gold/x86_64.cc

   1 // x86_64.cc -- x86_64 target support for gold.
   2
   3 // Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
   4 // Written by Ian Lance Taylor <iant@google.com>.
   5
   6 // This file is part of gold.
   7
   8 // This program is free software; you can redistribute it and/or modify
   9 // it under the terms of the GNU General Public License as published by
  10 // the Free Software Foundation; either version 3 of the License, or
  11 // (at your option) any later version.
  12
  13 // This program is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17
  18 // You should have received a copy of the GNU General Public License
  19 // along with this program; if not, write to the Free Software
  20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  21 // MA 02110-1301, USA.
  22
  23 #include "gold.h"
  24
  25 #include <cstring>
  26
  27 #include "elfcpp.h"
  28 #include "parameters.h"
  29 #include "reloc.h"
  30 #include "x86_64.h"
  31 #include "object.h"
  32 #include "symtab.h"
  33 #include "layout.h"
  34 #include "output.h"
  35 #include "copy-relocs.h"
  36 #include "target.h"
  37 #include "target-reloc.h"
  38 #include "target-select.h"
  39 #include "tls.h"
  40
  41 namespace
  42 {
  43
  44 using namespace gold;
  45
  46 class Output_data_plt_x86_64;
  47
  48 // The x86_64 target class.
  49 // See the ABI at
  50 //   http://www.x86-64.org/documentation/abi.pdf
  51 // TLS info comes from
  52 //   http://people.redhat.com/drepper/tls.pdf
  53 //   http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
  54
  55 class Target_x86_64 : public Sized_target<64, false>
  56 {
  57  public:
  58   // In the x86_64 ABI (p 68), it says "The AMD64 ABI architectures
  59   // uses only Elf64_Rela relocation entries with explicit addends."
  60   typedef Output_data_reloc<elfcpp::SHT_RELA, true, 64, false> Reloc_section;
  61
  62   Target_x86_64()
  63     : Sized_target<64, false>(&x86_64_info),
  64       got_(NULL), plt_(NULL), got_plt_(NULL), rela_dyn_(NULL),
  65       copy_relocs_(elfcpp::R_X86_64_COPY), dynbss_(NULL),
  66       got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
  67   { }
  68
  69   // Scan the relocations to look for symbol adjustments.
  70   void
  71   scan_relocs(const General_options& options,
  72               Symbol_table* symtab,
  73               Layout* layout,
  74               Sized_relobj<64, false>* object,
  75               unsigned int data_shndx,
  76               unsigned int sh_type,
  77               const unsigned char* prelocs,
  78               size_t reloc_count,
  79               Output_section* output_section,
  80               bool needs_special_offset_handling,
  81               size_t local_symbol_count,
  82               const unsigned char* plocal_symbols);
  83
  84   // Finalize the sections.
  85   void
  86   do_finalize_sections(Layout*);
  87
  88   // Return the value to use for a dynamic which requires special
  89   // treatment.
  90   uint64_t
  91   do_dynsym_value(const Symbol*) const;
  92
  93   // Relocate a section.
  94   void
  95   relocate_section(const Relocate_info<64, false>*,
  96                    unsigned int sh_type,
  97                    const unsigned char* prelocs,
  98                    size_t reloc_count,
  99                    Output_section* output_section,
 100                    bool needs_special_offset_handling,
 101                    unsigned char* view,
 102                    elfcpp::Elf_types<64>::Elf_Addr view_address,
 103                    section_size_type view_size);
 104
 105   // Scan the relocs during a relocatable link.
 106   void
 107   scan_relocatable_relocs(const General_options& options,
 108                           Symbol_table* symtab,
 109                           Layout* layout,
 110                           Sized_relobj<64, false>* object,
 111                           unsigned int data_shndx,
 112                           unsigned int sh_type,
 113                           const unsigned char* prelocs,
 114                           size_t reloc_count,
 115                           Output_section* output_section,
 116                           bool needs_special_offset_handling,
 117                           size_t local_symbol_count,
 118                           const unsigned char* plocal_symbols,
 119                           Relocatable_relocs*);
 120
 121   // Relocate a section during a relocatable link.
 122   void
 123   relocate_for_relocatable(const Relocate_info<64, false>*,
 124                            unsigned int sh_type,
 125                            const unsigned char* prelocs,
 126                            size_t reloc_count,
 127                            Output_section* output_section,
 128                            off_t offset_in_output_section,
 129                            const Relocatable_relocs*,
 130                            unsigned char* view,
 131                            elfcpp::Elf_types<64>::Elf_Addr view_address,
 132                            section_size_type view_size,
 133                            unsigned char* reloc_view,
 134                            section_size_type reloc_view_size);
 135
 136   // Return a string used to fill a code section with nops.
 137   std::string
 138   do_code_fill(section_size_type length) const;
 139
 140   // Return whether SYM is defined by the ABI.
 141   bool
 142   do_is_defined_by_abi(Symbol* sym) const
 143   { return strcmp(sym->name(), "__tls_get_addr") == 0; }
 144
 145   // Return the size of the GOT section.
 146   section_size_type
 147   got_size()
 148   {
 149     gold_assert(this->got_ != NULL);
 150     return this->got_->data_size();
 151   }
 152
 153  private:
 154   // The class which scans relocations.
 155   class Scan
 156   {
 157   public:
 158     Scan()
 159       : issued_non_pic_error_(false)
 160     { }
 161
 162     inline void
 163     local(const General_options& options, Symbol_table* symtab,
 164           Layout* layout, Target_x86_64* target,
 165           Sized_relobj<64, false>* object,
 166           unsigned int data_shndx,
 167           Output_section* output_section,
 168           const elfcpp::Rela<64, false>& reloc, unsigned int r_type,
 169           const elfcpp::Sym<64, false>& lsym);
 170
 171     inline void
 172     global(const General_options& options, Symbol_table* symtab,
 173            Layout* layout, Target_x86_64* target,
 174            Sized_relobj<64, false>* object,
 175            unsigned int data_shndx,
 176            Output_section* output_section,
 177            const elfcpp::Rela<64, false>& reloc, unsigned int r_type,
 178            Symbol* gsym);
 179
 180   private:
 181     static void
 182     unsupported_reloc_local(Sized_relobj<64, false>*, unsigned int r_type);
 183
 184     static void
 185     unsupported_reloc_global(Sized_relobj<64, false>*, unsigned int r_type,
 186                              Symbol*);
 187
 188     void
 189     check_non_pic(Relobj*, unsigned int r_type);
 190
 191     // Whether we have issued an error about a non-PIC compilation.
 192     bool issued_non_pic_error_;
 193   };
 194
 195   // The class which implements relocation.
 196   class Relocate
 197   {
 198    public:
 199     Relocate()
 200       : skip_call_tls_get_addr_(false), saw_tls_block_reloc_(false)
 201     { }
 202
 203     ~Relocate()
 204     {
 205       if (this->skip_call_tls_get_addr_)
 206         {
 207           // FIXME: This needs to specify the location somehow.
 208           gold_error(_("missing expected TLS relocation"));
 209         }
 210     }
 211
 212     // Do a relocation.  Return false if the caller should not issue
 213     // any warnings about this relocation.
 214     inline bool
 215     relocate(const Relocate_info<64, false>*, Target_x86_64*, size_t relnum,
 216              const elfcpp::Rela<64, false>&,
 217              unsigned int r_type, const Sized_symbol<64>*,
 218              const Symbol_value<64>*,
 219              unsigned char*, elfcpp::Elf_types<64>::Elf_Addr,
 220              section_size_type);
 221
 222    private:
 223     // Do a TLS relocation.
 224     inline void
 225     relocate_tls(const Relocate_info<64, false>*, Target_x86_64*,
 226                  size_t relnum, const elfcpp::Rela<64, false>&,
 227                  unsigned int r_type, const Sized_symbol<64>*,
 228                  const Symbol_value<64>*,
 229                  unsigned char*, elfcpp::Elf_types<64>::Elf_Addr,
 230                  section_size_type);
 231
 232     // Do a TLS General-Dynamic to Initial-Exec transition.
 233     inline void
 234     tls_gd_to_ie(const Relocate_info<64, false>*, size_t relnum,
 235                  Output_segment* tls_segment,
 236                  const elfcpp::Rela<64, false>&, unsigned int r_type,
 237                  elfcpp::Elf_types<64>::Elf_Addr value,
 238                  unsigned char* view,
 239                  elfcpp::Elf_types<64>::Elf_Addr,
 240                  section_size_type view_size);
 241
 242     // Do a TLS General-Dynamic to Local-Exec transition.
 243     inline void
 244     tls_gd_to_le(const Relocate_info<64, false>*, size_t relnum,
 245                  Output_segment* tls_segment,
 246                  const elfcpp::Rela<64, false>&, unsigned int r_type,
 247                  elfcpp::Elf_types<64>::Elf_Addr value,
 248                  unsigned char* view,
 249                  section_size_type view_size);
 250
 251     // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
 252     inline void
 253     tls_desc_gd_to_ie(const Relocate_info<64, false>*, size_t relnum,
 254                       Output_segment* tls_segment,
 255                       const elfcpp::Rela<64, false>&, unsigned int r_type,
 256                       elfcpp::Elf_types<64>::Elf_Addr value,
 257                       unsigned char* view,
 258                       elfcpp::Elf_types<64>::Elf_Addr,
 259                       section_size_type view_size);
 260
 261     // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
 262     inline void
 263     tls_desc_gd_to_le(const Relocate_info<64, false>*, size_t relnum,
 264                       Output_segment* tls_segment,
 265                       const elfcpp::Rela<64, false>&, unsigned int r_type,
 266                       elfcpp::Elf_types<64>::Elf_Addr value,
 267                       unsigned char* view,
 268                       section_size_type view_size);
 269
 270     // Do a TLS Local-Dynamic to Local-Exec transition.
 271     inline void
 272     tls_ld_to_le(const Relocate_info<64, false>*, size_t relnum,
 273                  Output_segment* tls_segment,
 274                  const elfcpp::Rela<64, false>&, unsigned int r_type,
 275                  elfcpp::Elf_types<64>::Elf_Addr value,
 276                  unsigned char* view,
 277                  section_size_type view_size);
 278
 279     // Do a TLS Initial-Exec to Local-Exec transition.
 280     static inline void
 281     tls_ie_to_le(const Relocate_info<64, false>*, size_t relnum,
 282                  Output_segment* tls_segment,
 283                  const elfcpp::Rela<64, false>&, unsigned int r_type,
 284                  elfcpp::Elf_types<64>::Elf_Addr value,
 285                  unsigned char* view,
 286                  section_size_type view_size);
 287
 288     // This is set if we should skip the next reloc, which should be a
 289     // PLT32 reloc against ___tls_get_addr.
 290     bool skip_call_tls_get_addr_;
 291
 292     // This is set if we see a relocation which could load the address
 293     // of the TLS block.  Whether we see such a relocation determines
 294     // how we handle the R_X86_64_DTPOFF32 relocation, which is used
 295     // in debugging sections.
 296     bool saw_tls_block_reloc_;
 297   };
 298
 299   // A class which returns the size required for a relocation type,
 300   // used while scanning relocs during a relocatable link.
 301   class Relocatable_size_for_reloc
 302   {
 303    public:
 304     unsigned int
 305     get_size_for_reloc(unsigned int, Relobj*);
 306   };
 307
 308   // Adjust TLS relocation type based on the options and whether this
 309   // is a local symbol.
 310   static tls::Tls_optimization
 311   optimize_tls_reloc(bool is_final, int r_type);
 312
 313   // Get the GOT section, creating it if necessary.
 314   Output_data_got<64, false>*
 315   got_section(Symbol_table*, Layout*);
 316
 317   // Get the GOT PLT section.
 318   Output_data_space*
 319   got_plt_section() const
 320   {
 321     gold_assert(this->got_plt_ != NULL);
 322     return this->got_plt_;
 323   }
 324
 325   // Create the PLT section.
 326   void
 327   make_plt_section(Symbol_table* symtab, Layout* layout);
 328
 329   // Create a PLT entry for a global symbol.
 330   void
 331   make_plt_entry(Symbol_table*, Layout*, Symbol*);
 332
 333   // Define the _TLS_MODULE_BASE_ symbol at the end of the TLS segment.
 334   void
 335   define_tls_base_symbol(Symbol_table*, Layout*);
 336
 337   // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
 338   void
 339   reserve_tlsdesc_entries(Symbol_table* symtab, Layout* layout);
 340
 341   // Create a GOT entry for the TLS module index.
 342   unsigned int
 343   got_mod_index_entry(Symbol_table* symtab, Layout* layout,
 344                       Sized_relobj<64, false>* object);
 345
 346   // Get the PLT section.
 347   Output_data_plt_x86_64*
 348   plt_section() const
 349   {
 350     gold_assert(this->plt_ != NULL);
 351     return this->plt_;
 352   }
 353
 354   // Get the dynamic reloc section, creating it if necessary.
 355   Reloc_section*
 356   rela_dyn_section(Layout*);
 357
 358   // Return true if the symbol may need a COPY relocation.
 359   // References from an executable object to non-function symbols
 360   // defined in a dynamic object may need a COPY relocation.
 361   bool
 362   may_need_copy_reloc(Symbol* gsym)
 363   {
 364     return (!parameters->options().shared()
 365             && gsym->is_from_dynobj()
 366             && gsym->type() != elfcpp::STT_FUNC);
 367   }
 368
 369   // Add a potential copy relocation.
 370   void
 371   copy_reloc(Symbol_table* symtab, Layout* layout, Relobj* object,
 372              unsigned int shndx, Output_section* output_section,
 373              Symbol* sym, const elfcpp::Rela<64, false>& reloc)
 374   {
 375     this->copy_relocs_.copy_reloc(symtab, layout,
 376                                   symtab->get_sized_symbol<64>(sym),
 377                                   object, shndx, output_section,
 378                                   reloc, this->rela_dyn_section(layout));
 379   }
 380
 381   // Information about this specific target which we pass to the
 382   // general Target structure.
 383   static const Target::Target_info x86_64_info;
 384
 385   enum Got_type
 386   {
 387     GOT_TYPE_STANDARD = 0,      // GOT entry for a regular symbol
 388     GOT_TYPE_TLS_OFFSET = 1,    // GOT entry for TLS offset
 389     GOT_TYPE_TLS_PAIR = 2,      // GOT entry for TLS module/offset pair
 390     GOT_TYPE_TLS_DESC = 3       // GOT entry for TLS_DESC pair
 391   };
 392
 393   // The GOT section.
 394   Output_data_got<64, false>* got_;
 395   // The PLT section.
 396   Output_data_plt_x86_64* plt_;
 397   // The GOT PLT section.
 398   Output_data_space* got_plt_;
 399   // The dynamic reloc section.
 400   Reloc_section* rela_dyn_;
 401   // Relocs saved to avoid a COPY reloc.
 402   Copy_relocs<elfcpp::SHT_RELA, 64, false> copy_relocs_;
 403   // Space for variables copied with a COPY reloc.
 404   Output_data_space* dynbss_;
 405   // Offset of the GOT entry for the TLS module index.
 406   unsigned int got_mod_index_offset_;
 407   // True if the _TLS_MODULE_BASE_ symbol has been defined.
 408   bool tls_base_symbol_defined_;
 409 };
 410
 411 const Target::Target_info Target_x86_64::x86_64_info =
 412 {
 413   64,                   // size
 414   false,                // is_big_endian
 415   elfcpp::EM_X86_64,    // machine_code
 416   false,                // has_make_symbol
 417   false,                // has_resolve
 418   true,                 // has_code_fill
 419   true,                 // is_default_stack_executable
 420   '\0',                 // wrap_char
 421   "/lib/ld64.so.1",     // program interpreter
 422   0x400000,             // default_text_segment_address
 423   0x1000,               // abi_pagesize (overridable by -z max-page-size)
 424   0x1000                // common_pagesize (overridable by -z common-page-size)
 425 };
 426
 427 // Get the GOT section, creating it if necessary.
 428
 429 Output_data_got<64, false>*
 430 Target_x86_64::got_section(Symbol_table* symtab, Layout* layout)
 431 {
 432   if (this->got_ == NULL)
 433     {
 434       gold_assert(symtab != NULL && layout != NULL);
 435
 436       this->got_ = new Output_data_got<64, false>();
 437
 438       Output_section* os;
 439       os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
 440                                            (elfcpp::SHF_ALLOC
 441                                             | elfcpp::SHF_WRITE),
 442                                            this->got_);
 443       os->set_is_relro();
 444
 445       // The old GNU linker creates a .got.plt section.  We just
 446       // create another set of data in the .got section.  Note that we
 447       // always create a PLT if we create a GOT, although the PLT
 448       // might be empty.
 449       this->got_plt_ = new Output_data_space(8);
 450       os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
 451                                            (elfcpp::SHF_ALLOC
 452                                             | elfcpp::SHF_WRITE),
 453                                            this->got_plt_);
 454       os->set_is_relro();
 455
 456       // The first three entries are reserved.
 457       this->got_plt_->set_current_data_size(3 * 8);
 458
 459       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
 460       symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
 461                                     this->got_plt_,
 462                                     0, 0, elfcpp::STT_OBJECT,
 463                                     elfcpp::STB_LOCAL,
 464                                     elfcpp::STV_HIDDEN, 0,
 465                                     false, false);
 466     }
 467
 468   return this->got_;
 469 }
 470
 471 // Get the dynamic reloc section, creating it if necessary.
 472
 473 Target_x86_64::Reloc_section*
 474 Target_x86_64::rela_dyn_section(Layout* layout)
 475 {
 476   if (this->rela_dyn_ == NULL)
 477     {
 478       gold_assert(layout != NULL);
 479       this->rela_dyn_ = new Reloc_section(parameters->options().combreloc());
 480       layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
 481                                       elfcpp::SHF_ALLOC, this->rela_dyn_);
 482     }
 483   return this->rela_dyn_;
 484 }
 485
 486 // A class to handle the PLT data.
 487
 488 class Output_data_plt_x86_64 : public Output_section_data
 489 {
 490  public:
 491   typedef Output_data_reloc<elfcpp::SHT_RELA, true, 64, false> Reloc_section;
 492
 493   Output_data_plt_x86_64(Layout*, Output_data_got<64, false>*,
 494                          Output_data_space*);
 495
 496   // Add an entry to the PLT.
 497   void
 498   add_entry(Symbol* gsym);
 499
 500   // Add the reserved TLSDESC_PLT entry to the PLT.
 501   void
 502   reserve_tlsdesc_entry(unsigned int got_offset)
 503   { this->tlsdesc_got_offset_ = got_offset; }
 504
 505   // Return true if a TLSDESC_PLT entry has been reserved.
 506   bool
 507   has_tlsdesc_entry() const
 508   { return this->tlsdesc_got_offset_ != -1U; }
 509
 510   // Return the GOT offset for the reserved TLSDESC_PLT entry.
 511   unsigned int
 512   get_tlsdesc_got_offset() const
 513   { return this->tlsdesc_got_offset_; }
 514
 515   // Return the offset of the reserved TLSDESC_PLT entry.
 516   unsigned int
 517   get_tlsdesc_plt_offset() const
 518   { return (this->count_ + 1) * plt_entry_size; }
 519
 520   // Return the .rel.plt section data.
 521   const Reloc_section*
 522   rel_plt() const
 523   { return this->rel_; }
 524
 525  protected:
 526   void
 527   do_adjust_output_section(Output_section* os);
 528
 529  private:
 530   // The size of an entry in the PLT.
 531   static const int plt_entry_size = 16;
 532
 533   // The first entry in the PLT.
 534   // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
 535   // procedure linkage table for both programs and shared objects."
 536   static unsigned char first_plt_entry[plt_entry_size];
 537
 538   // Other entries in the PLT for an executable.
 539   static unsigned char plt_entry[plt_entry_size];
 540
 541   // The reserved TLSDESC entry in the PLT for an executable.
 542   static unsigned char tlsdesc_plt_entry[plt_entry_size];
 543
 544   // Set the final size.
 545   void
 546   set_final_data_size();
 547
 548   // Write out the PLT data.
 549   void
 550   do_write(Output_file*);
 551
 552   // The reloc section.
 553   Reloc_section* rel_;
 554   // The .got section.
 555   Output_data_got<64, false>* got_;
 556   // The .got.plt section.
 557   Output_data_space* got_plt_;
 558   // The number of PLT entries.
 559   unsigned int count_;
 560   // Offset of the reserved TLSDESC_GOT entry when needed.
 561   unsigned int tlsdesc_got_offset_;
 562 };
 563
 564 // Create the PLT section.  The ordinary .got section is an argument,
 565 // since we need to refer to the start.  We also create our own .got
 566 // section just for PLT entries.
 567
 568 Output_data_plt_x86_64::Output_data_plt_x86_64(Layout* layout,
 569                                                Output_data_got<64, false>* got,
 570                                                Output_data_space* got_plt)
 571   : Output_section_data(8), got_(got), got_plt_(got_plt), count_(0),
 572     tlsdesc_got_offset_(-1U)
 573 {
 574   this->rel_ = new Reloc_section(false);
 575   layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
 576                                   elfcpp::SHF_ALLOC, this->rel_);
 577 }
 578
 579 void
 580 Output_data_plt_x86_64::do_adjust_output_section(Output_section* os)
 581 {
 582   // UnixWare sets the entsize of .plt to 4, and so does the old GNU
 583   // linker, and so do we.
 584   os->set_entsize(4);
 585 }
 586
 587 // Add an entry to the PLT.
 588
 589 void
 590 Output_data_plt_x86_64::add_entry(Symbol* gsym)
 591 {
 592   gold_assert(!gsym->has_plt_offset());
 593
 594   // Note that when setting the PLT offset we skip the initial
 595   // reserved PLT entry.
 596   gsym->set_plt_offset((this->count_ + 1) * plt_entry_size);
 597
 598   ++this->count_;
 599
 600   section_offset_type got_offset = this->got_plt_->current_data_size();
 601
 602   // Every PLT entry needs a GOT entry which points back to the PLT
 603   // entry (this will be changed by the dynamic linker, normally
 604   // lazily when the function is called).
 605   this->got_plt_->set_current_data_size(got_offset + 8);
 606
 607   // Every PLT entry needs a reloc.
 608   gsym->set_needs_dynsym_entry();
 609   this->rel_->add_global(gsym, elfcpp::R_X86_64_JUMP_SLOT, this->got_plt_,
 610                          got_offset, 0);
 611
 612   // Note that we don't need to save the symbol.  The contents of the
 613   // PLT are independent of which symbols are used.  The symbols only
 614   // appear in the relocations.
 615 }
 616
 617 // Set the final size.
 618 void
 619 Output_data_plt_x86_64::set_final_data_size()
 620 {
 621   unsigned int count = this->count_;
 622   if (this->has_tlsdesc_entry())
 623     ++count;
 624   this->set_data_size((count + 1) * plt_entry_size);
 625 }
 626
 627 // The first entry in the PLT for an executable.
 628
 629 unsigned char Output_data_plt_x86_64::first_plt_entry[plt_entry_size] =
 630 {
 631   // From AMD64 ABI Draft 0.98, page 76
 632   0xff, 0x35,   // pushq contents of memory address
 633   0, 0, 0, 0,   // replaced with address of .got + 8
 634   0xff, 0x25,   // jmp indirect
 635   0, 0, 0, 0,   // replaced with address of .got + 16
 636   0x90, 0x90, 0x90, 0x90   // noop (x4)
 637 };
 638
 639 // Subsequent entries in the PLT for an executable.
 640
 641 unsigned char Output_data_plt_x86_64::plt_entry[plt_entry_size] =
 642 {
 643   // From AMD64 ABI Draft 0.98, page 76
 644   0xff, 0x25,   // jmpq indirect
 645   0, 0, 0, 0,   // replaced with address of symbol in .got
 646   0x68,         // pushq immediate
 647   0, 0, 0, 0,   // replaced with offset into relocation table
 648   0xe9,         // jmpq relative
 649   0, 0, 0, 0    // replaced with offset to start of .plt
 650 };
 651
 652 // The reserved TLSDESC entry in the PLT for an executable.
 653
 654 unsigned char Output_data_plt_x86_64::tlsdesc_plt_entry[plt_entry_size] =
 655 {
 656   // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
 657   // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
 658   0xff, 0x35,   // pushq x(%rip)
 659   0, 0, 0, 0,   // replaced with address of linkmap GOT entry (at PLTGOT + 8)
 660   0xff, 0x25,   // jmpq *y(%rip)
 661   0, 0, 0, 0,   // replaced with offset of reserved TLSDESC_GOT entry
 662   0x0f, 0x1f,   // nop
 663   0x40, 0
 664 };
 665
 666 // Write out the PLT.  This uses the hand-coded instructions above,
 667 // and adjusts them as needed.  This is specified by the AMD64 ABI.
 668
 669 void
 670 Output_data_plt_x86_64::do_write(Output_file* of)
 671 {
 672   const off_t offset = this->offset();
 673   const section_size_type oview_size =
 674     convert_to_section_size_type(this->data_size());
 675   unsigned char* const oview = of->get_output_view(offset, oview_size);
 676
 677   const off_t got_file_offset = this->got_plt_->offset();
 678   const section_size_type got_size =
 679     convert_to_section_size_type(this->got_plt_->data_size());
 680   unsigned char* const got_view = of->get_output_view(got_file_offset,
 681                                                       got_size);
 682
 683   unsigned char* pov = oview;
 684
 685   // The base address of the .plt section.
 686   elfcpp::Elf_types<64>::Elf_Addr plt_address = this->address();
 687   // The base address of the .got section.
 688   elfcpp::Elf_types<64>::Elf_Addr got_base = this->got_->address();
 689   // The base address of the PLT portion of the .got section,
 690   // which is where the GOT pointer will point, and where the
 691   // three reserved GOT entries are located.
 692   elfcpp::Elf_types<64>::Elf_Addr got_address = this->got_plt_->address();
 693
 694   memcpy(pov, first_plt_entry, plt_entry_size);
 695   // We do a jmp relative to the PC at the end of this instruction.
 696   elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
 697                                               (got_address + 8
 698                                                - (plt_address + 6)));
 699   elfcpp::Swap<32, false>::writeval(pov + 8,
 700                                     (got_address + 16
 701                                      - (plt_address + 12)));
 702   pov += plt_entry_size;
 703
 704   unsigned char* got_pov = got_view;
 705
 706   memset(got_pov, 0, 24);
 707   got_pov += 24;
 708
 709   unsigned int plt_offset = plt_entry_size;
 710   unsigned int got_offset = 24;
 711   const unsigned int count = this->count_;
 712   for (unsigned int plt_index = 0;
 713        plt_index < count;
 714        ++plt_index,
 715          pov += plt_entry_size,
 716          got_pov += 8,
 717          plt_offset += plt_entry_size,
 718          got_offset += 8)
 719     {
 720       // Set and adjust the PLT entry itself.
 721       memcpy(pov, plt_entry, plt_entry_size);
 722       elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
 723                                                   (got_address + got_offset
 724                                                    - (plt_address + plt_offset
 725                                                       + 6)));
 726
 727       elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_index);
 728       elfcpp::Swap<32, false>::writeval(pov + 12,
 729                                         - (plt_offset + plt_entry_size));
 730
 731       // Set the entry in the GOT.
 732       elfcpp::Swap<64, false>::writeval(got_pov, plt_address + plt_offset + 6);
 733     }
 734
 735   if (this->has_tlsdesc_entry())
 736     {
 737       // Set and adjust the reserved TLSDESC PLT entry.
 738       unsigned int tlsdesc_got_offset = this->get_tlsdesc_got_offset();
 739       memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
 740       elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
 741                                                   (got_address + 8
 742                                                    - (plt_address + plt_offset
 743                                                       + 6)));
 744       elfcpp::Swap_unaligned<32, false>::writeval(pov + 8,
 745                                                   (got_base
 746                                                    + tlsdesc_got_offset
 747                                                    - (plt_address + plt_offset
 748                                                       + 12)));
 749       pov += plt_entry_size;
 750     }
 751
 752   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
 753   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
 754
 755   of->write_output_view(offset, oview_size, oview);
 756   of->write_output_view(got_file_offset, got_size, got_view);
 757 }
 758
 759 // Create the PLT section.
 760
 761 void
 762 Target_x86_64::make_plt_section(Symbol_table* symtab, Layout* layout)
 763 {
 764   if (this->plt_ == NULL)
 765     {
 766       // Create the GOT sections first.
 767       this->got_section(symtab, layout);
 768
 769       this->plt_ = new Output_data_plt_x86_64(layout, this->got_,
 770                                               this->got_plt_);
 771       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
 772                                       (elfcpp::SHF_ALLOC
 773                                        | elfcpp::SHF_EXECINSTR),
 774                                       this->plt_);
 775     }
 776 }
 777
 778 // Create a PLT entry for a global symbol.
 779
 780 void
 781 Target_x86_64::make_plt_entry(Symbol_table* symtab, Layout* layout,
 782                               Symbol* gsym)
 783 {
 784   if (gsym->has_plt_offset())
 785     return;
 786
 787   if (this->plt_ == NULL)
 788     this->make_plt_section(symtab, layout);
 789
 790   this->plt_->add_entry(gsym);
 791 }
 792
 793 // Define the _TLS_MODULE_BASE_ symbol at the end of the TLS segment.
 794
 795 void
 796 Target_x86_64::define_tls_base_symbol(Symbol_table* symtab, Layout* layout)
 797 {
 798   if (this->tls_base_symbol_defined_)
 799     return;
 800
 801   Output_segment* tls_segment = layout->tls_segment();
 802   if (tls_segment != NULL)
 803     {
 804       symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
 805                                        tls_segment, 0, 0,
 806                                        elfcpp::STT_TLS,
 807                                        elfcpp::STB_LOCAL,
 808                                        elfcpp::STV_HIDDEN, 0,
 809                                        Symbol::SEGMENT_END, true);
 810     }
 811   this->tls_base_symbol_defined_ = true;
 812 }
 813
 814 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
 815
 816 void
 817 Target_x86_64::reserve_tlsdesc_entries(Symbol_table* symtab,
 818                                              Layout* layout)
 819 {
 820   if (this->plt_ == NULL)
 821     this->make_plt_section(symtab, layout);
 822
 823   if (!this->plt_->has_tlsdesc_entry())
 824     {
 825       // Allocate the TLSDESC_GOT entry.
 826       Output_data_got<64, false>* got = this->got_section(symtab, layout);
 827       unsigned int got_offset = got->add_constant(0);
 828
 829       // Allocate the TLSDESC_PLT entry.
 830       this->plt_->reserve_tlsdesc_entry(got_offset);
 831     }
 832 }
 833
 834 // Create a GOT entry for the TLS module index.
 835
 836 unsigned int
 837 Target_x86_64::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
 838                                    Sized_relobj<64, false>* object)
 839 {
 840   if (this->got_mod_index_offset_ == -1U)
 841     {
 842       gold_assert(symtab != NULL && layout != NULL && object != NULL);
 843       Reloc_section* rela_dyn = this->rela_dyn_section(layout);
 844       Output_data_got<64, false>* got = this->got_section(symtab, layout);
 845       unsigned int got_offset = got->add_constant(0);
 846       rela_dyn->add_local(object, 0, elfcpp::R_X86_64_DTPMOD64, got,
 847                           got_offset, 0);
 848       got->add_constant(0);
 849       this->got_mod_index_offset_ = got_offset;
 850     }
 851   return this->got_mod_index_offset_;
 852 }
 853
 854 // Optimize the TLS relocation type based on what we know about the
 855 // symbol.  IS_FINAL is true if the final address of this symbol is
 856 // known at link time.
 857
 858 tls::Tls_optimization
 859 Target_x86_64::optimize_tls_reloc(bool is_final, int r_type)
 860 {
 861   // If we are generating a shared library, then we can't do anything
 862   // in the linker.
 863   if (parameters->options().shared())
 864     return tls::TLSOPT_NONE;
 865
 866   switch (r_type)
 867     {
 868     case elfcpp::R_X86_64_TLSGD:
 869     case elfcpp::R_X86_64_GOTPC32_TLSDESC:
 870     case elfcpp::R_X86_64_TLSDESC_CALL:
 871       // These are General-Dynamic which permits fully general TLS
 872       // access.  Since we know that we are generating an executable,
 873       // we can convert this to Initial-Exec.  If we also know that
 874       // this is a local symbol, we can further switch to Local-Exec.
 875       if (is_final)
 876         return tls::TLSOPT_TO_LE;
 877       return tls::TLSOPT_TO_IE;
 878
 879     case elfcpp::R_X86_64_TLSLD:
 880       // This is Local-Dynamic, which refers to a local symbol in the
 881       // dynamic TLS block.  Since we know that we generating an
 882       // executable, we can switch to Local-Exec.
 883       return tls::TLSOPT_TO_LE;
 884
 885     case elfcpp::R_X86_64_DTPOFF32:
 886     case elfcpp::R_X86_64_DTPOFF64:
 887       // Another Local-Dynamic reloc.
 888       return tls::TLSOPT_TO_LE;
 889
 890     case elfcpp::R_X86_64_GOTTPOFF:
 891       // These are Initial-Exec relocs which get the thread offset
 892       // from the GOT.  If we know that we are linking against the
 893       // local symbol, we can switch to Local-Exec, which links the
 894       // thread offset into the instruction.
 895       if (is_final)
 896         return tls::TLSOPT_TO_LE;
 897       return tls::TLSOPT_NONE;
 898
 899     case elfcpp::R_X86_64_TPOFF32:
 900       // When we already have Local-Exec, there is nothing further we
 901       // can do.
 902       return tls::TLSOPT_NONE;
 903
 904     default:
 905       gold_unreachable();
 906     }
 907 }
 908
 909 // Report an unsupported relocation against a local symbol.
 910
 911 void
 912 Target_x86_64::Scan::unsupported_reloc_local(Sized_relobj<64, false>* object,
 913                                              unsigned int r_type)
 914 {
 915   gold_error(_("%s: unsupported reloc %u against local symbol"),
 916              object->name().c_str(), r_type);
 917 }
 918
 919 // We are about to emit a dynamic relocation of type R_TYPE.  If the
 920 // dynamic linker does not support it, issue an error.  The GNU linker
 921 // only issues a non-PIC error for an allocated read-only section.
 922 // Here we know the section is allocated, but we don't know that it is
 923 // read-only.  But we check for all the relocation types which the
 924 // glibc dynamic linker supports, so it seems appropriate to issue an
 925 // error even if the section is not read-only.
 926
 927 void
 928 Target_x86_64::Scan::check_non_pic(Relobj* object, unsigned int r_type)
 929 {
 930   switch (r_type)
 931     {
 932       // These are the relocation types supported by glibc for x86_64.
 933     case elfcpp::R_X86_64_RELATIVE:
 934     case elfcpp::R_X86_64_GLOB_DAT:
 935     case elfcpp::R_X86_64_JUMP_SLOT:
 936     case elfcpp::R_X86_64_DTPMOD64:
 937     case elfcpp::R_X86_64_DTPOFF64:
 938     case elfcpp::R_X86_64_TPOFF64:
 939     case elfcpp::R_X86_64_64:
 940     case elfcpp::R_X86_64_32:
 941     case elfcpp::R_X86_64_PC32:
 942     case elfcpp::R_X86_64_COPY:
 943       return;
 944
 945     default:
 946       // This prevents us from issuing more than one error per reloc
 947       // section.  But we can still wind up issuing more than one
 948       // error per object file.
 949       if (this->issued_non_pic_error_)
 950         return;
 951       object->error(_("requires unsupported dynamic reloc; "
 952                       "recompile with -fPIC"));
 953       this->issued_non_pic_error_ = true;
 954       return;
 955
 956     case elfcpp::R_X86_64_NONE:
 957       gold_unreachable();
 958     }
 959 }
 960
 961 // Scan a relocation for a local symbol.
 962
 963 inline void
 964 Target_x86_64::Scan::local(const General_options&,
 965                            Symbol_table* symtab,
 966                            Layout* layout,
 967                            Target_x86_64* target,
 968                            Sized_relobj<64, false>* object,
 969                            unsigned int data_shndx,
 970                            Output_section* output_section,
 971                            const elfcpp::Rela<64, false>& reloc,
 972                            unsigned int r_type,
 973                            const elfcpp::Sym<64, false>& lsym)
 974 {
 975   switch (r_type)
 976     {
 977     case elfcpp::R_X86_64_NONE:
 978     case elfcpp::R_386_GNU_VTINHERIT:
 979     case elfcpp::R_386_GNU_VTENTRY:
 980       break;
 981
 982     case elfcpp::R_X86_64_64:
 983       // If building a shared library (or a position-independent
 984       // executable), we need to create a dynamic relocation for this
 985       // location.  The relocation applied at link time will apply the
 986       // link-time value, so we flag the location with an
 987       // R_X86_64_RELATIVE relocation so the dynamic loader can
 988       // relocate it easily.
 989       if (parameters->options().output_is_position_independent())
 990         {
 991           unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
 992           Reloc_section* rela_dyn = target->rela_dyn_section(layout);
 993           rela_dyn->add_local_relative(object, r_sym,
 994                                        elfcpp::R_X86_64_RELATIVE,
 995                                        output_section, data_shndx,
 996                                        reloc.get_r_offset(),
 997                                        reloc.get_r_addend());
 998         }
 999       break;
1000
1001     case elfcpp::R_X86_64_32:
1002     case elfcpp::R_X86_64_32S:
1003     case elfcpp::R_X86_64_16:
1004     case elfcpp::R_X86_64_8:
1005       // If building a shared library (or a position-independent
1006       // executable), we need to create a dynamic relocation for this
1007       // location.  We can't use an R_X86_64_RELATIVE relocation
1008       // because that is always a 64-bit relocation.
1009       if (parameters->options().output_is_position_independent())
1010         {
1011           this->check_non_pic(object, r_type);
1012
1013           Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1014           unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
1015           if (lsym.get_st_type() != elfcpp::STT_SECTION)
1016             rela_dyn->add_local(object, r_sym, r_type, output_section,
1017                                 data_shndx, reloc.get_r_offset(),
1018                                 reloc.get_r_addend());
1019           else
1020             {
1021               gold_assert(lsym.get_st_value() == 0);
1022               unsigned int shndx = lsym.get_st_shndx();
1023               bool is_ordinary;
1024               shndx = object->adjust_sym_shndx(r_sym, shndx,
1025                                                &is_ordinary);
1026               if (!is_ordinary)
1027                 object->error(_("section symbol %u has bad shndx %u"),
1028                               r_sym, shndx);
1029               else
1030                 rela_dyn->add_local_section(object, shndx,
1031                                             r_type, output_section,
1032                                             data_shndx, reloc.get_r_offset(),
1033                                             reloc.get_r_addend());
1034             }
1035         }
1036       break;
1037
1038     case elfcpp::R_X86_64_PC64:
1039     case elfcpp::R_X86_64_PC32:
1040     case elfcpp::R_X86_64_PC16:
1041     case elfcpp::R_X86_64_PC8:
1042       break;
1043
1044     case elfcpp::R_X86_64_PLT32:
1045       // Since we know this is a local symbol, we can handle this as a
1046       // PC32 reloc.
1047       break;
1048
1049     case elfcpp::R_X86_64_GOTPC32:
1050     case elfcpp::R_X86_64_GOTOFF64:
1051     case elfcpp::R_X86_64_GOTPC64:
1052     case elfcpp::R_X86_64_PLTOFF64:
1053       // We need a GOT section.
1054       target->got_section(symtab, layout);
1055       // For PLTOFF64, we'd normally want a PLT section, but since we
1056       // know this is a local symbol, no PLT is needed.
1057       break;
1058
1059     case elfcpp::R_X86_64_GOT64:
1060     case elfcpp::R_X86_64_GOT32:
1061     case elfcpp::R_X86_64_GOTPCREL64:
1062     case elfcpp::R_X86_64_GOTPCREL:
1063     case elfcpp::R_X86_64_GOTPLT64:
1064       {
1065         // The symbol requires a GOT entry.
1066         Output_data_got<64, false>* got = target->got_section(symtab, layout);
1067         unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
1068         if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
1069           {
1070             // If we are generating a shared object, we need to add a
1071             // dynamic relocation for this symbol's GOT entry.
1072             if (parameters->options().output_is_position_independent())
1073               {
1074                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1075                 // R_X86_64_RELATIVE assumes a 64-bit relocation.
1076                 if (r_type != elfcpp::R_X86_64_GOT32)
1077                   rela_dyn->add_local_relative(
1078                       object, r_sym, elfcpp::R_X86_64_RELATIVE, got,
1079                       object->local_got_offset(r_sym, GOT_TYPE_STANDARD), 0);
1080                 else
1081                   {
1082                     this->check_non_pic(object, r_type);
1083
1084                     gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
1085                     rela_dyn->add_local(
1086                         object, r_sym, r_type, got,
1087                         object->local_got_offset(r_sym, GOT_TYPE_STANDARD), 0);
1088                   }
1089               }
1090           }
1091         // For GOTPLT64, we'd normally want a PLT section, but since
1092         // we know this is a local symbol, no PLT is needed.
1093       }
1094       break;
1095
1096     case elfcpp::R_X86_64_COPY:
1097     case elfcpp::R_X86_64_GLOB_DAT:
1098     case elfcpp::R_X86_64_JUMP_SLOT:
1099     case elfcpp::R_X86_64_RELATIVE:
1100       // These are outstanding tls relocs, which are unexpected when linking
1101     case elfcpp::R_X86_64_TPOFF64:
1102     case elfcpp::R_X86_64_DTPMOD64:
1103     case elfcpp::R_X86_64_TLSDESC:
1104       gold_error(_("%s: unexpected reloc %u in object file"),
1105                  object->name().c_str(), r_type);
1106       break;
1107
1108       // These are initial tls relocs, which are expected when linking
1109     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
1110     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
1111     case elfcpp::R_X86_64_TLSDESC_CALL:
1112     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
1113     case elfcpp::R_X86_64_DTPOFF32:
1114     case elfcpp::R_X86_64_DTPOFF64:
1115     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
1116     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
1117       {
1118         bool output_is_shared = parameters->options().shared();
1119         const tls::Tls_optimization optimized_type
1120             = Target_x86_64::optimize_tls_reloc(!output_is_shared, r_type);
1121         switch (r_type)
1122           {
1123           case elfcpp::R_X86_64_TLSGD:       // General-dynamic
1124             if (optimized_type == tls::TLSOPT_NONE)
1125               {
1126                 // Create a pair of GOT entries for the module index and
1127                 // dtv-relative offset.
1128                 Output_data_got<64, false>* got
1129                     = target->got_section(symtab, layout);
1130                 unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
1131                 unsigned int shndx = lsym.get_st_shndx();
1132                 bool is_ordinary;
1133                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1134                 if (!is_ordinary)
1135                   object->error(_("local symbol %u has bad shndx %u"),
1136                               r_sym, shndx);
1137                 else
1138                   got->add_local_pair_with_rela(object, r_sym,
1139                                                 shndx,
1140                                                 GOT_TYPE_TLS_PAIR,
1141                                                 target->rela_dyn_section(layout),
1142                                                 elfcpp::R_X86_64_DTPMOD64, 0);
1143               }
1144             else if (optimized_type != tls::TLSOPT_TO_LE)
1145               unsupported_reloc_local(object, r_type);
1146             break;
1147
1148           case elfcpp::R_X86_64_GOTPC32_TLSDESC:
1149             target->define_tls_base_symbol(symtab, layout);
1150             if (optimized_type == tls::TLSOPT_NONE)
1151               {
1152                 // Create reserved PLT and GOT entries for the resolver.
1153                 target->reserve_tlsdesc_entries(symtab, layout);
1154
1155                 // Generate a double GOT entry with an R_X86_64_TLSDESC reloc.
1156                 Output_data_got<64, false>* got
1157                     = target->got_section(symtab, layout);
1158                 unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
1159                 unsigned int shndx = lsym.get_st_shndx();
1160                 bool is_ordinary;
1161                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1162                 if (!is_ordinary)
1163                   object->error(_("local symbol %u has bad shndx %u"),
1164                               r_sym, shndx);
1165                 else
1166                   got->add_local_pair_with_rela(object, r_sym,
1167                                                 shndx,
1168                                                 GOT_TYPE_TLS_DESC,
1169                                                 target->rela_dyn_section(layout),
1170                                                 elfcpp::R_X86_64_TLSDESC, 0);
1171               }
1172             else if (optimized_type != tls::TLSOPT_TO_LE)
1173               unsupported_reloc_local(object, r_type);
1174             break;
1175
1176           case elfcpp::R_X86_64_TLSDESC_CALL:
1177             break;
1178
1179           case elfcpp::R_X86_64_TLSLD:       // Local-dynamic
1180             if (optimized_type == tls::TLSOPT_NONE)
1181               {
1182                 // Create a GOT entry for the module index.
1183                 target->got_mod_index_entry(symtab, layout, object);
1184               }
1185             else if (optimized_type != tls::TLSOPT_TO_LE)
1186               unsupported_reloc_local(object, r_type);
1187             break;
1188
1189           case elfcpp::R_X86_64_DTPOFF32:
1190           case elfcpp::R_X86_64_DTPOFF64:
1191             break;
1192
1193           case elfcpp::R_X86_64_GOTTPOFF:    // Initial-exec
1194             layout->set_has_static_tls();
1195             if (optimized_type == tls::TLSOPT_NONE)
1196               {
1197                 // Create a GOT entry for the tp-relative offset.
1198                 Output_data_got<64, false>* got
1199                     = target->got_section(symtab, layout);
1200                 unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
1201                 got->add_local_with_rela(object, r_sym, GOT_TYPE_TLS_OFFSET,
1202                                          target->rela_dyn_section(layout),
1203                                          elfcpp::R_X86_64_TPOFF64);
1204               }
1205             else if (optimized_type != tls::TLSOPT_TO_LE)
1206               unsupported_reloc_local(object, r_type);
1207             break;
1208
1209           case elfcpp::R_X86_64_TPOFF32:     // Local-exec
1210             layout->set_has_static_tls();
1211             if (output_is_shared)
1212               unsupported_reloc_local(object, r_type);
1213             break;
1214
1215           default:
1216             gold_unreachable();
1217           }
1218       }
1219       break;
1220
1221     case elfcpp::R_X86_64_SIZE32:
1222     case elfcpp::R_X86_64_SIZE64:
1223     default:
1224       gold_error(_("%s: unsupported reloc %u against local symbol"),
1225                  object->name().c_str(), r_type);
1226       break;
1227     }
1228 }
1229
1230
1231 // Report an unsupported relocation against a global symbol.
1232
1233 void
1234 Target_x86_64::Scan::unsupported_reloc_global(Sized_relobj<64, false>* object,
1235                                               unsigned int r_type,
1236                                               Symbol* gsym)
1237 {
1238   gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1239              object->name().c_str(), r_type, gsym->demangled_name().c_str());
1240 }
1241
1242 // Scan a relocation for a global symbol.
1243
1244 inline void
1245 Target_x86_64::Scan::global(const General_options&,
1246                             Symbol_table* symtab,
1247                             Layout* layout,
1248                             Target_x86_64* target,
1249                             Sized_relobj<64, false>* object,
1250                             unsigned int data_shndx,
1251                             Output_section* output_section,
1252                             const elfcpp::Rela<64, false>& reloc,
1253                             unsigned int r_type,
1254                             Symbol* gsym)
1255 {
1256   switch (r_type)
1257     {
1258     case elfcpp::R_X86_64_NONE:
1259     case elfcpp::R_386_GNU_VTINHERIT:
1260     case elfcpp::R_386_GNU_VTENTRY:
1261       break;
1262
1263     case elfcpp::R_X86_64_64:
1264     case elfcpp::R_X86_64_32:
1265     case elfcpp::R_X86_64_32S:
1266     case elfcpp::R_X86_64_16:
1267     case elfcpp::R_X86_64_8:
1268       {
1269         // Make a PLT entry if necessary.
1270         if (gsym->needs_plt_entry())
1271           {
1272             target->make_plt_entry(symtab, layout, gsym);
1273             // Since this is not a PC-relative relocation, we may be
1274             // taking the address of a function. In that case we need to
1275             // set the entry in the dynamic symbol table to the address of
1276             // the PLT entry.
1277             if (gsym->is_from_dynobj() && !parameters->options().shared())
1278               gsym->set_needs_dynsym_value();
1279           }
1280         // Make a dynamic relocation if necessary.
1281         if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
1282           {
1283             if (target->may_need_copy_reloc(gsym))
1284               {
1285                 target->copy_reloc(symtab, layout, object,
1286                                    data_shndx, output_section, gsym, reloc);
1287               }
1288             else if (r_type == elfcpp::R_X86_64_64
1289                      && gsym->can_use_relative_reloc(false))
1290               {
1291                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1292                 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_RELATIVE,
1293                                               output_section, object,
1294                                               data_shndx, reloc.get_r_offset(),
1295                                               reloc.get_r_addend());
1296               }
1297             else
1298               {
1299                 this->check_non_pic(object, r_type);
1300                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1301                 rela_dyn->add_global(gsym, r_type, output_section, object,
1302                                      data_shndx, reloc.get_r_offset(),
1303                                      reloc.get_r_addend());
1304               }
1305           }
1306       }
1307       break;
1308
1309     case elfcpp::R_X86_64_PC64:
1310     case elfcpp::R_X86_64_PC32:
1311     case elfcpp::R_X86_64_PC16:
1312     case elfcpp::R_X86_64_PC8:
1313       {
1314         // Make a PLT entry if necessary.
1315         if (gsym->needs_plt_entry())
1316           target->make_plt_entry(symtab, layout, gsym);
1317         // Make a dynamic relocation if necessary.
1318         int flags = Symbol::NON_PIC_REF;
1319         if (gsym->type() == elfcpp::STT_FUNC)
1320           flags |= Symbol::FUNCTION_CALL;
1321         if (gsym->needs_dynamic_reloc(flags))
1322           {
1323             if (target->may_need_copy_reloc(gsym))
1324               {
1325                 target->copy_reloc(symtab, layout, object,
1326                                    data_shndx, output_section, gsym, reloc);
1327               }
1328             else
1329               {
1330                 this->check_non_pic(object, r_type);
1331                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1332                 rela_dyn->add_global(gsym, r_type, output_section, object,
1333                                      data_shndx, reloc.get_r_offset(),
1334                                      reloc.get_r_addend());
1335               }
1336           }
1337       }
1338       break;
1339
1340     case elfcpp::R_X86_64_GOT64:
1341     case elfcpp::R_X86_64_GOT32:
1342     case elfcpp::R_X86_64_GOTPCREL64:
1343     case elfcpp::R_X86_64_GOTPCREL:
1344     case elfcpp::R_X86_64_GOTPLT64:
1345       {
1346         // The symbol requires a GOT entry.
1347         Output_data_got<64, false>* got = target->got_section(symtab, layout);
1348         if (gsym->final_value_is_known())
1349           got->add_global(gsym, GOT_TYPE_STANDARD);
1350         else
1351           {
1352             // If this symbol is not fully resolved, we need to add a
1353             // dynamic relocation for it.
1354             Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1355             if (gsym->is_from_dynobj()
1356                 || gsym->is_undefined()
1357                 || gsym->is_preemptible())
1358               got->add_global_with_rela(gsym, GOT_TYPE_STANDARD, rela_dyn,
1359                                         elfcpp::R_X86_64_GLOB_DAT);
1360             else
1361               {
1362                 if (got->add_global(gsym, GOT_TYPE_STANDARD))
1363                   rela_dyn->add_global_relative(
1364                       gsym, elfcpp::R_X86_64_RELATIVE, got,
1365                       gsym->got_offset(GOT_TYPE_STANDARD), 0);
1366               }
1367           }
1368         // For GOTPLT64, we also need a PLT entry (but only if the
1369         // symbol is not fully resolved).
1370         if (r_type == elfcpp::R_X86_64_GOTPLT64
1371             && !gsym->final_value_is_known())
1372           target->make_plt_entry(symtab, layout, gsym);
1373       }
1374       break;
1375
1376     case elfcpp::R_X86_64_PLT32:
1377       // If the symbol is fully resolved, this is just a PC32 reloc.
1378       // Otherwise we need a PLT entry.
1379       if (gsym->final_value_is_known())
1380         break;
1381       // If building a shared library, we can also skip the PLT entry
1382       // if the symbol is defined in the output file and is protected
1383       // or hidden.
1384       if (gsym->is_defined()
1385           && !gsym->is_from_dynobj()
1386           && !gsym->is_preemptible())
1387         break;
1388       target->make_plt_entry(symtab, layout, gsym);
1389       break;
1390
1391     case elfcpp::R_X86_64_GOTPC32:
1392     case elfcpp::R_X86_64_GOTOFF64:
1393     case elfcpp::R_X86_64_GOTPC64:
1394     case elfcpp::R_X86_64_PLTOFF64:
1395       // We need a GOT section.
1396       target->got_section(symtab, layout);
1397       // For PLTOFF64, we also need a PLT entry (but only if the
1398       // symbol is not fully resolved).
1399       if (r_type == elfcpp::R_X86_64_PLTOFF64
1400           && !gsym->final_value_is_known())
1401         target->make_plt_entry(symtab, layout, gsym);
1402       break;
1403
1404     case elfcpp::R_X86_64_COPY:
1405     case elfcpp::R_X86_64_GLOB_DAT:
1406     case elfcpp::R_X86_64_JUMP_SLOT:
1407     case elfcpp::R_X86_64_RELATIVE:
1408       // These are outstanding tls relocs, which are unexpected when linking
1409     case elfcpp::R_X86_64_TPOFF64:
1410     case elfcpp::R_X86_64_DTPMOD64:
1411     case elfcpp::R_X86_64_TLSDESC:
1412       gold_error(_("%s: unexpected reloc %u in object file"),
1413                  object->name().c_str(), r_type);
1414       break;
1415
1416       // These are initial tls relocs, which are expected for global()
1417     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
1418     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
1419     case elfcpp::R_X86_64_TLSDESC_CALL:
1420     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
1421     case elfcpp::R_X86_64_DTPOFF32:
1422     case elfcpp::R_X86_64_DTPOFF64:
1423     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
1424     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
1425       {
1426         const bool is_final = gsym->final_value_is_known();
1427         const tls::Tls_optimization optimized_type
1428             = Target_x86_64::optimize_tls_reloc(is_final, r_type);
1429         switch (r_type)
1430           {
1431           case elfcpp::R_X86_64_TLSGD:       // General-dynamic
1432             if (optimized_type == tls::TLSOPT_NONE)
1433               {
1434                 // Create a pair of GOT entries for the module index and
1435                 // dtv-relative offset.
1436                 Output_data_got<64, false>* got
1437                     = target->got_section(symtab, layout);
1438                 got->add_global_pair_with_rela(gsym, GOT_TYPE_TLS_PAIR,
1439                                                target->rela_dyn_section(layout),
1440                                                elfcpp::R_X86_64_DTPMOD64,
1441                                                elfcpp::R_X86_64_DTPOFF64);
1442               }
1443             else if (optimized_type == tls::TLSOPT_TO_IE)
1444               {
1445                 // Create a GOT entry for the tp-relative offset.
1446                 Output_data_got<64, false>* got
1447                     = target->got_section(symtab, layout);
1448                 got->add_global_with_rela(gsym, GOT_TYPE_TLS_OFFSET,
1449                                           target->rela_dyn_section(layout),
1450                                           elfcpp::R_X86_64_TPOFF64);
1451               }
1452             else if (optimized_type != tls::TLSOPT_TO_LE)
1453               unsupported_reloc_global(object, r_type, gsym);
1454             break;
1455
1456           case elfcpp::R_X86_64_GOTPC32_TLSDESC:
1457             target->define_tls_base_symbol(symtab, layout);
1458             if (optimized_type == tls::TLSOPT_NONE)
1459               {
1460                 // Create reserved PLT and GOT entries for the resolver.
1461                 target->reserve_tlsdesc_entries(symtab, layout);
1462
1463                 // Create a double GOT entry with an R_X86_64_TLSDESC reloc.
1464                 Output_data_got<64, false>* got
1465                     = target->got_section(symtab, layout);
1466                 got->add_global_pair_with_rela(gsym, GOT_TYPE_TLS_DESC,
1467                                                target->rela_dyn_section(layout),
1468                                                elfcpp::R_X86_64_TLSDESC, 0);
1469               }
1470             else if (optimized_type == tls::TLSOPT_TO_IE)
1471               {
1472                 // Create a GOT entry for the tp-relative offset.
1473                 Output_data_got<64, false>* got
1474                     = target->got_section(symtab, layout);
1475                 got->add_global_with_rela(gsym, GOT_TYPE_TLS_OFFSET,
1476                                           target->rela_dyn_section(layout),
1477                                           elfcpp::R_X86_64_TPOFF64);
1478               }
1479             else if (optimized_type != tls::TLSOPT_TO_LE)
1480               unsupported_reloc_global(object, r_type, gsym);
1481             break;
1482
1483           case elfcpp::R_X86_64_TLSDESC_CALL:
1484             break;
1485
1486           case elfcpp::R_X86_64_TLSLD:       // Local-dynamic
1487             if (optimized_type == tls::TLSOPT_NONE)
1488               {
1489                 // Create a GOT entry for the module index.
1490                 target->got_mod_index_entry(symtab, layout, object);
1491               }
1492             else if (optimized_type != tls::TLSOPT_TO_LE)
1493               unsupported_reloc_global(object, r_type, gsym);
1494             break;
1495
1496           case elfcpp::R_X86_64_DTPOFF32:
1497           case elfcpp::R_X86_64_DTPOFF64:
1498             break;
1499
1500           case elfcpp::R_X86_64_GOTTPOFF:    // Initial-exec
1501             layout->set_has_static_tls();
1502             if (optimized_type == tls::TLSOPT_NONE)
1503               {
1504                 // Create a GOT entry for the tp-relative offset.
1505                 Output_data_got<64, false>* got
1506                     = target->got_section(symtab, layout);
1507                 got->add_global_with_rela(gsym, GOT_TYPE_TLS_OFFSET,
1508                                           target->rela_dyn_section(layout),
1509                                           elfcpp::R_X86_64_TPOFF64);
1510               }
1511             else if (optimized_type != tls::TLSOPT_TO_LE)
1512               unsupported_reloc_global(object, r_type, gsym);
1513             break;
1514
1515           case elfcpp::R_X86_64_TPOFF32:     // Local-exec
1516             layout->set_has_static_tls();
1517             if (parameters->options().shared())
1518               unsupported_reloc_local(object, r_type);
1519             break;
1520
1521           default:
1522             gold_unreachable();
1523           }
1524       }
1525       break;
1526
1527     case elfcpp::R_X86_64_SIZE32:
1528     case elfcpp::R_X86_64_SIZE64:
1529     default:
1530       gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1531                  object->name().c_str(), r_type,
1532                  gsym->demangled_name().c_str());
1533       break;
1534     }
1535 }
1536
1537 // Scan relocations for a section.
1538
1539 void
1540 Target_x86_64::scan_relocs(const General_options& options,
1541                            Symbol_table* symtab,
1542                            Layout* layout,
1543                            Sized_relobj<64, false>* object,
1544                            unsigned int data_shndx,
1545                            unsigned int sh_type,
1546                            const unsigned char* prelocs,
1547                            size_t reloc_count,
1548                            Output_section* output_section,
1549                            bool needs_special_offset_handling,
1550                            size_t local_symbol_count,
1551                            const unsigned char* plocal_symbols)
1552 {
1553   if (sh_type == elfcpp::SHT_REL)
1554     {
1555       gold_error(_("%s: unsupported REL reloc section"),
1556                  object->name().c_str());
1557       return;
1558     }
1559
1560   gold::scan_relocs<64, false, Target_x86_64, elfcpp::SHT_RELA,
1561       Target_x86_64::Scan>(
1562     options,
1563     symtab,
1564     layout,
1565     this,
1566     object,
1567     data_shndx,
1568     prelocs,
1569     reloc_count,
1570     output_section,
1571     needs_special_offset_handling,
1572     local_symbol_count,
1573     plocal_symbols);
1574 }
1575
1576 // Finalize the sections.
1577
1578 void
1579 Target_x86_64::do_finalize_sections(Layout* layout)
1580 {
1581   // Fill in some more dynamic tags.
1582   Output_data_dynamic* const odyn = layout->dynamic_data();
1583   if (odyn != NULL)
1584     {
1585       if (this->got_plt_ != NULL)
1586         odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_);
1587
1588       if (this->plt_ != NULL)
1589         {
1590           const Output_data* od = this->plt_->rel_plt();
1591           odyn->add_section_size(elfcpp::DT_PLTRELSZ, od);
1592           odyn->add_section_address(elfcpp::DT_JMPREL, od);
1593           odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_RELA);
1594           if (this->plt_->has_tlsdesc_entry())
1595             {
1596               unsigned int plt_offset = this->plt_->get_tlsdesc_plt_offset();
1597               unsigned int got_offset = this->plt_->get_tlsdesc_got_offset();
1598               this->got_->finalize_data_size();
1599               odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_PLT,
1600                                             this->plt_, plt_offset);
1601               odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_GOT,
1602                                             this->got_, got_offset);
1603             }
1604         }
1605
1606       if (this->rela_dyn_ != NULL)
1607         {
1608           const Output_data* od = this->rela_dyn_;
1609           odyn->add_section_address(elfcpp::DT_RELA, od);
1610           odyn->add_section_size(elfcpp::DT_RELASZ, od);
1611           odyn->add_constant(elfcpp::DT_RELAENT,
1612                              elfcpp::Elf_sizes<64>::rela_size);
1613         }
1614
1615       if (!parameters->options().shared())
1616         {
1617           // The value of the DT_DEBUG tag is filled in by the dynamic
1618           // linker at run time, and used by the debugger.
1619           odyn->add_constant(elfcpp::DT_DEBUG, 0);
1620         }
1621     }
1622
1623   // Emit any relocs we saved in an attempt to avoid generating COPY
1624   // relocs.
1625   if (this->copy_relocs_.any_saved_relocs())
1626     this->copy_relocs_.emit(this->rela_dyn_section(layout));
1627 }
1628
1629 // Perform a relocation.
1630
1631 inline bool
1632 Target_x86_64::Relocate::relocate(const Relocate_info<64, false>* relinfo,
1633                                   Target_x86_64* target,
1634                                   size_t relnum,
1635                                   const elfcpp::Rela<64, false>& rela,
1636                                   unsigned int r_type,
1637                                   const Sized_symbol<64>* gsym,
1638                                   const Symbol_value<64>* psymval,
1639                                   unsigned char* view,
1640                                   elfcpp::Elf_types<64>::Elf_Addr address,
1641                                   section_size_type view_size)
1642 {
1643   if (this->skip_call_tls_get_addr_)
1644     {
1645       if (r_type != elfcpp::R_X86_64_PLT32
1646           || gsym == NULL
1647           || strcmp(gsym->name(), "__tls_get_addr") != 0)
1648         {
1649           gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
1650                                  _("missing expected TLS relocation"));
1651         }
1652       else
1653         {
1654           this->skip_call_tls_get_addr_ = false;
1655           return false;
1656         }
1657     }
1658
1659   // Pick the value to use for symbols defined in shared objects.
1660   Symbol_value<64> symval;
1661   if (gsym != NULL
1662       && (gsym->is_from_dynobj()
1663           || (parameters->options().shared()
1664               && (gsym->is_undefined() || gsym->is_preemptible())))
1665       && gsym->has_plt_offset())
1666     {
1667       symval.set_output_value(target->plt_section()->address()
1668                               + gsym->plt_offset());
1669       psymval = &symval;
1670     }
1671
1672   const Sized_relobj<64, false>* object = relinfo->object;
1673   const elfcpp::Elf_Xword addend = rela.get_r_addend();
1674
1675   // Get the GOT offset if needed.
1676   // The GOT pointer points to the end of the GOT section.
1677   // We need to subtract the size of the GOT section to get
1678   // the actual offset to use in the relocation.
1679   bool have_got_offset = false;
1680   unsigned int got_offset = 0;
1681   switch (r_type)
1682     {
1683     case elfcpp::R_X86_64_GOT32:
1684     case elfcpp::R_X86_64_GOT64:
1685     case elfcpp::R_X86_64_GOTPLT64:
1686     case elfcpp::R_X86_64_GOTPCREL:
1687     case elfcpp::R_X86_64_GOTPCREL64:
1688       if (gsym != NULL)
1689         {
1690           gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
1691           got_offset = gsym->got_offset(GOT_TYPE_STANDARD) - target->got_size();
1692         }
1693       else
1694         {
1695           unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
1696           gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
1697           got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
1698                         - target->got_size());
1699         }
1700       have_got_offset = true;
1701       break;
1702
1703     default:
1704       break;
1705     }
1706
1707   switch (r_type)
1708     {
1709     case elfcpp::R_X86_64_NONE:
1710     case elfcpp::R_386_GNU_VTINHERIT:
1711     case elfcpp::R_386_GNU_VTENTRY:
1712       break;
1713
1714     case elfcpp::R_X86_64_64:
1715       Relocate_functions<64, false>::rela64(view, object, psymval, addend);
1716       break;
1717
1718     case elfcpp::R_X86_64_PC64:
1719       Relocate_functions<64, false>::pcrela64(view, object, psymval, addend,
1720                                               address);
1721       break;
1722
1723     case elfcpp::R_X86_64_32:
1724       // FIXME: we need to verify that value + addend fits into 32 bits:
1725       //    uint64_t x = value + addend;
1726       //    x == static_cast<uint64_t>(static_cast<uint32_t>(x))
1727       // Likewise for other <=32-bit relocations (but see R_X86_64_32S).
1728       Relocate_functions<64, false>::rela32(view, object, psymval, addend);
1729       break;
1730
1731     case elfcpp::R_X86_64_32S:
1732       // FIXME: we need to verify that value + addend fits into 32 bits:
1733       //    int64_t x = value + addend;   // note this quantity is signed!
1734       //    x == static_cast<int64_t>(static_cast<int32_t>(x))
1735       Relocate_functions<64, false>::rela32(view, object, psymval, addend);
1736       break;
1737
1738     case elfcpp::R_X86_64_PC32:
1739       Relocate_functions<64, false>::pcrela32(view, object, psymval, addend,
1740                                               address);
1741       break;
1742
1743     case elfcpp::R_X86_64_16:
1744       Relocate_functions<64, false>::rela16(view, object, psymval, addend);
1745       break;
1746
1747     case elfcpp::R_X86_64_PC16:
1748       Relocate_functions<64, false>::pcrela16(view, object, psymval, addend,
1749                                               address);
1750       break;
1751
1752     case elfcpp::R_X86_64_8:
1753       Relocate_functions<64, false>::rela8(view, object, psymval, addend);
1754       break;
1755
1756     case elfcpp::R_X86_64_PC8:
1757       Relocate_functions<64, false>::pcrela8(view, object, psymval, addend,
1758                                              address);
1759       break;
1760
1761     case elfcpp::R_X86_64_PLT32:
1762       gold_assert(gsym == NULL
1763                   || gsym->has_plt_offset()
1764                   || gsym->final_value_is_known()
1765                   || (gsym->is_defined()
1766                       && !gsym->is_from_dynobj()
1767                       && !gsym->is_preemptible()));
1768       // Note: while this code looks the same as for R_X86_64_PC32, it
1769       // behaves differently because psymval was set to point to
1770       // the PLT entry, rather than the symbol, in Scan::global().
1771       Relocate_functions<64, false>::pcrela32(view, object, psymval, addend,
1772                                               address);
1773       break;
1774
1775     case elfcpp::R_X86_64_PLTOFF64:
1776       {
1777         gold_assert(gsym);
1778         gold_assert(gsym->has_plt_offset()
1779                     || gsym->final_value_is_known());
1780         elfcpp::Elf_types<64>::Elf_Addr got_address;
1781         got_address = target->got_section(NULL, NULL)->address();
1782         Relocate_functions<64, false>::rela64(view, object, psymval,
1783                                               addend - got_address);
1784       }
1785
1786     case elfcpp::R_X86_64_GOT32:
1787       gold_assert(have_got_offset);
1788       Relocate_functions<64, false>::rela32(view, got_offset, addend);
1789       break;
1790
1791     case elfcpp::R_X86_64_GOTPC32:
1792       {
1793         gold_assert(gsym);
1794         elfcpp::Elf_types<64>::Elf_Addr value;
1795         value = target->got_plt_section()->address();
1796         Relocate_functions<64, false>::pcrela32(view, value, addend, address);
1797       }
1798       break;
1799
1800     case elfcpp::R_X86_64_GOT64:
1801       // The ABI doc says "Like GOT64, but indicates a PLT entry is needed."
1802       // Since we always add a PLT entry, this is equivalent.
1803     case elfcpp::R_X86_64_GOTPLT64:
1804       gold_assert(have_got_offset);
1805       Relocate_functions<64, false>::rela64(view, got_offset, addend);
1806       break;
1807
1808     case elfcpp::R_X86_64_GOTPC64:
1809       {
1810         gold_assert(gsym);
1811         elfcpp::Elf_types<64>::Elf_Addr value;
1812         value = target->got_plt_section()->address();
1813         Relocate_functions<64, false>::pcrela64(view, value, addend, address);
1814       }
1815       break;
1816
1817     case elfcpp::R_X86_64_GOTOFF64:
1818       {
1819         elfcpp::Elf_types<64>::Elf_Addr value;
1820         value = (psymval->value(object, 0)
1821                  - target->got_plt_section()->address());
1822         Relocate_functions<64, false>::rela64(view, value, addend);
1823       }
1824       break;
1825
1826     case elfcpp::R_X86_64_GOTPCREL:
1827       {
1828         gold_assert(have_got_offset);
1829         elfcpp::Elf_types<64>::Elf_Addr value;
1830         value = target->got_plt_section()->address() + got_offset;
1831         Relocate_functions<64, false>::pcrela32(view, value, addend, address);
1832       }
1833       break;
1834
1835     case elfcpp::R_X86_64_GOTPCREL64:
1836       {
1837         gold_assert(have_got_offset);
1838         elfcpp::Elf_types<64>::Elf_Addr value;
1839         value = target->got_plt_section()->address() + got_offset;
1840         Relocate_functions<64, false>::pcrela64(view, value, addend, address);
1841       }
1842       break;
1843
1844     case elfcpp::R_X86_64_COPY:
1845     case elfcpp::R_X86_64_GLOB_DAT:
1846     case elfcpp::R_X86_64_JUMP_SLOT:
1847     case elfcpp::R_X86_64_RELATIVE:
1848       // These are outstanding tls relocs, which are unexpected when linking
1849     case elfcpp::R_X86_64_TPOFF64:
1850     case elfcpp::R_X86_64_DTPMOD64:
1851     case elfcpp::R_X86_64_TLSDESC:
1852       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
1853                              _("unexpected reloc %u in object file"),
1854                              r_type);
1855       break;
1856
1857       // These are initial tls relocs, which are expected when linking
1858     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
1859     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
1860     case elfcpp::R_X86_64_TLSDESC_CALL:
1861     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
1862     case elfcpp::R_X86_64_DTPOFF32:
1863     case elfcpp::R_X86_64_DTPOFF64:
1864     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
1865     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
1866       this->relocate_tls(relinfo, target, relnum, rela, r_type, gsym, psymval,
1867                          view, address, view_size);
1868       break;
1869
1870     case elfcpp::R_X86_64_SIZE32:
1871     case elfcpp::R_X86_64_SIZE64:
1872     default:
1873       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
1874                              _("unsupported reloc %u"),
1875                              r_type);
1876       break;
1877     }
1878
1879   return true;
1880 }
1881
1882 // Perform a TLS relocation.
1883
1884 inline void
1885 Target_x86_64::Relocate::relocate_tls(const Relocate_info<64, false>* relinfo,
1886                                       Target_x86_64* target,
1887                                       size_t relnum,
1888                                       const elfcpp::Rela<64, false>& rela,
1889                                       unsigned int r_type,
1890                                       const Sized_symbol<64>* gsym,
1891                                       const Symbol_value<64>* psymval,
1892                                       unsigned char* view,
1893                                       elfcpp::Elf_types<64>::Elf_Addr address,
1894                                       section_size_type view_size)
1895 {
1896   Output_segment* tls_segment = relinfo->layout->tls_segment();
1897
1898   const Sized_relobj<64, false>* object = relinfo->object;
1899   const elfcpp::Elf_Xword addend = rela.get_r_addend();
1900
1901   elfcpp::Elf_types<64>::Elf_Addr value = psymval->value(relinfo->object, 0);
1902
1903   const bool is_final = (gsym == NULL
1904                          ? !parameters->options().output_is_position_independent()
1905                          : gsym->final_value_is_known());
1906   const tls::Tls_optimization optimized_type
1907       = Target_x86_64::optimize_tls_reloc(is_final, r_type);
1908   switch (r_type)
1909     {
1910     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
1911       this->saw_tls_block_reloc_ = true;
1912       if (optimized_type == tls::TLSOPT_TO_LE)
1913         {
1914           gold_assert(tls_segment != NULL);
1915           this->tls_gd_to_le(relinfo, relnum, tls_segment,
1916                              rela, r_type, value, view,
1917                              view_size);
1918           break;
1919         }
1920       else
1921         {
1922           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
1923                                    ? GOT_TYPE_TLS_OFFSET
1924                                    : GOT_TYPE_TLS_PAIR);
1925           unsigned int got_offset;
1926           if (gsym != NULL)
1927             {
1928               gold_assert(gsym->has_got_offset(got_type));
1929               got_offset = gsym->got_offset(got_type) - target->got_size();
1930             }
1931           else
1932             {
1933               unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
1934               gold_assert(object->local_has_got_offset(r_sym, got_type));
1935               got_offset = (object->local_got_offset(r_sym, got_type)
1936                             - target->got_size());
1937             }
1938           if (optimized_type == tls::TLSOPT_TO_IE)
1939             {
1940               gold_assert(tls_segment != NULL);
1941               value = target->got_plt_section()->address() + got_offset;
1942               this->tls_gd_to_ie(relinfo, relnum, tls_segment, rela, r_type,
1943                                  value, view, address, view_size);
1944               break;
1945             }
1946           else if (optimized_type == tls::TLSOPT_NONE)
1947             {
1948               // Relocate the field with the offset of the pair of GOT
1949               // entries.
1950               value = target->got_plt_section()->address() + got_offset;
1951               Relocate_functions<64, false>::pcrela32(view, value, addend,
1952                                                       address);
1953               break;
1954             }
1955         }
1956       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
1957                              _("unsupported reloc %u"), r_type);
1958       break;
1959
1960     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
1961     case elfcpp::R_X86_64_TLSDESC_CALL:
1962       this->saw_tls_block_reloc_ = true;
1963       if (optimized_type == tls::TLSOPT_TO_LE)
1964         {
1965           gold_assert(tls_segment != NULL);
1966           this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
1967                                   rela, r_type, value, view,
1968                                   view_size);
1969           break;
1970         }
1971       else
1972         {
1973           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
1974                                    ? GOT_TYPE_TLS_OFFSET
1975                                    : GOT_TYPE_TLS_DESC);
1976           unsigned int got_offset;
1977           if (gsym != NULL)
1978             {
1979               gold_assert(gsym->has_got_offset(got_type));
1980               got_offset = gsym->got_offset(got_type) - target->got_size();
1981             }
1982           else
1983             {
1984               unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
1985               gold_assert(object->local_has_got_offset(r_sym, got_type));
1986               got_offset = (object->local_got_offset(r_sym, got_type)
1987                             - target->got_size());
1988             }
1989           if (optimized_type == tls::TLSOPT_TO_IE)
1990             {
1991               gold_assert(tls_segment != NULL);
1992               value = target->got_plt_section()->address() + got_offset;
1993               this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment,
1994                                       rela, r_type, value, view, address,
1995                                       view_size);
1996               break;
1997             }
1998           else if (optimized_type == tls::TLSOPT_NONE)
1999             {
2000               if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
2001                 {
2002                   // Relocate the field with the offset of the pair of GOT
2003                   // entries.
2004                   value = target->got_plt_section()->address() + got_offset;
2005                   Relocate_functions<64, false>::pcrela32(view, value, addend,
2006                                                           address);
2007                 }
2008               break;
2009             }
2010         }
2011       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
2012                              _("unsupported reloc %u"), r_type);
2013       break;
2014
2015     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
2016       this->saw_tls_block_reloc_ = true;
2017       if (optimized_type == tls::TLSOPT_TO_LE)
2018         {
2019           gold_assert(tls_segment != NULL);
2020           this->tls_ld_to_le(relinfo, relnum, tls_segment, rela, r_type,
2021                              value, view, view_size);
2022           break;
2023         }
2024       else if (optimized_type == tls::TLSOPT_NONE)
2025         {
2026           // Relocate the field with the offset of the GOT entry for
2027           // the module index.
2028           unsigned int got_offset;
2029           got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
2030                         - target->got_size());
2031           value = target->got_plt_section()->address() + got_offset;
2032           Relocate_functions<64, false>::pcrela32(view, value, addend,
2033                                                   address);
2034           break;
2035         }
2036       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
2037                              _("unsupported reloc %u"), r_type);
2038       break;
2039
2040     case elfcpp::R_X86_64_DTPOFF32:
2041       gold_assert(tls_segment != NULL);
2042       if (optimized_type == tls::TLSOPT_TO_LE)
2043         {
2044           // This relocation type is used in debugging information.
2045           // In that case we need to not optimize the value.  If we
2046           // haven't seen a TLSLD reloc, then we assume we should not
2047           // optimize this reloc.
2048           if (this->saw_tls_block_reloc_)
2049             value -= tls_segment->memsz();
2050         }
2051       Relocate_functions<64, false>::rela32(view, value, 0);
2052       break;
2053
2054     case elfcpp::R_X86_64_DTPOFF64:
2055       gold_assert(tls_segment != NULL);
2056       if (optimized_type == tls::TLSOPT_TO_LE)
2057         {
2058           // See R_X86_64_DTPOFF32, just above, for why we test this.
2059           if (this->saw_tls_block_reloc_)
2060             value -= tls_segment->memsz();
2061         }
2062       Relocate_functions<64, false>::rela64(view, value, 0);
2063       break;
2064
2065     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
2066       if (optimized_type == tls::TLSOPT_TO_LE)
2067         {
2068           gold_assert(tls_segment != NULL);
2069           Target_x86_64::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
2070                                                 rela, r_type, value, view,
2071                                                 view_size);
2072           break;
2073         }
2074       else if (optimized_type == tls::TLSOPT_NONE)
2075         {
2076           // Relocate the field with the offset of the GOT entry for
2077           // the tp-relative offset of the symbol.
2078           unsigned int got_offset;
2079           if (gsym != NULL)
2080             {
2081               gold_assert(gsym->has_got_offset(GOT_TYPE_TLS_OFFSET));
2082               got_offset = (gsym->got_offset(GOT_TYPE_TLS_OFFSET)
2083                             - target->got_size());
2084             }
2085           else
2086             {
2087               unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
2088               gold_assert(object->local_has_got_offset(r_sym,
2089                                                        GOT_TYPE_TLS_OFFSET));
2090               got_offset = (object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET)
2091                             - target->got_size());
2092             }
2093           value = target->got_plt_section()->address() + got_offset;
2094           Relocate_functions<64, false>::pcrela32(view, value, addend, address);
2095           break;
2096         }
2097       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
2098                              _("unsupported reloc type %u"),
2099                              r_type);
2100       break;
2101
2102     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
2103       value -= tls_segment->memsz();
2104       Relocate_functions<64, false>::rela32(view, value, 0);
2105       break;
2106     }
2107 }
2108
2109 // Do a relocation in which we convert a TLS General-Dynamic to an
2110 // Initial-Exec.
2111
2112 inline void
2113 Target_x86_64::Relocate::tls_gd_to_ie(const Relocate_info<64, false>* relinfo,
2114                                       size_t relnum,
2115                                       Output_segment*,
2116                                       const elfcpp::Rela<64, false>& rela,
2117                                       unsigned int,
2118                                       elfcpp::Elf_types<64>::Elf_Addr value,
2119                                       unsigned char* view,
2120                                       elfcpp::Elf_types<64>::Elf_Addr address,
2121                                       section_size_type view_size)
2122 {
2123   // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
2124   // .word 0x6666; rex64; call __tls_get_addr
2125   // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
2126
2127   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -4);
2128   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
2129
2130   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2131                  (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
2132   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2133                  (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0));
2134
2135   memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0", 16);
2136
2137   const elfcpp::Elf_Xword addend = rela.get_r_addend();
2138   Relocate_functions<64, false>::pcrela32(view + 8, value, addend - 8, address);
2139
2140   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2141   // We can skip it.
2142   this->skip_call_tls_get_addr_ = true;
2143 }
2144
2145 // Do a relocation in which we convert a TLS General-Dynamic to a
2146 // Local-Exec.
2147
2148 inline void
2149 Target_x86_64::Relocate::tls_gd_to_le(const Relocate_info<64, false>* relinfo,
2150                                       size_t relnum,
2151                                       Output_segment* tls_segment,
2152                                       const elfcpp::Rela<64, false>& rela,
2153                                       unsigned int,
2154                                       elfcpp::Elf_types<64>::Elf_Addr value,
2155                                       unsigned char* view,
2156                                       section_size_type view_size)
2157 {
2158   // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
2159   // .word 0x6666; rex64; call __tls_get_addr
2160   // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
2161
2162   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -4);
2163   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
2164
2165   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2166                  (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
2167   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2168                  (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0));
2169
2170   memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0", 16);
2171
2172   value -= tls_segment->memsz();
2173   Relocate_functions<64, false>::rela32(view + 8, value, 0);
2174
2175   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2176   // We can skip it.
2177   this->skip_call_tls_get_addr_ = true;
2178 }
2179
2180 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
2181
2182 inline void
2183 Target_x86_64::Relocate::tls_desc_gd_to_ie(
2184     const Relocate_info<64, false>* relinfo,
2185     size_t relnum,
2186     Output_segment*,
2187     const elfcpp::Rela<64, false>& rela,
2188     unsigned int r_type,
2189     elfcpp::Elf_types<64>::Elf_Addr value,
2190     unsigned char* view,
2191     elfcpp::Elf_types<64>::Elf_Addr address,
2192     section_size_type view_size)
2193 {
2194   if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
2195     {
2196       // leaq foo@tlsdesc(%rip), %rax
2197       // ==> movq foo@gottpoff(%rip), %rax
2198       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
2199       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
2200       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2201                      view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05);
2202       view[-2] = 0x8b;
2203       const elfcpp::Elf_Xword addend = rela.get_r_addend();
2204       Relocate_functions<64, false>::pcrela32(view, value, addend, address);
2205     }
2206   else
2207     {
2208       // call *foo@tlscall(%rax)
2209       // ==> nop; nop
2210       gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
2211       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
2212       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2213                      view[0] == 0xff && view[1] == 0x10);
2214       view[0] = 0x66;
2215       view[1] = 0x90;
2216     }
2217 }
2218
2219 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
2220
2221 inline void
2222 Target_x86_64::Relocate::tls_desc_gd_to_le(
2223     const Relocate_info<64, false>* relinfo,
2224     size_t relnum,
2225     Output_segment* tls_segment,
2226     const elfcpp::Rela<64, false>& rela,
2227     unsigned int r_type,
2228     elfcpp::Elf_types<64>::Elf_Addr value,
2229     unsigned char* view,
2230     section_size_type view_size)
2231 {
2232   if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
2233     {
2234       // leaq foo@tlsdesc(%rip), %rax
2235       // ==> movq foo@tpoff, %rax
2236       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
2237       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
2238       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2239                      view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05);
2240       view[-2] = 0xc7;
2241       view[-1] = 0xc0;
2242       value -= tls_segment->memsz();
2243       Relocate_functions<64, false>::rela32(view, value, 0);
2244     }
2245   else
2246     {
2247       // call *foo@tlscall(%rax)
2248       // ==> nop; nop
2249       gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
2250       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
2251       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2252                      view[0] == 0xff && view[1] == 0x10);
2253       view[0] = 0x66;
2254       view[1] = 0x90;
2255     }
2256 }
2257
2258 inline void
2259 Target_x86_64::Relocate::tls_ld_to_le(const Relocate_info<64, false>* relinfo,
2260                                       size_t relnum,
2261                                       Output_segment*,
2262                                       const elfcpp::Rela<64, false>& rela,
2263                                       unsigned int,
2264                                       elfcpp::Elf_types<64>::Elf_Addr,
2265                                       unsigned char* view,
2266                                       section_size_type view_size)
2267 {
2268   // leaq foo@tlsld(%rip),%rdi; call __tls_get_addr@plt;
2269   // ... leq foo@dtpoff(%rax),%reg
2270   // ==> .word 0x6666; .byte 0x66; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
2271
2272   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
2273   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 9);
2274
2275   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2276                  view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x3d);
2277
2278   tls::check_tls(relinfo, relnum, rela.get_r_offset(), view[4] == 0xe8);
2279
2280   memcpy(view - 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12);
2281
2282   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2283   // We can skip it.
2284   this->skip_call_tls_get_addr_ = true;
2285 }
2286
2287 // Do a relocation in which we convert a TLS Initial-Exec to a
2288 // Local-Exec.
2289
2290 inline void
2291 Target_x86_64::Relocate::tls_ie_to_le(const Relocate_info<64, false>* relinfo,
2292                                       size_t relnum,
2293                                       Output_segment* tls_segment,
2294                                       const elfcpp::Rela<64, false>& rela,
2295                                       unsigned int,
2296                                       elfcpp::Elf_types<64>::Elf_Addr value,
2297                                       unsigned char* view,
2298                                       section_size_type view_size)
2299 {
2300   // We need to examine the opcodes to figure out which instruction we
2301   // are looking at.
2302
2303   // movq foo@gottpoff(%rip),%reg  ==>  movq $YY,%reg
2304   // addq foo@gottpoff(%rip),%reg  ==>  addq $YY,%reg
2305
2306   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
2307   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
2308
2309   unsigned char op1 = view[-3];
2310   unsigned char op2 = view[-2];
2311   unsigned char op3 = view[-1];
2312   unsigned char reg = op3 >> 3;
2313
2314   if (op2 == 0x8b)
2315     {
2316       // movq
2317       if (op1 == 0x4c)
2318         view[-3] = 0x49;
2319       view[-2] = 0xc7;
2320       view[-1] = 0xc0 | reg;
2321     }
2322   else if (reg == 4)
2323     {
2324       // Special handling for %rsp.
2325       if (op1 == 0x4c)
2326         view[-3] = 0x49;
2327       view[-2] = 0x81;
2328       view[-1] = 0xc0 | reg;
2329     }
2330   else
2331     {
2332       // addq
2333       if (op1 == 0x4c)
2334         view[-3] = 0x4d;
2335       view[-2] = 0x8d;
2336       view[-1] = 0x80 | reg | (reg << 3);
2337     }
2338
2339   value -= tls_segment->memsz();
2340   Relocate_functions<64, false>::rela32(view, value, 0);
2341 }
2342
2343 // Relocate section data.
2344
2345 void
2346 Target_x86_64::relocate_section(const Relocate_info<64, false>* relinfo,
2347                                 unsigned int sh_type,
2348                                 const unsigned char* prelocs,
2349                                 size_t reloc_count,
2350                                 Output_section* output_section,
2351                                 bool needs_special_offset_handling,
2352                                 unsigned char* view,
2353                                 elfcpp::Elf_types<64>::Elf_Addr address,
2354                                 section_size_type view_size)
2355 {
2356   gold_assert(sh_type == elfcpp::SHT_RELA);
2357
2358   gold::relocate_section<64, false, Target_x86_64, elfcpp::SHT_RELA,
2359                          Target_x86_64::Relocate>(
2360     relinfo,
2361     this,
2362     prelocs,
2363     reloc_count,
2364     output_section,
2365     needs_special_offset_handling,
2366     view,
2367     address,
2368     view_size);
2369 }
2370
2371 // Return the size of a relocation while scanning during a relocatable
2372 // link.
2373
2374 unsigned int
2375 Target_x86_64::Relocatable_size_for_reloc::get_size_for_reloc(
2376     unsigned int r_type,
2377     Relobj* object)
2378 {
2379   switch (r_type)
2380     {
2381     case elfcpp::R_X86_64_NONE:
2382     case elfcpp::R_386_GNU_VTINHERIT:
2383     case elfcpp::R_386_GNU_VTENTRY:
2384     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
2385     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
2386     case elfcpp::R_X86_64_TLSDESC_CALL:
2387     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
2388     case elfcpp::R_X86_64_DTPOFF32:
2389     case elfcpp::R_X86_64_DTPOFF64:
2390     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
2391     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
2392       return 0;
2393
2394     case elfcpp::R_X86_64_64:
2395     case elfcpp::R_X86_64_PC64:
2396     case elfcpp::R_X86_64_GOTOFF64:
2397     case elfcpp::R_X86_64_GOTPC64:
2398     case elfcpp::R_X86_64_PLTOFF64:
2399     case elfcpp::R_X86_64_GOT64:
2400     case elfcpp::R_X86_64_GOTPCREL64:
2401     case elfcpp::R_X86_64_GOTPCREL:
2402     case elfcpp::R_X86_64_GOTPLT64:
2403       return 8;
2404
2405     case elfcpp::R_X86_64_32:
2406     case elfcpp::R_X86_64_32S:
2407     case elfcpp::R_X86_64_PC32:
2408     case elfcpp::R_X86_64_PLT32:
2409     case elfcpp::R_X86_64_GOTPC32:
2410     case elfcpp::R_X86_64_GOT32:
2411       return 4;
2412
2413     case elfcpp::R_X86_64_16:
2414     case elfcpp::R_X86_64_PC16:
2415       return 2;
2416
2417     case elfcpp::R_X86_64_8:
2418     case elfcpp::R_X86_64_PC8:
2419       return 1;
2420
2421     case elfcpp::R_X86_64_COPY:
2422     case elfcpp::R_X86_64_GLOB_DAT:
2423     case elfcpp::R_X86_64_JUMP_SLOT:
2424     case elfcpp::R_X86_64_RELATIVE:
2425       // These are outstanding tls relocs, which are unexpected when linking
2426     case elfcpp::R_X86_64_TPOFF64:
2427     case elfcpp::R_X86_64_DTPMOD64:
2428     case elfcpp::R_X86_64_TLSDESC:
2429       object->error(_("unexpected reloc %u in object file"), r_type);
2430       return 0;
2431
2432     case elfcpp::R_X86_64_SIZE32:
2433     case elfcpp::R_X86_64_SIZE64:
2434     default:
2435       object->error(_("unsupported reloc %u against local symbol"), r_type);
2436       return 0;
2437     }
2438 }
2439
2440 // Scan the relocs during a relocatable link.
2441
2442 void
2443 Target_x86_64::scan_relocatable_relocs(const General_options& options,
2444                                        Symbol_table* symtab,
2445                                        Layout* layout,
2446                                        Sized_relobj<64, false>* object,
2447                                        unsigned int data_shndx,
2448                                        unsigned int sh_type,
2449                                        const unsigned char* prelocs,
2450                                        size_t reloc_count,
2451                                        Output_section* output_section,
2452                                        bool needs_special_offset_handling,
2453                                        size_t local_symbol_count,
2454                                        const unsigned char* plocal_symbols,
2455                                        Relocatable_relocs* rr)
2456 {
2457   gold_assert(sh_type == elfcpp::SHT_RELA);
2458
2459   typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_RELA,
2460     Relocatable_size_for_reloc> Scan_relocatable_relocs;
2461
2462   gold::scan_relocatable_relocs<64, false, elfcpp::SHT_RELA,
2463       Scan_relocatable_relocs>(
2464     options,
2465     symtab,
2466     layout,
2467     object,
2468     data_shndx,
2469     prelocs,
2470     reloc_count,
2471     output_section,
2472     needs_special_offset_handling,
2473     local_symbol_count,
2474     plocal_symbols,
2475     rr);
2476 }
2477
2478 // Relocate a section during a relocatable link.
2479
2480 void
2481 Target_x86_64::relocate_for_relocatable(
2482     const Relocate_info<64, false>* relinfo,
2483     unsigned int sh_type,
2484     const unsigned char* prelocs,
2485     size_t reloc_count,
2486     Output_section* output_section,
2487     off_t offset_in_output_section,
2488     const Relocatable_relocs* rr,
2489     unsigned char* view,
2490     elfcpp::Elf_types<64>::Elf_Addr view_address,
2491     section_size_type view_size,
2492     unsigned char* reloc_view,
2493     section_size_type reloc_view_size)
2494 {
2495   gold_assert(sh_type == elfcpp::SHT_RELA);
2496
2497   gold::relocate_for_relocatable<64, false, elfcpp::SHT_RELA>(
2498     relinfo,
2499     prelocs,
2500     reloc_count,
2501     output_section,
2502     offset_in_output_section,
2503     rr,
2504     view,
2505     view_address,
2506     view_size,
2507     reloc_view,
2508     reloc_view_size);
2509 }
2510
2511 // Return the value to use for a dynamic which requires special
2512 // treatment.  This is how we support equality comparisons of function
2513 // pointers across shared library boundaries, as described in the
2514 // processor specific ABI supplement.
2515
2516 uint64_t
2517 Target_x86_64::do_dynsym_value(const Symbol* gsym) const
2518 {
2519   gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
2520   return this->plt_section()->address() + gsym->plt_offset();
2521 }
2522
2523 // Return a string used to fill a code section with nops to take up
2524 // the specified length.
2525
2526 std::string
2527 Target_x86_64::do_code_fill(section_size_type length) const
2528 {
2529   if (length >= 16)
2530     {
2531       // Build a jmpq instruction to skip over the bytes.
2532       unsigned char jmp[5];
2533       jmp[0] = 0xe9;
2534       elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
2535       return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
2536               + std::string(length - 5, '\0'));
2537     }
2538
2539   // Nop sequences of various lengths.
2540   const char nop1[1] = { 0x90 };                   // nop
2541   const char nop2[2] = { 0x66, 0x90 };             // xchg %ax %ax
2542   const char nop3[3] = { 0x8d, 0x76, 0x00 };       // leal 0(%esi),%esi
2543   const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00};  // leal 0(%esi,1),%esi
2544   const char nop5[5] = { 0x90, 0x8d, 0x74, 0x26,   // nop
2545                          0x00 };                   // leal 0(%esi,1),%esi
2546   const char nop6[6] = { 0x8d, 0xb6, 0x00, 0x00,   // leal 0L(%esi),%esi
2547                          0x00, 0x00 };
2548   const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00,   // leal 0L(%esi,1),%esi
2549                          0x00, 0x00, 0x00 };
2550   const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26,   // nop
2551                          0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
2552   const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc,   // movl %esi,%esi
2553                          0x27, 0x00, 0x00, 0x00,   // leal 0L(%edi,1),%edi
2554                          0x00 };
2555   const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
2556                            0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
2557                            0x00, 0x00 };
2558   const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
2559                            0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
2560                            0x00, 0x00, 0x00 };
2561   const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2562                            0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
2563                            0x00, 0x00, 0x00, 0x00 };
2564   const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2565                            0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
2566                            0x27, 0x00, 0x00, 0x00,
2567                            0x00 };
2568   const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2569                            0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
2570                            0xbc, 0x27, 0x00, 0x00,
2571                            0x00, 0x00 };
2572   const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
2573                            0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
2574                            0x90, 0x90, 0x90, 0x90,
2575                            0x90, 0x90, 0x90 };
2576
2577   const char* nops[16] = {
2578     NULL,
2579     nop1, nop2, nop3, nop4, nop5, nop6, nop7,
2580     nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
2581   };
2582
2583   return std::string(nops[length], length);
2584 }
2585
2586 // The selector for x86_64 object files.
2587
2588 class Target_selector_x86_64 : public Target_selector
2589 {
2590 public:
2591   Target_selector_x86_64()
2592     : Target_selector(elfcpp::EM_X86_64, 64, false, "elf64-x86-64")
2593   { }
2594
2595   Target*
2596   do_instantiate_target()
2597   { return new Target_x86_64(); }
2598 };
2599
2600 Target_selector_x86_64 target_selector_x86_64;
2601
2602 } // End anonymous namespace.