bfd/elfxx-x86.h

   1 /* x86 specific support for ELF
   2    Copyright (C) 2017-2020 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.  Don't generate dynamic relocations against
 123    non-preemptible absolute symbol.  */
 124 #define GENERATE_DYNAMIC_RELOCATION_P(INFO, EH, R_TYPE, SEC, \
 125                                       NEED_COPY_RELOC_IN_PIE, \
 126                                       RESOLVED_TO_ZERO, PC32_RELOC) \
 127   ((bfd_link_pic (INFO) \
 128     && !(bfd_is_abs_section (SEC) \
 129          && ((EH) == NULL \
 130              || SYMBOL_REFERENCES_LOCAL (INFO, &(EH)->elf))) \
 131     && !(NEED_COPY_RELOC_IN_PIE) \
 132     && ((EH) == NULL \
 133         || ((ELF_ST_VISIBILITY ((EH)->elf.other) == STV_DEFAULT \
 134              && (!(RESOLVED_TO_ZERO) || PC32_RELOC)) \
 135             || (EH)->elf.root.type != bfd_link_hash_undefweak)) \
 136     && ((!X86_PCREL_TYPE_P (R_TYPE) && !X86_SIZE_TYPE_P (R_TYPE)) \
 137         || ! SYMBOL_CALLS_LOCAL ((INFO), \
 138                                  (struct elf_link_hash_entry *) (EH)))) \
 139    || (ELIMINATE_COPY_RELOCS \
 140        && !bfd_link_pic (INFO) \
 141        && (EH) != NULL \
 142        && (EH)->elf.dynindx != -1 \
 143        && (!(EH)->elf.non_got_ref \
 144            || ((EH)->elf.root.type == bfd_link_hash_undefweak \
 145                && !(RESOLVED_TO_ZERO))) \
 146                && (((EH)->elf.def_dynamic && !(EH)->elf.def_regular) \
 147                    || (EH)->elf.root.type == bfd_link_hash_undefined)))
 148
 149 /* TRUE if this input relocation should be copied to output.  H->dynindx
 150    may be -1 if this symbol was marked to become local.  */
 151 #define COPY_INPUT_RELOC_P(INFO, H, R_TYPE) \
 152   ((H) != NULL \
 153    && (H)->dynindx != -1 \
 154    && (X86_PCREL_TYPE_P (R_TYPE) \
 155        || !(bfd_link_executable (INFO) || SYMBOLIC_BIND ((INFO), (H))) \
 156        || !(H)->def_regular))
 157
 158 /* TRUE if this is actually a static link, or it is a -Bsymbolic link
 159    and the symbol is defined locally, or the symbol was forced to be
 160    local because of a version file.  */
 161 #define RESOLVED_LOCALLY_P(INFO, H, HTAB) \
 162   (!WILL_CALL_FINISH_DYNAMIC_SYMBOL ((HTAB)->elf.dynamic_sections_created, \
 163                                      bfd_link_pic (INFO), (H)) \
 164    || (bfd_link_pic (INFO) \
 165        && SYMBOL_REFERENCES_LOCAL_P ((INFO), (H))) \
 166        || (ELF_ST_VISIBILITY ((H)->other) \
 167            && (H)->root.type == bfd_link_hash_undefweak))
 168
 169 /* TRUE if this symbol isn't defined by a shared object.  */
 170 #define SYMBOL_DEFINED_NON_SHARED_P(H) \
 171   ((H)->def_regular \
 172    || (H)->root.linker_def \
 173    || (H)->root.ldscript_def \
 174    || ((struct elf_x86_link_hash_entry *) (H))->linker_def \
 175    || ELF_COMMON_DEF_P (H))
 176
 177 /* Return TRUE if the symbol described by a linker hash entry H is
 178    going to be absolute.  Similar to bfd_is_abs_symbol, but excluding
 179    all linker-script defined symbols.  */
 180 #define ABS_SYMBOL_P(H) \
 181   (bfd_is_abs_symbol (&(H)->root) && !(H)->root.ldscript_def)
 182
 183 /* TRUE if relative relocation should be generated.  GOT reference to
 184    global symbol in PIC will lead to dynamic symbol.  It becomes a
 185    problem when "time" or "times" is defined as a variable in an
 186    executable, clashing with functions of the same name in libc.  If a
 187    symbol isn't undefined weak symbol, don't make it dynamic in PIC and
 188    generate relative relocation.   Don't generate relative relocation
 189    against non-preemptible absolute symbol.  */
 190 #define GENERATE_RELATIVE_RELOC_P(INFO, H) \
 191   ((H)->dynindx == -1 \
 192    && !(H)->forced_local \
 193    && (H)->root.type != bfd_link_hash_undefweak \
 194    && bfd_link_pic (INFO) \
 195    && !ABS_SYMBOL_P (H))
 196
 197 /* TRUE if this is a pointer reference to a local IFUNC.  */
 198 #define POINTER_LOCAL_IFUNC_P(INFO, H) \
 199   ((H)->dynindx == -1 \
 200    || (H)->forced_local \
 201    || bfd_link_executable (INFO))
 202
 203 /* TRUE if this is a PLT reference to a local IFUNC.  */
 204 #define PLT_LOCAL_IFUNC_P(INFO, H) \
 205   ((H)->dynindx == -1 \
 206    || ((bfd_link_executable (INFO) \
 207         || ELF_ST_VISIBILITY ((H)->other) != STV_DEFAULT) \
 208         && (H)->def_regular \
 209         && (H)->type == STT_GNU_IFUNC))
 210
 211 /* TRUE if TLS IE->LE transition is OK.  */
 212 #define TLS_TRANSITION_IE_TO_LE_P(INFO, H, TLS_TYPE) \
 213   (bfd_link_executable (INFO) \
 214    && (H) != NULL \
 215    && (H)->dynindx == -1 \
 216    && (TLS_TYPE & GOT_TLS_IE))
 217
 218 /* Verify that the symbol has an entry in the procedure linkage table.  */
 219 #define VERIFY_PLT_ENTRY(INFO, H, PLT, GOTPLT, RELPLT, LOCAL_UNDEFWEAK) \
 220   do \
 221     { \
 222       if (((H)->dynindx == -1 \
 223            && !LOCAL_UNDEFWEAK \
 224            && !(((H)->forced_local || bfd_link_executable (INFO)) \
 225                 && (H)->def_regular \
 226                 && (H)->type == STT_GNU_IFUNC)) \
 227           || (PLT) == NULL \
 228           || (GOTPLT) == NULL \
 229           || (RELPLT) == NULL) \
 230         abort (); \
 231     } \
 232   while (0);
 233
 234 /* Verify that the symbol supports copy relocation.  */
 235 #define VERIFY_COPY_RELOC(H, HTAB) \
 236   do \
 237     { \
 238       if ((H)->dynindx == -1 \
 239           || ((H)->root.type != bfd_link_hash_defined \
 240               && (H)->root.type != bfd_link_hash_defweak) \
 241           || (HTAB)->elf.srelbss == NULL \
 242           || (HTAB)->elf.sreldynrelro == NULL) \
 243         abort (); \
 244     } \
 245   while (0);
 246
 247 /* x86 ELF linker hash entry.  */
 248
 249 struct elf_x86_link_hash_entry
 250 {
 251   struct elf_link_hash_entry elf;
 252
 253   unsigned char tls_type;
 254
 255   /* Bit 0: Symbol has no GOT nor PLT relocations.
 256      Bit 1: Symbol has non-GOT/non-PLT relocations in text sections.
 257      zero_undefweak is initialized to 1 and undefined weak symbol
 258      should be resolved to 0 if zero_undefweak > 0.  */
 259   unsigned int zero_undefweak : 2;
 260
 261   /* Don't call finish_dynamic_symbol on this symbol.  */
 262   unsigned int no_finish_dynamic_symbol : 1;
 263
 264   /* TRUE if symbol is __tls_get_addr.  */
 265   unsigned int tls_get_addr : 1;
 266
 267   /* TRUE if symbol is defined as a protected symbol.  */
 268   unsigned int def_protected : 1;
 269
 270   /* 0: Symbol references are unknown.
 271      1: Symbol references aren't local.
 272      2: Symbol references are local.
 273    */
 274   unsigned int local_ref : 2;
 275
 276   /* TRUE if symbol is defined by linker.  */
 277   unsigned int linker_def : 1;
 278
 279   /* TRUE if symbol is referenced by R_386_GOTOFF relocation.  This is
 280      only used by i386.  */
 281   unsigned int gotoff_ref : 1;
 282
 283   /* TRUE if a weak symbol with a real definition needs a copy reloc.
 284      When there is a weak symbol with a real definition, the processor
 285      independent code will have arranged for us to see the real
 286      definition first.  We need to copy the needs_copy bit from the
 287      real definition and check it when allowing copy reloc in PIE.  This
 288      is only used by x86-64.  */
 289   unsigned int needs_copy : 1;
 290
 291   /* Information about the GOT PLT entry. Filled when there are both
 292      GOT and PLT relocations against the same function.  */
 293   union gotplt_union plt_got;
 294
 295   /* Information about the second PLT entry.   */
 296   union gotplt_union plt_second;
 297
 298   /* Offset of the GOTPLT entry reserved for the TLS descriptor,
 299      starting at the end of the jump table.  */
 300   bfd_vma tlsdesc_got;
 301 };
 302
 303 struct elf_x86_lazy_plt_layout
 304 {
 305   /* The first entry in a lazy procedure linkage table looks like this.  */
 306   const bfd_byte *plt0_entry;
 307   unsigned int plt0_entry_size;          /* Size of PLT0 entry.  */
 308
 309   /* Later entries in a lazy procedure linkage table look like this.  */
 310   const bfd_byte *plt_entry;
 311   unsigned int plt_entry_size;          /* Size of each PLT entry.  */
 312
 313   /* The TLSDESC entry in a lazy procedure linkage table looks like
 314      this.  This is for x86-64 only.  */
 315   const bfd_byte *plt_tlsdesc_entry;
 316   unsigned int plt_tlsdesc_entry_size;   /* Size of TLSDESC entry.  */
 317
 318   /* Offsets into the TLSDESC entry that are to be replaced with
 319      GOT+8 and GOT+TDG.  These are for x86-64 only.  */
 320   unsigned int plt_tlsdesc_got1_offset;
 321   unsigned int plt_tlsdesc_got2_offset;
 322
 323   /* Offset of the end of the PC-relative instructions containing
 324      plt_tlsdesc_got1_offset and plt_tlsdesc_got2_offset.  These
 325      are for x86-64 only.  */
 326   unsigned int plt_tlsdesc_got1_insn_end;
 327   unsigned int plt_tlsdesc_got2_insn_end;
 328
 329   /* Offsets into plt0_entry that are to be replaced with GOT[1] and
 330      GOT[2].  */
 331   unsigned int plt0_got1_offset;
 332   unsigned int plt0_got2_offset;
 333
 334   /* Offset of the end of the PC-relative instruction containing
 335      plt0_got2_offset.  This is for x86-64 only.  */
 336   unsigned int plt0_got2_insn_end;
 337
 338   /* Offsets into plt_entry that are to be replaced with...  */
 339   unsigned int plt_got_offset;    /* ... address of this symbol in .got. */
 340   unsigned int plt_reloc_offset;  /* ... offset into relocation table. */
 341   unsigned int plt_plt_offset;    /* ... offset to start of .plt. */
 342
 343   /* Length of the PC-relative instruction containing plt_got_offset.
 344      This is used for x86-64 only.  */
 345   unsigned int plt_got_insn_size;
 346
 347   /* Offset of the end of the PC-relative jump to plt0_entry.  This is
 348      used for x86-64 only.  */
 349   unsigned int plt_plt_insn_end;
 350
 351   /* Offset into plt_entry where the initial value of the GOT entry
 352      points.  */
 353   unsigned int plt_lazy_offset;
 354
 355   /* The first entry in a PIC lazy procedure linkage table looks like
 356      this.  */
 357   const bfd_byte *pic_plt0_entry;
 358
 359   /* Subsequent entries in a PIC lazy procedure linkage table look
 360      like this.  */
 361   const bfd_byte *pic_plt_entry;
 362
 363   /* .eh_frame covering the lazy .plt section.  */
 364   const bfd_byte *eh_frame_plt;
 365   unsigned int eh_frame_plt_size;
 366 };
 367
 368 struct elf_x86_non_lazy_plt_layout
 369 {
 370   /* Entries in a non-lazy procedure linkage table look like this.  */
 371   const bfd_byte *plt_entry;
 372   /* Entries in a PIC non-lazy procedure linkage table look like this.
 373      This is only used for i386 where absolute PLT and PIC PLT are
 374      different.  */
 375   const bfd_byte *pic_plt_entry;
 376
 377   unsigned int plt_entry_size;          /* Size of each PLT entry.  */
 378
 379   /* Offsets into plt_entry that are to be replaced with...  */
 380   unsigned int plt_got_offset;    /* ... address of this symbol in .got. */
 381
 382   /* Length of the PC-relative instruction containing plt_got_offset.
 383      This is used for x86-64 only.  */
 384   unsigned int plt_got_insn_size;
 385
 386   /* .eh_frame covering the non-lazy .plt section.  */
 387   const bfd_byte *eh_frame_plt;
 388   unsigned int eh_frame_plt_size;
 389 };
 390
 391 struct elf_x86_plt_layout
 392 {
 393   /* The first entry in a lazy procedure linkage table looks like this.  */
 394   const bfd_byte *plt0_entry;
 395   /* Entries in a procedure linkage table look like this.  */
 396   const bfd_byte *plt_entry;
 397   unsigned int plt_entry_size;          /* Size of each PLT entry.  */
 398
 399   /* 1 has PLT0.  */
 400   unsigned int has_plt0;
 401
 402   /* Offsets into plt_entry that are to be replaced with...  */
 403   unsigned int plt_got_offset;    /* ... address of this symbol in .got. */
 404
 405   /* Length of the PC-relative instruction containing plt_got_offset.
 406      This is only used for x86-64.  */
 407   unsigned int plt_got_insn_size;
 408
 409   /* Alignment of the .iplt section.  */
 410   unsigned int iplt_alignment;
 411
 412   /* .eh_frame covering the .plt section.  */
 413   const bfd_byte *eh_frame_plt;
 414   unsigned int eh_frame_plt_size;
 415 };
 416
 417 /* Values in tls_type of x86 ELF linker hash entry.  */
 418 #define GOT_UNKNOWN     0
 419 #define GOT_NORMAL      1
 420 #define GOT_TLS_GD      2
 421 #define GOT_TLS_IE      4
 422 #define GOT_TLS_IE_POS  5
 423 #define GOT_TLS_IE_NEG  6
 424 #define GOT_TLS_IE_BOTH 7
 425 #define GOT_TLS_GDESC   8
 426 #define GOT_ABS         9
 427 #define GOT_TLS_GD_BOTH_P(type) \
 428   ((type) == (GOT_TLS_GD | GOT_TLS_GDESC))
 429 #define GOT_TLS_GD_P(type) \
 430   ((type) == GOT_TLS_GD || GOT_TLS_GD_BOTH_P (type))
 431 #define GOT_TLS_GDESC_P(type) \
 432   ((type) == GOT_TLS_GDESC || GOT_TLS_GD_BOTH_P (type))
 433 #define GOT_TLS_GD_ANY_P(type) \
 434   (GOT_TLS_GD_P (type) || GOT_TLS_GDESC_P (type))
 435
 436 #define elf_x86_hash_entry(ent) \
 437   ((struct elf_x86_link_hash_entry *)(ent))
 438
 439 enum elf_x86_target_os
 440 {
 441   is_normal,
 442   is_solaris,
 443   is_vxworks,
 444   is_nacl
 445 };
 446
 447 /* x86 ELF linker hash table.  */
 448
 449 struct elf_x86_link_hash_table
 450 {
 451   struct elf_link_hash_table elf;
 452
 453   /* Short-cuts to get to dynamic linker sections.  */
 454   asection *interp;
 455   asection *plt_eh_frame;
 456   asection *plt_second;
 457   asection *plt_second_eh_frame;
 458   asection *plt_got;
 459   asection *plt_got_eh_frame;
 460
 461   /* Parameters describing PLT generation, lazy or non-lazy.  */
 462   struct elf_x86_plt_layout plt;
 463
 464   /* Parameters describing lazy PLT generation.  */
 465   const struct elf_x86_lazy_plt_layout *lazy_plt;
 466
 467   /* Parameters describing non-lazy PLT generation.  */
 468   const struct elf_x86_non_lazy_plt_layout *non_lazy_plt;
 469
 470   union
 471   {
 472     bfd_signed_vma refcount;
 473     bfd_vma offset;
 474   } tls_ld_or_ldm_got;
 475
 476   /* The amount of space used by the jump slots in the GOT.  */
 477   bfd_vma sgotplt_jump_table_size;
 478
 479   /* Small local sym cache.  */
 480   struct sym_cache sym_cache;
 481
 482   /* _TLS_MODULE_BASE_ symbol.  */
 483   struct bfd_link_hash_entry *tls_module_base;
 484
 485   /* Used by local STT_GNU_IFUNC symbols.  */
 486   htab_t loc_hash_table;
 487   void * loc_hash_memory;
 488
 489   /* The offset into sgot of the GOT entry used by the PLT entry
 490      above.  */
 491   bfd_vma tlsdesc_got;
 492
 493   /* The index of the next R_X86_64_JUMP_SLOT entry in .rela.plt.  */
 494   bfd_vma next_jump_slot_index;
 495   /* The index of the next R_X86_64_IRELATIVE entry in .rela.plt.  */
 496   bfd_vma next_irelative_index;
 497
 498   /* TRUE if there are dynamic relocs against IFUNC symbols that apply
 499      to read-only sections.  */
 500   bfd_boolean readonly_dynrelocs_against_ifunc;
 501
 502   /* The (unloaded but important) .rel.plt.unloaded section on VxWorks.
 503      This is used for i386 only.  */
 504   asection *srelplt2;
 505
 506   /* The index of the next unused R_386_TLS_DESC slot in .rel.plt.  This
 507      is only used for i386.  */
 508   bfd_vma next_tls_desc_index;
 509
 510   /* The offset into splt of the PLT entry for the TLS descriptor
 511      resolver.  Special values are 0, if not necessary (or not found
 512      to be necessary yet), and -1 if needed but not determined
 513      yet.  This is only used for x86-64.  */
 514   bfd_vma tlsdesc_plt;
 515
 516    /* Value used to fill the unused bytes of the first PLT entry.  This
 517       is only used for i386.  */
 518   bfd_byte plt0_pad_byte;
 519
 520   /* TRUE if GOT is referenced.  */
 521   unsigned int got_referenced : 1;
 522
 523   /* TRUE if PLT is PC-relative.  PLT in PDE and PC-relative PLT in PIE
 524      can be used as function address.
 525
 526      NB: i386 has non-PIC PLT and PIC PLT.  Only non-PIC PLT in PDE can
 527      be used as function address.  PIC PLT in PIE can't be used as
 528      function address.  */
 529   unsigned int pcrel_plt : 1;
 530
 531   bfd_vma (*r_info) (bfd_vma, bfd_vma);
 532   bfd_vma (*r_sym) (bfd_vma);
 533   bfd_boolean (*is_reloc_section) (const char *);
 534   enum elf_x86_target_os target_os;
 535   unsigned int sizeof_reloc;
 536   unsigned int dt_reloc;
 537   unsigned int dt_reloc_sz;
 538   unsigned int dt_reloc_ent;
 539   unsigned int got_entry_size;
 540   unsigned int pointer_r_type;
 541   int dynamic_interpreter_size;
 542   const char *dynamic_interpreter;
 543   const char *tls_get_addr;
 544
 545   /* Options passed from the linker.  */
 546   struct elf_linker_x86_params *params;
 547 };
 548
 549 /* Architecture-specific backend data for x86.  */
 550
 551 struct elf_x86_backend_data
 552 {
 553   /* Target system.  */
 554   enum elf_x86_target_os target_os;
 555 };
 556
 557 #define get_elf_x86_backend_data(abfd) \
 558   ((const struct elf_x86_backend_data *) \
 559    get_elf_backend_data (abfd)->arch_data)
 560
 561 struct elf_x86_init_table
 562 {
 563   /* The lazy PLT layout.  */
 564   const struct elf_x86_lazy_plt_layout *lazy_plt;
 565
 566   /* The non-lazy PLT layout.  */
 567   const struct elf_x86_non_lazy_plt_layout *non_lazy_plt;
 568
 569   /* The lazy PLT layout for IBT.  */
 570   const struct elf_x86_lazy_plt_layout *lazy_ibt_plt;
 571
 572   /* The non-lazy PLT layout for IBT.  */
 573   const struct elf_x86_non_lazy_plt_layout *non_lazy_ibt_plt;
 574
 575   bfd_byte plt0_pad_byte;
 576
 577   bfd_vma (*r_info) (bfd_vma, bfd_vma);
 578   bfd_vma (*r_sym) (bfd_vma);
 579 };
 580
 581 struct elf_x86_obj_tdata
 582 {
 583   struct elf_obj_tdata root;
 584
 585   /* tls_type for each local got entry.  */
 586   char *local_got_tls_type;
 587
 588   /* GOTPLT entries for TLS descriptors.  */
 589   bfd_vma *local_tlsdesc_gotent;
 590 };
 591
 592 enum elf_x86_plt_type
 593 {
 594   plt_non_lazy = 0,
 595   plt_lazy = 1 << 0,
 596   plt_pic = 1 << 1,
 597   plt_second = 1 << 2,
 598   plt_unknown = -1
 599 };
 600
 601 struct elf_x86_plt
 602 {
 603   const char *name;
 604   asection *sec;
 605   bfd_byte *contents;
 606   enum elf_x86_plt_type type;
 607   unsigned int plt_got_offset;
 608   unsigned int plt_entry_size;
 609   unsigned int plt_got_insn_size;       /* Only used for x86-64.  */
 610   long count;
 611 };
 612
 613 /* Set if a relocation is converted from a GOTPCREL relocation.  */
 614 #define R_X86_64_converted_reloc_bit (1 << 7)
 615
 616 #define elf_x86_tdata(abfd) \
 617   ((struct elf_x86_obj_tdata *) (abfd)->tdata.any)
 618
 619 #define elf_x86_local_got_tls_type(abfd) \
 620   (elf_x86_tdata (abfd)->local_got_tls_type)
 621
 622 #define elf_x86_local_tlsdesc_gotent(abfd) \
 623   (elf_x86_tdata (abfd)->local_tlsdesc_gotent)
 624
 625 #define elf_x86_compute_jump_table_size(htab) \
 626   ((htab)->elf.srelplt->reloc_count * (htab)->got_entry_size)
 627
 628 #define is_x86_elf(bfd, htab)                           \
 629   (bfd_get_flavour (bfd) == bfd_target_elf_flavour      \
 630    && elf_tdata (bfd) != NULL                           \
 631    && elf_object_id (bfd) == (htab)->elf.hash_table_id)
 632
 633 extern bfd_boolean _bfd_x86_elf_mkobject
 634   (bfd *);
 635
 636 extern void _bfd_x86_elf_set_tls_module_base
 637   (struct bfd_link_info *);
 638
 639 extern bfd_vma _bfd_x86_elf_dtpoff_base
 640   (struct bfd_link_info *);
 641
 642 extern bfd_boolean _bfd_x86_elf_readonly_dynrelocs
 643   (struct elf_link_hash_entry *, void *);
 644
 645 extern struct elf_link_hash_entry * _bfd_elf_x86_get_local_sym_hash
 646   (struct elf_x86_link_hash_table *, bfd *, const Elf_Internal_Rela *,
 647    bfd_boolean);
 648
 649 extern hashval_t _bfd_x86_elf_local_htab_hash
 650   (const void *);
 651
 652 extern int _bfd_x86_elf_local_htab_eq
 653   (const void *, const void *);
 654
 655 extern struct bfd_hash_entry * _bfd_x86_elf_link_hash_newfunc
 656   (struct bfd_hash_entry *, struct bfd_hash_table *, const char *);
 657
 658 extern struct bfd_link_hash_table * _bfd_x86_elf_link_hash_table_create
 659   (bfd *);
 660
 661 extern int _bfd_x86_elf_compare_relocs
 662   (const void *, const void *);
 663
 664 extern bfd_boolean _bfd_x86_elf_link_check_relocs
 665   (bfd *, struct bfd_link_info *);
 666
 667 extern bfd_boolean _bfd_elf_x86_valid_reloc_p
 668   (asection *, struct bfd_link_info *, struct elf_x86_link_hash_table *,
 669    const Elf_Internal_Rela *, struct elf_link_hash_entry *,
 670    Elf_Internal_Sym *, Elf_Internal_Shdr *, bfd_boolean *);
 671
 672 extern bfd_boolean _bfd_x86_elf_size_dynamic_sections
 673   (bfd *, struct bfd_link_info *);
 674
 675 extern struct elf_x86_link_hash_table *_bfd_x86_elf_finish_dynamic_sections
 676   (bfd *, struct bfd_link_info *);
 677
 678 extern bfd_boolean _bfd_x86_elf_always_size_sections
 679   (bfd *, struct bfd_link_info *);
 680
 681 extern void _bfd_x86_elf_merge_symbol_attribute
 682   (struct elf_link_hash_entry *, const Elf_Internal_Sym *,
 683    bfd_boolean, bfd_boolean);
 684
 685 extern void _bfd_x86_elf_copy_indirect_symbol
 686   (struct bfd_link_info *, struct elf_link_hash_entry *,
 687    struct elf_link_hash_entry *);
 688
 689 extern bfd_boolean _bfd_x86_elf_fixup_symbol
 690   (struct bfd_link_info *, struct elf_link_hash_entry *);
 691
 692 extern bfd_boolean _bfd_x86_elf_hash_symbol
 693   (struct elf_link_hash_entry *);
 694
 695 extern bfd_boolean _bfd_x86_elf_adjust_dynamic_symbol
 696   (struct bfd_link_info *, struct elf_link_hash_entry *);
 697
 698 extern void _bfd_x86_elf_hide_symbol
 699   (struct bfd_link_info *, struct elf_link_hash_entry *, bfd_boolean);
 700
 701 extern bfd_boolean _bfd_x86_elf_link_symbol_references_local
 702   (struct bfd_link_info *, struct elf_link_hash_entry *);
 703
 704 extern asection * _bfd_x86_elf_gc_mark_hook
 705   (asection *, struct bfd_link_info *, Elf_Internal_Rela *,
 706    struct elf_link_hash_entry *, Elf_Internal_Sym *);
 707
 708 extern long _bfd_x86_elf_get_synthetic_symtab
 709   (bfd *, long, long, bfd_vma, struct elf_x86_plt [], asymbol **,
 710    asymbol **);
 711
 712 extern enum elf_property_kind _bfd_x86_elf_parse_gnu_properties
 713   (bfd *, unsigned int, bfd_byte *, unsigned int);
 714
 715 extern bfd_boolean _bfd_x86_elf_merge_gnu_properties
 716   (struct bfd_link_info *, bfd *, bfd *, elf_property *, elf_property *);
 717
 718 extern void _bfd_x86_elf_link_fixup_gnu_properties
 719   (struct bfd_link_info *, elf_property_list **);
 720
 721 extern bfd * _bfd_x86_elf_link_setup_gnu_properties
 722   (struct bfd_link_info *, struct elf_x86_init_table *);
 723
 724 extern void _bfd_x86_elf_link_fixup_ifunc_symbol
 725   (struct bfd_link_info *, struct elf_x86_link_hash_table *,
 726    struct elf_link_hash_entry *, Elf_Internal_Sym *sym);
 727
 728 #define bfd_elf64_mkobject \
 729   _bfd_x86_elf_mkobject
 730 #define bfd_elf32_mkobject \
 731   _bfd_x86_elf_mkobject
 732 #define bfd_elf64_bfd_link_hash_table_create \
 733   _bfd_x86_elf_link_hash_table_create
 734 #define bfd_elf32_bfd_link_hash_table_create \
 735   _bfd_x86_elf_link_hash_table_create
 736 #define bfd_elf64_bfd_link_check_relocs \
 737   _bfd_x86_elf_link_check_relocs
 738 #define bfd_elf32_bfd_link_check_relocs \
 739   _bfd_x86_elf_link_check_relocs
 740
 741 #define elf_backend_size_dynamic_sections \
 742   _bfd_x86_elf_size_dynamic_sections
 743 #define elf_backend_always_size_sections \
 744   _bfd_x86_elf_always_size_sections
 745 #define elf_backend_merge_symbol_attribute \
 746   _bfd_x86_elf_merge_symbol_attribute
 747 #define elf_backend_copy_indirect_symbol \
 748   _bfd_x86_elf_copy_indirect_symbol
 749 #define elf_backend_fixup_symbol \
 750   _bfd_x86_elf_fixup_symbol
 751 #define elf_backend_hash_symbol \
 752   _bfd_x86_elf_hash_symbol
 753 #define elf_backend_adjust_dynamic_symbol \
 754   _bfd_x86_elf_adjust_dynamic_symbol
 755 #define elf_backend_gc_mark_hook \
 756   _bfd_x86_elf_gc_mark_hook
 757 #define elf_backend_omit_section_dynsym \
 758   _bfd_elf_omit_section_dynsym_all
 759 #define elf_backend_parse_gnu_properties \
 760   _bfd_x86_elf_parse_gnu_properties
 761 #define elf_backend_merge_gnu_properties \
 762   _bfd_x86_elf_merge_gnu_properties
 763 #define elf_backend_fixup_gnu_properties \
 764   _bfd_x86_elf_link_fixup_gnu_properties