1 /* $OpenBSD: resolve.c,v 1.75 2016/08/23 06:46:17 kettenis 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 elf_object_t *_dl_objects; 47 elf_object_t *_dl_last_object; 48 elf_object_t *_dl_loading_object; 49 50 /* 51 * Add a new dynamic object to the object list. 52 */ 53 void 54 _dl_add_object(elf_object_t *object) 55 { 56 /* 57 * If a .so is marked nodelete, then the entire load group that it's 58 * in needs to be kept around forever, so add a reference there. 59 * XXX It would be better if we tracked inter-object dependencies 60 * from relocations and didn't leave dangling pointers when a load 61 * group was partially unloaded. That would render this unnecessary. 62 */ 63 if (object->obj_flags & DF_1_NODELETE && 64 (object->load_object->status & STAT_NODELETE) == 0) { 65 DL_DEB(("objname %s is nodelete\n", object->load_name)); 66 object->load_object->opencount++; 67 object->load_object->status |= STAT_NODELETE; 68 } 69 70 /* 71 * if this is a new object, prev will be NULL 72 * != NULL if an object already in the list 73 * prev == NULL for the first item in the list, but that will 74 * be the executable. 75 */ 76 if (object->prev != NULL) 77 return; 78 79 if (_dl_objects == NULL) { /* First object ? */ 80 _dl_last_object = _dl_objects = object; 81 } else { 82 _dl_last_object->next = object; 83 object->prev = _dl_last_object; 84 _dl_last_object = object; 85 } 86 } 87 88 /* 89 * Identify substitution sequence name. 90 */ 91 static int 92 _dl_subst_name(const char *name, size_t siz) { 93 switch (siz) { 94 case 5: 95 if (_dl_strncmp(name, "OSREL", 5) == 0) 96 return SUBST_OSREL; 97 break; 98 case 6: 99 if (_dl_strncmp(name, "ORIGIN", 6) == 0) 100 return SUBST_ORIGIN; 101 if (_dl_strncmp(name, "OSNAME", 6) == 0) 102 return SUBST_OSNAME; 103 break; 104 case 8: 105 if (_dl_strncmp(name, "PLATFORM", 8) == 0) 106 return SUBST_PLATFORM; 107 break; 108 } 109 110 return (SUBST_UNKNOWN); 111 } 112 113 /* 114 * Perform $ORIGIN substitutions on path 115 */ 116 static void 117 _dl_origin_subst_path(elf_object_t *object, const char *origin_path, 118 char **path) 119 { 120 char tmp_path[PATH_MAX]; 121 char *new_path, *tp; 122 const char *pp, *name, *value; 123 static struct utsname uts; 124 size_t value_len; 125 int skip_brace; 126 127 if (uts.sysname[0] == '\0') { 128 if (_dl_uname(&uts) != 0) 129 return; 130 } 131 132 tp = tmp_path; 133 pp = *path; 134 135 while (*pp != '\0' && (tp - tmp_path) < sizeof(tmp_path)) { 136 137 /* copy over chars up to but not including $ */ 138 while (*pp != '\0' && *pp != '$' && 139 (tp - tmp_path) < sizeof(tmp_path)) 140 *tp++ = *pp++; 141 142 /* substitution sequence detected */ 143 if (*pp == '$' && (tp - tmp_path) < sizeof(tmp_path)) { 144 pp++; 145 146 if ((skip_brace = (*pp == '{'))) 147 pp++; 148 149 /* skip over name */ 150 name = pp; 151 while (_dl_isalnum((unsigned char)*pp) || *pp == '_') 152 pp++; 153 154 switch (_dl_subst_name(name, pp - name)) { 155 case SUBST_ORIGIN: 156 value = origin_path; 157 break; 158 case SUBST_OSNAME: 159 value = uts.sysname; 160 break; 161 case SUBST_OSREL: 162 value = uts.release; 163 break; 164 case SUBST_PLATFORM: 165 value = uts.machine; 166 break; 167 default: 168 value = ""; 169 } 170 171 value_len = _dl_strlen(value); 172 if (value_len >= sizeof(tmp_path) - (tp - tmp_path)) 173 return; 174 175 _dl_bcopy(value, tp, value_len); 176 tp += value_len; 177 178 if (skip_brace && *pp == '}') 179 pp++; 180 } 181 } 182 183 /* no substitution made if result exceeds sizeof(tmp_path) */ 184 if (tp - tmp_path >= sizeof(tmp_path)) 185 return; 186 187 /* NULL terminate tmp_path */ 188 *tp = '\0'; 189 190 if (_dl_strcmp(tmp_path, *path) == 0) 191 return; 192 193 new_path = _dl_strdup(tmp_path); 194 if (new_path == NULL) 195 return; 196 197 DL_DEB(("orig_path %s\n", *path)); 198 DL_DEB(("new_path %s\n", new_path)); 199 200 _dl_free(*path); 201 *path = new_path; 202 } 203 204 /* 205 * Determine origin_path from object load_name. The origin_path argument 206 * must refer to a buffer capable of storing at least PATH_MAX characters. 207 * Returns 0 on success. 208 */ 209 static int 210 _dl_origin_path(elf_object_t *object, char *origin_path) 211 { 212 const char *dirname_path = _dl_dirname(object->load_name); 213 214 if (dirname_path == NULL) 215 return -1; 216 217 if (_dl_realpath(dirname_path, origin_path) == NULL) 218 return -1; 219 220 return 0; 221 } 222 223 /* 224 * Perform $ORIGIN substitutions on rpath 225 */ 226 static void 227 _dl_origin_subst(elf_object_t *object) 228 { 229 char origin_path[PATH_MAX]; 230 char **pp; 231 232 if (_dl_origin_path(object, origin_path) != 0) 233 return; 234 235 /* perform path substitutions on each segment of rpath */ 236 for (pp = object->rpath; *pp != NULL; pp++) { 237 _dl_origin_subst_path(object, origin_path, pp); 238 } 239 } 240 241 /* 242 * Initialize a new dynamic object. 243 */ 244 elf_object_t * 245 _dl_finalize_object(const char *objname, Elf_Dyn *dynp, Elf_Phdr *phdrp, 246 int phdrc, const int objtype, const long lbase, const long obase) 247 { 248 elf_object_t *object; 249 250 #if 0 251 _dl_printf("objname [%s], dynp %p, objtype %x lbase %lx, obase %lx\n", 252 objname, dynp, objtype, lbase, obase); 253 #endif 254 object = _dl_calloc(1, sizeof(elf_object_t)); 255 if (object == NULL) 256 _dl_exit(7); 257 object->prev = object->next = NULL; 258 259 object->load_dyn = dynp; 260 while (dynp->d_tag != DT_NULL) { 261 if (dynp->d_tag < DT_NUM) 262 object->Dyn.info[dynp->d_tag] = dynp->d_un.d_val; 263 else if (dynp->d_tag >= DT_LOPROC && 264 dynp->d_tag < DT_LOPROC + DT_PROCNUM) 265 object->Dyn.info[dynp->d_tag + DT_NUM - DT_LOPROC] = 266 dynp->d_un.d_val; 267 if (dynp->d_tag == DT_TEXTREL) 268 object->dyn.textrel = 1; 269 if (dynp->d_tag == DT_SYMBOLIC) 270 object->dyn.symbolic = 1; 271 if (dynp->d_tag == DT_BIND_NOW) 272 object->obj_flags |= DF_1_NOW; 273 if (dynp->d_tag == DT_FLAGS_1) 274 object->obj_flags |= dynp->d_un.d_val; 275 if (dynp->d_tag == DT_RELACOUNT) 276 object->relacount = dynp->d_un.d_val; 277 if (dynp->d_tag == DT_RELCOUNT) 278 object->relcount = dynp->d_un.d_val; 279 dynp++; 280 } 281 DL_DEB((" flags %s = 0x%x\n", objname, object->obj_flags )); 282 object->obj_type = objtype; 283 284 if (_dl_loading_object == NULL) { 285 /* 286 * no loading object, object is the loading object, 287 * as it is either executable, or dlopened() 288 */ 289 _dl_loading_object = object; 290 } 291 292 if ((object->obj_flags & DF_1_NOOPEN) != 0 && 293 _dl_loading_object->obj_type == OBJTYPE_DLO && 294 _dl_traceld == NULL) { 295 _dl_free(object); 296 _dl_errno = DL_CANT_LOAD_OBJ; 297 return(NULL); 298 } 299 300 /* 301 * Now relocate all pointer to dynamic info, but only 302 * the ones which have pointer values. 303 */ 304 if (object->Dyn.info[DT_PLTGOT]) 305 object->Dyn.info[DT_PLTGOT] += obase; 306 if (object->Dyn.info[DT_HASH]) 307 object->Dyn.info[DT_HASH] += obase; 308 if (object->Dyn.info[DT_STRTAB]) 309 object->Dyn.info[DT_STRTAB] += obase; 310 if (object->Dyn.info[DT_SYMTAB]) 311 object->Dyn.info[DT_SYMTAB] += obase; 312 if (object->Dyn.info[DT_RELA]) 313 object->Dyn.info[DT_RELA] += obase; 314 if (object->Dyn.info[DT_SONAME]) 315 object->Dyn.info[DT_SONAME] += object->Dyn.info[DT_STRTAB]; 316 if (object->Dyn.info[DT_RPATH]) 317 object->Dyn.info[DT_RPATH] += object->Dyn.info[DT_STRTAB]; 318 if (object->Dyn.info[DT_REL]) 319 object->Dyn.info[DT_REL] += obase; 320 if (object->Dyn.info[DT_INIT]) 321 object->Dyn.info[DT_INIT] += obase; 322 if (object->Dyn.info[DT_FINI]) 323 object->Dyn.info[DT_FINI] += obase; 324 if (object->Dyn.info[DT_JMPREL]) 325 object->Dyn.info[DT_JMPREL] += obase; 326 if (object->Dyn.info[DT_INIT_ARRAY]) 327 object->Dyn.info[DT_INIT_ARRAY] += obase; 328 if (object->Dyn.info[DT_FINI_ARRAY]) 329 object->Dyn.info[DT_FINI_ARRAY] += obase; 330 if (object->Dyn.info[DT_PREINIT_ARRAY]) 331 object->Dyn.info[DT_PREINIT_ARRAY] += obase; 332 333 if (object->Dyn.info[DT_HASH] != 0) { 334 Elf_Word *hashtab = (Elf_Word *)object->Dyn.info[DT_HASH]; 335 336 object->nbuckets = hashtab[0]; 337 object->nchains = hashtab[1]; 338 object->buckets = hashtab + 2; 339 object->chains = object->buckets + object->nbuckets; 340 } 341 342 object->phdrp = phdrp; 343 object->phdrc = phdrc; 344 object->load_base = lbase; 345 object->obj_base = obase; 346 object->load_name = _dl_strdup(objname); 347 if (object->load_name == NULL) 348 _dl_exit(7); 349 object->load_object = _dl_loading_object; 350 if (object->load_object == object) 351 DL_DEB(("head %s\n", object->load_name)); 352 DL_DEB(("obj %s has %s as head\n", object->load_name, 353 _dl_loading_object->load_name )); 354 object->refcount = 0; 355 TAILQ_INIT(&object->child_list); 356 object->opencount = 0; /* # dlopen() & exe */ 357 object->grprefcount = 0; 358 /* default dev, inode for dlopen-able objects. */ 359 object->dev = 0; 360 object->inode = 0; 361 object->grpsym_gen = 0; 362 TAILQ_INIT(&object->grpsym_list); 363 TAILQ_INIT(&object->grpref_list); 364 365 if (object->dyn.rpath) { 366 object->rpath = _dl_split_path(object->dyn.rpath); 367 if ((object->obj_flags & DF_1_ORIGIN) && _dl_trust) 368 _dl_origin_subst(object); 369 } 370 371 _dl_trace_object_setup(object); 372 373 return (object); 374 } 375 376 static void 377 _dl_tailq_free(struct dep_node *n) 378 { 379 struct dep_node *next; 380 381 while (n != NULL) { 382 next = TAILQ_NEXT(n, next_sib); 383 _dl_free(n); 384 n = next; 385 } 386 } 387 388 elf_object_t *free_objects; 389 390 void 391 _dl_cleanup_objects() 392 { 393 elf_object_t *nobj, *head; 394 struct dep_node *n, *next; 395 396 n = TAILQ_FIRST(&_dlopened_child_list); 397 while (n != NULL) { 398 next = TAILQ_NEXT(n, next_sib); 399 if (OBJECT_DLREF_CNT(n->data) == 0) { 400 TAILQ_REMOVE(&_dlopened_child_list, n, next_sib); 401 _dl_free(n); 402 } 403 n = next; 404 } 405 406 head = free_objects; 407 free_objects = NULL; 408 while (head != NULL) { 409 if (head->load_name) 410 _dl_free(head->load_name); 411 if (head->sod.sod_name) 412 _dl_free((char *)head->sod.sod_name); 413 if (head->rpath) 414 _dl_free_path(head->rpath); 415 _dl_tailq_free(TAILQ_FIRST(&head->grpsym_list)); 416 _dl_tailq_free(TAILQ_FIRST(&head->child_list)); 417 _dl_tailq_free(TAILQ_FIRST(&head->grpref_list)); 418 nobj = head->next; 419 _dl_free(head); 420 head = nobj; 421 } 422 } 423 424 void 425 _dl_remove_object(elf_object_t *object) 426 { 427 object->prev->next = object->next; 428 if (object->next) 429 object->next->prev = object->prev; 430 431 if (_dl_last_object == object) 432 _dl_last_object = object->prev; 433 434 object->next = free_objects; 435 free_objects = object; 436 } 437 438 /* 439 * mprotect a segment to the indicated protection. If 'addr' is non-zero, 440 * then it's the start address, else the value of 'start_sym' is the start. 441 * The value of 'end_sym' is the end address. The start is rounded down 442 * and the end is rounded up to page boundaries. Returns 'addr' or the 443 * address of the start symbol. 444 */ 445 void * 446 _dl_protect_segment(elf_object_t *object, Elf_Addr addr, 447 const char *start_sym, const char *end_sym, int prot) 448 { 449 const Elf_Sym *this; 450 Elf_Addr ooff, start, end; 451 452 if (addr == 0 && start_sym[2] == 'g' && 453 (addr = object->relro_addr) != 0) { 454 DL_DEB(("protect start RELRO = 0x%lx in %s\n", 455 addr, object->load_name)); 456 } 457 else if (addr == 0) { 458 this = NULL; 459 ooff = _dl_find_symbol(start_sym, &this, 460 SYM_SEARCH_OBJ | SYM_NOWARNNOTFOUND | SYM_PLT, NULL, 461 object, NULL); 462 /* If not found, nothing to do */ 463 if (this == NULL) { 464 DL_DEB(("protect start \"%s\" not found in %s\n", 465 start_sym, object->load_name)); 466 return (NULL); 467 } 468 addr = ooff + this->st_value; 469 DL_DEB(("protect start \"%s\" to %x = 0x%lx in %s\n", 470 start_sym, prot, addr, object->load_name)); 471 } 472 473 if (object->relro_addr != 0 && start_sym[2] == 'g') { 474 end = object->relro_addr + object->relro_size; 475 DL_DEB(("protect end RELRO = 0x%lx in %s\n", 476 end, object->load_name)); 477 } else { 478 this = NULL; 479 ooff = _dl_find_symbol(end_sym, &this, 480 SYM_SEARCH_OBJ | SYM_NOWARNNOTFOUND | SYM_PLT, NULL, 481 object, NULL); 482 if (this == NULL) { 483 DL_DEB(("protect end \"%s\" not found in %s\n", 484 end_sym, object->load_name)); 485 addr = 0; 486 } else { 487 end = ooff + this->st_value; 488 DL_DEB(("protect end \"%s\" = 0x%lx in %s\n", 489 end_sym, end, object->load_name)); 490 } 491 } 492 493 if (addr != 0 && addr < end) { 494 start = ELF_TRUNC(addr, _dl_pagesz); 495 end = ELF_ROUND(end, _dl_pagesz); 496 _dl_mprotect((void *)start, end - start, prot); 497 } 498 499 return ((void *)addr); 500 } 501 502 503 sym_cache *_dl_symcache; 504 int _dl_symcachestat_hits; 505 int _dl_symcachestat_lookups; 506 507 508 Elf_Addr 509 _dl_find_symbol_bysym(elf_object_t *req_obj, unsigned int symidx, 510 const Elf_Sym **this, int flags, const Elf_Sym *ref_sym, const elf_object_t **pobj) 511 { 512 Elf_Addr ret; 513 const Elf_Sym *sym; 514 const char *symn; 515 const elf_object_t *sobj; 516 517 _dl_symcachestat_lookups ++; 518 if (_dl_symcache != NULL && 519 symidx < req_obj->nchains && 520 _dl_symcache[symidx].obj != NULL && 521 _dl_symcache[symidx].sym != NULL && 522 _dl_symcache[symidx].flags == flags) { 523 524 _dl_symcachestat_hits++; 525 sobj = _dl_symcache[symidx].obj; 526 *this = _dl_symcache[symidx].sym; 527 if (pobj) 528 *pobj = sobj; 529 return sobj->obj_base; 530 } 531 532 sym = req_obj->dyn.symtab; 533 sym += symidx; 534 symn = req_obj->dyn.strtab + sym->st_name; 535 536 ret = _dl_find_symbol(symn, this, flags, ref_sym, req_obj, &sobj); 537 538 if (pobj) 539 *pobj = sobj; 540 541 if (_dl_symcache != NULL && symidx < req_obj->nchains) { 542 #if 0 543 DL_DEB(("cache miss %d %p %p, %p %p %s %s %d %d %s\n", 544 symidx, 545 _dl_symcache[symidx].sym, *this, 546 _dl_symcache[symidx].obj, sobj, sobj->load_name, 547 sobj->dyn.strtab + (*this)->st_name, 548 _dl_symcache[symidx].flags, flags, req_obj->load_name)); 549 #endif 550 551 _dl_symcache[symidx].sym = *this; 552 _dl_symcache[symidx].obj = sobj; 553 _dl_symcache[symidx].flags = flags; 554 } 555 556 return ret; 557 } 558 559 static int 560 _dl_find_symbol_obj(elf_object_t *object, const char *name, unsigned long hash, 561 int flags, const Elf_Sym **this, const Elf_Sym **weak_sym, 562 elf_object_t **weak_object) 563 { 564 const Elf_Sym *symt = object->dyn.symtab; 565 const char *strt = object->dyn.strtab; 566 long si; 567 const char *symn; 568 569 for (si = object->buckets[hash % object->nbuckets]; 570 si != STN_UNDEF; si = object->chains[si]) { 571 const Elf_Sym *sym = symt + si; 572 573 if (sym->st_value == 0) 574 continue; 575 576 if (ELF_ST_TYPE(sym->st_info) != STT_NOTYPE && 577 ELF_ST_TYPE(sym->st_info) != STT_OBJECT && 578 ELF_ST_TYPE(sym->st_info) != STT_FUNC) 579 continue; 580 581 symn = strt + sym->st_name; 582 if (sym != *this && _dl_strcmp(symn, name)) 583 continue; 584 585 /* allow this symbol if we are referring to a function 586 * which has a value, even if section is UNDEF. 587 * this allows &func to refer to PLT as per the 588 * ELF spec. st_value is checked above. 589 * if flags has SYM_PLT set, we must have actual 590 * symbol, so this symbol is skipped. 591 */ 592 if (sym->st_shndx == SHN_UNDEF) { 593 if ((flags & SYM_PLT) || sym->st_value == 0 || 594 ELF_ST_TYPE(sym->st_info) != STT_FUNC) 595 continue; 596 } 597 598 if (ELF_ST_BIND(sym->st_info) == STB_GLOBAL) { 599 *this = sym; 600 return 1; 601 } else if (ELF_ST_BIND(sym->st_info) == STB_WEAK) { 602 if (!*weak_sym) { 603 *weak_sym = sym; 604 *weak_object = object; 605 } 606 } 607 } 608 return 0; 609 } 610 611 Elf_Addr 612 _dl_find_symbol(const char *name, const Elf_Sym **this, 613 int flags, const Elf_Sym *ref_sym, elf_object_t *req_obj, 614 const elf_object_t **pobj) 615 { 616 const Elf_Sym *weak_sym = NULL; 617 unsigned long h = 0; 618 const char *p = name; 619 elf_object_t *object = NULL, *weak_object = NULL; 620 int found = 0; 621 struct dep_node *n, *m; 622 623 624 while (*p) { 625 unsigned long g; 626 h = (h << 4) + *p++; 627 if ((g = h & 0xf0000000)) 628 h ^= g >> 24; 629 h &= ~g; 630 } 631 632 if (req_obj->dyn.symbolic) 633 if (_dl_find_symbol_obj(req_obj, name, h, flags, this, &weak_sym, 634 &weak_object)) { 635 object = req_obj; 636 found = 1; 637 goto found; 638 } 639 640 if (flags & SYM_SEARCH_OBJ) { 641 if (_dl_find_symbol_obj(req_obj, name, h, flags, this, 642 &weak_sym, &weak_object)) { 643 object = req_obj; 644 found = 1; 645 } 646 } else if (flags & SYM_DLSYM) { 647 if (_dl_find_symbol_obj(req_obj, name, h, flags, this, 648 &weak_sym, &weak_object)) { 649 object = req_obj; 650 found = 1; 651 } 652 if (weak_object != NULL && found == 0) { 653 object=weak_object; 654 *this = weak_sym; 655 found = 1; 656 } 657 /* search dlopened obj and all children */ 658 659 if (found == 0) { 660 TAILQ_FOREACH(n, &req_obj->load_object->grpsym_list, 661 next_sib) { 662 if (_dl_find_symbol_obj(n->data, name, h, 663 flags, this, 664 &weak_sym, &weak_object)) { 665 object = n->data; 666 found = 1; 667 break; 668 } 669 } 670 } 671 } else { 672 int skip = 0; 673 674 if ((flags & SYM_SEARCH_SELF) || (flags & SYM_SEARCH_NEXT)) 675 skip = 1; 676 677 /* 678 * search dlopened objects: global or req_obj == dlopened_obj 679 * and and it's children 680 */ 681 TAILQ_FOREACH(n, &_dlopened_child_list, next_sib) { 682 if (((n->data->obj_flags & DF_1_GLOBAL) == 0) && 683 (n->data != req_obj->load_object)) 684 continue; 685 686 TAILQ_FOREACH(m, &n->data->grpsym_list, next_sib) { 687 if (skip == 1) { 688 if (m->data == req_obj) { 689 skip = 0; 690 if (flags & SYM_SEARCH_NEXT) 691 continue; 692 } else 693 continue; 694 } 695 if ((flags & SYM_SEARCH_OTHER) && 696 (m->data == req_obj)) 697 continue; 698 if (_dl_find_symbol_obj(m->data, name, h, flags, 699 this, &weak_sym, &weak_object)) { 700 object = m->data; 701 found = 1; 702 goto found; 703 } 704 } 705 } 706 } 707 708 found: 709 if (weak_object != NULL && found == 0) { 710 object=weak_object; 711 *this = weak_sym; 712 found = 1; 713 } 714 715 716 if (found == 0) { 717 if ((ref_sym == NULL || 718 (ELF_ST_BIND(ref_sym->st_info) != STB_WEAK)) && 719 (flags & SYM_WARNNOTFOUND)) 720 _dl_printf("%s:%s: undefined symbol '%s'\n", 721 __progname, req_obj->load_name, name); 722 return (0); 723 } 724 725 if (ref_sym != NULL && ref_sym->st_size != 0 && 726 (ref_sym->st_size != (*this)->st_size) && 727 (ELF_ST_TYPE((*this)->st_info) != STT_FUNC) ) { 728 _dl_printf("%s:%s: %s : WARNING: " 729 "symbol(%s) size mismatch, relink your program\n", 730 __progname, req_obj->load_name, object->load_name, name); 731 } 732 733 if (pobj) 734 *pobj = object; 735 736 return (object->obj_base); 737 } 738 739 void 740 _dl_debug_state(void) 741 { 742 /* Debugger stub */ 743 } 744