xref: /titanic_51/usr/src/cmd/sgs/rtld/common/remove.c (revision 8edda6281c84e0632a22f9c8dbf0d6f1558878eb)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  *
21  *
22  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  *
25  * Remove objects.  Objects need removal from a process as part of:
26  *
27  *  o	a dlclose() request
28  *
29  *  o	tearing down a dlopen(), lazy-load, or filter hierarchy that failed to
30  *	completely load
31  *
32  * Any other failure condition will result in process exit (in which case all
33  * we have to do is execute the fini's - tear down is unnecessary).
34  *
35  * Any removal of objects is therefore associated with a dlopen() handle.  There
36  * is a small window between creation of the first dlopen() object and creating
37  * its handle (in which case remove_so() can get rid of the new link-map if
38  * necessary), but other than this all object removal is driven by inspecting
39  * the components of a handle.
40  *
41  * Things to note.  The creation of a link-map, and its addition to the link-map
42  * list occurs in {elf|aout}_new_lm(), if this returns success the link-map is
43  * valid and added, otherwise any steps (allocations) in the process of creating
44  * the link-map would have been undone.  If a failure occurs between creating
45  * the link-map and adding it to a handle, remove_so() is called to remove the
46  * link-map.  If a failures occurs after a handle have been created,
47  * remove_hdl() is called to remove the handle and the link-map.
48  */
49 #pragma ident	"%Z%%M%	%I%	%E% SMI"
50 
51 #include	"_synonyms.h"
52 
53 #include	<string.h>
54 #include	<stdio.h>
55 #include	<unistd.h>
56 #include	<dlfcn.h>
57 #include	<sys/debug.h>
58 #include	<sys/avl.h>
59 #include	<libc_int.h>
60 #include	<debug.h>
61 #include	"_rtld.h"
62 #include	"_audit.h"
63 #include	"_elf.h"
64 #include	"msg.h"
65 
66 /*
67  * Atexit callback provided by libc.  As part of dlclose() determine the address
68  * ranges of all objects that are to be deleted.  Pass this information to
69  * libc's pre-atexit routine.  Libc will purge any registered atexit() calls
70  * related to those objects about to be deleted.
71  */
72 static int
73 purge_exit_handlers(Lm_list *lml, Rt_map **tobj)
74 {
75 	uint_t			num;
76 	Rt_map			**_tobj;
77 	Lc_addr_range_t		*addr, *_addr;
78 	int			error;
79 	int			(*fptr)(Lc_addr_range_t *, uint_t);
80 
81 	/*
82 	 * Has a callback been established?
83 	 */
84 	if ((fptr = lml->lm_lcs[CI_ATEXIT].lc_un.lc_func) == NULL)
85 		return (0);
86 
87 	/*
88 	 * Determine the total number of mapped segments that will be unloaded.
89 	 */
90 	for (num = 0, _tobj = tobj; *_tobj != NULL; _tobj++) {
91 		Rt_map	*lmp = *_tobj;
92 
93 		num += MMAPCNT(lmp);
94 	}
95 
96 	/*
97 	 * Account for a null entry at the end of the address range array.
98 	 */
99 	if (num++ == 0)
100 		return (0);
101 
102 	/*
103 	 * Allocate an array for the address range.
104 	 */
105 	if ((addr = malloc(num * sizeof (Lc_addr_range_t))) == 0)
106 		return (1);
107 
108 	/*
109 	 * Fill the address range with each loadable segments size and address.
110 	 */
111 	for (_tobj = tobj, _addr = addr; *_tobj != NULL; _tobj++) {
112 		Rt_map	*lmp = *_tobj;
113 		Mmap	*mmaps;
114 
115 		for (mmaps = MMAPS(lmp); mmaps->m_vaddr; mmaps++) {
116 			_addr->lb = (void *)mmaps->m_vaddr;
117 			_addr->ub = (void *)(mmaps->m_vaddr + mmaps->m_msize);
118 			_addr++;
119 		}
120 	}
121 	_addr->lb = _addr->ub = 0;
122 
123 	leave(LIST(*tobj));
124 	error = (*fptr)(addr, (num - 1));
125 	(void) enter();
126 
127 	/*
128 	 * If we fail to converse with libc, generate an error message to
129 	 * satisfy any dlerror() usage.
130 	 */
131 	if (error)
132 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_ARG_ATEXIT), error);
133 
134 	free(addr);
135 	return (error);
136 }
137 
138 /*
139  * Remove any rejection message allocations.
140  */
141 void
142 remove_rej(Rej_desc *rej)
143 {
144 	if (rej && (rej->rej_type)) {
145 		if (rej->rej_name)
146 			free((void *)rej->rej_name);
147 		if (rej->rej_str && (rej->rej_str != MSG_ORIG(MSG_EMG_ENOMEM)))
148 			free((void *)rej->rej_str);
149 	}
150 }
151 
152 /*
153  * Break down a Pnode list.
154  */
155 void
156 remove_pnode(Pnode *pnp)
157 {
158 	Pnode	*opnp;
159 
160 	for (opnp = 0; pnp; opnp = pnp, pnp = pnp->p_next) {
161 		if (pnp->p_name)
162 			free((void *)pnp->p_name);
163 		if (pnp->p_oname)
164 			free((void *)pnp->p_oname);
165 		if (opnp)
166 			free((void *)opnp);
167 	}
168 	if (opnp)
169 		free((void *)opnp);
170 }
171 
172 
173 /*
174  * Remove a link-map list descriptor.  This is called to finalize the removal
175  * of an entire link-map list, after all link-maps have been removed, or none
176  * got added.  As load_one() can process a list of potential candidate objects,
177  * the link-map descriptor must be maintained as each object is processed.  Only
178  * after all objects have been processed can a failure condition finally tear
179  * down the link-map list descriptor.
180  */
181 void
182 remove_lml(Lm_list *lml)
183 {
184 	if (lml && (lml->lm_head == 0)) {
185 		/*
186 		 * As a whole link-map list is being removed, the debuggers
187 		 * would have been alerted of this deletion (or an addition
188 		 * in the case we're here to clean up from a failure).  Set
189 		 * the main link-map list so that a consistent registration
190 		 * can be signaled to the debuggers when we leave ld.so.1.
191 		 */
192 		lml_main.lm_flags |= LML_FLG_DBNOTIF;
193 
194 		if (lml->lm_lmidstr)
195 			free(lml->lm_lmidstr);
196 		if (lml->lm_alp)
197 			free(lml->lm_alp);
198 		if (lml->lm_lists)
199 			free(lml->lm_lists);
200 		if (lml->lm_actaudit)
201 			free(lml->lm_actaudit);
202 
203 		/*
204 		 * Cleanup any pending RTLDINFO in the case where it was
205 		 * allocated but not called (see _relocate_lmc()).
206 		 */
207 		if (lml->lm_rti)
208 			free(lml->lm_rti);
209 		if (lml->lm_fpavl) {
210 			/*
211 			 * As we are freeing the link-map list, all nodes must
212 			 * have previously been removed.
213 			 */
214 			ASSERT(avl_numnodes(lml->lm_fpavl) == 0);
215 			free(lml->lm_fpavl);
216 		}
217 		list_delete(&dynlm_list, lml);
218 		free(lml);
219 	}
220 }
221 
222 /*
223  * Remove a link-map.  This removes a link-map from its associated list and
224  * free's up the link-map itself.  Note, all components that are freed are local
225  * to the link-map, no inter-link-map lists are operated on as these are all
226  * broken down by dlclose() while all objects are still mapped.
227  *
228  * This routine is called from dlclose() to zap individual link-maps after their
229  * interdependencies (DEPENDS(), CALLER(), handles, etc.) have been removed.
230  * This routine is also called from the bowels of load_one() in the case of a
231  * link-map creation failure.
232  */
233 void
234 remove_so(Lm_list *lml, Rt_map *lmp)
235 {
236 	Dyninfo *dip;
237 
238 	if (lmp == 0)
239 		return;
240 
241 	/*
242 	 * Unlink the link map from the link-map list.
243 	 */
244 	if (lml && lmp)
245 		lm_delete(lml, lmp);
246 
247 	/*
248 	 * If this object contributed any local external vectors for the current
249 	 * link-map list, remove the vectors.  If this object contributed any
250 	 * global external vectors we should find some new candidates, or leave
251 	 * this object lying around.
252 	 */
253 	if (lml) {
254 		int	tag;
255 
256 		for (tag = 0; tag < CI_MAX; tag++) {
257 			if (lml->lm_lcs[tag].lc_lmp == lmp) {
258 				lml->lm_lcs[tag].lc_lmp = 0;
259 				lml->lm_lcs[tag].lc_un.lc_val = 0;
260 			}
261 			if (glcs[tag].lc_lmp == lmp) {
262 				ASSERT(glcs[tag].lc_lmp != 0);
263 				glcs[tag].lc_lmp = 0;
264 				glcs[tag].lc_un.lc_val = 0;
265 			}
266 		}
267 	}
268 
269 	DBG_CALL(Dbg_file_delete(lmp));
270 
271 	/*
272 	 * If this is a temporary link-map, put in place to facilitate the
273 	 * link-edit or a relocatable object, then the link-map contains no
274 	 * information that needs to be cleaned up.
275 	 */
276 	if (FLAGS(lmp) & FLG_RT_OBJECT)
277 		return;
278 
279 	/*
280 	 * Unmap the object.
281 	 */
282 	LM_UNMAP_SO(lmp)(lmp);
283 
284 	/*
285 	 * Remove any FullpathNode AVL names if they still exist.
286 	 */
287 	if (FPNODE(lmp))
288 		fpavl_remove(lmp);
289 
290 	/*
291 	 * Remove any alias names.
292 	 */
293 	if (ALIAS(lmp)) {
294 		Aliste	off;
295 		char	**cpp;
296 
297 		for (ALIST_TRAVERSE(ALIAS(lmp), off, cpp))
298 			free(*cpp);
299 		free(ALIAS(lmp));
300 	}
301 
302 	/*
303 	 * Remove any of this objects filtee infrastructure.  The filtees them-
304 	 * selves have already been removed.
305 	 */
306 	if (((dip = DYNINFO(lmp)) != 0) && (FLAGS1(lmp) & MSK_RT_FILTER)) {
307 		uint_t	cnt, max = DYNINFOCNT(lmp);
308 
309 		for (cnt = 0; cnt < max; cnt++, dip++) {
310 			if (dip->di_info && (dip->di_flags & MSK_DI_FILTER))
311 				remove_pnode((Pnode *)dip->di_info);
312 		}
313 	}
314 	if (dip)
315 		free(DYNINFO(lmp));
316 
317 	/*
318 	 * Deallocate any remaining cruft and free the link-map.
319 	 */
320 	if (RLIST(lmp))
321 		remove_pnode(RLIST(lmp));
322 
323 	if (REFNAME(lmp))
324 		free(REFNAME(lmp));
325 	if (ELFPRV(lmp))
326 		free(ELFPRV(lmp));
327 	if (AUDITORS(lmp))
328 		audit_desc_cleanup(lmp);
329 	if (AUDINFO(lmp))
330 		audit_info_cleanup(lmp);
331 
332 	if (CONDVAR(lmp))
333 		free(CONDVAR(lmp));
334 	if (COPY(lmp))
335 		free(COPY(lmp));
336 	if (MMAPS(lmp))
337 		free(MMAPS(lmp));
338 
339 	/*
340 	 * During a dlclose() any groups this object was a part of will have
341 	 * been torn down.  However, we can get here to remove an object that
342 	 * has failed to load, perhaps because its addition to a handle failed.
343 	 * Therefore if this object indicates that its part of a group tear
344 	 * these associations down.
345 	 */
346 	if (GROUPS(lmp)) {
347 		Aliste	off1;
348 		Grp_hdl	**ghpp;
349 
350 		for (ALIST_TRAVERSE(GROUPS(lmp), off1, ghpp)) {
351 			Grp_hdl		*ghp = *ghpp;
352 			Grp_desc	*gdp;
353 			Aliste		off2;
354 
355 			for (ALIST_TRAVERSE(ghp->gh_depends, off2, gdp)) {
356 				if (gdp->gd_depend != lmp)
357 					continue;
358 
359 				(void) alist_delete(ghp->gh_depends, 0, &off2);
360 				break;
361 			}
362 		}
363 		free(GROUPS(lmp));
364 	}
365 	if (HANDLES(lmp))
366 		free(HANDLES(lmp));
367 
368 	/*
369 	 * Clean up reglist if needed
370 	 */
371 	if (reglist != (Reglist *)0) {
372 		Reglist	*cur, *prv, *del;
373 
374 		cur = prv = reglist;
375 		while (cur != (Reglist *)0) {
376 			if (cur->rl_lmp == lmp) {
377 				del = cur;
378 				if (cur == reglist) {
379 					reglist = cur->rl_next;
380 					cur = prv = reglist;
381 				} else {
382 					prv->rl_next = cur->rl_next;
383 					cur = cur->rl_next;
384 				}
385 				free(del);
386 			} else {
387 				prv = cur;
388 				cur = cur->rl_next;
389 			}
390 		}
391 	}
392 
393 	/*
394 	 * Finally, free the various names, as these were duplicated so that
395 	 * they were available in core files.  This is left until last, to aid
396 	 * debugging previous elements of the removal process.
397 	 *
398 	 * The original name is set to the pathname by default (see fullpath()),
399 	 * but is overridden if the file is an alternative.  The pathname is set
400 	 * to the name by default (see [aout|elf]_new_lm()), but is overridden
401 	 * if the fullpath/resolve path differs (see fullpath()).  The original
402 	 * name is always duplicated, as it typically exists as a text string
403 	 * (see DT_NEEDED pointer) or was passed in from user code.
404 	 */
405 	if (ORIGNAME(lmp) != PATHNAME(lmp))
406 		free(ORIGNAME(lmp));
407 	if (PATHNAME(lmp) != NAME(lmp))
408 		free(PATHNAME(lmp));
409 	free(NAME(lmp));
410 
411 	free(lmp);
412 }
413 
414 
415 /*
416  * Traverse an objects dependency list removing callers and dependencies.
417  * There's a chicken and egg problem with tearing down link-maps.  Any
418  * relationship between link-maps is maintained on a DEPENDS, and associated
419  * CALLERS list.  These lists can't be broken down at the time a single link-
420  * map is removed as any related link-map may have already been removed.  Thus,
421  * lists between link-maps must be broken down before the individual link-maps
422  * themselves.
423  */
424 void
425 remove_lists(Rt_map *lmp, int lazy)
426 {
427 	Aliste		off1;
428 	Bnd_desc	**bdpp;
429 
430 	/*
431 	 * First, traverse this objects dependencies.
432 	 */
433 	for (ALIST_TRAVERSE(DEPENDS(lmp), off1, bdpp)) {
434 		Bnd_desc	*bdp = *bdpp;
435 		Rt_map		*dlmp = bdp->b_depend;
436 
437 		/*
438 		 * Remove this object from the dependencies callers.
439 		 */
440 		(void) alist_delete(CALLERS(dlmp), &bdp, 0);
441 		free(bdp);
442 	}
443 	if (DEPENDS(lmp)) {
444 		free(DEPENDS(lmp));
445 		DEPENDS(lmp) = 0;
446 	}
447 
448 	/*
449 	 * Second, traverse this objects callers.
450 	 */
451 	for (ALIST_TRAVERSE(CALLERS(lmp), off1,  bdpp)) {
452 		Bnd_desc	*bdp = *bdpp;
453 		Rt_map		*clmp = bdp->b_caller;
454 
455 		/*
456 		 * If we're removing an object that was triggered by a lazyload,
457 		 * remove the callers DYNINFO() entry and bump the lazy counts.
458 		 * This reinitialization of the lazy information allows a lazy
459 		 * object to be reloaded again later.  Although we may be
460 		 * breaking down a group of lazyloaded objects because one has
461 		 * failed to relocate, it's possible that one or more of the
462 		 * individual objects can be reloaded without a problem.
463 		 */
464 		if (lazy) {
465 			Dyninfo	*dip;
466 
467 			if ((dip = DYNINFO(clmp)) != 0) {
468 				uint_t	cnt, max = DYNINFOCNT(clmp);
469 
470 				for (cnt = 0; cnt < max; cnt++, dip++) {
471 					if ((dip->di_flags &
472 					    FLG_DI_NEEDED) == 0)
473 						continue;
474 
475 					if (dip->di_info == (void *)lmp) {
476 						dip->di_info = 0;
477 
478 						if (LAZY(clmp)++ == 0)
479 							LIST(clmp)->lm_lazy++;
480 					}
481 				}
482 			}
483 		}
484 
485 		(void) alist_delete(DEPENDS(clmp), &bdp, 0);
486 		free(bdp);
487 	}
488 	if (CALLERS(lmp)) {
489 		free(CALLERS(lmp));
490 		CALLERS(lmp) = 0;
491 	}
492 }
493 
494 /*
495  * Delete any temporary link-map control list.
496  */
497 void
498 remove_cntl(Lm_list *lml, Aliste lmco)
499 {
500 	if (lmco && (lmco != ALO_DATA)) {
501 		Aliste	_lmco = lmco;
502 #if	DEBUG
503 		Lm_cntl	*lmc = (Lm_cntl *)((char *)lml->lm_lists + lmco);
504 
505 		/*
506 		 * This element should be empty.
507 		 */
508 		ASSERT(lmc->lc_head == 0);
509 #endif
510 		(void) alist_delete(lml->lm_lists, 0, &_lmco);
511 	}
512 }
513 
514 /*
515  * If a lazy loaded object, or filtee fails to load, possibly because it, or
516  * one of its dependencies can't be relocated, then tear down any objects
517  * that are apart of this link-map control list.
518  */
519 void
520 remove_incomplete(Lm_list *lml, Aliste lmco)
521 {
522 	Rt_map	*lmp;
523 	Lm_cntl	*lmc;
524 
525 	/* LINTED */
526 	lmc = (Lm_cntl *)((char *)lml->lm_lists + lmco);
527 
528 	/*
529 	 * First, remove any lists that may point between objects.
530 	 */
531 	for (lmp = lmc->lc_head; lmp; lmp = (Rt_map *)NEXT(lmp))
532 		remove_lists(lmp, 1);
533 
534 	/*
535 	 * Finally, remove each object.  remove_so() calls lm_delete(), thus
536 	 * effectively the link-map control head gets updated to point to the
537 	 * next link-map.
538 	 */
539 	while ((lmp = lmc->lc_head) != 0)
540 		remove_so(lml, lmp);
541 
542 	lmc->lc_head = lmc->lc_tail = 0;
543 }
544 
545 /*
546  * Determine whether an object is deletable.
547  */
548 int
549 is_deletable(Alist **lmalp, Alist **ghalp, Rt_map *lmp)
550 {
551 	Aliste		off;
552 	Bnd_desc	**bdpp;
553 	Grp_hdl		**ghpp;
554 
555 	/*
556 	 * If the object hasn't yet been relocated take this as a sign that
557 	 * it's loading failed, thus we're here to cleanup.  If the object is
558 	 * relocated it will only be retained if it was marked non-deletable,
559 	 * and exists on the main link-map control list.
560 	 */
561 	if ((FLAGS(lmp) & FLG_RT_RELOCED) &&
562 	    (MODE(lmp) & RTLD_NODELETE) && (CNTL(lmp) == ALO_DATA))
563 		return (0);
564 
565 	/*
566 	 * If this object is the head of a handle that has not been captured as
567 	 * a candidate for deletion, then this object is in use from a dlopen()
568 	 * outside of the scope of this dlclose() family.  Dlopen'ed objects,
569 	 * and filtees, have group descriptors for their callers.  Typically
570 	 * this parent will have callers that are not apart of this dlclose()
571 	 * family, and thus would be caught by the CALLERS test below.  However,
572 	 * if the caller had itself been dlopen'ed, it may not have any explicit
573 	 * callers registered for itself.  Thus, but looking for objects with
574 	 * handles we can ferret out these outsiders.
575 	 */
576 	for (ALIST_TRAVERSE(HANDLES(lmp), off, ghpp)) {
577 		if (alist_test(ghalp, *ghpp,
578 		    sizeof (Grp_hdl *), 0) != ALE_EXISTS)
579 			return (0);
580 	}
581 
582 	/*
583 	 * If this object is called by any object outside of the family of
584 	 * objects selected for deletion, it can't be deleted.
585 	 */
586 	for (ALIST_TRAVERSE(CALLERS(lmp), off, bdpp)) {
587 		if (alist_test(lmalp, (*bdpp)->b_caller,
588 		    sizeof (Rt_map *), 0) != ALE_EXISTS)
589 			return (0);
590 	}
591 
592 	/*
593 	 * This object is a candidate for deletion.
594 	 */
595 	return (1);
596 }
597 
598 /*
599  * Collect the groups (handles) and associated objects that are candidates for
600  * deletion.  The criteria for deleting an object is whether it is only refer-
601  * enced from the objects within the groups that are candidates for deletion.
602  */
603 static int
604 gdp_collect(Alist **ghalpp, Alist **lmalpp, Grp_hdl *ghp1)
605 {
606 	Aliste		off;
607 	Grp_desc	*gdp;
608 	int		action;
609 
610 	/*
611 	 * Add this group to our group collection.  If it isn't added either an
612 	 * allocation has failed, or it already exists.
613 	 */
614 	if ((action = alist_test(ghalpp, ghp1, sizeof (Grp_hdl *),
615 	    AL_CNT_GRPCLCT)) != ALE_CREATE)
616 		return (action);
617 
618 	/*
619 	 * Traverse the dependencies of the group and collect the associated
620 	 * objects.
621 	 */
622 	for (ALIST_TRAVERSE(ghp1->gh_depends, off, gdp)) {
623 		Rt_map	*lmp = gdp->gd_depend;
624 
625 		/*
626 		 * We only want to process dependencies for deletion.  Although
627 		 * we want to purge group descriptors for parents, we don't want
628 		 * to analyze the parent itself for additional filters or
629 		 * deletion.
630 		 */
631 		if ((gdp->gd_flags & GPD_ADDEPS) == 0)
632 			continue;
633 
634 		if ((action = alist_test(lmalpp, lmp, sizeof (Rt_map *),
635 		    AL_CNT_GRPCLCT)) == 0)
636 			return (0);
637 		if (action == ALE_EXISTS)
638 			continue;
639 
640 		/*
641 		 * If this object hasn't yet been relocated take this as a sign
642 		 * that it's loading failed, thus we're here to cleanup.  Or,
643 		 * if this object isn't obviously non-deletable, determine
644 		 * whether it provides any filtees.  Add these groups to the
645 		 * group collection.
646 		 */
647 		if ((((FLAGS(lmp) & FLG_RT_RELOCED) == 0) ||
648 		    ((MODE(lmp) & RTLD_NODELETE) == 0)) &&
649 		    (FLAGS1(lmp) & MSK_RT_FILTER)) {
650 			Dyninfo	*dip = DYNINFO(lmp);
651 			uint_t	cnt, max = DYNINFOCNT(lmp);
652 
653 			for (cnt = 0; cnt < max; cnt++, dip++) {
654 				Pnode	*pnp;
655 
656 				if ((dip->di_info == 0) ||
657 				    ((dip->di_flags & MSK_DI_FILTER) == 0))
658 					continue;
659 
660 				for (pnp = (Pnode *)dip->di_info; pnp;
661 				    pnp = pnp->p_next) {
662 					Grp_hdl	*ghp2;
663 
664 					if ((pnp->p_len == 0) || ((ghp2 =
665 					    (Grp_hdl *)pnp->p_info) == 0))
666 						continue;
667 
668 					if (gdp_collect(ghalpp, lmalpp,
669 					    ghp2) == 0)
670 						return (0);
671 				}
672 			}
673 		}
674 	}
675 	return (1);
676 }
677 
678 /*
679  * Traverse the list of deletable candidates.  If an object can't be deleted
680  * then neither can its dependencies or filtees.  Any object that is cleared
681  * from being deleted drops the deletion count, plus, if there are no longer
682  * any deletions pending we can discontinue any further processing.
683  */
684 static int
685 remove_rescan(Alist *lmalp, Alist *ghalp, int *delcnt)
686 {
687 	Aliste		off1;
688 	Rt_map		**lmpp;
689 	int		rescan = 0;
690 
691 	for (ALIST_TRAVERSE(lmalp, off1, lmpp)) {
692 		Aliste		off2;
693 		Bnd_desc	**bdpp;
694 		Rt_map		*lmp = *lmpp;
695 		Dyninfo		*dip;
696 		uint_t		cnt, max;
697 
698 		if (FLAGS(lmp) & FLG_RT_DELETE)
699 			continue;
700 
701 		/*
702 		 * As this object can't be deleted, make sure its dependencies
703 		 * aren't deleted either.
704 		 */
705 		for (ALIST_TRAVERSE(DEPENDS(lmp), off2, bdpp)) {
706 			Rt_map	*dlmp = (*bdpp)->b_depend;
707 
708 			if (FLAGS(dlmp) & FLG_RT_DELETE) {
709 				FLAGS(dlmp) &= ~FLG_RT_DELETE;
710 				if (--(*delcnt) == 0)
711 					return (0);
712 				rescan = 1;
713 			}
714 		}
715 
716 		/*
717 		 * If this object is a filtee and one of its filters is outside
718 		 * of this dlclose family, then it can't be deleted either.
719 		 */
720 		if ((FLAGS1(lmp) & MSK_RT_FILTER) == 0)
721 			continue;
722 
723 		dip = DYNINFO(lmp);
724 		max = DYNINFOCNT(lmp);
725 
726 		for (cnt = 0; cnt < max; cnt++, dip++) {
727 			Pnode	*pnp;
728 
729 			if ((dip->di_info == 0) ||
730 			    ((dip->di_flags & MSK_DI_FILTER) == 0))
731 				continue;
732 
733 			for (pnp = (Pnode *)dip->di_info; pnp;
734 			    pnp = pnp->p_next) {
735 				Grp_hdl		*ghp;
736 				Grp_desc	*gdp;
737 
738 				if ((pnp->p_len == 0) ||
739 				    ((ghp = (Grp_hdl *)pnp->p_info) == 0))
740 					continue;
741 
742 				if (alist_test(&ghalp, ghp,
743 				    sizeof (Grp_hdl *), 0) == ALE_EXISTS)
744 					continue;
745 
746 				for (ALIST_TRAVERSE(ghp->gh_depends, off2,
747 				    gdp)) {
748 					Rt_map	*dlmp = gdp->gd_depend;
749 
750 					if (FLAGS(dlmp) & FLG_RT_DELETE) {
751 						FLAGS(dlmp) &= ~FLG_RT_DELETE;
752 						if (--(*delcnt) == 0)
753 							return (0);
754 						rescan = 1;
755 					}
756 				}
757 
758 				/*
759 				 * Remove this group handle from our dynamic
760 				 * deletion list.
761 				 */
762 				(void) alist_delete(ghalp, &ghp, 0);
763 			}
764 		}
765 	}
766 	return (rescan);
767 }
768 
769 /*
770  * Cleanup any collection alists we've created.
771  */
772 static void
773 remove_collect(Alist *ghalp, Alist *lmalp)
774 {
775 	if (ghalp)
776 		free(ghalp);
777 	if (lmalp)
778 		free(lmalp);
779 }
780 
781 /*
782  * Remove a handle, leaving the associated objects intact.  Besides the classic
783  * dlopen() usage, handles are used as a means of associating a group of objects
784  * and promoting modes.  Once object promotion is completed, the handle should
785  * be discarded while leaving the associated objects intact.  Leaving the handle
786  * would prevent the object from being deleted (as it looks like it's in use
787  * by another user).
788  */
789 void
790 free_hdl(Grp_hdl *ghp)
791 {
792 	if (--(ghp->gh_refcnt) == 0) {
793 		Grp_desc	*gdp;
794 		uintptr_t	ndx;
795 		Aliste		off;
796 
797 		for (ALIST_TRAVERSE(ghp->gh_depends, off, gdp)) {
798 			Rt_map	*lmp = gdp->gd_depend;
799 
800 			if (ghp->gh_ownlmp == lmp)
801 				(void) alist_delete(HANDLES(lmp), &ghp, 0);
802 			(void) alist_delete(GROUPS(lmp), &ghp, 0);
803 		}
804 		(void) free(ghp->gh_depends);
805 
806 		/* LINTED */
807 		ndx = (uintptr_t)ghp % HDLIST_SZ;
808 		list_delete(&hdl_list[ndx], ghp);
809 
810 		(void) free(ghp);
811 	}
812 }
813 
814 /*
815  * If a load operation, using a new link-map control list, has failed, then
816  * forcibly remove the failed objects.  This failure can occur as a result
817  * of a lazy load, a dlopen(), or a filtee load, once the application is
818  * running.  If the link-map control list has not yet started relocation, then
819  * cleanup is simply a process of removing all the objects from the control
820  * list.  If relocation has begun, then other loads may have been triggered to
821  * satisfy the relocations, and thus we need to break down the control list
822  * using handles.
823  *
824  * The objects associated with this load must be part of a unique handle.  In
825  * the case of a dlopen() or filtee request, a handle will have been created.
826  * For a lazyload request, a handle must be generated so that the remove
827  * process can use the handle.
828  *
829  * During the course of processing these objects, other objects (handles) may
830  * have been loaded to satisfy relocation requirements.  After these families
831  * have successfully loaded, they will have been propagated to the same link-map
832  * control list.  The failed objects need to be removed from this list, while
833  * any successfully loaded families can be left alone, and propagated to the
834  * previous link-map control list.  By associating each load request with a
835  * handle, we can isolate the failed objects while not interfering with any
836  * successfully loaded families.
837  */
838 void
839 remove_lmc(Lm_list *lml, Rt_map *clmp, Lm_cntl *lmc, Aliste lmco,
840     const char *name)
841 {
842 	Grp_hdl		*ghp;
843 	Grp_desc	*gdp;
844 	Aliste		off;
845 	Rt_map		*lmp;
846 
847 	DBG_CALL(Dbg_file_cleanup(lml, name, lmco));
848 
849 	/*
850 	 * Obtain a handle for the first object on the link-map control list.
851 	 * If none exists (which would occur from a lazy load request), and
852 	 * the link-map control list is being relocated, create a handle.
853 	 */
854 	lmp = lmc->lc_head;
855 	if (HANDLES(lmp)) {
856 		ghp = (Grp_hdl *)HANDLES(lmp)->al_data[0];
857 
858 	} else if (lmc->lc_flags & LMC_FLG_RELOCATING) {
859 		/*
860 		 * Establish a handle, and should anything fail, fall through
861 		 * to remove the link-map control list.
862 		 */
863 		if (((ghp = hdl_create(lml, lmc->lc_head, 0, 0)) == 0) ||
864 		    (hdl_initialize(ghp, lmc->lc_head, 0, 0) == 0))
865 			lmc->lc_flags &= ~LMC_FLG_RELOCATING;
866 	} else {
867 		ghp = 0;
868 	}
869 
870 	/*
871 	 * If relocation hasn't begun, simply remove all the objects from this
872 	 * list, and any handle that may have been created.
873 	 */
874 	if ((lmc->lc_flags & LMC_FLG_RELOCATING) == 0) {
875 		remove_incomplete(lml, lmco);
876 
877 		if (ghp) {
878 			ghp->gh_refcnt = 1;
879 			free_hdl(ghp);
880 		}
881 		return;
882 	}
883 
884 	ASSERT(ghp != 0);
885 
886 	/*
887 	 * As the objects of this handle are being forcibly removed, first
888 	 * remove any associations to objects on parent link-map control
889 	 * lists.  This breaks the bond between a caller and a hierarchy of
890 	 * dependencies represented by the handle, thus the caller doesn't lock
891 	 * the hierarchy and prevent their deletion from the generic handle
892 	 * processing or remove_hdl().
893 	 *
894 	 * This scenario can be produced when the relocation of a object
895 	 * results in vectoring through a filter that is already loaded.  The
896 	 * filtee may be on the link-map list that is presently being processed,
897 	 * however an association between the filter and filtee would have been
898 	 * established during filtee processing.  It is this association that
899 	 * must be broken to allow the objects on this link-map list to be
900 	 * removed.
901 	 */
902 	for (ALIST_TRAVERSE(ghp->gh_depends, off, gdp)) {
903 		Rt_map	*lmp = gdp->gd_depend;
904 
905 		/*
906 		 * If this object has not been relocated, break down any
907 		 * dependency relationships the object might have established.
908 		 */
909 		if ((FLAGS(lmp) & FLG_RT_RELOCED) == 0)
910 			remove_lists(lmp, 1);
911 
912 		if (CNTL(lmp) == lmco)
913 			continue;
914 
915 		if (gdp->gd_flags & GPD_FILTER) {
916 			Dyninfo	*dip = DYNINFO(lmp);
917 			uint_t	cnt, max = DYNINFOCNT(lmp);
918 
919 			for (cnt = 0; cnt < max; cnt++, dip++) {
920 				Pnode	*pnp;
921 
922 				if ((dip->di_info == 0) ||
923 				    ((dip->di_flags & MSK_DI_FILTER) == 0))
924 					continue;
925 
926 				for (pnp = (Pnode *)dip->di_info; pnp;
927 				    pnp = pnp->p_next) {
928 					if ((Grp_hdl *)pnp->p_info == ghp) {
929 						pnp->p_info = 0;
930 						break;
931 					}
932 				}
933 			}
934 		}
935 		(void) alist_delete(GROUPS(lmp), &ghp, 0);
936 		(void) alist_delete(ghp->gh_depends, 0, &off);
937 	}
938 
939 	/*
940 	 * Having removed any callers, set the group handle reference count to
941 	 * one, and let the generic handle remover delete the associated
942 	 * objects.
943 	 */
944 	ghp->gh_refcnt = 1;
945 	(void) remove_hdl(ghp, clmp, 0);
946 
947 	/*
948 	 * If this link-map control list still contains objects, determine the
949 	 * previous control list and move the objects.
950 	 */
951 	if (lmc->lc_head) {
952 		Lm_cntl *plmc;
953 		Aliste  plmco;
954 
955 		plmco = lmco - lml->lm_lists->al_size;
956 		/* LINTED */
957 		plmc = (Lm_cntl *)((char *)lml->lm_lists + plmco);
958 
959 		lm_move(lml, lmco, plmco, lmc, plmc);
960 	}
961 }
962 
963 /*
964  * Remove the objects associated with a handle.  There are two goals here, to
965  * delete the objects associated with the handle, and to remove the handle
966  * itself.  Things get a little more complex if the objects selected for
967  * deletion are filters, in this case we also need to collect their filtees,
968  * and process the combined groups as a whole.  But, care still must be exer-
969  * cised to make sure any filtees found aren't being used by filters outside of
970  * the groups we've collect.  The series of events is basically:
971  *
972  *  o	Determine the groups (handles) that might be deletable.
973  *
974  *  o	Determine the objects of these handles that can be deleted.
975  *
976  *  o	Fire the fini's of those objects selected for deletion.
977  *
978  *  o	Remove all inter-dependency linked lists while the objects link-maps
979  *	are still available.
980  *
981  *  o	Remove all deletable objects link-maps and unmap the objects themselves.
982  *
983  *  o	Remove the handle descriptors for each deleted object, and hopefully
984  *	the whole handle.
985  *
986  * An handle that can't be deleted is added to an orphans list.  This list is
987  * revisited any time another dlclose() request results in handle descriptors
988  * being deleted.  These deleted descriptors can be sufficient to allow the
989  * final deletion of the orphaned handles.
990  */
991 int
992 remove_hdl(Grp_hdl *ghp, Rt_map *clmp, int *removed)
993 {
994 	Rt_map		*lmp, **lmpp;
995 	int		rescan = 0;
996 	int		delcnt = 0, rmcnt = 0, error = 0, orphans;
997 	Alist		*lmalp = 0, *ghalp = 0;
998 	Aliste		off1, off2;
999 	Grp_hdl		**ghpp;
1000 	Grp_desc	*gdp;
1001 	Lm_list		*lml = 0;
1002 
1003 	/*
1004 	 * Generate the family of groups and objects that are candidates for
1005 	 * deletion.  This consists of the objects that are explicitly defined
1006 	 * as dependencies of this handle, plus any filtee handles and their
1007 	 * associated objects.
1008 	 */
1009 	if (gdp_collect(&ghalp, &lmalp, ghp) == 0) {
1010 		remove_collect(ghalp, lmalp);
1011 		return (0);
1012 	}
1013 
1014 	DBG_CALL(Dbg_file_hdl_title(DBG_DEP_DELETE));
1015 
1016 	/*
1017 	 * Traverse the groups we've collected to determine if any filtees are
1018 	 * included.  If so, and the filtee handle is in use by a filter outside
1019 	 * of the family of objects collected for this deletion, it can not be
1020 	 * removed.
1021 	 */
1022 	for (ALIST_TRAVERSE(ghalp, off1, ghpp)) {
1023 		Grp_hdl	*ghp = *ghpp;
1024 
1025 		DBG_CALL(Dbg_file_hdl_collect(ghp, 0));
1026 
1027 		if ((ghp->gh_flags & GPH_FILTEE) == 0)
1028 			continue;
1029 
1030 		/*
1031 		 * Special case for ld.so.1.  There can be multiple instances of
1032 		 * libdl.so.1 using this handle, so although we want the handles
1033 		 * reference count to be decremented, we don't want the handle
1034 		 * removed.
1035 		 */
1036 		if (ghp->gh_flags & GPH_LDSO) {
1037 			DBG_CALL(Dbg_file_hdl_collect(ghp,
1038 			    NAME(lml_rtld.lm_head)));
1039 			(void) alist_delete(ghalp, 0, &off1);
1040 			continue;
1041 		}
1042 
1043 		for (ALIST_TRAVERSE(ghp->gh_depends, off2, gdp)) {
1044 			Grp_hdl	**ghpp3;
1045 			Aliste	off3;
1046 
1047 			/*
1048 			 * Determine whether this dependency is the filtee's
1049 			 * parent filter, and that it isn't also an explicit
1050 			 * dependency (in which case it would have added its own
1051 			 * dependencies to the handle).
1052 			 */
1053 			if ((gdp->gd_flags &
1054 			    (GPD_FILTER | GPD_ADDEPS)) != GPD_FILTER)
1055 				continue;
1056 
1057 			if (alist_test(&lmalp, gdp->gd_depend,
1058 			    sizeof (Rt_map *), 0) == ALE_EXISTS)
1059 				continue;
1060 
1061 			/*
1062 			 * Remove this group handle from our dynamic deletion
1063 			 * list.  In addition, recompute the list of objects
1064 			 * that are candidates for deletion to continue this
1065 			 * group verification.
1066 			 */
1067 			DBG_CALL(Dbg_file_hdl_collect(ghp,
1068 			    NAME(gdp->gd_depend)));
1069 			(void) alist_delete(ghalp, 0, &off1);
1070 
1071 			free(lmalp);
1072 			lmalp = 0;
1073 			for (ALIST_TRAVERSE(ghalp, off3, ghpp3)) {
1074 				Aliste		off4;
1075 				Grp_desc	*gdp4;
1076 
1077 				for (ALIST_TRAVERSE((*ghpp3)->gh_depends,
1078 				    off4, gdp4))  {
1079 					if ((gdp4->gd_flags & GPD_ADDEPS) == 0)
1080 						continue;
1081 					if (alist_test(&lmalp, gdp4->gd_depend,
1082 					    sizeof (Rt_map *),
1083 					    AL_CNT_GRPCLCT) == 0) {
1084 						remove_collect(ghalp, lmalp);
1085 						return (0);
1086 					}
1087 				}
1088 			}
1089 			break;
1090 		}
1091 	}
1092 
1093 	/*
1094 	 * Now that we've collected all the handles dependencies, traverse the
1095 	 * collection determining whether they are a candidate for deletion.
1096 	 */
1097 	for (ALIST_TRAVERSE(lmalp, off1, lmpp)) {
1098 		lmp = *lmpp;
1099 
1100 		/*
1101 		 * Establish which link-map list we're dealing with for later
1102 		 * .fini processing.
1103 		 */
1104 		if (lml == 0)
1105 			lml = LIST(lmp);
1106 
1107 		/*
1108 		 * If an object isn't a candidate for deletion we'll have to
1109 		 * rescan the handle insuring that this objects dependencies
1110 		 * aren't deleted either.
1111 		 */
1112 		if (is_deletable(&lmalp, &ghalp, lmp)) {
1113 			FLAGS(lmp) |= FLG_RT_DELETE;
1114 			delcnt++;
1115 		} else
1116 			rescan = 1;
1117 	}
1118 
1119 	/*
1120 	 * Rescan the handle if any objects where found non-deletable.
1121 	 */
1122 	while (rescan)
1123 		rescan = remove_rescan(lmalp, ghalp, &delcnt);
1124 
1125 	/*
1126 	 * Now that we have determined the number of groups that are candidates
1127 	 * for removal, mark each group descriptor as a candidate for removal
1128 	 * from the group.
1129 	 */
1130 	for (ALIST_TRAVERSE(ghalp, off1, ghpp)) {
1131 		for (ALIST_TRAVERSE((*ghpp)->gh_depends, off2, gdp))
1132 			gdp->gd_flags |= GPD_REMOVE;
1133 	}
1134 
1135 	/*
1136 	 * Now that we know which objects on this handle can't be deleted
1137 	 * determine whether they still need to remain identified as belonging
1138 	 * to this group to be able to continue binding to one another.
1139 	 */
1140 	for (ALIST_TRAVERSE(ghalp, off1, ghpp)) {
1141 		Grp_hdl	*ghp = *ghpp;
1142 
1143 		for (ALIST_TRAVERSE(ghp->gh_depends, off2, gdp)) {
1144 			Aliste		off3;
1145 			Bnd_desc	**bdpp;
1146 
1147 			lmp = gdp->gd_depend;
1148 
1149 			if (FLAGS(lmp) & FLG_RT_DELETE)
1150 				continue;
1151 
1152 			for (ALIST_TRAVERSE(DEPENDS(lmp), off3, bdpp)) {
1153 				Aliste 		off4;
1154 				Grp_desc	*gdp4;
1155 				Rt_map		*dlmp = (*bdpp)->b_depend;
1156 
1157 				/*
1158 				 * If this dependency (dlmp) can be referenced
1159 				 * by the caller (clmp) without being part of
1160 				 * this group (ghp) then belonging to this group
1161 				 * is no longer necessary.  This can occur when
1162 				 * objects are part of multiple handles, or if a
1163 				 * previously deleted handle was moved to the
1164 				 * orphan list and has been reopened.  Note,
1165 				 * first make sure the caller can reference the
1166 				 * dependency with this group, if it can't we
1167 				 * must be bound to a filtee, so there's no need
1168 				 * to remain a part of this group either.
1169 				 */
1170 				if ((callable(lmp, dlmp, 0) == 0) ||
1171 				    callable(lmp, dlmp, ghp))
1172 					continue;
1173 
1174 				if (gdp->gd_flags & GPD_REMOVE)
1175 					gdp->gd_flags &= ~GPD_REMOVE;
1176 
1177 				for (ALIST_TRAVERSE(ghp->gh_depends,
1178 				    off4, gdp4)) {
1179 					if (gdp4->gd_depend != dlmp)
1180 						continue;
1181 
1182 					if (gdp4->gd_flags & GPD_REMOVE)
1183 						gdp4->gd_flags &= ~GPD_REMOVE;
1184 				}
1185 			}
1186 		}
1187 	}
1188 
1189 	/*
1190 	 * If the owner of a handle can't be deleted and it's handle descriptor
1191 	 * must remain also, don't delete the handle at all.  Leave it for
1192 	 * possible later use.  Although it's left intact, it will still be
1193 	 * moved to the orphans list, as we might be able to revisit it on later
1194 	 * dlclose() operations and finally remove the underlying objects.  Note
1195 	 * that the handle still remains attached to the owner via the HANDLES
1196 	 * list, so that it can be re-associated to the owner if a dlopen()
1197 	 * of this object reoccurs.
1198 	 */
1199 	for (ALIST_TRAVERSE(ghalp, off1, ghpp)) {
1200 		Grp_hdl	*ghp = *ghpp;
1201 
1202 		/*
1203 		 * If this handle is already an orphan, or if it's owner is
1204 		 * deletable there's no need to inspect its dependencies.
1205 		 */
1206 		if ((ghp->gh_ownlmp == 0) ||
1207 		    (FLAGS(ghp->gh_ownlmp) & FLG_RT_DELETE))
1208 			continue;
1209 
1210 		/*
1211 		 * Make sure all handle dependencies aren't removed or the
1212 		 * dependencies themselves aren't deleted.
1213 		 */
1214 		for (ALIST_TRAVERSE(ghp->gh_depends, off2, gdp)) {
1215 			lmp = gdp->gd_depend;
1216 
1217 			/*
1218 			 * The first dependency of a non-orphaned handle is the
1219 			 * owner.  If the handle descriptor for this isn't
1220 			 * required there's no need to look at any other of the
1221 			 * handles dependencies.
1222 			 */
1223 			if ((lmp == ghp->gh_ownlmp) &&
1224 			    (gdp->gd_flags & GPD_REMOVE))
1225 				break;
1226 
1227 			if (gdp->gd_flags & GPD_REMOVE)
1228 				gdp->gd_flags &= ~GPD_REMOVE;
1229 			if (FLAGS(lmp) & FLG_RT_DELETE) {
1230 				FLAGS(lmp) &= ~FLG_RT_DELETE;
1231 				delcnt--;
1232 			}
1233 		}
1234 	}
1235 
1236 	/*
1237 	 * Final scan of objects to see if any objects are to to be deleted.
1238 	 * Also - display diagnostic information on what operations are to be
1239 	 * performed on the collected handles before firing .fini's (which
1240 	 * produces additional diagnostics).
1241 	 */
1242 	for (ALIST_TRAVERSE(ghalp, off1, ghpp)) {
1243 		Grp_hdl	*ghp = *ghpp;
1244 
1245 		DBG_CALL(Dbg_file_hdl_title(DBG_DEP_DELETE));
1246 
1247 		for (ALIST_TRAVERSE(ghp->gh_depends, off2, gdp)) {
1248 			int	flag;
1249 
1250 			lmp = gdp->gd_depend;
1251 
1252 			if (FLAGS(lmp) & FLG_RT_DELETE) {
1253 				flag = DBG_DEP_DELETE;
1254 
1255 				/*
1256 				 * Remove any pathnames from the FullpathNode
1257 				 * AVL tree.  As we're about to fire .fini's,
1258 				 * it's possible this object will be required
1259 				 * again, in which case we want to make sure a
1260 				 * new version of the object gets loaded.
1261 				 */
1262 				if (FPNODE(lmp))
1263 					fpavl_remove(lmp);
1264 			} else if (gdp->gd_flags & GPD_REMOVE)
1265 				flag = DBG_DEP_REMOVE;
1266 			else
1267 				flag = DBG_DEP_REMAIN;
1268 
1269 			DBG_CALL(Dbg_file_hdl_action(ghp, lmp, flag, 0));
1270 		}
1271 	}
1272 
1273 	/*
1274 	 * If there are objects to be deleted process their .fini's.
1275 	 */
1276 	if (delcnt) {
1277 		Rt_map	**tobj;
1278 
1279 		/*
1280 		 * If we're being audited tell the audit library that we're
1281 		 * about to go deleting dependencies.
1282 		 */
1283 		if (clmp && ((LIST(clmp)->lm_tflags | FLAGS1(clmp)) &
1284 		    LML_TFLG_AUD_ACTIVITY))
1285 			audit_activity(clmp, LA_ACT_DELETE);
1286 
1287 		/*
1288 		 * Sort and fire all fini's of the objects selected for
1289 		 * deletion.  Note that we have to start our search from the
1290 		 * link-map head - there's no telling whether this object has
1291 		 * dependencies on objects that were loaded before it and which
1292 		 * can now be deleted.  If the tsort() fails because of an
1293 		 * allocation error then that might just be a symptom of why
1294 		 * we're here in the first place - forgo the fini's but
1295 		 * continue to try cleaning up.
1296 		 */
1297 		lml->lm_flags |= LML_FLG_OBJDELETED;
1298 
1299 		if (((tobj = tsort(lml->lm_head, delcnt,
1300 		    (RT_SORT_DELETE | RT_SORT_FWD))) != 0) &&
1301 		    (tobj != (Rt_map **)S_ERROR)) {
1302 			error = purge_exit_handlers(lml, tobj);
1303 			call_fini(lml, tobj);
1304 		}
1305 
1306 		/*
1307 		 * Audit the closure of the dlopen'ed object to any local
1308 		 * auditors.  Any global auditors would have been caught by
1309 		 * call_fini(), but as the link-maps CALLERS was removed
1310 		 * already we do the local auditors explicitly.
1311 		 */
1312 		for (ALIST_TRAVERSE(ghalp, off1, ghpp)) {
1313 			Grp_hdl	*ghp = *ghpp;
1314 			Rt_map	*dlmp = ghp->gh_ownlmp;
1315 
1316 			if (clmp && dlmp &&
1317 			    ((LIST(dlmp)->lm_flags & LML_FLG_NOAUDIT) == 0) &&
1318 			    (FLAGS1(clmp) & LML_TFLG_AUD_OBJCLOSE))
1319 				_audit_objclose(&(AUDITORS(clmp)->ad_list),
1320 				    dlmp);
1321 		}
1322 	}
1323 
1324 	/*
1325 	 * Now that .fini processing (which may have involved new bindings)
1326 	 * is complete, remove all inter-dependency lists from those objects
1327 	 * selected for deletion.
1328 	 */
1329 	for (ALIST_TRAVERSE(lmalp, off1, lmpp)) {
1330 		Dyninfo	*dip;
1331 		uint_t	cnt, max;
1332 
1333 		lmp = *lmpp;
1334 
1335 		if (FLAGS(lmp) & FLG_RT_DELETE)
1336 			remove_lists(lmp, 0);
1337 
1338 		/*
1339 		 * Determine whether we're dealing with a filter, and if so
1340 		 * process any inter-dependencies with its filtee's.
1341 		 */
1342 		if ((FLAGS1(lmp) & MSK_RT_FILTER) == 0)
1343 			continue;
1344 
1345 		dip = DYNINFO(lmp);
1346 		max = DYNINFOCNT(lmp);
1347 
1348 		for (cnt = 0; cnt < max; cnt++, dip++) {
1349 			Pnode	*pnp;
1350 
1351 			if ((dip->di_info == 0) ||
1352 			    ((dip->di_flags & MSK_DI_FILTER) == 0))
1353 				continue;
1354 
1355 			for (pnp = (Pnode *)dip->di_info; pnp;
1356 			    pnp = pnp->p_next) {
1357 				Grp_hdl	*ghp;
1358 
1359 				if ((pnp->p_len == 0) ||
1360 				    ((ghp = (Grp_hdl *)pnp->p_info) == 0))
1361 					continue;
1362 
1363 				/*
1364 				 * Determine whether this filtee's handle is a
1365 				 * part of the list of handles being deleted.
1366 				 */
1367 				if (alist_test(&ghalp, ghp,
1368 				    sizeof (Grp_hdl *), 0) == ALE_EXISTS) {
1369 					/*
1370 					 * If this handle exists on the deletion
1371 					 * list, then it has been removed.  If
1372 					 * this filter isn't going to be
1373 					 * deleted, sever its reference to the
1374 					 * handle.
1375 					 */
1376 					pnp->p_info = 0;
1377 				} else {
1378 					/*
1379 					 * If this handle isn't on the deletion
1380 					 * list, then it must still exist.  If
1381 					 * this filter is being deleted, make
1382 					 * sure the filtees reference count
1383 					 * gets decremented.
1384 					 */
1385 					if (FLAGS(lmp) & FLG_RT_DELETE) {
1386 						(void) dlclose_core(ghp,
1387 						    lmp, lml);
1388 					}
1389 				}
1390 			}
1391 		}
1392 	}
1393 
1394 	/*
1395 	 * If called from dlclose(), determine if there are already handles on
1396 	 * the orphans list that we can reinvestigate.
1397 	 */
1398 	if ((removed == 0) && hdl_list[HDLIST_ORP].head)
1399 		orphans = 1;
1400 	else
1401 		orphans = 0;
1402 
1403 	/*
1404 	 * Finally remove any handle infrastructure and remove any objects
1405 	 * marked for deletion.
1406 	 */
1407 	for (ALIST_TRAVERSE(ghalp, off1, ghpp)) {
1408 		Grp_hdl	*ghp = *ghpp;
1409 
1410 		/*
1411 		 * If we're not dealing with orphaned handles remove this handle
1412 		 * from its present handle list.
1413 		 */
1414 		if (removed == 0) {
1415 			uintptr_t ndx;
1416 
1417 			/* LINTED */
1418 			ndx = (uintptr_t)ghp % HDLIST_SZ;
1419 			list_delete(&hdl_list[ndx], ghp);
1420 		}
1421 
1422 		/*
1423 		 * Traverse each handle dependency.
1424 		 */
1425 		for (ALIST_TRAVERSE(ghp->gh_depends, off2, gdp)) {
1426 			if ((gdp->gd_flags & GPD_REMOVE) == 0)
1427 				continue;
1428 
1429 			lmp = gdp->gd_depend;
1430 			rmcnt++;
1431 
1432 			/*
1433 			 * If this object is the owner of the handle break that
1434 			 * association in case the handle is retained.
1435 			 */
1436 			if (ghp->gh_ownlmp == lmp) {
1437 				(void) alist_delete(HANDLES(lmp), &ghp, 0);
1438 				ghp->gh_ownlmp = 0;
1439 			}
1440 
1441 			(void) alist_delete(GROUPS(lmp), &ghp, 0);
1442 			(void) alist_delete(ghp->gh_depends, 0, &off2);
1443 
1444 			/*
1445 			 * Complete the link-map deletion if appropriate.
1446 			 */
1447 			if (FLAGS(lmp) & FLG_RT_DELETE) {
1448 				tls_modaddrem(lmp, TM_FLG_MODREM);
1449 				remove_so(LIST(lmp), lmp);
1450 			}
1451 		}
1452 
1453 		/*
1454 		 * If we've deleted all the dependencies of the handle, finalize
1455 		 * the cleanup by removing the handle itself.
1456 		 *
1457 		 * Otherwise we're left with a handle containing one or more
1458 		 * objects that can not be deleted (they're in use by other
1459 		 * handles, non-deletable, etc.), but require to remain a part
1460 		 * of this group to allow them to continue binding to one
1461 		 * another.
1462 		 *
1463 		 * If the handles reference count is zero, or represents a
1464 		 * link-map list (dlopen(0)), then move that handle to the
1465 		 * orphans list.  Should another dlclose() operation occur that
1466 		 * results in the removal of handle descriptors, these orphan
1467 		 * handles are re-examined to determine if their deletion can
1468 		 * be completed.
1469 		 */
1470 		if (ghp->gh_depends->al_data[0] == 0) {
1471 			free(ghp->gh_depends);
1472 			free(ghp);
1473 
1474 		} else if ((removed == 0) && (ghp->gh_refcnt == 0) &&
1475 		    ((ghp->gh_flags & GPH_ZERO) == 0)) {
1476 			/*
1477 			 * Move this handle to the orphans list.
1478 			 */
1479 			(void) list_append(&hdl_list[HDLIST_ORP], ghp);
1480 
1481 			if (DBG_ENABLED) {
1482 				DBG_CALL(Dbg_file_hdl_title(DBG_DEP_ORPHAN));
1483 				for (ALIST_TRAVERSE(ghp->gh_depends, off1, gdp))
1484 					DBG_CALL(Dbg_file_hdl_action(ghp,
1485 					    gdp->gd_depend, DBG_DEP_ORPHAN, 0));
1486 			}
1487 		}
1488 	}
1489 
1490 	/*
1491 	 * If no handle descriptors got removed there's no point in looking for
1492 	 * orphans to process.
1493 	 */
1494 	if (rmcnt == 0)
1495 		orphans = 0;
1496 
1497 	/*
1498 	 * Cleanup any alists we've created.
1499 	 */
1500 	remove_collect(ghalp, lmalp);
1501 
1502 	/*
1503 	 * If orphan processing isn't required we're done.  If our processing
1504 	 * originated from investigating orphans, return the number of handle
1505 	 * descriptors removed as an indication whether orphan processing
1506 	 * should continue.
1507 	 */
1508 	if (orphans == 0) {
1509 		if (removed)
1510 			*removed = rmcnt;
1511 		return (error);
1512 	}
1513 
1514 	/*
1515 	 * Traverse the orphans list as many times as necessary until no
1516 	 * handle removals occur.
1517 	 */
1518 	do {
1519 		List		list;
1520 		Listnode	*lnp;
1521 		Grp_hdl		*ghp, *oghp = 0;
1522 		int		title = 0;
1523 
1524 		/*
1525 		 * Effectively clean the HDLIST_ORP list.  Any object that can't
1526 		 * be removed will be re-added to the list.
1527 		 */
1528 		list = hdl_list[HDLIST_ORP];
1529 		hdl_list[HDLIST_ORP].head = hdl_list[HDLIST_ORP].tail = 0;
1530 
1531 		rescan = 0;
1532 		for (LIST_TRAVERSE(&list, lnp, ghp)) {
1533 			int	_error, _remove;
1534 
1535 			if (title++ == 0)
1536 				DBG_CALL(Dbg_file_del_rescan(ghp->gh_ownlml));
1537 
1538 			if (oghp) {
1539 				list_delete(&list, oghp);
1540 				oghp = 0;
1541 			}
1542 
1543 			if (((_error = remove_hdl(ghp, clmp, &_remove)) != 0) &&
1544 			    (error == 0))
1545 				error = _error;
1546 
1547 			if (_remove)
1548 				rescan++;
1549 
1550 			oghp = ghp;
1551 		}
1552 		if (oghp) {
1553 			list_delete(&list, oghp);
1554 			oghp = 0;
1555 		}
1556 
1557 	} while (rescan && hdl_list[HDLIST_ORP].head);
1558 
1559 	return (error);
1560 }
1561