resolve.c revision 1.97
1/*	$OpenBSD: resolve.c,v 1.97 2022/01/08 06:49:41 guenther Exp $ */
2
3/*
4 * Copyright (c) 1998 Per Fogelstrom, Opsycon AB
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
16 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
19 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 */
28
29#define _DYN_LOADER
30
31#include <sys/types.h>
32
33#include <limits.h>
34#include <link.h>
35
36#include "util.h"
37#include "path.h"
38#include "resolve.h"
39
40/* substitution types */
41typedef enum {
42	SUBST_UNKNOWN, SUBST_ORIGIN, SUBST_OSNAME, SUBST_OSREL, SUBST_PLATFORM
43} SUBST_TYPES;
44
45struct symlookup {
46	const char		*sl_name;
47	struct sym_res		sl_out;
48	struct sym_res		sl_weak_out;
49	unsigned long		sl_elf_hash;
50	uint32_t		sl_gnu_hash;
51	int			sl_flags;
52};
53
54elf_object_t *_dl_objects;
55int object_count;
56static elf_object_t *_dl_last_object;
57elf_object_t *_dl_loading_object;
58
59void
60_dl_handle_nodelete(elf_object_t *object)
61{
62	/*
63	 * If a .so is marked nodelete, then the entire load group that it's
64	 * in needs to be kept around forever, so add a reference there.
65	 * XXX It would be better if we tracked inter-object dependencies
66	 * from relocations and didn't leave dangling pointers when a load
67	 * group was partially unloaded.  That would render this unnecessary.
68	 */
69	if (object->obj_flags & DF_1_NODELETE &&
70	    (object->load_object->status & STAT_NODELETE) == 0) {
71		DL_DEB(("objname %s is nodelete\n", object->load_name));
72		object->load_object->opencount++;
73		object->load_object->status |= STAT_NODELETE;
74	}
75}
76
77/*
78 * Add a new dynamic object to the object list.
79 */
80void
81_dl_add_object(elf_object_t *object)
82{
83	_dl_handle_nodelete(object);
84
85	/*
86	 * if this is a new object, prev will be NULL
87	 * != NULL if an object already in the list
88	 * prev == NULL for the first item in the list, but that will
89	 * be the executable.
90	 */
91	if (object->prev != NULL)
92		return;
93
94	if (_dl_objects == NULL) {			/* First object ? */
95		_dl_last_object = _dl_objects = object;
96		object_count = 2;			/* count ld.so early */
97	} else {
98		_dl_last_object->next = object;
99		object->prev = _dl_last_object;
100		_dl_last_object = object;
101		if (object->obj_type != OBJTYPE_LDR)	/* see above */
102			object_count++;
103	}
104}
105
106/*
107 * Identify substitution sequence name.
108 */
109static int
110_dl_subst_name(const char *name, size_t siz) {
111	switch (siz) {
112	case 5:
113		if (_dl_strncmp(name, "OSREL", 5) == 0)
114			return SUBST_OSREL;
115		break;
116	case 6:
117		if (_dl_strncmp(name, "ORIGIN", 6) == 0)
118			return SUBST_ORIGIN;
119		if (_dl_strncmp(name, "OSNAME", 6) == 0)
120			return SUBST_OSNAME;
121		break;
122	case 8:
123		if (_dl_strncmp(name, "PLATFORM", 8) == 0)
124			return SUBST_PLATFORM;
125		break;
126	}
127
128	return (SUBST_UNKNOWN);
129}
130
131/*
132 * Perform $ORIGIN substitutions on path
133 */
134static void
135_dl_origin_subst_path(elf_object_t *object, const char *origin_path,
136    char **path)
137{
138	char tmp_path[PATH_MAX];
139	char *new_path, *tp;
140	const char *pp, *name, *value;
141	static struct utsname uts;
142	size_t value_len;
143	int skip_brace;
144
145	if (uts.sysname[0] == '\0') {
146		if (_dl_uname(&uts) != 0)
147			return;
148	}
149
150	tp = tmp_path;
151	pp = *path;
152
153	while (*pp != '\0' && (tp - tmp_path) < sizeof(tmp_path)) {
154
155		/* copy over chars up to but not including $ */
156		while (*pp != '\0' && *pp != '$' &&
157		    (tp - tmp_path) < sizeof(tmp_path))
158			*tp++ = *pp++;
159
160		/* substitution sequence detected */
161		if (*pp == '$' && (tp - tmp_path) < sizeof(tmp_path)) {
162			pp++;
163
164			if ((skip_brace = (*pp == '{')))
165				pp++;
166
167			/* skip over name */
168			name = pp;
169			while (_dl_isalnum((unsigned char)*pp) || *pp == '_')
170				pp++;
171
172			switch (_dl_subst_name(name, pp - name)) {
173			case SUBST_ORIGIN:
174				value = origin_path;
175				break;
176			case SUBST_OSNAME:
177				value = uts.sysname;
178				break;
179			case SUBST_OSREL:
180				value = uts.release;
181				break;
182			case SUBST_PLATFORM:
183				value = uts.machine;
184				break;
185			default:
186				value = "";
187			}
188
189			value_len = _dl_strlen(value);
190			if (value_len >= sizeof(tmp_path) - (tp - tmp_path))
191				return;
192
193			_dl_bcopy(value, tp, value_len);
194			tp += value_len;
195
196			if (skip_brace && *pp == '}')
197				pp++;
198		}
199	}
200
201	/* no substitution made if result exceeds sizeof(tmp_path) */
202	if (tp - tmp_path >= sizeof(tmp_path))
203		return;
204
205	/* NULL terminate tmp_path */
206	*tp = '\0';
207
208	if (_dl_strcmp(tmp_path, *path) == 0)
209		return;
210
211	new_path = _dl_strdup(tmp_path);
212	if (new_path == NULL)
213		return;
214
215	DL_DEB(("orig_path %s\n", *path));
216	DL_DEB(("new_path  %s\n", new_path));
217
218	_dl_free(*path);
219	*path = new_path;
220}
221
222/*
223 * Determine origin_path from object load_name. The origin_path argument
224 * must refer to a buffer capable of storing at least PATH_MAX characters.
225 * Returns 0 on success.
226 */
227static int
228_dl_origin_path(elf_object_t *object, char *origin_path)
229{
230	const char *dirname_path = _dl_dirname(object->load_name);
231
232	if (dirname_path == NULL)
233		return -1;
234
235	/* syscall in ld.so returns 0/-errno, where libc returns char* */
236	if (_dl___realpath(dirname_path, origin_path) < 0)
237		return -1;
238
239	return 0;
240}
241
242/*
243 * Perform $ORIGIN substitutions on runpath and rpath
244 */
245static void
246_dl_origin_subst(elf_object_t *object)
247{
248	char origin_path[PATH_MAX];
249	char **pp;
250
251	if (_dl_origin_path(object, origin_path) != 0)
252		return;
253
254	/* perform path substitutions on each segment of runpath and rpath */
255	if (object->runpath != NULL) {
256		for (pp = object->runpath; *pp != NULL; pp++)
257			_dl_origin_subst_path(object, origin_path, pp);
258	}
259	if (object->rpath != NULL) {
260		for (pp = object->rpath; *pp != NULL; pp++)
261			_dl_origin_subst_path(object, origin_path, pp);
262	}
263}
264
265/*
266 * Initialize a new dynamic object.
267 */
268elf_object_t *
269_dl_finalize_object(const char *objname, Elf_Dyn *dynp, Elf_Phdr *phdrp,
270    int phdrc, const int objtype, const long lbase, const long obase)
271{
272	elf_object_t *object;
273	Elf_Addr gnu_hash = 0;
274
275#if 0
276	_dl_printf("objname [%s], dynp %p, objtype %x lbase %lx, obase %lx\n",
277	    objname, dynp, objtype, lbase, obase);
278#endif
279	object = _dl_calloc(1, sizeof(elf_object_t));
280	if (object == NULL)
281		_dl_oom();
282	object->prev = object->next = NULL;
283
284	object->load_dyn = dynp;
285	while (dynp->d_tag != DT_NULL) {
286		if (dynp->d_tag < DT_NUM)
287			object->Dyn.info[dynp->d_tag] = dynp->d_un.d_val;
288		else if (dynp->d_tag >= DT_LOPROC &&
289		    dynp->d_tag < DT_LOPROC + DT_PROCNUM)
290			object->Dyn.info[dynp->d_tag + DT_NUM - DT_LOPROC] =
291			    dynp->d_un.d_val;
292		if (dynp->d_tag == DT_TEXTREL)
293			object->dyn.textrel = 1;
294		if (dynp->d_tag == DT_SYMBOLIC)
295			object->dyn.symbolic = 1;
296		if (dynp->d_tag == DT_BIND_NOW)
297			object->obj_flags |= DF_1_NOW;
298		if (dynp->d_tag == DT_FLAGS_1)
299			object->obj_flags |= dynp->d_un.d_val;
300		if (dynp->d_tag == DT_FLAGS) {
301			object->dyn.flags |= dynp->d_un.d_val;
302			if (dynp->d_un.d_val & DF_SYMBOLIC)
303				object->dyn.symbolic = 1;
304			if (dynp->d_un.d_val & DF_TEXTREL)
305				object->dyn.textrel = 1;
306			if (dynp->d_un.d_val & DF_ORIGIN)
307				object->obj_flags |= DF_1_ORIGIN;
308			if (dynp->d_un.d_val & DF_BIND_NOW)
309				object->obj_flags |= DF_1_NOW;
310		}
311		if (dynp->d_tag == DT_RELACOUNT)
312			object->relacount = dynp->d_un.d_val;
313		if (dynp->d_tag == DT_RELCOUNT)
314			object->relcount = dynp->d_un.d_val;
315		if (dynp->d_tag == DT_GNU_HASH)
316			gnu_hash = dynp->d_un.d_val;
317		dynp++;
318	}
319	DL_DEB((" flags %s = 0x%x\n", objname, object->obj_flags ));
320	object->obj_type = objtype;
321
322	if (_dl_loading_object == NULL) {
323		/*
324		 * no loading object, object is the loading object,
325		 * as it is either executable, or dlopened()
326		 */
327		_dl_loading_object = object;
328	}
329
330	if ((object->obj_flags & DF_1_NOOPEN) != 0 &&
331	    _dl_loading_object->obj_type == OBJTYPE_DLO &&
332	    !_dl_traceld) {
333		_dl_free(object);
334		_dl_errno = DL_CANT_LOAD_OBJ;
335		return(NULL);
336	}
337
338	/*
339	 *  Now relocate all pointer to dynamic info, but only
340	 *  the ones which have pointer values.
341	 */
342	if (object->Dyn.info[DT_PLTGOT])
343		object->Dyn.info[DT_PLTGOT] += obase;
344	if (object->Dyn.info[DT_STRTAB])
345		object->Dyn.info[DT_STRTAB] += obase;
346	if (object->Dyn.info[DT_SYMTAB])
347		object->Dyn.info[DT_SYMTAB] += obase;
348	if (object->Dyn.info[DT_RELA])
349		object->Dyn.info[DT_RELA] += obase;
350	if (object->Dyn.info[DT_SONAME])
351		object->Dyn.info[DT_SONAME] += object->Dyn.info[DT_STRTAB];
352	if (object->Dyn.info[DT_RPATH])
353		object->Dyn.info[DT_RPATH] += object->Dyn.info[DT_STRTAB];
354	if (object->Dyn.info[DT_RUNPATH])
355		object->Dyn.info[DT_RUNPATH] += object->Dyn.info[DT_STRTAB];
356	if (object->Dyn.info[DT_REL])
357		object->Dyn.info[DT_REL] += obase;
358	if (object->Dyn.info[DT_INIT])
359		object->Dyn.info[DT_INIT] += obase;
360	if (object->Dyn.info[DT_FINI])
361		object->Dyn.info[DT_FINI] += obase;
362	if (object->Dyn.info[DT_JMPREL])
363		object->Dyn.info[DT_JMPREL] += obase;
364	if (object->Dyn.info[DT_INIT_ARRAY])
365		object->Dyn.info[DT_INIT_ARRAY] += obase;
366	if (object->Dyn.info[DT_FINI_ARRAY])
367		object->Dyn.info[DT_FINI_ARRAY] += obase;
368	if (object->Dyn.info[DT_PREINIT_ARRAY])
369		object->Dyn.info[DT_PREINIT_ARRAY] += obase;
370	if (object->Dyn.info[DT_RELR])
371		object->Dyn.info[DT_RELR] += obase;
372
373	if (gnu_hash) {
374		Elf_Word *hashtab = (Elf_Word *)(gnu_hash + obase);
375		Elf_Word nbuckets = hashtab[0];
376		Elf_Word nmaskwords = hashtab[2];
377
378		/* validity check */
379		if (nbuckets > 0 && (nmaskwords & (nmaskwords - 1)) == 0) {
380			Elf_Word symndx = hashtab[1];
381			int bloom_size32 = (ELFSIZE / 32) * nmaskwords;
382
383			object->nbuckets = nbuckets;
384			object->symndx_gnu = symndx;
385			object->mask_bm_gnu = nmaskwords - 1;
386			object->shift2_gnu = hashtab[3];
387			object->bloom_gnu = (Elf_Addr *)(hashtab + 4);
388			object->buckets_gnu = hashtab + 4 + bloom_size32;
389			object->chains_gnu = object->buckets_gnu + nbuckets
390			    - symndx;
391
392			/*
393			 * If the ELF hash is present, get the total symbol
394			 * count ("nchains") from there.  Otherwise, count
395			 * the entries in the GNU hash chain.
396			 */
397			if (object->Dyn.info[DT_HASH] == 0) {
398				Elf_Word n;
399
400				for (n = 0; n < nbuckets; n++) {
401					Elf_Word bkt = object->buckets_gnu[n];
402					const Elf_Word *hashval;
403					if (bkt == 0)
404						continue;
405					hashval = &object->chains_gnu[bkt];
406					do {
407						symndx++;
408					} while ((*hashval++ & 1U) == 0);
409				}
410				object->nchains = symndx;
411			}
412			object->status |= STAT_GNU_HASH;
413		}
414	}
415	if (object->Dyn.info[DT_HASH] != 0) {
416		Elf_Hash_Word *hashtab =
417		    (Elf_Hash_Word *)(object->Dyn.info[DT_HASH] + obase);
418
419		object->nchains = hashtab[1];
420		if (object->nbuckets == 0) {
421			object->nbuckets = hashtab[0];
422			object->buckets_elf = hashtab + 2;
423			object->chains_elf = object->buckets_elf +
424			    object->nbuckets;
425		}
426	}
427
428	object->phdrp = phdrp;
429	object->phdrc = phdrc;
430	object->load_base = lbase;
431	object->obj_base = obase;
432	object->load_name = _dl_strdup(objname);
433	if (object->load_name == NULL)
434		_dl_oom();
435	object->load_object = _dl_loading_object;
436	if (object->load_object == object)
437		DL_DEB(("head %s\n", object->load_name));
438	DL_DEB(("obj %s has %s as head\n", object->load_name,
439	    _dl_loading_object->load_name ));
440	object->refcount = 0;
441	object->opencount = 0;	/* # dlopen() & exe */
442	object->grprefcount = 0;
443	/* default dev, inode for dlopen-able objects. */
444	object->dev = 0;
445	object->inode = 0;
446	object->grpsym_gen = 0;
447	TAILQ_INIT(&object->grpref_list);
448
449	if (object->dyn.runpath)
450		object->runpath = _dl_split_path(object->dyn.runpath);
451	/*
452	 * DT_RPATH is ignored if DT_RUNPATH is present...except in
453	 * the exe, whose DT_RPATH is a fallback for libs that don't
454	 * use DT_RUNPATH
455	 */
456	if (object->dyn.rpath && (object->runpath == NULL ||
457	    objtype == OBJTYPE_EXE))
458		object->rpath = _dl_split_path(object->dyn.rpath);
459	if ((object->obj_flags & DF_1_ORIGIN) && _dl_trust)
460		_dl_origin_subst(object);
461
462	_dl_trace_object_setup(object);
463
464	return (object);
465}
466
467static void
468_dl_tailq_free(struct dep_node *n)
469{
470	struct dep_node *next;
471
472	while (n != NULL) {
473		next = TAILQ_NEXT(n, next_sib);
474		_dl_free(n);
475		n = next;
476	}
477}
478
479static elf_object_t *free_objects;
480
481void
482_dl_cleanup_objects()
483{
484	elf_object_t *nobj, *head;
485	struct dep_node *n, *next;
486
487	n = TAILQ_FIRST(&_dlopened_child_list);
488	while (n != NULL) {
489		next = TAILQ_NEXT(n, next_sib);
490		if (OBJECT_DLREF_CNT(n->data) == 0) {
491			TAILQ_REMOVE(&_dlopened_child_list, n, next_sib);
492			_dl_free(n);
493		}
494		n = next;
495	}
496
497	head = free_objects;
498	free_objects = NULL;
499	while (head != NULL) {
500		_dl_free(head->load_name);
501		_dl_free((char *)head->sod.sod_name);
502		_dl_free_path(head->runpath);
503		_dl_free_path(head->rpath);
504		_dl_free(head->grpsym_vec.vec);
505		_dl_free(head->child_vec.vec);
506		_dl_tailq_free(TAILQ_FIRST(&head->grpref_list));
507		nobj = head->next;
508		_dl_free(head);
509		head = nobj;
510	}
511}
512
513void
514_dl_remove_object(elf_object_t *object)
515{
516	object->prev->next = object->next;
517	if (object->next)
518		object->next->prev = object->prev;
519
520	if (_dl_last_object == object)
521		_dl_last_object = object->prev;
522	object_count--;
523
524	object->next = free_objects;
525	free_objects = object;
526}
527
528static int
529matched_symbol(elf_object_t *obj, const Elf_Sym *sym, struct symlookup *sl)
530{
531	switch (ELF_ST_TYPE(sym->st_info)) {
532	case STT_FUNC:
533		/*
534		 * Allow this symbol if we are referring to a function which
535		 * has a value, even if section is UNDEF.  This allows &func
536		 * to refer to PLT as per the ELF spec.  If flags has SYM_PLT
537		 * set, we must have actual symbol, so this symbol is skipped.
538		 */
539		if ((sl->sl_flags & SYM_PLT) && sym->st_shndx == SHN_UNDEF)
540			return 0;
541		if (sym->st_value == 0)
542			return 0;
543		break;
544	case STT_NOTYPE:
545	case STT_OBJECT:
546		if (sym->st_value == 0)
547			return 0;
548#if 0
549		/* FALLTHROUGH */
550	case STT_TLS:
551#endif
552		if (sym->st_shndx == SHN_UNDEF)
553			return 0;
554		break;
555	default:
556		return 0;
557	}
558
559	if (sym != sl->sl_out.sym &&
560	    _dl_strcmp(sl->sl_name, obj->dyn.strtab + sym->st_name))
561		return 0;
562
563	if (ELF_ST_BIND(sym->st_info) == STB_GLOBAL) {
564		sl->sl_out.sym = sym;
565		sl->sl_out.obj = obj;
566		return 1;
567	} else if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
568		if (sl->sl_weak_out.sym == NULL) {
569			sl->sl_weak_out.sym = sym;
570			sl->sl_weak_out.obj = obj;
571		}
572		/* done with this object, but need to check other objects */
573		return -1;
574	}
575	return 0;
576}
577
578static int
579_dl_find_symbol_obj(elf_object_t *obj, struct symlookup *sl)
580{
581	const Elf_Sym	*symt = obj->dyn.symtab;
582
583	if (obj->status & STAT_GNU_HASH) {
584		uint32_t hash = sl->sl_gnu_hash;
585		Elf_Addr bloom_word;
586		unsigned int h1;
587		unsigned int h2;
588		Elf_Word bucket;
589		const Elf_Word *hashval;
590
591		/* pick right bitmask word from Bloom filter array */
592		bloom_word = obj->bloom_gnu[(hash / ELFSIZE) &
593		    obj->mask_bm_gnu];
594
595		/* calculate modulus ELFSIZE of gnu hash and its derivative */
596		h1 = hash & (ELFSIZE - 1);
597		h2 = (hash >> obj->shift2_gnu) & (ELFSIZE - 1);
598
599		/* Filter out the "definitely not in set" queries */
600		if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0)
601			return 0;
602
603		/* Locate hash chain and corresponding value element */
604		bucket = obj->buckets_gnu[hash % obj->nbuckets];
605		if (bucket == 0)
606			return 0;
607		hashval = &obj->chains_gnu[bucket];
608		do {
609			if (((*hashval ^ hash) >> 1) == 0) {
610				const Elf_Sym *sym = symt +
611				    (hashval - obj->chains_gnu);
612
613				int r = matched_symbol(obj, sym, sl);
614				if (r)
615					return r > 0;
616			}
617		} while ((*hashval++ & 1U) == 0);
618	} else {
619		Elf_Word si;
620
621		for (si = obj->buckets_elf[sl->sl_elf_hash % obj->nbuckets];
622		    si != STN_UNDEF; si = obj->chains_elf[si]) {
623			const Elf_Sym *sym = symt + si;
624
625			int r = matched_symbol(obj, sym, sl);
626			if (r)
627				return r > 0;
628		}
629	}
630	return 0;
631}
632
633struct sym_res
634_dl_find_symbol(const char *name, int flags, const Elf_Sym *ref_sym,
635    elf_object_t *req_obj)
636{
637	const unsigned char *p;
638	unsigned char c;
639	struct symlookup sl = {
640		.sl_name = name,
641		.sl_out = { .sym = NULL },
642		.sl_weak_out = { .sym = NULL },
643		.sl_elf_hash = 0,
644		.sl_gnu_hash = 5381,
645		.sl_flags = flags,
646	};
647
648	/* Calculate both hashes in one pass */
649	for (p = (const unsigned char *)name; (c = *p) != '\0'; p++) {
650		unsigned long g;
651		sl.sl_elf_hash = (sl.sl_elf_hash << 4) + c;
652		if ((g = sl.sl_elf_hash & 0xf0000000))
653			sl.sl_elf_hash ^= g >> 24;
654		sl.sl_elf_hash &= ~g;
655		sl.sl_gnu_hash = sl.sl_gnu_hash * 33 + c;
656	}
657
658	if (req_obj->dyn.symbolic)
659		if (_dl_find_symbol_obj(req_obj, &sl))
660			goto found;
661
662	if (flags & SYM_DLSYM) {
663		struct object_vector vec;
664		int i;
665
666		if (_dl_find_symbol_obj(req_obj, &sl))
667			goto found;
668
669		/* weak definition in the specified object is good enough */
670		if (sl.sl_weak_out.sym != NULL)
671			goto found;
672
673		/* search dlopened obj and all children */
674		vec = req_obj->load_object->grpsym_vec;
675		for (i = 0; i < vec.len; i++) {
676			if (vec.vec[i] == req_obj)
677				continue;		/* already searched */
678			if (_dl_find_symbol_obj(vec.vec[i], &sl))
679				goto found;
680		}
681	} else {
682		struct dep_node *n;
683		struct object_vector vec;
684		int i, skip = 0;
685
686		if ((flags & SYM_SEARCH_SELF) || (flags & SYM_SEARCH_NEXT))
687			skip = 1;
688
689		/*
690		 * search dlopened objects: global or req_obj == dlopened_obj
691		 * and its children
692		 */
693		TAILQ_FOREACH(n, &_dlopened_child_list, next_sib) {
694			if (((n->data->obj_flags & DF_1_GLOBAL) == 0) &&
695			    (n->data != req_obj->load_object))
696				continue;
697
698			vec = n->data->grpsym_vec;
699			for (i = 0; i < vec.len; i++) {
700				if (skip == 1) {
701					if (vec.vec[i] == req_obj) {
702						skip = 0;
703						if (flags & SYM_SEARCH_NEXT)
704							continue;
705					} else
706						continue;
707				}
708				if ((flags & SYM_SEARCH_OTHER) &&
709				    (vec.vec[i] == req_obj))
710					continue;
711				if (_dl_find_symbol_obj(vec.vec[i], &sl))
712					goto found;
713			}
714		}
715	}
716
717found:
718	if (sl.sl_out.sym == NULL) {
719		if (sl.sl_weak_out.sym != NULL)
720			sl.sl_out = sl.sl_weak_out;
721		else {
722			if ((ref_sym == NULL ||
723			    (ELF_ST_BIND(ref_sym->st_info) != STB_WEAK)) &&
724			    (flags & SYM_WARNNOTFOUND))
725				_dl_printf("%s:%s: undefined symbol '%s'\n",
726				    __progname, req_obj->load_name, name);
727			return (struct sym_res){ NULL, NULL };
728		}
729	}
730
731	if (ref_sym != NULL && ref_sym->st_size != 0 &&
732	    (ref_sym->st_size != sl.sl_out.sym->st_size) &&
733	    (ELF_ST_TYPE(sl.sl_out.sym->st_info) != STT_FUNC) ) {
734		_dl_printf("%s:%s: %s : WARNING: "
735		    "symbol(%s) size mismatch, relink your program\n",
736		    __progname, req_obj->load_name, sl.sl_out.obj->load_name,
737		    name);
738	}
739
740	return sl.sl_out;
741}
742
743void
744_dl_debug_state(void)
745{
746	/* Debugger stub */
747}
748