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 2006 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(__i386) || defined(__amd64)) && 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 are tagged to 374 * prevent direct binding to them. 375 */ 376 if ((ofl->ofl_flags1 & FLG_OF1_ALNODIR) && 377 (nsym->st_shndx != SHN_UNDEF)) 378 sdp->sd_flags1 |= FLG_SY1_NDIR; 379 380 } else { 381 sdp->sd_ref = REF_DYN_SEEN; 382 383 /* 384 * Record the binding file for this symbol in the sa_bindto 385 * field. If this symbol is ever overridden by a REF_REL_NEED 386 * definition, sa_bindto is used when building a 'translator'. 387 */ 388 if (nsym->st_shndx != SHN_UNDEF) 389 sdp->sd_aux->sa_bindto = ifl; 390 391 /* 392 * If this is a protected symbol, mark it. 393 */ 394 if (ELF_ST_VISIBILITY(nsym->st_other) == STV_PROTECTED) 395 sdp->sd_flags |= FLG_SY_PROT; 396 397 /* 398 * Mask out any visibility info from a DYN symbol. 399 */ 400 nsym->st_other = nsym->st_other & ~MSK_SYM_VISIBILITY; 401 402 /* 403 * If the new symbol is from a shared library and it 404 * is associated with a SHT_NOBITS section then this 405 * symbol originated from a tentative symbol. 406 */ 407 if (sdp->sd_isc && 408 (sdp->sd_isc->is_shdr->sh_type == SHT_NOBITS)) 409 sdp->sd_flags |= FLG_SY_TENTSYM; 410 } 411 412 /* 413 * Reclassify any SHN_SUNW_IGNORE symbols to SHN_UNDEF so as to 414 * simplify future processing. 415 */ 416 if (nsym->st_shndx == SHN_SUNW_IGNORE) { 417 sdp->sd_shndx = shndx = SHN_UNDEF; 418 sdp->sd_flags |= FLG_SY_REDUCED; 419 sdp->sd_flags1 |= 420 (FLG_SY1_IGNORE | FLG_SY1_LOCL | FLG_SY1_ELIM); 421 } 422 423 /* 424 * If this is an undefined, or common symbol from a relocatable object 425 * determine whether it is a global or weak reference (see build_osym(), 426 * where REF_DYN_NEED definitions are returned back to undefines). 427 */ 428 if ((etype == ET_REL) && 429 (ELF_ST_BIND(nsym->st_info) == STB_GLOBAL) && 430 ((nsym->st_shndx == SHN_UNDEF) || ((sdflags & FLG_SY_SPECSEC) && 431 #if (defined(__i386) || defined(__amd64)) && defined(_ELF64) 432 ((nsym->st_shndx == SHN_COMMON) || 433 (nsym->st_shndx == SHN_X86_64_LCOMMON))))) 434 #else 435 (nsym->st_shndx == SHN_COMMON)))) 436 #endif 437 sdp->sd_flags |= FLG_SY_GLOBREF; 438 439 /* 440 * Record the input filename on the referenced or defined files list 441 * for possible later diagnostics. The `sa_rfile' pointer contains the 442 * name of the file that first referenced this symbol and is used to 443 * generate undefined symbol diagnostics (refer to sym_undef_entry()). 444 * Note that this entry can be overridden if a reference from a 445 * relocatable object is found after a reference from a shared object 446 * (refer to sym_override()). 447 * The `sa_dfiles' list is used to maintain the list of files that 448 * define the same symbol. This list can be used for two reasons: 449 * 450 * o To save the first definition of a symbol that is not available 451 * for this link-edit. 452 * 453 * o To save all definitions of a symbol when the -m option is in 454 * effect. This is optional as it is used to list multiple 455 * (interposed) definitions of a symbol (refer to ldmap_out()), 456 * and can be quite expensive. 457 */ 458 if (nsym->st_shndx == SHN_UNDEF) { 459 sap->sa_rfile = ifl->ifl_name; 460 } else { 461 if (sdp->sd_ref == REF_DYN_SEEN) { 462 /* 463 * A symbol is determined to be unavailable if it 464 * belongs to a version of a shared object that this 465 * user does not wish to use, or if it belongs to an 466 * implicit shared object. 467 */ 468 if (ifl->ifl_vercnt) { 469 Ver_index * vip; 470 Half vndx = ifl->ifl_versym[ndx]; 471 472 sap->sa_dverndx = vndx; 473 vip = &ifl->ifl_verndx[vndx]; 474 if (!(vip->vi_flags & FLG_VER_AVAIL)) { 475 sdp->sd_flags |= FLG_SY_NOTAVAIL; 476 sap->sa_vfile = ifl->ifl_name; 477 } 478 } 479 if (!(ifl->ifl_flags & FLG_IF_NEEDED)) 480 sdp->sd_flags |= FLG_SY_NOTAVAIL; 481 482 } else if (etype == ET_REL) { 483 /* 484 * If this symbol has been obtained from a versioned 485 * input relocatable object then the new symbol must be 486 * promoted to the versioning of the output file. 487 */ 488 if (ifl->ifl_versym) 489 ld_vers_promote(sdp, ndx, ifl, ofl); 490 } 491 492 if ((ofl->ofl_flags & FLG_OF_GENMAP) && 493 ((sdflags & FLG_SY_SPECSEC) == 0)) 494 if (list_appendc(&sap->sa_dfiles, ifl->ifl_name) == 0) 495 return ((Sym_desc *)S_ERROR); 496 } 497 498 DBG_CALL(Dbg_syms_entered(ofl, nsym, sdp)); 499 return (sdp); 500 } 501 502 /* 503 * Add a special symbol to the symbol table. Takes special symbol name with 504 * and without underscores. This routine is called, after all other symbol 505 * resolution has completed, to generate a reserved absolute symbol (the 506 * underscore version). Special symbols are updated with the appropriate 507 * values in update_osym(). If the user has already defined this symbol 508 * issue a warning and leave the symbol as is. If the non-underscore symbol 509 * is referenced then turn it into a weak alias of the underscored symbol. 510 * 511 * If this is a global symbol, and it hasn't explicitly been defined as being 512 * directly bound to, indicate that it can't be directly bound to. 513 * Historically, most special symbols only have meaning to the object in which 514 * they exist, however, they've always been global. To ensure compatibility 515 * with any unexpected use presently in effect, ensure these symbols don't get 516 * directly bound to. Note, that establishing this state here isn't sufficient 517 * to create a syminfo table, only if a syminfo table is being created by some 518 * other symbol directives will the nodirect binding be recorded. This ensures 519 * we don't create syminfo sections for all objects we create, as this might add 520 * unnecessary bloat to users who haven't explicitly requested extra symbol 521 * information. 522 */ 523 static uintptr_t 524 sym_add_spec(const char *name, const char *uname, Word sdaux_id, 525 Half flags1, Ofl_desc *ofl) 526 { 527 Sym_desc *sdp; 528 Sym_desc *usdp; 529 Sym *sym; 530 Word hash; 531 avl_index_t where; 532 533 /* LINTED */ 534 hash = (Word)elf_hash(uname); 535 if (usdp = ld_sym_find(uname, hash, &where, ofl)) { 536 /* 537 * If the underscore symbol exists and is undefined, or was 538 * defined in a shared library, convert it to a local symbol. 539 * Otherwise leave it as is and warn the user. 540 */ 541 if ((usdp->sd_shndx == SHN_UNDEF) || 542 (usdp->sd_ref != REF_REL_NEED)) { 543 usdp->sd_ref = REF_REL_NEED; 544 usdp->sd_shndx = usdp->sd_sym->st_shndx = SHN_ABS; 545 usdp->sd_flags |= FLG_SY_SPECSEC; 546 usdp->sd_sym->st_info = 547 ELF_ST_INFO(STB_GLOBAL, STT_OBJECT); 548 usdp->sd_isc = NULL; 549 usdp->sd_sym->st_size = 0; 550 usdp->sd_sym->st_value = 0; 551 /* LINTED */ 552 usdp->sd_aux->sa_symspec = (Half)sdaux_id; 553 554 /* 555 * If a user hasn't specifically indicated the scope of 556 * this symbol be made local then leave it as global 557 * (ie. prevent automatic scoping). 558 */ 559 if (!(usdp->sd_flags1 & FLG_SY1_LOCL) && 560 (flags1 & FLG_SY1_GLOB)) { 561 usdp->sd_aux->sa_overndx = VER_NDX_GLOBAL; 562 if ((usdp->sd_flags1 & FLG_SY1_DIR) == 0) 563 usdp->sd_flags1 |= FLG_SY1_NDIR; 564 } 565 usdp->sd_flags1 |= flags1; 566 567 /* 568 * If the reference originated from a mapfile ensure 569 * we mark the symbol as used. 570 */ 571 if (usdp->sd_flags & FLG_SY_MAPREF) 572 usdp->sd_flags |= FLG_SY_MAPUSED; 573 574 DBG_CALL(Dbg_syms_updated(ofl, usdp, uname)); 575 } else 576 eprintf(ofl->ofl_lml, ERR_WARNING, 577 MSG_INTL(MSG_SYM_RESERVE), uname, 578 usdp->sd_file->ifl_name); 579 } else { 580 /* 581 * If the symbol does not exist create it. 582 */ 583 if ((sym = libld_calloc(sizeof (Sym), 1)) == 0) 584 return (S_ERROR); 585 sym->st_shndx = SHN_ABS; 586 sym->st_info = ELF_ST_INFO(STB_GLOBAL, STT_OBJECT); 587 sym->st_size = 0; 588 sym->st_value = 0; 589 DBG_CALL(Dbg_syms_created(ofl->ofl_lml, uname)); 590 if ((usdp = ld_sym_enter(uname, sym, hash, (Ifl_desc *)NULL, 591 ofl, 0, SHN_ABS, FLG_SY_SPECSEC, 0, &where)) == 592 (Sym_desc *)S_ERROR) 593 return (S_ERROR); 594 usdp->sd_ref = REF_REL_NEED; 595 /* LINTED */ 596 usdp->sd_aux->sa_symspec = (Half)sdaux_id; 597 598 usdp->sd_aux->sa_overndx = VER_NDX_GLOBAL; 599 if (flags1 & FLG_SY1_GLOB) 600 usdp->sd_flags1 |= FLG_SY1_NDIR; 601 usdp->sd_flags1 |= flags1; 602 } 603 604 if (name && (sdp = ld_sym_find(name, SYM_NOHASH, 0, ofl)) && 605 (sdp->sd_sym->st_shndx == SHN_UNDEF)) { 606 uchar_t bind; 607 608 /* 609 * If the non-underscore symbol exists and is undefined 610 * convert it to be a local. If the underscore has 611 * sa_symspec set (ie. it was created above) then simulate this 612 * as a weak alias. 613 */ 614 sdp->sd_ref = REF_REL_NEED; 615 sdp->sd_shndx = sdp->sd_sym->st_shndx = SHN_ABS; 616 sdp->sd_flags |= FLG_SY_SPECSEC; 617 sdp->sd_isc = NULL; 618 sdp->sd_sym->st_size = 0; 619 sdp->sd_sym->st_value = 0; 620 /* LINTED */ 621 sdp->sd_aux->sa_symspec = (Half)sdaux_id; 622 if (usdp->sd_aux->sa_symspec) { 623 usdp->sd_aux->sa_linkndx = 0; 624 sdp->sd_aux->sa_linkndx = 0; 625 bind = STB_WEAK; 626 } else 627 bind = STB_GLOBAL; 628 sdp->sd_sym->st_info = ELF_ST_INFO(bind, STT_OBJECT); 629 630 /* 631 * If a user hasn't specifically indicated the scope of 632 * this symbol be made local then leave it as global 633 * (ie. prevent automatic scoping). 634 */ 635 if (!(sdp->sd_flags1 & FLG_SY1_LOCL) && 636 (flags1 & FLG_SY1_GLOB)) { 637 sdp->sd_aux->sa_overndx = VER_NDX_GLOBAL; 638 if ((sdp->sd_flags1 & FLG_SY1_DIR) == 0) 639 sdp->sd_flags1 |= FLG_SY1_NDIR; 640 } 641 sdp->sd_flags1 |= flags1; 642 643 /* 644 * If the reference originated from a mapfile ensure 645 * we mark the symbol as used. 646 */ 647 if (sdp->sd_flags & FLG_SY_MAPREF) 648 sdp->sd_flags |= FLG_SY_MAPUSED; 649 650 DBG_CALL(Dbg_syms_updated(ofl, sdp, name)); 651 } 652 return (1); 653 } 654 655 656 /* 657 * Print undefined symbols. 658 */ 659 static Boolean undef_title = TRUE; 660 661 static void 662 sym_undef_title(Ofl_desc *ofl) 663 { 664 eprintf(ofl->ofl_lml, ERR_NONE, MSG_INTL(MSG_SYM_FMT_UNDEF), 665 MSG_INTL(MSG_SYM_UNDEF_ITM_11), 666 MSG_INTL(MSG_SYM_UNDEF_ITM_21), 667 MSG_INTL(MSG_SYM_UNDEF_ITM_12), 668 MSG_INTL(MSG_SYM_UNDEF_ITM_22)); 669 670 undef_title = FALSE; 671 } 672 673 /* 674 * Undefined symbols can fall into one of four types: 675 * 676 * o the symbol is really undefined (SHN_UNDEF). 677 * 678 * o versioning has been enabled, however this symbol has not been assigned 679 * to one of the defined versions. 680 * 681 * o the symbol has been defined by an implicitly supplied library, ie. one 682 * which was encounted because it was NEEDED by another library, rather 683 * than from a command line supplied library which would become the only 684 * dependency of the output file being produced. 685 * 686 * o the symbol has been defined by a version of a shared object that is 687 * not permitted for this link-edit. 688 * 689 * In all cases the file who made the first reference to this symbol will have 690 * been recorded via the `sa_rfile' pointer. 691 */ 692 typedef enum { 693 UNDEF, NOVERSION, IMPLICIT, NOTAVAIL, 694 BNDLOCAL 695 } Type; 696 697 static const Msg format[] = { 698 MSG_SYM_UND_UNDEF, /* MSG_INTL(MSG_SYM_UND_UNDEF) */ 699 MSG_SYM_UND_NOVER, /* MSG_INTL(MSG_SYM_UND_NOVER) */ 700 MSG_SYM_UND_IMPL, /* MSG_INTL(MSG_SYM_UND_IMPL) */ 701 MSG_SYM_UND_NOTA, /* MSG_INTL(MSG_SYM_UND_NOTA) */ 702 MSG_SYM_UND_BNDLOCAL /* MSG_INTL(MSG_SYM_UND_BNDLOCAL) */ 703 }; 704 705 static void 706 sym_undef_entry(Ofl_desc *ofl, Sym_desc *sdp, Type type) 707 { 708 const char *name1, *name2, *name3; 709 Ifl_desc *ifl = sdp->sd_file; 710 Sym_aux *sap = sdp->sd_aux; 711 712 if (undef_title) 713 sym_undef_title(ofl); 714 715 switch (type) { 716 case UNDEF: 717 case BNDLOCAL: 718 name1 = sap->sa_rfile; 719 break; 720 case NOVERSION: 721 name1 = ifl->ifl_name; 722 break; 723 case IMPLICIT: 724 name1 = sap->sa_rfile; 725 name2 = ifl->ifl_name; 726 break; 727 case NOTAVAIL: 728 name1 = sap->sa_rfile; 729 name2 = sap->sa_vfile; 730 name3 = ifl->ifl_verndx[sap->sa_dverndx].vi_name; 731 break; 732 default: 733 return; 734 } 735 736 eprintf(ofl->ofl_lml, ERR_NONE, MSG_INTL(format[type]), 737 demangle(sdp->sd_name), name1, name2, name3); 738 } 739 740 /* 741 * At this point all symbol input processing has been completed, therefore 742 * complete the symbol table entries by generating any necessary internal 743 * symbols. 744 */ 745 uintptr_t 746 ld_sym_spec(Ofl_desc *ofl) 747 { 748 Word flags = ofl->ofl_flags; 749 750 if (!(flags & FLG_OF_RELOBJ)) { 751 752 DBG_CALL(Dbg_syms_spec_title(ofl->ofl_lml)); 753 754 if (sym_add_spec(MSG_ORIG(MSG_SYM_ETEXT), 755 MSG_ORIG(MSG_SYM_ETEXT_U), SDAUX_ID_ETEXT, 756 FLG_SY1_GLOB, ofl) == S_ERROR) 757 return (S_ERROR); 758 if (sym_add_spec(MSG_ORIG(MSG_SYM_EDATA), 759 MSG_ORIG(MSG_SYM_EDATA_U), SDAUX_ID_EDATA, 760 FLG_SY1_GLOB, ofl) == S_ERROR) 761 return (S_ERROR); 762 if (sym_add_spec(MSG_ORIG(MSG_SYM_END), 763 MSG_ORIG(MSG_SYM_END_U), SDAUX_ID_END, 764 FLG_SY1_GLOB, ofl) == S_ERROR) 765 return (S_ERROR); 766 if (sym_add_spec(MSG_ORIG(MSG_SYM_L_END), 767 MSG_ORIG(MSG_SYM_L_END_U), SDAUX_ID_END, 768 FLG_SY1_LOCL, ofl) == S_ERROR) 769 return (S_ERROR); 770 if (sym_add_spec(MSG_ORIG(MSG_SYM_L_START), 771 MSG_ORIG(MSG_SYM_L_START_U), SDAUX_ID_START, 772 FLG_SY1_LOCL, ofl) == S_ERROR) 773 return (S_ERROR); 774 775 /* 776 * Historically we've always produced a _DYNAMIC symbol, even 777 * for static executables (in which case its value will be 0). 778 */ 779 if (sym_add_spec(MSG_ORIG(MSG_SYM_DYNAMIC), 780 MSG_ORIG(MSG_SYM_DYNAMIC_U), SDAUX_ID_DYN, 781 FLG_SY1_GLOB, ofl) == S_ERROR) 782 return (S_ERROR); 783 784 if ((flags & (FLG_OF_DYNAMIC | FLG_OF_RELOBJ)) == 785 FLG_OF_DYNAMIC) 786 if (sym_add_spec(MSG_ORIG(MSG_SYM_PLKTBL), 787 MSG_ORIG(MSG_SYM_PLKTBL_U), SDAUX_ID_PLT, 788 FLG_SY1_GLOB, ofl) == S_ERROR) 789 return (S_ERROR); 790 791 if (ld_sym_find(MSG_ORIG(MSG_SYM_GOFTBL_U), SYM_NOHASH, 0, ofl)) 792 if (sym_add_spec(MSG_ORIG(MSG_SYM_GOFTBL), 793 MSG_ORIG(MSG_SYM_GOFTBL_U), SDAUX_ID_GOT, 794 FLG_SY1_GLOB, ofl) == S_ERROR) 795 return (S_ERROR); 796 } 797 return (1); 798 } 799 800 /* 801 * This routine checks to see if a symbols visibility needs to be reduced to 802 * either SYMBOLIC or LOCAL. This routine can be called from either 803 * reloc_init() or sym_validate(). 804 */ 805 void 806 ld_sym_adjust_vis(Sym_desc *sdp, Ofl_desc *ofl) 807 { 808 Word symvis, oflags = ofl->ofl_flags, oflags1 = ofl->ofl_flags1; 809 Sym *sym = sdp->sd_sym; 810 811 if ((sdp->sd_ref == REF_REL_NEED) && 812 (sdp->sd_sym->st_shndx != SHN_UNDEF)) { 813 /* 814 * If scoping is enabled, reduce any nonversioned global 815 * symbols (any symbol that has been processed for relocations 816 * will have already had this same reduction test applied). 817 * Indicate that the symbol has been reduced as it may be 818 * necessary to print these symbols later. 819 */ 820 if (((oflags & FLG_OF_AUTOLCL) || 821 (oflags1 & FLG_OF1_AUTOELM)) && 822 ((sdp->sd_flags1 & MSK_SY1_DEFINED) == 0)) { 823 824 sdp->sd_flags |= FLG_SY_REDUCED; 825 sdp->sd_flags1 |= FLG_SY1_LOCL; 826 827 if (ELF_ST_VISIBILITY(sym->st_other) != STV_INTERNAL) 828 sym->st_other = STV_HIDDEN | 829 (sym->st_other & ~MSK_SYM_VISIBILITY); 830 831 if (ofl->ofl_flags1 & 832 (FLG_OF1_REDLSYM | FLG_OF1_AUTOELM)) 833 sdp->sd_flags1 |= FLG_SY1_ELIM; 834 } 835 836 /* 837 * If '-Bsymbolic' is in effect - then bind all global symbols 838 * 'symbolically' and assign the STV_PROTECTED visibility 839 * attribute. 840 */ 841 if ((oflags & FLG_OF_SYMBOLIC) && 842 ((sdp->sd_flags1 & FLG_SY1_LOCL) == 0)) { 843 844 sdp->sd_flags1 |= FLG_SY1_PROT; 845 if (ELF_ST_VISIBILITY(sym->st_other) == STV_DEFAULT) 846 sym->st_other = STV_PROTECTED | 847 (sym->st_other & ~MSK_SYM_VISIBILITY); 848 } 849 } 850 851 /* 852 * Check to see if the symbol visibility needs to be adjusted due to any 853 * STV_* symbol attributes being set. 854 * 855 * STV_PROTECTED == symbolic binding 856 * STV_INTERNAL == reduce to local 857 * STV_HIDDEN == reduce to local 858 * 859 * Note, UNDEF symbols can be assigned a visibility, thus the refencing 860 * code can be dependent on this visibility. Here, by only ignoring 861 * REF_DYN_SEEN symbol definitions we can be assigning a visibility to 862 * REF_DYN_NEED. If the protected, or local assignment is made to 863 * a REF_DYN_NEED symbol, it will be caught later as an illegal 864 * visibility. 865 */ 866 if (!(oflags & FLG_OF_RELOBJ) && (sdp->sd_ref != REF_DYN_SEEN) && 867 (symvis = ELF_ST_VISIBILITY(sym->st_other))) { 868 if (symvis == STV_PROTECTED) 869 sdp->sd_flags1 |= FLG_SY1_PROT; 870 else if ((symvis == STV_INTERNAL) || (symvis == STV_HIDDEN)) 871 sdp->sd_flags1 |= FLG_SY1_LOCL; 872 } 873 874 /* 875 * Indicate that this symbol has had it's visibility checked so that 876 * we don't need to do this investigation again. 877 */ 878 sdp->sd_flags |= FLG_SY_VISIBLE; 879 } 880 881 /* 882 * Make sure a symbol definition is local to the object being built. 883 */ 884 static int 885 ensure_sym_local(Ofl_desc *ofl, Sym_desc *sdp, const char *str) 886 { 887 if (sdp->sd_sym->st_shndx == SHN_UNDEF) { 888 if (str) { 889 eprintf(ofl->ofl_lml, ERR_FATAL, 890 MSG_INTL(MSG_SYM_UNDEF), str, 891 demangle((char *)sdp->sd_name)); 892 } 893 return (1); 894 } 895 if (sdp->sd_ref != REF_REL_NEED) { 896 if (str) { 897 eprintf(ofl->ofl_lml, ERR_FATAL, 898 MSG_INTL(MSG_SYM_EXTERN), str, 899 demangle((char *)sdp->sd_name), 900 sdp->sd_file->ifl_name); 901 } 902 return (1); 903 } 904 905 sdp->sd_flags |= FLG_SY_UPREQD; 906 if (sdp->sd_isc) { 907 sdp->sd_isc->is_flags |= FLG_IS_SECTREF; 908 sdp->sd_isc->is_file->ifl_flags |= FLG_IF_FILEREF; 909 } 910 return (0); 911 } 912 913 /* 914 * Make sure all the symbol definitions required for initarray, finiarray, or 915 * preinitarray's are local to the object being built. 916 */ 917 static int 918 ensure_array_local(Ofl_desc *ofl, List *list, const char *str) 919 { 920 Listnode *lnp; 921 Sym_desc *sdp; 922 int ret = 0; 923 924 for (LIST_TRAVERSE(list, lnp, sdp)) 925 ret += ensure_sym_local(ofl, sdp, str); 926 927 return (ret); 928 } 929 930 /* 931 * After all symbol table input processing has been finished, and all relocation 932 * counting has been carried out (ie. no more symbols will be read, generated, 933 * or modified), validate and count the relevant entries: 934 * 935 * o check and print any undefined symbols remaining. Note that 936 * if a symbol has been defined by virtue of the inclusion of 937 * an implicit shared library, it is still classed as undefined. 938 * 939 * o count the number of global needed symbols together with the 940 * size of their associated name strings (if scoping has been 941 * indicated these symbols may be reduced to locals). 942 * 943 * o establish the size and alignment requirements for the global 944 * .bss section (the alignment of this section is based on the 945 * first symbol that it will contain). 946 */ 947 uintptr_t 948 ld_sym_validate(Ofl_desc *ofl) 949 { 950 Sym_avlnode *sav; 951 Sym_desc *sdp; 952 Sym *sym; 953 Word oflags = ofl->ofl_flags; 954 Word undef = 0, needed = 0, verdesc = 0; 955 Xword bssalign = 0, tlsalign = 0; 956 Xword bsssize = 0, tlssize = 0; 957 #if (defined(__i386) || defined(__amd64)) && defined(_ELF64) 958 Xword lbssalign = 0, lbsssize = 0; 959 #endif 960 int ret; 961 962 /* 963 * If a symbol is undefined and this link-edit calls for no undefined 964 * symbols to remain (this is the default case when generating an 965 * executable but can be enforced for any object using -z defs), the 966 * symbol is classified as undefined and a fatal error condition will 967 * be indicated. 968 * 969 * If the symbol is undefined and we're creating a shared object with 970 * the -Bsymbolic flag, then the symbol is also classified as undefined 971 * and a warning condition will be indicated. 972 */ 973 if ((oflags & (FLG_OF_SHAROBJ | FLG_OF_SYMBOLIC)) == 974 (FLG_OF_SHAROBJ | FLG_OF_SYMBOLIC)) 975 undef = FLG_OF_WARN; 976 if (oflags & FLG_OF_NOUNDEF) 977 undef = FLG_OF_FATAL; 978 979 /* 980 * If the symbol is referenced from an implicitly included shared object 981 * (ie. it's not on the NEEDED list) then the symbol is also classified 982 * as undefined and a fatal error condition will be indicated. 983 */ 984 if ((oflags & FLG_OF_NOUNDEF) || !(oflags & FLG_OF_SHAROBJ)) 985 needed = FLG_OF_FATAL; 986 987 /* 988 * If the output image is being versioned all symbol definitions must be 989 * associated with a version. Any symbol that isn't is classified as 990 * undefined and a fatal error condition will be indicated. 991 */ 992 if ((oflags & FLG_OF_VERDEF) && (ofl->ofl_vercnt > VER_NDX_GLOBAL)) 993 verdesc = FLG_OF_FATAL; 994 995 /* 996 * Collect and validate the globals from the internal symbol table. 997 */ 998 for (sav = avl_first(&ofl->ofl_symavl); sav; 999 sav = AVL_NEXT(&ofl->ofl_symavl, sav)) { 1000 Is_desc * isp; 1001 int undeferr = 0; 1002 1003 sdp = sav->sav_symdesc; 1004 1005 /* 1006 * If undefined symbols are allowed ignore any symbols that are 1007 * not needed. 1008 */ 1009 if (!(oflags & FLG_OF_NOUNDEF) && 1010 (sdp->sd_ref == REF_DYN_SEEN)) 1011 continue; 1012 1013 /* 1014 * If the symbol originates from an external or parent mapfile 1015 * reference and hasn't been matched to a reference from a 1016 * relocatable object, ignore it. 1017 */ 1018 if ((sdp->sd_flags & (FLG_SY_EXTERN | FLG_SY_PARENT)) && 1019 ((sdp->sd_flags & FLG_SY_MAPUSED) == 0)) { 1020 sdp->sd_flags |= FLG_SY_INVALID; 1021 continue; 1022 } 1023 1024 sym = sdp->sd_sym; 1025 1026 /* 1027 * Sanity check TLS. 1028 */ 1029 if ((ELF_ST_TYPE(sym->st_info) == STT_TLS) && 1030 (sym->st_size != 0) && (sym->st_shndx != SHN_UNDEF) && 1031 (sym->st_shndx != SHN_COMMON)) { 1032 Is_desc * isp = sdp->sd_isc; 1033 Ifl_desc * ifl = sdp->sd_file; 1034 1035 if ((isp == 0) || (isp->is_shdr == 0) || 1036 ((isp->is_shdr->sh_flags & SHF_TLS) == 0)) { 1037 eprintf(ofl->ofl_lml, ERR_FATAL, 1038 MSG_INTL(MSG_SYM_TLS), 1039 demangle(sdp->sd_name), ifl->ifl_name); 1040 ofl->ofl_flags |= FLG_OF_FATAL; 1041 continue; 1042 } 1043 } 1044 1045 if ((sdp->sd_flags & FLG_SY_VISIBLE) == 0) 1046 ld_sym_adjust_vis(sdp, ofl); 1047 1048 if ((sdp->sd_flags & FLG_SY_REDUCED) && 1049 (oflags & FLG_OF_PROCRED)) { 1050 DBG_CALL(Dbg_syms_reduce(ofl, DBG_SYM_REDUCE_GLOBAL, 1051 sdp, 0, 0)); 1052 } 1053 1054 /* 1055 * If building a shared object or executable, and this is a 1056 * non-weak UNDEF symbol with reduced visibility (STV_*), then 1057 * give a fatal error. 1058 */ 1059 if (!(oflags & FLG_OF_RELOBJ) && 1060 ELF_ST_VISIBILITY(sym->st_other) && 1061 (sym->st_shndx == SHN_UNDEF) && 1062 (ELF_ST_BIND(sym->st_info) != STB_WEAK)) { 1063 sym_undef_entry(ofl, sdp, BNDLOCAL); 1064 ofl->ofl_flags |= FLG_OF_FATAL; 1065 continue; 1066 } 1067 1068 /* 1069 * If this symbol is defined in a non-allocatable section, 1070 * reduce it to local symbol. 1071 */ 1072 if (((isp = sdp->sd_isc) != 0) && isp->is_shdr && 1073 ((isp->is_shdr->sh_flags & SHF_ALLOC) == 0)) { 1074 sdp->sd_flags |= FLG_SY_REDUCED; 1075 sdp->sd_flags1 |= FLG_SY1_LOCL; 1076 } 1077 1078 /* 1079 * If this symbol originated as a SHN_SUNW_IGNORE, it will have 1080 * been processed as an SHN_UNDEF. Return the symbol to its 1081 * original index for validation, and propagation to the output 1082 * file. 1083 */ 1084 if (sdp->sd_flags1 & FLG_SY1_IGNORE) 1085 sdp->sd_shndx = SHN_SUNW_IGNORE; 1086 1087 if (undef) { 1088 /* 1089 * If an non-weak reference remains undefined, or if a 1090 * mapfile reference is not bound to the relocatable 1091 * objects that make up the object being built, we have 1092 * a fatal error. 1093 * 1094 * The exceptions are symbols which are defined to be 1095 * found in the parent (FLG_SY_PARENT), which is really 1096 * only meaningful for direct binding, or are defined 1097 * external (FLG_SY_EXTERN) so as to suppress -zdefs 1098 * errors. 1099 * 1100 * Register symbols are always allowed to be UNDEF. 1101 * 1102 * Note that we don't include references created via -u 1103 * in the same shared object binding test. This is for 1104 * backward compatibility, in that a number of archive 1105 * makefile rules used -u to cause archive extraction. 1106 * These same rules have been cut and pasted to apply 1107 * to shared objects, and thus although the -u reference 1108 * is redundant, flagging it as fatal could cause some 1109 * build to fail. Also we have documented the use of 1110 * -u as a mechanism to cause binding to weak version 1111 * definitions, thus giving users an error condition 1112 * would be incorrect. 1113 */ 1114 if (!(sdp->sd_flags & FLG_SY_REGSYM) && 1115 ((sym->st_shndx == SHN_UNDEF) && 1116 ((ELF_ST_BIND(sym->st_info) != STB_WEAK) && 1117 ((sdp->sd_flags & 1118 (FLG_SY_PARENT | FLG_SY_EXTERN)) == 0)) || 1119 (((sdp->sd_flags & 1120 (FLG_SY_MAPREF | FLG_SY_MAPUSED)) == 1121 FLG_SY_MAPREF) && 1122 ((sdp->sd_flags1 & (FLG_SY1_LOCL | 1123 FLG_SY1_PROT)) == 0)))) { 1124 sym_undef_entry(ofl, sdp, UNDEF); 1125 ofl->ofl_flags |= undef; 1126 undeferr = 1; 1127 } 1128 1129 } else { 1130 /* 1131 * For building things like shared objects (or anything 1132 * -znodefs), undefined symbols are allowed. 1133 * 1134 * If a mapfile reference remains undefined the user 1135 * would probably like a warning at least (they've 1136 * usually mis-spelt the reference). Refer to the above 1137 * comments for discussion on -u references, which 1138 * are not tested for in the same manner. 1139 */ 1140 if ((sdp->sd_flags & 1141 (FLG_SY_MAPREF | FLG_SY_MAPUSED)) == 1142 FLG_SY_MAPREF) { 1143 sym_undef_entry(ofl, sdp, UNDEF); 1144 ofl->ofl_flags |= FLG_OF_WARN; 1145 undeferr = 1; 1146 } 1147 } 1148 1149 /* 1150 * If this symbol comes from a dependency mark the dependency 1151 * as required (-z ignore can result in unused dependencies 1152 * being dropped). If we need to record dependency versioning 1153 * information indicate what version of the needed shared object 1154 * this symbol is part of. Flag the symbol as undefined if it 1155 * has not been made available to us. 1156 */ 1157 if ((sdp->sd_ref == REF_DYN_NEED) && 1158 (!(sdp->sd_flags & FLG_SY_REFRSD))) { 1159 sdp->sd_file->ifl_flags |= FLG_IF_DEPREQD; 1160 1161 /* 1162 * Capture that we've bound to a symbol that doesn't 1163 * allow being directly bound to. 1164 */ 1165 if (sdp->sd_flags1 & FLG_SY1_NDIR) 1166 ofl->ofl_flags1 |= FLG_OF1_NDIRECT; 1167 1168 if (sdp->sd_file->ifl_vercnt) { 1169 int vndx; 1170 Ver_index * vip; 1171 1172 vndx = sdp->sd_aux->sa_dverndx; 1173 vip = &sdp->sd_file->ifl_verndx[vndx]; 1174 if (vip->vi_flags & FLG_VER_AVAIL) { 1175 vip->vi_flags |= FLG_VER_REFER; 1176 } else { 1177 sym_undef_entry(ofl, sdp, NOTAVAIL); 1178 ofl->ofl_flags |= FLG_OF_FATAL; 1179 continue; 1180 } 1181 } 1182 } 1183 1184 /* 1185 * Test that we do not bind to symbol supplied from an implicit 1186 * shared object. If a binding is from a weak reference it can 1187 * be ignored. 1188 */ 1189 if (needed && !undeferr && (sdp->sd_flags & FLG_SY_GLOBREF) && 1190 (sdp->sd_ref == REF_DYN_NEED) && 1191 (sdp->sd_flags & FLG_SY_NOTAVAIL)) { 1192 sym_undef_entry(ofl, sdp, IMPLICIT); 1193 ofl->ofl_flags |= needed; 1194 continue; 1195 } 1196 1197 /* 1198 * Test that a symbol isn't going to be reduced to local scope 1199 * which actually wants to bind to a shared object - if so it's 1200 * a fatal error. 1201 */ 1202 if ((sdp->sd_ref == REF_DYN_NEED) && 1203 (sdp->sd_flags1 & (FLG_SY1_LOCL | FLG_SY1_PROT))) { 1204 sym_undef_entry(ofl, sdp, BNDLOCAL); 1205 ofl->ofl_flags |= FLG_OF_FATAL; 1206 continue; 1207 } 1208 1209 /* 1210 * If the output image is to be versioned then all symbol 1211 * definitions must be associated with a version. 1212 */ 1213 if (verdesc && (sdp->sd_ref == REF_REL_NEED) && 1214 (sym->st_shndx != SHN_UNDEF) && 1215 (!(sdp->sd_flags1 & FLG_SY1_LOCL)) && 1216 (sdp->sd_aux->sa_overndx == 0)) { 1217 sym_undef_entry(ofl, sdp, NOVERSION); 1218 ofl->ofl_flags |= verdesc; 1219 continue; 1220 } 1221 1222 /* 1223 * If we don't need the symbol there's no need to process it 1224 * any further. 1225 */ 1226 if (sdp->sd_ref == REF_DYN_SEEN) 1227 continue; 1228 1229 /* 1230 * Calculate the size and alignment requirements for the global 1231 * .bss and .tls sections. If we're building a relocatable 1232 * object only account for scoped COMMON symbols (these will 1233 * be converted to .bss references). 1234 * 1235 * For partially initialized symbol, 1236 * if it is expanded, it goes to sunwdata1. 1237 * if it is local, it goes to .bss. 1238 * if the output is shared object, it goes to .sunwbss. 1239 * 1240 * Also refer to make_mvsections() in sunwmove.c 1241 */ 1242 if ((sym->st_shndx == SHN_COMMON) && 1243 (((oflags & FLG_OF_RELOBJ) == 0) || 1244 ((sdp->sd_flags1 & FLG_SY1_LOCL) && 1245 (oflags & FLG_OF_PROCRED)))) { 1246 int countbss = 0; 1247 1248 if (sdp->sd_psyminfo == 0) { 1249 countbss = 1; 1250 } else if ((sdp->sd_flags & FLG_SY_PAREXPN) != 0) { 1251 countbss = 0; 1252 } else if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) { 1253 countbss = 1; 1254 } else if ((ofl->ofl_flags & FLG_OF_SHAROBJ) != 0) { 1255 countbss = 0; 1256 } else 1257 countbss = 1; 1258 1259 if (countbss) { 1260 Xword * size, * align; 1261 1262 if (ELF_ST_TYPE(sym->st_info) != STT_TLS) { 1263 size = &bsssize; 1264 align = &bssalign; 1265 } else { 1266 size = &tlssize; 1267 align = &tlsalign; 1268 } 1269 *size = (Xword)S_ROUND(*size, sym->st_value) + 1270 sym->st_size; 1271 if (sym->st_value > *align) 1272 *align = sym->st_value; 1273 } 1274 } 1275 1276 #if (defined(__i386) || defined(__amd64)) && defined(_ELF64) 1277 /* 1278 * Calculate the size and alignment requirement for the global 1279 * .lbss. TLS or partially initialized symbols do not need to be 1280 * considered yet. 1281 */ 1282 if (sym->st_shndx == SHN_X86_64_LCOMMON) { 1283 lbsssize = (Xword)S_ROUND(lbsssize, sym->st_value) + 1284 sym->st_size; 1285 if (sym->st_value > lbssalign) 1286 lbssalign = sym->st_value; 1287 } 1288 #endif 1289 1290 /* 1291 * If a symbol was referenced via the command line 1292 * (ld -u <>, ...), then this counts as a reference against the 1293 * symbol. Mark any section that symbol is defined in. 1294 */ 1295 if (((isp = sdp->sd_isc) != 0) && 1296 (sdp->sd_flags & FLG_SY_CMDREF)) { 1297 isp->is_flags |= FLG_IS_SECTREF; 1298 isp->is_file->ifl_flags |= FLG_IF_FILEREF; 1299 } 1300 1301 /* 1302 * Update the symbol count and the associated name string size. 1303 * If scoping is in effect for this symbol assign it will be 1304 * assigned to the .symtab/.strtab sections. 1305 */ 1306 if ((sdp->sd_flags1 & FLG_SY1_LOCL) && 1307 (oflags & FLG_OF_PROCRED)) { 1308 /* 1309 * If symbol gets eliminated count it. 1310 * 1311 * If symbol gets reduced to local, 1312 * count it's size for the .symtab. 1313 */ 1314 if (sdp->sd_flags1 & FLG_SY1_ELIM) { 1315 ofl->ofl_elimcnt++; 1316 } else { 1317 ofl->ofl_scopecnt++; 1318 if ((((sdp->sd_flags & FLG_SY_REGSYM) == 0) || 1319 sym->st_name) && (st_insert(ofl->ofl_strtab, 1320 sdp->sd_name) == -1)) 1321 return (S_ERROR); 1322 } 1323 } else { 1324 ofl->ofl_globcnt++; 1325 1326 /* 1327 * If global direct bindings are in effect, or this 1328 * symbol has bound to a dependency which was specified 1329 * as requiring direct bindings, and it hasn't 1330 * explicitly been defined as a non-direct binding 1331 * symbol, mark it. 1332 */ 1333 if (((ofl->ofl_dtflags_1 & DF_1_DIRECT) || (isp && 1334 (isp->is_file->ifl_flags & FLG_IF_DIRECT))) && 1335 ((sdp->sd_flags1 & FLG_SY1_NDIR) == 0)) 1336 sdp->sd_flags1 |= FLG_SY1_DIR; 1337 1338 /* 1339 * Insert the symbol name. 1340 */ 1341 if (((sdp->sd_flags & FLG_SY_REGSYM) == 0) || 1342 sym->st_name) { 1343 if (st_insert(ofl->ofl_strtab, 1344 sdp->sd_name) == -1) 1345 return (S_ERROR); 1346 1347 if (!(ofl->ofl_flags & FLG_OF_RELOBJ) && 1348 (st_insert(ofl->ofl_dynstrtab, 1349 sdp->sd_name) == -1)) 1350 return (S_ERROR); 1351 } 1352 1353 /* 1354 * If this section offers a global symbol - record that 1355 * fact. 1356 */ 1357 if (isp) { 1358 isp->is_flags |= FLG_IS_SECTREF; 1359 isp->is_file->ifl_flags |= FLG_IF_FILEREF; 1360 } 1361 } 1362 } 1363 1364 /* 1365 * If we've encountered a fatal error during symbol validation then 1366 * return now. 1367 */ 1368 if (ofl->ofl_flags & FLG_OF_FATAL) 1369 return (1); 1370 1371 /* 1372 * Now that symbol resolution is completed, scan any register symbols. 1373 * From now on, we're only interested in those that contribute to the 1374 * output file. 1375 */ 1376 if (ofl->ofl_regsyms) { 1377 int ndx; 1378 1379 for (ndx = 0; ndx < ofl->ofl_regsymsno; ndx++) { 1380 if ((sdp = ofl->ofl_regsyms[ndx]) == 0) 1381 continue; 1382 if (sdp->sd_ref != REF_REL_NEED) { 1383 ofl->ofl_regsyms[ndx] = 0; 1384 continue; 1385 } 1386 1387 ofl->ofl_regsymcnt++; 1388 if (sdp->sd_sym->st_name == 0) 1389 sdp->sd_name = MSG_ORIG(MSG_STR_EMPTY); 1390 1391 if ((sdp->sd_flags1 & FLG_SY1_LOCL) || 1392 (ELF_ST_BIND(sdp->sd_sym->st_info) == STB_LOCAL)) 1393 ofl->ofl_lregsymcnt++; 1394 } 1395 } 1396 1397 /* 1398 * Generate the .bss section now that we know its size and alignment. 1399 */ 1400 if (bsssize || !(oflags & FLG_OF_RELOBJ)) { 1401 if (ld_make_bss(ofl, bsssize, bssalign, MAKE_BSS) == S_ERROR) 1402 return (S_ERROR); 1403 } 1404 if (tlssize) { 1405 if (ld_make_bss(ofl, tlssize, tlsalign, MAKE_TLS) == S_ERROR) 1406 return (S_ERROR); 1407 } 1408 #if (defined(__i386) || defined(__amd64)) && defined(_ELF64) 1409 if (lbsssize && !(oflags & FLG_OF_RELOBJ)) { 1410 if (ld_make_bss(ofl, lbsssize, lbssalign, MAKE_LBSS) == S_ERROR) 1411 return (S_ERROR); 1412 } 1413 #endif 1414 1415 /* 1416 * Determine what entry point symbol we need, and if found save its 1417 * symbol descriptor so that we can update the ELF header entry with the 1418 * symbols value later (see update_oehdr). Make sure the symbol is 1419 * tagged to ensure its update in case -s is in effect. Use any -e 1420 * option first, or the default entry points `_start' and `main'. 1421 */ 1422 ret = 0; 1423 if (ofl->ofl_entry) { 1424 if (((sdp = ld_sym_find(ofl->ofl_entry, SYM_NOHASH, 0, 1425 ofl)) != NULL) && (ensure_sym_local(ofl, 1426 sdp, MSG_INTL(MSG_SYM_ENTRY)) == 0)) { 1427 ofl->ofl_entry = (void *)sdp; 1428 } else { 1429 ret++; 1430 } 1431 } else if (((sdp = ld_sym_find(MSG_ORIG(MSG_SYM_START), 1432 SYM_NOHASH, 0, ofl)) != NULL) && (ensure_sym_local(ofl, 1433 sdp, 0) == 0)) { 1434 ofl->ofl_entry = (void *)sdp; 1435 1436 } else if (((sdp = ld_sym_find(MSG_ORIG(MSG_SYM_MAIN), 1437 SYM_NOHASH, 0, ofl)) != NULL) && (ensure_sym_local(ofl, 1438 sdp, 0) == 0)) { 1439 ofl->ofl_entry = (void *)sdp; 1440 } 1441 1442 /* 1443 * If ld -zdtrace=<sym> was given, then validate that the symbol is 1444 * defined within the current object being built. 1445 */ 1446 if ((sdp = ofl->ofl_dtracesym) != 0) { 1447 ret += ensure_sym_local(ofl, sdp, MSG_ORIG(MSG_STR_DTRACE)); 1448 } 1449 1450 /* 1451 * If any initarray, finiarray or preinitarray functions have been 1452 * requested, make sure they are defined within the current object 1453 * being built. 1454 */ 1455 if (ofl->ofl_initarray.head) { 1456 ret += ensure_array_local(ofl, &ofl->ofl_initarray, 1457 MSG_ORIG(MSG_SYM_INITARRAY)); 1458 } 1459 if (ofl->ofl_finiarray.head) { 1460 ret += ensure_array_local(ofl, &ofl->ofl_finiarray, 1461 MSG_ORIG(MSG_SYM_FINIARRAY)); 1462 } 1463 if (ofl->ofl_preiarray.head) { 1464 ret += ensure_array_local(ofl, &ofl->ofl_preiarray, 1465 MSG_ORIG(MSG_SYM_PREINITARRAY)); 1466 } 1467 1468 if (ret) 1469 return (S_ERROR); 1470 1471 /* 1472 * If we're required to record any needed dependencies versioning 1473 * information calculate it now that all symbols have been validated. 1474 */ 1475 if ((oflags & (FLG_OF_VERNEED | FLG_OF_NOVERSEC)) == FLG_OF_VERNEED) 1476 return (ld_vers_check_need(ofl)); 1477 else 1478 return (1); 1479 } 1480 1481 /* 1482 * qsort(3c) comparison function. As an optimization for associating weak 1483 * symbols to their strong counterparts sort global symbols according to their 1484 * address and binding. 1485 */ 1486 static int 1487 compare(const void * sdpp1, const void * sdpp2) 1488 { 1489 Sym_desc * sdp1 = *((Sym_desc **)sdpp1); 1490 Sym_desc * sdp2 = *((Sym_desc **)sdpp2); 1491 Sym * sym1, * sym2; 1492 uchar_t bind1, bind2; 1493 1494 /* 1495 * Symbol descriptors may be zero, move these to the front of the 1496 * sorted array. 1497 */ 1498 if (sdp1 == 0) 1499 return (-1); 1500 if (sdp2 == 0) 1501 return (1); 1502 1503 sym1 = sdp1->sd_sym; 1504 sym2 = sdp2->sd_sym; 1505 1506 /* 1507 * Compare the symbols value (address). 1508 */ 1509 if (sym1->st_value > sym2->st_value) 1510 return (1); 1511 if (sym1->st_value < sym2->st_value) 1512 return (-1); 1513 1514 bind1 = ELF_ST_BIND(sym1->st_info); 1515 bind2 = ELF_ST_BIND(sym2->st_info); 1516 1517 /* 1518 * If two symbols have the same address place the weak symbol before 1519 * any strong counterpart. 1520 */ 1521 if (bind1 > bind2) 1522 return (-1); 1523 if (bind1 < bind2) 1524 return (1); 1525 1526 return (0); 1527 } 1528 1529 1530 /* 1531 * Process the symbol table for the specified input file. At this point all 1532 * input sections from this input file have been assigned an input section 1533 * descriptor which is saved in the `ifl_isdesc' array. 1534 * 1535 * o local symbols are saved (as is) if the input file is a 1536 * relocatable object 1537 * 1538 * o global symbols are added to the linkers internal symbol 1539 * table if they are not already present, otherwise a symbol 1540 * resolution function is called upon to resolve the conflict. 1541 */ 1542 uintptr_t 1543 ld_sym_process(Is_desc *isc, Ifl_desc *ifl, Ofl_desc *ofl) 1544 { 1545 Sym *sym = (Sym *)isc->is_indata->d_buf; 1546 Word *symshndx = 0; 1547 Shdr *shdr = isc->is_shdr; 1548 Sym_desc *sdp; 1549 size_t strsize; 1550 char *strs; 1551 uchar_t type, bind; 1552 Word ndx, hash, local, total; 1553 Half etype = ifl->ifl_ehdr->e_type; 1554 const char *symsecname, *strsecname; 1555 avl_index_t where; 1556 1557 /* 1558 * Its possible that a file may contain more that one symbol table, 1559 * ie. .dynsym and .symtab in a shared library. Only process the first 1560 * table (here, we assume .dynsym comes before .symtab). 1561 */ 1562 if (ifl->ifl_symscnt) 1563 return (1); 1564 1565 if (isc->is_symshndx) 1566 symshndx = isc->is_symshndx->is_indata->d_buf; 1567 1568 DBG_CALL(Dbg_syms_process(ofl->ofl_lml, ifl)); 1569 1570 if (isc->is_name) 1571 symsecname = isc->is_name; 1572 else 1573 symsecname = MSG_ORIG(MSG_STR_EMPTY); 1574 1575 /* 1576 * From the symbol tables section header information determine which 1577 * strtab table is needed to locate the actual symbol names. 1578 */ 1579 if (ifl->ifl_flags & FLG_IF_HSTRTAB) { 1580 ndx = shdr->sh_link; 1581 if ((ndx == 0) || (ndx >= ifl->ifl_shnum)) { 1582 eprintf(ofl->ofl_lml, ERR_FATAL, 1583 MSG_INTL(MSG_FIL_INVSHLINK), 1584 ifl->ifl_name, symsecname, EC_XWORD(ndx)); 1585 return (S_ERROR); 1586 } 1587 strsize = ifl->ifl_isdesc[ndx]->is_shdr->sh_size; 1588 strs = ifl->ifl_isdesc[ndx]->is_indata->d_buf; 1589 if (ifl->ifl_isdesc[ndx]->is_name) 1590 strsecname = ifl->ifl_isdesc[ndx]->is_name; 1591 else 1592 strsecname = MSG_ORIG(MSG_STR_EMPTY); 1593 } else { 1594 /* 1595 * There is no string table section in this input file 1596 * although there are symbols in this symbol table section. 1597 * This means that these symbols do not have names. 1598 * Currently, only scratch register symbols are allowed 1599 * not to have names. 1600 */ 1601 strsize = 0; 1602 strs = (char *)MSG_ORIG(MSG_STR_EMPTY); 1603 strsecname = MSG_ORIG(MSG_STR_EMPTY); 1604 } 1605 1606 /* 1607 * Determine the number of local symbols together with the total 1608 * number we have to process. 1609 */ 1610 total = (Word)(shdr->sh_size / shdr->sh_entsize); 1611 local = shdr->sh_info; 1612 1613 /* 1614 * Allocate a symbol table index array and a local symbol array 1615 * (global symbols are processed and added to the ofl->ofl_symbkt[] 1616 * array). If we are dealing with a relocatable object, allocate the 1617 * local symbol descriptors. If this isn't a relocatable object we 1618 * still have to process any shared object locals to determine if any 1619 * register symbols exist. Although these aren't added to the output 1620 * image, they are used as part of symbol resolution. 1621 */ 1622 if ((ifl->ifl_oldndx = libld_malloc((size_t)(total * 1623 sizeof (Sym_desc *)))) == 0) 1624 return (S_ERROR); 1625 if ((etype == ET_REL) && local) { 1626 if ((ifl->ifl_locs = 1627 libld_calloc(sizeof (Sym_desc), local)) == 0) 1628 return (S_ERROR); 1629 /* LINTED */ 1630 ifl->ifl_locscnt = (Word)local; 1631 } 1632 ifl->ifl_symscnt = total; 1633 1634 /* 1635 * If there are local symbols to save add them to the symbol table 1636 * index array. 1637 */ 1638 if (local) { 1639 for (sym++, ndx = 1; ndx < local; sym++, ndx++) { 1640 Word shndx, sdflags = FLG_SY_CLEAN; 1641 const char *name; 1642 Sym_desc *rsdp; 1643 1644 /* 1645 * Determine the associated section index. 1646 */ 1647 if (symshndx && (sym->st_shndx == SHN_XINDEX)) 1648 shndx = symshndx[ndx]; 1649 else if ((shndx = sym->st_shndx) >= SHN_LORESERVE) 1650 sdflags |= FLG_SY_SPECSEC; 1651 1652 /* 1653 * Check if st_name has a valid value or not. 1654 */ 1655 if ((name = string(ofl, ifl, sym, strs, strsize, ndx, 1656 shndx, symsecname, strsecname, &sdflags)) == 0) { 1657 ofl->ofl_flags |= FLG_OF_FATAL; 1658 continue; 1659 } 1660 1661 /* 1662 * If this local symbol table originates from a shared 1663 * object, then we're only interested in recording 1664 * register symbols. As local symbol descriptors aren't 1665 * allocated for shared objects, one will be allocated 1666 * to associated with the register symbol. This symbol 1667 * won't become part of the output image, but we must 1668 * process it to test for register conflicts. 1669 */ 1670 rsdp = sdp = 0; 1671 if (sdflags & FLG_SY_REGSYM) { 1672 if ((rsdp = ld_reg_find(sym, ofl)) != 0) { 1673 /* 1674 * The fact that another register def- 1675 * inition has been found is fatal. 1676 * Call the verification routine to get 1677 * the error message and move on. 1678 */ 1679 (void) ld_reg_check(rsdp, sym, name, 1680 ifl, ofl); 1681 continue; 1682 } 1683 1684 if (etype == ET_DYN) { 1685 if ((sdp = libld_calloc( 1686 sizeof (Sym_desc), 1)) == 0) 1687 return (S_ERROR); 1688 sdp->sd_ref = REF_DYN_SEEN; 1689 } 1690 } else if (etype == ET_DYN) 1691 continue; 1692 1693 /* 1694 * Fill in the remaining symbol descriptor information. 1695 */ 1696 if (sdp == 0) { 1697 sdp = &(ifl->ifl_locs[ndx]); 1698 sdp->sd_ref = REF_REL_NEED; 1699 } 1700 if (rsdp == 0) { 1701 sdp->sd_name = name; 1702 sdp->sd_sym = sym; 1703 sdp->sd_shndx = shndx; 1704 sdp->sd_flags = sdflags; 1705 sdp->sd_file = ifl; 1706 ifl->ifl_oldndx[ndx] = sdp; 1707 } 1708 1709 DBG_CALL(Dbg_syms_entry(ofl->ofl_lml, ndx, sdp)); 1710 1711 /* 1712 * Reclassify any SHN_SUNW_IGNORE symbols to SHN_UNDEF 1713 * so as to simplify future processing. 1714 */ 1715 if (sym->st_shndx == SHN_SUNW_IGNORE) { 1716 sdp->sd_shndx = shndx = SHN_UNDEF; 1717 sdp->sd_flags1 |= 1718 (FLG_SY1_IGNORE | FLG_SY1_ELIM); 1719 } 1720 1721 /* 1722 * Process any register symbols. 1723 */ 1724 if (sdp->sd_flags & FLG_SY_REGSYM) { 1725 /* 1726 * Add a diagnostic to indicate we've caught a 1727 * register symbol, as this can be useful if a 1728 * register conflict is later discovered. 1729 */ 1730 DBG_CALL(Dbg_syms_entered(ofl, sym, sdp)); 1731 1732 /* 1733 * If this register symbol hasn't already been 1734 * recorded, enter it now. 1735 */ 1736 if ((rsdp == 0) && 1737 (ld_reg_enter(sdp, ofl) == 0)) 1738 return (S_ERROR); 1739 } 1740 1741 /* 1742 * Assign an input section. 1743 */ 1744 if ((sym->st_shndx != SHN_UNDEF) && 1745 ((sdp->sd_flags & FLG_SY_SPECSEC) == 0)) 1746 sdp->sd_isc = ifl->ifl_isdesc[shndx]; 1747 1748 /* 1749 * If this symbol falls within the range of a section 1750 * being discarded, then discard the symbol itself. 1751 * There is no reason to keep this local symbol. 1752 */ 1753 if (sdp->sd_isc && 1754 (sdp->sd_isc->is_flags & FLG_IS_DISCARD)) { 1755 sdp->sd_flags |= FLG_SY_ISDISC; 1756 DBG_CALL(Dbg_syms_discarded(ofl->ofl_lml, 1757 sdp, sdp->sd_isc)); 1758 continue; 1759 } 1760 1761 /* 1762 * Skip any section symbols as new versions of these 1763 * will be created. 1764 */ 1765 if ((type = ELF_ST_TYPE(sym->st_info)) == STT_SECTION) { 1766 if (sym->st_shndx == SHN_UNDEF) { 1767 eprintf(ofl->ofl_lml, ERR_WARNING, 1768 MSG_INTL(MSG_SYM_INVSHNDX), 1769 demangle(sdp->sd_name), 1770 ifl->ifl_name, 1771 conv_sym_shndx(sym->st_shndx)); 1772 } 1773 continue; 1774 } 1775 1776 /* 1777 * Sanity check for TLS 1778 */ 1779 if ((sym->st_size != 0) && ((type == STT_TLS) && 1780 (sym->st_shndx != SHN_COMMON))) { 1781 Is_desc *isp = sdp->sd_isc; 1782 1783 if ((isp == 0) || (isp->is_shdr == 0) || 1784 ((isp->is_shdr->sh_flags & SHF_TLS) == 0)) { 1785 eprintf(ofl->ofl_lml, ERR_FATAL, 1786 MSG_INTL(MSG_SYM_TLS), 1787 demangle(sdp->sd_name), 1788 ifl->ifl_name); 1789 ofl->ofl_flags |= FLG_OF_FATAL; 1790 continue; 1791 } 1792 } 1793 1794 /* 1795 * Carry our some basic sanity checks (these are just 1796 * some of the erroneous symbol entries we've come 1797 * across, there's probably a lot more). The symbol 1798 * will not be carried forward to the output file, which 1799 * won't be a problem unless a relocation is required 1800 * against it. 1801 */ 1802 if (((sdp->sd_flags & FLG_SY_SPECSEC) && 1803 ((sym->st_shndx == SHN_COMMON)) || 1804 ((type == STT_FILE) && 1805 (sym->st_shndx != SHN_ABS))) || 1806 (sdp->sd_isc && (sdp->sd_isc->is_osdesc == 0))) { 1807 eprintf(ofl->ofl_lml, ERR_WARNING, 1808 MSG_INTL(MSG_SYM_INVSHNDX), 1809 demangle(sdp->sd_name), ifl->ifl_name, 1810 conv_sym_shndx(sym->st_shndx)); 1811 sdp->sd_isc = NULL; 1812 sdp->sd_flags |= FLG_SY_INVALID; 1813 continue; 1814 } 1815 1816 /* 1817 * As these local symbols will become part of the output 1818 * image, record their number and name string size. 1819 * Globals are counted after all input file processing 1820 * (and hence symbol resolution) is complete during 1821 * sym_validate(). 1822 */ 1823 if (!(ofl->ofl_flags1 & FLG_OF1_REDLSYM)) { 1824 ofl->ofl_locscnt++; 1825 1826 if ((((sdp->sd_flags & FLG_SY_REGSYM) == 0) || 1827 sym->st_name) && (st_insert(ofl->ofl_strtab, 1828 sdp->sd_name) == -1)) 1829 return (S_ERROR); 1830 } 1831 } 1832 } 1833 1834 /* 1835 * Now scan the global symbols entering them in the internal symbol 1836 * table or resolving them as necessary. 1837 */ 1838 sym = (Sym *)isc->is_indata->d_buf; 1839 sym += local; 1840 /* LINTED */ 1841 for (ndx = (int)local; ndx < total; sym++, ndx++) { 1842 const char *name; 1843 Word shndx, sdflags = 0; 1844 1845 /* 1846 * Determine the associated section index. 1847 */ 1848 if (symshndx && (sym->st_shndx == SHN_XINDEX)) { 1849 shndx = symshndx[ndx]; 1850 } else { 1851 shndx = sym->st_shndx; 1852 if (sym->st_shndx >= SHN_LORESERVE) 1853 sdflags |= FLG_SY_SPECSEC; 1854 } 1855 1856 /* 1857 * Check if st_name has a valid value or not. 1858 */ 1859 if ((name = string(ofl, ifl, sym, strs, strsize, ndx, shndx, 1860 symsecname, strsecname, &sdflags)) == 0) { 1861 ofl->ofl_flags |= FLG_OF_FATAL; 1862 continue; 1863 } 1864 1865 /* 1866 * The linker itself will generate symbols for _end, _etext, 1867 * _edata, _DYNAMIC and _PROCEDURE_LINKAGE_TABLE_, so don't 1868 * bother entering these symbols from shared objects. This 1869 * results in some wasted resolution processing, which is hard 1870 * to feel, but if nothing else, pollutes diagnostic relocation 1871 * output. 1872 */ 1873 if (name[0] && (etype == ET_DYN) && (sym->st_size == 0) && 1874 (ELF_ST_TYPE(sym->st_info) == STT_OBJECT) && 1875 (name[0] == '_') && ((name[1] == 'e') || 1876 (name[1] == 'D') || (name[1] == 'P')) && 1877 ((strcmp(name, MSG_ORIG(MSG_SYM_ETEXT_U)) == 0) || 1878 (strcmp(name, MSG_ORIG(MSG_SYM_EDATA_U)) == 0) || 1879 (strcmp(name, MSG_ORIG(MSG_SYM_END_U)) == 0) || 1880 (strcmp(name, MSG_ORIG(MSG_SYM_DYNAMIC_U)) == 0) || 1881 (strcmp(name, MSG_ORIG(MSG_SYM_PLKTBL_U)) == 0))) { 1882 ifl->ifl_oldndx[ndx] = 0; 1883 continue; 1884 } 1885 1886 /* 1887 * Determine and validate the symbols binding. 1888 */ 1889 bind = ELF_ST_BIND(sym->st_info); 1890 if ((bind != STB_GLOBAL) && (bind != STB_WEAK)) { 1891 eprintf(ofl->ofl_lml, ERR_WARNING, 1892 MSG_INTL(MSG_SYM_NONGLOB), demangle(name), 1893 ifl->ifl_name, conv_sym_info_bind(bind, 0)); 1894 continue; 1895 } 1896 1897 /* 1898 * If this symbol falls within the range of a section being 1899 * discarded, then discard the symbol itself. 1900 */ 1901 if (((sdflags & FLG_SY_SPECSEC) == 0) && 1902 (sym->st_shndx != SHN_UNDEF)) { 1903 Is_desc *isp; 1904 1905 if (shndx >= ifl->ifl_shnum) { 1906 /* 1907 * Carry our some basic sanity checks 1908 * The symbol will not be carried forward to 1909 * the output file, which won't be a problem 1910 * unless a relocation is required against it. 1911 */ 1912 eprintf(ofl->ofl_lml, ERR_WARNING, 1913 MSG_INTL(MSG_SYM_INVSHNDX), demangle(name), 1914 ifl->ifl_name, 1915 conv_sym_shndx(sym->st_shndx)); 1916 continue; 1917 } 1918 1919 isp = ifl->ifl_isdesc[shndx]; 1920 if (isp && (isp->is_flags & FLG_IS_DISCARD)) { 1921 if ((sdp = 1922 libld_calloc(sizeof (Sym_desc), 1)) == 0) 1923 return (S_ERROR); 1924 1925 /* 1926 * Create a dummy symbol entry so that if we 1927 * find any references to this discarded symbol 1928 * we can compensate. 1929 */ 1930 sdp->sd_name = name; 1931 sdp->sd_sym = sym; 1932 sdp->sd_file = ifl; 1933 sdp->sd_isc = isp; 1934 sdp->sd_flags = FLG_SY_ISDISC; 1935 ifl->ifl_oldndx[ndx] = sdp; 1936 1937 DBG_CALL(Dbg_syms_discarded(ofl->ofl_lml, sdp, 1938 sdp->sd_isc)); 1939 continue; 1940 } 1941 } 1942 1943 /* 1944 * If the symbol does not already exist in the internal symbol 1945 * table add it, otherwise resolve the conflict. If the symbol 1946 * from this file is kept, retain its symbol table index for 1947 * possible use in associating a global alias. 1948 */ 1949 /* LINTED */ 1950 hash = (Word)elf_hash((const char *)name); 1951 if ((sdp = ld_sym_find(name, hash, &where, ofl)) == NULL) { 1952 DBG_CALL(Dbg_syms_global(ofl->ofl_lml, ndx, name)); 1953 if ((sdp = ld_sym_enter(name, sym, hash, ifl, ofl, ndx, 1954 shndx, sdflags, 0, &where)) == (Sym_desc *)S_ERROR) 1955 return (S_ERROR); 1956 1957 } else if (ld_sym_resolve(sdp, sym, ifl, ofl, ndx, shndx, 1958 sdflags) == S_ERROR) 1959 return (S_ERROR); 1960 1961 /* 1962 * After we've compared a defined symbol in one shared 1963 * object, flag the symbol so we don't compare it again. 1964 */ 1965 if ((etype == ET_DYN) && (sym->st_shndx != SHN_UNDEF) && 1966 ((sdp->sd_flags & FLG_SY_SOFOUND) == 0)) 1967 sdp->sd_flags |= FLG_SY_SOFOUND; 1968 1969 /* 1970 * If the symbol is accepted from this file retain the symbol 1971 * index for possible use in aliasing. 1972 */ 1973 if (sdp->sd_file == ifl) 1974 sdp->sd_symndx = ndx; 1975 1976 ifl->ifl_oldndx[ndx] = sdp; 1977 1978 /* 1979 * If we've accepted a register symbol, continue to validate 1980 * it. 1981 */ 1982 if (sdp->sd_flags & FLG_SY_REGSYM) { 1983 Sym_desc *rsdp; 1984 1985 if ((rsdp = ld_reg_find(sdp->sd_sym, ofl)) == 0) { 1986 if (ld_reg_enter(sdp, ofl) == 0) 1987 return (S_ERROR); 1988 } else if (rsdp != sdp) { 1989 (void) ld_reg_check(rsdp, sdp->sd_sym, 1990 sdp->sd_name, ifl, ofl); 1991 } 1992 } 1993 } 1994 1995 /* 1996 * If this is a shared object scan the globals one more time and 1997 * associate any weak/global associations. This association is needed 1998 * should the weak definition satisfy a reference in the dynamic 1999 * executable: 2000 * 2001 * o if the symbol is a data item it will be copied to the 2002 * executables address space, thus we must also reassociate the 2003 * alias symbol with its new location in the executable. 2004 * 2005 * o if the symbol is a function then we may need to promote the 2006 * symbols binding from undefined weak to undefined, otherwise the 2007 * run-time linker will not generate the correct relocation error 2008 * should the symbol not be found. 2009 * 2010 * The true association between a weak/strong symbol pair is that both 2011 * symbol entries are identical, thus first we created a sorted symbol 2012 * list keyed off of the symbols value (if the value is the same chances 2013 * are the rest of the symbols data is). This list is then scanned for 2014 * weak symbols, and if one is found then any strong association will 2015 * exist in the following entries. Thus we just have to scan one 2016 * (typical single alias) or more (in the uncommon instance of multiple 2017 * weak to strong associations) entries to determine if a match exists. 2018 */ 2019 if (ifl->ifl_ehdr->e_type == ET_DYN) { 2020 Sym_desc ** sort; 2021 size_t size = (total - local) * sizeof (Sym_desc *); 2022 2023 if ((sort = libld_malloc(size)) == 0) 2024 return (S_ERROR); 2025 (void) memcpy((void *)sort, &ifl->ifl_oldndx[local], size); 2026 2027 qsort(sort, (total - local), sizeof (Sym_desc *), compare); 2028 2029 for (ndx = 0; ndx < (total - local); ndx++) { 2030 Sym_desc * wsdp = sort[ndx]; 2031 Sym * wsym; 2032 int sndx; 2033 2034 if (wsdp == 0) 2035 continue; 2036 2037 wsym = wsdp->sd_sym; 2038 2039 if ((ELF_ST_BIND(wsym->st_info) != STB_WEAK) || 2040 (wsdp->sd_sym->st_shndx == SHN_UNDEF) || 2041 (wsdp->sd_flags & FLG_SY_SPECSEC)) 2042 continue; 2043 2044 /* 2045 * We have a weak symbol, if it has a strong alias it 2046 * will have been sorted to one of the following sort 2047 * table entries. Note that we could have multiple weak 2048 * symbols aliased to one strong (if this occurs then 2049 * the strong symbol only maintains one alias back to 2050 * the last weak). 2051 */ 2052 for (sndx = ndx + 1; sndx < (total - local); sndx++) { 2053 Sym_desc * ssdp = sort[sndx]; 2054 Sym * ssym; 2055 2056 if (ssdp == 0) 2057 break; 2058 2059 ssym = ssdp->sd_sym; 2060 2061 if (wsym->st_value != ssym->st_value) 2062 break; 2063 2064 if ((ssdp->sd_file == ifl) && 2065 (wsdp->sd_file == ifl) && 2066 (wsym->st_size == ssym->st_size) && 2067 (ssdp->sd_sym->st_shndx != SHN_UNDEF) && 2068 (ELF_ST_BIND(ssym->st_info) != STB_WEAK) && 2069 ((ssdp->sd_flags & FLG_SY_SPECSEC) == 0)) { 2070 ssdp->sd_aux->sa_linkndx = 2071 (Word)wsdp->sd_symndx; 2072 wsdp->sd_aux->sa_linkndx = 2073 (Word)ssdp->sd_symndx; 2074 break; 2075 } 2076 } 2077 } 2078 } 2079 return (1); 2080 } 2081 2082 /* 2083 * Add an undefined symbol to the symbol table (ie. from -u name option) 2084 */ 2085 Sym_desc * 2086 ld_sym_add_u(const char *name, Ofl_desc *ofl) 2087 { 2088 Sym *sym; 2089 Ifl_desc *ifl = 0, *_ifl; 2090 Sym_desc *sdp; 2091 Word hash; 2092 Listnode *lnp; 2093 avl_index_t where; 2094 const char *cmdline = MSG_INTL(MSG_STR_COMMAND); 2095 2096 /* 2097 * If the symbol reference already exists indicate that a reference 2098 * also came from the command line. 2099 */ 2100 /* LINTED */ 2101 hash = (Word)elf_hash(name); 2102 if (sdp = ld_sym_find(name, hash, &where, ofl)) { 2103 if (sdp->sd_ref == REF_DYN_SEEN) 2104 sdp->sd_ref = REF_DYN_NEED; 2105 return (sdp); 2106 } 2107 2108 /* 2109 * Determine whether a pseudo input file descriptor exists to represent 2110 * the command line, as any global symbol needs an input file descriptor 2111 * during any symbol resolution (refer to map_ifl() which provides a 2112 * similar method for adding symbols from mapfiles). 2113 */ 2114 for (LIST_TRAVERSE(&ofl->ofl_objs, lnp, _ifl)) 2115 if (strcmp(_ifl->ifl_name, cmdline) == 0) { 2116 ifl = _ifl; 2117 break; 2118 } 2119 2120 /* 2121 * If no descriptor exists create one. 2122 */ 2123 if (ifl == 0) { 2124 if ((ifl = libld_calloc(sizeof (Ifl_desc), 1)) == 2125 (Ifl_desc *)0) 2126 return ((Sym_desc *)S_ERROR); 2127 ifl->ifl_name = cmdline; 2128 ifl->ifl_flags = FLG_IF_NEEDED | FLG_IF_FILEREF; 2129 if ((ifl->ifl_ehdr = libld_calloc(sizeof (Ehdr), 2130 1)) == 0) 2131 return ((Sym_desc *)S_ERROR); 2132 ifl->ifl_ehdr->e_type = ET_REL; 2133 2134 if (list_appendc(&ofl->ofl_objs, ifl) == 0) 2135 return ((Sym_desc *)S_ERROR); 2136 } 2137 2138 /* 2139 * Allocate a symbol structure and add it to the global symbol table. 2140 */ 2141 if ((sym = libld_calloc(sizeof (Sym), 1)) == 0) 2142 return ((Sym_desc *)S_ERROR); 2143 sym->st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); 2144 sym->st_shndx = SHN_UNDEF; 2145 2146 DBG_CALL(Dbg_syms_process(ofl->ofl_lml, ifl)); 2147 DBG_CALL(Dbg_syms_global(ofl->ofl_lml, 0, name)); 2148 sdp = ld_sym_enter(name, sym, hash, ifl, ofl, 0, SHN_UNDEF, 2149 0, 0, &where); 2150 sdp->sd_flags &= ~FLG_SY_CLEAN; 2151 sdp->sd_flags |= FLG_SY_CMDREF; 2152 2153 return (sdp); 2154 } 2155