xref: /illumos-gate/usr/src/cmd/sgs/rtld/common/dlfcns.c (revision 67d74cc3)
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 (c) 1988 AT&T
24  *	  All Rights Reserved
25  *
26  * Copyright (c) 1990, 2010, Oracle and/or its affiliates. All rights reserved.
27  * Copyright (c) 2012, Joyent, Inc. All rights reserved.
28  */
29 
30 /*
31  * Programmatic interface to the run_time linker.
32  */
33 
34 #include	<sys/debug.h>
35 #include	<stdio.h>
36 #include	<string.h>
37 #include	<dlfcn.h>
38 #include	<synch.h>
39 #include	<limits.h>
40 #include	<debug.h>
41 #include	<conv.h>
42 #include	"_rtld.h"
43 #include	"_audit.h"
44 #include	"_elf.h"
45 #include	"_inline_gen.h"
46 #include	"msg.h"
47 
48 /*
49  * Determine who called us - given a pc determine in which object it resides.
50  *
51  * For dlopen() the link map of the caller must be passed to load_so() so that
52  * the appropriate search rules (4.x or 5.0) are used to locate any
53  * dependencies.  Also, if we've been called from a 4.x module it may be
54  * necessary to fix the specified pathname so that it conforms with the 5.0 elf
55  * rules.
56  *
57  * For dlsym() the link map of the caller is used to determine RTLD_NEXT
58  * requests, together with requests based off of a dlopen(0).
59  * For dladdr() this routines provides a generic means of scanning all loaded
60  * segments.
61  */
62 Rt_map *
_caller(caddr_t cpc,int flags)63 _caller(caddr_t cpc, int flags)
64 {
65 	Lm_list	*lml;
66 	Aliste	idx1;
67 
68 	for (APLIST_TRAVERSE(dynlm_list, idx1, lml)) {
69 		Aliste	idx2;
70 		Lm_cntl	*lmc;
71 
72 		for (ALIST_TRAVERSE(lml->lm_lists, idx2, lmc)) {
73 			Rt_map	*lmp;
74 
75 			for (lmp = lmc->lc_head; lmp;
76 			    lmp = NEXT_RT_MAP(lmp)) {
77 
78 				if (find_segment(cpc, lmp))
79 					return (lmp);
80 			}
81 		}
82 	}
83 
84 	/*
85 	 * No mapping can be determined.  If asked for a default, assume this
86 	 * is from the executable.
87 	 */
88 	if (flags & CL_EXECDEF)
89 		return ((Rt_map *)lml_main.lm_head);
90 
91 	return (0);
92 }
93 
94 #pragma weak _dlerror = dlerror
95 
96 /*
97  * External entry for dlerror(3dl).  Returns a pointer to the string describing
98  * the last occurring error.  The last occurring error is cleared.
99  */
100 char *
dlerror()101 dlerror()
102 {
103 	char	*error;
104 	Rt_map	*clmp;
105 	int	entry;
106 
107 	entry = enter(0);
108 
109 	clmp = _caller(caller(), CL_EXECDEF);
110 
111 	DBG_CALL(Dbg_dl_dlerror(clmp, lasterr));
112 
113 	error = lasterr;
114 	lasterr = NULL;
115 
116 	if (entry)
117 		leave(LIST(clmp), 0);
118 	return (error);
119 }
120 
121 /*
122  * Add a dependency as a group descriptor to a group handle.  Returns 0 on
123  * failure.  On success, returns the group descriptor, and if alep is non-NULL
124  * the *alep is set to ALE_EXISTS if the dependency already exists, or to
125  * ALE_CREATE if the dependency is newly created.
126  */
127 Grp_desc *
hdl_add(Grp_hdl * ghp,Rt_map * lmp,uint_t dflags,int * alep)128 hdl_add(Grp_hdl *ghp, Rt_map *lmp, uint_t dflags, int *alep)
129 {
130 	Grp_desc	*gdp;
131 	Aliste		idx;
132 	int		ale = ALE_CREATE;
133 	uint_t		oflags;
134 
135 	/*
136 	 * Make sure this dependency hasn't already been recorded.
137 	 */
138 	for (ALIST_TRAVERSE(ghp->gh_depends, idx, gdp)) {
139 		if (gdp->gd_depend == lmp) {
140 			ale = ALE_EXISTS;
141 			break;
142 		}
143 	}
144 
145 	if (ale == ALE_CREATE) {
146 		Grp_desc	gd;
147 
148 		/*
149 		 * Create a new handle descriptor.
150 		 */
151 		gd.gd_depend = lmp;
152 		gd.gd_flags = 0;
153 
154 		/*
155 		 * Indicate this object is a part of this handles group.
156 		 */
157 		if (aplist_append(&GROUPS(lmp), ghp, AL_CNT_GROUPS) == NULL)
158 			return (NULL);
159 
160 		/*
161 		 * Append the new dependency to this handle.
162 		 */
163 		if ((gdp = alist_append(&ghp->gh_depends, &gd,
164 		    sizeof (Grp_desc), AL_CNT_DEPENDS)) == NULL)
165 			return (NULL);
166 	}
167 
168 	oflags = gdp->gd_flags;
169 	gdp->gd_flags |= dflags;
170 
171 	if (DBG_ENABLED) {
172 		if (ale == ALE_CREATE)
173 			DBG_CALL(Dbg_file_hdl_action(ghp, lmp, DBG_DEP_ADD,
174 			    gdp->gd_flags));
175 		else if (gdp->gd_flags != oflags)
176 			DBG_CALL(Dbg_file_hdl_action(ghp, lmp, DBG_DEP_UPDATE,
177 			    gdp->gd_flags));
178 	}
179 
180 	if (alep)
181 		*alep = ale;
182 	return (gdp);
183 }
184 
185 /*
186  * Create a handle.
187  *
188  *   rlmp -	represents the reference link-map for which the handle is being
189  *		created.
190  *   clmp -	represents the caller who is requesting the handle.
191  *   hflags -	provide group handle flags (GPH_*) that affect the use of the
192  *		handle, such as dlopen(0), or use or use of RTLD_FIRST.
193  *   rdflags -	provide group dependency flags for the reference link-map rlmp,
194  *		such as whether the dependency can be used for dlsym(), can be
195  *		relocated against, or whether this objects dependencies should
196  *		be processed.
197  *   cdflags -	provide group dependency flags for the caller.
198  */
199 Grp_hdl *
hdl_create(Lm_list * lml,Rt_map * rlmp,Rt_map * clmp,uint_t hflags,uint_t rdflags,uint_t cdflags)200 hdl_create(Lm_list *lml, Rt_map *rlmp, Rt_map *clmp, uint_t hflags,
201     uint_t rdflags, uint_t cdflags)
202 {
203 	Grp_hdl	*ghp = NULL, *aghp;
204 	APlist	**alpp;
205 	Aliste	idx;
206 
207 	/*
208 	 * For dlopen(0) the handle is maintained as part of the link-map list,
209 	 * otherwise the handle is associated with the reference link-map.
210 	 */
211 	if (hflags & GPH_ZERO)
212 		alpp = &(lml->lm_handle);
213 	else
214 		alpp = &(HANDLES(rlmp));
215 
216 	/*
217 	 * Objects can contain multiple handles depending on the handle flags
218 	 * supplied.  Most RTLD flags pertain to the object itself and the
219 	 * bindings that it can achieve.  Multiple handles for these flags
220 	 * don't make sense.  But if the flag determines how the handle might
221 	 * be used, then multiple handles may exist.  Presently this only makes
222 	 * sense for RTLD_FIRST.  Determine if an appropriate handle already
223 	 * exists.
224 	 */
225 	for (APLIST_TRAVERSE(*alpp, idx, aghp)) {
226 		if ((aghp->gh_flags & GPH_FIRST) == (hflags & GPH_FIRST)) {
227 			ghp = aghp;
228 			break;
229 		}
230 	}
231 
232 	if (ghp == NULL) {
233 		uint_t	ndx;
234 
235 		/*
236 		 * If this is the first request for this handle, allocate and
237 		 * initialize a new handle.
238 		 */
239 		DBG_CALL(Dbg_file_hdl_title(DBG_HDL_CREATE));
240 
241 		if ((ghp = malloc(sizeof (Grp_hdl))) == NULL)
242 			return (NULL);
243 
244 		/*
245 		 * Associate the handle with the link-map list or the reference
246 		 * link-map as appropriate.
247 		 */
248 		if (aplist_append(alpp, ghp, AL_CNT_GROUPS) == NULL) {
249 			free(ghp);
250 			return (NULL);
251 		}
252 
253 		/*
254 		 * Record the existence of this handle for future verification.
255 		 */
256 		/* LINTED */
257 		ndx = (uintptr_t)ghp % HDLIST_SZ;
258 
259 		if (aplist_append(&hdl_alp[ndx], ghp, AL_CNT_HANDLES) == NULL) {
260 			(void) aplist_delete_value(*alpp, ghp);
261 			free(ghp);
262 			return (NULL);
263 		}
264 
265 		ghp->gh_depends = NULL;
266 		ghp->gh_refcnt = 1;
267 		ghp->gh_flags = hflags;
268 
269 		/*
270 		 * A dlopen(0) handle is identified by the GPH_ZERO flag, the
271 		 * head of the link-map list is defined as the owner.  There is
272 		 * no need to maintain a list of dependencies, for when this
273 		 * handle is used (for dlsym()) a dynamic search through the
274 		 * entire link-map list provides for searching all objects with
275 		 * GLOBAL visibility.
276 		 */
277 		if (hflags & GPH_ZERO) {
278 			ghp->gh_ownlmp = lml->lm_head;
279 			ghp->gh_ownlml = lml;
280 		} else {
281 			ghp->gh_ownlmp = rlmp;
282 			ghp->gh_ownlml = LIST(rlmp);
283 
284 			if (hdl_add(ghp, rlmp, rdflags, NULL) == NULL)
285 				return (NULL);
286 
287 			/*
288 			 * If this new handle is a private handle, there's no
289 			 * need to track the caller, so we're done.
290 			 */
291 			if (hflags & GPH_PRIVATE)
292 				return (ghp);
293 
294 			/*
295 			 * If this new handle is public, and isn't a special
296 			 * handle representing ld.so.1, indicate that a local
297 			 * group now exists.  This state allows singleton
298 			 * searches to be optimized.
299 			 */
300 			if ((hflags & GPH_LDSO) == 0)
301 				LIST(rlmp)->lm_flags |= LML_FLG_GROUPSEXIST;
302 		}
303 	} else {
304 		/*
305 		 * If a handle already exists, bump its reference count.
306 		 *
307 		 * If the previous reference count was 0, then this is a handle
308 		 * that an earlier call to dlclose() was unable to remove.  Such
309 		 * handles are put on the orphan list.  As this handle is back
310 		 * in use, it must be removed from the orphan list.
311 		 *
312 		 * Note, handles associated with a link-map list itself (i.e.
313 		 * dlopen(0)) can have a reference count of 0.  However, these
314 		 * handles are never deleted, and therefore are never moved to
315 		 * the orphan list.
316 		 */
317 		if ((ghp->gh_refcnt++ == 0) &&
318 		    ((ghp->gh_flags & GPH_ZERO) == 0)) {
319 			uint_t	ndx;
320 
321 			/* LINTED */
322 			ndx = (uintptr_t)ghp % HDLIST_SZ;
323 
324 			(void) aplist_delete_value(hdl_alp[HDLIST_ORP], ghp);
325 			(void) aplist_append(&hdl_alp[ndx], ghp,
326 			    AL_CNT_HANDLES);
327 
328 			if (DBG_ENABLED) {
329 				Aliste		idx;
330 				Grp_desc	*gdp;
331 
332 				DBG_CALL(Dbg_file_hdl_title(DBG_HDL_REINST));
333 				for (ALIST_TRAVERSE(ghp->gh_depends, idx, gdp))
334 					DBG_CALL(Dbg_file_hdl_action(ghp,
335 					    gdp->gd_depend, DBG_DEP_REINST, 0));
336 			}
337 		}
338 
339 		/*
340 		 * If we've been asked to create a private handle, there's no
341 		 * need to track the caller.
342 		 */
343 		if (hflags & GPH_PRIVATE) {
344 			/*
345 			 * Negate the reference count increment.
346 			 */
347 			ghp->gh_refcnt--;
348 			return (ghp);
349 		} else {
350 			/*
351 			 * If a private handle already exists, promote this
352 			 * handle to public by initializing both the reference
353 			 * count and the handle flags.
354 			 */
355 			if (ghp->gh_flags & GPH_PRIVATE) {
356 				ghp->gh_refcnt = 1;
357 				ghp->gh_flags &= ~GPH_PRIVATE;
358 				ghp->gh_flags |= hflags;
359 			}
360 		}
361 	}
362 
363 	/*
364 	 * Keep track of the parent (caller).  As this object can be referenced
365 	 * by different parents, this processing is carried out every time a
366 	 * handle is requested.
367 	 */
368 	if (clmp && (hdl_add(ghp, clmp, cdflags, NULL) == NULL))
369 		return (NULL);
370 
371 	return (ghp);
372 }
373 
374 /*
375  * Initialize a handle that has been created for an object that is already
376  * loaded.  The handle is initialized with the present dependencies of that
377  * object.  Once this initialization has occurred, any new objects that might
378  * be loaded as dependencies (lazy-loading) are added to the handle as each new
379  * object is loaded.
380  */
381 int
hdl_initialize(Grp_hdl * ghp,Rt_map * nlmp,int mode,int promote)382 hdl_initialize(Grp_hdl *ghp, Rt_map *nlmp, int mode, int promote)
383 {
384 	Aliste		idx;
385 	Grp_desc	*gdp;
386 
387 	/*
388 	 * If the handle has already been initialized, and the initial object's
389 	 * mode hasn't been promoted, there's no need to recompute the modes of
390 	 * any dependencies.  If the object we've added has just been opened,
391 	 * the objects dependencies will not yet have been processed.  These
392 	 * dependencies will be added on later calls to load_one().  Otherwise,
393 	 * this object already exists, so add all of its dependencies to the
394 	 * handle were operating on.
395 	 */
396 	if (((ghp->gh_flags & GPH_INITIAL) && (promote == 0)) ||
397 	    ((FLAGS(nlmp) & FLG_RT_ANALYZED) == 0)) {
398 		ghp->gh_flags |= GPH_INITIAL;
399 		return (1);
400 	}
401 
402 	DBG_CALL(Dbg_file_hdl_title(DBG_HDL_ADD));
403 	for (ALIST_TRAVERSE(ghp->gh_depends, idx, gdp)) {
404 		Rt_map		*lmp = gdp->gd_depend;
405 		Aliste		idx1;
406 		Bnd_desc	*bdp;
407 
408 		/*
409 		 * If this dependency doesn't indicate that its dependencies
410 		 * should be added to a handle, ignore it.  This case identifies
411 		 * a parent of a dlopen(RTLD_PARENT) request.
412 		 */
413 		if ((gdp->gd_flags & GPD_ADDEPS) == 0)
414 			continue;
415 
416 		for (APLIST_TRAVERSE(DEPENDS(lmp), idx1, bdp)) {
417 			Rt_map	*dlmp = bdp->b_depend;
418 
419 			if ((bdp->b_flags & BND_NEEDED) == 0)
420 				continue;
421 
422 			if (hdl_add(ghp, dlmp,
423 			    (GPD_DLSYM | GPD_RELOC | GPD_ADDEPS), NULL) == NULL)
424 				return (0);
425 
426 			(void) update_mode(dlmp, MODE(dlmp), mode);
427 		}
428 	}
429 	ghp->gh_flags |= GPH_INITIAL;
430 	return (1);
431 }
432 
433 /*
434  * Sanity check a program-provided handle.
435  */
436 static int
hdl_validate(Grp_hdl * ghp)437 hdl_validate(Grp_hdl *ghp)
438 {
439 	Aliste		idx;
440 	Grp_hdl		*lghp;
441 	uint_t		ndx;
442 
443 	/* LINTED */
444 	ndx = (uintptr_t)ghp % HDLIST_SZ;
445 
446 	for (APLIST_TRAVERSE(hdl_alp[ndx], idx, lghp)) {
447 		if ((lghp == ghp) && (ghp->gh_refcnt != 0))
448 			return (1);
449 	}
450 	return (0);
451 }
452 
453 /*
454  * Core dlclose activity.
455  */
456 int
dlclose_core(Grp_hdl * ghp,Rt_map * clmp,Lm_list * lml)457 dlclose_core(Grp_hdl *ghp, Rt_map *clmp, Lm_list *lml)
458 {
459 	int	error;
460 	Rt_map	*lmp;
461 
462 	/*
463 	 * If we're already at atexit() there's no point processing further,
464 	 * all objects have already been tsorted for fini processing.
465 	 */
466 	if (rtld_flags & RT_FL_ATEXIT)
467 		return (0);
468 
469 	/*
470 	 * Diagnose what we're up to.
471 	 */
472 	if (ghp->gh_flags & GPH_ZERO) {
473 		DBG_CALL(Dbg_dl_dlclose(clmp, MSG_ORIG(MSG_STR_ZERO),
474 		    DBG_DLCLOSE_IGNORE));
475 	} else {
476 		DBG_CALL(Dbg_dl_dlclose(clmp, NAME(ghp->gh_ownlmp),
477 		    DBG_DLCLOSE_NULL));
478 	}
479 
480 	/*
481 	 * Decrement reference count of this object.
482 	 */
483 	if (--(ghp->gh_refcnt))
484 		return (0);
485 
486 	/*
487 	 * If this handle is special (dlopen(0)), then leave it around - it
488 	 * has little overhead.
489 	 */
490 	if (ghp->gh_flags & GPH_ZERO)
491 		return (0);
492 
493 	/*
494 	 * If this handle is associated with an object that is not on the base
495 	 * link-map control list, or it has not yet been relocated, then this
496 	 * handle must have originated from an auditors interaction, or some
497 	 * permutation of RTLD_CONFGEN use (crle(1), moe(1), etc.).  User code
498 	 * can only execute and bind to relocated objects on the base link-map
499 	 * control list.  Outside of RTLD_CONFGEN use, a non-relocated object,
500 	 * or an object on a non-base link-map control list, is in the process
501 	 * of being loaded, and therefore we do not attempt to remove the
502 	 * handle.
503 	 */
504 	if (((lmp = ghp->gh_ownlmp) != NULL) &&
505 	    ((MODE(lmp) & RTLD_CONFGEN) == 0) &&
506 	    ((CNTL(lmp) != ALIST_OFF_DATA) ||
507 	    ((FLAGS(lmp) & FLG_RT_RELOCED) == 0)))
508 		return (0);
509 
510 	/*
511 	 * This handle is no longer being referenced, remove it.  If this handle
512 	 * is part of an alternative link-map list, determine if the whole list
513 	 * can be removed also.
514 	 */
515 	error = remove_hdl(ghp, clmp, NULL);
516 
517 	if ((lml->lm_flags & (LML_FLG_BASELM | LML_FLG_RTLDLM)) == 0)
518 		remove_lml(lml);
519 
520 	return (error);
521 }
522 
523 /*
524  * Internal dlclose activity.  Called from user level or directly for internal
525  * error cleanup.
526  */
527 int
dlclose_intn(Grp_hdl * ghp,Rt_map * clmp)528 dlclose_intn(Grp_hdl *ghp, Rt_map *clmp)
529 {
530 	Rt_map	*nlmp = NULL;
531 	Lm_list	*olml = NULL;
532 	int	error;
533 
534 	/*
535 	 * Although we're deleting object(s) it's quite possible that additional
536 	 * objects get loaded from running the .fini section(s) of the objects
537 	 * being deleted.  These objects will have been added to the same
538 	 * link-map list as those objects being deleted.  Remember this list
539 	 * for later investigation.
540 	 */
541 	olml = ghp->gh_ownlml;
542 
543 	error = dlclose_core(ghp, clmp, olml);
544 
545 	/*
546 	 * Determine whether the original link-map list still exists.  In the
547 	 * case of a dlclose of an alternative (dlmopen) link-map the whole
548 	 * list may have been removed.
549 	 */
550 	if (olml) {
551 		Aliste	idx;
552 		Lm_list	*lml;
553 
554 		for (APLIST_TRAVERSE(dynlm_list, idx, lml)) {
555 			if (olml == lml) {
556 				nlmp = olml->lm_head;
557 				break;
558 			}
559 		}
560 	}
561 	load_completion(nlmp);
562 	return (error);
563 }
564 
565 /*
566  * Argument checking for dlclose.  Only called via external entry.
567  */
568 static int
dlclose_check(void * handle,Rt_map * clmp)569 dlclose_check(void *handle, Rt_map *clmp)
570 {
571 	Grp_hdl	*ghp = (Grp_hdl *)handle;
572 
573 	if (hdl_validate(ghp) == 0) {
574 		Conv_inv_buf_t	inv_buf;
575 
576 		(void) conv_invalid_val(&inv_buf, EC_NATPTR(ghp), 0);
577 		DBG_CALL(Dbg_dl_dlclose(clmp, inv_buf.buf, DBG_DLCLOSE_NULL));
578 
579 		eprintf(LIST(clmp), ERR_FATAL, MSG_INTL(MSG_ARG_INVHNDL),
580 		    EC_NATPTR(handle));
581 		return (1);
582 	}
583 	return (dlclose_intn(ghp, clmp));
584 }
585 
586 #pragma weak _dlclose = dlclose
587 
588 /*
589  * External entry for dlclose(3dl).  Returns 0 for success, non-zero otherwise.
590  */
591 int
dlclose(void * handle)592 dlclose(void *handle)
593 {
594 	int		error, entry;
595 	Rt_map		*clmp;
596 
597 	entry = enter(0);
598 
599 	clmp = _caller(caller(), CL_EXECDEF);
600 
601 	error = dlclose_check(handle, clmp);
602 
603 	if (entry)
604 		leave(LIST(clmp), 0);
605 	return (error);
606 }
607 
608 static uint_t	lmid = 0;
609 
610 /*
611  * The addition of new link-map lists is assumed to be in small quantities.
612  * Here, we assign a unique link-map id for diagnostic use.  Simply update the
613  * running link-map count until we max out.
614  */
615 int
newlmid(Lm_list * lml)616 newlmid(Lm_list *lml)
617 {
618 	char	buffer[MSG_LMID_ALT_SIZE + 12];
619 
620 	if (lmid == UINT_MAX) {
621 		lml->lm_lmid = UINT_MAX;
622 		(void) strncpy(buffer, MSG_ORIG(MSG_LMID_MAXED),
623 		    MSG_LMID_ALT_SIZE + 12);
624 	} else {
625 		lml->lm_lmid = lmid++;
626 		(void) snprintf(buffer, MSG_LMID_ALT_SIZE + 12,
627 		    MSG_ORIG(MSG_LMID_FMT), MSG_ORIG(MSG_LMID_ALT),
628 		    lml->lm_lmid);
629 	}
630 	if ((lml->lm_lmidstr = strdup(buffer)) == NULL)
631 		return (0);
632 
633 	return (1);
634 }
635 
636 /*
637  * Core dlopen activity.
638  */
639 static Grp_hdl *
dlmopen_core(Lm_list * lml,Lm_list * olml,const char * path,int mode,Rt_map * clmp,uint_t flags,uint_t orig,int * in_nfavl)640 dlmopen_core(Lm_list *lml, Lm_list *olml, const char *path, int mode,
641     Rt_map *clmp, uint_t flags, uint_t orig, int *in_nfavl)
642 {
643 	Alist		*palp = NULL;
644 	Rt_map		*nlmp;
645 	Grp_hdl		*ghp;
646 	Aliste		olmco, nlmco;
647 
648 	DBG_CALL(Dbg_dl_dlopen(clmp,
649 	    (path ? path : MSG_ORIG(MSG_STR_ZERO)), in_nfavl, mode));
650 
651 	/*
652 	 * Having diagnosed the originally defined modes, assign any defaults
653 	 * or corrections.
654 	 */
655 	if (((mode & (RTLD_GROUP | RTLD_WORLD)) == 0) &&
656 	    ((mode & RTLD_NOLOAD) == 0))
657 		mode |= (RTLD_GROUP | RTLD_WORLD);
658 	if ((mode & RTLD_NOW) && (rtld_flags2 & RT_FL2_BINDLAZY)) {
659 		mode &= ~RTLD_NOW;
660 		mode |= RTLD_LAZY;
661 	}
662 
663 	/*
664 	 * If the path specified is null then we're operating on global
665 	 * objects.  Associate a dummy handle with the link-map list.
666 	 */
667 	if (path == NULL) {
668 		Grp_hdl *ghp;
669 		uint_t	hflags, rdflags, cdflags;
670 		int	promote = 0;
671 
672 		/*
673 		 * Establish any flags for the handle (Grp_hdl).
674 		 *
675 		 *  -	This is a dummy, public, handle (0) that provides for a
676 		 *	dynamic	search of all global objects within the process.
677 		 *  -   Use of the RTLD_FIRST mode indicates that only the first
678 		 *	dependency on the handle (the referenced object) can be
679 		 *	used to satisfy dlsym() requests.
680 		 */
681 		hflags = (GPH_PUBLIC | GPH_ZERO);
682 		if (mode & RTLD_FIRST)
683 			hflags |= GPH_FIRST;
684 
685 		/*
686 		 * Establish the flags for the referenced dependency descriptor
687 		 * (Grp_desc).
688 		 *
689 		 *  -	The referenced object is available for dlsym().
690 		 *  -	The referenced object is available to relocate against.
691 		 *  -	The referenced object should have it's dependencies
692 		 *	added to this handle.
693 		 */
694 		rdflags = (GPD_DLSYM | GPD_RELOC | GPD_ADDEPS);
695 
696 		/*
697 		 * Establish the flags for this callers dependency descriptor
698 		 * (Grp_desc).
699 		 *
700 		 *  -	The explicit creation of a handle creates a descriptor
701 		 *	for the referenced object and the parent (caller).
702 		 *  -	Use of the RTLD_PARENT flag indicates that the parent
703 		 *	can be relocated against.
704 		 */
705 		cdflags = GPD_PARENT;
706 		if (mode & RTLD_PARENT)
707 			cdflags |= GPD_RELOC;
708 
709 		if ((ghp = hdl_create(lml, 0, clmp, hflags, rdflags,
710 		    cdflags)) == NULL)
711 			return (NULL);
712 
713 		/*
714 		 * Traverse the main link-map control list, updating the mode
715 		 * of any objects as necessary.  Call the relocation engine if
716 		 * this mode promotes the existing state of any relocations.
717 		 * crle()'s first pass loads all objects necessary for building
718 		 * a configuration file, however none of them are relocated.
719 		 * crle()'s second pass relocates objects in preparation for
720 		 * dldump()'ing using dlopen(0, RTLD_NOW).
721 		 */
722 		if ((mode & (RTLD_NOW | RTLD_CONFGEN)) == RTLD_CONFGEN)
723 			return (ghp);
724 
725 		for (nlmp = lml->lm_head; nlmp; nlmp = NEXT_RT_MAP(nlmp)) {
726 			if (((MODE(nlmp) & RTLD_GLOBAL) == 0) ||
727 			    (FLAGS(nlmp) & FLG_RT_DELETE))
728 				continue;
729 
730 			if (update_mode(nlmp, MODE(nlmp), mode))
731 				promote = 1;
732 		}
733 		if (promote)
734 			(void) relocate_lmc(lml, ALIST_OFF_DATA, clmp,
735 			    lml->lm_head, in_nfavl);
736 
737 		return (ghp);
738 	}
739 
740 	/*
741 	 * Fix the pathname.  If this object expands to multiple paths (ie.
742 	 * $ISALIST or $HWCAP have been used), then make sure the user has also
743 	 * furnished the RTLD_FIRST flag.  As yet, we don't support opening
744 	 * more than one object at a time, so enforcing the RTLD_FIRST flag
745 	 * provides flexibility should we be able to support dlopening more
746 	 * than one object in the future.
747 	 */
748 	if (LM_FIX_NAME(clmp)(path, clmp, &palp, AL_CNT_NEEDED, orig) == 0)
749 		return (NULL);
750 
751 	if ((palp->al_arritems > 1) && ((mode & RTLD_FIRST) == 0)) {
752 		remove_alist(&palp, 1);
753 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLMODE_5));
754 		return (NULL);
755 	}
756 
757 	/*
758 	 * Establish a link-map control list for this request, and load the
759 	 * associated object.
760 	 */
761 	if ((nlmco = create_cntl(lml, 1)) == 0) {
762 		remove_alist(&palp, 1);
763 		return (NULL);
764 	}
765 	olmco = nlmco;
766 
767 	nlmp = load_one(lml, nlmco, palp, clmp, mode, (flags | FLG_RT_PUBHDL),
768 	    &ghp, in_nfavl);
769 
770 	/*
771 	 * Remove any expanded pathname infrastructure, and if the dependency
772 	 * couldn't be loaded, cleanup.
773 	 */
774 	remove_alist(&palp, 1);
775 	if (nlmp == NULL) {
776 		remove_cntl(lml, olmco);
777 		return (NULL);
778 	}
779 
780 	/*
781 	 * If loading an auditor was requested, and the auditor already existed,
782 	 * then the link-map returned will be to the original auditor.  The new
783 	 * link-map list that was initially created, and the associated link-map
784 	 * control list are no longer needed.  As the auditor is already loaded,
785 	 * we're probably done, but fall through in case additional relocations
786 	 * would be triggered by the mode of the caller.
787 	 */
788 	if ((flags & FLG_RT_AUDIT) && (LIST(nlmp) != lml)) {
789 		remove_cntl(lml, olmco);
790 		lml = LIST(nlmp);
791 		olmco = 0;
792 		nlmco = ALIST_OFF_DATA;
793 	}
794 
795 	/*
796 	 * Finish processing the objects associated with this request.
797 	 */
798 	if (((nlmp = analyze_lmc(lml, nlmco, nlmp, clmp, in_nfavl)) == NULL) ||
799 	    (relocate_lmc(lml, nlmco, clmp, nlmp, in_nfavl) == 0)) {
800 		ghp = NULL;
801 		nlmp = NULL;
802 	}
803 
804 	/*
805 	 * If the dlopen has failed, clean up any objects that might have been
806 	 * loaded successfully on this new link-map control list.
807 	 */
808 	if (olmco && (nlmp == NULL))
809 		remove_lmc(lml, clmp, olmco, path);
810 
811 	/*
812 	 * Finally, remove any temporary link-map control list.  Note, if this
813 	 * operation successfully established a new link-map list, then a base
814 	 * link-map control list will have been created, which must remain.
815 	 */
816 	if (olmco && ((nlmp == NULL) || (olml != (Lm_list *)LM_ID_NEWLM)))
817 		remove_cntl(lml, olmco);
818 
819 	return (ghp);
820 }
821 
822 /*
823  * dlopen() and dlsym() operations are the means by which a process can
824  * test for the existence of required dependencies.  If the necessary
825  * dependencies don't exist, then associated functionality can't be used.
826  * However, the lack of dependencies can be fixed, and the dlopen() and
827  * dlsym() requests can be repeated.  As we use a "not-found" AVL tree to
828  * cache any failed full path loads, secondary dlopen() and dlsym() requests
829  * will fail, even if the dependencies have been installed.
830  *
831  * dlopen() and dlsym() retry any failures by removing the "not-found" AVL
832  * tree.  Should any dependencies be found, their names are added to the
833  * FullPath AVL tree.  This routine removes any new "not-found" AVL tree,
834  * so that the dlopen() or dlsym() can replace the original "not-found" tree.
835  */
836 inline static void
nfavl_remove(avl_tree_t * avlt)837 nfavl_remove(avl_tree_t *avlt)
838 {
839 	PathNode	*pnp;
840 	void		*cookie = NULL;
841 
842 	if (avlt) {
843 		while ((pnp = avl_destroy_nodes(avlt, &cookie)) != NULL)
844 			free(pnp);
845 
846 		avl_destroy(avlt);
847 		free(avlt);
848 	}
849 }
850 
851 /*
852  * Internal dlopen() activity.  Called from user level or directly for internal
853  * opens that require a handle.
854  */
855 Grp_hdl *
dlmopen_intn(Lm_list * lml,const char * path,int mode,Rt_map * clmp,uint_t flags,uint_t orig)856 dlmopen_intn(Lm_list *lml, const char *path, int mode, Rt_map *clmp,
857     uint_t flags, uint_t orig)
858 {
859 	Lm_list	*olml = lml;
860 	Rt_map	*dlmp = NULL;
861 	Grp_hdl	*ghp;
862 	int	in_nfavl = 0;
863 
864 	/*
865 	 * Check for magic link-map list values:
866 	 *
867 	 *  LM_ID_BASE:		Operate on the PRIMARY (executables) link map
868 	 *  LM_ID_LDSO:		Operation on ld.so.1's link map
869 	 *  LM_ID_NEWLM:	Create a new link-map.
870 	 */
871 	if (lml == (Lm_list *)LM_ID_NEWLM) {
872 		if ((lml = calloc(sizeof (Lm_list), 1)) == NULL)
873 			return (NULL);
874 
875 		/*
876 		 * Establish the new link-map flags from the callers and those
877 		 * explicitly provided.
878 		 */
879 		lml->lm_tflags = LIST(clmp)->lm_tflags;
880 		if (flags & FLG_RT_AUDIT) {
881 			/*
882 			 * Unset any auditing flags - an auditor shouldn't be
883 			 * audited.  Insure all audit dependencies are loaded.
884 			 */
885 			lml->lm_tflags &= ~LML_TFLG_AUD_MASK;
886 			lml->lm_tflags |= (LML_TFLG_NOLAZYLD |
887 			    LML_TFLG_LOADFLTR | LML_TFLG_NOAUDIT);
888 		}
889 
890 		if (aplist_append(&dynlm_list, lml, AL_CNT_DYNLIST) == NULL) {
891 			free(lml);
892 			return (NULL);
893 		}
894 		if (newlmid(lml) == 0) {
895 			(void) aplist_delete_value(dynlm_list, lml);
896 			free(lml);
897 			return (NULL);
898 		}
899 	} else if ((uintptr_t)lml < LM_ID_NUM) {
900 		if ((uintptr_t)lml == LM_ID_BASE)
901 			lml = &lml_main;
902 		else if ((uintptr_t)lml == LM_ID_LDSO)
903 			lml = &lml_rtld;
904 	}
905 
906 	/*
907 	 * Open the required object on the associated link-map list.
908 	 */
909 	ghp = dlmopen_core(lml, olml, path, mode, clmp, flags, orig, &in_nfavl);
910 
911 	/*
912 	 * If the object could not be found it is possible that the "not-found"
913 	 * AVL tree had indicated that the file does not exist.  In case the
914 	 * file system has changed since this "not-found" recording was made,
915 	 * retry the dlopen() with a clean "not-found" AVL tree.
916 	 */
917 	if ((ghp == NULL) && in_nfavl) {
918 		avl_tree_t	*oavlt = nfavl;
919 
920 		nfavl = NULL;
921 		ghp = dlmopen_core(lml, olml, path, mode, clmp, flags, orig,
922 		    NULL);
923 
924 		/*
925 		 * If the file is found, then its full path name will have been
926 		 * registered in the FullPath AVL tree.  Remove any new
927 		 * "not-found" AVL information, and restore the former AVL tree.
928 		 */
929 		nfavl_remove(nfavl);
930 		nfavl = oavlt;
931 	}
932 
933 	/*
934 	 * Establish the new link-map from which .init processing will begin.
935 	 * Ignore .init firing when constructing a configuration file (crle(1)).
936 	 */
937 	if (ghp && ((mode & RTLD_CONFGEN) == 0))
938 		dlmp = ghp->gh_ownlmp;
939 
940 	/*
941 	 * If loading an auditor was requested, and the auditor already existed,
942 	 * then the link-map returned will be to the original auditor.  Remove
943 	 * the link-map control list that was created for this request.
944 	 */
945 	if (dlmp && (flags & FLG_RT_AUDIT) && (LIST(dlmp) != lml)) {
946 		remove_lml(lml);
947 		lml = LIST(dlmp);
948 	}
949 
950 	/*
951 	 * If this load failed, remove any alternative link-map list.
952 	 */
953 	if ((ghp == NULL) &&
954 	    ((lml->lm_flags & (LML_FLG_BASELM | LML_FLG_RTLDLM)) == 0)) {
955 		remove_lml(lml);
956 		lml = NULL;
957 	}
958 
959 	/*
960 	 * Finish this load request.  If objects were loaded, .init processing
961 	 * is computed.  Finally, the debuggers are informed of the link-map
962 	 * lists being stable.
963 	 */
964 	load_completion(dlmp);
965 
966 	return (ghp);
967 }
968 
969 /*
970  * Argument checking for dlopen.  Only called via external entry.
971  */
972 static Grp_hdl *
dlmopen_check(Lm_list * lml,const char * path,int mode,Rt_map * clmp)973 dlmopen_check(Lm_list *lml, const char *path, int mode, Rt_map *clmp)
974 {
975 	/*
976 	 * Verify that a valid pathname has been supplied.
977 	 */
978 	if (path && (*path == '\0')) {
979 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLPATH));
980 		return (0);
981 	}
982 
983 	/*
984 	 * Historically we've always verified the mode is either RTLD_NOW or
985 	 * RTLD_LAZY.  RTLD_NOLOAD is valid by itself.  Use of LM_ID_NEWLM
986 	 * requires a specific pathname, and use of RTLD_PARENT is meaningless.
987 	 */
988 	if ((mode & (RTLD_NOW | RTLD_LAZY | RTLD_NOLOAD)) == 0) {
989 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLMODE_1));
990 		return (0);
991 	}
992 	if ((mode & (RTLD_NOW | RTLD_LAZY)) == (RTLD_NOW | RTLD_LAZY)) {
993 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLMODE_2));
994 		return (0);
995 	}
996 	if ((lml == (Lm_list *)LM_ID_NEWLM) && (path == NULL)) {
997 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLMODE_3));
998 		return (0);
999 	}
1000 	if ((lml == (Lm_list *)LM_ID_NEWLM) && (mode & RTLD_PARENT)) {
1001 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLMODE_4));
1002 		return (0);
1003 	}
1004 
1005 	return (dlmopen_intn(lml, path, mode, clmp, 0, 0));
1006 }
1007 
1008 #pragma weak _dlopen = dlopen
1009 
1010 /*
1011  * External entry for dlopen(3dl).  On success, returns a pointer (handle) to
1012  * the structure containing information about the newly added object, ie. can
1013  * be used by dlsym(). On failure, returns a null pointer.
1014  */
1015 void *
dlopen(const char * path,int mode)1016 dlopen(const char *path, int mode)
1017 {
1018 	int	entry;
1019 	Rt_map	*clmp;
1020 	Grp_hdl	*ghp;
1021 	Lm_list	*lml;
1022 
1023 	entry = enter(0);
1024 
1025 	clmp = _caller(caller(), CL_EXECDEF);
1026 	lml = LIST(clmp);
1027 
1028 	ghp = dlmopen_check(lml, path, mode, clmp);
1029 
1030 	if (entry)
1031 		leave(lml, 0);
1032 	return ((void *)ghp);
1033 }
1034 
1035 #pragma weak _dlmopen = dlmopen
1036 
1037 /*
1038  * External entry for dlmopen(3dl).
1039  */
1040 void *
dlmopen(Lmid_t lmid,const char * path,int mode)1041 dlmopen(Lmid_t lmid, const char *path, int mode)
1042 {
1043 	int	entry;
1044 	Rt_map	*clmp;
1045 	Grp_hdl	*ghp;
1046 
1047 	entry = enter(0);
1048 
1049 	clmp = _caller(caller(), CL_EXECDEF);
1050 
1051 	ghp = dlmopen_check((Lm_list *)lmid, path, mode, clmp);
1052 
1053 	if (entry)
1054 		leave(LIST(clmp), 0);
1055 	return ((void *)ghp);
1056 }
1057 
1058 /*
1059  * Handle processing for dlsym.
1060  */
1061 int
dlsym_handle(Grp_hdl * ghp,Slookup * slp,Sresult * srp,uint_t * binfo,int * in_nfavl)1062 dlsym_handle(Grp_hdl *ghp, Slookup *slp, Sresult *srp, uint_t *binfo,
1063     int *in_nfavl)
1064 {
1065 	Rt_map		*nlmp, * lmp = ghp->gh_ownlmp;
1066 	Rt_map		*clmp = slp->sl_cmap;
1067 	const char	*name = slp->sl_name;
1068 	Slookup		sl = *slp;
1069 
1070 	sl.sl_flags = (LKUP_FIRST | LKUP_DLSYM | LKUP_SPEC);
1071 
1072 	/*
1073 	 * Continue processing a dlsym request.  Lookup the required symbol in
1074 	 * each link-map specified by the handle.
1075 	 *
1076 	 * To leverage off of lazy loading, dlsym() requests can result in two
1077 	 * passes.  The first descends the link-maps of any objects already in
1078 	 * the address space.  If the symbol isn't located, and lazy
1079 	 * dependencies still exist, then a second pass is made to load these
1080 	 * dependencies if applicable.  This model means that in the case where
1081 	 * a symbol exists in more than one object, the one located may not be
1082 	 * constant - this is the standard issue with lazy loading. In addition,
1083 	 * attempting to locate a symbol that doesn't exist will result in the
1084 	 * loading of all lazy dependencies on the given handle, which can
1085 	 * defeat some of the advantages of lazy loading (look out JVM).
1086 	 */
1087 	if (ghp->gh_flags & GPH_ZERO) {
1088 		Lm_list	*lml;
1089 		uint_t	lazy = 0;
1090 
1091 		/*
1092 		 * If this symbol lookup is triggered from a dlopen(0) handle,
1093 		 * traverse the present link-map list looking for promiscuous
1094 		 * entries.
1095 		 */
1096 		for (nlmp = lmp; nlmp; nlmp = NEXT_RT_MAP(nlmp)) {
1097 			/*
1098 			 * If this handle indicates we're only to look in the
1099 			 * first object check whether we're done.
1100 			 */
1101 			if ((nlmp != lmp) && (ghp->gh_flags & GPH_FIRST))
1102 				return (0);
1103 
1104 			if (!(MODE(nlmp) & RTLD_GLOBAL))
1105 				continue;
1106 			if ((FLAGS(nlmp) & FLG_RT_DELETE) &&
1107 			    ((FLAGS(clmp) & FLG_RT_DELETE) == 0))
1108 				continue;
1109 
1110 			sl.sl_imap = nlmp;
1111 			if (LM_LOOKUP_SYM(clmp)(&sl, srp, binfo, in_nfavl))
1112 				return (1);
1113 
1114 			/*
1115 			 * Keep track of any global pending lazy loads.
1116 			 */
1117 			lazy += LAZY(nlmp);
1118 		}
1119 
1120 		/*
1121 		 * If we're unable to locate the symbol and this link-map list
1122 		 * still has pending lazy dependencies, start loading them in an
1123 		 * attempt to exhaust the search.  Note that as we're already
1124 		 * traversing a dynamic linked list of link-maps there's no
1125 		 * need for elf_lazy_find_sym() to descend the link-maps itself.
1126 		 */
1127 		lml = LIST(lmp);
1128 		if (lazy) {
1129 			DBG_CALL(Dbg_syms_lazy_rescan(lml, name));
1130 
1131 			sl.sl_flags |= LKUP_NODESCENT;
1132 
1133 			for (nlmp = lmp; nlmp; nlmp = NEXT_RT_MAP(nlmp)) {
1134 
1135 				if (!(MODE(nlmp) & RTLD_GLOBAL) || !LAZY(nlmp))
1136 					continue;
1137 				if ((FLAGS(nlmp) & FLG_RT_DELETE) &&
1138 				    ((FLAGS(clmp) & FLG_RT_DELETE) == 0))
1139 					continue;
1140 
1141 				sl.sl_imap = nlmp;
1142 				if (elf_lazy_find_sym(&sl, srp, binfo,
1143 				    in_nfavl))
1144 					return (1);
1145 			}
1146 		}
1147 	} else {
1148 		/*
1149 		 * Traverse the dlopen() handle searching all presently loaded
1150 		 * link-maps.
1151 		 */
1152 		Grp_desc	*gdp;
1153 		Aliste		idx;
1154 		uint_t		lazy = 0;
1155 
1156 		for (ALIST_TRAVERSE(ghp->gh_depends, idx, gdp)) {
1157 			nlmp = gdp->gd_depend;
1158 
1159 			if ((gdp->gd_flags & GPD_DLSYM) == 0)
1160 				continue;
1161 
1162 			sl.sl_imap = nlmp;
1163 			if (LM_LOOKUP_SYM(clmp)(&sl, srp, binfo, in_nfavl))
1164 				return (1);
1165 
1166 			if (ghp->gh_flags & GPH_FIRST)
1167 				return (0);
1168 
1169 			/*
1170 			 * Keep track of any pending lazy loads associated
1171 			 * with this handle.
1172 			 */
1173 			lazy += LAZY(nlmp);
1174 		}
1175 
1176 		/*
1177 		 * If we're unable to locate the symbol and this handle still
1178 		 * has pending lazy dependencies, start loading the lazy
1179 		 * dependencies, in an attempt to exhaust the search.
1180 		 */
1181 		if (lazy) {
1182 			DBG_CALL(Dbg_syms_lazy_rescan(LIST(lmp), name));
1183 
1184 			for (ALIST_TRAVERSE(ghp->gh_depends, idx, gdp)) {
1185 				nlmp = gdp->gd_depend;
1186 
1187 				if (((gdp->gd_flags & GPD_DLSYM) == 0) ||
1188 				    (LAZY(nlmp) == 0))
1189 					continue;
1190 
1191 				sl.sl_imap = nlmp;
1192 				if (elf_lazy_find_sym(&sl, srp, binfo,
1193 				    in_nfavl))
1194 					return (1);
1195 			}
1196 		}
1197 	}
1198 	return (0);
1199 }
1200 
1201 /*
1202  * Determine whether a symbol resides in a caller.  This may be a reference,
1203  * which is associated with a specific dependency.
1204  */
1205 inline static Sym *
sym_lookup_in_caller(Rt_map * clmp,Slookup * slp,Sresult * srp,uint_t * binfo)1206 sym_lookup_in_caller(Rt_map *clmp, Slookup *slp, Sresult *srp, uint_t *binfo)
1207 {
1208 	if (THIS_IS_ELF(clmp) && SYMINTP(clmp)(slp, srp, binfo, NULL)) {
1209 		Sym	*sym = srp->sr_sym;
1210 
1211 		slp->sl_rsymndx = (((ulong_t)sym -
1212 		    (ulong_t)SYMTAB(clmp)) / SYMENT(clmp));
1213 		slp->sl_rsym = sym;
1214 		return (sym);
1215 	}
1216 	return (NULL);
1217 }
1218 
1219 /*
1220  * Core dlsym activity.  Selects symbol lookup method from handle.
1221  */
1222 static void *
dlsym_core(void * handle,const char * name,Rt_map * clmp,Rt_map ** dlmp,int * in_nfavl)1223 dlsym_core(void *handle, const char *name, Rt_map *clmp, Rt_map **dlmp,
1224     int *in_nfavl)
1225 {
1226 	Sym		*sym;
1227 	int		ret = 0;
1228 	Syminfo		*sip;
1229 	Slookup		sl;
1230 	Sresult		sr;
1231 	uint_t		binfo;
1232 
1233 	/*
1234 	 * Initialize the symbol lookup data structure.
1235 	 *
1236 	 * Standard relocations are evaluated using the symbol index of the
1237 	 * associated relocation symbol.  This index provides for loading
1238 	 * any lazy dependency and establishing a direct binding if necessary.
1239 	 * If a dlsym() operation originates from an object that contains a
1240 	 * symbol table entry for the same name, then we need to establish the
1241 	 * symbol index so that any dependency requirements can be triggered.
1242 	 *
1243 	 * Therefore, the first symbol lookup that is carried out is for the
1244 	 * symbol name within the calling object.  If this symbol exists, the
1245 	 * symbols index is computed, added to the Slookup data, and thus used
1246 	 * to seed the real symbol lookup.
1247 	 */
1248 	SLOOKUP_INIT(sl, name, clmp, clmp, ld_entry_cnt, elf_hash(name),
1249 	    0, 0, 0, LKUP_SYMNDX);
1250 	SRESULT_INIT(sr, name);
1251 	sym = sym_lookup_in_caller(clmp, &sl, &sr, &binfo);
1252 
1253 	SRESULT_INIT(sr, name);
1254 
1255 	if (sym && (ELF_ST_VISIBILITY(sym->st_other) == STV_SINGLETON)) {
1256 		Rt_map	*hlmp = LIST(clmp)->lm_head;
1257 
1258 		/*
1259 		 * If a symbol reference is known, and that reference indicates
1260 		 * that the symbol is a singleton, then the search for the
1261 		 * symbol must follow the default search path.
1262 		 */
1263 		DBG_CALL(Dbg_dl_dlsym(clmp, name, in_nfavl, 0,
1264 		    DBG_DLSYM_SINGLETON));
1265 
1266 		sl.sl_imap = hlmp;
1267 		if (handle == RTLD_PROBE)
1268 			sl.sl_flags = LKUP_NOFALLBACK;
1269 		else
1270 			sl.sl_flags = LKUP_SPEC;
1271 		ret = LM_LOOKUP_SYM(clmp)(&sl, &sr, &binfo, in_nfavl);
1272 
1273 	} else if (handle == RTLD_NEXT) {
1274 		Rt_map	*nlmp;
1275 
1276 		/*
1277 		 * If this handle is RTLD_NEXT determine whether a lazy load
1278 		 * from the caller might provide the next object.  This mimics
1279 		 * the lazy loading initialization normally carried out by
1280 		 * lookup_sym(), however here, we must do this up-front, as
1281 		 * lookup_sym() will be used to inspect the next object.
1282 		 */
1283 		if ((sl.sl_rsymndx) && ((sip = SYMINFO(clmp)) != NULL)) {
1284 			/* LINTED */
1285 			sip = (Syminfo *)((char *)sip +
1286 			    (sl.sl_rsymndx * SYMINENT(clmp)));
1287 
1288 			if ((sip->si_flags & SYMINFO_FLG_DIRECT) &&
1289 			    (sip->si_boundto < SYMINFO_BT_LOWRESERVE))
1290 				(void) elf_lazy_load(clmp, &sl,
1291 				    sip->si_boundto, name, 0, NULL, in_nfavl);
1292 
1293 			/*
1294 			 * Clear the symbol index, so as not to confuse
1295 			 * lookup_sym() of the next object.
1296 			 */
1297 			sl.sl_rsymndx = 0;
1298 			sl.sl_rsym = NULL;
1299 		}
1300 
1301 		/*
1302 		 * If the handle is RTLD_NEXT, start searching in the next link
1303 		 * map from the callers.  Determine permissions from the
1304 		 * present link map.  Indicate to lookup_sym() that we're on an
1305 		 * RTLD_NEXT request so that it will use the callers link map to
1306 		 * start any possible lazy dependency loading.
1307 		 */
1308 		sl.sl_imap = nlmp = NEXT_RT_MAP(clmp);
1309 
1310 		DBG_CALL(Dbg_dl_dlsym(clmp, name, in_nfavl,
1311 		    (nlmp ? NAME(nlmp) : MSG_INTL(MSG_STR_NULL)),
1312 		    DBG_DLSYM_NEXT));
1313 
1314 		if (nlmp == NULL)
1315 			return (0);
1316 
1317 		sl.sl_flags = LKUP_NEXT;
1318 		ret = LM_LOOKUP_SYM(clmp)(&sl, &sr, &binfo, in_nfavl);
1319 
1320 	} else if (handle == RTLD_SELF) {
1321 		/*
1322 		 * If the handle is RTLD_SELF start searching from the caller.
1323 		 */
1324 		DBG_CALL(Dbg_dl_dlsym(clmp, name, in_nfavl, NAME(clmp),
1325 		    DBG_DLSYM_SELF));
1326 
1327 		sl.sl_imap = clmp;
1328 		sl.sl_flags = (LKUP_SPEC | LKUP_SELF);
1329 		ret = LM_LOOKUP_SYM(clmp)(&sl, &sr, &binfo, in_nfavl);
1330 
1331 	} else if (handle == RTLD_DEFAULT) {
1332 		Rt_map	*hlmp = LIST(clmp)->lm_head;
1333 
1334 		/*
1335 		 * If the handle is RTLD_DEFAULT mimic the standard symbol
1336 		 * lookup as would be triggered by a relocation.
1337 		 */
1338 		DBG_CALL(Dbg_dl_dlsym(clmp, name, in_nfavl, 0,
1339 		    DBG_DLSYM_DEFAULT));
1340 
1341 		sl.sl_imap = hlmp;
1342 		sl.sl_flags = LKUP_SPEC;
1343 		ret = LM_LOOKUP_SYM(clmp)(&sl, &sr, &binfo, in_nfavl);
1344 
1345 	} else if (handle == RTLD_PROBE) {
1346 		Rt_map	*hlmp = LIST(clmp)->lm_head;
1347 
1348 		/*
1349 		 * If the handle is RTLD_PROBE, mimic the standard symbol
1350 		 * lookup as would be triggered by a relocation, however do
1351 		 * not fall back to a lazy loading rescan if the symbol can't be
1352 		 * found within the currently loaded objects.  Note, a lazy
1353 		 * loaded dependency required by the caller might still get
1354 		 * loaded to satisfy this request, but no exhaustive lazy load
1355 		 * rescan is carried out.
1356 		 */
1357 		DBG_CALL(Dbg_dl_dlsym(clmp, name, in_nfavl, 0,
1358 		    DBG_DLSYM_PROBE));
1359 
1360 		sl.sl_imap = hlmp;
1361 		sl.sl_flags = LKUP_NOFALLBACK;
1362 		ret = LM_LOOKUP_SYM(clmp)(&sl, &sr, &binfo, in_nfavl);
1363 
1364 	} else {
1365 		Grp_hdl *ghp = (Grp_hdl *)handle;
1366 
1367 		/*
1368 		 * Look in the shared object specified by the handle and in all
1369 		 * of its dependencies.
1370 		 */
1371 		DBG_CALL(Dbg_dl_dlsym(clmp, name, in_nfavl,
1372 		    NAME(ghp->gh_ownlmp), DBG_DLSYM_DEF));
1373 
1374 		ret = LM_DLSYM(clmp)(ghp, &sl, &sr, &binfo, in_nfavl);
1375 	}
1376 
1377 	if (ret && ((sym = sr.sr_sym) != NULL)) {
1378 		Lm_list	*lml = LIST(clmp);
1379 		Addr	addr = sym->st_value;
1380 
1381 		*dlmp = sr.sr_dmap;
1382 		if (!(FLAGS(*dlmp) & FLG_RT_FIXED))
1383 			addr += ADDR(*dlmp);
1384 
1385 		/*
1386 		 * Indicate that the defining object is now used.
1387 		 */
1388 		if (*dlmp != clmp)
1389 			FLAGS1(*dlmp) |= FL1_RT_USED;
1390 
1391 		DBG_CALL(Dbg_bind_global(clmp, 0, 0, (Xword)-1, PLT_T_NONE,
1392 		    *dlmp, addr, sym->st_value, sr.sr_name, binfo));
1393 
1394 		if ((lml->lm_tflags | AFLAGS(clmp) | AFLAGS(*dlmp)) &
1395 		    LML_TFLG_AUD_SYMBIND) {
1396 			uint_t	sb_flags = LA_SYMB_DLSYM;
1397 			/* LINTED */
1398 			uint_t	symndx = (uint_t)(((Xword)sym -
1399 			    (Xword)SYMTAB(*dlmp)) / SYMENT(*dlmp));
1400 			addr = audit_symbind(clmp, *dlmp, sym, symndx, addr,
1401 			    &sb_flags);
1402 		}
1403 		return ((void *)addr);
1404 	}
1405 
1406 	return (NULL);
1407 }
1408 
1409 /*
1410  * Internal dlsym activity.  Called from user level or directly for internal
1411  * symbol lookup.
1412  */
1413 void *
dlsym_intn(void * handle,const char * name,Rt_map * clmp,Rt_map ** dlmp)1414 dlsym_intn(void *handle, const char *name, Rt_map *clmp, Rt_map **dlmp)
1415 {
1416 	Rt_map		*llmp = NULL;
1417 	void		*error;
1418 	Aliste		idx;
1419 	Grp_desc	*gdp;
1420 	int		in_nfavl = 0;
1421 
1422 	/*
1423 	 * While looking for symbols it's quite possible that additional objects
1424 	 * get loaded from lazy loading.  These objects will have been added to
1425 	 * the same link-map list as those objects on the handle.  Remember this
1426 	 * list for later investigation.
1427 	 */
1428 	if ((handle == RTLD_NEXT) || (handle == RTLD_DEFAULT) ||
1429 	    (handle == RTLD_SELF) || (handle == RTLD_PROBE))
1430 		llmp = LIST(clmp)->lm_tail;
1431 	else {
1432 		Grp_hdl	*ghp = (Grp_hdl *)handle;
1433 
1434 		if (ghp->gh_ownlmp)
1435 			llmp = LIST(ghp->gh_ownlmp)->lm_tail;
1436 		else {
1437 			for (ALIST_TRAVERSE(ghp->gh_depends, idx, gdp)) {
1438 				if ((llmp =
1439 				    LIST(gdp->gd_depend)->lm_tail) != NULL)
1440 					break;
1441 			}
1442 		}
1443 	}
1444 
1445 	error = dlsym_core(handle, name, clmp, dlmp, &in_nfavl);
1446 
1447 	/*
1448 	 * If the symbol could not be found it is possible that the "not-found"
1449 	 * AVL tree had indicated that a required file does not exist.  In case
1450 	 * the file system has changed since this "not-found" recording was
1451 	 * made, retry the dlsym() with a clean "not-found" AVL tree.
1452 	 */
1453 	if ((error == NULL) && in_nfavl) {
1454 		avl_tree_t	*oavlt = nfavl;
1455 
1456 		nfavl = NULL;
1457 		error = dlsym_core(handle, name, clmp, dlmp, NULL);
1458 
1459 		/*
1460 		 * If the symbol is found, then any file that was loaded will
1461 		 * have had its full path name registered in the FullPath AVL
1462 		 * tree.  Remove any new "not-found" AVL information, and
1463 		 * restore the former AVL tree.
1464 		 */
1465 		nfavl_remove(nfavl);
1466 		nfavl = oavlt;
1467 	}
1468 
1469 	if (error == NULL) {
1470 		/*
1471 		 * Cache the error message, as Java tends to fall through this
1472 		 * code many times.
1473 		 */
1474 		if (nosym_str == NULL)
1475 			nosym_str = MSG_INTL(MSG_GEN_NOSYM);
1476 		eprintf(LIST(clmp), ERR_FATAL, nosym_str, name);
1477 	}
1478 
1479 	load_completion(llmp);
1480 	return (error);
1481 }
1482 
1483 /*
1484  * Argument checking for dlsym.  Only called via external entry.
1485  */
1486 static void *
dlsym_check(void * handle,const char * name,Rt_map * clmp,Rt_map ** dlmp)1487 dlsym_check(void *handle, const char *name, Rt_map *clmp, Rt_map **dlmp)
1488 {
1489 	/*
1490 	 * Verify the arguments.
1491 	 */
1492 	if (name == NULL) {
1493 		eprintf(LIST(clmp), ERR_FATAL, MSG_INTL(MSG_ARG_ILLSYM));
1494 		return (NULL);
1495 	}
1496 	if ((handle != RTLD_NEXT) && (handle != RTLD_DEFAULT) &&
1497 	    (handle != RTLD_SELF) && (handle != RTLD_PROBE) &&
1498 	    (hdl_validate((Grp_hdl *)handle) == 0)) {
1499 		eprintf(LIST(clmp), ERR_FATAL, MSG_INTL(MSG_ARG_INVHNDL),
1500 		    EC_NATPTR(handle));
1501 		return (NULL);
1502 	}
1503 	return (dlsym_intn(handle, name, clmp, dlmp));
1504 }
1505 
1506 
1507 #pragma weak _dlsym = dlsym
1508 
1509 /*
1510  * External entry for dlsym().  On success, returns the address of the specified
1511  * symbol.  On error returns a null.
1512  */
1513 void *
dlsym(void * handle,const char * name)1514 dlsym(void *handle, const char *name)
1515 {
1516 	int	entry;
1517 	Rt_map	*clmp, *dlmp = NULL;
1518 	void	*addr;
1519 
1520 	entry = enter(0);
1521 
1522 	clmp = _caller(caller(), CL_EXECDEF);
1523 
1524 	addr = dlsym_check(handle, name, clmp, &dlmp);
1525 
1526 	if (entry) {
1527 		if (dlmp)
1528 			is_dep_init(dlmp, clmp);
1529 		leave(LIST(clmp), 0);
1530 	}
1531 	return (addr);
1532 }
1533 
1534 /*
1535  * Core dladdr activity.
1536  */
1537 static void
dladdr_core(Rt_map * almp,void * addr,Dl_info_t * dlip,void ** info,int flags)1538 dladdr_core(Rt_map *almp, void *addr, Dl_info_t *dlip, void **info, int flags)
1539 {
1540 	/*
1541 	 * Set up generic information and any defaults.
1542 	 */
1543 	dlip->dli_fname = PATHNAME(almp);
1544 
1545 	dlip->dli_fbase = (void *)ADDR(almp);
1546 	dlip->dli_sname = NULL;
1547 	dlip->dli_saddr = NULL;
1548 
1549 	/*
1550 	 * Determine the nearest symbol to this address.
1551 	 */
1552 	LM_DLADDR(almp)((ulong_t)addr, almp, dlip, info, flags);
1553 }
1554 
1555 #pragma weak _dladdr = dladdr
1556 
1557 /*
1558  * External entry for dladdr(3dl) and dladdr1(3dl).  Returns an information
1559  * structure that reflects the symbol closest to the address specified.
1560  */
1561 int
dladdr(void * addr,Dl_info_t * dlip)1562 dladdr(void *addr, Dl_info_t *dlip)
1563 {
1564 	int	entry, ret;
1565 	Rt_map	*clmp, *almp;
1566 	Lm_list	*clml;
1567 
1568 	entry = enter(0);
1569 
1570 	clmp = _caller(caller(), CL_EXECDEF);
1571 	clml = LIST(clmp);
1572 
1573 	DBG_CALL(Dbg_dl_dladdr(clmp, addr));
1574 
1575 	/*
1576 	 * Use our calling technique to determine what object is associated
1577 	 * with the supplied address.  If a caller can't be determined,
1578 	 * indicate the failure.
1579 	 */
1580 	if ((almp = _caller(addr, CL_NONE)) == NULL) {
1581 		eprintf(clml, ERR_FATAL, MSG_INTL(MSG_ARG_INVADDR),
1582 		    EC_NATPTR(addr));
1583 		ret = 0;
1584 	} else {
1585 		dladdr_core(almp, addr, dlip, 0, 0);
1586 		ret = 1;
1587 	}
1588 
1589 	if (entry)
1590 		leave(clml, 0);
1591 	return (ret);
1592 }
1593 
1594 #pragma weak _dladdr1 = dladdr1
1595 
1596 int
dladdr1(void * addr,Dl_info_t * dlip,void ** info,int flags)1597 dladdr1(void *addr, Dl_info_t *dlip, void **info, int flags)
1598 {
1599 	int	entry, ret = 1;
1600 	Rt_map	*clmp, *almp;
1601 	Lm_list	*clml;
1602 
1603 	entry = enter(0);
1604 
1605 	clmp = _caller(caller(), CL_EXECDEF);
1606 	clml = LIST(clmp);
1607 
1608 	DBG_CALL(Dbg_dl_dladdr(clmp, addr));
1609 
1610 	/*
1611 	 * Validate any flags.
1612 	 */
1613 	if (flags) {
1614 		int	request;
1615 
1616 		if (((request = (flags & RTLD_DL_MASK)) != RTLD_DL_SYMENT) &&
1617 		    (request != RTLD_DL_LINKMAP)) {
1618 			eprintf(clml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLFLAGS),
1619 			    flags);
1620 			ret = 0;
1621 
1622 		} else if (info == NULL) {
1623 			eprintf(clml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLINFO),
1624 			    flags);
1625 			ret = 0;
1626 		}
1627 	}
1628 
1629 	/*
1630 	 * Use our calling technique to determine what object is associated
1631 	 * with the supplied address.  If a caller can't be determined,
1632 	 * indicate the failure.
1633 	 */
1634 	if (ret) {
1635 		if ((almp = _caller(addr, CL_NONE)) == NULL) {
1636 			eprintf(clml, ERR_FATAL, MSG_INTL(MSG_ARG_INVADDR),
1637 			    EC_NATPTR(addr));
1638 			ret = 0;
1639 		} else
1640 			dladdr_core(almp, addr, dlip, info, flags);
1641 	}
1642 
1643 	if (entry)
1644 		leave(clml, 0);
1645 	return (ret);
1646 }
1647 
1648 /*
1649  * Core dldump activity.
1650  */
1651 static int
dldump_core(Rt_map * clmp,Rt_map * lmp,const char * ipath,const char * opath,int flags)1652 dldump_core(Rt_map *clmp, Rt_map *lmp, const char *ipath, const char *opath,
1653     int flags)
1654 {
1655 	Lm_list	*lml = LIST(clmp);
1656 	Addr	addr = 0;
1657 
1658 	/*
1659 	 * Verify any arguments first.
1660 	 */
1661 	if ((opath == NULL) || (opath[0] == '\0') ||
1662 	    ((lmp == NULL) && (ipath[0] == '\0'))) {
1663 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLPATH));
1664 		return (1);
1665 	}
1666 
1667 	/*
1668 	 * If an input file is specified make sure its one of our dependencies
1669 	 * on the main link-map list.  Note, this has really all evolved for
1670 	 * crle(), which uses libcrle.so on an alternative link-map to trigger
1671 	 * dumping objects from the main link-map list.   If we ever want to
1672 	 * dump objects from alternative link-maps, this model is going to
1673 	 * have to be revisited.
1674 	 */
1675 	if (lmp == NULL) {
1676 		if ((lmp = is_so_loaded(&lml_main, ipath, NULL)) == NULL) {
1677 			eprintf(lml, ERR_FATAL, MSG_INTL(MSG_GEN_NOFILE),
1678 			    ipath);
1679 			return (1);
1680 		}
1681 		if (FLAGS(lmp) & FLG_RT_ALTER) {
1682 			eprintf(lml, ERR_FATAL, MSG_INTL(MSG_GEN_ALTER), ipath);
1683 			return (1);
1684 		}
1685 		if (FLAGS(lmp) & FLG_RT_NODUMP) {
1686 			eprintf(lml, ERR_FATAL, MSG_INTL(MSG_GEN_NODUMP),
1687 			    ipath);
1688 			return (1);
1689 		}
1690 	}
1691 
1692 	/*
1693 	 * If the object being dump'ed isn't fixed identify its mapping.
1694 	 */
1695 	if (!(FLAGS(lmp) & FLG_RT_FIXED))
1696 		addr = ADDR(lmp);
1697 
1698 	/*
1699 	 * As rt_dldump() will effectively lazy load the necessary support
1700 	 * libraries, make sure ld.so.1 is initialized for plt relocations.
1701 	 */
1702 	if (elf_rtld_load() == 0)
1703 		return (0);
1704 
1705 	/*
1706 	 * Dump the required image.
1707 	 */
1708 	return (rt_dldump(lmp, opath, flags, addr));
1709 }
1710 
1711 #pragma weak _dldump = dldump
1712 
1713 /*
1714  * External entry for dldump(3c).  Returns 0 on success, non-zero otherwise.
1715  */
1716 int
dldump(const char * ipath,const char * opath,int flags)1717 dldump(const char *ipath, const char *opath, int flags)
1718 {
1719 	int	error, entry;
1720 	Rt_map	*clmp, *lmp;
1721 
1722 	entry = enter(0);
1723 
1724 	clmp = _caller(caller(), CL_EXECDEF);
1725 
1726 	if (ipath) {
1727 		lmp = NULL;
1728 	} else {
1729 		lmp = lml_main.lm_head;
1730 		ipath = NAME(lmp);
1731 	}
1732 
1733 	DBG_CALL(Dbg_dl_dldump(clmp, ipath, opath, flags));
1734 
1735 	error = dldump_core(clmp, lmp, ipath, opath, flags);
1736 
1737 	if (entry)
1738 		leave(LIST(clmp), 0);
1739 	return (error);
1740 }
1741 
1742 /*
1743  * get_linkmap_id() translates Lm_list * pointers to the Link_map id as used by
1744  * the rtld_db and dlmopen() interfaces.  It checks to see if the Link_map is
1745  * one of the primary ones and if so returns it's special token:
1746  *		LM_ID_BASE
1747  *		LM_ID_LDSO
1748  *
1749  * If it's not one of the primary link_map id's it will instead returns a
1750  * pointer to the Lm_list structure which uniquely identifies the Link_map.
1751  */
1752 Lmid_t
get_linkmap_id(Lm_list * lml)1753 get_linkmap_id(Lm_list *lml)
1754 {
1755 	if (lml->lm_flags & LML_FLG_BASELM)
1756 		return (LM_ID_BASE);
1757 	if (lml->lm_flags & LML_FLG_RTLDLM)
1758 		return (LM_ID_LDSO);
1759 
1760 	return ((Lmid_t)lml);
1761 }
1762 
1763 /*
1764  * Set a new deferred dependency name.
1765  */
1766 static int
set_def_need(Lm_list * lml,Dyninfo * dyip,const char * name)1767 set_def_need(Lm_list *lml, Dyninfo *dyip, const char *name)
1768 {
1769 	/*
1770 	 * If this dependency has already been established, then this dlinfo()
1771 	 * call is too late.
1772 	 */
1773 	if (dyip->di_info) {
1774 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_DEF_DEPLOADED),
1775 		    dyip->di_name);
1776 		return (-1);
1777 	}
1778 
1779 	/*
1780 	 * Assign the new dependency name.
1781 	 */
1782 	DBG_CALL(Dbg_file_deferred(lml, dyip->di_name, name));
1783 	dyip->di_flags |= FLG_DI_DEF_DONE;
1784 	dyip->di_name = name;
1785 	return (0);
1786 }
1787 
1788 /*
1789  * Extract information for a dlopen() handle.
1790  */
1791 static int
dlinfo_core(void * handle,int request,void * p,Rt_map * clmp)1792 dlinfo_core(void *handle, int request, void *p, Rt_map *clmp)
1793 {
1794 	Conv_inv_buf_t	inv_buf;
1795 	char		*handlename;
1796 	Lm_list		*lml = LIST(clmp);
1797 	Rt_map		*lmp = NULL;
1798 
1799 	/*
1800 	 * Determine whether a handle is provided.  A handle isn't needed for
1801 	 * all operations, but it is validated here for the initial diagnostic.
1802 	 */
1803 	if (handle == RTLD_SELF) {
1804 		lmp = clmp;
1805 	} else {
1806 		Grp_hdl	*ghp = (Grp_hdl *)handle;
1807 
1808 		if (hdl_validate(ghp))
1809 			lmp = ghp->gh_ownlmp;
1810 	}
1811 	if (lmp) {
1812 		handlename = NAME(lmp);
1813 	} else {
1814 		(void) conv_invalid_val(&inv_buf, EC_NATPTR(handle), 0);
1815 		handlename = inv_buf.buf;
1816 	}
1817 
1818 	DBG_CALL(Dbg_dl_dlinfo(clmp, handlename, request, p));
1819 
1820 	/*
1821 	 * Validate the request and return buffer.
1822 	 */
1823 	if ((request > RTLD_DI_MAX) || (p == NULL)) {
1824 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLVAL));
1825 		return (-1);
1826 	}
1827 
1828 	/*
1829 	 * Return configuration cache name and address.
1830 	 */
1831 	if (request == RTLD_DI_CONFIGADDR) {
1832 		Dl_info_t	*dlip = (Dl_info_t *)p;
1833 
1834 		if ((config->c_name == NULL) || (config->c_bgn == 0) ||
1835 		    (config->c_end == 0)) {
1836 			eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_NOCONFIG));
1837 			return (-1);
1838 		}
1839 		dlip->dli_fname = config->c_name;
1840 		dlip->dli_fbase = (void *)config->c_bgn;
1841 		return (0);
1842 	}
1843 
1844 	/*
1845 	 * Return profiled object name (used by ldprof audit library).
1846 	 */
1847 	if (request == RTLD_DI_PROFILENAME) {
1848 		if (profile_name == NULL) {
1849 			eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_NOPROFNAME));
1850 			return (-1);
1851 		}
1852 
1853 		*(const char **)p = profile_name;
1854 		return (0);
1855 	}
1856 	if (request == RTLD_DI_PROFILEOUT) {
1857 		/*
1858 		 * If a profile destination directory hasn't been specified
1859 		 * provide a default.
1860 		 */
1861 		if (profile_out == NULL)
1862 			profile_out = MSG_ORIG(MSG_PTH_VARTMP);
1863 
1864 		*(const char **)p = profile_out;
1865 		return (0);
1866 	}
1867 
1868 	/*
1869 	 * Obtain or establish a termination signal.
1870 	 */
1871 	if (request == RTLD_DI_GETSIGNAL) {
1872 		*(int *)p = killsig;
1873 		return (0);
1874 	}
1875 
1876 	if (request == RTLD_DI_SETSIGNAL) {
1877 		sigset_t	set;
1878 		int		sig = *(int *)p;
1879 
1880 		/*
1881 		 * Determine whether the signal is in range.
1882 		 */
1883 		(void) sigfillset(&set);
1884 		if (sigismember(&set, sig) != 1) {
1885 			eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_INVSIG), sig);
1886 			return (-1);
1887 		}
1888 
1889 		killsig = sig;
1890 		return (0);
1891 	}
1892 
1893 	/*
1894 	 * For any other request a link-map is required.  Verify the handle.
1895 	 */
1896 	if (lmp == NULL) {
1897 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_INVHNDL),
1898 		    EC_NATPTR(handle));
1899 		return (-1);
1900 	}
1901 
1902 	/*
1903 	 * Obtain the process arguments, environment and auxv.  Note, as the
1904 	 * environment can be modified by the user (putenv(3c)), reinitialize
1905 	 * the environment pointer on each request.
1906 	 */
1907 	if (request == RTLD_DI_ARGSINFO) {
1908 		Dl_argsinfo_t	*aip = (Dl_argsinfo_t *)p;
1909 		Lm_list		*lml = LIST(lmp);
1910 
1911 		*aip = argsinfo;
1912 		if (lml->lm_flags & LML_FLG_ENVIRON)
1913 			aip->dla_envp = *(lml->lm_environ);
1914 
1915 		return (0);
1916 	}
1917 
1918 	/*
1919 	 * Return Lmid_t of the Link-Map list that the specified object is
1920 	 * loaded on.
1921 	 */
1922 	if (request == RTLD_DI_LMID) {
1923 		*(Lmid_t *)p = get_linkmap_id(LIST(lmp));
1924 		return (0);
1925 	}
1926 
1927 	/*
1928 	 * Return a pointer to the Link-Map structure associated with the
1929 	 * specified object.
1930 	 */
1931 	if (request == RTLD_DI_LINKMAP) {
1932 		*(Link_map **)p = (Link_map *)lmp;
1933 		return (0);
1934 	}
1935 
1936 	/*
1937 	 * Return search path information, or the size of the buffer required
1938 	 * to store the information.
1939 	 */
1940 	if ((request == RTLD_DI_SERINFO) || (request == RTLD_DI_SERINFOSIZE)) {
1941 		Spath_desc	sd = { search_rules, NULL, 0 };
1942 		Pdesc		*pdp;
1943 		Dl_serinfo_t	*info;
1944 		Dl_serpath_t	*path;
1945 		char		*strs;
1946 		size_t		size = sizeof (Dl_serinfo_t);
1947 		uint_t		cnt = 0;
1948 
1949 		info = (Dl_serinfo_t *)p;
1950 		path = &info->dls_serpath[0];
1951 		strs = (char *)&info->dls_serpath[info->dls_cnt];
1952 
1953 		/*
1954 		 * Traverse search path entries for this object.
1955 		 */
1956 		while ((pdp = get_next_dir(&sd, lmp, 0)) != NULL) {
1957 			size_t	_size;
1958 
1959 			if (pdp->pd_pname == NULL)
1960 				continue;
1961 
1962 			/*
1963 			 * If configuration information exists, it's possible
1964 			 * this path has been identified as non-existent, if so
1965 			 * ignore it.
1966 			 */
1967 			if (pdp->pd_info) {
1968 				Rtc_obj	*dobj = (Rtc_obj *)pdp->pd_info;
1969 				if (dobj->co_flags & RTC_OBJ_NOEXIST)
1970 					continue;
1971 			}
1972 
1973 			/*
1974 			 * Keep track of search path count and total info size.
1975 			 */
1976 			if (cnt++)
1977 				size += sizeof (Dl_serpath_t);
1978 			_size = pdp->pd_plen + 1;
1979 			size += _size;
1980 
1981 			if (request == RTLD_DI_SERINFOSIZE)
1982 				continue;
1983 
1984 			/*
1985 			 * If we're filling in search path information, confirm
1986 			 * there's sufficient space.
1987 			 */
1988 			if (size > info->dls_size) {
1989 				eprintf(lml, ERR_FATAL,
1990 				    MSG_INTL(MSG_ARG_SERSIZE),
1991 				    EC_OFF(info->dls_size));
1992 				return (-1);
1993 			}
1994 			if (cnt > info->dls_cnt) {
1995 				eprintf(lml, ERR_FATAL,
1996 				    MSG_INTL(MSG_ARG_SERCNT), info->dls_cnt);
1997 				return (-1);
1998 			}
1999 
2000 			/*
2001 			 * Append the path to the information buffer.
2002 			 */
2003 			(void) strcpy(strs, pdp->pd_pname);
2004 			path->dls_name = strs;
2005 			path->dls_flags = (pdp->pd_flags & LA_SER_MASK);
2006 
2007 			strs = strs + _size;
2008 			path++;
2009 		}
2010 
2011 		/*
2012 		 * If we're here to size the search buffer fill it in.
2013 		 */
2014 		if (request == RTLD_DI_SERINFOSIZE) {
2015 			info->dls_size = size;
2016 			info->dls_cnt = cnt;
2017 		}
2018 
2019 		return (0);
2020 	}
2021 
2022 	/*
2023 	 * Return the origin of the object associated with this link-map.
2024 	 * Basically return the dirname(1) of the objects fullpath.
2025 	 */
2026 	if (request == RTLD_DI_ORIGIN) {
2027 		char	*str = (char *)p;
2028 
2029 		(void) strncpy(str, ORIGNAME(lmp), DIRSZ(lmp));
2030 		str += DIRSZ(lmp);
2031 		*str = '\0';
2032 
2033 		return (0);
2034 	}
2035 
2036 	/*
2037 	 * Return the number of object mappings, or the mapping information for
2038 	 * this object.
2039 	 */
2040 	if (request == RTLD_DI_MMAPCNT) {
2041 		uint_t	*cnt = (uint_t *)p;
2042 
2043 		*cnt = MMAPCNT(lmp);
2044 		return (0);
2045 	}
2046 	if (request == RTLD_DI_MMAPS) {
2047 		Dl_mapinfo_t	*mip = (Dl_mapinfo_t *)p;
2048 
2049 		if (mip->dlm_acnt && mip->dlm_maps) {
2050 			uint_t	cnt = 0;
2051 
2052 			while ((cnt < mip->dlm_acnt) && (cnt < MMAPCNT(lmp))) {
2053 				mip->dlm_maps[cnt] = MMAPS(lmp)[cnt];
2054 				cnt++;
2055 			}
2056 			mip->dlm_rcnt = cnt;
2057 		}
2058 		return (0);
2059 	}
2060 
2061 	/*
2062 	 * Assign a new dependency name to a deferred dependency.
2063 	 */
2064 	if ((request == RTLD_DI_DEFERRED) ||
2065 	    (request == RTLD_DI_DEFERRED_SYM)) {
2066 		Dl_definfo_t	*dfip = (Dl_definfo_t *)p;
2067 		Dyninfo		*dyip;
2068 		const char	*dname, *rname;
2069 
2070 		/*
2071 		 * Verify the names.
2072 		 */
2073 		if ((dfip->dld_refname == NULL) ||
2074 		    (dfip->dld_depname == NULL)) {
2075 			eprintf(LIST(clmp), ERR_FATAL,
2076 			    MSG_INTL(MSG_ARG_ILLNAME));
2077 			return (-1);
2078 		}
2079 
2080 		dname = dfip->dld_depname;
2081 		rname = dfip->dld_refname;
2082 
2083 		/*
2084 		 * A deferred dependency can be determined by referencing a
2085 		 * symbol family member that is associated to the dependency,
2086 		 * or by looking for the dependency by its name.
2087 		 */
2088 		if (request == RTLD_DI_DEFERRED_SYM) {
2089 			Slookup		sl;
2090 			Sresult		sr;
2091 			uint_t		binfo;
2092 			Syminfo		*sip;
2093 
2094 			/*
2095 			 * Lookup the symbol in the associated object.
2096 			 */
2097 			SLOOKUP_INIT(sl, rname, lmp, lmp, ld_entry_cnt,
2098 			    elf_hash(rname), 0, 0, 0, LKUP_SYMNDX);
2099 			SRESULT_INIT(sr, rname);
2100 			if (sym_lookup_in_caller(clmp, &sl, &sr,
2101 			    &binfo) == NULL) {
2102 				eprintf(LIST(clmp), ERR_FATAL,
2103 				    MSG_INTL(MSG_DEF_NOSYMFOUND), rname);
2104 				return (-1);
2105 			}
2106 
2107 			/*
2108 			 * Use the symbols index to reference the Syminfo entry
2109 			 * and thus find the associated dependency.
2110 			 */
2111 			if (sl.sl_rsymndx && ((sip = SYMINFO(clmp)) != NULL)) {
2112 				/* LINTED */
2113 				sip = (Syminfo *)((char *)sip +
2114 				    (sl.sl_rsymndx * SYMINENT(lmp)));
2115 
2116 				if ((sip->si_flags & SYMINFO_FLG_DEFERRED) &&
2117 				    (sip->si_boundto < SYMINFO_BT_LOWRESERVE) &&
2118 				    ((dyip = DYNINFO(lmp)) != NULL)) {
2119 					dyip += sip->si_boundto;
2120 
2121 					if (!(dyip->di_flags & FLG_DI_IGNORE))
2122 						return (set_def_need(lml,
2123 						    dyip, dname));
2124 				}
2125 			}
2126 
2127 			/*
2128 			 * No deferred symbol found.
2129 			 */
2130 			eprintf(LIST(clmp), ERR_FATAL,
2131 			    MSG_INTL(MSG_DEF_NOSYMFOUND), rname);
2132 			return (-1);
2133 
2134 		} else {
2135 			Dyn	*dyn;
2136 
2137 			/*
2138 			 * Using the target objects dependency information, find
2139 			 * the associated deferred dependency.
2140 			 */
2141 			for (dyn = DYN(lmp), dyip = DYNINFO(lmp);
2142 			    !(dyip->di_flags & FLG_DI_IGNORE); dyn++, dyip++) {
2143 				const char	*oname;
2144 
2145 				if ((dyip->di_flags & FLG_DI_DEFERRED) == 0)
2146 					continue;
2147 
2148 				if (strcmp(rname, dyip->di_name) == 0)
2149 					return (set_def_need(lml, dyip, dname));
2150 
2151 				/*
2152 				 * If this dependency name has been changed by
2153 				 * a previous dlinfo(), check the original
2154 				 * dynamic entry string.  The user might be
2155 				 * attempting to re-change an entry using the
2156 				 * original name as the reference.
2157 				 */
2158 				if ((dyip->di_flags & FLG_DI_DEF_DONE) == 0)
2159 					continue;
2160 
2161 				oname = STRTAB(lmp) + dyn->d_un.d_val;
2162 				if (strcmp(rname, oname) == 0)
2163 					return (set_def_need(lml, dyip, dname));
2164 			}
2165 
2166 			/*
2167 			 * No deferred dependency found.
2168 			 */
2169 			eprintf(lml, ERR_FATAL, MSG_INTL(MSG_DEF_NODEPFOUND),
2170 			    rname);
2171 			return (-1);
2172 		}
2173 	}
2174 	return (0);
2175 }
2176 
2177 #pragma weak _dlinfo = dlinfo
2178 
2179 /*
2180  * External entry for dlinfo(3dl).
2181  */
2182 int
dlinfo(void * handle,int request,void * p)2183 dlinfo(void *handle, int request, void *p)
2184 {
2185 	int	error, entry;
2186 	Rt_map	*clmp;
2187 
2188 	entry = enter(0);
2189 
2190 	clmp = _caller(caller(), CL_EXECDEF);
2191 
2192 	error = dlinfo_core(handle, request, p, clmp);
2193 
2194 	if (entry)
2195 		leave(LIST(clmp), 0);
2196 	return (error);
2197 }
2198 
2199 /*
2200  * GNU defined function to iterate through the program headers for all
2201  * currently loaded dynamic objects. The caller supplies a callback function
2202  * which is called for each object.
2203  *
2204  * entry:
2205  *	callback - Callback function to call. The arguments to the callback
2206  *		function are:
2207  *		info - Address of dl_phdr_info structure
2208  *		size - sizeof (struct dl_phdr_info)
2209  *		data - Caller supplied value.
2210  *	data - Value supplied by caller, which is passed to callback without
2211  *		examination.
2212  *
2213  * exit:
2214  *	callback is called for each dynamic ELF object in the process address
2215  *	space, halting when a non-zero value is returned, or when the last
2216  *	object has been processed. The return value from the last call
2217  *	to callback is returned.
2218  *
2219  * note:
2220  *	The Linux implementation has added additional fields to the
2221  *	dl_phdr_info structure over time. The callback function is
2222  *	supposed to use the size field to determine which fields are
2223  *	present, and to avoid attempts to access non-existent fields.
2224  *	We have added those fields that are compatible with Solaris, and
2225  *	which are used by GNU C++ (g++) runtime exception handling support.
2226  *
2227  * note:
2228  *	We issue a callback for every ELF object mapped into the process
2229  *	address space at the time this routine is entered. These callbacks
2230  *	are arbitrary functions that can do anything, including possibly
2231  *	causing new objects to be mapped into the process, or unmapped.
2232  *	This complicates matters:
2233  *
2234  *	-	Adding new objects can cause the alists to be reallocated
2235  *		or for contents to move. This can happen explicitly via
2236  *		dlopen(), or implicitly via lazy loading. One might consider
2237  *		simply banning dlopen from a callback, but lazy loading must
2238  *		be allowed, in which case there's no reason to ban dlopen().
2239  *
2240  *	-	Removing objects can leave us holding references to freed
2241  *		memory that must not be accessed, and can cause the list
2242  *		items to move in a way that would cause us to miss reporting
2243  *		one, or double report others.
2244  *
2245  *	-	We cannot allocate memory to build a separate data structure,
2246  *		because the interface to dl_iterate_phdr() does not have a
2247  *		way to communicate allocation errors back to the caller.
2248  *		Even if we could, it would be difficult to do so efficiently.
2249  *
2250  *	-	It is possible for dl_iterate_phdr() to be called recursively
2251  *		from a callback, and there is no way for us to detect or manage
2252  *		this effectively, particularly as the user might use longjmp()
2253  *		to skip past us on return. Hence, we must be reentrant
2254  *		(stateless), further precluding the option of building a
2255  *		separate data structure.
2256  *
2257  *	Despite these constraints, we are able to traverse the link-map
2258  *	lists safely:
2259  *
2260  *	-	Once interposer (preload) objects have been processed at
2261  *		startup, we know that new objects are always placed at the
2262  *		end of the list. Hence, if we are reading a list when that
2263  *		happens, the new object will not alter the part of the list
2264  *		that we've already processed.
2265  *
2266  *	-	The alist _TRAVERSE macros recalculate the address of the
2267  *		current item from scratch on each iteration, rather than
2268  *		incrementing a pointer. Hence, alist additions that occur
2269  *		in mid-traverse will not cause confusion.
2270  *
2271  *	There is one limitation: We cannot continue operation if an object
2272  *	is removed from the process from within a callback. We detect when
2273  *	this happens and return immediately with a -1 return value.
2274  *
2275  * note:
2276  *	As currently implemented, if a callback causes an object to be loaded,
2277  *	that object may or may not be reported by the current invocation of
2278  *	dl_iterate_phdr(), based on whether or not we have already processed
2279  *	the link-map list that receives it. If we want to prevent this, it
2280  *	can be done efficiently by associating the current value of cnt_map
2281  *	with each new Rt_map entered into the system. Then this function can
2282  *	use that to detect and skip new objects that enter the system in
2283  *	mid-iteration. However, the Linux documentation is ambiguous on whether
2284  *	this is necessary, and it does not appear to matter in practice.
2285  *	We have therefore chosen not to do so at this time.
2286  */
2287 int
dl_iterate_phdr(int (* callback)(struct dl_phdr_info *,size_t,void *),void * data)2288 dl_iterate_phdr(int (*callback)(struct dl_phdr_info *, size_t, void *),
2289     void *data)
2290 {
2291 	struct dl_phdr_info	info;
2292 	u_longlong_t		l_cnt_map = cnt_map;
2293 	u_longlong_t		l_cnt_unmap = cnt_unmap;
2294 	Lm_list			*lml, *clml;
2295 	Lm_cntl			*lmc;
2296 	Rt_map			*lmp, *clmp;
2297 	Aliste			idx1, idx2;
2298 	Ehdr			*ehdr;
2299 	int			ret = 0;
2300 	int			entry;
2301 
2302 	entry = enter(0);
2303 	clmp = _caller(caller(), CL_EXECDEF);
2304 	clml = LIST(clmp);
2305 
2306 	DBG_CALL(Dbg_dl_iphdr_enter(clmp, cnt_map, cnt_unmap));
2307 
2308 	/* Issue a callback for each ELF object in the process */
2309 	for (APLIST_TRAVERSE(dynlm_list, idx1, lml)) {
2310 		for (ALIST_TRAVERSE(lml->lm_lists, idx2, lmc)) {
2311 			for (lmp = lmc->lc_head; lmp; lmp = NEXT_RT_MAP(lmp)) {
2312 #if defined(_sparc) && !defined(_LP64)
2313 				/*
2314 				 * On 32-bit sparc, the possibility exists that
2315 				 * this object is not ELF.
2316 				 */
2317 				if (THIS_IS_NOT_ELF(lmp))
2318 					continue;
2319 #endif
2320 				/* Prepare the object information structure */
2321 				ehdr = (Ehdr *) ADDR(lmp);
2322 				info.dlpi_addr = (ehdr->e_type == ET_EXEC) ?
2323 				    0 : ADDR(lmp);
2324 				info.dlpi_name = lmp->rt_pathname;
2325 				info.dlpi_phdr = (Phdr *)
2326 				    (ADDR(lmp) + ehdr->e_phoff);
2327 				info.dlpi_phnum = ehdr->e_phnum;
2328 				info.dlpi_adds = cnt_map;
2329 				info.dlpi_subs = cnt_unmap;
2330 
2331 				/* Issue the callback */
2332 				DBG_CALL(Dbg_dl_iphdr_callback(clml, &info));
2333 				leave(clml, thr_flg_reenter);
2334 				ret = (* callback)(&info, sizeof (info), data);
2335 				(void) enter(thr_flg_reenter);
2336 
2337 				/* Return immediately on non-zero result */
2338 				if (ret != 0)
2339 					goto done;
2340 
2341 				/* Adapt to object mapping changes */
2342 				if ((cnt_map == l_cnt_map) &&
2343 				    (cnt_unmap == l_cnt_unmap))
2344 					continue;
2345 
2346 				DBG_CALL(Dbg_dl_iphdr_mapchange(clml, cnt_map,
2347 				    cnt_unmap));
2348 
2349 				/* Stop if an object was unmapped */
2350 				if (cnt_unmap == l_cnt_unmap) {
2351 					l_cnt_map = cnt_map;
2352 					continue;
2353 				}
2354 
2355 				ret = -1;
2356 				DBG_CALL(Dbg_dl_iphdr_unmap_ret(clml));
2357 				goto done;
2358 			}
2359 		}
2360 	}
2361 
2362 done:
2363 	if (entry)
2364 		leave(LIST(clmp), 0);
2365 	return (ret);
2366 }
2367