1 /* $OpenBSD: resolve.c,v 1.91 2019/07/21 03:54:16 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 <nlist.h> 35 #include <link.h> 36 #include "syscall.h" 37 #include "archdep.h" 38 #include "path.h" 39 #include "resolve.h" 40 41 /* substitution types */ 42 typedef enum { 43 SUBST_UNKNOWN, SUBST_ORIGIN, SUBST_OSNAME, SUBST_OSREL, SUBST_PLATFORM 44 } SUBST_TYPES; 45 46 struct symlookup { 47 const char *sl_name; 48 const elf_object_t *sl_obj_out; 49 const Elf_Sym *sl_sym_out; 50 const elf_object_t *sl_weak_obj_out; 51 const Elf_Sym *sl_weak_sym_out; 52 unsigned long sl_elf_hash; 53 uint32_t sl_gnu_hash; 54 int sl_flags; 55 }; 56 57 elf_object_t *_dl_objects; 58 elf_object_t *_dl_last_object; 59 elf_object_t *_dl_loading_object; 60 61 /* 62 * Add a new dynamic object to the object list. 63 */ 64 void 65 _dl_add_object(elf_object_t *object) 66 { 67 /* 68 * If a .so is marked nodelete, then the entire load group that it's 69 * in needs to be kept around forever, so add a reference there. 70 * XXX It would be better if we tracked inter-object dependencies 71 * from relocations and didn't leave dangling pointers when a load 72 * group was partially unloaded. That would render this unnecessary. 73 */ 74 if (object->obj_flags & DF_1_NODELETE && 75 (object->load_object->status & STAT_NODELETE) == 0) { 76 DL_DEB(("objname %s is nodelete\n", object->load_name)); 77 object->load_object->opencount++; 78 object->load_object->status |= STAT_NODELETE; 79 } 80 81 /* 82 * if this is a new object, prev will be NULL 83 * != NULL if an object already in the list 84 * prev == NULL for the first item in the list, but that will 85 * be the executable. 86 */ 87 if (object->prev != NULL) 88 return; 89 90 if (_dl_objects == NULL) { /* First object ? */ 91 _dl_last_object = _dl_objects = object; 92 } else { 93 _dl_last_object->next = object; 94 object->prev = _dl_last_object; 95 _dl_last_object = object; 96 } 97 } 98 99 /* 100 * Identify substitution sequence name. 101 */ 102 static int 103 _dl_subst_name(const char *name, size_t siz) { 104 switch (siz) { 105 case 5: 106 if (_dl_strncmp(name, "OSREL", 5) == 0) 107 return SUBST_OSREL; 108 break; 109 case 6: 110 if (_dl_strncmp(name, "ORIGIN", 6) == 0) 111 return SUBST_ORIGIN; 112 if (_dl_strncmp(name, "OSNAME", 6) == 0) 113 return SUBST_OSNAME; 114 break; 115 case 8: 116 if (_dl_strncmp(name, "PLATFORM", 8) == 0) 117 return SUBST_PLATFORM; 118 break; 119 } 120 121 return (SUBST_UNKNOWN); 122 } 123 124 /* 125 * Perform $ORIGIN substitutions on path 126 */ 127 static void 128 _dl_origin_subst_path(elf_object_t *object, const char *origin_path, 129 char **path) 130 { 131 char tmp_path[PATH_MAX]; 132 char *new_path, *tp; 133 const char *pp, *name, *value; 134 static struct utsname uts; 135 size_t value_len; 136 int skip_brace; 137 138 if (uts.sysname[0] == '\0') { 139 if (_dl_uname(&uts) != 0) 140 return; 141 } 142 143 tp = tmp_path; 144 pp = *path; 145 146 while (*pp != '\0' && (tp - tmp_path) < sizeof(tmp_path)) { 147 148 /* copy over chars up to but not including $ */ 149 while (*pp != '\0' && *pp != '$' && 150 (tp - tmp_path) < sizeof(tmp_path)) 151 *tp++ = *pp++; 152 153 /* substitution sequence detected */ 154 if (*pp == '$' && (tp - tmp_path) < sizeof(tmp_path)) { 155 pp++; 156 157 if ((skip_brace = (*pp == '{'))) 158 pp++; 159 160 /* skip over name */ 161 name = pp; 162 while (_dl_isalnum((unsigned char)*pp) || *pp == '_') 163 pp++; 164 165 switch (_dl_subst_name(name, pp - name)) { 166 case SUBST_ORIGIN: 167 value = origin_path; 168 break; 169 case SUBST_OSNAME: 170 value = uts.sysname; 171 break; 172 case SUBST_OSREL: 173 value = uts.release; 174 break; 175 case SUBST_PLATFORM: 176 value = uts.machine; 177 break; 178 default: 179 value = ""; 180 } 181 182 value_len = _dl_strlen(value); 183 if (value_len >= sizeof(tmp_path) - (tp - tmp_path)) 184 return; 185 186 _dl_bcopy(value, tp, value_len); 187 tp += value_len; 188 189 if (skip_brace && *pp == '}') 190 pp++; 191 } 192 } 193 194 /* no substitution made if result exceeds sizeof(tmp_path) */ 195 if (tp - tmp_path >= sizeof(tmp_path)) 196 return; 197 198 /* NULL terminate tmp_path */ 199 *tp = '\0'; 200 201 if (_dl_strcmp(tmp_path, *path) == 0) 202 return; 203 204 new_path = _dl_strdup(tmp_path); 205 if (new_path == NULL) 206 return; 207 208 DL_DEB(("orig_path %s\n", *path)); 209 DL_DEB(("new_path %s\n", new_path)); 210 211 _dl_free(*path); 212 *path = new_path; 213 } 214 215 /* 216 * Determine origin_path from object load_name. The origin_path argument 217 * must refer to a buffer capable of storing at least PATH_MAX characters. 218 * Returns 0 on success. 219 */ 220 static int 221 _dl_origin_path(elf_object_t *object, char *origin_path) 222 { 223 const char *dirname_path = _dl_dirname(object->load_name); 224 225 if (dirname_path == NULL) 226 return -1; 227 228 /* syscall in ld.so returns 0/-errno, where libc returns char* */ 229 if (_dl___realpath(dirname_path, origin_path) < 0) 230 return -1; 231 232 return 0; 233 } 234 235 /* 236 * Perform $ORIGIN substitutions on runpath and rpath 237 */ 238 static void 239 _dl_origin_subst(elf_object_t *object) 240 { 241 char origin_path[PATH_MAX]; 242 char **pp; 243 244 if (_dl_origin_path(object, origin_path) != 0) 245 return; 246 247 /* perform path substitutions on each segment of runpath and rpath */ 248 if (object->runpath != NULL) { 249 for (pp = object->runpath; *pp != NULL; pp++) 250 _dl_origin_subst_path(object, origin_path, pp); 251 } 252 if (object->rpath != NULL) { 253 for (pp = object->rpath; *pp != NULL; pp++) 254 _dl_origin_subst_path(object, origin_path, pp); 255 } 256 } 257 258 /* 259 * Initialize a new dynamic object. 260 */ 261 elf_object_t * 262 _dl_finalize_object(const char *objname, Elf_Dyn *dynp, Elf_Phdr *phdrp, 263 int phdrc, const int objtype, const long lbase, const long obase) 264 { 265 elf_object_t *object; 266 Elf_Addr gnu_hash = 0; 267 268 #if 0 269 _dl_printf("objname [%s], dynp %p, objtype %x lbase %lx, obase %lx\n", 270 objname, dynp, objtype, lbase, obase); 271 #endif 272 object = _dl_calloc(1, sizeof(elf_object_t)); 273 if (object == NULL) 274 _dl_oom(); 275 object->prev = object->next = NULL; 276 277 object->load_dyn = dynp; 278 while (dynp->d_tag != DT_NULL) { 279 if (dynp->d_tag < DT_NUM) 280 object->Dyn.info[dynp->d_tag] = dynp->d_un.d_val; 281 else if (dynp->d_tag >= DT_LOPROC && 282 dynp->d_tag < DT_LOPROC + DT_PROCNUM) 283 object->Dyn.info[dynp->d_tag + DT_NUM - DT_LOPROC] = 284 dynp->d_un.d_val; 285 if (dynp->d_tag == DT_TEXTREL) 286 object->dyn.textrel = 1; 287 if (dynp->d_tag == DT_SYMBOLIC) 288 object->dyn.symbolic = 1; 289 if (dynp->d_tag == DT_BIND_NOW) 290 object->obj_flags |= DF_1_NOW; 291 if (dynp->d_tag == DT_FLAGS_1) 292 object->obj_flags |= dynp->d_un.d_val; 293 if (dynp->d_tag == DT_FLAGS) { 294 object->dyn.flags |= dynp->d_un.d_val; 295 if (dynp->d_un.d_val & DF_SYMBOLIC) 296 object->dyn.symbolic = 1; 297 if (dynp->d_un.d_val & DF_TEXTREL) 298 object->dyn.textrel = 1; 299 if (dynp->d_un.d_val & DF_ORIGIN) 300 object->obj_flags |= DF_1_ORIGIN; 301 if (dynp->d_un.d_val & DF_BIND_NOW) 302 object->obj_flags |= DF_1_NOW; 303 } 304 if (dynp->d_tag == DT_RELACOUNT) 305 object->relacount = dynp->d_un.d_val; 306 if (dynp->d_tag == DT_RELCOUNT) 307 object->relcount = dynp->d_un.d_val; 308 if (dynp->d_tag == DT_GNU_HASH) 309 gnu_hash = dynp->d_un.d_val; 310 dynp++; 311 } 312 DL_DEB((" flags %s = 0x%x\n", objname, object->obj_flags )); 313 object->obj_type = objtype; 314 315 if (_dl_loading_object == NULL) { 316 /* 317 * no loading object, object is the loading object, 318 * as it is either executable, or dlopened() 319 */ 320 _dl_loading_object = object; 321 } 322 323 if ((object->obj_flags & DF_1_NOOPEN) != 0 && 324 _dl_loading_object->obj_type == OBJTYPE_DLO && 325 !_dl_traceld) { 326 _dl_free(object); 327 _dl_errno = DL_CANT_LOAD_OBJ; 328 return(NULL); 329 } 330 331 /* 332 * Now relocate all pointer to dynamic info, but only 333 * the ones which have pointer values. 334 */ 335 if (object->Dyn.info[DT_PLTGOT]) 336 object->Dyn.info[DT_PLTGOT] += obase; 337 if (object->Dyn.info[DT_STRTAB]) 338 object->Dyn.info[DT_STRTAB] += obase; 339 if (object->Dyn.info[DT_SYMTAB]) 340 object->Dyn.info[DT_SYMTAB] += obase; 341 if (object->Dyn.info[DT_RELA]) 342 object->Dyn.info[DT_RELA] += obase; 343 if (object->Dyn.info[DT_SONAME]) 344 object->Dyn.info[DT_SONAME] += object->Dyn.info[DT_STRTAB]; 345 if (object->Dyn.info[DT_RPATH]) 346 object->Dyn.info[DT_RPATH] += object->Dyn.info[DT_STRTAB]; 347 if (object->Dyn.info[DT_RUNPATH]) 348 object->Dyn.info[DT_RUNPATH] += object->Dyn.info[DT_STRTAB]; 349 if (object->Dyn.info[DT_REL]) 350 object->Dyn.info[DT_REL] += obase; 351 if (object->Dyn.info[DT_INIT]) 352 object->Dyn.info[DT_INIT] += obase; 353 if (object->Dyn.info[DT_FINI]) 354 object->Dyn.info[DT_FINI] += obase; 355 if (object->Dyn.info[DT_JMPREL]) 356 object->Dyn.info[DT_JMPREL] += obase; 357 if (object->Dyn.info[DT_INIT_ARRAY]) 358 object->Dyn.info[DT_INIT_ARRAY] += obase; 359 if (object->Dyn.info[DT_FINI_ARRAY]) 360 object->Dyn.info[DT_FINI_ARRAY] += obase; 361 if (object->Dyn.info[DT_PREINIT_ARRAY]) 362 object->Dyn.info[DT_PREINIT_ARRAY] += obase; 363 364 if (gnu_hash) { 365 Elf_Word *hashtab = (Elf_Word *)(gnu_hash + obase); 366 Elf_Word nbuckets = hashtab[0]; 367 Elf_Word nmaskwords = hashtab[2]; 368 369 /* validity check */ 370 if (nbuckets > 0 && (nmaskwords & (nmaskwords - 1)) == 0) { 371 Elf_Word symndx = hashtab[1]; 372 int bloom_size32 = (ELFSIZE / 32) * nmaskwords; 373 374 object->nbuckets = nbuckets; 375 object->symndx_gnu = symndx; 376 object->mask_bm_gnu = nmaskwords - 1; 377 object->shift2_gnu = hashtab[3]; 378 object->bloom_gnu = (Elf_Addr *)(hashtab + 4); 379 object->buckets_gnu = hashtab + 4 + bloom_size32; 380 object->chains_gnu = object->buckets_gnu + nbuckets 381 - symndx; 382 383 /* 384 * If the ELF hash is present, get the total symbol 385 * count ("nchains") from there. Otherwise, count 386 * the entries in the GNU hash chain. 387 */ 388 if (object->Dyn.info[DT_HASH] == 0) { 389 Elf_Word n; 390 391 for (n = 0; n < nbuckets; n++) { 392 Elf_Word bkt = object->buckets_gnu[n]; 393 const Elf_Word *hashval; 394 if (bkt == 0) 395 continue; 396 hashval = &object->chains_gnu[bkt]; 397 do { 398 symndx++; 399 } while ((*hashval++ & 1U) == 0); 400 } 401 object->nchains = symndx; 402 } 403 object->status |= STAT_GNU_HASH; 404 } 405 } 406 if (object->Dyn.info[DT_HASH] != 0) { 407 Elf_Hash_Word *hashtab = 408 (Elf_Hash_Word *)(object->Dyn.info[DT_HASH] + obase); 409 410 object->nchains = hashtab[1]; 411 if (object->nbuckets == 0) { 412 object->nbuckets = hashtab[0]; 413 object->buckets_elf = hashtab + 2; 414 object->chains_elf = object->buckets_elf + 415 object->nbuckets; 416 } 417 } 418 419 object->phdrp = phdrp; 420 object->phdrc = phdrc; 421 object->load_base = lbase; 422 object->obj_base = obase; 423 object->load_name = _dl_strdup(objname); 424 if (object->load_name == NULL) 425 _dl_oom(); 426 object->load_object = _dl_loading_object; 427 if (object->load_object == object) 428 DL_DEB(("head %s\n", object->load_name)); 429 DL_DEB(("obj %s has %s as head\n", object->load_name, 430 _dl_loading_object->load_name )); 431 object->refcount = 0; 432 TAILQ_INIT(&object->child_list); 433 object->opencount = 0; /* # dlopen() & exe */ 434 object->grprefcount = 0; 435 /* default dev, inode for dlopen-able objects. */ 436 object->dev = 0; 437 object->inode = 0; 438 object->grpsym_gen = 0; 439 TAILQ_INIT(&object->grpsym_list); 440 TAILQ_INIT(&object->grpref_list); 441 442 if (object->dyn.runpath) 443 object->runpath = _dl_split_path(object->dyn.runpath); 444 /* 445 * DT_RPATH is ignored if DT_RUNPATH is present...except in 446 * the exe, whose DT_RPATH is a fallback for libs that don't 447 * use DT_RUNPATH 448 */ 449 if (object->dyn.rpath && (object->runpath == NULL || 450 objtype == OBJTYPE_EXE)) 451 object->rpath = _dl_split_path(object->dyn.rpath); 452 if ((object->obj_flags & DF_1_ORIGIN) && _dl_trust) 453 _dl_origin_subst(object); 454 455 _dl_trace_object_setup(object); 456 457 return (object); 458 } 459 460 static void 461 _dl_tailq_free(struct dep_node *n) 462 { 463 struct dep_node *next; 464 465 while (n != NULL) { 466 next = TAILQ_NEXT(n, next_sib); 467 _dl_free(n); 468 n = next; 469 } 470 } 471 472 static elf_object_t *free_objects; 473 474 void 475 _dl_cleanup_objects() 476 { 477 elf_object_t *nobj, *head; 478 struct dep_node *n, *next; 479 480 n = TAILQ_FIRST(&_dlopened_child_list); 481 while (n != NULL) { 482 next = TAILQ_NEXT(n, next_sib); 483 if (OBJECT_DLREF_CNT(n->data) == 0) { 484 TAILQ_REMOVE(&_dlopened_child_list, n, next_sib); 485 _dl_free(n); 486 } 487 n = next; 488 } 489 490 head = free_objects; 491 free_objects = NULL; 492 while (head != NULL) { 493 _dl_free(head->load_name); 494 _dl_free((char *)head->sod.sod_name); 495 _dl_free_path(head->runpath); 496 _dl_free_path(head->rpath); 497 _dl_tailq_free(TAILQ_FIRST(&head->grpsym_list)); 498 _dl_tailq_free(TAILQ_FIRST(&head->child_list)); 499 _dl_tailq_free(TAILQ_FIRST(&head->grpref_list)); 500 nobj = head->next; 501 _dl_free(head); 502 head = nobj; 503 } 504 } 505 506 void 507 _dl_remove_object(elf_object_t *object) 508 { 509 object->prev->next = object->next; 510 if (object->next) 511 object->next->prev = object->prev; 512 513 if (_dl_last_object == object) 514 _dl_last_object = object->prev; 515 516 object->next = free_objects; 517 free_objects = object; 518 } 519 520 521 Elf_Addr 522 _dl_find_symbol_bysym(elf_object_t *req_obj, unsigned int symidx, 523 const Elf_Sym **this, int flags, const Elf_Sym *ref_sym, 524 const elf_object_t **pobj) 525 { 526 const Elf_Sym *sym; 527 const char *symn; 528 529 sym = req_obj->dyn.symtab; 530 sym += symidx; 531 symn = req_obj->dyn.strtab + sym->st_name; 532 533 return _dl_find_symbol(symn, this, flags, ref_sym, req_obj, pobj); 534 } 535 536 static int 537 matched_symbol(elf_object_t *obj, const Elf_Sym *sym, struct symlookup *sl) 538 { 539 switch (ELF_ST_TYPE(sym->st_info)) { 540 case STT_FUNC: 541 /* 542 * Allow this symbol if we are referring to a function which 543 * has a value, even if section is UNDEF. This allows &func 544 * to refer to PLT as per the ELF spec. If flags has SYM_PLT 545 * set, we must have actual symbol, so this symbol is skipped. 546 */ 547 if ((sl->sl_flags & SYM_PLT) && sym->st_shndx == SHN_UNDEF) 548 return 0; 549 if (sym->st_value == 0) 550 return 0; 551 break; 552 case STT_NOTYPE: 553 case STT_OBJECT: 554 if (sym->st_value == 0) 555 return 0; 556 #if 0 557 /* FALLTHROUGH */ 558 case STT_TLS: 559 #endif 560 if (sym->st_shndx == SHN_UNDEF) 561 return 0; 562 break; 563 default: 564 return 0; 565 } 566 567 if (sym != sl->sl_sym_out && 568 _dl_strcmp(sl->sl_name, obj->dyn.strtab + sym->st_name)) 569 return 0; 570 571 if (ELF_ST_BIND(sym->st_info) == STB_GLOBAL) { 572 sl->sl_sym_out = sym; 573 sl->sl_obj_out = obj; 574 return 1; 575 } else if (ELF_ST_BIND(sym->st_info) == STB_WEAK) { 576 if (sl->sl_weak_sym_out == NULL) { 577 sl->sl_weak_sym_out = sym; 578 sl->sl_weak_obj_out = obj; 579 } 580 /* done with this object, but need to check other objects */ 581 return -1; 582 } 583 return 0; 584 } 585 586 static int 587 _dl_find_symbol_obj(elf_object_t *obj, struct symlookup *sl) 588 { 589 const Elf_Sym *symt = obj->dyn.symtab; 590 591 if (obj->status & STAT_GNU_HASH) { 592 uint32_t hash = sl->sl_gnu_hash; 593 Elf_Addr bloom_word; 594 unsigned int h1; 595 unsigned int h2; 596 Elf_Word bucket; 597 const Elf_Word *hashval; 598 599 /* pick right bitmask word from Bloom filter array */ 600 bloom_word = obj->bloom_gnu[(hash / ELFSIZE) & 601 obj->mask_bm_gnu]; 602 603 /* calculate modulus ELFSIZE of gnu hash and its derivative */ 604 h1 = hash & (ELFSIZE - 1); 605 h2 = (hash >> obj->shift2_gnu) & (ELFSIZE - 1); 606 607 /* Filter out the "definitely not in set" queries */ 608 if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0) 609 return 0; 610 611 /* Locate hash chain and corresponding value element */ 612 bucket = obj->buckets_gnu[hash % obj->nbuckets]; 613 if (bucket == 0) 614 return 0; 615 hashval = &obj->chains_gnu[bucket]; 616 do { 617 if (((*hashval ^ hash) >> 1) == 0) { 618 const Elf_Sym *sym = symt + 619 (hashval - obj->chains_gnu); 620 621 int r = matched_symbol(obj, sym, sl); 622 if (r) 623 return r > 0; 624 } 625 } while ((*hashval++ & 1U) == 0); 626 } else { 627 Elf_Word si; 628 629 for (si = obj->buckets_elf[sl->sl_elf_hash % obj->nbuckets]; 630 si != STN_UNDEF; si = obj->chains_elf[si]) { 631 const Elf_Sym *sym = symt + si; 632 633 int r = matched_symbol(obj, sym, sl); 634 if (r) 635 return r > 0; 636 } 637 } 638 return 0; 639 } 640 641 Elf_Addr 642 _dl_find_symbol(const char *name, const Elf_Sym **this, 643 int flags, const Elf_Sym *ref_sym, elf_object_t *req_obj, 644 const elf_object_t **pobj) 645 { 646 const unsigned char *p; 647 unsigned char c; 648 struct dep_node *n, *m; 649 struct symlookup sl = { 650 .sl_name = name, 651 .sl_obj_out = NULL, 652 .sl_weak_obj_out = NULL, 653 .sl_weak_sym_out = NULL, 654 .sl_elf_hash = 0, 655 .sl_gnu_hash = 5381, 656 .sl_flags = flags, 657 }; 658 659 /* Calculate both hashes in one pass */ 660 for (p = (const unsigned char *)name; (c = *p) != '\0'; p++) { 661 unsigned long g; 662 sl.sl_elf_hash = (sl.sl_elf_hash << 4) + c; 663 if ((g = sl.sl_elf_hash & 0xf0000000)) 664 sl.sl_elf_hash ^= g >> 24; 665 sl.sl_elf_hash &= ~g; 666 sl.sl_gnu_hash = sl.sl_gnu_hash * 33 + c; 667 } 668 669 if (req_obj->dyn.symbolic) 670 if (_dl_find_symbol_obj(req_obj, &sl)) 671 goto found; 672 673 if (flags & SYM_DLSYM) { 674 if (_dl_find_symbol_obj(req_obj, &sl)) 675 goto found; 676 677 /* weak definition in the specified object is good enough */ 678 if (sl.sl_weak_obj_out != NULL) 679 goto found; 680 681 /* search dlopened obj and all children */ 682 TAILQ_FOREACH(n, &req_obj->load_object->grpsym_list, next_sib) { 683 if (_dl_find_symbol_obj(n->data, &sl)) 684 goto found; 685 } 686 } else { 687 int skip = 0; 688 689 if ((flags & SYM_SEARCH_SELF) || (flags & SYM_SEARCH_NEXT)) 690 skip = 1; 691 692 /* 693 * search dlopened objects: global or req_obj == dlopened_obj 694 * and and it's children 695 */ 696 TAILQ_FOREACH(n, &_dlopened_child_list, next_sib) { 697 if (((n->data->obj_flags & DF_1_GLOBAL) == 0) && 698 (n->data != req_obj->load_object)) 699 continue; 700 701 TAILQ_FOREACH(m, &n->data->grpsym_list, next_sib) { 702 if (skip == 1) { 703 if (m->data == req_obj) { 704 skip = 0; 705 if (flags & SYM_SEARCH_NEXT) 706 continue; 707 } else 708 continue; 709 } 710 if ((flags & SYM_SEARCH_OTHER) && 711 (m->data == req_obj)) 712 continue; 713 if (_dl_find_symbol_obj(m->data, &sl)) 714 goto found; 715 } 716 } 717 } 718 719 found: 720 if (sl.sl_sym_out != NULL) { 721 *this = sl.sl_sym_out; 722 } else if (sl.sl_weak_obj_out != NULL) { 723 sl.sl_obj_out = sl.sl_weak_obj_out; 724 *this = sl.sl_weak_sym_out; 725 } else { 726 if ((ref_sym == NULL || 727 (ELF_ST_BIND(ref_sym->st_info) != STB_WEAK)) && 728 (flags & SYM_WARNNOTFOUND)) 729 _dl_printf("%s:%s: undefined symbol '%s'\n", 730 __progname, req_obj->load_name, name); 731 return (0); 732 } 733 734 if (ref_sym != NULL && ref_sym->st_size != 0 && 735 (ref_sym->st_size != (*this)->st_size) && 736 (ELF_ST_TYPE((*this)->st_info) != STT_FUNC) ) { 737 _dl_printf("%s:%s: %s : WARNING: " 738 "symbol(%s) size mismatch, relink your program\n", 739 __progname, req_obj->load_name, sl.sl_obj_out->load_name, 740 name); 741 } 742 743 if (pobj != NULL) 744 *pobj = sl.sl_obj_out; 745 746 return sl.sl_obj_out->obj_base; 747 } 748 749 void 750 _dl_debug_state(void) 751 { 752 /* Debugger stub */ 753 } 754