *)(key->dtak_data + size), expr, arg);
1840 }
1841 
1842 /*
1843  * Given consumer state, this routine finds a speculation in the INACTIVE
1844  * state and transitions it into the ACTIVE state.  If there is no speculation
1845  * in the INACTIVE state, 0 is returned.  In this case, no error counter is
1846  * incremented -- it is up to the caller to take appropriate action.
1847  */
1848 static int
1849 dtrace_speculation(dtrace_state_t *state)
1850 {
1851 	int i = 0;
1852 	dtrace_speculation_state_t current;
1853 	uint32_t *stat = &state->dts_speculations_unavail, count;
1854 
1855 	while (i < state->dts_nspeculations) {
1856 		dtrace_speculation_t *spec = &state->dts_speculations[i];
1857 
1858 		current = spec->dtsp_state;
1859 
1860 		if (current != DTRACESPEC_INACTIVE) {
1861 			if (current == DTRACESPEC_COMMITTINGMANY ||
1862 			    current == DTRACESPEC_COMMITTING ||
1863 			    current == DTRACESPEC_DISCARDING)
1864 				stat = &state->dts_speculations_busy;
1865 			i++;
1866 			continue;
1867 		}
1868 
1869 		if (dtrace_cas32((uint32_t *)&spec->dtsp_state,
1870 		    current, DTRACESPEC_ACTIVE) == current)
1871 			return (i + 1);
1872 	}
1873 
1874 	/*
1875 	 * We couldn't find a speculation.  If we found as much as a single
1876 	 * busy speculation buffer, we'll attribute this failure as "busy"
1877 	 * instead of "unavail".
1878 	 */
1879 	do {
1880 		count = *stat;
1881 	} while (dtrace_cas32(stat, count, count + 1) != count);
1882 
1883 	return (0);
1884 }
1885 
1886 /*
1887  * This routine commits an active speculation.  If the specified speculation
1888  * is not in a valid state to perform a commit(), this routine will silently do
1889  * nothing.  The state of the specified speculation is transitioned according
1890  * to the state transition diagram outlined in <sys/dtrace_impl.h>
1891  */
1892 static void
1893 dtrace_speculation_commit(dtrace_state_t *state, processorid_t cpu,
1894     dtrace_specid_t which)
1895 {
1896 	dtrace_speculation_t *spec;
1897 	dtrace_buffer_t *src, *dest;
1898 	uintptr_t daddr, saddr, dlimit;
1899 	dtrace_speculation_state_t current, new;
1900 	intptr_t offs;
1901 
1902 	if (which == 0)
1903 		return;
1904 
1905 	if (which > state->dts_nspeculations) {
1906 		cpu_core[cpu].cpuc_dtrace_flags |= CPU_DTRACE_ILLOP;
1907 		return;
1908 	}
1909 
1910 	spec = &state->dts_speculations[which - 1];
1911 	src = &spec->dtsp_buffer[cpu];
1912 	dest = &state->dts_buffer[cpu];
1913 
1914 	do {
1915 		current = spec->dtsp_state;
1916 
1917 		if (current == DTRACESPEC_COMMITTINGMANY)
1918 			break;
1919 
1920 		switch (current) {
1921 		case DTRACESPEC_INACTIVE:
1922 		case DTRACESPEC_DISCARDING:
1923 			return;
1924 
1925 		case DTRACESPEC_COMMITTING:
1926 			/*
1927 			 * This is only possible if we are (a) commit()'ing
1928 			 * without having done a prior speculate() on this CPU
1929 			 * and (b) racing with another commit() on a different
1930 			 * CPU.  There's nothing to do -- we just assert that
1931 			 * our offset is 0.
1932 			 */
1933 			ASSERT(src->dtb_offset == 0);
1934 			return;
1935 
1936 		case DTRACESPEC_ACTIVE:
1937 			new = DTRACESPEC_COMMITTING;
1938 			break;
1939 
1940 		case DTRACESPEC_ACTIVEONE:
1941 			/*
1942 			 * This speculation is active on one CPU.  If our
1943 			 * buffer offset is non-zero, we know that the one CPU
1944 			 * must be us.  Otherwise, we are committing on a
1945 			 * different CPU from the speculate(), and we must
1946 			 * rely on being asynchronously cleaned.
1947 			 */
1948 			if (src->dtb_offset != 0) {
1949 				new = DTRACESPEC_COMMITTING;
1950 				break;
1951 			}
1952 			/*FALLTHROUGH*/
1953 
1954 		case DTRACESPEC_ACTIVEMANY:
1955 			new = DTRACESPEC_COMMITTINGMANY;
1956 			break;
1957 
1958 		default:
1959 			ASSERT(0);
1960 		}
1961 	} while (dtrace_cas32((uint32_t *)&spec->dtsp_state,
1962 	    current, new) != current);
1963 
1964 	/*
1965 	 * We have set the state to indicate that we are committing this
1966 	 * speculation.  Now reserve the necessary space in the destination
1967 	 * buffer.
1968 	 */
1969 	if ((offs = dtrace_buffer_reserve(dest, src->dtb_offset,
1970 	    sizeof (uint64_t), state, NULL)) < 0) {
1971 		dtrace_buffer_drop(dest);
1972 		goto out;
1973 	}
1974 
1975 	/*
1976 	 * We have the space; copy the buffer across.  (Note that this is a
1977 	 * highly subobtimal bcopy(); in the unlikely event that this becomes
1978 	 * a serious performance issue, a high-performance DTrace-specific
1979 	 * bcopy() should obviously be invented.)
1980 	 */
1981 	daddr = (uintptr_t)dest->dtb_tomax + offs;
1982 	dlimit = daddr + src->dtb_offset;
1983 	saddr = (uintptr_t)src->dtb_tomax;
1984 
1985 	/*
1986 	 * First, the aligned portion.
1987 	 */
1988 	while (dlimit - daddr >= sizeof (uint64_t)) {
1989 		*((uint64_t *)daddr) = *((uint64_t *)saddr);
1990 
1991 		daddr += sizeof (uint64_t);
1992 		saddr += sizeof (uint64_t);
1993 	}
1994 
1995 	/*
1996 	 * Now any left-over bit...
1997 	 */
1998 	while (dlimit - daddr)
1999 		*((uint8_t *)daddr++) = *((uint8_t *)saddr++);
2000 
2001 	/*
2002 	 * Finally, commit the reserved space in the destination buffer.
2003 	 */
2004 	dest->dtb_offset = offs + src->dtb_offset;
2005 
2006 out:
2007 	/*
2008 	 * If we're lucky enough to be the only active CPU on this speculation
2009 	 * buffer, we can just set the state back to DTRACESPEC_INACTIVE.
2010 	 */
2011 	if (current == DTRACESPEC_ACTIVE ||
2012 	    (current == DTRACESPEC_ACTIVEONE && new == DTRACESPEC_COMMITTING)) {
2013 		uint32_t rval = dtrace_cas32((uint32_t *)&spec->dtsp_state,
2014 		    DTRACESPEC_COMMITTING, DTRACESPEC_INACTIVE);
2015 
2016 		ASSERT(rval == DTRACESPEC_COMMITTING);
2017 	}
2018 
2019 	src->dtb_offset = 0;
2020 	src->dtb_xamot_drops += src->dtb_drops;
2021 	src->dtb_drops = 0;
2022 }
2023 
2024 /*
2025  * This routine discards an active speculation.  If the specified speculation
2026  * is not in a valid state to perform a discard(), this routine will silently
2027  * do nothing.  The state of the specified speculation is transitioned
2028  * according to the state transition diagram outlined in <sys/dtrace_impl.h>
2029  */
2030 static void
2031 dtrace_speculation_discard(dtrace_state_t *state, processorid_t cpu,
2032     dtrace_specid_t which)
2033 {
2034 	dtrace_speculation_t *spec;
2035 	dtrace_speculation_state_t current, new;
2036 	dtrace_buffer_t *buf;
2037 
2038 	if (which == 0)
2039 		return;
2040 
2041 	if (which > state->dts_nspeculations) {
2042 		cpu_core[cpu].cpuc_dtrace_flags |= CPU_DTRACE_ILLOP;
2043 		return;
2044 	}
2045 
2046 	spec = &state->dts_speculations[which - 1];
2047 	buf = &spec->dtsp_buffer[cpu];
2048 
2049 	do {
2050 		current = spec->dtsp_state;
2051 
2052 		switch (current) {
2053 		case DTRACESPEC_INACTIVE:
2054 		case DTRACESPEC_COMMITTINGMANY:
2055 		case DTRACESPEC_COMMITTING:
2056 		case DTRACESPEC_DISCARDING:
2057 			return;
2058 
2059 		case DTRACESPEC_ACTIVE:
2060 		case DTRACESPEC_ACTIVEMANY:
2061 			new = DTRACESPEC_DISCARDING;
2062 			break;
2063 
2064 		case DTRACESPEC_ACTIVEONE:
2065 			if (buf->dtb_offset != 0) {
2066 				new = DTRACESPEC_INACTIVE;
2067 			} else {
2068 				new = DTRACESPEC_DISCARDING;
2069 			}
2070 			break;
2071 
2072 		default:
2073 			ASSERT(0);
2074 		}
2075 	} while (dtrace_cas32((uint32_t *)&spec->dtsp_state,
2076 	    current, new) != current);
2077 
2078 	buf->dtb_offset = 0;
2079 	buf->dtb_drops = 0;
2080 }
2081 
2082 /*
2083  * Note:  not called from probe context.  This function is called
2084  * asynchronously from cross call context to clean any speculations that are
2085  * in the COMMITTINGMANY or DISCARDING states.  These speculations may not be
2086  * transitioned back to the INACTIVE state until all CPUs have cleaned the
2087  * speculation.
2088  */
2089 static void
2090 dtrace_speculation_clean_here(dtrace_state_t *state)
2091 {
2092 	dtrace_icookie_t cookie;
2093 	processorid_t cpu = CPU->cpu_id;
2094 	dtrace_buffer_t *dest = &state->dts_buffer[cpu];
2095 	dtrace_specid_t i;
2096 
2097 	cookie = dtrace_interrupt_disable();
2098 
2099 	if (dest->dtb_tomax == NULL) {
2100 		dtrace_interrupt_enable(cookie);
2101 		return;
2102 	}
2103 
2104 	for (i = 0; i < state->dts_nspeculations; i++) {
2105 		dtrace_speculation_t *spec = &state->dts_speculations[i];
2106 		dtrace_buffer_t *src = &spec->dtsp_buffer[cpu];
2107 
2108 		if (src->dtb_tomax == NULL)
2109 			continue;
2110 
2111 		if (spec->dtsp_state == DTRACESPEC_DISCARDING) {
2112 			src->dtb_offset = 0;
2113 			continue;
2114 		}
2115 
2116 		if (spec->dtsp_state != DTRACESPEC_COMMITTINGMANY)
2117 			continue;
2118 
2119 		if (src->dtb_offset == 0)
2120 			continue;
2121 
2122 		dtrace_speculation_commit(state, cpu, i + 1);
2123 	}
2124 
2125 	dtrace_interrupt_enable(cookie);
2126 }
2127 
2128 /*
2129  * Note:  not called from probe context.  This function is called
2130  * asynchronously (and at a regular interval) to clean any speculations that
2131  * are in the COMMITTINGMANY or DISCARDING states.  If it discovers that there
2132  * is work to be done, it cross calls all CPUs to perform that work;
2133  * COMMITMANY and DISCARDING speculations may not be transitioned back to the
2134  * INACTIVE state until they have been cleaned by all CPUs.
2135  */
2136 static void
2137 dtrace_speculation_clean(dtrace_state_t *state)
2138 {
2139 	int work = 0, rv;
2140 	dtrace_specid_t i;
2141 
2142 	for (i = 0; i < state->dts_nspeculations; i++) {
2143 		dtrace_speculation_t *spec = &state->dts_speculations[i];
2144 
2145 		ASSERT(!spec->dtsp_cleaning);
2146 
2147 		if (spec->dtsp_state != DTRACESPEC_DISCARDING &&
2148 		    spec->dtsp_state != DTRACESPEC_COMMITTINGMANY)
2149 			continue;
2150 
2151 		work++;
2152 		spec->dtsp_cleaning = 1;
2153 	}
2154 
2155 	if (!work)
2156 		return;
2157 
2158 	dtrace_xcall(DTRACE_CPUALL,
2159 	    (dtrace_xcall_t)dtrace_speculation_clean_here, state);
2160 
2161 	/*
2162 	 * We now know that all CPUs have committed or discarded their
2163 	 * speculation buffers, as appropriate.  We can now set the state
2164 	 * to inactive.
2165 	 */
2166 	for (i = 0; i < state->dts_nspeculations; i++) {
2167 		dtrace_speculation_t *spec = &state->dts_speculations[i];
2168 		dtrace_speculation_state_t current, new;
2169 
2170 		if (!spec->dtsp_cleaning)
2171 			continue;
2172 
2173 		current = spec->dtsp_state;
2174 		ASSERT(current == DTRACESPEC_DISCARDING ||
2175 		    current == DTRACESPEC_COMMITTINGMANY);
2176 
2177 		new = DTRACESPEC_INACTIVE;
2178 
2179 		rv = dtrace_cas32((uint32_t *)&spec->dtsp_state, current, new);
2180 		ASSERT(rv == current);
2181 		spec->dtsp_cleaning = 0;
2182 	}
2183 }
2184 
2185 /*
2186  * Called as part of a speculate() to get the speculative buffer associated
2187  * with a given speculation.  Returns NULL if the specified speculation is not
2188  * in an ACTIVE state.  If the speculation is in the ACTIVEONE state -- and
2189  * the active CPU is not the specified CPU -- the speculation will be
2190  * atomically transitioned into the ACTIVEMANY state.
2191  */
2192 static dtrace_buffer_t *
2193 dtrace_speculation_buffer(dtrace_state_t *state, processorid_t cpuid,
2194     dtrace_specid_t which)
2195 {
2196 	dtrace_speculation_t *spec;
2197 	dtrace_speculation_state_t current, new;
2198 	dtrace_buffer_t *buf;
2199 
2200 	if (which == 0)
2201 		return (NULL);
2202 
2203 	if (which > state->dts_nspeculations) {
2204 		cpu_core[cpuid].cpuc_dtrace_flags |= CPU_DTRACE_ILLOP;
2205 		return (NULL);
2206 	}
2207 
2208 	spec = &state->dts_speculations[which - 1];
2209 	buf = &spec->dtsp_buffer[cpuid];
2210 
2211 	do {
2212 		current = spec->dtsp_state;
2213 
2214 		switch (current) {
2215 		case DTRACESPEC_INACTIVE:
2216 		case DTRACESPEC_COMMITTINGMANY:
2217 		case DTRACESPEC_DISCARDING:
2218 			return (NULL);
2219 
2220 		case DTRACESPEC_COMMITTING:
2221 			ASSERT(buf->dtb_offset == 0);
2222 			return (NULL);
2223 
2224 		case DTRACESPEC_ACTIVEONE:
2225 			/*
2226 			 * This speculation is currently active on one CPU.
2227 			 * Check the offset in the buffer; if it's non-zero,
2228 			 * that CPU must be us (and we leave the state alone).
2229 			 * If it's zero, assume that we're starting on a new
2230 			 * CPU -- and change the state to indicate that the
2231 			 * speculation is active on more than one CPU.
2232 			 */
2233 			if (buf->dtb_offset != 0)
2234 				return (buf);
2235 
2236 			new = DTRACESPEC_ACTIVEMANY;
2237 			break;
2238 
2239 		case DTRACESPEC_ACTIVEMANY:
2240 			return (buf);
2241 
2242 		case DTRACESPEC_ACTIVE:
2243 			new = DTRACESPEC_ACTIVEONE;
2244 			break;
2245 
2246 		default:
2247 			ASSERT(0);
2248 		}
2249 	} while (dtrace_cas32((uint32_t *)&spec->dtsp_state,
2250 	    current, new) != current);
2251 
2252 	ASSERT(new == DTRACESPEC_ACTIVEONE || new == DTRACESPEC_ACTIVEMANY);
2253 	return (buf);
2254 }
2255 
2256 /*
2257  * This function implements the DIF emulator's variable lookups.  The emulator
2258  * passes a reserved variable identifier and optional built-in array index.
2259  */
2260 static uint64_t
2261 dtrace_dif_variable(dtrace_mstate_t *mstate, dtrace_state_t *state, uint64_t v,
2262     uint64_t ndx)
2263 {
2264 	/*
2265 	 * If we're accessing one of the uncached arguments, we'll turn this
2266 	 * into a reference in the args array.
2267 	 */
2268 	if (v >= DIF_VAR_ARG0 && v <= DIF_VAR_ARG9) {
2269 		ndx = v - DIF_VAR_ARG0;
2270 		v = DIF_VAR_ARGS;
2271 	}
2272 
2273 	switch (v) {
2274 	case DIF_VAR_ARGS:
2275 		ASSERT(mstate->dtms_present & DTRACE_MSTATE_ARGS);
2276 		if (ndx >= sizeof (mstate->dtms_arg) /
2277 		    sizeof (mstate->dtms_arg[0])) {
2278 			int aframes = mstate->dtms_probe->dtpr_aframes + 2;
2279 			dtrace_provider_t *pv;
2280 			uint64_t val;
2281 
2282 			pv = mstate->dtms_probe->dtpr_provider;
2283 			if (pv->dtpv_pops.dtps_getargval != NULL)
2284 				val = pv->dtpv_pops.dtps_getargval(pv->dtpv_arg,
2285 				    mstate->dtms_probe->dtpr_id,
2286 				    mstate->dtms_probe->dtpr_arg, ndx, aframes);
2287 			else
2288 				val = dtrace_getarg(ndx, aframes);
2289 
2290 			/*
2291 			 * This is regrettably required to keep the compiler
2292 			 * from tail-optimizing the call to dtrace_getarg().
2293 			 * The condition always evaluates to true, but the
2294 			 * compiler has no way of figuring that out a priori.
2295 			 * (None of this would be necessary if the compiler
2296 			 * could be relied upon to _always_ tail-optimize
2297 			 * the call to dtrace_getarg() -- but it can't.)
2298 			 */
2299 			if (mstate->dtms_probe != NULL)
2300 				return (val);
2301 
2302 			ASSERT(0);
2303 		}
2304 
2305 		return (mstate->dtms_arg[ndx]);
2306 
2307 	case DIF_VAR_UREGS: {
2308 		klwp_t *lwp;
2309 
2310 		if (!dtrace_priv_proc(state))
2311 			return (0);
2312 
2313 		if ((lwp = curthread->t_lwp) == NULL) {
2314 			DTRACE_CPUFLAG_SET(CPU_DTRACE_BADADDR);
2315 			cpu_core[CPU->cpu_id].cpuc_dtrace_illval = NULL;
2316 			return (0);
2317 		}
2318 
2319 		return (dtrace_getreg(lwp->lwp_regs, ndx));
2320 	}
2321 
2322 	case DIF_VAR_CURTHREAD:
2323 		if (!dtrace_priv_kernel(state))
2324 			return (0);
2325 		return ((uint64_t)(uintptr_t)curthread);
2326 
2327 	case DIF_VAR_TIMESTAMP:
2328 		if (!(mstate->dtms_present & DTRACE_MSTATE_TIMESTAMP)) {
2329 			mstate->dtms_timestamp = dtrace_gethrtime();
2330 			mstate->dtms_present |= DTRACE_MSTATE_TIMESTAMP;
2331 		}
2332 		return (mstate->dtms_timestamp);
2333 
2334 	case DIF_VAR_VTIMESTAMP:
2335 		ASSERT(dtrace_vtime_references != 0);
2336 		return (curthread->t_dtrace_vtime);
2337 
2338 	case DIF_VAR_WALLTIMESTAMP:
2339 		if (!(mstate->dtms_present & DTRACE_MSTATE_WALLTIMESTAMP)) {
2340 			mstate->dtms_walltimestamp = dtrace_gethrestime();
2341 			mstate->dtms_present |= DTRACE_MSTATE_WALLTIMESTAMP;
2342 		}
2343 		return (mstate->dtms_walltimestamp);
2344 
2345 	case DIF_VAR_IPL:
2346 		if (!dtrace_priv_kernel(state))
2347 			return (0);
2348 		if (!(mstate->dtms_present & DTRACE_MSTATE_IPL)) {
2349 			mstate->dtms_ipl = dtrace_getipl();
2350 			mstate->dtms_present |= DTRACE_MSTATE_IPL;
2351 		}
2352 		return (mstate->dtms_ipl);
2353 
2354 	case DIF_VAR_EPID:
2355 		ASSERT(mstate->dtms_present & DTRACE_MSTATE_EPID);
2356 		return (mstate->dtms_epid);
2357 
2358 	case DIF_VAR_ID:
2359 		ASSERT(mstate->dtms_present & DTRACE_MSTATE_PROBE);
2360 		return (mstate->dtms_probe->dtpr_id);
2361 
2362 	case DIF_VAR_STACKDEPTH:
2363 		if (!dtrace_priv_kernel(state))
2364 			return (0);
2365 		if (!(mstate->dtms_present & DTRACE_MSTATE_STACKDEPTH)) {
2366 			int aframes = mstate->dtms_probe->dtpr_aframes + 2;
2367 
2368 			mstate->dtms_stackdepth = dtrace_getstackdepth(aframes);
2369 			mstate->dtms_present |= DTRACE_MSTATE_STACKDEPTH;
2370 		}
2371 		return (mstate->dtms_stackdepth);
2372 
2373 	case DIF_VAR_USTACKDEPTH:
2374 		if (!dtrace_priv_proc(state))
2375 			return (0);
2376 		if (!(mstate->dtms_present & DTRACE_MSTATE_USTACKDEPTH)) {
2377 			/*
2378 			 * See comment in DIF_VAR_PID.
2379 			 */
2380 			if (DTRACE_ANCHORED(mstate->dtms_probe) &&
2381 			    CPU_ON_INTR(CPU)) {
2382 				mstate->dtms_ustackdepth = 0;
2383 			} else {
2384 				DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
2385 				mstate->dtms_ustackdepth =
2386 				    dtrace_getustackdepth();
2387 				DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
2388 			}
2389 			mstate->dtms_present |= DTRACE_MSTATE_USTACKDEPTH;
2390 		}
2391 		return (mstate->dtms_ustackdepth);
2392 
2393 	case DIF_VAR_CALLER:
2394 		if (!dtrace_priv_kernel(state))
2395 			return (0);
2396 		if (!(mstate->dtms_present & DTRACE_MSTATE_CALLER)) {
2397 			int aframes = mstate->dtms_probe->dtpr_aframes + 2;
2398 
2399 			if (!DTRACE_ANCHORED(mstate->dtms_probe)) {
2400 				/*
2401 				 * If this is an unanchored probe, we are
2402 				 * required to go through the slow path:
2403 				 * dtrace_caller() only guarantees correct
2404 				 * results for anchored probes.
2405 				 */
2406 				pc_t caller[2];
2407 
2408 				dtrace_getpcstack(caller, 2, aframes,
2409 				    (uint32_t *)(uintptr_t)mstate->dtms_arg[0]);
2410 				mstate->dtms_caller = caller[1];
2411 			} else if ((mstate->dtms_caller =
2412 			    dtrace_caller(aframes)) == -1) {
2413 				/*
2414 				 * We have failed to do this the quick way;
2415 				 * we must resort to the slower approach of
2416 				 * calling dtrace_getpcstack().
2417 				 */
2418 				pc_t caller;
2419 
2420 				dtrace_getpcstack(&caller, 1, aframes, NULL);
2421 				mstate->dtms_caller = caller;
2422 			}
2423 
2424 			mstate->dtms_present |= DTRACE_MSTATE_CALLER;
2425 		}
2426 		return (mstate->dtms_caller);
2427 
2428 	case DIF_VAR_UCALLER:
2429 		if (!dtrace_priv_proc(state))
2430 			return (0);
2431 
2432 		if (!(mstate->dtms_present & DTRACE_MSTATE_UCALLER)) {
2433 			uint64_t ustack[3];
2434 
2435 			/*
2436 			 * dtrace_getupcstack() fills in the first uint64_t
2437 			 * with the current PID.  The second uint64_t will
2438 			 * be the program counter at user-level.  The third
2439 			 * uint64_t will contain the caller, which is what
2440 			 * we're after.
2441 			 */
2442 			ustack[2] = NULL;
2443 			dtrace_getupcstack(ustack, 3);
2444 			mstate->dtms_ucaller = ustack[2];
2445 			mstate->dtms_present |= DTRACE_MSTATE_UCALLER;
2446 		}
2447 
2448 		return (mstate->dtms_ucaller);
2449 
2450 	case DIF_VAR_PROBEPROV:
2451 		ASSERT(mstate->dtms_present & DTRACE_MSTATE_PROBE);
2452 		return ((uint64_t)(uintptr_t)
2453 		    mstate->dtms_probe->dtpr_provider->dtpv_name);
2454 
2455 	case DIF_VAR_PROBEMOD:
2456 		ASSERT(mstate->dtms_present & DTRACE_MSTATE_PROBE);
2457 		return ((uint64_t)(uintptr_t)
2458 		    mstate->dtms_probe->dtpr_mod);
2459 
2460 	case DIF_VAR_PROBEFUNC:
2461 		ASSERT(mstate->dtms_present & DTRACE_MSTATE_PROBE);
2462 		return ((uint64_t)(uintptr_t)
2463 		    mstate->dtms_probe->dtpr_func);
2464 
2465 	case DIF_VAR_PROBENAME:
2466 		ASSERT(mstate->dtms_present & DTRACE_MSTATE_PROBE);
2467 		return ((uint64_t)(uintptr_t)
2468 		    mstate->dtms_probe->dtpr_name);
2469 
2470 	case DIF_VAR_PID:
2471 		if (!dtrace_priv_proc(state))
2472 			return (0);
2473 
2474 		/*
2475 		 * Note that we are assuming that an unanchored probe is
2476 		 * always due to a high-level interrupt.  (And we're assuming
2477 		 * that there is only a single high level interrupt.)
2478 		 */
2479 		if (DTRACE_ANCHORED(mstate->dtms_probe) && CPU_ON_INTR(CPU))
2480 			return (pid0.pid_id);
2481 
2482 		/*
2483 		 * It is always safe to dereference one's own t_procp pointer:
2484 		 * it always points to a valid, allocated proc structure.
2485 		 * Further, it is always safe to dereference the p_pidp member
2486 		 * of one's own proc structure.  (These are truisms becuase
2487 		 * threads and processes don't clean up their own state --
2488 		 * they leave that task to whomever reaps them.)
2489 		 */
2490 		return ((uint64_t)curthread->t_procp->p_pidp->pid_id);
2491 
2492 	case DIF_VAR_PPID:
2493 		if (!dtrace_priv_proc(state))
2494 			return (0);
2495 
2496 		/*
2497 		 * See comment in DIF_VAR_PID.
2498 		 */
2499 		if (DTRACE_ANCHORED(mstate->dtms_probe) && CPU_ON_INTR(CPU))
2500 			return (pid0.pid_id);
2501 
2502 		/*
2503 		 * It is always safe to dereference one's own t_procp pointer:
2504 		 * it always points to a valid, allocated proc structure.
2505 		 * (This is true because threads don't clean up their own
2506 		 * state -- they leave that task to whomever reaps them.)
2507 		 */
2508 		return ((uint64_t)curthread->t_procp->p_ppid);
2509 
2510 	case DIF_VAR_TID:
2511 		/*
2512 		 * See comment in DIF_VAR_PID.
2513 		 */
2514 		if (DTRACE_ANCHORED(mstate->dtms_probe) && CPU_ON_INTR(CPU))
2515 			return (0);
2516 
2517 		return ((uint64_t)curthread->t_tid);
2518 
2519 	case DIF_VAR_EXECNAME:
2520 		if (!dtrace_priv_proc(state))
2521 			return (0);
2522 
2523 		/*
2524 		 * See comment in DIF_VAR_PID.
2525 		 */
2526 		if (DTRACE_ANCHORED(mstate->dtms_probe) && CPU_ON_INTR(CPU))
2527 			return ((uint64_t)(uintptr_t)p0.p_user.u_comm);
2528 
2529 		/*
2530 		 * It is always safe to dereference one's own t_procp pointer:
2531 		 * it always points to a valid, allocated proc structure.
2532 		 * (This is true because threads don't clean up their own
2533 		 * state -- they leave that task to whomever reaps them.)
2534 		 */
2535 		return ((uint64_t)(uintptr_t)
2536 		    curthread->t_procp->p_user.u_comm);
2537 
2538 	case DIF_VAR_ZONENAME:
2539 		if (!dtrace_priv_proc(state))
2540 			return (0);
2541 
2542 		/*
2543 		 * See comment in DIF_VAR_PID.
2544 		 */
2545 		if (DTRACE_ANCHORED(mstate->dtms_probe) && CPU_ON_INTR(CPU))
2546 			return ((uint64_t)(uintptr_t)p0.p_zone->zone_name);
2547 
2548 		/*
2549 		 * It is always safe to dereference one's own t_procp pointer:
2550 		 * it always points to a valid, allocated proc structure.
2551 		 * (This is true because threads don't clean up their own
2552 		 * state -- they leave that task to whomever reaps them.)
2553 		 */
2554 		return ((uint64_t)(uintptr_t)
2555 		    curthread->t_procp->p_zone->zone_name);
2556 
2557 	case DIF_VAR_UID:
2558 		if (!dtrace_priv_proc(state))
2559 			return (0);
2560 
2561 		/*
2562 		 * See comment in DIF_VAR_PID.
2563 		 */
2564 		if (DTRACE_ANCHORED(mstate->dtms_probe) && CPU_ON_INTR(CPU))
2565 			return ((uint64_t)p0.p_cred->cr_uid);
2566 
2567 		/*
2568 		 * It is always safe to dereference one's own t_procp pointer:
2569 		 * it always points to a valid, allocated proc structure.
2570 		 * (This is true because threads don't clean up their own
2571 		 * state -- they leave that task to whomever reaps them.)
2572 		 *
2573 		 * Additionally, it is safe to dereference one's own process
2574 		 * credential, since this is never NULL after process birth.
2575 		 */
2576 		return ((uint64_t)curthread->t_procp->p_cred->cr_uid);
2577 
2578 	case DIF_VAR_GID:
2579 		if (!dtrace_priv_proc(state))
2580 			return (0);
2581 
2582 		/*
2583 		 * See comment in DIF_VAR_PID.
2584 		 */
2585 		if (DTRACE_ANCHORED(mstate->dtms_probe) && CPU_ON_INTR(CPU))
2586 			return ((uint64_t)p0.p_cred->cr_gid);
2587 
2588 		/*
2589 		 * It is always safe to dereference one's own t_procp pointer:
2590 		 * it always points to a valid, allocated proc structure.
2591 		 * (This is true because threads don't clean up their own
2592 		 * state -- they leave that task to whomever reaps them.)
2593 		 *
2594 		 * Additionally, it is safe to dereference one's own process
2595 		 * credential, since this is never NULL after process birth.
2596 		 */
2597 		return ((uint64_t)curthread->t_procp->p_cred->cr_gid);
2598 
2599 	case DIF_VAR_ERRNO: {
2600 		klwp_t *lwp;
2601 		if (!dtrace_priv_proc(state))
2602 			return (0);
2603 
2604 		/*
2605 		 * See comment in DIF_VAR_PID.
2606 		 */
2607 		if (DTRACE_ANCHORED(mstate->dtms_probe) && CPU_ON_INTR(CPU))
2608 			return (0);
2609 
2610 		/*
2611 		 * It is always safe to dereference one's own t_lwp pointer in
2612 		 * the event that this pointer is non-NULL.  (This is true
2613 		 * because threads and lwps don't clean up their own state --
2614 		 * they leave that task to whomever reaps them.)
2615 		 */
2616 		if ((lwp = curthread->t_lwp) == NULL)
2617 			return (0);
2618 
2619 		return ((uint64_t)lwp->lwp_errno);
2620 	}
2621 	default:
2622 		DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
2623 		return (0);
2624 	}
2625 }
2626 
2627 /*
2628  * Emulate the execution of DTrace ID subroutines invoked by the call opcode.
2629  * Notice that we don't bother validating the proper number of arguments or
2630  * their types in the tuple stack.  This isn't needed because all argument
2631  * interpretation is safe because of our load safety -- the worst that can
2632  * happen is that a bogus program can obtain bogus results.
2633  */
2634 static void
2635 dtrace_dif_subr(uint_t subr, uint_t rd, uint64_t *regs,
2636     dtrace_key_t *tupregs, int nargs,
2637     dtrace_mstate_t *mstate, dtrace_state_t *state)
2638 {
2639 	volatile uint16_t *flags = &cpu_core[CPU->cpu_id].cpuc_dtrace_flags;
2640 	volatile uintptr_t *illval = &cpu_core[CPU->cpu_id].cpuc_dtrace_illval;
2641 
2642 	union {
2643 		mutex_impl_t mi;
2644 		uint64_t mx;
2645 	} m;
2646 
2647 	union {
2648 		krwlock_t ri;
2649 		uintptr_t rw;
2650 	} r;
2651 
2652 	switch (subr) {
2653 	case DIF_SUBR_RAND:
2654 		regs[rd] = (dtrace_gethrtime() * 2416 + 374441) % 1771875;
2655 		break;
2656 
2657 	case DIF_SUBR_MUTEX_OWNED:
2658 		m.mx = dtrace_load64(tupregs[0].dttk_value);
2659 		if (MUTEX_TYPE_ADAPTIVE(&m.mi))
2660 			regs[rd] = MUTEX_OWNER(&m.mi) != MUTEX_NO_OWNER;
2661 		else
2662 			regs[rd] = LOCK_HELD(&m.mi.m_spin.m_spinlock);
2663 		break;
2664 
2665 	case DIF_SUBR_MUTEX_OWNER:
2666 		m.mx = dtrace_load64(tupregs[0].dttk_value);
2667 		if (MUTEX_TYPE_ADAPTIVE(&m.mi) &&
2668 		    MUTEX_OWNER(&m.mi) != MUTEX_NO_OWNER)
2669 			regs[rd] = (uintptr_t)MUTEX_OWNER(&m.mi);
2670 		else
2671 			regs[rd] = 0;
2672 		break;
2673 
2674 	case DIF_SUBR_MUTEX_TYPE_ADAPTIVE:
2675 		m.mx = dtrace_load64(tupregs[0].dttk_value);
2676 		regs[rd] = MUTEX_TYPE_ADAPTIVE(&m.mi);
2677 		break;
2678 
2679 	case DIF_SUBR_MUTEX_TYPE_SPIN:
2680 		m.mx = dtrace_load64(tupregs[0].dttk_value);
2681 		regs[rd] = MUTEX_TYPE_SPIN(&m.mi);
2682 		break;
2683 
2684 	case DIF_SUBR_RW_READ_HELD: {
2685 		uintptr_t tmp;
2686 
2687 		r.rw = dtrace_loadptr(tupregs[0].dttk_value);
2688 		regs[rd] = _RW_READ_HELD(&r.ri, tmp);
2689 		break;
2690 	}
2691 
2692 	case DIF_SUBR_RW_WRITE_HELD:
2693 		r.rw = dtrace_loadptr(tupregs[0].dttk_value);
2694 		regs[rd] = _RW_WRITE_HELD(&r.ri);
2695 		break;
2696 
2697 	case DIF_SUBR_RW_ISWRITER:
2698 		r.rw = dtrace_loadptr(tupregs[0].dttk_value);
2699 		regs[rd] = _RW_ISWRITER(&r.ri);
2700 		break;
2701 
2702 	case DIF_SUBR_BCOPY: {
2703 		/*
2704 		 * We need to be sure that the destination is in the scratch
2705 		 * region -- no other region is allowed.
2706 		 */
2707 		uintptr_t src = tupregs[0].dttk_value;
2708 		uintptr_t dest = tupregs[1].dttk_value;
2709 		size_t size = tupregs[2].dttk_value;
2710 
2711 		if (!dtrace_inscratch(dest, size, mstate)) {
2712 			*flags |= CPU_DTRACE_BADADDR;
2713 			*illval = regs[rd];
2714 			break;
2715 		}
2716 
2717 		dtrace_bcopy((void *)src, (void *)dest, size);
2718 		break;
2719 	}
2720 
2721 	case DIF_SUBR_ALLOCA:
2722 	case DIF_SUBR_COPYIN: {
2723 		uintptr_t dest = P2ROUNDUP(mstate->dtms_scratch_ptr, 8);
2724 		uint64_t size =
2725 		    tupregs[subr == DIF_SUBR_ALLOCA ? 0 : 1].dttk_value;
2726 		size_t scratch_size = (dest - mstate->dtms_scratch_ptr) + size;
2727 
2728 		/*
2729 		 * This action doesn't require any credential checks since
2730 		 * probes will not activate in user contexts to which the
2731 		 * enabling user does not have permissions.
2732 		 */
2733 		if (mstate->dtms_scratch_ptr + scratch_size >
2734 		    mstate->dtms_scratch_base + mstate->dtms_scratch_size) {
2735 			DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
2736 			regs[rd] = NULL;
2737 			break;
2738 		}
2739 
2740 		if (subr == DIF_SUBR_COPYIN) {
2741 			DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
2742 			dtrace_copyin(tupregs[0].dttk_value, dest, size);
2743 			DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
2744 		}
2745 
2746 		mstate->dtms_scratch_ptr += scratch_size;
2747 		regs[rd] = dest;
2748 		break;
2749 	}
2750 
2751 	case DIF_SUBR_COPYINTO: {
2752 		uint64_t size = tupregs[1].dttk_value;
2753 		uintptr_t dest = tupregs[2].dttk_value;
2754 
2755 		/*
2756 		 * This action doesn't require any credential checks since
2757 		 * probes will not activate in user contexts to which the
2758 		 * enabling user does not have permissions.
2759 		 */
2760 		if (!dtrace_inscratch(dest, size, mstate)) {
2761 			*flags |= CPU_DTRACE_BADADDR;
2762 			*illval = regs[rd];
2763 			break;
2764 		}
2765 
2766 		DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
2767 		dtrace_copyin(tupregs[0].dttk_value, dest, size);
2768 		DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
2769 		break;
2770 	}
2771 
2772 	case DIF_SUBR_COPYINSTR: {
2773 		uintptr_t dest = mstate->dtms_scratch_ptr;
2774 		uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
2775 
2776 		if (nargs > 1 && tupregs[1].dttk_value < size)
2777 			size = tupregs[1].dttk_value + 1;
2778 
2779 		/*
2780 		 * This action doesn't require any credential checks since
2781 		 * probes will not activate in user contexts to which the
2782 		 * enabling user does not have permissions.
2783 		 */
2784 		if (mstate->dtms_scratch_ptr + size >
2785 		    mstate->dtms_scratch_base + mstate->dtms_scratch_size) {
2786 			DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
2787 			regs[rd] = NULL;
2788 			break;
2789 		}
2790 
2791 		DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
2792 		dtrace_copyinstr(tupregs[0].dttk_value, dest, size);
2793 		DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
2794 
2795 		((char *)dest)[size - 1] = '\0';
2796 		mstate->dtms_scratch_ptr += size;
2797 		regs[rd] = dest;
2798 		break;
2799 	}
2800 
2801 	case DIF_SUBR_MSGSIZE:
2802 	case DIF_SUBR_MSGDSIZE: {
2803 		uintptr_t baddr = tupregs[0].dttk_value, daddr;
2804 		uintptr_t wptr, rptr;
2805 		size_t count = 0;
2806 		int cont = 0;
2807 
2808 		while (baddr != NULL && !(*flags & CPU_DTRACE_FAULT)) {
2809 			wptr = dtrace_loadptr(baddr +
2810 			    offsetof(mblk_t, b_wptr));
2811 
2812 			rptr = dtrace_loadptr(baddr +
2813 			    offsetof(mblk_t, b_rptr));
2814 
2815 			if (wptr < rptr) {
2816 				*flags |= CPU_DTRACE_BADADDR;
2817 				*illval = tupregs[0].dttk_value;
2818 				break;
2819 			}
2820 
2821 			daddr = dtrace_loadptr(baddr +
2822 			    offsetof(mblk_t, b_datap));
2823 
2824 			baddr = dtrace_loadptr(baddr +
2825 			    offsetof(mblk_t, b_cont));
2826 
2827 			/*
2828 			 * We want to prevent against denial-of-service here,
2829 			 * so we're only going to search the list for
2830 			 * dtrace_msgdsize_max mblks.
2831 			 */
2832 			if (cont++ > dtrace_msgdsize_max) {
2833 				*flags |= CPU_DTRACE_ILLOP;
2834 				break;
2835 			}
2836 
2837 			if (subr == DIF_SUBR_MSGDSIZE) {
2838 				if (dtrace_load8(daddr +
2839 				    offsetof(dblk_t, db_type)) != M_DATA)
2840 					continue;
2841 			}
2842 
2843 			count += wptr - rptr;
2844 		}
2845 
2846 		if (!(*flags & CPU_DTRACE_FAULT))
2847 			regs[rd] = count;
2848 
2849 		break;
2850 	}
2851 
2852 	case DIF_SUBR_PROGENYOF: {
2853 		pid_t pid = tupregs[0].dttk_value;
2854 		proc_t *p;
2855 		int rval = 0;
2856 
2857 		DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
2858 
2859 		for (p = curthread->t_procp; p != NULL; p = p->p_parent) {
2860 			if (p->p_pidp->pid_id == pid) {
2861 				rval = 1;
2862 				break;
2863 			}
2864 		}
2865 
2866 		DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
2867 
2868 		regs[rd] = rval;
2869 		break;
2870 	}
2871 
2872 	case DIF_SUBR_SPECULATION:
2873 		regs[rd] = dtrace_speculation(state);
2874 		break;
2875 
2876 	case DIF_SUBR_COPYOUT: {
2877 		uintptr_t kaddr = tupregs[0].dttk_value;
2878 		uintptr_t uaddr = tupregs[1].dttk_value;
2879 		uint64_t size = tupregs[2].dttk_value;
2880 
2881 		if (!dtrace_destructive_disallow &&
2882 		    dtrace_priv_proc_control(state) &&
2883 		    !dtrace_istoxic(kaddr, size)) {
2884 			DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
2885 			dtrace_copyout(kaddr, uaddr, size);
2886 			DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
2887 		}
2888 		break;
2889 	}
2890 
2891 	case DIF_SUBR_COPYOUTSTR: {
2892 		uintptr_t kaddr = tupregs[0].dttk_value;
2893 		uintptr_t uaddr = tupregs[1].dttk_value;
2894 		uint64_t size = tupregs[2].dttk_value;
2895 
2896 		if (!dtrace_destructive_disallow &&
2897 		    dtrace_priv_proc_control(state) &&
2898 		    !dtrace_istoxic(kaddr, size)) {
2899 			DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
2900 			dtrace_copyoutstr(kaddr, uaddr, size);
2901 			DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
2902 		}
2903 		break;
2904 	}
2905 
2906 	case DIF_SUBR_STRLEN:
2907 		regs[rd] = dtrace_strlen((char *)(uintptr_t)
2908 		    tupregs[0].dttk_value,
2909 		    state->dts_options[DTRACEOPT_STRSIZE]);
2910 		break;
2911 
2912 	case DIF_SUBR_STRCHR:
2913 	case DIF_SUBR_STRRCHR: {
2914 		/*
2915 		 * We're going to iterate over the string looking for the
2916 		 * specified character.  We will iterate until we have reached
2917 		 * the string length or we have found the character.  If this
2918 		 * is DIF_SUBR_STRRCHR, we will look for the last occurrence
2919 		 * of the specified character instead of the first.
2920 		 */
2921 		uintptr_t addr = tupregs[0].dttk_value;
2922 		uintptr_t limit = addr + state->dts_options[DTRACEOPT_STRSIZE];
2923 		char c, target = (char)tupregs[1].dttk_value;
2924 
2925 		for (regs[rd] = NULL; addr < limit; addr++) {
2926 			if ((c = dtrace_load8(addr)) == target) {
2927 				regs[rd] = addr;
2928 
2929 				if (subr == DIF_SUBR_STRCHR)
2930 					break;
2931 			}
2932 
2933 			if (c == '\0')
2934 				break;
2935 		}
2936 
2937 		break;
2938 	}
2939 
2940 	case DIF_SUBR_STRSTR:
2941 	case DIF_SUBR_INDEX:
2942 	case DIF_SUBR_RINDEX: {
2943 		/*
2944 		 * We're going to iterate over the string looking for the
2945 		 * specified string.  We will iterate until we have reached
2946 		 * the string length or we have found the string.  (Yes, this
2947 		 * is done in the most naive way possible -- but considering
2948 		 * that the string we're searching for is likely to be
2949 		 * relatively short, the complexity of Rabin-Karp or similar
2950 		 * hardly seems merited.)
2951 		 */
2952 		char *addr = (char *)(uintptr_t)tupregs[0].dttk_value;
2953 		char *substr = (char *)(uintptr_t)tupregs[1].dttk_value;
2954 		uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
2955 		size_t len = dtrace_strlen(addr, size);
2956 		size_t sublen = dtrace_strlen(substr, size);
2957 		char *limit = addr + len, *orig = addr;
2958 		int notfound = subr == DIF_SUBR_STRSTR ? 0 : -1;
2959 		int inc = 1;
2960 
2961 		regs[rd] = notfound;
2962 
2963 		/*
2964 		 * strstr() and index()/rindex() have similar semantics if
2965 		 * both strings are the empty string: strstr() returns a
2966 		 * pointer to the (empty) string, and index() and rindex()
2967 		 * both return index 0 (regardless of any position argument).
2968 		 */
2969 		if (sublen == 0 && len == 0) {
2970 			if (subr == DIF_SUBR_STRSTR)
2971 				regs[rd] = (uintptr_t)addr;
2972 			else
2973 				regs[rd] = 0;
2974 			break;
2975 		}
2976 
2977 		if (subr != DIF_SUBR_STRSTR) {
2978 			if (subr == DIF_SUBR_RINDEX) {
2979 				limit = orig - 1;
2980 				addr += len;
2981 				inc = -1;
2982 			}
2983 
2984 			/*
2985 			 * Both index() and rindex() take an optional position
2986 			 * argument that denotes the starting position.
2987 			 */
2988 			if (nargs == 3) {
2989 				int64_t pos = (int64_t)tupregs[2].dttk_value;
2990 
2991 				/*
2992 				 * If the position argument to index() is
2993 				 * negative, Perl implicitly clamps it at
2994 				 * zero.  This semantic is a little surprising
2995 				 * given the special meaning of negative
2996 				 * positions to similar Perl functions like
2997 				 * substr(), but it appears to reflect a
2998 				 * notion that index() can start from a
2999 				 * negative index and increment its way up to
3000 				 * the string.  Given this notion, Perl's
3001 				 * rindex() is at least self-consistent in
3002 				 * that it implicitly clamps positions greater
3003 				 * than the string length to be the string
3004 				 * length.  Where Perl completely loses
3005 				 * coherence, however, is when the specified
3006 				 * substring is the empty string ("").  In
3007 				 * this case, even if the position is
3008 				 * negative, rindex() returns 0 -- and even if
3009 				 * the position is greater than the length,
3010 				 * index() returns the string length.  These
3011 				 * semantics violate the notion that index()
3012 				 * should never return a value less than the
3013 				 * specified position and that rindex() should
3014 				 * never return a value greater than the
3015 				 * specified position.  (One assumes that
3016 				 * these semantics are artifacts of Perl's
3017 				 * implementation and not the results of
3018 				 * deliberate design -- it beggars belief that
3019 				 * even Larry Wall could desire such oddness.)
3020 				 * While in the abstract one would wish for
3021 				 * consistent position semantics across
3022 				 * substr(), index() and rindex() -- or at the
3023 				 * very least self-consistent position
3024 				 * semantics for index() and rindex() -- we
3025 				 * instead opt to keep with the extant Perl
3026 				 * semantics, in all their broken glory.  (Do
3027 				 * we have more desire to maintain Perl's
3028 				 * semantics than Perl does?  Probably.)
3029 				 */
3030 				if (subr == DIF_SUBR_RINDEX) {
3031 					if (pos < 0) {
3032 						if (sublen == 0)
3033 							regs[rd] = 0;
3034 						break;
3035 					}
3036 
3037 					if (pos > len)
3038 						pos = len;
3039 				} else {
3040 					if (pos < 0)
3041 						pos = 0;
3042 
3043 					if (pos >= len) {
3044 						if (sublen == 0)
3045 							regs[rd] = len;
3046 						break;
3047 					}
3048 				}
3049 
3050 				addr = orig + pos;
3051 			}
3052 		}
3053 
3054 		for (regs[rd] = notfound; addr != limit; addr += inc) {
3055 			if (dtrace_strncmp(addr, substr, sublen) == 0) {
3056 				if (subr != DIF_SUBR_STRSTR) {
3057 					/*
3058 					 * As D index() and rindex() are
3059 					 * modeled on Perl (and not on awk),
3060 					 * we return a zero-based (and not a
3061 					 * one-based) index.  (For you Perl
3062 					 * weenies: no, we're not going to add
3063 					 * $[ -- and shouldn't you be at a con
3064 					 * or something?)
3065 					 */
3066 					regs[rd] = (uintptr_t)(addr - orig);
3067 					break;
3068 				}
3069 
3070 				ASSERT(subr == DIF_SUBR_STRSTR);
3071 				regs[rd] = (uintptr_t)addr;
3072 				break;
3073 			}
3074 		}
3075 
3076 		break;
3077 	}
3078 
3079 	case DIF_SUBR_STRTOK: {
3080 		uintptr_t addr = tupregs[0].dttk_value;
3081 		uintptr_t tokaddr = tupregs[1].dttk_value;
3082 		uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
3083 		uintptr_t limit, toklimit = tokaddr + size;
3084 		uint8_t c, tokmap[32];	 /* 256 / 8 */
3085 		char *dest = (char *)mstate->dtms_scratch_ptr;
3086 		int i;
3087 
3088 		if (mstate->dtms_scratch_ptr + size >
3089 		    mstate->dtms_scratch_base + mstate->dtms_scratch_size) {
3090 			DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
3091 			regs[rd] = NULL;
3092 			break;
3093 		}
3094 
3095 		if (addr == NULL) {
3096 			/*
3097 			 * If the address specified is NULL, we use our saved
3098 			 * strtok pointer from the mstate.  Note that this
3099 			 * means that the saved strtok pointer is _only_
3100 			 * valid within multiple enablings of the same probe --
3101 			 * it behaves like an implicit clause-local variable.
3102 			 */
3103 			addr = mstate->dtms_strtok;
3104 		}
3105 
3106 		/*
3107 		 * First, zero the token map, and then process the token
3108 		 * string -- setting a bit in the map for every character
3109 		 * found in the token string.
3110 		 */
3111 		for (i = 0; i < sizeof (tokmap); i++)
3112 			tokmap[i] = 0;
3113 
3114 		for (; tokaddr < toklimit; tokaddr++) {
3115 			if ((c = dtrace_load8(tokaddr)) == '\0')
3116 				break;
3117 
3118 			ASSERT((c >> 3) < sizeof (tokmap));
3119 			tokmap[c >> 3] |= (1 << (c & 0x7));
3120 		}
3121 
3122 		for (limit = addr + size; addr < limit; addr++) {
3123 			/*
3124 			 * We're looking for a character that is _not_ contained
3125 			 * in the token string.
3126 			 */
3127 			if ((c = dtrace_load8(addr)) == '\0')
3128 				break;
3129 
3130 			if (!(tokmap[c >> 3] & (1 << (c & 0x7))))
3131 				break;
3132 		}
3133 
3134 		if (c == '\0') {
3135 			/*
3136 			 * We reached the end of the string without finding
3137 			 * any character that was not in the token string.
3138 			 * We return NULL in this case, and we set the saved
3139 			 * address to NULL as well.
3140 			 */
3141 			regs[rd] = NULL;
3142 			mstate->dtms_strtok = NULL;
3143 			break;
3144 		}
3145 
3146 		/*
3147 		 * From here on, we're copying into the destination string.
3148 		 */
3149 		for (i = 0; addr < limit && i < size - 1; addr++) {
3150 			if ((c = dtrace_load8(addr)) == '\0')
3151 				break;
3152 
3153 			if (tokmap[c >> 3] & (1 << (c & 0x7)))
3154 				break;
3155 
3156 			ASSERT(i < size);
3157 			dest[i++] = c;
3158 		}
3159 
3160 		ASSERT(i < size);
3161 		dest[i] = '\0';
3162 		regs[rd] = (uintptr_t)dest;
3163 		mstate->dtms_scratch_ptr += size;
3164 		mstate->dtms_strtok = addr;
3165 		break;
3166 	}
3167 
3168 	case DIF_SUBR_SUBSTR: {
3169 		uintptr_t s = tupregs[0].dttk_value;
3170 		uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
3171 		char *d = (char *)mstate->dtms_scratch_ptr;
3172 		int64_t index = (int64_t)tupregs[1].dttk_value;
3173 		int64_t remaining = (int64_t)tupregs[2].dttk_value;
3174 		size_t len = dtrace_strlen((char *)s, size);
3175 		int64_t i = 0;
3176 
3177 		if (nargs <= 2)
3178 			remaining = (int64_t)size;
3179 
3180 		if (mstate->dtms_scratch_ptr + size >
3181 		    mstate->dtms_scratch_base + mstate->dtms_scratch_size) {
3182 			DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
3183 			regs[rd] = NULL;
3184 			break;
3185 		}
3186 
3187 		if (index < 0) {
3188 			index += len;
3189 
3190 			if (index < 0 && index + remaining > 0) {
3191 				remaining += index;
3192 				index = 0;
3193 			}
3194 		}
3195 
3196 		if (index >= len || index < 0)
3197 			index = len;
3198 
3199 		for (d[0] = '\0'; remaining > 0; remaining--) {
3200 			if ((d[i++] = dtrace_load8(s++ + index)) == '\0')
3201 				break;
3202 
3203 			if (i == size) {
3204 				d[i - 1] = '\0';
3205 				break;
3206 			}
3207 		}
3208 
3209 		mstate->dtms_scratch_ptr += size;
3210 		regs[rd] = (uintptr_t)d;
3211 		break;
3212 	}
3213 
3214 	case DIF_SUBR_GETMAJOR:
3215 #ifdef _LP64
3216 		regs[rd] = (tupregs[0].dttk_value >> NBITSMINOR64) & MAXMAJ64;
3217 #else
3218 		regs[rd] = (tupregs[0].dttk_value >> NBITSMINOR) & MAXMAJ;
3219 #endif
3220 		break;
3221 
3222 	case DIF_SUBR_GETMINOR:
3223 #ifdef _LP64
3224 		regs[rd] = tupregs[0].dttk_value & MAXMIN64;
3225 #else
3226 		regs[rd] = tupregs[0].dttk_value & MAXMIN;
3227 #endif
3228 		break;
3229 
3230 	case DIF_SUBR_DDI_PATHNAME: {
3231 		/*
3232 		 * This one is a galactic mess.  We are going to roughly
3233 		 * emulate ddi_pathname(), but it's made more complicated
3234 		 * by the fact that we (a) want to include the minor name and
3235 		 * (b) must proceed iteratively instead of recursively.
3236 		 */
3237 		uintptr_t dest = mstate->dtms_scratch_ptr;
3238 		uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
3239 		char *start = (char *)dest, *end = start + size - 1;
3240 		uintptr_t daddr = tupregs[0].dttk_value;
3241 		int64_t minor = (int64_t)tupregs[1].dttk_value;
3242 		char *s;
3243 		int i, len, depth = 0;
3244 
3245 		if (size == 0 || mstate->dtms_scratch_ptr + size >
3246 		    mstate->dtms_scratch_base + mstate->dtms_scratch_size) {
3247 			DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
3248 			regs[rd] = NULL;
3249 			break;
3250 		}
3251 
3252 		*end = '\0';
3253 
3254 		/*
3255 		 * We want to have a name for the minor.  In order to do this,
3256 		 * we need to walk the minor list from the devinfo.  We want
3257 		 * to be sure that we don't infinitely walk a circular list,
3258 		 * so we check for circularity by sending a scout pointer
3259 		 * ahead two elements for every element that we iterate over;
3260 		 * if the list is circular, these will ultimately point to the
3261 		 * same element.  You may recognize this little trick as the
3262 		 * answer to a stupid interview question -- one that always
3263 		 * seems to be asked by those who had to have it laboriously
3264 		 * explained to them, and who can't even concisely describe
3265 		 * the conditions under which one would be forced to resort to
3266 		 * this technique.  Needless to say, those conditions are
3267 		 * found here -- and probably only here.  Is this is the only
3268 		 * use of this infamous trick in shipping, production code?
3269 		 * If it isn't, it probably should be...
3270 		 */
3271 		if (minor != -1) {
3272 			uintptr_t maddr = dtrace_loadptr(daddr +
3273 			    offsetof(struct dev_info, devi_minor));
3274 
3275 			uintptr_t next = offsetof(struct ddi_minor_data, next);
3276 			uintptr_t name = offsetof(struct ddi_minor_data,
3277 			    d_minor) + offsetof(struct ddi_minor, name);
3278 			uintptr_t dev = offsetof(struct ddi_minor_data,
3279 			    d_minor) + offsetof(struct ddi_minor, dev);
3280 			uintptr_t scout;
3281 
3282 			if (maddr != NULL)
3283 				scout = dtrace_loadptr(maddr + next);
3284 
3285 			while (maddr != NULL && !(*flags & CPU_DTRACE_FAULT)) {
3286 				uint64_t m;
3287 #ifdef _LP64
3288 				m = dtrace_load64(maddr + dev) & MAXMIN64;
3289 #else
3290 				m = dtrace_load32(maddr + dev) & MAXMIN;
3291 #endif
3292 				if (m != minor) {
3293 					maddr = dtrace_loadptr(maddr + next);
3294 
3295 					if (scout == NULL)
3296 						continue;
3297 
3298 					scout = dtrace_loadptr(scout + next);
3299 
3300 					if (scout == NULL)
3301 						continue;
3302 
3303 					scout = dtrace_loadptr(scout + next);
3304 
3305 					if (scout == NULL)
3306 						continue;
3307 
3308 					if (scout == maddr) {
3309 						*flags |= CPU_DTRACE_ILLOP;
3310 						break;
3311 					}
3312 
3313 					continue;
3314 				}
3315 
3316 				/*
3317 				 * We have the minor data.  Now we need to
3318 				 * copy the minor's name into the end of the
3319 				 * pathname.
3320 				 */
3321 				s = (char *)dtrace_loadptr(maddr + name);
3322 				len = dtrace_strlen(s, size);
3323 
3324 				if (*flags & CPU_DTRACE_FAULT)
3325 					break;
3326 
3327 				if (len != 0) {
3328 					if ((end -= (len + 1)) < start)
3329 						break;
3330 
3331 					*end = ':';
3332 				}
3333 
3334 				for (i = 1; i <= len; i++)
3335 					end[i] = dtrace_load8((uintptr_t)s++);
3336 				break;
3337 			}
3338 		}
3339 
3340 		while (daddr != NULL && !(*flags & CPU_DTRACE_FAULT)) {
3341 			ddi_node_state_t devi_state;
3342 
3343 			devi_state = dtrace_load32(daddr +
3344 			    offsetof(struct dev_info, devi_node_state));
3345 
3346 			if (*flags & CPU_DTRACE_FAULT)
3347 				break;
3348 
3349 			if (devi_state >= DS_INITIALIZED) {
3350 				s = (char *)dtrace_loadptr(daddr +
3351 				    offsetof(struct dev_info, devi_addr));
3352 				len = dtrace_strlen(s, size);
3353 
3354 				if (*flags & CPU_DTRACE_FAULT)
3355 					break;
3356 
3357 				if (len != 0) {
3358 					if ((end -= (len + 1)) < start)
3359 						break;
3360 
3361 					*end = '@';
3362 				}
3363 
3364 				for (i = 1; i <= len; i++)
3365 					end[i] = dtrace_load8((uintptr_t)s++);
3366 			}
3367 
3368 			/*
3369 			 * Now for the node name...
3370 			 */
3371 			s = (char *)dtrace_loadptr(daddr +
3372 			    offsetof(struct dev_info, devi_node_name));
3373 
3374 			daddr = dtrace_loadptr(daddr +
3375 			    offsetof(struct dev_info, devi_parent));
3376 
3377 			/*
3378 			 * If our parent is NULL (that is, if we're the root
3379 			 * node), we're going to use the special path
3380 			 * "devices".
3381 			 */
3382 			if (daddr == NULL)
3383 				s = "devices";
3384 
3385 			len = dtrace_strlen(s, size);
3386 			if (*flags & CPU_DTRACE_FAULT)
3387 				break;
3388 
3389 			if ((end -= (len + 1)) < start)
3390 				break;
3391 
3392 			for (i = 1; i <= len; i++)
3393 				end[i] = dtrace_load8((uintptr_t)s++);
3394 			*end = '/';
3395 
3396 			if (depth++ > dtrace_devdepth_max) {
3397 				*flags |= CPU_DTRACE_ILLOP;
3398 				break;
3399 			}
3400 		}
3401 
3402 		if (end < start)
3403 			DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
3404 
3405 		if (daddr == NULL) {
3406 			regs[rd] = (uintptr_t)end;
3407 			mstate->dtms_scratch_ptr += size;
3408 		}
3409 
3410 		break;
3411 	}
3412 
3413 	case DIF_SUBR_STRJOIN: {
3414 		char *d = (char *)mstate->dtms_scratch_ptr;
3415 		uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
3416 		uintptr_t s1 = tupregs[0].dttk_value;
3417 		uintptr_t s2 = tupregs[1].dttk_value;
3418 		int i = 0;
3419 
3420 		if (mstate->dtms_scratch_ptr + size >
3421 		    mstate->dtms_scratch_base + mstate->dtms_scratch_size) {
3422 			DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
3423 			regs[rd] = NULL;
3424 			break;
3425 		}
3426 
3427 		for (;;) {
3428 			if (i >= size) {
3429 				DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
3430 				regs[rd] = NULL;
3431 				break;
3432 			}
3433 
3434 			if ((d[i++] = dtrace_load8(s1++)) == '\0') {
3435 				i--;
3436 				break;
3437 			}
3438 		}
3439 
3440 		for (;;) {
3441 			if (i >= size) {
3442 				DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
3443 				regs[rd] = NULL;
3444 				break;
3445 			}
3446 
3447 			if ((d[i++] = dtrace_load8(s2++)) == '\0')
3448 				break;
3449 		}
3450 
3451 		if (i < size) {
3452 			mstate->dtms_scratch_ptr += i;
3453 			regs[rd] = (uintptr_t)d;
3454 		}
3455 
3456 		break;
3457 	}
3458 
3459 	case DIF_SUBR_LLTOSTR: {
3460 		int64_t i = (int64_t)tupregs[0].dttk_value;
3461 		int64_t val = i < 0 ? i * -1 : i;
3462 		uint64_t size = 22;	/* enough room for 2^64 in decimal */
3463 		char *end = (char *)mstate->dtms_scratch_ptr + size - 1;
3464 
3465 		if (mstate->dtms_scratch_ptr + size >
3466 		    mstate->dtms_scratch_base + mstate->dtms_scratch_size) {
3467 			DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
3468 			regs[rd] = NULL;
3469 			break;
3470 		}
3471 
3472 		for (*end-- = '\0'; val; val /= 10)
3473 			*end-- = '0' + (val % 10);
3474 
3475 		if (i == 0)
3476 			*end-- = '0';
3477 
3478 		if (i < 0)
3479 			*end-- = '-';
3480 
3481 		regs[rd] = (uintptr_t)end + 1;
3482 		mstate->dtms_scratch_ptr += size;
3483 		break;
3484 	}
3485 
3486 	case DIF_SUBR_HTONS:
3487 	case DIF_SUBR_NTOHS:
3488 #ifdef _BIG_ENDIAN
3489 		regs[rd] = (uint16_t)tupregs[0].dttk_value;
3490 #else
3491 		regs[rd] = DT_BSWAP_16((uint16_t)tupregs[0].dttk_value);
3492 #endif
3493 		break;
3494 
3495 
3496 	case DIF_SUBR_HTONL:
3497 	case DIF_SUBR_NTOHL:
3498 #ifdef _BIG_ENDIAN
3499 		regs[rd] = (uint32_t)tupregs[0].dttk_value;
3500 #else
3501 		regs[rd] = DT_BSWAP_32((uint32_t)tupregs[0].dttk_value);
3502 #endif
3503 		break;
3504 
3505 
3506 	case DIF_SUBR_HTONLL:
3507 	case DIF_SUBR_NTOHLL:
3508 #ifdef _BIG_ENDIAN
3509 		regs[rd] = (uint64_t)tupregs[0].dttk_value;
3510 #else
3511 		regs[rd] = DT_BSWAP_64((uint64_t)tupregs[0].dttk_value);
3512 #endif
3513 		break;
3514 
3515 
3516 	case DIF_SUBR_DIRNAME:
3517 	case DIF_SUBR_BASENAME: {
3518 		char *dest = (char *)mstate->dtms_scratch_ptr;
3519 		uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
3520 		uintptr_t src = tupregs[0].dttk_value;
3521 		int i, j, len = dtrace_strlen((char *)src, size);
3522 		int lastbase = -1, firstbase = -1, lastdir = -1;
3523 		int start, end;
3524 
3525 		if (mstate->dtms_scratch_ptr + size >
3526 		    mstate->dtms_scratch_base + mstate->dtms_scratch_size) {
3527 			DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
3528 			regs[rd] = NULL;
3529 			break;
3530 		}
3531 
3532 		/*
3533 		 * The basename and dirname for a zero-length string is
3534 		 * defined to be "."
3535 		 */
3536 		if (len == 0) {
3537 			len = 1;
3538 			src = (uintptr_t)".";
3539 		}
3540 
3541 		/*
3542 		 * Start from the back of the string, moving back toward the
3543 		 * front until we see a character that isn't a slash.  That
3544 		 * character is the last character in the basename.
3545 		 */
3546 		for (i = len - 1; i >= 0; i--) {
3547 			if (dtrace_load8(src + i) != '/')
3548 				break;
3549 		}
3550 
3551 		if (i >= 0)
3552 			lastbase = i;
3553 
3554 		/*
3555 		 * Starting from the last character in the basename, move
3556 		 * towards the front until we find a slash.  The character
3557 		 * that we processed immediately before that is the first
3558 		 * character in the basename.
3559 		 */
3560 		for (; i >= 0; i--) {
3561 			if (dtrace_load8(src + i) == '/')
3562 				break;
3563 		}
3564 
3565 		if (i >= 0)
3566 			firstbase = i + 1;
3567 
3568 		/*
3569 		 * Now keep going until we find a non-slash character.  That
3570 		 * character is the last character in the dirname.
3571 		 */
3572 		for (; i >= 0; i--) {
3573 			if (dtrace_load8(src + i) != '/')
3574 				break;
3575 		}
3576 
3577 		if (i >= 0)
3578 			lastdir = i;
3579 
3580 		ASSERT(!(lastbase == -1 && firstbase != -1));
3581 		ASSERT(!(firstbase == -1 && lastdir != -1));
3582 
3583 		if (lastbase == -1) {
3584 			/*
3585 			 * We didn't find a non-slash character.  We know that
3586 			 * the length is non-zero, so the whole string must be
3587 			 * slashes.  In either the dirname or the basename
3588 			 * case, we return '/'.
3589 			 */
3590 			ASSERT(firstbase == -1);
3591 			firstbase = lastbase = lastdir = 0;
3592 		}
3593 
3594 		if (firstbase == -1) {
3595 			/*
3596 			 * The entire string consists only of a basename
3597 			 * component.  If we're looking for dirname, we need
3598 			 * to change our string to be just "."; if we're
3599 			 * looking for a basename, we'll just set the first
3600 			 * character of the basename to be 0.
3601 			 */
3602 			if (subr == DIF_SUBR_DIRNAME) {
3603 				ASSERT(lastdir == -1);
3604 				src = (uintptr_t)".";
3605 				lastdir = 0;
3606 			} else {
3607 				firstbase = 0;
3608 			}
3609 		}
3610 
3611 		if (subr == DIF_SUBR_DIRNAME) {
3612 			if (lastdir == -1) {
3613 				/*
3614 				 * We know that we have a slash in the name --
3615 				 * or lastdir would be set to 0, above.  And
3616 				 * because lastdir is -1, we know that this
3617 				 * slash must be the first character.  (That
3618 				 * is, the full string must be of the form
3619 				 * "/basename".)  In this case, the last
3620 				 * character of the directory name is 0.
3621 				 */
3622 				lastdir = 0;
3623 			}
3624 
3625 			start = 0;
3626 			end = lastdir;
3627 		} else {
3628 			ASSERT(subr == DIF_SUBR_BASENAME);
3629 			ASSERT(firstbase != -1 && lastbase != -1);
3630 			start = firstbase;
3631 			end = lastbase;
3632 		}
3633 
3634 		for (i = start, j = 0; i <= end && j < size - 1; i++, j++)
3635 			dest[j] = dtrace_load8(src + i);
3636 
3637 		dest[j] = '\0';
3638 		regs[rd] = (uintptr_t)dest;
3639 		mstate->dtms_scratch_ptr += size;
3640 		break;
3641 	}
3642 
3643 	case DIF_SUBR_CLEANPATH: {
3644 		char *dest = (char *)mstate->dtms_scratch_ptr, c;
3645 		uint64_t size = state->dts_options[DTRACEOPT_STRSIZE];
3646 		uintptr_t src = tupregs[0].dttk_value;
3647 		int i = 0, j = 0;
3648 
3649 		if (mstate->dtms_scratch_ptr + size >
3650 		    mstate->dtms_scratch_base + mstate->dtms_scratch_size) {
3651 			DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
3652 			regs[rd] = NULL;
3653 			break;
3654 		}
3655 
3656 		/*
3657 		 * Move forward, loading each character.
3658 		 */
3659 		do {
3660 			c = dtrace_load8(src + i++);
3661 next:
3662 			if (j + 5 >= size)	/* 5 = strlen("/..c\0") */
3663 				break;
3664 
3665 			if (c != '/') {
3666 				dest[j++] = c;
3667 				continue;
3668 			}
3669 
3670 			c = dtrace_load8(src + i++);
3671 
3672 			if (c == '/') {
3673 				/*
3674 				 * We have two slashes -- we can just advance
3675 				 * to the next character.
3676 				 */
3677 				goto next;
3678 			}
3679 
3680 			if (c != '.') {
3681 				/*
3682 				 * This is not "." and it's not ".." -- we can
3683 				 * just store the "/" and this character and
3684 				 * drive on.
3685 				 */
3686 				dest[j++] = '/';
3687 				dest[j++] = c;
3688 				continue;
3689 			}
3690 
3691 			c = dtrace_load8(src + i++);
3692 
3693 			if (c == '/') {
3694 				/*
3695 				 * This is a "/./" component.  We're not going
3696 				 * to store anything in the destination buffer;
3697 				 * we're just going to go to the next component.
3698 				 */
3699 				goto next;
3700 			}
3701 
3702 			if (c != '.') {
3703 				/*
3704 				 * This is not ".." -- we can just store the
3705 				 * "/." and this character and continue
3706 				 * processing.
3707 				 */
3708 				dest[j++] = '/';
3709 				dest[j++] = '.';
3710 				dest[j++] = c;
3711 				continue;
3712 			}
3713 
3714 			c = dtrace_load8(src + i++);
3715 
3716 			if (c != '/' && c != '\0') {
3717 				/*
3718 				 * This is not ".." -- it's "..[mumble]".
3719 				 * We'll store the "/.." and this character
3720 				 * and continue processing.
3721 				 */
3722 				dest[j++] = '/';
3723 				dest[j++] = '.';
3724 				dest[j++] = '.';
3725 				dest[j++] = c;
3726 				continue;
3727 			}
3728 
3729 			/*
3730 			 * This is "/../" or "/..\0".  We need to back up
3731 			 * our destination pointer until we find a "/".
3732 			 */
3733 			i--;
3734 			while (j != 0 && dest[--j] != '/')
3735 				continue;
3736 
3737 			if (c == '\0')
3738 				dest[++j] = '/';
3739 		} while (c != '\0');
3740 
3741 		dest[j] = '\0';
3742 		regs[rd] = (uintptr_t)dest;
3743 		mstate->dtms_scratch_ptr += size;
3744 		break;
3745 	}
3746 	}
3747 }
3748 
3749 /*
3750  * Emulate the execution of DTrace IR instructions specified by the given
3751  * DIF object.  This function is deliberately void of assertions as all of
3752  * the necessary checks are handled by a call to dtrace_difo_validate().
3753  */
3754 static uint64_t
3755 dtrace_dif_emulate(dtrace_difo_t *difo, dtrace_mstate_t *mstate,
3756     dtrace_vstate_t *vstate, dtrace_state_t *state)
3757 {
3758 	const dif_instr_t *text = difo->dtdo_buf;
3759 	const uint_t textlen = difo->dtdo_len;
3760 	const char *strtab = difo->dtdo_strtab;
3761 	const uint64_t *inttab = difo->dtdo_inttab;
3762 
3763 	uint64_t rval = 0;
3764 	dtrace_statvar_t *svar;
3765 	dtrace_dstate_t *dstate = &vstate->dtvs_dynvars;
3766 	dtrace_difv_t *v;
3767 	volatile uint16_t *flags = &cpu_core[CPU->cpu_id].cpuc_dtrace_flags;
3768 	volatile uintptr_t *illval = &cpu_core[CPU->cpu_id].cpuc_dtrace_illval;
3769 
3770 	dtrace_key_t tupregs[DIF_DTR_NREGS + 2]; /* +2 for thread and id */
3771 	uint64_t regs[DIF_DIR_NREGS];
3772 	uint64_t *tmp;
3773 
3774 	uint8_t cc_n = 0, cc_z = 0, cc_v = 0, cc_c = 0;
3775 	int64_t cc_r;
3776 	uint_t pc = 0, id, opc;
3777 	uint8_t ttop = 0;
3778 	dif_instr_t instr;
3779 	uint_t r1, r2, rd;
3780 
3781 	regs[DIF_REG_R0] = 0; 		/* %r0 is fixed at zero */
3782 
3783 	while (pc < textlen && !(*flags & CPU_DTRACE_FAULT)) {
3784 		opc = pc;
3785 
3786 		instr = text[pc++];
3787 		r1 = DIF_INSTR_R1(instr);
3788 		r2 = DIF_INSTR_R2(instr);
3789 		rd = DIF_INSTR_RD(instr);
3790 
3791 		switch (DIF_INSTR_OP(instr)) {
3792 		case DIF_OP_OR:
3793 			regs[rd] = regs[r1] | regs[r2];
3794 			break;
3795 		case DIF_OP_XOR:
3796 			regs[rd] = regs[r1] ^ regs[r2];
3797 			break;
3798 		case DIF_OP_AND:
3799 			regs[rd] = regs[r1] & regs[r2];
3800 			break;
3801 		case DIF_OP_SLL:
3802 			regs[rd] = regs[r1] << regs[r2];
3803 			break;
3804 		case DIF_OP_SRL:
3805 			regs[rd] = regs[r1] >> regs[r2];
3806 			break;
3807 		case DIF_OP_SUB:
3808 			regs[rd] = regs[r1] - regs[r2];
3809 			break;
3810 		case DIF_OP_ADD:
3811 			regs[rd] = regs[r1] + regs[r2];
3812 			break;
3813 		case DIF_OP_MUL:
3814 			regs[rd] = regs[r1] * regs[r2];
3815 			break;
3816 		case DIF_OP_SDIV:
3817 			if (regs[r2] == 0) {
3818 				regs[rd] = 0;
3819 				*flags |= CPU_DTRACE_DIVZERO;
3820 			} else {
3821 				regs[rd] = (int64_t)regs[r1] /
3822 				    (int64_t)regs[r2];
3823 			}
3824 			break;
3825 
3826 		case DIF_OP_UDIV:
3827 			if (regs[r2] == 0) {
3828 				regs[rd] = 0;
3829 				*flags |= CPU_DTRACE_DIVZERO;
3830 			} else {
3831 				regs[rd] = regs[r1] / regs[r2];
3832 			}
3833 			break;
3834 
3835 		case DIF_OP_SREM:
3836 			if (regs[r2] == 0) {
3837 				regs[rd] = 0;
3838 				*flags |= CPU_DTRACE_DIVZERO;
3839 			} else {
3840 				regs[rd] = (int64_t)regs[r1] %
3841 				    (int64_t)regs[r2];
3842 			}
3843 			break;
3844 
3845 		case DIF_OP_UREM:
3846 			if (regs[r2] == 0) {
3847 				regs[rd] = 0;
3848 				*flags |= CPU_DTRACE_DIVZERO;
3849 			} else {
3850 				regs[rd] = regs[r1] % regs[r2];
3851 			}
3852 			break;
3853 
3854 		case DIF_OP_NOT:
3855 			regs[rd] = ~regs[r1];
3856 			break;
3857 		case DIF_OP_MOV:
3858 			regs[rd] = regs[r1];
3859 			break;
3860 		case DIF_OP_CMP:
3861 			cc_r = regs[r1] - regs[r2];
3862 			cc_n = cc_r < 0;
3863 			cc_z = cc_r == 0;
3864 			cc_v = 0;
3865 			cc_c = regs[r1] < regs[r2];
3866 			break;
3867 		case DIF_OP_TST:
3868 			cc_n = cc_v = cc_c = 0;
3869 			cc_z = regs[r1] == 0;
3870 			break;
3871 		case DIF_OP_BA:
3872 			pc = DIF_INSTR_LABEL(instr);
3873 			break;
3874 		case DIF_OP_BE:
3875 			if (cc_z)
3876 				pc = DIF_INSTR_LABEL(instr);
3877 			break;
3878 		case DIF_OP_BNE:
3879 			if (cc_z == 0)
3880 				pc = DIF_INSTR_LABEL(instr);
3881 			break;
3882 		case DIF_OP_BG:
3883 			if ((cc_z | (cc_n ^ cc_v)) == 0)
3884 				pc = DIF_INSTR_LABEL(instr);
3885 			break;
3886 		case DIF_OP_BGU:
3887 			if ((cc_c | cc_z) == 0)
3888 				pc = DIF_INSTR_LABEL(instr);
3889 			break;
3890 		case DIF_OP_BGE:
3891 			if ((cc_n ^ cc_v) == 0)
3892 				pc = DIF_INSTR_LABEL(instr);
3893 			break;
3894 		case DIF_OP_BGEU:
3895 			if (cc_c == 0)
3896 				pc = DIF_INSTR_LABEL(instr);
3897 			break;
3898 		case DIF_OP_BL:
3899 			if (cc_n ^ cc_v)
3900 				pc = DIF_INSTR_LABEL(instr);
3901 			break;
3902 		case DIF_OP_BLU:
3903 			if (cc_c)
3904 				pc = DIF_INSTR_LABEL(instr);
3905 			break;
3906 		case DIF_OP_BLE:
3907 			if (cc_z | (cc_n ^ cc_v))
3908 				pc = DIF_INSTR_LABEL(instr);
3909 			break;
3910 		case DIF_OP_BLEU:
3911 			if (cc_c | cc_z)
3912 				pc = DIF_INSTR_LABEL(instr);
3913 			break;
3914 		case DIF_OP_RLDSB:
3915 			if (!dtrace_canstore(regs[r1], 1, mstate, vstate)) {
3916 				*flags |= CPU_DTRACE_KPRIV;
3917 				*illval = regs[r1];
3918 				break;
3919 			}
3920 			/*FALLTHROUGH*/
3921 		case DIF_OP_LDSB:
3922 			regs[rd] = (int8_t)dtrace_load8(regs[r1]);
3923 			break;
3924 		case DIF_OP_RLDSH:
3925 			if (!dtrace_canstore(regs[r1], 2, mstate, vstate)) {
3926 				*flags |= CPU_DTRACE_KPRIV;
3927 				*illval = regs[r1];
3928 				break;
3929 			}
3930 			/*FALLTHROUGH*/
3931 		case DIF_OP_LDSH:
3932 			regs[rd] = (int16_t)dtrace_load16(regs[r1]);
3933 			break;
3934 		case DIF_OP_RLDSW:
3935 			if (!dtrace_canstore(regs[r1], 4, mstate, vstate)) {
3936 				*flags |= CPU_DTRACE_KPRIV;
3937 				*illval = regs[r1];
3938 				break;
3939 			}
3940 			/*FALLTHROUGH*/
3941 		case DIF_OP_LDSW:
3942 			regs[rd] = (int32_t)dtrace_load32(regs[r1]);
3943 			break;
3944 		case DIF_OP_RLDUB:
3945 			if (!dtrace_canstore(regs[r1], 1, mstate, vstate)) {
3946 				*flags |= CPU_DTRACE_KPRIV;
3947 				*illval = regs[r1];
3948 				break;
3949 			}
3950 			/*FALLTHROUGH*/
3951 		case DIF_OP_LDUB:
3952 			regs[rd] = dtrace_load8(regs[r1]);
3953 			break;
3954 		case DIF_OP_RLDUH:
3955 			if (!dtrace_canstore(regs[r1], 2, mstate, vstate)) {
3956 				*flags |= CPU_DTRACE_KPRIV;
3957 				*illval = regs[r1];
3958 				break;
3959 			}
3960 			/*FALLTHROUGH*/
3961 		case DIF_OP_LDUH:
3962 			regs[rd] = dtrace_load16(regs[r1]);
3963 			break;
3964 		case DIF_OP_RLDUW:
3965 			if (!dtrace_canstore(regs[r1], 4, mstate, vstate)) {
3966 				*flags |= CPU_DTRACE_KPRIV;
3967 				*illval = regs[r1];
3968 				break;
3969 			}
3970 			/*FALLTHROUGH*/
3971 		case DIF_OP_LDUW:
3972 			regs[rd] = dtrace_load32(regs[r1]);
3973 			break;
3974 		case DIF_OP_RLDX:
3975 			if (!dtrace_canstore(regs[r1], 8, mstate, vstate)) {
3976 				*flags |= CPU_DTRACE_KPRIV;
3977 				*illval = regs[r1];
3978 				break;
3979 			}
3980 			/*FALLTHROUGH*/
3981 		case DIF_OP_LDX:
3982 			regs[rd] = dtrace_load64(regs[r1]);
3983 			break;
3984 		case DIF_OP_ULDSB:
3985 			regs[rd] = (int8_t)
3986 			    dtrace_fuword8((void *)(uintptr_t)regs[r1]);
3987 			break;
3988 		case DIF_OP_ULDSH:
3989 			regs[rd] = (int16_t)
3990 			    dtrace_fuword16((void *)(uintptr_t)regs[r1]);
3991 			break;
3992 		case DIF_OP_ULDSW:
3993 			regs[rd] = (int32_t)
3994 			    dtrace_fuword32((void *)(uintptr_t)regs[r1]);
3995 			break;
3996 		case DIF_OP_ULDUB:
3997 			regs[rd] =
3998 			    dtrace_fuword8((void *)(uintptr_t)regs[r1]);
3999 			break;
4000 		case DIF_OP_ULDUH:
4001 			regs[rd] =
4002 			    dtrace_fuword16((void *)(uintptr_t)regs[r1]);
4003 			break;
4004 		case DIF_OP_ULDUW:
4005 			regs[rd] =
4006 			    dtrace_fuword32((void *)(uintptr_t)regs[r1]);
4007 			break;
4008 		case DIF_OP_ULDX:
4009 			regs[rd] =
4010 			    dtrace_fuword64((void *)(uintptr_t)regs[r1]);
4011 			break;
4012 		case DIF_OP_RET:
4013 			rval = regs[rd];
4014 			break;
4015 		case DIF_OP_NOP:
4016 			break;
4017 		case DIF_OP_SETX:
4018 			regs[rd] = inttab[DIF_INSTR_INTEGER(instr)];
4019 			break;
4020 		case DIF_OP_SETS:
4021 			regs[rd] = (uint64_t)(uintptr_t)
4022 			    (strtab + DIF_INSTR_STRING(instr));
4023 			break;
4024 		case DIF_OP_SCMP:
4025 			cc_r = dtrace_strncmp((char *)(uintptr_t)regs[r1],
4026 			    (char *)(uintptr_t)regs[r2],
4027 			    state->dts_options[DTRACEOPT_STRSIZE]);
4028 
4029 			cc_n = cc_r < 0;
4030 			cc_z = cc_r == 0;
4031 			cc_v = cc_c = 0;
4032 			break;
4033 		case DIF_OP_LDGA:
4034 			regs[rd] = dtrace_dif_variable(mstate, state,
4035 			    r1, regs[r2]);
4036 			break;
4037 		case DIF_OP_LDGS:
4038 			id = DIF_INSTR_VAR(instr);
4039 
4040 			if (id >= DIF_VAR_OTHER_UBASE) {
4041 				uintptr_t a;
4042 
4043 				id -= DIF_VAR_OTHER_UBASE;
4044 				svar = vstate->dtvs_globals[id];
4045 				ASSERT(svar != NULL);
4046 				v = &svar->dtsv_var;
4047 
4048 				if (!(v->dtdv_type.dtdt_flags & DIF_TF_BYREF)) {
4049 					regs[rd] = svar->dtsv_data;
4050 					break;
4051 				}
4052 
4053 				a = (uintptr_t)svar->dtsv_data;
4054 
4055 				if (*(uint8_t *)a == UINT8_MAX) {
4056 					/*
4057 					 * If the 0th byte is set to UINT8_MAX
4058 					 * then this is to be treated as a
4059 					 * reference to a NULL variable.
4060 					 */
4061 					regs[rd] = NULL;
4062 				} else {
4063 					regs[rd] = a + sizeof (uint64_t);
4064 				}
4065 
4066 				break;
4067 			}
4068 
4069 			regs[rd] = dtrace_dif_variable(mstate, state, id, 0);
4070 			break;
4071 
4072 		case DIF_OP_STGS:
4073 			id = DIF_INSTR_VAR(instr);
4074 
4075 			ASSERT(id >= DIF_VAR_OTHER_UBASE);
4076 			id -= DIF_VAR_OTHER_UBASE;
4077 
4078 			svar = vstate->dtvs_globals[id];
4079 			ASSERT(svar != NULL);
4080 			v = &svar->dtsv_var;
4081 
4082 			if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF) {
4083 				uintptr_t a = (uintptr_t)svar->dtsv_data;
4084 
4085 				ASSERT(a != NULL);
4086 				ASSERT(svar->dtsv_size != 0);
4087 
4088 				if (regs[rd] == NULL) {
4089 					*(uint8_t *)a = UINT8_MAX;
4090 					break;
4091 				} else {
4092 					*(uint8_t *)a = 0;
4093 					a += sizeof (uint64_t);
4094 				}
4095 
4096 				dtrace_vcopy((void *)(uintptr_t)regs[rd],
4097 				    (void *)a, &v->dtdv_type);
4098 				break;
4099 			}
4100 
4101 			svar->dtsv_data = regs[rd];
4102 			break;
4103 
4104 		case DIF_OP_LDTA:
4105 			/*
4106 			 * There are no DTrace built-in thread-local arrays at
4107 			 * present.  This opcode is saved for future work.
4108 			 */
4109 			*flags |= CPU_DTRACE_ILLOP;
4110 			regs[rd] = 0;
4111 			break;
4112 
4113 		case DIF_OP_LDLS:
4114 			id = DIF_INSTR_VAR(instr);
4115 
4116 			if (id < DIF_VAR_OTHER_UBASE) {
4117 				/*
4118 				 * For now, this has no meaning.
4119 				 */
4120 				regs[rd] = 0;
4121 				break;
4122 			}
4123 
4124 			id -= DIF_VAR_OTHER_UBASE;
4125 
4126 			ASSERT(id < vstate->dtvs_nlocals);
4127 			ASSERT(vstate->dtvs_locals != NULL);
4128 
4129 			svar = vstate->dtvs_locals[id];
4130 			ASSERT(svar != NULL);
4131 			v = &svar->dtsv_var;
4132 
4133 			if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF) {
4134 				uintptr_t a = (uintptr_t)svar->dtsv_data;
4135 				size_t sz = v->dtdv_type.dtdt_size;
4136 
4137 				sz += sizeof (uint64_t);
4138 				ASSERT(svar->dtsv_size == NCPU * sz);
4139 				a += CPU->cpu_id * sz;
4140 
4141 				if (*(uint8_t *)a == UINT8_MAX) {
4142 					/*
4143 					 * If the 0th byte is set to UINT8_MAX
4144 					 * then this is to be treated as a
4145 					 * reference to a NULL variable.
4146 					 */
4147 					regs[rd] = NULL;
4148 				} else {
4149 					regs[rd] = a + sizeof (uint64_t);
4150 				}
4151 
4152 				break;
4153 			}
4154 
4155 			ASSERT(svar->dtsv_size == NCPU * sizeof (uint64_t));
4156 			tmp = (uint64_t *)(uintptr_t)svar->dtsv_data;
4157 			regs[rd] = tmp[CPU->cpu_id];
4158 			break;
4159 
4160 		case DIF_OP_STLS:
4161 			id = DIF_INSTR_VAR(instr);
4162 
4163 			ASSERT(id >= DIF_VAR_OTHER_UBASE);
4164 			id -= DIF_VAR_OTHER_UBASE;
4165 			ASSERT(id < vstate->dtvs_nlocals);
4166 
4167 			ASSERT(vstate->dtvs_locals != NULL);
4168 			svar = vstate->dtvs_locals[id];
4169 			ASSERT(svar != NULL);
4170 			v = &svar->dtsv_var;
4171 
4172 			if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF) {
4173 				uintptr_t a = (uintptr_t)svar->dtsv_data;
4174 				size_t sz = v->dtdv_type.dtdt_size;
4175 
4176 				sz += sizeof (uint64_t);
4177 				ASSERT(svar->dtsv_size == NCPU * sz);
4178 				a += CPU->cpu_id * sz;
4179 
4180 				if (regs[rd] == NULL) {
4181 					*(uint8_t *)a = UINT8_MAX;
4182 					break;
4183 				} else {
4184 					*(uint8_t *)a = 0;
4185 					a += sizeof (uint64_t);
4186 				}
4187 
4188 				dtrace_vcopy((void *)(uintptr_t)regs[rd],
4189 				    (void *)a, &v->dtdv_type);
4190 				break;
4191 			}
4192 
4193 			ASSERT(svar->dtsv_size == NCPU * sizeof (uint64_t));
4194 			tmp = (uint64_t *)(uintptr_t)svar->dtsv_data;
4195 			tmp[CPU->cpu_id] = regs[rd];
4196 			break;
4197 
4198 		case DIF_OP_LDTS: {
4199 			dtrace_dynvar_t *dvar;
4200 			dtrace_key_t *key;
4201 
4202 			id = DIF_INSTR_VAR(instr);
4203 			ASSERT(id >= DIF_VAR_OTHER_UBASE);
4204 			id -= DIF_VAR_OTHER_UBASE;
4205 			v = &vstate->dtvs_tlocals[id];
4206 
4207 			key = &tupregs[DIF_DTR_NREGS];
4208 			key[0].dttk_value = (uint64_t)id;
4209 			key[0].dttk_size = 0;
4210 			DTRACE_TLS_THRKEY(key[1].dttk_value);
4211 			key[1].dttk_size = 0;
4212 
4213 			dvar = dtrace_dynvar(dstate, 2, key,
4214 			    sizeof (uint64_t), DTRACE_DYNVAR_NOALLOC);
4215 
4216 			if (dvar == NULL) {
4217 				regs[rd] = 0;
4218 				break;
4219 			}
4220 
4221 			if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF) {
4222 				regs[rd] = (uint64_t)(uintptr_t)dvar->dtdv_data;
4223 			} else {
4224 				regs[rd] = *((uint64_t *)dvar->dtdv_data);
4225 			}
4226 
4227 			break;
4228 		}
4229 
4230 		case DIF_OP_STTS: {
4231 			dtrace_dynvar_t *dvar;
4232 			dtrace_key_t *key;
4233 
4234 			id = DIF_INSTR_VAR(instr);
4235 			ASSERT(id >= DIF_VAR_OTHER_UBASE);
4236 			id -= DIF_VAR_OTHER_UBASE;
4237 
4238 			key = &tupregs[DIF_DTR_NREGS];
4239 			key[0].dttk_value = (uint64_t)id;
4240 			key[0].dttk_size = 0;
4241 			DTRACE_TLS_THRKEY(key[1].dttk_value);
4242 			key[1].dttk_size = 0;
4243 			v = &vstate->dtvs_tlocals[id];
4244 
4245 			dvar = dtrace_dynvar(dstate, 2, key,
4246 			    v->dtdv_type.dtdt_size > sizeof (uint64_t) ?
4247 			    v->dtdv_type.dtdt_size : sizeof (uint64_t),
4248 			    regs[rd] ? DTRACE_DYNVAR_ALLOC :
4249 			    DTRACE_DYNVAR_DEALLOC);
4250 
4251 			/*
4252 			 * Given that we're storing to thread-local data,
4253 			 * we need to flush our predicate cache.
4254 			 */
4255 			curthread->t_predcache = NULL;
4256 
4257 			if (dvar == NULL)
4258 				break;
4259 
4260 			if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF) {
4261 				dtrace_vcopy((void *)(uintptr_t)regs[rd],
4262 				    dvar->dtdv_data, &v->dtdv_type);
4263 			} else {
4264 				*((uint64_t *)dvar->dtdv_data) = regs[rd];
4265 			}
4266 
4267 			break;
4268 		}
4269 
4270 		case DIF_OP_SRA:
4271 			regs[rd] = (int64_t)regs[r1] >> regs[r2];
4272 			break;
4273 
4274 		case DIF_OP_CALL:
4275 			dtrace_dif_subr(DIF_INSTR_SUBR(instr), rd,
4276 			    regs, tupregs, ttop, mstate, state);
4277 			break;
4278 
4279 		case DIF_OP_PUSHTR:
4280 			if (ttop == DIF_DTR_NREGS) {
4281 				*flags |= CPU_DTRACE_TUPOFLOW;
4282 				break;
4283 			}
4284 
4285 			if (r1 == DIF_TYPE_STRING) {
4286 				/*
4287 				 * If this is a string type and the size is 0,
4288 				 * we'll use the system-wide default string
4289 				 * size.  Note that we are _not_ looking at
4290 				 * the value of the DTRACEOPT_STRSIZE option;
4291 				 * had this been set, we would expect to have
4292 				 * a non-zero size value in the "pushtr".
4293 				 */
4294 				tupregs[ttop].dttk_size =
4295 				    dtrace_strlen((char *)(uintptr_t)regs[rd],
4296 				    regs[r2] ? regs[r2] :
4297 				    dtrace_strsize_default) + 1;
4298 			} else {
4299 				tupregs[ttop].dttk_size = regs[r2];
4300 			}
4301 
4302 			tupregs[ttop++].dttk_value = regs[rd];
4303 			break;
4304 
4305 		case DIF_OP_PUSHTV:
4306 			if (ttop == DIF_DTR_NREGS) {
4307 				*flags |= CPU_DTRACE_TUPOFLOW;
4308 				break;
4309 			}
4310 
4311 			tupregs[ttop].dttk_value = regs[rd];
4312 			tupregs[ttop++].dttk_size = 0;
4313 			break;
4314 
4315 		case DIF_OP_POPTS:
4316 			if (ttop != 0)
4317 				ttop--;
4318 			break;
4319 
4320 		case DIF_OP_FLUSHTS:
4321 			ttop = 0;
4322 			break;
4323 
4324 		case DIF_OP_LDGAA:
4325 		case DIF_OP_LDTAA: {
4326 			dtrace_dynvar_t *dvar;
4327 			dtrace_key_t *key = tupregs;
4328 			uint_t nkeys = ttop;
4329 
4330 			id = DIF_INSTR_VAR(instr);
4331 			ASSERT(id >= DIF_VAR_OTHER_UBASE);
4332 			id -= DIF_VAR_OTHER_UBASE;
4333 
4334 			key[nkeys].dttk_value = (uint64_t)id;
4335 			key[nkeys++].dttk_size = 0;
4336 
4337 			if (DIF_INSTR_OP(instr) == DIF_OP_LDTAA) {
4338 				DTRACE_TLS_THRKEY(key[nkeys].dttk_value);
4339 				key[nkeys++].dttk_size = 0;
4340 				v = &vstate->dtvs_tlocals[id];
4341 			} else {
4342 				v = &vstate->dtvs_globals[id]->dtsv_var;
4343 			}
4344 
4345 			dvar = dtrace_dynvar(dstate, nkeys, key,
4346 			    v->dtdv_type.dtdt_size > sizeof (uint64_t) ?
4347 			    v->dtdv_type.dtdt_size : sizeof (uint64_t),
4348 			    DTRACE_DYNVAR_NOALLOC);
4349 
4350 			if (dvar == NULL) {
4351 				regs[rd] = 0;
4352 				break;
4353 			}
4354 
4355 			if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF) {
4356 				regs[rd] = (uint64_t)(uintptr_t)dvar->dtdv_data;
4357 			} else {
4358 				regs[rd] = *((uint64_t *)dvar->dtdv_data);
4359 			}
4360 
4361 			break;
4362 		}
4363 
4364 		case DIF_OP_STGAA:
4365 		case DIF_OP_STTAA: {
4366 			dtrace_dynvar_t *dvar;
4367 			dtrace_key_t *key = tupregs;
4368 			uint_t nkeys = ttop;
4369 
4370 			id = DIF_INSTR_VAR(instr);
4371 			ASSERT(id >= DIF_VAR_OTHER_UBASE);
4372 			id -= DIF_VAR_OTHER_UBASE;
4373 
4374 			key[nkeys].dttk_value = (uint64_t)id;
4375 			key[nkeys++].dttk_size = 0;
4376 
4377 			if (DIF_INSTR_OP(instr) == DIF_OP_STTAA) {
4378 				DTRACE_TLS_THRKEY(key[nkeys].dttk_value);
4379 				key[nkeys++].dttk_size = 0;
4380 				v = &vstate->dtvs_tlocals[id];
4381 			} else {
4382 				v = &vstate->dtvs_globals[id]->dtsv_var;
4383 			}
4384 
4385 			dvar = dtrace_dynvar(dstate, nkeys, key,
4386 			    v->dtdv_type.dtdt_size > sizeof (uint64_t) ?
4387 			    v->dtdv_type.dtdt_size : sizeof (uint64_t),
4388 			    regs[rd] ? DTRACE_DYNVAR_ALLOC :
4389 			    DTRACE_DYNVAR_DEALLOC);
4390 
4391 			if (dvar == NULL)
4392 				break;
4393 
4394 			if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF) {
4395 				dtrace_vcopy((void *)(uintptr_t)regs[rd],
4396 				    dvar->dtdv_data, &v->dtdv_type);
4397 			} else {
4398 				*((uint64_t *)dvar->dtdv_data) = regs[rd];
4399 			}
4400 
4401 			break;
4402 		}
4403 
4404 		case DIF_OP_ALLOCS: {
4405 			uintptr_t ptr = P2ROUNDUP(mstate->dtms_scratch_ptr, 8);
4406 			size_t size = ptr - mstate->dtms_scratch_ptr + regs[r1];
4407 
4408 			if (mstate->dtms_scratch_ptr + size >
4409 			    mstate->dtms_scratch_base +
4410 			    mstate->dtms_scratch_size) {
4411 				DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
4412 				regs[rd] = NULL;
4413 			} else {
4414 				dtrace_bzero((void *)
4415 				    mstate->dtms_scratch_ptr, size);
4416 				mstate->dtms_scratch_ptr += size;
4417 				regs[rd] = ptr;
4418 			}
4419 			break;
4420 		}
4421 
4422 		case DIF_OP_COPYS:
4423 			if (!dtrace_canstore(regs[rd], regs[r2],
4424 			    mstate, vstate)) {
4425 				*flags |= CPU_DTRACE_BADADDR;
4426 				*illval = regs[rd];
4427 				break;
4428 			}
4429 
4430 			dtrace_bcopy((void *)(uintptr_t)regs[r1],
4431 			    (void *)(uintptr_t)regs[rd], (size_t)regs[r2]);
4432 			break;
4433 
4434 		case DIF_OP_STB:
4435 			if (!dtrace_canstore(regs[rd], 1, mstate, vstate)) {
4436 				*flags |= CPU_DTRACE_BADADDR;
4437 				*illval = regs[rd];
4438 				break;
4439 			}
4440 			*((uint8_t *)(uintptr_t)regs[rd]) = (uint8_t)regs[r1];
4441 			break;
4442 
4443 		case DIF_OP_STH:
4444 			if (!dtrace_canstore(regs[rd], 2, mstate, vstate)) {
4445 				*flags |= CPU_DTRACE_BADADDR;
4446 				*illval = regs[rd];
4447 				break;
4448 			}
4449 			if (regs[rd] & 1) {
4450 				*flags |= CPU_DTRACE_BADALIGN;
4451 				*illval = regs[rd];
4452 				break;
4453 			}
4454 			*((uint16_t *)(uintptr_t)regs[rd]) = (uint16_t)regs[r1];
4455 			break;
4456 
4457 		case DIF_OP_STW:
4458 			if (!dtrace_canstore(regs[rd], 4, mstate, vstate)) {
4459 				*flags |= CPU_DTRACE_BADADDR;
4460 				*illval = regs[rd];
4461 				break;
4462 			}
4463 			if (regs[rd] & 3) {
4464 				*flags |= CPU_DTRACE_BADALIGN;
4465 				*illval = regs[rd];
4466 				break;
4467 			}
4468 			*((uint32_t *)(uintptr_t)regs[rd]) = (uint32_t)regs[r1];
4469 			break;
4470 
4471 		case DIF_OP_STX:
4472 			if (!dtrace_canstore(regs[rd], 8, mstate, vstate)) {
4473 				*flags |= CPU_DTRACE_BADADDR;
4474 				*illval = regs[rd];
4475 				break;
4476 			}
4477 			if (regs[rd] & 7) {
4478 				*flags |= CPU_DTRACE_BADALIGN;
4479 				*illval = regs[rd];
4480 				break;
4481 			}
4482 			*((uint64_t *)(uintptr_t)regs[rd]) = regs[r1];
4483 			break;
4484 		}
4485 	}
4486 
4487 	if (!(*flags & CPU_DTRACE_FAULT))
4488 		return (rval);
4489 
4490 	mstate->dtms_fltoffs = opc * sizeof (dif_instr_t);
4491 	mstate->dtms_present |= DTRACE_MSTATE_FLTOFFS;
4492 
4493 	return (0);
4494 }
4495 
4496 static void
4497 dtrace_action_breakpoint(dtrace_ecb_t *ecb)
4498 {
4499 	dtrace_probe_t *probe = ecb->dte_probe;
4500 	dtrace_provider_t *prov = probe->dtpr_provider;
4501 	char c[DTRACE_FULLNAMELEN + 80], *str;
4502 	char *msg = "dtrace: breakpoint action at probe ";
4503 	char *ecbmsg = " (ecb ";
4504 	uintptr_t mask = (0xf << (sizeof (uintptr_t) * NBBY / 4));
4505 	uintptr_t val = (uintptr_t)ecb;
4506 	int shift = (sizeof (uintptr_t) * NBBY) - 4, i = 0;
4507 
4508 	if (dtrace_destructive_disallow)
4509 		return;
4510 
4511 	/*
4512 	 * It's impossible to be taking action on the NULL probe.
4513 	 */
4514 	ASSERT(probe != NULL);
4515 
4516 	/*
4517 	 * This is a poor man's (destitute man's?) sprintf():  we want to
4518 	 * print the provider name, module name, function name and name of
4519 	 * the probe, along with the hex address of the ECB with the breakpoint
4520 	 * action -- all of which we must place in the character buffer by
4521 	 * hand.
4522 	 */
4523 	while (*msg != '\0')
4524 		c[i++] = *msg++;
4525 
4526 	for (str = prov->dtpv_name; *str != '\0'; str++)
4527 		c[i++] = *str;
4528 	c[i++] = ':';
4529 
4530 	for (str = probe->dtpr_mod; *str != '\0'; str++)
4531 		c[i++] = *str;
4532 	c[i++] = ':';
4533 
4534 	for (str = probe->dtpr_func; *str != '\0'; str++)
4535 		c[i++] = *str;
4536 	c[i++] = ':';
4537 
4538 	for (str = probe->dtpr_name; *str != '\0'; str++)
4539 		c[i++] = *str;
4540 
4541 	while (*ecbmsg != '\0')
4542 		c[i++] = *ecbmsg++;
4543 
4544 	while (shift >= 0) {
4545 		mask = (uintptr_t)0xf << shift;
4546 
4547 		if (val >= ((uintptr_t)1 << shift))
4548 			c[i++] = "0123456789abcdef"[(val & mask) >> shift];
4549 		shift -= 4;
4550 	}
4551 
4552 	c[i++] = ')';
4553 	c[i] = '\0';
4554 
4555 	debug_enter(c);
4556 }
4557 
4558 static void
4559 dtrace_action_panic(dtrace_ecb_t *ecb)
4560 {
4561 	dtrace_probe_t *probe = ecb->dte_probe;
4562 
4563 	/*
4564 	 * It's impossible to be taking action on the NULL probe.
4565 	 */
4566 	ASSERT(probe != NULL);
4567 
4568 	if (dtrace_destructive_disallow)
4569 		return;
4570 
4571 	if (dtrace_panicked != NULL)
4572 		return;
4573 
4574 	if (dtrace_casptr(&dtrace_panicked, NULL, curthread) != NULL)
4575 		return;
4576 
4577 	/*
4578 	 * We won the right to panic.  (We want to be sure that only one
4579 	 * thread calls panic() from dtrace_probe(), and that panic() is
4580 	 * called exactly once.)
4581 	 */
4582 	dtrace_panic("dtrace: panic action at probe %s:%s:%s:%s (ecb %p)",
4583 	    probe->dtpr_provider->dtpv_name, probe->dtpr_mod,
4584 	    probe->dtpr_func, probe->dtpr_name, (void *)ecb);
4585 }
4586 
4587 static void
4588 dtrace_action_raise(uint64_t sig)
4589 {
4590 	if (dtrace_destructive_disallow)
4591 		return;
4592 
4593 	if (sig >= NSIG) {
4594 		DTRACE_CPUFLAG_SET(CPU_DTRACE_ILLOP);
4595 		return;
4596 	}
4597 
4598 	/*
4599 	 * raise() has a queue depth of 1 -- we ignore all subsequent
4600 	 * invocations of the raise() action.
4601 	 */
4602 	if (curthread->t_dtrace_sig == 0)
4603 		curthread->t_dtrace_sig = (uint8_t)sig;
4604 
4605 	curthread->t_sig_check = 1;
4606 	aston(curthread);
4607 }
4608 
4609 static void
4610 dtrace_action_stop(void)
4611 {
4612 	if (dtrace_destructive_disallow)
4613 		return;
4614 
4615 	if (!curthread->t_dtrace_stop) {
4616 		curthread->t_dtrace_stop = 1;
4617 		curthread->t_sig_check = 1;
4618 		aston(curthread);
4619 	}
4620 }
4621 
4622 static void
4623 dtrace_action_chill(dtrace_mstate_t *mstate, hrtime_t val)
4624 {
4625 	hrtime_t now;
4626 	volatile uint16_t *flags;
4627 	cpu_t *cpu = CPU;
4628 
4629 	if (dtrace_destructive_disallow)
4630 		return;
4631 
4632 	flags = (volatile uint16_t *)&cpu_core[cpu->cpu_id].cpuc_dtrace_flags;
4633 
4634 	now = dtrace_gethrtime();
4635 
4636 	if (now - cpu->cpu_dtrace_chillmark > dtrace_chill_interval) {
4637 		/*
4638 		 * We need to advance the mark to the current time.
4639 		 */
4640 		cpu->cpu_dtrace_chillmark = now;
4641 		cpu->cpu_dtrace_chilled = 0;
4642 	}
4643 
4644 	/*
4645 	 * Now check to see if the requested chill time would take us over
4646 	 * the maximum amount of time allowed in the chill interval.  (Or
4647 	 * worse, if the calculation itself induces overflow.)
4648 	 */
4649 	if (cpu->cpu_dtrace_chilled + val > dtrace_chill_max ||
4650 	    cpu->cpu_dtrace_chilled + val < cpu->cpu_dtrace_chilled) {
4651 		*flags |= CPU_DTRACE_ILLOP;
4652 		return;
4653 	}
4654 
4655 	while (dtrace_gethrtime() - now < val)
4656 		continue;
4657 
4658 	/*
4659 	 * Normally, we assure that the value of the variable "timestamp" does
4660 	 * not change within an ECB.  The presence of chill() represents an
4661 	 * exception to this rule, however.
4662 	 */
4663 	mstate->dtms_present &= ~DTRACE_MSTATE_TIMESTAMP;
4664 	cpu->cpu_dtrace_chilled += val;
4665 }
4666 
4667 static void
4668 dtrace_action_ustack(dtrace_mstate_t *mstate, dtrace_state_t *state,
4669     uint64_t *buf, uint64_t arg)
4670 {
4671 	int nframes = DTRACE_USTACK_NFRAMES(arg);
4672 	int strsize = DTRACE_USTACK_STRSIZE(arg);
4673 	uint64_t *pcs = &buf[1], *fps;
4674 	char *str = (char *)&pcs[nframes];
4675 	int size, offs = 0, i, j;
4676 	uintptr_t old = mstate->dtms_scratch_ptr, saved;
4677 	uint16_t *flags = &cpu_core[CPU->cpu_id].cpuc_dtrace_flags;
4678 	char *sym;
4679 
4680 	/*
4681 	 * Should be taking a faster path if string space has not been
4682 	 * allocated.
4683 	 */
4684 	ASSERT(strsize != 0);
4685 
4686 	/*
4687 	 * We will first allocate some temporary space for the frame pointers.
4688 	 */
4689 	fps = (uint64_t *)P2ROUNDUP(mstate->dtms_scratch_ptr, 8);
4690 	size = (uintptr_t)fps - mstate->dtms_scratch_ptr +
4691 	    (nframes * sizeof (uint64_t));
4692 
4693 	if (mstate->dtms_scratch_ptr + size >
4694 	    mstate->dtms_scratch_base + mstate->dtms_scratch_size) {
4695 		/*
4696 		 * Not enough room for our frame pointers -- need to indicate
4697 		 * that we ran out of scratch space.
4698 		 */
4699 		DTRACE_CPUFLAG_SET(CPU_DTRACE_NOSCRATCH);
4700 		return;
4701 	}
4702 
4703 	mstate->dtms_scratch_ptr += size;
4704 	saved = mstate->dtms_scratch_ptr;
4705 
4706 	/*
4707 	 * Now get a stack with both program counters and frame pointers.
4708 	 */
4709 	DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
4710 	dtrace_getufpstack(buf, fps, nframes + 1);
4711 	DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
4712 
4713 	/*
4714 	 * If that faulted, we're cooked.
4715 	 */
4716 	if (*flags & CPU_DTRACE_FAULT)
4717 		goto out;
4718 
4719 	/*
4720 	 * Now we want to walk up the stack, calling the USTACK helper.  For
4721 	 * each iteration, we restore the scratch pointer.
4722 	 */
4723 	for (i = 0; i < nframes; i++) {
4724 		mstate->dtms_scratch_ptr = saved;
4725 
4726 		if (offs >= strsize)
4727 			break;
4728 
4729 		sym = (char *)(uintptr_t)dtrace_helper(
4730 		    DTRACE_HELPER_ACTION_USTACK,
4731 		    mstate, state, pcs[i], fps[i]);
4732 
4733 		/*
4734 		 * If we faulted while running the helper, we're going to
4735 		 * clear the fault and null out the corresponding string.
4736 		 */
4737 		if (*flags & CPU_DTRACE_FAULT) {
4738 			*flags &= ~CPU_DTRACE_FAULT;
4739 			str[offs++] = '\0';
4740 			continue;
4741 		}
4742 
4743 		if (sym == NULL) {
4744 			str[offs++] = '\0';
4745 			continue;
4746 		}
4747 
4748 		DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
4749 
4750 		/*
4751 		 * Now copy in the string that the helper returned to us.
4752 		 */
4753 		for (j = 0; offs + j < strsize; j++) {
4754 			if ((str[offs + j] = sym[j]) == '\0')
4755 				break;
4756 		}
4757 
4758 		DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
4759 
4760 		offs += j + 1;
4761 	}
4762 
4763 	if (offs >= strsize) {
4764 		/*
4765 		 * If we didn't have room for all of the strings, we don't
4766 		 * abort processing -- this needn't be a fatal error -- but we
4767 		 * still want to increment a counter (dts_stkstroverflows) to
4768 		 * allow this condition to be warned about.  (If this is from
4769 		 * a jstack() action, it is easily tuned via jstackstrsize.)
4770 		 */
4771 		dtrace_error(&state->dts_stkstroverflows);
4772 	}
4773 
4774 	while (offs < strsize)
4775 		str[offs++] = '\0';
4776 
4777 out:
4778 	mstate->dtms_scratch_ptr = old;
4779 }
4780 
4781 /*
4782  * If you're looking for the epicenter of DTrace, you just found it.  This
4783  * is the function called by the provider to fire a probe -- from which all
4784  * subsequent probe-context DTrace activity emanates.
4785  */
4786 void
4787 dtrace_probe(dtrace_id_t id, uintptr_t arg0, uintptr_t arg1,
4788     uintptr_t arg2, uintptr_t arg3, uintptr_t arg4)
4789 {
4790 	processorid_t cpuid;
4791 	dtrace_icookie_t cookie;
4792 	dtrace_probe_t *probe;
4793 	dtrace_mstate_t mstate;
4794 	dtrace_ecb_t *ecb;
4795 	dtrace_action_t *act;
4796 	intptr_t offs;
4797 	size_t size;
4798 	int vtime, onintr;
4799 	volatile uint16_t *flags;
4800 	hrtime_t now;
4801 
4802 	/*
4803 	 * Kick out immediately if this CPU is still being born (in which case
4804 	 * curthread will be set to -1)
4805 	 */
4806 	if ((uintptr_t)curthread & 1)
4807 		return;
4808 
4809 	cookie = dtrace_interrupt_disable();
4810 	probe = dtrace_probes[id - 1];
4811 	cpuid = CPU->cpu_id;
4812 	onintr = CPU_ON_INTR(CPU);
4813 
4814 	if (!onintr && probe->dtpr_predcache != DTRACE_CACHEIDNONE &&
4815 	    probe->dtpr_predcache == curthread->t_predcache) {
4816 		/*
4817 		 * We have hit in the predicate cache; we know that
4818 		 * this predicate would evaluate to be false.
4819 		 */
4820 		dtrace_interrupt_enable(cookie);
4821 		return;
4822 	}
4823 
4824 	if (panic_quiesce) {
4825 		/*
4826 		 * We don't trace anything if we're panicking.
4827 		 */
4828 		dtrace_interrupt_enable(cookie);
4829 		return;
4830 	}
4831 
4832 	now = dtrace_gethrtime();
4833 	vtime = dtrace_vtime_references != 0;
4834 
4835 	if (vtime && curthread->t_dtrace_start)
4836 		curthread->t_dtrace_vtime += now - curthread->t_dtrace_start;
4837 
4838 	mstate.dtms_probe = probe;
4839 	mstate.dtms_arg[0] = arg0;
4840 	mstate.dtms_arg[1] = arg1;
4841 	mstate.dtms_arg[2] = arg2;
4842 	mstate.dtms_arg[3] = arg3;
4843 	mstate.dtms_arg[4] = arg4;
4844 
4845 	flags = (volatile uint16_t *)&cpu_core[cpuid].cpuc_dtrace_flags;
4846 
4847 	for (ecb = probe->dtpr_ecb; ecb != NULL; ecb = ecb->dte_next) {
4848 		dtrace_predicate_t *pred = ecb->dte_predicate;
4849 		dtrace_state_t *state = ecb->dte_state;
4850 		dtrace_buffer_t *buf = &state->dts_buffer[cpuid];
4851 		dtrace_buffer_t *aggbuf = &state->dts_aggbuffer[cpuid];
4852 		dtrace_vstate_t *vstate = &state->dts_vstate;
4853 		dtrace_provider_t *prov = probe->dtpr_provider;
4854 		int committed = 0;
4855 		caddr_t tomax;
4856 
4857 		/*
4858 		 * A little subtlety with the following (seemingly innocuous)
4859 		 * declaration of the automatic 'val':  by looking at the
4860 		 * code, you might think that it could be declared in the
4861 		 * action processing loop, below.  (That is, it's only used in
4862 		 * the action processing loop.)  However, it must be declared
4863 		 * out of that scope because in the case of DIF expression
4864 		 * arguments to aggregating actions, one iteration of the
4865 		 * action loop will use the last iteration's value.
4866 		 */
4867 #ifdef lint
4868 		uint64_t val = 0;
4869 #else
4870 		uint64_t val;
4871 #endif
4872 
4873 		mstate.dtms_present = DTRACE_MSTATE_ARGS | DTRACE_MSTATE_PROBE;
4874 		*flags &= ~CPU_DTRACE_ERROR;
4875 
4876 		if (prov == dtrace_provider) {
4877 			/*
4878 			 * If dtrace itself is the provider of this probe,
4879 			 * we're only going to continue processing the ECB if
4880 			 * arg0 (the dtrace_state_t) is equal to the ECB's
4881 			 * creating state.  (This prevents disjoint consumers
4882 			 * from seeing one another's metaprobes.)
4883 			 */
4884 			if (arg0 != (uint64_t)(uintptr_t)state)
4885 				continue;
4886 		}
4887 
4888 		if (state->dts_activity != DTRACE_ACTIVITY_ACTIVE) {
4889 			/*
4890 			 * We're not currently active.  If our provider isn't
4891 			 * the dtrace pseudo provider, we're not interested.
4892 			 */
4893 			if (prov != dtrace_provider)
4894 				continue;
4895 
4896 			/*
4897 			 * Now we must further check if we are in the BEGIN
4898 			 * probe.  If we are, we will only continue processing
4899 			 * if we're still in WARMUP -- if one BEGIN enabling
4900 			 * has invoked the exit() action, we don't want to
4901 			 * evaluate subsequent BEGIN enablings.
4902 			 */
4903 			if (probe->dtpr_id == dtrace_probeid_begin &&
4904 			    state->dts_activity != DTRACE_ACTIVITY_WARMUP) {
4905 				ASSERT(state->dts_activity ==
4906 				    DTRACE_ACTIVITY_DRAINING);
4907 				continue;
4908 			}
4909 		}
4910 
4911 		if (ecb->dte_cond) {
4912 			/*
4913 			 * If the dte_cond bits indicate that this
4914 			 * consumer is only allowed to see user-mode firings
4915 			 * of this probe, call the provider's dtps_usermode()
4916 			 * entry point to check that the probe was fired
4917 			 * while in a user context. Skip this ECB if that's
4918 			 * not the case.
4919 			 */
4920 			if ((ecb->dte_cond & DTRACE_COND_USERMODE) &&
4921 			    prov->dtpv_pops.dtps_usermode(prov->dtpv_arg,
4922 			    probe->dtpr_id, probe->dtpr_arg) == 0)
4923 				continue;
4924 
4925 			/*
4926 			 * This is more subtle than it looks. We have to be
4927 			 * absolutely certain that CRED() isn't going to
4928 			 * change out from under us so it's only legit to
4929 			 * examine that structure if we're in constrained
4930 			 * situations. Currently, the only times we'll this
4931 			 * check is if a non-super-user has enabled the
4932 			 * profile or syscall providers -- providers that
4933 			 * allow visibility of all processes. For the
4934 			 * profile case, the check above will ensure that
4935 			 * we're examining a user context.
4936 			 */
4937 			if (ecb->dte_cond & DTRACE_COND_OWNER) {
4938 				cred_t *cr;
4939 				cred_t *s_cr =
4940 				    ecb->dte_state->dts_cred.dcr_cred;
4941 				proc_t *proc;
4942 
4943 				ASSERT(s_cr != NULL);
4944 
4945 				if ((cr = CRED()) == NULL ||
4946 				    s_cr->cr_uid != cr->cr_uid ||
4947 				    s_cr->cr_uid != cr->cr_ruid ||
4948 				    s_cr->cr_uid != cr->cr_suid ||
4949 				    s_cr->cr_gid != cr->cr_gid ||
4950 				    s_cr->cr_gid != cr->cr_rgid ||
4951 				    s_cr->cr_gid != cr->cr_sgid ||
4952 				    (proc = ttoproc(curthread)) == NULL ||
4953 				    (proc->p_flag & SNOCD))
4954 					continue;
4955 			}
4956 
4957 			if (ecb->dte_cond & DTRACE_COND_ZONEOWNER) {
4958 				cred_t *cr;
4959 				cred_t *s_cr =
4960 				    ecb->dte_state->dts_cred.dcr_cred;
4961 
4962 				ASSERT(s_cr != NULL);
4963 
4964 				if ((cr = CRED()) == NULL ||
4965 				    s_cr->cr_zone->zone_id !=
4966 				    cr->cr_zone->zone_id)
4967 					continue;
4968 			}
4969 		}
4970 
4971 		if (now - state->dts_alive > dtrace_deadman_timeout) {
4972 			/*
4973 			 * We seem to be dead.  Unless we (a) have kernel
4974 			 * destructive permissions (b) have expicitly enabled
4975 			 * destructive actions and (c) destructive actions have
4976 			 * not been disabled, we're going to transition into
4977 			 * the KILLED state, from which no further processing
4978 			 * on this state will be performed.
4979 			 */
4980 			if (!dtrace_priv_kernel_destructive(state) ||
4981 			    !state->dts_cred.dcr_destructive ||
4982 			    dtrace_destructive_disallow) {
4983 				void *activity = &state->dts_activity;
4984 				dtrace_activity_t current;
4985 
4986 				do {
4987 					current = state->dts_activity;
4988 				} while (dtrace_cas32(activity, current,
4989 				    DTRACE_ACTIVITY_KILLED) != current);
4990 
4991 				continue;
4992 			}
4993 		}
4994 
4995 		if ((offs = dtrace_buffer_reserve(buf, ecb->dte_needed,
4996 		    ecb->dte_alignment, state, &mstate)) < 0)
4997 			continue;
4998 
4999 		tomax = buf->dtb_tomax;
5000 		ASSERT(tomax != NULL);
5001 
5002 		if (ecb->dte_size != 0)
5003 			DTRACE_STORE(uint32_t, tomax, offs, ecb->dte_epid);
5004 
5005 		mstate.dtms_epid = ecb->dte_epid;
5006 		mstate.dtms_present |= DTRACE_MSTATE_EPID;
5007 
5008 		if (pred != NULL) {
5009 			dtrace_difo_t *dp = pred->dtp_difo;
5010 			int rval;
5011 
5012 			rval = dtrace_dif_emulate(dp, &mstate, vstate, state);
5013 
5014 			if (!(*flags & CPU_DTRACE_ERROR) && !rval) {
5015 				dtrace_cacheid_t cid = probe->dtpr_predcache;
5016 
5017 				if (cid != DTRACE_CACHEIDNONE && !onintr) {
5018 					/*
5019 					 * Update the predicate cache...
5020 					 */
5021 					ASSERT(cid == pred->dtp_cacheid);
5022 					curthread->t_predcache = cid;
5023 				}
5024 
5025 				continue;
5026 			}
5027 		}
5028 
5029 		for (act = ecb->dte_action; !(*flags & CPU_DTRACE_ERROR) &&
5030 		    act != NULL; act = act->dta_next) {
5031 			size_t valoffs;
5032 			dtrace_difo_t *dp;
5033 			dtrace_recdesc_t *rec = &act->dta_rec;
5034 
5035 			size = rec->dtrd_size;
5036 			valoffs = offs + rec->dtrd_offset;
5037 
5038 			if (DTRACEACT_ISAGG(act->dta_kind)) {
5039 				uint64_t v = 0xbad;
5040 				dtrace_aggregation_t *agg;
5041 
5042 				agg = (dtrace_aggregation_t *)act;
5043 
5044 				if ((dp = act->dta_difo) != NULL)
5045 					v = dtrace_dif_emulate(dp,
5046 					    &mstate, vstate, state);
5047 
5048 				if (*flags & CPU_DTRACE_ERROR)
5049 					continue;
5050 
5051 				/*
5052 				 * Note that we always pass the expression
5053 				 * value from the previous iteration of the
5054 				 * action loop.  This value will only be used
5055 				 * if there is an expression argument to the
5056 				 * aggregating action, denoted by the
5057 				 * dtag_hasarg field.
5058 				 */
5059 				dtrace_aggregate(agg, buf,
5060 				    offs, aggbuf, v, val);
5061 				continue;
5062 			}
5063 
5064 			switch (act->dta_kind) {
5065 			case DTRACEACT_STOP:
5066 				if (dtrace_priv_proc_destructive(state))
5067 					dtrace_action_stop();
5068 				continue;
5069 
5070 			case DTRACEACT_BREAKPOINT:
5071 				if (dtrace_priv_kernel_destructive(state))
5072 					dtrace_action_breakpoint(ecb);
5073 				continue;
5074 
5075 			case DTRACEACT_PANIC:
5076 				if (dtrace_priv_kernel_destructive(state))
5077 					dtrace_action_panic(ecb);
5078 				continue;
5079 
5080 			case DTRACEACT_STACK:
5081 				if (!dtrace_priv_kernel(state))
5082 					continue;
5083 
5084 				dtrace_getpcstack((pc_t *)(tomax + valoffs),
5085 				    size / sizeof (pc_t), probe->dtpr_aframes,
5086 				    DTRACE_ANCHORED(probe) ? NULL :
5087 				    (uint32_t *)arg0);
5088 
5089 				continue;
5090 
5091 			case DTRACEACT_JSTACK:
5092 			case DTRACEACT_USTACK:
5093 				if (!dtrace_priv_proc(state))
5094 					continue;
5095 
5096 				/*
5097 				 * See comment in DIF_VAR_PID.
5098 				 */
5099 				if (DTRACE_ANCHORED(mstate.dtms_probe) &&
5100 				    CPU_ON_INTR(CPU)) {
5101 					int depth = DTRACE_USTACK_NFRAMES(
5102 					    rec->dtrd_arg) + 1;
5103 
5104 					dtrace_bzero((void *)(tomax + valoffs),
5105 					    DTRACE_USTACK_STRSIZE(rec->dtrd_arg)
5106 					    + depth * sizeof (uint64_t));
5107 
5108 					continue;
5109 				}
5110 
5111 				if (DTRACE_USTACK_STRSIZE(rec->dtrd_arg) != 0 &&
5112 				    curproc->p_dtrace_helpers != NULL) {
5113 					/*
5114 					 * This is the slow path -- we have
5115 					 * allocated string space, and we're
5116 					 * getting the stack of a process that
5117 					 * has helpers.  Call into a separate
5118 					 * routine to perform this processing.
5119 					 */
5120 					dtrace_action_ustack(&mstate, state,
5121 					    (uint64_t *)(tomax + valoffs),
5122 					    rec->dtrd_arg);
5123 					continue;
5124 				}
5125 
5126 				DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
5127 				dtrace_getupcstack((uint64_t *)
5128 				    (tomax + valoffs),
5129 				    DTRACE_USTACK_NFRAMES(rec->dtrd_arg) + 1);
5130 				DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
5131 				continue;
5132 
5133 			default:
5134 				break;
5135 			}
5136 
5137 			dp = act->dta_difo;
5138 			ASSERT(dp != NULL);
5139 
5140 			val = dtrace_dif_emulate(dp, &mstate, vstate, state);
5141 
5142 			if (*flags & CPU_DTRACE_ERROR)
5143 				continue;
5144 
5145 			switch (act->dta_kind) {
5146 			case DTRACEACT_SPECULATE:
5147 				ASSERT(buf == &state->dts_buffer[cpuid]);
5148 				buf = dtrace_speculation_buffer(state,
5149 				    cpuid, val);
5150 
5151 				if (buf == NULL) {
5152 					*flags |= CPU_DTRACE_DROP;
5153 					continue;
5154 				}
5155 
5156 				offs = dtrace_buffer_reserve(buf,
5157 				    ecb->dte_needed, ecb->dte_alignment,
5158 				    state, NULL);
5159 
5160 				if (offs < 0) {
5161 					*flags |= CPU_DTRACE_DROP;
5162 					continue;
5163 				}
5164 
5165 				tomax = buf->dtb_tomax;
5166 				ASSERT(tomax != NULL);
5167 
5168 				if (ecb->dte_size != 0)
5169 					DTRACE_STORE(uint32_t, tomax, offs,
5170 					    ecb->dte_epid);
5171 				continue;
5172 
5173 			case DTRACEACT_CHILL:
5174 				if (dtrace_priv_kernel_destructive(state))
5175 					dtrace_action_chill(&mstate, val);
5176 				continue;
5177 
5178 			case DTRACEACT_RAISE:
5179 				if (dtrace_priv_proc_destructive(state))
5180 					dtrace_action_raise(val);
5181 				continue;
5182 
5183 			case DTRACEACT_COMMIT:
5184 				ASSERT(!committed);
5185 
5186 				/*
5187 				 * We need to commit our buffer state.
5188 				 */
5189 				if (ecb->dte_size)
5190 					buf->dtb_offset = offs + ecb->dte_size;
5191 				buf = &state->dts_buffer[cpuid];
5192 				dtrace_speculation_commit(state, cpuid, val);
5193 				committed = 1;
5194 				continue;
5195 
5196 			case DTRACEACT_DISCARD:
5197 				dtrace_speculation_discard(state, cpuid, val);
5198 				continue;
5199 
5200 			case DTRACEACT_DIFEXPR:
5201 			case DTRACEACT_LIBACT:
5202 			case DTRACEACT_PRINTF:
5203 			case DTRACEACT_PRINTA:
5204 			case DTRACEACT_SYSTEM:
5205 			case DTRACEACT_FREOPEN:
5206 				break;
5207 
5208 			case DTRACEACT_SYM:
5209 			case DTRACEACT_MOD:
5210 				if (!dtrace_priv_kernel(state))
5211 					continue;
5212 				break;
5213 
5214 			case DTRACEACT_USYM:
5215 			case DTRACEACT_UMOD:
5216 			case DTRACEACT_UADDR: {
5217 				struct pid *pid = curthread->t_procp->p_pidp;
5218 
5219 				if (!dtrace_priv_proc(state))
5220 					continue;
5221 
5222 				DTRACE_STORE(uint64_t, tomax,
5223 				    valoffs, (uint64_t)pid->pid_id);
5224 				DTRACE_STORE(uint64_t, tomax,
5225 				    valoffs + sizeof (uint64_t), val);
5226 
5227 				continue;
5228 			}
5229 
5230 			case DTRACEACT_EXIT: {
5231 				/*
5232 				 * For the exit action, we are going to attempt
5233 				 * to atomically set our activity to be
5234 				 * draining.  If this fails (either because
5235 				 * another CPU has beat us to the exit action,
5236 				 * or because our current activity is something
5237 				 * other than ACTIVE or WARMUP), we will
5238 				 * continue.  This assures that the exit action
5239 				 * can be successfully recorded at most once
5240 				 * when we're in the ACTIVE state.  If we're
5241 				 * encountering the exit() action while in
5242 				 * COOLDOWN, however, we want to honor the new
5243 				 * status code.  (We know that we're the only
5244 				 * thread in COOLDOWN, so there is no race.)
5245 				 */
5246 				void *activity = &state->dts_activity;
5247 				dtrace_activity_t current = state->dts_activity;
5248 
5249 				if (current == DTRACE_ACTIVITY_COOLDOWN)
5250 					break;
5251 
5252 				if (current != DTRACE_ACTIVITY_WARMUP)
5253 					current = DTRACE_ACTIVITY_ACTIVE;
5254 
5255 				if (dtrace_cas32(activity, current,
5256 				    DTRACE_ACTIVITY_DRAINING) != current) {
5257 					*flags |= CPU_DTRACE_DROP;
5258 					continue;
5259 				}
5260 
5261 				break;
5262 			}
5263 
5264 			default:
5265 				ASSERT(0);
5266 			}
5267 
5268 			if (dp->dtdo_rtype.dtdt_flags & DIF_TF_BYREF) {
5269 				uintptr_t end = valoffs + size;
5270 
5271 				/*
5272 				 * If this is a string, we're going to only
5273 				 * load until we find the zero byte -- after
5274 				 * which we'll store zero bytes.
5275 				 */
5276 				if (dp->dtdo_rtype.dtdt_kind ==
5277 				    DIF_TYPE_STRING) {
5278 					char c = '\0' + 1;
5279 					int intuple = act->dta_intuple;
5280 					size_t s;
5281 
5282 					for (s = 0; s < size; s++) {
5283 						if (c != '\0')
5284 							c = dtrace_load8(val++);
5285 
5286 						DTRACE_STORE(uint8_t, tomax,
5287 						    valoffs++, c);
5288 
5289 						if (c == '\0' && intuple)
5290 							break;
5291 					}
5292 
5293 					continue;
5294 				}
5295 
5296 				while (valoffs < end) {
5297 					DTRACE_STORE(uint8_t, tomax, valoffs++,
5298 					    dtrace_load8(val++));
5299 				}
5300 
5301 				continue;
5302 			}
5303 
5304 			switch (size) {
5305 			case 0:
5306 				break;
5307 
5308 			case sizeof (uint8_t):
5309 				DTRACE_STORE(uint8_t, tomax, valoffs, val);
5310 				break;
5311 			case sizeof (uint16_t):
5312 				DTRACE_STORE(uint16_t, tomax, valoffs, val);
5313 				break;
5314 			case sizeof (uint32_t):
5315 				DTRACE_STORE(uint32_t, tomax, valoffs, val);
5316 				break;
5317 			case sizeof (uint64_t):
5318 				DTRACE_STORE(uint64_t, tomax, valoffs, val);
5319 				break;
5320 			default:
5321 				/*
5322 				 * Any other size should have been returned by
5323 				 * reference, not by value.
5324 				 */
5325 				ASSERT(0);
5326 				break;
5327 			}
5328 		}
5329 
5330 		if (*flags & CPU_DTRACE_DROP)
5331 			continue;
5332 
5333 		if (*flags & CPU_DTRACE_FAULT) {
5334 			int ndx;
5335 			dtrace_action_t *err;
5336 
5337 			buf->dtb_errors++;
5338 
5339 			if (probe->dtpr_id == dtrace_probeid_error) {
5340 				/*
5341 				 * There's nothing we can do -- we had an
5342 				 * error on the error probe.  We bump an
5343 				 * error counter to at least indicate that
5344 				 * this condition happened.
5345 				 */
5346 				dtrace_error(&state->dts_dblerrors);
5347 				continue;
5348 			}
5349 
5350 			if (vtime) {
5351 				/*
5352 				 * Before recursing on dtrace_probe(), we
5353 				 * need to explicitly clear out our start
5354 				 * time to prevent it from being accumulated
5355 				 * into t_dtrace_vtime.
5356 				 */
5357 				curthread->t_dtrace_start = 0;
5358 			}
5359 
5360 			/*
5361 			 * Iterate over the actions to figure out which action
5362 			 * we were processing when we experienced the error.
5363 			 * Note that act points _past_ the faulting action; if
5364 			 * act is ecb->dte_action, the fault was in the
5365 			 * predicate, if it's ecb->dte_action->dta_next it's
5366 			 * in action #1, and so on.
5367 			 */
5368 			for (err = ecb->dte_action, ndx = 0;
5369 			    err != act; err = err->dta_next, ndx++)
5370 				continue;
5371 
5372 			dtrace_probe_error(state, ecb->dte_epid, ndx,
5373 			    (mstate.dtms_present & DTRACE_MSTATE_FLTOFFS) ?
5374 			    mstate.dtms_fltoffs : -1, DTRACE_FLAGS2FLT(*flags),
5375 			    cpu_core[cpuid].cpuc_dtrace_illval);
5376 
5377 			continue;
5378 		}
5379 
5380 		if (!committed)
5381 			buf->dtb_offset = offs + ecb->dte_size;
5382 	}
5383 
5384 	if (vtime)
5385 		curthread->t_dtrace_start = dtrace_gethrtime();
5386 
5387 	dtrace_interrupt_enable(cookie);
5388 }
5389 
5390 /*
5391  * DTrace Probe Hashing Functions
5392  *
5393  * The functions in this section (and indeed, the functions in remaining
5394  * sections) are not _called_ from probe context.  (Any exceptions to this are
5395  * marked with a "Note:".)  Rather, they are called from elsewhere in the
5396  * DTrace framework to look-up probes in, add probes to and remove probes from
5397  * the DTrace probe hashes.  (Each probe is hashed by each element of the
5398  * probe tuple -- allowing for fast lookups, regardless of what was
5399  * specified.)
5400  */
5401 static uint_t
5402 dtrace_hash_str(char *p)
5403 {
5404 	unsigned int g;
5405 	uint_t hval = 0;
5406 
5407 	while (*p) {
5408 		hval = (hval << 4) + *p++;
5409 		if ((g = (hval & 0xf0000000)) != 0)
5410 			hval ^= g >> 24;
5411 		hval &= ~g;
5412 	}
5413 	return (hval);
5414 }
5415 
5416 static dtrace_hash_t *
5417 dtrace_hash_create(uintptr_t stroffs, uintptr_t nextoffs, uintptr_t prevoffs)
5418 {
5419 	dtrace_hash_t *hash = kmem_zalloc(sizeof (dtrace_hash_t), KM_SLEEP);
5420 
5421 	hash->dth_stroffs = stroffs;
5422 	hash->dth_nextoffs = nextoffs;
5423 	hash->dth_prevoffs = prevoffs;
5424 
5425 	hash->dth_size = 1;
5426 	hash->dth_mask = hash->dth_size - 1;
5427 
5428 	hash->dth_tab = kmem_zalloc(hash->dth_size *
5429 	    sizeof (dtrace_hashbucket_t *), KM_SLEEP);
5430 
5431 	return (hash);
5432 }
5433 
5434 static void
5435 dtrace_hash_destroy(dtrace_hash_t *hash)
5436 {
5437 #ifdef DEBUG
5438 	int i;
5439 
5440 	for (i = 0; i < hash->dth_size; i++)
5441 		ASSERT(hash->dth_tab[i] == NULL);
5442 #endif
5443 
5444 	kmem_free(hash->dth_tab,
5445 	    hash->dth_size * sizeof (dtrace_hashbucket_t *));
5446 	kmem_free(hash, sizeof (dtrace_hash_t));
5447 }
5448 
5449 static void
5450 dtrace_hash_resize(dtrace_hash_t *hash)
5451 {
5452 	int size = hash->dth_size, i, ndx;
5453 	int new_size = hash->dth_size << 1;
5454 	int new_mask = new_size - 1;
5455 	dtrace_hashbucket_t **new_tab, *bucket, *next;
5456 
5457 	ASSERT((new_size & new_mask) == 0);
5458 
5459 	new_tab = kmem_zalloc(new_size * sizeof (void *), KM_SLEEP);
5460 
5461 	for (i = 0; i < size; i++) {
5462 		for (bucket = hash->dth_tab[i]; bucket != NULL; bucket = next) {
5463 			dtrace_probe_t *probe = bucket->dthb_chain;
5464 
5465 			ASSERT(probe != NULL);
5466 			ndx = DTRACE_HASHSTR(hash, probe) & new_mask;
5467 
5468 			next = bucket->dthb_next;
5469 			bucket->dthb_next = new_tab[ndx];
5470 			new_tab[ndx] = bucket;
5471 		}
5472 	}
5473 
5474 	kmem_free(hash->dth_tab, hash->dth_size * sizeof (void *));
5475 	hash->dth_tab = new_tab;
5476 	hash->dth_size = new_size;
5477 	hash->dth_mask = new_mask;
5478 }
5479 
5480 static void
5481 dtrace_hash_add(dtrace_hash_t *hash, dtrace_probe_t *new)
5482 {
5483 	int hashval = DTRACE_HASHSTR(hash, new);
5484 	int ndx = hashval & hash->dth_mask;
5485 	dtrace_hashbucket_t *bucket = hash->dth_tab[ndx];
5486 	dtrace_probe_t **nextp, **prevp;
5487 
5488 	for (; bucket != NULL; bucket = bucket->dthb_next) {
5489 		if (DTRACE_HASHEQ(hash, bucket->dthb_chain, new))
5490 			goto add;
5491 	}
5492 
5493 	if ((hash->dth_nbuckets >> 1) > hash->dth_size) {
5494 		dtrace_hash_resize(hash);
5495 		dtrace_hash_add(hash, new);
5496 		return;
5497 	}
5498 
5499 	bucket = kmem_zalloc(sizeof (dtrace_hashbucket_t), KM_SLEEP);
5500 	bucket->dthb_next = hash->dth_tab[ndx];
5501 	hash->dth_tab[ndx] = bucket;
5502 	hash->dth_nbuckets++;
5503 
5504 add:
5505 	nextp = DTRACE_HASHNEXT(hash, new);
5506 	ASSERT(*nextp == NULL && *(DTRACE_HASHPREV(hash, new)) == NULL);
5507 	*nextp = bucket->dthb_chain;
5508 
5509 	if (bucket->dthb_chain != NULL) {
5510 		prevp = DTRACE_HASHPREV(hash, bucket->dthb_chain);
5511 		ASSERT(*prevp == NULL);
5512 		*prevp = new;
5513 	}
5514 
5515 	bucket->dthb_chain = new;
5516 	bucket->dthb_len++;
5517 }
5518 
5519 static dtrace_probe_t *
5520 dtrace_hash_lookup(dtrace_hash_t *hash, dtrace_probe_t *template)
5521 {
5522 	int hashval = DTRACE_HASHSTR(hash, template);
5523 	int ndx = hashval & hash->dth_mask;
5524 	dtrace_hashbucket_t *bucket = hash->dth_tab[ndx];
5525 
5526 	for (; bucket != NULL; bucket = bucket->dthb_next) {
5527 		if (DTRACE_HASHEQ(hash, bucket->dthb_chain, template))
5528 			return (bucket->dthb_chain);
5529 	}
5530 
5531 	return (NULL);
5532 }
5533 
5534 static int
5535 dtrace_hash_collisions(dtrace_hash_t *hash, dtrace_probe_t *template)
5536 {
5537 	int hashval = DTRACE_HASHSTR(hash, template);
5538 	int ndx = hashval & hash->dth_mask;
5539 	dtrace_hashbucket_t *bucket = hash->dth_tab[ndx];
5540 
5541 	for (; bucket != NULL; bucket = bucket->dthb_next) {
5542 		if (DTRACE_HASHEQ(hash, bucket->dthb_chain, template))
5543 			return (bucket->dthb_len);
5544 	}
5545 
5546 	return (NULL);
5547 }
5548 
5549 static void
5550 dtrace_hash_remove(dtrace_hash_t *hash, dtrace_probe_t *probe)
5551 {
5552 	int ndx = DTRACE_HASHSTR(hash, probe) & hash->dth_mask;
5553 	dtrace_hashbucket_t *bucket = hash->dth_tab[ndx];
5554 
5555 	dtrace_probe_t **prevp = DTRACE_HASHPREV(hash, probe);
5556 	dtrace_probe_t **nextp = DTRACE_HASHNEXT(hash, probe);
5557 
5558 	/*
5559 	 * Find the bucket that we're removing this probe from.
5560 	 */
5561 	for (; bucket != NULL; bucket = bucket->dthb_next) {
5562 		if (DTRACE_HASHEQ(hash, bucket->dthb_chain, probe))
5563 			break;
5564 	}
5565 
5566 	ASSERT(bucket != NULL);
5567 
5568 	if (*prevp == NULL) {
5569 		if (*nextp == NULL) {
5570 			/*
5571 			 * The removed probe was the only probe on this
5572 			 * bucket; we need to remove the bucket.
5573 			 */
5574 			dtrace_hashbucket_t *b = hash->dth_tab[ndx];
5575 
5576 			ASSERT(bucket->dthb_chain == probe);
5577 			ASSERT(b != NULL);
5578 
5579 			if (b == bucket) {
5580 				hash->dth_tab[ndx] = bucket->dthb_next;
5581 			} else {
5582 				while (b->dthb_next != bucket)
5583 					b = b->dthb_next;
5584 				b->dthb_next = bucket->dthb_next;
5585 			}
5586 
5587 			ASSERT(hash->dth_nbuckets > 0);
5588 			hash->dth_nbuckets--;
5589 			kmem_free(bucket, sizeof (dtrace_hashbucket_t));
5590 			return;
5591 		}
5592 
5593 		bucket->dthb_chain = *nextp;
5594 	} else {
5595 		*(DTRACE_HASHNEXT(hash, *prevp)) = *nextp;
5596 	}
5597 
5598 	if (*nextp != NULL)
5599 		*(DTRACE_HASHPREV(hash, *nextp)) = *prevp;
5600 }
5601 
5602 /*
5603  * DTrace Utility Functions
5604  *
5605  * These are random utility functions that are _not_ called from probe context.
5606  */
5607 static int
5608 dtrace_badattr(const dtrace_attribute_t *a)
5609 {
5610 	return (a->dtat_name > DTRACE_STABILITY_MAX ||
5611 	    a->dtat_data > DTRACE_STABILITY_MAX ||
5612 	    a->dtat_class > DTRACE_CLASS_MAX);
5613 }
5614 
5615 /*
5616  * Return a duplicate copy of a string.  If the specified string is NULL,
5617  * this function returns a zero-length string.
5618  */
5619 static char *
5620 dtrace_strdup(const char *str)
5621 {
5622 	char *new = kmem_zalloc((str != NULL ? strlen(str) : 0) + 1, KM_SLEEP);
5623 
5624 	if (str != NULL)
5625 		(void) strcpy(new, str);
5626 
5627 	return (new);
5628 }
5629 
5630 #define	DTRACE_ISALPHA(c)	\
5631 	(((c) >= 'a' && (c) <= 'z') || ((c) >= 'A' && (c) <= 'Z'))
5632 
5633 static int
5634 dtrace_badname(const char *s)
5635 {
5636 	char c;
5637 
5638 	if (s == NULL || (c = *s++) == '\0')
5639 		return (0);
5640 
5641 	if (!DTRACE_ISALPHA(c) && c != '-' && c != '_' && c != '.')
5642 		return (1);
5643 
5644 	while ((c = *s++) != '\0') {
5645 		if (!DTRACE_ISALPHA(c) && (c < '0' || c > '9') &&
5646 		    c != '-' && c != '_' && c != '.' && c != '`')
5647 			return (1);
5648 	}
5649 
5650 	return (0);
5651 }
5652 
5653 static void
5654 dtrace_cred2priv(cred_t *cr, uint32_t *privp, uid_t *uidp, zoneid_t *zoneidp)
5655 {
5656 	uint32_t priv;
5657 
5658 	if (cr == NULL || PRIV_POLICY_ONLY(cr, PRIV_ALL, B_FALSE)) {
5659 		/*
5660 		 * For DTRACE_PRIV_ALL, the uid and zoneid don't matter.
5661 		 */
5662 		priv = DTRACE_PRIV_ALL;
5663 	} else {
5664 		*uidp = crgetuid(cr);
5665 		*zoneidp = crgetzoneid(cr);
5666 
5667 		priv = 0;
5668 		if (PRIV_POLICY_ONLY(cr, PRIV_DTRACE_KERNEL, B_FALSE))
5669 			priv |= DTRACE_PRIV_KERNEL | DTRACE_PRIV_USER;
5670 		else if (PRIV_POLICY_ONLY(cr, PRIV_DTRACE_USER, B_FALSE))
5671 			priv |= DTRACE_PRIV_USER;
5672 		if (PRIV_POLICY_ONLY(cr, PRIV_DTRACE_PROC, B_FALSE))
5673 			priv |= DTRACE_PRIV_PROC;
5674 		if (PRIV_POLICY_ONLY(cr, PRIV_PROC_OWNER, B_FALSE))
5675 			priv |= DTRACE_PRIV_OWNER;
5676 		if (PRIV_POLICY_ONLY(cr, PRIV_PROC_ZONE, B_FALSE))
5677 			priv |= DTRACE_PRIV_ZONEOWNER;
5678 	}
5679 
5680 	*privp = priv;
5681 }
5682 
5683 #ifdef DTRACE_ERRDEBUG
5684 static void
5685 dtrace_errdebug(const char *str)
5686 {
5687 	int hval = dtrace_hash_str((char *)str) % DTRACE_ERRHASHSZ;
5688 	int occupied = 0;
5689 
5690 	mutex_enter(&dtrace_errlock);
5691 	dtrace_errlast = str;
5692 	dtrace_errthread = curthread;
5693 
5694 	while (occupied++ < DTRACE_ERRHASHSZ) {
5695 		if (dtrace_errhash[hval].dter_msg == str) {
5696 			dtrace_errhash[hval].dter_count++;
5697 			goto out;
5698 		}
5699 
5700 		if (dtrace_errhash[hval].dter_msg != NULL) {
5701 			hval = (hval + 1) % DTRACE_ERRHASHSZ;
5702 			continue;
5703 		}
5704 
5705 		dtrace_errhash[hval].dter_msg = str;
5706 		dtrace_errhash[hval].dter_count = 1;
5707 		goto out;
5708 	}
5709 
5710 	panic("dtrace: undersized error hash");
5711 out:
5712 	mutex_exit(&dtrace_errlock);
5713 }
5714 #endif
5715 
5716 /*
5717  * DTrace Matching Functions
5718  *
5719  * These functions are used to match groups of probes, given some elements of
5720  * a probe tuple, or some globbed expressions for elements of a probe tuple.
5721  */
5722 static int
5723 dtrace_match_priv(const dtrace_probe_t *prp, uint32_t priv, uid_t uid,
5724     zoneid_t zoneid)
5725 {
5726 	if (priv != DTRACE_PRIV_ALL) {
5727 		uint32_t ppriv = prp->dtpr_provider->dtpv_priv.dtpp_flags;
5728 		uint32_t match = priv & ppriv;
5729 
5730 		/*
5731 		 * No PRIV_DTRACE_* privileges...
5732 		 */
5733 		if ((priv & (DTRACE_PRIV_PROC | DTRACE_PRIV_USER |
5734 		    DTRACE_PRIV_KERNEL)) == 0)
5735 			return (0);
5736 
5737 		/*
5738 		 * No matching bits, but there were bits to match...
5739 		 */
5740 		if (match == 0 && ppriv != 0)
5741 			return (0);
5742 
5743 		/*
5744 		 * Need to have permissions to the process, but don't...
5745 		 */
5746 		if (((ppriv & ~match) & DTRACE_PRIV_OWNER) != 0 &&
5747 		    uid != prp->dtpr_provider->dtpv_priv.dtpp_uid) {
5748 			return (0);
5749 		}
5750 
5751 		/*
5752 		 * Need to be in the same zone unless we possess the
5753 		 * privilege to examine all zones.
5754 		 */
5755 		if (((ppriv & ~match) & DTRACE_PRIV_ZONEOWNER) != 0 &&
5756 		    zoneid != prp->dtpr_provider->dtpv_priv.dtpp_zoneid) {
5757 			return (0);
5758 		}
5759 	}
5760 
5761 	return (1);
5762 }
5763 
5764 /*
5765  * dtrace_match_probe compares a dtrace_probe_t to a pre-compiled key, which
5766  * consists of input pattern strings and an ops-vector to evaluate them.
5767  * This function returns >0 for match, 0 for no match, and <0 for error.
5768  */
5769 static int
5770 dtrace_match_probe(const dtrace_probe_t *prp, const dtrace_probekey_t *pkp,
5771     uint32_t priv, uid_t uid, zoneid_t zoneid)
5772 {
5773 	dtrace_provider_t *pvp = prp->dtpr_provider;
5774 	int rv;
5775 
5776 	if (pvp->dtpv_defunct)
5777 		return (0);
5778 
5779 	if ((rv = pkp->dtpk_pmatch(pvp->dtpv_name, pkp->dtpk_prov, 0)) <= 0)
5780 		return (rv);
5781 
5782 	if ((rv = pkp->dtpk_mmatch(prp->dtpr_mod, pkp->dtpk_mod, 0)) <= 0)
5783 		return (rv);
5784 
5785 	if ((rv = pkp->dtpk_fmatch(prp->dtpr_func, pkp->dtpk_func, 0)) <= 0)
5786 		return (rv);
5787 
5788 	if ((rv = pkp->dtpk_nmatch(prp->dtpr_name, pkp->dtpk_name, 0)) <= 0)
5789 		return (rv);
5790 
5791 	if (dtrace_match_priv(prp, priv, uid, zoneid) == 0)
5792 		return (0);
5793 
5794 	return (rv);
5795 }
5796 
5797 /*
5798  * dtrace_match_glob() is a safe kernel implementation of the gmatch(3GEN)
5799  * interface for matching a glob pattern 'p' to an input string 's'.  Unlike
5800  * libc's version, the kernel version only applies to 8-bit ASCII strings.
5801  * In addition, all of the recursion cases except for '*' matching have been
5802  * unwound.  For '*', we still implement recursive evaluation, but a depth
5803  * counter is maintained and matching is aborted if we recurse too deep.
5804  * The function returns 0 if no match, >0 if match, and <0 if recursion error.
5805  */
5806 static int
5807 dtrace_match_glob(const char *s, const char *p, int depth)
5808 {
5809 	const char *olds;
5810 	char s1, c;
5811 	int gs;
5812 
5813 	if (depth > DTRACE_PROBEKEY_MAXDEPTH)
5814 		return (-1);
5815 
5816 	if (s == NULL)
5817 		s = ""; /* treat NULL as empty string */
5818 
5819 top:
5820 	olds = s;
5821 	s1 = *s++;
5822 
5823 	if (p == NULL)
5824 		return (0);
5825 
5826 	if ((c = *p++) == '\0')
5827 		return (s1 == '\0');
5828 
5829 	switch (c) {
5830 	case '[': {
5831 		int ok = 0, notflag = 0;
5832 		char lc = '\0';
5833 
5834 		if (s1 == '\0')
5835 			return (0);
5836 
5837 		if (*p == '!') {
5838 			notflag = 1;
5839 			p++;
5840 		}
5841 
5842 		if ((c = *p++) == '\0')
5843 			return (0);
5844 
5845 		do {
5846 			if (c == '-' && lc != '\0' && *p != ']') {
5847 				if ((c = *p++) == '\0')
5848 					return (0);
5849 				if (c == '\\' && (c = *p++) == '\0')
5850 					return (0);
5851 
5852 				if (notflag) {
5853 					if (s1 < lc || s1 > c)
5854 						ok++;
5855 					else
5856 						return (0);
5857 				} else if (lc <= s1 && s1 <= c)
5858 					ok++;
5859 
5860 			} else if (c == '\\' && (c = *p++) == '\0')
5861 				return (0);
5862 
5863 			lc = c; /* save left-hand 'c' for next iteration */
5864 
5865 			if (notflag) {
5866 				if (s1 != c)
5867 					ok++;
5868 				else
5869 					return (0);
5870 			} else if (s1 == c)
5871 				ok++;
5872 
5873 			if ((c = *p++) == '\0')
5874 				return (0);
5875 
5876 		} while (c != ']');
5877 
5878 		if (ok)
5879 			goto top;
5880 
5881 		return (0);
5882 	}
5883 
5884 	case '\\':
5885 		if ((c = *p++) == '\0')
5886 			return (0);
5887 		/*FALLTHRU*/
5888 
5889 	default:
5890 		if (c != s1)
5891 			return (0);
5892 		/*FALLTHRU*/
5893 
5894 	case '?':
5895 		if (s1 != '\0')
5896 			goto top;
5897 		return (0);
5898 
5899 	case '*':
5900 		while (*p == '*')
5901 			p++; /* consecutive *'s are identical to a single one */
5902 
5903 		if (*p == '\0')
5904 			return (1);
5905 
5906 		for (s = olds; *s != '\0'; s++) {
5907 			if ((gs = dtrace_match_glob(s, p, depth + 1)) != 0)
5908 				return (gs);
5909 		}
5910 
5911 		return (0);
5912 	}
5913 }
5914 
5915 /*ARGSUSED*/
5916 static int
5917 dtrace_match_string(const char *s, const char *p, int depth)
5918 {
5919 	return (s != NULL && strcmp(s, p) == 0);
5920 }
5921 
5922 /*ARGSUSED*/
5923 static int
5924 dtrace_match_nul(const char *s, const char *p, int depth)
5925 {
5926 	return (1); /* always match the empty pattern */
5927 }
5928 
5929 /*ARGSUSED*/
5930 static int
5931 dtrace_match_nonzero(const char *s, const char *p, int depth)
5932 {
5933 	return (s != NULL && s[0] != '\0');
5934 }
5935 
5936 static int
5937 dtrace_match(const dtrace_probekey_t *pkp, uint32_t priv, uid_t uid,
5938     zoneid_t zoneid, int (*matched)(dtrace_probe_t *, void *), void *arg)
5939 {
5940 	dtrace_probe_t template, *probe;
5941 	dtrace_hash_t *hash = NULL;
5942 	int len, best = INT_MAX, nmatched = 0;
5943 	dtrace_id_t i;
5944 
5945 	ASSERT(MUTEX_HELD(&dtrace_lock));
5946 
5947 	/*
5948 	 * If the probe ID is specified in the key, just lookup by ID and
5949 	 * invoke the match callback once if a matching probe is found.
5950 	 */
5951 	if (pkp->dtpk_id != DTRACE_IDNONE) {
5952 		if ((probe = dtrace_probe_lookup_id(pkp->dtpk_id)) != NULL &&
5953 		    dtrace_match_probe(probe, pkp, priv, uid, zoneid) > 0) {
5954 			(void) (*matched)(probe, arg);
5955 			nmatched++;
5956 		}
5957 		return (nmatched);
5958 	}
5959 
5960 	template.dtpr_mod = (char *)pkp->dtpk_mod;
5961 	template.dtpr_func = (char *)pkp->dtpk_func;
5962 	template.dtpr_name = (char *)pkp->dtpk_name;
5963 
5964 	/*
5965 	 * We want to find the most distinct of the module name, function
5966 	 * name, and name.  So for each one that is not a glob pattern or
5967 	 * empty string, we perform a lookup in the corresponding hash and
5968 	 * use the hash table with the fewest collisions to do our search.
5969 	 */
5970 	if (pkp->dtpk_mmatch == &dtrace_match_string &&
5971 	    (len = dtrace_hash_collisions(dtrace_bymod, &template)) < best) {
5972 		best = len;
5973 		hash = dtrace_bymod;
5974 	}
5975 
5976 	if (pkp->dtpk_fmatch == &dtrace_match_string &&
5977 	    (len = dtrace_hash_collisions(dtrace_byfunc, &template)) < best) {
5978 		best = len;
5979 		hash = dtrace_byfunc;
5980 	}
5981 
5982 	if (pkp->dtpk_nmatch == &dtrace_match_string &&
5983 	    (len = dtrace_hash_collisions(dtrace_byname, &template)) < best) {
5984 		best = len;
5985 		hash = dtrace_byname;
5986 	}
5987 
5988 	/*
5989 	 * If we did not select a hash table, iterate over every probe and
5990 	 * invoke our callback for each one that matches our input probe key.
5991 	 */
5992 	if (hash == NULL) {
5993 		for (i = 0; i < dtrace_nprobes; i++) {
5994 			if ((probe = dtrace_probes[i]) == NULL ||
5995 			    dtrace_match_probe(probe, pkp, priv, uid,
5996 			    zoneid) <= 0)
5997 				continue;
5998 
5999 			nmatched++;
6000 
6001 			if ((*matched)(probe, arg) != DTRACE_MATCH_NEXT)
6002 				break;
6003 		}
6004 
6005 		return (nmatched);
6006 	}
6007 
6008 	/*
6009 	 * If we selected a hash table, iterate over each probe of the same key
6010 	 * name and invoke the callback for every probe that matches the other
6011 	 * attributes of our input probe key.
6012 	 */
6013 	for (probe = dtrace_hash_lookup(hash, &template); probe != NULL;
6014 	    probe = *(DTRACE_HASHNEXT(hash, probe))) {
6015 
6016 		if (dtrace_match_probe(probe, pkp, priv, uid, zoneid) <= 0)
6017 			continue;
6018 
6019 		nmatched++;
6020 
6021 		if ((*matched)(probe, arg) != DTRACE_MATCH_NEXT)
6022 			break;
6023 	}
6024 
6025 	return (nmatched);
6026 }
6027 
6028 /*
6029  * Return the function pointer dtrace_probecmp() should use to compare the
6030  * specified pattern with a string.  For NULL or empty patterns, we select
6031  * dtrace_match_nul().  For glob pattern strings, we use dtrace_match_glob().
6032  * For non-empty non-glob strings, we use dtrace_match_string().
6033  */
6034 static dtrace_probekey_f *
6035 dtrace_probekey_func(const char *p)
6036 {
6037 	char c;
6038 
6039 	if (p == NULL || *p == '\0')
6040 		return (&dtrace_match_nul);
6041 
6042 	while ((c = *p++) != '\0') {
6043 		if (c == '[' || c == '?' || c == '*' || c == '\\')
6044 			return (&dtrace_match_glob);
6045 	}
6046 
6047 	return (&dtrace_match_string);
6048 }
6049 
6050 /*
6051  * Build a probe comparison key for use with dtrace_match_probe() from the
6052  * given probe description.  By convention, a null key only matches anchored
6053  * probes: if each field is the empty string, reset dtpk_fmatch to
6054  * dtrace_match_nonzero().
6055  */
6056 static void
6057 dtrace_probekey(const dtrace_probedesc_t *pdp, dtrace_probekey_t *pkp)
6058 {
6059 	pkp->dtpk_prov = pdp->dtpd_provider;
6060 	pkp->dtpk_pmatch = dtrace_probekey_func(pdp->dtpd_provider);
6061 
6062 	pkp->dtpk_mod = pdp->dtpd_mod;
6063 	pkp->dtpk_mmatch = dtrace_probekey_func(pdp->dtpd_mod);
6064 
6065 	pkp->dtpk_func = pdp->dtpd_func;
6066 	pkp->dtpk_fmatch = dtrace_probekey_func(pdp->dtpd_func);
6067 
6068 	pkp->dtpk_name = pdp->dtpd_name;
6069 	pkp->dtpk_nmatch = dtrace_probekey_func(pdp->dtpd_name);
6070 
6071 	pkp->dtpk_id = pdp->dtpd_id;
6072 
6073 	if (pkp->dtpk_id == DTRACE_IDNONE &&
6074 	    pkp->dtpk_pmatch == &dtrace_match_nul &&
6075 	    pkp->dtpk_mmatch == &dtrace_match_nul &&
6076 	    pkp->dtpk_fmatch == &dtrace_match_nul &&
6077 	    pkp->dtpk_nmatch == &dtrace_match_nul)
6078 		pkp->dtpk_fmatch = &dtrace_match_nonzero;
6079 }
6080 
6081 /*
6082  * DTrace Provider-to-Framework API Functions
6083  *
6084  * These functions implement much of the Provider-to-Framework API, as
6085  * described in <sys/dtrace.h>.  The parts of the API not in this section are
6086  * the functions in the API for probe management (found below), and
6087  * dtrace_probe() itself (found above).
6088  */
6089 
6090 /*
6091  * Register the calling provider with the DTrace framework.  This should
6092  * generally be called by DTrace providers in their attach(9E) entry point.
6093  */
6094 int
6095 dtrace_register(const char *name, const dtrace_pattr_t *pap, uint32_t priv,
6096     cred_t *cr, const dtrace_pops_t *pops, void *arg, dtrace_provider_id_t *idp)
6097 {
6098 	dtrace_provider_t *provider;
6099 
6100 	if (name == NULL || pap == NULL || pops == NULL || idp == NULL) {
6101 		cmn_err(CE_WARN, "failed to register provider '%s': invalid "
6102 		    "arguments", name ? name : "<NULL>");
6103 		return (EINVAL);
6104 	}
6105 
6106 	if (name[0] == '\0' || dtrace_badname(name)) {
6107 		cmn_err(CE_WARN, "failed to register provider '%s': invalid "
6108 		    "provider name", name);
6109 		return (EINVAL);
6110 	}
6111 
6112 	if ((pops->dtps_provide == NULL && pops->dtps_provide_module == NULL) ||
6113 	    pops->dtps_enable == NULL || pops->dtps_disable == NULL ||
6114 	    pops->dtps_destroy == NULL ||
6115 	    ((pops->dtps_resume == NULL) != (pops->dtps_suspend == NULL))) {
6116 		cmn_err(CE_WARN, "failed to register provider '%s': invalid "
6117 		    "provider ops", name);
6118 		return (EINVAL);
6119 	}
6120 
6121 	if (dtrace_badattr(&pap->dtpa_provider) ||
6122 	    dtrace_badattr(&pap->dtpa_mod) ||
6123 	    dtrace_badattr(&pap->dtpa_func) ||
6124 	    dtrace_badattr(&pap->dtpa_name) ||
6125 	    dtrace_badattr(&pap->dtpa_args)) {
6126 		cmn_err(CE_WARN, "failed to register provider '%s': invalid "
6127 		    "provider attributes", name);
6128 		return (EINVAL);
6129 	}
6130 
6131 	if (priv & ~DTRACE_PRIV_ALL) {
6132 		cmn_err(CE_WARN, "failed to register provider '%s': invalid "
6133 		    "privilege attributes", name);
6134 		return (EINVAL);
6135 	}
6136 
6137 	if ((priv & DTRACE_PRIV_KERNEL) &&
6138 	    (priv & (DTRACE_PRIV_USER | DTRACE_PRIV_OWNER)) &&
6139 	    pops->dtps_usermode == NULL) {
6140 		cmn_err(CE_WARN, "failed to register provider '%s': need "
6141 		    "dtps_usermode() op for given privilege attributes", name);
6142 		return (EINVAL);
6143 	}
6144 
6145 	provider = kmem_zalloc(sizeof (dtrace_provider_t), KM_SLEEP);
6146 	provider->dtpv_name = kmem_alloc(strlen(name) + 1, KM_SLEEP);
6147 	(void) strcpy(provider->dtpv_name, name);
6148 
6149 	provider->dtpv_attr = *pap;
6150 	provider->dtpv_priv.dtpp_flags = priv;
6151 	if (cr != NULL) {
6152 		provider->dtpv_priv.dtpp_uid = crgetuid(cr);
6153 		provider->dtpv_priv.dtpp_zoneid = crgetzoneid(cr);
6154 	}
6155 	provider->dtpv_pops = *pops;
6156 
6157 	if (pops->dtps_provide == NULL) {
6158 		ASSERT(pops->dtps_provide_module != NULL);
6159 		provider->dtpv_pops.dtps_provide =
6160 		    (void (*)(void *, const dtrace_probedesc_t *))dtrace_nullop;
6161 	}
6162 
6163 	if (pops->dtps_provide_module == NULL) {
6164 		ASSERT(pops->dtps_provide != NULL);
6165 		provider->dtpv_pops.dtps_provide_module =
6166 		    (void (*)(void *, struct modctl *))dtrace_nullop;
6167 	}
6168 
6169 	if (pops->dtps_suspend == NULL) {
6170 		ASSERT(pops->dtps_resume == NULL);
6171 		provider->dtpv_pops.dtps_suspend =
6172 		    (void (*)(void *, dtrace_id_t, void *))dtrace_nullop;
6173 		provider->dtpv_pops.dtps_resume =
6174 		    (void (*)(void *, dtrace_id_t, void *))dtrace_nullop;
6175 	}
6176 
6177 	provider->dtpv_arg = arg;
6178 	*idp = (dtrace_provider_id_t)provider;
6179 
6180 	if (pops == &dtrace_provider_ops) {
6181 		ASSERT(MUTEX_HELD(&dtrace_provider_lock));
6182 		ASSERT(MUTEX_HELD(&dtrace_lock));
6183 		ASSERT(dtrace_anon.dta_enabling == NULL);
6184 
6185 		/*
6186 		 * We make sure that the DTrace provider is at the head of
6187 		 * the provider chain.
6188 		 */
6189 		provider->dtpv_next = dtrace_provider;
6190 		dtrace_provider = provider;
6191 		return (0);
6192 	}
6193 
6194 	mutex_enter(&dtrace_provider_lock);
6195 	mutex_enter(&dtrace_lock);
6196 
6197 	/*
6198 	 * If there is at least one provider registered, we'll add this
6199 	 * provider after the first provider.
6200 	 */
6201 	if (dtrace_provider != NULL) {
6202 		provider->dtpv_next = dtrace_provider->dtpv_next;
6203 		dtrace_provider->dtpv_next = provider;
6204 	} else {
6205 		dtrace_provider = provider;
6206 	}
6207 
6208 	if (dtrace_retained != NULL) {
6209 		dtrace_enabling_provide(provider);
6210 
6211 		/*
6212 		 * Now we need to call dtrace_enabling_matchall() -- which
6213 		 * will acquire cpu_lock and dtrace_lock.  We therefore need
6214 		 * to drop all of our locks before calling into it...
6215 		 */
6216 		mutex_exit(&dtrace_lock);
6217 		mutex_exit(&dtrace_provider_lock);
6218 		dtrace_enabling_matchall();
6219 
6220 		return (0);
6221 	}
6222 
6223 	mutex_exit(&dtrace_lock);
6224 	mutex_exit(&dtrace_provider_lock);
6225 
6226 	return (0);
6227 }
6228 
6229 /*
6230  * Unregister the specified provider from the DTrace framework.  This should
6231  * generally be called by DTrace providers in their detach(9E) entry point.
6232  */
6233 int
6234 dtrace_unregister(dtrace_provider_id_t id)
6235 {
6236 	dtrace_provider_t *old = (dtrace_provider_t *)id;
6237 	dtrace_provider_t *prev = NULL;
6238 	int i, self = 0;
6239 	dtrace_probe_t *probe, *first = NULL;
6240 
6241 	if (old->dtpv_pops.dtps_enable ==
6242 	    (void (*)(void *, dtrace_id_t, void *))dtrace_nullop) {
6243 		/*
6244 		 * If DTrace itself is the provider, we're called with locks
6245 		 * already held.
6246 		 */
6247 		ASSERT(old == dtrace_provider);
6248 		ASSERT(dtrace_devi != NULL);
6249 		ASSERT(MUTEX_HELD(&dtrace_provider_lock));
6250 		ASSERT(MUTEX_HELD(&dtrace_lock));
6251 		self = 1;
6252 
6253 		if (dtrace_provider->dtpv_next != NULL) {
6254 			/*
6255 			 * There's another provider here; return failure.
6256 			 */
6257 			return (EBUSY);
6258 		}
6259 	} else {
6260 		mutex_enter(&dtrace_provider_lock);
6261 		mutex_enter(&mod_lock);
6262 		mutex_enter(&dtrace_lock);
6263 	}
6264 
6265 	/*
6266 	 * If anyone has /dev/dtrace open, or if there are anonymous enabled
6267 	 * probes, we refuse to let providers slither away, unless this
6268 	 * provider has already been explicitly invalidated.
6269 	 */
6270 	if (!old->dtpv_defunct &&
6271 	    (dtrace_opens || (dtrace_anon.dta_state != NULL &&
6272 	    dtrace_anon.dta_state->dts_necbs > 0))) {
6273 		if (!self) {
6274 			mutex_exit(&dtrace_lock);
6275 			mutex_exit(&mod_lock);
6276 			mutex_exit(&dtrace_provider_lock);
6277 		}
6278 		return (EBUSY);
6279 	}
6280 
6281 	/*
6282 	 * Attempt to destroy the probes associated with this provider.
6283 	 */
6284 	for (i = 0; i < dtrace_nprobes; i++) {
6285 		if ((probe = dtrace_probes[i]) == NULL)
6286 			continue;
6287 
6288 		if (probe->dtpr_provider != old)
6289 			continue;
6290 
6291 		if (probe->dtpr_ecb == NULL)
6292 			continue;
6293 
6294 		/*
6295 		 * We have at least one ECB; we can't remove this provider.
6296 		 */
6297 		if (!self) {
6298 			mutex_exit(&dtrace_lock);
6299 			mutex_exit(&mod_lock);
6300 			mutex_exit(&dtrace_provider_lock);
6301 		}
6302 		return (EBUSY);
6303 	}
6304 
6305 	/*
6306 	 * All of the probes for this provider are disabled; we can safely
6307 	 * remove all of them from their hash chains and from the probe array.
6308 	 */
6309 	for (i = 0; i < dtrace_nprobes; i++) {
6310 		if ((probe = dtrace_probes[i]) == NULL)
6311 			continue;
6312 
6313 		if (probe->dtpr_provider != old)
6314 			continue;
6315 
6316 		dtrace_probes[i] = NULL;
6317 
6318 		dtrace_hash_remove(dtrace_bymod, probe);
6319 		dtrace_hash_remove(dtrace_byfunc, probe);
6320 		dtrace_hash_remove(dtrace_byname, probe);
6321 
6322 		if (first == NULL) {
6323 			first = probe;
6324 			probe->dtpr_nextmod = NULL;
6325 		} else {
6326 			probe->dtpr_nextmod = first;
6327 			first = probe;
6328 		}
6329 	}
6330 
6331 	/*
6332 	 * The provider's probes have been removed from the hash chains and
6333 	 * from the probe array.  Now issue a dtrace_sync() to be sure that
6334 	 * everyone has cleared out from any probe array processing.
6335 	 */
6336 	dtrace_sync();
6337 
6338 	for (probe = first; probe != NULL; probe = first) {
6339 		first = probe->dtpr_nextmod;
6340 
6341 		old->dtpv_pops.dtps_destroy(old->dtpv_arg, probe->dtpr_id,
6342 		    probe->dtpr_arg);
6343 		kmem_free(probe->dtpr_mod, strlen(probe->dtpr_mod) + 1);
6344 		kmem_free(probe->dtpr_func, strlen(probe->dtpr_func) + 1);
6345 		kmem_free(probe->dtpr_name, strlen(probe->dtpr_name) + 1);
6346 		vmem_free(dtrace_arena, (void *)(uintptr_t)(probe->dtpr_id), 1);
6347 		kmem_free(probe, sizeof (dtrace_probe_t));
6348 	}
6349 
6350 	if ((prev = dtrace_provider) == old) {
6351 		ASSERT(self || dtrace_devi == NULL);
6352 		ASSERT(old->dtpv_next == NULL || dtrace_devi == NULL);
6353 		dtrace_provider = old->dtpv_next;
6354 	} else {
6355 		while (prev != NULL && prev->dtpv_next != old)
6356 			prev = prev->dtpv_next;
6357 
6358 		if (prev == NULL) {
6359 			panic("attempt to unregister non-existent "
6360 			    "dtrace provider %p\n", (void *)id);
6361 		}
6362 
6363 		prev->dtpv_next = old->dtpv_next;
6364 	}
6365 
6366 	if (!self) {
6367 		mutex_exit(&dtrace_lock);
6368 		mutex_exit(&mod_lock);
6369 		mutex_exit(&dtrace_provider_lock);
6370 	}
6371 
6372 	kmem_free(old->dtpv_name, strlen(old->dtpv_name) + 1);
6373 	kmem_free(old, sizeof (dtrace_provider_t));
6374 
6375 	return (0);
6376 }
6377 
6378 /*
6379  * Invalidate the specified provider.  All subsequent probe lookups for the
6380  * specified provider will fail, but its probes will not be removed.
6381  */
6382 void
6383 dtrace_invalidate(dtrace_provider_id_t id)
6384 {
6385 	dtrace_provider_t *pvp = (dtrace_provider_t *)id;
6386 
6387 	ASSERT(pvp->dtpv_pops.dtps_enable !=
6388 	    (void (*)(void *, dtrace_id_t, void *))dtrace_nullop);
6389 
6390 	mutex_enter(&dtrace_provider_lock);
6391 	mutex_enter(&dtrace_lock);
6392 
6393 	pvp->dtpv_defunct = 1;
6394 
6395 	mutex_exit(&dtrace_lock);
6396 	mutex_exit(&dtrace_provider_lock);
6397 }
6398 
6399 /*
6400  * Indicate whether or not DTrace has attached.
6401  */
6402 int
6403 dtrace_attached(void)
6404 {
6405 	/*
6406 	 * dtrace_provider will be non-NULL iff the DTrace driver has
6407 	 * attached.  (It's non-NULL because DTrace is always itself a
6408 	 * provider.)
6409 	 */
6410 	return (dtrace_provider != NULL);
6411 }
6412 
6413 /*
6414  * Remove all the unenabled probes for the given provider.  This function is
6415  * not unlike dtrace_unregister(), except that it doesn't remove the provider
6416  * -- just as many of its associated probes as it can.
6417  */
6418 int
6419 dtrace_condense(dtrace_provider_id_t id)
6420 {
6421 	dtrace_provider_t *prov = (dtrace_provider_t *)id;
6422 	int i;
6423 	dtrace_probe_t *probe;
6424 
6425 	/*
6426 	 * Make sure this isn't the dtrace provider itself.
6427 	 */
6428 	ASSERT(prov->dtpv_pops.dtps_enable !=
6429 	    (void (*)(void *, dtrace_id_t, void *))dtrace_nullop);
6430 
6431 	mutex_enter(&dtrace_provider_lock);
6432 	mutex_enter(&dtrace_lock);
6433 
6434 	/*
6435 	 * Attempt to destroy the probes associated with this provider.
6436 	 */
6437 	for (i = 0; i < dtrace_nprobes; i++) {
6438 		if ((probe = dtrace_probes[i]) == NULL)
6439 			continue;
6440 
6441 		if (probe->dtpr_provider != prov)
6442 			continue;
6443 
6444 		if (probe->dtpr_ecb != NULL)
6445 			continue;
6446 
6447 		dtrace_probes[i] = NULL;
6448 
6449 		dtrace_hash_remove(dtrace_bymod, probe);
6450 		dtrace_hash_remove(dtrace_byfunc, probe);
6451 		dtrace_hash_remove(dtrace_byname, probe);
6452 
6453 		prov->dtpv_pops.dtps_destroy(prov->dtpv_arg, i + 1,
6454 		    probe->dtpr_arg);
6455 		kmem_free(probe->dtpr_mod, strlen(probe->dtpr_mod) + 1);
6456 		kmem_free(probe->dtpr_func, strlen(probe->dtpr_func) + 1);
6457 		kmem_free(probe->dtpr_name, strlen(probe->dtpr_name) + 1);
6458 		kmem_free(probe, sizeof (dtrace_probe_t));
6459 		vmem_free(dtrace_arena, (void *)((uintptr_t)i + 1), 1);
6460 	}
6461 
6462 	mutex_exit(&dtrace_lock);
6463 	mutex_exit(&dtrace_provider_lock);
6464 
6465 	return (0);
6466 }
6467 
6468 /*
6469  * DTrace Probe Management Functions
6470  *
6471  * The functions in this section perform the DTrace probe management,
6472  * including functions to create probes, look-up probes, and call into the
6473  * providers to request that probes be provided.  Some of these functions are
6474  * in the Provider-to-Framework API; these functions can be identified by the
6475  * fact that they are not declared "static".
6476  */
6477 
6478 /*
6479  * Create a probe with the specified module name, function name, and name.
6480  */
6481 dtrace_id_t
6482 dtrace_probe_create(dtrace_provider_id_t prov, const char *mod,
6483     const char *func, const char *name, int aframes, void *arg)
6484 {
6485 	dtrace_probe_t *probe, **probes;
6486 	dtrace_provider_t *provider = (dtrace_provider_t *)prov;
6487 	dtrace_id_t id;
6488 
6489 	if (provider == dtrace_provider) {
6490 		ASSERT(MUTEX_HELD(&dtrace_lock));
6491 	} else {
6492 		mutex_enter(&dtrace_lock);
6493 	}
6494 
6495 	id = (dtrace_id_t)(uintptr_t)vmem_alloc(dtrace_arena, 1,
6496 	    VM_BESTFIT | VM_SLEEP);
6497 	probe = kmem_zalloc(sizeof (dtrace_probe_t), KM_SLEEP);
6498 
6499 	probe->dtpr_id = id;
6500 	probe->dtpr_gen = dtrace_probegen++;
6501 	probe->dtpr_mod = dtrace_strdup(mod);
6502 	probe->dtpr_func = dtrace_strdup(func);
6503 	probe->dtpr_name = dtrace_strdup(name);
6504 	probe->dtpr_arg = arg;
6505 	probe->dtpr_aframes = aframes;
6506 	probe->dtpr_provider = provider;
6507 
6508 	dtrace_hash_add(dtrace_bymod, probe);
6509 	dtrace_hash_add(dtrace_byfunc, probe);
6510 	dtrace_hash_add(dtrace_byname, probe);
6511 
6512 	if (id - 1 >= dtrace_nprobes) {
6513 		size_t osize = dtrace_nprobes * sizeof (dtrace_probe_t *);
6514 		size_t nsize = osize << 1;
6515 
6516 		if (nsize == 0) {
6517 			ASSERT(osize == 0);
6518 			ASSERT(dtrace_probes == NULL);
6519 			nsize = sizeof (dtrace_probe_t *);
6520 		}
6521 
6522 		probes = kmem_zalloc(nsize, KM_SLEEP);
6523 
6524 		if (dtrace_probes == NULL) {
6525 			ASSERT(osize == 0);
6526 			dtrace_probes = probes;
6527 			dtrace_nprobes = 1;
6528 		} else {
6529 			dtrace_probe_t **oprobes = dtrace_probes;
6530 
6531 			bcopy(oprobes, probes, osize);
6532 			dtrace_membar_producer();
6533 			dtrace_probes = probes;
6534 
6535 			dtrace_sync();
6536 
6537 			/*
6538 			 * All CPUs are now seeing the new probes array; we can
6539 			 * safely free the old array.
6540 			 */
6541 			kmem_free(oprobes, osize);
6542 			dtrace_nprobes <<= 1;
6543 		}
6544 
6545 		ASSERT(id - 1 < dtrace_nprobes);
6546 	}
6547 
6548 	ASSERT(dtrace_probes[id - 1] == NULL);
6549 	dtrace_probes[id - 1] = probe;
6550 
6551 	if (provider != dtrace_provider)
6552 		mutex_exit(&dtrace_lock);
6553 
6554 	return (id);
6555 }
6556 
6557 static dtrace_probe_t *
6558 dtrace_probe_lookup_id(dtrace_id_t id)
6559 {
6560 	ASSERT(MUTEX_HELD(&dtrace_lock));
6561 
6562 	if (id == 0 || id > dtrace_nprobes)
6563 		return (NULL);
6564 
6565 	return (dtrace_probes[id - 1]);
6566 }
6567 
6568 static int
6569 dtrace_probe_lookup_match(dtrace_probe_t *probe, void *arg)
6570 {
6571 	*((dtrace_id_t *)arg) = probe->dtpr_id;
6572 
6573 	return (DTRACE_MATCH_DONE);
6574 }
6575 
6576 /*
6577  * Look up a probe based on provider and one or more of module name, function
6578  * name and probe name.
6579  */
6580 dtrace_id_t
6581 dtrace_probe_lookup(dtrace_provider_id_t prid, const char *mod,
6582     const char *func, const char *name)
6583 {
6584 	dtrace_probekey_t pkey;
6585 	dtrace_id_t id;
6586 	int match;
6587 
6588 	pkey.dtpk_prov = ((dtrace_provider_t *)prid)->dtpv_name;
6589 	pkey.dtpk_pmatch = &dtrace_match_string;
6590 	pkey.dtpk_mod = mod;
6591 	pkey.dtpk_mmatch = mod ? &dtrace_match_string : &dtrace_match_nul;
6592 	pkey.dtpk_func = func;
6593 	pkey.dtpk_fmatch = func ? &dtrace_match_string : &dtrace_match_nul;
6594 	pkey.dtpk_name = name;
6595 	pkey.dtpk_nmatch = name ? &dtrace_match_string : &dtrace_match_nul;
6596 	pkey.dtpk_id = DTRACE_IDNONE;
6597 
6598 	mutex_enter(&dtrace_lock);
6599 	match = dtrace_match(&pkey, DTRACE_PRIV_ALL, 0, 0,
6600 	    dtrace_probe_lookup_match, &id);
6601 	mutex_exit(&dtrace_lock);
6602 
6603 	ASSERT(match == 1 || match == 0);
6604 	return (match ? id : 0);
6605 }
6606 
6607 /*
6608  * Returns the probe argument associated with the specified probe.
6609  */
6610 void *
6611 dtrace_probe_arg(dtrace_provider_id_t id, dtrace_id_t pid)
6612 {
6613 	dtrace_probe_t *probe;
6614 	void *rval = NULL;
6615 
6616 	mutex_enter(&dtrace_lock);
6617 
6618 	if ((probe = dtrace_probe_lookup_id(pid)) != NULL &&
6619 	    probe->dtpr_provider == (dtrace_provider_t *)id)
6620 		rval = probe->dtpr_arg;
6621 
6622 	mutex_exit(&dtrace_lock);
6623 
6624 	return (rval);
6625 }
6626 
6627 /*
6628  * Copy a probe into a probe description.
6629  */
6630 static void
6631 dtrace_probe_description(const dtrace_probe_t *prp, dtrace_probedesc_t *pdp)
6632 {
6633 	bzero(pdp, sizeof (dtrace_probedesc_t));
6634 	pdp->dtpd_id = prp->dtpr_id;
6635 
6636 	(void) strncpy(pdp->dtpd_provider,
6637 	    prp->dtpr_provider->dtpv_name, DTRACE_PROVNAMELEN - 1);
6638 
6639 	(void) strncpy(pdp->dtpd_mod, prp->dtpr_mod, DTRACE_MODNAMELEN - 1);
6640 	(void) strncpy(pdp->dtpd_func, prp->dtpr_func, DTRACE_FUNCNAMELEN - 1);
6641 	(void) strncpy(pdp->dtpd_name, prp->dtpr_name, DTRACE_NAMELEN - 1);
6642 }
6643 
6644 /*
6645  * Called to indicate that a probe -- or probes -- should be provided by a
6646  * specfied provider.  If the specified description is NULL, the provider will
6647  * be told to provide all of its probes.  (This is done whenever a new
6648  * consumer comes along, or whenever a retained enabling is to be matched.) If
6649  * the specified description is non-NULL, the provider is given the
6650  * opportunity to dynamically provide the specified probe, allowing providers
6651  * to support the creation of probes on-the-fly.  (So-called _autocreated_
6652  * probes.)  If the provider is NULL, the operations will be applied to all
6653  * providers; if the provider is non-NULL the operations will only be applied
6654  * to the specified provider.  The dtrace_provider_lock must be held, and the
6655  * dtrace_lock must _not_ be held -- the provider's dtps_provide() operation
6656  * will need to grab the dtrace_lock when it reenters the framework through
6657  * dtrace_probe_lookup(), dtrace_probe_create(), etc.
6658  */
6659 static void
6660 dtrace_probe_provide(dtrace_probedesc_t *desc, dtrace_provider_t *prv)
6661 {
6662 	struct modctl *ctl;
6663 	int all = 0;
6664 
6665 	ASSERT(MUTEX_HELD(&dtrace_provider_lock));
6666 
6667 	if (prv == NULL) {
6668 		all = 1;
6669 		prv = dtrace_provider;
6670 	}
6671 
6672 	do {
6673 		/*
6674 		 * First, call the blanket provide operation.
6675 		 */
6676 		prv->dtpv_pops.dtps_provide(prv->dtpv_arg, desc);
6677 
6678 		/*
6679 		 * Now call the per-module provide operation.  We will grab
6680 		 * mod_lock to prevent the list from being modified.  Note
6681 		 * that this also prevents the mod_busy bits from changing.
6682 		 * (mod_busy can only be changed with mod_lock held.)
6683 		 */
6684 		mutex_enter(&mod_lock);
6685 
6686 		ctl = &modules;
6687 		do {
6688 			if (ctl->mod_busy || ctl->mod_mp == NULL)
6689 				continue;
6690 
6691 			prv->dtpv_pops.dtps_provide_module(prv->dtpv_arg, ctl);
6692 
6693 		} while ((ctl = ctl->mod_next) != &modules);
6694 
6695 		mutex_exit(&mod_lock);
6696 	} while (all && (prv = prv->dtpv_next) != NULL);
6697 }
6698 
6699 /*
6700  * Iterate over each probe, and call the Framework-to-Provider API function
6701  * denoted by offs.
6702  */
6703 static void
6704 dtrace_probe_foreach(uintptr_t offs)
6705 {
6706 	dtrace_provider_t *prov;
6707 	void (*func)(void *, dtrace_id_t, void *);
6708 	dtrace_probe_t *probe;
6709 	dtrace_icookie_t cookie;
6710 	int i;
6711 
6712 	/*
6713 	 * We disable interrupts to walk through the probe array.  This is
6714 	 * safe -- the dtrace_sync() in dtrace_unregister() assures that we
6715 	 * won't see stale data.
6716 	 */
6717 	cookie = dtrace_interrupt_disable();
6718 
6719 	for (i = 0; i < dtrace_nprobes; i++) {
6720 		if ((probe = dtrace_probes[i]) == NULL)
6721 			continue;
6722 
6723 		if (probe->dtpr_ecb == NULL) {
6724 			/*
6725 			 * This probe isn't enabled -- don't call the function.
6726 			 */
6727 			continue;
6728 		}
6729 
6730 		prov = probe->dtpr_provider;
6731 		func = *((void(**)(void *, dtrace_id_t, void *))
6732 		    ((uintptr_t)&prov->dtpv_pops + offs));
6733 
6734 		func(prov->dtpv_arg, i + 1, probe->dtpr_arg);
6735 	}
6736 
6737 	dtrace_interrupt_enable(cookie);
6738 }
6739 
6740 static int
6741 dtrace_probe_enable(const dtrace_probedesc_t *desc, dtrace_enabling_t *enab)
6742 {
6743 	dtrace_probekey_t pkey;
6744 	uint32_t priv;
6745 	uid_t uid;
6746 	zoneid_t zoneid;
6747 
6748 	ASSERT(MUTEX_HELD(&dtrace_lock));
6749 	dtrace_ecb_create_cache = NULL;
6750 
6751 	if (desc == NULL) {
6752 		/*
6753 		 * If we're passed a NULL description, we're being asked to
6754 		 * create an ECB with a NULL probe.
6755 		 */
6756 		(void) dtrace_ecb_create_enable(NULL, enab);
6757 		return (0);
6758 	}
6759 
6760 	dtrace_probekey(desc, &pkey);
6761 	dtrace_cred2priv(enab->dten_vstate->dtvs_state->dts_cred.dcr_cred,
6762 	    &priv, &uid, &zoneid);
6763 
6764 	return (dtrace_match(&pkey, priv, uid, zoneid, dtrace_ecb_create_enable,
6765 	    enab));
6766 }
6767 
6768 /*
6769  * DTrace Helper Provider Functions
6770  */
6771 static void
6772 dtrace_dofattr2attr(dtrace_attribute_t *attr, const dof_attr_t dofattr)
6773 {
6774 	attr->dtat_name = DOF_ATTR_NAME(dofattr);
6775 	attr->dtat_data = DOF_ATTR_DATA(dofattr);
6776 	attr->dtat_class = DOF_ATTR_CLASS(dofattr);
6777 }
6778 
6779 static void
6780 dtrace_dofprov2hprov(dtrace_helper_provdesc_t *hprov,
6781     const dof_provider_t *dofprov, char *strtab)
6782 {
6783 	hprov->dthpv_provname = strtab + dofprov->dofpv_name;
6784 	dtrace_dofattr2attr(&hprov->dthpv_pattr.dtpa_provider,
6785 	    dofprov->dofpv_provattr);
6786 	dtrace_dofattr2attr(&hprov->dthpv_pattr.dtpa_mod,
6787 	    dofprov->dofpv_modattr);
6788 	dtrace_dofattr2attr(&hprov->dthpv_pattr.dtpa_func,
6789 	    dofprov->dofpv_funcattr);
6790 	dtrace_dofattr2attr(&hprov->dthpv_pattr.dtpa_name,
6791 	    dofprov->dofpv_nameattr);
6792 	dtrace_dofattr2attr(&hprov->dthpv_pattr.dtpa_args,
6793 	    dofprov->dofpv_argsattr);
6794 }
6795 
6796 static void
6797 dtrace_helper_provide_one(dof_helper_t *dhp, dof_sec_t *sec, pid_t pid)
6798 {
6799 	uintptr_t daddr = (uintptr_t)dhp->dofhp_dof;
6800 	dof_hdr_t *dof = (dof_hdr_t *)daddr;
6801 	dof_sec_t *str_sec, *prb_sec, *arg_sec, *off_sec, *enoff_sec;
6802 	dof_provider_t *provider;
6803 	dof_probe_t *probe;
6804 	uint32_t *off, *enoff;
6805 	uint8_t *arg;
6806 	char *strtab;
6807 	uint_t i, nprobes;
6808 	dtrace_helper_provdesc_t dhpv;
6809 	dtrace_helper_probedesc_t dhpb;
6810 	dtrace_meta_t *meta = dtrace_meta_pid;
6811 	dtrace_mops_t *mops = &meta->dtm_mops;
6812 	void *parg;
6813 
6814 	provider = (dof_provider_t *)(uintptr_t)(daddr + sec->dofs_offset);
6815 	str_sec = (dof_sec_t *)(uintptr_t)(daddr + dof->dofh_secoff +
6816 	    provider->dofpv_strtab * dof->dofh_secsize);
6817 	prb_sec = (dof_sec_t *)(uintptr_t)(daddr + dof->dofh_secoff +
6818 	    provider->dofpv_probes * dof->dofh_secsize);
6819 	arg_sec = (dof_sec_t *)(uintptr_t)(daddr + dof->dofh_secoff +
6820 	    provider->dofpv_prargs * dof->dofh_secsize);
6821 	off_sec = (dof_sec_t *)(uintptr_t)(daddr + dof->dofh_secoff +
6822 	    provider->dofpv_proffs * dof->dofh_secsize);
6823 
6824 	strtab = (char *)(uintptr_t)(daddr + str_sec->dofs_offset);
6825 	off = (uint32_t *)(uintptr_t)(daddr + off_sec->dofs_offset);
6826 	arg = (uint8_t *)(uintptr_t)(daddr + arg_sec->dofs_offset);
6827 	enoff = NULL;
6828 
6829 	/*
6830 	 * See dtrace_helper_provider_validate().
6831 	 */
6832 	if (dof->dofh_ident[DOF_ID_VERSION] != DOF_VERSION_1 &&
6833 	    provider->dofpv_prenoffs != DOF_SECT_NONE) {
6834 		enoff_sec = (dof_sec_t *)(uintptr_t)(daddr + dof->dofh_secoff +
6835 		    provider->dofpv_prenoffs * dof->dofh_secsize);
6836 		enoff = (uint32_t *)(uintptr_t)(daddr + enoff_sec->dofs_offset);
6837 	}
6838 
6839 	nprobes = prb_sec->dofs_size / prb_sec->dofs_entsize;
6840 
6841 	/*
6842 	 * Create the provider.
6843 	 */
6844 	dtrace_dofprov2hprov(&dhpv, provider, strtab);
6845 
6846 	if ((parg = mops->dtms_provide_pid(meta->dtm_arg, &dhpv, pid)) == NULL)
6847 		return;
6848 
6849 	meta->dtm_count++;
6850 
6851 	/*
6852 	 * Create the probes.
6853 	 */
6854 	for (i = 0; i < nprobes; i++) {
6855 		probe = (dof_probe_t *)(uintptr_t)(daddr +
6856 		    prb_sec->dofs_offset + i * prb_sec->dofs_entsize);
6857 
6858 		dhpb.dthpb_mod = dhp->dofhp_mod;
6859 		dhpb.dthpb_func = strtab + probe->dofpr_func;
6860 		dhpb.dthpb_name = strtab + probe->dofpr_name;
6861 		dhpb.dthpb_base = probe->dofpr_addr;
6862 		dhpb.dthpb_offs = off + probe->dofpr_offidx;
6863 		dhpb.dthpb_noffs = probe->dofpr_noffs;
6864 		if (enoff != NULL) {
6865 			dhpb.dthpb_enoffs = enoff + probe->dofpr_enoffidx;
6866 			dhpb.dthpb_nenoffs = probe->dofpr_nenoffs;
6867 		} else {
6868 			dhpb.dthpb_enoffs = NULL;
6869 			dhpb.dthpb_nenoffs = 0;
6870 		}
6871 		dhpb.dthpb_args = arg + probe->dofpr_argidx;
6872 		dhpb.dthpb_nargc = probe->dofpr_nargc;
6873 		dhpb.dthpb_xargc = probe->dofpr_xargc;
6874 		dhpb.dthpb_ntypes = strtab + probe->dofpr_nargv;
6875 		dhpb.dthpb_xtypes = strtab + probe->dofpr_xargv;
6876 
6877 		mops->dtms_create_probe(meta->dtm_arg, parg, &dhpb);
6878 	}
6879 }
6880 
6881 static void
6882 dtrace_helper_provide(dof_helper_t *dhp, pid_t pid)
6883 {
6884 	uintptr_t daddr = (uintptr_t)dhp->dofhp_dof;
6885 	dof_hdr_t *dof = (dof_hdr_t *)daddr;
6886 	int i;
6887 
6888 	ASSERT(MUTEX_HELD(&dtrace_meta_lock));
6889 
6890 	for (i = 0; i < dof->dofh_secnum; i++) {
6891 		dof_sec_t *sec = (dof_sec_t *)(uintptr_t)(daddr +
6892 		    dof->dofh_secoff + i * dof->dofh_secsize);
6893 
6894 		if (sec->dofs_type != DOF_SECT_PROVIDER)
6895 			continue;
6896 
6897 		dtrace_helper_provide_one(dhp, sec, pid);
6898 	}
6899 
6900 	/*
6901 	 * We may have just created probes, so we must now rematch against
6902 	 * any retained enablings.  Note that this call will acquire both
6903 	 * cpu_lock and dtrace_lock; the fact that we are holding
6904 	 * dtrace_meta_lock now is what defines the ordering with respect to
6905 	 * these three locks.
6906 	 */
6907 	dtrace_enabling_matchall();
6908 }
6909 
6910 static void
6911 dtrace_helper_provider_remove_one(dof_helper_t *dhp, dof_sec_t *sec, pid_t pid)
6912 {
6913 	uintptr_t daddr = (uintptr_t)dhp->dofhp_dof;
6914 	dof_hdr_t *dof = (dof_hdr_t *)daddr;
6915 	dof_sec_t *str_sec;
6916 	dof_provider_t *provider;
6917 	char *strtab;
6918 	dtrace_helper_provdesc_t dhpv;
6919 	dtrace_meta_t *meta = dtrace_meta_pid;
6920 	dtrace_mops_t *mops = &meta->dtm_mops;
6921 
6922 	provider = (dof_provider_t *)(uintptr_t)(daddr + sec->dofs_offset);
6923 	str_sec = (dof_sec_t *)(uintptr_t)(daddr + dof->dofh_secoff +
6924 	    provider->dofpv_strtab * dof->dofh_secsize);
6925 
6926 	strtab = (char *)(uintptr_t)(daddr + str_sec->dofs_offset);
6927 
6928 	/*
6929 	 * Create the provider.
6930 	 */
6931 	dtrace_dofprov2hprov(&dhpv, provider, strtab);
6932 
6933 	mops->dtms_remove_pid(meta->dtm_arg, &dhpv, pid);
6934 
6935 	meta->dtm_count--;
6936 }
6937 
6938 static void
6939 dtrace_helper_provider_remove(dof_helper_t *dhp, pid_t pid)
6940 {
6941 	uintptr_t daddr = (uintptr_t)dhp->dofhp_dof;
6942 	dof_hdr_t *dof = (dof_hdr_t *)daddr;
6943 	int i;
6944 
6945 	ASSERT(MUTEX_HELD(&dtrace_meta_lock));
6946 
6947 	for (i = 0; i < dof->dofh_secnum; i++) {
6948 		dof_sec_t *sec = (dof_sec_t *)(uintptr_t)(daddr +
6949 		    dof->dofh_secoff + i * dof->dofh_secsize);
6950 
6951 		if (sec->dofs_type != DOF_SECT_PROVIDER)
6952 			continue;
6953 
6954 		dtrace_helper_provider_remove_one(dhp, sec, pid);
6955 	}
6956 }
6957 
6958 /*
6959  * DTrace Meta Provider-to-Framework API Functions
6960  *
6961  * These functions implement the Meta Provider-to-Framework API, as described
6962  * in <sys/dtrace.h>.
6963  */
6964 int
6965 dtrace_meta_register(const char *name, const dtrace_mops_t *mops, void *arg,
6966     dtrace_meta_provider_id_t *idp)
6967 {
6968 	dtrace_meta_t *meta;
6969 	dtrace_helpers_t *help, *next;
6970 	int i;
6971 
6972 	*idp = DTRACE_METAPROVNONE;
6973 
6974 	/*
6975 	 * We strictly don't need the name, but we hold onto it for
6976 	 * debuggability. All hail error queues!
6977 	 */
6978 	if (name == NULL) {
6979 		cmn_err(CE_WARN, "failed to register meta-provider: "
6980 		    "invalid name");
6981 		return (EINVAL);
6982 	}
6983 
6984 	if (mops == NULL ||
6985 	    mops->dtms_create_probe == NULL ||
6986 	    mops->dtms_provide_pid == NULL ||
6987 	    mops->dtms_remove_pid == NULL) {
6988 		cmn_err(CE_WARN, "failed to register meta-register %s: "
6989 		    "invalid ops", name);
6990 		return (EINVAL);
6991 	}
6992 
6993 	meta = kmem_zalloc(sizeof (dtrace_meta_t), KM_SLEEP);
6994 	meta->dtm_mops = *mops;
6995 	meta->dtm_name = kmem_alloc(strlen(name) + 1, KM_SLEEP);
6996 	(void) strcpy(meta->dtm_name, name);
6997 	meta->dtm_arg = arg;
6998 
6999 	mutex_enter(&dtrace_meta_lock);
7000 	mutex_enter(&dtrace_lock);
7001 
7002 	if (dtrace_meta_pid != NULL) {
7003 		mutex_exit(&dtrace_lock);
7004 		mutex_exit(&dtrace_meta_lock);
7005 		cmn_err(CE_WARN, "failed to register meta-register %s: "
7006 		    "user-land meta-provider exists", name);
7007 		kmem_free(meta->dtm_name, strlen(meta->dtm_name) + 1);
7008 		kmem_free(meta, sizeof (dtrace_meta_t));
7009 		return (EINVAL);
7010 	}
7011 
7012 	dtrace_meta_pid = meta;
7013 	*idp = (dtrace_meta_provider_id_t)meta;
7014 
7015 	/*
7016 	 * If there are providers and probes ready to go, pass them
7017 	 * off to the new meta provider now.
7018 	 */
7019 
7020 	help = dtrace_deferred_pid;
7021 	dtrace_deferred_pid = NULL;
7022 
7023 	mutex_exit(&dtrace_lock);
7024 
7025 	while (help != NULL) {
7026 		for (i = 0; i < help->dthps_nprovs; i++) {
7027 			dtrace_helper_provide(&help->dthps_provs[i]->dthp_prov,
7028 			    help->dthps_pid);
7029 		}
7030 
7031 		next = help->dthps_next;
7032 		help->dthps_next = NULL;
7033 		help->dthps_prev = NULL;
7034 		help->dthps_deferred = 0;
7035 		help = next;
7036 	}
7037 
7038 	mutex_exit(&dtrace_meta_lock);
7039 
7040 	return (0);
7041 }
7042 
7043 int
7044 dtrace_meta_unregister(dtrace_meta_provider_id_t id)
7045 {
7046 	dtrace_meta_t **pp, *old = (dtrace_meta_t *)id;
7047 
7048 	mutex_enter(&dtrace_meta_lock);
7049 	mutex_enter(&dtrace_lock);
7050 
7051 	if (old == dtrace_meta_pid) {
7052 		pp = &dtrace_meta_pid;
7053 	} else {
7054 		panic("attempt to unregister non-existent "
7055 		    "dtrace meta-provider %p\n", (void *)old);
7056 	}
7057 
7058 	if (old->dtm_count != 0) {
7059 		mutex_exit(&dtrace_lock);
7060 		mutex_exit(&dtrace_meta_lock);
7061 		return (EBUSY);
7062 	}
7063 
7064 	*pp = NULL;
7065 
7066 	mutex_exit(&dtrace_lock);
7067 	mutex_exit(&dtrace_meta_lock);
7068 
7069 	kmem_free(old->dtm_name, strlen(old->dtm_name) + 1);
7070 	kmem_free(old, sizeof (dtrace_meta_t));
7071 
7072 	return (0);
7073 }
7074 
7075 
7076 /*
7077  * DTrace DIF Object Functions
7078  */
7079 static int
7080 dtrace_difo_err(uint_t pc, const char *format, ...)
7081 {
7082 	if (dtrace_err_verbose) {
7083 		va_list alist;
7084 
7085 		(void) uprintf("dtrace DIF object error: [%u]: ", pc);
7086 		va_start(alist, format);
7087 		(void) vuprintf(format, alist);
7088 		va_end(alist);
7089 	}
7090 
7091 #ifdef DTRACE_ERRDEBUG
7092 	dtrace_errdebug(format);
7093 #endif
7094 	return (1);
7095 }
7096 
7097 /*
7098  * Validate a DTrace DIF object by checking the IR instructions.  The following
7099  * rules are currently enforced by dtrace_difo_validate():
7100  *
7101  * 1. Each instruction must have a valid opcode
7102  * 2. Each register, string, variable, or subroutine reference must be valid
7103  * 3. No instruction can modify register %r0 (must be zero)
7104  * 4. All instruction reserved bits must be set to zero
7105  * 5. The last instruction must be a "ret" instruction
7106  * 6. All branch targets must reference a valid instruction _after_ the branch
7107  */
7108 static int
7109 dtrace_difo_validate(dtrace_difo_t *dp, dtrace_vstate_t *vstate, uint_t nregs,
7110     cred_t *cr)
7111 {
7112 	int err = 0, i;
7113 	int (*efunc)(uint_t pc, const char *, ...) = dtrace_difo_err;
7114 	int kcheck;
7115 	uint_t pc;
7116 
7117 	kcheck = cr == NULL ||
7118 	    PRIV_POLICY_ONLY(cr, PRIV_DTRACE_KERNEL, B_FALSE) == 0;
7119 
7120 	dp->dtdo_destructive = 0;
7121 
7122 	for (pc = 0; pc < dp->dtdo_len && err == 0; pc++) {
7123 		dif_instr_t instr = dp->dtdo_buf[pc];
7124 
7125 		uint_t r1 = DIF_INSTR_R1(instr);
7126 		uint_t r2 = DIF_INSTR_R2(instr);
7127 		uint_t rd = DIF_INSTR_RD(instr);
7128 		uint_t rs = DIF_INSTR_RS(instr);
7129 		uint_t label = DIF_INSTR_LABEL(instr);
7130 		uint_t v = DIF_INSTR_VAR(instr);
7131 		uint_t subr = DIF_INSTR_SUBR(instr);
7132 		uint_t type = DIF_INSTR_TYPE(instr);
7133 		uint_t op = DIF_INSTR_OP(instr);
7134 
7135 		switch (op) {
7136 		case DIF_OP_OR:
7137 		case DIF_OP_XOR:
7138 		case DIF_OP_AND:
7139 		case DIF_OP_SLL:
7140 		case DIF_OP_SRL:
7141 		case DIF_OP_SRA:
7142 		case DIF_OP_SUB:
7143 		case DIF_OP_ADD:
7144 		case DIF_OP_MUL:
7145 		case DIF_OP_SDIV:
7146 		case DIF_OP_UDIV:
7147 		case DIF_OP_SREM:
7148 		case DIF_OP_UREM:
7149 		case DIF_OP_COPYS:
7150 			if (r1 >= nregs)
7151 				err += efunc(pc, "invalid register %u\n", r1);
7152 			if (r2 >= nregs)
7153 				err += efunc(pc, "invalid register %u\n", r2);
7154 			if (rd >= nregs)
7155 				err += efunc(pc, "invalid register %u\n", rd);
7156 			if (rd == 0)
7157 				err += efunc(pc, "cannot write to %r0\n");
7158 			break;
7159 		case DIF_OP_NOT:
7160 		case DIF_OP_MOV:
7161 		case DIF_OP_ALLOCS:
7162 			if (r1 >= nregs)
7163 				err += efunc(pc, "invalid register %u\n", r1);
7164 			if (r2 != 0)
7165 				err += efunc(pc, "non-zero reserved bits\n");
7166 			if (rd >= nregs)
7167 				err += efunc(pc, "invalid register %u\n", rd);
7168 			if (rd == 0)
7169 				err += efunc(pc, "cannot write to %r0\n");
7170 			break;
7171 		case DIF_OP_LDSB:
7172 		case DIF_OP_LDSH:
7173 		case DIF_OP_LDSW:
7174 		case DIF_OP_LDUB:
7175 		case DIF_OP_LDUH:
7176 		case DIF_OP_LDUW:
7177 		case DIF_OP_LDX:
7178 			if (r1 >= nregs)
7179 				err += efunc(pc, "invalid register %u\n", r1);
7180 			if (r2 != 0)
7181 				err += efunc(pc, "non-zero reserved bits\n");
7182 			if (rd >= nregs)
7183 				err += efunc(pc, "invalid register %u\n", rd);
7184 			if (rd == 0)
7185 				err += efunc(pc, "cannot write to %r0\n");
7186 			if (kcheck)
7187 				dp->dtdo_buf[pc] = DIF_INSTR_LOAD(op +
7188 				    DIF_OP_RLDSB - DIF_OP_LDSB, r1, rd);
7189 			break;
7190 		case DIF_OP_RLDSB:
7191 		case DIF_OP_RLDSH:
7192 		case DIF_OP_RLDSW:
7193 		case DIF_OP_RLDUB:
7194 		case DIF_OP_RLDUH:
7195 		case DIF_OP_RLDUW:
7196 		case DIF_OP_RLDX:
7197 			if (r1 >= nregs)
7198 				err += efunc(pc, "invalid register %u\n", r1);
7199 			if (r2 != 0)
7200 				err += efunc(pc, "non-zero reserved bits\n");
7201 			if (rd >= nregs)
7202 				err += efunc(pc, "invalid register %u\n", rd);
7203 			if (rd == 0)
7204 				err += efunc(pc, "cannot write to %r0\n");
7205 			break;
7206 		case DIF_OP_ULDSB:
7207 		case DIF_OP_ULDSH:
7208 		case DIF_OP_ULDSW:
7209 		case DIF_OP_ULDUB:
7210 		case DIF_OP_ULDUH:
7211 		case DIF_OP_ULDUW:
7212 		case DIF_OP_ULDX:
7213 			if (r1 >= nregs)
7214 				err += efunc(pc, "invalid register %u\n", r1);
7215 			if (r2 != 0)
7216 				err += efunc(pc, "non-zero reserved bits\n");
7217 			if (rd >= nregs)
7218 				err += efunc(pc, "invalid register %u\n", rd);
7219 			if (rd == 0)
7220 				err += efunc(pc, "cannot write to %r0\n");
7221 			break;
7222 		case DIF_OP_STB:
7223 		case DIF_OP_STH:
7224 		case DIF_OP_STW:
7225 		case DIF_OP_STX:
7226 			if (r1 >= nregs)
7227 				err += efunc(pc, "invalid register %u\n", r1);
7228 			if (r2 != 0)
7229 				err += efunc(pc, "non-zero reserved bits\n");
7230 			if (rd >= nregs)
7231 				err += efunc(pc, "invalid register %u\n", rd);
7232 			if (rd == 0)
7233 				err += efunc(pc, "cannot write to 0 address\n");
7234 			break;
7235 		case DIF_OP_CMP:
7236 		case DIF_OP_SCMP:
7237 			if (r1 >= nregs)
7238 				err += efunc(pc, "invalid register %u\n", r1);
7239 			if (r2 >= nregs)
7240 				err += efunc(pc, "invalid register %u\n", r2);
7241 			if (rd != 0)
7242 				err += efunc(pc, "non-zero reserved bits\n");
7243 			break;
7244 		case DIF_OP_TST:
7245 			if (r1 >= nregs)
7246 				err += efunc(pc, "invalid register %u\n", r1);
7247 			if (r2 != 0 || rd != 0)
7248 				err += efunc(pc, "non-zero reserved bits\n");
7249 			break;
7250 		case DIF_OP_BA:
7251 		case DIF_OP_BE:
7252 		case DIF_OP_BNE:
7253 		case DIF_OP_BG:
7254 		case DIF_OP_BGU:
7255 		case DIF_OP_BGE:
7256 		case DIF_OP_BGEU:
7257 		case DIF_OP_BL:
7258 		case DIF_OP_BLU:
7259 		case DIF_OP_BLE:
7260 		case DIF_OP_BLEU:
7261 			if (label >= dp->dtdo_len) {
7262 				err += efunc(pc, "invalid branch target %u\n",
7263 				    label);
7264 			}
7265 			if (label <= pc) {
7266 				err += efunc(pc, "backward branch to %u\n",
7267 				    label);
7268 			}
7269 			break;
7270 		case DIF_OP_RET:
7271 			if (r1 != 0 || r2 != 0)
7272 				err += efunc(pc, "non-zero reserved bits\n");
7273 			if (rd >= nregs)
7274 				err += efunc(pc, "invalid register %u\n", rd);
7275 			break;
7276 		case DIF_OP_NOP:
7277 		case DIF_OP_POPTS:
7278 		case DIF_OP_FLUSHTS:
7279 			if (r1 != 0 || r2 != 0 || rd != 0)
7280 				err += efunc(pc, "non-zero reserved bits\n");
7281 			break;
7282 		case DIF_OP_SETX:
7283 			if (DIF_INSTR_INTEGER(instr) >= dp->dtdo_intlen) {
7284 				err += efunc(pc, "invalid integer ref %u\n",
7285 				    DIF_INSTR_INTEGER(instr));
7286 			}
7287 			if (rd >= nregs)
7288 				err += efunc(pc, "invalid register %u\n", rd);
7289 			if (rd == 0)
7290 				err += efunc(pc, "cannot write to %r0\n");
7291 			break;
7292 		case DIF_OP_SETS:
7293 			if (DIF_INSTR_STRING(instr) >= dp->dtdo_strlen) {
7294 				err += efunc(pc, "invalid string ref %u\n",
7295 				    DIF_INSTR_STRING(instr));
7296 			}
7297 			if (rd >= nregs)
7298 				err += efunc(pc, "invalid register %u\n", rd);
7299 			if (rd == 0)
7300 				err += efunc(pc, "cannot write to %r0\n");
7301 			break;
7302 		case DIF_OP_LDGA:
7303 		case DIF_OP_LDTA:
7304 			if (r1 > DIF_VAR_ARRAY_MAX)
7305 				err += efunc(pc, "invalid array %u\n", r1);
7306 			if (r2 >= nregs)
7307 				err += efunc(pc, "invalid register %u\n", r2);
7308 			if (rd >= nregs)
7309 				err += efunc(pc, "invalid register %u\n", rd);
7310 			if (rd == 0)
7311 				err += efunc(pc, "cannot write to %r0\n");
7312 			break;
7313 		case DIF_OP_LDGS:
7314 		case DIF_OP_LDTS:
7315 		case DIF_OP_LDLS:
7316 		case DIF_OP_LDGAA:
7317 		case DIF_OP_LDTAA:
7318 			if (v < DIF_VAR_OTHER_MIN || v > DIF_VAR_OTHER_MAX)
7319 				err += efunc(pc, "invalid variable %u\n", v);
7320 			if (rd >= nregs)
7321 				err += efunc(pc, "invalid register %u\n", rd);
7322 			if (rd == 0)
7323 				err += efunc(pc, "cannot write to %r0\n");
7324 			break;
7325 		case DIF_OP_STGS:
7326 		case DIF_OP_STTS:
7327 		case DIF_OP_STLS:
7328 		case DIF_OP_STGAA:
7329 		case DIF_OP_STTAA:
7330 			if (v < DIF_VAR_OTHER_UBASE || v > DIF_VAR_OTHER_MAX)
7331 				err += efunc(pc, "invalid variable %u\n", v);
7332 			if (rs >= nregs)
7333 				err += efunc(pc, "invalid register %u\n", rd);
7334 			break;
7335 		case DIF_OP_CALL:
7336 			if (subr > DIF_SUBR_MAX)
7337 				err += efunc(pc, "invalid subr %u\n", subr);
7338 			if (rd >= nregs)
7339 				err += efunc(pc, "invalid register %u\n", rd);
7340 			if (rd == 0)
7341 				err += efunc(pc, "cannot write to %r0\n");
7342 
7343 			if (subr == DIF_SUBR_COPYOUT ||
7344 			    subr == DIF_SUBR_COPYOUTSTR) {
7345 				dp->dtdo_destructive = 1;
7346 			}
7347 			break;
7348 		case DIF_OP_PUSHTR:
7349 			if (type != DIF_TYPE_STRING && type != DIF_TYPE_CTF)
7350 				err += efunc(pc, "invalid ref type %u\n", type);
7351 			if (r2 >= nregs)
7352 				err += efunc(pc, "invalid register %u\n", r2);
7353 			if (rs >= nregs)
7354 				err += efunc(pc, "invalid register %u\n", rs);
7355 			break;
7356 		case DIF_OP_PUSHTV:
7357 			if (type != DIF_TYPE_CTF)
7358 				err += efunc(pc, "invalid val type %u\n", type);
7359 			if (r2 >= nregs)
7360 				err += efunc(pc, "invalid register %u\n", r2);
7361 			if (rs >= nregs)
7362 				err += efunc(pc, "invalid register %u\n", rs);
7363 			break;
7364 		default:
7365 			err += efunc(pc, "invalid opcode %u\n",
7366 			    DIF_INSTR_OP(instr));
7367 		}
7368 	}
7369 
7370 	if (dp->dtdo_len != 0 &&
7371 	    DIF_INSTR_OP(dp->dtdo_buf[dp->dtdo_len - 1]) != DIF_OP_RET) {
7372 		err += efunc(dp->dtdo_len - 1,
7373 		    "expected 'ret' as last DIF instruction\n");
7374 	}
7375 
7376 	if (!(dp->dtdo_rtype.dtdt_flags & DIF_TF_BYREF)) {
7377 		/*
7378 		 * If we're not returning by reference, the size must be either
7379 		 * 0 or the size of one of the base types.
7380 		 */
7381 		switch (dp->dtdo_rtype.dtdt_size) {
7382 		case 0:
7383 		case sizeof (uint8_t):
7384 		case sizeof (uint16_t):
7385 		case sizeof (uint32_t):
7386 		case sizeof (uint64_t):
7387 			break;
7388 
7389 		default:
7390 			err += efunc(dp->dtdo_len - 1, "bad return size");
7391 		}
7392 	}
7393 
7394 	for (i = 0; i < dp->dtdo_varlen && err == 0; i++) {
7395 		dtrace_difv_t *v = &dp->dtdo_vartab[i], *existing = NULL;
7396 		dtrace_diftype_t *vt, *et;
7397 		uint_t id, ndx;
7398 
7399 		if (v->dtdv_scope != DIFV_SCOPE_GLOBAL &&
7400 		    v->dtdv_scope != DIFV_SCOPE_THREAD &&
7401 		    v->dtdv_scope != DIFV_SCOPE_LOCAL) {
7402 			err += efunc(i, "unrecognized variable scope %d\n",
7403 			    v->dtdv_scope);
7404 			break;
7405 		}
7406 
7407 		if (v->dtdv_kind != DIFV_KIND_ARRAY &&
7408 		    v->dtdv_kind != DIFV_KIND_SCALAR) {
7409 			err += efunc(i, "unrecognized variable type %d\n",
7410 			    v->dtdv_kind);
7411 			break;
7412 		}
7413 
7414 		if ((id = v->dtdv_id) > DIF_VARIABLE_MAX) {
7415 			err += efunc(i, "%d exceeds variable id limit\n", id);
7416 			break;
7417 		}
7418 
7419 		if (id < DIF_VAR_OTHER_UBASE)
7420 			continue;
7421 
7422 		/*
7423 		 * For user-defined variables, we need to check that this
7424 		 * definition is identical to any previous definition that we
7425 		 * encountered.
7426 		 */
7427 		ndx = id - DIF_VAR_OTHER_UBASE;
7428 
7429 		switch (v->dtdv_scope) {
7430 		case DIFV_SCOPE_GLOBAL:
7431 			if (ndx < vstate->dtvs_nglobals) {
7432 				dtrace_statvar_t *svar;
7433 
7434 				if ((svar = vstate->dtvs_globals[ndx]) != NULL)
7435 					existing = &svar->dtsv_var;
7436 			}
7437 
7438 			break;
7439 
7440 		case DIFV_SCOPE_THREAD:
7441 			if (ndx < vstate->dtvs_ntlocals)
7442 				existing = &vstate->dtvs_tlocals[ndx];
7443 			break;
7444 
7445 		case DIFV_SCOPE_LOCAL:
7446 			if (ndx < vstate->dtvs_nlocals) {
7447 				dtrace_statvar_t *svar;
7448 
7449 				if ((svar = vstate->dtvs_locals[ndx]) != NULL)
7450 					existing = &svar->dtsv_var;
7451 			}
7452 
7453 			break;
7454 		}
7455 
7456 		vt = &v->dtdv_type;
7457 
7458 		if (vt->dtdt_flags & DIF_TF_BYREF) {
7459 			if (vt->dtdt_size == 0) {
7460 				err += efunc(i, "zero-sized variable\n");
7461 				break;
7462 			}
7463 
7464 			if (v->dtdv_scope == DIFV_SCOPE_GLOBAL &&
7465 			    vt->dtdt_size > dtrace_global_maxsize) {
7466 				err += efunc(i, "oversized by-ref global\n");
7467 				break;
7468 			}
7469 		}
7470 
7471 		if (existing == NULL || existing->dtdv_id == 0)
7472 			continue;
7473 
7474 		ASSERT(existing->dtdv_id == v->dtdv_id);
7475 		ASSERT(existing->dtdv_scope == v->dtdv_scope);
7476 
7477 		if (existing->dtdv_kind != v->dtdv_kind)
7478 			err += efunc(i, "%d changed variable kind\n", id);
7479 
7480 		et = &existing->dtdv_type;
7481 
7482 		if (vt->dtdt_flags != et->dtdt_flags) {
7483 			err += efunc(i, "%d changed variable type flags\n", id);
7484 			break;
7485 		}
7486 
7487 		if (vt->dtdt_size != 0 && vt->dtdt_size != et->dtdt_size) {
7488 			err += efunc(i, "%d changed variable type size\n", id);
7489 			break;
7490 		}
7491 	}
7492 
7493 	return (err);
7494 }
7495 
7496 /*
7497  * Validate a DTrace DIF object that it is to be used as a helper.  Helpers
7498  * are much more constrained than normal DIFOs.  Specifically, they may
7499  * not:
7500  *
7501  * 1. Make calls to subroutines other than copyin(), copyinstr() or
7502  *    miscellaneous string routines
7503  * 2. Access DTrace variables other than the args[] array, and the
7504  *    curthread, pid, ppid, tid, execname, zonename, uid and gid variables.
7505  * 3. Have thread-local variables.
7506  * 4. Have dynamic variables.
7507  */
7508 static int
7509 dtrace_difo_validate_helper(dtrace_difo_t *dp)
7510 {
7511 	int (*efunc)(uint_t pc, const char *, ...) = dtrace_difo_err;
7512 	int err = 0;
7513 	uint_t pc;
7514 
7515 	for (pc = 0; pc < dp->dtdo_len; pc++) {
7516 		dif_instr_t instr = dp->dtdo_buf[pc];
7517 
7518 		uint_t v = DIF_INSTR_VAR(instr);
7519 		uint_t subr = DIF_INSTR_SUBR(instr);
7520 		uint_t op = DIF_INSTR_OP(instr);
7521 
7522 		switch (op) {
7523 		case DIF_OP_OR:
7524 		case DIF_OP_XOR:
7525 		case DIF_OP_AND:
7526 		case DIF_OP_SLL:
7527 		case DIF_OP_SRL:
7528 		case DIF_OP_SRA:
7529 		case DIF_OP_SUB:
7530 		case DIF_OP_ADD:
7531 		case DIF_OP_MUL:
7532 		case DIF_OP_SDIV:
7533 		case DIF_OP_UDIV:
7534 		case DIF_OP_SREM:
7535 		case DIF_OP_UREM:
7536 		case DIF_OP_COPYS:
7537 		case DIF_OP_NOT:
7538 		case DIF_OP_MOV:
7539 		case DIF_OP_RLDSB:
7540 		case DIF_OP_RLDSH:
7541 		case DIF_OP_RLDSW:
7542 		case DIF_OP_RLDUB:
7543 		case DIF_OP_RLDUH:
7544 		case DIF_OP_RLDUW:
7545 		case DIF_OP_RLDX:
7546 		case DIF_OP_ULDSB:
7547 		case DIF_OP_ULDSH:
7548 		case DIF_OP_ULDSW:
7549 		case DIF_OP_ULDUB:
7550 		case DIF_OP_ULDUH:
7551 		case DIF_OP_ULDUW:
7552 		case DIF_OP_ULDX:
7553 		case DIF_OP_STB:
7554 		case DIF_OP_STH:
7555 		case DIF_OP_STW:
7556 		case DIF_OP_STX:
7557 		case DIF_OP_ALLOCS:
7558 		case DIF_OP_CMP:
7559 		case DIF_OP_SCMP:
7560 		case DIF_OP_TST:
7561 		case DIF_OP_BA:
7562 		case DIF_OP_BE:
7563 		case DIF_OP_BNE:
7564 		case DIF_OP_BG:
7565 		case DIF_OP_BGU:
7566 		case DIF_OP_BGE:
7567 		case DIF_OP_BGEU:
7568 		case DIF_OP_BL:
7569 		case DIF_OP_BLU:
7570 		case DIF_OP_BLE:
7571 		case DIF_OP_BLEU:
7572 		case DIF_OP_RET:
7573 		case DIF_OP_NOP:
7574 		case DIF_OP_POPTS:
7575 		case DIF_OP_FLUSHTS:
7576 		case DIF_OP_SETX:
7577 		case DIF_OP_SETS:
7578 		case DIF_OP_LDGA:
7579 		case DIF_OP_LDLS:
7580 		case DIF_OP_STGS:
7581 		case DIF_OP_STLS:
7582 		case DIF_OP_PUSHTR:
7583 		case DIF_OP_PUSHTV:
7584 			break;
7585 
7586 		case DIF_OP_LDGS:
7587 			if (v >= DIF_VAR_OTHER_UBASE)
7588 				break;
7589 
7590 			if (v >= DIF_VAR_ARG0 && v <= DIF_VAR_ARG9)
7591 				break;
7592 
7593 			if (v == DIF_VAR_CURTHREAD || v == DIF_VAR_PID ||
7594 			    v == DIF_VAR_PPID || v == DIF_VAR_TID ||
7595 			    v == DIF_VAR_EXECNAME || v == DIF_VAR_ZONENAME ||
7596 			    v == DIF_VAR_UID || v == DIF_VAR_GID)
7597 				break;
7598 
7599 			err += efunc(pc, "illegal variable %u\n", v);
7600 			break;
7601 
7602 		case DIF_OP_LDTA:
7603 		case DIF_OP_LDTS:
7604 		case DIF_OP_LDGAA:
7605 		case DIF_OP_LDTAA:
7606 			err += efunc(pc, "illegal dynamic variable load\n");
7607 			break;
7608 
7609 		case DIF_OP_STTS:
7610 		case DIF_OP_STGAA:
7611 		case DIF_OP_STTAA:
7612 			err += efunc(pc, "illegal dynamic variable store\n");
7613 			break;
7614 
7615 		case DIF_OP_CALL:
7616 			if (subr == DIF_SUBR_ALLOCA ||
7617 			    subr == DIF_SUBR_BCOPY ||
7618 			    subr == DIF_SUBR_COPYIN ||
7619 			    subr == DIF_SUBR_COPYINTO ||
7620 			    subr == DIF_SUBR_COPYINSTR ||
7621 			    subr == DIF_SUBR_INDEX ||
7622 			    subr == DIF_SUBR_LLTOSTR ||
7623 			    subr == DIF_SUBR_RINDEX ||
7624 			    subr == DIF_SUBR_STRCHR ||
7625 			    subr == DIF_SUBR_STRJOIN ||
7626 			    subr == DIF_SUBR_STRRCHR ||
7627 			    subr == DIF_SUBR_STRSTR ||
7628 			    subr == DIF_SUBR_HTONS ||
7629 			    subr == DIF_SUBR_HTONL ||
7630 			    subr == DIF_SUBR_HTONLL ||
7631 			    subr == DIF_SUBR_NTOHS ||
7632 			    subr == DIF_SUBR_NTOHL ||
7633 			    subr == DIF_SUBR_NTOHLL)
7634 				break;
7635 
7636 			err += efunc(pc, "invalid subr %u\n", subr);
7637 			break;
7638 
7639 		default:
7640 			err += efunc(pc, "invalid opcode %u\n",
7641 			    DIF_INSTR_OP(instr));
7642 		}
7643 	}
7644 
7645 	return (err);
7646 }
7647 
7648 /*
7649  * Returns 1 if the expression in the DIF object can be cached on a per-thread
7650  * basis; 0 if not.
7651  */
7652 static int
7653 dtrace_difo_cacheable(dtrace_difo_t *dp)
7654 {
7655 	int i;
7656 
7657 	if (dp == NULL)
7658 		return (0);
7659 
7660 	for (i = 0; i < dp->dtdo_varlen; i++) {
7661 		dtrace_difv_t *v = &dp->dtdo_vartab[i];
7662 
7663 		if (v->dtdv_scope != DIFV_SCOPE_GLOBAL)
7664 			continue;
7665 
7666 		switch (v->dtdv_id) {
7667 		case DIF_VAR_CURTHREAD:
7668 		case DIF_VAR_PID:
7669 		case DIF_VAR_TID:
7670 		case DIF_VAR_EXECNAME:
7671 		case DIF_VAR_ZONENAME:
7672 			break;
7673 
7674 		default:
7675 			return (0);
7676 		}
7677 	}
7678 
7679 	/*
7680 	 * This DIF object may be cacheable.  Now we need to look for any
7681 	 * array loading instructions, any memory loading instructions, or
7682 	 * any stores to thread-local variables.
7683 	 */
7684 	for (i = 0; i < dp->dtdo_len; i++) {
7685 		uint_t op = DIF_INSTR_OP(dp->dtdo_buf[i]);
7686 
7687 		if ((op >= DIF_OP_LDSB && op <= DIF_OP_LDX) ||
7688 		    (op >= DIF_OP_ULDSB && op <= DIF_OP_ULDX) ||
7689 		    (op >= DIF_OP_RLDSB && op <= DIF_OP_RLDX) ||
7690 		    op == DIF_OP_LDGA || op == DIF_OP_STTS)
7691 			return (0);
7692 	}
7693 
7694 	return (1);
7695 }
7696 
7697 static void
7698 dtrace_difo_hold(dtrace_difo_t *dp)
7699 {
7700 	int i;
7701 
7702 	ASSERT(MUTEX_HELD(&dtrace_lock));
7703 
7704 	dp->dtdo_refcnt++;
7705 	ASSERT(dp->dtdo_refcnt != 0);
7706 
7707 	/*
7708 	 * We need to check this DIF object for references to the variable
7709 	 * DIF_VAR_VTIMESTAMP.
7710 	 */
7711 	for (i = 0; i < dp->dtdo_varlen; i++) {
7712 		dtrace_difv_t *v = &dp->dtdo_vartab[i];
7713 
7714 		if (v->dtdv_id != DIF_VAR_VTIMESTAMP)
7715 			continue;
7716 
7717 		if (dtrace_vtime_references++ == 0)
7718 			dtrace_vtime_enable();
7719 	}
7720 }
7721 
7722 /*
7723  * This routine calculates the dynamic variable chunksize for a given DIF
7724  * object.  The calculation is not fool-proof, and can probably be tricked by
7725  * malicious DIF -- but it works for all compiler-generated DIF.  Because this
7726  * calculation is likely imperfect, dtrace_dynvar() is able to gracefully fail
7727  * if a dynamic variable size exceeds the chunksize.
7728  */
7729 static void
7730 dtrace_difo_chunksize(dtrace_difo_t *dp, dtrace_vstate_t *vstate)
7731 {
7732 	uint64_t sval;
7733 	dtrace_key_t tupregs[DIF_DTR_NREGS + 2]; /* +2 for thread and id */
7734 	const dif_instr_t *text = dp->dtdo_buf;
7735 	uint_t pc, srd = 0;
7736 	uint_t ttop = 0;
7737 	size_t size, ksize;
7738 	uint_t id, i;
7739 
7740 	for (pc = 0; pc < dp->dtdo_len; pc++) {
7741 		dif_instr_t instr = text[pc];
7742 		uint_t op = DIF_INSTR_OP(instr);
7743 		uint_t rd = DIF_INSTR_RD(instr);
7744 		uint_t r1 = DIF_INSTR_R1(instr);
7745 		uint_t nkeys = 0;
7746 		uchar_t scope;
7747 
7748 		dtrace_key_t *key = tupregs;
7749 
7750 		switch (op) {
7751 		case DIF_OP_SETX:
7752 			sval = dp->dtdo_inttab[DIF_INSTR_INTEGER(instr)];
7753 			srd = rd;
7754 			continue;
7755 
7756 		case DIF_OP_STTS:
7757 			key = &tupregs[DIF_DTR_NREGS];
7758 			key[0].dttk_size = 0;
7759 			key[1].dttk_size = 0;
7760 			nkeys = 2;
7761 			scope = DIFV_SCOPE_THREAD;
7762 			break;
7763 
7764 		case DIF_OP_STGAA:
7765 		case DIF_OP_STTAA:
7766 			nkeys = ttop;
7767 
7768 			if (DIF_INSTR_OP(instr) == DIF_OP_STTAA)
7769 				key[nkeys++].dttk_size = 0;
7770 
7771 			key[nkeys++].dttk_size = 0;
7772 
7773 			if (op == DIF_OP_STTAA) {
7774 				scope = DIFV_SCOPE_THREAD;
7775 			} else {
7776 				scope = DIFV_SCOPE_GLOBAL;
7777 			}
7778 
7779 			break;
7780 
7781 		case DIF_OP_PUSHTR:
7782 			if (ttop == DIF_DTR_NREGS)
7783 				return;
7784 
7785 			if ((srd == 0 || sval == 0) && r1 == DIF_TYPE_STRING) {
7786 				/*
7787 				 * If the register for the size of the "pushtr"
7788 				 * is %r0 (or the value is 0) and the type is
7789 				 * a string, we'll use the system-wide default
7790 				 * string size.
7791 				 */
7792 				tupregs[ttop++].dttk_size =
7793 				    dtrace_strsize_default;
7794 			} else {
7795 				if (srd == 0)
7796 					return;
7797 
7798 				tupregs[ttop++].dttk_size = sval;
7799 			}
7800 
7801 			break;
7802 
7803 		case DIF_OP_PUSHTV:
7804 			if (ttop == DIF_DTR_NREGS)
7805 				return;
7806 
7807 			tupregs[ttop++].dttk_size = 0;
7808 			break;
7809 
7810 		case DIF_OP_FLUSHTS:
7811 			ttop = 0;
7812 			break;
7813 
7814 		case DIF_OP_POPTS:
7815 			if (ttop != 0)
7816 				ttop--;
7817 			break;
7818 		}
7819 
7820 		sval = 0;
7821 		srd = 0;
7822 
7823 		if (nkeys == 0)
7824 			continue;
7825 
7826 		/*
7827 		 * We have a dynamic variable allocation; calculate its size.
7828 		 */
7829 		for (ksize = 0, i = 0; i < nkeys; i++)
7830 			ksize += P2ROUNDUP(key[i].dttk_size, sizeof (uint64_t));
7831 
7832 		size = sizeof (dtrace_dynvar_t);
7833 		size += sizeof (dtrace_key_t) * (nkeys - 1);
7834 		size += ksize;
7835 
7836 		/*
7837 		 * Now we need to determine the size of the stored data.
7838 		 */
7839 		id = DIF_INSTR_VAR(instr);
7840 
7841 		for (i = 0; i < dp->dtdo_varlen; i++) {
7842 			dtrace_difv_t *v = &dp->dtdo_vartab[i];
7843 
7844 			if (v->dtdv_id == id && v->dtdv_scope == scope) {
7845 				size += v->dtdv_type.dtdt_size;
7846 				break;
7847 			}
7848 		}
7849 
7850 		if (i == dp->dtdo_varlen)
7851 			return;
7852 
7853 		/*
7854 		 * We have the size.  If this is larger than the chunk size
7855 		 * for our dynamic variable state, reset the chunk size.
7856 		 */
7857 		size = P2ROUNDUP(size, sizeof (uint64_t));
7858 
7859 		if (size > vstate->dtvs_dynvars.dtds_chunksize)
7860 			vstate->dtvs_dynvars.dtds_chunksize = size;
7861 	}
7862 }
7863 
7864 static void
7865 dtrace_difo_init(dtrace_difo_t *dp, dtrace_vstate_t *vstate)
7866 {
7867 	int i, oldsvars, osz, nsz, otlocals, ntlocals;
7868 	uint_t id;
7869 
7870 	ASSERT(MUTEX_HELD(&dtrace_lock));
7871 	ASSERT(dp->dtdo_buf != NULL && dp->dtdo_len != 0);
7872 
7873 	for (i = 0; i < dp->dtdo_varlen; i++) {
7874 		dtrace_difv_t *v = &dp->dtdo_vartab[i];
7875 		dtrace_statvar_t *svar, ***svarp;
7876 		size_t dsize = 0;
7877 		uint8_t scope = v->dtdv_scope;
7878 		int *np;
7879 
7880 		if ((id = v->dtdv_id) < DIF_VAR_OTHER_UBASE)
7881 			continue;
7882 
7883 		id -= DIF_VAR_OTHER_UBASE;
7884 
7885 		switch (scope) {
7886 		case DIFV_SCOPE_THREAD:
7887 			while (id >= (otlocals = vstate->dtvs_ntlocals)) {
7888 				dtrace_difv_t *tlocals;
7889 
7890 				if ((ntlocals = (otlocals << 1)) == 0)
7891 					ntlocals = 1;
7892 
7893 				osz = otlocals * sizeof (dtrace_difv_t);
7894 				nsz = ntlocals * sizeof (dtrace_difv_t);
7895 
7896 				tlocals = kmem_zalloc(nsz, KM_SLEEP);
7897 
7898 				if (osz != 0) {
7899 					bcopy(vstate->dtvs_tlocals,
7900 					    tlocals, osz);
7901 					kmem_free(vstate->dtvs_tlocals, osz);
7902 				}
7903 
7904 				vstate->dtvs_tlocals = tlocals;
7905 				vstate->dtvs_ntlocals = ntlocals;
7906 			}
7907 
7908 			vstate->dtvs_tlocals[id] = *v;
7909 			continue;
7910 
7911 		case DIFV_SCOPE_LOCAL:
7912 			np = &vstate->dtvs_nlocals;
7913 			svarp = &vstate->dtvs_locals;
7914 
7915 			if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF)
7916 				dsize = NCPU * (v->dtdv_type.dtdt_size +
7917 				    sizeof (uint64_t));
7918 			else
7919 				dsize = NCPU * sizeof (uint64_t);
7920 
7921 			break;
7922 
7923 		case DIFV_SCOPE_GLOBAL:
7924 			np = &vstate->dtvs_nglobals;
7925 			svarp = &vstate->dtvs_globals;
7926 
7927 			if (v->dtdv_type.dtdt_flags & DIF_TF_BYREF)
7928 				dsize = v->dtdv_type.dtdt_size +
7929 				    sizeof (uint64_t);
7930 
7931 			break;
7932 
7933 		default:
7934 			ASSERT(0);
7935 		}
7936 
7937 		while (id >= (oldsvars = *np)) {
7938 			dtrace_statvar_t **statics;
7939 			int newsvars, oldsize, newsize;
7940 
7941 			if ((newsvars = (oldsvars << 1)) == 0)
7942 				newsvars = 1;
7943 
7944 			oldsize = oldsvars * sizeof (dtrace_statvar_t *);
7945 			newsize = newsvars * sizeof (dtrace_statvar_t *);
7946 
7947 			statics = kmem_zalloc(newsize, KM_SLEEP);
7948 
7949 			if (oldsize != 0) {
7950 				bcopy(*svarp, statics, oldsize);
7951 				kmem_free(*svarp, oldsize);
7952 			}
7953 
7954 			*svarp = statics;
7955 			*np = newsvars;
7956 		}
7957 
7958 		if ((svar = (*svarp)[id]) == NULL) {
7959 			svar = kmem_zalloc(sizeof (dtrace_statvar_t), KM_SLEEP);
7960 			svar->dtsv_var = *v;
7961 
7962 			if ((svar->dtsv_size = dsize) != 0) {
7963 				svar->dtsv_data = (uint64_t)(uintptr_t)
7964 				    kmem_zalloc(dsize, KM_SLEEP);
7965 			}
7966 
7967 			(*svarp)[id] = svar;
7968 		}
7969 
7970 		svar->dtsv_refcnt++;
7971 	}
7972 
7973 	dtrace_difo_chunksize(dp, vstate);
7974 	dtrace_difo_hold(dp);
7975 }
7976 
7977 static dtrace_difo_t *
7978 dtrace_difo_duplicate(dtrace_difo_t *dp, dtrace_vstate_t *vstate)
7979 {
7980 	dtrace_difo_t *new;
7981 	size_t sz;
7982 
7983 	ASSERT(dp->dtdo_buf != NULL);
7984 	ASSERT(dp->dtdo_refcnt != 0);
7985 
7986 	new = kmem_zalloc(sizeof (dtrace_difo_t), KM_SLEEP);
7987 
7988 	ASSERT(dp->dtdo_buf != NULL);
7989 	sz = dp->dtdo_len * sizeof (dif_instr_t);
7990 	new->dtdo_buf = kmem_alloc(sz, KM_SLEEP);
7991 	bcopy(dp->dtdo_buf, new->dtdo_buf, sz);
7992 	new->dtdo_len = dp->dtdo_len;
7993 
7994 	if (dp->dtdo_strtab != NULL) {
7995 		ASSERT(dp->dtdo_strlen != 0);
7996 		new->dtdo_strtab = kmem_alloc(dp->dtdo_strlen, KM_SLEEP);
7997 		bcopy(dp->dtdo_strtab, new->dtdo_strtab, dp->dtdo_strlen);
7998 		new->dtdo_strlen = dp->dtdo_strlen;
7999 	}
8000 
8001 	if (dp->dtdo_inttab != NULL) {
8002 		ASSERT(dp->dtdo_intlen != 0);
8003 		sz = dp->dtdo_intlen * sizeof (uint64_t);
8004 		new->dtdo_inttab = kmem_alloc(sz, KM_SLEEP);
8005 		bcopy(dp->dtdo_inttab, new->dtdo_inttab, sz);
8006 		new->dtdo_intlen = dp->dtdo_intlen;
8007 	}
8008 
8009 	if (dp->dtdo_vartab != NULL) {
8010 		ASSERT(dp->dtdo_varlen != 0);
8011 		sz = dp->dtdo_varlen * sizeof (dtrace_difv_t);
8012 		new->dtdo_vartab = kmem_alloc(sz, KM_SLEEP);
8013 		bcopy(dp->dtdo_vartab, new->dtdo_vartab, sz);
8014 		new->dtdo_varlen = dp->dtdo_varlen;
8015 	}
8016 
8017 	dtrace_difo_init(new, vstate);
8018 	return (new);
8019 }
8020 
8021 static void
8022 dtrace_difo_destroy(dtrace_difo_t *dp, dtrace_vstate_t *vstate)
8023 {
8024 	int i;
8025 
8026 	ASSERT(dp->dtdo_refcnt == 0);
8027 
8028 	for (i = 0; i < dp->dtdo_varlen; i++) {
8029 		dtrace_difv_t *v = &dp->dtdo_vartab[i];
8030 		dtrace_statvar_t *svar, **svarp;
8031 		uint_t id;
8032 		uint8_t scope = v->dtdv_scope;
8033 		int *np;
8034 
8035 		switch (scope) {
8036 		case DIFV_SCOPE_THREAD:
8037 			continue;
8038 
8039 		case DIFV_SCOPE_LOCAL:
8040 			np = &vstate->dtvs_nlocals;
8041 			svarp = vstate->dtvs_locals;
8042 			break;
8043 
8044 		case DIFV_SCOPE_GLOBAL:
8045 			np = &vstate->dtvs_nglobals;
8046 			svarp = vstate->dtvs_globals;
8047 			break;
8048 
8049 		default:
8050 			ASSERT(0);
8051 		}
8052 
8053 		if ((id = v->dtdv_id) < DIF_VAR_OTHER_UBASE)
8054 			continue;
8055 
8056 		id -= DIF_VAR_OTHER_UBASE;
8057 		ASSERT(id < *np);
8058 
8059 		svar = svarp[id];
8060 		ASSERT(svar != NULL);
8061 		ASSERT(svar->dtsv_refcnt > 0);
8062 
8063 		if (--svar->dtsv_refcnt > 0)
8064 			continue;
8065 
8066 		if (svar->dtsv_size != 0) {
8067 			ASSERT(svar->dtsv_data != NULL);
8068 			kmem_free((void *)(uintptr_t)svar->dtsv_data,
8069 			    svar->dtsv_size);
8070 		}
8071 
8072 		kmem_free(svar, sizeof (dtrace_statvar_t));
8073 		svarp[id] = NULL;
8074 	}
8075 
8076 	kmem_free(dp->dtdo_buf, dp->dtdo_len * sizeof (dif_instr_t));
8077 	kmem_free(dp->dtdo_inttab, dp->dtdo_intlen * sizeof (uint64_t));
8078 	kmem_free(dp->dtdo_strtab, dp->dtdo_strlen);
8079 	kmem_free(dp->dtdo_vartab, dp->dtdo_varlen * sizeof (dtrace_difv_t));
8080 
8081 	kmem_free(dp, sizeof (dtrace_difo_t));
8082 }
8083 
8084 static void
8085 dtrace_difo_release(dtrace_difo_t *dp, dtrace_vstate_t *vstate)
8086 {
8087 	int i;
8088 
8089 	ASSERT(MUTEX_HELD(&dtrace_lock));
8090 	ASSERT(dp->dtdo_refcnt != 0);
8091 
8092 	for (i = 0; i < dp->dtdo_varlen; i++) {
8093 		dtrace_difv_t *v = &dp->dtdo_vartab[i];
8094 
8095 		if (v->dtdv_id != DIF_VAR_VTIMESTAMP)
8096 			continue;
8097 
8098 		ASSERT(dtrace_vtime_references > 0);
8099 		if (--dtrace_vtime_references == 0)
8100 			dtrace_vtime_disable();
8101 	}
8102 
8103 	if (--dp->dtdo_refcnt == 0)
8104 		dtrace_difo_destroy(dp, vstate);
8105 }
8106 
8107 /*
8108  * DTrace Format Functions
8109  */
8110 static uint16_t
8111 dtrace_format_add(dtrace_state_t *state, char *str)
8112 {
8113 	char *fmt, **new;
8114 	uint16_t ndx, len = strlen(str) + 1;
8115 
8116 	fmt = kmem_zalloc(len, KM_SLEEP);
8117 	bcopy(str, fmt, len);
8118 
8119 	for (ndx = 0; ndx < state->dts_nformats; ndx++) {
8120 		if (state->dts_formats[ndx] == NULL) {
8121 			state->dts_formats[ndx] = fmt;
8122 			return (ndx + 1);
8123 		}
8124 	}
8125 
8126 	if (state->dts_nformats == USHRT_MAX) {
8127 		/*
8128 		 * This is only likely if a denial-of-service attack is being
8129 		 * attempted.  As such, it's okay to fail silently here.
8130 		 */
8131 		kmem_free(fmt, len);
8132 		return (0);
8133 	}
8134 
8135 	/*
8136 	 * For simplicity, we always resize the formats array to be exactly the
8137 	 * number of formats.
8138 	 */
8139 	ndx = state->dts_nformats++;
8140 	new = kmem_alloc((ndx + 1) * sizeof (char *), KM_SLEEP);
8141 
8142 	if (state->dts_formats != NULL) {
8143 		ASSERT(ndx != 0);
8144 		bcopy(state->dts_formats, new, ndx * sizeof (char *));
8145 		kmem_free(state->dts_formats, ndx * sizeof (char *));
8146 	}
8147 
8148 	state->dts_formats = new;
8149 	state->dts_formats[ndx] = fmt;
8150 
8151 	return (ndx + 1);
8152 }
8153 
8154 static void
8155 dtrace_format_remove(dtrace_state_t *state, uint16_t format)
8156 {
8157 	char *fmt;
8158 
8159 	ASSERT(state->dts_formats != NULL);
8160 	ASSERT(format <= state->dts_nformats);
8161 	ASSERT(state->dts_formats[format - 1] != NULL);
8162 
8163 	fmt = state->dts_formats[format - 1];
8164 	kmem_free(fmt, strlen(fmt) + 1);
8165 	state->dts_formats[format - 1] = NULL;
8166 }
8167 
8168 static void
8169 dtrace_format_destroy(dtrace_state_t *state)
8170 {
8171 	int i;
8172 
8173 	if (state->dts_nformats == 0) {
8174 		ASSERT(state->dts_formats == NULL);
8175 		return;
8176 	}
8177 
8178 	ASSERT(state->dts_formats != NULL);
8179 
8180 	for (i = 0; i < state->dts_nformats; i++) {
8181 		char *fmt = state->dts_formats[i];
8182 
8183 		if (fmt == NULL)
8184 			continue;
8185 
8186 		kmem_free(fmt, strlen(fmt) + 1);
8187 	}
8188 
8189 	kmem_free(state->dts_formats, state->dts_nformats * sizeof (char *));
8190 	state->dts_nformats = 0;
8191 	state->dts_formats = NULL;
8192 }
8193 
8194 /*
8195  * DTrace Predicate Functions
8196  */
8197 static dtrace_predicate_t *
8198 dtrace_predicate_create(dtrace_difo_t *dp)
8199 {
8200 	dtrace_predicate_t *pred;
8201 
8202 	ASSERT(MUTEX_HELD(&dtrace_lock));
8203 	ASSERT(dp->dtdo_refcnt != 0);
8204 
8205 	pred = kmem_zalloc(sizeof (dtrace_predicate_t), KM_SLEEP);
8206 	pred->dtp_difo = dp;
8207 	pred->dtp_refcnt = 1;
8208 
8209 	if (!dtrace_difo_cacheable(dp))
8210 		return (pred);
8211 
8212 	if (dtrace_predcache_id == DTRACE_CACHEIDNONE) {
8213 		/*
8214 		 * This is only theoretically possible -- we have had 2^32
8215 		 * cacheable predicates on this machine.  We cannot allow any
8216 		 * more predicates to become cacheable:  as unlikely as it is,
8217 		 * there may be a thread caching a (now stale) predicate cache
8218 		 * ID. (N.B.: the temptation is being successfully resisted to
8219 		 * have this cmn_err() "Holy shit -- we executed this code!")
8220 		 */
8221 		return (pred);
8222 	}
8223 
8224 	pred->dtp_cacheid = dtrace_predcache_id++;
8225 
8226 	return (pred);
8227 }
8228 
8229 static void
8230 dtrace_predicate_hold(dtrace_predicate_t *pred)
8231 {
8232 	ASSERT(MUTEX_HELD(&dtrace_lock));
8233 	ASSERT(pred->dtp_difo != NULL && pred->dtp_difo->dtdo_refcnt != 0);
8234 	ASSERT(pred->dtp_refcnt > 0);
8235 
8236 	pred->dtp_refcnt++;
8237 }
8238 
8239 static void
8240 dtrace_predicate_release(dtrace_predicate_t *pred, dtrace_vstate_t *vstate)
8241 {
8242 	dtrace_difo_t *dp = pred->dtp_difo;
8243 
8244 	ASSERT(MUTEX_HELD(&dtrace_lock));
8245 	ASSERT(dp != NULL && dp->dtdo_refcnt != 0);
8246 	ASSERT(pred->dtp_refcnt > 0);
8247 
8248 	if (--pred->dtp_refcnt == 0) {
8249 		dtrace_difo_release(pred->dtp_difo, vstate);
8250 		kmem_free(pred, sizeof (dtrace_predicate_t));
8251 	}
8252 }
8253 
8254 /*
8255  * DTrace Action Description Functions
8256  */
8257 static dtrace_actdesc_t *
8258 dtrace_actdesc_create(dtrace_actkind_t kind, uint32_t ntuple,
8259     uint64_t uarg, uint64_t arg)
8260 {
8261 	dtrace_actdesc_t *act;
8262 
8263 	ASSERT(!DTRACEACT_ISPRINTFLIKE(kind) || (arg != NULL &&
8264 	    arg >= KERNELBASE) || (arg == NULL && kind == DTRACEACT_PRINTA));
8265 
8266 	act = kmem_zalloc(sizeof (dtrace_actdesc_t), KM_SLEEP);
8267 	act->dtad_kind = kind;
8268 	act->dtad_ntuple = ntuple;
8269 	act->dtad_uarg = uarg;
8270 	act->dtad_arg = arg;
8271 	act->dtad_refcnt = 1;
8272 
8273 	return (act);
8274 }
8275 
8276 static void
8277 dtrace_actdesc_hold(dtrace_actdesc_t *act)
8278 {
8279 	ASSERT(act->dtad_refcnt >= 1);
8280 	act->dtad_refcnt++;
8281 }
8282 
8283 static void
8284 dtrace_actdesc_release(dtrace_actdesc_t *act, dtrace_vstate_t *vstate)
8285 {
8286 	dtrace_actkind_t kind = act->dtad_kind;
8287 	dtrace_difo_t *dp;
8288 
8289 	ASSERT(act->dtad_refcnt >= 1);
8290 
8291 	if (--act->dtad_refcnt != 0)
8292 		return;
8293 
8294 	if ((dp = act->dtad_difo) != NULL)
8295 		dtrace_difo_release(dp, vstate);
8296 
8297 	if (DTRACEACT_ISPRINTFLIKE(kind)) {
8298 		char *str = (char *)(uintptr_t)act->dtad_arg;
8299 
8300 		ASSERT((str != NULL && (uintptr_t)str >= KERNELBASE) ||
8301 		    (str == NULL && act->dtad_kind == DTRACEACT_PRINTA));
8302 
8303 		if (str != NULL)
8304 			kmem_free(str, strlen(str) + 1);
8305 	}
8306 
8307 	kmem_free(act, sizeof (dtrace_actdesc_t));
8308 }
8309 
8310 /*
8311  * DTrace ECB Functions
8312  */
8313 static dtrace_ecb_t *
8314 dtrace_ecb_add(dtrace_state_t *state, dtrace_probe_t *probe)
8315 {
8316 	dtrace_ecb_t *ecb;
8317 	dtrace_epid_t epid;
8318 
8319 	ASSERT(MUTEX_HELD(&dtrace_lock));
8320 
8321 	ecb = kmem_zalloc(sizeof (dtrace_ecb_t), KM_SLEEP);
8322 	ecb->dte_predicate = NULL;
8323 	ecb->dte_probe = probe;
8324 
8325 	/*
8326 	 * The default size is the size of the default action: recording
8327 	 * the epid.
8328 	 */
8329 	ecb->dte_size = ecb->dte_needed = sizeof (dtrace_epid_t);
8330 	ecb->dte_alignment = sizeof (dtrace_epid_t);
8331 
8332 	epid = state->dts_epid++;
8333 
8334 	if (epid - 1 >= state->dts_necbs) {
8335 		dtrace_ecb_t **oecbs = state->dts_ecbs, **ecbs;
8336 		int necbs = state->dts_necbs << 1;
8337 
8338 		ASSERT(epid == state->dts_necbs + 1);
8339 
8340 		if (necbs == 0) {
8341 			ASSERT(oecbs == NULL);
8342 			necbs = 1;
8343 		}
8344 
8345 		ecbs = kmem_zalloc(necbs * sizeof (*ecbs), KM_SLEEP);
8346 
8347 		if (oecbs != NULL)
8348 			bcopy(oecbs, ecbs, state->dts_necbs * sizeof (*ecbs));
8349 
8350 		dtrace_membar_producer();
8351 		state->dts_ecbs = ecbs;
8352 
8353 		if (oecbs != NULL) {
8354 			/*
8355 			 * If this state is active, we must dtrace_sync()
8356 			 * before we can free the old dts_ecbs array:  we're
8357 			 * coming in hot, and there may be active ring
8358 			 * buffer processing (which indexes into the dts_ecbs
8359 			 * array) on another CPU.
8360 			 */
8361 			if (state->dts_activity != DTRACE_ACTIVITY_INACTIVE)
8362 				dtrace_sync();
8363 
8364 			kmem_free(oecbs, state->dts_necbs * sizeof (*ecbs));
8365 		}
8366 
8367 		dtrace_membar_producer();
8368 		state->dts_necbs = necbs;
8369 	}
8370 
8371 	ecb->dte_state = state;
8372 
8373 	ASSERT(state->dts_ecbs[epid - 1] == NULL);
8374 	dtrace_membar_producer();
8375 	state->dts_ecbs[(ecb->dte_epid = epid) - 1] = ecb;
8376 
8377 	return (ecb);
8378 }
8379 
8380 static void
8381 dtrace_ecb_enable(dtrace_ecb_t *ecb)
8382 {
8383 	dtrace_probe_t *probe = ecb->dte_probe;
8384 
8385 	ASSERT(MUTEX_HELD(&cpu_lock));
8386 	ASSERT(MUTEX_HELD(&dtrace_lock));
8387 	ASSERT(ecb->dte_next == NULL);
8388 
8389 	if (probe == NULL) {
8390 		/*
8391 		 * This is the NULL probe -- there's nothing to do.
8392 		 */
8393 		return;
8394 	}
8395 
8396 	if (probe->dtpr_ecb == NULL) {
8397 		dtrace_provider_t *prov = probe->dtpr_provider;
8398 
8399 		/*
8400 		 * We're the first ECB on this probe.
8401 		 */
8402 		probe->dtpr_ecb = probe->dtpr_ecb_last = ecb;
8403 
8404 		if (ecb->dte_predicate != NULL)
8405 			probe->dtpr_predcache = ecb->dte_predicate->dtp_cacheid;
8406 
8407 		prov->dtpv_pops.dtps_enable(prov->dtpv_arg,
8408 		    probe->dtpr_id, probe->dtpr_arg);
8409 	} else {
8410 		/*
8411 		 * This probe is already active.  Swing the last pointer to
8412 		 * point to the new ECB, and issue a dtrace_sync() to assure
8413 		 * that all CPUs have seen the change.
8414 		 */
8415 		ASSERT(probe->dtpr_ecb_last != NULL);
8416 		probe->dtpr_ecb_last->dte_next = ecb;
8417 		probe->dtpr_ecb_last = ecb;
8418 		probe->dtpr_predcache = 0;
8419 
8420 		dtrace_sync();
8421 	}
8422 }
8423 
8424 static void
8425 dtrace_ecb_resize(dtrace_ecb_t *ecb)
8426 {
8427 	uint32_t maxalign = sizeof (dtrace_epid_t);
8428 	uint32_t align = sizeof (uint8_t), offs, diff;
8429 	dtrace_action_t *act;
8430 	int wastuple = 0;
8431 	uint32_t aggbase = UINT32_MAX;
8432 	dtrace_state_t *state = ecb->dte_state;
8433 
8434 	/*
8435 	 * If we record anything, we always record the epid.  (And we always
8436 	 * record it first.)
8437 	 */
8438 	offs = sizeof (dtrace_epid_t);
8439 	ecb->dte_size = ecb->dte_needed = sizeof (dtrace_epid_t);
8440 
8441 	for (act = ecb->dte_action; act != NULL; act = act->dta_next) {
8442 		dtrace_recdesc_t *rec = &act->dta_rec;
8443 
8444 		if ((align = rec->dtrd_alignment) > maxalign)
8445 			maxalign = align;
8446 
8447 		if (!wastuple && act->dta_intuple) {
8448 			/*
8449 			 * This is the first record in a tuple.  Align the
8450 			 * offset to be at offset 4 in an 8-byte aligned
8451 			 * block.
8452 			 */
8453 			diff = offs + sizeof (dtrace_aggid_t);
8454 
8455 			if (diff = (diff & (sizeof (uint64_t) - 1)))
8456 				offs += sizeof (uint64_t) - diff;
8457 
8458 			aggbase = offs - sizeof (dtrace_aggid_t);
8459 			ASSERT(!(aggbase & (sizeof (uint64_t) - 1)));
8460 		}
8461 
8462 		/*LINTED*/
8463 		if (rec->dtrd_size != 0 && (diff = (offs & (align - 1)))) {
8464 			/*
8465 			 * The current offset is not properly aligned; align it.
8466 			 */
8467 			offs += align - diff;
8468 		}
8469 
8470 		rec->dtrd_offset = offs;
8471 
8472 		if (offs + rec->dtrd_size > ecb->dte_needed) {
8473 			ecb->dte_needed = offs + rec->dtrd_size;
8474 
8475 			if (ecb->dte_needed > state->dts_needed)
8476 				state->dts_needed = ecb->dte_needed;
8477 		}
8478 
8479 		if (DTRACEACT_ISAGG(act->dta_kind)) {
8480 			dtrace_aggregation_t *agg = (dtrace_aggregation_t *)act;
8481 			dtrace_action_t *first = agg->dtag_first, *prev;
8482 
8483 			ASSERT(rec->dtrd_size != 0 && first != NULL);
8484 			ASSERT(wastuple);
8485 			ASSERT(aggbase != UINT32_MAX);
8486 
8487 			agg->dtag_base = aggbase;
8488 
8489 			while ((prev = first->dta_prev) != NULL &&
8490 			    DTRACEACT_ISAGG(prev->dta_kind)) {
8491 				agg = (dtrace_aggregation_t *)prev;
8492 				first = agg->dtag_first;
8493 			}
8494 
8495 			if (prev != NULL) {
8496 				offs = prev->dta_rec.dtrd_offset +
8497 				    prev->dta_rec.dtrd_size;
8498 			} else {
8499 				offs = sizeof (dtrace_epid_t);
8500 			}
8501 			wastuple = 0;
8502 		} else {
8503 			if (!act->dta_intuple)
8504 				ecb->dte_size = offs + rec->dtrd_size;
8505 
8506 			offs += rec->dtrd_size;
8507 		}
8508 
8509 		wastuple = act->dta_intuple;
8510 	}
8511 
8512 	if ((act = ecb->dte_action) != NULL &&
8513 	    !(act->dta_kind == DTRACEACT_SPECULATE && act->dta_next == NULL) &&
8514 	    ecb->dte_size == sizeof (dtrace_epid_t)) {
8515 		/*
8516 		 * If the size is still sizeof (dtrace_epid_t), then all
8517 		 * actions store no data; set the size to 0.
8518 		 */
8519 		ecb->dte_alignment = maxalign;
8520 		ecb->dte_size = 0;
8521 
8522 		/*
8523 		 * If the needed space is still sizeof (dtrace_epid_t), then
8524 		 * all actions need no additional space; set the needed
8525 		 * size to 0.
8526 		 */
8527 		if (ecb->dte_needed == sizeof (dtrace_epid_t))
8528 			ecb->dte_needed = 0;
8529 
8530 		return;
8531 	}
8532 
8533 	/*
8534 	 * Set our alignment, and make sure that the dte_size and dte_needed
8535 	 * are aligned to the size of an EPID.
8536 	 */
8537 	ecb->dte_alignment = maxalign;
8538 	ecb->dte_size = (ecb->dte_size + (sizeof (dtrace_epid_t) - 1)) &
8539 	    ~(sizeof (dtrace_epid_t) - 1);
8540 	ecb->dte_needed = (ecb->dte_needed + (sizeof (dtrace_epid_t) - 1)) &
8541 	    ~(sizeof (dtrace_epid_t) - 1);
8542 	ASSERT(ecb->dte_size <= ecb->dte_needed);
8543 }
8544 
8545 static dtrace_action_t *
8546 dtrace_ecb_aggregation_create(dtrace_ecb_t *ecb, dtrace_actdesc_t *desc)
8547 {
8548 	dtrace_aggregation_t *agg;
8549 	size_t size = sizeof (uint64_t);
8550 	int ntuple = desc->dtad_ntuple;
8551 	dtrace_action_t *act;
8552 	dtrace_recdesc_t *frec;
8553 	dtrace_aggid_t aggid;
8554 	dtrace_state_t *state = ecb->dte_state;
8555 
8556 	agg = kmem_zalloc(sizeof (dtrace_aggregation_t), KM_SLEEP);
8557 	agg->dtag_ecb = ecb;
8558 
8559 	ASSERT(DTRACEACT_ISAGG(desc->dtad_kind));
8560 
8561 	switch (desc->dtad_kind) {
8562 	case DTRACEAGG_MIN:
8563 		agg->dtag_initial = UINT64_MAX;
8564 		agg->dtag_aggregate = dtrace_aggregate_min;
8565 		break;
8566 
8567 	case DTRACEAGG_MAX:
8568 		agg->dtag_aggregate = dtrace_aggregate_max;
8569 		break;
8570 
8571 	case DTRACEAGG_COUNT:
8572 		agg->dtag_aggregate = dtrace_aggregate_count;
8573 		break;
8574 
8575 	case DTRACEAGG_QUANTIZE:
8576 		agg->dtag_aggregate = dtrace_aggregate_quantize;
8577 		size = (((sizeof (uint64_t) * NBBY) - 1) * 2 + 1) *
8578 		    sizeof (uint64_t);
8579 		break;
8580 
8581 	case DTRACEAGG_LQUANTIZE: {
8582 		uint16_t step = DTRACE_LQUANTIZE_STEP(desc->dtad_arg);
8583 		uint16_t levels = DTRACE_LQUANTIZE_LEVELS(desc->dtad_arg);
8584 
8585 		agg->dtag_initial = desc->dtad_arg;
8586 		agg->dtag_aggregate = dtrace_aggregate_lquantize;
8587 
8588 		if (step == 0 || levels == 0)
8589 			goto err;
8590 
8591 		size = levels * sizeof (uint64_t) + 3 * sizeof (uint64_t);
8592 		break;
8593 	}
8594 
8595 	case DTRACEAGG_AVG:
8596 		agg->dtag_aggregate = dtrace_aggregate_avg;
8597 		size = sizeof (uint64_t) * 2;
8598 		break;
8599 
8600 	case DTRACEAGG_SUM:
8601 		agg->dtag_aggregate = dtrace_aggregate_sum;
8602 		break;
8603 
8604 	default:
8605 		goto err;
8606 	}
8607 
8608 	agg->dtag_action.dta_rec.dtrd_size = size;
8609 
8610 	if (ntuple == 0)
8611 		goto err;
8612 
8613 	/*
8614 	 * We must make sure that we have enough actions for the n-tuple.
8615 	 */
8616 	for (act = ecb->dte_action_last; act != NULL; act = act->dta_prev) {
8617 		if (DTRACEACT_ISAGG(act->dta_kind))
8618 			break;
8619 
8620 		if (--ntuple == 0) {
8621 			/*
8622 			 * This is the action with which our n-tuple begins.
8623 			 */
8624 			agg->dtag_first = act;
8625 			goto success;
8626 		}
8627 	}
8628 
8629 	/*
8630 	 * This n-tuple is short by ntuple elements.  Return failure.
8631 	 */
8632 	ASSERT(ntuple != 0);
8633 err:
8634 	kmem_free(agg, sizeof (dtrace_aggregation_t));
8635 	return (NULL);
8636 
8637 success:
8638 	/*
8639 	 * If the last action in the tuple has a size of zero, it's actually
8640 	 * an expression argument for the aggregating action.
8641 	 */
8642 	ASSERT(ecb->dte_action_last != NULL);
8643 	act = ecb->dte_action_last;
8644 
8645 	if (act->dta_kind == DTRACEACT_DIFEXPR) {
8646 		ASSERT(act->dta_difo != NULL);
8647 
8648 		if (act->dta_difo->dtdo_rtype.dtdt_size == 0)
8649 			agg->dtag_hasarg = 1;
8650 	}
8651 
8652 	/*
8653 	 * We need to allocate an id for this aggregation.
8654 	 */
8655 	aggid = (dtrace_aggid_t)(uintptr_t)vmem_alloc(state->dts_aggid_arena, 1,
8656 	    VM_BESTFIT | VM_SLEEP);
8657 
8658 	if (aggid - 1 >= state->dts_naggregations) {
8659 		dtrace_aggregation_t **oaggs = state->dts_aggregations;
8660 		dtrace_aggregation_t **aggs;
8661 		int naggs = state->dts_naggregations << 1;
8662 		int onaggs = state->dts_naggregations;
8663 
8664 		ASSERT(aggid == state->dts_naggregations + 1);
8665 
8666 		if (naggs == 0) {
8667 			ASSERT(oaggs == NULL);
8668 			naggs = 1;
8669 		}
8670 
8671 		aggs = kmem_zalloc(naggs * sizeof (*aggs), KM_SLEEP);
8672 
8673 		if (oaggs != NULL) {
8674 			bcopy(oaggs, aggs, onaggs * sizeof (*aggs));
8675 			kmem_free(oaggs, onaggs * sizeof (*aggs));
8676 		}
8677 
8678 		state->dts_aggregations = aggs;
8679 		state->dts_naggregations = naggs;
8680 	}
8681 
8682 	ASSERT(state->dts_aggregations[aggid - 1] == NULL);
8683 	state->dts_aggregations[(agg->dtag_id = aggid) - 1] = agg;
8684 
8685 	frec = &agg->dtag_first->dta_rec;
8686 	if (frec->dtrd_alignment < sizeof (dtrace_aggid_t))
8687 		frec->dtrd_alignment = sizeof (dtrace_aggid_t);
8688 
8689 	for (act = agg->dtag_first; act != NULL; act = act->dta_next) {
8690 		ASSERT(!act->dta_intuple);
8691 		act->dta_intuple = 1;
8692 	}
8693 
8694 	return (&agg->dtag_action);
8695 }
8696 
8697 static void
8698 dtrace_ecb_aggregation_destroy(dtrace_ecb_t *ecb, dtrace_action_t *act)
8699 {
8700 	dtrace_aggregation_t *agg = (dtrace_aggregation_t *)act;
8701 	dtrace_state_t *state = ecb->dte_state;
8702 	dtrace_aggid_t aggid = agg->dtag_id;
8703 
8704 	ASSERT(DTRACEACT_ISAGG(act->dta_kind));
8705 	vmem_free(state->dts_aggid_arena, (void *)(uintptr_t)aggid, 1);
8706 
8707 	ASSERT(state->dts_aggregations[aggid - 1] == agg);
8708 	state->dts_aggregations[aggid - 1] = NULL;
8709 
8710 	kmem_free(agg, sizeof (dtrace_aggregation_t));
8711 }
8712 
8713 static int
8714 dtrace_ecb_action_add(dtrace_ecb_t *ecb, dtrace_actdesc_t *desc)
8715 {
8716 	dtrace_action_t *action, *last;
8717 	dtrace_difo_t *dp = desc->dtad_difo;
8718 	uint32_t size = 0, align = sizeof (uint8_t), mask;
8719 	uint16_t format = 0;
8720 	dtrace_recdesc_t *rec;
8721 	dtrace_state_t *state = ecb->dte_state;
8722 	dtrace_optval_t *opt = state->dts_options, nframes, strsize;
8723 	uint64_t arg = desc->dtad_arg;
8724 
8725 	ASSERT(MUTEX_HELD(&dtrace_lock));
8726 	ASSERT(ecb->dte_action == NULL || ecb->dte_action->dta_refcnt == 1);
8727 
8728 	if (DTRACEACT_ISAGG(desc->dtad_kind)) {
8729 		/*
8730 		 * If this is an aggregating action, there must be neither
8731 		 * a speculate nor a commit on the action chain.
8732 		 */
8733 		dtrace_action_t *act;
8734 
8735 		for (act = ecb->dte_action; act != NULL; act = act->dta_next) {
8736 			if (act->dta_kind == DTRACEACT_COMMIT)
8737 				return (EINVAL);
8738 
8739 			if (act->dta_kind == DTRACEACT_SPECULATE)
8740 				return (EINVAL);
8741 		}
8742 
8743 		action = dtrace_ecb_aggregation_create(ecb, desc);
8744 
8745 		if (action == NULL)
8746 			return (EINVAL);
8747 	} else {
8748 		if (DTRACEACT_ISDESTRUCTIVE(desc->dtad_kind) ||
8749 		    (desc->dtad_kind == DTRACEACT_DIFEXPR &&
8750 		    dp != NULL && dp->dtdo_destructive)) {
8751 			state->dts_destructive = 1;
8752 		}
8753 
8754 		switch (desc->dtad_kind) {
8755 		case DTRACEACT_PRINTF:
8756 		case DTRACEACT_PRINTA:
8757 		case DTRACEACT_SYSTEM:
8758 		case DTRACEACT_FREOPEN:
8759 			/*
8760 			 * We know that our arg is a string -- turn it into a
8761 			 * format.
8762 			 */
8763 			if (arg == NULL) {
8764 				ASSERT(desc->dtad_kind == DTRACEACT_PRINTA);
8765 				format = 0;
8766 			} else {
8767 				ASSERT(arg != NULL);
8768 				ASSERT(arg > KERNELBASE);
8769 				format = dtrace_format_add(state,
8770 				    (char *)(uintptr_t)arg);
8771 			}
8772 
8773 			/*FALLTHROUGH*/
8774 		case DTRACEACT_LIBACT:
8775 		case DTRACEACT_DIFEXPR:
8776 			if (dp == NULL)
8777 				return (EINVAL);
8778 
8779 			if ((size = dp->dtdo_rtype.dtdt_size) != 0)
8780 				break;
8781 
8782 			if (dp->dtdo_rtype.dtdt_kind == DIF_TYPE_STRING) {
8783 				if (!(dp->dtdo_rtype.dtdt_flags & DIF_TF_BYREF))
8784 					return (EINVAL);
8785 
8786 				size = opt[DTRACEOPT_STRSIZE];
8787 			}
8788 
8789 			break;
8790 
8791 		case DTRACEACT_STACK:
8792 			if ((nframes = arg) == 0) {
8793 				nframes = opt[DTRACEOPT_STACKFRAMES];
8794 				ASSERT(nframes > 0);
8795 				arg = nframes;
8796 			}
8797 
8798 			size = nframes * sizeof (pc_t);
8799 			break;
8800 
8801 		case DTRACEACT_JSTACK:
8802 			if ((strsize = DTRACE_USTACK_STRSIZE(arg)) == 0)
8803 				strsize = opt[DTRACEOPT_JSTACKSTRSIZE];
8804 
8805 			if ((nframes = DTRACE_USTACK_NFRAMES(arg)) == 0)
8806 				nframes = opt[DTRACEOPT_JSTACKFRAMES];
8807 
8808 			arg = DTRACE_USTACK_ARG(nframes, strsize);
8809 
8810 			/*FALLTHROUGH*/
8811 		case DTRACEACT_USTACK:
8812 			if (desc->dtad_kind != DTRACEACT_JSTACK &&
8813 			    (nframes = DTRACE_USTACK_NFRAMES(arg)) == 0) {
8814 				strsize = DTRACE_USTACK_STRSIZE(arg);
8815 				nframes = opt[DTRACEOPT_USTACKFRAMES];
8816 				ASSERT(nframes > 0);
8817 				arg = DTRACE_USTACK_ARG(nframes, strsize);
8818 			}
8819 
8820 			/*
8821 			 * Save a slot for the pid.
8822 			 */
8823 			size = (nframes + 1) * sizeof (uint64_t);
8824 			size += DTRACE_USTACK_STRSIZE(arg);
8825 			size = P2ROUNDUP(size, (uint32_t)(sizeof (uintptr_t)));
8826 
8827 			break;
8828 
8829 		case DTRACEACT_SYM:
8830 		case DTRACEACT_MOD:
8831 			if (dp == NULL || ((size = dp->dtdo_rtype.dtdt_size) !=
8832 			    sizeof (uint64_t)) ||
8833 			    (dp->dtdo_rtype.dtdt_flags & DIF_TF_BYREF))
8834 				return (EINVAL);
8835 			break;
8836 
8837 		case DTRACEACT_USYM:
8838 		case DTRACEACT_UMOD:
8839 		case DTRACEACT_UADDR:
8840 			if (dp == NULL ||
8841 			    (dp->dtdo_rtype.dtdt_size != sizeof (uint64_t)) ||
8842 			    (dp->dtdo_rtype.dtdt_flags & DIF_TF_BYREF))
8843 				return (EINVAL);
8844 
8845 			/*
8846 			 * We have a slot for the pid, plus a slot for the
8847 			 * argument.  To keep things simple (aligned with
8848 			 * bitness-neutral sizing), we store each as a 64-bit
8849 			 * quantity.
8850 			 */
8851 			size = 2 * sizeof (uint64_t);
8852 			break;
8853 
8854 		case DTRACEACT_STOP:
8855 		case DTRACEACT_BREAKPOINT:
8856 		case DTRACEACT_PANIC:
8857 			break;
8858 
8859 		case DTRACEACT_CHILL:
8860 		case DTRACEACT_DISCARD:
8861 		case DTRACEACT_RAISE:
8862 			if (dp == NULL)
8863 				return (EINVAL);
8864 			break;
8865 
8866 		case DTRACEACT_EXIT:
8867 			if (dp == NULL ||
8868 			    (size = dp->dtdo_rtype.dtdt_size) != sizeof (int) ||
8869 			    (dp->dtdo_rtype.dtdt_flags & DIF_TF_BYREF))
8870 				return (EINVAL);
8871 			break;
8872 
8873 		case DTRACEACT_SPECULATE:
8874 			if (ecb->dte_size > sizeof (dtrace_epid_t))
8875 				return (EINVAL);
8876 
8877 			if (dp == NULL)
8878 				return (EINVAL);
8879 
8880 			state->dts_speculates = 1;
8881 			break;
8882 
8883 		case DTRACEACT_COMMIT: {
8884 			dtrace_action_t *act = ecb->dte_action;
8885 
8886 			for (; act != NULL; act = act->dta_next) {
8887 				if (act->dta_kind == DTRACEACT_COMMIT)
8888 					return (EINVAL);
8889 			}
8890 
8891 			if (dp == NULL)
8892 				return (EINVAL);
8893 			break;
8894 		}
8895 
8896 		default:
8897 			return (EINVAL);
8898 		}
8899 
8900 		if (size != 0 || desc->dtad_kind == DTRACEACT_SPECULATE) {
8901 			/*
8902 			 * If this is a data-storing action or a speculate,
8903 			 * we must be sure that there isn't a commit on the
8904 			 * action chain.
8905 			 */
8906 			dtrace_action_t *act = ecb->dte_action;
8907 
8908 			for (; act != NULL; act = act->dta_next) {
8909 				if (act->dta_kind == DTRACEACT_COMMIT)
8910 					return (EINVAL);
8911 			}
8912 		}
8913 
8914 		action = kmem_zalloc(sizeof (dtrace_action_t), KM_SLEEP);
8915 		action->dta_rec.dtrd_size = size;
8916 	}
8917 
8918 	action->dta_refcnt = 1;
8919 	rec = &action->dta_rec;
8920 	size = rec->dtrd_size;
8921 
8922 	for (mask = sizeof (uint64_t) - 1; size != 0 && mask > 0; mask >>= 1) {
8923 		if (!(size & mask)) {
8924 			align = mask + 1;
8925 			break;
8926 		}
8927 	}
8928 
8929 	action->dta_kind = desc->dtad_kind;
8930 
8931 	if ((action->dta_difo = dp) != NULL)
8932 		dtrace_difo_hold(dp);
8933 
8934 	rec->dtrd_action = action->dta_kind;
8935 	rec->dtrd_arg = arg;
8936 	rec->dtrd_uarg = desc->dtad_uarg;
8937 	rec->dtrd_alignment = (uint16_t)align;
8938 	rec->dtrd_format = format;
8939 
8940 	if ((last = ecb->dte_action_last) != NULL) {
8941 		ASSERT(ecb->dte_action != NULL);
8942 		action->dta_prev = last;
8943 		last->dta_next = action;
8944 	} else {
8945 		ASSERT(ecb->dte_action == NULL);
8946 		ecb->dte_action = action;
8947 	}
8948 
8949 	ecb->dte_action_last = action;
8950 
8951 	return (0);
8952 }
8953 
8954 static void
8955 dtrace_ecb_action_remove(dtrace_ecb_t *ecb)
8956 {
8957 	dtrace_action_t *act = ecb->dte_action, *next;
8958 	dtrace_vstate_t *vstate = &ecb->dte_state->dts_vstate;
8959 	dtrace_difo_t *dp;
8960 	uint16_t format;
8961 
8962 	if (act != NULL && act->dta_refcnt > 1) {
8963 		ASSERT(act->dta_next == NULL || act->dta_next->dta_refcnt == 1);
8964 		act->dta_refcnt--;
8965 	} else {
8966 		for (; act != NULL; act = next) {
8967 			next = act->dta_next;
8968 			ASSERT(next != NULL || act == ecb->dte_action_last);
8969 			ASSERT(act->dta_refcnt == 1);
8970 
8971 			if ((format = act->dta_rec.dtrd_format) != 0)
8972 				dtrace_format_remove(ecb->dte_state, format);
8973 
8974 			if ((dp = act->dta_difo) != NULL)
8975 				dtrace_difo_release(dp, vstate);
8976 
8977 			if (DTRACEACT_ISAGG(act->dta_kind)) {
8978 				dtrace_ecb_aggregation_destroy(ecb, act);
8979 			} else {
8980 				kmem_free(act, sizeof (dtrace_action_t));
8981 			}
8982 		}
8983 	}
8984 
8985 	ecb->dte_action = NULL;
8986 	ecb->dte_action_last = NULL;
8987 	ecb->dte_size = sizeof (dtrace_epid_t);
8988 }
8989 
8990 static void
8991 dtrace_ecb_disable(dtrace_ecb_t *ecb)
8992 {
8993 	/*
8994 	 * We disable the ECB by removing it from its probe.
8995 	 */
8996 	dtrace_ecb_t *pecb, *prev = NULL;
8997 	dtrace_probe_t *probe = ecb->dte_probe;
8998 
8999 	ASSERT(MUTEX_HELD(&dtrace_lock));
9000 
9001 	if (probe == NULL) {
9002 		/*
9003 		 * This is the NULL probe; there is nothing to disable.
9004 		 */
9005 		return;
9006 	}
9007 
9008 	for (pecb = probe->dtpr_ecb; pecb != NULL; pecb = pecb->dte_next) {
9009 		if (pecb == ecb)
9010 			break;
9011 		prev = pecb;
9012 	}
9013 
9014 	ASSERT(pecb != NULL);
9015 
9016 	if (prev == NULL) {
9017 		probe->dtpr_ecb = ecb->dte_next;
9018 	} else {
9019 		prev->dte_next = ecb->dte_next;
9020 	}
9021 
9022 	if (ecb == probe->dtpr_ecb_last) {
9023 		ASSERT(ecb->dte_next == NULL);
9024 		probe->dtpr_ecb_last = prev;
9025 	}
9026 
9027 	/*
9028 	 * The ECB has been disconnected from the probe; now sync to assure
9029 	 * that all CPUs have seen the change before returning.
9030 	 */
9031 	dtrace_sync();
9032 
9033 	if (probe->dtpr_ecb == NULL) {
9034 		/*
9035 		 * That was the last ECB on the probe; clear the predicate
9036 		 * cache ID for the probe, disable it and sync one more time
9037 		 * to assure that we'll never hit it again.
9038 		 */
9039 		dtrace_provider_t *prov = probe->dtpr_provider;
9040 
9041 		ASSERT(ecb->dte_next == NULL);
9042 		ASSERT(probe->dtpr_ecb_last == NULL);
9043 		probe->dtpr_predcache = DTRACE_CACHEIDNONE;
9044 		prov->dtpv_pops.dtps_disable(prov->dtpv_arg,
9045 		    probe->dtpr_id, probe->dtpr_arg);
9046 		dtrace_sync();
9047 	} else {
9048 		/*
9049 		 * There is at least one ECB remaining on the probe.  If there
9050 		 * is _exactly_ one, set the probe's predicate cache ID to be
9051 		 * the predicate cache ID of the remaining ECB.
9052 		 */
9053 		ASSERT(probe->dtpr_ecb_last != NULL);
9054 		ASSERT(probe->dtpr_predcache == DTRACE_CACHEIDNONE);
9055 
9056 		if (probe->dtpr_ecb == probe->dtpr_ecb_last) {
9057 			dtrace_predicate_t *p = probe->dtpr_ecb->dte_predicate;
9058 
9059 			ASSERT(probe->dtpr_ecb->dte_next == NULL);
9060 
9061 			if (p != NULL)
9062 				probe->dtpr_predcache = p->dtp_cacheid;
9063 		}
9064 
9065 		ecb->dte_next = NULL;
9066 	}
9067 }
9068 
9069 static void
9070 dtrace_ecb_destroy(dtrace_ecb_t *ecb)
9071 {
9072 	dtrace_state_t *state = ecb->dte_state;
9073 	dtrace_vstate_t *vstate = &state->dts_vstate;
9074 	dtrace_predicate_t *pred;
9075 	dtrace_epid_t epid = ecb->dte_epid;
9076 
9077 	ASSERT(MUTEX_HELD(&dtrace_lock));
9078 	ASSERT(ecb->dte_next == NULL);
9079 	ASSERT(ecb->dte_probe == NULL || ecb->dte_probe->dtpr_ecb != ecb);
9080 
9081 	if ((pred = ecb->dte_predicate) != NULL)
9082 		dtrace_predicate_release(pred, vstate);
9083 
9084 	dtrace_ecb_action_remove(ecb);
9085 
9086 	ASSERT(state->dts_ecbs[epid - 1] == ecb);
9087 	state->dts_ecbs[epid - 1] = NULL;
9088 
9089 	kmem_free(ecb, sizeof (dtrace_ecb_t));
9090 }
9091 
9092 static dtrace_ecb_t *
9093 dtrace_ecb_create(dtrace_state_t *state, dtrace_probe_t *probe,
9094     dtrace_enabling_t *enab)
9095 {
9096 	dtrace_ecb_t *ecb;
9097 	dtrace_predicate_t *pred;
9098 	dtrace_actdesc_t *act;
9099 	dtrace_provider_t *prov;
9100 	dtrace_ecbdesc_t *desc = enab->dten_current;
9101 
9102 	ASSERT(MUTEX_HELD(&dtrace_lock));
9103 	ASSERT(state != NULL);
9104 
9105 	ecb = dtrace_ecb_add(state, probe);
9106 	ecb->dte_uarg = desc->dted_uarg;
9107 
9108 	if ((pred = desc->dted_pred.dtpdd_predicate) != NULL) {
9109 		dtrace_predicate_hold(pred);
9110 		ecb->dte_predicate = pred;
9111 	}
9112 
9113 	if (probe != NULL) {
9114 		/*
9115 		 * If the provider shows more leg than the consumer is old
9116 		 * enough to see, we need to enable the appropriate implicit
9117 		 * predicate bits to prevent the ecb from activating at
9118 		 * revealing times.
9119 		 *
9120 		 * Providers specifying DTRACE_PRIV_USER at register time
9121 		 * are stating that they need the /proc-style privilege
9122 		 * model to be enforced, and this is what DTRACE_COND_OWNER
9123 		 * and DTRACE_COND_ZONEOWNER will then do at probe time.
9124 		 */
9125 		prov = probe->dtpr_provider;
9126 		if (!(state->dts_cred.dcr_visible & DTRACE_CRV_ALLPROC) &&
9127 		    (prov->dtpv_priv.dtpp_flags & DTRACE_PRIV_USER))
9128 			ecb->dte_cond |= DTRACE_COND_OWNER;
9129 
9130 		if (!(state->dts_cred.dcr_visible & DTRACE_CRV_ALLZONE) &&
9131 		    (prov->dtpv_priv.dtpp_flags & DTRACE_PRIV_USER))
9132 			ecb->dte_cond |= DTRACE_COND_ZONEOWNER;
9133 
9134 		/*
9135 		 * If the provider shows us kernel innards and the user
9136 		 * is lacking sufficient privilege, enable the
9137 		 * DTRACE_COND_USERMODE implicit predicate.
9138 		 */
9139 		if (!(state->dts_cred.dcr_visible & DTRACE_CRV_KERNEL) &&
9140 		    (prov->dtpv_priv.dtpp_flags & DTRACE_PRIV_KERNEL))
9141 			ecb->dte_cond |= DTRACE_COND_USERMODE;
9142 	}
9143 
9144 	if (dtrace_ecb_create_cache != NULL) {
9145 		/*
9146 		 * If we have a cached ecb, we'll use its action list instead
9147 		 * of creating our own (saving both time and space).
9148 		 */
9149 		dtrace_ecb_t *cached = dtrace_ecb_create_cache;
9150 		dtrace_action_t *act = cached->dte_action;
9151 
9152 		if (act != NULL) {
9153 			ASSERT(act->dta_refcnt > 0);
9154 			act->dta_refcnt++;
9155 			ecb->dte_action = act;
9156 			ecb->dte_action_last = cached->dte_action_last;
9157 			ecb->dte_needed = cached->dte_needed;
9158 			ecb->dte_size = cached->dte_size;
9159 			ecb->dte_alignment = cached->dte_alignment;
9160 		}
9161 
9162 		return (ecb);
9163 	}
9164 
9165 	for (act = desc->dted_action; act != NULL; act = act->dtad_next) {
9166 		if ((enab->dten_error = dtrace_ecb_action_add(ecb, act)) != 0) {
9167 			dtrace_ecb_destroy(ecb);
9168 			return (NULL);
9169 		}
9170 	}
9171 
9172 	dtrace_ecb_resize(ecb);
9173 
9174 	return (dtrace_ecb_create_cache = ecb);
9175 }
9176 
9177 static int
9178 dtrace_ecb_create_enable(dtrace_probe_t *probe, void *arg)
9179 {
9180 	dtrace_ecb_t *ecb;
9181 	dtrace_enabling_t *enab = arg;
9182 	dtrace_state_t *state = enab->dten_vstate->dtvs_state;
9183 
9184 	ASSERT(state != NULL);
9185 
9186 	if (probe != NULL && probe->dtpr_gen < enab->dten_probegen) {
9187 		/*
9188 		 * This probe was created in a generation for which this
9189 		 * enabling has previously created ECBs; we don't want to
9190 		 * enable it again, so just kick out.
9191 		 */
9192 		return (DTRACE_MATCH_NEXT);
9193 	}
9194 
9195 	if ((ecb = dtrace_ecb_create(state, probe, enab)) == NULL)
9196 		return (DTRACE_MATCH_DONE);
9197 
9198 	dtrace_ecb_enable(ecb);
9199 	return (DTRACE_MATCH_NEXT);
9200 }
9201 
9202 static dtrace_ecb_t *
9203 dtrace_epid2ecb(dtrace_state_t *state, dtrace_epid_t id)
9204 {
9205 	dtrace_ecb_t *ecb;
9206 
9207 	ASSERT(MUTEX_HELD(&dtrace_lock));
9208 
9209 	if (id == 0 || id > state->dts_necbs)
9210 		return (NULL);
9211 
9212 	ASSERT(state->dts_necbs > 0 && state->dts_ecbs != NULL);
9213 	ASSERT((ecb = state->dts_ecbs[id - 1]) == NULL || ecb->dte_epid == id);
9214 
9215 	return (state->dts_ecbs[id - 1]);
9216 }
9217 
9218 static dtrace_aggregation_t *
9219 dtrace_aggid2agg(dtrace_state_t *state, dtrace_aggid_t id)
9220 {
9221 	dtrace_aggregation_t *agg;
9222 
9223 	ASSERT(MUTEX_HELD(&dtrace_lock));
9224 
9225 	if (id == 0 || id > state->dts_naggregations)
9226 		return (NULL);
9227 
9228 	ASSERT(state->dts_naggregations > 0 && state->dts_aggregations != NULL);
9229 	ASSERT((agg = state->dts_aggregations[id - 1]) == NULL ||
9230 	    agg->dtag_id == id);
9231 
9232 	return (state->dts_aggregations[id - 1]);
9233 }
9234 
9235 /*
9236  * DTrace Buffer Functions
9237  *
9238  * The following functions manipulate DTrace buffers.  Most of these functions
9239  * are called in the context of establishing or processing consumer state;
9240  * exceptions are explicitly noted.
9241  */
9242 
9243 /*
9244  * Note:  called from cross call context.  This function switches the two
9245  * buffers on a given CPU.  The atomicity of this operation is assured by
9246  * disabling interrupts while the actual switch takes place; the disabling of
9247  * interrupts serializes the execution with any execution of dtrace_probe() on
9248  * the same CPU.
9249  */
9250 static void
9251 dtrace_buffer_switch(dtrace_buffer_t *buf)
9252 {
9253 	caddr_t tomax = buf->dtb_tomax;
9254 	caddr_t xamot = buf->dtb_xamot;
9255 	dtrace_icookie_t cookie;
9256 
9257 	ASSERT(!(buf->dtb_flags & DTRACEBUF_NOSWITCH));
9258 	ASSERT(!(buf->dtb_flags & DTRACEBUF_RING));
9259 
9260 	cookie = dtrace_interrupt_disable();
9261 	buf->dtb_tomax = xamot;
9262 	buf->dtb_xamot = tomax;
9263 	buf->dtb_xamot_drops = buf->dtb_drops;
9264 	buf->dtb_xamot_offset = buf->dtb_offset;
9265 	buf->dtb_xamot_errors = buf->dtb_errors;
9266 	buf->dtb_xamot_flags = buf->dtb_flags;
9267 	buf->dtb_offset = 0;
9268 	buf->dtb_drops = 0;
9269 	buf->dtb_errors = 0;
9270 	buf->dtb_flags &= ~(DTRACEBUF_ERROR | DTRACEBUF_DROPPED);
9271 	dtrace_interrupt_enable(cookie);
9272 }
9273 
9274 /*
9275  * Note:  called from cross call context.  This function activates a buffer
9276  * on a CPU.  As with dtrace_buffer_switch(), the atomicity of the operation
9277  * is guaranteed by the disabling of interrupts.
9278  */
9279 static void
9280 dtrace_buffer_activate(dtrace_state_t *state)
9281 {
9282 	dtrace_buffer_t *buf;
9283 	dtrace_icookie_t cookie = dtrace_interrupt_disable();
9284 
9285 	buf = &state->dts_buffer[CPU->cpu_id];
9286 
9287 	if (buf->dtb_tomax != NULL) {
9288 		/*
9289 		 * We might like to assert that the buffer is marked inactive,
9290 		 * but this isn't necessarily true:  the buffer for the CPU
9291 		 * that processes the BEGIN probe has its buffer activated
9292 		 * manually.  In this case, we take the (harmless) action
9293 		 * re-clearing the bit INACTIVE bit.
9294 		 */
9295 		buf->dtb_flags &= ~DTRACEBUF_INACTIVE;
9296 	}
9297 
9298 	dtrace_interrupt_enable(cookie);
9299 }
9300 
9301 static int
9302 dtrace_buffer_alloc(dtrace_buffer_t *bufs, size_t size, int flags,
9303     processorid_t cpu)
9304 {
9305 	cpu_t *cp;
9306 	dtrace_buffer_t *buf;
9307 
9308 	ASSERT(MUTEX_HELD(&cpu_lock));
9309 	ASSERT(MUTEX_HELD(&dtrace_lock));
9310 
9311 	if (size > dtrace_nonroot_maxsize &&
9312 	    !PRIV_POLICY_CHOICE(CRED(), PRIV_ALL, B_FALSE))
9313 		return (EFBIG);
9314 
9315 	cp = cpu_list;
9316 
9317 	do {
9318 		if (cpu != DTRACE_CPUALL && cpu != cp->cpu_id)
9319 			continue;
9320 
9321 		buf = &bufs[cp->cpu_id];
9322 
9323 		/*
9324 		 * If there is already a buffer allocated for this CPU, it
9325 		 * is only possible that this is a DR event.  In this case,
9326 		 * the buffer size must match our specified size.
9327 		 */
9328 		if (buf->dtb_tomax != NULL) {
9329 			ASSERT(buf->dtb_size == size);
9330 			continue;
9331 		}
9332 
9333 		ASSERT(buf->dtb_xamot == NULL);
9334 
9335 		if ((buf->dtb_tomax = kmem_zalloc(size, KM_NOSLEEP)) == NULL)
9336 			goto err;
9337 
9338 		buf->dtb_size = size;
9339 		buf->dtb_flags = flags;
9340 		buf->dtb_offset = 0;
9341 		buf->dtb_drops = 0;
9342 
9343 		if (flags & DTRACEBUF_NOSWITCH)
9344 			continue;
9345 
9346 		if ((buf->dtb_xamot = kmem_zalloc(size, KM_NOSLEEP)) == NULL)
9347 			goto err;
9348 	} while ((cp = cp->cpu_next) != cpu_list);
9349 
9350 	return (0);
9351 
9352 err:
9353 	cp = cpu_list;
9354 
9355 	do {
9356 		if (cpu != DTRACE_CPUALL && cpu != cp->cpu_id)
9357 			continue;
9358 
9359 		buf = &bufs[cp->cpu_id];
9360 
9361 		if (buf->dtb_xamot != NULL) {
9362 			ASSERT(buf->dtb_tomax != NULL);
9363 			ASSERT(buf->dtb_size == size);
9364 			kmem_free(buf->dtb_xamot, size);
9365 		}
9366 
9367 		if (buf->dtb_tomax != NULL) {
9368 			ASSERT(buf->dtb_size == size);
9369 			kmem_free(buf->dtb_tomax, size);
9370 		}
9371 
9372 		buf->dtb_tomax = NULL;
9373 		buf->dtb_xamot = NULL;
9374 		buf->dtb_size = 0;
9375 	} while ((cp = cp->cpu_next) != cpu_list);
9376 
9377 	return (ENOMEM);
9378 }
9379 
9380 /*
9381  * Note:  called from probe context.  This function just increments the drop
9382  * count on a buffer.  It has been made a function to allow for the
9383  * possibility of understanding the source of mysterious drop counts.  (A
9384  * problem for which one may be particularly disappointed that DTrace cannot
9385  * be used to understand DTrace.)
9386  */
9387 static void
9388 dtrace_buffer_drop(dtrace_buffer_t *buf)
9389 {
9390 	buf->dtb_drops++;
9391 }
9392 
9393 /*
9394  * Note:  called from probe context.  This function is called to reserve space
9395  * in a buffer.  If mstate is non-NULL, sets the scratch base and size in the
9396  * mstate.  Returns the new offset in the buffer, or a negative value if an
9397  * error has occurred.
9398  */
9399 static intptr_t
9400 dtrace_buffer_reserve(dtrace_buffer_t *buf, size_t needed, size_t align,
9401     dtrace_state_t *state, dtrace_mstate_t *mstate)
9402 {
9403 	intptr_t offs = buf->dtb_offset, soffs;
9404 	intptr_t woffs;
9405 	caddr_t tomax;
9406 	size_t total;
9407 
9408 	if (buf->dtb_flags & DTRACEBUF_INACTIVE)
9409 		return (-1);
9410 
9411 	if ((tomax = buf->dtb_tomax) == NULL) {
9412 		dtrace_buffer_drop(buf);
9413 		return (-1);
9414 	}
9415 
9416 	if (!(buf->dtb_flags & (DTRACEBUF_RING | DTRACEBUF_FILL))) {
9417 		while (offs & (align - 1)) {
9418 			/*
9419 			 * Assert that our alignment is off by a number which
9420 			 * is itself sizeof (uint32_t) aligned.
9421 			 */
9422 			ASSERT(!((align - (offs & (align - 1))) &
9423 			    (sizeof (uint32_t) - 1)));
9424 			DTRACE_STORE(uint32_t, tomax, offs, DTRACE_EPIDNONE);
9425 			offs += sizeof (uint32_t);
9426 		}
9427 
9428 		if ((soffs = offs + needed) > buf->dtb_size) {
9429 			dtrace_buffer_drop(buf);
9430 			return (-1);
9431 		}
9432 
9433 		if (mstate == NULL)
9434 			return (offs);
9435 
9436 		mstate->dtms_scratch_base = (uintptr_t)tomax + soffs;
9437 		mstate->dtms_scratch_size = buf->dtb_size - soffs;
9438 		mstate->dtms_scratch_ptr = mstate->dtms_scratch_base;
9439 
9440 		return (offs);
9441 	}
9442 
9443 	if (buf->dtb_flags & DTRACEBUF_FILL) {
9444 		if (state->dts_activity != DTRACE_ACTIVITY_COOLDOWN &&
9445 		    (buf->dtb_flags & DTRACEBUF_FULL))
9446 			return (-1);
9447 		goto out;
9448 	}
9449 
9450 	total = needed + (offs & (align - 1));
9451 
9452 	/*
9453 	 * For a ring buffer, life is quite a bit more complicated.  Before
9454 	 * we can store any padding, we need to adjust our wrapping offset.
9455 	 * (If we've never before wrapped or we're not about to, no adjustment
9456 	 * is required.)
9457 	 */
9458 	if ((buf->dtb_flags & DTRACEBUF_WRAPPED) ||
9459 	    offs + total > buf->dtb_size) {
9460 		woffs = buf->dtb_xamot_offset;
9461 
9462 		if (offs + total > buf->dtb_size) {
9463 			/*
9464 			 * We can't fit in the end of the buffer.  First, a
9465 			 * sanity check that we can fit in the buffer at all.
9466 			 */
9467 			if (total > buf->dtb_size) {
9468 				dtrace_buffer_drop(buf);
9469 				return (-1);
9470 			}
9471 
9472 			/*
9473 			 * We're going to be storing at the top of the buffer,
9474 			 * so now we need to deal with the wrapped offset.  We
9475 			 * only reset our wrapped offset to 0 if it is
9476 			 * currently greater than the current offset.  If it
9477 			 * is less than the current offset, it is because a
9478 			 * previous allocation induced a wrap -- but the
9479 			 * allocation didn't subsequently take the space due
9480 			 * to an error or false predicate evaluation.  In this
9481 			 * case, we'll just leave the wrapped offset alone: if
9482 			 * the wrapped offset hasn't been advanced far enough
9483 			 * for this allocation, it will be adjusted in the
9484 			 * lower loop.
9485 			 */
9486 			if (buf->dtb_flags & DTRACEBUF_WRAPPED) {
9487 				if (woffs >= offs)
9488 					woffs = 0;
9489 			} else {
9490 				woffs = 0;
9491 			}
9492 
9493 			/*
9494 			 * Now we know that we're going to be storing to the
9495 			 * top of the buffer and that there is room for us
9496 			 * there.  We need to clear the buffer from the current
9497 			 * offset to the end (there may be old gunk there).
9498 			 */
9499 			while (offs < buf->dtb_size)
9500 				tomax[offs++] = 0;
9501 
9502 			/*
9503 			 * We need to set our offset to zero.  And because we
9504 			 * are wrapping, we need to set the bit indicating as
9505 			 * much.  We can also adjust our needed space back
9506 			 * down to the space required by the ECB -- we know
9507 			 * that the top of the buffer is aligned.
9508 			 */
9509 			offs = 0;
9510 			total = needed;
9511 			buf->dtb_flags |= DTRACEBUF_WRAPPED;
9512 		} else {
9513 			/*
9514 			 * There is room for us in the buffer, so we simply
9515 			 * need to check the wrapped offset.
9516 			 */
9517 			if (woffs < offs) {
9518 				/*
9519 				 * The wrapped offset is less than the offset.
9520 				 * This can happen if we allocated buffer space
9521 				 * that induced a wrap, but then we didn't
9522 				 * subsequently take the space due to an error
9523 				 * or false predicate evaluation.  This is
9524 				 * okay; we know that _this_ allocation isn't
9525 				 * going to induce a wrap.  We still can't
9526 				 * reset the wrapped offset to be zero,
9527 				 * however: the space may have been trashed in
9528 				 * the previous failed probe attempt.  But at
9529 				 * least the wrapped offset doesn't need to
9530 				 * be adjusted at all...
9531 				 */
9532 				goto out;
9533 			}
9534 		}
9535 
9536 		while (offs + total > woffs) {
9537 			dtrace_epid_t epid = *(uint32_t *)(tomax + woffs);
9538 			size_t size;
9539 
9540 			if (epid == DTRACE_EPIDNONE) {
9541 				size = sizeof (uint32_t);
9542 			} else {
9543 				ASSERT(epid <= state->dts_necbs);
9544 				ASSERT(state->dts_ecbs[epid - 1] != NULL);
9545 
9546 				size = state->dts_ecbs[epid - 1]->dte_size;
9547 			}
9548 
9549 			ASSERT(woffs + size <= buf->dtb_size);
9550 			ASSERT(size != 0);
9551 
9552 			if (woffs + size == buf->dtb_size) {
9553 				/*
9554 				 * We've reached the end of the buffer; we want
9555 				 * to set the wrapped offset to 0 and break
9556 				 * out.  However, if the offs is 0, then we're
9557 				 * in a strange edge-condition:  the amount of
9558 				 * space that we want to reserve plus the size
9559 				 * of the record that we're overwriting is
9560 				 * greater than the size of the buffer.  This
9561 				 * is problematic because if we reserve the
9562 				 * space but subsequently don't consume it (due
9563 				 * to a failed predicate or error) the wrapped
9564 				 * offset will be 0 -- yet the EPID at offset 0
9565 				 * will not be committed.  This situation is
9566 				 * relatively easy to deal with:  if we're in
9567 				 * this case, the buffer is indistinguishable
9568 				 * from one that hasn't wrapped; we need only
9569 				 * finish the job by clearing the wrapped bit,
9570 				 * explicitly setting the offset to be 0, and
9571 				 * zero'ing out the old data in the buffer.
9572 				 */
9573 				if (offs == 0) {
9574 					buf->dtb_flags &= ~DTRACEBUF_WRAPPED;
9575 					buf->dtb_offset = 0;
9576 					woffs = total;
9577 
9578 					while (woffs < buf->dtb_size)
9579 						tomax[woffs++] = 0;
9580 				}
9581 
9582 				woffs = 0;
9583 				break;
9584 			}
9585 
9586 			woffs += size;
9587 		}
9588 
9589 		/*
9590 		 * We have a wrapped offset.  It may be that the wrapped offset
9591 		 * has become zero -- that's okay.
9592 		 */
9593 		buf->dtb_xamot_offset = woffs;
9594 	}
9595 
9596 out:
9597 	/*
9598 	 * Now we can plow the buffer with any necessary padding.
9599 	 */
9600 	while (offs & (align - 1)) {
9601 		/*
9602 		 * Assert that our alignment is off by a number which
9603 		 * is itself sizeof (uint32_t) aligned.
9604 		 */
9605 		ASSERT(!((align - (offs & (align - 1))) &
9606 		    (sizeof (uint32_t) - 1)));
9607 		DTRACE_STORE(uint32_t, tomax, offs, DTRACE_EPIDNONE);
9608 		offs += sizeof (uint32_t);
9609 	}
9610 
9611 	if (buf->dtb_flags & DTRACEBUF_FILL) {
9612 		if (offs + needed > buf->dtb_size - state->dts_reserve) {
9613 			buf->dtb_flags |= DTRACEBUF_FULL;
9614 			return (-1);
9615 		}
9616 	}
9617 
9618 	if (mstate == NULL)
9619 		return (offs);
9620 
9621 	/*
9622 	 * For ring buffers and fill buffers, the scratch space is always
9623 	 * the inactive buffer.
9624 	 */
9625 	mstate->dtms_scratch_base = (uintptr_t)buf->dtb_xamot;
9626 	mstate->dtms_scratch_size = buf->dtb_size;
9627 	mstate->dtms_scratch_ptr = mstate->dtms_scratch_base;
9628 
9629 	return (offs);
9630 }
9631 
9632 static void
9633 dtrace_buffer_polish(dtrace_buffer_t *buf)
9634 {
9635 	ASSERT(buf->dtb_flags & DTRACEBUF_RING);
9636 	ASSERT(MUTEX_HELD(&dtrace_lock));
9637 
9638 	if (!(buf->dtb_flags & DTRACEBUF_WRAPPED))
9639 		return;
9640 
9641 	/*
9642 	 * We need to polish the ring buffer.  There are three cases:
9643 	 *
9644 	 * - The first (and presumably most common) is that there is no gap
9645 	 *   between the buffer offset and the wrapped offset.  In this case,
9646 	 *   there is nothing in the buffer that isn't valid data; we can
9647 	 *   mark the buffer as polished and return.
9648 	 *
9649 	 * - The second (less common than the first but still more common
9650 	 *   than the third) is that there is a gap between the buffer offset
9651 	 *   and the wrapped offset, and the wrapped offset is larger than the
9652 	 *   buffer offset.  This can happen because of an alignment issue, or
9653 	 *   can happen because of a call to dtrace_buffer_reserve() that
9654 	 *   didn't subsequently consume the buffer space.  In this case,
9655 	 *   we need to zero the data from the buffer offset to the wrapped
9656 	 *   offset.
9657 	 *
9658 	 * - The third (and least common) is that there is a gap between the
9659 	 *   buffer offset and the wrapped offset, but the wrapped offset is
9660 	 *   _less_ than the buffer offset.  This can only happen because a
9661 	 *   call to dtrace_buffer_reserve() induced a wrap, but the space
9662 	 *   was not subsequently consumed.  In this case, we need to zero the
9663 	 *   space from the offset to the end of the buffer _and_ from the
9664 	 *   top of the buffer to the wrapped offset.
9665 	 */
9666 	if (buf->dtb_offset < buf->dtb_xamot_offset) {
9667 		bzero(buf->dtb_tomax + buf->dtb_offset,
9668 		    buf->dtb_xamot_offset - buf->dtb_offset);
9669 	}
9670 
9671 	if (buf->dtb_offset > buf->dtb_xamot_offset) {
9672 		bzero(buf->dtb_tomax + buf->dtb_offset,
9673 		    buf->dtb_size - buf->dtb_offset);
9674 		bzero(buf->dtb_tomax, buf->dtb_xamot_offset);
9675 	}
9676 }
9677 
9678 static void
9679 dtrace_buffer_free(dtrace_buffer_t *bufs)
9680 {
9681 	int i;
9682 
9683 	for (i = 0; i < NCPU; i++) {
9684 		dtrace_buffer_t *buf = &bufs[i];
9685 
9686 		if (buf->dtb_tomax == NULL) {
9687 			ASSERT(buf->dtb_xamot == NULL);
9688 			ASSERT(buf->dtb_size == 0);
9689 			continue;
9690 		}
9691 
9692 		if (buf->dtb_xamot != NULL) {
9693 			ASSERT(!(buf->dtb_flags & DTRACEBUF_NOSWITCH));
9694 			kmem_free(buf->dtb_xamot, buf->dtb_size);
9695 		}
9696 
9697 		kmem_free(buf->dtb_tomax, buf->dtb_size);
9698 		buf->dtb_size = 0;
9699 		buf->dtb_tomax = NULL;
9700 		buf->dtb_xamot = NULL;
9701 	}
9702 }
9703 
9704 /*
9705  * DTrace Enabling Functions
9706  */
9707 static dtrace_enabling_t *
9708 dtrace_enabling_create(dtrace_vstate_t *vstate)
9709 {
9710 	dtrace_enabling_t *enab;
9711 
9712 	enab = kmem_zalloc(sizeof (dtrace_enabling_t), KM_SLEEP);
9713 	enab->dten_vstate = vstate;
9714 
9715 	return (enab);
9716 }
9717 
9718 static void
9719 dtrace_enabling_add(dtrace_enabling_t *enab, dtrace_ecbdesc_t *ecb)
9720 {
9721 	dtrace_ecbdesc_t **ndesc;
9722 	size_t osize, nsize;
9723 
9724 	/*
9725 	 * We can't add to enablings after we've enabled them, or after we've
9726 	 * retained them.
9727 	 */
9728 	ASSERT(enab->dten_probegen == 0);
9729 	ASSERT(enab->dten_next == NULL && enab->dten_prev == NULL);
9730 
9731 	if (enab->dten_ndesc < enab->dten_maxdesc) {
9732 		enab->dten_desc[enab->dten_ndesc++] = ecb;
9733 		return;
9734 	}
9735 
9736 	osize = enab->dten_maxdesc * sizeof (dtrace_enabling_t *);
9737 
9738 	if (enab->dten_maxdesc == 0) {
9739 		enab->dten_maxdesc = 1;
9740 	} else {
9741 		enab->dten_maxdesc <<= 1;
9742 	}
9743 
9744 	ASSERT(enab->dten_ndesc < enab->dten_maxdesc);
9745 
9746 	nsize = enab->dten_maxdesc * sizeof (dtrace_enabling_t *);
9747 	ndesc = kmem_zalloc(nsize, KM_SLEEP);
9748 	bcopy(enab->dten_desc, ndesc, osize);
9749 	kmem_free(enab->dten_desc, osize);
9750 
9751 	enab->dten_desc = ndesc;
9752 	enab->dten_desc[enab->dten_ndesc++] = ecb;
9753 }
9754 
9755 static void
9756 dtrace_enabling_addlike(dtrace_enabling_t *enab, dtrace_ecbdesc_t *ecb,
9757     dtrace_probedesc_t *pd)
9758 {
9759 	dtrace_ecbdesc_t *new;
9760 	dtrace_predicate_t *pred;
9761 	dtrace_actdesc_t *act;
9762 
9763 	/*
9764 	 * We're going to create a new ECB description that matches the
9765 	 * specified ECB in every way, but has the specified probe description.
9766 	 */
9767 	new = kmem_zalloc(sizeof (dtrace_ecbdesc_t), KM_SLEEP);
9768 
9769 	if ((pred = ecb->dted_pred.dtpdd_predicate) != NULL)
9770 		dtrace_predicate_hold(pred);
9771 
9772 	for (act = ecb->dted_action; act != NULL; act = act->dtad_next)
9773 		dtrace_actdesc_hold(act);
9774 
9775 	new->dted_action = ecb->dted_action;
9776 	new->dted_pred = ecb->dted_pred;
9777 	new->dted_probe = *pd;
9778 	new->dted_uarg = ecb->dted_uarg;
9779 
9780 	dtrace_enabling_add(enab, new);
9781 }
9782 
9783 static void
9784 dtrace_enabling_dump(dtrace_enabling_t *enab)
9785 {
9786 	int i;
9787 
9788 	for (i = 0; i < enab->dten_ndesc; i++) {
9789 		dtrace_probedesc_t *desc = &enab->dten_desc[i]->dted_probe;
9790 
9791 		cmn_err(CE_NOTE, "enabling probe %d (%s:%s:%s:%s)", i,
9792 		    desc->dtpd_provider, desc->dtpd_mod,
9793 		    desc->dtpd_func, desc->dtpd_name);
9794 	}
9795 }
9796 
9797 static void
9798 dtrace_enabling_destroy(dtrace_enabling_t *enab)
9799 {
9800 	int i;
9801 	dtrace_ecbdesc_t *ep;
9802 	dtrace_vstate_t *vstate = enab->dten_vstate;
9803 
9804 	ASSERT(MUTEX_HELD(&dtrace_lock));
9805 
9806 	for (i = 0; i < enab->dten_ndesc; i++) {
9807 		dtrace_actdesc_t *act, *next;
9808 		dtrace_predicate_t *pred;
9809 
9810 		ep = enab->dten_desc[i];
9811 
9812 		if ((pred = ep->dted_pred.dtpdd_predicate) != NULL)
9813 			dtrace_predicate_release(pred, vstate);
9814 
9815 		for (act = ep->dted_action; act != NULL; act = next) {
9816 			next = act->dtad_next;
9817 			dtrace_actdesc_release(act, vstate);
9818 		}
9819 
9820 		kmem_free(ep, sizeof (dtrace_ecbdesc_t));
9821 	}
9822 
9823 	kmem_free(enab->dten_desc,
9824 	    enab->dten_maxdesc * sizeof (dtrace_enabling_t *));
9825 
9826 	/*
9827 	 * If this was a retained enabling, decrement the dts_nretained count
9828 	 * and take it off of the dtrace_retained list.
9829 	 */
9830 	if (enab->dten_prev != NULL || enab->dten_next != NULL ||
9831 	    dtrace_retained == enab) {
9832 		ASSERT(enab->dten_vstate->dtvs_state != NULL);
9833 		ASSERT(enab->dten_vstate->dtvs_state->dts_nretained > 0);
9834 		enab->dten_vstate->dtvs_state->dts_nretained--;
9835 	}
9836 
9837 	if (enab->dten_prev == NULL) {
9838 		if (dtrace_retained == enab) {
9839 			dtrace_retained = enab->dten_next;
9840 
9841 			if (dtrace_retained != NULL)
9842 				dtrace_retained->dten_prev = NULL;
9843 		}
9844 	} else {
9845 		ASSERT(enab != dtrace_retained);
9846 		ASSERT(dtrace_retained != NULL);
9847 		enab->dten_prev->dten_next = enab->dten_next;
9848 	}
9849 
9850 	if (enab->dten_next != NULL) {
9851 		ASSERT(dtrace_retained != NULL);
9852 		enab->dten_next->dten_prev = enab->dten_prev;
9853 	}
9854 
9855 	kmem_free(enab, sizeof (dtrace_enabling_t));
9856 }
9857 
9858 static int
9859 dtrace_enabling_retain(dtrace_enabling_t *enab)
9860 {
9861 	dtrace_state_t *state;
9862 
9863 	ASSERT(MUTEX_HELD(&dtrace_lock));
9864 	ASSERT(enab->dten_next == NULL && enab->dten_prev == NULL);
9865 	ASSERT(enab->dten_vstate != NULL);
9866 
9867 	state = enab->dten_vstate->dtvs_state;
9868 	ASSERT(state != NULL);
9869 
9870 	/*
9871 	 * We only allow each state to retain dtrace_retain_max enablings.
9872 	 */
9873 	if (state->dts_nretained >= dtrace_retain_max)
9874 		return (ENOSPC);
9875 
9876 	state->dts_nretained++;
9877 
9878 	if (dtrace_retained == NULL) {
9879 		dtrace_retained = enab;
9880 		return (0);
9881 	}
9882 
9883 	enab->dten_next = dtrace_retained;
9884 	dtrace_retained->dten_prev = enab;
9885 	dtrace_retained = enab;
9886 
9887 	return (0);
9888 }
9889 
9890 static int
9891 dtrace_enabling_replicate(dtrace_state_t *state, dtrace_probedesc_t *match,
9892     dtrace_probedesc_t *create)
9893 {
9894 	dtrace_enabling_t *new, *enab;
9895 	int found = 0, err = ENOENT;
9896 
9897 	ASSERT(MUTEX_HELD(&dtrace_lock));
9898 	ASSERT(strlen(match->dtpd_provider) < DTRACE_PROVNAMELEN);
9899 	ASSERT(strlen(match->dtpd_mod) < DTRACE_MODNAMELEN);
9900 	ASSERT(strlen(match->dtpd_func) < DTRACE_FUNCNAMELEN);
9901 	ASSERT(strlen(match->dtpd_name) < DTRACE_NAMELEN);
9902 
9903 	new = dtrace_enabling_create(&state->dts_vstate);
9904 
9905 	/*
9906 	 * Iterate over all retained enablings, looking for enablings that
9907 	 * match the specified state.
9908 	 */
9909 	for (enab = dtrace_retained; enab != NULL; enab = enab->dten_next) {
9910 		int i;
9911 
9912 		/*
9913 		 * dtvs_state can only be NULL for helper enablings -- and
9914 		 * helper enablings can't be retained.
9915 		 */
9916 		ASSERT(enab->dten_vstate->dtvs_state != NULL);
9917 
9918 		if (enab->dten_vstate->dtvs_state != state)
9919 			continue;
9920 
9921 		/*
9922 		 * Now iterate over each probe description; we're looking for
9923 		 * an exact match to the specified probe description.
9924 		 */
9925 		for (i = 0; i < enab->dten_ndesc; i++) {
9926 			dtrace_ecbdesc_t *ep = enab->dten_desc[i];
9927 			dtrace_probedesc_t *pd = &ep->dted_probe;
9928 
9929 			if (strcmp(pd->dtpd_provider, match->dtpd_provider))
9930 				continue;
9931 
9932 			if (strcmp(pd->dtpd_mod, match->dtpd_mod))
9933 				continue;
9934 
9935 			if (strcmp(pd->dtpd_func, match->dtpd_func))
9936 				continue;
9937 
9938 			if (strcmp(pd->dtpd_name, match->dtpd_name))
9939 				continue;
9940 
9941 			/*
9942 			 * We have a winning probe!  Add it to our growing
9943 			 * enabling.
9944 			 */
9945 			found = 1;
9946 			dtrace_enabling_addlike(new, ep, create);
9947 		}
9948 	}
9949 
9950 	if (!found || (err = dtrace_enabling_retain(new)) != 0) {
9951 		dtrace_enabling_destroy(new);
9952 		return (err);
9953 	}
9954 
9955 	return (0);
9956 }
9957 
9958 static void
9959 dtrace_enabling_retract(dtrace_state_t *state)
9960 {
9961 	dtrace_enabling_t *enab, *next;
9962 
9963 	ASSERT(MUTEX_HELD(&dtrace_lock));
9964 
9965 	/*
9966 	 * Iterate over all retained enablings, destroy the enablings retained
9967 	 * for the specified state.
9968 	 */
9969 	for (enab = dtrace_retained; enab != NULL; enab = next) {
9970 		next = enab->dten_next;
9971 
9972 		/*
9973 		 * dtvs_state can only be NULL for helper enablings -- and
9974 		 * helper enablings can't be retained.
9975 		 */
9976 		ASSERT(enab->dten_vstate->dtvs_state != NULL);
9977 
9978 		if (enab->dten_vstate->dtvs_state == state) {
9979 			ASSERT(state->dts_nretained > 0);
9980 			dtrace_enabling_destroy(enab);
9981 		}
9982 	}
9983 
9984 	ASSERT(state->dts_nretained == 0);
9985 }
9986 
9987 static int
9988 dtrace_enabling_match(dtrace_enabling_t *enab, int *nmatched)
9989 {
9990 	int i = 0;
9991 	int matched = 0;
9992 
9993 	ASSERT(MUTEX_HELD(&cpu_lock));
9994 	ASSERT(MUTEX_HELD(&dtrace_lock));
9995 
9996 	for (i = 0; i < enab->dten_ndesc; i++) {
9997 		dtrace_ecbdesc_t *ep = enab->dten_desc[i];
9998 
9999 		enab->dten_current = ep;
10000 		enab->dten_error = 0;
10001 
10002 		matched += dtrace_probe_enable(&ep->dted_probe, enab);
10003 
10004 		if (enab->dten_error != 0) {
10005 			/*
10006 			 * If we get an error half-way through enabling the
10007 			 * probes, we kick out -- perhaps with some number of
10008 			 * them enabled.  Leaving enabled probes enabled may
10009 			 * be slightly confusing for user-level, but we expect
10010 			 * that no one will attempt to actually drive on in
10011 			 * the face of such errors.  If this is an anonymous
10012 			 * enabling (indicated with a NULL nmatched pointer),
10013 			 * we cmn_err() a message.  We aren't expecting to
10014 			 * get such an error -- such as it can exist at all,
10015 			 * it would be a result of corrupted DOF in the driver
10016 			 * properties.
10017 			 */
10018 			if (nmatched == NULL) {
10019 				cmn_err(CE_WARN, "dtrace_enabling_match() "
10020 				    "error on %p: %d", (void *)ep,
10021 				    enab->dten_error);
10022 			}
10023 
10024 			return (enab->dten_error);
10025 		}
10026 	}
10027 
10028 	enab->dten_probegen = dtrace_probegen;
10029 	if (nmatched != NULL)
10030 		*nmatched = matched;
10031 
10032 	return (0);
10033 }
10034 
10035 static void
10036 dtrace_enabling_matchall(void)
10037 {
10038 	dtrace_enabling_t *enab;
10039 
10040 	mutex_enter(&cpu_lock);
10041 	mutex_enter(&dtrace_lock);
10042 
10043 	/*
10044 	 * Because we can be called after dtrace_detach() has been called, we
10045 	 * cannot assert that there are retained enablings.  We can safely
10046 	 * load from dtrace_retained, however:  the taskq_destroy() at the
10047 	 * end of dtrace_detach() will block pending our completion.
10048 	 */
10049 	for (enab = dtrace_retained; enab != NULL; enab = enab->dten_next)
10050 		(void) dtrace_enabling_match(enab, NULL);
10051 
10052 	mutex_exit(&dtrace_lock);
10053 	mutex_exit(&cpu_lock);
10054 }
10055 
10056 static int
10057 dtrace_enabling_matchstate(dtrace_state_t *state, int *nmatched)
10058 {
10059 	dtrace_enabling_t *enab;
10060 	int matched, total = 0, err;
10061 
10062 	ASSERT(MUTEX_HELD(&cpu_lock));
10063 	ASSERT(MUTEX_HELD(&dtrace_lock));
10064 
10065 	for (enab = dtrace_retained; enab != NULL; enab = enab->dten_next) {
10066 		ASSERT(enab->dten_vstate->dtvs_state != NULL);
10067 
10068 		if (enab->dten_vstate->dtvs_state != state)
10069 			continue;
10070 
10071 		if ((err = dtrace_enabling_match(enab, &matched)) != 0)
10072 			return (err);
10073 
10074 		total += matched;
10075 	}
10076 
10077 	if (nmatched != NULL)
10078 		*nmatched = total;
10079 
10080 	return (0);
10081 }
10082 
10083 /*
10084  * If an enabling is to be enabled without having matched probes (that is, if
10085  * dtrace_state_go() is to be called on the underlying dtrace_state_t), the
10086  * enabling must be _primed_ by creating an ECB for every ECB description.
10087  * This must be done to assure that we know the number of speculations, the
10088  * number of aggregations, the minimum buffer size needed, etc. before we
10089  * transition out of DTRACE_ACTIVITY_INACTIVE.  To do this without actually
10090  * enabling any probes, we create ECBs for every ECB decription, but with a
10091  * NULL probe -- which is exactly what this function does.
10092  */
10093 static void
10094 dtrace_enabling_prime(dtrace_state_t *state)
10095 {
10096 	dtrace_enabling_t *enab;
10097 	int i;
10098 
10099 	for (enab = dtrace_retained; enab != NULL; enab = enab->dten_next) {
10100 		ASSERT(enab->dten_vstate->dtvs_state != NULL);
10101 
10102 		if (enab->dten_vstate->dtvs_state != state)
10103 			continue;
10104 
10105 		/*
10106 		 * We don't want to prime an enabling more than once, lest
10107 		 * we allow a malicious user to induce resource exhaustion.
10108 		 * (The ECBs that result from priming an enabling aren't
10109 		 * leaked -- but they also aren't deallocated until the
10110 		 * consumer state is destroyed.)
10111 		 */
10112 		if (enab->dten_primed)
10113 			continue;
10114 
10115 		for (i = 0; i < enab->dten_ndesc; i++) {
10116 			enab->dten_current = enab->dten_desc[i];
10117 			(void) dtrace_probe_enable(NULL, enab);
10118 		}
10119 
10120 		enab->dten_primed = 1;
10121 	}
10122 }
10123 
10124 /*
10125  * Called to indicate that probes should be provided due to retained
10126  * enablings.  This is implemented in terms of dtrace_probe_provide(), but it
10127  * must take an initial lap through the enabling calling the dtps_provide()
10128  * entry point explicitly to allow for autocreated probes.
10129  */
10130 static void
10131 dtrace_enabling_provide(dtrace_provider_t *prv)
10132 {
10133 	int i, all = 0;
10134 	dtrace_probedesc_t desc;
10135 
10136 	ASSERT(MUTEX_HELD(&dtrace_lock));
10137 	ASSERT(MUTEX_HELD(&dtrace_provider_lock));
10138 
10139 	if (prv == NULL) {
10140 		all = 1;
10141 		prv = dtrace_provider;
10142 	}
10143 
10144 	do {
10145 		dtrace_enabling_t *enab = dtrace_retained;
10146 		void *parg = prv->dtpv_arg;
10147 
10148 		for (; enab != NULL; enab = enab->dten_next) {
10149 			for (i = 0; i < enab->dten_ndesc; i++) {
10150 				desc = enab->dten_desc[i]->dted_probe;
10151 				mutex_exit(&dtrace_lock);
10152 				prv->dtpv_pops.dtps_provide(parg, &desc);
10153 				mutex_enter(&dtrace_lock);
10154 			}
10155 		}
10156 	} while (all && (prv = prv->dtpv_next) != NULL);
10157 
10158 	mutex_exit(&dtrace_lock);
10159 	dtrace_probe_provide(NULL, all ? NULL : prv);
10160 	mutex_enter(&dtrace_lock);
10161 }
10162 
10163 /*
10164  * DTrace DOF Functions
10165  */
10166 /*ARGSUSED*/
10167 static void
10168 dtrace_dof_error(dof_hdr_t *dof, const char *str)
10169 {
10170 	if (dtrace_err_verbose)
10171 		cmn_err(CE_WARN, "failed to process DOF: %s", str);
10172 
10173 #ifdef DTRACE_ERRDEBUG
10174 	dtrace_errdebug(str);
10175 #endif
10176 }
10177 
10178 /*
10179  * Create DOF out of a currently enabled state.  Right now, we only create
10180  * DOF containing the run-time options -- but this could be expanded to create
10181  * complete DOF representing the enabled state.
10182  */
10183 static dof_hdr_t *
10184 dtrace_dof_create(dtrace_state_t *state)
10185 {
10186 	dof_hdr_t *dof;
10187 	dof_sec_t *sec;
10188 	dof_optdesc_t *opt;
10189 	int i, len = sizeof (dof_hdr_t) +
10190 	    roundup(sizeof (dof_sec_t), sizeof (uint64_t)) +
10191 	    sizeof (dof_optdesc_t) * DTRACEOPT_MAX;
10192 
10193 	ASSERT(MUTEX_HELD(&dtrace_lock));
10194 
10195 	dof = kmem_zalloc(len, KM_SLEEP);
10196 	dof->dofh_ident[DOF_ID_MAG0] = DOF_MAG_MAG0;
10197 	dof->dofh_ident[DOF_ID_MAG1] = DOF_MAG_MAG1;
10198 	dof->dofh_ident[DOF_ID_MAG2] = DOF_MAG_MAG2;
10199 	dof->dofh_ident[DOF_ID_MAG3] = DOF_MAG_MAG3;
10200 
10201 	dof->dofh_ident[DOF_ID_MODEL] = DOF_MODEL_NATIVE;
10202 	dof->dofh_ident[DOF_ID_ENCODING] = DOF_ENCODE_NATIVE;
10203 	dof->dofh_ident[DOF_ID_VERSION] = DOF_VERSION;
10204 	dof->dofh_ident[DOF_ID_DIFVERS] = DIF_VERSION;
10205 	dof->dofh_ident[DOF_ID_DIFIREG] = DIF_DIR_NREGS;
10206 	dof->dofh_ident[DOF_ID_DIFTREG] = DIF_DTR_NREGS;
10207 
10208 	dof->dofh_flags = 0;
10209 	dof->dofh_hdrsize = sizeof (dof_hdr_t);
10210 	dof->dofh_secsize = sizeof (dof_sec_t);
10211 	dof->dofh_secnum = 1;	/* only DOF_SECT_OPTDESC */
10212 	dof->dofh_secoff = sizeof (dof_hdr_t);
10213 	dof->dofh_loadsz = len;
10214 	dof->dofh_filesz = len;
10215 	dof->dofh_pad = 0;
10216 
10217 	/*
10218 	 * Fill in the option section header...
10219 	 */
10220 	sec = (dof_sec_t *)((uintptr_t)dof + sizeof (dof_hdr_t));
10221 	sec->dofs_type = DOF_SECT_OPTDESC;
10222 	sec->dofs_align = sizeof (uint64_t);
10223 	sec->dofs_flags = DOF_SECF_LOAD;
10224 	sec->dofs_entsize = sizeof (dof_optdesc_t);
10225 
10226 	opt = (dof_optdesc_t *)((uintptr_t)sec +
10227 	    roundup(sizeof (dof_sec_t), sizeof (uint64_t)));
10228 
10229 	sec->dofs_offset = (uintptr_t)opt - (uintptr_t)dof;
10230 	sec->dofs_size = sizeof (dof_optdesc_t) * DTRACEOPT_MAX;
10231 
10232 	for (i = 0; i < DTRACEOPT_MAX; i++) {
10233 		opt[i].dofo_option = i;
10234 		opt[i].dofo_strtab = DOF_SECIDX_NONE;
10235 		opt[i].dofo_value = state->dts_options[i];
10236 	}
10237 
10238 	return (dof);
10239 }
10240 
10241 static dof_hdr_t *
10242 dtrace_dof_copyin(uintptr_t uarg, int *errp)
10243 {
10244 	dof_hdr_t hdr, *dof;
10245 
10246 	ASSERT(!MUTEX_HELD(&dtrace_lock));
10247 
10248 	/*
10249 	 * First, we're going to copyin() the sizeof (dof_hdr_t).
10250 	 */
10251 	if (copyin((void *)uarg, &hdr, sizeof (hdr)) != 0) {
10252 		dtrace_dof_error(NULL, "failed to copyin DOF header");
10253 		*errp = EFAULT;
10254 		return (NULL);
10255 	}
10256 
10257 	/*
10258 	 * Now we'll allocate the entire DOF and copy it in -- provided
10259 	 * that the length isn't outrageous.
10260 	 */
10261 	if (hdr.dofh_loadsz >= dtrace_dof_maxsize) {
10262 		dtrace_dof_error(&hdr, "load size exceeds maximum");
10263 		*errp = E2BIG;
10264 		return (NULL);
10265 	}
10266 
10267 	if (hdr.dofh_loadsz < sizeof (hdr)) {
10268 		dtrace_dof_error(&hdr, "invalid load size");
10269 		*errp = EINVAL;
10270 		return (NULL);
10271 	}
10272 
10273 	dof = kmem_alloc(hdr.dofh_loadsz, KM_SLEEP);
10274 
10275 	if (copyin((void *)uarg, dof, hdr.dofh_loadsz) != 0) {
10276 		kmem_free(dof, hdr.dofh_loadsz);
10277 		*errp = EFAULT;
10278 		return (NULL);
10279 	}
10280 
10281 	return (dof);
10282 }
10283 
10284 static dof_hdr_t *
10285 dtrace_dof_property(const char *name)
10286 {
10287 	uchar_t *buf;
10288 	uint64_t loadsz;
10289 	unsigned int len, i;
10290 	dof_hdr_t *dof;
10291 
10292 	/*
10293 	 * Unfortunately, array of values in .conf files are always (and
10294 	 * only) interpreted to be integer arrays.  We must read our DOF
10295 	 * as an integer array, and then squeeze it into a byte array.
10296 	 */
10297 	if (ddi_prop_lookup_int_array(DDI_DEV_T_ANY, dtrace_devi, 0,
10298 	    (char *)name, (int **)&buf, &len) != DDI_PROP_SUCCESS)
10299 		return (NULL);
10300 
10301 	for (i = 0; i < len; i++)
10302 		buf[i] = (uchar_t)(((int *)buf)[i]);
10303 
10304 	if (len < sizeof (dof_hdr_t)) {
10305 		ddi_prop_free(buf);
10306 		dtrace_dof_error(NULL, "truncated header");
10307 		return (NULL);
10308 	}
10309 
10310 	if (len < (loadsz = ((dof_hdr_t *)buf)->dofh_loadsz)) {
10311 		ddi_prop_free(buf);
10312 		dtrace_dof_error(NULL, "truncated DOF");
10313 		return (NULL);
10314 	}
10315 
10316 	if (loadsz >= dtrace_dof_maxsize) {
10317 		ddi_prop_free(buf);
10318 		dtrace_dof_error(NULL, "oversized DOF");
10319 		return (NULL);
10320 	}
10321 
10322 	dof = kmem_alloc(loadsz, KM_SLEEP);
10323 	bcopy(buf, dof, loadsz);
10324 	ddi_prop_free(buf);
10325 
10326 	return (dof);
10327 }
10328 
10329 static void
10330 dtrace_dof_destroy(dof_hdr_t *dof)
10331 {
10332 	kmem_free(dof, dof->dofh_loadsz);
10333 }
10334 
10335 /*
10336  * Return the dof_sec_t pointer corresponding to a given section index.  If the
10337  * index is not valid, dtrace_dof_error() is called and NULL is returned.  If
10338  * a type other than DOF_SECT_NONE is specified, the header is checked against
10339  * this type and NULL is returned if the types do not match.
10340  */
10341 static dof_sec_t *
10342 dtrace_dof_sect(dof_hdr_t *dof, uint32_t type, dof_secidx_t i)
10343 {
10344 	dof_sec_t *sec = (dof_sec_t *)(uintptr_t)
10345 	    ((uintptr_t)dof + dof->dofh_secoff + i * dof->dofh_secsize);
10346 
10347 	if (i >= dof->dofh_secnum) {
10348 		dtrace_dof_error(dof, "referenced section index is invalid");
10349 		return (NULL);
10350 	}
10351 
10352 	if (!(sec->dofs_flags & DOF_SECF_LOAD)) {
10353 		dtrace_dof_error(dof, "referenced section is not loadable");
10354 		return (NULL);
10355 	}
10356 
10357 	if (type != DOF_SECT_NONE && type != sec->dofs_type) {
10358 		dtrace_dof_error(dof, "referenced section is the wrong type");
10359 		return (NULL);
10360 	}
10361 
10362 	return (sec);
10363 }
10364 
10365 static dtrace_probedesc_t *
10366 dtrace_dof_probedesc(dof_hdr_t *dof, dof_sec_t *sec, dtrace_probedesc_t *desc)
10367 {
10368 	dof_probedesc_t *probe;
10369 	dof_sec_t *strtab;
10370 	uintptr_t daddr = (uintptr_t)dof;
10371 	uintptr_t str;
10372 	size_t size;
10373 
10374 	if (sec->dofs_type != DOF_SECT_PROBEDESC) {
10375 		dtrace_dof_error(dof, "invalid probe section");
10376 		return (NULL);
10377 	}
10378 
10379 	if (sec->dofs_align != sizeof (dof_secidx_t)) {
10380 		dtrace_dof_error(dof, "bad alignment in probe description");
10381 		return (NULL);
10382 	}
10383 
10384 	if (sec->dofs_offset + sizeof (dof_probedesc_t) > dof->dofh_loadsz) {
10385 		dtrace_dof_error(dof, "truncated probe description");
10386 		return (NULL);
10387 	}
10388 
10389 	probe = (dof_probedesc_t *)(uintptr_t)(daddr + sec->dofs_offset);
10390 	strtab = dtrace_dof_sect(dof, DOF_SECT_STRTAB, probe->dofp_strtab);
10391 
10392 	if (strtab == NULL)
10393 		return (NULL);
10394 
10395 	str = daddr + strtab->dofs_offset;
10396 	size = strtab->dofs_size;
10397 
10398 	if (probe->dofp_provider >= strtab->dofs_size) {
10399 		dtrace_dof_error(dof, "corrupt probe provider");
10400 		return (NULL);
10401 	}
10402 
10403 	(void) strncpy(desc->dtpd_provider,
10404 	    (char *)(str + probe->dofp_provider),
10405 	    MIN(DTRACE_PROVNAMELEN - 1, size - probe->dofp_provider));
10406 
10407 	if (probe->dofp_mod >= strtab->dofs_size) {
10408 		dtrace_dof_error(dof, "corrupt probe module");
10409 		return (NULL);
10410 	}
10411 
10412 	(void) strncpy(desc->dtpd_mod, (char *)(str + probe->dofp_mod),
10413 	    MIN(DTRACE_MODNAMELEN - 1, size - probe->dofp_mod));
10414 
10415 	if (probe->dofp_func >= strtab->dofs_size) {
10416 		dtrace_dof_error(dof, "corrupt probe function");
10417 		return (NULL);
10418 	}
10419 
10420 	(void) strncpy(desc->dtpd_func, (char *)(str + probe->dofp_func),
10421 	    MIN(DTRACE_FUNCNAMELEN - 1, size - probe->dofp_func));
10422 
10423 	if (probe->dofp_name >= strtab->dofs_size) {
10424 		dtrace_dof_error(dof, "corrupt probe name");
10425 		return (NULL);
10426 	}
10427 
10428 	(void) strncpy(desc->dtpd_name, (char *)(str + probe->dofp_name),
10429 	    MIN(DTRACE_NAMELEN - 1, size - probe->dofp_name));
10430 
10431 	return (desc);
10432 }
10433 
10434 static dtrace_difo_t *
10435 dtrace_dof_difo(dof_hdr_t *dof, dof_sec_t *sec, dtrace_vstate_t *vstate,
10436     cred_t *cr)
10437 {
10438 	dtrace_difo_t *dp;
10439 	size_t ttl = 0;
10440 	dof_difohdr_t *dofd;
10441 	uintptr_t daddr = (uintptr_t)dof;
10442 	size_t max = dtrace_difo_maxsize;
10443 	int i, l, n;
10444 
10445 	static const struct {
10446 		int section;
10447 		int bufoffs;
10448 		int lenoffs;
10449 		int entsize;
10450 		int align;
10451 		const char *msg;
10452 	} difo[] = {
10453 		{ DOF_SECT_DIF, offsetof(dtrace_difo_t, dtdo_buf),
10454 		offsetof(dtrace_difo_t, dtdo_len), sizeof (dif_instr_t),
10455 		sizeof (dif_instr_t), "multiple DIF sections" },
10456 
10457 		{ DOF_SECT_INTTAB, offsetof(dtrace_difo_t, dtdo_inttab),
10458 		offsetof(dtrace_difo_t, dtdo_intlen), sizeof (uint64_t),
10459 		sizeof (uint64_t), "multiple integer tables" },
10460 
10461 		{ DOF_SECT_STRTAB, offsetof(dtrace_difo_t, dtdo_strtab),
10462 		offsetof(dtrace_difo_t, dtdo_strlen), 0,
10463 		sizeof (char), "multiple string tables" },
10464 
10465 		{ DOF_SECT_VARTAB, offsetof(dtrace_difo_t, dtdo_vartab),
10466 		offsetof(dtrace_difo_t, dtdo_varlen), sizeof (dtrace_difv_t),
10467 		sizeof (uint_t), "multiple variable tables" },
10468 
10469 		{ DOF_SECT_NONE, 0, 0, 0, NULL }
10470 	};
10471 
10472 	if (sec->dofs_type != DOF_SECT_DIFOHDR) {
10473 		dtrace_dof_error(dof, "invalid DIFO header section");
10474 		return (NULL);
10475 	}
10476 
10477 	if (sec->dofs_align != sizeof (dof_secidx_t)) {
10478 		dtrace_dof_error(dof, "bad alignment in DIFO header");
10479 		return (NULL);
10480 	}
10481 
10482 	if (sec->dofs_size < sizeof (dof_difohdr_t) ||
10483 	    sec->dofs_size % sizeof (dof_secidx_t)) {
10484 		dtrace_dof_error(dof, "bad size in DIFO header");
10485 		return (NULL);
10486 	}
10487 
10488 	dofd = (dof_difohdr_t *)(uintptr_t)(daddr + sec->dofs_offset);
10489 	n = (sec->dofs_size - sizeof (*dofd)) / sizeof (dof_secidx_t) + 1;
10490 
10491 	dp = kmem_zalloc(sizeof (dtrace_difo_t), KM_SLEEP);
10492 	dp->dtdo_rtype = dofd->dofd_rtype;
10493 
10494 	for (l = 0; l < n; l++) {
10495 		dof_sec_t *subsec;
10496 		void **bufp;
10497 		uint32_t *lenp;
10498 
10499 		if ((subsec = dtrace_dof_sect(dof, DOF_SECT_NONE,
10500 		    dofd->dofd_links[l])) == NULL)
10501 			goto err; /* invalid section link */
10502 
10503 		if (ttl + subsec->dofs_size > max) {
10504 			dtrace_dof_error(dof, "exceeds maximum size");
10505 			goto err;
10506 		}
10507 
10508 		ttl += subsec->dofs_size;
10509 
10510 		for (i = 0; difo[i].section != DOF_SECT_NONE; i++) {
10511 			if (subsec->dofs_type != difo[i].section)
10512 				continue;
10513 
10514 			if (!(subsec->dofs_flags & DOF_SECF_LOAD)) {
10515 				dtrace_dof_error(dof, "section not loaded");
10516 				goto err;
10517 			}
10518 
10519 			if (subsec->dofs_align != difo[i].align) {
10520 				dtrace_dof_error(dof, "bad alignment");
10521 				goto err;
10522 			}
10523 
10524 			bufp = (void **)((uintptr_t)dp + difo[i].bufoffs);
10525 			lenp = (uint32_t *)((uintptr_t)dp + difo[i].lenoffs);
10526 
10527 			if (*bufp != NULL) {
10528 				dtrace_dof_error(dof, difo[i].msg);
10529 				goto err;
10530 			}
10531 
10532 			if (difo[i].entsize != subsec->dofs_entsize) {
10533 				dtrace_dof_error(dof, "entry size mismatch");
10534 				goto err;
10535 			}
10536 
10537 			if (subsec->dofs_entsize != 0 &&
10538 			    (subsec->dofs_size % subsec->dofs_entsize) != 0) {
10539 				dtrace_dof_error(dof, "corrupt entry size");
10540 				goto err;
10541 			}
10542 
10543 			*lenp = subsec->dofs_size;
10544 			*bufp = kmem_alloc(subsec->dofs_size, KM_SLEEP);
10545 			bcopy((char *)(uintptr_t)(daddr + subsec->dofs_offset),
10546 			    *bufp, subsec->dofs_size);
10547 
10548 			if (subsec->dofs_entsize != 0)
10549 				*lenp /= subsec->dofs_entsize;
10550 
10551 			break;
10552 		}
10553 
10554 		/*
10555 		 * If we encounter a loadable DIFO sub-section that is not
10556 		 * known to us, assume this is a broken program and fail.
10557 		 */
10558 		if (difo[i].section == DOF_SECT_NONE &&
10559 		    (subsec->dofs_flags & DOF_SECF_LOAD)) {
10560 			dtrace_dof_error(dof, "unrecognized DIFO subsection");
10561 			goto err;
10562 		}
10563 	}
10564 
10565 	if (dp->dtdo_buf == NULL) {
10566 		/*
10567 		 * We can't have a DIF object without DIF text.
10568 		 */
10569 		dtrace_dof_error(dof, "missing DIF text");
10570 		goto err;
10571 	}
10572 
10573 	/*
10574 	 * Before we validate the DIF object, run through the variable table
10575 	 * looking for the strings -- if any of their size are under, we'll set
10576 	 * their size to be the system-wide default string size.  Note that
10577 	 * this should _not_ happen if the "strsize" option has been set --
10578 	 * in this case, the compiler should have set the size to reflect the
10579 	 * setting of the option.
10580 	 */
10581 	for (i = 0; i < dp->dtdo_varlen; i++) {
10582 		dtrace_difv_t *v = &dp->dtdo_vartab[i];
10583 		dtrace_diftype_t *t = &v->dtdv_type;
10584 
10585 		if (v->dtdv_id < DIF_VAR_OTHER_UBASE)
10586 			continue;
10587 
10588 		if (t->dtdt_kind == DIF_TYPE_STRING && t->dtdt_size == 0)
10589 			t->dtdt_size = dtrace_strsize_default;
10590 	}
10591 
10592 	if (dtrace_difo_validate(dp, vstate, DIF_DIR_NREGS, cr) != 0)
10593 		goto err;
10594 
10595 	dtrace_difo_init(dp, vstate);
10596 	return (dp);
10597 
10598 err:
10599 	kmem_free(dp->dtdo_buf, dp->dtdo_len * sizeof (dif_instr_t));
10600 	kmem_free(dp->dtdo_inttab, dp->dtdo_intlen * sizeof (uint64_t));
10601 	kmem_free(dp->dtdo_strtab, dp->dtdo_strlen);
10602 	kmem_free(dp->dtdo_vartab, dp->dtdo_varlen * sizeof (dtrace_difv_t));
10603 
10604 	kmem_free(dp, sizeof (dtrace_difo_t));
10605 	return (NULL);
10606 }
10607 
10608 static dtrace_predicate_t *
10609 dtrace_dof_predicate(dof_hdr_t *dof, dof_sec_t *sec, dtrace_vstate_t *vstate,
10610     cred_t *cr)
10611 {
10612 	dtrace_difo_t *dp;
10613 
10614 	if ((dp = dtrace_dof_difo(dof, sec, vstate, cr)) == NULL)
10615 		return (NULL);
10616 
10617 	return (dtrace_predicate_create(dp));
10618 }
10619 
10620 static dtrace_actdesc_t *
10621 dtrace_dof_actdesc(dof_hdr_t *dof, dof_sec_t *sec, dtrace_vstate_t *vstate,
10622     cred_t *cr)
10623 {
10624 	dtrace_actdesc_t *act, *first = NULL, *last = NULL, *next;
10625 	dof_actdesc_t *desc;
10626 	dof_sec_t *difosec;
10627 	size_t offs;
10628 	uintptr_t daddr = (uintptr_t)dof;
10629 	uint64_t arg;
10630 	dtrace_actkind_t kind;
10631 
10632 	if (sec->dofs_type != DOF_SECT_ACTDESC) {
10633 		dtrace_dof_error(dof, "invalid action section");
10634 		return (NULL);
10635 	}
10636 
10637 	if (sec->dofs_offset + sizeof (dof_actdesc_t) > dof->dofh_loadsz) {
10638 		dtrace_dof_error(dof, "truncated action description");
10639 		return (NULL);
10640 	}
10641 
10642 	if (sec->dofs_align != sizeof (uint64_t)) {
10643 		dtrace_dof_error(dof, "bad alignment in action description");
10644 		return (NULL);
10645 	}
10646 
10647 	if (sec->dofs_size < sec->dofs_entsize) {
10648 		dtrace_dof_error(dof, "section entry size exceeds total size");
10649 		return (NULL);
10650 	}
10651 
10652 	if (sec->dofs_entsize != sizeof (dof_actdesc_t)) {
10653 		dtrace_dof_error(dof, "bad entry size in action description");
10654 		return (NULL);
10655 	}
10656 
10657 	if (sec->dofs_size / sec->dofs_entsize > dtrace_actions_max) {
10658 		dtrace_dof_error(dof, "actions exceed dtrace_actions_max");
10659 		return (NULL);
10660 	}
10661 
10662 	for (offs = 0; offs < sec->dofs_size; offs += sec->dofs_entsize) {
10663 		desc = (dof_actdesc_t *)(daddr +
10664 		    (uintptr_t)sec->dofs_offset + offs);
10665 		kind = (dtrace_actkind_t)desc->dofa_kind;
10666 
10667 		if (DTRACEACT_ISPRINTFLIKE(kind) &&
10668 		    (kind != DTRACEACT_PRINTA ||
10669 		    desc->dofa_strtab != DOF_SECIDX_NONE)) {
10670 			dof_sec_t *strtab;
10671 			char *str, *fmt;
10672 			uint64_t i;
10673 
10674 			/*
10675 			 * printf()-like actions must have a format string.
10676 			 */
10677 			if ((strtab = dtrace_dof_sect(dof,
10678 			    DOF_SECT_STRTAB, desc->dofa_strtab)) == NULL)
10679 				goto err;
10680 
10681 			str = (char *)((uintptr_t)dof +
10682 			    (uintptr_t)strtab->dofs_offset);
10683 
10684 			for (i = desc->dofa_arg; i < strtab->dofs_size; i++) {
10685 				if (str[i] == '\0')
10686 					break;
10687 			}
10688 
10689 			if (i >= strtab->dofs_size) {
10690 				dtrace_dof_error(dof, "bogus format string");
10691 				goto err;
10692 			}
10693 
10694 			if (i == desc->dofa_arg) {
10695 				dtrace_dof_error(dof, "empty format string");
10696 				goto err;
10697 			}
10698 
10699 			i -= desc->dofa_arg;
10700 			fmt = kmem_alloc(i + 1, KM_SLEEP);
10701 			bcopy(&str[desc->dofa_arg], fmt, i + 1);
10702 			arg = (uint64_t)(uintptr_t)fmt;
10703 		} else {
10704 			if (kind == DTRACEACT_PRINTA) {
10705 				ASSERT(desc->dofa_strtab == DOF_SECIDX_NONE);
10706 				arg = 0;
10707 			} else {
10708 				arg = desc->dofa_arg;
10709 			}
10710 		}
10711 
10712 		act = dtrace_actdesc_create(kind, desc->dofa_ntuple,
10713 		    desc->dofa_uarg, arg);
10714 
10715 		if (last != NULL) {
10716 			last->dtad_next = act;
10717 		} else {
10718 			first = act;
10719 		}
10720 
10721 		last = act;
10722 
10723 		if (desc->dofa_difo == DOF_SECIDX_NONE)
10724 			continue;
10725 
10726 		if ((difosec = dtrace_dof_sect(dof,
10727 		    DOF_SECT_DIFOHDR, desc->dofa_difo)) == NULL)
10728 			goto err;
10729 
10730 		act->dtad_difo = dtrace_dof_difo(dof, difosec, vstate, cr);
10731 
10732 		if (act->dtad_difo == NULL)
10733 			goto err;
10734 	}
10735 
10736 	ASSERT(first != NULL);
10737 	return (first);
10738 
10739 err:
10740 	for (act = first; act != NULL; act = next) {
10741 		next = act->dtad_next;
10742 		dtrace_actdesc_release(act, vstate);
10743 	}
10744 
10745 	return (NULL);
10746 }
10747 
10748 static dtrace_ecbdesc_t *
10749 dtrace_dof_ecbdesc(dof_hdr_t *dof, dof_sec_t *sec, dtrace_vstate_t *vstate,
10750     cred_t *cr)
10751 {
10752 	dtrace_ecbdesc_t *ep;
10753 	dof_ecbdesc_t *ecb;
10754 	dtrace_probedesc_t *desc;
10755 	dtrace_predicate_t *pred = NULL;
10756 
10757 	if (sec->dofs_size < sizeof (dof_ecbdesc_t)) {
10758 		dtrace_dof_error(dof, "truncated ECB description");
10759 		return (NULL);
10760 	}
10761 
10762 	if (sec->dofs_align != sizeof (uint64_t)) {
10763 		dtrace_dof_error(dof, "bad alignment in ECB description");
10764 		return (NULL);
10765 	}
10766 
10767 	ecb = (dof_ecbdesc_t *)((uintptr_t)dof + (uintptr_t)sec->dofs_offset);
10768 	sec = dtrace_dof_sect(dof, DOF_SECT_PROBEDESC, ecb->dofe_probes);
10769 
10770 	if (sec == NULL)
10771 		return (NULL);
10772 
10773 	ep = kmem_zalloc(sizeof (dtrace_ecbdesc_t), KM_SLEEP);
10774 	ep->dted_uarg = ecb->dofe_uarg;
10775 	desc = &ep->dted_probe;
10776 
10777 	if (dtrace_dof_probedesc(dof, sec, desc) == NULL)
10778 		goto err;
10779 
10780 	if (ecb->dofe_pred != DOF_SECIDX_NONE) {
10781 		if ((sec = dtrace_dof_sect(dof,
10782 		    DOF_SECT_DIFOHDR, ecb->dofe_pred)) == NULL)
10783 			goto err;
10784 
10785 		if ((pred = dtrace_dof_predicate(dof, sec, vstate, cr)) == NULL)
10786 			goto err;
10787 
10788 		ep->dted_pred.dtpdd_predicate = pred;
10789 	}
10790 
10791 	if (ecb->dofe_actions != DOF_SECIDX_NONE) {
10792 		if ((sec = dtrace_dof_sect(dof,
10793 		    DOF_SECT_ACTDESC, ecb->dofe_actions)) == NULL)
10794 			goto err;
10795 
10796 		ep->dted_action = dtrace_dof_actdesc(dof, sec, vstate, cr);
10797 
10798 		if (ep->dted_action == NULL)
10799 			goto err;
10800 	}
10801 
10802 	return (ep);
10803 
10804 err:
10805 	if (pred != NULL)
10806 		dtrace_predicate_release(pred, vstate);
10807 	kmem_free(ep, sizeof (dtrace_ecbdesc_t));
10808 	return (NULL);
10809 }
10810 
10811 /*
10812  * Apply the relocations from the specified 'sec' (a DOF_SECT_URELHDR) to the
10813  * specified DOF.  At present, this amounts to simply adding 'ubase' to the
10814  * site of any user SETX relocations to account for load object base address.
10815  * In the future, if we need other relocations, this function can be extended.
10816  */
10817 static int
10818 dtrace_dof_relocate(dof_hdr_t *dof, dof_sec_t *sec, uint64_t ubase)
10819 {
10820 	uintptr_t daddr = (uintptr_t)dof;
10821 	dof_relohdr_t *dofr =
10822 	    (dof_relohdr_t *)(uintptr_t)(daddr + sec->dofs_offset);
10823 	dof_sec_t *ss, *rs, *ts;
10824 	dof_relodesc_t *r;
10825 	uint_t i, n;
10826 
10827 	if (sec->dofs_size < sizeof (dof_relohdr_t) ||
10828 	    sec->dofs_align != sizeof (dof_secidx_t)) {
10829 		dtrace_dof_error(dof, "invalid relocation header");
10830 		return (-1);
10831 	}
10832 
10833 	ss = dtrace_dof_sect(dof, DOF_SECT_STRTAB, dofr->dofr_strtab);
10834 	rs = dtrace_dof_sect(dof, DOF_SECT_RELTAB, dofr->dofr_relsec);
10835 	ts = dtrace_dof_sect(dof, DOF_SECT_NONE, dofr->dofr_tgtsec);
10836 
10837 	if (ss == NULL || rs == NULL || ts == NULL)
10838 		return (-1); /* dtrace_dof_error() has been called already */
10839 
10840 	if (rs->dofs_entsize < sizeof (dof_relodesc_t) ||
10841 	    rs->dofs_align != sizeof (uint64_t)) {
10842 		dtrace_dof_error(dof, "invalid relocation section");
10843 		return (-1);
10844 	}
10845 
10846 	r = (dof_relodesc_t *)(uintptr_t)(daddr + rs->dofs_offset);
10847 	n = rs->dofs_size / rs->dofs_entsize;
10848 
10849 	for (i = 0; i < n; i++) {
10850 		uintptr_t taddr = daddr + ts->dofs_offset + r->dofr_offset;
10851 
10852 		switch (r->dofr_type) {
10853 		case DOF_RELO_NONE:
10854 			break;
10855 		case DOF_RELO_SETX:
10856 			if (r->dofr_offset >= ts->dofs_size || r->dofr_offset +
10857 			    sizeof (uint64_t) > ts->dofs_size) {
10858 				dtrace_dof_error(dof, "bad relocation offset");
10859 				return (-1);
10860 			}
10861 
10862 			if (!IS_P2ALIGNED(taddr, sizeof (uint64_t))) {
10863 				dtrace_dof_error(dof, "misaligned setx relo");
10864 				return (-1);
10865 			}
10866 
10867 			*(uint64_t *)taddr += ubase;
10868 			break;
10869 		default:
10870 			dtrace_dof_error(dof, "invalid relocation type");
10871 			return (-1);
10872 		}
10873 
10874 		r = (dof_relodesc_t *)((uintptr_t)r + rs->dofs_entsize);
10875 	}
10876 
10877 	return (0);
10878 }
10879 
10880 /*
10881  * The dof_hdr_t passed to dtrace_dof_slurp() should be a partially validated
10882  * header:  it should be at the front of a memory region that is at least
10883  * sizeof (dof_hdr_t) in size -- and then at least dof_hdr.dofh_loadsz in
10884  * size.  It need not be validated in any other way.
10885  */
10886 static int
10887 dtrace_dof_slurp(dof_hdr_t *dof, dtrace_vstate_t *vstate, cred_t *cr,
10888     dtrace_enabling_t **enabp, uint64_t ubase, int noprobes)
10889 {
10890 	uint64_t len = dof->dofh_loadsz, seclen;
10891 	uintptr_t daddr = (uintptr_t)dof;
10892 	dtrace_ecbdesc_t *ep;
10893 	dtrace_enabling_t *enab;
10894 	uint_t i;
10895 
10896 	ASSERT(MUTEX_HELD(&dtrace_lock));
10897 	ASSERT(dof->dofh_loadsz >= sizeof (dof_hdr_t));
10898 
10899 	/*
10900 	 * Check the DOF header identification bytes.  In addition to checking
10901 	 * valid settings, we also verify that unused bits/bytes are zeroed so
10902 	 * we can use them later without fear of regressing existing binaries.
10903 	 */
10904 	if (bcmp(&dof->dofh_ident[DOF_ID_MAG0],
10905 	    DOF_MAG_STRING, DOF_MAG_STRLEN) != 0) {
10906 		dtrace_dof_error(dof, "DOF magic string mismatch");
10907 		return (-1);
10908 	}
10909 
10910 	if (dof->dofh_ident[DOF_ID_MODEL] != DOF_MODEL_ILP32 &&
10911 	    dof->dofh_ident[DOF_ID_MODEL] != DOF_MODEL_LP64) {
10912 		dtrace_dof_error(dof, "DOF has invalid data model");
10913 		return (-1);
10914 	}
10915 
10916 	if (dof->dofh_ident[DOF_ID_ENCODING] != DOF_ENCODE_NATIVE) {
10917 		dtrace_dof_error(dof, "DOF encoding mismatch");
10918 		return (-1);
10919 	}
10920 
10921 	if (dof->dofh_ident[DOF_ID_VERSION] != DOF_VERSION_1 &&
10922 	    dof->dofh_ident[DOF_ID_VERSION] != DOF_VERSION_2) {
10923 		dtrace_dof_error(dof, "DOF version mismatch");
10924 		return (-1);
10925 	}
10926 
10927 	if (dof->dofh_ident[DOF_ID_DIFVERS] != DIF_VERSION_2) {
10928 		dtrace_dof_error(dof, "DOF uses unsupported instruction set");
10929 		return (-1);
10930 	}
10931 
10932 	if (dof->dofh_ident[DOF_ID_DIFIREG] > DIF_DIR_NREGS) {
10933 		dtrace_dof_error(dof, "DOF uses too many integer registers");
10934 		return (-1);
10935 	}
10936 
10937 	if (dof->dofh_ident[DOF_ID_DIFTREG] > DIF_DTR_NREGS) {
10938 		dtrace_dof_error(dof, "DOF uses too many tuple registers");
10939 		return (-1);
10940 	}
10941 
10942 	for (i = DOF_ID_PAD; i < DOF_ID_SIZE; i++) {
10943 		if (dof->dofh_ident[i] != 0) {
10944 			dtrace_dof_error(dof, "DOF has invalid ident byte set");
10945 			return (-1);
10946 		}
10947 	}
10948 
10949 	if (dof->dofh_flags & ~DOF_FL_VALID) {
10950 		dtrace_dof_error(dof, "DOF has invalid flag bits set");
10951 		return (-1);
10952 	}
10953 
10954 	if (dof->dofh_secsize == 0) {
10955 		dtrace_dof_error(dof, "zero section header size");
10956 		return (-1);
10957 	}
10958 
10959 	/*
10960 	 * Check that the section headers don't exceed the amount of DOF
10961 	 * data.  Note that we cast the section size and number of sections
10962 	 * to uint64_t's to prevent possible overflow in the multiplication.
10963 	 */
10964 	seclen = (uint64_t)dof->dofh_secnum * (uint64_t)dof->dofh_secsize;
10965 
10966 	if (dof->dofh_secoff > len || seclen > len ||
10967 	    dof->dofh_secoff + seclen > len) {
10968 		dtrace_dof_error(dof, "truncated section headers");
10969 		return (-1);
10970 	}
10971 
10972 	if (!IS_P2ALIGNED(dof->dofh_secoff, sizeof (uint64_t))) {
10973 		dtrace_dof_error(dof, "misaligned section headers");
10974 		return (-1);
10975 	}
10976 
10977 	if (!IS_P2ALIGNED(dof->dofh_secsize, sizeof (uint64_t))) {
10978 		dtrace_dof_error(dof, "misaligned section size");
10979 		return (-1);
10980 	}
10981 
10982 	/*
10983 	 * Take an initial pass through the section headers to be sure that
10984 	 * the headers don't have stray offsets.  If the 'noprobes' flag is
10985 	 * set, do not permit sections relating to providers, probes, or args.
10986 	 */
10987 	for (i = 0; i < dof->dofh_secnum; i++) {
10988 		dof_sec_t *sec = (dof_sec_t *)(daddr +
10989 		    (uintptr_t)dof->dofh_secoff + i * dof->dofh_secsize);
10990 
10991 		if (noprobes) {
10992 			switch (sec->dofs_type) {
10993 			case DOF_SECT_PROVIDER:
10994 			case DOF_SECT_PROBES:
10995 			case DOF_SECT_PRARGS:
10996 			case DOF_SECT_PROFFS:
10997 				dtrace_dof_error(dof, "illegal sections "
10998 				    "for enabling");
10999 				return (-1);
11000 			}
11001 		}
11002 
11003 		if (!(sec->dofs_flags & DOF_SECF_LOAD))
11004 			continue; /* just ignore non-loadable sections */
11005 
11006 		if (sec->dofs_align & (sec->dofs_align - 1)) {
11007 			dtrace_dof_error(dof, "bad section alignment");
11008 			return (-1);
11009 		}
11010 
11011 		if (sec->dofs_offset & (sec->dofs_align - 1)) {
11012 			dtrace_dof_error(dof, "misaligned section");
11013 			return (-1);
11014 		}
11015 
11016 		if (sec->dofs_offset > len || sec->dofs_size > len ||
11017 		    sec->dofs_offset + sec->dofs_size > len) {
11018 			dtrace_dof_error(dof, "corrupt section header");
11019 			return (-1);
11020 		}
11021 
11022 		if (sec->dofs_type == DOF_SECT_STRTAB && *((char *)daddr +
11023 		    sec->dofs_offset + sec->dofs_size - 1) != '\0') {
11024 			dtrace_dof_error(dof, "non-terminating string table");
11025 			return (-1);
11026 		}
11027 	}
11028 
11029 	/*
11030 	 * Take a second pass through the sections and locate and perform any
11031 	 * relocations that are present.  We do this after the first pass to
11032 	 * be sure that all sections have had their headers validated.
11033 	 */
11034 	for (i = 0; i < dof->dofh_secnum; i++) {
11035 		dof_sec_t *sec = (dof_sec_t *)(daddr +
11036 		    (uintptr_t)dof->dofh_secoff + i * dof->dofh_secsize);
11037 
11038 		if (!(sec->dofs_flags & DOF_SECF_LOAD))
11039 			continue; /* skip sections that are not loadable */
11040 
11041 		switch (sec->dofs_type) {
11042 		case DOF_SECT_URELHDR:
11043 			if (dtrace_dof_relocate(dof, sec, ubase) != 0)
11044 				return (-1);
11045 			break;
11046 		}
11047 	}
11048 
11049 	if ((enab = *enabp) == NULL)
11050 		enab = *enabp = dtrace_enabling_create(vstate);
11051 
11052 	for (i = 0; i < dof->dofh_secnum; i++) {
11053 		dof_sec_t *sec = (dof_sec_t *)(daddr +
11054 		    (uintptr_t)dof->dofh_secoff + i * dof->dofh_secsize);
11055 
11056 		if (sec->dofs_type != DOF_SECT_ECBDESC)
11057 			continue;
11058 
11059 		if ((ep = dtrace_dof_ecbdesc(dof, sec, vstate, cr)) == NULL) {
11060 			dtrace_enabling_destroy(enab);
11061 			*enabp = NULL;
11062 			return (-1);
11063 		}
11064 
11065 		dtrace_enabling_add(enab, ep);
11066 	}
11067 
11068 	return (0);
11069 }
11070 
11071 /*
11072  * Process DOF for any options.  This routine assumes that the DOF has been
11073  * at least processed by dtrace_dof_slurp().
11074  */
11075 static int
11076 dtrace_dof_options(dof_hdr_t *dof, dtrace_state_t *state)
11077 {
11078 	int i, rval;
11079 	uint32_t entsize;
11080 	size_t offs;
11081 	dof_optdesc_t *desc;
11082 
11083 	for (i = 0; i < dof->dofh_secnum; i++) {
11084 		dof_sec_t *sec = (dof_sec_t *)((uintptr_t)dof +
11085 		    (uintptr_t)dof->dofh_secoff + i * dof->dofh_secsize);
11086 
11087 		if (sec->dofs_type != DOF_SECT_OPTDESC)
11088 			continue;
11089 
11090 		if (sec->dofs_align != sizeof (uint64_t)) {
11091 			dtrace_dof_error(dof, "bad alignment in "
11092 			    "option description");
11093 			return (EINVAL);
11094 		}
11095 
11096 		if ((entsize = sec->dofs_entsize) == 0) {
11097 			dtrace_dof_error(dof, "zeroed option entry size");
11098 			return (EINVAL);
11099 		}
11100 
11101 		if (entsize < sizeof (dof_optdesc_t)) {
11102 			dtrace_dof_error(dof, "bad option entry size");
11103 			return (EINVAL);
11104 		}
11105 
11106 		for (offs = 0; offs < sec->dofs_size; offs += entsize) {
11107 			desc = (dof_optdesc_t *)((uintptr_t)dof +
11108 			    (uintptr_t)sec->dofs_offset + offs);
11109 
11110 			if (desc->dofo_strtab != DOF_SECIDX_NONE) {
11111 				dtrace_dof_error(dof, "non-zero option string");
11112 				return (EINVAL);
11113 			}
11114 
11115 			if (desc->dofo_value == DTRACEOPT_UNSET) {
11116 				dtrace_dof_error(dof, "unset option");
11117 				return (EINVAL);
11118 			}
11119 
11120 			if ((rval = dtrace_state_option(state,
11121 			    desc->dofo_option, desc->dofo_value)) != 0) {
11122 				dtrace_dof_error(dof, "rejected option");
11123 				return (rval);
11124 			}
11125 		}
11126 	}
11127 
11128 	return (0);
11129 }
11130 
11131 /*
11132  * DTrace Consumer State Functions
11133  */
11134 int
11135 dtrace_dstate_init(dtrace_dstate_t *dstate, size_t size)
11136 {
11137 	size_t hashsize, maxper, min, chunksize = dstate->dtds_chunksize;
11138 	void *base;
11139 	uintptr_t limit;
11140 	dtrace_dynvar_t *dvar, *next, *start;
11141 	int i;
11142 
11143 	ASSERT(MUTEX_HELD(&dtrace_lock));
11144 	ASSERT(dstate->dtds_base == NULL && dstate->dtds_percpu == NULL);
11145 
11146 	bzero(dstate, sizeof (dtrace_dstate_t));
11147 
11148 	if ((dstate->dtds_chunksize = chunksize) == 0)
11149 		dstate->dtds_chunksize = DTRACE_DYNVAR_CHUNKSIZE;
11150 
11151 	if (size < (min = dstate->dtds_chunksize + sizeof (dtrace_dynhash_t)))
11152 		size = min;
11153 
11154 	if ((base = kmem_zalloc(size, KM_NOSLEEP)) == NULL)
11155 		return (ENOMEM);
11156 
11157 	dstate->dtds_size = size;
11158 	dstate->dtds_base = base;
11159 	dstate->dtds_percpu = kmem_cache_alloc(dtrace_state_cache, KM_SLEEP);
11160 	bzero(dstate->dtds_percpu, NCPU * sizeof (dtrace_dstate_percpu_t));
11161 
11162 	hashsize = size / (dstate->dtds_chunksize + sizeof (dtrace_dynhash_t));
11163 
11164 	if (hashsize != 1 && (hashsize & 1))
11165 		hashsize--;
11166 
11167 	dstate->dtds_hashsize = hashsize;
11168 	dstate->dtds_hash = dstate->dtds_base;
11169 
11170 	/*
11171 	 * Set all of our hash buckets to point to the single sink, and (if
11172 	 * it hasn't already been set), set the sink's hash value to be the
11173 	 * sink sentinel value.  The sink is needed for dynamic variable
11174 	 * lookups to know that they have iterated over an entire, valid hash
11175 	 * chain.
11176 	 */
11177 	for (i = 0; i < hashsize; i++)
11178 		dstate->dtds_hash[i].dtdh_chain = &dtrace_dynhash_sink;
11179 
11180 	if (dtrace_dynhash_sink.dtdv_hashval != DTRACE_DYNHASH_SINK)
11181 		dtrace_dynhash_sink.dtdv_hashval = DTRACE_DYNHASH_SINK;
11182 
11183 	/*
11184 	 * Determine number of active CPUs.  Divide free list evenly among
11185 	 * active CPUs.
11186 	 */
11187 	start = (dtrace_dynvar_t *)
11188 	    ((uintptr_t)base + hashsize * sizeof (dtrace_dynhash_t));
11189 	limit = (uintptr_t)base + size;
11190 
11191 	maxper = (limit - (uintptr_t)start) / NCPU;
11192 	maxper = (maxper / dstate->dtds_chunksize) * dstate->dtds_chunksize;
11193 
11194 	for (i = 0; i < NCPU; i++) {
11195 		dstate->dtds_percpu[i].dtdsc_free = dvar = start;
11196 
11197 		/*
11198 		 * If we don't even have enough chunks to make it once through
11199 		 * NCPUs, we're just going to allocate everything to the first
11200 		 * CPU.  And if we're on the last CPU, we're going to allocate
11201 		 * whatever is left over.  In either case, we set the limit to
11202 		 * be the limit of the dynamic variable space.
11203 		 */
11204 		if (maxper == 0 || i == NCPU - 1) {
11205 			limit = (uintptr_t)base + size;
11206 			start = NULL;
11207 		} else {
11208 			limit = (uintptr_t)start + maxper;
11209 			start = (dtrace_dynvar_t *)limit;
11210 		}
11211 
11212 		ASSERT(limit <= (uintptr_t)base + size);
11213 
11214 		for (;;) {
11215 			next = (dtrace_dynvar_t *)((uintptr_t)dvar +
11216 			    dstate->dtds_chunksize);
11217 
11218 			if ((uintptr_t)next + dstate->dtds_chunksize >= limit)
11219 				break;
11220 
11221 			dvar->dtdv_next = next;
11222 			dvar = next;
11223 		}
11224 
11225 		if (maxper == 0)
11226 			break;
11227 	}
11228 
11229 	return (0);
11230 }
11231 
11232 void
11233 dtrace_dstate_fini(dtrace_dstate_t *dstate)
11234 {
11235 	ASSERT(MUTEX_HELD(&cpu_lock));
11236 
11237 	if (dstate->dtds_base == NULL)
11238 		return;
11239 
11240 	kmem_free(dstate->dtds_base, dstate->dtds_size);
11241 	kmem_cache_free(dtrace_state_cache, dstate->dtds_percpu);
11242 }
11243 
11244 static void
11245 dtrace_vstate_fini(dtrace_vstate_t *vstate)
11246 {
11247 	/*
11248 	 * Logical XOR, where are you?
11249 	 */
11250 	ASSERT((vstate->dtvs_nglobals == 0) ^ (vstate->dtvs_globals != NULL));
11251 
11252 	if (vstate->dtvs_nglobals > 0) {
11253 		kmem_free(vstate->dtvs_globals, vstate->dtvs_nglobals *
11254 		    sizeof (dtrace_statvar_t *));
11255 	}
11256 
11257 	if (vstate->dtvs_ntlocals > 0) {
11258 		kmem_free(vstate->dtvs_tlocals, vstate->dtvs_ntlocals *
11259 		    sizeof (dtrace_difv_t));
11260 	}
11261 
11262 	ASSERT((vstate->dtvs_nlocals == 0) ^ (vstate->dtvs_locals != NULL));
11263 
11264 	if (vstate->dtvs_nlocals > 0) {
11265 		kmem_free(vstate->dtvs_locals, vstate->dtvs_nlocals *
11266 		    sizeof (dtrace_statvar_t *));
11267 	}
11268 }
11269 
11270 static void
11271 dtrace_state_clean(dtrace_state_t *state)
11272 {
11273 	if (state->dts_activity == DTRACE_ACTIVITY_INACTIVE)
11274 		return;
11275 
11276 	dtrace_dynvar_clean(&state->dts_vstate.dtvs_dynvars);
11277 	dtrace_speculation_clean(state);
11278 }
11279 
11280 static void
11281 dtrace_state_deadman(dtrace_state_t *state)
11282 {
11283 	hrtime_t now;
11284 
11285 	dtrace_sync();
11286 
11287 	now = dtrace_gethrtime();
11288 
11289 	if (state != dtrace_anon.dta_state &&
11290 	    now - state->dts_laststatus >= dtrace_deadman_user)
11291 		return;
11292 
11293 	/*
11294 	 * We must be sure that dts_alive never appears to be less than the
11295 	 * value upon entry to dtrace_state_deadman(), and because we lack a
11296 	 * dtrace_cas64(), we cannot store to it atomically.  We thus instead
11297 	 * store INT64_MAX to it, followed by a memory barrier, followed by
11298 	 * the new value.  This assures that dts_alive never appears to be
11299 	 * less than its true value, regardless of the order in which the
11300 	 * stores to the underlying storage are issued.
11301 	 */
11302 	state->dts_alive = INT64_MAX;
11303 	dtrace_membar_producer();
11304 	state->dts_alive = now;
11305 }
11306 
11307 dtrace_state_t *
11308 dtrace_state_create(dev_t *devp, cred_t *cr)
11309 {
11310 	minor_t minor;
11311 	major_t major;
11312 	char c[30];
11313 	dtrace_state_t *state;
11314 	dtrace_optval_t *opt;
11315 	int bufsize = NCPU * sizeof (dtrace_buffer_t), i;
11316 
11317 	ASSERT(MUTEX_HELD(&dtrace_lock));
11318 	ASSERT(MUTEX_HELD(&cpu_lock));
11319 
11320 	minor = (minor_t)(uintptr_t)vmem_alloc(dtrace_minor, 1,
11321 	    VM_BESTFIT | VM_SLEEP);
11322 
11323 	if (ddi_soft_state_zalloc(dtrace_softstate, minor) != DDI_SUCCESS) {
11324 		vmem_free(dtrace_minor, (void *)(uintptr_t)minor, 1);
11325 		return (NULL);
11326 	}
11327 
11328 	state = ddi_get_soft_state(dtrace_softstate, minor);
11329 	state->dts_epid = DTRACE_EPIDNONE + 1;
11330 
11331 	(void) snprintf(c, sizeof (c), "dtrace_aggid_%d", minor);
11332 	state->dts_aggid_arena = vmem_create(c, (void *)1, UINT32_MAX, 1,
11333 	    NULL, NULL, NULL, 0, VM_SLEEP | VMC_IDENTIFIER);
11334 
11335 	if (devp != NULL) {
11336 		major = getemajor(*devp);
11337 	} else {
11338 		major = ddi_driver_major(dtrace_devi);
11339 	}
11340 
11341 	state->dts_dev = makedevice(major, minor);
11342 
11343 	if (devp != NULL)
11344 		*devp = state->dts_dev;
11345 
11346 	/*
11347 	 * We allocate NCPU buffers.  On the one hand, this can be quite
11348 	 * a bit of memory per instance (nearly 36K on a Starcat).  On the
11349 	 * other hand, it saves an additional memory reference in the probe
11350 	 * path.
11351 	 */
11352 	state->dts_buffer = kmem_zalloc(bufsize, KM_SLEEP);
11353 	state->dts_aggbuffer = kmem_zalloc(bufsize, KM_SLEEP);
11354 	state->dts_cleaner = CYCLIC_NONE;
11355 	state->dts_deadman = CYCLIC_NONE;
11356 	state->dts_vstate.dtvs_state = state;
11357 
11358 	for (i = 0; i < DTRACEOPT_MAX; i++)
11359 		state->dts_options[i] = DTRACEOPT_UNSET;
11360 
11361 	/*
11362 	 * Set the default options.
11363 	 */
11364 	opt = state->dts_options;
11365 	opt[DTRACEOPT_BUFPOLICY] = DTRACEOPT_BUFPOLICY_SWITCH;
11366 	opt[DTRACEOPT_BUFRESIZE] = DTRACEOPT_BUFRESIZE_AUTO;
11367 	opt[DTRACEOPT_NSPEC] = dtrace_nspec_default;
11368 	opt[DTRACEOPT_SPECSIZE] = dtrace_specsize_default;
11369 	opt[DTRACEOPT_CPU] = (dtrace_optval_t)DTRACE_CPUALL;
11370 	opt[DTRACEOPT_STRSIZE] = dtrace_strsize_default;
11371 	opt[DTRACEOPT_STACKFRAMES] = dtrace_stackframes_default;
11372 	opt[DTRACEOPT_USTACKFRAMES] = dtrace_ustackframes_default;
11373 	opt[DTRACEOPT_CLEANRATE] = dtrace_cleanrate_default;
11374 	opt[DTRACEOPT_AGGRATE] = dtrace_aggrate_default;
11375 	opt[DTRACEOPT_SWITCHRATE] = dtrace_switchrate_default;
11376 	opt[DTRACEOPT_STATUSRATE] = dtrace_statusrate_default;
11377 	opt[DTRACEOPT_JSTACKFRAMES] = dtrace_jstackframes_default;
11378 	opt[DTRACEOPT_JSTACKSTRSIZE] = dtrace_jstackstrsize_default;
11379 
11380 	state->dts_activity = DTRACE_ACTIVITY_INACTIVE;
11381 
11382 	/*
11383 	 * Depending on the user credentials, we set flag bits which alter probe
11384 	 * visibility or the amount of destructiveness allowed.  In the case of
11385 	 * actual anonymous tracing, or the possession of all privileges, all of
11386 	 * the normal checks are bypassed.
11387 	 */
11388 	if (cr == NULL || PRIV_POLICY_ONLY(cr, PRIV_ALL, B_FALSE)) {
11389 		state->dts_cred.dcr_visible = DTRACE_CRV_ALL;
11390 		state->dts_cred.dcr_action = DTRACE_CRA_ALL;
11391 	} else {
11392 		/*
11393 		 * Set up the credentials for this instantiation.  We take a
11394 		 * hold on the credential to prevent it from disappearing on
11395 		 * us; this in turn prevents the zone_t referenced by this
11396 		 * credential from disappearing.  This means that we can
11397 		 * examine the credential and the zone from probe context.
11398 		 */
11399 		crhold(cr);
11400 		state->dts_cred.dcr_cred = cr;
11401 
11402 		/*
11403 		 * CRA_PROC means "we have *some* privilege for dtrace" and
11404 		 * unlocks the use of variables like pid, zonename, etc.
11405 		 */
11406 		if (PRIV_POLICY_ONLY(cr, PRIV_DTRACE_USER, B_FALSE) ||
11407 		    PRIV_POLICY_ONLY(cr, PRIV_DTRACE_PROC, B_FALSE)) {
11408 			state->dts_cred.dcr_action |= DTRACE_CRA_PROC;
11409 		}
11410 
11411 		/*
11412 		 * dtrace_user allows use of syscall and profile providers.
11413 		 * If the user also has proc_owner and/or proc_zone, we
11414 		 * extend the scope to include additional visibility and
11415 		 * destructive power.
11416 		 */
11417 		if (PRIV_POLICY_ONLY(cr, PRIV_DTRACE_USER, B_FALSE)) {
11418 			if (PRIV_POLICY_ONLY(cr, PRIV_PROC_OWNER, B_FALSE)) {
11419 				state->dts_cred.dcr_visible |=
11420 				    DTRACE_CRV_ALLPROC;
11421 
11422 				state->dts_cred.dcr_action |=
11423 				    DTRACE_CRA_PROC_DESTRUCTIVE_ALLUSER;
11424 			}
11425 
11426 			if (PRIV_POLICY_ONLY(cr, PRIV_PROC_ZONE, B_FALSE)) {
11427 				state->dts_cred.dcr_visible |=
11428 				    DTRACE_CRV_ALLZONE;
11429 
11430 				state->dts_cred.dcr_action |=
11431 				    DTRACE_CRA_PROC_DESTRUCTIVE_ALLZONE;
11432 			}
11433 
11434 			/*
11435 			 * If we have all privs in whatever zone this is,
11436 			 * we can do destructive things to processes which
11437 			 * have altered credentials.
11438 			 */
11439 			if (priv_isequalset(priv_getset(cr, PRIV_EFFECTIVE),
11440 			    cr->cr_zone->zone_privset)) {
11441 				state->dts_cred.dcr_action |=
11442 				    DTRACE_CRA_PROC_DESTRUCTIVE_CREDCHG;
11443 			}
11444 		}
11445 
11446 		/*
11447 		 * Holding the dtrace_kernel privilege also implies that
11448 		 * the user has the dtrace_user privilege from a visibility
11449 		 * perspective.  But without further privileges, some
11450 		 * destructive actions are not available.
11451 		 */
11452 		if (PRIV_POLICY_ONLY(cr, PRIV_DTRACE_KERNEL, B_FALSE)) {
11453 			/*
11454 			 * Make all probes in all zones visible.  However,
11455 			 * this doesn't mean that all actions become available
11456 			 * to all zones.
11457 			 */
11458 			state->dts_cred.dcr_visible |= DTRACE_CRV_KERNEL |
11459 			    DTRACE_CRV_ALLPROC | DTRACE_CRV_ALLZONE;
11460 
11461 			state->dts_cred.dcr_action |= DTRACE_CRA_KERNEL |
11462 			    DTRACE_CRA_PROC;
11463 			/*
11464 			 * Holding proc_owner means that destructive actions
11465 			 * for *this* zone are allowed.
11466 			 */
11467 			if (PRIV_POLICY_ONLY(cr, PRIV_PROC_OWNER, B_FALSE))
11468 				state->dts_cred.dcr_action |=
11469 				    DTRACE_CRA_PROC_DESTRUCTIVE_ALLUSER;
11470 
11471 			/*
11472 			 * Holding proc_zone means that destructive actions
11473 			 * for this user/group ID in all zones is allowed.
11474 			 */
11475 			if (PRIV_POLICY_ONLY(cr, PRIV_PROC_ZONE, B_FALSE))
11476 				state->dts_cred.dcr_action |=
11477 				    DTRACE_CRA_PROC_DESTRUCTIVE_ALLZONE;
11478 
11479 			/*
11480 			 * If we have all privs in whatever zone this is,
11481 			 * we can do destructive things to processes which
11482 			 * have altered credentials.
11483 			 */
11484 			if (priv_isequalset(priv_getset(cr, PRIV_EFFECTIVE),
11485 			    cr->cr_zone->zone_privset)) {
11486 				state->dts_cred.dcr_action |=
11487 				    DTRACE_CRA_PROC_DESTRUCTIVE_CREDCHG;
11488 			}
11489 		}
11490 
11491 		/*
11492 		 * Holding the dtrace_proc privilege gives control over fasttrap
11493 		 * and pid providers.  We need to grant wider destructive
11494 		 * privileges in the event that the user has proc_owner and/or
11495 		 * proc_zone.
11496 		 */
11497 		if (PRIV_POLICY_ONLY(cr, PRIV_DTRACE_PROC, B_FALSE)) {
11498 			if (PRIV_POLICY_ONLY(cr, PRIV_PROC_OWNER, B_FALSE))
11499 				state->dts_cred.dcr_action |=
11500 				    DTRACE_CRA_PROC_DESTRUCTIVE_ALLUSER;
11501 
11502 			if (PRIV_POLICY_ONLY(cr, PRIV_PROC_ZONE, B_FALSE))
11503 				state->dts_cred.dcr_action |=
11504 				    DTRACE_CRA_PROC_DESTRUCTIVE_ALLZONE;
11505 		}
11506 	}
11507 
11508 	return (state);
11509 }
11510 
11511 static int
11512 dtrace_state_buffer(dtrace_state_t *state, dtrace_buffer_t *buf, int which)
11513 {
11514 	dtrace_optval_t *opt = state->dts_options, size;
11515 	processorid_t cpu;
11516 	int flags = 0, rval;
11517 
11518 	ASSERT(MUTEX_HELD(&dtrace_lock));
11519 	ASSERT(MUTEX_HELD(&cpu_lock));
11520 	ASSERT(which < DTRACEOPT_MAX);
11521 	ASSERT(state->dts_activity == DTRACE_ACTIVITY_INACTIVE ||
11522 	    (state == dtrace_anon.dta_state &&
11523 	    state->dts_activity == DTRACE_ACTIVITY_ACTIVE));
11524 
11525 	if (opt[which] == DTRACEOPT_UNSET || opt[which] == 0)
11526 		return (0);
11527 
11528 	if (opt[DTRACEOPT_CPU] != DTRACEOPT_UNSET)
11529 		cpu = opt[DTRACEOPT_CPU];
11530 
11531 	if (which == DTRACEOPT_SPECSIZE)
11532 		flags |= DTRACEBUF_NOSWITCH;
11533 
11534 	if (which == DTRACEOPT_BUFSIZE) {
11535 		if (opt[DTRACEOPT_BUFPOLICY] == DTRACEOPT_BUFPOLICY_RING)
11536 			flags |= DTRACEBUF_RING;
11537 
11538 		if (opt[DTRACEOPT_BUFPOLICY] == DTRACEOPT_BUFPOLICY_FILL)
11539 			flags |= DTRACEBUF_FILL;
11540 
11541 		if (state != dtrace_anon.dta_state ||
11542 		    state->dts_activity != DTRACE_ACTIVITY_ACTIVE)
11543 			flags |= DTRACEBUF_INACTIVE;
11544 	}
11545 
11546 	for (size = opt[which]; size >= sizeof (uint64_t); size >>= 1) {
11547 		/*
11548 		 * The size must be 8-byte aligned.  If the size is not 8-byte
11549 		 * aligned, drop it down by the difference.
11550 		 */
11551 		if (size & (sizeof (uint64_t) - 1))
11552 			size -= size & (sizeof (uint64_t) - 1);
11553 
11554 		if (size < state->dts_reserve) {
11555 			/*
11556 			 * Buffers always must be large enough to accommodate
11557 			 * their prereserved space.  We return E2BIG instead
11558 			 * of ENOMEM in this case to allow for user-level
11559 			 * software to differentiate the cases.
11560 			 */
11561 			return (E2BIG);
11562 		}
11563 
11564 		rval = dtrace_buffer_alloc(buf, size, flags, cpu);
11565 
11566 		if (rval != ENOMEM) {
11567 			opt[which] = size;
11568 			return (rval);
11569 		}
11570 
11571 		if (opt[DTRACEOPT_BUFRESIZE] == DTRACEOPT_BUFRESIZE_MANUAL)
11572 			return (rval);
11573 	}
11574 
11575 	return (ENOMEM);
11576 }
11577 
11578 static int
11579 dtrace_state_buffers(dtrace_state_t *state)
11580 {
11581 	dtrace_speculation_t *spec = state->dts_speculations;
11582 	int rval, i;
11583 
11584 	if ((rval = dtrace_state_buffer(state, state->dts_buffer,
11585 	    DTRACEOPT_BUFSIZE)) != 0)
11586 		return (rval);
11587 
11588 	if ((rval = dtrace_state_buffer(state, state->dts_aggbuffer,
11589 	    DTRACEOPT_AGGSIZE)) != 0)
11590 		return (rval);
11591 
11592 	for (i = 0; i < state->dts_nspeculations; i++) {
11593 		if ((rval = dtrace_state_buffer(state,
11594 		    spec[i].dtsp_buffer, DTRACEOPT_SPECSIZE)) != 0)
11595 			return (rval);
11596 	}
11597 
11598 	return (0);
11599 }
11600 
11601 static void
11602 dtrace_state_prereserve(dtrace_state_t *state)
11603 {
11604 	dtrace_ecb_t *ecb;
11605 	dtrace_probe_t *probe;
11606 
11607 	state->dts_reserve = 0;
11608 
11609 	if (state->dts_options[DTRACEOPT_BUFPOLICY] != DTRACEOPT_BUFPOLICY_FILL)
11610 		return;
11611 
11612 	/*
11613 	 * If our buffer policy is a "fill" buffer policy, we need to set the
11614 	 * prereserved space to be the space required by the END probes.
11615 	 */
11616 	probe = dtrace_probes[dtrace_probeid_end - 1];
11617 	ASSERT(probe != NULL);
11618 
11619 	for (ecb = probe->dtpr_ecb; ecb != NULL; ecb = ecb->dte_next) {
11620 		if (ecb->dte_state != state)
11621 			continue;
11622 
11623 		state->dts_reserve += ecb->dte_needed + ecb->dte_alignment;
11624 	}
11625 }
11626 
11627 static int
11628 dtrace_state_go(dtrace_state_t *state, processorid_t *cpu)
11629 {
11630 	dtrace_optval_t *opt = state->dts_options, sz, nspec;
11631 	dtrace_speculation_t *spec;
11632 	dtrace_buffer_t *buf;
11633 	cyc_handler_t hdlr;
11634 	cyc_time_t when;
11635 	int rval = 0, i, bufsize = NCPU * sizeof (dtrace_buffer_t);
11636 	dtrace_icookie_t cookie;
11637 
11638 	mutex_enter(&cpu_lock);
11639 	mutex_enter(&dtrace_lock);
11640 
11641 	if (state->dts_activity != DTRACE_ACTIVITY_INACTIVE) {
11642 		rval = EBUSY;
11643 		goto out;
11644 	}
11645 
11646 	/*
11647 	 * Before we can perform any checks, we must prime all of the
11648 	 * retained enablings that correspond to this state.
11649 	 */
11650 	dtrace_enabling_prime(state);
11651 
11652 	if (state->dts_destructive && !state->dts_cred.dcr_destructive) {
11653 		rval = EACCES;
11654 		goto out;
11655 	}
11656 
11657 	dtrace_state_prereserve(state);
11658 
11659 	/*
11660 	 * Now we want to do is try to allocate our speculations.
11661 	 * We do not automatically resize the number of speculations; if
11662 	 * this fails, we will fail the operation.
11663 	 */
11664 	nspec = opt[DTRACEOPT_NSPEC];
11665 	ASSERT(nspec != DTRACEOPT_UNSET);
11666 
11667 	if (nspec > INT_MAX) {
11668 		rval = ENOMEM;
11669 		goto out;
11670 	}
11671 
11672 	spec = kmem_zalloc(nspec * sizeof (dtrace_speculation_t), KM_NOSLEEP);
11673 
11674 	if (spec == NULL) {
11675 		rval = ENOMEM;
11676 		goto out;
11677 	}
11678 
11679 	state->dts_speculations = spec;
11680 	state->dts_nspeculations = (int)nspec;
11681 
11682 	for (i = 0; i < nspec; i++) {
11683 		if ((buf = kmem_zalloc(bufsize, KM_NOSLEEP)) == NULL) {
11684 			rval = ENOMEM;
11685 			goto err;
11686 		}
11687 
11688 		spec[i].dtsp_buffer = buf;
11689 	}
11690 
11691 	if (opt[DTRACEOPT_GRABANON] != DTRACEOPT_UNSET) {
11692 		if (dtrace_anon.dta_state == NULL) {
11693 			rval = ENOENT;
11694 			goto out;
11695 		}
11696 
11697 		if (state->dts_necbs != 0) {
11698 			rval = EALREADY;
11699 			goto out;
11700 		}
11701 
11702 		state->dts_anon = dtrace_anon_grab();
11703 		ASSERT(state->dts_anon != NULL);
11704 		state = state->dts_anon;
11705 
11706 		/*
11707 		 * We want "grabanon" to be set in the grabbed state, so we'll
11708 		 * copy that option value from the grabbing state into the
11709 		 * grabbed state.
11710 		 */
11711 		state->dts_options[DTRACEOPT_GRABANON] =
11712 		    opt[DTRACEOPT_GRABANON];
11713 
11714 		*cpu = dtrace_anon.dta_beganon;
11715 
11716 		/*
11717 		 * If the anonymous state is active (as it almost certainly
11718 		 * is if the anonymous enabling ultimately matched anything),
11719 		 * we don't allow any further option processing -- but we
11720 		 * don't return failure.
11721 		 */
11722 		if (state->dts_activity != DTRACE_ACTIVITY_INACTIVE)
11723 			goto out;
11724 	}
11725 
11726 	if (opt[DTRACEOPT_AGGSIZE] != DTRACEOPT_UNSET &&
11727 	    opt[DTRACEOPT_AGGSIZE] != 0) {
11728 		if (state->dts_aggregations == NULL) {
11729 			/*
11730 			 * We're not going to create an aggregation buffer
11731 			 * because we don't have any ECBs that contain
11732 			 * aggregations -- set this option to 0.
11733 			 */
11734 			opt[DTRACEOPT_AGGSIZE] = 0;
11735 		} else {
11736 			/*
11737 			 * If we have an aggregation buffer, we must also have
11738 			 * a buffer to use as scratch.
11739 			 */
11740 			if (opt[DTRACEOPT_BUFSIZE] == DTRACEOPT_UNSET ||
11741 			    opt[DTRACEOPT_BUFSIZE] < state->dts_needed) {
11742 				opt[DTRACEOPT_BUFSIZE] = state->dts_needed;
11743 			}
11744 		}
11745 	}
11746 
11747 	if (opt[DTRACEOPT_SPECSIZE] != DTRACEOPT_UNSET &&
11748 	    opt[DTRACEOPT_SPECSIZE] != 0) {
11749 		if (!state->dts_speculates) {
11750 			/*
11751 			 * We're not going to create speculation buffers
11752 			 * because we don't have any ECBs that actually
11753 			 * speculate -- set the speculation size to 0.
11754 			 */
11755 			opt[DTRACEOPT_SPECSIZE] = 0;
11756 		}
11757 	}
11758 
11759 	/*
11760 	 * The bare minimum size for any buffer that we're actually going to
11761 	 * do anything to is sizeof (uint64_t).
11762 	 */
11763 	sz = sizeof (uint64_t);
11764 
11765 	if ((state->dts_needed != 0 && opt[DTRACEOPT_BUFSIZE] < sz) ||
11766 	    (state->dts_speculates && opt[DTRACEOPT_SPECSIZE] < sz) ||
11767 	    (state->dts_aggregations != NULL && opt[DTRACEOPT_AGGSIZE] < sz)) {
11768 		/*
11769 		 * A buffer size has been explicitly set to 0 (or to a size
11770 		 * that will be adjusted to 0) and we need the space -- we
11771 		 * need to return failure.  We return ENOSPC to differentiate
11772 		 * it from failing to allocate a buffer due to failure to meet
11773 		 * the reserve (for which we return E2BIG).
11774 		 */
11775 		rval = ENOSPC;
11776 		goto out;
11777 	}
11778 
11779 	if ((rval = dtrace_state_buffers(state)) != 0)
11780 		goto err;
11781 
11782 	if ((sz = opt[DTRACEOPT_DYNVARSIZE]) == DTRACEOPT_UNSET)
11783 		sz = dtrace_dstate_defsize;
11784 
11785 	do {
11786 		rval = dtrace_dstate_init(&state->dts_vstate.dtvs_dynvars, sz);
11787 
11788 		if (rval == 0)
11789 			break;
11790 
11791 		if (opt[DTRACEOPT_BUFRESIZE] == DTRACEOPT_BUFRESIZE_MANUAL)
11792 			goto err;
11793 	} while (sz >>= 1);
11794 
11795 	opt[DTRACEOPT_DYNVARSIZE] = sz;
11796 
11797 	if (rval != 0)
11798 		goto err;
11799 
11800 	if (opt[DTRACEOPT_STATUSRATE] > dtrace_statusrate_max)
11801 		opt[DTRACEOPT_STATUSRATE] = dtrace_statusrate_max;
11802 
11803 	if (opt[DTRACEOPT_CLEANRATE] == 0)
11804 		opt[DTRACEOPT_CLEANRATE] = dtrace_cleanrate_max;
11805 
11806 	if (opt[DTRACEOPT_CLEANRATE] < dtrace_cleanrate_min)
11807 		opt[DTRACEOPT_CLEANRATE] = dtrace_cleanrate_min;
11808 
11809 	if (opt[DTRACEOPT_CLEANRATE] > dtrace_cleanrate_max)
11810 		opt[DTRACEOPT_CLEANRATE] = dtrace_cleanrate_max;
11811 
11812 	hdlr.cyh_func = (cyc_func_t)dtrace_state_clean;
11813 	hdlr.cyh_arg = state;
11814 	hdlr.cyh_level = CY_LOW_LEVEL;
11815 
11816 	when.cyt_when = 0;
11817 	when.cyt_interval = opt[DTRACEOPT_CLEANRATE];
11818 
11819 	state->dts_cleaner = cyclic_add(&hdlr, &when);
11820 
11821 	hdlr.cyh_func = (cyc_func_t)dtrace_state_deadman;
11822 	hdlr.cyh_arg = state;
11823 	hdlr.cyh_level = CY_LOW_LEVEL;
11824 
11825 	when.cyt_when = 0;
11826 	when.cyt_interval = dtrace_deadman_interval;
11827 
11828 	state->dts_alive = state->dts_laststatus = dtrace_gethrtime();
11829 	state->dts_deadman = cyclic_add(&hdlr, &when);
11830 
11831 	state->dts_activity = DTRACE_ACTIVITY_WARMUP;
11832 
11833 	/*
11834 	 * Now it's time to actually fire the BEGIN probe.  We need to disable
11835 	 * interrupts here both to record the CPU on which we fired the BEGIN
11836 	 * probe (the data from this CPU will be processed first at user
11837 	 * level) and to manually activate the buffer for this CPU.
11838 	 */
11839 	cookie = dtrace_interrupt_disable();
11840 	*cpu = CPU->cpu_id;
11841 	ASSERT(state->dts_buffer[*cpu].dtb_flags & DTRACEBUF_INACTIVE);
11842 	state->dts_buffer[*cpu].dtb_flags &= ~DTRACEBUF_INACTIVE;
11843 
11844 	dtrace_probe(dtrace_probeid_begin,
11845 	    (uint64_t)(uintptr_t)state, 0, 0, 0, 0);
11846 	dtrace_interrupt_enable(cookie);
11847 	/*
11848 	 * We may have had an exit action from a BEGIN probe; only change our
11849 	 * state to ACTIVE if we're still in WARMUP.
11850 	 */
11851 	ASSERT(state->dts_activity == DTRACE_ACTIVITY_WARMUP ||
11852 	    state->dts_activity == DTRACE_ACTIVITY_DRAINING);
11853 
11854 	if (state->dts_activity == DTRACE_ACTIVITY_WARMUP)
11855 		state->dts_activity = DTRACE_ACTIVITY_ACTIVE;
11856 
11857 	/*
11858 	 * Regardless of whether or not now we're in ACTIVE or DRAINING, we
11859 	 * want each CPU to transition its principal buffer out of the
11860 	 * INACTIVE state.  Doing this assures that no CPU will suddenly begin
11861 	 * processing an ECB halfway down a probe's ECB chain; all CPUs will
11862 	 * atomically transition from processing none of a state's ECBs to
11863 	 * processing all of them.
11864 	 */
11865 	dtrace_xcall(DTRACE_CPUALL,
11866 	    (dtrace_xcall_t)dtrace_buffer_activate, state);
11867 	goto out;
11868 
11869 err:
11870 	dtrace_buffer_free(state->dts_buffer);
11871 	dtrace_buffer_free(state->dts_aggbuffer);
11872 
11873 	if ((nspec = state->dts_nspeculations) == 0) {
11874 		ASSERT(state->dts_speculations == NULL);
11875 		goto out;
11876 	}
11877 
11878 	spec = state->dts_speculations;
11879 	ASSERT(spec != NULL);
11880 
11881 	for (i = 0; i < state->dts_nspeculations; i++) {
11882 		if ((buf = spec[i].dtsp_buffer) == NULL)
11883 			break;
11884 
11885 		dtrace_buffer_free(buf);
11886 		kmem_free(buf, bufsize);
11887 	}
11888 
11889 	kmem_free(spec, nspec * sizeof (dtrace_speculation_t));
11890 	state->dts_nspeculations = 0;
11891 	state->dts_speculations = NULL;
11892 
11893 out:
11894 	mutex_exit(&dtrace_lock);
11895 	mutex_exit(&cpu_lock);
11896 
11897 	return (rval);
11898 }
11899 
11900 static int
11901 dtrace_state_stop(dtrace_state_t *state, processorid_t *cpu)
11902 {
11903 	dtrace_icookie_t cookie;
11904 
11905 	ASSERT(MUTEX_HELD(&dtrace_lock));
11906 
11907 	if (state->dts_activity != DTRACE_ACTIVITY_ACTIVE &&
11908 	    state->dts_activity != DTRACE_ACTIVITY_DRAINING)
11909 		return (EINVAL);
11910 
11911 	/*
11912 	 * We'll set the activity to DTRACE_ACTIVITY_DRAINING, and issue a sync
11913 	 * to be sure that every CPU has seen it.  See below for the details
11914 	 * on why this is done.
11915 	 */
11916 	state->dts_activity = DTRACE_ACTIVITY_DRAINING;
11917 	dtrace_sync();
11918 
11919 	/*
11920 	 * By this point, it is impossible for any CPU to be still processing
11921 	 * with DTRACE_ACTIVITY_ACTIVE.  We can thus set our activity to
11922 	 * DTRACE_ACTIVITY_COOLDOWN and know that we're not racing with any
11923 	 * other CPU in dtrace_buffer_reserve().  This allows dtrace_probe()
11924 	 * and callees to know that the activity is DTRACE_ACTIVITY_COOLDOWN
11925 	 * iff we're in the END probe.
11926 	 */
11927 	state->dts_activity = DTRACE_ACTIVITY_COOLDOWN;
11928 	dtrace_sync();
11929 	ASSERT(state->dts_activity == DTRACE_ACTIVITY_COOLDOWN);
11930 
11931 	/*
11932 	 * Finally, we can release the reserve and call the END probe.  We
11933 	 * disable interrupts across calling the END probe to allow us to
11934 	 * return the CPU on which we actually called the END probe.  This
11935 	 * allows user-land to be sure that this CPU's principal buffer is
11936 	 * processed last.
11937 	 */
11938 	state->dts_reserve = 0;
11939 
11940 	cookie = dtrace_interrupt_disable();
11941 	*cpu = CPU->cpu_id;
11942 	dtrace_probe(dtrace_probeid_end,
11943 	    (uint64_t)(uintptr_t)state, 0, 0, 0, 0);
11944 	dtrace_interrupt_enable(cookie);
11945 
11946 	state->dts_activity = DTRACE_ACTIVITY_STOPPED;
11947 	dtrace_sync();
11948 
11949 	return (0);
11950 }
11951 
11952 static int
11953 dtrace_state_option(dtrace_state_t *state, dtrace_optid_t option,
11954     dtrace_optval_t val)
11955 {
11956 	ASSERT(MUTEX_HELD(&dtrace_lock));
11957 
11958 	if (state->dts_activity != DTRACE_ACTIVITY_INACTIVE)
11959 		return (EBUSY);
11960 
11961 	if (option >= DTRACEOPT_MAX)
11962 		return (EINVAL);
11963 
11964 	if (option != DTRACEOPT_CPU && val < 0)
11965 		return (EINVAL);
11966 
11967 	switch (option) {
11968 	case DTRACEOPT_DESTRUCTIVE:
11969 		if (dtrace_destructive_disallow)
11970 			return (EACCES);
11971 
11972 		state->dts_cred.dcr_destructive = 1;
11973 		break;
11974 
11975 	case DTRACEOPT_BUFSIZE:
11976 	case DTRACEOPT_DYNVARSIZE:
11977 	case DTRACEOPT_AGGSIZE:
11978 	case DTRACEOPT_SPECSIZE:
11979 	case DTRACEOPT_STRSIZE:
11980 		if (val < 0)
11981 			return (EINVAL);
11982 
11983 		if (val >= LONG_MAX) {
11984 			/*
11985 			 * If this is an otherwise negative value, set it to
11986 			 * the highest multiple of 128m less than LONG_MAX.
11987 			 * Technically, we're adjusting the size without
11988 			 * regard to the buffer resizing policy, but in fact,
11989 			 * this has no effect -- if we set the buffer size to
11990 			 * ~LONG_MAX and the buffer policy is ultimately set to
11991 			 * be "manual", the buffer allocation is guaranteed to
11992 			 * fail, if only because the allocation requires two
11993 			 * buffers.  (We set the the size to the highest
11994 			 * multiple of 128m because it ensures that the size
11995 			 * will remain a multiple of a megabyte when
11996 			 * repeatedly halved -- all the way down to 15m.)
11997 			 */
11998 			val = LONG_MAX - (1 << 27) + 1;
11999 		}
12000 	}
12001 
12002 	state->dts_options[option] = val;
12003 
12004 	return (0);
12005 }
12006 
12007 static void
12008 dtrace_state_destroy(dtrace_state_t *state)
12009 {
12010 	dtrace_ecb_t *ecb;
12011 	dtrace_vstate_t *vstate = &state->dts_vstate;
12012 	minor_t minor = getminor(state->dts_dev);
12013 	int i, bufsize = NCPU * sizeof (dtrace_buffer_t);
12014 	dtrace_speculation_t *spec = state->dts_speculations;
12015 	int nspec = state->dts_nspeculations;
12016 	uint32_t match;
12017 
12018 	ASSERT(MUTEX_HELD(&dtrace_lock));
12019 	ASSERT(MUTEX_HELD(&cpu_lock));
12020 
12021 	/*
12022 	 * First, retract any retained enablings for this state.
12023 	 */
12024 	dtrace_enabling_retract(state);
12025 	ASSERT(state->dts_nretained == 0);
12026 
12027 	if (state->dts_activity == DTRACE_ACTIVITY_ACTIVE ||
12028 	    state->dts_activity == DTRACE_ACTIVITY_DRAINING) {
12029 		/*
12030 		 * We have managed to come into dtrace_state_destroy() on a
12031 		 * hot enabling -- almost certainly because of a disorderly
12032 		 * shutdown of a consumer.  (That is, a consumer that is
12033 		 * exiting without having called dtrace_stop().) In this case,
12034 		 * we're going to set our activity to be KILLED, and then
12035 		 * issue a sync to be sure that everyone is out of probe
12036 		 * context before we start blowing away ECBs.
12037 		 */
12038 		state->dts_activity = DTRACE_ACTIVITY_KILLED;
12039 		dtrace_sync();
12040 	}
12041 
12042 	/*
12043 	 * Release the credential hold we took in dtrace_state_create().
12044 	 */
12045 	if (state->dts_cred.dcr_cred != NULL)
12046 		crfree(state->dts_cred.dcr_cred);
12047 
12048 	/*
12049 	 * Now we can safely disable and destroy any enabled probes.  Because
12050 	 * any DTRACE_PRIV_KERNEL probes may actually be slowing our progress
12051 	 * (especially if they're all enabled), we take two passes through the
12052 	 * ECBs:  in the first, we disable just DTRACE_PRIV_KERNEL probes, and
12053 	 * in the second we disable whatever is left over.
12054 	 */
12055 	for (match = DTRACE_PRIV_KERNEL; ; match = 0) {
12056 		for (i = 0; i < state->dts_necbs; i++) {
12057 			if ((ecb = state->dts_ecbs[i]) == NULL)
12058 				continue;
12059 
12060 			if (match && ecb->dte_probe != NULL) {
12061 				dtrace_probe_t *probe = ecb->dte_probe;
12062 				dtrace_provider_t *prov = probe->dtpr_provider;
12063 
12064 				if (!(prov->dtpv_priv.dtpp_flags & match))
12065 					continue;
12066 			}
12067 
12068 			dtrace_ecb_disable(ecb);
12069 			dtrace_ecb_destroy(ecb);
12070 		}
12071 
12072 		if (!match)
12073 			break;
12074 	}
12075 
12076 	/*
12077 	 * Before we free the buffers, perform one more sync to assure that
12078 	 * every CPU is out of probe context.
12079 	 */
12080 	dtrace_sync();
12081 
12082 	dtrace_buffer_free(state->dts_buffer);
12083 	dtrace_buffer_free(state->dts_aggbuffer);
12084 
12085 	for (i = 0; i < nspec; i++)
12086 		dtrace_buffer_free(spec[i].dtsp_buffer);
12087 
12088 	if (state->dts_cleaner != CYCLIC_NONE)
12089 		cyclic_remove(state->dts_cleaner);
12090 
12091 	if (state->dts_deadman != CYCLIC_NONE)
12092 		cyclic_remove(state->dts_deadman);
12093 
12094 	dtrace_dstate_fini(&vstate->dtvs_dynvars);
12095 	dtrace_vstate_fini(vstate);
12096 	kmem_free(state->dts_ecbs, state->dts_necbs * sizeof (dtrace_ecb_t *));
12097 
12098 	if (state->dts_aggregations != NULL) {
12099 #ifdef DEBUG
12100 		for (i = 0; i < state->dts_naggregations; i++)
12101 			ASSERT(state->dts_aggregations[i] == NULL);
12102 #endif
12103 		ASSERT(state->dts_naggregations > 0);
12104 		kmem_free(state->dts_aggregations,
12105 		    state->dts_naggregations * sizeof (dtrace_aggregation_t *));
12106 	}
12107 
12108 	kmem_free(state->dts_buffer, bufsize);
12109 	kmem_free(state->dts_aggbuffer, bufsize);
12110 
12111 	for (i = 0; i < nspec; i++)
12112 		kmem_free(spec[i].dtsp_buffer, bufsize);
12113 
12114 	kmem_free(spec, nspec * sizeof (dtrace_speculation_t));
12115 
12116 	dtrace_format_destroy(state);
12117 
12118 	vmem_destroy(state->dts_aggid_arena);
12119 	ddi_soft_state_free(dtrace_softstate, minor);
12120 	vmem_free(dtrace_minor, (void *)(uintptr_t)minor, 1);
12121 }
12122 
12123 /*
12124  * DTrace Anonymous Enabling Functions
12125  */
12126 static dtrace_state_t *
12127 dtrace_anon_grab(void)
12128 {
12129 	dtrace_state_t *state;
12130 
12131 	ASSERT(MUTEX_HELD(&dtrace_lock));
12132 
12133 	if ((state = dtrace_anon.dta_state) == NULL) {
12134 		ASSERT(dtrace_anon.dta_enabling == NULL);
12135 		return (NULL);
12136 	}
12137 
12138 	ASSERT(dtrace_anon.dta_enabling != NULL);
12139 	ASSERT(dtrace_retained != NULL);
12140 
12141 	dtrace_enabling_destroy(dtrace_anon.dta_enabling);
12142 	dtrace_anon.dta_enabling = NULL;
12143 	dtrace_anon.dta_state = NULL;
12144 
12145 	return (state);
12146 }
12147 
12148 static void
12149 dtrace_anon_property(void)
12150 {
12151 	int i, rv;
12152 	dtrace_state_t *state;
12153 	dof_hdr_t *dof;
12154 	char c[32];		/* enough for "dof-data-" + digits */
12155 
12156 	ASSERT(MUTEX_HELD(&dtrace_lock));
12157 	ASSERT(MUTEX_HELD(&cpu_lock));
12158 
12159 	for (i = 0; ; i++) {
12160 		(void) snprintf(c, sizeof (c), "dof-data-%d", i);
12161 
12162 		dtrace_err_verbose = 1;
12163 
12164 		if ((dof = dtrace_dof_property(c)) == NULL) {
12165 			dtrace_err_verbose = 0;
12166 			break;
12167 		}
12168 
12169 		/*
12170 		 * We want to create anonymous state, so we need to transition
12171 		 * the kernel debugger to indicate that DTrace is active.  If
12172 		 * this fails (e.g. because the debugger has modified text in
12173 		 * some way), we won't continue with the processing.
12174 		 */
12175 		if (kdi_dtrace_set(KDI_DTSET_DTRACE_ACTIVATE) != 0) {
12176 			cmn_err(CE_NOTE, "kernel debugger active; anonymous "
12177 			    "enabling ignored.");
12178 			dtrace_dof_destroy(dof);
12179 			break;
12180 		}
12181 
12182 		/*
12183 		 * If we haven't allocated an anonymous state, we'll do so now.
12184 		 */
12185 		if ((state = dtrace_anon.dta_state) == NULL) {
12186 			state = dtrace_state_create(NULL, NULL);
12187 			dtrace_anon.dta_state = state;
12188 
12189 			if (state == NULL) {
12190 				/*
12191 				 * This basically shouldn't happen:  the only
12192 				 * failure mode from dtrace_state_create() is a
12193 				 * failure of ddi_soft_state_zalloc() that
12194 				 * itself should never happen.  Still, the
12195 				 * interface allows for a failure mode, and
12196 				 * we want to fail as gracefully as possible:
12197 				 * we'll emit an error message and cease
12198 				 * processing anonymous state in this case.
12199 				 */
12200 				cmn_err(CE_WARN, "failed to create "
12201 				    "anonymous state");
12202 				dtrace_dof_destroy(dof);
12203 				break;
12204 			}
12205 		}
12206 
12207 		rv = dtrace_dof_slurp(dof, &state->dts_vstate, CRED(),
12208 		    &dtrace_anon.dta_enabling, 0, B_TRUE);
12209 
12210 		if (rv == 0)
12211 			rv = dtrace_dof_options(dof, state);
12212 
12213 		dtrace_err_verbose = 0;
12214 		dtrace_dof_destroy(dof);
12215 
12216 		if (rv != 0) {
12217 			/*
12218 			 * This is malformed DOF; chuck any anonymous state
12219 			 * that we created.
12220 			 */
12221 			ASSERT(dtrace_anon.dta_enabling == NULL);
12222 			dtrace_state_destroy(state);
12223 			dtrace_anon.dta_state = NULL;
12224 			break;
12225 		}
12226 
12227 		ASSERT(dtrace_anon.dta_enabling != NULL);
12228 	}
12229 
12230 	if (dtrace_anon.dta_enabling != NULL) {
12231 		int rval;
12232 
12233 		/*
12234 		 * dtrace_enabling_retain() can only fail because we are
12235 		 * trying to retain more enablings than are allowed -- but
12236 		 * we only have one anonymous enabling, and we are guaranteed
12237 		 * to be allowed at least one retained enabling; we assert
12238 		 * that dtrace_enabling_retain() returns success.
12239 		 */
12240 		rval = dtrace_enabling_retain(dtrace_anon.dta_enabling);
12241 		ASSERT(rval == 0);
12242 
12243 		dtrace_enabling_dump(dtrace_anon.dta_enabling);
12244 	}
12245 }
12246 
12247 /*
12248  * DTrace Helper Functions
12249  */
12250 static void
12251 dtrace_helper_trace(dtrace_helper_action_t *helper,
12252     dtrace_mstate_t *mstate, dtrace_vstate_t *vstate, int where)
12253 {
12254 	uint32_t size, next, nnext, i;
12255 	dtrace_helptrace_t *ent;
12256 	uint16_t flags = cpu_core[CPU->cpu_id].cpuc_dtrace_flags;
12257 
12258 	if (!dtrace_helptrace_enabled)
12259 		return;
12260 
12261 	ASSERT(vstate->dtvs_nlocals <= dtrace_helptrace_nlocals);
12262 
12263 	/*
12264 	 * What would a tracing framework be without its own tracing
12265 	 * framework?  (Well, a hell of a lot simpler, for starters...)
12266 	 */
12267 	size = sizeof (dtrace_helptrace_t) + dtrace_helptrace_nlocals *
12268 	    sizeof (uint64_t) - sizeof (uint64_t);
12269 
12270 	/*
12271 	 * Iterate until we can allocate a slot in the trace buffer.
12272 	 */
12273 	do {
12274 		next = dtrace_helptrace_next;
12275 
12276 		if (next + size < dtrace_helptrace_bufsize) {
12277 			nnext = next + size;
12278 		} else {
12279 			nnext = size;
12280 		}
12281 	} while (dtrace_cas32(&dtrace_helptrace_next, next, nnext) != next);
12282 
12283 	/*
12284 	 * We have our slot; fill it in.
12285 	 */
12286 	if (nnext == size)
12287 		next = 0;
12288 
12289 	ent = (dtrace_helptrace_t *)&dtrace_helptrace_buffer[next];
12290 	ent->dtht_helper = helper;
12291 	ent->dtht_where = where;
12292 	ent->dtht_nlocals = vstate->dtvs_nlocals;
12293 
12294 	ent->dtht_fltoffs = (mstate->dtms_present & DTRACE_MSTATE_FLTOFFS) ?
12295 	    mstate->dtms_fltoffs : -1;
12296 	ent->dtht_fault = DTRACE_FLAGS2FLT(flags);
12297 	ent->dtht_illval = cpu_core[CPU->cpu_id].cpuc_dtrace_illval;
12298 
12299 	for (i = 0; i < vstate->dtvs_nlocals; i++) {
12300 		dtrace_statvar_t *svar;
12301 
12302 		if ((svar = vstate->dtvs_locals[i]) == NULL)
12303 			continue;
12304 
12305 		ASSERT(svar->dtsv_size >= NCPU * sizeof (uint64_t));
12306 		ent->dtht_locals[i] =
12307 		    ((uint64_t *)(uintptr_t)svar->dtsv_data)[CPU->cpu_id];
12308 	}
12309 }
12310 
12311 static uint64_t
12312 dtrace_helper(int which, dtrace_mstate_t *mstate,
12313     dtrace_state_t *state, uint64_t arg0, uint64_t arg1)
12314 {
12315 	uint16_t *flags = &cpu_core[CPU->cpu_id].cpuc_dtrace_flags;
12316 	uint64_t sarg0 = mstate->dtms_arg[0];
12317 	uint64_t sarg1 = mstate->dtms_arg[1];
12318 	uint64_t rval;
12319 	dtrace_helpers_t *helpers = curproc->p_dtrace_helpers;
12320 	dtrace_helper_action_t *helper;
12321 	dtrace_vstate_t *vstate;
12322 	dtrace_difo_t *pred;
12323 	int i, trace = dtrace_helptrace_enabled;
12324 
12325 	ASSERT(which >= 0 && which < DTRACE_NHELPER_ACTIONS);
12326 
12327 	if (helpers == NULL)
12328 		return (0);
12329 
12330 	if ((helper = helpers->dthps_actions[which]) == NULL)
12331 		return (0);
12332 
12333 	vstate = &helpers->dthps_vstate;
12334 	mstate->dtms_arg[0] = arg0;
12335 	mstate->dtms_arg[1] = arg1;
12336 
12337 	/*
12338 	 * Now iterate over each helper.  If its predicate evaluates to 'true',
12339 	 * we'll call the corresponding actions.  Note that the below calls
12340 	 * to dtrace_dif_emulate() may set faults in machine state.  This is
12341 	 * okay:  our caller (the outer dtrace_dif_emulate()) will simply plow
12342 	 * the stored DIF offset with its own (which is the desired behavior).
12343 	 * Also, note the calls to dtrace_dif_emulate() may allocate scratch
12344 	 * from machine state; this is okay, too.
12345 	 */
12346 	for (; helper != NULL; helper = helper->dtha_next) {
12347 		if ((pred = helper->dtha_predicate) != NULL) {
12348 			if (trace)
12349 				dtrace_helper_trace(helper, mstate, vstate, 0);
12350 
12351 			if (!dtrace_dif_emulate(pred, mstate, vstate, state))
12352 				goto next;
12353 
12354 			if (*flags & CPU_DTRACE_FAULT)
12355 				goto err;
12356 		}
12357 
12358 		for (i = 0; i < helper->dtha_nactions; i++) {
12359 			if (trace)
12360 				dtrace_helper_trace(helper,
12361 				    mstate, vstate, i + 1);
12362 
12363 			rval = dtrace_dif_emulate(helper->dtha_actions[i],
12364 			    mstate, vstate, state);
12365 
12366 			if (*flags & CPU_DTRACE_FAULT)
12367 				goto err;
12368 		}
12369 
12370 next:
12371 		if (trace)
12372 			dtrace_helper_trace(helper, mstate, vstate,
12373 			    DTRACE_HELPTRACE_NEXT);
12374 	}
12375 
12376 	if (trace)
12377 		dtrace_helper_trace(helper, mstate, vstate,
12378 		    DTRACE_HELPTRACE_DONE);
12379 
12380 	/*
12381 	 * Restore the arg0 that we saved upon entry.
12382 	 */
12383 	mstate->dtms_arg[0] = sarg0;
12384 	mstate->dtms_arg[1] = sarg1;
12385 
12386 	return (rval);
12387 
12388 err:
12389 	if (trace)
12390 		dtrace_helper_trace(helper, mstate, vstate,
12391 		    DTRACE_HELPTRACE_ERR);
12392 
12393 	/*
12394 	 * Restore the arg0 that we saved upon entry.
12395 	 */
12396 	mstate->dtms_arg[0] = sarg0;
12397 	mstate->dtms_arg[1] = sarg1;
12398 
12399 	return (NULL);
12400 }
12401 
12402 static void
12403 dtrace_helper_action_destroy(dtrace_helper_action_t *helper,
12404     dtrace_vstate_t *vstate)
12405 {
12406 	int i;
12407 
12408 	if (helper->dtha_predicate != NULL)
12409 		dtrace_difo_release(helper->dtha_predicate, vstate);
12410 
12411 	for (i = 0; i < helper->dtha_nactions; i++) {
12412 		ASSERT(helper->dtha_actions[i] != NULL);
12413 		dtrace_difo_release(helper->dtha_actions[i], vstate);
12414 	}
12415 
12416 	kmem_free(helper->dtha_actions,
12417 	    helper->dtha_nactions * sizeof (dtrace_difo_t *));
12418 	kmem_free(helper, sizeof (dtrace_helper_action_t));
12419 }
12420 
12421 static int
12422 dtrace_helper_destroygen(int gen)
12423 {
12424 	proc_t *p = curproc;
12425 	dtrace_helpers_t *help = p->p_dtrace_helpers;
12426 	dtrace_vstate_t *vstate;
12427 	int i;
12428 
12429 	ASSERT(MUTEX_HELD(&dtrace_lock));
12430 
12431 	if (help == NULL || gen > help->dthps_generation)
12432 		return (EINVAL);
12433 
12434 	vstate = &help->dthps_vstate;
12435 
12436 	for (i = 0; i < DTRACE_NHELPER_ACTIONS; i++) {
12437 		dtrace_helper_action_t *last = NULL, *h, *next;
12438 
12439 		for (h = help->dthps_actions[i]; h != NULL; h = next) {
12440 			next = h->dtha_next;
12441 
12442 			if (h->dtha_generation == gen) {
12443 				if (last != NULL) {
12444 					last->dtha_next = next;
12445 				} else {
12446 					help->dthps_actions[i] = next;
12447 				}
12448 
12449 				dtrace_helper_action_destroy(h, vstate);
12450 			} else {
12451 				last = h;
12452 			}
12453 		}
12454 	}
12455 
12456 	/*
12457 	 * Interate until we've cleared out all helper providers with the
12458 	 * given generation number.
12459 	 */
12460 	for (;;) {
12461 		dtrace_helper_provider_t *prov;
12462 
12463 		/*
12464 		 * Look for a helper provider with the right generation. We
12465 		 * have to start back at the beginning of the list each time
12466 		 * because we drop dtrace_lock. It's unlikely that we'll make
12467 		 * more than two passes.
12468 		 */
12469 		for (i = 0; i < help->dthps_nprovs; i++) {
12470 			prov = help->dthps_provs[i];
12471 
12472 			if (prov->dthp_generation == gen)
12473 				break;
12474 		}
12475 
12476 		/*
12477 		 * If there were no matches, we're done.
12478 		 */
12479 		if (i == help->dthps_nprovs)
12480 			break;
12481 
12482 		/*
12483 		 * Move the last helper provider into this slot.
12484 		 */
12485 		help->dthps_nprovs--;
12486 		help->dthps_provs[i] = help->dthps_provs[help->dthps_nprovs];
12487 		help->dthps_provs[help->dthps_nprovs] = NULL;
12488 
12489 		mutex_exit(&dtrace_lock);
12490 
12491 		/*
12492 		 * If we have a meta provider, remove this helper provider.
12493 		 */
12494 		mutex_enter(&dtrace_meta_lock);
12495 		if (dtrace_meta_pid != NULL) {
12496 			ASSERT(dtrace_deferred_pid == NULL);
12497 			dtrace_helper_provider_remove(&prov->dthp_prov,
12498 			    p->p_pid);
12499 		}
12500 		mutex_exit(&dtrace_meta_lock);
12501 
12502 		dtrace_helper_provider_destroy(prov);
12503 
12504 		mutex_enter(&dtrace_lock);
12505 	}
12506 
12507 	return (0);
12508 }
12509 
12510 static int
12511 dtrace_helper_validate(dtrace_helper_action_t *helper)
12512 {
12513 	int err = 0, i;
12514 	dtrace_difo_t *dp;
12515 
12516 	if ((dp = helper->dtha_predicate) != NULL)
12517 		err += dtrace_difo_validate_helper(dp);
12518 
12519 	for (i = 0; i < helper->dtha_nactions; i++)
12520 		err += dtrace_difo_validate_helper(helper->dtha_actions[i]);
12521 
12522 	return (err == 0);
12523 }
12524 
12525 static int
12526 dtrace_helper_action_add(int which, dtrace_ecbdesc_t *ep)
12527 {
12528 	dtrace_helpers_t *help;
12529 	dtrace_helper_action_t *helper, *last;
12530 	dtrace_actdesc_t *act;
12531 	dtrace_vstate_t *vstate;
12532 	dtrace_predicate_t *pred;
12533 	int count = 0, nactions = 0, i;
12534 
12535 	if (which < 0 || which >= DTRACE_NHELPER_ACTIONS)
12536 		return (EINVAL);
12537 
12538 	help = curproc->p_dtrace_helpers;
12539 	last = help->dthps_actions[which];
12540 	vstate = &help->dthps_vstate;
12541 
12542 	for (count = 0; last != NULL; last = last->dtha_next) {
12543 		count++;
12544 		if (last->dtha_next == NULL)
12545 			break;
12546 	}
12547 
12548 	/*
12549 	 * If we already have dtrace_helper_actions_max helper actions for this
12550 	 * helper action type, we'll refuse to add a new one.
12551 	 */
12552 	if (count >= dtrace_helper_actions_max)
12553 		return (ENOSPC);
12554 
12555 	helper = kmem_zalloc(sizeof (dtrace_helper_action_t), KM_SLEEP);
12556 	helper->dtha_generation = help->dthps_generation;
12557 
12558 	if ((pred = ep->dted_pred.dtpdd_predicate) != NULL) {
12559 		ASSERT(pred->dtp_difo != NULL);
12560 		dtrace_difo_hold(pred->dtp_difo);
12561 		helper->dtha_predicate = pred->dtp_difo;
12562 	}
12563 
12564 	for (act = ep->dted_action; act != NULL; act = act->dtad_next) {
12565 		if (act->dtad_kind != DTRACEACT_DIFEXPR)
12566 			goto err;
12567 
12568 		if (act->dtad_difo == NULL)
12569 			goto err;
12570 
12571 		nactions++;
12572 	}
12573 
12574 	helper->dtha_actions = kmem_zalloc(sizeof (dtrace_difo_t *) *
12575 	    (helper->dtha_nactions = nactions), KM_SLEEP);
12576 
12577 	for (act = ep->dted_action, i = 0; act != NULL; act = act->dtad_next) {
12578 		dtrace_difo_hold(act->dtad_difo);
12579 		helper->dtha_actions[i++] = act->dtad_difo;
12580 	}
12581 
12582 	if (!dtrace_helper_validate(helper))
12583 		goto err;
12584 
12585 	if (last == NULL) {
12586 		help->dthps_actions[which] = helper;
12587 	} else {
12588 		last->dtha_next = helper;
12589 	}
12590 
12591 	if (vstate->dtvs_nlocals > dtrace_helptrace_nlocals) {
12592 		dtrace_helptrace_nlocals = vstate->dtvs_nlocals;
12593 		dtrace_helptrace_next = 0;
12594 	}
12595 
12596 	return (0);
12597 err:
12598 	dtrace_helper_action_destroy(helper, vstate);
12599 	return (EINVAL);
12600 }
12601 
12602 static void
12603 dtrace_helper_provider_register(proc_t *p, dtrace_helpers_t *help,
12604     dof_helper_t *dofhp)
12605 {
12606 	ASSERT(MUTEX_NOT_HELD(&dtrace_lock));
12607 
12608 	mutex_enter(&dtrace_meta_lock);
12609 	mutex_enter(&dtrace_lock);
12610 
12611 	if (!dtrace_attached() || dtrace_meta_pid == NULL) {
12612 		/*
12613 		 * If the dtrace module is loaded but not attached, or if
12614 		 * there aren't isn't a meta provider registered to deal with
12615 		 * these provider descriptions, we need to postpone creating
12616 		 * the actual providers until later.
12617 		 */
12618 
12619 		if (help->dthps_next == NULL && help->dthps_prev == NULL &&
12620 		    dtrace_deferred_pid != help) {
12621 			help->dthps_deferred = 1;
12622 			help->dthps_pid = p->p_pid;
12623 			help->dthps_next = dtrace_deferred_pid;
12624 			help->dthps_prev = NULL;
12625 			if (dtrace_deferred_pid != NULL)
12626 				dtrace_deferred_pid->dthps_prev = help;
12627 			dtrace_deferred_pid = help;
12628 		}
12629 
12630 		mutex_exit(&dtrace_lock);
12631 
12632 	} else if (dofhp != NULL) {
12633 		/*
12634 		 * If the dtrace module is loaded and we have a particular
12635 		 * helper provider description, pass that off to the
12636 		 * meta provider.
12637 		 */
12638 
12639 		mutex_exit(&dtrace_lock);
12640 
12641 		dtrace_helper_provide(dofhp, p->p_pid);
12642 
12643 	} else {
12644 		/*
12645 		 * Otherwise, just pass all the helper provider descriptions
12646 		 * off to the meta provider.
12647 		 */
12648 
12649 		int i;
12650 		mutex_exit(&dtrace_lock);
12651 
12652 		for (i = 0; i < help->dthps_nprovs; i++) {
12653 			dtrace_helper_provide(&help->dthps_provs[i]->dthp_prov,
12654 			    p->p_pid);
12655 		}
12656 	}
12657 
12658 	mutex_exit(&dtrace_meta_lock);
12659 }
12660 
12661 static int
12662 dtrace_helper_provider_add(dof_helper_t *dofhp, int gen)
12663 {
12664 	dtrace_helpers_t *help;
12665 	dtrace_helper_provider_t *hprov, **tmp_provs;
12666 	uint_t tmp_maxprovs, i;
12667 
12668 	ASSERT(MUTEX_HELD(&dtrace_lock));
12669 
12670 	help = curproc->p_dtrace_helpers;
12671 	ASSERT(help != NULL);
12672 
12673 	/*
12674 	 * If we already have dtrace_helper_providers_max helper providers,
12675 	 * we're refuse to add a new one.
12676 	 */
12677 	if (help->dthps_nprovs >= dtrace_helper_providers_max)
12678 		return (ENOSPC);
12679 
12680 	/*
12681 	 * Check to make sure this isn't a duplicate.
12682 	 */
12683 	for (i = 0; i < help->dthps_nprovs; i++) {
12684 		if (dofhp->dofhp_addr ==
12685 		    help->dthps_provs[i]->dthp_prov.dofhp_addr)
12686 			return (EALREADY);
12687 	}
12688 
12689 	hprov = kmem_zalloc(sizeof (dtrace_helper_provider_t), KM_SLEEP);
12690 	hprov->dthp_prov = *dofhp;
12691 	hprov->dthp_ref = 1;
12692 	hprov->dthp_generation = gen;
12693 
12694 	/*
12695 	 * Allocate a bigger table for helper providers if it's already full.
12696 	 */
12697 	if (help->dthps_maxprovs == help->dthps_nprovs) {
12698 		tmp_maxprovs = help->dthps_maxprovs;
12699 		tmp_provs = help->dthps_provs;
12700 
12701 		if (help->dthps_maxprovs == 0)
12702 			help->dthps_maxprovs = 2;
12703 		else
12704 			help->dthps_maxprovs *= 2;
12705 		if (help->dthps_maxprovs > dtrace_helper_providers_max)
12706 			help->dthps_maxprovs = dtrace_helper_providers_max;
12707 
12708 		ASSERT(tmp_maxprovs < help->dthps_maxprovs);
12709 
12710 		help->dthps_provs = kmem_zalloc(help->dthps_maxprovs *
12711 		    sizeof (dtrace_helper_provider_t *), KM_SLEEP);
12712 
12713 		if (tmp_provs != NULL) {
12714 			bcopy(tmp_provs, help->dthps_provs, tmp_maxprovs *
12715 			    sizeof (dtrace_helper_provider_t *));
12716 			kmem_free(tmp_provs, tmp_maxprovs *
12717 			    sizeof (dtrace_helper_provider_t *));
12718 		}
12719 	}
12720 
12721 	help->dthps_provs[help->dthps_nprovs] = hprov;
12722 	help->dthps_nprovs++;
12723 
12724 	return (0);
12725 }
12726 
12727 static void
12728 dtrace_helper_provider_destroy(dtrace_helper_provider_t *hprov)
12729 {
12730 	mutex_enter(&dtrace_lock);
12731 
12732 	if (--hprov->dthp_ref == 0) {
12733 		dof_hdr_t *dof;
12734 		mutex_exit(&dtrace_lock);
12735 		dof = (dof_hdr_t *)(uintptr_t)hprov->dthp_prov.dofhp_dof;
12736 		dtrace_dof_destroy(dof);
12737 		kmem_free(hprov, sizeof (dtrace_helper_provider_t));
12738 	} else {
12739 		mutex_exit(&dtrace_lock);
12740 	}
12741 }
12742 
12743 static int
12744 dtrace_helper_provider_validate(dof_hdr_t *dof, dof_sec_t *sec)
12745 {
12746 	uintptr_t daddr = (uintptr_t)dof;
12747 	dof_sec_t *str_sec, *prb_sec, *arg_sec, *off_sec, *enoff_sec;
12748 	dof_provider_t *provider;
12749 	dof_probe_t *probe;
12750 	uint8_t *arg;
12751 	char *strtab, *typestr;
12752 	dof_stridx_t typeidx;
12753 	size_t typesz;
12754 	uint_t nprobes, j, k;
12755 
12756 	ASSERT(sec->dofs_type == DOF_SECT_PROVIDER);
12757 
12758 	if (sec->dofs_offset & (sizeof (uint_t) - 1)) {
12759 		dtrace_dof_error(dof, "misaligned section offset");
12760 		return (-1);
12761 	}
12762 
12763 	/*
12764 	 * The section needs to be large enough to contain the DOF provider
12765 	 * structure appropriate for the given version.
12766 	 */
12767 	if (sec->dofs_size <
12768 	    ((dof->dofh_ident[DOF_ID_VERSION] == DOF_VERSION_1) ?
12769 	    offsetof(dof_provider_t, dofpv_prenoffs) :
12770 	    sizeof (dof_provider_t))) {
12771 		dtrace_dof_error(dof, "provider section too small");
12772 		return (-1);
12773 	}
12774 
12775 	provider = (dof_provider_t *)(uintptr_t)(daddr + sec->dofs_offset);
12776 	str_sec = dtrace_dof_sect(dof, DOF_SECT_STRTAB, provider->dofpv_strtab);
12777 	prb_sec = dtrace_dof_sect(dof, DOF_SECT_PROBES, provider->dofpv_probes);
12778 	arg_sec = dtrace_dof_sect(dof, DOF_SECT_PRARGS, provider->dofpv_prargs);
12779 	off_sec = dtrace_dof_sect(dof, DOF_SECT_PROFFS, provider->dofpv_proffs);
12780 
12781 	if (str_sec == NULL || prb_sec == NULL ||
12782 	    arg_sec == NULL || off_sec == NULL)
12783 		return (-1);
12784 
12785 	enoff_sec = NULL;
12786 
12787 	if (dof->dofh_ident[DOF_ID_VERSION] != DOF_VERSION_1 &&
12788 	    provider->dofpv_prenoffs != DOF_SECT_NONE &&
12789 	    (enoff_sec = dtrace_dof_sect(dof, DOF_SECT_PRENOFFS,
12790 	    provider->dofpv_prenoffs)) == NULL)
12791 		return (-1);
12792 
12793 	strtab = (char *)(uintptr_t)(daddr + str_sec->dofs_offset);
12794 
12795 	if (provider->dofpv_name >= str_sec->dofs_size ||
12796 	    strlen(strtab + provider->dofpv_name) >= DTRACE_PROVNAMELEN) {
12797 		dtrace_dof_error(dof, "invalid provider name");
12798 		return (-1);
12799 	}
12800 
12801 	if (prb_sec->dofs_entsize == 0 ||
12802 	    prb_sec->dofs_entsize > prb_sec->dofs_size) {
12803 		dtrace_dof_error(dof, "invalid entry size");
12804 		return (-1);
12805 	}
12806 
12807 	if (prb_sec->dofs_entsize & (sizeof (uintptr_t) - 1)) {
12808 		dtrace_dof_error(dof, "misaligned entry size");
12809 		return (-1);
12810 	}
12811 
12812 	if (off_sec->dofs_entsize != sizeof (uint32_t)) {
12813 		dtrace_dof_error(dof, "invalid entry size");
12814 		return (-1);
12815 	}
12816 
12817 	if (off_sec->dofs_offset & (sizeof (uint32_t) - 1)) {
12818 		dtrace_dof_error(dof, "misaligned section offset");
12819 		return (-1);
12820 	}
12821 
12822 	if (arg_sec->dofs_entsize != sizeof (uint8_t)) {
12823 		dtrace_dof_error(dof, "invalid entry size");
12824 		return (-1);
12825 	}
12826 
12827 	arg = (uint8_t *)(uintptr_t)(daddr + arg_sec->dofs_offset);
12828 
12829 	nprobes = prb_sec->dofs_size / prb_sec->dofs_entsize;
12830 
12831 	/*
12832 	 * Take a pass through the probes to check for errors.
12833 	 */
12834 	for (j = 0; j < nprobes; j++) {
12835 		probe = (dof_probe_t *)(uintptr_t)(daddr +
12836 		    prb_sec->dofs_offset + j * prb_sec->dofs_entsize);
12837 
12838 		if (probe->dofpr_func >= str_sec->dofs_size) {
12839 			dtrace_dof_error(dof, "invalid function name");
12840 			return (-1);
12841 		}
12842 
12843 		if (strlen(strtab + probe->dofpr_func) >= DTRACE_FUNCNAMELEN) {
12844 			dtrace_dof_error(dof, "function name too long");
12845 			return (-1);
12846 		}
12847 
12848 		if (probe->dofpr_name >= str_sec->dofs_size ||
12849 		    strlen(strtab + probe->dofpr_name) >= DTRACE_NAMELEN) {
12850 			dtrace_dof_error(dof, "invalid probe name");
12851 			return (-1);
12852 		}
12853 
12854 		/*
12855 		 * The offset count must not wrap the index, and the offsets
12856 		 * must also not overflow the section's data.
12857 		 */
12858 		if (probe->dofpr_offidx + probe->dofpr_noffs <
12859 		    probe->dofpr_offidx ||
12860 		    (probe->dofpr_offidx + probe->dofpr_noffs) *
12861 		    off_sec->dofs_entsize > off_sec->dofs_size) {
12862 			dtrace_dof_error(dof, "invalid probe offset");
12863 			return (-1);
12864 		}
12865 
12866 		if (dof->dofh_ident[DOF_ID_VERSION] != DOF_VERSION_1) {
12867 			/*
12868 			 * If there's no is-enabled offset section, make sure
12869 			 * there aren't any is-enabled offsets. Otherwise
12870 			 * perform the same checks as for probe offsets
12871 			 * (immediately above).
12872 			 */
12873 			if (enoff_sec == NULL) {
12874 				if (probe->dofpr_enoffidx != 0 ||
12875 				    probe->dofpr_nenoffs != 0) {
12876 					dtrace_dof_error(dof, "is-enabled "
12877 					    "offsets with null section");
12878 					return (-1);
12879 				}
12880 			} else if (probe->dofpr_enoffidx +
12881 			    probe->dofpr_nenoffs < probe->dofpr_enoffidx ||
12882 			    (probe->dofpr_enoffidx + probe->dofpr_nenoffs) *
12883 			    enoff_sec->dofs_entsize > enoff_sec->dofs_size) {
12884 				dtrace_dof_error(dof, "invalid is-enabled "
12885 				    "offset");
12886 				return (-1);
12887 			}
12888 
12889 			if (probe->dofpr_noffs + probe->dofpr_nenoffs == 0) {
12890 				dtrace_dof_error(dof, "zero probe and "
12891 				    "is-enabled offsets");
12892 				return (-1);
12893 			}
12894 		} else if (probe->dofpr_noffs == 0) {
12895 			dtrace_dof_error(dof, "zero probe offsets");
12896 			return (-1);
12897 		}
12898 
12899 		if (probe->dofpr_argidx + probe->dofpr_xargc <
12900 		    probe->dofpr_argidx ||
12901 		    (probe->dofpr_argidx + probe->dofpr_xargc) *
12902 		    arg_sec->dofs_entsize > arg_sec->dofs_size) {
12903 			dtrace_dof_error(dof, "invalid args");
12904 			return (-1);
12905 		}
12906 
12907 		typeidx = probe->dofpr_nargv;
12908 		typestr = strtab + probe->dofpr_nargv;
12909 		for (k = 0; k < probe->dofpr_nargc; k++) {
12910 			if (typeidx >= str_sec->dofs_size) {
12911 				dtrace_dof_error(dof, "bad "
12912 				    "native argument type");
12913 				return (-1);
12914 			}
12915 
12916 			typesz = strlen(typestr) + 1;
12917 			if (typesz > DTRACE_ARGTYPELEN) {
12918 				dtrace_dof_error(dof, "native "
12919 				    "argument type too long");
12920 				return (-1);
12921 			}
12922 			typeidx += typesz;
12923 			typestr += typesz;
12924 		}
12925 
12926 		typeidx = probe->dofpr_xargv;
12927 		typestr = strtab + probe->dofpr_xargv;
12928 		for (k = 0; k < probe->dofpr_xargc; k++) {
12929 			if (arg[probe->dofpr_argidx + k] > probe->dofpr_nargc) {
12930 				dtrace_dof_error(dof, "bad "
12931 				    "native argument index");
12932 				return (-1);
12933 			}
12934 
12935 			if (typeidx >= str_sec->dofs_size) {
12936 				dtrace_dof_error(dof, "bad "
12937 				    "translated argument type");
12938 				return (-1);
12939 			}
12940 
12941 			typesz = strlen(typestr) + 1;
12942 			if (typesz > DTRACE_ARGTYPELEN) {
12943 				dtrace_dof_error(dof, "translated argument "
12944 				    "type too long");
12945 				return (-1);
12946 			}
12947 
12948 			typeidx += typesz;
12949 			typestr += typesz;
12950 		}
12951 	}
12952 
12953 	return (0);
12954 }
12955 
12956 static int
12957 dtrace_helper_slurp(dof_hdr_t *dof, dof_helper_t *dhp)
12958 {
12959 	dtrace_helpers_t *help;
12960 	dtrace_vstate_t *vstate;
12961 	dtrace_enabling_t *enab = NULL;
12962 	int i, gen, rv, nhelpers = 0, nprovs = 0, destroy = 1;
12963 	uintptr_t daddr = (uintptr_t)dof;
12964 
12965 	ASSERT(MUTEX_HELD(&dtrace_lock));
12966 
12967 	if ((help = curproc->p_dtrace_helpers) == NULL)
12968 		help = dtrace_helpers_create(curproc);
12969 
12970 	vstate = &help->dthps_vstate;
12971 
12972 	if ((rv = dtrace_dof_slurp(dof, vstate, NULL, &enab,
12973 	    dhp != NULL ? dhp->dofhp_addr : 0, B_FALSE)) != 0) {
12974 		dtrace_dof_destroy(dof);
12975 		return (rv);
12976 	}
12977 
12978 	/*
12979 	 * Look for helper providers and validate their descriptions.
12980 	 */
12981 	if (dhp != NULL) {
12982 		for (i = 0; i < dof->dofh_secnum; i++) {
12983 			dof_sec_t *sec = (dof_sec_t *)(uintptr_t)(daddr +
12984 			    dof->dofh_secoff + i * dof->dofh_secsize);
12985 
12986 			if (sec->dofs_type != DOF_SECT_PROVIDER)
12987 				continue;
12988 
12989 			if (dtrace_helper_provider_validate(dof, sec) != 0) {
12990 				dtrace_enabling_destroy(enab);
12991 				dtrace_dof_destroy(dof);
12992 				return (-1);
12993 			}
12994 
12995 			nprovs++;
12996 		}
12997 	}
12998 
12999 	/*
13000 	 * Now we need to walk through the ECB descriptions in the enabling.
13001 	 */
13002 	for (i = 0; i < enab->dten_ndesc; i++) {
13003 		dtrace_ecbdesc_t *ep = enab->dten_desc[i];
13004 		dtrace_probedesc_t *desc = &ep->dted_probe;
13005 
13006 		if (strcmp(desc->dtpd_provider, "dtrace") != 0)
13007 			continue;
13008 
13009 		if (strcmp(desc->dtpd_mod, "helper") != 0)
13010 			continue;
13011 
13012 		if (strcmp(desc->dtpd_func, "ustack") != 0)
13013 			continue;
13014 
13015 		if ((rv = dtrace_helper_action_add(DTRACE_HELPER_ACTION_USTACK,
13016 		    ep)) != 0) {
13017 			/*
13018 			 * Adding this helper action failed -- we are now going
13019 			 * to rip out the entire generation and return failure.
13020 			 */
13021 			(void) dtrace_helper_destroygen(help->dthps_generation);
13022 			dtrace_enabling_destroy(enab);
13023 			dtrace_dof_destroy(dof);
13024 			return (-1);
13025 		}
13026 
13027 		nhelpers++;
13028 	}
13029 
13030 	if (nhelpers < enab->dten_ndesc)
13031 		dtrace_dof_error(dof, "unmatched helpers");
13032 
13033 	gen = help->dthps_generation++;
13034 	dtrace_enabling_destroy(enab);
13035 
13036 	if (dhp != NULL && nprovs > 0) {
13037 		dhp->dofhp_dof = (uint64_t)(uintptr_t)dof;
13038 		if (dtrace_helper_provider_add(dhp, gen) == 0) {
13039 			mutex_exit(&dtrace_lock);
13040 			dtrace_helper_provider_register(curproc, help, dhp);
13041 			mutex_enter(&dtrace_lock);
13042 
13043 			destroy = 0;
13044 		}
13045 	}
13046 
13047 	if (destroy)
13048 		dtrace_dof_destroy(dof);
13049 
13050 	return (gen);
13051 }
13052 
13053 static dtrace_helpers_t *
13054 dtrace_helpers_create(proc_t *p)
13055 {
13056 	dtrace_helpers_t *help;
13057 
13058 	ASSERT(MUTEX_HELD(&dtrace_lock));
13059 	ASSERT(p->p_dtrace_helpers == NULL);
13060 
13061 	help = kmem_zalloc(sizeof (dtrace_helpers_t), KM_SLEEP);
13062 	help->dthps_actions = kmem_zalloc(sizeof (dtrace_helper_action_t *) *
13063 	    DTRACE_NHELPER_ACTIONS, KM_SLEEP);
13064 
13065 	p->p_dtrace_helpers = help;
13066 	dtrace_helpers++;
13067 
13068 	return (help);
13069 }
13070 
13071 static void
13072 dtrace_helpers_destroy(void)
13073 {
13074 	dtrace_helpers_t *help;
13075 	dtrace_vstate_t *vstate;
13076 	proc_t *p = curproc;
13077 	int i;
13078 
13079 	mutex_enter(&dtrace_lock);
13080 
13081 	ASSERT(p->p_dtrace_helpers != NULL);
13082 	ASSERT(dtrace_helpers > 0);
13083 
13084 	help = p->p_dtrace_helpers;
13085 	vstate = &help->dthps_vstate;
13086 
13087 	/*
13088 	 * We're now going to lose the help from this process.
13089 	 */
13090 	p->p_dtrace_helpers = NULL;
13091 	dtrace_sync();
13092 
13093 	/*
13094 	 * Destory the helper actions.
13095 	 */
13096 	for (i = 0; i < DTRACE_NHELPER_ACTIONS; i++) {
13097 		dtrace_helper_action_t *h, *next;
13098 
13099 		for (h = help->dthps_actions[i]; h != NULL; h = next) {
13100 			next = h->dtha_next;
13101 			dtrace_helper_action_destroy(h, vstate);
13102 			h = next;
13103 		}
13104 	}
13105 
13106 	mutex_exit(&dtrace_lock);
13107 
13108 	/*
13109 	 * Destroy the helper providers.
13110 	 */
13111 	if (help->dthps_maxprovs > 0) {
13112 		mutex_enter(&dtrace_meta_lock);
13113 		if (dtrace_meta_pid != NULL) {
13114 			ASSERT(dtrace_deferred_pid == NULL);
13115 
13116 			for (i = 0; i < help->dthps_nprovs; i++) {
13117 				dtrace_helper_provider_remove(
13118 				    &help->dthps_provs[i]->dthp_prov, p->p_pid);
13119 			}
13120 		} else {
13121 			mutex_enter(&dtrace_lock);
13122 			ASSERT(help->dthps_deferred == 0 ||
13123 			    help->dthps_next != NULL ||
13124 			    help->dthps_prev != NULL ||
13125 			    help == dtrace_deferred_pid);
13126 
13127 			/*
13128 			 * Remove the helper from the deferred list.
13129 			 */
13130 			if (help->dthps_next != NULL)
13131 				help->dthps_next->dthps_prev = help->dthps_prev;
13132 			if (help->dthps_prev != NULL)
13133 				help->dthps_prev->dthps_next = help->dthps_next;
13134 			if (dtrace_deferred_pid == help) {
13135 				dtrace_deferred_pid = help->dthps_next;
13136 				ASSERT(help->dthps_prev == NULL);
13137 			}
13138 
13139 			mutex_exit(&dtrace_lock);
13140 		}
13141 
13142 		mutex_exit(&dtrace_meta_lock);
13143 
13144 		for (i = 0; i < help->dthps_nprovs; i++) {
13145 			dtrace_helper_provider_destroy(help->dthps_provs[i]);
13146 		}
13147 
13148 		kmem_free(help->dthps_provs, help->dthps_maxprovs *
13149 		    sizeof (dtrace_helper_provider_t *));
13150 	}
13151 
13152 	mutex_enter(&dtrace_lock);
13153 
13154 	dtrace_vstate_fini(&help->dthps_vstate);
13155 	kmem_free(help->dthps_actions,
13156 	    sizeof (dtrace_helper_action_t *) * DTRACE_NHELPER_ACTIONS);
13157 	kmem_free(help, sizeof (dtrace_helpers_t));
13158 
13159 	--dtrace_helpers;
13160 	mutex_exit(&dtrace_lock);
13161 }
13162 
13163 static void
13164 dtrace_helpers_duplicate(proc_t *from, proc_t *to)
13165 {
13166 	dtrace_helpers_t *help, *newhelp;
13167 	dtrace_helper_action_t *helper, *new, *last;
13168 	dtrace_difo_t *dp;
13169 	dtrace_vstate_t *vstate;
13170 	int i, j, sz, hasprovs = 0;
13171 
13172 	mutex_enter(&dtrace_lock);
13173 	ASSERT(from->p_dtrace_helpers != NULL);
13174 	ASSERT(dtrace_helpers > 0);
13175 
13176 	help = from->p_dtrace_helpers;
13177 	newhelp = dtrace_helpers_create(to);
13178 	ASSERT(to->p_dtrace_helpers != NULL);
13179 
13180 	newhelp->dthps_generation = help->dthps_generation;
13181 	vstate = &newhelp->dthps_vstate;
13182 
13183 	/*
13184 	 * Duplicate the helper actions.
13185 	 */
13186 	for (i = 0; i < DTRACE_NHELPER_ACTIONS; i++) {
13187 		if ((helper = help->dthps_actions[i]) == NULL)
13188 			continue;
13189 
13190 		for (last = NULL; helper != NULL; helper = helper->dtha_next) {
13191 			new = kmem_zalloc(sizeof (dtrace_helper_action_t),
13192 			    KM_SLEEP);
13193 			new->dtha_generation = helper->dtha_generation;
13194 
13195 			if ((dp = helper->dtha_predicate) != NULL) {
13196 				dp = dtrace_difo_duplicate(dp, vstate);
13197 				new->dtha_predicate = dp;
13198 			}
13199 
13200 			new->dtha_nactions = helper->dtha_nactions;
13201 			sz = sizeof (dtrace_difo_t *) * new->dtha_nactions;
13202 			new->dtha_actions = kmem_alloc(sz, KM_SLEEP);
13203 
13204 			for (j = 0; j < new->dtha_nactions; j++) {
13205 				dtrace_difo_t *dp = helper->dtha_actions[j];
13206 
13207 				ASSERT(dp != NULL);
13208 				dp = dtrace_difo_duplicate(dp, vstate);
13209 				new->dtha_actions[j] = dp;
13210 			}
13211 
13212 			if (last != NULL) {
13213 				last->dtha_next = new;
13214 			} else {
13215 				newhelp->dthps_actions[i] = new;
13216 			}
13217 
13218 			last = new;
13219 		}
13220 	}
13221 
13222 	/*
13223 	 * Duplicate the helper providers and register them with the
13224 	 * DTrace framework.
13225 	 */
13226 	if (help->dthps_nprovs > 0) {
13227 		newhelp->dthps_nprovs = help->dthps_nprovs;
13228 		newhelp->dthps_maxprovs = help->dthps_nprovs;
13229 		newhelp->dthps_provs = kmem_alloc(newhelp->dthps_nprovs *
13230 		    sizeof (dtrace_helper_provider_t *), KM_SLEEP);
13231 		for (i = 0; i < newhelp->dthps_nprovs; i++) {
13232 			newhelp->dthps_provs[i] = help->dthps_provs[i];
13233 			newhelp->dthps_provs[i]->dthp_ref++;
13234 		}
13235 
13236 		hasprovs = 1;
13237 	}
13238 
13239 	mutex_exit(&dtrace_lock);
13240 
13241 	if (hasprovs)
13242 		dtrace_helper_provider_register(to, newhelp, NULL);
13243 }
13244 
13245 /*
13246  * DTrace Hook Functions
13247  */
13248 static void
13249 dtrace_module_loaded(struct modctl *ctl)
13250 {
13251 	dtrace_provider_t *prv;
13252 
13253 	mutex_enter(&dtrace_provider_lock);
13254 	mutex_enter(&mod_lock);
13255 
13256 	ASSERT(ctl->mod_busy);
13257 
13258 	/*
13259 	 * We're going to call each providers per-module provide operation
13260 	 * specifying only this module.
13261 	 */
13262 	for (prv = dtrace_provider; prv != NULL; prv = prv->dtpv_next)
13263 		prv->dtpv_pops.dtps_provide_module(prv->dtpv_arg, ctl);
13264 
13265 	mutex_exit(&mod_lock);
13266 	mutex_exit(&dtrace_provider_lock);
13267 
13268 	/*
13269 	 * If we have any retained enablings, we need to match against them.
13270 	 * Enabling probes requires that cpu_lock be held, and we cannot hold
13271 	 * cpu_lock here -- it is legal for cpu_lock to be held when loading a
13272 	 * module.  (In particular, this happens when loading scheduling
13273 	 * classes.)  So if we have any retained enablings, we need to dispatch
13274 	 * our task queue to do the match for us.
13275 	 */
13276 	mutex_enter(&dtrace_lock);
13277 
13278 	if (dtrace_retained == NULL) {
13279 		mutex_exit(&dtrace_lock);
13280 		return;
13281 	}
13282 
13283 	(void) taskq_dispatch(dtrace_taskq,
13284 	    (task_func_t *)dtrace_enabling_matchall, NULL, TQ_SLEEP);
13285 
13286 	mutex_exit(&dtrace_lock);
13287 
13288 	/*
13289 	 * And now, for a little heuristic sleaze:  in general, we want to
13290 	 * match modules as soon as they load.  However, we cannot guarantee
13291 	 * this, because it would lead us to the lock ordering violation
13292 	 * outlined above.  The common case, of course, is that cpu_lock is
13293 	 * _not_ held -- so we delay here for a clock tick, hoping that that's
13294 	 * long enough for the task queue to do its work.  If it's not, it's
13295 	 * not a serious problem -- it just means that the module that we
13296 	 * just loaded may not be immediately instrumentable.
13297 	 */
13298 	delay(1);
13299 }
13300 
13301 static void
13302 dtrace_module_unloaded(struct modctl *ctl)
13303 {
13304 	dtrace_probe_t template, *probe, *first, *next;
13305 	dtrace_provider_t *prov;
13306 
13307 	template.dtpr_mod = ctl->mod_modname;
13308 
13309 	mutex_enter(&dtrace_provider_lock);
13310 	mutex_enter(&mod_lock);
13311 	mutex_enter(&dtrace_lock);
13312 
13313 	if (dtrace_bymod == NULL) {
13314 		/*
13315 		 * The DTrace module is loaded (obviously) but not attached;
13316 		 * we don't have any work to do.
13317 		 */
13318 		mutex_exit(&dtrace_provider_lock);
13319 		mutex_exit(&mod_lock);
13320 		mutex_exit(&dtrace_lock);
13321 		return;
13322 	}
13323 
13324 	for (probe = first = dtrace_hash_lookup(dtrace_bymod, &template);
13325 	    probe != NULL; probe = probe->dtpr_nextmod) {
13326 		if (probe->dtpr_ecb != NULL) {
13327 			mutex_exit(&dtrace_provider_lock);
13328 			mutex_exit(&mod_lock);
13329 			mutex_exit(&dtrace_lock);
13330 
13331 			/*
13332 			 * This shouldn't _actually_ be possible -- we're
13333 			 * unloading a module that has an enabled probe in it.
13334 			 * (It's normally up to the provider to make sure that
13335 			 * this can't happen.)  However, because dtps_enable()
13336 			 * doesn't have a failure mode, there can be an
13337 			 * enable/unload race.  Upshot:  we don't want to
13338 			 * assert, but we're not going to disable the
13339 			 * probe, either.
13340 			 */
13341 			if (dtrace_err_verbose) {
13342 				cmn_err(CE_WARN, "unloaded module '%s' had "
13343 				    "enabled probes", ctl->mod_modname);
13344 			}
13345 
13346 			return;
13347 		}
13348 	}
13349 
13350 	probe = first;
13351 
13352 	for (first = NULL; probe != NULL; probe = next) {
13353 		ASSERT(dtrace_probes[probe->dtpr_id - 1] == probe);
13354 
13355 		dtrace_probes[probe->dtpr_id - 1] = NULL;
13356 
13357 		next = probe->dtpr_nextmod;
13358 		dtrace_hash_remove(dtrace_bymod, probe);
13359 		dtrace_hash_remove(dtrace_byfunc, probe);
13360 		dtrace_hash_remove(dtrace_byname, probe);
13361 
13362 		if (first == NULL) {
13363 			first = probe;
13364 			probe->dtpr_nextmod = NULL;
13365 		} else {
13366 			probe->dtpr_nextmod = first;
13367 			first = probe;
13368 		}
13369 	}
13370 
13371 	/*
13372 	 * We've removed all of the module's probes from the hash chains and
13373 	 * from the probe array.  Now issue a dtrace_sync() to be sure that
13374 	 * everyone has cleared out from any probe array processing.
13375 	 */
13376 	dtrace_sync();
13377 
13378 	for (probe = first; probe != NULL; probe = first) {
13379 		first = probe->dtpr_nextmod;
13380 		prov = probe->dtpr_provider;
13381 		prov->dtpv_pops.dtps_destroy(prov->dtpv_arg, probe->dtpr_id,
13382 		    probe->dtpr_arg);
13383 		kmem_free(probe->dtpr_mod, strlen(probe->dtpr_mod) + 1);
13384 		kmem_free(probe->dtpr_func, strlen(probe->dtpr_func) + 1);
13385 		kmem_free(probe->dtpr_name, strlen(probe->dtpr_name) + 1);
13386 		vmem_free(dtrace_arena, (void *)(uintptr_t)probe->dtpr_id, 1);
13387 		kmem_free(probe, sizeof (dtrace_probe_t));
13388 	}
13389 
13390 	mutex_exit(&dtrace_lock);
13391 	mutex_exit(&mod_lock);
13392 	mutex_exit(&dtrace_provider_lock);
13393 }
13394 
13395 void
13396 dtrace_suspend(void)
13397 {
13398 	dtrace_probe_foreach(offsetof(dtrace_pops_t, dtps_suspend));
13399 }
13400 
13401 void
13402 dtrace_resume(void)
13403 {
13404 	dtrace_probe_foreach(offsetof(dtrace_pops_t, dtps_resume));
13405 }
13406 
13407 static int
13408 dtrace_cpu_setup(cpu_setup_t what, processorid_t cpu)
13409 {
13410 	ASSERT(MUTEX_HELD(&cpu_lock));
13411 	mutex_enter(&dtrace_lock);
13412 
13413 	switch (what) {
13414 	case CPU_CONFIG: {
13415 		dtrace_state_t *state;
13416 		dtrace_optval_t *opt, rs, c;
13417 
13418 		/*
13419 		 * For now, we only allocate a new buffer for anonymous state.
13420 		 */
13421 		if ((state = dtrace_anon.dta_state) == NULL)
13422 			break;
13423 
13424 		if (state->dts_activity != DTRACE_ACTIVITY_ACTIVE)
13425 			break;
13426 
13427 		opt = state->dts_options;
13428 		c = opt[DTRACEOPT_CPU];
13429 
13430 		if (c != DTRACE_CPUALL && c != DTRACEOPT_UNSET && c != cpu)
13431 			break;
13432 
13433 		/*
13434 		 * Regardless of what the actual policy is, we're going to
13435 		 * temporarily set our resize policy to be manual.  We're
13436 		 * also going to temporarily set our CPU option to denote
13437 		 * the newly configured CPU.
13438 		 */
13439 		rs = opt[DTRACEOPT_BUFRESIZE];
13440 		opt[DTRACEOPT_BUFRESIZE] = DTRACEOPT_BUFRESIZE_MANUAL;
13441 		opt[DTRACEOPT_CPU] = (dtrace_optval_t)cpu;
13442 
13443 		(void) dtrace_state_buffers(state);
13444 
13445 		opt[DTRACEOPT_BUFRESIZE] = rs;
13446 		opt[DTRACEOPT_CPU] = c;
13447 
13448 		break;
13449 	}
13450 
13451 	case CPU_UNCONFIG:
13452 		/*
13453 		 * We don't free the buffer in the CPU_UNCONFIG case.  (The
13454 		 * buffer will be freed when the consumer exits.)
13455 		 */
13456 		break;
13457 
13458 	default:
13459 		break;
13460 	}
13461 
13462 	mutex_exit(&dtrace_lock);
13463 	return (0);
13464 }
13465 
13466 static void
13467 dtrace_cpu_setup_initial(processorid_t cpu)
13468 {
13469 	(void) dtrace_cpu_setup(CPU_CONFIG, cpu);
13470 }
13471 
13472 static void
13473 dtrace_toxrange_add(uintptr_t base, uintptr_t limit)
13474 {
13475 	if (dtrace_toxranges >= dtrace_toxranges_max) {
13476 		int osize, nsize;
13477 		dtrace_toxrange_t *range;
13478 
13479 		osize = dtrace_toxranges_max * sizeof (dtrace_toxrange_t);
13480 
13481 		if (osize == 0) {
13482 			ASSERT(dtrace_toxrange == NULL);
13483 			ASSERT(dtrace_toxranges_max == 0);
13484 			dtrace_toxranges_max = 1;
13485 		} else {
13486 			dtrace_toxranges_max <<= 1;
13487 		}
13488 
13489 		nsize = dtrace_toxranges_max * sizeof (dtrace_toxrange_t);
13490 		range = kmem_zalloc(nsize, KM_SLEEP);
13491 
13492 		if (dtrace_toxrange != NULL) {
13493 			ASSERT(osize != 0);
13494 			bcopy(dtrace_toxrange, range, osize);
13495 			kmem_free(dtrace_toxrange, osize);
13496 		}
13497 
13498 		dtrace_toxrange = range;
13499 	}
13500 
13501 	ASSERT(dtrace_toxrange[dtrace_toxranges].dtt_base == NULL);
13502 	ASSERT(dtrace_toxrange[dtrace_toxranges].dtt_limit == NULL);
13503 
13504 	dtrace_toxrange[dtrace_toxranges].dtt_base = base;
13505 	dtrace_toxrange[dtrace_toxranges].dtt_limit = limit;
13506 	dtrace_toxranges++;
13507 }
13508 
13509 /*
13510  * DTrace Driver Cookbook Functions
13511  */
13512 /*ARGSUSED*/
13513 static int
13514 dtrace_attach(dev_info_t *devi, ddi_attach_cmd_t cmd)
13515 {
13516 	dtrace_provider_id_t id;
13517 	dtrace_state_t *state = NULL;
13518 	dtrace_enabling_t *enab;
13519 
13520 	mutex_enter(&cpu_lock);
13521 	mutex_enter(&dtrace_provider_lock);
13522 	mutex_enter(&dtrace_lock);
13523 
13524 	if (ddi_soft_state_init(&dtrace_softstate,
13525 	    sizeof (dtrace_state_t), 0) != 0) {
13526 		cmn_err(CE_NOTE, "/dev/dtrace failed to initialize soft state");
13527 		mutex_exit(&cpu_lock);
13528 		mutex_exit(&dtrace_provider_lock);
13529 		mutex_exit(&dtrace_lock);
13530 		return (DDI_FAILURE);
13531 	}
13532 
13533 	if (ddi_create_minor_node(devi, DTRACEMNR_DTRACE, S_IFCHR,
13534 	    DTRACEMNRN_DTRACE, DDI_PSEUDO, NULL) == DDI_FAILURE ||
13535 	    ddi_create_minor_node(devi, DTRACEMNR_HELPER, S_IFCHR,
13536 	    DTRACEMNRN_HELPER, DDI_PSEUDO, NULL) == DDI_FAILURE) {
13537 		cmn_err(CE_NOTE, "/dev/dtrace couldn't create minor nodes");
13538 		ddi_remove_minor_node(devi, NULL);
13539 		ddi_soft_state_fini(&dtrace_softstate);
13540 		mutex_exit(&cpu_lock);
13541 		mutex_exit(&dtrace_provider_lock);
13542 		mutex_exit(&dtrace_lock);
13543 		return (DDI_FAILURE);
13544 	}
13545 
13546 	ddi_report_dev(devi);
13547 	dtrace_devi = devi;
13548 
13549 	dtrace_modload = dtrace_module_loaded;
13550 	dtrace_modunload = dtrace_module_unloaded;
13551 	dtrace_cpu_init = dtrace_cpu_setup_initial;
13552 	dtrace_helpers_cleanup = dtrace_helpers_destroy;
13553 	dtrace_helpers_fork = dtrace_helpers_duplicate;
13554 	dtrace_cpustart_init = dtrace_suspend;
13555 	dtrace_cpustart_fini = dtrace_resume;
13556 	dtrace_debugger_init = dtrace_suspend;
13557 	dtrace_debugger_fini = dtrace_resume;
13558 	dtrace_kreloc_init = dtrace_suspend;
13559 	dtrace_kreloc_fini = dtrace_resume;
13560 
13561 	register_cpu_setup_func((cpu_setup_func_t *)dtrace_cpu_setup, NULL);
13562 
13563 	ASSERT(MUTEX_HELD(&cpu_lock));
13564 
13565 	dtrace_arena = vmem_create("dtrace", (void *)1, UINT32_MAX, 1,
13566 	    NULL, NULL, NULL, 0, VM_SLEEP | VMC_IDENTIFIER);
13567 	dtrace_minor = vmem_create("dtrace_minor", (void *)DTRACEMNRN_CLONE,
13568 	    UINT32_MAX - DTRACEMNRN_CLONE, 1, NULL, NULL, NULL, 0,
13569 	    VM_SLEEP | VMC_IDENTIFIER);
13570 	dtrace_taskq = taskq_create("dtrace_taskq", 1, maxclsyspri,
13571 	    1, INT_MAX, 0);
13572 
13573 	dtrace_state_cache = kmem_cache_create("dtrace_state_cache",
13574 	    sizeof (dtrace_dstate_percpu_t) * NCPU, DTRACE_STATE_ALIGN,
13575 	    NULL, NULL, NULL, NULL, NULL, 0);
13576 
13577 	ASSERT(MUTEX_HELD(&cpu_lock));
13578 	dtrace_bymod = dtrace_hash_create(offsetof(dtrace_probe_t, dtpr_mod),
13579 	    offsetof(dtrace_probe_t, dtpr_nextmod),
13580 	    offsetof(dtrace_probe_t, dtpr_prevmod));
13581 
13582 	dtrace_byfunc = dtrace_hash_create(offsetof(dtrace_probe_t, dtpr_func),
13583 	    offsetof(dtrace_probe_t, dtpr_nextfunc),
13584 	    offsetof(dtrace_probe_t, dtpr_prevfunc));
13585 
13586 	dtrace_byname = dtrace_hash_create(offsetof(dtrace_probe_t, dtpr_name),
13587 	    offsetof(dtrace_probe_t, dtpr_nextname),
13588 	    offsetof(dtrace_probe_t, dtpr_prevname));
13589 
13590 	if (dtrace_retain_max < 1) {
13591 		cmn_err(CE_WARN, "illegal value (%lu) for dtrace_retain_max; "
13592 		    "setting to 1", dtrace_retain_max);
13593 		dtrace_retain_max = 1;
13594 	}
13595 
13596 	/*
13597 	 * Now discover our toxic ranges.
13598 	 */
13599 	dtrace_toxic_ranges(dtrace_toxrange_add);
13600 
13601 	/*
13602 	 * Before we register ourselves as a provider to our own framework,
13603 	 * we would like to assert that dtrace_provider is NULL -- but that's
13604 	 * not true if we were loaded as a dependency of a DTrace provider.
13605 	 * Once we've registered, we can assert that dtrace_provider is our
13606 	 * pseudo provider.
13607 	 */
13608 	(void) dtrace_register("dtrace", &dtrace_provider_attr,
13609 	    DTRACE_PRIV_NONE, 0, &dtrace_provider_ops, NULL, &id);
13610 
13611 	ASSERT(dtrace_provider != NULL);
13612 	ASSERT((dtrace_provider_id_t)dtrace_provider == id);
13613 
13614 	dtrace_probeid_begin = dtrace_probe_create((dtrace_provider_id_t)
13615 	    dtrace_provider, NULL, NULL, "BEGIN", 0, NULL);
13616 	dtrace_probeid_end = dtrace_probe_create((dtrace_provider_id_t)
13617 	    dtrace_provider, NULL, NULL, "END", 0, NULL);
13618 	dtrace_probeid_error = dtrace_probe_create((dtrace_provider_id_t)
13619 	    dtrace_provider, NULL, NULL, "ERROR", 1, NULL);
13620 
13621 	dtrace_anon_property();
13622 	mutex_exit(&cpu_lock);
13623 
13624 	/*
13625 	 * If DTrace helper tracing is enabled, we need to allocate the
13626 	 * trace buffer and initialize the values.
13627 	 */
13628 	if (dtrace_helptrace_enabled) {
13629 		ASSERT(dtrace_helptrace_buffer == NULL);
13630 		dtrace_helptrace_buffer =
13631 		    kmem_zalloc(dtrace_helptrace_bufsize, KM_SLEEP);
13632 		dtrace_helptrace_next = 0;
13633 	}
13634 
13635 	/*
13636 	 * If there are already providers, we must ask them to provide their
13637 	 * probes, and then match any anonymous enabling against them.  Note
13638 	 * that there should be no other retained enablings at this time:
13639 	 * the only retained enablings at this time should be the anonymous
13640 	 * enabling.
13641 	 */
13642 	if (dtrace_anon.dta_enabling != NULL) {
13643 		ASSERT(dtrace_retained == dtrace_anon.dta_enabling);
13644 
13645 		dtrace_enabling_provide(NULL);
13646 		state = dtrace_anon.dta_state;
13647 
13648 		/*
13649 		 * We couldn't hold cpu_lock across the above call to
13650 		 * dtrace_enabling_provide(), but we must hold it to actually
13651 		 * enable the probes.  We have to drop all of our locks, pick
13652 		 * up cpu_lock, and regain our locks before matching the
13653 		 * retained anonymous enabling.
13654 		 */
13655 		mutex_exit(&dtrace_lock);
13656 		mutex_exit(&dtrace_provider_lock);
13657 
13658 		mutex_enter(&cpu_lock);
13659 		mutex_enter(&dtrace_provider_lock);
13660 		mutex_enter(&dtrace_lock);
13661 
13662 		if ((enab = dtrace_anon.dta_enabling) != NULL)
13663 			(void) dtrace_enabling_match(enab, NULL);
13664 
13665 		mutex_exit(&cpu_lock);
13666 	}
13667 
13668 	mutex_exit(&dtrace_lock);
13669 	mutex_exit(&dtrace_provider_lock);
13670 
13671 	if (state != NULL) {
13672 		/*
13673 		 * If we created any anonymous state, set it going now.
13674 		 */
13675 		(void) dtrace_state_go(state, &dtrace_anon.dta_beganon);
13676 	}
13677 
13678 	return (DDI_SUCCESS);
13679 }
13680 
13681 /*ARGSUSED*/
13682 static int
13683 dtrace_open(dev_t *devp, int flag, int otyp, cred_t *cred_p)
13684 {
13685 	dtrace_state_t *state;
13686 	uint32_t priv;
13687 	uid_t uid;
13688 	zoneid_t zoneid;
13689 
13690 	if (getminor(*devp) == DTRACEMNRN_HELPER)
13691 		return (0);
13692 
13693 	/*
13694 	 * If this wasn't an open with the "helper" minor, then it must be
13695 	 * the "dtrace" minor.
13696 	 */
13697 	ASSERT(getminor(*devp) == DTRACEMNRN_DTRACE);
13698 
13699 	/*
13700 	 * If no DTRACE_PRIV_* bits are set in the credential, then the
13701 	 * caller lacks sufficient permission to do anything with DTrace.
13702 	 */
13703 	dtrace_cred2priv(cred_p, &priv, &uid, &zoneid);
13704 	if (priv == DTRACE_PRIV_NONE)
13705 		return (EACCES);
13706 
13707 	/*
13708 	 * Ask all providers to provide all their probes.
13709 	 */
13710 	mutex_enter(&dtrace_provider_lock);
13711 	dtrace_probe_provide(NULL, NULL);
13712 	mutex_exit(&dtrace_provider_lock);
13713 
13714 	mutex_enter(&cpu_lock);
13715 	mutex_enter(&dtrace_lock);
13716 	dtrace_opens++;
13717 	dtrace_membar_producer();
13718 
13719 	/*
13720 	 * If the kernel debugger is active (that is, if the kernel debugger
13721 	 * modified text in some way), we won't allow the open.
13722 	 */
13723 	if (kdi_dtrace_set(KDI_DTSET_DTRACE_ACTIVATE) != 0) {
13724 		dtrace_opens--;
13725 		mutex_exit(&cpu_lock);
13726 		mutex_exit(&dtrace_lock);
13727 		return (EBUSY);
13728 	}
13729 
13730 	state = dtrace_state_create(devp, cred_p);
13731 	mutex_exit(&cpu_lock);
13732 
13733 	if (state == NULL) {
13734 		if (--dtrace_opens == 0)
13735 			(void) kdi_dtrace_set(KDI_DTSET_DTRACE_DEACTIVATE);
13736 		mutex_exit(&dtrace_lock);
13737 		return (EAGAIN);
13738 	}
13739 
13740 	mutex_exit(&dtrace_lock);
13741 
13742 	return (0);
13743 }
13744 
13745 /*ARGSUSED*/
13746 static int
13747 dtrace_close(dev_t dev, int flag, int otyp, cred_t *cred_p)
13748 {
13749 	minor_t minor = getminor(dev);
13750 	dtrace_state_t *state;
13751 
13752 	if (minor == DTRACEMNRN_HELPER)
13753 		return (0);
13754 
13755 	state = ddi_get_soft_state(dtrace_softstate, minor);
13756 
13757 	mutex_enter(&cpu_lock);
13758 	mutex_enter(&dtrace_lock);
13759 
13760 	if (state->dts_anon) {
13761 		/*
13762 		 * There is anonymous state. Destroy that first.
13763 		 */
13764 		ASSERT(dtrace_anon.dta_state == NULL);
13765 		dtrace_state_destroy(state->dts_anon);
13766 	}
13767 
13768 	dtrace_state_destroy(state);
13769 	ASSERT(dtrace_opens > 0);
13770 	if (--dtrace_opens == 0)
13771 		(void) kdi_dtrace_set(KDI_DTSET_DTRACE_DEACTIVATE);
13772 
13773 	mutex_exit(&dtrace_lock);
13774 	mutex_exit(&cpu_lock);
13775 
13776 	return (0);
13777 }
13778 
13779 /*ARGSUSED*/
13780 static int
13781 dtrace_ioctl_helper(int cmd, intptr_t arg, int *rv)
13782 {
13783 	int rval;
13784 	dof_helper_t help, *dhp = NULL;
13785 
13786 	switch (cmd) {
13787 	case DTRACEHIOC_ADDDOF:
13788 		if (copyin((void *)arg, &help, sizeof (help)) != 0) {
13789 			dtrace_dof_error(NULL, "failed to copyin DOF helper");
13790 			return (EFAULT);
13791 		}
13792 
13793 		dhp = &help;
13794 		arg = (intptr_t)help.dofhp_dof;
13795 		/*FALLTHROUGH*/
13796 
13797 	case DTRACEHIOC_ADD: {
13798 		dof_hdr_t *dof = dtrace_dof_copyin(arg, &rval);
13799 
13800 		if (dof == NULL)
13801 			return (rval);
13802 
13803 		mutex_enter(&dtrace_lock);
13804 
13805 		/*
13806 		 * dtrace_helper_slurp() takes responsibility for the dof --
13807 		 * it may free it now or it may save it and free it later.
13808 		 */
13809 		if ((rval = dtrace_helper_slurp(dof, dhp)) != -1) {
13810 			*rv = rval;
13811 			rval = 0;
13812 		} else {
13813 			rval = EINVAL;
13814 		}
13815 
13816 		mutex_exit(&dtrace_lock);
13817 		return (rval);
13818 	}
13819 
13820 	case DTRACEHIOC_REMOVE: {
13821 		mutex_enter(&dtrace_lock);
13822 		rval = dtrace_helper_destroygen(arg);
13823 		mutex_exit(&dtrace_lock);
13824 
13825 		return (rval);
13826 	}
13827 
13828 	default:
13829 		break;
13830 	}
13831 
13832 	return (ENOTTY);
13833 }
13834 
13835 /*ARGSUSED*/
13836 static int
13837 dtrace_ioctl(dev_t dev, int cmd, intptr_t arg, int md, cred_t *cr, int *rv)
13838 {
13839 	minor_t minor = getminor(dev);
13840 	dtrace_state_t *state;
13841 	int rval;
13842 
13843 	if (minor == DTRACEMNRN_HELPER)
13844 		return (dtrace_ioctl_helper(cmd, arg, rv));
13845 
13846 	state = ddi_get_soft_state(dtrace_softstate, minor);
13847 
13848 	if (state->dts_anon) {
13849 		ASSERT(dtrace_anon.dta_state == NULL);
13850 		state = state->dts_anon;
13851 	}
13852 
13853 	switch (cmd) {
13854 	case DTRACEIOC_PROVIDER: {
13855 		dtrace_providerdesc_t pvd;
13856 		dtrace_provider_t *pvp;
13857 
13858 		if (copyin((void *)arg, &pvd, sizeof (pvd)) != 0)
13859 			return (EFAULT);
13860 
13861 		pvd.dtvd_name[DTRACE_PROVNAMELEN - 1] = '\0';
13862 		mutex_enter(&dtrace_provider_lock);
13863 
13864 		for (pvp = dtrace_provider; pvp != NULL; pvp = pvp->dtpv_next) {
13865 			if (strcmp(pvp->dtpv_name, pvd.dtvd_name) == 0)
13866 				break;
13867 		}
13868 
13869 		mutex_exit(&dtrace_provider_lock);
13870 
13871 		if (pvp == NULL)
13872 			return (ESRCH);
13873 
13874 		bcopy(&pvp->dtpv_priv, &pvd.dtvd_priv, sizeof (dtrace_ppriv_t));
13875 		bcopy(&pvp->dtpv_attr, &pvd.dtvd_attr, sizeof (dtrace_pattr_t));
13876 		if (copyout(&pvd, (void *)arg, sizeof (pvd)) != 0)
13877 			return (EFAULT);
13878 
13879 		return (0);
13880 	}
13881 
13882 	case DTRACEIOC_EPROBE: {
13883 		dtrace_eprobedesc_t epdesc;
13884 		dtrace_ecb_t *ecb;
13885 		dtrace_action_t *act;
13886 		void *buf;
13887 		size_t size;
13888 		uintptr_t dest;
13889 		int nrecs;
13890 
13891 		if (copyin((void *)arg, &epdesc, sizeof (epdesc)) != 0)
13892 			return (EFAULT);
13893 
13894 		mutex_enter(&dtrace_lock);
13895 
13896 		if ((ecb = dtrace_epid2ecb(state, epdesc.dtepd_epid)) == NULL) {
13897 			mutex_exit(&dtrace_lock);
13898 			return (EINVAL);
13899 		}
13900 
13901 		if (ecb->dte_probe == NULL) {
13902 			mutex_exit(&dtrace_lock);
13903 			return (EINVAL);
13904 		}
13905 
13906 		epdesc.dtepd_probeid = ecb->dte_probe->dtpr_id;
13907 		epdesc.dtepd_uarg = ecb->dte_uarg;
13908 		epdesc.dtepd_size = ecb->dte_size;
13909 
13910 		nrecs = epdesc.dtepd_nrecs;
13911 		epdesc.dtepd_nrecs = 0;
13912 		for (act = ecb->dte_action; act != NULL; act = act->dta_next) {
13913 			if (DTRACEACT_ISAGG(act->dta_kind) || act->dta_intuple)
13914 				continue;
13915 
13916 			epdesc.dtepd_nrecs++;
13917 		}
13918 
13919 		/*
13920 		 * Now that we have the size, we need to allocate a temporary
13921 		 * buffer in which to store the complete description.  We need
13922 		 * the temporary buffer to be able to drop dtrace_lock()
13923 		 * across the copyout(), below.
13924 		 */
13925 		size = sizeof (dtrace_eprobedesc_t) +
13926 		    (epdesc.dtepd_nrecs * sizeof (dtrace_recdesc_t));
13927 
13928 		buf = kmem_alloc(size, KM_SLEEP);
13929 		dest = (uintptr_t)buf;
13930 
13931 		bcopy(&epdesc, (void *)dest, sizeof (epdesc));
13932 		dest += offsetof(dtrace_eprobedesc_t, dtepd_rec[0]);
13933 
13934 		for (act = ecb->dte_action; act != NULL; act = act->dta_next) {
13935 			if (DTRACEACT_ISAGG(act->dta_kind) || act->dta_intuple)
13936 				continue;
13937 
13938 			if (nrecs-- == 0)
13939 				break;
13940 
13941 			bcopy(&act->dta_rec, (void *)dest,
13942 			    sizeof (dtrace_recdesc_t));
13943 			dest += sizeof (dtrace_recdesc_t);
13944 		}
13945 
13946 		mutex_exit(&dtrace_lock);
13947 
13948 		if (copyout(buf, (void *)arg, dest - (uintptr_t)buf) != 0) {
13949 			kmem_free(buf, size);
13950 			return (EFAULT);
13951 		}
13952 
13953 		kmem_free(buf, size);
13954 		return (0);
13955 	}
13956 
13957 	case DTRACEIOC_AGGDESC: {
13958 		dtrace_aggdesc_t aggdesc;
13959 		dtrace_action_t *act;
13960 		dtrace_aggregation_t *agg;
13961 		int nrecs;
13962 		uint32_t offs;
13963 		dtrace_recdesc_t *lrec;
13964 		void *buf;
13965 		size_t size;
13966 		uintptr_t dest;
13967 
13968 		if (copyin((void *)arg, &aggdesc, sizeof (aggdesc)) != 0)
13969 			return (EFAULT);
13970 
13971 		mutex_enter(&dtrace_lock);
13972 
13973 		if ((agg = dtrace_aggid2agg(state, aggdesc.dtagd_id)) == NULL) {
13974 			mutex_exit(&dtrace_lock);
13975 			return (EINVAL);
13976 		}
13977 
13978 		aggdesc.dtagd_epid = agg->dtag_ecb->dte_epid;
13979 
13980 		nrecs = aggdesc.dtagd_nrecs;
13981 		aggdesc.dtagd_nrecs = 0;
13982 
13983 		offs = agg->dtag_base;
13984 		lrec = &agg->dtag_action.dta_rec;
13985 		aggdesc.dtagd_size = lrec->dtrd_offset + lrec->dtrd_size - offs;
13986 
13987 		for (act = agg->dtag_first; ; act = act->dta_next) {
13988 			ASSERT(act->dta_intuple ||
13989 			    DTRACEACT_ISAGG(act->dta_kind));
13990 
13991 			/*
13992 			 * If this action has a record size of zero, it
13993 			 * denotes an argument to the aggregating action.
13994 			 * Because the presence of this record doesn't (or
13995 			 * shouldn't) affect the way the data is interpreted,
13996 			 * we don't copy it out to save user-level the
13997 			 * confusion of dealing with a zero-length record.
13998 			 */
13999 			if (act->dta_rec.dtrd_size == 0) {
14000 				ASSERT(agg->dtag_hasarg);
14001 				continue;
14002 			}
14003 
14004 			aggdesc.dtagd_nrecs++;
14005 
14006 			if (act == &agg->dtag_action)
14007 				break;
14008 		}
14009 
14010 		/*
14011 		 * Now that we have the size, we need to allocate a temporary
14012 		 * buffer in which to store the complete description.  We need
14013 		 * the temporary buffer to be able to drop dtrace_lock()
14014 		 * across the copyout(), below.
14015 		 */
14016 		size = sizeof (dtrace_aggdesc_t) +
14017 		    (aggdesc.dtagd_nrecs * sizeof (dtrace_recdesc_t));
14018 
14019 		buf = kmem_alloc(size, KM_SLEEP);
14020 		dest = (uintptr_t)buf;
14021 
14022 		bcopy(&aggdesc, (void *)dest, sizeof (aggdesc));
14023 		dest += offsetof(dtrace_aggdesc_t, dtagd_rec[0]);
14024 
14025 		for (act = agg->dtag_first; ; act = act->dta_next) {
14026 			dtrace_recdesc_t rec = act->dta_rec;
14027 
14028 			/*
14029 			 * See the comment in the above loop for why we pass
14030 			 * over zero-length records.
14031 			 */
14032 			if (rec.dtrd_size == 0) {
14033 				ASSERT(agg->dtag_hasarg);
14034 				continue;
14035 			}
14036 
14037 			if (nrecs-- == 0)
14038 				break;
14039 
14040 			rec.dtrd_offset -= offs;
14041 			bcopy(&rec, (void *)dest, sizeof (rec));
14042 			dest += sizeof (dtrace_recdesc_t);
14043 
14044 			if (act == &agg->dtag_action)
14045 				break;
14046 		}
14047 
14048 		mutex_exit(&dtrace_lock);
14049 
14050 		if (copyout(buf, (void *)arg, dest - (uintptr_t)buf) != 0) {
14051 			kmem_free(buf, size);
14052 			return (EFAULT);
14053 		}
14054 
14055 		kmem_free(buf, size);
14056 		return (0);
14057 	}
14058 
14059 	case DTRACEIOC_ENABLE: {
14060 		dof_hdr_t *dof;
14061 		dtrace_enabling_t *enab = NULL;
14062 		dtrace_vstate_t *vstate;
14063 		int err = 0;
14064 
14065 		*rv = 0;
14066 
14067 		/*
14068 		 * If a NULL argument has been passed, we take this as our
14069 		 * cue to reevaluate our enablings.
14070 		 */
14071 		if (arg == NULL) {
14072 			mutex_enter(&cpu_lock);
14073 			mutex_enter(&dtrace_lock);
14074 			err = dtrace_enabling_matchstate(state, rv);
14075 			mutex_exit(&dtrace_lock);
14076 			mutex_exit(&cpu_lock);
14077 
14078 			return (err);
14079 		}
14080 
14081 		if ((dof = dtrace_dof_copyin(arg, &rval)) == NULL)
14082 			return (rval);
14083 
14084 		mutex_enter(&cpu_lock);
14085 		mutex_enter(&dtrace_lock);
14086 		vstate = &state->dts_vstate;
14087 
14088 		if (state->dts_activity != DTRACE_ACTIVITY_INACTIVE) {
14089 			mutex_exit(&dtrace_lock);
14090 			mutex_exit(&cpu_lock);
14091 			dtrace_dof_destroy(dof);
14092 			return (EBUSY);
14093 		}
14094 
14095 		if (dtrace_dof_slurp(dof, vstate, cr, &enab, 0, B_TRUE) != 0) {
14096 			mutex_exit(&dtrace_lock);
14097 			mutex_exit(&cpu_lock);
14098 			dtrace_dof_destroy(dof);
14099 			return (EINVAL);
14100 		}
14101 
14102 		if ((rval = dtrace_dof_options(dof, state)) != 0) {
14103 			dtrace_enabling_destroy(enab);
14104 			mutex_exit(&dtrace_lock);
14105 			mutex_exit(&cpu_lock);
14106 			dtrace_dof_destroy(dof);
14107 			return (rval);
14108 		}
14109 
14110 		if ((err = dtrace_enabling_match(enab, rv)) == 0) {
14111 			err = dtrace_enabling_retain(enab);
14112 		} else {
14113 			dtrace_enabling_destroy(enab);
14114 		}
14115 
14116 		mutex_exit(&cpu_lock);
14117 		mutex_exit(&dtrace_lock);
14118 		dtrace_dof_destroy(dof);
14119 
14120 		return (err);
14121 	}
14122 
14123 	case DTRACEIOC_REPLICATE: {
14124 		dtrace_repldesc_t desc;
14125 		dtrace_probedesc_t *match = &desc.dtrpd_match;
14126 		dtrace_probedesc_t *create = &desc.dtrpd_create;
14127 		int err;
14128 
14129 		if (copyin((void *)arg, &desc, sizeof (desc)) != 0)
14130 			return (EFAULT);
14131 
14132 		match->dtpd_provider[DTRACE_PROVNAMELEN - 1] = '\0';
14133 		match->dtpd_mod[DTRACE_MODNAMELEN - 1] = '\0';
14134 		match->dtpd_func[DTRACE_FUNCNAMELEN - 1] = '\0';
14135 		match->dtpd_name[DTRACE_NAMELEN - 1] = '\0';
14136 
14137 		create->dtpd_provider[DTRACE_PROVNAMELEN - 1] = '\0';
14138 		create->dtpd_mod[DTRACE_MODNAMELEN - 1] = '\0';
14139 		create->dtpd_func[DTRACE_FUNCNAMELEN - 1] = '\0';
14140 		create->dtpd_name[DTRACE_NAMELEN - 1] = '\0';
14141 
14142 		mutex_enter(&dtrace_lock);
14143 		err = dtrace_enabling_replicate(state, match, create);
14144 		mutex_exit(&dtrace_lock);
14145 
14146 		return (err);
14147 	}
14148 
14149 	case DTRACEIOC_PROBEMATCH:
14150 	case DTRACEIOC_PROBES: {
14151 		dtrace_probe_t *probe = NULL;
14152 		dtrace_probedesc_t desc;
14153 		dtrace_probekey_t pkey;
14154 		dtrace_id_t i;
14155 		int m = 0;
14156 		uint32_t priv;
14157 		uid_t uid;
14158 		zoneid_t zoneid;
14159 
14160 		if (copyin((void *)arg, &desc, sizeof (desc)) != 0)
14161 			return (EFAULT);
14162 
14163 		desc.dtpd_provider[DTRACE_PROVNAMELEN - 1] = '\0';
14164 		desc.dtpd_mod[DTRACE_MODNAMELEN - 1] = '\0';
14165 		desc.dtpd_func[DTRACE_FUNCNAMELEN - 1] = '\0';
14166 		desc.dtpd_name[DTRACE_NAMELEN - 1] = '\0';
14167 
14168 		/*
14169 		 * Before we attempt to match this probe, we want to give
14170 		 * all providers the opportunity to provide it.
14171 		 */
14172 		if (desc.dtpd_id == DTRACE_IDNONE) {
14173 			mutex_enter(&dtrace_provider_lock);
14174 			dtrace_probe_provide(&desc, NULL);
14175 			mutex_exit(&dtrace_provider_lock);
14176 			desc.dtpd_id++;
14177 		}
14178 
14179 		if (cmd == DTRACEIOC_PROBEMATCH)  {
14180 			dtrace_probekey(&desc, &pkey);
14181 			pkey.dtpk_id = DTRACE_IDNONE;
14182 		}
14183 
14184 		dtrace_cred2priv(cr, &priv, &uid, &zoneid);
14185 
14186 		mutex_enter(&dtrace_lock);
14187 
14188 		if (cmd == DTRACEIOC_PROBEMATCH) {
14189 			for (i = desc.dtpd_id; i <= dtrace_nprobes; i++) {
14190 				if ((probe = dtrace_probes[i - 1]) != NULL &&
14191 				    (m = dtrace_match_probe(probe, &pkey,
14192 				    priv, uid, zoneid)) != 0)
14193 					break;
14194 			}
14195 
14196 			if (m < 0) {
14197 				mutex_exit(&dtrace_lock);
14198 				return (EINVAL);
14199 			}
14200 
14201 		} else {
14202 			for (i = desc.dtpd_id; i <= dtrace_nprobes; i++) {
14203 				if ((probe = dtrace_probes[i - 1]) != NULL &&
14204 				    dtrace_match_priv(probe, priv, uid, zoneid))
14205 					break;
14206 			}
14207 		}
14208 
14209 		if (probe == NULL) {
14210 			mutex_exit(&dtrace_lock);
14211 			return (ESRCH);
14212 		}
14213 
14214 		dtrace_probe_description(probe, &desc);
14215 		mutex_exit(&dtrace_lock);
14216 
14217 		if (copyout(&desc, (void *)arg, sizeof (desc)) != 0)
14218 			return (EFAULT);
14219 
14220 		return (0);
14221 	}
14222 
14223 	case DTRACEIOC_PROBEARG: {
14224 		dtrace_argdesc_t desc;
14225 		dtrace_probe_t *probe;
14226 		dtrace_provider_t *prov;
14227 
14228 		if (copyin((void *)arg, &desc, sizeof (desc)) != 0)
14229 			return (EFAULT);
14230 
14231 		if (desc.dtargd_id == DTRACE_IDNONE)
14232 			return (EINVAL);
14233 
14234 		if (desc.dtargd_ndx == DTRACE_ARGNONE)
14235 			return (EINVAL);
14236 
14237 		mutex_enter(&dtrace_provider_lock);
14238 		mutex_enter(&mod_lock);
14239 		mutex_enter(&dtrace_lock);
14240 
14241 		if (desc.dtargd_id > dtrace_nprobes) {
14242 			mutex_exit(&dtrace_lock);
14243 			mutex_exit(&mod_lock);
14244 			mutex_exit(&dtrace_provider_lock);
14245 			return (EINVAL);
14246 		}
14247 
14248 		if ((probe = dtrace_probes[desc.dtargd_id - 1]) == NULL) {
14249 			mutex_exit(&dtrace_lock);
14250 			mutex_exit(&mod_lock);
14251 			mutex_exit(&dtrace_provider_lock);
14252 			return (EINVAL);
14253 		}
14254 
14255 		mutex_exit(&dtrace_lock);
14256 
14257 		prov = probe->dtpr_provider;
14258 
14259 		if (prov->dtpv_pops.dtps_getargdesc == NULL) {
14260 			/*
14261 			 * There isn't any typed information for this probe.
14262 			 * Set the argument number to DTRACE_ARGNONE.
14263 			 */
14264 			desc.dtargd_ndx = DTRACE_ARGNONE;
14265 		} else {
14266 			desc.dtargd_native[0] = '\0';
14267 			desc.dtargd_xlate[0] = '\0';
14268 			desc.dtargd_mapping = desc.dtargd_ndx;
14269 
14270 			prov->dtpv_pops.dtps_getargdesc(prov->dtpv_arg,
14271 			    probe->dtpr_id, probe->dtpr_arg, &desc);
14272 		}
14273 
14274 		mutex_exit(&mod_lock);
14275 		mutex_exit(&dtrace_provider_lock);
14276 
14277 		if (copyout(&desc, (void *)arg, sizeof (desc)) != 0)
14278 			return (EFAULT);
14279 
14280 		return (0);
14281 	}
14282 
14283 	case DTRACEIOC_GO: {
14284 		processorid_t cpuid;
14285 		rval = dtrace_state_go(state, &cpuid);
14286 
14287 		if (rval != 0)
14288 			return (rval);
14289 
14290 		if (copyout(&cpuid, (void *)arg, sizeof (cpuid)) != 0)
14291 			return (EFAULT);
14292 
14293 		return (0);
14294 	}
14295 
14296 	case DTRACEIOC_STOP: {
14297 		processorid_t cpuid;
14298 
14299 		mutex_enter(&dtrace_lock);
14300 		rval = dtrace_state_stop(state, &cpuid);
14301 		mutex_exit(&dtrace_lock);
14302 
14303 		if (rval != 0)
14304 			return (rval);
14305 
14306 		if (copyout(&cpuid, (void *)arg, sizeof (cpuid)) != 0)
14307 			return (EFAULT);
14308 
14309 		return (0);
14310 	}
14311 
14312 	case DTRACEIOC_DOFGET: {
14313 		dof_hdr_t hdr, *dof;
14314 		uint64_t len;
14315 
14316 		if (copyin((void *)arg, &hdr, sizeof (hdr)) != 0)
14317 			return (EFAULT);
14318 
14319 		mutex_enter(&dtrace_lock);
14320 		dof = dtrace_dof_create(state);
14321 		mutex_exit(&dtrace_lock);
14322 
14323 		len = MIN(hdr.dofh_loadsz, dof->dofh_loadsz);
14324 		rval = copyout(dof, (void *)arg, len);
14325 		dtrace_dof_destroy(dof);
14326 
14327 		return (rval == 0 ? 0 : EFAULT);
14328 	}
14329 
14330 	case DTRACEIOC_AGGSNAP:
14331 	case DTRACEIOC_BUFSNAP: {
14332 		dtrace_bufdesc_t desc;
14333 		caddr_t cached;
14334 		dtrace_buffer_t *buf;
14335 
14336 		if (copyin((void *)arg, &desc, sizeof (desc)) != 0)
14337 			return (EFAULT);
14338 
14339 		if (desc.dtbd_cpu < 0 || desc.dtbd_cpu >= NCPU)
14340 			return (EINVAL);
14341 
14342 		mutex_enter(&dtrace_lock);
14343 
14344 		if (cmd == DTRACEIOC_BUFSNAP) {
14345 			buf = &state->dts_buffer[desc.dtbd_cpu];
14346 		} else {
14347 			buf = &state->dts_aggbuffer[desc.dtbd_cpu];
14348 		}
14349 
14350 		if (buf->dtb_flags & (DTRACEBUF_RING | DTRACEBUF_FILL)) {
14351 			size_t sz = buf->dtb_offset;
14352 
14353 			if (state->dts_activity != DTRACE_ACTIVITY_STOPPED) {
14354 				mutex_exit(&dtrace_lock);
14355 				return (EBUSY);
14356 			}
14357 
14358 			/*
14359 			 * If this buffer has already been consumed, we're
14360 			 * going to indicate that there's nothing left here
14361 			 * to consume.
14362 			 */
14363 			if (buf->dtb_flags & DTRACEBUF_CONSUMED) {
14364 				mutex_exit(&dtrace_lock);
14365 
14366 				desc.dtbd_size = 0;
14367 				desc.dtbd_drops = 0;
14368 				desc.dtbd_errors = 0;
14369 				desc.dtbd_oldest = 0;
14370 				sz = sizeof (desc);
14371 
14372 				if (copyout(&desc, (void *)arg, sz) != 0)
14373 					return (EFAULT);
14374 
14375 				return (0);
14376 			}
14377 
14378 			/*
14379 			 * If this is a ring buffer that has wrapped, we want
14380 			 * to copy the whole thing out.
14381 			 */
14382 			if (buf->dtb_flags & DTRACEBUF_WRAPPED) {
14383 				dtrace_buffer_polish(buf);
14384 				sz = buf->dtb_size;
14385 			}
14386 
14387 			if (copyout(buf->dtb_tomax, desc.dtbd_data, sz) != 0) {
14388 				mutex_exit(&dtrace_lock);
14389 				return (EFAULT);
14390 			}
14391 
14392 			desc.dtbd_size = sz;
14393 			desc.dtbd_drops = buf->dtb_drops;
14394 			desc.dtbd_errors = buf->dtb_errors;
14395 			desc.dtbd_oldest = buf->dtb_xamot_offset;
14396 
14397 			mutex_exit(&dtrace_lock);
14398 
14399 			if (copyout(&desc, (void *)arg, sizeof (desc)) != 0)
14400 				return (EFAULT);
14401 
14402 			buf->dtb_flags |= DTRACEBUF_CONSUMED;
14403 
14404 			return (0);
14405 		}
14406 
14407 		if (buf->dtb_tomax == NULL) {
14408 			ASSERT(buf->dtb_xamot == NULL);
14409 			mutex_exit(&dtrace_lock);
14410 			return (ENOENT);
14411 		}
14412 
14413 		cached = buf->dtb_tomax;
14414 		ASSERT(!(buf->dtb_flags & DTRACEBUF_NOSWITCH));
14415 
14416 		dtrace_xcall(desc.dtbd_cpu,
14417 		    (dtrace_xcall_t)dtrace_buffer_switch, buf);
14418 
14419 		state->dts_errors += buf->dtb_xamot_errors;
14420 
14421 		/*
14422 		 * If the buffers did not actually switch, then the cross call
14423 		 * did not take place -- presumably because the given CPU is
14424 		 * not in the ready set.  If this is the case, we'll return
14425 		 * ENOENT.
14426 		 */
14427 		if (buf->dtb_tomax == cached) {
14428 			ASSERT(buf->dtb_xamot != cached);
14429 			mutex_exit(&dtrace_lock);
14430 			return (ENOENT);
14431 		}
14432 
14433 		ASSERT(cached == buf->dtb_xamot);
14434 
14435 		/*
14436 		 * We have our snapshot; now copy it out.
14437 		 */
14438 		if (copyout(buf->dtb_xamot, desc.dtbd_data,
14439 		    buf->dtb_xamot_offset) != 0) {
14440 			mutex_exit(&dtrace_lock);
14441 			return (EFAULT);
14442 		}
14443 
14444 		desc.dtbd_size = buf->dtb_xamot_offset;
14445 		desc.dtbd_drops = buf->dtb_xamot_drops;
14446 		desc.dtbd_errors = buf->dtb_xamot_errors;
14447 		desc.dtbd_oldest = 0;
14448 
14449 		mutex_exit(&dtrace_lock);
14450 
14451 		/*
14452 		 * Finally, copy out the buffer description.
14453 		 */
14454 		if (copyout(&desc, (void *)arg, sizeof (desc)) != 0)
14455 			return (EFAULT);
14456 
14457 		return (0);
14458 	}
14459 
14460 	case DTRACEIOC_CONF: {
14461 		dtrace_conf_t conf;
14462 
14463 		bzero(&conf, sizeof (conf));
14464 		conf.dtc_difversion = DIF_VERSION;
14465 		conf.dtc_difintregs = DIF_DIR_NREGS;
14466 		conf.dtc_diftupregs = DIF_DTR_NREGS;
14467 		conf.dtc_ctfmodel = CTF_MODEL_NATIVE;
14468 
14469 		if (copyout(&conf, (void *)arg, sizeof (conf)) != 0)
14470 			return (EFAULT);
14471 
14472 		return (0);
14473 	}
14474 
14475 	case DTRACEIOC_STATUS: {
14476 		dtrace_status_t stat;
14477 		dtrace_dstate_t *dstate;
14478 		int i, j;
14479 		uint64_t nerrs;
14480 
14481 		/*
14482 		 * See the comment in dtrace_state_deadman() for the reason
14483 		 * for setting dts_laststatus to INT64_MAX before setting
14484 		 * it to the correct value.
14485 		 */
14486 		state->dts_laststatus = INT64_MAX;
14487 		dtrace_membar_producer();
14488 		state->dts_laststatus = dtrace_gethrtime();
14489 
14490 		bzero(&stat, sizeof (stat));
14491 
14492 		mutex_enter(&dtrace_lock);
14493 
14494 		if (state->dts_activity == DTRACE_ACTIVITY_INACTIVE) {
14495 			mutex_exit(&dtrace_lock);
14496 			return (ENOENT);
14497 		}
14498 
14499 		if (state->dts_activity == DTRACE_ACTIVITY_DRAINING)
14500 			stat.dtst_exiting = 1;
14501 
14502 		nerrs = state->dts_errors;
14503 		dstate = &state->dts_vstate.dtvs_dynvars;
14504 
14505 		for (i = 0; i < NCPU; i++) {
14506 			dtrace_dstate_percpu_t *dcpu = &dstate->dtds_percpu[i];
14507 
14508 			stat.dtst_dyndrops += dcpu->dtdsc_drops;
14509 			stat.dtst_dyndrops_dirty += dcpu->dtdsc_dirty_drops;
14510 			stat.dtst_dyndrops_rinsing += dcpu->dtdsc_rinsing_drops;
14511 
14512 			if (state->dts_buffer[i].dtb_flags & DTRACEBUF_FULL)
14513 				stat.dtst_filled++;
14514 
14515 			nerrs += state->dts_buffer[i].dtb_errors;
14516 
14517 			for (j = 0; j < state->dts_nspeculations; j++) {
14518 				dtrace_speculation_t *spec;
14519 				dtrace_buffer_t *buf;
14520 
14521 				spec = &state->dts_speculations[j];
14522 				buf = &spec->dtsp_buffer[i];
14523 				stat.dtst_specdrops += buf->dtb_xamot_drops;
14524 			}
14525 		}
14526 
14527 		stat.dtst_specdrops_busy = state->dts_speculations_busy;
14528 		stat.dtst_specdrops_unavail = state->dts_speculations_unavail;
14529 		stat.dtst_stkstroverflows = state->dts_stkstroverflows;
14530 		stat.dtst_dblerrors = state->dts_dblerrors;
14531 		stat.dtst_killed =
14532 		    (state->dts_activity == DTRACE_ACTIVITY_KILLED);
14533 		stat.dtst_errors = nerrs;
14534 
14535 		mutex_exit(&dtrace_lock);
14536 
14537 		if (copyout(&stat, (void *)arg, sizeof (stat)) != 0)
14538 			return (EFAULT);
14539 
14540 		return (0);
14541 	}
14542 
14543 	case DTRACEIOC_FORMAT: {
14544 		dtrace_fmtdesc_t fmt;
14545 		char *str;
14546 		int len;
14547 
14548 		if (copyin((void *)arg, &fmt, sizeof (fmt)) != 0)
14549 			return (EFAULT);
14550 
14551 		mutex_enter(&dtrace_lock);
14552 
14553 		if (fmt.dtfd_format == 0 ||
14554 		    fmt.dtfd_format > state->dts_nformats) {
14555 			mutex_exit(&dtrace_lock);
14556 			return (EINVAL);
14557 		}
14558 
14559 		/*
14560 		 * Format strings are allocated contiguously and they are
14561 		 * never freed; if a format index is less than the number
14562 		 * of formats, we can assert that the format map is non-NULL
14563 		 * and that the format for the specified index is non-NULL.
14564 		 */
14565 		ASSERT(state->dts_formats != NULL);
14566 		str = state->dts_formats[fmt.dtfd_format - 1];
14567 		ASSERT(str != NULL);
14568 
14569 		len = strlen(str) + 1;
14570 
14571 		if (len > fmt.dtfd_length) {
14572 			fmt.dtfd_length = len;
14573 
14574 			if (copyout(&fmt, (void *)arg, sizeof (fmt)) != 0) {
14575 				mutex_exit(&dtrace_lock);
14576 				return (EINVAL);
14577 			}
14578 		} else {
14579 			if (copyout(str, fmt.dtfd_string, len) != 0) {
14580 				mutex_exit(&dtrace_lock);
14581 				return (EINVAL);
14582 			}
14583 		}
14584 
14585 		mutex_exit(&dtrace_lock);
14586 		return (0);
14587 	}
14588 
14589 	default:
14590 		break;
14591 	}
14592 
14593 	return (ENOTTY);
14594 }
14595 
14596 /*ARGSUSED*/
14597 static int
14598 dtrace_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
14599 {
14600 	dtrace_state_t *state;
14601 
14602 	switch (cmd) {
14603 	case DDI_DETACH:
14604 		break;
14605 
14606 	case DDI_SUSPEND:
14607 		return (DDI_SUCCESS);
14608 
14609 	default:
14610 		return (DDI_FAILURE);
14611 	}
14612 
14613 	mutex_enter(&cpu_lock);
14614 	mutex_enter(&dtrace_provider_lock);
14615 	mutex_enter(&dtrace_lock);
14616 
14617 	ASSERT(dtrace_opens == 0);
14618 
14619 	if (dtrace_helpers > 0) {
14620 		mutex_exit(&dtrace_provider_lock);
14621 		mutex_exit(&dtrace_lock);
14622 		mutex_exit(&cpu_lock);
14623 		return (DDI_FAILURE);
14624 	}
14625 
14626 	if (dtrace_unregister((dtrace_provider_id_t)dtrace_provider) != 0) {
14627 		mutex_exit(&dtrace_provider_lock);
14628 		mutex_exit(&dtrace_lock);
14629 		mutex_exit(&cpu_lock);
14630 		return (DDI_FAILURE);
14631 	}
14632 
14633 	dtrace_provider = NULL;
14634 
14635 	if ((state = dtrace_anon_grab()) != NULL) {
14636 		/*
14637 		 * If there were ECBs on this state, the provider should
14638 		 * have not been allowed to detach; assert that there is
14639 		 * none.
14640 		 */
14641 		ASSERT(state->dts_necbs == 0);
14642 		dtrace_state_destroy(state);
14643 
14644 		/*
14645 		 * If we're being detached with anonymous state, we need to
14646 		 * indicate to the kernel debugger that DTrace is now inactive.
14647 		 */
14648 		(void) kdi_dtrace_set(KDI_DTSET_DTRACE_DEACTIVATE);
14649 	}
14650 
14651 	bzero(&dtrace_anon, sizeof (dtrace_anon_t));
14652 	unregister_cpu_setup_func((cpu_setup_func_t *)dtrace_cpu_setup, NULL);
14653 	dtrace_cpu_init = NULL;
14654 	dtrace_helpers_cleanup = NULL;
14655 	dtrace_helpers_fork = NULL;
14656 	dtrace_cpustart_init = NULL;
14657 	dtrace_cpustart_fini = NULL;
14658 	dtrace_debugger_init = NULL;
14659 	dtrace_debugger_fini = NULL;
14660 	dtrace_kreloc_init = NULL;
14661 	dtrace_kreloc_fini = NULL;
14662 	dtrace_modload = NULL;
14663 	dtrace_modunload = NULL;
14664 
14665 	mutex_exit(&cpu_lock);
14666 
14667 	if (dtrace_helptrace_enabled) {
14668 		kmem_free(dtrace_helptrace_buffer, dtrace_helptrace_bufsize);
14669 		dtrace_helptrace_buffer = NULL;
14670 	}
14671 
14672 	kmem_free(dtrace_probes, dtrace_nprobes * sizeof (dtrace_probe_t *));
14673 	dtrace_probes = NULL;
14674 	dtrace_nprobes = 0;
14675 
14676 	dtrace_hash_destroy(dtrace_bymod);
14677 	dtrace_hash_destroy(dtrace_byfunc);
14678 	dtrace_hash_destroy(dtrace_byname);
14679 	dtrace_bymod = NULL;
14680 	dtrace_byfunc = NULL;
14681 	dtrace_byname = NULL;
14682 
14683 	kmem_cache_destroy(dtrace_state_cache);
14684 	vmem_destroy(dtrace_minor);
14685 	vmem_destroy(dtrace_arena);
14686 
14687 	if (dtrace_toxrange != NULL) {
14688 		kmem_free(dtrace_toxrange,
14689 		    dtrace_toxranges_max * sizeof (dtrace_toxrange_t));
14690 		dtrace_toxrange = NULL;
14691 		dtrace_toxranges = 0;
14692 		dtrace_toxranges_max = 0;
14693 	}
14694 
14695 	ddi_remove_minor_node(dtrace_devi, NULL);
14696 	dtrace_devi = NULL;
14697 
14698 	ddi_soft_state_fini(&dtrace_softstate);
14699 
14700 	ASSERT(dtrace_vtime_references == 0);
14701 	ASSERT(dtrace_opens == 0);
14702 	ASSERT(dtrace_retained == NULL);
14703 
14704 	mutex_exit(&dtrace_lock);
14705 	mutex_exit(&dtrace_provider_lock);
14706 
14707 	/*
14708 	 * We don't destroy the task queue until after we have dropped our
14709 	 * locks (taskq_destroy() may block on running tasks).  To prevent
14710 	 * attempting to do work after we have effectively detached but before
14711 	 * the task queue has been destroyed, all tasks dispatched via the
14712 	 * task queue must check that DTrace is still attached before
14713 	 * performing any operation.
14714 	 */
14715 	taskq_destroy(dtrace_taskq);
14716 	dtrace_taskq = NULL;
14717 
14718 	return (DDI_SUCCESS);
14719 }
14720 
14721 /*ARGSUSED*/
14722 static int
14723 dtrace_info(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg, void **result)
14724 {
14725 	int error;
14726 
14727 	switch (infocmd) {
14728 	case DDI_INFO_DEVT2DEVINFO:
14729 		*result = (void *)dtrace_devi;
14730 		error = DDI_SUCCESS;
14731 		break;
14732 	case DDI_INFO_DEVT2INSTANCE:
14733 		*result = (void *)0;
14734 		error = DDI_SUCCESS;
14735 		break;
14736 	default:
14737 		error = DDI_FAILURE;
14738 	}
14739 	return (error);
14740 }
14741 
14742 static struct cb_ops dtrace_cb_ops = {
14743 	dtrace_open,		/* open */
14744 	dtrace_close,		/* close */
14745 	nulldev,		/* strategy */
14746 	nulldev,		/* print */
14747 	nodev,			/* dump */
14748 	nodev,			/* read */
14749 	nodev,			/* write */
14750 	dtrace_ioctl,		/* ioctl */
14751 	nodev,			/* devmap */
14752 	nodev,			/* mmap */
14753 	nodev,			/* segmap */
14754 	nochpoll,		/* poll */
14755 	ddi_prop_op,		/* cb_prop_op */
14756 	0,			/* streamtab  */
14757 	D_NEW | D_MP		/* Driver compatibility flag */
14758 };
14759 
14760 static struct dev_ops dtrace_ops = {
14761 	DEVO_REV,		/* devo_rev */
14762 	0,			/* refcnt */
14763 	dtrace_info,		/* get_dev_info */
14764 	nulldev,		/* identify */
14765 	nulldev,		/* probe */
14766 	dtrace_attach,		/* attach */
14767 	dtrace_detach,		/* detach */
14768 	nodev,			/* reset */
14769 	&dtrace_cb_ops,		/* driver operations */
14770 	NULL,			/* bus operations */
14771 	nodev			/* dev power */
14772 };
14773 
14774 static struct modldrv modldrv = {
14775 	&mod_driverops,		/* module type (this is a pseudo driver) */
14776 	"Dynamic Tracing",	/* name of module */
14777 	&dtrace_ops,		/* driver ops */
14778 };
14779 
14780 static struct modlinkage modlinkage = {
14781 	MODREV_1,
14782 	(void *)&modldrv,
14783 	NULL
14784 };
14785 
14786 int
14787 _init(void)
14788 {
14789 	return (mod_install(&modlinkage));
14790 }
14791 
14792 int
14793 _info(struct modinfo *modinfop)
14794 {
14795 	return (mod_info(&modlinkage, modinfop));
14796 }
14797 
14798 int
14799 _fini(void)
14800 {
14801 	return (mod_remove(&modlinkage));
14802 }
14803