xref: /titanic_50/usr/src/cmd/sgs/rtld/common/dlfcns.c (revision 7c64d3750da7fda7e450b8f9b0b963905ded6379)
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 2008 Sun Microsystems, Inc.  All rights reserved.
27  * Use is subject to license terms.
28  */
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 /*
33  * Programmatic interface to the run_time linker.
34  */
35 #include	"_synonyms.h"
36 
37 #include	<sys/debug.h>
38 #include	<stdio.h>
39 #include	<string.h>
40 #include	<dlfcn.h>
41 #include	<synch.h>
42 #include	<limits.h>
43 #include	<debug.h>
44 #include	"_rtld.h"
45 #include	"_audit.h"
46 #include	"_elf.h"
47 #include	"msg.h"
48 
49 /*
50  * Determine who called us - given a pc determine in which object it resides.
51  *
52  * For dlopen() the link map of the caller must be passed to load_so() so that
53  * the appropriate search rules (4.x or 5.0) are used to locate any
54  * dependencies.  Also, if we've been called from a 4.x module it may be
55  * necessary to fix the specified pathname so that it conforms with the 5.0 elf
56  * rules.
57  *
58  * For dlsym() the link map of the caller is used to determine RTLD_NEXT
59  * requests, together with requests based off of a dlopen(0).
60  * For dladdr() this routines provides a generic means of scanning all loaded
61  * segments.
62  */
63 Rt_map *
64 _caller(caddr_t cpc, int flags)
65 {
66 	Lm_list *	lml;
67 	Listnode *	lnp;
68 
69 	for (LIST_TRAVERSE(&dynlm_list, lnp, lml)) {
70 		Aliste	idx;
71 		Lm_cntl	*lmc;
72 
73 		for (ALIST_TRAVERSE(lml->lm_lists, idx, lmc)) {
74 			Rt_map	*lmp;
75 
76 			for (lmp = lmc->lc_head; lmp;
77 			    lmp = (Rt_map *)NEXT(lmp)) {
78 				Mmap	*mmap;
79 
80 				/*
81 				 * Traverse this objects mappings testing
82 				 * whether the pc falls within its range.
83 				 */
84 				for (mmap = MMAPS(lmp); mmap->m_vaddr; mmap++) {
85 					if ((cpc >= mmap->m_vaddr) && (cpc <
86 					    (mmap->m_vaddr + mmap->m_msize)))
87 						return (lmp);
88 				}
89 			}
90 		}
91 	}
92 
93 	/*
94 	 * No mapping can be determined.  If asked for a default, assume this
95 	 * is from the executable.
96 	 */
97 	if (flags & CL_EXECDEF)
98 		return ((Rt_map *)lml_main.lm_head);
99 
100 	return (0);
101 }
102 
103 #pragma weak dlerror = _dlerror
104 
105 /*
106  * External entry for dlerror(3dl).  Returns a pointer to the string describing
107  * the last occurring error.  The last occurring error is cleared.
108  */
109 char *
110 _dlerror()
111 {
112 	char	*error;
113 	Rt_map	*clmp;
114 	int	entry;
115 
116 	entry = enter();
117 
118 	clmp = _caller(caller(), CL_EXECDEF);
119 
120 	error = lasterr;
121 	lasterr = (char *)0;
122 
123 	if (entry)
124 		leave(LIST(clmp));
125 	return (error);
126 }
127 
128 /*
129  * Add a dependency as a group descriptor to a group handle.  Returns 0 on
130  * failure, ALE_EXISTS if the dependency already exists, or ALE_CREATE if it
131  * is newly created.
132  */
133 int
134 hdl_add(Grp_hdl *ghp, Rt_map *lmp, uint_t flags)
135 {
136 	Grp_desc	*gdp;
137 	Aliste		idx;
138 	int		found = ALE_CREATE;
139 	uint_t		oflags;
140 
141 	/*
142 	 * Make sure this dependency hasn't already been recorded.
143 	 */
144 	for (ALIST_TRAVERSE(ghp->gh_depends, idx, gdp)) {
145 		if (gdp->gd_depend == lmp) {
146 			found = ALE_EXISTS;
147 			break;
148 		}
149 	}
150 
151 	if (found == ALE_CREATE) {
152 		Grp_desc	gd;
153 
154 		/*
155 		 * Create a new handle descriptor.
156 		 */
157 		gd.gd_depend = lmp;
158 		gd.gd_flags = 0;
159 
160 		/*
161 		 * Indicate this object is a part of this handles group.
162 		 */
163 		if (aplist_append(&GROUPS(lmp), ghp,
164 		    AL_CNT_GROUPS) == 0)
165 			return (0);
166 
167 		/*
168 		 * Append the new dependency to this handle.
169 		 */
170 		if ((gdp = alist_append(&ghp->gh_depends, &gd,
171 		    sizeof (Grp_desc), AL_CNT_DEPENDS)) == 0)
172 			return (0);
173 	}
174 
175 	oflags = gdp->gd_flags;
176 	gdp->gd_flags |= flags;
177 
178 	if (DBG_ENABLED) {
179 		if (found == ALE_CREATE)
180 			DBG_CALL(Dbg_file_hdl_action(ghp, lmp, DBG_DEP_ADD,
181 			    gdp->gd_flags));
182 		else if (gdp->gd_flags != oflags)
183 			DBG_CALL(Dbg_file_hdl_action(ghp, lmp, DBG_DEP_UPDATE,
184 			    gdp->gd_flags));
185 	}
186 	return (found);
187 }
188 
189 /*
190  * Allocate a handle and record its existence on the handle list for future
191  * verification.
192  */
193 Grp_hdl *
194 hdl_alloc()
195 {
196 	Grp_hdl	*ghp;
197 	uint_t	ndx;
198 
199 	if ((ghp = calloc(sizeof (Grp_hdl), 1)) == 0)
200 		return (0);
201 
202 	/* LINTED */
203 	ndx = (uintptr_t)ghp % HDLIST_SZ;
204 
205 	if (list_append(&hdl_list[ndx], ghp) == 0) {
206 		free(ghp);
207 		return (0);
208 	}
209 	return (ghp);
210 }
211 
212 /*
213  * Create a handle.
214  */
215 Grp_hdl *
216 hdl_create(Lm_list *lml, Rt_map *nlmp, Rt_map *clmp, uint_t hflags,
217     uint_t ndflags, uint_t cdflags)
218 {
219 	Grp_hdl	*ghp = 0, *_ghp;
220 	APlist	**alpp;
221 	Aliste	idx;
222 
223 	/*
224 	 * For dlopen(0) the handle is maintained as part of the link-map list,
225 	 * otherwise it is associated with the referenced link-map.
226 	 */
227 	if (hflags & GPH_ZERO)
228 		alpp = &(lml->lm_handle);
229 	else
230 		alpp = &(HANDLES(nlmp));
231 
232 	/*
233 	 * Objects can contain multiple handles depending on the handle flags
234 	 * supplied.  Most RTLD flags pertain to the object itself and the
235 	 * bindings that it can achieve.  Multiple handles for these flags
236 	 * don't make sense.  But if the flag determines how the handle might
237 	 * be used, then multiple handles may exist.  Presently this only makes
238 	 * sense for RTLD_FIRST.  Determine if an appropriate handle already
239 	 * exists.
240 	 */
241 	for (APLIST_TRAVERSE(*alpp, idx, _ghp)) {
242 		if ((_ghp->gh_flags & GPH_FIRST) == (hflags & GPH_FIRST)) {
243 			ghp = _ghp;
244 			break;
245 		}
246 	}
247 
248 	if (ghp == 0) {
249 		DBG_CALL(Dbg_file_hdl_title(DBG_HDL_CREATE));
250 
251 		/*
252 		 * If this is the first dlopen() request for this handle
253 		 * allocate and initialize a new handle.
254 		 */
255 		if ((ghp = hdl_alloc()) == 0)
256 			return (0);
257 
258 		if (aplist_append(alpp, ghp, AL_CNT_GROUPS) == 0)
259 			return (0);
260 
261 		ghp->gh_refcnt = 1;
262 		ghp->gh_flags = hflags;
263 
264 		/*
265 		 * A dlopen(0) handle is identified by the GPH_ZERO flag, the
266 		 * head of the link-map list is defined as the owner.  There is
267 		 * no need to maintain a list of dependencies, for when this
268 		 * handle is used (for dlsym()) a dynamic search through the
269 		 * entire link-map list provides for searching all objects with
270 		 * GLOBAL visibility.
271 		 */
272 		if (hflags & GPH_ZERO) {
273 			ghp->gh_ownlmp = lml->lm_head;
274 			ghp->gh_ownlml = lml;
275 		} else {
276 			ghp->gh_ownlmp = nlmp;
277 			ghp->gh_ownlml = LIST(nlmp);
278 
279 			if (hdl_add(ghp, nlmp, ndflags) == 0)
280 				return (0);
281 
282 			/*
283 			 * Indicate that a local group now exists.  This state
284 			 * allows singleton searches to be optimized.
285 			 */
286 			if ((hflags & GPH_LDSO) == 0)
287 				LIST(nlmp)->lm_flags |= LML_FLG_GROUPSEXIST;
288 		}
289 	} else {
290 		/*
291 		 * If a handle already exists, bump its reference count.
292 		 *
293 		 * If the previous reference count was 0, then this is a handle
294 		 * that an earlier call to dlclose() was unable to remove.  Such
295 		 * handles are put on the orphan list.  As this handle is back
296 		 * in use, it must be removed from the orphan list.
297 		 *
298 		 * Note, handles associated with a link-map list itself (i.e.
299 		 * dlopen(0)) can have a reference count of 0.  However, these
300 		 * handles are never deleted, and therefore are never moved to
301 		 * the orphan list.
302 		 */
303 		if ((ghp->gh_refcnt++ == 0) &&
304 		    ((ghp->gh_flags & GPH_ZERO) == 0)) {
305 			uint_t	ndx;
306 
307 			/* LINTED */
308 			ndx = (uintptr_t)ghp % HDLIST_SZ;
309 
310 			list_delete(&hdl_list[HDLIST_ORP], ghp);
311 			(void) list_append(&hdl_list[ndx], ghp);
312 
313 			if (DBG_ENABLED) {
314 				Aliste		idx;
315 				Grp_desc	*gdp;
316 
317 				DBG_CALL(Dbg_file_hdl_title(DBG_HDL_REINST));
318 				for (ALIST_TRAVERSE(ghp->gh_depends, idx, gdp))
319 					DBG_CALL(Dbg_file_hdl_action(ghp,
320 					    gdp->gd_depend, DBG_DEP_REINST, 0));
321 			}
322 		}
323 	}
324 
325 	/*
326 	 * Keep track of the parent (caller).  As this object could be opened
327 	 * by different parents, this processing is carried out every time a
328 	 * handle is requested.
329 	 */
330 	if (clmp && (hdl_add(ghp, clmp, cdflags) == 0))
331 		return (0);
332 
333 	return (ghp);
334 }
335 
336 /*
337  * Initialize a handle that has been created for an object that is already
338  * loaded.  The handle is initialized with the present dependencies of that
339  * object.  Once this initialization has occurred, any new objects that might
340  * be loaded as dependencies (lazy-loading) are added to the handle as each new
341  * object is loaded.
342  */
343 int
344 hdl_initialize(Grp_hdl *ghp, Rt_map *nlmp, int mode, int promote)
345 {
346 	Aliste		idx;
347 	Grp_desc	*gdp;
348 
349 	/*
350 	 * If the handle has already been initialized, and the initial object's
351 	 * mode hasn't been promoted, there's no need to recompute the modes of
352 	 * any dependencies.  If the object we've added has just been opened,
353 	 * the objects dependencies will not yet have been processed.  These
354 	 * dependencies will be added on later calls to load_one().  Otherwise,
355 	 * this object already exists, so add all of its dependencies to the
356 	 * handle were operating on.
357 	 */
358 	if (((ghp->gh_flags & GPH_INITIAL) && (promote == 0)) ||
359 	    ((FLAGS(nlmp) & FLG_RT_ANALYZED) == 0)) {
360 		ghp->gh_flags |= GPH_INITIAL;
361 		return (1);
362 	}
363 
364 	DBG_CALL(Dbg_file_hdl_title(DBG_HDL_ADD));
365 	for (ALIST_TRAVERSE(ghp->gh_depends, idx, gdp)) {
366 		Rt_map *	lmp = gdp->gd_depend;
367 		Aliste		idx1;
368 		Bnd_desc	*bdp;
369 
370 		/*
371 		 * If this dependency doesn't indicate that its dependencies
372 		 * should be added to a handle, ignore it.  This case identifies
373 		 * a parent of a dlopen(RTLD_PARENT) request.
374 		 */
375 		if ((gdp->gd_flags & GPD_ADDEPS) == 0)
376 			continue;
377 
378 		for (APLIST_TRAVERSE(DEPENDS(lmp), idx1, bdp)) {
379 			Rt_map		*dlmp = bdp->b_depend;
380 
381 			if ((bdp->b_flags & BND_NEEDED) == 0)
382 				continue;
383 
384 			if (hdl_add(ghp, dlmp,
385 			    (GPD_DLSYM | GPD_RELOC | GPD_ADDEPS)) == 0)
386 				return (0);
387 
388 			(void) update_mode(dlmp, MODE(dlmp), mode);
389 		}
390 	}
391 	ghp->gh_flags |= GPH_INITIAL;
392 	return (1);
393 }
394 
395 /*
396  * Sanity check a program-provided handle.
397  */
398 static int
399 hdl_validate(Grp_hdl *ghp)
400 {
401 	Listnode	*lnp;
402 	Grp_hdl		*lghp;
403 	uint_t		ndx;
404 
405 	/* LINTED */
406 	ndx = (uintptr_t)ghp % HDLIST_SZ;
407 
408 	for (LIST_TRAVERSE(&hdl_list[ndx], lnp, lghp)) {
409 		if ((lghp == ghp) && (ghp->gh_refcnt != 0))
410 			return (1);
411 	}
412 	return (0);
413 }
414 
415 /*
416  * Core dlclose activity.
417  */
418 int
419 dlclose_core(Grp_hdl *ghp, Rt_map *clmp, Lm_list *lml)
420 {
421 	int	error;
422 
423 	/*
424 	 * If we're already at atexit() there's no point processing further,
425 	 * all objects have already been tsorted for fini processing.
426 	 */
427 	if ((rtld_flags & RT_FL_ATEXIT) != 0)
428 		return (0);
429 
430 	/*
431 	 * Diagnose what we're up to.
432 	 */
433 	if (ghp->gh_flags & GPH_ZERO) {
434 		DBG_CALL(Dbg_file_dlclose(LIST(clmp), MSG_ORIG(MSG_STR_ZERO),
435 		    DBG_DLCLOSE_IGNORE));
436 	} else {
437 		DBG_CALL(Dbg_file_dlclose(LIST(clmp), NAME(ghp->gh_ownlmp),
438 		    DBG_DLCLOSE_NULL));
439 	}
440 
441 
442 	/*
443 	 * Decrement reference count of this object.
444 	 */
445 	if (--(ghp->gh_refcnt))
446 		return (0);
447 
448 	/*
449 	 * If this handle is special (dlopen(0)), then leave it around - it
450 	 * has little overhead.
451 	 */
452 	if (ghp->gh_flags & GPH_ZERO)
453 		return (0);
454 
455 	/*
456 	 * This handle is no longer being referenced, remove it.  If this handle
457 	 * is part of an alternative link-map list, determine if the whole list
458 	 * can be removed also.
459 	 */
460 	error = remove_hdl(ghp, clmp, 0);
461 
462 	if ((lml->lm_flags & (LML_FLG_BASELM | LML_FLG_RTLDLM)) == 0)
463 		remove_lml(lml);
464 
465 	return (error);
466 }
467 
468 /*
469  * Internal dlclose activity.  Called from user level or directly for internal
470  * error cleanup.
471  */
472 int
473 dlclose_intn(Grp_hdl *ghp, Rt_map *clmp)
474 {
475 	Rt_map	*nlmp = 0;
476 	Lm_list	*olml = 0;
477 	int	error;
478 
479 	/*
480 	 * Although we're deleting object(s) it's quite possible that additional
481 	 * objects get loaded from running the .fini section(s) of the objects
482 	 * being deleted.  These objects will have been added to the same
483 	 * link-map list as those objects being deleted.  Remember this list
484 	 * for later investigation.
485 	 */
486 	olml = ghp->gh_ownlml;
487 
488 	error = dlclose_core(ghp, clmp, olml);
489 
490 	/*
491 	 * Determine whether the original link-map list still exists.  In the
492 	 * case of a dlclose of an alternative (dlmopen) link-map the whole
493 	 * list may have been removed.
494 	 */
495 	if (olml) {
496 		Listnode	*lnp;
497 		Lm_list		*lml;
498 
499 		for (LIST_TRAVERSE(&dynlm_list, lnp, lml)) {
500 			if (olml == lml) {
501 				nlmp = olml->lm_head;
502 				break;
503 			}
504 		}
505 	}
506 	load_completion(nlmp);
507 	return (error);
508 }
509 
510 /*
511  * Argument checking for dlclose.  Only called via external entry.
512  */
513 static int
514 dlclose_check(void *handle, Rt_map *clmp)
515 {
516 	Grp_hdl	*ghp = (Grp_hdl *)handle;
517 
518 	if (hdl_validate(ghp) == 0) {
519 		eprintf(LIST(clmp), ERR_FATAL, MSG_INTL(MSG_ARG_INVHNDL));
520 		return (1);
521 	}
522 	return (dlclose_intn(ghp, clmp));
523 }
524 
525 #pragma weak dlclose = _dlclose
526 
527 /*
528  * External entry for dlclose(3dl).  Returns 0 for success, non-zero otherwise.
529  */
530 int
531 _dlclose(void *handle)
532 {
533 	int		error, entry;
534 	Rt_map		*clmp;
535 
536 	entry = enter();
537 
538 	clmp = _caller(caller(), CL_EXECDEF);
539 
540 	error = dlclose_check(handle, clmp);
541 
542 	if (entry)
543 		leave(LIST(clmp));
544 	return (error);
545 }
546 
547 static uint_t	lmid = 0;
548 
549 /*
550  * The addition of new link-map lists is assumed to be in small quantities.
551  * Here, we assign a unique link-map id for diagnostic use.  Simply update the
552  * running link-map count until we max out.
553  */
554 int
555 newlmid(Lm_list *lml)
556 {
557 	char	buffer[MSG_LMID_ALT_SIZE + 12];
558 
559 	if (lmid == UINT_MAX) {
560 		lml->lm_lmid = UINT_MAX;
561 		(void) strncpy(buffer, MSG_ORIG(MSG_LMID_MAXED),
562 		    MSG_LMID_ALT_SIZE + 12);
563 	} else {
564 		lml->lm_lmid = lmid++;
565 		(void) snprintf(buffer, MSG_LMID_ALT_SIZE + 12,
566 		    MSG_ORIG(MSG_LMID_FMT), MSG_ORIG(MSG_LMID_ALT),
567 		    lml->lm_lmid);
568 	}
569 	if ((lml->lm_lmidstr = strdup(buffer)) == 0)
570 		return (0);
571 
572 	return (1);
573 }
574 
575 /*
576  * Core dlopen activity.
577  */
578 static Grp_hdl *
579 dlmopen_core(Lm_list *lml, const char *path, int mode, Rt_map *clmp,
580     uint_t flags, uint_t orig, int *in_nfavl)
581 {
582 	Rt_map	*nlmp;
583 	Grp_hdl	*ghp;
584 	Pnode	*pnp;
585 	Aliste	olmco, nlmco;
586 	Lm_cntl	*lmc;
587 
588 	DBG_CALL(Dbg_file_dlopen(clmp,
589 	    (path ? path : MSG_ORIG(MSG_STR_ZERO)), in_nfavl, mode));
590 
591 	/*
592 	 * If the path specified is null then we're operating on global
593 	 * objects.  Associate a dummy handle with the link-map list.
594 	 */
595 	if (path == 0) {
596 		Grp_hdl *ghp;
597 		uint_t	hflags = GPH_ZERO, cdflags = GPD_PARENT;
598 		int	promote = 0;
599 
600 		/*
601 		 * Establish any flags for the handle (Grp_hdl).
602 		 *
603 		 *  .	This is a dummy handle (0) that provides for a dynamic
604 		 *	search of all global objects within the process.
605 		 *
606 		 *  .   Use of the RTLD_FIRST flag indicates that only the first
607 		 *	dependency on the handle (the new object) can be used
608 		 *	to satisfy dlsym() requests.
609 		 */
610 		if (mode & RTLD_FIRST)
611 			hflags |= GPH_FIRST;
612 
613 		/*
614 		 * Establish the flags for this callers dependency descriptor
615 		 * (Grp_desc).
616 		 *
617 		 *  .	The explicit creation of a handle creates a descriptor
618 		 *	for the new object and the parent (caller),
619 		 *
620 		 *  .	Use of the RTLD_PARENT flag indicates that the parent
621 		 *	can be relocated against.
622 		 */
623 		if (mode & RTLD_PARENT)
624 			cdflags |= GPD_RELOC;
625 
626 		if ((ghp = hdl_create(lml, 0, clmp, hflags,
627 		    (GPD_DLSYM | GPD_RELOC | GPD_ADDEPS), cdflags)) == 0)
628 			return (0);
629 
630 		/*
631 		 * Traverse the main link-map control list, updating the mode
632 		 * of any objects as necessary.  Call the relocation engine if
633 		 * this mode promotes the existing state of any relocations.
634 		 * crle()'s first pass loads all objects necessary for building
635 		 * a configuration file, however none of them are relocated.
636 		 * crle()'s second pass relocates objects in preparation for
637 		 * dldump()'ing using dlopen(0, RTLD_NOW).
638 		 */
639 		if ((mode & (RTLD_NOW | RTLD_CONFGEN)) == RTLD_CONFGEN)
640 			return (ghp);
641 
642 		for (nlmp = lml->lm_head; nlmp; nlmp = (Rt_map *)NEXT(nlmp)) {
643 			if (((MODE(nlmp) & RTLD_GLOBAL) == 0) ||
644 			    (FLAGS(nlmp) & FLG_RT_DELETE))
645 				continue;
646 
647 			if (update_mode(nlmp, MODE(nlmp), mode))
648 				promote = 1;
649 		}
650 		if (promote)
651 			(void) relocate_lmc(lml, ALIST_OFF_DATA, clmp,
652 			    lml->lm_head, in_nfavl);
653 
654 		return (ghp);
655 	}
656 
657 	/*
658 	 * Fix the pathname.  If this object expands to multiple paths (ie.
659 	 * $ISALIST or $HWCAP have been used), then make sure the user has also
660 	 * furnished the RTLD_FIRST flag.  As yet, we don't support opening
661 	 * more than one object at a time, so enforcing the RTLD_FIRST flag
662 	 * provides flexibility should we be able to support dlopening more
663 	 * than one object in the future.
664 	 */
665 	if ((pnp = LM_FIX_NAME(clmp)(path, clmp, orig)) == 0)
666 		return (0);
667 
668 	if (((pnp->p_orig & (PN_TKN_ISALIST | PN_TKN_HWCAP)) || pnp->p_next) &&
669 	    ((mode & RTLD_FIRST) == 0)) {
670 		remove_pnode(pnp);
671 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLMODE_5));
672 		return (0);
673 	}
674 
675 	/*
676 	 * Create a new link-map control list for this request, and load the
677 	 * associated object.
678 	 */
679 	if ((lmc = alist_append(&lml->lm_lists, 0, sizeof (Lm_cntl),
680 	    AL_CNT_LMLISTS)) == 0) {
681 		remove_pnode(pnp);
682 		return (0);
683 	}
684 	olmco = nlmco = (Aliste)((char *)lmc - (char *)lml->lm_lists);
685 
686 	nlmp = load_one(lml, nlmco, pnp, clmp, mode,
687 	    (flags | FLG_RT_HANDLE), &ghp, in_nfavl);
688 
689 	/*
690 	 * Remove any expanded pathname infrastructure, and if the dependency
691 	 * couldn't be loaded, cleanup.
692 	 */
693 	remove_pnode(pnp);
694 	if (nlmp == 0) {
695 		remove_cntl(lml, olmco);
696 		return (0);
697 	}
698 
699 	/*
700 	 * If loading an auditor was requested, and the auditor already existed,
701 	 * then the link-map returned will be to the original auditor.  The new
702 	 * link-map list that was initially created, and the associated link-map
703 	 * control list are no longer needed.  As the auditor is already loaded,
704 	 * we're probably done, but fall through in case additional relocations
705 	 * would be triggered by the mode of the caller.
706 	 */
707 	if ((flags & FLG_RT_AUDIT) && (LIST(nlmp) != lml)) {
708 		remove_cntl(lml, olmco);
709 		lml = LIST(nlmp);
710 		olmco = 0;
711 		nlmco = ALIST_OFF_DATA;
712 	}
713 
714 	/*
715 	 * Finish processing the objects associated with this request.
716 	 */
717 	if ((analyze_lmc(lml, nlmco, nlmp, in_nfavl) == 0) ||
718 	    (relocate_lmc(lml, nlmco, clmp, nlmp, in_nfavl) == 0)) {
719 		ghp = 0;
720 		nlmp = 0;
721 	}
722 
723 	/*
724 	 * If this lazyload has failed, and we've created a new link-map
725 	 * control list to which this request has added objects, then remove
726 	 * all the objects that have been associated to this request.
727 	 */
728 	if ((nlmp == 0) && olmco && lmc->lc_head)
729 		remove_lmc(lml, clmp, lmc, olmco, path);
730 
731 	/*
732 	 * Finally, remove any link-map control list that was created.
733 	 */
734 	if (olmco)
735 		remove_cntl(lml, olmco);
736 
737 	return (ghp);
738 }
739 
740 /*
741  * dlopen() and dlsym() operations are the means by which a process can
742  * test for the existence of required dependencies.  If the necessary
743  * dependencies don't exist, then associated functionality can't be used.
744  * However, the lack of dependencies can be fixed, and the dlopen() and
745  * dlsym() requests can be repeated.  As we use a "not-found" AVL tree to
746  * cache any failed full path loads, secondary dlopen() and dlsym() requests
747  * will fail, even if the dependencies have been installed.
748  *
749  * dlopen() and dlsym() retry any failures by removing the "not-found" AVL
750  * tree.  Should any dependencies be found, their names are added to the
751  * FullPath AVL tree.  This routine removes any new "not-found" AVL tree,
752  * so that the dlopen() or dlsym() can replace the original "not-found" tree.
753  */
754 inline static void
755 nfavl_remove(avl_tree_t *avlt)
756 {
757 	PathNode	*pnp;
758 	void		*cookie = NULL;
759 
760 	if (avlt) {
761 		while ((pnp = avl_destroy_nodes(avlt, &cookie)) != NULL) {
762 			free((void *)pnp->pn_name);
763 			free(pnp);
764 		}
765 		avl_destroy(avlt);
766 		free(avlt);
767 	}
768 }
769 
770 /*
771  * Internal dlopen() activity.  Called from user level or directly for internal
772  * opens that require a handle.
773  */
774 Grp_hdl *
775 dlmopen_intn(Lm_list *lml, const char *path, int mode, Rt_map *clmp,
776     uint_t flags, uint_t orig)
777 {
778 	Rt_map	*dlmp = 0;
779 	Grp_hdl	*ghp;
780 	int	in_nfavl = 0;
781 
782 	/*
783 	 * Check for magic link-map list values:
784 	 *
785 	 *  LM_ID_BASE:		Operate on the PRIMARY (executables) link map
786 	 *  LM_ID_LDSO:		Operation on ld.so.1's link map
787 	 *  LM_ID_NEWLM: 	Create a new link-map.
788 	 */
789 	if (lml == (Lm_list *)LM_ID_NEWLM) {
790 		if ((lml = calloc(sizeof (Lm_list), 1)) == 0)
791 			return (0);
792 
793 		/*
794 		 * Establish the new link-map flags from the callers and those
795 		 * explicitly provided.
796 		 */
797 		lml->lm_tflags = LIST(clmp)->lm_tflags;
798 		if (flags & FLG_RT_AUDIT) {
799 			/*
800 			 * Unset any auditing flags - an auditor shouldn't be
801 			 * audited.  Insure all audit dependencies are loaded.
802 			 */
803 			lml->lm_tflags &= ~LML_TFLG_AUD_MASK;
804 			lml->lm_tflags |=
805 			    (LML_TFLG_NOLAZYLD | LML_TFLG_LOADFLTR);
806 			lml->lm_flags |= LML_FLG_NOAUDIT;
807 		}
808 
809 		if (list_append(&dynlm_list, lml) == 0) {
810 			free(lml);
811 			return (0);
812 		}
813 		if (newlmid(lml) == 0) {
814 			list_delete(&dynlm_list, lml);
815 			free(lml);
816 			return (0);
817 		}
818 	} else if ((uintptr_t)lml < LM_ID_NUM) {
819 		if ((uintptr_t)lml == LM_ID_BASE)
820 			lml = &lml_main;
821 		else if ((uintptr_t)lml == LM_ID_LDSO)
822 			lml = &lml_rtld;
823 	}
824 
825 	/*
826 	 * Open the required object on the associated link-map list.
827 	 */
828 	ghp = dlmopen_core(lml, path, mode, clmp, flags, orig, &in_nfavl);
829 
830 	/*
831 	 * If the object could not be found it is possible that the "not-found"
832 	 * AVL tree had indicated that the file does not exist.  In case the
833 	 * file system has changes since this "not-found" recording was made,
834 	 * retry the dlopen() with a clean "not-found" AVL tree.
835 	 */
836 	if ((ghp == 0) && in_nfavl) {
837 		avl_tree_t	*oavlt = nfavl;
838 
839 		nfavl = NULL;
840 		ghp = dlmopen_core(lml, path, mode, clmp, flags, orig, NULL);
841 
842 		/*
843 		 * If the file is found, then its full path name will have been
844 		 * registered in the FullPath AVL tree.  Remove any new
845 		 * "not-found" AVL information, and restore the former AVL tree.
846 		 */
847 		nfavl_remove(nfavl);
848 		nfavl = oavlt;
849 	}
850 
851 	/*
852 	 * Establish the new link-map from which .init processing will begin.
853 	 * Ignore .init firing when constructing a configuration file (crle(1)).
854 	 */
855 	if (ghp && ((mode & RTLD_CONFGEN) == 0))
856 		dlmp = ghp->gh_ownlmp;
857 
858 	/*
859 	 * If loading an auditor was requested, and the auditor already existed,
860 	 * then the link-map returned will be to the original auditor.  Remove
861 	 * the link-map control list that was created for this request.
862 	 */
863 	if (dlmp && (flags & FLG_RT_AUDIT) && (LIST(dlmp) != lml)) {
864 		remove_lml(lml);
865 		lml = LIST(dlmp);
866 	}
867 
868 	/*
869 	 * If this load failed, remove any alternative link-map list.
870 	 */
871 	if ((ghp == 0) &&
872 	    ((lml->lm_flags & (LML_FLG_BASELM | LML_FLG_RTLDLM)) == 0)) {
873 		remove_lml(lml);
874 		lml = 0;
875 	}
876 
877 	/*
878 	 * Finish this load request.  If objects were loaded, .init processing
879 	 * is computed.  Finally, the debuggers are informed of the link-map
880 	 * lists being stable.
881 	 */
882 	load_completion(dlmp);
883 
884 	return (ghp);
885 }
886 
887 /*
888  * Argument checking for dlopen.  Only called via external entry.
889  */
890 static Grp_hdl *
891 dlmopen_check(Lm_list *lml, const char *path, int mode, Rt_map *clmp)
892 {
893 	/*
894 	 * Verify that a valid pathname has been supplied.
895 	 */
896 	if (path && (*path == '\0')) {
897 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLPATH));
898 		return (0);
899 	}
900 
901 	/*
902 	 * Historically we've always verified the mode is either RTLD_NOW or
903 	 * RTLD_LAZY.  RTLD_NOLOAD is valid by itself.  Use of LM_ID_NEWLM
904 	 * requires a specific pathname, and use of RTLD_PARENT is meaningless.
905 	 */
906 	if ((mode & (RTLD_NOW | RTLD_LAZY | RTLD_NOLOAD)) == 0) {
907 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLMODE_1));
908 		return (0);
909 	}
910 	if ((mode & (RTLD_NOW | RTLD_LAZY)) == (RTLD_NOW | RTLD_LAZY)) {
911 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLMODE_2));
912 		return (0);
913 	}
914 	if ((lml == (Lm_list *)LM_ID_NEWLM) && (path == 0)) {
915 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLMODE_3));
916 		return (0);
917 	}
918 	if ((lml == (Lm_list *)LM_ID_NEWLM) && (mode & RTLD_PARENT)) {
919 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLMODE_4));
920 		return (0);
921 	}
922 	if (((mode & (RTLD_GROUP | RTLD_WORLD)) == 0) &&
923 	    ((mode & RTLD_NOLOAD) == 0))
924 		mode |= (RTLD_GROUP | RTLD_WORLD);
925 	if ((mode & RTLD_NOW) && (rtld_flags2 & RT_FL2_BINDLAZY)) {
926 		mode &= ~RTLD_NOW;
927 		mode |= RTLD_LAZY;
928 	}
929 
930 	return (dlmopen_intn(lml, path, mode, clmp, 0, 0));
931 }
932 
933 #pragma weak dlopen = _dlopen
934 
935 /*
936  * External entry for dlopen(3dl).  On success, returns a pointer (handle) to
937  * the structure containing information about the newly added object, ie. can
938  * be used by dlsym(). On failure, returns a null pointer.
939  */
940 void *
941 _dlopen(const char *path, int mode)
942 {
943 	int	entry;
944 	Rt_map	*clmp;
945 	Grp_hdl	*ghp;
946 	Lm_list	*lml;
947 
948 	entry = enter();
949 
950 	clmp = _caller(caller(), CL_EXECDEF);
951 	lml = LIST(clmp);
952 
953 	ghp = dlmopen_check(lml, path, mode, clmp);
954 
955 	if (entry)
956 		leave(lml);
957 	return ((void *)ghp);
958 }
959 
960 /*
961  * External entry for dlmopen(3dl).
962  */
963 #pragma weak dlmopen = _dlmopen
964 
965 void *
966 _dlmopen(Lmid_t lmid, const char *path, int mode)
967 {
968 	int	entry;
969 	Rt_map	*clmp;
970 	Grp_hdl	*ghp;
971 
972 	entry = enter();
973 
974 	clmp = _caller(caller(), CL_EXECDEF);
975 
976 	ghp = dlmopen_check((Lm_list *)lmid, path, mode, clmp);
977 
978 	if (entry)
979 		leave(LIST(clmp));
980 	return ((void *)ghp);
981 }
982 
983 /*
984  * Handle processing for dlsym.
985  */
986 Sym *
987 dlsym_handle(Grp_hdl *ghp, Slookup *slp, Rt_map **_lmp, uint_t *binfo,
988     int *in_nfavl)
989 {
990 	Rt_map		*nlmp, * lmp = ghp->gh_ownlmp;
991 	Rt_map		*clmp = slp->sl_cmap;
992 	const char	*name = slp->sl_name;
993 	Sym		*sym = 0;
994 	Slookup		sl = *slp;
995 
996 	sl.sl_flags = (LKUP_FIRST | LKUP_SPEC);
997 
998 	/*
999 	 * Continue processing a dlsym request.  Lookup the required symbol in
1000 	 * each link-map specified by the handle.
1001 	 *
1002 	 * To leverage off of lazy loading, dlsym() requests can result in two
1003 	 * passes.  The first descends the link-maps of any objects already in
1004 	 * the address space.  If the symbol isn't located, and lazy
1005 	 * dependencies still exist, then a second pass is made to load these
1006 	 * dependencies if applicable.  This model means that in the case where
1007 	 * a symbols exists in more than one object, the one located may not be
1008 	 * constant - this is the standard issue with lazy loading. In addition,
1009 	 * attempting to locate a symbol that doesn't exist will result in the
1010 	 * loading of all lazy dependencies on the given handle, which can
1011 	 * defeat some of the advantages of lazy loading (look out JVM).
1012 	 */
1013 	if (ghp->gh_flags & GPH_ZERO) {
1014 		Lm_list	*lml;
1015 
1016 		/*
1017 		 * If this symbol lookup is triggered from a dlopen(0) handle,
1018 		 * traverse the present link-map list looking for promiscuous
1019 		 * entries.
1020 		 */
1021 		for (nlmp = lmp; nlmp; nlmp = (Rt_map *)NEXT(nlmp)) {
1022 
1023 			/*
1024 			 * If this handle indicates we're only to look in the
1025 			 * first object check whether we're done.
1026 			 */
1027 			if ((nlmp != lmp) && (ghp->gh_flags & GPH_FIRST))
1028 				return ((Sym *)0);
1029 
1030 			if (!(MODE(nlmp) & RTLD_GLOBAL))
1031 				continue;
1032 			if ((FLAGS(nlmp) & FLG_RT_DELETE) &&
1033 			    ((FLAGS(clmp) & FLG_RT_DELETE) == 0))
1034 				continue;
1035 
1036 			sl.sl_imap = nlmp;
1037 			if (sym = LM_LOOKUP_SYM(clmp)(&sl, _lmp, binfo,
1038 			    in_nfavl))
1039 				return (sym);
1040 		}
1041 
1042 		/*
1043 		 * If we're unable to locate the symbol and this link-map still
1044 		 * has pending lazy dependencies, start loading them in an
1045 		 * attempt to exhaust the search.  Note that as we're already
1046 		 * traversing a dynamic linked list of link-maps there's no
1047 		 * need for elf_lazy_find_sym() to descend the link-maps itself.
1048 		 */
1049 		lml = LIST(lmp);
1050 		if ((lml->lm_lazy) &&
1051 		    ((lml->lm_flags & LML_FLG_NOPENDGLBLAZY) == 0)) {
1052 			int	lazy = 0;
1053 
1054 			DBG_CALL(Dbg_syms_lazy_rescan(lml, name));
1055 
1056 			sl.sl_flags |= LKUP_NODESCENT;
1057 
1058 			for (nlmp = lmp; nlmp; nlmp = (Rt_map *)NEXT(nlmp)) {
1059 
1060 				if (!(MODE(nlmp) & RTLD_GLOBAL) || !LAZY(nlmp))
1061 					continue;
1062 				if ((FLAGS(nlmp) & FLG_RT_DELETE) &&
1063 				    ((FLAGS(clmp) & FLG_RT_DELETE) == 0))
1064 					continue;
1065 
1066 				lazy = 1;
1067 				sl.sl_imap = nlmp;
1068 				if (sym = elf_lazy_find_sym(&sl, _lmp, binfo,
1069 				    in_nfavl))
1070 					return (sym);
1071 			}
1072 
1073 			/*
1074 			 * If no global, lazy loadable dependencies are found,
1075 			 * then none exist for this link-map list.  Pending lazy
1076 			 * loadable objects may still exist for non-local
1077 			 * objects that are associated with this link-map list,
1078 			 * which is why we entered this fallback.  Tag this
1079 			 * link-map list to prevent further searching for lazy
1080 			 * dependencies.
1081 			 */
1082 			if (lazy == 0)
1083 				lml->lm_flags |= LML_FLG_NOPENDGLBLAZY;
1084 		}
1085 	} else {
1086 		/*
1087 		 * Traverse the dlopen() handle for the presently loaded
1088 		 * link-maps.
1089 		 */
1090 		Grp_desc	*gdp;
1091 		Aliste		idx;
1092 
1093 		for (ALIST_TRAVERSE(ghp->gh_depends, idx, gdp)) {
1094 			if ((gdp->gd_flags & GPD_DLSYM) == 0)
1095 				continue;
1096 
1097 			sl.sl_imap = gdp->gd_depend;
1098 			if (sym = LM_LOOKUP_SYM(clmp)(&sl, _lmp, binfo,
1099 			    in_nfavl))
1100 				return (sym);
1101 
1102 			if (ghp->gh_flags & GPH_FIRST)
1103 				return ((Sym *)0);
1104 		}
1105 
1106 		/*
1107 		 * If we're unable to locate the symbol and this link-map still
1108 		 * has pending lazy dependencies, start loading them in an
1109 		 * attempt to exhaust the search.
1110 		 */
1111 		if ((LIST(lmp)->lm_lazy) &&
1112 		    ((ghp->gh_flags & GPH_NOPENDLAZY) == 0)) {
1113 			int	lazy = 0;
1114 
1115 			DBG_CALL(Dbg_syms_lazy_rescan(LIST(lmp), name));
1116 
1117 			for (ALIST_TRAVERSE(ghp->gh_depends, idx, gdp)) {
1118 				nlmp = gdp->gd_depend;
1119 
1120 				if (((gdp->gd_flags & GPD_DLSYM) == 0) ||
1121 				    (LAZY(nlmp) == 0))
1122 					continue;
1123 
1124 				lazy = 1;
1125 				sl.sl_imap = nlmp;
1126 				if (sym = elf_lazy_find_sym(&sl, _lmp,
1127 				    binfo, in_nfavl))
1128 					return (sym);
1129 			}
1130 
1131 			/*
1132 			 * If no lazy loadable dependencies are found, then
1133 			 * none exist for this handle.  Pending lazy loadable
1134 			 * objects may still exist for the associated link-map
1135 			 * list, which is why we entered this fallback.  Tag
1136 			 * this handle to prevent further searching for lazy
1137 			 * dependencies.
1138 			 */
1139 			if (lazy == 0)
1140 				ghp->gh_flags |= GPH_NOPENDLAZY;
1141 		}
1142 	}
1143 	return ((Sym *)0);
1144 }
1145 
1146 /*
1147  * Core dlsym activity.  Selects symbol lookup method from handle.
1148  */
1149 void *
1150 dlsym_core(void *handle, const char *name, Rt_map *clmp, Rt_map **dlmp,
1151     int *in_nfavl)
1152 {
1153 	Sym		*sym = NULL;
1154 	Syminfo		*sip;
1155 	Slookup		sl;
1156 	uint_t		binfo;
1157 
1158 	/*
1159 	 * Initialize the symbol lookup data structure.
1160 	 *
1161 	 * Standard relocations are evaluated using the symbol index of the
1162 	 * associated relocation symbol.  This index provides for loading
1163 	 * any lazy dependency and establishing a direct binding if necessary.
1164 	 * If a dlsym() operation originates from an object that contains a
1165 	 * symbol table entry for the same name, then we need to establish the
1166 	 * symbol index so that any dependency requirements can be triggered.
1167 	 *
1168 	 * Therefore, the first symbol lookup that is carried out is for the
1169 	 * symbol name within the calling object.  If this symbol exists, the
1170 	 * symbols index is computed, added to the Slookup data, and thus used
1171 	 * to seed the real symbol lookup.
1172 	 */
1173 	SLOOKUP_INIT(sl, name, clmp, clmp, ld_entry_cnt, elf_hash(name),
1174 	    0, 0, 0, LKUP_SYMNDX);
1175 
1176 	if ((FCT(clmp) == &elf_fct) &&
1177 	    ((sym = SYMINTP(clmp)(&sl, 0, 0, NULL)) != NULL)) {
1178 		sl.sl_rsymndx = (((ulong_t)sym -
1179 		    (ulong_t)SYMTAB(clmp)) / SYMENT(clmp));
1180 		sl.sl_rsym = sym;
1181 	}
1182 
1183 	if (sym && (ELF_ST_VISIBILITY(sym->st_other) == STV_SINGLETON)) {
1184 		Rt_map	*hlmp = LIST(clmp)->lm_head;
1185 
1186 		/*
1187 		 * If a symbol reference is known, and that reference indicates
1188 		 * that the symbol is a singleton, then the search for the
1189 		 * symbol must follow the default search path.
1190 		 */
1191 		DBG_CALL(Dbg_syms_dlsym(clmp, name, in_nfavl, 0,
1192 		    DBG_DLSYM_SINGLETON));
1193 
1194 		sl.sl_imap = hlmp;
1195 		sl.sl_flags = LKUP_SPEC;
1196 		if (handle == RTLD_PROBE)
1197 			sl.sl_flags |= LKUP_NOFALLBACK;
1198 		sym = LM_LOOKUP_SYM(clmp)(&sl, dlmp, &binfo, in_nfavl);
1199 
1200 	} else if (handle == RTLD_NEXT) {
1201 		Rt_map	*nlmp;
1202 
1203 		/*
1204 		 * If this handle is RTLD_NEXT determine whether a lazy load
1205 		 * from the caller might provide the next object.  This mimics
1206 		 * the lazy loading initialization normally carried out by
1207 		 * lookup_sym(), however here, we must do this up-front, as
1208 		 * lookup_sym() will be used to inspect the next object.
1209 		 */
1210 		if ((sl.sl_rsymndx) && ((sip = SYMINFO(clmp)) != 0)) {
1211 			/* LINTED */
1212 			sip = (Syminfo *)((char *)sip +
1213 			    (sl.sl_rsymndx * SYMINENT(clmp)));
1214 
1215 			if ((sip->si_flags & SYMINFO_FLG_DIRECT) &&
1216 			    (sip->si_boundto < SYMINFO_BT_LOWRESERVE))
1217 				(void) elf_lazy_load(clmp, &sl,
1218 				    sip->si_boundto, name, in_nfavl);
1219 
1220 			/*
1221 			 * Clear the symbol index, so as not to confuse
1222 			 * lookup_sym() of the next object.
1223 			 */
1224 			sl.sl_rsymndx = 0;
1225 			sl.sl_rsym = 0;
1226 		}
1227 
1228 		/*
1229 		 * If the handle is RTLD_NEXT start searching in the next link
1230 		 * map from the callers.  Determine permissions from the
1231 		 * present link map.  Indicate to lookup_sym() that we're on an
1232 		 * RTLD_NEXT request so that it will use the callers link map to
1233 		 * start any possible lazy dependency loading.
1234 		 */
1235 		sl.sl_imap = nlmp = (Rt_map *)NEXT(clmp);
1236 
1237 		DBG_CALL(Dbg_syms_dlsym(clmp, name, in_nfavl,
1238 		    (nlmp ? NAME(nlmp) : MSG_INTL(MSG_STR_NULL)),
1239 		    DBG_DLSYM_NEXT));
1240 
1241 		if (nlmp == 0)
1242 			return (0);
1243 
1244 		sl.sl_flags = LKUP_NEXT;
1245 		sym = LM_LOOKUP_SYM(clmp)(&sl, dlmp, &binfo, in_nfavl);
1246 
1247 	} else if (handle == RTLD_SELF) {
1248 		/*
1249 		 * If the handle is RTLD_SELF start searching from the caller.
1250 		 */
1251 		DBG_CALL(Dbg_syms_dlsym(clmp, name, in_nfavl, NAME(clmp),
1252 		    DBG_DLSYM_SELF));
1253 
1254 		sl.sl_imap = clmp;
1255 		sl.sl_flags = (LKUP_SPEC | LKUP_SELF);
1256 		sym = LM_LOOKUP_SYM(clmp)(&sl, dlmp, &binfo, in_nfavl);
1257 
1258 	} else if (handle == RTLD_DEFAULT) {
1259 		Rt_map	*hlmp = LIST(clmp)->lm_head;
1260 
1261 		/*
1262 		 * If the handle is RTLD_DEFAULT mimic the standard symbol
1263 		 * lookup as would be triggered by a relocation.
1264 		 */
1265 		DBG_CALL(Dbg_syms_dlsym(clmp, name, in_nfavl, 0,
1266 		    DBG_DLSYM_DEFAULT));
1267 
1268 		sl.sl_imap = hlmp;
1269 		sl.sl_flags = LKUP_SPEC;
1270 		sym = LM_LOOKUP_SYM(clmp)(&sl, dlmp, &binfo, in_nfavl);
1271 
1272 	} else if (handle == RTLD_PROBE) {
1273 		Rt_map	*hlmp = LIST(clmp)->lm_head;
1274 
1275 		/*
1276 		 * If the handle is RTLD_PROBE, mimic the standard symbol
1277 		 * lookup as would be triggered by a relocation, however do
1278 		 * not fall back to a lazy loading rescan if the symbol can't be
1279 		 * found within the currently loaded objects.  Note, a lazy
1280 		 * loaded dependency required by the caller might still get
1281 		 * loaded to satisfy this request, but no exhaustive lazy load
1282 		 * rescan is carried out.
1283 		 */
1284 		DBG_CALL(Dbg_syms_dlsym(clmp, name, in_nfavl, 0,
1285 		    DBG_DLSYM_PROBE));
1286 
1287 		sl.sl_imap = hlmp;
1288 		sl.sl_flags = (LKUP_SPEC | LKUP_NOFALLBACK);
1289 		sym = LM_LOOKUP_SYM(clmp)(&sl, dlmp, &binfo, in_nfavl);
1290 
1291 	} else {
1292 		Grp_hdl *ghp = (Grp_hdl *)handle;
1293 
1294 		/*
1295 		 * Look in the shared object specified by the handle and in all
1296 		 * of its dependencies.
1297 		 */
1298 		DBG_CALL(Dbg_syms_dlsym(clmp, name, in_nfavl,
1299 		    NAME(ghp->gh_ownlmp), DBG_DLSYM_DEF));
1300 
1301 		sym = LM_DLSYM(clmp)(ghp, &sl, dlmp, &binfo, in_nfavl);
1302 	}
1303 
1304 	if (sym) {
1305 		Lm_list	*lml = LIST(clmp);
1306 		Addr	addr = sym->st_value;
1307 
1308 		if (!(FLAGS(*dlmp) & FLG_RT_FIXED))
1309 			addr += ADDR(*dlmp);
1310 
1311 		/*
1312 		 * Indicate that the defining object is now used.
1313 		 */
1314 		if (*dlmp != clmp)
1315 			FLAGS1(*dlmp) |= FL1_RT_USED;
1316 
1317 		DBG_CALL(Dbg_bind_global(clmp, 0, 0, (Xword)-1, PLT_T_NONE,
1318 		    *dlmp, addr, sym->st_value, name, binfo));
1319 
1320 		if ((lml->lm_tflags | FLAGS1(clmp)) & LML_TFLG_AUD_SYMBIND) {
1321 			uint_t	sb_flags = LA_SYMB_DLSYM;
1322 			/* LINTED */
1323 			uint_t	symndx = (uint_t)(((Xword)sym -
1324 			    (Xword)SYMTAB(*dlmp)) / SYMENT(*dlmp));
1325 			addr = audit_symbind(clmp, *dlmp, sym, symndx, addr,
1326 			    &sb_flags);
1327 		}
1328 		return ((void *)addr);
1329 	} else
1330 		return (0);
1331 }
1332 
1333 /*
1334  * Internal dlsym activity.  Called from user level or directly for internal
1335  * symbol lookup.
1336  */
1337 void *
1338 dlsym_intn(void *handle, const char *name, Rt_map *clmp, Rt_map **dlmp)
1339 {
1340 	Rt_map		*llmp = 0;
1341 	void		*error;
1342 	Aliste		idx;
1343 	Grp_desc	*gdp;
1344 	int		in_nfavl = 0;
1345 
1346 	/*
1347 	 * While looking for symbols it's quite possible that additional objects
1348 	 * get loaded from lazy loading.  These objects will have been added to
1349 	 * the same link-map list as those objects on the handle.  Remember this
1350 	 * list for later investigation.
1351 	 */
1352 	if ((handle == RTLD_NEXT) || (handle == RTLD_DEFAULT) ||
1353 	    (handle == RTLD_SELF) || (handle == RTLD_PROBE))
1354 		llmp = LIST(clmp)->lm_tail;
1355 	else {
1356 		Grp_hdl	*ghp = (Grp_hdl *)handle;
1357 
1358 		if (ghp->gh_ownlmp)
1359 			llmp = LIST(ghp->gh_ownlmp)->lm_tail;
1360 		else {
1361 			for (ALIST_TRAVERSE(ghp->gh_depends, idx, gdp)) {
1362 				if ((llmp = LIST(gdp->gd_depend)->lm_tail) != 0)
1363 					break;
1364 			}
1365 		}
1366 	}
1367 
1368 	error = dlsym_core(handle, name, clmp, dlmp, &in_nfavl);
1369 
1370 	/*
1371 	 * If the symbol could not be found it is possible that the "not-found"
1372 	 * AVL tree had indicated that a required file does not exist.  In case
1373 	 * the file system has changed since this "not-found" recording was
1374 	 * made, retry the dlsym() with a clean "not-found" AVL tree.
1375 	 */
1376 	if ((error == 0) && in_nfavl) {
1377 		avl_tree_t	*oavlt = nfavl;
1378 
1379 		nfavl = NULL;
1380 		error = dlsym_core(handle, name, clmp, dlmp, NULL);
1381 
1382 		/*
1383 		 * If the symbol is found, then any file that was loaded will
1384 		 * have had its full path name registered in the FullPath AVL
1385 		 * tree.  Remove any new "not-found" AVL information, and
1386 		 * restore the former AVL tree.
1387 		 */
1388 		nfavl_remove(nfavl);
1389 		nfavl = oavlt;
1390 	}
1391 
1392 	if (error == 0) {
1393 		/*
1394 		 * Cache the error message, as Java tends to fall through this
1395 		 * code many times.
1396 		 */
1397 		if (nosym_str == 0)
1398 			nosym_str = MSG_INTL(MSG_GEN_NOSYM);
1399 		eprintf(LIST(clmp), ERR_FATAL, nosym_str, name);
1400 	}
1401 
1402 	load_completion(llmp);
1403 	return (error);
1404 }
1405 
1406 /*
1407  * Argument checking for dlsym.  Only called via external entry.
1408  */
1409 static void *
1410 dlsym_check(void *handle, const char *name, Rt_map *clmp, Rt_map **dlmp)
1411 {
1412 	/*
1413 	 * Verify the arguments.
1414 	 */
1415 	if (name == 0) {
1416 		eprintf(LIST(clmp), ERR_FATAL, MSG_INTL(MSG_ARG_ILLSYM));
1417 		return (0);
1418 	}
1419 	if ((handle != RTLD_NEXT) && (handle != RTLD_DEFAULT) &&
1420 	    (handle != RTLD_SELF) && (handle != RTLD_PROBE) &&
1421 	    (hdl_validate((Grp_hdl *)handle) == 0)) {
1422 		eprintf(LIST(clmp), ERR_FATAL, MSG_INTL(MSG_ARG_INVHNDL));
1423 		return (0);
1424 	}
1425 	return (dlsym_intn(handle, name, clmp, dlmp));
1426 }
1427 
1428 
1429 #pragma weak dlsym = _dlsym
1430 
1431 /*
1432  * External entry for dlsym().  On success, returns the address of the specified
1433  * symbol.  On error returns a null.
1434  */
1435 void *
1436 _dlsym(void *handle, const char *name)
1437 {
1438 	int	entry;
1439 	Rt_map	*clmp, *dlmp = 0;
1440 	void	*addr;
1441 
1442 	entry = enter();
1443 
1444 	clmp = _caller(caller(), CL_EXECDEF);
1445 
1446 	addr = dlsym_check(handle, name, clmp, &dlmp);
1447 
1448 	if (dlmp)
1449 		is_dep_ready(dlmp, clmp, DBG_WAIT_SYMBOL);
1450 
1451 	if (entry && dlmp)
1452 		is_dep_init(dlmp, clmp);
1453 
1454 	if (entry)
1455 		leave(LIST(clmp));
1456 	return (addr);
1457 }
1458 
1459 /*
1460  * Core dladdr activity.
1461  */
1462 static void
1463 dladdr_core(Rt_map *clmp, void *addr, Dl_info *dlip, void **info, int flags)
1464 {
1465 	/*
1466 	 * Set up generic information and any defaults.
1467 	 */
1468 	dlip->dli_fname = PATHNAME(clmp);
1469 
1470 	dlip->dli_fbase = (void *)ADDR(clmp);
1471 	dlip->dli_sname = 0;
1472 	dlip->dli_saddr = 0;
1473 
1474 	/*
1475 	 * Determine the nearest symbol to this address.
1476 	 */
1477 	LM_DLADDR(clmp)((ulong_t)addr, clmp, dlip, info, flags);
1478 }
1479 
1480 #pragma weak dladdr = _dladdr
1481 
1482 /*
1483  * External entry for dladdr(3dl) and dladdr1(3dl).  Returns an information
1484  * structure that reflects the symbol closest to the address specified.
1485  */
1486 int
1487 _dladdr(void *addr, Dl_info *dlip)
1488 {
1489 	int	entry, error;
1490 	Rt_map	*clmp;
1491 
1492 	entry = enter();
1493 
1494 	/*
1495 	 * Use our calling technique to determine what object is associated
1496 	 * with the supplied address.  If a caller can't be determined,
1497 	 * indicate the failure.
1498 	 */
1499 	if ((clmp = _caller((caddr_t)addr, CL_NONE)) == 0) {
1500 		eprintf(0, ERR_FATAL, MSG_INTL(MSG_ARG_INVADDR),
1501 		    EC_NATPTR(addr));
1502 		error = 0;
1503 	} else {
1504 		dladdr_core(clmp, addr, dlip, 0, 0);
1505 		error = 1;
1506 	}
1507 
1508 	if (entry)
1509 		leave(0);
1510 	return (error);
1511 }
1512 
1513 #pragma weak dladdr1 = _dladdr1
1514 
1515 int
1516 _dladdr1(void *addr, Dl_info *dlip, void **info, int flags)
1517 {
1518 	int	entry, error = 0;
1519 	Rt_map	*clmp;
1520 
1521 	/*
1522 	 * Validate any flags.
1523 	 */
1524 	if (flags) {
1525 		int	request;
1526 
1527 		if (((request = (flags & RTLD_DL_MASK)) != RTLD_DL_SYMENT) &&
1528 		    (request != RTLD_DL_LINKMAP)) {
1529 			eprintf(0, ERR_FATAL, MSG_INTL(MSG_ARG_ILLFLAGS),
1530 			    flags);
1531 			return (0);
1532 		}
1533 		if (info == 0) {
1534 			eprintf(0, ERR_FATAL, MSG_INTL(MSG_ARG_ILLINFO), flags);
1535 			return (0);
1536 		}
1537 	}
1538 
1539 	entry = enter();
1540 
1541 	/*
1542 	 * Use our calling technique to determine what object is associated
1543 	 * with the supplied address.  If a caller can't be determined,
1544 	 * indicate the failure.
1545 	 */
1546 	if ((clmp = _caller((caddr_t)addr, CL_NONE)) == 0) {
1547 		eprintf(0, ERR_FATAL, MSG_INTL(MSG_ARG_INVADDR),
1548 		    EC_NATPTR(addr));
1549 		error = 0;
1550 	} else {
1551 		dladdr_core(clmp, addr, dlip, info, flags);
1552 		error = 1;
1553 	}
1554 
1555 	if (entry)
1556 		leave(0);
1557 	return (error);
1558 }
1559 
1560 /*
1561  * Core dldump activity.
1562  */
1563 static int
1564 dldump_core(Lm_list *lml, const char *ipath, const char *opath, int flags)
1565 {
1566 	Addr	addr = 0;
1567 	Rt_map	*lmp;
1568 
1569 	/*
1570 	 * Verify any arguments first.
1571 	 */
1572 	if ((!opath || (*opath == '\0')) || (ipath && (*ipath == '\0'))) {
1573 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLPATH));
1574 		return (1);
1575 	}
1576 
1577 	/*
1578 	 * If an input file is specified make sure its one of our dependencies
1579 	 * on the main link-map list.  Note, this has really all evolved for
1580 	 * crle(), which uses libcrle.so on an alternative link-map to trigger
1581 	 * dumping objects from the main link-map list.   If we ever want to
1582 	 * dump objects from alternative link-maps, this model is going to
1583 	 * have to be revisited.
1584 	 */
1585 	if (ipath) {
1586 		if ((lmp = is_so_loaded(&lml_main, ipath, NULL)) == 0) {
1587 			eprintf(lml, ERR_FATAL, MSG_INTL(MSG_GEN_NOFILE),
1588 			    ipath);
1589 			return (1);
1590 		}
1591 		if (FLAGS(lmp) & FLG_RT_ALTER) {
1592 			eprintf(lml, ERR_FATAL, MSG_INTL(MSG_GEN_ALTER), ipath);
1593 			return (1);
1594 		}
1595 		if (FLAGS(lmp) & FLG_RT_NODUMP) {
1596 			eprintf(lml, ERR_FATAL, MSG_INTL(MSG_GEN_NODUMP),
1597 			    ipath);
1598 			return (1);
1599 		}
1600 	} else
1601 		lmp = lml_main.lm_head;
1602 
1603 
1604 	DBG_CALL(Dbg_file_dldump(lmp, opath, flags));
1605 
1606 	/*
1607 	 * If the object being dump'ed isn't fixed identify its mapping.
1608 	 */
1609 	if (!(FLAGS(lmp) & FLG_RT_FIXED))
1610 		addr = ADDR(lmp);
1611 
1612 	/*
1613 	 * As rt_dldump() will effectively lazy load the necessary support
1614 	 * libraries, make sure ld.so.1 is initialized for plt relocations.
1615 	 */
1616 	if (elf_rtld_load() == 0)
1617 		return (0);
1618 
1619 	/*
1620 	 * Dump the required image.
1621 	 */
1622 	return (rt_dldump(lmp, opath, flags, addr));
1623 }
1624 
1625 #pragma weak dldump = _dldump
1626 
1627 /*
1628  * External entry for dldump(3c).  Returns 0 on success, non-zero otherwise.
1629  */
1630 int
1631 _dldump(const char *ipath, const char *opath, int flags)
1632 {
1633 	int	error, entry;
1634 	Rt_map	*clmp;
1635 
1636 	entry = enter();
1637 
1638 	clmp = _caller(caller(), CL_EXECDEF);
1639 
1640 	error = dldump_core(LIST(clmp), ipath, opath, flags);
1641 
1642 	if (entry)
1643 		leave(LIST(clmp));
1644 	return (error);
1645 }
1646 
1647 /*
1648  * get_linkmap_id() translates Lm_list * pointers to the Link_map id as used by
1649  * the rtld_db and dlmopen() interfaces.  It checks to see if the Link_map is
1650  * one of the primary ones and if so returns it's special token:
1651  *		LM_ID_BASE
1652  *		LM_ID_LDSO
1653  *
1654  * If it's not one of the primary link_map id's it will instead returns a
1655  * pointer to the Lm_list structure which uniquely identifies the Link_map.
1656  */
1657 Lmid_t
1658 get_linkmap_id(Lm_list *lml)
1659 {
1660 	if (lml->lm_flags & LML_FLG_BASELM)
1661 		return (LM_ID_BASE);
1662 	if (lml->lm_flags & LML_FLG_RTLDLM)
1663 		return (LM_ID_LDSO);
1664 
1665 	return ((Lmid_t)lml);
1666 }
1667 
1668 /*
1669  * Extract information for a dlopen() handle.
1670  */
1671 static int
1672 dlinfo_core(void *handle, int request, void *p, Rt_map *clmp)
1673 {
1674 	Lm_list	*lml = LIST(clmp);
1675 	Rt_map	*lmp;
1676 
1677 	if ((request > RTLD_DI_MAX) || (p == 0)) {
1678 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLVAL));
1679 		return (-1);
1680 	}
1681 
1682 	/*
1683 	 * Return configuration cache name and address.
1684 	 */
1685 	if (request == RTLD_DI_CONFIGADDR) {
1686 		Dl_info	*dlip = (Dl_info *)p;
1687 
1688 		if ((config->c_name == 0) || (config->c_bgn == 0) ||
1689 		    (config->c_end == 0)) {
1690 			eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_NOCONFIG));
1691 			return (-1);
1692 		}
1693 		dlip->dli_fname = config->c_name;
1694 		dlip->dli_fbase = (void *)config->c_bgn;
1695 		return (0);
1696 	}
1697 
1698 	/*
1699 	 * Return profiled object name (used by ldprof audit library).
1700 	 */
1701 	if (request == RTLD_DI_PROFILENAME) {
1702 		if (profile_name == 0) {
1703 			eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_NOPROFNAME));
1704 			return (-1);
1705 		}
1706 
1707 		*(const char **)p = profile_name;
1708 		return (0);
1709 	}
1710 	if (request == RTLD_DI_PROFILEOUT) {
1711 		/*
1712 		 * If a profile destination directory hasn't been specified
1713 		 * provide a default.
1714 		 */
1715 		if (profile_out == 0)
1716 			profile_out = MSG_ORIG(MSG_PTH_VARTMP);
1717 
1718 		*(const char **)p = profile_out;
1719 		return (0);
1720 	}
1721 
1722 	/*
1723 	 * Obtain or establish a termination signal.
1724 	 */
1725 	if (request == RTLD_DI_GETSIGNAL) {
1726 		*(int *)p = killsig;
1727 		return (0);
1728 	}
1729 
1730 	if (request == RTLD_DI_SETSIGNAL) {
1731 		sigset_t	set;
1732 		int		sig = *(int *)p;
1733 
1734 		/*
1735 		 * Determine whether the signal is in range.
1736 		 */
1737 		(void) sigfillset(&set);
1738 		if (sigismember(&set, sig) != 1) {
1739 			eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_INVSIG), sig);
1740 			return (-1);
1741 		}
1742 
1743 		killsig = sig;
1744 		return (0);
1745 	}
1746 
1747 	/*
1748 	 * For any other request a link-map is required.  Verify the handle.
1749 	 */
1750 	if (handle == RTLD_SELF)
1751 		lmp = clmp;
1752 	else {
1753 		Grp_hdl	*ghp = (Grp_hdl *)handle;
1754 
1755 		if (!hdl_validate(ghp)) {
1756 			eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_INVHNDL));
1757 			return (-1);
1758 		}
1759 		lmp = ghp->gh_ownlmp;
1760 	}
1761 
1762 	/*
1763 	 * Obtain the process arguments, environment and auxv.  Note, as the
1764 	 * environment can be modified by the user (putenv(3c)), reinitialize
1765 	 * the environment pointer on each request.
1766 	 */
1767 	if (request == RTLD_DI_ARGSINFO) {
1768 		Dl_argsinfo	*aip = (Dl_argsinfo *)p;
1769 		Lm_list		*lml = LIST(lmp);
1770 
1771 		*aip = argsinfo;
1772 		if (lml->lm_flags & LML_FLG_ENVIRON)
1773 			aip->dla_envp = *(lml->lm_environ);
1774 
1775 		return (0);
1776 	}
1777 
1778 	/*
1779 	 * Return Lmid_t of the Link-Map list that the specified object is
1780 	 * loaded on.
1781 	 */
1782 	if (request == RTLD_DI_LMID) {
1783 		*(Lmid_t *)p = get_linkmap_id(LIST(lmp));
1784 		return (0);
1785 	}
1786 
1787 	/*
1788 	 * Return a pointer to the Link-Map structure associated with the
1789 	 * specified object.
1790 	 */
1791 	if (request == RTLD_DI_LINKMAP) {
1792 		*(Link_map **)p = (Link_map *)lmp;
1793 		return (0);
1794 	}
1795 
1796 	/*
1797 	 * Return search path information, or the size of the buffer required
1798 	 * to store the information.
1799 	 */
1800 	if ((request == RTLD_DI_SERINFO) || (request == RTLD_DI_SERINFOSIZE)) {
1801 		Pnode		*dir, *dirlist = (Pnode *)0;
1802 		Dl_serinfo	*info;
1803 		Dl_serpath	*path;
1804 		char		*strs;
1805 		size_t		size = sizeof (Dl_serinfo);
1806 		uint_t		cnt = 0;
1807 
1808 		info = (Dl_serinfo *)p;
1809 		path = &info->dls_serpath[0];
1810 		strs = (char *)&info->dls_serpath[info->dls_cnt];
1811 
1812 		/*
1813 		 * Traverse search path entries for this object.
1814 		 */
1815 		while ((dir = get_next_dir(&dirlist, lmp, 0)) != 0) {
1816 			size_t	_size;
1817 
1818 			if (dir->p_name == 0)
1819 				continue;
1820 
1821 			/*
1822 			 * If configuration information exists, it's possible
1823 			 * this path has been identified as non-existent, if so
1824 			 * ignore it.
1825 			 */
1826 			if (dir->p_info) {
1827 				Rtc_obj	*dobj = (Rtc_obj *)dir->p_info;
1828 				if (dobj->co_flags & RTC_OBJ_NOEXIST)
1829 					continue;
1830 			}
1831 
1832 			/*
1833 			 * Keep track of search path count and total info size.
1834 			 */
1835 			if (cnt++)
1836 				size += sizeof (Dl_serpath);
1837 			_size = strlen(dir->p_name) + 1;
1838 			size += _size;
1839 
1840 			if (request == RTLD_DI_SERINFOSIZE)
1841 				continue;
1842 
1843 			/*
1844 			 * If we're filling in search path information, confirm
1845 			 * there's sufficient space.
1846 			 */
1847 			if (size > info->dls_size) {
1848 				eprintf(lml, ERR_FATAL,
1849 				    MSG_INTL(MSG_ARG_SERSIZE),
1850 				    EC_OFF(info->dls_size));
1851 				return (-1);
1852 			}
1853 			if (cnt > info->dls_cnt) {
1854 				eprintf(lml, ERR_FATAL,
1855 				    MSG_INTL(MSG_ARG_SERCNT), info->dls_cnt);
1856 				return (-1);
1857 			}
1858 
1859 			/*
1860 			 * Append the path to the information buffer.
1861 			 */
1862 			(void) strcpy(strs, dir->p_name);
1863 			path->dls_name = strs;
1864 			path->dls_flags = dir->p_orig;
1865 
1866 			strs = strs + _size;
1867 			path++;
1868 		}
1869 
1870 		/*
1871 		 * If we're here to size the search buffer fill it in.
1872 		 */
1873 		if (request == RTLD_DI_SERINFOSIZE) {
1874 			info->dls_size = size;
1875 			info->dls_cnt = cnt;
1876 		}
1877 	}
1878 
1879 	/*
1880 	 * Return the origin of the object associated with this link-map.
1881 	 * Basically return the dirname(1) of the objects fullpath.
1882 	 */
1883 	if (request == RTLD_DI_ORIGIN) {
1884 		char	*str = (char *)p;
1885 
1886 		if (DIRSZ(lmp) == 0)
1887 			(void) fullpath(lmp, 0);
1888 
1889 		(void) strncpy(str, ORIGNAME(lmp), DIRSZ(lmp));
1890 		str += DIRSZ(lmp);
1891 		*str = '\0';
1892 
1893 		return (0);
1894 	}
1895 
1896 	return (0);
1897 }
1898 
1899 #pragma weak dlinfo = _dlinfo
1900 
1901 /*
1902  * External entry for dlinfo(3dl).
1903  */
1904 int
1905 _dlinfo(void *handle, int request, void *p)
1906 {
1907 	int	error, entry;
1908 	Rt_map	*clmp;
1909 
1910 	entry = enter();
1911 
1912 	clmp = _caller(caller(), CL_EXECDEF);
1913 
1914 	error = dlinfo_core(handle, request, p, clmp);
1915 
1916 	if (entry)
1917 		leave(LIST(clmp));
1918 	return (error);
1919 }
1920