gold/x86_64.cc

   1 // x86_64.cc -- x86_64 target support for gold.
   2
   3 // Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
   4 // Written by Ian Lance Taylor <iant@google.com>.
   5
   6 // This file is part of gold.
   7
   8 // This program is free software; you can redistribute it and/or modify
   9 // it under the terms of the GNU General Public License as published by
  10 // the Free Software Foundation; either version 3 of the License, or
  11 // (at your option) any later version.
  12
  13 // This program is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17
  18 // You should have received a copy of the GNU General Public License
  19 // along with this program; if not, write to the Free Software
  20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  21 // MA 02110-1301, USA.
  22
  23 #include "gold.h"
  24
  25 #include <cstring>
  26
  27 #include "elfcpp.h"
  28 #include "parameters.h"
  29 #include "reloc.h"
  30 #include "x86_64.h"
  31 #include "object.h"
  32 #include "symtab.h"
  33 #include "layout.h"
  34 #include "output.h"
  35 #include "copy-relocs.h"
  36 #include "target.h"
  37 #include "target-reloc.h"
  38 #include "target-select.h"
  39 #include "tls.h"
  40 #include "freebsd.h"
  41 #include "gc.h"
  42
  43 namespace
  44 {
  45
  46 using namespace gold;
  47
  48 class Output_data_plt_x86_64;
  49
  50 // The x86_64 target class.
  51 // See the ABI at
  52 //   http://www.x86-64.org/documentation/abi.pdf
  53 // TLS info comes from
  54 //   http://people.redhat.com/drepper/tls.pdf
  55 //   http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
  56
  57 class Target_x86_64 : public Target_freebsd<64, false>
  58 {
  59  public:
  60   // In the x86_64 ABI (p 68), it says "The AMD64 ABI architectures
  61   // uses only Elf64_Rela relocation entries with explicit addends."
  62   typedef Output_data_reloc<elfcpp::SHT_RELA, true, 64, false> Reloc_section;
  63
  64   Target_x86_64()
  65     : Target_freebsd<64, false>(&x86_64_info),
  66       got_(NULL), plt_(NULL), got_plt_(NULL), rela_dyn_(NULL),
  67       copy_relocs_(elfcpp::R_X86_64_COPY), dynbss_(NULL),
  68       got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
  69   { }
  70
  71   // Hook for a new output section.
  72   void
  73   do_new_output_section(Output_section*) const;
  74
  75   // Scan the relocations to look for symbol adjustments.
  76   void
  77   gc_process_relocs(Symbol_table* symtab,
  78                     Layout* layout,
  79                     Sized_relobj<64, false>* object,
  80                     unsigned int data_shndx,
  81                     unsigned int sh_type,
  82                     const unsigned char* prelocs,
  83                     size_t reloc_count,
  84                     Output_section* output_section,
  85                     bool needs_special_offset_handling,
  86                     size_t local_symbol_count,
  87                     const unsigned char* plocal_symbols);
  88
  89   // Scan the relocations to look for symbol adjustments.
  90   void
  91   scan_relocs(Symbol_table* symtab,
  92               Layout* layout,
  93               Sized_relobj<64, false>* object,
  94               unsigned int data_shndx,
  95               unsigned int sh_type,
  96               const unsigned char* prelocs,
  97               size_t reloc_count,
  98               Output_section* output_section,
  99               bool needs_special_offset_handling,
 100               size_t local_symbol_count,
 101               const unsigned char* plocal_symbols);
 102
 103   // Finalize the sections.
 104   void
 105   do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
 106
 107   // Return the value to use for a dynamic which requires special
 108   // treatment.
 109   uint64_t
 110   do_dynsym_value(const Symbol*) const;
 111
 112   // Relocate a section.
 113   void
 114   relocate_section(const Relocate_info<64, false>*,
 115                    unsigned int sh_type,
 116                    const unsigned char* prelocs,
 117                    size_t reloc_count,
 118                    Output_section* output_section,
 119                    bool needs_special_offset_handling,
 120                    unsigned char* view,
 121                    elfcpp::Elf_types<64>::Elf_Addr view_address,
 122                    section_size_type view_size,
 123                    const Reloc_symbol_changes*);
 124
 125   // Scan the relocs during a relocatable link.
 126   void
 127   scan_relocatable_relocs(Symbol_table* symtab,
 128                           Layout* layout,
 129                           Sized_relobj<64, false>* object,
 130                           unsigned int data_shndx,
 131                           unsigned int sh_type,
 132                           const unsigned char* prelocs,
 133                           size_t reloc_count,
 134                           Output_section* output_section,
 135                           bool needs_special_offset_handling,
 136                           size_t local_symbol_count,
 137                           const unsigned char* plocal_symbols,
 138                           Relocatable_relocs*);
 139
 140   // Relocate a section during a relocatable link.
 141   void
 142   relocate_for_relocatable(const Relocate_info<64, false>*,
 143                            unsigned int sh_type,
 144                            const unsigned char* prelocs,
 145                            size_t reloc_count,
 146                            Output_section* output_section,
 147                            off_t offset_in_output_section,
 148                            const Relocatable_relocs*,
 149                            unsigned char* view,
 150                            elfcpp::Elf_types<64>::Elf_Addr view_address,
 151                            section_size_type view_size,
 152                            unsigned char* reloc_view,
 153                            section_size_type reloc_view_size);
 154
 155   // Return a string used to fill a code section with nops.
 156   std::string
 157   do_code_fill(section_size_type length) const;
 158
 159   // Return whether SYM is defined by the ABI.
 160   bool
 161   do_is_defined_by_abi(const Symbol* sym) const
 162   { return strcmp(sym->name(), "__tls_get_addr") == 0; }
 163
 164   // Adjust -fstack-split code which calls non-stack-split code.
 165   void
 166   do_calls_non_split(Relobj* object, unsigned int shndx,
 167                      section_offset_type fnoffset, section_size_type fnsize,
 168                      unsigned char* view, section_size_type view_size,
 169                      std::string* from, std::string* to) const;
 170
 171   // Return the size of the GOT section.
 172   section_size_type
 173   got_size()
 174   {
 175     gold_assert(this->got_ != NULL);
 176     return this->got_->data_size();
 177   }
 178
 179  private:
 180   // The class which scans relocations.
 181   class Scan
 182   {
 183   public:
 184     Scan()
 185       : issued_non_pic_error_(false)
 186     { }
 187
 188     inline void
 189     local(Symbol_table* symtab, Layout* layout, Target_x86_64* target,
 190           Sized_relobj<64, false>* object,
 191           unsigned int data_shndx,
 192           Output_section* output_section,
 193           const elfcpp::Rela<64, false>& reloc, unsigned int r_type,
 194           const elfcpp::Sym<64, false>& lsym);
 195
 196     inline void
 197     global(Symbol_table* symtab, Layout* layout, Target_x86_64* target,
 198            Sized_relobj<64, false>* object,
 199            unsigned int data_shndx,
 200            Output_section* output_section,
 201            const elfcpp::Rela<64, false>& reloc, unsigned int r_type,
 202            Symbol* gsym);
 203
 204   private:
 205     static void
 206     unsupported_reloc_local(Sized_relobj<64, false>*, unsigned int r_type);
 207
 208     static void
 209     unsupported_reloc_global(Sized_relobj<64, false>*, unsigned int r_type,
 210                              Symbol*);
 211
 212     void
 213     check_non_pic(Relobj*, unsigned int r_type);
 214
 215     // Whether we have issued an error about a non-PIC compilation.
 216     bool issued_non_pic_error_;
 217   };
 218
 219   // The class which implements relocation.
 220   class Relocate
 221   {
 222    public:
 223     Relocate()
 224       : skip_call_tls_get_addr_(false), saw_tls_block_reloc_(false)
 225     { }
 226
 227     ~Relocate()
 228     {
 229       if (this->skip_call_tls_get_addr_)
 230         {
 231           // FIXME: This needs to specify the location somehow.
 232           gold_error(_("missing expected TLS relocation"));
 233         }
 234     }
 235
 236     // Do a relocation.  Return false if the caller should not issue
 237     // any warnings about this relocation.
 238     inline bool
 239     relocate(const Relocate_info<64, false>*, Target_x86_64*, Output_section*,
 240              size_t relnum, const elfcpp::Rela<64, false>&,
 241              unsigned int r_type, const Sized_symbol<64>*,
 242              const Symbol_value<64>*,
 243              unsigned char*, elfcpp::Elf_types<64>::Elf_Addr,
 244              section_size_type);
 245
 246    private:
 247     // Do a TLS relocation.
 248     inline void
 249     relocate_tls(const Relocate_info<64, false>*, Target_x86_64*,
 250                  size_t relnum, const elfcpp::Rela<64, false>&,
 251                  unsigned int r_type, const Sized_symbol<64>*,
 252                  const Symbol_value<64>*,
 253                  unsigned char*, elfcpp::Elf_types<64>::Elf_Addr,
 254                  section_size_type);
 255
 256     // Do a TLS General-Dynamic to Initial-Exec transition.
 257     inline void
 258     tls_gd_to_ie(const Relocate_info<64, false>*, size_t relnum,
 259                  Output_segment* tls_segment,
 260                  const elfcpp::Rela<64, false>&, unsigned int r_type,
 261                  elfcpp::Elf_types<64>::Elf_Addr value,
 262                  unsigned char* view,
 263                  elfcpp::Elf_types<64>::Elf_Addr,
 264                  section_size_type view_size);
 265
 266     // Do a TLS General-Dynamic to Local-Exec transition.
 267     inline void
 268     tls_gd_to_le(const Relocate_info<64, false>*, size_t relnum,
 269                  Output_segment* tls_segment,
 270                  const elfcpp::Rela<64, false>&, unsigned int r_type,
 271                  elfcpp::Elf_types<64>::Elf_Addr value,
 272                  unsigned char* view,
 273                  section_size_type view_size);
 274
 275     // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
 276     inline void
 277     tls_desc_gd_to_ie(const Relocate_info<64, false>*, size_t relnum,
 278                       Output_segment* tls_segment,
 279                       const elfcpp::Rela<64, false>&, unsigned int r_type,
 280                       elfcpp::Elf_types<64>::Elf_Addr value,
 281                       unsigned char* view,
 282                       elfcpp::Elf_types<64>::Elf_Addr,
 283                       section_size_type view_size);
 284
 285     // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
 286     inline void
 287     tls_desc_gd_to_le(const Relocate_info<64, false>*, size_t relnum,
 288                       Output_segment* tls_segment,
 289                       const elfcpp::Rela<64, false>&, unsigned int r_type,
 290                       elfcpp::Elf_types<64>::Elf_Addr value,
 291                       unsigned char* view,
 292                       section_size_type view_size);
 293
 294     // Do a TLS Local-Dynamic to Local-Exec transition.
 295     inline void
 296     tls_ld_to_le(const Relocate_info<64, false>*, size_t relnum,
 297                  Output_segment* tls_segment,
 298                  const elfcpp::Rela<64, false>&, unsigned int r_type,
 299                  elfcpp::Elf_types<64>::Elf_Addr value,
 300                  unsigned char* view,
 301                  section_size_type view_size);
 302
 303     // Do a TLS Initial-Exec to Local-Exec transition.
 304     static inline void
 305     tls_ie_to_le(const Relocate_info<64, false>*, size_t relnum,
 306                  Output_segment* tls_segment,
 307                  const elfcpp::Rela<64, false>&, unsigned int r_type,
 308                  elfcpp::Elf_types<64>::Elf_Addr value,
 309                  unsigned char* view,
 310                  section_size_type view_size);
 311
 312     // This is set if we should skip the next reloc, which should be a
 313     // PLT32 reloc against ___tls_get_addr.
 314     bool skip_call_tls_get_addr_;
 315
 316     // This is set if we see a relocation which could load the address
 317     // of the TLS block.  Whether we see such a relocation determines
 318     // how we handle the R_X86_64_DTPOFF32 relocation, which is used
 319     // in debugging sections.
 320     bool saw_tls_block_reloc_;
 321   };
 322
 323   // A class which returns the size required for a relocation type,
 324   // used while scanning relocs during a relocatable link.
 325   class Relocatable_size_for_reloc
 326   {
 327    public:
 328     unsigned int
 329     get_size_for_reloc(unsigned int, Relobj*);
 330   };
 331
 332   // Adjust TLS relocation type based on the options and whether this
 333   // is a local symbol.
 334   static tls::Tls_optimization
 335   optimize_tls_reloc(bool is_final, int r_type);
 336
 337   // Get the GOT section, creating it if necessary.
 338   Output_data_got<64, false>*
 339   got_section(Symbol_table*, Layout*);
 340
 341   // Get the GOT PLT section.
 342   Output_data_space*
 343   got_plt_section() const
 344   {
 345     gold_assert(this->got_plt_ != NULL);
 346     return this->got_plt_;
 347   }
 348
 349   // Create the PLT section.
 350   void
 351   make_plt_section(Symbol_table* symtab, Layout* layout);
 352
 353   // Create a PLT entry for a global symbol.
 354   void
 355   make_plt_entry(Symbol_table*, Layout*, Symbol*);
 356
 357   // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
 358   void
 359   define_tls_base_symbol(Symbol_table*, Layout*);
 360
 361   // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
 362   void
 363   reserve_tlsdesc_entries(Symbol_table* symtab, Layout* layout);
 364
 365   // Create a GOT entry for the TLS module index.
 366   unsigned int
 367   got_mod_index_entry(Symbol_table* symtab, Layout* layout,
 368                       Sized_relobj<64, false>* object);
 369
 370   // Get the PLT section.
 371   Output_data_plt_x86_64*
 372   plt_section() const
 373   {
 374     gold_assert(this->plt_ != NULL);
 375     return this->plt_;
 376   }
 377
 378   // Get the dynamic reloc section, creating it if necessary.
 379   Reloc_section*
 380   rela_dyn_section(Layout*);
 381
 382   // Add a potential copy relocation.
 383   void
 384   copy_reloc(Symbol_table* symtab, Layout* layout,
 385              Sized_relobj<64, false>* object,
 386              unsigned int shndx, Output_section* output_section,
 387              Symbol* sym, const elfcpp::Rela<64, false>& reloc)
 388   {
 389     this->copy_relocs_.copy_reloc(symtab, layout,
 390                                   symtab->get_sized_symbol<64>(sym),
 391                                   object, shndx, output_section,
 392                                   reloc, this->rela_dyn_section(layout));
 393   }
 394
 395   // Information about this specific target which we pass to the
 396   // general Target structure.
 397   static const Target::Target_info x86_64_info;
 398
 399   enum Got_type
 400   {
 401     GOT_TYPE_STANDARD = 0,      // GOT entry for a regular symbol
 402     GOT_TYPE_TLS_OFFSET = 1,    // GOT entry for TLS offset
 403     GOT_TYPE_TLS_PAIR = 2,      // GOT entry for TLS module/offset pair
 404     GOT_TYPE_TLS_DESC = 3       // GOT entry for TLS_DESC pair
 405   };
 406
 407   // The GOT section.
 408   Output_data_got<64, false>* got_;
 409   // The PLT section.
 410   Output_data_plt_x86_64* plt_;
 411   // The GOT PLT section.
 412   Output_data_space* got_plt_;
 413   // The dynamic reloc section.
 414   Reloc_section* rela_dyn_;
 415   // Relocs saved to avoid a COPY reloc.
 416   Copy_relocs<elfcpp::SHT_RELA, 64, false> copy_relocs_;
 417   // Space for variables copied with a COPY reloc.
 418   Output_data_space* dynbss_;
 419   // Offset of the GOT entry for the TLS module index.
 420   unsigned int got_mod_index_offset_;
 421   // True if the _TLS_MODULE_BASE_ symbol has been defined.
 422   bool tls_base_symbol_defined_;
 423 };
 424
 425 const Target::Target_info Target_x86_64::x86_64_info =
 426 {
 427   64,                   // size
 428   false,                // is_big_endian
 429   elfcpp::EM_X86_64,    // machine_code
 430   false,                // has_make_symbol
 431   false,                // has_resolve
 432   true,                 // has_code_fill
 433   true,                 // is_default_stack_executable
 434   '\0',                 // wrap_char
 435   "/lib/ld64.so.1",     // program interpreter
 436   0x400000,             // default_text_segment_address
 437   0x1000,               // abi_pagesize (overridable by -z max-page-size)
 438   0x1000,               // common_pagesize (overridable by -z common-page-size)
 439   elfcpp::SHN_UNDEF,    // small_common_shndx
 440   elfcpp::SHN_X86_64_LCOMMON,   // large_common_shndx
 441   0,                    // small_common_section_flags
 442   elfcpp::SHF_X86_64_LARGE,     // large_common_section_flags
 443   NULL,                 // attributes_section
 444   NULL                  // attributes_vendor
 445 };
 446
 447 // This is called when a new output section is created.  This is where
 448 // we handle the SHF_X86_64_LARGE.
 449
 450 void
 451 Target_x86_64::do_new_output_section(Output_section *os) const
 452 {
 453   if ((os->flags() & elfcpp::SHF_X86_64_LARGE) != 0)
 454     os->set_is_large_section();
 455 }
 456
 457 // Get the GOT section, creating it if necessary.
 458
 459 Output_data_got<64, false>*
 460 Target_x86_64::got_section(Symbol_table* symtab, Layout* layout)
 461 {
 462   if (this->got_ == NULL)
 463     {
 464       gold_assert(symtab != NULL && layout != NULL);
 465
 466       this->got_ = new Output_data_got<64, false>();
 467
 468       Output_section* os;
 469       os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
 470                                            (elfcpp::SHF_ALLOC
 471                                             | elfcpp::SHF_WRITE),
 472                                            this->got_, false, true, true,
 473                                            false);
 474
 475       this->got_plt_ = new Output_data_space(8, "** GOT PLT");
 476       os = layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
 477                                            (elfcpp::SHF_ALLOC
 478                                             | elfcpp::SHF_WRITE),
 479                                            this->got_plt_, false, false,
 480                                            false, true);
 481
 482       // The first three entries are reserved.
 483       this->got_plt_->set_current_data_size(3 * 8);
 484
 485       // Those bytes can go into the relro segment.
 486       layout->increase_relro(3 * 8);
 487
 488       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
 489       symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
 490                                     Symbol_table::PREDEFINED,
 491                                     this->got_plt_,
 492                                     0, 0, elfcpp::STT_OBJECT,
 493                                     elfcpp::STB_LOCAL,
 494                                     elfcpp::STV_HIDDEN, 0,
 495                                     false, false);
 496     }
 497
 498   return this->got_;
 499 }
 500
 501 // Get the dynamic reloc section, creating it if necessary.
 502
 503 Target_x86_64::Reloc_section*
 504 Target_x86_64::rela_dyn_section(Layout* layout)
 505 {
 506   if (this->rela_dyn_ == NULL)
 507     {
 508       gold_assert(layout != NULL);
 509       this->rela_dyn_ = new Reloc_section(parameters->options().combreloc());
 510       layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
 511                                       elfcpp::SHF_ALLOC, this->rela_dyn_, true,
 512                                       false, false, false);
 513     }
 514   return this->rela_dyn_;
 515 }
 516
 517 // A class to handle the PLT data.
 518
 519 class Output_data_plt_x86_64 : public Output_section_data
 520 {
 521  public:
 522   typedef Output_data_reloc<elfcpp::SHT_RELA, true, 64, false> Reloc_section;
 523
 524   Output_data_plt_x86_64(Layout*, Output_data_got<64, false>*,
 525                          Output_data_space*);
 526
 527   // Add an entry to the PLT.
 528   void
 529   add_entry(Symbol* gsym);
 530
 531   // Add the reserved TLSDESC_PLT entry to the PLT.
 532   void
 533   reserve_tlsdesc_entry(unsigned int got_offset)
 534   { this->tlsdesc_got_offset_ = got_offset; }
 535
 536   // Return true if a TLSDESC_PLT entry has been reserved.
 537   bool
 538   has_tlsdesc_entry() const
 539   { return this->tlsdesc_got_offset_ != -1U; }
 540
 541   // Return the GOT offset for the reserved TLSDESC_PLT entry.
 542   unsigned int
 543   get_tlsdesc_got_offset() const
 544   { return this->tlsdesc_got_offset_; }
 545
 546   // Return the offset of the reserved TLSDESC_PLT entry.
 547   unsigned int
 548   get_tlsdesc_plt_offset() const
 549   { return (this->count_ + 1) * plt_entry_size; }
 550
 551   // Return the .rel.plt section data.
 552   const Reloc_section*
 553   rel_plt() const
 554   { return this->rel_; }
 555
 556  protected:
 557   void
 558   do_adjust_output_section(Output_section* os);
 559
 560   // Write to a map file.
 561   void
 562   do_print_to_mapfile(Mapfile* mapfile) const
 563   { mapfile->print_output_data(this, _("** PLT")); }
 564
 565  private:
 566   // The size of an entry in the PLT.
 567   static const int plt_entry_size = 16;
 568
 569   // The first entry in the PLT.
 570   // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
 571   // procedure linkage table for both programs and shared objects."
 572   static unsigned char first_plt_entry[plt_entry_size];
 573
 574   // Other entries in the PLT for an executable.
 575   static unsigned char plt_entry[plt_entry_size];
 576
 577   // The reserved TLSDESC entry in the PLT for an executable.
 578   static unsigned char tlsdesc_plt_entry[plt_entry_size];
 579
 580   // Set the final size.
 581   void
 582   set_final_data_size();
 583
 584   // Write out the PLT data.
 585   void
 586   do_write(Output_file*);
 587
 588   // The reloc section.
 589   Reloc_section* rel_;
 590   // The .got section.
 591   Output_data_got<64, false>* got_;
 592   // The .got.plt section.
 593   Output_data_space* got_plt_;
 594   // The number of PLT entries.
 595   unsigned int count_;
 596   // Offset of the reserved TLSDESC_GOT entry when needed.
 597   unsigned int tlsdesc_got_offset_;
 598 };
 599
 600 // Create the PLT section.  The ordinary .got section is an argument,
 601 // since we need to refer to the start.  We also create our own .got
 602 // section just for PLT entries.
 603
 604 Output_data_plt_x86_64::Output_data_plt_x86_64(Layout* layout,
 605                                                Output_data_got<64, false>* got,
 606                                                Output_data_space* got_plt)
 607   : Output_section_data(8), got_(got), got_plt_(got_plt), count_(0),
 608     tlsdesc_got_offset_(-1U)
 609 {
 610   this->rel_ = new Reloc_section(false);
 611   layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
 612                                   elfcpp::SHF_ALLOC, this->rel_, true,
 613                                   false, false, false);
 614 }
 615
 616 void
 617 Output_data_plt_x86_64::do_adjust_output_section(Output_section* os)
 618 {
 619   os->set_entsize(plt_entry_size);
 620 }
 621
 622 // Add an entry to the PLT.
 623
 624 void
 625 Output_data_plt_x86_64::add_entry(Symbol* gsym)
 626 {
 627   gold_assert(!gsym->has_plt_offset());
 628
 629   // Note that when setting the PLT offset we skip the initial
 630   // reserved PLT entry.
 631   gsym->set_plt_offset((this->count_ + 1) * plt_entry_size);
 632
 633   ++this->count_;
 634
 635   section_offset_type got_offset = this->got_plt_->current_data_size();
 636
 637   // Every PLT entry needs a GOT entry which points back to the PLT
 638   // entry (this will be changed by the dynamic linker, normally
 639   // lazily when the function is called).
 640   this->got_plt_->set_current_data_size(got_offset + 8);
 641
 642   // Every PLT entry needs a reloc.
 643   gsym->set_needs_dynsym_entry();
 644   this->rel_->add_global(gsym, elfcpp::R_X86_64_JUMP_SLOT, this->got_plt_,
 645                          got_offset, 0);
 646
 647   // Note that we don't need to save the symbol.  The contents of the
 648   // PLT are independent of which symbols are used.  The symbols only
 649   // appear in the relocations.
 650 }
 651
 652 // Set the final size.
 653 void
 654 Output_data_plt_x86_64::set_final_data_size()
 655 {
 656   unsigned int count = this->count_;
 657   if (this->has_tlsdesc_entry())
 658     ++count;
 659   this->set_data_size((count + 1) * plt_entry_size);
 660 }
 661
 662 // The first entry in the PLT for an executable.
 663
 664 unsigned char Output_data_plt_x86_64::first_plt_entry[plt_entry_size] =
 665 {
 666   // From AMD64 ABI Draft 0.98, page 76
 667   0xff, 0x35,   // pushq contents of memory address
 668   0, 0, 0, 0,   // replaced with address of .got + 8
 669   0xff, 0x25,   // jmp indirect
 670   0, 0, 0, 0,   // replaced with address of .got + 16
 671   0x90, 0x90, 0x90, 0x90   // noop (x4)
 672 };
 673
 674 // Subsequent entries in the PLT for an executable.
 675
 676 unsigned char Output_data_plt_x86_64::plt_entry[plt_entry_size] =
 677 {
 678   // From AMD64 ABI Draft 0.98, page 76
 679   0xff, 0x25,   // jmpq indirect
 680   0, 0, 0, 0,   // replaced with address of symbol in .got
 681   0x68,         // pushq immediate
 682   0, 0, 0, 0,   // replaced with offset into relocation table
 683   0xe9,         // jmpq relative
 684   0, 0, 0, 0    // replaced with offset to start of .plt
 685 };
 686
 687 // The reserved TLSDESC entry in the PLT for an executable.
 688
 689 unsigned char Output_data_plt_x86_64::tlsdesc_plt_entry[plt_entry_size] =
 690 {
 691   // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
 692   // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
 693   0xff, 0x35,   // pushq x(%rip)
 694   0, 0, 0, 0,   // replaced with address of linkmap GOT entry (at PLTGOT + 8)
 695   0xff, 0x25,   // jmpq *y(%rip)
 696   0, 0, 0, 0,   // replaced with offset of reserved TLSDESC_GOT entry
 697   0x0f, 0x1f,   // nop
 698   0x40, 0
 699 };
 700
 701 // Write out the PLT.  This uses the hand-coded instructions above,
 702 // and adjusts them as needed.  This is specified by the AMD64 ABI.
 703
 704 void
 705 Output_data_plt_x86_64::do_write(Output_file* of)
 706 {
 707   const off_t offset = this->offset();
 708   const section_size_type oview_size =
 709     convert_to_section_size_type(this->data_size());
 710   unsigned char* const oview = of->get_output_view(offset, oview_size);
 711
 712   const off_t got_file_offset = this->got_plt_->offset();
 713   const section_size_type got_size =
 714     convert_to_section_size_type(this->got_plt_->data_size());
 715   unsigned char* const got_view = of->get_output_view(got_file_offset,
 716                                                       got_size);
 717
 718   unsigned char* pov = oview;
 719
 720   // The base address of the .plt section.
 721   elfcpp::Elf_types<64>::Elf_Addr plt_address = this->address();
 722   // The base address of the .got section.
 723   elfcpp::Elf_types<64>::Elf_Addr got_base = this->got_->address();
 724   // The base address of the PLT portion of the .got section,
 725   // which is where the GOT pointer will point, and where the
 726   // three reserved GOT entries are located.
 727   elfcpp::Elf_types<64>::Elf_Addr got_address = this->got_plt_->address();
 728
 729   memcpy(pov, first_plt_entry, plt_entry_size);
 730   // We do a jmp relative to the PC at the end of this instruction.
 731   elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
 732                                               (got_address + 8
 733                                                - (plt_address + 6)));
 734   elfcpp::Swap<32, false>::writeval(pov + 8,
 735                                     (got_address + 16
 736                                      - (plt_address + 12)));
 737   pov += plt_entry_size;
 738
 739   unsigned char* got_pov = got_view;
 740
 741   memset(got_pov, 0, 24);
 742   got_pov += 24;
 743
 744   unsigned int plt_offset = plt_entry_size;
 745   unsigned int got_offset = 24;
 746   const unsigned int count = this->count_;
 747   for (unsigned int plt_index = 0;
 748        plt_index < count;
 749        ++plt_index,
 750          pov += plt_entry_size,
 751          got_pov += 8,
 752          plt_offset += plt_entry_size,
 753          got_offset += 8)
 754     {
 755       // Set and adjust the PLT entry itself.
 756       memcpy(pov, plt_entry, plt_entry_size);
 757       elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
 758                                                   (got_address + got_offset
 759                                                    - (plt_address + plt_offset
 760                                                       + 6)));
 761
 762       elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_index);
 763       elfcpp::Swap<32, false>::writeval(pov + 12,
 764                                         - (plt_offset + plt_entry_size));
 765
 766       // Set the entry in the GOT.
 767       elfcpp::Swap<64, false>::writeval(got_pov, plt_address + plt_offset + 6);
 768     }
 769
 770   if (this->has_tlsdesc_entry())
 771     {
 772       // Set and adjust the reserved TLSDESC PLT entry.
 773       unsigned int tlsdesc_got_offset = this->get_tlsdesc_got_offset();
 774       memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
 775       elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
 776                                                   (got_address + 8
 777                                                    - (plt_address + plt_offset
 778                                                       + 6)));
 779       elfcpp::Swap_unaligned<32, false>::writeval(pov + 8,
 780                                                   (got_base
 781                                                    + tlsdesc_got_offset
 782                                                    - (plt_address + plt_offset
 783                                                       + 12)));
 784       pov += plt_entry_size;
 785     }
 786
 787   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
 788   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
 789
 790   of->write_output_view(offset, oview_size, oview);
 791   of->write_output_view(got_file_offset, got_size, got_view);
 792 }
 793
 794 // Create the PLT section.
 795
 796 void
 797 Target_x86_64::make_plt_section(Symbol_table* symtab, Layout* layout)
 798 {
 799   if (this->plt_ == NULL)
 800     {
 801       // Create the GOT sections first.
 802       this->got_section(symtab, layout);
 803
 804       this->plt_ = new Output_data_plt_x86_64(layout, this->got_,
 805                                               this->got_plt_);
 806       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
 807                                       (elfcpp::SHF_ALLOC
 808                                        | elfcpp::SHF_EXECINSTR),
 809                                       this->plt_, false, false, false, false);
 810     }
 811 }
 812
 813 // Create a PLT entry for a global symbol.
 814
 815 void
 816 Target_x86_64::make_plt_entry(Symbol_table* symtab, Layout* layout,
 817                               Symbol* gsym)
 818 {
 819   if (gsym->has_plt_offset())
 820     return;
 821
 822   if (this->plt_ == NULL)
 823     this->make_plt_section(symtab, layout);
 824
 825   this->plt_->add_entry(gsym);
 826 }
 827
 828 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
 829
 830 void
 831 Target_x86_64::define_tls_base_symbol(Symbol_table* symtab, Layout* layout)
 832 {
 833   if (this->tls_base_symbol_defined_)
 834     return;
 835
 836   Output_segment* tls_segment = layout->tls_segment();
 837   if (tls_segment != NULL)
 838     {
 839       bool is_exec = parameters->options().output_is_executable();
 840       symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
 841                                        Symbol_table::PREDEFINED,
 842                                        tls_segment, 0, 0,
 843                                        elfcpp::STT_TLS,
 844                                        elfcpp::STB_LOCAL,
 845                                        elfcpp::STV_HIDDEN, 0,
 846                                        (is_exec
 847                                         ? Symbol::SEGMENT_END
 848                                         : Symbol::SEGMENT_START),
 849                                        true);
 850     }
 851   this->tls_base_symbol_defined_ = true;
 852 }
 853
 854 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
 855
 856 void
 857 Target_x86_64::reserve_tlsdesc_entries(Symbol_table* symtab,
 858                                              Layout* layout)
 859 {
 860   if (this->plt_ == NULL)
 861     this->make_plt_section(symtab, layout);
 862
 863   if (!this->plt_->has_tlsdesc_entry())
 864     {
 865       // Allocate the TLSDESC_GOT entry.
 866       Output_data_got<64, false>* got = this->got_section(symtab, layout);
 867       unsigned int got_offset = got->add_constant(0);
 868
 869       // Allocate the TLSDESC_PLT entry.
 870       this->plt_->reserve_tlsdesc_entry(got_offset);
 871     }
 872 }
 873
 874 // Create a GOT entry for the TLS module index.
 875
 876 unsigned int
 877 Target_x86_64::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
 878                                    Sized_relobj<64, false>* object)
 879 {
 880   if (this->got_mod_index_offset_ == -1U)
 881     {
 882       gold_assert(symtab != NULL && layout != NULL && object != NULL);
 883       Reloc_section* rela_dyn = this->rela_dyn_section(layout);
 884       Output_data_got<64, false>* got = this->got_section(symtab, layout);
 885       unsigned int got_offset = got->add_constant(0);
 886       rela_dyn->add_local(object, 0, elfcpp::R_X86_64_DTPMOD64, got,
 887                           got_offset, 0);
 888       got->add_constant(0);
 889       this->got_mod_index_offset_ = got_offset;
 890     }
 891   return this->got_mod_index_offset_;
 892 }
 893
 894 // Optimize the TLS relocation type based on what we know about the
 895 // symbol.  IS_FINAL is true if the final address of this symbol is
 896 // known at link time.
 897
 898 tls::Tls_optimization
 899 Target_x86_64::optimize_tls_reloc(bool is_final, int r_type)
 900 {
 901   // If we are generating a shared library, then we can't do anything
 902   // in the linker.
 903   if (parameters->options().shared())
 904     return tls::TLSOPT_NONE;
 905
 906   switch (r_type)
 907     {
 908     case elfcpp::R_X86_64_TLSGD:
 909     case elfcpp::R_X86_64_GOTPC32_TLSDESC:
 910     case elfcpp::R_X86_64_TLSDESC_CALL:
 911       // These are General-Dynamic which permits fully general TLS
 912       // access.  Since we know that we are generating an executable,
 913       // we can convert this to Initial-Exec.  If we also know that
 914       // this is a local symbol, we can further switch to Local-Exec.
 915       if (is_final)
 916         return tls::TLSOPT_TO_LE;
 917       return tls::TLSOPT_TO_IE;
 918
 919     case elfcpp::R_X86_64_TLSLD:
 920       // This is Local-Dynamic, which refers to a local symbol in the
 921       // dynamic TLS block.  Since we know that we generating an
 922       // executable, we can switch to Local-Exec.
 923       return tls::TLSOPT_TO_LE;
 924
 925     case elfcpp::R_X86_64_DTPOFF32:
 926     case elfcpp::R_X86_64_DTPOFF64:
 927       // Another Local-Dynamic reloc.
 928       return tls::TLSOPT_TO_LE;
 929
 930     case elfcpp::R_X86_64_GOTTPOFF:
 931       // These are Initial-Exec relocs which get the thread offset
 932       // from the GOT.  If we know that we are linking against the
 933       // local symbol, we can switch to Local-Exec, which links the
 934       // thread offset into the instruction.
 935       if (is_final)
 936         return tls::TLSOPT_TO_LE;
 937       return tls::TLSOPT_NONE;
 938
 939     case elfcpp::R_X86_64_TPOFF32:
 940       // When we already have Local-Exec, there is nothing further we
 941       // can do.
 942       return tls::TLSOPT_NONE;
 943
 944     default:
 945       gold_unreachable();
 946     }
 947 }
 948
 949 // Report an unsupported relocation against a local symbol.
 950
 951 void
 952 Target_x86_64::Scan::unsupported_reloc_local(Sized_relobj<64, false>* object,
 953                                              unsigned int r_type)
 954 {
 955   gold_error(_("%s: unsupported reloc %u against local symbol"),
 956              object->name().c_str(), r_type);
 957 }
 958
 959 // We are about to emit a dynamic relocation of type R_TYPE.  If the
 960 // dynamic linker does not support it, issue an error.  The GNU linker
 961 // only issues a non-PIC error for an allocated read-only section.
 962 // Here we know the section is allocated, but we don't know that it is
 963 // read-only.  But we check for all the relocation types which the
 964 // glibc dynamic linker supports, so it seems appropriate to issue an
 965 // error even if the section is not read-only.
 966
 967 void
 968 Target_x86_64::Scan::check_non_pic(Relobj* object, unsigned int r_type)
 969 {
 970   switch (r_type)
 971     {
 972       // These are the relocation types supported by glibc for x86_64.
 973     case elfcpp::R_X86_64_RELATIVE:
 974     case elfcpp::R_X86_64_GLOB_DAT:
 975     case elfcpp::R_X86_64_JUMP_SLOT:
 976     case elfcpp::R_X86_64_DTPMOD64:
 977     case elfcpp::R_X86_64_DTPOFF64:
 978     case elfcpp::R_X86_64_TPOFF64:
 979     case elfcpp::R_X86_64_64:
 980     case elfcpp::R_X86_64_32:
 981     case elfcpp::R_X86_64_PC32:
 982     case elfcpp::R_X86_64_COPY:
 983       return;
 984
 985     default:
 986       // This prevents us from issuing more than one error per reloc
 987       // section.  But we can still wind up issuing more than one
 988       // error per object file.
 989       if (this->issued_non_pic_error_)
 990         return;
 991       gold_assert(parameters->options().output_is_position_independent());
 992       object->error(_("requires unsupported dynamic reloc; "
 993                       "recompile with -fPIC"));
 994       this->issued_non_pic_error_ = true;
 995       return;
 996
 997     case elfcpp::R_X86_64_NONE:
 998       gold_unreachable();
 999     }
1000 }
1001
1002 // Scan a relocation for a local symbol.
1003
1004 inline void
1005 Target_x86_64::Scan::local(Symbol_table* symtab,
1006                            Layout* layout,
1007                            Target_x86_64* target,
1008                            Sized_relobj<64, false>* object,
1009                            unsigned int data_shndx,
1010                            Output_section* output_section,
1011                            const elfcpp::Rela<64, false>& reloc,
1012                            unsigned int r_type,
1013                            const elfcpp::Sym<64, false>& lsym)
1014 {
1015   switch (r_type)
1016     {
1017     case elfcpp::R_X86_64_NONE:
1018     case elfcpp::R_386_GNU_VTINHERIT:
1019     case elfcpp::R_386_GNU_VTENTRY:
1020       break;
1021
1022     case elfcpp::R_X86_64_64:
1023       // If building a shared library (or a position-independent
1024       // executable), we need to create a dynamic relocation for this
1025       // location.  The relocation applied at link time will apply the
1026       // link-time value, so we flag the location with an
1027       // R_X86_64_RELATIVE relocation so the dynamic loader can
1028       // relocate it easily.
1029       if (parameters->options().output_is_position_independent())
1030         {
1031           unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
1032           Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1033           rela_dyn->add_local_relative(object, r_sym,
1034                                        elfcpp::R_X86_64_RELATIVE,
1035                                        output_section, data_shndx,
1036                                        reloc.get_r_offset(),
1037                                        reloc.get_r_addend());
1038         }
1039       break;
1040
1041     case elfcpp::R_X86_64_32:
1042     case elfcpp::R_X86_64_32S:
1043     case elfcpp::R_X86_64_16:
1044     case elfcpp::R_X86_64_8:
1045       // If building a shared library (or a position-independent
1046       // executable), we need to create a dynamic relocation for this
1047       // location.  We can't use an R_X86_64_RELATIVE relocation
1048       // because that is always a 64-bit relocation.
1049       if (parameters->options().output_is_position_independent())
1050         {
1051           this->check_non_pic(object, r_type);
1052
1053           Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1054           unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
1055           if (lsym.get_st_type() != elfcpp::STT_SECTION)
1056             rela_dyn->add_local(object, r_sym, r_type, output_section,
1057                                 data_shndx, reloc.get_r_offset(),
1058                                 reloc.get_r_addend());
1059           else
1060             {
1061               gold_assert(lsym.get_st_value() == 0);
1062               unsigned int shndx = lsym.get_st_shndx();
1063               bool is_ordinary;
1064               shndx = object->adjust_sym_shndx(r_sym, shndx,
1065                                                &is_ordinary);
1066               if (!is_ordinary)
1067                 object->error(_("section symbol %u has bad shndx %u"),
1068                               r_sym, shndx);
1069               else
1070                 rela_dyn->add_local_section(object, shndx,
1071                                             r_type, output_section,
1072                                             data_shndx, reloc.get_r_offset(),
1073                                             reloc.get_r_addend());
1074             }
1075         }
1076       break;
1077
1078     case elfcpp::R_X86_64_PC64:
1079     case elfcpp::R_X86_64_PC32:
1080     case elfcpp::R_X86_64_PC16:
1081     case elfcpp::R_X86_64_PC8:
1082       break;
1083
1084     case elfcpp::R_X86_64_PLT32:
1085       // Since we know this is a local symbol, we can handle this as a
1086       // PC32 reloc.
1087       break;
1088
1089     case elfcpp::R_X86_64_GOTPC32:
1090     case elfcpp::R_X86_64_GOTOFF64:
1091     case elfcpp::R_X86_64_GOTPC64:
1092     case elfcpp::R_X86_64_PLTOFF64:
1093       // We need a GOT section.
1094       target->got_section(symtab, layout);
1095       // For PLTOFF64, we'd normally want a PLT section, but since we
1096       // know this is a local symbol, no PLT is needed.
1097       break;
1098
1099     case elfcpp::R_X86_64_GOT64:
1100     case elfcpp::R_X86_64_GOT32:
1101     case elfcpp::R_X86_64_GOTPCREL64:
1102     case elfcpp::R_X86_64_GOTPCREL:
1103     case elfcpp::R_X86_64_GOTPLT64:
1104       {
1105         // The symbol requires a GOT entry.
1106         Output_data_got<64, false>* got = target->got_section(symtab, layout);
1107         unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
1108         if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
1109           {
1110             // If we are generating a shared object, we need to add a
1111             // dynamic relocation for this symbol's GOT entry.
1112             if (parameters->options().output_is_position_independent())
1113               {
1114                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1115                 // R_X86_64_RELATIVE assumes a 64-bit relocation.
1116                 if (r_type != elfcpp::R_X86_64_GOT32)
1117                   rela_dyn->add_local_relative(
1118                       object, r_sym, elfcpp::R_X86_64_RELATIVE, got,
1119                       object->local_got_offset(r_sym, GOT_TYPE_STANDARD), 0);
1120                 else
1121                   {
1122                     this->check_non_pic(object, r_type);
1123
1124                     gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
1125                     rela_dyn->add_local(
1126                         object, r_sym, r_type, got,
1127                         object->local_got_offset(r_sym, GOT_TYPE_STANDARD), 0);
1128                   }
1129               }
1130           }
1131         // For GOTPLT64, we'd normally want a PLT section, but since
1132         // we know this is a local symbol, no PLT is needed.
1133       }
1134       break;
1135
1136     case elfcpp::R_X86_64_COPY:
1137     case elfcpp::R_X86_64_GLOB_DAT:
1138     case elfcpp::R_X86_64_JUMP_SLOT:
1139     case elfcpp::R_X86_64_RELATIVE:
1140       // These are outstanding tls relocs, which are unexpected when linking
1141     case elfcpp::R_X86_64_TPOFF64:
1142     case elfcpp::R_X86_64_DTPMOD64:
1143     case elfcpp::R_X86_64_TLSDESC:
1144       gold_error(_("%s: unexpected reloc %u in object file"),
1145                  object->name().c_str(), r_type);
1146       break;
1147
1148       // These are initial tls relocs, which are expected when linking
1149     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
1150     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
1151     case elfcpp::R_X86_64_TLSDESC_CALL:
1152     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
1153     case elfcpp::R_X86_64_DTPOFF32:
1154     case elfcpp::R_X86_64_DTPOFF64:
1155     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
1156     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
1157       {
1158         bool output_is_shared = parameters->options().shared();
1159         const tls::Tls_optimization optimized_type
1160             = Target_x86_64::optimize_tls_reloc(!output_is_shared, r_type);
1161         switch (r_type)
1162           {
1163           case elfcpp::R_X86_64_TLSGD:       // General-dynamic
1164             if (optimized_type == tls::TLSOPT_NONE)
1165               {
1166                 // Create a pair of GOT entries for the module index and
1167                 // dtv-relative offset.
1168                 Output_data_got<64, false>* got
1169                     = target->got_section(symtab, layout);
1170                 unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
1171                 unsigned int shndx = lsym.get_st_shndx();
1172                 bool is_ordinary;
1173                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1174                 if (!is_ordinary)
1175                   object->error(_("local symbol %u has bad shndx %u"),
1176                               r_sym, shndx);
1177                 else
1178                   got->add_local_pair_with_rela(object, r_sym,
1179                                                 shndx,
1180                                                 GOT_TYPE_TLS_PAIR,
1181                                                 target->rela_dyn_section(layout),
1182                                                 elfcpp::R_X86_64_DTPMOD64, 0);
1183               }
1184             else if (optimized_type != tls::TLSOPT_TO_LE)
1185               unsupported_reloc_local(object, r_type);
1186             break;
1187
1188           case elfcpp::R_X86_64_GOTPC32_TLSDESC:
1189             target->define_tls_base_symbol(symtab, layout);
1190             if (optimized_type == tls::TLSOPT_NONE)
1191               {
1192                 // Create reserved PLT and GOT entries for the resolver.
1193                 target->reserve_tlsdesc_entries(symtab, layout);
1194
1195                 // Generate a double GOT entry with an R_X86_64_TLSDESC reloc.
1196                 Output_data_got<64, false>* got
1197                     = target->got_section(symtab, layout);
1198                 unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
1199                 unsigned int shndx = lsym.get_st_shndx();
1200                 bool is_ordinary;
1201                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1202                 if (!is_ordinary)
1203                   object->error(_("local symbol %u has bad shndx %u"),
1204                               r_sym, shndx);
1205                 else
1206                   got->add_local_pair_with_rela(object, r_sym,
1207                                                 shndx,
1208                                                 GOT_TYPE_TLS_DESC,
1209                                                 target->rela_dyn_section(layout),
1210                                                 elfcpp::R_X86_64_TLSDESC, 0);
1211               }
1212             else if (optimized_type != tls::TLSOPT_TO_LE)
1213               unsupported_reloc_local(object, r_type);
1214             break;
1215
1216           case elfcpp::R_X86_64_TLSDESC_CALL:
1217             break;
1218
1219           case elfcpp::R_X86_64_TLSLD:       // Local-dynamic
1220             if (optimized_type == tls::TLSOPT_NONE)
1221               {
1222                 // Create a GOT entry for the module index.
1223                 target->got_mod_index_entry(symtab, layout, object);
1224               }
1225             else if (optimized_type != tls::TLSOPT_TO_LE)
1226               unsupported_reloc_local(object, r_type);
1227             break;
1228
1229           case elfcpp::R_X86_64_DTPOFF32:
1230           case elfcpp::R_X86_64_DTPOFF64:
1231             break;
1232
1233           case elfcpp::R_X86_64_GOTTPOFF:    // Initial-exec
1234             layout->set_has_static_tls();
1235             if (optimized_type == tls::TLSOPT_NONE)
1236               {
1237                 // Create a GOT entry for the tp-relative offset.
1238                 Output_data_got<64, false>* got
1239                     = target->got_section(symtab, layout);
1240                 unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
1241                 got->add_local_with_rela(object, r_sym, GOT_TYPE_TLS_OFFSET,
1242                                          target->rela_dyn_section(layout),
1243                                          elfcpp::R_X86_64_TPOFF64);
1244               }
1245             else if (optimized_type != tls::TLSOPT_TO_LE)
1246               unsupported_reloc_local(object, r_type);
1247             break;
1248
1249           case elfcpp::R_X86_64_TPOFF32:     // Local-exec
1250             layout->set_has_static_tls();
1251             if (output_is_shared)
1252               unsupported_reloc_local(object, r_type);
1253             break;
1254
1255           default:
1256             gold_unreachable();
1257           }
1258       }
1259       break;
1260
1261     case elfcpp::R_X86_64_SIZE32:
1262     case elfcpp::R_X86_64_SIZE64:
1263     default:
1264       gold_error(_("%s: unsupported reloc %u against local symbol"),
1265                  object->name().c_str(), r_type);
1266       break;
1267     }
1268 }
1269
1270
1271 // Report an unsupported relocation against a global symbol.
1272
1273 void
1274 Target_x86_64::Scan::unsupported_reloc_global(Sized_relobj<64, false>* object,
1275                                               unsigned int r_type,
1276                                               Symbol* gsym)
1277 {
1278   gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1279              object->name().c_str(), r_type, gsym->demangled_name().c_str());
1280 }
1281
1282 // Scan a relocation for a global symbol.
1283
1284 inline void
1285 Target_x86_64::Scan::global(Symbol_table* symtab,
1286                             Layout* layout,
1287                             Target_x86_64* target,
1288                             Sized_relobj<64, false>* object,
1289                             unsigned int data_shndx,
1290                             Output_section* output_section,
1291                             const elfcpp::Rela<64, false>& reloc,
1292                             unsigned int r_type,
1293                             Symbol* gsym)
1294 {
1295   switch (r_type)
1296     {
1297     case elfcpp::R_X86_64_NONE:
1298     case elfcpp::R_386_GNU_VTINHERIT:
1299     case elfcpp::R_386_GNU_VTENTRY:
1300       break;
1301
1302     case elfcpp::R_X86_64_64:
1303     case elfcpp::R_X86_64_32:
1304     case elfcpp::R_X86_64_32S:
1305     case elfcpp::R_X86_64_16:
1306     case elfcpp::R_X86_64_8:
1307       {
1308         // Make a PLT entry if necessary.
1309         if (gsym->needs_plt_entry())
1310           {
1311             target->make_plt_entry(symtab, layout, gsym);
1312             // Since this is not a PC-relative relocation, we may be
1313             // taking the address of a function. In that case we need to
1314             // set the entry in the dynamic symbol table to the address of
1315             // the PLT entry.
1316             if (gsym->is_from_dynobj() && !parameters->options().shared())
1317               gsym->set_needs_dynsym_value();
1318           }
1319         // Make a dynamic relocation if necessary.
1320         if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
1321           {
1322             if (gsym->may_need_copy_reloc())
1323               {
1324                 target->copy_reloc(symtab, layout, object,
1325                                    data_shndx, output_section, gsym, reloc);
1326               }
1327             else if (r_type == elfcpp::R_X86_64_64
1328                      && gsym->can_use_relative_reloc(false))
1329               {
1330                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1331                 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_RELATIVE,
1332                                               output_section, object,
1333                                               data_shndx, reloc.get_r_offset(),
1334                                               reloc.get_r_addend());
1335               }
1336             else
1337               {
1338                 this->check_non_pic(object, r_type);
1339                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1340                 rela_dyn->add_global(gsym, r_type, output_section, object,
1341                                      data_shndx, reloc.get_r_offset(),
1342                                      reloc.get_r_addend());
1343               }
1344           }
1345       }
1346       break;
1347
1348     case elfcpp::R_X86_64_PC64:
1349     case elfcpp::R_X86_64_PC32:
1350     case elfcpp::R_X86_64_PC16:
1351     case elfcpp::R_X86_64_PC8:
1352       {
1353         // Make a PLT entry if necessary.
1354         if (gsym->needs_plt_entry())
1355           target->make_plt_entry(symtab, layout, gsym);
1356         // Make a dynamic relocation if necessary.
1357         int flags = Symbol::NON_PIC_REF;
1358         if (gsym->is_func())
1359           flags |= Symbol::FUNCTION_CALL;
1360         if (gsym->needs_dynamic_reloc(flags))
1361           {
1362             if (gsym->may_need_copy_reloc())
1363               {
1364                 target->copy_reloc(symtab, layout, object,
1365                                    data_shndx, output_section, gsym, reloc);
1366               }
1367             else
1368               {
1369                 this->check_non_pic(object, r_type);
1370                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1371                 rela_dyn->add_global(gsym, r_type, output_section, object,
1372                                      data_shndx, reloc.get_r_offset(),
1373                                      reloc.get_r_addend());
1374               }
1375           }
1376       }
1377       break;
1378
1379     case elfcpp::R_X86_64_GOT64:
1380     case elfcpp::R_X86_64_GOT32:
1381     case elfcpp::R_X86_64_GOTPCREL64:
1382     case elfcpp::R_X86_64_GOTPCREL:
1383     case elfcpp::R_X86_64_GOTPLT64:
1384       {
1385         // The symbol requires a GOT entry.
1386         Output_data_got<64, false>* got = target->got_section(symtab, layout);
1387         if (gsym->final_value_is_known())
1388           got->add_global(gsym, GOT_TYPE_STANDARD);
1389         else
1390           {
1391             // If this symbol is not fully resolved, we need to add a
1392             // dynamic relocation for it.
1393             Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1394             if (gsym->is_from_dynobj()
1395                 || gsym->is_undefined()
1396                 || gsym->is_preemptible())
1397               got->add_global_with_rela(gsym, GOT_TYPE_STANDARD, rela_dyn,
1398                                         elfcpp::R_X86_64_GLOB_DAT);
1399             else
1400               {
1401                 if (got->add_global(gsym, GOT_TYPE_STANDARD))
1402                   rela_dyn->add_global_relative(
1403                       gsym, elfcpp::R_X86_64_RELATIVE, got,
1404                       gsym->got_offset(GOT_TYPE_STANDARD), 0);
1405               }
1406           }
1407         // For GOTPLT64, we also need a PLT entry (but only if the
1408         // symbol is not fully resolved).
1409         if (r_type == elfcpp::R_X86_64_GOTPLT64
1410             && !gsym->final_value_is_known())
1411           target->make_plt_entry(symtab, layout, gsym);
1412       }
1413       break;
1414
1415     case elfcpp::R_X86_64_PLT32:
1416       // If the symbol is fully resolved, this is just a PC32 reloc.
1417       // Otherwise we need a PLT entry.
1418       if (gsym->final_value_is_known())
1419         break;
1420       // If building a shared library, we can also skip the PLT entry
1421       // if the symbol is defined in the output file and is protected
1422       // or hidden.
1423       if (gsym->is_defined()
1424           && !gsym->is_from_dynobj()
1425           && !gsym->is_preemptible())
1426         break;
1427       target->make_plt_entry(symtab, layout, gsym);
1428       break;
1429
1430     case elfcpp::R_X86_64_GOTPC32:
1431     case elfcpp::R_X86_64_GOTOFF64:
1432     case elfcpp::R_X86_64_GOTPC64:
1433     case elfcpp::R_X86_64_PLTOFF64:
1434       // We need a GOT section.
1435       target->got_section(symtab, layout);
1436       // For PLTOFF64, we also need a PLT entry (but only if the
1437       // symbol is not fully resolved).
1438       if (r_type == elfcpp::R_X86_64_PLTOFF64
1439           && !gsym->final_value_is_known())
1440         target->make_plt_entry(symtab, layout, gsym);
1441       break;
1442
1443     case elfcpp::R_X86_64_COPY:
1444     case elfcpp::R_X86_64_GLOB_DAT:
1445     case elfcpp::R_X86_64_JUMP_SLOT:
1446     case elfcpp::R_X86_64_RELATIVE:
1447       // These are outstanding tls relocs, which are unexpected when linking
1448     case elfcpp::R_X86_64_TPOFF64:
1449     case elfcpp::R_X86_64_DTPMOD64:
1450     case elfcpp::R_X86_64_TLSDESC:
1451       gold_error(_("%s: unexpected reloc %u in object file"),
1452                  object->name().c_str(), r_type);
1453       break;
1454
1455       // These are initial tls relocs, which are expected for global()
1456     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
1457     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
1458     case elfcpp::R_X86_64_TLSDESC_CALL:
1459     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
1460     case elfcpp::R_X86_64_DTPOFF32:
1461     case elfcpp::R_X86_64_DTPOFF64:
1462     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
1463     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
1464       {
1465         const bool is_final = gsym->final_value_is_known();
1466         const tls::Tls_optimization optimized_type
1467             = Target_x86_64::optimize_tls_reloc(is_final, r_type);
1468         switch (r_type)
1469           {
1470           case elfcpp::R_X86_64_TLSGD:       // General-dynamic
1471             if (optimized_type == tls::TLSOPT_NONE)
1472               {
1473                 // Create a pair of GOT entries for the module index and
1474                 // dtv-relative offset.
1475                 Output_data_got<64, false>* got
1476                     = target->got_section(symtab, layout);
1477                 got->add_global_pair_with_rela(gsym, GOT_TYPE_TLS_PAIR,
1478                                                target->rela_dyn_section(layout),
1479                                                elfcpp::R_X86_64_DTPMOD64,
1480                                                elfcpp::R_X86_64_DTPOFF64);
1481               }
1482             else if (optimized_type == tls::TLSOPT_TO_IE)
1483               {
1484                 // Create a GOT entry for the tp-relative offset.
1485                 Output_data_got<64, false>* got
1486                     = target->got_section(symtab, layout);
1487                 got->add_global_with_rela(gsym, GOT_TYPE_TLS_OFFSET,
1488                                           target->rela_dyn_section(layout),
1489                                           elfcpp::R_X86_64_TPOFF64);
1490               }
1491             else if (optimized_type != tls::TLSOPT_TO_LE)
1492               unsupported_reloc_global(object, r_type, gsym);
1493             break;
1494
1495           case elfcpp::R_X86_64_GOTPC32_TLSDESC:
1496             target->define_tls_base_symbol(symtab, layout);
1497             if (optimized_type == tls::TLSOPT_NONE)
1498               {
1499                 // Create reserved PLT and GOT entries for the resolver.
1500                 target->reserve_tlsdesc_entries(symtab, layout);
1501
1502                 // Create a double GOT entry with an R_X86_64_TLSDESC reloc.
1503                 Output_data_got<64, false>* got
1504                     = target->got_section(symtab, layout);
1505                 got->add_global_pair_with_rela(gsym, GOT_TYPE_TLS_DESC,
1506                                                target->rela_dyn_section(layout),
1507                                                elfcpp::R_X86_64_TLSDESC, 0);
1508               }
1509             else if (optimized_type == tls::TLSOPT_TO_IE)
1510               {
1511                 // Create a GOT entry for the tp-relative offset.
1512                 Output_data_got<64, false>* got
1513                     = target->got_section(symtab, layout);
1514                 got->add_global_with_rela(gsym, GOT_TYPE_TLS_OFFSET,
1515                                           target->rela_dyn_section(layout),
1516                                           elfcpp::R_X86_64_TPOFF64);
1517               }
1518             else if (optimized_type != tls::TLSOPT_TO_LE)
1519               unsupported_reloc_global(object, r_type, gsym);
1520             break;
1521
1522           case elfcpp::R_X86_64_TLSDESC_CALL:
1523             break;
1524
1525           case elfcpp::R_X86_64_TLSLD:       // Local-dynamic
1526             if (optimized_type == tls::TLSOPT_NONE)
1527               {
1528                 // Create a GOT entry for the module index.
1529                 target->got_mod_index_entry(symtab, layout, object);
1530               }
1531             else if (optimized_type != tls::TLSOPT_TO_LE)
1532               unsupported_reloc_global(object, r_type, gsym);
1533             break;
1534
1535           case elfcpp::R_X86_64_DTPOFF32:
1536           case elfcpp::R_X86_64_DTPOFF64:
1537             break;
1538
1539           case elfcpp::R_X86_64_GOTTPOFF:    // Initial-exec
1540             layout->set_has_static_tls();
1541             if (optimized_type == tls::TLSOPT_NONE)
1542               {
1543                 // Create a GOT entry for the tp-relative offset.
1544                 Output_data_got<64, false>* got
1545                     = target->got_section(symtab, layout);
1546                 got->add_global_with_rela(gsym, GOT_TYPE_TLS_OFFSET,
1547                                           target->rela_dyn_section(layout),
1548                                           elfcpp::R_X86_64_TPOFF64);
1549               }
1550             else if (optimized_type != tls::TLSOPT_TO_LE)
1551               unsupported_reloc_global(object, r_type, gsym);
1552             break;
1553
1554           case elfcpp::R_X86_64_TPOFF32:     // Local-exec
1555             layout->set_has_static_tls();
1556             if (parameters->options().shared())
1557               unsupported_reloc_local(object, r_type);
1558             break;
1559
1560           default:
1561             gold_unreachable();
1562           }
1563       }
1564       break;
1565
1566     case elfcpp::R_X86_64_SIZE32:
1567     case elfcpp::R_X86_64_SIZE64:
1568     default:
1569       gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1570                  object->name().c_str(), r_type,
1571                  gsym->demangled_name().c_str());
1572       break;
1573     }
1574 }
1575
1576 void
1577 Target_x86_64::gc_process_relocs(Symbol_table* symtab,
1578                                  Layout* layout,
1579                                  Sized_relobj<64, false>* object,
1580                                  unsigned int data_shndx,
1581                                  unsigned int sh_type,
1582                                  const unsigned char* prelocs,
1583                                  size_t reloc_count,
1584                                  Output_section* output_section,
1585                                  bool needs_special_offset_handling,
1586                                  size_t local_symbol_count,
1587                                  const unsigned char* plocal_symbols)
1588 {
1589
1590   if (sh_type == elfcpp::SHT_REL)
1591     {
1592       return;
1593     }
1594
1595    gold::gc_process_relocs<64, false, Target_x86_64, elfcpp::SHT_RELA,
1596                            Target_x86_64::Scan>(
1597     symtab,
1598     layout,
1599     this,
1600     object,
1601     data_shndx,
1602     prelocs,
1603     reloc_count,
1604     output_section,
1605     needs_special_offset_handling,
1606     local_symbol_count,
1607     plocal_symbols);
1608
1609 }
1610 // Scan relocations for a section.
1611
1612 void
1613 Target_x86_64::scan_relocs(Symbol_table* symtab,
1614                            Layout* layout,
1615                            Sized_relobj<64, false>* object,
1616                            unsigned int data_shndx,
1617                            unsigned int sh_type,
1618                            const unsigned char* prelocs,
1619                            size_t reloc_count,
1620                            Output_section* output_section,
1621                            bool needs_special_offset_handling,
1622                            size_t local_symbol_count,
1623                            const unsigned char* plocal_symbols)
1624 {
1625   if (sh_type == elfcpp::SHT_REL)
1626     {
1627       gold_error(_("%s: unsupported REL reloc section"),
1628                  object->name().c_str());
1629       return;
1630     }
1631
1632   gold::scan_relocs<64, false, Target_x86_64, elfcpp::SHT_RELA,
1633       Target_x86_64::Scan>(
1634     symtab,
1635     layout,
1636     this,
1637     object,
1638     data_shndx,
1639     prelocs,
1640     reloc_count,
1641     output_section,
1642     needs_special_offset_handling,
1643     local_symbol_count,
1644     plocal_symbols);
1645 }
1646
1647 // Finalize the sections.
1648
1649 void
1650 Target_x86_64::do_finalize_sections(
1651     Layout* layout,
1652     const Input_objects*,
1653     Symbol_table*)
1654 {
1655   // Fill in some more dynamic tags.
1656   Output_data_dynamic* const odyn = layout->dynamic_data();
1657   if (odyn != NULL)
1658     {
1659       if (this->got_plt_ != NULL
1660           && this->got_plt_->output_section() != NULL)
1661         odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_);
1662
1663       if (this->plt_ != NULL
1664           && this->plt_->output_section() != NULL)
1665         {
1666           const Output_data* od = this->plt_->rel_plt();
1667           odyn->add_section_size(elfcpp::DT_PLTRELSZ, od);
1668           odyn->add_section_address(elfcpp::DT_JMPREL, od);
1669           odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_RELA);
1670           if (this->plt_->has_tlsdesc_entry())
1671             {
1672               unsigned int plt_offset = this->plt_->get_tlsdesc_plt_offset();
1673               unsigned int got_offset = this->plt_->get_tlsdesc_got_offset();
1674               this->got_->finalize_data_size();
1675               odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_PLT,
1676                                             this->plt_, plt_offset);
1677               odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_GOT,
1678                                             this->got_, got_offset);
1679             }
1680         }
1681
1682       if (this->rela_dyn_ != NULL
1683           && this->rela_dyn_->output_section() != NULL)
1684         {
1685           const Output_data* od = this->rela_dyn_;
1686           odyn->add_section_address(elfcpp::DT_RELA, od);
1687           odyn->add_section_size(elfcpp::DT_RELASZ, od);
1688           odyn->add_constant(elfcpp::DT_RELAENT,
1689                              elfcpp::Elf_sizes<64>::rela_size);
1690         }
1691
1692       if (!parameters->options().shared())
1693         {
1694           // The value of the DT_DEBUG tag is filled in by the dynamic
1695           // linker at run time, and used by the debugger.
1696           odyn->add_constant(elfcpp::DT_DEBUG, 0);
1697         }
1698     }
1699
1700   // Emit any relocs we saved in an attempt to avoid generating COPY
1701   // relocs.
1702   if (this->copy_relocs_.any_saved_relocs())
1703     this->copy_relocs_.emit(this->rela_dyn_section(layout));
1704 }
1705
1706 // Perform a relocation.
1707
1708 inline bool
1709 Target_x86_64::Relocate::relocate(const Relocate_info<64, false>* relinfo,
1710                                   Target_x86_64* target,
1711                                   Output_section*,
1712                                   size_t relnum,
1713                                   const elfcpp::Rela<64, false>& rela,
1714                                   unsigned int r_type,
1715                                   const Sized_symbol<64>* gsym,
1716                                   const Symbol_value<64>* psymval,
1717                                   unsigned char* view,
1718                                   elfcpp::Elf_types<64>::Elf_Addr address,
1719                                   section_size_type view_size)
1720 {
1721   if (this->skip_call_tls_get_addr_)
1722     {
1723       if ((r_type != elfcpp::R_X86_64_PLT32
1724            && r_type != elfcpp::R_X86_64_PC32)
1725           || gsym == NULL
1726           || strcmp(gsym->name(), "__tls_get_addr") != 0)
1727         {
1728           gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
1729                                  _("missing expected TLS relocation"));
1730         }
1731       else
1732         {
1733           this->skip_call_tls_get_addr_ = false;
1734           return false;
1735         }
1736     }
1737
1738   // Pick the value to use for symbols defined in shared objects.
1739   Symbol_value<64> symval;
1740   if (gsym != NULL
1741       && gsym->use_plt_offset(r_type == elfcpp::R_X86_64_PC64
1742                               || r_type == elfcpp::R_X86_64_PC32
1743                               || r_type == elfcpp::R_X86_64_PC16
1744                               || r_type == elfcpp::R_X86_64_PC8))
1745     {
1746       symval.set_output_value(target->plt_section()->address()
1747                               + gsym->plt_offset());
1748       psymval = &symval;
1749     }
1750
1751   const Sized_relobj<64, false>* object = relinfo->object;
1752   const elfcpp::Elf_Xword addend = rela.get_r_addend();
1753
1754   // Get the GOT offset if needed.
1755   // The GOT pointer points to the end of the GOT section.
1756   // We need to subtract the size of the GOT section to get
1757   // the actual offset to use in the relocation.
1758   bool have_got_offset = false;
1759   unsigned int got_offset = 0;
1760   switch (r_type)
1761     {
1762     case elfcpp::R_X86_64_GOT32:
1763     case elfcpp::R_X86_64_GOT64:
1764     case elfcpp::R_X86_64_GOTPLT64:
1765     case elfcpp::R_X86_64_GOTPCREL:
1766     case elfcpp::R_X86_64_GOTPCREL64:
1767       if (gsym != NULL)
1768         {
1769           gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
1770           got_offset = gsym->got_offset(GOT_TYPE_STANDARD) - target->got_size();
1771         }
1772       else
1773         {
1774           unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
1775           gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
1776           got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
1777                         - target->got_size());
1778         }
1779       have_got_offset = true;
1780       break;
1781
1782     default:
1783       break;
1784     }
1785
1786   switch (r_type)
1787     {
1788     case elfcpp::R_X86_64_NONE:
1789     case elfcpp::R_386_GNU_VTINHERIT:
1790     case elfcpp::R_386_GNU_VTENTRY:
1791       break;
1792
1793     case elfcpp::R_X86_64_64:
1794       Relocate_functions<64, false>::rela64(view, object, psymval, addend);
1795       break;
1796
1797     case elfcpp::R_X86_64_PC64:
1798       Relocate_functions<64, false>::pcrela64(view, object, psymval, addend,
1799                                               address);
1800       break;
1801
1802     case elfcpp::R_X86_64_32:
1803       // FIXME: we need to verify that value + addend fits into 32 bits:
1804       //    uint64_t x = value + addend;
1805       //    x == static_cast<uint64_t>(static_cast<uint32_t>(x))
1806       // Likewise for other <=32-bit relocations (but see R_X86_64_32S).
1807       Relocate_functions<64, false>::rela32(view, object, psymval, addend);
1808       break;
1809
1810     case elfcpp::R_X86_64_32S:
1811       // FIXME: we need to verify that value + addend fits into 32 bits:
1812       //    int64_t x = value + addend;   // note this quantity is signed!
1813       //    x == static_cast<int64_t>(static_cast<int32_t>(x))
1814       Relocate_functions<64, false>::rela32(view, object, psymval, addend);
1815       break;
1816
1817     case elfcpp::R_X86_64_PC32:
1818       Relocate_functions<64, false>::pcrela32(view, object, psymval, addend,
1819                                               address);
1820       break;
1821
1822     case elfcpp::R_X86_64_16:
1823       Relocate_functions<64, false>::rela16(view, object, psymval, addend);
1824       break;
1825
1826     case elfcpp::R_X86_64_PC16:
1827       Relocate_functions<64, false>::pcrela16(view, object, psymval, addend,
1828                                               address);
1829       break;
1830
1831     case elfcpp::R_X86_64_8:
1832       Relocate_functions<64, false>::rela8(view, object, psymval, addend);
1833       break;
1834
1835     case elfcpp::R_X86_64_PC8:
1836       Relocate_functions<64, false>::pcrela8(view, object, psymval, addend,
1837                                              address);
1838       break;
1839
1840     case elfcpp::R_X86_64_PLT32:
1841       gold_assert(gsym == NULL
1842                   || gsym->has_plt_offset()
1843                   || gsym->final_value_is_known()
1844                   || (gsym->is_defined()
1845                       && !gsym->is_from_dynobj()
1846                       && !gsym->is_preemptible()));
1847       // Note: while this code looks the same as for R_X86_64_PC32, it
1848       // behaves differently because psymval was set to point to
1849       // the PLT entry, rather than the symbol, in Scan::global().
1850       Relocate_functions<64, false>::pcrela32(view, object, psymval, addend,
1851                                               address);
1852       break;
1853
1854     case elfcpp::R_X86_64_PLTOFF64:
1855       {
1856         gold_assert(gsym);
1857         gold_assert(gsym->has_plt_offset()
1858                     || gsym->final_value_is_known());
1859         elfcpp::Elf_types<64>::Elf_Addr got_address;
1860         got_address = target->got_section(NULL, NULL)->address();
1861         Relocate_functions<64, false>::rela64(view, object, psymval,
1862                                               addend - got_address);
1863       }
1864
1865     case elfcpp::R_X86_64_GOT32:
1866       gold_assert(have_got_offset);
1867       Relocate_functions<64, false>::rela32(view, got_offset, addend);
1868       break;
1869
1870     case elfcpp::R_X86_64_GOTPC32:
1871       {
1872         gold_assert(gsym);
1873         elfcpp::Elf_types<64>::Elf_Addr value;
1874         value = target->got_plt_section()->address();
1875         Relocate_functions<64, false>::pcrela32(view, value, addend, address);
1876       }
1877       break;
1878
1879     case elfcpp::R_X86_64_GOT64:
1880       // The ABI doc says "Like GOT64, but indicates a PLT entry is needed."
1881       // Since we always add a PLT entry, this is equivalent.
1882     case elfcpp::R_X86_64_GOTPLT64:
1883       gold_assert(have_got_offset);
1884       Relocate_functions<64, false>::rela64(view, got_offset, addend);
1885       break;
1886
1887     case elfcpp::R_X86_64_GOTPC64:
1888       {
1889         gold_assert(gsym);
1890         elfcpp::Elf_types<64>::Elf_Addr value;
1891         value = target->got_plt_section()->address();
1892         Relocate_functions<64, false>::pcrela64(view, value, addend, address);
1893       }
1894       break;
1895
1896     case elfcpp::R_X86_64_GOTOFF64:
1897       {
1898         elfcpp::Elf_types<64>::Elf_Addr value;
1899         value = (psymval->value(object, 0)
1900                  - target->got_plt_section()->address());
1901         Relocate_functions<64, false>::rela64(view, value, addend);
1902       }
1903       break;
1904
1905     case elfcpp::R_X86_64_GOTPCREL:
1906       {
1907         gold_assert(have_got_offset);
1908         elfcpp::Elf_types<64>::Elf_Addr value;
1909         value = target->got_plt_section()->address() + got_offset;
1910         Relocate_functions<64, false>::pcrela32(view, value, addend, address);
1911       }
1912       break;
1913
1914     case elfcpp::R_X86_64_GOTPCREL64:
1915       {
1916         gold_assert(have_got_offset);
1917         elfcpp::Elf_types<64>::Elf_Addr value;
1918         value = target->got_plt_section()->address() + got_offset;
1919         Relocate_functions<64, false>::pcrela64(view, value, addend, address);
1920       }
1921       break;
1922
1923     case elfcpp::R_X86_64_COPY:
1924     case elfcpp::R_X86_64_GLOB_DAT:
1925     case elfcpp::R_X86_64_JUMP_SLOT:
1926     case elfcpp::R_X86_64_RELATIVE:
1927       // These are outstanding tls relocs, which are unexpected when linking
1928     case elfcpp::R_X86_64_TPOFF64:
1929     case elfcpp::R_X86_64_DTPMOD64:
1930     case elfcpp::R_X86_64_TLSDESC:
1931       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
1932                              _("unexpected reloc %u in object file"),
1933                              r_type);
1934       break;
1935
1936       // These are initial tls relocs, which are expected when linking
1937     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
1938     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
1939     case elfcpp::R_X86_64_TLSDESC_CALL:
1940     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
1941     case elfcpp::R_X86_64_DTPOFF32:
1942     case elfcpp::R_X86_64_DTPOFF64:
1943     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
1944     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
1945       this->relocate_tls(relinfo, target, relnum, rela, r_type, gsym, psymval,
1946                          view, address, view_size);
1947       break;
1948
1949     case elfcpp::R_X86_64_SIZE32:
1950     case elfcpp::R_X86_64_SIZE64:
1951     default:
1952       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
1953                              _("unsupported reloc %u"),
1954                              r_type);
1955       break;
1956     }
1957
1958   return true;
1959 }
1960
1961 // Perform a TLS relocation.
1962
1963 inline void
1964 Target_x86_64::Relocate::relocate_tls(const Relocate_info<64, false>* relinfo,
1965                                       Target_x86_64* target,
1966                                       size_t relnum,
1967                                       const elfcpp::Rela<64, false>& rela,
1968                                       unsigned int r_type,
1969                                       const Sized_symbol<64>* gsym,
1970                                       const Symbol_value<64>* psymval,
1971                                       unsigned char* view,
1972                                       elfcpp::Elf_types<64>::Elf_Addr address,
1973                                       section_size_type view_size)
1974 {
1975   Output_segment* tls_segment = relinfo->layout->tls_segment();
1976
1977   const Sized_relobj<64, false>* object = relinfo->object;
1978   const elfcpp::Elf_Xword addend = rela.get_r_addend();
1979
1980   elfcpp::Elf_types<64>::Elf_Addr value = psymval->value(relinfo->object, 0);
1981
1982   const bool is_final = (gsym == NULL
1983                          ? !parameters->options().output_is_position_independent()
1984                          : gsym->final_value_is_known());
1985   const tls::Tls_optimization optimized_type
1986       = Target_x86_64::optimize_tls_reloc(is_final, r_type);
1987   switch (r_type)
1988     {
1989     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
1990       this->saw_tls_block_reloc_ = true;
1991       if (optimized_type == tls::TLSOPT_TO_LE)
1992         {
1993           gold_assert(tls_segment != NULL);
1994           this->tls_gd_to_le(relinfo, relnum, tls_segment,
1995                              rela, r_type, value, view,
1996                              view_size);
1997           break;
1998         }
1999       else
2000         {
2001           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
2002                                    ? GOT_TYPE_TLS_OFFSET
2003                                    : GOT_TYPE_TLS_PAIR);
2004           unsigned int got_offset;
2005           if (gsym != NULL)
2006             {
2007               gold_assert(gsym->has_got_offset(got_type));
2008               got_offset = gsym->got_offset(got_type) - target->got_size();
2009             }
2010           else
2011             {
2012               unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
2013               gold_assert(object->local_has_got_offset(r_sym, got_type));
2014               got_offset = (object->local_got_offset(r_sym, got_type)
2015                             - target->got_size());
2016             }
2017           if (optimized_type == tls::TLSOPT_TO_IE)
2018             {
2019               gold_assert(tls_segment != NULL);
2020               value = target->got_plt_section()->address() + got_offset;
2021               this->tls_gd_to_ie(relinfo, relnum, tls_segment, rela, r_type,
2022                                  value, view, address, view_size);
2023               break;
2024             }
2025           else if (optimized_type == tls::TLSOPT_NONE)
2026             {
2027               // Relocate the field with the offset of the pair of GOT
2028               // entries.
2029               value = target->got_plt_section()->address() + got_offset;
2030               Relocate_functions<64, false>::pcrela32(view, value, addend,
2031                                                       address);
2032               break;
2033             }
2034         }
2035       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
2036                              _("unsupported reloc %u"), r_type);
2037       break;
2038
2039     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
2040     case elfcpp::R_X86_64_TLSDESC_CALL:
2041       this->saw_tls_block_reloc_ = true;
2042       if (optimized_type == tls::TLSOPT_TO_LE)
2043         {
2044           gold_assert(tls_segment != NULL);
2045           this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
2046                                   rela, r_type, value, view,
2047                                   view_size);
2048           break;
2049         }
2050       else
2051         {
2052           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
2053                                    ? GOT_TYPE_TLS_OFFSET
2054                                    : GOT_TYPE_TLS_DESC);
2055           unsigned int got_offset;
2056           if (gsym != NULL)
2057             {
2058               gold_assert(gsym->has_got_offset(got_type));
2059               got_offset = gsym->got_offset(got_type) - target->got_size();
2060             }
2061           else
2062             {
2063               unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
2064               gold_assert(object->local_has_got_offset(r_sym, got_type));
2065               got_offset = (object->local_got_offset(r_sym, got_type)
2066                             - target->got_size());
2067             }
2068           if (optimized_type == tls::TLSOPT_TO_IE)
2069             {
2070               gold_assert(tls_segment != NULL);
2071               value = target->got_plt_section()->address() + got_offset;
2072               this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment,
2073                                       rela, r_type, value, view, address,
2074                                       view_size);
2075               break;
2076             }
2077           else if (optimized_type == tls::TLSOPT_NONE)
2078             {
2079               if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
2080                 {
2081                   // Relocate the field with the offset of the pair of GOT
2082                   // entries.
2083                   value = target->got_plt_section()->address() + got_offset;
2084                   Relocate_functions<64, false>::pcrela32(view, value, addend,
2085                                                           address);
2086                 }
2087               break;
2088             }
2089         }
2090       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
2091                              _("unsupported reloc %u"), r_type);
2092       break;
2093
2094     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
2095       this->saw_tls_block_reloc_ = true;
2096       if (optimized_type == tls::TLSOPT_TO_LE)
2097         {
2098           gold_assert(tls_segment != NULL);
2099           this->tls_ld_to_le(relinfo, relnum, tls_segment, rela, r_type,
2100                              value, view, view_size);
2101           break;
2102         }
2103       else if (optimized_type == tls::TLSOPT_NONE)
2104         {
2105           // Relocate the field with the offset of the GOT entry for
2106           // the module index.
2107           unsigned int got_offset;
2108           got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
2109                         - target->got_size());
2110           value = target->got_plt_section()->address() + got_offset;
2111           Relocate_functions<64, false>::pcrela32(view, value, addend,
2112                                                   address);
2113           break;
2114         }
2115       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
2116                              _("unsupported reloc %u"), r_type);
2117       break;
2118
2119     case elfcpp::R_X86_64_DTPOFF32:
2120       if (optimized_type == tls::TLSOPT_TO_LE)
2121         {
2122           // This relocation type is used in debugging information.
2123           // In that case we need to not optimize the value.  If we
2124           // haven't seen a TLSLD reloc, then we assume we should not
2125           // optimize this reloc.
2126           if (this->saw_tls_block_reloc_)
2127             {
2128               gold_assert(tls_segment != NULL);
2129               value -= tls_segment->memsz();
2130             }
2131         }
2132       Relocate_functions<64, false>::rela32(view, value, addend);
2133       break;
2134
2135     case elfcpp::R_X86_64_DTPOFF64:
2136       if (optimized_type == tls::TLSOPT_TO_LE)
2137         {
2138           // See R_X86_64_DTPOFF32, just above, for why we test this.
2139           if (this->saw_tls_block_reloc_)
2140             {
2141               gold_assert(tls_segment != NULL);
2142               value -= tls_segment->memsz();
2143             }
2144         }
2145       Relocate_functions<64, false>::rela64(view, value, addend);
2146       break;
2147
2148     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
2149       if (optimized_type == tls::TLSOPT_TO_LE)
2150         {
2151           gold_assert(tls_segment != NULL);
2152           Target_x86_64::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
2153                                                 rela, r_type, value, view,
2154                                                 view_size);
2155           break;
2156         }
2157       else if (optimized_type == tls::TLSOPT_NONE)
2158         {
2159           // Relocate the field with the offset of the GOT entry for
2160           // the tp-relative offset of the symbol.
2161           unsigned int got_offset;
2162           if (gsym != NULL)
2163             {
2164               gold_assert(gsym->has_got_offset(GOT_TYPE_TLS_OFFSET));
2165               got_offset = (gsym->got_offset(GOT_TYPE_TLS_OFFSET)
2166                             - target->got_size());
2167             }
2168           else
2169             {
2170               unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
2171               gold_assert(object->local_has_got_offset(r_sym,
2172                                                        GOT_TYPE_TLS_OFFSET));
2173               got_offset = (object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET)
2174                             - target->got_size());
2175             }
2176           value = target->got_plt_section()->address() + got_offset;
2177           Relocate_functions<64, false>::pcrela32(view, value, addend, address);
2178           break;
2179         }
2180       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
2181                              _("unsupported reloc type %u"),
2182                              r_type);
2183       break;
2184
2185     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
2186       value -= tls_segment->memsz();
2187       Relocate_functions<64, false>::rela32(view, value, addend);
2188       break;
2189     }
2190 }
2191
2192 // Do a relocation in which we convert a TLS General-Dynamic to an
2193 // Initial-Exec.
2194
2195 inline void
2196 Target_x86_64::Relocate::tls_gd_to_ie(const Relocate_info<64, false>* relinfo,
2197                                       size_t relnum,
2198                                       Output_segment*,
2199                                       const elfcpp::Rela<64, false>& rela,
2200                                       unsigned int,
2201                                       elfcpp::Elf_types<64>::Elf_Addr value,
2202                                       unsigned char* view,
2203                                       elfcpp::Elf_types<64>::Elf_Addr address,
2204                                       section_size_type view_size)
2205 {
2206   // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
2207   // .word 0x6666; rex64; call __tls_get_addr
2208   // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
2209
2210   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -4);
2211   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
2212
2213   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2214                  (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
2215   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2216                  (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0));
2217
2218   memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0", 16);
2219
2220   const elfcpp::Elf_Xword addend = rela.get_r_addend();
2221   Relocate_functions<64, false>::pcrela32(view + 8, value, addend - 8, address);
2222
2223   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2224   // We can skip it.
2225   this->skip_call_tls_get_addr_ = true;
2226 }
2227
2228 // Do a relocation in which we convert a TLS General-Dynamic to a
2229 // Local-Exec.
2230
2231 inline void
2232 Target_x86_64::Relocate::tls_gd_to_le(const Relocate_info<64, false>* relinfo,
2233                                       size_t relnum,
2234                                       Output_segment* tls_segment,
2235                                       const elfcpp::Rela<64, false>& rela,
2236                                       unsigned int,
2237                                       elfcpp::Elf_types<64>::Elf_Addr value,
2238                                       unsigned char* view,
2239                                       section_size_type view_size)
2240 {
2241   // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
2242   // .word 0x6666; rex64; call __tls_get_addr
2243   // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
2244
2245   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -4);
2246   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
2247
2248   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2249                  (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
2250   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2251                  (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0));
2252
2253   memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0", 16);
2254
2255   value -= tls_segment->memsz();
2256   Relocate_functions<64, false>::rela32(view + 8, value, 0);
2257
2258   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2259   // We can skip it.
2260   this->skip_call_tls_get_addr_ = true;
2261 }
2262
2263 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
2264
2265 inline void
2266 Target_x86_64::Relocate::tls_desc_gd_to_ie(
2267     const Relocate_info<64, false>* relinfo,
2268     size_t relnum,
2269     Output_segment*,
2270     const elfcpp::Rela<64, false>& rela,
2271     unsigned int r_type,
2272     elfcpp::Elf_types<64>::Elf_Addr value,
2273     unsigned char* view,
2274     elfcpp::Elf_types<64>::Elf_Addr address,
2275     section_size_type view_size)
2276 {
2277   if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
2278     {
2279       // leaq foo@tlsdesc(%rip), %rax
2280       // ==> movq foo@gottpoff(%rip), %rax
2281       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
2282       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
2283       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2284                      view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05);
2285       view[-2] = 0x8b;
2286       const elfcpp::Elf_Xword addend = rela.get_r_addend();
2287       Relocate_functions<64, false>::pcrela32(view, value, addend, address);
2288     }
2289   else
2290     {
2291       // call *foo@tlscall(%rax)
2292       // ==> nop; nop
2293       gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
2294       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
2295       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2296                      view[0] == 0xff && view[1] == 0x10);
2297       view[0] = 0x66;
2298       view[1] = 0x90;
2299     }
2300 }
2301
2302 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
2303
2304 inline void
2305 Target_x86_64::Relocate::tls_desc_gd_to_le(
2306     const Relocate_info<64, false>* relinfo,
2307     size_t relnum,
2308     Output_segment* tls_segment,
2309     const elfcpp::Rela<64, false>& rela,
2310     unsigned int r_type,
2311     elfcpp::Elf_types<64>::Elf_Addr value,
2312     unsigned char* view,
2313     section_size_type view_size)
2314 {
2315   if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
2316     {
2317       // leaq foo@tlsdesc(%rip), %rax
2318       // ==> movq foo@tpoff, %rax
2319       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
2320       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
2321       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2322                      view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05);
2323       view[-2] = 0xc7;
2324       view[-1] = 0xc0;
2325       value -= tls_segment->memsz();
2326       Relocate_functions<64, false>::rela32(view, value, 0);
2327     }
2328   else
2329     {
2330       // call *foo@tlscall(%rax)
2331       // ==> nop; nop
2332       gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
2333       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
2334       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2335                      view[0] == 0xff && view[1] == 0x10);
2336       view[0] = 0x66;
2337       view[1] = 0x90;
2338     }
2339 }
2340
2341 inline void
2342 Target_x86_64::Relocate::tls_ld_to_le(const Relocate_info<64, false>* relinfo,
2343                                       size_t relnum,
2344                                       Output_segment*,
2345                                       const elfcpp::Rela<64, false>& rela,
2346                                       unsigned int,
2347                                       elfcpp::Elf_types<64>::Elf_Addr,
2348                                       unsigned char* view,
2349                                       section_size_type view_size)
2350 {
2351   // leaq foo@tlsld(%rip),%rdi; call __tls_get_addr@plt;
2352   // ... leq foo@dtpoff(%rax),%reg
2353   // ==> .word 0x6666; .byte 0x66; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
2354
2355   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
2356   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 9);
2357
2358   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
2359                  view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x3d);
2360
2361   tls::check_tls(relinfo, relnum, rela.get_r_offset(), view[4] == 0xe8);
2362
2363   memcpy(view - 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12);
2364
2365   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2366   // We can skip it.
2367   this->skip_call_tls_get_addr_ = true;
2368 }
2369
2370 // Do a relocation in which we convert a TLS Initial-Exec to a
2371 // Local-Exec.
2372
2373 inline void
2374 Target_x86_64::Relocate::tls_ie_to_le(const Relocate_info<64, false>* relinfo,
2375                                       size_t relnum,
2376                                       Output_segment* tls_segment,
2377                                       const elfcpp::Rela<64, false>& rela,
2378                                       unsigned int,
2379                                       elfcpp::Elf_types<64>::Elf_Addr value,
2380                                       unsigned char* view,
2381                                       section_size_type view_size)
2382 {
2383   // We need to examine the opcodes to figure out which instruction we
2384   // are looking at.
2385
2386   // movq foo@gottpoff(%rip),%reg  ==>  movq $YY,%reg
2387   // addq foo@gottpoff(%rip),%reg  ==>  addq $YY,%reg
2388
2389   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
2390   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
2391
2392   unsigned char op1 = view[-3];
2393   unsigned char op2 = view[-2];
2394   unsigned char op3 = view[-1];
2395   unsigned char reg = op3 >> 3;
2396
2397   if (op2 == 0x8b)
2398     {
2399       // movq
2400       if (op1 == 0x4c)
2401         view[-3] = 0x49;
2402       view[-2] = 0xc7;
2403       view[-1] = 0xc0 | reg;
2404     }
2405   else if (reg == 4)
2406     {
2407       // Special handling for %rsp.
2408       if (op1 == 0x4c)
2409         view[-3] = 0x49;
2410       view[-2] = 0x81;
2411       view[-1] = 0xc0 | reg;
2412     }
2413   else
2414     {
2415       // addq
2416       if (op1 == 0x4c)
2417         view[-3] = 0x4d;
2418       view[-2] = 0x8d;
2419       view[-1] = 0x80 | reg | (reg << 3);
2420     }
2421
2422   value -= tls_segment->memsz();
2423   Relocate_functions<64, false>::rela32(view, value, 0);
2424 }
2425
2426 // Relocate section data.
2427
2428 void
2429 Target_x86_64::relocate_section(
2430     const Relocate_info<64, false>* relinfo,
2431     unsigned int sh_type,
2432     const unsigned char* prelocs,
2433     size_t reloc_count,
2434     Output_section* output_section,
2435     bool needs_special_offset_handling,
2436     unsigned char* view,
2437     elfcpp::Elf_types<64>::Elf_Addr address,
2438     section_size_type view_size,
2439     const Reloc_symbol_changes* reloc_symbol_changes)
2440 {
2441   gold_assert(sh_type == elfcpp::SHT_RELA);
2442
2443   gold::relocate_section<64, false, Target_x86_64, elfcpp::SHT_RELA,
2444                          Target_x86_64::Relocate>(
2445     relinfo,
2446     this,
2447     prelocs,
2448     reloc_count,
2449     output_section,
2450     needs_special_offset_handling,
2451     view,
2452     address,
2453     view_size,
2454     reloc_symbol_changes);
2455 }
2456
2457 // Return the size of a relocation while scanning during a relocatable
2458 // link.
2459
2460 unsigned int
2461 Target_x86_64::Relocatable_size_for_reloc::get_size_for_reloc(
2462     unsigned int r_type,
2463     Relobj* object)
2464 {
2465   switch (r_type)
2466     {
2467     case elfcpp::R_X86_64_NONE:
2468     case elfcpp::R_386_GNU_VTINHERIT:
2469     case elfcpp::R_386_GNU_VTENTRY:
2470     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
2471     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
2472     case elfcpp::R_X86_64_TLSDESC_CALL:
2473     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
2474     case elfcpp::R_X86_64_DTPOFF32:
2475     case elfcpp::R_X86_64_DTPOFF64:
2476     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
2477     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
2478       return 0;
2479
2480     case elfcpp::R_X86_64_64:
2481     case elfcpp::R_X86_64_PC64:
2482     case elfcpp::R_X86_64_GOTOFF64:
2483     case elfcpp::R_X86_64_GOTPC64:
2484     case elfcpp::R_X86_64_PLTOFF64:
2485     case elfcpp::R_X86_64_GOT64:
2486     case elfcpp::R_X86_64_GOTPCREL64:
2487     case elfcpp::R_X86_64_GOTPCREL:
2488     case elfcpp::R_X86_64_GOTPLT64:
2489       return 8;
2490
2491     case elfcpp::R_X86_64_32:
2492     case elfcpp::R_X86_64_32S:
2493     case elfcpp::R_X86_64_PC32:
2494     case elfcpp::R_X86_64_PLT32:
2495     case elfcpp::R_X86_64_GOTPC32:
2496     case elfcpp::R_X86_64_GOT32:
2497       return 4;
2498
2499     case elfcpp::R_X86_64_16:
2500     case elfcpp::R_X86_64_PC16:
2501       return 2;
2502
2503     case elfcpp::R_X86_64_8:
2504     case elfcpp::R_X86_64_PC8:
2505       return 1;
2506
2507     case elfcpp::R_X86_64_COPY:
2508     case elfcpp::R_X86_64_GLOB_DAT:
2509     case elfcpp::R_X86_64_JUMP_SLOT:
2510     case elfcpp::R_X86_64_RELATIVE:
2511       // These are outstanding tls relocs, which are unexpected when linking
2512     case elfcpp::R_X86_64_TPOFF64:
2513     case elfcpp::R_X86_64_DTPMOD64:
2514     case elfcpp::R_X86_64_TLSDESC:
2515       object->error(_("unexpected reloc %u in object file"), r_type);
2516       return 0;
2517
2518     case elfcpp::R_X86_64_SIZE32:
2519     case elfcpp::R_X86_64_SIZE64:
2520     default:
2521       object->error(_("unsupported reloc %u against local symbol"), r_type);
2522       return 0;
2523     }
2524 }
2525
2526 // Scan the relocs during a relocatable link.
2527
2528 void
2529 Target_x86_64::scan_relocatable_relocs(Symbol_table* symtab,
2530                                        Layout* layout,
2531                                        Sized_relobj<64, false>* object,
2532                                        unsigned int data_shndx,
2533                                        unsigned int sh_type,
2534                                        const unsigned char* prelocs,
2535                                        size_t reloc_count,
2536                                        Output_section* output_section,
2537                                        bool needs_special_offset_handling,
2538                                        size_t local_symbol_count,
2539                                        const unsigned char* plocal_symbols,
2540                                        Relocatable_relocs* rr)
2541 {
2542   gold_assert(sh_type == elfcpp::SHT_RELA);
2543
2544   typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_RELA,
2545     Relocatable_size_for_reloc> Scan_relocatable_relocs;
2546
2547   gold::scan_relocatable_relocs<64, false, elfcpp::SHT_RELA,
2548       Scan_relocatable_relocs>(
2549     symtab,
2550     layout,
2551     object,
2552     data_shndx,
2553     prelocs,
2554     reloc_count,
2555     output_section,
2556     needs_special_offset_handling,
2557     local_symbol_count,
2558     plocal_symbols,
2559     rr);
2560 }
2561
2562 // Relocate a section during a relocatable link.
2563
2564 void
2565 Target_x86_64::relocate_for_relocatable(
2566     const Relocate_info<64, false>* relinfo,
2567     unsigned int sh_type,
2568     const unsigned char* prelocs,
2569     size_t reloc_count,
2570     Output_section* output_section,
2571     off_t offset_in_output_section,
2572     const Relocatable_relocs* rr,
2573     unsigned char* view,
2574     elfcpp::Elf_types<64>::Elf_Addr view_address,
2575     section_size_type view_size,
2576     unsigned char* reloc_view,
2577     section_size_type reloc_view_size)
2578 {
2579   gold_assert(sh_type == elfcpp::SHT_RELA);
2580
2581   gold::relocate_for_relocatable<64, false, elfcpp::SHT_RELA>(
2582     relinfo,
2583     prelocs,
2584     reloc_count,
2585     output_section,
2586     offset_in_output_section,
2587     rr,
2588     view,
2589     view_address,
2590     view_size,
2591     reloc_view,
2592     reloc_view_size);
2593 }
2594
2595 // Return the value to use for a dynamic which requires special
2596 // treatment.  This is how we support equality comparisons of function
2597 // pointers across shared library boundaries, as described in the
2598 // processor specific ABI supplement.
2599
2600 uint64_t
2601 Target_x86_64::do_dynsym_value(const Symbol* gsym) const
2602 {
2603   gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
2604   return this->plt_section()->address() + gsym->plt_offset();
2605 }
2606
2607 // Return a string used to fill a code section with nops to take up
2608 // the specified length.
2609
2610 std::string
2611 Target_x86_64::do_code_fill(section_size_type length) const
2612 {
2613   if (length >= 16)
2614     {
2615       // Build a jmpq instruction to skip over the bytes.
2616       unsigned char jmp[5];
2617       jmp[0] = 0xe9;
2618       elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
2619       return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
2620               + std::string(length - 5, '\0'));
2621     }
2622
2623   // Nop sequences of various lengths.
2624   const char nop1[1] = { 0x90 };                   // nop
2625   const char nop2[2] = { 0x66, 0x90 };             // xchg %ax %ax
2626   const char nop3[3] = { 0x0f, 0x1f, 0x00 };       // nop (%rax)
2627   const char nop4[4] = { 0x0f, 0x1f, 0x40, 0x00};  // nop 0(%rax)
2628   const char nop5[5] = { 0x0f, 0x1f, 0x44, 0x00,   // nop 0(%rax,%rax,1)
2629                          0x00 };
2630   const char nop6[6] = { 0x66, 0x0f, 0x1f, 0x44,   // nopw 0(%rax,%rax,1)
2631                          0x00, 0x00 };
2632   const char nop7[7] = { 0x0f, 0x1f, 0x80, 0x00,   // nopl 0L(%rax)
2633                          0x00, 0x00, 0x00 };
2634   const char nop8[8] = { 0x0f, 0x1f, 0x84, 0x00,   // nopl 0L(%rax,%rax,1)
2635                          0x00, 0x00, 0x00, 0x00 };
2636   const char nop9[9] = { 0x66, 0x0f, 0x1f, 0x84,   // nopw 0L(%rax,%rax,1)
2637                          0x00, 0x00, 0x00, 0x00,
2638                          0x00 };
2639   const char nop10[10] = { 0x66, 0x2e, 0x0f, 0x1f, // nopw %cs:0L(%rax,%rax,1)
2640                            0x84, 0x00, 0x00, 0x00,
2641                            0x00, 0x00 };
2642   const char nop11[11] = { 0x66, 0x66, 0x2e, 0x0f, // data16
2643                            0x1f, 0x84, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
2644                            0x00, 0x00, 0x00 };
2645   const char nop12[12] = { 0x66, 0x66, 0x66, 0x2e, // data16; data16
2646                            0x0f, 0x1f, 0x84, 0x00, // nopw %cs:0L(%rax,%rax,1)
2647                            0x00, 0x00, 0x00, 0x00 };
2648   const char nop13[13] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
2649                            0x2e, 0x0f, 0x1f, 0x84, // nopw %cs:0L(%rax,%rax,1)
2650                            0x00, 0x00, 0x00, 0x00,
2651                            0x00 };
2652   const char nop14[14] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
2653                            0x66, 0x2e, 0x0f, 0x1f, // data16
2654                            0x84, 0x00, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
2655                            0x00, 0x00 };
2656   const char nop15[15] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
2657                            0x66, 0x66, 0x2e, 0x0f, // data16; data16
2658                            0x1f, 0x84, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
2659                            0x00, 0x00, 0x00 };
2660
2661   const char* nops[16] = {
2662     NULL,
2663     nop1, nop2, nop3, nop4, nop5, nop6, nop7,
2664     nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
2665   };
2666
2667   return std::string(nops[length], length);
2668 }
2669
2670 // FNOFFSET in section SHNDX in OBJECT is the start of a function
2671 // compiled with -fstack-split.  The function calls non-stack-split
2672 // code.  We have to change the function so that it always ensures
2673 // that it has enough stack space to run some random function.
2674
2675 void
2676 Target_x86_64::do_calls_non_split(Relobj* object, unsigned int shndx,
2677                                   section_offset_type fnoffset,
2678                                   section_size_type fnsize,
2679                                   unsigned char* view,
2680                                   section_size_type view_size,
2681                                   std::string* from,
2682                                   std::string* to) const
2683 {
2684   // The function starts with a comparison of the stack pointer and a
2685   // field in the TCB.  This is followed by a jump.
2686
2687   // cmp %fs:NN,%rsp
2688   if (this->match_view(view, view_size, fnoffset, "\x64\x48\x3b\x24\x25", 5)
2689       && fnsize > 9)
2690     {
2691       // We will call __morestack if the carry flag is set after this
2692       // comparison.  We turn the comparison into an stc instruction
2693       // and some nops.
2694       view[fnoffset] = '\xf9';
2695       this->set_view_to_nop(view, view_size, fnoffset + 1, 8);
2696     }
2697   // lea NN(%rsp),%r10
2698   // lea NN(%rsp),%r11
2699   else if ((this->match_view(view, view_size, fnoffset,
2700                              "\x4c\x8d\x94\x24", 4)
2701             || this->match_view(view, view_size, fnoffset,
2702                                 "\x4c\x8d\x9c\x24", 4))
2703            && fnsize > 8)
2704     {
2705       // This is loading an offset from the stack pointer for a
2706       // comparison.  The offset is negative, so we decrease the
2707       // offset by the amount of space we need for the stack.  This
2708       // means we will avoid calling __morestack if there happens to
2709       // be plenty of space on the stack already.
2710       unsigned char* pval = view + fnoffset + 4;
2711       uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
2712       val -= parameters->options().split_stack_adjust_size();
2713       elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
2714     }
2715   else
2716     {
2717       if (!object->has_no_split_stack())
2718         object->error(_("failed to match split-stack sequence at "
2719                         "section %u offset %0zx"),
2720                       shndx, static_cast<size_t>(fnoffset));
2721       return;
2722     }
2723
2724   // We have to change the function so that it calls
2725   // __morestack_non_split instead of __morestack.  The former will
2726   // allocate additional stack space.
2727   *from = "__morestack";
2728   *to = "__morestack_non_split";
2729 }
2730
2731 // The selector for x86_64 object files.
2732
2733 class Target_selector_x86_64 : public Target_selector_freebsd
2734 {
2735 public:
2736   Target_selector_x86_64()
2737     : Target_selector_freebsd(elfcpp::EM_X86_64, 64, false, "elf64-x86-64",
2738                               "elf64-x86-64-freebsd")
2739   { }
2740
2741   Target*
2742   do_instantiate_target()
2743   { return new Target_x86_64(); }
2744
2745 };
2746
2747 Target_selector_x86_64 target_selector_x86_64;
2748
2749 } // End anonymous namespace.