gold/x86_64.cc

   1 // x86_64.cc -- x86_64 target support for gold.
   2
   3 // Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
   4 // Written by Ian Lance Taylor <iant@google.com>.
   5
   6 // This file is part of gold.
   7
   8 // This program is free software; you can redistribute it and/or modify
   9 // it under the terms of the GNU General Public License as published by
  10 // the Free Software Foundation; either version 3 of the License, or
  11 // (at your option) any later version.
  12
  13 // This program is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17
  18 // You should have received a copy of the GNU General Public License
  19 // along with this program; if not, write to the Free Software
  20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  21 // MA 02110-1301, USA.
  22
  23 #include "gold.h"
  24
  25 #include <cstring>
  26
  27 #include "elfcpp.h"
  28 #include "parameters.h"
  29 #include "reloc.h"
  30 #include "x86_64.h"
  31 #include "object.h"
  32 #include "symtab.h"
  33 #include "layout.h"
  34 #include "output.h"
  35 #include "copy-relocs.h"
  36 #include "target.h"
  37 #include "target-reloc.h"
  38 #include "target-select.h"
  39 #include "tls.h"
  40 #include "freebsd.h"
  41 #include "gc.h"
  42
  43 namespace
  44 {
  45
  46 using namespace gold;
  47
  48 class Output_data_plt_x86_64;
  49
  50 // The x86_64 target class.
  51 // See the ABI at
  52 //   http://www.x86-64.org/documentation/abi.pdf
  53 // TLS info comes from
  54 //   http://people.redhat.com/drepper/tls.pdf
  55 //   http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
  56
  57 class Target_x86_64 : public Target_freebsd<64, false>
  58 {
  59  public:
  60   // In the x86_64 ABI (p 68), it says "The AMD64 ABI architectures
  61   // uses only Elf64_Rela relocation entries with explicit addends."
  62   typedef Output_data_reloc<elfcpp::SHT_RELA, true, 64, false> Reloc_section;
  63
  64   Target_x86_64()
  65     : Target_freebsd<64, false>(&x86_64_info),
  66       got_(NULL), plt_(NULL), got_plt_(NULL), global_offset_table_(NULL),
  67       rela_dyn_(NULL), copy_relocs_(elfcpp::R_X86_64_COPY), dynbss_(NULL),
  68       got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
  69   { }
  70
  71   // Hook for a new output section.
  72   void
  73   do_new_output_section(Output_section*) const;
  74
  75   // Scan the relocations to look for symbol adjustments.
  76   void
  77   gc_process_relocs(Symbol_table* symtab,
  78                     Layout* layout,
  79                     Sized_relobj<64, false>* object,
  80                     unsigned int data_shndx,
  81                     unsigned int sh_type,
  82                     const unsigned char* prelocs,
  83                     size_t reloc_count,
  84                     Output_section* output_section,
  85                     bool needs_special_offset_handling,
  86                     size_t local_symbol_count,
  87                     const unsigned char* plocal_symbols);
  88
  89   // Scan the relocations to look for symbol adjustments.
  90   void
  91   scan_relocs(Symbol_table* symtab,
  92               Layout* layout,
  93               Sized_relobj<64, false>* object,
  94               unsigned int data_shndx,
  95               unsigned int sh_type,
  96               const unsigned char* prelocs,
  97               size_t reloc_count,
  98               Output_section* output_section,
  99               bool needs_special_offset_handling,
 100               size_t local_symbol_count,
 101               const unsigned char* plocal_symbols);
 102
 103   // Finalize the sections.
 104   void
 105   do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
 106
 107   // Return the value to use for a dynamic which requires special
 108   // treatment.
 109   uint64_t
 110   do_dynsym_value(const Symbol*) const;
 111
 112   // Relocate a section.
 113   void
 114   relocate_section(const Relocate_info<64, false>*,
 115                    unsigned int sh_type,
 116                    const unsigned char* prelocs,
 117                    size_t reloc_count,
 118                    Output_section* output_section,
 119                    bool needs_special_offset_handling,
 120                    unsigned char* view,
 121                    elfcpp::Elf_types<64>::Elf_Addr view_address,
 122                    section_size_type view_size,
 123                    const Reloc_symbol_changes*);
 124
 125   // Scan the relocs during a relocatable link.
 126   void
 127   scan_relocatable_relocs(Symbol_table* symtab,
 128                           Layout* layout,
 129                           Sized_relobj<64, false>* object,
 130                           unsigned int data_shndx,
 131                           unsigned int sh_type,
 132                           const unsigned char* prelocs,
 133                           size_t reloc_count,
 134                           Output_section* output_section,
 135                           bool needs_special_offset_handling,
 136                           size_t local_symbol_count,
 137                           const unsigned char* plocal_symbols,
 138                           Relocatable_relocs*);
 139
 140   // Relocate a section during a relocatable link.
 141   void
 142   relocate_for_relocatable(const Relocate_info<64, false>*,
 143                            unsigned int sh_type,
 144                            const unsigned char* prelocs,
 145                            size_t reloc_count,
 146                            Output_section* output_section,
 147                            off_t offset_in_output_section,
 148                            const Relocatable_relocs*,
 149                            unsigned char* view,
 150                            elfcpp::Elf_types<64>::Elf_Addr view_address,
 151                            section_size_type view_size,
 152                            unsigned char* reloc_view,
 153                            section_size_type reloc_view_size);
 154
 155   // Return a string used to fill a code section with nops.
 156   std::string
 157   do_code_fill(section_size_type length) const;
 158
 159   // Return whether SYM is defined by the ABI.
 160   bool
 161   do_is_defined_by_abi(const Symbol* sym) const
 162   { return strcmp(sym->name(), "__tls_get_addr") == 0; }
 163
 164   // Adjust -fstack-split code which calls non-stack-split code.
 165   void
 166   do_calls_non_split(Relobj* object, unsigned int shndx,
 167                      section_offset_type fnoffset, section_size_type fnsize,
 168                      unsigned char* view, section_size_type view_size,
 169                      std::string* from, std::string* to) const;
 170
 171   // Return the size of the GOT section.
 172   section_size_type
 173   got_size()
 174   {
 175     gold_assert(this->got_ != NULL);
 176     return this->got_->data_size();
 177   }
 178
 179  private:
 180   // The class which scans relocations.
 181   class Scan
 182   {
 183   public:
 184     Scan()
 185       : issued_non_pic_error_(false)
 186     { }
 187
 188     inline void
 189     local(Symbol_table* symtab, Layout* layout, Target_x86_64* target,
 190           Sized_relobj<64, false>* object,
 191           unsigned int data_shndx,
 192           Output_section* output_section,
 193           const elfcpp::Rela<64, false>& reloc, unsigned int r_type,
 194           const elfcpp::Sym<64, false>& lsym);
 195
 196     inline void
 197     global(Symbol_table* symtab, Layout* layout, Target_x86_64* target,
 198            Sized_relobj<64, false>* object,
 199            unsigned int data_shndx,
 200            Output_section* output_section,
 201            const elfcpp::Rela<64, false>& reloc, unsigned int r_type,
 202            Symbol* gsym);
 203
 204   private:
 205     static void
 206     unsupported_reloc_local(Sized_relobj<64, false>*, unsigned int r_type);
 207
 208     static void
 209     unsupported_reloc_global(Sized_relobj<64, false>*, unsigned int r_type,
 210                              Symbol*);
 211
 212     void
 213     check_non_pic(Relobj*, unsigned int r_type);
 214
 215     // Whether we have issued an error about a non-PIC compilation.
 216     bool issued_non_pic_error_;
 217   };
 218
 219   // The class which implements relocation.
 220   class Relocate
 221   {
 222    public:
 223     Relocate()
 224       : skip_call_tls_get_addr_(false), saw_tls_block_reloc_(false)
 225     { }
 226
 227     ~Relocate()
 228     {
 229       if (this->skip_call_tls_get_addr_)
 230         {
 231           // FIXME: This needs to specify the location somehow.
 232           gold_error(_("missing expected TLS relocation"));
 233         }
 234     }
 235
 236     // Do a relocation.  Return false if the caller should not issue
 237     // any warnings about this relocation.
 238     inline bool
 239     relocate(const Relocate_info<64, false>*, Target_x86_64*, Output_section*,
 240              size_t relnum, const elfcpp::Rela<64, false>&,
 241              unsigned int r_type, const Sized_symbol<64>*,
 242              const Symbol_value<64>*,
 243              unsigned char*, elfcpp::Elf_types<64>::Elf_Addr,
 244              section_size_type);
 245
 246    private:
 247     // Do a TLS relocation.
 248     inline void
 249     relocate_tls(const Relocate_info<64, false>*, Target_x86_64*,
 250                  size_t relnum, const elfcpp::Rela<64, false>&,
 251                  unsigned int r_type, const Sized_symbol<64>*,
 252                  const Symbol_value<64>*,
 253                  unsigned char*, elfcpp::Elf_types<64>::Elf_Addr,
 254                  section_size_type);
 255
 256     // Do a TLS General-Dynamic to Initial-Exec transition.
 257     inline void
 258     tls_gd_to_ie(const Relocate_info<64, false>*, size_t relnum,
 259                  Output_segment* tls_segment,
 260                  const elfcpp::Rela<64, false>&, unsigned int r_type,
 261                  elfcpp::Elf_types<64>::Elf_Addr value,
 262                  unsigned char* view,
 263                  elfcpp::Elf_types<64>::Elf_Addr,
 264                  section_size_type view_size);
 265
 266     // Do a TLS General-Dynamic to Local-Exec transition.
 267     inline void
 268     tls_gd_to_le(const Relocate_info<64, false>*, size_t relnum,
 269                  Output_segment* tls_segment,
 270                  const elfcpp::Rela<64, false>&, unsigned int r_type,
 271                  elfcpp::Elf_types<64>::Elf_Addr value,
 272                  unsigned char* view,
 273                  section_size_type view_size);
 274
 275     // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
 276     inline void
 277     tls_desc_gd_to_ie(const Relocate_info<64, false>*, size_t relnum,
 278                       Output_segment* tls_segment,
 279                       const elfcpp::Rela<64, false>&, unsigned int r_type,
 280                       elfcpp::Elf_types<64>::Elf_Addr value,
 281                       unsigned char* view,
 282                       elfcpp::Elf_types<64>::Elf_Addr,
 283                       section_size_type view_size);
 284
 285     // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
 286     inline void
 287     tls_desc_gd_to_le(const Relocate_info<64, false>*, size_t relnum,
 288                       Output_segment* tls_segment,
 289                       const elfcpp::Rela<64, false>&, unsigned int r_type,
 290                       elfcpp::Elf_types<64>::Elf_Addr value,
 291                       unsigned char* view,
 292                       section_size_type view_size);
 293
 294     // Do a TLS Local-Dynamic to Local-Exec transition.
 295     inline void
 296     tls_ld_to_le(const Relocate_info<64, false>*, size_t relnum,
 297                  Output_segment* tls_segment,
 298                  const elfcpp::Rela<64, false>&, unsigned int r_type,
 299                  elfcpp::Elf_types<64>::Elf_Addr value,
 300                  unsigned char* view,
 301                  section_size_type view_size);
 302
 303     // Do a TLS Initial-Exec to Local-Exec transition.
 304     static inline void
 305     tls_ie_to_le(const Relocate_info<64, false>*, size_t relnum,
 306                  Output_segment* tls_segment,
 307                  const elfcpp::Rela<64, false>&, unsigned int r_type,
 308                  elfcpp::Elf_types<64>::Elf_Addr value,
 309                  unsigned char* view,
 310                  section_size_type view_size);
 311
 312     // This is set if we should skip the next reloc, which should be a
 313     // PLT32 reloc against ___tls_get_addr.
 314     bool skip_call_tls_get_addr_;
 315
 316     // This is set if we see a relocation which could load the address
 317     // of the TLS block.  Whether we see such a relocation determines
 318     // how we handle the R_X86_64_DTPOFF32 relocation, which is used
 319     // in debugging sections.
 320     bool saw_tls_block_reloc_;
 321   };
 322
 323   // A class which returns the size required for a relocation type,
 324   // used while scanning relocs during a relocatable link.
 325   class Relocatable_size_for_reloc
 326   {
 327    public:
 328     unsigned int
 329     get_size_for_reloc(unsigned int, Relobj*);
 330   };
 331
 332   // Adjust TLS relocation type based on the options and whether this
 333   // is a local symbol.
 334   static tls::Tls_optimization
 335   optimize_tls_reloc(bool is_final, int r_type);
 336
 337   // Get the GOT section, creating it if necessary.
 338   Output_data_got<64, false>*
 339   got_section(Symbol_table*, Layout*);
 340
 341   // Get the GOT PLT section.
 342   Output_data_space*
 343   got_plt_section() const
 344   {
 345     gold_assert(this->got_plt_ != NULL);
 346     return this->got_plt_;
 347   }
 348
 349   // Create the PLT section.
 350   void
 351   make_plt_section(Symbol_table* symtab, Layout* layout);
 352
 353   // Create a PLT entry for a global symbol.
 354   void
 355   make_plt_entry(Symbol_table*, Layout*, Symbol*);
 356
 357   // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
 358   void
 359   define_tls_base_symbol(Symbol_table*, Layout*);
 360
 361   // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
 362   void
 363   reserve_tlsdesc_entries(Symbol_table* symtab, Layout* layout);
 364
 365   // Create a GOT entry for the TLS module index.
 366   unsigned int
 367   got_mod_index_entry(Symbol_table* symtab, Layout* layout,
 368                       Sized_relobj<64, false>* object);
 369
 370   // Get the PLT section.
 371   Output_data_plt_x86_64*
 372   plt_section() const
 373   {
 374     gold_assert(this->plt_ != NULL);
 375     return this->plt_;
 376   }
 377
 378   // Get the dynamic reloc section, creating it if necessary.
 379   Reloc_section*
 380   rela_dyn_section(Layout*);
 381
 382   // Add a potential copy relocation.
 383   void
 384   copy_reloc(Symbol_table* symtab, Layout* layout,
 385              Sized_relobj<64, false>* object,
 386              unsigned int shndx, Output_section* output_section,
 387              Symbol* sym, const elfcpp::Rela<64, false>& reloc)
 388   {
 389     this->copy_relocs_.copy_reloc(symtab, layout,
 390                                   symtab->get_sized_symbol<64>(sym),
 391                                   object, shndx, output_section,
 392                                   reloc, this->rela_dyn_section(layout));
 393   }
 394
 395   // Information about this specific target which we pass to the
 396   // general Target structure.
 397   static const Target::Target_info x86_64_info;
 398
 399   enum Got_type
 400   {
 401     GOT_TYPE_STANDARD = 0,      // GOT entry for a regular symbol
 402     GOT_TYPE_TLS_OFFSET = 1,    // GOT entry for TLS offset
 403     GOT_TYPE_TLS_PAIR = 2,      // GOT entry for TLS module/offset pair
 404     GOT_TYPE_TLS_DESC = 3       // GOT entry for TLS_DESC pair
 405   };
 406
 407   // The GOT section.
 408   Output_data_got<64, false>* got_;
 409   // The PLT section.
 410   Output_data_plt_x86_64* plt_;
 411   // The GOT PLT section.
 412   Output_data_space* got_plt_;
 413   // The _GLOBAL_OFFSET_TABLE_ symbol.
 414   Symbol* global_offset_table_;
 415   // The dynamic reloc section.
 416   Reloc_section* rela_dyn_;
 417   // Relocs saved to avoid a COPY reloc.
 418   Copy_relocs<elfcpp::SHT_RELA, 64, false> copy_relocs_;
 419   // Space for variables copied with a COPY reloc.
 420   Output_data_space* dynbss_;
 421   // Offset of the GOT entry for the TLS module index.
 422   unsigned int got_mod_index_offset_;
 423   // True if the _TLS_MODULE_BASE_ symbol has been defined.
 424   bool tls_base_symbol_defined_;
 425 };
 426
 427 const Target::Target_info Target_x86_64::x86_64_info =
 428 {
 429   64,                   // size
 430   false,                // is_big_endian
 431   elfcpp::EM_X86_64,    // machine_code
 432   false,                // has_make_symbol
 433   false,                // has_resolve
 434   true,                 // has_code_fill
 435   true,                 // is_default_stack_executable
 436   '\0',                 // wrap_char
 437   "/lib/ld64.so.1",     // program interpreter
 438   0x400000,             // default_text_segment_address
 439   0x1000,               // abi_pagesize (overridable by -z max-page-size)
 440   0x1000,               // common_pagesize (overridable by -z common-page-size)
 441   elfcpp::SHN_UNDEF,    // small_common_shndx
 442   elfcpp::SHN_X86_64_LCOMMON,   // large_common_shndx
 443   0,                    // small_common_section_flags
 444   elfcpp::SHF_X86_64_LARGE,     // large_common_section_flags
 445   NULL,                 // attributes_section
 446   NULL                  // attributes_vendor
 447 };
 448
 449 // This is called when a new output section is created.  This is where
 450 // we handle the SHF_X86_64_LARGE.
 451
 452 void
 453 Target_x86_64::do_new_output_section(Output_section *os) const
 454 {
 455   if ((os->flags() & elfcpp::SHF_X86_64_LARGE) != 0)
 456     os->set_is_large_section();
 457 }
 458
 459 // Get the GOT section, creating it if necessary.
 460
 461 Output_data_got<64, false>*
 462 Target_x86_64::got_section(Symbol_table* symtab, Layout* layout)
 463 {
 464   if (this->got_ == NULL)
 465     {
 466       gold_assert(symtab != NULL && layout != NULL);
 467
 468       this->got_ = new Output_data_got<64, false>();
 469
 470       Output_section* os;
 471       os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
 472                                            (elfcpp::SHF_ALLOC
 473                                             | elfcpp::SHF_WRITE),
 474                                            this->got_, false, true, true,
 475                                            false);
 476
 477       this->got_plt_ = new Output_data_space(8, "** GOT PLT");
 478       os = layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
 479                                            (elfcpp::SHF_ALLOC
 480                                             | elfcpp::SHF_WRITE),
 481                                            this->got_plt_, false, false,
 482                                            false, true);
 483
 484       // The first three entries are reserved.
 485       this->got_plt_->set_current_data_size(3 * 8);
 486
 487       // Those bytes can go into the relro segment.
 488       layout->increase_relro(3 * 8);
 489
 490       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
 491       this->global_offset_table_ =
 492         symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
 493                                       Symbol_table::PREDEFINED,
 494                                       this->got_plt_,
 495                                       0, 0, elfcpp::STT_OBJECT,
 496                                       elfcpp::STB_LOCAL,
 497                                       elfcpp::STV_HIDDEN, 0,
 498                                       false, false);
 499     }
 500
 501   return this->got_;
 502 }
 503
 504 // Get the dynamic reloc section, creating it if necessary.
 505
 506 Target_x86_64::Reloc_section*
 507 Target_x86_64::rela_dyn_section(Layout* layout)
 508 {
 509   if (this->rela_dyn_ == NULL)
 510     {
 511       gold_assert(layout != NULL);
 512       this->rela_dyn_ = new Reloc_section(parameters->options().combreloc());
 513       layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
 514                                       elfcpp::SHF_ALLOC, this->rela_dyn_, true,
 515                                       false, false, false);
 516     }
 517   return this->rela_dyn_;
 518 }
 519
 520 // A class to handle the PLT data.
 521
 522 class Output_data_plt_x86_64 : public Output_section_data
 523 {
 524  public:
 525   typedef Output_data_reloc<elfcpp::SHT_RELA, true, 64, false> Reloc_section;
 526
 527   Output_data_plt_x86_64(Layout*, Output_data_got<64, false>*,
 528                          Output_data_space*);
 529
 530   // Add an entry to the PLT.
 531   void
 532   add_entry(Symbol* gsym);
 533
 534   // Add the reserved TLSDESC_PLT entry to the PLT.
 535   void
 536   reserve_tlsdesc_entry(unsigned int got_offset)
 537   { this->tlsdesc_got_offset_ = got_offset; }
 538
 539   // Return true if a TLSDESC_PLT entry has been reserved.
 540   bool
 541   has_tlsdesc_entry() const
 542   { return this->tlsdesc_got_offset_ != -1U; }
 543
 544   // Return the GOT offset for the reserved TLSDESC_PLT entry.
 545   unsigned int
 546   get_tlsdesc_got_offset() const
 547   { return this->tlsdesc_got_offset_; }
 548
 549   // Return the offset of the reserved TLSDESC_PLT entry.
 550   unsigned int
 551   get_tlsdesc_plt_offset() const
 552   { return (this->count_ + 1) * plt_entry_size; }
 553
 554   // Return the .rel.plt section data.
 555   const Reloc_section*
 556   rel_plt() const
 557   { return this->rel_; }
 558
 559  protected:
 560   void
 561   do_adjust_output_section(Output_section* os);
 562
 563   // Write to a map file.
 564   void
 565   do_print_to_mapfile(Mapfile* mapfile) const
 566   { mapfile->print_output_data(this, _("** PLT")); }
 567
 568  private:
 569   // The size of an entry in the PLT.
 570   static const int plt_entry_size = 16;
 571
 572   // The first entry in the PLT.
 573   // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
 574   // procedure linkage table for both programs and shared objects."
 575   static unsigned char first_plt_entry[plt_entry_size];
 576
 577   // Other entries in the PLT for an executable.
 578   static unsigned char plt_entry[plt_entry_size];
 579
 580   // The reserved TLSDESC entry in the PLT for an executable.
 581   static unsigned char tlsdesc_plt_entry[plt_entry_size];
 582
 583   // Set the final size.
 584   void
 585   set_final_data_size();
 586
 587   // Write out the PLT data.
 588   void
 589   do_write(Output_file*);
 590
 591   // The reloc section.
 592   Reloc_section* rel_;
 593   // The .got section.
 594   Output_data_got<64, false>* got_;
 595   // The .got.plt section.
 596   Output_data_space* got_plt_;
 597   // The number of PLT entries.
 598   unsigned int count_;
 599   // Offset of the reserved TLSDESC_GOT entry when needed.
 600   unsigned int tlsdesc_got_offset_;
 601 };
 602
 603 // Create the PLT section.  The ordinary .got section is an argument,
 604 // since we need to refer to the start.  We also create our own .got
 605 // section just for PLT entries.
 606
 607 Output_data_plt_x86_64::Output_data_plt_x86_64(Layout* layout,
 608                                                Output_data_got<64, false>* got,
 609                                                Output_data_space* got_plt)
 610   : Output_section_data(8), got_(got), got_plt_(got_plt), count_(0),
 611     tlsdesc_got_offset_(-1U)
 612 {
 613   this->rel_ = new Reloc_section(false);
 614   layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
 615                                   elfcpp::SHF_ALLOC, this->rel_, true,
 616                                   false, false, false);
 617 }
 618
 619 void
 620 Output_data_plt_x86_64::do_adjust_output_section(Output_section* os)
 621 {
 622   os->set_entsize(plt_entry_size);
 623 }
 624
 625 // Add an entry to the PLT.
 626
 627 void
 628 Output_data_plt_x86_64::add_entry(Symbol* gsym)
 629 {
 630   gold_assert(!gsym->has_plt_offset());
 631
 632   // Note that when setting the PLT offset we skip the initial
 633   // reserved PLT entry.
 634   gsym->set_plt_offset((this->count_ + 1) * plt_entry_size);
 635
 636   ++this->count_;
 637
 638   section_offset_type got_offset = this->got_plt_->current_data_size();
 639
 640   // Every PLT entry needs a GOT entry which points back to the PLT
 641   // entry (this will be changed by the dynamic linker, normally
 642   // lazily when the function is called).
 643   this->got_plt_->set_current_data_size(got_offset + 8);
 644
 645   // Every PLT entry needs a reloc.
 646   gsym->set_needs_dynsym_entry();
 647   this->rel_->add_global(gsym, elfcpp::R_X86_64_JUMP_SLOT, this->got_plt_,
 648                          got_offset, 0);
 649
 650   // Note that we don't need to save the symbol.  The contents of the
 651   // PLT are independent of which symbols are used.  The symbols only
 652   // appear in the relocations.
 653 }
 654
 655 // Set the final size.
 656 void
 657 Output_data_plt_x86_64::set_final_data_size()
 658 {
 659   unsigned int count = this->count_;
 660   if (this->has_tlsdesc_entry())
 661     ++count;
 662   this->set_data_size((count + 1) * plt_entry_size);
 663 }
 664
 665 // The first entry in the PLT for an executable.
 666
 667 unsigned char Output_data_plt_x86_64::first_plt_entry[plt_entry_size] =
 668 {
 669   // From AMD64 ABI Draft 0.98, page 76
 670   0xff, 0x35,   // pushq contents of memory address
 671   0, 0, 0, 0,   // replaced with address of .got + 8
 672   0xff, 0x25,   // jmp indirect
 673   0, 0, 0, 0,   // replaced with address of .got + 16
 674   0x90, 0x90, 0x90, 0x90   // noop (x4)
 675 };
 676
 677 // Subsequent entries in the PLT for an executable.
 678
 679 unsigned char Output_data_plt_x86_64::plt_entry[plt_entry_size] =
 680 {
 681   // From AMD64 ABI Draft 0.98, page 76
 682   0xff, 0x25,   // jmpq indirect
 683   0, 0, 0, 0,   // replaced with address of symbol in .got
 684   0x68,         // pushq immediate
 685   0, 0, 0, 0,   // replaced with offset into relocation table
 686   0xe9,         // jmpq relative
 687   0, 0, 0, 0    // replaced with offset to start of .plt
 688 };
 689
 690 // The reserved TLSDESC entry in the PLT for an executable.
 691
 692 unsigned char Output_data_plt_x86_64::tlsdesc_plt_entry[plt_entry_size] =
 693 {
 694   // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
 695   // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
 696   0xff, 0x35,   // pushq x(%rip)
 697   0, 0, 0, 0,   // replaced with address of linkmap GOT entry (at PLTGOT + 8)
 698   0xff, 0x25,   // jmpq *y(%rip)
 699   0, 0, 0, 0,   // replaced with offset of reserved TLSDESC_GOT entry
 700   0x0f, 0x1f,   // nop
 701   0x40, 0
 702 };
 703
 704 // Write out the PLT.  This uses the hand-coded instructions above,
 705 // and adjusts them as needed.  This is specified by the AMD64 ABI.
 706
 707 void
 708 Output_data_plt_x86_64::do_write(Output_file* of)
 709 {
 710   const off_t offset = this->offset();
 711   const section_size_type oview_size =
 712     convert_to_section_size_type(this->data_size());
 713   unsigned char* const oview = of->get_output_view(offset, oview_size);
 714
 715   const off_t got_file_offset = this->got_plt_->offset();
 716   const section_size_type got_size =
 717     convert_to_section_size_type(this->got_plt_->data_size());
 718   unsigned char* const got_view = of->get_output_view(got_file_offset,
 719                                                       got_size);
 720
 721   unsigned char* pov = oview;
 722
 723   // The base address of the .plt section.
 724   elfcpp::Elf_types<64>::Elf_Addr plt_address = this->address();
 725   // The base address of the .got section.
 726   elfcpp::Elf_types<64>::Elf_Addr got_base = this->got_->address();
 727   // The base address of the PLT portion of the .got section,
 728   // which is where the GOT pointer will point, and where the
 729   // three reserved GOT entries are located.
 730   elfcpp::Elf_types<64>::Elf_Addr got_address = this->got_plt_->address();
 731
 732   memcpy(pov, first_plt_entry, plt_entry_size);
 733   // We do a jmp relative to the PC at the end of this instruction.
 734   elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
 735                                               (got_address + 8
 736                                                - (plt_address + 6)));
 737   elfcpp::Swap<32, false>::writeval(pov + 8,
 738                                     (got_address + 16
 739                                      - (plt_address + 12)));
 740   pov += plt_entry_size;
 741
 742   unsigned char* got_pov = got_view;
 743
 744   memset(got_pov, 0, 24);
 745   got_pov += 24;
 746
 747   unsigned int plt_offset = plt_entry_size;
 748   unsigned int got_offset = 24;
 749   const unsigned int count = this->count_;
 750   for (unsigned int plt_index = 0;
 751        plt_index < count;
 752        ++plt_index,
 753          pov += plt_entry_size,
 754          got_pov += 8,
 755          plt_offset += plt_entry_size,
 756          got_offset += 8)
 757     {
 758       // Set and adjust the PLT entry itself.
 759       memcpy(pov, plt_entry, plt_entry_size);
 760       elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
 761                                                   (got_address + got_offset
 762                                                    - (plt_address + plt_offset
 763                                                       + 6)));
 764
 765       elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_index);
 766       elfcpp::Swap<32, false>::writeval(pov + 12,
 767                                         - (plt_offset + plt_entry_size));
 768
 769       // Set the entry in the GOT.
 770       elfcpp::Swap<64, false>::writeval(got_pov, plt_address + plt_offset + 6);
 771     }
 772
 773   if (this->has_tlsdesc_entry())
 774     {
 775       // Set and adjust the reserved TLSDESC PLT entry.
 776       unsigned int tlsdesc_got_offset = this->get_tlsdesc_got_offset();
 777       memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
 778       elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
 779                                                   (got_address + 8
 780                                                    - (plt_address + plt_offset
 781                                                       + 6)));
 782       elfcpp::Swap_unaligned<32, false>::writeval(pov + 8,
 783                                                   (got_base
 784                                                    + tlsdesc_got_offset
 785                                                    - (plt_address + plt_offset
 786                                                       + 12)));
 787       pov += plt_entry_size;
 788     }
 789
 790   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
 791   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
 792
 793   of->write_output_view(offset, oview_size, oview);
 794   of->write_output_view(got_file_offset, got_size, got_view);
 795 }
 796
 797 // Create the PLT section.
 798
 799 void
 800 Target_x86_64::make_plt_section(Symbol_table* symtab, Layout* layout)
 801 {
 802   if (this->plt_ == NULL)
 803     {
 804       // Create the GOT sections first.
 805       this->got_section(symtab, layout);
 806
 807       this->plt_ = new Output_data_plt_x86_64(layout, this->got_,
 808                                               this->got_plt_);
 809       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
 810                                       (elfcpp::SHF_ALLOC
 811                                        | elfcpp::SHF_EXECINSTR),
 812                                       this->plt_, false, false, false, false);
 813     }
 814 }
 815
 816 // Create a PLT entry for a global symbol.
 817
 818 void
 819 Target_x86_64::make_plt_entry(Symbol_table* symtab, Layout* layout,
 820                               Symbol* gsym)
 821 {
 822   if (gsym->has_plt_offset())
 823     return;
 824
 825   if (this->plt_ == NULL)
 826     this->make_plt_section(symtab, layout);
 827
 828   this->plt_->add_entry(gsym);
 829 }
 830
 831 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
 832
 833 void
 834 Target_x86_64::define_tls_base_symbol(Symbol_table* symtab, Layout* layout)
 835 {
 836   if (this->tls_base_symbol_defined_)
 837     return;
 838
 839   Output_segment* tls_segment = layout->tls_segment();
 840   if (tls_segment != NULL)
 841     {
 842       bool is_exec = parameters->options().output_is_executable();
 843       symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
 844                                        Symbol_table::PREDEFINED,
 845                                        tls_segment, 0, 0,
 846                                        elfcpp::STT_TLS,
 847                                        elfcpp::STB_LOCAL,
 848                                        elfcpp::STV_HIDDEN, 0,
 849                                        (is_exec
 850                                         ? Symbol::SEGMENT_END
 851                                         : Symbol::SEGMENT_START),
 852                                        true);
 853     }
 854   this->tls_base_symbol_defined_ = true;
 855 }
 856
 857 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
 858
 859 void
 860 Target_x86_64::reserve_tlsdesc_entries(Symbol_table* symtab,
 861                                              Layout* layout)
 862 {
 863   if (this->plt_ == NULL)
 864     this->make_plt_section(symtab, layout);
 865
 866   if (!this->plt_->has_tlsdesc_entry())
 867     {
 868       // Allocate the TLSDESC_GOT entry.
 869       Output_data_got<64, false>* got = this->got_section(symtab, layout);
 870       unsigned int got_offset = got->add_constant(0);
 871
 872       // Allocate the TLSDESC_PLT entry.
 873       this->plt_->reserve_tlsdesc_entry(got_offset);
 874     }
 875 }
 876
 877 // Create a GOT entry for the TLS module index.
 878
 879 unsigned int
 880 Target_x86_64::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
 881                                    Sized_relobj<64, false>* object)
 882 {
 883   if (this->got_mod_index_offset_ == -1U)
 884     {
 885       gold_assert(symtab != NULL && layout != NULL && object != NULL);
 886       Reloc_section* rela_dyn = this->rela_dyn_section(layout);
 887       Output_data_got<64, false>* got = this->got_section(symtab, layout);
 888       unsigned int got_offset = got->add_constant(0);
 889       rela_dyn->add_local(object, 0, elfcpp::R_X86_64_DTPMOD64, got,
 890                           got_offset, 0);
 891       got->add_constant(0);
 892       this->got_mod_index_offset_ = got_offset;
 893     }
 894   return this->got_mod_index_offset_;
 895 }
 896
 897 // Optimize the TLS relocation type based on what we know about the
 898 // symbol.  IS_FINAL is true if the final address of this symbol is
 899 // known at link time.
 900
 901 tls::Tls_optimization
 902 Target_x86_64::optimize_tls_reloc(bool is_final, int r_type)
 903 {
 904   // If we are generating a shared library, then we can't do anything
 905   // in the linker.
 906   if (parameters->options().shared())
 907     return tls::TLSOPT_NONE;
 908
 909   switch (r_type)
 910     {
 911     case elfcpp::R_X86_64_TLSGD:
 912     case elfcpp::R_X86_64_GOTPC32_TLSDESC:
 913     case elfcpp::R_X86_64_TLSDESC_CALL:
 914       // These are General-Dynamic which permits fully general TLS
 915       // access.  Since we know that we are generating an executable,
 916       // we can convert this to Initial-Exec.  If we also know that
 917       // this is a local symbol, we can further switch to Local-Exec.
 918       if (is_final)
 919         return tls::TLSOPT_TO_LE;
 920       return tls::TLSOPT_TO_IE;
 921
 922     case elfcpp::R_X86_64_TLSLD:
 923       // This is Local-Dynamic, which refers to a local symbol in the
 924       // dynamic TLS block.  Since we know that we generating an
 925       // executable, we can switch to Local-Exec.
 926       return tls::TLSOPT_TO_LE;
 927
 928     case elfcpp::R_X86_64_DTPOFF32:
 929     case elfcpp::R_X86_64_DTPOFF64:
 930       // Another Local-Dynamic reloc.
 931       return tls::TLSOPT_TO_LE;
 932
 933     case elfcpp::R_X86_64_GOTTPOFF:
 934       // These are Initial-Exec relocs which get the thread offset
 935       // from the GOT.  If we know that we are linking against the
 936       // local symbol, we can switch to Local-Exec, which links the
 937       // thread offset into the instruction.
 938       if (is_final)
 939         return tls::TLSOPT_TO_LE;
 940       return tls::TLSOPT_NONE;
 941
 942     case elfcpp::R_X86_64_TPOFF32:
 943       // When we already have Local-Exec, there is nothing further we
 944       // can do.
 945       return tls::TLSOPT_NONE;
 946
 947     default:
 948       gold_unreachable();
 949     }
 950 }
 951
 952 // Report an unsupported relocation against a local symbol.
 953
 954 void
 955 Target_x86_64::Scan::unsupported_reloc_local(Sized_relobj<64, false>* object,
 956                                              unsigned int r_type)
 957 {
 958   gold_error(_("%s: unsupported reloc %u against local symbol"),
 959              object->name().c_str(), r_type);
 960 }
 961
 962 // We are about to emit a dynamic relocation of type R_TYPE.  If the
 963 // dynamic linker does not support it, issue an error.  The GNU linker
 964 // only issues a non-PIC error for an allocated read-only section.
 965 // Here we know the section is allocated, but we don't know that it is
 966 // read-only.  But we check for all the relocation types which the
 967 // glibc dynamic linker supports, so it seems appropriate to issue an
 968 // error even if the section is not read-only.
 969
 970 void
 971 Target_x86_64::Scan::check_non_pic(Relobj* object, unsigned int r_type)
 972 {
 973   switch (r_type)
 974     {
 975       // These are the relocation types supported by glibc for x86_64.
 976     case elfcpp::R_X86_64_RELATIVE:
 977     case elfcpp::R_X86_64_GLOB_DAT:
 978     case elfcpp::R_X86_64_JUMP_SLOT:
 979     case elfcpp::R_X86_64_DTPMOD64:
 980     case elfcpp::R_X86_64_DTPOFF64:
 981     case elfcpp::R_X86_64_TPOFF64:
 982     case elfcpp::R_X86_64_64:
 983     case elfcpp::R_X86_64_32:
 984     case elfcpp::R_X86_64_PC32:
 985     case elfcpp::R_X86_64_COPY:
 986       return;
 987
 988     default:
 989       // This prevents us from issuing more than one error per reloc
 990       // section.  But we can still wind up issuing more than one
 991       // error per object file.
 992       if (this->issued_non_pic_error_)
 993         return;
 994       gold_assert(parameters->options().output_is_position_independent());
 995       object->error(_("requires unsupported dynamic reloc; "
 996                       "recompile with -fPIC"));
 997       this->issued_non_pic_error_ = true;
 998       return;
 999
1000     case elfcpp::R_X86_64_NONE:
1001       gold_unreachable();
1002     }
1003 }
1004
1005 // Scan a relocation for a local symbol.
1006
1007 inline void
1008 Target_x86_64::Scan::local(Symbol_table* symtab,
1009                            Layout* layout,
1010                            Target_x86_64* target,
1011                            Sized_relobj<64, false>* object,
1012                            unsigned int data_shndx,
1013                            Output_section* output_section,
1014                            const elfcpp::Rela<64, false>& reloc,
1015                            unsigned int r_type,
1016                            const elfcpp::Sym<64, false>& lsym)
1017 {
1018   switch (r_type)
1019     {
1020     case elfcpp::R_X86_64_NONE:
1021     case elfcpp::R_386_GNU_VTINHERIT:
1022     case elfcpp::R_386_GNU_VTENTRY:
1023       break;
1024
1025     case elfcpp::R_X86_64_64:
1026       // If building a shared library (or a position-independent
1027       // executable), we need to create a dynamic relocation for this
1028       // location.  The relocation applied at link time will apply the
1029       // link-time value, so we flag the location with an
1030       // R_X86_64_RELATIVE relocation so the dynamic loader can
1031       // relocate it easily.
1032       if (parameters->options().output_is_position_independent())
1033         {
1034           unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
1035           Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1036           rela_dyn->add_local_relative(object, r_sym,
1037                                        elfcpp::R_X86_64_RELATIVE,
1038                                        output_section, data_shndx,
1039                                        reloc.get_r_offset(),
1040                                        reloc.get_r_addend());
1041         }
1042       break;
1043
1044     case elfcpp::R_X86_64_32:
1045     case elfcpp::R_X86_64_32S:
1046     case elfcpp::R_X86_64_16:
1047     case elfcpp::R_X86_64_8:
1048       // If building a shared library (or a position-independent
1049       // executable), we need to create a dynamic relocation for this
1050       // location.  We can't use an R_X86_64_RELATIVE relocation
1051       // because that is always a 64-bit relocation.
1052       if (parameters->options().output_is_position_independent())
1053         {
1054           this->check_non_pic(object, r_type);
1055
1056           Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1057           unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
1058           if (lsym.get_st_type() != elfcpp::STT_SECTION)
1059             rela_dyn->add_local(object, r_sym, r_type, output_section,
1060                                 data_shndx, reloc.get_r_offset(),
1061                                 reloc.get_r_addend());
1062           else
1063             {
1064               gold_assert(lsym.get_st_value() == 0);
1065               unsigned int shndx = lsym.get_st_shndx();
1066               bool is_ordinary;
1067               shndx = object->adjust_sym_shndx(r_sym, shndx,
1068                                                &is_ordinary);
1069               if (!is_ordinary)
1070                 object->error(_("section symbol %u has bad shndx %u"),
1071                               r_sym, shndx);
1072               else
1073                 rela_dyn->add_local_section(object, shndx,
1074                                             r_type, output_section,
1075                                             data_shndx, reloc.get_r_offset(),
1076                                             reloc.get_r_addend());
1077             }
1078         }
1079       break;
1080
1081     case elfcpp::R_X86_64_PC64:
1082     case elfcpp::R_X86_64_PC32:
1083     case elfcpp::R_X86_64_PC16:
1084     case elfcpp::R_X86_64_PC8:
1085       break;
1086
1087     case elfcpp::R_X86_64_PLT32:
1088       // Since we know this is a local symbol, we can handle this as a
1089       // PC32 reloc.
1090       break;
1091
1092     case elfcpp::R_X86_64_GOTPC32:
1093     case elfcpp::R_X86_64_GOTOFF64:
1094     case elfcpp::R_X86_64_GOTPC64:
1095     case elfcpp::R_X86_64_PLTOFF64:
1096       // We need a GOT section.
1097       target->got_section(symtab, layout);
1098       // For PLTOFF64, we'd normally want a PLT section, but since we
1099       // know this is a local symbol, no PLT is needed.
1100       break;
1101
1102     case elfcpp::R_X86_64_GOT64:
1103     case elfcpp::R_X86_64_GOT32:
1104     case elfcpp::R_X86_64_GOTPCREL64:
1105     case elfcpp::R_X86_64_GOTPCREL:
1106     case elfcpp::R_X86_64_GOTPLT64:
1107       {
1108         // The symbol requires a GOT entry.
1109         Output_data_got<64, false>* got = target->got_section(symtab, layout);
1110         unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
1111         if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
1112           {
1113             // If we are generating a shared object, we need to add a
1114             // dynamic relocation for this symbol's GOT entry.
1115             if (parameters->options().output_is_position_independent())
1116               {
1117                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1118                 // R_X86_64_RELATIVE assumes a 64-bit relocation.
1119                 if (r_type != elfcpp::R_X86_64_GOT32)
1120                   rela_dyn->add_local_relative(
1121                       object, r_sym, elfcpp::R_X86_64_RELATIVE, got,
1122                       object->local_got_offset(r_sym, GOT_TYPE_STANDARD), 0);
1123                 else
1124                   {
1125                     this->check_non_pic(object, r_type);
1126
1127                     gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
1128                     rela_dyn->add_local(
1129                         object, r_sym, r_type, got,
1130                         object->local_got_offset(r_sym, GOT_TYPE_STANDARD), 0);
1131                   }
1132               }
1133           }
1134         // For GOTPLT64, we'd normally want a PLT section, but since
1135         // we know this is a local symbol, no PLT is needed.
1136       }
1137       break;
1138
1139     case elfcpp::R_X86_64_COPY:
1140     case elfcpp::R_X86_64_GLOB_DAT:
1141     case elfcpp::R_X86_64_JUMP_SLOT:
1142     case elfcpp::R_X86_64_RELATIVE:
1143       // These are outstanding tls relocs, which are unexpected when linking
1144     case elfcpp::R_X86_64_TPOFF64:
1145     case elfcpp::R_X86_64_DTPMOD64:
1146     case elfcpp::R_X86_64_TLSDESC:
1147       gold_error(_("%s: unexpected reloc %u in object file"),
1148                  object->name().c_str(), r_type);
1149       break;
1150
1151       // These are initial tls relocs, which are expected when linking
1152     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
1153     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
1154     case elfcpp::R_X86_64_TLSDESC_CALL:
1155     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
1156     case elfcpp::R_X86_64_DTPOFF32:
1157     case elfcpp::R_X86_64_DTPOFF64:
1158     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
1159     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
1160       {
1161         bool output_is_shared = parameters->options().shared();
1162         const tls::Tls_optimization optimized_type
1163             = Target_x86_64::optimize_tls_reloc(!output_is_shared, r_type);
1164         switch (r_type)
1165           {
1166           case elfcpp::R_X86_64_TLSGD:       // General-dynamic
1167             if (optimized_type == tls::TLSOPT_NONE)
1168               {
1169                 // Create a pair of GOT entries for the module index and
1170                 // dtv-relative offset.
1171                 Output_data_got<64, false>* got
1172                     = target->got_section(symtab, layout);
1173                 unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
1174                 unsigned int shndx = lsym.get_st_shndx();
1175                 bool is_ordinary;
1176                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1177                 if (!is_ordinary)
1178                   object->error(_("local symbol %u has bad shndx %u"),
1179                               r_sym, shndx);
1180                 else
1181                   got->add_local_pair_with_rela(object, r_sym,
1182                                                 shndx,
1183                                                 GOT_TYPE_TLS_PAIR,
1184                                                 target->rela_dyn_section(layout),
1185                                                 elfcpp::R_X86_64_DTPMOD64, 0);
1186               }
1187             else if (optimized_type != tls::TLSOPT_TO_LE)
1188               unsupported_reloc_local(object, r_type);
1189             break;
1190
1191           case elfcpp::R_X86_64_GOTPC32_TLSDESC:
1192             target->define_tls_base_symbol(symtab, layout);
1193             if (optimized_type == tls::TLSOPT_NONE)
1194               {
1195                 // Create reserved PLT and GOT entries for the resolver.
1196                 target->reserve_tlsdesc_entries(symtab, layout);
1197
1198                 // Generate a double GOT entry with an R_X86_64_TLSDESC reloc.
1199                 Output_data_got<64, false>* got
1200                     = target->got_section(symtab, layout);
1201                 unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
1202                 unsigned int shndx = lsym.get_st_shndx();
1203                 bool is_ordinary;
1204                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1205                 if (!is_ordinary)
1206                   object->error(_("local symbol %u has bad shndx %u"),
1207                               r_sym, shndx);
1208                 else
1209                   got->add_local_pair_with_rela(object, r_sym,
1210                                                 shndx,
1211                                                 GOT_TYPE_TLS_DESC,
1212                                                 target->rela_dyn_section(layout),
1213                                                 elfcpp::R_X86_64_TLSDESC, 0);
1214               }
1215             else if (optimized_type != tls::TLSOPT_TO_LE)
1216               unsupported_reloc_local(object, r_type);
1217             break;
1218
1219           case elfcpp::R_X86_64_TLSDESC_CALL:
1220             break;
1221
1222           case elfcpp::R_X86_64_TLSLD:       // Local-dynamic
1223             if (optimized_type == tls::TLSOPT_NONE)
1224               {
1225                 // Create a GOT entry for the module index.
1226                 target->got_mod_index_entry(symtab, layout, object);
1227               }
1228             else if (optimized_type != tls::TLSOPT_TO_LE)
1229               unsupported_reloc_local(object, r_type);
1230             break;
1231
1232           case elfcpp::R_X86_64_DTPOFF32:
1233           case elfcpp::R_X86_64_DTPOFF64:
1234             break;
1235
1236           case elfcpp::R_X86_64_GOTTPOFF:    // Initial-exec
1237             layout->set_has_static_tls();
1238             if (optimized_type == tls::TLSOPT_NONE)
1239               {
1240                 // Create a GOT entry for the tp-relative offset.
1241                 Output_data_got<64, false>* got
1242                     = target->got_section(symtab, layout);
1243                 unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
1244                 got->add_local_with_rela(object, r_sym, GOT_TYPE_TLS_OFFSET,
1245                                          target->rela_dyn_section(layout),
1246                                          elfcpp::R_X86_64_TPOFF64);
1247               }
1248             else if (optimized_type != tls::TLSOPT_TO_LE)
1249               unsupported_reloc_local(object, r_type);
1250             break;
1251
1252           case elfcpp::R_X86_64_TPOFF32:     // Local-exec
1253             layout->set_has_static_tls();
1254             if (output_is_shared)
1255               unsupported_reloc_local(object, r_type);
1256             break;
1257
1258           default:
1259             gold_unreachable();
1260           }
1261       }
1262       break;
1263
1264     case elfcpp::R_X86_64_SIZE32:
1265     case elfcpp::R_X86_64_SIZE64:
1266     default:
1267       gold_error(_("%s: unsupported reloc %u against local symbol"),
1268                  object->name().c_str(), r_type);
1269       break;
1270     }
1271 }
1272
1273
1274 // Report an unsupported relocation against a global symbol.
1275
1276 void
1277 Target_x86_64::Scan::unsupported_reloc_global(Sized_relobj<64, false>* object,
1278                                               unsigned int r_type,
1279                                               Symbol* gsym)
1280 {
1281   gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1282              object->name().c_str(), r_type, gsym->demangled_name().c_str());
1283 }
1284
1285 // Scan a relocation for a global symbol.
1286
1287 inline void
1288 Target_x86_64::Scan::global(Symbol_table* symtab,
1289                             Layout* layout,
1290                             Target_x86_64* target,
1291                             Sized_relobj<64, false>* object,
1292                             unsigned int data_shndx,
1293                             Output_section* output_section,
1294                             const elfcpp::Rela<64, false>& reloc,
1295                             unsigned int r_type,
1296                             Symbol* gsym)
1297 {
1298   switch (r_type)
1299     {
1300     case elfcpp::R_X86_64_NONE:
1301     case elfcpp::R_386_GNU_VTINHERIT:
1302     case elfcpp::R_386_GNU_VTENTRY:
1303       break;
1304
1305     case elfcpp::R_X86_64_64:
1306     case elfcpp::R_X86_64_32:
1307     case elfcpp::R_X86_64_32S:
1308     case elfcpp::R_X86_64_16:
1309     case elfcpp::R_X86_64_8:
1310       {
1311         // Make a PLT entry if necessary.
1312         if (gsym->needs_plt_entry())
1313           {
1314             target->make_plt_entry(symtab, layout, gsym);
1315             // Since this is not a PC-relative relocation, we may be
1316             // taking the address of a function. In that case we need to
1317             // set the entry in the dynamic symbol table to the address of
1318             // the PLT entry.
1319             if (gsym->is_from_dynobj() && !parameters->options().shared())
1320               gsym->set_needs_dynsym_value();
1321           }
1322         // Make a dynamic relocation if necessary.
1323         if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
1324           {
1325             if (gsym->may_need_copy_reloc())
1326               {
1327                 target->copy_reloc(symtab, layout, object,
1328                                    data_shndx, output_section, gsym, reloc);
1329               }
1330             else if (r_type == elfcpp::R_X86_64_64
1331                      && gsym->can_use_relative_reloc(false))
1332               {
1333                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1334                 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_RELATIVE,
1335                                               output_section, object,
1336                                               data_shndx, reloc.get_r_offset(),
1337                                               reloc.get_r_addend());
1338               }
1339             else
1340               {
1341                 this->check_non_pic(object, r_type);
1342                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1343                 rela_dyn->add_global(gsym, r_type, output_section, object,
1344                                      data_shndx, reloc.get_r_offset(),
1345                                      reloc.get_r_addend());
1346               }
1347           }
1348       }
1349       break;
1350
1351     case elfcpp::R_X86_64_PC64:
1352     case elfcpp::R_X86_64_PC32:
1353     case elfcpp::R_X86_64_PC16:
1354     case elfcpp::R_X86_64_PC8:
1355       {
1356         // Make a PLT entry if necessary.
1357         if (gsym->needs_plt_entry())
1358           target->make_plt_entry(symtab, layout, gsym);
1359         // Make a dynamic relocation if necessary.
1360         int flags = Symbol::NON_PIC_REF;
1361         if (gsym->is_func())
1362           flags |= Symbol::FUNCTION_CALL;
1363         if (gsym->needs_dynamic_reloc(flags))
1364           {
1365             if (gsym->may_need_copy_reloc())
1366               {
1367                 target->copy_reloc(symtab, layout, object,
1368                                    data_shndx, output_section, gsym, reloc);
1369               }
1370             else
1371               {
1372                 this->check_non_pic(object, r_type);
1373                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1374                 rela_dyn->add_global(gsym, r_type, output_section, object,
1375                                      data_shndx, reloc.get_r_offset(),
1376                                      reloc.get_r_addend());
1377               }
1378           }
1379       }
1380       break;
1381
1382     case elfcpp::R_X86_64_GOT64:
1383     case elfcpp::R_X86_64_GOT32:
1384     case elfcpp::R_X86_64_GOTPCREL64:
1385     case elfcpp::R_X86_64_GOTPCREL:
1386     case elfcpp::R_X86_64_GOTPLT64:
1387       {
1388         // The symbol requires a GOT entry.
1389         Output_data_got<64, false>* got = target->got_section(symtab, layout);
1390         if (gsym->final_value_is_known())
1391           got->add_global(gsym, GOT_TYPE_STANDARD);
1392         else
1393           {
1394             // If this symbol is not fully resolved, we need to add a
1395             // dynamic relocation for it.
1396             Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1397             if (gsym->is_from_dynobj()
1398                 || gsym->is_undefined()
1399                 || gsym->is_preemptible())
1400               got->add_global_with_rela(gsym, GOT_TYPE_STANDARD, rela_dyn,
1401                                         elfcpp::R_X86_64_GLOB_DAT);
1402             else
1403               {
1404                 if (got->add_global(gsym, GOT_TYPE_STANDARD))
1405                   rela_dyn->add_global_relative(
1406                       gsym, elfcpp::R_X86_64_RELATIVE, got,
1407                       gsym->got_offset(GOT_TYPE_STANDARD), 0);
1408               }
1409           }
1410         // For GOTPLT64, we also need a PLT entry (but only if the
1411         // symbol is not fully resolved).
1412         if (r_type == elfcpp::R_X86_64_GOTPLT64
1413             && !gsym->final_value_is_known())
1414           target->make_plt_entry(symtab, layout, gsym);
1415       }
1416       break;
1417
1418     case elfcpp::R_X86_64_PLT32:
1419       // If the symbol is fully resolved, this is just a PC32 reloc.
1420       // Otherwise we need a PLT entry.
1421       if (gsym->final_value_is_known())
1422         break;
1423       // If building a shared library, we can also skip the PLT entry
1424       // if the symbol is defined in the output file and is protected
1425       // or hidden.
1426       if (gsym->is_defined()
1427           && !gsym->is_from_dynobj()
1428           && !gsym->is_preemptible())
1429         break;
1430       target->make_plt_entry(symtab, layout, gsym);
1431       break;
1432
1433     case elfcpp::R_X86_64_GOTPC32:
1434     case elfcpp::R_X86_64_GOTOFF64:
1435     case elfcpp::R_X86_64_GOTPC64:
1436     case elfcpp::R_X86_64_PLTOFF64:
1437       // We need a GOT section.
1438       target->got_section(symtab, layout);
1439       // For PLTOFF64, we also need a PLT entry (but only if the
1440       // symbol is not fully resolved).
1441       if (r_type == elfcpp::R_X86_64_PLTOFF64
1442           && !gsym->final_value_is_known())
1443         target->make_plt_entry(symtab, layout, gsym);
1444       break;
1445
1446     case elfcpp::R_X86_64_COPY:
1447     case elfcpp::R_X86_64_GLOB_DAT:
1448     case elfcpp::R_X86_64_JUMP_SLOT:
1449     case elfcpp::R_X86_64_RELATIVE:
1450       // These are outstanding tls relocs, which are unexpected when linking
1451     case elfcpp::R_X86_64_TPOFF64:
1452     case elfcpp::R_X86_64_DTPMOD64:
1453     case elfcpp::R_X86_64_TLSDESC:
1454       gold_error(_("%s: unexpected reloc %u in object file"),
1455                  object->name().c_str(), r_type);
1456       break;
1457
1458       // These are initial tls relocs, which are expected for global()
1459     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
1460     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
1461     case elfcpp::R_X86_64_TLSDESC_CALL:
1462     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
1463     case elfcpp::R_X86_64_DTPOFF32:
1464     case elfcpp::R_X86_64_DTPOFF64:
1465     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
1466     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
1467       {
1468         const bool is_final = gsym->final_value_is_known();
1469         const tls::Tls_optimization optimized_type
1470             = Target_x86_64::optimize_tls_reloc(is_final, r_type);
1471         switch (r_type)
1472           {
1473           case elfcpp::R_X86_64_TLSGD:       // General-dynamic
1474             if (optimized_type == tls::TLSOPT_NONE)
1475               {
1476                 // Create a pair of GOT entries for the module index and
1477                 // dtv-relative offset.
1478                 Output_data_got<64, false>* got
1479                     = target->got_section(symtab, layout);
1480                 got->add_global_pair_with_rela(gsym, GOT_TYPE_TLS_PAIR,
1481                                                target->rela_dyn_section(layout),
1482                                                elfcpp::R_X86_64_DTPMOD64,
1483                                                elfcpp::R_X86_64_DTPOFF64);
1484               }
1485             else if (optimized_type == tls::TLSOPT_TO_IE)
1486               {
1487                 // Create a GOT entry for the tp-relative offset.
1488                 Output_data_got<64, false>* got
1489                     = target->got_section(symtab, layout);
1490                 got->add_global_with_rela(gsym, GOT_TYPE_TLS_OFFSET,
1491                                           target->rela_dyn_section(layout),
1492                                           elfcpp::R_X86_64_TPOFF64);
1493               }
1494             else if (optimized_type != tls::TLSOPT_TO_LE)
1495               unsupported_reloc_global(object, r_type, gsym);
1496             break;
1497
1498           case elfcpp::R_X86_64_GOTPC32_TLSDESC:
1499             target->define_tls_base_symbol(symtab, layout);
1500             if (optimized_type == tls::TLSOPT_NONE)
1501               {
1502                 // Create reserved PLT and GOT entries for the resolver.
1503                 target->reserve_tlsdesc_entries(symtab, layout);
1504
1505                 // Create a double GOT entry with an R_X86_64_TLSDESC reloc.
1506                 Output_data_got<64, false>* got
1507                     = target->got_section(symtab, layout);
1508                 got->add_global_pair_with_rela(gsym, GOT_TYPE_TLS_DESC,
1509                                                target->rela_dyn_section(layout),
1510                                                elfcpp::R_X86_64_TLSDESC, 0);
1511               }
1512             else if (optimized_type == tls::TLSOPT_TO_IE)
1513               {
1514                 // Create a GOT entry for the tp-relative offset.
1515                 Output_data_got<64, false>* got
1516                     = target->got_section(symtab, layout);
1517                 got->add_global_with_rela(gsym, GOT_TYPE_TLS_OFFSET,
1518                                           target->rela_dyn_section(layout),
1519                                           elfcpp::R_X86_64_TPOFF64);
1520               }
1521             else if (optimized_type != tls::TLSOPT_TO_LE)
1522               unsupported_reloc_global(object, r_type, gsym);
1523             break;
1524
1525           case elfcpp::R_X86_64_TLSDESC_CALL:
1526             break;
1527
1528           case elfcpp::R_X86_64_TLSLD:       // Local-dynamic
1529             if (optimized_type == tls::TLSOPT_NONE)
1530               {
1531                 // Create a GOT entry for the module index.
1532                 target->got_mod_index_entry(symtab, layout, object);
1533               }
1534             else if (optimized_type != tls::TLSOPT_TO_LE)
1535               unsupported_reloc_global(object, r_type, gsym);
1536             break;
1537
1538           case elfcpp::R_X86_64_DTPOFF32:
1539           case elfcpp::R_X86_64_DTPOFF64:
1540             break;
1541
1542           case elfcpp::R_X86_64_GOTTPOFF:    // Initial-exec
1543             layout->set_has_static_tls();
1544             if (optimized_type == tls::TLSOPT_NONE)
1545               {
1546                 // Create a GOT entry for the tp-relative offset.
1547                 Output_data_got<64, false>* got
1548                     = target->got_section(symtab, layout);
1549                 got->add_global_with_rela(gsym, GOT_TYPE_TLS_OFFSET,
1550                                           target->rela_dyn_section(layout),
1551                                           elfcpp::R_X86_64_TPOFF64);
1552               }
1553             else if (optimized_type != tls::TLSOPT_TO_LE)
1554               unsupported_reloc_global(object, r_type, gsym);
1555             break;
1556
1557           case elfcpp::R_X86_64_TPOFF32:     // Local-exec
1558             layout->set_has_static_tls();
1559             if (parameters->options().shared())
1560               unsupported_reloc_local(object, r_type);
1561             break;
1562
1563           default:
1564             gold_unreachable();
1565           }
1566       }
1567       break;
1568
1569     case elfcpp::R_X86_64_SIZE32:
1570     case elfcpp::R_X86_64_SIZE64:
1571     default:
1572       gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1573                  object->name().c_str(), r_type,
1574                  gsym->demangled_name().c_str());
1575       break;
1576     }
1577 }
1578
1579 void
1580 Target_x86_64::gc_process_relocs(Symbol_table* symtab,
1581                                  Layout* layout,
1582                                  Sized_relobj<64, false>* object,
1583                                  unsigned int data_shndx,
1584                                  unsigned int sh_type,
1585                                  const unsigned char* prelocs,
1586                                  size_t reloc_count,
1587                                  Output_section* output_section,
1588                                  bool needs_special_offset_handling,
1589                                  size_t local_symbol_count,
1590                                  const unsigned char* plocal_symbols)
1591 {
1592
1593   if (sh_type == elfcpp::SHT_REL)
1594     {
1595       return;
1596     }
1597
1598    gold::gc_process_relocs<64, false, Target_x86_64, elfcpp::SHT_RELA,
1599                            Target_x86_64::Scan>(
1600     symtab,
1601     layout,
1602     this,
1603     object,
1604     data_shndx,
1605     prelocs,
1606     reloc_count,
1607     output_section,
1608     needs_special_offset_handling,
1609     local_symbol_count,
1610     plocal_symbols);
1611
1612 }
1613 // Scan relocations for a section.
1614
1615 void
1616 Target_x86_64::scan_relocs(Symbol_table* symtab,
1617                            Layout* layout,
1618                            Sized_relobj<64, false>* object,
1619                            unsigned int data_shndx,
1620                            unsigned int sh_type,
1621                            const unsigned char* prelocs,
1622                            size_t reloc_count,
1623                            Output_section* output_section,
1624                            bool needs_special_offset_handling,
1625                            size_t local_symbol_count,
1626                            const unsigned char* plocal_symbols)
1627 {
1628   if (sh_type == elfcpp::SHT_REL)
1629     {
1630       gold_error(_("%s: unsupported REL reloc section"),
1631                  object->name().c_str());
1632       return;
1633     }
1634
1635   gold::scan_relocs<64, false, Target_x86_64, elfcpp::SHT_RELA,
1636       Target_x86_64::Scan>(
1637     symtab,
1638     layout,
1639     this,
1640     object,
1641     data_shndx,
1642     prelocs,
1643     reloc_count,
1644     output_section,
1645     needs_special_offset_handling,
1646     local_symbol_count,
1647     plocal_symbols);
1648 }
1649
1650 // Finalize the sections.
1651
1652 void
1653 Target_x86_64::do_finalize_sections(
1654     Layout* layout,
1655     const Input_objects*,
1656     Symbol_table* symtab)
1657 {
1658   // Fill in some more dynamic tags.
1659   Output_data_dynamic* const odyn = layout->dynamic_data();
1660   if (odyn != NULL)
1661     {
1662       if (this->got_plt_ != NULL
1663           && this->got_plt_->output_section() != NULL)
1664         odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_);
1665
1666       if (this->plt_ != NULL
1667           && this->plt_->output_section() != NULL)
1668         {
1669           const Output_data* od = this->plt_->rel_plt();
1670           odyn->add_section_size(elfcpp::DT_PLTRELSZ, od);
1671           odyn->add_section_address(elfcpp::DT_JMPREL, od);
1672           odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_RELA);
1673           if (this->plt_->has_tlsdesc_entry())
1674             {
1675               unsigned int plt_offset = this->plt_->get_tlsdesc_plt_offset();
1676               unsigned int got_offset = this->plt_->get_tlsdesc_got_offset();
1677               this->got_->finalize_data_size();
1678               odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_PLT,
1679                                             this->plt_, plt_offset);
1680               odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_GOT,
1681                                             this->got_, got_offset);
1682             }
1683         }
1684
1685       if (this->rela_dyn_ != NULL
1686           && this->rela_dyn_->output_section() != NULL)
1687         {
1688           const Output_data* od = this->rela_dyn_;
1689           odyn->add_section_address(elfcpp::DT_RELA, od);
1690           odyn->add_section_size(elfcpp::DT_RELASZ, od);
1691           odyn->add_constant(elfcpp::DT_RELAENT,
1692                              elfcpp::Elf_sizes<64>::rela_size);
1693         }
1694
1695       if (!parameters->options().shared())
1696         {
1697           // The value of the DT_DEBUG tag is filled in by the dynamic
1698           // linker at run time, and used by the debugger.
1699           odyn->add_constant(elfcpp::DT_DEBUG, 0);
1700         }
1701     }
1702
1703   // Emit any relocs we saved in an attempt to avoid generating COPY
1704   // relocs.
1705   if (this->copy_relocs_.any_saved_relocs())
1706     this->copy_relocs_.emit(this->rela_dyn_section(layout));
1707
1708   // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
1709   // the .got.plt section.
1710   Symbol* sym = this->global_offset_table_;
1711   if (sym != NULL)
1712     {
1713       uint64_t data_size = this->got_plt_->current_data_size();
1714       symtab->get_sized_symbol<64>(sym)->set_symsize(data_size);
1715     }
1716 }
1717
1718 // Perform a relocation.
1719
1720 inline bool
1721 Target_x86_64::Relocate::relocate(const Relocate_info<64, false>* relinfo,
1722                                   Target_x86_64* target,
1723                                   Output_section*,
1724                                   size_t relnum,
1725                                   const elfcpp::Rela<64, false>& rela,
1726                                   unsigned int r_type,
1727                                   const Sized_symbol<64>* gsym,
1728                                   const Symbol_value<64>* psymval,
1729                                   unsigned char* view,
1730                                   elfcpp::Elf_types<64>::Elf_Addr address,
1731                                   section_size_type view_size)
1732 {
1733   if (this->skip_call_tls_get_addr_)
1734     {
1735       if ((r_type != elfcpp::R_X86_64_PLT32
1736            && r_type != elfcpp::R_X86_64_PC32)
1737           || gsym == NULL
1738           || strcmp(gsym->name(), "__tls_get_addr") != 0)
1739         {
1740           gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
1741                                  _("missing expected TLS relocation"));
1742         }
1743       else
1744         {
1745           this->skip_call_tls_get_addr_ = false;
1746           return false;
1747         }
1748     }
1749
1750   // Pick the value to use for symbols defined in shared objects.
1751   Symbol_value<64> symval;
1752   if (gsym != NULL
1753       && gsym->use_plt_offset(r_type == elfcpp::R_X86_64_PC64
1754                               || r_type == elfcpp::R_X86_64_PC32
1755                               || r_type == elfcpp::R_X86_64_PC16
1756                               || r_type == elfcpp::R_X86_64_PC8))
1757     {
1758       symval.set_output_value(target->plt_section()->address()
1759                               + gsym->plt_offset());
1760       psymval = &symval;
1761     }
1762
1763   const Sized_relobj<64, false>* object = relinfo->object;
1764   const elfcpp::Elf_Xword addend = rela.get_r_addend();
1765
1766   // Get the GOT offset if needed.
1767   // The GOT pointer points to the end of the GOT section.
1768   // We need to subtract the size of the GOT section to get
1769   // the actual offset to use in the relocation.
1770   bool have_got_offset = false;
1771   unsigned int got_offset = 0;
1772   switch (r_type)
1773     {
1774     case elfcpp::R_X86_64_GOT32:
1775     case elfcpp::R_X86_64_GOT64:
1776     case elfcpp::R_X86_64_GOTPLT64:
1777     case elfcpp::R_X86_64_GOTPCREL:
1778     case elfcpp::R_X86_64_GOTPCREL64:
1779       if (gsym != NULL)
1780         {
1781           gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
1782           got_offset = gsym->got_offset(GOT_TYPE_STANDARD) - target->got_size();
1783         }
1784       else
1785         {
1786           unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
1787           gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
1788           got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
1789                         - target->got_size());
1790         }
1791       have_got_offset = true;
1792       break;
1793
1794     default:
1795       break;
1796     }
1797
1798   switch (r_type)
1799     {
1800     case elfcpp::R_X86_64_NONE:
1801     case elfcpp::R_386_GNU_VTINHERIT:
1802     case elfcpp::R_386_GNU_VTENTRY:
1803       break;
1804
1805     case elfcpp::R_X86_64_64:
1806       Relocate_functions<64, false>::rela64(view, object, psymval, addend);
1807       break;
1808
1809     case elfcpp::R_X86_64_PC64:
1810       Relocate_functions<64, false>::pcrela64(view, object, psymval, addend,
1811                                               address);
1812       break;
1813
1814     case elfcpp::R_X86_64_32:
1815       // FIXME: we need to verify that value + addend fits into 32 bits:
1816       //    uint64_t x = value + addend;
1817       //    x == static_cast<uint64_t>(static_cast<uint32_t>(x))
1818       // Likewise for other <=32-bit relocations (but see R_X86_64_32S).
1819       Relocate_functions<64, false>::rela32(view, object, psymval, addend);
1820       break;
1821
1822     case elfcpp::R_X86_64_32S:
1823       // FIXME: we need to verify that value + addend fits into 32 bits:
1824       //    int64_t x = value + addend;   // note this quantity is signed!
1825       //    x == static_cast<int64_t>(static_cast<int32_t>(x))
1826       Relocate_functions<64, false>::rela32(view, object, psymval, addend);
1827       break;
1828
1829     case elfcpp::R_X86_64_PC32:
1830       Relocate_functions<64, false>::pcrela32(view, object, psymval, addend,
1831                                               address);
1832       break;
1833
1834     case elfcpp::R_X86_64_16:
1835       Relocate_functions<64, false>::rela16(view, object, psymval, addend);
1836       break;
1837
1838     case elfcpp::R_X86_64_PC16:
1839       Relocate_functions<64, false>::pcrela16(view, object, psymval, addend,
1840                                               address);
1841       break;
1842
1843     case elfcpp::R_X86_64_8:
1844       Relocate_functions<64, false>::rela8(view, object, psymval, addend);
1845       break;
1846
1847     case elfcpp::R_X86_64_PC8:
1848       Relocate_functions<64, false>::pcrela8(view, object, psymval, addend,
1849                                              address);
1850       break;
1851
1852     case elfcpp::R_X86_64_PLT32:
1853       gold_assert(gsym == NULL
1854                   || gsym->has_plt_offset()
1855                   || gsym->final_value_is_known()
1856                   || (gsym->is_defined()
1857                       && !gsym->is_from_dynobj()
1858                       && !gsym->is_preemptible()));
1859       // Note: while this code looks the same as for R_X86_64_PC32, it
1860       // behaves differently because psymval was set to point to
1861       // the PLT entry, rather than the symbol, in Scan::global().
1862       Relocate_functions<64, false>::pcrela32(view, object, psymval, addend,
1863                                               address);
1864       break;
1865
1866     case elfcpp::R_X86_64_PLTOFF64:
1867       {
1868         gold_assert(gsym);
1869         gold_assert(gsym->has_plt_offset()
1870                     || gsym->final_value_is_known());
1871         elfcpp::Elf_types<64>::Elf_Addr got_address;
1872         got_address = target->got_section(NULL, NULL)->address();
1873         Relocate_functions<64, false>::rela64(view, object, psymval,
1874                                               addend - got_address);
1875       }
1876
1877     case elfcpp::R_X86_64_GOT32:
1878       gold_assert(have_got_offset);
1879       Relocate_functions<64, false>::rela32(view, got_offset, addend);
1880       break;
1881
1882     case elfcpp::R_X86_64_GOTPC32:
1883       {
1884         gold_assert(gsym);
1885         elfcpp::Elf_types<64>::Elf_Addr value;
1886         value = target->got_plt_section()->address();
1887         Relocate_functions<64, false>::pcrela32(view, value, addend, address);
1888       }
1889       break;
1890
1891     case elfcpp::R_X86_64_GOT64:
1892       // The ABI doc says "Like GOT64, but indicates a PLT entry is needed."
1893       // Since we always add a PLT entry, this is equivalent.
1894     case elfcpp::R_X86_64_GOTPLT64:
1895       gold_assert(have_got_offset);
1896       Relocate_functions<64, false>::rela64(view, got_offset, addend);
1897       break;
1898
1899     case elfcpp::R_X86_64_GOTPC64:
1900       {
1901         gold_assert(gsym);
1902         elfcpp::Elf_types<64>::Elf_Addr value;
1903         value = target->got_plt_section()->address();
1904         Relocate_functions<64, false>::pcrela64(view, value, addend, address);
1905       }
1906       break;
1907
1908     case elfcpp::R_X86_64_GOTOFF64:
1909       {
1910         elfcpp::Elf_types<64>::Elf_Addr value;
1911         value = (psymval->value(object, 0)
1912                  - target->got_plt_section()->address());
1913         Relocate_functions<64, false>::rela64(view, value, addend);
1914       }
1915       break;
1916
1917     case elfcpp::R_X86_64_GOTPCREL:
1918       {
1919         gold_assert(have_got_offset);
1920         elfcpp::Elf_types<64>::Elf_Addr value;
1921         value = target->got_plt_section()->address() + got_offset;
1922         Relocate_functions<64, false>::pcrela32(view, value, addend, address);
1923       }
1924       break;
1925
1926     case elfcpp::R_X86_64_GOTPCREL64:
1927       {
1928         gold_assert(have_got_offset);
1929         elfcpp::Elf_types<64>::Elf_Addr value;
1930         value = target->got_plt_section()->address() + got_offset;
1931         Relocate_functions<64, false>::pcrela64(view, value, addend, address);
1932       }
1933       break;
1934
1935     case elfcpp::R_X86_64_COPY:
1936     case elfcpp::R_X86_64_GLOB_DAT:
1937     case elfcpp::R_X86_64_JUMP_SLOT:
1938     case elfcpp::R_X86_64_RELATIVE:
1939       // These are outstanding tls relocs, which are unexpected when linking
1940     case elfcpp::R_X86_64_TPOFF64:
1941     case elfcpp::R_X86_64_DTPMOD64:
1942     case elfcpp::R_X86_64_TLSDESC:
1943       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
1944                              _("unexpected reloc %u in object file"),
1945                              r_type);
1946       break;
1947
1948       // These are initial tls relocs, which are expected when linking
1949     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
1950     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
1951     case elfcpp::R_X86_64_TLSDESC_CALL:
1952     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
1953     case elfcpp::R_X86_64_DTPOFF32:
1954     case elfcpp::R_X86_64_DTPOFF64:
1955     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
1956     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
1957       this->relocate_tls(relinfo, target, relnum, rela, r_type, gsym, psymval,
1958                          view, address, view_size);
1959       break;
1960
1961     case elfcpp::R_X86_64_SIZE32:
1962     case elfcpp::R_X86_64_SIZE64:
1963     default:
1964       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
1965                              _("unsupported reloc %u"),
1966                              r_type);
1967       break;
1968     }
1969
1970   return true;
1971 }
1972
1973 // Perform a TLS relocation.
1974
1975 inline void
1976 Target_x86_64::Relocate::relocate_tls(const Relocate_info<64, false>* relinfo,
1977                                       Target_x86_64* target,
1978                                       size_t relnum,
1979                                       const elfcpp::Rela<64, false>& rela,
1980                                       unsigned int r_type,
1981                                       const Sized_symbol<64>* gsym,
1982                                       const Symbol_value<64>* psymval,
1983                                       unsigned char* view,
1984                                       elfcpp::Elf_types<64>::Elf_Addr address,
1985                                       section_size_type view_size)
1986 {
1987   Output_segment* tls_segment = relinfo->layout->tls_segment();
1988
1989   const Sized_relobj<64, false>* object = relinfo->object;
1990   const elfcpp::Elf_Xword addend = rela.get_r_addend();
1991
1992   elfcpp::Elf_types<64>::Elf_Addr value = psymval->value(relinfo->object, 0);
1993
1994   const bool is_final = (gsym == NULL
1995                          ? !parameters->options().output_is_position_independent()
1996                          : gsym->final_value_is_known());
1997   const tls::Tls_optimization optimized_type
1998       = Target_x86_64::optimize_tls_reloc(is_final, r_type);
1999   switch (r_type)
2000     {
2001     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
2002       this->saw_tls_block_reloc_ = true;
2003       if (optimized_type == tls::TLSOPT_TO_LE)
2004         {
2005           gold_assert(tls_segment != NULL);
2006           this->tls_gd_to_le(relinfo, relnum, tls_segment,
2007                              rela, r_type, value, view,
2008                              view_size);
2009           break;
2010         }
2011       else
2012         {
2013           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
2014                                    ? GOT_TYPE_TLS_OFFSET
2015                                    : GOT_TYPE_TLS_PAIR);
2016           unsigned int got_offset;
2017           if (gsym != NULL)
2018             {
2019               gold_assert(gsym->has_got_offset(got_type));
2020               got_offset = gsym->got_offset(got_type) - target->got_size();
2021             }
2022           else
2023             {
2024               unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
2025               gold_assert(object->local_has_got_offset(r_sym, got_type));
2026               got_offset = (object->local_got_offset(r_sym, got_type)
2027                             - target->got_size());
2028             }
2029           if (optimized_type == tls::TLSOPT_TO_IE)
2030             {
2031               gold_assert(tls_segment != NULL);
2032               value = target->got_plt_section()->address() + got_offset;
2033               this->tls_gd_to_ie(relinfo, relnum, tls_segment, rela, r_type,
2034                                  value, view, address, view_size);
2035               break;
2036             }
2037           else if (optimized_type == tls::TLSOPT_NONE)
2038             {
2039               // Relocate the field with the offset of the pair of GOT
2040               // entries.
2041               value = target->got_plt_section()->address() + got_offset;
2042               Relocate_functions<64, false>::pcrela32(view, value, addend,
2043                                                       address);
2044               break;
2045             }
2046         }
2047       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
2048                              _("unsupported reloc %u"), r_type);
2049       break;
2050
2051     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
2052     case elfcpp::R_X86_64_TLSDESC_CALL:
2053       this->saw_tls_block_reloc_ = true;
2054       if (optimized_type == tls::TLSOPT_TO_LE)
2055         {
2056           gold_assert(tls_segment != NULL);
2057           this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
2058                                   rela, r_type, value, view,
2059                                   view_size);
2060           break;
2061         }
2062       else
2063         {
2064           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
2065                                    ? GOT_TYPE_TLS_OFFSET
2066                                    : GOT_TYPE_TLS_DESC);
2067           unsigned int got_offset;
2068           if (gsym != NULL)
2069             {
2070               gold_assert(gsym->has_got_offset(got_type));
2071               got_offset = gsym->got_offset(got_type) - target->got_size();
2072             }
2073           else
2074             {
2075               unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
2076               gold_assert(object->local_has_got_offset(r_sym, got_type));
2077               got_offset = (object->local_got_offset(r_sym, got_type)
2078                             - target->got_size());
2079             }
2080           if (optimized_type == tls::TLSOPT_TO_IE)
2081             {
2082               gold_assert(tls_segment != NULL);
2083               value = target->got_plt_section()->address() + got_offset;
2084               this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment,
2085                                       rela, r_type, value, view, address,
2086                                       view_size);
2087               break;
2088             }
2089           else if (optimized_type == tls::TLSOPT_NONE)
2090             {
2091               if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
2092                 {
2093                   // Relocate the field with the offset of the pair of GOT
2094                   // entries.
2095                   value = target->got_plt_section()->address() + got_offset;
2096                   Relocate_functions<64, false>::pcrela32(view, value, addend,
2097                                                           address);
2098                 }
2099               break;
2100             }
2101         }
2102       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
2103                              _("unsupported reloc %u"), r_type);
2104       break;
2105
2106     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
2107       this->saw_tls_block_reloc_ = true;
2108       if (optimized_type == tls::TLSOPT_TO_LE)
2109         {
2110           gold_assert(tls_segment != NULL);
2111           this->tls_ld_to_le(relinfo, relnum, tls_segment, rela, r_type,
2112                              value, view, view_size);
2113           break;
2114         }
2115       else if (optimized_type == tls::TLSOPT_NONE)
2116         {
2117           // Relocate the field with the offset of the GOT entry for
2118           // the module index.
2119           unsigned int got_offset;
2120           got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
2121                         - target->got_size());
2122           value = target->got_plt_section()->address() + got_offset;
2123           Relocate_functions<64, false>::pcrela32(view, value, addend,
2124                                                   address);
2125           break;
2126         }
2127       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
2128                              _("unsupported reloc %u"), r_type);
2129       break;
2130
2131     case elfcpp::R_X86_64_DTPOFF32:
2132       if (optimized_type == tls::TLSOPT_TO_LE)
2133         {
2134           // This relocation type is used in debugging information.
2135           // In that case we need to not optimize the value.  If we
2136           // haven't seen a TLSLD reloc, then we assume we should not
2137           // optimize this reloc.
2138           if (this->saw_tls_block_reloc_)
2139             {
2140               gold_assert(tls_segment != NULL);
2141               value -= tls_segment->memsz();
2142             }
2143         }
2144       Relocate_functions<64, false>::rela32(view, value, addend);
2145       break;
2146
2147     case elfcpp::R_X86_64_DTPOFF64:
2148       if (optimized_type == tls::TLSOPT_TO_LE)
2149         {
2150           // See R_X86_64_DTPOFF32, just above, for why we test this.
2151           if (this->saw_tls_block_reloc_)
2152             {
2153               gold_assert(tls_segment != NULL);
2154               value -= tls_segment->memsz();
2155             }
2156         }
2157       Relocate_functions<64, false>::rela64(view, value, addend);
2158       break;
2159
2160     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
2161       if (optimized_type == tls::TLSOPT_TO_LE)
2162         {
2163           gold_assert(tls_segment != NULL);
2164           Target_x86_64::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
2165                                                 rela, r_type, value, view,
2166                                                 view_size);
2167           break;
2168         }
2169       else if (optimized_type == tls::TLSOPT_NONE)
2170         {
2171           // Relocate the field with the offset of the GOT entry for
2172           // the tp-relative offset of the symbol.
2173           unsigned int got_offset;
2174           if (gsym != NULL)
2175             {
2176               gold_assert(gsym->has_got_offset(GOT_TYPE_TLS_OFFSET));
2177               got_offset = (gsym->got_offset(GOT_TYPE_TLS_OFFSET)
2178                             - target->got_size());
2179             }
2180           else
2181             {
2182               unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
2183               gold_assert(object->local_has_got_offset(r_sym,
2184                                                        GOT_TYPE_TLS_OFFSET));
2185               got_offset = (object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET)
2186                             - target->got_size());
2187             }
2188           value = target->got_plt_section()->address() + got_offset;
2189           Relocate_functions<64, false>::pcrela32(view, value, addend, address);
2190           break;
2191         }
2192       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
2193                              _("unsupported reloc type %u"),
2194                              r_type);
2195       break;
2196
2197     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
2198       value -= tls_segment->memsz();
2199       Relocate_functions<64, false>::rela32(view, value, addend);
2200       break;
2201     }
2202 }
2203
2204 // Do a relocation in which we convert a TLS General-Dynamic to an
2205 // Initial-Exec.
2206
2207 inline void
2208 Target_x86_64::Relocate::tls_gd_to_ie(const Relocate_info<64, false>* relinfo,
2209                                       size_t relnum,
2210                                       Output_segment*,
2211                                       const elfcpp::Rela<64, false>& rela,
2212                                       unsigned int,
2213                                       elfcpp::Elf_types<64>::Elf_Addr value,
2214                                       unsigned char* view,
2215                                       elfcpp::Elf_types<64>::Elf_Addr address,
2216                                       section_size_type view_size)
2217 {
2218   // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
2219   // .word 0x6666; rex64; call __tls_get_addr
2220   // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
2221
2222   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -4);
2223   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
2224
2225   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2226                  (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
2227   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2228                  (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0));
2229
2230   memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0", 16);
2231
2232   const elfcpp::Elf_Xword addend = rela.get_r_addend();
2233   Relocate_functions<64, false>::pcrela32(view + 8, value, addend - 8, address);
2234
2235   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2236   // We can skip it.
2237   this->skip_call_tls_get_addr_ = true;
2238 }
2239
2240 // Do a relocation in which we convert a TLS General-Dynamic to a
2241 // Local-Exec.
2242
2243 inline void
2244 Target_x86_64::Relocate::tls_gd_to_le(const Relocate_info<64, false>* relinfo,
2245                                       size_t relnum,
2246                                       Output_segment* tls_segment,
2247                                       const elfcpp::Rela<64, false>& rela,
2248                                       unsigned int,
2249                                       elfcpp::Elf_types<64>::Elf_Addr value,
2250                                       unsigned char* view,
2251                                       section_size_type view_size)
2252 {
2253   // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
2254   // .word 0x6666; rex64; call __tls_get_addr
2255   // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
2256
2257   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -4);
2258   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
2259
2260   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2261                  (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
2262   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2263                  (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0));
2264
2265   memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0", 16);
2266
2267   value -= tls_segment->memsz();
2268   Relocate_functions<64, false>::rela32(view + 8, value, 0);
2269
2270   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2271   // We can skip it.
2272   this->skip_call_tls_get_addr_ = true;
2273 }
2274
2275 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
2276
2277 inline void
2278 Target_x86_64::Relocate::tls_desc_gd_to_ie(
2279     const Relocate_info<64, false>* relinfo,
2280     size_t relnum,
2281     Output_segment*,
2282     const elfcpp::Rela<64, false>& rela,
2283     unsigned int r_type,
2284     elfcpp::Elf_types<64>::Elf_Addr value,
2285     unsigned char* view,
2286     elfcpp::Elf_types<64>::Elf_Addr address,
2287     section_size_type view_size)
2288 {
2289   if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
2290     {
2291       // leaq foo@tlsdesc(%rip), %rax
2292       // ==> movq foo@gottpoff(%rip), %rax
2293       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
2294       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
2295       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2296                      view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05);
2297       view[-2] = 0x8b;
2298       const elfcpp::Elf_Xword addend = rela.get_r_addend();
2299       Relocate_functions<64, false>::pcrela32(view, value, addend, address);
2300     }
2301   else
2302     {
2303       // call *foo@tlscall(%rax)
2304       // ==> nop; nop
2305       gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
2306       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
2307       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2308                      view[0] == 0xff && view[1] == 0x10);
2309       view[0] = 0x66;
2310       view[1] = 0x90;
2311     }
2312 }
2313
2314 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
2315
2316 inline void
2317 Target_x86_64::Relocate::tls_desc_gd_to_le(
2318     const Relocate_info<64, false>* relinfo,
2319     size_t relnum,
2320     Output_segment* tls_segment,
2321     const elfcpp::Rela<64, false>& rela,
2322     unsigned int r_type,
2323     elfcpp::Elf_types<64>::Elf_Addr value,
2324     unsigned char* view,
2325     section_size_type view_size)
2326 {
2327   if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
2328     {
2329       // leaq foo@tlsdesc(%rip), %rax
2330       // ==> movq foo@tpoff, %rax
2331       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
2332       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
2333       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2334                      view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05);
2335       view[-2] = 0xc7;
2336       view[-1] = 0xc0;
2337       value -= tls_segment->memsz();
2338       Relocate_functions<64, false>::rela32(view, value, 0);
2339     }
2340   else
2341     {
2342       // call *foo@tlscall(%rax)
2343       // ==> nop; nop
2344       gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
2345       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
2346       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2347                      view[0] == 0xff && view[1] == 0x10);
2348       view[0] = 0x66;
2349       view[1] = 0x90;
2350     }
2351 }
2352
2353 inline void
2354 Target_x86_64::Relocate::tls_ld_to_le(const Relocate_info<64, false>* relinfo,
2355                                       size_t relnum,
2356                                       Output_segment*,
2357                                       const elfcpp::Rela<64, false>& rela,
2358                                       unsigned int,
2359                                       elfcpp::Elf_types<64>::Elf_Addr,
2360                                       unsigned char* view,
2361                                       section_size_type view_size)
2362 {
2363   // leaq foo@tlsld(%rip),%rdi; call __tls_get_addr@plt;
2364   // ... leq foo@dtpoff(%rax),%reg
2365   // ==> .word 0x6666; .byte 0x66; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
2366
2367   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
2368   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 9);
2369
2370   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2371                  view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x3d);
2372
2373   tls::check_tls(relinfo, relnum, rela.get_r_offset(), view[4] == 0xe8);
2374
2375   memcpy(view - 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12);
2376
2377   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2378   // We can skip it.
2379   this->skip_call_tls_get_addr_ = true;
2380 }
2381
2382 // Do a relocation in which we convert a TLS Initial-Exec to a
2383 // Local-Exec.
2384
2385 inline void
2386 Target_x86_64::Relocate::tls_ie_to_le(const Relocate_info<64, false>* relinfo,
2387                                       size_t relnum,
2388                                       Output_segment* tls_segment,
2389                                       const elfcpp::Rela<64, false>& rela,
2390                                       unsigned int,
2391                                       elfcpp::Elf_types<64>::Elf_Addr value,
2392                                       unsigned char* view,
2393                                       section_size_type view_size)
2394 {
2395   // We need to examine the opcodes to figure out which instruction we
2396   // are looking at.
2397
2398   // movq foo@gottpoff(%rip),%reg  ==>  movq $YY,%reg
2399   // addq foo@gottpoff(%rip),%reg  ==>  addq $YY,%reg
2400
2401   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
2402   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
2403
2404   unsigned char op1 = view[-3];
2405   unsigned char op2 = view[-2];
2406   unsigned char op3 = view[-1];
2407   unsigned char reg = op3 >> 3;
2408
2409   if (op2 == 0x8b)
2410     {
2411       // movq
2412       if (op1 == 0x4c)
2413         view[-3] = 0x49;
2414       view[-2] = 0xc7;
2415       view[-1] = 0xc0 | reg;
2416     }
2417   else if (reg == 4)
2418     {
2419       // Special handling for %rsp.
2420       if (op1 == 0x4c)
2421         view[-3] = 0x49;
2422       view[-2] = 0x81;
2423       view[-1] = 0xc0 | reg;
2424     }
2425   else
2426     {
2427       // addq
2428       if (op1 == 0x4c)
2429         view[-3] = 0x4d;
2430       view[-2] = 0x8d;
2431       view[-1] = 0x80 | reg | (reg << 3);
2432     }
2433
2434   value -= tls_segment->memsz();
2435   Relocate_functions<64, false>::rela32(view, value, 0);
2436 }
2437
2438 // Relocate section data.
2439
2440 void
2441 Target_x86_64::relocate_section(
2442     const Relocate_info<64, false>* relinfo,
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     unsigned char* view,
2449     elfcpp::Elf_types<64>::Elf_Addr address,
2450     section_size_type view_size,
2451     const Reloc_symbol_changes* reloc_symbol_changes)
2452 {
2453   gold_assert(sh_type == elfcpp::SHT_RELA);
2454
2455   gold::relocate_section<64, false, Target_x86_64, elfcpp::SHT_RELA,
2456                          Target_x86_64::Relocate>(
2457     relinfo,
2458     this,
2459     prelocs,
2460     reloc_count,
2461     output_section,
2462     needs_special_offset_handling,
2463     view,
2464     address,
2465     view_size,
2466     reloc_symbol_changes);
2467 }
2468
2469 // Return the size of a relocation while scanning during a relocatable
2470 // link.
2471
2472 unsigned int
2473 Target_x86_64::Relocatable_size_for_reloc::get_size_for_reloc(
2474     unsigned int r_type,
2475     Relobj* object)
2476 {
2477   switch (r_type)
2478     {
2479     case elfcpp::R_X86_64_NONE:
2480     case elfcpp::R_386_GNU_VTINHERIT:
2481     case elfcpp::R_386_GNU_VTENTRY:
2482     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
2483     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
2484     case elfcpp::R_X86_64_TLSDESC_CALL:
2485     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
2486     case elfcpp::R_X86_64_DTPOFF32:
2487     case elfcpp::R_X86_64_DTPOFF64:
2488     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
2489     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
2490       return 0;
2491
2492     case elfcpp::R_X86_64_64:
2493     case elfcpp::R_X86_64_PC64:
2494     case elfcpp::R_X86_64_GOTOFF64:
2495     case elfcpp::R_X86_64_GOTPC64:
2496     case elfcpp::R_X86_64_PLTOFF64:
2497     case elfcpp::R_X86_64_GOT64:
2498     case elfcpp::R_X86_64_GOTPCREL64:
2499     case elfcpp::R_X86_64_GOTPCREL:
2500     case elfcpp::R_X86_64_GOTPLT64:
2501       return 8;
2502
2503     case elfcpp::R_X86_64_32:
2504     case elfcpp::R_X86_64_32S:
2505     case elfcpp::R_X86_64_PC32:
2506     case elfcpp::R_X86_64_PLT32:
2507     case elfcpp::R_X86_64_GOTPC32:
2508     case elfcpp::R_X86_64_GOT32:
2509       return 4;
2510
2511     case elfcpp::R_X86_64_16:
2512     case elfcpp::R_X86_64_PC16:
2513       return 2;
2514
2515     case elfcpp::R_X86_64_8:
2516     case elfcpp::R_X86_64_PC8:
2517       return 1;
2518
2519     case elfcpp::R_X86_64_COPY:
2520     case elfcpp::R_X86_64_GLOB_DAT:
2521     case elfcpp::R_X86_64_JUMP_SLOT:
2522     case elfcpp::R_X86_64_RELATIVE:
2523       // These are outstanding tls relocs, which are unexpected when linking
2524     case elfcpp::R_X86_64_TPOFF64:
2525     case elfcpp::R_X86_64_DTPMOD64:
2526     case elfcpp::R_X86_64_TLSDESC:
2527       object->error(_("unexpected reloc %u in object file"), r_type);
2528       return 0;
2529
2530     case elfcpp::R_X86_64_SIZE32:
2531     case elfcpp::R_X86_64_SIZE64:
2532     default:
2533       object->error(_("unsupported reloc %u against local symbol"), r_type);
2534       return 0;
2535     }
2536 }
2537
2538 // Scan the relocs during a relocatable link.
2539
2540 void
2541 Target_x86_64::scan_relocatable_relocs(Symbol_table* symtab,
2542                                        Layout* layout,
2543                                        Sized_relobj<64, false>* object,
2544                                        unsigned int data_shndx,
2545                                        unsigned int sh_type,
2546                                        const unsigned char* prelocs,
2547                                        size_t reloc_count,
2548                                        Output_section* output_section,
2549                                        bool needs_special_offset_handling,
2550                                        size_t local_symbol_count,
2551                                        const unsigned char* plocal_symbols,
2552                                        Relocatable_relocs* rr)
2553 {
2554   gold_assert(sh_type == elfcpp::SHT_RELA);
2555
2556   typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_RELA,
2557     Relocatable_size_for_reloc> Scan_relocatable_relocs;
2558
2559   gold::scan_relocatable_relocs<64, false, elfcpp::SHT_RELA,
2560       Scan_relocatable_relocs>(
2561     symtab,
2562     layout,
2563     object,
2564     data_shndx,
2565     prelocs,
2566     reloc_count,
2567     output_section,
2568     needs_special_offset_handling,
2569     local_symbol_count,
2570     plocal_symbols,
2571     rr);
2572 }
2573
2574 // Relocate a section during a relocatable link.
2575
2576 void
2577 Target_x86_64::relocate_for_relocatable(
2578     const Relocate_info<64, false>* relinfo,
2579     unsigned int sh_type,
2580     const unsigned char* prelocs,
2581     size_t reloc_count,
2582     Output_section* output_section,
2583     off_t offset_in_output_section,
2584     const Relocatable_relocs* rr,
2585     unsigned char* view,
2586     elfcpp::Elf_types<64>::Elf_Addr view_address,
2587     section_size_type view_size,
2588     unsigned char* reloc_view,
2589     section_size_type reloc_view_size)
2590 {
2591   gold_assert(sh_type == elfcpp::SHT_RELA);
2592
2593   gold::relocate_for_relocatable<64, false, elfcpp::SHT_RELA>(
2594     relinfo,
2595     prelocs,
2596     reloc_count,
2597     output_section,
2598     offset_in_output_section,
2599     rr,
2600     view,
2601     view_address,
2602     view_size,
2603     reloc_view,
2604     reloc_view_size);
2605 }
2606
2607 // Return the value to use for a dynamic which requires special
2608 // treatment.  This is how we support equality comparisons of function
2609 // pointers across shared library boundaries, as described in the
2610 // processor specific ABI supplement.
2611
2612 uint64_t
2613 Target_x86_64::do_dynsym_value(const Symbol* gsym) const
2614 {
2615   gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
2616   return this->plt_section()->address() + gsym->plt_offset();
2617 }
2618
2619 // Return a string used to fill a code section with nops to take up
2620 // the specified length.
2621
2622 std::string
2623 Target_x86_64::do_code_fill(section_size_type length) const
2624 {
2625   if (length >= 16)
2626     {
2627       // Build a jmpq instruction to skip over the bytes.
2628       unsigned char jmp[5];
2629       jmp[0] = 0xe9;
2630       elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
2631       return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
2632               + std::string(length - 5, '\0'));
2633     }
2634
2635   // Nop sequences of various lengths.
2636   const char nop1[1] = { 0x90 };                   // nop
2637   const char nop2[2] = { 0x66, 0x90 };             // xchg %ax %ax
2638   const char nop3[3] = { 0x0f, 0x1f, 0x00 };       // nop (%rax)
2639   const char nop4[4] = { 0x0f, 0x1f, 0x40, 0x00};  // nop 0(%rax)
2640   const char nop5[5] = { 0x0f, 0x1f, 0x44, 0x00,   // nop 0(%rax,%rax,1)
2641                          0x00 };
2642   const char nop6[6] = { 0x66, 0x0f, 0x1f, 0x44,   // nopw 0(%rax,%rax,1)
2643                          0x00, 0x00 };
2644   const char nop7[7] = { 0x0f, 0x1f, 0x80, 0x00,   // nopl 0L(%rax)
2645                          0x00, 0x00, 0x00 };
2646   const char nop8[8] = { 0x0f, 0x1f, 0x84, 0x00,   // nopl 0L(%rax,%rax,1)
2647                          0x00, 0x00, 0x00, 0x00 };
2648   const char nop9[9] = { 0x66, 0x0f, 0x1f, 0x84,   // nopw 0L(%rax,%rax,1)
2649                          0x00, 0x00, 0x00, 0x00,
2650                          0x00 };
2651   const char nop10[10] = { 0x66, 0x2e, 0x0f, 0x1f, // nopw %cs:0L(%rax,%rax,1)
2652                            0x84, 0x00, 0x00, 0x00,
2653                            0x00, 0x00 };
2654   const char nop11[11] = { 0x66, 0x66, 0x2e, 0x0f, // data16
2655                            0x1f, 0x84, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
2656                            0x00, 0x00, 0x00 };
2657   const char nop12[12] = { 0x66, 0x66, 0x66, 0x2e, // data16; data16
2658                            0x0f, 0x1f, 0x84, 0x00, // nopw %cs:0L(%rax,%rax,1)
2659                            0x00, 0x00, 0x00, 0x00 };
2660   const char nop13[13] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
2661                            0x2e, 0x0f, 0x1f, 0x84, // nopw %cs:0L(%rax,%rax,1)
2662                            0x00, 0x00, 0x00, 0x00,
2663                            0x00 };
2664   const char nop14[14] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
2665                            0x66, 0x2e, 0x0f, 0x1f, // data16
2666                            0x84, 0x00, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
2667                            0x00, 0x00 };
2668   const char nop15[15] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
2669                            0x66, 0x66, 0x2e, 0x0f, // data16; data16
2670                            0x1f, 0x84, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
2671                            0x00, 0x00, 0x00 };
2672
2673   const char* nops[16] = {
2674     NULL,
2675     nop1, nop2, nop3, nop4, nop5, nop6, nop7,
2676     nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
2677   };
2678
2679   return std::string(nops[length], length);
2680 }
2681
2682 // FNOFFSET in section SHNDX in OBJECT is the start of a function
2683 // compiled with -fstack-split.  The function calls non-stack-split
2684 // code.  We have to change the function so that it always ensures
2685 // that it has enough stack space to run some random function.
2686
2687 void
2688 Target_x86_64::do_calls_non_split(Relobj* object, unsigned int shndx,
2689                                   section_offset_type fnoffset,
2690                                   section_size_type fnsize,
2691                                   unsigned char* view,
2692                                   section_size_type view_size,
2693                                   std::string* from,
2694                                   std::string* to) const
2695 {
2696   // The function starts with a comparison of the stack pointer and a
2697   // field in the TCB.  This is followed by a jump.
2698
2699   // cmp %fs:NN,%rsp
2700   if (this->match_view(view, view_size, fnoffset, "\x64\x48\x3b\x24\x25", 5)
2701       && fnsize > 9)
2702     {
2703       // We will call __morestack if the carry flag is set after this
2704       // comparison.  We turn the comparison into an stc instruction
2705       // and some nops.
2706       view[fnoffset] = '\xf9';
2707       this->set_view_to_nop(view, view_size, fnoffset + 1, 8);
2708     }
2709   // lea NN(%rsp),%r10
2710   // lea NN(%rsp),%r11
2711   else if ((this->match_view(view, view_size, fnoffset,
2712                              "\x4c\x8d\x94\x24", 4)
2713             || this->match_view(view, view_size, fnoffset,
2714                                 "\x4c\x8d\x9c\x24", 4))
2715            && fnsize > 8)
2716     {
2717       // This is loading an offset from the stack pointer for a
2718       // comparison.  The offset is negative, so we decrease the
2719       // offset by the amount of space we need for the stack.  This
2720       // means we will avoid calling __morestack if there happens to
2721       // be plenty of space on the stack already.
2722       unsigned char* pval = view + fnoffset + 4;
2723       uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
2724       val -= parameters->options().split_stack_adjust_size();
2725       elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
2726     }
2727   else
2728     {
2729       if (!object->has_no_split_stack())
2730         object->error(_("failed to match split-stack sequence at "
2731                         "section %u offset %0zx"),
2732                       shndx, static_cast<size_t>(fnoffset));
2733       return;
2734     }
2735
2736   // We have to change the function so that it calls
2737   // __morestack_non_split instead of __morestack.  The former will
2738   // allocate additional stack space.
2739   *from = "__morestack";
2740   *to = "__morestack_non_split";
2741 }
2742
2743 // The selector for x86_64 object files.
2744
2745 class Target_selector_x86_64 : public Target_selector_freebsd
2746 {
2747 public:
2748   Target_selector_x86_64()
2749     : Target_selector_freebsd(elfcpp::EM_X86_64, 64, false, "elf64-x86-64",
2750                               "elf64-x86-64-freebsd")
2751   { }
2752
2753   Target*
2754   do_instantiate_target()
2755   { return new Target_x86_64(); }
2756
2757 };
2758
2759 Target_selector_x86_64 target_selector_x86_64;
2760
2761 } // End anonymous namespace.