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 2009 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, Word *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_flags1 &= ~FLG_SY1_DIR; 254 sdp->sd_flags1 |= FLG_SY1_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_symdesc); 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, Word sdflags, Half sdflags1, 332 avl_index_t *where) 333 { 334 Sym_desc *sdp; 335 Sym_aux *sap; 336 Sym_avlnode *savl; 337 char *_name; 338 Sym *nsym; 339 Half etype; 340 uchar_t vis; 341 avl_index_t _where; 342 343 /* 344 * Establish the file type. 345 */ 346 if (ifl) 347 etype = ifl->ifl_ehdr->e_type; 348 else 349 etype = ET_NONE; 350 351 ofl->ofl_entercnt++; 352 353 /* 354 * Allocate a Sym Descriptor, Auxiliary Descriptor, and a Sym AVLNode - 355 * contiguously. 356 */ 357 if ((savl = libld_calloc(sizeof (Sym_avlnode) + sizeof (Sym_desc) + 358 sizeof (Sym_aux), 1)) == NULL) 359 return ((Sym_desc *)S_ERROR); 360 sdp = (Sym_desc *)((uintptr_t)savl + sizeof (Sym_avlnode)); 361 sap = (Sym_aux *)((uintptr_t)sdp + sizeof (Sym_desc)); 362 363 savl->sav_symdesc = sdp; 364 sdp->sd_file = ifl; 365 sdp->sd_aux = sap; 366 savl->sav_hash = sap->sa_hash = hash; 367 368 /* 369 * Copy the symbol table entry from the input file into the internal 370 * entry and have the symbol descriptor use it. 371 */ 372 sdp->sd_sym = nsym = &sap->sa_sym; 373 *nsym = *osym; 374 sdp->sd_shndx = shndx; 375 sdp->sd_flags |= sdflags; 376 sdp->sd_flags1 |= sdflags1; 377 378 if ((_name = libld_malloc(strlen(name) + 1)) == NULL) 379 return ((Sym_desc *)S_ERROR); 380 savl->sav_name = sdp->sd_name = (const char *)strcpy(_name, name); 381 382 /* 383 * Enter Symbol in AVL tree. 384 */ 385 if (where == 0) { 386 /* LINTED */ 387 Sym_avlnode *_savl; 388 /* 389 * If a previous ld_sym_find() hasn't initialized 'where' do it 390 * now. 391 */ 392 where = &_where; 393 _savl = avl_find(&ofl->ofl_symavl, savl, where); 394 assert(_savl == NULL); 395 } 396 avl_insert(&ofl->ofl_symavl, savl, *where); 397 398 /* 399 * Record the section index. This is possible because the 400 * `ifl_isdesc' table is filled before we start symbol processing. 401 */ 402 if ((sdflags & FLG_SY_SPECSEC) || (nsym->st_shndx == SHN_UNDEF)) 403 sdp->sd_isc = NULL; 404 else { 405 sdp->sd_isc = ifl->ifl_isdesc[shndx]; 406 407 /* 408 * If this symbol is from a relocatable object, make sure that 409 * it is still associated with a section. For example, an 410 * unknown section type (SHT_NULL) would have been rejected on 411 * input with a warning. Here, we make the use of the symbol 412 * fatal. A symbol descriptor is still returned, so that the 413 * caller can continue processing all symbols, and hence flush 414 * out as many error conditions as possible. 415 */ 416 if ((etype == ET_REL) && (sdp->sd_isc == NULL)) { 417 eprintf(ofl->ofl_lml, ERR_FATAL, 418 MSG_INTL(MSG_SYM_INVSEC), name, ifl->ifl_name, 419 EC_XWORD(shndx)); 420 ofl->ofl_flags |= FLG_OF_FATAL; 421 return (sdp); 422 } 423 } 424 425 /* 426 * Mark any COMMON symbols as 'tentative'. 427 */ 428 if (sdflags & FLG_SY_SPECSEC) { 429 if (nsym->st_shndx == SHN_COMMON) 430 sdp->sd_flags |= FLG_SY_TENTSYM; 431 #if defined(_ELF64) 432 else if ((ld_targ.t_m.m_mach == EM_AMD64) && 433 (nsym->st_shndx == SHN_X86_64_LCOMMON)) 434 sdp->sd_flags |= FLG_SY_TENTSYM; 435 #endif 436 } 437 438 /* 439 * Establish the symbols visibility and reference. 440 */ 441 vis = ELF_ST_VISIBILITY(nsym->st_other); 442 443 if ((etype == ET_NONE) || (etype == ET_REL)) { 444 switch (vis) { 445 case STV_DEFAULT: 446 sdp->sd_flags1 |= FLG_SY1_DEFAULT; 447 break; 448 case STV_INTERNAL: 449 case STV_HIDDEN: 450 sdp->sd_flags1 |= FLG_SY1_HIDDEN; 451 break; 452 case STV_PROTECTED: 453 sdp->sd_flags1 |= FLG_SY1_PROTECT; 454 break; 455 case STV_EXPORTED: 456 sdp->sd_flags1 |= FLG_SY1_EXPORT; 457 break; 458 case STV_SINGLETON: 459 sdp->sd_flags1 |= (FLG_SY1_SINGLE | FLG_SY1_NDIR); 460 ofl->ofl_flags1 |= (FLG_OF1_NDIRECT | FLG_OF1_NGLBDIR); 461 break; 462 case STV_ELIMINATE: 463 sdp->sd_flags1 |= (FLG_SY1_HIDDEN | FLG_SY1_ELIM); 464 break; 465 default: 466 assert(vis <= STV_ELIMINATE); 467 } 468 469 sdp->sd_ref = REF_REL_NEED; 470 471 /* 472 * Under -Bnodirect, all exported interfaces that have not 473 * explicitly been defined protected or directly bound to, are 474 * tagged to prevent direct binding. 475 */ 476 if ((ofl->ofl_flags1 & FLG_OF1_ALNODIR) && 477 ((sdp->sd_flags1 & (FLG_SY1_PROTECT | FLG_SY1_DIR)) == 0) && 478 (nsym->st_shndx != SHN_UNDEF)) { 479 sdp->sd_flags1 |= FLG_SY1_NDIR; 480 } 481 } else { 482 sdp->sd_ref = REF_DYN_SEEN; 483 484 /* 485 * Record the binding file for this symbol in the sa_bindto 486 * field. If this symbol is ever overridden by a REF_REL_NEED 487 * definition, sa_bindto is used when building a 'translator'. 488 */ 489 if (nsym->st_shndx != SHN_UNDEF) 490 sdp->sd_aux->sa_bindto = ifl; 491 492 /* 493 * If this is a protected symbol, remember this. Note, this 494 * state is different from the FLG_SY1_PROTECT used to establish 495 * a symbol definitions visibility. This state is used to warn 496 * against possible copy relocations against this referenced 497 * symbol. 498 */ 499 if (vis == STV_PROTECTED) 500 sdp->sd_flags |= FLG_SY_PROT; 501 502 /* 503 * If this is a SINGLETON definition, then indicate the symbol 504 * can not be directly bound to, and retain the visibility. 505 * This visibility will be inherited by any references made to 506 * this symbol. 507 */ 508 if ((vis == STV_SINGLETON) && (nsym->st_shndx != SHN_UNDEF)) 509 sdp->sd_flags1 |= (FLG_SY1_SINGLE | FLG_SY1_NDIR); 510 511 /* 512 * If the new symbol is from a shared library and is associated 513 * with a SHT_NOBITS section then this symbol originated from a 514 * tentative symbol. 515 */ 516 if (sdp->sd_isc && 517 (sdp->sd_isc->is_shdr->sh_type == SHT_NOBITS)) 518 sdp->sd_flags |= FLG_SY_TENTSYM; 519 } 520 521 /* 522 * Reclassify any SHN_SUNW_IGNORE symbols to SHN_UNDEF so as to 523 * simplify future processing. 524 */ 525 if (nsym->st_shndx == SHN_SUNW_IGNORE) { 526 sdp->sd_shndx = shndx = SHN_UNDEF; 527 sdp->sd_flags |= FLG_SY_REDUCED; 528 sdp->sd_flags1 |= 529 (FLG_SY1_HIDDEN | FLG_SY1_IGNORE | FLG_SY1_ELIM); 530 } 531 532 /* 533 * If this is an undefined, or common symbol from a relocatable object 534 * determine whether it is a global or weak reference (see build_osym(), 535 * where REF_DYN_NEED definitions are returned back to undefines). 536 */ 537 if ((etype == ET_REL) && 538 (ELF_ST_BIND(nsym->st_info) == STB_GLOBAL) && 539 ((nsym->st_shndx == SHN_UNDEF) || ((sdflags & FLG_SY_SPECSEC) && 540 #if defined(_ELF64) 541 ((nsym->st_shndx == SHN_COMMON) || 542 ((ld_targ.t_m.m_mach == EM_AMD64) && 543 (nsym->st_shndx == SHN_X86_64_LCOMMON)))))) 544 #else 545 /* BEGIN CSTYLED */ 546 (nsym->st_shndx == SHN_COMMON)))) 547 /* END CSTYLED */ 548 #endif 549 sdp->sd_flags |= FLG_SY_GLOBREF; 550 551 /* 552 * Record the input filename on the referenced or defined files list 553 * for possible later diagnostics. The `sa_rfile' pointer contains the 554 * name of the file that first referenced this symbol and is used to 555 * generate undefined symbol diagnostics (refer to sym_undef_entry()). 556 * Note that this entry can be overridden if a reference from a 557 * relocatable object is found after a reference from a shared object 558 * (refer to sym_override()). 559 * The `sa_dfiles' list is used to maintain the list of files that 560 * define the same symbol. This list can be used for two reasons: 561 * 562 * - To save the first definition of a symbol that is not available 563 * for this link-edit. 564 * 565 * - To save all definitions of a symbol when the -m option is in 566 * effect. This is optional as it is used to list multiple 567 * (interposed) definitions of a symbol (refer to ldmap_out()), 568 * and can be quite expensive. 569 */ 570 if (nsym->st_shndx == SHN_UNDEF) { 571 sap->sa_rfile = ifl->ifl_name; 572 } else { 573 if (sdp->sd_ref == REF_DYN_SEEN) { 574 /* 575 * A symbol is determined to be unavailable if it 576 * belongs to a version of a shared object that this 577 * user does not wish to use, or if it belongs to an 578 * implicit shared object. 579 */ 580 if (ifl->ifl_vercnt) { 581 Ver_index *vip; 582 Half vndx = ifl->ifl_versym[ndx]; 583 584 sap->sa_dverndx = vndx; 585 vip = &ifl->ifl_verndx[vndx]; 586 if (!(vip->vi_flags & FLG_VER_AVAIL)) { 587 sdp->sd_flags |= FLG_SY_NOTAVAIL; 588 sap->sa_vfile = ifl->ifl_name; 589 } 590 } 591 if (!(ifl->ifl_flags & FLG_IF_NEEDED)) 592 sdp->sd_flags |= FLG_SY_NOTAVAIL; 593 594 } else if (etype == ET_REL) { 595 /* 596 * If this symbol has been obtained from a versioned 597 * input relocatable object then the new symbol must be 598 * promoted to the versioning of the output file. 599 */ 600 if (ifl->ifl_versym) 601 ld_vers_promote(sdp, ndx, ifl, ofl); 602 } 603 604 if ((ofl->ofl_flags & FLG_OF_GENMAP) && 605 ((sdflags & FLG_SY_SPECSEC) == 0)) 606 if (aplist_append(&sap->sa_dfiles, ifl->ifl_name, 607 AL_CNT_SDP_DFILES) == NULL) 608 return ((Sym_desc *)S_ERROR); 609 } 610 611 /* 612 * Provided we're not processing a mapfile, diagnose the entered symbol. 613 * Mapfile processing requires the symbol to be updated with additional 614 * information, therefore the diagnosing of the symbol is deferred until 615 * later (see Dbg_map_symbol()). 616 */ 617 if ((ifl == NULL) || ((ifl->ifl_flags & FLG_IF_MAPFILE) == 0)) 618 DBG_CALL(Dbg_syms_entered(ofl, nsym, sdp)); 619 return (sdp); 620 } 621 622 /* 623 * Add a special symbol to the symbol table. Takes special symbol name with 624 * and without underscores. This routine is called, after all other symbol 625 * resolution has completed, to generate a reserved absolute symbol (the 626 * underscore version). Special symbols are updated with the appropriate 627 * values in update_osym(). If the user has already defined this symbol 628 * issue a warning and leave the symbol as is. If the non-underscore symbol 629 * is referenced then turn it into a weak alias of the underscored symbol. 630 * 631 * The bits in flags_u are OR'd into the flags field of the symbol 632 * for the underscored symbol. 633 * 634 * If this is a global symbol, and it hasn't explicitly been defined as being 635 * directly bound to, indicate that it can't be directly bound to. 636 * Historically, most special symbols only have meaning to the object in which 637 * they exist, however, they've always been global. To ensure compatibility 638 * with any unexpected use presently in effect, ensure these symbols don't get 639 * directly bound to. Note, that establishing this state here isn't sufficient 640 * to create a syminfo table, only if a syminfo table is being created by some 641 * other symbol directives will the nodirect binding be recorded. This ensures 642 * we don't create syminfo sections for all objects we create, as this might add 643 * unnecessary bloat to users who haven't explicitly requested extra symbol 644 * information. 645 */ 646 static uintptr_t 647 sym_add_spec(const char *name, const char *uname, Word sdaux_id, 648 Word flags_u, Half flags1, Ofl_desc *ofl) 649 { 650 Sym_desc *sdp; 651 Sym_desc *usdp; 652 Sym *sym; 653 Word hash; 654 avl_index_t where; 655 656 /* LINTED */ 657 hash = (Word)elf_hash(uname); 658 if (usdp = ld_sym_find(uname, hash, &where, ofl)) { 659 /* 660 * If the underscore symbol exists and is undefined, or was 661 * defined in a shared library, convert it to a local symbol. 662 * Otherwise leave it as is and warn the user. 663 */ 664 if ((usdp->sd_shndx == SHN_UNDEF) || 665 (usdp->sd_ref != REF_REL_NEED)) { 666 usdp->sd_ref = REF_REL_NEED; 667 usdp->sd_shndx = usdp->sd_sym->st_shndx = SHN_ABS; 668 usdp->sd_flags |= FLG_SY_SPECSEC | flags_u; 669 usdp->sd_sym->st_info = 670 ELF_ST_INFO(STB_GLOBAL, STT_OBJECT); 671 usdp->sd_isc = NULL; 672 usdp->sd_sym->st_size = 0; 673 usdp->sd_sym->st_value = 0; 674 /* LINTED */ 675 usdp->sd_aux->sa_symspec = (Half)sdaux_id; 676 677 /* 678 * If a user hasn't specifically indicated that the 679 * scope of this symbol be made local, then leave it 680 * as global (ie. prevent automatic scoping). The GOT 681 * should be defined protected, whereas all other 682 * special symbols are tagged as no-direct. 683 */ 684 if (((usdp->sd_flags1 & FLG_SY1_HIDDEN) == 0) && 685 (flags1 & FLG_SY1_DEFAULT)) { 686 usdp->sd_aux->sa_overndx = VER_NDX_GLOBAL; 687 if (sdaux_id == SDAUX_ID_GOT) { 688 usdp->sd_flags1 &= ~FLG_SY1_NDIR; 689 usdp->sd_flags1 |= FLG_SY1_PROTECT; 690 usdp->sd_sym->st_other = STV_PROTECTED; 691 } else if ( 692 ((usdp->sd_flags1 & FLG_SY1_DIR) == 0) && 693 ((ofl->ofl_flags & FLG_OF_SYMBOLIC) == 0)) { 694 usdp->sd_flags1 |= FLG_SY1_NDIR; 695 } 696 } 697 usdp->sd_flags1 |= flags1; 698 699 /* 700 * If the reference originated from a mapfile ensure 701 * we mark the symbol as used. 702 */ 703 if (usdp->sd_flags & FLG_SY_MAPREF) 704 usdp->sd_flags |= FLG_SY_MAPUSED; 705 706 DBG_CALL(Dbg_syms_updated(ofl, usdp, uname)); 707 } else 708 eprintf(ofl->ofl_lml, ERR_WARNING, 709 MSG_INTL(MSG_SYM_RESERVE), uname, 710 usdp->sd_file->ifl_name); 711 } else { 712 /* 713 * If the symbol does not exist create it. 714 */ 715 if ((sym = libld_calloc(sizeof (Sym), 1)) == NULL) 716 return (S_ERROR); 717 sym->st_shndx = SHN_ABS; 718 sym->st_info = ELF_ST_INFO(STB_GLOBAL, STT_OBJECT); 719 sym->st_size = 0; 720 sym->st_value = 0; 721 DBG_CALL(Dbg_syms_created(ofl->ofl_lml, uname)); 722 if ((usdp = ld_sym_enter(uname, sym, hash, (Ifl_desc *)NULL, 723 ofl, 0, SHN_ABS, FLG_SY_SPECSEC | flags_u, 0, &where)) == 724 (Sym_desc *)S_ERROR) 725 return (S_ERROR); 726 usdp->sd_ref = REF_REL_NEED; 727 /* LINTED */ 728 usdp->sd_aux->sa_symspec = (Half)sdaux_id; 729 730 usdp->sd_aux->sa_overndx = VER_NDX_GLOBAL; 731 732 if (sdaux_id == SDAUX_ID_GOT) { 733 usdp->sd_flags1 |= FLG_SY1_PROTECT; 734 usdp->sd_sym->st_other = STV_PROTECTED; 735 } else if ((flags1 & FLG_SY1_DEFAULT) && 736 ((ofl->ofl_flags & FLG_OF_SYMBOLIC) == 0)) { 737 usdp->sd_flags1 |= FLG_SY1_NDIR; 738 } 739 usdp->sd_flags1 |= flags1; 740 } 741 742 if (name && (sdp = ld_sym_find(name, SYM_NOHASH, NULL, ofl)) && 743 (sdp->sd_sym->st_shndx == SHN_UNDEF)) { 744 uchar_t bind; 745 746 /* 747 * If the non-underscore symbol exists and is undefined 748 * convert it to be a local. If the underscore has 749 * sa_symspec set (ie. it was created above) then simulate this 750 * as a weak alias. 751 */ 752 sdp->sd_ref = REF_REL_NEED; 753 sdp->sd_shndx = sdp->sd_sym->st_shndx = SHN_ABS; 754 sdp->sd_flags |= FLG_SY_SPECSEC; 755 sdp->sd_isc = NULL; 756 sdp->sd_sym->st_size = 0; 757 sdp->sd_sym->st_value = 0; 758 /* LINTED */ 759 sdp->sd_aux->sa_symspec = (Half)sdaux_id; 760 if (usdp->sd_aux->sa_symspec) { 761 usdp->sd_aux->sa_linkndx = 0; 762 sdp->sd_aux->sa_linkndx = 0; 763 bind = STB_WEAK; 764 } else 765 bind = STB_GLOBAL; 766 sdp->sd_sym->st_info = ELF_ST_INFO(bind, STT_OBJECT); 767 768 /* 769 * If a user hasn't specifically indicated the scope of this 770 * symbol be made local then leave it as global (ie. prevent 771 * automatic scoping). The GOT should be defined protected, 772 * whereas all other special symbols are tagged as no-direct. 773 */ 774 if (((sdp->sd_flags1 & FLG_SY1_HIDDEN) == 0) && 775 (flags1 & FLG_SY1_DEFAULT)) { 776 sdp->sd_aux->sa_overndx = VER_NDX_GLOBAL; 777 if (sdaux_id == SDAUX_ID_GOT) { 778 sdp->sd_flags1 &= ~FLG_SY1_NDIR; 779 sdp->sd_flags1 |= FLG_SY1_PROTECT; 780 sdp->sd_sym->st_other = STV_PROTECTED; 781 } else if (((sdp->sd_flags1 & FLG_SY1_DIR) == 0) && 782 ((ofl->ofl_flags & FLG_OF_SYMBOLIC) == 0)) { 783 sdp->sd_flags1 |= FLG_SY1_NDIR; 784 } 785 } 786 sdp->sd_flags1 |= flags1; 787 788 /* 789 * If the reference originated from a mapfile ensure 790 * we mark the symbol as used. 791 */ 792 if (sdp->sd_flags & FLG_SY_MAPREF) 793 sdp->sd_flags |= FLG_SY_MAPUSED; 794 795 DBG_CALL(Dbg_syms_updated(ofl, sdp, name)); 796 } 797 return (1); 798 } 799 800 801 /* 802 * Print undefined symbols. 803 */ 804 static Boolean undef_title = TRUE; 805 806 static void 807 sym_undef_title(Ofl_desc *ofl) 808 { 809 eprintf(ofl->ofl_lml, ERR_NONE, MSG_INTL(MSG_SYM_FMT_UNDEF), 810 MSG_INTL(MSG_SYM_UNDEF_ITM_11), 811 MSG_INTL(MSG_SYM_UNDEF_ITM_21), 812 MSG_INTL(MSG_SYM_UNDEF_ITM_12), 813 MSG_INTL(MSG_SYM_UNDEF_ITM_22)); 814 815 undef_title = FALSE; 816 } 817 818 /* 819 * Undefined symbols can fall into one of four types: 820 * 821 * - the symbol is really undefined (SHN_UNDEF). 822 * 823 * - versioning has been enabled, however this symbol has not been assigned 824 * to one of the defined versions. 825 * 826 * - the symbol has been defined by an implicitly supplied library, ie. one 827 * which was encounted because it was NEEDED by another library, rather 828 * than from a command line supplied library which would become the only 829 * dependency of the output file being produced. 830 * 831 * - the symbol has been defined by a version of a shared object that is 832 * not permitted for this link-edit. 833 * 834 * In all cases the file who made the first reference to this symbol will have 835 * been recorded via the `sa_rfile' pointer. 836 */ 837 typedef enum { 838 UNDEF, NOVERSION, IMPLICIT, NOTAVAIL, 839 BNDLOCAL 840 } Type; 841 842 static const Msg format[] = { 843 MSG_SYM_UND_UNDEF, /* MSG_INTL(MSG_SYM_UND_UNDEF) */ 844 MSG_SYM_UND_NOVER, /* MSG_INTL(MSG_SYM_UND_NOVER) */ 845 MSG_SYM_UND_IMPL, /* MSG_INTL(MSG_SYM_UND_IMPL) */ 846 MSG_SYM_UND_NOTA, /* MSG_INTL(MSG_SYM_UND_NOTA) */ 847 MSG_SYM_UND_BNDLOCAL /* MSG_INTL(MSG_SYM_UND_BNDLOCAL) */ 848 }; 849 850 static void 851 sym_undef_entry(Ofl_desc *ofl, Sym_desc *sdp, Type type) 852 { 853 const char *name1, *name2, *name3; 854 Ifl_desc *ifl = sdp->sd_file; 855 Sym_aux *sap = sdp->sd_aux; 856 857 if (undef_title) 858 sym_undef_title(ofl); 859 860 switch (type) { 861 case UNDEF: 862 case BNDLOCAL: 863 name1 = sap->sa_rfile; 864 break; 865 case NOVERSION: 866 name1 = ifl->ifl_name; 867 break; 868 case IMPLICIT: 869 name1 = sap->sa_rfile; 870 name2 = ifl->ifl_name; 871 break; 872 case NOTAVAIL: 873 name1 = sap->sa_rfile; 874 name2 = sap->sa_vfile; 875 name3 = ifl->ifl_verndx[sap->sa_dverndx].vi_name; 876 break; 877 default: 878 return; 879 } 880 881 eprintf(ofl->ofl_lml, ERR_NONE, MSG_INTL(format[type]), 882 demangle(sdp->sd_name), name1, name2, name3); 883 } 884 885 /* 886 * At this point all symbol input processing has been completed, therefore 887 * complete the symbol table entries by generating any necessary internal 888 * symbols. 889 */ 890 uintptr_t 891 ld_sym_spec(Ofl_desc *ofl) 892 { 893 Sym_desc *sdp; 894 895 if (ofl->ofl_flags & FLG_OF_RELOBJ) 896 return (1); 897 898 DBG_CALL(Dbg_syms_spec_title(ofl->ofl_lml)); 899 900 if (sym_add_spec(MSG_ORIG(MSG_SYM_ETEXT), MSG_ORIG(MSG_SYM_ETEXT_U), 901 SDAUX_ID_ETEXT, 0, (FLG_SY1_DEFAULT | FLG_SY1_EXPDEF), 902 ofl) == S_ERROR) 903 return (S_ERROR); 904 if (sym_add_spec(MSG_ORIG(MSG_SYM_EDATA), MSG_ORIG(MSG_SYM_EDATA_U), 905 SDAUX_ID_EDATA, 0, (FLG_SY1_DEFAULT | FLG_SY1_EXPDEF), 906 ofl) == S_ERROR) 907 return (S_ERROR); 908 if (sym_add_spec(MSG_ORIG(MSG_SYM_END), MSG_ORIG(MSG_SYM_END_U), 909 SDAUX_ID_END, FLG_SY_DYNSORT, (FLG_SY1_DEFAULT | FLG_SY1_EXPDEF), 910 ofl) == S_ERROR) 911 return (S_ERROR); 912 if (sym_add_spec(MSG_ORIG(MSG_SYM_L_END), MSG_ORIG(MSG_SYM_L_END_U), 913 SDAUX_ID_END, 0, FLG_SY1_HIDDEN, ofl) == S_ERROR) 914 return (S_ERROR); 915 if (sym_add_spec(MSG_ORIG(MSG_SYM_L_START), MSG_ORIG(MSG_SYM_L_START_U), 916 SDAUX_ID_START, 0, FLG_SY1_HIDDEN, ofl) == S_ERROR) 917 return (S_ERROR); 918 919 /* 920 * Historically we've always produced a _DYNAMIC symbol, even for 921 * static executables (in which case its value will be 0). 922 */ 923 if (sym_add_spec(MSG_ORIG(MSG_SYM_DYNAMIC), MSG_ORIG(MSG_SYM_DYNAMIC_U), 924 SDAUX_ID_DYN, FLG_SY_DYNSORT, (FLG_SY1_DEFAULT | FLG_SY1_EXPDEF), 925 ofl) == S_ERROR) 926 return (S_ERROR); 927 928 if (OFL_ALLOW_DYNSYM(ofl)) 929 if (sym_add_spec(MSG_ORIG(MSG_SYM_PLKTBL), 930 MSG_ORIG(MSG_SYM_PLKTBL_U), SDAUX_ID_PLT, 931 FLG_SY_DYNSORT, (FLG_SY1_DEFAULT | FLG_SY1_EXPDEF), 932 ofl) == S_ERROR) 933 return (S_ERROR); 934 935 /* 936 * A GOT reference will be accompanied by the associated GOT symbol. 937 * Make sure it gets assigned the appropriate special attributes. 938 */ 939 if (((sdp = ld_sym_find(MSG_ORIG(MSG_SYM_GOFTBL_U), 940 SYM_NOHASH, NULL, ofl)) != 0) && (sdp->sd_ref != REF_DYN_SEEN)) { 941 if (sym_add_spec(MSG_ORIG(MSG_SYM_GOFTBL), 942 MSG_ORIG(MSG_SYM_GOFTBL_U), SDAUX_ID_GOT, FLG_SY_DYNSORT, 943 (FLG_SY1_DEFAULT | FLG_SY1_EXPDEF), ofl) == S_ERROR) 944 return (S_ERROR); 945 } 946 947 return (1); 948 } 949 950 /* 951 * This routine checks to see if a symbols visibility needs to be reduced to 952 * either SYMBOLIC or LOCAL. This routine can be called from either 953 * reloc_init() or sym_validate(). 954 */ 955 void 956 ld_sym_adjust_vis(Sym_desc *sdp, Ofl_desc *ofl) 957 { 958 ofl_flag_t oflags = ofl->ofl_flags; 959 Sym *sym = sdp->sd_sym; 960 961 if ((sdp->sd_ref == REF_REL_NEED) && 962 (sdp->sd_sym->st_shndx != SHN_UNDEF)) { 963 /* 964 * If auto-reduction/elimination is enabled, reduce any 965 * non-versioned global symbols. This routine is called either 966 * from any initial relocation processing that references this 967 * symbol, or from the symbol validation processing. 968 * 969 * A symbol is a candidate for auto-reduction/elimination if: 970 * 971 * - the symbol wasn't explicitly defined within a mapfile 972 * (in which case all the necessary state has been applied 973 * to the symbol), or 974 * - the symbol isn't one of the family of reserved 975 * special symbols (ie. _end, _etext, etc.), or 976 * - the symbol isn't a SINGLETON, or 977 * - the symbol wasn't explicitly defined within a version 978 * definition associated with an input relocatable object. 979 * 980 * Indicate that the symbol has been reduced as it may be 981 * necessary to print these symbols later. 982 */ 983 if ((oflags & (FLG_OF_AUTOLCL | FLG_OF_AUTOELM)) && 984 ((sdp->sd_flags1 & MSK_SY1_NOAUTO) == 0)) { 985 if ((sdp->sd_flags1 & FLG_SY1_HIDDEN) == 0) { 986 sdp->sd_flags |= FLG_SY_REDUCED; 987 sdp->sd_flags1 |= FLG_SY1_HIDDEN; 988 } 989 990 if (oflags & (FLG_OF_REDLSYM | FLG_OF_AUTOELM)) { 991 sdp->sd_flags1 |= FLG_SY1_ELIM; 992 sym->st_other = STV_ELIMINATE | 993 (sym->st_other & ~MSK_SYM_VISIBILITY); 994 } else if (ELF_ST_VISIBILITY(sym->st_other) != 995 STV_INTERNAL) 996 sym->st_other = STV_HIDDEN | 997 (sym->st_other & ~MSK_SYM_VISIBILITY); 998 } 999 1000 /* 1001 * If -Bsymbolic is in effect, and the symbol hasn't explicitly 1002 * been defined nodirect (via a mapfile), then bind the global 1003 * symbol symbolically and assign the STV_PROTECTED visibility 1004 * attribute. 1005 */ 1006 if ((oflags & FLG_OF_SYMBOLIC) && 1007 ((sdp->sd_flags1 & (FLG_SY1_HIDDEN | FLG_SY1_NDIR)) == 0)) { 1008 sdp->sd_flags1 |= FLG_SY1_PROTECT; 1009 if (ELF_ST_VISIBILITY(sym->st_other) == STV_DEFAULT) 1010 sym->st_other = STV_PROTECTED | 1011 (sym->st_other & ~MSK_SYM_VISIBILITY); 1012 } 1013 } 1014 1015 /* 1016 * Indicate that this symbol has had it's visibility checked so that 1017 * we don't need to do this investigation again. 1018 */ 1019 sdp->sd_flags |= FLG_SY_VISIBLE; 1020 } 1021 1022 /* 1023 * Make sure a symbol definition is local to the object being built. 1024 */ 1025 inline static int 1026 ensure_sym_local(Ofl_desc *ofl, Sym_desc *sdp, const char *str) 1027 { 1028 if (sdp->sd_sym->st_shndx == SHN_UNDEF) { 1029 if (str) { 1030 eprintf(ofl->ofl_lml, ERR_FATAL, 1031 MSG_INTL(MSG_SYM_UNDEF), str, 1032 demangle((char *)sdp->sd_name)); 1033 } 1034 return (1); 1035 } 1036 if (sdp->sd_ref != REF_REL_NEED) { 1037 if (str) { 1038 eprintf(ofl->ofl_lml, ERR_FATAL, 1039 MSG_INTL(MSG_SYM_EXTERN), str, 1040 demangle((char *)sdp->sd_name), 1041 sdp->sd_file->ifl_name); 1042 } 1043 return (1); 1044 } 1045 1046 sdp->sd_flags |= FLG_SY_UPREQD; 1047 if (sdp->sd_isc) { 1048 sdp->sd_isc->is_flags |= FLG_IS_SECTREF; 1049 sdp->sd_isc->is_file->ifl_flags |= FLG_IF_FILEREF; 1050 } 1051 return (0); 1052 } 1053 1054 /* 1055 * Make sure all the symbol definitions required for initarray, finiarray, or 1056 * preinitarray's are local to the object being built. 1057 */ 1058 static int 1059 ensure_array_local(Ofl_desc *ofl, APlist *apl, const char *str) 1060 { 1061 Aliste idx; 1062 Sym_desc *sdp; 1063 int ret = 0; 1064 1065 for (APLIST_TRAVERSE(apl, idx, sdp)) 1066 ret += ensure_sym_local(ofl, sdp, str); 1067 1068 return (ret); 1069 } 1070 1071 /* 1072 * After all symbol table input processing has been finished, and all relocation 1073 * counting has been carried out (ie. no more symbols will be read, generated, 1074 * or modified), validate and count the relevant entries: 1075 * 1076 * - check and print any undefined symbols remaining. Note that 1077 * if a symbol has been defined by virtue of the inclusion of 1078 * an implicit shared library, it is still classed as undefined. 1079 * 1080 * - count the number of global needed symbols together with the 1081 * size of their associated name strings (if scoping has been 1082 * indicated these symbols may be reduced to locals). 1083 * 1084 * - establish the size and alignment requirements for the global 1085 * .bss section (the alignment of this section is based on the 1086 * first symbol that it will contain). 1087 */ 1088 uintptr_t 1089 ld_sym_validate(Ofl_desc *ofl) 1090 { 1091 Sym_avlnode *sav; 1092 Sym_desc *sdp; 1093 Sym *sym; 1094 ofl_flag_t oflags = ofl->ofl_flags; 1095 ofl_flag_t undef = 0, needed = 0, verdesc = 0; 1096 Xword bssalign = 0, tlsalign = 0; 1097 Xword bsssize = 0, tlssize = 0; 1098 #if defined(_ELF64) 1099 Xword lbssalign = 0, lbsssize = 0; 1100 #endif 1101 int ret; 1102 int allow_ldynsym; 1103 uchar_t type; 1104 1105 DBG_CALL(Dbg_basic_validate(ofl->ofl_lml)); 1106 1107 /* 1108 * If a symbol is undefined and this link-edit calls for no undefined 1109 * symbols to remain (this is the default case when generating an 1110 * executable but can be enforced for any object using -z defs), the 1111 * symbol is classified as undefined and a fatal error condition will 1112 * be indicated. 1113 * 1114 * If the symbol is undefined and we're creating a shared object with 1115 * the -Bsymbolic flag, then the symbol is also classified as undefined 1116 * and a warning condition will be indicated. 1117 */ 1118 if ((oflags & (FLG_OF_SHAROBJ | FLG_OF_SYMBOLIC)) == 1119 (FLG_OF_SHAROBJ | FLG_OF_SYMBOLIC)) 1120 undef = FLG_OF_WARN; 1121 if (oflags & FLG_OF_NOUNDEF) 1122 undef = FLG_OF_FATAL; 1123 1124 /* 1125 * If the symbol is referenced from an implicitly included shared object 1126 * (ie. it's not on the NEEDED list) then the symbol is also classified 1127 * as undefined and a fatal error condition will be indicated. 1128 */ 1129 if ((oflags & FLG_OF_NOUNDEF) || !(oflags & FLG_OF_SHAROBJ)) 1130 needed = FLG_OF_FATAL; 1131 1132 /* 1133 * If the output image is being versioned, then all symbol definitions 1134 * must be associated with a version. Any symbol that isn't associated 1135 * with a version is classified as undefined, and a fatal error 1136 * condition is indicated. 1137 */ 1138 if ((oflags & FLG_OF_VERDEF) && (ofl->ofl_vercnt > VER_NDX_GLOBAL)) 1139 verdesc = FLG_OF_FATAL; 1140 1141 allow_ldynsym = OFL_ALLOW_LDYNSYM(ofl); 1142 1143 if (allow_ldynsym) { 1144 /* 1145 * Normally, we disallow symbols with 0 size from appearing 1146 * in a dyn[sym|tls]sort section. However, there are some 1147 * symbols that serve special purposes that we want to exempt 1148 * from this rule. Look them up, and set their 1149 * FLG_SY_DYNSORT flag. 1150 */ 1151 static const char *special[] = { 1152 MSG_ORIG(MSG_SYM_INIT_U), /* _init */ 1153 MSG_ORIG(MSG_SYM_FINI_U), /* _fini */ 1154 MSG_ORIG(MSG_SYM_START), /* _start */ 1155 NULL 1156 }; 1157 int i; 1158 1159 for (i = 0; special[i] != NULL; i++) { 1160 if (((sdp = ld_sym_find(special[i], 1161 SYM_NOHASH, NULL, ofl)) != NULL) && 1162 (sdp->sd_sym->st_size == 0)) { 1163 if (ld_sym_copy(sdp) == S_ERROR) 1164 return (S_ERROR); 1165 sdp->sd_flags |= FLG_SY_DYNSORT; 1166 } 1167 } 1168 } 1169 1170 /* 1171 * Collect and validate the globals from the internal symbol table. 1172 */ 1173 for (sav = avl_first(&ofl->ofl_symavl); sav; 1174 sav = AVL_NEXT(&ofl->ofl_symavl, sav)) { 1175 Is_desc *isp; 1176 int undeferr = 0; 1177 uchar_t vis; 1178 1179 sdp = sav->sav_symdesc; 1180 1181 /* 1182 * If undefined symbols are allowed ignore any symbols that are 1183 * not needed. 1184 */ 1185 if (!(oflags & FLG_OF_NOUNDEF) && 1186 (sdp->sd_ref == REF_DYN_SEEN)) 1187 continue; 1188 1189 /* 1190 * If the symbol originates from an external or parent mapfile 1191 * reference and hasn't been matched to a reference from a 1192 * relocatable object, ignore it. 1193 */ 1194 if ((sdp->sd_flags & (FLG_SY_EXTERN | FLG_SY_PARENT)) && 1195 ((sdp->sd_flags & FLG_SY_MAPUSED) == 0)) { 1196 sdp->sd_flags |= FLG_SY_INVALID; 1197 continue; 1198 } 1199 1200 sym = sdp->sd_sym; 1201 type = ELF_ST_TYPE(sym->st_info); 1202 1203 /* 1204 * Sanity check TLS. 1205 */ 1206 if ((type == STT_TLS) && (sym->st_size != 0) && 1207 (sym->st_shndx != SHN_UNDEF) && 1208 (sym->st_shndx != SHN_COMMON)) { 1209 Is_desc *isp = sdp->sd_isc; 1210 Ifl_desc *ifl = sdp->sd_file; 1211 1212 if ((isp == NULL) || (isp->is_shdr == NULL) || 1213 ((isp->is_shdr->sh_flags & SHF_TLS) == 0)) { 1214 eprintf(ofl->ofl_lml, ERR_FATAL, 1215 MSG_INTL(MSG_SYM_TLS), 1216 demangle(sdp->sd_name), ifl->ifl_name); 1217 ofl->ofl_flags |= FLG_OF_FATAL; 1218 continue; 1219 } 1220 } 1221 1222 if ((sdp->sd_flags & FLG_SY_VISIBLE) == 0) 1223 ld_sym_adjust_vis(sdp, ofl); 1224 1225 if ((sdp->sd_flags & FLG_SY_REDUCED) && 1226 (oflags & FLG_OF_PROCRED)) { 1227 DBG_CALL(Dbg_syms_reduce(ofl, DBG_SYM_REDUCE_GLOBAL, 1228 sdp, 0, 0)); 1229 } 1230 1231 /* 1232 * Record any STV_SINGLETON existence. 1233 */ 1234 if ((vis = ELF_ST_VISIBILITY(sym->st_other)) == STV_SINGLETON) 1235 ofl->ofl_dtflags_1 |= DF_1_SINGLETON; 1236 1237 /* 1238 * If building a shared object or executable, and this is a 1239 * non-weak UNDEF symbol with reduced visibility (STV_*), then 1240 * give a fatal error. 1241 */ 1242 if (((oflags & FLG_OF_RELOBJ) == 0) && 1243 (sym->st_shndx == SHN_UNDEF) && 1244 (ELF_ST_BIND(sym->st_info) != STB_WEAK)) { 1245 if (vis && (vis != STV_SINGLETON)) { 1246 sym_undef_entry(ofl, sdp, BNDLOCAL); 1247 ofl->ofl_flags |= FLG_OF_FATAL; 1248 continue; 1249 } 1250 } 1251 1252 /* 1253 * If this symbol is defined in a non-allocatable section, 1254 * reduce it to local symbol. 1255 */ 1256 if (((isp = sdp->sd_isc) != 0) && isp->is_shdr && 1257 ((isp->is_shdr->sh_flags & SHF_ALLOC) == 0)) { 1258 sdp->sd_flags |= FLG_SY_REDUCED; 1259 sdp->sd_flags1 |= FLG_SY1_HIDDEN; 1260 } 1261 1262 /* 1263 * If this symbol originated as a SHN_SUNW_IGNORE, it will have 1264 * been processed as an SHN_UNDEF. Return the symbol to its 1265 * original index for validation, and propagation to the output 1266 * file. 1267 */ 1268 if (sdp->sd_flags1 & FLG_SY1_IGNORE) 1269 sdp->sd_shndx = SHN_SUNW_IGNORE; 1270 1271 if (undef) { 1272 /* 1273 * If a non-weak reference remains undefined, or if a 1274 * mapfile reference is not bound to the relocatable 1275 * objects that make up the object being built, we have 1276 * a fatal error. 1277 * 1278 * The exceptions are symbols which are defined to be 1279 * found in the parent (FLG_SY_PARENT), which is really 1280 * only meaningful for direct binding, or are defined 1281 * external (FLG_SY_EXTERN) so as to suppress -zdefs 1282 * errors. 1283 * 1284 * Register symbols are always allowed to be UNDEF. 1285 * 1286 * Note that we don't include references created via -u 1287 * in the same shared object binding test. This is for 1288 * backward compatibility, in that a number of archive 1289 * makefile rules used -u to cause archive extraction. 1290 * These same rules have been cut and pasted to apply 1291 * to shared objects, and thus although the -u reference 1292 * is redundant, flagging it as fatal could cause some 1293 * build to fail. Also we have documented the use of 1294 * -u as a mechanism to cause binding to weak version 1295 * definitions, thus giving users an error condition 1296 * would be incorrect. 1297 */ 1298 if (!(sdp->sd_flags & FLG_SY_REGSYM) && 1299 ((sym->st_shndx == SHN_UNDEF) && 1300 ((ELF_ST_BIND(sym->st_info) != STB_WEAK) && 1301 ((sdp->sd_flags & 1302 (FLG_SY_PARENT | FLG_SY_EXTERN)) == 0)) || 1303 (((sdp->sd_flags & 1304 (FLG_SY_MAPREF | FLG_SY_MAPUSED)) == 1305 FLG_SY_MAPREF) && 1306 ((sdp->sd_flags1 & (FLG_SY1_HIDDEN | 1307 FLG_SY1_PROTECT)) == 0)))) { 1308 sym_undef_entry(ofl, sdp, UNDEF); 1309 ofl->ofl_flags |= undef; 1310 undeferr = 1; 1311 } 1312 1313 } else { 1314 /* 1315 * For building things like shared objects (or anything 1316 * -znodefs), undefined symbols are allowed. 1317 * 1318 * If a mapfile reference remains undefined the user 1319 * would probably like a warning at least (they've 1320 * usually mis-spelt the reference). Refer to the above 1321 * comments for discussion on -u references, which 1322 * are not tested for in the same manner. 1323 */ 1324 if ((sdp->sd_flags & 1325 (FLG_SY_MAPREF | FLG_SY_MAPUSED)) == 1326 FLG_SY_MAPREF) { 1327 sym_undef_entry(ofl, sdp, UNDEF); 1328 ofl->ofl_flags |= FLG_OF_WARN; 1329 undeferr = 1; 1330 } 1331 } 1332 1333 /* 1334 * If this symbol comes from a dependency mark the dependency 1335 * as required (-z ignore can result in unused dependencies 1336 * being dropped). If we need to record dependency versioning 1337 * information indicate what version of the needed shared object 1338 * this symbol is part of. Flag the symbol as undefined if it 1339 * has not been made available to us. 1340 */ 1341 if ((sdp->sd_ref == REF_DYN_NEED) && 1342 (!(sdp->sd_flags & FLG_SY_REFRSD))) { 1343 sdp->sd_file->ifl_flags |= FLG_IF_DEPREQD; 1344 1345 /* 1346 * Capture that we've bound to a symbol that doesn't 1347 * allow being directly bound to. 1348 */ 1349 if (sdp->sd_flags1 & FLG_SY1_NDIR) 1350 ofl->ofl_flags1 |= FLG_OF1_NGLBDIR; 1351 1352 if (sdp->sd_file->ifl_vercnt) { 1353 int vndx; 1354 Ver_index *vip; 1355 1356 vndx = sdp->sd_aux->sa_dverndx; 1357 vip = &sdp->sd_file->ifl_verndx[vndx]; 1358 if (vip->vi_flags & FLG_VER_AVAIL) { 1359 vip->vi_flags |= FLG_VER_REFER; 1360 } else { 1361 sym_undef_entry(ofl, sdp, NOTAVAIL); 1362 ofl->ofl_flags |= FLG_OF_FATAL; 1363 continue; 1364 } 1365 } 1366 } 1367 1368 /* 1369 * Test that we do not bind to symbol supplied from an implicit 1370 * shared object. If a binding is from a weak reference it can 1371 * be ignored. 1372 */ 1373 if (needed && !undeferr && (sdp->sd_flags & FLG_SY_GLOBREF) && 1374 (sdp->sd_ref == REF_DYN_NEED) && 1375 (sdp->sd_flags & FLG_SY_NOTAVAIL)) { 1376 sym_undef_entry(ofl, sdp, IMPLICIT); 1377 ofl->ofl_flags |= needed; 1378 continue; 1379 } 1380 1381 /* 1382 * Test that a symbol isn't going to be reduced to local scope 1383 * which actually wants to bind to a shared object - if so it's 1384 * a fatal error. 1385 */ 1386 if ((sdp->sd_ref == REF_DYN_NEED) && 1387 (sdp->sd_flags1 & (FLG_SY1_HIDDEN | FLG_SY1_PROTECT))) { 1388 sym_undef_entry(ofl, sdp, BNDLOCAL); 1389 ofl->ofl_flags |= FLG_OF_FATAL; 1390 continue; 1391 } 1392 1393 /* 1394 * If the output image is to be versioned then all symbol 1395 * definitions must be associated with a version. Remove any 1396 * versioning that might be left associated with an undefined 1397 * symbol. 1398 */ 1399 if (verdesc && (sdp->sd_ref == REF_REL_NEED)) { 1400 if (sym->st_shndx == SHN_UNDEF) { 1401 if (sdp->sd_aux && sdp->sd_aux->sa_overndx) 1402 sdp->sd_aux->sa_overndx = 0; 1403 } else { 1404 if ((!(sdp->sd_flags1 & FLG_SY1_HIDDEN)) && 1405 sdp->sd_aux && 1406 (sdp->sd_aux->sa_overndx == 0)) { 1407 sym_undef_entry(ofl, sdp, NOVERSION); 1408 ofl->ofl_flags |= verdesc; 1409 continue; 1410 } 1411 } 1412 } 1413 1414 /* 1415 * If we don't need the symbol there's no need to process it 1416 * any further. 1417 */ 1418 if (sdp->sd_ref == REF_DYN_SEEN) 1419 continue; 1420 1421 /* 1422 * Calculate the size and alignment requirements for the global 1423 * .bss and .tls sections. If we're building a relocatable 1424 * object only account for scoped COMMON symbols (these will 1425 * be converted to .bss references). 1426 * 1427 * When -z nopartial is in effect, partially initialized 1428 * symbols are directed to the special .data section 1429 * created for that purpose (ofl->ofl_isparexpn). 1430 * Otherwise, partially initialized symbols go to .bss. 1431 * 1432 * Also refer to make_mvsections() in sunwmove.c 1433 */ 1434 if ((sym->st_shndx == SHN_COMMON) && 1435 (((oflags & FLG_OF_RELOBJ) == 0) || 1436 ((sdp->sd_flags1 & FLG_SY1_HIDDEN) && 1437 (oflags & FLG_OF_PROCRED)))) { 1438 if ((sdp->sd_move == NULL) || 1439 ((sdp->sd_flags & FLG_SY_PAREXPN) == 0)) { 1440 Xword * size, * align; 1441 1442 if (type != STT_TLS) { 1443 size = &bsssize; 1444 align = &bssalign; 1445 } else { 1446 size = &tlssize; 1447 align = &tlsalign; 1448 } 1449 *size = (Xword)S_ROUND(*size, sym->st_value) + 1450 sym->st_size; 1451 if (sym->st_value > *align) 1452 *align = sym->st_value; 1453 } 1454 } 1455 1456 #if defined(_ELF64) 1457 /* 1458 * Calculate the size and alignment requirement for the global 1459 * .lbss. TLS or partially initialized symbols do not need to be 1460 * considered yet. 1461 */ 1462 if ((ld_targ.t_m.m_mach == EM_AMD64) && 1463 (sym->st_shndx == SHN_X86_64_LCOMMON)) { 1464 lbsssize = (Xword)S_ROUND(lbsssize, sym->st_value) + 1465 sym->st_size; 1466 if (sym->st_value > lbssalign) 1467 lbssalign = sym->st_value; 1468 } 1469 #endif 1470 1471 /* 1472 * If a symbol was referenced via the command line 1473 * (ld -u <>, ...), then this counts as a reference against the 1474 * symbol. Mark any section that symbol is defined in. 1475 */ 1476 if (((isp = sdp->sd_isc) != 0) && 1477 (sdp->sd_flags & FLG_SY_CMDREF)) { 1478 isp->is_flags |= FLG_IS_SECTREF; 1479 isp->is_file->ifl_flags |= FLG_IF_FILEREF; 1480 } 1481 1482 /* 1483 * Update the symbol count and the associated name string size. 1484 */ 1485 if ((sdp->sd_flags1 & FLG_SY1_HIDDEN) && 1486 (oflags & FLG_OF_PROCRED)) { 1487 /* 1488 * If any reductions are being processed, keep a count 1489 * of eliminated symbols, and if the symbol is being 1490 * reduced to local, count it's size for the .symtab. 1491 */ 1492 if (sdp->sd_flags1 & FLG_SY1_ELIM) { 1493 ofl->ofl_elimcnt++; 1494 } else { 1495 ofl->ofl_scopecnt++; 1496 if ((((sdp->sd_flags & FLG_SY_REGSYM) == 0) || 1497 sym->st_name) && (st_insert(ofl->ofl_strtab, 1498 sdp->sd_name) == -1)) 1499 return (S_ERROR); 1500 if (allow_ldynsym && sym->st_name && 1501 ldynsym_symtype[type]) { 1502 ofl->ofl_dynscopecnt++; 1503 if (st_insert(ofl->ofl_dynstrtab, 1504 sdp->sd_name) == -1) 1505 return (S_ERROR); 1506 /* Include it in sort section? */ 1507 DYNSORT_COUNT(sdp, sym, type, ++); 1508 } 1509 } 1510 } else { 1511 ofl->ofl_globcnt++; 1512 1513 /* 1514 * Check to see if this global variable should 1515 * go into a sort section. Sort sections require 1516 * a .SUNW_ldynsym section, so, don't check 1517 * unless a .SUNW_ldynsym is allowed. 1518 */ 1519 if (allow_ldynsym) { 1520 DYNSORT_COUNT(sdp, sym, type, ++); 1521 } 1522 1523 /* 1524 * If global direct bindings are in effect, or this 1525 * symbol has bound to a dependency which was specified 1526 * as requiring direct bindings, and it hasn't 1527 * explicitly been defined as a non-direct binding 1528 * symbol, mark it. 1529 */ 1530 if (((ofl->ofl_dtflags_1 & DF_1_DIRECT) || (isp && 1531 (isp->is_file->ifl_flags & FLG_IF_DIRECT))) && 1532 ((sdp->sd_flags1 & FLG_SY1_NDIR) == 0)) 1533 sdp->sd_flags1 |= FLG_SY1_DIR; 1534 1535 /* 1536 * Insert the symbol name. 1537 */ 1538 if (((sdp->sd_flags & FLG_SY_REGSYM) == 0) || 1539 sym->st_name) { 1540 if (st_insert(ofl->ofl_strtab, 1541 sdp->sd_name) == -1) 1542 return (S_ERROR); 1543 1544 if (!(ofl->ofl_flags & FLG_OF_RELOBJ) && 1545 (st_insert(ofl->ofl_dynstrtab, 1546 sdp->sd_name) == -1)) 1547 return (S_ERROR); 1548 } 1549 1550 /* 1551 * If this section offers a global symbol - record that 1552 * fact. 1553 */ 1554 if (isp) { 1555 isp->is_flags |= FLG_IS_SECTREF; 1556 isp->is_file->ifl_flags |= FLG_IF_FILEREF; 1557 } 1558 } 1559 } 1560 1561 /* 1562 * If we've encountered a fatal error during symbol validation then 1563 * return now. 1564 */ 1565 if (ofl->ofl_flags & FLG_OF_FATAL) 1566 return (1); 1567 1568 /* 1569 * Now that symbol resolution is completed, scan any register symbols. 1570 * From now on, we're only interested in those that contribute to the 1571 * output file. 1572 */ 1573 if (ofl->ofl_regsyms) { 1574 int ndx; 1575 1576 for (ndx = 0; ndx < ofl->ofl_regsymsno; ndx++) { 1577 if ((sdp = ofl->ofl_regsyms[ndx]) == NULL) 1578 continue; 1579 if (sdp->sd_ref != REF_REL_NEED) { 1580 ofl->ofl_regsyms[ndx] = NULL; 1581 continue; 1582 } 1583 1584 ofl->ofl_regsymcnt++; 1585 if (sdp->sd_sym->st_name == 0) 1586 sdp->sd_name = MSG_ORIG(MSG_STR_EMPTY); 1587 1588 if ((sdp->sd_flags1 & FLG_SY1_HIDDEN) || 1589 (ELF_ST_BIND(sdp->sd_sym->st_info) == STB_LOCAL)) 1590 ofl->ofl_lregsymcnt++; 1591 } 1592 } 1593 1594 /* 1595 * Generate the .bss section now that we know its size and alignment. 1596 */ 1597 if (bsssize) { 1598 if (ld_make_bss(ofl, bsssize, bssalign, 1599 ld_targ.t_id.id_bss) == S_ERROR) 1600 return (S_ERROR); 1601 } 1602 if (tlssize) { 1603 if (ld_make_bss(ofl, tlssize, tlsalign, 1604 ld_targ.t_id.id_tlsbss) == S_ERROR) 1605 return (S_ERROR); 1606 } 1607 #if defined(_ELF64) 1608 if ((ld_targ.t_m.m_mach == EM_AMD64) && 1609 lbsssize && !(oflags & FLG_OF_RELOBJ)) { 1610 if (ld_make_bss(ofl, lbsssize, lbssalign, 1611 ld_targ.t_id.id_lbss) == S_ERROR) 1612 return (S_ERROR); 1613 } 1614 #endif 1615 /* 1616 * Determine what entry point symbol we need, and if found save its 1617 * symbol descriptor so that we can update the ELF header entry with the 1618 * symbols value later (see update_oehdr). Make sure the symbol is 1619 * tagged to ensure its update in case -s is in effect. Use any -e 1620 * option first, or the default entry points `_start' and `main'. 1621 */ 1622 ret = 0; 1623 if (ofl->ofl_entry) { 1624 if ((sdp = ld_sym_find(ofl->ofl_entry, SYM_NOHASH, 1625 NULL, ofl)) == NULL) { 1626 eprintf(ofl->ofl_lml, ERR_FATAL, 1627 MSG_INTL(MSG_ARG_NOENTRY), ofl->ofl_entry); 1628 ret++; 1629 } else if (ensure_sym_local(ofl, sdp, 1630 MSG_INTL(MSG_SYM_ENTRY)) != 0) { 1631 ret++; 1632 } else { 1633 ofl->ofl_entry = (void *)sdp; 1634 } 1635 } else if (((sdp = ld_sym_find(MSG_ORIG(MSG_SYM_START), 1636 SYM_NOHASH, NULL, ofl)) != NULL) && (ensure_sym_local(ofl, 1637 sdp, 0) == 0)) { 1638 ofl->ofl_entry = (void *)sdp; 1639 1640 } else if (((sdp = ld_sym_find(MSG_ORIG(MSG_SYM_MAIN), 1641 SYM_NOHASH, NULL, ofl)) != NULL) && (ensure_sym_local(ofl, 1642 sdp, 0) == 0)) { 1643 ofl->ofl_entry = (void *)sdp; 1644 } 1645 1646 /* 1647 * If ld -zdtrace=<sym> was given, then validate that the symbol is 1648 * defined within the current object being built. 1649 */ 1650 if ((sdp = ofl->ofl_dtracesym) != 0) 1651 ret += ensure_sym_local(ofl, sdp, MSG_ORIG(MSG_STR_DTRACE)); 1652 1653 /* 1654 * If any initarray, finiarray or preinitarray functions have been 1655 * requested, make sure they are defined within the current object 1656 * being built. 1657 */ 1658 if (ofl->ofl_initarray) { 1659 ret += ensure_array_local(ofl, ofl->ofl_initarray, 1660 MSG_ORIG(MSG_SYM_INITARRAY)); 1661 } 1662 if (ofl->ofl_finiarray) { 1663 ret += ensure_array_local(ofl, ofl->ofl_finiarray, 1664 MSG_ORIG(MSG_SYM_FINIARRAY)); 1665 } 1666 if (ofl->ofl_preiarray) { 1667 ret += ensure_array_local(ofl, ofl->ofl_preiarray, 1668 MSG_ORIG(MSG_SYM_PREINITARRAY)); 1669 } 1670 1671 if (ret) 1672 return (S_ERROR); 1673 1674 /* 1675 * If we're required to record any needed dependencies versioning 1676 * information calculate it now that all symbols have been validated. 1677 */ 1678 if ((oflags & (FLG_OF_VERNEED | FLG_OF_NOVERSEC)) == FLG_OF_VERNEED) 1679 return (ld_vers_check_need(ofl)); 1680 else 1681 return (1); 1682 } 1683 1684 /* 1685 * qsort(3c) comparison function. As an optimization for associating weak 1686 * symbols to their strong counterparts sort global symbols according to their 1687 * section index, address and binding. 1688 */ 1689 static int 1690 compare(const void *sdpp1, const void *sdpp2) 1691 { 1692 Sym_desc *sdp1 = *((Sym_desc **)sdpp1); 1693 Sym_desc *sdp2 = *((Sym_desc **)sdpp2); 1694 Sym *sym1, *sym2; 1695 uchar_t bind1, bind2; 1696 1697 /* 1698 * Symbol descriptors may be zero, move these to the front of the 1699 * sorted array. 1700 */ 1701 if (sdp1 == NULL) 1702 return (-1); 1703 if (sdp2 == NULL) 1704 return (1); 1705 1706 sym1 = sdp1->sd_sym; 1707 sym2 = sdp2->sd_sym; 1708 1709 /* 1710 * Compare the symbols section index. This is important when sorting 1711 * the symbol tables of relocatable objects. In this case, a symbols 1712 * value is the offset within the associated section, and thus many 1713 * symbols can have the same value, but are effectively different 1714 * addresses. 1715 */ 1716 if (sym1->st_shndx > sym2->st_shndx) 1717 return (1); 1718 if (sym1->st_shndx < sym2->st_shndx) 1719 return (-1); 1720 1721 /* 1722 * Compare the symbols value (address). 1723 */ 1724 if (sym1->st_value > sym2->st_value) 1725 return (1); 1726 if (sym1->st_value < sym2->st_value) 1727 return (-1); 1728 1729 bind1 = ELF_ST_BIND(sym1->st_info); 1730 bind2 = ELF_ST_BIND(sym2->st_info); 1731 1732 /* 1733 * If two symbols have the same address place the weak symbol before 1734 * any strong counterpart. 1735 */ 1736 if (bind1 > bind2) 1737 return (-1); 1738 if (bind1 < bind2) 1739 return (1); 1740 1741 return (0); 1742 } 1743 1744 /* 1745 * Issue a MSG_SYM_BADADDR error from ld_sym_process(). This error 1746 * is issued when a symbol address/size is not contained by the 1747 * target section. 1748 * 1749 * Such objects are at least partially corrupt, and the user would 1750 * be well advised to be skeptical of them, and to ask their compiler 1751 * supplier to fix the problem. However, a distinction needs to be 1752 * made between symbols that reference readonly text, and those that 1753 * access writable data. Other than throwing off profiling results, 1754 * the readonly section case is less serious. We have encountered 1755 * such objects in the field. In order to allow existing objects 1756 * to continue working, we issue a warning rather than a fatal error 1757 * if the symbol is against readonly text. Other cases are fatal. 1758 */ 1759 static void 1760 issue_badaddr_msg(Ifl_desc *ifl, Ofl_desc *ofl, Sym_desc *sdp, 1761 Sym *sym, Word shndx) 1762 { 1763 ofl_flag_t flag; 1764 Error err; 1765 const char *msg; 1766 1767 if ((sdp->sd_isc->is_shdr->sh_flags & (SHF_WRITE | SHF_ALLOC)) == 1768 SHF_ALLOC) { 1769 msg = MSG_INTL(MSG_SYM_BADADDR_ROTXT); 1770 flag = FLG_OF_WARN; 1771 err = ERR_WARNING; 1772 } else { 1773 msg = MSG_INTL(MSG_SYM_BADADDR); 1774 flag = FLG_OF_FATAL; 1775 err = ERR_FATAL; 1776 } 1777 1778 eprintf(ofl->ofl_lml, err, msg, demangle(sdp->sd_name), 1779 ifl->ifl_name, shndx, sdp->sd_isc->is_name, 1780 EC_XWORD(sdp->sd_isc->is_shdr->sh_size), 1781 EC_XWORD(sym->st_value), EC_XWORD(sym->st_size)); 1782 ofl->ofl_flags |= flag; 1783 } 1784 1785 1786 /* 1787 * Process the symbol table for the specified input file. At this point all 1788 * input sections from this input file have been assigned an input section 1789 * descriptor which is saved in the `ifl_isdesc' array. 1790 * 1791 * - local symbols are saved (as is) if the input file is a 1792 * relocatable object 1793 * 1794 * - global symbols are added to the linkers internal symbol 1795 * table if they are not already present, otherwise a symbol 1796 * resolution function is called upon to resolve the conflict. 1797 */ 1798 uintptr_t 1799 ld_sym_process(Is_desc *isc, Ifl_desc *ifl, Ofl_desc *ofl) 1800 { 1801 /* 1802 * This macro tests the given symbol to see if it is out of 1803 * range relative to the section it references. 1804 * 1805 * entry: 1806 * - ifl is a relative object (ET_REL) 1807 * _sdp - Symbol descriptor 1808 * _sym - Symbol 1809 * _type - Symbol type 1810 * 1811 * The following are tested: 1812 * - Symbol length is non-zero 1813 * - Symbol type is a type that references code or data 1814 * - Referenced section is not 0 (indicates an UNDEF symbol) 1815 * and is not in the range of special values above SHN_LORESERVE 1816 * (excluding SHN_XINDEX, which is OK). 1817 * - We have a valid section header for the target section 1818 * 1819 * If the above are all true, and the symbol position is not 1820 * contained by the target section, this macro evaluates to 1821 * True (1). Otherwise, False(0). 1822 */ 1823 #define SYM_LOC_BADADDR(_sdp, _sym, _type) \ 1824 (_sym->st_size && dynsymsort_symtype[_type] && \ 1825 (_sym->st_shndx != SHN_UNDEF) && \ 1826 ((_sym->st_shndx < SHN_LORESERVE) || \ 1827 (_sym->st_shndx == SHN_XINDEX)) && \ 1828 _sdp->sd_isc && _sdp->sd_isc->is_shdr && \ 1829 ((_sym->st_value + _sym->st_size) > _sdp->sd_isc->is_shdr->sh_size)) 1830 1831 Conv_inv_buf_t inv_buf; 1832 Sym *sym = (Sym *)isc->is_indata->d_buf; 1833 Word *symshndx = NULL; 1834 Shdr *shdr = isc->is_shdr; 1835 Sym_desc *sdp; 1836 size_t strsize; 1837 char *strs; 1838 uchar_t type, bind; 1839 Word ndx, hash, local, total; 1840 uchar_t osabi = ifl->ifl_ehdr->e_ident[EI_OSABI]; 1841 Half mach = ifl->ifl_ehdr->e_machine; 1842 Half etype = ifl->ifl_ehdr->e_type; 1843 int etype_rel; 1844 const char *symsecname, *strsecname; 1845 Word symsecndx; 1846 avl_index_t where; 1847 int test_gnu_hidden_bit, weak; 1848 1849 /* 1850 * Its possible that a file may contain more that one symbol table, 1851 * ie. .dynsym and .symtab in a shared library. Only process the first 1852 * table (here, we assume .dynsym comes before .symtab). 1853 */ 1854 if (ifl->ifl_symscnt) 1855 return (1); 1856 1857 if (isc->is_symshndx) 1858 symshndx = isc->is_symshndx->is_indata->d_buf; 1859 1860 DBG_CALL(Dbg_syms_process(ofl->ofl_lml, ifl)); 1861 1862 symsecndx = isc->is_scnndx; 1863 if (isc->is_name) 1864 symsecname = isc->is_name; 1865 else 1866 symsecname = MSG_ORIG(MSG_STR_EMPTY); 1867 1868 /* 1869 * From the symbol tables section header information determine which 1870 * strtab table is needed to locate the actual symbol names. 1871 */ 1872 if (ifl->ifl_flags & FLG_IF_HSTRTAB) { 1873 ndx = shdr->sh_link; 1874 if ((ndx == 0) || (ndx >= ifl->ifl_shnum)) { 1875 eprintf(ofl->ofl_lml, ERR_FATAL, 1876 MSG_INTL(MSG_FIL_INVSHLINK), ifl->ifl_name, 1877 EC_WORD(symsecndx), symsecname, EC_XWORD(ndx)); 1878 return (S_ERROR); 1879 } 1880 strsize = ifl->ifl_isdesc[ndx]->is_shdr->sh_size; 1881 strs = ifl->ifl_isdesc[ndx]->is_indata->d_buf; 1882 if (ifl->ifl_isdesc[ndx]->is_name) 1883 strsecname = ifl->ifl_isdesc[ndx]->is_name; 1884 else 1885 strsecname = MSG_ORIG(MSG_STR_EMPTY); 1886 } else { 1887 /* 1888 * There is no string table section in this input file 1889 * although there are symbols in this symbol table section. 1890 * This means that these symbols do not have names. 1891 * Currently, only scratch register symbols are allowed 1892 * not to have names. 1893 */ 1894 strsize = 0; 1895 strs = (char *)MSG_ORIG(MSG_STR_EMPTY); 1896 strsecname = MSG_ORIG(MSG_STR_EMPTY); 1897 } 1898 1899 /* 1900 * Determine the number of local symbols together with the total 1901 * number we have to process. 1902 */ 1903 total = (Word)(shdr->sh_size / shdr->sh_entsize); 1904 local = shdr->sh_info; 1905 1906 /* 1907 * Allocate a symbol table index array and a local symbol array 1908 * (global symbols are processed and added to the ofl->ofl_symbkt[] 1909 * array). If we are dealing with a relocatable object, allocate the 1910 * local symbol descriptors. If this isn't a relocatable object we 1911 * still have to process any shared object locals to determine if any 1912 * register symbols exist. Although these aren't added to the output 1913 * image, they are used as part of symbol resolution. 1914 */ 1915 if ((ifl->ifl_oldndx = libld_malloc((size_t)(total * 1916 sizeof (Sym_desc *)))) == NULL) 1917 return (S_ERROR); 1918 etype_rel = (etype == ET_REL); 1919 if (etype_rel && local) { 1920 if ((ifl->ifl_locs = 1921 libld_calloc(sizeof (Sym_desc), local)) == NULL) 1922 return (S_ERROR); 1923 /* LINTED */ 1924 ifl->ifl_locscnt = (Word)local; 1925 } 1926 ifl->ifl_symscnt = total; 1927 1928 /* 1929 * If there are local symbols to save add them to the symbol table 1930 * index array. 1931 */ 1932 if (local) { 1933 int allow_ldynsym = OFL_ALLOW_LDYNSYM(ofl); 1934 Sym_desc *last_file_sdp = NULL; 1935 int last_file_ndx = 0; 1936 1937 for (sym++, ndx = 1; ndx < local; sym++, ndx++) { 1938 Word shndx, sdflags = FLG_SY_CLEAN; 1939 const char *name; 1940 Sym_desc *rsdp; 1941 int shndx_bad = 0; 1942 int symtab_enter = 1; 1943 1944 /* 1945 * Determine and validate the associated section index. 1946 */ 1947 if (symshndx && (sym->st_shndx == SHN_XINDEX)) { 1948 shndx = symshndx[ndx]; 1949 } else if ((shndx = sym->st_shndx) >= SHN_LORESERVE) { 1950 sdflags |= FLG_SY_SPECSEC; 1951 } else if (shndx > ifl->ifl_ehdr->e_shnum) { 1952 /* We need the name before we can issue error */ 1953 shndx_bad = 1; 1954 } 1955 1956 /* 1957 * Check if st_name has a valid value or not. 1958 */ 1959 if ((name = string(ofl, ifl, sym, strs, strsize, ndx, 1960 shndx, symsecndx, symsecname, strsecname, 1961 &sdflags)) == NULL) { 1962 ofl->ofl_flags |= FLG_OF_FATAL; 1963 continue; 1964 } 1965 1966 /* 1967 * Now that we have the name, if the section index 1968 * was bad, report it. 1969 */ 1970 if (shndx_bad) { 1971 eprintf(ofl->ofl_lml, ERR_WARNING, 1972 MSG_INTL(MSG_SYM_INVSHNDX), 1973 demangle_symname(name, symsecname, ndx), 1974 ifl->ifl_name, 1975 conv_sym_shndx(osabi, mach, sym->st_shndx, 1976 CONV_FMT_DECIMAL, &inv_buf)); 1977 continue; 1978 } 1979 1980 /* 1981 * If this local symbol table originates from a shared 1982 * object, then we're only interested in recording 1983 * register symbols. As local symbol descriptors aren't 1984 * allocated for shared objects, one will be allocated 1985 * to associated with the register symbol. This symbol 1986 * won't become part of the output image, but we must 1987 * process it to test for register conflicts. 1988 */ 1989 rsdp = sdp = NULL; 1990 if (sdflags & FLG_SY_REGSYM) { 1991 /* 1992 * The presence of FLG_SY_REGSYM means that 1993 * the pointers in ld_targ.t_ms are non-NULL. 1994 */ 1995 rsdp = (*ld_targ.t_ms.ms_reg_find)(sym, ofl); 1996 if (rsdp != 0) { 1997 /* 1998 * The fact that another register def- 1999 * inition has been found is fatal. 2000 * Call the verification routine to get 2001 * the error message and move on. 2002 */ 2003 (void) (*ld_targ.t_ms.ms_reg_check) 2004 (rsdp, sym, name, ifl, ofl); 2005 continue; 2006 } 2007 2008 if (etype == ET_DYN) { 2009 if ((sdp = libld_calloc( 2010 sizeof (Sym_desc), 1)) == NULL) 2011 return (S_ERROR); 2012 sdp->sd_ref = REF_DYN_SEEN; 2013 2014 /* Will not appear in output object */ 2015 symtab_enter = 0; 2016 } 2017 } else if (etype == ET_DYN) 2018 continue; 2019 2020 /* 2021 * Fill in the remaining symbol descriptor information. 2022 */ 2023 if (sdp == NULL) { 2024 sdp = &(ifl->ifl_locs[ndx]); 2025 sdp->sd_ref = REF_REL_NEED; 2026 } 2027 if (rsdp == NULL) { 2028 sdp->sd_name = name; 2029 sdp->sd_sym = sym; 2030 sdp->sd_shndx = shndx; 2031 sdp->sd_flags = sdflags; 2032 sdp->sd_file = ifl; 2033 ifl->ifl_oldndx[ndx] = sdp; 2034 } 2035 2036 DBG_CALL(Dbg_syms_entry(ofl->ofl_lml, ndx, sdp)); 2037 2038 /* 2039 * Reclassify any SHN_SUNW_IGNORE symbols to SHN_UNDEF 2040 * so as to simplify future processing. 2041 */ 2042 if (sym->st_shndx == SHN_SUNW_IGNORE) { 2043 sdp->sd_shndx = shndx = SHN_UNDEF; 2044 sdp->sd_flags1 |= 2045 (FLG_SY1_IGNORE | FLG_SY1_ELIM); 2046 } 2047 2048 /* 2049 * Process any register symbols. 2050 */ 2051 if (sdp->sd_flags & FLG_SY_REGSYM) { 2052 /* 2053 * Add a diagnostic to indicate we've caught a 2054 * register symbol, as this can be useful if a 2055 * register conflict is later discovered. 2056 */ 2057 DBG_CALL(Dbg_syms_entered(ofl, sym, sdp)); 2058 2059 /* 2060 * If this register symbol hasn't already been 2061 * recorded, enter it now. 2062 * 2063 * The presence of FLG_SY_REGSYM means that 2064 * the pointers in ld_targ.t_ms are non-NULL. 2065 */ 2066 if ((rsdp == NULL) && 2067 ((*ld_targ.t_ms.ms_reg_enter)(sdp, ofl) == 2068 0)) 2069 return (S_ERROR); 2070 } 2071 2072 /* 2073 * Assign an input section. 2074 */ 2075 if ((sym->st_shndx != SHN_UNDEF) && 2076 ((sdp->sd_flags & FLG_SY_SPECSEC) == 0)) 2077 sdp->sd_isc = ifl->ifl_isdesc[shndx]; 2078 2079 /* 2080 * If this symbol falls within the range of a section 2081 * being discarded, then discard the symbol itself. 2082 * There is no reason to keep this local symbol. 2083 */ 2084 if (sdp->sd_isc && 2085 (sdp->sd_isc->is_flags & FLG_IS_DISCARD)) { 2086 sdp->sd_flags |= FLG_SY_ISDISC; 2087 DBG_CALL(Dbg_syms_discarded(ofl->ofl_lml, sdp)); 2088 continue; 2089 } 2090 2091 /* 2092 * Skip any section symbols as new versions of these 2093 * will be created. 2094 */ 2095 if ((type = ELF_ST_TYPE(sym->st_info)) == STT_SECTION) { 2096 if (sym->st_shndx == SHN_UNDEF) { 2097 eprintf(ofl->ofl_lml, ERR_WARNING, 2098 MSG_INTL(MSG_SYM_INVSHNDX), 2099 demangle_symname(name, symsecname, 2100 ndx), ifl->ifl_name, 2101 conv_sym_shndx(osabi, mach, 2102 sym->st_shndx, CONV_FMT_DECIMAL, 2103 &inv_buf)); 2104 } 2105 continue; 2106 } 2107 2108 /* 2109 * For a relocatable object, if this symbol is defined 2110 * and has non-zero length and references an address 2111 * within an associated section, then check its extents 2112 * to make sure the section boundaries encompass it. 2113 * If they don't, the ELF file is corrupt. 2114 */ 2115 if (etype_rel) { 2116 if (SYM_LOC_BADADDR(sdp, sym, type)) { 2117 issue_badaddr_msg(ifl, ofl, sdp, 2118 sym, shndx); 2119 if (ofl->ofl_flags & FLG_OF_FATAL) 2120 continue; 2121 } 2122 2123 /* 2124 * We have observed relocatable objects 2125 * containing identical adjacent STT_FILE 2126 * symbols. Discard any other than the first, 2127 * as they are all equivalent and the extras 2128 * do not add information. 2129 * 2130 * For the purpose of this test, we assume 2131 * that only the symbol type and the string 2132 * table offset (st_name) matter. 2133 */ 2134 if (type == STT_FILE) { 2135 int toss = (last_file_sdp != NULL) && 2136 ((ndx - 1) == last_file_ndx) && 2137 (sym->st_name == 2138 last_file_sdp->sd_sym->st_name); 2139 2140 last_file_sdp = sdp; 2141 last_file_ndx = ndx; 2142 if (toss) { 2143 sdp->sd_flags |= FLG_SY_INVALID; 2144 DBG_CALL(Dbg_syms_dup_discarded( 2145 ofl->ofl_lml, ndx, sdp)); 2146 continue; 2147 } 2148 } 2149 } 2150 2151 2152 /* 2153 * Sanity check for TLS 2154 */ 2155 if ((sym->st_size != 0) && ((type == STT_TLS) && 2156 (sym->st_shndx != SHN_COMMON))) { 2157 Is_desc *isp = sdp->sd_isc; 2158 2159 if ((isp == NULL) || (isp->is_shdr == NULL) || 2160 ((isp->is_shdr->sh_flags & SHF_TLS) == 0)) { 2161 eprintf(ofl->ofl_lml, ERR_FATAL, 2162 MSG_INTL(MSG_SYM_TLS), 2163 demangle(sdp->sd_name), 2164 ifl->ifl_name); 2165 ofl->ofl_flags |= FLG_OF_FATAL; 2166 continue; 2167 } 2168 } 2169 2170 /* 2171 * Carry our some basic sanity checks (these are just 2172 * some of the erroneous symbol entries we've come 2173 * across, there's probably a lot more). The symbol 2174 * will not be carried forward to the output file, which 2175 * won't be a problem unless a relocation is required 2176 * against it. 2177 */ 2178 if (((sdp->sd_flags & FLG_SY_SPECSEC) && 2179 ((sym->st_shndx == SHN_COMMON)) || 2180 ((type == STT_FILE) && 2181 (sym->st_shndx != SHN_ABS))) || 2182 (sdp->sd_isc && (sdp->sd_isc->is_osdesc == NULL))) { 2183 eprintf(ofl->ofl_lml, ERR_WARNING, 2184 MSG_INTL(MSG_SYM_INVSHNDX), 2185 demangle_symname(name, symsecname, ndx), 2186 ifl->ifl_name, 2187 conv_sym_shndx(osabi, mach, sym->st_shndx, 2188 CONV_FMT_DECIMAL, &inv_buf)); 2189 sdp->sd_isc = NULL; 2190 sdp->sd_flags |= FLG_SY_INVALID; 2191 continue; 2192 } 2193 2194 /* 2195 * As these local symbols will become part of the output 2196 * image, record their number and name string size. 2197 * Globals are counted after all input file processing 2198 * (and hence symbol resolution) is complete during 2199 * sym_validate(). 2200 */ 2201 if (!(ofl->ofl_flags & FLG_OF_REDLSYM) && 2202 symtab_enter) { 2203 ofl->ofl_locscnt++; 2204 2205 if ((((sdp->sd_flags & FLG_SY_REGSYM) == 0) || 2206 sym->st_name) && (st_insert(ofl->ofl_strtab, 2207 sdp->sd_name) == -1)) 2208 return (S_ERROR); 2209 2210 if (allow_ldynsym && sym->st_name && 2211 ldynsym_symtype[type]) { 2212 ofl->ofl_dynlocscnt++; 2213 if (st_insert(ofl->ofl_dynstrtab, 2214 sdp->sd_name) == -1) 2215 return (S_ERROR); 2216 /* Include it in sort section? */ 2217 DYNSORT_COUNT(sdp, sym, type, ++); 2218 } 2219 } 2220 } 2221 } 2222 2223 /* 2224 * The GNU ld interprets the top bit of the 16-bit Versym value 2225 * (0x8000) as the "hidden" bit. If this bit is set, the linker 2226 * is supposed to act as if that symbol does not exist. The Solaris 2227 * linker does not support this mechanism, or the model of interface 2228 * evolution that it allows, but we honor it in GNU ld produced 2229 * objects in order to interoperate with them. 2230 * 2231 * Determine if we should honor the GNU hidden bit for this file. 2232 */ 2233 test_gnu_hidden_bit = ((ifl->ifl_flags & FLG_IF_GNUVER) != 0) && 2234 (ifl->ifl_versym != NULL); 2235 2236 /* 2237 * Now scan the global symbols entering them in the internal symbol 2238 * table or resolving them as necessary. 2239 */ 2240 sym = (Sym *)isc->is_indata->d_buf; 2241 sym += local; 2242 weak = 0; 2243 /* LINTED */ 2244 for (ndx = (int)local; ndx < total; sym++, ndx++) { 2245 const char *name; 2246 Word shndx, sdflags = 0; 2247 int shndx_bad = 0; 2248 2249 /* 2250 * Determine and validate the associated section index. 2251 */ 2252 if (symshndx && (sym->st_shndx == SHN_XINDEX)) { 2253 shndx = symshndx[ndx]; 2254 } else if ((shndx = sym->st_shndx) >= SHN_LORESERVE) { 2255 sdflags |= FLG_SY_SPECSEC; 2256 } else if (shndx > ifl->ifl_ehdr->e_shnum) { 2257 /* We need the name before we can issue error */ 2258 shndx_bad = 1; 2259 } 2260 2261 /* 2262 * Check if st_name has a valid value or not. 2263 */ 2264 if ((name = string(ofl, ifl, sym, strs, strsize, ndx, shndx, 2265 symsecndx, symsecname, strsecname, &sdflags)) == NULL) { 2266 ofl->ofl_flags |= FLG_OF_FATAL; 2267 continue; 2268 } 2269 2270 /* 2271 * Now that we have the name, if the section index 2272 * was bad, report it. 2273 */ 2274 if (shndx_bad) { 2275 eprintf(ofl->ofl_lml, ERR_WARNING, 2276 MSG_INTL(MSG_SYM_INVSHNDX), 2277 demangle_symname(name, symsecname, ndx), 2278 ifl->ifl_name, 2279 conv_sym_shndx(osabi, mach, sym->st_shndx, 2280 CONV_FMT_DECIMAL, &inv_buf)); 2281 continue; 2282 } 2283 2284 2285 /* 2286 * Test for the GNU hidden bit, and ignore symbols that 2287 * have it set. 2288 */ 2289 if (test_gnu_hidden_bit && 2290 ((ifl->ifl_versym[ndx] & 0x8000) != 0)) 2291 continue; 2292 2293 /* 2294 * The linker itself will generate symbols for _end, _etext, 2295 * _edata, _DYNAMIC and _PROCEDURE_LINKAGE_TABLE_, so don't 2296 * bother entering these symbols from shared objects. This 2297 * results in some wasted resolution processing, which is hard 2298 * to feel, but if nothing else, pollutes diagnostic relocation 2299 * output. 2300 */ 2301 if (name[0] && (etype == ET_DYN) && (sym->st_size == 0) && 2302 (ELF_ST_TYPE(sym->st_info) == STT_OBJECT) && 2303 (name[0] == '_') && ((name[1] == 'e') || 2304 (name[1] == 'D') || (name[1] == 'P')) && 2305 ((strcmp(name, MSG_ORIG(MSG_SYM_ETEXT_U)) == 0) || 2306 (strcmp(name, MSG_ORIG(MSG_SYM_EDATA_U)) == 0) || 2307 (strcmp(name, MSG_ORIG(MSG_SYM_END_U)) == 0) || 2308 (strcmp(name, MSG_ORIG(MSG_SYM_DYNAMIC_U)) == 0) || 2309 (strcmp(name, MSG_ORIG(MSG_SYM_PLKTBL_U)) == 0))) { 2310 ifl->ifl_oldndx[ndx] = 0; 2311 continue; 2312 } 2313 2314 /* 2315 * Determine and validate the symbols binding. 2316 */ 2317 bind = ELF_ST_BIND(sym->st_info); 2318 if ((bind != STB_GLOBAL) && (bind != STB_WEAK)) { 2319 eprintf(ofl->ofl_lml, ERR_WARNING, 2320 MSG_INTL(MSG_SYM_NONGLOB), 2321 demangle_symname(name, symsecname, ndx), 2322 ifl->ifl_name, 2323 conv_sym_info_bind(bind, 0, &inv_buf)); 2324 continue; 2325 } 2326 if (bind == STB_WEAK) 2327 weak++; 2328 2329 /* 2330 * If this symbol falls within the range of a section being 2331 * discarded, then discard the symbol itself. 2332 */ 2333 if (((sdflags & FLG_SY_SPECSEC) == 0) && 2334 (sym->st_shndx != SHN_UNDEF)) { 2335 Is_desc *isp; 2336 2337 if (shndx >= ifl->ifl_shnum) { 2338 /* 2339 * Carry our some basic sanity checks 2340 * The symbol will not be carried forward to 2341 * the output file, which won't be a problem 2342 * unless a relocation is required against it. 2343 */ 2344 eprintf(ofl->ofl_lml, ERR_WARNING, 2345 MSG_INTL(MSG_SYM_INVSHNDX), 2346 demangle_symname(name, symsecname, ndx), 2347 ifl->ifl_name, 2348 conv_sym_shndx(osabi, mach, sym->st_shndx, 2349 CONV_FMT_DECIMAL, &inv_buf)); 2350 continue; 2351 } 2352 2353 isp = ifl->ifl_isdesc[shndx]; 2354 if (isp && (isp->is_flags & FLG_IS_DISCARD)) { 2355 if ((sdp = 2356 libld_calloc(sizeof (Sym_desc), 1)) == NULL) 2357 return (S_ERROR); 2358 2359 /* 2360 * Create a dummy symbol entry so that if we 2361 * find any references to this discarded symbol 2362 * we can compensate. 2363 */ 2364 sdp->sd_name = name; 2365 sdp->sd_sym = sym; 2366 sdp->sd_file = ifl; 2367 sdp->sd_isc = isp; 2368 sdp->sd_flags = FLG_SY_ISDISC; 2369 ifl->ifl_oldndx[ndx] = sdp; 2370 2371 DBG_CALL(Dbg_syms_discarded(ofl->ofl_lml, sdp)); 2372 continue; 2373 } 2374 } 2375 2376 /* 2377 * If the symbol does not already exist in the internal symbol 2378 * table add it, otherwise resolve the conflict. If the symbol 2379 * from this file is kept, retain its symbol table index for 2380 * possible use in associating a global alias. 2381 */ 2382 /* LINTED */ 2383 hash = (Word)elf_hash((const char *)name); 2384 if ((sdp = ld_sym_find(name, hash, &where, ofl)) == NULL) { 2385 DBG_CALL(Dbg_syms_global(ofl->ofl_lml, ndx, name)); 2386 if ((sdp = ld_sym_enter(name, sym, hash, ifl, ofl, ndx, 2387 shndx, sdflags, 0, &where)) == (Sym_desc *)S_ERROR) 2388 return (S_ERROR); 2389 2390 } else if (ld_sym_resolve(sdp, sym, ifl, ofl, ndx, shndx, 2391 sdflags) == S_ERROR) 2392 return (S_ERROR); 2393 2394 /* 2395 * After we've compared a defined symbol in one shared 2396 * object, flag the symbol so we don't compare it again. 2397 */ 2398 if ((etype == ET_DYN) && (sym->st_shndx != SHN_UNDEF) && 2399 ((sdp->sd_flags & FLG_SY_SOFOUND) == 0)) 2400 sdp->sd_flags |= FLG_SY_SOFOUND; 2401 2402 /* 2403 * If the symbol is accepted from this file retain the symbol 2404 * index for possible use in aliasing. 2405 */ 2406 if (sdp->sd_file == ifl) 2407 sdp->sd_symndx = ndx; 2408 2409 ifl->ifl_oldndx[ndx] = sdp; 2410 2411 /* 2412 * If we've accepted a register symbol, continue to validate 2413 * it. 2414 */ 2415 if (sdp->sd_flags & FLG_SY_REGSYM) { 2416 Sym_desc *rsdp; 2417 2418 /* 2419 * The presence of FLG_SY_REGSYM means that 2420 * the pointers in ld_targ.t_ms are non-NULL. 2421 */ 2422 rsdp = (*ld_targ.t_ms.ms_reg_find)(sdp->sd_sym, ofl); 2423 if (rsdp == NULL) { 2424 if ((*ld_targ.t_ms.ms_reg_enter)(sdp, ofl) == 0) 2425 return (S_ERROR); 2426 } else if (rsdp != sdp) { 2427 (void) (*ld_targ.t_ms.ms_reg_check)(rsdp, 2428 sdp->sd_sym, sdp->sd_name, ifl, ofl); 2429 } 2430 } 2431 2432 /* 2433 * For a relocatable object, if this symbol is defined 2434 * and has non-zero length and references an address 2435 * within an associated section, then check its extents 2436 * to make sure the section boundaries encompass it. 2437 * If they don't, the ELF file is corrupt. Note that this 2438 * global symbol may have come from another file to satisfy 2439 * an UNDEF symbol of the same name from this one. In that 2440 * case, we don't check it, because it was already checked 2441 * as part of its own file. 2442 */ 2443 if (etype_rel && (sdp->sd_file == ifl)) { 2444 Sym *tsym = sdp->sd_sym; 2445 2446 if (SYM_LOC_BADADDR(sdp, tsym, 2447 ELF_ST_TYPE(tsym->st_info))) { 2448 issue_badaddr_msg(ifl, ofl, sdp, 2449 tsym, tsym->st_shndx); 2450 continue; 2451 } 2452 } 2453 } 2454 2455 /* 2456 * Associate weak (alias) symbols to their non-weak counterparts by 2457 * scaning the global symbols one more time. 2458 * 2459 * This association is needed when processing the symbols from a shared 2460 * object dependency when a a weak definition satisfies a reference: 2461 * 2462 * - When building a dynamic executable, if a referenced symbol is a 2463 * data item, the symbol data is copied to the executables address 2464 * space. In this copy-relocation case, we must also reassociate 2465 * the alias symbol with its new location in the executable. 2466 * 2467 * - If the referenced symbol is a function then we may need to 2468 * promote the symbols binding from undefined weak to undefined, 2469 * otherwise the run-time linker will not generate the correct 2470 * relocation error should the symbol not be found. 2471 * 2472 * Weak alias association is also required when a local dynsym table 2473 * is being created. This table should only contain one instance of a 2474 * symbol that is associated to a given address. 2475 * 2476 * The true association between a weak/strong symbol pair is that both 2477 * symbol entries are identical, thus first we create a sorted symbol 2478 * list keyed off of the symbols section index and value. If the symbol 2479 * belongs to the same section and has the same value, then the chances 2480 * are that the rest of the symbols data is the same. This list is then 2481 * scanned for weak symbols, and if one is found then any strong 2482 * association will exist in the entries that follow. Thus we just have 2483 * to scan one (typically a single alias) or more (in the uncommon 2484 * instance of multiple weak to strong associations) entries to 2485 * determine if a match exists. 2486 */ 2487 if (weak && (OFL_ALLOW_LDYNSYM(ofl) || (etype == ET_DYN)) && 2488 (total > local)) { 2489 static Sym_desc **sort; 2490 static size_t osize = 0; 2491 size_t nsize = (total - local) * sizeof (Sym_desc *); 2492 2493 /* 2494 * As we might be processing many input files, and many symbols, 2495 * try and reuse a static sort buffer. Note, presently we're 2496 * playing the game of never freeing any buffers as there's a 2497 * belief this wastes time. 2498 */ 2499 if ((osize == 0) || (nsize > osize)) { 2500 if ((sort = libld_malloc(nsize)) == NULL) 2501 return (S_ERROR); 2502 osize = nsize; 2503 } 2504 (void) memcpy((void *)sort, &ifl->ifl_oldndx[local], nsize); 2505 2506 qsort(sort, (total - local), sizeof (Sym_desc *), compare); 2507 2508 for (ndx = 0; ndx < (total - local); ndx++) { 2509 Sym_desc *wsdp = sort[ndx]; 2510 Sym *wsym; 2511 int sndx; 2512 2513 /* 2514 * Ignore any empty symbol descriptor, or the case where 2515 * the symbol has been resolved to a different file. 2516 */ 2517 if ((wsdp == NULL) || (wsdp->sd_file != ifl)) 2518 continue; 2519 2520 wsym = wsdp->sd_sym; 2521 2522 if ((wsym->st_shndx == SHN_UNDEF) || 2523 (wsdp->sd_flags & FLG_SY_SPECSEC) || 2524 (ELF_ST_BIND(wsym->st_info) != STB_WEAK)) 2525 continue; 2526 2527 /* 2528 * We have a weak symbol, if it has a strong alias it 2529 * will have been sorted to one of the following sort 2530 * table entries. Note that we could have multiple weak 2531 * symbols aliased to one strong (if this occurs then 2532 * the strong symbol only maintains one alias back to 2533 * the last weak). 2534 */ 2535 for (sndx = ndx + 1; sndx < (total - local); sndx++) { 2536 Sym_desc *ssdp = sort[sndx]; 2537 Sym *ssym; 2538 int w_dynbits, s_dynbits; 2539 2540 /* 2541 * Ignore any empty symbol descriptor, or the 2542 * case where the symbol has been resolved to a 2543 * different file. 2544 */ 2545 if ((ssdp == NULL) || (ssdp->sd_file != ifl)) 2546 continue; 2547 2548 ssym = ssdp->sd_sym; 2549 2550 if (ssym->st_shndx == SHN_UNDEF) 2551 continue; 2552 2553 if ((ssym->st_shndx != wsym->st_shndx) || 2554 (ssym->st_value != wsym->st_value)) 2555 break; 2556 2557 if ((ssym->st_size != wsym->st_size) || 2558 (ssdp->sd_flags & FLG_SY_SPECSEC) || 2559 (ELF_ST_BIND(ssym->st_info) == STB_WEAK)) 2560 continue; 2561 2562 /* 2563 * If a sharable object, set link fields so 2564 * that they reference each other.` 2565 */ 2566 if (etype == ET_DYN) { 2567 ssdp->sd_aux->sa_linkndx = 2568 (Word)wsdp->sd_symndx; 2569 wsdp->sd_aux->sa_linkndx = 2570 (Word)ssdp->sd_symndx; 2571 } 2572 2573 /* 2574 * Determine which of these two symbols go into 2575 * the sort section. If a mapfile has made 2576 * explicit settings of the FLG_SY_*DYNSORT 2577 * flags for both symbols, then we do what they 2578 * say. If one has the DYNSORT flags set, we 2579 * set the NODYNSORT bit in the other. And if 2580 * neither has an explicit setting, then we 2581 * favor the weak symbol because they usually 2582 * lack the leading underscore. 2583 */ 2584 w_dynbits = wsdp->sd_flags & 2585 (FLG_SY_DYNSORT | FLG_SY_NODYNSORT); 2586 s_dynbits = ssdp->sd_flags & 2587 (FLG_SY_DYNSORT | FLG_SY_NODYNSORT); 2588 if (!(w_dynbits && s_dynbits)) { 2589 if (s_dynbits) { 2590 if (s_dynbits == FLG_SY_DYNSORT) 2591 wsdp->sd_flags |= 2592 FLG_SY_NODYNSORT; 2593 } else if (w_dynbits != 2594 FLG_SY_NODYNSORT) { 2595 ssdp->sd_flags |= 2596 FLG_SY_NODYNSORT; 2597 } 2598 } 2599 break; 2600 } 2601 } 2602 } 2603 return (1); 2604 2605 #undef SYM_LOC_BADADDR 2606 } 2607 2608 /* 2609 * Add an undefined symbol to the symbol table. The reference originates from 2610 * the location identifed by the message id (mid). These references can 2611 * originate from command line options such as -e, -u, -initarray, etc. 2612 * (identified with MSG_INTL(MSG_STR_COMMAND)), or from internally generated 2613 * TLS relocation references (identified with MSG_INTL(MSG_STR_TLSREL)). 2614 */ 2615 Sym_desc * 2616 ld_sym_add_u(const char *name, Ofl_desc *ofl, Msg mid) 2617 { 2618 Sym *sym; 2619 Ifl_desc *ifl = NULL, *_ifl; 2620 Sym_desc *sdp; 2621 Word hash; 2622 Aliste idx; 2623 avl_index_t where; 2624 const char *reference = MSG_INTL(mid); 2625 2626 /* 2627 * As an optimization, determine whether we've already generated this 2628 * reference. If the symbol doesn't already exist we'll create it. 2629 * Or if the symbol does exist from a different source, we'll resolve 2630 * the conflict. 2631 */ 2632 /* LINTED */ 2633 hash = (Word)elf_hash(name); 2634 if ((sdp = ld_sym_find(name, hash, &where, ofl)) != NULL) { 2635 if ((sdp->sd_sym->st_shndx == SHN_UNDEF) && 2636 (sdp->sd_file->ifl_name == reference)) 2637 return (sdp); 2638 } 2639 2640 /* 2641 * Determine whether a pseudo input file descriptor exists to represent 2642 * the command line, as any global symbol needs an input file descriptor 2643 * during any symbol resolution (refer to map_ifl() which provides a 2644 * similar method for adding symbols from mapfiles). 2645 */ 2646 for (APLIST_TRAVERSE(ofl->ofl_objs, idx, _ifl)) 2647 if (strcmp(_ifl->ifl_name, reference) == 0) { 2648 ifl = _ifl; 2649 break; 2650 } 2651 2652 /* 2653 * If no descriptor exists create one. 2654 */ 2655 if (ifl == NULL) { 2656 if ((ifl = libld_calloc(sizeof (Ifl_desc), 1)) == NULL) 2657 return ((Sym_desc *)S_ERROR); 2658 ifl->ifl_name = reference; 2659 ifl->ifl_flags = FLG_IF_NEEDED | FLG_IF_FILEREF; 2660 if ((ifl->ifl_ehdr = libld_calloc(sizeof (Ehdr), 1)) == NULL) 2661 return ((Sym_desc *)S_ERROR); 2662 ifl->ifl_ehdr->e_type = ET_REL; 2663 2664 if (aplist_append(&ofl->ofl_objs, ifl, AL_CNT_OFL_OBJS) == NULL) 2665 return ((Sym_desc *)S_ERROR); 2666 } 2667 2668 /* 2669 * Allocate a symbol structure and add it to the global symbol table. 2670 */ 2671 if ((sym = libld_calloc(sizeof (Sym), 1)) == NULL) 2672 return ((Sym_desc *)S_ERROR); 2673 sym->st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); 2674 sym->st_shndx = SHN_UNDEF; 2675 2676 DBG_CALL(Dbg_syms_process(ofl->ofl_lml, ifl)); 2677 if (sdp == NULL) { 2678 DBG_CALL(Dbg_syms_global(ofl->ofl_lml, 0, name)); 2679 if ((sdp = ld_sym_enter(name, sym, hash, ifl, ofl, 0, SHN_UNDEF, 2680 0, 0, &where)) == (Sym_desc *)S_ERROR) 2681 return ((Sym_desc *)S_ERROR); 2682 } else if (ld_sym_resolve(sdp, sym, ifl, ofl, 0, 2683 SHN_UNDEF, 0) == S_ERROR) 2684 return ((Sym_desc *)S_ERROR); 2685 2686 sdp->sd_flags &= ~FLG_SY_CLEAN; 2687 sdp->sd_flags |= FLG_SY_CMDREF; 2688 2689 return (sdp); 2690 } 2691 2692 /* 2693 * STT_SECTION symbols have their st_name field set to NULL, and consequently 2694 * have no name. Generate a name suitable for diagnostic use for such a symbol. 2695 * The resulting name will be of the form: 2696 * 2697 * "XXX (section)" 2698 * 2699 * where XXX is the name of the section. 2700 * 2701 * Diagnostics for STT_SECTION symbols tend to come in clusters, 2702 * so we use a static variable to retain the last string we generate. If 2703 * another one comes along for the same section before some other section 2704 * intervenes, we will reuse the string. 2705 * 2706 * entry: 2707 * isc - Input section assocated with the symbol. 2708 * fmt - NULL, or format string to use. 2709 * 2710 * exit: 2711 * Returns the allocated string, or NULL on allocation failure. 2712 */ 2713 const const char * 2714 ld_stt_section_sym_name(Is_desc *isp) 2715 { 2716 static const char *last_fmt; 2717 static Is_desc *last_isp = NULL; 2718 static char *namestr; 2719 2720 const char *fmt; 2721 size_t len; 2722 2723 if ((isp != NULL) && (isp->is_name != NULL)) { 2724 fmt = (isp->is_flags & FLG_IS_GNSTRMRG) ? 2725 MSG_INTL(MSG_STR_SECTION_MSTR) : MSG_INTL(MSG_STR_SECTION); 2726 2727 if ((last_isp == isp) && (last_fmt == fmt)) 2728 return (namestr); 2729 2730 len = strlen(fmt) + strlen(isp->is_name) + 1; 2731 2732 if ((namestr = libld_malloc(len)) == 0) 2733 return (NULL); 2734 (void) snprintf(namestr, len, fmt, isp->is_name); 2735 2736 /* Remember for next time */ 2737 last_fmt = fmt; 2738 last_isp = isp; 2739 2740 return (namestr); 2741 } 2742 2743 return (NULL); 2744 } 2745