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 2007 Sun Microsystems, Inc. All rights reserved. 28 * Use is subject to license terms. 29 */ 30 #pragma ident "%Z%%M% %I% %E% SMI" 31 32 /* 33 * Symbol table management routines 34 */ 35 #include <stdio.h> 36 #include <string.h> 37 #include <debug.h> 38 #include "msg.h" 39 #include "_libld.h" 40 41 /* 42 * AVL tree comparator function: 43 * 44 * The primary key is the 'sa_hashval' with a secondary 45 * key of the symbol name itself. 46 */ 47 int 48 ld_sym_avl_comp(const void *elem1, const void *elem2) 49 { 50 int res; 51 Sym_avlnode *sav1 = (Sym_avlnode *)elem1; 52 Sym_avlnode *sav2 = (Sym_avlnode *)elem2; 53 54 res = sav1->sav_hash - sav2->sav_hash; 55 56 if (res < 0) 57 return (-1); 58 if (res > 0) 59 return (1); 60 61 /* 62 * Hash is equal - now compare name 63 */ 64 res = strcmp(sav1->sav_name, sav2->sav_name); 65 if (res == 0) 66 return (0); 67 if (res > 0) 68 return (1); 69 return (-1); 70 } 71 72 73 /* 74 * Focal point for verifying symbol names. 75 */ 76 static const char * 77 string(Ofl_desc *ofl, Ifl_desc *ifl, Sym *sym, const char *strs, size_t strsize, 78 int symndx, Word shndx, const char *symsecname, const char *strsecname, 79 Word *flags) 80 { 81 const char *regname; 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 symsecname, symndx, EC_XWORD(name)); 89 return (0); 90 } 91 if (name >= (Word)strsize) { 92 eprintf(ofl->ofl_lml, ERR_FATAL, 93 MSG_INTL(MSG_FIL_EXCSTRTABLE), ifl->ifl_name, 94 symsecname, symndx, EC_XWORD(name), 95 strsecname, EC_XWORD(strsize)); 96 return (0); 97 } 98 } 99 100 /* 101 * Determine if we're dealing with a register and if so validate it. 102 * If it's a scratch register, a fabricated name will be returned. 103 */ 104 if ((regname = ld_is_regsym(ofl, ifl, sym, strs, symndx, shndx, 105 symsecname, flags)) == (const char *)S_ERROR) { 106 return (0); 107 } 108 if (regname) 109 return (regname); 110 111 /* 112 * If this isn't a register, but we have a global symbol with a null 113 * name, we're not going to be able to hash this, search for it, or 114 * do anything interesting. However, we've been accepting a symbol of 115 * this kind for ages now, so give the user a warning (rather than a 116 * fatal error), just in case this instance exists somewhere in the 117 * world and hasn't, as yet, been a problem. 118 */ 119 if ((name == 0) && (ELF_ST_BIND(sym->st_info) != STB_LOCAL)) { 120 eprintf(ofl->ofl_lml, ERR_WARNING, MSG_INTL(MSG_FIL_NONAMESYM), 121 ifl->ifl_name, symsecname, symndx, EC_XWORD(name)); 122 } 123 return (strs + name); 124 } 125 126 /* 127 * Shared objects can be built that define specific symbols that can not be 128 * directly bound to. These objects have a syminfo section (and an associated 129 * DF_1_NODIRECT dynamic flags entry). Scan this table looking for symbols 130 * that can't be bound to directly, and if this files symbol is presently 131 * referenced, mark it so that we don't directly bind to it. 132 */ 133 uintptr_t 134 ld_sym_nodirect(Is_desc *isp, Ifl_desc *ifl, Ofl_desc *ofl) 135 { 136 Shdr *sifshdr, *symshdr; 137 Syminfo *sifdata; 138 Sym *symdata; 139 char *strdata; 140 ulong_t cnt, _cnt; 141 142 /* 143 * Get the syminfo data, and determine the number of entries. 144 */ 145 sifshdr = isp->is_shdr; 146 sifdata = (Syminfo *)isp->is_indata->d_buf; 147 cnt = sifshdr->sh_size / sifshdr->sh_entsize; 148 149 /* 150 * Get the associated symbol table. 151 */ 152 symshdr = ifl->ifl_isdesc[sifshdr->sh_link]->is_shdr; 153 symdata = ifl->ifl_isdesc[sifshdr->sh_link]->is_indata->d_buf; 154 155 /* 156 * Get the string table associated with the symbol table. 157 */ 158 strdata = ifl->ifl_isdesc[symshdr->sh_link]->is_indata->d_buf; 159 160 /* 161 * Traverse the syminfo data for symbols that can't be directly 162 * bound to. 163 */ 164 for (_cnt = 1, sifdata++; _cnt < cnt; _cnt++, sifdata++) { 165 Sym *sym; 166 char *str; 167 Sym_desc *sdp; 168 169 if (((sifdata->si_flags & SYMINFO_FLG_NOEXTDIRECT) == 0) || 170 (sifdata->si_boundto < SYMINFO_BT_LOWRESERVE)) 171 continue; 172 173 sym = (Sym *)(symdata + _cnt); 174 str = (char *)(strdata + sym->st_name); 175 176 if (sdp = ld_sym_find(str, SYM_NOHASH, 0, ofl)) { 177 if (ifl != sdp->sd_file) 178 continue; 179 180 sdp->sd_flags1 &= ~FLG_SY1_DIR; 181 sdp->sd_flags1 |= FLG_SY1_NDIR; 182 } 183 } 184 return (0); 185 } 186 187 /* 188 * If, during symbol processing, it is necessary to update a local symbols 189 * contents before we have generated the symbol tables in the output image, 190 * create a new symbol structure and copy the original symbol contents. While 191 * we are processing the input files, their local symbols are part of the 192 * read-only mapped image. Commonly, these symbols are copied to the new output 193 * file image and then updated to reflect their new address and any change in 194 * attributes. However, sometimes during relocation counting, it is necessary 195 * to adjust the symbols information. This routine provides for the generation 196 * of a new symbol image so that this update can be performed. 197 * All global symbols are copied to an internal symbol table to improve locality 198 * of reference and hence performance, and thus this copying is not necessary. 199 */ 200 uintptr_t 201 ld_sym_copy(Sym_desc *sdp) 202 { 203 Sym *nsym; 204 205 if (sdp->sd_flags & FLG_SY_CLEAN) { 206 if ((nsym = libld_malloc(sizeof (Sym))) == 0) 207 return (S_ERROR); 208 *nsym = *(sdp->sd_sym); 209 sdp->sd_sym = nsym; 210 sdp->sd_flags &= ~FLG_SY_CLEAN; 211 } 212 return (1); 213 } 214 215 /* 216 * Finds a given name in the link editors internal symbol table. If no 217 * hash value is specified it is calculated. A pointer to the located 218 * Sym_desc entry is returned, or NULL if the symbol is not found. 219 */ 220 Sym_desc * 221 ld_sym_find(const char *name, Word hash, avl_index_t *where, Ofl_desc *ofl) 222 { 223 Sym_avlnode qsav; 224 Sym_avlnode *sav; 225 226 if (hash == SYM_NOHASH) 227 /* LINTED */ 228 hash = (Word)elf_hash((const char *)name); 229 qsav.sav_hash = hash; 230 qsav.sav_name = name; 231 232 /* 233 * Perform search for symbol in AVL tree. Note that the 'where' field 234 * is passed in from the caller. If a 'where' is present, it can be 235 * used in subsequent 'sym_enter()' calls if required. 236 */ 237 sav = avl_find(&ofl->ofl_symavl, &qsav, where); 238 239 /* 240 * If symbol was not found in the avl tree, return null to show that. 241 */ 242 if (sav == 0) 243 return (0); 244 245 /* 246 * Return symbol found. 247 */ 248 return (sav->sav_symdesc); 249 } 250 251 252 /* 253 * Enter a new symbol into the link editors internal symbol table. 254 * If the symbol is from an input file, information regarding the input file 255 * and input section is also recorded. Otherwise (file == NULL) the symbol 256 * has been internally generated (ie. _etext, _edata, etc.). 257 */ 258 Sym_desc * 259 ld_sym_enter(const char *name, Sym *osym, Word hash, Ifl_desc *ifl, 260 Ofl_desc *ofl, Word ndx, Word shndx, Word sdflags, Half sdflags1, 261 avl_index_t *where) 262 { 263 Sym_desc *sdp; 264 Sym_aux *sap; 265 Sym_avlnode *savl; 266 char *_name; 267 Sym *nsym; 268 Half etype; 269 avl_index_t _where; 270 271 /* 272 * Establish the file type. 273 */ 274 if (ifl) 275 etype = ifl->ifl_ehdr->e_type; 276 else 277 etype = ET_NONE; 278 279 ofl->ofl_entercnt++; 280 281 /* 282 * Allocate a Sym Descriptor, Auxiliary Descriptor, and a Sym AVLNode - 283 * contiguously. 284 */ 285 if ((savl = libld_calloc(sizeof (Sym_avlnode) + sizeof (Sym_desc) + 286 sizeof (Sym_aux), 1)) == 0) 287 return ((Sym_desc *)S_ERROR); 288 sdp = (Sym_desc *)((uintptr_t)savl + sizeof (Sym_avlnode)); 289 sap = (Sym_aux *)((uintptr_t)sdp + sizeof (Sym_desc)); 290 291 savl->sav_symdesc = sdp; 292 sdp->sd_file = ifl; 293 sdp->sd_aux = sap; 294 savl->sav_hash = sap->sa_hash = hash; 295 296 297 /* 298 * Copy the symbol table entry from the input file into the internal 299 * entry and have the symbol descriptor use it. 300 */ 301 sdp->sd_sym = nsym = &sap->sa_sym; 302 *nsym = *osym; 303 sdp->sd_shndx = shndx; 304 sdp->sd_flags |= sdflags; 305 sdp->sd_flags1 |= sdflags1; 306 307 if ((_name = libld_malloc(strlen(name) + 1)) == 0) 308 return ((Sym_desc *)S_ERROR); 309 savl->sav_name = sdp->sd_name = (const char *)strcpy(_name, name); 310 311 /* 312 * Enter Symbol in AVL tree. 313 */ 314 if (where == 0) { 315 /* LINTED */ 316 Sym_avlnode *_savl; 317 /* 318 * If a previous ld_sym_find() hasn't initialized 'where' do it 319 * now. 320 */ 321 where = &_where; 322 _savl = avl_find(&ofl->ofl_symavl, savl, where); 323 assert(_savl == 0); 324 } 325 avl_insert(&ofl->ofl_symavl, savl, *where); 326 327 /* 328 * Record the section index. This is possible because the 329 * `ifl_isdesc' table is filled before we start symbol processing. 330 */ 331 if ((sdflags & FLG_SY_SPECSEC) || (nsym->st_shndx == SHN_UNDEF)) 332 sdp->sd_isc = NULL; 333 else { 334 sdp->sd_isc = ifl->ifl_isdesc[shndx]; 335 336 /* 337 * If this symbol is from a relocatable object, make sure that 338 * it is still associated with a section. For example, an 339 * unknown section type (SHT_NULL) would have been rejected on 340 * input with a warning. Here, we make the use of the symbol 341 * fatal. A symbol descriptor is still returned, so that the 342 * caller can continue processing all symbols, and hence flush 343 * out as many error conditions as possible. 344 */ 345 if ((etype == ET_REL) && (sdp->sd_isc == 0)) { 346 eprintf(ofl->ofl_lml, ERR_FATAL, 347 MSG_INTL(MSG_SYM_INVSEC), name, ifl->ifl_name, 348 EC_XWORD(shndx)); 349 ofl->ofl_flags |= FLG_OF_FATAL; 350 return (sdp); 351 } 352 } 353 354 /* 355 * Mark any COMMON symbols as 'tentative'. 356 */ 357 if (sdflags & FLG_SY_SPECSEC) { 358 if (nsym->st_shndx == SHN_COMMON) 359 sdp->sd_flags |= FLG_SY_TENTSYM; 360 #if defined(__x86) && defined(_ELF64) 361 else if (nsym->st_shndx == SHN_X86_64_LCOMMON) 362 sdp->sd_flags |= FLG_SY_TENTSYM; 363 #endif 364 } 365 366 /* 367 * Establish the symbols reference & visibility. 368 */ 369 if ((etype == ET_NONE) || (etype == ET_REL)) { 370 sdp->sd_ref = REF_REL_NEED; 371 372 /* 373 * Under -Bnodirect, all exported interfaces that have not 374 * explicitly been defined protected or directly bound to, are 375 * tagged to prevent direct binding. 376 */ 377 if ((ofl->ofl_flags1 & FLG_OF1_ALNODIR) && 378 ((sdp->sd_flags1 & (FLG_SY1_PROT | FLG_SY1_DIR)) == 0) && 379 (nsym->st_shndx != SHN_UNDEF)) { 380 sdp->sd_flags1 |= FLG_SY1_NDIR; 381 } 382 } else { 383 sdp->sd_ref = REF_DYN_SEEN; 384 385 /* 386 * Record the binding file for this symbol in the sa_bindto 387 * field. If this symbol is ever overridden by a REF_REL_NEED 388 * definition, sa_bindto is used when building a 'translator'. 389 */ 390 if (nsym->st_shndx != SHN_UNDEF) 391 sdp->sd_aux->sa_bindto = ifl; 392 393 /* 394 * If this is a protected symbol, mark it. 395 */ 396 if (ELF_ST_VISIBILITY(nsym->st_other) == STV_PROTECTED) 397 sdp->sd_flags |= FLG_SY_PROT; 398 399 /* 400 * Mask out any visibility info from a DYN symbol. 401 */ 402 nsym->st_other = nsym->st_other & ~MSK_SYM_VISIBILITY; 403 404 /* 405 * If the new symbol is from a shared library and it 406 * is associated with a SHT_NOBITS section then this 407 * symbol originated from a tentative symbol. 408 */ 409 if (sdp->sd_isc && 410 (sdp->sd_isc->is_shdr->sh_type == SHT_NOBITS)) 411 sdp->sd_flags |= FLG_SY_TENTSYM; 412 } 413 414 /* 415 * Reclassify any SHN_SUNW_IGNORE symbols to SHN_UNDEF so as to 416 * simplify future processing. 417 */ 418 if (nsym->st_shndx == SHN_SUNW_IGNORE) { 419 sdp->sd_shndx = shndx = SHN_UNDEF; 420 sdp->sd_flags |= FLG_SY_REDUCED; 421 sdp->sd_flags1 |= 422 (FLG_SY1_IGNORE | FLG_SY1_LOCL | FLG_SY1_ELIM); 423 } 424 425 /* 426 * If this is an undefined, or common symbol from a relocatable object 427 * determine whether it is a global or weak reference (see build_osym(), 428 * where REF_DYN_NEED definitions are returned back to undefines). 429 */ 430 if ((etype == ET_REL) && 431 (ELF_ST_BIND(nsym->st_info) == STB_GLOBAL) && 432 ((nsym->st_shndx == SHN_UNDEF) || ((sdflags & FLG_SY_SPECSEC) && 433 #if defined(__x86) && defined(_ELF64) 434 ((nsym->st_shndx == SHN_COMMON) || 435 (nsym->st_shndx == SHN_X86_64_LCOMMON))))) 436 #else 437 /* BEGIN CSTYLED */ 438 (nsym->st_shndx == SHN_COMMON)))) 439 /* END CSTYLED */ 440 #endif 441 sdp->sd_flags |= FLG_SY_GLOBREF; 442 443 /* 444 * Record the input filename on the referenced or defined files list 445 * for possible later diagnostics. The `sa_rfile' pointer contains the 446 * name of the file that first referenced this symbol and is used to 447 * generate undefined symbol diagnostics (refer to sym_undef_entry()). 448 * Note that this entry can be overridden if a reference from a 449 * relocatable object is found after a reference from a shared object 450 * (refer to sym_override()). 451 * The `sa_dfiles' list is used to maintain the list of files that 452 * define the same symbol. This list can be used for two reasons: 453 * 454 * o To save the first definition of a symbol that is not available 455 * for this link-edit. 456 * 457 * o To save all definitions of a symbol when the -m option is in 458 * effect. This is optional as it is used to list multiple 459 * (interposed) definitions of a symbol (refer to ldmap_out()), 460 * and can be quite expensive. 461 */ 462 if (nsym->st_shndx == SHN_UNDEF) { 463 sap->sa_rfile = ifl->ifl_name; 464 } else { 465 if (sdp->sd_ref == REF_DYN_SEEN) { 466 /* 467 * A symbol is determined to be unavailable if it 468 * belongs to a version of a shared object that this 469 * user does not wish to use, or if it belongs to an 470 * implicit shared object. 471 */ 472 if (ifl->ifl_vercnt) { 473 Ver_index *vip; 474 Half vndx = ifl->ifl_versym[ndx]; 475 476 sap->sa_dverndx = vndx; 477 vip = &ifl->ifl_verndx[vndx]; 478 if (!(vip->vi_flags & FLG_VER_AVAIL)) { 479 sdp->sd_flags |= FLG_SY_NOTAVAIL; 480 sap->sa_vfile = ifl->ifl_name; 481 } 482 } 483 if (!(ifl->ifl_flags & FLG_IF_NEEDED)) 484 sdp->sd_flags |= FLG_SY_NOTAVAIL; 485 486 } else if (etype == ET_REL) { 487 /* 488 * If this symbol has been obtained from a versioned 489 * input relocatable object then the new symbol must be 490 * promoted to the versioning of the output file. 491 */ 492 if (ifl->ifl_versym) 493 ld_vers_promote(sdp, ndx, ifl, ofl); 494 } 495 496 if ((ofl->ofl_flags & FLG_OF_GENMAP) && 497 ((sdflags & FLG_SY_SPECSEC) == 0)) 498 if (list_appendc(&sap->sa_dfiles, ifl->ifl_name) == 0) 499 return ((Sym_desc *)S_ERROR); 500 } 501 502 DBG_CALL(Dbg_syms_entered(ofl, nsym, sdp)); 503 return (sdp); 504 } 505 506 /* 507 * Add a special symbol to the symbol table. Takes special symbol name with 508 * and without underscores. This routine is called, after all other symbol 509 * resolution has completed, to generate a reserved absolute symbol (the 510 * underscore version). Special symbols are updated with the appropriate 511 * values in update_osym(). If the user has already defined this symbol 512 * issue a warning and leave the symbol as is. If the non-underscore symbol 513 * is referenced then turn it into a weak alias of the underscored symbol. 514 * 515 * The bits in flags_u are OR'd into the flags field of the symbol 516 * for the underscored symbol. 517 * 518 * If this is a global symbol, and it hasn't explicitly been defined as being 519 * directly bound to, indicate that it can't be directly bound to. 520 * Historically, most special symbols only have meaning to the object in which 521 * they exist, however, they've always been global. To ensure compatibility 522 * with any unexpected use presently in effect, ensure these symbols don't get 523 * directly bound to. Note, that establishing this state here isn't sufficient 524 * to create a syminfo table, only if a syminfo table is being created by some 525 * other symbol directives will the nodirect binding be recorded. This ensures 526 * we don't create syminfo sections for all objects we create, as this might add 527 * unnecessary bloat to users who haven't explicitly requested extra symbol 528 * information. 529 */ 530 static uintptr_t 531 sym_add_spec(const char *name, const char *uname, Word sdaux_id, 532 Word flags_u, Half flags1, Ofl_desc *ofl) 533 { 534 Sym_desc *sdp; 535 Sym_desc *usdp; 536 Sym *sym; 537 Word hash; 538 avl_index_t where; 539 540 /* LINTED */ 541 hash = (Word)elf_hash(uname); 542 if (usdp = ld_sym_find(uname, hash, &where, ofl)) { 543 /* 544 * If the underscore symbol exists and is undefined, or was 545 * defined in a shared library, convert it to a local symbol. 546 * Otherwise leave it as is and warn the user. 547 */ 548 if ((usdp->sd_shndx == SHN_UNDEF) || 549 (usdp->sd_ref != REF_REL_NEED)) { 550 usdp->sd_ref = REF_REL_NEED; 551 usdp->sd_shndx = usdp->sd_sym->st_shndx = SHN_ABS; 552 usdp->sd_flags |= FLG_SY_SPECSEC | flags_u; 553 usdp->sd_sym->st_info = 554 ELF_ST_INFO(STB_GLOBAL, STT_OBJECT); 555 usdp->sd_isc = NULL; 556 usdp->sd_sym->st_size = 0; 557 usdp->sd_sym->st_value = 0; 558 /* LINTED */ 559 usdp->sd_aux->sa_symspec = (Half)sdaux_id; 560 561 /* 562 * If a user hasn't specifically indicated that the 563 * scope of this symbol be made local, then leave it 564 * as global (ie. prevent automatic scoping). The GOT 565 * should be defined protected, whereas all other 566 * special symbols are tagged as no-direct. 567 */ 568 if (!(usdp->sd_flags1 & FLG_SY1_LOCL) && 569 (flags1 & FLG_SY1_GLOB)) { 570 usdp->sd_aux->sa_overndx = VER_NDX_GLOBAL; 571 if (sdaux_id == SDAUX_ID_GOT) { 572 usdp->sd_flags1 &= ~FLG_SY1_NDIR; 573 usdp->sd_flags1 |= FLG_SY1_PROT; 574 usdp->sd_sym->st_other = STV_PROTECTED; 575 } else if ( 576 ((usdp->sd_flags1 & FLG_SY1_DIR) == 0) && 577 ((ofl->ofl_flags & FLG_OF_SYMBOLIC) == 0)) { 578 usdp->sd_flags1 |= FLG_SY1_NDIR; 579 } 580 } 581 usdp->sd_flags1 |= flags1; 582 583 /* 584 * If the reference originated from a mapfile ensure 585 * we mark the symbol as used. 586 */ 587 if (usdp->sd_flags & FLG_SY_MAPREF) 588 usdp->sd_flags |= FLG_SY_MAPUSED; 589 590 DBG_CALL(Dbg_syms_updated(ofl, usdp, uname)); 591 } else 592 eprintf(ofl->ofl_lml, ERR_WARNING, 593 MSG_INTL(MSG_SYM_RESERVE), uname, 594 usdp->sd_file->ifl_name); 595 } else { 596 /* 597 * If the symbol does not exist create it. 598 */ 599 if ((sym = libld_calloc(sizeof (Sym), 1)) == 0) 600 return (S_ERROR); 601 sym->st_shndx = SHN_ABS; 602 sym->st_info = ELF_ST_INFO(STB_GLOBAL, STT_OBJECT); 603 sym->st_size = 0; 604 sym->st_value = 0; 605 DBG_CALL(Dbg_syms_created(ofl->ofl_lml, uname)); 606 if ((usdp = ld_sym_enter(uname, sym, hash, (Ifl_desc *)NULL, 607 ofl, 0, SHN_ABS, FLG_SY_SPECSEC | flags_u, 0, &where)) == 608 (Sym_desc *)S_ERROR) 609 return (S_ERROR); 610 usdp->sd_ref = REF_REL_NEED; 611 /* LINTED */ 612 usdp->sd_aux->sa_symspec = (Half)sdaux_id; 613 614 usdp->sd_aux->sa_overndx = VER_NDX_GLOBAL; 615 616 if (sdaux_id == SDAUX_ID_GOT) { 617 usdp->sd_flags1 |= FLG_SY1_PROT; 618 usdp->sd_sym->st_other = STV_PROTECTED; 619 } else if ((flags1 & FLG_SY1_GLOB) && 620 ((ofl->ofl_flags & FLG_OF_SYMBOLIC) == 0)) { 621 usdp->sd_flags1 |= FLG_SY1_NDIR; 622 } 623 usdp->sd_flags1 |= flags1; 624 } 625 626 if (name && (sdp = ld_sym_find(name, SYM_NOHASH, 0, ofl)) && 627 (sdp->sd_sym->st_shndx == SHN_UNDEF)) { 628 uchar_t bind; 629 630 /* 631 * If the non-underscore symbol exists and is undefined 632 * convert it to be a local. If the underscore has 633 * sa_symspec set (ie. it was created above) then simulate this 634 * as a weak alias. 635 */ 636 sdp->sd_ref = REF_REL_NEED; 637 sdp->sd_shndx = sdp->sd_sym->st_shndx = SHN_ABS; 638 sdp->sd_flags |= FLG_SY_SPECSEC; 639 sdp->sd_isc = NULL; 640 sdp->sd_sym->st_size = 0; 641 sdp->sd_sym->st_value = 0; 642 /* LINTED */ 643 sdp->sd_aux->sa_symspec = (Half)sdaux_id; 644 if (usdp->sd_aux->sa_symspec) { 645 usdp->sd_aux->sa_linkndx = 0; 646 sdp->sd_aux->sa_linkndx = 0; 647 bind = STB_WEAK; 648 } else 649 bind = STB_GLOBAL; 650 sdp->sd_sym->st_info = ELF_ST_INFO(bind, STT_OBJECT); 651 652 /* 653 * If a user hasn't specifically indicated the scope of this 654 * symbol be made local then leave it as global (ie. prevent 655 * automatic scoping). The GOT should be defined protected, 656 * whereas all other special symbols are tagged as no-direct. 657 */ 658 if (!(sdp->sd_flags1 & FLG_SY1_LOCL) && 659 (flags1 & FLG_SY1_GLOB)) { 660 sdp->sd_aux->sa_overndx = VER_NDX_GLOBAL; 661 if (sdaux_id == SDAUX_ID_GOT) { 662 sdp->sd_flags1 &= ~FLG_SY1_NDIR; 663 sdp->sd_flags1 |= FLG_SY1_PROT; 664 sdp->sd_sym->st_other = STV_PROTECTED; 665 } else if (((sdp->sd_flags1 & FLG_SY1_DIR) == 0) && 666 ((ofl->ofl_flags & FLG_OF_SYMBOLIC) == 0)) { 667 sdp->sd_flags1 |= FLG_SY1_NDIR; 668 } 669 } 670 sdp->sd_flags1 |= flags1; 671 672 /* 673 * If the reference originated from a mapfile ensure 674 * we mark the symbol as used. 675 */ 676 if (sdp->sd_flags & FLG_SY_MAPREF) 677 sdp->sd_flags |= FLG_SY_MAPUSED; 678 679 DBG_CALL(Dbg_syms_updated(ofl, sdp, name)); 680 } 681 return (1); 682 } 683 684 685 /* 686 * Print undefined symbols. 687 */ 688 static Boolean undef_title = TRUE; 689 690 static void 691 sym_undef_title(Ofl_desc *ofl) 692 { 693 eprintf(ofl->ofl_lml, ERR_NONE, MSG_INTL(MSG_SYM_FMT_UNDEF), 694 MSG_INTL(MSG_SYM_UNDEF_ITM_11), 695 MSG_INTL(MSG_SYM_UNDEF_ITM_21), 696 MSG_INTL(MSG_SYM_UNDEF_ITM_12), 697 MSG_INTL(MSG_SYM_UNDEF_ITM_22)); 698 699 undef_title = FALSE; 700 } 701 702 /* 703 * Undefined symbols can fall into one of four types: 704 * 705 * o the symbol is really undefined (SHN_UNDEF). 706 * 707 * o versioning has been enabled, however this symbol has not been assigned 708 * to one of the defined versions. 709 * 710 * o the symbol has been defined by an implicitly supplied library, ie. one 711 * which was encounted because it was NEEDED by another library, rather 712 * than from a command line supplied library which would become the only 713 * dependency of the output file being produced. 714 * 715 * o the symbol has been defined by a version of a shared object that is 716 * not permitted for this link-edit. 717 * 718 * In all cases the file who made the first reference to this symbol will have 719 * been recorded via the `sa_rfile' pointer. 720 */ 721 typedef enum { 722 UNDEF, NOVERSION, IMPLICIT, NOTAVAIL, 723 BNDLOCAL 724 } Type; 725 726 static const Msg format[] = { 727 MSG_SYM_UND_UNDEF, /* MSG_INTL(MSG_SYM_UND_UNDEF) */ 728 MSG_SYM_UND_NOVER, /* MSG_INTL(MSG_SYM_UND_NOVER) */ 729 MSG_SYM_UND_IMPL, /* MSG_INTL(MSG_SYM_UND_IMPL) */ 730 MSG_SYM_UND_NOTA, /* MSG_INTL(MSG_SYM_UND_NOTA) */ 731 MSG_SYM_UND_BNDLOCAL /* MSG_INTL(MSG_SYM_UND_BNDLOCAL) */ 732 }; 733 734 static void 735 sym_undef_entry(Ofl_desc *ofl, Sym_desc *sdp, Type type) 736 { 737 const char *name1, *name2, *name3; 738 Ifl_desc *ifl = sdp->sd_file; 739 Sym_aux *sap = sdp->sd_aux; 740 741 if (undef_title) 742 sym_undef_title(ofl); 743 744 switch (type) { 745 case UNDEF: 746 case BNDLOCAL: 747 name1 = sap->sa_rfile; 748 break; 749 case NOVERSION: 750 name1 = ifl->ifl_name; 751 break; 752 case IMPLICIT: 753 name1 = sap->sa_rfile; 754 name2 = ifl->ifl_name; 755 break; 756 case NOTAVAIL: 757 name1 = sap->sa_rfile; 758 name2 = sap->sa_vfile; 759 name3 = ifl->ifl_verndx[sap->sa_dverndx].vi_name; 760 break; 761 default: 762 return; 763 } 764 765 eprintf(ofl->ofl_lml, ERR_NONE, MSG_INTL(format[type]), 766 demangle(sdp->sd_name), name1, name2, name3); 767 } 768 769 /* 770 * At this point all symbol input processing has been completed, therefore 771 * complete the symbol table entries by generating any necessary internal 772 * symbols. 773 */ 774 uintptr_t 775 ld_sym_spec(Ofl_desc *ofl) 776 { 777 Sym_desc *sdp; 778 779 if (ofl->ofl_flags & FLG_OF_RELOBJ) 780 return (1); 781 782 DBG_CALL(Dbg_syms_spec_title(ofl->ofl_lml)); 783 784 if (sym_add_spec(MSG_ORIG(MSG_SYM_ETEXT), MSG_ORIG(MSG_SYM_ETEXT_U), 785 SDAUX_ID_ETEXT, 0, FLG_SY1_GLOB, ofl) == S_ERROR) 786 return (S_ERROR); 787 if (sym_add_spec(MSG_ORIG(MSG_SYM_EDATA), MSG_ORIG(MSG_SYM_EDATA_U), 788 SDAUX_ID_EDATA, 0, FLG_SY1_GLOB, ofl) == S_ERROR) 789 return (S_ERROR); 790 if (sym_add_spec(MSG_ORIG(MSG_SYM_END), MSG_ORIG(MSG_SYM_END_U), 791 SDAUX_ID_END, FLG_SY_DYNSORT, FLG_SY1_GLOB, ofl) == S_ERROR) 792 return (S_ERROR); 793 if (sym_add_spec(MSG_ORIG(MSG_SYM_L_END), MSG_ORIG(MSG_SYM_L_END_U), 794 SDAUX_ID_END, 0, FLG_SY1_LOCL, ofl) == S_ERROR) 795 return (S_ERROR); 796 if (sym_add_spec(MSG_ORIG(MSG_SYM_L_START), MSG_ORIG(MSG_SYM_L_START_U), 797 SDAUX_ID_START, 0, FLG_SY1_LOCL, ofl) == S_ERROR) 798 return (S_ERROR); 799 800 /* 801 * Historically we've always produced a _DYNAMIC symbol, even for 802 * static executables (in which case its value will be 0). 803 */ 804 if (sym_add_spec(MSG_ORIG(MSG_SYM_DYNAMIC), MSG_ORIG(MSG_SYM_DYNAMIC_U), 805 SDAUX_ID_DYN, FLG_SY_DYNSORT, FLG_SY1_GLOB, ofl) == S_ERROR) 806 return (S_ERROR); 807 808 if (OFL_ALLOW_DYNSYM(ofl)) 809 if (sym_add_spec(MSG_ORIG(MSG_SYM_PLKTBL), 810 MSG_ORIG(MSG_SYM_PLKTBL_U), SDAUX_ID_PLT, 811 FLG_SY_DYNSORT, FLG_SY1_GLOB, ofl) == S_ERROR) 812 return (S_ERROR); 813 814 /* 815 * A GOT reference will be accompanied by the associated GOT symbol. 816 * Make sure it gets assigned the appropriate special attributes. 817 */ 818 if (((sdp = ld_sym_find(MSG_ORIG(MSG_SYM_GOFTBL_U), 819 SYM_NOHASH, 0, ofl)) != 0) && (sdp->sd_ref != REF_DYN_SEEN)) { 820 if (sym_add_spec(MSG_ORIG(MSG_SYM_GOFTBL), 821 MSG_ORIG(MSG_SYM_GOFTBL_U), SDAUX_ID_GOT, FLG_SY_DYNSORT, 822 FLG_SY1_GLOB, ofl) == S_ERROR) 823 return (S_ERROR); 824 } 825 826 return (1); 827 } 828 829 /* 830 * This routine checks to see if a symbols visibility needs to be reduced to 831 * either SYMBOLIC or LOCAL. This routine can be called from either 832 * reloc_init() or sym_validate(). 833 */ 834 void 835 ld_sym_adjust_vis(Sym_desc *sdp, Ofl_desc *ofl) 836 { 837 Word symvis, oflags = ofl->ofl_flags, oflags1 = ofl->ofl_flags1; 838 Sym *sym = sdp->sd_sym; 839 840 if ((sdp->sd_ref == REF_REL_NEED) && 841 (sdp->sd_sym->st_shndx != SHN_UNDEF)) { 842 /* 843 * If scoping is enabled, reduce any nonversioned global 844 * symbols (any symbol that has been processed for relocations 845 * will have already had this same reduction test applied). 846 * Indicate that the symbol has been reduced as it may be 847 * necessary to print these symbols later. 848 */ 849 if (((oflags & FLG_OF_AUTOLCL) || 850 (oflags1 & FLG_OF1_AUTOELM)) && 851 ((sdp->sd_flags1 & MSK_SY1_DEFINED) == 0)) { 852 853 sdp->sd_flags |= FLG_SY_REDUCED; 854 sdp->sd_flags1 |= FLG_SY1_LOCL; 855 856 if (ELF_ST_VISIBILITY(sym->st_other) != STV_INTERNAL) 857 sym->st_other = STV_HIDDEN | 858 (sym->st_other & ~MSK_SYM_VISIBILITY); 859 860 if (ofl->ofl_flags1 & 861 (FLG_OF1_REDLSYM | FLG_OF1_AUTOELM)) 862 sdp->sd_flags1 |= FLG_SY1_ELIM; 863 } 864 865 /* 866 * If -Bsymbolic is in effect, and the symbol hasn't explicitly 867 * been defined nodirect (via a mapfile), then bind the global 868 * symbol symbolically and assign the STV_PROTECTED visibility 869 * attribute. 870 */ 871 if ((oflags & FLG_OF_SYMBOLIC) && 872 ((sdp->sd_flags1 & (FLG_SY1_LOCL | FLG_SY1_NDIR)) == 0)) { 873 sdp->sd_flags1 |= FLG_SY1_PROT; 874 if (ELF_ST_VISIBILITY(sym->st_other) == STV_DEFAULT) 875 sym->st_other = STV_PROTECTED | 876 (sym->st_other & ~MSK_SYM_VISIBILITY); 877 } 878 } 879 880 /* 881 * Check to see if the symbol visibility needs to be adjusted due to any 882 * STV_* symbol attributes being set. 883 * 884 * STV_PROTECTED == symbolic binding 885 * STV_INTERNAL == reduce to local 886 * STV_HIDDEN == reduce to local 887 * 888 * Note, UNDEF symbols can be assigned a visibility, thus the refencing 889 * code can be dependent on this visibility. Here, by only ignoring 890 * REF_DYN_SEEN symbol definitions we can be assigning a visibility to 891 * REF_DYN_NEED. If the protected, or local assignment is made to 892 * a REF_DYN_NEED symbol, it will be caught later as an illegal 893 * visibility. 894 */ 895 if (!(oflags & FLG_OF_RELOBJ) && (sdp->sd_ref != REF_DYN_SEEN) && 896 (symvis = ELF_ST_VISIBILITY(sym->st_other))) { 897 if (symvis == STV_PROTECTED) 898 sdp->sd_flags1 |= FLG_SY1_PROT; 899 else if ((symvis == STV_INTERNAL) || (symvis == STV_HIDDEN)) 900 sdp->sd_flags1 |= FLG_SY1_LOCL; 901 } 902 903 /* 904 * Indicate that this symbol has had it's visibility checked so that 905 * we don't need to do this investigation again. 906 */ 907 sdp->sd_flags |= FLG_SY_VISIBLE; 908 } 909 910 /* 911 * Make sure a symbol definition is local to the object being built. 912 */ 913 static int 914 ensure_sym_local(Ofl_desc *ofl, Sym_desc *sdp, const char *str) 915 { 916 if (sdp->sd_sym->st_shndx == SHN_UNDEF) { 917 if (str) { 918 eprintf(ofl->ofl_lml, ERR_FATAL, 919 MSG_INTL(MSG_SYM_UNDEF), str, 920 demangle((char *)sdp->sd_name)); 921 } 922 return (1); 923 } 924 if (sdp->sd_ref != REF_REL_NEED) { 925 if (str) { 926 eprintf(ofl->ofl_lml, ERR_FATAL, 927 MSG_INTL(MSG_SYM_EXTERN), str, 928 demangle((char *)sdp->sd_name), 929 sdp->sd_file->ifl_name); 930 } 931 return (1); 932 } 933 934 sdp->sd_flags |= FLG_SY_UPREQD; 935 if (sdp->sd_isc) { 936 sdp->sd_isc->is_flags |= FLG_IS_SECTREF; 937 sdp->sd_isc->is_file->ifl_flags |= FLG_IF_FILEREF; 938 } 939 return (0); 940 } 941 942 /* 943 * Make sure all the symbol definitions required for initarray, finiarray, or 944 * preinitarray's are local to the object being built. 945 */ 946 static int 947 ensure_array_local(Ofl_desc *ofl, List *list, const char *str) 948 { 949 Listnode *lnp; 950 Sym_desc *sdp; 951 int ret = 0; 952 953 for (LIST_TRAVERSE(list, lnp, sdp)) 954 ret += ensure_sym_local(ofl, sdp, str); 955 956 return (ret); 957 } 958 959 /* 960 * After all symbol table input processing has been finished, and all relocation 961 * counting has been carried out (ie. no more symbols will be read, generated, 962 * or modified), validate and count the relevant entries: 963 * 964 * o check and print any undefined symbols remaining. Note that 965 * if a symbol has been defined by virtue of the inclusion of 966 * an implicit shared library, it is still classed as undefined. 967 * 968 * o count the number of global needed symbols together with the 969 * size of their associated name strings (if scoping has been 970 * indicated these symbols may be reduced to locals). 971 * 972 * o establish the size and alignment requirements for the global 973 * .bss section (the alignment of this section is based on the 974 * first symbol that it will contain). 975 */ 976 uintptr_t 977 ld_sym_validate(Ofl_desc *ofl) 978 { 979 Sym_avlnode *sav; 980 Sym_desc *sdp; 981 Sym *sym; 982 Word oflags = ofl->ofl_flags; 983 Word undef = 0, needed = 0, verdesc = 0; 984 Xword bssalign = 0, tlsalign = 0; 985 Xword bsssize = 0, tlssize = 0; 986 #if defined(__x86) && defined(_ELF64) 987 Xword lbssalign = 0, lbsssize = 0; 988 #endif 989 int ret; 990 int allow_ldynsym; 991 uchar_t type; 992 993 /* 994 * If a symbol is undefined and this link-edit calls for no undefined 995 * symbols to remain (this is the default case when generating an 996 * executable but can be enforced for any object using -z defs), the 997 * symbol is classified as undefined and a fatal error condition will 998 * be indicated. 999 * 1000 * If the symbol is undefined and we're creating a shared object with 1001 * the -Bsymbolic flag, then the symbol is also classified as undefined 1002 * and a warning condition will be indicated. 1003 */ 1004 if ((oflags & (FLG_OF_SHAROBJ | FLG_OF_SYMBOLIC)) == 1005 (FLG_OF_SHAROBJ | FLG_OF_SYMBOLIC)) 1006 undef = FLG_OF_WARN; 1007 if (oflags & FLG_OF_NOUNDEF) 1008 undef = FLG_OF_FATAL; 1009 1010 /* 1011 * If the symbol is referenced from an implicitly included shared object 1012 * (ie. it's not on the NEEDED list) then the symbol is also classified 1013 * as undefined and a fatal error condition will be indicated. 1014 */ 1015 if ((oflags & FLG_OF_NOUNDEF) || !(oflags & FLG_OF_SHAROBJ)) 1016 needed = FLG_OF_FATAL; 1017 1018 /* 1019 * If the output image is being versioned all symbol definitions must be 1020 * associated with a version. Any symbol that isn't is classified as 1021 * undefined and a fatal error condition will be indicated. 1022 */ 1023 if ((oflags & FLG_OF_VERDEF) && (ofl->ofl_vercnt > VER_NDX_GLOBAL)) 1024 verdesc = FLG_OF_FATAL; 1025 1026 allow_ldynsym = OFL_ALLOW_LDYNSYM(ofl); 1027 1028 if (allow_ldynsym) { 1029 /* 1030 * Normally, we disallow symbols with 0 size from appearing 1031 * in a dyn[sym|tls]sort section. However, there are some 1032 * symbols that serve special purposes that we want to exempt 1033 * from this rule. Look them up, and set their 1034 * FLG_SY_DYNSORT flag. 1035 */ 1036 static const char *special[] = { 1037 MSG_ORIG(MSG_SYM_INIT_U), /* _init */ 1038 MSG_ORIG(MSG_SYM_FINI_U), /* _fini */ 1039 MSG_ORIG(MSG_SYM_START), /* _start */ 1040 NULL 1041 }; 1042 int i; 1043 1044 for (i = 0; special[i] != NULL; i++) { 1045 if (((sdp = ld_sym_find(special[i], 1046 SYM_NOHASH, 0, ofl)) != NULL) && 1047 (sdp->sd_sym->st_size == 0)) { 1048 if (ld_sym_copy(sdp) == S_ERROR) 1049 return (S_ERROR); 1050 sdp->sd_flags |= FLG_SY_DYNSORT; 1051 } 1052 } 1053 } 1054 1055 /* 1056 * Collect and validate the globals from the internal symbol table. 1057 */ 1058 for (sav = avl_first(&ofl->ofl_symavl); sav; 1059 sav = AVL_NEXT(&ofl->ofl_symavl, sav)) { 1060 Is_desc * isp; 1061 int undeferr = 0; 1062 1063 sdp = sav->sav_symdesc; 1064 1065 /* 1066 * If undefined symbols are allowed ignore any symbols that are 1067 * not needed. 1068 */ 1069 if (!(oflags & FLG_OF_NOUNDEF) && 1070 (sdp->sd_ref == REF_DYN_SEEN)) 1071 continue; 1072 1073 /* 1074 * If the symbol originates from an external or parent mapfile 1075 * reference and hasn't been matched to a reference from a 1076 * relocatable object, ignore it. 1077 */ 1078 if ((sdp->sd_flags & (FLG_SY_EXTERN | FLG_SY_PARENT)) && 1079 ((sdp->sd_flags & FLG_SY_MAPUSED) == 0)) { 1080 sdp->sd_flags |= FLG_SY_INVALID; 1081 continue; 1082 } 1083 1084 sym = sdp->sd_sym; 1085 type = ELF_ST_TYPE(sym->st_info); 1086 1087 /* 1088 * Sanity check TLS. 1089 */ 1090 if ((type == STT_TLS) && (sym->st_size != 0) && 1091 (sym->st_shndx != SHN_UNDEF) && 1092 (sym->st_shndx != SHN_COMMON)) { 1093 Is_desc * isp = sdp->sd_isc; 1094 Ifl_desc * ifl = sdp->sd_file; 1095 1096 if ((isp == 0) || (isp->is_shdr == 0) || 1097 ((isp->is_shdr->sh_flags & SHF_TLS) == 0)) { 1098 eprintf(ofl->ofl_lml, ERR_FATAL, 1099 MSG_INTL(MSG_SYM_TLS), 1100 demangle(sdp->sd_name), ifl->ifl_name); 1101 ofl->ofl_flags |= FLG_OF_FATAL; 1102 continue; 1103 } 1104 } 1105 1106 if ((sdp->sd_flags & FLG_SY_VISIBLE) == 0) 1107 ld_sym_adjust_vis(sdp, ofl); 1108 1109 if ((sdp->sd_flags & FLG_SY_REDUCED) && 1110 (oflags & FLG_OF_PROCRED)) { 1111 DBG_CALL(Dbg_syms_reduce(ofl, DBG_SYM_REDUCE_GLOBAL, 1112 sdp, 0, 0)); 1113 } 1114 1115 /* 1116 * If building a shared object or executable, and this is a 1117 * non-weak UNDEF symbol with reduced visibility (STV_*), then 1118 * give a fatal error. 1119 */ 1120 if (!(oflags & FLG_OF_RELOBJ) && 1121 ELF_ST_VISIBILITY(sym->st_other) && 1122 (sym->st_shndx == SHN_UNDEF) && 1123 (ELF_ST_BIND(sym->st_info) != STB_WEAK)) { 1124 sym_undef_entry(ofl, sdp, BNDLOCAL); 1125 ofl->ofl_flags |= FLG_OF_FATAL; 1126 continue; 1127 } 1128 1129 /* 1130 * If this symbol is defined in a non-allocatable section, 1131 * reduce it to local symbol. 1132 */ 1133 if (((isp = sdp->sd_isc) != 0) && isp->is_shdr && 1134 ((isp->is_shdr->sh_flags & SHF_ALLOC) == 0)) { 1135 sdp->sd_flags |= FLG_SY_REDUCED; 1136 sdp->sd_flags1 |= FLG_SY1_LOCL; 1137 } 1138 1139 /* 1140 * If this symbol originated as a SHN_SUNW_IGNORE, it will have 1141 * been processed as an SHN_UNDEF. Return the symbol to its 1142 * original index for validation, and propagation to the output 1143 * file. 1144 */ 1145 if (sdp->sd_flags1 & FLG_SY1_IGNORE) 1146 sdp->sd_shndx = SHN_SUNW_IGNORE; 1147 1148 if (undef) { 1149 /* 1150 * If a non-weak reference remains undefined, or if a 1151 * mapfile reference is not bound to the relocatable 1152 * objects that make up the object being built, we have 1153 * a fatal error. 1154 * 1155 * The exceptions are symbols which are defined to be 1156 * found in the parent (FLG_SY_PARENT), which is really 1157 * only meaningful for direct binding, or are defined 1158 * external (FLG_SY_EXTERN) so as to suppress -zdefs 1159 * errors. 1160 * 1161 * Register symbols are always allowed to be UNDEF. 1162 * 1163 * Note that we don't include references created via -u 1164 * in the same shared object binding test. This is for 1165 * backward compatibility, in that a number of archive 1166 * makefile rules used -u to cause archive extraction. 1167 * These same rules have been cut and pasted to apply 1168 * to shared objects, and thus although the -u reference 1169 * is redundant, flagging it as fatal could cause some 1170 * build to fail. Also we have documented the use of 1171 * -u as a mechanism to cause binding to weak version 1172 * definitions, thus giving users an error condition 1173 * would be incorrect. 1174 */ 1175 if (!(sdp->sd_flags & FLG_SY_REGSYM) && 1176 ((sym->st_shndx == SHN_UNDEF) && 1177 ((ELF_ST_BIND(sym->st_info) != STB_WEAK) && 1178 ((sdp->sd_flags & 1179 (FLG_SY_PARENT | FLG_SY_EXTERN)) == 0)) || 1180 (((sdp->sd_flags & 1181 (FLG_SY_MAPREF | FLG_SY_MAPUSED)) == 1182 FLG_SY_MAPREF) && 1183 ((sdp->sd_flags1 & (FLG_SY1_LOCL | 1184 FLG_SY1_PROT)) == 0)))) { 1185 sym_undef_entry(ofl, sdp, UNDEF); 1186 ofl->ofl_flags |= undef; 1187 undeferr = 1; 1188 } 1189 1190 } else { 1191 /* 1192 * For building things like shared objects (or anything 1193 * -znodefs), undefined symbols are allowed. 1194 * 1195 * If a mapfile reference remains undefined the user 1196 * would probably like a warning at least (they've 1197 * usually mis-spelt the reference). Refer to the above 1198 * comments for discussion on -u references, which 1199 * are not tested for in the same manner. 1200 */ 1201 if ((sdp->sd_flags & 1202 (FLG_SY_MAPREF | FLG_SY_MAPUSED)) == 1203 FLG_SY_MAPREF) { 1204 sym_undef_entry(ofl, sdp, UNDEF); 1205 ofl->ofl_flags |= FLG_OF_WARN; 1206 undeferr = 1; 1207 } 1208 } 1209 1210 /* 1211 * If this symbol comes from a dependency mark the dependency 1212 * as required (-z ignore can result in unused dependencies 1213 * being dropped). If we need to record dependency versioning 1214 * information indicate what version of the needed shared object 1215 * this symbol is part of. Flag the symbol as undefined if it 1216 * has not been made available to us. 1217 */ 1218 if ((sdp->sd_ref == REF_DYN_NEED) && 1219 (!(sdp->sd_flags & FLG_SY_REFRSD))) { 1220 sdp->sd_file->ifl_flags |= FLG_IF_DEPREQD; 1221 1222 /* 1223 * Capture that we've bound to a symbol that doesn't 1224 * allow being directly bound to. 1225 */ 1226 if (sdp->sd_flags1 & FLG_SY1_NDIR) 1227 ofl->ofl_flags1 |= FLG_OF1_NDIRECT; 1228 1229 if (sdp->sd_file->ifl_vercnt) { 1230 int vndx; 1231 Ver_index * vip; 1232 1233 vndx = sdp->sd_aux->sa_dverndx; 1234 vip = &sdp->sd_file->ifl_verndx[vndx]; 1235 if (vip->vi_flags & FLG_VER_AVAIL) { 1236 vip->vi_flags |= FLG_VER_REFER; 1237 } else { 1238 sym_undef_entry(ofl, sdp, NOTAVAIL); 1239 ofl->ofl_flags |= FLG_OF_FATAL; 1240 continue; 1241 } 1242 } 1243 } 1244 1245 /* 1246 * Test that we do not bind to symbol supplied from an implicit 1247 * shared object. If a binding is from a weak reference it can 1248 * be ignored. 1249 */ 1250 if (needed && !undeferr && (sdp->sd_flags & FLG_SY_GLOBREF) && 1251 (sdp->sd_ref == REF_DYN_NEED) && 1252 (sdp->sd_flags & FLG_SY_NOTAVAIL)) { 1253 sym_undef_entry(ofl, sdp, IMPLICIT); 1254 ofl->ofl_flags |= needed; 1255 continue; 1256 } 1257 1258 /* 1259 * Test that a symbol isn't going to be reduced to local scope 1260 * which actually wants to bind to a shared object - if so it's 1261 * a fatal error. 1262 */ 1263 if ((sdp->sd_ref == REF_DYN_NEED) && 1264 (sdp->sd_flags1 & (FLG_SY1_LOCL | FLG_SY1_PROT))) { 1265 sym_undef_entry(ofl, sdp, BNDLOCAL); 1266 ofl->ofl_flags |= FLG_OF_FATAL; 1267 continue; 1268 } 1269 1270 /* 1271 * If the output image is to be versioned then all symbol 1272 * definitions must be associated with a version. 1273 */ 1274 if (verdesc && (sdp->sd_ref == REF_REL_NEED) && 1275 (sym->st_shndx != SHN_UNDEF) && 1276 (!(sdp->sd_flags1 & FLG_SY1_LOCL)) && 1277 (sdp->sd_aux->sa_overndx == 0)) { 1278 sym_undef_entry(ofl, sdp, NOVERSION); 1279 ofl->ofl_flags |= verdesc; 1280 continue; 1281 } 1282 1283 /* 1284 * If we don't need the symbol there's no need to process it 1285 * any further. 1286 */ 1287 if (sdp->sd_ref == REF_DYN_SEEN) 1288 continue; 1289 1290 /* 1291 * Calculate the size and alignment requirements for the global 1292 * .bss and .tls sections. If we're building a relocatable 1293 * object only account for scoped COMMON symbols (these will 1294 * be converted to .bss references). 1295 * 1296 * For partially initialized symbol, 1297 * if it is expanded, it goes to sunwdata1. 1298 * if it is local, it goes to .bss. 1299 * if the output is shared object, it goes to .sunwbss. 1300 * 1301 * Also refer to make_mvsections() in sunwmove.c 1302 */ 1303 if ((sym->st_shndx == SHN_COMMON) && 1304 (((oflags & FLG_OF_RELOBJ) == 0) || 1305 ((sdp->sd_flags1 & FLG_SY1_LOCL) && 1306 (oflags & FLG_OF_PROCRED)))) { 1307 int countbss = 0; 1308 1309 if (sdp->sd_psyminfo == 0) { 1310 countbss = 1; 1311 } else if ((sdp->sd_flags & FLG_SY_PAREXPN) != 0) { 1312 countbss = 0; 1313 } else if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) { 1314 countbss = 1; 1315 } else if ((ofl->ofl_flags & FLG_OF_SHAROBJ) != 0) { 1316 countbss = 0; 1317 } else 1318 countbss = 1; 1319 1320 if (countbss) { 1321 Xword * size, * align; 1322 1323 if (type != STT_TLS) { 1324 size = &bsssize; 1325 align = &bssalign; 1326 } else { 1327 size = &tlssize; 1328 align = &tlsalign; 1329 } 1330 *size = (Xword)S_ROUND(*size, sym->st_value) + 1331 sym->st_size; 1332 if (sym->st_value > *align) 1333 *align = sym->st_value; 1334 } 1335 } 1336 1337 #if defined(__x86) && defined(_ELF64) 1338 /* 1339 * Calculate the size and alignment requirement for the global 1340 * .lbss. TLS or partially initialized symbols do not need to be 1341 * considered yet. 1342 */ 1343 if (sym->st_shndx == SHN_X86_64_LCOMMON) { 1344 lbsssize = (Xword)S_ROUND(lbsssize, sym->st_value) + 1345 sym->st_size; 1346 if (sym->st_value > lbssalign) 1347 lbssalign = sym->st_value; 1348 } 1349 #endif 1350 1351 /* 1352 * If a symbol was referenced via the command line 1353 * (ld -u <>, ...), then this counts as a reference against the 1354 * symbol. Mark any section that symbol is defined in. 1355 */ 1356 if (((isp = sdp->sd_isc) != 0) && 1357 (sdp->sd_flags & FLG_SY_CMDREF)) { 1358 isp->is_flags |= FLG_IS_SECTREF; 1359 isp->is_file->ifl_flags |= FLG_IF_FILEREF; 1360 } 1361 1362 /* 1363 * Update the symbol count and the associated name string size. 1364 * If scoping is in effect for this symbol assign it will be 1365 * assigned to the .symtab/.strtab sections. 1366 */ 1367 if ((sdp->sd_flags1 & FLG_SY1_LOCL) && 1368 (oflags & FLG_OF_PROCRED)) { 1369 /* 1370 * If symbol gets eliminated count it. 1371 * 1372 * If symbol gets reduced to local, 1373 * count it's size for the .symtab. 1374 */ 1375 if (sdp->sd_flags1 & FLG_SY1_ELIM) { 1376 ofl->ofl_elimcnt++; 1377 } else { 1378 ofl->ofl_scopecnt++; 1379 if ((((sdp->sd_flags & FLG_SY_REGSYM) == 0) || 1380 sym->st_name) && (st_insert(ofl->ofl_strtab, 1381 sdp->sd_name) == -1)) 1382 return (S_ERROR); 1383 if (allow_ldynsym && sym->st_name && 1384 ldynsym_symtype[type]) { 1385 ofl->ofl_dynscopecnt++; 1386 if (st_insert(ofl->ofl_dynstrtab, 1387 sdp->sd_name) == -1) 1388 return (S_ERROR); 1389 /* Include it in sort section? */ 1390 DYNSORT_COUNT(sdp, sym, type, ++); 1391 } 1392 } 1393 } else { 1394 ofl->ofl_globcnt++; 1395 1396 /* 1397 * Check to see if this global variable should 1398 * go into a sort section. Sort sections require 1399 * a .SUNW_ldynsym section, so, don't check 1400 * unless a .SUNW_ldynsym is allowed. 1401 */ 1402 if (allow_ldynsym) { 1403 DYNSORT_COUNT(sdp, sym, type, ++); 1404 } 1405 1406 /* 1407 * If global direct bindings are in effect, or this 1408 * symbol has bound to a dependency which was specified 1409 * as requiring direct bindings, and it hasn't 1410 * explicitly been defined as a non-direct binding 1411 * symbol, mark it. 1412 */ 1413 if (((ofl->ofl_dtflags_1 & DF_1_DIRECT) || (isp && 1414 (isp->is_file->ifl_flags & FLG_IF_DIRECT))) && 1415 ((sdp->sd_flags1 & FLG_SY1_NDIR) == 0)) 1416 sdp->sd_flags1 |= FLG_SY1_DIR; 1417 1418 /* 1419 * Insert the symbol name. 1420 */ 1421 if (((sdp->sd_flags & FLG_SY_REGSYM) == 0) || 1422 sym->st_name) { 1423 if (st_insert(ofl->ofl_strtab, 1424 sdp->sd_name) == -1) 1425 return (S_ERROR); 1426 1427 if (!(ofl->ofl_flags & FLG_OF_RELOBJ) && 1428 (st_insert(ofl->ofl_dynstrtab, 1429 sdp->sd_name) == -1)) 1430 return (S_ERROR); 1431 } 1432 1433 /* 1434 * If this section offers a global symbol - record that 1435 * fact. 1436 */ 1437 if (isp) { 1438 isp->is_flags |= FLG_IS_SECTREF; 1439 isp->is_file->ifl_flags |= FLG_IF_FILEREF; 1440 } 1441 } 1442 } 1443 1444 /* 1445 * If we've encountered a fatal error during symbol validation then 1446 * return now. 1447 */ 1448 if (ofl->ofl_flags & FLG_OF_FATAL) 1449 return (1); 1450 1451 /* 1452 * Now that symbol resolution is completed, scan any register symbols. 1453 * From now on, we're only interested in those that contribute to the 1454 * output file. 1455 */ 1456 if (ofl->ofl_regsyms) { 1457 int ndx; 1458 1459 for (ndx = 0; ndx < ofl->ofl_regsymsno; ndx++) { 1460 if ((sdp = ofl->ofl_regsyms[ndx]) == 0) 1461 continue; 1462 if (sdp->sd_ref != REF_REL_NEED) { 1463 ofl->ofl_regsyms[ndx] = 0; 1464 continue; 1465 } 1466 1467 ofl->ofl_regsymcnt++; 1468 if (sdp->sd_sym->st_name == 0) 1469 sdp->sd_name = MSG_ORIG(MSG_STR_EMPTY); 1470 1471 if ((sdp->sd_flags1 & FLG_SY1_LOCL) || 1472 (ELF_ST_BIND(sdp->sd_sym->st_info) == STB_LOCAL)) 1473 ofl->ofl_lregsymcnt++; 1474 } 1475 } 1476 1477 /* 1478 * Generate the .bss section now that we know its size and alignment. 1479 */ 1480 if (bsssize || !(oflags & FLG_OF_RELOBJ)) { 1481 if (ld_make_bss(ofl, bsssize, bssalign, MAKE_BSS) == S_ERROR) 1482 return (S_ERROR); 1483 } 1484 if (tlssize) { 1485 if (ld_make_bss(ofl, tlssize, tlsalign, MAKE_TLS) == S_ERROR) 1486 return (S_ERROR); 1487 } 1488 #if defined(__x86) && defined(_ELF64) 1489 if (lbsssize && !(oflags & FLG_OF_RELOBJ)) { 1490 if (ld_make_bss(ofl, lbsssize, lbssalign, MAKE_LBSS) == S_ERROR) 1491 return (S_ERROR); 1492 } 1493 #endif 1494 1495 /* 1496 * Determine what entry point symbol we need, and if found save its 1497 * symbol descriptor so that we can update the ELF header entry with the 1498 * symbols value later (see update_oehdr). Make sure the symbol is 1499 * tagged to ensure its update in case -s is in effect. Use any -e 1500 * option first, or the default entry points `_start' and `main'. 1501 */ 1502 ret = 0; 1503 if (ofl->ofl_entry) { 1504 if ((sdp = 1505 ld_sym_find(ofl->ofl_entry, SYM_NOHASH, 0, ofl)) == NULL) { 1506 eprintf(ofl->ofl_lml, ERR_FATAL, 1507 MSG_INTL(MSG_ARG_NOENTRY), ofl->ofl_entry); 1508 ret++; 1509 } else if (ensure_sym_local(ofl, sdp, 1510 MSG_INTL(MSG_SYM_ENTRY)) != 0) { 1511 ret++; 1512 } else { 1513 ofl->ofl_entry = (void *)sdp; 1514 } 1515 } else if (((sdp = ld_sym_find(MSG_ORIG(MSG_SYM_START), 1516 SYM_NOHASH, 0, ofl)) != NULL) && (ensure_sym_local(ofl, 1517 sdp, 0) == 0)) { 1518 ofl->ofl_entry = (void *)sdp; 1519 1520 } else if (((sdp = ld_sym_find(MSG_ORIG(MSG_SYM_MAIN), 1521 SYM_NOHASH, 0, ofl)) != NULL) && (ensure_sym_local(ofl, 1522 sdp, 0) == 0)) { 1523 ofl->ofl_entry = (void *)sdp; 1524 } 1525 1526 /* 1527 * If ld -zdtrace=<sym> was given, then validate that the symbol is 1528 * defined within the current object being built. 1529 */ 1530 if ((sdp = ofl->ofl_dtracesym) != 0) 1531 ret += ensure_sym_local(ofl, sdp, MSG_ORIG(MSG_STR_DTRACE)); 1532 1533 /* 1534 * If any initarray, finiarray or preinitarray functions have been 1535 * requested, make sure they are defined within the current object 1536 * being built. 1537 */ 1538 if (ofl->ofl_initarray.head) { 1539 ret += ensure_array_local(ofl, &ofl->ofl_initarray, 1540 MSG_ORIG(MSG_SYM_INITARRAY)); 1541 } 1542 if (ofl->ofl_finiarray.head) { 1543 ret += ensure_array_local(ofl, &ofl->ofl_finiarray, 1544 MSG_ORIG(MSG_SYM_FINIARRAY)); 1545 } 1546 if (ofl->ofl_preiarray.head) { 1547 ret += ensure_array_local(ofl, &ofl->ofl_preiarray, 1548 MSG_ORIG(MSG_SYM_PREINITARRAY)); 1549 } 1550 1551 if (ret) 1552 return (S_ERROR); 1553 1554 /* 1555 * If we're required to record any needed dependencies versioning 1556 * information calculate it now that all symbols have been validated. 1557 */ 1558 if ((oflags & (FLG_OF_VERNEED | FLG_OF_NOVERSEC)) == FLG_OF_VERNEED) 1559 return (ld_vers_check_need(ofl)); 1560 else 1561 return (1); 1562 } 1563 1564 /* 1565 * qsort(3c) comparison function. As an optimization for associating weak 1566 * symbols to their strong counterparts sort global symbols according to their 1567 * address and binding. 1568 */ 1569 static int 1570 compare(const void * sdpp1, const void * sdpp2) 1571 { 1572 Sym_desc * sdp1 = *((Sym_desc **)sdpp1); 1573 Sym_desc * sdp2 = *((Sym_desc **)sdpp2); 1574 Sym * sym1, * sym2; 1575 uchar_t bind1, bind2; 1576 1577 /* 1578 * Symbol descriptors may be zero, move these to the front of the 1579 * sorted array. 1580 */ 1581 if (sdp1 == 0) 1582 return (-1); 1583 if (sdp2 == 0) 1584 return (1); 1585 1586 sym1 = sdp1->sd_sym; 1587 sym2 = sdp2->sd_sym; 1588 1589 /* 1590 * Compare the symbols value (address). 1591 */ 1592 if (sym1->st_value > sym2->st_value) 1593 return (1); 1594 if (sym1->st_value < sym2->st_value) 1595 return (-1); 1596 1597 bind1 = ELF_ST_BIND(sym1->st_info); 1598 bind2 = ELF_ST_BIND(sym2->st_info); 1599 1600 /* 1601 * If two symbols have the same address place the weak symbol before 1602 * any strong counterpart. 1603 */ 1604 if (bind1 > bind2) 1605 return (-1); 1606 if (bind1 < bind2) 1607 return (1); 1608 1609 return (0); 1610 } 1611 1612 1613 /* 1614 * Issue a MSG_SYM_BADADDR error from ld_sym_process(). This error 1615 * is issued when a symbol address/size is not contained by the 1616 * target section. 1617 * 1618 * Such objects are at least partially corrupt, and the user would 1619 * be well advised to be skeptical of them, and to ask their compiler 1620 * supplier to fix the problem. However, a distinction needs to be 1621 * made between symbols that reference readonly text, and those that 1622 * access writable data. Other than throwing off profiling results, 1623 * the readonly section case is less serious. We have encountered 1624 * such objects in the field. In order to allow existing objects 1625 * to continue working, we issue a warning rather than a fatal error 1626 * if the symbol is against readonly text. Other cases are fatal. 1627 */ 1628 static void 1629 issue_badaddr_msg(Ifl_desc *ifl, Ofl_desc *ofl, Sym_desc *sdp, 1630 Sym *sym, Word shndx) 1631 { 1632 Lword flag; 1633 Error err; 1634 const char *msg; 1635 1636 if ((sdp->sd_isc->is_shdr->sh_flags & (SHF_WRITE | SHF_ALLOC)) == 1637 SHF_ALLOC) { 1638 msg = MSG_INTL(MSG_SYM_BADADDR_ROTXT); 1639 flag = FLG_OF_WARN; 1640 err = ERR_WARNING; 1641 } else { 1642 msg = MSG_INTL(MSG_SYM_BADADDR); 1643 flag = FLG_OF_FATAL; 1644 err = ERR_FATAL; 1645 } 1646 1647 eprintf(ofl->ofl_lml, err, msg, demangle(sdp->sd_name), 1648 ifl->ifl_name, shndx, sdp->sd_isc->is_name, 1649 EC_XWORD(sdp->sd_isc->is_shdr->sh_size), 1650 EC_XWORD(sym->st_value), EC_XWORD(sym->st_size)); 1651 ofl->ofl_flags |= flag; 1652 } 1653 1654 1655 /* 1656 * Process the symbol table for the specified input file. At this point all 1657 * input sections from this input file have been assigned an input section 1658 * descriptor which is saved in the `ifl_isdesc' array. 1659 * 1660 * o local symbols are saved (as is) if the input file is a 1661 * relocatable object 1662 * 1663 * o global symbols are added to the linkers internal symbol 1664 * table if they are not already present, otherwise a symbol 1665 * resolution function is called upon to resolve the conflict. 1666 */ 1667 uintptr_t 1668 ld_sym_process(Is_desc *isc, Ifl_desc *ifl, Ofl_desc *ofl) 1669 { 1670 /* 1671 * This macro tests the given symbol to see if it is out of 1672 * range relative to the section it references. 1673 * 1674 * entry: 1675 * - ifl is a relative object (ET_REL) 1676 * _sdp - Symbol descriptor 1677 * _sym - Symbol 1678 * _type - Symbol type 1679 * 1680 * The following are tested: 1681 * - Symbol length is non-zero 1682 * - Symbol type is a type that references code or data 1683 * - Referenced section is not 0 (indicates an UNDEF symbol) 1684 * and is not in the range of special values above SHN_LORESERVE 1685 * (excluding SHN_XINDEX, which is OK). 1686 * - We have a valid section header for the target section 1687 * 1688 * If the above are all true, and the symbol position is not 1689 * contained by the target section, this macro evaluates to 1690 * True (1). Otherwise, False(0). 1691 */ 1692 #define SYM_LOC_BADADDR(_sdp, _sym, _type) \ 1693 (_sym->st_size && dynsymsort_symtype[_type] && \ 1694 (_sym->st_shndx != SHN_UNDEF) && \ 1695 ((_sym->st_shndx < SHN_LORESERVE) || \ 1696 (_sym->st_shndx == SHN_XINDEX)) && \ 1697 _sdp->sd_isc && _sdp->sd_isc->is_shdr && \ 1698 ((_sym->st_value + _sym->st_size) > _sdp->sd_isc->is_shdr->sh_size)) 1699 1700 Sym *sym = (Sym *)isc->is_indata->d_buf; 1701 Word *symshndx = 0; 1702 Shdr *shdr = isc->is_shdr; 1703 Sym_desc *sdp; 1704 size_t strsize; 1705 char *strs; 1706 uchar_t type, bind; 1707 Word ndx, hash, local, total; 1708 Half etype = ifl->ifl_ehdr->e_type; 1709 int etype_rel; 1710 const char *symsecname, *strsecname; 1711 avl_index_t where; 1712 1713 /* 1714 * Its possible that a file may contain more that one symbol table, 1715 * ie. .dynsym and .symtab in a shared library. Only process the first 1716 * table (here, we assume .dynsym comes before .symtab). 1717 */ 1718 if (ifl->ifl_symscnt) 1719 return (1); 1720 1721 if (isc->is_symshndx) 1722 symshndx = isc->is_symshndx->is_indata->d_buf; 1723 1724 DBG_CALL(Dbg_syms_process(ofl->ofl_lml, ifl)); 1725 1726 if (isc->is_name) 1727 symsecname = isc->is_name; 1728 else 1729 symsecname = MSG_ORIG(MSG_STR_EMPTY); 1730 1731 /* 1732 * From the symbol tables section header information determine which 1733 * strtab table is needed to locate the actual symbol names. 1734 */ 1735 if (ifl->ifl_flags & FLG_IF_HSTRTAB) { 1736 ndx = shdr->sh_link; 1737 if ((ndx == 0) || (ndx >= ifl->ifl_shnum)) { 1738 eprintf(ofl->ofl_lml, ERR_FATAL, 1739 MSG_INTL(MSG_FIL_INVSHLINK), 1740 ifl->ifl_name, symsecname, EC_XWORD(ndx)); 1741 return (S_ERROR); 1742 } 1743 strsize = ifl->ifl_isdesc[ndx]->is_shdr->sh_size; 1744 strs = ifl->ifl_isdesc[ndx]->is_indata->d_buf; 1745 if (ifl->ifl_isdesc[ndx]->is_name) 1746 strsecname = ifl->ifl_isdesc[ndx]->is_name; 1747 else 1748 strsecname = MSG_ORIG(MSG_STR_EMPTY); 1749 } else { 1750 /* 1751 * There is no string table section in this input file 1752 * although there are symbols in this symbol table section. 1753 * This means that these symbols do not have names. 1754 * Currently, only scratch register symbols are allowed 1755 * not to have names. 1756 */ 1757 strsize = 0; 1758 strs = (char *)MSG_ORIG(MSG_STR_EMPTY); 1759 strsecname = MSG_ORIG(MSG_STR_EMPTY); 1760 } 1761 1762 /* 1763 * Determine the number of local symbols together with the total 1764 * number we have to process. 1765 */ 1766 total = (Word)(shdr->sh_size / shdr->sh_entsize); 1767 local = shdr->sh_info; 1768 1769 /* 1770 * Allocate a symbol table index array and a local symbol array 1771 * (global symbols are processed and added to the ofl->ofl_symbkt[] 1772 * array). If we are dealing with a relocatable object, allocate the 1773 * local symbol descriptors. If this isn't a relocatable object we 1774 * still have to process any shared object locals to determine if any 1775 * register symbols exist. Although these aren't added to the output 1776 * image, they are used as part of symbol resolution. 1777 */ 1778 if ((ifl->ifl_oldndx = libld_malloc((size_t)(total * 1779 sizeof (Sym_desc *)))) == 0) 1780 return (S_ERROR); 1781 etype_rel = (etype == ET_REL); 1782 if (etype_rel && local) { 1783 if ((ifl->ifl_locs = 1784 libld_calloc(sizeof (Sym_desc), local)) == 0) 1785 return (S_ERROR); 1786 /* LINTED */ 1787 ifl->ifl_locscnt = (Word)local; 1788 } 1789 ifl->ifl_symscnt = total; 1790 1791 /* 1792 * If there are local symbols to save add them to the symbol table 1793 * index array. 1794 */ 1795 if (local) { 1796 int allow_ldynsym = OFL_ALLOW_LDYNSYM(ofl); 1797 for (sym++, ndx = 1; ndx < local; sym++, ndx++) { 1798 Word shndx, sdflags = FLG_SY_CLEAN; 1799 const char *name; 1800 Sym_desc *rsdp; 1801 1802 /* 1803 * Determine the associated section index. 1804 */ 1805 if (symshndx && (sym->st_shndx == SHN_XINDEX)) 1806 shndx = symshndx[ndx]; 1807 else if ((shndx = sym->st_shndx) >= SHN_LORESERVE) 1808 sdflags |= FLG_SY_SPECSEC; 1809 1810 /* 1811 * Check if st_name has a valid value or not. 1812 */ 1813 if ((name = string(ofl, ifl, sym, strs, strsize, ndx, 1814 shndx, symsecname, strsecname, &sdflags)) == 0) { 1815 ofl->ofl_flags |= FLG_OF_FATAL; 1816 continue; 1817 } 1818 1819 /* 1820 * If this local symbol table originates from a shared 1821 * object, then we're only interested in recording 1822 * register symbols. As local symbol descriptors aren't 1823 * allocated for shared objects, one will be allocated 1824 * to associated with the register symbol. This symbol 1825 * won't become part of the output image, but we must 1826 * process it to test for register conflicts. 1827 */ 1828 rsdp = sdp = 0; 1829 if (sdflags & FLG_SY_REGSYM) { 1830 if ((rsdp = ld_reg_find(sym, ofl)) != 0) { 1831 /* 1832 * The fact that another register def- 1833 * inition has been found is fatal. 1834 * Call the verification routine to get 1835 * the error message and move on. 1836 */ 1837 (void) ld_reg_check(rsdp, sym, name, 1838 ifl, ofl); 1839 continue; 1840 } 1841 1842 if (etype == ET_DYN) { 1843 if ((sdp = libld_calloc( 1844 sizeof (Sym_desc), 1)) == 0) 1845 return (S_ERROR); 1846 sdp->sd_ref = REF_DYN_SEEN; 1847 } 1848 } else if (etype == ET_DYN) 1849 continue; 1850 1851 /* 1852 * Fill in the remaining symbol descriptor information. 1853 */ 1854 if (sdp == 0) { 1855 sdp = &(ifl->ifl_locs[ndx]); 1856 sdp->sd_ref = REF_REL_NEED; 1857 } 1858 if (rsdp == 0) { 1859 sdp->sd_name = name; 1860 sdp->sd_sym = sym; 1861 sdp->sd_shndx = shndx; 1862 sdp->sd_flags = sdflags; 1863 sdp->sd_file = ifl; 1864 ifl->ifl_oldndx[ndx] = sdp; 1865 } 1866 1867 DBG_CALL(Dbg_syms_entry(ofl->ofl_lml, ndx, sdp)); 1868 1869 /* 1870 * Reclassify any SHN_SUNW_IGNORE symbols to SHN_UNDEF 1871 * so as to simplify future processing. 1872 */ 1873 if (sym->st_shndx == SHN_SUNW_IGNORE) { 1874 sdp->sd_shndx = shndx = SHN_UNDEF; 1875 sdp->sd_flags1 |= 1876 (FLG_SY1_IGNORE | FLG_SY1_ELIM); 1877 } 1878 1879 /* 1880 * Process any register symbols. 1881 */ 1882 if (sdp->sd_flags & FLG_SY_REGSYM) { 1883 /* 1884 * Add a diagnostic to indicate we've caught a 1885 * register symbol, as this can be useful if a 1886 * register conflict is later discovered. 1887 */ 1888 DBG_CALL(Dbg_syms_entered(ofl, sym, sdp)); 1889 1890 /* 1891 * If this register symbol hasn't already been 1892 * recorded, enter it now. 1893 */ 1894 if ((rsdp == 0) && 1895 (ld_reg_enter(sdp, ofl) == 0)) 1896 return (S_ERROR); 1897 } 1898 1899 /* 1900 * Assign an input section. 1901 */ 1902 if ((sym->st_shndx != SHN_UNDEF) && 1903 ((sdp->sd_flags & FLG_SY_SPECSEC) == 0)) 1904 sdp->sd_isc = ifl->ifl_isdesc[shndx]; 1905 1906 /* 1907 * If this symbol falls within the range of a section 1908 * being discarded, then discard the symbol itself. 1909 * There is no reason to keep this local symbol. 1910 */ 1911 if (sdp->sd_isc && 1912 (sdp->sd_isc->is_flags & FLG_IS_DISCARD)) { 1913 sdp->sd_flags |= FLG_SY_ISDISC; 1914 DBG_CALL(Dbg_syms_discarded(ofl->ofl_lml, 1915 sdp, sdp->sd_isc)); 1916 continue; 1917 } 1918 1919 /* 1920 * Skip any section symbols as new versions of these 1921 * will be created. 1922 */ 1923 if ((type = ELF_ST_TYPE(sym->st_info)) == STT_SECTION) { 1924 if (sym->st_shndx == SHN_UNDEF) { 1925 eprintf(ofl->ofl_lml, ERR_WARNING, 1926 MSG_INTL(MSG_SYM_INVSHNDX), 1927 demangle(sdp->sd_name), 1928 ifl->ifl_name, 1929 conv_sym_shndx(sym->st_shndx)); 1930 } 1931 continue; 1932 } 1933 1934 /* 1935 * For a relocatable object, if this symbol is defined 1936 * and has non-zero length and references an address 1937 * within an associated section, then check its extents 1938 * to make sure the section boundaries encompass it. 1939 * If they don't, the ELF file is corrupt. 1940 */ 1941 if (etype_rel && SYM_LOC_BADADDR(sdp, sym, type)) { 1942 issue_badaddr_msg(ifl, ofl, sdp, sym, shndx); 1943 continue; 1944 } 1945 1946 /* 1947 * Sanity check for TLS 1948 */ 1949 if ((sym->st_size != 0) && ((type == STT_TLS) && 1950 (sym->st_shndx != SHN_COMMON))) { 1951 Is_desc *isp = sdp->sd_isc; 1952 1953 if ((isp == 0) || (isp->is_shdr == 0) || 1954 ((isp->is_shdr->sh_flags & SHF_TLS) == 0)) { 1955 eprintf(ofl->ofl_lml, ERR_FATAL, 1956 MSG_INTL(MSG_SYM_TLS), 1957 demangle(sdp->sd_name), 1958 ifl->ifl_name); 1959 ofl->ofl_flags |= FLG_OF_FATAL; 1960 continue; 1961 } 1962 } 1963 1964 /* 1965 * Carry our some basic sanity checks (these are just 1966 * some of the erroneous symbol entries we've come 1967 * across, there's probably a lot more). The symbol 1968 * will not be carried forward to the output file, which 1969 * won't be a problem unless a relocation is required 1970 * against it. 1971 */ 1972 if (((sdp->sd_flags & FLG_SY_SPECSEC) && 1973 ((sym->st_shndx == SHN_COMMON)) || 1974 ((type == STT_FILE) && 1975 (sym->st_shndx != SHN_ABS))) || 1976 (sdp->sd_isc && (sdp->sd_isc->is_osdesc == 0))) { 1977 eprintf(ofl->ofl_lml, ERR_WARNING, 1978 MSG_INTL(MSG_SYM_INVSHNDX), 1979 demangle(sdp->sd_name), ifl->ifl_name, 1980 conv_sym_shndx(sym->st_shndx)); 1981 sdp->sd_isc = NULL; 1982 sdp->sd_flags |= FLG_SY_INVALID; 1983 continue; 1984 } 1985 1986 /* 1987 * As these local symbols will become part of the output 1988 * image, record their number and name string size. 1989 * Globals are counted after all input file processing 1990 * (and hence symbol resolution) is complete during 1991 * sym_validate(). 1992 */ 1993 if (!(ofl->ofl_flags1 & FLG_OF1_REDLSYM)) { 1994 ofl->ofl_locscnt++; 1995 1996 if ((((sdp->sd_flags & FLG_SY_REGSYM) == 0) || 1997 sym->st_name) && (st_insert(ofl->ofl_strtab, 1998 sdp->sd_name) == -1)) 1999 return (S_ERROR); 2000 2001 if (allow_ldynsym && sym->st_name && 2002 ldynsym_symtype[type]) { 2003 ofl->ofl_dynlocscnt++; 2004 if (st_insert(ofl->ofl_dynstrtab, 2005 sdp->sd_name) == -1) 2006 return (S_ERROR); 2007 /* Include it in sort section? */ 2008 DYNSORT_COUNT(sdp, sym, type, ++); 2009 } 2010 } 2011 } 2012 } 2013 2014 /* 2015 * Now scan the global symbols entering them in the internal symbol 2016 * table or resolving them as necessary. 2017 */ 2018 sym = (Sym *)isc->is_indata->d_buf; 2019 sym += local; 2020 /* LINTED */ 2021 for (ndx = (int)local; ndx < total; sym++, ndx++) { 2022 const char *name; 2023 Word shndx, sdflags = 0; 2024 2025 /* 2026 * Determine the associated section index. 2027 */ 2028 if (symshndx && (sym->st_shndx == SHN_XINDEX)) { 2029 shndx = symshndx[ndx]; 2030 } else { 2031 shndx = sym->st_shndx; 2032 if (sym->st_shndx >= SHN_LORESERVE) 2033 sdflags |= FLG_SY_SPECSEC; 2034 } 2035 2036 /* 2037 * Check if st_name has a valid value or not. 2038 */ 2039 if ((name = string(ofl, ifl, sym, strs, strsize, ndx, shndx, 2040 symsecname, strsecname, &sdflags)) == 0) { 2041 ofl->ofl_flags |= FLG_OF_FATAL; 2042 continue; 2043 } 2044 2045 /* 2046 * To accomodate objects built with the GNU ld, we quietly 2047 * ignore symbols with a version that is outside the range 2048 * of the valid versions supplied by the file. See the 2049 * comment that accompanies the VERSYM_INVALID macro in libld.h 2050 * for additional details. 2051 */ 2052 if (VERNDX_INVALID(shndx, ifl->ifl_vercnt, 2053 ifl->ifl_versym, ndx)) 2054 continue; 2055 2056 /* 2057 * The linker itself will generate symbols for _end, _etext, 2058 * _edata, _DYNAMIC and _PROCEDURE_LINKAGE_TABLE_, so don't 2059 * bother entering these symbols from shared objects. This 2060 * results in some wasted resolution processing, which is hard 2061 * to feel, but if nothing else, pollutes diagnostic relocation 2062 * output. 2063 */ 2064 if (name[0] && (etype == ET_DYN) && (sym->st_size == 0) && 2065 (ELF_ST_TYPE(sym->st_info) == STT_OBJECT) && 2066 (name[0] == '_') && ((name[1] == 'e') || 2067 (name[1] == 'D') || (name[1] == 'P')) && 2068 ((strcmp(name, MSG_ORIG(MSG_SYM_ETEXT_U)) == 0) || 2069 (strcmp(name, MSG_ORIG(MSG_SYM_EDATA_U)) == 0) || 2070 (strcmp(name, MSG_ORIG(MSG_SYM_END_U)) == 0) || 2071 (strcmp(name, MSG_ORIG(MSG_SYM_DYNAMIC_U)) == 0) || 2072 (strcmp(name, MSG_ORIG(MSG_SYM_PLKTBL_U)) == 0))) { 2073 ifl->ifl_oldndx[ndx] = 0; 2074 continue; 2075 } 2076 2077 /* 2078 * Determine and validate the symbols binding. 2079 */ 2080 bind = ELF_ST_BIND(sym->st_info); 2081 if ((bind != STB_GLOBAL) && (bind != STB_WEAK)) { 2082 eprintf(ofl->ofl_lml, ERR_WARNING, 2083 MSG_INTL(MSG_SYM_NONGLOB), demangle(name), 2084 ifl->ifl_name, conv_sym_info_bind(bind, 0)); 2085 continue; 2086 } 2087 2088 /* 2089 * If this symbol falls within the range of a section being 2090 * discarded, then discard the symbol itself. 2091 */ 2092 if (((sdflags & FLG_SY_SPECSEC) == 0) && 2093 (sym->st_shndx != SHN_UNDEF)) { 2094 Is_desc *isp; 2095 2096 if (shndx >= ifl->ifl_shnum) { 2097 /* 2098 * Carry our some basic sanity checks 2099 * The symbol will not be carried forward to 2100 * the output file, which won't be a problem 2101 * unless a relocation is required against it. 2102 */ 2103 eprintf(ofl->ofl_lml, ERR_WARNING, 2104 MSG_INTL(MSG_SYM_INVSHNDX), demangle(name), 2105 ifl->ifl_name, 2106 conv_sym_shndx(sym->st_shndx)); 2107 continue; 2108 } 2109 2110 isp = ifl->ifl_isdesc[shndx]; 2111 if (isp && (isp->is_flags & FLG_IS_DISCARD)) { 2112 if ((sdp = 2113 libld_calloc(sizeof (Sym_desc), 1)) == 0) 2114 return (S_ERROR); 2115 2116 /* 2117 * Create a dummy symbol entry so that if we 2118 * find any references to this discarded symbol 2119 * we can compensate. 2120 */ 2121 sdp->sd_name = name; 2122 sdp->sd_sym = sym; 2123 sdp->sd_file = ifl; 2124 sdp->sd_isc = isp; 2125 sdp->sd_flags = FLG_SY_ISDISC; 2126 ifl->ifl_oldndx[ndx] = sdp; 2127 2128 DBG_CALL(Dbg_syms_discarded(ofl->ofl_lml, sdp, 2129 sdp->sd_isc)); 2130 continue; 2131 } 2132 } 2133 2134 /* 2135 * If the symbol does not already exist in the internal symbol 2136 * table add it, otherwise resolve the conflict. If the symbol 2137 * from this file is kept, retain its symbol table index for 2138 * possible use in associating a global alias. 2139 */ 2140 /* LINTED */ 2141 hash = (Word)elf_hash((const char *)name); 2142 if ((sdp = ld_sym_find(name, hash, &where, ofl)) == NULL) { 2143 DBG_CALL(Dbg_syms_global(ofl->ofl_lml, ndx, name)); 2144 if ((sdp = ld_sym_enter(name, sym, hash, ifl, ofl, ndx, 2145 shndx, sdflags, 0, &where)) == (Sym_desc *)S_ERROR) 2146 return (S_ERROR); 2147 2148 } else if (ld_sym_resolve(sdp, sym, ifl, ofl, ndx, shndx, 2149 sdflags) == S_ERROR) 2150 return (S_ERROR); 2151 2152 /* 2153 * After we've compared a defined symbol in one shared 2154 * object, flag the symbol so we don't compare it again. 2155 */ 2156 if ((etype == ET_DYN) && (sym->st_shndx != SHN_UNDEF) && 2157 ((sdp->sd_flags & FLG_SY_SOFOUND) == 0)) 2158 sdp->sd_flags |= FLG_SY_SOFOUND; 2159 2160 /* 2161 * If the symbol is accepted from this file retain the symbol 2162 * index for possible use in aliasing. 2163 */ 2164 if (sdp->sd_file == ifl) 2165 sdp->sd_symndx = ndx; 2166 2167 ifl->ifl_oldndx[ndx] = sdp; 2168 2169 /* 2170 * If we've accepted a register symbol, continue to validate 2171 * it. 2172 */ 2173 if (sdp->sd_flags & FLG_SY_REGSYM) { 2174 Sym_desc *rsdp; 2175 2176 if ((rsdp = ld_reg_find(sdp->sd_sym, ofl)) == 0) { 2177 if (ld_reg_enter(sdp, ofl) == 0) 2178 return (S_ERROR); 2179 } else if (rsdp != sdp) { 2180 (void) ld_reg_check(rsdp, sdp->sd_sym, 2181 sdp->sd_name, ifl, ofl); 2182 } 2183 } 2184 2185 /* 2186 * For a relocatable object, if this symbol is defined 2187 * and has non-zero length and references an address 2188 * within an associated section, then check its extents 2189 * to make sure the section boundaries encompass it. 2190 * If they don't, the ELF file is corrupt. Note that this 2191 * global symbol may have come from another file to satisfy 2192 * an UNDEF symbol of the same name from this one. In that 2193 * case, we don't check it, because it was already checked 2194 * as part of its own file. 2195 */ 2196 if (etype_rel && (sdp->sd_file == ifl)) { 2197 Sym *tsym = sdp->sd_sym; 2198 2199 if (SYM_LOC_BADADDR(sdp, tsym, 2200 ELF_ST_TYPE(tsym->st_info))) { 2201 issue_badaddr_msg(ifl, ofl, sdp, 2202 tsym, tsym->st_shndx); 2203 continue; 2204 } 2205 } 2206 } 2207 2208 /* 2209 * If this is a shared object scan the globals one more time and 2210 * associate any weak/global associations. This association is needed 2211 * should the weak definition satisfy a reference in the dynamic 2212 * executable: 2213 * 2214 * o if the symbol is a data item it will be copied to the 2215 * executables address space, thus we must also reassociate the 2216 * alias symbol with its new location in the executable. 2217 * 2218 * o if the symbol is a function then we may need to promote the 2219 * symbols binding from undefined weak to undefined, otherwise the 2220 * run-time linker will not generate the correct relocation error 2221 * should the symbol not be found. 2222 * 2223 * The true association between a weak/strong symbol pair is that both 2224 * symbol entries are identical, thus first we created a sorted symbol 2225 * list keyed off of the symbols value (if the value is the same chances 2226 * are the rest of the symbols data is). This list is then scanned for 2227 * weak symbols, and if one is found then any strong association will 2228 * exist in the following entries. Thus we just have to scan one 2229 * (typical single alias) or more (in the uncommon instance of multiple 2230 * weak to strong associations) entries to determine if a match exists. 2231 */ 2232 if ((OFL_ALLOW_LDYNSYM(ofl) || (etype == ET_DYN)) && 2233 (total > local)) { 2234 Sym_desc ** sort; 2235 size_t size = (total - local) * sizeof (Sym_desc *); 2236 2237 if ((sort = libld_malloc(size)) == 0) 2238 return (S_ERROR); 2239 (void) memcpy((void *)sort, &ifl->ifl_oldndx[local], size); 2240 2241 qsort(sort, (total - local), sizeof (Sym_desc *), compare); 2242 2243 for (ndx = 0; ndx < (total - local); ndx++) { 2244 Sym_desc * wsdp = sort[ndx]; 2245 Sym * wsym; 2246 int sndx; 2247 2248 if (wsdp == 0) 2249 continue; 2250 2251 wsym = wsdp->sd_sym; 2252 2253 if ((ELF_ST_BIND(wsym->st_info) != STB_WEAK) || 2254 (wsdp->sd_sym->st_shndx == SHN_UNDEF) || 2255 (wsdp->sd_flags & FLG_SY_SPECSEC)) 2256 continue; 2257 2258 /* 2259 * We have a weak symbol, if it has a strong alias it 2260 * will have been sorted to one of the following sort 2261 * table entries. Note that we could have multiple weak 2262 * symbols aliased to one strong (if this occurs then 2263 * the strong symbol only maintains one alias back to 2264 * the last weak). 2265 */ 2266 for (sndx = ndx + 1; sndx < (total - local); sndx++) { 2267 Sym_desc * ssdp = sort[sndx]; 2268 Sym * ssym; 2269 2270 if (ssdp == 0) 2271 break; 2272 2273 ssym = ssdp->sd_sym; 2274 2275 if (wsym->st_value != ssym->st_value) 2276 break; 2277 2278 if ((ssdp->sd_file == ifl) && 2279 (wsdp->sd_file == ifl) && 2280 (wsym->st_size == ssym->st_size) && 2281 (ssdp->sd_sym->st_shndx != SHN_UNDEF) && 2282 (ELF_ST_BIND(ssym->st_info) != STB_WEAK) && 2283 ((ssdp->sd_flags & FLG_SY_SPECSEC) == 0)) { 2284 int w_dynbits, s_dynbits; 2285 2286 /* 2287 * If a sharable object, set link 2288 * fields so they reference each other 2289 */ 2290 if (etype == ET_DYN) { 2291 ssdp->sd_aux->sa_linkndx = 2292 (Word)wsdp->sd_symndx; 2293 wsdp->sd_aux->sa_linkndx = 2294 (Word)ssdp->sd_symndx; 2295 } 2296 /* 2297 * Determine which of these two symbols 2298 * go into the sort section. If the 2299 * mapfile has made explicit settings 2300 * of the FLG_SY_*DYNSORT flags for both 2301 * symbols, then we do what they say. 2302 * If one has the DYNSORT flags set, 2303 * we set the NODYNSORT bit in the 2304 * other. And if neither has an 2305 * explicit setting, then we favor the 2306 * weak symbol because they usually 2307 * lack the leading underscore. 2308 */ 2309 w_dynbits = wsdp->sd_flags & 2310 (FLG_SY_DYNSORT | FLG_SY_NODYNSORT); 2311 s_dynbits = ssdp->sd_flags & 2312 (FLG_SY_DYNSORT | FLG_SY_NODYNSORT); 2313 if (!(w_dynbits && s_dynbits)) { 2314 if (s_dynbits) { 2315 if (s_dynbits == 2316 FLG_SY_DYNSORT) 2317 wsdp->sd_flags |= 2318 FLG_SY_NODYNSORT; 2319 } else if (w_dynbits != 2320 FLG_SY_NODYNSORT) { 2321 ssdp->sd_flags |= 2322 FLG_SY_NODYNSORT; 2323 } 2324 } 2325 break; 2326 } 2327 } 2328 } 2329 } 2330 return (1); 2331 2332 #undef SYM_LOC_BADADDR 2333 } 2334 2335 /* 2336 * Add an undefined symbol to the symbol table. The reference originates from 2337 * the location identifed by the message id (mid). These references can 2338 * originate from command line options such as -e, -u, -initarray, etc. 2339 * (identified with MSG_INTL(MSG_STR_COMMAND)), or from internally generated 2340 * TLS relocation references (identified with MSG_INTL(MSG_STR_TLSREL)). 2341 */ 2342 Sym_desc * 2343 ld_sym_add_u(const char *name, Ofl_desc *ofl, Msg mid) 2344 { 2345 Sym *sym; 2346 Ifl_desc *ifl = 0, *_ifl; 2347 Sym_desc *sdp; 2348 Word hash; 2349 Listnode *lnp; 2350 avl_index_t where; 2351 const char *reference = MSG_INTL(mid); 2352 2353 /* 2354 * If the symbol reference already exists indicate that a reference 2355 * also came from the command line. 2356 */ 2357 /* LINTED */ 2358 hash = (Word)elf_hash(name); 2359 if (sdp = ld_sym_find(name, hash, &where, ofl)) { 2360 if (sdp->sd_ref == REF_DYN_SEEN) 2361 sdp->sd_ref = REF_DYN_NEED; 2362 return (sdp); 2363 } 2364 2365 /* 2366 * Determine whether a pseudo input file descriptor exists to represent 2367 * the command line, as any global symbol needs an input file descriptor 2368 * during any symbol resolution (refer to map_ifl() which provides a 2369 * similar method for adding symbols from mapfiles). 2370 */ 2371 for (LIST_TRAVERSE(&ofl->ofl_objs, lnp, _ifl)) 2372 if (strcmp(_ifl->ifl_name, reference) == 0) { 2373 ifl = _ifl; 2374 break; 2375 } 2376 2377 /* 2378 * If no descriptor exists create one. 2379 */ 2380 if (ifl == 0) { 2381 if ((ifl = libld_calloc(sizeof (Ifl_desc), 1)) == 2382 (Ifl_desc *)0) 2383 return ((Sym_desc *)S_ERROR); 2384 ifl->ifl_name = reference; 2385 ifl->ifl_flags = FLG_IF_NEEDED | FLG_IF_FILEREF; 2386 if ((ifl->ifl_ehdr = libld_calloc(sizeof (Ehdr), 2387 1)) == 0) 2388 return ((Sym_desc *)S_ERROR); 2389 ifl->ifl_ehdr->e_type = ET_REL; 2390 2391 if (list_appendc(&ofl->ofl_objs, ifl) == 0) 2392 return ((Sym_desc *)S_ERROR); 2393 } 2394 2395 /* 2396 * Allocate a symbol structure and add it to the global symbol table. 2397 */ 2398 if ((sym = libld_calloc(sizeof (Sym), 1)) == 0) 2399 return ((Sym_desc *)S_ERROR); 2400 sym->st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); 2401 sym->st_shndx = SHN_UNDEF; 2402 2403 DBG_CALL(Dbg_syms_process(ofl->ofl_lml, ifl)); 2404 DBG_CALL(Dbg_syms_global(ofl->ofl_lml, 0, name)); 2405 sdp = ld_sym_enter(name, sym, hash, ifl, ofl, 0, SHN_UNDEF, 2406 0, 0, &where); 2407 sdp->sd_flags &= ~FLG_SY_CLEAN; 2408 sdp->sd_flags |= FLG_SY_CMDREF; 2409 2410 return (sdp); 2411 } 2412