1 /* x86 specific support for ELF 2 Copyright (C) 2017-2018 Free Software Foundation, Inc. 3 4 This file is part of BFD, the Binary File Descriptor library. 5 6 This program is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 3 of the License, or 9 (at your option) any later version. 10 11 This program is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 GNU General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with this program; if not, write to the Free Software 18 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, 19 MA 02110-1301, USA. */ 20 21 #include "elfxx-x86.h" 22 #include "elf-vxworks.h" 23 #include "objalloc.h" 24 #include "elf/i386.h" 25 #include "elf/x86-64.h" 26 27 /* The name of the dynamic interpreter. This is put in the .interp 28 section. */ 29 30 #define ELF32_DYNAMIC_INTERPRETER "/usr/lib/libc.so.1" 31 #define ELF64_DYNAMIC_INTERPRETER "/lib/ld64.so.1" 32 #define ELFX32_DYNAMIC_INTERPRETER "/lib/ldx32.so.1" 33 34 bfd_boolean 35 _bfd_x86_elf_mkobject (bfd *abfd) 36 { 37 return bfd_elf_allocate_object (abfd, 38 sizeof (struct elf_x86_obj_tdata), 39 get_elf_backend_data (abfd)->target_id); 40 } 41 42 /* _TLS_MODULE_BASE_ needs to be treated especially when linking 43 executables. Rather than setting it to the beginning of the TLS 44 section, we have to set it to the end. This function may be called 45 multiple times, it is idempotent. */ 46 47 void 48 _bfd_x86_elf_set_tls_module_base (struct bfd_link_info *info) 49 { 50 struct elf_x86_link_hash_table *htab; 51 struct bfd_link_hash_entry *base; 52 const struct elf_backend_data *bed; 53 54 if (!bfd_link_executable (info)) 55 return; 56 57 bed = get_elf_backend_data (info->output_bfd); 58 htab = elf_x86_hash_table (info, bed->target_id); 59 if (htab == NULL) 60 return; 61 62 base = htab->tls_module_base; 63 if (base == NULL) 64 return; 65 66 base->u.def.value = htab->elf.tls_size; 67 } 68 69 /* Return the base VMA address which should be subtracted from real addresses 70 when resolving @dtpoff relocation. 71 This is PT_TLS segment p_vaddr. */ 72 73 bfd_vma 74 _bfd_x86_elf_dtpoff_base (struct bfd_link_info *info) 75 { 76 /* If tls_sec is NULL, we should have signalled an error already. */ 77 if (elf_hash_table (info)->tls_sec == NULL) 78 return 0; 79 return elf_hash_table (info)->tls_sec->vma; 80 } 81 82 /* Allocate space in .plt, .got and associated reloc sections for 83 dynamic relocs. */ 84 85 static bfd_boolean 86 elf_x86_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf) 87 { 88 struct bfd_link_info *info; 89 struct elf_x86_link_hash_table *htab; 90 struct elf_x86_link_hash_entry *eh; 91 struct elf_dyn_relocs *p; 92 unsigned int plt_entry_size; 93 bfd_boolean resolved_to_zero; 94 const struct elf_backend_data *bed; 95 96 if (h->root.type == bfd_link_hash_indirect) 97 return TRUE; 98 99 eh = (struct elf_x86_link_hash_entry *) h; 100 101 info = (struct bfd_link_info *) inf; 102 bed = get_elf_backend_data (info->output_bfd); 103 htab = elf_x86_hash_table (info, bed->target_id); 104 if (htab == NULL) 105 return FALSE; 106 107 plt_entry_size = htab->plt.plt_entry_size; 108 109 resolved_to_zero = UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, eh); 110 111 /* We can't use the GOT PLT if pointer equality is needed since 112 finish_dynamic_symbol won't clear symbol value and the dynamic 113 linker won't update the GOT slot. We will get into an infinite 114 loop at run-time. */ 115 if (htab->plt_got != NULL 116 && h->type != STT_GNU_IFUNC 117 && !h->pointer_equality_needed 118 && h->plt.refcount > 0 119 && h->got.refcount > 0) 120 { 121 /* Don't use the regular PLT if there are both GOT and GOTPLT 122 reloctions. */ 123 h->plt.offset = (bfd_vma) -1; 124 125 /* Use the GOT PLT. */ 126 eh->plt_got.refcount = 1; 127 } 128 129 /* Since STT_GNU_IFUNC symbol must go through PLT, we handle it 130 here if it is defined and referenced in a non-shared object. */ 131 if (h->type == STT_GNU_IFUNC 132 && h->def_regular) 133 { 134 if (_bfd_elf_allocate_ifunc_dyn_relocs (info, h, &eh->dyn_relocs, 135 &htab->readonly_dynrelocs_against_ifunc, 136 plt_entry_size, 137 (htab->plt.has_plt0 138 * plt_entry_size), 139 htab->got_entry_size, 140 TRUE)) 141 { 142 asection *s = htab->plt_second; 143 if (h->plt.offset != (bfd_vma) -1 && s != NULL) 144 { 145 /* Use the second PLT section if it is created. */ 146 eh->plt_second.offset = s->size; 147 148 /* Make room for this entry in the second PLT section. */ 149 s->size += htab->non_lazy_plt->plt_entry_size; 150 } 151 152 return TRUE; 153 } 154 else 155 return FALSE; 156 } 157 /* Don't create the PLT entry if there are only function pointer 158 relocations which can be resolved at run-time. */ 159 else if (htab->elf.dynamic_sections_created 160 && (h->plt.refcount > 0 161 || eh->plt_got.refcount > 0)) 162 { 163 bfd_boolean use_plt_got = eh->plt_got.refcount > 0; 164 165 /* Make sure this symbol is output as a dynamic symbol. 166 Undefined weak syms won't yet be marked as dynamic. */ 167 if (h->dynindx == -1 168 && !h->forced_local 169 && !resolved_to_zero 170 && h->root.type == bfd_link_hash_undefweak) 171 { 172 if (! bfd_elf_link_record_dynamic_symbol (info, h)) 173 return FALSE; 174 } 175 176 if (bfd_link_pic (info) 177 || WILL_CALL_FINISH_DYNAMIC_SYMBOL (1, 0, h)) 178 { 179 asection *s = htab->elf.splt; 180 asection *second_s = htab->plt_second; 181 asection *got_s = htab->plt_got; 182 183 /* If this is the first .plt entry, make room for the special 184 first entry. The .plt section is used by prelink to undo 185 prelinking for dynamic relocations. */ 186 if (s->size == 0) 187 s->size = htab->plt.has_plt0 * plt_entry_size; 188 189 if (use_plt_got) 190 eh->plt_got.offset = got_s->size; 191 else 192 { 193 h->plt.offset = s->size; 194 if (second_s) 195 eh->plt_second.offset = second_s->size; 196 } 197 198 /* If this symbol is not defined in a regular file, and we are 199 not generating a shared library, then set the symbol to this 200 location in the .plt. This is required to make function 201 pointers compare as equal between the normal executable and 202 the shared library. */ 203 if (! bfd_link_pic (info) 204 && !h->def_regular) 205 { 206 if (use_plt_got) 207 { 208 /* We need to make a call to the entry of the GOT PLT 209 instead of regular PLT entry. */ 210 h->root.u.def.section = got_s; 211 h->root.u.def.value = eh->plt_got.offset; 212 } 213 else 214 { 215 if (second_s) 216 { 217 /* We need to make a call to the entry of the 218 second PLT instead of regular PLT entry. */ 219 h->root.u.def.section = second_s; 220 h->root.u.def.value = eh->plt_second.offset; 221 } 222 else 223 { 224 h->root.u.def.section = s; 225 h->root.u.def.value = h->plt.offset; 226 } 227 } 228 } 229 230 /* Make room for this entry. */ 231 if (use_plt_got) 232 got_s->size += htab->non_lazy_plt->plt_entry_size; 233 else 234 { 235 s->size += plt_entry_size; 236 if (second_s) 237 second_s->size += htab->non_lazy_plt->plt_entry_size; 238 239 /* We also need to make an entry in the .got.plt section, 240 which will be placed in the .got section by the linker 241 script. */ 242 htab->elf.sgotplt->size += htab->got_entry_size; 243 244 /* There should be no PLT relocation against resolved 245 undefined weak symbol in executable. */ 246 if (!resolved_to_zero) 247 { 248 /* We also need to make an entry in the .rel.plt 249 section. */ 250 htab->elf.srelplt->size += htab->sizeof_reloc; 251 htab->elf.srelplt->reloc_count++; 252 } 253 } 254 255 if (htab->target_os == is_vxworks && !bfd_link_pic (info)) 256 { 257 /* VxWorks has a second set of relocations for each PLT entry 258 in executables. They go in a separate relocation section, 259 which is processed by the kernel loader. */ 260 261 /* There are two relocations for the initial PLT entry: an 262 R_386_32 relocation for _GLOBAL_OFFSET_TABLE_ + 4 and an 263 R_386_32 relocation for _GLOBAL_OFFSET_TABLE_ + 8. */ 264 265 asection *srelplt2 = htab->srelplt2; 266 if (h->plt.offset == plt_entry_size) 267 srelplt2->size += (htab->sizeof_reloc * 2); 268 269 /* There are two extra relocations for each subsequent PLT entry: 270 an R_386_32 relocation for the GOT entry, and an R_386_32 271 relocation for the PLT entry. */ 272 273 srelplt2->size += (htab->sizeof_reloc * 2); 274 } 275 } 276 else 277 { 278 eh->plt_got.offset = (bfd_vma) -1; 279 h->plt.offset = (bfd_vma) -1; 280 h->needs_plt = 0; 281 } 282 } 283 else 284 { 285 eh->plt_got.offset = (bfd_vma) -1; 286 h->plt.offset = (bfd_vma) -1; 287 h->needs_plt = 0; 288 } 289 290 eh->tlsdesc_got = (bfd_vma) -1; 291 292 /* For i386, if R_386_TLS_{IE_32,IE,GOTIE} symbol is now local to the 293 binary, make it a R_386_TLS_LE_32 requiring no TLS entry. For 294 x86-64, if R_X86_64_GOTTPOFF symbol is now local to the binary, 295 make it a R_X86_64_TPOFF32 requiring no GOT entry. */ 296 if (h->got.refcount > 0 297 && bfd_link_executable (info) 298 && h->dynindx == -1 299 && (elf_x86_hash_entry (h)->tls_type & GOT_TLS_IE)) 300 h->got.offset = (bfd_vma) -1; 301 else if (h->got.refcount > 0) 302 { 303 asection *s; 304 bfd_boolean dyn; 305 int tls_type = elf_x86_hash_entry (h)->tls_type; 306 307 /* Make sure this symbol is output as a dynamic symbol. 308 Undefined weak syms won't yet be marked as dynamic. */ 309 if (h->dynindx == -1 310 && !h->forced_local 311 && !resolved_to_zero 312 && h->root.type == bfd_link_hash_undefweak) 313 { 314 if (! bfd_elf_link_record_dynamic_symbol (info, h)) 315 return FALSE; 316 } 317 318 s = htab->elf.sgot; 319 if (GOT_TLS_GDESC_P (tls_type)) 320 { 321 eh->tlsdesc_got = htab->elf.sgotplt->size 322 - elf_x86_compute_jump_table_size (htab); 323 htab->elf.sgotplt->size += 2 * htab->got_entry_size; 324 h->got.offset = (bfd_vma) -2; 325 } 326 if (! GOT_TLS_GDESC_P (tls_type) 327 || GOT_TLS_GD_P (tls_type)) 328 { 329 h->got.offset = s->size; 330 s->size += htab->got_entry_size; 331 /* R_386_TLS_GD and R_X86_64_TLSGD need 2 consecutive GOT 332 slots. */ 333 if (GOT_TLS_GD_P (tls_type) || tls_type == GOT_TLS_IE_BOTH) 334 s->size += htab->got_entry_size; 335 } 336 dyn = htab->elf.dynamic_sections_created; 337 /* R_386_TLS_IE_32 needs one dynamic relocation, 338 R_386_TLS_IE resp. R_386_TLS_GOTIE needs one dynamic relocation, 339 (but if both R_386_TLS_IE_32 and R_386_TLS_IE is present, we 340 need two), R_386_TLS_GD and R_X86_64_TLSGD need one if local 341 symbol and two if global. No dynamic relocation against 342 resolved undefined weak symbol in executable. */ 343 if (tls_type == GOT_TLS_IE_BOTH) 344 htab->elf.srelgot->size += 2 * htab->sizeof_reloc; 345 else if ((GOT_TLS_GD_P (tls_type) && h->dynindx == -1) 346 || (tls_type & GOT_TLS_IE)) 347 htab->elf.srelgot->size += htab->sizeof_reloc; 348 else if (GOT_TLS_GD_P (tls_type)) 349 htab->elf.srelgot->size += 2 * htab->sizeof_reloc; 350 else if (! GOT_TLS_GDESC_P (tls_type) 351 && ((ELF_ST_VISIBILITY (h->other) == STV_DEFAULT 352 && !resolved_to_zero) 353 || h->root.type != bfd_link_hash_undefweak) 354 && (bfd_link_pic (info) 355 || WILL_CALL_FINISH_DYNAMIC_SYMBOL (dyn, 0, h))) 356 htab->elf.srelgot->size += htab->sizeof_reloc; 357 if (GOT_TLS_GDESC_P (tls_type)) 358 { 359 htab->elf.srelplt->size += htab->sizeof_reloc; 360 if (bed->target_id == X86_64_ELF_DATA) 361 htab->tlsdesc_plt = (bfd_vma) -1; 362 } 363 } 364 else 365 h->got.offset = (bfd_vma) -1; 366 367 if (eh->dyn_relocs == NULL) 368 return TRUE; 369 370 /* In the shared -Bsymbolic case, discard space allocated for 371 dynamic pc-relative relocs against symbols which turn out to be 372 defined in regular objects. For the normal shared case, discard 373 space for pc-relative relocs that have become local due to symbol 374 visibility changes. */ 375 376 if (bfd_link_pic (info)) 377 { 378 /* Relocs that use pc_count are those that appear on a call 379 insn, or certain REL relocs that can generated via assembly. 380 We want calls to protected symbols to resolve directly to the 381 function rather than going via the plt. If people want 382 function pointer comparisons to work as expected then they 383 should avoid writing weird assembly. */ 384 if (SYMBOL_CALLS_LOCAL (info, h)) 385 { 386 struct elf_dyn_relocs **pp; 387 388 for (pp = &eh->dyn_relocs; (p = *pp) != NULL; ) 389 { 390 p->count -= p->pc_count; 391 p->pc_count = 0; 392 if (p->count == 0) 393 *pp = p->next; 394 else 395 pp = &p->next; 396 } 397 } 398 399 if (htab->target_os == is_vxworks) 400 { 401 struct elf_dyn_relocs **pp; 402 for (pp = &eh->dyn_relocs; (p = *pp) != NULL; ) 403 { 404 if (strcmp (p->sec->output_section->name, ".tls_vars") == 0) 405 *pp = p->next; 406 else 407 pp = &p->next; 408 } 409 } 410 411 /* Also discard relocs on undefined weak syms with non-default 412 visibility or in PIE. */ 413 if (eh->dyn_relocs != NULL) 414 { 415 if (h->root.type == bfd_link_hash_undefweak) 416 { 417 /* Undefined weak symbol is never bound locally in shared 418 library. */ 419 if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT 420 || resolved_to_zero) 421 { 422 if (bed->target_id == I386_ELF_DATA 423 && h->non_got_ref) 424 { 425 /* Keep dynamic non-GOT/non-PLT relocation so 426 that we can branch to 0 without PLT. */ 427 struct elf_dyn_relocs **pp; 428 429 for (pp = &eh->dyn_relocs; (p = *pp) != NULL; ) 430 if (p->pc_count == 0) 431 *pp = p->next; 432 else 433 { 434 /* Remove non-R_386_PC32 relocation. */ 435 p->count = p->pc_count; 436 pp = &p->next; 437 } 438 439 /* Make sure undefined weak symbols are output 440 as dynamic symbols in PIEs for dynamic non-GOT 441 non-PLT reloations. */ 442 if (eh->dyn_relocs != NULL 443 && !bfd_elf_link_record_dynamic_symbol (info, h)) 444 return FALSE; 445 } 446 else 447 eh->dyn_relocs = NULL; 448 } 449 else if (h->dynindx == -1 450 && !h->forced_local 451 && !bfd_elf_link_record_dynamic_symbol (info, h)) 452 return FALSE; 453 } 454 else if (bfd_link_executable (info) 455 && (h->needs_copy || eh->needs_copy) 456 && h->def_dynamic 457 && !h->def_regular) 458 { 459 /* NB: needs_copy is set only for x86-64. For PIE, 460 discard space for pc-relative relocs against symbols 461 which turn out to need copy relocs. */ 462 struct elf_dyn_relocs **pp; 463 464 for (pp = &eh->dyn_relocs; (p = *pp) != NULL; ) 465 { 466 if (p->pc_count != 0) 467 *pp = p->next; 468 else 469 pp = &p->next; 470 } 471 } 472 } 473 } 474 else if (ELIMINATE_COPY_RELOCS) 475 { 476 /* For the non-shared case, discard space for relocs against 477 symbols which turn out to need copy relocs or are not 478 dynamic. Keep dynamic relocations for run-time function 479 pointer initialization. */ 480 481 if ((!h->non_got_ref 482 || (h->root.type == bfd_link_hash_undefweak 483 && !resolved_to_zero)) 484 && ((h->def_dynamic 485 && !h->def_regular) 486 || (htab->elf.dynamic_sections_created 487 && (h->root.type == bfd_link_hash_undefweak 488 || h->root.type == bfd_link_hash_undefined)))) 489 { 490 /* Make sure this symbol is output as a dynamic symbol. 491 Undefined weak syms won't yet be marked as dynamic. */ 492 if (h->dynindx == -1 493 && !h->forced_local 494 && !resolved_to_zero 495 && h->root.type == bfd_link_hash_undefweak 496 && ! bfd_elf_link_record_dynamic_symbol (info, h)) 497 return FALSE; 498 499 /* If that succeeded, we know we'll be keeping all the 500 relocs. */ 501 if (h->dynindx != -1) 502 goto keep; 503 } 504 505 eh->dyn_relocs = NULL; 506 507 keep: ; 508 } 509 510 /* Finally, allocate space. */ 511 for (p = eh->dyn_relocs; p != NULL; p = p->next) 512 { 513 asection *sreloc; 514 515 sreloc = elf_section_data (p->sec)->sreloc; 516 517 BFD_ASSERT (sreloc != NULL); 518 sreloc->size += p->count * htab->sizeof_reloc; 519 } 520 521 return TRUE; 522 } 523 524 /* Find dynamic relocs for H that apply to read-only sections. */ 525 526 static asection * 527 readonly_dynrelocs (struct elf_link_hash_entry *h) 528 { 529 struct elf_dyn_relocs *p; 530 531 for (p = elf_x86_hash_entry (h)->dyn_relocs; p != NULL; p = p->next) 532 { 533 asection *s = p->sec->output_section; 534 535 if (s != NULL && (s->flags & SEC_READONLY) != 0) 536 return p->sec; 537 } 538 return NULL; 539 } 540 541 /* Set DF_TEXTREL if we find any dynamic relocs that apply to 542 read-only sections. */ 543 544 static bfd_boolean 545 maybe_set_textrel (struct elf_link_hash_entry *h, void *inf) 546 { 547 asection *sec; 548 549 if (h->root.type == bfd_link_hash_indirect) 550 return TRUE; 551 552 /* Skip local IFUNC symbols. */ 553 if (h->forced_local && h->type == STT_GNU_IFUNC) 554 return TRUE; 555 556 sec = readonly_dynrelocs (h); 557 if (sec != NULL) 558 { 559 struct bfd_link_info *info = (struct bfd_link_info *) inf; 560 561 info->flags |= DF_TEXTREL; 562 /* xgettext:c-format */ 563 info->callbacks->minfo (_("%B: dynamic relocation against `%T' " 564 "in read-only section `%A'\n"), 565 sec->owner, h->root.root.string, sec); 566 567 if ((info->warn_shared_textrel && bfd_link_pic (info)) 568 || info->error_textrel) 569 /* xgettext:c-format */ 570 info->callbacks->einfo (_("%P: %B: warning: relocation against `%s' " 571 "in read-only section `%A'\n"), 572 sec->owner, h->root.root.string, sec); 573 574 /* Not an error, just cut short the traversal. */ 575 return FALSE; 576 } 577 return TRUE; 578 } 579 580 /* Allocate space in .plt, .got and associated reloc sections for 581 local dynamic relocs. */ 582 583 static bfd_boolean 584 elf_x86_allocate_local_dynreloc (void **slot, void *inf) 585 { 586 struct elf_link_hash_entry *h 587 = (struct elf_link_hash_entry *) *slot; 588 589 if (h->type != STT_GNU_IFUNC 590 || !h->def_regular 591 || !h->ref_regular 592 || !h->forced_local 593 || h->root.type != bfd_link_hash_defined) 594 abort (); 595 596 return elf_x86_allocate_dynrelocs (h, inf); 597 } 598 599 /* Find and/or create a hash entry for local symbol. */ 600 601 struct elf_link_hash_entry * 602 _bfd_elf_x86_get_local_sym_hash (struct elf_x86_link_hash_table *htab, 603 bfd *abfd, const Elf_Internal_Rela *rel, 604 bfd_boolean create) 605 { 606 struct elf_x86_link_hash_entry e, *ret; 607 asection *sec = abfd->sections; 608 hashval_t h = ELF_LOCAL_SYMBOL_HASH (sec->id, 609 htab->r_sym (rel->r_info)); 610 void **slot; 611 612 e.elf.indx = sec->id; 613 e.elf.dynstr_index = htab->r_sym (rel->r_info); 614 slot = htab_find_slot_with_hash (htab->loc_hash_table, &e, h, 615 create ? INSERT : NO_INSERT); 616 617 if (!slot) 618 return NULL; 619 620 if (*slot) 621 { 622 ret = (struct elf_x86_link_hash_entry *) *slot; 623 return &ret->elf; 624 } 625 626 ret = (struct elf_x86_link_hash_entry *) 627 objalloc_alloc ((struct objalloc *) htab->loc_hash_memory, 628 sizeof (struct elf_x86_link_hash_entry)); 629 if (ret) 630 { 631 memset (ret, 0, sizeof (*ret)); 632 ret->elf.indx = sec->id; 633 ret->elf.dynstr_index = htab->r_sym (rel->r_info); 634 ret->elf.dynindx = -1; 635 ret->plt_got.offset = (bfd_vma) -1; 636 *slot = ret; 637 } 638 return &ret->elf; 639 } 640 641 /* Create an entry in a x86 ELF linker hash table. NB: THIS MUST BE IN 642 SYNC WITH _bfd_elf_link_hash_newfunc. */ 643 644 struct bfd_hash_entry * 645 _bfd_x86_elf_link_hash_newfunc (struct bfd_hash_entry *entry, 646 struct bfd_hash_table *table, 647 const char *string) 648 { 649 /* Allocate the structure if it has not already been allocated by a 650 subclass. */ 651 if (entry == NULL) 652 { 653 entry = (struct bfd_hash_entry *) 654 bfd_hash_allocate (table, 655 sizeof (struct elf_x86_link_hash_entry)); 656 if (entry == NULL) 657 return entry; 658 } 659 660 /* Call the allocation method of the superclass. */ 661 entry = _bfd_link_hash_newfunc (entry, table, string); 662 if (entry != NULL) 663 { 664 struct elf_x86_link_hash_entry *eh 665 = (struct elf_x86_link_hash_entry *) entry; 666 struct elf_link_hash_table *htab 667 = (struct elf_link_hash_table *) table; 668 669 memset (&eh->elf.size, 0, 670 (sizeof (struct elf_x86_link_hash_entry) 671 - offsetof (struct elf_link_hash_entry, size))); 672 /* Set local fields. */ 673 eh->elf.indx = -1; 674 eh->elf.dynindx = -1; 675 eh->elf.got = htab->init_got_refcount; 676 eh->elf.plt = htab->init_plt_refcount; 677 /* Assume that we have been called by a non-ELF symbol reader. 678 This flag is then reset by the code which reads an ELF input 679 file. This ensures that a symbol created by a non-ELF symbol 680 reader will have the flag set correctly. */ 681 eh->elf.non_elf = 1; 682 eh->plt_second.offset = (bfd_vma) -1; 683 eh->plt_got.offset = (bfd_vma) -1; 684 eh->tlsdesc_got = (bfd_vma) -1; 685 eh->zero_undefweak = 1; 686 } 687 688 return entry; 689 } 690 691 /* Compute a hash of a local hash entry. We use elf_link_hash_entry 692 for local symbol so that we can handle local STT_GNU_IFUNC symbols 693 as global symbol. We reuse indx and dynstr_index for local symbol 694 hash since they aren't used by global symbols in this backend. */ 695 696 hashval_t 697 _bfd_x86_elf_local_htab_hash (const void *ptr) 698 { 699 struct elf_link_hash_entry *h 700 = (struct elf_link_hash_entry *) ptr; 701 return ELF_LOCAL_SYMBOL_HASH (h->indx, h->dynstr_index); 702 } 703 704 /* Compare local hash entries. */ 705 706 int 707 _bfd_x86_elf_local_htab_eq (const void *ptr1, const void *ptr2) 708 { 709 struct elf_link_hash_entry *h1 710 = (struct elf_link_hash_entry *) ptr1; 711 struct elf_link_hash_entry *h2 712 = (struct elf_link_hash_entry *) ptr2; 713 714 return h1->indx == h2->indx && h1->dynstr_index == h2->dynstr_index; 715 } 716 717 /* Destroy an x86 ELF linker hash table. */ 718 719 static void 720 elf_x86_link_hash_table_free (bfd *obfd) 721 { 722 struct elf_x86_link_hash_table *htab 723 = (struct elf_x86_link_hash_table *) obfd->link.hash; 724 725 if (htab->loc_hash_table) 726 htab_delete (htab->loc_hash_table); 727 if (htab->loc_hash_memory) 728 objalloc_free ((struct objalloc *) htab->loc_hash_memory); 729 _bfd_elf_link_hash_table_free (obfd); 730 } 731 732 static bfd_boolean 733 elf_i386_is_reloc_section (const char *secname) 734 { 735 return CONST_STRNEQ (secname, ".rel"); 736 } 737 738 static bfd_boolean 739 elf_x86_64_is_reloc_section (const char *secname) 740 { 741 return CONST_STRNEQ (secname, ".rela"); 742 } 743 744 /* Create an x86 ELF linker hash table. */ 745 746 struct bfd_link_hash_table * 747 _bfd_x86_elf_link_hash_table_create (bfd *abfd) 748 { 749 struct elf_x86_link_hash_table *ret; 750 const struct elf_backend_data *bed; 751 bfd_size_type amt = sizeof (struct elf_x86_link_hash_table); 752 753 ret = (struct elf_x86_link_hash_table *) bfd_zmalloc (amt); 754 if (ret == NULL) 755 return NULL; 756 757 bed = get_elf_backend_data (abfd); 758 if (!_bfd_elf_link_hash_table_init (&ret->elf, abfd, 759 _bfd_x86_elf_link_hash_newfunc, 760 sizeof (struct elf_x86_link_hash_entry), 761 bed->target_id)) 762 { 763 free (ret); 764 return NULL; 765 } 766 767 if (bed->target_id == X86_64_ELF_DATA) 768 { 769 ret->is_reloc_section = elf_x86_64_is_reloc_section; 770 ret->dt_reloc = DT_RELA; 771 ret->dt_reloc_sz = DT_RELASZ; 772 ret->dt_reloc_ent = DT_RELAENT; 773 ret->got_entry_size = 8; 774 ret->tls_get_addr = "__tls_get_addr"; 775 } 776 if (ABI_64_P (abfd)) 777 { 778 ret->sizeof_reloc = sizeof (Elf64_External_Rela); 779 ret->pointer_r_type = R_X86_64_64; 780 ret->dynamic_interpreter = ELF64_DYNAMIC_INTERPRETER; 781 ret->dynamic_interpreter_size = sizeof ELF64_DYNAMIC_INTERPRETER; 782 } 783 else 784 { 785 if (bed->target_id == X86_64_ELF_DATA) 786 { 787 ret->sizeof_reloc = sizeof (Elf32_External_Rela); 788 ret->pointer_r_type = R_X86_64_32; 789 ret->dynamic_interpreter = ELFX32_DYNAMIC_INTERPRETER; 790 ret->dynamic_interpreter_size 791 = sizeof ELFX32_DYNAMIC_INTERPRETER; 792 } 793 else 794 { 795 ret->is_reloc_section = elf_i386_is_reloc_section; 796 ret->dt_reloc = DT_REL; 797 ret->dt_reloc_sz = DT_RELSZ; 798 ret->dt_reloc_ent = DT_RELENT; 799 ret->sizeof_reloc = sizeof (Elf32_External_Rel); 800 ret->got_entry_size = 4; 801 ret->pointer_r_type = R_386_32; 802 ret->dynamic_interpreter = ELF32_DYNAMIC_INTERPRETER; 803 ret->dynamic_interpreter_size 804 = sizeof ELF32_DYNAMIC_INTERPRETER; 805 ret->tls_get_addr = "___tls_get_addr"; 806 } 807 } 808 ret->target_id = bed->target_id; 809 ret->target_os = get_elf_x86_backend_data (abfd)->target_os; 810 811 ret->loc_hash_table = htab_try_create (1024, 812 _bfd_x86_elf_local_htab_hash, 813 _bfd_x86_elf_local_htab_eq, 814 NULL); 815 ret->loc_hash_memory = objalloc_create (); 816 if (!ret->loc_hash_table || !ret->loc_hash_memory) 817 { 818 elf_x86_link_hash_table_free (abfd); 819 return NULL; 820 } 821 ret->elf.root.hash_table_free = elf_x86_link_hash_table_free; 822 823 return &ret->elf.root; 824 } 825 826 /* Sort relocs into address order. */ 827 828 int 829 _bfd_x86_elf_compare_relocs (const void *ap, const void *bp) 830 { 831 const arelent *a = * (const arelent **) ap; 832 const arelent *b = * (const arelent **) bp; 833 834 if (a->address > b->address) 835 return 1; 836 else if (a->address < b->address) 837 return -1; 838 else 839 return 0; 840 } 841 842 bfd_boolean 843 _bfd_x86_elf_link_check_relocs (bfd *abfd, struct bfd_link_info *info) 844 { 845 if (!bfd_link_relocatable (info)) 846 { 847 /* Check for __tls_get_addr reference. */ 848 struct elf_x86_link_hash_table *htab; 849 const struct elf_backend_data *bed = get_elf_backend_data (abfd); 850 htab = elf_x86_hash_table (info, bed->target_id); 851 if (htab) 852 { 853 struct elf_link_hash_entry *h; 854 855 h = elf_link_hash_lookup (elf_hash_table (info), 856 htab->tls_get_addr, 857 FALSE, FALSE, FALSE); 858 if (h != NULL) 859 { 860 elf_x86_hash_entry (h)->tls_get_addr = 1; 861 862 /* Check the versioned __tls_get_addr symbol. */ 863 while (h->root.type == bfd_link_hash_indirect) 864 { 865 h = (struct elf_link_hash_entry *) h->root.u.i.link; 866 elf_x86_hash_entry (h)->tls_get_addr = 1; 867 } 868 } 869 870 /* "__ehdr_start" will be defined by linker as a hidden symbol 871 later if it is referenced and not defined. */ 872 h = elf_link_hash_lookup (elf_hash_table (info), 873 "__ehdr_start", 874 FALSE, FALSE, FALSE); 875 if (h != NULL 876 && (h->root.type == bfd_link_hash_new 877 || h->root.type == bfd_link_hash_undefined 878 || h->root.type == bfd_link_hash_undefweak 879 || h->root.type == bfd_link_hash_common)) 880 { 881 elf_x86_hash_entry (h)->local_ref = 2; 882 elf_x86_hash_entry (h)->linker_def = 1; 883 } 884 } 885 } 886 887 /* Invoke the regular ELF backend linker to do all the work. */ 888 return _bfd_elf_link_check_relocs (abfd, info); 889 } 890 891 /* Set the sizes of the dynamic sections. */ 892 893 bfd_boolean 894 _bfd_x86_elf_size_dynamic_sections (bfd *output_bfd, 895 struct bfd_link_info *info) 896 { 897 struct elf_x86_link_hash_table *htab; 898 bfd *dynobj; 899 asection *s; 900 bfd_boolean relocs; 901 bfd *ibfd; 902 const struct elf_backend_data *bed 903 = get_elf_backend_data (output_bfd); 904 905 htab = elf_x86_hash_table (info, bed->target_id); 906 if (htab == NULL) 907 return FALSE; 908 dynobj = htab->elf.dynobj; 909 if (dynobj == NULL) 910 abort (); 911 912 /* Set up .got offsets for local syms, and space for local dynamic 913 relocs. */ 914 for (ibfd = info->input_bfds; ibfd != NULL; ibfd = ibfd->link.next) 915 { 916 bfd_signed_vma *local_got; 917 bfd_signed_vma *end_local_got; 918 char *local_tls_type; 919 bfd_vma *local_tlsdesc_gotent; 920 bfd_size_type locsymcount; 921 Elf_Internal_Shdr *symtab_hdr; 922 asection *srel; 923 924 if (! is_x86_elf (ibfd, htab)) 925 continue; 926 927 for (s = ibfd->sections; s != NULL; s = s->next) 928 { 929 struct elf_dyn_relocs *p; 930 931 for (p = ((struct elf_dyn_relocs *) 932 elf_section_data (s)->local_dynrel); 933 p != NULL; 934 p = p->next) 935 { 936 if (!bfd_is_abs_section (p->sec) 937 && bfd_is_abs_section (p->sec->output_section)) 938 { 939 /* Input section has been discarded, either because 940 it is a copy of a linkonce section or due to 941 linker script /DISCARD/, so we'll be discarding 942 the relocs too. */ 943 } 944 else if (htab->target_os == is_vxworks 945 && strcmp (p->sec->output_section->name, 946 ".tls_vars") == 0) 947 { 948 /* Relocations in vxworks .tls_vars sections are 949 handled specially by the loader. */ 950 } 951 else if (p->count != 0) 952 { 953 srel = elf_section_data (p->sec)->sreloc; 954 srel->size += p->count * htab->sizeof_reloc; 955 if ((p->sec->output_section->flags & SEC_READONLY) != 0 956 && (info->flags & DF_TEXTREL) == 0) 957 { 958 info->flags |= DF_TEXTREL; 959 if ((info->warn_shared_textrel && bfd_link_pic (info)) 960 || info->error_textrel) 961 /* xgettext:c-format */ 962 info->callbacks->einfo 963 (_("%P: %B: warning: relocation " 964 "in read-only section `%A'\n"), 965 p->sec->owner, p->sec); 966 } 967 } 968 } 969 } 970 971 local_got = elf_local_got_refcounts (ibfd); 972 if (!local_got) 973 continue; 974 975 symtab_hdr = &elf_symtab_hdr (ibfd); 976 locsymcount = symtab_hdr->sh_info; 977 end_local_got = local_got + locsymcount; 978 local_tls_type = elf_x86_local_got_tls_type (ibfd); 979 local_tlsdesc_gotent = elf_x86_local_tlsdesc_gotent (ibfd); 980 s = htab->elf.sgot; 981 srel = htab->elf.srelgot; 982 for (; local_got < end_local_got; 983 ++local_got, ++local_tls_type, ++local_tlsdesc_gotent) 984 { 985 *local_tlsdesc_gotent = (bfd_vma) -1; 986 if (*local_got > 0) 987 { 988 if (GOT_TLS_GDESC_P (*local_tls_type)) 989 { 990 *local_tlsdesc_gotent = htab->elf.sgotplt->size 991 - elf_x86_compute_jump_table_size (htab); 992 htab->elf.sgotplt->size += 2 * htab->got_entry_size; 993 *local_got = (bfd_vma) -2; 994 } 995 if (! GOT_TLS_GDESC_P (*local_tls_type) 996 || GOT_TLS_GD_P (*local_tls_type)) 997 { 998 *local_got = s->size; 999 s->size += htab->got_entry_size; 1000 if (GOT_TLS_GD_P (*local_tls_type) 1001 || *local_tls_type == GOT_TLS_IE_BOTH) 1002 s->size += htab->got_entry_size; 1003 } 1004 if (bfd_link_pic (info) 1005 || GOT_TLS_GD_ANY_P (*local_tls_type) 1006 || (*local_tls_type & GOT_TLS_IE)) 1007 { 1008 if (*local_tls_type == GOT_TLS_IE_BOTH) 1009 srel->size += 2 * htab->sizeof_reloc; 1010 else if (GOT_TLS_GD_P (*local_tls_type) 1011 || ! GOT_TLS_GDESC_P (*local_tls_type)) 1012 srel->size += htab->sizeof_reloc; 1013 if (GOT_TLS_GDESC_P (*local_tls_type)) 1014 { 1015 htab->elf.srelplt->size += htab->sizeof_reloc; 1016 if (bed->target_id == X86_64_ELF_DATA) 1017 htab->tlsdesc_plt = (bfd_vma) -1; 1018 } 1019 } 1020 } 1021 else 1022 *local_got = (bfd_vma) -1; 1023 } 1024 } 1025 1026 if (htab->tls_ld_or_ldm_got.refcount > 0) 1027 { 1028 /* Allocate 2 got entries and 1 dynamic reloc for R_386_TLS_LDM 1029 or R_X86_64_TLSLD relocs. */ 1030 htab->tls_ld_or_ldm_got.offset = htab->elf.sgot->size; 1031 htab->elf.sgot->size += 2 * htab->got_entry_size; 1032 htab->elf.srelgot->size += htab->sizeof_reloc; 1033 } 1034 else 1035 htab->tls_ld_or_ldm_got.offset = -1; 1036 1037 /* Allocate global sym .plt and .got entries, and space for global 1038 sym dynamic relocs. */ 1039 elf_link_hash_traverse (&htab->elf, elf_x86_allocate_dynrelocs, 1040 info); 1041 1042 /* Allocate .plt and .got entries, and space for local symbols. */ 1043 htab_traverse (htab->loc_hash_table, elf_x86_allocate_local_dynreloc, 1044 info); 1045 1046 /* For every jump slot reserved in the sgotplt, reloc_count is 1047 incremented. However, when we reserve space for TLS descriptors, 1048 it's not incremented, so in order to compute the space reserved 1049 for them, it suffices to multiply the reloc count by the jump 1050 slot size. 1051 1052 PR ld/13302: We start next_irelative_index at the end of .rela.plt 1053 so that R_{386,X86_64}_IRELATIVE entries come last. */ 1054 if (htab->elf.srelplt) 1055 { 1056 htab->next_tls_desc_index = htab->elf.srelplt->reloc_count; 1057 htab->sgotplt_jump_table_size 1058 = elf_x86_compute_jump_table_size (htab); 1059 htab->next_irelative_index = htab->elf.srelplt->reloc_count - 1; 1060 } 1061 else if (htab->elf.irelplt) 1062 htab->next_irelative_index = htab->elf.irelplt->reloc_count - 1; 1063 1064 if (htab->tlsdesc_plt) 1065 { 1066 /* NB: tlsdesc_plt is set only for x86-64. If we're not using 1067 lazy TLS relocations, don't generate the PLT and GOT entries 1068 they require. */ 1069 if ((info->flags & DF_BIND_NOW)) 1070 htab->tlsdesc_plt = 0; 1071 else 1072 { 1073 htab->tlsdesc_got = htab->elf.sgot->size; 1074 htab->elf.sgot->size += htab->got_entry_size; 1075 /* Reserve room for the initial entry. 1076 FIXME: we could probably do away with it in this case. */ 1077 if (htab->elf.splt->size == 0) 1078 htab->elf.splt->size = htab->plt.plt_entry_size; 1079 htab->tlsdesc_plt = htab->elf.splt->size; 1080 htab->elf.splt->size += htab->plt.plt_entry_size; 1081 } 1082 } 1083 1084 if (htab->elf.sgotplt) 1085 { 1086 /* Don't allocate .got.plt section if there are no GOT nor PLT 1087 entries and there is no reference to _GLOBAL_OFFSET_TABLE_. */ 1088 if ((htab->elf.hgot == NULL 1089 || !htab->elf.hgot->ref_regular_nonweak) 1090 && (htab->elf.sgotplt->size == bed->got_header_size) 1091 && (htab->elf.splt == NULL 1092 || htab->elf.splt->size == 0) 1093 && (htab->elf.sgot == NULL 1094 || htab->elf.sgot->size == 0) 1095 && (htab->elf.iplt == NULL 1096 || htab->elf.iplt->size == 0) 1097 && (htab->elf.igotplt == NULL 1098 || htab->elf.igotplt->size == 0)) 1099 htab->elf.sgotplt->size = 0; 1100 } 1101 1102 if (_bfd_elf_eh_frame_present (info)) 1103 { 1104 if (htab->plt_eh_frame != NULL 1105 && htab->elf.splt != NULL 1106 && htab->elf.splt->size != 0 1107 && !bfd_is_abs_section (htab->elf.splt->output_section)) 1108 htab->plt_eh_frame->size = htab->plt.eh_frame_plt_size; 1109 1110 if (htab->plt_got_eh_frame != NULL 1111 && htab->plt_got != NULL 1112 && htab->plt_got->size != 0 1113 && !bfd_is_abs_section (htab->plt_got->output_section)) 1114 htab->plt_got_eh_frame->size 1115 = htab->non_lazy_plt->eh_frame_plt_size; 1116 1117 /* Unwind info for the second PLT and .plt.got sections are 1118 identical. */ 1119 if (htab->plt_second_eh_frame != NULL 1120 && htab->plt_second != NULL 1121 && htab->plt_second->size != 0 1122 && !bfd_is_abs_section (htab->plt_second->output_section)) 1123 htab->plt_second_eh_frame->size 1124 = htab->non_lazy_plt->eh_frame_plt_size; 1125 } 1126 1127 /* We now have determined the sizes of the various dynamic sections. 1128 Allocate memory for them. */ 1129 relocs = FALSE; 1130 for (s = dynobj->sections; s != NULL; s = s->next) 1131 { 1132 bfd_boolean strip_section = TRUE; 1133 1134 if ((s->flags & SEC_LINKER_CREATED) == 0) 1135 continue; 1136 1137 if (s == htab->elf.splt 1138 || s == htab->elf.sgot) 1139 { 1140 /* Strip this section if we don't need it; see the 1141 comment below. */ 1142 /* We'd like to strip these sections if they aren't needed, but if 1143 we've exported dynamic symbols from them we must leave them. 1144 It's too late to tell BFD to get rid of the symbols. */ 1145 1146 if (htab->elf.hplt != NULL) 1147 strip_section = FALSE; 1148 } 1149 else if (s == htab->elf.sgotplt 1150 || s == htab->elf.iplt 1151 || s == htab->elf.igotplt 1152 || s == htab->plt_second 1153 || s == htab->plt_got 1154 || s == htab->plt_eh_frame 1155 || s == htab->plt_got_eh_frame 1156 || s == htab->plt_second_eh_frame 1157 || s == htab->elf.sdynbss 1158 || s == htab->elf.sdynrelro) 1159 { 1160 /* Strip these too. */ 1161 } 1162 else if (htab->is_reloc_section (bfd_get_section_name (dynobj, s))) 1163 { 1164 if (s->size != 0 1165 && s != htab->elf.srelplt 1166 && s != htab->srelplt2) 1167 relocs = TRUE; 1168 1169 /* We use the reloc_count field as a counter if we need 1170 to copy relocs into the output file. */ 1171 if (s != htab->elf.srelplt) 1172 s->reloc_count = 0; 1173 } 1174 else 1175 { 1176 /* It's not one of our sections, so don't allocate space. */ 1177 continue; 1178 } 1179 1180 if (s->size == 0) 1181 { 1182 /* If we don't need this section, strip it from the 1183 output file. This is mostly to handle .rel.bss and 1184 .rel.plt. We must create both sections in 1185 create_dynamic_sections, because they must be created 1186 before the linker maps input sections to output 1187 sections. The linker does that before 1188 adjust_dynamic_symbol is called, and it is that 1189 function which decides whether anything needs to go 1190 into these sections. */ 1191 if (strip_section) 1192 s->flags |= SEC_EXCLUDE; 1193 continue; 1194 } 1195 1196 if ((s->flags & SEC_HAS_CONTENTS) == 0) 1197 continue; 1198 1199 /* Allocate memory for the section contents. We use bfd_zalloc 1200 here in case unused entries are not reclaimed before the 1201 section's contents are written out. This should not happen, 1202 but this way if it does, we get a R_386_NONE or R_X86_64_NONE 1203 reloc instead of garbage. */ 1204 s->contents = (unsigned char *) bfd_zalloc (dynobj, s->size); 1205 if (s->contents == NULL) 1206 return FALSE; 1207 } 1208 1209 if (htab->plt_eh_frame != NULL 1210 && htab->plt_eh_frame->contents != NULL) 1211 { 1212 memcpy (htab->plt_eh_frame->contents, 1213 htab->plt.eh_frame_plt, 1214 htab->plt_eh_frame->size); 1215 bfd_put_32 (dynobj, htab->elf.splt->size, 1216 htab->plt_eh_frame->contents + PLT_FDE_LEN_OFFSET); 1217 } 1218 1219 if (htab->plt_got_eh_frame != NULL 1220 && htab->plt_got_eh_frame->contents != NULL) 1221 { 1222 memcpy (htab->plt_got_eh_frame->contents, 1223 htab->non_lazy_plt->eh_frame_plt, 1224 htab->plt_got_eh_frame->size); 1225 bfd_put_32 (dynobj, htab->plt_got->size, 1226 (htab->plt_got_eh_frame->contents 1227 + PLT_FDE_LEN_OFFSET)); 1228 } 1229 1230 if (htab->plt_second_eh_frame != NULL 1231 && htab->plt_second_eh_frame->contents != NULL) 1232 { 1233 memcpy (htab->plt_second_eh_frame->contents, 1234 htab->non_lazy_plt->eh_frame_plt, 1235 htab->plt_second_eh_frame->size); 1236 bfd_put_32 (dynobj, htab->plt_second->size, 1237 (htab->plt_second_eh_frame->contents 1238 + PLT_FDE_LEN_OFFSET)); 1239 } 1240 1241 if (htab->elf.dynamic_sections_created) 1242 { 1243 /* Add some entries to the .dynamic section. We fill in the 1244 values later, in elf_{i386,x86_64}_finish_dynamic_sections, 1245 but we must add the entries now so that we get the correct 1246 size for the .dynamic section. The DT_DEBUG entry is filled 1247 in by the dynamic linker and used by the debugger. */ 1248 #define add_dynamic_entry(TAG, VAL) \ 1249 _bfd_elf_add_dynamic_entry (info, TAG, VAL) 1250 1251 if (bfd_link_executable (info)) 1252 { 1253 if (!add_dynamic_entry (DT_DEBUG, 0)) 1254 return FALSE; 1255 } 1256 1257 if (htab->elf.splt->size != 0) 1258 { 1259 /* DT_PLTGOT is used by prelink even if there is no PLT 1260 relocation. */ 1261 if (!add_dynamic_entry (DT_PLTGOT, 0)) 1262 return FALSE; 1263 } 1264 1265 if (htab->elf.srelplt->size != 0) 1266 { 1267 if (!add_dynamic_entry (DT_PLTRELSZ, 0) 1268 || !add_dynamic_entry (DT_PLTREL, htab->dt_reloc) 1269 || !add_dynamic_entry (DT_JMPREL, 0)) 1270 return FALSE; 1271 } 1272 1273 if (htab->tlsdesc_plt 1274 && (!add_dynamic_entry (DT_TLSDESC_PLT, 0) 1275 || !add_dynamic_entry (DT_TLSDESC_GOT, 0))) 1276 return FALSE; 1277 1278 if (relocs) 1279 { 1280 if (!add_dynamic_entry (htab->dt_reloc, 0) 1281 || !add_dynamic_entry (htab->dt_reloc_sz, 0) 1282 || !add_dynamic_entry (htab->dt_reloc_ent, 1283 htab->sizeof_reloc)) 1284 return FALSE; 1285 1286 /* If any dynamic relocs apply to a read-only section, 1287 then we need a DT_TEXTREL entry. */ 1288 if ((info->flags & DF_TEXTREL) == 0) 1289 elf_link_hash_traverse (&htab->elf, maybe_set_textrel, info); 1290 1291 if ((info->flags & DF_TEXTREL) != 0) 1292 { 1293 if (htab->readonly_dynrelocs_against_ifunc) 1294 { 1295 info->callbacks->einfo 1296 (_("%P%X: read-only segment has dynamic IFUNC relocations;" 1297 " recompile with -fPIC\n")); 1298 bfd_set_error (bfd_error_bad_value); 1299 return FALSE; 1300 } 1301 1302 if (!add_dynamic_entry (DT_TEXTREL, 0)) 1303 return FALSE; 1304 } 1305 } 1306 if (htab->target_os == is_vxworks 1307 && !elf_vxworks_add_dynamic_entries (output_bfd, info)) 1308 return FALSE; 1309 } 1310 #undef add_dynamic_entry 1311 1312 return TRUE; 1313 } 1314 1315 /* Finish up the x86 dynamic sections. */ 1316 1317 struct elf_x86_link_hash_table * 1318 _bfd_x86_elf_finish_dynamic_sections (bfd *output_bfd, 1319 struct bfd_link_info *info) 1320 { 1321 struct elf_x86_link_hash_table *htab; 1322 const struct elf_backend_data *bed; 1323 bfd *dynobj; 1324 asection *sdyn; 1325 bfd_byte *dyncon, *dynconend; 1326 bfd_size_type sizeof_dyn; 1327 1328 bed = get_elf_backend_data (output_bfd); 1329 htab = elf_x86_hash_table (info, bed->target_id); 1330 if (htab == NULL) 1331 return htab; 1332 1333 dynobj = htab->elf.dynobj; 1334 sdyn = bfd_get_linker_section (dynobj, ".dynamic"); 1335 1336 /* GOT is always created in setup_gnu_properties. But it may not be 1337 needed. .got.plt section may be needed for static IFUNC. */ 1338 if (htab->elf.sgotplt && htab->elf.sgotplt->size > 0) 1339 { 1340 bfd_vma dynamic_addr; 1341 1342 if (bfd_is_abs_section (htab->elf.sgotplt->output_section)) 1343 { 1344 _bfd_error_handler 1345 (_("discarded output section: `%A'"), htab->elf.sgotplt); 1346 return NULL; 1347 } 1348 1349 elf_section_data (htab->elf.sgotplt->output_section)->this_hdr.sh_entsize 1350 = htab->got_entry_size; 1351 1352 dynamic_addr = (sdyn == NULL 1353 ? (bfd_vma) 0 1354 : sdyn->output_section->vma + sdyn->output_offset); 1355 1356 /* Set the first entry in the global offset table to the address 1357 of the dynamic section. Write GOT[1] and GOT[2], needed for 1358 the dynamic linker. */ 1359 if (htab->got_entry_size == 8) 1360 { 1361 bfd_put_64 (output_bfd, dynamic_addr, 1362 htab->elf.sgotplt->contents); 1363 bfd_put_64 (output_bfd, (bfd_vma) 0, 1364 htab->elf.sgotplt->contents + 8); 1365 bfd_put_64 (output_bfd, (bfd_vma) 0, 1366 htab->elf.sgotplt->contents + 8*2); 1367 } 1368 else 1369 { 1370 bfd_put_32 (output_bfd, dynamic_addr, 1371 htab->elf.sgotplt->contents); 1372 bfd_put_32 (output_bfd, 0, 1373 htab->elf.sgotplt->contents + 4); 1374 bfd_put_32 (output_bfd, 0, 1375 htab->elf.sgotplt->contents + 4*2); 1376 } 1377 } 1378 1379 if (!htab->elf.dynamic_sections_created) 1380 return htab; 1381 1382 if (sdyn == NULL || htab->elf.sgot == NULL) 1383 abort (); 1384 1385 sizeof_dyn = bed->s->sizeof_dyn; 1386 dyncon = sdyn->contents; 1387 dynconend = sdyn->contents + sdyn->size; 1388 for (; dyncon < dynconend; dyncon += sizeof_dyn) 1389 { 1390 Elf_Internal_Dyn dyn; 1391 asection *s; 1392 1393 (*bed->s->swap_dyn_in) (dynobj, dyncon, &dyn); 1394 1395 switch (dyn.d_tag) 1396 { 1397 default: 1398 if (htab->target_os == is_vxworks 1399 && elf_vxworks_finish_dynamic_entry (output_bfd, &dyn)) 1400 break; 1401 continue; 1402 1403 case DT_PLTGOT: 1404 s = htab->elf.sgotplt; 1405 dyn.d_un.d_ptr = s->output_section->vma + s->output_offset; 1406 break; 1407 1408 case DT_JMPREL: 1409 dyn.d_un.d_ptr = htab->elf.srelplt->output_section->vma; 1410 break; 1411 1412 case DT_PLTRELSZ: 1413 s = htab->elf.srelplt->output_section; 1414 dyn.d_un.d_val = s->size; 1415 break; 1416 1417 case DT_TLSDESC_PLT: 1418 s = htab->elf.splt; 1419 dyn.d_un.d_ptr = s->output_section->vma + s->output_offset 1420 + htab->tlsdesc_plt; 1421 break; 1422 1423 case DT_TLSDESC_GOT: 1424 s = htab->elf.sgot; 1425 dyn.d_un.d_ptr = s->output_section->vma + s->output_offset 1426 + htab->tlsdesc_got; 1427 break; 1428 } 1429 1430 (*bed->s->swap_dyn_out) (output_bfd, &dyn, dyncon); 1431 } 1432 1433 if (htab->plt_got != NULL && htab->plt_got->size > 0) 1434 elf_section_data (htab->plt_got->output_section) 1435 ->this_hdr.sh_entsize = htab->non_lazy_plt->plt_entry_size; 1436 1437 if (htab->plt_second != NULL && htab->plt_second->size > 0) 1438 elf_section_data (htab->plt_second->output_section) 1439 ->this_hdr.sh_entsize = htab->non_lazy_plt->plt_entry_size; 1440 1441 /* Adjust .eh_frame for .plt section. */ 1442 if (htab->plt_eh_frame != NULL 1443 && htab->plt_eh_frame->contents != NULL) 1444 { 1445 if (htab->elf.splt != NULL 1446 && htab->elf.splt->size != 0 1447 && (htab->elf.splt->flags & SEC_EXCLUDE) == 0 1448 && htab->elf.splt->output_section != NULL 1449 && htab->plt_eh_frame->output_section != NULL) 1450 { 1451 bfd_vma plt_start = htab->elf.splt->output_section->vma; 1452 bfd_vma eh_frame_start = htab->plt_eh_frame->output_section->vma 1453 + htab->plt_eh_frame->output_offset 1454 + PLT_FDE_START_OFFSET; 1455 bfd_put_signed_32 (dynobj, plt_start - eh_frame_start, 1456 htab->plt_eh_frame->contents 1457 + PLT_FDE_START_OFFSET); 1458 } 1459 1460 if (htab->plt_eh_frame->sec_info_type == SEC_INFO_TYPE_EH_FRAME) 1461 { 1462 if (! _bfd_elf_write_section_eh_frame (output_bfd, info, 1463 htab->plt_eh_frame, 1464 htab->plt_eh_frame->contents)) 1465 return NULL; 1466 } 1467 } 1468 1469 /* Adjust .eh_frame for .plt.got section. */ 1470 if (htab->plt_got_eh_frame != NULL 1471 && htab->plt_got_eh_frame->contents != NULL) 1472 { 1473 if (htab->plt_got != NULL 1474 && htab->plt_got->size != 0 1475 && (htab->plt_got->flags & SEC_EXCLUDE) == 0 1476 && htab->plt_got->output_section != NULL 1477 && htab->plt_got_eh_frame->output_section != NULL) 1478 { 1479 bfd_vma plt_start = htab->plt_got->output_section->vma; 1480 bfd_vma eh_frame_start = htab->plt_got_eh_frame->output_section->vma 1481 + htab->plt_got_eh_frame->output_offset 1482 + PLT_FDE_START_OFFSET; 1483 bfd_put_signed_32 (dynobj, plt_start - eh_frame_start, 1484 htab->plt_got_eh_frame->contents 1485 + PLT_FDE_START_OFFSET); 1486 } 1487 if (htab->plt_got_eh_frame->sec_info_type == SEC_INFO_TYPE_EH_FRAME) 1488 { 1489 if (! _bfd_elf_write_section_eh_frame (output_bfd, info, 1490 htab->plt_got_eh_frame, 1491 htab->plt_got_eh_frame->contents)) 1492 return NULL; 1493 } 1494 } 1495 1496 /* Adjust .eh_frame for the second PLT section. */ 1497 if (htab->plt_second_eh_frame != NULL 1498 && htab->plt_second_eh_frame->contents != NULL) 1499 { 1500 if (htab->plt_second != NULL 1501 && htab->plt_second->size != 0 1502 && (htab->plt_second->flags & SEC_EXCLUDE) == 0 1503 && htab->plt_second->output_section != NULL 1504 && htab->plt_second_eh_frame->output_section != NULL) 1505 { 1506 bfd_vma plt_start = htab->plt_second->output_section->vma; 1507 bfd_vma eh_frame_start 1508 = (htab->plt_second_eh_frame->output_section->vma 1509 + htab->plt_second_eh_frame->output_offset 1510 + PLT_FDE_START_OFFSET); 1511 bfd_put_signed_32 (dynobj, plt_start - eh_frame_start, 1512 htab->plt_second_eh_frame->contents 1513 + PLT_FDE_START_OFFSET); 1514 } 1515 if (htab->plt_second_eh_frame->sec_info_type 1516 == SEC_INFO_TYPE_EH_FRAME) 1517 { 1518 if (! _bfd_elf_write_section_eh_frame (output_bfd, info, 1519 htab->plt_second_eh_frame, 1520 htab->plt_second_eh_frame->contents)) 1521 return NULL; 1522 } 1523 } 1524 1525 if (htab->elf.sgot && htab->elf.sgot->size > 0) 1526 elf_section_data (htab->elf.sgot->output_section)->this_hdr.sh_entsize 1527 = htab->got_entry_size; 1528 1529 return htab; 1530 } 1531 1532 1533 bfd_boolean 1534 _bfd_x86_elf_always_size_sections (bfd *output_bfd, 1535 struct bfd_link_info *info) 1536 { 1537 asection *tls_sec = elf_hash_table (info)->tls_sec; 1538 1539 if (tls_sec) 1540 { 1541 struct elf_link_hash_entry *tlsbase; 1542 1543 tlsbase = elf_link_hash_lookup (elf_hash_table (info), 1544 "_TLS_MODULE_BASE_", 1545 FALSE, FALSE, FALSE); 1546 1547 if (tlsbase && tlsbase->type == STT_TLS) 1548 { 1549 struct elf_x86_link_hash_table *htab; 1550 struct bfd_link_hash_entry *bh = NULL; 1551 const struct elf_backend_data *bed 1552 = get_elf_backend_data (output_bfd); 1553 1554 htab = elf_x86_hash_table (info, bed->target_id); 1555 if (htab == NULL) 1556 return FALSE; 1557 1558 if (!(_bfd_generic_link_add_one_symbol 1559 (info, output_bfd, "_TLS_MODULE_BASE_", BSF_LOCAL, 1560 tls_sec, 0, NULL, FALSE, 1561 bed->collect, &bh))) 1562 return FALSE; 1563 1564 htab->tls_module_base = bh; 1565 1566 tlsbase = (struct elf_link_hash_entry *)bh; 1567 tlsbase->def_regular = 1; 1568 tlsbase->other = STV_HIDDEN; 1569 tlsbase->root.linker_def = 1; 1570 (*bed->elf_backend_hide_symbol) (info, tlsbase, TRUE); 1571 } 1572 } 1573 1574 return TRUE; 1575 } 1576 1577 void 1578 _bfd_x86_elf_merge_symbol_attribute (struct elf_link_hash_entry *h, 1579 const Elf_Internal_Sym *isym, 1580 bfd_boolean definition, 1581 bfd_boolean dynamic ATTRIBUTE_UNUSED) 1582 { 1583 if (definition) 1584 { 1585 struct elf_x86_link_hash_entry *eh 1586 = (struct elf_x86_link_hash_entry *) h; 1587 eh->def_protected = (ELF_ST_VISIBILITY (isym->st_other) 1588 == STV_PROTECTED); 1589 } 1590 } 1591 1592 /* Copy the extra info we tack onto an elf_link_hash_entry. */ 1593 1594 void 1595 _bfd_x86_elf_copy_indirect_symbol (struct bfd_link_info *info, 1596 struct elf_link_hash_entry *dir, 1597 struct elf_link_hash_entry *ind) 1598 { 1599 struct elf_x86_link_hash_entry *edir, *eind; 1600 1601 edir = (struct elf_x86_link_hash_entry *) dir; 1602 eind = (struct elf_x86_link_hash_entry *) ind; 1603 1604 if (eind->dyn_relocs != NULL) 1605 { 1606 if (edir->dyn_relocs != NULL) 1607 { 1608 struct elf_dyn_relocs **pp; 1609 struct elf_dyn_relocs *p; 1610 1611 /* Add reloc counts against the indirect sym to the direct sym 1612 list. Merge any entries against the same section. */ 1613 for (pp = &eind->dyn_relocs; (p = *pp) != NULL; ) 1614 { 1615 struct elf_dyn_relocs *q; 1616 1617 for (q = edir->dyn_relocs; q != NULL; q = q->next) 1618 if (q->sec == p->sec) 1619 { 1620 q->pc_count += p->pc_count; 1621 q->count += p->count; 1622 *pp = p->next; 1623 break; 1624 } 1625 if (q == NULL) 1626 pp = &p->next; 1627 } 1628 *pp = edir->dyn_relocs; 1629 } 1630 1631 edir->dyn_relocs = eind->dyn_relocs; 1632 eind->dyn_relocs = NULL; 1633 } 1634 1635 if (ind->root.type == bfd_link_hash_indirect 1636 && dir->got.refcount <= 0) 1637 { 1638 edir->tls_type = eind->tls_type; 1639 eind->tls_type = GOT_UNKNOWN; 1640 } 1641 1642 /* Copy gotoff_ref so that elf_i386_adjust_dynamic_symbol will 1643 generate a R_386_COPY reloc. */ 1644 edir->gotoff_ref |= eind->gotoff_ref; 1645 1646 edir->zero_undefweak |= eind->zero_undefweak; 1647 1648 if (ELIMINATE_COPY_RELOCS 1649 && ind->root.type != bfd_link_hash_indirect 1650 && dir->dynamic_adjusted) 1651 { 1652 /* If called to transfer flags for a weakdef during processing 1653 of elf_adjust_dynamic_symbol, don't copy non_got_ref. 1654 We clear it ourselves for ELIMINATE_COPY_RELOCS. */ 1655 if (dir->versioned != versioned_hidden) 1656 dir->ref_dynamic |= ind->ref_dynamic; 1657 dir->ref_regular |= ind->ref_regular; 1658 dir->ref_regular_nonweak |= ind->ref_regular_nonweak; 1659 dir->needs_plt |= ind->needs_plt; 1660 dir->pointer_equality_needed |= ind->pointer_equality_needed; 1661 } 1662 else 1663 _bfd_elf_link_hash_copy_indirect (info, dir, ind); 1664 } 1665 1666 /* Remove undefined weak symbol from the dynamic symbol table if it 1667 is resolved to 0. */ 1668 1669 bfd_boolean 1670 _bfd_x86_elf_fixup_symbol (struct bfd_link_info *info, 1671 struct elf_link_hash_entry *h) 1672 { 1673 if (h->dynindx != -1 1674 && UNDEFINED_WEAK_RESOLVED_TO_ZERO (info, elf_x86_hash_entry (h))) 1675 { 1676 h->dynindx = -1; 1677 _bfd_elf_strtab_delref (elf_hash_table (info)->dynstr, 1678 h->dynstr_index); 1679 } 1680 return TRUE; 1681 } 1682 1683 /* Return TRUE if symbol should be hashed in the `.gnu.hash' section. */ 1684 1685 bfd_boolean 1686 _bfd_x86_elf_hash_symbol (struct elf_link_hash_entry *h) 1687 { 1688 if (h->plt.offset != (bfd_vma) -1 1689 && !h->def_regular 1690 && !h->pointer_equality_needed) 1691 return FALSE; 1692 1693 return _bfd_elf_hash_symbol (h); 1694 } 1695 1696 /* Adjust a symbol defined by a dynamic object and referenced by a 1697 regular object. The current definition is in some section of the 1698 dynamic object, but we're not including those sections. We have to 1699 change the definition to something the rest of the link can 1700 understand. */ 1701 1702 bfd_boolean 1703 _bfd_x86_elf_adjust_dynamic_symbol (struct bfd_link_info *info, 1704 struct elf_link_hash_entry *h) 1705 { 1706 struct elf_x86_link_hash_table *htab; 1707 asection *s, *srel; 1708 struct elf_x86_link_hash_entry *eh; 1709 struct elf_dyn_relocs *p; 1710 const struct elf_backend_data *bed 1711 = get_elf_backend_data (info->output_bfd); 1712 1713 /* STT_GNU_IFUNC symbol must go through PLT. */ 1714 if (h->type == STT_GNU_IFUNC) 1715 { 1716 /* All local STT_GNU_IFUNC references must be treate as local 1717 calls via local PLT. */ 1718 if (h->ref_regular 1719 && SYMBOL_CALLS_LOCAL (info, h)) 1720 { 1721 bfd_size_type pc_count = 0, count = 0; 1722 struct elf_dyn_relocs **pp; 1723 1724 eh = (struct elf_x86_link_hash_entry *) h; 1725 for (pp = &eh->dyn_relocs; (p = *pp) != NULL; ) 1726 { 1727 pc_count += p->pc_count; 1728 p->count -= p->pc_count; 1729 p->pc_count = 0; 1730 count += p->count; 1731 if (p->count == 0) 1732 *pp = p->next; 1733 else 1734 pp = &p->next; 1735 } 1736 1737 if (pc_count || count) 1738 { 1739 h->non_got_ref = 1; 1740 if (pc_count) 1741 { 1742 /* Increment PLT reference count only for PC-relative 1743 references. */ 1744 h->needs_plt = 1; 1745 if (h->plt.refcount <= 0) 1746 h->plt.refcount = 1; 1747 else 1748 h->plt.refcount += 1; 1749 } 1750 } 1751 } 1752 1753 if (h->plt.refcount <= 0) 1754 { 1755 h->plt.offset = (bfd_vma) -1; 1756 h->needs_plt = 0; 1757 } 1758 return TRUE; 1759 } 1760 1761 /* If this is a function, put it in the procedure linkage table. We 1762 will fill in the contents of the procedure linkage table later, 1763 when we know the address of the .got section. */ 1764 if (h->type == STT_FUNC 1765 || h->needs_plt) 1766 { 1767 if (h->plt.refcount <= 0 1768 || SYMBOL_CALLS_LOCAL (info, h) 1769 || (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT 1770 && h->root.type == bfd_link_hash_undefweak)) 1771 { 1772 /* This case can occur if we saw a PLT32 reloc in an input 1773 file, but the symbol was never referred to by a dynamic 1774 object, or if all references were garbage collected. In 1775 such a case, we don't actually need to build a procedure 1776 linkage table, and we can just do a PC32 reloc instead. */ 1777 h->plt.offset = (bfd_vma) -1; 1778 h->needs_plt = 0; 1779 } 1780 1781 return TRUE; 1782 } 1783 else 1784 /* It's possible that we incorrectly decided a .plt reloc was needed 1785 * for an R_386_PC32/R_X86_64_PC32 reloc to a non-function sym in 1786 check_relocs. We can't decide accurately between function and 1787 non-function syms in check-relocs; Objects loaded later in 1788 the link may change h->type. So fix it now. */ 1789 h->plt.offset = (bfd_vma) -1; 1790 1791 eh = (struct elf_x86_link_hash_entry *) h; 1792 1793 /* If this is a weak symbol, and there is a real definition, the 1794 processor independent code will have arranged for us to see the 1795 real definition first, and we can just use the same value. */ 1796 if (h->is_weakalias) 1797 { 1798 struct elf_link_hash_entry *def = weakdef (h); 1799 BFD_ASSERT (def->root.type == bfd_link_hash_defined); 1800 h->root.u.def.section = def->root.u.def.section; 1801 h->root.u.def.value = def->root.u.def.value; 1802 if (ELIMINATE_COPY_RELOCS 1803 || info->nocopyreloc 1804 || SYMBOL_NO_COPYRELOC (info, eh)) 1805 { 1806 /* NB: needs_copy is always 0 for i386. */ 1807 h->non_got_ref = def->non_got_ref; 1808 eh->needs_copy = def->needs_copy; 1809 } 1810 return TRUE; 1811 } 1812 1813 /* This is a reference to a symbol defined by a dynamic object which 1814 is not a function. */ 1815 1816 /* If we are creating a shared library, we must presume that the 1817 only references to the symbol are via the global offset table. 1818 For such cases we need not do anything here; the relocations will 1819 be handled correctly by relocate_section. */ 1820 if (!bfd_link_executable (info)) 1821 return TRUE; 1822 1823 /* If there are no references to this symbol that do not use the 1824 GOT nor R_386_GOTOFF relocation, we don't need to generate a copy 1825 reloc. NB: gotoff_ref is always 0 for x86-64. */ 1826 if (!h->non_got_ref && !eh->gotoff_ref) 1827 return TRUE; 1828 1829 /* If -z nocopyreloc was given, we won't generate them either. */ 1830 if (info->nocopyreloc || SYMBOL_NO_COPYRELOC (info, eh)) 1831 { 1832 h->non_got_ref = 0; 1833 return TRUE; 1834 } 1835 1836 htab = elf_x86_hash_table (info, bed->target_id); 1837 if (htab == NULL) 1838 return FALSE; 1839 1840 /* If there aren't any dynamic relocs in read-only sections nor 1841 R_386_GOTOFF relocation, then we can keep the dynamic relocs and 1842 avoid the copy reloc. This doesn't work on VxWorks, where we can 1843 not have dynamic relocations (other than copy and jump slot 1844 relocations) in an executable. */ 1845 if (ELIMINATE_COPY_RELOCS 1846 && (bed->target_id == X86_64_ELF_DATA 1847 || (!eh->gotoff_ref 1848 && htab->target_os != is_vxworks))) 1849 { 1850 /* If we don't find any dynamic relocs in read-only sections, 1851 then we'll be keeping the dynamic relocs and avoiding the copy 1852 reloc. */ 1853 if (!readonly_dynrelocs (h)) 1854 { 1855 h->non_got_ref = 0; 1856 return TRUE; 1857 } 1858 } 1859 1860 /* We must allocate the symbol in our .dynbss section, which will 1861 become part of the .bss section of the executable. There will be 1862 an entry for this symbol in the .dynsym section. The dynamic 1863 object will contain position independent code, so all references 1864 from the dynamic object to this symbol will go through the global 1865 offset table. The dynamic linker will use the .dynsym entry to 1866 determine the address it must put in the global offset table, so 1867 both the dynamic object and the regular object will refer to the 1868 same memory location for the variable. */ 1869 1870 /* We must generate a R_386_COPY/R_X86_64_COPY reloc to tell the 1871 dynamic linker to copy the initial value out of the dynamic object 1872 and into the runtime process image. */ 1873 if ((h->root.u.def.section->flags & SEC_READONLY) != 0) 1874 { 1875 s = htab->elf.sdynrelro; 1876 srel = htab->elf.sreldynrelro; 1877 } 1878 else 1879 { 1880 s = htab->elf.sdynbss; 1881 srel = htab->elf.srelbss; 1882 } 1883 if ((h->root.u.def.section->flags & SEC_ALLOC) != 0 && h->size != 0) 1884 { 1885 srel->size += htab->sizeof_reloc; 1886 h->needs_copy = 1; 1887 } 1888 1889 return _bfd_elf_adjust_dynamic_copy (info, h, s); 1890 } 1891 1892 void 1893 _bfd_x86_elf_hide_symbol (struct bfd_link_info *info, 1894 struct elf_link_hash_entry *h, 1895 bfd_boolean force_local) 1896 { 1897 if (h->root.type == bfd_link_hash_undefweak 1898 && info->nointerp 1899 && bfd_link_pie (info)) 1900 { 1901 /* When there is no dynamic interpreter in PIE, make the undefined 1902 weak symbol dynamic so that PC relative branch to the undefined 1903 weak symbol will land to address 0. */ 1904 struct elf_x86_link_hash_entry *eh = elf_x86_hash_entry (h); 1905 if (h->plt.refcount > 0 1906 || eh->plt_got.refcount > 0) 1907 return; 1908 } 1909 1910 _bfd_elf_link_hash_hide_symbol (info, h, force_local); 1911 } 1912 1913 /* Return TRUE if a symbol is referenced locally. It is similar to 1914 SYMBOL_REFERENCES_LOCAL, but it also checks version script. It 1915 works in check_relocs. */ 1916 1917 bfd_boolean 1918 _bfd_x86_elf_link_symbol_references_local (struct bfd_link_info *info, 1919 struct elf_link_hash_entry *h) 1920 { 1921 struct elf_x86_link_hash_entry *eh = elf_x86_hash_entry (h); 1922 struct elf_x86_link_hash_table *htab 1923 = (struct elf_x86_link_hash_table *) info->hash; 1924 1925 if (eh->local_ref > 1) 1926 return TRUE; 1927 1928 if (eh->local_ref == 1) 1929 return FALSE; 1930 1931 /* Unversioned symbols defined in regular objects can be forced local 1932 by linker version script. A weak undefined symbol is forced local 1933 if 1934 1. It has non-default visibility. Or 1935 2. When building executable, there is no dynamic linker. Or 1936 3. or "-z nodynamic-undefined-weak" is used. 1937 */ 1938 if (SYMBOL_REFERENCES_LOCAL (info, h) 1939 || (h->root.type == bfd_link_hash_undefweak 1940 && (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT 1941 || (bfd_link_executable (info) 1942 && htab->interp == NULL) 1943 || info->dynamic_undefined_weak == 0)) 1944 || ((h->def_regular || ELF_COMMON_DEF_P (h)) 1945 && h->versioned == unversioned 1946 && info->version_info != NULL 1947 && bfd_hide_sym_by_version (info->version_info, 1948 h->root.root.string))) 1949 { 1950 eh->local_ref = 2; 1951 return TRUE; 1952 } 1953 1954 eh->local_ref = 1; 1955 return FALSE; 1956 } 1957 1958 /* Return the section that should be marked against GC for a given 1959 relocation. */ 1960 1961 asection * 1962 _bfd_x86_elf_gc_mark_hook (asection *sec, 1963 struct bfd_link_info *info, 1964 Elf_Internal_Rela *rel, 1965 struct elf_link_hash_entry *h, 1966 Elf_Internal_Sym *sym) 1967 { 1968 /* Compiler should optimize this out. */ 1969 if (((unsigned int) R_X86_64_GNU_VTINHERIT 1970 != (unsigned int) R_386_GNU_VTINHERIT) 1971 || ((unsigned int) R_X86_64_GNU_VTENTRY 1972 != (unsigned int) R_386_GNU_VTENTRY)) 1973 abort (); 1974 1975 if (h != NULL) 1976 switch (ELF32_R_TYPE (rel->r_info)) 1977 { 1978 case R_X86_64_GNU_VTINHERIT: 1979 case R_X86_64_GNU_VTENTRY: 1980 return NULL; 1981 } 1982 1983 return _bfd_elf_gc_mark_hook (sec, info, rel, h, sym); 1984 } 1985 1986 static bfd_vma 1987 elf_i386_get_plt_got_vma (struct elf_x86_plt *plt_p ATTRIBUTE_UNUSED, 1988 bfd_vma off, 1989 bfd_vma offset ATTRIBUTE_UNUSED, 1990 bfd_vma got_addr) 1991 { 1992 return got_addr + off; 1993 } 1994 1995 static bfd_vma 1996 elf_x86_64_get_plt_got_vma (struct elf_x86_plt *plt_p, 1997 bfd_vma off, 1998 bfd_vma offset, 1999 bfd_vma got_addr ATTRIBUTE_UNUSED) 2000 { 2001 return plt_p->sec->vma + offset + off + plt_p->plt_got_insn_size; 2002 } 2003 2004 static bfd_boolean 2005 elf_i386_valid_plt_reloc_p (unsigned int type) 2006 { 2007 return (type == R_386_JUMP_SLOT 2008 || type == R_386_GLOB_DAT 2009 || type == R_386_IRELATIVE); 2010 } 2011 2012 static bfd_boolean 2013 elf_x86_64_valid_plt_reloc_p (unsigned int type) 2014 { 2015 return (type == R_X86_64_JUMP_SLOT 2016 || type == R_X86_64_GLOB_DAT 2017 || type == R_X86_64_IRELATIVE); 2018 } 2019 2020 long 2021 _bfd_x86_elf_get_synthetic_symtab (bfd *abfd, 2022 long count, 2023 long relsize, 2024 bfd_vma got_addr, 2025 struct elf_x86_plt plts[], 2026 asymbol **dynsyms, 2027 asymbol **ret) 2028 { 2029 long size, i, n, len; 2030 int j; 2031 unsigned int plt_got_offset, plt_entry_size; 2032 asymbol *s; 2033 bfd_byte *plt_contents; 2034 long dynrelcount; 2035 arelent **dynrelbuf, *p; 2036 char *names; 2037 const struct elf_backend_data *bed; 2038 bfd_vma (*get_plt_got_vma) (struct elf_x86_plt *, bfd_vma, bfd_vma, 2039 bfd_vma); 2040 bfd_boolean (*valid_plt_reloc_p) (unsigned int); 2041 2042 if (count == 0) 2043 return -1; 2044 2045 dynrelbuf = (arelent **) bfd_malloc (relsize); 2046 if (dynrelbuf == NULL) 2047 return -1; 2048 2049 dynrelcount = bfd_canonicalize_dynamic_reloc (abfd, dynrelbuf, 2050 dynsyms); 2051 if (dynrelcount <= 0) 2052 return -1; 2053 2054 /* Sort the relocs by address. */ 2055 qsort (dynrelbuf, dynrelcount, sizeof (arelent *), 2056 _bfd_x86_elf_compare_relocs); 2057 2058 size = count * sizeof (asymbol); 2059 2060 /* Allocate space for @plt suffixes. */ 2061 n = 0; 2062 for (i = 0; i < dynrelcount; i++) 2063 { 2064 p = dynrelbuf[i]; 2065 size += strlen ((*p->sym_ptr_ptr)->name) + sizeof ("@plt"); 2066 if (p->addend != 0) 2067 size += sizeof ("+0x") - 1 + 8 + 8 * ABI_64_P (abfd); 2068 } 2069 2070 s = *ret = (asymbol *) bfd_zmalloc (size); 2071 if (s == NULL) 2072 goto bad_return; 2073 2074 bed = get_elf_backend_data (abfd); 2075 2076 if (bed->target_id == X86_64_ELF_DATA) 2077 { 2078 get_plt_got_vma = elf_x86_64_get_plt_got_vma; 2079 valid_plt_reloc_p = elf_x86_64_valid_plt_reloc_p; 2080 } 2081 else 2082 { 2083 get_plt_got_vma = elf_i386_get_plt_got_vma; 2084 valid_plt_reloc_p = elf_i386_valid_plt_reloc_p; 2085 if (got_addr) 2086 { 2087 /* Check .got.plt and then .got to get the _GLOBAL_OFFSET_TABLE_ 2088 address. */ 2089 asection *sec = bfd_get_section_by_name (abfd, ".got.plt"); 2090 if (sec != NULL) 2091 got_addr = sec->vma; 2092 else 2093 { 2094 sec = bfd_get_section_by_name (abfd, ".got"); 2095 if (sec != NULL) 2096 got_addr = sec->vma; 2097 } 2098 2099 if (got_addr == (bfd_vma) -1) 2100 goto bad_return; 2101 } 2102 } 2103 2104 /* Check for each PLT section. */ 2105 names = (char *) (s + count); 2106 size = 0; 2107 n = 0; 2108 for (j = 0; plts[j].name != NULL; j++) 2109 if ((plt_contents = plts[j].contents) != NULL) 2110 { 2111 long k; 2112 bfd_vma offset; 2113 asection *plt; 2114 struct elf_x86_plt *plt_p = &plts[j]; 2115 2116 plt_got_offset = plt_p->plt_got_offset; 2117 plt_entry_size = plt_p->plt_entry_size; 2118 2119 plt = plt_p->sec; 2120 2121 if ((plt_p->type & plt_lazy)) 2122 { 2123 /* Skip PLT0 in lazy PLT. */ 2124 k = 1; 2125 offset = plt_entry_size; 2126 } 2127 else 2128 { 2129 k = 0; 2130 offset = 0; 2131 } 2132 2133 /* Check each PLT entry against dynamic relocations. */ 2134 for (; k < plt_p->count; k++) 2135 { 2136 int off; 2137 bfd_vma got_vma; 2138 long min, max, mid; 2139 2140 /* Get the GOT offset for i386 or the PC-relative offset 2141 for x86-64, a signed 32-bit integer. */ 2142 off = H_GET_32 (abfd, (plt_contents + offset 2143 + plt_got_offset)); 2144 got_vma = get_plt_got_vma (plt_p, off, offset, got_addr); 2145 2146 /* Binary search. */ 2147 p = dynrelbuf[0]; 2148 min = 0; 2149 max = dynrelcount; 2150 while ((min + 1) < max) 2151 { 2152 arelent *r; 2153 2154 mid = (min + max) / 2; 2155 r = dynrelbuf[mid]; 2156 if (got_vma > r->address) 2157 min = mid; 2158 else if (got_vma < r->address) 2159 max = mid; 2160 else 2161 { 2162 p = r; 2163 break; 2164 } 2165 } 2166 2167 /* Skip unknown relocation. PR 17512: file: bc9d6cf5. */ 2168 if (got_vma == p->address 2169 && p->howto != NULL 2170 && valid_plt_reloc_p (p->howto->type)) 2171 { 2172 *s = **p->sym_ptr_ptr; 2173 /* Undefined syms won't have BSF_LOCAL or BSF_GLOBAL 2174 set. Since we are defining a symbol, ensure one 2175 of them is set. */ 2176 if ((s->flags & BSF_LOCAL) == 0) 2177 s->flags |= BSF_GLOBAL; 2178 s->flags |= BSF_SYNTHETIC; 2179 /* This is no longer a section symbol. */ 2180 s->flags &= ~BSF_SECTION_SYM; 2181 s->section = plt; 2182 s->the_bfd = plt->owner; 2183 s->value = offset; 2184 s->udata.p = NULL; 2185 s->name = names; 2186 len = strlen ((*p->sym_ptr_ptr)->name); 2187 memcpy (names, (*p->sym_ptr_ptr)->name, len); 2188 names += len; 2189 if (p->addend != 0) 2190 { 2191 char buf[30], *a; 2192 2193 memcpy (names, "+0x", sizeof ("+0x") - 1); 2194 names += sizeof ("+0x") - 1; 2195 bfd_sprintf_vma (abfd, buf, p->addend); 2196 for (a = buf; *a == '0'; ++a) 2197 ; 2198 size = strlen (a); 2199 memcpy (names, a, size); 2200 names += size; 2201 } 2202 memcpy (names, "@plt", sizeof ("@plt")); 2203 names += sizeof ("@plt"); 2204 n++; 2205 s++; 2206 /* There should be only one entry in PLT for a given 2207 symbol. Set howto to NULL after processing a PLT 2208 entry to guard against corrupted PLT. */ 2209 p->howto = NULL; 2210 } 2211 offset += plt_entry_size; 2212 } 2213 } 2214 2215 /* PLT entries with R_386_TLS_DESC relocations are skipped. */ 2216 if (n == 0) 2217 { 2218 bad_return: 2219 count = -1; 2220 } 2221 else 2222 count = n; 2223 2224 for (j = 0; plts[j].name != NULL; j++) 2225 if (plts[j].contents != NULL) 2226 free (plts[j].contents); 2227 2228 free (dynrelbuf); 2229 2230 return count; 2231 } 2232 2233 /* Parse x86 GNU properties. */ 2234 2235 enum elf_property_kind 2236 _bfd_x86_elf_parse_gnu_properties (bfd *abfd, unsigned int type, 2237 bfd_byte *ptr, unsigned int datasz) 2238 { 2239 elf_property *prop; 2240 2241 switch (type) 2242 { 2243 case GNU_PROPERTY_X86_ISA_1_USED: 2244 case GNU_PROPERTY_X86_ISA_1_NEEDED: 2245 case GNU_PROPERTY_X86_FEATURE_1_AND: 2246 if (datasz != 4) 2247 { 2248 _bfd_error_handler 2249 ((type == GNU_PROPERTY_X86_ISA_1_USED 2250 ? _("error: %B: <corrupt x86 ISA used size: 0x%x>") 2251 : (type == GNU_PROPERTY_X86_ISA_1_NEEDED 2252 ? _("error: %B: <corrupt x86 ISA needed size: 0x%x>") 2253 : _("error: %B: <corrupt x86 feature size: 0x%x>"))), 2254 abfd, datasz); 2255 return property_corrupt; 2256 } 2257 prop = _bfd_elf_get_property (abfd, type, datasz); 2258 /* Combine properties of the same type. */ 2259 prop->u.number |= bfd_h_get_32 (abfd, ptr); 2260 prop->pr_kind = property_number; 2261 break; 2262 2263 default: 2264 return property_ignored; 2265 } 2266 2267 return property_number; 2268 } 2269 2270 /* Merge x86 GNU property BPROP with APROP. If APROP isn't NULL, 2271 return TRUE if APROP is updated. Otherwise, return TRUE if BPROP 2272 should be merged with ABFD. */ 2273 2274 bfd_boolean 2275 _bfd_x86_elf_merge_gnu_properties (struct bfd_link_info *info, 2276 bfd *abfd ATTRIBUTE_UNUSED, 2277 elf_property *aprop, 2278 elf_property *bprop) 2279 { 2280 unsigned int number, features; 2281 bfd_boolean updated = FALSE; 2282 unsigned int pr_type = aprop != NULL ? aprop->pr_type : bprop->pr_type; 2283 2284 switch (pr_type) 2285 { 2286 case GNU_PROPERTY_X86_ISA_1_USED: 2287 case GNU_PROPERTY_X86_ISA_1_NEEDED: 2288 if (aprop != NULL && bprop != NULL) 2289 { 2290 number = aprop->u.number; 2291 aprop->u.number = number | bprop->u.number; 2292 updated = number != (unsigned int) aprop->u.number; 2293 } 2294 else 2295 { 2296 /* Return TRUE if APROP is NULL to indicate that BPROP should 2297 be added to ABFD. */ 2298 updated = aprop == NULL; 2299 } 2300 break; 2301 2302 case GNU_PROPERTY_X86_FEATURE_1_AND: 2303 /* Only one of APROP and BPROP can be NULL: 2304 1. APROP & BPROP when both APROP and BPROP aren't NULL. 2305 2. If APROP is NULL, remove x86 feature. 2306 3. Otherwise, do nothing. 2307 */ 2308 if (aprop != NULL && bprop != NULL) 2309 { 2310 features = 0; 2311 if (info->ibt) 2312 features = GNU_PROPERTY_X86_FEATURE_1_IBT; 2313 if (info->shstk) 2314 features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK; 2315 number = aprop->u.number; 2316 /* Add GNU_PROPERTY_X86_FEATURE_1_IBT and 2317 GNU_PROPERTY_X86_FEATURE_1_SHSTK. */ 2318 aprop->u.number = (number & bprop->u.number) | features; 2319 updated = number != (unsigned int) aprop->u.number; 2320 /* Remove the property if all feature bits are cleared. */ 2321 if (aprop->u.number == 0) 2322 aprop->pr_kind = property_remove; 2323 } 2324 else 2325 { 2326 features = 0; 2327 if (info->ibt) 2328 features = GNU_PROPERTY_X86_FEATURE_1_IBT; 2329 if (info->shstk) 2330 features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK; 2331 if (features) 2332 { 2333 /* Add GNU_PROPERTY_X86_FEATURE_1_IBT and 2334 GNU_PROPERTY_X86_FEATURE_1_SHSTK. */ 2335 if (aprop != NULL) 2336 { 2337 number = aprop->u.number; 2338 aprop->u.number = number | features; 2339 updated = number != (unsigned int) aprop->u.number; 2340 } 2341 else 2342 { 2343 bprop->u.number |= features; 2344 updated = TRUE; 2345 } 2346 } 2347 else if (aprop != NULL) 2348 { 2349 aprop->pr_kind = property_remove; 2350 updated = TRUE; 2351 } 2352 } 2353 break; 2354 2355 default: 2356 /* Never should happen. */ 2357 abort (); 2358 } 2359 2360 return updated; 2361 } 2362 2363 /* Set up x86 GNU properties. Return the first relocatable ELF input 2364 with GNU properties if found. Otherwise, return NULL. */ 2365 2366 bfd * 2367 _bfd_x86_elf_link_setup_gnu_properties 2368 (struct bfd_link_info *info, struct elf_x86_init_table *init_table) 2369 { 2370 bfd_boolean normal_target; 2371 bfd_boolean lazy_plt; 2372 asection *sec, *pltsec; 2373 bfd *dynobj; 2374 bfd_boolean use_ibt_plt; 2375 unsigned int plt_alignment, features; 2376 struct elf_x86_link_hash_table *htab; 2377 bfd *pbfd; 2378 bfd *ebfd = NULL; 2379 elf_property *prop; 2380 const struct elf_backend_data *bed; 2381 unsigned int class_align = ABI_64_P (info->output_bfd) ? 3 : 2; 2382 unsigned int got_align; 2383 2384 features = 0; 2385 if (info->ibt) 2386 features = GNU_PROPERTY_X86_FEATURE_1_IBT; 2387 if (info->shstk) 2388 features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK; 2389 2390 /* Find a normal input file with GNU property note. */ 2391 for (pbfd = info->input_bfds; 2392 pbfd != NULL; 2393 pbfd = pbfd->link.next) 2394 if (bfd_get_flavour (pbfd) == bfd_target_elf_flavour 2395 && bfd_count_sections (pbfd) != 0) 2396 { 2397 ebfd = pbfd; 2398 2399 if (elf_properties (pbfd) != NULL) 2400 break; 2401 } 2402 2403 if (ebfd != NULL && features) 2404 { 2405 /* If features is set, add GNU_PROPERTY_X86_FEATURE_1_IBT and 2406 GNU_PROPERTY_X86_FEATURE_1_SHSTK. */ 2407 prop = _bfd_elf_get_property (ebfd, 2408 GNU_PROPERTY_X86_FEATURE_1_AND, 2409 4); 2410 prop->u.number |= features; 2411 prop->pr_kind = property_number; 2412 2413 /* Create the GNU property note section if needed. */ 2414 if (pbfd == NULL) 2415 { 2416 sec = bfd_make_section_with_flags (ebfd, 2417 NOTE_GNU_PROPERTY_SECTION_NAME, 2418 (SEC_ALLOC 2419 | SEC_LOAD 2420 | SEC_IN_MEMORY 2421 | SEC_READONLY 2422 | SEC_HAS_CONTENTS 2423 | SEC_DATA)); 2424 if (sec == NULL) 2425 info->callbacks->einfo (_("%F%P: failed to create GNU property section\n")); 2426 2427 if (!bfd_set_section_alignment (ebfd, sec, class_align)) 2428 { 2429 error_alignment: 2430 info->callbacks->einfo (_("%F%A: failed to align section\n"), 2431 sec); 2432 } 2433 2434 elf_section_type (sec) = SHT_NOTE; 2435 } 2436 } 2437 2438 pbfd = _bfd_elf_link_setup_gnu_properties (info); 2439 2440 bed = get_elf_backend_data (info->output_bfd); 2441 2442 htab = elf_x86_hash_table (info, bed->target_id); 2443 if (htab == NULL) 2444 return pbfd; 2445 2446 htab->r_info = init_table->r_info; 2447 htab->r_sym = init_table->r_sym; 2448 2449 if (bfd_link_relocatable (info)) 2450 return pbfd; 2451 2452 htab->plt0_pad_byte = init_table->plt0_pad_byte; 2453 2454 use_ibt_plt = info->ibtplt || info->ibt; 2455 if (!use_ibt_plt && pbfd != NULL) 2456 { 2457 /* Check if GNU_PROPERTY_X86_FEATURE_1_IBT is on. */ 2458 elf_property_list *p; 2459 2460 /* The property list is sorted in order of type. */ 2461 for (p = elf_properties (pbfd); p; p = p->next) 2462 { 2463 if (GNU_PROPERTY_X86_FEATURE_1_AND == p->property.pr_type) 2464 { 2465 use_ibt_plt = !!(p->property.u.number 2466 & GNU_PROPERTY_X86_FEATURE_1_IBT); 2467 break; 2468 } 2469 else if (GNU_PROPERTY_X86_FEATURE_1_AND < p->property.pr_type) 2470 break; 2471 } 2472 } 2473 2474 dynobj = htab->elf.dynobj; 2475 2476 /* Set htab->elf.dynobj here so that there is no need to check and 2477 set it in check_relocs. */ 2478 if (dynobj == NULL) 2479 { 2480 if (pbfd != NULL) 2481 { 2482 htab->elf.dynobj = pbfd; 2483 dynobj = pbfd; 2484 } 2485 else 2486 { 2487 bfd *abfd; 2488 2489 /* Find a normal input file to hold linker created 2490 sections. */ 2491 for (abfd = info->input_bfds; 2492 abfd != NULL; 2493 abfd = abfd->link.next) 2494 if (bfd_get_flavour (abfd) == bfd_target_elf_flavour 2495 && (abfd->flags 2496 & (DYNAMIC | BFD_LINKER_CREATED | BFD_PLUGIN)) == 0) 2497 { 2498 htab->elf.dynobj = abfd; 2499 dynobj = abfd; 2500 break; 2501 } 2502 } 2503 } 2504 2505 /* Return if there are no normal input files. */ 2506 if (dynobj == NULL) 2507 return pbfd; 2508 2509 /* Even when lazy binding is disabled by "-z now", the PLT0 entry may 2510 still be used with LD_AUDIT or LD_PROFILE if PLT entry is used for 2511 canonical function address. */ 2512 htab->plt.has_plt0 = 1; 2513 normal_target = htab->target_os == is_normal; 2514 2515 if (normal_target) 2516 { 2517 if (use_ibt_plt) 2518 { 2519 htab->lazy_plt = init_table->lazy_ibt_plt; 2520 htab->non_lazy_plt = init_table->non_lazy_ibt_plt; 2521 } 2522 else 2523 { 2524 htab->lazy_plt = init_table->lazy_plt; 2525 htab->non_lazy_plt = init_table->non_lazy_plt; 2526 } 2527 } 2528 else 2529 { 2530 htab->lazy_plt = init_table->lazy_plt; 2531 htab->non_lazy_plt = NULL; 2532 } 2533 2534 pltsec = htab->elf.splt; 2535 2536 /* If the non-lazy PLT is available, use it for all PLT entries if 2537 there are no PLT0 or no .plt section. */ 2538 if (htab->non_lazy_plt != NULL 2539 && (!htab->plt.has_plt0 || pltsec == NULL)) 2540 { 2541 lazy_plt = FALSE; 2542 if (bfd_link_pic (info)) 2543 htab->plt.plt_entry = htab->non_lazy_plt->pic_plt_entry; 2544 else 2545 htab->plt.plt_entry = htab->non_lazy_plt->plt_entry; 2546 htab->plt.plt_entry_size = htab->non_lazy_plt->plt_entry_size; 2547 htab->plt.plt_got_offset = htab->non_lazy_plt->plt_got_offset; 2548 htab->plt.plt_got_insn_size 2549 = htab->non_lazy_plt->plt_got_insn_size; 2550 htab->plt.eh_frame_plt_size 2551 = htab->non_lazy_plt->eh_frame_plt_size; 2552 htab->plt.eh_frame_plt = htab->non_lazy_plt->eh_frame_plt; 2553 } 2554 else 2555 { 2556 lazy_plt = TRUE; 2557 if (bfd_link_pic (info)) 2558 { 2559 htab->plt.plt0_entry = htab->lazy_plt->pic_plt0_entry; 2560 htab->plt.plt_entry = htab->lazy_plt->pic_plt_entry; 2561 } 2562 else 2563 { 2564 htab->plt.plt0_entry = htab->lazy_plt->plt0_entry; 2565 htab->plt.plt_entry = htab->lazy_plt->plt_entry; 2566 } 2567 htab->plt.plt_entry_size = htab->lazy_plt->plt_entry_size; 2568 htab->plt.plt_got_offset = htab->lazy_plt->plt_got_offset; 2569 htab->plt.plt_got_insn_size 2570 = htab->lazy_plt->plt_got_insn_size; 2571 htab->plt.eh_frame_plt_size 2572 = htab->lazy_plt->eh_frame_plt_size; 2573 htab->plt.eh_frame_plt = htab->lazy_plt->eh_frame_plt; 2574 } 2575 2576 if (htab->target_os == is_vxworks 2577 && !elf_vxworks_create_dynamic_sections (dynobj, info, 2578 &htab->srelplt2)) 2579 { 2580 info->callbacks->einfo (_("%F%P: failed to create VxWorks dynamic sections\n")); 2581 return pbfd; 2582 } 2583 2584 /* Since create_dynamic_sections isn't always called, but GOT 2585 relocations need GOT relocations, create them here so that we 2586 don't need to do it in check_relocs. */ 2587 if (htab->elf.sgot == NULL 2588 && !_bfd_elf_create_got_section (dynobj, info)) 2589 info->callbacks->einfo (_("%F%P: failed to create GOT sections\n")); 2590 2591 got_align = (bed->target_id == X86_64_ELF_DATA) ? 3 : 2; 2592 2593 /* Align .got and .got.plt sections to their entry size. Do it here 2594 instead of in create_dynamic_sections so that they are always 2595 properly aligned even if create_dynamic_sections isn't called. */ 2596 sec = htab->elf.sgot; 2597 if (!bfd_set_section_alignment (dynobj, sec, got_align)) 2598 goto error_alignment; 2599 2600 sec = htab->elf.sgotplt; 2601 if (!bfd_set_section_alignment (dynobj, sec, got_align)) 2602 goto error_alignment; 2603 2604 /* Create the ifunc sections here so that check_relocs can be 2605 simplified. */ 2606 if (!_bfd_elf_create_ifunc_sections (dynobj, info)) 2607 info->callbacks->einfo (_("%F%P: failed to create ifunc sections\n")); 2608 2609 plt_alignment = bfd_log2 (htab->plt.plt_entry_size); 2610 2611 if (pltsec != NULL) 2612 { 2613 /* Whe creating executable, set the contents of the .interp 2614 section to the interpreter. */ 2615 if (bfd_link_executable (info) && !info->nointerp) 2616 { 2617 asection *s = bfd_get_linker_section (dynobj, ".interp"); 2618 if (s == NULL) 2619 abort (); 2620 s->size = htab->dynamic_interpreter_size; 2621 s->contents = (unsigned char *) htab->dynamic_interpreter; 2622 htab->interp = s; 2623 } 2624 2625 /* Don't change PLT section alignment for NaCl since it uses 2626 64-byte PLT entry and sets PLT section alignment to 32 2627 bytes. Don't create additional PLT sections for NaCl. */ 2628 if (normal_target) 2629 { 2630 flagword pltflags = (bed->dynamic_sec_flags 2631 | SEC_ALLOC 2632 | SEC_CODE 2633 | SEC_LOAD 2634 | SEC_READONLY); 2635 unsigned int non_lazy_plt_alignment 2636 = bfd_log2 (htab->non_lazy_plt->plt_entry_size); 2637 2638 sec = pltsec; 2639 if (!bfd_set_section_alignment (sec->owner, sec, 2640 plt_alignment)) 2641 goto error_alignment; 2642 2643 /* Create the GOT procedure linkage table. */ 2644 sec = bfd_make_section_anyway_with_flags (dynobj, 2645 ".plt.got", 2646 pltflags); 2647 if (sec == NULL) 2648 info->callbacks->einfo (_("%F%P: failed to create GOT PLT section\n")); 2649 2650 if (!bfd_set_section_alignment (dynobj, sec, 2651 non_lazy_plt_alignment)) 2652 goto error_alignment; 2653 2654 htab->plt_got = sec; 2655 2656 if (lazy_plt) 2657 { 2658 sec = NULL; 2659 2660 if (use_ibt_plt) 2661 { 2662 /* Create the second PLT for Intel IBT support. IBT 2663 PLT is supported only for non-NaCl target and is 2664 is needed only for lazy binding. */ 2665 sec = bfd_make_section_anyway_with_flags (dynobj, 2666 ".plt.sec", 2667 pltflags); 2668 if (sec == NULL) 2669 info->callbacks->einfo (_("%F%P: failed to create IBT-enabled PLT section\n")); 2670 2671 if (!bfd_set_section_alignment (dynobj, sec, 2672 plt_alignment)) 2673 goto error_alignment; 2674 } 2675 else if (info->bndplt && ABI_64_P (dynobj)) 2676 { 2677 /* Create the second PLT for Intel MPX support. MPX 2678 PLT is supported only for non-NaCl target in 64-bit 2679 mode and is needed only for lazy binding. */ 2680 sec = bfd_make_section_anyway_with_flags (dynobj, 2681 ".plt.sec", 2682 pltflags); 2683 if (sec == NULL) 2684 info->callbacks->einfo (_("%F%P: failed to create BND PLT section\n")); 2685 2686 if (!bfd_set_section_alignment (dynobj, sec, 2687 non_lazy_plt_alignment)) 2688 goto error_alignment; 2689 } 2690 2691 htab->plt_second = sec; 2692 } 2693 } 2694 2695 if (!info->no_ld_generated_unwind_info) 2696 { 2697 flagword flags = (SEC_ALLOC | SEC_LOAD | SEC_READONLY 2698 | SEC_HAS_CONTENTS | SEC_IN_MEMORY 2699 | SEC_LINKER_CREATED); 2700 2701 sec = bfd_make_section_anyway_with_flags (dynobj, 2702 ".eh_frame", 2703 flags); 2704 if (sec == NULL) 2705 info->callbacks->einfo (_("%F%P: failed to create PLT .eh_frame section\n")); 2706 2707 if (!bfd_set_section_alignment (dynobj, sec, class_align)) 2708 goto error_alignment; 2709 2710 htab->plt_eh_frame = sec; 2711 2712 if (htab->plt_got != NULL) 2713 { 2714 sec = bfd_make_section_anyway_with_flags (dynobj, 2715 ".eh_frame", 2716 flags); 2717 if (sec == NULL) 2718 info->callbacks->einfo (_("%F%P: failed to create GOT PLT .eh_frame section\n")); 2719 2720 if (!bfd_set_section_alignment (dynobj, sec, class_align)) 2721 goto error_alignment; 2722 2723 htab->plt_got_eh_frame = sec; 2724 } 2725 2726 if (htab->plt_second != NULL) 2727 { 2728 sec = bfd_make_section_anyway_with_flags (dynobj, 2729 ".eh_frame", 2730 flags); 2731 if (sec == NULL) 2732 info->callbacks->einfo (_("%F%P: failed to create the second PLT .eh_frame section\n")); 2733 2734 if (!bfd_set_section_alignment (dynobj, sec, class_align)) 2735 goto error_alignment; 2736 2737 htab->plt_second_eh_frame = sec; 2738 } 2739 } 2740 } 2741 2742 if (normal_target) 2743 { 2744 /* The .iplt section is used for IFUNC symbols in static 2745 executables. */ 2746 sec = htab->elf.iplt; 2747 if (sec != NULL 2748 && !bfd_set_section_alignment (sec->owner, sec, 2749 plt_alignment)) 2750 goto error_alignment; 2751 } 2752 2753 return pbfd; 2754 } 2755