gold/x86_64.cc

   1 // x86_64.cc -- x86_64 target support for gold.
   2
   3 // Copyright (C) 2006-2016 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 "nacl.h"
  43 #include "gc.h"
  44 #include "icf.h"
  45
  46 namespace
  47 {
  48
  49 using namespace gold;
  50
  51 // A class to handle the .got.plt section.
  52
  53 class Output_data_got_plt_x86_64 : public Output_section_data_build
  54 {
  55  public:
  56   Output_data_got_plt_x86_64(Layout* layout)
  57     : Output_section_data_build(8),
  58       layout_(layout)
  59   { }
  60
  61   Output_data_got_plt_x86_64(Layout* layout, off_t data_size)
  62     : Output_section_data_build(data_size, 8),
  63       layout_(layout)
  64   { }
  65
  66  protected:
  67   // Write out the PLT data.
  68   void
  69   do_write(Output_file*);
  70
  71   // Write to a map file.
  72   void
  73   do_print_to_mapfile(Mapfile* mapfile) const
  74   { mapfile->print_output_data(this, "** GOT PLT"); }
  75
  76  private:
  77   // A pointer to the Layout class, so that we can find the .dynamic
  78   // section when we write out the GOT PLT section.
  79   Layout* layout_;
  80 };
  81
  82 // A class to handle the PLT data.
  83 // This is an abstract base class that handles most of the linker details
  84 // but does not know the actual contents of PLT entries.  The derived
  85 // classes below fill in those details.
  86
  87 template<int size>
  88 class Output_data_plt_x86_64 : public Output_section_data
  89 {
  90  public:
  91   typedef Output_data_reloc<elfcpp::SHT_RELA, true, size, false> Reloc_section;
  92
  93   Output_data_plt_x86_64(Layout* layout, uint64_t addralign,
  94                          Output_data_got<64, false>* got,
  95                          Output_data_got_plt_x86_64* got_plt,
  96                          Output_data_space* got_irelative)
  97     : Output_section_data(addralign), tlsdesc_rel_(NULL),
  98       irelative_rel_(NULL), got_(got), got_plt_(got_plt),
  99       got_irelative_(got_irelative), count_(0), irelative_count_(0),
 100       tlsdesc_got_offset_(-1U), free_list_()
 101   { this->init(layout); }
 102
 103   Output_data_plt_x86_64(Layout* layout, uint64_t plt_entry_size,
 104                          Output_data_got<64, false>* got,
 105                          Output_data_got_plt_x86_64* got_plt,
 106                          Output_data_space* got_irelative,
 107                          unsigned int plt_count)
 108     : Output_section_data((plt_count + 1) * plt_entry_size,
 109                           plt_entry_size, false),
 110       tlsdesc_rel_(NULL), irelative_rel_(NULL), got_(got),
 111       got_plt_(got_plt), got_irelative_(got_irelative), count_(plt_count),
 112       irelative_count_(0), tlsdesc_got_offset_(-1U), free_list_()
 113   {
 114     this->init(layout);
 115
 116     // Initialize the free list and reserve the first entry.
 117     this->free_list_.init((plt_count + 1) * plt_entry_size, false);
 118     this->free_list_.remove(0, plt_entry_size);
 119   }
 120
 121   // Initialize the PLT section.
 122   void
 123   init(Layout* layout);
 124
 125   // Add an entry to the PLT.
 126   void
 127   add_entry(Symbol_table*, Layout*, Symbol* gsym);
 128
 129   // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
 130   unsigned int
 131   add_local_ifunc_entry(Symbol_table* symtab, Layout*,
 132                         Sized_relobj_file<size, false>* relobj,
 133                         unsigned int local_sym_index);
 134
 135   // Add the relocation for a PLT entry.
 136   void
 137   add_relocation(Symbol_table*, Layout*, Symbol* gsym,
 138                  unsigned int got_offset);
 139
 140   // Add the reserved TLSDESC_PLT entry to the PLT.
 141   void
 142   reserve_tlsdesc_entry(unsigned int got_offset)
 143   { this->tlsdesc_got_offset_ = got_offset; }
 144
 145   // Return true if a TLSDESC_PLT entry has been reserved.
 146   bool
 147   has_tlsdesc_entry() const
 148   { return this->tlsdesc_got_offset_ != -1U; }
 149
 150   // Return the GOT offset for the reserved TLSDESC_PLT entry.
 151   unsigned int
 152   get_tlsdesc_got_offset() const
 153   { return this->tlsdesc_got_offset_; }
 154
 155   // Return the offset of the reserved TLSDESC_PLT entry.
 156   unsigned int
 157   get_tlsdesc_plt_offset() const
 158   {
 159     return ((this->count_ + this->irelative_count_ + 1)
 160             * this->get_plt_entry_size());
 161   }
 162
 163   // Return the .rela.plt section data.
 164   Reloc_section*
 165   rela_plt()
 166   { return this->rel_; }
 167
 168   // Return where the TLSDESC relocations should go.
 169   Reloc_section*
 170   rela_tlsdesc(Layout*);
 171
 172   // Return where the IRELATIVE relocations should go in the PLT
 173   // relocations.
 174   Reloc_section*
 175   rela_irelative(Symbol_table*, Layout*);
 176
 177   // Return whether we created a section for IRELATIVE relocations.
 178   bool
 179   has_irelative_section() const
 180   { return this->irelative_rel_ != NULL; }
 181
 182   // Return the number of PLT entries.
 183   unsigned int
 184   entry_count() const
 185   { return this->count_ + this->irelative_count_; }
 186
 187   // Return the offset of the first non-reserved PLT entry.
 188   unsigned int
 189   first_plt_entry_offset()
 190   { return this->get_plt_entry_size(); }
 191
 192   // Return the size of a PLT entry.
 193   unsigned int
 194   get_plt_entry_size() const
 195   { return this->do_get_plt_entry_size(); }
 196
 197   // Reserve a slot in the PLT for an existing symbol in an incremental update.
 198   void
 199   reserve_slot(unsigned int plt_index)
 200   {
 201     this->free_list_.remove((plt_index + 1) * this->get_plt_entry_size(),
 202                             (plt_index + 2) * this->get_plt_entry_size());
 203   }
 204
 205   // Return the PLT address to use for a global symbol.
 206   uint64_t
 207   address_for_global(const Symbol*);
 208
 209   // Return the PLT address to use for a local symbol.
 210   uint64_t
 211   address_for_local(const Relobj*, unsigned int symndx);
 212
 213   // Add .eh_frame information for the PLT.
 214   void
 215   add_eh_frame(Layout* layout)
 216   { this->do_add_eh_frame(layout); }
 217
 218  protected:
 219   // Fill in the first PLT entry.
 220   void
 221   fill_first_plt_entry(unsigned char* pov,
 222                        typename elfcpp::Elf_types<size>::Elf_Addr got_address,
 223                        typename elfcpp::Elf_types<size>::Elf_Addr plt_address)
 224   { this->do_fill_first_plt_entry(pov, got_address, plt_address); }
 225
 226   // Fill in a normal PLT entry.  Returns the offset into the entry that
 227   // should be the initial GOT slot value.
 228   unsigned int
 229   fill_plt_entry(unsigned char* pov,
 230                  typename elfcpp::Elf_types<size>::Elf_Addr got_address,
 231                  typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
 232                  unsigned int got_offset,
 233                  unsigned int plt_offset,
 234                  unsigned int plt_index)
 235   {
 236     return this->do_fill_plt_entry(pov, got_address, plt_address,
 237                                    got_offset, plt_offset, plt_index);
 238   }
 239
 240   // Fill in the reserved TLSDESC PLT entry.
 241   void
 242   fill_tlsdesc_entry(unsigned char* pov,
 243                      typename elfcpp::Elf_types<size>::Elf_Addr got_address,
 244                      typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
 245                      typename elfcpp::Elf_types<size>::Elf_Addr got_base,
 246                      unsigned int tlsdesc_got_offset,
 247                      unsigned int plt_offset)
 248   {
 249     this->do_fill_tlsdesc_entry(pov, got_address, plt_address, got_base,
 250                                 tlsdesc_got_offset, plt_offset);
 251   }
 252
 253   virtual unsigned int
 254   do_get_plt_entry_size() const = 0;
 255
 256   virtual void
 257   do_fill_first_plt_entry(unsigned char* pov,
 258                           typename elfcpp::Elf_types<size>::Elf_Addr got_addr,
 259                           typename elfcpp::Elf_types<size>::Elf_Addr plt_addr)
 260     = 0;
 261
 262   virtual unsigned int
 263   do_fill_plt_entry(unsigned char* pov,
 264                     typename elfcpp::Elf_types<size>::Elf_Addr got_address,
 265                     typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
 266                     unsigned int got_offset,
 267                     unsigned int plt_offset,
 268                     unsigned int plt_index) = 0;
 269
 270   virtual void
 271   do_fill_tlsdesc_entry(unsigned char* pov,
 272                         typename elfcpp::Elf_types<size>::Elf_Addr got_address,
 273                         typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
 274                         typename elfcpp::Elf_types<size>::Elf_Addr got_base,
 275                         unsigned int tlsdesc_got_offset,
 276                         unsigned int plt_offset) = 0;
 277
 278   virtual void
 279   do_add_eh_frame(Layout* layout) = 0;
 280
 281   void
 282   do_adjust_output_section(Output_section* os);
 283
 284   // Write to a map file.
 285   void
 286   do_print_to_mapfile(Mapfile* mapfile) const
 287   { mapfile->print_output_data(this, _("** PLT")); }
 288
 289   // The CIE of the .eh_frame unwind information for the PLT.
 290   static const int plt_eh_frame_cie_size = 16;
 291   static const unsigned char plt_eh_frame_cie[plt_eh_frame_cie_size];
 292
 293  private:
 294   // Set the final size.
 295   void
 296   set_final_data_size();
 297
 298   // Write out the PLT data.
 299   void
 300   do_write(Output_file*);
 301
 302   // The reloc section.
 303   Reloc_section* rel_;
 304   // The TLSDESC relocs, if necessary.  These must follow the regular
 305   // PLT relocs.
 306   Reloc_section* tlsdesc_rel_;
 307   // The IRELATIVE relocs, if necessary.  These must follow the
 308   // regular PLT relocations and the TLSDESC relocations.
 309   Reloc_section* irelative_rel_;
 310   // The .got section.
 311   Output_data_got<64, false>* got_;
 312   // The .got.plt section.
 313   Output_data_got_plt_x86_64* got_plt_;
 314   // The part of the .got.plt section used for IRELATIVE relocs.
 315   Output_data_space* got_irelative_;
 316   // The number of PLT entries.
 317   unsigned int count_;
 318   // Number of PLT entries with R_X86_64_IRELATIVE relocs.  These
 319   // follow the regular PLT entries.
 320   unsigned int irelative_count_;
 321   // Offset of the reserved TLSDESC_GOT entry when needed.
 322   unsigned int tlsdesc_got_offset_;
 323   // List of available regions within the section, for incremental
 324   // update links.
 325   Free_list free_list_;
 326 };
 327
 328 template<int size>
 329 class Output_data_plt_x86_64_standard : public Output_data_plt_x86_64<size>
 330 {
 331  public:
 332   Output_data_plt_x86_64_standard(Layout* layout,
 333                                   Output_data_got<64, false>* got,
 334                                   Output_data_got_plt_x86_64* got_plt,
 335                                   Output_data_space* got_irelative)
 336     : Output_data_plt_x86_64<size>(layout, plt_entry_size,
 337                                    got, got_plt, got_irelative)
 338   { }
 339
 340   Output_data_plt_x86_64_standard(Layout* layout,
 341                                   Output_data_got<64, false>* got,
 342                                   Output_data_got_plt_x86_64* got_plt,
 343                                   Output_data_space* got_irelative,
 344                                   unsigned int plt_count)
 345     : Output_data_plt_x86_64<size>(layout, plt_entry_size,
 346                                    got, got_plt, got_irelative,
 347                                    plt_count)
 348   { }
 349
 350  protected:
 351   virtual unsigned int
 352   do_get_plt_entry_size() const
 353   { return plt_entry_size; }
 354
 355   virtual void
 356   do_add_eh_frame(Layout* layout)
 357   {
 358     layout->add_eh_frame_for_plt(this,
 359                                  this->plt_eh_frame_cie,
 360                                  this->plt_eh_frame_cie_size,
 361                                  plt_eh_frame_fde,
 362                                  plt_eh_frame_fde_size);
 363   }
 364
 365   virtual void
 366   do_fill_first_plt_entry(unsigned char* pov,
 367                           typename elfcpp::Elf_types<size>::Elf_Addr got_addr,
 368                           typename elfcpp::Elf_types<size>::Elf_Addr plt_addr);
 369
 370   virtual unsigned int
 371   do_fill_plt_entry(unsigned char* pov,
 372                     typename elfcpp::Elf_types<size>::Elf_Addr got_address,
 373                     typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
 374                     unsigned int got_offset,
 375                     unsigned int plt_offset,
 376                     unsigned int plt_index);
 377
 378   virtual void
 379   do_fill_tlsdesc_entry(unsigned char* pov,
 380                         typename elfcpp::Elf_types<size>::Elf_Addr got_address,
 381                         typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
 382                         typename elfcpp::Elf_types<size>::Elf_Addr got_base,
 383                         unsigned int tlsdesc_got_offset,
 384                         unsigned int plt_offset);
 385
 386  private:
 387   // The size of an entry in the PLT.
 388   static const int plt_entry_size = 16;
 389
 390   // The first entry in the PLT.
 391   // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
 392   // procedure linkage table for both programs and shared objects."
 393   static const unsigned char first_plt_entry[plt_entry_size];
 394
 395   // Other entries in the PLT for an executable.
 396   static const unsigned char plt_entry[plt_entry_size];
 397
 398   // The reserved TLSDESC entry in the PLT for an executable.
 399   static const unsigned char tlsdesc_plt_entry[plt_entry_size];
 400
 401   // The .eh_frame unwind information for the PLT.
 402   static const int plt_eh_frame_fde_size = 32;
 403   static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
 404 };
 405
 406 // The x86_64 target class.
 407 // See the ABI at
 408 //   http://www.x86-64.org/documentation/abi.pdf
 409 // TLS info comes from
 410 //   http://people.redhat.com/drepper/tls.pdf
 411 //   http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
 412
 413 template<int size>
 414 class Target_x86_64 : public Sized_target<size, false>
 415 {
 416  public:
 417   // In the x86_64 ABI (p 68), it says "The AMD64 ABI architectures
 418   // uses only Elf64_Rela relocation entries with explicit addends."
 419   typedef Output_data_reloc<elfcpp::SHT_RELA, true, size, false> Reloc_section;
 420
 421   Target_x86_64(const Target::Target_info* info = &x86_64_info)
 422     : Sized_target<size, false>(info),
 423       got_(NULL), plt_(NULL), got_plt_(NULL), got_irelative_(NULL),
 424       got_tlsdesc_(NULL), global_offset_table_(NULL), rela_dyn_(NULL),
 425       rela_irelative_(NULL), copy_relocs_(elfcpp::R_X86_64_COPY),
 426       got_mod_index_offset_(-1U), tlsdesc_reloc_info_(),
 427       tls_base_symbol_defined_(false)
 428   { }
 429
 430   // Hook for a new output section.
 431   void
 432   do_new_output_section(Output_section*) const;
 433
 434   // Scan the relocations to look for symbol adjustments.
 435   void
 436   gc_process_relocs(Symbol_table* symtab,
 437                     Layout* layout,
 438                     Sized_relobj_file<size, false>* object,
 439                     unsigned int data_shndx,
 440                     unsigned int sh_type,
 441                     const unsigned char* prelocs,
 442                     size_t reloc_count,
 443                     Output_section* output_section,
 444                     bool needs_special_offset_handling,
 445                     size_t local_symbol_count,
 446                     const unsigned char* plocal_symbols);
 447
 448   // Scan the relocations to look for symbol adjustments.
 449   void
 450   scan_relocs(Symbol_table* symtab,
 451               Layout* layout,
 452               Sized_relobj_file<size, false>* object,
 453               unsigned int data_shndx,
 454               unsigned int sh_type,
 455               const unsigned char* prelocs,
 456               size_t reloc_count,
 457               Output_section* output_section,
 458               bool needs_special_offset_handling,
 459               size_t local_symbol_count,
 460               const unsigned char* plocal_symbols);
 461
 462   // Finalize the sections.
 463   void
 464   do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
 465
 466   // Return the value to use for a dynamic which requires special
 467   // treatment.
 468   uint64_t
 469   do_dynsym_value(const Symbol*) const;
 470
 471   // Relocate a section.
 472   void
 473   relocate_section(const Relocate_info<size, false>*,
 474                    unsigned int sh_type,
 475                    const unsigned char* prelocs,
 476                    size_t reloc_count,
 477                    Output_section* output_section,
 478                    bool needs_special_offset_handling,
 479                    unsigned char* view,
 480                    typename elfcpp::Elf_types<size>::Elf_Addr view_address,
 481                    section_size_type view_size,
 482                    const Reloc_symbol_changes*);
 483
 484   // Scan the relocs during a relocatable link.
 485   void
 486   scan_relocatable_relocs(Symbol_table* symtab,
 487                           Layout* layout,
 488                           Sized_relobj_file<size, false>* object,
 489                           unsigned int data_shndx,
 490                           unsigned int sh_type,
 491                           const unsigned char* prelocs,
 492                           size_t reloc_count,
 493                           Output_section* output_section,
 494                           bool needs_special_offset_handling,
 495                           size_t local_symbol_count,
 496                           const unsigned char* plocal_symbols,
 497                           Relocatable_relocs*);
 498
 499   // Scan the relocs for --emit-relocs.
 500   void
 501   emit_relocs_scan(Symbol_table* symtab,
 502                    Layout* layout,
 503                    Sized_relobj_file<size, false>* object,
 504                    unsigned int data_shndx,
 505                    unsigned int sh_type,
 506                    const unsigned char* prelocs,
 507                    size_t reloc_count,
 508                    Output_section* output_section,
 509                    bool needs_special_offset_handling,
 510                    size_t local_symbol_count,
 511                    const unsigned char* plocal_syms,
 512                    Relocatable_relocs* rr);
 513
 514   // Emit relocations for a section.
 515   void
 516   relocate_relocs(
 517       const Relocate_info<size, false>*,
 518       unsigned int sh_type,
 519       const unsigned char* prelocs,
 520       size_t reloc_count,
 521       Output_section* output_section,
 522       typename elfcpp::Elf_types<size>::Elf_Off offset_in_output_section,
 523       unsigned char* view,
 524       typename elfcpp::Elf_types<size>::Elf_Addr view_address,
 525       section_size_type view_size,
 526       unsigned char* reloc_view,
 527       section_size_type reloc_view_size);
 528
 529   // Return a string used to fill a code section with nops.
 530   std::string
 531   do_code_fill(section_size_type length) const;
 532
 533   // Return whether SYM is defined by the ABI.
 534   bool
 535   do_is_defined_by_abi(const Symbol* sym) const
 536   { return strcmp(sym->name(), "__tls_get_addr") == 0; }
 537
 538   // Return the symbol index to use for a target specific relocation.
 539   // The only target specific relocation is R_X86_64_TLSDESC for a
 540   // local symbol, which is an absolute reloc.
 541   unsigned int
 542   do_reloc_symbol_index(void*, unsigned int r_type) const
 543   {
 544     gold_assert(r_type == elfcpp::R_X86_64_TLSDESC);
 545     return 0;
 546   }
 547
 548   // Return the addend to use for a target specific relocation.
 549   uint64_t
 550   do_reloc_addend(void* arg, unsigned int r_type, uint64_t addend) const;
 551
 552   // Return the PLT section.
 553   uint64_t
 554   do_plt_address_for_global(const Symbol* gsym) const
 555   { return this->plt_section()->address_for_global(gsym); }
 556
 557   uint64_t
 558   do_plt_address_for_local(const Relobj* relobj, unsigned int symndx) const
 559   { return this->plt_section()->address_for_local(relobj, symndx); }
 560
 561   // This function should be defined in targets that can use relocation
 562   // types to determine (implemented in local_reloc_may_be_function_pointer
 563   // and global_reloc_may_be_function_pointer)
 564   // if a function's pointer is taken.  ICF uses this in safe mode to only
 565   // fold those functions whose pointer is defintely not taken.  For x86_64
 566   // pie binaries, safe ICF cannot be done by looking at relocation types.
 567   bool
 568   do_can_check_for_function_pointers() const
 569   { return !parameters->options().pie(); }
 570
 571   // Return the base for a DW_EH_PE_datarel encoding.
 572   uint64_t
 573   do_ehframe_datarel_base() const;
 574
 575   // Adjust -fsplit-stack code which calls non-split-stack code.
 576   void
 577   do_calls_non_split(Relobj* object, unsigned int shndx,
 578                      section_offset_type fnoffset, section_size_type fnsize,
 579                      const unsigned char* prelocs, size_t reloc_count,
 580                      unsigned char* view, section_size_type view_size,
 581                      std::string* from, std::string* to) const;
 582
 583   // Return the size of the GOT section.
 584   section_size_type
 585   got_size() const
 586   {
 587     gold_assert(this->got_ != NULL);
 588     return this->got_->data_size();
 589   }
 590
 591   // Return the number of entries in the GOT.
 592   unsigned int
 593   got_entry_count() const
 594   {
 595     if (this->got_ == NULL)
 596       return 0;
 597     return this->got_size() / 8;
 598   }
 599
 600   // Return the number of entries in the PLT.
 601   unsigned int
 602   plt_entry_count() const;
 603
 604   // Return the offset of the first non-reserved PLT entry.
 605   unsigned int
 606   first_plt_entry_offset() const;
 607
 608   // Return the size of each PLT entry.
 609   unsigned int
 610   plt_entry_size() const;
 611
 612   // Return the size of each GOT entry.
 613   unsigned int
 614   got_entry_size() const
 615   { return 8; };
 616
 617   // Create the GOT section for an incremental update.
 618   Output_data_got_base*
 619   init_got_plt_for_update(Symbol_table* symtab,
 620                           Layout* layout,
 621                           unsigned int got_count,
 622                           unsigned int plt_count);
 623
 624   // Reserve a GOT entry for a local symbol, and regenerate any
 625   // necessary dynamic relocations.
 626   void
 627   reserve_local_got_entry(unsigned int got_index,
 628                           Sized_relobj<size, false>* obj,
 629                           unsigned int r_sym,
 630                           unsigned int got_type);
 631
 632   // Reserve a GOT entry for a global symbol, and regenerate any
 633   // necessary dynamic relocations.
 634   void
 635   reserve_global_got_entry(unsigned int got_index, Symbol* gsym,
 636                            unsigned int got_type);
 637
 638   // Register an existing PLT entry for a global symbol.
 639   void
 640   register_global_plt_entry(Symbol_table*, Layout*, unsigned int plt_index,
 641                             Symbol* gsym);
 642
 643   // Force a COPY relocation for a given symbol.
 644   void
 645   emit_copy_reloc(Symbol_table*, Symbol*, Output_section*, off_t);
 646
 647   // Apply an incremental relocation.
 648   void
 649   apply_relocation(const Relocate_info<size, false>* relinfo,
 650                    typename elfcpp::Elf_types<size>::Elf_Addr r_offset,
 651                    unsigned int r_type,
 652                    typename elfcpp::Elf_types<size>::Elf_Swxword r_addend,
 653                    const Symbol* gsym,
 654                    unsigned char* view,
 655                    typename elfcpp::Elf_types<size>::Elf_Addr address,
 656                    section_size_type view_size);
 657
 658   // Add a new reloc argument, returning the index in the vector.
 659   size_t
 660   add_tlsdesc_info(Sized_relobj_file<size, false>* object, unsigned int r_sym)
 661   {
 662     this->tlsdesc_reloc_info_.push_back(Tlsdesc_info(object, r_sym));
 663     return this->tlsdesc_reloc_info_.size() - 1;
 664   }
 665
 666   Output_data_plt_x86_64<size>*
 667   make_data_plt(Layout* layout,
 668                 Output_data_got<64, false>* got,
 669                 Output_data_got_plt_x86_64* got_plt,
 670                 Output_data_space* got_irelative)
 671   {
 672     return this->do_make_data_plt(layout, got, got_plt, got_irelative);
 673   }
 674
 675   Output_data_plt_x86_64<size>*
 676   make_data_plt(Layout* layout,
 677                 Output_data_got<64, false>* got,
 678                 Output_data_got_plt_x86_64* got_plt,
 679                 Output_data_space* got_irelative,
 680                 unsigned int plt_count)
 681   {
 682     return this->do_make_data_plt(layout, got, got_plt, got_irelative,
 683                                   plt_count);
 684   }
 685
 686   virtual Output_data_plt_x86_64<size>*
 687   do_make_data_plt(Layout* layout,
 688                    Output_data_got<64, false>* got,
 689                    Output_data_got_plt_x86_64* got_plt,
 690                    Output_data_space* got_irelative)
 691   {
 692     return new Output_data_plt_x86_64_standard<size>(layout, got, got_plt,
 693                                                      got_irelative);
 694   }
 695
 696   virtual Output_data_plt_x86_64<size>*
 697   do_make_data_plt(Layout* layout,
 698                    Output_data_got<64, false>* got,
 699                    Output_data_got_plt_x86_64* got_plt,
 700                    Output_data_space* got_irelative,
 701                    unsigned int plt_count)
 702   {
 703     return new Output_data_plt_x86_64_standard<size>(layout, got, got_plt,
 704                                                      got_irelative,
 705                                                      plt_count);
 706   }
 707
 708  private:
 709   // The class which scans relocations.
 710   class Scan
 711   {
 712   public:
 713     Scan()
 714       : issued_non_pic_error_(false)
 715     { }
 716
 717     static inline int
 718     get_reference_flags(unsigned int r_type);
 719
 720     inline void
 721     local(Symbol_table* symtab, Layout* layout, Target_x86_64* target,
 722           Sized_relobj_file<size, false>* object,
 723           unsigned int data_shndx,
 724           Output_section* output_section,
 725           const elfcpp::Rela<size, false>& reloc, unsigned int r_type,
 726           const elfcpp::Sym<size, false>& lsym,
 727           bool is_discarded);
 728
 729     inline void
 730     global(Symbol_table* symtab, Layout* layout, Target_x86_64* target,
 731            Sized_relobj_file<size, false>* object,
 732            unsigned int data_shndx,
 733            Output_section* output_section,
 734            const elfcpp::Rela<size, false>& reloc, unsigned int r_type,
 735            Symbol* gsym);
 736
 737     inline bool
 738     local_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
 739                                         Target_x86_64* target,
 740                                         Sized_relobj_file<size, false>* object,
 741                                         unsigned int data_shndx,
 742                                         Output_section* output_section,
 743                                         const elfcpp::Rela<size, false>& reloc,
 744                                         unsigned int r_type,
 745                                         const elfcpp::Sym<size, false>& lsym);
 746
 747     inline bool
 748     global_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
 749                                          Target_x86_64* target,
 750                                          Sized_relobj_file<size, false>* object,
 751                                          unsigned int data_shndx,
 752                                          Output_section* output_section,
 753                                          const elfcpp::Rela<size, false>& reloc,
 754                                          unsigned int r_type,
 755                                          Symbol* gsym);
 756
 757   private:
 758     static void
 759     unsupported_reloc_local(Sized_relobj_file<size, false>*,
 760                             unsigned int r_type);
 761
 762     static void
 763     unsupported_reloc_global(Sized_relobj_file<size, false>*,
 764                              unsigned int r_type, Symbol*);
 765
 766     void
 767     check_non_pic(Relobj*, unsigned int r_type, Symbol*);
 768
 769     inline bool
 770     possible_function_pointer_reloc(unsigned int r_type);
 771
 772     bool
 773     reloc_needs_plt_for_ifunc(Sized_relobj_file<size, false>*,
 774                               unsigned int r_type);
 775
 776     // Whether we have issued an error about a non-PIC compilation.
 777     bool issued_non_pic_error_;
 778   };
 779
 780   // The class which implements relocation.
 781   class Relocate
 782   {
 783    public:
 784     Relocate()
 785       : skip_call_tls_get_addr_(false)
 786     { }
 787
 788     ~Relocate()
 789     {
 790       if (this->skip_call_tls_get_addr_)
 791         {
 792           // FIXME: This needs to specify the location somehow.
 793           gold_error(_("missing expected TLS relocation"));
 794         }
 795     }
 796
 797     // Do a relocation.  Return false if the caller should not issue
 798     // any warnings about this relocation.
 799     inline bool
 800     relocate(const Relocate_info<size, false>*, unsigned int,
 801              Target_x86_64*, Output_section*, size_t, const unsigned char*,
 802              const Sized_symbol<size>*, const Symbol_value<size>*,
 803              unsigned char*, typename elfcpp::Elf_types<size>::Elf_Addr,
 804              section_size_type);
 805
 806    private:
 807     // Do a TLS relocation.
 808     inline void
 809     relocate_tls(const Relocate_info<size, false>*, Target_x86_64*,
 810                  size_t relnum, const elfcpp::Rela<size, false>&,
 811                  unsigned int r_type, const Sized_symbol<size>*,
 812                  const Symbol_value<size>*,
 813                  unsigned char*, typename elfcpp::Elf_types<size>::Elf_Addr,
 814                  section_size_type);
 815
 816     // Do a TLS General-Dynamic to Initial-Exec transition.
 817     inline void
 818     tls_gd_to_ie(const Relocate_info<size, false>*, size_t relnum,
 819                  const elfcpp::Rela<size, false>&, unsigned int r_type,
 820                  typename elfcpp::Elf_types<size>::Elf_Addr value,
 821                  unsigned char* view,
 822                  typename elfcpp::Elf_types<size>::Elf_Addr,
 823                  section_size_type view_size);
 824
 825     // Do a TLS General-Dynamic to Local-Exec transition.
 826     inline void
 827     tls_gd_to_le(const Relocate_info<size, false>*, size_t relnum,
 828                  Output_segment* tls_segment,
 829                  const elfcpp::Rela<size, false>&, unsigned int r_type,
 830                  typename elfcpp::Elf_types<size>::Elf_Addr value,
 831                  unsigned char* view,
 832                  section_size_type view_size);
 833
 834     // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
 835     inline void
 836     tls_desc_gd_to_ie(const Relocate_info<size, false>*, size_t relnum,
 837                       const elfcpp::Rela<size, false>&, unsigned int r_type,
 838                       typename elfcpp::Elf_types<size>::Elf_Addr value,
 839                       unsigned char* view,
 840                       typename elfcpp::Elf_types<size>::Elf_Addr,
 841                       section_size_type view_size);
 842
 843     // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
 844     inline void
 845     tls_desc_gd_to_le(const Relocate_info<size, false>*, size_t relnum,
 846                       Output_segment* tls_segment,
 847                       const elfcpp::Rela<size, false>&, unsigned int r_type,
 848                       typename elfcpp::Elf_types<size>::Elf_Addr value,
 849                       unsigned char* view,
 850                       section_size_type view_size);
 851
 852     // Do a TLS Local-Dynamic to Local-Exec transition.
 853     inline void
 854     tls_ld_to_le(const Relocate_info<size, false>*, size_t relnum,
 855                  Output_segment* tls_segment,
 856                  const elfcpp::Rela<size, false>&, unsigned int r_type,
 857                  typename elfcpp::Elf_types<size>::Elf_Addr value,
 858                  unsigned char* view,
 859                  section_size_type view_size);
 860
 861     // Do a TLS Initial-Exec to Local-Exec transition.
 862     static inline void
 863     tls_ie_to_le(const Relocate_info<size, false>*, size_t relnum,
 864                  Output_segment* tls_segment,
 865                  const elfcpp::Rela<size, false>&, unsigned int r_type,
 866                  typename elfcpp::Elf_types<size>::Elf_Addr value,
 867                  unsigned char* view,
 868                  section_size_type view_size);
 869
 870     // This is set if we should skip the next reloc, which should be a
 871     // PLT32 reloc against ___tls_get_addr.
 872     bool skip_call_tls_get_addr_;
 873   };
 874
 875   // Check if relocation against this symbol is a candidate for
 876   // conversion from
 877   // mov foo@GOTPCREL(%rip), %reg
 878   // to lea foo(%rip), %reg.
 879   static bool
 880   can_convert_mov_to_lea(const Symbol* gsym)
 881   {
 882     gold_assert(gsym != NULL);
 883     return (gsym->type() != elfcpp::STT_GNU_IFUNC
 884             && !gsym->is_undefined ()
 885             && !gsym->is_from_dynobj()
 886             && !gsym->is_preemptible()
 887             && (!parameters->options().shared()
 888                 || (gsym->visibility() != elfcpp::STV_DEFAULT
 889                     && gsym->visibility() != elfcpp::STV_PROTECTED)
 890                 || parameters->options().Bsymbolic())
 891             && strcmp(gsym->name(), "_DYNAMIC") != 0);
 892   }
 893
 894   // Adjust TLS relocation type based on the options and whether this
 895   // is a local symbol.
 896   static tls::Tls_optimization
 897   optimize_tls_reloc(bool is_final, int r_type);
 898
 899   // Get the GOT section, creating it if necessary.
 900   Output_data_got<64, false>*
 901   got_section(Symbol_table*, Layout*);
 902
 903   // Get the GOT PLT section.
 904   Output_data_got_plt_x86_64*
 905   got_plt_section() const
 906   {
 907     gold_assert(this->got_plt_ != NULL);
 908     return this->got_plt_;
 909   }
 910
 911   // Get the GOT section for TLSDESC entries.
 912   Output_data_got<64, false>*
 913   got_tlsdesc_section() const
 914   {
 915     gold_assert(this->got_tlsdesc_ != NULL);
 916     return this->got_tlsdesc_;
 917   }
 918
 919   // Create the PLT section.
 920   void
 921   make_plt_section(Symbol_table* symtab, Layout* layout);
 922
 923   // Create a PLT entry for a global symbol.
 924   void
 925   make_plt_entry(Symbol_table*, Layout*, Symbol*);
 926
 927   // Create a PLT entry for a local STT_GNU_IFUNC symbol.
 928   void
 929   make_local_ifunc_plt_entry(Symbol_table*, Layout*,
 930                              Sized_relobj_file<size, false>* relobj,
 931                              unsigned int local_sym_index);
 932
 933   // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
 934   void
 935   define_tls_base_symbol(Symbol_table*, Layout*);
 936
 937   // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
 938   void
 939   reserve_tlsdesc_entries(Symbol_table* symtab, Layout* layout);
 940
 941   // Create a GOT entry for the TLS module index.
 942   unsigned int
 943   got_mod_index_entry(Symbol_table* symtab, Layout* layout,
 944                       Sized_relobj_file<size, false>* object);
 945
 946   // Get the PLT section.
 947   Output_data_plt_x86_64<size>*
 948   plt_section() const
 949   {
 950     gold_assert(this->plt_ != NULL);
 951     return this->plt_;
 952   }
 953
 954   // Get the dynamic reloc section, creating it if necessary.
 955   Reloc_section*
 956   rela_dyn_section(Layout*);
 957
 958   // Get the section to use for TLSDESC relocations.
 959   Reloc_section*
 960   rela_tlsdesc_section(Layout*) const;
 961
 962   // Get the section to use for IRELATIVE relocations.
 963   Reloc_section*
 964   rela_irelative_section(Layout*);
 965
 966   // Add a potential copy relocation.
 967   void
 968   copy_reloc(Symbol_table* symtab, Layout* layout,
 969              Sized_relobj_file<size, false>* object,
 970              unsigned int shndx, Output_section* output_section,
 971              Symbol* sym, const elfcpp::Rela<size, false>& reloc)
 972   {
 973     unsigned int r_type = elfcpp::elf_r_type<size>(reloc.get_r_info());
 974     this->copy_relocs_.copy_reloc(symtab, layout,
 975                                   symtab->get_sized_symbol<size>(sym),
 976                                   object, shndx, output_section,
 977                                   r_type, reloc.get_r_offset(),
 978                                   reloc.get_r_addend(),
 979                                   this->rela_dyn_section(layout));
 980   }
 981
 982   // Information about this specific target which we pass to the
 983   // general Target structure.
 984   static const Target::Target_info x86_64_info;
 985
 986   // The types of GOT entries needed for this platform.
 987   // These values are exposed to the ABI in an incremental link.
 988   // Do not renumber existing values without changing the version
 989   // number of the .gnu_incremental_inputs section.
 990   enum Got_type
 991   {
 992     GOT_TYPE_STANDARD = 0,      // GOT entry for a regular symbol
 993     GOT_TYPE_TLS_OFFSET = 1,    // GOT entry for TLS offset
 994     GOT_TYPE_TLS_PAIR = 2,      // GOT entry for TLS module/offset pair
 995     GOT_TYPE_TLS_DESC = 3       // GOT entry for TLS_DESC pair
 996   };
 997
 998   // This type is used as the argument to the target specific
 999   // relocation routines.  The only target specific reloc is
1000   // R_X86_64_TLSDESC against a local symbol.
1001   struct Tlsdesc_info
1002   {
1003     Tlsdesc_info(Sized_relobj_file<size, false>* a_object, unsigned int a_r_sym)
1004       : object(a_object), r_sym(a_r_sym)
1005     { }
1006
1007     // The object in which the local symbol is defined.
1008     Sized_relobj_file<size, false>* object;
1009     // The local symbol index in the object.
1010     unsigned int r_sym;
1011   };
1012
1013   // The GOT section.
1014   Output_data_got<64, false>* got_;
1015   // The PLT section.
1016   Output_data_plt_x86_64<size>* plt_;
1017   // The GOT PLT section.
1018   Output_data_got_plt_x86_64* got_plt_;
1019   // The GOT section for IRELATIVE relocations.
1020   Output_data_space* got_irelative_;
1021   // The GOT section for TLSDESC relocations.
1022   Output_data_got<64, false>* got_tlsdesc_;
1023   // The _GLOBAL_OFFSET_TABLE_ symbol.
1024   Symbol* global_offset_table_;
1025   // The dynamic reloc section.
1026   Reloc_section* rela_dyn_;
1027   // The section to use for IRELATIVE relocs.
1028   Reloc_section* rela_irelative_;
1029   // Relocs saved to avoid a COPY reloc.
1030   Copy_relocs<elfcpp::SHT_RELA, size, false> copy_relocs_;
1031   // Offset of the GOT entry for the TLS module index.
1032   unsigned int got_mod_index_offset_;
1033   // We handle R_X86_64_TLSDESC against a local symbol as a target
1034   // specific relocation.  Here we store the object and local symbol
1035   // index for the relocation.
1036   std::vector<Tlsdesc_info> tlsdesc_reloc_info_;
1037   // True if the _TLS_MODULE_BASE_ symbol has been defined.
1038   bool tls_base_symbol_defined_;
1039 };
1040
1041 template<>
1042 const Target::Target_info Target_x86_64<64>::x86_64_info =
1043 {
1044   64,                   // size
1045   false,                // is_big_endian
1046   elfcpp::EM_X86_64,    // machine_code
1047   false,                // has_make_symbol
1048   false,                // has_resolve
1049   true,                 // has_code_fill
1050   true,                 // is_default_stack_executable
1051   true,                 // can_icf_inline_merge_sections
1052   '\0',                 // wrap_char
1053   "/lib/ld64.so.1",     // program interpreter
1054   0x400000,             // default_text_segment_address
1055   0x1000,               // abi_pagesize (overridable by -z max-page-size)
1056   0x1000,               // common_pagesize (overridable by -z common-page-size)
1057   false,                // isolate_execinstr
1058   0,                    // rosegment_gap
1059   elfcpp::SHN_UNDEF,    // small_common_shndx
1060   elfcpp::SHN_X86_64_LCOMMON,   // large_common_shndx
1061   0,                    // small_common_section_flags
1062   elfcpp::SHF_X86_64_LARGE,     // large_common_section_flags
1063   NULL,                 // attributes_section
1064   NULL,                 // attributes_vendor
1065   "_start",             // entry_symbol_name
1066   32,                   // hash_entry_size
1067 };
1068
1069 template<>
1070 const Target::Target_info Target_x86_64<32>::x86_64_info =
1071 {
1072   32,                   // size
1073   false,                // is_big_endian
1074   elfcpp::EM_X86_64,    // machine_code
1075   false,                // has_make_symbol
1076   false,                // has_resolve
1077   true,                 // has_code_fill
1078   true,                 // is_default_stack_executable
1079   true,                 // can_icf_inline_merge_sections
1080   '\0',                 // wrap_char
1081   "/libx32/ldx32.so.1", // program interpreter
1082   0x400000,             // default_text_segment_address
1083   0x1000,               // abi_pagesize (overridable by -z max-page-size)
1084   0x1000,               // common_pagesize (overridable by -z common-page-size)
1085   false,                // isolate_execinstr
1086   0,                    // rosegment_gap
1087   elfcpp::SHN_UNDEF,    // small_common_shndx
1088   elfcpp::SHN_X86_64_LCOMMON,   // large_common_shndx
1089   0,                    // small_common_section_flags
1090   elfcpp::SHF_X86_64_LARGE,     // large_common_section_flags
1091   NULL,                 // attributes_section
1092   NULL,                 // attributes_vendor
1093   "_start",             // entry_symbol_name
1094   32,                   // hash_entry_size
1095 };
1096
1097 // This is called when a new output section is created.  This is where
1098 // we handle the SHF_X86_64_LARGE.
1099
1100 template<int size>
1101 void
1102 Target_x86_64<size>::do_new_output_section(Output_section* os) const
1103 {
1104   if ((os->flags() & elfcpp::SHF_X86_64_LARGE) != 0)
1105     os->set_is_large_section();
1106 }
1107
1108 // Get the GOT section, creating it if necessary.
1109
1110 template<int size>
1111 Output_data_got<64, false>*
1112 Target_x86_64<size>::got_section(Symbol_table* symtab, Layout* layout)
1113 {
1114   if (this->got_ == NULL)
1115     {
1116       gold_assert(symtab != NULL && layout != NULL);
1117
1118       // When using -z now, we can treat .got.plt as a relro section.
1119       // Without -z now, it is modified after program startup by lazy
1120       // PLT relocations.
1121       bool is_got_plt_relro = parameters->options().now();
1122       Output_section_order got_order = (is_got_plt_relro
1123                                         ? ORDER_RELRO
1124                                         : ORDER_RELRO_LAST);
1125       Output_section_order got_plt_order = (is_got_plt_relro
1126                                             ? ORDER_RELRO
1127                                             : ORDER_NON_RELRO_FIRST);
1128
1129       this->got_ = new Output_data_got<64, false>();
1130
1131       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
1132                                       (elfcpp::SHF_ALLOC
1133                                        | elfcpp::SHF_WRITE),
1134                                       this->got_, got_order, true);
1135
1136       this->got_plt_ = new Output_data_got_plt_x86_64(layout);
1137       layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1138                                       (elfcpp::SHF_ALLOC
1139                                        | elfcpp::SHF_WRITE),
1140                                       this->got_plt_, got_plt_order,
1141                                       is_got_plt_relro);
1142
1143       // The first three entries are reserved.
1144       this->got_plt_->set_current_data_size(3 * 8);
1145
1146       if (!is_got_plt_relro)
1147         {
1148           // Those bytes can go into the relro segment.
1149           layout->increase_relro(3 * 8);
1150         }
1151
1152       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
1153       this->global_offset_table_ =
1154         symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
1155                                       Symbol_table::PREDEFINED,
1156                                       this->got_plt_,
1157                                       0, 0, elfcpp::STT_OBJECT,
1158                                       elfcpp::STB_LOCAL,
1159                                       elfcpp::STV_HIDDEN, 0,
1160                                       false, false);
1161
1162       // If there are any IRELATIVE relocations, they get GOT entries
1163       // in .got.plt after the jump slot entries.
1164       this->got_irelative_ = new Output_data_space(8, "** GOT IRELATIVE PLT");
1165       layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1166                                       (elfcpp::SHF_ALLOC
1167                                        | elfcpp::SHF_WRITE),
1168                                       this->got_irelative_,
1169                                       got_plt_order, is_got_plt_relro);
1170
1171       // If there are any TLSDESC relocations, they get GOT entries in
1172       // .got.plt after the jump slot and IRELATIVE entries.
1173       this->got_tlsdesc_ = new Output_data_got<64, false>();
1174       layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1175                                       (elfcpp::SHF_ALLOC
1176                                        | elfcpp::SHF_WRITE),
1177                                       this->got_tlsdesc_,
1178                                       got_plt_order, is_got_plt_relro);
1179     }
1180
1181   return this->got_;
1182 }
1183
1184 // Get the dynamic reloc section, creating it if necessary.
1185
1186 template<int size>
1187 typename Target_x86_64<size>::Reloc_section*
1188 Target_x86_64<size>::rela_dyn_section(Layout* layout)
1189 {
1190   if (this->rela_dyn_ == NULL)
1191     {
1192       gold_assert(layout != NULL);
1193       this->rela_dyn_ = new Reloc_section(parameters->options().combreloc());
1194       layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
1195                                       elfcpp::SHF_ALLOC, this->rela_dyn_,
1196                                       ORDER_DYNAMIC_RELOCS, false);
1197     }
1198   return this->rela_dyn_;
1199 }
1200
1201 // Get the section to use for IRELATIVE relocs, creating it if
1202 // necessary.  These go in .rela.dyn, but only after all other dynamic
1203 // relocations.  They need to follow the other dynamic relocations so
1204 // that they can refer to global variables initialized by those
1205 // relocs.
1206
1207 template<int size>
1208 typename Target_x86_64<size>::Reloc_section*
1209 Target_x86_64<size>::rela_irelative_section(Layout* layout)
1210 {
1211   if (this->rela_irelative_ == NULL)
1212     {
1213       // Make sure we have already created the dynamic reloc section.
1214       this->rela_dyn_section(layout);
1215       this->rela_irelative_ = new Reloc_section(false);
1216       layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
1217                                       elfcpp::SHF_ALLOC, this->rela_irelative_,
1218                                       ORDER_DYNAMIC_RELOCS, false);
1219       gold_assert(this->rela_dyn_->output_section()
1220                   == this->rela_irelative_->output_section());
1221     }
1222   return this->rela_irelative_;
1223 }
1224
1225 // Write the first three reserved words of the .got.plt section.
1226 // The remainder of the section is written while writing the PLT
1227 // in Output_data_plt_i386::do_write.
1228
1229 void
1230 Output_data_got_plt_x86_64::do_write(Output_file* of)
1231 {
1232   // The first entry in the GOT is the address of the .dynamic section
1233   // aka the PT_DYNAMIC segment.  The next two entries are reserved.
1234   // We saved space for them when we created the section in
1235   // Target_x86_64::got_section.
1236   const off_t got_file_offset = this->offset();
1237   gold_assert(this->data_size() >= 24);
1238   unsigned char* const got_view = of->get_output_view(got_file_offset, 24);
1239   Output_section* dynamic = this->layout_->dynamic_section();
1240   uint64_t dynamic_addr = dynamic == NULL ? 0 : dynamic->address();
1241   elfcpp::Swap<64, false>::writeval(got_view, dynamic_addr);
1242   memset(got_view + 8, 0, 16);
1243   of->write_output_view(got_file_offset, 24, got_view);
1244 }
1245
1246 // Initialize the PLT section.
1247
1248 template<int size>
1249 void
1250 Output_data_plt_x86_64<size>::init(Layout* layout)
1251 {
1252   this->rel_ = new Reloc_section(false);
1253   layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
1254                                   elfcpp::SHF_ALLOC, this->rel_,
1255                                   ORDER_DYNAMIC_PLT_RELOCS, false);
1256 }
1257
1258 template<int size>
1259 void
1260 Output_data_plt_x86_64<size>::do_adjust_output_section(Output_section* os)
1261 {
1262   os->set_entsize(this->get_plt_entry_size());
1263 }
1264
1265 // Add an entry to the PLT.
1266
1267 template<int size>
1268 void
1269 Output_data_plt_x86_64<size>::add_entry(Symbol_table* symtab, Layout* layout,
1270                                         Symbol* gsym)
1271 {
1272   gold_assert(!gsym->has_plt_offset());
1273
1274   unsigned int plt_index;
1275   off_t plt_offset;
1276   section_offset_type got_offset;
1277
1278   unsigned int* pcount;
1279   unsigned int offset;
1280   unsigned int reserved;
1281   Output_section_data_build* got;
1282   if (gsym->type() == elfcpp::STT_GNU_IFUNC
1283       && gsym->can_use_relative_reloc(false))
1284     {
1285       pcount = &this->irelative_count_;
1286       offset = 0;
1287       reserved = 0;
1288       got = this->got_irelative_;
1289     }
1290   else
1291     {
1292       pcount = &this->count_;
1293       offset = 1;
1294       reserved = 3;
1295       got = this->got_plt_;
1296     }
1297
1298   if (!this->is_data_size_valid())
1299     {
1300       // Note that when setting the PLT offset for a non-IRELATIVE
1301       // entry we skip the initial reserved PLT entry.
1302       plt_index = *pcount + offset;
1303       plt_offset = plt_index * this->get_plt_entry_size();
1304
1305       ++*pcount;
1306
1307       got_offset = (plt_index - offset + reserved) * 8;
1308       gold_assert(got_offset == got->current_data_size());
1309
1310       // Every PLT entry needs a GOT entry which points back to the PLT
1311       // entry (this will be changed by the dynamic linker, normally
1312       // lazily when the function is called).
1313       got->set_current_data_size(got_offset + 8);
1314     }
1315   else
1316     {
1317       // FIXME: This is probably not correct for IRELATIVE relocs.
1318
1319       // For incremental updates, find an available slot.
1320       plt_offset = this->free_list_.allocate(this->get_plt_entry_size(),
1321                                              this->get_plt_entry_size(), 0);
1322       if (plt_offset == -1)
1323         gold_fallback(_("out of patch space (PLT);"
1324                         " relink with --incremental-full"));
1325
1326       // The GOT and PLT entries have a 1-1 correspondance, so the GOT offset
1327       // can be calculated from the PLT index, adjusting for the three
1328       // reserved entries at the beginning of the GOT.
1329       plt_index = plt_offset / this->get_plt_entry_size() - 1;
1330       got_offset = (plt_index - offset + reserved) * 8;
1331     }
1332
1333   gsym->set_plt_offset(plt_offset);
1334
1335   // Every PLT entry needs a reloc.
1336   this->add_relocation(symtab, layout, gsym, got_offset);
1337
1338   // Note that we don't need to save the symbol.  The contents of the
1339   // PLT are independent of which symbols are used.  The symbols only
1340   // appear in the relocations.
1341 }
1342
1343 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.  Return
1344 // the PLT offset.
1345
1346 template<int size>
1347 unsigned int
1348 Output_data_plt_x86_64<size>::add_local_ifunc_entry(
1349     Symbol_table* symtab,
1350     Layout* layout,
1351     Sized_relobj_file<size, false>* relobj,
1352     unsigned int local_sym_index)
1353 {
1354   unsigned int plt_offset = this->irelative_count_ * this->get_plt_entry_size();
1355   ++this->irelative_count_;
1356
1357   section_offset_type got_offset = this->got_irelative_->current_data_size();
1358
1359   // Every PLT entry needs a GOT entry which points back to the PLT
1360   // entry.
1361   this->got_irelative_->set_current_data_size(got_offset + 8);
1362
1363   // Every PLT entry needs a reloc.
1364   Reloc_section* rela = this->rela_irelative(symtab, layout);
1365   rela->add_symbolless_local_addend(relobj, local_sym_index,
1366                                     elfcpp::R_X86_64_IRELATIVE,
1367                                     this->got_irelative_, got_offset, 0);
1368
1369   return plt_offset;
1370 }
1371
1372 // Add the relocation for a PLT entry.
1373
1374 template<int size>
1375 void
1376 Output_data_plt_x86_64<size>::add_relocation(Symbol_table* symtab,
1377                                              Layout* layout,
1378                                              Symbol* gsym,
1379                                              unsigned int got_offset)
1380 {
1381   if (gsym->type() == elfcpp::STT_GNU_IFUNC
1382       && gsym->can_use_relative_reloc(false))
1383     {
1384       Reloc_section* rela = this->rela_irelative(symtab, layout);
1385       rela->add_symbolless_global_addend(gsym, elfcpp::R_X86_64_IRELATIVE,
1386                                          this->got_irelative_, got_offset, 0);
1387     }
1388   else
1389     {
1390       gsym->set_needs_dynsym_entry();
1391       this->rel_->add_global(gsym, elfcpp::R_X86_64_JUMP_SLOT, this->got_plt_,
1392                              got_offset, 0);
1393     }
1394 }
1395
1396 // Return where the TLSDESC relocations should go, creating it if
1397 // necessary.  These follow the JUMP_SLOT relocations.
1398
1399 template<int size>
1400 typename Output_data_plt_x86_64<size>::Reloc_section*
1401 Output_data_plt_x86_64<size>::rela_tlsdesc(Layout* layout)
1402 {
1403   if (this->tlsdesc_rel_ == NULL)
1404     {
1405       this->tlsdesc_rel_ = new Reloc_section(false);
1406       layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
1407                                       elfcpp::SHF_ALLOC, this->tlsdesc_rel_,
1408                                       ORDER_DYNAMIC_PLT_RELOCS, false);
1409       gold_assert(this->tlsdesc_rel_->output_section()
1410                   == this->rel_->output_section());
1411     }
1412   return this->tlsdesc_rel_;
1413 }
1414
1415 // Return where the IRELATIVE relocations should go in the PLT.  These
1416 // follow the JUMP_SLOT and the TLSDESC relocations.
1417
1418 template<int size>
1419 typename Output_data_plt_x86_64<size>::Reloc_section*
1420 Output_data_plt_x86_64<size>::rela_irelative(Symbol_table* symtab,
1421                                              Layout* layout)
1422 {
1423   if (this->irelative_rel_ == NULL)
1424     {
1425       // Make sure we have a place for the TLSDESC relocations, in
1426       // case we see any later on.
1427       this->rela_tlsdesc(layout);
1428       this->irelative_rel_ = new Reloc_section(false);
1429       layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
1430                                       elfcpp::SHF_ALLOC, this->irelative_rel_,
1431                                       ORDER_DYNAMIC_PLT_RELOCS, false);
1432       gold_assert(this->irelative_rel_->output_section()
1433                   == this->rel_->output_section());
1434
1435       if (parameters->doing_static_link())
1436         {
1437           // A statically linked executable will only have a .rela.plt
1438           // section to hold R_X86_64_IRELATIVE relocs for
1439           // STT_GNU_IFUNC symbols.  The library will use these
1440           // symbols to locate the IRELATIVE relocs at program startup
1441           // time.
1442           symtab->define_in_output_data("__rela_iplt_start", NULL,
1443                                         Symbol_table::PREDEFINED,
1444                                         this->irelative_rel_, 0, 0,
1445                                         elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1446                                         elfcpp::STV_HIDDEN, 0, false, true);
1447           symtab->define_in_output_data("__rela_iplt_end", NULL,
1448                                         Symbol_table::PREDEFINED,
1449                                         this->irelative_rel_, 0, 0,
1450                                         elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1451                                         elfcpp::STV_HIDDEN, 0, true, true);
1452         }
1453     }
1454   return this->irelative_rel_;
1455 }
1456
1457 // Return the PLT address to use for a global symbol.
1458
1459 template<int size>
1460 uint64_t
1461 Output_data_plt_x86_64<size>::address_for_global(const Symbol* gsym)
1462 {
1463   uint64_t offset = 0;
1464   if (gsym->type() == elfcpp::STT_GNU_IFUNC
1465       && gsym->can_use_relative_reloc(false))
1466     offset = (this->count_ + 1) * this->get_plt_entry_size();
1467   return this->address() + offset + gsym->plt_offset();
1468 }
1469
1470 // Return the PLT address to use for a local symbol.  These are always
1471 // IRELATIVE relocs.
1472
1473 template<int size>
1474 uint64_t
1475 Output_data_plt_x86_64<size>::address_for_local(const Relobj* object,
1476                                                 unsigned int r_sym)
1477 {
1478   return (this->address()
1479           + (this->count_ + 1) * this->get_plt_entry_size()
1480           + object->local_plt_offset(r_sym));
1481 }
1482
1483 // Set the final size.
1484 template<int size>
1485 void
1486 Output_data_plt_x86_64<size>::set_final_data_size()
1487 {
1488   unsigned int count = this->count_ + this->irelative_count_;
1489   if (this->has_tlsdesc_entry())
1490     ++count;
1491   this->set_data_size((count + 1) * this->get_plt_entry_size());
1492 }
1493
1494 // The first entry in the PLT for an executable.
1495
1496 template<int size>
1497 const unsigned char
1498 Output_data_plt_x86_64_standard<size>::first_plt_entry[plt_entry_size] =
1499 {
1500   // From AMD64 ABI Draft 0.98, page 76
1501   0xff, 0x35,   // pushq contents of memory address
1502   0, 0, 0, 0,   // replaced with address of .got + 8
1503   0xff, 0x25,   // jmp indirect
1504   0, 0, 0, 0,   // replaced with address of .got + 16
1505   0x90, 0x90, 0x90, 0x90   // noop (x4)
1506 };
1507
1508 template<int size>
1509 void
1510 Output_data_plt_x86_64_standard<size>::do_fill_first_plt_entry(
1511     unsigned char* pov,
1512     typename elfcpp::Elf_types<size>::Elf_Addr got_address,
1513     typename elfcpp::Elf_types<size>::Elf_Addr plt_address)
1514 {
1515   memcpy(pov, first_plt_entry, plt_entry_size);
1516   // We do a jmp relative to the PC at the end of this instruction.
1517   elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1518                                               (got_address + 8
1519                                                - (plt_address + 6)));
1520   elfcpp::Swap<32, false>::writeval(pov + 8,
1521                                     (got_address + 16
1522                                      - (plt_address + 12)));
1523 }
1524
1525 // Subsequent entries in the PLT for an executable.
1526
1527 template<int size>
1528 const unsigned char
1529 Output_data_plt_x86_64_standard<size>::plt_entry[plt_entry_size] =
1530 {
1531   // From AMD64 ABI Draft 0.98, page 76
1532   0xff, 0x25,   // jmpq indirect
1533   0, 0, 0, 0,   // replaced with address of symbol in .got
1534   0x68,         // pushq immediate
1535   0, 0, 0, 0,   // replaced with offset into relocation table
1536   0xe9,         // jmpq relative
1537   0, 0, 0, 0    // replaced with offset to start of .plt
1538 };
1539
1540 template<int size>
1541 unsigned int
1542 Output_data_plt_x86_64_standard<size>::do_fill_plt_entry(
1543     unsigned char* pov,
1544     typename elfcpp::Elf_types<size>::Elf_Addr got_address,
1545     typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
1546     unsigned int got_offset,
1547     unsigned int plt_offset,
1548     unsigned int plt_index)
1549 {
1550   // Check PC-relative offset overflow in PLT entry.
1551   uint64_t plt_got_pcrel_offset = (got_address + got_offset
1552                                    - (plt_address + plt_offset + 6));
1553   if (Bits<32>::has_overflow(plt_got_pcrel_offset))
1554     gold_error(_("PC-relative offset overflow in PLT entry %d"),
1555                plt_index + 1);
1556
1557   memcpy(pov, plt_entry, plt_entry_size);
1558   elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1559                                               plt_got_pcrel_offset);
1560
1561   elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_index);
1562   elfcpp::Swap<32, false>::writeval(pov + 12,
1563                                     - (plt_offset + plt_entry_size));
1564
1565   return 6;
1566 }
1567
1568 // The reserved TLSDESC entry in the PLT for an executable.
1569
1570 template<int size>
1571 const unsigned char
1572 Output_data_plt_x86_64_standard<size>::tlsdesc_plt_entry[plt_entry_size] =
1573 {
1574   // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
1575   // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
1576   0xff, 0x35,   // pushq x(%rip)
1577   0, 0, 0, 0,   // replaced with address of linkmap GOT entry (at PLTGOT + 8)
1578   0xff, 0x25,   // jmpq *y(%rip)
1579   0, 0, 0, 0,   // replaced with offset of reserved TLSDESC_GOT entry
1580   0x0f, 0x1f,   // nop
1581   0x40, 0
1582 };
1583
1584 template<int size>
1585 void
1586 Output_data_plt_x86_64_standard<size>::do_fill_tlsdesc_entry(
1587     unsigned char* pov,
1588     typename elfcpp::Elf_types<size>::Elf_Addr got_address,
1589     typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
1590     typename elfcpp::Elf_types<size>::Elf_Addr got_base,
1591     unsigned int tlsdesc_got_offset,
1592     unsigned int plt_offset)
1593 {
1594   memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
1595   elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1596                                               (got_address + 8
1597                                                - (plt_address + plt_offset
1598                                                   + 6)));
1599   elfcpp::Swap_unaligned<32, false>::writeval(pov + 8,
1600                                               (got_base
1601                                                + tlsdesc_got_offset
1602                                                - (plt_address + plt_offset
1603                                                   + 12)));
1604 }
1605
1606 // The .eh_frame unwind information for the PLT.
1607
1608 template<int size>
1609 const unsigned char
1610 Output_data_plt_x86_64<size>::plt_eh_frame_cie[plt_eh_frame_cie_size] =
1611 {
1612   1,                            // CIE version.
1613   'z',                          // Augmentation: augmentation size included.
1614   'R',                          // Augmentation: FDE encoding included.
1615   '\0',                         // End of augmentation string.
1616   1,                            // Code alignment factor.
1617   0x78,                         // Data alignment factor.
1618   16,                           // Return address column.
1619   1,                            // Augmentation size.
1620   (elfcpp::DW_EH_PE_pcrel       // FDE encoding.
1621    | elfcpp::DW_EH_PE_sdata4),
1622   elfcpp::DW_CFA_def_cfa, 7, 8, // DW_CFA_def_cfa: r7 (rsp) ofs 8.
1623   elfcpp::DW_CFA_offset + 16, 1,// DW_CFA_offset: r16 (rip) at cfa-8.
1624   elfcpp::DW_CFA_nop,           // Align to 16 bytes.
1625   elfcpp::DW_CFA_nop
1626 };
1627
1628 template<int size>
1629 const unsigned char
1630 Output_data_plt_x86_64_standard<size>::plt_eh_frame_fde[plt_eh_frame_fde_size] =
1631 {
1632   0, 0, 0, 0,                           // Replaced with offset to .plt.
1633   0, 0, 0, 0,                           // Replaced with size of .plt.
1634   0,                                    // Augmentation size.
1635   elfcpp::DW_CFA_def_cfa_offset, 16,    // DW_CFA_def_cfa_offset: 16.
1636   elfcpp::DW_CFA_advance_loc + 6,       // Advance 6 to __PLT__ + 6.
1637   elfcpp::DW_CFA_def_cfa_offset, 24,    // DW_CFA_def_cfa_offset: 24.
1638   elfcpp::DW_CFA_advance_loc + 10,      // Advance 10 to __PLT__ + 16.
1639   elfcpp::DW_CFA_def_cfa_expression,    // DW_CFA_def_cfa_expression.
1640   11,                                   // Block length.
1641   elfcpp::DW_OP_breg7, 8,               // Push %rsp + 8.
1642   elfcpp::DW_OP_breg16, 0,              // Push %rip.
1643   elfcpp::DW_OP_lit15,                  // Push 0xf.
1644   elfcpp::DW_OP_and,                    // & (%rip & 0xf).
1645   elfcpp::DW_OP_lit11,                  // Push 0xb.
1646   elfcpp::DW_OP_ge,                     // >= ((%rip & 0xf) >= 0xb)
1647   elfcpp::DW_OP_lit3,                   // Push 3.
1648   elfcpp::DW_OP_shl,                    // << (((%rip & 0xf) >= 0xb) << 3)
1649   elfcpp::DW_OP_plus,                   // + ((((%rip&0xf)>=0xb)<<3)+%rsp+8
1650   elfcpp::DW_CFA_nop,                   // Align to 32 bytes.
1651   elfcpp::DW_CFA_nop,
1652   elfcpp::DW_CFA_nop,
1653   elfcpp::DW_CFA_nop
1654 };
1655
1656 // Write out the PLT.  This uses the hand-coded instructions above,
1657 // and adjusts them as needed.  This is specified by the AMD64 ABI.
1658
1659 template<int size>
1660 void
1661 Output_data_plt_x86_64<size>::do_write(Output_file* of)
1662 {
1663   const off_t offset = this->offset();
1664   const section_size_type oview_size =
1665     convert_to_section_size_type(this->data_size());
1666   unsigned char* const oview = of->get_output_view(offset, oview_size);
1667
1668   const off_t got_file_offset = this->got_plt_->offset();
1669   gold_assert(parameters->incremental_update()
1670               || (got_file_offset + this->got_plt_->data_size()
1671                   == this->got_irelative_->offset()));
1672   const section_size_type got_size =
1673     convert_to_section_size_type(this->got_plt_->data_size()
1674                                  + this->got_irelative_->data_size());
1675   unsigned char* const got_view = of->get_output_view(got_file_offset,
1676                                                       got_size);
1677
1678   unsigned char* pov = oview;
1679
1680   // The base address of the .plt section.
1681   typename elfcpp::Elf_types<size>::Elf_Addr plt_address = this->address();
1682   // The base address of the .got section.
1683   typename elfcpp::Elf_types<size>::Elf_Addr got_base = this->got_->address();
1684   // The base address of the PLT portion of the .got section,
1685   // which is where the GOT pointer will point, and where the
1686   // three reserved GOT entries are located.
1687   typename elfcpp::Elf_types<size>::Elf_Addr got_address
1688     = this->got_plt_->address();
1689
1690   this->fill_first_plt_entry(pov, got_address, plt_address);
1691   pov += this->get_plt_entry_size();
1692
1693   // The first three entries in the GOT are reserved, and are written
1694   // by Output_data_got_plt_x86_64::do_write.
1695   unsigned char* got_pov = got_view + 24;
1696
1697   unsigned int plt_offset = this->get_plt_entry_size();
1698   unsigned int got_offset = 24;
1699   const unsigned int count = this->count_ + this->irelative_count_;
1700   for (unsigned int plt_index = 0;
1701        plt_index < count;
1702        ++plt_index,
1703          pov += this->get_plt_entry_size(),
1704          got_pov += 8,
1705          plt_offset += this->get_plt_entry_size(),
1706          got_offset += 8)
1707     {
1708       // Set and adjust the PLT entry itself.
1709       unsigned int lazy_offset = this->fill_plt_entry(pov,
1710                                                       got_address, plt_address,
1711                                                       got_offset, plt_offset,
1712                                                       plt_index);
1713
1714       // Set the entry in the GOT.
1715       elfcpp::Swap<64, false>::writeval(got_pov,
1716                                         plt_address + plt_offset + lazy_offset);
1717     }
1718
1719   if (this->has_tlsdesc_entry())
1720     {
1721       // Set and adjust the reserved TLSDESC PLT entry.
1722       unsigned int tlsdesc_got_offset = this->get_tlsdesc_got_offset();
1723       this->fill_tlsdesc_entry(pov, got_address, plt_address, got_base,
1724                                tlsdesc_got_offset, plt_offset);
1725       pov += this->get_plt_entry_size();
1726     }
1727
1728   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
1729   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
1730
1731   of->write_output_view(offset, oview_size, oview);
1732   of->write_output_view(got_file_offset, got_size, got_view);
1733 }
1734
1735 // Create the PLT section.
1736
1737 template<int size>
1738 void
1739 Target_x86_64<size>::make_plt_section(Symbol_table* symtab, Layout* layout)
1740 {
1741   if (this->plt_ == NULL)
1742     {
1743       // Create the GOT sections first.
1744       this->got_section(symtab, layout);
1745
1746       this->plt_ = this->make_data_plt(layout, this->got_, this->got_plt_,
1747                                        this->got_irelative_);
1748
1749       // Add unwind information if requested.
1750       if (parameters->options().ld_generated_unwind_info())
1751         this->plt_->add_eh_frame(layout);
1752
1753       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
1754                                       (elfcpp::SHF_ALLOC
1755                                        | elfcpp::SHF_EXECINSTR),
1756                                       this->plt_, ORDER_PLT, false);
1757
1758       // Make the sh_info field of .rela.plt point to .plt.
1759       Output_section* rela_plt_os = this->plt_->rela_plt()->output_section();
1760       rela_plt_os->set_info_section(this->plt_->output_section());
1761     }
1762 }
1763
1764 // Return the section for TLSDESC relocations.
1765
1766 template<int size>
1767 typename Target_x86_64<size>::Reloc_section*
1768 Target_x86_64<size>::rela_tlsdesc_section(Layout* layout) const
1769 {
1770   return this->plt_section()->rela_tlsdesc(layout);
1771 }
1772
1773 // Create a PLT entry for a global symbol.
1774
1775 template<int size>
1776 void
1777 Target_x86_64<size>::make_plt_entry(Symbol_table* symtab, Layout* layout,
1778                                     Symbol* gsym)
1779 {
1780   if (gsym->has_plt_offset())
1781     return;
1782
1783   if (this->plt_ == NULL)
1784     this->make_plt_section(symtab, layout);
1785
1786   this->plt_->add_entry(symtab, layout, gsym);
1787 }
1788
1789 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1790
1791 template<int size>
1792 void
1793 Target_x86_64<size>::make_local_ifunc_plt_entry(
1794     Symbol_table* symtab, Layout* layout,
1795     Sized_relobj_file<size, false>* relobj,
1796     unsigned int local_sym_index)
1797 {
1798   if (relobj->local_has_plt_offset(local_sym_index))
1799     return;
1800   if (this->plt_ == NULL)
1801     this->make_plt_section(symtab, layout);
1802   unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout,
1803                                                               relobj,
1804                                                               local_sym_index);
1805   relobj->set_local_plt_offset(local_sym_index, plt_offset);
1806 }
1807
1808 // Return the number of entries in the PLT.
1809
1810 template<int size>
1811 unsigned int
1812 Target_x86_64<size>::plt_entry_count() const
1813 {
1814   if (this->plt_ == NULL)
1815     return 0;
1816   return this->plt_->entry_count();
1817 }
1818
1819 // Return the offset of the first non-reserved PLT entry.
1820
1821 template<int size>
1822 unsigned int
1823 Target_x86_64<size>::first_plt_entry_offset() const
1824 {
1825   return this->plt_->first_plt_entry_offset();
1826 }
1827
1828 // Return the size of each PLT entry.
1829
1830 template<int size>
1831 unsigned int
1832 Target_x86_64<size>::plt_entry_size() const
1833 {
1834   return this->plt_->get_plt_entry_size();
1835 }
1836
1837 // Create the GOT and PLT sections for an incremental update.
1838
1839 template<int size>
1840 Output_data_got_base*
1841 Target_x86_64<size>::init_got_plt_for_update(Symbol_table* symtab,
1842                                        Layout* layout,
1843                                        unsigned int got_count,
1844                                        unsigned int plt_count)
1845 {
1846   gold_assert(this->got_ == NULL);
1847
1848   this->got_ = new Output_data_got<64, false>(got_count * 8);
1849   layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
1850                                   (elfcpp::SHF_ALLOC
1851                                    | elfcpp::SHF_WRITE),
1852                                   this->got_, ORDER_RELRO_LAST,
1853                                   true);
1854
1855   // Add the three reserved entries.
1856   this->got_plt_ = new Output_data_got_plt_x86_64(layout, (plt_count + 3) * 8);
1857   layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1858                                   (elfcpp::SHF_ALLOC
1859                                    | elfcpp::SHF_WRITE),
1860                                   this->got_plt_, ORDER_NON_RELRO_FIRST,
1861                                   false);
1862
1863   // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
1864   this->global_offset_table_ =
1865     symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
1866                                   Symbol_table::PREDEFINED,
1867                                   this->got_plt_,
1868                                   0, 0, elfcpp::STT_OBJECT,
1869                                   elfcpp::STB_LOCAL,
1870                                   elfcpp::STV_HIDDEN, 0,
1871                                   false, false);
1872
1873   // If there are any TLSDESC relocations, they get GOT entries in
1874   // .got.plt after the jump slot entries.
1875   // FIXME: Get the count for TLSDESC entries.
1876   this->got_tlsdesc_ = new Output_data_got<64, false>(0);
1877   layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1878                                   elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
1879                                   this->got_tlsdesc_,
1880                                   ORDER_NON_RELRO_FIRST, false);
1881
1882   // If there are any IRELATIVE relocations, they get GOT entries in
1883   // .got.plt after the jump slot and TLSDESC entries.
1884   this->got_irelative_ = new Output_data_space(0, 8, "** GOT IRELATIVE PLT");
1885   layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1886                                   elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
1887                                   this->got_irelative_,
1888                                   ORDER_NON_RELRO_FIRST, false);
1889
1890   // Create the PLT section.
1891   this->plt_ = this->make_data_plt(layout, this->got_,
1892                                    this->got_plt_,
1893                                    this->got_irelative_,
1894                                    plt_count);
1895
1896   // Add unwind information if requested.
1897   if (parameters->options().ld_generated_unwind_info())
1898     this->plt_->add_eh_frame(layout);
1899
1900   layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
1901                                   elfcpp::SHF_ALLOC | elfcpp::SHF_EXECINSTR,
1902                                   this->plt_, ORDER_PLT, false);
1903
1904   // Make the sh_info field of .rela.plt point to .plt.
1905   Output_section* rela_plt_os = this->plt_->rela_plt()->output_section();
1906   rela_plt_os->set_info_section(this->plt_->output_section());
1907
1908   // Create the rela_dyn section.
1909   this->rela_dyn_section(layout);
1910
1911   return this->got_;
1912 }
1913
1914 // Reserve a GOT entry for a local symbol, and regenerate any
1915 // necessary dynamic relocations.
1916
1917 template<int size>
1918 void
1919 Target_x86_64<size>::reserve_local_got_entry(
1920     unsigned int got_index,
1921     Sized_relobj<size, false>* obj,
1922     unsigned int r_sym,
1923     unsigned int got_type)
1924 {
1925   unsigned int got_offset = got_index * 8;
1926   Reloc_section* rela_dyn = this->rela_dyn_section(NULL);
1927
1928   this->got_->reserve_local(got_index, obj, r_sym, got_type);
1929   switch (got_type)
1930     {
1931     case GOT_TYPE_STANDARD:
1932       if (parameters->options().output_is_position_independent())
1933         rela_dyn->add_local_relative(obj, r_sym, elfcpp::R_X86_64_RELATIVE,
1934                                      this->got_, got_offset, 0, false);
1935       break;
1936     case GOT_TYPE_TLS_OFFSET:
1937       rela_dyn->add_local(obj, r_sym, elfcpp::R_X86_64_TPOFF64,
1938                           this->got_, got_offset, 0);
1939       break;
1940     case GOT_TYPE_TLS_PAIR:
1941       this->got_->reserve_slot(got_index + 1);
1942       rela_dyn->add_local(obj, r_sym, elfcpp::R_X86_64_DTPMOD64,
1943                           this->got_, got_offset, 0);
1944       break;
1945     case GOT_TYPE_TLS_DESC:
1946       gold_fatal(_("TLS_DESC not yet supported for incremental linking"));
1947       // this->got_->reserve_slot(got_index + 1);
1948       // rela_dyn->add_target_specific(elfcpp::R_X86_64_TLSDESC, arg,
1949       //                               this->got_, got_offset, 0);
1950       break;
1951     default:
1952       gold_unreachable();
1953     }
1954 }
1955
1956 // Reserve a GOT entry for a global symbol, and regenerate any
1957 // necessary dynamic relocations.
1958
1959 template<int size>
1960 void
1961 Target_x86_64<size>::reserve_global_got_entry(unsigned int got_index,
1962                                               Symbol* gsym,
1963                                               unsigned int got_type)
1964 {
1965   unsigned int got_offset = got_index * 8;
1966   Reloc_section* rela_dyn = this->rela_dyn_section(NULL);
1967
1968   this->got_->reserve_global(got_index, gsym, got_type);
1969   switch (got_type)
1970     {
1971     case GOT_TYPE_STANDARD:
1972       if (!gsym->final_value_is_known())
1973         {
1974           if (gsym->is_from_dynobj()
1975               || gsym->is_undefined()
1976               || gsym->is_preemptible()
1977               || gsym->type() == elfcpp::STT_GNU_IFUNC)
1978             rela_dyn->add_global(gsym, elfcpp::R_X86_64_GLOB_DAT,
1979                                  this->got_, got_offset, 0);
1980           else
1981             rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_RELATIVE,
1982                                           this->got_, got_offset, 0, false);
1983         }
1984       break;
1985     case GOT_TYPE_TLS_OFFSET:
1986       rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_TPOFF64,
1987                                     this->got_, got_offset, 0, false);
1988       break;
1989     case GOT_TYPE_TLS_PAIR:
1990       this->got_->reserve_slot(got_index + 1);
1991       rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_DTPMOD64,
1992                                     this->got_, got_offset, 0, false);
1993       rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_DTPOFF64,
1994                                     this->got_, got_offset + 8, 0, false);
1995       break;
1996     case GOT_TYPE_TLS_DESC:
1997       this->got_->reserve_slot(got_index + 1);
1998       rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_TLSDESC,
1999                                     this->got_, got_offset, 0, false);
2000       break;
2001     default:
2002       gold_unreachable();
2003     }
2004 }
2005
2006 // Register an existing PLT entry for a global symbol.
2007
2008 template<int size>
2009 void
2010 Target_x86_64<size>::register_global_plt_entry(Symbol_table* symtab,
2011                                                Layout* layout,
2012                                                unsigned int plt_index,
2013                                                Symbol* gsym)
2014 {
2015   gold_assert(this->plt_ != NULL);
2016   gold_assert(!gsym->has_plt_offset());
2017
2018   this->plt_->reserve_slot(plt_index);
2019
2020   gsym->set_plt_offset((plt_index + 1) * this->plt_entry_size());
2021
2022   unsigned int got_offset = (plt_index + 3) * 8;
2023   this->plt_->add_relocation(symtab, layout, gsym, got_offset);
2024 }
2025
2026 // Force a COPY relocation for a given symbol.
2027
2028 template<int size>
2029 void
2030 Target_x86_64<size>::emit_copy_reloc(
2031     Symbol_table* symtab, Symbol* sym, Output_section* os, off_t offset)
2032 {
2033   this->copy_relocs_.emit_copy_reloc(symtab,
2034                                      symtab->get_sized_symbol<size>(sym),
2035                                      os,
2036                                      offset,
2037                                      this->rela_dyn_section(NULL));
2038 }
2039
2040 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
2041
2042 template<int size>
2043 void
2044 Target_x86_64<size>::define_tls_base_symbol(Symbol_table* symtab,
2045                                             Layout* layout)
2046 {
2047   if (this->tls_base_symbol_defined_)
2048     return;
2049
2050   Output_segment* tls_segment = layout->tls_segment();
2051   if (tls_segment != NULL)
2052     {
2053       bool is_exec = parameters->options().output_is_executable();
2054       symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
2055                                        Symbol_table::PREDEFINED,
2056                                        tls_segment, 0, 0,
2057                                        elfcpp::STT_TLS,
2058                                        elfcpp::STB_LOCAL,
2059                                        elfcpp::STV_HIDDEN, 0,
2060                                        (is_exec
2061                                         ? Symbol::SEGMENT_END
2062                                         : Symbol::SEGMENT_START),
2063                                        true);
2064     }
2065   this->tls_base_symbol_defined_ = true;
2066 }
2067
2068 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
2069
2070 template<int size>
2071 void
2072 Target_x86_64<size>::reserve_tlsdesc_entries(Symbol_table* symtab,
2073                                              Layout* layout)
2074 {
2075   if (this->plt_ == NULL)
2076     this->make_plt_section(symtab, layout);
2077
2078   if (!this->plt_->has_tlsdesc_entry())
2079     {
2080       // Allocate the TLSDESC_GOT entry.
2081       Output_data_got<64, false>* got = this->got_section(symtab, layout);
2082       unsigned int got_offset = got->add_constant(0);
2083
2084       // Allocate the TLSDESC_PLT entry.
2085       this->plt_->reserve_tlsdesc_entry(got_offset);
2086     }
2087 }
2088
2089 // Create a GOT entry for the TLS module index.
2090
2091 template<int size>
2092 unsigned int
2093 Target_x86_64<size>::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
2094                                          Sized_relobj_file<size, false>* object)
2095 {
2096   if (this->got_mod_index_offset_ == -1U)
2097     {
2098       gold_assert(symtab != NULL && layout != NULL && object != NULL);
2099       Reloc_section* rela_dyn = this->rela_dyn_section(layout);
2100       Output_data_got<64, false>* got = this->got_section(symtab, layout);
2101       unsigned int got_offset = got->add_constant(0);
2102       rela_dyn->add_local(object, 0, elfcpp::R_X86_64_DTPMOD64, got,
2103                           got_offset, 0);
2104       got->add_constant(0);
2105       this->got_mod_index_offset_ = got_offset;
2106     }
2107   return this->got_mod_index_offset_;
2108 }
2109
2110 // Optimize the TLS relocation type based on what we know about the
2111 // symbol.  IS_FINAL is true if the final address of this symbol is
2112 // known at link time.
2113
2114 template<int size>
2115 tls::Tls_optimization
2116 Target_x86_64<size>::optimize_tls_reloc(bool is_final, int r_type)
2117 {
2118   // If we are generating a shared library, then we can't do anything
2119   // in the linker.
2120   if (parameters->options().shared())
2121     return tls::TLSOPT_NONE;
2122
2123   switch (r_type)
2124     {
2125     case elfcpp::R_X86_64_TLSGD:
2126     case elfcpp::R_X86_64_GOTPC32_TLSDESC:
2127     case elfcpp::R_X86_64_TLSDESC_CALL:
2128       // These are General-Dynamic which permits fully general TLS
2129       // access.  Since we know that we are generating an executable,
2130       // we can convert this to Initial-Exec.  If we also know that
2131       // this is a local symbol, we can further switch to Local-Exec.
2132       if (is_final)
2133         return tls::TLSOPT_TO_LE;
2134       return tls::TLSOPT_TO_IE;
2135
2136     case elfcpp::R_X86_64_TLSLD:
2137       // This is Local-Dynamic, which refers to a local symbol in the
2138       // dynamic TLS block.  Since we know that we generating an
2139       // executable, we can switch to Local-Exec.
2140       return tls::TLSOPT_TO_LE;
2141
2142     case elfcpp::R_X86_64_DTPOFF32:
2143     case elfcpp::R_X86_64_DTPOFF64:
2144       // Another Local-Dynamic reloc.
2145       return tls::TLSOPT_TO_LE;
2146
2147     case elfcpp::R_X86_64_GOTTPOFF:
2148       // These are Initial-Exec relocs which get the thread offset
2149       // from the GOT.  If we know that we are linking against the
2150       // local symbol, we can switch to Local-Exec, which links the
2151       // thread offset into the instruction.
2152       if (is_final)
2153         return tls::TLSOPT_TO_LE;
2154       return tls::TLSOPT_NONE;
2155
2156     case elfcpp::R_X86_64_TPOFF32:
2157       // When we already have Local-Exec, there is nothing further we
2158       // can do.
2159       return tls::TLSOPT_NONE;
2160
2161     default:
2162       gold_unreachable();
2163     }
2164 }
2165
2166 // Get the Reference_flags for a particular relocation.
2167
2168 template<int size>
2169 int
2170 Target_x86_64<size>::Scan::get_reference_flags(unsigned int r_type)
2171 {
2172   switch (r_type)
2173     {
2174     case elfcpp::R_X86_64_NONE:
2175     case elfcpp::R_X86_64_GNU_VTINHERIT:
2176     case elfcpp::R_X86_64_GNU_VTENTRY:
2177     case elfcpp::R_X86_64_GOTPC32:
2178     case elfcpp::R_X86_64_GOTPC64:
2179       // No symbol reference.
2180       return 0;
2181
2182     case elfcpp::R_X86_64_64:
2183     case elfcpp::R_X86_64_32:
2184     case elfcpp::R_X86_64_32S:
2185     case elfcpp::R_X86_64_16:
2186     case elfcpp::R_X86_64_8:
2187       return Symbol::ABSOLUTE_REF;
2188
2189     case elfcpp::R_X86_64_PC64:
2190     case elfcpp::R_X86_64_PC32:
2191     case elfcpp::R_X86_64_PC32_BND:
2192     case elfcpp::R_X86_64_PC16:
2193     case elfcpp::R_X86_64_PC8:
2194     case elfcpp::R_X86_64_GOTOFF64:
2195       return Symbol::RELATIVE_REF;
2196
2197     case elfcpp::R_X86_64_PLT32:
2198     case elfcpp::R_X86_64_PLT32_BND:
2199     case elfcpp::R_X86_64_PLTOFF64:
2200       return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
2201
2202     case elfcpp::R_X86_64_GOT64:
2203     case elfcpp::R_X86_64_GOT32:
2204     case elfcpp::R_X86_64_GOTPCREL64:
2205     case elfcpp::R_X86_64_GOTPCREL:
2206     case elfcpp::R_X86_64_GOTPCRELX:
2207     case elfcpp::R_X86_64_REX_GOTPCRELX:
2208     case elfcpp::R_X86_64_GOTPLT64:
2209       // Absolute in GOT.
2210       return Symbol::ABSOLUTE_REF;
2211
2212     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
2213     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
2214     case elfcpp::R_X86_64_TLSDESC_CALL:
2215     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
2216     case elfcpp::R_X86_64_DTPOFF32:
2217     case elfcpp::R_X86_64_DTPOFF64:
2218     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
2219     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
2220       return Symbol::TLS_REF;
2221
2222     case elfcpp::R_X86_64_COPY:
2223     case elfcpp::R_X86_64_GLOB_DAT:
2224     case elfcpp::R_X86_64_JUMP_SLOT:
2225     case elfcpp::R_X86_64_RELATIVE:
2226     case elfcpp::R_X86_64_IRELATIVE:
2227     case elfcpp::R_X86_64_TPOFF64:
2228     case elfcpp::R_X86_64_DTPMOD64:
2229     case elfcpp::R_X86_64_TLSDESC:
2230     case elfcpp::R_X86_64_SIZE32:
2231     case elfcpp::R_X86_64_SIZE64:
2232     default:
2233       // Not expected.  We will give an error later.
2234       return 0;
2235     }
2236 }
2237
2238 // Report an unsupported relocation against a local symbol.
2239
2240 template<int size>
2241 void
2242 Target_x86_64<size>::Scan::unsupported_reloc_local(
2243      Sized_relobj_file<size, false>* object,
2244      unsigned int r_type)
2245 {
2246   gold_error(_("%s: unsupported reloc %u against local symbol"),
2247              object->name().c_str(), r_type);
2248 }
2249
2250 // We are about to emit a dynamic relocation of type R_TYPE.  If the
2251 // dynamic linker does not support it, issue an error.  The GNU linker
2252 // only issues a non-PIC error for an allocated read-only section.
2253 // Here we know the section is allocated, but we don't know that it is
2254 // read-only.  But we check for all the relocation types which the
2255 // glibc dynamic linker supports, so it seems appropriate to issue an
2256 // error even if the section is not read-only.  If GSYM is not NULL,
2257 // it is the symbol the relocation is against; if it is NULL, the
2258 // relocation is against a local symbol.
2259
2260 template<int size>
2261 void
2262 Target_x86_64<size>::Scan::check_non_pic(Relobj* object, unsigned int r_type,
2263                                          Symbol* gsym)
2264 {
2265   switch (r_type)
2266     {
2267       // These are the relocation types supported by glibc for x86_64
2268       // which should always work.
2269     case elfcpp::R_X86_64_RELATIVE:
2270     case elfcpp::R_X86_64_IRELATIVE:
2271     case elfcpp::R_X86_64_GLOB_DAT:
2272     case elfcpp::R_X86_64_JUMP_SLOT:
2273     case elfcpp::R_X86_64_DTPMOD64:
2274     case elfcpp::R_X86_64_DTPOFF64:
2275     case elfcpp::R_X86_64_TPOFF64:
2276     case elfcpp::R_X86_64_64:
2277     case elfcpp::R_X86_64_COPY:
2278       return;
2279
2280       // glibc supports these reloc types, but they can overflow.
2281     case elfcpp::R_X86_64_PC32:
2282     case elfcpp::R_X86_64_PC32_BND:
2283       // A PC relative reference is OK against a local symbol or if
2284       // the symbol is defined locally.
2285       if (gsym == NULL
2286           || (!gsym->is_from_dynobj()
2287               && !gsym->is_undefined()
2288               && !gsym->is_preemptible()))
2289         return;
2290       /* Fall through.  */
2291     case elfcpp::R_X86_64_32:
2292       // R_X86_64_32 is OK for x32.
2293       if (size == 32 && r_type == elfcpp::R_X86_64_32)
2294         return;
2295       if (this->issued_non_pic_error_)
2296         return;
2297       gold_assert(parameters->options().output_is_position_independent());
2298       if (gsym == NULL)
2299         object->error(_("requires dynamic R_X86_64_32 reloc which may "
2300                         "overflow at runtime; recompile with -fPIC"));
2301       else
2302         {
2303           const char *r_name;
2304           switch (r_type)
2305             {
2306             case elfcpp::R_X86_64_32:
2307               r_name = "R_X86_64_32";
2308               break;
2309             case elfcpp::R_X86_64_PC32:
2310               r_name = "R_X86_64_PC32";
2311               break;
2312             case elfcpp::R_X86_64_PC32_BND:
2313               r_name = "R_X86_64_PC32_BND";
2314               break;
2315             default:
2316               gold_unreachable();
2317               break;
2318             }
2319           object->error(_("requires dynamic %s reloc against '%s' "
2320                           "which may overflow at runtime; recompile "
2321                           "with -fPIC"),
2322                         r_name, gsym->name());
2323         }
2324       this->issued_non_pic_error_ = true;
2325       return;
2326
2327     default:
2328       // This prevents us from issuing more than one error per reloc
2329       // section.  But we can still wind up issuing more than one
2330       // error per object file.
2331       if (this->issued_non_pic_error_)
2332         return;
2333       gold_assert(parameters->options().output_is_position_independent());
2334       object->error(_("requires unsupported dynamic reloc %u; "
2335                       "recompile with -fPIC"),
2336                     r_type);
2337       this->issued_non_pic_error_ = true;
2338       return;
2339
2340     case elfcpp::R_X86_64_NONE:
2341       gold_unreachable();
2342     }
2343 }
2344
2345 // Return whether we need to make a PLT entry for a relocation of the
2346 // given type against a STT_GNU_IFUNC symbol.
2347
2348 template<int size>
2349 bool
2350 Target_x86_64<size>::Scan::reloc_needs_plt_for_ifunc(
2351      Sized_relobj_file<size, false>* object,
2352      unsigned int r_type)
2353 {
2354   int flags = Scan::get_reference_flags(r_type);
2355   if (flags & Symbol::TLS_REF)
2356     gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
2357                object->name().c_str(), r_type);
2358   return flags != 0;
2359 }
2360
2361 // Scan a relocation for a local symbol.
2362
2363 template<int size>
2364 inline void
2365 Target_x86_64<size>::Scan::local(Symbol_table* symtab,
2366                                  Layout* layout,
2367                                  Target_x86_64<size>* target,
2368                                  Sized_relobj_file<size, false>* object,
2369                                  unsigned int data_shndx,
2370                                  Output_section* output_section,
2371                                  const elfcpp::Rela<size, false>& reloc,
2372                                  unsigned int r_type,
2373                                  const elfcpp::Sym<size, false>& lsym,
2374                                  bool is_discarded)
2375 {
2376   if (is_discarded)
2377     return;
2378
2379   // A local STT_GNU_IFUNC symbol may require a PLT entry.
2380   bool is_ifunc = lsym.get_st_type() == elfcpp::STT_GNU_IFUNC;
2381   if (is_ifunc && this->reloc_needs_plt_for_ifunc(object, r_type))
2382     {
2383       unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2384       target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
2385     }
2386
2387   switch (r_type)
2388     {
2389     case elfcpp::R_X86_64_NONE:
2390     case elfcpp::R_X86_64_GNU_VTINHERIT:
2391     case elfcpp::R_X86_64_GNU_VTENTRY:
2392       break;
2393
2394     case elfcpp::R_X86_64_64:
2395       // If building a shared library (or a position-independent
2396       // executable), we need to create a dynamic relocation for this
2397       // location.  The relocation applied at link time will apply the
2398       // link-time value, so we flag the location with an
2399       // R_X86_64_RELATIVE relocation so the dynamic loader can
2400       // relocate it easily.
2401       if (parameters->options().output_is_position_independent())
2402         {
2403           unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2404           Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2405           rela_dyn->add_local_relative(object, r_sym,
2406                                        (size == 32
2407                                         ? elfcpp::R_X86_64_RELATIVE64
2408                                         : elfcpp::R_X86_64_RELATIVE),
2409                                        output_section, data_shndx,
2410                                        reloc.get_r_offset(),
2411                                        reloc.get_r_addend(), is_ifunc);
2412         }
2413       break;
2414
2415     case elfcpp::R_X86_64_32:
2416     case elfcpp::R_X86_64_32S:
2417     case elfcpp::R_X86_64_16:
2418     case elfcpp::R_X86_64_8:
2419       // If building a shared library (or a position-independent
2420       // executable), we need to create a dynamic relocation for this
2421       // location.  We can't use an R_X86_64_RELATIVE relocation
2422       // because that is always a 64-bit relocation.
2423       if (parameters->options().output_is_position_independent())
2424         {
2425           // Use R_X86_64_RELATIVE relocation for R_X86_64_32 under x32.
2426           if (size == 32 && r_type == elfcpp::R_X86_64_32)
2427             {
2428               unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2429               Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2430               rela_dyn->add_local_relative(object, r_sym,
2431                                            elfcpp::R_X86_64_RELATIVE,
2432                                            output_section, data_shndx,
2433                                            reloc.get_r_offset(),
2434                                            reloc.get_r_addend(), is_ifunc);
2435               break;
2436             }
2437
2438           this->check_non_pic(object, r_type, NULL);
2439
2440           Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2441           unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2442           if (lsym.get_st_type() != elfcpp::STT_SECTION)
2443             rela_dyn->add_local(object, r_sym, r_type, output_section,
2444                                 data_shndx, reloc.get_r_offset(),
2445                                 reloc.get_r_addend());
2446           else
2447             {
2448               gold_assert(lsym.get_st_value() == 0);
2449               unsigned int shndx = lsym.get_st_shndx();
2450               bool is_ordinary;
2451               shndx = object->adjust_sym_shndx(r_sym, shndx,
2452                                                &is_ordinary);
2453               if (!is_ordinary)
2454                 object->error(_("section symbol %u has bad shndx %u"),
2455                               r_sym, shndx);
2456               else
2457                 rela_dyn->add_local_section(object, shndx,
2458                                             r_type, output_section,
2459                                             data_shndx, reloc.get_r_offset(),
2460                                             reloc.get_r_addend());
2461             }
2462         }
2463       break;
2464
2465     case elfcpp::R_X86_64_PC64:
2466     case elfcpp::R_X86_64_PC32:
2467     case elfcpp::R_X86_64_PC32_BND:
2468     case elfcpp::R_X86_64_PC16:
2469     case elfcpp::R_X86_64_PC8:
2470       break;
2471
2472     case elfcpp::R_X86_64_PLT32:
2473     case elfcpp::R_X86_64_PLT32_BND:
2474       // Since we know this is a local symbol, we can handle this as a
2475       // PC32 reloc.
2476       break;
2477
2478     case elfcpp::R_X86_64_GOTPC32:
2479     case elfcpp::R_X86_64_GOTOFF64:
2480     case elfcpp::R_X86_64_GOTPC64:
2481     case elfcpp::R_X86_64_PLTOFF64:
2482       // We need a GOT section.
2483       target->got_section(symtab, layout);
2484       // For PLTOFF64, we'd normally want a PLT section, but since we
2485       // know this is a local symbol, no PLT is needed.
2486       break;
2487
2488     case elfcpp::R_X86_64_GOT64:
2489     case elfcpp::R_X86_64_GOT32:
2490     case elfcpp::R_X86_64_GOTPCREL64:
2491     case elfcpp::R_X86_64_GOTPCREL:
2492     case elfcpp::R_X86_64_GOTPCRELX:
2493     case elfcpp::R_X86_64_REX_GOTPCRELX:
2494     case elfcpp::R_X86_64_GOTPLT64:
2495       {
2496         // The symbol requires a GOT section.
2497         Output_data_got<64, false>* got = target->got_section(symtab, layout);
2498
2499         // If the relocation symbol isn't IFUNC,
2500         // and is local, then we will convert
2501         // mov foo@GOTPCREL(%rip), %reg
2502         // to lea foo(%rip), %reg.
2503         // in Relocate::relocate.
2504         if ((r_type == elfcpp::R_X86_64_GOTPCREL
2505              || r_type == elfcpp::R_X86_64_GOTPCRELX
2506              || r_type == elfcpp::R_X86_64_REX_GOTPCRELX)
2507             && reloc.get_r_offset() >= 2
2508             && !is_ifunc)
2509           {
2510             section_size_type stype;
2511             const unsigned char* view = object->section_contents(data_shndx,
2512                                                                  &stype, true);
2513             if (view[reloc.get_r_offset() - 2] == 0x8b)
2514               break;
2515           }
2516
2517
2518         // The symbol requires a GOT entry.
2519         unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2520
2521         // For a STT_GNU_IFUNC symbol we want the PLT offset.  That
2522         // lets function pointers compare correctly with shared
2523         // libraries.  Otherwise we would need an IRELATIVE reloc.
2524         bool is_new;
2525         if (is_ifunc)
2526           is_new = got->add_local_plt(object, r_sym, GOT_TYPE_STANDARD);
2527         else
2528           is_new = got->add_local(object, r_sym, GOT_TYPE_STANDARD);
2529         if (is_new)
2530           {
2531             // If we are generating a shared object, we need to add a
2532             // dynamic relocation for this symbol's GOT entry.
2533             if (parameters->options().output_is_position_independent())
2534               {
2535                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2536                 // R_X86_64_RELATIVE assumes a 64-bit relocation.
2537                 if (r_type != elfcpp::R_X86_64_GOT32)
2538                   {
2539                     unsigned int got_offset =
2540                       object->local_got_offset(r_sym, GOT_TYPE_STANDARD);
2541                     rela_dyn->add_local_relative(object, r_sym,
2542                                                  elfcpp::R_X86_64_RELATIVE,
2543                                                  got, got_offset, 0, is_ifunc);
2544                   }
2545                 else
2546                   {
2547                     this->check_non_pic(object, r_type, NULL);
2548
2549                     gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
2550                     rela_dyn->add_local(
2551                         object, r_sym, r_type, got,
2552                         object->local_got_offset(r_sym, GOT_TYPE_STANDARD), 0);
2553                   }
2554               }
2555           }
2556         // For GOTPLT64, we'd normally want a PLT section, but since
2557         // we know this is a local symbol, no PLT is needed.
2558       }
2559       break;
2560
2561     case elfcpp::R_X86_64_COPY:
2562     case elfcpp::R_X86_64_GLOB_DAT:
2563     case elfcpp::R_X86_64_JUMP_SLOT:
2564     case elfcpp::R_X86_64_RELATIVE:
2565     case elfcpp::R_X86_64_IRELATIVE:
2566       // These are outstanding tls relocs, which are unexpected when linking
2567     case elfcpp::R_X86_64_TPOFF64:
2568     case elfcpp::R_X86_64_DTPMOD64:
2569     case elfcpp::R_X86_64_TLSDESC:
2570       gold_error(_("%s: unexpected reloc %u in object file"),
2571                  object->name().c_str(), r_type);
2572       break;
2573
2574       // These are initial tls relocs, which are expected when linking
2575     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
2576     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
2577     case elfcpp::R_X86_64_TLSDESC_CALL:
2578     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
2579     case elfcpp::R_X86_64_DTPOFF32:
2580     case elfcpp::R_X86_64_DTPOFF64:
2581     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
2582     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
2583       {
2584         bool output_is_shared = parameters->options().shared();
2585         const tls::Tls_optimization optimized_type
2586             = Target_x86_64<size>::optimize_tls_reloc(!output_is_shared,
2587                                                       r_type);
2588         switch (r_type)
2589           {
2590           case elfcpp::R_X86_64_TLSGD:       // General-dynamic
2591             if (optimized_type == tls::TLSOPT_NONE)
2592               {
2593                 // Create a pair of GOT entries for the module index and
2594                 // dtv-relative offset.
2595                 Output_data_got<64, false>* got
2596                     = target->got_section(symtab, layout);
2597                 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2598                 unsigned int shndx = lsym.get_st_shndx();
2599                 bool is_ordinary;
2600                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
2601                 if (!is_ordinary)
2602                   object->error(_("local symbol %u has bad shndx %u"),
2603                               r_sym, shndx);
2604                 else
2605                   got->add_local_pair_with_rel(object, r_sym,
2606                                                shndx,
2607                                                GOT_TYPE_TLS_PAIR,
2608                                                target->rela_dyn_section(layout),
2609                                                elfcpp::R_X86_64_DTPMOD64);
2610               }
2611             else if (optimized_type != tls::TLSOPT_TO_LE)
2612               unsupported_reloc_local(object, r_type);
2613             break;
2614
2615           case elfcpp::R_X86_64_GOTPC32_TLSDESC:
2616             target->define_tls_base_symbol(symtab, layout);
2617             if (optimized_type == tls::TLSOPT_NONE)
2618               {
2619                 // Create reserved PLT and GOT entries for the resolver.
2620                 target->reserve_tlsdesc_entries(symtab, layout);
2621
2622                 // Generate a double GOT entry with an
2623                 // R_X86_64_TLSDESC reloc.  The R_X86_64_TLSDESC reloc
2624                 // is resolved lazily, so the GOT entry needs to be in
2625                 // an area in .got.plt, not .got.  Call got_section to
2626                 // make sure the section has been created.
2627                 target->got_section(symtab, layout);
2628                 Output_data_got<64, false>* got = target->got_tlsdesc_section();
2629                 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2630                 if (!object->local_has_got_offset(r_sym, GOT_TYPE_TLS_DESC))
2631                   {
2632                     unsigned int got_offset = got->add_constant(0);
2633                     got->add_constant(0);
2634                     object->set_local_got_offset(r_sym, GOT_TYPE_TLS_DESC,
2635                                                  got_offset);
2636                     Reloc_section* rt = target->rela_tlsdesc_section(layout);
2637                     // We store the arguments we need in a vector, and
2638                     // use the index into the vector as the parameter
2639                     // to pass to the target specific routines.
2640                     uintptr_t intarg = target->add_tlsdesc_info(object, r_sym);
2641                     void* arg = reinterpret_cast<void*>(intarg);
2642                     rt->add_target_specific(elfcpp::R_X86_64_TLSDESC, arg,
2643                                             got, got_offset, 0);
2644                   }
2645               }
2646             else if (optimized_type != tls::TLSOPT_TO_LE)
2647               unsupported_reloc_local(object, r_type);
2648             break;
2649
2650           case elfcpp::R_X86_64_TLSDESC_CALL:
2651             break;
2652
2653           case elfcpp::R_X86_64_TLSLD:       // Local-dynamic
2654             if (optimized_type == tls::TLSOPT_NONE)
2655               {
2656                 // Create a GOT entry for the module index.
2657                 target->got_mod_index_entry(symtab, layout, object);
2658               }
2659             else if (optimized_type != tls::TLSOPT_TO_LE)
2660               unsupported_reloc_local(object, r_type);
2661             break;
2662
2663           case elfcpp::R_X86_64_DTPOFF32:
2664           case elfcpp::R_X86_64_DTPOFF64:
2665             break;
2666
2667           case elfcpp::R_X86_64_GOTTPOFF:    // Initial-exec
2668             layout->set_has_static_tls();
2669             if (optimized_type == tls::TLSOPT_NONE)
2670               {
2671                 // Create a GOT entry for the tp-relative offset.
2672                 Output_data_got<64, false>* got
2673                     = target->got_section(symtab, layout);
2674                 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2675                 got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
2676                                         target->rela_dyn_section(layout),
2677                                         elfcpp::R_X86_64_TPOFF64);
2678               }
2679             else if (optimized_type != tls::TLSOPT_TO_LE)
2680               unsupported_reloc_local(object, r_type);
2681             break;
2682
2683           case elfcpp::R_X86_64_TPOFF32:     // Local-exec
2684             layout->set_has_static_tls();
2685             if (output_is_shared)
2686               unsupported_reloc_local(object, r_type);
2687             break;
2688
2689           default:
2690             gold_unreachable();
2691           }
2692       }
2693       break;
2694
2695     case elfcpp::R_X86_64_SIZE32:
2696     case elfcpp::R_X86_64_SIZE64:
2697     default:
2698       gold_error(_("%s: unsupported reloc %u against local symbol"),
2699                  object->name().c_str(), r_type);
2700       break;
2701     }
2702 }
2703
2704
2705 // Report an unsupported relocation against a global symbol.
2706
2707 template<int size>
2708 void
2709 Target_x86_64<size>::Scan::unsupported_reloc_global(
2710     Sized_relobj_file<size, false>* object,
2711     unsigned int r_type,
2712     Symbol* gsym)
2713 {
2714   gold_error(_("%s: unsupported reloc %u against global symbol %s"),
2715              object->name().c_str(), r_type, gsym->demangled_name().c_str());
2716 }
2717
2718 // Returns true if this relocation type could be that of a function pointer.
2719 template<int size>
2720 inline bool
2721 Target_x86_64<size>::Scan::possible_function_pointer_reloc(unsigned int r_type)
2722 {
2723   switch (r_type)
2724     {
2725     case elfcpp::R_X86_64_64:
2726     case elfcpp::R_X86_64_32:
2727     case elfcpp::R_X86_64_32S:
2728     case elfcpp::R_X86_64_16:
2729     case elfcpp::R_X86_64_8:
2730     case elfcpp::R_X86_64_GOT64:
2731     case elfcpp::R_X86_64_GOT32:
2732     case elfcpp::R_X86_64_GOTPCREL64:
2733     case elfcpp::R_X86_64_GOTPCREL:
2734     case elfcpp::R_X86_64_GOTPCRELX:
2735     case elfcpp::R_X86_64_REX_GOTPCRELX:
2736     case elfcpp::R_X86_64_GOTPLT64:
2737       {
2738         return true;
2739       }
2740     }
2741   return false;
2742 }
2743
2744 // For safe ICF, scan a relocation for a local symbol to check if it
2745 // corresponds to a function pointer being taken.  In that case mark
2746 // the function whose pointer was taken as not foldable.
2747
2748 template<int size>
2749 inline bool
2750 Target_x86_64<size>::Scan::local_reloc_may_be_function_pointer(
2751   Symbol_table* ,
2752   Layout* ,
2753   Target_x86_64<size>* ,
2754   Sized_relobj_file<size, false>* ,
2755   unsigned int ,
2756   Output_section* ,
2757   const elfcpp::Rela<size, false>& ,
2758   unsigned int r_type,
2759   const elfcpp::Sym<size, false>&)
2760 {
2761   // When building a shared library, do not fold any local symbols as it is
2762   // not possible to distinguish pointer taken versus a call by looking at
2763   // the relocation types.
2764   return (parameters->options().shared()
2765           || possible_function_pointer_reloc(r_type));
2766 }
2767
2768 // For safe ICF, scan a relocation for a global symbol to check if it
2769 // corresponds to a function pointer being taken.  In that case mark
2770 // the function whose pointer was taken as not foldable.
2771
2772 template<int size>
2773 inline bool
2774 Target_x86_64<size>::Scan::global_reloc_may_be_function_pointer(
2775   Symbol_table*,
2776   Layout* ,
2777   Target_x86_64<size>* ,
2778   Sized_relobj_file<size, false>* ,
2779   unsigned int ,
2780   Output_section* ,
2781   const elfcpp::Rela<size, false>& ,
2782   unsigned int r_type,
2783   Symbol* gsym)
2784 {
2785   // When building a shared library, do not fold symbols whose visibility
2786   // is hidden, internal or protected.
2787   return ((parameters->options().shared()
2788            && (gsym->visibility() == elfcpp::STV_INTERNAL
2789                || gsym->visibility() == elfcpp::STV_PROTECTED
2790                || gsym->visibility() == elfcpp::STV_HIDDEN))
2791           || possible_function_pointer_reloc(r_type));
2792 }
2793
2794 // Scan a relocation for a global symbol.
2795
2796 template<int size>
2797 inline void
2798 Target_x86_64<size>::Scan::global(Symbol_table* symtab,
2799                             Layout* layout,
2800                             Target_x86_64<size>* target,
2801                             Sized_relobj_file<size, false>* object,
2802                             unsigned int data_shndx,
2803                             Output_section* output_section,
2804                             const elfcpp::Rela<size, false>& reloc,
2805                             unsigned int r_type,
2806                             Symbol* gsym)
2807 {
2808   // A STT_GNU_IFUNC symbol may require a PLT entry.
2809   if (gsym->type() == elfcpp::STT_GNU_IFUNC
2810       && this->reloc_needs_plt_for_ifunc(object, r_type))
2811     target->make_plt_entry(symtab, layout, gsym);
2812
2813   switch (r_type)
2814     {
2815     case elfcpp::R_X86_64_NONE:
2816     case elfcpp::R_X86_64_GNU_VTINHERIT:
2817     case elfcpp::R_X86_64_GNU_VTENTRY:
2818       break;
2819
2820     case elfcpp::R_X86_64_64:
2821     case elfcpp::R_X86_64_32:
2822     case elfcpp::R_X86_64_32S:
2823     case elfcpp::R_X86_64_16:
2824     case elfcpp::R_X86_64_8:
2825       {
2826         // Make a PLT entry if necessary.
2827         if (gsym->needs_plt_entry())
2828           {
2829             target->make_plt_entry(symtab, layout, gsym);
2830             // Since this is not a PC-relative relocation, we may be
2831             // taking the address of a function. In that case we need to
2832             // set the entry in the dynamic symbol table to the address of
2833             // the PLT entry.
2834             if (gsym->is_from_dynobj() && !parameters->options().shared())
2835               gsym->set_needs_dynsym_value();
2836           }
2837         // Make a dynamic relocation if necessary.
2838         if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
2839           {
2840             if (!parameters->options().output_is_position_independent()
2841                 && gsym->may_need_copy_reloc())
2842               {
2843                 target->copy_reloc(symtab, layout, object,
2844                                    data_shndx, output_section, gsym, reloc);
2845               }
2846             else if (((size == 64 && r_type == elfcpp::R_X86_64_64)
2847                       || (size == 32 && r_type == elfcpp::R_X86_64_32))
2848                      && gsym->type() == elfcpp::STT_GNU_IFUNC
2849                      && gsym->can_use_relative_reloc(false)
2850                      && !gsym->is_from_dynobj()
2851                      && !gsym->is_undefined()
2852                      && !gsym->is_preemptible())
2853               {
2854                 // Use an IRELATIVE reloc for a locally defined
2855                 // STT_GNU_IFUNC symbol.  This makes a function
2856                 // address in a PIE executable match the address in a
2857                 // shared library that it links against.
2858                 Reloc_section* rela_dyn =
2859                   target->rela_irelative_section(layout);
2860                 unsigned int r_type = elfcpp::R_X86_64_IRELATIVE;
2861                 rela_dyn->add_symbolless_global_addend(gsym, r_type,
2862                                                        output_section, object,
2863                                                        data_shndx,
2864                                                        reloc.get_r_offset(),
2865                                                        reloc.get_r_addend());
2866               }
2867             else if (((size == 64 && r_type == elfcpp::R_X86_64_64)
2868                       || (size == 32 && r_type == elfcpp::R_X86_64_32))
2869                      && gsym->can_use_relative_reloc(false))
2870               {
2871                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2872                 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_RELATIVE,
2873                                               output_section, object,
2874                                               data_shndx,
2875                                               reloc.get_r_offset(),
2876                                               reloc.get_r_addend(), false);
2877               }
2878             else
2879               {
2880                 this->check_non_pic(object, r_type, gsym);
2881                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2882                 rela_dyn->add_global(gsym, r_type, output_section, object,
2883                                      data_shndx, reloc.get_r_offset(),
2884                                      reloc.get_r_addend());
2885               }
2886           }
2887       }
2888       break;
2889
2890     case elfcpp::R_X86_64_PC64:
2891     case elfcpp::R_X86_64_PC32:
2892     case elfcpp::R_X86_64_PC32_BND:
2893     case elfcpp::R_X86_64_PC16:
2894     case elfcpp::R_X86_64_PC8:
2895       {
2896         // Make a PLT entry if necessary.
2897         if (gsym->needs_plt_entry())
2898           target->make_plt_entry(symtab, layout, gsym);
2899         // Make a dynamic relocation if necessary.
2900         if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
2901           {
2902             if (parameters->options().output_is_executable()
2903                 && gsym->may_need_copy_reloc())
2904               {
2905                 target->copy_reloc(symtab, layout, object,
2906                                    data_shndx, output_section, gsym, reloc);
2907               }
2908             else
2909               {
2910                 this->check_non_pic(object, r_type, gsym);
2911                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2912                 rela_dyn->add_global(gsym, r_type, output_section, object,
2913                                      data_shndx, reloc.get_r_offset(),
2914                                      reloc.get_r_addend());
2915               }
2916           }
2917       }
2918       break;
2919
2920     case elfcpp::R_X86_64_GOT64:
2921     case elfcpp::R_X86_64_GOT32:
2922     case elfcpp::R_X86_64_GOTPCREL64:
2923     case elfcpp::R_X86_64_GOTPCREL:
2924     case elfcpp::R_X86_64_GOTPCRELX:
2925     case elfcpp::R_X86_64_REX_GOTPCRELX:
2926     case elfcpp::R_X86_64_GOTPLT64:
2927       {
2928         // The symbol requires a GOT entry.
2929         Output_data_got<64, false>* got = target->got_section(symtab, layout);
2930
2931         // If we convert this from
2932         // mov foo@GOTPCREL(%rip), %reg
2933         // to lea foo(%rip), %reg.
2934         // in Relocate::relocate, then there is nothing to do here.
2935         if ((r_type == elfcpp::R_X86_64_GOTPCREL
2936              || r_type == elfcpp::R_X86_64_GOTPCRELX
2937              || r_type == elfcpp::R_X86_64_REX_GOTPCRELX)
2938             && reloc.get_r_offset() >= 2
2939             && Target_x86_64<size>::can_convert_mov_to_lea(gsym))
2940           {
2941             section_size_type stype;
2942             const unsigned char* view = object->section_contents(data_shndx,
2943                                                                  &stype, true);
2944             if (view[reloc.get_r_offset() - 2] == 0x8b)
2945               break;
2946           }
2947
2948         if (gsym->final_value_is_known())
2949           {
2950             // For a STT_GNU_IFUNC symbol we want the PLT address.
2951             if (gsym->type() == elfcpp::STT_GNU_IFUNC)
2952               got->add_global_plt(gsym, GOT_TYPE_STANDARD);
2953             else
2954               got->add_global(gsym, GOT_TYPE_STANDARD);
2955           }
2956         else
2957           {
2958             // If this symbol is not fully resolved, we need to add a
2959             // dynamic relocation for it.
2960             Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2961
2962             // Use a GLOB_DAT rather than a RELATIVE reloc if:
2963             //
2964             // 1) The symbol may be defined in some other module.
2965             //
2966             // 2) We are building a shared library and this is a
2967             // protected symbol; using GLOB_DAT means that the dynamic
2968             // linker can use the address of the PLT in the main
2969             // executable when appropriate so that function address
2970             // comparisons work.
2971             //
2972             // 3) This is a STT_GNU_IFUNC symbol in position dependent
2973             // code, again so that function address comparisons work.
2974             if (gsym->is_from_dynobj()
2975                 || gsym->is_undefined()
2976                 || gsym->is_preemptible()
2977                 || (gsym->visibility() == elfcpp::STV_PROTECTED
2978                     && parameters->options().shared())
2979                 || (gsym->type() == elfcpp::STT_GNU_IFUNC
2980                     && parameters->options().output_is_position_independent()))
2981               got->add_global_with_rel(gsym, GOT_TYPE_STANDARD, rela_dyn,
2982                                        elfcpp::R_X86_64_GLOB_DAT);
2983             else
2984               {
2985                 // For a STT_GNU_IFUNC symbol we want to write the PLT
2986                 // offset into the GOT, so that function pointer
2987                 // comparisons work correctly.
2988                 bool is_new;
2989                 if (gsym->type() != elfcpp::STT_GNU_IFUNC)
2990                   is_new = got->add_global(gsym, GOT_TYPE_STANDARD);
2991                 else
2992                   {
2993                     is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD);
2994                     // Tell the dynamic linker to use the PLT address
2995                     // when resolving relocations.
2996                     if (gsym->is_from_dynobj()
2997                         && !parameters->options().shared())
2998                       gsym->set_needs_dynsym_value();
2999                   }
3000                 if (is_new)
3001                   {
3002                     unsigned int got_off = gsym->got_offset(GOT_TYPE_STANDARD);
3003                     rela_dyn->add_global_relative(gsym,
3004                                                   elfcpp::R_X86_64_RELATIVE,
3005                                                   got, got_off, 0, false);
3006                   }
3007               }
3008           }
3009       }
3010       break;
3011
3012     case elfcpp::R_X86_64_PLT32:
3013     case elfcpp::R_X86_64_PLT32_BND:
3014       // If the symbol is fully resolved, this is just a PC32 reloc.
3015       // Otherwise we need a PLT entry.
3016       if (gsym->final_value_is_known())
3017         break;
3018       // If building a shared library, we can also skip the PLT entry
3019       // if the symbol is defined in the output file and is protected
3020       // or hidden.
3021       if (gsym->is_defined()
3022           && !gsym->is_from_dynobj()
3023           && !gsym->is_preemptible())
3024         break;
3025       target->make_plt_entry(symtab, layout, gsym);
3026       break;
3027
3028     case elfcpp::R_X86_64_GOTPC32:
3029     case elfcpp::R_X86_64_GOTOFF64:
3030     case elfcpp::R_X86_64_GOTPC64:
3031     case elfcpp::R_X86_64_PLTOFF64:
3032       // We need a GOT section.
3033       target->got_section(symtab, layout);
3034       // For PLTOFF64, we also need a PLT entry (but only if the
3035       // symbol is not fully resolved).
3036       if (r_type == elfcpp::R_X86_64_PLTOFF64
3037           && !gsym->final_value_is_known())
3038         target->make_plt_entry(symtab, layout, gsym);
3039       break;
3040
3041     case elfcpp::R_X86_64_COPY:
3042     case elfcpp::R_X86_64_GLOB_DAT:
3043     case elfcpp::R_X86_64_JUMP_SLOT:
3044     case elfcpp::R_X86_64_RELATIVE:
3045     case elfcpp::R_X86_64_IRELATIVE:
3046       // These are outstanding tls relocs, which are unexpected when linking
3047     case elfcpp::R_X86_64_TPOFF64:
3048     case elfcpp::R_X86_64_DTPMOD64:
3049     case elfcpp::R_X86_64_TLSDESC:
3050       gold_error(_("%s: unexpected reloc %u in object file"),
3051                  object->name().c_str(), r_type);
3052       break;
3053
3054       // These are initial tls relocs, which are expected for global()
3055     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
3056     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
3057     case elfcpp::R_X86_64_TLSDESC_CALL:
3058     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
3059     case elfcpp::R_X86_64_DTPOFF32:
3060     case elfcpp::R_X86_64_DTPOFF64:
3061     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
3062     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
3063       {
3064         // For the Initial-Exec model, we can treat undef symbols as final
3065         // when building an executable.
3066         const bool is_final = (gsym->final_value_is_known() ||
3067                                (r_type == elfcpp::R_X86_64_GOTTPOFF &&
3068                                 gsym->is_undefined() &&
3069                                 parameters->options().output_is_executable()));
3070         const tls::Tls_optimization optimized_type
3071             = Target_x86_64<size>::optimize_tls_reloc(is_final, r_type);
3072         switch (r_type)
3073           {
3074           case elfcpp::R_X86_64_TLSGD:       // General-dynamic
3075             if (optimized_type == tls::TLSOPT_NONE)
3076               {
3077                 // Create a pair of GOT entries for the module index and
3078                 // dtv-relative offset.
3079                 Output_data_got<64, false>* got
3080                     = target->got_section(symtab, layout);
3081                 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
3082                                               target->rela_dyn_section(layout),
3083                                               elfcpp::R_X86_64_DTPMOD64,
3084                                               elfcpp::R_X86_64_DTPOFF64);
3085               }
3086             else if (optimized_type == tls::TLSOPT_TO_IE)
3087               {
3088                 // Create a GOT entry for the tp-relative offset.
3089                 Output_data_got<64, false>* got
3090                     = target->got_section(symtab, layout);
3091                 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
3092                                          target->rela_dyn_section(layout),
3093                                          elfcpp::R_X86_64_TPOFF64);
3094               }
3095             else if (optimized_type != tls::TLSOPT_TO_LE)
3096               unsupported_reloc_global(object, r_type, gsym);
3097             break;
3098
3099           case elfcpp::R_X86_64_GOTPC32_TLSDESC:
3100             target->define_tls_base_symbol(symtab, layout);
3101             if (optimized_type == tls::TLSOPT_NONE)
3102               {
3103                 // Create reserved PLT and GOT entries for the resolver.
3104                 target->reserve_tlsdesc_entries(symtab, layout);
3105
3106                 // Create a double GOT entry with an R_X86_64_TLSDESC
3107                 // reloc.  The R_X86_64_TLSDESC reloc is resolved
3108                 // lazily, so the GOT entry needs to be in an area in
3109                 // .got.plt, not .got.  Call got_section to make sure
3110                 // the section has been created.
3111                 target->got_section(symtab, layout);
3112                 Output_data_got<64, false>* got = target->got_tlsdesc_section();
3113                 Reloc_section* rt = target->rela_tlsdesc_section(layout);
3114                 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC, rt,
3115                                               elfcpp::R_X86_64_TLSDESC, 0);
3116               }
3117             else if (optimized_type == tls::TLSOPT_TO_IE)
3118               {
3119                 // Create a GOT entry for the tp-relative offset.
3120                 Output_data_got<64, false>* got
3121                     = target->got_section(symtab, layout);
3122                 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
3123                                          target->rela_dyn_section(layout),
3124                                          elfcpp::R_X86_64_TPOFF64);
3125               }
3126             else if (optimized_type != tls::TLSOPT_TO_LE)
3127               unsupported_reloc_global(object, r_type, gsym);
3128             break;
3129
3130           case elfcpp::R_X86_64_TLSDESC_CALL:
3131             break;
3132
3133           case elfcpp::R_X86_64_TLSLD:       // Local-dynamic
3134             if (optimized_type == tls::TLSOPT_NONE)
3135               {
3136                 // Create a GOT entry for the module index.
3137                 target->got_mod_index_entry(symtab, layout, object);
3138               }
3139             else if (optimized_type != tls::TLSOPT_TO_LE)
3140               unsupported_reloc_global(object, r_type, gsym);
3141             break;
3142
3143           case elfcpp::R_X86_64_DTPOFF32:
3144           case elfcpp::R_X86_64_DTPOFF64:
3145             break;
3146
3147           case elfcpp::R_X86_64_GOTTPOFF:    // Initial-exec
3148             layout->set_has_static_tls();
3149             if (optimized_type == tls::TLSOPT_NONE)
3150               {
3151                 // Create a GOT entry for the tp-relative offset.
3152                 Output_data_got<64, false>* got
3153                     = target->got_section(symtab, layout);
3154                 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
3155                                          target->rela_dyn_section(layout),
3156                                          elfcpp::R_X86_64_TPOFF64);
3157               }
3158             else if (optimized_type != tls::TLSOPT_TO_LE)
3159               unsupported_reloc_global(object, r_type, gsym);
3160             break;
3161
3162           case elfcpp::R_X86_64_TPOFF32:     // Local-exec
3163             layout->set_has_static_tls();
3164             if (parameters->options().shared())
3165               unsupported_reloc_global(object, r_type, gsym);
3166             break;
3167
3168           default:
3169             gold_unreachable();
3170           }
3171       }
3172       break;
3173
3174     case elfcpp::R_X86_64_SIZE32:
3175     case elfcpp::R_X86_64_SIZE64:
3176     default:
3177       gold_error(_("%s: unsupported reloc %u against global symbol %s"),
3178                  object->name().c_str(), r_type,
3179                  gsym->demangled_name().c_str());
3180       break;
3181     }
3182 }
3183
3184 template<int size>
3185 void
3186 Target_x86_64<size>::gc_process_relocs(Symbol_table* symtab,
3187                                        Layout* layout,
3188                                        Sized_relobj_file<size, false>* object,
3189                                        unsigned int data_shndx,
3190                                        unsigned int sh_type,
3191                                        const unsigned char* prelocs,
3192                                        size_t reloc_count,
3193                                        Output_section* output_section,
3194                                        bool needs_special_offset_handling,
3195                                        size_t local_symbol_count,
3196                                        const unsigned char* plocal_symbols)
3197 {
3198   typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
3199       Classify_reloc;
3200
3201   if (sh_type == elfcpp::SHT_REL)
3202     {
3203       return;
3204     }
3205
3206    gold::gc_process_relocs<size, false, Target_x86_64<size>, Scan,
3207                            Classify_reloc>(
3208     symtab,
3209     layout,
3210     this,
3211     object,
3212     data_shndx,
3213     prelocs,
3214     reloc_count,
3215     output_section,
3216     needs_special_offset_handling,
3217     local_symbol_count,
3218     plocal_symbols);
3219
3220 }
3221 // Scan relocations for a section.
3222
3223 template<int size>
3224 void
3225 Target_x86_64<size>::scan_relocs(Symbol_table* symtab,
3226                                  Layout* layout,
3227                                  Sized_relobj_file<size, false>* object,
3228                                  unsigned int data_shndx,
3229                                  unsigned int sh_type,
3230                                  const unsigned char* prelocs,
3231                                  size_t reloc_count,
3232                                  Output_section* output_section,
3233                                  bool needs_special_offset_handling,
3234                                  size_t local_symbol_count,
3235                                  const unsigned char* plocal_symbols)
3236 {
3237   typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
3238       Classify_reloc;
3239
3240   if (sh_type == elfcpp::SHT_REL)
3241     {
3242       gold_error(_("%s: unsupported REL reloc section"),
3243                  object->name().c_str());
3244       return;
3245     }
3246
3247   gold::scan_relocs<size, false, Target_x86_64<size>, Scan, Classify_reloc>(
3248     symtab,
3249     layout,
3250     this,
3251     object,
3252     data_shndx,
3253     prelocs,
3254     reloc_count,
3255     output_section,
3256     needs_special_offset_handling,
3257     local_symbol_count,
3258     plocal_symbols);
3259 }
3260
3261 // Finalize the sections.
3262
3263 template<int size>
3264 void
3265 Target_x86_64<size>::do_finalize_sections(
3266     Layout* layout,
3267     const Input_objects*,
3268     Symbol_table* symtab)
3269 {
3270   const Reloc_section* rel_plt = (this->plt_ == NULL
3271                                   ? NULL
3272                                   : this->plt_->rela_plt());
3273   layout->add_target_dynamic_tags(false, this->got_plt_, rel_plt,
3274                                   this->rela_dyn_, true, false);
3275
3276   // Fill in some more dynamic tags.
3277   Output_data_dynamic* const odyn = layout->dynamic_data();
3278   if (odyn != NULL)
3279     {
3280       if (this->plt_ != NULL
3281           && this->plt_->output_section() != NULL
3282           && this->plt_->has_tlsdesc_entry())
3283         {
3284           unsigned int plt_offset = this->plt_->get_tlsdesc_plt_offset();
3285           unsigned int got_offset = this->plt_->get_tlsdesc_got_offset();
3286           this->got_->finalize_data_size();
3287           odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_PLT,
3288                                         this->plt_, plt_offset);
3289           odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_GOT,
3290                                         this->got_, got_offset);
3291         }
3292     }
3293
3294   // Emit any relocs we saved in an attempt to avoid generating COPY
3295   // relocs.
3296   if (this->copy_relocs_.any_saved_relocs())
3297     this->copy_relocs_.emit(this->rela_dyn_section(layout));
3298
3299   // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
3300   // the .got.plt section.
3301   Symbol* sym = this->global_offset_table_;
3302   if (sym != NULL)
3303     {
3304       uint64_t data_size = this->got_plt_->current_data_size();
3305       symtab->get_sized_symbol<size>(sym)->set_symsize(data_size);
3306     }
3307
3308   if (parameters->doing_static_link()
3309       && (this->plt_ == NULL || !this->plt_->has_irelative_section()))
3310     {
3311       // If linking statically, make sure that the __rela_iplt symbols
3312       // were defined if necessary, even if we didn't create a PLT.
3313       static const Define_symbol_in_segment syms[] =
3314         {
3315           {
3316             "__rela_iplt_start",        // name
3317             elfcpp::PT_LOAD,            // segment_type
3318             elfcpp::PF_W,               // segment_flags_set
3319             elfcpp::PF(0),              // segment_flags_clear
3320             0,                          // value
3321             0,                          // size
3322             elfcpp::STT_NOTYPE,         // type
3323             elfcpp::STB_GLOBAL,         // binding
3324             elfcpp::STV_HIDDEN,         // visibility
3325             0,                          // nonvis
3326             Symbol::SEGMENT_START,      // offset_from_base
3327             true                        // only_if_ref
3328           },
3329           {
3330             "__rela_iplt_end",          // name
3331             elfcpp::PT_LOAD,            // segment_type
3332             elfcpp::PF_W,               // segment_flags_set
3333             elfcpp::PF(0),              // segment_flags_clear
3334             0,                          // value
3335             0,                          // size
3336             elfcpp::STT_NOTYPE,         // type
3337             elfcpp::STB_GLOBAL,         // binding
3338             elfcpp::STV_HIDDEN,         // visibility
3339             0,                          // nonvis
3340             Symbol::SEGMENT_START,      // offset_from_base
3341             true                        // only_if_ref
3342           }
3343         };
3344
3345       symtab->define_symbols(layout, 2, syms,
3346                              layout->script_options()->saw_sections_clause());
3347     }
3348 }
3349
3350 // For x32, we need to handle PC-relative relocations using full 64-bit
3351 // arithmetic, so that we can detect relocation overflows properly.
3352 // This class overrides the pcrela32_check methods from the defaults in
3353 // Relocate_functions in reloc.h.
3354
3355 template<int size>
3356 class X86_64_relocate_functions : public Relocate_functions<size, false>
3357 {
3358  public:
3359   typedef Relocate_functions<size, false> Base;
3360
3361   // Do a simple PC relative relocation with the addend in the
3362   // relocation.
3363   static inline typename Base::Reloc_status
3364   pcrela32_check(unsigned char* view,
3365                  typename elfcpp::Elf_types<64>::Elf_Addr value,
3366                  typename elfcpp::Elf_types<64>::Elf_Swxword addend,
3367                  typename elfcpp::Elf_types<64>::Elf_Addr address)
3368   {
3369     typedef typename elfcpp::Swap<32, false>::Valtype Valtype;
3370     Valtype* wv = reinterpret_cast<Valtype*>(view);
3371     value = value + addend - address;
3372     elfcpp::Swap<32, false>::writeval(wv, value);
3373     return (Bits<32>::has_overflow(value)
3374             ? Base::RELOC_OVERFLOW : Base::RELOC_OK);
3375   }
3376
3377   // Do a simple PC relative relocation with a Symbol_value with the
3378   // addend in the relocation.
3379   static inline typename Base::Reloc_status
3380   pcrela32_check(unsigned char* view,
3381                  const Sized_relobj_file<size, false>* object,
3382                  const Symbol_value<size>* psymval,
3383                  typename elfcpp::Elf_types<64>::Elf_Swxword addend,
3384                  typename elfcpp::Elf_types<64>::Elf_Addr address)
3385   {
3386     typedef typename elfcpp::Swap<32, false>::Valtype Valtype;
3387     Valtype* wv = reinterpret_cast<Valtype*>(view);
3388     typename elfcpp::Elf_types<64>::Elf_Addr value =
3389         psymval->value(object, addend) - address;
3390     elfcpp::Swap<32, false>::writeval(wv, value);
3391     return (Bits<32>::has_overflow(value)
3392             ? Base::RELOC_OVERFLOW : Base::RELOC_OK);
3393   }
3394 };
3395
3396 // Perform a relocation.
3397
3398 template<int size>
3399 inline bool
3400 Target_x86_64<size>::Relocate::relocate(
3401     const Relocate_info<size, false>* relinfo,
3402     unsigned int,
3403     Target_x86_64<size>* target,
3404     Output_section*,
3405     size_t relnum,
3406     const unsigned char* preloc,
3407     const Sized_symbol<size>* gsym,
3408     const Symbol_value<size>* psymval,
3409     unsigned char* view,
3410     typename elfcpp::Elf_types<size>::Elf_Addr address,
3411     section_size_type view_size)
3412 {
3413   typedef X86_64_relocate_functions<size> Reloc_funcs;
3414   const elfcpp::Rela<size, false> rela(preloc);
3415   unsigned int r_type = elfcpp::elf_r_type<size>(rela.get_r_info());
3416
3417   if (this->skip_call_tls_get_addr_)
3418     {
3419       if ((r_type != elfcpp::R_X86_64_PLT32
3420            && r_type != elfcpp::R_X86_64_PLT32_BND
3421            && r_type != elfcpp::R_X86_64_PC32_BND
3422            && r_type != elfcpp::R_X86_64_PC32)
3423           || gsym == NULL
3424           || strcmp(gsym->name(), "__tls_get_addr") != 0)
3425         {
3426           gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3427                                  _("missing expected TLS relocation"));
3428         }
3429       else
3430         {
3431           this->skip_call_tls_get_addr_ = false;
3432           return false;
3433         }
3434     }
3435
3436   if (view == NULL)
3437     return true;
3438
3439   const Sized_relobj_file<size, false>* object = relinfo->object;
3440
3441   // Pick the value to use for symbols defined in the PLT.
3442   Symbol_value<size> symval;
3443   if (gsym != NULL
3444       && gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
3445     {
3446       symval.set_output_value(target->plt_address_for_global(gsym));
3447       psymval = &symval;
3448     }
3449   else if (gsym == NULL && psymval->is_ifunc_symbol())
3450     {
3451       unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3452       if (object->local_has_plt_offset(r_sym))
3453         {
3454           symval.set_output_value(target->plt_address_for_local(object, r_sym));
3455           psymval = &symval;
3456         }
3457     }
3458
3459   const elfcpp::Elf_Xword addend = rela.get_r_addend();
3460
3461   // Get the GOT offset if needed.
3462   // The GOT pointer points to the end of the GOT section.
3463   // We need to subtract the size of the GOT section to get
3464   // the actual offset to use in the relocation.
3465   bool have_got_offset = false;
3466   // Since the actual offset is always negative, we use signed int to
3467   // support 64-bit GOT relocations.
3468   int got_offset = 0;
3469   switch (r_type)
3470     {
3471     case elfcpp::R_X86_64_GOT32:
3472     case elfcpp::R_X86_64_GOT64:
3473     case elfcpp::R_X86_64_GOTPLT64:
3474     case elfcpp::R_X86_64_GOTPCREL64:
3475       if (gsym != NULL)
3476         {
3477           gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
3478           got_offset = gsym->got_offset(GOT_TYPE_STANDARD) - target->got_size();
3479         }
3480       else
3481         {
3482           unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3483           gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
3484           got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
3485                         - target->got_size());
3486         }
3487       have_got_offset = true;
3488       break;
3489
3490     default:
3491       break;
3492     }
3493
3494   typename Reloc_funcs::Reloc_status rstatus = Reloc_funcs::RELOC_OK;
3495
3496   switch (r_type)
3497     {
3498     case elfcpp::R_X86_64_NONE:
3499     case elfcpp::R_X86_64_GNU_VTINHERIT:
3500     case elfcpp::R_X86_64_GNU_VTENTRY:
3501       break;
3502
3503     case elfcpp::R_X86_64_64:
3504       Reloc_funcs::rela64(view, object, psymval, addend);
3505       break;
3506
3507     case elfcpp::R_X86_64_PC64:
3508       Reloc_funcs::pcrela64(view, object, psymval, addend,
3509                                               address);
3510       break;
3511
3512     case elfcpp::R_X86_64_32:
3513       rstatus = Reloc_funcs::rela32_check(view, object, psymval, addend,
3514                                           Reloc_funcs::CHECK_UNSIGNED);
3515       break;
3516
3517     case elfcpp::R_X86_64_32S:
3518       rstatus = Reloc_funcs::rela32_check(view, object, psymval, addend,
3519                                           Reloc_funcs::CHECK_SIGNED);
3520       break;
3521
3522     case elfcpp::R_X86_64_PC32:
3523     case elfcpp::R_X86_64_PC32_BND:
3524       rstatus = Reloc_funcs::pcrela32_check(view, object, psymval, addend,
3525                                             address);
3526       break;
3527
3528     case elfcpp::R_X86_64_16:
3529       Reloc_funcs::rela16(view, object, psymval, addend);
3530       break;
3531
3532     case elfcpp::R_X86_64_PC16:
3533       Reloc_funcs::pcrela16(view, object, psymval, addend, address);
3534       break;
3535
3536     case elfcpp::R_X86_64_8:
3537       Reloc_funcs::rela8(view, object, psymval, addend);
3538       break;
3539
3540     case elfcpp::R_X86_64_PC8:
3541       Reloc_funcs::pcrela8(view, object, psymval, addend, address);
3542       break;
3543
3544     case elfcpp::R_X86_64_PLT32:
3545     case elfcpp::R_X86_64_PLT32_BND:
3546       gold_assert(gsym == NULL
3547                   || gsym->has_plt_offset()
3548                   || gsym->final_value_is_known()
3549                   || (gsym->is_defined()
3550                       && !gsym->is_from_dynobj()
3551                       && !gsym->is_preemptible()));
3552       // Note: while this code looks the same as for R_X86_64_PC32, it
3553       // behaves differently because psymval was set to point to
3554       // the PLT entry, rather than the symbol, in Scan::global().
3555       rstatus = Reloc_funcs::pcrela32_check(view, object, psymval, addend,
3556                                             address);
3557       break;
3558
3559     case elfcpp::R_X86_64_PLTOFF64:
3560       {
3561         gold_assert(gsym);
3562         gold_assert(gsym->has_plt_offset()
3563                     || gsym->final_value_is_known());
3564         typename elfcpp::Elf_types<size>::Elf_Addr got_address;
3565         // This is the address of GLOBAL_OFFSET_TABLE.
3566         got_address = target->got_plt_section()->address();
3567         Reloc_funcs::rela64(view, object, psymval, addend - got_address);
3568       }
3569       break;
3570
3571     case elfcpp::R_X86_64_GOT32:
3572       gold_assert(have_got_offset);
3573       Reloc_funcs::rela32(view, got_offset, addend);
3574       break;
3575
3576     case elfcpp::R_X86_64_GOTPC32:
3577       {
3578         gold_assert(gsym);
3579         typename elfcpp::Elf_types<size>::Elf_Addr value;
3580         value = target->got_plt_section()->address();
3581         Reloc_funcs::pcrela32_check(view, value, addend, address);
3582       }
3583       break;
3584
3585     case elfcpp::R_X86_64_GOT64:
3586     case elfcpp::R_X86_64_GOTPLT64:
3587       // R_X86_64_GOTPLT64 is obsolete and treated the the same as
3588       // GOT64.
3589       gold_assert(have_got_offset);
3590       Reloc_funcs::rela64(view, got_offset, addend);
3591       break;
3592
3593     case elfcpp::R_X86_64_GOTPC64:
3594       {
3595         gold_assert(gsym);
3596         typename elfcpp::Elf_types<size>::Elf_Addr value;
3597         value = target->got_plt_section()->address();
3598         Reloc_funcs::pcrela64(view, value, addend, address);
3599       }
3600       break;
3601
3602     case elfcpp::R_X86_64_GOTOFF64:
3603       {
3604         typename elfcpp::Elf_types<size>::Elf_Addr value;
3605         value = (psymval->value(object, 0)
3606                  - target->got_plt_section()->address());
3607         Reloc_funcs::rela64(view, value, addend);
3608       }
3609       break;
3610
3611     case elfcpp::R_X86_64_GOTPCREL:
3612     case elfcpp::R_X86_64_GOTPCRELX:
3613     case elfcpp::R_X86_64_REX_GOTPCRELX:
3614       {
3615       // Convert
3616       // mov foo@GOTPCREL(%rip), %reg
3617       // to lea foo(%rip), %reg.
3618       // if possible.
3619       if (rela.get_r_offset() >= 2
3620           && view[-2] == 0x8b
3621           && ((gsym == NULL && !psymval->is_ifunc_symbol())
3622               || (gsym != NULL
3623                   && Target_x86_64<size>::can_convert_mov_to_lea(gsym))))
3624         {
3625           view[-2] = 0x8d;
3626           Reloc_funcs::pcrela32(view, object, psymval, addend, address);
3627         }
3628       else
3629         {
3630           if (gsym != NULL)
3631             {
3632               gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
3633               got_offset = gsym->got_offset(GOT_TYPE_STANDARD) - target->got_size();
3634             }
3635           else
3636             {
3637               unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3638               gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
3639               got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
3640                             - target->got_size());
3641             }
3642           typename elfcpp::Elf_types<size>::Elf_Addr value;
3643           value = target->got_plt_section()->address() + got_offset;
3644           Reloc_funcs::pcrela32_check(view, value, addend, address);
3645         }
3646       }
3647       break;
3648
3649     case elfcpp::R_X86_64_GOTPCREL64:
3650       {
3651         gold_assert(have_got_offset);
3652         typename elfcpp::Elf_types<size>::Elf_Addr value;
3653         value = target->got_plt_section()->address() + got_offset;
3654         Reloc_funcs::pcrela64(view, value, addend, address);
3655       }
3656       break;
3657
3658     case elfcpp::R_X86_64_COPY:
3659     case elfcpp::R_X86_64_GLOB_DAT:
3660     case elfcpp::R_X86_64_JUMP_SLOT:
3661     case elfcpp::R_X86_64_RELATIVE:
3662     case elfcpp::R_X86_64_IRELATIVE:
3663       // These are outstanding tls relocs, which are unexpected when linking
3664     case elfcpp::R_X86_64_TPOFF64:
3665     case elfcpp::R_X86_64_DTPMOD64:
3666     case elfcpp::R_X86_64_TLSDESC:
3667       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3668                              _("unexpected reloc %u in object file"),
3669                              r_type);
3670       break;
3671
3672       // These are initial tls relocs, which are expected when linking
3673     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
3674     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
3675     case elfcpp::R_X86_64_TLSDESC_CALL:
3676     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
3677     case elfcpp::R_X86_64_DTPOFF32:
3678     case elfcpp::R_X86_64_DTPOFF64:
3679     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
3680     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
3681       this->relocate_tls(relinfo, target, relnum, rela, r_type, gsym, psymval,
3682                          view, address, view_size);
3683       break;
3684
3685     case elfcpp::R_X86_64_SIZE32:
3686     case elfcpp::R_X86_64_SIZE64:
3687     default:
3688       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3689                              _("unsupported reloc %u"),
3690                              r_type);
3691       break;
3692     }
3693
3694   if (rstatus == Reloc_funcs::RELOC_OVERFLOW)
3695     gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3696                            _("relocation overflow"));
3697
3698   return true;
3699 }
3700
3701 // Perform a TLS relocation.
3702
3703 template<int size>
3704 inline void
3705 Target_x86_64<size>::Relocate::relocate_tls(
3706     const Relocate_info<size, false>* relinfo,
3707     Target_x86_64<size>* target,
3708     size_t relnum,
3709     const elfcpp::Rela<size, false>& rela,
3710     unsigned int r_type,
3711     const Sized_symbol<size>* gsym,
3712     const Symbol_value<size>* psymval,
3713     unsigned char* view,
3714     typename elfcpp::Elf_types<size>::Elf_Addr address,
3715     section_size_type view_size)
3716 {
3717   Output_segment* tls_segment = relinfo->layout->tls_segment();
3718
3719   const Sized_relobj_file<size, false>* object = relinfo->object;
3720   const elfcpp::Elf_Xword addend = rela.get_r_addend();
3721   elfcpp::Shdr<size, false> data_shdr(relinfo->data_shdr);
3722   bool is_executable = (data_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0;
3723
3724   typename elfcpp::Elf_types<size>::Elf_Addr value = psymval->value(relinfo->object, 0);
3725
3726   const bool is_final = (gsym == NULL
3727                          ? !parameters->options().shared()
3728                          : gsym->final_value_is_known());
3729   tls::Tls_optimization optimized_type
3730       = Target_x86_64<size>::optimize_tls_reloc(is_final, r_type);
3731   switch (r_type)
3732     {
3733     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
3734       if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
3735         {
3736           // If this code sequence is used in a non-executable section,
3737           // we will not optimize the R_X86_64_DTPOFF32/64 relocation,
3738           // on the assumption that it's being used by itself in a debug
3739           // section.  Therefore, in the unlikely event that the code
3740           // sequence appears in a non-executable section, we simply
3741           // leave it unoptimized.
3742           optimized_type = tls::TLSOPT_NONE;
3743         }
3744       if (optimized_type == tls::TLSOPT_TO_LE)
3745         {
3746           if (tls_segment == NULL)
3747             {
3748               gold_assert(parameters->errors()->error_count() > 0
3749                           || issue_undefined_symbol_error(gsym));
3750               return;
3751             }
3752           this->tls_gd_to_le(relinfo, relnum, tls_segment,
3753                              rela, r_type, value, view,
3754                              view_size);
3755           break;
3756         }
3757       else
3758         {
3759           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
3760                                    ? GOT_TYPE_TLS_OFFSET
3761                                    : GOT_TYPE_TLS_PAIR);
3762           unsigned int got_offset;
3763           if (gsym != NULL)
3764             {
3765               gold_assert(gsym->has_got_offset(got_type));
3766               got_offset = gsym->got_offset(got_type) - target->got_size();
3767             }
3768           else
3769             {
3770               unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3771               gold_assert(object->local_has_got_offset(r_sym, got_type));
3772               got_offset = (object->local_got_offset(r_sym, got_type)
3773                             - target->got_size());
3774             }
3775           if (optimized_type == tls::TLSOPT_TO_IE)
3776             {
3777               value = target->got_plt_section()->address() + got_offset;
3778               this->tls_gd_to_ie(relinfo, relnum, rela, r_type,
3779                                  value, view, address, view_size);
3780               break;
3781             }
3782           else if (optimized_type == tls::TLSOPT_NONE)
3783             {
3784               // Relocate the field with the offset of the pair of GOT
3785               // entries.
3786               value = target->got_plt_section()->address() + got_offset;
3787               Relocate_functions<size, false>::pcrela32(view, value, addend,
3788                                                         address);
3789               break;
3790             }
3791         }
3792       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3793                              _("unsupported reloc %u"), r_type);
3794       break;
3795
3796     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
3797     case elfcpp::R_X86_64_TLSDESC_CALL:
3798       if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
3799         {
3800           // See above comment for R_X86_64_TLSGD.
3801           optimized_type = tls::TLSOPT_NONE;
3802         }
3803       if (optimized_type == tls::TLSOPT_TO_LE)
3804         {
3805           if (tls_segment == NULL)
3806             {
3807               gold_assert(parameters->errors()->error_count() > 0
3808                           || issue_undefined_symbol_error(gsym));
3809               return;
3810             }
3811           this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
3812                                   rela, r_type, value, view,
3813                                   view_size);
3814           break;
3815         }
3816       else
3817         {
3818           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
3819                                    ? GOT_TYPE_TLS_OFFSET
3820                                    : GOT_TYPE_TLS_DESC);
3821           unsigned int got_offset = 0;
3822           if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC
3823               && optimized_type == tls::TLSOPT_NONE)
3824             {
3825               // We created GOT entries in the .got.tlsdesc portion of
3826               // the .got.plt section, but the offset stored in the
3827               // symbol is the offset within .got.tlsdesc.
3828               got_offset = (target->got_size()
3829                             + target->got_plt_section()->data_size());
3830             }
3831           if (gsym != NULL)
3832             {
3833               gold_assert(gsym->has_got_offset(got_type));
3834               got_offset += gsym->got_offset(got_type) - target->got_size();
3835             }
3836           else
3837             {
3838               unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3839               gold_assert(object->local_has_got_offset(r_sym, got_type));
3840               got_offset += (object->local_got_offset(r_sym, got_type)
3841                              - target->got_size());
3842             }
3843           if (optimized_type == tls::TLSOPT_TO_IE)
3844             {
3845               value = target->got_plt_section()->address() + got_offset;
3846               this->tls_desc_gd_to_ie(relinfo, relnum,
3847                                       rela, r_type, value, view, address,
3848                                       view_size);
3849               break;
3850             }
3851           else if (optimized_type == tls::TLSOPT_NONE)
3852             {
3853               if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
3854                 {
3855                   // Relocate the field with the offset of the pair of GOT
3856                   // entries.
3857                   value = target->got_plt_section()->address() + got_offset;
3858                   Relocate_functions<size, false>::pcrela32(view, value, addend,
3859                                                             address);
3860                 }
3861               break;
3862             }
3863         }
3864       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3865                              _("unsupported reloc %u"), r_type);
3866       break;
3867
3868     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
3869       if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
3870         {
3871           // See above comment for R_X86_64_TLSGD.
3872           optimized_type = tls::TLSOPT_NONE;
3873         }
3874       if (optimized_type == tls::TLSOPT_TO_LE)
3875         {
3876           if (tls_segment == NULL)
3877             {
3878               gold_assert(parameters->errors()->error_count() > 0
3879                           || issue_undefined_symbol_error(gsym));
3880               return;
3881             }
3882           this->tls_ld_to_le(relinfo, relnum, tls_segment, rela, r_type,
3883                              value, view, view_size);
3884           break;
3885         }
3886       else if (optimized_type == tls::TLSOPT_NONE)
3887         {
3888           // Relocate the field with the offset of the GOT entry for
3889           // the module index.
3890           unsigned int got_offset;
3891           got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
3892                         - target->got_size());
3893           value = target->got_plt_section()->address() + got_offset;
3894           Relocate_functions<size, false>::pcrela32(view, value, addend,
3895                                                     address);
3896           break;
3897         }
3898       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3899                              _("unsupported reloc %u"), r_type);
3900       break;
3901
3902     case elfcpp::R_X86_64_DTPOFF32:
3903       // This relocation type is used in debugging information.
3904       // In that case we need to not optimize the value.  If the
3905       // section is not executable, then we assume we should not
3906       // optimize this reloc.  See comments above for R_X86_64_TLSGD,
3907       // R_X86_64_GOTPC32_TLSDESC, R_X86_64_TLSDESC_CALL, and
3908       // R_X86_64_TLSLD.
3909       if (optimized_type == tls::TLSOPT_TO_LE && is_executable)
3910         {
3911           if (tls_segment == NULL)
3912             {
3913               gold_assert(parameters->errors()->error_count() > 0
3914                           || issue_undefined_symbol_error(gsym));
3915               return;
3916             }
3917           value -= tls_segment->memsz();
3918         }
3919       Relocate_functions<size, false>::rela32(view, value, addend);
3920       break;
3921
3922     case elfcpp::R_X86_64_DTPOFF64:
3923       // See R_X86_64_DTPOFF32, just above, for why we check for is_executable.
3924       if (optimized_type == tls::TLSOPT_TO_LE && is_executable)
3925         {
3926           if (tls_segment == NULL)
3927             {
3928               gold_assert(parameters->errors()->error_count() > 0
3929                           || issue_undefined_symbol_error(gsym));
3930               return;
3931             }
3932           value -= tls_segment->memsz();
3933         }
3934       Relocate_functions<size, false>::rela64(view, value, addend);
3935       break;
3936
3937     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
3938       if (gsym != NULL
3939           && gsym->is_undefined()
3940           && parameters->options().output_is_executable())
3941         {
3942           Target_x86_64<size>::Relocate::tls_ie_to_le(relinfo, relnum,
3943                                                       NULL, rela,
3944                                                       r_type, value, view,
3945                                                       view_size);
3946           break;
3947         }
3948       else if (optimized_type == tls::TLSOPT_TO_LE)
3949         {
3950           if (tls_segment == NULL)
3951             {
3952               gold_assert(parameters->errors()->error_count() > 0
3953                           || issue_undefined_symbol_error(gsym));
3954               return;
3955             }
3956           Target_x86_64<size>::Relocate::tls_ie_to_le(relinfo, relnum,
3957                                                       tls_segment, rela,
3958                                                       r_type, value, view,
3959                                                       view_size);
3960           break;
3961         }
3962       else if (optimized_type == tls::TLSOPT_NONE)
3963         {
3964           // Relocate the field with the offset of the GOT entry for
3965           // the tp-relative offset of the symbol.
3966           unsigned int got_offset;
3967           if (gsym != NULL)
3968             {
3969               gold_assert(gsym->has_got_offset(GOT_TYPE_TLS_OFFSET));
3970               got_offset = (gsym->got_offset(GOT_TYPE_TLS_OFFSET)
3971                             - target->got_size());
3972             }
3973           else
3974             {
3975               unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3976               gold_assert(object->local_has_got_offset(r_sym,
3977                                                        GOT_TYPE_TLS_OFFSET));
3978               got_offset = (object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET)
3979                             - target->got_size());
3980             }
3981           value = target->got_plt_section()->address() + got_offset;
3982           Relocate_functions<size, false>::pcrela32(view, value, addend,
3983                                                     address);
3984           break;
3985         }
3986       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3987                              _("unsupported reloc type %u"),
3988                              r_type);
3989       break;
3990
3991     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
3992       if (tls_segment == NULL)
3993         {
3994           gold_assert(parameters->errors()->error_count() > 0
3995                       || issue_undefined_symbol_error(gsym));
3996           return;
3997         }
3998       value -= tls_segment->memsz();
3999       Relocate_functions<size, false>::rela32(view, value, addend);
4000       break;
4001     }
4002 }
4003
4004 // Do a relocation in which we convert a TLS General-Dynamic to an
4005 // Initial-Exec.
4006
4007 template<int size>
4008 inline void
4009 Target_x86_64<size>::Relocate::tls_gd_to_ie(
4010     const Relocate_info<size, false>* relinfo,
4011     size_t relnum,
4012     const elfcpp::Rela<size, false>& rela,
4013     unsigned int,
4014     typename elfcpp::Elf_types<size>::Elf_Addr value,
4015     unsigned char* view,
4016     typename elfcpp::Elf_types<size>::Elf_Addr address,
4017     section_size_type view_size)
4018 {
4019   // For SIZE == 64:
4020   //    .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
4021   //    .word 0x6666; rex64; call __tls_get_addr
4022   //    ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
4023   // For SIZE == 32:
4024   //    leaq foo@tlsgd(%rip),%rdi;
4025   //    .word 0x6666; rex64; call __tls_get_addr
4026   //    ==> movl %fs:0,%eax; addq x@gottpoff(%rip),%rax
4027
4028   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
4029   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4030                  (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0));
4031
4032   if (size == 64)
4033     {
4034       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
4035                        -4);
4036       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4037                      (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
4038       memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0",
4039              16);
4040     }
4041   else
4042     {
4043       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
4044                        -3);
4045       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4046                      (memcmp(view - 3, "\x48\x8d\x3d", 3) == 0));
4047       memcpy(view - 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0",
4048              15);
4049     }
4050
4051   const elfcpp::Elf_Xword addend = rela.get_r_addend();
4052   Relocate_functions<size, false>::pcrela32(view + 8, value, addend - 8,
4053                                             address);
4054
4055   // The next reloc should be a PLT32 reloc against __tls_get_addr.
4056   // We can skip it.
4057   this->skip_call_tls_get_addr_ = true;
4058 }
4059
4060 // Do a relocation in which we convert a TLS General-Dynamic to a
4061 // Local-Exec.
4062
4063 template<int size>
4064 inline void
4065 Target_x86_64<size>::Relocate::tls_gd_to_le(
4066     const Relocate_info<size, false>* relinfo,
4067     size_t relnum,
4068     Output_segment* tls_segment,
4069     const elfcpp::Rela<size, false>& rela,
4070     unsigned int,
4071     typename elfcpp::Elf_types<size>::Elf_Addr value,
4072     unsigned char* view,
4073     section_size_type view_size)
4074 {
4075   // For SIZE == 64:
4076   //    .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
4077   //    .word 0x6666; rex64; call __tls_get_addr
4078   //    ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
4079   // For SIZE == 32:
4080   //    leaq foo@tlsgd(%rip),%rdi;
4081   //    .word 0x6666; rex64; call __tls_get_addr
4082   //    ==> movl %fs:0,%eax; leaq x@tpoff(%rax),%rax
4083
4084   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
4085   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4086                  (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0));
4087
4088   if (size == 64)
4089     {
4090       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
4091                        -4);
4092       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4093                      (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
4094       memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0",
4095              16);
4096     }
4097   else
4098     {
4099       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
4100                        -3);
4101       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4102                      (memcmp(view - 3, "\x48\x8d\x3d", 3) == 0));
4103
4104       memcpy(view - 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0",
4105              15);
4106     }
4107
4108   value -= tls_segment->memsz();
4109   Relocate_functions<size, false>::rela32(view + 8, value, 0);
4110
4111   // The next reloc should be a PLT32 reloc against __tls_get_addr.
4112   // We can skip it.
4113   this->skip_call_tls_get_addr_ = true;
4114 }
4115
4116 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
4117
4118 template<int size>
4119 inline void
4120 Target_x86_64<size>::Relocate::tls_desc_gd_to_ie(
4121     const Relocate_info<size, false>* relinfo,
4122     size_t relnum,
4123     const elfcpp::Rela<size, false>& rela,
4124     unsigned int r_type,
4125     typename elfcpp::Elf_types<size>::Elf_Addr value,
4126     unsigned char* view,
4127     typename elfcpp::Elf_types<size>::Elf_Addr address,
4128     section_size_type view_size)
4129 {
4130   if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
4131     {
4132       // leaq foo@tlsdesc(%rip), %rax
4133       // ==> movq foo@gottpoff(%rip), %rax
4134       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
4135       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
4136       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4137                      view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05);
4138       view[-2] = 0x8b;
4139       const elfcpp::Elf_Xword addend = rela.get_r_addend();
4140       Relocate_functions<size, false>::pcrela32(view, value, addend, address);
4141     }
4142   else
4143     {
4144       // call *foo@tlscall(%rax)
4145       // ==> nop; nop
4146       gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
4147       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
4148       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4149                      view[0] == 0xff && view[1] == 0x10);
4150       view[0] = 0x66;
4151       view[1] = 0x90;
4152     }
4153 }
4154
4155 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
4156
4157 template<int size>
4158 inline void
4159 Target_x86_64<size>::Relocate::tls_desc_gd_to_le(
4160     const Relocate_info<size, false>* relinfo,
4161     size_t relnum,
4162     Output_segment* tls_segment,
4163     const elfcpp::Rela<size, false>& rela,
4164     unsigned int r_type,
4165     typename elfcpp::Elf_types<size>::Elf_Addr value,
4166     unsigned char* view,
4167     section_size_type view_size)
4168 {
4169   if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
4170     {
4171       // leaq foo@tlsdesc(%rip), %rax
4172       // ==> movq foo@tpoff, %rax
4173       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
4174       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
4175       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4176                      view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05);
4177       view[-2] = 0xc7;
4178       view[-1] = 0xc0;
4179       value -= tls_segment->memsz();
4180       Relocate_functions<size, false>::rela32(view, value, 0);
4181     }
4182   else
4183     {
4184       // call *foo@tlscall(%rax)
4185       // ==> nop; nop
4186       gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
4187       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
4188       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4189                      view[0] == 0xff && view[1] == 0x10);
4190       view[0] = 0x66;
4191       view[1] = 0x90;
4192     }
4193 }
4194
4195 template<int size>
4196 inline void
4197 Target_x86_64<size>::Relocate::tls_ld_to_le(
4198     const Relocate_info<size, false>* relinfo,
4199     size_t relnum,
4200     Output_segment*,
4201     const elfcpp::Rela<size, false>& rela,
4202     unsigned int,
4203     typename elfcpp::Elf_types<size>::Elf_Addr,
4204     unsigned char* view,
4205     section_size_type view_size)
4206 {
4207   // leaq foo@tlsld(%rip),%rdi; call __tls_get_addr@plt;
4208   // For SIZE == 64:
4209   // ... leq foo@dtpoff(%rax),%reg
4210   // ==> .word 0x6666; .byte 0x66; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
4211   // For SIZE == 32:
4212   // ... leq foo@dtpoff(%rax),%reg
4213   // ==> nopl 0x0(%rax); movl %fs:0,%eax ... leaq x@tpoff(%rax),%rdx
4214
4215   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
4216   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 9);
4217
4218   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4219                  view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x3d);
4220
4221   tls::check_tls(relinfo, relnum, rela.get_r_offset(), view[4] == 0xe8);
4222
4223   if (size == 64)
4224     memcpy(view - 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12);
4225   else
4226     memcpy(view - 3, "\x0f\x1f\x40\x00\x64\x8b\x04\x25\0\0\0\0", 12);
4227
4228   // The next reloc should be a PLT32 reloc against __tls_get_addr.
4229   // We can skip it.
4230   this->skip_call_tls_get_addr_ = true;
4231 }
4232
4233 // Do a relocation in which we convert a TLS Initial-Exec to a
4234 // Local-Exec.
4235
4236 template<int size>
4237 inline void
4238 Target_x86_64<size>::Relocate::tls_ie_to_le(
4239     const Relocate_info<size, false>* relinfo,
4240     size_t relnum,
4241     Output_segment* tls_segment,
4242     const elfcpp::Rela<size, false>& rela,
4243     unsigned int,
4244     typename elfcpp::Elf_types<size>::Elf_Addr value,
4245     unsigned char* view,
4246     section_size_type view_size)
4247 {
4248   // We need to examine the opcodes to figure out which instruction we
4249   // are looking at.
4250
4251   // movq foo@gottpoff(%rip),%reg  ==>  movq $YY,%reg
4252   // addq foo@gottpoff(%rip),%reg  ==>  addq $YY,%reg
4253
4254   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
4255   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
4256
4257   unsigned char op1 = view[-3];
4258   unsigned char op2 = view[-2];
4259   unsigned char op3 = view[-1];
4260   unsigned char reg = op3 >> 3;
4261
4262   if (op2 == 0x8b)
4263     {
4264       // movq
4265       if (op1 == 0x4c)
4266         view[-3] = 0x49;
4267       else if (size == 32 && op1 == 0x44)
4268         view[-3] = 0x41;
4269       view[-2] = 0xc7;
4270       view[-1] = 0xc0 | reg;
4271     }
4272   else if (reg == 4)
4273     {
4274       // Special handling for %rsp.
4275       if (op1 == 0x4c)
4276         view[-3] = 0x49;
4277       else if (size == 32 && op1 == 0x44)
4278         view[-3] = 0x41;
4279       view[-2] = 0x81;
4280       view[-1] = 0xc0 | reg;
4281     }
4282   else
4283     {
4284       // addq
4285       if (op1 == 0x4c)
4286         view[-3] = 0x4d;
4287       else if (size == 32 && op1 == 0x44)
4288         view[-3] = 0x45;
4289       view[-2] = 0x8d;
4290       view[-1] = 0x80 | reg | (reg << 3);
4291     }
4292
4293   if (tls_segment != NULL)
4294     value -= tls_segment->memsz();
4295   Relocate_functions<size, false>::rela32(view, value, 0);
4296 }
4297
4298 // Relocate section data.
4299
4300 template<int size>
4301 void
4302 Target_x86_64<size>::relocate_section(
4303     const Relocate_info<size, false>* relinfo,
4304     unsigned int sh_type,
4305     const unsigned char* prelocs,
4306     size_t reloc_count,
4307     Output_section* output_section,
4308     bool needs_special_offset_handling,
4309     unsigned char* view,
4310     typename elfcpp::Elf_types<size>::Elf_Addr address,
4311     section_size_type view_size,
4312     const Reloc_symbol_changes* reloc_symbol_changes)
4313 {
4314   typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
4315       Classify_reloc;
4316
4317   gold_assert(sh_type == elfcpp::SHT_RELA);
4318
4319   gold::relocate_section<size, false, Target_x86_64<size>, Relocate,
4320                          gold::Default_comdat_behavior, Classify_reloc>(
4321     relinfo,
4322     this,
4323     prelocs,
4324     reloc_count,
4325     output_section,
4326     needs_special_offset_handling,
4327     view,
4328     address,
4329     view_size,
4330     reloc_symbol_changes);
4331 }
4332
4333 // Apply an incremental relocation.  Incremental relocations always refer
4334 // to global symbols.
4335
4336 template<int size>
4337 void
4338 Target_x86_64<size>::apply_relocation(
4339     const Relocate_info<size, false>* relinfo,
4340     typename elfcpp::Elf_types<size>::Elf_Addr r_offset,
4341     unsigned int r_type,
4342     typename elfcpp::Elf_types<size>::Elf_Swxword r_addend,
4343     const Symbol* gsym,
4344     unsigned char* view,
4345     typename elfcpp::Elf_types<size>::Elf_Addr address,
4346     section_size_type view_size)
4347 {
4348   gold::apply_relocation<size, false, Target_x86_64<size>,
4349                          typename Target_x86_64<size>::Relocate>(
4350     relinfo,
4351     this,
4352     r_offset,
4353     r_type,
4354     r_addend,
4355     gsym,
4356     view,
4357     address,
4358     view_size);
4359 }
4360
4361 // Scan the relocs during a relocatable link.
4362
4363 template<int size>
4364 void
4365 Target_x86_64<size>::scan_relocatable_relocs(
4366     Symbol_table* symtab,
4367     Layout* layout,
4368     Sized_relobj_file<size, false>* object,
4369     unsigned int data_shndx,
4370     unsigned int sh_type,
4371     const unsigned char* prelocs,
4372     size_t reloc_count,
4373     Output_section* output_section,
4374     bool needs_special_offset_handling,
4375     size_t local_symbol_count,
4376     const unsigned char* plocal_symbols,
4377     Relocatable_relocs* rr)
4378 {
4379   typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
4380       Classify_reloc;
4381   typedef gold::Default_scan_relocatable_relocs<Classify_reloc>
4382       Scan_relocatable_relocs;
4383
4384   gold_assert(sh_type == elfcpp::SHT_RELA);
4385
4386   gold::scan_relocatable_relocs<size, false, Scan_relocatable_relocs>(
4387     symtab,
4388     layout,
4389     object,
4390     data_shndx,
4391     prelocs,
4392     reloc_count,
4393     output_section,
4394     needs_special_offset_handling,
4395     local_symbol_count,
4396     plocal_symbols,
4397     rr);
4398 }
4399
4400 // Scan the relocs for --emit-relocs.
4401
4402 template<int size>
4403 void
4404 Target_x86_64<size>::emit_relocs_scan(
4405     Symbol_table* symtab,
4406     Layout* layout,
4407     Sized_relobj_file<size, false>* object,
4408     unsigned int data_shndx,
4409     unsigned int sh_type,
4410     const unsigned char* prelocs,
4411     size_t reloc_count,
4412     Output_section* output_section,
4413     bool needs_special_offset_handling,
4414     size_t local_symbol_count,
4415     const unsigned char* plocal_syms,
4416     Relocatable_relocs* rr)
4417 {
4418   typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
4419       Classify_reloc;
4420   typedef gold::Default_emit_relocs_strategy<Classify_reloc>
4421       Emit_relocs_strategy;
4422
4423   gold_assert(sh_type == elfcpp::SHT_RELA);
4424
4425   gold::scan_relocatable_relocs<size, false, Emit_relocs_strategy>(
4426     symtab,
4427     layout,
4428     object,
4429     data_shndx,
4430     prelocs,
4431     reloc_count,
4432     output_section,
4433     needs_special_offset_handling,
4434     local_symbol_count,
4435     plocal_syms,
4436     rr);
4437 }
4438
4439 // Relocate a section during a relocatable link.
4440
4441 template<int size>
4442 void
4443 Target_x86_64<size>::relocate_relocs(
4444     const Relocate_info<size, false>* relinfo,
4445     unsigned int sh_type,
4446     const unsigned char* prelocs,
4447     size_t reloc_count,
4448     Output_section* output_section,
4449     typename elfcpp::Elf_types<size>::Elf_Off offset_in_output_section,
4450     unsigned char* view,
4451     typename elfcpp::Elf_types<size>::Elf_Addr view_address,
4452     section_size_type view_size,
4453     unsigned char* reloc_view,
4454     section_size_type reloc_view_size)
4455 {
4456   typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
4457       Classify_reloc;
4458
4459   gold_assert(sh_type == elfcpp::SHT_RELA);
4460
4461   gold::relocate_relocs<size, false, Classify_reloc>(
4462     relinfo,
4463     prelocs,
4464     reloc_count,
4465     output_section,
4466     offset_in_output_section,
4467     view,
4468     view_address,
4469     view_size,
4470     reloc_view,
4471     reloc_view_size);
4472 }
4473
4474 // Return the value to use for a dynamic which requires special
4475 // treatment.  This is how we support equality comparisons of function
4476 // pointers across shared library boundaries, as described in the
4477 // processor specific ABI supplement.
4478
4479 template<int size>
4480 uint64_t
4481 Target_x86_64<size>::do_dynsym_value(const Symbol* gsym) const
4482 {
4483   gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
4484   return this->plt_address_for_global(gsym);
4485 }
4486
4487 // Return a string used to fill a code section with nops to take up
4488 // the specified length.
4489
4490 template<int size>
4491 std::string
4492 Target_x86_64<size>::do_code_fill(section_size_type length) const
4493 {
4494   if (length >= 16)
4495     {
4496       // Build a jmpq instruction to skip over the bytes.
4497       unsigned char jmp[5];
4498       jmp[0] = 0xe9;
4499       elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
4500       return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
4501               + std::string(length - 5, static_cast<char>(0x90)));
4502     }
4503
4504   // Nop sequences of various lengths.
4505   const char nop1[1] = { '\x90' };                 // nop
4506   const char nop2[2] = { '\x66', '\x90' };         // xchg %ax %ax
4507   const char nop3[3] = { '\x0f', '\x1f', '\x00' }; // nop (%rax)
4508   const char nop4[4] = { '\x0f', '\x1f', '\x40',   // nop 0(%rax)
4509                          '\x00'};
4510   const char nop5[5] = { '\x0f', '\x1f', '\x44',   // nop 0(%rax,%rax,1)
4511                          '\x00', '\x00' };
4512   const char nop6[6] = { '\x66', '\x0f', '\x1f',   // nopw 0(%rax,%rax,1)
4513                          '\x44', '\x00', '\x00' };
4514   const char nop7[7] = { '\x0f', '\x1f', '\x80',   // nopl 0L(%rax)
4515                          '\x00', '\x00', '\x00',
4516                          '\x00' };
4517   const char nop8[8] = { '\x0f', '\x1f', '\x84',   // nopl 0L(%rax,%rax,1)
4518                          '\x00', '\x00', '\x00',
4519                          '\x00', '\x00' };
4520   const char nop9[9] = { '\x66', '\x0f', '\x1f',   // nopw 0L(%rax,%rax,1)
4521                          '\x84', '\x00', '\x00',
4522                          '\x00', '\x00', '\x00' };
4523   const char nop10[10] = { '\x66', '\x2e', '\x0f', // nopw %cs:0L(%rax,%rax,1)
4524                            '\x1f', '\x84', '\x00',
4525                            '\x00', '\x00', '\x00',
4526                            '\x00' };
4527   const char nop11[11] = { '\x66', '\x66', '\x2e', // data16
4528                            '\x0f', '\x1f', '\x84', // nopw %cs:0L(%rax,%rax,1)
4529                            '\x00', '\x00', '\x00',
4530                            '\x00', '\x00' };
4531   const char nop12[12] = { '\x66', '\x66', '\x66', // data16; data16
4532                            '\x2e', '\x0f', '\x1f', // nopw %cs:0L(%rax,%rax,1)
4533                            '\x84', '\x00', '\x00',
4534                            '\x00', '\x00', '\x00' };
4535   const char nop13[13] = { '\x66', '\x66', '\x66', // data16; data16; data16
4536                            '\x66', '\x2e', '\x0f', // nopw %cs:0L(%rax,%rax,1)
4537                            '\x1f', '\x84', '\x00',
4538                            '\x00', '\x00', '\x00',
4539                            '\x00' };
4540   const char nop14[14] = { '\x66', '\x66', '\x66', // data16; data16; data16
4541                            '\x66', '\x66', '\x2e', // data16
4542                            '\x0f', '\x1f', '\x84', // nopw %cs:0L(%rax,%rax,1)
4543                            '\x00', '\x00', '\x00',
4544                            '\x00', '\x00' };
4545   const char nop15[15] = { '\x66', '\x66', '\x66', // data16; data16; data16
4546                            '\x66', '\x66', '\x66', // data16; data16
4547                            '\x2e', '\x0f', '\x1f', // nopw %cs:0L(%rax,%rax,1)
4548                            '\x84', '\x00', '\x00',
4549                            '\x00', '\x00', '\x00' };
4550
4551   const char* nops[16] = {
4552     NULL,
4553     nop1, nop2, nop3, nop4, nop5, nop6, nop7,
4554     nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
4555   };
4556
4557   return std::string(nops[length], length);
4558 }
4559
4560 // Return the addend to use for a target specific relocation.  The
4561 // only target specific relocation is R_X86_64_TLSDESC for a local
4562 // symbol.  We want to set the addend is the offset of the local
4563 // symbol in the TLS segment.
4564
4565 template<int size>
4566 uint64_t
4567 Target_x86_64<size>::do_reloc_addend(void* arg, unsigned int r_type,
4568                                      uint64_t) const
4569 {
4570   gold_assert(r_type == elfcpp::R_X86_64_TLSDESC);
4571   uintptr_t intarg = reinterpret_cast<uintptr_t>(arg);
4572   gold_assert(intarg < this->tlsdesc_reloc_info_.size());
4573   const Tlsdesc_info& ti(this->tlsdesc_reloc_info_[intarg]);
4574   const Symbol_value<size>* psymval = ti.object->local_symbol(ti.r_sym);
4575   gold_assert(psymval->is_tls_symbol());
4576   // The value of a TLS symbol is the offset in the TLS segment.
4577   return psymval->value(ti.object, 0);
4578 }
4579
4580 // Return the value to use for the base of a DW_EH_PE_datarel offset
4581 // in an FDE.  Solaris and SVR4 use DW_EH_PE_datarel because their
4582 // assembler can not write out the difference between two labels in
4583 // different sections, so instead of using a pc-relative value they
4584 // use an offset from the GOT.
4585
4586 template<int size>
4587 uint64_t
4588 Target_x86_64<size>::do_ehframe_datarel_base() const
4589 {
4590   gold_assert(this->global_offset_table_ != NULL);
4591   Symbol* sym = this->global_offset_table_;
4592   Sized_symbol<size>* ssym = static_cast<Sized_symbol<size>*>(sym);
4593   return ssym->value();
4594 }
4595
4596 // FNOFFSET in section SHNDX in OBJECT is the start of a function
4597 // compiled with -fsplit-stack.  The function calls non-split-stack
4598 // code.  We have to change the function so that it always ensures
4599 // that it has enough stack space to run some random function.
4600
4601 static const unsigned char cmp_insn_32[] = { 0x64, 0x3b, 0x24, 0x25 };
4602 static const unsigned char lea_r10_insn_32[] = { 0x44, 0x8d, 0x94, 0x24 };
4603 static const unsigned char lea_r11_insn_32[] = { 0x44, 0x8d, 0x9c, 0x24 };
4604
4605 static const unsigned char cmp_insn_64[] = { 0x64, 0x48, 0x3b, 0x24, 0x25 };
4606 static const unsigned char lea_r10_insn_64[] = { 0x4c, 0x8d, 0x94, 0x24 };
4607 static const unsigned char lea_r11_insn_64[] = { 0x4c, 0x8d, 0x9c, 0x24 };
4608
4609 template<int size>
4610 void
4611 Target_x86_64<size>::do_calls_non_split(Relobj* object, unsigned int shndx,
4612                                         section_offset_type fnoffset,
4613                                         section_size_type fnsize,
4614                                         const unsigned char*,
4615                                         size_t,
4616                                         unsigned char* view,
4617                                         section_size_type view_size,
4618                                         std::string* from,
4619                                         std::string* to) const
4620 {
4621   const char* const cmp_insn = reinterpret_cast<const char*>
4622       (size == 32 ? cmp_insn_32 : cmp_insn_64);
4623   const char* const lea_r10_insn = reinterpret_cast<const char*>
4624       (size == 32 ? lea_r10_insn_32 : lea_r10_insn_64);
4625   const char* const lea_r11_insn = reinterpret_cast<const char*>
4626       (size == 32 ? lea_r11_insn_32 : lea_r11_insn_64);
4627
4628   const size_t cmp_insn_len =
4629       (size == 32 ? sizeof(cmp_insn_32) : sizeof(cmp_insn_64));
4630   const size_t lea_r10_insn_len =
4631       (size == 32 ? sizeof(lea_r10_insn_32) : sizeof(lea_r10_insn_64));
4632   const size_t lea_r11_insn_len =
4633       (size == 32 ? sizeof(lea_r11_insn_32) : sizeof(lea_r11_insn_64));
4634   const size_t nop_len = (size == 32 ? 7 : 8);
4635
4636   // The function starts with a comparison of the stack pointer and a
4637   // field in the TCB.  This is followed by a jump.
4638
4639   // cmp %fs:NN,%rsp
4640   if (this->match_view(view, view_size, fnoffset, cmp_insn, cmp_insn_len)
4641       && fnsize > nop_len + 1)
4642     {
4643       // We will call __morestack if the carry flag is set after this
4644       // comparison.  We turn the comparison into an stc instruction
4645       // and some nops.
4646       view[fnoffset] = '\xf9';
4647       this->set_view_to_nop(view, view_size, fnoffset + 1, nop_len);
4648     }
4649   // lea NN(%rsp),%r10
4650   // lea NN(%rsp),%r11
4651   else if ((this->match_view(view, view_size, fnoffset,
4652                              lea_r10_insn, lea_r10_insn_len)
4653             || this->match_view(view, view_size, fnoffset,
4654                                 lea_r11_insn, lea_r11_insn_len))
4655            && fnsize > 8)
4656     {
4657       // This is loading an offset from the stack pointer for a
4658       // comparison.  The offset is negative, so we decrease the
4659       // offset by the amount of space we need for the stack.  This
4660       // means we will avoid calling __morestack if there happens to
4661       // be plenty of space on the stack already.
4662       unsigned char* pval = view + fnoffset + 4;
4663       uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
4664       val -= parameters->options().split_stack_adjust_size();
4665       elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
4666     }
4667   else
4668     {
4669       if (!object->has_no_split_stack())
4670         object->error(_("failed to match split-stack sequence at "
4671                         "section %u offset %0zx"),
4672                       shndx, static_cast<size_t>(fnoffset));
4673       return;
4674     }
4675
4676   // We have to change the function so that it calls
4677   // __morestack_non_split instead of __morestack.  The former will
4678   // allocate additional stack space.
4679   *from = "__morestack";
4680   *to = "__morestack_non_split";
4681 }
4682
4683 // The selector for x86_64 object files.  Note this is never instantiated
4684 // directly.  It's only used in Target_selector_x86_64_nacl, below.
4685
4686 template<int size>
4687 class Target_selector_x86_64 : public Target_selector_freebsd
4688 {
4689 public:
4690   Target_selector_x86_64()
4691     : Target_selector_freebsd(elfcpp::EM_X86_64, size, false,
4692                               (size == 64
4693                                ? "elf64-x86-64" : "elf32-x86-64"),
4694                               (size == 64
4695                                ? "elf64-x86-64-freebsd"
4696                                : "elf32-x86-64-freebsd"),
4697                               (size == 64 ? "elf_x86_64" : "elf32_x86_64"))
4698   { }
4699
4700   Target*
4701   do_instantiate_target()
4702   { return new Target_x86_64<size>(); }
4703
4704 };
4705
4706 // NaCl variant.  It uses different PLT contents.
4707
4708 template<int size>
4709 class Output_data_plt_x86_64_nacl : public Output_data_plt_x86_64<size>
4710 {
4711  public:
4712   Output_data_plt_x86_64_nacl(Layout* layout,
4713                               Output_data_got<64, false>* got,
4714                               Output_data_got_plt_x86_64* got_plt,
4715                               Output_data_space* got_irelative)
4716     : Output_data_plt_x86_64<size>(layout, plt_entry_size,
4717                                    got, got_plt, got_irelative)
4718   { }
4719
4720   Output_data_plt_x86_64_nacl(Layout* layout,
4721                               Output_data_got<64, false>* got,
4722                               Output_data_got_plt_x86_64* got_plt,
4723                               Output_data_space* got_irelative,
4724                               unsigned int plt_count)
4725     : Output_data_plt_x86_64<size>(layout, plt_entry_size,
4726                                    got, got_plt, got_irelative,
4727                                    plt_count)
4728   { }
4729
4730  protected:
4731   virtual unsigned int
4732   do_get_plt_entry_size() const
4733   { return plt_entry_size; }
4734
4735   virtual void
4736   do_add_eh_frame(Layout* layout)
4737   {
4738     layout->add_eh_frame_for_plt(this,
4739                                  this->plt_eh_frame_cie,
4740                                  this->plt_eh_frame_cie_size,
4741                                  plt_eh_frame_fde,
4742                                  plt_eh_frame_fde_size);
4743   }
4744
4745   virtual void
4746   do_fill_first_plt_entry(unsigned char* pov,
4747                           typename elfcpp::Elf_types<size>::Elf_Addr got_addr,
4748                           typename elfcpp::Elf_types<size>::Elf_Addr plt_addr);
4749
4750   virtual unsigned int
4751   do_fill_plt_entry(unsigned char* pov,
4752                     typename elfcpp::Elf_types<size>::Elf_Addr got_address,
4753                     typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
4754                     unsigned int got_offset,
4755                     unsigned int plt_offset,
4756                     unsigned int plt_index);
4757
4758   virtual void
4759   do_fill_tlsdesc_entry(unsigned char* pov,
4760                         typename elfcpp::Elf_types<size>::Elf_Addr got_address,
4761                         typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
4762                         typename elfcpp::Elf_types<size>::Elf_Addr got_base,
4763                         unsigned int tlsdesc_got_offset,
4764                         unsigned int plt_offset);
4765
4766  private:
4767   // The size of an entry in the PLT.
4768   static const int plt_entry_size = 64;
4769
4770   // The first entry in the PLT.
4771   static const unsigned char first_plt_entry[plt_entry_size];
4772
4773   // Other entries in the PLT for an executable.
4774   static const unsigned char plt_entry[plt_entry_size];
4775
4776   // The reserved TLSDESC entry in the PLT for an executable.
4777   static const unsigned char tlsdesc_plt_entry[plt_entry_size];
4778
4779   // The .eh_frame unwind information for the PLT.
4780   static const int plt_eh_frame_fde_size = 32;
4781   static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
4782 };
4783
4784 template<int size>
4785 class Target_x86_64_nacl : public Target_x86_64<size>
4786 {
4787  public:
4788   Target_x86_64_nacl()
4789     : Target_x86_64<size>(&x86_64_nacl_info)
4790   { }
4791
4792   virtual Output_data_plt_x86_64<size>*
4793   do_make_data_plt(Layout* layout,
4794                    Output_data_got<64, false>* got,
4795                    Output_data_got_plt_x86_64* got_plt,
4796                    Output_data_space* got_irelative)
4797   {
4798     return new Output_data_plt_x86_64_nacl<size>(layout, got, got_plt,
4799                                                  got_irelative);
4800   }
4801
4802   virtual Output_data_plt_x86_64<size>*
4803   do_make_data_plt(Layout* layout,
4804                    Output_data_got<64, false>* got,
4805                    Output_data_got_plt_x86_64* got_plt,
4806                    Output_data_space* got_irelative,
4807                    unsigned int plt_count)
4808   {
4809     return new Output_data_plt_x86_64_nacl<size>(layout, got, got_plt,
4810                                                  got_irelative,
4811                                                  plt_count);
4812   }
4813
4814   virtual std::string
4815   do_code_fill(section_size_type length) const;
4816
4817  private:
4818   static const Target::Target_info x86_64_nacl_info;
4819 };
4820
4821 template<>
4822 const Target::Target_info Target_x86_64_nacl<64>::x86_64_nacl_info =
4823 {
4824   64,                   // size
4825   false,                // is_big_endian
4826   elfcpp::EM_X86_64,    // machine_code
4827   false,                // has_make_symbol
4828   false,                // has_resolve
4829   true,                 // has_code_fill
4830   true,                 // is_default_stack_executable
4831   true,                 // can_icf_inline_merge_sections
4832   '\0',                 // wrap_char
4833   "/lib64/ld-nacl-x86-64.so.1", // dynamic_linker
4834   0x20000,              // default_text_segment_address
4835   0x10000,              // abi_pagesize (overridable by -z max-page-size)
4836   0x10000,              // common_pagesize (overridable by -z common-page-size)
4837   true,                 // isolate_execinstr
4838   0x10000000,           // rosegment_gap
4839   elfcpp::SHN_UNDEF,    // small_common_shndx
4840   elfcpp::SHN_X86_64_LCOMMON,   // large_common_shndx
4841   0,                    // small_common_section_flags
4842   elfcpp::SHF_X86_64_LARGE,     // large_common_section_flags
4843   NULL,                 // attributes_section
4844   NULL,                 // attributes_vendor
4845   "_start",             // entry_symbol_name
4846   32,                   // hash_entry_size
4847 };
4848
4849 template<>
4850 const Target::Target_info Target_x86_64_nacl<32>::x86_64_nacl_info =
4851 {
4852   32,                   // size
4853   false,                // is_big_endian
4854   elfcpp::EM_X86_64,    // machine_code
4855   false,                // has_make_symbol
4856   false,                // has_resolve
4857   true,                 // has_code_fill
4858   true,                 // is_default_stack_executable
4859   true,                 // can_icf_inline_merge_sections
4860   '\0',                 // wrap_char
4861   "/lib/ld-nacl-x86-64.so.1", // dynamic_linker
4862   0x20000,              // default_text_segment_address
4863   0x10000,              // abi_pagesize (overridable by -z max-page-size)
4864   0x10000,              // common_pagesize (overridable by -z common-page-size)
4865   true,                 // isolate_execinstr
4866   0x10000000,           // rosegment_gap
4867   elfcpp::SHN_UNDEF,    // small_common_shndx
4868   elfcpp::SHN_X86_64_LCOMMON,   // large_common_shndx
4869   0,                    // small_common_section_flags
4870   elfcpp::SHF_X86_64_LARGE,     // large_common_section_flags
4871   NULL,                 // attributes_section
4872   NULL,                 // attributes_vendor
4873   "_start",             // entry_symbol_name
4874   32,                   // hash_entry_size
4875 };
4876
4877 #define NACLMASK        0xe0            // 32-byte alignment mask.
4878
4879 // The first entry in the PLT.
4880
4881 template<int size>
4882 const unsigned char
4883 Output_data_plt_x86_64_nacl<size>::first_plt_entry[plt_entry_size] =
4884 {
4885   0xff, 0x35,                         // pushq contents of memory address
4886   0, 0, 0, 0,                         // replaced with address of .got + 8
4887   0x4c, 0x8b, 0x1d,                   // mov GOT+16(%rip), %r11
4888   0, 0, 0, 0,                         // replaced with address of .got + 16
4889   0x41, 0x83, 0xe3, NACLMASK,         // and $-32, %r11d
4890   0x4d, 0x01, 0xfb,                   // add %r15, %r11
4891   0x41, 0xff, 0xe3,                   // jmpq *%r11
4892
4893   // 9-byte nop sequence to pad out to the next 32-byte boundary.
4894   0x66, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw 0x0(%rax,%rax,1)
4895
4896   // 32 bytes of nop to pad out to the standard size
4897   0x66, 0x66, 0x66, 0x66, 0x66, 0x66,    // excess data32 prefixes
4898   0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4899   0x66, 0x66, 0x66, 0x66, 0x66, 0x66,    // excess data32 prefixes
4900   0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4901   0x66,                                  // excess data32 prefix
4902   0x90                                   // nop
4903 };
4904
4905 template<int size>
4906 void
4907 Output_data_plt_x86_64_nacl<size>::do_fill_first_plt_entry(
4908     unsigned char* pov,
4909     typename elfcpp::Elf_types<size>::Elf_Addr got_address,
4910     typename elfcpp::Elf_types<size>::Elf_Addr plt_address)
4911 {
4912   memcpy(pov, first_plt_entry, plt_entry_size);
4913   elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
4914                                               (got_address + 8
4915                                                - (plt_address + 2 + 4)));
4916   elfcpp::Swap_unaligned<32, false>::writeval(pov + 9,
4917                                               (got_address + 16
4918                                                - (plt_address + 9 + 4)));
4919 }
4920
4921 // Subsequent entries in the PLT.
4922
4923 template<int size>
4924 const unsigned char
4925 Output_data_plt_x86_64_nacl<size>::plt_entry[plt_entry_size] =
4926 {
4927   0x4c, 0x8b, 0x1d,              // mov name@GOTPCREL(%rip),%r11
4928   0, 0, 0, 0,                    // replaced with address of symbol in .got
4929   0x41, 0x83, 0xe3, NACLMASK,    // and $-32, %r11d
4930   0x4d, 0x01, 0xfb,              // add %r15, %r11
4931   0x41, 0xff, 0xe3,              // jmpq *%r11
4932
4933   // 15-byte nop sequence to pad out to the next 32-byte boundary.
4934   0x66, 0x66, 0x66, 0x66, 0x66, 0x66,    // excess data32 prefixes
4935   0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4936
4937   // Lazy GOT entries point here (32-byte aligned).
4938   0x68,                       // pushq immediate
4939   0, 0, 0, 0,                 // replaced with index into relocation table
4940   0xe9,                       // jmp relative
4941   0, 0, 0, 0,                 // replaced with offset to start of .plt0
4942
4943   // 22 bytes of nop to pad out to the standard size.
4944   0x66, 0x66, 0x66, 0x66, 0x66, 0x66,    // excess data32 prefixes
4945   0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4946   0x0f, 0x1f, 0x80, 0, 0, 0, 0,          // nopl 0x0(%rax)
4947 };
4948
4949 template<int size>
4950 unsigned int
4951 Output_data_plt_x86_64_nacl<size>::do_fill_plt_entry(
4952     unsigned char* pov,
4953     typename elfcpp::Elf_types<size>::Elf_Addr got_address,
4954     typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
4955     unsigned int got_offset,
4956     unsigned int plt_offset,
4957     unsigned int plt_index)
4958 {
4959   memcpy(pov, plt_entry, plt_entry_size);
4960   elfcpp::Swap_unaligned<32, false>::writeval(pov + 3,
4961                                               (got_address + got_offset
4962                                                - (plt_address + plt_offset
4963                                                   + 3 + 4)));
4964
4965   elfcpp::Swap_unaligned<32, false>::writeval(pov + 33, plt_index);
4966   elfcpp::Swap_unaligned<32, false>::writeval(pov + 38,
4967                                               - (plt_offset + 38 + 4));
4968
4969   return 32;
4970 }
4971
4972 // The reserved TLSDESC entry in the PLT.
4973
4974 template<int size>
4975 const unsigned char
4976 Output_data_plt_x86_64_nacl<size>::tlsdesc_plt_entry[plt_entry_size] =
4977 {
4978   0xff, 0x35,                   // pushq x(%rip)
4979   0, 0, 0, 0,   // replaced with address of linkmap GOT entry (at PLTGOT + 8)
4980   0x4c, 0x8b, 0x1d,             // mov y(%rip),%r11
4981   0, 0, 0, 0,   // replaced with offset of reserved TLSDESC_GOT entry
4982   0x41, 0x83, 0xe3, NACLMASK,   // and $-32, %r11d
4983   0x4d, 0x01, 0xfb,             // add %r15, %r11
4984   0x41, 0xff, 0xe3,             // jmpq *%r11
4985
4986   // 41 bytes of nop to pad out to the standard size.
4987   0x66, 0x66, 0x66, 0x66, 0x66, 0x66,    // excess data32 prefixes
4988   0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4989   0x66, 0x66, 0x66, 0x66, 0x66, 0x66,    // excess data32 prefixes
4990   0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4991   0x66, 0x66,                            // excess data32 prefixes
4992   0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4993 };
4994
4995 template<int size>
4996 void
4997 Output_data_plt_x86_64_nacl<size>::do_fill_tlsdesc_entry(
4998     unsigned char* pov,
4999     typename elfcpp::Elf_types<size>::Elf_Addr got_address,
5000     typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
5001     typename elfcpp::Elf_types<size>::Elf_Addr got_base,
5002     unsigned int tlsdesc_got_offset,
5003     unsigned int plt_offset)
5004 {
5005   memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
5006   elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
5007                                               (got_address + 8
5008                                                - (plt_address + plt_offset
5009                                                   + 2 + 4)));
5010   elfcpp::Swap_unaligned<32, false>::writeval(pov + 9,
5011                                               (got_base
5012                                                + tlsdesc_got_offset
5013                                                - (plt_address + plt_offset
5014                                                   + 9 + 4)));
5015 }
5016
5017 // The .eh_frame unwind information for the PLT.
5018
5019 template<int size>
5020 const unsigned char
5021 Output_data_plt_x86_64_nacl<size>::plt_eh_frame_fde[plt_eh_frame_fde_size] =
5022 {
5023   0, 0, 0, 0,                           // Replaced with offset to .plt.
5024   0, 0, 0, 0,                           // Replaced with size of .plt.
5025   0,                                    // Augmentation size.
5026   elfcpp::DW_CFA_def_cfa_offset, 16,    // DW_CFA_def_cfa_offset: 16.
5027   elfcpp::DW_CFA_advance_loc + 6,       // Advance 6 to __PLT__ + 6.
5028   elfcpp::DW_CFA_def_cfa_offset, 24,    // DW_CFA_def_cfa_offset: 24.
5029   elfcpp::DW_CFA_advance_loc + 58,      // Advance 58 to __PLT__ + 64.
5030   elfcpp::DW_CFA_def_cfa_expression,    // DW_CFA_def_cfa_expression.
5031   13,                                   // Block length.
5032   elfcpp::DW_OP_breg7, 8,               // Push %rsp + 8.
5033   elfcpp::DW_OP_breg16, 0,              // Push %rip.
5034   elfcpp::DW_OP_const1u, 63,            // Push 0x3f.
5035   elfcpp::DW_OP_and,                    // & (%rip & 0x3f).
5036   elfcpp::DW_OP_const1u, 37,            // Push 0x25.
5037   elfcpp::DW_OP_ge,                     // >= ((%rip & 0x3f) >= 0x25)
5038   elfcpp::DW_OP_lit3,                   // Push 3.
5039   elfcpp::DW_OP_shl,                    // << (((%rip & 0x3f) >= 0x25) << 3)
5040   elfcpp::DW_OP_plus,                   // + ((((%rip&0x3f)>=0x25)<<3)+%rsp+8
5041   elfcpp::DW_CFA_nop,                   // Align to 32 bytes.
5042   elfcpp::DW_CFA_nop
5043 };
5044
5045 // Return a string used to fill a code section with nops.
5046 // For NaCl, long NOPs are only valid if they do not cross
5047 // bundle alignment boundaries, so keep it simple with one-byte NOPs.
5048 template<int size>
5049 std::string
5050 Target_x86_64_nacl<size>::do_code_fill(section_size_type length) const
5051 {
5052   return std::string(length, static_cast<char>(0x90));
5053 }
5054
5055 // The selector for x86_64-nacl object files.
5056
5057 template<int size>
5058 class Target_selector_x86_64_nacl
5059   : public Target_selector_nacl<Target_selector_x86_64<size>,
5060                                 Target_x86_64_nacl<size> >
5061 {
5062  public:
5063   Target_selector_x86_64_nacl()
5064     : Target_selector_nacl<Target_selector_x86_64<size>,
5065                            Target_x86_64_nacl<size> >("x86-64",
5066                                                       size == 64
5067                                                       ? "elf64-x86-64-nacl"
5068                                                       : "elf32-x86-64-nacl",
5069                                                       size == 64
5070                                                       ? "elf_x86_64_nacl"
5071                                                       : "elf32_x86_64_nacl")
5072   { }
5073 };
5074
5075 Target_selector_x86_64_nacl<64> target_selector_x86_64;
5076 Target_selector_x86_64_nacl<32> target_selector_x32;
5077
5078 } // End anonymous namespace.