bfd/elfxx-x86.h

   1 /* x86 specific support for ELF
   2    Copyright (C) 2017-2019 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 "hashtab.h"
  27 #include "elf-linker-x86.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 /* TRUE if an undefined weak symbol should be resolved to 0.  Local
  53    undefined weak symbol is always resolved to 0.  Reference to an
  54    undefined weak symbol is resolved to 0 in executable if undefined
  55    weak symbol should be resolved to 0 (zero_undefweak > 0).  */
  56 #define UNDEFINED_WEAK_RESOLVED_TO_ZERO(INFO, EH) \
  57   ((EH)->elf.root.type == bfd_link_hash_undefweak                \
  58    && (SYMBOL_REFERENCES_LOCAL_P ((INFO), &(EH)->elf)            \
  59        || (bfd_link_executable (INFO)                            \
  60            && (EH)->zero_undefweak > 0)))
  61
  62 /* Should copy relocation be generated for a symbol.  Don't generate
  63    copy relocation against a protected symbol defined in a shared
  64    object with GNU_PROPERTY_NO_COPY_ON_PROTECTED.  */
  65 #define SYMBOL_NO_COPYRELOC(INFO, EH) \
  66   ((EH)->def_protected \
  67    && ((EH)->elf.root.type == bfd_link_hash_defined \
  68        || (EH)->elf.root.type == bfd_link_hash_defweak) \
  69    && elf_has_no_copy_on_protected ((EH)->elf.root.u.def.section->owner) \
  70    && ((EH)->elf.root.u.def.section->owner->flags & DYNAMIC) != 0 \
  71    && ((EH)->elf.root.u.def.section->flags & SEC_CODE) == 0)
  72
  73 /* TRUE if dynamic relocation is needed.  If we are creating a shared
  74    library, and this is a reloc against a global symbol, or a non PC
  75    relative reloc against a local symbol, then we need to copy the reloc
  76    into the shared library.  However, if we are linking with -Bsymbolic,
  77    we do not need to copy a reloc against a global symbol which is
  78    defined in an object we are including in the link (i.e., DEF_REGULAR
  79    is set).
  80
  81    If PCREL_PLT is true, don't generate dynamic relocation in PIE for
  82    PC-relative relocation against a dynamic function definition in data
  83    section when PLT address can be used.
  84
  85    If on the other hand, we are creating an executable, we may need to
  86    keep relocations for symbols satisfied by a dynamic library if we
  87    manage to avoid copy relocs for the symbol.
  88
  89    We also need to generate dynamic pointer relocation against
  90    STT_GNU_IFUNC symbol in the non-code section.  */
  91 #define NEED_DYNAMIC_RELOCATION_P(INFO, PCREL_PLT, H, SEC, R_TYPE, \
  92                                   POINTER_TYPE) \
  93   ((bfd_link_pic (INFO) \
  94     && (! X86_PCREL_TYPE_P (R_TYPE) \
  95         || ((H) != NULL \
  96             && (! (bfd_link_pie (INFO) \
  97                    || SYMBOLIC_BIND ((INFO), (H))) \
  98                 || (H)->root.type == bfd_link_hash_defweak \
  99                 || (!(bfd_link_pie (INFO) \
 100                       && (PCREL_PLT) \
 101                       && (H)->plt.refcount > 0 \
 102                       && ((SEC)->flags & SEC_CODE) == 0 \
 103                       && (H)->type == STT_FUNC \
 104                       && (H)->def_dynamic) \
 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 dynamic relocation should be generated.  Don't copy a
 117    pc-relative relocation into the output file if the symbol needs
 118    copy reloc or the symbol is undefined when building executable.
 119    Copy dynamic function pointer relocations.  Don't generate dynamic
 120    relocations against resolved undefined weak symbols in PIE, except
 121    when PC32_RELOC is TRUE.  Undefined weak symbol is bound locally
 122    when PIC is false.  */
 123 #define GENERATE_DYNAMIC_RELOCATION_P(INFO, EH, R_TYPE, \
 124                                       NEED_COPY_RELOC_IN_PIE, \
 125                                       RESOLVED_TO_ZERO, PC32_RELOC) \
 126   ((bfd_link_pic (INFO) \
 127     && !(NEED_COPY_RELOC_IN_PIE) \
 128     && ((EH) == NULL \
 129         || ((ELF_ST_VISIBILITY ((EH)->elf.other) == STV_DEFAULT \
 130              && (!(RESOLVED_TO_ZERO) || PC32_RELOC)) \
 131             || (EH)->elf.root.type != bfd_link_hash_undefweak)) \
 132     && ((!X86_PCREL_TYPE_P (R_TYPE) \
 133          && !X86_SIZE_TYPE_P (R_TYPE)) \
 134          || ! SYMBOL_CALLS_LOCAL ((INFO), &(EH)->elf))) \
 135    || (ELIMINATE_COPY_RELOCS \
 136        && !bfd_link_pic (INFO) \
 137        && (EH) != NULL \
 138        && (EH)->elf.dynindx != -1 \
 139        && (!(EH)->elf.non_got_ref \
 140            || ((EH)->elf.root.type == bfd_link_hash_undefweak \
 141                && !(RESOLVED_TO_ZERO))) \
 142                && (((EH)->elf.def_dynamic && !(EH)->elf.def_regular) \
 143                    || (EH)->elf.root.type == bfd_link_hash_undefined)))
 144
 145 /* TRUE if this input relocation should be copied to output.  H->dynindx
 146    may be -1 if this symbol was marked to become local.  */
 147 #define COPY_INPUT_RELOC_P(INFO, H, R_TYPE) \
 148   ((H) != NULL \
 149    && (H)->dynindx != -1 \
 150    && (X86_PCREL_TYPE_P (R_TYPE) \
 151        || !(bfd_link_executable (INFO) || SYMBOLIC_BIND ((INFO), (H))) \
 152        || !(H)->def_regular))
 153
 154 /* TRUE if this is actually a static link, or it is a -Bsymbolic link
 155    and the symbol is defined locally, or the symbol was forced to be
 156    local because of a version file.  */
 157 #define RESOLVED_LOCALLY_P(INFO, H, HTAB) \
 158   (!WILL_CALL_FINISH_DYNAMIC_SYMBOL ((HTAB)->elf.dynamic_sections_created, \
 159                                      bfd_link_pic (INFO), (H)) \
 160    || (bfd_link_pic (INFO) \
 161        && SYMBOL_REFERENCES_LOCAL_P ((INFO), (H))) \
 162        || (ELF_ST_VISIBILITY ((H)->other) \
 163            && (H)->root.type == bfd_link_hash_undefweak))
 164
 165 /* TRUE if this symbol isn't defined by a shared object.  */
 166 #define SYMBOL_DEFINED_NON_SHARED_P(H) \
 167   ((H)->def_regular \
 168    || (H)->root.linker_def \
 169    || (H)->root.ldscript_def \
 170    || ((struct elf_x86_link_hash_entry *) (H))->linker_def \
 171    || ELF_COMMON_DEF_P (H))
 172
 173 /* TRUE if relative relocation should be generated.  GOT reference to
 174    global symbol in PIC will lead to dynamic symbol.  It becomes a
 175    problem when "time" or "times" is defined as a variable in an
 176    executable, clashing with functions of the same name in libc.  If a
 177    symbol isn't undefined weak symbol, don't make it dynamic in PIC and
 178    generate relative relocation.  */
 179 #define GENERATE_RELATIVE_RELOC_P(INFO, H) \
 180   ((H)->dynindx == -1 \
 181    && !(H)->forced_local \
 182    && (H)->root.type != bfd_link_hash_undefweak \
 183    && bfd_link_pic (INFO))
 184
 185 /* TRUE if this is a pointer reference to a local IFUNC.  */
 186 #define POINTER_LOCAL_IFUNC_P(INFO, H) \
 187   ((H)->dynindx == -1 \
 188    || (H)->forced_local \
 189    || bfd_link_executable (INFO))
 190
 191 /* TRUE if this is a PLT reference to a local IFUNC.  */
 192 #define PLT_LOCAL_IFUNC_P(INFO, H) \
 193   ((H)->dynindx == -1 \
 194    || ((bfd_link_executable (INFO) \
 195         || ELF_ST_VISIBILITY ((H)->other) != STV_DEFAULT) \
 196         && (H)->def_regular \
 197         && (H)->type == STT_GNU_IFUNC))
 198
 199 /* TRUE if TLS IE->LE transition is OK.  */
 200 #define TLS_TRANSITION_IE_TO_LE_P(INFO, H, TLS_TYPE) \
 201   (bfd_link_executable (INFO) \
 202    && (H) != NULL \
 203    && (H)->dynindx == -1 \
 204    && (TLS_TYPE & GOT_TLS_IE))
 205
 206 /* Verify that the symbol has an entry in the procedure linkage table.  */
 207 #define VERIFY_PLT_ENTRY(INFO, H, PLT, GOTPLT, RELPLT, LOCAL_UNDEFWEAK) \
 208   do \
 209     { \
 210       if (((H)->dynindx == -1 \
 211            && !LOCAL_UNDEFWEAK \
 212            && !(((H)->forced_local || bfd_link_executable (INFO)) \
 213                 && (H)->def_regular \
 214                 && (H)->type == STT_GNU_IFUNC)) \
 215           || (PLT) == NULL \
 216           || (GOTPLT) == NULL \
 217           || (RELPLT) == NULL) \
 218         abort (); \
 219     } \
 220   while (0);
 221
 222 /* Verify that the symbol supports copy relocation.  */
 223 #define VERIFY_COPY_RELOC(H, HTAB) \
 224   do \
 225     { \
 226       if ((H)->dynindx == -1 \
 227           || ((H)->root.type != bfd_link_hash_defined \
 228               && (H)->root.type != bfd_link_hash_defweak) \
 229           || (HTAB)->elf.srelbss == NULL \
 230           || (HTAB)->elf.sreldynrelro == NULL) \
 231         abort (); \
 232     } \
 233   while (0);
 234
 235 /* x86 ELF linker hash entry.  */
 236
 237 struct elf_x86_link_hash_entry
 238 {
 239   struct elf_link_hash_entry elf;
 240
 241   /* Track dynamic relocs copied for this symbol.  */
 242   struct elf_dyn_relocs *dyn_relocs;
 243
 244   unsigned char tls_type;
 245
 246   /* Bit 0: Symbol has no GOT nor PLT relocations.
 247      Bit 1: Symbol has non-GOT/non-PLT relocations in text sections.
 248      zero_undefweak is initialized to 1 and undefined weak symbol
 249      should be resolved to 0 if zero_undefweak > 0.  */
 250   unsigned int zero_undefweak : 2;
 251
 252   /* Don't call finish_dynamic_symbol on this symbol.  */
 253   unsigned int no_finish_dynamic_symbol : 1;
 254
 255   /* TRUE if symbol is __tls_get_addr.  */
 256   unsigned int tls_get_addr : 1;
 257
 258   /* TRUE if symbol is defined as a protected symbol.  */
 259   unsigned int def_protected : 1;
 260
 261   /* 0: Symbol references are unknown.
 262      1: Symbol references aren't local.
 263      2: Symbol references are local.
 264    */
 265   unsigned int local_ref : 2;
 266
 267   /* TRUE if symbol is defined by linker.  */
 268   unsigned int linker_def : 1;
 269
 270   /* TRUE if symbol is referenced by R_386_GOTOFF relocation.  This is
 271      only used by i386.  */
 272   unsigned int gotoff_ref : 1;
 273
 274   /* TRUE if a weak symbol with a real definition needs a copy reloc.
 275      When there is a weak symbol with a real definition, the processor
 276      independent code will have arranged for us to see the real
 277      definition first.  We need to copy the needs_copy bit from the
 278      real definition and check it when allowing copy reloc in PIE.  This
 279      is only used by x86-64.  */
 280   unsigned int needs_copy : 1;
 281
 282   /* Information about the GOT PLT entry. Filled when there are both
 283      GOT and PLT relocations against the same function.  */
 284   union gotplt_union plt_got;
 285
 286   /* Information about the second PLT entry.   */
 287   union gotplt_union plt_second;
 288
 289   /* Offset of the GOTPLT entry reserved for the TLS descriptor,
 290      starting at the end of the jump table.  */
 291   bfd_vma tlsdesc_got;
 292 };
 293
 294 struct elf_x86_lazy_plt_layout
 295 {
 296   /* The first entry in a lazy procedure linkage table looks like this.  */
 297   const bfd_byte *plt0_entry;
 298   unsigned int plt0_entry_size;          /* Size of PLT0 entry.  */
 299
 300   /* Later entries in a lazy procedure linkage table look like this.  */
 301   const bfd_byte *plt_entry;
 302   unsigned int plt_entry_size;          /* Size of each PLT entry.  */
 303
 304   /* The TLSDESC entry in a lazy procedure linkage table looks like
 305      this.  This is for x86-64 only.  */
 306   const bfd_byte *plt_tlsdesc_entry;
 307   unsigned int plt_tlsdesc_entry_size;   /* Size of TLSDESC entry.  */
 308
 309   /* Offsets into the TLSDESC entry that are to be replaced with
 310      GOT+8 and GOT+TDG.  These are for x86-64 only.  */
 311   unsigned int plt_tlsdesc_got1_offset;
 312   unsigned int plt_tlsdesc_got2_offset;
 313
 314   /* Offset of the end of the PC-relative instructions containing
 315      plt_tlsdesc_got1_offset and plt_tlsdesc_got2_offset.  These
 316      are for x86-64 only.  */
 317   unsigned int plt_tlsdesc_got1_insn_end;
 318   unsigned int plt_tlsdesc_got2_insn_end;
 319
 320   /* Offsets into plt0_entry that are to be replaced with GOT[1] and
 321      GOT[2].  */
 322   unsigned int plt0_got1_offset;
 323   unsigned int plt0_got2_offset;
 324
 325   /* Offset of the end of the PC-relative instruction containing
 326      plt0_got2_offset.  This is for x86-64 only.  */
 327   unsigned int plt0_got2_insn_end;
 328
 329   /* Offsets into plt_entry that are to be replaced with...  */
 330   unsigned int plt_got_offset;    /* ... address of this symbol in .got. */
 331   unsigned int plt_reloc_offset;  /* ... offset into relocation table. */
 332   unsigned int plt_plt_offset;    /* ... offset to start of .plt. */
 333
 334   /* Length of the PC-relative instruction containing plt_got_offset.
 335      This is used for x86-64 only.  */
 336   unsigned int plt_got_insn_size;
 337
 338   /* Offset of the end of the PC-relative jump to plt0_entry.  This is
 339      used for x86-64 only.  */
 340   unsigned int plt_plt_insn_end;
 341
 342   /* Offset into plt_entry where the initial value of the GOT entry
 343      points.  */
 344   unsigned int plt_lazy_offset;
 345
 346   /* The first entry in a PIC lazy procedure linkage table looks like
 347      this.  */
 348   const bfd_byte *pic_plt0_entry;
 349
 350   /* Subsequent entries in a PIC lazy procedure linkage table look
 351      like this.  */
 352   const bfd_byte *pic_plt_entry;
 353
 354   /* .eh_frame covering the lazy .plt section.  */
 355   const bfd_byte *eh_frame_plt;
 356   unsigned int eh_frame_plt_size;
 357 };
 358
 359 struct elf_x86_non_lazy_plt_layout
 360 {
 361   /* Entries in a non-lazy procedure linkage table look like this.  */
 362   const bfd_byte *plt_entry;
 363   /* Entries in a PIC non-lazy procedure linkage table look like this.
 364      This is only used for i386 where absolute PLT and PIC PLT are
 365      different.  */
 366   const bfd_byte *pic_plt_entry;
 367
 368   unsigned int plt_entry_size;          /* Size of each PLT entry.  */
 369
 370   /* Offsets into plt_entry that are to be replaced with...  */
 371   unsigned int plt_got_offset;    /* ... address of this symbol in .got. */
 372
 373   /* Length of the PC-relative instruction containing plt_got_offset.
 374      This is used for x86-64 only.  */
 375   unsigned int plt_got_insn_size;
 376
 377   /* .eh_frame covering the non-lazy .plt section.  */
 378   const bfd_byte *eh_frame_plt;
 379   unsigned int eh_frame_plt_size;
 380 };
 381
 382 struct elf_x86_plt_layout
 383 {
 384   /* The first entry in a lazy procedure linkage table looks like this.  */
 385   const bfd_byte *plt0_entry;
 386   /* Entries in a procedure linkage table look like this.  */
 387   const bfd_byte *plt_entry;
 388   unsigned int plt_entry_size;          /* Size of each PLT entry.  */
 389
 390   /* 1 has PLT0.  */
 391   unsigned int has_plt0;
 392
 393   /* Offsets into plt_entry that are to be replaced with...  */
 394   unsigned int plt_got_offset;    /* ... address of this symbol in .got. */
 395
 396   /* Length of the PC-relative instruction containing plt_got_offset.
 397      This is only used for x86-64.  */
 398   unsigned int plt_got_insn_size;
 399
 400   /* Alignment of the .iplt section.  */
 401   unsigned int iplt_alignment;
 402
 403   /* .eh_frame covering the .plt section.  */
 404   const bfd_byte *eh_frame_plt;
 405   unsigned int eh_frame_plt_size;
 406 };
 407
 408 /* Values in tls_type of x86 ELF linker hash entry.  */
 409 #define GOT_UNKNOWN     0
 410 #define GOT_NORMAL      1
 411 #define GOT_TLS_GD      2
 412 #define GOT_TLS_IE      4
 413 #define GOT_TLS_IE_POS  5
 414 #define GOT_TLS_IE_NEG  6
 415 #define GOT_TLS_IE_BOTH 7
 416 #define GOT_TLS_GDESC   8
 417 #define GOT_TLS_GD_BOTH_P(type) \
 418   ((type) == (GOT_TLS_GD | GOT_TLS_GDESC))
 419 #define GOT_TLS_GD_P(type) \
 420   ((type) == GOT_TLS_GD || GOT_TLS_GD_BOTH_P (type))
 421 #define GOT_TLS_GDESC_P(type) \
 422   ((type) == GOT_TLS_GDESC || GOT_TLS_GD_BOTH_P (type))
 423 #define GOT_TLS_GD_ANY_P(type) \
 424   (GOT_TLS_GD_P (type) || GOT_TLS_GDESC_P (type))
 425
 426 #define elf_x86_hash_entry(ent) \
 427   ((struct elf_x86_link_hash_entry *)(ent))
 428
 429 enum elf_x86_target_os
 430 {
 431   is_normal,
 432   is_solaris,
 433   is_vxworks,
 434   is_nacl
 435 };
 436
 437 /* x86 ELF linker hash table.  */
 438
 439 struct elf_x86_link_hash_table
 440 {
 441   struct elf_link_hash_table elf;
 442
 443   /* Short-cuts to get to dynamic linker sections.  */
 444   asection *interp;
 445   asection *plt_eh_frame;
 446   asection *plt_second;
 447   asection *plt_second_eh_frame;
 448   asection *plt_got;
 449   asection *plt_got_eh_frame;
 450
 451   /* Parameters describing PLT generation, lazy or non-lazy.  */
 452   struct elf_x86_plt_layout plt;
 453
 454   /* Parameters describing lazy PLT generation.  */
 455   const struct elf_x86_lazy_plt_layout *lazy_plt;
 456
 457   /* Parameters describing non-lazy PLT generation.  */
 458   const struct elf_x86_non_lazy_plt_layout *non_lazy_plt;
 459
 460   union
 461   {
 462     bfd_signed_vma refcount;
 463     bfd_vma offset;
 464   } tls_ld_or_ldm_got;
 465
 466   /* The amount of space used by the jump slots in the GOT.  */
 467   bfd_vma sgotplt_jump_table_size;
 468
 469   /* Small local sym cache.  */
 470   struct sym_cache sym_cache;
 471
 472   /* _TLS_MODULE_BASE_ symbol.  */
 473   struct bfd_link_hash_entry *tls_module_base;
 474
 475   /* Used by local STT_GNU_IFUNC symbols.  */
 476   htab_t loc_hash_table;
 477   void * loc_hash_memory;
 478
 479   /* The offset into sgot of the GOT entry used by the PLT entry
 480      above.  */
 481   bfd_vma tlsdesc_got;
 482
 483   /* The index of the next R_X86_64_JUMP_SLOT entry in .rela.plt.  */
 484   bfd_vma next_jump_slot_index;
 485   /* The index of the next R_X86_64_IRELATIVE entry in .rela.plt.  */
 486   bfd_vma next_irelative_index;
 487
 488   /* TRUE if there are dynamic relocs against IFUNC symbols that apply
 489      to read-only sections.  */
 490   bfd_boolean readonly_dynrelocs_against_ifunc;
 491
 492   /* The (unloaded but important) .rel.plt.unloaded section on VxWorks.
 493      This is used for i386 only.  */
 494   asection *srelplt2;
 495
 496   /* The index of the next unused R_386_TLS_DESC slot in .rel.plt.  This
 497      is only used for i386.  */
 498   bfd_vma next_tls_desc_index;
 499
 500   /* The offset into splt of the PLT entry for the TLS descriptor
 501      resolver.  Special values are 0, if not necessary (or not found
 502      to be necessary yet), and -1 if needed but not determined
 503      yet.  This is only used for x86-64.  */
 504   bfd_vma tlsdesc_plt;
 505
 506    /* Value used to fill the unused bytes of the first PLT entry.  This
 507       is only used for i386.  */
 508   bfd_byte plt0_pad_byte;
 509
 510   /* TRUE if GOT is referenced.  */
 511   unsigned int got_referenced : 1;
 512
 513   /* TRUE if PLT is PC-relative.  PLT in PDE and PC-relative PLT in PIE
 514      can be used as function address.
 515
 516      NB: i386 has non-PIC PLT and PIC PLT.  Only non-PIC PLT in PDE can
 517      be used as function address.  PIC PLT in PIE can't be used as
 518      function address.  */
 519   unsigned int pcrel_plt : 1;
 520
 521   bfd_vma (*r_info) (bfd_vma, bfd_vma);
 522   bfd_vma (*r_sym) (bfd_vma);
 523   bfd_boolean (*is_reloc_section) (const char *);
 524   enum elf_target_id target_id;
 525   enum elf_x86_target_os target_os;
 526   unsigned int sizeof_reloc;
 527   unsigned int dt_reloc;
 528   unsigned int dt_reloc_sz;
 529   unsigned int dt_reloc_ent;
 530   unsigned int got_entry_size;
 531   unsigned int pointer_r_type;
 532   int dynamic_interpreter_size;
 533   const char *dynamic_interpreter;
 534   const char *tls_get_addr;
 535
 536   /* Options passed from the linker.  */
 537   struct elf_linker_x86_params *params;
 538 };
 539
 540 /* Architecture-specific backend data for x86.  */
 541
 542 struct elf_x86_backend_data
 543 {
 544   /* Target system.  */
 545   enum elf_x86_target_os target_os;
 546 };
 547
 548 #define get_elf_x86_backend_data(abfd) \
 549   ((const struct elf_x86_backend_data *) \
 550    get_elf_backend_data (abfd)->arch_data)
 551
 552 struct elf_x86_init_table
 553 {
 554   /* The lazy PLT layout.  */
 555   const struct elf_x86_lazy_plt_layout *lazy_plt;
 556
 557   /* The non-lazy PLT layout.  */
 558   const struct elf_x86_non_lazy_plt_layout *non_lazy_plt;
 559
 560   /* The lazy PLT layout for IBT.  */
 561   const struct elf_x86_lazy_plt_layout *lazy_ibt_plt;
 562
 563   /* The non-lazy PLT layout for IBT.  */
 564   const struct elf_x86_non_lazy_plt_layout *non_lazy_ibt_plt;
 565
 566   bfd_byte plt0_pad_byte;
 567
 568   bfd_vma (*r_info) (bfd_vma, bfd_vma);
 569   bfd_vma (*r_sym) (bfd_vma);
 570 };
 571
 572 struct elf_x86_obj_tdata
 573 {
 574   struct elf_obj_tdata root;
 575
 576   /* tls_type for each local got entry.  */
 577   char *local_got_tls_type;
 578
 579   /* GOTPLT entries for TLS descriptors.  */
 580   bfd_vma *local_tlsdesc_gotent;
 581 };
 582
 583 enum elf_x86_plt_type
 584 {
 585   plt_non_lazy = 0,
 586   plt_lazy = 1 << 0,
 587   plt_pic = 1 << 1,
 588   plt_second = 1 << 2,
 589   plt_unknown = -1
 590 };
 591
 592 struct elf_x86_plt
 593 {
 594   const char *name;
 595   asection *sec;
 596   bfd_byte *contents;
 597   enum elf_x86_plt_type type;
 598   unsigned int plt_got_offset;
 599   unsigned int plt_entry_size;
 600   unsigned int plt_got_insn_size;       /* Only used for x86-64.  */
 601   long count;
 602 };
 603
 604 #define elf_x86_tdata(abfd) \
 605   ((struct elf_x86_obj_tdata *) (abfd)->tdata.any)
 606
 607 #define elf_x86_local_got_tls_type(abfd) \
 608   (elf_x86_tdata (abfd)->local_got_tls_type)
 609
 610 #define elf_x86_local_tlsdesc_gotent(abfd) \
 611   (elf_x86_tdata (abfd)->local_tlsdesc_gotent)
 612
 613 #define elf_x86_compute_jump_table_size(htab) \
 614   ((htab)->elf.srelplt->reloc_count * (htab)->got_entry_size)
 615
 616 #define is_x86_elf(bfd, htab)                           \
 617   (bfd_get_flavour (bfd) == bfd_target_elf_flavour      \
 618    && elf_tdata (bfd) != NULL                           \
 619    && elf_object_id (bfd) == (htab)->target_id)
 620
 621 extern bfd_boolean _bfd_x86_elf_mkobject
 622   (bfd *);
 623
 624 extern void _bfd_x86_elf_set_tls_module_base
 625   (struct bfd_link_info *);
 626
 627 extern bfd_vma _bfd_x86_elf_dtpoff_base
 628   (struct bfd_link_info *);
 629
 630 extern bfd_boolean _bfd_x86_elf_readonly_dynrelocs
 631   (struct elf_link_hash_entry *, void *);
 632
 633 extern struct elf_link_hash_entry * _bfd_elf_x86_get_local_sym_hash
 634   (struct elf_x86_link_hash_table *, bfd *, const Elf_Internal_Rela *,
 635    bfd_boolean);
 636
 637 extern hashval_t _bfd_x86_elf_local_htab_hash
 638   (const void *);
 639
 640 extern int _bfd_x86_elf_local_htab_eq
 641   (const void *, const void *);
 642
 643 extern struct bfd_hash_entry * _bfd_x86_elf_link_hash_newfunc
 644   (struct bfd_hash_entry *, struct bfd_hash_table *, const char *);
 645
 646 extern struct bfd_link_hash_table * _bfd_x86_elf_link_hash_table_create
 647   (bfd *);
 648
 649 extern int _bfd_x86_elf_compare_relocs
 650   (const void *, const void *);
 651
 652 extern bfd_boolean _bfd_x86_elf_link_check_relocs
 653   (bfd *, struct bfd_link_info *);
 654
 655 extern bfd_boolean _bfd_x86_elf_size_dynamic_sections
 656   (bfd *, struct bfd_link_info *);
 657
 658 extern struct elf_x86_link_hash_table *_bfd_x86_elf_finish_dynamic_sections
 659   (bfd *, struct bfd_link_info *);
 660
 661 extern bfd_boolean _bfd_x86_elf_always_size_sections
 662   (bfd *, struct bfd_link_info *);
 663
 664 extern void _bfd_x86_elf_merge_symbol_attribute
 665   (struct elf_link_hash_entry *, const Elf_Internal_Sym *,
 666    bfd_boolean, bfd_boolean);
 667
 668 extern void _bfd_x86_elf_copy_indirect_symbol
 669   (struct bfd_link_info *, struct elf_link_hash_entry *,
 670    struct elf_link_hash_entry *);
 671
 672 extern bfd_boolean _bfd_x86_elf_fixup_symbol
 673   (struct bfd_link_info *, struct elf_link_hash_entry *);
 674
 675 extern bfd_boolean _bfd_x86_elf_hash_symbol
 676   (struct elf_link_hash_entry *);
 677
 678 extern bfd_boolean _bfd_x86_elf_adjust_dynamic_symbol
 679   (struct bfd_link_info *, struct elf_link_hash_entry *);
 680
 681 extern void _bfd_x86_elf_hide_symbol
 682   (struct bfd_link_info *, struct elf_link_hash_entry *, bfd_boolean);
 683
 684 extern bfd_boolean _bfd_x86_elf_link_symbol_references_local
 685   (struct bfd_link_info *, struct elf_link_hash_entry *);
 686
 687 extern asection * _bfd_x86_elf_gc_mark_hook
 688   (asection *, struct bfd_link_info *, Elf_Internal_Rela *,
 689    struct elf_link_hash_entry *, Elf_Internal_Sym *);
 690
 691 extern long _bfd_x86_elf_get_synthetic_symtab
 692   (bfd *, long, long, bfd_vma, struct elf_x86_plt [], asymbol **,
 693    asymbol **);
 694
 695 extern enum elf_property_kind _bfd_x86_elf_parse_gnu_properties
 696   (bfd *, unsigned int, bfd_byte *, unsigned int);
 697
 698 extern bfd_boolean _bfd_x86_elf_merge_gnu_properties
 699   (struct bfd_link_info *, bfd *, bfd *, elf_property *, elf_property *);
 700
 701 extern void _bfd_x86_elf_link_fixup_gnu_properties
 702   (struct bfd_link_info *, elf_property_list **);
 703
 704 extern bfd * _bfd_x86_elf_link_setup_gnu_properties
 705   (struct bfd_link_info *, struct elf_x86_init_table *);
 706
 707 extern void _bfd_x86_elf_link_fixup_ifunc_symbol
 708   (struct bfd_link_info *, struct elf_x86_link_hash_table *,
 709    struct elf_link_hash_entry *, Elf_Internal_Sym *sym);
 710
 711 #define bfd_elf64_mkobject \
 712   _bfd_x86_elf_mkobject
 713 #define bfd_elf32_mkobject \
 714   _bfd_x86_elf_mkobject
 715 #define bfd_elf64_bfd_link_hash_table_create \
 716   _bfd_x86_elf_link_hash_table_create
 717 #define bfd_elf32_bfd_link_hash_table_create \
 718   _bfd_x86_elf_link_hash_table_create
 719 #define bfd_elf64_bfd_link_check_relocs \
 720   _bfd_x86_elf_link_check_relocs
 721 #define bfd_elf32_bfd_link_check_relocs \
 722   _bfd_x86_elf_link_check_relocs
 723
 724 #define elf_backend_size_dynamic_sections \
 725   _bfd_x86_elf_size_dynamic_sections
 726 #define elf_backend_always_size_sections \
 727   _bfd_x86_elf_always_size_sections
 728 #define elf_backend_merge_symbol_attribute \
 729   _bfd_x86_elf_merge_symbol_attribute
 730 #define elf_backend_copy_indirect_symbol \
 731   _bfd_x86_elf_copy_indirect_symbol
 732 #define elf_backend_fixup_symbol \
 733   _bfd_x86_elf_fixup_symbol
 734 #define elf_backend_hash_symbol \
 735   _bfd_x86_elf_hash_symbol
 736 #define elf_backend_adjust_dynamic_symbol \
 737   _bfd_x86_elf_adjust_dynamic_symbol
 738 #define elf_backend_gc_mark_hook \
 739   _bfd_x86_elf_gc_mark_hook
 740 #define elf_backend_omit_section_dynsym \
 741   _bfd_elf_omit_section_dynsym_all
 742 #define elf_backend_parse_gnu_properties \
 743   _bfd_x86_elf_parse_gnu_properties
 744 #define elf_backend_merge_gnu_properties \
 745   _bfd_x86_elf_merge_gnu_properties
 746 #define elf_backend_fixup_gnu_properties \
 747   _bfd_x86_elf_link_fixup_gnu_properties