gold/x86_64.cc

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