xref: /titanic_51/usr/src/cmd/sgs/rtld/common/elf.c (revision 7f667e74610492ddbce8ce60f52ece95d2401949)
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 2009 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*
28  *	Copyright (c) 1988 AT&T
29  *	  All Rights Reserved
30  */
31 
32 /*
33  * Object file dependent support for ELF objects.
34  */
35 
36 #include	<stdio.h>
37 #include	<sys/procfs.h>
38 #include	<sys/mman.h>
39 #include	<sys/debug.h>
40 #include	<string.h>
41 #include	<limits.h>
42 #include	<dlfcn.h>
43 #include	<debug.h>
44 #include	<conv.h>
45 #include	"_rtld.h"
46 #include	"_audit.h"
47 #include	"_elf.h"
48 #include	"_inline.h"
49 #include	"msg.h"
50 
51 /*
52  * Default and secure dependency search paths.
53  */
54 static Spath_defn _elf_def_dirs[] = {
55 #if	defined(_ELF64)
56 	{ MSG_ORIG(MSG_PTH_LIB_64),		MSG_PTH_LIB_64_SIZE },
57 	{ MSG_ORIG(MSG_PTH_USRLIB_64),		MSG_PTH_USRLIB_64_SIZE },
58 #else
59 	{ MSG_ORIG(MSG_PTH_LIB),		MSG_PTH_LIB_SIZE },
60 	{ MSG_ORIG(MSG_PTH_USRLIB),		MSG_PTH_USRLIB_SIZE },
61 #endif
62 	{ 0, 0 }
63 };
64 
65 static Spath_defn _elf_sec_dirs[] = {
66 #if	defined(_ELF64)
67 	{ MSG_ORIG(MSG_PTH_LIBSE_64),		MSG_PTH_LIBSE_64_SIZE },
68 	{ MSG_ORIG(MSG_PTH_USRLIBSE_64),	MSG_PTH_USRLIBSE_64_SIZE },
69 #else
70 	{ MSG_ORIG(MSG_PTH_LIBSE),		MSG_PTH_LIBSE_SIZE },
71 	{ MSG_ORIG(MSG_PTH_USRLIBSE),		MSG_PTH_USRLIBSE_SIZE },
72 #endif
73 	{ 0, 0 }
74 };
75 
76 Alist	*elf_def_dirs = NULL;
77 Alist	*elf_sec_dirs = NULL;
78 
79 /*
80  * Defines for local functions.
81  */
82 static void	elf_dladdr(ulong_t, Rt_map *, Dl_info *, void **, int);
83 static Addr	elf_entry_point(void);
84 static int	elf_fix_name(const char *, Rt_map *, Alist **, Aliste, uint_t);
85 static Alist	**elf_get_def_dirs(void);
86 static Alist	**elf_get_sec_dirs(void);
87 static char	*elf_get_so(const char *, const char *, size_t, size_t);
88 static int	elf_needed(Lm_list *, Aliste, Rt_map *, int *);
89 
90 /*
91  * Functions and data accessed through indirect pointers.
92  */
93 Fct elf_fct = {
94 	elf_verify,
95 	elf_new_lmp,
96 	elf_entry_point,
97 	elf_needed,
98 	lookup_sym,
99 	elf_reloc,
100 	elf_get_def_dirs,
101 	elf_get_sec_dirs,
102 	elf_fix_name,
103 	elf_get_so,
104 	elf_dladdr,
105 	dlsym_handle
106 };
107 
108 /*
109  * Default and secure dependency search paths.
110  */
111 static Alist **
112 elf_get_def_dirs()
113 {
114 	if (elf_def_dirs == NULL)
115 		set_dirs(&elf_def_dirs, _elf_def_dirs, LA_SER_DEFAULT);
116 	return (&elf_def_dirs);
117 }
118 
119 static Alist **
120 elf_get_sec_dirs()
121 {
122 	if (elf_sec_dirs == NULL)
123 		set_dirs(&elf_sec_dirs, _elf_sec_dirs, LA_SER_SECURE);
124 	return (&elf_sec_dirs);
125 }
126 
127 /*
128  * Redefine NEEDED name if necessary.
129  */
130 static int
131 elf_fix_name(const char *name, Rt_map *clmp, Alist **alpp, Aliste alni,
132     uint_t orig)
133 {
134 	/*
135 	 * For ABI compliance, if we are asked for ld.so.1, then really give
136 	 * them libsys.so.1 (the SONAME of libsys.so.1 is ld.so.1).
137 	 */
138 	if (((*name == '/') &&
139 	/* BEGIN CSTYLED */
140 #if	defined(_ELF64)
141 	    (strcmp(name, MSG_ORIG(MSG_PTH_RTLD_64)) == 0)) ||
142 #else
143 	    (strcmp(name, MSG_ORIG(MSG_PTH_RTLD)) == 0)) ||
144 #endif
145 	    (strcmp(name, MSG_ORIG(MSG_FIL_RTLD)) == 0)) {
146 		/* END CSTYLED */
147 		Pdesc	*pdp;
148 
149 		DBG_CALL(Dbg_file_fixname(LIST(clmp), name,
150 		    MSG_ORIG(MSG_PTH_LIBSYS)));
151 		if ((pdp = alist_append(alpp, 0, sizeof (Pdesc), alni)) == NULL)
152 			return (0);
153 
154 		pdp->pd_pname = (char *)MSG_ORIG(MSG_PTH_LIBSYS);
155 		pdp->pd_plen = MSG_PTH_LIBSYS_SIZE;
156 		pdp->pd_flags = PD_FLG_PNSLASH;
157 
158 		return (1);
159 	}
160 
161 	return (expand_paths(clmp, name, alpp, alni, orig, 0));
162 }
163 
164 /*
165  * Determine whether this object requires any hardware or software capabilities.
166  */
167 static int
168 elf_cap_check(Fdesc *fdp, Ehdr *ehdr, Rej_desc *rej)
169 {
170 	Phdr	*phdr;
171 	int	cnt;
172 
173 	/* LINTED */
174 	phdr = (Phdr *)((char *)ehdr + ehdr->e_phoff);
175 	for (cnt = 0; cnt < ehdr->e_phnum; cnt++, phdr++) {
176 		Cap	*cptr;
177 
178 		if (phdr->p_type != PT_SUNWCAP)
179 			continue;
180 
181 		/* LINTED */
182 		cptr = (Cap *)((char *)ehdr + phdr->p_offset);
183 		while (cptr->c_tag != CA_SUNW_NULL) {
184 			if (cptr->c_tag == CA_SUNW_HW_1) {
185 				/*
186 				 * Verify the hardware capabilities.
187 				 */
188 				if (hwcap_check(cptr->c_un.c_val, rej) == 0)
189 					return (0);
190 
191 				/*
192 				 * Retain this hardware capabilities value for
193 				 * possible later inspection should this object
194 				 * be processed as a filtee.
195 				 */
196 				fdp->fd_hwcap = cptr->c_un.c_val;
197 			}
198 			if (cptr->c_tag == CA_SUNW_SF_1) {
199 				/*
200 				 * Verify the software capabilities.
201 				 */
202 				if (sfcap_check(cptr->c_un.c_val, rej) == 0)
203 					return (0);
204 			}
205 			cptr++;
206 		}
207 	}
208 	return (1);
209 }
210 
211 /*
212  * Determine if we have been given an ELF file and if so determine if the file
213  * is compatible.  Returns 1 if true, else 0 and sets the reject descriptor
214  * with associated error information.
215  */
216 Fct *
217 elf_verify(caddr_t addr, size_t size, Fdesc *fdp, const char *name,
218     Rej_desc *rej)
219 {
220 	Ehdr	*ehdr;
221 	char	*caddr = (char *)addr;
222 
223 	/*
224 	 * Determine if we're an elf file.  If not simply return, we don't set
225 	 * any rejection information as this test allows use to scroll through
226 	 * the objects we support (ELF, AOUT).
227 	 */
228 	if (size < sizeof (Ehdr) ||
229 	    caddr[EI_MAG0] != ELFMAG0 ||
230 	    caddr[EI_MAG1] != ELFMAG1 ||
231 	    caddr[EI_MAG2] != ELFMAG2 ||
232 	    caddr[EI_MAG3] != ELFMAG3) {
233 		return (NULL);
234 	}
235 
236 	/*
237 	 * Check class and encoding.
238 	 */
239 	/* LINTED */
240 	ehdr = (Ehdr *)addr;
241 	if (ehdr->e_ident[EI_CLASS] != M_CLASS) {
242 		rej->rej_type = SGS_REJ_CLASS;
243 		rej->rej_info = (uint_t)ehdr->e_ident[EI_CLASS];
244 		return (NULL);
245 	}
246 	if (ehdr->e_ident[EI_DATA] != M_DATA) {
247 		rej->rej_type = SGS_REJ_DATA;
248 		rej->rej_info = (uint_t)ehdr->e_ident[EI_DATA];
249 		return (NULL);
250 	}
251 	if ((ehdr->e_type != ET_REL) && (ehdr->e_type != ET_EXEC) &&
252 	    (ehdr->e_type != ET_DYN)) {
253 		rej->rej_type = SGS_REJ_TYPE;
254 		rej->rej_info = (uint_t)ehdr->e_type;
255 		return (NULL);
256 	}
257 
258 	/*
259 	 * Verify ELF version.
260 	 */
261 	if (ehdr->e_version > EV_CURRENT) {
262 		rej->rej_type = SGS_REJ_VERSION;
263 		rej->rej_info = (uint_t)ehdr->e_version;
264 		return (NULL);
265 	}
266 
267 	/*
268 	 * Verify machine specific flags.
269 	 */
270 	if (elf_mach_flags_check(rej, ehdr) == 0)
271 		return (NULL);
272 
273 	/*
274 	 * Verify any hardware/software capability requirements.  Note, if this
275 	 * object is an explicitly defined shared object under inspection by
276 	 * ldd(1), and contains an incompatible hardware capabilities
277 	 * requirement, then inform the user, but continue processing.
278 	 */
279 	if (elf_cap_check(fdp, ehdr, rej) == 0) {
280 		Rt_map	*lmp = lml_main.lm_head;
281 
282 		if ((lml_main.lm_flags & LML_FLG_TRC_LDDSTUB) &&
283 		    (lmp != NULL) && (FLAGS1(lmp) & FL1_RT_LDDSTUB) &&
284 		    (NEXT(lmp) == NULL)) {
285 			const char	*fmt;
286 
287 			if (rej->rej_type == SGS_REJ_HWCAP_1)
288 				fmt = MSG_INTL(MSG_LDD_GEN_HWCAP_1);
289 			else
290 				fmt = MSG_INTL(MSG_LDD_GEN_SFCAP_1);
291 			(void) printf(fmt, name, rej->rej_str);
292 			return (&elf_fct);
293 		}
294 		return (NULL);
295 	}
296 	return (&elf_fct);
297 }
298 
299 /*
300  * The runtime linker employs lazy loading to provide the libraries needed for
301  * debugging, preloading .o's and dldump().  As these are seldom used, the
302  * standard startup of ld.so.1 doesn't initialize all the information necessary
303  * to perform plt relocation on ld.so.1's link-map.  The first time lazy loading
304  * is called we get here to perform these initializations:
305  *
306  *  o	elf_needed() is called to set up the DYNINFO() indexes for each lazy
307  *	dependency.  Typically, for all other objects, this is called during
308  *	analyze_so(), but as ld.so.1 is set-contained we skip this processing.
309  *
310  *  o	For intel, ld.so.1's JMPSLOT relocations need relative updates. These
311  *	are by default skipped thus delaying all relative relocation processing
312  * 	on every invocation of ld.so.1.
313  */
314 int
315 elf_rtld_load()
316 {
317 	Lm_list	*lml = &lml_rtld;
318 	Rt_map	*lmp = lml->lm_head;
319 
320 	if (lml->lm_flags & LML_FLG_PLTREL)
321 		return (1);
322 
323 	/*
324 	 * As we need to refer to the DYNINFO() information, insure that it has
325 	 * been initialized.
326 	 */
327 	if (elf_needed(lml, ALIST_OFF_DATA, lmp, NULL) == 0)
328 		return (0);
329 
330 #if	defined(__i386)
331 	/*
332 	 * This is a kludge to give ld.so.1 a performance benefit on i386.
333 	 * It's based around two factors.
334 	 *
335 	 *  o	JMPSLOT relocations (PLT's) actually need a relative relocation
336 	 *	applied to the GOT entry so that they can find PLT0.
337 	 *
338 	 *  o	ld.so.1 does not exercise *any* PLT's before it has made a call
339 	 *	to elf_lazy_load().  This is because all dynamic dependencies
340 	 * 	are recorded as lazy dependencies.
341 	 */
342 	(void) elf_reloc_relative_count((ulong_t)JMPREL(lmp),
343 	    (ulong_t)(PLTRELSZ(lmp) / RELENT(lmp)), (ulong_t)RELENT(lmp),
344 	    (ulong_t)ADDR(lmp), lmp, NULL);
345 #endif
346 
347 	lml->lm_flags |= LML_FLG_PLTREL;
348 	return (1);
349 }
350 
351 /*
352  * Lazy load an object.
353  */
354 Rt_map *
355 elf_lazy_load(Rt_map *clmp, Slookup *slp, uint_t ndx, const char *sym,
356     int *in_nfavl)
357 {
358 	Alist		*palp = NULL;
359 	Rt_map		*nlmp, *hlmp;
360 	Dyninfo		*dip = &DYNINFO(clmp)[ndx], *pdip;
361 	uint_t		flags = 0;
362 	const char	*name;
363 	Lm_list		*lml = LIST(clmp);
364 	Lm_cntl		*lmc;
365 	Aliste		lmco;
366 
367 	/*
368 	 * If this dependency has already been processed, we're done.
369 	 */
370 	if (((nlmp = (Rt_map *)dip->di_info) != NULL) ||
371 	    (dip->di_flags & FLG_DI_LDD_DONE))
372 		return (nlmp);
373 
374 	/*
375 	 * If we're running under ldd(1), indicate that this dependency has been
376 	 * processed (see test above).  It doesn't matter whether the object is
377 	 * successfully loaded or not, this flag simply ensures that we don't
378 	 * repeatedly attempt to load an object that has already failed to load.
379 	 * To do so would create multiple failure diagnostics for the same
380 	 * object under ldd(1).
381 	 */
382 	if (lml->lm_flags & LML_FLG_TRC_ENABLE)
383 		dip->di_flags |= FLG_DI_LDD_DONE;
384 
385 	/*
386 	 * Determine the initial dependency name.
387 	 */
388 	name = STRTAB(clmp) + DYN(clmp)[ndx].d_un.d_val;
389 	DBG_CALL(Dbg_file_lazyload(clmp, name, sym));
390 
391 	/*
392 	 * If this object needs to establish its own group, make sure a handle
393 	 * is created.
394 	 */
395 	if (dip->di_flags & FLG_DI_GROUP)
396 		flags |= (FLG_RT_SETGROUP | FLG_RT_HANDLE);
397 
398 	/*
399 	 * Lazy dependencies are identified as DT_NEEDED entries with a
400 	 * DF_P1_LAZYLOAD flag in the previous DT_POSFLAG_1 element.  The
401 	 * dynamic information element that corresponds to the DT_POSFLAG_1
402 	 * entry is free, and thus used to store the present entrance
403 	 * identifier.  This identifier is used to prevent multiple attempts to
404 	 * load a failed lazy loadable dependency within the same runtime linker
405 	 * operation.  However, future attempts to reload this dependency are
406 	 * still possible.
407 	 */
408 	if (ndx && (pdip = dip - 1) && (pdip->di_flags & FLG_DI_POSFLAG1))
409 		pdip->di_info = (void *)slp->sl_id;
410 
411 	/*
412 	 * Expand the requested name if necessary.
413 	 */
414 	if (elf_fix_name(name, clmp, &palp, AL_CNT_NEEDED, 0) == 0)
415 		return (NULL);
416 
417 	/*
418 	 * Provided the object on the head of the link-map has completed its
419 	 * relocation, create a new link-map control list for this request.
420 	 */
421 	hlmp = lml->lm_head;
422 	if (FLAGS(hlmp) & FLG_RT_RELOCED) {
423 		if ((lmc = alist_append(&lml->lm_lists, 0, sizeof (Lm_cntl),
424 		    AL_CNT_LMLISTS)) == NULL) {
425 			remove_plist(&palp, 1);
426 			return (NULL);
427 		}
428 		lmco = (Aliste)((char *)lmc - (char *)lml->lm_lists);
429 	} else {
430 		lmc = 0;
431 		lmco = ALIST_OFF_DATA;
432 	}
433 
434 	/*
435 	 * Load the associated object.
436 	 */
437 	dip->di_info = nlmp =
438 	    load_one(lml, lmco, palp, clmp, MODE(clmp), flags, 0, in_nfavl);
439 
440 	/*
441 	 * Remove any expanded pathname infrastructure.  Reduce the pending lazy
442 	 * dependency count of the caller, together with the link-map lists
443 	 * count of objects that still have lazy dependencies pending.
444 	 */
445 	remove_plist(&palp, 1);
446 	if (--LAZY(clmp) == 0)
447 		LIST(clmp)->lm_lazy--;
448 
449 	/*
450 	 * Finish processing the objects associated with this request, and
451 	 * create an association between the caller and this dependency.
452 	 */
453 	if (nlmp && ((bind_one(clmp, nlmp, BND_NEEDED) == 0) ||
454 	    ((nlmp = analyze_lmc(lml, lmco, nlmp, in_nfavl)) == NULL) ||
455 	    (relocate_lmc(lml, lmco, clmp, nlmp, in_nfavl) == 0)))
456 		dip->di_info = nlmp = NULL;
457 
458 	/*
459 	 * If this lazyload has failed, and we've created a new link-map
460 	 * control list to which this request has added objects, then remove
461 	 * all the objects that have been associated to this request.
462 	 */
463 	if ((nlmp == NULL) && lmc && lmc->lc_head)
464 		remove_lmc(lml, clmp, lmc, lmco, name);
465 
466 	/*
467 	 * Finally, remove any link-map control list that was created.
468 	 */
469 	if (lmc)
470 		remove_cntl(lml, lmco);
471 
472 	/*
473 	 * If this lazy loading failed, record the fact, and bump the lazy
474 	 * counts.
475 	 */
476 	if (nlmp == NULL) {
477 		dip->di_flags |= FLG_DI_LAZYFAIL;
478 		if (LAZY(clmp)++ == 0)
479 			LIST(clmp)->lm_lazy++;
480 	}
481 
482 	return (nlmp);
483 }
484 
485 /*
486  * Return the entry point of the ELF executable.
487  */
488 static Addr
489 elf_entry_point(void)
490 {
491 	Rt_map	*lmp = lml_main.lm_head;
492 	Ehdr	*ehdr = (Ehdr *)ADDR(lmp);
493 	Addr	addr = (Addr)(ehdr->e_entry);
494 
495 	if ((FLAGS(lmp) & FLG_RT_FIXED) == 0)
496 		addr += ADDR(lmp);
497 
498 	return (addr);
499 }
500 
501 /*
502  * Determine if a dependency requires a particular version and if so verify
503  * that the version exists in the dependency.
504  */
505 int
506 elf_verify_vers(const char *name, Rt_map *clmp, Rt_map *nlmp)
507 {
508 	Verneed		*vnd = VERNEED(clmp);
509 	int		_num, num = VERNEEDNUM(clmp);
510 	char		*cstrs = (char *)STRTAB(clmp);
511 	Lm_list		*lml = LIST(clmp);
512 
513 	/*
514 	 * Traverse the callers version needed information and determine if any
515 	 * specific versions are required from the dependency.
516 	 */
517 	DBG_CALL(Dbg_ver_need_title(LIST(clmp), NAME(clmp)));
518 	for (_num = 1; _num <= num; _num++,
519 	    vnd = (Verneed *)((Xword)vnd + vnd->vn_next)) {
520 		Half		cnt = vnd->vn_cnt;
521 		Vernaux		*vnap;
522 		char		*nstrs, *need;
523 
524 		/*
525 		 * Determine if a needed entry matches this dependency.
526 		 */
527 		need = (char *)(cstrs + vnd->vn_file);
528 		if (strcmp(name, need) != 0)
529 			continue;
530 
531 		if ((lml->lm_flags & LML_FLG_TRC_VERBOSE) &&
532 		    ((FLAGS1(clmp) & FL1_RT_LDDSTUB) == 0))
533 			(void) printf(MSG_INTL(MSG_LDD_VER_FIND), name);
534 
535 		/*
536 		 * Validate that each version required actually exists in the
537 		 * dependency.
538 		 */
539 		nstrs = (char *)STRTAB(nlmp);
540 
541 		for (vnap = (Vernaux *)((Xword)vnd + vnd->vn_aux); cnt;
542 		    cnt--, vnap = (Vernaux *)((Xword)vnap + vnap->vna_next)) {
543 			char		*version, *define;
544 			Verdef		*vdf = VERDEF(nlmp);
545 			ulong_t		_num, num = VERDEFNUM(nlmp);
546 			int		found = 0;
547 
548 			/*
549 			 * Skip validation of versions that are marked
550 			 * INFO. This optimization is used for versions
551 			 * that are inherited by another version. Verification
552 			 * of the inheriting version is sufficient.
553 			 *
554 			 * Such versions are recorded in the object for the
555 			 * benefit of VERSYM entries that refer to them. This
556 			 * provides a purely diagnositic benefit.
557 			 */
558 			if (vnap->vna_flags & VER_FLG_INFO)
559 				continue;
560 
561 			version = (char *)(cstrs + vnap->vna_name);
562 			DBG_CALL(Dbg_ver_need_entry(lml, 0, need, version));
563 
564 			for (_num = 1; _num <= num; _num++,
565 			    vdf = (Verdef *)((Xword)vdf + vdf->vd_next)) {
566 				Verdaux		*vdap;
567 
568 				if (vnap->vna_hash != vdf->vd_hash)
569 					continue;
570 
571 				vdap = (Verdaux *)((Xword)vdf + vdf->vd_aux);
572 				define = (char *)(nstrs + vdap->vda_name);
573 				if (strcmp(version, define) != 0)
574 					continue;
575 
576 				found++;
577 				break;
578 			}
579 
580 			/*
581 			 * If we're being traced print out any matched version
582 			 * when the verbose (-v) option is in effect.  Always
583 			 * print any unmatched versions.
584 			 */
585 			if (lml->lm_flags & LML_FLG_TRC_ENABLE) {
586 				/* BEGIN CSTYLED */
587 				if (found) {
588 				    if (!(lml->lm_flags & LML_FLG_TRC_VERBOSE))
589 					continue;
590 
591 				    (void) printf(MSG_ORIG(MSG_LDD_VER_FOUND),
592 					need, version, NAME(nlmp));
593 				} else {
594 				    if (rtld_flags & RT_FL_SILENCERR)
595 					continue;
596 
597 				    (void) printf(MSG_INTL(MSG_LDD_VER_NFOUND),
598 					need, version);
599 				}
600 				/* END CSTYLED */
601 				continue;
602 			}
603 
604 			/*
605 			 * If the version hasn't been found then this is a
606 			 * candidate for a fatal error condition.  Weak
607 			 * version definition requirements are silently
608 			 * ignored.  Also, if the image inspected for a version
609 			 * definition has no versioning recorded at all then
610 			 * silently ignore this (this provides better backward
611 			 * compatibility to old images created prior to
612 			 * versioning being available).  Both of these skipped
613 			 * diagnostics are available under tracing (see above).
614 			 */
615 			if ((found == 0) && (num != 0) &&
616 			    (!(vnap->vna_flags & VER_FLG_WEAK))) {
617 				eprintf(lml, ERR_FATAL,
618 				    MSG_INTL(MSG_VER_NFOUND), need, version,
619 				    NAME(clmp));
620 				return (0);
621 			}
622 		}
623 	}
624 	DBG_CALL(Dbg_util_nl(lml, DBG_NL_STD));
625 	return (1);
626 }
627 
628 /*
629  * Search through the dynamic section for DT_NEEDED entries and perform one
630  * of two functions.  If only the first argument is specified then load the
631  * defined shared object, otherwise add the link map representing the defined
632  * link map the the dlopen list.
633  */
634 static int
635 elf_needed(Lm_list *lml, Aliste lmco, Rt_map *clmp, int *in_nfavl)
636 {
637 	Alist		*palp = NULL;
638 	Dyn		*dyn, *pdyn;
639 	ulong_t		ndx = 0;
640 	uint_t		lazy, flags;
641 	Word		lmflags = lml->lm_flags;
642 	Word		lmtflags = lml->lm_tflags;
643 
644 	/*
645 	 * Process each shared object on needed list.
646 	 */
647 	if (DYN(clmp) == 0)
648 		return (1);
649 
650 	for (dyn = (Dyn *)DYN(clmp), pdyn = NULL; dyn->d_tag != DT_NULL;
651 	    pdyn = dyn++, ndx++) {
652 		Dyninfo	*dip = &DYNINFO(clmp)[ndx];
653 		Rt_map	*nlmp = 0;
654 		char	*name;
655 		int	silent = 0;
656 
657 		switch (dyn->d_tag) {
658 		case DT_POSFLAG_1:
659 			dip->di_flags |= FLG_DI_POSFLAG1;
660 			continue;
661 		case DT_NEEDED:
662 		case DT_USED:
663 			lazy = flags = 0;
664 			dip->di_flags |= FLG_DI_NEEDED;
665 
666 			if (pdyn && (pdyn->d_tag == DT_POSFLAG_1)) {
667 				if ((pdyn->d_un.d_val & DF_P1_LAZYLOAD) &&
668 				    ((lmtflags & LML_TFLG_NOLAZYLD) == 0)) {
669 					dip->di_flags |= FLG_DI_LAZY;
670 					lazy = 1;
671 				}
672 				if (pdyn->d_un.d_val & DF_P1_GROUPPERM) {
673 					dip->di_flags |= FLG_DI_GROUP;
674 					flags =
675 					    (FLG_RT_SETGROUP | FLG_RT_HANDLE);
676 				}
677 			}
678 
679 			name = (char *)STRTAB(clmp) + dyn->d_un.d_val;
680 
681 			/*
682 			 * NOTE, libc.so.1 can't be lazy loaded.  Although a
683 			 * lazy position flag won't be produced when a RTLDINFO
684 			 * .dynamic entry is found (introduced with the UPM in
685 			 * Solaris 10), it was possible to mark libc for lazy
686 			 * loading on previous releases.  To reduce the overhead
687 			 * of testing for this occurrence, only carry out this
688 			 * check for the first object on the link-map list
689 			 * (there aren't many applications built without libc).
690 			 */
691 			if (lazy && (lml->lm_head == clmp) &&
692 			    (strcmp(name, MSG_ORIG(MSG_FIL_LIBC)) == 0))
693 				lazy = 0;
694 
695 			/*
696 			 * Don't bring in lazy loaded objects yet unless we've
697 			 * been asked to attempt to load all available objects
698 			 * (crle(1) sets LD_FLAGS=loadavail).  Even under
699 			 * RTLD_NOW we don't process this - RTLD_NOW will cause
700 			 * relocation processing which in turn might trigger
701 			 * lazy loading, but its possible that the object has a
702 			 * lazy loaded file with no bindings (i.e., it should
703 			 * never have been a dependency in the first place).
704 			 */
705 			if (lazy) {
706 				if ((lmflags & LML_FLG_LOADAVAIL) == 0) {
707 					LAZY(clmp)++;
708 					lazy = flags = 0;
709 					continue;
710 				}
711 
712 				/*
713 				 * Silence any error messages - see description
714 				 * under elf_lookup_filtee().
715 				 */
716 				if ((rtld_flags & RT_FL_SILENCERR) == 0) {
717 					rtld_flags |= RT_FL_SILENCERR;
718 					silent = 1;
719 				}
720 			}
721 			break;
722 		case DT_AUXILIARY:
723 			dip->di_flags |= FLG_DI_AUXFLTR;
724 			continue;
725 		case DT_SUNW_AUXILIARY:
726 			dip->di_flags |= (FLG_DI_AUXFLTR | FLG_DI_SYMFLTR);
727 			continue;
728 		case DT_FILTER:
729 			dip->di_flags |= FLG_DI_STDFLTR;
730 			continue;
731 		case DT_SUNW_FILTER:
732 			dip->di_flags |= (FLG_DI_STDFLTR | FLG_DI_SYMFLTR);
733 			continue;
734 		default:
735 			continue;
736 		}
737 
738 		DBG_CALL(Dbg_file_needed(clmp, name));
739 
740 		/*
741 		 * If we're running under ldd(1), indicate that this dependency
742 		 * has been processed.  It doesn't matter whether the object is
743 		 * successfully loaded or not, this flag simply ensures that we
744 		 * don't repeatedly attempt to load an object that has already
745 		 * failed to load.  To do so would create multiple failure
746 		 * diagnostics for the same object under ldd(1).
747 		 */
748 		if (lml->lm_flags & LML_FLG_TRC_ENABLE)
749 			dip->di_flags |= FLG_DI_LDD_DONE;
750 
751 		/*
752 		 * Establish the objects name, load it and establish a binding
753 		 * with the caller.
754 		 */
755 		if ((elf_fix_name(name, clmp, &palp, AL_CNT_NEEDED, 0) == 0) ||
756 		    ((nlmp = load_one(lml, lmco, palp, clmp, MODE(clmp),
757 		    flags, 0, in_nfavl)) == NULL) ||
758 		    (bind_one(clmp, nlmp, BND_NEEDED) == 0))
759 			nlmp = 0;
760 
761 		/*
762 		 * Clean up any infrastructure, including the removal of the
763 		 * error suppression state, if it had been previously set in
764 		 * this routine.
765 		 */
766 		remove_plist(&palp, 0);
767 
768 		if (silent)
769 			rtld_flags &= ~RT_FL_SILENCERR;
770 
771 		if ((dip->di_info = (void *)nlmp) == 0) {
772 			/*
773 			 * If the object could not be mapped, continue if error
774 			 * suppression is established or we're here with ldd(1).
775 			 */
776 			if ((MODE(clmp) & RTLD_CONFGEN) || (lmflags &
777 			    (LML_FLG_LOADAVAIL | LML_FLG_TRC_ENABLE)))
778 				continue;
779 			else {
780 				remove_plist(&palp, 1);
781 				return (0);
782 			}
783 		}
784 	}
785 
786 	if (LAZY(clmp))
787 		lml->lm_lazy++;
788 
789 	remove_plist(&palp, 1);
790 	return (1);
791 }
792 
793 /*
794  * A null symbol interpretor.  Used if a filter has no associated filtees.
795  */
796 /* ARGSUSED0 */
797 static Sym *
798 elf_null_find_sym(Slookup *slp, Rt_map **dlmp, uint_t *binfo, int *in_nfavl)
799 {
800 	return (NULL);
801 }
802 
803 /*
804  * Disable filtee use.
805  */
806 static void
807 elf_disable_filtee(Rt_map *lmp, Dyninfo *dip)
808 {
809 	if ((dip->di_flags & FLG_DI_SYMFLTR) == 0) {
810 		/*
811 		 * If this is an object filter, null out the reference name.
812 		 */
813 		if (OBJFLTRNDX(lmp) != FLTR_DISABLED) {
814 			REFNAME(lmp) = NULL;
815 			OBJFLTRNDX(lmp) = FLTR_DISABLED;
816 
817 			/*
818 			 * Indicate that this filtee is no longer available.
819 			 */
820 			if (dip->di_flags & FLG_DI_STDFLTR)
821 				SYMINTP(lmp) = elf_null_find_sym;
822 
823 		}
824 	} else if (dip->di_flags & FLG_DI_STDFLTR) {
825 		/*
826 		 * Indicate that this standard filtee is no longer available.
827 		 */
828 		if (SYMSFLTRCNT(lmp))
829 			SYMSFLTRCNT(lmp)--;
830 	} else {
831 		/*
832 		 * Indicate that this auxiliary filtee is no longer available.
833 		 */
834 		if (SYMAFLTRCNT(lmp))
835 			SYMAFLTRCNT(lmp)--;
836 	}
837 	dip->di_flags &= ~MSK_DI_FILTER;
838 }
839 
840 /*
841  * Find symbol interpreter - filters.
842  * This function is called when the symbols from a shared object should
843  * be resolved from the shared objects filtees instead of from within itself.
844  *
845  * A symbol name of 0 is used to trigger filtee loading.
846  */
847 static Sym *
848 _elf_lookup_filtee(Slookup *slp, Rt_map **dlmp, uint_t *binfo, uint_t ndx,
849     int *in_nfavl)
850 {
851 	const char	*name = slp->sl_name, *filtees;
852 	Rt_map		*clmp = slp->sl_cmap;
853 	Rt_map		*ilmp = slp->sl_imap;
854 	Pdesc		*pdp;
855 	int		any;
856 	Dyninfo		*dip = &DYNINFO(ilmp)[ndx];
857 	Lm_list		*lml = LIST(ilmp);
858 	Aliste		idx;
859 
860 	/*
861 	 * Indicate that the filter has been used.  If a binding already exists
862 	 * to the caller, indicate that this object is referenced.  This insures
863 	 * we don't generate false unreferenced diagnostics from ldd -u/U or
864 	 * debugging.  Don't create a binding regardless, as this filter may
865 	 * have been dlopen()'ed.
866 	 */
867 	if (name && (ilmp != clmp)) {
868 		Word	tracing = (LIST(clmp)->lm_flags &
869 		    (LML_FLG_TRC_UNREF | LML_FLG_TRC_UNUSED));
870 
871 		if (tracing || DBG_ENABLED) {
872 			Bnd_desc 	*bdp;
873 			Aliste		idx;
874 
875 			FLAGS1(ilmp) |= FL1_RT_USED;
876 
877 			if ((tracing & LML_FLG_TRC_UNREF) || DBG_ENABLED) {
878 				for (APLIST_TRAVERSE(CALLERS(ilmp), idx, bdp)) {
879 					if (bdp->b_caller == clmp) {
880 						bdp->b_flags |= BND_REFER;
881 						break;
882 					}
883 				}
884 			}
885 		}
886 	}
887 
888 	/*
889 	 * If this is the first call to process this filter, establish the
890 	 * filtee list.  If a configuration file exists, determine if any
891 	 * filtee associations for this filter, and its filtee reference, are
892 	 * defined.  Otherwise, process the filtee reference.  Any token
893 	 * expansion is also completed at this point (i.e., $PLATFORM).
894 	 */
895 	filtees = (char *)STRTAB(ilmp) + DYN(ilmp)[ndx].d_un.d_val;
896 	if (dip->di_info == 0) {
897 		if (rtld_flags2 & RT_FL2_FLTCFG)
898 			elf_config_flt(lml, PATHNAME(ilmp), filtees,
899 			    (Alist **)&dip->di_info, AL_CNT_FILTEES);
900 
901 		if (dip->di_info == 0) {
902 			DBG_CALL(Dbg_file_filter(lml, NAME(ilmp), filtees, 0));
903 			if ((lml->lm_flags &
904 			    (LML_FLG_TRC_VERBOSE | LML_FLG_TRC_SEARCH)) &&
905 			    ((FLAGS1(ilmp) & FL1_RT_LDDSTUB) == 0))
906 				(void) printf(MSG_INTL(MSG_LDD_FIL_FILTER),
907 				    NAME(ilmp), filtees);
908 
909 			if (expand_paths(ilmp, filtees, (Alist **)&dip->di_info,
910 			    AL_CNT_FILTEES, 0, 0) == 0) {
911 				elf_disable_filtee(ilmp, dip);
912 				return (NULL);
913 			}
914 		}
915 	}
916 
917 	/*
918 	 * Traverse the filtee list, dlopen()'ing any objects specified and
919 	 * using their group handle to lookup the symbol.
920 	 */
921 	any = 0;
922 	for (ALIST_TRAVERSE((Alist *)dip->di_info, idx, pdp)) {
923 		int	mode;
924 		Grp_hdl	*ghp;
925 		Rt_map	*nlmp = 0;
926 
927 		if (pdp->pd_plen == 0)
928 			continue;
929 
930 		/*
931 		 * Establish the mode of the filtee from the filter.  As filtees
932 		 * are loaded via a dlopen(), make sure that RTLD_GROUP is set
933 		 * and the filtees aren't global.  It would be nice to have
934 		 * RTLD_FIRST used here also, but as filters got out long before
935 		 * RTLD_FIRST was introduced it's a little too late now.
936 		 */
937 		mode = MODE(ilmp) | RTLD_GROUP;
938 		mode &= ~RTLD_GLOBAL;
939 
940 		/*
941 		 * Insure that any auxiliary filter can locate symbols from its
942 		 * caller.
943 		 */
944 		if (dip->di_flags & FLG_DI_AUXFLTR)
945 			mode |= RTLD_PARENT;
946 
947 		/*
948 		 * Process any hardware capability directory.  Establish a new
949 		 * link-map control list from which to analyze any newly added
950 		 * objects.
951 		 */
952 		if ((pdp->pd_info == 0) && (pdp->pd_flags & PD_TKN_HWCAP)) {
953 			const char	*dir = pdp->pd_pname;
954 			Lm_cntl		*lmc;
955 			Aliste		lmco;
956 
957 			if (FLAGS(lml->lm_head) & FLG_RT_RELOCED) {
958 				if ((lmc = alist_append(&lml->lm_lists, 0,
959 				    sizeof (Lm_cntl), AL_CNT_LMLISTS)) == NULL)
960 					return (NULL);
961 				lmco = (Aliste)((char *)lmc -
962 				    (char *)lml->lm_lists);
963 			} else {
964 				lmc = 0;
965 				lmco = ALIST_OFF_DATA;
966 			}
967 
968 			/*
969 			 * Determine the hardware capability filtees.  If none
970 			 * can be found, provide suitable diagnostics.
971 			 */
972 			DBG_CALL(Dbg_cap_hw_filter(lml, dir, ilmp));
973 			if (hwcap_filtees((Alist **)&dip->di_info, idx, dir,
974 			    lmco, lmc, ilmp, filtees, mode,
975 			    (FLG_RT_HANDLE | FLG_RT_HWCAP), in_nfavl) == 0) {
976 				if ((lml->lm_flags & LML_FLG_TRC_ENABLE) &&
977 				    (dip->di_flags & FLG_DI_AUXFLTR) &&
978 				    (rtld_flags & RT_FL_WARNFLTR)) {
979 					(void) printf(
980 					    MSG_INTL(MSG_LDD_HWCAP_NFOUND),
981 					    dir);
982 				}
983 				DBG_CALL(Dbg_cap_hw_filter(lml, dir, 0));
984 			}
985 
986 			/*
987 			 * Re-establish the originating path name descriptor, as
988 			 * the expansion of hardware capabilities filtees may
989 			 * have re-allocated the controlling Alist.  Mark this
990 			 * original pathname descriptor as unused so that the
991 			 * descriptor isn't revisited for processing.  Any real
992 			 * hardware capabilities filtees have been added as new
993 			 * pathname descriptors following this descriptor.
994 			 */
995 			pdp = alist_item((Alist *)dip->di_info, idx);
996 			pdp->pd_flags &= ~PD_TKN_HWCAP;
997 			pdp->pd_plen = 0;
998 
999 			/*
1000 			 * Now that any hardware capability objects have been
1001 			 * processed, remove any link-map control list.
1002 			 */
1003 			if (lmc)
1004 				remove_cntl(lml, lmco);
1005 		}
1006 
1007 		if (pdp->pd_plen == 0)
1008 			continue;
1009 
1010 		/*
1011 		 * Process an individual filtee.
1012 		 */
1013 		if (pdp->pd_info == 0) {
1014 			const char	*filtee = pdp->pd_pname;
1015 			int		audit = 0;
1016 
1017 			DBG_CALL(Dbg_file_filtee(lml, NAME(ilmp), filtee, 0));
1018 
1019 			ghp = 0;
1020 
1021 			/*
1022 			 * Determine if the reference link map is already
1023 			 * loaded.  As an optimization compare the filtee with
1024 			 * our interpretor.  The most common filter is
1025 			 * libdl.so.1, which is a filter on ld.so.1.
1026 			 */
1027 #if	defined(_ELF64)
1028 			if (strcmp(filtee, MSG_ORIG(MSG_PTH_RTLD_64)) == 0) {
1029 #else
1030 			if (strcmp(filtee, MSG_ORIG(MSG_PTH_RTLD)) == 0) {
1031 #endif
1032 				/*
1033 				 * Create an association between ld.so.1 and the
1034 				 * filter.  As an optimization, a handle for
1035 				 * ld.so.1 itself (required for the dlopen()
1036 				 * family filtering mechanism) shouldn't search
1037 				 * any dependencies of ld.so.1.  Omitting
1038 				 * GPD_ADDEPS prevents the addition of any
1039 				 * ld.so.1 dependencies to this handle.
1040 				 */
1041 				nlmp = lml_rtld.lm_head;
1042 				if ((ghp = hdl_create(&lml_rtld, nlmp, ilmp,
1043 				    (GPH_LDSO | GPH_FIRST | GPH_FILTEE),
1044 				    (GPD_DLSYM | GPD_RELOC), GPD_PARENT)) == 0)
1045 					nlmp = 0;
1046 
1047 				/*
1048 				 * Establish the filter handle to prevent any
1049 				 * recursion.
1050 				 */
1051 				if (nlmp && ghp)
1052 					pdp->pd_info = (void *)ghp;
1053 
1054 				/*
1055 				 * Audit the filter/filtee established.  Ignore
1056 				 * any return from the auditor, as we can't
1057 				 * allow ignore filtering to ld.so.1, otherwise
1058 				 * nothing is going to work.
1059 				 */
1060 				if (nlmp && ((lml->lm_tflags | AFLAGS(ilmp)) &
1061 				    LML_TFLG_AUD_OBJFILTER))
1062 					(void) audit_objfilter(ilmp, filtees,
1063 					    nlmp, 0);
1064 
1065 			} else {
1066 				Rej_desc	rej = { 0 };
1067 				Fdesc		fd = { 0 };
1068 				Lm_cntl		*lmc;
1069 				Aliste		lmco;
1070 
1071 				/*
1072 				 * Trace the inspection of this file, determine
1073 				 * any auditor substitution, and seed the file
1074 				 * descriptor with the originating name.
1075 				 */
1076 				if (load_trace(lml, pdp, clmp, &fd) == NULL)
1077 					continue;
1078 
1079 				/*
1080 				 * Establish a new link-map control list from
1081 				 * which to analyze any newly added objects.
1082 				 */
1083 				if (FLAGS(lml->lm_head) & FLG_RT_RELOCED) {
1084 					if ((lmc =
1085 					    alist_append(&lml->lm_lists, 0,
1086 					    sizeof (Lm_cntl),
1087 					    AL_CNT_LMLISTS)) == NULL)
1088 						return (NULL);
1089 					lmco = (Aliste)((char *)lmc -
1090 					    (char *)lml->lm_lists);
1091 				} else {
1092 					lmc = 0;
1093 					lmco = ALIST_OFF_DATA;
1094 				}
1095 
1096 				/*
1097 				 * Locate and load the filtee.
1098 				 */
1099 				if ((nlmp = load_path(lml, lmco, ilmp, mode,
1100 				    FLG_RT_HANDLE, &ghp, &fd, &rej,
1101 				    in_nfavl)) == NULL)
1102 					file_notfound(LIST(ilmp), filtee, ilmp,
1103 					    FLG_RT_HANDLE, &rej);
1104 
1105 				filtee = pdp->pd_pname;
1106 
1107 				/*
1108 				 * Establish the filter handle to prevent any
1109 				 * recursion.
1110 				 */
1111 				if (nlmp && ghp) {
1112 					ghp->gh_flags |= GPH_FILTEE;
1113 					pdp->pd_info = (void *)ghp;
1114 
1115 					FLAGS1(nlmp) |= FL1_RT_USED;
1116 				}
1117 
1118 				/*
1119 				 * Audit the filter/filtee established.  A
1120 				 * return of 0 indicates the auditor wishes to
1121 				 * ignore this filtee.
1122 				 */
1123 				if (nlmp && ((lml->lm_tflags | FLAGS1(ilmp)) &
1124 				    LML_TFLG_AUD_OBJFILTER)) {
1125 					if (audit_objfilter(ilmp, filtees,
1126 					    nlmp, 0) == 0) {
1127 						audit = 1;
1128 						nlmp = 0;
1129 					}
1130 				}
1131 
1132 				/*
1133 				 * Finish processing the objects associated with
1134 				 * this request.  Create an association between
1135 				 * this object and the originating filter to
1136 				 * provide sufficient information to tear down
1137 				 * this filtee if necessary.
1138 				 */
1139 				if (nlmp && ghp && (((nlmp = analyze_lmc(lml,
1140 				    lmco, nlmp, in_nfavl)) == NULL) ||
1141 				    (relocate_lmc(lml, lmco, ilmp, nlmp,
1142 				    in_nfavl) == 0)))
1143 					nlmp = 0;
1144 
1145 				/*
1146 				 * If the filtee has been successfully
1147 				 * processed, then create an association
1148 				 * between the filter and filtee.  This
1149 				 * association provides sufficient information
1150 				 * to tear down the filter and filtee if
1151 				 * necessary.
1152 				 */
1153 				DBG_CALL(Dbg_file_hdl_title(DBG_HDL_ADD));
1154 				if (nlmp && ghp &&
1155 				    (hdl_add(ghp, ilmp, GPD_FILTER) == 0))
1156 					nlmp = 0;
1157 
1158 				/*
1159 				 * Generate a diagnostic if the filtee couldn't
1160 				 * be loaded.
1161 				 */
1162 				if (nlmp == 0)
1163 					DBG_CALL(Dbg_file_filtee(lml, 0, filtee,
1164 					    audit));
1165 
1166 				/*
1167 				 * If this filtee loading has failed, and we've
1168 				 * created a new link-map control list to which
1169 				 * this request has added objects, then remove
1170 				 * all the objects that have been associated to
1171 				 * this request.
1172 				 */
1173 				if ((nlmp == 0) && lmc && lmc->lc_head)
1174 					remove_lmc(lml, clmp, lmc, lmco, name);
1175 
1176 				/*
1177 				 * Remove any link-map control list that was
1178 				 * created.
1179 				 */
1180 				if (lmc)
1181 					remove_cntl(lml, lmco);
1182 			}
1183 
1184 			/*
1185 			 * If the filtee couldn't be loaded, null out the
1186 			 * path name descriptor entry, and continue the search.
1187 			 * Otherwise, the group handle is retained for future
1188 			 * symbol searches.
1189 			 */
1190 			if (nlmp == 0) {
1191 				pdp->pd_info = NULL;
1192 				pdp->pd_plen = 0;
1193 				continue;
1194 			}
1195 		}
1196 
1197 		ghp = (Grp_hdl *)pdp->pd_info;
1198 
1199 		/*
1200 		 * If we're just here to trigger filtee loading skip the symbol
1201 		 * lookup so we'll continue looking for additional filtees.
1202 		 */
1203 		if (name) {
1204 			Grp_desc	*gdp;
1205 			Sym		*sym = NULL;
1206 			Aliste		idx;
1207 			Slookup		sl = *slp;
1208 
1209 			sl.sl_flags |= LKUP_FIRST;
1210 			any++;
1211 
1212 			/*
1213 			 * Look for the symbol in the handles dependencies.
1214 			 */
1215 			for (ALIST_TRAVERSE(ghp->gh_depends, idx, gdp)) {
1216 				if ((gdp->gd_flags & GPD_DLSYM) == 0)
1217 					continue;
1218 
1219 				/*
1220 				 * If our parent is a dependency don't look at
1221 				 * it (otherwise we are in a recursive loop).
1222 				 * This situation can occur with auxiliary
1223 				 * filters if the filtee has a dependency on the
1224 				 * filter.  This dependency isn't necessary as
1225 				 * auxiliary filters are opened RTLD_PARENT, but
1226 				 * users may still unknowingly add an explicit
1227 				 * dependency to the parent.
1228 				 */
1229 				if ((sl.sl_imap = gdp->gd_depend) == ilmp)
1230 					continue;
1231 
1232 				if (((sym = SYMINTP(sl.sl_imap)(&sl, dlmp,
1233 				    binfo, in_nfavl)) != 0) ||
1234 				    (ghp->gh_flags & GPH_FIRST))
1235 					break;
1236 			}
1237 
1238 			/*
1239 			 * If a symbol has been found, indicate the binding
1240 			 * and return the symbol.
1241 			 */
1242 			if (sym) {
1243 				*binfo |= DBG_BINFO_FILTEE;
1244 				return (sym);
1245 			}
1246 		}
1247 
1248 		/*
1249 		 * If this object is tagged to terminate filtee processing we're
1250 		 * done.
1251 		 */
1252 		if (FLAGS1(ghp->gh_ownlmp) & FL1_RT_ENDFILTE)
1253 			break;
1254 	}
1255 
1256 	/*
1257 	 * If we're just here to trigger filtee loading then we're done.
1258 	 */
1259 	if (name == 0)
1260 		return (NULL);
1261 
1262 	/*
1263 	 * If no filtees have been found for a filter, clean up any path name
1264 	 * descriptors and disable their search completely.  For auxiliary
1265 	 * filters we can reselect the symbol search function so that we never
1266 	 * enter this routine again for this object.  For standard filters we
1267 	 * use the null symbol routine.
1268 	 */
1269 	if (any == 0) {
1270 		remove_plist((Alist **)&(dip->di_info), 1);
1271 		elf_disable_filtee(ilmp, dip);
1272 		return (NULL);
1273 	}
1274 
1275 	return (NULL);
1276 }
1277 
1278 /*
1279  * Focal point for disabling error messages for auxiliary filters.  As an
1280  * auxiliary filter allows for filtee use, but provides a fallback should a
1281  * filtee not exist (or fail to load), any errors generated as a consequence of
1282  * trying to load the filtees are typically suppressed.  Setting RT_FL_SILENCERR
1283  * suppresses errors generated by eprint(), but insures a debug diagnostic is
1284  * produced.  ldd(1) employs printf(), and here, the selection of whether to
1285  * print a diagnostic in regards to auxiliary filters is a little more complex.
1286  *
1287  *   .	The determination of whether to produce an ldd message, or a fatal
1288  *	error message is driven by LML_FLG_TRC_ENABLE.
1289  *   .	More detailed ldd messages may also be driven off of LML_FLG_TRC_WARN,
1290  *	(ldd -d/-r), LML_FLG_TRC_VERBOSE (ldd -v), LML_FLG_TRC_SEARCH (ldd -s),
1291  *	and LML_FLG_TRC_UNREF/LML_FLG_TRC_UNUSED (ldd -U/-u).
1292  *
1293  *   .	If the calling object is lddstub, then several classes of message are
1294  *	suppressed.  The user isn't trying to diagnose lddstub, this is simply
1295  *	a stub executable employed to preload a user specified library against.
1296  *
1297  *   .	If RT_FL_SILENCERR is in effect then any generic ldd() messages should
1298  *	be suppressed.  All detailed ldd messages should still be produced.
1299  */
1300 Sym *
1301 elf_lookup_filtee(Slookup *slp, Rt_map **dlmp, uint_t *binfo, uint_t ndx,
1302     int *in_nfavl)
1303 {
1304 	Sym	*sym;
1305 	Dyninfo	*dip = &DYNINFO(slp->sl_imap)[ndx];
1306 	int	silent = 0;
1307 
1308 	/*
1309 	 * Make sure this entry is still acting as a filter.  We may have tried
1310 	 * to process this previously, and disabled it if the filtee couldn't
1311 	 * be processed.  However, other entries may provide different filtees
1312 	 * that are yet to be completed.
1313 	 */
1314 	if (dip->di_flags == 0)
1315 		return (NULL);
1316 
1317 	/*
1318 	 * Indicate whether an error message is required should this filtee not
1319 	 * be found, based on the type of filter.
1320 	 */
1321 	if ((dip->di_flags & FLG_DI_AUXFLTR) &&
1322 	    ((rtld_flags & (RT_FL_WARNFLTR | RT_FL_SILENCERR)) == 0)) {
1323 		rtld_flags |= RT_FL_SILENCERR;
1324 		silent = 1;
1325 	}
1326 
1327 	sym = _elf_lookup_filtee(slp, dlmp, binfo, ndx, in_nfavl);
1328 
1329 	if (silent)
1330 		rtld_flags &= ~RT_FL_SILENCERR;
1331 
1332 	return (sym);
1333 }
1334 
1335 /*
1336  * Compute the elf hash value (as defined in the ELF access library).
1337  * The form of the hash table is:
1338  *
1339  *	|--------------|
1340  *	| # of buckets |
1341  *	|--------------|
1342  *	| # of chains  |
1343  *	|--------------|
1344  *	|   bucket[]   |
1345  *	|--------------|
1346  *	|   chain[]    |
1347  *	|--------------|
1348  */
1349 ulong_t
1350 elf_hash(const char *name)
1351 {
1352 	uint_t	hval = 0;
1353 
1354 	while (*name) {
1355 		uint_t	g;
1356 		hval = (hval << 4) + *name++;
1357 		if ((g = (hval & 0xf0000000)) != 0)
1358 			hval ^= g >> 24;
1359 		hval &= ~g;
1360 	}
1361 	return ((ulong_t)hval);
1362 }
1363 
1364 /*
1365  * If flag argument has LKUP_SPEC set, we treat undefined symbols of type
1366  * function specially in the executable - if they have a value, even though
1367  * undefined, we use that value.  This allows us to associate all references
1368  * to a function's address to a single place in the process: the plt entry
1369  * for that function in the executable.  Calls to lookup from plt binding
1370  * routines do NOT set LKUP_SPEC in the flag.
1371  */
1372 Sym *
1373 elf_find_sym(Slookup *slp, Rt_map **dlmp, uint_t *binfo, int *in_nfavl)
1374 {
1375 	const char	*name = slp->sl_name;
1376 	Rt_map		*ilmp = slp->sl_imap;
1377 	ulong_t		hash = slp->sl_hash;
1378 	uint_t		ndx, htmp, buckets, *chainptr;
1379 	Sym		*sym, *symtabptr;
1380 	char		*strtabptr, *strtabname;
1381 	uint_t		flags1;
1382 	Syminfo		*sip;
1383 
1384 	/*
1385 	 * If we're only here to establish a symbols index, skip the diagnostic
1386 	 * used to trace a symbol search.
1387 	 */
1388 	if ((slp->sl_flags & LKUP_SYMNDX) == 0)
1389 		DBG_CALL(Dbg_syms_lookup(ilmp, name, MSG_ORIG(MSG_STR_ELF)));
1390 
1391 	if (HASH(ilmp) == 0)
1392 		return (NULL);
1393 
1394 	buckets = HASH(ilmp)[0];
1395 	/* LINTED */
1396 	htmp = (uint_t)hash % buckets;
1397 
1398 	/*
1399 	 * Get the first symbol on hash chain and initialize the string
1400 	 * and symbol table pointers.
1401 	 */
1402 	if ((ndx = HASH(ilmp)[htmp + 2]) == 0)
1403 		return (NULL);
1404 
1405 	chainptr = HASH(ilmp) + 2 + buckets;
1406 	strtabptr = STRTAB(ilmp);
1407 	symtabptr = SYMTAB(ilmp);
1408 
1409 	while (ndx) {
1410 		sym = symtabptr + ndx;
1411 		strtabname = strtabptr + sym->st_name;
1412 
1413 		/*
1414 		 * Compare the symbol found with the name required.  If the
1415 		 * names don't match continue with the next hash entry.
1416 		 */
1417 		if ((*strtabname++ != *name) || strcmp(strtabname, &name[1])) {
1418 			if ((ndx = chainptr[ndx]) != 0)
1419 				continue;
1420 			return (NULL);
1421 		}
1422 
1423 		/*
1424 		 * The Solaris ld does not put DT_VERSYM in the dynamic
1425 		 * section, but the GNU ld does. The GNU runtime linker
1426 		 * interprets the top bit of the 16-bit Versym value
1427 		 * (0x8000) as the "hidden" bit. If this bit is set,
1428 		 * the linker is supposed to act as if that symbol does
1429 		 * not exist. The hidden bit supports their versioning
1430 		 * scheme, which allows multiple incompatible functions
1431 		 * with the same name to exist at different versions
1432 		 * within an object. The Solaris linker does not support this
1433 		 * mechanism, or the model of interface evolution that
1434 		 * it allows, but we honor the hidden bit in GNU ld
1435 		 * produced objects in order to interoperate with them.
1436 		 */
1437 		if ((VERSYM(ilmp) != NULL) &&
1438 		    ((VERSYM(ilmp)[ndx] & 0x8000) != 0)) {
1439 			DBG_CALL(Dbg_syms_ignore_gnuver(ilmp, name,
1440 			    ndx, VERSYM(ilmp)[ndx]));
1441 			if ((ndx = chainptr[ndx]) != 0)
1442 				continue;
1443 			return (NULL);
1444 		}
1445 
1446 		/*
1447 		 * If we're only here to establish a symbols index, we're done.
1448 		 */
1449 		if (slp->sl_flags & LKUP_SYMNDX)
1450 			return (sym);
1451 
1452 		/*
1453 		 * If we find a match and the symbol is defined, return the
1454 		 * symbol pointer and the link map in which it was found.
1455 		 */
1456 		if (sym->st_shndx != SHN_UNDEF) {
1457 			*dlmp = ilmp;
1458 			*binfo |= DBG_BINFO_FOUND;
1459 			if ((FLAGS(ilmp) & FLG_RT_OBJINTPO) ||
1460 			    ((FLAGS(ilmp) & FLG_RT_SYMINTPO) &&
1461 			    is_sym_interposer(ilmp, sym)))
1462 				*binfo |= DBG_BINFO_INTERPOSE;
1463 			break;
1464 
1465 		/*
1466 		 * If we find a match and the symbol is undefined, the
1467 		 * symbol type is a function, and the value of the symbol
1468 		 * is non zero, then this is a special case.  This allows
1469 		 * the resolution of a function address to the plt[] entry.
1470 		 * See SPARC ABI, Dynamic Linking, Function Addresses for
1471 		 * more details.
1472 		 */
1473 		} else if ((slp->sl_flags & LKUP_SPEC) &&
1474 		    (FLAGS(ilmp) & FLG_RT_ISMAIN) && (sym->st_value != 0) &&
1475 		    (ELF_ST_TYPE(sym->st_info) == STT_FUNC)) {
1476 			*dlmp = ilmp;
1477 			*binfo |= (DBG_BINFO_FOUND | DBG_BINFO_PLTADDR);
1478 			if ((FLAGS(ilmp) & FLG_RT_OBJINTPO) ||
1479 			    ((FLAGS(ilmp) & FLG_RT_SYMINTPO) &&
1480 			    is_sym_interposer(ilmp, sym)))
1481 				*binfo |= DBG_BINFO_INTERPOSE;
1482 			return (sym);
1483 		}
1484 
1485 		/*
1486 		 * Undefined symbol.
1487 		 */
1488 		return (NULL);
1489 	}
1490 
1491 	/*
1492 	 * We've found a match.  Determine if the defining object contains
1493 	 * symbol binding information.
1494 	 */
1495 	if ((sip = SYMINFO(ilmp)) != 0)
1496 		sip += ndx;
1497 
1498 	/*
1499 	 * If this definition is a singleton, and we haven't followed a default
1500 	 * symbol search knowing that we're looking for a singleton (presumably
1501 	 * because the symbol definition has been changed since the referring
1502 	 * object was built), then reject this binding so that the caller can
1503 	 * fall back to a standard symbol search.
1504 	 */
1505 	if ((ELF_ST_VISIBILITY(sym->st_other) == STV_SINGLETON) &&
1506 	    (((slp->sl_flags & LKUP_STANDARD) == 0) ||
1507 	    (((slp->sl_flags & LKUP_SINGLETON) == 0) &&
1508 	    (LIST(ilmp)->lm_flags & LML_FLG_GROUPSEXIST)))) {
1509 		DBG_CALL(Dbg_bind_reject(slp->sl_cmap, ilmp, name,
1510 		    DBG_BNDREJ_SINGLE));
1511 		*binfo |= BINFO_REJSINGLE;
1512 		*binfo &= ~DBG_BINFO_MSK;
1513 		return (NULL);
1514 	}
1515 
1516 	/*
1517 	 * If this is a direct binding request, but the symbol definition has
1518 	 * disabled directly binding to it (presumably because the symbol
1519 	 * definition has been changed since the referring object was built),
1520 	 * reject this binding so that the caller can fall back to a standard
1521 	 * symbol search.
1522 	 */
1523 	if (sip && (slp->sl_flags & LKUP_DIRECT) &&
1524 	    (sip->si_flags & SYMINFO_FLG_NOEXTDIRECT)) {
1525 		DBG_CALL(Dbg_bind_reject(slp->sl_cmap, ilmp, name,
1526 		    DBG_BNDREJ_DIRECT));
1527 		*binfo |= BINFO_REJDIRECT;
1528 		*binfo &= ~DBG_BINFO_MSK;
1529 		return (NULL);
1530 	}
1531 
1532 	/*
1533 	 * If this is a binding request within an RTLD_GROUP family, and the
1534 	 * symbol has disabled directly binding to it, reject this binding so
1535 	 * that the caller can fall back to a standard symbol search.
1536 	 *
1537 	 * Effectively, an RTLD_GROUP family achieves what can now be
1538 	 * established with direct bindings.  However, various symbols have
1539 	 * been tagged as inappropriate for direct binding to (ie. libc:malloc).
1540 	 *
1541 	 * A symbol marked as no-direct cannot be used within a group without
1542 	 * first ensuring that the symbol has not been interposed upon outside
1543 	 * of the group.  A common example occurs when users implement their own
1544 	 * version of malloc() in the executable.  Such a malloc() interposes on
1545 	 * the libc:malloc, and this interposition must be honored within the
1546 	 * group as well.
1547 	 *
1548 	 * Following any rejection, LKUP_WORLD is established as a means of
1549 	 * overriding this test as we return to a standard search.
1550 	 */
1551 	if (sip && (sip->si_flags & SYMINFO_FLG_NOEXTDIRECT) &&
1552 	    ((MODE(slp->sl_cmap) & (RTLD_GROUP | RTLD_WORLD)) == RTLD_GROUP) &&
1553 	    ((slp->sl_flags & LKUP_WORLD) == 0)) {
1554 		DBG_CALL(Dbg_bind_reject(slp->sl_cmap, ilmp, name,
1555 		    DBG_BNDREJ_GROUP));
1556 		*binfo |= BINFO_REJGROUP;
1557 		*binfo &= ~DBG_BINFO_MSK;
1558 		return (NULL);
1559 	}
1560 
1561 	/*
1562 	 * Determine whether this object is acting as a filter.
1563 	 */
1564 	if (((flags1 = FLAGS1(ilmp)) & MSK_RT_FILTER) == 0)
1565 		return (sym);
1566 
1567 	/*
1568 	 * Determine if this object offers per-symbol filtering, and if so,
1569 	 * whether this symbol references a filtee.
1570 	 */
1571 	if (sip && (flags1 & (FL1_RT_SYMSFLTR | FL1_RT_SYMAFLTR))) {
1572 		/*
1573 		 * If this is a standard filter reference, and no standard
1574 		 * filtees remain to be inspected, we're done.  If this is an
1575 		 * auxiliary filter reference, and no auxiliary filtees remain,
1576 		 * we'll fall through in case any object filtering is available.
1577 		 */
1578 		if ((sip->si_flags & SYMINFO_FLG_FILTER) &&
1579 		    (SYMSFLTRCNT(ilmp) == 0))
1580 			return (NULL);
1581 
1582 		if ((sip->si_flags & SYMINFO_FLG_FILTER) ||
1583 		    ((sip->si_flags & SYMINFO_FLG_AUXILIARY) &&
1584 		    SYMAFLTRCNT(ilmp))) {
1585 			Sym	*fsym;
1586 
1587 			/*
1588 			 * This symbol has an associated filtee.  Lookup the
1589 			 * symbol in the filtee, and if it is found return it.
1590 			 * If the symbol doesn't exist, and this is a standard
1591 			 * filter, return an error, otherwise fall through to
1592 			 * catch any object filtering that may be available.
1593 			 */
1594 			if ((fsym = elf_lookup_filtee(slp, dlmp, binfo,
1595 			    sip->si_boundto, in_nfavl)) != 0)
1596 				return (fsym);
1597 			if (sip->si_flags & SYMINFO_FLG_FILTER)
1598 				return (NULL);
1599 		}
1600 	}
1601 
1602 	/*
1603 	 * Determine if this object provides global filtering.
1604 	 */
1605 	if (flags1 & (FL1_RT_OBJSFLTR | FL1_RT_OBJAFLTR)) {
1606 		Sym	*fsym;
1607 
1608 		if (OBJFLTRNDX(ilmp) != FLTR_DISABLED) {
1609 			/*
1610 			 * This object has an associated filtee.  Lookup the
1611 			 * symbol in the filtee, and if it is found return it.
1612 			 * If the symbol doesn't exist, and this is a standard
1613 			 * filter, return and error, otherwise return the symbol
1614 			 * within the filter itself.
1615 			 */
1616 			if ((fsym = elf_lookup_filtee(slp, dlmp, binfo,
1617 			    OBJFLTRNDX(ilmp), in_nfavl)) != 0)
1618 				return (fsym);
1619 		}
1620 
1621 		if (flags1 & FL1_RT_OBJSFLTR)
1622 			return (NULL);
1623 	}
1624 	return (sym);
1625 }
1626 
1627 /*
1628  * Create a new Rt_map structure for an ELF object and initialize
1629  * all values.
1630  */
1631 Rt_map *
1632 elf_new_lmp(Lm_list *lml, Aliste lmco, Fdesc *fdp, Addr addr, size_t msize,
1633     void *odyn, int *in_nfavl)
1634 {
1635 	const char	*name = fdp->fd_nname;
1636 	Rt_map		*lmp;
1637 	Ehdr		*ehdr = (Ehdr *)addr;
1638 	Phdr		*phdr, *tphdr = NULL, *dphdr = NULL, *uphdr = NULL;
1639 	Dyn		*dyn = (Dyn *)odyn;
1640 	Cap		*cap = NULL;
1641 	int		ndx;
1642 	Addr		base, fltr = 0, audit = 0, cfile = 0, crle = 0;
1643 	Xword		rpath = 0;
1644 	size_t		lmsz, rtsz, epsz, dynsz = 0;
1645 	uint_t		dyncnt = 0;
1646 
1647 	DBG_CALL(Dbg_file_elf(lml, name, addr, msize, lml->lm_lmidstr, lmco));
1648 
1649 	/*
1650 	 * If this is a shared object, the base address of the shared object is
1651 	 * added to all address values defined within the object.  Otherwise, if
1652 	 * this is an executable, all object addresses are used as is.
1653 	 */
1654 	if (ehdr->e_type == ET_EXEC)
1655 		base = 0;
1656 	else
1657 		base = addr;
1658 
1659 	/*
1660 	 * Traverse the program header table, picking off required items.  This
1661 	 * traversal also provides for the sizing of the PT_DYNAMIC section.
1662 	 */
1663 	phdr = (Phdr *)((uintptr_t)ehdr + ehdr->e_phoff);
1664 	for (ndx = 0; ndx < (int)ehdr->e_phnum; ndx++,
1665 	    phdr = (Phdr *)((uintptr_t)phdr + ehdr->e_phentsize)) {
1666 		switch (phdr->p_type) {
1667 		case PT_DYNAMIC:
1668 			dphdr = phdr;
1669 			dyn = (Dyn *)((uintptr_t)phdr->p_vaddr + base);
1670 			break;
1671 		case PT_TLS:
1672 			tphdr = phdr;
1673 			break;
1674 		case PT_SUNWCAP:
1675 			cap = (Cap *)((uintptr_t)phdr->p_vaddr + base);
1676 			break;
1677 		case PT_SUNW_UNWIND:
1678 			uphdr = phdr;
1679 			break;
1680 		default:
1681 			break;
1682 		}
1683 	}
1684 
1685 	/*
1686 	 * Determine the number of PT_DYNAMIC entries for the DYNINFO()
1687 	 * allocation.  Sadly, this is a little larger than we really need,
1688 	 * as there are typically padding DT_NULL entries.  However, adding
1689 	 * this data to the initial link-map allocation is a win.
1690 	 */
1691 	if (dyn) {
1692 		dyncnt = dphdr->p_filesz / sizeof (Dyn);
1693 		dynsz = dyncnt * sizeof (Dyninfo);
1694 	}
1695 
1696 	/*
1697 	 * Allocate space for the link-map, private elf information, and
1698 	 * DYNINFO() data.  Once these are allocated and initialized,
1699 	 * remove_so(0, lmp) can be used to tear down the link-map allocation
1700 	 * should any failures occur.
1701 	 */
1702 	rtsz = S_DROUND(sizeof (Rt_map));
1703 	epsz = S_DROUND(sizeof (Rt_elfp));
1704 	lmsz = rtsz + epsz + dynsz;
1705 	if ((lmp = calloc(lmsz, 1)) == NULL)
1706 		return (NULL);
1707 	ELFPRV(lmp) = (void *)((uintptr_t)lmp + rtsz);
1708 	DYNINFO(lmp) = (Dyninfo *)((uintptr_t)lmp + rtsz + epsz);
1709 	LMSIZE(lmp) = lmsz;
1710 
1711 	/*
1712 	 * All fields not filled in were set to 0 by calloc.
1713 	 */
1714 	NAME(lmp) = (char *)name;
1715 	ADDR(lmp) = addr;
1716 	MSIZE(lmp) = msize;
1717 	SYMINTP(lmp) = elf_find_sym;
1718 	FCT(lmp) = &elf_fct;
1719 	LIST(lmp) = lml;
1720 	OBJFLTRNDX(lmp) = FLTR_DISABLED;
1721 	SORTVAL(lmp) = -1;
1722 	DYN(lmp) = dyn;
1723 	DYNINFOCNT(lmp) = dyncnt;
1724 	PTUNWIND(lmp) = uphdr;
1725 
1726 	if (ehdr->e_type == ET_EXEC)
1727 		FLAGS(lmp) |= FLG_RT_FIXED;
1728 
1729 	/*
1730 	 * Fill in rest of the link map entries with information from the file's
1731 	 * dynamic structure.
1732 	 */
1733 	if (dyn) {
1734 		uint_t		dynndx = 0;
1735 		Xword		pltpadsz = 0;
1736 		Rti_desc	*rti;
1737 
1738 		/* CSTYLED */
1739 		for ( ; dyn->d_tag != DT_NULL; ++dyn, dynndx++) {
1740 			switch ((Xword)dyn->d_tag) {
1741 			case DT_SYMTAB:
1742 				SYMTAB(lmp) = (void *)(dyn->d_un.d_ptr + base);
1743 				break;
1744 			case DT_SUNW_SYMTAB:
1745 				SUNWSYMTAB(lmp) =
1746 				    (void *)(dyn->d_un.d_ptr + base);
1747 				break;
1748 			case DT_SUNW_SYMSZ:
1749 				SUNWSYMSZ(lmp) = dyn->d_un.d_val;
1750 				break;
1751 			case DT_STRTAB:
1752 				STRTAB(lmp) = (void *)(dyn->d_un.d_ptr + base);
1753 				break;
1754 			case DT_SYMENT:
1755 				SYMENT(lmp) = dyn->d_un.d_val;
1756 				break;
1757 			case DT_FEATURE_1:
1758 				dyn->d_un.d_val |= DTF_1_PARINIT;
1759 				if (dyn->d_un.d_val & DTF_1_CONFEXP)
1760 					crle = 1;
1761 				break;
1762 			case DT_MOVESZ:
1763 				MOVESZ(lmp) = dyn->d_un.d_val;
1764 				FLAGS(lmp) |= FLG_RT_MOVE;
1765 				break;
1766 			case DT_MOVEENT:
1767 				MOVEENT(lmp) = dyn->d_un.d_val;
1768 				break;
1769 			case DT_MOVETAB:
1770 				MOVETAB(lmp) = (void *)(dyn->d_un.d_ptr + base);
1771 				break;
1772 			case DT_REL:
1773 			case DT_RELA:
1774 				/*
1775 				 * At this time, ld.so. can only handle one
1776 				 * type of relocation per object.
1777 				 */
1778 				REL(lmp) = (void *)(dyn->d_un.d_ptr + base);
1779 				break;
1780 			case DT_RELSZ:
1781 			case DT_RELASZ:
1782 				RELSZ(lmp) = dyn->d_un.d_val;
1783 				break;
1784 			case DT_RELENT:
1785 			case DT_RELAENT:
1786 				RELENT(lmp) = dyn->d_un.d_val;
1787 				break;
1788 			case DT_RELCOUNT:
1789 			case DT_RELACOUNT:
1790 				RELACOUNT(lmp) = (uint_t)dyn->d_un.d_val;
1791 				break;
1792 			case DT_HASH:
1793 				HASH(lmp) = (uint_t *)(dyn->d_un.d_ptr + base);
1794 				break;
1795 			case DT_PLTGOT:
1796 				PLTGOT(lmp) =
1797 				    (uint_t *)(dyn->d_un.d_ptr + base);
1798 				break;
1799 			case DT_PLTRELSZ:
1800 				PLTRELSZ(lmp) = dyn->d_un.d_val;
1801 				break;
1802 			case DT_JMPREL:
1803 				JMPREL(lmp) = (void *)(dyn->d_un.d_ptr + base);
1804 				break;
1805 			case DT_INIT:
1806 				if (dyn->d_un.d_ptr != NULL)
1807 					INIT(lmp) =
1808 					    (void (*)())(dyn->d_un.d_ptr +
1809 					    base);
1810 				break;
1811 			case DT_FINI:
1812 				if (dyn->d_un.d_ptr != NULL)
1813 					FINI(lmp) =
1814 					    (void (*)())(dyn->d_un.d_ptr +
1815 					    base);
1816 				break;
1817 			case DT_INIT_ARRAY:
1818 				INITARRAY(lmp) = (Addr *)(dyn->d_un.d_ptr +
1819 				    base);
1820 				break;
1821 			case DT_INIT_ARRAYSZ:
1822 				INITARRAYSZ(lmp) = (uint_t)dyn->d_un.d_val;
1823 				break;
1824 			case DT_FINI_ARRAY:
1825 				FINIARRAY(lmp) = (Addr *)(dyn->d_un.d_ptr +
1826 				    base);
1827 				break;
1828 			case DT_FINI_ARRAYSZ:
1829 				FINIARRAYSZ(lmp) = (uint_t)dyn->d_un.d_val;
1830 				break;
1831 			case DT_PREINIT_ARRAY:
1832 				PREINITARRAY(lmp) = (Addr *)(dyn->d_un.d_ptr +
1833 				    base);
1834 				break;
1835 			case DT_PREINIT_ARRAYSZ:
1836 				PREINITARRAYSZ(lmp) = (uint_t)dyn->d_un.d_val;
1837 				break;
1838 			case DT_RPATH:
1839 			case DT_RUNPATH:
1840 				rpath = dyn->d_un.d_val;
1841 				break;
1842 			case DT_FILTER:
1843 				fltr = dyn->d_un.d_val;
1844 				OBJFLTRNDX(lmp) = dynndx;
1845 				FLAGS1(lmp) |= FL1_RT_OBJSFLTR;
1846 				break;
1847 			case DT_AUXILIARY:
1848 				if (!(rtld_flags & RT_FL_NOAUXFLTR)) {
1849 					fltr = dyn->d_un.d_val;
1850 					OBJFLTRNDX(lmp) = dynndx;
1851 				}
1852 				FLAGS1(lmp) |= FL1_RT_OBJAFLTR;
1853 				break;
1854 			case DT_SUNW_FILTER:
1855 				SYMSFLTRCNT(lmp)++;
1856 				FLAGS1(lmp) |= FL1_RT_SYMSFLTR;
1857 				break;
1858 			case DT_SUNW_AUXILIARY:
1859 				if (!(rtld_flags & RT_FL_NOAUXFLTR)) {
1860 					SYMAFLTRCNT(lmp)++;
1861 				}
1862 				FLAGS1(lmp) |= FL1_RT_SYMAFLTR;
1863 				break;
1864 			case DT_DEPAUDIT:
1865 				if (!(rtld_flags & RT_FL_NOAUDIT))
1866 					audit = dyn->d_un.d_val;
1867 				break;
1868 			case DT_CONFIG:
1869 				cfile = dyn->d_un.d_val;
1870 				break;
1871 			case DT_DEBUG:
1872 				/*
1873 				 * DT_DEBUG entries are only created in
1874 				 * dynamic objects that require an interpretor
1875 				 * (ie. all dynamic executables and some shared
1876 				 * objects), and provide for a hand-shake with
1877 				 * debuggers.  This entry is initialized to
1878 				 * zero by the link-editor.  If a debugger has
1879 				 * us and updated this entry set the debugger
1880 				 * flag, and finish initializing the debugging
1881 				 * structure (see setup() also).  Switch off any
1882 				 * configuration object use as most debuggers
1883 				 * can't handle fixed dynamic executables as
1884 				 * dependencies, and we can't handle requests
1885 				 * like object padding for alternative objects.
1886 				 */
1887 				if (dyn->d_un.d_ptr)
1888 					rtld_flags |=
1889 					    (RT_FL_DEBUGGER | RT_FL_NOOBJALT);
1890 				dyn->d_un.d_ptr = (Addr)&r_debug;
1891 				break;
1892 			case DT_VERNEED:
1893 				VERNEED(lmp) = (Verneed *)(dyn->d_un.d_ptr +
1894 				    base);
1895 				break;
1896 			case DT_VERNEEDNUM:
1897 				/* LINTED */
1898 				VERNEEDNUM(lmp) = (int)dyn->d_un.d_val;
1899 				break;
1900 			case DT_VERDEF:
1901 				VERDEF(lmp) = (Verdef *)(dyn->d_un.d_ptr +
1902 				    base);
1903 				break;
1904 			case DT_VERDEFNUM:
1905 				/* LINTED */
1906 				VERDEFNUM(lmp) = (int)dyn->d_un.d_val;
1907 				break;
1908 			case DT_VERSYM:
1909 				/*
1910 				 * The Solaris ld does not produce DT_VERSYM,
1911 				 * but the GNU ld does, in order to support
1912 				 * their style of versioning, which differs
1913 				 * from ours in some ways, while using the
1914 				 * same data structures. The presence of
1915 				 * DT_VERSYM therefore means that GNU
1916 				 * versioning rules apply to the given file.
1917 				 * If DT_VERSYM is not present, then Solaris
1918 				 * versioning rules apply.
1919 				 */
1920 				VERSYM(lmp) = (Versym *)(dyn->d_un.d_ptr +
1921 				    base);
1922 				break;
1923 			case DT_BIND_NOW:
1924 				if ((dyn->d_un.d_val & DF_BIND_NOW) &&
1925 				    ((rtld_flags2 & RT_FL2_BINDLAZY) == 0)) {
1926 					MODE(lmp) |= RTLD_NOW;
1927 					MODE(lmp) &= ~RTLD_LAZY;
1928 				}
1929 				break;
1930 			case DT_FLAGS:
1931 				FLAGS1(lmp) |= FL1_RT_DTFLAGS;
1932 				if (dyn->d_un.d_val & DF_SYMBOLIC)
1933 					FLAGS1(lmp) |= FL1_RT_SYMBOLIC;
1934 				if ((dyn->d_un.d_val & DF_BIND_NOW) &&
1935 				    ((rtld_flags2 & RT_FL2_BINDLAZY) == 0)) {
1936 					MODE(lmp) |= RTLD_NOW;
1937 					MODE(lmp) &= ~RTLD_LAZY;
1938 				}
1939 				/*
1940 				 * Capture any static TLS use, and enforce that
1941 				 * this object be non-deletable.
1942 				 */
1943 				if (dyn->d_un.d_val & DF_STATIC_TLS) {
1944 					FLAGS1(lmp) |= FL1_RT_TLSSTAT;
1945 					MODE(lmp) |= RTLD_NODELETE;
1946 				}
1947 				break;
1948 			case DT_FLAGS_1:
1949 				if (dyn->d_un.d_val & DF_1_DISPRELPND)
1950 					FLAGS1(lmp) |= FL1_RT_DISPREL;
1951 				if (dyn->d_un.d_val & DF_1_GROUP)
1952 					FLAGS(lmp) |=
1953 					    (FLG_RT_SETGROUP | FLG_RT_HANDLE);
1954 				if ((dyn->d_un.d_val & DF_1_NOW) &&
1955 				    ((rtld_flags2 & RT_FL2_BINDLAZY) == 0)) {
1956 					MODE(lmp) |= RTLD_NOW;
1957 					MODE(lmp) &= ~RTLD_LAZY;
1958 				}
1959 				if (dyn->d_un.d_val & DF_1_NODELETE)
1960 					MODE(lmp) |= RTLD_NODELETE;
1961 				if (dyn->d_un.d_val & DF_1_INITFIRST)
1962 					FLAGS(lmp) |= FLG_RT_INITFRST;
1963 				if (dyn->d_un.d_val & DF_1_NOOPEN)
1964 					FLAGS(lmp) |= FLG_RT_NOOPEN;
1965 				if (dyn->d_un.d_val & DF_1_LOADFLTR)
1966 					FLAGS(lmp) |= FLG_RT_LOADFLTR;
1967 				if (dyn->d_un.d_val & DF_1_NODUMP)
1968 					FLAGS(lmp) |= FLG_RT_NODUMP;
1969 				if (dyn->d_un.d_val & DF_1_CONFALT)
1970 					crle = 1;
1971 				if (dyn->d_un.d_val & DF_1_DIRECT)
1972 					FLAGS1(lmp) |= FL1_RT_DIRECT;
1973 				if (dyn->d_un.d_val & DF_1_NODEFLIB)
1974 					FLAGS1(lmp) |= FL1_RT_NODEFLIB;
1975 				if (dyn->d_un.d_val & DF_1_ENDFILTEE)
1976 					FLAGS1(lmp) |= FL1_RT_ENDFILTE;
1977 				if (dyn->d_un.d_val & DF_1_TRANS)
1978 					FLAGS(lmp) |= FLG_RT_TRANS;
1979 
1980 				/*
1981 				 * Global auditing is only meaningful when
1982 				 * specified by the initiating object of the
1983 				 * process - typically the dynamic executable.
1984 				 * If this is the initiaiting object, its link-
1985 				 * map will not yet have been added to the
1986 				 * link-map list, and consequently the link-map
1987 				 * list is empty.  (see setup()).
1988 				 */
1989 				if (dyn->d_un.d_val & DF_1_GLOBAUDIT) {
1990 					if (lml_main.lm_head == 0)
1991 						FLAGS1(lmp) |= FL1_RT_GLOBAUD;
1992 					else
1993 						DBG_CALL(Dbg_audit_ignore(lmp));
1994 				}
1995 
1996 				/*
1997 				 * If this object identifies itself as an
1998 				 * interposer, but relocation processing has
1999 				 * already started, then demote it.  It's too
2000 				 * late to guarantee complete interposition.
2001 				 */
2002 				/* BEGIN CSTYLED */
2003 				if (dyn->d_un.d_val &
2004 				    (DF_1_INTERPOSE | DF_1_SYMINTPOSE)) {
2005 				    if (lml->lm_flags & LML_FLG_STARTREL) {
2006 					DBG_CALL(Dbg_util_intoolate(lmp));
2007 					if (lml->lm_flags & LML_FLG_TRC_ENABLE)
2008 					    (void) printf(
2009 						MSG_INTL(MSG_LDD_REL_ERR2),
2010 						NAME(lmp));
2011 				    } else if (dyn->d_un.d_val & DF_1_INTERPOSE)
2012 					FLAGS(lmp) |= FLG_RT_OBJINTPO;
2013 				    else
2014 					FLAGS(lmp) |= FLG_RT_SYMINTPO;
2015 				}
2016 				/* END CSTYLED */
2017 				break;
2018 			case DT_SYMINFO:
2019 				SYMINFO(lmp) = (Syminfo *)(dyn->d_un.d_ptr +
2020 				    base);
2021 				break;
2022 			case DT_SYMINENT:
2023 				SYMINENT(lmp) = dyn->d_un.d_val;
2024 				break;
2025 			case DT_PLTPAD:
2026 				PLTPAD(lmp) = (void *)(dyn->d_un.d_ptr + base);
2027 				break;
2028 			case DT_PLTPADSZ:
2029 				pltpadsz = dyn->d_un.d_val;
2030 				break;
2031 			case DT_SUNW_RTLDINF:
2032 				/*
2033 				 * Maintain a list of RTLDINFO structures.
2034 				 * Typically, libc is the only supplier, and
2035 				 * only one structure is provided.  However,
2036 				 * multiple suppliers and multiple structures
2037 				 * are supported.  For example, one structure
2038 				 * may provide thread_init, and another
2039 				 * structure may provide atexit reservations.
2040 				 */
2041 				if ((rti = alist_append(&lml->lm_rti, 0,
2042 				    sizeof (Rti_desc),
2043 				    AL_CNT_RTLDINFO)) == NULL) {
2044 					remove_so(0, lmp);
2045 					return (NULL);
2046 				}
2047 				rti->rti_lmp = lmp;
2048 				rti->rti_info = (void *)(dyn->d_un.d_ptr +
2049 				    base);
2050 				break;
2051 			case DT_SUNW_SORTENT:
2052 				SUNWSORTENT(lmp) = dyn->d_un.d_val;
2053 				break;
2054 			case DT_SUNW_SYMSORT:
2055 				SUNWSYMSORT(lmp) =
2056 				    (void *)(dyn->d_un.d_ptr + base);
2057 				break;
2058 			case DT_SUNW_SYMSORTSZ:
2059 				SUNWSYMSORTSZ(lmp) = dyn->d_un.d_val;
2060 				break;
2061 			case DT_DEPRECATED_SPARC_REGISTER:
2062 			case M_DT_REGISTER:
2063 				FLAGS(lmp) |= FLG_RT_REGSYMS;
2064 				break;
2065 			}
2066 		}
2067 
2068 		if (PLTPAD(lmp)) {
2069 			if (pltpadsz == (Xword)0)
2070 				PLTPAD(lmp) = 0;
2071 			else
2072 				PLTPADEND(lmp) = (void *)((Addr)PLTPAD(lmp) +
2073 				    pltpadsz);
2074 		}
2075 	}
2076 
2077 	/*
2078 	 * A dynsym contains only global functions. We want to have
2079 	 * a version of it that also includes local functions, so that
2080 	 * dladdr() will be able to report names for local functions
2081 	 * when used to generate a stack trace for a stripped file.
2082 	 * This version of the dynsym is provided via DT_SUNW_SYMTAB.
2083 	 *
2084 	 * In producing DT_SUNW_SYMTAB, ld uses a non-obvious trick
2085 	 * in order to avoid having to have two copies of the global
2086 	 * symbols held in DT_SYMTAB: The local symbols are placed in
2087 	 * a separate section than the globals in the dynsym, but the
2088 	 * linker conspires to put the data for these two sections adjacent
2089 	 * to each other. DT_SUNW_SYMTAB points at the top of the local
2090 	 * symbols, and DT_SUNW_SYMSZ is the combined length of both tables.
2091 	 *
2092 	 * If the two sections are not adjacent, then something went wrong
2093 	 * at link time. We use ASSERT to kill the process if this is
2094 	 * a debug build. In a production build, we will silently ignore
2095 	 * the presence of the .ldynsym and proceed. We can detect this
2096 	 * situation by checking to see that DT_SYMTAB lies in
2097 	 * the range given by DT_SUNW_SYMTAB/DT_SUNW_SYMSZ.
2098 	 */
2099 	if ((SUNWSYMTAB(lmp) != NULL) &&
2100 	    (((char *)SYMTAB(lmp) <= (char *)SUNWSYMTAB(lmp)) ||
2101 	    (((char *)SYMTAB(lmp) >=
2102 	    (SUNWSYMSZ(lmp) + (char *)SUNWSYMTAB(lmp)))))) {
2103 		ASSERT(0);
2104 		SUNWSYMTAB(lmp) = NULL;
2105 		SUNWSYMSZ(lmp) = 0;
2106 	}
2107 
2108 	/*
2109 	 * If configuration file use hasn't been disabled, and a configuration
2110 	 * file hasn't already been set via an environment variable, see if any
2111 	 * application specific configuration file is specified.  An LD_CONFIG
2112 	 * setting is used first, but if this image was generated via crle(1)
2113 	 * then a default configuration file is a fall-back.
2114 	 */
2115 	if ((!(rtld_flags & RT_FL_NOCFG)) && (config->c_name == 0)) {
2116 		if (cfile)
2117 			config->c_name = (const char *)(cfile +
2118 			    (char *)STRTAB(lmp));
2119 		else if (crle)
2120 			rtld_flags |= RT_FL_CONFAPP;
2121 	}
2122 
2123 	if (rpath)
2124 		RPATH(lmp) = (char *)(rpath + (char *)STRTAB(lmp));
2125 	if (fltr)
2126 		REFNAME(lmp) = (char *)(fltr + (char *)STRTAB(lmp));
2127 
2128 	/*
2129 	 * For Intel ABI compatibility.  It's possible that a JMPREL can be
2130 	 * specified without any other relocations (e.g. a dynamic executable
2131 	 * normally only contains .plt relocations).  If this is the case then
2132 	 * no REL, RELSZ or RELENT will have been created.  For us to be able
2133 	 * to traverse the .plt relocations under LD_BIND_NOW we need to know
2134 	 * the RELENT for these relocations.  Refer to elf_reloc() for more
2135 	 * details.
2136 	 */
2137 	if (!RELENT(lmp) && JMPREL(lmp))
2138 		RELENT(lmp) = sizeof (M_RELOC);
2139 
2140 	/*
2141 	 * Establish any per-object auditing.  If we're establishing `main's
2142 	 * link-map its too early to go searching for audit objects so just
2143 	 * hold the object name for later (see setup()).
2144 	 */
2145 	if (audit) {
2146 		char	*cp = audit + (char *)STRTAB(lmp);
2147 
2148 		if (*cp) {
2149 			if (((AUDITORS(lmp) =
2150 			    calloc(1, sizeof (Audit_desc))) == NULL) ||
2151 			    ((AUDITORS(lmp)->ad_name = strdup(cp)) == NULL)) {
2152 				remove_so(0, lmp);
2153 				return (NULL);
2154 			}
2155 			if (lml_main.lm_head) {
2156 				if (audit_setup(lmp, AUDITORS(lmp), 0,
2157 				    in_nfavl) == 0) {
2158 					remove_so(0, lmp);
2159 					return (NULL);
2160 				}
2161 				AFLAGS(lmp) |= AUDITORS(lmp)->ad_flags;
2162 				lml->lm_flags |= LML_FLG_LOCAUDIT;
2163 			}
2164 		}
2165 	}
2166 
2167 	if (tphdr && (tls_assign(lml, lmp, tphdr) == 0)) {
2168 		remove_so(0, lmp);
2169 		return (NULL);
2170 	}
2171 
2172 	if (cap)
2173 		cap_assign(cap, lmp);
2174 
2175 	/*
2176 	 * Add the mapped object to the end of the link map list.
2177 	 */
2178 	lm_append(lml, lmco, lmp);
2179 
2180 	/*
2181 	 * Start the system loading in the ELF information we'll be processing.
2182 	 */
2183 	if (REL(lmp)) {
2184 		(void) madvise((void *)ADDR(lmp), (uintptr_t)REL(lmp) +
2185 		    (uintptr_t)RELSZ(lmp) - (uintptr_t)ADDR(lmp),
2186 		    MADV_WILLNEED);
2187 	}
2188 	return (lmp);
2189 }
2190 
2191 /*
2192  * Assign hardware/software capabilities.
2193  */
2194 void
2195 cap_assign(Cap *cap, Rt_map *lmp)
2196 {
2197 	while (cap->c_tag != CA_SUNW_NULL) {
2198 		switch (cap->c_tag) {
2199 		case CA_SUNW_HW_1:
2200 			HWCAP(lmp) = cap->c_un.c_val;
2201 			break;
2202 		case CA_SUNW_SF_1:
2203 			SFCAP(lmp) = cap->c_un.c_val;
2204 		}
2205 		cap++;
2206 	}
2207 }
2208 
2209 /*
2210  * Build full pathname of shared object from given directory name and filename.
2211  */
2212 static char *
2213 elf_get_so(const char *dir, const char *file, size_t dlen, size_t flen)
2214 {
2215 	static char	pname[PATH_MAX];
2216 
2217 	(void) strncpy(pname, dir, dlen);
2218 	pname[dlen++] = '/';
2219 	(void) strncpy(&pname[dlen], file, flen + 1);
2220 	return (pname);
2221 }
2222 
2223 /*
2224  * The copy relocation is recorded in a copy structure which will be applied
2225  * after all other relocations are carried out.  This provides for copying data
2226  * that must be relocated itself (ie. pointers in shared objects).  This
2227  * structure also provides a means of binding RTLD_GROUP dependencies to any
2228  * copy relocations that have been taken from any group members.
2229  *
2230  * If the size of the .bss area available for the copy information is not the
2231  * same as the source of the data inform the user if we're under ldd(1) control
2232  * (this checking was only established in 5.3, so by only issuing an error via
2233  * ldd(1) we maintain the standard set by previous releases).
2234  */
2235 int
2236 elf_copy_reloc(char *name, Sym *rsym, Rt_map *rlmp, void *radd, Sym *dsym,
2237     Rt_map *dlmp, const void *dadd)
2238 {
2239 	Rel_copy	rc;
2240 	Lm_list		*lml = LIST(rlmp);
2241 
2242 	rc.r_name = name;
2243 	rc.r_rsym = rsym;		/* the new reference symbol and its */
2244 	rc.r_rlmp = rlmp;		/*	associated link-map */
2245 	rc.r_dlmp = dlmp;		/* the defining link-map */
2246 	rc.r_dsym = dsym;		/* the original definition */
2247 	rc.r_radd = radd;
2248 	rc.r_dadd = dadd;
2249 
2250 	if (rsym->st_size > dsym->st_size)
2251 		rc.r_size = (size_t)dsym->st_size;
2252 	else
2253 		rc.r_size = (size_t)rsym->st_size;
2254 
2255 	if (alist_append(&COPY_R(dlmp), &rc, sizeof (Rel_copy),
2256 	    AL_CNT_COPYREL) == NULL) {
2257 		if (!(lml->lm_flags & LML_FLG_TRC_WARN))
2258 			return (0);
2259 		else
2260 			return (1);
2261 	}
2262 	if (!(FLAGS1(dlmp) & FL1_RT_COPYTOOK)) {
2263 		if (aplist_append(&COPY_S(rlmp), dlmp,
2264 		    AL_CNT_COPYREL) == NULL) {
2265 			if (!(lml->lm_flags & LML_FLG_TRC_WARN))
2266 				return (0);
2267 			else
2268 				return (1);
2269 		}
2270 		FLAGS1(dlmp) |= FL1_RT_COPYTOOK;
2271 	}
2272 
2273 	/*
2274 	 * If we are tracing (ldd), warn the user if
2275 	 *	1) the size from the reference symbol differs from the
2276 	 *	   copy definition. We can only copy as much data as the
2277 	 *	   reference (dynamic executables) entry allows.
2278 	 *	2) the copy definition has STV_PROTECTED visibility.
2279 	 */
2280 	if (lml->lm_flags & LML_FLG_TRC_WARN) {
2281 		if (rsym->st_size != dsym->st_size) {
2282 			(void) printf(MSG_INTL(MSG_LDD_CPY_SIZDIF),
2283 			    _conv_reloc_type(M_R_COPY), demangle(name),
2284 			    NAME(rlmp), EC_XWORD(rsym->st_size),
2285 			    NAME(dlmp), EC_XWORD(dsym->st_size));
2286 			if (rsym->st_size > dsym->st_size)
2287 				(void) printf(MSG_INTL(MSG_LDD_CPY_INSDATA),
2288 				    NAME(dlmp));
2289 			else
2290 				(void) printf(MSG_INTL(MSG_LDD_CPY_DATRUNC),
2291 				    NAME(rlmp));
2292 		}
2293 
2294 		if (ELF_ST_VISIBILITY(dsym->st_other) == STV_PROTECTED) {
2295 			(void) printf(MSG_INTL(MSG_LDD_CPY_PROT),
2296 			    _conv_reloc_type(M_R_COPY), demangle(name),
2297 			    NAME(dlmp));
2298 		}
2299 	}
2300 
2301 	DBG_CALL(Dbg_reloc_apply_val(lml, ELF_DBG_RTLD, (Xword)radd,
2302 	    (Xword)rc.r_size));
2303 	return (1);
2304 }
2305 
2306 /*
2307  * Determine the symbol location of an address within a link-map.  Look for
2308  * the nearest symbol (whose value is less than or equal to the required
2309  * address).  This is the object specific part of dladdr().
2310  */
2311 static void
2312 elf_dladdr(ulong_t addr, Rt_map *lmp, Dl_info *dlip, void **info, int flags)
2313 {
2314 	ulong_t		ndx, cnt, base, _value;
2315 	Sym		*sym, *_sym = NULL;
2316 	const char	*str;
2317 	int		_flags;
2318 	uint_t		*dynaddr_ndx;
2319 	uint_t		dynaddr_n = 0;
2320 	ulong_t		value;
2321 
2322 	/*
2323 	 * If SUNWSYMTAB() is non-NULL, then it sees a special version of
2324 	 * the dynsym that starts with any local function symbols that exist in
2325 	 * the library and then moves to the data held in SYMTAB(). In this
2326 	 * case, SUNWSYMSZ tells us how long the symbol table is. The
2327 	 * availability of local function symbols will enhance the results
2328 	 * we can provide.
2329 	 *
2330 	 * If SUNWSYMTAB() is non-NULL, then there might also be a
2331 	 * SUNWSYMSORT() vector associated with it. SUNWSYMSORT() contains
2332 	 * an array of indices into SUNWSYMTAB, sorted by increasing
2333 	 * address. We can use this to do an O(log N) search instead of a
2334 	 * brute force search.
2335 	 *
2336 	 * If SUNWSYMTAB() is NULL, then SYMTAB() references a dynsym that
2337 	 * contains only global symbols. In that case, the length of
2338 	 * the symbol table comes from the nchain field of the related
2339 	 * symbol lookup hash table.
2340 	 */
2341 	str = STRTAB(lmp);
2342 	if (SUNWSYMSZ(lmp) == NULL) {
2343 		sym = SYMTAB(lmp);
2344 		/*
2345 		 * If we don't have a .hash table there are no symbols
2346 		 * to look at.
2347 		 */
2348 		if (HASH(lmp) == 0)
2349 			return;
2350 		cnt = HASH(lmp)[1];
2351 	} else {
2352 		sym = SUNWSYMTAB(lmp);
2353 		cnt = SUNWSYMSZ(lmp) / SYMENT(lmp);
2354 		dynaddr_ndx = SUNWSYMSORT(lmp);
2355 		if (dynaddr_ndx != NULL)
2356 			dynaddr_n = SUNWSYMSORTSZ(lmp) / SUNWSORTENT(lmp);
2357 	}
2358 
2359 	if (FLAGS(lmp) & FLG_RT_FIXED)
2360 		base = 0;
2361 	else
2362 		base = ADDR(lmp);
2363 
2364 	if (dynaddr_n > 0) {		/* Binary search */
2365 		long	low = 0, low_bnd;
2366 		long	high = dynaddr_n - 1, high_bnd;
2367 		long	mid;
2368 		Sym	*mid_sym;
2369 
2370 		/*
2371 		 * Note that SUNWSYMSORT only contains symbols types that
2372 		 * supply memory addresses, so there's no need to check and
2373 		 * filter out any other types.
2374 		 */
2375 		low_bnd = low;
2376 		high_bnd = high;
2377 		while (low <= high) {
2378 			mid = (low + high) / 2;
2379 			mid_sym = &sym[dynaddr_ndx[mid]];
2380 			value = mid_sym->st_value + base;
2381 			if (addr < value) {
2382 				if ((sym[dynaddr_ndx[high]].st_value + base) >=
2383 				    addr)
2384 					high_bnd = high;
2385 				high = mid - 1;
2386 			} else if (addr > value) {
2387 				if ((sym[dynaddr_ndx[low]].st_value + base) <=
2388 				    addr)
2389 					low_bnd = low;
2390 				low = mid + 1;
2391 			} else {
2392 				_sym = mid_sym;
2393 				_value = value;
2394 				break;
2395 			}
2396 		}
2397 		/*
2398 		 * If the above didn't find it exactly, then we must
2399 		 * return the closest symbol with a value that doesn't
2400 		 * exceed the one we are looking for. If that symbol exists,
2401 		 * it will lie in the range bounded by low_bnd and
2402 		 * high_bnd. This is a linear search, but a short one.
2403 		 */
2404 		if (_sym == NULL) {
2405 			for (mid = low_bnd; mid <= high_bnd; mid++) {
2406 				mid_sym = &sym[dynaddr_ndx[mid]];
2407 				value = mid_sym->st_value + base;
2408 				if (addr >= value) {
2409 					_sym = mid_sym;
2410 					_value = value;
2411 				} else {
2412 					break;
2413 				}
2414 			}
2415 		}
2416 	} else {			/* Linear search */
2417 		for (_value = 0, sym++, ndx = 1; ndx < cnt; ndx++, sym++) {
2418 			/*
2419 			 * Skip expected symbol types that are not functions
2420 			 * or data:
2421 			 *	- A symbol table starts with an undefined symbol
2422 			 *		in slot 0. If we are using SUNWSYMTAB(),
2423 			 *		there will be a second undefined symbol
2424 			 *		right before the globals.
2425 			 *	- The local part of SUNWSYMTAB() contains a
2426 			 *		series of function symbols. Each section
2427 			 *		starts with an initial STT_FILE symbol.
2428 			 */
2429 			if ((sym->st_shndx == SHN_UNDEF) ||
2430 			    (ELF_ST_TYPE(sym->st_info) == STT_FILE))
2431 				continue;
2432 
2433 			value = sym->st_value + base;
2434 			if (value > addr)
2435 				continue;
2436 			if (value < _value)
2437 				continue;
2438 
2439 			_sym = sym;
2440 			_value = value;
2441 
2442 			/*
2443 			 * Note, because we accept local and global symbols
2444 			 * we could find a section symbol that matches the
2445 			 * associated address, which means that the symbol
2446 			 * name will be null.  In this case continue the
2447 			 * search in case we can find a global symbol of
2448 			 * the same value.
2449 			 */
2450 			if ((value == addr) &&
2451 			    (ELF_ST_TYPE(sym->st_info) != STT_SECTION))
2452 				break;
2453 		}
2454 	}
2455 
2456 	_flags = flags & RTLD_DL_MASK;
2457 	if (_sym) {
2458 		if (_flags == RTLD_DL_SYMENT)
2459 			*info = (void *)_sym;
2460 		else if (_flags == RTLD_DL_LINKMAP)
2461 			*info = (void *)lmp;
2462 
2463 		dlip->dli_sname = str + _sym->st_name;
2464 		dlip->dli_saddr = (void *)_value;
2465 	} else {
2466 		/*
2467 		 * addr lies between the beginning of the mapped segment and
2468 		 * the first global symbol. We have no symbol to return
2469 		 * and the caller requires one. We use _START_, the base
2470 		 * address of the mapping.
2471 		 */
2472 
2473 		if (_flags == RTLD_DL_SYMENT) {
2474 			/*
2475 			 * An actual symbol struct is needed, so we
2476 			 * construct one for _START_. To do this in a
2477 			 * fully accurate way requires a different symbol
2478 			 * for each mapped segment. This requires the
2479 			 * use of dynamic memory and a mutex. That's too much
2480 			 * plumbing for a fringe case of limited importance.
2481 			 *
2482 			 * Fortunately, we can simplify:
2483 			 *    - Only the st_size and st_info fields are useful
2484 			 *	outside of the linker internals. The others
2485 			 *	reference things that outside code cannot see,
2486 			 *	and can be set to 0.
2487 			 *    - It's just a label and there is no size
2488 			 *	to report. So, the size should be 0.
2489 			 * This means that only st_info needs a non-zero
2490 			 * (constant) value. A static struct will suffice.
2491 			 * It must be const (readonly) so the caller can't
2492 			 * change its meaning for subsequent callers.
2493 			 */
2494 			static const Sym fsym = { 0, 0, 0,
2495 			    ELF_ST_INFO(STB_LOCAL, STT_OBJECT) };
2496 			*info = (void *) &fsym;
2497 		}
2498 
2499 		dlip->dli_sname = MSG_ORIG(MSG_SYM_START);
2500 		dlip->dli_saddr = (void *) ADDR(lmp);
2501 	}
2502 }
2503 
2504 static void
2505 elf_lazy_cleanup(APlist *alp)
2506 {
2507 	Rt_map	*lmp;
2508 	Aliste	idx;
2509 
2510 	/*
2511 	 * Cleanup any link-maps added to this dynamic list and free it.
2512 	 */
2513 	for (APLIST_TRAVERSE(alp, idx, lmp))
2514 		FLAGS(lmp) &= ~FLG_RT_TMPLIST;
2515 	free(alp);
2516 }
2517 
2518 /*
2519  * This routine is called as a last fall-back to search for a symbol from a
2520  * standard relocation.  To maintain lazy loadings goal of reducing the number
2521  * of objects mapped, any symbol search is first carried out using the objects
2522  * that already exist in the process (either on a link-map list or handle).
2523  * If a symbol can't be found, and lazy dependencies are still pending, this
2524  * routine loads the dependencies in an attempt to locate the symbol.
2525  *
2526  * Only new objects are inspected as we will have already inspected presently
2527  * loaded objects before calling this routine.  However, a new object may not
2528  * be new - although the di_lmp might be zero, the object may have been mapped
2529  * as someone elses dependency.  Thus there's a possibility of some symbol
2530  * search duplication.
2531  */
2532 Sym *
2533 elf_lazy_find_sym(Slookup *slp, Rt_map **_lmp, uint_t *binfo, int *in_nfavl)
2534 {
2535 	Sym		*sym = NULL;
2536 	APlist		*alist = NULL;
2537 	Aliste		idx;
2538 	Rt_map		*lmp1, *lmp = slp->sl_imap;
2539 	const char	*name = slp->sl_name;
2540 
2541 	/*
2542 	 * Generate a local list of new objects to process.  This list can grow
2543 	 * as each object supplies its own lazy dependencies.
2544 	 */
2545 	if (aplist_append(&alist, lmp, AL_CNT_LAZYFIND) == NULL)
2546 		return (NULL);
2547 	FLAGS(lmp) |= FLG_RT_TMPLIST;
2548 
2549 	for (APLIST_TRAVERSE(alist, idx, lmp1)) {
2550 		uint_t	cnt = 0;
2551 		Slookup	sl = *slp;
2552 		Dyninfo	*dip, *pdip;
2553 
2554 		/*
2555 		 * Discard any relocation index from further symbol searches.
2556 		 * This index will have already been used to trigger any
2557 		 * necessary lazy-loads, and it might be because one of these
2558 		 * lazy loads have failed that we're here performing this
2559 		 * fallback.  By removing the relocation index we don't try
2560 		 * and perform the same failed lazy loading activity again.
2561 		 */
2562 		sl.sl_rsymndx = 0;
2563 
2564 		/*
2565 		 * Loop through the lazy DT_NEEDED entries examining each object
2566 		 * for the required symbol.  If the symbol is not found, the
2567 		 * object is in turn added to the local alist, so that the
2568 		 * objects lazy DT_NEEDED entries can be examined.
2569 		 */
2570 		lmp = lmp1;
2571 		for (dip = DYNINFO(lmp), pdip = NULL; cnt < DYNINFOCNT(lmp);
2572 		    cnt++, pdip = dip++) {
2573 			Rt_map *nlmp;
2574 
2575 			if (((dip->di_flags & FLG_DI_LAZY) == 0) ||
2576 			    dip->di_info)
2577 				continue;
2578 
2579 			/*
2580 			 * If this object has already failed to lazy load, and
2581 			 * we're still processing the same runtime linker
2582 			 * operation that produced the failure, don't bother
2583 			 * to try and load the object again.
2584 			 */
2585 			if ((dip->di_flags & FLG_DI_LAZYFAIL) && pdip &&
2586 			    (pdip->di_flags & FLG_DI_POSFLAG1)) {
2587 				if (pdip->di_info == (void *)ld_entry_cnt)
2588 					continue;
2589 
2590 				dip->di_flags &= ~FLG_DI_LAZYFAIL;
2591 				pdip->di_info = NULL;
2592 			}
2593 
2594 			/*
2595 			 * Try loading this lazy dependency.  If the object
2596 			 * can't be loaded, consider this non-fatal and continue
2597 			 * the search.  Lazy loaded dependencies need not exist
2598 			 * and their loading should only turn out to be fatal
2599 			 * if they are required to satisfy a relocation.
2600 			 *
2601 			 * If the file is already loaded and relocated we must
2602 			 * still inspect it for symbols, even though it might
2603 			 * have already been searched.  This lazy load operation
2604 			 * might have promoted the permissions of the object,
2605 			 * and thus made the object applicable for this symbol
2606 			 * search, whereas before the object might have been
2607 			 * skipped.
2608 			 */
2609 			if ((nlmp = elf_lazy_load(lmp, &sl, cnt,
2610 			    name, in_nfavl)) == 0)
2611 				continue;
2612 
2613 			/*
2614 			 * If this object isn't yet a part of the dynamic list
2615 			 * then inspect it for the symbol.  If the symbol isn't
2616 			 * found add the object to the dynamic list so that we
2617 			 * can inspect its dependencies.
2618 			 */
2619 			if (FLAGS(nlmp) & FLG_RT_TMPLIST)
2620 				continue;
2621 
2622 			sl.sl_imap = nlmp;
2623 			if (sym = LM_LOOKUP_SYM(sl.sl_cmap)(&sl, _lmp,
2624 			    binfo, in_nfavl))
2625 				break;
2626 
2627 			/*
2628 			 * Some dlsym() operations are already traversing a
2629 			 * link-map (dlopen(0)), and thus there's no need to
2630 			 * build our own dynamic dependency list.
2631 			 */
2632 			if ((sl.sl_flags & LKUP_NODESCENT) == 0) {
2633 				if (aplist_append(&alist, nlmp,
2634 				    AL_CNT_LAZYFIND) == NULL) {
2635 					elf_lazy_cleanup(alist);
2636 					return (NULL);
2637 				}
2638 				FLAGS(nlmp) |= FLG_RT_TMPLIST;
2639 			}
2640 		}
2641 		if (sym)
2642 			break;
2643 	}
2644 
2645 	elf_lazy_cleanup(alist);
2646 	return (sym);
2647 }
2648 
2649 /*
2650  * Warning message for bad r_offset.
2651  */
2652 void
2653 elf_reloc_bad(Rt_map *lmp, void *rel, uchar_t rtype, ulong_t roffset,
2654     ulong_t rsymndx)
2655 {
2656 	const char	*name = NULL;
2657 	Lm_list		*lml = LIST(lmp);
2658 	int		trace;
2659 
2660 	if ((lml->lm_flags & LML_FLG_TRC_ENABLE) &&
2661 	    (((rtld_flags & RT_FL_SILENCERR) == 0) ||
2662 	    (lml->lm_flags & LML_FLG_TRC_VERBOSE)))
2663 		trace = 1;
2664 	else
2665 		trace = 0;
2666 
2667 	if ((trace == 0) && (DBG_ENABLED == 0))
2668 		return;
2669 
2670 	if (rsymndx) {
2671 		Sym	*symref = (Sym *)((ulong_t)SYMTAB(lmp) +
2672 		    (rsymndx * SYMENT(lmp)));
2673 
2674 		if (ELF_ST_BIND(symref->st_info) != STB_LOCAL)
2675 			name = (char *)(STRTAB(lmp) + symref->st_name);
2676 	}
2677 
2678 	if (name == 0)
2679 		name = MSG_INTL(MSG_STR_UNKNOWN);
2680 
2681 	if (trace) {
2682 		const char *rstr;
2683 
2684 		rstr = _conv_reloc_type((uint_t)rtype);
2685 		(void) printf(MSG_INTL(MSG_LDD_REL_ERR1), rstr, name,
2686 		    EC_ADDR(roffset));
2687 		return;
2688 	}
2689 
2690 	Dbg_reloc_error(lml, ELF_DBG_RTLD, M_MACH, M_REL_SHT_TYPE, rel, name);
2691 }
2692 
2693 /*
2694  * Resolve a static TLS relocation.
2695  */
2696 long
2697 elf_static_tls(Rt_map *lmp, Sym *sym, void *rel, uchar_t rtype, char *name,
2698     ulong_t roffset, long value)
2699 {
2700 	Lm_list	*lml = LIST(lmp);
2701 
2702 	/*
2703 	 * Relocations against a static TLS block have limited support once
2704 	 * process initialization has completed.  Any error condition should be
2705 	 * discovered by testing for DF_STATIC_TLS as part of loading an object,
2706 	 * however individual relocations are tested in case the dynamic flag
2707 	 * had not been set when this object was built.
2708 	 */
2709 	if (PTTLS(lmp) == 0) {
2710 		DBG_CALL(Dbg_reloc_in(lml, ELF_DBG_RTLD, M_MACH,
2711 		    M_REL_SHT_TYPE, rel, NULL, name));
2712 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_REL_BADTLS),
2713 		    _conv_reloc_type((uint_t)rtype), NAME(lmp),
2714 		    name ? demangle(name) : MSG_INTL(MSG_STR_UNKNOWN));
2715 		return (0);
2716 	}
2717 
2718 	/*
2719 	 * If no static TLS has been set aside for this object, determine if
2720 	 * any can be obtained.  Enforce that any object using static TLS is
2721 	 * non-deletable.
2722 	 */
2723 	if (TLSSTATOFF(lmp) == 0) {
2724 		FLAGS1(lmp) |= FL1_RT_TLSSTAT;
2725 		MODE(lmp) |= RTLD_NODELETE;
2726 
2727 		if (tls_assign(lml, lmp, PTTLS(lmp)) == 0) {
2728 			DBG_CALL(Dbg_reloc_in(lml, ELF_DBG_RTLD, M_MACH,
2729 			    M_REL_SHT_TYPE, rel, NULL, name));
2730 			eprintf(lml, ERR_FATAL, MSG_INTL(MSG_REL_BADTLS),
2731 			    _conv_reloc_type((uint_t)rtype), NAME(lmp),
2732 			    name ? demangle(name) : MSG_INTL(MSG_STR_UNKNOWN));
2733 			return (0);
2734 		}
2735 	}
2736 
2737 	/*
2738 	 * Typically, a static TLS offset is maintained as a symbols value.
2739 	 * For local symbols that are not apart of the dynamic symbol table,
2740 	 * the TLS relocation points to a section symbol, and the static TLS
2741 	 * offset was deposited in the associated GOT table.  Make sure the GOT
2742 	 * is cleared, so that the value isn't reused in do_reloc().
2743 	 */
2744 	if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) {
2745 		if ((ELF_ST_TYPE(sym->st_info) == STT_SECTION)) {
2746 			value = *(long *)roffset;
2747 			*(long *)roffset = 0;
2748 		} else {
2749 			value = sym->st_value;
2750 		}
2751 	}
2752 	return (-(TLSSTATOFF(lmp) - value));
2753 }
2754 
2755 /*
2756  * If the symbol is not found and the reference was not to a weak symbol, report
2757  * an error.  Weak references may be unresolved.
2758  */
2759 int
2760 elf_reloc_error(Rt_map *lmp, const char *name, void *rel, uint_t binfo)
2761 {
2762 	Lm_list	*lml = LIST(lmp);
2763 
2764 	/*
2765 	 * Under crle(1), relocation failures are ignored.
2766 	 */
2767 	if (lml->lm_flags & LML_FLG_IGNRELERR)
2768 		return (1);
2769 
2770 	/*
2771 	 * Under ldd(1), unresolved references are reported.  However, if the
2772 	 * original reference is EXTERN or PARENT these references are ignored
2773 	 * unless ldd's -p option is in effect.
2774 	 */
2775 	if (lml->lm_flags & LML_FLG_TRC_WARN) {
2776 		if (((binfo & DBG_BINFO_REF_MSK) == 0) ||
2777 		    ((lml->lm_flags & LML_FLG_TRC_NOPAREXT) != 0)) {
2778 			(void) printf(MSG_INTL(MSG_LDD_SYM_NFOUND),
2779 			    demangle(name), NAME(lmp));
2780 		}
2781 		return (1);
2782 	}
2783 
2784 	/*
2785 	 * Otherwise, the unresolved references is fatal.
2786 	 */
2787 	DBG_CALL(Dbg_reloc_in(lml, ELF_DBG_RTLD, M_MACH, M_REL_SHT_TYPE, rel,
2788 	    NULL, name));
2789 	eprintf(lml, ERR_FATAL, MSG_INTL(MSG_REL_NOSYM), NAME(lmp),
2790 	    demangle(name));
2791 
2792 	return (0);
2793 }
2794 
2795 /*
2796  * Generic relative relocation function.
2797  */
2798 inline static ulong_t
2799 _elf_reloc_relative(ulong_t rbgn, ulong_t base, Rt_map *lmp, APlist **textrel)
2800 {
2801 	mmapobj_result_t	*mpp;
2802 	ulong_t			roffset;
2803 
2804 	roffset = ((M_RELOC *)rbgn)->r_offset;
2805 	roffset += base;
2806 
2807 	/*
2808 	 * If this relocation is against an address that is not associated with
2809 	 * a mapped segment, fall back to the generic relocation loop to
2810 	 * collect the associated error.
2811 	 */
2812 	if ((mpp = find_segment((caddr_t)roffset, lmp)) == NULL)
2813 		return (0);
2814 
2815 	/*
2816 	 * If this relocation is against a segment that does not provide write
2817 	 * access, set the write permission for all non-writable mappings.
2818 	 */
2819 	if (((mpp->mr_prot & PROT_WRITE) == 0) && textrel &&
2820 	    ((set_prot(lmp, mpp, 1) == 0) ||
2821 	    (aplist_append(textrel, mpp, AL_CNT_TEXTREL) == NULL)))
2822 		return (0);
2823 
2824 	/*
2825 	 * Perform the actual relocation.  Note, for backward compatibility,
2826 	 * SPARC relocations are added to the offset contents (there was a time
2827 	 * when the offset was used to contain the addend, rather than using
2828 	 * the addend itself).
2829 	 */
2830 #if	defined(__sparc)
2831 	*((ulong_t *)roffset) += base + ((M_RELOC *)rbgn)->r_addend;
2832 #elif	defined(__amd64)
2833 	*((ulong_t *)roffset) = base + ((M_RELOC *)rbgn)->r_addend;
2834 #else
2835 	*((ulong_t *)roffset) += base;
2836 #endif
2837 	return (1);
2838 }
2839 
2840 /*
2841  * When a generic relocation loop realizes that it's dealing with relative
2842  * relocations, but no DT_RELCOUNT .dynamic tag is present, this tighter loop
2843  * is entered as an optimization.
2844  */
2845 ulong_t
2846 elf_reloc_relative(ulong_t rbgn, ulong_t rend, ulong_t rsize, ulong_t base,
2847     Rt_map *lmp, APlist **textrel)
2848 {
2849 	char	rtype;
2850 
2851 	do {
2852 		if (_elf_reloc_relative(rbgn, base, lmp, textrel) == 0)
2853 			break;
2854 
2855 		rbgn += rsize;
2856 		if (rbgn >= rend)
2857 			break;
2858 
2859 		/*
2860 		 * Make sure the next type is a relative relocation.
2861 		 */
2862 		rtype = ELF_R_TYPE(((M_RELOC *)rbgn)->r_info, M_MACH);
2863 
2864 	} while (rtype == M_R_RELATIVE);
2865 
2866 	return (rbgn);
2867 }
2868 
2869 /*
2870  * This is the tightest loop for RELATIVE relocations for those objects built
2871  * with the DT_RELACOUNT .dynamic entry.
2872  */
2873 ulong_t
2874 elf_reloc_relative_count(ulong_t rbgn, ulong_t rcount, ulong_t rsize,
2875     ulong_t base, Rt_map *lmp, APlist **textrel)
2876 {
2877 	for (; rcount; rcount--) {
2878 		if (_elf_reloc_relative(rbgn, base, lmp, textrel) == 0)
2879 			break;
2880 
2881 		rbgn += rsize;
2882 	}
2883 	return (rbgn);
2884 }
2885