bfd/elfxx-x86.h

   1 /* x86 specific support for ELF
   2    Copyright (C) 2017-2022 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 /* Don't generate unused section symbols.  */
  22 #define TARGET_KEEP_UNUSED_SECTION_SYMBOLS false
  23
  24 #include "sysdep.h"
  25 #include "bfd.h"
  26 #include "bfdlink.h"
  27 #include "libbfd.h"
  28 #include "elf-bfd.h"
  29 #include "hashtab.h"
  30 #include "elf-linker-x86.h"
  31 #include "elf/i386.h"
  32 #include "elf/x86-64.h"
  33
  34 #define X86_64_PCREL_TYPE_P(TYPE) \
  35   ((TYPE) == R_X86_64_PC8 \
  36    || (TYPE) == R_X86_64_PC16 \
  37    || (TYPE) == R_X86_64_PC32 \
  38    || (TYPE) == R_X86_64_PC32_BND \
  39    || (TYPE) == R_X86_64_PC64)
  40 #define I386_PCREL_TYPE_P(TYPE) ((TYPE) == R_386_PC32)
  41 #define X86_PCREL_TYPE_P(IS_X86_64, TYPE) \
  42   ((IS_X86_64) ? X86_64_PCREL_TYPE_P (TYPE) : I386_PCREL_TYPE_P (TYPE))
  43
  44 #define X86_64_SIZE_TYPE_P(TYPE) \
  45   ((TYPE) == R_X86_64_SIZE32 || (TYPE) == R_X86_64_SIZE64)
  46 #define I386_SIZE_TYPE_P(TYPE) ((TYPE) == R_386_SIZE32)
  47 #define X86_SIZE_TYPE_P(IS_X86_64, TYPE) \
  48   ((IS_X86_64) ? X86_64_SIZE_TYPE_P(TYPE) : I386_SIZE_TYPE_P (TYPE))
  49
  50 #define X86_64_GOT_TYPE_P(TYPE) \
  51   ((TYPE) == R_X86_64_GOTPCREL \
  52    || (TYPE) == R_X86_64_GOTPCRELX \
  53    || (TYPE) == R_X86_64_REX_GOTPCRELX \
  54    || (TYPE) == R_X86_64_GOT32 \
  55    || (TYPE) == R_X86_64_GOT64 \
  56    || (TYPE) == R_X86_64_GOTPCREL64 \
  57    || (TYPE) == R_X86_64_GOTPLT64)
  58 #define I386_GOT_TYPE_P(TYPE) \
  59   ((TYPE) == R_386_GOT32 || (TYPE) == R_386_GOT32X)
  60 #define X86_GOT_TYPE_P(IS_X86_64, TYPE) \
  61   ((IS_X86_64) ? X86_64_GOT_TYPE_P (TYPE) : I386_GOT_TYPE_P (TYPE))
  62
  63 #define X86_64_RELATIVE_RELOC_TYPE_P(TYPE) \
  64   (X86_64_PCREL_TYPE_P (TYPE) \
  65    || (TYPE) == R_X86_64_8 \
  66    || (TYPE) == R_X86_64_16 \
  67    || (TYPE) == R_X86_64_32 \
  68    || (TYPE) == R_X86_64_32S \
  69    || (TYPE) == R_X86_64_64)
  70 #define I386_RELATIVE_RELOC_TYPE_P(TYPE) \
  71   ((TYPE) == R_386_32 || (TYPE) == R_386_PC32)
  72 #define X86_RELATIVE_RELOC_TYPE_P(IS_X86_64, TYPE) \
  73   ((IS_X86_64) \
  74    ? X86_64_RELATIVE_RELOC_TYPE_P (TYPE) \
  75    : I386_RELATIVE_RELOC_TYPE_P(TYPE))
  76
  77 #define X86_64_NEED_DYNAMIC_RELOC_TYPE_P(TYPE) \
  78   (X86_64_SIZE_TYPE_P (TYPE) \
  79    || X86_64_RELATIVE_RELOC_TYPE_P (TYPE))
  80 #define I386_NEED_DYNAMIC_RELOC_TYPE_P(TYPE) \
  81   (I386_SIZE_TYPE_P (TYPE) \
  82    || I386_RELATIVE_RELOC_TYPE_P (TYPE) \
  83    || (TYPE) == R_386_TLS_IE \
  84    || (TYPE) == R_386_TLS_LE \
  85    || (TYPE) == R_386_TLS_LE_32)
  86 #define X86_NEED_DYNAMIC_RELOC_TYPE_P(IS_X86_64, TYPE) \
  87   ((IS_X86_64) \
  88    ? X86_64_NEED_DYNAMIC_RELOC_TYPE_P (TYPE) \
  89    : I386_NEED_DYNAMIC_RELOC_TYPE_P (TYPE))
  90
  91 #define X86_LOCAL_GOT_RELATIVE_RELOC_P(IS_X86_64, INFO, SYM) \
  92   (bfd_link_pic (INFO) \
  93    && (!(IS_X86_64) || ((SYM) != NULL && (SYM)->st_shndx != SHN_ABS)))
  94
  95 #define PLT_CIE_LENGTH          20
  96 #define PLT_FDE_LENGTH          36
  97 #define PLT_FDE_START_OFFSET    4 + PLT_CIE_LENGTH + 8
  98 #define PLT_FDE_LEN_OFFSET      4 + PLT_CIE_LENGTH + 12
  99
 100 #define I386_PCREL_TYPE_P(TYPE) ((TYPE) == R_386_PC32)
 101 #define X86_64_PCREL_TYPE_P(TYPE) \
 102   ((TYPE) == R_X86_64_PC8 \
 103    || (TYPE) == R_X86_64_PC16 \
 104    || (TYPE) == R_X86_64_PC32 \
 105    || (TYPE) == R_X86_64_PC32_BND \
 106    || (TYPE) == R_X86_64_PC64)
 107
 108 #define ABI_64_P(abfd) \
 109   (get_elf_backend_data (abfd)->s->elfclass == ELFCLASS64)
 110
 111 /* If ELIMINATE_COPY_RELOCS is non-zero, the linker will try to avoid
 112    copying dynamic variables from a shared lib into an app's dynbss
 113    section, and instead use a dynamic relocation to point into the
 114    shared lib.  */
 115 #define ELIMINATE_COPY_RELOCS 1
 116
 117 #define elf_x86_hash_table(p, id) \
 118   (is_elf_hash_table ((p)->hash) \
 119    && elf_hash_table_id ((struct elf_link_hash_table *) ((p)->hash)) == (id) \
 120     ? ((struct elf_x86_link_hash_table *) ((p)->hash)) : NULL)
 121
 122 /* Will references to this symbol always be local in this object?  */
 123 #define SYMBOL_REFERENCES_LOCAL_P(INFO, H) \
 124   _bfd_x86_elf_link_symbol_references_local ((INFO), (H))
 125
 126 /* TRUE if an undefined weak symbol should be resolved to 0.  Local
 127    undefined weak symbol is always resolved to 0.  Reference to an
 128    undefined weak symbol is resolved to 0 in executable if undefined
 129    weak symbol should be resolved to 0 (zero_undefweak > 0).  */
 130 #define UNDEFINED_WEAK_RESOLVED_TO_ZERO(INFO, EH) \
 131   ((EH)->elf.root.type == bfd_link_hash_undefweak                \
 132    && (SYMBOL_REFERENCES_LOCAL_P ((INFO), &(EH)->elf)            \
 133        || (bfd_link_executable (INFO)                            \
 134            && (EH)->zero_undefweak > 0)))
 135
 136 /* Should copy relocation be generated for a symbol.  Don't generate
 137    copy relocation against a protected symbol defined in a shared
 138    object.  */
 139 #define SYMBOL_NO_COPYRELOC(INFO, EH) \
 140   ((EH)->def_protected \
 141    && ((EH)->elf.root.type == bfd_link_hash_defined \
 142        || (EH)->elf.root.type == bfd_link_hash_defweak) \
 143    && ((EH)->elf.root.u.def.section->owner->flags & DYNAMIC) != 0 \
 144    && ((EH)->elf.root.u.def.section->flags & SEC_CODE) == 0)
 145
 146 /* TRUE if dynamic relocation is needed.  If we are creating a shared
 147    library, and this is a reloc against a global symbol, or a non PC
 148    relative reloc against a local symbol, then we need to copy the reloc
 149    into the shared library.  However, if we are linking with -Bsymbolic,
 150    we do not need to copy a reloc against a global symbol which is
 151    defined in an object we are including in the link (i.e., DEF_REGULAR
 152    is set).
 153
 154    If PCREL_PLT is true, don't generate dynamic relocation in PIE for
 155    PC-relative relocation against a dynamic function definition in data
 156    section when PLT address can be used.
 157
 158    If on the other hand, we are creating an executable, we may need to
 159    keep relocations for symbols satisfied by a dynamic library if we
 160    manage to avoid copy relocs for the symbol.
 161
 162    We also need to generate dynamic pointer relocation against
 163    STT_GNU_IFUNC symbol in the non-code section.  */
 164 #define NEED_DYNAMIC_RELOCATION_P(IS_X86_64, INFO, PCREL_PLT, H, SEC, \
 165                                   R_TYPE, POINTER_TYPE) \
 166   ((bfd_link_pic (INFO) \
 167     && (! X86_PCREL_TYPE_P (IS_X86_64, R_TYPE) \
 168         || ((H) != NULL \
 169             && (! (bfd_link_pie (INFO) \
 170                    || SYMBOLIC_BIND ((INFO), (H))) \
 171                 || (H)->root.type == bfd_link_hash_defweak \
 172                 || (!(bfd_link_pie (INFO) \
 173                       && (PCREL_PLT) \
 174                       && (H)->plt.refcount > 0 \
 175                       && ((SEC)->flags & SEC_CODE) == 0 \
 176                       && (H)->type == STT_FUNC \
 177                       && (H)->def_dynamic) \
 178                     && !(H)->def_regular))))) \
 179    || ((H) != NULL \
 180        && (H)->type == STT_GNU_IFUNC \
 181        && (R_TYPE) == POINTER_TYPE \
 182        && ((SEC)->flags & SEC_CODE) == 0) \
 183    || (ELIMINATE_COPY_RELOCS \
 184        && !bfd_link_pic (INFO) \
 185        && (H) != NULL \
 186        && ((H)->root.type == bfd_link_hash_defweak \
 187            || !(H)->def_regular)))
 188
 189 /* TRUE if dynamic relocation should be generated.  Don't copy a
 190    pc-relative relocation into the output file if the symbol needs
 191    copy reloc or the symbol is undefined when building executable.
 192    Copy dynamic function pointer relocations.  Don't generate dynamic
 193    relocations against resolved undefined weak symbols in PIE, except
 194    when PC32_RELOC is TRUE.  Undefined weak symbol is bound locally
 195    when PIC is false.  Don't generate dynamic relocations against
 196    non-preemptible absolute symbol.  NB: rel_from_abs is set on symbols
 197    defined by linker scripts from "dot" (also SEGMENT_START or ORIGIN)
 198    outside of an output section statement, which will be converted from
 199    absolute to section-relative in set_sym_sections called from
 200    ldexp_finalize_syms after ldemul_finish.   */
 201 #define GENERATE_DYNAMIC_RELOCATION_P(IS_X86_64, INFO, EH, R_TYPE, \
 202                                       SEC, NEED_COPY_RELOC_IN_PIE, \
 203                                       RESOLVED_TO_ZERO, PC32_RELOC) \
 204   ((bfd_link_pic (INFO) \
 205     && !(bfd_is_abs_section (SEC) \
 206          && ((EH) == NULL \
 207              || (EH)->elf.root.rel_from_abs == 0) \
 208          && ((EH) == NULL \
 209              || SYMBOL_REFERENCES_LOCAL (INFO, &(EH)->elf))) \
 210     && !(NEED_COPY_RELOC_IN_PIE) \
 211     && ((EH) == NULL \
 212         || ((ELF_ST_VISIBILITY ((EH)->elf.other) == STV_DEFAULT \
 213              && (!(RESOLVED_TO_ZERO) || PC32_RELOC)) \
 214             || (EH)->elf.root.type != bfd_link_hash_undefweak)) \
 215     && ((!X86_PCREL_TYPE_P (IS_X86_64, R_TYPE) \
 216          && !X86_SIZE_TYPE_P (IS_X86_64, R_TYPE)) \
 217         || ! SYMBOL_CALLS_LOCAL ((INFO), \
 218                                  (struct elf_link_hash_entry *) (EH)))) \
 219    || (ELIMINATE_COPY_RELOCS \
 220        && !bfd_link_pic (INFO) \
 221        && (EH) != NULL \
 222        && (EH)->elf.dynindx != -1 \
 223        && (!(EH)->elf.non_got_ref \
 224            || ((EH)->elf.root.type == bfd_link_hash_undefweak \
 225                && !(RESOLVED_TO_ZERO))) \
 226                && (((EH)->elf.def_dynamic && !(EH)->elf.def_regular) \
 227                    || (EH)->elf.root.type == bfd_link_hash_undefined)))
 228
 229 /* TRUE if this input relocation should be copied to output.  H->dynindx
 230    may be -1 if this symbol was marked to become local.  */
 231 #define COPY_INPUT_RELOC_P(IS_X86_64, INFO, H, R_TYPE) \
 232   ((H) != NULL \
 233    && (H)->dynindx != -1 \
 234    && (X86_PCREL_TYPE_P (IS_X86_64, R_TYPE) \
 235        || !(bfd_link_executable (INFO) || SYMBOLIC_BIND ((INFO), (H))) \
 236        || !(H)->def_regular))
 237
 238 /* TRUE if this is actually a static link, or it is a -Bsymbolic link
 239    and the symbol is defined locally, or the symbol was forced to be
 240    local because of a version file.  */
 241 #define RESOLVED_LOCALLY_P(INFO, H, HTAB) \
 242   (!WILL_CALL_FINISH_DYNAMIC_SYMBOL ((HTAB)->elf.dynamic_sections_created, \
 243                                      bfd_link_pic (INFO), (H)) \
 244    || (bfd_link_pic (INFO) \
 245        && SYMBOL_REFERENCES_LOCAL_P ((INFO), (H))) \
 246        || (ELF_ST_VISIBILITY ((H)->other) \
 247            && (H)->root.type == bfd_link_hash_undefweak))
 248
 249 /* TRUE if this symbol isn't defined by a shared object.  */
 250 #define SYMBOL_DEFINED_NON_SHARED_P(H) \
 251   ((H)->def_regular \
 252    || (H)->root.linker_def \
 253    || (H)->root.ldscript_def \
 254    || ((struct elf_x86_link_hash_entry *) (H))->linker_def \
 255    || ELF_COMMON_DEF_P (H))
 256
 257 /* Return TRUE if the symbol described by a linker hash entry H is
 258    going to be absolute.  Similar to bfd_is_abs_symbol, but excluding
 259    all linker-script defined symbols.  */
 260 #define ABS_SYMBOL_P(H) \
 261   (bfd_is_abs_symbol (&(H)->root) && !(H)->root.ldscript_def)
 262
 263 /* TRUE if relative relocation should be generated.  GOT reference to
 264    global symbol in PIC will lead to dynamic symbol.  It becomes a
 265    problem when "time" or "times" is defined as a variable in an
 266    executable, clashing with functions of the same name in libc.  If a
 267    symbol isn't undefined weak symbol, don't make it dynamic in PIC and
 268    generate relative relocation.   Don't generate relative relocation
 269    against non-preemptible absolute symbol.  */
 270 #define GENERATE_RELATIVE_RELOC_P(INFO, H) \
 271   ((H)->dynindx == -1 \
 272    && !(H)->forced_local \
 273    && (H)->root.type != bfd_link_hash_undefweak \
 274    && bfd_link_pic (INFO) \
 275    && !ABS_SYMBOL_P (H))
 276
 277 /* TRUE if this is a pointer reference to a local IFUNC.  */
 278 #define POINTER_LOCAL_IFUNC_P(INFO, H) \
 279   ((H)->dynindx == -1 \
 280    || (H)->forced_local \
 281    || bfd_link_executable (INFO))
 282
 283 /* TRUE if this is a PLT reference to a local IFUNC.  */
 284 #define PLT_LOCAL_IFUNC_P(INFO, H) \
 285   ((H)->dynindx == -1 \
 286    || ((bfd_link_executable (INFO) \
 287         || ELF_ST_VISIBILITY ((H)->other) != STV_DEFAULT) \
 288         && (H)->def_regular \
 289         && (H)->type == STT_GNU_IFUNC))
 290
 291 /* TRUE if TLS IE->LE transition is OK.  */
 292 #define TLS_TRANSITION_IE_TO_LE_P(INFO, H, TLS_TYPE) \
 293   (bfd_link_executable (INFO) \
 294    && (H) != NULL \
 295    && (H)->dynindx == -1 \
 296    && (TLS_TYPE & GOT_TLS_IE))
 297
 298 /* Verify that the symbol has an entry in the procedure linkage table.  */
 299 #define VERIFY_PLT_ENTRY(INFO, H, PLT, GOTPLT, RELPLT, LOCAL_UNDEFWEAK) \
 300   do \
 301     { \
 302       if (((H)->dynindx == -1 \
 303            && !LOCAL_UNDEFWEAK \
 304            && !(((H)->forced_local || bfd_link_executable (INFO)) \
 305                 && (H)->def_regular \
 306                 && (H)->type == STT_GNU_IFUNC)) \
 307           || (PLT) == NULL \
 308           || (GOTPLT) == NULL \
 309           || (RELPLT) == NULL) \
 310         abort (); \
 311     } \
 312   while (0);
 313
 314 /* Verify that the symbol supports copy relocation.  */
 315 #define VERIFY_COPY_RELOC(H, HTAB) \
 316   do \
 317     { \
 318       if ((H)->dynindx == -1 \
 319           || ((H)->root.type != bfd_link_hash_defined \
 320               && (H)->root.type != bfd_link_hash_defweak) \
 321           || (HTAB)->elf.srelbss == NULL \
 322           || (HTAB)->elf.sreldynrelro == NULL) \
 323         abort (); \
 324     } \
 325   while (0);
 326
 327 /* x86 ELF linker hash entry.  */
 328
 329 struct elf_x86_link_hash_entry
 330 {
 331   struct elf_link_hash_entry elf;
 332
 333   unsigned char tls_type;
 334
 335   /* Bit 0: Symbol has no GOT nor PLT relocations.
 336      Bit 1: Symbol has non-GOT/non-PLT relocations in text sections.
 337      zero_undefweak is initialized to 1 and undefined weak symbol
 338      should be resolved to 0 if zero_undefweak > 0.  */
 339   unsigned int zero_undefweak : 2;
 340
 341   /* Don't call finish_dynamic_symbol on this symbol.  */
 342   unsigned int no_finish_dynamic_symbol : 1;
 343
 344   /* R_*_RELATIVE relocation in GOT for this symbol has been
 345      processed.  */
 346   unsigned int got_relative_reloc_done : 1;
 347
 348   /* TRUE if symbol is __tls_get_addr.  */
 349   unsigned int tls_get_addr : 1;
 350
 351   /* TRUE if symbol is defined as a protected symbol.  */
 352   unsigned int def_protected : 1;
 353
 354   /* 0: Symbol references are unknown.
 355      1: Symbol references aren't local.
 356      2: Symbol references are local.
 357    */
 358   unsigned int local_ref : 2;
 359
 360   /* TRUE if symbol is defined by linker.  */
 361   unsigned int linker_def : 1;
 362
 363   /* TRUE if symbol is referenced by a non-GOT/non-PLT relocation in a
 364      relocatable object file without indirect external access marker.  */
 365   unsigned int non_got_ref_without_indirect_extern_access : 1;
 366
 367   /* TRUE if symbol is referenced by R_386_GOTOFF relocation.  This is
 368      only used by i386.  */
 369   unsigned int gotoff_ref : 1;
 370
 371   /* TRUE if a weak symbol with a real definition needs a copy reloc.
 372      When there is a weak symbol with a real definition, the processor
 373      independent code will have arranged for us to see the real
 374      definition first.  We need to copy the needs_copy bit from the
 375      real definition and check it when allowing copy reloc in PIE.  This
 376      is only used by x86-64.  */
 377   unsigned int needs_copy : 1;
 378
 379   /* Information about the GOT PLT entry. Filled when there are both
 380      GOT and PLT relocations against the same function.  */
 381   union gotplt_union plt_got;
 382
 383   /* Information about the second PLT entry.   */
 384   union gotplt_union plt_second;
 385
 386   /* Offset of the GOTPLT entry reserved for the TLS descriptor,
 387      starting at the end of the jump table.  */
 388   bfd_vma tlsdesc_got;
 389 };
 390
 391 struct elf_x86_lazy_plt_layout
 392 {
 393   /* The first entry in a lazy procedure linkage table looks like this.  */
 394   const bfd_byte *plt0_entry;
 395   unsigned int plt0_entry_size;          /* Size of PLT0 entry.  */
 396
 397   /* Later entries in a lazy procedure linkage table look like this.  */
 398   const bfd_byte *plt_entry;
 399   unsigned int plt_entry_size;          /* Size of each PLT entry.  */
 400
 401   /* The TLSDESC entry in a lazy procedure linkage table looks like
 402      this.  This is for x86-64 only.  */
 403   const bfd_byte *plt_tlsdesc_entry;
 404   unsigned int plt_tlsdesc_entry_size;   /* Size of TLSDESC entry.  */
 405
 406   /* Offsets into the TLSDESC entry that are to be replaced with
 407      GOT+8 and GOT+TDG.  These are for x86-64 only.  */
 408   unsigned int plt_tlsdesc_got1_offset;
 409   unsigned int plt_tlsdesc_got2_offset;
 410
 411   /* Offset of the end of the PC-relative instructions containing
 412      plt_tlsdesc_got1_offset and plt_tlsdesc_got2_offset.  These
 413      are for x86-64 only.  */
 414   unsigned int plt_tlsdesc_got1_insn_end;
 415   unsigned int plt_tlsdesc_got2_insn_end;
 416
 417   /* Offsets into plt0_entry that are to be replaced with GOT[1] and
 418      GOT[2].  */
 419   unsigned int plt0_got1_offset;
 420   unsigned int plt0_got2_offset;
 421
 422   /* Offset of the end of the PC-relative instruction containing
 423      plt0_got2_offset.  This is for x86-64 only.  */
 424   unsigned int plt0_got2_insn_end;
 425
 426   /* Offsets into plt_entry that are to be replaced with...  */
 427   unsigned int plt_got_offset;    /* ... address of this symbol in .got. */
 428   unsigned int plt_reloc_offset;  /* ... offset into relocation table. */
 429   unsigned int plt_plt_offset;    /* ... offset to start of .plt. */
 430
 431   /* Length of the PC-relative instruction containing plt_got_offset.
 432      This is used for x86-64 only.  */
 433   unsigned int plt_got_insn_size;
 434
 435   /* Offset of the end of the PC-relative jump to plt0_entry.  This is
 436      used for x86-64 only.  */
 437   unsigned int plt_plt_insn_end;
 438
 439   /* Offset into plt_entry where the initial value of the GOT entry
 440      points.  */
 441   unsigned int plt_lazy_offset;
 442
 443   /* The first entry in a PIC lazy procedure linkage table looks like
 444      this.  */
 445   const bfd_byte *pic_plt0_entry;
 446
 447   /* Subsequent entries in a PIC lazy procedure linkage table look
 448      like this.  */
 449   const bfd_byte *pic_plt_entry;
 450
 451   /* .eh_frame covering the lazy .plt section.  */
 452   const bfd_byte *eh_frame_plt;
 453   unsigned int eh_frame_plt_size;
 454 };
 455
 456 struct elf_x86_non_lazy_plt_layout
 457 {
 458   /* Entries in a non-lazy procedure linkage table look like this.  */
 459   const bfd_byte *plt_entry;
 460   /* Entries in a PIC non-lazy procedure linkage table look like this.
 461      This is only used for i386 where absolute PLT and PIC PLT are
 462      different.  */
 463   const bfd_byte *pic_plt_entry;
 464
 465   unsigned int plt_entry_size;          /* Size of each PLT entry.  */
 466
 467   /* Offsets into plt_entry that are to be replaced with...  */
 468   unsigned int plt_got_offset;    /* ... address of this symbol in .got. */
 469
 470   /* Length of the PC-relative instruction containing plt_got_offset.
 471      This is used for x86-64 only.  */
 472   unsigned int plt_got_insn_size;
 473
 474   /* .eh_frame covering the non-lazy .plt section.  */
 475   const bfd_byte *eh_frame_plt;
 476   unsigned int eh_frame_plt_size;
 477 };
 478
 479 struct elf_x86_plt_layout
 480 {
 481   /* The first entry in a lazy procedure linkage table looks like this.  */
 482   const bfd_byte *plt0_entry;
 483   /* Entries in a procedure linkage table look like this.  */
 484   const bfd_byte *plt_entry;
 485   unsigned int plt_entry_size;          /* Size of each PLT entry.  */
 486
 487   /* 1 has PLT0.  */
 488   unsigned int has_plt0;
 489
 490   /* Offsets into plt_entry that are to be replaced with...  */
 491   unsigned int plt_got_offset;    /* ... address of this symbol in .got. */
 492
 493   /* Length of the PC-relative instruction containing plt_got_offset.
 494      This is only used for x86-64.  */
 495   unsigned int plt_got_insn_size;
 496
 497   /* Alignment of the .iplt section.  */
 498   unsigned int iplt_alignment;
 499
 500   /* .eh_frame covering the .plt section.  */
 501   const bfd_byte *eh_frame_plt;
 502   unsigned int eh_frame_plt_size;
 503 };
 504
 505 /* Values in tls_type of x86 ELF linker hash entry.  */
 506 #define GOT_UNKNOWN     0
 507 #define GOT_NORMAL      1
 508 #define GOT_TLS_GD      2
 509 #define GOT_TLS_IE      4
 510 #define GOT_TLS_IE_POS  5
 511 #define GOT_TLS_IE_NEG  6
 512 #define GOT_TLS_IE_BOTH 7
 513 #define GOT_TLS_GDESC   8
 514 #define GOT_ABS         9
 515 #define GOT_TLS_GD_BOTH_P(type) \
 516   ((type) == (GOT_TLS_GD | GOT_TLS_GDESC))
 517 #define GOT_TLS_GD_P(type) \
 518   ((type) == GOT_TLS_GD || GOT_TLS_GD_BOTH_P (type))
 519 #define GOT_TLS_GDESC_P(type) \
 520   ((type) == GOT_TLS_GDESC || GOT_TLS_GD_BOTH_P (type))
 521 #define GOT_TLS_GD_ANY_P(type) \
 522   (GOT_TLS_GD_P (type) || GOT_TLS_GDESC_P (type))
 523
 524 #define elf_x86_hash_entry(ent) \
 525   ((struct elf_x86_link_hash_entry *)(ent))
 526
 527 /* Information of an input relocation used to compute its contribution
 528    to the DT_RELR section size.  */
 529
 530 struct elf_x86_relative_reloc_record
 531 {
 532   /* The original relocation info.  */
 533   Elf_Internal_Rela rel;
 534   /* The input or the GOT section where the relocation is applied.  */
 535   asection *sec;
 536   /* Local symbol info.  NULL for global symbol.  */
 537   Elf_Internal_Sym *sym;
 538   union
 539     {
 540       /* Section where the local symbol is defined.  */
 541       asection *sym_sec;
 542       /* Global symbol hash.  */
 543       struct elf_link_hash_entry *h;
 544     } u;
 545   /* The offset into the output section where the relative relocation
 546      will be applied at run-time.  */
 547   bfd_vma offset;
 548   /* The run-time address.  */
 549   bfd_vma address;
 550 };
 551
 552 struct elf_x86_relative_reloc_data
 553 {
 554   bfd_size_type count;
 555   bfd_size_type size;
 556   struct elf_x86_relative_reloc_record *data;
 557 };
 558
 559 /* DT_RELR bitmap.  */
 560 struct elf_dt_relr_bitmap
 561 {
 562   bfd_size_type count;
 563   bfd_size_type size;
 564   union
 565     {
 566       /* 32-bit bitmap.  */
 567       uint32_t *elf32;
 568       /* 64-bit bitmap.  */
 569       uint64_t *elf64;
 570     } u;
 571 };
 572
 573 /* x86 ELF linker hash table.  */
 574
 575 struct elf_x86_link_hash_table
 576 {
 577   struct elf_link_hash_table elf;
 578
 579   /* Short-cuts to get to dynamic linker sections.  */
 580   asection *interp;
 581   asection *plt_eh_frame;
 582   asection *plt_second;
 583   asection *plt_second_eh_frame;
 584   asection *plt_got;
 585   asection *plt_got_eh_frame;
 586
 587   /* Parameters describing PLT generation, lazy or non-lazy.  */
 588   struct elf_x86_plt_layout plt;
 589
 590   /* Parameters describing lazy PLT generation.  */
 591   const struct elf_x86_lazy_plt_layout *lazy_plt;
 592
 593   /* Parameters describing non-lazy PLT generation.  */
 594   const struct elf_x86_non_lazy_plt_layout *non_lazy_plt;
 595
 596   union
 597   {
 598     bfd_signed_vma refcount;
 599     bfd_vma offset;
 600   } tls_ld_or_ldm_got;
 601
 602   /* The amount of space used by the jump slots in the GOT.  */
 603   bfd_vma sgotplt_jump_table_size;
 604
 605   /* _TLS_MODULE_BASE_ symbol.  */
 606   struct bfd_link_hash_entry *tls_module_base;
 607
 608   /* Used by local STT_GNU_IFUNC symbols.  */
 609   htab_t loc_hash_table;
 610   void * loc_hash_memory;
 611
 612   /* The index of the next R_X86_64_JUMP_SLOT entry in .rela.plt.  */
 613   bfd_vma next_jump_slot_index;
 614   /* The index of the next R_X86_64_IRELATIVE entry in .rela.plt.  */
 615   bfd_vma next_irelative_index;
 616
 617   /* The (unloaded but important) .rel.plt.unloaded section on VxWorks.
 618      This is used for i386 only.  */
 619   asection *srelplt2;
 620
 621   /* The index of the next unused R_386_TLS_DESC slot in .rel.plt.  This
 622      is only used for i386.  */
 623   bfd_vma next_tls_desc_index;
 624
 625   /* DT_RELR bitmap.  */
 626   struct elf_dt_relr_bitmap dt_relr_bitmap;
 627
 628   /* Relative relocation data.  */
 629   struct elf_x86_relative_reloc_data relative_reloc;
 630
 631   /* Unaligned relative relocation data.  */
 632   struct elf_x86_relative_reloc_data unaligned_relative_reloc;
 633
 634   /* Number of relative reloc generation pass.  */
 635   unsigned int generate_relative_reloc_pass;
 636
 637    /* Value used to fill the unused bytes of the first PLT entry.  This
 638       is only used for i386.  */
 639   bfd_byte plt0_pad_byte;
 640
 641   /* TRUE if GOT is referenced.  */
 642   unsigned int got_referenced : 1;
 643
 644   /* TRUE if PLT is PC-relative.  PLT in PDE and PC-relative PLT in PIE
 645      can be used as function address.
 646
 647      NB: i386 has non-PIC PLT and PIC PLT.  Only non-PIC PLT in PDE can
 648      be used as function address.  PIC PLT in PIE can't be used as
 649      function address.  */
 650   unsigned int pcrel_plt : 1;
 651
 652   bfd_vma (*r_info) (bfd_vma, bfd_vma);
 653   bfd_vma (*r_sym) (bfd_vma);
 654   bool (*is_reloc_section) (const char *);
 655   unsigned int sizeof_reloc;
 656   unsigned int got_entry_size;
 657   unsigned int pointer_r_type;
 658   unsigned int relative_r_type;
 659   int dynamic_interpreter_size;
 660   const char *dynamic_interpreter;
 661   const char *tls_get_addr;
 662   const char *relative_r_name;
 663   void (*elf_append_reloc) (bfd *, asection *, Elf_Internal_Rela *);
 664   void (*elf_write_addend) (bfd *, uint64_t, void *);
 665   void (*elf_write_addend_in_got) (bfd *, uint64_t, void *);
 666
 667   /* Options passed from the linker.  */
 668   struct elf_linker_x86_params *params;
 669 };
 670
 671 struct elf_x86_init_table
 672 {
 673   /* The lazy PLT layout.  */
 674   const struct elf_x86_lazy_plt_layout *lazy_plt;
 675
 676   /* The non-lazy PLT layout.  */
 677   const struct elf_x86_non_lazy_plt_layout *non_lazy_plt;
 678
 679   /* The lazy PLT layout for IBT.  */
 680   const struct elf_x86_lazy_plt_layout *lazy_ibt_plt;
 681
 682   /* The non-lazy PLT layout for IBT.  */
 683   const struct elf_x86_non_lazy_plt_layout *non_lazy_ibt_plt;
 684
 685   bfd_byte plt0_pad_byte;
 686
 687   bfd_vma (*r_info) (bfd_vma, bfd_vma);
 688   bfd_vma (*r_sym) (bfd_vma);
 689 };
 690
 691 struct elf_x86_obj_tdata
 692 {
 693   struct elf_obj_tdata root;
 694
 695   /* tls_type for each local got entry.  */
 696   char *local_got_tls_type;
 697
 698   /* GOTPLT entries for TLS descriptors.  */
 699   bfd_vma *local_tlsdesc_gotent;
 700
 701   /* R_*_RELATIVE relocation in GOT for this local symbol has been
 702      processed.  */
 703   char *relative_reloc_done;
 704 };
 705
 706 enum elf_x86_plt_type
 707 {
 708   plt_non_lazy = 0,
 709   plt_lazy = 1 << 0,
 710   plt_pic = 1 << 1,
 711   plt_second = 1 << 2,
 712   plt_unknown = -1
 713 };
 714
 715 struct elf_x86_plt
 716 {
 717   const char *name;
 718   asection *sec;
 719   bfd_byte *contents;
 720   enum elf_x86_plt_type type;
 721   unsigned int plt_got_offset;
 722   unsigned int plt_entry_size;
 723   unsigned int plt_got_insn_size;       /* Only used for x86-64.  */
 724   long count;
 725 };
 726
 727 /* Set if a relocation is converted from a GOTPCREL relocation.  */
 728 #define R_X86_64_converted_reloc_bit (1 << 7)
 729
 730 #define elf_x86_tdata(abfd) \
 731   ((struct elf_x86_obj_tdata *) (abfd)->tdata.any)
 732
 733 #define elf_x86_local_got_tls_type(abfd) \
 734   (elf_x86_tdata (abfd)->local_got_tls_type)
 735
 736 #define elf_x86_local_tlsdesc_gotent(abfd) \
 737   (elf_x86_tdata (abfd)->local_tlsdesc_gotent)
 738
 739 #define elf_x86_relative_reloc_done(abfd) \
 740   (elf_x86_tdata (abfd)->relative_reloc_done)
 741
 742 #define elf_x86_compute_jump_table_size(htab) \
 743   ((htab)->elf.srelplt->reloc_count * (htab)->got_entry_size)
 744
 745 #define is_x86_elf(bfd, htab)                           \
 746   (bfd_get_flavour (bfd) == bfd_target_elf_flavour      \
 747    && elf_tdata (bfd) != NULL                           \
 748    && elf_object_id (bfd) == (htab)->elf.hash_table_id)
 749
 750 /* Rename some of the generic section flags to better document how they
 751    are used here.  */
 752 #define check_relocs_failed     sec_flg0
 753 #define relative_reloc_packed   sec_flg1
 754
 755 extern bool _bfd_x86_elf_mkobject
 756   (bfd *);
 757
 758 extern void _bfd_x86_elf_set_tls_module_base
 759   (struct bfd_link_info *);
 760
 761 extern bfd_vma _bfd_x86_elf_dtpoff_base
 762   (struct bfd_link_info *);
 763
 764 extern bool _bfd_x86_elf_readonly_dynrelocs
 765   (struct elf_link_hash_entry *, void *);
 766
 767 extern struct elf_link_hash_entry * _bfd_elf_x86_get_local_sym_hash
 768   (struct elf_x86_link_hash_table *, bfd *, const Elf_Internal_Rela *,
 769    bool);
 770
 771 extern hashval_t _bfd_x86_elf_local_htab_hash
 772   (const void *);
 773
 774 extern int _bfd_x86_elf_local_htab_eq
 775   (const void *, const void *);
 776
 777 extern struct bfd_hash_entry * _bfd_x86_elf_link_hash_newfunc
 778   (struct bfd_hash_entry *, struct bfd_hash_table *, const char *);
 779
 780 extern struct bfd_link_hash_table * _bfd_x86_elf_link_hash_table_create
 781   (bfd *);
 782
 783 extern int _bfd_x86_elf_compare_relocs
 784   (const void *, const void *);
 785
 786 extern bool _bfd_x86_elf_link_check_relocs
 787   (bfd *, struct bfd_link_info *);
 788
 789 extern bool _bfd_x86_elf_check_relocs
 790   (bfd *, struct bfd_link_info *, asection *,
 791    const Elf_Internal_Rela *);
 792
 793 extern bool _bfd_x86_elf_link_relax_section
 794   (bfd *, asection *, struct bfd_link_info *, bool *);
 795
 796 extern bool _bfd_elf_x86_size_relative_relocs
 797   (struct bfd_link_info *, bool *);
 798
 799 extern bool _bfd_elf_x86_finish_relative_relocs
 800   (struct bfd_link_info *);
 801
 802 extern void _bfd_elf32_write_addend (bfd *, uint64_t, void *);
 803 extern void _bfd_elf64_write_addend (bfd *, uint64_t, void *);
 804
 805 extern bool _bfd_elf_x86_valid_reloc_p
 806   (asection *, struct bfd_link_info *, struct elf_x86_link_hash_table *,
 807    const Elf_Internal_Rela *, struct elf_link_hash_entry *,
 808    Elf_Internal_Sym *, Elf_Internal_Shdr *, bool *);
 809
 810 extern bool _bfd_x86_elf_size_dynamic_sections
 811   (bfd *, struct bfd_link_info *);
 812
 813 extern struct elf_x86_link_hash_table *_bfd_x86_elf_finish_dynamic_sections
 814   (bfd *, struct bfd_link_info *);
 815
 816 extern bool _bfd_x86_elf_always_size_sections
 817   (bfd *, struct bfd_link_info *);
 818
 819 extern void _bfd_x86_elf_merge_symbol_attribute
 820   (struct elf_link_hash_entry *, unsigned int, bool, bool);
 821
 822 extern void _bfd_x86_elf_copy_indirect_symbol
 823   (struct bfd_link_info *, struct elf_link_hash_entry *,
 824    struct elf_link_hash_entry *);
 825
 826 extern bool _bfd_x86_elf_fixup_symbol
 827   (struct bfd_link_info *, struct elf_link_hash_entry *);
 828
 829 extern bool _bfd_x86_elf_hash_symbol
 830   (struct elf_link_hash_entry *);
 831
 832 extern bool _bfd_x86_elf_adjust_dynamic_symbol
 833   (struct bfd_link_info *, struct elf_link_hash_entry *);
 834
 835 extern void _bfd_x86_elf_hide_symbol
 836   (struct bfd_link_info *, struct elf_link_hash_entry *, bool);
 837
 838 extern bool _bfd_x86_elf_link_symbol_references_local
 839   (struct bfd_link_info *, struct elf_link_hash_entry *);
 840
 841 extern asection * _bfd_x86_elf_gc_mark_hook
 842   (asection *, struct bfd_link_info *, Elf_Internal_Rela *,
 843    struct elf_link_hash_entry *, Elf_Internal_Sym *);
 844
 845 extern long _bfd_x86_elf_get_synthetic_symtab
 846   (bfd *, long, long, bfd_vma, struct elf_x86_plt [], asymbol **,
 847    asymbol **);
 848
 849 extern enum elf_property_kind _bfd_x86_elf_parse_gnu_properties
 850   (bfd *, unsigned int, bfd_byte *, unsigned int);
 851
 852 extern bool _bfd_x86_elf_merge_gnu_properties
 853   (struct bfd_link_info *, bfd *, bfd *, elf_property *, elf_property *);
 854
 855 extern void _bfd_x86_elf_link_fixup_gnu_properties
 856   (struct bfd_link_info *, elf_property_list **);
 857
 858 extern bfd * _bfd_x86_elf_link_setup_gnu_properties
 859   (struct bfd_link_info *, struct elf_x86_init_table *);
 860
 861 extern void _bfd_x86_elf_link_fixup_ifunc_symbol
 862   (struct bfd_link_info *, struct elf_x86_link_hash_table *,
 863    struct elf_link_hash_entry *, Elf_Internal_Sym *sym);
 864
 865 extern void _bfd_x86_elf_link_report_relative_reloc
 866   (struct bfd_link_info *, asection *, struct elf_link_hash_entry *,
 867    Elf_Internal_Sym *, const char *, const void *);
 868
 869 #define bfd_elf64_mkobject \
 870   _bfd_x86_elf_mkobject
 871 #define bfd_elf32_mkobject \
 872   _bfd_x86_elf_mkobject
 873 #define bfd_elf64_bfd_link_hash_table_create \
 874   _bfd_x86_elf_link_hash_table_create
 875 #define bfd_elf32_bfd_link_hash_table_create \
 876   _bfd_x86_elf_link_hash_table_create
 877 #define bfd_elf64_bfd_link_check_relocs \
 878   _bfd_x86_elf_link_check_relocs
 879 #define bfd_elf32_bfd_link_check_relocs \
 880   _bfd_x86_elf_link_check_relocs
 881 #define bfd_elf32_bfd_relax_section \
 882   _bfd_x86_elf_link_relax_section
 883 #define bfd_elf64_bfd_relax_section \
 884   _bfd_x86_elf_link_relax_section
 885
 886 #define elf_backend_check_relocs \
 887   _bfd_x86_elf_check_relocs
 888 #define elf_backend_size_dynamic_sections \
 889   _bfd_x86_elf_size_dynamic_sections
 890 #define elf_backend_merge_symbol_attribute \
 891   _bfd_x86_elf_merge_symbol_attribute
 892 #define elf_backend_copy_indirect_symbol \
 893   _bfd_x86_elf_copy_indirect_symbol
 894 #define elf_backend_fixup_symbol \
 895   _bfd_x86_elf_fixup_symbol
 896 #define elf_backend_hash_symbol \
 897   _bfd_x86_elf_hash_symbol
 898 #define elf_backend_adjust_dynamic_symbol \
 899   _bfd_x86_elf_adjust_dynamic_symbol
 900 #define elf_backend_gc_mark_hook \
 901   _bfd_x86_elf_gc_mark_hook
 902 #define elf_backend_omit_section_dynsym \
 903   _bfd_elf_omit_section_dynsym_all
 904 #define elf_backend_parse_gnu_properties \
 905   _bfd_x86_elf_parse_gnu_properties
 906 #define elf_backend_merge_gnu_properties \
 907   _bfd_x86_elf_merge_gnu_properties
 908 #define elf_backend_fixup_gnu_properties \
 909   _bfd_x86_elf_link_fixup_gnu_properties
 910 #define elf_backend_size_relative_relocs \
 911   _bfd_elf_x86_size_relative_relocs
 912 #define elf_backend_finish_relative_relocs \
 913   _bfd_elf_x86_finish_relative_relocs
 914
 915 #define ELF_P_ALIGN ELF_MINPAGESIZE
 916
 917 /* Allocate x86 GOT info for local symbols.  */
 918
 919 static inline bool
 920 elf_x86_allocate_local_got_info (bfd *abfd, bfd_size_type count)
 921 {
 922   bfd_signed_vma *local_got_refcounts = elf_local_got_refcounts (abfd);
 923   if (local_got_refcounts == NULL)
 924     {
 925       bfd_size_type size = count * (sizeof (bfd_signed_vma)
 926                                     + sizeof (bfd_vma)
 927                                     + 2 * sizeof(char));
 928       local_got_refcounts = (bfd_signed_vma *) bfd_zalloc (abfd, size);
 929       if (local_got_refcounts == NULL)
 930         return false;
 931       elf_local_got_refcounts (abfd) = local_got_refcounts;
 932       elf_x86_local_tlsdesc_gotent (abfd) =
 933         (bfd_vma *) (local_got_refcounts + count);
 934       elf_x86_local_got_tls_type (abfd) =
 935         (char *) (local_got_refcounts + 2 * count);
 936       elf_x86_relative_reloc_done (abfd) =
 937         ((char *) (local_got_refcounts + 2 * count)) + count;
 938     }
 939   return true;
 940 }