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) \
 137          && !X86_SIZE_TYPE_P (R_TYPE)) \
 138          || ! SYMBOL_CALLS_LOCAL ((INFO), &(EH)->elf))) \
 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   /* Track dynamic relocs copied for this symbol.  */
 254   struct elf_dyn_relocs *dyn_relocs;
 255
 256   unsigned char tls_type;
 257
 258   /* Bit 0: Symbol has no GOT nor PLT relocations.
 259      Bit 1: Symbol has non-GOT/non-PLT relocations in text sections.
 260      zero_undefweak is initialized to 1 and undefined weak symbol
 261      should be resolved to 0 if zero_undefweak > 0.  */
 262   unsigned int zero_undefweak : 2;
 263
 264   /* Don't call finish_dynamic_symbol on this symbol.  */
 265   unsigned int no_finish_dynamic_symbol : 1;
 266
 267   /* TRUE if symbol is __tls_get_addr.  */
 268   unsigned int tls_get_addr : 1;
 269
 270   /* TRUE if symbol is defined as a protected symbol.  */
 271   unsigned int def_protected : 1;
 272
 273   /* 0: Symbol references are unknown.
 274      1: Symbol references aren't local.
 275      2: Symbol references are local.
 276    */
 277   unsigned int local_ref : 2;
 278
 279   /* TRUE if symbol is defined by linker.  */
 280   unsigned int linker_def : 1;
 281
 282   /* TRUE if symbol is referenced by R_386_GOTOFF relocation.  This is
 283      only used by i386.  */
 284   unsigned int gotoff_ref : 1;
 285
 286   /* TRUE if a weak symbol with a real definition needs a copy reloc.
 287      When there is a weak symbol with a real definition, the processor
 288      independent code will have arranged for us to see the real
 289      definition first.  We need to copy the needs_copy bit from the
 290      real definition and check it when allowing copy reloc in PIE.  This
 291      is only used by x86-64.  */
 292   unsigned int needs_copy : 1;
 293
 294   /* Information about the GOT PLT entry. Filled when there are both
 295      GOT and PLT relocations against the same function.  */
 296   union gotplt_union plt_got;
 297
 298   /* Information about the second PLT entry.   */
 299   union gotplt_union plt_second;
 300
 301   /* Offset of the GOTPLT entry reserved for the TLS descriptor,
 302      starting at the end of the jump table.  */
 303   bfd_vma tlsdesc_got;
 304 };
 305
 306 struct elf_x86_lazy_plt_layout
 307 {
 308   /* The first entry in a lazy procedure linkage table looks like this.  */
 309   const bfd_byte *plt0_entry;
 310   unsigned int plt0_entry_size;          /* Size of PLT0 entry.  */
 311
 312   /* Later entries in a lazy procedure linkage table look like this.  */
 313   const bfd_byte *plt_entry;
 314   unsigned int plt_entry_size;          /* Size of each PLT entry.  */
 315
 316   /* The TLSDESC entry in a lazy procedure linkage table looks like
 317      this.  This is for x86-64 only.  */
 318   const bfd_byte *plt_tlsdesc_entry;
 319   unsigned int plt_tlsdesc_entry_size;   /* Size of TLSDESC entry.  */
 320
 321   /* Offsets into the TLSDESC entry that are to be replaced with
 322      GOT+8 and GOT+TDG.  These are for x86-64 only.  */
 323   unsigned int plt_tlsdesc_got1_offset;
 324   unsigned int plt_tlsdesc_got2_offset;
 325
 326   /* Offset of the end of the PC-relative instructions containing
 327      plt_tlsdesc_got1_offset and plt_tlsdesc_got2_offset.  These
 328      are for x86-64 only.  */
 329   unsigned int plt_tlsdesc_got1_insn_end;
 330   unsigned int plt_tlsdesc_got2_insn_end;
 331
 332   /* Offsets into plt0_entry that are to be replaced with GOT[1] and
 333      GOT[2].  */
 334   unsigned int plt0_got1_offset;
 335   unsigned int plt0_got2_offset;
 336
 337   /* Offset of the end of the PC-relative instruction containing
 338      plt0_got2_offset.  This is for x86-64 only.  */
 339   unsigned int plt0_got2_insn_end;
 340
 341   /* Offsets into plt_entry that are to be replaced with...  */
 342   unsigned int plt_got_offset;    /* ... address of this symbol in .got. */
 343   unsigned int plt_reloc_offset;  /* ... offset into relocation table. */
 344   unsigned int plt_plt_offset;    /* ... offset to start of .plt. */
 345
 346   /* Length of the PC-relative instruction containing plt_got_offset.
 347      This is used for x86-64 only.  */
 348   unsigned int plt_got_insn_size;
 349
 350   /* Offset of the end of the PC-relative jump to plt0_entry.  This is
 351      used for x86-64 only.  */
 352   unsigned int plt_plt_insn_end;
 353
 354   /* Offset into plt_entry where the initial value of the GOT entry
 355      points.  */
 356   unsigned int plt_lazy_offset;
 357
 358   /* The first entry in a PIC lazy procedure linkage table looks like
 359      this.  */
 360   const bfd_byte *pic_plt0_entry;
 361
 362   /* Subsequent entries in a PIC lazy procedure linkage table look
 363      like this.  */
 364   const bfd_byte *pic_plt_entry;
 365
 366   /* .eh_frame covering the lazy .plt section.  */
 367   const bfd_byte *eh_frame_plt;
 368   unsigned int eh_frame_plt_size;
 369 };
 370
 371 struct elf_x86_non_lazy_plt_layout
 372 {
 373   /* Entries in a non-lazy procedure linkage table look like this.  */
 374   const bfd_byte *plt_entry;
 375   /* Entries in a PIC non-lazy procedure linkage table look like this.
 376      This is only used for i386 where absolute PLT and PIC PLT are
 377      different.  */
 378   const bfd_byte *pic_plt_entry;
 379
 380   unsigned int plt_entry_size;          /* Size of each PLT entry.  */
 381
 382   /* Offsets into plt_entry that are to be replaced with...  */
 383   unsigned int plt_got_offset;    /* ... address of this symbol in .got. */
 384
 385   /* Length of the PC-relative instruction containing plt_got_offset.
 386      This is used for x86-64 only.  */
 387   unsigned int plt_got_insn_size;
 388
 389   /* .eh_frame covering the non-lazy .plt section.  */
 390   const bfd_byte *eh_frame_plt;
 391   unsigned int eh_frame_plt_size;
 392 };
 393
 394 struct elf_x86_plt_layout
 395 {
 396   /* The first entry in a lazy procedure linkage table looks like this.  */
 397   const bfd_byte *plt0_entry;
 398   /* Entries in a procedure linkage table look like this.  */
 399   const bfd_byte *plt_entry;
 400   unsigned int plt_entry_size;          /* Size of each PLT entry.  */
 401
 402   /* 1 has PLT0.  */
 403   unsigned int has_plt0;
 404
 405   /* Offsets into plt_entry that are to be replaced with...  */
 406   unsigned int plt_got_offset;    /* ... address of this symbol in .got. */
 407
 408   /* Length of the PC-relative instruction containing plt_got_offset.
 409      This is only used for x86-64.  */
 410   unsigned int plt_got_insn_size;
 411
 412   /* Alignment of the .iplt section.  */
 413   unsigned int iplt_alignment;
 414
 415   /* .eh_frame covering the .plt section.  */
 416   const bfd_byte *eh_frame_plt;
 417   unsigned int eh_frame_plt_size;
 418 };
 419
 420 /* Values in tls_type of x86 ELF linker hash entry.  */
 421 #define GOT_UNKNOWN     0
 422 #define GOT_NORMAL      1
 423 #define GOT_TLS_GD      2
 424 #define GOT_TLS_IE      4
 425 #define GOT_TLS_IE_POS  5
 426 #define GOT_TLS_IE_NEG  6
 427 #define GOT_TLS_IE_BOTH 7
 428 #define GOT_TLS_GDESC   8
 429 #define GOT_ABS         9
 430 #define GOT_TLS_GD_BOTH_P(type) \
 431   ((type) == (GOT_TLS_GD | GOT_TLS_GDESC))
 432 #define GOT_TLS_GD_P(type) \
 433   ((type) == GOT_TLS_GD || GOT_TLS_GD_BOTH_P (type))
 434 #define GOT_TLS_GDESC_P(type) \
 435   ((type) == GOT_TLS_GDESC || GOT_TLS_GD_BOTH_P (type))
 436 #define GOT_TLS_GD_ANY_P(type) \
 437   (GOT_TLS_GD_P (type) || GOT_TLS_GDESC_P (type))
 438
 439 #define elf_x86_hash_entry(ent) \
 440   ((struct elf_x86_link_hash_entry *)(ent))
 441
 442 enum elf_x86_target_os
 443 {
 444   is_normal,
 445   is_solaris,
 446   is_vxworks,
 447   is_nacl
 448 };
 449
 450 /* x86 ELF linker hash table.  */
 451
 452 struct elf_x86_link_hash_table
 453 {
 454   struct elf_link_hash_table elf;
 455
 456   /* Short-cuts to get to dynamic linker sections.  */
 457   asection *interp;
 458   asection *plt_eh_frame;
 459   asection *plt_second;
 460   asection *plt_second_eh_frame;
 461   asection *plt_got;
 462   asection *plt_got_eh_frame;
 463
 464   /* Parameters describing PLT generation, lazy or non-lazy.  */
 465   struct elf_x86_plt_layout plt;
 466
 467   /* Parameters describing lazy PLT generation.  */
 468   const struct elf_x86_lazy_plt_layout *lazy_plt;
 469
 470   /* Parameters describing non-lazy PLT generation.  */
 471   const struct elf_x86_non_lazy_plt_layout *non_lazy_plt;
 472
 473   union
 474   {
 475     bfd_signed_vma refcount;
 476     bfd_vma offset;
 477   } tls_ld_or_ldm_got;
 478
 479   /* The amount of space used by the jump slots in the GOT.  */
 480   bfd_vma sgotplt_jump_table_size;
 481
 482   /* Small local sym cache.  */
 483   struct sym_cache sym_cache;
 484
 485   /* _TLS_MODULE_BASE_ symbol.  */
 486   struct bfd_link_hash_entry *tls_module_base;
 487
 488   /* Used by local STT_GNU_IFUNC symbols.  */
 489   htab_t loc_hash_table;
 490   void * loc_hash_memory;
 491
 492   /* The offset into sgot of the GOT entry used by the PLT entry
 493      above.  */
 494   bfd_vma tlsdesc_got;
 495
 496   /* The index of the next R_X86_64_JUMP_SLOT entry in .rela.plt.  */
 497   bfd_vma next_jump_slot_index;
 498   /* The index of the next R_X86_64_IRELATIVE entry in .rela.plt.  */
 499   bfd_vma next_irelative_index;
 500
 501   /* TRUE if there are dynamic relocs against IFUNC symbols that apply
 502      to read-only sections.  */
 503   bfd_boolean readonly_dynrelocs_against_ifunc;
 504
 505   /* The (unloaded but important) .rel.plt.unloaded section on VxWorks.
 506      This is used for i386 only.  */
 507   asection *srelplt2;
 508
 509   /* The index of the next unused R_386_TLS_DESC slot in .rel.plt.  This
 510      is only used for i386.  */
 511   bfd_vma next_tls_desc_index;
 512
 513   /* The offset into splt of the PLT entry for the TLS descriptor
 514      resolver.  Special values are 0, if not necessary (or not found
 515      to be necessary yet), and -1 if needed but not determined
 516      yet.  This is only used for x86-64.  */
 517   bfd_vma tlsdesc_plt;
 518
 519    /* Value used to fill the unused bytes of the first PLT entry.  This
 520       is only used for i386.  */
 521   bfd_byte plt0_pad_byte;
 522
 523   /* TRUE if GOT is referenced.  */
 524   unsigned int got_referenced : 1;
 525
 526   /* TRUE if PLT is PC-relative.  PLT in PDE and PC-relative PLT in PIE
 527      can be used as function address.
 528
 529      NB: i386 has non-PIC PLT and PIC PLT.  Only non-PIC PLT in PDE can
 530      be used as function address.  PIC PLT in PIE can't be used as
 531      function address.  */
 532   unsigned int pcrel_plt : 1;
 533
 534   bfd_vma (*r_info) (bfd_vma, bfd_vma);
 535   bfd_vma (*r_sym) (bfd_vma);
 536   bfd_boolean (*is_reloc_section) (const char *);
 537   enum elf_target_id target_id;
 538   enum elf_x86_target_os target_os;
 539   unsigned int sizeof_reloc;
 540   unsigned int dt_reloc;
 541   unsigned int dt_reloc_sz;
 542   unsigned int dt_reloc_ent;
 543   unsigned int got_entry_size;
 544   unsigned int pointer_r_type;
 545   int dynamic_interpreter_size;
 546   const char *dynamic_interpreter;
 547   const char *tls_get_addr;
 548
 549   /* Options passed from the linker.  */
 550   struct elf_linker_x86_params *params;
 551 };
 552
 553 /* Architecture-specific backend data for x86.  */
 554
 555 struct elf_x86_backend_data
 556 {
 557   /* Target system.  */
 558   enum elf_x86_target_os target_os;
 559 };
 560
 561 #define get_elf_x86_backend_data(abfd) \
 562   ((const struct elf_x86_backend_data *) \
 563    get_elf_backend_data (abfd)->arch_data)
 564
 565 struct elf_x86_init_table
 566 {
 567   /* The lazy PLT layout.  */
 568   const struct elf_x86_lazy_plt_layout *lazy_plt;
 569
 570   /* The non-lazy PLT layout.  */
 571   const struct elf_x86_non_lazy_plt_layout *non_lazy_plt;
 572
 573   /* The lazy PLT layout for IBT.  */
 574   const struct elf_x86_lazy_plt_layout *lazy_ibt_plt;
 575
 576   /* The non-lazy PLT layout for IBT.  */
 577   const struct elf_x86_non_lazy_plt_layout *non_lazy_ibt_plt;
 578
 579   bfd_byte plt0_pad_byte;
 580
 581   bfd_vma (*r_info) (bfd_vma, bfd_vma);
 582   bfd_vma (*r_sym) (bfd_vma);
 583 };
 584
 585 struct elf_x86_obj_tdata
 586 {
 587   struct elf_obj_tdata root;
 588
 589   /* tls_type for each local got entry.  */
 590   char *local_got_tls_type;
 591
 592   /* GOTPLT entries for TLS descriptors.  */
 593   bfd_vma *local_tlsdesc_gotent;
 594 };
 595
 596 enum elf_x86_plt_type
 597 {
 598   plt_non_lazy = 0,
 599   plt_lazy = 1 << 0,
 600   plt_pic = 1 << 1,
 601   plt_second = 1 << 2,
 602   plt_unknown = -1
 603 };
 604
 605 struct elf_x86_plt
 606 {
 607   const char *name;
 608   asection *sec;
 609   bfd_byte *contents;
 610   enum elf_x86_plt_type type;
 611   unsigned int plt_got_offset;
 612   unsigned int plt_entry_size;
 613   unsigned int plt_got_insn_size;       /* Only used for x86-64.  */
 614   long count;
 615 };
 616
 617 /* Set if a relocation is converted from a GOTPCREL relocation.  */
 618 #define R_X86_64_converted_reloc_bit (1 << 7)
 619
 620 #define elf_x86_tdata(abfd) \
 621   ((struct elf_x86_obj_tdata *) (abfd)->tdata.any)
 622
 623 #define elf_x86_local_got_tls_type(abfd) \
 624   (elf_x86_tdata (abfd)->local_got_tls_type)
 625
 626 #define elf_x86_local_tlsdesc_gotent(abfd) \
 627   (elf_x86_tdata (abfd)->local_tlsdesc_gotent)
 628
 629 #define elf_x86_compute_jump_table_size(htab) \
 630   ((htab)->elf.srelplt->reloc_count * (htab)->got_entry_size)
 631
 632 #define is_x86_elf(bfd, htab)                           \
 633   (bfd_get_flavour (bfd) == bfd_target_elf_flavour      \
 634    && elf_tdata (bfd) != NULL                           \
 635    && elf_object_id (bfd) == (htab)->target_id)
 636
 637 extern bfd_boolean _bfd_x86_elf_mkobject
 638   (bfd *);
 639
 640 extern void _bfd_x86_elf_set_tls_module_base
 641   (struct bfd_link_info *);
 642
 643 extern bfd_vma _bfd_x86_elf_dtpoff_base
 644   (struct bfd_link_info *);
 645
 646 extern bfd_boolean _bfd_x86_elf_readonly_dynrelocs
 647   (struct elf_link_hash_entry *, void *);
 648
 649 extern struct elf_link_hash_entry * _bfd_elf_x86_get_local_sym_hash
 650   (struct elf_x86_link_hash_table *, bfd *, const Elf_Internal_Rela *,
 651    bfd_boolean);
 652
 653 extern hashval_t _bfd_x86_elf_local_htab_hash
 654   (const void *);
 655
 656 extern int _bfd_x86_elf_local_htab_eq
 657   (const void *, const void *);
 658
 659 extern struct bfd_hash_entry * _bfd_x86_elf_link_hash_newfunc
 660   (struct bfd_hash_entry *, struct bfd_hash_table *, const char *);
 661
 662 extern struct bfd_link_hash_table * _bfd_x86_elf_link_hash_table_create
 663   (bfd *);
 664
 665 extern int _bfd_x86_elf_compare_relocs
 666   (const void *, const void *);
 667
 668 extern bfd_boolean _bfd_x86_elf_link_check_relocs
 669   (bfd *, struct bfd_link_info *);
 670
 671 extern bfd_boolean _bfd_elf_x86_valid_reloc_p
 672   (asection *, struct bfd_link_info *, struct elf_x86_link_hash_table *,
 673    const Elf_Internal_Rela *, struct elf_link_hash_entry *,
 674    Elf_Internal_Sym *, Elf_Internal_Shdr *, bfd_boolean *);
 675
 676 extern bfd_boolean _bfd_x86_elf_size_dynamic_sections
 677   (bfd *, struct bfd_link_info *);
 678
 679 extern struct elf_x86_link_hash_table *_bfd_x86_elf_finish_dynamic_sections
 680   (bfd *, struct bfd_link_info *);
 681
 682 extern bfd_boolean _bfd_x86_elf_always_size_sections
 683   (bfd *, struct bfd_link_info *);
 684
 685 extern void _bfd_x86_elf_merge_symbol_attribute
 686   (struct elf_link_hash_entry *, const Elf_Internal_Sym *,
 687    bfd_boolean, bfd_boolean);
 688
 689 extern void _bfd_x86_elf_copy_indirect_symbol
 690   (struct bfd_link_info *, struct elf_link_hash_entry *,
 691    struct elf_link_hash_entry *);
 692
 693 extern bfd_boolean _bfd_x86_elf_fixup_symbol
 694   (struct bfd_link_info *, struct elf_link_hash_entry *);
 695
 696 extern bfd_boolean _bfd_x86_elf_hash_symbol
 697   (struct elf_link_hash_entry *);
 698
 699 extern bfd_boolean _bfd_x86_elf_adjust_dynamic_symbol
 700   (struct bfd_link_info *, struct elf_link_hash_entry *);
 701
 702 extern void _bfd_x86_elf_hide_symbol
 703   (struct bfd_link_info *, struct elf_link_hash_entry *, bfd_boolean);
 704
 705 extern bfd_boolean _bfd_x86_elf_link_symbol_references_local
 706   (struct bfd_link_info *, struct elf_link_hash_entry *);
 707
 708 extern asection * _bfd_x86_elf_gc_mark_hook
 709   (asection *, struct bfd_link_info *, Elf_Internal_Rela *,
 710    struct elf_link_hash_entry *, Elf_Internal_Sym *);
 711
 712 extern long _bfd_x86_elf_get_synthetic_symtab
 713   (bfd *, long, long, bfd_vma, struct elf_x86_plt [], asymbol **,
 714    asymbol **);
 715
 716 extern enum elf_property_kind _bfd_x86_elf_parse_gnu_properties
 717   (bfd *, unsigned int, bfd_byte *, unsigned int);
 718
 719 extern bfd_boolean _bfd_x86_elf_merge_gnu_properties
 720   (struct bfd_link_info *, bfd *, bfd *, elf_property *, elf_property *);
 721
 722 extern void _bfd_x86_elf_link_fixup_gnu_properties
 723   (struct bfd_link_info *, elf_property_list **);
 724
 725 extern bfd * _bfd_x86_elf_link_setup_gnu_properties
 726   (struct bfd_link_info *, struct elf_x86_init_table *);
 727
 728 extern void _bfd_x86_elf_link_fixup_ifunc_symbol
 729   (struct bfd_link_info *, struct elf_x86_link_hash_table *,
 730    struct elf_link_hash_entry *, Elf_Internal_Sym *sym);
 731
 732 #define bfd_elf64_mkobject \
 733   _bfd_x86_elf_mkobject
 734 #define bfd_elf32_mkobject \
 735   _bfd_x86_elf_mkobject
 736 #define bfd_elf64_bfd_link_hash_table_create \
 737   _bfd_x86_elf_link_hash_table_create
 738 #define bfd_elf32_bfd_link_hash_table_create \
 739   _bfd_x86_elf_link_hash_table_create
 740 #define bfd_elf64_bfd_link_check_relocs \
 741   _bfd_x86_elf_link_check_relocs
 742 #define bfd_elf32_bfd_link_check_relocs \
 743   _bfd_x86_elf_link_check_relocs
 744
 745 #define elf_backend_size_dynamic_sections \
 746   _bfd_x86_elf_size_dynamic_sections
 747 #define elf_backend_always_size_sections \
 748   _bfd_x86_elf_always_size_sections
 749 #define elf_backend_merge_symbol_attribute \
 750   _bfd_x86_elf_merge_symbol_attribute
 751 #define elf_backend_copy_indirect_symbol \
 752   _bfd_x86_elf_copy_indirect_symbol
 753 #define elf_backend_fixup_symbol \
 754   _bfd_x86_elf_fixup_symbol
 755 #define elf_backend_hash_symbol \
 756   _bfd_x86_elf_hash_symbol
 757 #define elf_backend_adjust_dynamic_symbol \
 758   _bfd_x86_elf_adjust_dynamic_symbol
 759 #define elf_backend_gc_mark_hook \
 760   _bfd_x86_elf_gc_mark_hook
 761 #define elf_backend_omit_section_dynsym \
 762   _bfd_elf_omit_section_dynsym_all
 763 #define elf_backend_parse_gnu_properties \
 764   _bfd_x86_elf_parse_gnu_properties
 765 #define elf_backend_merge_gnu_properties \
 766   _bfd_x86_elf_merge_gnu_properties
 767 #define elf_backend_fixup_gnu_properties \
 768   _bfd_x86_elf_link_fixup_gnu_properties