xref: /titanic_50/usr/src/cmd/sgs/rtld/common/dlfcns.c (revision a307732568c3d861c38b0342ae32434226d10e94)
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  */
28 
29 /*
30  * Programmatic interface to the run_time linker.
31  */
32 
33 #include	<sys/debug.h>
34 #include	<stdio.h>
35 #include	<string.h>
36 #include	<dlfcn.h>
37 #include	<synch.h>
38 #include	<limits.h>
39 #include	<debug.h>
40 #include	<conv.h>
41 #include	"_rtld.h"
42 #include	"_audit.h"
43 #include	"_elf.h"
44 #include	"_inline_gen.h"
45 #include	"msg.h"
46 
47 /*
48  * Determine who called us - given a pc determine in which object it resides.
49  *
50  * For dlopen() the link map of the caller must be passed to load_so() so that
51  * the appropriate search rules (4.x or 5.0) are used to locate any
52  * dependencies.  Also, if we've been called from a 4.x module it may be
53  * necessary to fix the specified pathname so that it conforms with the 5.0 elf
54  * rules.
55  *
56  * For dlsym() the link map of the caller is used to determine RTLD_NEXT
57  * requests, together with requests based off of a dlopen(0).
58  * For dladdr() this routines provides a generic means of scanning all loaded
59  * segments.
60  */
61 Rt_map *
62 _caller(caddr_t cpc, int flags)
63 {
64 	Lm_list	*lml;
65 	Aliste	idx1;
66 
67 	for (APLIST_TRAVERSE(dynlm_list, idx1, lml)) {
68 		Aliste	idx2;
69 		Lm_cntl	*lmc;
70 
71 		for (ALIST_TRAVERSE(lml->lm_lists, idx2, lmc)) {
72 			Rt_map	*lmp;
73 
74 			for (lmp = lmc->lc_head; lmp;
75 			    lmp = NEXT_RT_MAP(lmp)) {
76 
77 				if (find_segment(cpc, lmp))
78 					return (lmp);
79 			}
80 		}
81 	}
82 
83 	/*
84 	 * No mapping can be determined.  If asked for a default, assume this
85 	 * is from the executable.
86 	 */
87 	if (flags & CL_EXECDEF)
88 		return ((Rt_map *)lml_main.lm_head);
89 
90 	return (0);
91 }
92 
93 #pragma weak _dlerror = dlerror
94 
95 /*
96  * External entry for dlerror(3dl).  Returns a pointer to the string describing
97  * the last occurring error.  The last occurring error is cleared.
98  */
99 char *
100 dlerror()
101 {
102 	char	*error;
103 	Rt_map	*clmp;
104 	int	entry;
105 
106 	entry = enter(0);
107 
108 	clmp = _caller(caller(), CL_EXECDEF);
109 
110 	DBG_CALL(Dbg_dl_dlerror(clmp, lasterr));
111 
112 	error = lasterr;
113 	lasterr = NULL;
114 
115 	if (entry)
116 		leave(LIST(clmp), 0);
117 	return (error);
118 }
119 
120 /*
121  * Add a dependency as a group descriptor to a group handle.  Returns 0 on
122  * failure.  On success, returns the group descriptor, and if alep is non-NULL
123  * the *alep is set to ALE_EXISTS if the dependency already exists, or to
124  * ALE_CREATE if the dependency is newly created.
125  */
126 Grp_desc *
127 hdl_add(Grp_hdl *ghp, Rt_map *lmp, uint_t dflags, int *alep)
128 {
129 	Grp_desc	*gdp;
130 	Aliste		idx;
131 	int		ale = ALE_CREATE;
132 	uint_t		oflags;
133 
134 	/*
135 	 * Make sure this dependency hasn't already been recorded.
136 	 */
137 	for (ALIST_TRAVERSE(ghp->gh_depends, idx, gdp)) {
138 		if (gdp->gd_depend == lmp) {
139 			ale = ALE_EXISTS;
140 			break;
141 		}
142 	}
143 
144 	if (ale == ALE_CREATE) {
145 		Grp_desc	gd;
146 
147 		/*
148 		 * Create a new handle descriptor.
149 		 */
150 		gd.gd_depend = lmp;
151 		gd.gd_flags = 0;
152 
153 		/*
154 		 * Indicate this object is a part of this handles group.
155 		 */
156 		if (aplist_append(&GROUPS(lmp), ghp, AL_CNT_GROUPS) == NULL)
157 			return (NULL);
158 
159 		/*
160 		 * Append the new dependency to this handle.
161 		 */
162 		if ((gdp = alist_append(&ghp->gh_depends, &gd,
163 		    sizeof (Grp_desc), AL_CNT_DEPENDS)) == NULL)
164 			return (NULL);
165 	}
166 
167 	oflags = gdp->gd_flags;
168 	gdp->gd_flags |= dflags;
169 
170 	if (DBG_ENABLED) {
171 		if (ale == ALE_CREATE)
172 			DBG_CALL(Dbg_file_hdl_action(ghp, lmp, DBG_DEP_ADD,
173 			    gdp->gd_flags));
174 		else if (gdp->gd_flags != oflags)
175 			DBG_CALL(Dbg_file_hdl_action(ghp, lmp, DBG_DEP_UPDATE,
176 			    gdp->gd_flags));
177 	}
178 
179 	if (alep)
180 		*alep = ale;
181 	return (gdp);
182 }
183 
184 /*
185  * Create a handle.
186  *
187  *   rlmp -	represents the reference link-map for which the handle is being
188  *		created.
189  *   clmp -	represents the caller who is requesting the handle.
190  *   hflags -	provide group handle flags (GPH_*) that affect the use of the
191  *		handle, such as dlopen(0), or use or use of RTLD_FIRST.
192  *   rdflags -	provide group dependency flags for the reference link-map rlmp,
193  *		such as whether the dependency can be used for dlsym(), can be
194  *		relocated against, or whether this objects dependencies should
195  *		be processed.
196  *   cdflags -	provide group dependency flags for the caller.
197  */
198 Grp_hdl *
199 hdl_create(Lm_list *lml, Rt_map *rlmp, Rt_map *clmp, uint_t hflags,
200     uint_t rdflags, uint_t cdflags)
201 {
202 	Grp_hdl	*ghp = NULL, *aghp;
203 	APlist	**alpp;
204 	Aliste	idx;
205 
206 	/*
207 	 * For dlopen(0) the handle is maintained as part of the link-map list,
208 	 * otherwise the handle is associated with the reference link-map.
209 	 */
210 	if (hflags & GPH_ZERO)
211 		alpp = &(lml->lm_handle);
212 	else
213 		alpp = &(HANDLES(rlmp));
214 
215 	/*
216 	 * Objects can contain multiple handles depending on the handle flags
217 	 * supplied.  Most RTLD flags pertain to the object itself and the
218 	 * bindings that it can achieve.  Multiple handles for these flags
219 	 * don't make sense.  But if the flag determines how the handle might
220 	 * be used, then multiple handles may exist.  Presently this only makes
221 	 * sense for RTLD_FIRST.  Determine if an appropriate handle already
222 	 * exists.
223 	 */
224 	for (APLIST_TRAVERSE(*alpp, idx, aghp)) {
225 		if ((aghp->gh_flags & GPH_FIRST) == (hflags & GPH_FIRST)) {
226 			ghp = aghp;
227 			break;
228 		}
229 	}
230 
231 	if (ghp == NULL) {
232 		uint_t	ndx;
233 
234 		/*
235 		 * If this is the first request for this handle, allocate and
236 		 * initialize a new handle.
237 		 */
238 		DBG_CALL(Dbg_file_hdl_title(DBG_HDL_CREATE));
239 
240 		if ((ghp = malloc(sizeof (Grp_hdl))) == NULL)
241 			return (NULL);
242 
243 		/*
244 		 * Associate the handle with the link-map list or the reference
245 		 * link-map as appropriate.
246 		 */
247 		if (aplist_append(alpp, ghp, AL_CNT_GROUPS) == NULL) {
248 			free(ghp);
249 			return (NULL);
250 		}
251 
252 		/*
253 		 * Record the existence of this handle for future verification.
254 		 */
255 		/* LINTED */
256 		ndx = (uintptr_t)ghp % HDLIST_SZ;
257 
258 		if (aplist_append(&hdl_alp[ndx], ghp, AL_CNT_HANDLES) == NULL) {
259 			(void) aplist_delete_value(*alpp, ghp);
260 			free(ghp);
261 			return (NULL);
262 		}
263 
264 		ghp->gh_depends = NULL;
265 		ghp->gh_refcnt = 1;
266 		ghp->gh_flags = hflags;
267 
268 		/*
269 		 * A dlopen(0) handle is identified by the GPH_ZERO flag, the
270 		 * head of the link-map list is defined as the owner.  There is
271 		 * no need to maintain a list of dependencies, for when this
272 		 * handle is used (for dlsym()) a dynamic search through the
273 		 * entire link-map list provides for searching all objects with
274 		 * GLOBAL visibility.
275 		 */
276 		if (hflags & GPH_ZERO) {
277 			ghp->gh_ownlmp = lml->lm_head;
278 			ghp->gh_ownlml = lml;
279 		} else {
280 			ghp->gh_ownlmp = rlmp;
281 			ghp->gh_ownlml = LIST(rlmp);
282 
283 			if (hdl_add(ghp, rlmp, rdflags, NULL) == NULL)
284 				return (NULL);
285 
286 			/*
287 			 * If this new handle is a private handle, there's no
288 			 * need to track the caller, so we're done.
289 			 */
290 			if (hflags & GPH_PRIVATE)
291 				return (ghp);
292 
293 			/*
294 			 * If this new handle is public, and isn't a special
295 			 * handle representing ld.so.1, indicate that a local
296 			 * group now exists.  This state allows singleton
297 			 * searches to be optimized.
298 			 */
299 			if ((hflags & GPH_LDSO) == 0)
300 				LIST(rlmp)->lm_flags |= LML_FLG_GROUPSEXIST;
301 		}
302 	} else {
303 		/*
304 		 * If a handle already exists, bump its reference count.
305 		 *
306 		 * If the previous reference count was 0, then this is a handle
307 		 * that an earlier call to dlclose() was unable to remove.  Such
308 		 * handles are put on the orphan list.  As this handle is back
309 		 * in use, it must be removed from the orphan list.
310 		 *
311 		 * Note, handles associated with a link-map list itself (i.e.
312 		 * dlopen(0)) can have a reference count of 0.  However, these
313 		 * handles are never deleted, and therefore are never moved to
314 		 * the orphan list.
315 		 */
316 		if ((ghp->gh_refcnt++ == 0) &&
317 		    ((ghp->gh_flags & GPH_ZERO) == 0)) {
318 			uint_t	ndx;
319 
320 			/* LINTED */
321 			ndx = (uintptr_t)ghp % HDLIST_SZ;
322 
323 			(void) aplist_delete_value(hdl_alp[HDLIST_ORP], ghp);
324 			(void) aplist_append(&hdl_alp[ndx], ghp,
325 			    AL_CNT_HANDLES);
326 
327 			if (DBG_ENABLED) {
328 				Aliste		idx;
329 				Grp_desc	*gdp;
330 
331 				DBG_CALL(Dbg_file_hdl_title(DBG_HDL_REINST));
332 				for (ALIST_TRAVERSE(ghp->gh_depends, idx, gdp))
333 					DBG_CALL(Dbg_file_hdl_action(ghp,
334 					    gdp->gd_depend, DBG_DEP_REINST, 0));
335 			}
336 		}
337 
338 		/*
339 		 * If we've been asked to create a private handle, there's no
340 		 * need to track the caller.
341 		 */
342 		if (hflags & GPH_PRIVATE) {
343 			/*
344 			 * Negate the reference count increment.
345 			 */
346 			ghp->gh_refcnt--;
347 			return (ghp);
348 		} else {
349 			/*
350 			 * If a private handle already exists, promote this
351 			 * handle to public by initializing both the reference
352 			 * count and the handle flags.
353 			 */
354 			if (ghp->gh_flags & GPH_PRIVATE) {
355 				ghp->gh_refcnt = 1;
356 				ghp->gh_flags &= ~GPH_PRIVATE;
357 				ghp->gh_flags |= hflags;
358 			}
359 		}
360 	}
361 
362 	/*
363 	 * Keep track of the parent (caller).  As this object can be referenced
364 	 * by different parents, this processing is carried out every time a
365 	 * handle is requested.
366 	 */
367 	if (clmp && (hdl_add(ghp, clmp, cdflags, NULL) == NULL))
368 		return (NULL);
369 
370 	return (ghp);
371 }
372 
373 /*
374  * Initialize a handle that has been created for an object that is already
375  * loaded.  The handle is initialized with the present dependencies of that
376  * object.  Once this initialization has occurred, any new objects that might
377  * be loaded as dependencies (lazy-loading) are added to the handle as each new
378  * object is loaded.
379  */
380 int
381 hdl_initialize(Grp_hdl *ghp, Rt_map *nlmp, int mode, int promote)
382 {
383 	Aliste		idx;
384 	Grp_desc	*gdp;
385 
386 	/*
387 	 * If the handle has already been initialized, and the initial object's
388 	 * mode hasn't been promoted, there's no need to recompute the modes of
389 	 * any dependencies.  If the object we've added has just been opened,
390 	 * the objects dependencies will not yet have been processed.  These
391 	 * dependencies will be added on later calls to load_one().  Otherwise,
392 	 * this object already exists, so add all of its dependencies to the
393 	 * handle were operating on.
394 	 */
395 	if (((ghp->gh_flags & GPH_INITIAL) && (promote == 0)) ||
396 	    ((FLAGS(nlmp) & FLG_RT_ANALYZED) == 0)) {
397 		ghp->gh_flags |= GPH_INITIAL;
398 		return (1);
399 	}
400 
401 	DBG_CALL(Dbg_file_hdl_title(DBG_HDL_ADD));
402 	for (ALIST_TRAVERSE(ghp->gh_depends, idx, gdp)) {
403 		Rt_map		*lmp = gdp->gd_depend;
404 		Aliste		idx1;
405 		Bnd_desc	*bdp;
406 
407 		/*
408 		 * If this dependency doesn't indicate that its dependencies
409 		 * should be added to a handle, ignore it.  This case identifies
410 		 * a parent of a dlopen(RTLD_PARENT) request.
411 		 */
412 		if ((gdp->gd_flags & GPD_ADDEPS) == 0)
413 			continue;
414 
415 		for (APLIST_TRAVERSE(DEPENDS(lmp), idx1, bdp)) {
416 			Rt_map	*dlmp = bdp->b_depend;
417 
418 			if ((bdp->b_flags & BND_NEEDED) == 0)
419 				continue;
420 
421 			if (hdl_add(ghp, dlmp,
422 			    (GPD_DLSYM | GPD_RELOC | GPD_ADDEPS), NULL) == NULL)
423 				return (0);
424 
425 			(void) update_mode(dlmp, MODE(dlmp), mode);
426 		}
427 	}
428 	ghp->gh_flags |= GPH_INITIAL;
429 	return (1);
430 }
431 
432 /*
433  * Sanity check a program-provided handle.
434  */
435 static int
436 hdl_validate(Grp_hdl *ghp)
437 {
438 	Aliste		idx;
439 	Grp_hdl		*lghp;
440 	uint_t		ndx;
441 
442 	/* LINTED */
443 	ndx = (uintptr_t)ghp % HDLIST_SZ;
444 
445 	for (APLIST_TRAVERSE(hdl_alp[ndx], idx, lghp)) {
446 		if ((lghp == ghp) && (ghp->gh_refcnt != 0))
447 			return (1);
448 	}
449 	return (0);
450 }
451 
452 /*
453  * Core dlclose activity.
454  */
455 int
456 dlclose_core(Grp_hdl *ghp, Rt_map *clmp, Lm_list *lml)
457 {
458 	int	error;
459 
460 	/*
461 	 * If we're already at atexit() there's no point processing further,
462 	 * all objects have already been tsorted for fini processing.
463 	 */
464 	if (rtld_flags & RT_FL_ATEXIT)
465 		return (0);
466 
467 	/*
468 	 * Diagnose what we're up to.
469 	 */
470 	if (ghp->gh_flags & GPH_ZERO) {
471 		DBG_CALL(Dbg_dl_dlclose(clmp, MSG_ORIG(MSG_STR_ZERO),
472 		    DBG_DLCLOSE_IGNORE));
473 	} else {
474 		DBG_CALL(Dbg_dl_dlclose(clmp, NAME(ghp->gh_ownlmp),
475 		    DBG_DLCLOSE_NULL));
476 	}
477 
478 	/*
479 	 * Decrement reference count of this object.
480 	 */
481 	if (--(ghp->gh_refcnt))
482 		return (0);
483 
484 	/*
485 	 * If this handle is special (dlopen(0)), then leave it around - it
486 	 * has little overhead.
487 	 */
488 	if (ghp->gh_flags & GPH_ZERO)
489 		return (0);
490 
491 	/*
492 	 * This handle is no longer being referenced, remove it.  If this handle
493 	 * is part of an alternative link-map list, determine if the whole list
494 	 * can be removed also.
495 	 */
496 	error = remove_hdl(ghp, clmp, NULL);
497 
498 	if ((lml->lm_flags & (LML_FLG_BASELM | LML_FLG_RTLDLM)) == 0)
499 		remove_lml(lml);
500 
501 	return (error);
502 }
503 
504 /*
505  * Internal dlclose activity.  Called from user level or directly for internal
506  * error cleanup.
507  */
508 int
509 dlclose_intn(Grp_hdl *ghp, Rt_map *clmp)
510 {
511 	Rt_map	*nlmp = NULL;
512 	Lm_list	*olml = NULL;
513 	int	error;
514 
515 	/*
516 	 * Although we're deleting object(s) it's quite possible that additional
517 	 * objects get loaded from running the .fini section(s) of the objects
518 	 * being deleted.  These objects will have been added to the same
519 	 * link-map list as those objects being deleted.  Remember this list
520 	 * for later investigation.
521 	 */
522 	olml = ghp->gh_ownlml;
523 
524 	error = dlclose_core(ghp, clmp, olml);
525 
526 	/*
527 	 * Determine whether the original link-map list still exists.  In the
528 	 * case of a dlclose of an alternative (dlmopen) link-map the whole
529 	 * list may have been removed.
530 	 */
531 	if (olml) {
532 		Aliste	idx;
533 		Lm_list	*lml;
534 
535 		for (APLIST_TRAVERSE(dynlm_list, idx, lml)) {
536 			if (olml == lml) {
537 				nlmp = olml->lm_head;
538 				break;
539 			}
540 		}
541 	}
542 	load_completion(nlmp);
543 	return (error);
544 }
545 
546 /*
547  * Argument checking for dlclose.  Only called via external entry.
548  */
549 static int
550 dlclose_check(void *handle, Rt_map *clmp)
551 {
552 	Grp_hdl	*ghp = (Grp_hdl *)handle;
553 
554 	if (hdl_validate(ghp) == 0) {
555 		Conv_inv_buf_t	inv_buf;
556 
557 		(void) conv_invalid_val(&inv_buf, EC_NATPTR(ghp), 0);
558 		DBG_CALL(Dbg_dl_dlclose(clmp, inv_buf.buf, DBG_DLCLOSE_NULL));
559 
560 		eprintf(LIST(clmp), ERR_FATAL, MSG_INTL(MSG_ARG_INVHNDL),
561 		    EC_NATPTR(handle));
562 		return (1);
563 	}
564 	return (dlclose_intn(ghp, clmp));
565 }
566 
567 #pragma weak _dlclose = dlclose
568 
569 /*
570  * External entry for dlclose(3dl).  Returns 0 for success, non-zero otherwise.
571  */
572 int
573 dlclose(void *handle)
574 {
575 	int		error, entry;
576 	Rt_map		*clmp;
577 
578 	entry = enter(0);
579 
580 	clmp = _caller(caller(), CL_EXECDEF);
581 
582 	error = dlclose_check(handle, clmp);
583 
584 	if (entry)
585 		leave(LIST(clmp), 0);
586 	return (error);
587 }
588 
589 static uint_t	lmid = 0;
590 
591 /*
592  * The addition of new link-map lists is assumed to be in small quantities.
593  * Here, we assign a unique link-map id for diagnostic use.  Simply update the
594  * running link-map count until we max out.
595  */
596 int
597 newlmid(Lm_list *lml)
598 {
599 	char	buffer[MSG_LMID_ALT_SIZE + 12];
600 
601 	if (lmid == UINT_MAX) {
602 		lml->lm_lmid = UINT_MAX;
603 		(void) strncpy(buffer, MSG_ORIG(MSG_LMID_MAXED),
604 		    MSG_LMID_ALT_SIZE + 12);
605 	} else {
606 		lml->lm_lmid = lmid++;
607 		(void) snprintf(buffer, MSG_LMID_ALT_SIZE + 12,
608 		    MSG_ORIG(MSG_LMID_FMT), MSG_ORIG(MSG_LMID_ALT),
609 		    lml->lm_lmid);
610 	}
611 	if ((lml->lm_lmidstr = strdup(buffer)) == NULL)
612 		return (0);
613 
614 	return (1);
615 }
616 
617 /*
618  * Core dlopen activity.
619  */
620 static Grp_hdl *
621 dlmopen_core(Lm_list *lml, Lm_list *olml, const char *path, int mode,
622     Rt_map *clmp, uint_t flags, uint_t orig, int *in_nfavl)
623 {
624 	Alist		*palp = NULL;
625 	Rt_map		*nlmp;
626 	Grp_hdl		*ghp;
627 	Aliste		olmco, nlmco;
628 
629 	DBG_CALL(Dbg_dl_dlopen(clmp,
630 	    (path ? path : MSG_ORIG(MSG_STR_ZERO)), in_nfavl, mode));
631 
632 	/*
633 	 * Having diagnosed the originally defined modes, assign any defaults
634 	 * or corrections.
635 	 */
636 	if (((mode & (RTLD_GROUP | RTLD_WORLD)) == 0) &&
637 	    ((mode & RTLD_NOLOAD) == 0))
638 		mode |= (RTLD_GROUP | RTLD_WORLD);
639 	if ((mode & RTLD_NOW) && (rtld_flags2 & RT_FL2_BINDLAZY)) {
640 		mode &= ~RTLD_NOW;
641 		mode |= RTLD_LAZY;
642 	}
643 
644 	/*
645 	 * If the path specified is null then we're operating on global
646 	 * objects.  Associate a dummy handle with the link-map list.
647 	 */
648 	if (path == NULL) {
649 		Grp_hdl *ghp;
650 		uint_t	hflags, rdflags, cdflags;
651 		int	promote = 0;
652 
653 		/*
654 		 * Establish any flags for the handle (Grp_hdl).
655 		 *
656 		 *  -	This is a dummy, public, handle (0) that provides for a
657 		 *	dynamic	search of all global objects within the process.
658 		 *  -   Use of the RTLD_FIRST mode indicates that only the first
659 		 *	dependency on the handle (the referenced object) can be
660 		 *	used to satisfy dlsym() requests.
661 		 */
662 		hflags = (GPH_PUBLIC | GPH_ZERO);
663 		if (mode & RTLD_FIRST)
664 			hflags |= GPH_FIRST;
665 
666 		/*
667 		 * Establish the flags for the referenced dependency descriptor
668 		 * (Grp_desc).
669 		 *
670 		 *  -	The referenced object is available for dlsym().
671 		 *  -	The referenced object is available to relocate against.
672 		 *  -	The referenced object should have it's dependencies
673 		 *	added to this handle.
674 		 */
675 		rdflags = (GPD_DLSYM | GPD_RELOC | GPD_ADDEPS);
676 
677 		/*
678 		 * Establish the flags for this callers dependency descriptor
679 		 * (Grp_desc).
680 		 *
681 		 *  -	The explicit creation of a handle creates a descriptor
682 		 *	for the referenced object and the parent (caller).
683 		 *  -	Use of the RTLD_PARENT flag indicates that the parent
684 		 *	can be relocated against.
685 		 */
686 		cdflags = GPD_PARENT;
687 		if (mode & RTLD_PARENT)
688 			cdflags |= GPD_RELOC;
689 
690 		if ((ghp = hdl_create(lml, 0, clmp, hflags, rdflags,
691 		    cdflags)) == NULL)
692 			return (NULL);
693 
694 		/*
695 		 * Traverse the main link-map control list, updating the mode
696 		 * of any objects as necessary.  Call the relocation engine if
697 		 * this mode promotes the existing state of any relocations.
698 		 * crle()'s first pass loads all objects necessary for building
699 		 * a configuration file, however none of them are relocated.
700 		 * crle()'s second pass relocates objects in preparation for
701 		 * dldump()'ing using dlopen(0, RTLD_NOW).
702 		 */
703 		if ((mode & (RTLD_NOW | RTLD_CONFGEN)) == RTLD_CONFGEN)
704 			return (ghp);
705 
706 		for (nlmp = lml->lm_head; nlmp; nlmp = NEXT_RT_MAP(nlmp)) {
707 			if (((MODE(nlmp) & RTLD_GLOBAL) == 0) ||
708 			    (FLAGS(nlmp) & FLG_RT_DELETE))
709 				continue;
710 
711 			if (update_mode(nlmp, MODE(nlmp), mode))
712 				promote = 1;
713 		}
714 		if (promote)
715 			(void) relocate_lmc(lml, ALIST_OFF_DATA, clmp,
716 			    lml->lm_head, in_nfavl);
717 
718 		return (ghp);
719 	}
720 
721 	/*
722 	 * Fix the pathname.  If this object expands to multiple paths (ie.
723 	 * $ISALIST or $HWCAP have been used), then make sure the user has also
724 	 * furnished the RTLD_FIRST flag.  As yet, we don't support opening
725 	 * more than one object at a time, so enforcing the RTLD_FIRST flag
726 	 * provides flexibility should we be able to support dlopening more
727 	 * than one object in the future.
728 	 */
729 	if (LM_FIX_NAME(clmp)(path, clmp, &palp, AL_CNT_NEEDED, orig) == NULL)
730 		return (NULL);
731 
732 	if ((palp->al_arritems > 1) && ((mode & RTLD_FIRST) == 0)) {
733 		remove_plist(&palp, 1);
734 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLMODE_5));
735 		return (NULL);
736 	}
737 
738 	/*
739 	 * Establish a link-map control list for this request, and load the
740 	 * associated object.
741 	 */
742 	if ((nlmco = create_cntl(lml, 1)) == NULL) {
743 		remove_plist(&palp, 1);
744 		return (NULL);
745 	}
746 	olmco = nlmco;
747 
748 	nlmp = load_one(lml, nlmco, palp, clmp, mode, (flags | FLG_RT_PUBHDL),
749 	    &ghp, in_nfavl);
750 
751 	/*
752 	 * Remove any expanded pathname infrastructure, and if the dependency
753 	 * couldn't be loaded, cleanup.
754 	 */
755 	remove_plist(&palp, 1);
756 	if (nlmp == NULL) {
757 		remove_cntl(lml, olmco);
758 		return (NULL);
759 	}
760 
761 	/*
762 	 * If loading an auditor was requested, and the auditor already existed,
763 	 * then the link-map returned will be to the original auditor.  The new
764 	 * link-map list that was initially created, and the associated link-map
765 	 * control list are no longer needed.  As the auditor is already loaded,
766 	 * we're probably done, but fall through in case additional relocations
767 	 * would be triggered by the mode of the caller.
768 	 */
769 	if ((flags & FLG_RT_AUDIT) && (LIST(nlmp) != lml)) {
770 		remove_cntl(lml, olmco);
771 		lml = LIST(nlmp);
772 		olmco = 0;
773 		nlmco = ALIST_OFF_DATA;
774 	}
775 
776 	/*
777 	 * Finish processing the objects associated with this request.
778 	 */
779 	if (((nlmp = analyze_lmc(lml, nlmco, nlmp, in_nfavl)) == NULL) ||
780 	    (relocate_lmc(lml, nlmco, clmp, nlmp, in_nfavl) == 0)) {
781 		ghp = NULL;
782 		nlmp = NULL;
783 	}
784 
785 	/*
786 	 * If the dlopen has failed, clean up any objects that might have been
787 	 * loaded successfully on this new link-map control list.
788 	 */
789 	if (olmco && (nlmp == NULL))
790 		remove_lmc(lml, clmp, olmco, path);
791 
792 	/*
793 	 * Finally, remove any temporary link-map control list.  Note, if this
794 	 * operation successfully established a new link-map list, then a base
795 	 * link-map control list will have been created, which must remain.
796 	 */
797 	if (olmco && ((nlmp == NULL) || (olml != (Lm_list *)LM_ID_NEWLM)))
798 		remove_cntl(lml, olmco);
799 
800 	return (ghp);
801 }
802 
803 /*
804  * dlopen() and dlsym() operations are the means by which a process can
805  * test for the existence of required dependencies.  If the necessary
806  * dependencies don't exist, then associated functionality can't be used.
807  * However, the lack of dependencies can be fixed, and the dlopen() and
808  * dlsym() requests can be repeated.  As we use a "not-found" AVL tree to
809  * cache any failed full path loads, secondary dlopen() and dlsym() requests
810  * will fail, even if the dependencies have been installed.
811  *
812  * dlopen() and dlsym() retry any failures by removing the "not-found" AVL
813  * tree.  Should any dependencies be found, their names are added to the
814  * FullPath AVL tree.  This routine removes any new "not-found" AVL tree,
815  * so that the dlopen() or dlsym() can replace the original "not-found" tree.
816  */
817 inline static void
818 nfavl_remove(avl_tree_t *avlt)
819 {
820 	PathNode	*pnp;
821 	void		*cookie = NULL;
822 
823 	if (avlt) {
824 		while ((pnp = avl_destroy_nodes(avlt, &cookie)) != NULL)
825 			free(pnp);
826 
827 		avl_destroy(avlt);
828 		free(avlt);
829 	}
830 }
831 
832 /*
833  * Internal dlopen() activity.  Called from user level or directly for internal
834  * opens that require a handle.
835  */
836 Grp_hdl *
837 dlmopen_intn(Lm_list *lml, const char *path, int mode, Rt_map *clmp,
838     uint_t flags, uint_t orig)
839 {
840 	Lm_list	*olml = lml;
841 	Rt_map	*dlmp = NULL;
842 	Grp_hdl	*ghp;
843 	int	in_nfavl = 0;
844 
845 	/*
846 	 * Check for magic link-map list values:
847 	 *
848 	 *  LM_ID_BASE:		Operate on the PRIMARY (executables) link map
849 	 *  LM_ID_LDSO:		Operation on ld.so.1's link map
850 	 *  LM_ID_NEWLM: 	Create a new link-map.
851 	 */
852 	if (lml == (Lm_list *)LM_ID_NEWLM) {
853 		if ((lml = calloc(sizeof (Lm_list), 1)) == NULL)
854 			return (NULL);
855 
856 		/*
857 		 * Establish the new link-map flags from the callers and those
858 		 * explicitly provided.
859 		 */
860 		lml->lm_tflags = LIST(clmp)->lm_tflags;
861 		if (flags & FLG_RT_AUDIT) {
862 			/*
863 			 * Unset any auditing flags - an auditor shouldn't be
864 			 * audited.  Insure all audit dependencies are loaded.
865 			 */
866 			lml->lm_tflags &= ~LML_TFLG_AUD_MASK;
867 			lml->lm_tflags |=
868 			    (LML_TFLG_NOLAZYLD | LML_TFLG_LOADFLTR);
869 			lml->lm_flags |= LML_FLG_NOAUDIT;
870 		}
871 
872 		if (aplist_append(&dynlm_list, lml, AL_CNT_DYNLIST) == NULL) {
873 			free(lml);
874 			return (NULL);
875 		}
876 		if (newlmid(lml) == 0) {
877 			(void) aplist_delete_value(dynlm_list, lml);
878 			free(lml);
879 			return (NULL);
880 		}
881 	} else if ((uintptr_t)lml < LM_ID_NUM) {
882 		if ((uintptr_t)lml == LM_ID_BASE)
883 			lml = &lml_main;
884 		else if ((uintptr_t)lml == LM_ID_LDSO)
885 			lml = &lml_rtld;
886 	}
887 
888 	/*
889 	 * Open the required object on the associated link-map list.
890 	 */
891 	ghp = dlmopen_core(lml, olml, path, mode, clmp, flags, orig, &in_nfavl);
892 
893 	/*
894 	 * If the object could not be found it is possible that the "not-found"
895 	 * AVL tree had indicated that the file does not exist.  In case the
896 	 * file system has changed since this "not-found" recording was made,
897 	 * retry the dlopen() with a clean "not-found" AVL tree.
898 	 */
899 	if ((ghp == NULL) && in_nfavl) {
900 		avl_tree_t	*oavlt = nfavl;
901 
902 		nfavl = NULL;
903 		ghp = dlmopen_core(lml, olml, path, mode, clmp, flags, orig,
904 		    NULL);
905 
906 		/*
907 		 * If the file is found, then its full path name will have been
908 		 * registered in the FullPath AVL tree.  Remove any new
909 		 * "not-found" AVL information, and restore the former AVL tree.
910 		 */
911 		nfavl_remove(nfavl);
912 		nfavl = oavlt;
913 	}
914 
915 	/*
916 	 * Establish the new link-map from which .init processing will begin.
917 	 * Ignore .init firing when constructing a configuration file (crle(1)).
918 	 */
919 	if (ghp && ((mode & RTLD_CONFGEN) == 0))
920 		dlmp = ghp->gh_ownlmp;
921 
922 	/*
923 	 * If loading an auditor was requested, and the auditor already existed,
924 	 * then the link-map returned will be to the original auditor.  Remove
925 	 * the link-map control list that was created for this request.
926 	 */
927 	if (dlmp && (flags & FLG_RT_AUDIT) && (LIST(dlmp) != lml)) {
928 		remove_lml(lml);
929 		lml = LIST(dlmp);
930 	}
931 
932 	/*
933 	 * If this load failed, remove any alternative link-map list.
934 	 */
935 	if ((ghp == NULL) &&
936 	    ((lml->lm_flags & (LML_FLG_BASELM | LML_FLG_RTLDLM)) == 0)) {
937 		remove_lml(lml);
938 		lml = NULL;
939 	}
940 
941 	/*
942 	 * Finish this load request.  If objects were loaded, .init processing
943 	 * is computed.  Finally, the debuggers are informed of the link-map
944 	 * lists being stable.
945 	 */
946 	load_completion(dlmp);
947 
948 	return (ghp);
949 }
950 
951 /*
952  * Argument checking for dlopen.  Only called via external entry.
953  */
954 static Grp_hdl *
955 dlmopen_check(Lm_list *lml, const char *path, int mode, Rt_map *clmp)
956 {
957 	/*
958 	 * Verify that a valid pathname has been supplied.
959 	 */
960 	if (path && (*path == '\0')) {
961 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLPATH));
962 		return (0);
963 	}
964 
965 	/*
966 	 * Historically we've always verified the mode is either RTLD_NOW or
967 	 * RTLD_LAZY.  RTLD_NOLOAD is valid by itself.  Use of LM_ID_NEWLM
968 	 * requires a specific pathname, and use of RTLD_PARENT is meaningless.
969 	 */
970 	if ((mode & (RTLD_NOW | RTLD_LAZY | RTLD_NOLOAD)) == 0) {
971 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLMODE_1));
972 		return (0);
973 	}
974 	if ((mode & (RTLD_NOW | RTLD_LAZY)) == (RTLD_NOW | RTLD_LAZY)) {
975 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLMODE_2));
976 		return (0);
977 	}
978 	if ((lml == (Lm_list *)LM_ID_NEWLM) && (path == NULL)) {
979 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLMODE_3));
980 		return (0);
981 	}
982 	if ((lml == (Lm_list *)LM_ID_NEWLM) && (mode & RTLD_PARENT)) {
983 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLMODE_4));
984 		return (0);
985 	}
986 
987 	return (dlmopen_intn(lml, path, mode, clmp, 0, 0));
988 }
989 
990 #pragma weak _dlopen = dlopen
991 
992 /*
993  * External entry for dlopen(3dl).  On success, returns a pointer (handle) to
994  * the structure containing information about the newly added object, ie. can
995  * be used by dlsym(). On failure, returns a null pointer.
996  */
997 void *
998 dlopen(const char *path, int mode)
999 {
1000 	int	entry;
1001 	Rt_map	*clmp;
1002 	Grp_hdl	*ghp;
1003 	Lm_list	*lml;
1004 
1005 	entry = enter(0);
1006 
1007 	clmp = _caller(caller(), CL_EXECDEF);
1008 	lml = LIST(clmp);
1009 
1010 	ghp = dlmopen_check(lml, path, mode, clmp);
1011 
1012 	if (entry)
1013 		leave(lml, 0);
1014 	return ((void *)ghp);
1015 }
1016 
1017 #pragma weak _dlmopen = dlmopen
1018 
1019 /*
1020  * External entry for dlmopen(3dl).
1021  */
1022 void *
1023 dlmopen(Lmid_t lmid, const char *path, int mode)
1024 {
1025 	int	entry;
1026 	Rt_map	*clmp;
1027 	Grp_hdl	*ghp;
1028 
1029 	entry = enter(0);
1030 
1031 	clmp = _caller(caller(), CL_EXECDEF);
1032 
1033 	ghp = dlmopen_check((Lm_list *)lmid, path, mode, clmp);
1034 
1035 	if (entry)
1036 		leave(LIST(clmp), 0);
1037 	return ((void *)ghp);
1038 }
1039 
1040 /*
1041  * Handle processing for dlsym.
1042  */
1043 int
1044 dlsym_handle(Grp_hdl *ghp, Slookup *slp, Sresult *srp, uint_t *binfo,
1045     int *in_nfavl)
1046 {
1047 	Rt_map		*nlmp, * lmp = ghp->gh_ownlmp;
1048 	Rt_map		*clmp = slp->sl_cmap;
1049 	const char	*name = slp->sl_name;
1050 	Slookup		sl = *slp;
1051 
1052 	sl.sl_flags = (LKUP_FIRST | LKUP_DLSYM | LKUP_SPEC);
1053 
1054 	/*
1055 	 * Continue processing a dlsym request.  Lookup the required symbol in
1056 	 * each link-map specified by the handle.
1057 	 *
1058 	 * To leverage off of lazy loading, dlsym() requests can result in two
1059 	 * passes.  The first descends the link-maps of any objects already in
1060 	 * the address space.  If the symbol isn't located, and lazy
1061 	 * dependencies still exist, then a second pass is made to load these
1062 	 * dependencies if applicable.  This model means that in the case where
1063 	 * a symbol exists in more than one object, the one located may not be
1064 	 * constant - this is the standard issue with lazy loading. In addition,
1065 	 * attempting to locate a symbol that doesn't exist will result in the
1066 	 * loading of all lazy dependencies on the given handle, which can
1067 	 * defeat some of the advantages of lazy loading (look out JVM).
1068 	 */
1069 	if (ghp->gh_flags & GPH_ZERO) {
1070 		Lm_list	*lml;
1071 		uint_t	lazy = 0;
1072 
1073 		/*
1074 		 * If this symbol lookup is triggered from a dlopen(0) handle,
1075 		 * traverse the present link-map list looking for promiscuous
1076 		 * entries.
1077 		 */
1078 		for (nlmp = lmp; nlmp; nlmp = NEXT_RT_MAP(nlmp)) {
1079 			/*
1080 			 * If this handle indicates we're only to look in the
1081 			 * first object check whether we're done.
1082 			 */
1083 			if ((nlmp != lmp) && (ghp->gh_flags & GPH_FIRST))
1084 				return (0);
1085 
1086 			if (!(MODE(nlmp) & RTLD_GLOBAL))
1087 				continue;
1088 			if ((FLAGS(nlmp) & FLG_RT_DELETE) &&
1089 			    ((FLAGS(clmp) & FLG_RT_DELETE) == 0))
1090 				continue;
1091 
1092 			sl.sl_imap = nlmp;
1093 			if (LM_LOOKUP_SYM(clmp)(&sl, srp, binfo, in_nfavl))
1094 				return (1);
1095 
1096 			/*
1097 			 * Keep track of any global pending lazy loads.
1098 			 */
1099 			lazy += LAZY(nlmp);
1100 		}
1101 
1102 		/*
1103 		 * If we're unable to locate the symbol and this link-map list
1104 		 * still has pending lazy dependencies, start loading them in an
1105 		 * attempt to exhaust the search.  Note that as we're already
1106 		 * traversing a dynamic linked list of link-maps there's no
1107 		 * need for elf_lazy_find_sym() to descend the link-maps itself.
1108 		 */
1109 		lml = LIST(lmp);
1110 		if (lazy) {
1111 			DBG_CALL(Dbg_syms_lazy_rescan(lml, name));
1112 
1113 			sl.sl_flags |= LKUP_NODESCENT;
1114 
1115 			for (nlmp = lmp; nlmp; nlmp = NEXT_RT_MAP(nlmp)) {
1116 
1117 				if (!(MODE(nlmp) & RTLD_GLOBAL) || !LAZY(nlmp))
1118 					continue;
1119 				if ((FLAGS(nlmp) & FLG_RT_DELETE) &&
1120 				    ((FLAGS(clmp) & FLG_RT_DELETE) == 0))
1121 					continue;
1122 
1123 				sl.sl_imap = nlmp;
1124 				if (elf_lazy_find_sym(&sl, srp, binfo,
1125 				    in_nfavl))
1126 					return (1);
1127 			}
1128 		}
1129 	} else {
1130 		/*
1131 		 * Traverse the dlopen() handle searching all presently loaded
1132 		 * link-maps.
1133 		 */
1134 		Grp_desc	*gdp;
1135 		Aliste		idx;
1136 		uint_t		lazy = 0;
1137 
1138 		for (ALIST_TRAVERSE(ghp->gh_depends, idx, gdp)) {
1139 			nlmp = gdp->gd_depend;
1140 
1141 			if ((gdp->gd_flags & GPD_DLSYM) == 0)
1142 				continue;
1143 
1144 			sl.sl_imap = nlmp;
1145 			if (LM_LOOKUP_SYM(clmp)(&sl, srp, binfo, in_nfavl))
1146 				return (1);
1147 
1148 			if (ghp->gh_flags & GPH_FIRST)
1149 				return (0);
1150 
1151 			/*
1152 			 * Keep track of any pending lazy loads associated
1153 			 * with this handle.
1154 			 */
1155 			lazy += LAZY(nlmp);
1156 		}
1157 
1158 		/*
1159 		 * If we're unable to locate the symbol and this handle still
1160 		 * has pending lazy dependencies, start loading the lazy
1161 		 * dependencies, in an attempt to exhaust the search.
1162 		 */
1163 		if (lazy) {
1164 			DBG_CALL(Dbg_syms_lazy_rescan(LIST(lmp), name));
1165 
1166 			for (ALIST_TRAVERSE(ghp->gh_depends, idx, gdp)) {
1167 				nlmp = gdp->gd_depend;
1168 
1169 				if (((gdp->gd_flags & GPD_DLSYM) == 0) ||
1170 				    (LAZY(nlmp) == 0))
1171 					continue;
1172 
1173 				sl.sl_imap = nlmp;
1174 				if (elf_lazy_find_sym(&sl, srp, binfo,
1175 				    in_nfavl))
1176 					return (1);
1177 			}
1178 		}
1179 	}
1180 	return (0);
1181 }
1182 
1183 /*
1184  * Determine whether a symbol resides in a caller.  This may be a reference,
1185  * which is associated with a specific dependency.
1186  */
1187 inline static Sym *
1188 sym_lookup_in_caller(Rt_map *clmp, Slookup *slp, Sresult *srp, uint_t *binfo)
1189 {
1190 	if (THIS_IS_ELF(clmp) && SYMINTP(clmp)(slp, srp, binfo, NULL)) {
1191 		Sym	*sym = srp->sr_sym;
1192 
1193 		slp->sl_rsymndx = (((ulong_t)sym -
1194 		    (ulong_t)SYMTAB(clmp)) / SYMENT(clmp));
1195 		slp->sl_rsym = sym;
1196 		return (sym);
1197 	}
1198 	return (NULL);
1199 }
1200 
1201 /*
1202  * Core dlsym activity.  Selects symbol lookup method from handle.
1203  */
1204 static void *
1205 dlsym_core(void *handle, const char *name, Rt_map *clmp, Rt_map **dlmp,
1206     int *in_nfavl)
1207 {
1208 	Sym		*sym;
1209 	int		ret = 0;
1210 	Syminfo		*sip;
1211 	Slookup		sl;
1212 	Sresult		sr;
1213 	uint_t		binfo;
1214 
1215 	/*
1216 	 * Initialize the symbol lookup data structure.
1217 	 *
1218 	 * Standard relocations are evaluated using the symbol index of the
1219 	 * associated relocation symbol.  This index provides for loading
1220 	 * any lazy dependency and establishing a direct binding if necessary.
1221 	 * If a dlsym() operation originates from an object that contains a
1222 	 * symbol table entry for the same name, then we need to establish the
1223 	 * symbol index so that any dependency requirements can be triggered.
1224 	 *
1225 	 * Therefore, the first symbol lookup that is carried out is for the
1226 	 * symbol name within the calling object.  If this symbol exists, the
1227 	 * symbols index is computed, added to the Slookup data, and thus used
1228 	 * to seed the real symbol lookup.
1229 	 */
1230 	SLOOKUP_INIT(sl, name, clmp, clmp, ld_entry_cnt, elf_hash(name),
1231 	    0, 0, 0, LKUP_SYMNDX);
1232 	SRESULT_INIT(sr, name);
1233 	sym = sym_lookup_in_caller(clmp, &sl, &sr, &binfo);
1234 
1235 	SRESULT_INIT(sr, name);
1236 
1237 	if (sym && (ELF_ST_VISIBILITY(sym->st_other) == STV_SINGLETON)) {
1238 		Rt_map	*hlmp = LIST(clmp)->lm_head;
1239 
1240 		/*
1241 		 * If a symbol reference is known, and that reference indicates
1242 		 * that the symbol is a singleton, then the search for the
1243 		 * symbol must follow the default search path.
1244 		 */
1245 		DBG_CALL(Dbg_dl_dlsym(clmp, name, in_nfavl, 0,
1246 		    DBG_DLSYM_SINGLETON));
1247 
1248 		sl.sl_imap = hlmp;
1249 		if (handle == RTLD_PROBE)
1250 			sl.sl_flags = LKUP_NOFALLBACK;
1251 		else
1252 			sl.sl_flags = LKUP_SPEC;
1253 		ret = LM_LOOKUP_SYM(clmp)(&sl, &sr, &binfo, in_nfavl);
1254 
1255 	} else if (handle == RTLD_NEXT) {
1256 		Rt_map	*nlmp;
1257 
1258 		/*
1259 		 * If this handle is RTLD_NEXT determine whether a lazy load
1260 		 * from the caller might provide the next object.  This mimics
1261 		 * the lazy loading initialization normally carried out by
1262 		 * lookup_sym(), however here, we must do this up-front, as
1263 		 * lookup_sym() will be used to inspect the next object.
1264 		 */
1265 		if ((sl.sl_rsymndx) && ((sip = SYMINFO(clmp)) != NULL)) {
1266 			/* LINTED */
1267 			sip = (Syminfo *)((char *)sip +
1268 			    (sl.sl_rsymndx * SYMINENT(clmp)));
1269 
1270 			if ((sip->si_flags & SYMINFO_FLG_DIRECT) &&
1271 			    (sip->si_boundto < SYMINFO_BT_LOWRESERVE))
1272 				(void) elf_lazy_load(clmp, &sl,
1273 				    sip->si_boundto, name, 0, NULL, in_nfavl);
1274 
1275 			/*
1276 			 * Clear the symbol index, so as not to confuse
1277 			 * lookup_sym() of the next object.
1278 			 */
1279 			sl.sl_rsymndx = 0;
1280 			sl.sl_rsym = NULL;
1281 		}
1282 
1283 		/*
1284 		 * If the handle is RTLD_NEXT, start searching in the next link
1285 		 * map from the callers.  Determine permissions from the
1286 		 * present link map.  Indicate to lookup_sym() that we're on an
1287 		 * RTLD_NEXT request so that it will use the callers link map to
1288 		 * start any possible lazy dependency loading.
1289 		 */
1290 		sl.sl_imap = nlmp = NEXT_RT_MAP(clmp);
1291 
1292 		DBG_CALL(Dbg_dl_dlsym(clmp, name, in_nfavl,
1293 		    (nlmp ? NAME(nlmp) : MSG_INTL(MSG_STR_NULL)),
1294 		    DBG_DLSYM_NEXT));
1295 
1296 		if (nlmp == NULL)
1297 			return (0);
1298 
1299 		sl.sl_flags = LKUP_NEXT;
1300 		ret = LM_LOOKUP_SYM(clmp)(&sl, &sr, &binfo, in_nfavl);
1301 
1302 	} else if (handle == RTLD_SELF) {
1303 		/*
1304 		 * If the handle is RTLD_SELF start searching from the caller.
1305 		 */
1306 		DBG_CALL(Dbg_dl_dlsym(clmp, name, in_nfavl, NAME(clmp),
1307 		    DBG_DLSYM_SELF));
1308 
1309 		sl.sl_imap = clmp;
1310 		sl.sl_flags = (LKUP_SPEC | LKUP_SELF);
1311 		ret = LM_LOOKUP_SYM(clmp)(&sl, &sr, &binfo, in_nfavl);
1312 
1313 	} else if (handle == RTLD_DEFAULT) {
1314 		Rt_map	*hlmp = LIST(clmp)->lm_head;
1315 
1316 		/*
1317 		 * If the handle is RTLD_DEFAULT mimic the standard symbol
1318 		 * lookup as would be triggered by a relocation.
1319 		 */
1320 		DBG_CALL(Dbg_dl_dlsym(clmp, name, in_nfavl, 0,
1321 		    DBG_DLSYM_DEFAULT));
1322 
1323 		sl.sl_imap = hlmp;
1324 		sl.sl_flags = LKUP_SPEC;
1325 		ret = LM_LOOKUP_SYM(clmp)(&sl, &sr, &binfo, in_nfavl);
1326 
1327 	} else if (handle == RTLD_PROBE) {
1328 		Rt_map	*hlmp = LIST(clmp)->lm_head;
1329 
1330 		/*
1331 		 * If the handle is RTLD_PROBE, mimic the standard symbol
1332 		 * lookup as would be triggered by a relocation, however do
1333 		 * not fall back to a lazy loading rescan if the symbol can't be
1334 		 * found within the currently loaded objects.  Note, a lazy
1335 		 * loaded dependency required by the caller might still get
1336 		 * loaded to satisfy this request, but no exhaustive lazy load
1337 		 * rescan is carried out.
1338 		 */
1339 		DBG_CALL(Dbg_dl_dlsym(clmp, name, in_nfavl, 0,
1340 		    DBG_DLSYM_PROBE));
1341 
1342 		sl.sl_imap = hlmp;
1343 		sl.sl_flags = LKUP_NOFALLBACK;
1344 		ret = LM_LOOKUP_SYM(clmp)(&sl, &sr, &binfo, in_nfavl);
1345 
1346 	} else {
1347 		Grp_hdl *ghp = (Grp_hdl *)handle;
1348 
1349 		/*
1350 		 * Look in the shared object specified by the handle and in all
1351 		 * of its dependencies.
1352 		 */
1353 		DBG_CALL(Dbg_dl_dlsym(clmp, name, in_nfavl,
1354 		    NAME(ghp->gh_ownlmp), DBG_DLSYM_DEF));
1355 
1356 		ret = LM_DLSYM(clmp)(ghp, &sl, &sr, &binfo, in_nfavl);
1357 	}
1358 
1359 	if (ret && ((sym = sr.sr_sym) != NULL)) {
1360 		Lm_list	*lml = LIST(clmp);
1361 		Addr	addr = sym->st_value;
1362 
1363 		*dlmp = sr.sr_dmap;
1364 		if (!(FLAGS(*dlmp) & FLG_RT_FIXED))
1365 			addr += ADDR(*dlmp);
1366 
1367 		/*
1368 		 * Indicate that the defining object is now used.
1369 		 */
1370 		if (*dlmp != clmp)
1371 			FLAGS1(*dlmp) |= FL1_RT_USED;
1372 
1373 		DBG_CALL(Dbg_bind_global(clmp, 0, 0, (Xword)-1, PLT_T_NONE,
1374 		    *dlmp, addr, sym->st_value, sr.sr_name, binfo));
1375 
1376 		if ((lml->lm_tflags | AFLAGS(clmp)) & LML_TFLG_AUD_SYMBIND) {
1377 			uint_t	sb_flags = LA_SYMB_DLSYM;
1378 			/* LINTED */
1379 			uint_t	symndx = (uint_t)(((Xword)sym -
1380 			    (Xword)SYMTAB(*dlmp)) / SYMENT(*dlmp));
1381 			addr = audit_symbind(clmp, *dlmp, sym, symndx, addr,
1382 			    &sb_flags);
1383 		}
1384 		return ((void *)addr);
1385 	}
1386 
1387 	return (NULL);
1388 }
1389 
1390 /*
1391  * Internal dlsym activity.  Called from user level or directly for internal
1392  * symbol lookup.
1393  */
1394 void *
1395 dlsym_intn(void *handle, const char *name, Rt_map *clmp, Rt_map **dlmp)
1396 {
1397 	Rt_map		*llmp = NULL;
1398 	void		*error;
1399 	Aliste		idx;
1400 	Grp_desc	*gdp;
1401 	int		in_nfavl = 0;
1402 
1403 	/*
1404 	 * While looking for symbols it's quite possible that additional objects
1405 	 * get loaded from lazy loading.  These objects will have been added to
1406 	 * the same link-map list as those objects on the handle.  Remember this
1407 	 * list for later investigation.
1408 	 */
1409 	if ((handle == RTLD_NEXT) || (handle == RTLD_DEFAULT) ||
1410 	    (handle == RTLD_SELF) || (handle == RTLD_PROBE))
1411 		llmp = LIST(clmp)->lm_tail;
1412 	else {
1413 		Grp_hdl	*ghp = (Grp_hdl *)handle;
1414 
1415 		if (ghp->gh_ownlmp)
1416 			llmp = LIST(ghp->gh_ownlmp)->lm_tail;
1417 		else {
1418 			for (ALIST_TRAVERSE(ghp->gh_depends, idx, gdp)) {
1419 				if ((llmp =
1420 				    LIST(gdp->gd_depend)->lm_tail) != NULL)
1421 					break;
1422 			}
1423 		}
1424 	}
1425 
1426 	error = dlsym_core(handle, name, clmp, dlmp, &in_nfavl);
1427 
1428 	/*
1429 	 * If the symbol could not be found it is possible that the "not-found"
1430 	 * AVL tree had indicated that a required file does not exist.  In case
1431 	 * the file system has changed since this "not-found" recording was
1432 	 * made, retry the dlsym() with a clean "not-found" AVL tree.
1433 	 */
1434 	if ((error == NULL) && in_nfavl) {
1435 		avl_tree_t	*oavlt = nfavl;
1436 
1437 		nfavl = NULL;
1438 		error = dlsym_core(handle, name, clmp, dlmp, NULL);
1439 
1440 		/*
1441 		 * If the symbol is found, then any file that was loaded will
1442 		 * have had its full path name registered in the FullPath AVL
1443 		 * tree.  Remove any new "not-found" AVL information, and
1444 		 * restore the former AVL tree.
1445 		 */
1446 		nfavl_remove(nfavl);
1447 		nfavl = oavlt;
1448 	}
1449 
1450 	if (error == NULL) {
1451 		/*
1452 		 * Cache the error message, as Java tends to fall through this
1453 		 * code many times.
1454 		 */
1455 		if (nosym_str == NULL)
1456 			nosym_str = MSG_INTL(MSG_GEN_NOSYM);
1457 		eprintf(LIST(clmp), ERR_FATAL, nosym_str, name);
1458 	}
1459 
1460 	load_completion(llmp);
1461 	return (error);
1462 }
1463 
1464 /*
1465  * Argument checking for dlsym.  Only called via external entry.
1466  */
1467 static void *
1468 dlsym_check(void *handle, const char *name, Rt_map *clmp, Rt_map **dlmp)
1469 {
1470 	/*
1471 	 * Verify the arguments.
1472 	 */
1473 	if (name == NULL) {
1474 		eprintf(LIST(clmp), ERR_FATAL, MSG_INTL(MSG_ARG_ILLSYM));
1475 		return (NULL);
1476 	}
1477 	if ((handle != RTLD_NEXT) && (handle != RTLD_DEFAULT) &&
1478 	    (handle != RTLD_SELF) && (handle != RTLD_PROBE) &&
1479 	    (hdl_validate((Grp_hdl *)handle) == 0)) {
1480 		eprintf(LIST(clmp), ERR_FATAL, MSG_INTL(MSG_ARG_INVHNDL),
1481 		    EC_NATPTR(handle));
1482 		return (NULL);
1483 	}
1484 	return (dlsym_intn(handle, name, clmp, dlmp));
1485 }
1486 
1487 
1488 #pragma weak _dlsym = dlsym
1489 
1490 /*
1491  * External entry for dlsym().  On success, returns the address of the specified
1492  * symbol.  On error returns a null.
1493  */
1494 void *
1495 dlsym(void *handle, const char *name)
1496 {
1497 	int	entry;
1498 	Rt_map	*clmp, *dlmp = NULL;
1499 	void	*addr;
1500 
1501 	entry = enter(0);
1502 
1503 	clmp = _caller(caller(), CL_EXECDEF);
1504 
1505 	addr = dlsym_check(handle, name, clmp, &dlmp);
1506 
1507 	if (entry) {
1508 		if (dlmp)
1509 			is_dep_init(dlmp, clmp);
1510 		leave(LIST(clmp), 0);
1511 	}
1512 	return (addr);
1513 }
1514 
1515 /*
1516  * Core dladdr activity.
1517  */
1518 static void
1519 dladdr_core(Rt_map *almp, void *addr, Dl_info_t *dlip, void **info, int flags)
1520 {
1521 	/*
1522 	 * Set up generic information and any defaults.
1523 	 */
1524 	dlip->dli_fname = PATHNAME(almp);
1525 
1526 	dlip->dli_fbase = (void *)ADDR(almp);
1527 	dlip->dli_sname = NULL;
1528 	dlip->dli_saddr = NULL;
1529 
1530 	/*
1531 	 * Determine the nearest symbol to this address.
1532 	 */
1533 	LM_DLADDR(almp)((ulong_t)addr, almp, dlip, info, flags);
1534 }
1535 
1536 #pragma weak _dladdr = dladdr
1537 
1538 /*
1539  * External entry for dladdr(3dl) and dladdr1(3dl).  Returns an information
1540  * structure that reflects the symbol closest to the address specified.
1541  */
1542 int
1543 dladdr(void *addr, Dl_info_t *dlip)
1544 {
1545 	int	entry, ret;
1546 	Rt_map	*clmp, *almp;
1547 	Lm_list	*clml;
1548 
1549 	entry = enter(0);
1550 
1551 	clmp = _caller(caller(), CL_EXECDEF);
1552 	clml = LIST(clmp);
1553 
1554 	DBG_CALL(Dbg_dl_dladdr(clmp, addr));
1555 
1556 	/*
1557 	 * Use our calling technique to determine what object is associated
1558 	 * with the supplied address.  If a caller can't be determined,
1559 	 * indicate the failure.
1560 	 */
1561 	if ((almp = _caller(addr, CL_NONE)) == NULL) {
1562 		eprintf(clml, ERR_FATAL, MSG_INTL(MSG_ARG_INVADDR),
1563 		    EC_NATPTR(addr));
1564 		ret = 0;
1565 	} else {
1566 		dladdr_core(almp, addr, dlip, 0, 0);
1567 		ret = 1;
1568 	}
1569 
1570 	if (entry)
1571 		leave(clml, 0);
1572 	return (ret);
1573 }
1574 
1575 #pragma weak _dladdr1 = dladdr1
1576 
1577 int
1578 dladdr1(void *addr, Dl_info_t *dlip, void **info, int flags)
1579 {
1580 	int	entry, ret = 1;
1581 	Rt_map	*clmp, *almp;
1582 	Lm_list	*clml;
1583 
1584 	entry = enter(0);
1585 
1586 	clmp = _caller(caller(), CL_EXECDEF);
1587 	clml = LIST(clmp);
1588 
1589 	DBG_CALL(Dbg_dl_dladdr(clmp, addr));
1590 
1591 	/*
1592 	 * Validate any flags.
1593 	 */
1594 	if (flags) {
1595 		int	request;
1596 
1597 		if (((request = (flags & RTLD_DL_MASK)) != RTLD_DL_SYMENT) &&
1598 		    (request != RTLD_DL_LINKMAP)) {
1599 			eprintf(clml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLFLAGS),
1600 			    flags);
1601 			ret = 0;
1602 
1603 		} else if (info == NULL) {
1604 			eprintf(clml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLINFO),
1605 			    flags);
1606 			ret = 0;
1607 		}
1608 	}
1609 
1610 	/*
1611 	 * Use our calling technique to determine what object is associated
1612 	 * with the supplied address.  If a caller can't be determined,
1613 	 * indicate the failure.
1614 	 */
1615 	if (ret) {
1616 		if ((almp = _caller(addr, CL_NONE)) == NULL) {
1617 			eprintf(clml, ERR_FATAL, MSG_INTL(MSG_ARG_INVADDR),
1618 			    EC_NATPTR(addr));
1619 			ret = 0;
1620 		} else
1621 			dladdr_core(almp, addr, dlip, info, flags);
1622 	}
1623 
1624 	if (entry)
1625 		leave(clml, 0);
1626 	return (ret);
1627 }
1628 
1629 /*
1630  * Core dldump activity.
1631  */
1632 static int
1633 dldump_core(Rt_map *clmp, Rt_map *lmp, const char *ipath, const char *opath,
1634     int flags)
1635 {
1636 	Lm_list	*lml = LIST(clmp);
1637 	Addr	addr = 0;
1638 
1639 	/*
1640 	 * Verify any arguments first.
1641 	 */
1642 	if ((opath == NULL) || (opath[0] == '\0') ||
1643 	    ((lmp == NULL) && (ipath[0] == '\0'))) {
1644 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLPATH));
1645 		return (1);
1646 	}
1647 
1648 	/*
1649 	 * If an input file is specified make sure its one of our dependencies
1650 	 * on the main link-map list.  Note, this has really all evolved for
1651 	 * crle(), which uses libcrle.so on an alternative link-map to trigger
1652 	 * dumping objects from the main link-map list.   If we ever want to
1653 	 * dump objects from alternative link-maps, this model is going to
1654 	 * have to be revisited.
1655 	 */
1656 	if (lmp == NULL) {
1657 		if ((lmp = is_so_loaded(&lml_main, ipath, NULL)) == NULL) {
1658 			eprintf(lml, ERR_FATAL, MSG_INTL(MSG_GEN_NOFILE),
1659 			    ipath);
1660 			return (1);
1661 		}
1662 		if (FLAGS(lmp) & FLG_RT_ALTER) {
1663 			eprintf(lml, ERR_FATAL, MSG_INTL(MSG_GEN_ALTER), ipath);
1664 			return (1);
1665 		}
1666 		if (FLAGS(lmp) & FLG_RT_NODUMP) {
1667 			eprintf(lml, ERR_FATAL, MSG_INTL(MSG_GEN_NODUMP),
1668 			    ipath);
1669 			return (1);
1670 		}
1671 	}
1672 
1673 	/*
1674 	 * If the object being dump'ed isn't fixed identify its mapping.
1675 	 */
1676 	if (!(FLAGS(lmp) & FLG_RT_FIXED))
1677 		addr = ADDR(lmp);
1678 
1679 	/*
1680 	 * As rt_dldump() will effectively lazy load the necessary support
1681 	 * libraries, make sure ld.so.1 is initialized for plt relocations.
1682 	 */
1683 	if (elf_rtld_load() == 0)
1684 		return (0);
1685 
1686 	/*
1687 	 * Dump the required image.
1688 	 */
1689 	return (rt_dldump(lmp, opath, flags, addr));
1690 }
1691 
1692 #pragma weak _dldump = dldump
1693 
1694 /*
1695  * External entry for dldump(3c).  Returns 0 on success, non-zero otherwise.
1696  */
1697 int
1698 dldump(const char *ipath, const char *opath, int flags)
1699 {
1700 	int	error, entry;
1701 	Rt_map	*clmp, *lmp;
1702 
1703 	entry = enter(0);
1704 
1705 	clmp = _caller(caller(), CL_EXECDEF);
1706 
1707 	if (ipath) {
1708 		lmp = NULL;
1709 	} else {
1710 		lmp = lml_main.lm_head;
1711 		ipath = NAME(lmp);
1712 	}
1713 
1714 	DBG_CALL(Dbg_dl_dldump(clmp, ipath, opath, flags));
1715 
1716 	error = dldump_core(clmp, lmp, ipath, opath, flags);
1717 
1718 	if (entry)
1719 		leave(LIST(clmp), 0);
1720 	return (error);
1721 }
1722 
1723 /*
1724  * get_linkmap_id() translates Lm_list * pointers to the Link_map id as used by
1725  * the rtld_db and dlmopen() interfaces.  It checks to see if the Link_map is
1726  * one of the primary ones and if so returns it's special token:
1727  *		LM_ID_BASE
1728  *		LM_ID_LDSO
1729  *
1730  * If it's not one of the primary link_map id's it will instead returns a
1731  * pointer to the Lm_list structure which uniquely identifies the Link_map.
1732  */
1733 Lmid_t
1734 get_linkmap_id(Lm_list *lml)
1735 {
1736 	if (lml->lm_flags & LML_FLG_BASELM)
1737 		return (LM_ID_BASE);
1738 	if (lml->lm_flags & LML_FLG_RTLDLM)
1739 		return (LM_ID_LDSO);
1740 
1741 	return ((Lmid_t)lml);
1742 }
1743 
1744 /*
1745  * Set a new deferred dependency name.
1746  */
1747 static int
1748 set_def_need(Lm_list *lml, Dyninfo *dyip, const char *name)
1749 {
1750 	/*
1751 	 * If this dependency has already been established, then this dlinfo()
1752 	 * call is too late.
1753 	 */
1754 	if (dyip->di_info) {
1755 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_DEF_DEPLOADED),
1756 		    dyip->di_name);
1757 		return (-1);
1758 	}
1759 
1760 	/*
1761 	 * Assign the new dependency name.
1762 	 */
1763 	DBG_CALL(Dbg_file_deferred(lml, dyip->di_name, name));
1764 	dyip->di_flags |= FLG_DI_DEF_DONE;
1765 	dyip->di_name = name;
1766 	return (0);
1767 }
1768 
1769 /*
1770  * Extract information for a dlopen() handle.
1771  */
1772 static int
1773 dlinfo_core(void *handle, int request, void *p, Rt_map *clmp)
1774 {
1775 	Conv_inv_buf_t	inv_buf;
1776 	char		*handlename;
1777 	Lm_list		*lml = LIST(clmp);
1778 	Rt_map		*lmp = NULL;
1779 
1780 	/*
1781 	 * Determine whether a handle is provided.  A handle isn't needed for
1782 	 * all operations, but it is validated here for the initial diagnostic.
1783 	 */
1784 	if (handle == RTLD_SELF) {
1785 		lmp = clmp;
1786 	} else {
1787 		Grp_hdl	*ghp = (Grp_hdl *)handle;
1788 
1789 		if (hdl_validate(ghp))
1790 			lmp = ghp->gh_ownlmp;
1791 	}
1792 	if (lmp) {
1793 		handlename = NAME(lmp);
1794 	} else {
1795 		(void) conv_invalid_val(&inv_buf, EC_NATPTR(handle), 0);
1796 		handlename = inv_buf.buf;
1797 	}
1798 
1799 	DBG_CALL(Dbg_dl_dlinfo(clmp, handlename, request, p));
1800 
1801 	/*
1802 	 * Validate the request and return buffer.
1803 	 */
1804 	if ((request > RTLD_DI_MAX) || (p == NULL)) {
1805 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLVAL));
1806 		return (-1);
1807 	}
1808 
1809 	/*
1810 	 * Return configuration cache name and address.
1811 	 */
1812 	if (request == RTLD_DI_CONFIGADDR) {
1813 		Dl_info_t	*dlip = (Dl_info_t *)p;
1814 
1815 		if ((config->c_name == NULL) || (config->c_bgn == 0) ||
1816 		    (config->c_end == 0)) {
1817 			eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_NOCONFIG));
1818 			return (-1);
1819 		}
1820 		dlip->dli_fname = config->c_name;
1821 		dlip->dli_fbase = (void *)config->c_bgn;
1822 		return (0);
1823 	}
1824 
1825 	/*
1826 	 * Return profiled object name (used by ldprof audit library).
1827 	 */
1828 	if (request == RTLD_DI_PROFILENAME) {
1829 		if (profile_name == NULL) {
1830 			eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_NOPROFNAME));
1831 			return (-1);
1832 		}
1833 
1834 		*(const char **)p = profile_name;
1835 		return (0);
1836 	}
1837 	if (request == RTLD_DI_PROFILEOUT) {
1838 		/*
1839 		 * If a profile destination directory hasn't been specified
1840 		 * provide a default.
1841 		 */
1842 		if (profile_out == NULL)
1843 			profile_out = MSG_ORIG(MSG_PTH_VARTMP);
1844 
1845 		*(const char **)p = profile_out;
1846 		return (0);
1847 	}
1848 
1849 	/*
1850 	 * Obtain or establish a termination signal.
1851 	 */
1852 	if (request == RTLD_DI_GETSIGNAL) {
1853 		*(int *)p = killsig;
1854 		return (0);
1855 	}
1856 
1857 	if (request == RTLD_DI_SETSIGNAL) {
1858 		sigset_t	set;
1859 		int		sig = *(int *)p;
1860 
1861 		/*
1862 		 * Determine whether the signal is in range.
1863 		 */
1864 		(void) sigfillset(&set);
1865 		if (sigismember(&set, sig) != 1) {
1866 			eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_INVSIG), sig);
1867 			return (-1);
1868 		}
1869 
1870 		killsig = sig;
1871 		return (0);
1872 	}
1873 
1874 	/*
1875 	 * For any other request a link-map is required.  Verify the handle.
1876 	 */
1877 	if (lmp == NULL) {
1878 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_INVHNDL),
1879 		    EC_NATPTR(handle));
1880 		return (-1);
1881 	}
1882 
1883 	/*
1884 	 * Obtain the process arguments, environment and auxv.  Note, as the
1885 	 * environment can be modified by the user (putenv(3c)), reinitialize
1886 	 * the environment pointer on each request.
1887 	 */
1888 	if (request == RTLD_DI_ARGSINFO) {
1889 		Dl_argsinfo_t	*aip = (Dl_argsinfo_t *)p;
1890 		Lm_list		*lml = LIST(lmp);
1891 
1892 		*aip = argsinfo;
1893 		if (lml->lm_flags & LML_FLG_ENVIRON)
1894 			aip->dla_envp = *(lml->lm_environ);
1895 
1896 		return (0);
1897 	}
1898 
1899 	/*
1900 	 * Return Lmid_t of the Link-Map list that the specified object is
1901 	 * loaded on.
1902 	 */
1903 	if (request == RTLD_DI_LMID) {
1904 		*(Lmid_t *)p = get_linkmap_id(LIST(lmp));
1905 		return (0);
1906 	}
1907 
1908 	/*
1909 	 * Return a pointer to the Link-Map structure associated with the
1910 	 * specified object.
1911 	 */
1912 	if (request == RTLD_DI_LINKMAP) {
1913 		*(Link_map **)p = (Link_map *)lmp;
1914 		return (0);
1915 	}
1916 
1917 	/*
1918 	 * Return search path information, or the size of the buffer required
1919 	 * to store the information.
1920 	 */
1921 	if ((request == RTLD_DI_SERINFO) || (request == RTLD_DI_SERINFOSIZE)) {
1922 		Spath_desc	sd = { search_rules, NULL, 0 };
1923 		Pdesc		*pdp;
1924 		Dl_serinfo_t	*info;
1925 		Dl_serpath_t	*path;
1926 		char		*strs;
1927 		size_t		size = sizeof (Dl_serinfo_t);
1928 		uint_t		cnt = 0;
1929 
1930 		info = (Dl_serinfo_t *)p;
1931 		path = &info->dls_serpath[0];
1932 		strs = (char *)&info->dls_serpath[info->dls_cnt];
1933 
1934 		/*
1935 		 * Traverse search path entries for this object.
1936 		 */
1937 		while ((pdp = get_next_dir(&sd, lmp, 0)) != NULL) {
1938 			size_t	_size;
1939 
1940 			if (pdp->pd_pname == NULL)
1941 				continue;
1942 
1943 			/*
1944 			 * If configuration information exists, it's possible
1945 			 * this path has been identified as non-existent, if so
1946 			 * ignore it.
1947 			 */
1948 			if (pdp->pd_info) {
1949 				Rtc_obj	*dobj = (Rtc_obj *)pdp->pd_info;
1950 				if (dobj->co_flags & RTC_OBJ_NOEXIST)
1951 					continue;
1952 			}
1953 
1954 			/*
1955 			 * Keep track of search path count and total info size.
1956 			 */
1957 			if (cnt++)
1958 				size += sizeof (Dl_serpath_t);
1959 			_size = pdp->pd_plen + 1;
1960 			size += _size;
1961 
1962 			if (request == RTLD_DI_SERINFOSIZE)
1963 				continue;
1964 
1965 			/*
1966 			 * If we're filling in search path information, confirm
1967 			 * there's sufficient space.
1968 			 */
1969 			if (size > info->dls_size) {
1970 				eprintf(lml, ERR_FATAL,
1971 				    MSG_INTL(MSG_ARG_SERSIZE),
1972 				    EC_OFF(info->dls_size));
1973 				return (-1);
1974 			}
1975 			if (cnt > info->dls_cnt) {
1976 				eprintf(lml, ERR_FATAL,
1977 				    MSG_INTL(MSG_ARG_SERCNT), info->dls_cnt);
1978 				return (-1);
1979 			}
1980 
1981 			/*
1982 			 * Append the path to the information buffer.
1983 			 */
1984 			(void) strcpy(strs, pdp->pd_pname);
1985 			path->dls_name = strs;
1986 			path->dls_flags = (pdp->pd_flags & LA_SER_MASK);
1987 
1988 			strs = strs + _size;
1989 			path++;
1990 		}
1991 
1992 		/*
1993 		 * If we're here to size the search buffer fill it in.
1994 		 */
1995 		if (request == RTLD_DI_SERINFOSIZE) {
1996 			info->dls_size = size;
1997 			info->dls_cnt = cnt;
1998 		}
1999 
2000 		return (0);
2001 	}
2002 
2003 	/*
2004 	 * Return the origin of the object associated with this link-map.
2005 	 * Basically return the dirname(1) of the objects fullpath.
2006 	 */
2007 	if (request == RTLD_DI_ORIGIN) {
2008 		char	*str = (char *)p;
2009 
2010 		(void) strncpy(str, ORIGNAME(lmp), DIRSZ(lmp));
2011 		str += DIRSZ(lmp);
2012 		*str = '\0';
2013 
2014 		return (0);
2015 	}
2016 
2017 	/*
2018 	 * Return the number of object mappings, or the mapping information for
2019 	 * this object.
2020 	 */
2021 	if (request == RTLD_DI_MMAPCNT) {
2022 		uint_t	*cnt = (uint_t *)p;
2023 
2024 		*cnt = MMAPCNT(lmp);
2025 		return (0);
2026 	}
2027 	if (request == RTLD_DI_MMAPS) {
2028 		Dl_mapinfo_t	*mip = (Dl_mapinfo_t *)p;
2029 
2030 		if (mip->dlm_acnt && mip->dlm_maps) {
2031 			uint_t	cnt = 0;
2032 
2033 			while ((cnt < mip->dlm_acnt) && (cnt < MMAPCNT(lmp))) {
2034 				mip->dlm_maps[cnt] = MMAPS(lmp)[cnt];
2035 				cnt++;
2036 			}
2037 			mip->dlm_rcnt = cnt;
2038 		}
2039 		return (0);
2040 	}
2041 
2042 	/*
2043 	 * Assign a new dependency name to a deferred dependency.
2044 	 */
2045 	if ((request == RTLD_DI_DEFERRED) ||
2046 	    (request == RTLD_DI_DEFERRED_SYM)) {
2047 		Dl_definfo_t	*dfip = (Dl_definfo_t *)p;
2048 		Dyninfo		*dyip;
2049 		const char	*dname, *rname;
2050 
2051 		/*
2052 		 * Verify the names.
2053 		 */
2054 		if ((dfip->dld_refname == NULL) ||
2055 		    (dfip->dld_depname == NULL)) {
2056 			eprintf(LIST(clmp), ERR_FATAL,
2057 			    MSG_INTL(MSG_ARG_ILLNAME));
2058 			return (-1);
2059 		}
2060 
2061 		dname = dfip->dld_depname;
2062 		rname = dfip->dld_refname;
2063 
2064 		/*
2065 		 * A deferred dependency can be determined by referencing a
2066 		 * symbol family member that is associated to the dependency,
2067 		 * or by looking for the dependency by its name.
2068 		 */
2069 		if (request == RTLD_DI_DEFERRED_SYM) {
2070 			Slookup		sl;
2071 			Sresult		sr;
2072 			uint_t		binfo;
2073 			Syminfo		*sip;
2074 
2075 			/*
2076 			 * Lookup the symbol in the associated object.
2077 			 */
2078 			SLOOKUP_INIT(sl, rname, lmp, lmp, ld_entry_cnt,
2079 			    elf_hash(rname), 0, 0, 0, LKUP_SYMNDX);
2080 			SRESULT_INIT(sr, rname);
2081 			if (sym_lookup_in_caller(clmp, &sl, &sr,
2082 			    &binfo) == NULL) {
2083 				eprintf(LIST(clmp), ERR_FATAL,
2084 				    MSG_INTL(MSG_DEF_NOSYMFOUND), rname);
2085 				return (-1);
2086 			}
2087 
2088 			/*
2089 			 * Use the symbols index to reference the Syminfo entry
2090 			 * and thus find the associated dependency.
2091 			 */
2092 			if (sl.sl_rsymndx && ((sip = SYMINFO(clmp)) != NULL)) {
2093 				/* LINTED */
2094 				sip = (Syminfo *)((char *)sip +
2095 				    (sl.sl_rsymndx * SYMINENT(lmp)));
2096 
2097 				if ((sip->si_flags & SYMINFO_FLG_DEFERRED) &&
2098 				    (sip->si_boundto < SYMINFO_BT_LOWRESERVE) &&
2099 				    ((dyip = DYNINFO(lmp)) != NULL)) {
2100 					dyip += sip->si_boundto;
2101 
2102 					if (!(dyip->di_flags & FLG_DI_IGNORE))
2103 						return (set_def_need(lml,
2104 						    dyip, dname));
2105 				}
2106 			}
2107 
2108 			/*
2109 			 * No deferred symbol found.
2110 			 */
2111 			eprintf(LIST(clmp), ERR_FATAL,
2112 			    MSG_INTL(MSG_DEF_NOSYMFOUND), rname);
2113 			return (-1);
2114 
2115 		} else {
2116 			Dyn	*dyn;
2117 
2118 			/*
2119 			 * Using the target objects dependency information, find
2120 			 * the associated deferred dependency.
2121 			 */
2122 			for (dyn = DYN(lmp), dyip = DYNINFO(lmp);
2123 			    !(dyip->di_flags & FLG_DI_IGNORE); dyn++, dyip++) {
2124 				const char	*oname;
2125 
2126 				if ((dyip->di_flags & FLG_DI_DEFERRED) == 0)
2127 					continue;
2128 
2129 				if (strcmp(rname, dyip->di_name) == 0)
2130 					return (set_def_need(lml, dyip, dname));
2131 
2132 				/*
2133 				 * If this dependency name has been changed by
2134 				 * a previous dlinfo(), check the original
2135 				 * dynamic entry string.  The user might be
2136 				 * attempting to re-change an entry using the
2137 				 * original name as the reference.
2138 				 */
2139 				if ((dyip->di_flags & FLG_DI_DEF_DONE) == 0)
2140 					continue;
2141 
2142 				oname = STRTAB(lmp) + dyn->d_un.d_val;
2143 				if (strcmp(rname, oname) == 0)
2144 					return (set_def_need(lml, dyip, dname));
2145 			}
2146 
2147 			/*
2148 			 * No deferred dependency found.
2149 			 */
2150 			eprintf(lml, ERR_FATAL, MSG_INTL(MSG_DEF_NODEPFOUND),
2151 			    rname);
2152 			return (-1);
2153 		}
2154 	}
2155 	return (0);
2156 }
2157 
2158 #pragma weak _dlinfo = dlinfo
2159 
2160 /*
2161  * External entry for dlinfo(3dl).
2162  */
2163 int
2164 dlinfo(void *handle, int request, void *p)
2165 {
2166 	int	error, entry;
2167 	Rt_map	*clmp;
2168 
2169 	entry = enter(0);
2170 
2171 	clmp = _caller(caller(), CL_EXECDEF);
2172 
2173 	error = dlinfo_core(handle, request, p, clmp);
2174 
2175 	if (entry)
2176 		leave(LIST(clmp), 0);
2177 	return (error);
2178 }
2179 
2180 /*
2181  * GNU defined function to iterate through the program headers for all
2182  * currently loaded dynamic objects. The caller supplies a callback function
2183  * which is called for each object.
2184  *
2185  * entry:
2186  *	callback - Callback function to call. The arguments to the callback
2187  *		function are:
2188  *		info - Address of dl_phdr_info structure
2189  *		size - sizeof (struct dl_phdr_info)
2190  *		data - Caller supplied value.
2191  *	data - Value supplied by caller, which is passed to callback without
2192  *		examination.
2193  *
2194  * exit:
2195  *	callback is called for each dynamic ELF object in the process address
2196  *	space, halting when a non-zero value is returned, or when the last
2197  *	object has been processed. The return value from the last call
2198  *	to callback is returned.
2199  *
2200  * note:
2201  *	The Linux implementation has added additional fields to the
2202  *	dl_phdr_info structure over time. The callback function is
2203  *	supposed to use the size field to determine which fields are
2204  *	present, and to avoid attempts to access non-existent fields.
2205  *	We have added those fields that are compatible with Solaris, and
2206  *	which are used by GNU C++ (g++) runtime exception handling support.
2207  *
2208  * note:
2209  *	We issue a callback for every ELF object mapped into the process
2210  *	address space at the time this routine is entered. These callbacks
2211  *	are arbitrary functions that can do anything, including possibly
2212  *	causing new objects to be mapped into the process, or unmapped.
2213  *	This complicates matters:
2214  *
2215  *	-	Adding new objects can cause the alists to be reallocated
2216  *		or for contents to move. This can happen explicitly via
2217  *		dlopen(), or implicitly via lazy loading. One might consider
2218  *		simply banning dlopen from a callback, but lazy loading must
2219  *		be allowed, in which case there's no reason to ban dlopen().
2220  *
2221  *	-	Removing objects can leave us holding references to freed
2222  *		memory that must not be accessed, and can cause the list
2223  *		items to move in a way that would cause us to miss reporting
2224  *		one, or double report others.
2225  *
2226  *	-	We cannot allocate memory to build a separate data structure,
2227  *		because the interface to dl_iterate_phdr() does not have a
2228  *		way to communicate allocation errors back to the caller.
2229  *		Even if we could, it would be difficult to do so efficiently.
2230  *
2231  *	-	It is possible for dl_iterate_phdr() to be called recursively
2232  *		from a callback, and there is no way for us to detect or manage
2233  *		this effectively, particularly as the user might use longjmp()
2234  *		to skip past us on return. Hence, we must be reentrant
2235  *		(stateless), further precluding the option of building a
2236  *		separate data structure.
2237  *
2238  *	Despite these constraints, we are able to traverse the link-map
2239  *	lists safely:
2240  *
2241  *	-	Once interposer (preload) objects have been processed at
2242  *		startup, we know that new objects are always placed at the
2243  *		end of the list. Hence, if we are reading a list when that
2244  *		happens, the new object will not alter the part of the list
2245  *		that we've already processed.
2246  *
2247  *	-	The alist _TRAVERSE macros recalculate the address of the
2248  *		current item from scratch on each iteration, rather than
2249  *		incrementing a pointer. Hence, alist additions that occur
2250  *		in mid-traverse will not cause confusion.
2251  *
2252  * 	There is one limitation: We cannot continue operation if an object
2253  *	is removed from the process from within a callback. We detect when
2254  *	this happens and return immediately with a -1 return value.
2255  *
2256  * note:
2257  *	As currently implemented, if a callback causes an object to be loaded,
2258  *	that object may or may not be reported by the current invocation of
2259  *	dl_iterate_phdr(), based on whether or not we have already processed
2260  *	the link-map list that receives it. If we want to prevent this, it
2261  *	can be done efficiently by associating the current value of cnt_map
2262  *	with each new Rt_map entered into the system. Then this function can
2263  *	use that to detect and skip new objects that enter the system in
2264  *	mid-iteration. However, the Linux documentation is ambiguous on whether
2265  *	this is necessary, and it does not appear to matter in practice.
2266  *	We have therefore chosen not to do so at this time.
2267  */
2268 int
2269 dl_iterate_phdr(int (*callback)(struct dl_phdr_info *, size_t, void *),
2270     void *data)
2271 {
2272 	struct dl_phdr_info	info;
2273 	u_longlong_t		l_cnt_map = cnt_map;
2274 	u_longlong_t		l_cnt_unmap = cnt_unmap;
2275 	Lm_list			*lml, *clml;
2276 	Lm_cntl			*lmc;
2277 	Rt_map			*lmp, *clmp;
2278 	Aliste			idx1, idx2;
2279 	Ehdr			*ehdr;
2280 	int			ret = 0;
2281 	int			entry;
2282 
2283 	entry = enter(0);
2284 	clmp = _caller(caller(), CL_EXECDEF);
2285 	clml = LIST(clmp);
2286 
2287 	DBG_CALL(Dbg_dl_iphdr_enter(clmp, cnt_map, cnt_unmap));
2288 
2289 	/* Issue a callback for each ELF object in the process */
2290 	for (APLIST_TRAVERSE(dynlm_list, idx1, lml)) {
2291 		for (ALIST_TRAVERSE(lml->lm_lists, idx2, lmc)) {
2292 			for (lmp = lmc->lc_head; lmp; lmp = NEXT_RT_MAP(lmp)) {
2293 #if defined(_sparc) && !defined(_LP64)
2294 				/*
2295 				 * On 32-bit sparc, the possibility exists that
2296 				 * this object is not ELF.
2297 				 */
2298 				if (THIS_IS_NOT_ELF(lmp))
2299 					continue;
2300 #endif
2301 				/* Prepare the object information structure */
2302 				ehdr = (Ehdr *) ADDR(lmp);
2303 				info.dlpi_addr = (ehdr->e_type == ET_EXEC) ?
2304 				    0 : ADDR(lmp);
2305 				info.dlpi_name = lmp->rt_pathname;
2306 				info.dlpi_phdr = (Phdr *)
2307 				    (ADDR(lmp) + ehdr->e_phoff);
2308 				info.dlpi_phnum = ehdr->e_phnum;
2309 				info.dlpi_adds = cnt_map;
2310 				info.dlpi_subs = cnt_unmap;
2311 
2312 				/* Issue the callback */
2313 				DBG_CALL(Dbg_dl_iphdr_callback(clml, &info));
2314 				leave(clml, thr_flg_reenter);
2315 				ret = (* callback)(&info, sizeof (info), data);
2316 				(void) enter(thr_flg_reenter);
2317 
2318 				/* Return immediately on non-zero result */
2319 				if (ret != 0)
2320 					goto done;
2321 
2322 				/* Adapt to object mapping changes */
2323 				if ((cnt_map == l_cnt_map) &&
2324 				    (cnt_unmap == l_cnt_unmap))
2325 					continue;
2326 
2327 				DBG_CALL(Dbg_dl_iphdr_mapchange(clml, cnt_map,
2328 				    cnt_unmap));
2329 
2330 				/* Stop if an object was unmapped */
2331 				if (cnt_unmap == l_cnt_unmap) {
2332 					l_cnt_map = cnt_map;
2333 					continue;
2334 				}
2335 
2336 				ret = -1;
2337 				DBG_CALL(Dbg_dl_iphdr_unmap_ret(clml));
2338 				goto done;
2339 			}
2340 		}
2341 	}
2342 
2343 done:
2344 	if (entry)
2345 		leave(LIST(clmp), 0);
2346 	return (ret);
2347 }
2348