contrib/binutils-2.20/gold/x86_64.cc

   1 // x86_64.cc -- x86_64 target support for gold.
   2
   3 // Copyright 2006, 2007, 2008, 2009 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 #include "freebsd.h"
  41 #include "gc.h"
  42
  43 namespace
  44 {
  45
  46 using namespace gold;
  47
  48 class Output_data_plt_x86_64;
  49
  50 // The x86_64 target class.
  51 // See the ABI at
  52 //   http://www.x86-64.org/documentation/abi.pdf
  53 // TLS info comes from
  54 //   http://people.redhat.com/drepper/tls.pdf
  55 //   http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
  56
  57 class Target_x86_64 : public Target_freebsd<64, false>
  58 {
  59  public:
  60   // In the x86_64 ABI (p 68), it says "The AMD64 ABI architectures
  61   // uses only Elf64_Rela relocation entries with explicit addends."
  62   typedef Output_data_reloc<elfcpp::SHT_RELA, true, 64, false> Reloc_section;
  63
  64   Target_x86_64()
  65     : Target_freebsd<64, false>(&x86_64_info),
  66       got_(NULL), plt_(NULL), got_plt_(NULL), rela_dyn_(NULL),
  67       copy_relocs_(elfcpp::R_X86_64_COPY), dynbss_(NULL),
  68       got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
  69   { }
  70
  71   // Hook for a new output section.
  72   void
  73   do_new_output_section(Output_section*) const;
  74
  75   // Scan the relocations to look for symbol adjustments.
  76   void
  77   gc_process_relocs(const General_options& options,
  78                     Symbol_table* symtab,
  79                     Layout* layout,
  80                     Sized_relobj<64, false>* object,
  81                     unsigned int data_shndx,
  82                     unsigned int sh_type,
  83                     const unsigned char* prelocs,
  84                     size_t reloc_count,
  85                     Output_section* output_section,
  86                     bool needs_special_offset_handling,
  87                     size_t local_symbol_count,
  88                     const unsigned char* plocal_symbols);
  89
  90   // Scan the relocations to look for symbol adjustments.
  91   void
  92   scan_relocs(const General_options& options,
  93               Symbol_table* symtab,
  94               Layout* layout,
  95               Sized_relobj<64, false>* object,
  96               unsigned int data_shndx,
  97               unsigned int sh_type,
  98               const unsigned char* prelocs,
  99               size_t reloc_count,
 100               Output_section* output_section,
 101               bool needs_special_offset_handling,
 102               size_t local_symbol_count,
 103               const unsigned char* plocal_symbols);
 104
 105   // Finalize the sections.
 106   void
 107   do_finalize_sections(Layout*);
 108
 109   // Return the value to use for a dynamic which requires special
 110   // treatment.
 111   uint64_t
 112   do_dynsym_value(const Symbol*) const;
 113
 114   // Relocate a section.
 115   void
 116   relocate_section(const Relocate_info<64, false>*,
 117                    unsigned int sh_type,
 118                    const unsigned char* prelocs,
 119                    size_t reloc_count,
 120                    Output_section* output_section,
 121                    bool needs_special_offset_handling,
 122                    unsigned char* view,
 123                    elfcpp::Elf_types<64>::Elf_Addr view_address,
 124                    section_size_type view_size,
 125                    const Reloc_symbol_changes*);
 126
 127   // Scan the relocs during a relocatable link.
 128   void
 129   scan_relocatable_relocs(const General_options& options,
 130                           Symbol_table* symtab,
 131                           Layout* layout,
 132                           Sized_relobj<64, false>* object,
 133                           unsigned int data_shndx,
 134                           unsigned int sh_type,
 135                           const unsigned char* prelocs,
 136                           size_t reloc_count,
 137                           Output_section* output_section,
 138                           bool needs_special_offset_handling,
 139                           size_t local_symbol_count,
 140                           const unsigned char* plocal_symbols,
 141                           Relocatable_relocs*);
 142
 143   // Relocate a section during a relocatable link.
 144   void
 145   relocate_for_relocatable(const Relocate_info<64, false>*,
 146                            unsigned int sh_type,
 147                            const unsigned char* prelocs,
 148                            size_t reloc_count,
 149                            Output_section* output_section,
 150                            off_t offset_in_output_section,
 151                            const Relocatable_relocs*,
 152                            unsigned char* view,
 153                            elfcpp::Elf_types<64>::Elf_Addr view_address,
 154                            section_size_type view_size,
 155                            unsigned char* reloc_view,
 156                            section_size_type reloc_view_size);
 157
 158   // Return a string used to fill a code section with nops.
 159   std::string
 160   do_code_fill(section_size_type length) const;
 161
 162   // Return whether SYM is defined by the ABI.
 163   bool
 164   do_is_defined_by_abi(const Symbol* sym) const
 165   { return strcmp(sym->name(), "__tls_get_addr") == 0; }
 166
 167   // Adjust -fstack-split code which calls non-stack-split code.
 168   void
 169   do_calls_non_split(Relobj* object, unsigned int shndx,
 170                      section_offset_type fnoffset, section_size_type fnsize,
 171                      unsigned char* view, section_size_type view_size,
 172                      std::string* from, std::string* to) const;
 173
 174   // Return the size of the GOT section.
 175   section_size_type
 176   got_size()
 177   {
 178     gold_assert(this->got_ != NULL);
 179     return this->got_->data_size();
 180   }
 181
 182  private:
 183   // The class which scans relocations.
 184   class Scan
 185   {
 186   public:
 187     Scan()
 188       : issued_non_pic_error_(false)
 189     { }
 190
 191     inline void
 192     local(const General_options& options, Symbol_table* symtab,
 193           Layout* layout, Target_x86_64* target,
 194           Sized_relobj<64, false>* object,
 195           unsigned int data_shndx,
 196           Output_section* output_section,
 197           const elfcpp::Rela<64, false>& reloc, unsigned int r_type,
 198           const elfcpp::Sym<64, false>& lsym);
 199
 200     inline void
 201     global(const General_options& options, Symbol_table* symtab,
 202            Layout* layout, Target_x86_64* target,
 203            Sized_relobj<64, false>* object,
 204            unsigned int data_shndx,
 205            Output_section* output_section,
 206            const elfcpp::Rela<64, false>& reloc, unsigned int r_type,
 207            Symbol* gsym);
 208
 209   private:
 210     static void
 211     unsupported_reloc_local(Sized_relobj<64, false>*, unsigned int r_type);
 212
 213     static void
 214     unsupported_reloc_global(Sized_relobj<64, false>*, unsigned int r_type,
 215                              Symbol*);
 216
 217     void
 218     check_non_pic(Relobj*, unsigned int r_type);
 219
 220     // Whether we have issued an error about a non-PIC compilation.
 221     bool issued_non_pic_error_;
 222   };
 223
 224   // The class which implements relocation.
 225   class Relocate
 226   {
 227    public:
 228     Relocate()
 229       : skip_call_tls_get_addr_(false), saw_tls_block_reloc_(false)
 230     { }
 231
 232     ~Relocate()
 233     {
 234       if (this->skip_call_tls_get_addr_)
 235         {
 236           // FIXME: This needs to specify the location somehow.
 237           gold_error(_("missing expected TLS relocation"));
 238         }
 239     }
 240
 241     // Do a relocation.  Return false if the caller should not issue
 242     // any warnings about this relocation.
 243     inline bool
 244     relocate(const Relocate_info<64, false>*, Target_x86_64*, Output_section*,
 245              size_t relnum, const elfcpp::Rela<64, false>&,
 246              unsigned int r_type, const Sized_symbol<64>*,
 247              const Symbol_value<64>*,
 248              unsigned char*, elfcpp::Elf_types<64>::Elf_Addr,
 249              section_size_type);
 250
 251    private:
 252     // Do a TLS relocation.
 253     inline void
 254     relocate_tls(const Relocate_info<64, false>*, Target_x86_64*,
 255                  size_t relnum, const elfcpp::Rela<64, false>&,
 256                  unsigned int r_type, const Sized_symbol<64>*,
 257                  const Symbol_value<64>*,
 258                  unsigned char*, elfcpp::Elf_types<64>::Elf_Addr,
 259                  section_size_type);
 260
 261     // Do a TLS General-Dynamic to Initial-Exec transition.
 262     inline void
 263     tls_gd_to_ie(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                  elfcpp::Elf_types<64>::Elf_Addr,
 269                  section_size_type view_size);
 270
 271     // Do a TLS General-Dynamic to Local-Exec transition.
 272     inline void
 273     tls_gd_to_le(const Relocate_info<64, false>*, size_t relnum,
 274                  Output_segment* tls_segment,
 275                  const elfcpp::Rela<64, false>&, unsigned int r_type,
 276                  elfcpp::Elf_types<64>::Elf_Addr value,
 277                  unsigned char* view,
 278                  section_size_type view_size);
 279
 280     // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
 281     inline void
 282     tls_desc_gd_to_ie(const Relocate_info<64, false>*, size_t relnum,
 283                       Output_segment* tls_segment,
 284                       const elfcpp::Rela<64, false>&, unsigned int r_type,
 285                       elfcpp::Elf_types<64>::Elf_Addr value,
 286                       unsigned char* view,
 287                       elfcpp::Elf_types<64>::Elf_Addr,
 288                       section_size_type view_size);
 289
 290     // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
 291     inline void
 292     tls_desc_gd_to_le(const Relocate_info<64, false>*, size_t relnum,
 293                       Output_segment* tls_segment,
 294                       const elfcpp::Rela<64, false>&, unsigned int r_type,
 295                       elfcpp::Elf_types<64>::Elf_Addr value,
 296                       unsigned char* view,
 297                       section_size_type view_size);
 298
 299     // Do a TLS Local-Dynamic to Local-Exec transition.
 300     inline void
 301     tls_ld_to_le(const Relocate_info<64, false>*, size_t relnum,
 302                  Output_segment* tls_segment,
 303                  const elfcpp::Rela<64, false>&, unsigned int r_type,
 304                  elfcpp::Elf_types<64>::Elf_Addr value,
 305                  unsigned char* view,
 306                  section_size_type view_size);
 307
 308     // Do a TLS Initial-Exec to Local-Exec transition.
 309     static inline void
 310     tls_ie_to_le(const Relocate_info<64, false>*, size_t relnum,
 311                  Output_segment* tls_segment,
 312                  const elfcpp::Rela<64, false>&, unsigned int r_type,
 313                  elfcpp::Elf_types<64>::Elf_Addr value,
 314                  unsigned char* view,
 315                  section_size_type view_size);
 316
 317     // This is set if we should skip the next reloc, which should be a
 318     // PLT32 reloc against ___tls_get_addr.
 319     bool skip_call_tls_get_addr_;
 320
 321     // This is set if we see a relocation which could load the address
 322     // of the TLS block.  Whether we see such a relocation determines
 323     // how we handle the R_X86_64_DTPOFF32 relocation, which is used
 324     // in debugging sections.
 325     bool saw_tls_block_reloc_;
 326   };
 327
 328   // A class which returns the size required for a relocation type,
 329   // used while scanning relocs during a relocatable link.
 330   class Relocatable_size_for_reloc
 331   {
 332    public:
 333     unsigned int
 334     get_size_for_reloc(unsigned int, Relobj*);
 335   };
 336
 337   // Adjust TLS relocation type based on the options and whether this
 338   // is a local symbol.
 339   static tls::Tls_optimization
 340   optimize_tls_reloc(bool is_final, int r_type);
 341
 342   // Get the GOT section, creating it if necessary.
 343   Output_data_got<64, false>*
 344   got_section(Symbol_table*, Layout*);
 345
 346   // Get the GOT PLT section.
 347   Output_data_space*
 348   got_plt_section() const
 349   {
 350     gold_assert(this->got_plt_ != NULL);
 351     return this->got_plt_;
 352   }
 353
 354   // Create the PLT section.
 355   void
 356   make_plt_section(Symbol_table* symtab, Layout* layout);
 357
 358   // Create a PLT entry for a global symbol.
 359   void
 360   make_plt_entry(Symbol_table*, Layout*, Symbol*);
 361
 362   // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
 363   void
 364   define_tls_base_symbol(Symbol_table*, Layout*);
 365
 366   // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
 367   void
 368   reserve_tlsdesc_entries(Symbol_table* symtab, Layout* layout);
 369
 370   // Create a GOT entry for the TLS module index.
 371   unsigned int
 372   got_mod_index_entry(Symbol_table* symtab, Layout* layout,
 373                       Sized_relobj<64, false>* object);
 374
 375   // Get the PLT section.
 376   Output_data_plt_x86_64*
 377   plt_section() const
 378   {
 379     gold_assert(this->plt_ != NULL);
 380     return this->plt_;
 381   }
 382
 383   // Get the dynamic reloc section, creating it if necessary.
 384   Reloc_section*
 385   rela_dyn_section(Layout*);
 386
 387   // Add a potential copy relocation.
 388   void
 389   copy_reloc(Symbol_table* symtab, Layout* layout,
 390              Sized_relobj<64, false>* object,
 391              unsigned int shndx, Output_section* output_section,
 392              Symbol* sym, const elfcpp::Rela<64, false>& reloc)
 393   {
 394     this->copy_relocs_.copy_reloc(symtab, layout,
 395                                   symtab->get_sized_symbol<64>(sym),
 396                                   object, shndx, output_section,
 397                                   reloc, this->rela_dyn_section(layout));
 398   }
 399
 400   // Information about this specific target which we pass to the
 401   // general Target structure.
 402   static const Target::Target_info x86_64_info;
 403
 404   enum Got_type
 405   {
 406     GOT_TYPE_STANDARD = 0,      // GOT entry for a regular symbol
 407     GOT_TYPE_TLS_OFFSET = 1,    // GOT entry for TLS offset
 408     GOT_TYPE_TLS_PAIR = 2,      // GOT entry for TLS module/offset pair
 409     GOT_TYPE_TLS_DESC = 3       // GOT entry for TLS_DESC pair
 410   };
 411
 412   // The GOT section.
 413   Output_data_got<64, false>* got_;
 414   // The PLT section.
 415   Output_data_plt_x86_64* plt_;
 416   // The GOT PLT section.
 417   Output_data_space* got_plt_;
 418   // The dynamic reloc section.
 419   Reloc_section* rela_dyn_;
 420   // Relocs saved to avoid a COPY reloc.
 421   Copy_relocs<elfcpp::SHT_RELA, 64, false> copy_relocs_;
 422   // Space for variables copied with a COPY reloc.
 423   Output_data_space* dynbss_;
 424   // Offset of the GOT entry for the TLS module index.
 425   unsigned int got_mod_index_offset_;
 426   // True if the _TLS_MODULE_BASE_ symbol has been defined.
 427   bool tls_base_symbol_defined_;
 428 };
 429
 430 const Target::Target_info Target_x86_64::x86_64_info =
 431 {
 432   64,                   // size
 433   false,                // is_big_endian
 434   elfcpp::EM_X86_64,    // machine_code
 435   false,                // has_make_symbol
 436   false,                // has_resolve
 437   true,                 // has_code_fill
 438   true,                 // is_default_stack_executable
 439   '\0',                 // wrap_char
 440   "/lib/ld64.so.1",     // program interpreter
 441   0x400000,             // default_text_segment_address
 442   0x1000,               // abi_pagesize (overridable by -z max-page-size)
 443   0x1000,               // common_pagesize (overridable by -z common-page-size)
 444   elfcpp::SHN_UNDEF,    // small_common_shndx
 445   elfcpp::SHN_X86_64_LCOMMON,   // large_common_shndx
 446   0,                    // small_common_section_flags
 447   elfcpp::SHF_X86_64_LARGE      // large_common_section_flags
 448 };
 449
 450 // This is called when a new output section is created.  This is where
 451 // we handle the SHF_X86_64_LARGE.
 452
 453 void
 454 Target_x86_64::do_new_output_section(Output_section *os) const
 455 {
 456   if ((os->flags() & elfcpp::SHF_X86_64_LARGE) != 0)
 457     os->set_is_large_section();
 458 }
 459
 460 // Get the GOT section, creating it if necessary.
 461
 462 Output_data_got<64, false>*
 463 Target_x86_64::got_section(Symbol_table* symtab, Layout* layout)
 464 {
 465   if (this->got_ == NULL)
 466     {
 467       gold_assert(symtab != NULL && layout != NULL);
 468
 469       this->got_ = new Output_data_got<64, false>();
 470
 471       Output_section* os;
 472       os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
 473                                            (elfcpp::SHF_ALLOC
 474                                             | elfcpp::SHF_WRITE),
 475                                            this->got_);
 476       os->set_is_relro();
 477
 478       // The old GNU linker creates a .got.plt section.  We just
 479       // create another set of data in the .got section.  Note that we
 480       // always create a PLT if we create a GOT, although the PLT
 481       // might be empty.
 482       this->got_plt_ = new Output_data_space(8, "** GOT PLT");
 483       os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
 484                                            (elfcpp::SHF_ALLOC
 485                                             | elfcpp::SHF_WRITE),
 486                                            this->got_plt_);
 487       os->set_is_relro();
 488
 489       // The first three entries are reserved.
 490       this->got_plt_->set_current_data_size(3 * 8);
 491
 492       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
 493       symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
 494                                     this->got_plt_,
 495                                     0, 0, elfcpp::STT_OBJECT,
 496                                     elfcpp::STB_LOCAL,
 497                                     elfcpp::STV_HIDDEN, 0,
 498                                     false, false);
 499     }
 500
 501   return this->got_;
 502 }
 503
 504 // Get the dynamic reloc section, creating it if necessary.
 505
 506 Target_x86_64::Reloc_section*
 507 Target_x86_64::rela_dyn_section(Layout* layout)
 508 {
 509   if (this->rela_dyn_ == NULL)
 510     {
 511       gold_assert(layout != NULL);
 512       this->rela_dyn_ = new Reloc_section(parameters->options().combreloc());
 513       layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
 514                                       elfcpp::SHF_ALLOC, this->rela_dyn_);
 515     }
 516   return this->rela_dyn_;
 517 }
 518
 519 // A class to handle the PLT data.
 520
 521 class Output_data_plt_x86_64 : public Output_section_data
 522 {
 523  public:
 524   typedef Output_data_reloc<elfcpp::SHT_RELA, true, 64, false> Reloc_section;
 525
 526   Output_data_plt_x86_64(Layout*, Output_data_got<64, false>*,
 527                          Output_data_space*);
 528
 529   // Add an entry to the PLT.
 530   void
 531   add_entry(Symbol* gsym);
 532
 533   // Add the reserved TLSDESC_PLT entry to the PLT.
 534   void
 535   reserve_tlsdesc_entry(unsigned int got_offset)
 536   { this->tlsdesc_got_offset_ = got_offset; }
 537
 538   // Return true if a TLSDESC_PLT entry has been reserved.
 539   bool
 540   has_tlsdesc_entry() const
 541   { return this->tlsdesc_got_offset_ != -1U; }
 542
 543   // Return the GOT offset for the reserved TLSDESC_PLT entry.
 544   unsigned int
 545   get_tlsdesc_got_offset() const
 546   { return this->tlsdesc_got_offset_; }
 547
 548   // Return the offset of the reserved TLSDESC_PLT entry.
 549   unsigned int
 550   get_tlsdesc_plt_offset() const
 551   { return (this->count_ + 1) * plt_entry_size; }
 552
 553   // Return the .rel.plt section data.
 554   const Reloc_section*
 555   rel_plt() const
 556   { return this->rel_; }
 557
 558  protected:
 559   void
 560   do_adjust_output_section(Output_section* os);
 561
 562   // Write to a map file.
 563   void
 564   do_print_to_mapfile(Mapfile* mapfile) const
 565   { mapfile->print_output_data(this, _("** PLT")); }
 566
 567  private:
 568   // The size of an entry in the PLT.
 569   static const int plt_entry_size = 16;
 570
 571   // The first entry in the PLT.
 572   // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
 573   // procedure linkage table for both programs and shared objects."
 574   static unsigned char first_plt_entry[plt_entry_size];
 575
 576   // Other entries in the PLT for an executable.
 577   static unsigned char plt_entry[plt_entry_size];
 578
 579   // The reserved TLSDESC entry in the PLT for an executable.
 580   static unsigned char tlsdesc_plt_entry[plt_entry_size];
 581
 582   // Set the final size.
 583   void
 584   set_final_data_size();
 585
 586   // Write out the PLT data.
 587   void
 588   do_write(Output_file*);
 589
 590   // The reloc section.
 591   Reloc_section* rel_;
 592   // The .got section.
 593   Output_data_got<64, false>* got_;
 594   // The .got.plt section.
 595   Output_data_space* got_plt_;
 596   // The number of PLT entries.
 597   unsigned int count_;
 598   // Offset of the reserved TLSDESC_GOT entry when needed.
 599   unsigned int tlsdesc_got_offset_;
 600 };
 601
 602 // Create the PLT section.  The ordinary .got section is an argument,
 603 // since we need to refer to the start.  We also create our own .got
 604 // section just for PLT entries.
 605
 606 Output_data_plt_x86_64::Output_data_plt_x86_64(Layout* layout,
 607                                                Output_data_got<64, false>* got,
 608                                                Output_data_space* got_plt)
 609   : Output_section_data(8), got_(got), got_plt_(got_plt), count_(0),
 610     tlsdesc_got_offset_(-1U)
 611 {
 612   this->rel_ = new Reloc_section(false);
 613   layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
 614                                   elfcpp::SHF_ALLOC, this->rel_);
 615 }
 616
 617 void
 618 Output_data_plt_x86_64::do_adjust_output_section(Output_section* os)
 619 {
 620   os->set_entsize(plt_entry_size);
 621 }
 622
 623 // Add an entry to the PLT.
 624
 625 void
 626 Output_data_plt_x86_64::add_entry(Symbol* gsym)
 627 {
 628   gold_assert(!gsym->has_plt_offset());
 629
 630   // Note that when setting the PLT offset we skip the initial
 631   // reserved PLT entry.
 632   gsym->set_plt_offset((this->count_ + 1) * plt_entry_size);
 633
 634   ++this->count_;
 635
 636   section_offset_type got_offset = this->got_plt_->current_data_size();
 637
 638   // Every PLT entry needs a GOT entry which points back to the PLT
 639   // entry (this will be changed by the dynamic linker, normally
 640   // lazily when the function is called).
 641   this->got_plt_->set_current_data_size(got_offset + 8);
 642
 643   // Every PLT entry needs a reloc.
 644   gsym->set_needs_dynsym_entry();
 645   this->rel_->add_global(gsym, elfcpp::R_X86_64_JUMP_SLOT, this->got_plt_,
 646                          got_offset, 0);
 647
 648   // Note that we don't need to save the symbol.  The contents of the
 649   // PLT are independent of which symbols are used.  The symbols only
 650   // appear in the relocations.
 651 }
 652
 653 // Set the final size.
 654 void
 655 Output_data_plt_x86_64::set_final_data_size()
 656 {
 657   unsigned int count = this->count_;
 658   if (this->has_tlsdesc_entry())
 659     ++count;
 660   this->set_data_size((count + 1) * plt_entry_size);
 661 }
 662
 663 // The first entry in the PLT for an executable.
 664
 665 unsigned char Output_data_plt_x86_64::first_plt_entry[plt_entry_size] =
 666 {
 667   // From AMD64 ABI Draft 0.98, page 76
 668   0xff, 0x35,   // pushq contents of memory address
 669   0, 0, 0, 0,   // replaced with address of .got + 8
 670   0xff, 0x25,   // jmp indirect
 671   0, 0, 0, 0,   // replaced with address of .got + 16
 672   0x90, 0x90, 0x90, 0x90   // noop (x4)
 673 };
 674
 675 // Subsequent entries in the PLT for an executable.
 676
 677 unsigned char Output_data_plt_x86_64::plt_entry[plt_entry_size] =
 678 {
 679   // From AMD64 ABI Draft 0.98, page 76
 680   0xff, 0x25,   // jmpq indirect
 681   0, 0, 0, 0,   // replaced with address of symbol in .got
 682   0x68,         // pushq immediate
 683   0, 0, 0, 0,   // replaced with offset into relocation table
 684   0xe9,         // jmpq relative
 685   0, 0, 0, 0    // replaced with offset to start of .plt
 686 };
 687
 688 // The reserved TLSDESC entry in the PLT for an executable.
 689
 690 unsigned char Output_data_plt_x86_64::tlsdesc_plt_entry[plt_entry_size] =
 691 {
 692   // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
 693   // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
 694   0xff, 0x35,   // pushq x(%rip)
 695   0, 0, 0, 0,   // replaced with address of linkmap GOT entry (at PLTGOT + 8)
 696   0xff, 0x25,   // jmpq *y(%rip)
 697   0, 0, 0, 0,   // replaced with offset of reserved TLSDESC_GOT entry
 698   0x0f, 0x1f,   // nop
 699   0x40, 0
 700 };
 701
 702 // Write out the PLT.  This uses the hand-coded instructions above,
 703 // and adjusts them as needed.  This is specified by the AMD64 ABI.
 704
 705 void
 706 Output_data_plt_x86_64::do_write(Output_file* of)
 707 {
 708   const off_t offset = this->offset();
 709   const section_size_type oview_size =
 710     convert_to_section_size_type(this->data_size());
 711   unsigned char* const oview = of->get_output_view(offset, oview_size);
 712
 713   const off_t got_file_offset = this->got_plt_->offset();
 714   const section_size_type got_size =
 715     convert_to_section_size_type(this->got_plt_->data_size());
 716   unsigned char* const got_view = of->get_output_view(got_file_offset,
 717                                                       got_size);
 718
 719   unsigned char* pov = oview;
 720
 721   // The base address of the .plt section.
 722   elfcpp::Elf_types<64>::Elf_Addr plt_address = this->address();
 723   // The base address of the .got section.
 724   elfcpp::Elf_types<64>::Elf_Addr got_base = this->got_->address();
 725   // The base address of the PLT portion of the .got section,
 726   // which is where the GOT pointer will point, and where the
 727   // three reserved GOT entries are located.
 728   elfcpp::Elf_types<64>::Elf_Addr got_address = this->got_plt_->address();
 729
 730   memcpy(pov, first_plt_entry, plt_entry_size);
 731   // We do a jmp relative to the PC at the end of this instruction.
 732   elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
 733                                               (got_address + 8
 734                                                - (plt_address + 6)));
 735   elfcpp::Swap<32, false>::writeval(pov + 8,
 736                                     (got_address + 16
 737                                      - (plt_address + 12)));
 738   pov += plt_entry_size;
 739
 740   unsigned char* got_pov = got_view;
 741
 742   memset(got_pov, 0, 24);
 743   got_pov += 24;
 744
 745   unsigned int plt_offset = plt_entry_size;
 746   unsigned int got_offset = 24;
 747   const unsigned int count = this->count_;
 748   for (unsigned int plt_index = 0;
 749        plt_index < count;
 750        ++plt_index,
 751          pov += plt_entry_size,
 752          got_pov += 8,
 753          plt_offset += plt_entry_size,
 754          got_offset += 8)
 755     {
 756       // Set and adjust the PLT entry itself.
 757       memcpy(pov, plt_entry, plt_entry_size);
 758       elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
 759                                                   (got_address + got_offset
 760                                                    - (plt_address + plt_offset
 761                                                       + 6)));
 762
 763       elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_index);
 764       elfcpp::Swap<32, false>::writeval(pov + 12,
 765                                         - (plt_offset + plt_entry_size));
 766
 767       // Set the entry in the GOT.
 768       elfcpp::Swap<64, false>::writeval(got_pov, plt_address + plt_offset + 6);
 769     }
 770
 771   if (this->has_tlsdesc_entry())
 772     {
 773       // Set and adjust the reserved TLSDESC PLT entry.
 774       unsigned int tlsdesc_got_offset = this->get_tlsdesc_got_offset();
 775       memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
 776       elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
 777                                                   (got_address + 8
 778                                                    - (plt_address + plt_offset
 779                                                       + 6)));
 780       elfcpp::Swap_unaligned<32, false>::writeval(pov + 8,
 781                                                   (got_base
 782                                                    + tlsdesc_got_offset
 783                                                    - (plt_address + plt_offset
 784                                                       + 12)));
 785       pov += plt_entry_size;
 786     }
 787
 788   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
 789   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
 790
 791   of->write_output_view(offset, oview_size, oview);
 792   of->write_output_view(got_file_offset, got_size, got_view);
 793 }
 794
 795 // Create the PLT section.
 796
 797 void
 798 Target_x86_64::make_plt_section(Symbol_table* symtab, Layout* layout)
 799 {
 800   if (this->plt_ == NULL)
 801     {
 802       // Create the GOT sections first.
 803       this->got_section(symtab, layout);
 804
 805       this->plt_ = new Output_data_plt_x86_64(layout, this->got_,
 806                                               this->got_plt_);
 807       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
 808                                       (elfcpp::SHF_ALLOC
 809                                        | elfcpp::SHF_EXECINSTR),
 810                                       this->plt_);
 811     }
 812 }
 813
 814 // Create a PLT entry for a global symbol.
 815
 816 void
 817 Target_x86_64::make_plt_entry(Symbol_table* symtab, Layout* layout,
 818                               Symbol* gsym)
 819 {
 820   if (gsym->has_plt_offset())
 821     return;
 822
 823   if (this->plt_ == NULL)
 824     this->make_plt_section(symtab, layout);
 825
 826   this->plt_->add_entry(gsym);
 827 }
 828
 829 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
 830
 831 void
 832 Target_x86_64::define_tls_base_symbol(Symbol_table* symtab, Layout* layout)
 833 {
 834   if (this->tls_base_symbol_defined_)
 835     return;
 836
 837   Output_segment* tls_segment = layout->tls_segment();
 838   if (tls_segment != NULL)
 839     {
 840       bool is_exec = parameters->options().output_is_executable();
 841       symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
 842                                        tls_segment, 0, 0,
 843                                        elfcpp::STT_TLS,
 844                                        elfcpp::STB_LOCAL,
 845                                        elfcpp::STV_HIDDEN, 0,
 846                                        (is_exec
 847                                         ? Symbol::SEGMENT_END
 848                                         : Symbol::SEGMENT_START),
 849                                        true);
 850     }
 851   this->tls_base_symbol_defined_ = true;
 852 }
 853
 854 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
 855
 856 void
 857 Target_x86_64::reserve_tlsdesc_entries(Symbol_table* symtab,
 858                                              Layout* layout)
 859 {
 860   if (this->plt_ == NULL)
 861     this->make_plt_section(symtab, layout);
 862
 863   if (!this->plt_->has_tlsdesc_entry())
 864     {
 865       // Allocate the TLSDESC_GOT entry.
 866       Output_data_got<64, false>* got = this->got_section(symtab, layout);
 867       unsigned int got_offset = got->add_constant(0);
 868
 869       // Allocate the TLSDESC_PLT entry.
 870       this->plt_->reserve_tlsdesc_entry(got_offset);
 871     }
 872 }
 873
 874 // Create a GOT entry for the TLS module index.
 875
 876 unsigned int
 877 Target_x86_64::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
 878                                    Sized_relobj<64, false>* object)
 879 {
 880   if (this->got_mod_index_offset_ == -1U)
 881     {
 882       gold_assert(symtab != NULL && layout != NULL && object != NULL);
 883       Reloc_section* rela_dyn = this->rela_dyn_section(layout);
 884       Output_data_got<64, false>* got = this->got_section(symtab, layout);
 885       unsigned int got_offset = got->add_constant(0);
 886       rela_dyn->add_local(object, 0, elfcpp::R_X86_64_DTPMOD64, got,
 887                           got_offset, 0);
 888       got->add_constant(0);
 889       this->got_mod_index_offset_ = got_offset;
 890     }
 891   return this->got_mod_index_offset_;
 892 }
 893
 894 // Optimize the TLS relocation type based on what we know about the
 895 // symbol.  IS_FINAL is true if the final address of this symbol is
 896 // known at link time.
 897
 898 tls::Tls_optimization
 899 Target_x86_64::optimize_tls_reloc(bool is_final, int r_type)
 900 {
 901   // If we are generating a shared library, then we can't do anything
 902   // in the linker.
 903   if (parameters->options().shared())
 904     return tls::TLSOPT_NONE;
 905
 906   switch (r_type)
 907     {
 908     case elfcpp::R_X86_64_TLSGD:
 909     case elfcpp::R_X86_64_GOTPC32_TLSDESC:
 910     case elfcpp::R_X86_64_TLSDESC_CALL:
 911       // These are General-Dynamic which permits fully general TLS
 912       // access.  Since we know that we are generating an executable,
 913       // we can convert this to Initial-Exec.  If we also know that
 914       // this is a local symbol, we can further switch to Local-Exec.
 915       if (is_final)
 916         return tls::TLSOPT_TO_LE;
 917       return tls::TLSOPT_TO_IE;
 918
 919     case elfcpp::R_X86_64_TLSLD:
 920       // This is Local-Dynamic, which refers to a local symbol in the
 921       // dynamic TLS block.  Since we know that we generating an
 922       // executable, we can switch to Local-Exec.
 923       return tls::TLSOPT_TO_LE;
 924
 925     case elfcpp::R_X86_64_DTPOFF32:
 926     case elfcpp::R_X86_64_DTPOFF64:
 927       // Another Local-Dynamic reloc.
 928       return tls::TLSOPT_TO_LE;
 929
 930     case elfcpp::R_X86_64_GOTTPOFF:
 931       // These are Initial-Exec relocs which get the thread offset
 932       // from the GOT.  If we know that we are linking against the
 933       // local symbol, we can switch to Local-Exec, which links the
 934       // thread offset into the instruction.
 935       if (is_final)
 936         return tls::TLSOPT_TO_LE;
 937       return tls::TLSOPT_NONE;
 938
 939     case elfcpp::R_X86_64_TPOFF32:
 940       // When we already have Local-Exec, there is nothing further we
 941       // can do.
 942       return tls::TLSOPT_NONE;
 943
 944     default:
 945       gold_unreachable();
 946     }
 947 }
 948
 949 // Report an unsupported relocation against a local symbol.
 950
 951 void
 952 Target_x86_64::Scan::unsupported_reloc_local(Sized_relobj<64, false>* object,
 953                                              unsigned int r_type)
 954 {
 955   gold_error(_("%s: unsupported reloc %u against local symbol"),
 956              object->name().c_str(), r_type);
 957 }
 958
 959 // We are about to emit a dynamic relocation of type R_TYPE.  If the
 960 // dynamic linker does not support it, issue an error.  The GNU linker
 961 // only issues a non-PIC error for an allocated read-only section.
 962 // Here we know the section is allocated, but we don't know that it is
 963 // read-only.  But we check for all the relocation types which the
 964 // glibc dynamic linker supports, so it seems appropriate to issue an
 965 // error even if the section is not read-only.
 966
 967 void
 968 Target_x86_64::Scan::check_non_pic(Relobj* object, unsigned int r_type)
 969 {
 970   switch (r_type)
 971     {
 972       // These are the relocation types supported by glibc for x86_64.
 973     case elfcpp::R_X86_64_RELATIVE:
 974     case elfcpp::R_X86_64_GLOB_DAT:
 975     case elfcpp::R_X86_64_JUMP_SLOT:
 976     case elfcpp::R_X86_64_DTPMOD64:
 977     case elfcpp::R_X86_64_DTPOFF64:
 978     case elfcpp::R_X86_64_TPOFF64:
 979     case elfcpp::R_X86_64_64:
 980     case elfcpp::R_X86_64_32:
 981     case elfcpp::R_X86_64_PC32:
 982     case elfcpp::R_X86_64_COPY:
 983       return;
 984
 985     default:
 986       // This prevents us from issuing more than one error per reloc
 987       // section.  But we can still wind up issuing more than one
 988       // error per object file.
 989       if (this->issued_non_pic_error_)
 990         return;
 991       gold_assert(parameters->options().output_is_position_independent());
 992       object->error(_("requires unsupported dynamic reloc; "
 993                       "recompile with -fPIC"));
 994       this->issued_non_pic_error_ = true;
 995       return;
 996
 997     case elfcpp::R_X86_64_NONE:
 998       gold_unreachable();
 999     }
1000 }
1001
1002 // Scan a relocation for a local symbol.
1003
1004 inline void
1005 Target_x86_64::Scan::local(const General_options&,
1006                            Symbol_table* symtab,
1007                            Layout* layout,
1008                            Target_x86_64* target,
1009                            Sized_relobj<64, false>* object,
1010                            unsigned int data_shndx,
1011                            Output_section* output_section,
1012                            const elfcpp::Rela<64, false>& reloc,
1013                            unsigned int r_type,
1014                            const elfcpp::Sym<64, false>& lsym)
1015 {
1016   switch (r_type)
1017     {
1018     case elfcpp::R_X86_64_NONE:
1019     case elfcpp::R_386_GNU_VTINHERIT:
1020     case elfcpp::R_386_GNU_VTENTRY:
1021       break;
1022
1023     case elfcpp::R_X86_64_64:
1024       // If building a shared library (or a position-independent
1025       // executable), we need to create a dynamic relocation for this
1026       // location.  The relocation applied at link time will apply the
1027       // link-time value, so we flag the location with an
1028       // R_X86_64_RELATIVE relocation so the dynamic loader can
1029       // relocate it easily.
1030       if (parameters->options().output_is_position_independent())
1031         {
1032           unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
1033           Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1034           rela_dyn->add_local_relative(object, r_sym,
1035                                        elfcpp::R_X86_64_RELATIVE,
1036                                        output_section, data_shndx,
1037                                        reloc.get_r_offset(),
1038                                        reloc.get_r_addend());
1039         }
1040       break;
1041
1042     case elfcpp::R_X86_64_32:
1043     case elfcpp::R_X86_64_32S:
1044     case elfcpp::R_X86_64_16:
1045     case elfcpp::R_X86_64_8:
1046       // If building a shared library (or a position-independent
1047       // executable), we need to create a dynamic relocation for this
1048       // location.  We can't use an R_X86_64_RELATIVE relocation
1049       // because that is always a 64-bit relocation.
1050       if (parameters->options().output_is_position_independent())
1051         {
1052           this->check_non_pic(object, r_type);
1053
1054           Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1055           unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
1056           if (lsym.get_st_type() != elfcpp::STT_SECTION)
1057             rela_dyn->add_local(object, r_sym, r_type, output_section,
1058                                 data_shndx, reloc.get_r_offset(),
1059                                 reloc.get_r_addend());
1060           else
1061             {
1062               gold_assert(lsym.get_st_value() == 0);
1063               unsigned int shndx = lsym.get_st_shndx();
1064               bool is_ordinary;
1065               shndx = object->adjust_sym_shndx(r_sym, shndx,
1066                                                &is_ordinary);
1067               if (!is_ordinary)
1068                 object->error(_("section symbol %u has bad shndx %u"),
1069                               r_sym, shndx);
1070               else
1071                 rela_dyn->add_local_section(object, shndx,
1072                                             r_type, output_section,
1073                                             data_shndx, reloc.get_r_offset(),
1074                                             reloc.get_r_addend());
1075             }
1076         }
1077       break;
1078
1079     case elfcpp::R_X86_64_PC64:
1080     case elfcpp::R_X86_64_PC32:
1081     case elfcpp::R_X86_64_PC16:
1082     case elfcpp::R_X86_64_PC8:
1083       break;
1084
1085     case elfcpp::R_X86_64_PLT32:
1086       // Since we know this is a local symbol, we can handle this as a
1087       // PC32 reloc.
1088       break;
1089
1090     case elfcpp::R_X86_64_GOTPC32:
1091     case elfcpp::R_X86_64_GOTOFF64:
1092     case elfcpp::R_X86_64_GOTPC64:
1093     case elfcpp::R_X86_64_PLTOFF64:
1094       // We need a GOT section.
1095       target->got_section(symtab, layout);
1096       // For PLTOFF64, we'd normally want a PLT section, but since we
1097       // know this is a local symbol, no PLT is needed.
1098       break;
1099
1100     case elfcpp::R_X86_64_GOT64:
1101     case elfcpp::R_X86_64_GOT32:
1102     case elfcpp::R_X86_64_GOTPCREL64:
1103     case elfcpp::R_X86_64_GOTPCREL:
1104     case elfcpp::R_X86_64_GOTPLT64:
1105       {
1106         // The symbol requires a GOT entry.
1107         Output_data_got<64, false>* got = target->got_section(symtab, layout);
1108         unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
1109         if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
1110           {
1111             // If we are generating a shared object, we need to add a
1112             // dynamic relocation for this symbol's GOT entry.
1113             if (parameters->options().output_is_position_independent())
1114               {
1115                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1116                 // R_X86_64_RELATIVE assumes a 64-bit relocation.
1117                 if (r_type != elfcpp::R_X86_64_GOT32)
1118                   rela_dyn->add_local_relative(
1119                       object, r_sym, elfcpp::R_X86_64_RELATIVE, got,
1120                       object->local_got_offset(r_sym, GOT_TYPE_STANDARD), 0);
1121                 else
1122                   {
1123                     this->check_non_pic(object, r_type);
1124
1125                     gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
1126                     rela_dyn->add_local(
1127                         object, r_sym, r_type, got,
1128                         object->local_got_offset(r_sym, GOT_TYPE_STANDARD), 0);
1129                   }
1130               }
1131           }
1132         // For GOTPLT64, we'd normally want a PLT section, but since
1133         // we know this is a local symbol, no PLT is needed.
1134       }
1135       break;
1136
1137     case elfcpp::R_X86_64_COPY:
1138     case elfcpp::R_X86_64_GLOB_DAT:
1139     case elfcpp::R_X86_64_JUMP_SLOT:
1140     case elfcpp::R_X86_64_RELATIVE:
1141       // These are outstanding tls relocs, which are unexpected when linking
1142     case elfcpp::R_X86_64_TPOFF64:
1143     case elfcpp::R_X86_64_DTPMOD64:
1144     case elfcpp::R_X86_64_TLSDESC:
1145       gold_error(_("%s: unexpected reloc %u in object file"),
1146                  object->name().c_str(), r_type);
1147       break;
1148
1149       // These are initial tls relocs, which are expected when linking
1150     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
1151     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
1152     case elfcpp::R_X86_64_TLSDESC_CALL:
1153     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
1154     case elfcpp::R_X86_64_DTPOFF32:
1155     case elfcpp::R_X86_64_DTPOFF64:
1156     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
1157     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
1158       {
1159         bool output_is_shared = parameters->options().shared();
1160         const tls::Tls_optimization optimized_type
1161             = Target_x86_64::optimize_tls_reloc(!output_is_shared, r_type);
1162         switch (r_type)
1163           {
1164           case elfcpp::R_X86_64_TLSGD:       // General-dynamic
1165             if (optimized_type == tls::TLSOPT_NONE)
1166               {
1167                 // Create a pair of GOT entries for the module index and
1168                 // dtv-relative offset.
1169                 Output_data_got<64, false>* got
1170                     = target->got_section(symtab, layout);
1171                 unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
1172                 unsigned int shndx = lsym.get_st_shndx();
1173                 bool is_ordinary;
1174                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1175                 if (!is_ordinary)
1176                   object->error(_("local symbol %u has bad shndx %u"),
1177                               r_sym, shndx);
1178                 else
1179                   got->add_local_pair_with_rela(object, r_sym,
1180                                                 shndx,
1181                                                 GOT_TYPE_TLS_PAIR,
1182                                                 target->rela_dyn_section(layout),
1183                                                 elfcpp::R_X86_64_DTPMOD64, 0);
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_GOTPC32_TLSDESC:
1190             target->define_tls_base_symbol(symtab, layout);
1191             if (optimized_type == tls::TLSOPT_NONE)
1192               {
1193                 // Create reserved PLT and GOT entries for the resolver.
1194                 target->reserve_tlsdesc_entries(symtab, layout);
1195
1196                 // Generate a double GOT entry with an R_X86_64_TLSDESC reloc.
1197                 Output_data_got<64, false>* got
1198                     = target->got_section(symtab, layout);
1199                 unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
1200                 unsigned int shndx = lsym.get_st_shndx();
1201                 bool is_ordinary;
1202                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1203                 if (!is_ordinary)
1204                   object->error(_("local symbol %u has bad shndx %u"),
1205                               r_sym, shndx);
1206                 else
1207                   got->add_local_pair_with_rela(object, r_sym,
1208                                                 shndx,
1209                                                 GOT_TYPE_TLS_DESC,
1210                                                 target->rela_dyn_section(layout),
1211                                                 elfcpp::R_X86_64_TLSDESC, 0);
1212               }
1213             else if (optimized_type != tls::TLSOPT_TO_LE)
1214               unsupported_reloc_local(object, r_type);
1215             break;
1216
1217           case elfcpp::R_X86_64_TLSDESC_CALL:
1218             break;
1219
1220           case elfcpp::R_X86_64_TLSLD:       // Local-dynamic
1221             if (optimized_type == tls::TLSOPT_NONE)
1222               {
1223                 // Create a GOT entry for the module index.
1224                 target->got_mod_index_entry(symtab, layout, object);
1225               }
1226             else if (optimized_type != tls::TLSOPT_TO_LE)
1227               unsupported_reloc_local(object, r_type);
1228             break;
1229
1230           case elfcpp::R_X86_64_DTPOFF32:
1231           case elfcpp::R_X86_64_DTPOFF64:
1232             break;
1233
1234           case elfcpp::R_X86_64_GOTTPOFF:    // Initial-exec
1235             layout->set_has_static_tls();
1236             if (optimized_type == tls::TLSOPT_NONE)
1237               {
1238                 // Create a GOT entry for the tp-relative offset.
1239                 Output_data_got<64, false>* got
1240                     = target->got_section(symtab, layout);
1241                 unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
1242                 got->add_local_with_rela(object, r_sym, GOT_TYPE_TLS_OFFSET,
1243                                          target->rela_dyn_section(layout),
1244                                          elfcpp::R_X86_64_TPOFF64);
1245               }
1246             else if (optimized_type != tls::TLSOPT_TO_LE)
1247               unsupported_reloc_local(object, r_type);
1248             break;
1249
1250           case elfcpp::R_X86_64_TPOFF32:     // Local-exec
1251             layout->set_has_static_tls();
1252             if (output_is_shared)
1253               unsupported_reloc_local(object, r_type);
1254             break;
1255
1256           default:
1257             gold_unreachable();
1258           }
1259       }
1260       break;
1261
1262     case elfcpp::R_X86_64_SIZE32:
1263     case elfcpp::R_X86_64_SIZE64:
1264     default:
1265       gold_error(_("%s: unsupported reloc %u against local symbol"),
1266                  object->name().c_str(), r_type);
1267       break;
1268     }
1269 }
1270
1271
1272 // Report an unsupported relocation against a global symbol.
1273
1274 void
1275 Target_x86_64::Scan::unsupported_reloc_global(Sized_relobj<64, false>* object,
1276                                               unsigned int r_type,
1277                                               Symbol* gsym)
1278 {
1279   gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1280              object->name().c_str(), r_type, gsym->demangled_name().c_str());
1281 }
1282
1283 // Scan a relocation for a global symbol.
1284
1285 inline void
1286 Target_x86_64::Scan::global(const General_options&,
1287                             Symbol_table* symtab,
1288                             Layout* layout,
1289                             Target_x86_64* target,
1290                             Sized_relobj<64, false>* object,
1291                             unsigned int data_shndx,
1292                             Output_section* output_section,
1293                             const elfcpp::Rela<64, false>& reloc,
1294                             unsigned int r_type,
1295                             Symbol* gsym)
1296 {
1297   switch (r_type)
1298     {
1299     case elfcpp::R_X86_64_NONE:
1300     case elfcpp::R_386_GNU_VTINHERIT:
1301     case elfcpp::R_386_GNU_VTENTRY:
1302       break;
1303
1304     case elfcpp::R_X86_64_64:
1305     case elfcpp::R_X86_64_32:
1306     case elfcpp::R_X86_64_32S:
1307     case elfcpp::R_X86_64_16:
1308     case elfcpp::R_X86_64_8:
1309       {
1310         // Make a PLT entry if necessary.
1311         if (gsym->needs_plt_entry())
1312           {
1313             target->make_plt_entry(symtab, layout, gsym);
1314             // Since this is not a PC-relative relocation, we may be
1315             // taking the address of a function. In that case we need to
1316             // set the entry in the dynamic symbol table to the address of
1317             // the PLT entry.
1318             if (gsym->is_from_dynobj() && !parameters->options().shared())
1319               gsym->set_needs_dynsym_value();
1320           }
1321         // Make a dynamic relocation if necessary.
1322         if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
1323           {
1324             if (gsym->may_need_copy_reloc())
1325               {
1326                 target->copy_reloc(symtab, layout, object,
1327                                    data_shndx, output_section, gsym, reloc);
1328               }
1329             else if (r_type == elfcpp::R_X86_64_64
1330                      && gsym->can_use_relative_reloc(false))
1331               {
1332                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1333                 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_RELATIVE,
1334                                               output_section, object,
1335                                               data_shndx, reloc.get_r_offset(),
1336                                               reloc.get_r_addend());
1337               }
1338             else
1339               {
1340                 this->check_non_pic(object, r_type);
1341                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1342                 rela_dyn->add_global(gsym, r_type, output_section, object,
1343                                      data_shndx, reloc.get_r_offset(),
1344                                      reloc.get_r_addend());
1345               }
1346           }
1347       }
1348       break;
1349
1350     case elfcpp::R_X86_64_PC64:
1351     case elfcpp::R_X86_64_PC32:
1352     case elfcpp::R_X86_64_PC16:
1353     case elfcpp::R_X86_64_PC8:
1354       {
1355         // Make a PLT entry if necessary.
1356         if (gsym->needs_plt_entry())
1357           target->make_plt_entry(symtab, layout, gsym);
1358         // Make a dynamic relocation if necessary.
1359         int flags = Symbol::NON_PIC_REF;
1360         if (gsym->type() == elfcpp::STT_FUNC)
1361           flags |= Symbol::FUNCTION_CALL;
1362         if (gsym->needs_dynamic_reloc(flags))
1363           {
1364             if (gsym->may_need_copy_reloc())
1365               {
1366                 target->copy_reloc(symtab, layout, object,
1367                                    data_shndx, output_section, gsym, reloc);
1368               }
1369             else
1370               {
1371                 this->check_non_pic(object, r_type);
1372                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1373                 rela_dyn->add_global(gsym, r_type, output_section, object,
1374                                      data_shndx, reloc.get_r_offset(),
1375                                      reloc.get_r_addend());
1376               }
1377           }
1378       }
1379       break;
1380
1381     case elfcpp::R_X86_64_GOT64:
1382     case elfcpp::R_X86_64_GOT32:
1383     case elfcpp::R_X86_64_GOTPCREL64:
1384     case elfcpp::R_X86_64_GOTPCREL:
1385     case elfcpp::R_X86_64_GOTPLT64:
1386       {
1387         // The symbol requires a GOT entry.
1388         Output_data_got<64, false>* got = target->got_section(symtab, layout);
1389         if (gsym->final_value_is_known())
1390           got->add_global(gsym, GOT_TYPE_STANDARD);
1391         else
1392           {
1393             // If this symbol is not fully resolved, we need to add a
1394             // dynamic relocation for it.
1395             Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1396             if (gsym->is_from_dynobj()
1397                 || gsym->is_undefined()
1398                 || gsym->is_preemptible())
1399               got->add_global_with_rela(gsym, GOT_TYPE_STANDARD, rela_dyn,
1400                                         elfcpp::R_X86_64_GLOB_DAT);
1401             else
1402               {
1403                 if (got->add_global(gsym, GOT_TYPE_STANDARD))
1404                   rela_dyn->add_global_relative(
1405                       gsym, elfcpp::R_X86_64_RELATIVE, got,
1406                       gsym->got_offset(GOT_TYPE_STANDARD), 0);
1407               }
1408           }
1409         // For GOTPLT64, we also need a PLT entry (but only if the
1410         // symbol is not fully resolved).
1411         if (r_type == elfcpp::R_X86_64_GOTPLT64
1412             && !gsym->final_value_is_known())
1413           target->make_plt_entry(symtab, layout, gsym);
1414       }
1415       break;
1416
1417     case elfcpp::R_X86_64_PLT32:
1418       // If the symbol is fully resolved, this is just a PC32 reloc.
1419       // Otherwise we need a PLT entry.
1420       if (gsym->final_value_is_known())
1421         break;
1422       // If building a shared library, we can also skip the PLT entry
1423       // if the symbol is defined in the output file and is protected
1424       // or hidden.
1425       if (gsym->is_defined()
1426           && !gsym->is_from_dynobj()
1427           && !gsym->is_preemptible())
1428         break;
1429       target->make_plt_entry(symtab, layout, gsym);
1430       break;
1431
1432     case elfcpp::R_X86_64_GOTPC32:
1433     case elfcpp::R_X86_64_GOTOFF64:
1434     case elfcpp::R_X86_64_GOTPC64:
1435     case elfcpp::R_X86_64_PLTOFF64:
1436       // We need a GOT section.
1437       target->got_section(symtab, layout);
1438       // For PLTOFF64, we also need a PLT entry (but only if the
1439       // symbol is not fully resolved).
1440       if (r_type == elfcpp::R_X86_64_PLTOFF64
1441           && !gsym->final_value_is_known())
1442         target->make_plt_entry(symtab, layout, gsym);
1443       break;
1444
1445     case elfcpp::R_X86_64_COPY:
1446     case elfcpp::R_X86_64_GLOB_DAT:
1447     case elfcpp::R_X86_64_JUMP_SLOT:
1448     case elfcpp::R_X86_64_RELATIVE:
1449       // These are outstanding tls relocs, which are unexpected when linking
1450     case elfcpp::R_X86_64_TPOFF64:
1451     case elfcpp::R_X86_64_DTPMOD64:
1452     case elfcpp::R_X86_64_TLSDESC:
1453       gold_error(_("%s: unexpected reloc %u in object file"),
1454                  object->name().c_str(), r_type);
1455       break;
1456
1457       // These are initial tls relocs, which are expected for global()
1458     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
1459     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
1460     case elfcpp::R_X86_64_TLSDESC_CALL:
1461     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
1462     case elfcpp::R_X86_64_DTPOFF32:
1463     case elfcpp::R_X86_64_DTPOFF64:
1464     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
1465     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
1466       {
1467         const bool is_final = gsym->final_value_is_known();
1468         const tls::Tls_optimization optimized_type
1469             = Target_x86_64::optimize_tls_reloc(is_final, r_type);
1470         switch (r_type)
1471           {
1472           case elfcpp::R_X86_64_TLSGD:       // General-dynamic
1473             if (optimized_type == tls::TLSOPT_NONE)
1474               {
1475                 // Create a pair of GOT entries for the module index and
1476                 // dtv-relative offset.
1477                 Output_data_got<64, false>* got
1478                     = target->got_section(symtab, layout);
1479                 got->add_global_pair_with_rela(gsym, GOT_TYPE_TLS_PAIR,
1480                                                target->rela_dyn_section(layout),
1481                                                elfcpp::R_X86_64_DTPMOD64,
1482                                                elfcpp::R_X86_64_DTPOFF64);
1483               }
1484             else if (optimized_type == tls::TLSOPT_TO_IE)
1485               {
1486                 // Create a GOT entry for the tp-relative offset.
1487                 Output_data_got<64, false>* got
1488                     = target->got_section(symtab, layout);
1489                 got->add_global_with_rela(gsym, GOT_TYPE_TLS_OFFSET,
1490                                           target->rela_dyn_section(layout),
1491                                           elfcpp::R_X86_64_TPOFF64);
1492               }
1493             else if (optimized_type != tls::TLSOPT_TO_LE)
1494               unsupported_reloc_global(object, r_type, gsym);
1495             break;
1496
1497           case elfcpp::R_X86_64_GOTPC32_TLSDESC:
1498             target->define_tls_base_symbol(symtab, layout);
1499             if (optimized_type == tls::TLSOPT_NONE)
1500               {
1501                 // Create reserved PLT and GOT entries for the resolver.
1502                 target->reserve_tlsdesc_entries(symtab, layout);
1503
1504                 // Create a double GOT entry with an R_X86_64_TLSDESC reloc.
1505                 Output_data_got<64, false>* got
1506                     = target->got_section(symtab, layout);
1507                 got->add_global_pair_with_rela(gsym, GOT_TYPE_TLS_DESC,
1508                                                target->rela_dyn_section(layout),
1509                                                elfcpp::R_X86_64_TLSDESC, 0);
1510               }
1511             else if (optimized_type == tls::TLSOPT_TO_IE)
1512               {
1513                 // Create a GOT entry for the tp-relative offset.
1514                 Output_data_got<64, false>* got
1515                     = target->got_section(symtab, layout);
1516                 got->add_global_with_rela(gsym, GOT_TYPE_TLS_OFFSET,
1517                                           target->rela_dyn_section(layout),
1518                                           elfcpp::R_X86_64_TPOFF64);
1519               }
1520             else if (optimized_type != tls::TLSOPT_TO_LE)
1521               unsupported_reloc_global(object, r_type, gsym);
1522             break;
1523
1524           case elfcpp::R_X86_64_TLSDESC_CALL:
1525             break;
1526
1527           case elfcpp::R_X86_64_TLSLD:       // Local-dynamic
1528             if (optimized_type == tls::TLSOPT_NONE)
1529               {
1530                 // Create a GOT entry for the module index.
1531                 target->got_mod_index_entry(symtab, layout, object);
1532               }
1533             else if (optimized_type != tls::TLSOPT_TO_LE)
1534               unsupported_reloc_global(object, r_type, gsym);
1535             break;
1536
1537           case elfcpp::R_X86_64_DTPOFF32:
1538           case elfcpp::R_X86_64_DTPOFF64:
1539             break;
1540
1541           case elfcpp::R_X86_64_GOTTPOFF:    // Initial-exec
1542             layout->set_has_static_tls();
1543             if (optimized_type == tls::TLSOPT_NONE)
1544               {
1545                 // Create a GOT entry for the tp-relative offset.
1546                 Output_data_got<64, false>* got
1547                     = target->got_section(symtab, layout);
1548                 got->add_global_with_rela(gsym, GOT_TYPE_TLS_OFFSET,
1549                                           target->rela_dyn_section(layout),
1550                                           elfcpp::R_X86_64_TPOFF64);
1551               }
1552             else if (optimized_type != tls::TLSOPT_TO_LE)
1553               unsupported_reloc_global(object, r_type, gsym);
1554             break;
1555
1556           case elfcpp::R_X86_64_TPOFF32:     // Local-exec
1557             layout->set_has_static_tls();
1558             if (parameters->options().shared())
1559               unsupported_reloc_local(object, r_type);
1560             break;
1561
1562           default:
1563             gold_unreachable();
1564           }
1565       }
1566       break;
1567
1568     case elfcpp::R_X86_64_SIZE32:
1569     case elfcpp::R_X86_64_SIZE64:
1570     default:
1571       gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1572                  object->name().c_str(), r_type,
1573                  gsym->demangled_name().c_str());
1574       break;
1575     }
1576 }
1577
1578 void
1579 Target_x86_64::gc_process_relocs(const General_options& options,
1580                                  Symbol_table* symtab,
1581                                  Layout* layout,
1582                                  Sized_relobj<64, false>* object,
1583                                  unsigned int data_shndx,
1584                                  unsigned int sh_type,
1585                                  const unsigned char* prelocs,
1586                                  size_t reloc_count,
1587                                  Output_section* output_section,
1588                                  bool needs_special_offset_handling,
1589                                  size_t local_symbol_count,
1590                                  const unsigned char* plocal_symbols)
1591 {
1592
1593   if (sh_type == elfcpp::SHT_REL)
1594     {
1595       return;
1596     }
1597
1598    gold::gc_process_relocs<64, false, Target_x86_64, elfcpp::SHT_RELA,
1599                            Target_x86_64::Scan>(
1600     options,
1601     symtab,
1602     layout,
1603     this,
1604     object,
1605     data_shndx,
1606     prelocs,
1607     reloc_count,
1608     output_section,
1609     needs_special_offset_handling,
1610     local_symbol_count,
1611     plocal_symbols);
1612
1613 }
1614 // Scan relocations for a section.
1615
1616 void
1617 Target_x86_64::scan_relocs(const General_options& options,
1618                            Symbol_table* symtab,
1619                            Layout* layout,
1620                            Sized_relobj<64, false>* object,
1621                            unsigned int data_shndx,
1622                            unsigned int sh_type,
1623                            const unsigned char* prelocs,
1624                            size_t reloc_count,
1625                            Output_section* output_section,
1626                            bool needs_special_offset_handling,
1627                            size_t local_symbol_count,
1628                            const unsigned char* plocal_symbols)
1629 {
1630   if (sh_type == elfcpp::SHT_REL)
1631     {
1632       gold_error(_("%s: unsupported REL reloc section"),
1633                  object->name().c_str());
1634       return;
1635     }
1636
1637   gold::scan_relocs<64, false, Target_x86_64, elfcpp::SHT_RELA,
1638       Target_x86_64::Scan>(
1639     options,
1640     symtab,
1641     layout,
1642     this,
1643     object,
1644     data_shndx,
1645     prelocs,
1646     reloc_count,
1647     output_section,
1648     needs_special_offset_handling,
1649     local_symbol_count,
1650     plocal_symbols);
1651 }
1652
1653 // Finalize the sections.
1654
1655 void
1656 Target_x86_64::do_finalize_sections(Layout* layout)
1657 {
1658   // Fill in some more dynamic tags.
1659   Output_data_dynamic* const odyn = layout->dynamic_data();
1660   if (odyn != NULL)
1661     {
1662       if (this->got_plt_ != NULL)
1663         odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_);
1664
1665       if (this->plt_ != NULL)
1666         {
1667           const Output_data* od = this->plt_->rel_plt();
1668           odyn->add_section_size(elfcpp::DT_PLTRELSZ, od);
1669           odyn->add_section_address(elfcpp::DT_JMPREL, od);
1670           odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_RELA);
1671           if (this->plt_->has_tlsdesc_entry())
1672             {
1673               unsigned int plt_offset = this->plt_->get_tlsdesc_plt_offset();
1674               unsigned int got_offset = this->plt_->get_tlsdesc_got_offset();
1675               this->got_->finalize_data_size();
1676               odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_PLT,
1677                                             this->plt_, plt_offset);
1678               odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_GOT,
1679                                             this->got_, got_offset);
1680             }
1681         }
1682
1683       if (this->rela_dyn_ != NULL)
1684         {
1685           const Output_data* od = this->rela_dyn_;
1686           odyn->add_section_address(elfcpp::DT_RELA, od);
1687           odyn->add_section_size(elfcpp::DT_RELASZ, od);
1688           odyn->add_constant(elfcpp::DT_RELAENT,
1689                              elfcpp::Elf_sizes<64>::rela_size);
1690         }
1691
1692       if (!parameters->options().shared())
1693         {
1694           // The value of the DT_DEBUG tag is filled in by the dynamic
1695           // linker at run time, and used by the debugger.
1696           odyn->add_constant(elfcpp::DT_DEBUG, 0);
1697         }
1698     }
1699
1700   // Emit any relocs we saved in an attempt to avoid generating COPY
1701   // relocs.
1702   if (this->copy_relocs_.any_saved_relocs())
1703     this->copy_relocs_.emit(this->rela_dyn_section(layout));
1704 }
1705
1706 // Perform a relocation.
1707
1708 inline bool
1709 Target_x86_64::Relocate::relocate(const Relocate_info<64, false>* relinfo,
1710                                   Target_x86_64* target,
1711                                   Output_section*,
1712                                   size_t relnum,
1713                                   const elfcpp::Rela<64, false>& rela,
1714                                   unsigned int r_type,
1715                                   const Sized_symbol<64>* gsym,
1716                                   const Symbol_value<64>* psymval,
1717                                   unsigned char* view,
1718                                   elfcpp::Elf_types<64>::Elf_Addr address,
1719                                   section_size_type view_size)
1720 {
1721   if (this->skip_call_tls_get_addr_)
1722     {
1723       if ((r_type != elfcpp::R_X86_64_PLT32
1724            && r_type != elfcpp::R_X86_64_PC32)
1725           || gsym == NULL
1726           || strcmp(gsym->name(), "__tls_get_addr") != 0)
1727         {
1728           gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
1729                                  _("missing expected TLS relocation"));
1730         }
1731       else
1732         {
1733           this->skip_call_tls_get_addr_ = false;
1734           return false;
1735         }
1736     }
1737
1738   // Pick the value to use for symbols defined in shared objects.
1739   Symbol_value<64> symval;
1740   if (gsym != NULL
1741       && gsym->use_plt_offset(r_type == elfcpp::R_X86_64_PC64
1742                               || r_type == elfcpp::R_X86_64_PC32
1743                               || r_type == elfcpp::R_X86_64_PC16
1744                               || r_type == elfcpp::R_X86_64_PC8))
1745     {
1746       symval.set_output_value(target->plt_section()->address()
1747                               + gsym->plt_offset());
1748       psymval = &symval;
1749     }
1750
1751   const Sized_relobj<64, false>* object = relinfo->object;
1752   const elfcpp::Elf_Xword addend = rela.get_r_addend();
1753
1754   // Get the GOT offset if needed.
1755   // The GOT pointer points to the end of the GOT section.
1756   // We need to subtract the size of the GOT section to get
1757   // the actual offset to use in the relocation.
1758   bool have_got_offset = false;
1759   unsigned int got_offset = 0;
1760   switch (r_type)
1761     {
1762     case elfcpp::R_X86_64_GOT32:
1763     case elfcpp::R_X86_64_GOT64:
1764     case elfcpp::R_X86_64_GOTPLT64:
1765     case elfcpp::R_X86_64_GOTPCREL:
1766     case elfcpp::R_X86_64_GOTPCREL64:
1767       if (gsym != NULL)
1768         {
1769           gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
1770           got_offset = gsym->got_offset(GOT_TYPE_STANDARD) - target->got_size();
1771         }
1772       else
1773         {
1774           unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
1775           gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
1776           got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
1777                         - target->got_size());
1778         }
1779       have_got_offset = true;
1780       break;
1781
1782     default:
1783       break;
1784     }
1785
1786   switch (r_type)
1787     {
1788     case elfcpp::R_X86_64_NONE:
1789     case elfcpp::R_386_GNU_VTINHERIT:
1790     case elfcpp::R_386_GNU_VTENTRY:
1791       break;
1792
1793     case elfcpp::R_X86_64_64:
1794       Relocate_functions<64, false>::rela64(view, object, psymval, addend);
1795       break;
1796
1797     case elfcpp::R_X86_64_PC64:
1798       Relocate_functions<64, false>::pcrela64(view, object, psymval, addend,
1799                                               address);
1800       break;
1801
1802     case elfcpp::R_X86_64_32:
1803       // FIXME: we need to verify that value + addend fits into 32 bits:
1804       //    uint64_t x = value + addend;
1805       //    x == static_cast<uint64_t>(static_cast<uint32_t>(x))
1806       // Likewise for other <=32-bit relocations (but see R_X86_64_32S).
1807       Relocate_functions<64, false>::rela32(view, object, psymval, addend);
1808       break;
1809
1810     case elfcpp::R_X86_64_32S:
1811       // FIXME: we need to verify that value + addend fits into 32 bits:
1812       //    int64_t x = value + addend;   // note this quantity is signed!
1813       //    x == static_cast<int64_t>(static_cast<int32_t>(x))
1814       Relocate_functions<64, false>::rela32(view, object, psymval, addend);
1815       break;
1816
1817     case elfcpp::R_X86_64_PC32:
1818       Relocate_functions<64, false>::pcrela32(view, object, psymval, addend,
1819                                               address);
1820       break;
1821
1822     case elfcpp::R_X86_64_16:
1823       Relocate_functions<64, false>::rela16(view, object, psymval, addend);
1824       break;
1825
1826     case elfcpp::R_X86_64_PC16:
1827       Relocate_functions<64, false>::pcrela16(view, object, psymval, addend,
1828                                               address);
1829       break;
1830
1831     case elfcpp::R_X86_64_8:
1832       Relocate_functions<64, false>::rela8(view, object, psymval, addend);
1833       break;
1834
1835     case elfcpp::R_X86_64_PC8:
1836       Relocate_functions<64, false>::pcrela8(view, object, psymval, addend,
1837                                              address);
1838       break;
1839
1840     case elfcpp::R_X86_64_PLT32:
1841       gold_assert(gsym == NULL
1842                   || gsym->has_plt_offset()
1843                   || gsym->final_value_is_known()
1844                   || (gsym->is_defined()
1845                       && !gsym->is_from_dynobj()
1846                       && !gsym->is_preemptible()));
1847       // Note: while this code looks the same as for R_X86_64_PC32, it
1848       // behaves differently because psymval was set to point to
1849       // the PLT entry, rather than the symbol, in Scan::global().
1850       Relocate_functions<64, false>::pcrela32(view, object, psymval, addend,
1851                                               address);
1852       break;
1853
1854     case elfcpp::R_X86_64_PLTOFF64:
1855       {
1856         gold_assert(gsym);
1857         gold_assert(gsym->has_plt_offset()
1858                     || gsym->final_value_is_known());
1859         elfcpp::Elf_types<64>::Elf_Addr got_address;
1860         got_address = target->got_section(NULL, NULL)->address();
1861         Relocate_functions<64, false>::rela64(view, object, psymval,
1862                                               addend - got_address);
1863       }
1864
1865     case elfcpp::R_X86_64_GOT32:
1866       gold_assert(have_got_offset);
1867       Relocate_functions<64, false>::rela32(view, got_offset, addend);
1868       break;
1869
1870     case elfcpp::R_X86_64_GOTPC32:
1871       {
1872         gold_assert(gsym);
1873         elfcpp::Elf_types<64>::Elf_Addr value;
1874         value = target->got_plt_section()->address();
1875         Relocate_functions<64, false>::pcrela32(view, value, addend, address);
1876       }
1877       break;
1878
1879     case elfcpp::R_X86_64_GOT64:
1880       // The ABI doc says "Like GOT64, but indicates a PLT entry is needed."
1881       // Since we always add a PLT entry, this is equivalent.
1882     case elfcpp::R_X86_64_GOTPLT64:
1883       gold_assert(have_got_offset);
1884       Relocate_functions<64, false>::rela64(view, got_offset, addend);
1885       break;
1886
1887     case elfcpp::R_X86_64_GOTPC64:
1888       {
1889         gold_assert(gsym);
1890         elfcpp::Elf_types<64>::Elf_Addr value;
1891         value = target->got_plt_section()->address();
1892         Relocate_functions<64, false>::pcrela64(view, value, addend, address);
1893       }
1894       break;
1895
1896     case elfcpp::R_X86_64_GOTOFF64:
1897       {
1898         elfcpp::Elf_types<64>::Elf_Addr value;
1899         value = (psymval->value(object, 0)
1900                  - target->got_plt_section()->address());
1901         Relocate_functions<64, false>::rela64(view, value, addend);
1902       }
1903       break;
1904
1905     case elfcpp::R_X86_64_GOTPCREL:
1906       {
1907         gold_assert(have_got_offset);
1908         elfcpp::Elf_types<64>::Elf_Addr value;
1909         value = target->got_plt_section()->address() + got_offset;
1910         Relocate_functions<64, false>::pcrela32(view, value, addend, address);
1911       }
1912       break;
1913
1914     case elfcpp::R_X86_64_GOTPCREL64:
1915       {
1916         gold_assert(have_got_offset);
1917         elfcpp::Elf_types<64>::Elf_Addr value;
1918         value = target->got_plt_section()->address() + got_offset;
1919         Relocate_functions<64, false>::pcrela64(view, value, addend, address);
1920       }
1921       break;
1922
1923     case elfcpp::R_X86_64_COPY:
1924     case elfcpp::R_X86_64_GLOB_DAT:
1925     case elfcpp::R_X86_64_JUMP_SLOT:
1926     case elfcpp::R_X86_64_RELATIVE:
1927       // These are outstanding tls relocs, which are unexpected when linking
1928     case elfcpp::R_X86_64_TPOFF64:
1929     case elfcpp::R_X86_64_DTPMOD64:
1930     case elfcpp::R_X86_64_TLSDESC:
1931       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
1932                              _("unexpected reloc %u in object file"),
1933                              r_type);
1934       break;
1935
1936       // These are initial tls relocs, which are expected when linking
1937     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
1938     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
1939     case elfcpp::R_X86_64_TLSDESC_CALL:
1940     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
1941     case elfcpp::R_X86_64_DTPOFF32:
1942     case elfcpp::R_X86_64_DTPOFF64:
1943     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
1944     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
1945       this->relocate_tls(relinfo, target, relnum, rela, r_type, gsym, psymval,
1946                          view, address, view_size);
1947       break;
1948
1949     case elfcpp::R_X86_64_SIZE32:
1950     case elfcpp::R_X86_64_SIZE64:
1951     default:
1952       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
1953                              _("unsupported reloc %u"),
1954                              r_type);
1955       break;
1956     }
1957
1958   return true;
1959 }
1960
1961 // Perform a TLS relocation.
1962
1963 inline void
1964 Target_x86_64::Relocate::relocate_tls(const Relocate_info<64, false>* relinfo,
1965                                       Target_x86_64* target,
1966                                       size_t relnum,
1967                                       const elfcpp::Rela<64, false>& rela,
1968                                       unsigned int r_type,
1969                                       const Sized_symbol<64>* gsym,
1970                                       const Symbol_value<64>* psymval,
1971                                       unsigned char* view,
1972                                       elfcpp::Elf_types<64>::Elf_Addr address,
1973                                       section_size_type view_size)
1974 {
1975   Output_segment* tls_segment = relinfo->layout->tls_segment();
1976
1977   const Sized_relobj<64, false>* object = relinfo->object;
1978   const elfcpp::Elf_Xword addend = rela.get_r_addend();
1979
1980   elfcpp::Elf_types<64>::Elf_Addr value = psymval->value(relinfo->object, 0);
1981
1982   const bool is_final = (gsym == NULL
1983                          ? !parameters->options().output_is_position_independent()
1984                          : gsym->final_value_is_known());
1985   const tls::Tls_optimization optimized_type
1986       = Target_x86_64::optimize_tls_reloc(is_final, r_type);
1987   switch (r_type)
1988     {
1989     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
1990       this->saw_tls_block_reloc_ = true;
1991       if (optimized_type == tls::TLSOPT_TO_LE)
1992         {
1993           gold_assert(tls_segment != NULL);
1994           this->tls_gd_to_le(relinfo, relnum, tls_segment,
1995                              rela, r_type, value, view,
1996                              view_size);
1997           break;
1998         }
1999       else
2000         {
2001           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
2002                                    ? GOT_TYPE_TLS_OFFSET
2003                                    : GOT_TYPE_TLS_PAIR);
2004           unsigned int got_offset;
2005           if (gsym != NULL)
2006             {
2007               gold_assert(gsym->has_got_offset(got_type));
2008               got_offset = gsym->got_offset(got_type) - target->got_size();
2009             }
2010           else
2011             {
2012               unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
2013               gold_assert(object->local_has_got_offset(r_sym, got_type));
2014               got_offset = (object->local_got_offset(r_sym, got_type)
2015                             - target->got_size());
2016             }
2017           if (optimized_type == tls::TLSOPT_TO_IE)
2018             {
2019               gold_assert(tls_segment != NULL);
2020               value = target->got_plt_section()->address() + got_offset;
2021               this->tls_gd_to_ie(relinfo, relnum, tls_segment, rela, r_type,
2022                                  value, view, address, view_size);
2023               break;
2024             }
2025           else if (optimized_type == tls::TLSOPT_NONE)
2026             {
2027               // Relocate the field with the offset of the pair of GOT
2028               // entries.
2029               value = target->got_plt_section()->address() + got_offset;
2030               Relocate_functions<64, false>::pcrela32(view, value, addend,
2031                                                       address);
2032               break;
2033             }
2034         }
2035       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
2036                              _("unsupported reloc %u"), r_type);
2037       break;
2038
2039     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
2040     case elfcpp::R_X86_64_TLSDESC_CALL:
2041       this->saw_tls_block_reloc_ = true;
2042       if (optimized_type == tls::TLSOPT_TO_LE)
2043         {
2044           gold_assert(tls_segment != NULL);
2045           this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
2046                                   rela, r_type, value, view,
2047                                   view_size);
2048           break;
2049         }
2050       else
2051         {
2052           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
2053                                    ? GOT_TYPE_TLS_OFFSET
2054                                    : GOT_TYPE_TLS_DESC);
2055           unsigned int got_offset;
2056           if (gsym != NULL)
2057             {
2058               gold_assert(gsym->has_got_offset(got_type));
2059               got_offset = gsym->got_offset(got_type) - target->got_size();
2060             }
2061           else
2062             {
2063               unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
2064               gold_assert(object->local_has_got_offset(r_sym, got_type));
2065               got_offset = (object->local_got_offset(r_sym, got_type)
2066                             - target->got_size());
2067             }
2068           if (optimized_type == tls::TLSOPT_TO_IE)
2069             {
2070               gold_assert(tls_segment != NULL);
2071               value = target->got_plt_section()->address() + got_offset;
2072               this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment,
2073                                       rela, r_type, value, view, address,
2074                                       view_size);
2075               break;
2076             }
2077           else if (optimized_type == tls::TLSOPT_NONE)
2078             {
2079               if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
2080                 {
2081                   // Relocate the field with the offset of the pair of GOT
2082                   // entries.
2083                   value = target->got_plt_section()->address() + got_offset;
2084                   Relocate_functions<64, false>::pcrela32(view, value, addend,
2085                                                           address);
2086                 }
2087               break;
2088             }
2089         }
2090       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
2091                              _("unsupported reloc %u"), r_type);
2092       break;
2093
2094     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
2095       this->saw_tls_block_reloc_ = true;
2096       if (optimized_type == tls::TLSOPT_TO_LE)
2097         {
2098           gold_assert(tls_segment != NULL);
2099           this->tls_ld_to_le(relinfo, relnum, tls_segment, rela, r_type,
2100                              value, view, view_size);
2101           break;
2102         }
2103       else if (optimized_type == tls::TLSOPT_NONE)
2104         {
2105           // Relocate the field with the offset of the GOT entry for
2106           // the module index.
2107           unsigned int got_offset;
2108           got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
2109                         - target->got_size());
2110           value = target->got_plt_section()->address() + got_offset;
2111           Relocate_functions<64, false>::pcrela32(view, value, addend,
2112                                                   address);
2113           break;
2114         }
2115       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
2116                              _("unsupported reloc %u"), r_type);
2117       break;
2118
2119     case elfcpp::R_X86_64_DTPOFF32:
2120       if (optimized_type == tls::TLSOPT_TO_LE)
2121         {
2122           // This relocation type is used in debugging information.
2123           // In that case we need to not optimize the value.  If we
2124           // haven't seen a TLSLD reloc, then we assume we should not
2125           // optimize this reloc.
2126           if (this->saw_tls_block_reloc_)
2127             {
2128               gold_assert(tls_segment != NULL);
2129               value -= tls_segment->memsz();
2130             }
2131         }
2132       Relocate_functions<64, false>::rela32(view, value, addend);
2133       break;
2134
2135     case elfcpp::R_X86_64_DTPOFF64:
2136       if (optimized_type == tls::TLSOPT_TO_LE)
2137         {
2138           // See R_X86_64_DTPOFF32, just above, for why we test this.
2139           if (this->saw_tls_block_reloc_)
2140             {
2141               gold_assert(tls_segment != NULL);
2142               value -= tls_segment->memsz();
2143             }
2144         }
2145       Relocate_functions<64, false>::rela64(view, value, addend);
2146       break;
2147
2148     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
2149       if (optimized_type == tls::TLSOPT_TO_LE)
2150         {
2151           gold_assert(tls_segment != NULL);
2152           Target_x86_64::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
2153                                                 rela, r_type, value, view,
2154                                                 view_size);
2155           break;
2156         }
2157       else if (optimized_type == tls::TLSOPT_NONE)
2158         {
2159           // Relocate the field with the offset of the GOT entry for
2160           // the tp-relative offset of the symbol.
2161           unsigned int got_offset;
2162           if (gsym != NULL)
2163             {
2164               gold_assert(gsym->has_got_offset(GOT_TYPE_TLS_OFFSET));
2165               got_offset = (gsym->got_offset(GOT_TYPE_TLS_OFFSET)
2166                             - target->got_size());
2167             }
2168           else
2169             {
2170               unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
2171               gold_assert(object->local_has_got_offset(r_sym,
2172                                                        GOT_TYPE_TLS_OFFSET));
2173               got_offset = (object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET)
2174                             - target->got_size());
2175             }
2176           value = target->got_plt_section()->address() + got_offset;
2177           Relocate_functions<64, false>::pcrela32(view, value, addend, address);
2178           break;
2179         }
2180       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
2181                              _("unsupported reloc type %u"),
2182                              r_type);
2183       break;
2184
2185     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
2186       value -= tls_segment->memsz();
2187       Relocate_functions<64, false>::rela32(view, value, addend);
2188       break;
2189     }
2190 }
2191
2192 // Do a relocation in which we convert a TLS General-Dynamic to an
2193 // Initial-Exec.
2194
2195 inline void
2196 Target_x86_64::Relocate::tls_gd_to_ie(const Relocate_info<64, false>* relinfo,
2197                                       size_t relnum,
2198                                       Output_segment*,
2199                                       const elfcpp::Rela<64, false>& rela,
2200                                       unsigned int,
2201                                       elfcpp::Elf_types<64>::Elf_Addr value,
2202                                       unsigned char* view,
2203                                       elfcpp::Elf_types<64>::Elf_Addr address,
2204                                       section_size_type view_size)
2205 {
2206   // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
2207   // .word 0x6666; rex64; call __tls_get_addr
2208   // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
2209
2210   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -4);
2211   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
2212
2213   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2214                  (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
2215   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2216                  (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0));
2217
2218   memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0", 16);
2219
2220   const elfcpp::Elf_Xword addend = rela.get_r_addend();
2221   Relocate_functions<64, false>::pcrela32(view + 8, value, addend - 8, address);
2222
2223   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2224   // We can skip it.
2225   this->skip_call_tls_get_addr_ = true;
2226 }
2227
2228 // Do a relocation in which we convert a TLS General-Dynamic to a
2229 // Local-Exec.
2230
2231 inline void
2232 Target_x86_64::Relocate::tls_gd_to_le(const Relocate_info<64, false>* relinfo,
2233                                       size_t relnum,
2234                                       Output_segment* tls_segment,
2235                                       const elfcpp::Rela<64, false>& rela,
2236                                       unsigned int,
2237                                       elfcpp::Elf_types<64>::Elf_Addr value,
2238                                       unsigned char* view,
2239                                       section_size_type view_size)
2240 {
2241   // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
2242   // .word 0x6666; rex64; call __tls_get_addr
2243   // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
2244
2245   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -4);
2246   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
2247
2248   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2249                  (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
2250   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2251                  (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0));
2252
2253   memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0", 16);
2254
2255   value -= tls_segment->memsz();
2256   Relocate_functions<64, false>::rela32(view + 8, value, 0);
2257
2258   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2259   // We can skip it.
2260   this->skip_call_tls_get_addr_ = true;
2261 }
2262
2263 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
2264
2265 inline void
2266 Target_x86_64::Relocate::tls_desc_gd_to_ie(
2267     const Relocate_info<64, false>* relinfo,
2268     size_t relnum,
2269     Output_segment*,
2270     const elfcpp::Rela<64, false>& rela,
2271     unsigned int r_type,
2272     elfcpp::Elf_types<64>::Elf_Addr value,
2273     unsigned char* view,
2274     elfcpp::Elf_types<64>::Elf_Addr address,
2275     section_size_type view_size)
2276 {
2277   if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
2278     {
2279       // leaq foo@tlsdesc(%rip), %rax
2280       // ==> movq foo@gottpoff(%rip), %rax
2281       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
2282       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
2283       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2284                      view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05);
2285       view[-2] = 0x8b;
2286       const elfcpp::Elf_Xword addend = rela.get_r_addend();
2287       Relocate_functions<64, false>::pcrela32(view, value, addend, address);
2288     }
2289   else
2290     {
2291       // call *foo@tlscall(%rax)
2292       // ==> nop; nop
2293       gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
2294       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
2295       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2296                      view[0] == 0xff && view[1] == 0x10);
2297       view[0] = 0x66;
2298       view[1] = 0x90;
2299     }
2300 }
2301
2302 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
2303
2304 inline void
2305 Target_x86_64::Relocate::tls_desc_gd_to_le(
2306     const Relocate_info<64, false>* relinfo,
2307     size_t relnum,
2308     Output_segment* tls_segment,
2309     const elfcpp::Rela<64, false>& rela,
2310     unsigned int r_type,
2311     elfcpp::Elf_types<64>::Elf_Addr value,
2312     unsigned char* view,
2313     section_size_type view_size)
2314 {
2315   if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
2316     {
2317       // leaq foo@tlsdesc(%rip), %rax
2318       // ==> movq foo@tpoff, %rax
2319       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
2320       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
2321       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2322                      view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05);
2323       view[-2] = 0xc7;
2324       view[-1] = 0xc0;
2325       value -= tls_segment->memsz();
2326       Relocate_functions<64, false>::rela32(view, value, 0);
2327     }
2328   else
2329     {
2330       // call *foo@tlscall(%rax)
2331       // ==> nop; nop
2332       gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
2333       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
2334       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2335                      view[0] == 0xff && view[1] == 0x10);
2336       view[0] = 0x66;
2337       view[1] = 0x90;
2338     }
2339 }
2340
2341 inline void
2342 Target_x86_64::Relocate::tls_ld_to_le(const Relocate_info<64, false>* relinfo,
2343                                       size_t relnum,
2344                                       Output_segment*,
2345                                       const elfcpp::Rela<64, false>& rela,
2346                                       unsigned int,
2347                                       elfcpp::Elf_types<64>::Elf_Addr,
2348                                       unsigned char* view,
2349                                       section_size_type view_size)
2350 {
2351   // leaq foo@tlsld(%rip),%rdi; call __tls_get_addr@plt;
2352   // ... leq foo@dtpoff(%rax),%reg
2353   // ==> .word 0x6666; .byte 0x66; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
2354
2355   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
2356   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 9);
2357
2358   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2359                  view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x3d);
2360
2361   tls::check_tls(relinfo, relnum, rela.get_r_offset(), view[4] == 0xe8);
2362
2363   memcpy(view - 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12);
2364
2365   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2366   // We can skip it.
2367   this->skip_call_tls_get_addr_ = true;
2368 }
2369
2370 // Do a relocation in which we convert a TLS Initial-Exec to a
2371 // Local-Exec.
2372
2373 inline void
2374 Target_x86_64::Relocate::tls_ie_to_le(const Relocate_info<64, false>* relinfo,
2375                                       size_t relnum,
2376                                       Output_segment* tls_segment,
2377                                       const elfcpp::Rela<64, false>& rela,
2378                                       unsigned int,
2379                                       elfcpp::Elf_types<64>::Elf_Addr value,
2380                                       unsigned char* view,
2381                                       section_size_type view_size)
2382 {
2383   // We need to examine the opcodes to figure out which instruction we
2384   // are looking at.
2385
2386   // movq foo@gottpoff(%rip),%reg  ==>  movq $YY,%reg
2387   // addq foo@gottpoff(%rip),%reg  ==>  addq $YY,%reg
2388
2389   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
2390   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
2391
2392   unsigned char op1 = view[-3];
2393   unsigned char op2 = view[-2];
2394   unsigned char op3 = view[-1];
2395   unsigned char reg = op3 >> 3;
2396
2397   if (op2 == 0x8b)
2398     {
2399       // movq
2400       if (op1 == 0x4c)
2401         view[-3] = 0x49;
2402       view[-2] = 0xc7;
2403       view[-1] = 0xc0 | reg;
2404     }
2405   else if (reg == 4)
2406     {
2407       // Special handling for %rsp.
2408       if (op1 == 0x4c)
2409         view[-3] = 0x49;
2410       view[-2] = 0x81;
2411       view[-1] = 0xc0 | reg;
2412     }
2413   else
2414     {
2415       // addq
2416       if (op1 == 0x4c)
2417         view[-3] = 0x4d;
2418       view[-2] = 0x8d;
2419       view[-1] = 0x80 | reg | (reg << 3);
2420     }
2421
2422   value -= tls_segment->memsz();
2423   Relocate_functions<64, false>::rela32(view, value, 0);
2424 }
2425
2426 // Relocate section data.
2427
2428 void
2429 Target_x86_64::relocate_section(
2430     const Relocate_info<64, false>* relinfo,
2431     unsigned int sh_type,
2432     const unsigned char* prelocs,
2433     size_t reloc_count,
2434     Output_section* output_section,
2435     bool needs_special_offset_handling,
2436     unsigned char* view,
2437     elfcpp::Elf_types<64>::Elf_Addr address,
2438     section_size_type view_size,
2439     const Reloc_symbol_changes* reloc_symbol_changes)
2440 {
2441   gold_assert(sh_type == elfcpp::SHT_RELA);
2442
2443   gold::relocate_section<64, false, Target_x86_64, elfcpp::SHT_RELA,
2444                          Target_x86_64::Relocate>(
2445     relinfo,
2446     this,
2447     prelocs,
2448     reloc_count,
2449     output_section,
2450     needs_special_offset_handling,
2451     view,
2452     address,
2453     view_size,
2454     reloc_symbol_changes);
2455 }
2456
2457 // Return the size of a relocation while scanning during a relocatable
2458 // link.
2459
2460 unsigned int
2461 Target_x86_64::Relocatable_size_for_reloc::get_size_for_reloc(
2462     unsigned int r_type,
2463     Relobj* object)
2464 {
2465   switch (r_type)
2466     {
2467     case elfcpp::R_X86_64_NONE:
2468     case elfcpp::R_386_GNU_VTINHERIT:
2469     case elfcpp::R_386_GNU_VTENTRY:
2470     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
2471     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
2472     case elfcpp::R_X86_64_TLSDESC_CALL:
2473     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
2474     case elfcpp::R_X86_64_DTPOFF32:
2475     case elfcpp::R_X86_64_DTPOFF64:
2476     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
2477     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
2478       return 0;
2479
2480     case elfcpp::R_X86_64_64:
2481     case elfcpp::R_X86_64_PC64:
2482     case elfcpp::R_X86_64_GOTOFF64:
2483     case elfcpp::R_X86_64_GOTPC64:
2484     case elfcpp::R_X86_64_PLTOFF64:
2485     case elfcpp::R_X86_64_GOT64:
2486     case elfcpp::R_X86_64_GOTPCREL64:
2487     case elfcpp::R_X86_64_GOTPCREL:
2488     case elfcpp::R_X86_64_GOTPLT64:
2489       return 8;
2490
2491     case elfcpp::R_X86_64_32:
2492     case elfcpp::R_X86_64_32S:
2493     case elfcpp::R_X86_64_PC32:
2494     case elfcpp::R_X86_64_PLT32:
2495     case elfcpp::R_X86_64_GOTPC32:
2496     case elfcpp::R_X86_64_GOT32:
2497       return 4;
2498
2499     case elfcpp::R_X86_64_16:
2500     case elfcpp::R_X86_64_PC16:
2501       return 2;
2502
2503     case elfcpp::R_X86_64_8:
2504     case elfcpp::R_X86_64_PC8:
2505       return 1;
2506
2507     case elfcpp::R_X86_64_COPY:
2508     case elfcpp::R_X86_64_GLOB_DAT:
2509     case elfcpp::R_X86_64_JUMP_SLOT:
2510     case elfcpp::R_X86_64_RELATIVE:
2511       // These are outstanding tls relocs, which are unexpected when linking
2512     case elfcpp::R_X86_64_TPOFF64:
2513     case elfcpp::R_X86_64_DTPMOD64:
2514     case elfcpp::R_X86_64_TLSDESC:
2515       object->error(_("unexpected reloc %u in object file"), r_type);
2516       return 0;
2517
2518     case elfcpp::R_X86_64_SIZE32:
2519     case elfcpp::R_X86_64_SIZE64:
2520     default:
2521       object->error(_("unsupported reloc %u against local symbol"), r_type);
2522       return 0;
2523     }
2524 }
2525
2526 // Scan the relocs during a relocatable link.
2527
2528 void
2529 Target_x86_64::scan_relocatable_relocs(const General_options& options,
2530                                        Symbol_table* symtab,
2531                                        Layout* layout,
2532                                        Sized_relobj<64, false>* object,
2533                                        unsigned int data_shndx,
2534                                        unsigned int sh_type,
2535                                        const unsigned char* prelocs,
2536                                        size_t reloc_count,
2537                                        Output_section* output_section,
2538                                        bool needs_special_offset_handling,
2539                                        size_t local_symbol_count,
2540                                        const unsigned char* plocal_symbols,
2541                                        Relocatable_relocs* rr)
2542 {
2543   gold_assert(sh_type == elfcpp::SHT_RELA);
2544
2545   typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_RELA,
2546     Relocatable_size_for_reloc> Scan_relocatable_relocs;
2547
2548   gold::scan_relocatable_relocs<64, false, elfcpp::SHT_RELA,
2549       Scan_relocatable_relocs>(
2550     options,
2551     symtab,
2552     layout,
2553     object,
2554     data_shndx,
2555     prelocs,
2556     reloc_count,
2557     output_section,
2558     needs_special_offset_handling,
2559     local_symbol_count,
2560     plocal_symbols,
2561     rr);
2562 }
2563
2564 // Relocate a section during a relocatable link.
2565
2566 void
2567 Target_x86_64::relocate_for_relocatable(
2568     const Relocate_info<64, false>* relinfo,
2569     unsigned int sh_type,
2570     const unsigned char* prelocs,
2571     size_t reloc_count,
2572     Output_section* output_section,
2573     off_t offset_in_output_section,
2574     const Relocatable_relocs* rr,
2575     unsigned char* view,
2576     elfcpp::Elf_types<64>::Elf_Addr view_address,
2577     section_size_type view_size,
2578     unsigned char* reloc_view,
2579     section_size_type reloc_view_size)
2580 {
2581   gold_assert(sh_type == elfcpp::SHT_RELA);
2582
2583   gold::relocate_for_relocatable<64, false, elfcpp::SHT_RELA>(
2584     relinfo,
2585     prelocs,
2586     reloc_count,
2587     output_section,
2588     offset_in_output_section,
2589     rr,
2590     view,
2591     view_address,
2592     view_size,
2593     reloc_view,
2594     reloc_view_size);
2595 }
2596
2597 // Return the value to use for a dynamic which requires special
2598 // treatment.  This is how we support equality comparisons of function
2599 // pointers across shared library boundaries, as described in the
2600 // processor specific ABI supplement.
2601
2602 uint64_t
2603 Target_x86_64::do_dynsym_value(const Symbol* gsym) const
2604 {
2605   gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
2606   return this->plt_section()->address() + gsym->plt_offset();
2607 }
2608
2609 // Return a string used to fill a code section with nops to take up
2610 // the specified length.
2611
2612 std::string
2613 Target_x86_64::do_code_fill(section_size_type length) const
2614 {
2615   if (length >= 16)
2616     {
2617       // Build a jmpq instruction to skip over the bytes.
2618       unsigned char jmp[5];
2619       jmp[0] = 0xe9;
2620       elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
2621       return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
2622               + std::string(length - 5, '\0'));
2623     }
2624
2625   // Nop sequences of various lengths.
2626   const char nop1[1] = { 0x90 };                   // nop
2627   const char nop2[2] = { 0x66, 0x90 };             // xchg %ax %ax
2628   const char nop3[3] = { 0x0f, 0x1f, 0x00 };       // nop (%rax)
2629   const char nop4[4] = { 0x0f, 0x1f, 0x40, 0x00};  // nop 0(%rax)
2630   const char nop5[5] = { 0x0f, 0x1f, 0x44, 0x00,   // nop 0(%rax,%rax,1)
2631                          0x00 };
2632   const char nop6[6] = { 0x66, 0x0f, 0x1f, 0x44,   // nopw 0(%rax,%rax,1)
2633                          0x00, 0x00 };
2634   const char nop7[7] = { 0x0f, 0x1f, 0x80, 0x00,   // nopl 0L(%rax)
2635                          0x00, 0x00, 0x00 };
2636   const char nop8[8] = { 0x0f, 0x1f, 0x84, 0x00,   // nopl 0L(%rax,%rax,1)
2637                          0x00, 0x00, 0x00, 0x00 };
2638   const char nop9[9] = { 0x66, 0x0f, 0x1f, 0x84,   // nopw 0L(%rax,%rax,1)
2639                          0x00, 0x00, 0x00, 0x00,
2640                          0x00 };
2641   const char nop10[10] = { 0x66, 0x2e, 0x0f, 0x1f, // nopw %cs:0L(%rax,%rax,1)
2642                            0x84, 0x00, 0x00, 0x00,
2643                            0x00, 0x00 };
2644   const char nop11[11] = { 0x66, 0x66, 0x2e, 0x0f, // data16
2645                            0x1f, 0x84, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
2646                            0x00, 0x00, 0x00 };
2647   const char nop12[12] = { 0x66, 0x66, 0x66, 0x2e, // data16; data16
2648                            0x0f, 0x1f, 0x84, 0x00, // nopw %cs:0L(%rax,%rax,1)
2649                            0x00, 0x00, 0x00, 0x00 };
2650   const char nop13[13] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
2651                            0x2e, 0x0f, 0x1f, 0x84, // nopw %cs:0L(%rax,%rax,1)
2652                            0x00, 0x00, 0x00, 0x00,
2653                            0x00 };
2654   const char nop14[14] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
2655                            0x66, 0x2e, 0x0f, 0x1f, // data16
2656                            0x84, 0x00, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
2657                            0x00, 0x00 };
2658   const char nop15[15] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
2659                            0x66, 0x66, 0x2e, 0x0f, // data16; data16
2660                            0x1f, 0x84, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
2661                            0x00, 0x00, 0x00 };
2662
2663   const char* nops[16] = {
2664     NULL,
2665     nop1, nop2, nop3, nop4, nop5, nop6, nop7,
2666     nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
2667   };
2668
2669   return std::string(nops[length], length);
2670 }
2671
2672 // FNOFFSET in section SHNDX in OBJECT is the start of a function
2673 // compiled with -fstack-split.  The function calls non-stack-split
2674 // code.  We have to change the function so that it always ensures
2675 // that it has enough stack space to run some random function.
2676
2677 void
2678 Target_x86_64::do_calls_non_split(Relobj* object, unsigned int shndx,
2679                                   section_offset_type fnoffset,
2680                                   section_size_type fnsize,
2681                                   unsigned char* view,
2682                                   section_size_type view_size,
2683                                   std::string* from,
2684                                   std::string* to) const
2685 {
2686   // The function starts with a comparison of the stack pointer and a
2687   // field in the TCB.  This is followed by a jump.
2688
2689   // cmp %fs:NN,%rsp
2690   if (this->match_view(view, view_size, fnoffset, "\x64\x48\x3b\x24\x25", 5)
2691       && fnsize > 9)
2692     {
2693       // We will call __morestack if the carry flag is set after this
2694       // comparison.  We turn the comparison into an stc instruction
2695       // and some nops.
2696       view[fnoffset] = '\xf9';
2697       this->set_view_to_nop(view, view_size, fnoffset + 1, 8);
2698     }
2699   // lea NN(%rsp),%r10
2700   else if (this->match_view(view, view_size, fnoffset, "\x4c\x8d\x94\x24", 4)
2701            && fnsize > 8)
2702     {
2703       // This is loading an offset from the stack pointer for a
2704       // comparison.  The offset is negative, so we decrease the
2705       // offset by the amount of space we need for the stack.  This
2706       // means we will avoid calling __morestack if there happens to
2707       // be plenty of space on the stack already.
2708       unsigned char* pval = view + fnoffset + 4;
2709       uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
2710       val -= parameters->options().split_stack_adjust_size();
2711       elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
2712     }
2713   else
2714     {
2715       if (!object->has_no_split_stack())
2716         object->error(_("failed to match split-stack sequence at "
2717                         "section %u offset %0zx"),
2718                       shndx, fnoffset);
2719       return;
2720     }
2721
2722   // We have to change the function so that it calls
2723   // __morestack_non_split instead of __morestack.  The former will
2724   // allocate additional stack space.
2725   *from = "__morestack";
2726   *to = "__morestack_non_split";
2727 }
2728
2729 // The selector for x86_64 object files.
2730
2731 class Target_selector_x86_64 : public Target_selector_freebsd
2732 {
2733 public:
2734   Target_selector_x86_64()
2735     : Target_selector_freebsd(elfcpp::EM_X86_64, 64, false, "elf64-x86-64",
2736                               "elf64-x86-64-freebsd")
2737   { }
2738
2739   Target*
2740   do_instantiate_target()
2741   { return new Target_x86_64(); }
2742
2743 };
2744
2745 Target_selector_x86_64 target_selector_x86_64;
2746
2747 } // End anonymous namespace.