xref: /illumos-gate/usr/src/cmd/sgs/rtld/common/elf.c (revision 65a89a64c60f3061bbe2381edaacc81660af9a95)
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 
23 /*
24  *	Copyright (c) 1988 AT&T
25  *	  All Rights Reserved
26  *
27  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
28  * Use is subject to license terms.
29  */
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 /*
33  * Object file dependent support for ELF objects.
34  */
35 #include	"_synonyms.h"
36 
37 #include	<stdio.h>
38 #include	<sys/procfs.h>
39 #include	<sys/mman.h>
40 #include	<sys/debug.h>
41 #include	<string.h>
42 #include	<limits.h>
43 #include	<dlfcn.h>
44 #include	"conv.h"
45 #include	"_rtld.h"
46 #include	"_audit.h"
47 #include	"_elf.h"
48 #include	"msg.h"
49 #include	"debug.h"
50 
51 /*
52  * Default and secure dependency search paths.
53  */
54 static Pnode		elf_dflt_dirs[] = {
55 #if	defined(_ELF64)
56 #ifndef	SGS_PRE_UNIFIED_PROCESS
57 	{ MSG_ORIG(MSG_PTH_LIB_64),		0,	MSG_PTH_LIB_64_SIZE,
58 		LA_SER_DEFAULT,			0,	&elf_dflt_dirs[1] },
59 #endif
60 	{ MSG_ORIG(MSG_PTH_USRLIB_64),		0,	MSG_PTH_USRLIB_64_SIZE,
61 		LA_SER_DEFAULT,			0, 0 }
62 #else
63 #ifndef	SGS_PRE_UNIFIED_PROCESS
64 	{ MSG_ORIG(MSG_PTH_LIB),		0,	MSG_PTH_LIB_SIZE,
65 		LA_SER_DEFAULT,			0,	&elf_dflt_dirs[1] },
66 #endif
67 	{ MSG_ORIG(MSG_PTH_USRLIB),		0,	MSG_PTH_USRLIB_SIZE,
68 		LA_SER_DEFAULT,			0, 0 }
69 #endif
70 };
71 
72 static Pnode		elf_secure_dirs[] = {
73 #if	defined(_ELF64)
74 #ifndef	SGS_PRE_UNIFIED_PROCESS
75 	{ MSG_ORIG(MSG_PTH_LIBSE_64),		0,	MSG_PTH_LIBSE_64_SIZE,
76 		LA_SER_SECURE,			0,	&elf_secure_dirs[1] },
77 #endif
78 	{ MSG_ORIG(MSG_PTH_USRLIBSE_64),	0,
79 		MSG_PTH_USRLIBSE_64_SIZE,
80 		LA_SER_SECURE,			0, 0 }
81 #else
82 #ifndef	SGS_PRE_UNIFIED_PROCESS
83 	{ MSG_ORIG(MSG_PTH_LIBSE),		0,	MSG_PTH_LIBSE_SIZE,
84 		LA_SER_SECURE,			0,	&elf_secure_dirs[1] },
85 #endif
86 	{ MSG_ORIG(MSG_PTH_USRLIBSE),		0,	MSG_PTH_USRLIBSE_SIZE,
87 		LA_SER_SECURE,			0, 0 }
88 #endif
89 };
90 
91 /*
92  * Defines for local functions.
93  */
94 static Pnode	*elf_fix_name(const char *, Rt_map *, uint_t);
95 static int	elf_are_u(Rej_desc *);
96 static void	elf_dladdr(ulong_t, Rt_map *, Dl_info *, void **, int);
97 static ulong_t	elf_entry_pt(void);
98 static char	*elf_get_so(const char *, const char *);
99 static Rt_map	*elf_map_so(Lm_list *, Aliste, const char *, const char *, int);
100 static int	elf_needed(Lm_list *, Aliste, Rt_map *);
101 static void	elf_unmap_so(Rt_map *);
102 static int	elf_verify_vers(const char *, Rt_map *, Rt_map *);
103 
104 /*
105  * Functions and data accessed through indirect pointers.
106  */
107 Fct elf_fct = {
108 	elf_are_u,
109 	elf_entry_pt,
110 	elf_map_so,
111 	elf_unmap_so,
112 	elf_needed,
113 	lookup_sym,
114 	elf_reloc,
115 	elf_dflt_dirs,
116 	elf_secure_dirs,
117 	elf_fix_name,
118 	elf_get_so,
119 	elf_dladdr,
120 	dlsym_handle,
121 	elf_verify_vers,
122 	elf_set_prot
123 };
124 
125 
126 /*
127  * Redefine NEEDED name if necessary.
128  */
129 static Pnode *
130 elf_fix_name(const char *name, Rt_map *clmp, uint_t orig)
131 {
132 	/*
133 	 * For ABI compliance, if we are asked for ld.so.1, then really give
134 	 * them libsys.so.1 (the SONAME of libsys.so.1 is ld.so.1).
135 	 */
136 	if (((*name == '/') &&
137 #if	defined(_ELF64)
138 	    (strcmp(name, MSG_ORIG(MSG_PTH_RTLD_64)) == 0)) ||
139 #else
140 	    (strcmp(name, MSG_ORIG(MSG_PTH_RTLD)) == 0)) ||
141 #endif
142 	    (strcmp(name, MSG_ORIG(MSG_FIL_RTLD)) == 0)) {
143 		Pnode	*pnp;
144 
145 		DBG_CALL(Dbg_file_fixname(name, MSG_ORIG(MSG_PTH_LIBSYS)));
146 		if (((pnp = calloc(sizeof (Pnode), 1)) == 0) ||
147 		    ((pnp->p_name = strdup(MSG_ORIG(MSG_PTH_LIBSYS))) == 0)) {
148 			if (pnp)
149 				free(pnp);
150 			return (0);
151 		}
152 		pnp->p_len = MSG_PTH_LIBSYS_SIZE;
153 		pnp->p_orig = (orig & PN_SER_MASK);
154 		return (pnp);
155 	}
156 
157 	return (expand_paths(clmp, name, orig, 0));
158 }
159 
160 /*
161  * Determine if we have been given an ELF file and if so determine if the file
162  * is compatible.  Returns 1 if true, else 0 and sets the reject descriptor
163  * with associated error information.
164  */
165 static int
166 elf_are_u(Rej_desc *rej)
167 {
168 	Ehdr	*ehdr;
169 
170 	/*
171 	 * Determine if we're an elf file.  If not simply return, we don't set
172 	 * any rejection information as this test allows use to scroll through
173 	 * the objects we support (ELF, AOUT).
174 	 */
175 	if (fmap->fm_fsize < sizeof (Ehdr) ||
176 	    fmap->fm_maddr[EI_MAG0] != ELFMAG0 ||
177 	    fmap->fm_maddr[EI_MAG1] != ELFMAG1 ||
178 	    fmap->fm_maddr[EI_MAG2] != ELFMAG2 ||
179 	    fmap->fm_maddr[EI_MAG3] != ELFMAG3) {
180 		return (0);
181 	}
182 
183 	/*
184 	 * Check class and encoding.
185 	 */
186 	/* LINTED */
187 	ehdr = (Ehdr *)fmap->fm_maddr;
188 	if (ehdr->e_ident[EI_CLASS] != M_CLASS) {
189 		rej->rej_type = SGS_REJ_CLASS;
190 		rej->rej_info = (uint_t)ehdr->e_ident[EI_CLASS];
191 		return (0);
192 	}
193 	if (ehdr->e_ident[EI_DATA] != M_DATA) {
194 		rej->rej_type = SGS_REJ_DATA;
195 		rej->rej_info = (uint_t)ehdr->e_ident[EI_DATA];
196 		return (0);
197 	}
198 	if ((ehdr->e_type != ET_REL) && (ehdr->e_type != ET_EXEC) &&
199 	    (ehdr->e_type != ET_DYN)) {
200 		rej->rej_type = SGS_REJ_TYPE;
201 		rej->rej_info = (uint_t)ehdr->e_type;
202 		return (0);
203 	}
204 
205 	/*
206 	 * Verify machine specific flags, and hardware capability requirements.
207 	 */
208 	if ((elf_mach_flags_check(rej, ehdr) == 0) ||
209 	    ((rtld_flags2 & RT_FL2_HWCAP) && (hwcap_check(rej, ehdr) == 0)))
210 		return (0);
211 
212 	/*
213 	 * Verify ELF version.  ??? is this too restrictive ???
214 	 */
215 	if (ehdr->e_version > EV_CURRENT) {
216 		rej->rej_type = SGS_REJ_VERSION;
217 		rej->rej_info = (uint_t)ehdr->e_version;
218 		return (0);
219 	}
220 	return (1);
221 }
222 
223 /*
224  * The runtime linker employs lazy loading to provide the libraries needed for
225  * debugging, preloading .o's and dldump().  As these are seldom used, the
226  * standard startup of ld.so.1 doesn't initialize all the information necessary
227  * to perform plt relocation on ld.so.1's link-map.  The first time lazy loading
228  * is called we get here to perform these initializations:
229  *
230  *  o	elf_needed() is called to set up the DYNINFO() indexes for each lazy
231  *	dependency.  Typically, for all other objects, this is called during
232  *	analyze_so(), but as ld.so.1 is set-contained we skip this processing.
233  *
234  *  o	For intel, ld.so.1's JMPSLOT relocations need relative updates. These
235  *	are by default skipped thus delaying all relative relocation processing
236  * 	on every invocation of ld.so.1.
237  */
238 int
239 elf_rtld_load()
240 {
241 	Lm_list	*lml = &lml_rtld;
242 	Rt_map	*lmp = lml->lm_head;
243 
244 	if (lml->lm_flags & LML_FLG_PLTREL)
245 		return (1);
246 
247 	/*
248 	 * As we need to refer to the DYNINFO() information, insure that it has
249 	 * been initialized.
250 	 */
251 	if (elf_needed(lml, ALO_DATA, lmp) == 0)
252 		return (0);
253 
254 #if	defined(i386)
255 	/*
256 	 * This is a kludge to give ld.so.1 a performance benefit on i386.
257 	 * It's based around two factors.
258 	 *
259 	 *  o	JMPSLOT relocations (PLT's) actually need a relative relocation
260 	 *	applied to the GOT entry so that they can find PLT0.
261 	 *
262 	 *  o	ld.so.1 does not exercise *any* PLT's before it has made a call
263 	 *	to elf_lazy_load().  This is because all dynamic dependencies
264 	 * 	are recorded as lazy dependencies.
265 	 */
266 	(void) elf_reloc_relacount((ulong_t)JMPREL(lmp),
267 	    (ulong_t)(PLTRELSZ(lmp) / RELENT(lmp)), (ulong_t)RELENT(lmp),
268 	    (ulong_t)ADDR(lmp));
269 #endif
270 
271 	lml->lm_flags |= LML_FLG_PLTREL;
272 	return (1);
273 }
274 
275 /*
276  * Lazy load an object.
277  */
278 Rt_map *
279 elf_lazy_load(Rt_map *clmp, uint_t ndx, const char *sym)
280 {
281 	Rt_map		*nlmp, *hlmp;
282 	Dyninfo		*dip = &DYNINFO(clmp)[ndx];
283 	uint_t		flags = 0;
284 	Pnode		*pnp;
285 	const char	*name;
286 	Lm_list		*lml = LIST(clmp);
287 	Lm_cntl		*lmc;
288 	Aliste		lmco;
289 
290 	/*
291 	 * If this dependency has already been processed, we're done.
292 	 */
293 	if (((nlmp = (Rt_map *)dip->di_info) != 0) ||
294 	    (dip->di_flags & FLG_DI_PROCESSD))
295 		return (nlmp);
296 
297 	/*
298 	 * Determine the initial dependency name, and indicate that this
299 	 * dependencies processing has initiated.
300 	 */
301 	name = STRTAB(clmp) + DYN(clmp)[ndx].d_un.d_val;
302 	DBG_CALL(Dbg_file_lazyload(name, NAME(clmp), sym));
303 	if (lml->lm_flags & LML_FLG_TRC_ENABLE)
304 		dip->di_flags |= FLG_DI_PROCESSD;
305 
306 	if (dip->di_flags & FLG_DI_GROUP)
307 		flags |= (FLG_RT_SETGROUP | FLG_RT_HANDLE);
308 
309 	/*
310 	 * Expand the requested name if necessary.
311 	 */
312 	if ((pnp = elf_fix_name(name, clmp, PN_SER_NEEDED)) == 0)
313 		return (0);
314 
315 	/*
316 	 * Provided the object on the head of the link-map has completed its
317 	 * relocation, create a new link-map control list for this request.
318 	 */
319 	hlmp = lml->lm_head;
320 	if (FLAGS(hlmp) & FLG_RT_RELOCED) {
321 		if ((lmc = alist_append(&(lml->lm_lists), 0, sizeof (Lm_cntl),
322 		    AL_CNT_LMLISTS)) == 0) {
323 			remove_pnode(pnp);
324 			return (0);
325 		}
326 		lmco = (Aliste)((char *)lmc - (char *)lml->lm_lists);
327 	} else {
328 		lmc = 0;
329 		lmco = ALO_DATA;
330 	}
331 
332 	/*
333 	 * Load the associated object.
334 	 */
335 	dip->di_info = nlmp =
336 	    load_one(lml, lmco, pnp, clmp, MODE(clmp), flags, 0);
337 
338 	/*
339 	 * Remove any expanded pathname infrastructure.  Reduce the pending lazy
340 	 * dependency count of the caller, together with the link-map lists
341 	 * count of objects that still have lazy dependencies pending.
342 	 */
343 	remove_pnode(pnp);
344 	if (--LAZY(clmp) == 0)
345 		LIST(clmp)->lm_lazy--;
346 
347 	/*
348 	 * Finish processing the objects associated with this request.
349 	 */
350 	if (nlmp && ((analyze_lmc(lml, lmco, nlmp) == 0) ||
351 	    (relocate_lmc(lml, lmco, nlmp) == 0)))
352 		dip->di_info = nlmp = 0;
353 
354 	/*
355 	 * If the dependency has been successfully processed, and it is part of
356 	 * a link-map control list that is equivalent, or less, that the callers
357 	 * control list, create an association between the caller and this
358 	 * dependency.  If this dependency isn't yet apart of the callers
359 	 * link-map control list, then it is still apart of a list that is being
360 	 * relocated.  As the relocation of an object on this list might still
361 	 * fail, we can't yet bind the caller to this object.  To do so, would
362 	 * be locking the object so that it couldn't be deleted.  Mark this
363 	 * object as free, and it will be reprocessed when this dependency is
364 	 * next referenced.
365 	 */
366 	if (nlmp) {
367 		if (CNTL(nlmp) <= CNTL(clmp)) {
368 			if (bind_one(clmp, nlmp, BND_NEEDED) == 0)
369 				dip->di_info = nlmp = 0;
370 		} else {
371 			dip->di_info = 0;
372 			dip->di_flags &= ~FLG_DI_PROCESSD;
373 			if (LAZY(clmp)++ == 0)
374 				LIST(clmp)->lm_lazy++;
375 		}
376 	}
377 
378 	/*
379 	 * After a successful load, any objects collected on the new link-map
380 	 * control list will have been moved to the callers link-map control
381 	 * list.  This control list can now be deleted.
382 	 */
383 	if (lmc) {
384 		if (nlmp == 0)
385 			remove_incomplete(lml, lmco);
386 		remove_cntl(lml, lmco);
387 	}
388 
389 	return (nlmp);
390 }
391 
392 
393 /*
394  * Return the entry point of the ELF executable.
395  */
396 static ulong_t
397 elf_entry_pt(void)
398 {
399 	return (ENTRY(lml_main.lm_head));
400 }
401 
402 /*
403  * Unmap a given ELF shared object from the address space.
404  */
405 static void
406 elf_unmap_so(Rt_map *lmp)
407 {
408 	caddr_t	addr;
409 	size_t	size;
410 	Mmap	*mmaps;
411 
412 	/*
413 	 * If this link map represents a relocatable object concatenation, then
414 	 * the image was simply generated in allocated memory.  Free the memory.
415 	 *
416 	 * Note: the memory was originally allocated in the libelf:_elf_outmap
417 	 * routine and would normally have been free'd in elf_outsync(), but
418 	 * because we 'interpose' on that routine the memory  wasn't free'd at
419 	 * that time.
420 	 */
421 	if (FLAGS(lmp) & FLG_RT_IMGALLOC) {
422 		free((void *)ADDR(lmp));
423 		return;
424 	}
425 
426 	/*
427 	 * If padding was enabled via rtld_db, then we have at least one page
428 	 * in front of the image - and possibly a trailing page.
429 	 * Unmap the front page first:
430 	 */
431 	if (PADSTART(lmp) != ADDR(lmp)) {
432 		addr = (caddr_t)M_PTRUNC(PADSTART(lmp));
433 		size = ADDR(lmp) - (ulong_t)addr;
434 		(void) munmap(addr, size);
435 	}
436 
437 	/*
438 	 * Unmap any trailing padding.
439 	 */
440 	if (M_PROUND((PADSTART(lmp) + PADIMLEN(lmp))) >
441 	    M_PROUND(ADDR(lmp) + MSIZE(lmp))) {
442 		addr = (caddr_t)M_PROUND(ADDR(lmp) + MSIZE(lmp));
443 		size = M_PROUND(PADSTART(lmp) + PADIMLEN(lmp)) - (ulong_t)addr;
444 		(void) munmap(addr, size);
445 	}
446 
447 	/*
448 	 * Unmmap all mapped segments.
449 	 */
450 	for (mmaps = MMAPS(lmp); mmaps->m_vaddr; mmaps++)
451 		(void) munmap(mmaps->m_vaddr, mmaps->m_msize);
452 }
453 
454 /*
455  * Determine if a dependency requires a particular version and if so verify
456  * that the version exists in the dependency.
457  */
458 static int
459 elf_verify_vers(const char *name, Rt_map *clmp, Rt_map *nlmp)
460 {
461 	Verneed		*vnd = VERNEED(clmp);
462 	int		_num, num = VERNEEDNUM(clmp);
463 	char		*cstrs = (char *)STRTAB(clmp);
464 	Lm_list		*lml = LIST(clmp);
465 
466 	/*
467 	 * Traverse the callers version needed information and determine if any
468 	 * specific versions are required from the dependency.
469 	 */
470 	for (_num = 1; _num <= num; _num++,
471 	    vnd = (Verneed *)((Xword)vnd + vnd->vn_next)) {
472 		Half		cnt = vnd->vn_cnt;
473 		Vernaux		*vnap;
474 		char		*nstrs, *need;
475 
476 		/*
477 		 * Determine if a needed entry matches this dependency.
478 		 */
479 		need = (char *)(cstrs + vnd->vn_file);
480 		if (strcmp(name, need) != 0)
481 			continue;
482 
483 		DBG_CALL(Dbg_ver_need_title(NAME(clmp)));
484 		if ((lml->lm_flags & LML_FLG_TRC_VERBOSE) &&
485 		    ((FLAGS1(clmp) & FL1_RT_LDDSTUB) == 0))
486 			(void) printf(MSG_INTL(MSG_LDD_VER_FIND), name);
487 
488 		/*
489 		 * Validate that each version required actually exists in the
490 		 * dependency.
491 		 */
492 		nstrs = (char *)STRTAB(nlmp);
493 
494 		for (vnap = (Vernaux *)((Xword)vnd + vnd->vn_aux); cnt;
495 		    cnt--, vnap = (Vernaux *)((Xword)vnap + vnap->vna_next)) {
496 			char		*version, *define;
497 			Verdef		*vdf = VERDEF(nlmp);
498 			ulong_t		_num, num = VERDEFNUM(nlmp);
499 			int		found = 0;
500 
501 			version = (char *)(cstrs + vnap->vna_name);
502 			DBG_CALL(Dbg_ver_need_entry(0, need, version));
503 
504 			for (_num = 1; _num <= num; _num++,
505 			    vdf = (Verdef *)((Xword)vdf + vdf->vd_next)) {
506 				Verdaux		*vdap;
507 
508 				if (vnap->vna_hash != vdf->vd_hash)
509 					continue;
510 
511 				vdap = (Verdaux *)((Xword)vdf + vdf->vd_aux);
512 				define = (char *)(nstrs + vdap->vda_name);
513 				if (strcmp(version, define) != 0)
514 					continue;
515 
516 				found++;
517 				break;
518 			}
519 
520 			/*
521 			 * If we're being traced print out any matched version
522 			 * when the verbose (-v) option is in effect.  Always
523 			 * print any unmatched versions.
524 			 */
525 			if (lml->lm_flags & LML_FLG_TRC_ENABLE) {
526 				if (found) {
527 				    if (!(lml->lm_flags & LML_FLG_TRC_VERBOSE))
528 					continue;
529 
530 				    (void) printf(MSG_ORIG(MSG_LDD_VER_FOUND),
531 					need, version, NAME(nlmp));
532 				} else {
533 				    if (rtld_flags & RT_FL_SILENCERR)
534 					continue;
535 
536 				    (void) printf(MSG_INTL(MSG_LDD_VER_NFOUND),
537 					need, version);
538 				}
539 				continue;
540 			}
541 
542 			/*
543 			 * If the version hasn't been found then this is a
544 			 * candidate for a fatal error condition.  Weak
545 			 * version definition requirements are silently
546 			 * ignored.  Also, if the image inspected for a version
547 			 * definition has no versioning recorded at all then
548 			 * silently ignore this (this provides better backward
549 			 * compatibility to old images created prior to
550 			 * versioning being available).  Both of these skipped
551 			 * diagnostics are available under tracing (see above).
552 			 */
553 			if ((found == 0) && (num != 0) &&
554 			    (!(vnap->vna_flags & VER_FLG_WEAK))) {
555 				eprintf(ERR_FATAL, MSG_INTL(MSG_VER_NFOUND),
556 				    need, version, NAME(clmp));
557 				return (0);
558 			}
559 		}
560 		return (1);
561 	}
562 	return (1);
563 }
564 
565 /*
566  * Search through the dynamic section for DT_NEEDED entries and perform one
567  * of two functions.  If only the first argument is specified then load the
568  * defined shared object, otherwise add the link map representing the defined
569  * link map the the dlopen list.
570  */
571 static int
572 elf_needed(Lm_list *lml, Aliste lmco, Rt_map *clmp)
573 {
574 	Dyn		*dyn;
575 	ulong_t		ndx = 0;
576 	uint_t		lazy = 0, flags = 0;
577 	Word		lmflags = lml->lm_flags;
578 	Word		lmtflags = lml->lm_tflags;
579 
580 	/*
581 	 * Process each shared object on needed list.
582 	 */
583 	if (DYN(clmp) == 0)
584 		return (1);
585 
586 	for (dyn = (Dyn *)DYN(clmp); dyn->d_tag != DT_NULL; dyn++, ndx++) {
587 		Dyninfo	*dip = &DYNINFO(clmp)[ndx];
588 		Rt_map	*nlmp = 0;
589 		char	*name;
590 		int	silent = 0;
591 		Pnode	*pnp;
592 
593 		switch (dyn->d_tag) {
594 		case DT_POSFLAG_1:
595 			if ((dyn->d_un.d_val & DF_P1_LAZYLOAD) &&
596 			    !(lmtflags & LML_TFLG_NOLAZYLD))
597 				lazy = 1;
598 			if (dyn->d_un.d_val & DF_P1_GROUPPERM)
599 				flags = (FLG_RT_SETGROUP | FLG_RT_HANDLE);
600 			continue;
601 		case DT_NEEDED:
602 		case DT_USED:
603 			dip->di_flags |= FLG_DI_NEEDED;
604 			if (flags)
605 				dip->di_flags |= FLG_DI_GROUP;
606 
607 			name = (char *)STRTAB(clmp) + dyn->d_un.d_val;
608 
609 			/*
610 			 * NOTE, libc.so.1 can't be lazy loaded.  Although a
611 			 * lazy position flag won't be produced when a RTLDINFO
612 			 * .dynamic entry is found (introduced with the UPM in
613 			 * Solaris 10), it was possible to mark libc for lazy
614 			 * loading on previous releases.  To reduce the overhead
615 			 * of testing for this occurrence, only carry out this
616 			 * check for the first object on the link-map list
617 			 * (there aren't many applications built without libc).
618 			 */
619 			if (lazy && (lml->lm_head == clmp) &&
620 			    (strcmp(name, MSG_ORIG(MSG_FIL_LIBC)) == 0))
621 				lazy = 0;
622 
623 			/*
624 			 * Don't bring in lazy loaded objects yet unless we've
625 			 * been asked to attempt to load all available objects
626 			 * (crle(1) sets LD_FLAGS=loadavail).  Even under
627 			 * RTLD_NOW we don't process this - RTLD_NOW will cause
628 			 * relocation processing which in turn might trigger
629 			 * lazy loading, but its possible that the object has a
630 			 * lazy loaded file with no bindings (i.e., it should
631 			 * never have been a dependency in the first place).
632 			 */
633 			if (lazy) {
634 				if ((lmflags & LML_FLG_LOADAVAIL) == 0) {
635 					LAZY(clmp)++;
636 					lazy = flags = 0;
637 					continue;
638 				}
639 
640 				/*
641 				 * Silence any error messages - see description
642 				 * under elf_lookup_filtee().
643 				 */
644 				if ((rtld_flags & RT_FL_SILENCERR) == 0) {
645 					rtld_flags |= RT_FL_SILENCERR;
646 					silent = 1;
647 				}
648 			}
649 			break;
650 		case DT_AUXILIARY:
651 			dip->di_flags |= FLG_DI_AUXFLTR;
652 			lazy = flags = 0;
653 			continue;
654 		case DT_SUNW_AUXILIARY:
655 			dip->di_flags |= (FLG_DI_AUXFLTR | FLG_DI_SYMFLTR);
656 			lazy = flags = 0;
657 			continue;
658 		case DT_FILTER:
659 			dip->di_flags |= FLG_DI_STDFLTR;
660 			lazy = flags = 0;
661 			continue;
662 		case DT_SUNW_FILTER:
663 			dip->di_flags |= (FLG_DI_STDFLTR | FLG_DI_SYMFLTR);
664 			lazy = flags = 0;
665 			continue;
666 		default:
667 			lazy = flags = 0;
668 			continue;
669 		}
670 
671 		DBG_CALL(Dbg_file_needed(name, NAME(clmp)));
672 		if (lml->lm_flags & LML_FLG_TRC_ENABLE)
673 			dip->di_flags |= FLG_DI_PROCESSD;
674 
675 		/*
676 		 * Establish the objects name, load it and establish a binding
677 		 * with the caller.
678 		 */
679 		if (((pnp = elf_fix_name(name, clmp, PN_SER_NEEDED)) == 0) ||
680 		    ((nlmp = load_one(lml, lmco, pnp, clmp, MODE(clmp),
681 		    flags, 0)) == 0) || (bind_one(clmp, nlmp, BND_NEEDED) == 0))
682 			nlmp = 0;
683 
684 		/*
685 		 * Clean up any infrastructure, including the removal of the
686 		 * error suppression state, if it had been previously set in
687 		 * this routine.
688 		 */
689 		if (pnp)
690 			remove_pnode(pnp);
691 		if (silent)
692 			rtld_flags &= ~RT_FL_SILENCERR;
693 		lazy = flags = 0;
694 		if ((dip->di_info = (void *)nlmp) == 0) {
695 			/*
696 			 * If the object could not be mapped, continue if error
697 			 * suppression is established or we're here with ldd(1).
698 			 */
699 			if ((MODE(clmp) & RTLD_CONFGEN) || (lmflags &
700 			    (LML_FLG_LOADAVAIL | LML_FLG_TRC_ENABLE)))
701 				continue;
702 			else
703 				return (0);
704 		}
705 	}
706 
707 	if (LAZY(clmp))
708 		lml->lm_lazy++;
709 
710 	return (1);
711 }
712 
713 static int
714 elf_map_check(const char *name, caddr_t vaddr, Off size)
715 {
716 	prmap_t		*maps, *_maps;
717 	int		pfd, num, _num;
718 	caddr_t		eaddr = vaddr + size;
719 	int		err;
720 
721 	/*
722 	 * If memory reservations have been established for alternative objects
723 	 * determine if this object falls within the reservation, if it does no
724 	 * further checking is required.
725 	 */
726 	if (rtld_flags & RT_FL_MEMRESV) {
727 		Rtc_head	*head = (Rtc_head *)config->c_bgn;
728 
729 		if ((vaddr >= (caddr_t)(uintptr_t)head->ch_resbgn) &&
730 		    (eaddr <= (caddr_t)(uintptr_t)head->ch_resend))
731 			return (0);
732 	}
733 
734 	/*
735 	 * Determine the mappings presently in use by this process.
736 	 */
737 	if ((pfd = pr_open()) == FD_UNAVAIL)
738 		return (1);
739 
740 	if (ioctl(pfd, PIOCNMAP, (void *)&num) == -1) {
741 		err = errno;
742 		eprintf(ERR_FATAL, MSG_INTL(MSG_SYS_PROC), name, strerror(err));
743 		return (1);
744 	}
745 
746 	if ((maps = malloc((num + 1) * sizeof (prmap_t))) == 0)
747 		return (1);
748 
749 	if (ioctl(pfd, PIOCMAP, (void *)maps) == -1) {
750 		err = errno;
751 		eprintf(ERR_FATAL, MSG_INTL(MSG_SYS_PROC), name, strerror(err));
752 		free(maps);
753 		return (1);
754 	}
755 
756 	/*
757 	 * Determine if the supplied address clashes with any of the present
758 	 * process mappings.
759 	 */
760 	for (_num = 0, _maps = maps; _num < num; _num++, _maps++) {
761 		caddr_t		_eaddr = _maps->pr_vaddr + _maps->pr_size;
762 		Rt_map		*lmp;
763 		const char	*str;
764 
765 		if ((eaddr < _maps->pr_vaddr) || (vaddr >= _eaddr))
766 			continue;
767 
768 		/*
769 		 * We have a memory clash.  See if one of the known dynamic
770 		 * dependency mappings represents this space so as to provide
771 		 * the user a more meaningful message.
772 		 */
773 		if ((lmp = _caller(vaddr, 0)) != 0)
774 			str = NAME(lmp);
775 		else
776 			str = MSG_INTL(MSG_STR_UNKNOWN);
777 
778 		eprintf(ERR_FATAL, MSG_INTL(MSG_GEN_MAPINUSE), name,
779 		    EC_ADDR(vaddr), EC_OFF(size), str);
780 		return (1);
781 	}
782 	free(maps);
783 	return (0);
784 }
785 
786 /*
787  * Obtain a memory reservation.  On newer systems, both MAP_ANON and MAP_ALIGN
788  * are used to obtained an aligned reservation from anonymous memory.  If
789  * MAP_ANON isn't available, then MAP_ALIGN isn't either, so obtain a standard
790  * reservation using the file as backing.
791  */
792 static Am_ret
793 elf_map_reserve(const char *name, caddr_t *maddr, Off msize, int mperm,
794     int fd, Xword align)
795 {
796 	Am_ret	amret;
797 	int	mflag = MAP_PRIVATE | MAP_NORESERVE;
798 
799 #if defined(MAP_ALIGN)
800 	if ((rtld_flags2 & RT_FL2_NOMALIGN) == 0) {
801 		mflag |= MAP_ALIGN;
802 		*maddr = (caddr_t)align;
803 	}
804 #endif
805 	if ((amret = anon_map(maddr, msize, PROT_NONE, mflag)) == AM_ERROR)
806 		return (amret);
807 
808 	if (amret == AM_OK)
809 		return (AM_OK);
810 
811 	/*
812 	 * If an anonymous memory request failed (which should only be the
813 	 * case if it is unsupported on the system we're running on), establish
814 	 * the initial mapping directly from the file.
815 	 */
816 	*maddr = 0;
817 	if ((*maddr = mmap(*maddr, msize, mperm, MAP_PRIVATE,
818 	    fd, 0)) == MAP_FAILED) {
819 		int	err = errno;
820 		eprintf(ERR_FATAL, MSG_INTL(MSG_SYS_MMAP), name, strerror(err));
821 		return (AM_ERROR);
822 	}
823 	return (AM_NOSUP);
824 }
825 
826 static void *
827 elf_map_textdata(caddr_t addr, Off flen, int mperm, int phdr_mperm, int mflag,
828     int fd, Off foff)
829 {
830 #if	defined(MAP_TEXT) && defined(MAP_INITDATA)
831 	static int	notd = 0;
832 
833 	/*
834 	 * If MAP_TEXT and MAP_INITDATA are available, select the appropriate
835 	 * flag.
836 	 */
837 	if (notd == 0) {
838 		if ((phdr_mperm & (PROT_WRITE | PROT_EXEC)) == PROT_EXEC)
839 			mflag |= MAP_TEXT;
840 		else
841 			mflag |= MAP_INITDATA;
842 	}
843 #endif
844 	if (mmap((caddr_t)addr, flen, mperm, mflag, fd, foff) != MAP_FAILED)
845 		return (0);
846 
847 #if	defined(MAP_TEXT) && defined(MAP_INITDATA)
848 	if ((notd == 0) && (errno == EINVAL)) {
849 		/*
850 		 * MAP_TEXT and MAP_INITDATA may not be supported on this
851 		 * platform, try again without.
852 		 */
853 		notd = 1;
854 		mflag &= ~(MAP_TEXT | MAP_INITDATA);
855 
856 		return (mmap((caddr_t)addr, flen, mperm, mflag, fd, foff));
857 	}
858 #endif
859 	return (MAP_FAILED);
860 }
861 
862 /*
863  * Map in a file.
864  */
865 static caddr_t
866 elf_map_it(
867 	const char	*name,		/* actual name stored for pathname */
868 	Off		fsize,		/* total mapping claim of the file */
869 	Ehdr		*ehdr,		/* ELF header of file */
870 	Phdr		*fphdr,		/* first loadable Phdr */
871 	Phdr		*lphdr,		/* last loadable Phdr */
872 	Phdr		**rrphdr,	/* return first Phdr in reservation */
873 	caddr_t		*rraddr,	/* return start of reservation */
874 	Off		*rrsize,	/* return total size of reservation */
875 	int		fixed,		/* image is resolved to a fixed addr */
876 	int		fd,		/* images file descriptor */
877 	Xword		align,		/* image segments maximum alignment */
878 	Mmap		*mmaps,		/* mmap information array and */
879 	uint_t		*mmapcnt)	/* 	mapping count */
880 {
881 	caddr_t		raddr;		/* reservation address */
882 	Off		rsize;		/* reservation size */
883 	Phdr		*phdr;		/* working program header poiner */
884 	caddr_t		maddr;		/* working mmap address */
885 	caddr_t		faddr;		/* working file address */
886 	size_t		padsize;	/* object padding requirement */
887 	size_t		padpsize = 0;	/* padding size rounded to next page */
888 	size_t		padmsize = 0;	/* padding size rounded for alignment */
889 	int		skipfseg;	/* skip mapping first segment */
890 	int		mperm;		/* segment permissions */
891 	Am_ret		amret = AM_NOSUP;
892 
893 	/*
894 	 * If padding is required extend both the front and rear of the image.
895 	 * To insure the image itself is mapped at the correct alignment the
896 	 * initial padding is rounded up to the nearest page.  Once the image is
897 	 * mapped the excess can be pruned to the nearest page required for the
898 	 * actual padding itself.
899 	 */
900 	if ((padsize = r_debug.rtd_objpad) != 0) {
901 		padpsize = M_PROUND(padsize);
902 		if (fixed)
903 			padmsize = padpsize;
904 		else
905 			padmsize = S_ROUND(padsize, align);
906 	}
907 
908 	/*
909 	 * Determine the initial permissions used to map in the first segment.
910 	 * If this segments memsz is greater that its filesz then the difference
911 	 * must be zeroed.  Make sure this segment is writable.
912 	 */
913 	mperm = 0;
914 	if (fphdr->p_flags & PF_R)
915 		mperm |= PROT_READ;
916 	if (fphdr->p_flags & PF_X)
917 		mperm |= PROT_EXEC;
918 	if ((fphdr->p_flags & PF_W) || (fphdr->p_memsz > fphdr->p_filesz))
919 		mperm |= PROT_WRITE;
920 
921 	/*
922 	 * Determine whether or not to let system reserve address space based on
923 	 * whether this is a dynamic executable (addresses in object are fixed)
924 	 * or a shared object (addresses in object are relative to the objects'
925 	 * base).
926 	 */
927 	if (fixed) {
928 		/*
929 		 * Determine the reservation address and size, and insure that
930 		 * this reservation isn't already in use.
931 		 */
932 		faddr = maddr = (caddr_t)M_PTRUNC((ulong_t)fphdr->p_vaddr);
933 		raddr = maddr - padpsize;
934 		rsize = fsize + padpsize + padsize;
935 
936 		if (lml_main.lm_head) {
937 			if (elf_map_check(name, raddr, rsize) != 0)
938 				return (0);
939 		}
940 
941 		/*
942 		 * As this is a fixed image, all segments must be individually
943 		 * mapped.
944 		 */
945 		skipfseg = 0;
946 
947 	} else {
948 		size_t	esize;
949 
950 		/*
951 		 * If this isn't a fixed image, reserve enough address space for
952 		 * the entire image to be mapped.  The amount of reservation is
953 		 * the range between the beginning of the first, and end of the
954 		 * last loadable segment, together with any padding, plus the
955 		 * alignment of the first segment.
956 		 *
957 		 * The optimal reservation is made as a no-reserve mapping from
958 		 * anonymous memory.  Each segment is then mapped into this
959 		 * reservation.  If the anonymous mapping capability isn't
960 		 * available, the reservation is obtained from the file itself.
961 		 * In this case the first segment of the image is mapped as part
962 		 * of the reservation, thus only the following segments need to
963 		 * be remapped.
964 		 */
965 		rsize = fsize + padmsize + padsize;
966 		if ((amret = elf_map_reserve(name, &raddr, rsize, mperm,
967 		    fd, align)) == AM_ERROR)
968 			return (0);
969 		maddr = raddr + padmsize;
970 		faddr = (caddr_t)S_ROUND((Off)maddr, align);
971 
972 		/*
973 		 * If this reservation has been obtained from anonymous memory,
974 		 * then all segments must be individually mapped.  Otherwise,
975 		 * the first segment heads the reservation.
976 		 */
977 		if (amret == AM_OK)
978 			skipfseg = 0;
979 		else
980 			skipfseg = 1;
981 
982 		/*
983 		 * For backward compatibility (where MAP_ALIGN isn't available),
984 		 * insure the alignment of the reservation is adequate for this
985 		 * object, and if not remap the object to obtain the correct
986 		 * alignment.
987 		 */
988 		if (faddr != maddr) {
989 			(void) munmap(raddr, rsize);
990 
991 			rsize += align;
992 			if ((amret = elf_map_reserve(name, &raddr, rsize, mperm,
993 			    fd, align)) == AM_ERROR)
994 				return (0);
995 
996 			maddr = faddr = (caddr_t)S_ROUND((Off)(raddr +
997 			    padpsize), align);
998 
999 			esize = maddr - raddr + padpsize;
1000 
1001 			/*
1002 			 * As ths image has been realigned, the first segment
1003 			 * of the file needs to be remapped to its correct
1004 			 * location.
1005 			 */
1006 			skipfseg = 0;
1007 		} else
1008 			esize = padmsize - padpsize;
1009 
1010 		/*
1011 		 * If this reservation included padding, remove any excess for
1012 		 * the start of the image (the padding was adjusted to insure
1013 		 * the image was aligned appropriately).
1014 		 */
1015 		if (esize) {
1016 			(void) munmap(raddr, esize);
1017 			raddr += esize;
1018 			rsize -= esize;
1019 		}
1020 	}
1021 
1022 	/*
1023 	 * At this point we know the initial location of the image, and its
1024 	 * size.  Pass these back to the caller for inclusion in the link-map
1025 	 * that will eventually be created.
1026 	 */
1027 	*rraddr = raddr;
1028 	*rrsize = rsize;
1029 
1030 	/*
1031 	 * The first loadable segment is now pointed to by maddr.  This segment
1032 	 * will eventually contain the elf header and program headers, so reset
1033 	 * the program header.  Pass this  back to the caller for inclusion in
1034 	 * the link-map so it can be used for later unmapping operations.
1035 	 */
1036 	/* LINTED */
1037 	*rrphdr = (Phdr *)((char *)maddr + ehdr->e_phoff);
1038 
1039 	/*
1040 	 * If padding is required at the front of the image, obtain that now.
1041 	 * Note, if we've already obtained a reservation from anonymous memory
1042 	 * then this reservation will already include suitable padding.
1043 	 * Otherwise this reservation is backed by the file, or in the case of
1044 	 * a fixed image, doesn't yet exist.  Map the padding so that it is
1045 	 * suitably protected (PROT_NONE), and insure the first segment of the
1046 	 * file is mapped to its correct location.
1047 	 */
1048 	if (padsize) {
1049 		if (amret == AM_NOSUP) {
1050 			if (dz_map(raddr, padpsize, PROT_NONE, (MAP_PRIVATE |
1051 			    MAP_FIXED | MAP_NORESERVE)) == MAP_FAILED)
1052 				return (0);
1053 
1054 			skipfseg = 0;
1055 		}
1056 		rsize -= padpsize;
1057 	}
1058 
1059 	/*
1060 	 * Map individual segments.  For a fixed image, these will each be
1061 	 * unique mappings.  For a reservation these will fill in the
1062 	 * reservation.
1063 	 */
1064 	for (phdr = fphdr; phdr <= lphdr;
1065 	    phdr = (Phdr *)((Off)phdr + ehdr->e_phentsize)) {
1066 		caddr_t	addr;
1067 		Off	mlen, flen;
1068 		size_t	size;
1069 
1070 		/*
1071 		 * Skip non-loadable segments or segments that don't occupy
1072 		 * any memory.
1073 		 */
1074 		if (((phdr->p_type != PT_LOAD) &&
1075 		    (phdr->p_type != PT_SUNWBSS)) || (phdr->p_memsz == 0))
1076 			continue;
1077 
1078 		/*
1079 		 * Establish this segments address relative to our base.
1080 		 */
1081 		addr = (caddr_t)M_PTRUNC((ulong_t)(phdr->p_vaddr +
1082 		    (fixed ? 0 : faddr)));
1083 
1084 		/*
1085 		 * Determine the mapping protection from the segment attributes.
1086 		 * Also determine the etext address from the last loadable
1087 		 * segment which has permissions but no write access.
1088 		 */
1089 		mperm = 0;
1090 		if (phdr->p_flags) {
1091 			if (phdr->p_flags & PF_R)
1092 				mperm |= PROT_READ;
1093 			if (phdr->p_flags & PF_X)
1094 				mperm |= PROT_EXEC;
1095 			if (phdr->p_flags & PF_W)
1096 				mperm |= PROT_WRITE;
1097 			else
1098 				fmap->fm_etext = phdr->p_vaddr + phdr->p_memsz +
1099 				    (ulong_t)(fixed ? 0 : faddr);
1100 		}
1101 
1102 		/*
1103 		 * Determine the type of mapping required.
1104 		 */
1105 		if (phdr->p_type == PT_SUNWBSS) {
1106 			/*
1107 			 * Potentially, we can defer the loading of any SUNWBSS
1108 			 * segment, depending on whether the symbols it provides
1109 			 * have been bound to.  In this manner, large segments
1110 			 * that are interposed upon between shared libraries
1111 			 * may not require mapping.  Note, that the mapping
1112 			 * information is recorded in our mapping descriptor at
1113 			 * this time.
1114 			 */
1115 			mlen = phdr->p_memsz;
1116 			flen = 0;
1117 
1118 		} else if ((phdr->p_filesz == 0) && (phdr->p_flags == 0)) {
1119 			/*
1120 			 * If this segment has no backing file and no flags
1121 			 * specified, then it defines a reservation.  At this
1122 			 * point all standard loadable segments will have been
1123 			 * processed.  The segment reservation is mapped
1124 			 * directly from /dev/null.
1125 			 */
1126 			if (nu_map((caddr_t)addr, phdr->p_memsz, PROT_NONE,
1127 			    MAP_FIXED | MAP_PRIVATE) == MAP_FAILED)
1128 				return (0);
1129 
1130 			mlen = phdr->p_memsz;
1131 			flen = 0;
1132 
1133 		} else if (phdr->p_filesz == 0) {
1134 			/*
1135 			 * If this segment has no backing file then it defines a
1136 			 * nobits segment and is mapped directly from /dev/zero.
1137 			 */
1138 			if (dz_map((caddr_t)addr, phdr->p_memsz, mperm,
1139 			    MAP_FIXED | MAP_PRIVATE) == MAP_FAILED)
1140 				return (0);
1141 
1142 			mlen = phdr->p_memsz;
1143 			flen = 0;
1144 
1145 		} else {
1146 			Off	foff;
1147 
1148 			/*
1149 			 * This mapping originates from the file.  Determine the
1150 			 * file offset to which the mapping will be directed
1151 			 * (must be aligned) and how much to map (might be more
1152 			 * than the file in the case of .bss).
1153 			 */
1154 			foff = M_PTRUNC((ulong_t)phdr->p_offset);
1155 			mlen = phdr->p_memsz + (phdr->p_offset - foff);
1156 			flen = phdr->p_filesz + (phdr->p_offset - foff);
1157 
1158 			/*
1159 			 * If this is a non-fixed, non-anonymous mapping, and no
1160 			 * padding is involved, then the first loadable segment
1161 			 * is already part of the initial reservation.  In this
1162 			 * case there is no need to remap this segment.
1163 			 */
1164 			if ((skipfseg == 0) || (phdr != fphdr)) {
1165 				int phdr_mperm = mperm;
1166 				/*
1167 				 * If this segments memsz is greater that its
1168 				 * filesz then the difference must be zeroed.
1169 				 * Make sure this segment is writable.
1170 				 */
1171 				if (phdr->p_memsz > phdr->p_filesz)
1172 					mperm |= PROT_WRITE;
1173 
1174 				if (elf_map_textdata((caddr_t)addr, flen,
1175 				    mperm, phdr_mperm,
1176 				    (MAP_FIXED | MAP_PRIVATE), fd, foff) ==
1177 				    MAP_FAILED) {
1178 					int	err = errno;
1179 					eprintf(ERR_FATAL,
1180 					    MSG_INTL(MSG_SYS_MMAP), name,
1181 					    strerror(err));
1182 					return (0);
1183 				}
1184 			}
1185 
1186 			/*
1187 			 * If the memory occupancy of the segment overflows the
1188 			 * definition in the file, we need to "zero out" the end
1189 			 * of the mapping we've established, and if necessary,
1190 			 * map some more space from /dev/zero.  Note, zero'ed
1191 			 * memory must end on a double word boundary to satisfy
1192 			 * zero().
1193 			 */
1194 			if (phdr->p_memsz > phdr->p_filesz) {
1195 				caddr_t	zaddr;
1196 				size_t	zlen, zplen;
1197 				Off	fend;
1198 
1199 				foff = (Off)(phdr->p_vaddr + phdr->p_filesz +
1200 				    (fixed ? 0 : faddr));
1201 				zaddr = (caddr_t)M_PROUND(foff);
1202 				zplen = (size_t)(zaddr - foff);
1203 
1204 				fend = (Off)S_DROUND((size_t)(phdr->p_vaddr +
1205 				    phdr->p_memsz + (fixed ? 0 : faddr)));
1206 				zlen = (size_t)(fend - foff);
1207 
1208 				/*
1209 				 * Determine whether the number of bytes that
1210 				 * must be zero'ed overflow to the next page.
1211 				 * If not, simply clear the exact bytes
1212 				 * (filesz to memsz) from this page.  Otherwise,
1213 				 * clear the remaining bytes of this page, and
1214 				 * map an following pages from /dev/zero.
1215 				 */
1216 				if (zlen < zplen)
1217 					zero((caddr_t)foff, (long)zlen);
1218 				else {
1219 					zero((caddr_t)foff, (long)zplen);
1220 
1221 					if ((zlen = (fend - (Off)zaddr)) > 0) {
1222 						if (dz_map(zaddr, zlen, mperm,
1223 						    MAP_FIXED | MAP_PRIVATE) ==
1224 						    MAP_FAILED)
1225 							return (0);
1226 					}
1227 				}
1228 			}
1229 		}
1230 
1231 		/*
1232 		 * Unmap anything from the last mapping address to this one and
1233 		 * update the mapping claim pointer.
1234 		 */
1235 		if ((fixed == 0) && ((size = addr - maddr) != 0)) {
1236 			(void) munmap(maddr, size);
1237 			rsize -= size;
1238 		}
1239 
1240 		/*
1241 		 * Retain this segments mapping information.
1242 		 */
1243 		mmaps[*mmapcnt].m_vaddr = addr;
1244 		mmaps[*mmapcnt].m_msize = mlen;
1245 		mmaps[*mmapcnt].m_fsize = flen;
1246 		mmaps[*mmapcnt].m_perm = mperm;
1247 		(*mmapcnt)++;
1248 
1249 		maddr = addr + M_PROUND(mlen);
1250 		rsize -= M_PROUND(mlen);
1251 	}
1252 
1253 	/*
1254 	 * If padding is required at the end of the image, obtain that now.
1255 	 * Note, if we've already obtained a reservation from anonymous memory
1256 	 * then this reservation will already include suitable padding.
1257 	 */
1258 	if (padsize) {
1259 		if (amret == AM_NOSUP) {
1260 			/*
1261 			 * maddr is currently page aligned from the last segment
1262 			 * mapping.
1263 			 */
1264 			if (dz_map(maddr, padsize, PROT_NONE, (MAP_PRIVATE |
1265 			    MAP_FIXED | MAP_NORESERVE)) == MAP_FAILED)
1266 				return (0);
1267 		}
1268 		maddr += padsize;
1269 		rsize -= padsize;
1270 	}
1271 
1272 	/*
1273 	 * Unmap any final reservation.
1274 	 */
1275 	if ((fixed == 0) && (rsize != 0))
1276 		(void) munmap(maddr, rsize);
1277 
1278 	return (faddr);
1279 }
1280 
1281 /*
1282  * A null symbol interpretor.  Used if a filter has no associated filtees.
1283  */
1284 /* ARGSUSED0 */
1285 static Sym *
1286 elf_null_find_sym(Slookup *slp, Rt_map **dlmp, uint_t *binfo)
1287 {
1288 	return ((Sym *)0);
1289 }
1290 
1291 /*
1292  * Disable filtee use.
1293  */
1294 static void
1295 elf_disable_filtee(Rt_map * lmp, Dyninfo * dip)
1296 {
1297 	dip->di_info = 0;
1298 
1299 	if ((dip->di_flags & FLG_DI_SYMFLTR) == 0) {
1300 		/*
1301 		 * If this is an object filter, free the filtee's duplication.
1302 		 */
1303 		if (OBJFLTRNDX(lmp) != FLTR_DISABLED) {
1304 			free(REFNAME(lmp));
1305 			REFNAME(lmp) = (char *)0;
1306 			OBJFLTRNDX(lmp) = FLTR_DISABLED;
1307 
1308 			/*
1309 			 * Indicate that this filtee is no longer available.
1310 			 */
1311 			if (dip->di_flags & FLG_DI_STDFLTR)
1312 				SYMINTP(lmp) = elf_null_find_sym;
1313 
1314 		}
1315 	} else if (dip->di_flags & FLG_DI_STDFLTR) {
1316 		/*
1317 		 * Indicate that this standard filtee is no longer available.
1318 		 */
1319 		if (SYMSFLTRCNT(lmp))
1320 			SYMSFLTRCNT(lmp)--;
1321 	} else {
1322 		/*
1323 		 * Indicate that this auxiliary filtee is no longer available.
1324 		 */
1325 		if (SYMAFLTRCNT(lmp))
1326 			SYMAFLTRCNT(lmp)--;
1327 	}
1328 	dip->di_flags &= ~MSK_DI_FILTER;
1329 }
1330 
1331 /*
1332  * Find symbol interpreter - filters.
1333  * This function is called when the symbols from a shared object should
1334  * be resolved from the shared objects filtees instead of from within itself.
1335  *
1336  * A symbol name of 0 is used to trigger filtee loading.
1337  */
1338 static Sym *
1339 _elf_lookup_filtee(Slookup *slp, Rt_map **dlmp, uint_t *binfo, uint_t ndx)
1340 {
1341 	const char	*name = slp->sl_name, *filtees;
1342 	Rt_map		*clmp = slp->sl_cmap;
1343 	Rt_map		*ilmp = slp->sl_imap;
1344 	Pnode		*pnp, **pnpp;
1345 	int		any;
1346 	Dyninfo		*dip = &DYNINFO(ilmp)[ndx];
1347 	Lm_list		*lml = LIST(ilmp);
1348 
1349 	/*
1350 	 * Indicate that the filter has been used.  If a binding already exists
1351 	 * to the caller, indicate that this object is referenced.  This insures
1352 	 * we don't generate false unreferenced diagnostics from ldd -u/U or
1353 	 * debugging.  Don't create a binding regardless, as this filter may
1354 	 * have been dlopen()'ed.
1355 	 */
1356 	if (name && (ilmp != clmp)) {
1357 		Word	tracing = (LIST(clmp)->lm_flags &
1358 		    (LML_FLG_TRC_UNREF | LML_FLG_TRC_UNUSED));
1359 
1360 		if (tracing || dbg_mask) {
1361 			Bnd_desc **	bdpp;
1362 			Aliste		off;
1363 
1364 			FLAGS1(ilmp) |= FL1_RT_USED;
1365 
1366 			if ((tracing & LML_FLG_TRC_UNREF) || dbg_mask) {
1367 				for (ALIST_TRAVERSE(CALLERS(ilmp), off, bdpp)) {
1368 					Bnd_desc *	bdp = *bdpp;
1369 
1370 					if (bdp->b_caller == clmp) {
1371 						bdp->b_flags |= BND_REFER;
1372 						break;
1373 					}
1374 				}
1375 			}
1376 		}
1377 	}
1378 
1379 	/*
1380 	 * If this is the first call to process this filter, establish the
1381 	 * filtee list.  If a configuration file exists, determine if any
1382 	 * filtee associations for this filter, and its filtee reference, are
1383 	 * defined.  Otherwise, process the filtee reference.  Any token
1384 	 * expansion is also completed at this point (i.e., $PLATFORM).
1385 	 */
1386 	filtees = (char *)STRTAB(ilmp) + DYN(ilmp)[ndx].d_un.d_val;
1387 	if (dip->di_info == 0) {
1388 		if (rtld_flags2 & RT_FL2_FLTCFG)
1389 			dip->di_info = elf_config_flt(PATHNAME(ilmp), filtees);
1390 
1391 		if (dip->di_info == 0) {
1392 			DBG_CALL(Dbg_file_filter(NAME(ilmp), filtees, 0));
1393 			if ((lml->lm_flags &
1394 			    (LML_FLG_TRC_VERBOSE | LML_FLG_TRC_SEARCH)) &&
1395 			    ((FLAGS1(ilmp) & FL1_RT_LDDSTUB) == 0))
1396 				(void) printf(MSG_INTL(MSG_LDD_FIL_FILTER),
1397 				    NAME(ilmp), filtees);
1398 
1399 			if ((dip->di_info = (void *)expand_paths(ilmp,
1400 			    filtees, PN_SER_FILTEE, 0)) == 0) {
1401 				elf_disable_filtee(ilmp, dip);
1402 				return ((Sym *)0);
1403 			}
1404 		}
1405 	}
1406 
1407 	/*
1408 	 * Traverse the filtee list, dlopen()'ing any objects specified and
1409 	 * using their group handle to lookup the symbol.
1410 	 */
1411 	for (any = 0, pnpp = (Pnode **)&(dip->di_info), pnp = *pnpp; pnp;
1412 	    pnpp = &pnp->p_next, pnp = * pnpp) {
1413 		int	mode;
1414 		Grp_hdl	*ghp;
1415 		Rt_map	*nlmp = 0;
1416 
1417 		if (pnp->p_len == 0)
1418 			continue;
1419 
1420 		/*
1421 		 * Establish the mode of the filtee from the filter.  As filtees
1422 		 * are loaded via a dlopen(), make sure that RTLD_GROUP is set
1423 		 * and the filtees aren't global.  It would be nice to have
1424 		 * RTLD_FIRST used here also, but as filters got out long before
1425 		 * RTLD_FIRST was introduced it's a little too late now.
1426 		 */
1427 		mode = MODE(ilmp) | RTLD_GROUP;
1428 		mode &= ~RTLD_GLOBAL;
1429 
1430 		/*
1431 		 * Insure that any auxiliary filter can locate symbols from its
1432 		 * caller.
1433 		 */
1434 		if (dip->di_flags & FLG_DI_AUXFLTR)
1435 			mode |= RTLD_PARENT;
1436 
1437 		/*
1438 		 * Process any hardware capability directory.  Establish a new
1439 		 * link-map control list from which to analyze any newly added
1440 		 * objects.
1441 		 */
1442 		if ((pnp->p_info == 0) && (pnp->p_orig & PN_TKN_HWCAP)) {
1443 			Lm_cntl	*lmc;
1444 			Aliste	lmco;
1445 
1446 			if (FLAGS(lml->lm_head) & FLG_RT_RELOCED) {
1447 				if ((lmc = alist_append(&(lml->lm_lists), 0,
1448 				    sizeof (Lm_cntl), AL_CNT_LMLISTS)) == 0)
1449 					return ((Sym *)0);
1450 				lmco = (Aliste)((char *)lmc -
1451 				    (char *)lml->lm_lists);
1452 			} else {
1453 				lmc = 0;
1454 				lmco = ALO_DATA;
1455 			}
1456 
1457 			pnp = hwcap_filtees(pnpp, lmco, dip, ilmp, filtees,
1458 			    mode, (FLG_RT_HANDLE | FLG_RT_HWCAP));
1459 
1460 			/*
1461 			 * Now that any hardware capability objects have been
1462 			 * processed, remove any link-map control list.
1463 			 */
1464 			if (lmc) {
1465 				if (pnp->p_len == 0)
1466 					(void) lm_salvage(lml, 0, lmco);
1467 				remove_cntl(lml, lmco);
1468 			}
1469 		}
1470 
1471 		if (pnp->p_len == 0)
1472 			continue;
1473 
1474 		/*
1475 		 * Process an individual filtee.
1476 		 */
1477 		if (pnp->p_info == 0) {
1478 			const char	*filtee = pnp->p_name;
1479 			int		audit = 0;
1480 
1481 			DBG_CALL(Dbg_file_filtee(NAME(ilmp), filtee, 0));
1482 
1483 			ghp = 0;
1484 
1485 			/*
1486 			 * Determine if the reference link map is already
1487 			 * loaded.  As an optimization compare the filtee with
1488 			 * our interpretor.  The most common filter is
1489 			 * libdl.so.1, which is a filter on ld.so.1.
1490 			 */
1491 #if	defined(_ELF64)
1492 			if (strcmp(filtee, MSG_ORIG(MSG_PTH_RTLD_64)) == 0) {
1493 #else
1494 			if (strcmp(filtee, MSG_ORIG(MSG_PTH_RTLD)) == 0) {
1495 #endif
1496 				/*
1497 				 * Create an association between ld.so.1 and
1498 				 * the filter.
1499 				 */
1500 				nlmp = lml_rtld.lm_head;
1501 				if ((ghp = hdl_create(&lml_rtld, nlmp, ilmp,
1502 				    (GPH_LDSO | GPH_FIRST | GPH_FILTEE))) == 0)
1503 					nlmp = 0;
1504 
1505 				/*
1506 				 * Establish the filter handle to prevent any
1507 				 * recursion.
1508 				 */
1509 				if (nlmp && ghp)
1510 					pnp->p_info = (void *)ghp;
1511 
1512 				/*
1513 				 * Audit the filter/filtee established.  Ignore
1514 				 * any return from the auditor, as we can't
1515 				 * allow ignore filtering to ld.so.1, otherwise
1516 				 * nothing is going to work.
1517 				 */
1518 				if ((lml->lm_tflags | FLAGS1(ilmp)) &
1519 				    LML_TFLG_AUD_OBJFILTER)
1520 					(void) audit_objfilter(ilmp, filtees,
1521 					    nlmp, 0);
1522 
1523 			} else {
1524 				Rej_desc	rej = { 0 };
1525 				Lm_cntl		*lmc;
1526 				Aliste		lmco;
1527 
1528 				/*
1529 				 * Establish a new link-map control list from
1530 				 * which to analyze any newly added objects.
1531 				 */
1532 				if (FLAGS(lml->lm_head) & FLG_RT_RELOCED) {
1533 					if ((lmc =
1534 					    alist_append(&(lml->lm_lists), 0,
1535 					    sizeof (Lm_cntl),
1536 					    AL_CNT_LMLISTS)) == 0)
1537 						return ((Sym *)0);
1538 					lmco = (Aliste)((char *)lmc -
1539 					    (char *)lml->lm_lists);
1540 				} else {
1541 					lmc = 0;
1542 					lmco = ALO_DATA;
1543 				}
1544 
1545 				/*
1546 				 * Load the filtee.
1547 				 */
1548 				if ((nlmp = load_path(lml, lmco, filtee, ilmp,
1549 				    mode, FLG_RT_HANDLE, &ghp, 0, &rej)) == 0) {
1550 					file_notfound(LIST(ilmp), filtee, ilmp,
1551 					    FLG_RT_HANDLE, &rej);
1552 					remove_rej(&rej);
1553 				}
1554 
1555 				/*
1556 				 * Establish the filter handle to prevent any
1557 				 * recursion.
1558 				 */
1559 				if (nlmp && ghp) {
1560 					ghp->gh_flags |= GPH_FILTEE;
1561 					pnp->p_info = (void *)ghp;
1562 				}
1563 
1564 				/*
1565 				 * Audit the filter/filtee established.  A
1566 				 * return of 0 indicates the auditor wishes to
1567 				 * ignore this filtee.
1568 				 */
1569 				if (nlmp && ((lml->lm_tflags | FLAGS1(ilmp)) &
1570 				    LML_TFLG_AUD_OBJFILTER)) {
1571 					if (audit_objfilter(ilmp, filtees,
1572 					    nlmp, 0) == 0) {
1573 						audit = 1;
1574 						nlmp = 0;
1575 					}
1576 				}
1577 
1578 				/*
1579 				 * Finish processing the objects associated with
1580 				 * this request.  Create an association between
1581 				 * this object and the originating filter to
1582 				 * provide sufficient information to tear down
1583 				 * this filtee if necessary.
1584 				 */
1585 				if (nlmp && ghp &&
1586 				    ((analyze_lmc(lml, lmco, nlmp) == 0) ||
1587 				    (relocate_lmc(lml, lmco, nlmp) == 0)))
1588 					nlmp = 0;
1589 
1590 				/*
1591 				 * If the filtee has been successfully
1592 				 * processed, and it is part of a link-map
1593 				 * control list that is equivalent, or less,
1594 				 * than the filter control list, create an
1595 				 * association between the filter and filtee.
1596 				 * This association provides sufficient
1597 				 * information to tear down the filter and
1598 				 * filtee if necessary.
1599 				 */
1600 				if (nlmp && ghp && (CNTL(nlmp) <= CNTL(ilmp)) &&
1601 				    (hdl_add(ghp, ilmp, GPD_FILTER) == 0))
1602 					nlmp = 0;
1603 
1604 				/*
1605 				 * Now that this object has been processed,
1606 				 * remove any link-map control list.
1607 				 */
1608 				if (lmc) {
1609 					if (nlmp == 0)
1610 						(void) lm_salvage(lml, 0, lmco);
1611 					remove_cntl(lml, lmco);
1612 				}
1613 			}
1614 
1615 			/*
1616 			 * Generate a diagnostic if the filtee couldn't be
1617 			 * loaded, null out the pnode entry, and continue
1618 			 * the search.  Otherwise, retain this group handle
1619 			 * for future symbol searches.
1620 			 */
1621 			if (nlmp == 0) {
1622 				pnp->p_info = 0;
1623 				DBG_CALL(Dbg_file_filtee(0, filtee, audit));
1624 
1625 				if (ghp)
1626 					(void) dlclose_core(ghp, ilmp);
1627 
1628 				pnp->p_len = 0;
1629 				continue;
1630 			}
1631 		}
1632 
1633 		ghp = (Grp_hdl *)pnp->p_info;
1634 
1635 		/*
1636 		 * If we're just here to trigger filtee loading skip the symbol
1637 		 * lookup so we'll continue looking for additional filtees.
1638 		 */
1639 		if (name) {
1640 			Grp_desc	*gdp;
1641 			Sym		*sym = 0;
1642 			Aliste		off;
1643 			Slookup		sl = *slp;
1644 
1645 			sl.sl_flags |= LKUP_FIRST;
1646 			any++;
1647 
1648 			/*
1649 			 * Look for the symbol in the handles dependencies.
1650 			 */
1651 			for (ALIST_TRAVERSE(ghp->gh_depends, off, gdp)) {
1652 				if ((gdp->gd_flags & GPD_AVAIL) == 0)
1653 					continue;
1654 
1655 				/*
1656 				 * If our parent is a dependency don't look at
1657 				 * it (otherwise we are in a recursive loop).
1658 				 * This situation can occur with auxiliary
1659 				 * filters if the filtee has a dependency on the
1660 				 * filter.  This dependency isn't necessary as
1661 				 * auxiliary filters are opened RTLD_PARENT, but
1662 				 * users may still unknowingly add an explicit
1663 				 * dependency to the parent.
1664 				 */
1665 				if ((sl.sl_imap = gdp->gd_depend) == ilmp)
1666 					continue;
1667 
1668 				if (((sym = SYMINTP(sl.sl_imap)(&sl, dlmp,
1669 				    binfo)) != 0) ||
1670 				    (ghp->gh_flags & GPH_FIRST))
1671 					break;
1672 			}
1673 
1674 			/*
1675 			 * If this filtee has just been loaded (nlmp != 0),
1676 			 * determine whether the filtee was triggered by a
1677 			 * relocation from an object that is still being
1678 			 * relocated on a leaf link-map control list.  As the
1679 			 * relocation of an object on this list might still
1680 			 * fail, we can't yet bind the filter to the filtee.
1681 			 * To do so, would be locking the filtee so that it
1682 			 * couldn't be deleted, and the filtee itself could have
1683 			 * bound to an object that must be torn down.  Insure
1684 			 * the caller isn't bound to the handle at this time.
1685 			 * Any association will be reestablished when the filter
1686 			 * is later referenced and the filtee has propagated to
1687 			 * the same link-map control list.
1688 			 */
1689 			if (nlmp && (CNTL(nlmp) > CNTL(ilmp))) {
1690 				remove_caller(ghp, ilmp);
1691 				pnp->p_info = 0;
1692 			}
1693 			if (sym) {
1694 				*binfo |= DBG_BINFO_FILTEE;
1695 				return (sym);
1696 			}
1697 		}
1698 
1699 		/*
1700 		 * If this object is tagged to terminate filtee processing we're
1701 		 * done.
1702 		 */
1703 		if (FLAGS1(ghp->gh_owner) & FL1_RT_ENDFILTE)
1704 			break;
1705 	}
1706 
1707 	/*
1708 	 * If we're just here to trigger filtee loading then we're done.
1709 	 */
1710 	if (name == 0)
1711 		return ((Sym *)0);
1712 
1713 	/*
1714 	 * If no filtees have been found for a filter, clean up any Pnode
1715 	 * structures and disable their search completely.  For auxiliary
1716 	 * filters we can reselect the symbol search function so that we never
1717 	 * enter this routine again for this object.  For standard filters we
1718 	 * use the null symbol routine.
1719 	 */
1720 	if (any == 0) {
1721 		remove_pnode((Pnode *)dip->di_info);
1722 		elf_disable_filtee(ilmp, dip);
1723 		return ((Sym *)0);
1724 	}
1725 
1726 	return ((Sym *)0);
1727 }
1728 
1729 /*
1730  * Focal point for disabling error messages for auxiliary filters.  As an
1731  * auxiliary filter allows for filtee use, but provides a fallback should a
1732  * filtee not exist (or fail to load), any errors generated as a consequence of
1733  * trying to load the filtees are typically suppressed.  Setting RT_FL_SILENCERR
1734  * suppresses errors generated by eprint(), but insures a debug diagnostic is
1735  * produced.  ldd(1) employs printf(), and here, the selection of whether to
1736  * print a diagnostic in regards to auxiliary filters is a little more complex.
1737  *
1738  *   .	The determination of whether to produce an ldd message, or a fatal
1739  *	error message is driven by LML_FLG_TRC_ENABLE.
1740  *   .	More detailed ldd messages may also be driven off of LML_FLG_TRC_WARN,
1741  *	(ldd -d/-r), LML_FLG_TRC_VERBOSE (ldd -v), LML_FLG_TRC_SEARCH (ldd -s),
1742  *	and LML_FLG_TRC_UNREF/LML_FLG_TRC_UNUSED (ldd -U/-u).
1743  *
1744  *   .	If the calling object is lddstub, then several classes of message are
1745  *	suppressed.  The user isn't trying to diagnose lddstub, this is simply
1746  *	a stub executable employed to preload a user specified library against.
1747  *
1748  *   .	If RT_FL_SILENCERR is in effect then any generic ldd() messages should
1749  *	be suppressed.  All detailed ldd messages should still be produced.
1750  */
1751 Sym *
1752 elf_lookup_filtee(Slookup *slp, Rt_map **dlmp, uint_t *binfo, uint_t ndx)
1753 {
1754 	Sym	*sym;
1755 	Dyninfo	*dip = &DYNINFO(slp->sl_imap)[ndx];
1756 	int	silent = 0;
1757 
1758 	/*
1759 	 * Make sure this entry is still acting as a filter.  We may have tried
1760 	 * to process this previously, and disabled it if the filtee couldn't
1761 	 * be processed.  However, other entries may provide different filtees
1762 	 * that are yet to be completed.
1763 	 */
1764 	if (dip->di_flags == 0)
1765 		return ((Sym *)0);
1766 
1767 	/*
1768 	 * Indicate whether an error message is required should this filtee not
1769 	 * be found, based on the type of filter.
1770 	 */
1771 	if ((dip->di_flags & FLG_DI_AUXFLTR) &&
1772 	    ((rtld_flags & (RT_FL_WARNFLTR | RT_FL_SILENCERR)) == 0)) {
1773 		rtld_flags |= RT_FL_SILENCERR;
1774 		silent = 1;
1775 	}
1776 
1777 	sym = _elf_lookup_filtee(slp, dlmp, binfo, ndx);
1778 
1779 	if (silent)
1780 		rtld_flags &= ~RT_FL_SILENCERR;
1781 
1782 	return (sym);
1783 }
1784 
1785 /*
1786  * Compute the elf hash value (as defined in the ELF access library).
1787  * The form of the hash table is:
1788  *
1789  *	|--------------|
1790  *	| # of buckets |
1791  *	|--------------|
1792  *	| # of chains  |
1793  *	|--------------|
1794  *	|   bucket[]   |
1795  *	|--------------|
1796  *	|   chain[]    |
1797  *	|--------------|
1798  */
1799 ulong_t
1800 elf_hash(const char *name)
1801 {
1802 	uint_t	hval = 0;
1803 
1804 	while (*name) {
1805 		uint_t	g;
1806 		hval = (hval << 4) + *name++;
1807 		if ((g = (hval & 0xf0000000)) != 0)
1808 			hval ^= g >> 24;
1809 		hval &= ~g;
1810 	}
1811 	return ((ulong_t)hval);
1812 }
1813 
1814 /*
1815  * If flag argument has LKUP_SPEC set, we treat undefined symbols of type
1816  * function specially in the executable - if they have a value, even though
1817  * undefined, we use that value.  This allows us to associate all references
1818  * to a function's address to a single place in the process: the plt entry
1819  * for that function in the executable.  Calls to lookup from plt binding
1820  * routines do NOT set LKUP_SPEC in the flag.
1821  */
1822 Sym *
1823 elf_find_sym(Slookup *slp, Rt_map **dlmp, uint_t *binfo)
1824 {
1825 	const char	*name = slp->sl_name;
1826 	Rt_map		*ilmp = slp->sl_imap;
1827 	ulong_t		hash = slp->sl_hash;
1828 	uint_t		ndx, htmp, buckets, *chainptr;
1829 	Sym		*sym, *symtabptr;
1830 	char		*strtabptr, *strtabname;
1831 	uint_t		flags1;
1832 	Syminfo		*sip;
1833 
1834 	/*
1835 	 * If we're only here to establish a symbols index, skip the diagnostic
1836 	 * used to trace a symbol search.
1837 	 */
1838 	if ((slp->sl_flags & LKUP_SYMNDX) == 0) {
1839 		DBG_CALL(Dbg_syms_lookup(name, NAME(ilmp),
1840 		    MSG_ORIG(MSG_STR_ELF)));
1841 	}
1842 
1843 	if (HASH(ilmp) == 0)
1844 		return ((Sym *)0);
1845 
1846 	buckets = HASH(ilmp)[0];
1847 	/* LINTED */
1848 	htmp = (uint_t)hash % buckets;
1849 
1850 	/*
1851 	 * Get the first symbol on hash chain and initialize the string
1852 	 * and symbol table pointers.
1853 	 */
1854 	if ((ndx = HASH(ilmp)[htmp + 2]) == 0)
1855 		return ((Sym *)0);
1856 
1857 	chainptr = HASH(ilmp) + 2 + buckets;
1858 	strtabptr = STRTAB(ilmp);
1859 	symtabptr = SYMTAB(ilmp);
1860 
1861 	while (ndx) {
1862 		sym = symtabptr + ndx;
1863 		strtabname = strtabptr + sym->st_name;
1864 
1865 		/*
1866 		 * Compare the symbol found with the name required.  If the
1867 		 * names don't match continue with the next hash entry.
1868 		 */
1869 		if ((*strtabname++ != *name) || strcmp(strtabname, &name[1])) {
1870 			if ((ndx = chainptr[ndx]) != 0)
1871 				continue;
1872 			return ((Sym *)0);
1873 		}
1874 
1875 		/*
1876 		 * If we're only here to establish a symbols index, we're done.
1877 		 */
1878 		if (slp->sl_flags & LKUP_SYMNDX)
1879 			return (sym);
1880 
1881 		/*
1882 		 * If we find a match and the symbol is defined, return the
1883 		 * symbol pointer and the link map in which it was found.
1884 		 */
1885 		if (sym->st_shndx != SHN_UNDEF) {
1886 			*dlmp = ilmp;
1887 			*binfo |= DBG_BINFO_FOUND;
1888 			if (FLAGS(ilmp) & FLG_RT_INTRPOSE)
1889 				*binfo |= DBG_BINFO_INTERPOSE;
1890 			break;
1891 
1892 		/*
1893 		 * If we find a match and the symbol is undefined, the
1894 		 * symbol type is a function, and the value of the symbol
1895 		 * is non zero, then this is a special case.  This allows
1896 		 * the resolution of a function address to the plt[] entry.
1897 		 * See SPARC ABI, Dynamic Linking, Function Addresses for
1898 		 * more details.
1899 		 */
1900 		} else if ((slp->sl_flags & LKUP_SPEC) &&
1901 		    (FLAGS(ilmp) & FLG_RT_ISMAIN) && (sym->st_value != 0) &&
1902 		    (ELF_ST_TYPE(sym->st_info) == STT_FUNC)) {
1903 			*dlmp = ilmp;
1904 			*binfo |= (DBG_BINFO_FOUND | DBG_BINFO_PLTADDR);
1905 			if (FLAGS(ilmp) & FLG_RT_INTRPOSE)
1906 				*binfo |= DBG_BINFO_INTERPOSE;
1907 			return (sym);
1908 		}
1909 
1910 		/*
1911 		 * Undefined symbol.
1912 		 */
1913 		return ((Sym *)0);
1914 	}
1915 
1916 	/*
1917 	 * We've found a match.  Determine if the defining object contains
1918 	 * symbol binding information.
1919 	 */
1920 	if ((sip = SYMINFO(ilmp)) != 0)
1921 		/* LINTED */
1922 		sip = (Syminfo *)((char *)sip + (ndx * SYMINENT(ilmp)));
1923 
1924 	/*
1925 	 * If this is a direct binding request, but the symbol definition has
1926 	 * disabled directly binding to it (presumably because the symbol
1927 	 * definition has been changed since the referring object was built),
1928 	 * indicate this failure so that the caller can fall back to a standard
1929 	 * symbol search.  Clear any debug binding information for cleanliness.
1930 	 */
1931 	if (sip && (slp->sl_flags & LKUP_DIRECT) &&
1932 	    (sip->si_flags & SYMINFO_FLG_NOEXTDIRECT)) {
1933 		*binfo |= BINFO_DIRECTDIS;
1934 		*binfo &= ~DBG_BINFO_MSK;
1935 		return ((Sym *)0);
1936 	}
1937 
1938 	/*
1939 	 * Determine whether this object is acting as a filter.
1940 	 */
1941 	if (((flags1 = FLAGS1(ilmp)) & MSK_RT_FILTER) == 0)
1942 		return (sym);
1943 
1944 	/*
1945 	 * Determine if this object offers per-symbol filtering, and if so,
1946 	 * whether this symbol references a filtee.
1947 	 */
1948 	if (sip && (flags1 & (FL1_RT_SYMSFLTR | FL1_RT_SYMAFLTR))) {
1949 		/*
1950 		 * If this is a standard filter reference, and no standard
1951 		 * filtees remain to be inspected, we're done.  If this is an
1952 		 * auxiliary filter reference, and no auxiliary filtees remain,
1953 		 * we'll fall through in case any object filtering is available.
1954 		 */
1955 		if ((sip->si_flags & SYMINFO_FLG_FILTER) &&
1956 		    (SYMSFLTRCNT(ilmp) == 0))
1957 			return ((Sym *)0);
1958 
1959 		if ((sip->si_flags & SYMINFO_FLG_FILTER) ||
1960 		    ((sip->si_flags & SYMINFO_FLG_AUXILIARY) &&
1961 		    SYMAFLTRCNT(ilmp))) {
1962 			Sym *	fsym;
1963 
1964 			/*
1965 			 * This symbol has an associated filtee.  Lookup the
1966 			 * symbol in the filtee, and if it is found return it.
1967 			 * If the symbol doesn't exist, and this is a standard
1968 			 * filter, return an error, otherwise fall through to
1969 			 * catch any object filtering that may be available.
1970 			 */
1971 			if ((fsym = elf_lookup_filtee(slp, dlmp, binfo,
1972 			    sip->si_boundto)) != 0)
1973 				return (fsym);
1974 			if (sip->si_flags & SYMINFO_FLG_FILTER)
1975 				return ((Sym *)0);
1976 		}
1977 	}
1978 
1979 	/*
1980 	 * Determine if this object provides global filtering.
1981 	 */
1982 	if (flags1 & (FL1_RT_OBJSFLTR | FL1_RT_OBJAFLTR)) {
1983 		Sym *	fsym;
1984 
1985 		if (OBJFLTRNDX(ilmp) != FLTR_DISABLED) {
1986 			/*
1987 			 * This object has an associated filtee.  Lookup the
1988 			 * symbol in the filtee, and if it is found return it.
1989 			 * If the symbol doesn't exist, and this is a standard
1990 			 * filter, return and error, otherwise return the symbol
1991 			 * within the filter itself.
1992 			 */
1993 			if ((fsym = elf_lookup_filtee(slp, dlmp, binfo,
1994 			    OBJFLTRNDX(ilmp))) != 0)
1995 				return (fsym);
1996 		}
1997 
1998 		if (flags1 & FL1_RT_OBJSFLTR)
1999 			return ((Sym *)0);
2000 	}
2001 	return (sym);
2002 }
2003 
2004 /*
2005  * Create a new Rt_map structure for an ELF object and initialize
2006  * all values.
2007  */
2008 Rt_map *
2009 elf_new_lm(Lm_list *lml, const char *pname, const char *oname, Dyn *ld,
2010     ulong_t addr, ulong_t etext, Aliste lmco, ulong_t msize, ulong_t entry,
2011     ulong_t paddr, ulong_t padimsize, Mmap *mmaps, uint_t mmapcnt)
2012 {
2013 	Rt_map		*lmp;
2014 	ulong_t		base, fltr = 0, audit = 0, cfile = 0, crle = 0;
2015 	Xword		rpath = 0;
2016 	Ehdr		*ehdr = (Ehdr *)addr;
2017 
2018 	DBG_CALL(Dbg_file_elf(pname, (ulong_t)ld, addr, msize, entry,
2019 	    get_linkmap_id(lml), lmco));
2020 
2021 	/*
2022 	 * Allocate space for the link-map and private elf information.  Once
2023 	 * these are allocated and initialized, we can use remove_so(0, lmp) to
2024 	 * tear down the link-map should any failures occur.
2025 	 */
2026 	if ((lmp = calloc(sizeof (Rt_map), 1)) == 0)
2027 		return (0);
2028 	if ((ELFPRV(lmp) = calloc(sizeof (Rt_elfp), 1)) == 0) {
2029 		free(lmp);
2030 		return (0);
2031 	}
2032 
2033 	/*
2034 	 * All fields not filled in were set to 0 by calloc.
2035 	 */
2036 	ORIGNAME(lmp) = PATHNAME(lmp) = NAME(lmp) = (char *)pname;
2037 	DYN(lmp) = ld;
2038 	ADDR(lmp) = addr;
2039 	MSIZE(lmp) = msize;
2040 	ENTRY(lmp) = (Addr)entry;
2041 	SYMINTP(lmp) = elf_find_sym;
2042 	ETEXT(lmp) = etext;
2043 	FCT(lmp) = &elf_fct;
2044 	LIST(lmp) = lml;
2045 	PADSTART(lmp) = paddr;
2046 	PADIMLEN(lmp) = padimsize;
2047 	THREADID(lmp) = rt_thr_self();
2048 	OBJFLTRNDX(lmp) = FLTR_DISABLED;
2049 	SORTVAL(lmp) = -1;
2050 
2051 	MMAPS(lmp) = mmaps;
2052 	MMAPCNT(lmp) = mmapcnt;
2053 	ASSERT(mmapcnt != 0);
2054 
2055 	/*
2056 	 * If this is a shared object, add the base address to each address.
2057 	 * if this is an executable, use address as is.
2058 	 */
2059 	if (ehdr->e_type == ET_EXEC) {
2060 		base = 0;
2061 		FLAGS(lmp) |= FLG_RT_FIXED;
2062 	} else
2063 		base = addr;
2064 
2065 	/*
2066 	 * Fill in rest of the link map entries with information from the file's
2067 	 * dynamic structure.
2068 	 */
2069 	if (ld) {
2070 		uint_t	dyncnt = 0;
2071 		Xword	pltpadsz = 0;
2072 		void	*rtldinfo;
2073 
2074 		/* CSTYLED */
2075 		for ( ; ld->d_tag != DT_NULL; ++ld, dyncnt++) {
2076 			switch ((Xword)ld->d_tag) {
2077 			case DT_SYMTAB:
2078 				SYMTAB(lmp) = (void *)(ld->d_un.d_ptr + base);
2079 				break;
2080 			case DT_STRTAB:
2081 				STRTAB(lmp) = (void *)(ld->d_un.d_ptr + base);
2082 				break;
2083 			case DT_SYMENT:
2084 				SYMENT(lmp) = ld->d_un.d_val;
2085 				break;
2086 			case DT_FEATURE_1:
2087 				ld->d_un.d_val |= DTF_1_PARINIT;
2088 				if (ld->d_un.d_val & DTF_1_CONFEXP)
2089 					crle = 1;
2090 				break;
2091 			case DT_MOVESZ:
2092 				MOVESZ(lmp) = ld->d_un.d_val;
2093 				FLAGS(lmp) |= FLG_RT_MOVE;
2094 				break;
2095 			case DT_MOVEENT:
2096 				MOVEENT(lmp) = ld->d_un.d_val;
2097 				break;
2098 			case DT_MOVETAB:
2099 				MOVETAB(lmp) = (void *)(ld->d_un.d_ptr + base);
2100 				break;
2101 			case DT_REL:
2102 			case DT_RELA:
2103 				/*
2104 				 * At this time we can only handle 1 type of
2105 				 * relocation per object.
2106 				 */
2107 				REL(lmp) = (void *)(ld->d_un.d_ptr + base);
2108 				break;
2109 			case DT_RELSZ:
2110 			case DT_RELASZ:
2111 				RELSZ(lmp) = ld->d_un.d_val;
2112 				break;
2113 			case DT_RELENT:
2114 			case DT_RELAENT:
2115 				RELENT(lmp) = ld->d_un.d_val;
2116 				break;
2117 			case DT_RELCOUNT:
2118 			case DT_RELACOUNT:
2119 				RELACOUNT(lmp) = (uint_t)ld->d_un.d_val;
2120 				break;
2121 			case DT_TEXTREL:
2122 				FLAGS1(lmp) |= FL1_RT_TEXTREL;
2123 				break;
2124 			case DT_HASH:
2125 				HASH(lmp) = (uint_t *)(ld->d_un.d_ptr + base);
2126 				break;
2127 			case DT_PLTGOT:
2128 				PLTGOT(lmp) = (uint_t *)(ld->d_un.d_ptr + base);
2129 				break;
2130 			case DT_PLTRELSZ:
2131 				PLTRELSZ(lmp) = ld->d_un.d_val;
2132 				break;
2133 			case DT_JMPREL:
2134 				JMPREL(lmp) = (void *)(ld->d_un.d_ptr + base);
2135 				break;
2136 			case DT_INIT:
2137 				INIT(lmp) = (void (*)())(ld->d_un.d_ptr + base);
2138 				break;
2139 			case DT_FINI:
2140 				FINI(lmp) = (void (*)())(ld->d_un.d_ptr + base);
2141 				break;
2142 			case DT_INIT_ARRAY:
2143 				INITARRAY(lmp) = (Addr *)(ld->d_un.d_ptr +
2144 				    base);
2145 				break;
2146 			case DT_INIT_ARRAYSZ:
2147 				INITARRAYSZ(lmp) = (uint_t)ld->d_un.d_val;
2148 				break;
2149 			case DT_FINI_ARRAY:
2150 				FINIARRAY(lmp) = (Addr *)(ld->d_un.d_ptr +
2151 				    base);
2152 				break;
2153 			case DT_FINI_ARRAYSZ:
2154 				FINIARRAYSZ(lmp) = (uint_t)ld->d_un.d_val;
2155 				break;
2156 			case DT_PREINIT_ARRAY:
2157 				PREINITARRAY(lmp) = (Addr *)(ld->d_un.d_ptr +
2158 				    base);
2159 				break;
2160 			case DT_PREINIT_ARRAYSZ:
2161 				PREINITARRAYSZ(lmp) = (uint_t)ld->d_un.d_val;
2162 				break;
2163 			case DT_RPATH:
2164 			case DT_RUNPATH:
2165 				rpath = ld->d_un.d_val;
2166 				break;
2167 			case DT_FILTER:
2168 				fltr = ld->d_un.d_val;
2169 				OBJFLTRNDX(lmp) = dyncnt;
2170 				FLAGS1(lmp) |= FL1_RT_OBJSFLTR;
2171 				break;
2172 			case DT_AUXILIARY:
2173 				if (!(rtld_flags & RT_FL_NOAUXFLTR)) {
2174 					fltr = ld->d_un.d_val;
2175 					OBJFLTRNDX(lmp) = dyncnt;
2176 				}
2177 				FLAGS1(lmp) |= FL1_RT_OBJAFLTR;
2178 				break;
2179 			case DT_SUNW_FILTER:
2180 				SYMSFLTRCNT(lmp)++;
2181 				FLAGS1(lmp) |= FL1_RT_SYMSFLTR;
2182 				break;
2183 			case DT_SUNW_AUXILIARY:
2184 				if (!(rtld_flags & RT_FL_NOAUXFLTR)) {
2185 					SYMAFLTRCNT(lmp)++;
2186 				}
2187 				FLAGS1(lmp) |= FL1_RT_SYMAFLTR;
2188 				break;
2189 			case DT_DEPAUDIT:
2190 				if (!(rtld_flags & RT_FL_NOAUDIT))
2191 					audit = ld->d_un.d_val;
2192 				break;
2193 			case DT_CONFIG:
2194 				cfile = ld->d_un.d_val;
2195 				break;
2196 			case DT_DEBUG:
2197 				/*
2198 				 * DT_DEBUG entries are only created in
2199 				 * dynamic objects that require an interpretor
2200 				 * (ie. all dynamic executables and some shared
2201 				 * objects), and provide for a hand-shake with
2202 				 * debuggers.  This entry is initialized to
2203 				 * zero by the link-editor.  If a debugger has
2204 				 * us and updated this entry set the debugger
2205 				 * flag, and finish initializing the debugging
2206 				 * structure (see setup() also).  Switch off any
2207 				 * configuration object use as most debuggers
2208 				 * can't handle fixed dynamic executables as
2209 				 * dependencies, and we can't handle requests
2210 				 * like object padding for alternative objects.
2211 				 */
2212 				if (ld->d_un.d_ptr)
2213 					rtld_flags |=
2214 					    (RT_FL_DEBUGGER | RT_FL_NOOBJALT);
2215 				ld->d_un.d_ptr = (Addr)&r_debug;
2216 				break;
2217 			case DT_VERNEED:
2218 				VERNEED(lmp) = (Verneed *)(ld->d_un.d_ptr +
2219 				    base);
2220 				break;
2221 			case DT_VERNEEDNUM:
2222 				/* LINTED */
2223 				VERNEEDNUM(lmp) = (int)ld->d_un.d_val;
2224 				break;
2225 			case DT_VERDEF:
2226 				VERDEF(lmp) = (Verdef *)(ld->d_un.d_ptr + base);
2227 				break;
2228 			case DT_VERDEFNUM:
2229 				/* LINTED */
2230 				VERDEFNUM(lmp) = (int)ld->d_un.d_val;
2231 				break;
2232 			case DT_BIND_NOW:
2233 				if ((ld->d_un.d_val & DF_BIND_NOW) &&
2234 				    ((rtld_flags2 & RT_FL2_BINDLAZY) == 0)) {
2235 					MODE(lmp) |= RTLD_NOW;
2236 					MODE(lmp) &= ~RTLD_LAZY;
2237 				}
2238 				break;
2239 			case DT_FLAGS:
2240 				if (ld->d_un.d_val & DF_SYMBOLIC)
2241 					FLAGS1(lmp) |= FL1_RT_SYMBOLIC;
2242 				if (ld->d_un.d_val & DF_TEXTREL)
2243 					FLAGS1(lmp) |= FL1_RT_TEXTREL;
2244 				if ((ld->d_un.d_val & DF_BIND_NOW) &&
2245 				    ((rtld_flags2 & RT_FL2_BINDLAZY) == 0)) {
2246 					MODE(lmp) |= RTLD_NOW;
2247 					MODE(lmp) &= ~RTLD_LAZY;
2248 				}
2249 				break;
2250 			case DT_FLAGS_1:
2251 				if (ld->d_un.d_val & DF_1_DISPRELPND)
2252 					FLAGS1(lmp) |= FL1_RT_DISPREL;
2253 				if (ld->d_un.d_val & DF_1_GROUP)
2254 					FLAGS(lmp) |=
2255 					    (FLG_RT_SETGROUP | FLG_RT_HANDLE);
2256 				if ((ld->d_un.d_val & DF_1_NOW) &&
2257 				    ((rtld_flags2 & RT_FL2_BINDLAZY) == 0)) {
2258 					MODE(lmp) |= RTLD_NOW;
2259 					MODE(lmp) &= ~RTLD_LAZY;
2260 				}
2261 				if (ld->d_un.d_val & DF_1_NODELETE)
2262 					MODE(lmp) |= RTLD_NODELETE;
2263 				if (ld->d_un.d_val & DF_1_INITFIRST)
2264 					FLAGS(lmp) |= FLG_RT_INITFRST;
2265 				if (ld->d_un.d_val & DF_1_NOOPEN)
2266 					FLAGS(lmp) |= FLG_RT_NOOPEN;
2267 				if (ld->d_un.d_val & DF_1_LOADFLTR)
2268 					FLAGS(lmp) |= FLG_RT_LOADFLTR;
2269 				if (ld->d_un.d_val & DF_1_NODUMP)
2270 					FLAGS(lmp) |= FLG_RT_NODUMP;
2271 				if (ld->d_un.d_val & DF_1_CONFALT)
2272 					crle = 1;
2273 				if (ld->d_un.d_val & DF_1_DIRECT)
2274 					FLAGS(lmp) |= FLG_RT_DIRECT;
2275 				if (ld->d_un.d_val & DF_1_NODEFLIB)
2276 					FLAGS1(lmp) |= FL1_RT_NODEFLIB;
2277 				if (ld->d_un.d_val & DF_1_ENDFILTEE)
2278 					FLAGS1(lmp) |= FL1_RT_ENDFILTE;
2279 				if (ld->d_un.d_val & DF_1_TRANS)
2280 					FLAGS(lmp) |= FLG_RT_TRANS;
2281 #ifndef	EXPAND_RELATIVE
2282 				if (ld->d_un.d_val & DF_1_ORIGIN)
2283 					FLAGS1(lmp) |= FL1_RT_RELATIVE;
2284 #endif
2285 				/*
2286 				 * If this object identifies itself as an
2287 				 * interposer, but relocation processing has
2288 				 * already started, then demote it.  It's too
2289 				 * late to guarantee complete interposition.
2290 				 */
2291 				if (ld->d_un.d_val & DF_1_INTERPOSE) {
2292 				    if ((lml->lm_flags & LML_FLG_STARTREL) == 0)
2293 					FLAGS(lmp) |= FLG_RT_INTRPOSE;
2294 				    else {
2295 					DBG_CALL(Dbg_util_intoolate(NAME(lmp)));
2296 					if (lml->lm_flags & LML_FLG_TRC_ENABLE)
2297 					    (void) printf(
2298 						MSG_INTL(MSG_LDD_REL_ERR2),
2299 						NAME(lmp));
2300 				    }
2301 				}
2302 				break;
2303 			case DT_SYMINFO:
2304 				SYMINFO(lmp) = (Syminfo *)(ld->d_un.d_ptr +
2305 				    base);
2306 				break;
2307 			case DT_SYMINENT:
2308 				SYMINENT(lmp) = ld->d_un.d_val;
2309 				break;
2310 			case DT_PLTPAD:
2311 				PLTPAD(lmp) = (void *)(ld->d_un.d_ptr + base);
2312 				break;
2313 			case DT_PLTPADSZ:
2314 				pltpadsz = ld->d_un.d_val;
2315 				break;
2316 			case DT_SUNW_RTLDINF:
2317 				if ((lml->lm_info_lmp != 0) &&
2318 				    (lml->lm_info_lmp != lmp)) {
2319 					DBG_CALL(Dbg_unused_rtldinfo(
2320 						NAME(lmp),
2321 						NAME(lml->lm_info_lmp)));
2322 					break;
2323 				}
2324 				lml->lm_info_lmp = lmp;
2325 				rtldinfo = (void *)(ld->d_un.d_ptr + base);
2326 
2327 				/*
2328 				 * We maintain a list of DT_SUNW_RTLDINFO
2329 				 * structures for a given object.  This permits
2330 				 * the RTLDINFO structures to be grouped
2331 				 * functionly inside of a shared object.
2332 				 *
2333 				 * For example, we could have one for
2334 				 * thread_init, and another for atexit
2335 				 * reservations.
2336 				 */
2337 				if (alist_append(&lml->lm_rtldinfo, &rtldinfo,
2338 				    sizeof (void *), AL_CNT_RTLDINFO) == 0) {
2339 					remove_so(0, lmp);
2340 					return (0);
2341 				}
2342 				break;
2343 			case DT_DEPRECATED_SPARC_REGISTER:
2344 			case M_DT_REGISTER:
2345 				FLAGS(lmp) |= FLG_RT_REGSYMS;
2346 				break;
2347 			case M_DT_PLTRESERVE:
2348 				PLTRESERVE(lmp) = (void *)(ld->d_un.d_ptr +
2349 				    base);
2350 				break;
2351 			}
2352 		}
2353 
2354 
2355 		if (PLTPAD(lmp)) {
2356 			if (pltpadsz == (Xword)0)
2357 				PLTPAD(lmp) = 0;
2358 			else
2359 				PLTPADEND(lmp) = (void *)((Addr)PLTPAD(lmp) +
2360 				    pltpadsz);
2361 		}
2362 
2363 		/*
2364 		 * Allocate Dynamic Info structure
2365 		 */
2366 		if ((DYNINFO(lmp) = calloc((size_t)dyncnt,
2367 		    sizeof (Dyninfo))) == 0) {
2368 			remove_so(0, lmp);
2369 			return (0);
2370 		}
2371 		DYNINFOCNT(lmp) = dyncnt;
2372 	}
2373 
2374 	/*
2375 	 * If configuration file use hasn't been disabled, and a configuration
2376 	 * file hasn't already been set via an environment variable, see if any
2377 	 * application specific configuration file is specified.  An LD_CONFIG
2378 	 * setting is used first, but if this image was generated via crle(1)
2379 	 * then a default configuration file is a fall-back.
2380 	 */
2381 	if ((!(rtld_flags & RT_FL_NOCFG)) && (config->c_name == 0)) {
2382 		if (cfile)
2383 			config->c_name = (const char *)(cfile +
2384 			    (char *)STRTAB(lmp));
2385 		else if (crle) {
2386 			rtld_flags |= RT_FL_CONFAPP;
2387 #ifndef	EXPAND_RELATIVE
2388 			FLAGS1(lmp) |= FL1_RT_RELATIVE;
2389 #endif
2390 		}
2391 	}
2392 
2393 	if (rpath)
2394 		RPATH(lmp) = (char *)(rpath + (char *)STRTAB(lmp));
2395 	if (fltr) {
2396 		/*
2397 		 * If this object is a global filter, duplicate the filtee
2398 		 * string name(s) so that REFNAME() is available in core files.
2399 		 * This cludge was useful for debuggers at one point, but only
2400 		 * when the filtee name was an individual full path.
2401 		 */
2402 		if ((REFNAME(lmp) = strdup(fltr + (char *)STRTAB(lmp))) == 0) {
2403 			remove_so(0, lmp);
2404 			return (0);
2405 		}
2406 	}
2407 
2408 	if (rtld_flags & RT_FL_RELATIVE)
2409 		FLAGS1(lmp) |= FL1_RT_RELATIVE;
2410 
2411 	/*
2412 	 * For Intel ABI compatibility.  It's possible that a JMPREL can be
2413 	 * specified without any other relocations (e.g. a dynamic executable
2414 	 * normally only contains .plt relocations).  If this is the case then
2415 	 * no REL, RELSZ or RELENT will have been created.  For us to be able
2416 	 * to traverse the .plt relocations under LD_BIND_NOW we need to know
2417 	 * the RELENT for these relocations.  Refer to elf_reloc() for more
2418 	 * details.
2419 	 */
2420 	if (!RELENT(lmp) && JMPREL(lmp))
2421 		RELENT(lmp) = sizeof (Rel);
2422 
2423 	/*
2424 	 * Establish any per-object auditing.  If we're establishing `main's
2425 	 * link-map its too early to go searching for audit objects so just
2426 	 * hold the object name for later (see setup()).
2427 	 */
2428 	if (audit) {
2429 		char	*cp = audit + (char *)STRTAB(lmp);
2430 
2431 		if (*cp) {
2432 			if (((AUDITORS(lmp) =
2433 			    calloc(1, sizeof (Audit_desc))) == 0) ||
2434 			    ((AUDITORS(lmp)->ad_name = strdup(cp)) == 0)) {
2435 				remove_so(0, lmp);
2436 				return (0);
2437 			}
2438 			if (lml_main.lm_head) {
2439 				if (audit_setup(lmp, AUDITORS(lmp), 0) == 0) {
2440 					remove_so(0, lmp);
2441 					return (0);
2442 				}
2443 				FLAGS1(lmp) |= AUDITORS(lmp)->ad_flags;
2444 				lml->lm_flags |= LML_FLG_LOCAUDIT;
2445 			}
2446 		}
2447 	}
2448 
2449 	if ((CONDVAR(lmp) = rt_cond_create()) == 0) {
2450 		remove_so(0, lmp);
2451 		return (0);
2452 	}
2453 	if (oname && ((append_alias(lmp, oname, 0)) == 0)) {
2454 		remove_so(0, lmp);
2455 		return (0);
2456 	}
2457 
2458 	/*
2459 	 * Add the mapped object to the end of the link map list.
2460 	 */
2461 	lm_append(lml, lmco, lmp);
2462 	return (lmp);
2463 }
2464 
2465 /*
2466  * Assign hardware/software capabilities.
2467  */
2468 void
2469 cap_assign(Cap *cap, Rt_map *lmp)
2470 {
2471 	while (cap->c_tag != CA_SUNW_NULL) {
2472 		switch (cap->c_tag) {
2473 		case CA_SUNW_HW_1:
2474 			HWCAP(lmp) = cap->c_un.c_val;
2475 			break;
2476 		case CA_SUNW_SF_1:
2477 			SFCAP(lmp) = cap->c_un.c_val;
2478 		}
2479 		cap++;
2480 	}
2481 }
2482 
2483 /*
2484  * Map in an ELF object.
2485  * Takes an open file descriptor for the object to map and its pathname; returns
2486  * a pointer to a Rt_map structure for this object, or 0 on error.
2487  */
2488 static Rt_map *
2489 elf_map_so(Lm_list *lml, Aliste lmco, const char *pname, const char *oname,
2490     int fd)
2491 {
2492 	int		i; 		/* general temporary */
2493 	Off		memsize = 0;	/* total memory size of pathname */
2494 	Off		mentry;		/* entry point */
2495 	Ehdr		*ehdr;		/* ELF header of ld.so */
2496 	Phdr		*phdr;		/* first Phdr in file */
2497 	Phdr		*phdr0;		/* Saved first Phdr in file */
2498 	Phdr		*pptr;		/* working Phdr */
2499 	Phdr		*fph = 0;	/* first loadable Phdr */
2500 	Phdr		*lph;		/* last loadable Phdr */
2501 	Phdr		*lfph = 0;	/* last loadable (filesz != 0) Phdr */
2502 	Phdr		*lmph = 0;	/* last loadable (memsz != 0) Phdr */
2503 	Phdr		*swph = 0;	/* program header for SUNWBSS */
2504 	Phdr		*tlph = 0;	/* program header for PT_TLS */
2505 	Phdr		*unwindph = 0;	/* program header for PT_SUNW_UNWIND */
2506 	Cap		*cap = 0;	/* program header for SUNWCAP */
2507 	Dyn		*mld = 0;	/* DYNAMIC structure for pathname */
2508 	size_t		size;		/* size of elf and program headers */
2509 	caddr_t		faddr = 0;	/* mapping address of pathname */
2510 	Rt_map		*lmp;		/* link map created */
2511 	caddr_t		paddr;		/* start of padded image */
2512 	Off		plen;		/* size of image including padding */
2513 	Half		etype;
2514 	int		fixed;
2515 	Mmap		*mmaps;
2516 	uint_t		mmapcnt = 0;
2517 	Xword		align = 0;
2518 
2519 	/* LINTED */
2520 	ehdr = (Ehdr *)fmap->fm_maddr;
2521 
2522 	/*
2523 	 * If this a relocatable object then special processing is required.
2524 	 */
2525 	if ((etype = ehdr->e_type) == ET_REL)
2526 		return (elf_obj_file(lml, lmco, pname, fd));
2527 
2528 	/*
2529 	 * If this isn't a dynamic executable or shared object we can't process
2530 	 * it.  If this is a dynamic executable then all addresses are fixed.
2531 	 */
2532 	if (etype == ET_EXEC)
2533 		fixed = 1;
2534 	else if (etype == ET_DYN)
2535 		fixed = 0;
2536 	else {
2537 		eprintf(ERR_ELF, MSG_INTL(MSG_GEN_BADTYPE), pname,
2538 		    conv_etype_str(etype));
2539 		return (0);
2540 	}
2541 
2542 	/*
2543 	 * If our original mapped page was not large enough to hold all the
2544 	 * program headers remap them.
2545 	 */
2546 	size = (size_t)((char *)ehdr->e_phoff +
2547 		(ehdr->e_phnum * ehdr->e_phentsize));
2548 	if (size > fmap->fm_fsize) {
2549 		eprintf(ERR_FATAL, MSG_INTL(MSG_GEN_CORTRUNC), pname);
2550 		return (0);
2551 	}
2552 	if (size > fmap->fm_msize) {
2553 		fmap_setup();
2554 		if ((fmap->fm_maddr = mmap(fmap->fm_maddr, size, PROT_READ,
2555 		    fmap->fm_mflags, fd, 0)) == MAP_FAILED) {
2556 			int	err = errno;
2557 			eprintf(ERR_FATAL, MSG_INTL(MSG_SYS_MMAP), pname,
2558 			    strerror(err));
2559 			return (0);
2560 		}
2561 		fmap->fm_msize = size;
2562 		/* LINTED */
2563 		ehdr = (Ehdr *)fmap->fm_maddr;
2564 	}
2565 	/* LINTED */
2566 	phdr0 = phdr = (Phdr *)((char *)ehdr + ehdr->e_ehsize);
2567 
2568 	/*
2569 	 * Get entry point.
2570 	 */
2571 	mentry = ehdr->e_entry;
2572 
2573 	/*
2574 	 * Point at program headers and perform some basic validation.
2575 	 */
2576 	for (i = 0, pptr = phdr; i < (int)ehdr->e_phnum; i++,
2577 	    pptr = (Phdr *)((Off)pptr + ehdr->e_phentsize)) {
2578 		if ((pptr->p_type == PT_LOAD) ||
2579 		    (pptr->p_type == PT_SUNWBSS)) {
2580 
2581 			if (fph == 0) {
2582 				fph = pptr;
2583 			/* LINTED argument lph is initialized in first pass */
2584 			} else if (pptr->p_vaddr <= lph->p_vaddr) {
2585 				eprintf(ERR_ELF, MSG_INTL(MSG_GEN_INVPRGHDR),
2586 				    pname);
2587 				return (0);
2588 			}
2589 
2590 			lph = pptr;
2591 
2592 			if (pptr->p_memsz)
2593 				lmph = pptr;
2594 			if (pptr->p_filesz)
2595 				lfph = pptr;
2596 			if (pptr->p_type == PT_SUNWBSS)
2597 				swph = pptr;
2598 			if (pptr->p_align > align)
2599 				align = pptr->p_align;
2600 
2601 		} else if (pptr->p_type == PT_DYNAMIC)
2602 			mld = (Dyn *)(pptr->p_vaddr);
2603 		else if (pptr->p_type == PT_TLS)
2604 			tlph = pptr;
2605 		else if (pptr->p_type == PT_SUNWCAP)
2606 			cap = (Cap *)(pptr->p_vaddr);
2607 		else if (pptr->p_type == PT_SUNW_UNWIND)
2608 			unwindph = pptr;
2609 	}
2610 
2611 #if defined(MAP_ALIGN)
2612 	/*
2613 	 * Make sure the maximum page alignment is a power of 2 >= the system
2614 	 * page size, for use with MAP_ALIGN.
2615 	 */
2616 	align = M_PROUND(align);
2617 #endif
2618 
2619 	/*
2620 	 * We'd better have at least one loadable segment, together with some
2621 	 * specified file and memory size.
2622 	 */
2623 	if ((fph == 0) || (lmph == 0) || (lfph == 0)) {
2624 		eprintf(ERR_ELF, MSG_INTL(MSG_GEN_NOLOADSEG), pname);
2625 		return (0);
2626 	}
2627 
2628 	/*
2629 	 * Check that the files size accounts for the loadable sections
2630 	 * we're going to map in (failure to do this may cause spurious
2631 	 * bus errors if we're given a truncated file).
2632 	 */
2633 	if (fmap->fm_fsize < ((size_t)lfph->p_offset + lfph->p_filesz)) {
2634 		eprintf(ERR_FATAL, MSG_INTL(MSG_GEN_CORTRUNC), pname);
2635 		return (0);
2636 	}
2637 
2638 	/*
2639 	 * Memsize must be page rounded so that if we add object padding
2640 	 * at the end it will start at the beginning of a page.
2641 	 */
2642 	plen = memsize = M_PROUND((lmph->p_vaddr + lmph->p_memsz) -
2643 	    M_PTRUNC((ulong_t)fph->p_vaddr));
2644 
2645 	/*
2646 	 * Determine if an existing mapping is acceptable.
2647 	 */
2648 	if (interp && (lml->lm_flags & LML_FLG_BASELM) &&
2649 	    (strcmp(pname, interp->i_name) == 0)) {
2650 		/*
2651 		 * If this is the interpreter then it has already been mapped
2652 		 * and we have the address so don't map it again.  Note that
2653 		 * the common occurrence of a reference to the interpretor
2654 		 * (libdl -> ld.so.1) will have been caught during filter
2655 		 * initialization (see elf_lookup_filtee()).  However, some
2656 		 * ELF implementations are known to record libc.so.1 as the
2657 		 * interpretor, and thus this test catches this behavior.
2658 		 */
2659 		paddr = faddr = interp->i_faddr;
2660 
2661 	} else if ((fixed == 0) && (r_debug.rtd_objpad == 0) &&
2662 	    (memsize <= fmap->fm_msize) && ((fph->p_flags & PF_W) == 0) &&
2663 	    (fph->p_filesz == fph->p_memsz) &&
2664 	    (((Xword)fmap->fm_maddr % align) == 0)) {
2665 		/*
2666 		 * If the mapping required has already been established from
2667 		 * the initial page we don't need to do anything more.  Reset
2668 		 * the fmap address so then any later files start a new fmap.
2669 		 * This is really an optimization for filters, such as libdl.so,
2670 		 * which should only require one page.
2671 		 */
2672 		paddr = faddr = fmap->fm_maddr;
2673 		fmap->fm_maddr = 0;
2674 		fmap_setup();
2675 	}
2676 
2677 	/*
2678 	 * Allocate a mapping array to retain mapped segment information.
2679 	 */
2680 	if ((mmaps = calloc(ehdr->e_phnum, sizeof (Mmap))) == 0)
2681 		return (0);
2682 
2683 	/*
2684 	 * If we're reusing an existing mapping determine the objects etext
2685 	 * address.  Otherwise map the file (which will calculate the etext
2686 	 * address as part of the mapping process).
2687 	 */
2688 	if (faddr) {
2689 		caddr_t	base;
2690 
2691 		if (fixed)
2692 			base = 0;
2693 		else
2694 			base = faddr;
2695 
2696 		/* LINTED */
2697 		phdr0 = phdr = (Phdr *)((char *)faddr + ehdr->e_ehsize);
2698 
2699 		for (i = 0, pptr = phdr; i < (int)ehdr->e_phnum; i++,
2700 		    pptr = (Phdr *)((Off)pptr + ehdr->e_phentsize)) {
2701 			if (pptr->p_type != PT_LOAD)
2702 				continue;
2703 
2704 			mmaps[mmapcnt].m_vaddr = (pptr->p_vaddr + base);
2705 			mmaps[mmapcnt].m_msize = pptr->p_memsz;
2706 			mmaps[mmapcnt].m_fsize = pptr->p_filesz;
2707 			mmaps[mmapcnt].m_perm = (PROT_READ | PROT_EXEC);
2708 			mmapcnt++;
2709 
2710 			if (!(pptr->p_flags & PF_W)) {
2711 				fmap->fm_etext = (ulong_t)pptr->p_vaddr +
2712 				    (ulong_t)pptr->p_memsz +
2713 				    (ulong_t)(fixed ? 0 : faddr);
2714 			}
2715 		}
2716 	} else {
2717 		/*
2718 		 * Map the file.
2719 		 */
2720 		if (!(faddr = elf_map_it(pname, memsize, ehdr, fph, lph,
2721 		    &phdr, &paddr, &plen, fixed, fd, align, mmaps, &mmapcnt)))
2722 			return (0);
2723 	}
2724 
2725 	/*
2726 	 * Calculate absolute base addresses and entry points.
2727 	 */
2728 	if (!fixed) {
2729 		if (mld)
2730 			/* LINTED */
2731 			mld = (Dyn *)((Off)mld + faddr);
2732 		if (cap)
2733 			/* LINTED */
2734 			cap = (Cap *)((Off)cap + faddr);
2735 		mentry += (Off)faddr;
2736 	}
2737 
2738 	/*
2739 	 * Create new link map structure for newly mapped shared object.
2740 	 */
2741 	if (!(lmp = elf_new_lm(lml, pname, oname, mld, (ulong_t)faddr,
2742 	    fmap->fm_etext, lmco, memsize, mentry, (ulong_t)paddr, plen, mmaps,
2743 	    mmapcnt))) {
2744 		(void) munmap((caddr_t)faddr, memsize);
2745 		return (0);
2746 	}
2747 
2748 	/*
2749 	 * Start the system loading in the ELF information we'll be processing.
2750 	 */
2751 	if (REL(lmp)) {
2752 		(void) madvise((void *)ADDR(lmp), (uintptr_t)REL(lmp) +
2753 		    (uintptr_t)RELSZ(lmp) - (uintptr_t)ADDR(lmp),
2754 		    MADV_WILLNEED);
2755 	}
2756 
2757 	/*
2758 	 * If this shared object contains a any special segments, record them.
2759 	 */
2760 	if (swph) {
2761 		FLAGS(lmp) |= FLG_RT_SUNWBSS;
2762 		SUNWBSS(lmp) = phdr + (swph - phdr0);
2763 	}
2764 	if (tlph) {
2765 		PTTLS(lmp) = phdr + (tlph - phdr0);
2766 		tls_assign_soffset(lmp);
2767 	}
2768 
2769 	if (unwindph)
2770 		PTUNWIND(lmp) = phdr + (unwindph - phdr0);
2771 
2772 	if (cap)
2773 		cap_assign(cap, lmp);
2774 
2775 	return (lmp);
2776 }
2777 
2778 
2779 /*
2780  * Function to correct protection settings.  Segments are all mapped initially
2781  * with permissions as given in the segment header.  We need to turn on write
2782  * permissions on a text segment if there are any relocations against that
2783  * segment, and them turn write permission back off again before returning
2784  * control to the user.  This function turns the permission on or off depending
2785  * on the value of the argument.
2786  */
2787 int
2788 elf_set_prot(Rt_map * lmp, int permission)
2789 {
2790 	Mmap	*mmaps;
2791 
2792 	/*
2793 	 * If this is an allocated image (ie. a relocatable object) we can't
2794 	 * mprotect() anything.
2795 	 */
2796 	if (FLAGS(lmp) & FLG_RT_IMGALLOC)
2797 		return (1);
2798 
2799 	DBG_CALL(Dbg_file_prot(NAME(lmp), permission));
2800 
2801 	for (mmaps = MMAPS(lmp); mmaps->m_vaddr; mmaps++) {
2802 		if (mmaps->m_perm & PROT_WRITE)
2803 			continue;
2804 
2805 		if (mprotect(mmaps->m_vaddr, mmaps->m_msize,
2806 		    (mmaps->m_perm | permission)) == -1) {
2807 			int	err = errno;
2808 			eprintf(ERR_FATAL, MSG_INTL(MSG_SYS_MPROT),
2809 			    NAME(lmp), strerror(err));
2810 			return (0);
2811 		}
2812 	}
2813 	return (1);
2814 }
2815 
2816 /*
2817  * Build full pathname of shared object from given directory name and filename.
2818  */
2819 static char *
2820 elf_get_so(const char *dir, const char *file)
2821 {
2822 	static char	pname[PATH_MAX];
2823 
2824 	(void) snprintf(pname, PATH_MAX, MSG_ORIG(MSG_FMT_PATH), dir, file);
2825 	return (pname);
2826 }
2827 
2828 /*
2829  * The copy relocation is recorded in a copy structure which will be applied
2830  * after all other relocations are carried out.  This provides for copying data
2831  * that must be relocated itself (ie. pointers in shared objects).  This
2832  * structure also provides a means of binding RTLD_GROUP dependencies to any
2833  * copy relocations that have been taken from any group members.
2834  *
2835  * If the size of the .bss area available for the copy information is not the
2836  * same as the source of the data inform the user if we're under ldd(1) control
2837  * (this checking was only established in 5.3, so by only issuing an error via
2838  * ldd(1) we maintain the standard set by previous releases).
2839  */
2840 int
2841 elf_copy_reloc(char *name, Sym *rsym, Rt_map *rlmp, void *radd, Sym *dsym,
2842     Rt_map *dlmp, const void *dadd)
2843 {
2844 	Rel_copy	rc;
2845 	Lm_list		*lml = LIST(rlmp);
2846 
2847 	rc.r_name = name;
2848 	rc.r_rsym = rsym;		/* the new reference symbol and its */
2849 	rc.r_rlmp = rlmp;		/*	associated link-map */
2850 	rc.r_dlmp = dlmp;		/* the defining link-map */
2851 	rc.r_dsym = dsym;		/* the original definition */
2852 	rc.r_radd = radd;
2853 	rc.r_dadd = dadd;
2854 
2855 	if (rsym->st_size > dsym->st_size)
2856 		rc.r_size = (size_t)dsym->st_size;
2857 	else
2858 		rc.r_size = (size_t)rsym->st_size;
2859 
2860 	if (alist_append(&COPY(dlmp), &rc, sizeof (Rel_copy),
2861 	    AL_CNT_COPYREL) == 0) {
2862 		if (!(lml->lm_flags & LML_FLG_TRC_WARN))
2863 			return (0);
2864 		else
2865 			return (1);
2866 	}
2867 	if (!(FLAGS1(dlmp) & FL1_RT_COPYTOOK)) {
2868 		if (alist_append(&COPY(rlmp), &dlmp,
2869 		    sizeof (Rt_map *), AL_CNT_COPYREL) == 0) {
2870 			if (!(lml->lm_flags & LML_FLG_TRC_WARN))
2871 				return (0);
2872 			else
2873 				return (1);
2874 		}
2875 		FLAGS1(dlmp) |= FL1_RT_COPYTOOK;
2876 	}
2877 
2878 	/*
2879 	 * If we are tracing (ldd), warn the user if
2880 	 *	1) the size from the reference symbol differs from the
2881 	 *	   copy definition. We can only copy as much data as the
2882 	 *	   reference (dynamic executables) entry allows.
2883 	 *	2) the copy definition has STV_PROTECTED visibility.
2884 	 */
2885 	if (lml->lm_flags & LML_FLG_TRC_WARN) {
2886 		if (rsym->st_size != dsym->st_size) {
2887 			(void) printf(MSG_INTL(MSG_LDD_CPY_SIZDIF),
2888 			    _conv_reloc_type_str(M_R_COPY), demangle(name),
2889 			    NAME(rlmp), EC_XWORD(rsym->st_size),
2890 			    NAME(dlmp), EC_XWORD(dsym->st_size));
2891 			if (rsym->st_size > dsym->st_size)
2892 				(void) printf(MSG_INTL(MSG_LDD_CPY_INSDATA),
2893 				    NAME(dlmp));
2894 			else
2895 				(void) printf(MSG_INTL(MSG_LDD_CPY_DATRUNC),
2896 				    NAME(rlmp));
2897 		}
2898 
2899 		if (ELF_ST_VISIBILITY(dsym->st_other) == STV_PROTECTED) {
2900 			(void) printf(MSG_INTL(MSG_LDD_CPY_PROT),
2901 			    _conv_reloc_type_str(M_R_COPY), demangle(name),
2902 				NAME(dlmp));
2903 		}
2904 	}
2905 
2906 	DBG_CALL(Dbg_reloc_apply((Xword)radd, (Xword)rc.r_size));
2907 	return (1);
2908 }
2909 
2910 /*
2911  * Determine the symbol location of an address within a link-map.  Look for
2912  * the nearest symbol (whose value is less than or equal to the required
2913  * address).  This is the object specific part of dladdr().
2914  */
2915 static void
2916 elf_dladdr(ulong_t addr, Rt_map *lmp, Dl_info *dlip, void **info, int flags)
2917 {
2918 	ulong_t		ndx, cnt, base, _value;
2919 	Sym		*sym, *_sym;
2920 	const char	*str;
2921 	int		_flags;
2922 
2923 	/*
2924 	 * If we don't have a .hash table there are no symbols to look at.
2925 	 */
2926 	if (HASH(lmp) == 0)
2927 		return;
2928 
2929 	cnt = HASH(lmp)[1];
2930 	str = STRTAB(lmp);
2931 	sym = SYMTAB(lmp);
2932 
2933 	if (FLAGS(lmp) & FLG_RT_FIXED)
2934 		base = 0;
2935 	else
2936 		base = ADDR(lmp);
2937 
2938 	for (_sym = 0, _value = 0, sym++, ndx = 1; ndx < cnt; ndx++, sym++) {
2939 		ulong_t	value;
2940 
2941 		if (sym->st_shndx == SHN_UNDEF)
2942 			continue;
2943 
2944 		value = sym->st_value + base;
2945 		if (value > addr)
2946 			continue;
2947 		if (value < _value)
2948 			continue;
2949 
2950 		_sym = sym;
2951 		_value = value;
2952 
2953 		/*
2954 		 * Note, because we accept local and global symbols we could
2955 		 * find a section symbol that matches the associated address,
2956 		 * which means that the symbol name will be null.  In this
2957 		 * case continue the search in case we can find a global
2958 		 * symbol of the same value.
2959 		 */
2960 		if ((value == addr) &&
2961 		    (ELF_ST_TYPE(sym->st_info) != STT_SECTION))
2962 			break;
2963 	}
2964 
2965 	_flags = flags & RTLD_DL_MASK;
2966 	if (_sym) {
2967 		if (_flags == RTLD_DL_SYMENT)
2968 			*info = (void *)_sym;
2969 		else if (_flags == RTLD_DL_LINKMAP)
2970 			*info = (void *)lmp;
2971 
2972 		dlip->dli_sname = str + _sym->st_name;
2973 		dlip->dli_saddr = (void *)_value;
2974 	} else {
2975 		/*
2976 		 * addr lies between the beginning of the mapped segment and
2977 		 * the first global symbol. We have no symbol to return
2978 		 * and the caller requires one. We use _START_, the base
2979 		 * address of the mapping.
2980 		 */
2981 
2982 		if (_flags == RTLD_DL_SYMENT) {
2983 			/*
2984 			 * An actual symbol struct is needed, so we
2985 			 * construct one for _START_. To do this in a
2986 			 * fully accurate way requires a different symbol
2987 			 * for each mapped segment. This requires the
2988 			 * use of dynamic memory and a mutex. That's too much
2989 			 * plumbing for a fringe case of limited importance.
2990 			 *
2991 			 * Fortunately, we can simplify:
2992 			 *    - Only the st_size and st_info fields are useful
2993 			 *	outside of the linker internals. The others
2994 			 *	reference things that outside code cannot see,
2995 			 *	and can be set to 0.
2996 			 *    - It's just a label and there is no size
2997 			 *	to report. So, the size should be 0.
2998 			 * This means that only st_info needs a non-zero
2999 			 * (constant) value. A static struct will suffice.
3000 			 * It must be const (readonly) so the caller can't
3001 			 * change its meaning for subsequent callers.
3002 			 */
3003 			static const Sym fsym = { 0, 0, 0,
3004 				ELF_ST_INFO(STB_LOCAL, STT_OBJECT) };
3005 			*info = (void *) &fsym;
3006 		}
3007 
3008 		dlip->dli_sname = MSG_ORIG(MSG_SYM_START);
3009 		dlip->dli_saddr = (void *) ADDR(lmp);
3010 	}
3011 }
3012 
3013 static void
3014 elf_lazy_cleanup(Alist * alp)
3015 {
3016 	Rt_map **	lmpp;
3017 	Aliste		off;
3018 
3019 	/*
3020 	 * Cleanup any link-maps added to this dynamic list and free it.
3021 	 */
3022 	for (ALIST_TRAVERSE(alp, off, lmpp))
3023 		FLAGS(*lmpp) &= ~FLG_RT_DLSYM;
3024 	free(alp);
3025 }
3026 
3027 /*
3028  * This routine is called upon to search for a symbol from the dependencies of
3029  * the initial link-map.  To maintain lazy loadings goal of reducing the number
3030  * of objects mapped, any symbol search is first carried out using the objects
3031  * that already exist in the process (either on a link-map list or handle).
3032  * If a symbol can't be found, and lazy dependencies are still pending, this
3033  * routine loads the dependencies in an attempt to locate the symbol.
3034  *
3035  * Only new objects are inspected as we will have already inspected presently
3036  * loaded objects before calling this routine.  However, a new object may not
3037  * be new - although the di_lmp might be zero, the object may have been mapped
3038  * as someone elses dependency.  Thus there's a possibility of some symbol
3039  * search duplication.
3040  */
3041 
3042 Sym *
3043 elf_lazy_find_sym(Slookup *slp, Rt_map **_lmp, uint_t *binfo)
3044 {
3045 	Sym		*sym = 0;
3046 	Alist *		alist = 0;
3047 	Aliste		off;
3048 	Rt_map **	lmpp, *	lmp = slp->sl_imap;
3049 	const char	*name = slp->sl_name;
3050 
3051 	if (alist_append(&alist, &lmp, sizeof (Rt_map *), AL_CNT_LAZYFIND) == 0)
3052 		return (0);
3053 	FLAGS(lmp) |= FLG_RT_DLSYM;
3054 
3055 	for (ALIST_TRAVERSE(alist, off, lmpp)) {
3056 		uint_t	cnt = 0;
3057 		Slookup	sl = *slp;
3058 		Dyninfo	*dip;
3059 
3060 		/*
3061 		 * Loop through the DT_NEEDED entries examining each object for
3062 		 * the symbol.  If the symbol is not found the object is in turn
3063 		 * added to the alist, so that its DT_NEEDED entires may be
3064 		 * examined.
3065 		 */
3066 		lmp = *lmpp;
3067 		for (dip = DYNINFO(lmp); cnt < DYNINFOCNT(lmp); cnt++, dip++) {
3068 			Rt_map *nlmp;
3069 
3070 			if (((dip->di_flags & FLG_DI_NEEDED) == 0) ||
3071 			    dip->di_info)
3072 				continue;
3073 
3074 			/*
3075 			 * If this entry defines a lazy dependency try loading
3076 			 * it.  If the file can't be loaded, consider this
3077 			 * non-fatal and continue the search (lazy loaded
3078 			 * dependencies need not exist and their loading should
3079 			 * only be fatal if called from a relocation).
3080 			 *
3081 			 * If the file is already loaded and relocated we must
3082 			 * still inspect it for symbols, even though it might
3083 			 * have already been searched.  This lazy load operation
3084 			 * might have promoted the permissions of the object,
3085 			 * and thus made the object applicable for this symbol
3086 			 * search, whereas before the object might have been
3087 			 * skipped.
3088 			 */
3089 			if ((nlmp = elf_lazy_load(lmp, cnt, name)) == 0)
3090 				continue;
3091 
3092 			/*
3093 			 * If this object isn't yet a part of the dynamic list
3094 			 * then inspect it for the symbol.  If the symbol isn't
3095 			 * found add the object to the dynamic list so that we
3096 			 * can inspect its dependencies.
3097 			 */
3098 			if (FLAGS(nlmp) & FLG_RT_DLSYM)
3099 				continue;
3100 
3101 			sl.sl_imap = nlmp;
3102 			if (sym = LM_LOOKUP_SYM(sl.sl_cmap)(&sl, _lmp, binfo))
3103 				break;
3104 
3105 			/*
3106 			 * Some dlsym() operations are already traversing a
3107 			 * link-map (dlopen(0)), and thus there's no need to
3108 			 * build our own dynamic dependency list.
3109 			 */
3110 			if ((sl.sl_flags & LKUP_NODESCENT) == 0) {
3111 				if (alist_append(&alist, &nlmp,
3112 				    sizeof (Rt_map *), AL_CNT_LAZYFIND) == 0) {
3113 					elf_lazy_cleanup(alist);
3114 					return (0);
3115 				}
3116 				FLAGS(nlmp) |= FLG_RT_DLSYM;
3117 			}
3118 		}
3119 		if (sym)
3120 			break;
3121 	}
3122 
3123 	elf_lazy_cleanup(alist);
3124 	return (sym);
3125 }
3126 
3127 /*
3128  * Warning message for bad r_offset.
3129  */
3130 void
3131 elf_reloc_bad(Rt_map *lmp, void *rel, uchar_t rtype, ulong_t roffset,
3132     ulong_t rsymndx)
3133 {
3134 	const char	*name = (char *)0;
3135 	int		trace;
3136 
3137 	if ((LIST(lmp)->lm_flags & LML_FLG_TRC_ENABLE) &&
3138 	    (((rtld_flags & RT_FL_SILENCERR) == 0) ||
3139 	    (LIST(lmp)->lm_flags & LML_FLG_TRC_VERBOSE)))
3140 		trace = 1;
3141 	else
3142 		trace = 0;
3143 
3144 	if ((trace == 0) && (dbg_mask == 0))
3145 		return;
3146 
3147 	if (rsymndx) {
3148 		Sym	*symref = (Sym *)((ulong_t)SYMTAB(lmp) +
3149 				(rsymndx * SYMENT(lmp)));
3150 
3151 		if (ELF_ST_BIND(symref->st_info) != STB_LOCAL)
3152 			name = (char *)(STRTAB(lmp) + symref->st_name);
3153 	}
3154 
3155 	if (name == 0)
3156 		name = MSG_ORIG(MSG_STR_EMPTY);
3157 
3158 	if (trace) {
3159 		const char *rstr;
3160 
3161 		rstr = _conv_reloc_type_str((uint_t)rtype);
3162 		(void) printf(MSG_INTL(MSG_LDD_REL_ERR1), rstr, name,
3163 		    EC_ADDR(roffset));
3164 		return;
3165 	}
3166 
3167 	Dbg_reloc_error(M_MACH, M_REL_SHT_TYPE, rel, name,
3168 		MSG_ORIG(MSG_REL_BADROFFSET));
3169 }
3170