xref: /illumos-gate/usr/src/cmd/sgs/rtld/common/elf.c (revision 7b4c5c8b4fd48b69fab033a244cf1eaf942ee6bd)
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, NULL, sizeof (Pdesc),
152 		    alni)) == NULL)
153 			return (0);
154 
155 		pdp->pd_pname = (char *)MSG_ORIG(MSG_PTH_LIBSYS);
156 		pdp->pd_plen = MSG_PTH_LIBSYS_SIZE;
157 		pdp->pd_flags = PD_FLG_PNSLASH;
158 
159 		return (1);
160 	}
161 
162 	return (expand_paths(clmp, name, alpp, alni, orig, 0));
163 }
164 
165 /*
166  * Determine whether this object requires any hardware or software capabilities.
167  */
168 static int
169 elf_cap_check(Fdesc *fdp, Ehdr *ehdr, Rej_desc *rej)
170 {
171 	Phdr	*phdr;
172 	int	cnt;
173 
174 	/* LINTED */
175 	phdr = (Phdr *)((char *)ehdr + ehdr->e_phoff);
176 	for (cnt = 0; cnt < ehdr->e_phnum; cnt++, phdr++) {
177 		Cap	*cptr;
178 
179 		if (phdr->p_type != PT_SUNWCAP)
180 			continue;
181 
182 		/* LINTED */
183 		cptr = (Cap *)((char *)ehdr + phdr->p_offset);
184 		while (cptr->c_tag != CA_SUNW_NULL) {
185 			if (cptr->c_tag == CA_SUNW_HW_1) {
186 				/*
187 				 * Verify the hardware capabilities.
188 				 */
189 				if (hwcap_check(cptr->c_un.c_val, rej) == 0)
190 					return (0);
191 
192 				/*
193 				 * Retain this hardware capabilities value for
194 				 * possible later inspection should this object
195 				 * be processed as a filtee.
196 				 */
197 				fdp->fd_hwcap = cptr->c_un.c_val;
198 			}
199 			if (cptr->c_tag == CA_SUNW_SF_1) {
200 				/*
201 				 * Verify the software capabilities.
202 				 */
203 				if (sfcap_check(cptr->c_un.c_val, rej) == 0)
204 					return (0);
205 			}
206 			cptr++;
207 		}
208 	}
209 	return (1);
210 }
211 
212 /*
213  * Determine if we have been given an ELF file and if so determine if the file
214  * is compatible.  Returns 1 if true, else 0 and sets the reject descriptor
215  * with associated error information.
216  */
217 Fct *
218 elf_verify(caddr_t addr, size_t size, Fdesc *fdp, const char *name,
219     Rej_desc *rej)
220 {
221 	Ehdr	*ehdr;
222 	char	*caddr = (char *)addr;
223 
224 	/*
225 	 * Determine if we're an elf file.  If not simply return, we don't set
226 	 * any rejection information as this test allows use to scroll through
227 	 * the objects we support (ELF, AOUT).
228 	 */
229 	if (size < sizeof (Ehdr) ||
230 	    caddr[EI_MAG0] != ELFMAG0 ||
231 	    caddr[EI_MAG1] != ELFMAG1 ||
232 	    caddr[EI_MAG2] != ELFMAG2 ||
233 	    caddr[EI_MAG3] != ELFMAG3) {
234 		return (NULL);
235 	}
236 
237 	/*
238 	 * Check class and encoding.
239 	 */
240 	/* LINTED */
241 	ehdr = (Ehdr *)addr;
242 	if (ehdr->e_ident[EI_CLASS] != M_CLASS) {
243 		rej->rej_type = SGS_REJ_CLASS;
244 		rej->rej_info = (uint_t)ehdr->e_ident[EI_CLASS];
245 		return (NULL);
246 	}
247 	if (ehdr->e_ident[EI_DATA] != M_DATA) {
248 		rej->rej_type = SGS_REJ_DATA;
249 		rej->rej_info = (uint_t)ehdr->e_ident[EI_DATA];
250 		return (NULL);
251 	}
252 	if ((ehdr->e_type != ET_REL) && (ehdr->e_type != ET_EXEC) &&
253 	    (ehdr->e_type != ET_DYN)) {
254 		rej->rej_type = SGS_REJ_TYPE;
255 		rej->rej_info = (uint_t)ehdr->e_type;
256 		return (NULL);
257 	}
258 
259 	/*
260 	 * Verify ELF version.
261 	 */
262 	if (ehdr->e_version > EV_CURRENT) {
263 		rej->rej_type = SGS_REJ_VERSION;
264 		rej->rej_info = (uint_t)ehdr->e_version;
265 		return (NULL);
266 	}
267 
268 	/*
269 	 * Verify machine specific flags.
270 	 */
271 	if (elf_mach_flags_check(rej, ehdr) == 0)
272 		return (NULL);
273 
274 	/*
275 	 * Verify any hardware/software capability requirements.  Note, if this
276 	 * object is an explicitly defined shared object under inspection by
277 	 * ldd(1), and contains an incompatible hardware capabilities
278 	 * requirement, then inform the user, but continue processing.
279 	 */
280 	if (elf_cap_check(fdp, ehdr, rej) == 0) {
281 		Rt_map	*lmp = lml_main.lm_head;
282 
283 		if ((lml_main.lm_flags & LML_FLG_TRC_LDDSTUB) && lmp &&
284 		    (FLAGS1(lmp) & FL1_RT_LDDSTUB) && (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  *  -	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  *  -	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 	 *  -	JMPSLOT relocations (PLT's) actually need a relative relocation
336 	 *	applied to the GOT entry so that they can find PLT0.
337 	 *
338 	 *  -	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     uint_t flags, Grp_hdl **hdl, int *in_nfavl)
357 {
358 	Alist		*palp = NULL;
359 	Rt_map		*nlmp;
360 	Dyninfo		*dip = &DYNINFO(clmp)[ndx], *pdip;
361 	const char	*name;
362 	Lm_list		*lml = LIST(clmp);
363 	Aliste		lmco;
364 
365 	/*
366 	 * If this dependency has already been processed, we're done.
367 	 */
368 	if (((nlmp = (Rt_map *)dip->di_info) != NULL) ||
369 	    (dip->di_flags & FLG_DI_LDD_DONE))
370 		return (nlmp);
371 
372 	/*
373 	 * If we're running under ldd(1), indicate that this dependency has been
374 	 * processed (see test above).  It doesn't matter whether the object is
375 	 * successfully loaded or not, this flag simply ensures that we don't
376 	 * repeatedly attempt to load an object that has already failed to load.
377 	 * To do so would create multiple failure diagnostics for the same
378 	 * object under ldd(1).
379 	 */
380 	if (lml->lm_flags & LML_FLG_TRC_ENABLE)
381 		dip->di_flags |= FLG_DI_LDD_DONE;
382 
383 	/*
384 	 * Determine the initial dependency name.
385 	 */
386 	name = STRTAB(clmp) + DYN(clmp)[ndx].d_un.d_val;
387 	DBG_CALL(Dbg_file_lazyload(clmp, name, sym));
388 
389 	/*
390 	 * If this object needs to establish its own group, make sure a handle
391 	 * is created.
392 	 */
393 	if (dip->di_flags & FLG_DI_GROUP)
394 		flags |= (FLG_RT_SETGROUP | FLG_RT_PUBHDL);
395 
396 	/*
397 	 * Lazy dependencies are identified as DT_NEEDED entries with a
398 	 * DF_P1_LAZYLOAD flag in the previous DT_POSFLAG_1 element.  The
399 	 * dynamic information element that corresponds to the DT_POSFLAG_1
400 	 * entry is free, and thus used to store the present entrance
401 	 * identifier.  This identifier is used to prevent multiple attempts to
402 	 * load a failed lazy loadable dependency within the same runtime linker
403 	 * operation.  However, future attempts to reload this dependency are
404 	 * still possible.
405 	 */
406 	if (ndx && (pdip = dip - 1) && (pdip->di_flags & FLG_DI_POSFLAG1))
407 		pdip->di_info = (void *)slp->sl_id;
408 
409 	/*
410 	 * Expand the requested name if necessary.
411 	 */
412 	if (elf_fix_name(name, clmp, &palp, AL_CNT_NEEDED, 0) == 0)
413 		return (NULL);
414 
415 	/*
416 	 * Establish a link-map control list for this request.
417 	 */
418 	if ((lmco = create_cntl(lml, 0)) == NULL) {
419 		remove_plist(&palp, 1);
420 		return (NULL);
421 	}
422 
423 	/*
424 	 * Load the associated object.
425 	 */
426 	dip->di_info = nlmp =
427 	    load_one(lml, lmco, palp, clmp, MODE(clmp), flags, hdl, in_nfavl);
428 
429 	/*
430 	 * Remove any expanded pathname infrastructure.  Reduce the pending lazy
431 	 * dependency count of the caller, together with the link-map lists
432 	 * count of objects that still have lazy dependencies pending.
433 	 */
434 	remove_plist(&palp, 1);
435 	if (--LAZY(clmp) == 0)
436 		LIST(clmp)->lm_lazy--;
437 
438 	/*
439 	 * Finish processing the objects associated with this request, and
440 	 * create an association between the caller and this dependency.
441 	 */
442 	if (nlmp && ((bind_one(clmp, nlmp, BND_NEEDED) == 0) ||
443 	    ((nlmp = analyze_lmc(lml, lmco, nlmp, in_nfavl)) == NULL) ||
444 	    (relocate_lmc(lml, lmco, clmp, nlmp, in_nfavl) == 0)))
445 		dip->di_info = nlmp = NULL;
446 
447 	/*
448 	 * If this lazyload has failed, and we've created a new link-map
449 	 * control list to which this request has added objects, then remove
450 	 * all the objects that have been associated to this request.
451 	 */
452 	if ((nlmp == NULL) && (lmco != ALIST_OFF_DATA))
453 		remove_lmc(lml, clmp, lmco, name);
454 
455 	/*
456 	 * Remove any temporary link-map control list.
457 	 */
458 	if (lmco != ALIST_OFF_DATA)
459 		remove_cntl(lml, lmco);
460 
461 	/*
462 	 * If this lazy loading failed, record the fact, and bump the lazy
463 	 * counts.
464 	 */
465 	if (nlmp == NULL) {
466 		dip->di_flags |= FLG_DI_LAZYFAIL;
467 		if (LAZY(clmp)++ == 0)
468 			LIST(clmp)->lm_lazy++;
469 	}
470 
471 	return (nlmp);
472 }
473 
474 /*
475  * Return the entry point of the ELF executable.
476  */
477 static Addr
478 elf_entry_point(void)
479 {
480 	Rt_map	*lmp = lml_main.lm_head;
481 	Ehdr	*ehdr = (Ehdr *)ADDR(lmp);
482 	Addr	addr = (Addr)(ehdr->e_entry);
483 
484 	if ((FLAGS(lmp) & FLG_RT_FIXED) == 0)
485 		addr += ADDR(lmp);
486 
487 	return (addr);
488 }
489 
490 /*
491  * Determine if a dependency requires a particular version and if so verify
492  * that the version exists in the dependency.
493  */
494 int
495 elf_verify_vers(const char *name, Rt_map *clmp, Rt_map *nlmp)
496 {
497 	Verneed		*vnd = VERNEED(clmp);
498 	int		_num, num = VERNEEDNUM(clmp);
499 	char		*cstrs = (char *)STRTAB(clmp);
500 	Lm_list		*lml = LIST(clmp);
501 
502 	/*
503 	 * Traverse the callers version needed information and determine if any
504 	 * specific versions are required from the dependency.
505 	 */
506 	DBG_CALL(Dbg_ver_need_title(LIST(clmp), NAME(clmp)));
507 	for (_num = 1; _num <= num; _num++,
508 	    vnd = (Verneed *)((Xword)vnd + vnd->vn_next)) {
509 		Half		cnt = vnd->vn_cnt;
510 		Vernaux		*vnap;
511 		char		*nstrs, *need;
512 
513 		/*
514 		 * Determine if a needed entry matches this dependency.
515 		 */
516 		need = (char *)(cstrs + vnd->vn_file);
517 		if (strcmp(name, need) != 0)
518 			continue;
519 
520 		if ((lml->lm_flags & LML_FLG_TRC_VERBOSE) &&
521 		    ((FLAGS1(clmp) & FL1_RT_LDDSTUB) == 0))
522 			(void) printf(MSG_INTL(MSG_LDD_VER_FIND), name);
523 
524 		/*
525 		 * Validate that each version required actually exists in the
526 		 * dependency.
527 		 */
528 		nstrs = (char *)STRTAB(nlmp);
529 
530 		for (vnap = (Vernaux *)((Xword)vnd + vnd->vn_aux); cnt;
531 		    cnt--, vnap = (Vernaux *)((Xword)vnap + vnap->vna_next)) {
532 			char		*version, *define;
533 			Verdef		*vdf = VERDEF(nlmp);
534 			ulong_t		_num, num = VERDEFNUM(nlmp);
535 			int		found = 0;
536 
537 			/*
538 			 * Skip validation of versions that are marked
539 			 * INFO. This optimization is used for versions
540 			 * that are inherited by another version. Verification
541 			 * of the inheriting version is sufficient.
542 			 *
543 			 * Such versions are recorded in the object for the
544 			 * benefit of VERSYM entries that refer to them. This
545 			 * provides a purely diagnositic benefit.
546 			 */
547 			if (vnap->vna_flags & VER_FLG_INFO)
548 				continue;
549 
550 			version = (char *)(cstrs + vnap->vna_name);
551 			DBG_CALL(Dbg_ver_need_entry(lml, 0, need, version));
552 
553 			for (_num = 1; _num <= num; _num++,
554 			    vdf = (Verdef *)((Xword)vdf + vdf->vd_next)) {
555 				Verdaux		*vdap;
556 
557 				if (vnap->vna_hash != vdf->vd_hash)
558 					continue;
559 
560 				vdap = (Verdaux *)((Xword)vdf + vdf->vd_aux);
561 				define = (char *)(nstrs + vdap->vda_name);
562 				if (strcmp(version, define) != 0)
563 					continue;
564 
565 				found++;
566 				break;
567 			}
568 
569 			/*
570 			 * If we're being traced print out any matched version
571 			 * when the verbose (-v) option is in effect.  Always
572 			 * print any unmatched versions.
573 			 */
574 			if (lml->lm_flags & LML_FLG_TRC_ENABLE) {
575 				/* BEGIN CSTYLED */
576 				if (found) {
577 				    if (!(lml->lm_flags & LML_FLG_TRC_VERBOSE))
578 					continue;
579 
580 				    (void) printf(MSG_ORIG(MSG_LDD_VER_FOUND),
581 					need, version, NAME(nlmp));
582 				} else {
583 				    if (rtld_flags & RT_FL_SILENCERR)
584 					continue;
585 
586 				    (void) printf(MSG_INTL(MSG_LDD_VER_NFOUND),
587 					need, version);
588 				}
589 				/* END CSTYLED */
590 				continue;
591 			}
592 
593 			/*
594 			 * If the version hasn't been found then this is a
595 			 * candidate for a fatal error condition.  Weak
596 			 * version definition requirements are silently
597 			 * ignored.  Also, if the image inspected for a version
598 			 * definition has no versioning recorded at all then
599 			 * silently ignore this (this provides better backward
600 			 * compatibility to old images created prior to
601 			 * versioning being available).  Both of these skipped
602 			 * diagnostics are available under tracing (see above).
603 			 */
604 			if ((found == 0) && (num != 0) &&
605 			    (!(vnap->vna_flags & VER_FLG_WEAK))) {
606 				eprintf(lml, ERR_FATAL,
607 				    MSG_INTL(MSG_VER_NFOUND), need, version,
608 				    NAME(clmp));
609 				return (0);
610 			}
611 		}
612 	}
613 	DBG_CALL(Dbg_util_nl(lml, DBG_NL_STD));
614 	return (1);
615 }
616 
617 /*
618  * Search through the dynamic section for DT_NEEDED entries and perform one
619  * of two functions.  If only the first argument is specified then load the
620  * defined shared object, otherwise add the link map representing the defined
621  * link map the the dlopen list.
622  */
623 static int
624 elf_needed(Lm_list *lml, Aliste lmco, Rt_map *clmp, int *in_nfavl)
625 {
626 	Alist		*palp = NULL;
627 	Dyn		*dyn, *pdyn;
628 	ulong_t		ndx = 0;
629 	uint_t		lazy, flags;
630 	Word		lmflags = lml->lm_flags;
631 	Word		lmtflags = lml->lm_tflags;
632 
633 	/*
634 	 * Process each shared object on needed list.
635 	 */
636 	if (DYN(clmp) == NULL)
637 		return (1);
638 
639 	for (dyn = (Dyn *)DYN(clmp), pdyn = NULL; dyn->d_tag != DT_NULL;
640 	    pdyn = dyn++, ndx++) {
641 		Dyninfo	*dip = &DYNINFO(clmp)[ndx];
642 		Rt_map	*nlmp = NULL;
643 		char	*name;
644 		int	silent = 0;
645 
646 		switch (dyn->d_tag) {
647 		case DT_POSFLAG_1:
648 			dip->di_flags |= FLG_DI_POSFLAG1;
649 			continue;
650 		case DT_NEEDED:
651 		case DT_USED:
652 			lazy = flags = 0;
653 			dip->di_flags |= FLG_DI_NEEDED;
654 
655 			if (pdyn && (pdyn->d_tag == DT_POSFLAG_1)) {
656 				if ((pdyn->d_un.d_val & DF_P1_LAZYLOAD) &&
657 				    ((lmtflags & LML_TFLG_NOLAZYLD) == 0)) {
658 					dip->di_flags |= FLG_DI_LAZY;
659 					lazy = 1;
660 				}
661 				if (pdyn->d_un.d_val & DF_P1_GROUPPERM) {
662 					dip->di_flags |= FLG_DI_GROUP;
663 					flags =
664 					    (FLG_RT_SETGROUP | FLG_RT_PUBHDL);
665 				}
666 			}
667 
668 			name = (char *)STRTAB(clmp) + dyn->d_un.d_val;
669 
670 			/*
671 			 * NOTE, libc.so.1 can't be lazy loaded.  Although a
672 			 * lazy position flag won't be produced when a RTLDINFO
673 			 * .dynamic entry is found (introduced with the UPM in
674 			 * Solaris 10), it was possible to mark libc for lazy
675 			 * loading on previous releases.  To reduce the overhead
676 			 * of testing for this occurrence, only carry out this
677 			 * check for the first object on the link-map list
678 			 * (there aren't many applications built without libc).
679 			 */
680 			if (lazy && (lml->lm_head == clmp) &&
681 			    (strcmp(name, MSG_ORIG(MSG_FIL_LIBC)) == 0))
682 				lazy = 0;
683 
684 			/*
685 			 * Don't bring in lazy loaded objects yet unless we've
686 			 * been asked to attempt to load all available objects
687 			 * (crle(1) sets LD_FLAGS=loadavail).  Even under
688 			 * RTLD_NOW we don't process this - RTLD_NOW will cause
689 			 * relocation processing which in turn might trigger
690 			 * lazy loading, but its possible that the object has a
691 			 * lazy loaded file with no bindings (i.e., it should
692 			 * never have been a dependency in the first place).
693 			 */
694 			if (lazy) {
695 				if ((lmflags & LML_FLG_LOADAVAIL) == 0) {
696 					LAZY(clmp)++;
697 					lazy = flags = 0;
698 					continue;
699 				}
700 
701 				/*
702 				 * Silence any error messages - see description
703 				 * under elf_lookup_filtee().
704 				 */
705 				if ((rtld_flags & RT_FL_SILENCERR) == 0) {
706 					rtld_flags |= RT_FL_SILENCERR;
707 					silent = 1;
708 				}
709 			}
710 			break;
711 		case DT_AUXILIARY:
712 			dip->di_flags |= FLG_DI_AUXFLTR;
713 			continue;
714 		case DT_SUNW_AUXILIARY:
715 			dip->di_flags |= (FLG_DI_AUXFLTR | FLG_DI_SYMFLTR);
716 			continue;
717 		case DT_FILTER:
718 			dip->di_flags |= FLG_DI_STDFLTR;
719 			continue;
720 		case DT_SUNW_FILTER:
721 			dip->di_flags |= (FLG_DI_STDFLTR | FLG_DI_SYMFLTR);
722 			continue;
723 		default:
724 			continue;
725 		}
726 
727 		DBG_CALL(Dbg_file_needed(clmp, name));
728 
729 		/*
730 		 * If we're running under ldd(1), indicate that this dependency
731 		 * has been processed.  It doesn't matter whether the object is
732 		 * successfully loaded or not, this flag simply ensures that we
733 		 * don't repeatedly attempt to load an object that has already
734 		 * failed to load.  To do so would create multiple failure
735 		 * diagnostics for the same object under ldd(1).
736 		 */
737 		if (lml->lm_flags & LML_FLG_TRC_ENABLE)
738 			dip->di_flags |= FLG_DI_LDD_DONE;
739 
740 		/*
741 		 * Establish the objects name, load it and establish a binding
742 		 * with the caller.
743 		 */
744 		if ((elf_fix_name(name, clmp, &palp, AL_CNT_NEEDED, 0) == 0) ||
745 		    ((nlmp = load_one(lml, lmco, palp, clmp, MODE(clmp),
746 		    flags, 0, in_nfavl)) == NULL) ||
747 		    (bind_one(clmp, nlmp, BND_NEEDED) == 0))
748 			nlmp = NULL;
749 
750 		/*
751 		 * Clean up any infrastructure, including the removal of the
752 		 * error suppression state, if it had been previously set in
753 		 * this routine.
754 		 */
755 		remove_plist(&palp, 0);
756 
757 		if (silent)
758 			rtld_flags &= ~RT_FL_SILENCERR;
759 
760 		if ((dip->di_info = (void *)nlmp) == NULL) {
761 			/*
762 			 * If the object could not be mapped, continue if error
763 			 * suppression is established or we're here with ldd(1).
764 			 */
765 			if ((MODE(clmp) & RTLD_CONFGEN) || (lmflags &
766 			    (LML_FLG_LOADAVAIL | LML_FLG_TRC_ENABLE)))
767 				continue;
768 			else {
769 				remove_plist(&palp, 1);
770 				return (0);
771 			}
772 		}
773 	}
774 
775 	if (LAZY(clmp))
776 		lml->lm_lazy++;
777 
778 	remove_plist(&palp, 1);
779 	return (1);
780 }
781 
782 /*
783  * A null symbol interpretor.  Used if a filter has no associated filtees.
784  */
785 /* ARGSUSED0 */
786 static Sym *
787 elf_null_find_sym(Slookup *slp, Rt_map **dlmp, uint_t *binfo, int *in_nfavl)
788 {
789 	return (NULL);
790 }
791 
792 /*
793  * Disable filtee use.
794  */
795 static void
796 elf_disable_filtee(Rt_map *lmp, Dyninfo *dip)
797 {
798 	if ((dip->di_flags & FLG_DI_SYMFLTR) == 0) {
799 		/*
800 		 * If this is an object filter, null out the reference name.
801 		 */
802 		if (OBJFLTRNDX(lmp) != FLTR_DISABLED) {
803 			REFNAME(lmp) = NULL;
804 			OBJFLTRNDX(lmp) = FLTR_DISABLED;
805 
806 			/*
807 			 * Indicate that this filtee is no longer available.
808 			 */
809 			if (dip->di_flags & FLG_DI_STDFLTR)
810 				SYMINTP(lmp) = elf_null_find_sym;
811 
812 		}
813 	} else if (dip->di_flags & FLG_DI_STDFLTR) {
814 		/*
815 		 * Indicate that this standard filtee is no longer available.
816 		 */
817 		if (SYMSFLTRCNT(lmp))
818 			SYMSFLTRCNT(lmp)--;
819 	} else {
820 		/*
821 		 * Indicate that this auxiliary filtee is no longer available.
822 		 */
823 		if (SYMAFLTRCNT(lmp))
824 			SYMAFLTRCNT(lmp)--;
825 	}
826 	dip->di_flags &= ~MSK_DI_FILTER;
827 }
828 
829 /*
830  * Find symbol interpreter - filters.
831  * This function is called when the symbols from a shared object should
832  * be resolved from the shared objects filtees instead of from within itself.
833  *
834  * A symbol name of 0 is used to trigger filtee loading.
835  */
836 static Sym *
837 _elf_lookup_filtee(Slookup *slp, Rt_map **dlmp, uint_t *binfo, uint_t ndx,
838     int *in_nfavl)
839 {
840 	const char	*name = slp->sl_name, *filtees;
841 	Rt_map		*clmp = slp->sl_cmap;
842 	Rt_map		*ilmp = slp->sl_imap;
843 	Pdesc		*pdp;
844 	int		any;
845 	Dyninfo		*dip = &DYNINFO(ilmp)[ndx];
846 	Lm_list		*lml = LIST(ilmp);
847 	Aliste		idx;
848 
849 	/*
850 	 * Indicate that the filter has been used.  If a binding already exists
851 	 * to the caller, indicate that this object is referenced.  This insures
852 	 * we don't generate false unreferenced diagnostics from ldd -u/U or
853 	 * debugging.  Don't create a binding regardless, as this filter may
854 	 * have been dlopen()'ed.
855 	 */
856 	if (name && (ilmp != clmp)) {
857 		Word	tracing = (LIST(clmp)->lm_flags &
858 		    (LML_FLG_TRC_UNREF | LML_FLG_TRC_UNUSED));
859 
860 		if (tracing || DBG_ENABLED) {
861 			Bnd_desc 	*bdp;
862 			Aliste		idx;
863 
864 			FLAGS1(ilmp) |= FL1_RT_USED;
865 
866 			if ((tracing & LML_FLG_TRC_UNREF) || DBG_ENABLED) {
867 				for (APLIST_TRAVERSE(CALLERS(ilmp), idx, bdp)) {
868 					if (bdp->b_caller == clmp) {
869 						bdp->b_flags |= BND_REFER;
870 						break;
871 					}
872 				}
873 			}
874 		}
875 	}
876 
877 	/*
878 	 * If this is the first call to process this filter, establish the
879 	 * filtee list.  If a configuration file exists, determine if any
880 	 * filtee associations for this filter, and its filtee reference, are
881 	 * defined.  Otherwise, process the filtee reference.  Any token
882 	 * expansion is also completed at this point (i.e., $PLATFORM).
883 	 */
884 	filtees = (char *)STRTAB(ilmp) + DYN(ilmp)[ndx].d_un.d_val;
885 	if (dip->di_info == NULL) {
886 		if (rtld_flags2 & RT_FL2_FLTCFG)
887 			elf_config_flt(lml, PATHNAME(ilmp), filtees,
888 			    (Alist **)&dip->di_info, AL_CNT_FILTEES);
889 
890 		if (dip->di_info == NULL) {
891 			DBG_CALL(Dbg_file_filter(lml, NAME(ilmp), filtees, 0));
892 			if ((lml->lm_flags &
893 			    (LML_FLG_TRC_VERBOSE | LML_FLG_TRC_SEARCH)) &&
894 			    ((FLAGS1(ilmp) & FL1_RT_LDDSTUB) == 0))
895 				(void) printf(MSG_INTL(MSG_LDD_FIL_FILTER),
896 				    NAME(ilmp), filtees);
897 
898 			if (expand_paths(ilmp, filtees, (Alist **)&dip->di_info,
899 			    AL_CNT_FILTEES, 0, 0) == 0) {
900 				elf_disable_filtee(ilmp, dip);
901 				return (NULL);
902 			}
903 		}
904 	}
905 
906 	/*
907 	 * Traverse the filtee list, dlopen()'ing any objects specified and
908 	 * using their group handle to lookup the symbol.
909 	 */
910 	any = 0;
911 	for (ALIST_TRAVERSE((Alist *)dip->di_info, idx, pdp)) {
912 		int	mode;
913 		Grp_hdl	*ghp;
914 		Rt_map	*nlmp = NULL;
915 
916 		if (pdp->pd_plen == 0)
917 			continue;
918 
919 		/*
920 		 * Establish the mode of the filtee from the filter.  As filtees
921 		 * are loaded via a dlopen(), make sure that RTLD_GROUP is set
922 		 * and the filtees aren't global.  It would be nice to have
923 		 * RTLD_FIRST used here also, but as filters got out long before
924 		 * RTLD_FIRST was introduced it's a little too late now.
925 		 */
926 		mode = MODE(ilmp) | RTLD_GROUP;
927 		mode &= ~RTLD_GLOBAL;
928 
929 		/*
930 		 * Insure that any auxiliary filter can locate symbols from its
931 		 * caller.
932 		 */
933 		if (dip->di_flags & FLG_DI_AUXFLTR)
934 			mode |= RTLD_PARENT;
935 
936 		/*
937 		 * Process any hardware capability directory.  Establish a new
938 		 * link-map control list from which to analyze any newly added
939 		 * objects.
940 		 */
941 		if ((pdp->pd_info == NULL) && (pdp->pd_flags & PD_TKN_HWCAP)) {
942 			const char	*dir = pdp->pd_pname;
943 			Aliste		lmco;
944 
945 			/*
946 			 * Establish a link-map control list for this request.
947 			 */
948 			if ((lmco = create_cntl(lml, 0)) == NULL)
949 				return (NULL);
950 
951 			/*
952 			 * Determine the hardware capability filtees.  If none
953 			 * can be found, provide suitable diagnostics.
954 			 */
955 			DBG_CALL(Dbg_cap_hw_filter(lml, dir, ilmp));
956 			if (hwcap_filtees((Alist **)&dip->di_info, idx, dir,
957 			    lmco, ilmp, filtees, mode,
958 			    (FLG_RT_PUBHDL | FLG_RT_HWCAP), in_nfavl) == 0) {
959 				if ((lml->lm_flags & LML_FLG_TRC_ENABLE) &&
960 				    (dip->di_flags & FLG_DI_AUXFLTR) &&
961 				    (rtld_flags & RT_FL_WARNFLTR)) {
962 					(void) printf(
963 					    MSG_INTL(MSG_LDD_HWCAP_NFOUND),
964 					    dir);
965 				}
966 				DBG_CALL(Dbg_cap_hw_filter(lml, dir, 0));
967 			}
968 
969 			/*
970 			 * Re-establish the originating path name descriptor, as
971 			 * the expansion of hardware capabilities filtees may
972 			 * have re-allocated the controlling Alist.  Mark this
973 			 * original pathname descriptor as unused so that the
974 			 * descriptor isn't revisited for processing.  Any real
975 			 * hardware capabilities filtees have been added as new
976 			 * pathname descriptors following this descriptor.
977 			 */
978 			pdp = alist_item((Alist *)dip->di_info, idx);
979 			pdp->pd_flags &= ~PD_TKN_HWCAP;
980 			pdp->pd_plen = 0;
981 
982 			/*
983 			 * Now that any hardware capability objects have been
984 			 * processed, remove any temporary link-map control
985 			 * list.
986 			 */
987 			if (lmco != ALIST_OFF_DATA)
988 				remove_cntl(lml, lmco);
989 		}
990 
991 		if (pdp->pd_plen == 0)
992 			continue;
993 
994 		/*
995 		 * Process an individual filtee.
996 		 */
997 		if (pdp->pd_info == NULL) {
998 			const char	*filtee = pdp->pd_pname;
999 			int		audit = 0;
1000 
1001 			DBG_CALL(Dbg_file_filtee(lml, NAME(ilmp), filtee, 0));
1002 
1003 			ghp = NULL;
1004 
1005 			/*
1006 			 * Determine if the reference link map is already
1007 			 * loaded.  As an optimization compare the filtee with
1008 			 * our interpretor.  The most common filter is
1009 			 * libdl.so.1, which is a filter on ld.so.1.
1010 			 */
1011 #if	defined(_ELF64)
1012 			if (strcmp(filtee, MSG_ORIG(MSG_PTH_RTLD_64)) == 0) {
1013 #else
1014 			if (strcmp(filtee, MSG_ORIG(MSG_PTH_RTLD)) == 0) {
1015 #endif
1016 				uint_t	hflags, rdflags, cdflags;
1017 
1018 				/*
1019 				 * Establish any flags for the handle (Grp_hdl).
1020 				 *
1021 				 *  -	This is a special, public, ld.so.1
1022 				 *	handle.
1023 				 *  -	Only the first object on this handle
1024 				 *	can supply symbols.
1025 				 *  -	This handle provides a filtee.
1026 				 *
1027 				 * Essentially, this handle allows a caller to
1028 				 * reference the dl*() family of interfaces from
1029 				 * ld.so.1.
1030 				 */
1031 				hflags = (GPH_PUBLIC | GPH_LDSO |
1032 				    GPH_FIRST | GPH_FILTEE);
1033 
1034 				/*
1035 				 * Establish the flags for the referenced
1036 				 * dependency descriptor (Grp_desc).
1037 				 *
1038 				 *  -	ld.so.1 is available for dlsym().
1039 				 *  -	ld.so.1 is available to relocate
1040 				 *	against.
1041 				 *  -	There's no need to add an dependencies
1042 				 * 	to this handle.
1043 				 */
1044 				rdflags = (GPD_DLSYM | GPD_RELOC);
1045 
1046 				/*
1047 				 * Establish the flags for this callers
1048 				 * dependency descriptor (Grp_desc).
1049 				 *
1050 				 *  -   The explicit creation of a handle
1051 				 *	creates a descriptor for the referenced
1052 				 *	object and the parent (caller).
1053 				 */
1054 				cdflags = GPD_PARENT;
1055 
1056 				nlmp = lml_rtld.lm_head;
1057 				if ((ghp = hdl_create(&lml_rtld, nlmp, ilmp,
1058 				    hflags, rdflags, cdflags)) == NULL)
1059 					nlmp = NULL;
1060 
1061 				/*
1062 				 * Establish the filter handle to prevent any
1063 				 * recursion.
1064 				 */
1065 				if (nlmp && ghp)
1066 					pdp->pd_info = (void *)ghp;
1067 
1068 				/*
1069 				 * Audit the filter/filtee established.  Ignore
1070 				 * any return from the auditor, as we can't
1071 				 * allow ignore filtering to ld.so.1, otherwise
1072 				 * nothing is going to work.
1073 				 */
1074 				if (nlmp && ((lml->lm_tflags | AFLAGS(ilmp)) &
1075 				    LML_TFLG_AUD_OBJFILTER))
1076 					(void) audit_objfilter(ilmp, filtees,
1077 					    nlmp, 0);
1078 
1079 			} else {
1080 				Rej_desc	rej = { 0 };
1081 				Fdesc		fd = { 0 };
1082 				Aliste		lmco;
1083 
1084 				/*
1085 				 * Trace the inspection of this file, determine
1086 				 * any auditor substitution, and seed the file
1087 				 * descriptor with the originating name.
1088 				 */
1089 				if (load_trace(lml, pdp, clmp, &fd) == NULL)
1090 					continue;
1091 
1092 				/*
1093 				 * Establish a link-map control list for this
1094 				 * request.
1095 				 */
1096 				if ((lmco = create_cntl(lml, 0)) == NULL)
1097 					return (NULL);
1098 
1099 				/*
1100 				 * Locate and load the filtee.
1101 				 */
1102 				if ((nlmp = load_path(lml, lmco, ilmp, mode,
1103 				    FLG_RT_PUBHDL, &ghp, &fd, &rej,
1104 				    in_nfavl)) == NULL)
1105 					file_notfound(LIST(ilmp), filtee, ilmp,
1106 					    FLG_RT_PUBHDL, &rej);
1107 
1108 				filtee = pdp->pd_pname;
1109 
1110 				/*
1111 				 * Establish the filter handle to prevent any
1112 				 * recursion.
1113 				 */
1114 				if (nlmp && ghp) {
1115 					ghp->gh_flags |= GPH_FILTEE;
1116 					pdp->pd_info = (void *)ghp;
1117 
1118 					FLAGS1(nlmp) |= FL1_RT_USED;
1119 				}
1120 
1121 				/*
1122 				 * Audit the filter/filtee established.  A
1123 				 * return of 0 indicates the auditor wishes to
1124 				 * ignore this filtee.
1125 				 */
1126 				if (nlmp && ((lml->lm_tflags | FLAGS1(ilmp)) &
1127 				    LML_TFLG_AUD_OBJFILTER)) {
1128 					if (audit_objfilter(ilmp, filtees,
1129 					    nlmp, 0) == 0) {
1130 						audit = 1;
1131 						nlmp = NULL;
1132 					}
1133 				}
1134 
1135 				/*
1136 				 * Finish processing the objects associated with
1137 				 * this request.  Create an association between
1138 				 * this object and the originating filter to
1139 				 * provide sufficient information to tear down
1140 				 * this filtee if necessary.
1141 				 */
1142 				if (nlmp && ghp && (((nlmp = analyze_lmc(lml,
1143 				    lmco, nlmp, in_nfavl)) == NULL) ||
1144 				    (relocate_lmc(lml, lmco, ilmp, nlmp,
1145 				    in_nfavl) == 0)))
1146 					nlmp = NULL;
1147 
1148 				/*
1149 				 * If the filtee has been successfully
1150 				 * processed, then create an association
1151 				 * between the filter and filtee.  This
1152 				 * association provides sufficient information
1153 				 * to tear down the filter and filtee if
1154 				 * necessary.
1155 				 */
1156 				DBG_CALL(Dbg_file_hdl_title(DBG_HDL_ADD));
1157 				if (nlmp && ghp && (hdl_add(ghp, ilmp,
1158 				    GPD_FILTER, NULL) == NULL))
1159 					nlmp = NULL;
1160 
1161 				/*
1162 				 * Generate a diagnostic if the filtee couldn't
1163 				 * be loaded.
1164 				 */
1165 				if (nlmp == NULL)
1166 					DBG_CALL(Dbg_file_filtee(lml, 0, filtee,
1167 					    audit));
1168 
1169 				/*
1170 				 * If this filtee loading has failed, and we've
1171 				 * created a new link-map control list to which
1172 				 * this request has added objects, then remove
1173 				 * all the objects that have been associated to
1174 				 * this request.
1175 				 */
1176 				if ((nlmp == NULL) && (lmco != ALIST_OFF_DATA))
1177 					remove_lmc(lml, clmp, lmco, name);
1178 
1179 				/*
1180 				 * Remove any temporary link-map control list.
1181 				 */
1182 				if (lmco != ALIST_OFF_DATA)
1183 					remove_cntl(lml, lmco);
1184 			}
1185 
1186 			/*
1187 			 * If the filtee couldn't be loaded, null out the
1188 			 * path name descriptor entry, and continue the search.
1189 			 * Otherwise, the group handle is retained for future
1190 			 * symbol searches.
1191 			 */
1192 			if (nlmp == NULL) {
1193 				pdp->pd_info = NULL;
1194 				pdp->pd_plen = 0;
1195 				continue;
1196 			}
1197 		}
1198 
1199 		ghp = (Grp_hdl *)pdp->pd_info;
1200 
1201 		/*
1202 		 * If we're just here to trigger filtee loading skip the symbol
1203 		 * lookup so we'll continue looking for additional filtees.
1204 		 */
1205 		if (name) {
1206 			Grp_desc	*gdp;
1207 			Sym		*sym = NULL;
1208 			Aliste		idx;
1209 			Slookup		sl = *slp;
1210 
1211 			sl.sl_flags |= LKUP_FIRST;
1212 			any++;
1213 
1214 			/*
1215 			 * Look for the symbol in the handles dependencies.
1216 			 */
1217 			for (ALIST_TRAVERSE(ghp->gh_depends, idx, gdp)) {
1218 				if ((gdp->gd_flags & GPD_DLSYM) == 0)
1219 					continue;
1220 
1221 				/*
1222 				 * If our parent is a dependency don't look at
1223 				 * it (otherwise we are in a recursive loop).
1224 				 * This situation can occur with auxiliary
1225 				 * filters if the filtee has a dependency on the
1226 				 * filter.  This dependency isn't necessary as
1227 				 * auxiliary filters are opened RTLD_PARENT, but
1228 				 * users may still unknowingly add an explicit
1229 				 * dependency to the parent.
1230 				 */
1231 				if ((sl.sl_imap = gdp->gd_depend) == ilmp)
1232 					continue;
1233 
1234 				if (((sym = SYMINTP(sl.sl_imap)(&sl, dlmp,
1235 				    binfo, in_nfavl)) != NULL) ||
1236 				    (ghp->gh_flags & GPH_FIRST))
1237 					break;
1238 			}
1239 
1240 			/*
1241 			 * If a symbol has been found, indicate the binding
1242 			 * and return the symbol.
1243 			 */
1244 			if (sym) {
1245 				*binfo |= DBG_BINFO_FILTEE;
1246 				return (sym);
1247 			}
1248 		}
1249 
1250 		/*
1251 		 * If this object is tagged to terminate filtee processing we're
1252 		 * done.
1253 		 */
1254 		if (FLAGS1(ghp->gh_ownlmp) & FL1_RT_ENDFILTE)
1255 			break;
1256 	}
1257 
1258 	/*
1259 	 * If we're just here to trigger filtee loading then we're done.
1260 	 */
1261 	if (name == NULL)
1262 		return (NULL);
1263 
1264 	/*
1265 	 * If no filtees have been found for a filter, clean up any path name
1266 	 * descriptors and disable their search completely.  For auxiliary
1267 	 * filters we can reselect the symbol search function so that we never
1268 	 * enter this routine again for this object.  For standard filters we
1269 	 * use the null symbol routine.
1270 	 */
1271 	if (any == 0) {
1272 		remove_plist((Alist **)&(dip->di_info), 1);
1273 		elf_disable_filtee(ilmp, dip);
1274 		return (NULL);
1275 	}
1276 
1277 	return (NULL);
1278 }
1279 
1280 /*
1281  * Focal point for disabling error messages for auxiliary filters.  As an
1282  * auxiliary filter allows for filtee use, but provides a fallback should a
1283  * filtee not exist (or fail to load), any errors generated as a consequence of
1284  * trying to load the filtees are typically suppressed.  Setting RT_FL_SILENCERR
1285  * suppresses errors generated by eprint(), but insures a debug diagnostic is
1286  * produced.  ldd(1) employs printf(), and here, the selection of whether to
1287  * print a diagnostic in regards to auxiliary filters is a little more complex.
1288  *
1289  *   -	The determination of whether to produce an ldd message, or a fatal
1290  *	error message is driven by LML_FLG_TRC_ENABLE.
1291  *   -	More detailed ldd messages may also be driven off of LML_FLG_TRC_WARN,
1292  *	(ldd -d/-r), LML_FLG_TRC_VERBOSE (ldd -v), LML_FLG_TRC_SEARCH (ldd -s),
1293  *	and LML_FLG_TRC_UNREF/LML_FLG_TRC_UNUSED (ldd -U/-u).
1294  *
1295  *   -	If the calling object is lddstub, then several classes of message are
1296  *	suppressed.  The user isn't trying to diagnose lddstub, this is simply
1297  *	a stub executable employed to preload a user specified library against.
1298  *
1299  *   -	If RT_FL_SILENCERR is in effect then any generic ldd() messages should
1300  *	be suppressed.  All detailed ldd messages should still be produced.
1301  */
1302 Sym *
1303 elf_lookup_filtee(Slookup *slp, Rt_map **dlmp, uint_t *binfo, uint_t ndx,
1304     int *in_nfavl)
1305 {
1306 	Sym	*sym;
1307 	Dyninfo	*dip = &DYNINFO(slp->sl_imap)[ndx];
1308 	int	silent = 0;
1309 
1310 	/*
1311 	 * Make sure this entry is still acting as a filter.  We may have tried
1312 	 * to process this previously, and disabled it if the filtee couldn't
1313 	 * be processed.  However, other entries may provide different filtees
1314 	 * that are yet to be completed.
1315 	 */
1316 	if (dip->di_flags == 0)
1317 		return (NULL);
1318 
1319 	/*
1320 	 * Indicate whether an error message is required should this filtee not
1321 	 * be found, based on the type of filter.
1322 	 */
1323 	if ((dip->di_flags & FLG_DI_AUXFLTR) &&
1324 	    ((rtld_flags & (RT_FL_WARNFLTR | RT_FL_SILENCERR)) == 0)) {
1325 		rtld_flags |= RT_FL_SILENCERR;
1326 		silent = 1;
1327 	}
1328 
1329 	sym = _elf_lookup_filtee(slp, dlmp, binfo, ndx, in_nfavl);
1330 
1331 	if (silent)
1332 		rtld_flags &= ~RT_FL_SILENCERR;
1333 
1334 	return (sym);
1335 }
1336 
1337 /*
1338  * Compute the elf hash value (as defined in the ELF access library).
1339  * The form of the hash table is:
1340  *
1341  *	|--------------|
1342  *	| # of buckets |
1343  *	|--------------|
1344  *	| # of chains  |
1345  *	|--------------|
1346  *	|   bucket[]   |
1347  *	|--------------|
1348  *	|   chain[]    |
1349  *	|--------------|
1350  */
1351 ulong_t
1352 elf_hash(const char *name)
1353 {
1354 	uint_t	hval = 0;
1355 
1356 	while (*name) {
1357 		uint_t	g;
1358 		hval = (hval << 4) + *name++;
1359 		if ((g = (hval & 0xf0000000)) != 0)
1360 			hval ^= g >> 24;
1361 		hval &= ~g;
1362 	}
1363 	return ((ulong_t)hval);
1364 }
1365 
1366 /*
1367  * If flag argument has LKUP_SPEC set, we treat undefined symbols of type
1368  * function specially in the executable - if they have a value, even though
1369  * undefined, we use that value.  This allows us to associate all references
1370  * to a function's address to a single place in the process: the plt entry
1371  * for that function in the executable.  Calls to lookup from plt binding
1372  * routines do NOT set LKUP_SPEC in the flag.
1373  */
1374 Sym *
1375 elf_find_sym(Slookup *slp, Rt_map **dlmp, uint_t *binfo, int *in_nfavl)
1376 {
1377 	const char	*name = slp->sl_name;
1378 	Rt_map		*ilmp = slp->sl_imap;
1379 	ulong_t		hash = slp->sl_hash;
1380 	uint_t		ndx, htmp, buckets, *chainptr;
1381 	Sym		*sym, *symtabptr;
1382 	char		*strtabptr, *strtabname;
1383 	uint_t		flags1;
1384 	Syminfo		*sip;
1385 
1386 	/*
1387 	 * If we're only here to establish a symbols index, skip the diagnostic
1388 	 * used to trace a symbol search.
1389 	 */
1390 	if ((slp->sl_flags & LKUP_SYMNDX) == 0)
1391 		DBG_CALL(Dbg_syms_lookup(ilmp, name, MSG_ORIG(MSG_STR_ELF)));
1392 
1393 	if (HASH(ilmp) == NULL)
1394 		return (NULL);
1395 
1396 	buckets = HASH(ilmp)[0];
1397 	/* LINTED */
1398 	htmp = (uint_t)hash % buckets;
1399 
1400 	/*
1401 	 * Get the first symbol on hash chain and initialize the string
1402 	 * and symbol table pointers.
1403 	 */
1404 	if ((ndx = HASH(ilmp)[htmp + 2]) == 0)
1405 		return (NULL);
1406 
1407 	chainptr = HASH(ilmp) + 2 + buckets;
1408 	strtabptr = STRTAB(ilmp);
1409 	symtabptr = SYMTAB(ilmp);
1410 
1411 	while (ndx) {
1412 		sym = symtabptr + ndx;
1413 		strtabname = strtabptr + sym->st_name;
1414 
1415 		/*
1416 		 * Compare the symbol found with the name required.  If the
1417 		 * names don't match continue with the next hash entry.
1418 		 */
1419 		if ((*strtabname++ != *name) || strcmp(strtabname, &name[1])) {
1420 			if ((ndx = chainptr[ndx]) != 0)
1421 				continue;
1422 			return (NULL);
1423 		}
1424 
1425 		/*
1426 		 * The Solaris ld does not put DT_VERSYM in the dynamic
1427 		 * section, but the GNU ld does. The GNU runtime linker
1428 		 * interprets the top bit of the 16-bit Versym value
1429 		 * (0x8000) as the "hidden" bit. If this bit is set,
1430 		 * the linker is supposed to act as if that symbol does
1431 		 * not exist. The hidden bit supports their versioning
1432 		 * scheme, which allows multiple incompatible functions
1433 		 * with the same name to exist at different versions
1434 		 * within an object. The Solaris linker does not support this
1435 		 * mechanism, or the model of interface evolution that
1436 		 * it allows, but we honor the hidden bit in GNU ld
1437 		 * produced objects in order to interoperate with them.
1438 		 */
1439 		if ((VERSYM(ilmp) != NULL) &&
1440 		    ((VERSYM(ilmp)[ndx] & 0x8000) != 0)) {
1441 			DBG_CALL(Dbg_syms_ignore_gnuver(ilmp, name,
1442 			    ndx, VERSYM(ilmp)[ndx]));
1443 			if ((ndx = chainptr[ndx]) != 0)
1444 				continue;
1445 			return (NULL);
1446 		}
1447 
1448 		/*
1449 		 * If we're only here to establish a symbols index, we're done.
1450 		 */
1451 		if (slp->sl_flags & LKUP_SYMNDX)
1452 			return (sym);
1453 
1454 		/*
1455 		 * If we find a match and the symbol is defined, return the
1456 		 * symbol pointer and the link map in which it was found.
1457 		 */
1458 		if (sym->st_shndx != SHN_UNDEF) {
1459 			*dlmp = ilmp;
1460 			*binfo |= DBG_BINFO_FOUND;
1461 			if ((FLAGS(ilmp) & FLG_RT_OBJINTPO) ||
1462 			    ((FLAGS(ilmp) & FLG_RT_SYMINTPO) &&
1463 			    is_sym_interposer(ilmp, sym)))
1464 				*binfo |= DBG_BINFO_INTERPOSE;
1465 			break;
1466 
1467 		/*
1468 		 * If we find a match and the symbol is undefined, the
1469 		 * symbol type is a function, and the value of the symbol
1470 		 * is non zero, then this is a special case.  This allows
1471 		 * the resolution of a function address to the plt[] entry.
1472 		 * See SPARC ABI, Dynamic Linking, Function Addresses for
1473 		 * more details.
1474 		 */
1475 		} else if ((slp->sl_flags & LKUP_SPEC) &&
1476 		    (FLAGS(ilmp) & FLG_RT_ISMAIN) && (sym->st_value != 0) &&
1477 		    (ELF_ST_TYPE(sym->st_info) == STT_FUNC)) {
1478 			*dlmp = ilmp;
1479 			*binfo |= (DBG_BINFO_FOUND | DBG_BINFO_PLTADDR);
1480 			if ((FLAGS(ilmp) & FLG_RT_OBJINTPO) ||
1481 			    ((FLAGS(ilmp) & FLG_RT_SYMINTPO) &&
1482 			    is_sym_interposer(ilmp, sym)))
1483 				*binfo |= DBG_BINFO_INTERPOSE;
1484 			return (sym);
1485 		}
1486 
1487 		/*
1488 		 * Undefined symbol.
1489 		 */
1490 		return (NULL);
1491 	}
1492 
1493 	/*
1494 	 * We've found a match.  Determine if the defining object contains
1495 	 * symbol binding information.
1496 	 */
1497 	if ((sip = SYMINFO(ilmp)) != NULL)
1498 		sip += ndx;
1499 
1500 	/*
1501 	 * If this definition is a singleton, and we haven't followed a default
1502 	 * symbol search knowing that we're looking for a singleton (presumably
1503 	 * because the symbol definition has been changed since the referring
1504 	 * object was built), then reject this binding so that the caller can
1505 	 * fall back to a standard symbol search.
1506 	 */
1507 	if ((ELF_ST_VISIBILITY(sym->st_other) == STV_SINGLETON) &&
1508 	    (((slp->sl_flags & LKUP_STANDARD) == 0) ||
1509 	    (((slp->sl_flags & LKUP_SINGLETON) == 0) &&
1510 	    (LIST(ilmp)->lm_flags & LML_FLG_GROUPSEXIST)))) {
1511 		DBG_CALL(Dbg_bind_reject(slp->sl_cmap, ilmp, name,
1512 		    DBG_BNDREJ_SINGLE));
1513 		*binfo |= BINFO_REJSINGLE;
1514 		*binfo &= ~DBG_BINFO_MSK;
1515 		return (NULL);
1516 	}
1517 
1518 	/*
1519 	 * If this is a direct binding request, but the symbol definition has
1520 	 * disabled directly binding to it (presumably because the symbol
1521 	 * definition has been changed since the referring object was built),
1522 	 * reject this binding so that the caller can fall back to a standard
1523 	 * symbol search.
1524 	 */
1525 	if (sip && (slp->sl_flags & LKUP_DIRECT) &&
1526 	    (sip->si_flags & SYMINFO_FLG_NOEXTDIRECT)) {
1527 		DBG_CALL(Dbg_bind_reject(slp->sl_cmap, ilmp, name,
1528 		    DBG_BNDREJ_DIRECT));
1529 		*binfo |= BINFO_REJDIRECT;
1530 		*binfo &= ~DBG_BINFO_MSK;
1531 		return (NULL);
1532 	}
1533 
1534 	/*
1535 	 * If this is a binding request within an RTLD_GROUP family, and the
1536 	 * symbol has disabled directly binding to it, reject this binding so
1537 	 * that the caller can fall back to a standard symbol search.
1538 	 *
1539 	 * Effectively, an RTLD_GROUP family achieves what can now be
1540 	 * established with direct bindings.  However, various symbols have
1541 	 * been tagged as inappropriate for direct binding to (ie. libc:malloc).
1542 	 *
1543 	 * A symbol marked as no-direct cannot be used within a group without
1544 	 * first ensuring that the symbol has not been interposed upon outside
1545 	 * of the group.  A common example occurs when users implement their own
1546 	 * version of malloc() in the executable.  Such a malloc() interposes on
1547 	 * the libc:malloc, and this interposition must be honored within the
1548 	 * group as well.
1549 	 *
1550 	 * Following any rejection, LKUP_WORLD is established as a means of
1551 	 * overriding this test as we return to a standard search.
1552 	 */
1553 	if (sip && (sip->si_flags & SYMINFO_FLG_NOEXTDIRECT) &&
1554 	    ((MODE(slp->sl_cmap) & (RTLD_GROUP | RTLD_WORLD)) == RTLD_GROUP) &&
1555 	    ((slp->sl_flags & LKUP_WORLD) == 0)) {
1556 		DBG_CALL(Dbg_bind_reject(slp->sl_cmap, ilmp, name,
1557 		    DBG_BNDREJ_GROUP));
1558 		*binfo |= BINFO_REJGROUP;
1559 		*binfo &= ~DBG_BINFO_MSK;
1560 		return (NULL);
1561 	}
1562 
1563 	/*
1564 	 * Determine whether this object is acting as a filter.
1565 	 */
1566 	if (((flags1 = FLAGS1(ilmp)) & MSK_RT_FILTER) == 0)
1567 		return (sym);
1568 
1569 	/*
1570 	 * Determine if this object offers per-symbol filtering, and if so,
1571 	 * whether this symbol references a filtee.
1572 	 */
1573 	if (sip && (flags1 & (FL1_RT_SYMSFLTR | FL1_RT_SYMAFLTR))) {
1574 		/*
1575 		 * If this is a standard filter reference, and no standard
1576 		 * filtees remain to be inspected, we're done.  If this is an
1577 		 * auxiliary filter reference, and no auxiliary filtees remain,
1578 		 * we'll fall through in case any object filtering is available.
1579 		 */
1580 		if ((sip->si_flags & SYMINFO_FLG_FILTER) &&
1581 		    (SYMSFLTRCNT(ilmp) == 0))
1582 			return (NULL);
1583 
1584 		if ((sip->si_flags & SYMINFO_FLG_FILTER) ||
1585 		    ((sip->si_flags & SYMINFO_FLG_AUXILIARY) &&
1586 		    SYMAFLTRCNT(ilmp))) {
1587 			Sym	*fsym;
1588 
1589 			/*
1590 			 * This symbol has an associated filtee.  Lookup the
1591 			 * symbol in the filtee, and if it is found return it.
1592 			 * If the symbol doesn't exist, and this is a standard
1593 			 * filter, return an error, otherwise fall through to
1594 			 * catch any object filtering that may be available.
1595 			 */
1596 			if ((fsym = elf_lookup_filtee(slp, dlmp, binfo,
1597 			    sip->si_boundto, in_nfavl)) != NULL)
1598 				return (fsym);
1599 			if (sip->si_flags & SYMINFO_FLG_FILTER)
1600 				return (NULL);
1601 		}
1602 	}
1603 
1604 	/*
1605 	 * Determine if this object provides global filtering.
1606 	 */
1607 	if (flags1 & (FL1_RT_OBJSFLTR | FL1_RT_OBJAFLTR)) {
1608 		Sym	*fsym;
1609 
1610 		if (OBJFLTRNDX(ilmp) != FLTR_DISABLED) {
1611 			/*
1612 			 * This object has an associated filtee.  Lookup the
1613 			 * symbol in the filtee, and if it is found return it.
1614 			 * If the symbol doesn't exist, and this is a standard
1615 			 * filter, return and error, otherwise return the symbol
1616 			 * within the filter itself.
1617 			 */
1618 			if ((fsym = elf_lookup_filtee(slp, dlmp, binfo,
1619 			    OBJFLTRNDX(ilmp), in_nfavl)) != NULL)
1620 				return (fsym);
1621 		}
1622 
1623 		if (flags1 & FL1_RT_OBJSFLTR)
1624 			return (NULL);
1625 	}
1626 	return (sym);
1627 }
1628 
1629 /*
1630  * Create a new Rt_map structure for an ELF object and initialize
1631  * all values.
1632  */
1633 Rt_map *
1634 elf_new_lmp(Lm_list *lml, Aliste lmco, Fdesc *fdp, Addr addr, size_t msize,
1635     void *odyn, int *in_nfavl)
1636 {
1637 	const char	*name = fdp->fd_nname;
1638 	Rt_map		*lmp;
1639 	Ehdr		*ehdr = (Ehdr *)addr;
1640 	Phdr		*phdr, *tphdr = NULL, *dphdr = NULL, *uphdr = NULL;
1641 	Dyn		*dyn = (Dyn *)odyn;
1642 	Cap		*cap = NULL;
1643 	int		ndx;
1644 	Addr		base, fltr = 0, audit = 0, cfile = 0, crle = 0;
1645 	Xword		rpath = 0;
1646 	size_t		lmsz, rtsz, epsz, dynsz = 0;
1647 	uint_t		dyncnt = 0;
1648 
1649 	DBG_CALL(Dbg_file_elf(lml, name, addr, msize, lml->lm_lmidstr, lmco));
1650 
1651 	/*
1652 	 * If this is a shared object, the base address of the shared object is
1653 	 * added to all address values defined within the object.  Otherwise, if
1654 	 * this is an executable, all object addresses are used as is.
1655 	 */
1656 	if (ehdr->e_type == ET_EXEC)
1657 		base = 0;
1658 	else
1659 		base = addr;
1660 
1661 	/*
1662 	 * Traverse the program header table, picking off required items.  This
1663 	 * traversal also provides for the sizing of the PT_DYNAMIC section.
1664 	 */
1665 	phdr = (Phdr *)((uintptr_t)ehdr + ehdr->e_phoff);
1666 	for (ndx = 0; ndx < (int)ehdr->e_phnum; ndx++,
1667 	    phdr = (Phdr *)((uintptr_t)phdr + ehdr->e_phentsize)) {
1668 		switch (phdr->p_type) {
1669 		case PT_DYNAMIC:
1670 			dphdr = phdr;
1671 			dyn = (Dyn *)((uintptr_t)phdr->p_vaddr + base);
1672 			break;
1673 		case PT_TLS:
1674 			tphdr = phdr;
1675 			break;
1676 		case PT_SUNWCAP:
1677 			cap = (Cap *)((uintptr_t)phdr->p_vaddr + base);
1678 			break;
1679 		case PT_SUNW_UNWIND:
1680 		case PT_SUNW_EH_FRAME:
1681 			uphdr = phdr;
1682 			break;
1683 		default:
1684 			break;
1685 		}
1686 	}
1687 
1688 	/*
1689 	 * Determine the number of PT_DYNAMIC entries for the DYNINFO()
1690 	 * allocation.  Sadly, this is a little larger than we really need,
1691 	 * as there are typically padding DT_NULL entries.  However, adding
1692 	 * this data to the initial link-map allocation is a win.
1693 	 */
1694 	if (dyn) {
1695 		dyncnt = dphdr->p_filesz / sizeof (Dyn);
1696 		dynsz = dyncnt * sizeof (Dyninfo);
1697 	}
1698 
1699 	/*
1700 	 * Allocate space for the link-map, private elf information, and
1701 	 * DYNINFO() data.  Once these are allocated and initialized,
1702 	 * remove_so(0, lmp) can be used to tear down the link-map allocation
1703 	 * should any failures occur.
1704 	 */
1705 	rtsz = S_DROUND(sizeof (Rt_map));
1706 	epsz = S_DROUND(sizeof (Rt_elfp));
1707 	lmsz = rtsz + epsz + dynsz;
1708 	if ((lmp = calloc(lmsz, 1)) == NULL)
1709 		return (NULL);
1710 	ELFPRV(lmp) = (void *)((uintptr_t)lmp + rtsz);
1711 	DYNINFO(lmp) = (Dyninfo *)((uintptr_t)lmp + rtsz + epsz);
1712 	LMSIZE(lmp) = lmsz;
1713 
1714 	/*
1715 	 * All fields not filled in were set to 0 by calloc.
1716 	 */
1717 	NAME(lmp) = (char *)name;
1718 	ADDR(lmp) = addr;
1719 	MSIZE(lmp) = msize;
1720 	SYMINTP(lmp) = elf_find_sym;
1721 	FCT(lmp) = &elf_fct;
1722 	LIST(lmp) = lml;
1723 	OBJFLTRNDX(lmp) = FLTR_DISABLED;
1724 	SORTVAL(lmp) = -1;
1725 	DYN(lmp) = dyn;
1726 	DYNINFOCNT(lmp) = dyncnt;
1727 	PTUNWIND(lmp) = uphdr;
1728 
1729 	if (ehdr->e_type == ET_EXEC)
1730 		FLAGS(lmp) |= FLG_RT_FIXED;
1731 
1732 	/*
1733 	 * Fill in rest of the link map entries with information from the file's
1734 	 * dynamic structure.
1735 	 */
1736 	if (dyn) {
1737 		uint_t		dynndx = 0;
1738 		Xword		pltpadsz = 0;
1739 		Rti_desc	*rti;
1740 
1741 		/* CSTYLED */
1742 		for ( ; dyn->d_tag != DT_NULL; ++dyn, dynndx++) {
1743 			switch ((Xword)dyn->d_tag) {
1744 			case DT_SYMTAB:
1745 				SYMTAB(lmp) = (void *)(dyn->d_un.d_ptr + base);
1746 				break;
1747 			case DT_SUNW_SYMTAB:
1748 				SUNWSYMTAB(lmp) =
1749 				    (void *)(dyn->d_un.d_ptr + base);
1750 				break;
1751 			case DT_SUNW_SYMSZ:
1752 				SUNWSYMSZ(lmp) = dyn->d_un.d_val;
1753 				break;
1754 			case DT_STRTAB:
1755 				STRTAB(lmp) = (void *)(dyn->d_un.d_ptr + base);
1756 				break;
1757 			case DT_SYMENT:
1758 				SYMENT(lmp) = dyn->d_un.d_val;
1759 				break;
1760 			case DT_FEATURE_1:
1761 				dyn->d_un.d_val |= DTF_1_PARINIT;
1762 				if (dyn->d_un.d_val & DTF_1_CONFEXP)
1763 					crle = 1;
1764 				break;
1765 			case DT_MOVESZ:
1766 				MOVESZ(lmp) = dyn->d_un.d_val;
1767 				FLAGS(lmp) |= FLG_RT_MOVE;
1768 				break;
1769 			case DT_MOVEENT:
1770 				MOVEENT(lmp) = dyn->d_un.d_val;
1771 				break;
1772 			case DT_MOVETAB:
1773 				MOVETAB(lmp) = (void *)(dyn->d_un.d_ptr + base);
1774 				break;
1775 			case DT_REL:
1776 			case DT_RELA:
1777 				/*
1778 				 * At this time, ld.so. can only handle one
1779 				 * type of relocation per object.
1780 				 */
1781 				REL(lmp) = (void *)(dyn->d_un.d_ptr + base);
1782 				break;
1783 			case DT_RELSZ:
1784 			case DT_RELASZ:
1785 				RELSZ(lmp) = dyn->d_un.d_val;
1786 				break;
1787 			case DT_RELENT:
1788 			case DT_RELAENT:
1789 				RELENT(lmp) = dyn->d_un.d_val;
1790 				break;
1791 			case DT_RELCOUNT:
1792 			case DT_RELACOUNT:
1793 				RELACOUNT(lmp) = (uint_t)dyn->d_un.d_val;
1794 				break;
1795 			case DT_HASH:
1796 				HASH(lmp) = (uint_t *)(dyn->d_un.d_ptr + base);
1797 				break;
1798 			case DT_PLTGOT:
1799 				PLTGOT(lmp) =
1800 				    (uint_t *)(dyn->d_un.d_ptr + base);
1801 				break;
1802 			case DT_PLTRELSZ:
1803 				PLTRELSZ(lmp) = dyn->d_un.d_val;
1804 				break;
1805 			case DT_JMPREL:
1806 				JMPREL(lmp) = (void *)(dyn->d_un.d_ptr + base);
1807 				break;
1808 			case DT_INIT:
1809 				if (dyn->d_un.d_ptr != NULL)
1810 					INIT(lmp) =
1811 					    (void (*)())(dyn->d_un.d_ptr +
1812 					    base);
1813 				break;
1814 			case DT_FINI:
1815 				if (dyn->d_un.d_ptr != NULL)
1816 					FINI(lmp) =
1817 					    (void (*)())(dyn->d_un.d_ptr +
1818 					    base);
1819 				break;
1820 			case DT_INIT_ARRAY:
1821 				INITARRAY(lmp) = (Addr *)(dyn->d_un.d_ptr +
1822 				    base);
1823 				break;
1824 			case DT_INIT_ARRAYSZ:
1825 				INITARRAYSZ(lmp) = (uint_t)dyn->d_un.d_val;
1826 				break;
1827 			case DT_FINI_ARRAY:
1828 				FINIARRAY(lmp) = (Addr *)(dyn->d_un.d_ptr +
1829 				    base);
1830 				break;
1831 			case DT_FINI_ARRAYSZ:
1832 				FINIARRAYSZ(lmp) = (uint_t)dyn->d_un.d_val;
1833 				break;
1834 			case DT_PREINIT_ARRAY:
1835 				PREINITARRAY(lmp) = (Addr *)(dyn->d_un.d_ptr +
1836 				    base);
1837 				break;
1838 			case DT_PREINIT_ARRAYSZ:
1839 				PREINITARRAYSZ(lmp) = (uint_t)dyn->d_un.d_val;
1840 				break;
1841 			case DT_RPATH:
1842 			case DT_RUNPATH:
1843 				rpath = dyn->d_un.d_val;
1844 				break;
1845 			case DT_FILTER:
1846 				fltr = dyn->d_un.d_val;
1847 				OBJFLTRNDX(lmp) = dynndx;
1848 				FLAGS1(lmp) |= FL1_RT_OBJSFLTR;
1849 				break;
1850 			case DT_AUXILIARY:
1851 				if (!(rtld_flags & RT_FL_NOAUXFLTR)) {
1852 					fltr = dyn->d_un.d_val;
1853 					OBJFLTRNDX(lmp) = dynndx;
1854 				}
1855 				FLAGS1(lmp) |= FL1_RT_OBJAFLTR;
1856 				break;
1857 			case DT_SUNW_FILTER:
1858 				SYMSFLTRCNT(lmp)++;
1859 				FLAGS1(lmp) |= FL1_RT_SYMSFLTR;
1860 				break;
1861 			case DT_SUNW_AUXILIARY:
1862 				if (!(rtld_flags & RT_FL_NOAUXFLTR)) {
1863 					SYMAFLTRCNT(lmp)++;
1864 				}
1865 				FLAGS1(lmp) |= FL1_RT_SYMAFLTR;
1866 				break;
1867 			case DT_DEPAUDIT:
1868 				if (!(rtld_flags & RT_FL_NOAUDIT))
1869 					audit = dyn->d_un.d_val;
1870 				break;
1871 			case DT_CONFIG:
1872 				cfile = dyn->d_un.d_val;
1873 				break;
1874 			case DT_DEBUG:
1875 				/*
1876 				 * DT_DEBUG entries are only created in
1877 				 * dynamic objects that require an interpretor
1878 				 * (ie. all dynamic executables and some shared
1879 				 * objects), and provide for a hand-shake with
1880 				 * old debuggers.  This entry is initialized to
1881 				 * zero by the link-editor.  If a debugger is
1882 				 * monitoring us, and has updated this entry,
1883 				 * set the debugger monitor flag, and finish
1884 				 * initializing the debugging structure.  See
1885 				 * setup().  Also, switch off any configuration
1886 				 * object use as most debuggers can't handle
1887 				 * fixed dynamic executables as dependencies.
1888 				 */
1889 				if (dyn->d_un.d_ptr)
1890 					rtld_flags |=
1891 					    (RT_FL_DEBUGGER | RT_FL_NOOBJALT);
1892 				dyn->d_un.d_ptr = (Addr)&r_debug;
1893 				break;
1894 			case DT_VERNEED:
1895 				VERNEED(lmp) = (Verneed *)(dyn->d_un.d_ptr +
1896 				    base);
1897 				break;
1898 			case DT_VERNEEDNUM:
1899 				/* LINTED */
1900 				VERNEEDNUM(lmp) = (int)dyn->d_un.d_val;
1901 				break;
1902 			case DT_VERDEF:
1903 				VERDEF(lmp) = (Verdef *)(dyn->d_un.d_ptr +
1904 				    base);
1905 				break;
1906 			case DT_VERDEFNUM:
1907 				/* LINTED */
1908 				VERDEFNUM(lmp) = (int)dyn->d_un.d_val;
1909 				break;
1910 			case DT_VERSYM:
1911 				/*
1912 				 * The Solaris ld does not produce DT_VERSYM,
1913 				 * but the GNU ld does, in order to support
1914 				 * their style of versioning, which differs
1915 				 * from ours in some ways, while using the
1916 				 * same data structures. The presence of
1917 				 * DT_VERSYM therefore means that GNU
1918 				 * versioning rules apply to the given file.
1919 				 * If DT_VERSYM is not present, then Solaris
1920 				 * versioning rules apply.
1921 				 */
1922 				VERSYM(lmp) = (Versym *)(dyn->d_un.d_ptr +
1923 				    base);
1924 				break;
1925 			case DT_BIND_NOW:
1926 				if ((dyn->d_un.d_val & DF_BIND_NOW) &&
1927 				    ((rtld_flags2 & RT_FL2_BINDLAZY) == 0)) {
1928 					MODE(lmp) |= RTLD_NOW;
1929 					MODE(lmp) &= ~RTLD_LAZY;
1930 				}
1931 				break;
1932 			case DT_FLAGS:
1933 				FLAGS1(lmp) |= FL1_RT_DTFLAGS;
1934 				if (dyn->d_un.d_val & DF_SYMBOLIC)
1935 					FLAGS1(lmp) |= FL1_RT_SYMBOLIC;
1936 				if ((dyn->d_un.d_val & DF_BIND_NOW) &&
1937 				    ((rtld_flags2 & RT_FL2_BINDLAZY) == 0)) {
1938 					MODE(lmp) |= RTLD_NOW;
1939 					MODE(lmp) &= ~RTLD_LAZY;
1940 				}
1941 				/*
1942 				 * Capture any static TLS use, and enforce that
1943 				 * this object be non-deletable.
1944 				 */
1945 				if (dyn->d_un.d_val & DF_STATIC_TLS) {
1946 					FLAGS1(lmp) |= FL1_RT_TLSSTAT;
1947 					MODE(lmp) |= RTLD_NODELETE;
1948 				}
1949 				break;
1950 			case DT_FLAGS_1:
1951 				if (dyn->d_un.d_val & DF_1_DISPRELPND)
1952 					FLAGS1(lmp) |= FL1_RT_DISPREL;
1953 				if (dyn->d_un.d_val & DF_1_GROUP)
1954 					FLAGS(lmp) |=
1955 					    (FLG_RT_SETGROUP | FLG_RT_PUBHDL);
1956 				if ((dyn->d_un.d_val & DF_1_NOW) &&
1957 				    ((rtld_flags2 & RT_FL2_BINDLAZY) == 0)) {
1958 					MODE(lmp) |= RTLD_NOW;
1959 					MODE(lmp) &= ~RTLD_LAZY;
1960 				}
1961 				if (dyn->d_un.d_val & DF_1_NODELETE)
1962 					MODE(lmp) |= RTLD_NODELETE;
1963 				if (dyn->d_un.d_val & DF_1_INITFIRST)
1964 					FLAGS(lmp) |= FLG_RT_INITFRST;
1965 				if (dyn->d_un.d_val & DF_1_NOOPEN)
1966 					FLAGS(lmp) |= FLG_RT_NOOPEN;
1967 				if (dyn->d_un.d_val & DF_1_LOADFLTR)
1968 					FLAGS(lmp) |= FLG_RT_LOADFLTR;
1969 				if (dyn->d_un.d_val & DF_1_NODUMP)
1970 					FLAGS(lmp) |= FLG_RT_NODUMP;
1971 				if (dyn->d_un.d_val & DF_1_CONFALT)
1972 					crle = 1;
1973 				if (dyn->d_un.d_val & DF_1_DIRECT)
1974 					FLAGS1(lmp) |= FL1_RT_DIRECT;
1975 				if (dyn->d_un.d_val & DF_1_NODEFLIB)
1976 					FLAGS1(lmp) |= FL1_RT_NODEFLIB;
1977 				if (dyn->d_un.d_val & DF_1_ENDFILTEE)
1978 					FLAGS1(lmp) |= FL1_RT_ENDFILTE;
1979 				if (dyn->d_un.d_val & DF_1_TRANS)
1980 					FLAGS(lmp) |= FLG_RT_TRANS;
1981 
1982 				/*
1983 				 * Global auditing is only meaningful when
1984 				 * specified by the initiating object of the
1985 				 * process - typically the dynamic executable.
1986 				 * If this is the initiaiting object, its link-
1987 				 * map will not yet have been added to the
1988 				 * link-map list, and consequently the link-map
1989 				 * list is empty.  (see setup()).
1990 				 */
1991 				if (dyn->d_un.d_val & DF_1_GLOBAUDIT) {
1992 					if (lml_main.lm_head == NULL)
1993 						FLAGS1(lmp) |= FL1_RT_GLOBAUD;
1994 					else
1995 						DBG_CALL(Dbg_audit_ignore(lmp));
1996 				}
1997 
1998 				/*
1999 				 * If this object identifies itself as an
2000 				 * interposer, but relocation processing has
2001 				 * already started, then demote it.  It's too
2002 				 * late to guarantee complete interposition.
2003 				 */
2004 				/* BEGIN CSTYLED */
2005 				if (dyn->d_un.d_val &
2006 				    (DF_1_INTERPOSE | DF_1_SYMINTPOSE)) {
2007 				    if (lml->lm_flags & LML_FLG_STARTREL) {
2008 					DBG_CALL(Dbg_util_intoolate(lmp));
2009 					if (lml->lm_flags & LML_FLG_TRC_ENABLE)
2010 					    (void) printf(
2011 						MSG_INTL(MSG_LDD_REL_ERR2),
2012 						NAME(lmp));
2013 				    } else if (dyn->d_un.d_val & DF_1_INTERPOSE)
2014 					FLAGS(lmp) |= FLG_RT_OBJINTPO;
2015 				    else
2016 					FLAGS(lmp) |= FLG_RT_SYMINTPO;
2017 				}
2018 				/* END CSTYLED */
2019 				break;
2020 			case DT_SYMINFO:
2021 				SYMINFO(lmp) = (Syminfo *)(dyn->d_un.d_ptr +
2022 				    base);
2023 				break;
2024 			case DT_SYMINENT:
2025 				SYMINENT(lmp) = dyn->d_un.d_val;
2026 				break;
2027 			case DT_PLTPAD:
2028 				PLTPAD(lmp) = (void *)(dyn->d_un.d_ptr + base);
2029 				break;
2030 			case DT_PLTPADSZ:
2031 				pltpadsz = dyn->d_un.d_val;
2032 				break;
2033 			case DT_SUNW_RTLDINF:
2034 				/*
2035 				 * Maintain a list of RTLDINFO structures.
2036 				 * Typically, libc is the only supplier, and
2037 				 * only one structure is provided.  However,
2038 				 * multiple suppliers and multiple structures
2039 				 * are supported.  For example, one structure
2040 				 * may provide thread_init, and another
2041 				 * structure may provide atexit reservations.
2042 				 */
2043 				if ((rti = alist_append(&lml->lm_rti, NULL,
2044 				    sizeof (Rti_desc),
2045 				    AL_CNT_RTLDINFO)) == NULL) {
2046 					remove_so(0, lmp);
2047 					return (NULL);
2048 				}
2049 				rti->rti_lmp = lmp;
2050 				rti->rti_info = (void *)(dyn->d_un.d_ptr +
2051 				    base);
2052 				break;
2053 			case DT_SUNW_SORTENT:
2054 				SUNWSORTENT(lmp) = dyn->d_un.d_val;
2055 				break;
2056 			case DT_SUNW_SYMSORT:
2057 				SUNWSYMSORT(lmp) =
2058 				    (void *)(dyn->d_un.d_ptr + base);
2059 				break;
2060 			case DT_SUNW_SYMSORTSZ:
2061 				SUNWSYMSORTSZ(lmp) = dyn->d_un.d_val;
2062 				break;
2063 			case DT_DEPRECATED_SPARC_REGISTER:
2064 			case M_DT_REGISTER:
2065 				FLAGS(lmp) |= FLG_RT_REGSYMS;
2066 				break;
2067 			}
2068 		}
2069 
2070 		if (PLTPAD(lmp)) {
2071 			if (pltpadsz == (Xword)0)
2072 				PLTPAD(lmp) = NULL;
2073 			else
2074 				PLTPADEND(lmp) = (void *)((Addr)PLTPAD(lmp) +
2075 				    pltpadsz);
2076 		}
2077 	}
2078 
2079 	/*
2080 	 * A dynsym contains only global functions. We want to have
2081 	 * a version of it that also includes local functions, so that
2082 	 * dladdr() will be able to report names for local functions
2083 	 * when used to generate a stack trace for a stripped file.
2084 	 * This version of the dynsym is provided via DT_SUNW_SYMTAB.
2085 	 *
2086 	 * In producing DT_SUNW_SYMTAB, ld uses a non-obvious trick
2087 	 * in order to avoid having to have two copies of the global
2088 	 * symbols held in DT_SYMTAB: The local symbols are placed in
2089 	 * a separate section than the globals in the dynsym, but the
2090 	 * linker conspires to put the data for these two sections adjacent
2091 	 * to each other. DT_SUNW_SYMTAB points at the top of the local
2092 	 * symbols, and DT_SUNW_SYMSZ is the combined length of both tables.
2093 	 *
2094 	 * If the two sections are not adjacent, then something went wrong
2095 	 * at link time. We use ASSERT to kill the process if this is
2096 	 * a debug build. In a production build, we will silently ignore
2097 	 * the presence of the .ldynsym and proceed. We can detect this
2098 	 * situation by checking to see that DT_SYMTAB lies in
2099 	 * the range given by DT_SUNW_SYMTAB/DT_SUNW_SYMSZ.
2100 	 */
2101 	if ((SUNWSYMTAB(lmp) != NULL) &&
2102 	    (((char *)SYMTAB(lmp) <= (char *)SUNWSYMTAB(lmp)) ||
2103 	    (((char *)SYMTAB(lmp) >=
2104 	    (SUNWSYMSZ(lmp) + (char *)SUNWSYMTAB(lmp)))))) {
2105 		ASSERT(0);
2106 		SUNWSYMTAB(lmp) = NULL;
2107 		SUNWSYMSZ(lmp) = 0;
2108 	}
2109 
2110 	/*
2111 	 * If configuration file use hasn't been disabled, and a configuration
2112 	 * file hasn't already been set via an environment variable, see if any
2113 	 * application specific configuration file is specified.  An LD_CONFIG
2114 	 * setting is used first, but if this image was generated via crle(1)
2115 	 * then a default configuration file is a fall-back.
2116 	 */
2117 	if ((!(rtld_flags & RT_FL_NOCFG)) && (config->c_name == NULL)) {
2118 		if (cfile)
2119 			config->c_name = (const char *)(cfile +
2120 			    (char *)STRTAB(lmp));
2121 		else if (crle)
2122 			rtld_flags |= RT_FL_CONFAPP;
2123 	}
2124 
2125 	if (rpath)
2126 		RPATH(lmp) = (char *)(rpath + (char *)STRTAB(lmp));
2127 	if (fltr)
2128 		REFNAME(lmp) = (char *)(fltr + (char *)STRTAB(lmp));
2129 
2130 	/*
2131 	 * For Intel ABI compatibility.  It's possible that a JMPREL can be
2132 	 * specified without any other relocations (e.g. a dynamic executable
2133 	 * normally only contains .plt relocations).  If this is the case then
2134 	 * no REL, RELSZ or RELENT will have been created.  For us to be able
2135 	 * to traverse the .plt relocations under LD_BIND_NOW we need to know
2136 	 * the RELENT for these relocations.  Refer to elf_reloc() for more
2137 	 * details.
2138 	 */
2139 	if (!RELENT(lmp) && JMPREL(lmp))
2140 		RELENT(lmp) = sizeof (M_RELOC);
2141 
2142 	/*
2143 	 * Establish any per-object auditing.  If we're establishing `main's
2144 	 * link-map its too early to go searching for audit objects so just
2145 	 * hold the object name for later (see setup()).
2146 	 */
2147 	if (audit) {
2148 		char	*cp = audit + (char *)STRTAB(lmp);
2149 
2150 		if (*cp) {
2151 			if (((AUDITORS(lmp) =
2152 			    calloc(1, sizeof (Audit_desc))) == NULL) ||
2153 			    ((AUDITORS(lmp)->ad_name = strdup(cp)) == NULL)) {
2154 				remove_so(0, lmp);
2155 				return (NULL);
2156 			}
2157 			if (lml_main.lm_head) {
2158 				if (audit_setup(lmp, AUDITORS(lmp), 0,
2159 				    in_nfavl) == 0) {
2160 					remove_so(0, lmp);
2161 					return (NULL);
2162 				}
2163 				AFLAGS(lmp) |= AUDITORS(lmp)->ad_flags;
2164 				lml->lm_flags |= LML_FLG_LOCAUDIT;
2165 			}
2166 		}
2167 	}
2168 
2169 	if (tphdr && (tls_assign(lml, lmp, tphdr) == 0)) {
2170 		remove_so(0, lmp);
2171 		return (NULL);
2172 	}
2173 
2174 	if (cap)
2175 		cap_assign(cap, lmp);
2176 
2177 	/*
2178 	 * Add the mapped object to the end of the link map list.
2179 	 */
2180 	lm_append(lml, lmco, lmp);
2181 
2182 	/*
2183 	 * Start the system loading in the ELF information we'll be processing.
2184 	 */
2185 	if (REL(lmp)) {
2186 		(void) madvise((void *)ADDR(lmp), (uintptr_t)REL(lmp) +
2187 		    (uintptr_t)RELSZ(lmp) - (uintptr_t)ADDR(lmp),
2188 		    MADV_WILLNEED);
2189 	}
2190 	return (lmp);
2191 }
2192 
2193 /*
2194  * Assign hardware/software capabilities.
2195  */
2196 void
2197 cap_assign(Cap *cap, Rt_map *lmp)
2198 {
2199 	while (cap->c_tag != CA_SUNW_NULL) {
2200 		switch (cap->c_tag) {
2201 		case CA_SUNW_HW_1:
2202 			HWCAP(lmp) = cap->c_un.c_val;
2203 			break;
2204 		case CA_SUNW_SF_1:
2205 			SFCAP(lmp) = cap->c_un.c_val;
2206 		}
2207 		cap++;
2208 	}
2209 }
2210 
2211 /*
2212  * Build full pathname of shared object from given directory name and filename.
2213  */
2214 static char *
2215 elf_get_so(const char *dir, const char *file, size_t dlen, size_t flen)
2216 {
2217 	static char	pname[PATH_MAX];
2218 
2219 	(void) strncpy(pname, dir, dlen);
2220 	pname[dlen++] = '/';
2221 	(void) strncpy(&pname[dlen], file, flen + 1);
2222 	return (pname);
2223 }
2224 
2225 /*
2226  * The copy relocation is recorded in a copy structure which will be applied
2227  * after all other relocations are carried out.  This provides for copying data
2228  * that must be relocated itself (ie. pointers in shared objects).  This
2229  * structure also provides a means of binding RTLD_GROUP dependencies to any
2230  * copy relocations that have been taken from any group members.
2231  *
2232  * If the size of the .bss area available for the copy information is not the
2233  * same as the source of the data inform the user if we're under ldd(1) control
2234  * (this checking was only established in 5.3, so by only issuing an error via
2235  * ldd(1) we maintain the standard set by previous releases).
2236  */
2237 int
2238 elf_copy_reloc(char *name, Sym *rsym, Rt_map *rlmp, void *radd, Sym *dsym,
2239     Rt_map *dlmp, const void *dadd)
2240 {
2241 	Rel_copy	rc;
2242 	Lm_list		*lml = LIST(rlmp);
2243 
2244 	rc.r_name = name;
2245 	rc.r_rsym = rsym;		/* the new reference symbol and its */
2246 	rc.r_rlmp = rlmp;		/*	associated link-map */
2247 	rc.r_dlmp = dlmp;		/* the defining link-map */
2248 	rc.r_dsym = dsym;		/* the original definition */
2249 	rc.r_radd = radd;
2250 	rc.r_dadd = dadd;
2251 
2252 	if (rsym->st_size > dsym->st_size)
2253 		rc.r_size = (size_t)dsym->st_size;
2254 	else
2255 		rc.r_size = (size_t)rsym->st_size;
2256 
2257 	if (alist_append(&COPY_R(dlmp), &rc, sizeof (Rel_copy),
2258 	    AL_CNT_COPYREL) == NULL) {
2259 		if (!(lml->lm_flags & LML_FLG_TRC_WARN))
2260 			return (0);
2261 		else
2262 			return (1);
2263 	}
2264 	if (!(FLAGS1(dlmp) & FL1_RT_COPYTOOK)) {
2265 		if (aplist_append(&COPY_S(rlmp), dlmp,
2266 		    AL_CNT_COPYREL) == NULL) {
2267 			if (!(lml->lm_flags & LML_FLG_TRC_WARN))
2268 				return (0);
2269 			else
2270 				return (1);
2271 		}
2272 		FLAGS1(dlmp) |= FL1_RT_COPYTOOK;
2273 	}
2274 
2275 	/*
2276 	 * If we are tracing (ldd), warn the user if
2277 	 *	1) the size from the reference symbol differs from the
2278 	 *	   copy definition. We can only copy as much data as the
2279 	 *	   reference (dynamic executables) entry allows.
2280 	 *	2) the copy definition has STV_PROTECTED visibility.
2281 	 */
2282 	if (lml->lm_flags & LML_FLG_TRC_WARN) {
2283 		if (rsym->st_size != dsym->st_size) {
2284 			(void) printf(MSG_INTL(MSG_LDD_CPY_SIZDIF),
2285 			    _conv_reloc_type(M_R_COPY), demangle(name),
2286 			    NAME(rlmp), EC_XWORD(rsym->st_size),
2287 			    NAME(dlmp), EC_XWORD(dsym->st_size));
2288 			if (rsym->st_size > dsym->st_size)
2289 				(void) printf(MSG_INTL(MSG_LDD_CPY_INSDATA),
2290 				    NAME(dlmp));
2291 			else
2292 				(void) printf(MSG_INTL(MSG_LDD_CPY_DATRUNC),
2293 				    NAME(rlmp));
2294 		}
2295 
2296 		if (ELF_ST_VISIBILITY(dsym->st_other) == STV_PROTECTED) {
2297 			(void) printf(MSG_INTL(MSG_LDD_CPY_PROT),
2298 			    _conv_reloc_type(M_R_COPY), demangle(name),
2299 			    NAME(dlmp));
2300 		}
2301 	}
2302 
2303 	DBG_CALL(Dbg_reloc_apply_val(lml, ELF_DBG_RTLD, (Xword)radd,
2304 	    (Xword)rc.r_size));
2305 	return (1);
2306 }
2307 
2308 /*
2309  * Determine the symbol location of an address within a link-map.  Look for
2310  * the nearest symbol (whose value is less than or equal to the required
2311  * address).  This is the object specific part of dladdr().
2312  */
2313 static void
2314 elf_dladdr(ulong_t addr, Rt_map *lmp, Dl_info *dlip, void **info, int flags)
2315 {
2316 	ulong_t		ndx, cnt, base, _value;
2317 	Sym		*sym, *_sym = NULL;
2318 	const char	*str;
2319 	int		_flags;
2320 	uint_t		*dynaddr_ndx;
2321 	uint_t		dynaddr_n = 0;
2322 	ulong_t		value;
2323 
2324 	/*
2325 	 * If SUNWSYMTAB() is non-NULL, then it sees a special version of
2326 	 * the dynsym that starts with any local function symbols that exist in
2327 	 * the library and then moves to the data held in SYMTAB(). In this
2328 	 * case, SUNWSYMSZ tells us how long the symbol table is. The
2329 	 * availability of local function symbols will enhance the results
2330 	 * we can provide.
2331 	 *
2332 	 * If SUNWSYMTAB() is non-NULL, then there might also be a
2333 	 * SUNWSYMSORT() vector associated with it. SUNWSYMSORT() contains
2334 	 * an array of indices into SUNWSYMTAB, sorted by increasing
2335 	 * address. We can use this to do an O(log N) search instead of a
2336 	 * brute force search.
2337 	 *
2338 	 * If SUNWSYMTAB() is NULL, then SYMTAB() references a dynsym that
2339 	 * contains only global symbols. In that case, the length of
2340 	 * the symbol table comes from the nchain field of the related
2341 	 * symbol lookup hash table.
2342 	 */
2343 	str = STRTAB(lmp);
2344 	if (SUNWSYMSZ(lmp) == NULL) {
2345 		sym = SYMTAB(lmp);
2346 		/*
2347 		 * If we don't have a .hash table there are no symbols
2348 		 * to look at.
2349 		 */
2350 		if (HASH(lmp) == NULL)
2351 			return;
2352 		cnt = HASH(lmp)[1];
2353 	} else {
2354 		sym = SUNWSYMTAB(lmp);
2355 		cnt = SUNWSYMSZ(lmp) / SYMENT(lmp);
2356 		dynaddr_ndx = SUNWSYMSORT(lmp);
2357 		if (dynaddr_ndx != NULL)
2358 			dynaddr_n = SUNWSYMSORTSZ(lmp) / SUNWSORTENT(lmp);
2359 	}
2360 
2361 	if (FLAGS(lmp) & FLG_RT_FIXED)
2362 		base = 0;
2363 	else
2364 		base = ADDR(lmp);
2365 
2366 	if (dynaddr_n > 0) {		/* Binary search */
2367 		long	low = 0, low_bnd;
2368 		long	high = dynaddr_n - 1, high_bnd;
2369 		long	mid;
2370 		Sym	*mid_sym;
2371 
2372 		/*
2373 		 * Note that SUNWSYMSORT only contains symbols types that
2374 		 * supply memory addresses, so there's no need to check and
2375 		 * filter out any other types.
2376 		 */
2377 		low_bnd = low;
2378 		high_bnd = high;
2379 		while (low <= high) {
2380 			mid = (low + high) / 2;
2381 			mid_sym = &sym[dynaddr_ndx[mid]];
2382 			value = mid_sym->st_value + base;
2383 			if (addr < value) {
2384 				if ((sym[dynaddr_ndx[high]].st_value + base) >=
2385 				    addr)
2386 					high_bnd = high;
2387 				high = mid - 1;
2388 			} else if (addr > value) {
2389 				if ((sym[dynaddr_ndx[low]].st_value + base) <=
2390 				    addr)
2391 					low_bnd = low;
2392 				low = mid + 1;
2393 			} else {
2394 				_sym = mid_sym;
2395 				_value = value;
2396 				break;
2397 			}
2398 		}
2399 		/*
2400 		 * If the above didn't find it exactly, then we must
2401 		 * return the closest symbol with a value that doesn't
2402 		 * exceed the one we are looking for. If that symbol exists,
2403 		 * it will lie in the range bounded by low_bnd and
2404 		 * high_bnd. This is a linear search, but a short one.
2405 		 */
2406 		if (_sym == NULL) {
2407 			for (mid = low_bnd; mid <= high_bnd; mid++) {
2408 				mid_sym = &sym[dynaddr_ndx[mid]];
2409 				value = mid_sym->st_value + base;
2410 				if (addr >= value) {
2411 					_sym = mid_sym;
2412 					_value = value;
2413 				} else {
2414 					break;
2415 				}
2416 			}
2417 		}
2418 	} else {			/* Linear search */
2419 		for (_value = 0, sym++, ndx = 1; ndx < cnt; ndx++, sym++) {
2420 			/*
2421 			 * Skip expected symbol types that are not functions
2422 			 * or data:
2423 			 *	- A symbol table starts with an undefined symbol
2424 			 *		in slot 0. If we are using SUNWSYMTAB(),
2425 			 *		there will be a second undefined symbol
2426 			 *		right before the globals.
2427 			 *	- The local part of SUNWSYMTAB() contains a
2428 			 *		series of function symbols. Each section
2429 			 *		starts with an initial STT_FILE symbol.
2430 			 */
2431 			if ((sym->st_shndx == SHN_UNDEF) ||
2432 			    (ELF_ST_TYPE(sym->st_info) == STT_FILE))
2433 				continue;
2434 
2435 			value = sym->st_value + base;
2436 			if (value > addr)
2437 				continue;
2438 			if (value < _value)
2439 				continue;
2440 
2441 			_sym = sym;
2442 			_value = value;
2443 
2444 			/*
2445 			 * Note, because we accept local and global symbols
2446 			 * we could find a section symbol that matches the
2447 			 * associated address, which means that the symbol
2448 			 * name will be null.  In this case continue the
2449 			 * search in case we can find a global symbol of
2450 			 * the same value.
2451 			 */
2452 			if ((value == addr) &&
2453 			    (ELF_ST_TYPE(sym->st_info) != STT_SECTION))
2454 				break;
2455 		}
2456 	}
2457 
2458 	_flags = flags & RTLD_DL_MASK;
2459 	if (_sym) {
2460 		if (_flags == RTLD_DL_SYMENT)
2461 			*info = (void *)_sym;
2462 		else if (_flags == RTLD_DL_LINKMAP)
2463 			*info = (void *)lmp;
2464 
2465 		dlip->dli_sname = str + _sym->st_name;
2466 		dlip->dli_saddr = (void *)_value;
2467 	} else {
2468 		/*
2469 		 * addr lies between the beginning of the mapped segment and
2470 		 * the first global symbol. We have no symbol to return
2471 		 * and the caller requires one. We use _START_, the base
2472 		 * address of the mapping.
2473 		 */
2474 
2475 		if (_flags == RTLD_DL_SYMENT) {
2476 			/*
2477 			 * An actual symbol struct is needed, so we
2478 			 * construct one for _START_. To do this in a
2479 			 * fully accurate way requires a different symbol
2480 			 * for each mapped segment. This requires the
2481 			 * use of dynamic memory and a mutex. That's too much
2482 			 * plumbing for a fringe case of limited importance.
2483 			 *
2484 			 * Fortunately, we can simplify:
2485 			 *    - Only the st_size and st_info fields are useful
2486 			 *	outside of the linker internals. The others
2487 			 *	reference things that outside code cannot see,
2488 			 *	and can be set to 0.
2489 			 *    - It's just a label and there is no size
2490 			 *	to report. So, the size should be 0.
2491 			 * This means that only st_info needs a non-zero
2492 			 * (constant) value. A static struct will suffice.
2493 			 * It must be const (readonly) so the caller can't
2494 			 * change its meaning for subsequent callers.
2495 			 */
2496 			static const Sym fsym = { 0, 0, 0,
2497 			    ELF_ST_INFO(STB_LOCAL, STT_OBJECT) };
2498 			*info = (void *) &fsym;
2499 		}
2500 
2501 		dlip->dli_sname = MSG_ORIG(MSG_SYM_START);
2502 		dlip->dli_saddr = (void *) ADDR(lmp);
2503 	}
2504 }
2505 
2506 /*
2507  * This routine is called as a last fall-back to search for a symbol from a
2508  * standard relocation or dlsym().  To maintain lazy loadings goal of reducing
2509  * the number of objects mapped, any symbol search is first carried out using
2510  * the objects that already exist in the process (either on a link-map list or
2511  * handle).  If a symbol can't be found, and lazy dependencies are still
2512  * pending, this routine loads the dependencies in an attempt to locate the
2513  * symbol.
2514  */
2515 Sym *
2516 elf_lazy_find_sym(Slookup *slp, Rt_map **_lmp, uint_t *binfo, int *in_nfavl)
2517 {
2518 	Sym		*sym = NULL;
2519 	static APlist	*alist = NULL;
2520 	Aliste		idx1;
2521 	Rt_map		*lmp1, *lmp = slp->sl_imap, *clmp = slp->sl_cmap;
2522 	const char	*name = slp->sl_name;
2523 	Slookup		sl1 = *slp;
2524 	Lm_list		*lml;
2525 	Lm_cntl		*lmc;
2526 
2527 	/*
2528 	 * It's quite possible we've been here before to process objects,
2529 	 * therefore reinitialize our dynamic list.
2530 	 */
2531 	if (alist)
2532 		aplist_reset(alist);
2533 
2534 	/*
2535 	 * Discard any relocation index from further symbol searches.  This
2536 	 * index has already been used to trigger any necessary lazy-loads,
2537 	 * and it might be because one of these lazy loads has failed that
2538 	 * we're performing this fallback.  By removing the relocation index
2539 	 * we don't try and perform the same failed lazy loading activity again.
2540 	 */
2541 	sl1.sl_rsymndx = 0;
2542 
2543 	/*
2544 	 * Determine the callers link-map list so that we can monitor whether
2545 	 * new objects have been added.
2546 	 */
2547 	lml = LIST(clmp);
2548 	lmc = (Lm_cntl *)alist_item_by_offset(lml->lm_lists, CNTL(clmp));
2549 
2550 	/*
2551 	 * Generate a local list of new objects to process.  This list can grow
2552 	 * as each object supplies its own lazy dependencies.
2553 	 */
2554 	if (aplist_append(&alist, lmp, AL_CNT_LAZYFIND) == NULL)
2555 		return (NULL);
2556 
2557 	for (APLIST_TRAVERSE(alist, idx1, lmp1)) {
2558 		uint_t	cnt = 0;
2559 		Dyninfo	*dip, *pdip;
2560 
2561 		/*
2562 		 * Loop through the lazy DT_NEEDED entries examining each object
2563 		 * for the required symbol.  If the symbol is not found, the
2564 		 * object is in turn added to the local alist, so that the
2565 		 * objects lazy DT_NEEDED entries can be examined.
2566 		 */
2567 		lmp = lmp1;
2568 		for (dip = DYNINFO(lmp), pdip = NULL; cnt < DYNINFOCNT(lmp);
2569 		    cnt++, pdip = dip++) {
2570 			Grp_hdl		*ghp;
2571 			Grp_desc	*gdp;
2572 			Rt_map		*nlmp, *llmp;
2573 			Slookup		sl2;
2574 			Aliste		idx2;
2575 
2576 			if (((dip->di_flags & FLG_DI_LAZY) == 0) ||
2577 			    dip->di_info)
2578 				continue;
2579 
2580 			/*
2581 			 * If this object has already failed to lazy load, and
2582 			 * we're still processing the same runtime linker
2583 			 * operation that produced the failure, don't bother
2584 			 * to try and load the object again.
2585 			 */
2586 			if ((dip->di_flags & FLG_DI_LAZYFAIL) && pdip &&
2587 			    (pdip->di_flags & FLG_DI_POSFLAG1)) {
2588 				if (pdip->di_info == (void *)ld_entry_cnt)
2589 					continue;
2590 
2591 				dip->di_flags &= ~FLG_DI_LAZYFAIL;
2592 				pdip->di_info = NULL;
2593 			}
2594 
2595 			/*
2596 			 * Determine the last link-map presently on the callers
2597 			 * link-map control list.
2598 			 */
2599 			llmp = lmc->lc_tail;
2600 
2601 			/*
2602 			 * Try loading this lazy dependency.  If the object
2603 			 * can't be loaded, consider this non-fatal and continue
2604 			 * the search.  Lazy loaded dependencies need not exist
2605 			 * and their loading should only turn out to be fatal
2606 			 * if they are required to satisfy a relocation.
2607 			 *
2608 			 * A successful lazy load can mean one of two things:
2609 			 *
2610 			 *  -	new objects have been loaded, in which case the
2611 			 * 	objects will have been analyzed, relocated, and
2612 			 * 	finally moved to the callers control list.
2613 			 *  -	the objects are already loaded, and this lazy
2614 			 *	load has simply associated the referenced object
2615 			 *	with it's lazy dependencies.
2616 			 *
2617 			 * If new objects are loaded, look in these objects
2618 			 * first.  Note, a new object can be the object being
2619 			 * referenced by this lazy load, however we can also
2620 			 * descend into multiple lazy loads as we relocate this
2621 			 * reference.
2622 			 *
2623 			 * If the symbol hasn't been found, use the referenced
2624 			 * objects handle, as it might have dependencies on
2625 			 * objects that are already loaded.  Note that existing
2626 			 * objects might have already been searched and skipped
2627 			 * as non-available to this caller.   However, a lazy
2628 			 * load might have caused the promotion of modes, or
2629 			 * added this object to the family of the caller.  In
2630 			 * either case, the handle associated with the object
2631 			 * is then used to carry out the symbol search.
2632 			 */
2633 			if ((nlmp = elf_lazy_load(lmp, &sl1, cnt, name,
2634 			    FLG_RT_PRIHDL, &ghp, in_nfavl)) == NULL)
2635 				continue;
2636 
2637 			if (NEXT_RT_MAP(llmp)) {
2638 				/*
2639 				 * Look in any new objects.
2640 				 */
2641 				sl1.sl_imap = NEXT_RT_MAP(llmp);
2642 				sl1.sl_flags &= ~LKUP_STDRELOC;
2643 
2644 				if ((sym = lookup_sym(&sl1, _lmp, binfo,
2645 				    in_nfavl)) != NULL)
2646 					return (sym);
2647 			}
2648 
2649 			/*
2650 			 * Use the objects handle to inspect the family of
2651 			 * objects associated with the handle.  Note, there's
2652 			 * a possibility of overlap with the above search,
2653 			 * should a lazy load bring in new objects and
2654 			 * reference existing objects.
2655 			 */
2656 			sl2 = sl1;
2657 			for (ALIST_TRAVERSE(ghp->gh_depends, idx2, gdp)) {
2658 				if ((gdp->gd_depend != NEXT_RT_MAP(llmp)) &&
2659 				    (gdp->gd_flags & GPD_DLSYM)) {
2660 
2661 					sl2.sl_imap = gdp->gd_depend;
2662 					sl2.sl_flags |= LKUP_FIRST;
2663 
2664 					if ((sym = lookup_sym(&sl2, _lmp, binfo,
2665 					    in_nfavl)) != NULL)
2666 						return (sym);
2667 				}
2668 			}
2669 
2670 			/*
2671 			 * Some dlsym() operations are already traversing a
2672 			 * link-map (dlopen(0)), and thus there's no need to
2673 			 * save them on the dynamic dependency list.
2674 			 */
2675 			if (slp->sl_flags & LKUP_NODESCENT)
2676 				continue;
2677 
2678 			if (aplist_test(&alist, nlmp, AL_CNT_LAZYFIND) == NULL)
2679 				return (NULL);
2680 		}
2681 	}
2682 
2683 	return (NULL);
2684 }
2685 
2686 /*
2687  * Warning message for bad r_offset.
2688  */
2689 void
2690 elf_reloc_bad(Rt_map *lmp, void *rel, uchar_t rtype, ulong_t roffset,
2691     ulong_t rsymndx)
2692 {
2693 	const char	*name = NULL;
2694 	Lm_list		*lml = LIST(lmp);
2695 	int		trace;
2696 
2697 	if ((lml->lm_flags & LML_FLG_TRC_ENABLE) &&
2698 	    (((rtld_flags & RT_FL_SILENCERR) == 0) ||
2699 	    (lml->lm_flags & LML_FLG_TRC_VERBOSE)))
2700 		trace = 1;
2701 	else
2702 		trace = 0;
2703 
2704 	if ((trace == 0) && (DBG_ENABLED == 0))
2705 		return;
2706 
2707 	if (rsymndx) {
2708 		Sym	*symref = (Sym *)((ulong_t)SYMTAB(lmp) +
2709 		    (rsymndx * SYMENT(lmp)));
2710 
2711 		if (ELF_ST_BIND(symref->st_info) != STB_LOCAL)
2712 			name = (char *)(STRTAB(lmp) + symref->st_name);
2713 	}
2714 
2715 	if (name == NULL)
2716 		name = MSG_INTL(MSG_STR_UNKNOWN);
2717 
2718 	if (trace) {
2719 		const char *rstr;
2720 
2721 		rstr = _conv_reloc_type((uint_t)rtype);
2722 		(void) printf(MSG_INTL(MSG_LDD_REL_ERR1), rstr, name,
2723 		    EC_ADDR(roffset));
2724 		return;
2725 	}
2726 
2727 	Dbg_reloc_error(lml, ELF_DBG_RTLD, M_MACH, M_REL_SHT_TYPE, rel, name);
2728 }
2729 
2730 /*
2731  * Resolve a static TLS relocation.
2732  */
2733 long
2734 elf_static_tls(Rt_map *lmp, Sym *sym, void *rel, uchar_t rtype, char *name,
2735     ulong_t roffset, long value)
2736 {
2737 	Lm_list	*lml = LIST(lmp);
2738 
2739 	/*
2740 	 * Relocations against a static TLS block have limited support once
2741 	 * process initialization has completed.  Any error condition should be
2742 	 * discovered by testing for DF_STATIC_TLS as part of loading an object,
2743 	 * however individual relocations are tested in case the dynamic flag
2744 	 * had not been set when this object was built.
2745 	 */
2746 	if (PTTLS(lmp) == NULL) {
2747 		DBG_CALL(Dbg_reloc_in(lml, ELF_DBG_RTLD, M_MACH,
2748 		    M_REL_SHT_TYPE, rel, NULL, 0, name));
2749 		eprintf(lml, ERR_FATAL, MSG_INTL(MSG_REL_BADTLS),
2750 		    _conv_reloc_type((uint_t)rtype), NAME(lmp),
2751 		    name ? demangle(name) : MSG_INTL(MSG_STR_UNKNOWN));
2752 		return (0);
2753 	}
2754 
2755 	/*
2756 	 * If no static TLS has been set aside for this object, determine if
2757 	 * any can be obtained.  Enforce that any object using static TLS is
2758 	 * non-deletable.
2759 	 */
2760 	if (TLSSTATOFF(lmp) == 0) {
2761 		FLAGS1(lmp) |= FL1_RT_TLSSTAT;
2762 		MODE(lmp) |= RTLD_NODELETE;
2763 
2764 		if (tls_assign(lml, lmp, PTTLS(lmp)) == 0) {
2765 			DBG_CALL(Dbg_reloc_in(lml, ELF_DBG_RTLD, M_MACH,
2766 			    M_REL_SHT_TYPE, rel, NULL, 0, name));
2767 			eprintf(lml, ERR_FATAL, MSG_INTL(MSG_REL_BADTLS),
2768 			    _conv_reloc_type((uint_t)rtype), NAME(lmp),
2769 			    name ? demangle(name) : MSG_INTL(MSG_STR_UNKNOWN));
2770 			return (0);
2771 		}
2772 	}
2773 
2774 	/*
2775 	 * Typically, a static TLS offset is maintained as a symbols value.
2776 	 * For local symbols that are not apart of the dynamic symbol table,
2777 	 * the TLS relocation points to a section symbol, and the static TLS
2778 	 * offset was deposited in the associated GOT table.  Make sure the GOT
2779 	 * is cleared, so that the value isn't reused in do_reloc().
2780 	 */
2781 	if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) {
2782 		if ((ELF_ST_TYPE(sym->st_info) == STT_SECTION)) {
2783 			value = *(long *)roffset;
2784 			*(long *)roffset = 0;
2785 		} else {
2786 			value = sym->st_value;
2787 		}
2788 	}
2789 	return (-(TLSSTATOFF(lmp) - value));
2790 }
2791 
2792 /*
2793  * If the symbol is not found and the reference was not to a weak symbol, report
2794  * an error.  Weak references may be unresolved.
2795  */
2796 int
2797 elf_reloc_error(Rt_map *lmp, const char *name, void *rel, uint_t binfo)
2798 {
2799 	Lm_list	*lml = LIST(lmp);
2800 
2801 	/*
2802 	 * Under crle(1), relocation failures are ignored.
2803 	 */
2804 	if (lml->lm_flags & LML_FLG_IGNRELERR)
2805 		return (1);
2806 
2807 	/*
2808 	 * Under ldd(1), unresolved references are reported.  However, if the
2809 	 * original reference is EXTERN or PARENT these references are ignored
2810 	 * unless ldd's -p option is in effect.
2811 	 */
2812 	if (lml->lm_flags & LML_FLG_TRC_WARN) {
2813 		if (((binfo & DBG_BINFO_REF_MSK) == 0) ||
2814 		    ((lml->lm_flags & LML_FLG_TRC_NOPAREXT) != 0)) {
2815 			(void) printf(MSG_INTL(MSG_LDD_SYM_NFOUND),
2816 			    demangle(name), NAME(lmp));
2817 		}
2818 		return (1);
2819 	}
2820 
2821 	/*
2822 	 * Otherwise, the unresolved references is fatal.
2823 	 */
2824 	DBG_CALL(Dbg_reloc_in(lml, ELF_DBG_RTLD, M_MACH, M_REL_SHT_TYPE, rel,
2825 	    NULL, 0, name));
2826 	eprintf(lml, ERR_FATAL, MSG_INTL(MSG_REL_NOSYM), NAME(lmp),
2827 	    demangle(name));
2828 
2829 	return (0);
2830 }
2831 
2832 /*
2833  * Generic relative relocation function.
2834  */
2835 inline static ulong_t
2836 _elf_reloc_relative(ulong_t rbgn, ulong_t base, Rt_map *lmp, APlist **textrel)
2837 {
2838 	mmapobj_result_t	*mpp;
2839 	ulong_t			roffset;
2840 
2841 	roffset = ((M_RELOC *)rbgn)->r_offset;
2842 	roffset += base;
2843 
2844 	/*
2845 	 * If this relocation is against an address that is not associated with
2846 	 * a mapped segment, fall back to the generic relocation loop to
2847 	 * collect the associated error.
2848 	 */
2849 	if ((mpp = find_segment((caddr_t)roffset, lmp)) == NULL)
2850 		return (0);
2851 
2852 	/*
2853 	 * If this relocation is against a segment that does not provide write
2854 	 * access, set the write permission for all non-writable mappings.
2855 	 */
2856 	if (((mpp->mr_prot & PROT_WRITE) == 0) && textrel &&
2857 	    ((set_prot(lmp, mpp, 1) == 0) ||
2858 	    (aplist_append(textrel, mpp, AL_CNT_TEXTREL) == NULL)))
2859 		return (0);
2860 
2861 	/*
2862 	 * Perform the actual relocation.  Note, for backward compatibility,
2863 	 * SPARC relocations are added to the offset contents (there was a time
2864 	 * when the offset was used to contain the addend, rather than using
2865 	 * the addend itself).
2866 	 */
2867 #if	defined(__sparc)
2868 	*((ulong_t *)roffset) += base + ((M_RELOC *)rbgn)->r_addend;
2869 #elif	defined(__amd64)
2870 	*((ulong_t *)roffset) = base + ((M_RELOC *)rbgn)->r_addend;
2871 #else
2872 	*((ulong_t *)roffset) += base;
2873 #endif
2874 	return (1);
2875 }
2876 
2877 /*
2878  * When a generic relocation loop realizes that it's dealing with relative
2879  * relocations, but no DT_RELCOUNT .dynamic tag is present, this tighter loop
2880  * is entered as an optimization.
2881  */
2882 ulong_t
2883 elf_reloc_relative(ulong_t rbgn, ulong_t rend, ulong_t rsize, ulong_t base,
2884     Rt_map *lmp, APlist **textrel)
2885 {
2886 	char	rtype;
2887 
2888 	do {
2889 		if (_elf_reloc_relative(rbgn, base, lmp, textrel) == 0)
2890 			break;
2891 
2892 		rbgn += rsize;
2893 		if (rbgn >= rend)
2894 			break;
2895 
2896 		/*
2897 		 * Make sure the next type is a relative relocation.
2898 		 */
2899 		rtype = ELF_R_TYPE(((M_RELOC *)rbgn)->r_info, M_MACH);
2900 
2901 	} while (rtype == M_R_RELATIVE);
2902 
2903 	return (rbgn);
2904 }
2905 
2906 /*
2907  * This is the tightest loop for RELATIVE relocations for those objects built
2908  * with the DT_RELACOUNT .dynamic entry.
2909  */
2910 ulong_t
2911 elf_reloc_relative_count(ulong_t rbgn, ulong_t rcount, ulong_t rsize,
2912     ulong_t base, Rt_map *lmp, APlist **textrel)
2913 {
2914 	for (; rcount; rcount--) {
2915 		if (_elf_reloc_relative(rbgn, base, lmp, textrel) == 0)
2916 			break;
2917 
2918 		rbgn += rsize;
2919 	}
2920 	return (rbgn);
2921 }
2922