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 template<int size>
  53 class Output_data_plt_x86_64 : public Output_section_data
  54 {
  55  public:
  56   typedef Output_data_reloc<elfcpp::SHT_RELA, true, size, false> Reloc_section;
  57
  58   Output_data_plt_x86_64(Layout* layout, Output_data_got<64, false>* got,
  59                          Output_data_space* got_plt,
  60                          Output_data_space* got_irelative)
  61     : Output_section_data(16), layout_(layout), tlsdesc_rel_(NULL),
  62       irelative_rel_(NULL), got_(got), got_plt_(got_plt),
  63       got_irelative_(got_irelative), count_(0), irelative_count_(0),
  64       tlsdesc_got_offset_(-1U), free_list_()
  65   { this->init(layout); }
  66
  67   Output_data_plt_x86_64(Layout* layout, Output_data_got<64, false>* got,
  68                          Output_data_space* got_plt,
  69                          Output_data_space* got_irelative,
  70                          unsigned int plt_count)
  71     : Output_section_data((plt_count + 1) * plt_entry_size, 16, false),
  72       layout_(layout), tlsdesc_rel_(NULL), irelative_rel_(NULL), got_(got),
  73       got_plt_(got_plt), got_irelative_(got_irelative), count_(plt_count),
  74       irelative_count_(0), tlsdesc_got_offset_(-1U), free_list_()
  75   {
  76     this->init(layout);
  77
  78     // Initialize the free list and reserve the first entry.
  79     this->free_list_.init((plt_count + 1) * plt_entry_size, false);
  80     this->free_list_.remove(0, plt_entry_size);
  81   }
  82
  83   // Initialize the PLT section.
  84   void
  85   init(Layout* layout);
  86
  87   // Add an entry to the PLT.
  88   void
  89   add_entry(Symbol_table*, Layout*, Symbol* gsym);
  90
  91   // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
  92   unsigned int
  93   add_local_ifunc_entry(Symbol_table* symtab, Layout*,
  94                         Sized_relobj_file<size, false>* relobj,
  95                         unsigned int local_sym_index);
  96
  97   // Add the relocation for a PLT entry.
  98   void
  99   add_relocation(Symbol_table*, Layout*, Symbol* gsym,
 100                  unsigned int got_offset);
 101
 102   // Add the reserved TLSDESC_PLT entry to the PLT.
 103   void
 104   reserve_tlsdesc_entry(unsigned int got_offset)
 105   { this->tlsdesc_got_offset_ = got_offset; }
 106
 107   // Return true if a TLSDESC_PLT entry has been reserved.
 108   bool
 109   has_tlsdesc_entry() const
 110   { return this->tlsdesc_got_offset_ != -1U; }
 111
 112   // Return the GOT offset for the reserved TLSDESC_PLT entry.
 113   unsigned int
 114   get_tlsdesc_got_offset() const
 115   { return this->tlsdesc_got_offset_; }
 116
 117   // Return the offset of the reserved TLSDESC_PLT entry.
 118   unsigned int
 119   get_tlsdesc_plt_offset() const
 120   { return (this->count_ + this->irelative_count_ + 1) * plt_entry_size; }
 121
 122   // Return the .rela.plt section data.
 123   Reloc_section*
 124   rela_plt()
 125   { return this->rel_; }
 126
 127   // Return where the TLSDESC relocations should go.
 128   Reloc_section*
 129   rela_tlsdesc(Layout*);
 130
 131   // Return where the IRELATIVE relocations should go in the PLT
 132   // relocations.
 133   Reloc_section*
 134   rela_irelative(Symbol_table*, Layout*);
 135
 136   // Return whether we created a section for IRELATIVE relocations.
 137   bool
 138   has_irelative_section() const
 139   { return this->irelative_rel_ != NULL; }
 140
 141   // Return the number of PLT entries.
 142   unsigned int
 143   entry_count() const
 144   { return this->count_ + this->irelative_count_; }
 145
 146   // Return the offset of the first non-reserved PLT entry.
 147   static unsigned int
 148   first_plt_entry_offset()
 149   { return plt_entry_size; }
 150
 151   // Return the size of a PLT entry.
 152   static unsigned int
 153   get_plt_entry_size()
 154   { return plt_entry_size; }
 155
 156   // Reserve a slot in the PLT for an existing symbol in an incremental update.
 157   void
 158   reserve_slot(unsigned int plt_index)
 159   {
 160     this->free_list_.remove((plt_index + 1) * plt_entry_size,
 161                             (plt_index + 2) * plt_entry_size);
 162   }
 163
 164   // Return the PLT address to use for a global symbol.
 165   uint64_t
 166   address_for_global(const Symbol*);
 167
 168   // Return the PLT address to use for a local symbol.
 169   uint64_t
 170   address_for_local(const Relobj*, unsigned int symndx);
 171
 172  protected:
 173   void
 174   do_adjust_output_section(Output_section* os);
 175
 176   // Write to a map file.
 177   void
 178   do_print_to_mapfile(Mapfile* mapfile) const
 179   { mapfile->print_output_data(this, _("** PLT")); }
 180
 181  private:
 182   // The size of an entry in the PLT.
 183   static const int plt_entry_size = 16;
 184
 185   // The first entry in the PLT.
 186   // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
 187   // procedure linkage table for both programs and shared objects."
 188   static const unsigned char first_plt_entry[plt_entry_size];
 189
 190   // Other entries in the PLT for an executable.
 191   static const unsigned char plt_entry[plt_entry_size];
 192
 193   // The reserved TLSDESC entry in the PLT for an executable.
 194   static const unsigned char tlsdesc_plt_entry[plt_entry_size];
 195
 196   // The .eh_frame unwind information for the PLT.
 197   static const int plt_eh_frame_cie_size = 16;
 198   static const int plt_eh_frame_fde_size = 32;
 199   static const unsigned char plt_eh_frame_cie[plt_eh_frame_cie_size];
 200   static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
 201
 202   // Set the final size.
 203   void
 204   set_final_data_size();
 205
 206   // Write out the PLT data.
 207   void
 208   do_write(Output_file*);
 209
 210   // A pointer to the Layout class, so that we can find the .dynamic
 211   // section when we write out the GOT PLT section.
 212   Layout* layout_;
 213   // The reloc section.
 214   Reloc_section* rel_;
 215   // The TLSDESC relocs, if necessary.  These must follow the regular
 216   // PLT relocs.
 217   Reloc_section* tlsdesc_rel_;
 218   // The IRELATIVE relocs, if necessary.  These must follow the
 219   // regular PLT relocations and the TLSDESC relocations.
 220   Reloc_section* irelative_rel_;
 221   // The .got section.
 222   Output_data_got<64, false>* got_;
 223   // The .got.plt section.
 224   Output_data_space* got_plt_;
 225   // The part of the .got.plt section used for IRELATIVE relocs.
 226   Output_data_space* got_irelative_;
 227   // The number of PLT entries.
 228   unsigned int count_;
 229   // Number of PLT entries with R_X86_64_IRELATIVE relocs.  These
 230   // follow the regular PLT entries.
 231   unsigned int irelative_count_;
 232   // Offset of the reserved TLSDESC_GOT entry when needed.
 233   unsigned int tlsdesc_got_offset_;
 234   // List of available regions within the section, for incremental
 235   // update links.
 236   Free_list free_list_;
 237 };
 238
 239 // The x86_64 target class.
 240 // See the ABI at
 241 //   http://www.x86-64.org/documentation/abi.pdf
 242 // TLS info comes from
 243 //   http://people.redhat.com/drepper/tls.pdf
 244 //   http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
 245
 246 template<int size>
 247 class Target_x86_64 : public Sized_target<size, false>
 248 {
 249  public:
 250   // In the x86_64 ABI (p 68), it says "The AMD64 ABI architectures
 251   // uses only Elf64_Rela relocation entries with explicit addends."
 252   typedef Output_data_reloc<elfcpp::SHT_RELA, true, size, false> Reloc_section;
 253
 254   Target_x86_64()
 255     : Sized_target<size, false>(&x86_64_info),
 256       got_(NULL), plt_(NULL), got_plt_(NULL), got_irelative_(NULL),
 257       got_tlsdesc_(NULL), global_offset_table_(NULL), rela_dyn_(NULL),
 258       rela_irelative_(NULL), copy_relocs_(elfcpp::R_X86_64_COPY),
 259       dynbss_(NULL), got_mod_index_offset_(-1U), tlsdesc_reloc_info_(),
 260       tls_base_symbol_defined_(false)
 261   { }
 262
 263   // Hook for a new output section.
 264   void
 265   do_new_output_section(Output_section*) const;
 266
 267   // Scan the relocations to look for symbol adjustments.
 268   void
 269   gc_process_relocs(Symbol_table* symtab,
 270                     Layout* layout,
 271                     Sized_relobj_file<size, false>* object,
 272                     unsigned int data_shndx,
 273                     unsigned int sh_type,
 274                     const unsigned char* prelocs,
 275                     size_t reloc_count,
 276                     Output_section* output_section,
 277                     bool needs_special_offset_handling,
 278                     size_t local_symbol_count,
 279                     const unsigned char* plocal_symbols);
 280
 281   // Scan the relocations to look for symbol adjustments.
 282   void
 283   scan_relocs(Symbol_table* symtab,
 284               Layout* layout,
 285               Sized_relobj_file<size, false>* object,
 286               unsigned int data_shndx,
 287               unsigned int sh_type,
 288               const unsigned char* prelocs,
 289               size_t reloc_count,
 290               Output_section* output_section,
 291               bool needs_special_offset_handling,
 292               size_t local_symbol_count,
 293               const unsigned char* plocal_symbols);
 294
 295   // Finalize the sections.
 296   void
 297   do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
 298
 299   // Return the value to use for a dynamic which requires special
 300   // treatment.
 301   uint64_t
 302   do_dynsym_value(const Symbol*) const;
 303
 304   // Relocate a section.
 305   void
 306   relocate_section(const Relocate_info<size, false>*,
 307                    unsigned int sh_type,
 308                    const unsigned char* prelocs,
 309                    size_t reloc_count,
 310                    Output_section* output_section,
 311                    bool needs_special_offset_handling,
 312                    unsigned char* view,
 313                    typename elfcpp::Elf_types<size>::Elf_Addr view_address,
 314                    section_size_type view_size,
 315                    const Reloc_symbol_changes*);
 316
 317   // Scan the relocs during a relocatable link.
 318   void
 319   scan_relocatable_relocs(Symbol_table* symtab,
 320                           Layout* layout,
 321                           Sized_relobj_file<size, false>* object,
 322                           unsigned int data_shndx,
 323                           unsigned int sh_type,
 324                           const unsigned char* prelocs,
 325                           size_t reloc_count,
 326                           Output_section* output_section,
 327                           bool needs_special_offset_handling,
 328                           size_t local_symbol_count,
 329                           const unsigned char* plocal_symbols,
 330                           Relocatable_relocs*);
 331
 332   // Relocate a section during a relocatable link.
 333   void
 334   relocate_for_relocatable(
 335       const Relocate_info<size, false>*,
 336       unsigned int sh_type,
 337       const unsigned char* prelocs,
 338       size_t reloc_count,
 339       Output_section* output_section,
 340       off_t offset_in_output_section,
 341       const Relocatable_relocs*,
 342       unsigned char* view,
 343       typename elfcpp::Elf_types<size>::Elf_Addr view_address,
 344       section_size_type view_size,
 345       unsigned char* reloc_view,
 346       section_size_type reloc_view_size);
 347
 348   // Return a string used to fill a code section with nops.
 349   std::string
 350   do_code_fill(section_size_type length) const;
 351
 352   // Return whether SYM is defined by the ABI.
 353   bool
 354   do_is_defined_by_abi(const Symbol* sym) const
 355   { return strcmp(sym->name(), "__tls_get_addr") == 0; }
 356
 357   // Return the symbol index to use for a target specific relocation.
 358   // The only target specific relocation is R_X86_64_TLSDESC for a
 359   // local symbol, which is an absolute reloc.
 360   unsigned int
 361   do_reloc_symbol_index(void*, unsigned int r_type) const
 362   {
 363     gold_assert(r_type == elfcpp::R_X86_64_TLSDESC);
 364     return 0;
 365   }
 366
 367   // Return the addend to use for a target specific relocation.
 368   uint64_t
 369   do_reloc_addend(void* arg, unsigned int r_type, uint64_t addend) const;
 370
 371   // Return the PLT section.
 372   uint64_t
 373   do_plt_address_for_global(const Symbol* gsym) const
 374   { return this->plt_section()->address_for_global(gsym); }
 375
 376   uint64_t
 377   do_plt_address_for_local(const Relobj* relobj, unsigned int symndx) const
 378   { return this->plt_section()->address_for_local(relobj, symndx); }
 379
 380   // This function should be defined in targets that can use relocation
 381   // types to determine (implemented in local_reloc_may_be_function_pointer
 382   // and global_reloc_may_be_function_pointer)
 383   // if a function's pointer is taken.  ICF uses this in safe mode to only
 384   // fold those functions whose pointer is defintely not taken.  For x86_64
 385   // pie binaries, safe ICF cannot be done by looking at relocation types.
 386   bool
 387   do_can_check_for_function_pointers() const
 388   { return !parameters->options().pie(); }
 389
 390   // Return the base for a DW_EH_PE_datarel encoding.
 391   uint64_t
 392   do_ehframe_datarel_base() const;
 393
 394   // Adjust -fsplit-stack code which calls non-split-stack code.
 395   void
 396   do_calls_non_split(Relobj* object, unsigned int shndx,
 397                      section_offset_type fnoffset, section_size_type fnsize,
 398                      unsigned char* view, section_size_type view_size,
 399                      std::string* from, std::string* to) const;
 400
 401   // Return the size of the GOT section.
 402   section_size_type
 403   got_size() const
 404   {
 405     gold_assert(this->got_ != NULL);
 406     return this->got_->data_size();
 407   }
 408
 409   // Return the number of entries in the GOT.
 410   unsigned int
 411   got_entry_count() const
 412   {
 413     if (this->got_ == NULL)
 414       return 0;
 415     return this->got_size() / 8;
 416   }
 417
 418   // Return the number of entries in the PLT.
 419   unsigned int
 420   plt_entry_count() const;
 421
 422   // Return the offset of the first non-reserved PLT entry.
 423   unsigned int
 424   first_plt_entry_offset() const;
 425
 426   // Return the size of each PLT entry.
 427   unsigned int
 428   plt_entry_size() const;
 429
 430   // Create the GOT section for an incremental update.
 431   Output_data_got_base*
 432   init_got_plt_for_update(Symbol_table* symtab,
 433                           Layout* layout,
 434                           unsigned int got_count,
 435                           unsigned int plt_count);
 436
 437   // Reserve a GOT entry for a local symbol, and regenerate any
 438   // necessary dynamic relocations.
 439   void
 440   reserve_local_got_entry(unsigned int got_index,
 441                           Sized_relobj<size, false>* obj,
 442                           unsigned int r_sym,
 443                           unsigned int got_type);
 444
 445   // Reserve a GOT entry for a global symbol, and regenerate any
 446   // necessary dynamic relocations.
 447   void
 448   reserve_global_got_entry(unsigned int got_index, Symbol* gsym,
 449                            unsigned int got_type);
 450
 451   // Register an existing PLT entry for a global symbol.
 452   void
 453   register_global_plt_entry(Symbol_table*, Layout*, unsigned int plt_index,
 454                             Symbol* gsym);
 455
 456   // Force a COPY relocation for a given symbol.
 457   void
 458   emit_copy_reloc(Symbol_table*, Symbol*, Output_section*, off_t);
 459
 460   // Apply an incremental relocation.
 461   void
 462   apply_relocation(const Relocate_info<size, false>* relinfo,
 463                    typename elfcpp::Elf_types<size>::Elf_Addr r_offset,
 464                    unsigned int r_type,
 465                    typename elfcpp::Elf_types<size>::Elf_Swxword r_addend,
 466                    const Symbol* gsym,
 467                    unsigned char* view,
 468                    typename elfcpp::Elf_types<size>::Elf_Addr address,
 469                    section_size_type view_size);
 470
 471   // Add a new reloc argument, returning the index in the vector.
 472   size_t
 473   add_tlsdesc_info(Sized_relobj_file<size, false>* object, unsigned int r_sym)
 474   {
 475     this->tlsdesc_reloc_info_.push_back(Tlsdesc_info(object, r_sym));
 476     return this->tlsdesc_reloc_info_.size() - 1;
 477   }
 478
 479  private:
 480   // The class which scans relocations.
 481   class Scan
 482   {
 483   public:
 484     Scan()
 485       : issued_non_pic_error_(false)
 486     { }
 487
 488     static inline int
 489     get_reference_flags(unsigned int r_type);
 490
 491     inline void
 492     local(Symbol_table* symtab, Layout* layout, Target_x86_64* target,
 493           Sized_relobj_file<size, false>* object,
 494           unsigned int data_shndx,
 495           Output_section* output_section,
 496           const elfcpp::Rela<size, false>& reloc, unsigned int r_type,
 497           const elfcpp::Sym<size, false>& lsym);
 498
 499     inline void
 500     global(Symbol_table* symtab, Layout* layout, Target_x86_64* target,
 501            Sized_relobj_file<size, false>* object,
 502            unsigned int data_shndx,
 503            Output_section* output_section,
 504            const elfcpp::Rela<size, false>& reloc, unsigned int r_type,
 505            Symbol* gsym);
 506
 507     inline bool
 508     local_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
 509                                         Target_x86_64* target,
 510                                         Sized_relobj_file<size, false>* object,
 511                                         unsigned int data_shndx,
 512                                         Output_section* output_section,
 513                                         const elfcpp::Rela<size, false>& reloc,
 514                                         unsigned int r_type,
 515                                         const elfcpp::Sym<size, false>& lsym);
 516
 517     inline bool
 518     global_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
 519                                          Target_x86_64* target,
 520                                          Sized_relobj_file<size, false>* object,
 521                                          unsigned int data_shndx,
 522                                          Output_section* output_section,
 523                                          const elfcpp::Rela<size, false>& reloc,
 524                                          unsigned int r_type,
 525                                          Symbol* gsym);
 526
 527   private:
 528     static void
 529     unsupported_reloc_local(Sized_relobj_file<size, false>*,
 530                             unsigned int r_type);
 531
 532     static void
 533     unsupported_reloc_global(Sized_relobj_file<size, false>*,
 534                              unsigned int r_type, Symbol*);
 535
 536     void
 537     check_non_pic(Relobj*, unsigned int r_type, Symbol*);
 538
 539     inline bool
 540     possible_function_pointer_reloc(unsigned int r_type);
 541
 542     bool
 543     reloc_needs_plt_for_ifunc(Sized_relobj_file<size, false>*,
 544                               unsigned int r_type);
 545
 546     // Whether we have issued an error about a non-PIC compilation.
 547     bool issued_non_pic_error_;
 548   };
 549
 550   // The class which implements relocation.
 551   class Relocate
 552   {
 553    public:
 554     Relocate()
 555       : skip_call_tls_get_addr_(false)
 556     { }
 557
 558     ~Relocate()
 559     {
 560       if (this->skip_call_tls_get_addr_)
 561         {
 562           // FIXME: This needs to specify the location somehow.
 563           gold_error(_("missing expected TLS relocation"));
 564         }
 565     }
 566
 567     // Do a relocation.  Return false if the caller should not issue
 568     // any warnings about this relocation.
 569     inline bool
 570     relocate(const Relocate_info<size, false>*, Target_x86_64*,
 571              Output_section*,
 572              size_t relnum, const elfcpp::Rela<size, false>&,
 573              unsigned int r_type, const Sized_symbol<size>*,
 574              const Symbol_value<size>*,
 575              unsigned char*, typename elfcpp::Elf_types<size>::Elf_Addr,
 576              section_size_type);
 577
 578    private:
 579     // Do a TLS relocation.
 580     inline void
 581     relocate_tls(const Relocate_info<size, false>*, Target_x86_64*,
 582                  size_t relnum, const elfcpp::Rela<size, false>&,
 583                  unsigned int r_type, const Sized_symbol<size>*,
 584                  const Symbol_value<size>*,
 585                  unsigned char*, typename elfcpp::Elf_types<size>::Elf_Addr,
 586                  section_size_type);
 587
 588     // Do a TLS General-Dynamic to Initial-Exec transition.
 589     inline void
 590     tls_gd_to_ie(const Relocate_info<size, false>*, size_t relnum,
 591                  Output_segment* tls_segment,
 592                  const elfcpp::Rela<size, false>&, unsigned int r_type,
 593                  typename elfcpp::Elf_types<size>::Elf_Addr value,
 594                  unsigned char* view,
 595                  typename elfcpp::Elf_types<size>::Elf_Addr,
 596                  section_size_type view_size);
 597
 598     // Do a TLS General-Dynamic to Local-Exec transition.
 599     inline void
 600     tls_gd_to_le(const Relocate_info<size, false>*, size_t relnum,
 601                  Output_segment* tls_segment,
 602                  const elfcpp::Rela<size, false>&, unsigned int r_type,
 603                  typename elfcpp::Elf_types<size>::Elf_Addr value,
 604                  unsigned char* view,
 605                  section_size_type view_size);
 606
 607     // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
 608     inline void
 609     tls_desc_gd_to_ie(const Relocate_info<size, false>*, size_t relnum,
 610                       Output_segment* tls_segment,
 611                       const elfcpp::Rela<size, false>&, unsigned int r_type,
 612                       typename elfcpp::Elf_types<size>::Elf_Addr value,
 613                       unsigned char* view,
 614                       typename elfcpp::Elf_types<size>::Elf_Addr,
 615                       section_size_type view_size);
 616
 617     // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
 618     inline void
 619     tls_desc_gd_to_le(const Relocate_info<size, false>*, size_t relnum,
 620                       Output_segment* tls_segment,
 621                       const elfcpp::Rela<size, false>&, unsigned int r_type,
 622                       typename elfcpp::Elf_types<size>::Elf_Addr value,
 623                       unsigned char* view,
 624                       section_size_type view_size);
 625
 626     // Do a TLS Local-Dynamic to Local-Exec transition.
 627     inline void
 628     tls_ld_to_le(const Relocate_info<size, false>*, size_t relnum,
 629                  Output_segment* tls_segment,
 630                  const elfcpp::Rela<size, false>&, unsigned int r_type,
 631                  typename elfcpp::Elf_types<size>::Elf_Addr value,
 632                  unsigned char* view,
 633                  section_size_type view_size);
 634
 635     // Do a TLS Initial-Exec to Local-Exec transition.
 636     static inline void
 637     tls_ie_to_le(const Relocate_info<size, false>*, size_t relnum,
 638                  Output_segment* tls_segment,
 639                  const elfcpp::Rela<size, false>&, unsigned int r_type,
 640                  typename elfcpp::Elf_types<size>::Elf_Addr value,
 641                  unsigned char* view,
 642                  section_size_type view_size);
 643
 644     // This is set if we should skip the next reloc, which should be a
 645     // PLT32 reloc against ___tls_get_addr.
 646     bool skip_call_tls_get_addr_;
 647   };
 648
 649   // A class which returns the size required for a relocation type,
 650   // used while scanning relocs during a relocatable link.
 651   class Relocatable_size_for_reloc
 652   {
 653    public:
 654     unsigned int
 655     get_size_for_reloc(unsigned int, Relobj*);
 656   };
 657
 658   // Adjust TLS relocation type based on the options and whether this
 659   // is a local symbol.
 660   static tls::Tls_optimization
 661   optimize_tls_reloc(bool is_final, int r_type);
 662
 663   // Get the GOT section, creating it if necessary.
 664   Output_data_got<64, false>*
 665   got_section(Symbol_table*, Layout*);
 666
 667   // Get the GOT PLT section.
 668   Output_data_space*
 669   got_plt_section() const
 670   {
 671     gold_assert(this->got_plt_ != NULL);
 672     return this->got_plt_;
 673   }
 674
 675   // Get the GOT section for TLSDESC entries.
 676   Output_data_got<64, false>*
 677   got_tlsdesc_section() const
 678   {
 679     gold_assert(this->got_tlsdesc_ != NULL);
 680     return this->got_tlsdesc_;
 681   }
 682
 683   // Create the PLT section.
 684   void
 685   make_plt_section(Symbol_table* symtab, Layout* layout);
 686
 687   // Create a PLT entry for a global symbol.
 688   void
 689   make_plt_entry(Symbol_table*, Layout*, Symbol*);
 690
 691   // Create a PLT entry for a local STT_GNU_IFUNC symbol.
 692   void
 693   make_local_ifunc_plt_entry(Symbol_table*, Layout*,
 694                              Sized_relobj_file<size, false>* relobj,
 695                              unsigned int local_sym_index);
 696
 697   // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
 698   void
 699   define_tls_base_symbol(Symbol_table*, Layout*);
 700
 701   // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
 702   void
 703   reserve_tlsdesc_entries(Symbol_table* symtab, Layout* layout);
 704
 705   // Create a GOT entry for the TLS module index.
 706   unsigned int
 707   got_mod_index_entry(Symbol_table* symtab, Layout* layout,
 708                       Sized_relobj_file<size, false>* object);
 709
 710   // Get the PLT section.
 711   Output_data_plt_x86_64<size>*
 712   plt_section() const
 713   {
 714     gold_assert(this->plt_ != NULL);
 715     return this->plt_;
 716   }
 717
 718   // Get the dynamic reloc section, creating it if necessary.
 719   Reloc_section*
 720   rela_dyn_section(Layout*);
 721
 722   // Get the section to use for TLSDESC relocations.
 723   Reloc_section*
 724   rela_tlsdesc_section(Layout*) const;
 725
 726   // Get the section to use for IRELATIVE relocations.
 727   Reloc_section*
 728   rela_irelative_section(Layout*);
 729
 730   // Add a potential copy relocation.
 731   void
 732   copy_reloc(Symbol_table* symtab, Layout* layout,
 733              Sized_relobj_file<size, false>* object,
 734              unsigned int shndx, Output_section* output_section,
 735              Symbol* sym, const elfcpp::Rela<size, false>& reloc)
 736   {
 737     this->copy_relocs_.copy_reloc(symtab, layout,
 738                                   symtab->get_sized_symbol<size>(sym),
 739                                   object, shndx, output_section,
 740                                   reloc, this->rela_dyn_section(layout));
 741   }
 742
 743   // Information about this specific target which we pass to the
 744   // general Target structure.
 745   static const Target::Target_info x86_64_info;
 746
 747   // The types of GOT entries needed for this platform.
 748   // These values are exposed to the ABI in an incremental link.
 749   // Do not renumber existing values without changing the version
 750   // number of the .gnu_incremental_inputs section.
 751   enum Got_type
 752   {
 753     GOT_TYPE_STANDARD = 0,      // GOT entry for a regular symbol
 754     GOT_TYPE_TLS_OFFSET = 1,    // GOT entry for TLS offset
 755     GOT_TYPE_TLS_PAIR = 2,      // GOT entry for TLS module/offset pair
 756     GOT_TYPE_TLS_DESC = 3       // GOT entry for TLS_DESC pair
 757   };
 758
 759   // This type is used as the argument to the target specific
 760   // relocation routines.  The only target specific reloc is
 761   // R_X86_64_TLSDESC against a local symbol.
 762   struct Tlsdesc_info
 763   {
 764     Tlsdesc_info(Sized_relobj_file<size, false>* a_object, unsigned int a_r_sym)
 765       : object(a_object), r_sym(a_r_sym)
 766     { }
 767
 768     // The object in which the local symbol is defined.
 769     Sized_relobj_file<size, false>* object;
 770     // The local symbol index in the object.
 771     unsigned int r_sym;
 772   };
 773
 774   // The GOT section.
 775   Output_data_got<64, false>* got_;
 776   // The PLT section.
 777   Output_data_plt_x86_64<size>* plt_;
 778   // The GOT PLT section.
 779   Output_data_space* got_plt_;
 780   // The GOT section for IRELATIVE relocations.
 781   Output_data_space* got_irelative_;
 782   // The GOT section for TLSDESC relocations.
 783   Output_data_got<64, false>* got_tlsdesc_;
 784   // The _GLOBAL_OFFSET_TABLE_ symbol.
 785   Symbol* global_offset_table_;
 786   // The dynamic reloc section.
 787   Reloc_section* rela_dyn_;
 788   // The section to use for IRELATIVE relocs.
 789   Reloc_section* rela_irelative_;
 790   // Relocs saved to avoid a COPY reloc.
 791   Copy_relocs<elfcpp::SHT_RELA, size, false> copy_relocs_;
 792   // Space for variables copied with a COPY reloc.
 793   Output_data_space* dynbss_;
 794   // Offset of the GOT entry for the TLS module index.
 795   unsigned int got_mod_index_offset_;
 796   // We handle R_X86_64_TLSDESC against a local symbol as a target
 797   // specific relocation.  Here we store the object and local symbol
 798   // index for the relocation.
 799   std::vector<Tlsdesc_info> tlsdesc_reloc_info_;
 800   // True if the _TLS_MODULE_BASE_ symbol has been defined.
 801   bool tls_base_symbol_defined_;
 802 };
 803
 804 template<>
 805 const Target::Target_info Target_x86_64<64>::x86_64_info =
 806 {
 807   64,                   // size
 808   false,                // is_big_endian
 809   elfcpp::EM_X86_64,    // machine_code
 810   false,                // has_make_symbol
 811   false,                // has_resolve
 812   true,                 // has_code_fill
 813   true,                 // is_default_stack_executable
 814   true,                 // can_icf_inline_merge_sections
 815   '\0',                 // wrap_char
 816   "/lib/ld64.so.1",     // program interpreter
 817   0x400000,             // default_text_segment_address
 818   0x1000,               // abi_pagesize (overridable by -z max-page-size)
 819   0x1000,               // common_pagesize (overridable by -z common-page-size)
 820   elfcpp::SHN_UNDEF,    // small_common_shndx
 821   elfcpp::SHN_X86_64_LCOMMON,   // large_common_shndx
 822   0,                    // small_common_section_flags
 823   elfcpp::SHF_X86_64_LARGE,     // large_common_section_flags
 824   NULL,                 // attributes_section
 825   NULL                  // attributes_vendor
 826 };
 827
 828 template<>
 829 const Target::Target_info Target_x86_64<32>::x86_64_info =
 830 {
 831   32,                   // size
 832   false,                // is_big_endian
 833   elfcpp::EM_X86_64,    // machine_code
 834   false,                // has_make_symbol
 835   false,                // has_resolve
 836   true,                 // has_code_fill
 837   true,                 // is_default_stack_executable
 838   true,                 // can_icf_inline_merge_sections
 839   '\0',                 // wrap_char
 840   "/libx32/ldx32.so.1", // program interpreter
 841   0x400000,             // default_text_segment_address
 842   0x1000,               // abi_pagesize (overridable by -z max-page-size)
 843   0x1000,               // common_pagesize (overridable by -z common-page-size)
 844   elfcpp::SHN_UNDEF,    // small_common_shndx
 845   elfcpp::SHN_X86_64_LCOMMON,   // large_common_shndx
 846   0,                    // small_common_section_flags
 847   elfcpp::SHF_X86_64_LARGE,     // large_common_section_flags
 848   NULL,                 // attributes_section
 849   NULL                  // attributes_vendor
 850 };
 851
 852 // This is called when a new output section is created.  This is where
 853 // we handle the SHF_X86_64_LARGE.
 854
 855 template<int size>
 856 void
 857 Target_x86_64<size>::do_new_output_section(Output_section* os) const
 858 {
 859   if ((os->flags() & elfcpp::SHF_X86_64_LARGE) != 0)
 860     os->set_is_large_section();
 861 }
 862
 863 // Get the GOT section, creating it if necessary.
 864
 865 template<int size>
 866 Output_data_got<64, false>*
 867 Target_x86_64<size>::got_section(Symbol_table* symtab, Layout* layout)
 868 {
 869   if (this->got_ == NULL)
 870     {
 871       gold_assert(symtab != NULL && layout != NULL);
 872
 873       // When using -z now, we can treat .got.plt as a relro section.
 874       // Without -z now, it is modified after program startup by lazy
 875       // PLT relocations.
 876       bool is_got_plt_relro = parameters->options().now();
 877       Output_section_order got_order = (is_got_plt_relro
 878                                         ? ORDER_RELRO
 879                                         : ORDER_RELRO_LAST);
 880       Output_section_order got_plt_order = (is_got_plt_relro
 881                                             ? ORDER_RELRO
 882                                             : ORDER_NON_RELRO_FIRST);
 883
 884       this->got_ = new Output_data_got<64, false>();
 885
 886       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
 887                                       (elfcpp::SHF_ALLOC
 888                                        | elfcpp::SHF_WRITE),
 889                                       this->got_, got_order, true);
 890
 891       this->got_plt_ = new Output_data_space(8, "** GOT PLT");
 892       layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
 893                                       (elfcpp::SHF_ALLOC
 894                                        | elfcpp::SHF_WRITE),
 895                                       this->got_plt_, got_plt_order,
 896                                       is_got_plt_relro);
 897
 898       // The first three entries are reserved.
 899       this->got_plt_->set_current_data_size(3 * 8);
 900
 901       if (!is_got_plt_relro)
 902         {
 903           // Those bytes can go into the relro segment.
 904           layout->increase_relro(3 * 8);
 905         }
 906
 907       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
 908       this->global_offset_table_ =
 909         symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
 910                                       Symbol_table::PREDEFINED,
 911                                       this->got_plt_,
 912                                       0, 0, elfcpp::STT_OBJECT,
 913                                       elfcpp::STB_LOCAL,
 914                                       elfcpp::STV_HIDDEN, 0,
 915                                       false, false);
 916
 917       // If there are any IRELATIVE relocations, they get GOT entries
 918       // in .got.plt after the jump slot entries.
 919       this->got_irelative_ = new Output_data_space(8, "** GOT IRELATIVE PLT");
 920       layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
 921                                       (elfcpp::SHF_ALLOC
 922                                        | elfcpp::SHF_WRITE),
 923                                       this->got_irelative_,
 924                                       got_plt_order, is_got_plt_relro);
 925
 926       // If there are any TLSDESC relocations, they get GOT entries in
 927       // .got.plt after the jump slot and IRELATIVE entries.
 928       this->got_tlsdesc_ = new Output_data_got<64, false>();
 929       layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
 930                                       (elfcpp::SHF_ALLOC
 931                                        | elfcpp::SHF_WRITE),
 932                                       this->got_tlsdesc_,
 933                                       got_plt_order, is_got_plt_relro);
 934     }
 935
 936   return this->got_;
 937 }
 938
 939 // Get the dynamic reloc section, creating it if necessary.
 940
 941 template<int size>
 942 typename Target_x86_64<size>::Reloc_section*
 943 Target_x86_64<size>::rela_dyn_section(Layout* layout)
 944 {
 945   if (this->rela_dyn_ == NULL)
 946     {
 947       gold_assert(layout != NULL);
 948       this->rela_dyn_ = new Reloc_section(parameters->options().combreloc());
 949       layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
 950                                       elfcpp::SHF_ALLOC, this->rela_dyn_,
 951                                       ORDER_DYNAMIC_RELOCS, false);
 952     }
 953   return this->rela_dyn_;
 954 }
 955
 956 // Get the section to use for IRELATIVE relocs, creating it if
 957 // necessary.  These go in .rela.dyn, but only after all other dynamic
 958 // relocations.  They need to follow the other dynamic relocations so
 959 // that they can refer to global variables initialized by those
 960 // relocs.
 961
 962 template<int size>
 963 typename Target_x86_64<size>::Reloc_section*
 964 Target_x86_64<size>::rela_irelative_section(Layout* layout)
 965 {
 966   if (this->rela_irelative_ == NULL)
 967     {
 968       // Make sure we have already created the dynamic reloc section.
 969       this->rela_dyn_section(layout);
 970       this->rela_irelative_ = new Reloc_section(false);
 971       layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
 972                                       elfcpp::SHF_ALLOC, this->rela_irelative_,
 973                                       ORDER_DYNAMIC_RELOCS, false);
 974       gold_assert(this->rela_dyn_->output_section()
 975                   == this->rela_irelative_->output_section());
 976     }
 977   return this->rela_irelative_;
 978 }
 979
 980 // Initialize the PLT section.
 981
 982 template<int size>
 983 void
 984 Output_data_plt_x86_64<size>::init(Layout* layout)
 985 {
 986   this->rel_ = new Reloc_section(false);
 987   layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
 988                                   elfcpp::SHF_ALLOC, this->rel_,
 989                                   ORDER_DYNAMIC_PLT_RELOCS, false);
 990
 991   // Add unwind information if requested.
 992   if (parameters->options().ld_generated_unwind_info())
 993     layout->add_eh_frame_for_plt(this, plt_eh_frame_cie, plt_eh_frame_cie_size,
 994                                  plt_eh_frame_fde, plt_eh_frame_fde_size);
 995 }
 996
 997 template<int size>
 998 void
 999 Output_data_plt_x86_64<size>::do_adjust_output_section(Output_section* os)
1000 {
1001   os->set_entsize(plt_entry_size);
1002 }
1003
1004 // Add an entry to the PLT.
1005
1006 template<int size>
1007 void
1008 Output_data_plt_x86_64<size>::add_entry(Symbol_table* symtab, Layout* layout,
1009                                         Symbol* gsym)
1010 {
1011   gold_assert(!gsym->has_plt_offset());
1012
1013   unsigned int plt_index;
1014   off_t plt_offset;
1015   section_offset_type got_offset;
1016
1017   unsigned int* pcount;
1018   unsigned int offset;
1019   unsigned int reserved;
1020   Output_data_space* got;
1021   if (gsym->type() == elfcpp::STT_GNU_IFUNC
1022       && gsym->can_use_relative_reloc(false))
1023     {
1024       pcount = &this->irelative_count_;
1025       offset = 0;
1026       reserved = 0;
1027       got = this->got_irelative_;
1028     }
1029   else
1030     {
1031       pcount = &this->count_;
1032       offset = 1;
1033       reserved = 3;
1034       got = this->got_plt_;
1035     }
1036
1037   if (!this->is_data_size_valid())
1038     {
1039       // Note that when setting the PLT offset for a non-IRELATIVE
1040       // entry we skip the initial reserved PLT entry.
1041       plt_index = *pcount + offset;
1042       plt_offset = plt_index * plt_entry_size;
1043
1044       ++*pcount;
1045
1046       got_offset = (plt_index - offset + reserved) * 8;
1047       gold_assert(got_offset == got->current_data_size());
1048
1049       // Every PLT entry needs a GOT entry which points back to the PLT
1050       // entry (this will be changed by the dynamic linker, normally
1051       // lazily when the function is called).
1052       got->set_current_data_size(got_offset + 8);
1053     }
1054   else
1055     {
1056       // FIXME: This is probably not correct for IRELATIVE relocs.
1057
1058       // For incremental updates, find an available slot.
1059       plt_offset = this->free_list_.allocate(plt_entry_size, plt_entry_size, 0);
1060       if (plt_offset == -1)
1061         gold_fallback(_("out of patch space (PLT);"
1062                         " relink with --incremental-full"));
1063
1064       // The GOT and PLT entries have a 1-1 correspondance, so the GOT offset
1065       // can be calculated from the PLT index, adjusting for the three
1066       // reserved entries at the beginning of the GOT.
1067       plt_index = plt_offset / plt_entry_size - 1;
1068       got_offset = (plt_index - offset + reserved) * 8;
1069     }
1070
1071   gsym->set_plt_offset(plt_offset);
1072
1073   // Every PLT entry needs a reloc.
1074   this->add_relocation(symtab, layout, gsym, got_offset);
1075
1076   // Note that we don't need to save the symbol.  The contents of the
1077   // PLT are independent of which symbols are used.  The symbols only
1078   // appear in the relocations.
1079 }
1080
1081 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.  Return
1082 // the PLT offset.
1083
1084 template<int size>
1085 unsigned int
1086 Output_data_plt_x86_64<size>::add_local_ifunc_entry(
1087     Symbol_table* symtab,
1088     Layout* layout,
1089     Sized_relobj_file<size, false>* relobj,
1090     unsigned int local_sym_index)
1091 {
1092   unsigned int plt_offset = this->irelative_count_ * plt_entry_size;
1093   ++this->irelative_count_;
1094
1095   section_offset_type got_offset = this->got_irelative_->current_data_size();
1096
1097   // Every PLT entry needs a GOT entry which points back to the PLT
1098   // entry.
1099   this->got_irelative_->set_current_data_size(got_offset + 8);
1100
1101   // Every PLT entry needs a reloc.
1102   Reloc_section* rela = this->rela_irelative(symtab, layout);
1103   rela->add_symbolless_local_addend(relobj, local_sym_index,
1104                                     elfcpp::R_X86_64_IRELATIVE,
1105                                     this->got_irelative_, got_offset, 0);
1106
1107   return plt_offset;
1108 }
1109
1110 // Add the relocation for a PLT entry.
1111
1112 template<int size>
1113 void
1114 Output_data_plt_x86_64<size>::add_relocation(Symbol_table* symtab,
1115                                              Layout* layout,
1116                                              Symbol* gsym,
1117                                              unsigned int got_offset)
1118 {
1119   if (gsym->type() == elfcpp::STT_GNU_IFUNC
1120       && gsym->can_use_relative_reloc(false))
1121     {
1122       Reloc_section* rela = this->rela_irelative(symtab, layout);
1123       rela->add_symbolless_global_addend(gsym, elfcpp::R_X86_64_IRELATIVE,
1124                                          this->got_irelative_, got_offset, 0);
1125     }
1126   else
1127     {
1128       gsym->set_needs_dynsym_entry();
1129       this->rel_->add_global(gsym, elfcpp::R_X86_64_JUMP_SLOT, this->got_plt_,
1130                              got_offset, 0);
1131     }
1132 }
1133
1134 // Return where the TLSDESC relocations should go, creating it if
1135 // necessary.  These follow the JUMP_SLOT relocations.
1136
1137 template<int size>
1138 typename Output_data_plt_x86_64<size>::Reloc_section*
1139 Output_data_plt_x86_64<size>::rela_tlsdesc(Layout* layout)
1140 {
1141   if (this->tlsdesc_rel_ == NULL)
1142     {
1143       this->tlsdesc_rel_ = new Reloc_section(false);
1144       layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
1145                                       elfcpp::SHF_ALLOC, this->tlsdesc_rel_,
1146                                       ORDER_DYNAMIC_PLT_RELOCS, false);
1147       gold_assert(this->tlsdesc_rel_->output_section()
1148                   == this->rel_->output_section());
1149     }
1150   return this->tlsdesc_rel_;
1151 }
1152
1153 // Return where the IRELATIVE relocations should go in the PLT.  These
1154 // follow the JUMP_SLOT and the TLSDESC relocations.
1155
1156 template<int size>
1157 typename Output_data_plt_x86_64<size>::Reloc_section*
1158 Output_data_plt_x86_64<size>::rela_irelative(Symbol_table* symtab,
1159                                              Layout* layout)
1160 {
1161   if (this->irelative_rel_ == NULL)
1162     {
1163       // Make sure we have a place for the TLSDESC relocations, in
1164       // case we see any later on.
1165       this->rela_tlsdesc(layout);
1166       this->irelative_rel_ = new Reloc_section(false);
1167       layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
1168                                       elfcpp::SHF_ALLOC, this->irelative_rel_,
1169                                       ORDER_DYNAMIC_PLT_RELOCS, false);
1170       gold_assert(this->irelative_rel_->output_section()
1171                   == this->rel_->output_section());
1172
1173       if (parameters->doing_static_link())
1174         {
1175           // A statically linked executable will only have a .rela.plt
1176           // section to hold R_X86_64_IRELATIVE relocs for
1177           // STT_GNU_IFUNC symbols.  The library will use these
1178           // symbols to locate the IRELATIVE relocs at program startup
1179           // time.
1180           symtab->define_in_output_data("__rela_iplt_start", NULL,
1181                                         Symbol_table::PREDEFINED,
1182                                         this->irelative_rel_, 0, 0,
1183                                         elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1184                                         elfcpp::STV_HIDDEN, 0, false, true);
1185           symtab->define_in_output_data("__rela_iplt_end", NULL,
1186                                         Symbol_table::PREDEFINED,
1187                                         this->irelative_rel_, 0, 0,
1188                                         elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1189                                         elfcpp::STV_HIDDEN, 0, true, true);
1190         }
1191     }
1192   return this->irelative_rel_;
1193 }
1194
1195 // Return the PLT address to use for a global symbol.
1196
1197 template<int size>
1198 uint64_t
1199 Output_data_plt_x86_64<size>::address_for_global(const Symbol* gsym)
1200 {
1201   uint64_t offset = 0;
1202   if (gsym->type() == elfcpp::STT_GNU_IFUNC
1203       && gsym->can_use_relative_reloc(false))
1204     offset = (this->count_ + 1) * plt_entry_size;
1205   return this->address() + offset;
1206 }
1207
1208 // Return the PLT address to use for a local symbol.  These are always
1209 // IRELATIVE relocs.
1210
1211 template<int size>
1212 uint64_t
1213 Output_data_plt_x86_64<size>::address_for_local(const Relobj*, unsigned int)
1214 {
1215   return this->address() + (this->count_ + 1) * plt_entry_size;
1216 }
1217
1218 // Set the final size.
1219 template<int size>
1220 void
1221 Output_data_plt_x86_64<size>::set_final_data_size()
1222 {
1223   unsigned int count = this->count_ + this->irelative_count_;
1224   if (this->has_tlsdesc_entry())
1225     ++count;
1226   this->set_data_size((count + 1) * plt_entry_size);
1227 }
1228
1229 // The first entry in the PLT for an executable.
1230
1231 template<int size>
1232 const unsigned char
1233 Output_data_plt_x86_64<size>::first_plt_entry[plt_entry_size] =
1234 {
1235   // From AMD64 ABI Draft 0.98, page 76
1236   0xff, 0x35,   // pushq contents of memory address
1237   0, 0, 0, 0,   // replaced with address of .got + 8
1238   0xff, 0x25,   // jmp indirect
1239   0, 0, 0, 0,   // replaced with address of .got + 16
1240   0x90, 0x90, 0x90, 0x90   // noop (x4)
1241 };
1242
1243 // Subsequent entries in the PLT for an executable.
1244
1245 template<int size>
1246 const unsigned char
1247 Output_data_plt_x86_64<size>::plt_entry[plt_entry_size] =
1248 {
1249   // From AMD64 ABI Draft 0.98, page 76
1250   0xff, 0x25,   // jmpq indirect
1251   0, 0, 0, 0,   // replaced with address of symbol in .got
1252   0x68,         // pushq immediate
1253   0, 0, 0, 0,   // replaced with offset into relocation table
1254   0xe9,         // jmpq relative
1255   0, 0, 0, 0    // replaced with offset to start of .plt
1256 };
1257
1258 // The reserved TLSDESC entry in the PLT for an executable.
1259
1260 template<int size>
1261 const unsigned char
1262 Output_data_plt_x86_64<size>::tlsdesc_plt_entry[plt_entry_size] =
1263 {
1264   // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
1265   // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
1266   0xff, 0x35,   // pushq x(%rip)
1267   0, 0, 0, 0,   // replaced with address of linkmap GOT entry (at PLTGOT + 8)
1268   0xff, 0x25,   // jmpq *y(%rip)
1269   0, 0, 0, 0,   // replaced with offset of reserved TLSDESC_GOT entry
1270   0x0f, 0x1f,   // nop
1271   0x40, 0
1272 };
1273
1274 // The .eh_frame unwind information for the PLT.
1275
1276 template<int size>
1277 const unsigned char
1278 Output_data_plt_x86_64<size>::plt_eh_frame_cie[plt_eh_frame_cie_size] =
1279 {
1280   1,                            // CIE version.
1281   'z',                          // Augmentation: augmentation size included.
1282   'R',                          // Augmentation: FDE encoding included.
1283   '\0',                         // End of augmentation string.
1284   1,                            // Code alignment factor.
1285   0x78,                         // Data alignment factor.
1286   16,                           // Return address column.
1287   1,                            // Augmentation size.
1288   (elfcpp::DW_EH_PE_pcrel       // FDE encoding.
1289    | elfcpp::DW_EH_PE_sdata4),
1290   elfcpp::DW_CFA_def_cfa, 7, 8, // DW_CFA_def_cfa: r7 (rsp) ofs 8.
1291   elfcpp::DW_CFA_offset + 16, 1,// DW_CFA_offset: r16 (rip) at cfa-8.
1292   elfcpp::DW_CFA_nop,           // Align to 16 bytes.
1293   elfcpp::DW_CFA_nop
1294 };
1295
1296 template<int size>
1297 const unsigned char
1298 Output_data_plt_x86_64<size>::plt_eh_frame_fde[plt_eh_frame_fde_size] =
1299 {
1300   0, 0, 0, 0,                           // Replaced with offset to .plt.
1301   0, 0, 0, 0,                           // Replaced with size of .plt.
1302   0,                                    // Augmentation size.
1303   elfcpp::DW_CFA_def_cfa_offset, 16,    // DW_CFA_def_cfa_offset: 16.
1304   elfcpp::DW_CFA_advance_loc + 6,       // Advance 6 to __PLT__ + 6.
1305   elfcpp::DW_CFA_def_cfa_offset, 24,    // DW_CFA_def_cfa_offset: 24.
1306   elfcpp::DW_CFA_advance_loc + 10,      // Advance 10 to __PLT__ + 16.
1307   elfcpp::DW_CFA_def_cfa_expression,    // DW_CFA_def_cfa_expression.
1308   11,                                   // Block length.
1309   elfcpp::DW_OP_breg7, 8,               // Push %rsp + 8.
1310   elfcpp::DW_OP_breg16, 0,              // Push %rip.
1311   elfcpp::DW_OP_lit15,                  // Push 0xf.
1312   elfcpp::DW_OP_and,                    // & (%rip & 0xf).
1313   elfcpp::DW_OP_lit11,                  // Push 0xb.
1314   elfcpp::DW_OP_ge,                     // >= ((%rip & 0xf) >= 0xb)
1315   elfcpp::DW_OP_lit3,                   // Push 3.
1316   elfcpp::DW_OP_shl,                    // << (((%rip & 0xf) >= 0xb) << 3)
1317   elfcpp::DW_OP_plus,                   // + ((((%rip&0xf)>=0xb)<<3)+%rsp+8
1318   elfcpp::DW_CFA_nop,                   // Align to 32 bytes.
1319   elfcpp::DW_CFA_nop,
1320   elfcpp::DW_CFA_nop,
1321   elfcpp::DW_CFA_nop
1322 };
1323
1324 // Write out the PLT.  This uses the hand-coded instructions above,
1325 // and adjusts them as needed.  This is specified by the AMD64 ABI.
1326
1327 template<int size>
1328 void
1329 Output_data_plt_x86_64<size>::do_write(Output_file* of)
1330 {
1331   const off_t offset = this->offset();
1332   const section_size_type oview_size =
1333     convert_to_section_size_type(this->data_size());
1334   unsigned char* const oview = of->get_output_view(offset, oview_size);
1335
1336   const off_t got_file_offset = this->got_plt_->offset();
1337   gold_assert(parameters->incremental_update()
1338               || (got_file_offset + this->got_plt_->data_size()
1339                   == this->got_irelative_->offset()));
1340   const section_size_type got_size =
1341     convert_to_section_size_type(this->got_plt_->data_size()
1342                                  + this->got_irelative_->data_size());
1343   unsigned char* const got_view = of->get_output_view(got_file_offset,
1344                                                       got_size);
1345
1346   unsigned char* pov = oview;
1347
1348   // The base address of the .plt section.
1349   typename elfcpp::Elf_types<size>::Elf_Addr plt_address = this->address();
1350   // The base address of the .got section.
1351   typename elfcpp::Elf_types<size>::Elf_Addr got_base = this->got_->address();
1352   // The base address of the PLT portion of the .got section,
1353   // which is where the GOT pointer will point, and where the
1354   // three reserved GOT entries are located.
1355   typename elfcpp::Elf_types<size>::Elf_Addr got_address
1356     = this->got_plt_->address();
1357
1358   memcpy(pov, first_plt_entry, plt_entry_size);
1359   // We do a jmp relative to the PC at the end of this instruction.
1360   elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1361                                               (got_address + 8
1362                                                - (plt_address + 6)));
1363   elfcpp::Swap<32, false>::writeval(pov + 8,
1364                                     (got_address + 16
1365                                      - (plt_address + 12)));
1366   pov += plt_entry_size;
1367
1368   unsigned char* got_pov = got_view;
1369
1370   // The first entry in the GOT is the address of the .dynamic section
1371   // aka the PT_DYNAMIC segment.  The next two entries are reserved.
1372   // We saved space for them when we created the section in
1373   // Target_x86_64::got_section.
1374   Output_section* dynamic = this->layout_->dynamic_section();
1375   uint32_t dynamic_addr = dynamic == NULL ? 0 : dynamic->address();
1376   elfcpp::Swap<64, false>::writeval(got_pov, dynamic_addr);
1377   got_pov += 8;
1378   memset(got_pov, 0, 16);
1379   got_pov += 16;
1380
1381   unsigned int plt_offset = plt_entry_size;
1382   unsigned int got_offset = 24;
1383   const unsigned int count = this->count_ + this->irelative_count_;
1384   for (unsigned int plt_index = 0;
1385        plt_index < count;
1386        ++plt_index,
1387          pov += plt_entry_size,
1388          got_pov += 8,
1389          plt_offset += plt_entry_size,
1390          got_offset += 8)
1391     {
1392       // Set and adjust the PLT entry itself.
1393       memcpy(pov, plt_entry, plt_entry_size);
1394       elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1395                                                   (got_address + got_offset
1396                                                    - (plt_address + plt_offset
1397                                                       + 6)));
1398
1399       elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_index);
1400       elfcpp::Swap<32, false>::writeval(pov + 12,
1401                                         - (plt_offset + plt_entry_size));
1402
1403       // Set the entry in the GOT.
1404       elfcpp::Swap<64, false>::writeval(got_pov, plt_address + plt_offset + 6);
1405     }
1406
1407   if (this->has_tlsdesc_entry())
1408     {
1409       // Set and adjust the reserved TLSDESC PLT entry.
1410       unsigned int tlsdesc_got_offset = this->get_tlsdesc_got_offset();
1411       memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
1412       elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1413                                                   (got_address + 8
1414                                                    - (plt_address + plt_offset
1415                                                       + 6)));
1416       elfcpp::Swap_unaligned<32, false>::writeval(pov + 8,
1417                                                   (got_base
1418                                                    + tlsdesc_got_offset
1419                                                    - (plt_address + plt_offset
1420                                                       + 12)));
1421       pov += plt_entry_size;
1422     }
1423
1424   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
1425   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
1426
1427   of->write_output_view(offset, oview_size, oview);
1428   of->write_output_view(got_file_offset, got_size, got_view);
1429 }
1430
1431 // Create the PLT section.
1432
1433 template<int size>
1434 void
1435 Target_x86_64<size>::make_plt_section(Symbol_table* symtab, Layout* layout)
1436 {
1437   if (this->plt_ == NULL)
1438     {
1439       // Create the GOT sections first.
1440       this->got_section(symtab, layout);
1441
1442       this->plt_ = new Output_data_plt_x86_64<size>(layout, this->got_,
1443                                                     this->got_plt_,
1444                                                     this->got_irelative_);
1445       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
1446                                       (elfcpp::SHF_ALLOC
1447                                        | elfcpp::SHF_EXECINSTR),
1448                                       this->plt_, ORDER_PLT, false);
1449
1450       // Make the sh_info field of .rela.plt point to .plt.
1451       Output_section* rela_plt_os = this->plt_->rela_plt()->output_section();
1452       rela_plt_os->set_info_section(this->plt_->output_section());
1453     }
1454 }
1455
1456 // Return the section for TLSDESC relocations.
1457
1458 template<int size>
1459 typename Target_x86_64<size>::Reloc_section*
1460 Target_x86_64<size>::rela_tlsdesc_section(Layout* layout) const
1461 {
1462   return this->plt_section()->rela_tlsdesc(layout);
1463 }
1464
1465 // Create a PLT entry for a global symbol.
1466
1467 template<int size>
1468 void
1469 Target_x86_64<size>::make_plt_entry(Symbol_table* symtab, Layout* layout,
1470                                     Symbol* gsym)
1471 {
1472   if (gsym->has_plt_offset())
1473     return;
1474
1475   if (this->plt_ == NULL)
1476     this->make_plt_section(symtab, layout);
1477
1478   this->plt_->add_entry(symtab, layout, gsym);
1479 }
1480
1481 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1482
1483 template<int size>
1484 void
1485 Target_x86_64<size>::make_local_ifunc_plt_entry(
1486     Symbol_table* symtab, Layout* layout,
1487     Sized_relobj_file<size, false>* relobj,
1488     unsigned int local_sym_index)
1489 {
1490   if (relobj->local_has_plt_offset(local_sym_index))
1491     return;
1492   if (this->plt_ == NULL)
1493     this->make_plt_section(symtab, layout);
1494   unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout,
1495                                                               relobj,
1496                                                               local_sym_index);
1497   relobj->set_local_plt_offset(local_sym_index, plt_offset);
1498 }
1499
1500 // Return the number of entries in the PLT.
1501
1502 template<int size>
1503 unsigned int
1504 Target_x86_64<size>::plt_entry_count() const
1505 {
1506   if (this->plt_ == NULL)
1507     return 0;
1508   return this->plt_->entry_count();
1509 }
1510
1511 // Return the offset of the first non-reserved PLT entry.
1512
1513 template<int size>
1514 unsigned int
1515 Target_x86_64<size>::first_plt_entry_offset() const
1516 {
1517   return Output_data_plt_x86_64<size>::first_plt_entry_offset();
1518 }
1519
1520 // Return the size of each PLT entry.
1521
1522 template<int size>
1523 unsigned int
1524 Target_x86_64<size>::plt_entry_size() const
1525 {
1526   return Output_data_plt_x86_64<size>::get_plt_entry_size();
1527 }
1528
1529 // Create the GOT and PLT sections for an incremental update.
1530
1531 template<int size>
1532 Output_data_got_base*
1533 Target_x86_64<size>::init_got_plt_for_update(Symbol_table* symtab,
1534                                        Layout* layout,
1535                                        unsigned int got_count,
1536                                        unsigned int plt_count)
1537 {
1538   gold_assert(this->got_ == NULL);
1539
1540   this->got_ = new Output_data_got<64, false>(got_count * 8);
1541   layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
1542                                   (elfcpp::SHF_ALLOC
1543                                    | elfcpp::SHF_WRITE),
1544                                   this->got_, ORDER_RELRO_LAST,
1545                                   true);
1546
1547   // Add the three reserved entries.
1548   this->got_plt_ = new Output_data_space((plt_count + 3) * 8, 8, "** GOT PLT");
1549   layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1550                                   (elfcpp::SHF_ALLOC
1551                                    | elfcpp::SHF_WRITE),
1552                                   this->got_plt_, ORDER_NON_RELRO_FIRST,
1553                                   false);
1554
1555   // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
1556   this->global_offset_table_ =
1557     symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
1558                                   Symbol_table::PREDEFINED,
1559                                   this->got_plt_,
1560                                   0, 0, elfcpp::STT_OBJECT,
1561                                   elfcpp::STB_LOCAL,
1562                                   elfcpp::STV_HIDDEN, 0,
1563                                   false, false);
1564
1565   // If there are any TLSDESC relocations, they get GOT entries in
1566   // .got.plt after the jump slot entries.
1567   // FIXME: Get the count for TLSDESC entries.
1568   this->got_tlsdesc_ = new Output_data_got<64, false>(0);
1569   layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1570                                   elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
1571                                   this->got_tlsdesc_,
1572                                   ORDER_NON_RELRO_FIRST, false);
1573
1574   // If there are any IRELATIVE relocations, they get GOT entries in
1575   // .got.plt after the jump slot and TLSDESC entries.
1576   this->got_irelative_ = new Output_data_space(0, 8, "** GOT IRELATIVE PLT");
1577   layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1578                                   elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
1579                                   this->got_irelative_,
1580                                   ORDER_NON_RELRO_FIRST, false);
1581
1582   // Create the PLT section.
1583   this->plt_ = new Output_data_plt_x86_64<size>(layout, this->got_,
1584                                                 this->got_plt_,
1585                                                 this->got_irelative_,
1586                                                 plt_count);
1587   layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
1588                                   elfcpp::SHF_ALLOC | elfcpp::SHF_EXECINSTR,
1589                                   this->plt_, ORDER_PLT, false);
1590
1591   // Make the sh_info field of .rela.plt point to .plt.
1592   Output_section* rela_plt_os = this->plt_->rela_plt()->output_section();
1593   rela_plt_os->set_info_section(this->plt_->output_section());
1594
1595   // Create the rela_dyn section.
1596   this->rela_dyn_section(layout);
1597
1598   return this->got_;
1599 }
1600
1601 // Reserve a GOT entry for a local symbol, and regenerate any
1602 // necessary dynamic relocations.
1603
1604 template<int size>
1605 void
1606 Target_x86_64<size>::reserve_local_got_entry(
1607     unsigned int got_index,
1608     Sized_relobj<size, false>* obj,
1609     unsigned int r_sym,
1610     unsigned int got_type)
1611 {
1612   unsigned int got_offset = got_index * 8;
1613   Reloc_section* rela_dyn = this->rela_dyn_section(NULL);
1614
1615   this->got_->reserve_local(got_index, obj, r_sym, got_type);
1616   switch (got_type)
1617     {
1618     case GOT_TYPE_STANDARD:
1619       if (parameters->options().output_is_position_independent())
1620         rela_dyn->add_local_relative(obj, r_sym, elfcpp::R_X86_64_RELATIVE,
1621                                      this->got_, got_offset, 0, false);
1622       break;
1623     case GOT_TYPE_TLS_OFFSET:
1624       rela_dyn->add_local(obj, r_sym, elfcpp::R_X86_64_TPOFF64,
1625                           this->got_, got_offset, 0);
1626       break;
1627     case GOT_TYPE_TLS_PAIR:
1628       this->got_->reserve_slot(got_index + 1);
1629       rela_dyn->add_local(obj, r_sym, elfcpp::R_X86_64_DTPMOD64,
1630                           this->got_, got_offset, 0);
1631       break;
1632     case GOT_TYPE_TLS_DESC:
1633       gold_fatal(_("TLS_DESC not yet supported for incremental linking"));
1634       // this->got_->reserve_slot(got_index + 1);
1635       // rela_dyn->add_target_specific(elfcpp::R_X86_64_TLSDESC, arg,
1636       //                               this->got_, got_offset, 0);
1637       break;
1638     default:
1639       gold_unreachable();
1640     }
1641 }
1642
1643 // Reserve a GOT entry for a global symbol, and regenerate any
1644 // necessary dynamic relocations.
1645
1646 template<int size>
1647 void
1648 Target_x86_64<size>::reserve_global_got_entry(unsigned int got_index,
1649                                               Symbol* gsym,
1650                                               unsigned int got_type)
1651 {
1652   unsigned int got_offset = got_index * 8;
1653   Reloc_section* rela_dyn = this->rela_dyn_section(NULL);
1654
1655   this->got_->reserve_global(got_index, gsym, got_type);
1656   switch (got_type)
1657     {
1658     case GOT_TYPE_STANDARD:
1659       if (!gsym->final_value_is_known())
1660         {
1661           if (gsym->is_from_dynobj()
1662               || gsym->is_undefined()
1663               || gsym->is_preemptible()
1664               || gsym->type() == elfcpp::STT_GNU_IFUNC)
1665             rela_dyn->add_global(gsym, elfcpp::R_X86_64_GLOB_DAT,
1666                                  this->got_, got_offset, 0);
1667           else
1668             rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_RELATIVE,
1669                                           this->got_, got_offset, 0);
1670         }
1671       break;
1672     case GOT_TYPE_TLS_OFFSET:
1673       rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_TPOFF64,
1674                                     this->got_, got_offset, 0);
1675       break;
1676     case GOT_TYPE_TLS_PAIR:
1677       this->got_->reserve_slot(got_index + 1);
1678       rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_DTPMOD64,
1679                                     this->got_, got_offset, 0);
1680       rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_DTPOFF64,
1681                                     this->got_, got_offset + 8, 0);
1682       break;
1683     case GOT_TYPE_TLS_DESC:
1684       this->got_->reserve_slot(got_index + 1);
1685       rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_TLSDESC,
1686                                     this->got_, got_offset, 0);
1687       break;
1688     default:
1689       gold_unreachable();
1690     }
1691 }
1692
1693 // Register an existing PLT entry for a global symbol.
1694
1695 template<int size>
1696 void
1697 Target_x86_64<size>::register_global_plt_entry(Symbol_table* symtab,
1698                                                Layout* layout,
1699                                                unsigned int plt_index,
1700                                                Symbol* gsym)
1701 {
1702   gold_assert(this->plt_ != NULL);
1703   gold_assert(!gsym->has_plt_offset());
1704
1705   this->plt_->reserve_slot(plt_index);
1706
1707   gsym->set_plt_offset((plt_index + 1) * this->plt_entry_size());
1708
1709   unsigned int got_offset = (plt_index + 3) * 8;
1710   this->plt_->add_relocation(symtab, layout, gsym, got_offset);
1711 }
1712
1713 // Force a COPY relocation for a given symbol.
1714
1715 template<int size>
1716 void
1717 Target_x86_64<size>::emit_copy_reloc(
1718     Symbol_table* symtab, Symbol* sym, Output_section* os, off_t offset)
1719 {
1720   this->copy_relocs_.emit_copy_reloc(symtab,
1721                                      symtab->get_sized_symbol<size>(sym),
1722                                      os,
1723                                      offset,
1724                                      this->rela_dyn_section(NULL));
1725 }
1726
1727 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1728
1729 template<int size>
1730 void
1731 Target_x86_64<size>::define_tls_base_symbol(Symbol_table* symtab,
1732                                             Layout* layout)
1733 {
1734   if (this->tls_base_symbol_defined_)
1735     return;
1736
1737   Output_segment* tls_segment = layout->tls_segment();
1738   if (tls_segment != NULL)
1739     {
1740       bool is_exec = parameters->options().output_is_executable();
1741       symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
1742                                        Symbol_table::PREDEFINED,
1743                                        tls_segment, 0, 0,
1744                                        elfcpp::STT_TLS,
1745                                        elfcpp::STB_LOCAL,
1746                                        elfcpp::STV_HIDDEN, 0,
1747                                        (is_exec
1748                                         ? Symbol::SEGMENT_END
1749                                         : Symbol::SEGMENT_START),
1750                                        true);
1751     }
1752   this->tls_base_symbol_defined_ = true;
1753 }
1754
1755 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
1756
1757 template<int size>
1758 void
1759 Target_x86_64<size>::reserve_tlsdesc_entries(Symbol_table* symtab,
1760                                              Layout* layout)
1761 {
1762   if (this->plt_ == NULL)
1763     this->make_plt_section(symtab, layout);
1764
1765   if (!this->plt_->has_tlsdesc_entry())
1766     {
1767       // Allocate the TLSDESC_GOT entry.
1768       Output_data_got<64, false>* got = this->got_section(symtab, layout);
1769       unsigned int got_offset = got->add_constant(0);
1770
1771       // Allocate the TLSDESC_PLT entry.
1772       this->plt_->reserve_tlsdesc_entry(got_offset);
1773     }
1774 }
1775
1776 // Create a GOT entry for the TLS module index.
1777
1778 template<int size>
1779 unsigned int
1780 Target_x86_64<size>::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
1781                                          Sized_relobj_file<size, false>* object)
1782 {
1783   if (this->got_mod_index_offset_ == -1U)
1784     {
1785       gold_assert(symtab != NULL && layout != NULL && object != NULL);
1786       Reloc_section* rela_dyn = this->rela_dyn_section(layout);
1787       Output_data_got<64, false>* got = this->got_section(symtab, layout);
1788       unsigned int got_offset = got->add_constant(0);
1789       rela_dyn->add_local(object, 0, elfcpp::R_X86_64_DTPMOD64, got,
1790                           got_offset, 0);
1791       got->add_constant(0);
1792       this->got_mod_index_offset_ = got_offset;
1793     }
1794   return this->got_mod_index_offset_;
1795 }
1796
1797 // Optimize the TLS relocation type based on what we know about the
1798 // symbol.  IS_FINAL is true if the final address of this symbol is
1799 // known at link time.
1800
1801 template<int size>
1802 tls::Tls_optimization
1803 Target_x86_64<size>::optimize_tls_reloc(bool is_final, int r_type)
1804 {
1805   // If we are generating a shared library, then we can't do anything
1806   // in the linker.
1807   if (parameters->options().shared())
1808     return tls::TLSOPT_NONE;
1809
1810   switch (r_type)
1811     {
1812     case elfcpp::R_X86_64_TLSGD:
1813     case elfcpp::R_X86_64_GOTPC32_TLSDESC:
1814     case elfcpp::R_X86_64_TLSDESC_CALL:
1815       // These are General-Dynamic which permits fully general TLS
1816       // access.  Since we know that we are generating an executable,
1817       // we can convert this to Initial-Exec.  If we also know that
1818       // this is a local symbol, we can further switch to Local-Exec.
1819       if (is_final)
1820         return tls::TLSOPT_TO_LE;
1821       return tls::TLSOPT_TO_IE;
1822
1823     case elfcpp::R_X86_64_TLSLD:
1824       // This is Local-Dynamic, which refers to a local symbol in the
1825       // dynamic TLS block.  Since we know that we generating an
1826       // executable, we can switch to Local-Exec.
1827       return tls::TLSOPT_TO_LE;
1828
1829     case elfcpp::R_X86_64_DTPOFF32:
1830     case elfcpp::R_X86_64_DTPOFF64:
1831       // Another Local-Dynamic reloc.
1832       return tls::TLSOPT_TO_LE;
1833
1834     case elfcpp::R_X86_64_GOTTPOFF:
1835       // These are Initial-Exec relocs which get the thread offset
1836       // from the GOT.  If we know that we are linking against the
1837       // local symbol, we can switch to Local-Exec, which links the
1838       // thread offset into the instruction.
1839       if (is_final)
1840         return tls::TLSOPT_TO_LE;
1841       return tls::TLSOPT_NONE;
1842
1843     case elfcpp::R_X86_64_TPOFF32:
1844       // When we already have Local-Exec, there is nothing further we
1845       // can do.
1846       return tls::TLSOPT_NONE;
1847
1848     default:
1849       gold_unreachable();
1850     }
1851 }
1852
1853 // Get the Reference_flags for a particular relocation.
1854
1855 template<int size>
1856 int
1857 Target_x86_64<size>::Scan::get_reference_flags(unsigned int r_type)
1858 {
1859   switch (r_type)
1860     {
1861     case elfcpp::R_X86_64_NONE:
1862     case elfcpp::R_X86_64_GNU_VTINHERIT:
1863     case elfcpp::R_X86_64_GNU_VTENTRY:
1864     case elfcpp::R_X86_64_GOTPC32:
1865     case elfcpp::R_X86_64_GOTPC64:
1866       // No symbol reference.
1867       return 0;
1868
1869     case elfcpp::R_X86_64_64:
1870     case elfcpp::R_X86_64_32:
1871     case elfcpp::R_X86_64_32S:
1872     case elfcpp::R_X86_64_16:
1873     case elfcpp::R_X86_64_8:
1874       return Symbol::ABSOLUTE_REF;
1875
1876     case elfcpp::R_X86_64_PC64:
1877     case elfcpp::R_X86_64_PC32:
1878     case elfcpp::R_X86_64_PC16:
1879     case elfcpp::R_X86_64_PC8:
1880     case elfcpp::R_X86_64_GOTOFF64:
1881       return Symbol::RELATIVE_REF;
1882
1883     case elfcpp::R_X86_64_PLT32:
1884     case elfcpp::R_X86_64_PLTOFF64:
1885       return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
1886
1887     case elfcpp::R_X86_64_GOT64:
1888     case elfcpp::R_X86_64_GOT32:
1889     case elfcpp::R_X86_64_GOTPCREL64:
1890     case elfcpp::R_X86_64_GOTPCREL:
1891     case elfcpp::R_X86_64_GOTPLT64:
1892       // Absolute in GOT.
1893       return Symbol::ABSOLUTE_REF;
1894
1895     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
1896     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
1897     case elfcpp::R_X86_64_TLSDESC_CALL:
1898     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
1899     case elfcpp::R_X86_64_DTPOFF32:
1900     case elfcpp::R_X86_64_DTPOFF64:
1901     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
1902     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
1903       return Symbol::TLS_REF;
1904
1905     case elfcpp::R_X86_64_COPY:
1906     case elfcpp::R_X86_64_GLOB_DAT:
1907     case elfcpp::R_X86_64_JUMP_SLOT:
1908     case elfcpp::R_X86_64_RELATIVE:
1909     case elfcpp::R_X86_64_IRELATIVE:
1910     case elfcpp::R_X86_64_TPOFF64:
1911     case elfcpp::R_X86_64_DTPMOD64:
1912     case elfcpp::R_X86_64_TLSDESC:
1913     case elfcpp::R_X86_64_SIZE32:
1914     case elfcpp::R_X86_64_SIZE64:
1915     default:
1916       // Not expected.  We will give an error later.
1917       return 0;
1918     }
1919 }
1920
1921 // Report an unsupported relocation against a local symbol.
1922
1923 template<int size>
1924 void
1925 Target_x86_64<size>::Scan::unsupported_reloc_local(
1926      Sized_relobj_file<size, false>* object,
1927      unsigned int r_type)
1928 {
1929   gold_error(_("%s: unsupported reloc %u against local symbol"),
1930              object->name().c_str(), r_type);
1931 }
1932
1933 // We are about to emit a dynamic relocation of type R_TYPE.  If the
1934 // dynamic linker does not support it, issue an error.  The GNU linker
1935 // only issues a non-PIC error for an allocated read-only section.
1936 // Here we know the section is allocated, but we don't know that it is
1937 // read-only.  But we check for all the relocation types which the
1938 // glibc dynamic linker supports, so it seems appropriate to issue an
1939 // error even if the section is not read-only.  If GSYM is not NULL,
1940 // it is the symbol the relocation is against; if it is NULL, the
1941 // relocation is against a local symbol.
1942
1943 template<int size>
1944 void
1945 Target_x86_64<size>::Scan::check_non_pic(Relobj* object, unsigned int r_type,
1946                                          Symbol* gsym)
1947 {
1948   switch (r_type)
1949     {
1950       // These are the relocation types supported by glibc for x86_64
1951       // which should always work.
1952     case elfcpp::R_X86_64_RELATIVE:
1953     case elfcpp::R_X86_64_IRELATIVE:
1954     case elfcpp::R_X86_64_GLOB_DAT:
1955     case elfcpp::R_X86_64_JUMP_SLOT:
1956     case elfcpp::R_X86_64_DTPMOD64:
1957     case elfcpp::R_X86_64_DTPOFF64:
1958     case elfcpp::R_X86_64_TPOFF64:
1959     case elfcpp::R_X86_64_64:
1960     case elfcpp::R_X86_64_COPY:
1961       return;
1962
1963       // glibc supports these reloc types, but they can overflow.
1964     case elfcpp::R_X86_64_PC32:
1965       // A PC relative reference is OK against a local symbol or if
1966       // the symbol is defined locally.
1967       if (gsym == NULL
1968           || (!gsym->is_from_dynobj()
1969               && !gsym->is_undefined()
1970               && !gsym->is_preemptible()))
1971         return;
1972       /* Fall through.  */
1973     case elfcpp::R_X86_64_32:
1974       // R_X86_64_32 is OK for x32.
1975       if (size == 32 && r_type == elfcpp::R_X86_64_32)
1976         return;
1977       if (this->issued_non_pic_error_)
1978         return;
1979       gold_assert(parameters->options().output_is_position_independent());
1980       if (gsym == NULL)
1981         object->error(_("requires dynamic R_X86_64_32 reloc which may "
1982                         "overflow at runtime; recompile with -fPIC"));
1983       else
1984         object->error(_("requires dynamic %s reloc against '%s' which may "
1985                         "overflow at runtime; recompile with -fPIC"),
1986                       (r_type == elfcpp::R_X86_64_32
1987                        ? "R_X86_64_32"
1988                        : "R_X86_64_PC32"),
1989                       gsym->name());
1990       this->issued_non_pic_error_ = true;
1991       return;
1992
1993     default:
1994       // This prevents us from issuing more than one error per reloc
1995       // section.  But we can still wind up issuing more than one
1996       // error per object file.
1997       if (this->issued_non_pic_error_)
1998         return;
1999       gold_assert(parameters->options().output_is_position_independent());
2000       object->error(_("requires unsupported dynamic reloc %u; "
2001                       "recompile with -fPIC"),
2002                     r_type);
2003       this->issued_non_pic_error_ = true;
2004       return;
2005
2006     case elfcpp::R_X86_64_NONE:
2007       gold_unreachable();
2008     }
2009 }
2010
2011 // Return whether we need to make a PLT entry for a relocation of the
2012 // given type against a STT_GNU_IFUNC symbol.
2013
2014 template<int size>
2015 bool
2016 Target_x86_64<size>::Scan::reloc_needs_plt_for_ifunc(
2017      Sized_relobj_file<size, false>* object,
2018      unsigned int r_type)
2019 {
2020   int flags = Scan::get_reference_flags(r_type);
2021   if (flags & Symbol::TLS_REF)
2022     gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
2023                object->name().c_str(), r_type);
2024   return flags != 0;
2025 }
2026
2027 // Scan a relocation for a local symbol.
2028
2029 template<int size>
2030 inline void
2031 Target_x86_64<size>::Scan::local(Symbol_table* symtab,
2032                                  Layout* layout,
2033                                  Target_x86_64<size>* target,
2034                                  Sized_relobj_file<size, false>* object,
2035                                  unsigned int data_shndx,
2036                                  Output_section* output_section,
2037                                  const elfcpp::Rela<size, false>& reloc,
2038                                  unsigned int r_type,
2039                                  const elfcpp::Sym<size, false>& lsym)
2040 {
2041   // A local STT_GNU_IFUNC symbol may require a PLT entry.
2042   bool is_ifunc = lsym.get_st_type() == elfcpp::STT_GNU_IFUNC;
2043   if (is_ifunc && this->reloc_needs_plt_for_ifunc(object, r_type))
2044     {
2045       unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2046       target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
2047     }
2048
2049   switch (r_type)
2050     {
2051     case elfcpp::R_X86_64_NONE:
2052     case elfcpp::R_X86_64_GNU_VTINHERIT:
2053     case elfcpp::R_X86_64_GNU_VTENTRY:
2054       break;
2055
2056     case elfcpp::R_X86_64_64:
2057       // If building a shared library (or a position-independent
2058       // executable), we need to create a dynamic relocation for this
2059       // location.  The relocation applied at link time will apply the
2060       // link-time value, so we flag the location with an
2061       // R_X86_64_RELATIVE relocation so the dynamic loader can
2062       // relocate it easily.
2063       if (parameters->options().output_is_position_independent())
2064         {
2065           unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2066           Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2067           rela_dyn->add_local_relative(object, r_sym,
2068                                        elfcpp::R_X86_64_RELATIVE,
2069                                        output_section, data_shndx,
2070                                        reloc.get_r_offset(),
2071                                        reloc.get_r_addend(), is_ifunc);
2072         }
2073       break;
2074
2075     case elfcpp::R_X86_64_32:
2076     case elfcpp::R_X86_64_32S:
2077     case elfcpp::R_X86_64_16:
2078     case elfcpp::R_X86_64_8:
2079       // If building a shared library (or a position-independent
2080       // executable), we need to create a dynamic relocation for this
2081       // location.  We can't use an R_X86_64_RELATIVE relocation
2082       // because that is always a 64-bit relocation.
2083       if (parameters->options().output_is_position_independent())
2084         {
2085           // Use R_X86_64_RELATIVE relocation for R_X86_64_32 under x32.
2086           if (size == 32 && r_type == elfcpp::R_X86_64_32)
2087             {
2088               unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2089               Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2090               rela_dyn->add_local_relative(object, r_sym,
2091                                            elfcpp::R_X86_64_RELATIVE,
2092                                            output_section, data_shndx,
2093                                            reloc.get_r_offset(),
2094                                            reloc.get_r_addend(), is_ifunc);
2095               break;
2096             }
2097
2098           this->check_non_pic(object, r_type, NULL);
2099
2100           Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2101           unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2102           if (lsym.get_st_type() != elfcpp::STT_SECTION)
2103             rela_dyn->add_local(object, r_sym, r_type, output_section,
2104                                 data_shndx, reloc.get_r_offset(),
2105                                 reloc.get_r_addend());
2106           else
2107             {
2108               gold_assert(lsym.get_st_value() == 0);
2109               unsigned int shndx = lsym.get_st_shndx();
2110               bool is_ordinary;
2111               shndx = object->adjust_sym_shndx(r_sym, shndx,
2112                                                &is_ordinary);
2113               if (!is_ordinary)
2114                 object->error(_("section symbol %u has bad shndx %u"),
2115                               r_sym, shndx);
2116               else
2117                 rela_dyn->add_local_section(object, shndx,
2118                                             r_type, output_section,
2119                                             data_shndx, reloc.get_r_offset(),
2120                                             reloc.get_r_addend());
2121             }
2122         }
2123       break;
2124
2125     case elfcpp::R_X86_64_PC64:
2126     case elfcpp::R_X86_64_PC32:
2127     case elfcpp::R_X86_64_PC16:
2128     case elfcpp::R_X86_64_PC8:
2129       break;
2130
2131     case elfcpp::R_X86_64_PLT32:
2132       // Since we know this is a local symbol, we can handle this as a
2133       // PC32 reloc.
2134       break;
2135
2136     case elfcpp::R_X86_64_GOTPC32:
2137     case elfcpp::R_X86_64_GOTOFF64:
2138     case elfcpp::R_X86_64_GOTPC64:
2139     case elfcpp::R_X86_64_PLTOFF64:
2140       // We need a GOT section.
2141       target->got_section(symtab, layout);
2142       // For PLTOFF64, we'd normally want a PLT section, but since we
2143       // know this is a local symbol, no PLT is needed.
2144       break;
2145
2146     case elfcpp::R_X86_64_GOT64:
2147     case elfcpp::R_X86_64_GOT32:
2148     case elfcpp::R_X86_64_GOTPCREL64:
2149     case elfcpp::R_X86_64_GOTPCREL:
2150     case elfcpp::R_X86_64_GOTPLT64:
2151       {
2152         // The symbol requires a GOT entry.
2153         Output_data_got<64, false>* got = target->got_section(symtab, layout);
2154         unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2155
2156         // For a STT_GNU_IFUNC symbol we want the PLT offset.  That
2157         // lets function pointers compare correctly with shared
2158         // libraries.  Otherwise we would need an IRELATIVE reloc.
2159         bool is_new;
2160         if (is_ifunc)
2161           is_new = got->add_local_plt(object, r_sym, GOT_TYPE_STANDARD);
2162         else
2163           is_new = got->add_local(object, r_sym, GOT_TYPE_STANDARD);
2164         if (is_new)
2165           {
2166             // If we are generating a shared object, we need to add a
2167             // dynamic relocation for this symbol's GOT entry.
2168             if (parameters->options().output_is_position_independent())
2169               {
2170                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2171                 // R_X86_64_RELATIVE assumes a 64-bit relocation.
2172                 if (r_type != elfcpp::R_X86_64_GOT32)
2173                   {
2174                     unsigned int got_offset =
2175                       object->local_got_offset(r_sym, GOT_TYPE_STANDARD);
2176                     rela_dyn->add_local_relative(object, r_sym,
2177                                                  elfcpp::R_X86_64_RELATIVE,
2178                                                  got, got_offset, 0, is_ifunc);
2179                   }
2180                 else
2181                   {
2182                     this->check_non_pic(object, r_type, NULL);
2183
2184                     gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
2185                     rela_dyn->add_local(
2186                         object, r_sym, r_type, got,
2187                         object->local_got_offset(r_sym, GOT_TYPE_STANDARD), 0);
2188                   }
2189               }
2190           }
2191         // For GOTPLT64, we'd normally want a PLT section, but since
2192         // we know this is a local symbol, no PLT is needed.
2193       }
2194       break;
2195
2196     case elfcpp::R_X86_64_COPY:
2197     case elfcpp::R_X86_64_GLOB_DAT:
2198     case elfcpp::R_X86_64_JUMP_SLOT:
2199     case elfcpp::R_X86_64_RELATIVE:
2200     case elfcpp::R_X86_64_IRELATIVE:
2201       // These are outstanding tls relocs, which are unexpected when linking
2202     case elfcpp::R_X86_64_TPOFF64:
2203     case elfcpp::R_X86_64_DTPMOD64:
2204     case elfcpp::R_X86_64_TLSDESC:
2205       gold_error(_("%s: unexpected reloc %u in object file"),
2206                  object->name().c_str(), r_type);
2207       break;
2208
2209       // These are initial tls relocs, which are expected when linking
2210     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
2211     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
2212     case elfcpp::R_X86_64_TLSDESC_CALL:
2213     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
2214     case elfcpp::R_X86_64_DTPOFF32:
2215     case elfcpp::R_X86_64_DTPOFF64:
2216     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
2217     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
2218       {
2219         bool output_is_shared = parameters->options().shared();
2220         const tls::Tls_optimization optimized_type
2221             = Target_x86_64<size>::optimize_tls_reloc(!output_is_shared,
2222                                                       r_type);
2223         switch (r_type)
2224           {
2225           case elfcpp::R_X86_64_TLSGD:       // General-dynamic
2226             if (optimized_type == tls::TLSOPT_NONE)
2227               {
2228                 // Create a pair of GOT entries for the module index and
2229                 // dtv-relative offset.
2230                 Output_data_got<64, false>* got
2231                     = target->got_section(symtab, layout);
2232                 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2233                 unsigned int shndx = lsym.get_st_shndx();
2234                 bool is_ordinary;
2235                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
2236                 if (!is_ordinary)
2237                   object->error(_("local symbol %u has bad shndx %u"),
2238                               r_sym, shndx);
2239                 else
2240                   got->add_local_pair_with_rel(object, r_sym,
2241                                                shndx,
2242                                                GOT_TYPE_TLS_PAIR,
2243                                                target->rela_dyn_section(layout),
2244                                                elfcpp::R_X86_64_DTPMOD64, 0);
2245               }
2246             else if (optimized_type != tls::TLSOPT_TO_LE)
2247               unsupported_reloc_local(object, r_type);
2248             break;
2249
2250           case elfcpp::R_X86_64_GOTPC32_TLSDESC:
2251             target->define_tls_base_symbol(symtab, layout);
2252             if (optimized_type == tls::TLSOPT_NONE)
2253               {
2254                 // Create reserved PLT and GOT entries for the resolver.
2255                 target->reserve_tlsdesc_entries(symtab, layout);
2256
2257                 // Generate a double GOT entry with an
2258                 // R_X86_64_TLSDESC reloc.  The R_X86_64_TLSDESC reloc
2259                 // is resolved lazily, so the GOT entry needs to be in
2260                 // an area in .got.plt, not .got.  Call got_section to
2261                 // make sure the section has been created.
2262                 target->got_section(symtab, layout);
2263                 Output_data_got<64, false>* got = target->got_tlsdesc_section();
2264                 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2265                 if (!object->local_has_got_offset(r_sym, GOT_TYPE_TLS_DESC))
2266                   {
2267                     unsigned int got_offset = got->add_constant(0);
2268                     got->add_constant(0);
2269                     object->set_local_got_offset(r_sym, GOT_TYPE_TLS_DESC,
2270                                                  got_offset);
2271                     Reloc_section* rt = target->rela_tlsdesc_section(layout);
2272                     // We store the arguments we need in a vector, and
2273                     // use the index into the vector as the parameter
2274                     // to pass to the target specific routines.
2275                     uintptr_t intarg = target->add_tlsdesc_info(object, r_sym);
2276                     void* arg = reinterpret_cast<void*>(intarg);
2277                     rt->add_target_specific(elfcpp::R_X86_64_TLSDESC, arg,
2278                                             got, got_offset, 0);
2279                   }
2280               }
2281             else if (optimized_type != tls::TLSOPT_TO_LE)
2282               unsupported_reloc_local(object, r_type);
2283             break;
2284
2285           case elfcpp::R_X86_64_TLSDESC_CALL:
2286             break;
2287
2288           case elfcpp::R_X86_64_TLSLD:       // Local-dynamic
2289             if (optimized_type == tls::TLSOPT_NONE)
2290               {
2291                 // Create a GOT entry for the module index.
2292                 target->got_mod_index_entry(symtab, layout, object);
2293               }
2294             else if (optimized_type != tls::TLSOPT_TO_LE)
2295               unsupported_reloc_local(object, r_type);
2296             break;
2297
2298           case elfcpp::R_X86_64_DTPOFF32:
2299           case elfcpp::R_X86_64_DTPOFF64:
2300             break;
2301
2302           case elfcpp::R_X86_64_GOTTPOFF:    // Initial-exec
2303             layout->set_has_static_tls();
2304             if (optimized_type == tls::TLSOPT_NONE)
2305               {
2306                 // Create a GOT entry for the tp-relative offset.
2307                 Output_data_got<64, false>* got
2308                     = target->got_section(symtab, layout);
2309                 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2310                 got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
2311                                         target->rela_dyn_section(layout),
2312                                         elfcpp::R_X86_64_TPOFF64);
2313               }
2314             else if (optimized_type != tls::TLSOPT_TO_LE)
2315               unsupported_reloc_local(object, r_type);
2316             break;
2317
2318           case elfcpp::R_X86_64_TPOFF32:     // Local-exec
2319             layout->set_has_static_tls();
2320             if (output_is_shared)
2321               unsupported_reloc_local(object, r_type);
2322             break;
2323
2324           default:
2325             gold_unreachable();
2326           }
2327       }
2328       break;
2329
2330     case elfcpp::R_X86_64_SIZE32:
2331     case elfcpp::R_X86_64_SIZE64:
2332     default:
2333       gold_error(_("%s: unsupported reloc %u against local symbol"),
2334                  object->name().c_str(), r_type);
2335       break;
2336     }
2337 }
2338
2339
2340 // Report an unsupported relocation against a global symbol.
2341
2342 template<int size>
2343 void
2344 Target_x86_64<size>::Scan::unsupported_reloc_global(
2345     Sized_relobj_file<size, false>* object,
2346     unsigned int r_type,
2347     Symbol* gsym)
2348 {
2349   gold_error(_("%s: unsupported reloc %u against global symbol %s"),
2350              object->name().c_str(), r_type, gsym->demangled_name().c_str());
2351 }
2352
2353 // Returns true if this relocation type could be that of a function pointer.
2354 template<int size>
2355 inline bool
2356 Target_x86_64<size>::Scan::possible_function_pointer_reloc(unsigned int r_type)
2357 {
2358   switch (r_type)
2359     {
2360     case elfcpp::R_X86_64_64:
2361     case elfcpp::R_X86_64_32:
2362     case elfcpp::R_X86_64_32S:
2363     case elfcpp::R_X86_64_16:
2364     case elfcpp::R_X86_64_8:
2365     case elfcpp::R_X86_64_GOT64:
2366     case elfcpp::R_X86_64_GOT32:
2367     case elfcpp::R_X86_64_GOTPCREL64:
2368     case elfcpp::R_X86_64_GOTPCREL:
2369     case elfcpp::R_X86_64_GOTPLT64:
2370       {
2371         return true;
2372       }
2373     }
2374   return false;
2375 }
2376
2377 // For safe ICF, scan a relocation for a local symbol to check if it
2378 // corresponds to a function pointer being taken.  In that case mark
2379 // the function whose pointer was taken as not foldable.
2380
2381 template<int size>
2382 inline bool
2383 Target_x86_64<size>::Scan::local_reloc_may_be_function_pointer(
2384   Symbol_table* ,
2385   Layout* ,
2386   Target_x86_64<size>* ,
2387   Sized_relobj_file<size, false>* ,
2388   unsigned int ,
2389   Output_section* ,
2390   const elfcpp::Rela<size, false>& ,
2391   unsigned int r_type,
2392   const elfcpp::Sym<size, false>&)
2393 {
2394   // When building a shared library, do not fold any local symbols as it is
2395   // not possible to distinguish pointer taken versus a call by looking at
2396   // the relocation types.
2397   return (parameters->options().shared()
2398           || possible_function_pointer_reloc(r_type));
2399 }
2400
2401 // For safe ICF, scan a relocation for a global symbol to check if it
2402 // corresponds to a function pointer being taken.  In that case mark
2403 // the function whose pointer was taken as not foldable.
2404
2405 template<int size>
2406 inline bool
2407 Target_x86_64<size>::Scan::global_reloc_may_be_function_pointer(
2408   Symbol_table*,
2409   Layout* ,
2410   Target_x86_64<size>* ,
2411   Sized_relobj_file<size, false>* ,
2412   unsigned int ,
2413   Output_section* ,
2414   const elfcpp::Rela<size, false>& ,
2415   unsigned int r_type,
2416   Symbol* gsym)
2417 {
2418   // When building a shared library, do not fold symbols whose visibility
2419   // is hidden, internal or protected.
2420   return ((parameters->options().shared()
2421            && (gsym->visibility() == elfcpp::STV_INTERNAL
2422                || gsym->visibility() == elfcpp::STV_PROTECTED
2423                || gsym->visibility() == elfcpp::STV_HIDDEN))
2424           || possible_function_pointer_reloc(r_type));
2425 }
2426
2427 // Scan a relocation for a global symbol.
2428
2429 template<int size>
2430 inline void
2431 Target_x86_64<size>::Scan::global(Symbol_table* symtab,
2432                             Layout* layout,
2433                             Target_x86_64<size>* target,
2434                             Sized_relobj_file<size, false>* object,
2435                             unsigned int data_shndx,
2436                             Output_section* output_section,
2437                             const elfcpp::Rela<size, false>& reloc,
2438                             unsigned int r_type,
2439                             Symbol* gsym)
2440 {
2441   // A STT_GNU_IFUNC symbol may require a PLT entry.
2442   if (gsym->type() == elfcpp::STT_GNU_IFUNC
2443       && this->reloc_needs_plt_for_ifunc(object, r_type))
2444     target->make_plt_entry(symtab, layout, gsym);
2445
2446   switch (r_type)
2447     {
2448     case elfcpp::R_X86_64_NONE:
2449     case elfcpp::R_X86_64_GNU_VTINHERIT:
2450     case elfcpp::R_X86_64_GNU_VTENTRY:
2451       break;
2452
2453     case elfcpp::R_X86_64_64:
2454     case elfcpp::R_X86_64_32:
2455     case elfcpp::R_X86_64_32S:
2456     case elfcpp::R_X86_64_16:
2457     case elfcpp::R_X86_64_8:
2458       {
2459         // Make a PLT entry if necessary.
2460         if (gsym->needs_plt_entry())
2461           {
2462             target->make_plt_entry(symtab, layout, gsym);
2463             // Since this is not a PC-relative relocation, we may be
2464             // taking the address of a function. In that case we need to
2465             // set the entry in the dynamic symbol table to the address of
2466             // the PLT entry.
2467             if (gsym->is_from_dynobj() && !parameters->options().shared())
2468               gsym->set_needs_dynsym_value();
2469           }
2470         // Make a dynamic relocation if necessary.
2471         if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
2472           {
2473             if (gsym->may_need_copy_reloc())
2474               {
2475                 target->copy_reloc(symtab, layout, object,
2476                                    data_shndx, output_section, gsym, reloc);
2477               }
2478             else if (r_type == elfcpp::R_X86_64_64
2479                      && gsym->type() == elfcpp::STT_GNU_IFUNC
2480                      && gsym->can_use_relative_reloc(false)
2481                      && !gsym->is_from_dynobj()
2482                      && !gsym->is_undefined()
2483                      && !gsym->is_preemptible())
2484               {
2485                 // Use an IRELATIVE reloc for a locally defined
2486                 // STT_GNU_IFUNC symbol.  This makes a function
2487                 // address in a PIE executable match the address in a
2488                 // shared library that it links against.
2489                 Reloc_section* rela_dyn =
2490                   target->rela_irelative_section(layout);
2491                 unsigned int r_type = elfcpp::R_X86_64_IRELATIVE;
2492                 rela_dyn->add_symbolless_global_addend(gsym, r_type,
2493                                                        output_section, object,
2494                                                        data_shndx,
2495                                                        reloc.get_r_offset(),
2496                                                        reloc.get_r_addend());
2497               }
2498             else if (r_type == elfcpp::R_X86_64_64
2499                      && gsym->can_use_relative_reloc(false))
2500               {
2501                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2502                 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_RELATIVE,
2503                                               output_section, object,
2504                                               data_shndx,
2505                                               reloc.get_r_offset(),
2506                                               reloc.get_r_addend());
2507               }
2508             else
2509               {
2510                 this->check_non_pic(object, r_type, gsym);
2511                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2512                 rela_dyn->add_global(gsym, r_type, output_section, object,
2513                                      data_shndx, reloc.get_r_offset(),
2514                                      reloc.get_r_addend());
2515               }
2516           }
2517       }
2518       break;
2519
2520     case elfcpp::R_X86_64_PC64:
2521     case elfcpp::R_X86_64_PC32:
2522     case elfcpp::R_X86_64_PC16:
2523     case elfcpp::R_X86_64_PC8:
2524       {
2525         // Make a PLT entry if necessary.
2526         if (gsym->needs_plt_entry())
2527           target->make_plt_entry(symtab, layout, gsym);
2528         // Make a dynamic relocation if necessary.
2529         if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
2530           {
2531             if (gsym->may_need_copy_reloc())
2532               {
2533                 target->copy_reloc(symtab, layout, object,
2534                                    data_shndx, output_section, gsym, reloc);
2535               }
2536             else
2537               {
2538                 this->check_non_pic(object, r_type, gsym);
2539                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2540                 rela_dyn->add_global(gsym, r_type, output_section, object,
2541                                      data_shndx, reloc.get_r_offset(),
2542                                      reloc.get_r_addend());
2543               }
2544           }
2545       }
2546       break;
2547
2548     case elfcpp::R_X86_64_GOT64:
2549     case elfcpp::R_X86_64_GOT32:
2550     case elfcpp::R_X86_64_GOTPCREL64:
2551     case elfcpp::R_X86_64_GOTPCREL:
2552     case elfcpp::R_X86_64_GOTPLT64:
2553       {
2554         // The symbol requires a GOT entry.
2555         Output_data_got<64, false>* got = target->got_section(symtab, layout);
2556         if (gsym->final_value_is_known())
2557           {
2558             // For a STT_GNU_IFUNC symbol we want the PLT address.
2559             if (gsym->type() == elfcpp::STT_GNU_IFUNC)
2560               got->add_global_plt(gsym, GOT_TYPE_STANDARD);
2561             else
2562               got->add_global(gsym, GOT_TYPE_STANDARD);
2563           }
2564         else
2565           {
2566             // If this symbol is not fully resolved, we need to add a
2567             // dynamic relocation for it.
2568             Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2569
2570             // Use a GLOB_DAT rather than a RELATIVE reloc if:
2571             //
2572             // 1) The symbol may be defined in some other module.
2573             //
2574             // 2) We are building a shared library and this is a
2575             // protected symbol; using GLOB_DAT means that the dynamic
2576             // linker can use the address of the PLT in the main
2577             // executable when appropriate so that function address
2578             // comparisons work.
2579             //
2580             // 3) This is a STT_GNU_IFUNC symbol in position dependent
2581             // code, again so that function address comparisons work.
2582             if (gsym->is_from_dynobj()
2583                 || gsym->is_undefined()
2584                 || gsym->is_preemptible()
2585                 || (gsym->visibility() == elfcpp::STV_PROTECTED
2586                     && parameters->options().shared())
2587                 || (gsym->type() == elfcpp::STT_GNU_IFUNC
2588                     && parameters->options().output_is_position_independent()))
2589               got->add_global_with_rel(gsym, GOT_TYPE_STANDARD, rela_dyn,
2590                                        elfcpp::R_X86_64_GLOB_DAT);
2591             else
2592               {
2593                 // For a STT_GNU_IFUNC symbol we want to write the PLT
2594                 // offset into the GOT, so that function pointer
2595                 // comparisons work correctly.
2596                 bool is_new;
2597                 if (gsym->type() != elfcpp::STT_GNU_IFUNC)
2598                   is_new = got->add_global(gsym, GOT_TYPE_STANDARD);
2599                 else
2600                   {
2601                     is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD);
2602                     // Tell the dynamic linker to use the PLT address
2603                     // when resolving relocations.
2604                     if (gsym->is_from_dynobj()
2605                         && !parameters->options().shared())
2606                       gsym->set_needs_dynsym_value();
2607                   }
2608                 if (is_new)
2609                   {
2610                     unsigned int got_off = gsym->got_offset(GOT_TYPE_STANDARD);
2611                     rela_dyn->add_global_relative(gsym,
2612                                                   elfcpp::R_X86_64_RELATIVE,
2613                                                   got, got_off, 0);
2614                   }
2615               }
2616           }
2617         // For GOTPLT64, we also need a PLT entry (but only if the
2618         // symbol is not fully resolved).
2619         if (r_type == elfcpp::R_X86_64_GOTPLT64
2620             && !gsym->final_value_is_known())
2621           target->make_plt_entry(symtab, layout, gsym);
2622       }
2623       break;
2624
2625     case elfcpp::R_X86_64_PLT32:
2626       // If the symbol is fully resolved, this is just a PC32 reloc.
2627       // Otherwise we need a PLT entry.
2628       if (gsym->final_value_is_known())
2629         break;
2630       // If building a shared library, we can also skip the PLT entry
2631       // if the symbol is defined in the output file and is protected
2632       // or hidden.
2633       if (gsym->is_defined()
2634           && !gsym->is_from_dynobj()
2635           && !gsym->is_preemptible())
2636         break;
2637       target->make_plt_entry(symtab, layout, gsym);
2638       break;
2639
2640     case elfcpp::R_X86_64_GOTPC32:
2641     case elfcpp::R_X86_64_GOTOFF64:
2642     case elfcpp::R_X86_64_GOTPC64:
2643     case elfcpp::R_X86_64_PLTOFF64:
2644       // We need a GOT section.
2645       target->got_section(symtab, layout);
2646       // For PLTOFF64, we also need a PLT entry (but only if the
2647       // symbol is not fully resolved).
2648       if (r_type == elfcpp::R_X86_64_PLTOFF64
2649           && !gsym->final_value_is_known())
2650         target->make_plt_entry(symtab, layout, gsym);
2651       break;
2652
2653     case elfcpp::R_X86_64_COPY:
2654     case elfcpp::R_X86_64_GLOB_DAT:
2655     case elfcpp::R_X86_64_JUMP_SLOT:
2656     case elfcpp::R_X86_64_RELATIVE:
2657     case elfcpp::R_X86_64_IRELATIVE:
2658       // These are outstanding tls relocs, which are unexpected when linking
2659     case elfcpp::R_X86_64_TPOFF64:
2660     case elfcpp::R_X86_64_DTPMOD64:
2661     case elfcpp::R_X86_64_TLSDESC:
2662       gold_error(_("%s: unexpected reloc %u in object file"),
2663                  object->name().c_str(), r_type);
2664       break;
2665
2666       // These are initial tls relocs, which are expected for global()
2667     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
2668     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
2669     case elfcpp::R_X86_64_TLSDESC_CALL:
2670     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
2671     case elfcpp::R_X86_64_DTPOFF32:
2672     case elfcpp::R_X86_64_DTPOFF64:
2673     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
2674     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
2675       {
2676         const bool is_final = gsym->final_value_is_known();
2677         const tls::Tls_optimization optimized_type
2678             = Target_x86_64<size>::optimize_tls_reloc(is_final, r_type);
2679         switch (r_type)
2680           {
2681           case elfcpp::R_X86_64_TLSGD:       // General-dynamic
2682             if (optimized_type == tls::TLSOPT_NONE)
2683               {
2684                 // Create a pair of GOT entries for the module index and
2685                 // dtv-relative offset.
2686                 Output_data_got<64, false>* got
2687                     = target->got_section(symtab, layout);
2688                 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
2689                                               target->rela_dyn_section(layout),
2690                                               elfcpp::R_X86_64_DTPMOD64,
2691                                               elfcpp::R_X86_64_DTPOFF64);
2692               }
2693             else if (optimized_type == tls::TLSOPT_TO_IE)
2694               {
2695                 // Create a GOT entry for the tp-relative offset.
2696                 Output_data_got<64, false>* got
2697                     = target->got_section(symtab, layout);
2698                 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
2699                                          target->rela_dyn_section(layout),
2700                                          elfcpp::R_X86_64_TPOFF64);
2701               }
2702             else if (optimized_type != tls::TLSOPT_TO_LE)
2703               unsupported_reloc_global(object, r_type, gsym);
2704             break;
2705
2706           case elfcpp::R_X86_64_GOTPC32_TLSDESC:
2707             target->define_tls_base_symbol(symtab, layout);
2708             if (optimized_type == tls::TLSOPT_NONE)
2709               {
2710                 // Create reserved PLT and GOT entries for the resolver.
2711                 target->reserve_tlsdesc_entries(symtab, layout);
2712
2713                 // Create a double GOT entry with an R_X86_64_TLSDESC
2714                 // reloc.  The R_X86_64_TLSDESC reloc is resolved
2715                 // lazily, so the GOT entry needs to be in an area in
2716                 // .got.plt, not .got.  Call got_section to make sure
2717                 // the section has been created.
2718                 target->got_section(symtab, layout);
2719                 Output_data_got<64, false>* got = target->got_tlsdesc_section();
2720                 Reloc_section* rt = target->rela_tlsdesc_section(layout);
2721                 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC, rt,
2722                                               elfcpp::R_X86_64_TLSDESC, 0);
2723               }
2724             else if (optimized_type == tls::TLSOPT_TO_IE)
2725               {
2726                 // Create a GOT entry for the tp-relative offset.
2727                 Output_data_got<64, false>* got
2728                     = target->got_section(symtab, layout);
2729                 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
2730                                          target->rela_dyn_section(layout),
2731                                          elfcpp::R_X86_64_TPOFF64);
2732               }
2733             else if (optimized_type != tls::TLSOPT_TO_LE)
2734               unsupported_reloc_global(object, r_type, gsym);
2735             break;
2736
2737           case elfcpp::R_X86_64_TLSDESC_CALL:
2738             break;
2739
2740           case elfcpp::R_X86_64_TLSLD:       // Local-dynamic
2741             if (optimized_type == tls::TLSOPT_NONE)
2742               {
2743                 // Create a GOT entry for the module index.
2744                 target->got_mod_index_entry(symtab, layout, object);
2745               }
2746             else if (optimized_type != tls::TLSOPT_TO_LE)
2747               unsupported_reloc_global(object, r_type, gsym);
2748             break;
2749
2750           case elfcpp::R_X86_64_DTPOFF32:
2751           case elfcpp::R_X86_64_DTPOFF64:
2752             break;
2753
2754           case elfcpp::R_X86_64_GOTTPOFF:    // Initial-exec
2755             layout->set_has_static_tls();
2756             if (optimized_type == tls::TLSOPT_NONE)
2757               {
2758                 // Create a GOT entry for the tp-relative offset.
2759                 Output_data_got<64, false>* got
2760                     = target->got_section(symtab, layout);
2761                 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
2762                                          target->rela_dyn_section(layout),
2763                                          elfcpp::R_X86_64_TPOFF64);
2764               }
2765             else if (optimized_type != tls::TLSOPT_TO_LE)
2766               unsupported_reloc_global(object, r_type, gsym);
2767             break;
2768
2769           case elfcpp::R_X86_64_TPOFF32:     // Local-exec
2770             layout->set_has_static_tls();
2771             if (parameters->options().shared())
2772               unsupported_reloc_local(object, r_type);
2773             break;
2774
2775           default:
2776             gold_unreachable();
2777           }
2778       }
2779       break;
2780
2781     case elfcpp::R_X86_64_SIZE32:
2782     case elfcpp::R_X86_64_SIZE64:
2783     default:
2784       gold_error(_("%s: unsupported reloc %u against global symbol %s"),
2785                  object->name().c_str(), r_type,
2786                  gsym->demangled_name().c_str());
2787       break;
2788     }
2789 }
2790
2791 template<int size>
2792 void
2793 Target_x86_64<size>::gc_process_relocs(Symbol_table* symtab,
2794                                        Layout* layout,
2795                                        Sized_relobj_file<size, false>* object,
2796                                        unsigned int data_shndx,
2797                                        unsigned int sh_type,
2798                                        const unsigned char* prelocs,
2799                                        size_t reloc_count,
2800                                        Output_section* output_section,
2801                                        bool needs_special_offset_handling,
2802                                        size_t local_symbol_count,
2803                                        const unsigned char* plocal_symbols)
2804 {
2805
2806   if (sh_type == elfcpp::SHT_REL)
2807     {
2808       return;
2809     }
2810
2811    gold::gc_process_relocs<size, false, Target_x86_64<size>, elfcpp::SHT_RELA,
2812                            typename Target_x86_64<size>::Scan,
2813                            typename Target_x86_64<size>::Relocatable_size_for_reloc>(
2814     symtab,
2815     layout,
2816     this,
2817     object,
2818     data_shndx,
2819     prelocs,
2820     reloc_count,
2821     output_section,
2822     needs_special_offset_handling,
2823     local_symbol_count,
2824     plocal_symbols);
2825
2826 }
2827 // Scan relocations for a section.
2828
2829 template<int size>
2830 void
2831 Target_x86_64<size>::scan_relocs(Symbol_table* symtab,
2832                                  Layout* layout,
2833                                  Sized_relobj_file<size, false>* object,
2834                                  unsigned int data_shndx,
2835                                  unsigned int sh_type,
2836                                  const unsigned char* prelocs,
2837                                  size_t reloc_count,
2838                                  Output_section* output_section,
2839                                  bool needs_special_offset_handling,
2840                                  size_t local_symbol_count,
2841                                  const unsigned char* plocal_symbols)
2842 {
2843   if (sh_type == elfcpp::SHT_REL)
2844     {
2845       gold_error(_("%s: unsupported REL reloc section"),
2846                  object->name().c_str());
2847       return;
2848     }
2849
2850   gold::scan_relocs<size, false, Target_x86_64<size>, elfcpp::SHT_RELA,
2851       typename Target_x86_64<size>::Scan>(
2852     symtab,
2853     layout,
2854     this,
2855     object,
2856     data_shndx,
2857     prelocs,
2858     reloc_count,
2859     output_section,
2860     needs_special_offset_handling,
2861     local_symbol_count,
2862     plocal_symbols);
2863 }
2864
2865 // Finalize the sections.
2866
2867 template<int size>
2868 void
2869 Target_x86_64<size>::do_finalize_sections(
2870     Layout* layout,
2871     const Input_objects*,
2872     Symbol_table* symtab)
2873 {
2874   const Reloc_section* rel_plt = (this->plt_ == NULL
2875                                   ? NULL
2876                                   : this->plt_->rela_plt());
2877   layout->add_target_dynamic_tags(false, this->got_plt_, rel_plt,
2878                                   this->rela_dyn_, true, false);
2879
2880   // Fill in some more dynamic tags.
2881   Output_data_dynamic* const odyn = layout->dynamic_data();
2882   if (odyn != NULL)
2883     {
2884       if (this->plt_ != NULL
2885           && this->plt_->output_section() != NULL
2886           && this->plt_->has_tlsdesc_entry())
2887         {
2888           unsigned int plt_offset = this->plt_->get_tlsdesc_plt_offset();
2889           unsigned int got_offset = this->plt_->get_tlsdesc_got_offset();
2890           this->got_->finalize_data_size();
2891           odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_PLT,
2892                                         this->plt_, plt_offset);
2893           odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_GOT,
2894                                         this->got_, got_offset);
2895         }
2896     }
2897
2898   // Emit any relocs we saved in an attempt to avoid generating COPY
2899   // relocs.
2900   if (this->copy_relocs_.any_saved_relocs())
2901     this->copy_relocs_.emit(this->rela_dyn_section(layout));
2902
2903   // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
2904   // the .got.plt section.
2905   Symbol* sym = this->global_offset_table_;
2906   if (sym != NULL)
2907     {
2908       uint64_t data_size = this->got_plt_->current_data_size();
2909       symtab->get_sized_symbol<size>(sym)->set_symsize(data_size);
2910     }
2911
2912   if (parameters->doing_static_link()
2913       && (this->plt_ == NULL || !this->plt_->has_irelative_section()))
2914     {
2915       // If linking statically, make sure that the __rela_iplt symbols
2916       // were defined if necessary, even if we didn't create a PLT.
2917       static const Define_symbol_in_segment syms[] =
2918         {
2919           {
2920             "__rela_iplt_start",        // name
2921             elfcpp::PT_LOAD,            // segment_type
2922             elfcpp::PF_W,               // segment_flags_set
2923             elfcpp::PF(0),              // segment_flags_clear
2924             0,                          // value
2925             0,                          // size
2926             elfcpp::STT_NOTYPE,         // type
2927             elfcpp::STB_GLOBAL,         // binding
2928             elfcpp::STV_HIDDEN,         // visibility
2929             0,                          // nonvis
2930             Symbol::SEGMENT_START,      // offset_from_base
2931             true                        // only_if_ref
2932           },
2933           {
2934             "__rela_iplt_end",          // name
2935             elfcpp::PT_LOAD,            // segment_type
2936             elfcpp::PF_W,               // segment_flags_set
2937             elfcpp::PF(0),              // segment_flags_clear
2938             0,                          // value
2939             0,                          // size
2940             elfcpp::STT_NOTYPE,         // type
2941             elfcpp::STB_GLOBAL,         // binding
2942             elfcpp::STV_HIDDEN,         // visibility
2943             0,                          // nonvis
2944             Symbol::SEGMENT_START,      // offset_from_base
2945             true                        // only_if_ref
2946           }
2947         };
2948
2949       symtab->define_symbols(layout, 2, syms,
2950                              layout->script_options()->saw_sections_clause());
2951     }
2952 }
2953
2954 // Perform a relocation.
2955
2956 template<int size>
2957 inline bool
2958 Target_x86_64<size>::Relocate::relocate(
2959     const Relocate_info<size, false>* relinfo,
2960     Target_x86_64<size>* target,
2961     Output_section*,
2962     size_t relnum,
2963     const elfcpp::Rela<size, false>& rela,
2964     unsigned int r_type,
2965     const Sized_symbol<size>* gsym,
2966     const Symbol_value<size>* psymval,
2967     unsigned char* view,
2968     typename elfcpp::Elf_types<size>::Elf_Addr address,
2969     section_size_type view_size)
2970 {
2971   if (this->skip_call_tls_get_addr_)
2972     {
2973       if ((r_type != elfcpp::R_X86_64_PLT32
2974            && r_type != elfcpp::R_X86_64_PC32)
2975           || gsym == NULL
2976           || strcmp(gsym->name(), "__tls_get_addr") != 0)
2977         {
2978           gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
2979                                  _("missing expected TLS relocation"));
2980         }
2981       else
2982         {
2983           this->skip_call_tls_get_addr_ = false;
2984           return false;
2985         }
2986     }
2987
2988   const Sized_relobj_file<size, false>* object = relinfo->object;
2989
2990   // Pick the value to use for symbols defined in the PLT.
2991   Symbol_value<size> symval;
2992   if (gsym != NULL
2993       && gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
2994     {
2995       symval.set_output_value(target->plt_address_for_global(gsym)
2996                               + gsym->plt_offset());
2997       psymval = &symval;
2998     }
2999   else if (gsym == NULL && psymval->is_ifunc_symbol())
3000     {
3001       unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3002       if (object->local_has_plt_offset(r_sym))
3003         {
3004           symval.set_output_value(target->plt_address_for_local(object, r_sym)
3005                                   + object->local_plt_offset(r_sym));
3006           psymval = &symval;
3007         }
3008     }
3009
3010   const elfcpp::Elf_Xword addend = rela.get_r_addend();
3011
3012   // Get the GOT offset if needed.
3013   // The GOT pointer points to the end of the GOT section.
3014   // We need to subtract the size of the GOT section to get
3015   // the actual offset to use in the relocation.
3016   bool have_got_offset = false;
3017   unsigned int got_offset = 0;
3018   switch (r_type)
3019     {
3020     case elfcpp::R_X86_64_GOT32:
3021     case elfcpp::R_X86_64_GOT64:
3022     case elfcpp::R_X86_64_GOTPLT64:
3023     case elfcpp::R_X86_64_GOTPCREL:
3024     case elfcpp::R_X86_64_GOTPCREL64:
3025       if (gsym != NULL)
3026         {
3027           gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
3028           got_offset = gsym->got_offset(GOT_TYPE_STANDARD) - target->got_size();
3029         }
3030       else
3031         {
3032           unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3033           gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
3034           got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
3035                         - target->got_size());
3036         }
3037       have_got_offset = true;
3038       break;
3039
3040     default:
3041       break;
3042     }
3043
3044   switch (r_type)
3045     {
3046     case elfcpp::R_X86_64_NONE:
3047     case elfcpp::R_X86_64_GNU_VTINHERIT:
3048     case elfcpp::R_X86_64_GNU_VTENTRY:
3049       break;
3050
3051     case elfcpp::R_X86_64_64:
3052       Relocate_functions<size, false>::rela64(view, object, psymval, addend);
3053       break;
3054
3055     case elfcpp::R_X86_64_PC64:
3056       Relocate_functions<size, false>::pcrela64(view, object, psymval, addend,
3057                                               address);
3058       break;
3059
3060     case elfcpp::R_X86_64_32:
3061       // FIXME: we need to verify that value + addend fits into 32 bits:
3062       //    uint64_t x = value + addend;
3063       //    x == static_cast<uint64_t>(static_cast<uint32_t>(x))
3064       // Likewise for other <=32-bit relocations (but see R_X86_64_32S).
3065       Relocate_functions<size, false>::rela32(view, object, psymval, addend);
3066       break;
3067
3068     case elfcpp::R_X86_64_32S:
3069       // FIXME: we need to verify that value + addend fits into 32 bits:
3070       //    int64_t x = value + addend;   // note this quantity is signed!
3071       //    x == static_cast<int64_t>(static_cast<int32_t>(x))
3072       Relocate_functions<size, false>::rela32(view, object, psymval, addend);
3073       break;
3074
3075     case elfcpp::R_X86_64_PC32:
3076       Relocate_functions<size, false>::pcrela32(view, object, psymval, addend,
3077                                                 address);
3078       break;
3079
3080     case elfcpp::R_X86_64_16:
3081       Relocate_functions<size, false>::rela16(view, object, psymval, addend);
3082       break;
3083
3084     case elfcpp::R_X86_64_PC16:
3085       Relocate_functions<size, false>::pcrela16(view, object, psymval, addend,
3086                                                 address);
3087       break;
3088
3089     case elfcpp::R_X86_64_8:
3090       Relocate_functions<size, false>::rela8(view, object, psymval, addend);
3091       break;
3092
3093     case elfcpp::R_X86_64_PC8:
3094       Relocate_functions<size, false>::pcrela8(view, object, psymval, addend,
3095                                                address);
3096       break;
3097
3098     case elfcpp::R_X86_64_PLT32:
3099       gold_assert(gsym == NULL
3100                   || gsym->has_plt_offset()
3101                   || gsym->final_value_is_known()
3102                   || (gsym->is_defined()
3103                       && !gsym->is_from_dynobj()
3104                       && !gsym->is_preemptible()));
3105       // Note: while this code looks the same as for R_X86_64_PC32, it
3106       // behaves differently because psymval was set to point to
3107       // the PLT entry, rather than the symbol, in Scan::global().
3108       Relocate_functions<size, false>::pcrela32(view, object, psymval, addend,
3109                                                 address);
3110       break;
3111
3112     case elfcpp::R_X86_64_PLTOFF64:
3113       {
3114         gold_assert(gsym);
3115         gold_assert(gsym->has_plt_offset()
3116                     || gsym->final_value_is_known());
3117         typename elfcpp::Elf_types<size>::Elf_Addr got_address;
3118         got_address = target->got_section(NULL, NULL)->address();
3119         Relocate_functions<size, false>::rela64(view, object, psymval,
3120                                                 addend - got_address);
3121       }
3122
3123     case elfcpp::R_X86_64_GOT32:
3124       gold_assert(have_got_offset);
3125       Relocate_functions<size, false>::rela32(view, got_offset, addend);
3126       break;
3127
3128     case elfcpp::R_X86_64_GOTPC32:
3129       {
3130         gold_assert(gsym);
3131         typename elfcpp::Elf_types<size>::Elf_Addr value;
3132         value = target->got_plt_section()->address();
3133         Relocate_functions<size, false>::pcrela32(view, value, addend, address);
3134       }
3135       break;
3136
3137     case elfcpp::R_X86_64_GOT64:
3138       // The ABI doc says "Like GOT64, but indicates a PLT entry is needed."
3139       // Since we always add a PLT entry, this is equivalent.
3140     case elfcpp::R_X86_64_GOTPLT64:
3141       gold_assert(have_got_offset);
3142       Relocate_functions<size, false>::rela64(view, got_offset, addend);
3143       break;
3144
3145     case elfcpp::R_X86_64_GOTPC64:
3146       {
3147         gold_assert(gsym);
3148         typename elfcpp::Elf_types<size>::Elf_Addr value;
3149         value = target->got_plt_section()->address();
3150         Relocate_functions<size, false>::pcrela64(view, value, addend, address);
3151       }
3152       break;
3153
3154     case elfcpp::R_X86_64_GOTOFF64:
3155       {
3156         typename elfcpp::Elf_types<size>::Elf_Addr value;
3157         value = (psymval->value(object, 0)
3158                  - target->got_plt_section()->address());
3159         Relocate_functions<size, false>::rela64(view, value, addend);
3160       }
3161       break;
3162
3163     case elfcpp::R_X86_64_GOTPCREL:
3164       {
3165         gold_assert(have_got_offset);
3166         typename elfcpp::Elf_types<size>::Elf_Addr value;
3167         value = target->got_plt_section()->address() + got_offset;
3168         Relocate_functions<size, false>::pcrela32(view, value, addend, address);
3169       }
3170       break;
3171
3172     case elfcpp::R_X86_64_GOTPCREL64:
3173       {
3174         gold_assert(have_got_offset);
3175         typename elfcpp::Elf_types<size>::Elf_Addr value;
3176         value = target->got_plt_section()->address() + got_offset;
3177         Relocate_functions<size, false>::pcrela64(view, value, addend, address);
3178       }
3179       break;
3180
3181     case elfcpp::R_X86_64_COPY:
3182     case elfcpp::R_X86_64_GLOB_DAT:
3183     case elfcpp::R_X86_64_JUMP_SLOT:
3184     case elfcpp::R_X86_64_RELATIVE:
3185     case elfcpp::R_X86_64_IRELATIVE:
3186       // These are outstanding tls relocs, which are unexpected when linking
3187     case elfcpp::R_X86_64_TPOFF64:
3188     case elfcpp::R_X86_64_DTPMOD64:
3189     case elfcpp::R_X86_64_TLSDESC:
3190       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3191                              _("unexpected reloc %u in object file"),
3192                              r_type);
3193       break;
3194
3195       // These are initial tls relocs, which are expected when linking
3196     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
3197     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
3198     case elfcpp::R_X86_64_TLSDESC_CALL:
3199     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
3200     case elfcpp::R_X86_64_DTPOFF32:
3201     case elfcpp::R_X86_64_DTPOFF64:
3202     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
3203     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
3204       this->relocate_tls(relinfo, target, relnum, rela, r_type, gsym, psymval,
3205                          view, address, view_size);
3206       break;
3207
3208     case elfcpp::R_X86_64_SIZE32:
3209     case elfcpp::R_X86_64_SIZE64:
3210     default:
3211       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3212                              _("unsupported reloc %u"),
3213                              r_type);
3214       break;
3215     }
3216
3217   return true;
3218 }
3219
3220 // Perform a TLS relocation.
3221
3222 template<int size>
3223 inline void
3224 Target_x86_64<size>::Relocate::relocate_tls(
3225     const Relocate_info<size, false>* relinfo,
3226     Target_x86_64<size>* target,
3227     size_t relnum,
3228     const elfcpp::Rela<size, false>& rela,
3229     unsigned int r_type,
3230     const Sized_symbol<size>* gsym,
3231     const Symbol_value<size>* psymval,
3232     unsigned char* view,
3233     typename elfcpp::Elf_types<size>::Elf_Addr address,
3234     section_size_type view_size)
3235 {
3236   Output_segment* tls_segment = relinfo->layout->tls_segment();
3237
3238   const Sized_relobj_file<size, false>* object = relinfo->object;
3239   const elfcpp::Elf_Xword addend = rela.get_r_addend();
3240   elfcpp::Shdr<size, false> data_shdr(relinfo->data_shdr);
3241   bool is_executable = (data_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0;
3242
3243   typename elfcpp::Elf_types<size>::Elf_Addr value = psymval->value(relinfo->object, 0);
3244
3245   const bool is_final = (gsym == NULL
3246                          ? !parameters->options().shared()
3247                          : gsym->final_value_is_known());
3248   tls::Tls_optimization optimized_type
3249       = Target_x86_64<size>::optimize_tls_reloc(is_final, r_type);
3250   switch (r_type)
3251     {
3252     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
3253       if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
3254         {
3255           // If this code sequence is used in a non-executable section,
3256           // we will not optimize the R_X86_64_DTPOFF32/64 relocation,
3257           // on the assumption that it's being used by itself in a debug
3258           // section.  Therefore, in the unlikely event that the code
3259           // sequence appears in a non-executable section, we simply
3260           // leave it unoptimized.
3261           optimized_type = tls::TLSOPT_NONE;
3262         }
3263       if (optimized_type == tls::TLSOPT_TO_LE)
3264         {
3265           if (tls_segment == NULL)
3266             {
3267               gold_assert(parameters->errors()->error_count() > 0
3268                           || issue_undefined_symbol_error(gsym));
3269               return;
3270             }
3271           this->tls_gd_to_le(relinfo, relnum, tls_segment,
3272                              rela, r_type, value, view,
3273                              view_size);
3274           break;
3275         }
3276       else
3277         {
3278           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
3279                                    ? GOT_TYPE_TLS_OFFSET
3280                                    : GOT_TYPE_TLS_PAIR);
3281           unsigned int got_offset;
3282           if (gsym != NULL)
3283             {
3284               gold_assert(gsym->has_got_offset(got_type));
3285               got_offset = gsym->got_offset(got_type) - target->got_size();
3286             }
3287           else
3288             {
3289               unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3290               gold_assert(object->local_has_got_offset(r_sym, got_type));
3291               got_offset = (object->local_got_offset(r_sym, got_type)
3292                             - target->got_size());
3293             }
3294           if (optimized_type == tls::TLSOPT_TO_IE)
3295             {
3296               value = target->got_plt_section()->address() + got_offset;
3297               this->tls_gd_to_ie(relinfo, relnum, tls_segment, rela, r_type,
3298                                  value, view, address, view_size);
3299               break;
3300             }
3301           else if (optimized_type == tls::TLSOPT_NONE)
3302             {
3303               // Relocate the field with the offset of the pair of GOT
3304               // entries.
3305               value = target->got_plt_section()->address() + got_offset;
3306               Relocate_functions<size, false>::pcrela32(view, value, addend,
3307                                                         address);
3308               break;
3309             }
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_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
3316     case elfcpp::R_X86_64_TLSDESC_CALL:
3317       if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
3318         {
3319           // See above comment for R_X86_64_TLSGD.
3320           optimized_type = tls::TLSOPT_NONE;
3321         }
3322       if (optimized_type == tls::TLSOPT_TO_LE)
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           this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
3331                                   rela, r_type, value, view,
3332                                   view_size);
3333           break;
3334         }
3335       else
3336         {
3337           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
3338                                    ? GOT_TYPE_TLS_OFFSET
3339                                    : GOT_TYPE_TLS_DESC);
3340           unsigned int got_offset = 0;
3341           if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC
3342               && optimized_type == tls::TLSOPT_NONE)
3343             {
3344               // We created GOT entries in the .got.tlsdesc portion of
3345               // the .got.plt section, but the offset stored in the
3346               // symbol is the offset within .got.tlsdesc.
3347               got_offset = (target->got_size()
3348                             + target->got_plt_section()->data_size());
3349             }
3350           if (gsym != NULL)
3351             {
3352               gold_assert(gsym->has_got_offset(got_type));
3353               got_offset += gsym->got_offset(got_type) - target->got_size();
3354             }
3355           else
3356             {
3357               unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3358               gold_assert(object->local_has_got_offset(r_sym, got_type));
3359               got_offset += (object->local_got_offset(r_sym, got_type)
3360                              - target->got_size());
3361             }
3362           if (optimized_type == tls::TLSOPT_TO_IE)
3363             {
3364               if (tls_segment == NULL)
3365                 {
3366                   gold_assert(parameters->errors()->error_count() > 0
3367                               || issue_undefined_symbol_error(gsym));
3368                   return;
3369                 }
3370               value = target->got_plt_section()->address() + got_offset;
3371               this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment,
3372                                       rela, r_type, value, view, address,
3373                                       view_size);
3374               break;
3375             }
3376           else if (optimized_type == tls::TLSOPT_NONE)
3377             {
3378               if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
3379                 {
3380                   // Relocate the field with the offset of the pair of GOT
3381                   // entries.
3382                   value = target->got_plt_section()->address() + got_offset;
3383                   Relocate_functions<size, false>::pcrela32(view, value, addend,
3384                                                             address);
3385                 }
3386               break;
3387             }
3388         }
3389       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3390                              _("unsupported reloc %u"), r_type);
3391       break;
3392
3393     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
3394       if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
3395         {
3396           // See above comment for R_X86_64_TLSGD.
3397           optimized_type = tls::TLSOPT_NONE;
3398         }
3399       if (optimized_type == tls::TLSOPT_TO_LE)
3400         {
3401           if (tls_segment == NULL)
3402             {
3403               gold_assert(parameters->errors()->error_count() > 0
3404                           || issue_undefined_symbol_error(gsym));
3405               return;
3406             }
3407           this->tls_ld_to_le(relinfo, relnum, tls_segment, rela, r_type,
3408                              value, view, view_size);
3409           break;
3410         }
3411       else if (optimized_type == tls::TLSOPT_NONE)
3412         {
3413           // Relocate the field with the offset of the GOT entry for
3414           // the module index.
3415           unsigned int got_offset;
3416           got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
3417                         - target->got_size());
3418           value = target->got_plt_section()->address() + got_offset;
3419           Relocate_functions<size, false>::pcrela32(view, value, addend,
3420                                                     address);
3421           break;
3422         }
3423       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3424                              _("unsupported reloc %u"), r_type);
3425       break;
3426
3427     case elfcpp::R_X86_64_DTPOFF32:
3428       // This relocation type is used in debugging information.
3429       // In that case we need to not optimize the value.  If the
3430       // section is not executable, then we assume we should not
3431       // optimize this reloc.  See comments above for R_X86_64_TLSGD,
3432       // R_X86_64_GOTPC32_TLSDESC, R_X86_64_TLSDESC_CALL, and
3433       // R_X86_64_TLSLD.
3434       if (optimized_type == tls::TLSOPT_TO_LE && is_executable)
3435         {
3436           if (tls_segment == NULL)
3437             {
3438               gold_assert(parameters->errors()->error_count() > 0
3439                           || issue_undefined_symbol_error(gsym));
3440               return;
3441             }
3442           value -= tls_segment->memsz();
3443         }
3444       Relocate_functions<size, false>::rela32(view, value, addend);
3445       break;
3446
3447     case elfcpp::R_X86_64_DTPOFF64:
3448       // See R_X86_64_DTPOFF32, just above, for why we check for is_executable.
3449       if (optimized_type == tls::TLSOPT_TO_LE && is_executable)
3450         {
3451           if (tls_segment == NULL)
3452             {
3453               gold_assert(parameters->errors()->error_count() > 0
3454                           || issue_undefined_symbol_error(gsym));
3455               return;
3456             }
3457           value -= tls_segment->memsz();
3458         }
3459       Relocate_functions<size, false>::rela64(view, value, addend);
3460       break;
3461
3462     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
3463       if (optimized_type == tls::TLSOPT_TO_LE)
3464         {
3465           if (tls_segment == NULL)
3466             {
3467               gold_assert(parameters->errors()->error_count() > 0
3468                           || issue_undefined_symbol_error(gsym));
3469               return;
3470             }
3471           Target_x86_64<size>::Relocate::tls_ie_to_le(relinfo, relnum,
3472                                                       tls_segment, rela,
3473                                                       r_type, value, view,
3474                                                       view_size);
3475           break;
3476         }
3477       else if (optimized_type == tls::TLSOPT_NONE)
3478         {
3479           // Relocate the field with the offset of the GOT entry for
3480           // the tp-relative offset of the symbol.
3481           unsigned int got_offset;
3482           if (gsym != NULL)
3483             {
3484               gold_assert(gsym->has_got_offset(GOT_TYPE_TLS_OFFSET));
3485               got_offset = (gsym->got_offset(GOT_TYPE_TLS_OFFSET)
3486                             - target->got_size());
3487             }
3488           else
3489             {
3490               unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3491               gold_assert(object->local_has_got_offset(r_sym,
3492                                                        GOT_TYPE_TLS_OFFSET));
3493               got_offset = (object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET)
3494                             - target->got_size());
3495             }
3496           value = target->got_plt_section()->address() + got_offset;
3497           Relocate_functions<size, false>::pcrela32(view, value, addend,
3498                                                     address);
3499           break;
3500         }
3501       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3502                              _("unsupported reloc type %u"),
3503                              r_type);
3504       break;
3505
3506     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
3507       if (tls_segment == NULL)
3508         {
3509           gold_assert(parameters->errors()->error_count() > 0
3510                       || issue_undefined_symbol_error(gsym));
3511           return;
3512         }
3513       value -= tls_segment->memsz();
3514       Relocate_functions<size, false>::rela32(view, value, addend);
3515       break;
3516     }
3517 }
3518
3519 // Do a relocation in which we convert a TLS General-Dynamic to an
3520 // Initial-Exec.
3521
3522 template<int size>
3523 inline void
3524 Target_x86_64<size>::Relocate::tls_gd_to_ie(
3525     const Relocate_info<size, false>* relinfo,
3526     size_t relnum,
3527     Output_segment*,
3528     const elfcpp::Rela<size, false>& rela,
3529     unsigned int,
3530     typename elfcpp::Elf_types<size>::Elf_Addr value,
3531     unsigned char* view,
3532     typename elfcpp::Elf_types<size>::Elf_Addr address,
3533     section_size_type view_size)
3534 {
3535   // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
3536   // .word 0x6666; rex64; call __tls_get_addr
3537   // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
3538
3539   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -4);
3540   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
3541
3542   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3543                  (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
3544   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3545                  (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0));
3546
3547   memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0", 16);
3548
3549   const elfcpp::Elf_Xword addend = rela.get_r_addend();
3550   Relocate_functions<size, false>::pcrela32(view + 8, value, addend - 8,
3551                                             address);
3552
3553   // The next reloc should be a PLT32 reloc against __tls_get_addr.
3554   // We can skip it.
3555   this->skip_call_tls_get_addr_ = true;
3556 }
3557
3558 // Do a relocation in which we convert a TLS General-Dynamic to a
3559 // Local-Exec.
3560
3561 template<int size>
3562 inline void
3563 Target_x86_64<size>::Relocate::tls_gd_to_le(
3564     const Relocate_info<size, false>* relinfo,
3565     size_t relnum,
3566     Output_segment* tls_segment,
3567     const elfcpp::Rela<size, false>& rela,
3568     unsigned int,
3569     typename elfcpp::Elf_types<size>::Elf_Addr value,
3570     unsigned char* view,
3571     section_size_type view_size)
3572 {
3573   // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
3574   // .word 0x6666; rex64; call __tls_get_addr
3575   // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
3576
3577   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -4);
3578   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
3579
3580   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3581                  (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
3582   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3583                  (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0));
3584
3585   memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0", 16);
3586
3587   value -= tls_segment->memsz();
3588   Relocate_functions<size, false>::rela32(view + 8, value, 0);
3589
3590   // The next reloc should be a PLT32 reloc against __tls_get_addr.
3591   // We can skip it.
3592   this->skip_call_tls_get_addr_ = true;
3593 }
3594
3595 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
3596
3597 template<int size>
3598 inline void
3599 Target_x86_64<size>::Relocate::tls_desc_gd_to_ie(
3600     const Relocate_info<size, false>* relinfo,
3601     size_t relnum,
3602     Output_segment*,
3603     const elfcpp::Rela<size, false>& rela,
3604     unsigned int r_type,
3605     typename elfcpp::Elf_types<size>::Elf_Addr value,
3606     unsigned char* view,
3607     typename elfcpp::Elf_types<size>::Elf_Addr address,
3608     section_size_type view_size)
3609 {
3610   if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
3611     {
3612       // leaq foo@tlsdesc(%rip), %rax
3613       // ==> movq foo@gottpoff(%rip), %rax
3614       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
3615       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
3616       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3617                      view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05);
3618       view[-2] = 0x8b;
3619       const elfcpp::Elf_Xword addend = rela.get_r_addend();
3620       Relocate_functions<size, false>::pcrela32(view, value, addend, address);
3621     }
3622   else
3623     {
3624       // call *foo@tlscall(%rax)
3625       // ==> nop; nop
3626       gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
3627       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
3628       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3629                      view[0] == 0xff && view[1] == 0x10);
3630       view[0] = 0x66;
3631       view[1] = 0x90;
3632     }
3633 }
3634
3635 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
3636
3637 template<int size>
3638 inline void
3639 Target_x86_64<size>::Relocate::tls_desc_gd_to_le(
3640     const Relocate_info<size, false>* relinfo,
3641     size_t relnum,
3642     Output_segment* tls_segment,
3643     const elfcpp::Rela<size, false>& rela,
3644     unsigned int r_type,
3645     typename elfcpp::Elf_types<size>::Elf_Addr value,
3646     unsigned char* view,
3647     section_size_type view_size)
3648 {
3649   if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
3650     {
3651       // leaq foo@tlsdesc(%rip), %rax
3652       // ==> movq foo@tpoff, %rax
3653       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
3654       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
3655       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3656                      view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05);
3657       view[-2] = 0xc7;
3658       view[-1] = 0xc0;
3659       value -= tls_segment->memsz();
3660       Relocate_functions<size, false>::rela32(view, value, 0);
3661     }
3662   else
3663     {
3664       // call *foo@tlscall(%rax)
3665       // ==> nop; nop
3666       gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
3667       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
3668       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3669                      view[0] == 0xff && view[1] == 0x10);
3670       view[0] = 0x66;
3671       view[1] = 0x90;
3672     }
3673 }
3674
3675 template<int size>
3676 inline void
3677 Target_x86_64<size>::Relocate::tls_ld_to_le(
3678     const Relocate_info<size, false>* relinfo,
3679     size_t relnum,
3680     Output_segment*,
3681     const elfcpp::Rela<size, false>& rela,
3682     unsigned int,
3683     typename elfcpp::Elf_types<size>::Elf_Addr,
3684     unsigned char* view,
3685     section_size_type view_size)
3686 {
3687   // leaq foo@tlsld(%rip),%rdi; call __tls_get_addr@plt;
3688   // ... leq foo@dtpoff(%rax),%reg
3689   // ==> .word 0x6666; .byte 0x66; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
3690
3691   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
3692   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 9);
3693
3694   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3695                  view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x3d);
3696
3697   tls::check_tls(relinfo, relnum, rela.get_r_offset(), view[4] == 0xe8);
3698
3699   memcpy(view - 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12);
3700
3701   // The next reloc should be a PLT32 reloc against __tls_get_addr.
3702   // We can skip it.
3703   this->skip_call_tls_get_addr_ = true;
3704 }
3705
3706 // Do a relocation in which we convert a TLS Initial-Exec to a
3707 // Local-Exec.
3708
3709 template<int size>
3710 inline void
3711 Target_x86_64<size>::Relocate::tls_ie_to_le(
3712     const Relocate_info<size, false>* relinfo,
3713     size_t relnum,
3714     Output_segment* tls_segment,
3715     const elfcpp::Rela<size, false>& rela,
3716     unsigned int,
3717     typename elfcpp::Elf_types<size>::Elf_Addr value,
3718     unsigned char* view,
3719     section_size_type view_size)
3720 {
3721   // We need to examine the opcodes to figure out which instruction we
3722   // are looking at.
3723
3724   // movq foo@gottpoff(%rip),%reg  ==>  movq $YY,%reg
3725   // addq foo@gottpoff(%rip),%reg  ==>  addq $YY,%reg
3726
3727   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
3728   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
3729
3730   unsigned char op1 = view[-3];
3731   unsigned char op2 = view[-2];
3732   unsigned char op3 = view[-1];
3733   unsigned char reg = op3 >> 3;
3734
3735   if (op2 == 0x8b)
3736     {
3737       // movq
3738       if (op1 == 0x4c)
3739         view[-3] = 0x49;
3740       view[-2] = 0xc7;
3741       view[-1] = 0xc0 | reg;
3742     }
3743   else if (reg == 4)
3744     {
3745       // Special handling for %rsp.
3746       if (op1 == 0x4c)
3747         view[-3] = 0x49;
3748       view[-2] = 0x81;
3749       view[-1] = 0xc0 | reg;
3750     }
3751   else
3752     {
3753       // addq
3754       if (op1 == 0x4c)
3755         view[-3] = 0x4d;
3756       view[-2] = 0x8d;
3757       view[-1] = 0x80 | reg | (reg << 3);
3758     }
3759
3760   value -= tls_segment->memsz();
3761   Relocate_functions<size, false>::rela32(view, value, 0);
3762 }
3763
3764 // Relocate section data.
3765
3766 template<int size>
3767 void
3768 Target_x86_64<size>::relocate_section(
3769     const Relocate_info<size, false>* relinfo,
3770     unsigned int sh_type,
3771     const unsigned char* prelocs,
3772     size_t reloc_count,
3773     Output_section* output_section,
3774     bool needs_special_offset_handling,
3775     unsigned char* view,
3776     typename elfcpp::Elf_types<size>::Elf_Addr address,
3777     section_size_type view_size,
3778     const Reloc_symbol_changes* reloc_symbol_changes)
3779 {
3780   gold_assert(sh_type == elfcpp::SHT_RELA);
3781
3782   gold::relocate_section<size, false, Target_x86_64<size>, elfcpp::SHT_RELA,
3783                          typename Target_x86_64<size>::Relocate>(
3784     relinfo,
3785     this,
3786     prelocs,
3787     reloc_count,
3788     output_section,
3789     needs_special_offset_handling,
3790     view,
3791     address,
3792     view_size,
3793     reloc_symbol_changes);
3794 }
3795
3796 // Apply an incremental relocation.  Incremental relocations always refer
3797 // to global symbols.
3798
3799 template<int size>
3800 void
3801 Target_x86_64<size>::apply_relocation(
3802     const Relocate_info<size, false>* relinfo,
3803     typename elfcpp::Elf_types<size>::Elf_Addr r_offset,
3804     unsigned int r_type,
3805     typename elfcpp::Elf_types<size>::Elf_Swxword r_addend,
3806     const Symbol* gsym,
3807     unsigned char* view,
3808     typename elfcpp::Elf_types<size>::Elf_Addr address,
3809     section_size_type view_size)
3810 {
3811   gold::apply_relocation<size, false, Target_x86_64<size>,
3812                          typename Target_x86_64<size>::Relocate>(
3813     relinfo,
3814     this,
3815     r_offset,
3816     r_type,
3817     r_addend,
3818     gsym,
3819     view,
3820     address,
3821     view_size);
3822 }
3823
3824 // Return the size of a relocation while scanning during a relocatable
3825 // link.
3826
3827 template<int size>
3828 unsigned int
3829 Target_x86_64<size>::Relocatable_size_for_reloc::get_size_for_reloc(
3830     unsigned int r_type,
3831     Relobj* object)
3832 {
3833   switch (r_type)
3834     {
3835     case elfcpp::R_X86_64_NONE:
3836     case elfcpp::R_X86_64_GNU_VTINHERIT:
3837     case elfcpp::R_X86_64_GNU_VTENTRY:
3838     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
3839     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
3840     case elfcpp::R_X86_64_TLSDESC_CALL:
3841     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
3842     case elfcpp::R_X86_64_DTPOFF32:
3843     case elfcpp::R_X86_64_DTPOFF64:
3844     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
3845     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
3846       return 0;
3847
3848     case elfcpp::R_X86_64_64:
3849     case elfcpp::R_X86_64_PC64:
3850     case elfcpp::R_X86_64_GOTOFF64:
3851     case elfcpp::R_X86_64_GOTPC64:
3852     case elfcpp::R_X86_64_PLTOFF64:
3853     case elfcpp::R_X86_64_GOT64:
3854     case elfcpp::R_X86_64_GOTPCREL64:
3855     case elfcpp::R_X86_64_GOTPCREL:
3856     case elfcpp::R_X86_64_GOTPLT64:
3857       return 8;
3858
3859     case elfcpp::R_X86_64_32:
3860     case elfcpp::R_X86_64_32S:
3861     case elfcpp::R_X86_64_PC32:
3862     case elfcpp::R_X86_64_PLT32:
3863     case elfcpp::R_X86_64_GOTPC32:
3864     case elfcpp::R_X86_64_GOT32:
3865       return 4;
3866
3867     case elfcpp::R_X86_64_16:
3868     case elfcpp::R_X86_64_PC16:
3869       return 2;
3870
3871     case elfcpp::R_X86_64_8:
3872     case elfcpp::R_X86_64_PC8:
3873       return 1;
3874
3875     case elfcpp::R_X86_64_COPY:
3876     case elfcpp::R_X86_64_GLOB_DAT:
3877     case elfcpp::R_X86_64_JUMP_SLOT:
3878     case elfcpp::R_X86_64_RELATIVE:
3879     case elfcpp::R_X86_64_IRELATIVE:
3880       // These are outstanding tls relocs, which are unexpected when linking
3881     case elfcpp::R_X86_64_TPOFF64:
3882     case elfcpp::R_X86_64_DTPMOD64:
3883     case elfcpp::R_X86_64_TLSDESC:
3884       object->error(_("unexpected reloc %u in object file"), r_type);
3885       return 0;
3886
3887     case elfcpp::R_X86_64_SIZE32:
3888     case elfcpp::R_X86_64_SIZE64:
3889     default:
3890       object->error(_("unsupported reloc %u against local symbol"), r_type);
3891       return 0;
3892     }
3893 }
3894
3895 // Scan the relocs during a relocatable link.
3896
3897 template<int size>
3898 void
3899 Target_x86_64<size>::scan_relocatable_relocs(
3900     Symbol_table* symtab,
3901     Layout* layout,
3902     Sized_relobj_file<size, false>* object,
3903     unsigned int data_shndx,
3904     unsigned int sh_type,
3905     const unsigned char* prelocs,
3906     size_t reloc_count,
3907     Output_section* output_section,
3908     bool needs_special_offset_handling,
3909     size_t local_symbol_count,
3910     const unsigned char* plocal_symbols,
3911     Relocatable_relocs* rr)
3912 {
3913   gold_assert(sh_type == elfcpp::SHT_RELA);
3914
3915   typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_RELA,
3916     Relocatable_size_for_reloc> Scan_relocatable_relocs;
3917
3918   gold::scan_relocatable_relocs<size, false, elfcpp::SHT_RELA,
3919       Scan_relocatable_relocs>(
3920     symtab,
3921     layout,
3922     object,
3923     data_shndx,
3924     prelocs,
3925     reloc_count,
3926     output_section,
3927     needs_special_offset_handling,
3928     local_symbol_count,
3929     plocal_symbols,
3930     rr);
3931 }
3932
3933 // Relocate a section during a relocatable link.
3934
3935 template<int size>
3936 void
3937 Target_x86_64<size>::relocate_for_relocatable(
3938     const Relocate_info<size, false>* relinfo,
3939     unsigned int sh_type,
3940     const unsigned char* prelocs,
3941     size_t reloc_count,
3942     Output_section* output_section,
3943     off_t offset_in_output_section,
3944     const Relocatable_relocs* rr,
3945     unsigned char* view,
3946     typename elfcpp::Elf_types<size>::Elf_Addr view_address,
3947     section_size_type view_size,
3948     unsigned char* reloc_view,
3949     section_size_type reloc_view_size)
3950 {
3951   gold_assert(sh_type == elfcpp::SHT_RELA);
3952
3953   gold::relocate_for_relocatable<size, false, elfcpp::SHT_RELA>(
3954     relinfo,
3955     prelocs,
3956     reloc_count,
3957     output_section,
3958     offset_in_output_section,
3959     rr,
3960     view,
3961     view_address,
3962     view_size,
3963     reloc_view,
3964     reloc_view_size);
3965 }
3966
3967 // Return the value to use for a dynamic which requires special
3968 // treatment.  This is how we support equality comparisons of function
3969 // pointers across shared library boundaries, as described in the
3970 // processor specific ABI supplement.
3971
3972 template<int size>
3973 uint64_t
3974 Target_x86_64<size>::do_dynsym_value(const Symbol* gsym) const
3975 {
3976   gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
3977   return this->plt_address_for_global(gsym) + gsym->plt_offset();
3978 }
3979
3980 // Return a string used to fill a code section with nops to take up
3981 // the specified length.
3982
3983 template<int size>
3984 std::string
3985 Target_x86_64<size>::do_code_fill(section_size_type length) const
3986 {
3987   if (length >= 16)
3988     {
3989       // Build a jmpq instruction to skip over the bytes.
3990       unsigned char jmp[5];
3991       jmp[0] = 0xe9;
3992       elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
3993       return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
3994               + std::string(length - 5, '\0'));
3995     }
3996
3997   // Nop sequences of various lengths.
3998   const char nop1[1] = { '\x90' };                 // nop
3999   const char nop2[2] = { '\x66', '\x90' };         // xchg %ax %ax
4000   const char nop3[3] = { '\x0f', '\x1f', '\x00' }; // nop (%rax)
4001   const char nop4[4] = { '\x0f', '\x1f', '\x40',   // nop 0(%rax)
4002                          '\x00'};
4003   const char nop5[5] = { '\x0f', '\x1f', '\x44',   // nop 0(%rax,%rax,1)
4004                          '\x00', '\x00' };
4005   const char nop6[6] = { '\x66', '\x0f', '\x1f',   // nopw 0(%rax,%rax,1)
4006                          '\x44', '\x00', '\x00' };
4007   const char nop7[7] = { '\x0f', '\x1f', '\x80',   // nopl 0L(%rax)
4008                          '\x00', '\x00', '\x00',
4009                          '\x00' };
4010   const char nop8[8] = { '\x0f', '\x1f', '\x84',   // nopl 0L(%rax,%rax,1)
4011                          '\x00', '\x00', '\x00',
4012                          '\x00', '\x00' };
4013   const char nop9[9] = { '\x66', '\x0f', '\x1f',   // nopw 0L(%rax,%rax,1)
4014                          '\x84', '\x00', '\x00',
4015                          '\x00', '\x00', '\x00' };
4016   const char nop10[10] = { '\x66', '\x2e', '\x0f', // nopw %cs:0L(%rax,%rax,1)
4017                            '\x1f', '\x84', '\x00',
4018                            '\x00', '\x00', '\x00',
4019                            '\x00' };
4020   const char nop11[11] = { '\x66', '\x66', '\x2e', // data16
4021                            '\x0f', '\x1f', '\x84', // nopw %cs:0L(%rax,%rax,1)
4022                            '\x00', '\x00', '\x00',
4023                            '\x00', '\x00' };
4024   const char nop12[12] = { '\x66', '\x66', '\x66', // data16; data16
4025                            '\x2e', '\x0f', '\x1f', // nopw %cs:0L(%rax,%rax,1)
4026                            '\x84', '\x00', '\x00',
4027                            '\x00', '\x00', '\x00' };
4028   const char nop13[13] = { '\x66', '\x66', '\x66', // data16; data16; data16
4029                            '\x66', '\x2e', '\x0f', // nopw %cs:0L(%rax,%rax,1)
4030                            '\x1f', '\x84', '\x00',
4031                            '\x00', '\x00', '\x00',
4032                            '\x00' };
4033   const char nop14[14] = { '\x66', '\x66', '\x66', // data16; data16; data16
4034                            '\x66', '\x66', '\x2e', // data16
4035                            '\x0f', '\x1f', '\x84', // nopw %cs:0L(%rax,%rax,1)
4036                            '\x00', '\x00', '\x00',
4037                            '\x00', '\x00' };
4038   const char nop15[15] = { '\x66', '\x66', '\x66', // data16; data16; data16
4039                            '\x66', '\x66', '\x66', // data16; data16
4040                            '\x2e', '\x0f', '\x1f', // nopw %cs:0L(%rax,%rax,1)
4041                            '\x84', '\x00', '\x00',
4042                            '\x00', '\x00', '\x00' };
4043
4044   const char* nops[16] = {
4045     NULL,
4046     nop1, nop2, nop3, nop4, nop5, nop6, nop7,
4047     nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
4048   };
4049
4050   return std::string(nops[length], length);
4051 }
4052
4053 // Return the addend to use for a target specific relocation.  The
4054 // only target specific relocation is R_X86_64_TLSDESC for a local
4055 // symbol.  We want to set the addend is the offset of the local
4056 // symbol in the TLS segment.
4057
4058 template<int size>
4059 uint64_t
4060 Target_x86_64<size>::do_reloc_addend(void* arg, unsigned int r_type,
4061                                      uint64_t) const
4062 {
4063   gold_assert(r_type == elfcpp::R_X86_64_TLSDESC);
4064   uintptr_t intarg = reinterpret_cast<uintptr_t>(arg);
4065   gold_assert(intarg < this->tlsdesc_reloc_info_.size());
4066   const Tlsdesc_info& ti(this->tlsdesc_reloc_info_[intarg]);
4067   const Symbol_value<size>* psymval = ti.object->local_symbol(ti.r_sym);
4068   gold_assert(psymval->is_tls_symbol());
4069   // The value of a TLS symbol is the offset in the TLS segment.
4070   return psymval->value(ti.object, 0);
4071 }
4072
4073 // Return the value to use for the base of a DW_EH_PE_datarel offset
4074 // in an FDE.  Solaris and SVR4 use DW_EH_PE_datarel because their
4075 // assembler can not write out the difference between two labels in
4076 // different sections, so instead of using a pc-relative value they
4077 // use an offset from the GOT.
4078
4079 template<int size>
4080 uint64_t
4081 Target_x86_64<size>::do_ehframe_datarel_base() const
4082 {
4083   gold_assert(this->global_offset_table_ != NULL);
4084   Symbol* sym = this->global_offset_table_;
4085   Sized_symbol<size>* ssym = static_cast<Sized_symbol<size>*>(sym);
4086   return ssym->value();
4087 }
4088
4089 // FNOFFSET in section SHNDX in OBJECT is the start of a function
4090 // compiled with -fsplit-stack.  The function calls non-split-stack
4091 // code.  We have to change the function so that it always ensures
4092 // that it has enough stack space to run some random function.
4093
4094 template<int size>
4095 void
4096 Target_x86_64<size>::do_calls_non_split(Relobj* object, unsigned int shndx,
4097                                         section_offset_type fnoffset,
4098                                         section_size_type fnsize,
4099                                         unsigned char* view,
4100                                         section_size_type view_size,
4101                                         std::string* from,
4102                                         std::string* to) const
4103 {
4104   // The function starts with a comparison of the stack pointer and a
4105   // field in the TCB.  This is followed by a jump.
4106
4107   // cmp %fs:NN,%rsp
4108   if (this->match_view(view, view_size, fnoffset, "\x64\x48\x3b\x24\x25", 5)
4109       && fnsize > 9)
4110     {
4111       // We will call __morestack if the carry flag is set after this
4112       // comparison.  We turn the comparison into an stc instruction
4113       // and some nops.
4114       view[fnoffset] = '\xf9';
4115       this->set_view_to_nop(view, view_size, fnoffset + 1, 8);
4116     }
4117   // lea NN(%rsp),%r10
4118   // lea NN(%rsp),%r11
4119   else if ((this->match_view(view, view_size, fnoffset,
4120                              "\x4c\x8d\x94\x24", 4)
4121             || this->match_view(view, view_size, fnoffset,
4122                                 "\x4c\x8d\x9c\x24", 4))
4123            && fnsize > 8)
4124     {
4125       // This is loading an offset from the stack pointer for a
4126       // comparison.  The offset is negative, so we decrease the
4127       // offset by the amount of space we need for the stack.  This
4128       // means we will avoid calling __morestack if there happens to
4129       // be plenty of space on the stack already.
4130       unsigned char* pval = view + fnoffset + 4;
4131       uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
4132       val -= parameters->options().split_stack_adjust_size();
4133       elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
4134     }
4135   else
4136     {
4137       if (!object->has_no_split_stack())
4138         object->error(_("failed to match split-stack sequence at "
4139                         "section %u offset %0zx"),
4140                       shndx, static_cast<size_t>(fnoffset));
4141       return;
4142     }
4143
4144   // We have to change the function so that it calls
4145   // __morestack_non_split instead of __morestack.  The former will
4146   // allocate additional stack space.
4147   *from = "__morestack";
4148   *to = "__morestack_non_split";
4149 }
4150
4151 // The selector for x86_64 object files.
4152
4153 template<int size>
4154 class Target_selector_x86_64 : public Target_selector_freebsd
4155 {
4156 public:
4157   Target_selector_x86_64()
4158     : Target_selector_freebsd(elfcpp::EM_X86_64, size, false,
4159                               (size == 64
4160                                ? "elf64-x86-64" : "elf32-x86-64"),
4161                               (size == 64
4162                                ? "elf64-x86-64-freebsd"
4163                                : "elf32-x86-64-freebsd"),
4164                               (size == 64 ? "elf_x86_64" : "elf32_x86_64"))
4165   { }
4166
4167   Target*
4168   do_instantiate_target()
4169   { return new Target_x86_64<size>(); }
4170
4171 };
4172
4173 Target_selector_x86_64<64> target_selector_x86_64;
4174 Target_selector_x86_64<32> target_selector_x32;
4175
4176 } // End anonymous namespace.