contrib/binutils-2.22/gold/x86_64.cc

   1 // x86_64.cc -- x86_64 target support for gold.
   2
   3 // Copyright 2006, 2007, 2008, 2009, 2010, 2011 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 "dwarf.h"
  29 #include "parameters.h"
  30 #include "reloc.h"
  31 #include "x86_64.h"
  32 #include "object.h"
  33 #include "symtab.h"
  34 #include "layout.h"
  35 #include "output.h"
  36 #include "copy-relocs.h"
  37 #include "target.h"
  38 #include "target-reloc.h"
  39 #include "target-select.h"
  40 #include "tls.h"
  41 #include "freebsd.h"
  42 #include "gc.h"
  43 #include "icf.h"
  44
  45 namespace
  46 {
  47
  48 using namespace gold;
  49
  50 // A class to handle the PLT data.
  51
  52 class Output_data_plt_x86_64 : public Output_section_data
  53 {
  54  public:
  55   typedef Output_data_reloc<elfcpp::SHT_RELA, true, 64, false> Reloc_section;
  56
  57   Output_data_plt_x86_64(Layout* layout, Output_data_got<64, false>* got,
  58                          Output_data_space* got_plt,
  59                          Output_data_space* got_irelative)
  60     : Output_section_data(16), layout_(layout), tlsdesc_rel_(NULL),
  61       irelative_rel_(NULL), got_(got), got_plt_(got_plt),
  62       got_irelative_(got_irelative), count_(0), irelative_count_(0),
  63       tlsdesc_got_offset_(-1U), free_list_()
  64   { this->init(layout); }
  65
  66   Output_data_plt_x86_64(Layout* layout, Output_data_got<64, false>* got,
  67                          Output_data_space* got_plt,
  68                          Output_data_space* got_irelative,
  69                          unsigned int plt_count)
  70     : Output_section_data((plt_count + 1) * plt_entry_size, 16, false),
  71       layout_(layout), tlsdesc_rel_(NULL), irelative_rel_(NULL), got_(got),
  72       got_plt_(got_plt), got_irelative_(got_irelative), count_(plt_count),
  73       irelative_count_(0), tlsdesc_got_offset_(-1U), free_list_()
  74   {
  75     this->init(layout);
  76
  77     // Initialize the free list and reserve the first entry.
  78     this->free_list_.init((plt_count + 1) * plt_entry_size, false);
  79     this->free_list_.remove(0, plt_entry_size);
  80   }
  81
  82   // Initialize the PLT section.
  83   void
  84   init(Layout* layout);
  85
  86   // Add an entry to the PLT.
  87   void
  88   add_entry(Symbol_table*, Layout*, Symbol* gsym);
  89
  90   // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
  91   unsigned int
  92   add_local_ifunc_entry(Symbol_table* symtab, Layout*,
  93                         Sized_relobj_file<64, false>* relobj,
  94                         unsigned int local_sym_index);
  95
  96   // Add the relocation for a PLT entry.
  97   void
  98   add_relocation(Symbol_table*, Layout*, Symbol* gsym,
  99                  unsigned int got_offset);
 100
 101   // Add the reserved TLSDESC_PLT entry to the PLT.
 102   void
 103   reserve_tlsdesc_entry(unsigned int got_offset)
 104   { this->tlsdesc_got_offset_ = got_offset; }
 105
 106   // Return true if a TLSDESC_PLT entry has been reserved.
 107   bool
 108   has_tlsdesc_entry() const
 109   { return this->tlsdesc_got_offset_ != -1U; }
 110
 111   // Return the GOT offset for the reserved TLSDESC_PLT entry.
 112   unsigned int
 113   get_tlsdesc_got_offset() const
 114   { return this->tlsdesc_got_offset_; }
 115
 116   // Return the offset of the reserved TLSDESC_PLT entry.
 117   unsigned int
 118   get_tlsdesc_plt_offset() const
 119   { return (this->count_ + this->irelative_count_ + 1) * plt_entry_size; }
 120
 121   // Return the .rela.plt section data.
 122   Reloc_section*
 123   rela_plt()
 124   { return this->rel_; }
 125
 126   // Return where the TLSDESC relocations should go.
 127   Reloc_section*
 128   rela_tlsdesc(Layout*);
 129
 130   // Return where the IRELATIVE relocations should go in the PLT
 131   // relocations.
 132   Reloc_section*
 133   rela_irelative(Symbol_table*, Layout*);
 134
 135   // Return whether we created a section for IRELATIVE relocations.
 136   bool
 137   has_irelative_section() const
 138   { return this->irelative_rel_ != NULL; }
 139
 140   // Return the number of PLT entries.
 141   unsigned int
 142   entry_count() const
 143   { return this->count_ + this->irelative_count_; }
 144
 145   // Return the offset of the first non-reserved PLT entry.
 146   static unsigned int
 147   first_plt_entry_offset()
 148   { return plt_entry_size; }
 149
 150   // Return the size of a PLT entry.
 151   static unsigned int
 152   get_plt_entry_size()
 153   { return plt_entry_size; }
 154
 155   // Reserve a slot in the PLT for an existing symbol in an incremental update.
 156   void
 157   reserve_slot(unsigned int plt_index)
 158   {
 159     this->free_list_.remove((plt_index + 1) * plt_entry_size,
 160                             (plt_index + 2) * plt_entry_size);
 161   }
 162
 163   // Return the PLT address to use for a global symbol.
 164   uint64_t
 165   address_for_global(const Symbol*);
 166
 167   // Return the PLT address to use for a local symbol.
 168   uint64_t
 169   address_for_local(const Relobj*, unsigned int symndx);
 170
 171  protected:
 172   void
 173   do_adjust_output_section(Output_section* os);
 174
 175   // Write to a map file.
 176   void
 177   do_print_to_mapfile(Mapfile* mapfile) const
 178   { mapfile->print_output_data(this, _("** PLT")); }
 179
 180  private:
 181   // The size of an entry in the PLT.
 182   static const int plt_entry_size = 16;
 183
 184   // The first entry in the PLT.
 185   // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
 186   // procedure linkage table for both programs and shared objects."
 187   static const unsigned char first_plt_entry[plt_entry_size];
 188
 189   // Other entries in the PLT for an executable.
 190   static const unsigned char plt_entry[plt_entry_size];
 191
 192   // The reserved TLSDESC entry in the PLT for an executable.
 193   static const unsigned char tlsdesc_plt_entry[plt_entry_size];
 194
 195   // The .eh_frame unwind information for the PLT.
 196   static const int plt_eh_frame_cie_size = 16;
 197   static const int plt_eh_frame_fde_size = 32;
 198   static const unsigned char plt_eh_frame_cie[plt_eh_frame_cie_size];
 199   static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
 200
 201   // Set the final size.
 202   void
 203   set_final_data_size();
 204
 205   // Write out the PLT data.
 206   void
 207   do_write(Output_file*);
 208
 209   // A pointer to the Layout class, so that we can find the .dynamic
 210   // section when we write out the GOT PLT section.
 211   Layout* layout_;
 212   // The reloc section.
 213   Reloc_section* rel_;
 214   // The TLSDESC relocs, if necessary.  These must follow the regular
 215   // PLT relocs.
 216   Reloc_section* tlsdesc_rel_;
 217   // The IRELATIVE relocs, if necessary.  These must follow the
 218   // regular PLT relocations and the TLSDESC relocations.
 219   Reloc_section* irelative_rel_;
 220   // The .got section.
 221   Output_data_got<64, false>* got_;
 222   // The .got.plt section.
 223   Output_data_space* got_plt_;
 224   // The part of the .got.plt section used for IRELATIVE relocs.
 225   Output_data_space* got_irelative_;
 226   // The number of PLT entries.
 227   unsigned int count_;
 228   // Number of PLT entries with R_X86_64_IRELATIVE relocs.  These
 229   // follow the regular PLT entries.
 230   unsigned int irelative_count_;
 231   // Offset of the reserved TLSDESC_GOT entry when needed.
 232   unsigned int tlsdesc_got_offset_;
 233   // List of available regions within the section, for incremental
 234   // update links.
 235   Free_list free_list_;
 236 };
 237
 238 // The x86_64 target class.
 239 // See the ABI at
 240 //   http://www.x86-64.org/documentation/abi.pdf
 241 // TLS info comes from
 242 //   http://people.redhat.com/drepper/tls.pdf
 243 //   http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
 244
 245 class Target_x86_64 : public Sized_target<64, false>
 246 {
 247  public:
 248   // In the x86_64 ABI (p 68), it says "The AMD64 ABI architectures
 249   // uses only Elf64_Rela relocation entries with explicit addends."
 250   typedef Output_data_reloc<elfcpp::SHT_RELA, true, 64, false> Reloc_section;
 251
 252   Target_x86_64()
 253     : Sized_target<64, false>(&x86_64_info),
 254       got_(NULL), plt_(NULL), got_plt_(NULL), got_irelative_(NULL),
 255       got_tlsdesc_(NULL), global_offset_table_(NULL), rela_dyn_(NULL),
 256       rela_irelative_(NULL), copy_relocs_(elfcpp::R_X86_64_COPY),
 257       dynbss_(NULL), got_mod_index_offset_(-1U), tlsdesc_reloc_info_(),
 258       tls_base_symbol_defined_(false)
 259   { }
 260
 261   // Hook for a new output section.
 262   void
 263   do_new_output_section(Output_section*) const;
 264
 265   // Scan the relocations to look for symbol adjustments.
 266   void
 267   gc_process_relocs(Symbol_table* symtab,
 268                     Layout* layout,
 269                     Sized_relobj_file<64, false>* object,
 270                     unsigned int data_shndx,
 271                     unsigned int sh_type,
 272                     const unsigned char* prelocs,
 273                     size_t reloc_count,
 274                     Output_section* output_section,
 275                     bool needs_special_offset_handling,
 276                     size_t local_symbol_count,
 277                     const unsigned char* plocal_symbols);
 278
 279   // Scan the relocations to look for symbol adjustments.
 280   void
 281   scan_relocs(Symbol_table* symtab,
 282               Layout* layout,
 283               Sized_relobj_file<64, false>* object,
 284               unsigned int data_shndx,
 285               unsigned int sh_type,
 286               const unsigned char* prelocs,
 287               size_t reloc_count,
 288               Output_section* output_section,
 289               bool needs_special_offset_handling,
 290               size_t local_symbol_count,
 291               const unsigned char* plocal_symbols);
 292
 293   // Finalize the sections.
 294   void
 295   do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
 296
 297   // Return the value to use for a dynamic which requires special
 298   // treatment.
 299   uint64_t
 300   do_dynsym_value(const Symbol*) const;
 301
 302   // Relocate a section.
 303   void
 304   relocate_section(const Relocate_info<64, false>*,
 305                    unsigned int sh_type,
 306                    const unsigned char* prelocs,
 307                    size_t reloc_count,
 308                    Output_section* output_section,
 309                    bool needs_special_offset_handling,
 310                    unsigned char* view,
 311                    elfcpp::Elf_types<64>::Elf_Addr view_address,
 312                    section_size_type view_size,
 313                    const Reloc_symbol_changes*);
 314
 315   // Scan the relocs during a relocatable link.
 316   void
 317   scan_relocatable_relocs(Symbol_table* symtab,
 318                           Layout* layout,
 319                           Sized_relobj_file<64, false>* object,
 320                           unsigned int data_shndx,
 321                           unsigned int sh_type,
 322                           const unsigned char* prelocs,
 323                           size_t reloc_count,
 324                           Output_section* output_section,
 325                           bool needs_special_offset_handling,
 326                           size_t local_symbol_count,
 327                           const unsigned char* plocal_symbols,
 328                           Relocatable_relocs*);
 329
 330   // Relocate a section during a relocatable link.
 331   void
 332   relocate_for_relocatable(const Relocate_info<64, false>*,
 333                            unsigned int sh_type,
 334                            const unsigned char* prelocs,
 335                            size_t reloc_count,
 336                            Output_section* output_section,
 337                            off_t offset_in_output_section,
 338                            const Relocatable_relocs*,
 339                            unsigned char* view,
 340                            elfcpp::Elf_types<64>::Elf_Addr view_address,
 341                            section_size_type view_size,
 342                            unsigned char* reloc_view,
 343                            section_size_type reloc_view_size);
 344
 345   // Return a string used to fill a code section with nops.
 346   std::string
 347   do_code_fill(section_size_type length) const;
 348
 349   // Return whether SYM is defined by the ABI.
 350   bool
 351   do_is_defined_by_abi(const Symbol* sym) const
 352   { return strcmp(sym->name(), "__tls_get_addr") == 0; }
 353
 354   // Return the symbol index to use for a target specific relocation.
 355   // The only target specific relocation is R_X86_64_TLSDESC for a
 356   // local symbol, which is an absolute reloc.
 357   unsigned int
 358   do_reloc_symbol_index(void*, unsigned int r_type) const
 359   {
 360     gold_assert(r_type == elfcpp::R_X86_64_TLSDESC);
 361     return 0;
 362   }
 363
 364   // Return the addend to use for a target specific relocation.
 365   uint64_t
 366   do_reloc_addend(void* arg, unsigned int r_type, uint64_t addend) const;
 367
 368   // Return the PLT section.
 369   uint64_t
 370   do_plt_address_for_global(const Symbol* gsym) const
 371   { return this->plt_section()->address_for_global(gsym); }
 372
 373   uint64_t
 374   do_plt_address_for_local(const Relobj* relobj, unsigned int symndx) const
 375   { return this->plt_section()->address_for_local(relobj, symndx); }
 376
 377   // This function should be defined in targets that can use relocation
 378   // types to determine (implemented in local_reloc_may_be_function_pointer
 379   // and global_reloc_may_be_function_pointer)
 380   // if a function's pointer is taken.  ICF uses this in safe mode to only
 381   // fold those functions whose pointer is defintely not taken.  For x86_64
 382   // pie binaries, safe ICF cannot be done by looking at relocation types.
 383   bool
 384   do_can_check_for_function_pointers() const
 385   { return !parameters->options().pie(); }
 386
 387   // Return the base for a DW_EH_PE_datarel encoding.
 388   uint64_t
 389   do_ehframe_datarel_base() const;
 390
 391   // Adjust -fsplit-stack code which calls non-split-stack code.
 392   void
 393   do_calls_non_split(Relobj* object, unsigned int shndx,
 394                      section_offset_type fnoffset, section_size_type fnsize,
 395                      unsigned char* view, section_size_type view_size,
 396                      std::string* from, std::string* to) const;
 397
 398   // Return the size of the GOT section.
 399   section_size_type
 400   got_size() const
 401   {
 402     gold_assert(this->got_ != NULL);
 403     return this->got_->data_size();
 404   }
 405
 406   // Return the number of entries in the GOT.
 407   unsigned int
 408   got_entry_count() const
 409   {
 410     if (this->got_ == NULL)
 411       return 0;
 412     return this->got_size() / 8;
 413   }
 414
 415   // Return the number of entries in the PLT.
 416   unsigned int
 417   plt_entry_count() const;
 418
 419   // Return the offset of the first non-reserved PLT entry.
 420   unsigned int
 421   first_plt_entry_offset() const;
 422
 423   // Return the size of each PLT entry.
 424   unsigned int
 425   plt_entry_size() const;
 426
 427   // Create the GOT section for an incremental update.
 428   Output_data_got<64, false>*
 429   init_got_plt_for_update(Symbol_table* symtab,
 430                           Layout* layout,
 431                           unsigned int got_count,
 432                           unsigned int plt_count);
 433
 434   // Reserve a GOT entry for a local symbol, and regenerate any
 435   // necessary dynamic relocations.
 436   void
 437   reserve_local_got_entry(unsigned int got_index,
 438                           Sized_relobj<64, false>* obj,
 439                           unsigned int r_sym,
 440                           unsigned int got_type);
 441
 442   // Reserve a GOT entry for a global symbol, and regenerate any
 443   // necessary dynamic relocations.
 444   void
 445   reserve_global_got_entry(unsigned int got_index, Symbol* gsym,
 446                            unsigned int got_type);
 447
 448   // Register an existing PLT entry for a global symbol.
 449   void
 450   register_global_plt_entry(Symbol_table*, Layout*, unsigned int plt_index,
 451                             Symbol* gsym);
 452
 453   // Force a COPY relocation for a given symbol.
 454   void
 455   emit_copy_reloc(Symbol_table*, Symbol*, Output_section*, off_t);
 456
 457   // Apply an incremental relocation.
 458   void
 459   apply_relocation(const Relocate_info<64, false>* relinfo,
 460                    elfcpp::Elf_types<64>::Elf_Addr r_offset,
 461                    unsigned int r_type,
 462                    elfcpp::Elf_types<64>::Elf_Swxword r_addend,
 463                    const Symbol* gsym,
 464                    unsigned char* view,
 465                    elfcpp::Elf_types<64>::Elf_Addr address,
 466                    section_size_type view_size);
 467
 468   // Add a new reloc argument, returning the index in the vector.
 469   size_t
 470   add_tlsdesc_info(Sized_relobj_file<64, false>* object, unsigned int r_sym)
 471   {
 472     this->tlsdesc_reloc_info_.push_back(Tlsdesc_info(object, r_sym));
 473     return this->tlsdesc_reloc_info_.size() - 1;
 474   }
 475
 476  private:
 477   // The class which scans relocations.
 478   class Scan
 479   {
 480   public:
 481     Scan()
 482       : issued_non_pic_error_(false)
 483     { }
 484
 485     static inline int
 486     get_reference_flags(unsigned int r_type);
 487
 488     inline void
 489     local(Symbol_table* symtab, Layout* layout, Target_x86_64* target,
 490           Sized_relobj_file<64, false>* object,
 491           unsigned int data_shndx,
 492           Output_section* output_section,
 493           const elfcpp::Rela<64, false>& reloc, unsigned int r_type,
 494           const elfcpp::Sym<64, false>& lsym);
 495
 496     inline void
 497     global(Symbol_table* symtab, Layout* layout, Target_x86_64* target,
 498            Sized_relobj_file<64, false>* object,
 499            unsigned int data_shndx,
 500            Output_section* output_section,
 501            const elfcpp::Rela<64, false>& reloc, unsigned int r_type,
 502            Symbol* gsym);
 503
 504     inline bool
 505     local_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
 506                                         Target_x86_64* target,
 507                                         Sized_relobj_file<64, false>* object,
 508                                         unsigned int data_shndx,
 509                                         Output_section* output_section,
 510                                         const elfcpp::Rela<64, false>& reloc,
 511                                         unsigned int r_type,
 512                                         const elfcpp::Sym<64, false>& lsym);
 513
 514     inline bool
 515     global_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
 516                                          Target_x86_64* target,
 517                                          Sized_relobj_file<64, false>* object,
 518                                          unsigned int data_shndx,
 519                                          Output_section* output_section,
 520                                          const elfcpp::Rela<64, false>& reloc,
 521                                          unsigned int r_type,
 522                                          Symbol* gsym);
 523
 524   private:
 525     static void
 526     unsupported_reloc_local(Sized_relobj_file<64, false>*, unsigned int r_type);
 527
 528     static void
 529     unsupported_reloc_global(Sized_relobj_file<64, false>*, unsigned int r_type,
 530                              Symbol*);
 531
 532     void
 533     check_non_pic(Relobj*, unsigned int r_type, Symbol*);
 534
 535     inline bool
 536     possible_function_pointer_reloc(unsigned int r_type);
 537
 538     bool
 539     reloc_needs_plt_for_ifunc(Sized_relobj_file<64, false>*,
 540                               unsigned int r_type);
 541
 542     // Whether we have issued an error about a non-PIC compilation.
 543     bool issued_non_pic_error_;
 544   };
 545
 546   // The class which implements relocation.
 547   class Relocate
 548   {
 549    public:
 550     Relocate()
 551       : skip_call_tls_get_addr_(false)
 552     { }
 553
 554     ~Relocate()
 555     {
 556       if (this->skip_call_tls_get_addr_)
 557         {
 558           // FIXME: This needs to specify the location somehow.
 559           gold_error(_("missing expected TLS relocation"));
 560         }
 561     }
 562
 563     // Do a relocation.  Return false if the caller should not issue
 564     // any warnings about this relocation.
 565     inline bool
 566     relocate(const Relocate_info<64, false>*, Target_x86_64*, Output_section*,
 567              size_t relnum, const elfcpp::Rela<64, false>&,
 568              unsigned int r_type, const Sized_symbol<64>*,
 569              const Symbol_value<64>*,
 570              unsigned char*, elfcpp::Elf_types<64>::Elf_Addr,
 571              section_size_type);
 572
 573    private:
 574     // Do a TLS relocation.
 575     inline void
 576     relocate_tls(const Relocate_info<64, false>*, Target_x86_64*,
 577                  size_t relnum, const elfcpp::Rela<64, false>&,
 578                  unsigned int r_type, const Sized_symbol<64>*,
 579                  const Symbol_value<64>*,
 580                  unsigned char*, elfcpp::Elf_types<64>::Elf_Addr,
 581                  section_size_type);
 582
 583     // Do a TLS General-Dynamic to Initial-Exec transition.
 584     inline void
 585     tls_gd_to_ie(const Relocate_info<64, false>*, size_t relnum,
 586                  Output_segment* tls_segment,
 587                  const elfcpp::Rela<64, false>&, unsigned int r_type,
 588                  elfcpp::Elf_types<64>::Elf_Addr value,
 589                  unsigned char* view,
 590                  elfcpp::Elf_types<64>::Elf_Addr,
 591                  section_size_type view_size);
 592
 593     // Do a TLS General-Dynamic to Local-Exec transition.
 594     inline void
 595     tls_gd_to_le(const Relocate_info<64, false>*, size_t relnum,
 596                  Output_segment* tls_segment,
 597                  const elfcpp::Rela<64, false>&, unsigned int r_type,
 598                  elfcpp::Elf_types<64>::Elf_Addr value,
 599                  unsigned char* view,
 600                  section_size_type view_size);
 601
 602     // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
 603     inline void
 604     tls_desc_gd_to_ie(const Relocate_info<64, false>*, size_t relnum,
 605                       Output_segment* tls_segment,
 606                       const elfcpp::Rela<64, false>&, unsigned int r_type,
 607                       elfcpp::Elf_types<64>::Elf_Addr value,
 608                       unsigned char* view,
 609                       elfcpp::Elf_types<64>::Elf_Addr,
 610                       section_size_type view_size);
 611
 612     // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
 613     inline void
 614     tls_desc_gd_to_le(const Relocate_info<64, false>*, size_t relnum,
 615                       Output_segment* tls_segment,
 616                       const elfcpp::Rela<64, false>&, unsigned int r_type,
 617                       elfcpp::Elf_types<64>::Elf_Addr value,
 618                       unsigned char* view,
 619                       section_size_type view_size);
 620
 621     // Do a TLS Local-Dynamic to Local-Exec transition.
 622     inline void
 623     tls_ld_to_le(const Relocate_info<64, false>*, size_t relnum,
 624                  Output_segment* tls_segment,
 625                  const elfcpp::Rela<64, false>&, unsigned int r_type,
 626                  elfcpp::Elf_types<64>::Elf_Addr value,
 627                  unsigned char* view,
 628                  section_size_type view_size);
 629
 630     // Do a TLS Initial-Exec to Local-Exec transition.
 631     static inline void
 632     tls_ie_to_le(const Relocate_info<64, false>*, size_t relnum,
 633                  Output_segment* tls_segment,
 634                  const elfcpp::Rela<64, false>&, unsigned int r_type,
 635                  elfcpp::Elf_types<64>::Elf_Addr value,
 636                  unsigned char* view,
 637                  section_size_type view_size);
 638
 639     // This is set if we should skip the next reloc, which should be a
 640     // PLT32 reloc against ___tls_get_addr.
 641     bool skip_call_tls_get_addr_;
 642   };
 643
 644   // A class which returns the size required for a relocation type,
 645   // used while scanning relocs during a relocatable link.
 646   class Relocatable_size_for_reloc
 647   {
 648    public:
 649     unsigned int
 650     get_size_for_reloc(unsigned int, Relobj*);
 651   };
 652
 653   // Adjust TLS relocation type based on the options and whether this
 654   // is a local symbol.
 655   static tls::Tls_optimization
 656   optimize_tls_reloc(bool is_final, int r_type);
 657
 658   // Get the GOT section, creating it if necessary.
 659   Output_data_got<64, false>*
 660   got_section(Symbol_table*, Layout*);
 661
 662   // Get the GOT PLT section.
 663   Output_data_space*
 664   got_plt_section() const
 665   {
 666     gold_assert(this->got_plt_ != NULL);
 667     return this->got_plt_;
 668   }
 669
 670   // Get the GOT section for TLSDESC entries.
 671   Output_data_got<64, false>*
 672   got_tlsdesc_section() const
 673   {
 674     gold_assert(this->got_tlsdesc_ != NULL);
 675     return this->got_tlsdesc_;
 676   }
 677
 678   // Create the PLT section.
 679   void
 680   make_plt_section(Symbol_table* symtab, Layout* layout);
 681
 682   // Create a PLT entry for a global symbol.
 683   void
 684   make_plt_entry(Symbol_table*, Layout*, Symbol*);
 685
 686   // Create a PLT entry for a local STT_GNU_IFUNC symbol.
 687   void
 688   make_local_ifunc_plt_entry(Symbol_table*, Layout*,
 689                              Sized_relobj_file<64, false>* relobj,
 690                              unsigned int local_sym_index);
 691
 692   // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
 693   void
 694   define_tls_base_symbol(Symbol_table*, Layout*);
 695
 696   // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
 697   void
 698   reserve_tlsdesc_entries(Symbol_table* symtab, Layout* layout);
 699
 700   // Create a GOT entry for the TLS module index.
 701   unsigned int
 702   got_mod_index_entry(Symbol_table* symtab, Layout* layout,
 703                       Sized_relobj_file<64, false>* object);
 704
 705   // Get the PLT section.
 706   Output_data_plt_x86_64*
 707   plt_section() const
 708   {
 709     gold_assert(this->plt_ != NULL);
 710     return this->plt_;
 711   }
 712
 713   // Get the dynamic reloc section, creating it if necessary.
 714   Reloc_section*
 715   rela_dyn_section(Layout*);
 716
 717   // Get the section to use for TLSDESC relocations.
 718   Reloc_section*
 719   rela_tlsdesc_section(Layout*) const;
 720
 721   // Get the section to use for IRELATIVE relocations.
 722   Reloc_section*
 723   rela_irelative_section(Layout*);
 724
 725   // Add a potential copy relocation.
 726   void
 727   copy_reloc(Symbol_table* symtab, Layout* layout,
 728              Sized_relobj_file<64, false>* object,
 729              unsigned int shndx, Output_section* output_section,
 730              Symbol* sym, const elfcpp::Rela<64, false>& reloc)
 731   {
 732     this->copy_relocs_.copy_reloc(symtab, layout,
 733                                   symtab->get_sized_symbol<64>(sym),
 734                                   object, shndx, output_section,
 735                                   reloc, this->rela_dyn_section(layout));
 736   }
 737
 738   // Information about this specific target which we pass to the
 739   // general Target structure.
 740   static const Target::Target_info x86_64_info;
 741
 742   // The types of GOT entries needed for this platform.
 743   // These values are exposed to the ABI in an incremental link.
 744   // Do not renumber existing values without changing the version
 745   // number of the .gnu_incremental_inputs section.
 746   enum Got_type
 747   {
 748     GOT_TYPE_STANDARD = 0,      // GOT entry for a regular symbol
 749     GOT_TYPE_TLS_OFFSET = 1,    // GOT entry for TLS offset
 750     GOT_TYPE_TLS_PAIR = 2,      // GOT entry for TLS module/offset pair
 751     GOT_TYPE_TLS_DESC = 3       // GOT entry for TLS_DESC pair
 752   };
 753
 754   // This type is used as the argument to the target specific
 755   // relocation routines.  The only target specific reloc is
 756   // R_X86_64_TLSDESC against a local symbol.
 757   struct Tlsdesc_info
 758   {
 759     Tlsdesc_info(Sized_relobj_file<64, false>* a_object, unsigned int a_r_sym)
 760       : object(a_object), r_sym(a_r_sym)
 761     { }
 762
 763     // The object in which the local symbol is defined.
 764     Sized_relobj_file<64, false>* object;
 765     // The local symbol index in the object.
 766     unsigned int r_sym;
 767   };
 768
 769   // The GOT section.
 770   Output_data_got<64, false>* got_;
 771   // The PLT section.
 772   Output_data_plt_x86_64* plt_;
 773   // The GOT PLT section.
 774   Output_data_space* got_plt_;
 775   // The GOT section for IRELATIVE relocations.
 776   Output_data_space* got_irelative_;
 777   // The GOT section for TLSDESC relocations.
 778   Output_data_got<64, false>* got_tlsdesc_;
 779   // The _GLOBAL_OFFSET_TABLE_ symbol.
 780   Symbol* global_offset_table_;
 781   // The dynamic reloc section.
 782   Reloc_section* rela_dyn_;
 783   // The section to use for IRELATIVE relocs.
 784   Reloc_section* rela_irelative_;
 785   // Relocs saved to avoid a COPY reloc.
 786   Copy_relocs<elfcpp::SHT_RELA, 64, false> copy_relocs_;
 787   // Space for variables copied with a COPY reloc.
 788   Output_data_space* dynbss_;
 789   // Offset of the GOT entry for the TLS module index.
 790   unsigned int got_mod_index_offset_;
 791   // We handle R_X86_64_TLSDESC against a local symbol as a target
 792   // specific relocation.  Here we store the object and local symbol
 793   // index for the relocation.
 794   std::vector<Tlsdesc_info> tlsdesc_reloc_info_;
 795   // True if the _TLS_MODULE_BASE_ symbol has been defined.
 796   bool tls_base_symbol_defined_;
 797 };
 798
 799 const Target::Target_info Target_x86_64::x86_64_info =
 800 {
 801   64,                   // size
 802   false,                // is_big_endian
 803   elfcpp::EM_X86_64,    // machine_code
 804   false,                // has_make_symbol
 805   false,                // has_resolve
 806   true,                 // has_code_fill
 807   true,                 // is_default_stack_executable
 808   true,                 // can_icf_inline_merge_sections
 809   '\0',                 // wrap_char
 810   "/lib/ld64.so.1",     // program interpreter
 811   0x400000,             // default_text_segment_address
 812   0x1000,               // abi_pagesize (overridable by -z max-page-size)
 813   0x1000,               // common_pagesize (overridable by -z common-page-size)
 814   elfcpp::SHN_UNDEF,    // small_common_shndx
 815   elfcpp::SHN_X86_64_LCOMMON,   // large_common_shndx
 816   0,                    // small_common_section_flags
 817   elfcpp::SHF_X86_64_LARGE,     // large_common_section_flags
 818   NULL,                 // attributes_section
 819   NULL                  // attributes_vendor
 820 };
 821
 822 // This is called when a new output section is created.  This is where
 823 // we handle the SHF_X86_64_LARGE.
 824
 825 void
 826 Target_x86_64::do_new_output_section(Output_section* os) const
 827 {
 828   if ((os->flags() & elfcpp::SHF_X86_64_LARGE) != 0)
 829     os->set_is_large_section();
 830 }
 831
 832 // Get the GOT section, creating it if necessary.
 833
 834 Output_data_got<64, false>*
 835 Target_x86_64::got_section(Symbol_table* symtab, Layout* layout)
 836 {
 837   if (this->got_ == NULL)
 838     {
 839       gold_assert(symtab != NULL && layout != NULL);
 840
 841       // When using -z now, we can treat .got.plt as a relro section.
 842       // Without -z now, it is modified after program startup by lazy
 843       // PLT relocations.
 844       bool is_got_plt_relro = parameters->options().now();
 845       Output_section_order got_order = (is_got_plt_relro
 846                                         ? ORDER_RELRO
 847                                         : ORDER_RELRO_LAST);
 848       Output_section_order got_plt_order = (is_got_plt_relro
 849                                             ? ORDER_RELRO
 850                                             : ORDER_NON_RELRO_FIRST);
 851
 852       this->got_ = new Output_data_got<64, false>();
 853
 854       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
 855                                       (elfcpp::SHF_ALLOC
 856                                        | elfcpp::SHF_WRITE),
 857                                       this->got_, got_order, true);
 858
 859       this->got_plt_ = new Output_data_space(8, "** GOT PLT");
 860       layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
 861                                       (elfcpp::SHF_ALLOC
 862                                        | elfcpp::SHF_WRITE),
 863                                       this->got_plt_, got_plt_order,
 864                                       is_got_plt_relro);
 865
 866       // The first three entries are reserved.
 867       this->got_plt_->set_current_data_size(3 * 8);
 868
 869       if (!is_got_plt_relro)
 870         {
 871           // Those bytes can go into the relro segment.
 872           layout->increase_relro(3 * 8);
 873         }
 874
 875       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
 876       this->global_offset_table_ =
 877         symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
 878                                       Symbol_table::PREDEFINED,
 879                                       this->got_plt_,
 880                                       0, 0, elfcpp::STT_OBJECT,
 881                                       elfcpp::STB_LOCAL,
 882                                       elfcpp::STV_HIDDEN, 0,
 883                                       false, false);
 884
 885       // If there are any IRELATIVE relocations, they get GOT entries
 886       // in .got.plt after the jump slot entries.
 887       this->got_irelative_ = new Output_data_space(8, "** GOT IRELATIVE PLT");
 888       layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
 889                                       (elfcpp::SHF_ALLOC
 890                                        | elfcpp::SHF_WRITE),
 891                                       this->got_irelative_,
 892                                       got_plt_order, is_got_plt_relro);
 893
 894       // If there are any TLSDESC relocations, they get GOT entries in
 895       // .got.plt after the jump slot and IRELATIVE entries.
 896       this->got_tlsdesc_ = new Output_data_got<64, false>();
 897       layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
 898                                       (elfcpp::SHF_ALLOC
 899                                        | elfcpp::SHF_WRITE),
 900                                       this->got_tlsdesc_,
 901                                       got_plt_order, is_got_plt_relro);
 902     }
 903
 904   return this->got_;
 905 }
 906
 907 // Get the dynamic reloc section, creating it if necessary.
 908
 909 Target_x86_64::Reloc_section*
 910 Target_x86_64::rela_dyn_section(Layout* layout)
 911 {
 912   if (this->rela_dyn_ == NULL)
 913     {
 914       gold_assert(layout != NULL);
 915       this->rela_dyn_ = new Reloc_section(parameters->options().combreloc());
 916       layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
 917                                       elfcpp::SHF_ALLOC, this->rela_dyn_,
 918                                       ORDER_DYNAMIC_RELOCS, false);
 919     }
 920   return this->rela_dyn_;
 921 }
 922
 923 // Get the section to use for IRELATIVE relocs, creating it if
 924 // necessary.  These go in .rela.dyn, but only after all other dynamic
 925 // relocations.  They need to follow the other dynamic relocations so
 926 // that they can refer to global variables initialized by those
 927 // relocs.
 928
 929 Target_x86_64::Reloc_section*
 930 Target_x86_64::rela_irelative_section(Layout* layout)
 931 {
 932   if (this->rela_irelative_ == NULL)
 933     {
 934       // Make sure we have already created the dynamic reloc section.
 935       this->rela_dyn_section(layout);
 936       this->rela_irelative_ = new Reloc_section(false);
 937       layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
 938                                       elfcpp::SHF_ALLOC, this->rela_irelative_,
 939                                       ORDER_DYNAMIC_RELOCS, false);
 940       gold_assert(this->rela_dyn_->output_section()
 941                   == this->rela_irelative_->output_section());
 942     }
 943   return this->rela_irelative_;
 944 }
 945
 946 // Initialize the PLT section.
 947
 948 void
 949 Output_data_plt_x86_64::init(Layout* layout)
 950 {
 951   this->rel_ = new Reloc_section(false);
 952   layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
 953                                   elfcpp::SHF_ALLOC, this->rel_,
 954                                   ORDER_DYNAMIC_PLT_RELOCS, false);
 955
 956   // Add unwind information if requested.
 957   if (parameters->options().ld_generated_unwind_info())
 958     layout->add_eh_frame_for_plt(this, plt_eh_frame_cie, plt_eh_frame_cie_size,
 959                                  plt_eh_frame_fde, plt_eh_frame_fde_size);
 960 }
 961
 962 void
 963 Output_data_plt_x86_64::do_adjust_output_section(Output_section* os)
 964 {
 965   os->set_entsize(plt_entry_size);
 966 }
 967
 968 // Add an entry to the PLT.
 969
 970 void
 971 Output_data_plt_x86_64::add_entry(Symbol_table* symtab, Layout* layout,
 972                                   Symbol* gsym)
 973 {
 974   gold_assert(!gsym->has_plt_offset());
 975
 976   unsigned int plt_index;
 977   off_t plt_offset;
 978   section_offset_type got_offset;
 979
 980   unsigned int* pcount;
 981   unsigned int offset;
 982   unsigned int reserved;
 983   Output_data_space* got;
 984   if (gsym->type() == elfcpp::STT_GNU_IFUNC
 985       && gsym->can_use_relative_reloc(false))
 986     {
 987       pcount = &this->irelative_count_;
 988       offset = 0;
 989       reserved = 0;
 990       got = this->got_irelative_;
 991     }
 992   else
 993     {
 994       pcount = &this->count_;
 995       offset = 1;
 996       reserved = 3;
 997       got = this->got_plt_;
 998     }
 999
1000   if (!this->is_data_size_valid())
1001     {
1002       // Note that when setting the PLT offset for a non-IRELATIVE
1003       // entry we skip the initial reserved PLT entry.
1004       plt_index = *pcount + offset;
1005       plt_offset = plt_index * plt_entry_size;
1006
1007       ++*pcount;
1008
1009       got_offset = (plt_index - offset + reserved) * 8;
1010       gold_assert(got_offset == got->current_data_size());
1011
1012       // Every PLT entry needs a GOT entry which points back to the PLT
1013       // entry (this will be changed by the dynamic linker, normally
1014       // lazily when the function is called).
1015       got->set_current_data_size(got_offset + 8);
1016     }
1017   else
1018     {
1019       // FIXME: This is probably not correct for IRELATIVE relocs.
1020
1021       // For incremental updates, find an available slot.
1022       plt_offset = this->free_list_.allocate(plt_entry_size, plt_entry_size, 0);
1023       if (plt_offset == -1)
1024         gold_fallback(_("out of patch space (PLT);"
1025                         " relink with --incremental-full"));
1026
1027       // The GOT and PLT entries have a 1-1 correspondance, so the GOT offset
1028       // can be calculated from the PLT index, adjusting for the three
1029       // reserved entries at the beginning of the GOT.
1030       plt_index = plt_offset / plt_entry_size - 1;
1031       got_offset = (plt_index - offset + reserved) * 8;
1032     }
1033
1034   gsym->set_plt_offset(plt_offset);
1035
1036   // Every PLT entry needs a reloc.
1037   this->add_relocation(symtab, layout, gsym, got_offset);
1038
1039   // Note that we don't need to save the symbol.  The contents of the
1040   // PLT are independent of which symbols are used.  The symbols only
1041   // appear in the relocations.
1042 }
1043
1044 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.  Return
1045 // the PLT offset.
1046
1047 unsigned int
1048 Output_data_plt_x86_64::add_local_ifunc_entry(
1049     Symbol_table* symtab,
1050     Layout* layout,
1051     Sized_relobj_file<64, false>* relobj,
1052     unsigned int local_sym_index)
1053 {
1054   unsigned int plt_offset = this->irelative_count_ * plt_entry_size;
1055   ++this->irelative_count_;
1056
1057   section_offset_type got_offset = this->got_irelative_->current_data_size();
1058
1059   // Every PLT entry needs a GOT entry which points back to the PLT
1060   // entry.
1061   this->got_irelative_->set_current_data_size(got_offset + 8);
1062
1063   // Every PLT entry needs a reloc.
1064   Reloc_section* rela = this->rela_irelative(symtab, layout);
1065   rela->add_symbolless_local_addend(relobj, local_sym_index,
1066                                     elfcpp::R_X86_64_IRELATIVE,
1067                                     this->got_irelative_, got_offset, 0);
1068
1069   return plt_offset;
1070 }
1071
1072 // Add the relocation for a PLT entry.
1073
1074 void
1075 Output_data_plt_x86_64::add_relocation(Symbol_table* symtab, Layout* layout,
1076                                        Symbol* gsym, unsigned int got_offset)
1077 {
1078   if (gsym->type() == elfcpp::STT_GNU_IFUNC
1079       && gsym->can_use_relative_reloc(false))
1080     {
1081       Reloc_section* rela = this->rela_irelative(symtab, layout);
1082       rela->add_symbolless_global_addend(gsym, elfcpp::R_X86_64_IRELATIVE,
1083                                          this->got_irelative_, got_offset, 0);
1084     }
1085   else
1086     {
1087       gsym->set_needs_dynsym_entry();
1088       this->rel_->add_global(gsym, elfcpp::R_X86_64_JUMP_SLOT, this->got_plt_,
1089                              got_offset, 0);
1090     }
1091 }
1092
1093 // Return where the TLSDESC relocations should go, creating it if
1094 // necessary.  These follow the JUMP_SLOT relocations.
1095
1096 Output_data_plt_x86_64::Reloc_section*
1097 Output_data_plt_x86_64::rela_tlsdesc(Layout* layout)
1098 {
1099   if (this->tlsdesc_rel_ == NULL)
1100     {
1101       this->tlsdesc_rel_ = new Reloc_section(false);
1102       layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
1103                                       elfcpp::SHF_ALLOC, this->tlsdesc_rel_,
1104                                       ORDER_DYNAMIC_PLT_RELOCS, false);
1105       gold_assert(this->tlsdesc_rel_->output_section()
1106                   == this->rel_->output_section());
1107     }
1108   return this->tlsdesc_rel_;
1109 }
1110
1111 // Return where the IRELATIVE relocations should go in the PLT.  These
1112 // follow the JUMP_SLOT and the TLSDESC relocations.
1113
1114 Output_data_plt_x86_64::Reloc_section*
1115 Output_data_plt_x86_64::rela_irelative(Symbol_table* symtab, Layout* layout)
1116 {
1117   if (this->irelative_rel_ == NULL)
1118     {
1119       // Make sure we have a place for the TLSDESC relocations, in
1120       // case we see any later on.
1121       this->rela_tlsdesc(layout);
1122       this->irelative_rel_ = new Reloc_section(false);
1123       layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
1124                                       elfcpp::SHF_ALLOC, this->irelative_rel_,
1125                                       ORDER_DYNAMIC_PLT_RELOCS, false);
1126       gold_assert(this->irelative_rel_->output_section()
1127                   == this->rel_->output_section());
1128
1129       if (parameters->doing_static_link())
1130         {
1131           // A statically linked executable will only have a .rela.plt
1132           // section to hold R_X86_64_IRELATIVE relocs for
1133           // STT_GNU_IFUNC symbols.  The library will use these
1134           // symbols to locate the IRELATIVE relocs at program startup
1135           // time.
1136           symtab->define_in_output_data("__rela_iplt_start", NULL,
1137                                         Symbol_table::PREDEFINED,
1138                                         this->irelative_rel_, 0, 0,
1139                                         elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1140                                         elfcpp::STV_HIDDEN, 0, false, true);
1141           symtab->define_in_output_data("__rela_iplt_end", NULL,
1142                                         Symbol_table::PREDEFINED,
1143                                         this->irelative_rel_, 0, 0,
1144                                         elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1145                                         elfcpp::STV_HIDDEN, 0, true, true);
1146         }
1147     }
1148   return this->irelative_rel_;
1149 }
1150
1151 // Return the PLT address to use for a global symbol.
1152
1153 uint64_t
1154 Output_data_plt_x86_64::address_for_global(const Symbol* gsym)
1155 {
1156   uint64_t offset = 0;
1157   if (gsym->type() == elfcpp::STT_GNU_IFUNC
1158       && gsym->can_use_relative_reloc(false))
1159     offset = (this->count_ + 1) * plt_entry_size;
1160   return this->address() + offset;
1161 }
1162
1163 // Return the PLT address to use for a local symbol.  These are always
1164 // IRELATIVE relocs.
1165
1166 uint64_t
1167 Output_data_plt_x86_64::address_for_local(const Relobj*, unsigned int)
1168 {
1169   return this->address() + (this->count_ + 1) * plt_entry_size;
1170 }
1171
1172 // Set the final size.
1173 void
1174 Output_data_plt_x86_64::set_final_data_size()
1175 {
1176   unsigned int count = this->count_ + this->irelative_count_;
1177   if (this->has_tlsdesc_entry())
1178     ++count;
1179   this->set_data_size((count + 1) * plt_entry_size);
1180 }
1181
1182 // The first entry in the PLT for an executable.
1183
1184 const unsigned char Output_data_plt_x86_64::first_plt_entry[plt_entry_size] =
1185 {
1186   // From AMD64 ABI Draft 0.98, page 76
1187   0xff, 0x35,   // pushq contents of memory address
1188   0, 0, 0, 0,   // replaced with address of .got + 8
1189   0xff, 0x25,   // jmp indirect
1190   0, 0, 0, 0,   // replaced with address of .got + 16
1191   0x90, 0x90, 0x90, 0x90   // noop (x4)
1192 };
1193
1194 // Subsequent entries in the PLT for an executable.
1195
1196 const unsigned char Output_data_plt_x86_64::plt_entry[plt_entry_size] =
1197 {
1198   // From AMD64 ABI Draft 0.98, page 76
1199   0xff, 0x25,   // jmpq indirect
1200   0, 0, 0, 0,   // replaced with address of symbol in .got
1201   0x68,         // pushq immediate
1202   0, 0, 0, 0,   // replaced with offset into relocation table
1203   0xe9,         // jmpq relative
1204   0, 0, 0, 0    // replaced with offset to start of .plt
1205 };
1206
1207 // The reserved TLSDESC entry in the PLT for an executable.
1208
1209 const unsigned char Output_data_plt_x86_64::tlsdesc_plt_entry[plt_entry_size] =
1210 {
1211   // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
1212   // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
1213   0xff, 0x35,   // pushq x(%rip)
1214   0, 0, 0, 0,   // replaced with address of linkmap GOT entry (at PLTGOT + 8)
1215   0xff, 0x25,   // jmpq *y(%rip)
1216   0, 0, 0, 0,   // replaced with offset of reserved TLSDESC_GOT entry
1217   0x0f, 0x1f,   // nop
1218   0x40, 0
1219 };
1220
1221 // The .eh_frame unwind information for the PLT.
1222
1223 const unsigned char
1224 Output_data_plt_x86_64::plt_eh_frame_cie[plt_eh_frame_cie_size] =
1225 {
1226   1,                            // CIE version.
1227   'z',                          // Augmentation: augmentation size included.
1228   'R',                          // Augmentation: FDE encoding included.
1229   '\0',                         // End of augmentation string.
1230   1,                            // Code alignment factor.
1231   0x78,                         // Data alignment factor.
1232   16,                           // Return address column.
1233   1,                            // Augmentation size.
1234   (elfcpp::DW_EH_PE_pcrel       // FDE encoding.
1235    | elfcpp::DW_EH_PE_sdata4),
1236   elfcpp::DW_CFA_def_cfa, 7, 8, // DW_CFA_def_cfa: r7 (rsp) ofs 8.
1237   elfcpp::DW_CFA_offset + 16, 1,// DW_CFA_offset: r16 (rip) at cfa-8.
1238   elfcpp::DW_CFA_nop,           // Align to 16 bytes.
1239   elfcpp::DW_CFA_nop
1240 };
1241
1242 const unsigned char
1243 Output_data_plt_x86_64::plt_eh_frame_fde[plt_eh_frame_fde_size] =
1244 {
1245   0, 0, 0, 0,                           // Replaced with offset to .plt.
1246   0, 0, 0, 0,                           // Replaced with size of .plt.
1247   0,                                    // Augmentation size.
1248   elfcpp::DW_CFA_def_cfa_offset, 16,    // DW_CFA_def_cfa_offset: 16.
1249   elfcpp::DW_CFA_advance_loc + 6,       // Advance 6 to __PLT__ + 6.
1250   elfcpp::DW_CFA_def_cfa_offset, 24,    // DW_CFA_def_cfa_offset: 24.
1251   elfcpp::DW_CFA_advance_loc + 10,      // Advance 10 to __PLT__ + 16.
1252   elfcpp::DW_CFA_def_cfa_expression,    // DW_CFA_def_cfa_expression.
1253   11,                                   // Block length.
1254   elfcpp::DW_OP_breg7, 8,               // Push %rsp + 8.
1255   elfcpp::DW_OP_breg16, 0,              // Push %rip.
1256   elfcpp::DW_OP_lit15,                  // Push 0xf.
1257   elfcpp::DW_OP_and,                    // & (%rip & 0xf).
1258   elfcpp::DW_OP_lit11,                  // Push 0xb.
1259   elfcpp::DW_OP_ge,                     // >= ((%rip & 0xf) >= 0xb)
1260   elfcpp::DW_OP_lit3,                   // Push 3.
1261   elfcpp::DW_OP_shl,                    // << (((%rip & 0xf) >= 0xb) << 3)
1262   elfcpp::DW_OP_plus,                   // + ((((%rip&0xf)>=0xb)<<3)+%rsp+8
1263   elfcpp::DW_CFA_nop,                   // Align to 32 bytes.
1264   elfcpp::DW_CFA_nop,
1265   elfcpp::DW_CFA_nop,
1266   elfcpp::DW_CFA_nop
1267 };
1268
1269 // Write out the PLT.  This uses the hand-coded instructions above,
1270 // and adjusts them as needed.  This is specified by the AMD64 ABI.
1271
1272 void
1273 Output_data_plt_x86_64::do_write(Output_file* of)
1274 {
1275   const off_t offset = this->offset();
1276   const section_size_type oview_size =
1277     convert_to_section_size_type(this->data_size());
1278   unsigned char* const oview = of->get_output_view(offset, oview_size);
1279
1280   const off_t got_file_offset = this->got_plt_->offset();
1281   gold_assert(parameters->incremental_update()
1282               || (got_file_offset + this->got_plt_->data_size()
1283                   == this->got_irelative_->offset()));
1284   const section_size_type got_size =
1285     convert_to_section_size_type(this->got_plt_->data_size()
1286                                  + this->got_irelative_->data_size());
1287   unsigned char* const got_view = of->get_output_view(got_file_offset,
1288                                                       got_size);
1289
1290   unsigned char* pov = oview;
1291
1292   // The base address of the .plt section.
1293   elfcpp::Elf_types<64>::Elf_Addr plt_address = this->address();
1294   // The base address of the .got section.
1295   elfcpp::Elf_types<64>::Elf_Addr got_base = this->got_->address();
1296   // The base address of the PLT portion of the .got section,
1297   // which is where the GOT pointer will point, and where the
1298   // three reserved GOT entries are located.
1299   elfcpp::Elf_types<64>::Elf_Addr got_address = this->got_plt_->address();
1300
1301   memcpy(pov, first_plt_entry, plt_entry_size);
1302   // We do a jmp relative to the PC at the end of this instruction.
1303   elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1304                                               (got_address + 8
1305                                                - (plt_address + 6)));
1306   elfcpp::Swap<32, false>::writeval(pov + 8,
1307                                     (got_address + 16
1308                                      - (plt_address + 12)));
1309   pov += plt_entry_size;
1310
1311   unsigned char* got_pov = got_view;
1312
1313   // The first entry in the GOT is the address of the .dynamic section
1314   // aka the PT_DYNAMIC segment.  The next two entries are reserved.
1315   // We saved space for them when we created the section in
1316   // Target_x86_64::got_section.
1317   Output_section* dynamic = this->layout_->dynamic_section();
1318   uint32_t dynamic_addr = dynamic == NULL ? 0 : dynamic->address();
1319   elfcpp::Swap<64, false>::writeval(got_pov, dynamic_addr);
1320   got_pov += 8;
1321   memset(got_pov, 0, 16);
1322   got_pov += 16;
1323
1324   unsigned int plt_offset = plt_entry_size;
1325   unsigned int got_offset = 24;
1326   const unsigned int count = this->count_ + this->irelative_count_;
1327   for (unsigned int plt_index = 0;
1328        plt_index < count;
1329        ++plt_index,
1330          pov += plt_entry_size,
1331          got_pov += 8,
1332          plt_offset += plt_entry_size,
1333          got_offset += 8)
1334     {
1335       // Set and adjust the PLT entry itself.
1336       memcpy(pov, plt_entry, plt_entry_size);
1337       elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1338                                                   (got_address + got_offset
1339                                                    - (plt_address + plt_offset
1340                                                       + 6)));
1341
1342       elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_index);
1343       elfcpp::Swap<32, false>::writeval(pov + 12,
1344                                         - (plt_offset + plt_entry_size));
1345
1346       // Set the entry in the GOT.
1347       elfcpp::Swap<64, false>::writeval(got_pov, plt_address + plt_offset + 6);
1348     }
1349
1350   if (this->has_tlsdesc_entry())
1351     {
1352       // Set and adjust the reserved TLSDESC PLT entry.
1353       unsigned int tlsdesc_got_offset = this->get_tlsdesc_got_offset();
1354       memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
1355       elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1356                                                   (got_address + 8
1357                                                    - (plt_address + plt_offset
1358                                                       + 6)));
1359       elfcpp::Swap_unaligned<32, false>::writeval(pov + 8,
1360                                                   (got_base
1361                                                    + tlsdesc_got_offset
1362                                                    - (plt_address + plt_offset
1363                                                       + 12)));
1364       pov += plt_entry_size;
1365     }
1366
1367   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
1368   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
1369
1370   of->write_output_view(offset, oview_size, oview);
1371   of->write_output_view(got_file_offset, got_size, got_view);
1372 }
1373
1374 // Create the PLT section.
1375
1376 void
1377 Target_x86_64::make_plt_section(Symbol_table* symtab, Layout* layout)
1378 {
1379   if (this->plt_ == NULL)
1380     {
1381       // Create the GOT sections first.
1382       this->got_section(symtab, layout);
1383
1384       this->plt_ = new Output_data_plt_x86_64(layout, this->got_,
1385                                               this->got_plt_,
1386                                               this->got_irelative_);
1387       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
1388                                       (elfcpp::SHF_ALLOC
1389                                        | elfcpp::SHF_EXECINSTR),
1390                                       this->plt_, ORDER_PLT, false);
1391
1392       // Make the sh_info field of .rela.plt point to .plt.
1393       Output_section* rela_plt_os = this->plt_->rela_plt()->output_section();
1394       rela_plt_os->set_info_section(this->plt_->output_section());
1395     }
1396 }
1397
1398 // Return the section for TLSDESC relocations.
1399
1400 Target_x86_64::Reloc_section*
1401 Target_x86_64::rela_tlsdesc_section(Layout* layout) const
1402 {
1403   return this->plt_section()->rela_tlsdesc(layout);
1404 }
1405
1406 // Create a PLT entry for a global symbol.
1407
1408 void
1409 Target_x86_64::make_plt_entry(Symbol_table* symtab, Layout* layout,
1410                               Symbol* gsym)
1411 {
1412   if (gsym->has_plt_offset())
1413     return;
1414
1415   if (this->plt_ == NULL)
1416     this->make_plt_section(symtab, layout);
1417
1418   this->plt_->add_entry(symtab, layout, gsym);
1419 }
1420
1421 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1422
1423 void
1424 Target_x86_64::make_local_ifunc_plt_entry(Symbol_table* symtab, Layout* layout,
1425                                           Sized_relobj_file<64, false>* relobj,
1426                                           unsigned int local_sym_index)
1427 {
1428   if (relobj->local_has_plt_offset(local_sym_index))
1429     return;
1430   if (this->plt_ == NULL)
1431     this->make_plt_section(symtab, layout);
1432   unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout,
1433                                                               relobj,
1434                                                               local_sym_index);
1435   relobj->set_local_plt_offset(local_sym_index, plt_offset);
1436 }
1437
1438 // Return the number of entries in the PLT.
1439
1440 unsigned int
1441 Target_x86_64::plt_entry_count() const
1442 {
1443   if (this->plt_ == NULL)
1444     return 0;
1445   return this->plt_->entry_count();
1446 }
1447
1448 // Return the offset of the first non-reserved PLT entry.
1449
1450 unsigned int
1451 Target_x86_64::first_plt_entry_offset() const
1452 {
1453   return Output_data_plt_x86_64::first_plt_entry_offset();
1454 }
1455
1456 // Return the size of each PLT entry.
1457
1458 unsigned int
1459 Target_x86_64::plt_entry_size() const
1460 {
1461   return Output_data_plt_x86_64::get_plt_entry_size();
1462 }
1463
1464 // Create the GOT and PLT sections for an incremental update.
1465
1466 Output_data_got<64, false>*
1467 Target_x86_64::init_got_plt_for_update(Symbol_table* symtab,
1468                                        Layout* layout,
1469                                        unsigned int got_count,
1470                                        unsigned int plt_count)
1471 {
1472   gold_assert(this->got_ == NULL);
1473
1474   this->got_ = new Output_data_got<64, false>(got_count * 8);
1475   layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
1476                                   (elfcpp::SHF_ALLOC
1477                                    | elfcpp::SHF_WRITE),
1478                                   this->got_, ORDER_RELRO_LAST,
1479                                   true);
1480
1481   // Add the three reserved entries.
1482   this->got_plt_ = new Output_data_space((plt_count + 3) * 8, 8, "** GOT PLT");
1483   layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1484                                   (elfcpp::SHF_ALLOC
1485                                    | elfcpp::SHF_WRITE),
1486                                   this->got_plt_, ORDER_NON_RELRO_FIRST,
1487                                   false);
1488
1489   // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
1490   this->global_offset_table_ =
1491     symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
1492                                   Symbol_table::PREDEFINED,
1493                                   this->got_plt_,
1494                                   0, 0, elfcpp::STT_OBJECT,
1495                                   elfcpp::STB_LOCAL,
1496                                   elfcpp::STV_HIDDEN, 0,
1497                                   false, false);
1498
1499   // If there are any TLSDESC relocations, they get GOT entries in
1500   // .got.plt after the jump slot entries.
1501   // FIXME: Get the count for TLSDESC entries.
1502   this->got_tlsdesc_ = new Output_data_got<64, false>(0);
1503   layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1504                                   elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
1505                                   this->got_tlsdesc_,
1506                                   ORDER_NON_RELRO_FIRST, false);
1507
1508   // If there are any IRELATIVE relocations, they get GOT entries in
1509   // .got.plt after the jump slot and TLSDESC entries.
1510   this->got_irelative_ = new Output_data_space(0, 8, "** GOT IRELATIVE PLT");
1511   layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1512                                   elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
1513                                   this->got_irelative_,
1514                                   ORDER_NON_RELRO_FIRST, false);
1515
1516   // Create the PLT section.
1517   this->plt_ = new Output_data_plt_x86_64(layout, this->got_, this->got_plt_,
1518                                           this->got_irelative_, plt_count);
1519   layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
1520                                   elfcpp::SHF_ALLOC | elfcpp::SHF_EXECINSTR,
1521                                   this->plt_, ORDER_PLT, false);
1522
1523   // Make the sh_info field of .rela.plt point to .plt.
1524   Output_section* rela_plt_os = this->plt_->rela_plt()->output_section();
1525   rela_plt_os->set_info_section(this->plt_->output_section());
1526
1527   // Create the rela_dyn section.
1528   this->rela_dyn_section(layout);
1529
1530   return this->got_;
1531 }
1532
1533 // Reserve a GOT entry for a local symbol, and regenerate any
1534 // necessary dynamic relocations.
1535
1536 void
1537 Target_x86_64::reserve_local_got_entry(
1538     unsigned int got_index,
1539     Sized_relobj<64, false>* obj,
1540     unsigned int r_sym,
1541     unsigned int got_type)
1542 {
1543   unsigned int got_offset = got_index * 8;
1544   Reloc_section* rela_dyn = this->rela_dyn_section(NULL);
1545
1546   this->got_->reserve_local(got_index, obj, r_sym, got_type);
1547   switch (got_type)
1548     {
1549     case GOT_TYPE_STANDARD:
1550       if (parameters->options().output_is_position_independent())
1551         rela_dyn->add_local_relative(obj, r_sym, elfcpp::R_X86_64_RELATIVE,
1552                                      this->got_, got_offset, 0);
1553       break;
1554     case GOT_TYPE_TLS_OFFSET:
1555       rela_dyn->add_local(obj, r_sym, elfcpp::R_X86_64_TPOFF64,
1556                           this->got_, got_offset, 0);
1557       break;
1558     case GOT_TYPE_TLS_PAIR:
1559       this->got_->reserve_slot(got_index + 1);
1560       rela_dyn->add_local(obj, r_sym, elfcpp::R_X86_64_DTPMOD64,
1561                           this->got_, got_offset, 0);
1562       break;
1563     case GOT_TYPE_TLS_DESC:
1564       gold_fatal(_("TLS_DESC not yet supported for incremental linking"));
1565       // this->got_->reserve_slot(got_index + 1);
1566       // rela_dyn->add_target_specific(elfcpp::R_X86_64_TLSDESC, arg,
1567       //                               this->got_, got_offset, 0);
1568       break;
1569     default:
1570       gold_unreachable();
1571     }
1572 }
1573
1574 // Reserve a GOT entry for a global symbol, and regenerate any
1575 // necessary dynamic relocations.
1576
1577 void
1578 Target_x86_64::reserve_global_got_entry(unsigned int got_index, Symbol* gsym,
1579                                         unsigned int got_type)
1580 {
1581   unsigned int got_offset = got_index * 8;
1582   Reloc_section* rela_dyn = this->rela_dyn_section(NULL);
1583
1584   this->got_->reserve_global(got_index, gsym, got_type);
1585   switch (got_type)
1586     {
1587     case GOT_TYPE_STANDARD:
1588       if (!gsym->final_value_is_known())
1589         {
1590           if (gsym->is_from_dynobj()
1591               || gsym->is_undefined()
1592               || gsym->is_preemptible()
1593               || gsym->type() == elfcpp::STT_GNU_IFUNC)
1594             rela_dyn->add_global(gsym, elfcpp::R_X86_64_GLOB_DAT,
1595                                  this->got_, got_offset, 0);
1596           else
1597             rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_RELATIVE,
1598                                           this->got_, got_offset, 0);
1599         }
1600       break;
1601     case GOT_TYPE_TLS_OFFSET:
1602       rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_TPOFF64,
1603                                     this->got_, got_offset, 0);
1604       break;
1605     case GOT_TYPE_TLS_PAIR:
1606       this->got_->reserve_slot(got_index + 1);
1607       rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_DTPMOD64,
1608                                     this->got_, got_offset, 0);
1609       rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_DTPOFF64,
1610                                     this->got_, got_offset + 8, 0);
1611       break;
1612     case GOT_TYPE_TLS_DESC:
1613       this->got_->reserve_slot(got_index + 1);
1614       rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_TLSDESC,
1615                                     this->got_, got_offset, 0);
1616       break;
1617     default:
1618       gold_unreachable();
1619     }
1620 }
1621
1622 // Register an existing PLT entry for a global symbol.
1623
1624 void
1625 Target_x86_64::register_global_plt_entry(Symbol_table* symtab,
1626                                          Layout* layout,
1627                                          unsigned int plt_index,
1628                                          Symbol* gsym)
1629 {
1630   gold_assert(this->plt_ != NULL);
1631   gold_assert(!gsym->has_plt_offset());
1632
1633   this->plt_->reserve_slot(plt_index);
1634
1635   gsym->set_plt_offset((plt_index + 1) * this->plt_entry_size());
1636
1637   unsigned int got_offset = (plt_index + 3) * 8;
1638   this->plt_->add_relocation(symtab, layout, gsym, got_offset);
1639 }
1640
1641 // Force a COPY relocation for a given symbol.
1642
1643 void
1644 Target_x86_64::emit_copy_reloc(
1645     Symbol_table* symtab, Symbol* sym, Output_section* os, off_t offset)
1646 {
1647   this->copy_relocs_.emit_copy_reloc(symtab,
1648                                      symtab->get_sized_symbol<64>(sym),
1649                                      os,
1650                                      offset,
1651                                      this->rela_dyn_section(NULL));
1652 }
1653
1654 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1655
1656 void
1657 Target_x86_64::define_tls_base_symbol(Symbol_table* symtab, Layout* layout)
1658 {
1659   if (this->tls_base_symbol_defined_)
1660     return;
1661
1662   Output_segment* tls_segment = layout->tls_segment();
1663   if (tls_segment != NULL)
1664     {
1665       bool is_exec = parameters->options().output_is_executable();
1666       symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
1667                                        Symbol_table::PREDEFINED,
1668                                        tls_segment, 0, 0,
1669                                        elfcpp::STT_TLS,
1670                                        elfcpp::STB_LOCAL,
1671                                        elfcpp::STV_HIDDEN, 0,
1672                                        (is_exec
1673                                         ? Symbol::SEGMENT_END
1674                                         : Symbol::SEGMENT_START),
1675                                        true);
1676     }
1677   this->tls_base_symbol_defined_ = true;
1678 }
1679
1680 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
1681
1682 void
1683 Target_x86_64::reserve_tlsdesc_entries(Symbol_table* symtab,
1684                                              Layout* layout)
1685 {
1686   if (this->plt_ == NULL)
1687     this->make_plt_section(symtab, layout);
1688
1689   if (!this->plt_->has_tlsdesc_entry())
1690     {
1691       // Allocate the TLSDESC_GOT entry.
1692       Output_data_got<64, false>* got = this->got_section(symtab, layout);
1693       unsigned int got_offset = got->add_constant(0);
1694
1695       // Allocate the TLSDESC_PLT entry.
1696       this->plt_->reserve_tlsdesc_entry(got_offset);
1697     }
1698 }
1699
1700 // Create a GOT entry for the TLS module index.
1701
1702 unsigned int
1703 Target_x86_64::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
1704                                    Sized_relobj_file<64, false>* object)
1705 {
1706   if (this->got_mod_index_offset_ == -1U)
1707     {
1708       gold_assert(symtab != NULL && layout != NULL && object != NULL);
1709       Reloc_section* rela_dyn = this->rela_dyn_section(layout);
1710       Output_data_got<64, false>* got = this->got_section(symtab, layout);
1711       unsigned int got_offset = got->add_constant(0);
1712       rela_dyn->add_local(object, 0, elfcpp::R_X86_64_DTPMOD64, got,
1713                           got_offset, 0);
1714       got->add_constant(0);
1715       this->got_mod_index_offset_ = got_offset;
1716     }
1717   return this->got_mod_index_offset_;
1718 }
1719
1720 // Optimize the TLS relocation type based on what we know about the
1721 // symbol.  IS_FINAL is true if the final address of this symbol is
1722 // known at link time.
1723
1724 tls::Tls_optimization
1725 Target_x86_64::optimize_tls_reloc(bool is_final, int r_type)
1726 {
1727   // If we are generating a shared library, then we can't do anything
1728   // in the linker.
1729   if (parameters->options().shared())
1730     return tls::TLSOPT_NONE;
1731
1732   switch (r_type)
1733     {
1734     case elfcpp::R_X86_64_TLSGD:
1735     case elfcpp::R_X86_64_GOTPC32_TLSDESC:
1736     case elfcpp::R_X86_64_TLSDESC_CALL:
1737       // These are General-Dynamic which permits fully general TLS
1738       // access.  Since we know that we are generating an executable,
1739       // we can convert this to Initial-Exec.  If we also know that
1740       // this is a local symbol, we can further switch to Local-Exec.
1741       if (is_final)
1742         return tls::TLSOPT_TO_LE;
1743       return tls::TLSOPT_TO_IE;
1744
1745     case elfcpp::R_X86_64_TLSLD:
1746       // This is Local-Dynamic, which refers to a local symbol in the
1747       // dynamic TLS block.  Since we know that we generating an
1748       // executable, we can switch to Local-Exec.
1749       return tls::TLSOPT_TO_LE;
1750
1751     case elfcpp::R_X86_64_DTPOFF32:
1752     case elfcpp::R_X86_64_DTPOFF64:
1753       // Another Local-Dynamic reloc.
1754       return tls::TLSOPT_TO_LE;
1755
1756     case elfcpp::R_X86_64_GOTTPOFF:
1757       // These are Initial-Exec relocs which get the thread offset
1758       // from the GOT.  If we know that we are linking against the
1759       // local symbol, we can switch to Local-Exec, which links the
1760       // thread offset into the instruction.
1761       if (is_final)
1762         return tls::TLSOPT_TO_LE;
1763       return tls::TLSOPT_NONE;
1764
1765     case elfcpp::R_X86_64_TPOFF32:
1766       // When we already have Local-Exec, there is nothing further we
1767       // can do.
1768       return tls::TLSOPT_NONE;
1769
1770     default:
1771       gold_unreachable();
1772     }
1773 }
1774
1775 // Get the Reference_flags for a particular relocation.
1776
1777 int
1778 Target_x86_64::Scan::get_reference_flags(unsigned int r_type)
1779 {
1780   switch (r_type)
1781     {
1782     case elfcpp::R_X86_64_NONE:
1783     case elfcpp::R_X86_64_GNU_VTINHERIT:
1784     case elfcpp::R_X86_64_GNU_VTENTRY:
1785     case elfcpp::R_X86_64_GOTPC32:
1786     case elfcpp::R_X86_64_GOTPC64:
1787       // No symbol reference.
1788       return 0;
1789
1790     case elfcpp::R_X86_64_64:
1791     case elfcpp::R_X86_64_32:
1792     case elfcpp::R_X86_64_32S:
1793     case elfcpp::R_X86_64_16:
1794     case elfcpp::R_X86_64_8:
1795       return Symbol::ABSOLUTE_REF;
1796
1797     case elfcpp::R_X86_64_PC64:
1798     case elfcpp::R_X86_64_PC32:
1799     case elfcpp::R_X86_64_PC16:
1800     case elfcpp::R_X86_64_PC8:
1801     case elfcpp::R_X86_64_GOTOFF64:
1802       return Symbol::RELATIVE_REF;
1803
1804     case elfcpp::R_X86_64_PLT32:
1805     case elfcpp::R_X86_64_PLTOFF64:
1806       return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
1807
1808     case elfcpp::R_X86_64_GOT64:
1809     case elfcpp::R_X86_64_GOT32:
1810     case elfcpp::R_X86_64_GOTPCREL64:
1811     case elfcpp::R_X86_64_GOTPCREL:
1812     case elfcpp::R_X86_64_GOTPLT64:
1813       // Absolute in GOT.
1814       return Symbol::ABSOLUTE_REF;
1815
1816     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
1817     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
1818     case elfcpp::R_X86_64_TLSDESC_CALL:
1819     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
1820     case elfcpp::R_X86_64_DTPOFF32:
1821     case elfcpp::R_X86_64_DTPOFF64:
1822     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
1823     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
1824       return Symbol::TLS_REF;
1825
1826     case elfcpp::R_X86_64_COPY:
1827     case elfcpp::R_X86_64_GLOB_DAT:
1828     case elfcpp::R_X86_64_JUMP_SLOT:
1829     case elfcpp::R_X86_64_RELATIVE:
1830     case elfcpp::R_X86_64_IRELATIVE:
1831     case elfcpp::R_X86_64_TPOFF64:
1832     case elfcpp::R_X86_64_DTPMOD64:
1833     case elfcpp::R_X86_64_TLSDESC:
1834     case elfcpp::R_X86_64_SIZE32:
1835     case elfcpp::R_X86_64_SIZE64:
1836     default:
1837       // Not expected.  We will give an error later.
1838       return 0;
1839     }
1840 }
1841
1842 // Report an unsupported relocation against a local symbol.
1843
1844 void
1845 Target_x86_64::Scan::unsupported_reloc_local(
1846      Sized_relobj_file<64, false>* object,
1847      unsigned int r_type)
1848 {
1849   gold_error(_("%s: unsupported reloc %u against local symbol"),
1850              object->name().c_str(), r_type);
1851 }
1852
1853 // We are about to emit a dynamic relocation of type R_TYPE.  If the
1854 // dynamic linker does not support it, issue an error.  The GNU linker
1855 // only issues a non-PIC error for an allocated read-only section.
1856 // Here we know the section is allocated, but we don't know that it is
1857 // read-only.  But we check for all the relocation types which the
1858 // glibc dynamic linker supports, so it seems appropriate to issue an
1859 // error even if the section is not read-only.  If GSYM is not NULL,
1860 // it is the symbol the relocation is against; if it is NULL, the
1861 // relocation is against a local symbol.
1862
1863 void
1864 Target_x86_64::Scan::check_non_pic(Relobj* object, unsigned int r_type,
1865                                    Symbol* gsym)
1866 {
1867   switch (r_type)
1868     {
1869       // These are the relocation types supported by glibc for x86_64
1870       // which should always work.
1871     case elfcpp::R_X86_64_RELATIVE:
1872     case elfcpp::R_X86_64_IRELATIVE:
1873     case elfcpp::R_X86_64_GLOB_DAT:
1874     case elfcpp::R_X86_64_JUMP_SLOT:
1875     case elfcpp::R_X86_64_DTPMOD64:
1876     case elfcpp::R_X86_64_DTPOFF64:
1877     case elfcpp::R_X86_64_TPOFF64:
1878     case elfcpp::R_X86_64_64:
1879     case elfcpp::R_X86_64_COPY:
1880       return;
1881
1882       // glibc supports these reloc types, but they can overflow.
1883     case elfcpp::R_X86_64_PC32:
1884       // A PC relative reference is OK against a local symbol or if
1885       // the symbol is defined locally.
1886       if (gsym == NULL
1887           || (!gsym->is_from_dynobj()
1888               && !gsym->is_undefined()
1889               && !gsym->is_preemptible()))
1890         return;
1891       /* Fall through.  */
1892     case elfcpp::R_X86_64_32:
1893       if (this->issued_non_pic_error_)
1894         return;
1895       gold_assert(parameters->options().output_is_position_independent());
1896       if (gsym == NULL)
1897         object->error(_("requires dynamic R_X86_64_32 reloc which may "
1898                         "overflow at runtime; recompile with -fPIC"));
1899       else
1900         object->error(_("requires dynamic %s reloc against '%s' which may "
1901                         "overflow at runtime; recompile with -fPIC"),
1902                       (r_type == elfcpp::R_X86_64_32
1903                        ? "R_X86_64_32"
1904                        : "R_X86_64_PC32"),
1905                       gsym->name());
1906       this->issued_non_pic_error_ = true;
1907       return;
1908
1909     default:
1910       // This prevents us from issuing more than one error per reloc
1911       // section.  But we can still wind up issuing more than one
1912       // error per object file.
1913       if (this->issued_non_pic_error_)
1914         return;
1915       gold_assert(parameters->options().output_is_position_independent());
1916       object->error(_("requires unsupported dynamic reloc %u; "
1917                       "recompile with -fPIC"),
1918                     r_type);
1919       this->issued_non_pic_error_ = true;
1920       return;
1921
1922     case elfcpp::R_X86_64_NONE:
1923       gold_unreachable();
1924     }
1925 }
1926
1927 // Return whether we need to make a PLT entry for a relocation of the
1928 // given type against a STT_GNU_IFUNC symbol.
1929
1930 bool
1931 Target_x86_64::Scan::reloc_needs_plt_for_ifunc(
1932      Sized_relobj_file<64, false>* object,
1933      unsigned int r_type)
1934 {
1935   int flags = Scan::get_reference_flags(r_type);
1936   if (flags & Symbol::TLS_REF)
1937     gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
1938                object->name().c_str(), r_type);
1939   return flags != 0;
1940 }
1941
1942 // Scan a relocation for a local symbol.
1943
1944 inline void
1945 Target_x86_64::Scan::local(Symbol_table* symtab,
1946                            Layout* layout,
1947                            Target_x86_64* target,
1948                            Sized_relobj_file<64, false>* object,
1949                            unsigned int data_shndx,
1950                            Output_section* output_section,
1951                            const elfcpp::Rela<64, false>& reloc,
1952                            unsigned int r_type,
1953                            const elfcpp::Sym<64, false>& lsym)
1954 {
1955   // A local STT_GNU_IFUNC symbol may require a PLT entry.
1956   if (lsym.get_st_type() == elfcpp::STT_GNU_IFUNC
1957       && this->reloc_needs_plt_for_ifunc(object, r_type))
1958     {
1959       unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
1960       target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
1961     }
1962
1963   switch (r_type)
1964     {
1965     case elfcpp::R_X86_64_NONE:
1966     case elfcpp::R_X86_64_GNU_VTINHERIT:
1967     case elfcpp::R_X86_64_GNU_VTENTRY:
1968       break;
1969
1970     case elfcpp::R_X86_64_64:
1971       // If building a shared library (or a position-independent
1972       // executable), we need to create a dynamic relocation for this
1973       // location.  The relocation applied at link time will apply the
1974       // link-time value, so we flag the location with an
1975       // R_X86_64_RELATIVE relocation so the dynamic loader can
1976       // relocate it easily.
1977       if (parameters->options().output_is_position_independent())
1978         {
1979           unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
1980           Reloc_section* rela_dyn = target->rela_dyn_section(layout);
1981           rela_dyn->add_local_relative(object, r_sym,
1982                                        elfcpp::R_X86_64_RELATIVE,
1983                                        output_section, data_shndx,
1984                                        reloc.get_r_offset(),
1985                                        reloc.get_r_addend());
1986         }
1987       break;
1988
1989     case elfcpp::R_X86_64_32:
1990     case elfcpp::R_X86_64_32S:
1991     case elfcpp::R_X86_64_16:
1992     case elfcpp::R_X86_64_8:
1993       // If building a shared library (or a position-independent
1994       // executable), we need to create a dynamic relocation for this
1995       // location.  We can't use an R_X86_64_RELATIVE relocation
1996       // because that is always a 64-bit relocation.
1997       if (parameters->options().output_is_position_independent())
1998         {
1999           this->check_non_pic(object, r_type, NULL);
2000
2001           Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2002           unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
2003           if (lsym.get_st_type() != elfcpp::STT_SECTION)
2004             rela_dyn->add_local(object, r_sym, r_type, output_section,
2005                                 data_shndx, reloc.get_r_offset(),
2006                                 reloc.get_r_addend());
2007           else
2008             {
2009               gold_assert(lsym.get_st_value() == 0);
2010               unsigned int shndx = lsym.get_st_shndx();
2011               bool is_ordinary;
2012               shndx = object->adjust_sym_shndx(r_sym, shndx,
2013                                                &is_ordinary);
2014               if (!is_ordinary)
2015                 object->error(_("section symbol %u has bad shndx %u"),
2016                               r_sym, shndx);
2017               else
2018                 rela_dyn->add_local_section(object, shndx,
2019                                             r_type, output_section,
2020                                             data_shndx, reloc.get_r_offset(),
2021                                             reloc.get_r_addend());
2022             }
2023         }
2024       break;
2025
2026     case elfcpp::R_X86_64_PC64:
2027     case elfcpp::R_X86_64_PC32:
2028     case elfcpp::R_X86_64_PC16:
2029     case elfcpp::R_X86_64_PC8:
2030       break;
2031
2032     case elfcpp::R_X86_64_PLT32:
2033       // Since we know this is a local symbol, we can handle this as a
2034       // PC32 reloc.
2035       break;
2036
2037     case elfcpp::R_X86_64_GOTPC32:
2038     case elfcpp::R_X86_64_GOTOFF64:
2039     case elfcpp::R_X86_64_GOTPC64:
2040     case elfcpp::R_X86_64_PLTOFF64:
2041       // We need a GOT section.
2042       target->got_section(symtab, layout);
2043       // For PLTOFF64, we'd normally want a PLT section, but since we
2044       // know this is a local symbol, no PLT is needed.
2045       break;
2046
2047     case elfcpp::R_X86_64_GOT64:
2048     case elfcpp::R_X86_64_GOT32:
2049     case elfcpp::R_X86_64_GOTPCREL64:
2050     case elfcpp::R_X86_64_GOTPCREL:
2051     case elfcpp::R_X86_64_GOTPLT64:
2052       {
2053         // The symbol requires a GOT entry.
2054         Output_data_got<64, false>* got = target->got_section(symtab, layout);
2055         unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
2056
2057         // For a STT_GNU_IFUNC symbol we want the PLT offset.  That
2058         // lets function pointers compare correctly with shared
2059         // libraries.  Otherwise we would need an IRELATIVE reloc.
2060         bool is_new;
2061         if (lsym.get_st_type() == elfcpp::STT_GNU_IFUNC)
2062           is_new = got->add_local_plt(object, r_sym, GOT_TYPE_STANDARD);
2063         else
2064           is_new = got->add_local(object, r_sym, GOT_TYPE_STANDARD);
2065         if (is_new)
2066           {
2067             // If we are generating a shared object, we need to add a
2068             // dynamic relocation for this symbol's GOT entry.
2069             if (parameters->options().output_is_position_independent())
2070               {
2071                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2072                 // R_X86_64_RELATIVE assumes a 64-bit relocation.
2073                 if (r_type != elfcpp::R_X86_64_GOT32)
2074                   {
2075                     unsigned int got_offset =
2076                       object->local_got_offset(r_sym, GOT_TYPE_STANDARD);
2077                     rela_dyn->add_local_relative(object, r_sym,
2078                                                  elfcpp::R_X86_64_RELATIVE,
2079                                                  got, got_offset, 0);
2080                   }
2081                 else
2082                   {
2083                     this->check_non_pic(object, r_type, NULL);
2084
2085                     gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
2086                     rela_dyn->add_local(
2087                         object, r_sym, r_type, got,
2088                         object->local_got_offset(r_sym, GOT_TYPE_STANDARD), 0);
2089                   }
2090               }
2091           }
2092         // For GOTPLT64, we'd normally want a PLT section, but since
2093         // we know this is a local symbol, no PLT is needed.
2094       }
2095       break;
2096
2097     case elfcpp::R_X86_64_COPY:
2098     case elfcpp::R_X86_64_GLOB_DAT:
2099     case elfcpp::R_X86_64_JUMP_SLOT:
2100     case elfcpp::R_X86_64_RELATIVE:
2101     case elfcpp::R_X86_64_IRELATIVE:
2102       // These are outstanding tls relocs, which are unexpected when linking
2103     case elfcpp::R_X86_64_TPOFF64:
2104     case elfcpp::R_X86_64_DTPMOD64:
2105     case elfcpp::R_X86_64_TLSDESC:
2106       gold_error(_("%s: unexpected reloc %u in object file"),
2107                  object->name().c_str(), r_type);
2108       break;
2109
2110       // These are initial tls relocs, which are expected when linking
2111     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
2112     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
2113     case elfcpp::R_X86_64_TLSDESC_CALL:
2114     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
2115     case elfcpp::R_X86_64_DTPOFF32:
2116     case elfcpp::R_X86_64_DTPOFF64:
2117     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
2118     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
2119       {
2120         bool output_is_shared = parameters->options().shared();
2121         const tls::Tls_optimization optimized_type
2122             = Target_x86_64::optimize_tls_reloc(!output_is_shared, r_type);
2123         switch (r_type)
2124           {
2125           case elfcpp::R_X86_64_TLSGD:       // General-dynamic
2126             if (optimized_type == tls::TLSOPT_NONE)
2127               {
2128                 // Create a pair of GOT entries for the module index and
2129                 // dtv-relative offset.
2130                 Output_data_got<64, false>* got
2131                     = target->got_section(symtab, layout);
2132                 unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
2133                 unsigned int shndx = lsym.get_st_shndx();
2134                 bool is_ordinary;
2135                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
2136                 if (!is_ordinary)
2137                   object->error(_("local symbol %u has bad shndx %u"),
2138                               r_sym, shndx);
2139                 else
2140                   got->add_local_pair_with_rela(object, r_sym,
2141                                                 shndx,
2142                                                 GOT_TYPE_TLS_PAIR,
2143                                                 target->rela_dyn_section(layout),
2144                                                 elfcpp::R_X86_64_DTPMOD64, 0);
2145               }
2146             else if (optimized_type != tls::TLSOPT_TO_LE)
2147               unsupported_reloc_local(object, r_type);
2148             break;
2149
2150           case elfcpp::R_X86_64_GOTPC32_TLSDESC:
2151             target->define_tls_base_symbol(symtab, layout);
2152             if (optimized_type == tls::TLSOPT_NONE)
2153               {
2154                 // Create reserved PLT and GOT entries for the resolver.
2155                 target->reserve_tlsdesc_entries(symtab, layout);
2156
2157                 // Generate a double GOT entry with an
2158                 // R_X86_64_TLSDESC reloc.  The R_X86_64_TLSDESC reloc
2159                 // is resolved lazily, so the GOT entry needs to be in
2160                 // an area in .got.plt, not .got.  Call got_section to
2161                 // make sure the section has been created.
2162                 target->got_section(symtab, layout);
2163                 Output_data_got<64, false>* got = target->got_tlsdesc_section();
2164                 unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
2165                 if (!object->local_has_got_offset(r_sym, GOT_TYPE_TLS_DESC))
2166                   {
2167                     unsigned int got_offset = got->add_constant(0);
2168                     got->add_constant(0);
2169                     object->set_local_got_offset(r_sym, GOT_TYPE_TLS_DESC,
2170                                                  got_offset);
2171                     Reloc_section* rt = target->rela_tlsdesc_section(layout);
2172                     // We store the arguments we need in a vector, and
2173                     // use the index into the vector as the parameter
2174                     // to pass to the target specific routines.
2175                     uintptr_t intarg = target->add_tlsdesc_info(object, r_sym);
2176                     void* arg = reinterpret_cast<void*>(intarg);
2177                     rt->add_target_specific(elfcpp::R_X86_64_TLSDESC, arg,
2178                                             got, got_offset, 0);
2179                   }
2180               }
2181             else if (optimized_type != tls::TLSOPT_TO_LE)
2182               unsupported_reloc_local(object, r_type);
2183             break;
2184
2185           case elfcpp::R_X86_64_TLSDESC_CALL:
2186             break;
2187
2188           case elfcpp::R_X86_64_TLSLD:       // Local-dynamic
2189             if (optimized_type == tls::TLSOPT_NONE)
2190               {
2191                 // Create a GOT entry for the module index.
2192                 target->got_mod_index_entry(symtab, layout, object);
2193               }
2194             else if (optimized_type != tls::TLSOPT_TO_LE)
2195               unsupported_reloc_local(object, r_type);
2196             break;
2197
2198           case elfcpp::R_X86_64_DTPOFF32:
2199           case elfcpp::R_X86_64_DTPOFF64:
2200             break;
2201
2202           case elfcpp::R_X86_64_GOTTPOFF:    // Initial-exec
2203             layout->set_has_static_tls();
2204             if (optimized_type == tls::TLSOPT_NONE)
2205               {
2206                 // Create a GOT entry for the tp-relative offset.
2207                 Output_data_got<64, false>* got
2208                     = target->got_section(symtab, layout);
2209                 unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
2210                 got->add_local_with_rela(object, r_sym, GOT_TYPE_TLS_OFFSET,
2211                                          target->rela_dyn_section(layout),
2212                                          elfcpp::R_X86_64_TPOFF64);
2213               }
2214             else if (optimized_type != tls::TLSOPT_TO_LE)
2215               unsupported_reloc_local(object, r_type);
2216             break;
2217
2218           case elfcpp::R_X86_64_TPOFF32:     // Local-exec
2219             layout->set_has_static_tls();
2220             if (output_is_shared)
2221               unsupported_reloc_local(object, r_type);
2222             break;
2223
2224           default:
2225             gold_unreachable();
2226           }
2227       }
2228       break;
2229
2230     case elfcpp::R_X86_64_SIZE32:
2231     case elfcpp::R_X86_64_SIZE64:
2232     default:
2233       gold_error(_("%s: unsupported reloc %u against local symbol"),
2234                  object->name().c_str(), r_type);
2235       break;
2236     }
2237 }
2238
2239
2240 // Report an unsupported relocation against a global symbol.
2241
2242 void
2243 Target_x86_64::Scan::unsupported_reloc_global(
2244     Sized_relobj_file<64, false>* object,
2245     unsigned int r_type,
2246     Symbol* gsym)
2247 {
2248   gold_error(_("%s: unsupported reloc %u against global symbol %s"),
2249              object->name().c_str(), r_type, gsym->demangled_name().c_str());
2250 }
2251
2252 // Returns true if this relocation type could be that of a function pointer.
2253 inline bool
2254 Target_x86_64::Scan::possible_function_pointer_reloc(unsigned int r_type)
2255 {
2256   switch (r_type)
2257     {
2258     case elfcpp::R_X86_64_64:
2259     case elfcpp::R_X86_64_32:
2260     case elfcpp::R_X86_64_32S:
2261     case elfcpp::R_X86_64_16:
2262     case elfcpp::R_X86_64_8:
2263     case elfcpp::R_X86_64_GOT64:
2264     case elfcpp::R_X86_64_GOT32:
2265     case elfcpp::R_X86_64_GOTPCREL64:
2266     case elfcpp::R_X86_64_GOTPCREL:
2267     case elfcpp::R_X86_64_GOTPLT64:
2268       {
2269         return true;
2270       }
2271     }
2272   return false;
2273 }
2274
2275 // For safe ICF, scan a relocation for a local symbol to check if it
2276 // corresponds to a function pointer being taken.  In that case mark
2277 // the function whose pointer was taken as not foldable.
2278
2279 inline bool
2280 Target_x86_64::Scan::local_reloc_may_be_function_pointer(
2281   Symbol_table* ,
2282   Layout* ,
2283   Target_x86_64* ,
2284   Sized_relobj_file<64, false>* ,
2285   unsigned int ,
2286   Output_section* ,
2287   const elfcpp::Rela<64, false>& ,
2288   unsigned int r_type,
2289   const elfcpp::Sym<64, false>&)
2290 {
2291   // When building a shared library, do not fold any local symbols as it is
2292   // not possible to distinguish pointer taken versus a call by looking at
2293   // the relocation types.
2294   return (parameters->options().shared()
2295           || possible_function_pointer_reloc(r_type));
2296 }
2297
2298 // For safe ICF, scan a relocation for a global symbol to check if it
2299 // corresponds to a function pointer being taken.  In that case mark
2300 // the function whose pointer was taken as not foldable.
2301
2302 inline bool
2303 Target_x86_64::Scan::global_reloc_may_be_function_pointer(
2304   Symbol_table*,
2305   Layout* ,
2306   Target_x86_64* ,
2307   Sized_relobj_file<64, false>* ,
2308   unsigned int ,
2309   Output_section* ,
2310   const elfcpp::Rela<64, false>& ,
2311   unsigned int r_type,
2312   Symbol* gsym)
2313 {
2314   // When building a shared library, do not fold symbols whose visibility
2315   // is hidden, internal or protected.
2316   return ((parameters->options().shared()
2317            && (gsym->visibility() == elfcpp::STV_INTERNAL
2318                || gsym->visibility() == elfcpp::STV_PROTECTED
2319                || gsym->visibility() == elfcpp::STV_HIDDEN))
2320           || possible_function_pointer_reloc(r_type));
2321 }
2322
2323 // Scan a relocation for a global symbol.
2324
2325 inline void
2326 Target_x86_64::Scan::global(Symbol_table* symtab,
2327                             Layout* layout,
2328                             Target_x86_64* target,
2329                             Sized_relobj_file<64, false>* object,
2330                             unsigned int data_shndx,
2331                             Output_section* output_section,
2332                             const elfcpp::Rela<64, false>& reloc,
2333                             unsigned int r_type,
2334                             Symbol* gsym)
2335 {
2336   // A STT_GNU_IFUNC symbol may require a PLT entry.
2337   if (gsym->type() == elfcpp::STT_GNU_IFUNC
2338       && this->reloc_needs_plt_for_ifunc(object, r_type))
2339     target->make_plt_entry(symtab, layout, gsym);
2340
2341   switch (r_type)
2342     {
2343     case elfcpp::R_X86_64_NONE:
2344     case elfcpp::R_X86_64_GNU_VTINHERIT:
2345     case elfcpp::R_X86_64_GNU_VTENTRY:
2346       break;
2347
2348     case elfcpp::R_X86_64_64:
2349     case elfcpp::R_X86_64_32:
2350     case elfcpp::R_X86_64_32S:
2351     case elfcpp::R_X86_64_16:
2352     case elfcpp::R_X86_64_8:
2353       {
2354         // Make a PLT entry if necessary.
2355         if (gsym->needs_plt_entry())
2356           {
2357             target->make_plt_entry(symtab, layout, gsym);
2358             // Since this is not a PC-relative relocation, we may be
2359             // taking the address of a function. In that case we need to
2360             // set the entry in the dynamic symbol table to the address of
2361             // the PLT entry.
2362             if (gsym->is_from_dynobj() && !parameters->options().shared())
2363               gsym->set_needs_dynsym_value();
2364           }
2365         // Make a dynamic relocation if necessary.
2366         if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
2367           {
2368             if (gsym->may_need_copy_reloc())
2369               {
2370                 target->copy_reloc(symtab, layout, object,
2371                                    data_shndx, output_section, gsym, reloc);
2372               }
2373             else if (r_type == elfcpp::R_X86_64_64
2374                      && gsym->type() == elfcpp::STT_GNU_IFUNC
2375                      && gsym->can_use_relative_reloc(false)
2376                      && !gsym->is_from_dynobj()
2377                      && !gsym->is_undefined()
2378                      && !gsym->is_preemptible())
2379               {
2380                 // Use an IRELATIVE reloc for a locally defined
2381                 // STT_GNU_IFUNC symbol.  This makes a function
2382                 // address in a PIE executable match the address in a
2383                 // shared library that it links against.
2384                 Reloc_section* rela_dyn =
2385                   target->rela_irelative_section(layout);
2386                 unsigned int r_type = elfcpp::R_X86_64_IRELATIVE;
2387                 rela_dyn->add_symbolless_global_addend(gsym, r_type,
2388                                                        output_section, object,
2389                                                        data_shndx,
2390                                                        reloc.get_r_offset(),
2391                                                        reloc.get_r_addend());
2392               }
2393             else if (r_type == elfcpp::R_X86_64_64
2394                      && gsym->can_use_relative_reloc(false))
2395               {
2396                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2397                 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_RELATIVE,
2398                                               output_section, object,
2399                                               data_shndx,
2400                                               reloc.get_r_offset(),
2401                                               reloc.get_r_addend());
2402               }
2403             else
2404               {
2405                 this->check_non_pic(object, r_type, gsym);
2406                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2407                 rela_dyn->add_global(gsym, r_type, output_section, object,
2408                                      data_shndx, reloc.get_r_offset(),
2409                                      reloc.get_r_addend());
2410               }
2411           }
2412       }
2413       break;
2414
2415     case elfcpp::R_X86_64_PC64:
2416     case elfcpp::R_X86_64_PC32:
2417     case elfcpp::R_X86_64_PC16:
2418     case elfcpp::R_X86_64_PC8:
2419       {
2420         // Make a PLT entry if necessary.
2421         if (gsym->needs_plt_entry())
2422           target->make_plt_entry(symtab, layout, gsym);
2423         // Make a dynamic relocation if necessary.
2424         if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
2425           {
2426             if (gsym->may_need_copy_reloc())
2427               {
2428                 target->copy_reloc(symtab, layout, object,
2429                                    data_shndx, output_section, gsym, reloc);
2430               }
2431             else
2432               {
2433                 this->check_non_pic(object, r_type, gsym);
2434                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2435                 rela_dyn->add_global(gsym, r_type, output_section, object,
2436                                      data_shndx, reloc.get_r_offset(),
2437                                      reloc.get_r_addend());
2438               }
2439           }
2440       }
2441       break;
2442
2443     case elfcpp::R_X86_64_GOT64:
2444     case elfcpp::R_X86_64_GOT32:
2445     case elfcpp::R_X86_64_GOTPCREL64:
2446     case elfcpp::R_X86_64_GOTPCREL:
2447     case elfcpp::R_X86_64_GOTPLT64:
2448       {
2449         // The symbol requires a GOT entry.
2450         Output_data_got<64, false>* got = target->got_section(symtab, layout);
2451         if (gsym->final_value_is_known())
2452           {
2453             // For a STT_GNU_IFUNC symbol we want the PLT address.
2454             if (gsym->type() == elfcpp::STT_GNU_IFUNC)
2455               got->add_global_plt(gsym, GOT_TYPE_STANDARD);
2456             else
2457               got->add_global(gsym, GOT_TYPE_STANDARD);
2458           }
2459         else
2460           {
2461             // If this symbol is not fully resolved, we need to add a
2462             // dynamic relocation for it.
2463             Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2464
2465             // Use a GLOB_DAT rather than a RELATIVE reloc if:
2466             //
2467             // 1) The symbol may be defined in some other module.
2468             //
2469             // 2) We are building a shared library and this is a
2470             // protected symbol; using GLOB_DAT means that the dynamic
2471             // linker can use the address of the PLT in the main
2472             // executable when appropriate so that function address
2473             // comparisons work.
2474             //
2475             // 3) This is a STT_GNU_IFUNC symbol in position dependent
2476             // code, again so that function address comparisons work.
2477             if (gsym->is_from_dynobj()
2478                 || gsym->is_undefined()
2479                 || gsym->is_preemptible()
2480                 || (gsym->visibility() == elfcpp::STV_PROTECTED
2481                     && parameters->options().shared())
2482                 || (gsym->type() == elfcpp::STT_GNU_IFUNC
2483                     && parameters->options().output_is_position_independent()))
2484               got->add_global_with_rela(gsym, GOT_TYPE_STANDARD, rela_dyn,
2485                                         elfcpp::R_X86_64_GLOB_DAT);
2486             else
2487               {
2488                 // For a STT_GNU_IFUNC symbol we want to write the PLT
2489                 // offset into the GOT, so that function pointer
2490                 // comparisons work correctly.
2491                 bool is_new;
2492                 if (gsym->type() != elfcpp::STT_GNU_IFUNC)
2493                   is_new = got->add_global(gsym, GOT_TYPE_STANDARD);
2494                 else
2495                   {
2496                     is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD);
2497                     // Tell the dynamic linker to use the PLT address
2498                     // when resolving relocations.
2499                     if (gsym->is_from_dynobj()
2500                         && !parameters->options().shared())
2501                       gsym->set_needs_dynsym_value();
2502                   }
2503                 if (is_new)
2504                   {
2505                     unsigned int got_off = gsym->got_offset(GOT_TYPE_STANDARD);
2506                     rela_dyn->add_global_relative(gsym,
2507                                                   elfcpp::R_X86_64_RELATIVE,
2508                                                   got, got_off, 0);
2509                   }
2510               }
2511           }
2512         // For GOTPLT64, we also need a PLT entry (but only if the
2513         // symbol is not fully resolved).
2514         if (r_type == elfcpp::R_X86_64_GOTPLT64
2515             && !gsym->final_value_is_known())
2516           target->make_plt_entry(symtab, layout, gsym);
2517       }
2518       break;
2519
2520     case elfcpp::R_X86_64_PLT32:
2521       // If the symbol is fully resolved, this is just a PC32 reloc.
2522       // Otherwise we need a PLT entry.
2523       if (gsym->final_value_is_known())
2524         break;
2525       // If building a shared library, we can also skip the PLT entry
2526       // if the symbol is defined in the output file and is protected
2527       // or hidden.
2528       if (gsym->is_defined()
2529           && !gsym->is_from_dynobj()
2530           && !gsym->is_preemptible())
2531         break;
2532       target->make_plt_entry(symtab, layout, gsym);
2533       break;
2534
2535     case elfcpp::R_X86_64_GOTPC32:
2536     case elfcpp::R_X86_64_GOTOFF64:
2537     case elfcpp::R_X86_64_GOTPC64:
2538     case elfcpp::R_X86_64_PLTOFF64:
2539       // We need a GOT section.
2540       target->got_section(symtab, layout);
2541       // For PLTOFF64, we also need a PLT entry (but only if the
2542       // symbol is not fully resolved).
2543       if (r_type == elfcpp::R_X86_64_PLTOFF64
2544           && !gsym->final_value_is_known())
2545         target->make_plt_entry(symtab, layout, gsym);
2546       break;
2547
2548     case elfcpp::R_X86_64_COPY:
2549     case elfcpp::R_X86_64_GLOB_DAT:
2550     case elfcpp::R_X86_64_JUMP_SLOT:
2551     case elfcpp::R_X86_64_RELATIVE:
2552     case elfcpp::R_X86_64_IRELATIVE:
2553       // These are outstanding tls relocs, which are unexpected when linking
2554     case elfcpp::R_X86_64_TPOFF64:
2555     case elfcpp::R_X86_64_DTPMOD64:
2556     case elfcpp::R_X86_64_TLSDESC:
2557       gold_error(_("%s: unexpected reloc %u in object file"),
2558                  object->name().c_str(), r_type);
2559       break;
2560
2561       // These are initial tls relocs, which are expected for global()
2562     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
2563     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
2564     case elfcpp::R_X86_64_TLSDESC_CALL:
2565     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
2566     case elfcpp::R_X86_64_DTPOFF32:
2567     case elfcpp::R_X86_64_DTPOFF64:
2568     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
2569     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
2570       {
2571         const bool is_final = gsym->final_value_is_known();
2572         const tls::Tls_optimization optimized_type
2573             = Target_x86_64::optimize_tls_reloc(is_final, r_type);
2574         switch (r_type)
2575           {
2576           case elfcpp::R_X86_64_TLSGD:       // General-dynamic
2577             if (optimized_type == tls::TLSOPT_NONE)
2578               {
2579                 // Create a pair of GOT entries for the module index and
2580                 // dtv-relative offset.
2581                 Output_data_got<64, false>* got
2582                     = target->got_section(symtab, layout);
2583                 got->add_global_pair_with_rela(gsym, GOT_TYPE_TLS_PAIR,
2584                                                target->rela_dyn_section(layout),
2585                                                elfcpp::R_X86_64_DTPMOD64,
2586                                                elfcpp::R_X86_64_DTPOFF64);
2587               }
2588             else if (optimized_type == tls::TLSOPT_TO_IE)
2589               {
2590                 // Create a GOT entry for the tp-relative offset.
2591                 Output_data_got<64, false>* got
2592                     = target->got_section(symtab, layout);
2593                 got->add_global_with_rela(gsym, GOT_TYPE_TLS_OFFSET,
2594                                           target->rela_dyn_section(layout),
2595                                           elfcpp::R_X86_64_TPOFF64);
2596               }
2597             else if (optimized_type != tls::TLSOPT_TO_LE)
2598               unsupported_reloc_global(object, r_type, gsym);
2599             break;
2600
2601           case elfcpp::R_X86_64_GOTPC32_TLSDESC:
2602             target->define_tls_base_symbol(symtab, layout);
2603             if (optimized_type == tls::TLSOPT_NONE)
2604               {
2605                 // Create reserved PLT and GOT entries for the resolver.
2606                 target->reserve_tlsdesc_entries(symtab, layout);
2607
2608                 // Create a double GOT entry with an R_X86_64_TLSDESC
2609                 // reloc.  The R_X86_64_TLSDESC reloc is resolved
2610                 // lazily, so the GOT entry needs to be in an area in
2611                 // .got.plt, not .got.  Call got_section to make sure
2612                 // the section has been created.
2613                 target->got_section(symtab, layout);
2614                 Output_data_got<64, false>* got = target->got_tlsdesc_section();
2615                 Reloc_section* rt = target->rela_tlsdesc_section(layout);
2616                 got->add_global_pair_with_rela(gsym, GOT_TYPE_TLS_DESC, rt,
2617                                                elfcpp::R_X86_64_TLSDESC, 0);
2618               }
2619             else if (optimized_type == tls::TLSOPT_TO_IE)
2620               {
2621                 // Create a GOT entry for the tp-relative offset.
2622                 Output_data_got<64, false>* got
2623                     = target->got_section(symtab, layout);
2624                 got->add_global_with_rela(gsym, GOT_TYPE_TLS_OFFSET,
2625                                           target->rela_dyn_section(layout),
2626                                           elfcpp::R_X86_64_TPOFF64);
2627               }
2628             else if (optimized_type != tls::TLSOPT_TO_LE)
2629               unsupported_reloc_global(object, r_type, gsym);
2630             break;
2631
2632           case elfcpp::R_X86_64_TLSDESC_CALL:
2633             break;
2634
2635           case elfcpp::R_X86_64_TLSLD:       // Local-dynamic
2636             if (optimized_type == tls::TLSOPT_NONE)
2637               {
2638                 // Create a GOT entry for the module index.
2639                 target->got_mod_index_entry(symtab, layout, object);
2640               }
2641             else if (optimized_type != tls::TLSOPT_TO_LE)
2642               unsupported_reloc_global(object, r_type, gsym);
2643             break;
2644
2645           case elfcpp::R_X86_64_DTPOFF32:
2646           case elfcpp::R_X86_64_DTPOFF64:
2647             break;
2648
2649           case elfcpp::R_X86_64_GOTTPOFF:    // Initial-exec
2650             layout->set_has_static_tls();
2651             if (optimized_type == tls::TLSOPT_NONE)
2652               {
2653                 // Create a GOT entry for the tp-relative offset.
2654                 Output_data_got<64, false>* got
2655                     = target->got_section(symtab, layout);
2656                 got->add_global_with_rela(gsym, GOT_TYPE_TLS_OFFSET,
2657                                           target->rela_dyn_section(layout),
2658                                           elfcpp::R_X86_64_TPOFF64);
2659               }
2660             else if (optimized_type != tls::TLSOPT_TO_LE)
2661               unsupported_reloc_global(object, r_type, gsym);
2662             break;
2663
2664           case elfcpp::R_X86_64_TPOFF32:     // Local-exec
2665             layout->set_has_static_tls();
2666             if (parameters->options().shared())
2667               unsupported_reloc_local(object, r_type);
2668             break;
2669
2670           default:
2671             gold_unreachable();
2672           }
2673       }
2674       break;
2675
2676     case elfcpp::R_X86_64_SIZE32:
2677     case elfcpp::R_X86_64_SIZE64:
2678     default:
2679       gold_error(_("%s: unsupported reloc %u against global symbol %s"),
2680                  object->name().c_str(), r_type,
2681                  gsym->demangled_name().c_str());
2682       break;
2683     }
2684 }
2685
2686 void
2687 Target_x86_64::gc_process_relocs(Symbol_table* symtab,
2688                                  Layout* layout,
2689                                  Sized_relobj_file<64, false>* object,
2690                                  unsigned int data_shndx,
2691                                  unsigned int sh_type,
2692                                  const unsigned char* prelocs,
2693                                  size_t reloc_count,
2694                                  Output_section* output_section,
2695                                  bool needs_special_offset_handling,
2696                                  size_t local_symbol_count,
2697                                  const unsigned char* plocal_symbols)
2698 {
2699
2700   if (sh_type == elfcpp::SHT_REL)
2701     {
2702       return;
2703     }
2704
2705    gold::gc_process_relocs<64, false, Target_x86_64, elfcpp::SHT_RELA,
2706                            Target_x86_64::Scan,
2707                            Target_x86_64::Relocatable_size_for_reloc>(
2708     symtab,
2709     layout,
2710     this,
2711     object,
2712     data_shndx,
2713     prelocs,
2714     reloc_count,
2715     output_section,
2716     needs_special_offset_handling,
2717     local_symbol_count,
2718     plocal_symbols);
2719
2720 }
2721 // Scan relocations for a section.
2722
2723 void
2724 Target_x86_64::scan_relocs(Symbol_table* symtab,
2725                            Layout* layout,
2726                            Sized_relobj_file<64, false>* object,
2727                            unsigned int data_shndx,
2728                            unsigned int sh_type,
2729                            const unsigned char* prelocs,
2730                            size_t reloc_count,
2731                            Output_section* output_section,
2732                            bool needs_special_offset_handling,
2733                            size_t local_symbol_count,
2734                            const unsigned char* plocal_symbols)
2735 {
2736   if (sh_type == elfcpp::SHT_REL)
2737     {
2738       gold_error(_("%s: unsupported REL reloc section"),
2739                  object->name().c_str());
2740       return;
2741     }
2742
2743   gold::scan_relocs<64, false, Target_x86_64, elfcpp::SHT_RELA,
2744       Target_x86_64::Scan>(
2745     symtab,
2746     layout,
2747     this,
2748     object,
2749     data_shndx,
2750     prelocs,
2751     reloc_count,
2752     output_section,
2753     needs_special_offset_handling,
2754     local_symbol_count,
2755     plocal_symbols);
2756 }
2757
2758 // Finalize the sections.
2759
2760 void
2761 Target_x86_64::do_finalize_sections(
2762     Layout* layout,
2763     const Input_objects*,
2764     Symbol_table* symtab)
2765 {
2766   const Reloc_section* rel_plt = (this->plt_ == NULL
2767                                   ? NULL
2768                                   : this->plt_->rela_plt());
2769   layout->add_target_dynamic_tags(false, this->got_plt_, rel_plt,
2770                                   this->rela_dyn_, true, false);
2771
2772   // Fill in some more dynamic tags.
2773   Output_data_dynamic* const odyn = layout->dynamic_data();
2774   if (odyn != NULL)
2775     {
2776       if (this->plt_ != NULL
2777           && this->plt_->output_section() != NULL
2778           && this->plt_->has_tlsdesc_entry())
2779         {
2780           unsigned int plt_offset = this->plt_->get_tlsdesc_plt_offset();
2781           unsigned int got_offset = this->plt_->get_tlsdesc_got_offset();
2782           this->got_->finalize_data_size();
2783           odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_PLT,
2784                                         this->plt_, plt_offset);
2785           odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_GOT,
2786                                         this->got_, got_offset);
2787         }
2788     }
2789
2790   // Emit any relocs we saved in an attempt to avoid generating COPY
2791   // relocs.
2792   if (this->copy_relocs_.any_saved_relocs())
2793     this->copy_relocs_.emit(this->rela_dyn_section(layout));
2794
2795   // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
2796   // the .got.plt section.
2797   Symbol* sym = this->global_offset_table_;
2798   if (sym != NULL)
2799     {
2800       uint64_t data_size = this->got_plt_->current_data_size();
2801       symtab->get_sized_symbol<64>(sym)->set_symsize(data_size);
2802     }
2803
2804   if (parameters->doing_static_link()
2805       && (this->plt_ == NULL || !this->plt_->has_irelative_section()))
2806     {
2807       // If linking statically, make sure that the __rela_iplt symbols
2808       // were defined if necessary, even if we didn't create a PLT.
2809       static const Define_symbol_in_segment syms[] =
2810         {
2811           {
2812             "__rela_iplt_start",        // name
2813             elfcpp::PT_LOAD,            // segment_type
2814             elfcpp::PF_W,               // segment_flags_set
2815             elfcpp::PF(0),              // segment_flags_clear
2816             0,                          // value
2817             0,                          // size
2818             elfcpp::STT_NOTYPE,         // type
2819             elfcpp::STB_GLOBAL,         // binding
2820             elfcpp::STV_HIDDEN,         // visibility
2821             0,                          // nonvis
2822             Symbol::SEGMENT_START,      // offset_from_base
2823             true                        // only_if_ref
2824           },
2825           {
2826             "__rela_iplt_end",          // name
2827             elfcpp::PT_LOAD,            // segment_type
2828             elfcpp::PF_W,               // segment_flags_set
2829             elfcpp::PF(0),              // segment_flags_clear
2830             0,                          // value
2831             0,                          // size
2832             elfcpp::STT_NOTYPE,         // type
2833             elfcpp::STB_GLOBAL,         // binding
2834             elfcpp::STV_HIDDEN,         // visibility
2835             0,                          // nonvis
2836             Symbol::SEGMENT_START,      // offset_from_base
2837             true                        // only_if_ref
2838           }
2839         };
2840
2841       symtab->define_symbols(layout, 2, syms,
2842                              layout->script_options()->saw_sections_clause());
2843     }
2844 }
2845
2846 // Perform a relocation.
2847
2848 inline bool
2849 Target_x86_64::Relocate::relocate(const Relocate_info<64, false>* relinfo,
2850                                   Target_x86_64* target,
2851                                   Output_section*,
2852                                   size_t relnum,
2853                                   const elfcpp::Rela<64, false>& rela,
2854                                   unsigned int r_type,
2855                                   const Sized_symbol<64>* gsym,
2856                                   const Symbol_value<64>* psymval,
2857                                   unsigned char* view,
2858                                   elfcpp::Elf_types<64>::Elf_Addr address,
2859                                   section_size_type view_size)
2860 {
2861   if (this->skip_call_tls_get_addr_)
2862     {
2863       if ((r_type != elfcpp::R_X86_64_PLT32
2864            && r_type != elfcpp::R_X86_64_PC32)
2865           || gsym == NULL
2866           || strcmp(gsym->name(), "__tls_get_addr") != 0)
2867         {
2868           gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
2869                                  _("missing expected TLS relocation"));
2870         }
2871       else
2872         {
2873           this->skip_call_tls_get_addr_ = false;
2874           return false;
2875         }
2876     }
2877
2878   const Sized_relobj_file<64, false>* object = relinfo->object;
2879
2880   // Pick the value to use for symbols defined in the PLT.
2881   Symbol_value<64> symval;
2882   if (gsym != NULL
2883       && gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
2884     {
2885       symval.set_output_value(target->plt_address_for_global(gsym)
2886                               + gsym->plt_offset());
2887       psymval = &symval;
2888     }
2889   else if (gsym == NULL && psymval->is_ifunc_symbol())
2890     {
2891       unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
2892       if (object->local_has_plt_offset(r_sym))
2893         {
2894           symval.set_output_value(target->plt_address_for_local(object, r_sym)
2895                                   + object->local_plt_offset(r_sym));
2896           psymval = &symval;
2897         }
2898     }
2899
2900   const elfcpp::Elf_Xword addend = rela.get_r_addend();
2901
2902   // Get the GOT offset if needed.
2903   // The GOT pointer points to the end of the GOT section.
2904   // We need to subtract the size of the GOT section to get
2905   // the actual offset to use in the relocation.
2906   bool have_got_offset = false;
2907   unsigned int got_offset = 0;
2908   switch (r_type)
2909     {
2910     case elfcpp::R_X86_64_GOT32:
2911     case elfcpp::R_X86_64_GOT64:
2912     case elfcpp::R_X86_64_GOTPLT64:
2913     case elfcpp::R_X86_64_GOTPCREL:
2914     case elfcpp::R_X86_64_GOTPCREL64:
2915       if (gsym != NULL)
2916         {
2917           gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
2918           got_offset = gsym->got_offset(GOT_TYPE_STANDARD) - target->got_size();
2919         }
2920       else
2921         {
2922           unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
2923           gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
2924           got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
2925                         - target->got_size());
2926         }
2927       have_got_offset = true;
2928       break;
2929
2930     default:
2931       break;
2932     }
2933
2934   switch (r_type)
2935     {
2936     case elfcpp::R_X86_64_NONE:
2937     case elfcpp::R_X86_64_GNU_VTINHERIT:
2938     case elfcpp::R_X86_64_GNU_VTENTRY:
2939       break;
2940
2941     case elfcpp::R_X86_64_64:
2942       Relocate_functions<64, false>::rela64(view, object, psymval, addend);
2943       break;
2944
2945     case elfcpp::R_X86_64_PC64:
2946       Relocate_functions<64, false>::pcrela64(view, object, psymval, addend,
2947                                               address);
2948       break;
2949
2950     case elfcpp::R_X86_64_32:
2951       // FIXME: we need to verify that value + addend fits into 32 bits:
2952       //    uint64_t x = value + addend;
2953       //    x == static_cast<uint64_t>(static_cast<uint32_t>(x))
2954       // Likewise for other <=32-bit relocations (but see R_X86_64_32S).
2955       Relocate_functions<64, false>::rela32(view, object, psymval, addend);
2956       break;
2957
2958     case elfcpp::R_X86_64_32S:
2959       // FIXME: we need to verify that value + addend fits into 32 bits:
2960       //    int64_t x = value + addend;   // note this quantity is signed!
2961       //    x == static_cast<int64_t>(static_cast<int32_t>(x))
2962       Relocate_functions<64, false>::rela32(view, object, psymval, addend);
2963       break;
2964
2965     case elfcpp::R_X86_64_PC32:
2966       Relocate_functions<64, false>::pcrela32(view, object, psymval, addend,
2967                                               address);
2968       break;
2969
2970     case elfcpp::R_X86_64_16:
2971       Relocate_functions<64, false>::rela16(view, object, psymval, addend);
2972       break;
2973
2974     case elfcpp::R_X86_64_PC16:
2975       Relocate_functions<64, false>::pcrela16(view, object, psymval, addend,
2976                                               address);
2977       break;
2978
2979     case elfcpp::R_X86_64_8:
2980       Relocate_functions<64, false>::rela8(view, object, psymval, addend);
2981       break;
2982
2983     case elfcpp::R_X86_64_PC8:
2984       Relocate_functions<64, false>::pcrela8(view, object, psymval, addend,
2985                                              address);
2986       break;
2987
2988     case elfcpp::R_X86_64_PLT32:
2989       gold_assert(gsym == NULL
2990                   || gsym->has_plt_offset()
2991                   || gsym->final_value_is_known()
2992                   || (gsym->is_defined()
2993                       && !gsym->is_from_dynobj()
2994                       && !gsym->is_preemptible()));
2995       // Note: while this code looks the same as for R_X86_64_PC32, it
2996       // behaves differently because psymval was set to point to
2997       // the PLT entry, rather than the symbol, in Scan::global().
2998       Relocate_functions<64, false>::pcrela32(view, object, psymval, addend,
2999                                               address);
3000       break;
3001
3002     case elfcpp::R_X86_64_PLTOFF64:
3003       {
3004         gold_assert(gsym);
3005         gold_assert(gsym->has_plt_offset()
3006                     || gsym->final_value_is_known());
3007         elfcpp::Elf_types<64>::Elf_Addr got_address;
3008         got_address = target->got_section(NULL, NULL)->address();
3009         Relocate_functions<64, false>::rela64(view, object, psymval,
3010                                               addend - got_address);
3011       }
3012
3013     case elfcpp::R_X86_64_GOT32:
3014       gold_assert(have_got_offset);
3015       Relocate_functions<64, false>::rela32(view, got_offset, addend);
3016       break;
3017
3018     case elfcpp::R_X86_64_GOTPC32:
3019       {
3020         gold_assert(gsym);
3021         elfcpp::Elf_types<64>::Elf_Addr value;
3022         value = target->got_plt_section()->address();
3023         Relocate_functions<64, false>::pcrela32(view, value, addend, address);
3024       }
3025       break;
3026
3027     case elfcpp::R_X86_64_GOT64:
3028       // The ABI doc says "Like GOT64, but indicates a PLT entry is needed."
3029       // Since we always add a PLT entry, this is equivalent.
3030     case elfcpp::R_X86_64_GOTPLT64:
3031       gold_assert(have_got_offset);
3032       Relocate_functions<64, false>::rela64(view, got_offset, addend);
3033       break;
3034
3035     case elfcpp::R_X86_64_GOTPC64:
3036       {
3037         gold_assert(gsym);
3038         elfcpp::Elf_types<64>::Elf_Addr value;
3039         value = target->got_plt_section()->address();
3040         Relocate_functions<64, false>::pcrela64(view, value, addend, address);
3041       }
3042       break;
3043
3044     case elfcpp::R_X86_64_GOTOFF64:
3045       {
3046         elfcpp::Elf_types<64>::Elf_Addr value;
3047         value = (psymval->value(object, 0)
3048                  - target->got_plt_section()->address());
3049         Relocate_functions<64, false>::rela64(view, value, addend);
3050       }
3051       break;
3052
3053     case elfcpp::R_X86_64_GOTPCREL:
3054       {
3055         gold_assert(have_got_offset);
3056         elfcpp::Elf_types<64>::Elf_Addr value;
3057         value = target->got_plt_section()->address() + got_offset;
3058         Relocate_functions<64, false>::pcrela32(view, value, addend, address);
3059       }
3060       break;
3061
3062     case elfcpp::R_X86_64_GOTPCREL64:
3063       {
3064         gold_assert(have_got_offset);
3065         elfcpp::Elf_types<64>::Elf_Addr value;
3066         value = target->got_plt_section()->address() + got_offset;
3067         Relocate_functions<64, false>::pcrela64(view, value, addend, address);
3068       }
3069       break;
3070
3071     case elfcpp::R_X86_64_COPY:
3072     case elfcpp::R_X86_64_GLOB_DAT:
3073     case elfcpp::R_X86_64_JUMP_SLOT:
3074     case elfcpp::R_X86_64_RELATIVE:
3075     case elfcpp::R_X86_64_IRELATIVE:
3076       // These are outstanding tls relocs, which are unexpected when linking
3077     case elfcpp::R_X86_64_TPOFF64:
3078     case elfcpp::R_X86_64_DTPMOD64:
3079     case elfcpp::R_X86_64_TLSDESC:
3080       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3081                              _("unexpected reloc %u in object file"),
3082                              r_type);
3083       break;
3084
3085       // These are initial tls relocs, which are expected when linking
3086     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
3087     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
3088     case elfcpp::R_X86_64_TLSDESC_CALL:
3089     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
3090     case elfcpp::R_X86_64_DTPOFF32:
3091     case elfcpp::R_X86_64_DTPOFF64:
3092     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
3093     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
3094       this->relocate_tls(relinfo, target, relnum, rela, r_type, gsym, psymval,
3095                          view, address, view_size);
3096       break;
3097
3098     case elfcpp::R_X86_64_SIZE32:
3099     case elfcpp::R_X86_64_SIZE64:
3100     default:
3101       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3102                              _("unsupported reloc %u"),
3103                              r_type);
3104       break;
3105     }
3106
3107   return true;
3108 }
3109
3110 // Perform a TLS relocation.
3111
3112 inline void
3113 Target_x86_64::Relocate::relocate_tls(const Relocate_info<64, false>* relinfo,
3114                                       Target_x86_64* target,
3115                                       size_t relnum,
3116                                       const elfcpp::Rela<64, false>& rela,
3117                                       unsigned int r_type,
3118                                       const Sized_symbol<64>* gsym,
3119                                       const Symbol_value<64>* psymval,
3120                                       unsigned char* view,
3121                                       elfcpp::Elf_types<64>::Elf_Addr address,
3122                                       section_size_type view_size)
3123 {
3124   Output_segment* tls_segment = relinfo->layout->tls_segment();
3125
3126   const Sized_relobj_file<64, false>* object = relinfo->object;
3127   const elfcpp::Elf_Xword addend = rela.get_r_addend();
3128   elfcpp::Shdr<64, false> data_shdr(relinfo->data_shdr);
3129   bool is_executable = (data_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0;
3130
3131   elfcpp::Elf_types<64>::Elf_Addr value = psymval->value(relinfo->object, 0);
3132
3133   const bool is_final = (gsym == NULL
3134                          ? !parameters->options().shared()
3135                          : gsym->final_value_is_known());
3136   tls::Tls_optimization optimized_type
3137       = Target_x86_64::optimize_tls_reloc(is_final, r_type);
3138   switch (r_type)
3139     {
3140     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
3141       if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
3142         {
3143           // If this code sequence is used in a non-executable section,
3144           // we will not optimize the R_X86_64_DTPOFF32/64 relocation,
3145           // on the assumption that it's being used by itself in a debug
3146           // section.  Therefore, in the unlikely event that the code
3147           // sequence appears in a non-executable section, we simply
3148           // leave it unoptimized.
3149           optimized_type = tls::TLSOPT_NONE;
3150         }
3151       if (optimized_type == tls::TLSOPT_TO_LE)
3152         {
3153           if (tls_segment == NULL)
3154             {
3155               gold_assert(parameters->errors()->error_count() > 0
3156                           || issue_undefined_symbol_error(gsym));
3157               return;
3158             }
3159           this->tls_gd_to_le(relinfo, relnum, tls_segment,
3160                              rela, r_type, value, view,
3161                              view_size);
3162           break;
3163         }
3164       else
3165         {
3166           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
3167                                    ? GOT_TYPE_TLS_OFFSET
3168                                    : GOT_TYPE_TLS_PAIR);
3169           unsigned int got_offset;
3170           if (gsym != NULL)
3171             {
3172               gold_assert(gsym->has_got_offset(got_type));
3173               got_offset = gsym->got_offset(got_type) - target->got_size();
3174             }
3175           else
3176             {
3177               unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
3178               gold_assert(object->local_has_got_offset(r_sym, got_type));
3179               got_offset = (object->local_got_offset(r_sym, got_type)
3180                             - target->got_size());
3181             }
3182           if (optimized_type == tls::TLSOPT_TO_IE)
3183             {
3184               value = target->got_plt_section()->address() + got_offset;
3185               this->tls_gd_to_ie(relinfo, relnum, tls_segment, rela, r_type,
3186                                  value, view, address, view_size);
3187               break;
3188             }
3189           else if (optimized_type == tls::TLSOPT_NONE)
3190             {
3191               // Relocate the field with the offset of the pair of GOT
3192               // entries.
3193               value = target->got_plt_section()->address() + got_offset;
3194               Relocate_functions<64, false>::pcrela32(view, value, addend,
3195                                                       address);
3196               break;
3197             }
3198         }
3199       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3200                              _("unsupported reloc %u"), r_type);
3201       break;
3202
3203     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
3204     case elfcpp::R_X86_64_TLSDESC_CALL:
3205       if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
3206         {
3207           // See above comment for R_X86_64_TLSGD.
3208           optimized_type = tls::TLSOPT_NONE;
3209         }
3210       if (optimized_type == tls::TLSOPT_TO_LE)
3211         {
3212           if (tls_segment == NULL)
3213             {
3214               gold_assert(parameters->errors()->error_count() > 0
3215                           || issue_undefined_symbol_error(gsym));
3216               return;
3217             }
3218           this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
3219                                   rela, r_type, value, view,
3220                                   view_size);
3221           break;
3222         }
3223       else
3224         {
3225           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
3226                                    ? GOT_TYPE_TLS_OFFSET
3227                                    : GOT_TYPE_TLS_DESC);
3228           unsigned int got_offset = 0;
3229           if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC
3230               && optimized_type == tls::TLSOPT_NONE)
3231             {
3232               // We created GOT entries in the .got.tlsdesc portion of
3233               // the .got.plt section, but the offset stored in the
3234               // symbol is the offset within .got.tlsdesc.
3235               got_offset = (target->got_size()
3236                             + target->got_plt_section()->data_size());
3237             }
3238           if (gsym != NULL)
3239             {
3240               gold_assert(gsym->has_got_offset(got_type));
3241               got_offset += gsym->got_offset(got_type) - target->got_size();
3242             }
3243           else
3244             {
3245               unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
3246               gold_assert(object->local_has_got_offset(r_sym, got_type));
3247               got_offset += (object->local_got_offset(r_sym, got_type)
3248                              - target->got_size());
3249             }
3250           if (optimized_type == tls::TLSOPT_TO_IE)
3251             {
3252               if (tls_segment == NULL)
3253                 {
3254                   gold_assert(parameters->errors()->error_count() > 0
3255                               || issue_undefined_symbol_error(gsym));
3256                   return;
3257                 }
3258               value = target->got_plt_section()->address() + got_offset;
3259               this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment,
3260                                       rela, r_type, value, view, address,
3261                                       view_size);
3262               break;
3263             }
3264           else if (optimized_type == tls::TLSOPT_NONE)
3265             {
3266               if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
3267                 {
3268                   // Relocate the field with the offset of the pair of GOT
3269                   // entries.
3270                   value = target->got_plt_section()->address() + got_offset;
3271                   Relocate_functions<64, false>::pcrela32(view, value, addend,
3272                                                           address);
3273                 }
3274               break;
3275             }
3276         }
3277       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3278                              _("unsupported reloc %u"), r_type);
3279       break;
3280
3281     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
3282       if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
3283         {
3284           // See above comment for R_X86_64_TLSGD.
3285           optimized_type = tls::TLSOPT_NONE;
3286         }
3287       if (optimized_type == tls::TLSOPT_TO_LE)
3288         {
3289           if (tls_segment == NULL)
3290             {
3291               gold_assert(parameters->errors()->error_count() > 0
3292                           || issue_undefined_symbol_error(gsym));
3293               return;
3294             }
3295           this->tls_ld_to_le(relinfo, relnum, tls_segment, rela, r_type,
3296                              value, view, view_size);
3297           break;
3298         }
3299       else if (optimized_type == tls::TLSOPT_NONE)
3300         {
3301           // Relocate the field with the offset of the GOT entry for
3302           // the module index.
3303           unsigned int got_offset;
3304           got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
3305                         - target->got_size());
3306           value = target->got_plt_section()->address() + got_offset;
3307           Relocate_functions<64, false>::pcrela32(view, value, addend,
3308                                                   address);
3309           break;
3310         }
3311       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3312                              _("unsupported reloc %u"), r_type);
3313       break;
3314
3315     case elfcpp::R_X86_64_DTPOFF32:
3316       // This relocation type is used in debugging information.
3317       // In that case we need to not optimize the value.  If the
3318       // section is not executable, then we assume we should not
3319       // optimize this reloc.  See comments above for R_X86_64_TLSGD,
3320       // R_X86_64_GOTPC32_TLSDESC, R_X86_64_TLSDESC_CALL, and
3321       // R_X86_64_TLSLD.
3322       if (optimized_type == tls::TLSOPT_TO_LE && is_executable)
3323         {
3324           if (tls_segment == NULL)
3325             {
3326               gold_assert(parameters->errors()->error_count() > 0
3327                           || issue_undefined_symbol_error(gsym));
3328               return;
3329             }
3330           value -= tls_segment->memsz();
3331         }
3332       Relocate_functions<64, false>::rela32(view, value, addend);
3333       break;
3334
3335     case elfcpp::R_X86_64_DTPOFF64:
3336       // See R_X86_64_DTPOFF32, just above, for why we check for is_executable.
3337       if (optimized_type == tls::TLSOPT_TO_LE && is_executable)
3338         {
3339           if (tls_segment == NULL)
3340             {
3341               gold_assert(parameters->errors()->error_count() > 0
3342                           || issue_undefined_symbol_error(gsym));
3343               return;
3344             }
3345           value -= tls_segment->memsz();
3346         }
3347       Relocate_functions<64, false>::rela64(view, value, addend);
3348       break;
3349
3350     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
3351       if (optimized_type == tls::TLSOPT_TO_LE)
3352         {
3353           if (tls_segment == NULL)
3354             {
3355               gold_assert(parameters->errors()->error_count() > 0
3356                           || issue_undefined_symbol_error(gsym));
3357               return;
3358             }
3359           Target_x86_64::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
3360                                                 rela, r_type, value, view,
3361                                                 view_size);
3362           break;
3363         }
3364       else if (optimized_type == tls::TLSOPT_NONE)
3365         {
3366           // Relocate the field with the offset of the GOT entry for
3367           // the tp-relative offset of the symbol.
3368           unsigned int got_offset;
3369           if (gsym != NULL)
3370             {
3371               gold_assert(gsym->has_got_offset(GOT_TYPE_TLS_OFFSET));
3372               got_offset = (gsym->got_offset(GOT_TYPE_TLS_OFFSET)
3373                             - target->got_size());
3374             }
3375           else
3376             {
3377               unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
3378               gold_assert(object->local_has_got_offset(r_sym,
3379                                                        GOT_TYPE_TLS_OFFSET));
3380               got_offset = (object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET)
3381                             - target->got_size());
3382             }
3383           value = target->got_plt_section()->address() + got_offset;
3384           Relocate_functions<64, false>::pcrela32(view, value, addend, address);
3385           break;
3386         }
3387       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3388                              _("unsupported reloc type %u"),
3389                              r_type);
3390       break;
3391
3392     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
3393       if (tls_segment == NULL)
3394         {
3395           gold_assert(parameters->errors()->error_count() > 0
3396                       || issue_undefined_symbol_error(gsym));
3397           return;
3398         }
3399       value -= tls_segment->memsz();
3400       Relocate_functions<64, false>::rela32(view, value, addend);
3401       break;
3402     }
3403 }
3404
3405 // Do a relocation in which we convert a TLS General-Dynamic to an
3406 // Initial-Exec.
3407
3408 inline void
3409 Target_x86_64::Relocate::tls_gd_to_ie(const Relocate_info<64, false>* relinfo,
3410                                       size_t relnum,
3411                                       Output_segment*,
3412                                       const elfcpp::Rela<64, false>& rela,
3413                                       unsigned int,
3414                                       elfcpp::Elf_types<64>::Elf_Addr value,
3415                                       unsigned char* view,
3416                                       elfcpp::Elf_types<64>::Elf_Addr address,
3417                                       section_size_type view_size)
3418 {
3419   // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
3420   // .word 0x6666; rex64; call __tls_get_addr
3421   // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
3422
3423   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -4);
3424   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
3425
3426   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3427                  (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
3428   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3429                  (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0));
3430
3431   memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0", 16);
3432
3433   const elfcpp::Elf_Xword addend = rela.get_r_addend();
3434   Relocate_functions<64, false>::pcrela32(view + 8, value, addend - 8, address);
3435
3436   // The next reloc should be a PLT32 reloc against __tls_get_addr.
3437   // We can skip it.
3438   this->skip_call_tls_get_addr_ = true;
3439 }
3440
3441 // Do a relocation in which we convert a TLS General-Dynamic to a
3442 // Local-Exec.
3443
3444 inline void
3445 Target_x86_64::Relocate::tls_gd_to_le(const Relocate_info<64, false>* relinfo,
3446                                       size_t relnum,
3447                                       Output_segment* tls_segment,
3448                                       const elfcpp::Rela<64, false>& rela,
3449                                       unsigned int,
3450                                       elfcpp::Elf_types<64>::Elf_Addr value,
3451                                       unsigned char* view,
3452                                       section_size_type view_size)
3453 {
3454   // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
3455   // .word 0x6666; rex64; call __tls_get_addr
3456   // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
3457
3458   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -4);
3459   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
3460
3461   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3462                  (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
3463   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3464                  (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0));
3465
3466   memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0", 16);
3467
3468   value -= tls_segment->memsz();
3469   Relocate_functions<64, false>::rela32(view + 8, value, 0);
3470
3471   // The next reloc should be a PLT32 reloc against __tls_get_addr.
3472   // We can skip it.
3473   this->skip_call_tls_get_addr_ = true;
3474 }
3475
3476 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
3477
3478 inline void
3479 Target_x86_64::Relocate::tls_desc_gd_to_ie(
3480     const Relocate_info<64, false>* relinfo,
3481     size_t relnum,
3482     Output_segment*,
3483     const elfcpp::Rela<64, false>& rela,
3484     unsigned int r_type,
3485     elfcpp::Elf_types<64>::Elf_Addr value,
3486     unsigned char* view,
3487     elfcpp::Elf_types<64>::Elf_Addr address,
3488     section_size_type view_size)
3489 {
3490   if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
3491     {
3492       // leaq foo@tlsdesc(%rip), %rax
3493       // ==> movq foo@gottpoff(%rip), %rax
3494       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
3495       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
3496       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3497                      view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05);
3498       view[-2] = 0x8b;
3499       const elfcpp::Elf_Xword addend = rela.get_r_addend();
3500       Relocate_functions<64, false>::pcrela32(view, value, addend, address);
3501     }
3502   else
3503     {
3504       // call *foo@tlscall(%rax)
3505       // ==> nop; nop
3506       gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
3507       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
3508       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3509                      view[0] == 0xff && view[1] == 0x10);
3510       view[0] = 0x66;
3511       view[1] = 0x90;
3512     }
3513 }
3514
3515 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
3516
3517 inline void
3518 Target_x86_64::Relocate::tls_desc_gd_to_le(
3519     const Relocate_info<64, false>* relinfo,
3520     size_t relnum,
3521     Output_segment* tls_segment,
3522     const elfcpp::Rela<64, false>& rela,
3523     unsigned int r_type,
3524     elfcpp::Elf_types<64>::Elf_Addr value,
3525     unsigned char* view,
3526     section_size_type view_size)
3527 {
3528   if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
3529     {
3530       // leaq foo@tlsdesc(%rip), %rax
3531       // ==> movq foo@tpoff, %rax
3532       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
3533       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
3534       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3535                      view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05);
3536       view[-2] = 0xc7;
3537       view[-1] = 0xc0;
3538       value -= tls_segment->memsz();
3539       Relocate_functions<64, false>::rela32(view, value, 0);
3540     }
3541   else
3542     {
3543       // call *foo@tlscall(%rax)
3544       // ==> nop; nop
3545       gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
3546       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
3547       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3548                      view[0] == 0xff && view[1] == 0x10);
3549       view[0] = 0x66;
3550       view[1] = 0x90;
3551     }
3552 }
3553
3554 inline void
3555 Target_x86_64::Relocate::tls_ld_to_le(const Relocate_info<64, false>* relinfo,
3556                                       size_t relnum,
3557                                       Output_segment*,
3558                                       const elfcpp::Rela<64, false>& rela,
3559                                       unsigned int,
3560                                       elfcpp::Elf_types<64>::Elf_Addr,
3561                                       unsigned char* view,
3562                                       section_size_type view_size)
3563 {
3564   // leaq foo@tlsld(%rip),%rdi; call __tls_get_addr@plt;
3565   // ... leq foo@dtpoff(%rax),%reg
3566   // ==> .word 0x6666; .byte 0x66; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
3567
3568   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
3569   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 9);
3570
3571   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3572                  view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x3d);
3573
3574   tls::check_tls(relinfo, relnum, rela.get_r_offset(), view[4] == 0xe8);
3575
3576   memcpy(view - 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12);
3577
3578   // The next reloc should be a PLT32 reloc against __tls_get_addr.
3579   // We can skip it.
3580   this->skip_call_tls_get_addr_ = true;
3581 }
3582
3583 // Do a relocation in which we convert a TLS Initial-Exec to a
3584 // Local-Exec.
3585
3586 inline void
3587 Target_x86_64::Relocate::tls_ie_to_le(const Relocate_info<64, false>* relinfo,
3588                                       size_t relnum,
3589                                       Output_segment* tls_segment,
3590                                       const elfcpp::Rela<64, false>& rela,
3591                                       unsigned int,
3592                                       elfcpp::Elf_types<64>::Elf_Addr value,
3593                                       unsigned char* view,
3594                                       section_size_type view_size)
3595 {
3596   // We need to examine the opcodes to figure out which instruction we
3597   // are looking at.
3598
3599   // movq foo@gottpoff(%rip),%reg  ==>  movq $YY,%reg
3600   // addq foo@gottpoff(%rip),%reg  ==>  addq $YY,%reg
3601
3602   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
3603   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
3604
3605   unsigned char op1 = view[-3];
3606   unsigned char op2 = view[-2];
3607   unsigned char op3 = view[-1];
3608   unsigned char reg = op3 >> 3;
3609
3610   if (op2 == 0x8b)
3611     {
3612       // movq
3613       if (op1 == 0x4c)
3614         view[-3] = 0x49;
3615       view[-2] = 0xc7;
3616       view[-1] = 0xc0 | reg;
3617     }
3618   else if (reg == 4)
3619     {
3620       // Special handling for %rsp.
3621       if (op1 == 0x4c)
3622         view[-3] = 0x49;
3623       view[-2] = 0x81;
3624       view[-1] = 0xc0 | reg;
3625     }
3626   else
3627     {
3628       // addq
3629       if (op1 == 0x4c)
3630         view[-3] = 0x4d;
3631       view[-2] = 0x8d;
3632       view[-1] = 0x80 | reg | (reg << 3);
3633     }
3634
3635   value -= tls_segment->memsz();
3636   Relocate_functions<64, false>::rela32(view, value, 0);
3637 }
3638
3639 // Relocate section data.
3640
3641 void
3642 Target_x86_64::relocate_section(
3643     const Relocate_info<64, false>* relinfo,
3644     unsigned int sh_type,
3645     const unsigned char* prelocs,
3646     size_t reloc_count,
3647     Output_section* output_section,
3648     bool needs_special_offset_handling,
3649     unsigned char* view,
3650     elfcpp::Elf_types<64>::Elf_Addr address,
3651     section_size_type view_size,
3652     const Reloc_symbol_changes* reloc_symbol_changes)
3653 {
3654   gold_assert(sh_type == elfcpp::SHT_RELA);
3655
3656   gold::relocate_section<64, false, Target_x86_64, elfcpp::SHT_RELA,
3657                          Target_x86_64::Relocate>(
3658     relinfo,
3659     this,
3660     prelocs,
3661     reloc_count,
3662     output_section,
3663     needs_special_offset_handling,
3664     view,
3665     address,
3666     view_size,
3667     reloc_symbol_changes);
3668 }
3669
3670 // Apply an incremental relocation.  Incremental relocations always refer
3671 // to global symbols.
3672
3673 void
3674 Target_x86_64::apply_relocation(
3675     const Relocate_info<64, false>* relinfo,
3676     elfcpp::Elf_types<64>::Elf_Addr r_offset,
3677     unsigned int r_type,
3678     elfcpp::Elf_types<64>::Elf_Swxword r_addend,
3679     const Symbol* gsym,
3680     unsigned char* view,
3681     elfcpp::Elf_types<64>::Elf_Addr address,
3682     section_size_type view_size)
3683 {
3684   gold::apply_relocation<64, false, Target_x86_64, Target_x86_64::Relocate>(
3685     relinfo,
3686     this,
3687     r_offset,
3688     r_type,
3689     r_addend,
3690     gsym,
3691     view,
3692     address,
3693     view_size);
3694 }
3695
3696 // Return the size of a relocation while scanning during a relocatable
3697 // link.
3698
3699 unsigned int
3700 Target_x86_64::Relocatable_size_for_reloc::get_size_for_reloc(
3701     unsigned int r_type,
3702     Relobj* object)
3703 {
3704   switch (r_type)
3705     {
3706     case elfcpp::R_X86_64_NONE:
3707     case elfcpp::R_X86_64_GNU_VTINHERIT:
3708     case elfcpp::R_X86_64_GNU_VTENTRY:
3709     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
3710     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
3711     case elfcpp::R_X86_64_TLSDESC_CALL:
3712     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
3713     case elfcpp::R_X86_64_DTPOFF32:
3714     case elfcpp::R_X86_64_DTPOFF64:
3715     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
3716     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
3717       return 0;
3718
3719     case elfcpp::R_X86_64_64:
3720     case elfcpp::R_X86_64_PC64:
3721     case elfcpp::R_X86_64_GOTOFF64:
3722     case elfcpp::R_X86_64_GOTPC64:
3723     case elfcpp::R_X86_64_PLTOFF64:
3724     case elfcpp::R_X86_64_GOT64:
3725     case elfcpp::R_X86_64_GOTPCREL64:
3726     case elfcpp::R_X86_64_GOTPCREL:
3727     case elfcpp::R_X86_64_GOTPLT64:
3728       return 8;
3729
3730     case elfcpp::R_X86_64_32:
3731     case elfcpp::R_X86_64_32S:
3732     case elfcpp::R_X86_64_PC32:
3733     case elfcpp::R_X86_64_PLT32:
3734     case elfcpp::R_X86_64_GOTPC32:
3735     case elfcpp::R_X86_64_GOT32:
3736       return 4;
3737
3738     case elfcpp::R_X86_64_16:
3739     case elfcpp::R_X86_64_PC16:
3740       return 2;
3741
3742     case elfcpp::R_X86_64_8:
3743     case elfcpp::R_X86_64_PC8:
3744       return 1;
3745
3746     case elfcpp::R_X86_64_COPY:
3747     case elfcpp::R_X86_64_GLOB_DAT:
3748     case elfcpp::R_X86_64_JUMP_SLOT:
3749     case elfcpp::R_X86_64_RELATIVE:
3750     case elfcpp::R_X86_64_IRELATIVE:
3751       // These are outstanding tls relocs, which are unexpected when linking
3752     case elfcpp::R_X86_64_TPOFF64:
3753     case elfcpp::R_X86_64_DTPMOD64:
3754     case elfcpp::R_X86_64_TLSDESC:
3755       object->error(_("unexpected reloc %u in object file"), r_type);
3756       return 0;
3757
3758     case elfcpp::R_X86_64_SIZE32:
3759     case elfcpp::R_X86_64_SIZE64:
3760     default:
3761       object->error(_("unsupported reloc %u against local symbol"), r_type);
3762       return 0;
3763     }
3764 }
3765
3766 // Scan the relocs during a relocatable link.
3767
3768 void
3769 Target_x86_64::scan_relocatable_relocs(Symbol_table* symtab,
3770                                        Layout* layout,
3771                                        Sized_relobj_file<64, false>* object,
3772                                        unsigned int data_shndx,
3773                                        unsigned int sh_type,
3774                                        const unsigned char* prelocs,
3775                                        size_t reloc_count,
3776                                        Output_section* output_section,
3777                                        bool needs_special_offset_handling,
3778                                        size_t local_symbol_count,
3779                                        const unsigned char* plocal_symbols,
3780                                        Relocatable_relocs* rr)
3781 {
3782   gold_assert(sh_type == elfcpp::SHT_RELA);
3783
3784   typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_RELA,
3785     Relocatable_size_for_reloc> Scan_relocatable_relocs;
3786
3787   gold::scan_relocatable_relocs<64, false, elfcpp::SHT_RELA,
3788       Scan_relocatable_relocs>(
3789     symtab,
3790     layout,
3791     object,
3792     data_shndx,
3793     prelocs,
3794     reloc_count,
3795     output_section,
3796     needs_special_offset_handling,
3797     local_symbol_count,
3798     plocal_symbols,
3799     rr);
3800 }
3801
3802 // Relocate a section during a relocatable link.
3803
3804 void
3805 Target_x86_64::relocate_for_relocatable(
3806     const Relocate_info<64, false>* relinfo,
3807     unsigned int sh_type,
3808     const unsigned char* prelocs,
3809     size_t reloc_count,
3810     Output_section* output_section,
3811     off_t offset_in_output_section,
3812     const Relocatable_relocs* rr,
3813     unsigned char* view,
3814     elfcpp::Elf_types<64>::Elf_Addr view_address,
3815     section_size_type view_size,
3816     unsigned char* reloc_view,
3817     section_size_type reloc_view_size)
3818 {
3819   gold_assert(sh_type == elfcpp::SHT_RELA);
3820
3821   gold::relocate_for_relocatable<64, false, elfcpp::SHT_RELA>(
3822     relinfo,
3823     prelocs,
3824     reloc_count,
3825     output_section,
3826     offset_in_output_section,
3827     rr,
3828     view,
3829     view_address,
3830     view_size,
3831     reloc_view,
3832     reloc_view_size);
3833 }
3834
3835 // Return the value to use for a dynamic which requires special
3836 // treatment.  This is how we support equality comparisons of function
3837 // pointers across shared library boundaries, as described in the
3838 // processor specific ABI supplement.
3839
3840 uint64_t
3841 Target_x86_64::do_dynsym_value(const Symbol* gsym) const
3842 {
3843   gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
3844   return this->plt_address_for_global(gsym) + gsym->plt_offset();
3845 }
3846
3847 // Return a string used to fill a code section with nops to take up
3848 // the specified length.
3849
3850 std::string
3851 Target_x86_64::do_code_fill(section_size_type length) const
3852 {
3853   if (length >= 16)
3854     {
3855       // Build a jmpq instruction to skip over the bytes.
3856       unsigned char jmp[5];
3857       jmp[0] = 0xe9;
3858       elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
3859       return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
3860               + std::string(length - 5, '\0'));
3861     }
3862
3863   // Nop sequences of various lengths.
3864   const char nop1[1] = { 0x90 };                   // nop
3865   const char nop2[2] = { 0x66, 0x90 };             // xchg %ax %ax
3866   const char nop3[3] = { 0x0f, 0x1f, 0x00 };       // nop (%rax)
3867   const char nop4[4] = { 0x0f, 0x1f, 0x40, 0x00};  // nop 0(%rax)
3868   const char nop5[5] = { 0x0f, 0x1f, 0x44, 0x00,   // nop 0(%rax,%rax,1)
3869                          0x00 };
3870   const char nop6[6] = { 0x66, 0x0f, 0x1f, 0x44,   // nopw 0(%rax,%rax,1)
3871                          0x00, 0x00 };
3872   const char nop7[7] = { 0x0f, 0x1f, 0x80, 0x00,   // nopl 0L(%rax)
3873                          0x00, 0x00, 0x00 };
3874   const char nop8[8] = { 0x0f, 0x1f, 0x84, 0x00,   // nopl 0L(%rax,%rax,1)
3875                          0x00, 0x00, 0x00, 0x00 };
3876   const char nop9[9] = { 0x66, 0x0f, 0x1f, 0x84,   // nopw 0L(%rax,%rax,1)
3877                          0x00, 0x00, 0x00, 0x00,
3878                          0x00 };
3879   const char nop10[10] = { 0x66, 0x2e, 0x0f, 0x1f, // nopw %cs:0L(%rax,%rax,1)
3880                            0x84, 0x00, 0x00, 0x00,
3881                            0x00, 0x00 };
3882   const char nop11[11] = { 0x66, 0x66, 0x2e, 0x0f, // data16
3883                            0x1f, 0x84, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
3884                            0x00, 0x00, 0x00 };
3885   const char nop12[12] = { 0x66, 0x66, 0x66, 0x2e, // data16; data16
3886                            0x0f, 0x1f, 0x84, 0x00, // nopw %cs:0L(%rax,%rax,1)
3887                            0x00, 0x00, 0x00, 0x00 };
3888   const char nop13[13] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
3889                            0x2e, 0x0f, 0x1f, 0x84, // nopw %cs:0L(%rax,%rax,1)
3890                            0x00, 0x00, 0x00, 0x00,
3891                            0x00 };
3892   const char nop14[14] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
3893                            0x66, 0x2e, 0x0f, 0x1f, // data16
3894                            0x84, 0x00, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
3895                            0x00, 0x00 };
3896   const char nop15[15] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
3897                            0x66, 0x66, 0x2e, 0x0f, // data16; data16
3898                            0x1f, 0x84, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
3899                            0x00, 0x00, 0x00 };
3900
3901   const char* nops[16] = {
3902     NULL,
3903     nop1, nop2, nop3, nop4, nop5, nop6, nop7,
3904     nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
3905   };
3906
3907   return std::string(nops[length], length);
3908 }
3909
3910 // Return the addend to use for a target specific relocation.  The
3911 // only target specific relocation is R_X86_64_TLSDESC for a local
3912 // symbol.  We want to set the addend is the offset of the local
3913 // symbol in the TLS segment.
3914
3915 uint64_t
3916 Target_x86_64::do_reloc_addend(void* arg, unsigned int r_type,
3917                                uint64_t) const
3918 {
3919   gold_assert(r_type == elfcpp::R_X86_64_TLSDESC);
3920   uintptr_t intarg = reinterpret_cast<uintptr_t>(arg);
3921   gold_assert(intarg < this->tlsdesc_reloc_info_.size());
3922   const Tlsdesc_info& ti(this->tlsdesc_reloc_info_[intarg]);
3923   const Symbol_value<64>* psymval = ti.object->local_symbol(ti.r_sym);
3924   gold_assert(psymval->is_tls_symbol());
3925   // The value of a TLS symbol is the offset in the TLS segment.
3926   return psymval->value(ti.object, 0);
3927 }
3928
3929 // Return the value to use for the base of a DW_EH_PE_datarel offset
3930 // in an FDE.  Solaris and SVR4 use DW_EH_PE_datarel because their
3931 // assembler can not write out the difference between two labels in
3932 // different sections, so instead of using a pc-relative value they
3933 // use an offset from the GOT.
3934
3935 uint64_t
3936 Target_x86_64::do_ehframe_datarel_base() const
3937 {
3938   gold_assert(this->global_offset_table_ != NULL);
3939   Symbol* sym = this->global_offset_table_;
3940   Sized_symbol<64>* ssym = static_cast<Sized_symbol<64>*>(sym);
3941   return ssym->value();
3942 }
3943
3944 // FNOFFSET in section SHNDX in OBJECT is the start of a function
3945 // compiled with -fsplit-stack.  The function calls non-split-stack
3946 // code.  We have to change the function so that it always ensures
3947 // that it has enough stack space to run some random function.
3948
3949 void
3950 Target_x86_64::do_calls_non_split(Relobj* object, unsigned int shndx,
3951                                   section_offset_type fnoffset,
3952                                   section_size_type fnsize,
3953                                   unsigned char* view,
3954                                   section_size_type view_size,
3955                                   std::string* from,
3956                                   std::string* to) const
3957 {
3958   // The function starts with a comparison of the stack pointer and a
3959   // field in the TCB.  This is followed by a jump.
3960
3961   // cmp %fs:NN,%rsp
3962   if (this->match_view(view, view_size, fnoffset, "\x64\x48\x3b\x24\x25", 5)
3963       && fnsize > 9)
3964     {
3965       // We will call __morestack if the carry flag is set after this
3966       // comparison.  We turn the comparison into an stc instruction
3967       // and some nops.
3968       view[fnoffset] = '\xf9';
3969       this->set_view_to_nop(view, view_size, fnoffset + 1, 8);
3970     }
3971   // lea NN(%rsp),%r10
3972   // lea NN(%rsp),%r11
3973   else if ((this->match_view(view, view_size, fnoffset,
3974                              "\x4c\x8d\x94\x24", 4)
3975             || this->match_view(view, view_size, fnoffset,
3976                                 "\x4c\x8d\x9c\x24", 4))
3977            && fnsize > 8)
3978     {
3979       // This is loading an offset from the stack pointer for a
3980       // comparison.  The offset is negative, so we decrease the
3981       // offset by the amount of space we need for the stack.  This
3982       // means we will avoid calling __morestack if there happens to
3983       // be plenty of space on the stack already.
3984       unsigned char* pval = view + fnoffset + 4;
3985       uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
3986       val -= parameters->options().split_stack_adjust_size();
3987       elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
3988     }
3989   else
3990     {
3991       if (!object->has_no_split_stack())
3992         object->error(_("failed to match split-stack sequence at "
3993                         "section %u offset %0zx"),
3994                       shndx, static_cast<size_t>(fnoffset));
3995       return;
3996     }
3997
3998   // We have to change the function so that it calls
3999   // __morestack_non_split instead of __morestack.  The former will
4000   // allocate additional stack space.
4001   *from = "__morestack";
4002   *to = "__morestack_non_split";
4003 }
4004
4005 // The selector for x86_64 object files.
4006
4007 class Target_selector_x86_64 : public Target_selector_freebsd
4008 {
4009 public:
4010   Target_selector_x86_64()
4011     : Target_selector_freebsd(elfcpp::EM_X86_64, 64, false, "elf64-x86-64",
4012                               "elf64-x86-64-freebsd", "elf_x86_64")
4013   { }
4014
4015   Target*
4016   do_instantiate_target()
4017   { return new Target_x86_64(); }
4018
4019 };
4020
4021 Target_selector_x86_64 target_selector_x86_64;
4022
4023 } // End anonymous namespace.