1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright (c) 1988 AT&T 24 * All Rights Reserved 25 * 26 * 27 * Copyright 2010 Sun Microsystems, Inc. All rights reserved. 28 * Use is subject to license terms. 29 */ 30 31 /* 32 * Symbol table management routines 33 */ 34 35 #define ELF_TARGET_AMD64 36 37 #include <stdio.h> 38 #include <string.h> 39 #include <debug.h> 40 #include "msg.h" 41 #include "_libld.h" 42 43 /* 44 * AVL tree comparator function: 45 * 46 * The primary key is the symbol name hash with a secondary key of the symbol 47 * name itself. 48 */ 49 int 50 ld_sym_avl_comp(const void *elem1, const void *elem2) 51 { 52 Sym_avlnode *sav1 = (Sym_avlnode *)elem1; 53 Sym_avlnode *sav2 = (Sym_avlnode *)elem2; 54 int res; 55 56 res = sav1->sav_hash - sav2->sav_hash; 57 58 if (res < 0) 59 return (-1); 60 if (res > 0) 61 return (1); 62 63 /* 64 * Hash is equal - now compare name 65 */ 66 res = strcmp(sav1->sav_name, sav2->sav_name); 67 if (res == 0) 68 return (0); 69 if (res > 0) 70 return (1); 71 return (-1); 72 } 73 74 /* 75 * Focal point for verifying symbol names. 76 */ 77 inline static const char * 78 string(Ofl_desc *ofl, Ifl_desc *ifl, Sym *sym, const char *strs, size_t strsize, 79 int symndx, Word shndx, Word symsecndx, const char *symsecname, 80 const char *strsecname, sd_flag_t *flags) 81 { 82 Word name = sym->st_name; 83 84 if (name) { 85 if ((ifl->ifl_flags & FLG_IF_HSTRTAB) == 0) { 86 eprintf(ofl->ofl_lml, ERR_FATAL, 87 MSG_INTL(MSG_FIL_NOSTRTABLE), ifl->ifl_name, 88 EC_WORD(symsecndx), symsecname, symndx, 89 EC_XWORD(name)); 90 return (NULL); 91 } 92 if (name >= (Word)strsize) { 93 eprintf(ofl->ofl_lml, ERR_FATAL, 94 MSG_INTL(MSG_FIL_EXCSTRTABLE), ifl->ifl_name, 95 EC_WORD(symsecndx), symsecname, symndx, 96 EC_XWORD(name), strsecname, EC_XWORD(strsize)); 97 return (NULL); 98 } 99 } 100 101 /* 102 * Determine if we're dealing with a register and if so validate it. 103 * If it's a scratch register, a fabricated name will be returned. 104 */ 105 if (ld_targ.t_ms.ms_is_regsym != NULL) { 106 const char *regname = (*ld_targ.t_ms.ms_is_regsym)(ofl, ifl, 107 sym, strs, symndx, shndx, symsecname, flags); 108 109 if (regname == (const char *)S_ERROR) { 110 return (NULL); 111 } 112 if (regname) 113 return (regname); 114 } 115 116 /* 117 * If this isn't a register, but we have a global symbol with a null 118 * name, we're not going to be able to hash this, search for it, or 119 * do anything interesting. However, we've been accepting a symbol of 120 * this kind for ages now, so give the user a warning (rather than a 121 * fatal error), just in case this instance exists somewhere in the 122 * world and hasn't, as yet, been a problem. 123 */ 124 if ((name == 0) && (ELF_ST_BIND(sym->st_info) != STB_LOCAL)) { 125 eprintf(ofl->ofl_lml, ERR_WARNING, MSG_INTL(MSG_FIL_NONAMESYM), 126 ifl->ifl_name, EC_WORD(symsecndx), symsecname, symndx, 127 EC_XWORD(name)); 128 } 129 return (strs + name); 130 } 131 132 /* 133 * For producing symbol names strings to use in error messages. 134 * If the symbol has a non-null name, then the string returned by 135 * this function is the output from demangle(), surrounded by 136 * single quotes. For null names, a descriptive string giving 137 * the symbol section and index is generated. 138 * 139 * This function uses an internal static buffer to hold the resulting 140 * string. The value returned is usable by the caller until the next 141 * call, at which point it is overwritten. 142 */ 143 static const char * 144 demangle_symname(const char *name, const char *symtab_name, Word symndx) 145 { 146 #define INIT_BUFSIZE 256 147 148 static char *buf; 149 static size_t bufsize = 0; 150 size_t len; 151 int use_name; 152 153 use_name = (name != NULL) && (*name != '\0'); 154 155 if (use_name) { 156 name = demangle(name); 157 len = strlen(name) + 2; /* Include room for quotes */ 158 } else { 159 name = MSG_ORIG(MSG_STR_EMPTY); 160 len = strlen(symtab_name) + 2 + CONV_INV_BUFSIZE; 161 } 162 len++; /* Null termination */ 163 164 /* If our buffer is too small, double it until it is big enough */ 165 if (len > bufsize) { 166 size_t new_bufsize = bufsize; 167 char *new_buf; 168 169 if (new_bufsize == 0) 170 new_bufsize = INIT_BUFSIZE; 171 while (len > new_bufsize) 172 new_bufsize *= 2; 173 if ((new_buf = libld_malloc(new_bufsize)) == NULL) 174 return (name); 175 buf = new_buf; 176 bufsize = new_bufsize; 177 } 178 179 if (use_name) { 180 (void) snprintf(buf, bufsize, MSG_ORIG(MSG_FMT_SYMNAM), name); 181 } else { 182 (void) snprintf(buf, bufsize, MSG_ORIG(MSG_FMT_NULLSYMNAM), 183 symtab_name, EC_WORD(symndx)); 184 } 185 186 return (buf); 187 188 #undef INIT_BUFSIZE 189 } 190 191 /* 192 * Shared objects can be built that define specific symbols that can not be 193 * directly bound to. These objects have a syminfo section (and an associated 194 * DF_1_NODIRECT dynamic flags entry). Scan this table looking for symbols 195 * that can't be bound to directly, and if this files symbol is presently 196 * referenced, mark it so that we don't directly bind to it. 197 */ 198 uintptr_t 199 ld_sym_nodirect(Is_desc *isp, Ifl_desc *ifl, Ofl_desc *ofl) 200 { 201 Shdr *sifshdr, *symshdr; 202 Syminfo *sifdata; 203 Sym *symdata; 204 char *strdata; 205 ulong_t cnt, _cnt; 206 207 /* 208 * Get the syminfo data, and determine the number of entries. 209 */ 210 sifshdr = isp->is_shdr; 211 sifdata = (Syminfo *)isp->is_indata->d_buf; 212 cnt = sifshdr->sh_size / sifshdr->sh_entsize; 213 214 /* 215 * Get the associated symbol table. 216 */ 217 if ((sifshdr->sh_link == 0) || (sifshdr->sh_link >= ifl->ifl_shnum)) { 218 /* 219 * Broken input file 220 */ 221 eprintf(ofl->ofl_lml, ERR_FATAL, MSG_INTL(MSG_FIL_INVSHINFO), 222 ifl->ifl_name, isp->is_name, EC_XWORD(sifshdr->sh_link)); 223 ofl->ofl_flags |= FLG_OF_FATAL; 224 return (0); 225 } 226 symshdr = ifl->ifl_isdesc[sifshdr->sh_link]->is_shdr; 227 symdata = ifl->ifl_isdesc[sifshdr->sh_link]->is_indata->d_buf; 228 229 /* 230 * Get the string table associated with the symbol table. 231 */ 232 strdata = ifl->ifl_isdesc[symshdr->sh_link]->is_indata->d_buf; 233 234 /* 235 * Traverse the syminfo data for symbols that can't be directly 236 * bound to. 237 */ 238 for (_cnt = 1, sifdata++; _cnt < cnt; _cnt++, sifdata++) { 239 Sym *sym; 240 char *str; 241 Sym_desc *sdp; 242 243 if ((sifdata->si_flags & SYMINFO_FLG_NOEXTDIRECT) == 0) 244 continue; 245 246 sym = (Sym *)(symdata + _cnt); 247 str = (char *)(strdata + sym->st_name); 248 249 if ((sdp = ld_sym_find(str, SYM_NOHASH, NULL, ofl)) != NULL) { 250 if (ifl != sdp->sd_file) 251 continue; 252 253 sdp->sd_flags &= ~FLG_SY_DIR; 254 sdp->sd_flags |= FLG_SY_NDIR; 255 } 256 } 257 return (0); 258 } 259 260 /* 261 * If, during symbol processing, it is necessary to update a local symbols 262 * contents before we have generated the symbol tables in the output image, 263 * create a new symbol structure and copy the original symbol contents. While 264 * we are processing the input files, their local symbols are part of the 265 * read-only mapped image. Commonly, these symbols are copied to the new output 266 * file image and then updated to reflect their new address and any change in 267 * attributes. However, sometimes during relocation counting, it is necessary 268 * to adjust the symbols information. This routine provides for the generation 269 * of a new symbol image so that this update can be performed. 270 * All global symbols are copied to an internal symbol table to improve locality 271 * of reference and hence performance, and thus this copying is not necessary. 272 */ 273 uintptr_t 274 ld_sym_copy(Sym_desc *sdp) 275 { 276 Sym *nsym; 277 278 if (sdp->sd_flags & FLG_SY_CLEAN) { 279 if ((nsym = libld_malloc(sizeof (Sym))) == NULL) 280 return (S_ERROR); 281 *nsym = *(sdp->sd_sym); 282 sdp->sd_sym = nsym; 283 sdp->sd_flags &= ~FLG_SY_CLEAN; 284 } 285 return (1); 286 } 287 288 /* 289 * Finds a given name in the link editors internal symbol table. If no 290 * hash value is specified it is calculated. A pointer to the located 291 * Sym_desc entry is returned, or NULL if the symbol is not found. 292 */ 293 Sym_desc * 294 ld_sym_find(const char *name, Word hash, avl_index_t *where, Ofl_desc *ofl) 295 { 296 Sym_avlnode qsav, *sav; 297 298 if (hash == SYM_NOHASH) 299 /* LINTED */ 300 hash = (Word)elf_hash((const char *)name); 301 qsav.sav_hash = hash; 302 qsav.sav_name = name; 303 304 /* 305 * Perform search for symbol in AVL tree. Note that the 'where' field 306 * is passed in from the caller. If a 'where' is present, it can be 307 * used in subsequent 'ld_sym_enter()' calls if required. 308 */ 309 sav = avl_find(&ofl->ofl_symavl, &qsav, where); 310 311 /* 312 * If symbol was not found in the avl tree, return null to show that. 313 */ 314 if (sav == NULL) 315 return (NULL); 316 317 /* 318 * Return symbol found. 319 */ 320 return (sav->sav_sdp); 321 } 322 323 /* 324 * Enter a new symbol into the link editors internal symbol table. 325 * If the symbol is from an input file, information regarding the input file 326 * and input section is also recorded. Otherwise (file == NULL) the symbol 327 * has been internally generated (ie. _etext, _edata, etc.). 328 */ 329 Sym_desc * 330 ld_sym_enter(const char *name, Sym *osym, Word hash, Ifl_desc *ifl, 331 Ofl_desc *ofl, Word ndx, Word shndx, sd_flag_t sdflags, avl_index_t *where) 332 { 333 Sym_desc *sdp; 334 Sym_aux *sap; 335 Sym_avlnode *savl; 336 char *_name; 337 Sym *nsym; 338 Half etype; 339 uchar_t vis; 340 avl_index_t _where; 341 342 /* 343 * Establish the file type. 344 */ 345 if (ifl) 346 etype = ifl->ifl_ehdr->e_type; 347 else 348 etype = ET_NONE; 349 350 ofl->ofl_entercnt++; 351 352 /* 353 * Allocate a Sym Descriptor, Auxiliary Descriptor, and a Sym AVLNode - 354 * contiguously. 355 */ 356 if ((savl = libld_calloc(S_DROUND(sizeof (Sym_avlnode)) + 357 S_DROUND(sizeof (Sym_desc)) + 358 S_DROUND(sizeof (Sym_aux)), 1)) == NULL) 359 return ((Sym_desc *)S_ERROR); 360 sdp = (Sym_desc *)((uintptr_t)savl + 361 S_DROUND(sizeof (Sym_avlnode))); 362 sap = (Sym_aux *)((uintptr_t)sdp + 363 S_DROUND(sizeof (Sym_desc))); 364 365 savl->sav_sdp = sdp; 366 sdp->sd_file = ifl; 367 sdp->sd_aux = sap; 368 savl->sav_hash = sap->sa_hash = hash; 369 370 /* 371 * Copy the symbol table entry from the input file into the internal 372 * entry and have the symbol descriptor use it. 373 */ 374 sdp->sd_sym = nsym = &sap->sa_sym; 375 *nsym = *osym; 376 sdp->sd_shndx = shndx; 377 sdp->sd_flags |= sdflags; 378 379 if ((_name = libld_malloc(strlen(name) + 1)) == NULL) 380 return ((Sym_desc *)S_ERROR); 381 savl->sav_name = sdp->sd_name = (const char *)strcpy(_name, name); 382 383 /* 384 * Enter Symbol in AVL tree. 385 */ 386 if (where == 0) { 387 /* LINTED */ 388 Sym_avlnode *_savl; 389 /* 390 * If a previous ld_sym_find() hasn't initialized 'where' do it 391 * now. 392 */ 393 where = &_where; 394 _savl = avl_find(&ofl->ofl_symavl, savl, where); 395 assert(_savl == NULL); 396 } 397 avl_insert(&ofl->ofl_symavl, savl, *where); 398 399 /* 400 * Record the section index. This is possible because the 401 * `ifl_isdesc' table is filled before we start symbol processing. 402 */ 403 if ((sdflags & FLG_SY_SPECSEC) || (nsym->st_shndx == SHN_UNDEF)) 404 sdp->sd_isc = NULL; 405 else { 406 sdp->sd_isc = ifl->ifl_isdesc[shndx]; 407 408 /* 409 * If this symbol is from a relocatable object, make sure that 410 * it is still associated with a section. For example, an 411 * unknown section type (SHT_NULL) would have been rejected on 412 * input with a warning. Here, we make the use of the symbol 413 * fatal. A symbol descriptor is still returned, so that the 414 * caller can continue processing all symbols, and hence flush 415 * out as many error conditions as possible. 416 */ 417 if ((etype == ET_REL) && (sdp->sd_isc == NULL)) { 418 eprintf(ofl->ofl_lml, ERR_FATAL, 419 MSG_INTL(MSG_SYM_INVSEC), name, ifl->ifl_name, 420 EC_XWORD(shndx)); 421 ofl->ofl_flags |= FLG_OF_FATAL; 422 return (sdp); 423 } 424 } 425 426 /* 427 * Mark any COMMON symbols as 'tentative'. 428 */ 429 if (sdflags & FLG_SY_SPECSEC) { 430 if (nsym->st_shndx == SHN_COMMON) 431 sdp->sd_flags |= FLG_SY_TENTSYM; 432 #if defined(_ELF64) 433 else if ((ld_targ.t_m.m_mach == EM_AMD64) && 434 (nsym->st_shndx == SHN_X86_64_LCOMMON)) 435 sdp->sd_flags |= FLG_SY_TENTSYM; 436 #endif 437 } 438 439 /* 440 * Establish the symbols visibility and reference. 441 */ 442 vis = ELF_ST_VISIBILITY(nsym->st_other); 443 444 if ((etype == ET_NONE) || (etype == ET_REL)) { 445 switch (vis) { 446 case STV_DEFAULT: 447 sdp->sd_flags |= FLG_SY_DEFAULT; 448 break; 449 case STV_INTERNAL: 450 case STV_HIDDEN: 451 sdp->sd_flags |= FLG_SY_HIDDEN; 452 break; 453 case STV_PROTECTED: 454 sdp->sd_flags |= FLG_SY_PROTECT; 455 break; 456 case STV_EXPORTED: 457 sdp->sd_flags |= FLG_SY_EXPORT; 458 break; 459 case STV_SINGLETON: 460 sdp->sd_flags |= (FLG_SY_SINGLE | FLG_SY_NDIR); 461 ofl->ofl_flags1 |= (FLG_OF1_NDIRECT | FLG_OF1_NGLBDIR); 462 break; 463 case STV_ELIMINATE: 464 sdp->sd_flags |= (FLG_SY_HIDDEN | FLG_SY_ELIM); 465 break; 466 default: 467 assert(vis <= STV_ELIMINATE); 468 } 469 470 sdp->sd_ref = REF_REL_NEED; 471 472 /* 473 * Under -Bnodirect, all exported interfaces that have not 474 * explicitly been defined protected or directly bound to, are 475 * tagged to prevent direct binding. 476 */ 477 if ((ofl->ofl_flags1 & FLG_OF1_ALNODIR) && 478 ((sdp->sd_flags & (FLG_SY_PROTECT | FLG_SY_DIR)) == 0) && 479 (nsym->st_shndx != SHN_UNDEF)) { 480 sdp->sd_flags |= FLG_SY_NDIR; 481 } 482 } else { 483 sdp->sd_ref = REF_DYN_SEEN; 484 485 /* 486 * If this is a protected symbol, remember this. Note, this 487 * state is different from the FLG_SY_PROTECT used to establish 488 * a symbol definitions visibility. This state is used to warn 489 * against possible copy relocations against this referenced 490 * symbol. 491 */ 492 if (vis == STV_PROTECTED) 493 sdp->sd_flags |= FLG_SY_PROT; 494 495 /* 496 * If this is a SINGLETON definition, then indicate the symbol 497 * can not be directly bound to, and retain the visibility. 498 * This visibility will be inherited by any references made to 499 * this symbol. 500 */ 501 if ((vis == STV_SINGLETON) && (nsym->st_shndx != SHN_UNDEF)) 502 sdp->sd_flags |= (FLG_SY_SINGLE | FLG_SY_NDIR); 503 504 /* 505 * If the new symbol is from a shared library and is associated 506 * with a SHT_NOBITS section then this symbol originated from a 507 * tentative symbol. 508 */ 509 if (sdp->sd_isc && 510 (sdp->sd_isc->is_shdr->sh_type == SHT_NOBITS)) 511 sdp->sd_flags |= FLG_SY_TENTSYM; 512 } 513 514 /* 515 * Reclassify any SHN_SUNW_IGNORE symbols to SHN_UNDEF so as to 516 * simplify future processing. 517 */ 518 if (nsym->st_shndx == SHN_SUNW_IGNORE) { 519 sdp->sd_shndx = shndx = SHN_UNDEF; 520 sdp->sd_flags |= (FLG_SY_REDUCED | 521 FLG_SY_HIDDEN | FLG_SY_IGNORE | FLG_SY_ELIM); 522 } 523 524 /* 525 * If this is an undefined, or common symbol from a relocatable object 526 * determine whether it is a global or weak reference (see build_osym(), 527 * where REF_DYN_NEED definitions are returned back to undefines). 528 */ 529 if ((etype == ET_REL) && 530 (ELF_ST_BIND(nsym->st_info) == STB_GLOBAL) && 531 ((nsym->st_shndx == SHN_UNDEF) || ((sdflags & FLG_SY_SPECSEC) && 532 #if defined(_ELF64) 533 ((nsym->st_shndx == SHN_COMMON) || 534 ((ld_targ.t_m.m_mach == EM_AMD64) && 535 (nsym->st_shndx == SHN_X86_64_LCOMMON)))))) 536 #else 537 /* BEGIN CSTYLED */ 538 (nsym->st_shndx == SHN_COMMON)))) 539 /* END CSTYLED */ 540 #endif 541 sdp->sd_flags |= FLG_SY_GLOBREF; 542 543 /* 544 * Record the input filename on the referenced or defined files list 545 * for possible later diagnostics. The `sa_rfile' pointer contains the 546 * name of the file that first referenced this symbol and is used to 547 * generate undefined symbol diagnostics (refer to sym_undef_entry()). 548 * Note that this entry can be overridden if a reference from a 549 * relocatable object is found after a reference from a shared object 550 * (refer to sym_override()). 551 * The `sa_dfiles' list is used to maintain the list of files that 552 * define the same symbol. This list can be used for two reasons: 553 * 554 * - To save the first definition of a symbol that is not available 555 * for this link-edit. 556 * 557 * - To save all definitions of a symbol when the -m option is in 558 * effect. This is optional as it is used to list multiple 559 * (interposed) definitions of a symbol (refer to ldmap_out()), 560 * and can be quite expensive. 561 */ 562 if (nsym->st_shndx == SHN_UNDEF) { 563 sap->sa_rfile = ifl->ifl_name; 564 } else { 565 if (sdp->sd_ref == REF_DYN_SEEN) { 566 /* 567 * A symbol is determined to be unavailable if it 568 * belongs to a version of a shared object that this 569 * user does not wish to use, or if it belongs to an 570 * implicit shared object. 571 */ 572 if (ifl->ifl_vercnt) { 573 Ver_index *vip; 574 Half vndx = ifl->ifl_versym[ndx]; 575 576 sap->sa_dverndx = vndx; 577 vip = &ifl->ifl_verndx[vndx]; 578 if (!(vip->vi_flags & FLG_VER_AVAIL)) { 579 sdp->sd_flags |= FLG_SY_NOTAVAIL; 580 sap->sa_vfile = ifl->ifl_name; 581 } 582 } 583 if (!(ifl->ifl_flags & FLG_IF_NEEDED)) 584 sdp->sd_flags |= FLG_SY_NOTAVAIL; 585 586 } else if (etype == ET_REL) { 587 /* 588 * If this symbol has been obtained from a versioned 589 * input relocatable object then the new symbol must be 590 * promoted to the versioning of the output file. 591 */ 592 if (ifl->ifl_versym) 593 ld_vers_promote(sdp, ndx, ifl, ofl); 594 } 595 596 if ((ofl->ofl_flags & FLG_OF_GENMAP) && 597 ((sdflags & FLG_SY_SPECSEC) == 0)) 598 if (aplist_append(&sap->sa_dfiles, ifl->ifl_name, 599 AL_CNT_SDP_DFILES) == NULL) 600 return ((Sym_desc *)S_ERROR); 601 } 602 603 /* 604 * Provided we're not processing a mapfile, diagnose the entered symbol. 605 * Mapfile processing requires the symbol to be updated with additional 606 * information, therefore the diagnosing of the symbol is deferred until 607 * later (see Dbg_map_symbol()). 608 */ 609 if ((ifl == NULL) || ((ifl->ifl_flags & FLG_IF_MAPFILE) == 0)) 610 DBG_CALL(Dbg_syms_entered(ofl, nsym, sdp)); 611 612 return (sdp); 613 } 614 615 /* 616 * Add a special symbol to the symbol table. Takes special symbol name with 617 * and without underscores. This routine is called, after all other symbol 618 * resolution has completed, to generate a reserved absolute symbol (the 619 * underscore version). Special symbols are updated with the appropriate 620 * values in update_osym(). If the user has already defined this symbol 621 * issue a warning and leave the symbol as is. If the non-underscore symbol 622 * is referenced then turn it into a weak alias of the underscored symbol. 623 * 624 * The bits in sdflags_u are OR'd into the flags field of the symbol for the 625 * underscored symbol. 626 * 627 * If this is a global symbol, and it hasn't explicitly been defined as being 628 * directly bound to, indicate that it can't be directly bound to. 629 * Historically, most special symbols only have meaning to the object in which 630 * they exist, however, they've always been global. To ensure compatibility 631 * with any unexpected use presently in effect, ensure these symbols don't get 632 * directly bound to. Note, that establishing this state here isn't sufficient 633 * to create a syminfo table, only if a syminfo table is being created by some 634 * other symbol directives will the nodirect binding be recorded. This ensures 635 * we don't create syminfo sections for all objects we create, as this might add 636 * unnecessary bloat to users who haven't explicitly requested extra symbol 637 * information. 638 */ 639 static uintptr_t 640 sym_add_spec(const char *name, const char *uname, Word sdaux_id, 641 sd_flag_t sdflags_u, sd_flag_t sdflags, Ofl_desc *ofl) 642 { 643 Sym_desc *sdp; 644 Sym_desc *usdp; 645 Sym *sym; 646 Word hash; 647 avl_index_t where; 648 649 /* LINTED */ 650 hash = (Word)elf_hash(uname); 651 if (usdp = ld_sym_find(uname, hash, &where, ofl)) { 652 /* 653 * If the underscore symbol exists and is undefined, or was 654 * defined in a shared library, convert it to a local symbol. 655 * Otherwise leave it as is and warn the user. 656 */ 657 if ((usdp->sd_shndx == SHN_UNDEF) || 658 (usdp->sd_ref != REF_REL_NEED)) { 659 usdp->sd_ref = REF_REL_NEED; 660 usdp->sd_shndx = usdp->sd_sym->st_shndx = SHN_ABS; 661 usdp->sd_flags |= FLG_SY_SPECSEC | sdflags_u; 662 usdp->sd_sym->st_info = 663 ELF_ST_INFO(STB_GLOBAL, STT_OBJECT); 664 usdp->sd_isc = NULL; 665 usdp->sd_sym->st_size = 0; 666 usdp->sd_sym->st_value = 0; 667 /* LINTED */ 668 usdp->sd_aux->sa_symspec = (Half)sdaux_id; 669 670 /* 671 * If a user hasn't specifically indicated that the 672 * scope of this symbol be made local, then leave it 673 * as global (ie. prevent automatic scoping). The GOT 674 * should be defined protected, whereas all other 675 * special symbols are tagged as no-direct. 676 */ 677 if (((usdp->sd_flags & FLG_SY_HIDDEN) == 0) && 678 (sdflags & FLG_SY_DEFAULT)) { 679 usdp->sd_aux->sa_overndx = VER_NDX_GLOBAL; 680 if (sdaux_id == SDAUX_ID_GOT) { 681 usdp->sd_flags &= ~FLG_SY_NDIR; 682 usdp->sd_flags |= FLG_SY_PROTECT; 683 usdp->sd_sym->st_other = STV_PROTECTED; 684 } else if ( 685 ((usdp->sd_flags & FLG_SY_DIR) == 0) && 686 ((ofl->ofl_flags & FLG_OF_SYMBOLIC) == 0)) { 687 usdp->sd_flags |= FLG_SY_NDIR; 688 } 689 } 690 usdp->sd_flags |= sdflags; 691 692 /* 693 * If the reference originated from a mapfile ensure 694 * we mark the symbol as used. 695 */ 696 if (usdp->sd_flags & FLG_SY_MAPREF) 697 usdp->sd_flags |= FLG_SY_MAPUSED; 698 699 DBG_CALL(Dbg_syms_updated(ofl, usdp, uname)); 700 } else 701 eprintf(ofl->ofl_lml, ERR_WARNING, 702 MSG_INTL(MSG_SYM_RESERVE), uname, 703 usdp->sd_file->ifl_name); 704 } else { 705 /* 706 * If the symbol does not exist create it. 707 */ 708 if ((sym = libld_calloc(sizeof (Sym), 1)) == NULL) 709 return (S_ERROR); 710 sym->st_shndx = SHN_ABS; 711 sym->st_info = ELF_ST_INFO(STB_GLOBAL, STT_OBJECT); 712 sym->st_size = 0; 713 sym->st_value = 0; 714 DBG_CALL(Dbg_syms_created(ofl->ofl_lml, uname)); 715 if ((usdp = ld_sym_enter(uname, sym, hash, (Ifl_desc *)NULL, 716 ofl, 0, SHN_ABS, (FLG_SY_SPECSEC | sdflags_u), &where)) == 717 (Sym_desc *)S_ERROR) 718 return (S_ERROR); 719 usdp->sd_ref = REF_REL_NEED; 720 /* LINTED */ 721 usdp->sd_aux->sa_symspec = (Half)sdaux_id; 722 723 usdp->sd_aux->sa_overndx = VER_NDX_GLOBAL; 724 725 if (sdaux_id == SDAUX_ID_GOT) { 726 usdp->sd_flags |= FLG_SY_PROTECT; 727 usdp->sd_sym->st_other = STV_PROTECTED; 728 } else if ((sdflags & FLG_SY_DEFAULT) && 729 ((ofl->ofl_flags & FLG_OF_SYMBOLIC) == 0)) { 730 usdp->sd_flags |= FLG_SY_NDIR; 731 } 732 usdp->sd_flags |= sdflags; 733 } 734 735 if (name && (sdp = ld_sym_find(name, SYM_NOHASH, NULL, ofl)) && 736 (sdp->sd_sym->st_shndx == SHN_UNDEF)) { 737 uchar_t bind; 738 739 /* 740 * If the non-underscore symbol exists and is undefined 741 * convert it to be a local. If the underscore has 742 * sa_symspec set (ie. it was created above) then simulate this 743 * as a weak alias. 744 */ 745 sdp->sd_ref = REF_REL_NEED; 746 sdp->sd_shndx = sdp->sd_sym->st_shndx = SHN_ABS; 747 sdp->sd_flags |= FLG_SY_SPECSEC; 748 sdp->sd_isc = NULL; 749 sdp->sd_sym->st_size = 0; 750 sdp->sd_sym->st_value = 0; 751 /* LINTED */ 752 sdp->sd_aux->sa_symspec = (Half)sdaux_id; 753 if (usdp->sd_aux->sa_symspec) { 754 usdp->sd_aux->sa_linkndx = 0; 755 sdp->sd_aux->sa_linkndx = 0; 756 bind = STB_WEAK; 757 } else 758 bind = STB_GLOBAL; 759 sdp->sd_sym->st_info = ELF_ST_INFO(bind, STT_OBJECT); 760 761 /* 762 * If a user hasn't specifically indicated the scope of this 763 * symbol be made local then leave it as global (ie. prevent 764 * automatic scoping). The GOT should be defined protected, 765 * whereas all other special symbols are tagged as no-direct. 766 */ 767 if (((sdp->sd_flags & FLG_SY_HIDDEN) == 0) && 768 (sdflags & FLG_SY_DEFAULT)) { 769 sdp->sd_aux->sa_overndx = VER_NDX_GLOBAL; 770 if (sdaux_id == SDAUX_ID_GOT) { 771 sdp->sd_flags &= ~FLG_SY_NDIR; 772 sdp->sd_flags |= FLG_SY_PROTECT; 773 sdp->sd_sym->st_other = STV_PROTECTED; 774 } else if (((sdp->sd_flags & FLG_SY_DIR) == 0) && 775 ((ofl->ofl_flags & FLG_OF_SYMBOLIC) == 0)) { 776 sdp->sd_flags |= FLG_SY_NDIR; 777 } 778 } 779 sdp->sd_flags |= sdflags; 780 781 /* 782 * If the reference originated from a mapfile ensure 783 * we mark the symbol as used. 784 */ 785 if (sdp->sd_flags & FLG_SY_MAPREF) 786 sdp->sd_flags |= FLG_SY_MAPUSED; 787 788 DBG_CALL(Dbg_syms_updated(ofl, sdp, name)); 789 } 790 return (1); 791 } 792 793 794 /* 795 * Print undefined symbols. 796 */ 797 static Boolean undef_title = TRUE; 798 799 static void 800 sym_undef_title(Ofl_desc *ofl) 801 { 802 eprintf(ofl->ofl_lml, ERR_NONE, MSG_INTL(MSG_SYM_FMT_UNDEF), 803 MSG_INTL(MSG_SYM_UNDEF_ITM_11), 804 MSG_INTL(MSG_SYM_UNDEF_ITM_21), 805 MSG_INTL(MSG_SYM_UNDEF_ITM_12), 806 MSG_INTL(MSG_SYM_UNDEF_ITM_22)); 807 808 undef_title = FALSE; 809 } 810 811 /* 812 * Undefined symbols can fall into one of four types: 813 * 814 * - the symbol is really undefined (SHN_UNDEF). 815 * 816 * - versioning has been enabled, however this symbol has not been assigned 817 * to one of the defined versions. 818 * 819 * - the symbol has been defined by an implicitly supplied library, ie. one 820 * which was encounted because it was NEEDED by another library, rather 821 * than from a command line supplied library which would become the only 822 * dependency of the output file being produced. 823 * 824 * - the symbol has been defined by a version of a shared object that is 825 * not permitted for this link-edit. 826 * 827 * In all cases the file who made the first reference to this symbol will have 828 * been recorded via the `sa_rfile' pointer. 829 */ 830 typedef enum { 831 UNDEF, NOVERSION, IMPLICIT, NOTAVAIL, 832 BNDLOCAL 833 } Type; 834 835 static const Msg format[] = { 836 MSG_SYM_UND_UNDEF, /* MSG_INTL(MSG_SYM_UND_UNDEF) */ 837 MSG_SYM_UND_NOVER, /* MSG_INTL(MSG_SYM_UND_NOVER) */ 838 MSG_SYM_UND_IMPL, /* MSG_INTL(MSG_SYM_UND_IMPL) */ 839 MSG_SYM_UND_NOTA, /* MSG_INTL(MSG_SYM_UND_NOTA) */ 840 MSG_SYM_UND_BNDLOCAL /* MSG_INTL(MSG_SYM_UND_BNDLOCAL) */ 841 }; 842 843 static void 844 sym_undef_entry(Ofl_desc *ofl, Sym_desc *sdp, Type type) 845 { 846 const char *name1, *name2, *name3; 847 Ifl_desc *ifl = sdp->sd_file; 848 Sym_aux *sap = sdp->sd_aux; 849 850 if (undef_title) 851 sym_undef_title(ofl); 852 853 switch (type) { 854 case UNDEF: 855 case BNDLOCAL: 856 name1 = sap->sa_rfile; 857 break; 858 case NOVERSION: 859 name1 = ifl->ifl_name; 860 break; 861 case IMPLICIT: 862 name1 = sap->sa_rfile; 863 name2 = ifl->ifl_name; 864 break; 865 case NOTAVAIL: 866 name1 = sap->sa_rfile; 867 name2 = sap->sa_vfile; 868 name3 = ifl->ifl_verndx[sap->sa_dverndx].vi_name; 869 break; 870 default: 871 return; 872 } 873 874 eprintf(ofl->ofl_lml, ERR_NONE, MSG_INTL(format[type]), 875 demangle(sdp->sd_name), name1, name2, name3); 876 } 877 878 /* 879 * At this point all symbol input processing has been completed, therefore 880 * complete the symbol table entries by generating any necessary internal 881 * symbols. 882 */ 883 uintptr_t 884 ld_sym_spec(Ofl_desc *ofl) 885 { 886 Sym_desc *sdp; 887 888 if (ofl->ofl_flags & FLG_OF_RELOBJ) 889 return (1); 890 891 DBG_CALL(Dbg_syms_spec_title(ofl->ofl_lml)); 892 893 if (sym_add_spec(MSG_ORIG(MSG_SYM_ETEXT), MSG_ORIG(MSG_SYM_ETEXT_U), 894 SDAUX_ID_ETEXT, 0, (FLG_SY_DEFAULT | FLG_SY_EXPDEF), 895 ofl) == S_ERROR) 896 return (S_ERROR); 897 if (sym_add_spec(MSG_ORIG(MSG_SYM_EDATA), MSG_ORIG(MSG_SYM_EDATA_U), 898 SDAUX_ID_EDATA, 0, (FLG_SY_DEFAULT | FLG_SY_EXPDEF), 899 ofl) == S_ERROR) 900 return (S_ERROR); 901 if (sym_add_spec(MSG_ORIG(MSG_SYM_END), MSG_ORIG(MSG_SYM_END_U), 902 SDAUX_ID_END, FLG_SY_DYNSORT, (FLG_SY_DEFAULT | FLG_SY_EXPDEF), 903 ofl) == S_ERROR) 904 return (S_ERROR); 905 if (sym_add_spec(MSG_ORIG(MSG_SYM_L_END), MSG_ORIG(MSG_SYM_L_END_U), 906 SDAUX_ID_END, 0, FLG_SY_HIDDEN, ofl) == S_ERROR) 907 return (S_ERROR); 908 if (sym_add_spec(MSG_ORIG(MSG_SYM_L_START), MSG_ORIG(MSG_SYM_L_START_U), 909 SDAUX_ID_START, 0, FLG_SY_HIDDEN, ofl) == S_ERROR) 910 return (S_ERROR); 911 912 /* 913 * Historically we've always produced a _DYNAMIC symbol, even for 914 * static executables (in which case its value will be 0). 915 */ 916 if (sym_add_spec(MSG_ORIG(MSG_SYM_DYNAMIC), MSG_ORIG(MSG_SYM_DYNAMIC_U), 917 SDAUX_ID_DYN, FLG_SY_DYNSORT, (FLG_SY_DEFAULT | FLG_SY_EXPDEF), 918 ofl) == S_ERROR) 919 return (S_ERROR); 920 921 if (OFL_ALLOW_DYNSYM(ofl)) 922 if (sym_add_spec(MSG_ORIG(MSG_SYM_PLKTBL), 923 MSG_ORIG(MSG_SYM_PLKTBL_U), SDAUX_ID_PLT, 924 FLG_SY_DYNSORT, (FLG_SY_DEFAULT | FLG_SY_EXPDEF), 925 ofl) == S_ERROR) 926 return (S_ERROR); 927 928 /* 929 * A GOT reference will be accompanied by the associated GOT symbol. 930 * Make sure it gets assigned the appropriate special attributes. 931 */ 932 if (((sdp = ld_sym_find(MSG_ORIG(MSG_SYM_GOFTBL_U), 933 SYM_NOHASH, NULL, ofl)) != NULL) && (sdp->sd_ref != REF_DYN_SEEN)) { 934 if (sym_add_spec(MSG_ORIG(MSG_SYM_GOFTBL), 935 MSG_ORIG(MSG_SYM_GOFTBL_U), SDAUX_ID_GOT, FLG_SY_DYNSORT, 936 (FLG_SY_DEFAULT | FLG_SY_EXPDEF), ofl) == S_ERROR) 937 return (S_ERROR); 938 } 939 940 return (1); 941 } 942 943 /* 944 * This routine checks to see if a symbols visibility needs to be reduced to 945 * either SYMBOLIC or LOCAL. This routine can be called from either 946 * reloc_init() or sym_validate(). 947 */ 948 void 949 ld_sym_adjust_vis(Sym_desc *sdp, Ofl_desc *ofl) 950 { 951 ofl_flag_t oflags = ofl->ofl_flags; 952 Sym *sym = sdp->sd_sym; 953 954 if ((sdp->sd_ref == REF_REL_NEED) && 955 (sdp->sd_sym->st_shndx != SHN_UNDEF)) { 956 /* 957 * If auto-reduction/elimination is enabled, reduce any 958 * non-versioned global symbols. This routine is called either 959 * from any initial relocation processing that references this 960 * symbol, or from the symbol validation processing. 961 * 962 * A symbol is a candidate for auto-reduction/elimination if: 963 * 964 * - the symbol wasn't explicitly defined within a mapfile 965 * (in which case all the necessary state has been applied 966 * to the symbol), or 967 * - the symbol isn't one of the family of reserved 968 * special symbols (ie. _end, _etext, etc.), or 969 * - the symbol isn't a SINGLETON, or 970 * - the symbol wasn't explicitly defined within a version 971 * definition associated with an input relocatable object. 972 * 973 * Indicate that the symbol has been reduced as it may be 974 * necessary to print these symbols later. 975 */ 976 if ((oflags & (FLG_OF_AUTOLCL | FLG_OF_AUTOELM)) && 977 ((sdp->sd_flags & MSK_SY_NOAUTO) == 0)) { 978 if ((sdp->sd_flags & FLG_SY_HIDDEN) == 0) { 979 sdp->sd_flags |= 980 (FLG_SY_REDUCED | FLG_SY_HIDDEN); 981 } 982 983 if (oflags & (FLG_OF_REDLSYM | FLG_OF_AUTOELM)) { 984 sdp->sd_flags |= FLG_SY_ELIM; 985 sym->st_other = STV_ELIMINATE | 986 (sym->st_other & ~MSK_SYM_VISIBILITY); 987 } else if (ELF_ST_VISIBILITY(sym->st_other) != 988 STV_INTERNAL) 989 sym->st_other = STV_HIDDEN | 990 (sym->st_other & ~MSK_SYM_VISIBILITY); 991 } 992 993 /* 994 * If -Bsymbolic is in effect, and the symbol hasn't explicitly 995 * been defined nodirect (via a mapfile), then bind the global 996 * symbol symbolically and assign the STV_PROTECTED visibility 997 * attribute. 998 */ 999 if ((oflags & FLG_OF_SYMBOLIC) && 1000 ((sdp->sd_flags & (FLG_SY_HIDDEN | FLG_SY_NDIR)) == 0)) { 1001 sdp->sd_flags |= FLG_SY_PROTECT; 1002 if (ELF_ST_VISIBILITY(sym->st_other) == STV_DEFAULT) 1003 sym->st_other = STV_PROTECTED | 1004 (sym->st_other & ~MSK_SYM_VISIBILITY); 1005 } 1006 } 1007 1008 /* 1009 * Indicate that this symbol has had it's visibility checked so that 1010 * we don't need to do this investigation again. 1011 */ 1012 sdp->sd_flags |= FLG_SY_VISIBLE; 1013 } 1014 1015 /* 1016 * Make sure a symbol definition is local to the object being built. 1017 */ 1018 inline static int 1019 ensure_sym_local(Ofl_desc *ofl, Sym_desc *sdp, const char *str) 1020 { 1021 if (sdp->sd_sym->st_shndx == SHN_UNDEF) { 1022 if (str) { 1023 eprintf(ofl->ofl_lml, ERR_FATAL, 1024 MSG_INTL(MSG_SYM_UNDEF), str, 1025 demangle((char *)sdp->sd_name)); 1026 } 1027 return (1); 1028 } 1029 if (sdp->sd_ref != REF_REL_NEED) { 1030 if (str) { 1031 eprintf(ofl->ofl_lml, ERR_FATAL, 1032 MSG_INTL(MSG_SYM_EXTERN), str, 1033 demangle((char *)sdp->sd_name), 1034 sdp->sd_file->ifl_name); 1035 } 1036 return (1); 1037 } 1038 1039 sdp->sd_flags |= FLG_SY_UPREQD; 1040 if (sdp->sd_isc) { 1041 sdp->sd_isc->is_flags |= FLG_IS_SECTREF; 1042 sdp->sd_isc->is_file->ifl_flags |= FLG_IF_FILEREF; 1043 } 1044 return (0); 1045 } 1046 1047 /* 1048 * Make sure all the symbol definitions required for initarray, finiarray, or 1049 * preinitarray's are local to the object being built. 1050 */ 1051 static int 1052 ensure_array_local(Ofl_desc *ofl, APlist *apl, const char *str) 1053 { 1054 Aliste idx; 1055 Sym_desc *sdp; 1056 int ret = 0; 1057 1058 for (APLIST_TRAVERSE(apl, idx, sdp)) 1059 ret += ensure_sym_local(ofl, sdp, str); 1060 1061 return (ret); 1062 } 1063 1064 /* 1065 * After all symbol table input processing has been finished, and all relocation 1066 * counting has been carried out (ie. no more symbols will be read, generated, 1067 * or modified), validate and count the relevant entries: 1068 * 1069 * - check and print any undefined symbols remaining. Note that 1070 * if a symbol has been defined by virtue of the inclusion of 1071 * an implicit shared library, it is still classed as undefined. 1072 * 1073 * - count the number of global needed symbols together with the 1074 * size of their associated name strings (if scoping has been 1075 * indicated these symbols may be reduced to locals). 1076 * 1077 * - establish the size and alignment requirements for the global 1078 * .bss section (the alignment of this section is based on the 1079 * first symbol that it will contain). 1080 */ 1081 uintptr_t 1082 ld_sym_validate(Ofl_desc *ofl) 1083 { 1084 Sym_avlnode *sav; 1085 Sym_desc *sdp; 1086 Sym *sym; 1087 ofl_flag_t oflags = ofl->ofl_flags; 1088 ofl_flag_t undef = 0, needed = 0, verdesc = 0; 1089 Xword bssalign = 0, tlsalign = 0; 1090 Boolean need_bss, need_tlsbss; 1091 Xword bsssize = 0, tlssize = 0; 1092 #if defined(_ELF64) 1093 Xword lbssalign = 0, lbsssize = 0; 1094 Boolean need_lbss; 1095 #endif 1096 int ret; 1097 int allow_ldynsym; 1098 uchar_t type; 1099 1100 DBG_CALL(Dbg_basic_validate(ofl->ofl_lml)); 1101 1102 /* 1103 * The need_XXX booleans are used to determine whether we need to 1104 * create each type of bss section. We used to create these sections 1105 * if the sum of the required sizes for each type were non-zero. 1106 * However, it is possible for a compiler to generate COMMON variables 1107 * of zero-length and this tricks that logic --- even zero-length 1108 * symbols need an output section. 1109 */ 1110 need_bss = need_tlsbss = FALSE; 1111 #if defined(_ELF64) 1112 need_lbss = FALSE; 1113 #endif 1114 1115 /* 1116 * If a symbol is undefined and this link-edit calls for no undefined 1117 * symbols to remain (this is the default case when generating an 1118 * executable but can be enforced for any object using -z defs), the 1119 * symbol is classified as undefined and a fatal error condition will 1120 * be indicated. 1121 * 1122 * If the symbol is undefined and we're creating a shared object with 1123 * the -Bsymbolic flag, then the symbol is also classified as undefined 1124 * and a warning condition will be indicated. 1125 */ 1126 if ((oflags & (FLG_OF_SHAROBJ | FLG_OF_SYMBOLIC)) == 1127 (FLG_OF_SHAROBJ | FLG_OF_SYMBOLIC)) 1128 undef = FLG_OF_WARN; 1129 if (oflags & FLG_OF_NOUNDEF) 1130 undef = FLG_OF_FATAL; 1131 1132 /* 1133 * If the symbol is referenced from an implicitly included shared object 1134 * (ie. it's not on the NEEDED list) then the symbol is also classified 1135 * as undefined and a fatal error condition will be indicated. 1136 */ 1137 if ((oflags & FLG_OF_NOUNDEF) || !(oflags & FLG_OF_SHAROBJ)) 1138 needed = FLG_OF_FATAL; 1139 1140 /* 1141 * If the output image is being versioned, then all symbol definitions 1142 * must be associated with a version. Any symbol that isn't associated 1143 * with a version is classified as undefined, and a fatal error 1144 * condition is indicated. 1145 */ 1146 if ((oflags & FLG_OF_VERDEF) && (ofl->ofl_vercnt > VER_NDX_GLOBAL)) 1147 verdesc = FLG_OF_FATAL; 1148 1149 allow_ldynsym = OFL_ALLOW_LDYNSYM(ofl); 1150 1151 if (allow_ldynsym) { 1152 /* 1153 * Normally, we disallow symbols with 0 size from appearing 1154 * in a dyn[sym|tls]sort section. However, there are some 1155 * symbols that serve special purposes that we want to exempt 1156 * from this rule. Look them up, and set their 1157 * FLG_SY_DYNSORT flag. 1158 */ 1159 static const char *special[] = { 1160 MSG_ORIG(MSG_SYM_INIT_U), /* _init */ 1161 MSG_ORIG(MSG_SYM_FINI_U), /* _fini */ 1162 MSG_ORIG(MSG_SYM_START), /* _start */ 1163 NULL 1164 }; 1165 int i; 1166 1167 for (i = 0; special[i] != NULL; i++) { 1168 if (((sdp = ld_sym_find(special[i], 1169 SYM_NOHASH, NULL, ofl)) != NULL) && 1170 (sdp->sd_sym->st_size == 0)) { 1171 if (ld_sym_copy(sdp) == S_ERROR) 1172 return (S_ERROR); 1173 sdp->sd_flags |= FLG_SY_DYNSORT; 1174 } 1175 } 1176 } 1177 1178 /* 1179 * Collect and validate the globals from the internal symbol table. 1180 */ 1181 for (sav = avl_first(&ofl->ofl_symavl); sav; 1182 sav = AVL_NEXT(&ofl->ofl_symavl, sav)) { 1183 Is_desc *isp; 1184 int undeferr = 0; 1185 uchar_t vis; 1186 1187 sdp = sav->sav_sdp; 1188 1189 /* 1190 * If undefined symbols are allowed ignore any symbols that are 1191 * not needed. 1192 */ 1193 if (!(oflags & FLG_OF_NOUNDEF) && 1194 (sdp->sd_ref == REF_DYN_SEEN)) 1195 continue; 1196 1197 /* 1198 * If the symbol originates from an external or parent mapfile 1199 * reference and hasn't been matched to a reference from a 1200 * relocatable object, ignore it. 1201 */ 1202 if ((sdp->sd_flags & (FLG_SY_EXTERN | FLG_SY_PARENT)) && 1203 ((sdp->sd_flags & FLG_SY_MAPUSED) == 0)) { 1204 sdp->sd_flags |= FLG_SY_INVALID; 1205 continue; 1206 } 1207 1208 sym = sdp->sd_sym; 1209 type = ELF_ST_TYPE(sym->st_info); 1210 1211 /* 1212 * Sanity check TLS. 1213 */ 1214 if ((type == STT_TLS) && (sym->st_size != 0) && 1215 (sym->st_shndx != SHN_UNDEF) && 1216 (sym->st_shndx != SHN_COMMON)) { 1217 Is_desc *isp = sdp->sd_isc; 1218 Ifl_desc *ifl = sdp->sd_file; 1219 1220 if ((isp == NULL) || (isp->is_shdr == NULL) || 1221 ((isp->is_shdr->sh_flags & SHF_TLS) == 0)) { 1222 eprintf(ofl->ofl_lml, ERR_FATAL, 1223 MSG_INTL(MSG_SYM_TLS), 1224 demangle(sdp->sd_name), ifl->ifl_name); 1225 ofl->ofl_flags |= FLG_OF_FATAL; 1226 continue; 1227 } 1228 } 1229 1230 if ((sdp->sd_flags & FLG_SY_VISIBLE) == 0) 1231 ld_sym_adjust_vis(sdp, ofl); 1232 1233 if ((sdp->sd_flags & FLG_SY_REDUCED) && 1234 (oflags & FLG_OF_PROCRED)) { 1235 DBG_CALL(Dbg_syms_reduce(ofl, DBG_SYM_REDUCE_GLOBAL, 1236 sdp, 0, 0)); 1237 } 1238 1239 /* 1240 * Record any STV_SINGLETON existence. 1241 */ 1242 if ((vis = ELF_ST_VISIBILITY(sym->st_other)) == STV_SINGLETON) 1243 ofl->ofl_dtflags_1 |= DF_1_SINGLETON; 1244 1245 /* 1246 * If building a shared object or executable, and this is a 1247 * non-weak UNDEF symbol with reduced visibility (STV_*), then 1248 * give a fatal error. 1249 */ 1250 if (((oflags & FLG_OF_RELOBJ) == 0) && 1251 (sym->st_shndx == SHN_UNDEF) && 1252 (ELF_ST_BIND(sym->st_info) != STB_WEAK)) { 1253 if (vis && (vis != STV_SINGLETON)) { 1254 sym_undef_entry(ofl, sdp, BNDLOCAL); 1255 ofl->ofl_flags |= FLG_OF_FATAL; 1256 continue; 1257 } 1258 } 1259 1260 /* 1261 * If this symbol is defined in a non-allocatable section, 1262 * reduce it to local symbol. 1263 */ 1264 if (((isp = sdp->sd_isc) != 0) && isp->is_shdr && 1265 ((isp->is_shdr->sh_flags & SHF_ALLOC) == 0)) { 1266 sdp->sd_flags |= (FLG_SY_REDUCED | FLG_SY_HIDDEN); 1267 } 1268 1269 /* 1270 * If this symbol originated as a SHN_SUNW_IGNORE, it will have 1271 * been processed as an SHN_UNDEF. Return the symbol to its 1272 * original index for validation, and propagation to the output 1273 * file. 1274 */ 1275 if (sdp->sd_flags & FLG_SY_IGNORE) 1276 sdp->sd_shndx = SHN_SUNW_IGNORE; 1277 1278 if (undef) { 1279 /* 1280 * If a non-weak reference remains undefined, or if a 1281 * mapfile reference is not bound to the relocatable 1282 * objects that make up the object being built, we have 1283 * a fatal error. 1284 * 1285 * The exceptions are symbols which are defined to be 1286 * found in the parent (FLG_SY_PARENT), which is really 1287 * only meaningful for direct binding, or are defined 1288 * external (FLG_SY_EXTERN) so as to suppress -zdefs 1289 * errors. 1290 * 1291 * Register symbols are always allowed to be UNDEF. 1292 * 1293 * Note that we don't include references created via -u 1294 * in the same shared object binding test. This is for 1295 * backward compatibility, in that a number of archive 1296 * makefile rules used -u to cause archive extraction. 1297 * These same rules have been cut and pasted to apply 1298 * to shared objects, and thus although the -u reference 1299 * is redundant, flagging it as fatal could cause some 1300 * build to fail. Also we have documented the use of 1301 * -u as a mechanism to cause binding to weak version 1302 * definitions, thus giving users an error condition 1303 * would be incorrect. 1304 */ 1305 if (!(sdp->sd_flags & FLG_SY_REGSYM) && 1306 ((sym->st_shndx == SHN_UNDEF) && 1307 ((ELF_ST_BIND(sym->st_info) != STB_WEAK) && 1308 ((sdp->sd_flags & 1309 (FLG_SY_PARENT | FLG_SY_EXTERN)) == 0)) || 1310 ((sdp->sd_flags & 1311 (FLG_SY_MAPREF | FLG_SY_MAPUSED | FLG_SY_HIDDEN | 1312 FLG_SY_PROTECT)) == FLG_SY_MAPREF))) { 1313 sym_undef_entry(ofl, sdp, UNDEF); 1314 ofl->ofl_flags |= undef; 1315 undeferr = 1; 1316 } 1317 1318 } else { 1319 /* 1320 * For building things like shared objects (or anything 1321 * -znodefs), undefined symbols are allowed. 1322 * 1323 * If a mapfile reference remains undefined the user 1324 * would probably like a warning at least (they've 1325 * usually mis-spelt the reference). Refer to the above 1326 * comments for discussion on -u references, which 1327 * are not tested for in the same manner. 1328 */ 1329 if ((sdp->sd_flags & 1330 (FLG_SY_MAPREF | FLG_SY_MAPUSED)) == 1331 FLG_SY_MAPREF) { 1332 sym_undef_entry(ofl, sdp, UNDEF); 1333 ofl->ofl_flags |= FLG_OF_WARN; 1334 undeferr = 1; 1335 } 1336 } 1337 1338 /* 1339 * If this symbol comes from a dependency mark the dependency 1340 * as required (-z ignore can result in unused dependencies 1341 * being dropped). If we need to record dependency versioning 1342 * information indicate what version of the needed shared object 1343 * this symbol is part of. Flag the symbol as undefined if it 1344 * has not been made available to us. 1345 */ 1346 if ((sdp->sd_ref == REF_DYN_NEED) && 1347 (!(sdp->sd_flags & FLG_SY_REFRSD))) { 1348 sdp->sd_file->ifl_flags |= FLG_IF_DEPREQD; 1349 1350 /* 1351 * Capture that we've bound to a symbol that doesn't 1352 * allow being directly bound to. 1353 */ 1354 if (sdp->sd_flags & FLG_SY_NDIR) 1355 ofl->ofl_flags1 |= FLG_OF1_NGLBDIR; 1356 1357 if (sdp->sd_file->ifl_vercnt) { 1358 int vndx; 1359 Ver_index *vip; 1360 1361 vndx = sdp->sd_aux->sa_dverndx; 1362 vip = &sdp->sd_file->ifl_verndx[vndx]; 1363 if (vip->vi_flags & FLG_VER_AVAIL) { 1364 vip->vi_flags |= FLG_VER_REFER; 1365 } else { 1366 sym_undef_entry(ofl, sdp, NOTAVAIL); 1367 ofl->ofl_flags |= FLG_OF_FATAL; 1368 continue; 1369 } 1370 } 1371 } 1372 1373 /* 1374 * Test that we do not bind to symbol supplied from an implicit 1375 * shared object. If a binding is from a weak reference it can 1376 * be ignored. 1377 */ 1378 if (needed && !undeferr && (sdp->sd_flags & FLG_SY_GLOBREF) && 1379 (sdp->sd_ref == REF_DYN_NEED) && 1380 (sdp->sd_flags & FLG_SY_NOTAVAIL)) { 1381 sym_undef_entry(ofl, sdp, IMPLICIT); 1382 ofl->ofl_flags |= needed; 1383 continue; 1384 } 1385 1386 /* 1387 * Test that a symbol isn't going to be reduced to local scope 1388 * which actually wants to bind to a shared object - if so it's 1389 * a fatal error. 1390 */ 1391 if ((sdp->sd_ref == REF_DYN_NEED) && 1392 (sdp->sd_flags & (FLG_SY_HIDDEN | FLG_SY_PROTECT))) { 1393 sym_undef_entry(ofl, sdp, BNDLOCAL); 1394 ofl->ofl_flags |= FLG_OF_FATAL; 1395 continue; 1396 } 1397 1398 /* 1399 * If the output image is to be versioned then all symbol 1400 * definitions must be associated with a version. Remove any 1401 * versioning that might be left associated with an undefined 1402 * symbol. 1403 */ 1404 if (verdesc && (sdp->sd_ref == REF_REL_NEED)) { 1405 if (sym->st_shndx == SHN_UNDEF) { 1406 if (sdp->sd_aux && sdp->sd_aux->sa_overndx) 1407 sdp->sd_aux->sa_overndx = 0; 1408 } else { 1409 if ((!(sdp->sd_flags & FLG_SY_HIDDEN)) && 1410 sdp->sd_aux && 1411 (sdp->sd_aux->sa_overndx == 0)) { 1412 sym_undef_entry(ofl, sdp, NOVERSION); 1413 ofl->ofl_flags |= verdesc; 1414 continue; 1415 } 1416 } 1417 } 1418 1419 /* 1420 * If we don't need the symbol there's no need to process it 1421 * any further. 1422 */ 1423 if (sdp->sd_ref == REF_DYN_SEEN) 1424 continue; 1425 1426 /* 1427 * Calculate the size and alignment requirements for the global 1428 * .bss and .tls sections. If we're building a relocatable 1429 * object only account for scoped COMMON symbols (these will 1430 * be converted to .bss references). 1431 * 1432 * When -z nopartial is in effect, partially initialized 1433 * symbols are directed to the special .data section 1434 * created for that purpose (ofl->ofl_isparexpn). 1435 * Otherwise, partially initialized symbols go to .bss. 1436 * 1437 * Also refer to make_mvsections() in sunwmove.c 1438 */ 1439 if ((sym->st_shndx == SHN_COMMON) && 1440 (((oflags & FLG_OF_RELOBJ) == 0) || 1441 ((sdp->sd_flags & FLG_SY_HIDDEN) && 1442 (oflags & FLG_OF_PROCRED)))) { 1443 if ((sdp->sd_move == NULL) || 1444 ((sdp->sd_flags & FLG_SY_PAREXPN) == 0)) { 1445 if (type != STT_TLS) { 1446 need_bss = TRUE; 1447 bsssize = (Xword)S_ROUND(bsssize, 1448 sym->st_value) + sym->st_size; 1449 if (sym->st_value > bssalign) 1450 bssalign = sym->st_value; 1451 } else { 1452 need_tlsbss = TRUE; 1453 tlssize = (Xword)S_ROUND(tlssize, 1454 sym->st_value) + sym->st_size; 1455 if (sym->st_value > tlsalign) 1456 tlsalign = sym->st_value; 1457 } 1458 } 1459 } 1460 1461 #if defined(_ELF64) 1462 /* 1463 * Calculate the size and alignment requirement for the global 1464 * .lbss. TLS or partially initialized symbols do not need to be 1465 * considered yet. 1466 */ 1467 if ((ld_targ.t_m.m_mach == EM_AMD64) && 1468 (sym->st_shndx == SHN_X86_64_LCOMMON)) { 1469 need_lbss = TRUE; 1470 lbsssize = (Xword)S_ROUND(lbsssize, sym->st_value) + 1471 sym->st_size; 1472 if (sym->st_value > lbssalign) 1473 lbssalign = sym->st_value; 1474 } 1475 #endif 1476 1477 /* 1478 * If a symbol was referenced via the command line 1479 * (ld -u <>, ...), then this counts as a reference against the 1480 * symbol. Mark any section that symbol is defined in. 1481 */ 1482 if (((isp = sdp->sd_isc) != 0) && 1483 (sdp->sd_flags & FLG_SY_CMDREF)) { 1484 isp->is_flags |= FLG_IS_SECTREF; 1485 isp->is_file->ifl_flags |= FLG_IF_FILEREF; 1486 } 1487 1488 /* 1489 * Update the symbol count and the associated name string size. 1490 */ 1491 if ((sdp->sd_flags & FLG_SY_HIDDEN) && 1492 (oflags & FLG_OF_PROCRED)) { 1493 /* 1494 * If any reductions are being processed, keep a count 1495 * of eliminated symbols, and if the symbol is being 1496 * reduced to local, count it's size for the .symtab. 1497 */ 1498 if (sdp->sd_flags & FLG_SY_ELIM) { 1499 ofl->ofl_elimcnt++; 1500 } else { 1501 ofl->ofl_scopecnt++; 1502 if ((((sdp->sd_flags & FLG_SY_REGSYM) == 0) || 1503 sym->st_name) && (st_insert(ofl->ofl_strtab, 1504 sdp->sd_name) == -1)) 1505 return (S_ERROR); 1506 if (allow_ldynsym && sym->st_name && 1507 ldynsym_symtype[type]) { 1508 ofl->ofl_dynscopecnt++; 1509 if (st_insert(ofl->ofl_dynstrtab, 1510 sdp->sd_name) == -1) 1511 return (S_ERROR); 1512 /* Include it in sort section? */ 1513 DYNSORT_COUNT(sdp, sym, type, ++); 1514 } 1515 } 1516 } else { 1517 ofl->ofl_globcnt++; 1518 1519 /* 1520 * Check to see if this global variable should go into 1521 * a sort section. Sort sections require a 1522 * .SUNW_ldynsym section, so, don't check unless a 1523 * .SUNW_ldynsym is allowed. 1524 */ 1525 if (allow_ldynsym) 1526 DYNSORT_COUNT(sdp, sym, type, ++); 1527 1528 /* 1529 * If global direct bindings are in effect, or this 1530 * symbol has bound to a dependency which was specified 1531 * as requiring direct bindings, and it hasn't 1532 * explicitly been defined as a non-direct binding 1533 * symbol, mark it. 1534 */ 1535 if (((ofl->ofl_dtflags_1 & DF_1_DIRECT) || (isp && 1536 (isp->is_file->ifl_flags & FLG_IF_DIRECT))) && 1537 ((sdp->sd_flags & FLG_SY_NDIR) == 0)) 1538 sdp->sd_flags |= FLG_SY_DIR; 1539 1540 /* 1541 * Insert the symbol name. 1542 */ 1543 if (((sdp->sd_flags & FLG_SY_REGSYM) == 0) || 1544 sym->st_name) { 1545 if (st_insert(ofl->ofl_strtab, 1546 sdp->sd_name) == -1) 1547 return (S_ERROR); 1548 1549 if (!(ofl->ofl_flags & FLG_OF_RELOBJ) && 1550 (st_insert(ofl->ofl_dynstrtab, 1551 sdp->sd_name) == -1)) 1552 return (S_ERROR); 1553 } 1554 1555 /* 1556 * If this section offers a global symbol - record that 1557 * fact. 1558 */ 1559 if (isp) { 1560 isp->is_flags |= FLG_IS_SECTREF; 1561 isp->is_file->ifl_flags |= FLG_IF_FILEREF; 1562 } 1563 } 1564 } 1565 1566 /* 1567 * If we've encountered a fatal error during symbol validation then 1568 * return now. 1569 */ 1570 if (ofl->ofl_flags & FLG_OF_FATAL) 1571 return (1); 1572 1573 /* 1574 * Now that symbol resolution is completed, scan any register symbols. 1575 * From now on, we're only interested in those that contribute to the 1576 * output file. 1577 */ 1578 if (ofl->ofl_regsyms) { 1579 int ndx; 1580 1581 for (ndx = 0; ndx < ofl->ofl_regsymsno; ndx++) { 1582 if ((sdp = ofl->ofl_regsyms[ndx]) == NULL) 1583 continue; 1584 if (sdp->sd_ref != REF_REL_NEED) { 1585 ofl->ofl_regsyms[ndx] = NULL; 1586 continue; 1587 } 1588 1589 ofl->ofl_regsymcnt++; 1590 if (sdp->sd_sym->st_name == 0) 1591 sdp->sd_name = MSG_ORIG(MSG_STR_EMPTY); 1592 1593 if ((sdp->sd_flags & FLG_SY_HIDDEN) || 1594 (ELF_ST_BIND(sdp->sd_sym->st_info) == STB_LOCAL)) 1595 ofl->ofl_lregsymcnt++; 1596 } 1597 } 1598 1599 /* 1600 * Generate the .bss section now that we know its size and alignment. 1601 */ 1602 if (need_bss) { 1603 if (ld_make_bss(ofl, bsssize, bssalign, 1604 ld_targ.t_id.id_bss) == S_ERROR) 1605 return (S_ERROR); 1606 } 1607 if (need_tlsbss) { 1608 if (ld_make_bss(ofl, tlssize, tlsalign, 1609 ld_targ.t_id.id_tlsbss) == S_ERROR) 1610 return (S_ERROR); 1611 } 1612 #if defined(_ELF64) 1613 if ((ld_targ.t_m.m_mach == EM_AMD64) && 1614 need_lbss && !(oflags & FLG_OF_RELOBJ)) { 1615 if (ld_make_bss(ofl, lbsssize, lbssalign, 1616 ld_targ.t_id.id_lbss) == S_ERROR) 1617 return (S_ERROR); 1618 } 1619 #endif 1620 /* 1621 * Determine what entry point symbol we need, and if found save its 1622 * symbol descriptor so that we can update the ELF header entry with the 1623 * symbols value later (see update_oehdr). Make sure the symbol is 1624 * tagged to ensure its update in case -s is in effect. Use any -e 1625 * option first, or the default entry points `_start' and `main'. 1626 */ 1627 ret = 0; 1628 if (ofl->ofl_entry) { 1629 if ((sdp = ld_sym_find(ofl->ofl_entry, SYM_NOHASH, 1630 NULL, ofl)) == NULL) { 1631 eprintf(ofl->ofl_lml, ERR_FATAL, 1632 MSG_INTL(MSG_ARG_NOENTRY), ofl->ofl_entry); 1633 ret++; 1634 } else if (ensure_sym_local(ofl, sdp, 1635 MSG_INTL(MSG_SYM_ENTRY)) != 0) { 1636 ret++; 1637 } else { 1638 ofl->ofl_entry = (void *)sdp; 1639 } 1640 } else if (((sdp = ld_sym_find(MSG_ORIG(MSG_SYM_START), 1641 SYM_NOHASH, NULL, ofl)) != NULL) && (ensure_sym_local(ofl, 1642 sdp, 0) == 0)) { 1643 ofl->ofl_entry = (void *)sdp; 1644 1645 } else if (((sdp = ld_sym_find(MSG_ORIG(MSG_SYM_MAIN), 1646 SYM_NOHASH, NULL, ofl)) != NULL) && (ensure_sym_local(ofl, 1647 sdp, 0) == 0)) { 1648 ofl->ofl_entry = (void *)sdp; 1649 } 1650 1651 /* 1652 * If ld -zdtrace=<sym> was given, then validate that the symbol is 1653 * defined within the current object being built. 1654 */ 1655 if ((sdp = ofl->ofl_dtracesym) != 0) 1656 ret += ensure_sym_local(ofl, sdp, MSG_ORIG(MSG_STR_DTRACE)); 1657 1658 /* 1659 * If any initarray, finiarray or preinitarray functions have been 1660 * requested, make sure they are defined within the current object 1661 * being built. 1662 */ 1663 if (ofl->ofl_initarray) { 1664 ret += ensure_array_local(ofl, ofl->ofl_initarray, 1665 MSG_ORIG(MSG_SYM_INITARRAY)); 1666 } 1667 if (ofl->ofl_finiarray) { 1668 ret += ensure_array_local(ofl, ofl->ofl_finiarray, 1669 MSG_ORIG(MSG_SYM_FINIARRAY)); 1670 } 1671 if (ofl->ofl_preiarray) { 1672 ret += ensure_array_local(ofl, ofl->ofl_preiarray, 1673 MSG_ORIG(MSG_SYM_PREINITARRAY)); 1674 } 1675 1676 if (ret) 1677 return (S_ERROR); 1678 1679 /* 1680 * If we're required to record any needed dependencies versioning 1681 * information calculate it now that all symbols have been validated. 1682 */ 1683 if ((oflags & (FLG_OF_VERNEED | FLG_OF_NOVERSEC)) == FLG_OF_VERNEED) 1684 return (ld_vers_check_need(ofl)); 1685 else 1686 return (1); 1687 } 1688 1689 /* 1690 * qsort(3c) comparison function. As an optimization for associating weak 1691 * symbols to their strong counterparts sort global symbols according to their 1692 * section index, address and binding. 1693 */ 1694 static int 1695 compare(const void *sdpp1, const void *sdpp2) 1696 { 1697 Sym_desc *sdp1 = *((Sym_desc **)sdpp1); 1698 Sym_desc *sdp2 = *((Sym_desc **)sdpp2); 1699 Sym *sym1, *sym2; 1700 uchar_t bind1, bind2; 1701 1702 /* 1703 * Symbol descriptors may be zero, move these to the front of the 1704 * sorted array. 1705 */ 1706 if (sdp1 == NULL) 1707 return (-1); 1708 if (sdp2 == NULL) 1709 return (1); 1710 1711 sym1 = sdp1->sd_sym; 1712 sym2 = sdp2->sd_sym; 1713 1714 /* 1715 * Compare the symbols section index. This is important when sorting 1716 * the symbol tables of relocatable objects. In this case, a symbols 1717 * value is the offset within the associated section, and thus many 1718 * symbols can have the same value, but are effectively different 1719 * addresses. 1720 */ 1721 if (sym1->st_shndx > sym2->st_shndx) 1722 return (1); 1723 if (sym1->st_shndx < sym2->st_shndx) 1724 return (-1); 1725 1726 /* 1727 * Compare the symbols value (address). 1728 */ 1729 if (sym1->st_value > sym2->st_value) 1730 return (1); 1731 if (sym1->st_value < sym2->st_value) 1732 return (-1); 1733 1734 bind1 = ELF_ST_BIND(sym1->st_info); 1735 bind2 = ELF_ST_BIND(sym2->st_info); 1736 1737 /* 1738 * If two symbols have the same address place the weak symbol before 1739 * any strong counterpart. 1740 */ 1741 if (bind1 > bind2) 1742 return (-1); 1743 if (bind1 < bind2) 1744 return (1); 1745 1746 return (0); 1747 } 1748 1749 /* 1750 * Issue a MSG_SYM_BADADDR error from ld_sym_process(). This error 1751 * is issued when a symbol address/size is not contained by the 1752 * target section. 1753 * 1754 * Such objects are at least partially corrupt, and the user would 1755 * be well advised to be skeptical of them, and to ask their compiler 1756 * supplier to fix the problem. However, a distinction needs to be 1757 * made between symbols that reference readonly text, and those that 1758 * access writable data. Other than throwing off profiling results, 1759 * the readonly section case is less serious. We have encountered 1760 * such objects in the field. In order to allow existing objects 1761 * to continue working, we issue a warning rather than a fatal error 1762 * if the symbol is against readonly text. Other cases are fatal. 1763 */ 1764 static void 1765 issue_badaddr_msg(Ifl_desc *ifl, Ofl_desc *ofl, Sym_desc *sdp, 1766 Sym *sym, Word shndx) 1767 { 1768 ofl_flag_t flag; 1769 Error err; 1770 const char *msg; 1771 1772 if ((sdp->sd_isc->is_shdr->sh_flags & (SHF_WRITE | SHF_ALLOC)) == 1773 SHF_ALLOC) { 1774 msg = MSG_INTL(MSG_SYM_BADADDR_ROTXT); 1775 flag = FLG_OF_WARN; 1776 err = ERR_WARNING; 1777 } else { 1778 msg = MSG_INTL(MSG_SYM_BADADDR); 1779 flag = FLG_OF_FATAL; 1780 err = ERR_FATAL; 1781 } 1782 1783 eprintf(ofl->ofl_lml, err, msg, demangle(sdp->sd_name), 1784 ifl->ifl_name, shndx, sdp->sd_isc->is_name, 1785 EC_XWORD(sdp->sd_isc->is_shdr->sh_size), 1786 EC_XWORD(sym->st_value), EC_XWORD(sym->st_size)); 1787 ofl->ofl_flags |= flag; 1788 } 1789 1790 1791 /* 1792 * Process the symbol table for the specified input file. At this point all 1793 * input sections from this input file have been assigned an input section 1794 * descriptor which is saved in the `ifl_isdesc' array. 1795 * 1796 * - local symbols are saved (as is) if the input file is a 1797 * relocatable object 1798 * 1799 * - global symbols are added to the linkers internal symbol 1800 * table if they are not already present, otherwise a symbol 1801 * resolution function is called upon to resolve the conflict. 1802 */ 1803 uintptr_t 1804 ld_sym_process(Is_desc *isc, Ifl_desc *ifl, Ofl_desc *ofl) 1805 { 1806 /* 1807 * This macro tests the given symbol to see if it is out of 1808 * range relative to the section it references. 1809 * 1810 * entry: 1811 * - ifl is a relative object (ET_REL) 1812 * _sdp - Symbol descriptor 1813 * _sym - Symbol 1814 * _type - Symbol type 1815 * 1816 * The following are tested: 1817 * - Symbol length is non-zero 1818 * - Symbol type is a type that references code or data 1819 * - Referenced section is not 0 (indicates an UNDEF symbol) 1820 * and is not in the range of special values above SHN_LORESERVE 1821 * (excluding SHN_XINDEX, which is OK). 1822 * - We have a valid section header for the target section 1823 * 1824 * If the above are all true, and the symbol position is not 1825 * contained by the target section, this macro evaluates to 1826 * True (1). Otherwise, False(0). 1827 */ 1828 #define SYM_LOC_BADADDR(_sdp, _sym, _type) \ 1829 (_sym->st_size && dynsymsort_symtype[_type] && \ 1830 (_sym->st_shndx != SHN_UNDEF) && \ 1831 ((_sym->st_shndx < SHN_LORESERVE) || \ 1832 (_sym->st_shndx == SHN_XINDEX)) && \ 1833 _sdp->sd_isc && _sdp->sd_isc->is_shdr && \ 1834 ((_sym->st_value + _sym->st_size) > _sdp->sd_isc->is_shdr->sh_size)) 1835 1836 Conv_inv_buf_t inv_buf; 1837 Sym *sym = (Sym *)isc->is_indata->d_buf; 1838 Word *symshndx = NULL; 1839 Shdr *shdr = isc->is_shdr; 1840 Sym_desc *sdp; 1841 size_t strsize; 1842 char *strs; 1843 uchar_t type, bind; 1844 Word ndx, hash, local, total; 1845 uchar_t osabi = ifl->ifl_ehdr->e_ident[EI_OSABI]; 1846 Half mach = ifl->ifl_ehdr->e_machine; 1847 Half etype = ifl->ifl_ehdr->e_type; 1848 int etype_rel; 1849 const char *symsecname, *strsecname; 1850 Word symsecndx; 1851 avl_index_t where; 1852 int test_gnu_hidden_bit, weak; 1853 1854 /* 1855 * Its possible that a file may contain more that one symbol table, 1856 * ie. .dynsym and .symtab in a shared library. Only process the first 1857 * table (here, we assume .dynsym comes before .symtab). 1858 */ 1859 if (ifl->ifl_symscnt) 1860 return (1); 1861 1862 if (isc->is_symshndx) 1863 symshndx = isc->is_symshndx->is_indata->d_buf; 1864 1865 DBG_CALL(Dbg_syms_process(ofl->ofl_lml, ifl)); 1866 1867 symsecndx = isc->is_scnndx; 1868 if (isc->is_name) 1869 symsecname = isc->is_name; 1870 else 1871 symsecname = MSG_ORIG(MSG_STR_EMPTY); 1872 1873 /* 1874 * From the symbol tables section header information determine which 1875 * strtab table is needed to locate the actual symbol names. 1876 */ 1877 if (ifl->ifl_flags & FLG_IF_HSTRTAB) { 1878 ndx = shdr->sh_link; 1879 if ((ndx == 0) || (ndx >= ifl->ifl_shnum)) { 1880 eprintf(ofl->ofl_lml, ERR_FATAL, 1881 MSG_INTL(MSG_FIL_INVSHLINK), ifl->ifl_name, 1882 EC_WORD(symsecndx), symsecname, EC_XWORD(ndx)); 1883 return (S_ERROR); 1884 } 1885 strsize = ifl->ifl_isdesc[ndx]->is_shdr->sh_size; 1886 strs = ifl->ifl_isdesc[ndx]->is_indata->d_buf; 1887 if (ifl->ifl_isdesc[ndx]->is_name) 1888 strsecname = ifl->ifl_isdesc[ndx]->is_name; 1889 else 1890 strsecname = MSG_ORIG(MSG_STR_EMPTY); 1891 } else { 1892 /* 1893 * There is no string table section in this input file 1894 * although there are symbols in this symbol table section. 1895 * This means that these symbols do not have names. 1896 * Currently, only scratch register symbols are allowed 1897 * not to have names. 1898 */ 1899 strsize = 0; 1900 strs = (char *)MSG_ORIG(MSG_STR_EMPTY); 1901 strsecname = MSG_ORIG(MSG_STR_EMPTY); 1902 } 1903 1904 /* 1905 * Determine the number of local symbols together with the total 1906 * number we have to process. 1907 */ 1908 total = (Word)(shdr->sh_size / shdr->sh_entsize); 1909 local = shdr->sh_info; 1910 1911 /* 1912 * Allocate a symbol table index array and a local symbol array 1913 * (global symbols are processed and added to the ofl->ofl_symbkt[] 1914 * array). If we are dealing with a relocatable object, allocate the 1915 * local symbol descriptors. If this isn't a relocatable object we 1916 * still have to process any shared object locals to determine if any 1917 * register symbols exist. Although these aren't added to the output 1918 * image, they are used as part of symbol resolution. 1919 */ 1920 if ((ifl->ifl_oldndx = libld_malloc((size_t)(total * 1921 sizeof (Sym_desc *)))) == NULL) 1922 return (S_ERROR); 1923 etype_rel = (etype == ET_REL); 1924 if (etype_rel && local) { 1925 if ((ifl->ifl_locs = 1926 libld_calloc(sizeof (Sym_desc), local)) == NULL) 1927 return (S_ERROR); 1928 /* LINTED */ 1929 ifl->ifl_locscnt = (Word)local; 1930 } 1931 ifl->ifl_symscnt = total; 1932 1933 /* 1934 * If there are local symbols to save add them to the symbol table 1935 * index array. 1936 */ 1937 if (local) { 1938 int allow_ldynsym = OFL_ALLOW_LDYNSYM(ofl); 1939 Sym_desc *last_file_sdp = NULL; 1940 int last_file_ndx = 0; 1941 1942 for (sym++, ndx = 1; ndx < local; sym++, ndx++) { 1943 sd_flag_t sdflags = FLG_SY_CLEAN; 1944 Word shndx; 1945 const char *name; 1946 Sym_desc *rsdp; 1947 int shndx_bad = 0; 1948 int symtab_enter = 1; 1949 1950 /* 1951 * Determine and validate the associated section index. 1952 */ 1953 if (symshndx && (sym->st_shndx == SHN_XINDEX)) { 1954 shndx = symshndx[ndx]; 1955 } else if ((shndx = sym->st_shndx) >= SHN_LORESERVE) { 1956 sdflags |= FLG_SY_SPECSEC; 1957 } else if (shndx > ifl->ifl_ehdr->e_shnum) { 1958 /* We need the name before we can issue error */ 1959 shndx_bad = 1; 1960 } 1961 1962 /* 1963 * Check if st_name has a valid value or not. 1964 */ 1965 if ((name = string(ofl, ifl, sym, strs, strsize, ndx, 1966 shndx, symsecndx, symsecname, strsecname, 1967 &sdflags)) == NULL) { 1968 ofl->ofl_flags |= FLG_OF_FATAL; 1969 continue; 1970 } 1971 1972 /* 1973 * Now that we have the name, if the section index 1974 * was bad, report it. 1975 */ 1976 if (shndx_bad) { 1977 eprintf(ofl->ofl_lml, ERR_WARNING, 1978 MSG_INTL(MSG_SYM_INVSHNDX), 1979 demangle_symname(name, symsecname, ndx), 1980 ifl->ifl_name, 1981 conv_sym_shndx(osabi, mach, sym->st_shndx, 1982 CONV_FMT_DECIMAL, &inv_buf)); 1983 continue; 1984 } 1985 1986 /* 1987 * If this local symbol table originates from a shared 1988 * object, then we're only interested in recording 1989 * register symbols. As local symbol descriptors aren't 1990 * allocated for shared objects, one will be allocated 1991 * to associated with the register symbol. This symbol 1992 * won't become part of the output image, but we must 1993 * process it to test for register conflicts. 1994 */ 1995 rsdp = sdp = NULL; 1996 if (sdflags & FLG_SY_REGSYM) { 1997 /* 1998 * The presence of FLG_SY_REGSYM means that 1999 * the pointers in ld_targ.t_ms are non-NULL. 2000 */ 2001 rsdp = (*ld_targ.t_ms.ms_reg_find)(sym, ofl); 2002 if (rsdp != 0) { 2003 /* 2004 * The fact that another register def- 2005 * inition has been found is fatal. 2006 * Call the verification routine to get 2007 * the error message and move on. 2008 */ 2009 (void) (*ld_targ.t_ms.ms_reg_check) 2010 (rsdp, sym, name, ifl, ofl); 2011 continue; 2012 } 2013 2014 if (etype == ET_DYN) { 2015 if ((sdp = libld_calloc( 2016 sizeof (Sym_desc), 1)) == NULL) 2017 return (S_ERROR); 2018 sdp->sd_ref = REF_DYN_SEEN; 2019 2020 /* Will not appear in output object */ 2021 symtab_enter = 0; 2022 } 2023 } else if (etype == ET_DYN) 2024 continue; 2025 2026 /* 2027 * Fill in the remaining symbol descriptor information. 2028 */ 2029 if (sdp == NULL) { 2030 sdp = &(ifl->ifl_locs[ndx]); 2031 sdp->sd_ref = REF_REL_NEED; 2032 sdp->sd_symndx = ndx; 2033 } 2034 if (rsdp == NULL) { 2035 sdp->sd_name = name; 2036 sdp->sd_sym = sym; 2037 sdp->sd_shndx = shndx; 2038 sdp->sd_flags = sdflags; 2039 sdp->sd_file = ifl; 2040 ifl->ifl_oldndx[ndx] = sdp; 2041 } 2042 2043 DBG_CALL(Dbg_syms_entry(ofl->ofl_lml, ndx, sdp)); 2044 2045 /* 2046 * Reclassify any SHN_SUNW_IGNORE symbols to SHN_UNDEF 2047 * so as to simplify future processing. 2048 */ 2049 if (sym->st_shndx == SHN_SUNW_IGNORE) { 2050 sdp->sd_shndx = shndx = SHN_UNDEF; 2051 sdp->sd_flags |= (FLG_SY_IGNORE | FLG_SY_ELIM); 2052 } 2053 2054 /* 2055 * Process any register symbols. 2056 */ 2057 if (sdp->sd_flags & FLG_SY_REGSYM) { 2058 /* 2059 * Add a diagnostic to indicate we've caught a 2060 * register symbol, as this can be useful if a 2061 * register conflict is later discovered. 2062 */ 2063 DBG_CALL(Dbg_syms_entered(ofl, sym, sdp)); 2064 2065 /* 2066 * If this register symbol hasn't already been 2067 * recorded, enter it now. 2068 * 2069 * The presence of FLG_SY_REGSYM means that 2070 * the pointers in ld_targ.t_ms are non-NULL. 2071 */ 2072 if ((rsdp == NULL) && 2073 ((*ld_targ.t_ms.ms_reg_enter)(sdp, ofl) == 2074 0)) 2075 return (S_ERROR); 2076 } 2077 2078 /* 2079 * Assign an input section. 2080 */ 2081 if ((sym->st_shndx != SHN_UNDEF) && 2082 ((sdp->sd_flags & FLG_SY_SPECSEC) == 0)) 2083 sdp->sd_isc = ifl->ifl_isdesc[shndx]; 2084 2085 /* 2086 * If this symbol falls within the range of a section 2087 * being discarded, then discard the symbol itself. 2088 * There is no reason to keep this local symbol. 2089 */ 2090 if (sdp->sd_isc && 2091 (sdp->sd_isc->is_flags & FLG_IS_DISCARD)) { 2092 sdp->sd_flags |= FLG_SY_ISDISC; 2093 DBG_CALL(Dbg_syms_discarded(ofl->ofl_lml, sdp)); 2094 continue; 2095 } 2096 2097 /* 2098 * Skip any section symbols as new versions of these 2099 * will be created. 2100 */ 2101 if ((type = ELF_ST_TYPE(sym->st_info)) == STT_SECTION) { 2102 if (sym->st_shndx == SHN_UNDEF) { 2103 eprintf(ofl->ofl_lml, ERR_WARNING, 2104 MSG_INTL(MSG_SYM_INVSHNDX), 2105 demangle_symname(name, symsecname, 2106 ndx), ifl->ifl_name, 2107 conv_sym_shndx(osabi, mach, 2108 sym->st_shndx, CONV_FMT_DECIMAL, 2109 &inv_buf)); 2110 } 2111 continue; 2112 } 2113 2114 /* 2115 * For a relocatable object, if this symbol is defined 2116 * and has non-zero length and references an address 2117 * within an associated section, then check its extents 2118 * to make sure the section boundaries encompass it. 2119 * If they don't, the ELF file is corrupt. 2120 */ 2121 if (etype_rel) { 2122 if (SYM_LOC_BADADDR(sdp, sym, type)) { 2123 issue_badaddr_msg(ifl, ofl, sdp, 2124 sym, shndx); 2125 if (ofl->ofl_flags & FLG_OF_FATAL) 2126 continue; 2127 } 2128 2129 /* 2130 * We have observed relocatable objects 2131 * containing identical adjacent STT_FILE 2132 * symbols. Discard any other than the first, 2133 * as they are all equivalent and the extras 2134 * do not add information. 2135 * 2136 * For the purpose of this test, we assume 2137 * that only the symbol type and the string 2138 * table offset (st_name) matter. 2139 */ 2140 if (type == STT_FILE) { 2141 int toss = (last_file_sdp != NULL) && 2142 ((ndx - 1) == last_file_ndx) && 2143 (sym->st_name == 2144 last_file_sdp->sd_sym->st_name); 2145 2146 last_file_sdp = sdp; 2147 last_file_ndx = ndx; 2148 if (toss) { 2149 sdp->sd_flags |= FLG_SY_INVALID; 2150 DBG_CALL(Dbg_syms_dup_discarded( 2151 ofl->ofl_lml, ndx, sdp)); 2152 continue; 2153 } 2154 } 2155 } 2156 2157 2158 /* 2159 * Sanity check for TLS 2160 */ 2161 if ((sym->st_size != 0) && ((type == STT_TLS) && 2162 (sym->st_shndx != SHN_COMMON))) { 2163 Is_desc *isp = sdp->sd_isc; 2164 2165 if ((isp == NULL) || (isp->is_shdr == NULL) || 2166 ((isp->is_shdr->sh_flags & SHF_TLS) == 0)) { 2167 eprintf(ofl->ofl_lml, ERR_FATAL, 2168 MSG_INTL(MSG_SYM_TLS), 2169 demangle(sdp->sd_name), 2170 ifl->ifl_name); 2171 ofl->ofl_flags |= FLG_OF_FATAL; 2172 continue; 2173 } 2174 } 2175 2176 /* 2177 * Carry our some basic sanity checks (these are just 2178 * some of the erroneous symbol entries we've come 2179 * across, there's probably a lot more). The symbol 2180 * will not be carried forward to the output file, which 2181 * won't be a problem unless a relocation is required 2182 * against it. 2183 */ 2184 if (((sdp->sd_flags & FLG_SY_SPECSEC) && 2185 ((sym->st_shndx == SHN_COMMON)) || 2186 ((type == STT_FILE) && 2187 (sym->st_shndx != SHN_ABS))) || 2188 (sdp->sd_isc && (sdp->sd_isc->is_osdesc == NULL))) { 2189 eprintf(ofl->ofl_lml, ERR_WARNING, 2190 MSG_INTL(MSG_SYM_INVSHNDX), 2191 demangle_symname(name, symsecname, ndx), 2192 ifl->ifl_name, 2193 conv_sym_shndx(osabi, mach, sym->st_shndx, 2194 CONV_FMT_DECIMAL, &inv_buf)); 2195 sdp->sd_isc = NULL; 2196 sdp->sd_flags |= FLG_SY_INVALID; 2197 continue; 2198 } 2199 2200 /* 2201 * As these local symbols will become part of the output 2202 * image, record their number and name string size. 2203 * Globals are counted after all input file processing 2204 * (and hence symbol resolution) is complete during 2205 * sym_validate(). 2206 */ 2207 if (!(ofl->ofl_flags & FLG_OF_REDLSYM) && 2208 symtab_enter) { 2209 ofl->ofl_locscnt++; 2210 2211 if ((((sdp->sd_flags & FLG_SY_REGSYM) == 0) || 2212 sym->st_name) && (st_insert(ofl->ofl_strtab, 2213 sdp->sd_name) == -1)) 2214 return (S_ERROR); 2215 2216 if (allow_ldynsym && sym->st_name && 2217 ldynsym_symtype[type]) { 2218 ofl->ofl_dynlocscnt++; 2219 if (st_insert(ofl->ofl_dynstrtab, 2220 sdp->sd_name) == -1) 2221 return (S_ERROR); 2222 /* Include it in sort section? */ 2223 DYNSORT_COUNT(sdp, sym, type, ++); 2224 } 2225 } 2226 } 2227 } 2228 2229 /* 2230 * The GNU ld interprets the top bit of the 16-bit Versym value 2231 * (0x8000) as the "hidden" bit. If this bit is set, the linker 2232 * is supposed to act as if that symbol does not exist. The Solaris 2233 * linker does not support this mechanism, or the model of interface 2234 * evolution that it allows, but we honor it in GNU ld produced 2235 * objects in order to interoperate with them. 2236 * 2237 * Determine if we should honor the GNU hidden bit for this file. 2238 */ 2239 test_gnu_hidden_bit = ((ifl->ifl_flags & FLG_IF_GNUVER) != 0) && 2240 (ifl->ifl_versym != NULL); 2241 2242 /* 2243 * Now scan the global symbols entering them in the internal symbol 2244 * table or resolving them as necessary. 2245 */ 2246 sym = (Sym *)isc->is_indata->d_buf; 2247 sym += local; 2248 weak = 0; 2249 /* LINTED */ 2250 for (ndx = (int)local; ndx < total; sym++, ndx++) { 2251 const char *name; 2252 sd_flag_t sdflags = 0; 2253 Word shndx; 2254 int shndx_bad = 0; 2255 Sym *nsym = sym; 2256 2257 /* 2258 * Determine and validate the associated section index. 2259 */ 2260 if (symshndx && (nsym->st_shndx == SHN_XINDEX)) { 2261 shndx = symshndx[ndx]; 2262 } else if ((shndx = nsym->st_shndx) >= SHN_LORESERVE) { 2263 sdflags |= FLG_SY_SPECSEC; 2264 } else if (shndx > ifl->ifl_ehdr->e_shnum) { 2265 /* We need the name before we can issue error */ 2266 shndx_bad = 1; 2267 } 2268 2269 /* 2270 * Check if st_name has a valid value or not. 2271 */ 2272 if ((name = string(ofl, ifl, nsym, strs, strsize, ndx, shndx, 2273 symsecndx, symsecname, strsecname, &sdflags)) == NULL) { 2274 ofl->ofl_flags |= FLG_OF_FATAL; 2275 continue; 2276 } 2277 2278 /* 2279 * Now that we have the name, if the section index 2280 * was bad, report it. 2281 */ 2282 if (shndx_bad) { 2283 eprintf(ofl->ofl_lml, ERR_WARNING, 2284 MSG_INTL(MSG_SYM_INVSHNDX), 2285 demangle_symname(name, symsecname, ndx), 2286 ifl->ifl_name, 2287 conv_sym_shndx(osabi, mach, nsym->st_shndx, 2288 CONV_FMT_DECIMAL, &inv_buf)); 2289 continue; 2290 } 2291 2292 2293 /* 2294 * Test for the GNU hidden bit, and ignore symbols that 2295 * have it set. 2296 */ 2297 if (test_gnu_hidden_bit && 2298 ((ifl->ifl_versym[ndx] & 0x8000) != 0)) 2299 continue; 2300 2301 /* 2302 * The linker itself will generate symbols for _end, _etext, 2303 * _edata, _DYNAMIC and _PROCEDURE_LINKAGE_TABLE_, so don't 2304 * bother entering these symbols from shared objects. This 2305 * results in some wasted resolution processing, which is hard 2306 * to feel, but if nothing else, pollutes diagnostic relocation 2307 * output. 2308 */ 2309 if (name[0] && (etype == ET_DYN) && (nsym->st_size == 0) && 2310 (ELF_ST_TYPE(nsym->st_info) == STT_OBJECT) && 2311 (name[0] == '_') && ((name[1] == 'e') || 2312 (name[1] == 'D') || (name[1] == 'P')) && 2313 ((strcmp(name, MSG_ORIG(MSG_SYM_ETEXT_U)) == 0) || 2314 (strcmp(name, MSG_ORIG(MSG_SYM_EDATA_U)) == 0) || 2315 (strcmp(name, MSG_ORIG(MSG_SYM_END_U)) == 0) || 2316 (strcmp(name, MSG_ORIG(MSG_SYM_DYNAMIC_U)) == 0) || 2317 (strcmp(name, MSG_ORIG(MSG_SYM_PLKTBL_U)) == 0))) { 2318 ifl->ifl_oldndx[ndx] = 0; 2319 continue; 2320 } 2321 2322 /* 2323 * The '-z wrap=XXX' option emulates the GNU ld --wrap=XXX 2324 * option. When XXX is the symbol to be wrapped: 2325 * 2326 * - An undefined reference to XXX is converted to __wrap_XXX 2327 * - An undefined reference to __real_XXX is converted to XXX 2328 * 2329 * The idea is that the user can supply a wrapper function 2330 * __wrap_XXX that does some work, and then uses the name 2331 * __real_XXX to pass the call on to the real function. The 2332 * wrapper objects are linked with the original unmodified 2333 * objects to produce a wrapped version of the output object. 2334 */ 2335 if (ofl->ofl_wrap && name[0] && (shndx == SHN_UNDEF)) { 2336 WrapSymNode wsn, *wsnp; 2337 2338 /* 2339 * If this is the __real_XXX form, advance the 2340 * pointer to reference the wrapped name. 2341 */ 2342 wsn.wsn_name = name; 2343 if ((*name == '_') && 2344 (strncmp(name, MSG_ORIG(MSG_STR_UU_REAL_U), 2345 MSG_STR_UU_REAL_U_SIZE) == 0)) 2346 wsn.wsn_name += MSG_STR_UU_REAL_U_SIZE; 2347 2348 /* 2349 * Is this symbol in the wrap AVL tree? If so, map 2350 * XXX to __wrap_XXX, and __real_XXX to XXX. Note that 2351 * wsn.wsn_name will equal the current value of name 2352 * if the __real_ prefix is not present. 2353 */ 2354 if ((wsnp = avl_find(ofl->ofl_wrap, &wsn, 0)) != NULL) { 2355 const char *old_name = name; 2356 2357 name = (wsn.wsn_name == name) ? 2358 wsnp->wsn_wrapname : wsn.wsn_name; 2359 DBG_CALL(Dbg_syms_wrap(ofl->ofl_lml, ndx, 2360 old_name, name)); 2361 } 2362 } 2363 2364 /* 2365 * Determine and validate the symbols binding. 2366 */ 2367 bind = ELF_ST_BIND(nsym->st_info); 2368 if ((bind != STB_GLOBAL) && (bind != STB_WEAK)) { 2369 eprintf(ofl->ofl_lml, ERR_WARNING, 2370 MSG_INTL(MSG_SYM_NONGLOB), 2371 demangle_symname(name, symsecname, ndx), 2372 ifl->ifl_name, 2373 conv_sym_info_bind(bind, 0, &inv_buf)); 2374 continue; 2375 } 2376 if (bind == STB_WEAK) 2377 weak++; 2378 2379 /* 2380 * If this symbol falls within the range of a section being 2381 * discarded, then discard the symbol itself. 2382 */ 2383 if (((sdflags & FLG_SY_SPECSEC) == 0) && 2384 (nsym->st_shndx != SHN_UNDEF)) { 2385 Is_desc *isp; 2386 2387 if (shndx >= ifl->ifl_shnum) { 2388 /* 2389 * Carry our some basic sanity checks 2390 * The symbol will not be carried forward to 2391 * the output file, which won't be a problem 2392 * unless a relocation is required against it. 2393 */ 2394 eprintf(ofl->ofl_lml, ERR_WARNING, 2395 MSG_INTL(MSG_SYM_INVSHNDX), 2396 demangle_symname(name, symsecname, ndx), 2397 ifl->ifl_name, 2398 conv_sym_shndx(osabi, mach, nsym->st_shndx, 2399 CONV_FMT_DECIMAL, &inv_buf)); 2400 continue; 2401 } 2402 2403 isp = ifl->ifl_isdesc[shndx]; 2404 if (isp && (isp->is_flags & FLG_IS_DISCARD)) { 2405 if ((sdp = 2406 libld_calloc(sizeof (Sym_desc), 1)) == NULL) 2407 return (S_ERROR); 2408 2409 /* 2410 * Create a dummy symbol entry so that if we 2411 * find any references to this discarded symbol 2412 * we can compensate. 2413 */ 2414 sdp->sd_name = name; 2415 sdp->sd_sym = nsym; 2416 sdp->sd_file = ifl; 2417 sdp->sd_isc = isp; 2418 sdp->sd_flags = FLG_SY_ISDISC; 2419 ifl->ifl_oldndx[ndx] = sdp; 2420 2421 DBG_CALL(Dbg_syms_discarded(ofl->ofl_lml, sdp)); 2422 continue; 2423 } 2424 } 2425 2426 /* 2427 * If the symbol does not already exist in the internal symbol 2428 * table add it, otherwise resolve the conflict. If the symbol 2429 * from this file is kept, retain its symbol table index for 2430 * possible use in associating a global alias. 2431 */ 2432 /* LINTED */ 2433 hash = (Word)elf_hash((const char *)name); 2434 if ((sdp = ld_sym_find(name, hash, &where, ofl)) == NULL) { 2435 DBG_CALL(Dbg_syms_global(ofl->ofl_lml, ndx, name)); 2436 if ((sdp = ld_sym_enter(name, nsym, hash, ifl, ofl, ndx, 2437 shndx, sdflags, &where)) == (Sym_desc *)S_ERROR) 2438 return (S_ERROR); 2439 2440 } else if (ld_sym_resolve(sdp, nsym, ifl, ofl, ndx, shndx, 2441 sdflags) == S_ERROR) 2442 return (S_ERROR); 2443 2444 /* 2445 * After we've compared a defined symbol in one shared 2446 * object, flag the symbol so we don't compare it again. 2447 */ 2448 if ((etype == ET_DYN) && (nsym->st_shndx != SHN_UNDEF) && 2449 ((sdp->sd_flags & FLG_SY_SOFOUND) == 0)) 2450 sdp->sd_flags |= FLG_SY_SOFOUND; 2451 2452 /* 2453 * If the symbol is accepted from this file retain the symbol 2454 * index for possible use in aliasing. 2455 */ 2456 if (sdp->sd_file == ifl) 2457 sdp->sd_symndx = ndx; 2458 2459 ifl->ifl_oldndx[ndx] = sdp; 2460 2461 /* 2462 * If we've accepted a register symbol, continue to validate 2463 * it. 2464 */ 2465 if (sdp->sd_flags & FLG_SY_REGSYM) { 2466 Sym_desc *rsdp; 2467 2468 /* 2469 * The presence of FLG_SY_REGSYM means that 2470 * the pointers in ld_targ.t_ms are non-NULL. 2471 */ 2472 rsdp = (*ld_targ.t_ms.ms_reg_find)(sdp->sd_sym, ofl); 2473 if (rsdp == NULL) { 2474 if ((*ld_targ.t_ms.ms_reg_enter)(sdp, ofl) == 0) 2475 return (S_ERROR); 2476 } else if (rsdp != sdp) { 2477 (void) (*ld_targ.t_ms.ms_reg_check)(rsdp, 2478 sdp->sd_sym, sdp->sd_name, ifl, ofl); 2479 } 2480 } 2481 2482 /* 2483 * For a relocatable object, if this symbol is defined 2484 * and has non-zero length and references an address 2485 * within an associated section, then check its extents 2486 * to make sure the section boundaries encompass it. 2487 * If they don't, the ELF file is corrupt. Note that this 2488 * global symbol may have come from another file to satisfy 2489 * an UNDEF symbol of the same name from this one. In that 2490 * case, we don't check it, because it was already checked 2491 * as part of its own file. 2492 */ 2493 if (etype_rel && (sdp->sd_file == ifl)) { 2494 Sym *tsym = sdp->sd_sym; 2495 2496 if (SYM_LOC_BADADDR(sdp, tsym, 2497 ELF_ST_TYPE(tsym->st_info))) { 2498 issue_badaddr_msg(ifl, ofl, sdp, 2499 tsym, tsym->st_shndx); 2500 continue; 2501 } 2502 } 2503 } 2504 2505 /* 2506 * Associate weak (alias) symbols to their non-weak counterparts by 2507 * scaning the global symbols one more time. 2508 * 2509 * This association is needed when processing the symbols from a shared 2510 * object dependency when a a weak definition satisfies a reference: 2511 * 2512 * - When building a dynamic executable, if a referenced symbol is a 2513 * data item, the symbol data is copied to the executables address 2514 * space. In this copy-relocation case, we must also reassociate 2515 * the alias symbol with its new location in the executable. 2516 * 2517 * - If the referenced symbol is a function then we may need to 2518 * promote the symbols binding from undefined weak to undefined, 2519 * otherwise the run-time linker will not generate the correct 2520 * relocation error should the symbol not be found. 2521 * 2522 * Weak alias association is also required when a local dynsym table 2523 * is being created. This table should only contain one instance of a 2524 * symbol that is associated to a given address. 2525 * 2526 * The true association between a weak/strong symbol pair is that both 2527 * symbol entries are identical, thus first we create a sorted symbol 2528 * list keyed off of the symbols section index and value. If the symbol 2529 * belongs to the same section and has the same value, then the chances 2530 * are that the rest of the symbols data is the same. This list is then 2531 * scanned for weak symbols, and if one is found then any strong 2532 * association will exist in the entries that follow. Thus we just have 2533 * to scan one (typically a single alias) or more (in the uncommon 2534 * instance of multiple weak to strong associations) entries to 2535 * determine if a match exists. 2536 */ 2537 if (weak && (OFL_ALLOW_LDYNSYM(ofl) || (etype == ET_DYN)) && 2538 (total > local)) { 2539 static Sym_desc **sort; 2540 static size_t osize = 0; 2541 size_t nsize = (total - local) * sizeof (Sym_desc *); 2542 2543 /* 2544 * As we might be processing many input files, and many symbols, 2545 * try and reuse a static sort buffer. Note, presently we're 2546 * playing the game of never freeing any buffers as there's a 2547 * belief this wastes time. 2548 */ 2549 if ((osize == 0) || (nsize > osize)) { 2550 if ((sort = libld_malloc(nsize)) == NULL) 2551 return (S_ERROR); 2552 osize = nsize; 2553 } 2554 (void) memcpy((void *)sort, &ifl->ifl_oldndx[local], nsize); 2555 2556 qsort(sort, (total - local), sizeof (Sym_desc *), compare); 2557 2558 for (ndx = 0; ndx < (total - local); ndx++) { 2559 Sym_desc *wsdp = sort[ndx]; 2560 Sym *wsym; 2561 int sndx; 2562 2563 /* 2564 * Ignore any empty symbol descriptor, or the case where 2565 * the symbol has been resolved to a different file. 2566 */ 2567 if ((wsdp == NULL) || (wsdp->sd_file != ifl)) 2568 continue; 2569 2570 wsym = wsdp->sd_sym; 2571 2572 if ((wsym->st_shndx == SHN_UNDEF) || 2573 (wsdp->sd_flags & FLG_SY_SPECSEC) || 2574 (ELF_ST_BIND(wsym->st_info) != STB_WEAK)) 2575 continue; 2576 2577 /* 2578 * We have a weak symbol, if it has a strong alias it 2579 * will have been sorted to one of the following sort 2580 * table entries. Note that we could have multiple weak 2581 * symbols aliased to one strong (if this occurs then 2582 * the strong symbol only maintains one alias back to 2583 * the last weak). 2584 */ 2585 for (sndx = ndx + 1; sndx < (total - local); sndx++) { 2586 Sym_desc *ssdp = sort[sndx]; 2587 Sym *ssym; 2588 sd_flag_t w_dynbits, s_dynbits; 2589 2590 /* 2591 * Ignore any empty symbol descriptor, or the 2592 * case where the symbol has been resolved to a 2593 * different file. 2594 */ 2595 if ((ssdp == NULL) || (ssdp->sd_file != ifl)) 2596 continue; 2597 2598 ssym = ssdp->sd_sym; 2599 2600 if (ssym->st_shndx == SHN_UNDEF) 2601 continue; 2602 2603 if ((ssym->st_shndx != wsym->st_shndx) || 2604 (ssym->st_value != wsym->st_value)) 2605 break; 2606 2607 if ((ssym->st_size != wsym->st_size) || 2608 (ssdp->sd_flags & FLG_SY_SPECSEC) || 2609 (ELF_ST_BIND(ssym->st_info) == STB_WEAK)) 2610 continue; 2611 2612 /* 2613 * If a sharable object, set link fields so 2614 * that they reference each other.` 2615 */ 2616 if (etype == ET_DYN) { 2617 ssdp->sd_aux->sa_linkndx = 2618 (Word)wsdp->sd_symndx; 2619 wsdp->sd_aux->sa_linkndx = 2620 (Word)ssdp->sd_symndx; 2621 } 2622 2623 /* 2624 * Determine which of these two symbols go into 2625 * the sort section. If a mapfile has made 2626 * explicit settings of the FLG_SY_*DYNSORT 2627 * flags for both symbols, then we do what they 2628 * say. If one has the DYNSORT flags set, we 2629 * set the NODYNSORT bit in the other. And if 2630 * neither has an explicit setting, then we 2631 * favor the weak symbol because they usually 2632 * lack the leading underscore. 2633 */ 2634 w_dynbits = wsdp->sd_flags & 2635 (FLG_SY_DYNSORT | FLG_SY_NODYNSORT); 2636 s_dynbits = ssdp->sd_flags & 2637 (FLG_SY_DYNSORT | FLG_SY_NODYNSORT); 2638 if (!(w_dynbits && s_dynbits)) { 2639 if (s_dynbits) { 2640 if (s_dynbits == FLG_SY_DYNSORT) 2641 wsdp->sd_flags |= 2642 FLG_SY_NODYNSORT; 2643 } else if (w_dynbits != 2644 FLG_SY_NODYNSORT) { 2645 ssdp->sd_flags |= 2646 FLG_SY_NODYNSORT; 2647 } 2648 } 2649 break; 2650 } 2651 } 2652 } 2653 return (1); 2654 2655 #undef SYM_LOC_BADADDR 2656 } 2657 2658 /* 2659 * Add an undefined symbol to the symbol table. The reference originates from 2660 * the location identifed by the message id (mid). These references can 2661 * originate from command line options such as -e, -u, -initarray, etc. 2662 * (identified with MSG_INTL(MSG_STR_COMMAND)), or from internally generated 2663 * TLS relocation references (identified with MSG_INTL(MSG_STR_TLSREL)). 2664 */ 2665 Sym_desc * 2666 ld_sym_add_u(const char *name, Ofl_desc *ofl, Msg mid) 2667 { 2668 Sym *sym; 2669 Ifl_desc *ifl = NULL, *_ifl; 2670 Sym_desc *sdp; 2671 Word hash; 2672 Aliste idx; 2673 avl_index_t where; 2674 const char *reference = MSG_INTL(mid); 2675 2676 /* 2677 * As an optimization, determine whether we've already generated this 2678 * reference. If the symbol doesn't already exist we'll create it. 2679 * Or if the symbol does exist from a different source, we'll resolve 2680 * the conflict. 2681 */ 2682 /* LINTED */ 2683 hash = (Word)elf_hash(name); 2684 if ((sdp = ld_sym_find(name, hash, &where, ofl)) != NULL) { 2685 if ((sdp->sd_sym->st_shndx == SHN_UNDEF) && 2686 (sdp->sd_file->ifl_name == reference)) 2687 return (sdp); 2688 } 2689 2690 /* 2691 * Determine whether a pseudo input file descriptor exists to represent 2692 * the command line, as any global symbol needs an input file descriptor 2693 * during any symbol resolution (refer to map_ifl() which provides a 2694 * similar method for adding symbols from mapfiles). 2695 */ 2696 for (APLIST_TRAVERSE(ofl->ofl_objs, idx, _ifl)) 2697 if (strcmp(_ifl->ifl_name, reference) == 0) { 2698 ifl = _ifl; 2699 break; 2700 } 2701 2702 /* 2703 * If no descriptor exists create one. 2704 */ 2705 if (ifl == NULL) { 2706 if ((ifl = libld_calloc(sizeof (Ifl_desc), 1)) == NULL) 2707 return ((Sym_desc *)S_ERROR); 2708 ifl->ifl_name = reference; 2709 ifl->ifl_flags = FLG_IF_NEEDED | FLG_IF_FILEREF; 2710 if ((ifl->ifl_ehdr = libld_calloc(sizeof (Ehdr), 1)) == NULL) 2711 return ((Sym_desc *)S_ERROR); 2712 ifl->ifl_ehdr->e_type = ET_REL; 2713 2714 if (aplist_append(&ofl->ofl_objs, ifl, AL_CNT_OFL_OBJS) == NULL) 2715 return ((Sym_desc *)S_ERROR); 2716 } 2717 2718 /* 2719 * Allocate a symbol structure and add it to the global symbol table. 2720 */ 2721 if ((sym = libld_calloc(sizeof (Sym), 1)) == NULL) 2722 return ((Sym_desc *)S_ERROR); 2723 sym->st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); 2724 sym->st_shndx = SHN_UNDEF; 2725 2726 DBG_CALL(Dbg_syms_process(ofl->ofl_lml, ifl)); 2727 if (sdp == NULL) { 2728 DBG_CALL(Dbg_syms_global(ofl->ofl_lml, 0, name)); 2729 if ((sdp = ld_sym_enter(name, sym, hash, ifl, ofl, 0, SHN_UNDEF, 2730 0, &where)) == (Sym_desc *)S_ERROR) 2731 return ((Sym_desc *)S_ERROR); 2732 } else if (ld_sym_resolve(sdp, sym, ifl, ofl, 0, 2733 SHN_UNDEF, 0) == S_ERROR) 2734 return ((Sym_desc *)S_ERROR); 2735 2736 sdp->sd_flags &= ~FLG_SY_CLEAN; 2737 sdp->sd_flags |= FLG_SY_CMDREF; 2738 2739 return (sdp); 2740 } 2741 2742 /* 2743 * STT_SECTION symbols have their st_name field set to NULL, and consequently 2744 * have no name. Generate a name suitable for diagnostic use for such a symbol. 2745 * The resulting name will be of the form: 2746 * 2747 * "XXX (section)" 2748 * 2749 * where XXX is the name of the section. 2750 * 2751 * Diagnostics for STT_SECTION symbols tend to come in clusters, 2752 * so we use a static variable to retain the last string we generate. If 2753 * another one comes along for the same section before some other section 2754 * intervenes, we will reuse the string. 2755 * 2756 * entry: 2757 * isc - Input section assocated with the symbol. 2758 * fmt - NULL, or format string to use. 2759 * 2760 * exit: 2761 * Returns the allocated string, or NULL on allocation failure. 2762 */ 2763 const const char * 2764 ld_stt_section_sym_name(Is_desc *isp) 2765 { 2766 static const char *last_fmt; 2767 static Is_desc *last_isp = NULL; 2768 static char *namestr; 2769 2770 const char *fmt; 2771 size_t len; 2772 2773 if ((isp != NULL) && (isp->is_name != NULL)) { 2774 fmt = (isp->is_flags & FLG_IS_GNSTRMRG) ? 2775 MSG_INTL(MSG_STR_SECTION_MSTR) : MSG_INTL(MSG_STR_SECTION); 2776 2777 if ((last_isp == isp) && (last_fmt == fmt)) 2778 return (namestr); 2779 2780 len = strlen(fmt) + strlen(isp->is_name) + 1; 2781 2782 if ((namestr = libld_malloc(len)) == 0) 2783 return (NULL); 2784 (void) snprintf(namestr, len, fmt, isp->is_name); 2785 2786 /* Remember for next time */ 2787 last_fmt = fmt; 2788 last_isp = isp; 2789 2790 return (namestr); 2791 } 2792 2793 return (NULL); 2794 } 2795