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 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
23 * Use is subject to license terms.
24 */
25/*
26 * Copyright (c) 2012 by Delphix. All rights reserved.
27 * Copyright (c) 2018, Joyent, Inc.
28 */
29
30/*
31 * Modular Debugger (MDB)
32 *
33 * Refer to the white paper "A Modular Debugger for Solaris" for information
34 * on the design, features, and goals of MDB.  See /shared/sac/PSARC/1999/169
35 * for copies of the paper and related documentation.
36 *
37 * This file provides the basic construction and destruction of the debugger's
38 * global state, as well as the main execution loop, mdb_run().  MDB maintains
39 * a stack of execution frames (mdb_frame_t's) that keep track of its current
40 * state, including a stack of input and output buffers, walk and memory
41 * garbage collect lists, and a list of commands (mdb_cmd_t's).  As the
42 * parser consumes input, it fills in a list of commands to execute, and then
43 * invokes mdb_call(), below.  A command consists of a dcmd, telling us
44 * what function to execute, and a list of arguments and other invocation-
45 * specific data.  Each frame may have more than one command, kept on a list,
46 * when multiple commands are separated by | operators.  New frames may be
47 * stacked on old ones by nested calls to mdb_run: this occurs when, for
48 * example, in the middle of processing one input source (such as a file
49 * or the terminal), we invoke a dcmd that in turn calls mdb_eval().  mdb_eval
50 * will construct a new frame whose input source is the string passed to
51 * the eval function, and then execute this frame to completion.
52 */
53
54#include <sys/param.h>
55#include <stropts.h>
56
57#define	_MDB_PRIVATE
58#include <mdb/mdb.h>
59
60#include <mdb/mdb_context.h>
61#include <mdb/mdb_argvec.h>
62#include <mdb/mdb_signal.h>
63#include <mdb/mdb_macalias.h>
64#include <mdb/mdb_module.h>
65#include <mdb/mdb_modapi.h>
66#include <mdb/mdb_string.h>
67#include <mdb/mdb_callb.h>
68#include <mdb/mdb_debug.h>
69#include <mdb/mdb_frame.h>
70#include <mdb/mdb_conf.h>
71#include <mdb/mdb_err.h>
72#include <mdb/mdb_lex.h>
73#include <mdb/mdb_io.h>
74#include <mdb/mdb_ctf.h>
75#ifdef _KMDB
76#include <kmdb/kmdb_module.h>
77#endif
78
79/*
80 * Macro for testing if a dcmd's return status (x) indicates that we should
81 * abort the current loop or pipeline.
82 */
83#define	DCMD_ABORTED(x)	((x) == DCMD_USAGE || (x) == DCMD_ABORT)
84
85extern const mdb_dcmd_t mdb_dcmd_builtins[];
86extern mdb_dis_ctor_f *const mdb_dis_builtins[];
87
88/*
89 * Variable discipline for toggling MDB_FL_PSYM based on the value of the
90 * undocumented '_' variable.  Once adb(1) has been removed from the system,
91 * we should just remove this functionality and always disable PSYM for macros.
92 */
93static uintmax_t
94psym_disc_get(const mdb_var_t *v)
95{
96	int i = (mdb.m_flags & MDB_FL_PSYM) ? 1 : 0;
97	int j = (MDB_NV_VALUE(v) != 0) ? 1 : 0;
98
99	if ((i ^ j) == 0)
100		MDB_NV_VALUE((mdb_var_t *)v) = j ^ 1;
101
102	return (MDB_NV_VALUE(v));
103}
104
105static void
106psym_disc_set(mdb_var_t *v, uintmax_t value)
107{
108	if (value == 0)
109		mdb.m_flags |= MDB_FL_PSYM;
110	else
111		mdb.m_flags &= ~MDB_FL_PSYM;
112
113	MDB_NV_VALUE(v) = value;
114}
115
116/*
117 * Variable discipline for making <1 (most recent offset) behave properly.
118 */
119static uintmax_t
120roff_disc_get(const mdb_var_t *v)
121{
122	return (MDB_NV_VALUE(v));
123}
124
125static void
126roff_disc_set(mdb_var_t *v, uintmax_t value)
127{
128	mdb_nv_set_value(mdb.m_proffset, MDB_NV_VALUE(v));
129	MDB_NV_VALUE(v) = value;
130}
131
132/*
133 * Variable discipline for exporting the representative thread.
134 */
135static uintmax_t
136thr_disc_get(const mdb_var_t *v)
137{
138	mdb_tgt_status_t s;
139
140	if (mdb.m_target != NULL && mdb_tgt_status(mdb.m_target, &s) == 0)
141		return (s.st_tid);
142
143	return (MDB_NV_VALUE(v));
144}
145
146const char **
147mdb_path_alloc(const char *s, size_t *newlen)
148{
149	char *format = mdb_alloc(strlen(s) * 2 + 1, UM_NOSLEEP);
150	const char **path;
151	char *p, *q;
152
153	struct utsname uts;
154	size_t len;
155	int i;
156
157	mdb_arg_t arg_i, arg_m, arg_p, arg_r, arg_t, arg_R, arg_V;
158	mdb_argvec_t argv;
159
160	static const char *empty_path[] = { NULL };
161
162	if (format == NULL)
163		goto nomem;
164
165	while (*s == ':')
166		s++; /* strip leading delimiters */
167
168	if (*s == '\0') {
169		*newlen = 0;
170		return (empty_path);
171	}
172
173	(void) strcpy(format, s);
174	mdb_argvec_create(&argv);
175
176	/*
177	 * %i embedded in path string expands to ISA.
178	 */
179	arg_i.a_type = MDB_TYPE_STRING;
180	if (mdb.m_target != NULL)
181		arg_i.a_un.a_str = mdb_tgt_isa(mdb.m_target);
182	else
183		arg_i.a_un.a_str = mdb_conf_isa();
184
185	/*
186	 * %p embedded in path string expands to the platform name.
187	 */
188	arg_p.a_type = MDB_TYPE_STRING;
189	if (mdb.m_target != NULL)
190		arg_p.a_un.a_str = mdb_tgt_platform(mdb.m_target);
191	else
192		arg_p.a_un.a_str = mdb_conf_platform();
193
194	/*
195	 * %r embedded in path string expands to root directory, or
196	 * to the empty string if root is "/" (to avoid // in paths).
197	 */
198	arg_r.a_type = MDB_TYPE_STRING;
199	arg_r.a_un.a_str = strcmp(mdb.m_root, "/") ? mdb.m_root : "";
200
201	/*
202	 * %t embedded in path string expands to the target name, defaulting to
203	 * kvm; this is so we can find mdb_kb, which is used during bootstrap.
204	 */
205	arg_t.a_type = MDB_TYPE_STRING;
206	arg_t.a_un.a_str = mdb.m_target ? mdb_tgt_name(mdb.m_target) : "kvm";
207
208	/*
209	 * %R and %V expand to uname -r (release) and uname -v (version).
210	 */
211	if (mdb.m_target == NULL || mdb_tgt_uname(mdb.m_target, &uts) < 0)
212		mdb_conf_uname(&uts);
213
214	arg_m.a_type = MDB_TYPE_STRING;
215	arg_m.a_un.a_str = uts.machine;
216
217	arg_R.a_type = MDB_TYPE_STRING;
218	arg_R.a_un.a_str = uts.release;
219
220	arg_V.a_type = MDB_TYPE_STRING;
221	if (mdb.m_flags & MDB_FL_LATEST)
222		arg_V.a_un.a_str = "latest";
223	else
224		arg_V.a_un.a_str = uts.version;
225
226	/*
227	 * In order to expand the buffer, we examine the format string for
228	 * our % tokens and construct an argvec, replacing each % token
229	 * with %s along the way.  If we encounter an unknown token, we
230	 * shift over the remaining format buffer and stick in %%.
231	 */
232	for (q = format; (q = strchr(q, '%')) != NULL; q++) {
233		switch (q[1]) {
234		case 'i':
235			mdb_argvec_append(&argv, &arg_i);
236			*++q = 's';
237			break;
238		case 'm':
239			mdb_argvec_append(&argv, &arg_m);
240			*++q = 's';
241			break;
242		case 'p':
243			mdb_argvec_append(&argv, &arg_p);
244			*++q = 's';
245			break;
246		case 'r':
247			mdb_argvec_append(&argv, &arg_r);
248			*++q = 's';
249			break;
250		case 't':
251			mdb_argvec_append(&argv, &arg_t);
252			*++q = 's';
253			break;
254		case 'R':
255			mdb_argvec_append(&argv, &arg_R);
256			*++q = 's';
257			break;
258		case 'V':
259			mdb_argvec_append(&argv, &arg_V);
260			*++q = 's';
261			break;
262		default:
263			bcopy(q + 1, q + 2, strlen(q));
264			*++q = '%';
265		}
266	}
267
268	/*
269	 * We're now ready to use our printf engine to format the final string.
270	 * Take one lap with a NULL buffer to determine how long the final
271	 * string will be, allocate it, and format it.
272	 */
273	len = mdb_iob_asnprintf(NULL, 0, format, argv.a_data);
274	if ((p = mdb_alloc(len + 1, UM_NOSLEEP)) != NULL)
275		(void) mdb_iob_asnprintf(p, len + 1, format, argv.a_data);
276	else
277		goto nomem;
278
279	mdb_argvec_zero(&argv);
280	mdb_argvec_destroy(&argv);
281
282	mdb_free(format, strlen(s) * 2 + 1);
283	format = NULL;
284
285	/*
286	 * Compress the string to exclude any leading delimiters.
287	 */
288	for (q = p; *q == ':'; q++)
289		continue;
290	if (q != p)
291		bcopy(q, p, strlen(q) + 1);
292
293	/*
294	 * Count up the number of delimited elements.  A sequence of
295	 * consecutive delimiters is only counted once.
296	 */
297	for (i = 1, q = p; (q = strchr(q, ':')) != NULL; i++) {
298		while (*q == ':')
299			q++;
300	}
301
302	if ((path = mdb_alloc(sizeof (char *) * (i + 1), UM_NOSLEEP)) == NULL) {
303		mdb_free(p, len + 1);
304		goto nomem;
305	}
306
307	for (i = 0, q = strtok(p, ":"); q != NULL; q = strtok(NULL, ":"))
308		path[i++] = q;
309
310	path[i] = NULL;
311	*newlen = len + 1;
312	return (path);
313
314nomem:
315	warn("failed to allocate memory for path");
316	if (format != NULL)
317		mdb_free(format, strlen(s) * 2 + 1);
318	*newlen = 0;
319	return (empty_path);
320}
321
322const char **
323mdb_path_dup(const char *path[], size_t pathlen, size_t *npathlenp)
324{
325	char **npath;
326	int i, j;
327
328	for (i = 0; path[i] != NULL; i++)
329		continue; /* count the path elements */
330
331	npath = mdb_zalloc(sizeof (char *) * (i + 1), UM_SLEEP);
332	if (pathlen > 0) {
333		npath[0] = mdb_alloc(pathlen, UM_SLEEP);
334		bcopy(path[0], npath[0], pathlen);
335	}
336
337	for (j = 1; j < i; j++)
338		npath[j] = npath[0] + (path[j] - path[0]);
339	npath[i] = NULL;
340
341	*npathlenp = pathlen;
342	return ((const char **)npath);
343}
344
345void
346mdb_path_free(const char *path[], size_t pathlen)
347{
348	int i;
349
350	for (i = 0; path[i] != NULL; i++)
351		continue; /* count the path elements */
352
353	if (i > 0) {
354		mdb_free((void *)path[0], pathlen);
355		mdb_free(path, sizeof (char *) * (i + 1));
356	}
357}
358
359/*
360 * Convert path string "s" to canonical form, expanding any %o tokens that are
361 * found within the path.  The old path string is specified by "path", a buffer
362 * of size MAXPATHLEN which is then overwritten with the new path string.
363 */
364static const char *
365path_canon(char *path, const char *s)
366{
367	char *p = path;
368	char *q = p + MAXPATHLEN - 1;
369
370	char old[MAXPATHLEN];
371	char c;
372
373	(void) strcpy(old, p);
374	*q = '\0';
375
376	while (p < q && (c = *s++) != '\0') {
377		if (c == '%') {
378			if ((c = *s++) == 'o') {
379				(void) strncpy(p, old, (size_t)(q - p));
380				p += strlen(p);
381			} else {
382				*p++ = '%';
383				if (p < q && c != '\0')
384					*p++ = c;
385				else
386					break;
387			}
388		} else
389			*p++ = c;
390	}
391
392	*p = '\0';
393	return (path);
394}
395
396void
397mdb_set_ipath(const char *path)
398{
399	if (mdb.m_ipath != NULL)
400		mdb_path_free(mdb.m_ipath, mdb.m_ipathlen);
401
402	path = path_canon(mdb.m_ipathstr, path);
403	mdb.m_ipath = mdb_path_alloc(path, &mdb.m_ipathlen);
404}
405
406void
407mdb_set_lpath(const char *path)
408{
409	if (mdb.m_lpath != NULL)
410		mdb_path_free(mdb.m_lpath, mdb.m_lpathlen);
411
412	path = path_canon(mdb.m_lpathstr, path);
413	mdb.m_lpath = mdb_path_alloc(path, &mdb.m_lpathlen);
414
415#ifdef _KMDB
416	kmdb_module_path_set(mdb.m_lpath, mdb.m_lpathlen);
417#endif
418}
419
420static void
421prompt_update(void)
422{
423	(void) mdb_snprintf(mdb.m_prompt, sizeof (mdb.m_prompt),
424	    mdb.m_promptraw);
425	mdb.m_promptlen = strlen(mdb.m_prompt);
426}
427
428const char *
429mdb_get_prompt(void)
430{
431	if (mdb.m_promptlen == 0)
432		return (NULL);
433	else
434		return (mdb.m_prompt);
435}
436
437int
438mdb_set_prompt(const char *p)
439{
440	size_t len = strlen(p);
441
442	if (len > MDB_PROMPTLEN) {
443		warn("prompt may not exceed %d characters\n", MDB_PROMPTLEN);
444		return (0);
445	}
446
447	(void) strcpy(mdb.m_promptraw, p);
448	prompt_update();
449	return (1);
450}
451
452static mdb_frame_t frame0;
453
454void
455mdb_create(const char *execname, const char *arg0)
456{
457	static const mdb_nv_disc_t psym_disc = { psym_disc_set, psym_disc_get };
458	static const mdb_nv_disc_t roff_disc = { roff_disc_set, roff_disc_get };
459	static const mdb_nv_disc_t thr_disc = { NULL, thr_disc_get };
460
461	static char rootdir[MAXPATHLEN];
462
463	const mdb_dcmd_t *dcp;
464	int i;
465
466	bzero(&mdb, sizeof (mdb_t));
467
468	mdb.m_flags = MDB_FL_PSYM | MDB_FL_PAGER | MDB_FL_BPTNOSYMSTOP |
469	    MDB_FL_READBACK;
470	mdb.m_radix = MDB_DEF_RADIX;
471	mdb.m_nargs = MDB_DEF_NARGS;
472	mdb.m_histlen = MDB_DEF_HISTLEN;
473	mdb.m_armemlim = MDB_DEF_ARRMEM;
474	mdb.m_arstrlim = MDB_DEF_ARRSTR;
475
476	mdb.m_pname = strbasename(arg0);
477	if (strcmp(mdb.m_pname, "adb") == 0) {
478		mdb.m_flags |= MDB_FL_NOMODS | MDB_FL_ADB | MDB_FL_REPLAST;
479		mdb.m_flags &= ~MDB_FL_PAGER;
480	}
481
482	mdb.m_ipathstr = mdb_zalloc(MAXPATHLEN, UM_SLEEP);
483	mdb.m_lpathstr = mdb_zalloc(MAXPATHLEN, UM_SLEEP);
484
485	(void) strncpy(rootdir, execname, sizeof (rootdir));
486	rootdir[sizeof (rootdir) - 1] = '\0';
487	(void) strdirname(rootdir);
488
489	if (strcmp(strbasename(rootdir), "sparcv9") == 0 ||
490	    strcmp(strbasename(rootdir), "sparcv7") == 0 ||
491	    strcmp(strbasename(rootdir), "amd64") == 0 ||
492	    strcmp(strbasename(rootdir), "i86") == 0)
493		(void) strdirname(rootdir);
494
495	if (strcmp(strbasename(rootdir), "bin") == 0) {
496		(void) strdirname(rootdir);
497		if (strcmp(strbasename(rootdir), "usr") == 0)
498			(void) strdirname(rootdir);
499	} else
500		(void) strcpy(rootdir, "/");
501
502	mdb.m_root = rootdir;
503
504	mdb.m_rminfo.mi_dvers = MDB_API_VERSION;
505	mdb.m_rminfo.mi_dcmds = mdb_dcmd_builtins;
506	mdb.m_rminfo.mi_walkers = NULL;
507
508	(void) mdb_nv_create(&mdb.m_rmod.mod_walkers, UM_SLEEP);
509	(void) mdb_nv_create(&mdb.m_rmod.mod_dcmds, UM_SLEEP);
510
511	mdb.m_rmod.mod_name = mdb.m_pname;
512	mdb.m_rmod.mod_info = &mdb.m_rminfo;
513
514	(void) mdb_nv_create(&mdb.m_disasms, UM_SLEEP);
515	(void) mdb_nv_create(&mdb.m_modules, UM_SLEEP);
516	(void) mdb_nv_create(&mdb.m_dcmds, UM_SLEEP);
517	(void) mdb_nv_create(&mdb.m_walkers, UM_SLEEP);
518	(void) mdb_nv_create(&mdb.m_nv, UM_SLEEP);
519
520	mdb.m_dot = mdb_nv_insert(&mdb.m_nv, ".", NULL, 0, MDB_NV_PERSIST);
521	mdb.m_rvalue = mdb_nv_insert(&mdb.m_nv, "0", NULL, 0, MDB_NV_PERSIST);
522
523	mdb.m_roffset =
524	    mdb_nv_insert(&mdb.m_nv, "1", &roff_disc, 0, MDB_NV_PERSIST);
525
526	mdb.m_proffset = mdb_nv_insert(&mdb.m_nv, "2", NULL, 0, MDB_NV_PERSIST);
527	mdb.m_rcount = mdb_nv_insert(&mdb.m_nv, "9", NULL, 0, MDB_NV_PERSIST);
528
529	(void) mdb_nv_insert(&mdb.m_nv, "b", NULL, 0, MDB_NV_PERSIST);
530	(void) mdb_nv_insert(&mdb.m_nv, "d", NULL, 0, MDB_NV_PERSIST);
531	(void) mdb_nv_insert(&mdb.m_nv, "e", NULL, 0, MDB_NV_PERSIST);
532	(void) mdb_nv_insert(&mdb.m_nv, "m", NULL, 0, MDB_NV_PERSIST);
533	(void) mdb_nv_insert(&mdb.m_nv, "t", NULL, 0, MDB_NV_PERSIST);
534	(void) mdb_nv_insert(&mdb.m_nv, "_", &psym_disc, 0, MDB_NV_PERSIST);
535	(void) mdb_nv_insert(&mdb.m_nv, "hits", NULL, 0, MDB_NV_PERSIST);
536
537	(void) mdb_nv_insert(&mdb.m_nv, "thread", &thr_disc, 0,
538	    MDB_NV_PERSIST | MDB_NV_RDONLY);
539
540	mdb.m_prsym = mdb_gelf_symtab_create_mutable();
541
542	(void) mdb_nv_insert(&mdb.m_modules, mdb.m_pname, NULL,
543	    (uintptr_t)&mdb.m_rmod, MDB_NV_RDONLY);
544
545	for (dcp = &mdb_dcmd_builtins[0]; dcp->dc_name != NULL; dcp++)
546		(void) mdb_module_add_dcmd(&mdb.m_rmod, dcp, 0);
547
548	for (i = 0; mdb_dis_builtins[i] != NULL; i++)
549		(void) mdb_dis_create(mdb_dis_builtins[i]);
550
551	mdb_macalias_create();
552
553	mdb_create_builtin_tgts();
554
555	(void) mdb_callb_add(NULL, MDB_CALLB_PROMPT, (mdb_callb_f)prompt_update,
556	    NULL);
557
558	/*
559	 * The call to ctf_create that this does can in fact fail, but that's
560	 * okay. All of the ctf functions that might use the synthetic types
561	 * make sure that this is safe.
562	 */
563	(void) mdb_ctf_synthetics_init();
564
565#ifdef _KMDB
566	(void) mdb_nv_create(&mdb.m_dmodctl, UM_SLEEP);
567#endif
568	mdb_lex_state_create(&frame0);
569
570	mdb_list_append(&mdb.m_flist, &frame0);
571	mdb.m_frame = &frame0;
572}
573
574void
575mdb_destroy(void)
576{
577	const mdb_dcmd_t *dcp;
578	mdb_var_t *v;
579	int unload_mode = MDB_MOD_SILENT;
580
581#ifdef _KMDB
582	unload_mode |= MDB_MOD_DEFER;
583#endif
584
585	mdb_intr_disable();
586
587	mdb_ctf_synthetics_fini();
588
589	mdb_macalias_destroy();
590
591	/*
592	 * Some targets use modules during ->t_destroy, so do it first.
593	 */
594	if (mdb.m_target != NULL)
595		(void) mdb_tgt_destroy(mdb.m_target);
596
597	/*
598	 * Unload modules _before_ destroying the disassemblers since a
599	 * module that installs a disassembler should try to clean up after
600	 * itself.
601	 */
602	mdb_module_unload_all(unload_mode);
603
604	mdb_nv_rewind(&mdb.m_disasms);
605	while ((v = mdb_nv_advance(&mdb.m_disasms)) != NULL)
606		mdb_dis_destroy(mdb_nv_get_cookie(v));
607
608	mdb_callb_remove_all();
609
610	if (mdb.m_defdisasm != NULL)
611		strfree(mdb.m_defdisasm);
612
613	if (mdb.m_prsym != NULL)
614		mdb_gelf_symtab_destroy(mdb.m_prsym);
615
616	for (dcp = &mdb_dcmd_builtins[0]; dcp->dc_name != NULL; dcp++)
617		(void) mdb_module_remove_dcmd(&mdb.m_rmod, dcp->dc_name);
618
619	mdb_nv_destroy(&mdb.m_nv);
620	mdb_nv_destroy(&mdb.m_walkers);
621	mdb_nv_destroy(&mdb.m_dcmds);
622	mdb_nv_destroy(&mdb.m_modules);
623	mdb_nv_destroy(&mdb.m_disasms);
624
625	mdb_free(mdb.m_ipathstr, MAXPATHLEN);
626	mdb_free(mdb.m_lpathstr, MAXPATHLEN);
627
628	if (mdb.m_ipath != NULL)
629		mdb_path_free(mdb.m_ipath, mdb.m_ipathlen);
630
631	if (mdb.m_lpath != NULL)
632		mdb_path_free(mdb.m_lpath, mdb.m_lpathlen);
633
634	if (mdb.m_in != NULL)
635		mdb_iob_destroy(mdb.m_in);
636
637	mdb_iob_destroy(mdb.m_out);
638	mdb.m_out = NULL;
639	mdb_iob_destroy(mdb.m_err);
640	mdb.m_err = NULL;
641
642	if (mdb.m_log != NULL)
643		mdb_io_rele(mdb.m_log);
644
645	mdb_lex_state_destroy(&frame0);
646}
647
648/*
649 * The real main loop of the debugger: create a new execution frame on the
650 * debugger stack, and while we have input available, call into the parser.
651 */
652int
653mdb_run(void)
654{
655	volatile int err;
656	mdb_frame_t f;
657
658	mdb_intr_disable();
659	mdb_frame_push(&f);
660
661	/*
662	 * This is a fresh mdb context, so ignore any pipe command we may have
663	 * inherited from the previous frame.
664	 */
665	f.f_pcmd = NULL;
666
667	if ((err = setjmp(f.f_pcb)) != 0) {
668		int pop = (mdb.m_in != NULL &&
669		    (mdb_iob_isapipe(mdb.m_in) || mdb_iob_isastr(mdb.m_in)));
670		int fromcmd = (f.f_cp != NULL);
671
672		mdb_dprintf(MDB_DBG_DSTK, "frame <%u> caught event %s\n",
673		    f.f_id, mdb_err2str(err));
674
675		/*
676		 * If a syntax error or other failure has occurred, pop all
677		 * input buffers pushed by commands executed in this frame.
678		 */
679		while (mdb_iob_stack_size(&f.f_istk) != 0) {
680			if (mdb.m_in != NULL)
681				mdb_iob_destroy(mdb.m_in);
682			mdb.m_in = mdb_iob_stack_pop(&f.f_istk);
683			yylineno = mdb_iob_lineno(mdb.m_in);
684		}
685
686		/*
687		 * Reset standard output and the current frame to a known,
688		 * clean state, so we can continue execution.
689		 */
690		mdb_iob_margin(mdb.m_out, MDB_IOB_DEFMARGIN);
691		mdb_iob_clrflags(mdb.m_out, MDB_IOB_INDENT);
692		mdb_iob_discard(mdb.m_out);
693		mdb_frame_reset(&f);
694
695		/*
696		 * If there was an error writing to output, display a warning
697		 * message if this is the topmost frame.
698		 */
699		if (err == MDB_ERR_OUTPUT && mdb.m_depth == 1 && errno != EPIPE)
700			mdb_warn("write failed");
701
702		/*
703		 * If an interrupt or quit signal is reported, we may have been
704		 * in the middle of typing or processing the command line:
705		 * print a newline and discard everything in the parser's iob.
706		 * Note that we do this after m_out has been reset, otherwise
707		 * we could trigger a pipe context switch or cause a write
708		 * to a broken pipe (in the case of a shell command) when
709		 * writing the newline.
710		 */
711		if (err == MDB_ERR_SIGINT || err == MDB_ERR_QUIT) {
712			mdb_iob_nl(mdb.m_out);
713			yydiscard();
714		}
715
716		/*
717		 * If we quit or abort using the output pager, reset the
718		 * line count on standard output back to zero.
719		 */
720		if (err == MDB_ERR_PAGER || MDB_ERR_IS_FATAL(err))
721			mdb_iob_clearlines(mdb.m_out);
722
723		/*
724		 * If the user requested the debugger quit or abort back to
725		 * the top, or if standard input is a pipe or mdb_eval("..."),
726		 * then propagate the error up the debugger stack.
727		 */
728		if (MDB_ERR_IS_FATAL(err) || pop != 0 ||
729		    (err == MDB_ERR_PAGER && mdb.m_fmark != &f) ||
730		    (err == MDB_ERR_NOMEM && !fromcmd)) {
731			mdb_frame_pop(&f, err);
732			return (err);
733		}
734
735		/*
736		 * If we've returned here from a context where signals were
737		 * blocked (e.g. a signal handler), we can now unblock them.
738		 */
739		if (err == MDB_ERR_SIGINT)
740			(void) mdb_signal_unblock(SIGINT);
741	} else
742		mdb_intr_enable();
743
744	for (;;) {
745		while (mdb.m_in != NULL && (mdb_iob_getflags(mdb.m_in) &
746		    (MDB_IOB_ERR | MDB_IOB_EOF)) == 0) {
747			if (mdb.m_depth == 1 &&
748			    mdb_iob_stack_size(&f.f_istk) == 0) {
749				mdb_iob_clearlines(mdb.m_out);
750				mdb_tgt_periodic(mdb.m_target);
751			}
752
753			(void) yyparse();
754		}
755
756		if (mdb.m_in != NULL) {
757			if (mdb_iob_err(mdb.m_in)) {
758				warn("error reading input stream %s\n",
759				    mdb_iob_name(mdb.m_in));
760			}
761			mdb_iob_destroy(mdb.m_in);
762			mdb.m_in = NULL;
763		}
764
765		if (mdb_iob_stack_size(&f.f_istk) == 0)
766			break; /* return when we're out of input */
767
768		mdb.m_in = mdb_iob_stack_pop(&f.f_istk);
769		yylineno = mdb_iob_lineno(mdb.m_in);
770	}
771
772	mdb_frame_pop(&f, 0);
773
774	/*
775	 * The value of '.' is a per-frame attribute, to preserve it properly
776	 * when switching frames.  But in the case of calling mdb_run()
777	 * explicitly (such as through mdb_eval), we want to propagate the value
778	 * of '.' to the parent.
779	 */
780	mdb_nv_set_value(mdb.m_dot, f.f_dot);
781
782	return (0);
783}
784
785/*
786 * The read-side of the pipe executes this service routine.  We simply call
787 * mdb_run to create a new frame on the execution stack and run the MDB parser,
788 * and then propagate any error code back to the previous frame.
789 */
790static int
791runsvc(void)
792{
793	int err = mdb_run();
794
795	if (err != 0) {
796		mdb_dprintf(MDB_DBG_DSTK, "forwarding error %s from pipeline\n",
797		    mdb_err2str(err));
798		longjmp(mdb.m_frame->f_pcb, err);
799	}
800
801	return (err);
802}
803
804/*
805 * Read-side pipe service routine: if we longjmp here, just return to the read
806 * routine because now we have more data to consume.  Otherwise:
807 * (1) if ctx_data is non-NULL, longjmp to the write-side to produce more data;
808 * (2) if wriob is NULL, there is no writer but this is the first read, so we
809 *     can just execute mdb_run() to completion on the current stack;
810 * (3) if (1) and (2) are false, then there is a writer and this is the first
811 *     read, so create a co-routine context to execute mdb_run().
812 */
813/*ARGSUSED*/
814static void
815rdsvc(mdb_iob_t *rdiob, mdb_iob_t *wriob, mdb_iob_ctx_t *ctx)
816{
817	if (setjmp(ctx->ctx_rpcb) == 0) {
818		/*
819		 * Save the current standard input into the pipe context, and
820		 * reset m_in to point to the pipe.  We will restore it on
821		 * the way back in wrsvc() below.
822		 */
823		ctx->ctx_iob = mdb.m_in;
824		mdb.m_in = rdiob;
825
826		ctx->ctx_rptr = mdb.m_frame;
827		if (ctx->ctx_wptr != NULL)
828			mdb_frame_switch(ctx->ctx_wptr);
829
830		if (ctx->ctx_data != NULL)
831			longjmp(ctx->ctx_wpcb, 1);
832		else if (wriob == NULL)
833			(void) runsvc();
834		else if ((ctx->ctx_data = mdb_context_create(runsvc)) != NULL)
835			mdb_context_switch(ctx->ctx_data);
836		else
837			mdb_warn("failed to create pipe context");
838	}
839}
840
841/*
842 * Write-side pipe service routine: if we longjmp here, just return to the
843 * write routine because now we have free space in the pipe buffer for writing;
844 * otherwise longjmp to the read-side to consume data and create space for us.
845 */
846/*ARGSUSED*/
847static void
848wrsvc(mdb_iob_t *rdiob, mdb_iob_t *wriob, mdb_iob_ctx_t *ctx)
849{
850	if (setjmp(ctx->ctx_wpcb) == 0) {
851		ctx->ctx_wptr = mdb.m_frame;
852		if (ctx->ctx_rptr != NULL)
853			mdb_frame_switch(ctx->ctx_rptr);
854
855		mdb.m_in = ctx->ctx_iob;
856		longjmp(ctx->ctx_rpcb, 1);
857	}
858}
859
860/*
861 * Call the current frame's mdb command.  This entry point is used by the
862 * MDB parser to actually execute a command once it has successfully parsed
863 * a line of input.  The command is waiting for us in the current frame.
864 * We loop through each command on the list, executing its dcmd with the
865 * appropriate argument.  If the command has a successor, we know it had
866 * a | operator after it, and so we need to create a pipe and replace
867 * stdout with the pipe's output buffer.
868 */
869int
870mdb_call(uintmax_t addr, uintmax_t count, uint_t flags)
871{
872	mdb_frame_t *fp = mdb.m_frame;
873	mdb_cmd_t *cp, *ncp;
874	mdb_iob_t *iobs[2];
875	int status, err = 0;
876	jmp_buf pcb;
877
878	if (mdb_iob_isapipe(mdb.m_in))
879		yyerror("syntax error");
880
881	mdb_intr_disable();
882	fp->f_cp = mdb_list_next(&fp->f_cmds);
883
884	if (flags & DCMD_LOOP)
885		flags |= DCMD_LOOPFIRST; /* set LOOPFIRST if this is a loop */
886
887	for (cp = mdb_list_next(&fp->f_cmds); cp; cp = mdb_list_next(cp)) {
888		if (mdb_list_next(cp) != NULL) {
889			mdb_iob_pipe(iobs, rdsvc, wrsvc);
890
891			mdb_iob_stack_push(&fp->f_istk, mdb.m_in, yylineno);
892			mdb.m_in = iobs[MDB_IOB_RDIOB];
893
894			mdb_iob_stack_push(&fp->f_ostk, mdb.m_out, 0);
895			mdb.m_out = iobs[MDB_IOB_WRIOB];
896
897			ncp = mdb_list_next(cp);
898			mdb_vcb_inherit(cp, ncp);
899
900			bcopy(fp->f_pcb, pcb, sizeof (jmp_buf));
901			ASSERT(fp->f_pcmd == NULL);
902			fp->f_pcmd = ncp;
903
904			mdb_frame_set_pipe(fp);
905
906			if ((err = setjmp(fp->f_pcb)) == 0) {
907				status = mdb_call_idcmd(cp->c_dcmd, addr, count,
908				    flags | DCMD_PIPE_OUT, &cp->c_argv,
909				    &cp->c_addrv, cp->c_vcbs);
910
911				mdb.m_lastret = status;
912
913				ASSERT(mdb.m_in == iobs[MDB_IOB_RDIOB]);
914				ASSERT(mdb.m_out == iobs[MDB_IOB_WRIOB]);
915			} else {
916				mdb_dprintf(MDB_DBG_DSTK, "frame <%u> caught "
917				    "error %s from pipeline\n", fp->f_id,
918				    mdb_err2str(err));
919			}
920
921			if (err != 0 || DCMD_ABORTED(status)) {
922				mdb_iob_setflags(mdb.m_in, MDB_IOB_ERR);
923				mdb_iob_setflags(mdb.m_out, MDB_IOB_ERR);
924			} else {
925				mdb_iob_flush(mdb.m_out);
926				(void) mdb_iob_ctl(mdb.m_out, I_FLUSH,
927				    (void *)FLUSHW);
928			}
929
930			mdb_frame_clear_pipe(fp);
931
932			mdb_iob_destroy(mdb.m_out);
933			mdb.m_out = mdb_iob_stack_pop(&fp->f_ostk);
934
935			if (mdb.m_in != NULL)
936				mdb_iob_destroy(mdb.m_in);
937
938			mdb.m_in = mdb_iob_stack_pop(&fp->f_istk);
939			yylineno = mdb_iob_lineno(mdb.m_in);
940
941			fp->f_pcmd = NULL;
942			bcopy(pcb, fp->f_pcb, sizeof (jmp_buf));
943
944			if (MDB_ERR_IS_FATAL(err))
945				longjmp(fp->f_pcb, err);
946
947			if (err != 0 || DCMD_ABORTED(status) ||
948			    mdb_addrvec_length(&ncp->c_addrv) == 0)
949				break;
950
951			addr = mdb_nv_get_value(mdb.m_dot);
952			count = 1;
953			flags = 0;
954
955		} else {
956			mdb_intr_enable();
957			mdb.m_lastret = mdb_call_idcmd(cp->c_dcmd, addr, count,
958			    flags, &cp->c_argv, &cp->c_addrv, cp->c_vcbs);
959			mdb_intr_disable();
960		}
961
962		fp->f_cp = mdb_list_next(cp);
963		mdb_cmd_reset(cp);
964	}
965
966	/*
967	 * If our last-command list is non-empty, destroy it.  Then copy the
968	 * current frame's cmd list to the m_lastc list and reset the frame.
969	 */
970	while ((cp = mdb_list_next(&mdb.m_lastc)) != NULL) {
971		mdb_list_delete(&mdb.m_lastc, cp);
972		mdb_cmd_destroy(cp);
973	}
974
975	mdb_list_move(&fp->f_cmds, &mdb.m_lastc);
976	mdb_frame_reset(fp);
977	mdb_intr_enable();
978	return (err == 0);
979}
980
981uintmax_t
982mdb_dot_incr(const char *op)
983{
984	uintmax_t odot, ndot;
985
986	odot = mdb_nv_get_value(mdb.m_dot);
987	ndot = odot + mdb.m_incr;
988
989	if ((odot ^ ndot) & 0x8000000000000000ull)
990		yyerror("'%s' would cause '.' to overflow\n", op);
991
992	return (ndot);
993}
994
995uintmax_t
996mdb_dot_decr(const char *op)
997{
998	uintmax_t odot, ndot;
999
1000	odot = mdb_nv_get_value(mdb.m_dot);
1001	ndot = odot - mdb.m_incr;
1002
1003	if (ndot > odot)
1004		yyerror("'%s' would cause '.' to underflow\n", op);
1005
1006	return (ndot);
1007}
1008
1009mdb_iwalker_t *
1010mdb_walker_lookup(const char *s)
1011{
1012	const char *p = strchr(s, '`');
1013	mdb_var_t *v;
1014
1015	if (p != NULL) {
1016		size_t nbytes = MIN((size_t)(p - s), MDB_NV_NAMELEN - 1);
1017		char mname[MDB_NV_NAMELEN];
1018		mdb_module_t *mod;
1019
1020		(void) strncpy(mname, s, nbytes);
1021		mname[nbytes] = '\0';
1022
1023		if ((v = mdb_nv_lookup(&mdb.m_modules, mname)) == NULL) {
1024			(void) set_errno(EMDB_NOMOD);
1025			return (NULL);
1026		}
1027
1028		mod = mdb_nv_get_cookie(v);
1029
1030		if ((v = mdb_nv_lookup(&mod->mod_walkers, ++p)) != NULL)
1031			return (mdb_nv_get_cookie(v));
1032
1033	} else if ((v = mdb_nv_lookup(&mdb.m_walkers, s)) != NULL)
1034		return (mdb_nv_get_cookie(mdb_nv_get_cookie(v)));
1035
1036	(void) set_errno(EMDB_NOWALK);
1037	return (NULL);
1038}
1039
1040mdb_idcmd_t *
1041mdb_dcmd_lookup(const char *s)
1042{
1043	const char *p = strchr(s, '`');
1044	mdb_var_t *v;
1045
1046	if (p != NULL) {
1047		size_t nbytes = MIN((size_t)(p - s), MDB_NV_NAMELEN - 1);
1048		char mname[MDB_NV_NAMELEN];
1049		mdb_module_t *mod;
1050
1051		(void) strncpy(mname, s, nbytes);
1052		mname[nbytes] = '\0';
1053
1054		if ((v = mdb_nv_lookup(&mdb.m_modules, mname)) == NULL) {
1055			(void) set_errno(EMDB_NOMOD);
1056			return (NULL);
1057		}
1058
1059		mod = mdb_nv_get_cookie(v);
1060
1061		if ((v = mdb_nv_lookup(&mod->mod_dcmds, ++p)) != NULL)
1062			return (mdb_nv_get_cookie(v));
1063
1064	} else if ((v = mdb_nv_lookup(&mdb.m_dcmds, s)) != NULL)
1065		return (mdb_nv_get_cookie(mdb_nv_get_cookie(v)));
1066
1067	(void) set_errno(EMDB_NODCMD);
1068	return (NULL);
1069}
1070
1071void
1072mdb_dcmd_usage(const mdb_idcmd_t *idcp, mdb_iob_t *iob)
1073{
1074	const char *prefix = "", *usage = "";
1075	char name0 = idcp->idc_name[0];
1076
1077	if (idcp->idc_usage != NULL) {
1078		if (idcp->idc_usage[0] == ':') {
1079			if (name0 != ':' && name0 != '$')
1080				prefix = "address::";
1081			else
1082				prefix = "address";
1083			usage = &idcp->idc_usage[1];
1084
1085		} else if (idcp->idc_usage[0] == '?') {
1086			if (name0 != ':' && name0 != '$')
1087				prefix = "[address]::";
1088			else
1089				prefix = "[address]";
1090			usage = &idcp->idc_usage[1];
1091
1092		} else
1093			usage = idcp->idc_usage;
1094	}
1095
1096	mdb_iob_printf(iob, "Usage: %s%s %s\n", prefix, idcp->idc_name, usage);
1097
1098	if (idcp->idc_help != NULL) {
1099		mdb_iob_printf(iob, "%s: try '::help %s' for more "
1100		    "information\n", mdb.m_pname, idcp->idc_name);
1101	}
1102}
1103
1104static mdb_idcmd_t *
1105dcmd_ndef(const mdb_idcmd_t *idcp)
1106{
1107	mdb_var_t *v = mdb_nv_get_ndef(idcp->idc_var);
1108
1109	if (v != NULL)
1110		return (mdb_nv_get_cookie(mdb_nv_get_cookie(v)));
1111
1112	return (NULL);
1113}
1114
1115static int
1116dcmd_invoke(mdb_idcmd_t *idcp, uintptr_t addr, uint_t flags,
1117    int argc, const mdb_arg_t *argv, const mdb_vcb_t *vcbs)
1118{
1119	int status;
1120
1121	mdb_dprintf(MDB_DBG_DCMD, "dcmd %s`%s dot = %lr incr = %llr\n",
1122	    idcp->idc_modp->mod_name, idcp->idc_name, addr, mdb.m_incr);
1123
1124	if ((status = idcp->idc_funcp(addr, flags, argc, argv)) == DCMD_USAGE) {
1125		mdb_dcmd_usage(idcp, mdb.m_err);
1126		goto done;
1127	}
1128
1129	while (status == DCMD_NEXT && (idcp = dcmd_ndef(idcp)) != NULL)
1130		status = idcp->idc_funcp(addr, flags, argc, argv);
1131
1132	if (status == DCMD_USAGE)
1133		mdb_dcmd_usage(idcp, mdb.m_err);
1134
1135	if (status == DCMD_NEXT)
1136		status = DCMD_OK;
1137done:
1138	/*
1139	 * If standard output is a pipe and there are vcbs active, we need to
1140	 * flush standard out and the write-side of the pipe.  The reasons for
1141	 * this are explained in more detail in mdb_vcb.c.
1142	 */
1143	if ((flags & DCMD_PIPE_OUT) && (vcbs != NULL)) {
1144		mdb_iob_flush(mdb.m_out);
1145		(void) mdb_iob_ctl(mdb.m_out, I_FLUSH, (void *)FLUSHW);
1146	}
1147
1148	return (status);
1149}
1150
1151void
1152mdb_call_tab(mdb_idcmd_t *idcp, mdb_tab_cookie_t *mcp, uint_t flags,
1153    uintmax_t argc, mdb_arg_t *argv)
1154{
1155	if (idcp->idc_tabp == NULL)
1156		return;
1157
1158	(void) idcp->idc_tabp(mcp, flags, argc, argv);
1159}
1160
1161/*
1162 * Call an internal dcmd directly: this code is used by module API functions
1163 * that need to execute dcmds, and by mdb_call() above.
1164 */
1165int
1166mdb_call_idcmd(mdb_idcmd_t *idcp, uintmax_t addr, uintmax_t count,
1167    uint_t flags, mdb_argvec_t *avp, mdb_addrvec_t *adp, mdb_vcb_t *vcbs)
1168{
1169	int is_exec = (strcmp(idcp->idc_name, "$<") == 0);
1170	mdb_arg_t *argv;
1171	int argc;
1172	uintmax_t i;
1173	int status;
1174
1175	/*
1176	 * Update the values of dot and the most recent address and count
1177	 * to the values of our input parameters.
1178	 */
1179	mdb_nv_set_value(mdb.m_dot, addr);
1180	mdb.m_raddr = addr;
1181	mdb.m_dcount = count;
1182
1183	/*
1184	 * Here the adb(1) man page lies: '9' is only set to count
1185	 * when the command is $<, not when it's $<<.
1186	 */
1187	if (is_exec)
1188		mdb_nv_set_value(mdb.m_rcount, count);
1189
1190	/*
1191	 * We can now return if the repeat count is zero.
1192	 */
1193	if (count == 0)
1194		return (DCMD_OK);
1195
1196	/*
1197	 * To guard against bad dcmds, we avoid passing the actual argv that
1198	 * we will use to free argument strings directly to the dcmd.  Instead,
1199	 * we pass a copy that will be garbage collected automatically.
1200	 */
1201	argc = avp->a_nelems;
1202	argv = mdb_alloc(sizeof (mdb_arg_t) * argc, UM_SLEEP | UM_GC);
1203	bcopy(avp->a_data, argv, sizeof (mdb_arg_t) * argc);
1204
1205	if (mdb_addrvec_length(adp) != 0) {
1206		flags |= DCMD_PIPE | DCMD_LOOP | DCMD_LOOPFIRST | DCMD_ADDRSPEC;
1207		addr = mdb_addrvec_shift(adp);
1208		mdb_nv_set_value(mdb.m_dot, addr);
1209		mdb_vcb_propagate(vcbs);
1210		count = 1;
1211	}
1212
1213	status = dcmd_invoke(idcp, addr, flags, argc, argv, vcbs);
1214	if (DCMD_ABORTED(status))
1215		goto done;
1216
1217	/*
1218	 * If the command is $< and we're not receiving input from a pipe, we
1219	 * ignore the repeat count and just return since the macro file is now
1220	 * pushed on to the input stack.
1221	 */
1222	if (is_exec && mdb_addrvec_length(adp) == 0)
1223		goto done;
1224
1225	/*
1226	 * If we're going to loop, we've already executed the dcmd once,
1227	 * so clear the LOOPFIRST flag before proceeding.
1228	 */
1229	if (flags & DCMD_LOOP)
1230		flags &= ~DCMD_LOOPFIRST;
1231
1232	for (i = 1; i < count; i++) {
1233		addr = mdb_dot_incr(",");
1234		mdb_nv_set_value(mdb.m_dot, addr);
1235		status = dcmd_invoke(idcp, addr, flags, argc, argv, vcbs);
1236		if (DCMD_ABORTED(status))
1237			goto done;
1238	}
1239
1240	while (mdb_addrvec_length(adp) != 0) {
1241		addr = mdb_addrvec_shift(adp);
1242		mdb_nv_set_value(mdb.m_dot, addr);
1243		mdb_vcb_propagate(vcbs);
1244		status = dcmd_invoke(idcp, addr, flags, argc, argv, vcbs);
1245		if (DCMD_ABORTED(status))
1246			goto done;
1247	}
1248done:
1249	mdb_iob_nlflush(mdb.m_out);
1250	return (status);
1251}
1252
1253void
1254mdb_intr_enable(void)
1255{
1256	ASSERT(mdb.m_intr >= 1);
1257	if (mdb.m_intr == 1 && mdb.m_pend != 0) {
1258		(void) mdb_signal_block(SIGINT);
1259		mdb.m_intr = mdb.m_pend = 0;
1260		mdb_dprintf(MDB_DBG_DSTK, "delivering pending INT\n");
1261		longjmp(mdb.m_frame->f_pcb, MDB_ERR_SIGINT);
1262	} else
1263		mdb.m_intr--;
1264}
1265
1266void
1267mdb_intr_disable(void)
1268{
1269	mdb.m_intr++;
1270	ASSERT(mdb.m_intr >= 1);
1271}
1272
1273/*
1274 * Create an encoded string representing the internal user-modifiable
1275 * configuration of the debugger and return a pointer to it.  The string can be
1276 * used to initialize another instance of the debugger with the same
1277 * configuration as this one.
1278 */
1279char *
1280mdb_get_config(void)
1281{
1282	size_t r, n = 0;
1283	char *s = NULL;
1284
1285	while ((r = mdb_snprintf(s, n,
1286	    "%x;%x;%x;%x;%x;%x;%lx;%x;%x;%s;%s;%s;%s;%s",
1287	    mdb.m_tgtflags, mdb.m_flags, mdb.m_debug, mdb.m_radix, mdb.m_nargs,
1288	    mdb.m_histlen, (ulong_t)mdb.m_symdist, mdb.m_execmode,
1289	    mdb.m_forkmode, mdb.m_root, mdb.m_termtype, mdb.m_ipathstr,
1290	    mdb.m_lpathstr, mdb.m_prompt)) > n) {
1291
1292		mdb_free(s, n);
1293		n = r + 1;
1294		s = mdb_alloc(r + 1, UM_SLEEP);
1295	}
1296
1297	return (s);
1298}
1299
1300/*
1301 * Decode a configuration string created with mdb_get_config() and reset the
1302 * appropriate parts of the global mdb_t accordingly.
1303 */
1304void
1305mdb_set_config(const char *s)
1306{
1307	const char *p;
1308	size_t len;
1309
1310	if ((p = strchr(s, ';')) != NULL) {
1311		mdb.m_tgtflags = strntoul(s, (size_t)(p - s), 16);
1312		s = p + 1;
1313	}
1314
1315	if ((p = strchr(s, ';')) != NULL) {
1316		mdb.m_flags = strntoul(s, (size_t)(p - s), 16);
1317		mdb.m_flags &= ~(MDB_FL_LOG | MDB_FL_LATEST);
1318		s = p + 1;
1319	}
1320
1321	if ((p = strchr(s, ';')) != NULL) {
1322		mdb.m_debug = strntoul(s, (size_t)(p - s), 16);
1323		s = p + 1;
1324	}
1325
1326	if ((p = strchr(s, ';')) != NULL) {
1327		mdb.m_radix = (int)strntoul(s, (size_t)(p - s), 16);
1328		if (mdb.m_radix < 2 || mdb.m_radix > 16)
1329			mdb.m_radix = MDB_DEF_RADIX;
1330		s = p + 1;
1331	}
1332
1333	if ((p = strchr(s, ';')) != NULL) {
1334		mdb.m_nargs = (int)strntoul(s, (size_t)(p - s), 16);
1335		mdb.m_nargs = MAX(mdb.m_nargs, 0);
1336		s = p + 1;
1337	}
1338
1339	if ((p = strchr(s, ';')) != NULL) {
1340		mdb.m_histlen = (int)strntoul(s, (size_t)(p - s), 16);
1341		mdb.m_histlen = MAX(mdb.m_histlen, 1);
1342		s = p + 1;
1343	}
1344
1345	if ((p = strchr(s, ';')) != NULL) {
1346		mdb.m_symdist = strntoul(s, (size_t)(p - s), 16);
1347		s = p + 1;
1348	}
1349
1350	if ((p = strchr(s, ';')) != NULL) {
1351		mdb.m_execmode = (uchar_t)strntoul(s, (size_t)(p - s), 16);
1352		if (mdb.m_execmode > MDB_EM_FOLLOW)
1353			mdb.m_execmode = MDB_EM_ASK;
1354		s = p + 1;
1355	}
1356
1357	if ((p = strchr(s, ';')) != NULL) {
1358		mdb.m_forkmode = (uchar_t)strntoul(s, (size_t)(p - s), 16);
1359		if (mdb.m_forkmode > MDB_FM_CHILD)
1360			mdb.m_forkmode = MDB_FM_ASK;
1361		s = p + 1;
1362	}
1363
1364	if ((p = strchr(s, ';')) != NULL) {
1365		mdb.m_root = strndup(s, (size_t)(p - s));
1366		s = p + 1;
1367	}
1368
1369	if ((p = strchr(s, ';')) != NULL) {
1370		mdb.m_termtype = strndup(s, (size_t)(p - s));
1371		s = p + 1;
1372	}
1373
1374	if ((p = strchr(s, ';')) != NULL) {
1375		size_t len = MIN(sizeof (mdb.m_ipathstr) - 1, p - s);
1376		(void) strncpy(mdb.m_ipathstr, s, len);
1377		mdb.m_ipathstr[len] = '\0';
1378		s = p + 1;
1379	}
1380
1381	if ((p = strchr(s, ';')) != NULL) {
1382		size_t len = MIN(sizeof (mdb.m_lpathstr) - 1, p - s);
1383		(void) strncpy(mdb.m_lpathstr, s, len);
1384		mdb.m_lpathstr[len] = '\0';
1385		s = p + 1;
1386	}
1387
1388	p = s + strlen(s);
1389	len = MIN(MDB_PROMPTLEN, (size_t)(p - s));
1390	(void) strncpy(mdb.m_prompt, s, len);
1391	mdb.m_prompt[len] = '\0';
1392	mdb.m_promptlen = len;
1393}
1394
1395mdb_module_t *
1396mdb_get_module(void)
1397{
1398	if (mdb.m_lmod)
1399		return (mdb.m_lmod);
1400
1401	if (mdb.m_frame == NULL)
1402		return (NULL);
1403
1404	if (mdb.m_frame->f_wcbs && mdb.m_frame->f_wcbs->w_walker &&
1405	    mdb.m_frame->f_wcbs->w_walker->iwlk_modp &&
1406	    !mdb.m_frame->f_cbactive)
1407		return (mdb.m_frame->f_wcbs->w_walker->iwlk_modp);
1408
1409	if (mdb.m_frame->f_cp && mdb.m_frame->f_cp->c_dcmd)
1410		return (mdb.m_frame->f_cp->c_dcmd->idc_modp);
1411
1412	return (NULL);
1413}
1414