1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright (c) 1988 AT&T
24 * All Rights Reserved
25 *
26 * Copyright (c) 1990, 2010, Oracle and/or its affiliates. All rights reserved.
27 * Copyright (c) 2012, Joyent, Inc. All rights reserved.
28 */
29
30 /*
31 * Programmatic interface to the run_time linker.
32 */
33
34 #include <sys/debug.h>
35 #include <stdio.h>
36 #include <string.h>
37 #include <dlfcn.h>
38 #include <synch.h>
39 #include <limits.h>
40 #include <debug.h>
41 #include <conv.h>
42 #include "_rtld.h"
43 #include "_audit.h"
44 #include "_elf.h"
45 #include "_inline_gen.h"
46 #include "msg.h"
47
48 /*
49 * Determine who called us - given a pc determine in which object it resides.
50 *
51 * For dlopen() the link map of the caller must be passed to load_so() so that
52 * the appropriate search rules (4.x or 5.0) are used to locate any
53 * dependencies. Also, if we've been called from a 4.x module it may be
54 * necessary to fix the specified pathname so that it conforms with the 5.0 elf
55 * rules.
56 *
57 * For dlsym() the link map of the caller is used to determine RTLD_NEXT
58 * requests, together with requests based off of a dlopen(0).
59 * For dladdr() this routines provides a generic means of scanning all loaded
60 * segments.
61 */
62 Rt_map *
63 _caller(caddr_t cpc, int flags)
64 {
65 Lm_list *lml;
66 Aliste idx1;
67
68 for (APLIST_TRAVERSE(dynlm_list, idx1, lml)) {
69 Aliste idx2;
70 Lm_cntl *lmc;
71
72 for (ALIST_TRAVERSE(lml->lm_lists, idx2, lmc)) {
73 Rt_map *lmp;
74
75 for (lmp = lmc->lc_head; lmp;
76 lmp = NEXT_RT_MAP(lmp)) {
77
78 if (find_segment(cpc, lmp))
79 return (lmp);
80 }
81 }
82 }
83
84 /*
85 * No mapping can be determined. If asked for a default, assume this
86 * is from the executable.
87 */
88 if (flags & CL_EXECDEF)
89 return ((Rt_map *)lml_main.lm_head);
90
91 return (0);
92 }
93
94 #pragma weak _dlerror = dlerror
95
96 /*
97 * External entry for dlerror(3dl). Returns a pointer to the string describing
98 * the last occurring error. The last occurring error is cleared.
99 */
100 char *
101 dlerror()
102 {
103 char *error;
104 Rt_map *clmp;
105 int entry;
106
107 entry = enter(0);
108
109 clmp = _caller(caller(), CL_EXECDEF);
110
111 DBG_CALL(Dbg_dl_dlerror(clmp, lasterr));
112
113 error = lasterr;
114 lasterr = NULL;
115
116 if (entry)
117 leave(LIST(clmp), 0);
118 return (error);
119 }
120
121 /*
122 * Add a dependency as a group descriptor to a group handle. Returns 0 on
123 * failure. On success, returns the group descriptor, and if alep is non-NULL
124 * the *alep is set to ALE_EXISTS if the dependency already exists, or to
125 * ALE_CREATE if the dependency is newly created.
126 */
127 Grp_desc *
128 hdl_add(Grp_hdl *ghp, Rt_map *lmp, uint_t dflags, int *alep)
129 {
130 Grp_desc *gdp;
131 Aliste idx;
132 int ale = ALE_CREATE;
133 uint_t oflags;
134
135 /*
136 * Make sure this dependency hasn't already been recorded.
137 */
138 for (ALIST_TRAVERSE(ghp->gh_depends, idx, gdp)) {
139 if (gdp->gd_depend == lmp) {
140 ale = ALE_EXISTS;
141 break;
142 }
143 }
144
145 if (ale == ALE_CREATE) {
146 Grp_desc gd;
147
148 /*
149 * Create a new handle descriptor.
150 */
151 gd.gd_depend = lmp;
152 gd.gd_flags = 0;
153
154 /*
155 * Indicate this object is a part of this handles group.
156 */
157 if (aplist_append(&GROUPS(lmp), ghp, AL_CNT_GROUPS) == NULL)
158 return (NULL);
159
160 /*
161 * Append the new dependency to this handle.
162 */
163 if ((gdp = alist_append(&ghp->gh_depends, &gd,
164 sizeof (Grp_desc), AL_CNT_DEPENDS)) == NULL)
165 return (NULL);
166 }
167
168 oflags = gdp->gd_flags;
169 gdp->gd_flags |= dflags;
170
171 if (DBG_ENABLED) {
172 if (ale == ALE_CREATE)
173 DBG_CALL(Dbg_file_hdl_action(ghp, lmp, DBG_DEP_ADD,
174 gdp->gd_flags));
175 else if (gdp->gd_flags != oflags)
176 DBG_CALL(Dbg_file_hdl_action(ghp, lmp, DBG_DEP_UPDATE,
177 gdp->gd_flags));
178 }
179
180 if (alep)
181 *alep = ale;
182 return (gdp);
183 }
184
185 /*
186 * Create a handle.
187 *
188 * rlmp - represents the reference link-map for which the handle is being
189 * created.
190 * clmp - represents the caller who is requesting the handle.
191 * hflags - provide group handle flags (GPH_*) that affect the use of the
192 * handle, such as dlopen(0), or use or use of RTLD_FIRST.
193 * rdflags - provide group dependency flags for the reference link-map rlmp,
194 * such as whether the dependency can be used for dlsym(), can be
195 * relocated against, or whether this objects dependencies should
196 * be processed.
197 * cdflags - provide group dependency flags for the caller.
198 */
199 Grp_hdl *
200 hdl_create(Lm_list *lml, Rt_map *rlmp, Rt_map *clmp, uint_t hflags,
201 uint_t rdflags, uint_t cdflags)
202 {
203 Grp_hdl *ghp = NULL, *aghp;
204 APlist **alpp;
205 Aliste idx;
206
207 /*
208 * For dlopen(0) the handle is maintained as part of the link-map list,
209 * otherwise the handle is associated with the reference link-map.
210 */
211 if (hflags & GPH_ZERO)
212 alpp = &(lml->lm_handle);
213 else
214 alpp = &(HANDLES(rlmp));
215
216 /*
217 * Objects can contain multiple handles depending on the handle flags
218 * supplied. Most RTLD flags pertain to the object itself and the
219 * bindings that it can achieve. Multiple handles for these flags
220 * don't make sense. But if the flag determines how the handle might
221 * be used, then multiple handles may exist. Presently this only makes
222 * sense for RTLD_FIRST. Determine if an appropriate handle already
223 * exists.
224 */
225 for (APLIST_TRAVERSE(*alpp, idx, aghp)) {
226 if ((aghp->gh_flags & GPH_FIRST) == (hflags & GPH_FIRST)) {
227 ghp = aghp;
228 break;
229 }
230 }
231
232 if (ghp == NULL) {
233 uint_t ndx;
234
235 /*
236 * If this is the first request for this handle, allocate and
237 * initialize a new handle.
238 */
239 DBG_CALL(Dbg_file_hdl_title(DBG_HDL_CREATE));
240
241 if ((ghp = malloc(sizeof (Grp_hdl))) == NULL)
242 return (NULL);
243
244 /*
245 * Associate the handle with the link-map list or the reference
246 * link-map as appropriate.
247 */
248 if (aplist_append(alpp, ghp, AL_CNT_GROUPS) == NULL) {
249 free(ghp);
250 return (NULL);
251 }
252
253 /*
254 * Record the existence of this handle for future verification.
255 */
256 /* LINTED */
257 ndx = (uintptr_t)ghp % HDLIST_SZ;
258
259 if (aplist_append(&hdl_alp[ndx], ghp, AL_CNT_HANDLES) == NULL) {
260 (void) aplist_delete_value(*alpp, ghp);
261 free(ghp);
262 return (NULL);
263 }
264
265 ghp->gh_depends = NULL;
266 ghp->gh_refcnt = 1;
267 ghp->gh_flags = hflags;
268
269 /*
270 * A dlopen(0) handle is identified by the GPH_ZERO flag, the
271 * head of the link-map list is defined as the owner. There is
272 * no need to maintain a list of dependencies, for when this
273 * handle is used (for dlsym()) a dynamic search through the
274 * entire link-map list provides for searching all objects with
275 * GLOBAL visibility.
276 */
277 if (hflags & GPH_ZERO) {
278 ghp->gh_ownlmp = lml->lm_head;
279 ghp->gh_ownlml = lml;
280 } else {
281 ghp->gh_ownlmp = rlmp;
282 ghp->gh_ownlml = LIST(rlmp);
283
284 if (hdl_add(ghp, rlmp, rdflags, NULL) == NULL)
285 return (NULL);
286
287 /*
288 * If this new handle is a private handle, there's no
289 * need to track the caller, so we're done.
290 */
291 if (hflags & GPH_PRIVATE)
292 return (ghp);
293
294 /*
295 * If this new handle is public, and isn't a special
296 * handle representing ld.so.1, indicate that a local
297 * group now exists. This state allows singleton
298 * searches to be optimized.
299 */
300 if ((hflags & GPH_LDSO) == 0)
301 LIST(rlmp)->lm_flags |= LML_FLG_GROUPSEXIST;
302 }
303 } else {
304 /*
305 * If a handle already exists, bump its reference count.
306 *
307 * If the previous reference count was 0, then this is a handle
308 * that an earlier call to dlclose() was unable to remove. Such
309 * handles are put on the orphan list. As this handle is back
310 * in use, it must be removed from the orphan list.
311 *
312 * Note, handles associated with a link-map list itself (i.e.
313 * dlopen(0)) can have a reference count of 0. However, these
314 * handles are never deleted, and therefore are never moved to
315 * the orphan list.
316 */
317 if ((ghp->gh_refcnt++ == 0) &&
318 ((ghp->gh_flags & GPH_ZERO) == 0)) {
319 uint_t ndx;
320
321 /* LINTED */
322 ndx = (uintptr_t)ghp % HDLIST_SZ;
323
324 (void) aplist_delete_value(hdl_alp[HDLIST_ORP], ghp);
325 (void) aplist_append(&hdl_alp[ndx], ghp,
326 AL_CNT_HANDLES);
327
328 if (DBG_ENABLED) {
329 Aliste idx;
330 Grp_desc *gdp;
331
332 DBG_CALL(Dbg_file_hdl_title(DBG_HDL_REINST));
333 for (ALIST_TRAVERSE(ghp->gh_depends, idx, gdp))
334 DBG_CALL(Dbg_file_hdl_action(ghp,
335 gdp->gd_depend, DBG_DEP_REINST, 0));
336 }
337 }
338
339 /*
340 * If we've been asked to create a private handle, there's no
341 * need to track the caller.
342 */
343 if (hflags & GPH_PRIVATE) {
344 /*
345 * Negate the reference count increment.
346 */
347 ghp->gh_refcnt--;
348 return (ghp);
349 } else {
350 /*
351 * If a private handle already exists, promote this
352 * handle to public by initializing both the reference
353 * count and the handle flags.
354 */
355 if (ghp->gh_flags & GPH_PRIVATE) {
356 ghp->gh_refcnt = 1;
357 ghp->gh_flags &= ~GPH_PRIVATE;
358 ghp->gh_flags |= hflags;
359 }
360 }
361 }
362
363 /*
364 * Keep track of the parent (caller). As this object can be referenced
365 * by different parents, this processing is carried out every time a
366 * handle is requested.
367 */
368 if (clmp && (hdl_add(ghp, clmp, cdflags, NULL) == NULL))
369 return (NULL);
370
371 return (ghp);
372 }
373
374 /*
375 * Initialize a handle that has been created for an object that is already
376 * loaded. The handle is initialized with the present dependencies of that
377 * object. Once this initialization has occurred, any new objects that might
378 * be loaded as dependencies (lazy-loading) are added to the handle as each new
379 * object is loaded.
380 */
381 int
382 hdl_initialize(Grp_hdl *ghp, Rt_map *nlmp, int mode, int promote)
383 {
384 Aliste idx;
385 Grp_desc *gdp;
386
387 /*
388 * If the handle has already been initialized, and the initial object's
389 * mode hasn't been promoted, there's no need to recompute the modes of
390 * any dependencies. If the object we've added has just been opened,
391 * the objects dependencies will not yet have been processed. These
392 * dependencies will be added on later calls to load_one(). Otherwise,
393 * this object already exists, so add all of its dependencies to the
394 * handle were operating on.
395 */
396 if (((ghp->gh_flags & GPH_INITIAL) && (promote == 0)) ||
397 ((FLAGS(nlmp) & FLG_RT_ANALYZED) == 0)) {
398 ghp->gh_flags |= GPH_INITIAL;
399 return (1);
400 }
401
402 DBG_CALL(Dbg_file_hdl_title(DBG_HDL_ADD));
403 for (ALIST_TRAVERSE(ghp->gh_depends, idx, gdp)) {
404 Rt_map *lmp = gdp->gd_depend;
405 Aliste idx1;
406 Bnd_desc *bdp;
407
408 /*
409 * If this dependency doesn't indicate that its dependencies
410 * should be added to a handle, ignore it. This case identifies
411 * a parent of a dlopen(RTLD_PARENT) request.
412 */
413 if ((gdp->gd_flags & GPD_ADDEPS) == 0)
414 continue;
415
416 for (APLIST_TRAVERSE(DEPENDS(lmp), idx1, bdp)) {
417 Rt_map *dlmp = bdp->b_depend;
418
419 if ((bdp->b_flags & BND_NEEDED) == 0)
420 continue;
421
422 if (hdl_add(ghp, dlmp,
423 (GPD_DLSYM | GPD_RELOC | GPD_ADDEPS), NULL) == NULL)
424 return (0);
425
426 (void) update_mode(dlmp, MODE(dlmp), mode);
427 }
428 }
429 ghp->gh_flags |= GPH_INITIAL;
430 return (1);
431 }
432
433 /*
434 * Sanity check a program-provided handle.
435 */
436 static int
437 hdl_validate(Grp_hdl *ghp)
438 {
439 Aliste idx;
440 Grp_hdl *lghp;
441 uint_t ndx;
442
443 /* LINTED */
444 ndx = (uintptr_t)ghp % HDLIST_SZ;
445
446 for (APLIST_TRAVERSE(hdl_alp[ndx], idx, lghp)) {
447 if ((lghp == ghp) && (ghp->gh_refcnt != 0))
448 return (1);
449 }
450 return (0);
451 }
452
453 /*
454 * Core dlclose activity.
455 */
456 int
457 dlclose_core(Grp_hdl *ghp, Rt_map *clmp, Lm_list *lml)
458 {
459 int error;
460 Rt_map *lmp;
461
462 /*
463 * If we're already at atexit() there's no point processing further,
464 * all objects have already been tsorted for fini processing.
465 */
466 if (rtld_flags & RT_FL_ATEXIT)
467 return (0);
468
469 /*
470 * Diagnose what we're up to.
471 */
472 if (ghp->gh_flags & GPH_ZERO) {
473 DBG_CALL(Dbg_dl_dlclose(clmp, MSG_ORIG(MSG_STR_ZERO),
474 DBG_DLCLOSE_IGNORE));
475 } else {
476 DBG_CALL(Dbg_dl_dlclose(clmp, NAME(ghp->gh_ownlmp),
477 DBG_DLCLOSE_NULL));
478 }
479
480 /*
481 * Decrement reference count of this object.
482 */
483 if (--(ghp->gh_refcnt))
484 return (0);
485
486 /*
487 * If this handle is special (dlopen(0)), then leave it around - it
488 * has little overhead.
489 */
490 if (ghp->gh_flags & GPH_ZERO)
491 return (0);
492
493 /*
494 * If this handle is associated with an object that is not on the base
495 * link-map control list, or it has not yet been relocated, then this
496 * handle must have originated from an auditors interaction, or some
497 * permutation of RTLD_CONFGEN use (crle(1), moe(1), etc.). User code
498 * can only execute and bind to relocated objects on the base link-map
499 * control list. Outside of RTLD_CONFGEN use, a non-relocated object,
500 * or an object on a non-base link-map control list, is in the process
501 * of being loaded, and therefore we do not attempt to remove the
502 * handle.
503 */
504 if (((lmp = ghp->gh_ownlmp) != NULL) &&
505 ((MODE(lmp) & RTLD_CONFGEN) == 0) &&
506 ((CNTL(lmp) != ALIST_OFF_DATA) ||
507 ((FLAGS(lmp) & FLG_RT_RELOCED) == 0)))
508 return (0);
509
510 /*
511 * This handle is no longer being referenced, remove it. If this handle
512 * is part of an alternative link-map list, determine if the whole list
513 * can be removed also.
514 */
515 error = remove_hdl(ghp, clmp, NULL);
516
517 if ((lml->lm_flags & (LML_FLG_BASELM | LML_FLG_RTLDLM)) == 0)
518 remove_lml(lml);
519
520 return (error);
521 }
522
523 /*
524 * Internal dlclose activity. Called from user level or directly for internal
525 * error cleanup.
526 */
527 int
528 dlclose_intn(Grp_hdl *ghp, Rt_map *clmp)
529 {
530 Rt_map *nlmp = NULL;
531 Lm_list *olml = NULL;
532 int error;
533
534 /*
535 * Although we're deleting object(s) it's quite possible that additional
536 * objects get loaded from running the .fini section(s) of the objects
537 * being deleted. These objects will have been added to the same
538 * link-map list as those objects being deleted. Remember this list
539 * for later investigation.
540 */
541 olml = ghp->gh_ownlml;
542
543 error = dlclose_core(ghp, clmp, olml);
544
545 /*
546 * Determine whether the original link-map list still exists. In the
547 * case of a dlclose of an alternative (dlmopen) link-map the whole
548 * list may have been removed.
549 */
550 if (olml) {
551 Aliste idx;
552 Lm_list *lml;
553
554 for (APLIST_TRAVERSE(dynlm_list, idx, lml)) {
555 if (olml == lml) {
556 nlmp = olml->lm_head;
557 break;
558 }
559 }
560 }
561 load_completion(nlmp);
562 return (error);
563 }
564
565 /*
566 * Argument checking for dlclose. Only called via external entry.
567 */
568 static int
569 dlclose_check(void *handle, Rt_map *clmp)
570 {
571 Grp_hdl *ghp = (Grp_hdl *)handle;
572
573 if (hdl_validate(ghp) == 0) {
574 Conv_inv_buf_t inv_buf;
575
576 (void) conv_invalid_val(&inv_buf, EC_NATPTR(ghp), 0);
577 DBG_CALL(Dbg_dl_dlclose(clmp, inv_buf.buf, DBG_DLCLOSE_NULL));
578
579 eprintf(LIST(clmp), ERR_FATAL, MSG_INTL(MSG_ARG_INVHNDL),
580 EC_NATPTR(handle));
581 return (1);
582 }
583 return (dlclose_intn(ghp, clmp));
584 }
585
586 #pragma weak _dlclose = dlclose
587
588 /*
589 * External entry for dlclose(3dl). Returns 0 for success, non-zero otherwise.
590 */
591 int
592 dlclose(void *handle)
593 {
594 int error, entry;
595 Rt_map *clmp;
596
597 entry = enter(0);
598
599 clmp = _caller(caller(), CL_EXECDEF);
600
601 error = dlclose_check(handle, clmp);
602
603 if (entry)
604 leave(LIST(clmp), 0);
605 return (error);
606 }
607
608 static uint_t lmid = 0;
609
610 /*
611 * The addition of new link-map lists is assumed to be in small quantities.
612 * Here, we assign a unique link-map id for diagnostic use. Simply update the
613 * running link-map count until we max out.
614 */
615 int
616 newlmid(Lm_list *lml)
617 {
618 char buffer[MSG_LMID_ALT_SIZE + 12];
619
620 if (lmid == UINT_MAX) {
621 lml->lm_lmid = UINT_MAX;
622 (void) strncpy(buffer, MSG_ORIG(MSG_LMID_MAXED),
623 MSG_LMID_ALT_SIZE + 12);
624 } else {
625 lml->lm_lmid = lmid++;
626 (void) snprintf(buffer, MSG_LMID_ALT_SIZE + 12,
627 MSG_ORIG(MSG_LMID_FMT), MSG_ORIG(MSG_LMID_ALT),
628 lml->lm_lmid);
629 }
630 if ((lml->lm_lmidstr = strdup(buffer)) == NULL)
631 return (0);
632
633 return (1);
634 }
635
636 /*
637 * Core dlopen activity.
638 */
639 static Grp_hdl *
640 dlmopen_core(Lm_list *lml, Lm_list *olml, const char *path, int mode,
641 Rt_map *clmp, uint_t flags, uint_t orig, int *in_nfavl)
642 {
643 Alist *palp = NULL;
644 Rt_map *nlmp;
645 Grp_hdl *ghp;
646 Aliste olmco, nlmco;
647
648 DBG_CALL(Dbg_dl_dlopen(clmp,
649 (path ? path : MSG_ORIG(MSG_STR_ZERO)), in_nfavl, mode));
650
651 /*
652 * Having diagnosed the originally defined modes, assign any defaults
653 * or corrections.
654 */
655 if (((mode & (RTLD_GROUP | RTLD_WORLD)) == 0) &&
656 ((mode & RTLD_NOLOAD) == 0))
657 mode |= (RTLD_GROUP | RTLD_WORLD);
658 if ((mode & RTLD_NOW) && (rtld_flags2 & RT_FL2_BINDLAZY)) {
659 mode &= ~RTLD_NOW;
660 mode |= RTLD_LAZY;
661 }
662
663 /*
664 * If the path specified is null then we're operating on global
665 * objects. Associate a dummy handle with the link-map list.
666 */
667 if (path == NULL) {
668 Grp_hdl *ghp;
669 uint_t hflags, rdflags, cdflags;
670 int promote = 0;
671
672 /*
673 * Establish any flags for the handle (Grp_hdl).
674 *
675 * - This is a dummy, public, handle (0) that provides for a
676 * dynamic search of all global objects within the process.
677 * - Use of the RTLD_FIRST mode indicates that only the first
678 * dependency on the handle (the referenced object) can be
679 * used to satisfy dlsym() requests.
680 */
681 hflags = (GPH_PUBLIC | GPH_ZERO);
682 if (mode & RTLD_FIRST)
683 hflags |= GPH_FIRST;
684
685 /*
686 * Establish the flags for the referenced dependency descriptor
687 * (Grp_desc).
688 *
689 * - The referenced object is available for dlsym().
690 * - The referenced object is available to relocate against.
691 * - The referenced object should have it's dependencies
692 * added to this handle.
693 */
694 rdflags = (GPD_DLSYM | GPD_RELOC | GPD_ADDEPS);
695
696 /*
697 * Establish the flags for this callers dependency descriptor
698 * (Grp_desc).
699 *
700 * - The explicit creation of a handle creates a descriptor
701 * for the referenced object and the parent (caller).
702 * - Use of the RTLD_PARENT flag indicates that the parent
703 * can be relocated against.
704 */
705 cdflags = GPD_PARENT;
706 if (mode & RTLD_PARENT)
707 cdflags |= GPD_RELOC;
708
709 if ((ghp = hdl_create(lml, 0, clmp, hflags, rdflags,
710 cdflags)) == NULL)
711 return (NULL);
712
713 /*
714 * Traverse the main link-map control list, updating the mode
715 * of any objects as necessary. Call the relocation engine if
716 * this mode promotes the existing state of any relocations.
717 * crle()'s first pass loads all objects necessary for building
718 * a configuration file, however none of them are relocated.
719 * crle()'s second pass relocates objects in preparation for
720 * dldump()'ing using dlopen(0, RTLD_NOW).
721 */
722 if ((mode & (RTLD_NOW | RTLD_CONFGEN)) == RTLD_CONFGEN)
723 return (ghp);
724
725 for (nlmp = lml->lm_head; nlmp; nlmp = NEXT_RT_MAP(nlmp)) {
726 if (((MODE(nlmp) & RTLD_GLOBAL) == 0) ||
727 (FLAGS(nlmp) & FLG_RT_DELETE))
728 continue;
729
730 if (update_mode(nlmp, MODE(nlmp), mode))
731 promote = 1;
732 }
733 if (promote)
734 (void) relocate_lmc(lml, ALIST_OFF_DATA, clmp,
735 lml->lm_head, in_nfavl);
736
737 return (ghp);
738 }
739
740 /*
741 * Fix the pathname. If this object expands to multiple paths (ie.
742 * $ISALIST or $HWCAP have been used), then make sure the user has also
743 * furnished the RTLD_FIRST flag. As yet, we don't support opening
744 * more than one object at a time, so enforcing the RTLD_FIRST flag
745 * provides flexibility should we be able to support dlopening more
746 * than one object in the future.
747 */
748 if (LM_FIX_NAME(clmp)(path, clmp, &palp, AL_CNT_NEEDED, orig) == NULL)
749 return (NULL);
750
751 if ((palp->al_arritems > 1) && ((mode & RTLD_FIRST) == 0)) {
752 remove_alist(&palp, 1);
753 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLMODE_5));
754 return (NULL);
755 }
756
757 /*
758 * Establish a link-map control list for this request, and load the
759 * associated object.
760 */
761 if ((nlmco = create_cntl(lml, 1)) == NULL) {
762 remove_alist(&palp, 1);
763 return (NULL);
764 }
765 olmco = nlmco;
766
767 nlmp = load_one(lml, nlmco, palp, clmp, mode, (flags | FLG_RT_PUBHDL),
768 &ghp, in_nfavl);
769
770 /*
771 * Remove any expanded pathname infrastructure, and if the dependency
772 * couldn't be loaded, cleanup.
773 */
774 remove_alist(&palp, 1);
775 if (nlmp == NULL) {
776 remove_cntl(lml, olmco);
777 return (NULL);
778 }
779
780 /*
781 * If loading an auditor was requested, and the auditor already existed,
782 * then the link-map returned will be to the original auditor. The new
783 * link-map list that was initially created, and the associated link-map
784 * control list are no longer needed. As the auditor is already loaded,
785 * we're probably done, but fall through in case additional relocations
786 * would be triggered by the mode of the caller.
787 */
788 if ((flags & FLG_RT_AUDIT) && (LIST(nlmp) != lml)) {
789 remove_cntl(lml, olmco);
790 lml = LIST(nlmp);
791 olmco = 0;
792 nlmco = ALIST_OFF_DATA;
793 }
794
795 /*
796 * Finish processing the objects associated with this request.
797 */
798 if (((nlmp = analyze_lmc(lml, nlmco, nlmp, clmp, in_nfavl)) == NULL) ||
799 (relocate_lmc(lml, nlmco, clmp, nlmp, in_nfavl) == 0)) {
800 ghp = NULL;
801 nlmp = NULL;
802 }
803
804 /*
805 * If the dlopen has failed, clean up any objects that might have been
806 * loaded successfully on this new link-map control list.
807 */
808 if (olmco && (nlmp == NULL))
809 remove_lmc(lml, clmp, olmco, path);
810
811 /*
812 * Finally, remove any temporary link-map control list. Note, if this
813 * operation successfully established a new link-map list, then a base
814 * link-map control list will have been created, which must remain.
815 */
816 if (olmco && ((nlmp == NULL) || (olml != (Lm_list *)LM_ID_NEWLM)))
817 remove_cntl(lml, olmco);
818
819 return (ghp);
820 }
821
822 /*
823 * dlopen() and dlsym() operations are the means by which a process can
824 * test for the existence of required dependencies. If the necessary
825 * dependencies don't exist, then associated functionality can't be used.
826 * However, the lack of dependencies can be fixed, and the dlopen() and
827 * dlsym() requests can be repeated. As we use a "not-found" AVL tree to
828 * cache any failed full path loads, secondary dlopen() and dlsym() requests
829 * will fail, even if the dependencies have been installed.
830 *
831 * dlopen() and dlsym() retry any failures by removing the "not-found" AVL
832 * tree. Should any dependencies be found, their names are added to the
833 * FullPath AVL tree. This routine removes any new "not-found" AVL tree,
834 * so that the dlopen() or dlsym() can replace the original "not-found" tree.
835 */
836 inline static void
837 nfavl_remove(avl_tree_t *avlt)
838 {
839 PathNode *pnp;
840 void *cookie = NULL;
841
842 if (avlt) {
843 while ((pnp = avl_destroy_nodes(avlt, &cookie)) != NULL)
844 free(pnp);
845
846 avl_destroy(avlt);
847 free(avlt);
848 }
849 }
850
851 /*
852 * Internal dlopen() activity. Called from user level or directly for internal
853 * opens that require a handle.
854 */
855 Grp_hdl *
856 dlmopen_intn(Lm_list *lml, const char *path, int mode, Rt_map *clmp,
857 uint_t flags, uint_t orig)
858 {
859 Lm_list *olml = lml;
860 Rt_map *dlmp = NULL;
861 Grp_hdl *ghp;
862 int in_nfavl = 0;
863
864 /*
865 * Check for magic link-map list values:
866 *
867 * LM_ID_BASE: Operate on the PRIMARY (executables) link map
868 * LM_ID_LDSO: Operation on ld.so.1's link map
869 * LM_ID_NEWLM: Create a new link-map.
870 */
871 if (lml == (Lm_list *)LM_ID_NEWLM) {
872 if ((lml = calloc(1, sizeof (Lm_list))) == NULL)
873 return (NULL);
874
875 /*
876 * Establish the new link-map flags from the callers and those
877 * explicitly provided.
878 */
879 lml->lm_tflags = LIST(clmp)->lm_tflags;
880 if (flags & FLG_RT_AUDIT) {
881 /*
882 * Unset any auditing flags - an auditor shouldn't be
883 * audited. Insure all audit dependencies are loaded.
884 */
885 lml->lm_tflags &= ~LML_TFLG_AUD_MASK;
886 lml->lm_tflags |= (LML_TFLG_NOLAZYLD |
887 LML_TFLG_LOADFLTR | LML_TFLG_NOAUDIT);
888 }
889
890 if (aplist_append(&dynlm_list, lml, AL_CNT_DYNLIST) == NULL) {
891 free(lml);
892 return (NULL);
893 }
894 if (newlmid(lml) == 0) {
895 (void) aplist_delete_value(dynlm_list, lml);
896 free(lml);
897 return (NULL);
898 }
899 } else if ((uintptr_t)lml < LM_ID_NUM) {
900 if ((uintptr_t)lml == LM_ID_BASE)
901 lml = &lml_main;
902 else if ((uintptr_t)lml == LM_ID_LDSO)
903 lml = &lml_rtld;
904 }
905
906 /*
907 * Open the required object on the associated link-map list.
908 */
909 ghp = dlmopen_core(lml, olml, path, mode, clmp, flags, orig, &in_nfavl);
910
911 /*
912 * If the object could not be found it is possible that the "not-found"
913 * AVL tree had indicated that the file does not exist. In case the
914 * file system has changed since this "not-found" recording was made,
915 * retry the dlopen() with a clean "not-found" AVL tree.
916 */
917 if ((ghp == NULL) && in_nfavl) {
918 avl_tree_t *oavlt = nfavl;
919
920 nfavl = NULL;
921 ghp = dlmopen_core(lml, olml, path, mode, clmp, flags, orig,
922 NULL);
923
924 /*
925 * If the file is found, then its full path name will have been
926 * registered in the FullPath AVL tree. Remove any new
927 * "not-found" AVL information, and restore the former AVL tree.
928 */
929 nfavl_remove(nfavl);
930 nfavl = oavlt;
931 }
932
933 /*
934 * Establish the new link-map from which .init processing will begin.
935 * Ignore .init firing when constructing a configuration file (crle(1)).
936 */
937 if (ghp && ((mode & RTLD_CONFGEN) == 0))
938 dlmp = ghp->gh_ownlmp;
939
940 /*
941 * If loading an auditor was requested, and the auditor already existed,
942 * then the link-map returned will be to the original auditor. Remove
943 * the link-map control list that was created for this request.
944 */
945 if (dlmp && (flags & FLG_RT_AUDIT) && (LIST(dlmp) != lml)) {
946 remove_lml(lml);
947 lml = LIST(dlmp);
948 }
949
950 /*
951 * If this load failed, remove any alternative link-map list.
952 */
953 if ((ghp == NULL) &&
954 ((lml->lm_flags & (LML_FLG_BASELM | LML_FLG_RTLDLM)) == 0)) {
955 remove_lml(lml);
956 lml = NULL;
957 }
958
959 /*
960 * Finish this load request. If objects were loaded, .init processing
961 * is computed. Finally, the debuggers are informed of the link-map
962 * lists being stable.
963 */
964 load_completion(dlmp);
965
966 return (ghp);
967 }
968
969 /*
970 * Argument checking for dlopen. Only called via external entry.
971 */
972 static Grp_hdl *
973 dlmopen_check(Lm_list *lml, const char *path, int mode, Rt_map *clmp)
974 {
975 /*
976 * Verify that a valid pathname has been supplied.
977 */
978 if (path && (*path == '\0')) {
979 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLPATH));
980 return (0);
981 }
982
983 /*
984 * Historically we've always verified the mode is either RTLD_NOW or
985 * RTLD_LAZY. RTLD_NOLOAD is valid by itself. Use of LM_ID_NEWLM
986 * requires a specific pathname, and use of RTLD_PARENT is meaningless.
987 */
988 if ((mode & (RTLD_NOW | RTLD_LAZY | RTLD_NOLOAD)) == 0) {
989 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLMODE_1));
990 return (0);
991 }
992 if ((mode & (RTLD_NOW | RTLD_LAZY)) == (RTLD_NOW | RTLD_LAZY)) {
993 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLMODE_2));
994 return (0);
995 }
996 if ((lml == (Lm_list *)LM_ID_NEWLM) && (path == NULL)) {
997 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLMODE_3));
998 return (0);
999 }
1000 if ((lml == (Lm_list *)LM_ID_NEWLM) && (mode & RTLD_PARENT)) {
1001 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLMODE_4));
1002 return (0);
1003 }
1004
1005 return (dlmopen_intn(lml, path, mode, clmp, 0, 0));
1006 }
1007
1008 #pragma weak _dlopen = dlopen
1009
1010 /*
1011 * External entry for dlopen(3dl). On success, returns a pointer (handle) to
1012 * the structure containing information about the newly added object, ie. can
1013 * be used by dlsym(). On failure, returns a null pointer.
1014 */
1015 void *
1016 dlopen(const char *path, int mode)
1017 {
1018 int entry;
1019 Rt_map *clmp;
1020 Grp_hdl *ghp;
1021 Lm_list *lml;
1022
1023 entry = enter(0);
1024
1025 clmp = _caller(caller(), CL_EXECDEF);
1026 lml = LIST(clmp);
1027
1028 ghp = dlmopen_check(lml, path, mode, clmp);
1029
1030 if (entry)
1031 leave(lml, 0);
1032 return ((void *)ghp);
1033 }
1034
1035 #pragma weak _dlmopen = dlmopen
1036
1037 /*
1038 * External entry for dlmopen(3dl).
1039 */
1040 void *
1041 dlmopen(Lmid_t lmid, const char *path, int mode)
1042 {
1043 int entry;
1044 Rt_map *clmp;
1045 Grp_hdl *ghp;
1046
1047 entry = enter(0);
1048
1049 clmp = _caller(caller(), CL_EXECDEF);
1050
1051 ghp = dlmopen_check((Lm_list *)lmid, path, mode, clmp);
1052
1053 if (entry)
1054 leave(LIST(clmp), 0);
1055 return ((void *)ghp);
1056 }
1057
1058 /*
1059 * Handle processing for dlsym.
1060 */
1061 int
1062 dlsym_handle(Grp_hdl *ghp, Slookup *slp, Sresult *srp, uint_t *binfo,
1063 int *in_nfavl)
1064 {
1065 Rt_map *nlmp, * lmp = ghp->gh_ownlmp;
1066 Rt_map *clmp = slp->sl_cmap;
1067 const char *name = slp->sl_name;
1068 Slookup sl = *slp;
1069
1070 sl.sl_flags = (LKUP_FIRST | LKUP_DLSYM | LKUP_SPEC);
1071
1072 /*
1073 * Continue processing a dlsym request. Lookup the required symbol in
1074 * each link-map specified by the handle.
1075 *
1076 * To leverage off of lazy loading, dlsym() requests can result in two
1077 * passes. The first descends the link-maps of any objects already in
1078 * the address space. If the symbol isn't located, and lazy
1079 * dependencies still exist, then a second pass is made to load these
1080 * dependencies if applicable. This model means that in the case where
1081 * a symbol exists in more than one object, the one located may not be
1082 * constant - this is the standard issue with lazy loading. In addition,
1083 * attempting to locate a symbol that doesn't exist will result in the
1084 * loading of all lazy dependencies on the given handle, which can
1085 * defeat some of the advantages of lazy loading (look out JVM).
1086 */
1087 if (ghp->gh_flags & GPH_ZERO) {
1088 Lm_list *lml;
1089 uint_t lazy = 0;
1090
1091 /*
1092 * If this symbol lookup is triggered from a dlopen(0) handle,
1093 * traverse the present link-map list looking for promiscuous
1094 * entries.
1095 */
1096 for (nlmp = lmp; nlmp; nlmp = NEXT_RT_MAP(nlmp)) {
1097 /*
1098 * If this handle indicates we're only to look in the
1099 * first object check whether we're done.
1100 */
1101 if ((nlmp != lmp) && (ghp->gh_flags & GPH_FIRST))
1102 return (0);
1103
1104 if (!(MODE(nlmp) & RTLD_GLOBAL))
1105 continue;
1106 if ((FLAGS(nlmp) & FLG_RT_DELETE) &&
1107 ((FLAGS(clmp) & FLG_RT_DELETE) == 0))
1108 continue;
1109
1110 sl.sl_imap = nlmp;
1111 if (LM_LOOKUP_SYM(clmp)(&sl, srp, binfo, in_nfavl))
1112 return (1);
1113
1114 /*
1115 * Keep track of any global pending lazy loads.
1116 */
1117 lazy += LAZY(nlmp);
1118 }
1119
1120 /*
1121 * If we're unable to locate the symbol and this link-map list
1122 * still has pending lazy dependencies, start loading them in an
1123 * attempt to exhaust the search. Note that as we're already
1124 * traversing a dynamic linked list of link-maps there's no
1125 * need for elf_lazy_find_sym() to descend the link-maps itself.
1126 */
1127 lml = LIST(lmp);
1128 if (lazy) {
1129 DBG_CALL(Dbg_syms_lazy_rescan(lml, name));
1130
1131 sl.sl_flags |= LKUP_NODESCENT;
1132
1133 for (nlmp = lmp; nlmp; nlmp = NEXT_RT_MAP(nlmp)) {
1134
1135 if (!(MODE(nlmp) & RTLD_GLOBAL) || !LAZY(nlmp))
1136 continue;
1137 if ((FLAGS(nlmp) & FLG_RT_DELETE) &&
1138 ((FLAGS(clmp) & FLG_RT_DELETE) == 0))
1139 continue;
1140
1141 sl.sl_imap = nlmp;
1142 if (elf_lazy_find_sym(&sl, srp, binfo,
1143 in_nfavl))
1144 return (1);
1145 }
1146 }
1147 } else {
1148 /*
1149 * Traverse the dlopen() handle searching all presently loaded
1150 * link-maps.
1151 */
1152 Grp_desc *gdp;
1153 Aliste idx;
1154 uint_t lazy = 0;
1155
1156 for (ALIST_TRAVERSE(ghp->gh_depends, idx, gdp)) {
1157 nlmp = gdp->gd_depend;
1158
1159 if ((gdp->gd_flags & GPD_DLSYM) == 0)
1160 continue;
1161
1162 sl.sl_imap = nlmp;
1163 if (LM_LOOKUP_SYM(clmp)(&sl, srp, binfo, in_nfavl))
1164 return (1);
1165
1166 if (ghp->gh_flags & GPH_FIRST)
1167 return (0);
1168
1169 /*
1170 * Keep track of any pending lazy loads associated
1171 * with this handle.
1172 */
1173 lazy += LAZY(nlmp);
1174 }
1175
1176 /*
1177 * If we're unable to locate the symbol and this handle still
1178 * has pending lazy dependencies, start loading the lazy
1179 * dependencies, in an attempt to exhaust the search.
1180 */
1181 if (lazy) {
1182 DBG_CALL(Dbg_syms_lazy_rescan(LIST(lmp), name));
1183
1184 for (ALIST_TRAVERSE(ghp->gh_depends, idx, gdp)) {
1185 nlmp = gdp->gd_depend;
1186
1187 if (((gdp->gd_flags & GPD_DLSYM) == 0) ||
1188 (LAZY(nlmp) == 0))
1189 continue;
1190
1191 sl.sl_imap = nlmp;
1192 if (elf_lazy_find_sym(&sl, srp, binfo,
1193 in_nfavl))
1194 return (1);
1195 }
1196 }
1197 }
1198 return (0);
1199 }
1200
1201 /*
1202 * Determine whether a symbol resides in a caller. This may be a reference,
1203 * which is associated with a specific dependency.
1204 */
1205 inline static Sym *
1206 sym_lookup_in_caller(Rt_map *clmp, Slookup *slp, Sresult *srp, uint_t *binfo)
1207 {
1208 if (THIS_IS_ELF(clmp) && SYMINTP(clmp)(slp, srp, binfo, NULL)) {
1209 Sym *sym = srp->sr_sym;
1210
1211 slp->sl_rsymndx = (((ulong_t)sym -
1212 (ulong_t)SYMTAB(clmp)) / SYMENT(clmp));
1213 slp->sl_rsym = sym;
1214 return (sym);
1215 }
1216 return (NULL);
1217 }
1218
1219 /*
1220 * Core dlsym activity. Selects symbol lookup method from handle.
1221 */
1222 static void *
1223 dlsym_core(void *handle, const char *name, Rt_map *clmp, Rt_map **dlmp,
1224 int *in_nfavl)
1225 {
1226 Sym *sym;
1227 int ret = 0;
1228 Syminfo *sip;
1229 Slookup sl;
1230 Sresult sr;
1231 uint_t binfo;
1232
1233 /*
1234 * Initialize the symbol lookup data structure.
1235 *
1236 * Standard relocations are evaluated using the symbol index of the
1237 * associated relocation symbol. This index provides for loading
1238 * any lazy dependency and establishing a direct binding if necessary.
1239 * If a dlsym() operation originates from an object that contains a
1240 * symbol table entry for the same name, then we need to establish the
1241 * symbol index so that any dependency requirements can be triggered.
1242 *
1243 * Therefore, the first symbol lookup that is carried out is for the
1244 * symbol name within the calling object. If this symbol exists, the
1245 * symbols index is computed, added to the Slookup data, and thus used
1246 * to seed the real symbol lookup.
1247 */
1248 SLOOKUP_INIT(sl, name, clmp, clmp, ld_entry_cnt, elf_hash(name),
1249 0, 0, 0, LKUP_SYMNDX);
1250 SRESULT_INIT(sr, name);
1251 sym = sym_lookup_in_caller(clmp, &sl, &sr, &binfo);
1252
1253 SRESULT_INIT(sr, name);
1254
1255 if (sym && (ELF_ST_VISIBILITY(sym->st_other) == STV_SINGLETON)) {
1256 Rt_map *hlmp = LIST(clmp)->lm_head;
1257
1258 /*
1259 * If a symbol reference is known, and that reference indicates
1260 * that the symbol is a singleton, then the search for the
1261 * symbol must follow the default search path.
1262 */
1263 DBG_CALL(Dbg_dl_dlsym(clmp, name, in_nfavl, 0,
1264 DBG_DLSYM_SINGLETON));
1265
1266 sl.sl_imap = hlmp;
1267 if (handle == RTLD_PROBE)
1268 sl.sl_flags = LKUP_NOFALLBACK;
1269 else
1270 sl.sl_flags = LKUP_SPEC;
1271 ret = LM_LOOKUP_SYM(clmp)(&sl, &sr, &binfo, in_nfavl);
1272
1273 } else if (handle == RTLD_NEXT) {
1274 Rt_map *nlmp;
1275
1276 /*
1277 * If this handle is RTLD_NEXT determine whether a lazy load
1278 * from the caller might provide the next object. This mimics
1279 * the lazy loading initialization normally carried out by
1280 * lookup_sym(), however here, we must do this up-front, as
1281 * lookup_sym() will be used to inspect the next object.
1282 */
1283 if ((sl.sl_rsymndx) && ((sip = SYMINFO(clmp)) != NULL)) {
1284 /* LINTED */
1285 sip = (Syminfo *)((char *)sip +
1286 (sl.sl_rsymndx * SYMINENT(clmp)));
1287
1288 if ((sip->si_flags & SYMINFO_FLG_DIRECT) &&
1289 (sip->si_boundto < SYMINFO_BT_LOWRESERVE))
1290 (void) elf_lazy_load(clmp, &sl,
1291 sip->si_boundto, name, 0, NULL, in_nfavl);
1292
1293 /*
1294 * Clear the symbol index, so as not to confuse
1295 * lookup_sym() of the next object.
1296 */
1297 sl.sl_rsymndx = 0;
1298 sl.sl_rsym = NULL;
1299 }
1300
1301 /*
1302 * If the handle is RTLD_NEXT, start searching in the next link
1303 * map from the callers. Determine permissions from the
1304 * present link map. Indicate to lookup_sym() that we're on an
1305 * RTLD_NEXT request so that it will use the callers link map to
1306 * start any possible lazy dependency loading.
1307 */
1308 sl.sl_imap = nlmp = NEXT_RT_MAP(clmp);
1309
1310 DBG_CALL(Dbg_dl_dlsym(clmp, name, in_nfavl,
1311 (nlmp ? NAME(nlmp) : MSG_INTL(MSG_STR_NULL)),
1312 DBG_DLSYM_NEXT));
1313
1314 if (nlmp == NULL)
1315 return (0);
1316
1317 sl.sl_flags = LKUP_NEXT;
1318 ret = LM_LOOKUP_SYM(clmp)(&sl, &sr, &binfo, in_nfavl);
1319
1320 } else if (handle == RTLD_SELF) {
1321 /*
1322 * If the handle is RTLD_SELF start searching from the caller.
1323 */
1324 DBG_CALL(Dbg_dl_dlsym(clmp, name, in_nfavl, NAME(clmp),
1325 DBG_DLSYM_SELF));
1326
1327 sl.sl_imap = clmp;
1328 sl.sl_flags = (LKUP_SPEC | LKUP_SELF);
1329 ret = LM_LOOKUP_SYM(clmp)(&sl, &sr, &binfo, in_nfavl);
1330
1331 } else if (handle == RTLD_DEFAULT) {
1332 Rt_map *hlmp = LIST(clmp)->lm_head;
1333
1334 /*
1335 * If the handle is RTLD_DEFAULT mimic the standard symbol
1336 * lookup as would be triggered by a relocation.
1337 */
1338 DBG_CALL(Dbg_dl_dlsym(clmp, name, in_nfavl, 0,
1339 DBG_DLSYM_DEFAULT));
1340
1341 sl.sl_imap = hlmp;
1342 sl.sl_flags = LKUP_SPEC;
1343 ret = LM_LOOKUP_SYM(clmp)(&sl, &sr, &binfo, in_nfavl);
1344
1345 } else if (handle == RTLD_PROBE) {
1346 Rt_map *hlmp = LIST(clmp)->lm_head;
1347
1348 /*
1349 * If the handle is RTLD_PROBE, mimic the standard symbol
1350 * lookup as would be triggered by a relocation, however do
1351 * not fall back to a lazy loading rescan if the symbol can't be
1352 * found within the currently loaded objects. Note, a lazy
1353 * loaded dependency required by the caller might still get
1354 * loaded to satisfy this request, but no exhaustive lazy load
1355 * rescan is carried out.
1356 */
1357 DBG_CALL(Dbg_dl_dlsym(clmp, name, in_nfavl, 0,
1358 DBG_DLSYM_PROBE));
1359
1360 sl.sl_imap = hlmp;
1361 sl.sl_flags = LKUP_NOFALLBACK;
1362 ret = LM_LOOKUP_SYM(clmp)(&sl, &sr, &binfo, in_nfavl);
1363
1364 } else {
1365 Grp_hdl *ghp = (Grp_hdl *)handle;
1366
1367 /*
1368 * Look in the shared object specified by the handle and in all
1369 * of its dependencies.
1370 */
1371 DBG_CALL(Dbg_dl_dlsym(clmp, name, in_nfavl,
1372 NAME(ghp->gh_ownlmp), DBG_DLSYM_DEF));
1373
1374 ret = LM_DLSYM(clmp)(ghp, &sl, &sr, &binfo, in_nfavl);
1375 }
1376
1377 if (ret && ((sym = sr.sr_sym) != NULL)) {
1378 Lm_list *lml = LIST(clmp);
1379 Addr addr = sym->st_value;
1380
1381 *dlmp = sr.sr_dmap;
1382 if (!(FLAGS(*dlmp) & FLG_RT_FIXED))
1383 addr += ADDR(*dlmp);
1384
1385 /*
1386 * Indicate that the defining object is now used.
1387 */
1388 if (*dlmp != clmp)
1389 FLAGS1(*dlmp) |= FL1_RT_USED;
1390
1391 DBG_CALL(Dbg_bind_global(clmp, 0, 0, (Xword)-1, PLT_T_NONE,
1392 *dlmp, addr, sym->st_value, sr.sr_name, binfo));
1393
1394 if ((lml->lm_tflags | AFLAGS(clmp) | AFLAGS(*dlmp)) &
1395 LML_TFLG_AUD_SYMBIND) {
1396 uint_t sb_flags = LA_SYMB_DLSYM;
1397 /* LINTED */
1398 uint_t symndx = (uint_t)(((Xword)sym -
1399 (Xword)SYMTAB(*dlmp)) / SYMENT(*dlmp));
1400 addr = audit_symbind(clmp, *dlmp, sym, symndx, addr,
1401 &sb_flags);
1402 }
1403 return ((void *)addr);
1404 }
1405
1406 return (NULL);
1407 }
1408
1409 /*
1410 * Internal dlsym activity. Called from user level or directly for internal
1411 * symbol lookup.
1412 */
1413 void *
1414 dlsym_intn(void *handle, const char *name, Rt_map *clmp, Rt_map **dlmp)
1415 {
1416 Rt_map *llmp = NULL;
1417 void *error;
1418 Aliste idx;
1419 Grp_desc *gdp;
1420 int in_nfavl = 0;
1421
1422 /*
1423 * While looking for symbols it's quite possible that additional objects
1424 * get loaded from lazy loading. These objects will have been added to
1425 * the same link-map list as those objects on the handle. Remember this
1426 * list for later investigation.
1427 */
1428 if ((handle == RTLD_NEXT) || (handle == RTLD_DEFAULT) ||
1429 (handle == RTLD_SELF) || (handle == RTLD_PROBE))
1430 llmp = LIST(clmp)->lm_tail;
1431 else {
1432 Grp_hdl *ghp = (Grp_hdl *)handle;
1433
1434 if (ghp->gh_ownlmp)
1435 llmp = LIST(ghp->gh_ownlmp)->lm_tail;
1436 else {
1437 for (ALIST_TRAVERSE(ghp->gh_depends, idx, gdp)) {
1438 if ((llmp =
1439 LIST(gdp->gd_depend)->lm_tail) != NULL)
1440 break;
1441 }
1442 }
1443 }
1444
1445 error = dlsym_core(handle, name, clmp, dlmp, &in_nfavl);
1446
1447 /*
1448 * If the symbol could not be found it is possible that the "not-found"
1449 * AVL tree had indicated that a required file does not exist. In case
1450 * the file system has changed since this "not-found" recording was
1451 * made, retry the dlsym() with a clean "not-found" AVL tree.
1452 */
1453 if ((error == NULL) && in_nfavl) {
1454 avl_tree_t *oavlt = nfavl;
1455
1456 nfavl = NULL;
1457 error = dlsym_core(handle, name, clmp, dlmp, NULL);
1458
1459 /*
1460 * If the symbol is found, then any file that was loaded will
1461 * have had its full path name registered in the FullPath AVL
1462 * tree. Remove any new "not-found" AVL information, and
1463 * restore the former AVL tree.
1464 */
1465 nfavl_remove(nfavl);
1466 nfavl = oavlt;
1467 }
1468
1469 if (error == NULL) {
1470 /*
1471 * Cache the error message, as Java tends to fall through this
1472 * code many times.
1473 */
1474 if (nosym_str == NULL)
1475 nosym_str = MSG_INTL(MSG_GEN_NOSYM);
1476 eprintf(LIST(clmp), ERR_FATAL, nosym_str, name);
1477 }
1478
1479 load_completion(llmp);
1480 return (error);
1481 }
1482
1483 /*
1484 * Argument checking for dlsym. Only called via external entry.
1485 */
1486 static void *
1487 dlsym_check(void *handle, const char *name, Rt_map *clmp, Rt_map **dlmp)
1488 {
1489 /*
1490 * Verify the arguments.
1491 */
1492 if (name == NULL) {
1493 eprintf(LIST(clmp), ERR_FATAL, MSG_INTL(MSG_ARG_ILLSYM));
1494 return (NULL);
1495 }
1496 if ((handle != RTLD_NEXT) && (handle != RTLD_DEFAULT) &&
1497 (handle != RTLD_SELF) && (handle != RTLD_PROBE) &&
1498 (hdl_validate((Grp_hdl *)handle) == 0)) {
1499 eprintf(LIST(clmp), ERR_FATAL, MSG_INTL(MSG_ARG_INVHNDL),
1500 EC_NATPTR(handle));
1501 return (NULL);
1502 }
1503 return (dlsym_intn(handle, name, clmp, dlmp));
1504 }
1505
1506
1507 #pragma weak _dlsym = dlsym
1508
1509 /*
1510 * External entry for dlsym(). On success, returns the address of the specified
1511 * symbol. On error returns a null.
1512 */
1513 void *
1514 dlsym(void *handle, const char *name)
1515 {
1516 int entry;
1517 Rt_map *clmp, *dlmp = NULL;
1518 void *addr;
1519
1520 entry = enter(0);
1521
1522 clmp = _caller(caller(), CL_EXECDEF);
1523
1524 addr = dlsym_check(handle, name, clmp, &dlmp);
1525
1526 if (entry) {
1527 if (dlmp)
1528 is_dep_init(dlmp, clmp);
1529 leave(LIST(clmp), 0);
1530 }
1531 return (addr);
1532 }
1533
1534 /*
1535 * Core dladdr activity.
1536 */
1537 static void
1538 dladdr_core(Rt_map *almp, void *addr, Dl_info_t *dlip, void **info, int flags)
1539 {
1540 /*
1541 * Set up generic information and any defaults.
1542 */
1543 dlip->dli_fname = PATHNAME(almp);
1544
1545 dlip->dli_fbase = (void *)ADDR(almp);
1546 dlip->dli_sname = NULL;
1547 dlip->dli_saddr = NULL;
1548
1549 /*
1550 * Determine the nearest symbol to this address.
1551 */
1552 LM_DLADDR(almp)((ulong_t)addr, almp, dlip, info, flags);
1553 }
1554
1555 #pragma weak _dladdr = dladdr
1556
1557 /*
1558 * External entry for dladdr(3dl) and dladdr1(3dl). Returns an information
1559 * structure that reflects the symbol closest to the address specified.
1560 */
1561 int
1562 dladdr(void *addr, Dl_info_t *dlip)
1563 {
1564 int entry, ret;
1565 Rt_map *clmp, *almp;
1566 Lm_list *clml;
1567
1568 entry = enter(0);
1569
1570 clmp = _caller(caller(), CL_EXECDEF);
1571 clml = LIST(clmp);
1572
1573 DBG_CALL(Dbg_dl_dladdr(clmp, addr));
1574
1575 /*
1576 * Use our calling technique to determine what object is associated
1577 * with the supplied address. If a caller can't be determined,
1578 * indicate the failure.
1579 */
1580 if ((almp = _caller(addr, CL_NONE)) == NULL) {
1581 eprintf(clml, ERR_FATAL, MSG_INTL(MSG_ARG_INVADDR),
1582 EC_NATPTR(addr));
1583 ret = 0;
1584 } else {
1585 dladdr_core(almp, addr, dlip, 0, 0);
1586 ret = 1;
1587 }
1588
1589 if (entry)
1590 leave(clml, 0);
1591 return (ret);
1592 }
1593
1594 #pragma weak _dladdr1 = dladdr1
1595
1596 int
1597 dladdr1(void *addr, Dl_info_t *dlip, void **info, int flags)
1598 {
1599 int entry, ret = 1;
1600 Rt_map *clmp, *almp;
1601 Lm_list *clml;
1602
1603 entry = enter(0);
1604
1605 clmp = _caller(caller(), CL_EXECDEF);
1606 clml = LIST(clmp);
1607
1608 DBG_CALL(Dbg_dl_dladdr(clmp, addr));
1609
1610 /*
1611 * Validate any flags.
1612 */
1613 if (flags) {
1614 int request;
1615
1616 if (((request = (flags & RTLD_DL_MASK)) != RTLD_DL_SYMENT) &&
1617 (request != RTLD_DL_LINKMAP)) {
1618 eprintf(clml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLFLAGS),
1619 flags);
1620 ret = 0;
1621
1622 } else if (info == NULL) {
1623 eprintf(clml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLINFO),
1624 flags);
1625 ret = 0;
1626 }
1627 }
1628
1629 /*
1630 * Use our calling technique to determine what object is associated
1631 * with the supplied address. If a caller can't be determined,
1632 * indicate the failure.
1633 */
1634 if (ret) {
1635 if ((almp = _caller(addr, CL_NONE)) == NULL) {
1636 eprintf(clml, ERR_FATAL, MSG_INTL(MSG_ARG_INVADDR),
1637 EC_NATPTR(addr));
1638 ret = 0;
1639 } else
1640 dladdr_core(almp, addr, dlip, info, flags);
1641 }
1642
1643 if (entry)
1644 leave(clml, 0);
1645 return (ret);
1646 }
1647
1648 /*
1649 * Core dldump activity.
1650 */
1651 static int
1652 dldump_core(Rt_map *clmp, Rt_map *lmp, const char *ipath, const char *opath,
1653 int flags)
1654 {
1655 Lm_list *lml = LIST(clmp);
1656 Addr addr = 0;
1657
1658 /*
1659 * Verify any arguments first.
1660 */
1661 if ((opath == NULL) || (opath[0] == '\0') ||
1662 ((lmp == NULL) && (ipath[0] == '\0'))) {
1663 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLPATH));
1664 return (1);
1665 }
1666
1667 /*
1668 * If an input file is specified make sure its one of our dependencies
1669 * on the main link-map list. Note, this has really all evolved for
1670 * crle(), which uses libcrle.so on an alternative link-map to trigger
1671 * dumping objects from the main link-map list. If we ever want to
1672 * dump objects from alternative link-maps, this model is going to
1673 * have to be revisited.
1674 */
1675 if (lmp == NULL) {
1676 if ((lmp = is_so_loaded(&lml_main, ipath, NULL)) == NULL) {
1677 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_GEN_NOFILE),
1678 ipath);
1679 return (1);
1680 }
1681 if (FLAGS(lmp) & FLG_RT_ALTER) {
1682 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_GEN_ALTER), ipath);
1683 return (1);
1684 }
1685 if (FLAGS(lmp) & FLG_RT_NODUMP) {
1686 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_GEN_NODUMP),
1687 ipath);
1688 return (1);
1689 }
1690 }
1691
1692 /*
1693 * If the object being dump'ed isn't fixed identify its mapping.
1694 */
1695 if (!(FLAGS(lmp) & FLG_RT_FIXED))
1696 addr = ADDR(lmp);
1697
1698 /*
1699 * As rt_dldump() will effectively lazy load the necessary support
1700 * libraries, make sure ld.so.1 is initialized for plt relocations.
1701 */
1702 if (elf_rtld_load() == 0)
1703 return (0);
1704
1705 /*
1706 * Dump the required image.
1707 */
1708 return (rt_dldump(lmp, opath, flags, addr));
1709 }
1710
1711 #pragma weak _dldump = dldump
1712
1713 /*
1714 * External entry for dldump(3c). Returns 0 on success, non-zero otherwise.
1715 */
1716 int
1717 dldump(const char *ipath, const char *opath, int flags)
1718 {
1719 int error, entry;
1720 Rt_map *clmp, *lmp;
1721
1722 entry = enter(0);
1723
1724 clmp = _caller(caller(), CL_EXECDEF);
1725
1726 if (ipath) {
1727 lmp = NULL;
1728 } else {
1729 lmp = lml_main.lm_head;
1730 ipath = NAME(lmp);
1731 }
1732
1733 DBG_CALL(Dbg_dl_dldump(clmp, ipath, opath, flags));
1734
1735 error = dldump_core(clmp, lmp, ipath, opath, flags);
1736
1737 if (entry)
1738 leave(LIST(clmp), 0);
1739 return (error);
1740 }
1741
1742 /*
1743 * get_linkmap_id() translates Lm_list * pointers to the Link_map id as used by
1744 * the rtld_db and dlmopen() interfaces. It checks to see if the Link_map is
1745 * one of the primary ones and if so returns it's special token:
1746 * LM_ID_BASE
1747 * LM_ID_LDSO
1748 *
1749 * If it's not one of the primary link_map id's it will instead returns a
1750 * pointer to the Lm_list structure which uniquely identifies the Link_map.
1751 */
1752 Lmid_t
1753 get_linkmap_id(Lm_list *lml)
1754 {
1755 if (lml->lm_flags & LML_FLG_BASELM)
1756 return (LM_ID_BASE);
1757 if (lml->lm_flags & LML_FLG_RTLDLM)
1758 return (LM_ID_LDSO);
1759
1760 return ((Lmid_t)lml);
1761 }
1762
1763 /*
1764 * Set a new deferred dependency name.
1765 */
1766 static int
1767 set_def_need(Lm_list *lml, Dyninfo *dyip, const char *name)
1768 {
1769 /*
1770 * If this dependency has already been established, then this dlinfo()
1771 * call is too late.
1772 */
1773 if (dyip->di_info) {
1774 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_DEF_DEPLOADED),
1775 dyip->di_name);
1776 return (-1);
1777 }
1778
1779 /*
1780 * Assign the new dependency name.
1781 */
1782 DBG_CALL(Dbg_file_deferred(lml, dyip->di_name, name));
1783 dyip->di_flags |= FLG_DI_DEF_DONE;
1784 dyip->di_name = name;
1785 return (0);
1786 }
1787
1788 /*
1789 * Extract information for a dlopen() handle.
1790 */
1791 static int
1792 dlinfo_core(void *handle, int request, void *p, Rt_map *clmp)
1793 {
1794 Conv_inv_buf_t inv_buf;
1795 char *handlename;
1796 Lm_list *lml = LIST(clmp);
1797 Rt_map *lmp = NULL;
1798
1799 /*
1800 * Determine whether a handle is provided. A handle isn't needed for
1801 * all operations, but it is validated here for the initial diagnostic.
1802 */
1803 if (handle == RTLD_SELF) {
1804 lmp = clmp;
1805 } else {
1806 Grp_hdl *ghp = (Grp_hdl *)handle;
1807
1808 if (hdl_validate(ghp))
1809 lmp = ghp->gh_ownlmp;
1810 }
1811 if (lmp) {
1812 handlename = NAME(lmp);
1813 } else {
1814 (void) conv_invalid_val(&inv_buf, EC_NATPTR(handle), 0);
1815 handlename = inv_buf.buf;
1816 }
1817
1818 DBG_CALL(Dbg_dl_dlinfo(clmp, handlename, request, p));
1819
1820 /*
1821 * Validate the request and return buffer.
1822 */
1823 if ((request > RTLD_DI_MAX) || (p == NULL)) {
1824 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ILLVAL));
1825 return (-1);
1826 }
1827
1828 /*
1829 * Return configuration cache name and address.
1830 */
1831 if (request == RTLD_DI_CONFIGADDR) {
1832 Dl_info_t *dlip = (Dl_info_t *)p;
1833
1834 if ((config->c_name == NULL) || (config->c_bgn == 0) ||
1835 (config->c_end == 0)) {
1836 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_NOCONFIG));
1837 return (-1);
1838 }
1839 dlip->dli_fname = config->c_name;
1840 dlip->dli_fbase = (void *)config->c_bgn;
1841 return (0);
1842 }
1843
1844 /*
1845 * Return profiled object name (used by ldprof audit library).
1846 */
1847 if (request == RTLD_DI_PROFILENAME) {
1848 if (profile_name == NULL) {
1849 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_NOPROFNAME));
1850 return (-1);
1851 }
1852
1853 *(const char **)p = profile_name;
1854 return (0);
1855 }
1856 if (request == RTLD_DI_PROFILEOUT) {
1857 /*
1858 * If a profile destination directory hasn't been specified
1859 * provide a default.
1860 */
1861 if (profile_out == NULL)
1862 profile_out = MSG_ORIG(MSG_PTH_VARTMP);
1863
1864 *(const char **)p = profile_out;
1865 return (0);
1866 }
1867
1868 /*
1869 * Obtain or establish a termination signal.
1870 */
1871 if (request == RTLD_DI_GETSIGNAL) {
1872 *(int *)p = killsig;
1873 return (0);
1874 }
1875
1876 if (request == RTLD_DI_SETSIGNAL) {
1877 sigset_t set;
1878 int sig = *(int *)p;
1879
1880 /*
1881 * Determine whether the signal is in range.
1882 */
1883 (void) sigfillset(&set);
1884 if (sigismember(&set, sig) != 1) {
1885 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_INVSIG), sig);
1886 return (-1);
1887 }
1888
1889 killsig = sig;
1890 return (0);
1891 }
1892
1893 /*
1894 * For any other request a link-map is required. Verify the handle.
1895 */
1896 if (lmp == NULL) {
1897 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_INVHNDL),
1898 EC_NATPTR(handle));
1899 return (-1);
1900 }
1901
1902 /*
1903 * Obtain the process arguments, environment and auxv. Note, as the
1904 * environment can be modified by the user (putenv(3c)), reinitialize
1905 * the environment pointer on each request.
1906 */
1907 if (request == RTLD_DI_ARGSINFO) {
1908 Dl_argsinfo_t *aip = (Dl_argsinfo_t *)p;
1909 Lm_list *lml = LIST(lmp);
1910
1911 *aip = argsinfo;
1912 if (lml->lm_flags & LML_FLG_ENVIRON)
1913 aip->dla_envp = *(lml->lm_environ);
1914
1915 return (0);
1916 }
1917
1918 /*
1919 * Return Lmid_t of the Link-Map list that the specified object is
1920 * loaded on.
1921 */
1922 if (request == RTLD_DI_LMID) {
1923 *(Lmid_t *)p = get_linkmap_id(LIST(lmp));
1924 return (0);
1925 }
1926
1927 /*
1928 * Return a pointer to the Link-Map structure associated with the
1929 * specified object.
1930 */
1931 if (request == RTLD_DI_LINKMAP) {
1932 *(Link_map **)p = (Link_map *)lmp;
1933 return (0);
1934 }
1935
1936 /*
1937 * Return search path information, or the size of the buffer required
1938 * to store the information.
1939 */
1940 if ((request == RTLD_DI_SERINFO) || (request == RTLD_DI_SERINFOSIZE)) {
1941 Spath_desc sd = { search_rules, NULL, 0 };
1942 Pdesc *pdp;
1943 Dl_serinfo_t *info;
1944 Dl_serpath_t *path;
1945 char *strs;
1946 size_t size = sizeof (Dl_serinfo_t);
1947 uint_t cnt = 0;
1948
1949 info = (Dl_serinfo_t *)p;
1950 path = &info->dls_serpath[0];
1951 strs = (char *)&info->dls_serpath[info->dls_cnt];
1952
1953 /*
1954 * Traverse search path entries for this object.
1955 */
1956 while ((pdp = get_next_dir(&sd, lmp, 0)) != NULL) {
1957 size_t _size;
1958
1959 if (pdp->pd_pname == NULL)
1960 continue;
1961
1962 /*
1963 * If configuration information exists, it's possible
1964 * this path has been identified as non-existent, if so
1965 * ignore it.
1966 */
1967 if (pdp->pd_info) {
1968 Rtc_obj *dobj = (Rtc_obj *)pdp->pd_info;
1969 if (dobj->co_flags & RTC_OBJ_NOEXIST)
1970 continue;
1971 }
1972
1973 /*
1974 * Keep track of search path count and total info size.
1975 */
1976 if (cnt++)
1977 size += sizeof (Dl_serpath_t);
1978 _size = pdp->pd_plen + 1;
1979 size += _size;
1980
1981 if (request == RTLD_DI_SERINFOSIZE)
1982 continue;
1983
1984 /*
1985 * If we're filling in search path information, confirm
1986 * there's sufficient space.
1987 */
1988 if (size > info->dls_size) {
1989 eprintf(lml, ERR_FATAL,
1990 MSG_INTL(MSG_ARG_SERSIZE),
1991 EC_OFF(info->dls_size));
1992 return (-1);
1993 }
1994 if (cnt > info->dls_cnt) {
1995 eprintf(lml, ERR_FATAL,
1996 MSG_INTL(MSG_ARG_SERCNT), info->dls_cnt);
1997 return (-1);
1998 }
1999
2000 /*
2001 * Append the path to the information buffer.
2002 */
2003 (void) strcpy(strs, pdp->pd_pname);
2004 path->dls_name = strs;
2005 path->dls_flags = (pdp->pd_flags & LA_SER_MASK);
2006
2007 strs = strs + _size;
2008 path++;
2009 }
2010
2011 /*
2012 * If we're here to size the search buffer fill it in.
2013 */
2014 if (request == RTLD_DI_SERINFOSIZE) {
2015 info->dls_size = size;
2016 info->dls_cnt = cnt;
2017 }
2018
2019 return (0);
2020 }
2021
2022 /*
2023 * Return the origin of the object associated with this link-map.
2024 * Basically return the dirname(1) of the objects fullpath.
2025 */
2026 if (request == RTLD_DI_ORIGIN) {
2027 char *str = (char *)p;
2028
2029 (void) strncpy(str, ORIGNAME(lmp), DIRSZ(lmp));
2030 str += DIRSZ(lmp);
2031 *str = '\0';
2032
2033 return (0);
2034 }
2035
2036 /*
2037 * Return the number of object mappings, or the mapping information for
2038 * this object.
2039 */
2040 if (request == RTLD_DI_MMAPCNT) {
2041 uint_t *cnt = (uint_t *)p;
2042
2043 *cnt = MMAPCNT(lmp);
2044 return (0);
2045 }
2046 if (request == RTLD_DI_MMAPS) {
2047 Dl_mapinfo_t *mip = (Dl_mapinfo_t *)p;
2048
2049 if (mip->dlm_acnt && mip->dlm_maps) {
2050 uint_t cnt = 0;
2051
2052 while ((cnt < mip->dlm_acnt) && (cnt < MMAPCNT(lmp))) {
2053 mip->dlm_maps[cnt] = MMAPS(lmp)[cnt];
2054 cnt++;
2055 }
2056 mip->dlm_rcnt = cnt;
2057 }
2058 return (0);
2059 }
2060
2061 /*
2062 * Assign a new dependency name to a deferred dependency.
2063 */
2064 if ((request == RTLD_DI_DEFERRED) ||
2065 (request == RTLD_DI_DEFERRED_SYM)) {
2066 Dl_definfo_t *dfip = (Dl_definfo_t *)p;
2067 Dyninfo *dyip;
2068 const char *dname, *rname;
2069
2070 /*
2071 * Verify the names.
2072 */
2073 if ((dfip->dld_refname == NULL) ||
2074 (dfip->dld_depname == NULL)) {
2075 eprintf(LIST(clmp), ERR_FATAL,
2076 MSG_INTL(MSG_ARG_ILLNAME));
2077 return (-1);
2078 }
2079
2080 dname = dfip->dld_depname;
2081 rname = dfip->dld_refname;
2082
2083 /*
2084 * A deferred dependency can be determined by referencing a
2085 * symbol family member that is associated to the dependency,
2086 * or by looking for the dependency by its name.
2087 */
2088 if (request == RTLD_DI_DEFERRED_SYM) {
2089 Slookup sl;
2090 Sresult sr;
2091 uint_t binfo;
2092 Syminfo *sip;
2093
2094 /*
2095 * Lookup the symbol in the associated object.
2096 */
2097 SLOOKUP_INIT(sl, rname, lmp, lmp, ld_entry_cnt,
2098 elf_hash(rname), 0, 0, 0, LKUP_SYMNDX);
2099 SRESULT_INIT(sr, rname);
2100 if (sym_lookup_in_caller(clmp, &sl, &sr,
2101 &binfo) == NULL) {
2102 eprintf(LIST(clmp), ERR_FATAL,
2103 MSG_INTL(MSG_DEF_NOSYMFOUND), rname);
2104 return (-1);
2105 }
2106
2107 /*
2108 * Use the symbols index to reference the Syminfo entry
2109 * and thus find the associated dependency.
2110 */
2111 if (sl.sl_rsymndx && ((sip = SYMINFO(clmp)) != NULL)) {
2112 /* LINTED */
2113 sip = (Syminfo *)((char *)sip +
2114 (sl.sl_rsymndx * SYMINENT(lmp)));
2115
2116 if ((sip->si_flags & SYMINFO_FLG_DEFERRED) &&
2117 (sip->si_boundto < SYMINFO_BT_LOWRESERVE) &&
2118 ((dyip = DYNINFO(lmp)) != NULL)) {
2119 dyip += sip->si_boundto;
2120
2121 if (!(dyip->di_flags & FLG_DI_IGNORE))
2122 return (set_def_need(lml,
2123 dyip, dname));
2124 }
2125 }
2126
2127 /*
2128 * No deferred symbol found.
2129 */
2130 eprintf(LIST(clmp), ERR_FATAL,
2131 MSG_INTL(MSG_DEF_NOSYMFOUND), rname);
2132 return (-1);
2133
2134 } else {
2135 Dyn *dyn;
2136
2137 /*
2138 * Using the target objects dependency information, find
2139 * the associated deferred dependency.
2140 */
2141 for (dyn = DYN(lmp), dyip = DYNINFO(lmp);
2142 !(dyip->di_flags & FLG_DI_IGNORE); dyn++, dyip++) {
2143 const char *oname;
2144
2145 if ((dyip->di_flags & FLG_DI_DEFERRED) == 0)
2146 continue;
2147
2148 if (strcmp(rname, dyip->di_name) == 0)
2149 return (set_def_need(lml, dyip, dname));
2150
2151 /*
2152 * If this dependency name has been changed by
2153 * a previous dlinfo(), check the original
2154 * dynamic entry string. The user might be
2155 * attempting to re-change an entry using the
2156 * original name as the reference.
2157 */
2158 if ((dyip->di_flags & FLG_DI_DEF_DONE) == 0)
2159 continue;
2160
2161 oname = STRTAB(lmp) + dyn->d_un.d_val;
2162 if (strcmp(rname, oname) == 0)
2163 return (set_def_need(lml, dyip, dname));
2164 }
2165
2166 /*
2167 * No deferred dependency found.
2168 */
2169 eprintf(lml, ERR_FATAL, MSG_INTL(MSG_DEF_NODEPFOUND),
2170 rname);
2171 return (-1);
2172 }
2173 }
2174 return (0);
2175 }
2176
2177 #pragma weak _dlinfo = dlinfo
2178
2179 /*
2180 * External entry for dlinfo(3dl).
2181 */
2182 int
2183 dlinfo(void *handle, int request, void *p)
2184 {
2185 int error, entry;
2186 Rt_map *clmp;
2187
2188 entry = enter(0);
2189
2190 clmp = _caller(caller(), CL_EXECDEF);
2191
2192 error = dlinfo_core(handle, request, p, clmp);
2193
2194 if (entry)
2195 leave(LIST(clmp), 0);
2196 return (error);
2197 }
2198
2199 /*
2200 * GNU defined function to iterate through the program headers for all
2201 * currently loaded dynamic objects. The caller supplies a callback function
2202 * which is called for each object.
2203 *
2204 * entry:
2205 * callback - Callback function to call. The arguments to the callback
2206 * function are:
2207 * info - Address of dl_phdr_info structure
2208 * size - sizeof (struct dl_phdr_info)
2209 * data - Caller supplied value.
2210 * data - Value supplied by caller, which is passed to callback without
2211 * examination.
2212 *
2213 * exit:
2214 * callback is called for each dynamic ELF object in the process address
2215 * space, halting when a non-zero value is returned, or when the last
2216 * object has been processed. The return value from the last call
2217 * to callback is returned.
2218 *
2219 * note:
2220 * The Linux implementation has added additional fields to the
2221 * dl_phdr_info structure over time. The callback function is
2222 * supposed to use the size field to determine which fields are
2223 * present, and to avoid attempts to access non-existent fields.
2224 * We have added those fields that are compatible with Solaris, and
2225 * which are used by GNU C++ (g++) runtime exception handling support.
2226 *
2227 * note:
2228 * We issue a callback for every ELF object mapped into the process
2229 * address space at the time this routine is entered. These callbacks
2230 * are arbitrary functions that can do anything, including possibly
2231 * causing new objects to be mapped into the process, or unmapped.
2232 * This complicates matters:
2233 *
2234 * - Adding new objects can cause the alists to be reallocated
2235 * or for contents to move. This can happen explicitly via
2236 * dlopen(), or implicitly via lazy loading. One might consider
2237 * simply banning dlopen from a callback, but lazy loading must
2238 * be allowed, in which case there's no reason to ban dlopen().
2239 *
2240 * - Removing objects can leave us holding references to freed
2241 * memory that must not be accessed, and can cause the list
2242 * items to move in a way that would cause us to miss reporting
2243 * one, or double report others.
2244 *
2245 * - We cannot allocate memory to build a separate data structure,
2246 * because the interface to dl_iterate_phdr() does not have a
2247 * way to communicate allocation errors back to the caller.
2248 * Even if we could, it would be difficult to do so efficiently.
2249 *
2250 * - It is possible for dl_iterate_phdr() to be called recursively
2251 * from a callback, and there is no way for us to detect or manage
2252 * this effectively, particularly as the user might use longjmp()
2253 * to skip past us on return. Hence, we must be reentrant
2254 * (stateless), further precluding the option of building a
2255 * separate data structure.
2256 *
2257 * Despite these constraints, we are able to traverse the link-map
2258 * lists safely:
2259 *
2260 * - Once interposer (preload) objects have been processed at
2261 * startup, we know that new objects are always placed at the
2262 * end of the list. Hence, if we are reading a list when that
2263 * happens, the new object will not alter the part of the list
2264 * that we've already processed.
2265 *
2266 * - The alist _TRAVERSE macros recalculate the address of the
2267 * current item from scratch on each iteration, rather than
2268 * incrementing a pointer. Hence, alist additions that occur
2269 * in mid-traverse will not cause confusion.
2270 *
2271 * There is one limitation: We cannot continue operation if an object
2272 * is removed from the process from within a callback. We detect when
2273 * this happens and return immediately with a -1 return value.
2274 *
2275 * note:
2276 * As currently implemented, if a callback causes an object to be loaded,
2277 * that object may or may not be reported by the current invocation of
2278 * dl_iterate_phdr(), based on whether or not we have already processed
2279 * the link-map list that receives it. If we want to prevent this, it
2280 * can be done efficiently by associating the current value of cnt_map
2281 * with each new Rt_map entered into the system. Then this function can
2282 * use that to detect and skip new objects that enter the system in
2283 * mid-iteration. However, the Linux documentation is ambiguous on whether
2284 * this is necessary, and it does not appear to matter in practice.
2285 * We have therefore chosen not to do so at this time.
2286 */
2287 int
2288 dl_iterate_phdr(int (*callback)(struct dl_phdr_info *, size_t, void *),
2289 void *data)
2290 {
2291 struct dl_phdr_info info;
2292 u_longlong_t l_cnt_map = cnt_map;
2293 u_longlong_t l_cnt_unmap = cnt_unmap;
2294 Lm_list *lml, *clml;
2295 Lm_cntl *lmc;
2296 Rt_map *lmp, *clmp;
2297 Aliste idx1, idx2;
2298 Ehdr *ehdr;
2299 int ret = 0;
2300 int entry;
2301
2302 entry = enter(0);
2303 clmp = _caller(caller(), CL_EXECDEF);
2304 clml = LIST(clmp);
2305
2306 DBG_CALL(Dbg_dl_iphdr_enter(clmp, cnt_map, cnt_unmap));
2307
2308 /* Issue a callback for each ELF object in the process */
2309 for (APLIST_TRAVERSE(dynlm_list, idx1, lml)) {
2310 for (ALIST_TRAVERSE(lml->lm_lists, idx2, lmc)) {
2311 for (lmp = lmc->lc_head; lmp; lmp = NEXT_RT_MAP(lmp)) {
2312 #if defined(_sparc) && !defined(_LP64)
2313 /*
2314 * On 32-bit sparc, the possibility exists that
2315 * this object is not ELF.
2316 */
2317 if (THIS_IS_NOT_ELF(lmp))
2318 continue;
2319 #endif
2320 /* Prepare the object information structure */
2321 ehdr = (Ehdr *) ADDR(lmp);
2322 info.dlpi_addr = (ehdr->e_type == ET_EXEC) ?
2323 0 : ADDR(lmp);
2324 info.dlpi_name = lmp->rt_pathname;
2325 info.dlpi_phdr = (Phdr *)
2326 (ADDR(lmp) + ehdr->e_phoff);
2327 info.dlpi_phnum = ehdr->e_phnum;
2328 info.dlpi_adds = cnt_map;
2329 info.dlpi_subs = cnt_unmap;
2330
2331 /* Issue the callback */
2332 DBG_CALL(Dbg_dl_iphdr_callback(clml, &info));
2333 leave(clml, thr_flg_reenter);
2334 ret = (* callback)(&info, sizeof (info), data);
2335 (void) enter(thr_flg_reenter);
2336
2337 /* Return immediately on non-zero result */
2338 if (ret != 0)
2339 goto done;
2340
2341 /* Adapt to object mapping changes */
2342 if ((cnt_map == l_cnt_map) &&
2343 (cnt_unmap == l_cnt_unmap))
2344 continue;
2345
2346 DBG_CALL(Dbg_dl_iphdr_mapchange(clml, cnt_map,
2347 cnt_unmap));
2348
2349 /* Stop if an object was unmapped */
2350 if (cnt_unmap == l_cnt_unmap) {
2351 l_cnt_map = cnt_map;
2352 continue;
2353 }
2354
2355 ret = -1;
2356 DBG_CALL(Dbg_dl_iphdr_unmap_ret(clml));
2357 goto done;
2358 }
2359 }
2360 }
2361
2362 done:
2363 if (entry)
2364 leave(LIST(clmp), 0);
2365 return (ret);
2366 }