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(Symbol_table* symtab,
  78                     Layout* layout,
  79                     Sized_relobj<64, false>* object,
  80                     unsigned int data_shndx,
  81                     unsigned int sh_type,
  82                     const unsigned char* prelocs,
  83                     size_t reloc_count,
  84                     Output_section* output_section,
  85                     bool needs_special_offset_handling,
  86                     size_t local_symbol_count,
  87                     const unsigned char* plocal_symbols);
  88
  89   // Scan the relocations to look for symbol adjustments.
  90   void
  91   scan_relocs(Symbol_table* symtab,
  92               Layout* layout,
  93               Sized_relobj<64, false>* object,
  94               unsigned int data_shndx,
  95               unsigned int sh_type,
  96               const unsigned char* prelocs,
  97               size_t reloc_count,
  98               Output_section* output_section,
  99               bool needs_special_offset_handling,
 100               size_t local_symbol_count,
 101               const unsigned char* plocal_symbols);
 102
 103   // Finalize the sections.
 104   void
 105   do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
 106
 107   // Return the value to use for a dynamic which requires special
 108   // treatment.
 109   uint64_t
 110   do_dynsym_value(const Symbol*) const;
 111
 112   // Relocate a section.
 113   void
 114   relocate_section(const Relocate_info<64, false>*,
 115                    unsigned int sh_type,
 116                    const unsigned char* prelocs,
 117                    size_t reloc_count,
 118                    Output_section* output_section,
 119                    bool needs_special_offset_handling,
 120                    unsigned char* view,
 121                    elfcpp::Elf_types<64>::Elf_Addr view_address,
 122                    section_size_type view_size,
 123                    const Reloc_symbol_changes*);
 124
 125   // Scan the relocs during a relocatable link.
 126   void
 127   scan_relocatable_relocs(Symbol_table* symtab,
 128                           Layout* layout,
 129                           Sized_relobj<64, false>* object,
 130                           unsigned int data_shndx,
 131                           unsigned int sh_type,
 132                           const unsigned char* prelocs,
 133                           size_t reloc_count,
 134                           Output_section* output_section,
 135                           bool needs_special_offset_handling,
 136                           size_t local_symbol_count,
 137                           const unsigned char* plocal_symbols,
 138                           Relocatable_relocs*);
 139
 140   // Relocate a section during a relocatable link.
 141   void
 142   relocate_for_relocatable(const Relocate_info<64, false>*,
 143                            unsigned int sh_type,
 144                            const unsigned char* prelocs,
 145                            size_t reloc_count,
 146                            Output_section* output_section,
 147                            off_t offset_in_output_section,
 148                            const Relocatable_relocs*,
 149                            unsigned char* view,
 150                            elfcpp::Elf_types<64>::Elf_Addr view_address,
 151                            section_size_type view_size,
 152                            unsigned char* reloc_view,
 153                            section_size_type reloc_view_size);
 154
 155   // Return a string used to fill a code section with nops.
 156   std::string
 157   do_code_fill(section_size_type length) const;
 158
 159   // Return whether SYM is defined by the ABI.
 160   bool
 161   do_is_defined_by_abi(const Symbol* sym) const
 162   { return strcmp(sym->name(), "__tls_get_addr") == 0; }
 163
 164   // Adjust -fstack-split code which calls non-stack-split code.
 165   void
 166   do_calls_non_split(Relobj* object, unsigned int shndx,
 167                      section_offset_type fnoffset, section_size_type fnsize,
 168                      unsigned char* view, section_size_type view_size,
 169                      std::string* from, std::string* to) const;
 170
 171   // Return the size of the GOT section.
 172   section_size_type
 173   got_size()
 174   {
 175     gold_assert(this->got_ != NULL);
 176     return this->got_->data_size();
 177   }
 178
 179  private:
 180   // The class which scans relocations.
 181   class Scan
 182   {
 183   public:
 184     Scan()
 185       : issued_non_pic_error_(false)
 186     { }
 187
 188     inline void
 189     local(Symbol_table* symtab, Layout* layout, Target_x86_64* target,
 190           Sized_relobj<64, false>* object,
 191           unsigned int data_shndx,
 192           Output_section* output_section,
 193           const elfcpp::Rela<64, false>& reloc, unsigned int r_type,
 194           const elfcpp::Sym<64, false>& lsym);
 195
 196     inline void
 197     global(Symbol_table* symtab, Layout* layout, Target_x86_64* target,
 198            Sized_relobj<64, false>* object,
 199            unsigned int data_shndx,
 200            Output_section* output_section,
 201            const elfcpp::Rela<64, false>& reloc, unsigned int r_type,
 202            Symbol* gsym);
 203
 204   private:
 205     static void
 206     unsupported_reloc_local(Sized_relobj<64, false>*, unsigned int r_type);
 207
 208     static void
 209     unsupported_reloc_global(Sized_relobj<64, false>*, unsigned int r_type,
 210                              Symbol*);
 211
 212     void
 213     check_non_pic(Relobj*, unsigned int r_type);
 214
 215     // Whether we have issued an error about a non-PIC compilation.
 216     bool issued_non_pic_error_;
 217   };
 218
 219   // The class which implements relocation.
 220   class Relocate
 221   {
 222    public:
 223     Relocate()
 224       : skip_call_tls_get_addr_(false), saw_tls_block_reloc_(false)
 225     { }
 226
 227     ~Relocate()
 228     {
 229       if (this->skip_call_tls_get_addr_)
 230         {
 231           // FIXME: This needs to specify the location somehow.
 232           gold_error(_("missing expected TLS relocation"));
 233         }
 234     }
 235
 236     // Do a relocation.  Return false if the caller should not issue
 237     // any warnings about this relocation.
 238     inline bool
 239     relocate(const Relocate_info<64, false>*, Target_x86_64*, Output_section*,
 240              size_t relnum, const elfcpp::Rela<64, false>&,
 241              unsigned int r_type, const Sized_symbol<64>*,
 242              const Symbol_value<64>*,
 243              unsigned char*, elfcpp::Elf_types<64>::Elf_Addr,
 244              section_size_type);
 245
 246    private:
 247     // Do a TLS relocation.
 248     inline void
 249     relocate_tls(const Relocate_info<64, false>*, Target_x86_64*,
 250                  size_t relnum, const elfcpp::Rela<64, false>&,
 251                  unsigned int r_type, const Sized_symbol<64>*,
 252                  const Symbol_value<64>*,
 253                  unsigned char*, elfcpp::Elf_types<64>::Elf_Addr,
 254                  section_size_type);
 255
 256     // Do a TLS General-Dynamic to Initial-Exec transition.
 257     inline void
 258     tls_gd_to_ie(const Relocate_info<64, false>*, size_t relnum,
 259                  Output_segment* tls_segment,
 260                  const elfcpp::Rela<64, false>&, unsigned int r_type,
 261                  elfcpp::Elf_types<64>::Elf_Addr value,
 262                  unsigned char* view,
 263                  elfcpp::Elf_types<64>::Elf_Addr,
 264                  section_size_type view_size);
 265
 266     // Do a TLS General-Dynamic to Local-Exec transition.
 267     inline void
 268     tls_gd_to_le(const Relocate_info<64, false>*, size_t relnum,
 269                  Output_segment* tls_segment,
 270                  const elfcpp::Rela<64, false>&, unsigned int r_type,
 271                  elfcpp::Elf_types<64>::Elf_Addr value,
 272                  unsigned char* view,
 273                  section_size_type view_size);
 274
 275     // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
 276     inline void
 277     tls_desc_gd_to_ie(const Relocate_info<64, false>*, size_t relnum,
 278                       Output_segment* tls_segment,
 279                       const elfcpp::Rela<64, false>&, unsigned int r_type,
 280                       elfcpp::Elf_types<64>::Elf_Addr value,
 281                       unsigned char* view,
 282                       elfcpp::Elf_types<64>::Elf_Addr,
 283                       section_size_type view_size);
 284
 285     // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
 286     inline void
 287     tls_desc_gd_to_le(const Relocate_info<64, false>*, size_t relnum,
 288                       Output_segment* tls_segment,
 289                       const elfcpp::Rela<64, false>&, unsigned int r_type,
 290                       elfcpp::Elf_types<64>::Elf_Addr value,
 291                       unsigned char* view,
 292                       section_size_type view_size);
 293
 294     // Do a TLS Local-Dynamic to Local-Exec transition.
 295     inline void
 296     tls_ld_to_le(const Relocate_info<64, false>*, size_t relnum,
 297                  Output_segment* tls_segment,
 298                  const elfcpp::Rela<64, false>&, unsigned int r_type,
 299                  elfcpp::Elf_types<64>::Elf_Addr value,
 300                  unsigned char* view,
 301                  section_size_type view_size);
 302
 303     // Do a TLS Initial-Exec to Local-Exec transition.
 304     static inline void
 305     tls_ie_to_le(const Relocate_info<64, false>*, size_t relnum,
 306                  Output_segment* tls_segment,
 307                  const elfcpp::Rela<64, false>&, unsigned int r_type,
 308                  elfcpp::Elf_types<64>::Elf_Addr value,
 309                  unsigned char* view,
 310                  section_size_type view_size);
 311
 312     // This is set if we should skip the next reloc, which should be a
 313     // PLT32 reloc against ___tls_get_addr.
 314     bool skip_call_tls_get_addr_;
 315
 316     // This is set if we see a relocation which could load the address
 317     // of the TLS block.  Whether we see such a relocation determines
 318     // how we handle the R_X86_64_DTPOFF32 relocation, which is used
 319     // in debugging sections.
 320     bool saw_tls_block_reloc_;
 321   };
 322
 323   // A class which returns the size required for a relocation type,
 324   // used while scanning relocs during a relocatable link.
 325   class Relocatable_size_for_reloc
 326   {
 327    public:
 328     unsigned int
 329     get_size_for_reloc(unsigned int, Relobj*);
 330   };
 331
 332   // Adjust TLS relocation type based on the options and whether this
 333   // is a local symbol.
 334   static tls::Tls_optimization
 335   optimize_tls_reloc(bool is_final, int r_type);
 336
 337   // Get the GOT section, creating it if necessary.
 338   Output_data_got<64, false>*
 339   got_section(Symbol_table*, Layout*);
 340
 341   // Get the GOT PLT section.
 342   Output_data_space*
 343   got_plt_section() const
 344   {
 345     gold_assert(this->got_plt_ != NULL);
 346     return this->got_plt_;
 347   }
 348
 349   // Create the PLT section.
 350   void
 351   make_plt_section(Symbol_table* symtab, Layout* layout);
 352
 353   // Create a PLT entry for a global symbol.
 354   void
 355   make_plt_entry(Symbol_table*, Layout*, Symbol*);
 356
 357   // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
 358   void
 359   define_tls_base_symbol(Symbol_table*, Layout*);
 360
 361   // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
 362   void
 363   reserve_tlsdesc_entries(Symbol_table* symtab, Layout* layout);
 364
 365   // Create a GOT entry for the TLS module index.
 366   unsigned int
 367   got_mod_index_entry(Symbol_table* symtab, Layout* layout,
 368                       Sized_relobj<64, false>* object);
 369
 370   // Get the PLT section.
 371   Output_data_plt_x86_64*
 372   plt_section() const
 373   {
 374     gold_assert(this->plt_ != NULL);
 375     return this->plt_;
 376   }
 377
 378   // Get the dynamic reloc section, creating it if necessary.
 379   Reloc_section*
 380   rela_dyn_section(Layout*);
 381
 382   // Add a potential copy relocation.
 383   void
 384   copy_reloc(Symbol_table* symtab, Layout* layout,
 385              Sized_relobj<64, false>* object,
 386              unsigned int shndx, Output_section* output_section,
 387              Symbol* sym, const elfcpp::Rela<64, false>& reloc)
 388   {
 389     this->copy_relocs_.copy_reloc(symtab, layout,
 390                                   symtab->get_sized_symbol<64>(sym),
 391                                   object, shndx, output_section,
 392                                   reloc, this->rela_dyn_section(layout));
 393   }
 394
 395   // Information about this specific target which we pass to the
 396   // general Target structure.
 397   static const Target::Target_info x86_64_info;
 398
 399   enum Got_type
 400   {
 401     GOT_TYPE_STANDARD = 0,      // GOT entry for a regular symbol
 402     GOT_TYPE_TLS_OFFSET = 1,    // GOT entry for TLS offset
 403     GOT_TYPE_TLS_PAIR = 2,      // GOT entry for TLS module/offset pair
 404     GOT_TYPE_TLS_DESC = 3       // GOT entry for TLS_DESC pair
 405   };
 406
 407   // The GOT section.
 408   Output_data_got<64, false>* got_;
 409   // The PLT section.
 410   Output_data_plt_x86_64* plt_;
 411   // The GOT PLT section.
 412   Output_data_space* got_plt_;
 413   // The dynamic reloc section.
 414   Reloc_section* rela_dyn_;
 415   // Relocs saved to avoid a COPY reloc.
 416   Copy_relocs<elfcpp::SHT_RELA, 64, false> copy_relocs_;
 417   // Space for variables copied with a COPY reloc.
 418   Output_data_space* dynbss_;
 419   // Offset of the GOT entry for the TLS module index.
 420   unsigned int got_mod_index_offset_;
 421   // True if the _TLS_MODULE_BASE_ symbol has been defined.
 422   bool tls_base_symbol_defined_;
 423 };
 424
 425 const Target::Target_info Target_x86_64::x86_64_info =
 426 {
 427   64,                   // size
 428   false,                // is_big_endian
 429   elfcpp::EM_X86_64,    // machine_code
 430   false,                // has_make_symbol
 431   false,                // has_resolve
 432   true,                 // has_code_fill
 433   true,                 // is_default_stack_executable
 434   '\0',                 // wrap_char
 435   "/lib/ld64.so.1",     // program interpreter
 436   0x400000,             // default_text_segment_address
 437   0x1000,               // abi_pagesize (overridable by -z max-page-size)
 438   0x1000,               // common_pagesize (overridable by -z common-page-size)
 439   elfcpp::SHN_UNDEF,    // small_common_shndx
 440   elfcpp::SHN_X86_64_LCOMMON,   // large_common_shndx
 441   0,                    // small_common_section_flags
 442   elfcpp::SHF_X86_64_LARGE,     // large_common_section_flags
 443   NULL,                 // attributes_section
 444   NULL                  // attributes_vendor
 445 };
 446
 447 // This is called when a new output section is created.  This is where
 448 // we handle the SHF_X86_64_LARGE.
 449
 450 void
 451 Target_x86_64::do_new_output_section(Output_section *os) const
 452 {
 453   if ((os->flags() & elfcpp::SHF_X86_64_LARGE) != 0)
 454     os->set_is_large_section();
 455 }
 456
 457 // Get the GOT section, creating it if necessary.
 458
 459 Output_data_got<64, false>*
 460 Target_x86_64::got_section(Symbol_table* symtab, Layout* layout)
 461 {
 462   if (this->got_ == NULL)
 463     {
 464       gold_assert(symtab != NULL && layout != NULL);
 465
 466       this->got_ = new Output_data_got<64, false>();
 467
 468       Output_section* os;
 469       os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
 470                                            (elfcpp::SHF_ALLOC
 471                                             | elfcpp::SHF_WRITE),
 472                                            this->got_, false);
 473       os->set_is_relro();
 474
 475       // The old GNU linker creates a .got.plt section.  We just
 476       // create another set of data in the .got section.  Note that we
 477       // always create a PLT if we create a GOT, although the PLT
 478       // might be empty.
 479       this->got_plt_ = new Output_data_space(8, "** GOT PLT");
 480       os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
 481                                            (elfcpp::SHF_ALLOC
 482                                             | elfcpp::SHF_WRITE),
 483                                            this->got_plt_, false);
 484       os->set_is_relro();
 485
 486       // The first three entries are reserved.
 487       this->got_plt_->set_current_data_size(3 * 8);
 488
 489       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
 490       symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
 491                                     this->got_plt_,
 492                                     0, 0, elfcpp::STT_OBJECT,
 493                                     elfcpp::STB_LOCAL,
 494                                     elfcpp::STV_HIDDEN, 0,
 495                                     false, false);
 496     }
 497
 498   return this->got_;
 499 }
 500
 501 // Get the dynamic reloc section, creating it if necessary.
 502
 503 Target_x86_64::Reloc_section*
 504 Target_x86_64::rela_dyn_section(Layout* layout)
 505 {
 506   if (this->rela_dyn_ == NULL)
 507     {
 508       gold_assert(layout != NULL);
 509       this->rela_dyn_ = new Reloc_section(parameters->options().combreloc());
 510       layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
 511                                       elfcpp::SHF_ALLOC, this->rela_dyn_, true);
 512     }
 513   return this->rela_dyn_;
 514 }
 515
 516 // A class to handle the PLT data.
 517
 518 class Output_data_plt_x86_64 : public Output_section_data
 519 {
 520  public:
 521   typedef Output_data_reloc<elfcpp::SHT_RELA, true, 64, false> Reloc_section;
 522
 523   Output_data_plt_x86_64(Layout*, Output_data_got<64, false>*,
 524                          Output_data_space*);
 525
 526   // Add an entry to the PLT.
 527   void
 528   add_entry(Symbol* gsym);
 529
 530   // Add the reserved TLSDESC_PLT entry to the PLT.
 531   void
 532   reserve_tlsdesc_entry(unsigned int got_offset)
 533   { this->tlsdesc_got_offset_ = got_offset; }
 534
 535   // Return true if a TLSDESC_PLT entry has been reserved.
 536   bool
 537   has_tlsdesc_entry() const
 538   { return this->tlsdesc_got_offset_ != -1U; }
 539
 540   // Return the GOT offset for the reserved TLSDESC_PLT entry.
 541   unsigned int
 542   get_tlsdesc_got_offset() const
 543   { return this->tlsdesc_got_offset_; }
 544
 545   // Return the offset of the reserved TLSDESC_PLT entry.
 546   unsigned int
 547   get_tlsdesc_plt_offset() const
 548   { return (this->count_ + 1) * plt_entry_size; }
 549
 550   // Return the .rel.plt section data.
 551   const Reloc_section*
 552   rel_plt() const
 553   { return this->rel_; }
 554
 555  protected:
 556   void
 557   do_adjust_output_section(Output_section* os);
 558
 559   // Write to a map file.
 560   void
 561   do_print_to_mapfile(Mapfile* mapfile) const
 562   { mapfile->print_output_data(this, _("** PLT")); }
 563
 564  private:
 565   // The size of an entry in the PLT.
 566   static const int plt_entry_size = 16;
 567
 568   // The first entry in the PLT.
 569   // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
 570   // procedure linkage table for both programs and shared objects."
 571   static unsigned char first_plt_entry[plt_entry_size];
 572
 573   // Other entries in the PLT for an executable.
 574   static unsigned char plt_entry[plt_entry_size];
 575
 576   // The reserved TLSDESC entry in the PLT for an executable.
 577   static unsigned char tlsdesc_plt_entry[plt_entry_size];
 578
 579   // Set the final size.
 580   void
 581   set_final_data_size();
 582
 583   // Write out the PLT data.
 584   void
 585   do_write(Output_file*);
 586
 587   // The reloc section.
 588   Reloc_section* rel_;
 589   // The .got section.
 590   Output_data_got<64, false>* got_;
 591   // The .got.plt section.
 592   Output_data_space* got_plt_;
 593   // The number of PLT entries.
 594   unsigned int count_;
 595   // Offset of the reserved TLSDESC_GOT entry when needed.
 596   unsigned int tlsdesc_got_offset_;
 597 };
 598
 599 // Create the PLT section.  The ordinary .got section is an argument,
 600 // since we need to refer to the start.  We also create our own .got
 601 // section just for PLT entries.
 602
 603 Output_data_plt_x86_64::Output_data_plt_x86_64(Layout* layout,
 604                                                Output_data_got<64, false>* got,
 605                                                Output_data_space* got_plt)
 606   : Output_section_data(8), got_(got), got_plt_(got_plt), count_(0),
 607     tlsdesc_got_offset_(-1U)
 608 {
 609   this->rel_ = new Reloc_section(false);
 610   layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
 611                                   elfcpp::SHF_ALLOC, this->rel_, true);
 612 }
 613
 614 void
 615 Output_data_plt_x86_64::do_adjust_output_section(Output_section* os)
 616 {
 617   os->set_entsize(plt_entry_size);
 618 }
 619
 620 // Add an entry to the PLT.
 621
 622 void
 623 Output_data_plt_x86_64::add_entry(Symbol* gsym)
 624 {
 625   gold_assert(!gsym->has_plt_offset());
 626
 627   // Note that when setting the PLT offset we skip the initial
 628   // reserved PLT entry.
 629   gsym->set_plt_offset((this->count_ + 1) * plt_entry_size);
 630
 631   ++this->count_;
 632
 633   section_offset_type got_offset = this->got_plt_->current_data_size();
 634
 635   // Every PLT entry needs a GOT entry which points back to the PLT
 636   // entry (this will be changed by the dynamic linker, normally
 637   // lazily when the function is called).
 638   this->got_plt_->set_current_data_size(got_offset + 8);
 639
 640   // Every PLT entry needs a reloc.
 641   gsym->set_needs_dynsym_entry();
 642   this->rel_->add_global(gsym, elfcpp::R_X86_64_JUMP_SLOT, this->got_plt_,
 643                          got_offset, 0);
 644
 645   // Note that we don't need to save the symbol.  The contents of the
 646   // PLT are independent of which symbols are used.  The symbols only
 647   // appear in the relocations.
 648 }
 649
 650 // Set the final size.
 651 void
 652 Output_data_plt_x86_64::set_final_data_size()
 653 {
 654   unsigned int count = this->count_;
 655   if (this->has_tlsdesc_entry())
 656     ++count;
 657   this->set_data_size((count + 1) * plt_entry_size);
 658 }
 659
 660 // The first entry in the PLT for an executable.
 661
 662 unsigned char Output_data_plt_x86_64::first_plt_entry[plt_entry_size] =
 663 {
 664   // From AMD64 ABI Draft 0.98, page 76
 665   0xff, 0x35,   // pushq contents of memory address
 666   0, 0, 0, 0,   // replaced with address of .got + 8
 667   0xff, 0x25,   // jmp indirect
 668   0, 0, 0, 0,   // replaced with address of .got + 16
 669   0x90, 0x90, 0x90, 0x90   // noop (x4)
 670 };
 671
 672 // Subsequent entries in the PLT for an executable.
 673
 674 unsigned char Output_data_plt_x86_64::plt_entry[plt_entry_size] =
 675 {
 676   // From AMD64 ABI Draft 0.98, page 76
 677   0xff, 0x25,   // jmpq indirect
 678   0, 0, 0, 0,   // replaced with address of symbol in .got
 679   0x68,         // pushq immediate
 680   0, 0, 0, 0,   // replaced with offset into relocation table
 681   0xe9,         // jmpq relative
 682   0, 0, 0, 0    // replaced with offset to start of .plt
 683 };
 684
 685 // The reserved TLSDESC entry in the PLT for an executable.
 686
 687 unsigned char Output_data_plt_x86_64::tlsdesc_plt_entry[plt_entry_size] =
 688 {
 689   // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
 690   // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
 691   0xff, 0x35,   // pushq x(%rip)
 692   0, 0, 0, 0,   // replaced with address of linkmap GOT entry (at PLTGOT + 8)
 693   0xff, 0x25,   // jmpq *y(%rip)
 694   0, 0, 0, 0,   // replaced with offset of reserved TLSDESC_GOT entry
 695   0x0f, 0x1f,   // nop
 696   0x40, 0
 697 };
 698
 699 // Write out the PLT.  This uses the hand-coded instructions above,
 700 // and adjusts them as needed.  This is specified by the AMD64 ABI.
 701
 702 void
 703 Output_data_plt_x86_64::do_write(Output_file* of)
 704 {
 705   const off_t offset = this->offset();
 706   const section_size_type oview_size =
 707     convert_to_section_size_type(this->data_size());
 708   unsigned char* const oview = of->get_output_view(offset, oview_size);
 709
 710   const off_t got_file_offset = this->got_plt_->offset();
 711   const section_size_type got_size =
 712     convert_to_section_size_type(this->got_plt_->data_size());
 713   unsigned char* const got_view = of->get_output_view(got_file_offset,
 714                                                       got_size);
 715
 716   unsigned char* pov = oview;
 717
 718   // The base address of the .plt section.
 719   elfcpp::Elf_types<64>::Elf_Addr plt_address = this->address();
 720   // The base address of the .got section.
 721   elfcpp::Elf_types<64>::Elf_Addr got_base = this->got_->address();
 722   // The base address of the PLT portion of the .got section,
 723   // which is where the GOT pointer will point, and where the
 724   // three reserved GOT entries are located.
 725   elfcpp::Elf_types<64>::Elf_Addr got_address = this->got_plt_->address();
 726
 727   memcpy(pov, first_plt_entry, plt_entry_size);
 728   // We do a jmp relative to the PC at the end of this instruction.
 729   elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
 730                                               (got_address + 8
 731                                                - (plt_address + 6)));
 732   elfcpp::Swap<32, false>::writeval(pov + 8,
 733                                     (got_address + 16
 734                                      - (plt_address + 12)));
 735   pov += plt_entry_size;
 736
 737   unsigned char* got_pov = got_view;
 738
 739   memset(got_pov, 0, 24);
 740   got_pov += 24;
 741
 742   unsigned int plt_offset = plt_entry_size;
 743   unsigned int got_offset = 24;
 744   const unsigned int count = this->count_;
 745   for (unsigned int plt_index = 0;
 746        plt_index < count;
 747        ++plt_index,
 748          pov += plt_entry_size,
 749          got_pov += 8,
 750          plt_offset += plt_entry_size,
 751          got_offset += 8)
 752     {
 753       // Set and adjust the PLT entry itself.
 754       memcpy(pov, plt_entry, plt_entry_size);
 755       elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
 756                                                   (got_address + got_offset
 757                                                    - (plt_address + plt_offset
 758                                                       + 6)));
 759
 760       elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_index);
 761       elfcpp::Swap<32, false>::writeval(pov + 12,
 762                                         - (plt_offset + plt_entry_size));
 763
 764       // Set the entry in the GOT.
 765       elfcpp::Swap<64, false>::writeval(got_pov, plt_address + plt_offset + 6);
 766     }
 767
 768   if (this->has_tlsdesc_entry())
 769     {
 770       // Set and adjust the reserved TLSDESC PLT entry.
 771       unsigned int tlsdesc_got_offset = this->get_tlsdesc_got_offset();
 772       memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
 773       elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
 774                                                   (got_address + 8
 775                                                    - (plt_address + plt_offset
 776                                                       + 6)));
 777       elfcpp::Swap_unaligned<32, false>::writeval(pov + 8,
 778                                                   (got_base
 779                                                    + tlsdesc_got_offset
 780                                                    - (plt_address + plt_offset
 781                                                       + 12)));
 782       pov += plt_entry_size;
 783     }
 784
 785   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
 786   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
 787
 788   of->write_output_view(offset, oview_size, oview);
 789   of->write_output_view(got_file_offset, got_size, got_view);
 790 }
 791
 792 // Create the PLT section.
 793
 794 void
 795 Target_x86_64::make_plt_section(Symbol_table* symtab, Layout* layout)
 796 {
 797   if (this->plt_ == NULL)
 798     {
 799       // Create the GOT sections first.
 800       this->got_section(symtab, layout);
 801
 802       this->plt_ = new Output_data_plt_x86_64(layout, this->got_,
 803                                               this->got_plt_);
 804       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
 805                                       (elfcpp::SHF_ALLOC
 806                                        | elfcpp::SHF_EXECINSTR),
 807                                       this->plt_, false);
 808     }
 809 }
 810
 811 // Create a PLT entry for a global symbol.
 812
 813 void
 814 Target_x86_64::make_plt_entry(Symbol_table* symtab, Layout* layout,
 815                               Symbol* gsym)
 816 {
 817   if (gsym->has_plt_offset())
 818     return;
 819
 820   if (this->plt_ == NULL)
 821     this->make_plt_section(symtab, layout);
 822
 823   this->plt_->add_entry(gsym);
 824 }
 825
 826 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
 827
 828 void
 829 Target_x86_64::define_tls_base_symbol(Symbol_table* symtab, Layout* layout)
 830 {
 831   if (this->tls_base_symbol_defined_)
 832     return;
 833
 834   Output_segment* tls_segment = layout->tls_segment();
 835   if (tls_segment != NULL)
 836     {
 837       bool is_exec = parameters->options().output_is_executable();
 838       symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
 839                                        tls_segment, 0, 0,
 840                                        elfcpp::STT_TLS,
 841                                        elfcpp::STB_LOCAL,
 842                                        elfcpp::STV_HIDDEN, 0,
 843                                        (is_exec
 844                                         ? Symbol::SEGMENT_END
 845                                         : Symbol::SEGMENT_START),
 846                                        true);
 847     }
 848   this->tls_base_symbol_defined_ = true;
 849 }
 850
 851 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
 852
 853 void
 854 Target_x86_64::reserve_tlsdesc_entries(Symbol_table* symtab,
 855                                              Layout* layout)
 856 {
 857   if (this->plt_ == NULL)
 858     this->make_plt_section(symtab, layout);
 859
 860   if (!this->plt_->has_tlsdesc_entry())
 861     {
 862       // Allocate the TLSDESC_GOT entry.
 863       Output_data_got<64, false>* got = this->got_section(symtab, layout);
 864       unsigned int got_offset = got->add_constant(0);
 865
 866       // Allocate the TLSDESC_PLT entry.
 867       this->plt_->reserve_tlsdesc_entry(got_offset);
 868     }
 869 }
 870
 871 // Create a GOT entry for the TLS module index.
 872
 873 unsigned int
 874 Target_x86_64::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
 875                                    Sized_relobj<64, false>* object)
 876 {
 877   if (this->got_mod_index_offset_ == -1U)
 878     {
 879       gold_assert(symtab != NULL && layout != NULL && object != NULL);
 880       Reloc_section* rela_dyn = this->rela_dyn_section(layout);
 881       Output_data_got<64, false>* got = this->got_section(symtab, layout);
 882       unsigned int got_offset = got->add_constant(0);
 883       rela_dyn->add_local(object, 0, elfcpp::R_X86_64_DTPMOD64, got,
 884                           got_offset, 0);
 885       got->add_constant(0);
 886       this->got_mod_index_offset_ = got_offset;
 887     }
 888   return this->got_mod_index_offset_;
 889 }
 890
 891 // Optimize the TLS relocation type based on what we know about the
 892 // symbol.  IS_FINAL is true if the final address of this symbol is
 893 // known at link time.
 894
 895 tls::Tls_optimization
 896 Target_x86_64::optimize_tls_reloc(bool is_final, int r_type)
 897 {
 898   // If we are generating a shared library, then we can't do anything
 899   // in the linker.
 900   if (parameters->options().shared())
 901     return tls::TLSOPT_NONE;
 902
 903   switch (r_type)
 904     {
 905     case elfcpp::R_X86_64_TLSGD:
 906     case elfcpp::R_X86_64_GOTPC32_TLSDESC:
 907     case elfcpp::R_X86_64_TLSDESC_CALL:
 908       // These are General-Dynamic which permits fully general TLS
 909       // access.  Since we know that we are generating an executable,
 910       // we can convert this to Initial-Exec.  If we also know that
 911       // this is a local symbol, we can further switch to Local-Exec.
 912       if (is_final)
 913         return tls::TLSOPT_TO_LE;
 914       return tls::TLSOPT_TO_IE;
 915
 916     case elfcpp::R_X86_64_TLSLD:
 917       // This is Local-Dynamic, which refers to a local symbol in the
 918       // dynamic TLS block.  Since we know that we generating an
 919       // executable, we can switch to Local-Exec.
 920       return tls::TLSOPT_TO_LE;
 921
 922     case elfcpp::R_X86_64_DTPOFF32:
 923     case elfcpp::R_X86_64_DTPOFF64:
 924       // Another Local-Dynamic reloc.
 925       return tls::TLSOPT_TO_LE;
 926
 927     case elfcpp::R_X86_64_GOTTPOFF:
 928       // These are Initial-Exec relocs which get the thread offset
 929       // from the GOT.  If we know that we are linking against the
 930       // local symbol, we can switch to Local-Exec, which links the
 931       // thread offset into the instruction.
 932       if (is_final)
 933         return tls::TLSOPT_TO_LE;
 934       return tls::TLSOPT_NONE;
 935
 936     case elfcpp::R_X86_64_TPOFF32:
 937       // When we already have Local-Exec, there is nothing further we
 938       // can do.
 939       return tls::TLSOPT_NONE;
 940
 941     default:
 942       gold_unreachable();
 943     }
 944 }
 945
 946 // Report an unsupported relocation against a local symbol.
 947
 948 void
 949 Target_x86_64::Scan::unsupported_reloc_local(Sized_relobj<64, false>* object,
 950                                              unsigned int r_type)
 951 {
 952   gold_error(_("%s: unsupported reloc %u against local symbol"),
 953              object->name().c_str(), r_type);
 954 }
 955
 956 // We are about to emit a dynamic relocation of type R_TYPE.  If the
 957 // dynamic linker does not support it, issue an error.  The GNU linker
 958 // only issues a non-PIC error for an allocated read-only section.
 959 // Here we know the section is allocated, but we don't know that it is
 960 // read-only.  But we check for all the relocation types which the
 961 // glibc dynamic linker supports, so it seems appropriate to issue an
 962 // error even if the section is not read-only.
 963
 964 void
 965 Target_x86_64::Scan::check_non_pic(Relobj* object, unsigned int r_type)
 966 {
 967   switch (r_type)
 968     {
 969       // These are the relocation types supported by glibc for x86_64.
 970     case elfcpp::R_X86_64_RELATIVE:
 971     case elfcpp::R_X86_64_GLOB_DAT:
 972     case elfcpp::R_X86_64_JUMP_SLOT:
 973     case elfcpp::R_X86_64_DTPMOD64:
 974     case elfcpp::R_X86_64_DTPOFF64:
 975     case elfcpp::R_X86_64_TPOFF64:
 976     case elfcpp::R_X86_64_64:
 977     case elfcpp::R_X86_64_32:
 978     case elfcpp::R_X86_64_PC32:
 979     case elfcpp::R_X86_64_COPY:
 980       return;
 981
 982     default:
 983       // This prevents us from issuing more than one error per reloc
 984       // section.  But we can still wind up issuing more than one
 985       // error per object file.
 986       if (this->issued_non_pic_error_)
 987         return;
 988       gold_assert(parameters->options().output_is_position_independent());
 989       object->error(_("requires unsupported dynamic reloc; "
 990                       "recompile with -fPIC"));
 991       this->issued_non_pic_error_ = true;
 992       return;
 993
 994     case elfcpp::R_X86_64_NONE:
 995       gold_unreachable();
 996     }
 997 }
 998
 999 // Scan a relocation for a local symbol.
1000
1001 inline void
1002 Target_x86_64::Scan::local(Symbol_table* symtab,
1003                            Layout* layout,
1004                            Target_x86_64* target,
1005                            Sized_relobj<64, false>* object,
1006                            unsigned int data_shndx,
1007                            Output_section* output_section,
1008                            const elfcpp::Rela<64, false>& reloc,
1009                            unsigned int r_type,
1010                            const elfcpp::Sym<64, false>& lsym)
1011 {
1012   switch (r_type)
1013     {
1014     case elfcpp::R_X86_64_NONE:
1015     case elfcpp::R_386_GNU_VTINHERIT:
1016     case elfcpp::R_386_GNU_VTENTRY:
1017       break;
1018
1019     case elfcpp::R_X86_64_64:
1020       // If building a shared library (or a position-independent
1021       // executable), we need to create a dynamic relocation for this
1022       // location.  The relocation applied at link time will apply the
1023       // link-time value, so we flag the location with an
1024       // R_X86_64_RELATIVE relocation so the dynamic loader can
1025       // relocate it easily.
1026       if (parameters->options().output_is_position_independent())
1027         {
1028           unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
1029           Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1030           rela_dyn->add_local_relative(object, r_sym,
1031                                        elfcpp::R_X86_64_RELATIVE,
1032                                        output_section, data_shndx,
1033                                        reloc.get_r_offset(),
1034                                        reloc.get_r_addend());
1035         }
1036       break;
1037
1038     case elfcpp::R_X86_64_32:
1039     case elfcpp::R_X86_64_32S:
1040     case elfcpp::R_X86_64_16:
1041     case elfcpp::R_X86_64_8:
1042       // If building a shared library (or a position-independent
1043       // executable), we need to create a dynamic relocation for this
1044       // location.  We can't use an R_X86_64_RELATIVE relocation
1045       // because that is always a 64-bit relocation.
1046       if (parameters->options().output_is_position_independent())
1047         {
1048           this->check_non_pic(object, r_type);
1049
1050           Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1051           unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
1052           if (lsym.get_st_type() != elfcpp::STT_SECTION)
1053             rela_dyn->add_local(object, r_sym, r_type, output_section,
1054                                 data_shndx, reloc.get_r_offset(),
1055                                 reloc.get_r_addend());
1056           else
1057             {
1058               gold_assert(lsym.get_st_value() == 0);
1059               unsigned int shndx = lsym.get_st_shndx();
1060               bool is_ordinary;
1061               shndx = object->adjust_sym_shndx(r_sym, shndx,
1062                                                &is_ordinary);
1063               if (!is_ordinary)
1064                 object->error(_("section symbol %u has bad shndx %u"),
1065                               r_sym, shndx);
1066               else
1067                 rela_dyn->add_local_section(object, shndx,
1068                                             r_type, output_section,
1069                                             data_shndx, reloc.get_r_offset(),
1070                                             reloc.get_r_addend());
1071             }
1072         }
1073       break;
1074
1075     case elfcpp::R_X86_64_PC64:
1076     case elfcpp::R_X86_64_PC32:
1077     case elfcpp::R_X86_64_PC16:
1078     case elfcpp::R_X86_64_PC8:
1079       break;
1080
1081     case elfcpp::R_X86_64_PLT32:
1082       // Since we know this is a local symbol, we can handle this as a
1083       // PC32 reloc.
1084       break;
1085
1086     case elfcpp::R_X86_64_GOTPC32:
1087     case elfcpp::R_X86_64_GOTOFF64:
1088     case elfcpp::R_X86_64_GOTPC64:
1089     case elfcpp::R_X86_64_PLTOFF64:
1090       // We need a GOT section.
1091       target->got_section(symtab, layout);
1092       // For PLTOFF64, we'd normally want a PLT section, but since we
1093       // know this is a local symbol, no PLT is needed.
1094       break;
1095
1096     case elfcpp::R_X86_64_GOT64:
1097     case elfcpp::R_X86_64_GOT32:
1098     case elfcpp::R_X86_64_GOTPCREL64:
1099     case elfcpp::R_X86_64_GOTPCREL:
1100     case elfcpp::R_X86_64_GOTPLT64:
1101       {
1102         // The symbol requires a GOT entry.
1103         Output_data_got<64, false>* got = target->got_section(symtab, layout);
1104         unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
1105         if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
1106           {
1107             // If we are generating a shared object, we need to add a
1108             // dynamic relocation for this symbol's GOT entry.
1109             if (parameters->options().output_is_position_independent())
1110               {
1111                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1112                 // R_X86_64_RELATIVE assumes a 64-bit relocation.
1113                 if (r_type != elfcpp::R_X86_64_GOT32)
1114                   rela_dyn->add_local_relative(
1115                       object, r_sym, elfcpp::R_X86_64_RELATIVE, got,
1116                       object->local_got_offset(r_sym, GOT_TYPE_STANDARD), 0);
1117                 else
1118                   {
1119                     this->check_non_pic(object, r_type);
1120
1121                     gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
1122                     rela_dyn->add_local(
1123                         object, r_sym, r_type, got,
1124                         object->local_got_offset(r_sym, GOT_TYPE_STANDARD), 0);
1125                   }
1126               }
1127           }
1128         // For GOTPLT64, we'd normally want a PLT section, but since
1129         // we know this is a local symbol, no PLT is needed.
1130       }
1131       break;
1132
1133     case elfcpp::R_X86_64_COPY:
1134     case elfcpp::R_X86_64_GLOB_DAT:
1135     case elfcpp::R_X86_64_JUMP_SLOT:
1136     case elfcpp::R_X86_64_RELATIVE:
1137       // These are outstanding tls relocs, which are unexpected when linking
1138     case elfcpp::R_X86_64_TPOFF64:
1139     case elfcpp::R_X86_64_DTPMOD64:
1140     case elfcpp::R_X86_64_TLSDESC:
1141       gold_error(_("%s: unexpected reloc %u in object file"),
1142                  object->name().c_str(), r_type);
1143       break;
1144
1145       // These are initial tls relocs, which are expected when linking
1146     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
1147     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
1148     case elfcpp::R_X86_64_TLSDESC_CALL:
1149     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
1150     case elfcpp::R_X86_64_DTPOFF32:
1151     case elfcpp::R_X86_64_DTPOFF64:
1152     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
1153     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
1154       {
1155         bool output_is_shared = parameters->options().shared();
1156         const tls::Tls_optimization optimized_type
1157             = Target_x86_64::optimize_tls_reloc(!output_is_shared, r_type);
1158         switch (r_type)
1159           {
1160           case elfcpp::R_X86_64_TLSGD:       // General-dynamic
1161             if (optimized_type == tls::TLSOPT_NONE)
1162               {
1163                 // Create a pair of GOT entries for the module index and
1164                 // dtv-relative offset.
1165                 Output_data_got<64, false>* got
1166                     = target->got_section(symtab, layout);
1167                 unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
1168                 unsigned int shndx = lsym.get_st_shndx();
1169                 bool is_ordinary;
1170                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1171                 if (!is_ordinary)
1172                   object->error(_("local symbol %u has bad shndx %u"),
1173                               r_sym, shndx);
1174                 else
1175                   got->add_local_pair_with_rela(object, r_sym,
1176                                                 shndx,
1177                                                 GOT_TYPE_TLS_PAIR,
1178                                                 target->rela_dyn_section(layout),
1179                                                 elfcpp::R_X86_64_DTPMOD64, 0);
1180               }
1181             else if (optimized_type != tls::TLSOPT_TO_LE)
1182               unsupported_reloc_local(object, r_type);
1183             break;
1184
1185           case elfcpp::R_X86_64_GOTPC32_TLSDESC:
1186             target->define_tls_base_symbol(symtab, layout);
1187             if (optimized_type == tls::TLSOPT_NONE)
1188               {
1189                 // Create reserved PLT and GOT entries for the resolver.
1190                 target->reserve_tlsdesc_entries(symtab, layout);
1191
1192                 // Generate a double GOT entry with an R_X86_64_TLSDESC reloc.
1193                 Output_data_got<64, false>* got
1194                     = target->got_section(symtab, layout);
1195                 unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
1196                 unsigned int shndx = lsym.get_st_shndx();
1197                 bool is_ordinary;
1198                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1199                 if (!is_ordinary)
1200                   object->error(_("local symbol %u has bad shndx %u"),
1201                               r_sym, shndx);
1202                 else
1203                   got->add_local_pair_with_rela(object, r_sym,
1204                                                 shndx,
1205                                                 GOT_TYPE_TLS_DESC,
1206                                                 target->rela_dyn_section(layout),
1207                                                 elfcpp::R_X86_64_TLSDESC, 0);
1208               }
1209             else if (optimized_type != tls::TLSOPT_TO_LE)
1210               unsupported_reloc_local(object, r_type);
1211             break;
1212
1213           case elfcpp::R_X86_64_TLSDESC_CALL:
1214             break;
1215
1216           case elfcpp::R_X86_64_TLSLD:       // Local-dynamic
1217             if (optimized_type == tls::TLSOPT_NONE)
1218               {
1219                 // Create a GOT entry for the module index.
1220                 target->got_mod_index_entry(symtab, layout, object);
1221               }
1222             else if (optimized_type != tls::TLSOPT_TO_LE)
1223               unsupported_reloc_local(object, r_type);
1224             break;
1225
1226           case elfcpp::R_X86_64_DTPOFF32:
1227           case elfcpp::R_X86_64_DTPOFF64:
1228             break;
1229
1230           case elfcpp::R_X86_64_GOTTPOFF:    // Initial-exec
1231             layout->set_has_static_tls();
1232             if (optimized_type == tls::TLSOPT_NONE)
1233               {
1234                 // Create a GOT entry for the tp-relative offset.
1235                 Output_data_got<64, false>* got
1236                     = target->got_section(symtab, layout);
1237                 unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
1238                 got->add_local_with_rela(object, r_sym, GOT_TYPE_TLS_OFFSET,
1239                                          target->rela_dyn_section(layout),
1240                                          elfcpp::R_X86_64_TPOFF64);
1241               }
1242             else if (optimized_type != tls::TLSOPT_TO_LE)
1243               unsupported_reloc_local(object, r_type);
1244             break;
1245
1246           case elfcpp::R_X86_64_TPOFF32:     // Local-exec
1247             layout->set_has_static_tls();
1248             if (output_is_shared)
1249               unsupported_reloc_local(object, r_type);
1250             break;
1251
1252           default:
1253             gold_unreachable();
1254           }
1255       }
1256       break;
1257
1258     case elfcpp::R_X86_64_SIZE32:
1259     case elfcpp::R_X86_64_SIZE64:
1260     default:
1261       gold_error(_("%s: unsupported reloc %u against local symbol"),
1262                  object->name().c_str(), r_type);
1263       break;
1264     }
1265 }
1266
1267
1268 // Report an unsupported relocation against a global symbol.
1269
1270 void
1271 Target_x86_64::Scan::unsupported_reloc_global(Sized_relobj<64, false>* object,
1272                                               unsigned int r_type,
1273                                               Symbol* gsym)
1274 {
1275   gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1276              object->name().c_str(), r_type, gsym->demangled_name().c_str());
1277 }
1278
1279 // Scan a relocation for a global symbol.
1280
1281 inline void
1282 Target_x86_64::Scan::global(Symbol_table* symtab,
1283                             Layout* layout,
1284                             Target_x86_64* target,
1285                             Sized_relobj<64, false>* object,
1286                             unsigned int data_shndx,
1287                             Output_section* output_section,
1288                             const elfcpp::Rela<64, false>& reloc,
1289                             unsigned int r_type,
1290                             Symbol* gsym)
1291 {
1292   switch (r_type)
1293     {
1294     case elfcpp::R_X86_64_NONE:
1295     case elfcpp::R_386_GNU_VTINHERIT:
1296     case elfcpp::R_386_GNU_VTENTRY:
1297       break;
1298
1299     case elfcpp::R_X86_64_64:
1300     case elfcpp::R_X86_64_32:
1301     case elfcpp::R_X86_64_32S:
1302     case elfcpp::R_X86_64_16:
1303     case elfcpp::R_X86_64_8:
1304       {
1305         // Make a PLT entry if necessary.
1306         if (gsym->needs_plt_entry())
1307           {
1308             target->make_plt_entry(symtab, layout, gsym);
1309             // Since this is not a PC-relative relocation, we may be
1310             // taking the address of a function. In that case we need to
1311             // set the entry in the dynamic symbol table to the address of
1312             // the PLT entry.
1313             if (gsym->is_from_dynobj() && !parameters->options().shared())
1314               gsym->set_needs_dynsym_value();
1315           }
1316         // Make a dynamic relocation if necessary.
1317         if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
1318           {
1319             if (gsym->may_need_copy_reloc())
1320               {
1321                 target->copy_reloc(symtab, layout, object,
1322                                    data_shndx, output_section, gsym, reloc);
1323               }
1324             else if (r_type == elfcpp::R_X86_64_64
1325                      && gsym->can_use_relative_reloc(false))
1326               {
1327                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1328                 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_RELATIVE,
1329                                               output_section, object,
1330                                               data_shndx, reloc.get_r_offset(),
1331                                               reloc.get_r_addend());
1332               }
1333             else
1334               {
1335                 this->check_non_pic(object, r_type);
1336                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1337                 rela_dyn->add_global(gsym, r_type, output_section, object,
1338                                      data_shndx, reloc.get_r_offset(),
1339                                      reloc.get_r_addend());
1340               }
1341           }
1342       }
1343       break;
1344
1345     case elfcpp::R_X86_64_PC64:
1346     case elfcpp::R_X86_64_PC32:
1347     case elfcpp::R_X86_64_PC16:
1348     case elfcpp::R_X86_64_PC8:
1349       {
1350         // Make a PLT entry if necessary.
1351         if (gsym->needs_plt_entry())
1352           target->make_plt_entry(symtab, layout, gsym);
1353         // Make a dynamic relocation if necessary.
1354         int flags = Symbol::NON_PIC_REF;
1355         if (gsym->is_func())
1356           flags |= Symbol::FUNCTION_CALL;
1357         if (gsym->needs_dynamic_reloc(flags))
1358           {
1359             if (gsym->may_need_copy_reloc())
1360               {
1361                 target->copy_reloc(symtab, layout, object,
1362                                    data_shndx, output_section, gsym, reloc);
1363               }
1364             else
1365               {
1366                 this->check_non_pic(object, r_type);
1367                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1368                 rela_dyn->add_global(gsym, r_type, output_section, object,
1369                                      data_shndx, reloc.get_r_offset(),
1370                                      reloc.get_r_addend());
1371               }
1372           }
1373       }
1374       break;
1375
1376     case elfcpp::R_X86_64_GOT64:
1377     case elfcpp::R_X86_64_GOT32:
1378     case elfcpp::R_X86_64_GOTPCREL64:
1379     case elfcpp::R_X86_64_GOTPCREL:
1380     case elfcpp::R_X86_64_GOTPLT64:
1381       {
1382         // The symbol requires a GOT entry.
1383         Output_data_got<64, false>* got = target->got_section(symtab, layout);
1384         if (gsym->final_value_is_known())
1385           got->add_global(gsym, GOT_TYPE_STANDARD);
1386         else
1387           {
1388             // If this symbol is not fully resolved, we need to add a
1389             // dynamic relocation for it.
1390             Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1391             if (gsym->is_from_dynobj()
1392                 || gsym->is_undefined()
1393                 || gsym->is_preemptible())
1394               got->add_global_with_rela(gsym, GOT_TYPE_STANDARD, rela_dyn,
1395                                         elfcpp::R_X86_64_GLOB_DAT);
1396             else
1397               {
1398                 if (got->add_global(gsym, GOT_TYPE_STANDARD))
1399                   rela_dyn->add_global_relative(
1400                       gsym, elfcpp::R_X86_64_RELATIVE, got,
1401                       gsym->got_offset(GOT_TYPE_STANDARD), 0);
1402               }
1403           }
1404         // For GOTPLT64, we also need a PLT entry (but only if the
1405         // symbol is not fully resolved).
1406         if (r_type == elfcpp::R_X86_64_GOTPLT64
1407             && !gsym->final_value_is_known())
1408           target->make_plt_entry(symtab, layout, gsym);
1409       }
1410       break;
1411
1412     case elfcpp::R_X86_64_PLT32:
1413       // If the symbol is fully resolved, this is just a PC32 reloc.
1414       // Otherwise we need a PLT entry.
1415       if (gsym->final_value_is_known())
1416         break;
1417       // If building a shared library, we can also skip the PLT entry
1418       // if the symbol is defined in the output file and is protected
1419       // or hidden.
1420       if (gsym->is_defined()
1421           && !gsym->is_from_dynobj()
1422           && !gsym->is_preemptible())
1423         break;
1424       target->make_plt_entry(symtab, layout, gsym);
1425       break;
1426
1427     case elfcpp::R_X86_64_GOTPC32:
1428     case elfcpp::R_X86_64_GOTOFF64:
1429     case elfcpp::R_X86_64_GOTPC64:
1430     case elfcpp::R_X86_64_PLTOFF64:
1431       // We need a GOT section.
1432       target->got_section(symtab, layout);
1433       // For PLTOFF64, we also need a PLT entry (but only if the
1434       // symbol is not fully resolved).
1435       if (r_type == elfcpp::R_X86_64_PLTOFF64
1436           && !gsym->final_value_is_known())
1437         target->make_plt_entry(symtab, layout, gsym);
1438       break;
1439
1440     case elfcpp::R_X86_64_COPY:
1441     case elfcpp::R_X86_64_GLOB_DAT:
1442     case elfcpp::R_X86_64_JUMP_SLOT:
1443     case elfcpp::R_X86_64_RELATIVE:
1444       // These are outstanding tls relocs, which are unexpected when linking
1445     case elfcpp::R_X86_64_TPOFF64:
1446     case elfcpp::R_X86_64_DTPMOD64:
1447     case elfcpp::R_X86_64_TLSDESC:
1448       gold_error(_("%s: unexpected reloc %u in object file"),
1449                  object->name().c_str(), r_type);
1450       break;
1451
1452       // These are initial tls relocs, which are expected for global()
1453     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
1454     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
1455     case elfcpp::R_X86_64_TLSDESC_CALL:
1456     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
1457     case elfcpp::R_X86_64_DTPOFF32:
1458     case elfcpp::R_X86_64_DTPOFF64:
1459     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
1460     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
1461       {
1462         const bool is_final = gsym->final_value_is_known();
1463         const tls::Tls_optimization optimized_type
1464             = Target_x86_64::optimize_tls_reloc(is_final, r_type);
1465         switch (r_type)
1466           {
1467           case elfcpp::R_X86_64_TLSGD:       // General-dynamic
1468             if (optimized_type == tls::TLSOPT_NONE)
1469               {
1470                 // Create a pair of GOT entries for the module index and
1471                 // dtv-relative offset.
1472                 Output_data_got<64, false>* got
1473                     = target->got_section(symtab, layout);
1474                 got->add_global_pair_with_rela(gsym, GOT_TYPE_TLS_PAIR,
1475                                                target->rela_dyn_section(layout),
1476                                                elfcpp::R_X86_64_DTPMOD64,
1477                                                elfcpp::R_X86_64_DTPOFF64);
1478               }
1479             else if (optimized_type == tls::TLSOPT_TO_IE)
1480               {
1481                 // Create a GOT entry for the tp-relative offset.
1482                 Output_data_got<64, false>* got
1483                     = target->got_section(symtab, layout);
1484                 got->add_global_with_rela(gsym, GOT_TYPE_TLS_OFFSET,
1485                                           target->rela_dyn_section(layout),
1486                                           elfcpp::R_X86_64_TPOFF64);
1487               }
1488             else if (optimized_type != tls::TLSOPT_TO_LE)
1489               unsupported_reloc_global(object, r_type, gsym);
1490             break;
1491
1492           case elfcpp::R_X86_64_GOTPC32_TLSDESC:
1493             target->define_tls_base_symbol(symtab, layout);
1494             if (optimized_type == tls::TLSOPT_NONE)
1495               {
1496                 // Create reserved PLT and GOT entries for the resolver.
1497                 target->reserve_tlsdesc_entries(symtab, layout);
1498
1499                 // Create a double GOT entry with an R_X86_64_TLSDESC reloc.
1500                 Output_data_got<64, false>* got
1501                     = target->got_section(symtab, layout);
1502                 got->add_global_pair_with_rela(gsym, GOT_TYPE_TLS_DESC,
1503                                                target->rela_dyn_section(layout),
1504                                                elfcpp::R_X86_64_TLSDESC, 0);
1505               }
1506             else if (optimized_type == tls::TLSOPT_TO_IE)
1507               {
1508                 // Create a GOT entry for the tp-relative offset.
1509                 Output_data_got<64, false>* got
1510                     = target->got_section(symtab, layout);
1511                 got->add_global_with_rela(gsym, GOT_TYPE_TLS_OFFSET,
1512                                           target->rela_dyn_section(layout),
1513                                           elfcpp::R_X86_64_TPOFF64);
1514               }
1515             else if (optimized_type != tls::TLSOPT_TO_LE)
1516               unsupported_reloc_global(object, r_type, gsym);
1517             break;
1518
1519           case elfcpp::R_X86_64_TLSDESC_CALL:
1520             break;
1521
1522           case elfcpp::R_X86_64_TLSLD:       // Local-dynamic
1523             if (optimized_type == tls::TLSOPT_NONE)
1524               {
1525                 // Create a GOT entry for the module index.
1526                 target->got_mod_index_entry(symtab, layout, object);
1527               }
1528             else if (optimized_type != tls::TLSOPT_TO_LE)
1529               unsupported_reloc_global(object, r_type, gsym);
1530             break;
1531
1532           case elfcpp::R_X86_64_DTPOFF32:
1533           case elfcpp::R_X86_64_DTPOFF64:
1534             break;
1535
1536           case elfcpp::R_X86_64_GOTTPOFF:    // Initial-exec
1537             layout->set_has_static_tls();
1538             if (optimized_type == tls::TLSOPT_NONE)
1539               {
1540                 // Create a GOT entry for the tp-relative offset.
1541                 Output_data_got<64, false>* got
1542                     = target->got_section(symtab, layout);
1543                 got->add_global_with_rela(gsym, GOT_TYPE_TLS_OFFSET,
1544                                           target->rela_dyn_section(layout),
1545                                           elfcpp::R_X86_64_TPOFF64);
1546               }
1547             else if (optimized_type != tls::TLSOPT_TO_LE)
1548               unsupported_reloc_global(object, r_type, gsym);
1549             break;
1550
1551           case elfcpp::R_X86_64_TPOFF32:     // Local-exec
1552             layout->set_has_static_tls();
1553             if (parameters->options().shared())
1554               unsupported_reloc_local(object, r_type);
1555             break;
1556
1557           default:
1558             gold_unreachable();
1559           }
1560       }
1561       break;
1562
1563     case elfcpp::R_X86_64_SIZE32:
1564     case elfcpp::R_X86_64_SIZE64:
1565     default:
1566       gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1567                  object->name().c_str(), r_type,
1568                  gsym->demangled_name().c_str());
1569       break;
1570     }
1571 }
1572
1573 void
1574 Target_x86_64::gc_process_relocs(Symbol_table* symtab,
1575                                  Layout* layout,
1576                                  Sized_relobj<64, false>* object,
1577                                  unsigned int data_shndx,
1578                                  unsigned int sh_type,
1579                                  const unsigned char* prelocs,
1580                                  size_t reloc_count,
1581                                  Output_section* output_section,
1582                                  bool needs_special_offset_handling,
1583                                  size_t local_symbol_count,
1584                                  const unsigned char* plocal_symbols)
1585 {
1586
1587   if (sh_type == elfcpp::SHT_REL)
1588     {
1589       return;
1590     }
1591
1592    gold::gc_process_relocs<64, false, Target_x86_64, elfcpp::SHT_RELA,
1593                            Target_x86_64::Scan>(
1594     symtab,
1595     layout,
1596     this,
1597     object,
1598     data_shndx,
1599     prelocs,
1600     reloc_count,
1601     output_section,
1602     needs_special_offset_handling,
1603     local_symbol_count,
1604     plocal_symbols);
1605
1606 }
1607 // Scan relocations for a section.
1608
1609 void
1610 Target_x86_64::scan_relocs(Symbol_table* symtab,
1611                            Layout* layout,
1612                            Sized_relobj<64, false>* object,
1613                            unsigned int data_shndx,
1614                            unsigned int sh_type,
1615                            const unsigned char* prelocs,
1616                            size_t reloc_count,
1617                            Output_section* output_section,
1618                            bool needs_special_offset_handling,
1619                            size_t local_symbol_count,
1620                            const unsigned char* plocal_symbols)
1621 {
1622   if (sh_type == elfcpp::SHT_REL)
1623     {
1624       gold_error(_("%s: unsupported REL reloc section"),
1625                  object->name().c_str());
1626       return;
1627     }
1628
1629   gold::scan_relocs<64, false, Target_x86_64, elfcpp::SHT_RELA,
1630       Target_x86_64::Scan>(
1631     symtab,
1632     layout,
1633     this,
1634     object,
1635     data_shndx,
1636     prelocs,
1637     reloc_count,
1638     output_section,
1639     needs_special_offset_handling,
1640     local_symbol_count,
1641     plocal_symbols);
1642 }
1643
1644 // Finalize the sections.
1645
1646 void
1647 Target_x86_64::do_finalize_sections(
1648     Layout* layout,
1649     const Input_objects*,
1650     Symbol_table*)
1651 {
1652   // Fill in some more dynamic tags.
1653   Output_data_dynamic* const odyn = layout->dynamic_data();
1654   if (odyn != NULL)
1655     {
1656       if (this->got_plt_ != NULL
1657           && this->got_plt_->output_section() != NULL)
1658         odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_);
1659
1660       if (this->plt_ != NULL
1661           && this->plt_->output_section() != NULL)
1662         {
1663           const Output_data* od = this->plt_->rel_plt();
1664           odyn->add_section_size(elfcpp::DT_PLTRELSZ, od);
1665           odyn->add_section_address(elfcpp::DT_JMPREL, od);
1666           odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_RELA);
1667           if (this->plt_->has_tlsdesc_entry())
1668             {
1669               unsigned int plt_offset = this->plt_->get_tlsdesc_plt_offset();
1670               unsigned int got_offset = this->plt_->get_tlsdesc_got_offset();
1671               this->got_->finalize_data_size();
1672               odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_PLT,
1673                                             this->plt_, plt_offset);
1674               odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_GOT,
1675                                             this->got_, got_offset);
1676             }
1677         }
1678
1679       if (this->rela_dyn_ != NULL
1680           && this->rela_dyn_->output_section() != NULL)
1681         {
1682           const Output_data* od = this->rela_dyn_;
1683           odyn->add_section_address(elfcpp::DT_RELA, od);
1684           odyn->add_section_size(elfcpp::DT_RELASZ, od);
1685           odyn->add_constant(elfcpp::DT_RELAENT,
1686                              elfcpp::Elf_sizes<64>::rela_size);
1687         }
1688
1689       if (!parameters->options().shared())
1690         {
1691           // The value of the DT_DEBUG tag is filled in by the dynamic
1692           // linker at run time, and used by the debugger.
1693           odyn->add_constant(elfcpp::DT_DEBUG, 0);
1694         }
1695     }
1696
1697   // Emit any relocs we saved in an attempt to avoid generating COPY
1698   // relocs.
1699   if (this->copy_relocs_.any_saved_relocs())
1700     this->copy_relocs_.emit(this->rela_dyn_section(layout));
1701 }
1702
1703 // Perform a relocation.
1704
1705 inline bool
1706 Target_x86_64::Relocate::relocate(const Relocate_info<64, false>* relinfo,
1707                                   Target_x86_64* target,
1708                                   Output_section*,
1709                                   size_t relnum,
1710                                   const elfcpp::Rela<64, false>& rela,
1711                                   unsigned int r_type,
1712                                   const Sized_symbol<64>* gsym,
1713                                   const Symbol_value<64>* psymval,
1714                                   unsigned char* view,
1715                                   elfcpp::Elf_types<64>::Elf_Addr address,
1716                                   section_size_type view_size)
1717 {
1718   if (this->skip_call_tls_get_addr_)
1719     {
1720       if ((r_type != elfcpp::R_X86_64_PLT32
1721            && r_type != elfcpp::R_X86_64_PC32)
1722           || gsym == NULL
1723           || strcmp(gsym->name(), "__tls_get_addr") != 0)
1724         {
1725           gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
1726                                  _("missing expected TLS relocation"));
1727         }
1728       else
1729         {
1730           this->skip_call_tls_get_addr_ = false;
1731           return false;
1732         }
1733     }
1734
1735   // Pick the value to use for symbols defined in shared objects.
1736   Symbol_value<64> symval;
1737   if (gsym != NULL
1738       && gsym->use_plt_offset(r_type == elfcpp::R_X86_64_PC64
1739                               || r_type == elfcpp::R_X86_64_PC32
1740                               || r_type == elfcpp::R_X86_64_PC16
1741                               || r_type == elfcpp::R_X86_64_PC8))
1742     {
1743       symval.set_output_value(target->plt_section()->address()
1744                               + gsym->plt_offset());
1745       psymval = &symval;
1746     }
1747
1748   const Sized_relobj<64, false>* object = relinfo->object;
1749   const elfcpp::Elf_Xword addend = rela.get_r_addend();
1750
1751   // Get the GOT offset if needed.
1752   // The GOT pointer points to the end of the GOT section.
1753   // We need to subtract the size of the GOT section to get
1754   // the actual offset to use in the relocation.
1755   bool have_got_offset = false;
1756   unsigned int got_offset = 0;
1757   switch (r_type)
1758     {
1759     case elfcpp::R_X86_64_GOT32:
1760     case elfcpp::R_X86_64_GOT64:
1761     case elfcpp::R_X86_64_GOTPLT64:
1762     case elfcpp::R_X86_64_GOTPCREL:
1763     case elfcpp::R_X86_64_GOTPCREL64:
1764       if (gsym != NULL)
1765         {
1766           gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
1767           got_offset = gsym->got_offset(GOT_TYPE_STANDARD) - target->got_size();
1768         }
1769       else
1770         {
1771           unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
1772           gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
1773           got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
1774                         - target->got_size());
1775         }
1776       have_got_offset = true;
1777       break;
1778
1779     default:
1780       break;
1781     }
1782
1783   switch (r_type)
1784     {
1785     case elfcpp::R_X86_64_NONE:
1786     case elfcpp::R_386_GNU_VTINHERIT:
1787     case elfcpp::R_386_GNU_VTENTRY:
1788       break;
1789
1790     case elfcpp::R_X86_64_64:
1791       Relocate_functions<64, false>::rela64(view, object, psymval, addend);
1792       break;
1793
1794     case elfcpp::R_X86_64_PC64:
1795       Relocate_functions<64, false>::pcrela64(view, object, psymval, addend,
1796                                               address);
1797       break;
1798
1799     case elfcpp::R_X86_64_32:
1800       // FIXME: we need to verify that value + addend fits into 32 bits:
1801       //    uint64_t x = value + addend;
1802       //    x == static_cast<uint64_t>(static_cast<uint32_t>(x))
1803       // Likewise for other <=32-bit relocations (but see R_X86_64_32S).
1804       Relocate_functions<64, false>::rela32(view, object, psymval, addend);
1805       break;
1806
1807     case elfcpp::R_X86_64_32S:
1808       // FIXME: we need to verify that value + addend fits into 32 bits:
1809       //    int64_t x = value + addend;   // note this quantity is signed!
1810       //    x == static_cast<int64_t>(static_cast<int32_t>(x))
1811       Relocate_functions<64, false>::rela32(view, object, psymval, addend);
1812       break;
1813
1814     case elfcpp::R_X86_64_PC32:
1815       Relocate_functions<64, false>::pcrela32(view, object, psymval, addend,
1816                                               address);
1817       break;
1818
1819     case elfcpp::R_X86_64_16:
1820       Relocate_functions<64, false>::rela16(view, object, psymval, addend);
1821       break;
1822
1823     case elfcpp::R_X86_64_PC16:
1824       Relocate_functions<64, false>::pcrela16(view, object, psymval, addend,
1825                                               address);
1826       break;
1827
1828     case elfcpp::R_X86_64_8:
1829       Relocate_functions<64, false>::rela8(view, object, psymval, addend);
1830       break;
1831
1832     case elfcpp::R_X86_64_PC8:
1833       Relocate_functions<64, false>::pcrela8(view, object, psymval, addend,
1834                                              address);
1835       break;
1836
1837     case elfcpp::R_X86_64_PLT32:
1838       gold_assert(gsym == NULL
1839                   || gsym->has_plt_offset()
1840                   || gsym->final_value_is_known()
1841                   || (gsym->is_defined()
1842                       && !gsym->is_from_dynobj()
1843                       && !gsym->is_preemptible()));
1844       // Note: while this code looks the same as for R_X86_64_PC32, it
1845       // behaves differently because psymval was set to point to
1846       // the PLT entry, rather than the symbol, in Scan::global().
1847       Relocate_functions<64, false>::pcrela32(view, object, psymval, addend,
1848                                               address);
1849       break;
1850
1851     case elfcpp::R_X86_64_PLTOFF64:
1852       {
1853         gold_assert(gsym);
1854         gold_assert(gsym->has_plt_offset()
1855                     || gsym->final_value_is_known());
1856         elfcpp::Elf_types<64>::Elf_Addr got_address;
1857         got_address = target->got_section(NULL, NULL)->address();
1858         Relocate_functions<64, false>::rela64(view, object, psymval,
1859                                               addend - got_address);
1860       }
1861
1862     case elfcpp::R_X86_64_GOT32:
1863       gold_assert(have_got_offset);
1864       Relocate_functions<64, false>::rela32(view, got_offset, addend);
1865       break;
1866
1867     case elfcpp::R_X86_64_GOTPC32:
1868       {
1869         gold_assert(gsym);
1870         elfcpp::Elf_types<64>::Elf_Addr value;
1871         value = target->got_plt_section()->address();
1872         Relocate_functions<64, false>::pcrela32(view, value, addend, address);
1873       }
1874       break;
1875
1876     case elfcpp::R_X86_64_GOT64:
1877       // The ABI doc says "Like GOT64, but indicates a PLT entry is needed."
1878       // Since we always add a PLT entry, this is equivalent.
1879     case elfcpp::R_X86_64_GOTPLT64:
1880       gold_assert(have_got_offset);
1881       Relocate_functions<64, false>::rela64(view, got_offset, addend);
1882       break;
1883
1884     case elfcpp::R_X86_64_GOTPC64:
1885       {
1886         gold_assert(gsym);
1887         elfcpp::Elf_types<64>::Elf_Addr value;
1888         value = target->got_plt_section()->address();
1889         Relocate_functions<64, false>::pcrela64(view, value, addend, address);
1890       }
1891       break;
1892
1893     case elfcpp::R_X86_64_GOTOFF64:
1894       {
1895         elfcpp::Elf_types<64>::Elf_Addr value;
1896         value = (psymval->value(object, 0)
1897                  - target->got_plt_section()->address());
1898         Relocate_functions<64, false>::rela64(view, value, addend);
1899       }
1900       break;
1901
1902     case elfcpp::R_X86_64_GOTPCREL:
1903       {
1904         gold_assert(have_got_offset);
1905         elfcpp::Elf_types<64>::Elf_Addr value;
1906         value = target->got_plt_section()->address() + got_offset;
1907         Relocate_functions<64, false>::pcrela32(view, value, addend, address);
1908       }
1909       break;
1910
1911     case elfcpp::R_X86_64_GOTPCREL64:
1912       {
1913         gold_assert(have_got_offset);
1914         elfcpp::Elf_types<64>::Elf_Addr value;
1915         value = target->got_plt_section()->address() + got_offset;
1916         Relocate_functions<64, false>::pcrela64(view, value, addend, address);
1917       }
1918       break;
1919
1920     case elfcpp::R_X86_64_COPY:
1921     case elfcpp::R_X86_64_GLOB_DAT:
1922     case elfcpp::R_X86_64_JUMP_SLOT:
1923     case elfcpp::R_X86_64_RELATIVE:
1924       // These are outstanding tls relocs, which are unexpected when linking
1925     case elfcpp::R_X86_64_TPOFF64:
1926     case elfcpp::R_X86_64_DTPMOD64:
1927     case elfcpp::R_X86_64_TLSDESC:
1928       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
1929                              _("unexpected reloc %u in object file"),
1930                              r_type);
1931       break;
1932
1933       // These are initial tls relocs, which are expected when linking
1934     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
1935     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
1936     case elfcpp::R_X86_64_TLSDESC_CALL:
1937     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
1938     case elfcpp::R_X86_64_DTPOFF32:
1939     case elfcpp::R_X86_64_DTPOFF64:
1940     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
1941     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
1942       this->relocate_tls(relinfo, target, relnum, rela, r_type, gsym, psymval,
1943                          view, address, view_size);
1944       break;
1945
1946     case elfcpp::R_X86_64_SIZE32:
1947     case elfcpp::R_X86_64_SIZE64:
1948     default:
1949       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
1950                              _("unsupported reloc %u"),
1951                              r_type);
1952       break;
1953     }
1954
1955   return true;
1956 }
1957
1958 // Perform a TLS relocation.
1959
1960 inline void
1961 Target_x86_64::Relocate::relocate_tls(const Relocate_info<64, false>* relinfo,
1962                                       Target_x86_64* target,
1963                                       size_t relnum,
1964                                       const elfcpp::Rela<64, false>& rela,
1965                                       unsigned int r_type,
1966                                       const Sized_symbol<64>* gsym,
1967                                       const Symbol_value<64>* psymval,
1968                                       unsigned char* view,
1969                                       elfcpp::Elf_types<64>::Elf_Addr address,
1970                                       section_size_type view_size)
1971 {
1972   Output_segment* tls_segment = relinfo->layout->tls_segment();
1973
1974   const Sized_relobj<64, false>* object = relinfo->object;
1975   const elfcpp::Elf_Xword addend = rela.get_r_addend();
1976
1977   elfcpp::Elf_types<64>::Elf_Addr value = psymval->value(relinfo->object, 0);
1978
1979   const bool is_final = (gsym == NULL
1980                          ? !parameters->options().output_is_position_independent()
1981                          : gsym->final_value_is_known());
1982   const tls::Tls_optimization optimized_type
1983       = Target_x86_64::optimize_tls_reloc(is_final, r_type);
1984   switch (r_type)
1985     {
1986     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
1987       this->saw_tls_block_reloc_ = true;
1988       if (optimized_type == tls::TLSOPT_TO_LE)
1989         {
1990           gold_assert(tls_segment != NULL);
1991           this->tls_gd_to_le(relinfo, relnum, tls_segment,
1992                              rela, r_type, value, view,
1993                              view_size);
1994           break;
1995         }
1996       else
1997         {
1998           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
1999                                    ? GOT_TYPE_TLS_OFFSET
2000                                    : GOT_TYPE_TLS_PAIR);
2001           unsigned int got_offset;
2002           if (gsym != NULL)
2003             {
2004               gold_assert(gsym->has_got_offset(got_type));
2005               got_offset = gsym->got_offset(got_type) - target->got_size();
2006             }
2007           else
2008             {
2009               unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
2010               gold_assert(object->local_has_got_offset(r_sym, got_type));
2011               got_offset = (object->local_got_offset(r_sym, got_type)
2012                             - target->got_size());
2013             }
2014           if (optimized_type == tls::TLSOPT_TO_IE)
2015             {
2016               gold_assert(tls_segment != NULL);
2017               value = target->got_plt_section()->address() + got_offset;
2018               this->tls_gd_to_ie(relinfo, relnum, tls_segment, rela, r_type,
2019                                  value, view, address, view_size);
2020               break;
2021             }
2022           else if (optimized_type == tls::TLSOPT_NONE)
2023             {
2024               // Relocate the field with the offset of the pair of GOT
2025               // entries.
2026               value = target->got_plt_section()->address() + got_offset;
2027               Relocate_functions<64, false>::pcrela32(view, value, addend,
2028                                                       address);
2029               break;
2030             }
2031         }
2032       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
2033                              _("unsupported reloc %u"), r_type);
2034       break;
2035
2036     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
2037     case elfcpp::R_X86_64_TLSDESC_CALL:
2038       this->saw_tls_block_reloc_ = true;
2039       if (optimized_type == tls::TLSOPT_TO_LE)
2040         {
2041           gold_assert(tls_segment != NULL);
2042           this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
2043                                   rela, r_type, value, view,
2044                                   view_size);
2045           break;
2046         }
2047       else
2048         {
2049           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
2050                                    ? GOT_TYPE_TLS_OFFSET
2051                                    : GOT_TYPE_TLS_DESC);
2052           unsigned int got_offset;
2053           if (gsym != NULL)
2054             {
2055               gold_assert(gsym->has_got_offset(got_type));
2056               got_offset = gsym->got_offset(got_type) - target->got_size();
2057             }
2058           else
2059             {
2060               unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
2061               gold_assert(object->local_has_got_offset(r_sym, got_type));
2062               got_offset = (object->local_got_offset(r_sym, got_type)
2063                             - target->got_size());
2064             }
2065           if (optimized_type == tls::TLSOPT_TO_IE)
2066             {
2067               gold_assert(tls_segment != NULL);
2068               value = target->got_plt_section()->address() + got_offset;
2069               this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment,
2070                                       rela, r_type, value, view, address,
2071                                       view_size);
2072               break;
2073             }
2074           else if (optimized_type == tls::TLSOPT_NONE)
2075             {
2076               if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
2077                 {
2078                   // Relocate the field with the offset of the pair of GOT
2079                   // entries.
2080                   value = target->got_plt_section()->address() + got_offset;
2081                   Relocate_functions<64, false>::pcrela32(view, value, addend,
2082                                                           address);
2083                 }
2084               break;
2085             }
2086         }
2087       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
2088                              _("unsupported reloc %u"), r_type);
2089       break;
2090
2091     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
2092       this->saw_tls_block_reloc_ = true;
2093       if (optimized_type == tls::TLSOPT_TO_LE)
2094         {
2095           gold_assert(tls_segment != NULL);
2096           this->tls_ld_to_le(relinfo, relnum, tls_segment, rela, r_type,
2097                              value, view, view_size);
2098           break;
2099         }
2100       else if (optimized_type == tls::TLSOPT_NONE)
2101         {
2102           // Relocate the field with the offset of the GOT entry for
2103           // the module index.
2104           unsigned int got_offset;
2105           got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
2106                         - target->got_size());
2107           value = target->got_plt_section()->address() + got_offset;
2108           Relocate_functions<64, false>::pcrela32(view, value, addend,
2109                                                   address);
2110           break;
2111         }
2112       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
2113                              _("unsupported reloc %u"), r_type);
2114       break;
2115
2116     case elfcpp::R_X86_64_DTPOFF32:
2117       if (optimized_type == tls::TLSOPT_TO_LE)
2118         {
2119           // This relocation type is used in debugging information.
2120           // In that case we need to not optimize the value.  If we
2121           // haven't seen a TLSLD reloc, then we assume we should not
2122           // optimize this reloc.
2123           if (this->saw_tls_block_reloc_)
2124             {
2125               gold_assert(tls_segment != NULL);
2126               value -= tls_segment->memsz();
2127             }
2128         }
2129       Relocate_functions<64, false>::rela32(view, value, addend);
2130       break;
2131
2132     case elfcpp::R_X86_64_DTPOFF64:
2133       if (optimized_type == tls::TLSOPT_TO_LE)
2134         {
2135           // See R_X86_64_DTPOFF32, just above, for why we test this.
2136           if (this->saw_tls_block_reloc_)
2137             {
2138               gold_assert(tls_segment != NULL);
2139               value -= tls_segment->memsz();
2140             }
2141         }
2142       Relocate_functions<64, false>::rela64(view, value, addend);
2143       break;
2144
2145     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
2146       if (optimized_type == tls::TLSOPT_TO_LE)
2147         {
2148           gold_assert(tls_segment != NULL);
2149           Target_x86_64::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
2150                                                 rela, r_type, value, view,
2151                                                 view_size);
2152           break;
2153         }
2154       else if (optimized_type == tls::TLSOPT_NONE)
2155         {
2156           // Relocate the field with the offset of the GOT entry for
2157           // the tp-relative offset of the symbol.
2158           unsigned int got_offset;
2159           if (gsym != NULL)
2160             {
2161               gold_assert(gsym->has_got_offset(GOT_TYPE_TLS_OFFSET));
2162               got_offset = (gsym->got_offset(GOT_TYPE_TLS_OFFSET)
2163                             - target->got_size());
2164             }
2165           else
2166             {
2167               unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
2168               gold_assert(object->local_has_got_offset(r_sym,
2169                                                        GOT_TYPE_TLS_OFFSET));
2170               got_offset = (object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET)
2171                             - target->got_size());
2172             }
2173           value = target->got_plt_section()->address() + got_offset;
2174           Relocate_functions<64, false>::pcrela32(view, value, addend, address);
2175           break;
2176         }
2177       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
2178                              _("unsupported reloc type %u"),
2179                              r_type);
2180       break;
2181
2182     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
2183       value -= tls_segment->memsz();
2184       Relocate_functions<64, false>::rela32(view, value, addend);
2185       break;
2186     }
2187 }
2188
2189 // Do a relocation in which we convert a TLS General-Dynamic to an
2190 // Initial-Exec.
2191
2192 inline void
2193 Target_x86_64::Relocate::tls_gd_to_ie(const Relocate_info<64, false>* relinfo,
2194                                       size_t relnum,
2195                                       Output_segment*,
2196                                       const elfcpp::Rela<64, false>& rela,
2197                                       unsigned int,
2198                                       elfcpp::Elf_types<64>::Elf_Addr value,
2199                                       unsigned char* view,
2200                                       elfcpp::Elf_types<64>::Elf_Addr address,
2201                                       section_size_type view_size)
2202 {
2203   // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
2204   // .word 0x6666; rex64; call __tls_get_addr
2205   // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
2206
2207   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -4);
2208   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
2209
2210   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2211                  (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
2212   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2213                  (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0));
2214
2215   memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0", 16);
2216
2217   const elfcpp::Elf_Xword addend = rela.get_r_addend();
2218   Relocate_functions<64, false>::pcrela32(view + 8, value, addend - 8, address);
2219
2220   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2221   // We can skip it.
2222   this->skip_call_tls_get_addr_ = true;
2223 }
2224
2225 // Do a relocation in which we convert a TLS General-Dynamic to a
2226 // Local-Exec.
2227
2228 inline void
2229 Target_x86_64::Relocate::tls_gd_to_le(const Relocate_info<64, false>* relinfo,
2230                                       size_t relnum,
2231                                       Output_segment* tls_segment,
2232                                       const elfcpp::Rela<64, false>& rela,
2233                                       unsigned int,
2234                                       elfcpp::Elf_types<64>::Elf_Addr value,
2235                                       unsigned char* view,
2236                                       section_size_type view_size)
2237 {
2238   // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
2239   // .word 0x6666; rex64; call __tls_get_addr
2240   // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
2241
2242   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -4);
2243   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
2244
2245   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2246                  (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
2247   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2248                  (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0));
2249
2250   memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0", 16);
2251
2252   value -= tls_segment->memsz();
2253   Relocate_functions<64, false>::rela32(view + 8, value, 0);
2254
2255   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2256   // We can skip it.
2257   this->skip_call_tls_get_addr_ = true;
2258 }
2259
2260 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
2261
2262 inline void
2263 Target_x86_64::Relocate::tls_desc_gd_to_ie(
2264     const Relocate_info<64, false>* relinfo,
2265     size_t relnum,
2266     Output_segment*,
2267     const elfcpp::Rela<64, false>& rela,
2268     unsigned int r_type,
2269     elfcpp::Elf_types<64>::Elf_Addr value,
2270     unsigned char* view,
2271     elfcpp::Elf_types<64>::Elf_Addr address,
2272     section_size_type view_size)
2273 {
2274   if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
2275     {
2276       // leaq foo@tlsdesc(%rip), %rax
2277       // ==> movq foo@gottpoff(%rip), %rax
2278       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
2279       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
2280       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2281                      view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05);
2282       view[-2] = 0x8b;
2283       const elfcpp::Elf_Xword addend = rela.get_r_addend();
2284       Relocate_functions<64, false>::pcrela32(view, value, addend, address);
2285     }
2286   else
2287     {
2288       // call *foo@tlscall(%rax)
2289       // ==> nop; nop
2290       gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
2291       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
2292       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2293                      view[0] == 0xff && view[1] == 0x10);
2294       view[0] = 0x66;
2295       view[1] = 0x90;
2296     }
2297 }
2298
2299 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
2300
2301 inline void
2302 Target_x86_64::Relocate::tls_desc_gd_to_le(
2303     const Relocate_info<64, false>* relinfo,
2304     size_t relnum,
2305     Output_segment* tls_segment,
2306     const elfcpp::Rela<64, false>& rela,
2307     unsigned int r_type,
2308     elfcpp::Elf_types<64>::Elf_Addr value,
2309     unsigned char* view,
2310     section_size_type view_size)
2311 {
2312   if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
2313     {
2314       // leaq foo@tlsdesc(%rip), %rax
2315       // ==> movq foo@tpoff, %rax
2316       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
2317       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
2318       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2319                      view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05);
2320       view[-2] = 0xc7;
2321       view[-1] = 0xc0;
2322       value -= tls_segment->memsz();
2323       Relocate_functions<64, false>::rela32(view, value, 0);
2324     }
2325   else
2326     {
2327       // call *foo@tlscall(%rax)
2328       // ==> nop; nop
2329       gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
2330       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
2331       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2332                      view[0] == 0xff && view[1] == 0x10);
2333       view[0] = 0x66;
2334       view[1] = 0x90;
2335     }
2336 }
2337
2338 inline void
2339 Target_x86_64::Relocate::tls_ld_to_le(const Relocate_info<64, false>* relinfo,
2340                                       size_t relnum,
2341                                       Output_segment*,
2342                                       const elfcpp::Rela<64, false>& rela,
2343                                       unsigned int,
2344                                       elfcpp::Elf_types<64>::Elf_Addr,
2345                                       unsigned char* view,
2346                                       section_size_type view_size)
2347 {
2348   // leaq foo@tlsld(%rip),%rdi; call __tls_get_addr@plt;
2349   // ... leq foo@dtpoff(%rax),%reg
2350   // ==> .word 0x6666; .byte 0x66; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
2351
2352   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
2353   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 9);
2354
2355   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2356                  view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x3d);
2357
2358   tls::check_tls(relinfo, relnum, rela.get_r_offset(), view[4] == 0xe8);
2359
2360   memcpy(view - 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12);
2361
2362   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2363   // We can skip it.
2364   this->skip_call_tls_get_addr_ = true;
2365 }
2366
2367 // Do a relocation in which we convert a TLS Initial-Exec to a
2368 // Local-Exec.
2369
2370 inline void
2371 Target_x86_64::Relocate::tls_ie_to_le(const Relocate_info<64, false>* relinfo,
2372                                       size_t relnum,
2373                                       Output_segment* tls_segment,
2374                                       const elfcpp::Rela<64, false>& rela,
2375                                       unsigned int,
2376                                       elfcpp::Elf_types<64>::Elf_Addr value,
2377                                       unsigned char* view,
2378                                       section_size_type view_size)
2379 {
2380   // We need to examine the opcodes to figure out which instruction we
2381   // are looking at.
2382
2383   // movq foo@gottpoff(%rip),%reg  ==>  movq $YY,%reg
2384   // addq foo@gottpoff(%rip),%reg  ==>  addq $YY,%reg
2385
2386   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
2387   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
2388
2389   unsigned char op1 = view[-3];
2390   unsigned char op2 = view[-2];
2391   unsigned char op3 = view[-1];
2392   unsigned char reg = op3 >> 3;
2393
2394   if (op2 == 0x8b)
2395     {
2396       // movq
2397       if (op1 == 0x4c)
2398         view[-3] = 0x49;
2399       view[-2] = 0xc7;
2400       view[-1] = 0xc0 | reg;
2401     }
2402   else if (reg == 4)
2403     {
2404       // Special handling for %rsp.
2405       if (op1 == 0x4c)
2406         view[-3] = 0x49;
2407       view[-2] = 0x81;
2408       view[-1] = 0xc0 | reg;
2409     }
2410   else
2411     {
2412       // addq
2413       if (op1 == 0x4c)
2414         view[-3] = 0x4d;
2415       view[-2] = 0x8d;
2416       view[-1] = 0x80 | reg | (reg << 3);
2417     }
2418
2419   value -= tls_segment->memsz();
2420   Relocate_functions<64, false>::rela32(view, value, 0);
2421 }
2422
2423 // Relocate section data.
2424
2425 void
2426 Target_x86_64::relocate_section(
2427     const Relocate_info<64, false>* relinfo,
2428     unsigned int sh_type,
2429     const unsigned char* prelocs,
2430     size_t reloc_count,
2431     Output_section* output_section,
2432     bool needs_special_offset_handling,
2433     unsigned char* view,
2434     elfcpp::Elf_types<64>::Elf_Addr address,
2435     section_size_type view_size,
2436     const Reloc_symbol_changes* reloc_symbol_changes)
2437 {
2438   gold_assert(sh_type == elfcpp::SHT_RELA);
2439
2440   gold::relocate_section<64, false, Target_x86_64, elfcpp::SHT_RELA,
2441                          Target_x86_64::Relocate>(
2442     relinfo,
2443     this,
2444     prelocs,
2445     reloc_count,
2446     output_section,
2447     needs_special_offset_handling,
2448     view,
2449     address,
2450     view_size,
2451     reloc_symbol_changes);
2452 }
2453
2454 // Return the size of a relocation while scanning during a relocatable
2455 // link.
2456
2457 unsigned int
2458 Target_x86_64::Relocatable_size_for_reloc::get_size_for_reloc(
2459     unsigned int r_type,
2460     Relobj* object)
2461 {
2462   switch (r_type)
2463     {
2464     case elfcpp::R_X86_64_NONE:
2465     case elfcpp::R_386_GNU_VTINHERIT:
2466     case elfcpp::R_386_GNU_VTENTRY:
2467     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
2468     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
2469     case elfcpp::R_X86_64_TLSDESC_CALL:
2470     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
2471     case elfcpp::R_X86_64_DTPOFF32:
2472     case elfcpp::R_X86_64_DTPOFF64:
2473     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
2474     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
2475       return 0;
2476
2477     case elfcpp::R_X86_64_64:
2478     case elfcpp::R_X86_64_PC64:
2479     case elfcpp::R_X86_64_GOTOFF64:
2480     case elfcpp::R_X86_64_GOTPC64:
2481     case elfcpp::R_X86_64_PLTOFF64:
2482     case elfcpp::R_X86_64_GOT64:
2483     case elfcpp::R_X86_64_GOTPCREL64:
2484     case elfcpp::R_X86_64_GOTPCREL:
2485     case elfcpp::R_X86_64_GOTPLT64:
2486       return 8;
2487
2488     case elfcpp::R_X86_64_32:
2489     case elfcpp::R_X86_64_32S:
2490     case elfcpp::R_X86_64_PC32:
2491     case elfcpp::R_X86_64_PLT32:
2492     case elfcpp::R_X86_64_GOTPC32:
2493     case elfcpp::R_X86_64_GOT32:
2494       return 4;
2495
2496     case elfcpp::R_X86_64_16:
2497     case elfcpp::R_X86_64_PC16:
2498       return 2;
2499
2500     case elfcpp::R_X86_64_8:
2501     case elfcpp::R_X86_64_PC8:
2502       return 1;
2503
2504     case elfcpp::R_X86_64_COPY:
2505     case elfcpp::R_X86_64_GLOB_DAT:
2506     case elfcpp::R_X86_64_JUMP_SLOT:
2507     case elfcpp::R_X86_64_RELATIVE:
2508       // These are outstanding tls relocs, which are unexpected when linking
2509     case elfcpp::R_X86_64_TPOFF64:
2510     case elfcpp::R_X86_64_DTPMOD64:
2511     case elfcpp::R_X86_64_TLSDESC:
2512       object->error(_("unexpected reloc %u in object file"), r_type);
2513       return 0;
2514
2515     case elfcpp::R_X86_64_SIZE32:
2516     case elfcpp::R_X86_64_SIZE64:
2517     default:
2518       object->error(_("unsupported reloc %u against local symbol"), r_type);
2519       return 0;
2520     }
2521 }
2522
2523 // Scan the relocs during a relocatable link.
2524
2525 void
2526 Target_x86_64::scan_relocatable_relocs(Symbol_table* symtab,
2527                                        Layout* layout,
2528                                        Sized_relobj<64, false>* object,
2529                                        unsigned int data_shndx,
2530                                        unsigned int sh_type,
2531                                        const unsigned char* prelocs,
2532                                        size_t reloc_count,
2533                                        Output_section* output_section,
2534                                        bool needs_special_offset_handling,
2535                                        size_t local_symbol_count,
2536                                        const unsigned char* plocal_symbols,
2537                                        Relocatable_relocs* rr)
2538 {
2539   gold_assert(sh_type == elfcpp::SHT_RELA);
2540
2541   typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_RELA,
2542     Relocatable_size_for_reloc> Scan_relocatable_relocs;
2543
2544   gold::scan_relocatable_relocs<64, false, elfcpp::SHT_RELA,
2545       Scan_relocatable_relocs>(
2546     symtab,
2547     layout,
2548     object,
2549     data_shndx,
2550     prelocs,
2551     reloc_count,
2552     output_section,
2553     needs_special_offset_handling,
2554     local_symbol_count,
2555     plocal_symbols,
2556     rr);
2557 }
2558
2559 // Relocate a section during a relocatable link.
2560
2561 void
2562 Target_x86_64::relocate_for_relocatable(
2563     const Relocate_info<64, false>* relinfo,
2564     unsigned int sh_type,
2565     const unsigned char* prelocs,
2566     size_t reloc_count,
2567     Output_section* output_section,
2568     off_t offset_in_output_section,
2569     const Relocatable_relocs* rr,
2570     unsigned char* view,
2571     elfcpp::Elf_types<64>::Elf_Addr view_address,
2572     section_size_type view_size,
2573     unsigned char* reloc_view,
2574     section_size_type reloc_view_size)
2575 {
2576   gold_assert(sh_type == elfcpp::SHT_RELA);
2577
2578   gold::relocate_for_relocatable<64, false, elfcpp::SHT_RELA>(
2579     relinfo,
2580     prelocs,
2581     reloc_count,
2582     output_section,
2583     offset_in_output_section,
2584     rr,
2585     view,
2586     view_address,
2587     view_size,
2588     reloc_view,
2589     reloc_view_size);
2590 }
2591
2592 // Return the value to use for a dynamic which requires special
2593 // treatment.  This is how we support equality comparisons of function
2594 // pointers across shared library boundaries, as described in the
2595 // processor specific ABI supplement.
2596
2597 uint64_t
2598 Target_x86_64::do_dynsym_value(const Symbol* gsym) const
2599 {
2600   gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
2601   return this->plt_section()->address() + gsym->plt_offset();
2602 }
2603
2604 // Return a string used to fill a code section with nops to take up
2605 // the specified length.
2606
2607 std::string
2608 Target_x86_64::do_code_fill(section_size_type length) const
2609 {
2610   if (length >= 16)
2611     {
2612       // Build a jmpq instruction to skip over the bytes.
2613       unsigned char jmp[5];
2614       jmp[0] = 0xe9;
2615       elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
2616       return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
2617               + std::string(length - 5, '\0'));
2618     }
2619
2620   // Nop sequences of various lengths.
2621   const char nop1[1] = { 0x90 };                   // nop
2622   const char nop2[2] = { 0x66, 0x90 };             // xchg %ax %ax
2623   const char nop3[3] = { 0x0f, 0x1f, 0x00 };       // nop (%rax)
2624   const char nop4[4] = { 0x0f, 0x1f, 0x40, 0x00};  // nop 0(%rax)
2625   const char nop5[5] = { 0x0f, 0x1f, 0x44, 0x00,   // nop 0(%rax,%rax,1)
2626                          0x00 };
2627   const char nop6[6] = { 0x66, 0x0f, 0x1f, 0x44,   // nopw 0(%rax,%rax,1)
2628                          0x00, 0x00 };
2629   const char nop7[7] = { 0x0f, 0x1f, 0x80, 0x00,   // nopl 0L(%rax)
2630                          0x00, 0x00, 0x00 };
2631   const char nop8[8] = { 0x0f, 0x1f, 0x84, 0x00,   // nopl 0L(%rax,%rax,1)
2632                          0x00, 0x00, 0x00, 0x00 };
2633   const char nop9[9] = { 0x66, 0x0f, 0x1f, 0x84,   // nopw 0L(%rax,%rax,1)
2634                          0x00, 0x00, 0x00, 0x00,
2635                          0x00 };
2636   const char nop10[10] = { 0x66, 0x2e, 0x0f, 0x1f, // nopw %cs:0L(%rax,%rax,1)
2637                            0x84, 0x00, 0x00, 0x00,
2638                            0x00, 0x00 };
2639   const char nop11[11] = { 0x66, 0x66, 0x2e, 0x0f, // data16
2640                            0x1f, 0x84, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
2641                            0x00, 0x00, 0x00 };
2642   const char nop12[12] = { 0x66, 0x66, 0x66, 0x2e, // data16; data16
2643                            0x0f, 0x1f, 0x84, 0x00, // nopw %cs:0L(%rax,%rax,1)
2644                            0x00, 0x00, 0x00, 0x00 };
2645   const char nop13[13] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
2646                            0x2e, 0x0f, 0x1f, 0x84, // nopw %cs:0L(%rax,%rax,1)
2647                            0x00, 0x00, 0x00, 0x00,
2648                            0x00 };
2649   const char nop14[14] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
2650                            0x66, 0x2e, 0x0f, 0x1f, // data16
2651                            0x84, 0x00, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
2652                            0x00, 0x00 };
2653   const char nop15[15] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
2654                            0x66, 0x66, 0x2e, 0x0f, // data16; data16
2655                            0x1f, 0x84, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
2656                            0x00, 0x00, 0x00 };
2657
2658   const char* nops[16] = {
2659     NULL,
2660     nop1, nop2, nop3, nop4, nop5, nop6, nop7,
2661     nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
2662   };
2663
2664   return std::string(nops[length], length);
2665 }
2666
2667 // FNOFFSET in section SHNDX in OBJECT is the start of a function
2668 // compiled with -fstack-split.  The function calls non-stack-split
2669 // code.  We have to change the function so that it always ensures
2670 // that it has enough stack space to run some random function.
2671
2672 void
2673 Target_x86_64::do_calls_non_split(Relobj* object, unsigned int shndx,
2674                                   section_offset_type fnoffset,
2675                                   section_size_type fnsize,
2676                                   unsigned char* view,
2677                                   section_size_type view_size,
2678                                   std::string* from,
2679                                   std::string* to) const
2680 {
2681   // The function starts with a comparison of the stack pointer and a
2682   // field in the TCB.  This is followed by a jump.
2683
2684   // cmp %fs:NN,%rsp
2685   if (this->match_view(view, view_size, fnoffset, "\x64\x48\x3b\x24\x25", 5)
2686       && fnsize > 9)
2687     {
2688       // We will call __morestack if the carry flag is set after this
2689       // comparison.  We turn the comparison into an stc instruction
2690       // and some nops.
2691       view[fnoffset] = '\xf9';
2692       this->set_view_to_nop(view, view_size, fnoffset + 1, 8);
2693     }
2694   // lea NN(%rsp),%r10
2695   else if (this->match_view(view, view_size, fnoffset, "\x4c\x8d\x94\x24", 4)
2696            && fnsize > 8)
2697     {
2698       // This is loading an offset from the stack pointer for a
2699       // comparison.  The offset is negative, so we decrease the
2700       // offset by the amount of space we need for the stack.  This
2701       // means we will avoid calling __morestack if there happens to
2702       // be plenty of space on the stack already.
2703       unsigned char* pval = view + fnoffset + 4;
2704       uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
2705       val -= parameters->options().split_stack_adjust_size();
2706       elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
2707     }
2708   else
2709     {
2710       if (!object->has_no_split_stack())
2711         object->error(_("failed to match split-stack sequence at "
2712                         "section %u offset %0zx"),
2713                       shndx, static_cast<size_t>(fnoffset));
2714       return;
2715     }
2716
2717   // We have to change the function so that it calls
2718   // __morestack_non_split instead of __morestack.  The former will
2719   // allocate additional stack space.
2720   *from = "__morestack";
2721   *to = "__morestack_non_split";
2722 }
2723
2724 // The selector for x86_64 object files.
2725
2726 class Target_selector_x86_64 : public Target_selector_freebsd
2727 {
2728 public:
2729   Target_selector_x86_64()
2730     : Target_selector_freebsd(elfcpp::EM_X86_64, 64, false, "elf64-x86-64",
2731                               "elf64-x86-64-freebsd")
2732   { }
2733
2734   Target*
2735   do_instantiate_target()
2736   { return new Target_x86_64(); }
2737
2738 };
2739
2740 Target_selector_x86_64 target_selector_x86_64;
2741
2742 } // End anonymous namespace.