gold/x86_64.cc

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