bfd/elfxx-x86.h

   1 /* x86 specific support for ELF
   2    Copyright (C) 2017 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 "sysdep.h"
  22 #include "bfd.h"
  23 #include "bfdlink.h"
  24 #include "libbfd.h"
  25 #include "elf-bfd.h"
  26 #include "bfd_stdint.h"
  27 #include "hashtab.h"
  28
  29 #define PLT_CIE_LENGTH          20
  30 #define PLT_FDE_LENGTH          36
  31 #define PLT_FDE_START_OFFSET    4 + PLT_CIE_LENGTH + 8
  32 #define PLT_FDE_LEN_OFFSET      4 + PLT_CIE_LENGTH + 12
  33
  34 #define ABI_64_P(abfd) \
  35   (get_elf_backend_data (abfd)->s->elfclass == ELFCLASS64)
  36
  37 /* If ELIMINATE_COPY_RELOCS is non-zero, the linker will try to avoid
  38    copying dynamic variables from a shared lib into an app's dynbss
  39    section, and instead use a dynamic relocation to point into the
  40    shared lib.  */
  41 #define ELIMINATE_COPY_RELOCS 1
  42
  43 #define elf_x86_hash_table(p, id) \
  44   (is_elf_hash_table ((p)->hash) \
  45    && elf_hash_table_id ((struct elf_link_hash_table *) ((p)->hash)) == (id) \
  46     ? ((struct elf_x86_link_hash_table *) ((p)->hash)) : NULL)
  47
  48 /* Will references to this symbol always be local in this object?  */
  49 #define SYMBOL_REFERENCES_LOCAL_P(INFO, H) \
  50   _bfd_x86_elf_link_symbol_references_local ((INFO), (H))
  51
  52 /* Is a undefined weak symbol which is resolved to 0.  Reference to an
  53    undefined weak symbol is resolved to 0 when building executable if
  54    it isn't dynamic and
  55    1. Has non-GOT/non-PLT relocations in text section.  Or
  56    2. Has no GOT/PLT relocation.
  57    Local undefined weak symbol is always resolved to 0.
  58  */
  59 #define UNDEFINED_WEAK_RESOLVED_TO_ZERO(INFO, EH) \
  60   ((EH)->elf.root.type == bfd_link_hash_undefweak                \
  61    && (SYMBOL_REFERENCES_LOCAL_P ((INFO), &(EH)->elf)            \
  62        || (bfd_link_executable (INFO)                            \
  63            && (!(EH)->has_got_reloc                              \
  64                || (EH)->has_non_got_reloc))))
  65
  66 /* Should copy relocation be generated for a symbol.  Don't generate
  67    copy relocation against a protected symbol defined in a shared
  68    object with GNU_PROPERTY_NO_COPY_ON_PROTECTED.  */
  69 #define SYMBOL_NO_COPYRELOC(INFO, EH) \
  70   ((EH)->def_protected \
  71    && ((EH)->elf.root.type == bfd_link_hash_defined \
  72        || (EH)->elf.root.type == bfd_link_hash_defweak) \
  73    && elf_has_no_copy_on_protected ((EH)->elf.root.u.def.section->owner) \
  74    && ((EH)->elf.root.u.def.section->owner->flags & DYNAMIC) != 0 \
  75    && ((EH)->elf.root.u.def.section->flags & SEC_CODE) == 0)
  76
  77 /* TRUE if dynamic relocation is needed.  If we are creating a shared
  78    library, and this is a reloc against a global symbol, or a non PC
  79    relative reloc against a local symbol, then we need to copy the reloc
  80    into the shared library.  However, if we are linking with -Bsymbolic,
  81    we do not need to copy a reloc against a global symbol which is
  82    defined in an object we are including in the link (i.e., DEF_REGULAR
  83    is set).  At this point we have not seen all the input files, so it
  84    is possible that DEF_REGULAR is not set now but will be set later (it
  85    is never cleared).  In case of a weak definition, DEF_REGULAR may be
  86    cleared later by a strong definition in a shared library.  We account
  87    for that possibility below by storing information in the relocs_copied
  88    field of the hash table entry.  A similar situation occurs when
  89    creating shared libraries and symbol visibility changes render the
  90    symbol local.
  91
  92    If on the other hand, we are creating an executable, we may need to
  93    keep relocations for symbols satisfied by a dynamic library if we
  94    manage to avoid copy relocs for the symbol.
  95
  96    We also need to generate dynamic pointer relocation against
  97    STT_GNU_IFUNC symbol in the non-code section.  */
  98 #define NEED_DYNAMIC_RELOCATION_P(INFO, H, SEC, R_TYPE, POINTER_TYPE) \
  99   ((bfd_link_pic (INFO) \
 100     && (! X86_PCREL_TYPE_P (R_TYPE) \
 101         || ((H) != NULL \
 102             && (! (bfd_link_pie (INFO) \
 103                    || SYMBOLIC_BIND ((INFO), (H))) \
 104                 || (H)->root.type == bfd_link_hash_defweak \
 105                 || !(H)->def_regular)))) \
 106                 || ((H) != NULL \
 107                     && (H)->type == STT_GNU_IFUNC \
 108                     && (R_TYPE) == POINTER_TYPE \
 109                     && ((SEC)->flags & SEC_CODE) == 0) \
 110                     || (ELIMINATE_COPY_RELOCS \
 111                         && !bfd_link_pic (INFO) \
 112                         && (H) != NULL \
 113                         && ((H)->root.type == bfd_link_hash_defweak \
 114                             || !(H)->def_regular)))
 115
 116 /* TRUE if this is actually a static link, or it is a -Bsymbolic link
 117    and the symbol is defined locally, or the symbol was forced to be
 118    local because of a version file.  */
 119 #define RESOLVED_LOCALLY_P(INFO, H, HTAB) \
 120   (!WILL_CALL_FINISH_DYNAMIC_SYMBOL ((HTAB)->elf.dynamic_sections_created, \
 121                                      bfd_link_pic (INFO), (H)) \
 122    || (bfd_link_pic (INFO) \
 123        && SYMBOL_REFERENCES_LOCAL_P ((INFO), (H))) \
 124        || (ELF_ST_VISIBILITY ((H)->other) \
 125            && (H)->root.type == bfd_link_hash_undefweak))
 126
 127 /* TRUE if relative relocation should be generated.  GOT reference to
 128    global symbol in PIC will lead to dynamic symbol.  It becomes a
 129    problem when "time" or "times" is defined as a variable in an
 130    executable, clashing with functions of the same name in libc.  If a
 131    symbol isn't undefined weak symbol, don't make it dynamic in PIC and
 132    generate relative relocation.  */
 133 #define GENERATE_RELATIVE_RELOC_P(INFO, H) \
 134   ((H)->dynindx == -1 \
 135    && !(H)->forced_local \
 136    && (H)->root.type != bfd_link_hash_undefweak \
 137    && bfd_link_pic (INFO))
 138
 139 /* TRUE if this is a pointer reference to a local IFUNC.  */
 140 #define POINTER_LOCAL_IFUNC_P(INFO, H) \
 141   ((H)->dynindx == -1 \
 142    || (H)->forced_local \
 143    || bfd_link_executable (INFO))
 144
 145 /* TRUE if this is a PLT reference to a local IFUNC.  */
 146 #define PLT_LOCAL_IFUNC_P(INFO, H) \
 147   ((H)->dynindx == -1 \
 148    || ((bfd_link_executable (INFO) \
 149         || ELF_ST_VISIBILITY ((H)->other) != STV_DEFAULT) \
 150         && (H)->def_regular \
 151         && (H)->type == STT_GNU_IFUNC))
 152
 153 /* TRUE if TLS IE->LE transition is OK.  */
 154 #define TLS_TRANSITION_IE_TO_LE_P(INFO, H, TLS_TYPE) \
 155   (bfd_link_executable (INFO) \
 156    && (H) != NULL \
 157    && (H)->dynindx == -1 \
 158    && (TLS_TYPE & GOT_TLS_IE))
 159
 160 /* x86 ELF linker hash entry.  */
 161
 162 struct elf_x86_link_hash_entry
 163 {
 164   struct elf_link_hash_entry elf;
 165
 166   /* Track dynamic relocs copied for this symbol.  */
 167   struct elf_dyn_relocs *dyn_relocs;
 168
 169   unsigned char tls_type;
 170
 171   /* TRUE if symbol has GOT or PLT relocations.  */
 172   unsigned int has_got_reloc : 1;
 173
 174   /* TRUE if symbol has non-GOT/non-PLT relocations in text sections.  */
 175   unsigned int has_non_got_reloc : 1;
 176
 177   /* Don't call finish_dynamic_symbol on this symbol.  */
 178   unsigned int no_finish_dynamic_symbol : 1;
 179
 180   /* TRUE if symbol is __tls_get_addr.  */
 181   unsigned int tls_get_addr : 1;
 182
 183   /* TRUE if symbol is defined as a protected symbol.  */
 184   unsigned int def_protected : 1;
 185
 186   /* 0: Symbol references are unknown.
 187      1: Symbol references aren't local.
 188      2: Symbol references are local.
 189    */
 190   unsigned int local_ref : 2;
 191
 192   /* TRUE if symbol is defined by linker.  */
 193   unsigned int linker_def : 1;
 194
 195   /* TRUE if symbol is referenced by R_386_GOTOFF relocation.  This is
 196      only used by i386.  */
 197   unsigned int gotoff_ref : 1;
 198
 199   /* TRUE if a weak symbol with a real definition needs a copy reloc.
 200      When there is a weak symbol with a real definition, the processor
 201      independent code will have arranged for us to see the real
 202      definition first.  We need to copy the needs_copy bit from the
 203      real definition and check it when allowing copy reloc in PIE.  This
 204      is only used by x86-64.  */
 205   unsigned int needs_copy : 1;
 206
 207   /* Reference count of C/C++ function pointer relocations in read-write
 208      section which can be resolved at run-time.  */
 209   bfd_signed_vma func_pointer_refcount;
 210
 211   /* Information about the GOT PLT entry. Filled when there are both
 212      GOT and PLT relocations against the same function.  */
 213   union gotplt_union plt_got;
 214
 215   /* Information about the second PLT entry.   */
 216   union gotplt_union plt_second;
 217
 218   /* Offset of the GOTPLT entry reserved for the TLS descriptor,
 219      starting at the end of the jump table.  */
 220   bfd_vma tlsdesc_got;
 221 };
 222
 223 struct elf_x86_lazy_plt_layout
 224 {
 225   /* The first entry in an absolute lazy procedure linkage table looks
 226      like this.  */
 227   const bfd_byte *plt0_entry;
 228   unsigned int plt0_entry_size;          /* Size of PLT0 entry.  */
 229
 230   /* Later entries in an absolute lazy procedure linkage table look
 231      like this.  */
 232   const bfd_byte *plt_entry;
 233   unsigned int plt_entry_size;          /* Size of each PLT entry.  */
 234
 235   /* Offsets into plt0_entry that are to be replaced with GOT[1] and
 236      GOT[2].  */
 237   unsigned int plt0_got1_offset;
 238   unsigned int plt0_got2_offset;
 239
 240   /* Offset of the end of the PC-relative instruction containing
 241      plt0_got2_offset.  This is for x86-64 only.  */
 242   unsigned int plt0_got2_insn_end;
 243
 244   /* Offsets into plt_entry that are to be replaced with...  */
 245   unsigned int plt_got_offset;    /* ... address of this symbol in .got. */
 246   unsigned int plt_reloc_offset;  /* ... offset into relocation table. */
 247   unsigned int plt_plt_offset;    /* ... offset to start of .plt. */
 248
 249   /* Length of the PC-relative instruction containing plt_got_offset.
 250      This is used for x86-64 only.  */
 251   unsigned int plt_got_insn_size;
 252
 253   /* Offset of the end of the PC-relative jump to plt0_entry.  This is
 254      used for x86-64 only.  */
 255   unsigned int plt_plt_insn_end;
 256
 257   /* Offset into plt_entry where the initial value of the GOT entry
 258      points.  */
 259   unsigned int plt_lazy_offset;
 260
 261   /* The first entry in a PIC lazy procedure linkage table looks like
 262      this.  */
 263   const bfd_byte *pic_plt0_entry;
 264
 265   /* Subsequent entries in a PIC lazy procedure linkage table look
 266      like this.  */
 267   const bfd_byte *pic_plt_entry;
 268
 269   /* .eh_frame covering the lazy .plt section.  */
 270   const bfd_byte *eh_frame_plt;
 271   unsigned int eh_frame_plt_size;
 272 };
 273
 274 struct elf_x86_non_lazy_plt_layout
 275 {
 276   /* Entries in an absolute non-lazy procedure linkage table look like
 277      this.  */
 278   const bfd_byte *plt_entry;
 279   /* Entries in a PIC non-lazy procedure linkage table look like this.  */
 280   const bfd_byte *pic_plt_entry;
 281
 282   unsigned int plt_entry_size;          /* Size of each PLT entry.  */
 283
 284   /* Offsets into plt_entry that are to be replaced with...  */
 285   unsigned int plt_got_offset;    /* ... address of this symbol in .got. */
 286
 287   /* Length of the PC-relative instruction containing plt_got_offset.
 288      This is used for x86-64 only.  */
 289   unsigned int plt_got_insn_size;
 290
 291   /* .eh_frame covering the non-lazy .plt section.  */
 292   const bfd_byte *eh_frame_plt;
 293   unsigned int eh_frame_plt_size;
 294 };
 295
 296 struct elf_x86_plt_layout
 297 {
 298   /* The first entry in a lazy procedure linkage table looks like this.
 299      This is only used for i386 where absolute PLT0 and PIC PLT0 are
 300      different.  */
 301   const bfd_byte *plt0_entry;
 302   /* Entries in a procedure linkage table look like this.  */
 303   const bfd_byte *plt_entry;
 304   unsigned int plt_entry_size;          /* Size of each PLT entry.  */
 305
 306   /* 1 has PLT0.  */
 307   unsigned int has_plt0;
 308
 309   /* Offsets into plt_entry that are to be replaced with...  */
 310   unsigned int plt_got_offset;    /* ... address of this symbol in .got. */
 311
 312   /* Length of the PC-relative instruction containing plt_got_offset.
 313      This is only used for x86-64.  */
 314   unsigned int plt_got_insn_size;
 315
 316   /* .eh_frame covering the .plt section.  */
 317   const bfd_byte *eh_frame_plt;
 318   unsigned int eh_frame_plt_size;
 319 };
 320
 321 /* Values in tls_type of x86 ELF linker hash entry.  */
 322 #define GOT_UNKNOWN     0
 323 #define GOT_NORMAL      1
 324 #define GOT_TLS_GD      2
 325 #define GOT_TLS_IE      4
 326 #define GOT_TLS_IE_POS  5
 327 #define GOT_TLS_IE_NEG  6
 328 #define GOT_TLS_IE_BOTH 7
 329 #define GOT_TLS_GDESC   8
 330 #define GOT_TLS_GD_BOTH_P(type) \
 331   ((type) == (GOT_TLS_GD | GOT_TLS_GDESC))
 332 #define GOT_TLS_GD_P(type) \
 333   ((type) == GOT_TLS_GD || GOT_TLS_GD_BOTH_P (type))
 334 #define GOT_TLS_GDESC_P(type) \
 335   ((type) == GOT_TLS_GDESC || GOT_TLS_GD_BOTH_P (type))
 336 #define GOT_TLS_GD_ANY_P(type) \
 337   (GOT_TLS_GD_P (type) || GOT_TLS_GDESC_P (type))
 338
 339 #define elf_x86_hash_entry(ent) \
 340   ((struct elf_x86_link_hash_entry *)(ent))
 341
 342 /* x86 ELF linker hash table.  */
 343
 344 struct elf_x86_link_hash_table
 345 {
 346   struct elf_link_hash_table elf;
 347
 348   /* Short-cuts to get to dynamic linker sections.  */
 349   asection *interp;
 350   asection *plt_eh_frame;
 351   asection *plt_second;
 352   asection *plt_second_eh_frame;
 353   asection *plt_got;
 354   asection *plt_got_eh_frame;
 355
 356   /* Parameters describing PLT generation, lazy or non-lazy.  */
 357   struct elf_x86_plt_layout plt;
 358
 359   /* Parameters describing lazy PLT generation.  */
 360   const struct elf_x86_lazy_plt_layout *lazy_plt;
 361
 362   /* Parameters describing non-lazy PLT generation.  */
 363   const struct elf_x86_non_lazy_plt_layout *non_lazy_plt;
 364
 365   union
 366   {
 367     bfd_signed_vma refcount;
 368     bfd_vma offset;
 369   } tls_ld_or_ldm_got;
 370
 371   /* The amount of space used by the jump slots in the GOT.  */
 372   bfd_vma sgotplt_jump_table_size;
 373
 374   /* Small local sym cache.  */
 375   struct sym_cache sym_cache;
 376
 377   /* _TLS_MODULE_BASE_ symbol.  */
 378   struct bfd_link_hash_entry *tls_module_base;
 379
 380   /* Used by local STT_GNU_IFUNC symbols.  */
 381   htab_t loc_hash_table;
 382   void * loc_hash_memory;
 383
 384   /* The offset into sgot of the GOT entry used by the PLT entry
 385      above.  */
 386   bfd_vma tlsdesc_got;
 387
 388   /* The index of the next R_X86_64_JUMP_SLOT entry in .rela.plt.  */
 389   bfd_vma next_jump_slot_index;
 390   /* The index of the next R_X86_64_IRELATIVE entry in .rela.plt.  */
 391   bfd_vma next_irelative_index;
 392
 393   /* TRUE if there are dynamic relocs against IFUNC symbols that apply
 394      to read-only sections.  */
 395   bfd_boolean readonly_dynrelocs_against_ifunc;
 396
 397   /* TRUE if this is a VxWorks x86 target.  This is only used for
 398      i386.  */
 399   bfd_boolean is_vxworks;
 400
 401   /* The (unloaded but important) .rel.plt.unloaded section on VxWorks.
 402      This is used for i386 only.  */
 403   asection *srelplt2;
 404
 405   /* The index of the next unused R_386_TLS_DESC slot in .rel.plt.  This
 406      is only used for i386.  */
 407   bfd_vma next_tls_desc_index;
 408
 409   /* The offset into splt of the PLT entry for the TLS descriptor
 410      resolver.  Special values are 0, if not necessary (or not found
 411      to be necessary yet), and -1 if needed but not determined
 412      yet.  This is only used for x86-64.  */
 413   bfd_vma tlsdesc_plt;
 414
 415   bfd_vma (*r_info) (bfd_vma, bfd_vma);
 416   bfd_vma (*r_sym) (bfd_vma);
 417   bfd_boolean (*is_reloc_section) (const char *);
 418   enum elf_target_id target_id;
 419   unsigned int sizeof_reloc;
 420   unsigned int dt_reloc;
 421   unsigned int dt_reloc_sz;
 422   unsigned int dt_reloc_ent;
 423   unsigned int got_entry_size;
 424   unsigned int pointer_r_type;
 425   int dynamic_interpreter_size;
 426   const char *dynamic_interpreter;
 427   const char *tls_get_addr;
 428 };
 429
 430 struct elf_x86_init_table
 431 {
 432   /* The lazy PLT layout.  */
 433   const struct elf_x86_lazy_plt_layout *lazy_plt;
 434
 435   /* The non-lazy PLT layout.  */
 436   const struct elf_x86_non_lazy_plt_layout *non_lazy_plt;
 437
 438   /* The lazy PLT layout for IBT.  */
 439   const struct elf_x86_lazy_plt_layout *lazy_ibt_plt;
 440
 441   /* The non-lazy PLT layout for IBT.  */
 442   const struct elf_x86_non_lazy_plt_layout *non_lazy_ibt_plt;
 443
 444   /* TRUE if this is a normal x86 target.  */
 445   bfd_boolean normal_target;
 446
 447   /* TRUE if this is a VxWorks x86 target.  */
 448   bfd_boolean is_vxworks;
 449
 450   bfd_vma (*r_info) (bfd_vma, bfd_vma);
 451   bfd_vma (*r_sym) (bfd_vma);
 452 };
 453
 454 struct elf_x86_obj_tdata
 455 {
 456   struct elf_obj_tdata root;
 457
 458   /* tls_type for each local got entry.  */
 459   char *local_got_tls_type;
 460
 461   /* GOTPLT entries for TLS descriptors.  */
 462   bfd_vma *local_tlsdesc_gotent;
 463 };
 464
 465 enum elf_x86_plt_type
 466 {
 467   plt_non_lazy = 0,
 468   plt_lazy = 1 << 0,
 469   plt_pic = 1 << 1,
 470   plt_second = 1 << 2,
 471   plt_unknown = -1
 472 };
 473
 474 struct elf_x86_plt
 475 {
 476   const char *name;
 477   asection *sec;
 478   bfd_byte *contents;
 479   enum elf_x86_plt_type type;
 480   unsigned int plt_got_offset;
 481   unsigned int plt_entry_size;
 482   unsigned int plt_got_insn_size;       /* Only used for x86-64.  */
 483   long count;
 484 };
 485
 486 #define elf_x86_tdata(abfd) \
 487   ((struct elf_x86_obj_tdata *) (abfd)->tdata.any)
 488
 489 #define elf_x86_local_got_tls_type(abfd) \
 490   (elf_x86_tdata (abfd)->local_got_tls_type)
 491
 492 #define elf_x86_local_tlsdesc_gotent(abfd) \
 493   (elf_x86_tdata (abfd)->local_tlsdesc_gotent)
 494
 495 #define elf_x86_compute_jump_table_size(htab) \
 496   ((htab)->elf.srelplt->reloc_count * (htab)->got_entry_size)
 497
 498 #define is_x86_elf(bfd, htab)                           \
 499   (bfd_get_flavour (bfd) == bfd_target_elf_flavour      \
 500    && elf_tdata (bfd) != NULL                           \
 501    && elf_object_id (bfd) == (htab)->target_id)
 502
 503 extern bfd_boolean _bfd_x86_elf_mkobject
 504   (bfd *);
 505
 506 extern void _bfd_x86_elf_set_tls_module_base
 507   (struct bfd_link_info *);
 508
 509 extern bfd_vma _bfd_x86_elf_dtpoff_base
 510   (struct bfd_link_info *);
 511
 512 extern bfd_boolean _bfd_x86_elf_readonly_dynrelocs
 513   (struct elf_link_hash_entry *, void *);
 514
 515 extern struct elf_link_hash_entry * _bfd_elf_x86_get_local_sym_hash
 516   (struct elf_x86_link_hash_table *, bfd *, const Elf_Internal_Rela *,
 517    bfd_boolean);
 518
 519 extern hashval_t _bfd_x86_elf_local_htab_hash
 520   (const void *);
 521
 522 extern int _bfd_x86_elf_local_htab_eq
 523   (const void *, const void *);
 524
 525 extern struct bfd_hash_entry * _bfd_x86_elf_link_hash_newfunc
 526   (struct bfd_hash_entry *, struct bfd_hash_table *, const char *);
 527
 528 extern struct bfd_link_hash_table * _bfd_x86_elf_link_hash_table_create
 529   (bfd *);
 530
 531 extern int _bfd_x86_elf_compare_relocs
 532   (const void *, const void *);
 533
 534 extern bfd_boolean _bfd_x86_elf_link_check_relocs
 535   (bfd *, struct bfd_link_info *);
 536
 537 extern bfd_boolean _bfd_x86_elf_size_dynamic_sections
 538   (bfd *, struct bfd_link_info *);
 539
 540 extern bfd_boolean _bfd_x86_elf_always_size_sections
 541   (bfd *, struct bfd_link_info *);
 542
 543 extern void _bfd_x86_elf_merge_symbol_attribute
 544   (struct elf_link_hash_entry *, const Elf_Internal_Sym *,
 545    bfd_boolean, bfd_boolean);
 546
 547 extern void _bfd_x86_elf_copy_indirect_symbol
 548   (struct bfd_link_info *, struct elf_link_hash_entry *,
 549    struct elf_link_hash_entry *);
 550
 551 extern bfd_boolean _bfd_x86_elf_fixup_symbol
 552   (struct bfd_link_info *, struct elf_link_hash_entry *);
 553
 554 extern bfd_boolean _bfd_x86_elf_hash_symbol
 555   (struct elf_link_hash_entry *);
 556
 557 extern bfd_boolean _bfd_x86_elf_adjust_dynamic_symbol
 558   (struct bfd_link_info *, struct elf_link_hash_entry *);
 559
 560 extern bfd_boolean _bfd_x86_elf_link_symbol_references_local
 561   (struct bfd_link_info *, struct elf_link_hash_entry *);
 562
 563 extern asection * _bfd_x86_elf_gc_mark_hook
 564   (asection *, struct bfd_link_info *, Elf_Internal_Rela *,
 565    struct elf_link_hash_entry *, Elf_Internal_Sym *);
 566
 567 extern long _bfd_x86_elf_get_synthetic_symtab
 568   (bfd *, long, long, bfd_vma, struct elf_x86_plt [], asymbol **,
 569    asymbol **);
 570
 571 extern enum elf_property_kind _bfd_x86_elf_parse_gnu_properties
 572   (bfd *, unsigned int, bfd_byte *, unsigned int);
 573
 574 extern bfd_boolean _bfd_x86_elf_merge_gnu_properties
 575   (struct bfd_link_info *, bfd *, elf_property *, elf_property *);
 576
 577 extern bfd * _bfd_x86_elf_link_setup_gnu_properties
 578   (struct bfd_link_info *, struct elf_x86_init_table *);
 579
 580 #define bfd_elf64_mkobject \
 581   _bfd_x86_elf_mkobject
 582 #define bfd_elf32_mkobject \
 583   _bfd_x86_elf_mkobject
 584 #define bfd_elf64_bfd_link_hash_table_create \
 585   _bfd_x86_elf_link_hash_table_create
 586 #define bfd_elf32_bfd_link_hash_table_create \
 587   _bfd_x86_elf_link_hash_table_create
 588 #define bfd_elf64_bfd_link_check_relocs \
 589   _bfd_x86_elf_link_check_relocs
 590 #define bfd_elf32_bfd_link_check_relocs \
 591   _bfd_x86_elf_link_check_relocs
 592
 593 #define elf_backend_size_dynamic_sections \
 594   _bfd_x86_elf_size_dynamic_sections
 595 #define elf_backend_always_size_sections \
 596   _bfd_x86_elf_always_size_sections
 597 #define elf_backend_merge_symbol_attribute \
 598   _bfd_x86_elf_merge_symbol_attribute
 599 #define elf_backend_copy_indirect_symbol \
 600   _bfd_x86_elf_copy_indirect_symbol
 601 #define elf_backend_fixup_symbol \
 602   _bfd_x86_elf_fixup_symbol
 603 #define elf_backend_hash_symbol \
 604   _bfd_x86_elf_hash_symbol
 605 #define elf_backend_adjust_dynamic_symbol \
 606   _bfd_x86_elf_adjust_dynamic_symbol
 607 #define elf_backend_gc_mark_hook \
 608   _bfd_x86_elf_gc_mark_hook
 609 #define elf_backend_omit_section_dynsym \
 610   ((bfd_boolean (*) (bfd *, struct bfd_link_info *, asection *)) bfd_true)
 611 #define elf_backend_parse_gnu_properties \
 612   _bfd_x86_elf_parse_gnu_properties
 613 #define elf_backend_merge_gnu_properties \
 614   _bfd_x86_elf_merge_gnu_properties