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                  Output_segment* tls_segment,
 820                  const elfcpp::Rela<size, false>&, unsigned int r_type,
 821                  typename elfcpp::Elf_types<size>::Elf_Addr value,
 822                  unsigned char* view,
 823                  typename elfcpp::Elf_types<size>::Elf_Addr,
 824                  section_size_type view_size);
 825
 826     // Do a TLS General-Dynamic to Local-Exec transition.
 827     inline void
 828     tls_gd_to_le(const Relocate_info<size, false>*, size_t relnum,
 829                  Output_segment* tls_segment,
 830                  const elfcpp::Rela<size, false>&, unsigned int r_type,
 831                  typename elfcpp::Elf_types<size>::Elf_Addr value,
 832                  unsigned char* view,
 833                  section_size_type view_size);
 834
 835     // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
 836     inline void
 837     tls_desc_gd_to_ie(const Relocate_info<size, false>*, size_t relnum,
 838                       Output_segment* tls_segment,
 839                       const elfcpp::Rela<size, false>&, unsigned int r_type,
 840                       typename elfcpp::Elf_types<size>::Elf_Addr value,
 841                       unsigned char* view,
 842                       typename elfcpp::Elf_types<size>::Elf_Addr,
 843                       section_size_type view_size);
 844
 845     // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
 846     inline void
 847     tls_desc_gd_to_le(const Relocate_info<size, false>*, size_t relnum,
 848                       Output_segment* tls_segment,
 849                       const elfcpp::Rela<size, false>&, unsigned int r_type,
 850                       typename elfcpp::Elf_types<size>::Elf_Addr value,
 851                       unsigned char* view,
 852                       section_size_type view_size);
 853
 854     // Do a TLS Local-Dynamic to Local-Exec transition.
 855     inline void
 856     tls_ld_to_le(const Relocate_info<size, false>*, size_t relnum,
 857                  Output_segment* tls_segment,
 858                  const elfcpp::Rela<size, false>&, unsigned int r_type,
 859                  typename elfcpp::Elf_types<size>::Elf_Addr value,
 860                  unsigned char* view,
 861                  section_size_type view_size);
 862
 863     // Do a TLS Initial-Exec to Local-Exec transition.
 864     static inline void
 865     tls_ie_to_le(const Relocate_info<size, false>*, size_t relnum,
 866                  Output_segment* tls_segment,
 867                  const elfcpp::Rela<size, false>&, unsigned int r_type,
 868                  typename elfcpp::Elf_types<size>::Elf_Addr value,
 869                  unsigned char* view,
 870                  section_size_type view_size);
 871
 872     // This is set if we should skip the next reloc, which should be a
 873     // PLT32 reloc against ___tls_get_addr.
 874     bool skip_call_tls_get_addr_;
 875   };
 876
 877   // Check if relocation against this symbol is a candidate for
 878   // conversion from
 879   // mov foo@GOTPCREL(%rip), %reg
 880   // to lea foo(%rip), %reg.
 881   static bool
 882   can_convert_mov_to_lea(const Symbol* gsym)
 883   {
 884     gold_assert(gsym != NULL);
 885     return (gsym->type() != elfcpp::STT_GNU_IFUNC
 886             && !gsym->is_undefined ()
 887             && !gsym->is_from_dynobj()
 888             && !gsym->is_preemptible()
 889             && (!parameters->options().shared()
 890                 || (gsym->visibility() != elfcpp::STV_DEFAULT
 891                     && gsym->visibility() != elfcpp::STV_PROTECTED)
 892                 || parameters->options().Bsymbolic())
 893             && strcmp(gsym->name(), "_DYNAMIC") != 0);
 894   }
 895
 896   // Adjust TLS relocation type based on the options and whether this
 897   // is a local symbol.
 898   static tls::Tls_optimization
 899   optimize_tls_reloc(bool is_final, int r_type);
 900
 901   // Get the GOT section, creating it if necessary.
 902   Output_data_got<64, false>*
 903   got_section(Symbol_table*, Layout*);
 904
 905   // Get the GOT PLT section.
 906   Output_data_got_plt_x86_64*
 907   got_plt_section() const
 908   {
 909     gold_assert(this->got_plt_ != NULL);
 910     return this->got_plt_;
 911   }
 912
 913   // Get the GOT section for TLSDESC entries.
 914   Output_data_got<64, false>*
 915   got_tlsdesc_section() const
 916   {
 917     gold_assert(this->got_tlsdesc_ != NULL);
 918     return this->got_tlsdesc_;
 919   }
 920
 921   // Create the PLT section.
 922   void
 923   make_plt_section(Symbol_table* symtab, Layout* layout);
 924
 925   // Create a PLT entry for a global symbol.
 926   void
 927   make_plt_entry(Symbol_table*, Layout*, Symbol*);
 928
 929   // Create a PLT entry for a local STT_GNU_IFUNC symbol.
 930   void
 931   make_local_ifunc_plt_entry(Symbol_table*, Layout*,
 932                              Sized_relobj_file<size, false>* relobj,
 933                              unsigned int local_sym_index);
 934
 935   // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
 936   void
 937   define_tls_base_symbol(Symbol_table*, Layout*);
 938
 939   // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
 940   void
 941   reserve_tlsdesc_entries(Symbol_table* symtab, Layout* layout);
 942
 943   // Create a GOT entry for the TLS module index.
 944   unsigned int
 945   got_mod_index_entry(Symbol_table* symtab, Layout* layout,
 946                       Sized_relobj_file<size, false>* object);
 947
 948   // Get the PLT section.
 949   Output_data_plt_x86_64<size>*
 950   plt_section() const
 951   {
 952     gold_assert(this->plt_ != NULL);
 953     return this->plt_;
 954   }
 955
 956   // Get the dynamic reloc section, creating it if necessary.
 957   Reloc_section*
 958   rela_dyn_section(Layout*);
 959
 960   // Get the section to use for TLSDESC relocations.
 961   Reloc_section*
 962   rela_tlsdesc_section(Layout*) const;
 963
 964   // Get the section to use for IRELATIVE relocations.
 965   Reloc_section*
 966   rela_irelative_section(Layout*);
 967
 968   // Add a potential copy relocation.
 969   void
 970   copy_reloc(Symbol_table* symtab, Layout* layout,
 971              Sized_relobj_file<size, false>* object,
 972              unsigned int shndx, Output_section* output_section,
 973              Symbol* sym, const elfcpp::Rela<size, false>& reloc)
 974   {
 975     unsigned int r_type = elfcpp::elf_r_type<size>(reloc.get_r_info());
 976     this->copy_relocs_.copy_reloc(symtab, layout,
 977                                   symtab->get_sized_symbol<size>(sym),
 978                                   object, shndx, output_section,
 979                                   r_type, reloc.get_r_offset(),
 980                                   reloc.get_r_addend(),
 981                                   this->rela_dyn_section(layout));
 982   }
 983
 984   // Information about this specific target which we pass to the
 985   // general Target structure.
 986   static const Target::Target_info x86_64_info;
 987
 988   // The types of GOT entries needed for this platform.
 989   // These values are exposed to the ABI in an incremental link.
 990   // Do not renumber existing values without changing the version
 991   // number of the .gnu_incremental_inputs section.
 992   enum Got_type
 993   {
 994     GOT_TYPE_STANDARD = 0,      // GOT entry for a regular symbol
 995     GOT_TYPE_TLS_OFFSET = 1,    // GOT entry for TLS offset
 996     GOT_TYPE_TLS_PAIR = 2,      // GOT entry for TLS module/offset pair
 997     GOT_TYPE_TLS_DESC = 3       // GOT entry for TLS_DESC pair
 998   };
 999
1000   // This type is used as the argument to the target specific
1001   // relocation routines.  The only target specific reloc is
1002   // R_X86_64_TLSDESC against a local symbol.
1003   struct Tlsdesc_info
1004   {
1005     Tlsdesc_info(Sized_relobj_file<size, false>* a_object, unsigned int a_r_sym)
1006       : object(a_object), r_sym(a_r_sym)
1007     { }
1008
1009     // The object in which the local symbol is defined.
1010     Sized_relobj_file<size, false>* object;
1011     // The local symbol index in the object.
1012     unsigned int r_sym;
1013   };
1014
1015   // The GOT section.
1016   Output_data_got<64, false>* got_;
1017   // The PLT section.
1018   Output_data_plt_x86_64<size>* plt_;
1019   // The GOT PLT section.
1020   Output_data_got_plt_x86_64* got_plt_;
1021   // The GOT section for IRELATIVE relocations.
1022   Output_data_space* got_irelative_;
1023   // The GOT section for TLSDESC relocations.
1024   Output_data_got<64, false>* got_tlsdesc_;
1025   // The _GLOBAL_OFFSET_TABLE_ symbol.
1026   Symbol* global_offset_table_;
1027   // The dynamic reloc section.
1028   Reloc_section* rela_dyn_;
1029   // The section to use for IRELATIVE relocs.
1030   Reloc_section* rela_irelative_;
1031   // Relocs saved to avoid a COPY reloc.
1032   Copy_relocs<elfcpp::SHT_RELA, size, false> copy_relocs_;
1033   // Offset of the GOT entry for the TLS module index.
1034   unsigned int got_mod_index_offset_;
1035   // We handle R_X86_64_TLSDESC against a local symbol as a target
1036   // specific relocation.  Here we store the object and local symbol
1037   // index for the relocation.
1038   std::vector<Tlsdesc_info> tlsdesc_reloc_info_;
1039   // True if the _TLS_MODULE_BASE_ symbol has been defined.
1040   bool tls_base_symbol_defined_;
1041 };
1042
1043 template<>
1044 const Target::Target_info Target_x86_64<64>::x86_64_info =
1045 {
1046   64,                   // size
1047   false,                // is_big_endian
1048   elfcpp::EM_X86_64,    // machine_code
1049   false,                // has_make_symbol
1050   false,                // has_resolve
1051   true,                 // has_code_fill
1052   true,                 // is_default_stack_executable
1053   true,                 // can_icf_inline_merge_sections
1054   '\0',                 // wrap_char
1055   "/lib/ld64.so.1",     // program interpreter
1056   0x400000,             // default_text_segment_address
1057   0x1000,               // abi_pagesize (overridable by -z max-page-size)
1058   0x1000,               // common_pagesize (overridable by -z common-page-size)
1059   false,                // isolate_execinstr
1060   0,                    // rosegment_gap
1061   elfcpp::SHN_UNDEF,    // small_common_shndx
1062   elfcpp::SHN_X86_64_LCOMMON,   // large_common_shndx
1063   0,                    // small_common_section_flags
1064   elfcpp::SHF_X86_64_LARGE,     // large_common_section_flags
1065   NULL,                 // attributes_section
1066   NULL,                 // attributes_vendor
1067   "_start",             // entry_symbol_name
1068   32,                   // hash_entry_size
1069 };
1070
1071 template<>
1072 const Target::Target_info Target_x86_64<32>::x86_64_info =
1073 {
1074   32,                   // size
1075   false,                // is_big_endian
1076   elfcpp::EM_X86_64,    // machine_code
1077   false,                // has_make_symbol
1078   false,                // has_resolve
1079   true,                 // has_code_fill
1080   true,                 // is_default_stack_executable
1081   true,                 // can_icf_inline_merge_sections
1082   '\0',                 // wrap_char
1083   "/libx32/ldx32.so.1", // program interpreter
1084   0x400000,             // default_text_segment_address
1085   0x1000,               // abi_pagesize (overridable by -z max-page-size)
1086   0x1000,               // common_pagesize (overridable by -z common-page-size)
1087   false,                // isolate_execinstr
1088   0,                    // rosegment_gap
1089   elfcpp::SHN_UNDEF,    // small_common_shndx
1090   elfcpp::SHN_X86_64_LCOMMON,   // large_common_shndx
1091   0,                    // small_common_section_flags
1092   elfcpp::SHF_X86_64_LARGE,     // large_common_section_flags
1093   NULL,                 // attributes_section
1094   NULL,                 // attributes_vendor
1095   "_start",             // entry_symbol_name
1096   32,                   // hash_entry_size
1097 };
1098
1099 // This is called when a new output section is created.  This is where
1100 // we handle the SHF_X86_64_LARGE.
1101
1102 template<int size>
1103 void
1104 Target_x86_64<size>::do_new_output_section(Output_section* os) const
1105 {
1106   if ((os->flags() & elfcpp::SHF_X86_64_LARGE) != 0)
1107     os->set_is_large_section();
1108 }
1109
1110 // Get the GOT section, creating it if necessary.
1111
1112 template<int size>
1113 Output_data_got<64, false>*
1114 Target_x86_64<size>::got_section(Symbol_table* symtab, Layout* layout)
1115 {
1116   if (this->got_ == NULL)
1117     {
1118       gold_assert(symtab != NULL && layout != NULL);
1119
1120       // When using -z now, we can treat .got.plt as a relro section.
1121       // Without -z now, it is modified after program startup by lazy
1122       // PLT relocations.
1123       bool is_got_plt_relro = parameters->options().now();
1124       Output_section_order got_order = (is_got_plt_relro
1125                                         ? ORDER_RELRO
1126                                         : ORDER_RELRO_LAST);
1127       Output_section_order got_plt_order = (is_got_plt_relro
1128                                             ? ORDER_RELRO
1129                                             : ORDER_NON_RELRO_FIRST);
1130
1131       this->got_ = new Output_data_got<64, false>();
1132
1133       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
1134                                       (elfcpp::SHF_ALLOC
1135                                        | elfcpp::SHF_WRITE),
1136                                       this->got_, got_order, true);
1137
1138       this->got_plt_ = new Output_data_got_plt_x86_64(layout);
1139       layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1140                                       (elfcpp::SHF_ALLOC
1141                                        | elfcpp::SHF_WRITE),
1142                                       this->got_plt_, got_plt_order,
1143                                       is_got_plt_relro);
1144
1145       // The first three entries are reserved.
1146       this->got_plt_->set_current_data_size(3 * 8);
1147
1148       if (!is_got_plt_relro)
1149         {
1150           // Those bytes can go into the relro segment.
1151           layout->increase_relro(3 * 8);
1152         }
1153
1154       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
1155       this->global_offset_table_ =
1156         symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
1157                                       Symbol_table::PREDEFINED,
1158                                       this->got_plt_,
1159                                       0, 0, elfcpp::STT_OBJECT,
1160                                       elfcpp::STB_LOCAL,
1161                                       elfcpp::STV_HIDDEN, 0,
1162                                       false, false);
1163
1164       // If there are any IRELATIVE relocations, they get GOT entries
1165       // in .got.plt after the jump slot entries.
1166       this->got_irelative_ = new Output_data_space(8, "** GOT IRELATIVE PLT");
1167       layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1168                                       (elfcpp::SHF_ALLOC
1169                                        | elfcpp::SHF_WRITE),
1170                                       this->got_irelative_,
1171                                       got_plt_order, is_got_plt_relro);
1172
1173       // If there are any TLSDESC relocations, they get GOT entries in
1174       // .got.plt after the jump slot and IRELATIVE entries.
1175       this->got_tlsdesc_ = new Output_data_got<64, false>();
1176       layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1177                                       (elfcpp::SHF_ALLOC
1178                                        | elfcpp::SHF_WRITE),
1179                                       this->got_tlsdesc_,
1180                                       got_plt_order, is_got_plt_relro);
1181     }
1182
1183   return this->got_;
1184 }
1185
1186 // Get the dynamic reloc section, creating it if necessary.
1187
1188 template<int size>
1189 typename Target_x86_64<size>::Reloc_section*
1190 Target_x86_64<size>::rela_dyn_section(Layout* layout)
1191 {
1192   if (this->rela_dyn_ == NULL)
1193     {
1194       gold_assert(layout != NULL);
1195       this->rela_dyn_ = new Reloc_section(parameters->options().combreloc());
1196       layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
1197                                       elfcpp::SHF_ALLOC, this->rela_dyn_,
1198                                       ORDER_DYNAMIC_RELOCS, false);
1199     }
1200   return this->rela_dyn_;
1201 }
1202
1203 // Get the section to use for IRELATIVE relocs, creating it if
1204 // necessary.  These go in .rela.dyn, but only after all other dynamic
1205 // relocations.  They need to follow the other dynamic relocations so
1206 // that they can refer to global variables initialized by those
1207 // relocs.
1208
1209 template<int size>
1210 typename Target_x86_64<size>::Reloc_section*
1211 Target_x86_64<size>::rela_irelative_section(Layout* layout)
1212 {
1213   if (this->rela_irelative_ == NULL)
1214     {
1215       // Make sure we have already created the dynamic reloc section.
1216       this->rela_dyn_section(layout);
1217       this->rela_irelative_ = new Reloc_section(false);
1218       layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
1219                                       elfcpp::SHF_ALLOC, this->rela_irelative_,
1220                                       ORDER_DYNAMIC_RELOCS, false);
1221       gold_assert(this->rela_dyn_->output_section()
1222                   == this->rela_irelative_->output_section());
1223     }
1224   return this->rela_irelative_;
1225 }
1226
1227 // Write the first three reserved words of the .got.plt section.
1228 // The remainder of the section is written while writing the PLT
1229 // in Output_data_plt_i386::do_write.
1230
1231 void
1232 Output_data_got_plt_x86_64::do_write(Output_file* of)
1233 {
1234   // The first entry in the GOT is the address of the .dynamic section
1235   // aka the PT_DYNAMIC segment.  The next two entries are reserved.
1236   // We saved space for them when we created the section in
1237   // Target_x86_64::got_section.
1238   const off_t got_file_offset = this->offset();
1239   gold_assert(this->data_size() >= 24);
1240   unsigned char* const got_view = of->get_output_view(got_file_offset, 24);
1241   Output_section* dynamic = this->layout_->dynamic_section();
1242   uint64_t dynamic_addr = dynamic == NULL ? 0 : dynamic->address();
1243   elfcpp::Swap<64, false>::writeval(got_view, dynamic_addr);
1244   memset(got_view + 8, 0, 16);
1245   of->write_output_view(got_file_offset, 24, got_view);
1246 }
1247
1248 // Initialize the PLT section.
1249
1250 template<int size>
1251 void
1252 Output_data_plt_x86_64<size>::init(Layout* layout)
1253 {
1254   this->rel_ = new Reloc_section(false);
1255   layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
1256                                   elfcpp::SHF_ALLOC, this->rel_,
1257                                   ORDER_DYNAMIC_PLT_RELOCS, false);
1258 }
1259
1260 template<int size>
1261 void
1262 Output_data_plt_x86_64<size>::do_adjust_output_section(Output_section* os)
1263 {
1264   os->set_entsize(this->get_plt_entry_size());
1265 }
1266
1267 // Add an entry to the PLT.
1268
1269 template<int size>
1270 void
1271 Output_data_plt_x86_64<size>::add_entry(Symbol_table* symtab, Layout* layout,
1272                                         Symbol* gsym)
1273 {
1274   gold_assert(!gsym->has_plt_offset());
1275
1276   unsigned int plt_index;
1277   off_t plt_offset;
1278   section_offset_type got_offset;
1279
1280   unsigned int* pcount;
1281   unsigned int offset;
1282   unsigned int reserved;
1283   Output_section_data_build* got;
1284   if (gsym->type() == elfcpp::STT_GNU_IFUNC
1285       && gsym->can_use_relative_reloc(false))
1286     {
1287       pcount = &this->irelative_count_;
1288       offset = 0;
1289       reserved = 0;
1290       got = this->got_irelative_;
1291     }
1292   else
1293     {
1294       pcount = &this->count_;
1295       offset = 1;
1296       reserved = 3;
1297       got = this->got_plt_;
1298     }
1299
1300   if (!this->is_data_size_valid())
1301     {
1302       // Note that when setting the PLT offset for a non-IRELATIVE
1303       // entry we skip the initial reserved PLT entry.
1304       plt_index = *pcount + offset;
1305       plt_offset = plt_index * this->get_plt_entry_size();
1306
1307       ++*pcount;
1308
1309       got_offset = (plt_index - offset + reserved) * 8;
1310       gold_assert(got_offset == got->current_data_size());
1311
1312       // Every PLT entry needs a GOT entry which points back to the PLT
1313       // entry (this will be changed by the dynamic linker, normally
1314       // lazily when the function is called).
1315       got->set_current_data_size(got_offset + 8);
1316     }
1317   else
1318     {
1319       // FIXME: This is probably not correct for IRELATIVE relocs.
1320
1321       // For incremental updates, find an available slot.
1322       plt_offset = this->free_list_.allocate(this->get_plt_entry_size(),
1323                                              this->get_plt_entry_size(), 0);
1324       if (plt_offset == -1)
1325         gold_fallback(_("out of patch space (PLT);"
1326                         " relink with --incremental-full"));
1327
1328       // The GOT and PLT entries have a 1-1 correspondance, so the GOT offset
1329       // can be calculated from the PLT index, adjusting for the three
1330       // reserved entries at the beginning of the GOT.
1331       plt_index = plt_offset / this->get_plt_entry_size() - 1;
1332       got_offset = (plt_index - offset + reserved) * 8;
1333     }
1334
1335   gsym->set_plt_offset(plt_offset);
1336
1337   // Every PLT entry needs a reloc.
1338   this->add_relocation(symtab, layout, gsym, got_offset);
1339
1340   // Note that we don't need to save the symbol.  The contents of the
1341   // PLT are independent of which symbols are used.  The symbols only
1342   // appear in the relocations.
1343 }
1344
1345 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.  Return
1346 // the PLT offset.
1347
1348 template<int size>
1349 unsigned int
1350 Output_data_plt_x86_64<size>::add_local_ifunc_entry(
1351     Symbol_table* symtab,
1352     Layout* layout,
1353     Sized_relobj_file<size, false>* relobj,
1354     unsigned int local_sym_index)
1355 {
1356   unsigned int plt_offset = this->irelative_count_ * this->get_plt_entry_size();
1357   ++this->irelative_count_;
1358
1359   section_offset_type got_offset = this->got_irelative_->current_data_size();
1360
1361   // Every PLT entry needs a GOT entry which points back to the PLT
1362   // entry.
1363   this->got_irelative_->set_current_data_size(got_offset + 8);
1364
1365   // Every PLT entry needs a reloc.
1366   Reloc_section* rela = this->rela_irelative(symtab, layout);
1367   rela->add_symbolless_local_addend(relobj, local_sym_index,
1368                                     elfcpp::R_X86_64_IRELATIVE,
1369                                     this->got_irelative_, got_offset, 0);
1370
1371   return plt_offset;
1372 }
1373
1374 // Add the relocation for a PLT entry.
1375
1376 template<int size>
1377 void
1378 Output_data_plt_x86_64<size>::add_relocation(Symbol_table* symtab,
1379                                              Layout* layout,
1380                                              Symbol* gsym,
1381                                              unsigned int got_offset)
1382 {
1383   if (gsym->type() == elfcpp::STT_GNU_IFUNC
1384       && gsym->can_use_relative_reloc(false))
1385     {
1386       Reloc_section* rela = this->rela_irelative(symtab, layout);
1387       rela->add_symbolless_global_addend(gsym, elfcpp::R_X86_64_IRELATIVE,
1388                                          this->got_irelative_, got_offset, 0);
1389     }
1390   else
1391     {
1392       gsym->set_needs_dynsym_entry();
1393       this->rel_->add_global(gsym, elfcpp::R_X86_64_JUMP_SLOT, this->got_plt_,
1394                              got_offset, 0);
1395     }
1396 }
1397
1398 // Return where the TLSDESC relocations should go, creating it if
1399 // necessary.  These follow the JUMP_SLOT relocations.
1400
1401 template<int size>
1402 typename Output_data_plt_x86_64<size>::Reloc_section*
1403 Output_data_plt_x86_64<size>::rela_tlsdesc(Layout* layout)
1404 {
1405   if (this->tlsdesc_rel_ == NULL)
1406     {
1407       this->tlsdesc_rel_ = new Reloc_section(false);
1408       layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
1409                                       elfcpp::SHF_ALLOC, this->tlsdesc_rel_,
1410                                       ORDER_DYNAMIC_PLT_RELOCS, false);
1411       gold_assert(this->tlsdesc_rel_->output_section()
1412                   == this->rel_->output_section());
1413     }
1414   return this->tlsdesc_rel_;
1415 }
1416
1417 // Return where the IRELATIVE relocations should go in the PLT.  These
1418 // follow the JUMP_SLOT and the TLSDESC relocations.
1419
1420 template<int size>
1421 typename Output_data_plt_x86_64<size>::Reloc_section*
1422 Output_data_plt_x86_64<size>::rela_irelative(Symbol_table* symtab,
1423                                              Layout* layout)
1424 {
1425   if (this->irelative_rel_ == NULL)
1426     {
1427       // Make sure we have a place for the TLSDESC relocations, in
1428       // case we see any later on.
1429       this->rela_tlsdesc(layout);
1430       this->irelative_rel_ = new Reloc_section(false);
1431       layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
1432                                       elfcpp::SHF_ALLOC, this->irelative_rel_,
1433                                       ORDER_DYNAMIC_PLT_RELOCS, false);
1434       gold_assert(this->irelative_rel_->output_section()
1435                   == this->rel_->output_section());
1436
1437       if (parameters->doing_static_link())
1438         {
1439           // A statically linked executable will only have a .rela.plt
1440           // section to hold R_X86_64_IRELATIVE relocs for
1441           // STT_GNU_IFUNC symbols.  The library will use these
1442           // symbols to locate the IRELATIVE relocs at program startup
1443           // time.
1444           symtab->define_in_output_data("__rela_iplt_start", NULL,
1445                                         Symbol_table::PREDEFINED,
1446                                         this->irelative_rel_, 0, 0,
1447                                         elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1448                                         elfcpp::STV_HIDDEN, 0, false, true);
1449           symtab->define_in_output_data("__rela_iplt_end", NULL,
1450                                         Symbol_table::PREDEFINED,
1451                                         this->irelative_rel_, 0, 0,
1452                                         elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1453                                         elfcpp::STV_HIDDEN, 0, true, true);
1454         }
1455     }
1456   return this->irelative_rel_;
1457 }
1458
1459 // Return the PLT address to use for a global symbol.
1460
1461 template<int size>
1462 uint64_t
1463 Output_data_plt_x86_64<size>::address_for_global(const Symbol* gsym)
1464 {
1465   uint64_t offset = 0;
1466   if (gsym->type() == elfcpp::STT_GNU_IFUNC
1467       && gsym->can_use_relative_reloc(false))
1468     offset = (this->count_ + 1) * this->get_plt_entry_size();
1469   return this->address() + offset + gsym->plt_offset();
1470 }
1471
1472 // Return the PLT address to use for a local symbol.  These are always
1473 // IRELATIVE relocs.
1474
1475 template<int size>
1476 uint64_t
1477 Output_data_plt_x86_64<size>::address_for_local(const Relobj* object,
1478                                                 unsigned int r_sym)
1479 {
1480   return (this->address()
1481           + (this->count_ + 1) * this->get_plt_entry_size()
1482           + object->local_plt_offset(r_sym));
1483 }
1484
1485 // Set the final size.
1486 template<int size>
1487 void
1488 Output_data_plt_x86_64<size>::set_final_data_size()
1489 {
1490   unsigned int count = this->count_ + this->irelative_count_;
1491   if (this->has_tlsdesc_entry())
1492     ++count;
1493   this->set_data_size((count + 1) * this->get_plt_entry_size());
1494 }
1495
1496 // The first entry in the PLT for an executable.
1497
1498 template<int size>
1499 const unsigned char
1500 Output_data_plt_x86_64_standard<size>::first_plt_entry[plt_entry_size] =
1501 {
1502   // From AMD64 ABI Draft 0.98, page 76
1503   0xff, 0x35,   // pushq contents of memory address
1504   0, 0, 0, 0,   // replaced with address of .got + 8
1505   0xff, 0x25,   // jmp indirect
1506   0, 0, 0, 0,   // replaced with address of .got + 16
1507   0x90, 0x90, 0x90, 0x90   // noop (x4)
1508 };
1509
1510 template<int size>
1511 void
1512 Output_data_plt_x86_64_standard<size>::do_fill_first_plt_entry(
1513     unsigned char* pov,
1514     typename elfcpp::Elf_types<size>::Elf_Addr got_address,
1515     typename elfcpp::Elf_types<size>::Elf_Addr plt_address)
1516 {
1517   memcpy(pov, first_plt_entry, plt_entry_size);
1518   // We do a jmp relative to the PC at the end of this instruction.
1519   elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1520                                               (got_address + 8
1521                                                - (plt_address + 6)));
1522   elfcpp::Swap<32, false>::writeval(pov + 8,
1523                                     (got_address + 16
1524                                      - (plt_address + 12)));
1525 }
1526
1527 // Subsequent entries in the PLT for an executable.
1528
1529 template<int size>
1530 const unsigned char
1531 Output_data_plt_x86_64_standard<size>::plt_entry[plt_entry_size] =
1532 {
1533   // From AMD64 ABI Draft 0.98, page 76
1534   0xff, 0x25,   // jmpq indirect
1535   0, 0, 0, 0,   // replaced with address of symbol in .got
1536   0x68,         // pushq immediate
1537   0, 0, 0, 0,   // replaced with offset into relocation table
1538   0xe9,         // jmpq relative
1539   0, 0, 0, 0    // replaced with offset to start of .plt
1540 };
1541
1542 template<int size>
1543 unsigned int
1544 Output_data_plt_x86_64_standard<size>::do_fill_plt_entry(
1545     unsigned char* pov,
1546     typename elfcpp::Elf_types<size>::Elf_Addr got_address,
1547     typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
1548     unsigned int got_offset,
1549     unsigned int plt_offset,
1550     unsigned int plt_index)
1551 {
1552   // Check PC-relative offset overflow in PLT entry.
1553   uint64_t plt_got_pcrel_offset = (got_address + got_offset
1554                                    - (plt_address + plt_offset + 6));
1555   if (Bits<32>::has_overflow(plt_got_pcrel_offset))
1556     gold_error(_("PC-relative offset overflow in PLT entry %d"),
1557                plt_index + 1);
1558
1559   memcpy(pov, plt_entry, plt_entry_size);
1560   elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1561                                               plt_got_pcrel_offset);
1562
1563   elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_index);
1564   elfcpp::Swap<32, false>::writeval(pov + 12,
1565                                     - (plt_offset + plt_entry_size));
1566
1567   return 6;
1568 }
1569
1570 // The reserved TLSDESC entry in the PLT for an executable.
1571
1572 template<int size>
1573 const unsigned char
1574 Output_data_plt_x86_64_standard<size>::tlsdesc_plt_entry[plt_entry_size] =
1575 {
1576   // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
1577   // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
1578   0xff, 0x35,   // pushq x(%rip)
1579   0, 0, 0, 0,   // replaced with address of linkmap GOT entry (at PLTGOT + 8)
1580   0xff, 0x25,   // jmpq *y(%rip)
1581   0, 0, 0, 0,   // replaced with offset of reserved TLSDESC_GOT entry
1582   0x0f, 0x1f,   // nop
1583   0x40, 0
1584 };
1585
1586 template<int size>
1587 void
1588 Output_data_plt_x86_64_standard<size>::do_fill_tlsdesc_entry(
1589     unsigned char* pov,
1590     typename elfcpp::Elf_types<size>::Elf_Addr got_address,
1591     typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
1592     typename elfcpp::Elf_types<size>::Elf_Addr got_base,
1593     unsigned int tlsdesc_got_offset,
1594     unsigned int plt_offset)
1595 {
1596   memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
1597   elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1598                                               (got_address + 8
1599                                                - (plt_address + plt_offset
1600                                                   + 6)));
1601   elfcpp::Swap_unaligned<32, false>::writeval(pov + 8,
1602                                               (got_base
1603                                                + tlsdesc_got_offset
1604                                                - (plt_address + plt_offset
1605                                                   + 12)));
1606 }
1607
1608 // The .eh_frame unwind information for the PLT.
1609
1610 template<int size>
1611 const unsigned char
1612 Output_data_plt_x86_64<size>::plt_eh_frame_cie[plt_eh_frame_cie_size] =
1613 {
1614   1,                            // CIE version.
1615   'z',                          // Augmentation: augmentation size included.
1616   'R',                          // Augmentation: FDE encoding included.
1617   '\0',                         // End of augmentation string.
1618   1,                            // Code alignment factor.
1619   0x78,                         // Data alignment factor.
1620   16,                           // Return address column.
1621   1,                            // Augmentation size.
1622   (elfcpp::DW_EH_PE_pcrel       // FDE encoding.
1623    | elfcpp::DW_EH_PE_sdata4),
1624   elfcpp::DW_CFA_def_cfa, 7, 8, // DW_CFA_def_cfa: r7 (rsp) ofs 8.
1625   elfcpp::DW_CFA_offset + 16, 1,// DW_CFA_offset: r16 (rip) at cfa-8.
1626   elfcpp::DW_CFA_nop,           // Align to 16 bytes.
1627   elfcpp::DW_CFA_nop
1628 };
1629
1630 template<int size>
1631 const unsigned char
1632 Output_data_plt_x86_64_standard<size>::plt_eh_frame_fde[plt_eh_frame_fde_size] =
1633 {
1634   0, 0, 0, 0,                           // Replaced with offset to .plt.
1635   0, 0, 0, 0,                           // Replaced with size of .plt.
1636   0,                                    // Augmentation size.
1637   elfcpp::DW_CFA_def_cfa_offset, 16,    // DW_CFA_def_cfa_offset: 16.
1638   elfcpp::DW_CFA_advance_loc + 6,       // Advance 6 to __PLT__ + 6.
1639   elfcpp::DW_CFA_def_cfa_offset, 24,    // DW_CFA_def_cfa_offset: 24.
1640   elfcpp::DW_CFA_advance_loc + 10,      // Advance 10 to __PLT__ + 16.
1641   elfcpp::DW_CFA_def_cfa_expression,    // DW_CFA_def_cfa_expression.
1642   11,                                   // Block length.
1643   elfcpp::DW_OP_breg7, 8,               // Push %rsp + 8.
1644   elfcpp::DW_OP_breg16, 0,              // Push %rip.
1645   elfcpp::DW_OP_lit15,                  // Push 0xf.
1646   elfcpp::DW_OP_and,                    // & (%rip & 0xf).
1647   elfcpp::DW_OP_lit11,                  // Push 0xb.
1648   elfcpp::DW_OP_ge,                     // >= ((%rip & 0xf) >= 0xb)
1649   elfcpp::DW_OP_lit3,                   // Push 3.
1650   elfcpp::DW_OP_shl,                    // << (((%rip & 0xf) >= 0xb) << 3)
1651   elfcpp::DW_OP_plus,                   // + ((((%rip&0xf)>=0xb)<<3)+%rsp+8
1652   elfcpp::DW_CFA_nop,                   // Align to 32 bytes.
1653   elfcpp::DW_CFA_nop,
1654   elfcpp::DW_CFA_nop,
1655   elfcpp::DW_CFA_nop
1656 };
1657
1658 // Write out the PLT.  This uses the hand-coded instructions above,
1659 // and adjusts them as needed.  This is specified by the AMD64 ABI.
1660
1661 template<int size>
1662 void
1663 Output_data_plt_x86_64<size>::do_write(Output_file* of)
1664 {
1665   const off_t offset = this->offset();
1666   const section_size_type oview_size =
1667     convert_to_section_size_type(this->data_size());
1668   unsigned char* const oview = of->get_output_view(offset, oview_size);
1669
1670   const off_t got_file_offset = this->got_plt_->offset();
1671   gold_assert(parameters->incremental_update()
1672               || (got_file_offset + this->got_plt_->data_size()
1673                   == this->got_irelative_->offset()));
1674   const section_size_type got_size =
1675     convert_to_section_size_type(this->got_plt_->data_size()
1676                                  + this->got_irelative_->data_size());
1677   unsigned char* const got_view = of->get_output_view(got_file_offset,
1678                                                       got_size);
1679
1680   unsigned char* pov = oview;
1681
1682   // The base address of the .plt section.
1683   typename elfcpp::Elf_types<size>::Elf_Addr plt_address = this->address();
1684   // The base address of the .got section.
1685   typename elfcpp::Elf_types<size>::Elf_Addr got_base = this->got_->address();
1686   // The base address of the PLT portion of the .got section,
1687   // which is where the GOT pointer will point, and where the
1688   // three reserved GOT entries are located.
1689   typename elfcpp::Elf_types<size>::Elf_Addr got_address
1690     = this->got_plt_->address();
1691
1692   this->fill_first_plt_entry(pov, got_address, plt_address);
1693   pov += this->get_plt_entry_size();
1694
1695   // The first three entries in the GOT are reserved, and are written
1696   // by Output_data_got_plt_x86_64::do_write.
1697   unsigned char* got_pov = got_view + 24;
1698
1699   unsigned int plt_offset = this->get_plt_entry_size();
1700   unsigned int got_offset = 24;
1701   const unsigned int count = this->count_ + this->irelative_count_;
1702   for (unsigned int plt_index = 0;
1703        plt_index < count;
1704        ++plt_index,
1705          pov += this->get_plt_entry_size(),
1706          got_pov += 8,
1707          plt_offset += this->get_plt_entry_size(),
1708          got_offset += 8)
1709     {
1710       // Set and adjust the PLT entry itself.
1711       unsigned int lazy_offset = this->fill_plt_entry(pov,
1712                                                       got_address, plt_address,
1713                                                       got_offset, plt_offset,
1714                                                       plt_index);
1715
1716       // Set the entry in the GOT.
1717       elfcpp::Swap<64, false>::writeval(got_pov,
1718                                         plt_address + plt_offset + lazy_offset);
1719     }
1720
1721   if (this->has_tlsdesc_entry())
1722     {
1723       // Set and adjust the reserved TLSDESC PLT entry.
1724       unsigned int tlsdesc_got_offset = this->get_tlsdesc_got_offset();
1725       this->fill_tlsdesc_entry(pov, got_address, plt_address, got_base,
1726                                tlsdesc_got_offset, plt_offset);
1727       pov += this->get_plt_entry_size();
1728     }
1729
1730   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
1731   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
1732
1733   of->write_output_view(offset, oview_size, oview);
1734   of->write_output_view(got_file_offset, got_size, got_view);
1735 }
1736
1737 // Create the PLT section.
1738
1739 template<int size>
1740 void
1741 Target_x86_64<size>::make_plt_section(Symbol_table* symtab, Layout* layout)
1742 {
1743   if (this->plt_ == NULL)
1744     {
1745       // Create the GOT sections first.
1746       this->got_section(symtab, layout);
1747
1748       this->plt_ = this->make_data_plt(layout, this->got_, this->got_plt_,
1749                                        this->got_irelative_);
1750
1751       // Add unwind information if requested.
1752       if (parameters->options().ld_generated_unwind_info())
1753         this->plt_->add_eh_frame(layout);
1754
1755       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
1756                                       (elfcpp::SHF_ALLOC
1757                                        | elfcpp::SHF_EXECINSTR),
1758                                       this->plt_, ORDER_PLT, false);
1759
1760       // Make the sh_info field of .rela.plt point to .plt.
1761       Output_section* rela_plt_os = this->plt_->rela_plt()->output_section();
1762       rela_plt_os->set_info_section(this->plt_->output_section());
1763     }
1764 }
1765
1766 // Return the section for TLSDESC relocations.
1767
1768 template<int size>
1769 typename Target_x86_64<size>::Reloc_section*
1770 Target_x86_64<size>::rela_tlsdesc_section(Layout* layout) const
1771 {
1772   return this->plt_section()->rela_tlsdesc(layout);
1773 }
1774
1775 // Create a PLT entry for a global symbol.
1776
1777 template<int size>
1778 void
1779 Target_x86_64<size>::make_plt_entry(Symbol_table* symtab, Layout* layout,
1780                                     Symbol* gsym)
1781 {
1782   if (gsym->has_plt_offset())
1783     return;
1784
1785   if (this->plt_ == NULL)
1786     this->make_plt_section(symtab, layout);
1787
1788   this->plt_->add_entry(symtab, layout, gsym);
1789 }
1790
1791 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1792
1793 template<int size>
1794 void
1795 Target_x86_64<size>::make_local_ifunc_plt_entry(
1796     Symbol_table* symtab, Layout* layout,
1797     Sized_relobj_file<size, false>* relobj,
1798     unsigned int local_sym_index)
1799 {
1800   if (relobj->local_has_plt_offset(local_sym_index))
1801     return;
1802   if (this->plt_ == NULL)
1803     this->make_plt_section(symtab, layout);
1804   unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout,
1805                                                               relobj,
1806                                                               local_sym_index);
1807   relobj->set_local_plt_offset(local_sym_index, plt_offset);
1808 }
1809
1810 // Return the number of entries in the PLT.
1811
1812 template<int size>
1813 unsigned int
1814 Target_x86_64<size>::plt_entry_count() const
1815 {
1816   if (this->plt_ == NULL)
1817     return 0;
1818   return this->plt_->entry_count();
1819 }
1820
1821 // Return the offset of the first non-reserved PLT entry.
1822
1823 template<int size>
1824 unsigned int
1825 Target_x86_64<size>::first_plt_entry_offset() const
1826 {
1827   return this->plt_->first_plt_entry_offset();
1828 }
1829
1830 // Return the size of each PLT entry.
1831
1832 template<int size>
1833 unsigned int
1834 Target_x86_64<size>::plt_entry_size() const
1835 {
1836   return this->plt_->get_plt_entry_size();
1837 }
1838
1839 // Create the GOT and PLT sections for an incremental update.
1840
1841 template<int size>
1842 Output_data_got_base*
1843 Target_x86_64<size>::init_got_plt_for_update(Symbol_table* symtab,
1844                                        Layout* layout,
1845                                        unsigned int got_count,
1846                                        unsigned int plt_count)
1847 {
1848   gold_assert(this->got_ == NULL);
1849
1850   this->got_ = new Output_data_got<64, false>(got_count * 8);
1851   layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
1852                                   (elfcpp::SHF_ALLOC
1853                                    | elfcpp::SHF_WRITE),
1854                                   this->got_, ORDER_RELRO_LAST,
1855                                   true);
1856
1857   // Add the three reserved entries.
1858   this->got_plt_ = new Output_data_got_plt_x86_64(layout, (plt_count + 3) * 8);
1859   layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1860                                   (elfcpp::SHF_ALLOC
1861                                    | elfcpp::SHF_WRITE),
1862                                   this->got_plt_, ORDER_NON_RELRO_FIRST,
1863                                   false);
1864
1865   // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
1866   this->global_offset_table_ =
1867     symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
1868                                   Symbol_table::PREDEFINED,
1869                                   this->got_plt_,
1870                                   0, 0, elfcpp::STT_OBJECT,
1871                                   elfcpp::STB_LOCAL,
1872                                   elfcpp::STV_HIDDEN, 0,
1873                                   false, false);
1874
1875   // If there are any TLSDESC relocations, they get GOT entries in
1876   // .got.plt after the jump slot entries.
1877   // FIXME: Get the count for TLSDESC entries.
1878   this->got_tlsdesc_ = new Output_data_got<64, false>(0);
1879   layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1880                                   elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
1881                                   this->got_tlsdesc_,
1882                                   ORDER_NON_RELRO_FIRST, false);
1883
1884   // If there are any IRELATIVE relocations, they get GOT entries in
1885   // .got.plt after the jump slot and TLSDESC entries.
1886   this->got_irelative_ = new Output_data_space(0, 8, "** GOT IRELATIVE PLT");
1887   layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1888                                   elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
1889                                   this->got_irelative_,
1890                                   ORDER_NON_RELRO_FIRST, false);
1891
1892   // Create the PLT section.
1893   this->plt_ = this->make_data_plt(layout, this->got_,
1894                                    this->got_plt_,
1895                                    this->got_irelative_,
1896                                    plt_count);
1897
1898   // Add unwind information if requested.
1899   if (parameters->options().ld_generated_unwind_info())
1900     this->plt_->add_eh_frame(layout);
1901
1902   layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
1903                                   elfcpp::SHF_ALLOC | elfcpp::SHF_EXECINSTR,
1904                                   this->plt_, ORDER_PLT, false);
1905
1906   // Make the sh_info field of .rela.plt point to .plt.
1907   Output_section* rela_plt_os = this->plt_->rela_plt()->output_section();
1908   rela_plt_os->set_info_section(this->plt_->output_section());
1909
1910   // Create the rela_dyn section.
1911   this->rela_dyn_section(layout);
1912
1913   return this->got_;
1914 }
1915
1916 // Reserve a GOT entry for a local symbol, and regenerate any
1917 // necessary dynamic relocations.
1918
1919 template<int size>
1920 void
1921 Target_x86_64<size>::reserve_local_got_entry(
1922     unsigned int got_index,
1923     Sized_relobj<size, false>* obj,
1924     unsigned int r_sym,
1925     unsigned int got_type)
1926 {
1927   unsigned int got_offset = got_index * 8;
1928   Reloc_section* rela_dyn = this->rela_dyn_section(NULL);
1929
1930   this->got_->reserve_local(got_index, obj, r_sym, got_type);
1931   switch (got_type)
1932     {
1933     case GOT_TYPE_STANDARD:
1934       if (parameters->options().output_is_position_independent())
1935         rela_dyn->add_local_relative(obj, r_sym, elfcpp::R_X86_64_RELATIVE,
1936                                      this->got_, got_offset, 0, false);
1937       break;
1938     case GOT_TYPE_TLS_OFFSET:
1939       rela_dyn->add_local(obj, r_sym, elfcpp::R_X86_64_TPOFF64,
1940                           this->got_, got_offset, 0);
1941       break;
1942     case GOT_TYPE_TLS_PAIR:
1943       this->got_->reserve_slot(got_index + 1);
1944       rela_dyn->add_local(obj, r_sym, elfcpp::R_X86_64_DTPMOD64,
1945                           this->got_, got_offset, 0);
1946       break;
1947     case GOT_TYPE_TLS_DESC:
1948       gold_fatal(_("TLS_DESC not yet supported for incremental linking"));
1949       // this->got_->reserve_slot(got_index + 1);
1950       // rela_dyn->add_target_specific(elfcpp::R_X86_64_TLSDESC, arg,
1951       //                               this->got_, got_offset, 0);
1952       break;
1953     default:
1954       gold_unreachable();
1955     }
1956 }
1957
1958 // Reserve a GOT entry for a global symbol, and regenerate any
1959 // necessary dynamic relocations.
1960
1961 template<int size>
1962 void
1963 Target_x86_64<size>::reserve_global_got_entry(unsigned int got_index,
1964                                               Symbol* gsym,
1965                                               unsigned int got_type)
1966 {
1967   unsigned int got_offset = got_index * 8;
1968   Reloc_section* rela_dyn = this->rela_dyn_section(NULL);
1969
1970   this->got_->reserve_global(got_index, gsym, got_type);
1971   switch (got_type)
1972     {
1973     case GOT_TYPE_STANDARD:
1974       if (!gsym->final_value_is_known())
1975         {
1976           if (gsym->is_from_dynobj()
1977               || gsym->is_undefined()
1978               || gsym->is_preemptible()
1979               || gsym->type() == elfcpp::STT_GNU_IFUNC)
1980             rela_dyn->add_global(gsym, elfcpp::R_X86_64_GLOB_DAT,
1981                                  this->got_, got_offset, 0);
1982           else
1983             rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_RELATIVE,
1984                                           this->got_, got_offset, 0, false);
1985         }
1986       break;
1987     case GOT_TYPE_TLS_OFFSET:
1988       rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_TPOFF64,
1989                                     this->got_, got_offset, 0, false);
1990       break;
1991     case GOT_TYPE_TLS_PAIR:
1992       this->got_->reserve_slot(got_index + 1);
1993       rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_DTPMOD64,
1994                                     this->got_, got_offset, 0, false);
1995       rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_DTPOFF64,
1996                                     this->got_, got_offset + 8, 0, false);
1997       break;
1998     case GOT_TYPE_TLS_DESC:
1999       this->got_->reserve_slot(got_index + 1);
2000       rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_TLSDESC,
2001                                     this->got_, got_offset, 0, false);
2002       break;
2003     default:
2004       gold_unreachable();
2005     }
2006 }
2007
2008 // Register an existing PLT entry for a global symbol.
2009
2010 template<int size>
2011 void
2012 Target_x86_64<size>::register_global_plt_entry(Symbol_table* symtab,
2013                                                Layout* layout,
2014                                                unsigned int plt_index,
2015                                                Symbol* gsym)
2016 {
2017   gold_assert(this->plt_ != NULL);
2018   gold_assert(!gsym->has_plt_offset());
2019
2020   this->plt_->reserve_slot(plt_index);
2021
2022   gsym->set_plt_offset((plt_index + 1) * this->plt_entry_size());
2023
2024   unsigned int got_offset = (plt_index + 3) * 8;
2025   this->plt_->add_relocation(symtab, layout, gsym, got_offset);
2026 }
2027
2028 // Force a COPY relocation for a given symbol.
2029
2030 template<int size>
2031 void
2032 Target_x86_64<size>::emit_copy_reloc(
2033     Symbol_table* symtab, Symbol* sym, Output_section* os, off_t offset)
2034 {
2035   this->copy_relocs_.emit_copy_reloc(symtab,
2036                                      symtab->get_sized_symbol<size>(sym),
2037                                      os,
2038                                      offset,
2039                                      this->rela_dyn_section(NULL));
2040 }
2041
2042 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
2043
2044 template<int size>
2045 void
2046 Target_x86_64<size>::define_tls_base_symbol(Symbol_table* symtab,
2047                                             Layout* layout)
2048 {
2049   if (this->tls_base_symbol_defined_)
2050     return;
2051
2052   Output_segment* tls_segment = layout->tls_segment();
2053   if (tls_segment != NULL)
2054     {
2055       bool is_exec = parameters->options().output_is_executable();
2056       symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
2057                                        Symbol_table::PREDEFINED,
2058                                        tls_segment, 0, 0,
2059                                        elfcpp::STT_TLS,
2060                                        elfcpp::STB_LOCAL,
2061                                        elfcpp::STV_HIDDEN, 0,
2062                                        (is_exec
2063                                         ? Symbol::SEGMENT_END
2064                                         : Symbol::SEGMENT_START),
2065                                        true);
2066     }
2067   this->tls_base_symbol_defined_ = true;
2068 }
2069
2070 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
2071
2072 template<int size>
2073 void
2074 Target_x86_64<size>::reserve_tlsdesc_entries(Symbol_table* symtab,
2075                                              Layout* layout)
2076 {
2077   if (this->plt_ == NULL)
2078     this->make_plt_section(symtab, layout);
2079
2080   if (!this->plt_->has_tlsdesc_entry())
2081     {
2082       // Allocate the TLSDESC_GOT entry.
2083       Output_data_got<64, false>* got = this->got_section(symtab, layout);
2084       unsigned int got_offset = got->add_constant(0);
2085
2086       // Allocate the TLSDESC_PLT entry.
2087       this->plt_->reserve_tlsdesc_entry(got_offset);
2088     }
2089 }
2090
2091 // Create a GOT entry for the TLS module index.
2092
2093 template<int size>
2094 unsigned int
2095 Target_x86_64<size>::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
2096                                          Sized_relobj_file<size, false>* object)
2097 {
2098   if (this->got_mod_index_offset_ == -1U)
2099     {
2100       gold_assert(symtab != NULL && layout != NULL && object != NULL);
2101       Reloc_section* rela_dyn = this->rela_dyn_section(layout);
2102       Output_data_got<64, false>* got = this->got_section(symtab, layout);
2103       unsigned int got_offset = got->add_constant(0);
2104       rela_dyn->add_local(object, 0, elfcpp::R_X86_64_DTPMOD64, got,
2105                           got_offset, 0);
2106       got->add_constant(0);
2107       this->got_mod_index_offset_ = got_offset;
2108     }
2109   return this->got_mod_index_offset_;
2110 }
2111
2112 // Optimize the TLS relocation type based on what we know about the
2113 // symbol.  IS_FINAL is true if the final address of this symbol is
2114 // known at link time.
2115
2116 template<int size>
2117 tls::Tls_optimization
2118 Target_x86_64<size>::optimize_tls_reloc(bool is_final, int r_type)
2119 {
2120   // If we are generating a shared library, then we can't do anything
2121   // in the linker.
2122   if (parameters->options().shared())
2123     return tls::TLSOPT_NONE;
2124
2125   switch (r_type)
2126     {
2127     case elfcpp::R_X86_64_TLSGD:
2128     case elfcpp::R_X86_64_GOTPC32_TLSDESC:
2129     case elfcpp::R_X86_64_TLSDESC_CALL:
2130       // These are General-Dynamic which permits fully general TLS
2131       // access.  Since we know that we are generating an executable,
2132       // we can convert this to Initial-Exec.  If we also know that
2133       // this is a local symbol, we can further switch to Local-Exec.
2134       if (is_final)
2135         return tls::TLSOPT_TO_LE;
2136       return tls::TLSOPT_TO_IE;
2137
2138     case elfcpp::R_X86_64_TLSLD:
2139       // This is Local-Dynamic, which refers to a local symbol in the
2140       // dynamic TLS block.  Since we know that we generating an
2141       // executable, we can switch to Local-Exec.
2142       return tls::TLSOPT_TO_LE;
2143
2144     case elfcpp::R_X86_64_DTPOFF32:
2145     case elfcpp::R_X86_64_DTPOFF64:
2146       // Another Local-Dynamic reloc.
2147       return tls::TLSOPT_TO_LE;
2148
2149     case elfcpp::R_X86_64_GOTTPOFF:
2150       // These are Initial-Exec relocs which get the thread offset
2151       // from the GOT.  If we know that we are linking against the
2152       // local symbol, we can switch to Local-Exec, which links the
2153       // thread offset into the instruction.
2154       if (is_final)
2155         return tls::TLSOPT_TO_LE;
2156       return tls::TLSOPT_NONE;
2157
2158     case elfcpp::R_X86_64_TPOFF32:
2159       // When we already have Local-Exec, there is nothing further we
2160       // can do.
2161       return tls::TLSOPT_NONE;
2162
2163     default:
2164       gold_unreachable();
2165     }
2166 }
2167
2168 // Get the Reference_flags for a particular relocation.
2169
2170 template<int size>
2171 int
2172 Target_x86_64<size>::Scan::get_reference_flags(unsigned int r_type)
2173 {
2174   switch (r_type)
2175     {
2176     case elfcpp::R_X86_64_NONE:
2177     case elfcpp::R_X86_64_GNU_VTINHERIT:
2178     case elfcpp::R_X86_64_GNU_VTENTRY:
2179     case elfcpp::R_X86_64_GOTPC32:
2180     case elfcpp::R_X86_64_GOTPC64:
2181       // No symbol reference.
2182       return 0;
2183
2184     case elfcpp::R_X86_64_64:
2185     case elfcpp::R_X86_64_32:
2186     case elfcpp::R_X86_64_32S:
2187     case elfcpp::R_X86_64_16:
2188     case elfcpp::R_X86_64_8:
2189       return Symbol::ABSOLUTE_REF;
2190
2191     case elfcpp::R_X86_64_PC64:
2192     case elfcpp::R_X86_64_PC32:
2193     case elfcpp::R_X86_64_PC32_BND:
2194     case elfcpp::R_X86_64_PC16:
2195     case elfcpp::R_X86_64_PC8:
2196     case elfcpp::R_X86_64_GOTOFF64:
2197       return Symbol::RELATIVE_REF;
2198
2199     case elfcpp::R_X86_64_PLT32:
2200     case elfcpp::R_X86_64_PLT32_BND:
2201     case elfcpp::R_X86_64_PLTOFF64:
2202       return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
2203
2204     case elfcpp::R_X86_64_GOT64:
2205     case elfcpp::R_X86_64_GOT32:
2206     case elfcpp::R_X86_64_GOTPCREL64:
2207     case elfcpp::R_X86_64_GOTPCREL:
2208     case elfcpp::R_X86_64_GOTPCRELX:
2209     case elfcpp::R_X86_64_REX_GOTPCRELX:
2210     case elfcpp::R_X86_64_GOTPLT64:
2211       // Absolute in GOT.
2212       return Symbol::ABSOLUTE_REF;
2213
2214     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
2215     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
2216     case elfcpp::R_X86_64_TLSDESC_CALL:
2217     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
2218     case elfcpp::R_X86_64_DTPOFF32:
2219     case elfcpp::R_X86_64_DTPOFF64:
2220     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
2221     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
2222       return Symbol::TLS_REF;
2223
2224     case elfcpp::R_X86_64_COPY:
2225     case elfcpp::R_X86_64_GLOB_DAT:
2226     case elfcpp::R_X86_64_JUMP_SLOT:
2227     case elfcpp::R_X86_64_RELATIVE:
2228     case elfcpp::R_X86_64_IRELATIVE:
2229     case elfcpp::R_X86_64_TPOFF64:
2230     case elfcpp::R_X86_64_DTPMOD64:
2231     case elfcpp::R_X86_64_TLSDESC:
2232     case elfcpp::R_X86_64_SIZE32:
2233     case elfcpp::R_X86_64_SIZE64:
2234     default:
2235       // Not expected.  We will give an error later.
2236       return 0;
2237     }
2238 }
2239
2240 // Report an unsupported relocation against a local symbol.
2241
2242 template<int size>
2243 void
2244 Target_x86_64<size>::Scan::unsupported_reloc_local(
2245      Sized_relobj_file<size, false>* object,
2246      unsigned int r_type)
2247 {
2248   gold_error(_("%s: unsupported reloc %u against local symbol"),
2249              object->name().c_str(), r_type);
2250 }
2251
2252 // We are about to emit a dynamic relocation of type R_TYPE.  If the
2253 // dynamic linker does not support it, issue an error.  The GNU linker
2254 // only issues a non-PIC error for an allocated read-only section.
2255 // Here we know the section is allocated, but we don't know that it is
2256 // read-only.  But we check for all the relocation types which the
2257 // glibc dynamic linker supports, so it seems appropriate to issue an
2258 // error even if the section is not read-only.  If GSYM is not NULL,
2259 // it is the symbol the relocation is against; if it is NULL, the
2260 // relocation is against a local symbol.
2261
2262 template<int size>
2263 void
2264 Target_x86_64<size>::Scan::check_non_pic(Relobj* object, unsigned int r_type,
2265                                          Symbol* gsym)
2266 {
2267   switch (r_type)
2268     {
2269       // These are the relocation types supported by glibc for x86_64
2270       // which should always work.
2271     case elfcpp::R_X86_64_RELATIVE:
2272     case elfcpp::R_X86_64_IRELATIVE:
2273     case elfcpp::R_X86_64_GLOB_DAT:
2274     case elfcpp::R_X86_64_JUMP_SLOT:
2275     case elfcpp::R_X86_64_DTPMOD64:
2276     case elfcpp::R_X86_64_DTPOFF64:
2277     case elfcpp::R_X86_64_TPOFF64:
2278     case elfcpp::R_X86_64_64:
2279     case elfcpp::R_X86_64_COPY:
2280       return;
2281
2282       // glibc supports these reloc types, but they can overflow.
2283     case elfcpp::R_X86_64_PC32:
2284     case elfcpp::R_X86_64_PC32_BND:
2285       // A PC relative reference is OK against a local symbol or if
2286       // the symbol is defined locally.
2287       if (gsym == NULL
2288           || (!gsym->is_from_dynobj()
2289               && !gsym->is_undefined()
2290               && !gsym->is_preemptible()))
2291         return;
2292       /* Fall through.  */
2293     case elfcpp::R_X86_64_32:
2294       // R_X86_64_32 is OK for x32.
2295       if (size == 32 && r_type == elfcpp::R_X86_64_32)
2296         return;
2297       if (this->issued_non_pic_error_)
2298         return;
2299       gold_assert(parameters->options().output_is_position_independent());
2300       if (gsym == NULL)
2301         object->error(_("requires dynamic R_X86_64_32 reloc which may "
2302                         "overflow at runtime; recompile with -fPIC"));
2303       else
2304         {
2305           const char *r_name;
2306           switch (r_type)
2307             {
2308             case elfcpp::R_X86_64_32:
2309               r_name = "R_X86_64_32";
2310               break;
2311             case elfcpp::R_X86_64_PC32:
2312               r_name = "R_X86_64_PC32";
2313               break;
2314             case elfcpp::R_X86_64_PC32_BND:
2315               r_name = "R_X86_64_PC32_BND";
2316               break;
2317             default:
2318               gold_unreachable();
2319               break;
2320             }
2321           object->error(_("requires dynamic %s reloc against '%s' "
2322                           "which may overflow at runtime; recompile "
2323                           "with -fPIC"),
2324                         r_name, gsym->name());
2325         }
2326       this->issued_non_pic_error_ = true;
2327       return;
2328
2329     default:
2330       // This prevents us from issuing more than one error per reloc
2331       // section.  But we can still wind up issuing more than one
2332       // error per object file.
2333       if (this->issued_non_pic_error_)
2334         return;
2335       gold_assert(parameters->options().output_is_position_independent());
2336       object->error(_("requires unsupported dynamic reloc %u; "
2337                       "recompile with -fPIC"),
2338                     r_type);
2339       this->issued_non_pic_error_ = true;
2340       return;
2341
2342     case elfcpp::R_X86_64_NONE:
2343       gold_unreachable();
2344     }
2345 }
2346
2347 // Return whether we need to make a PLT entry for a relocation of the
2348 // given type against a STT_GNU_IFUNC symbol.
2349
2350 template<int size>
2351 bool
2352 Target_x86_64<size>::Scan::reloc_needs_plt_for_ifunc(
2353      Sized_relobj_file<size, false>* object,
2354      unsigned int r_type)
2355 {
2356   int flags = Scan::get_reference_flags(r_type);
2357   if (flags & Symbol::TLS_REF)
2358     gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
2359                object->name().c_str(), r_type);
2360   return flags != 0;
2361 }
2362
2363 // Scan a relocation for a local symbol.
2364
2365 template<int size>
2366 inline void
2367 Target_x86_64<size>::Scan::local(Symbol_table* symtab,
2368                                  Layout* layout,
2369                                  Target_x86_64<size>* target,
2370                                  Sized_relobj_file<size, false>* object,
2371                                  unsigned int data_shndx,
2372                                  Output_section* output_section,
2373                                  const elfcpp::Rela<size, false>& reloc,
2374                                  unsigned int r_type,
2375                                  const elfcpp::Sym<size, false>& lsym,
2376                                  bool is_discarded)
2377 {
2378   if (is_discarded)
2379     return;
2380
2381   // A local STT_GNU_IFUNC symbol may require a PLT entry.
2382   bool is_ifunc = lsym.get_st_type() == elfcpp::STT_GNU_IFUNC;
2383   if (is_ifunc && this->reloc_needs_plt_for_ifunc(object, r_type))
2384     {
2385       unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2386       target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
2387     }
2388
2389   switch (r_type)
2390     {
2391     case elfcpp::R_X86_64_NONE:
2392     case elfcpp::R_X86_64_GNU_VTINHERIT:
2393     case elfcpp::R_X86_64_GNU_VTENTRY:
2394       break;
2395
2396     case elfcpp::R_X86_64_64:
2397       // If building a shared library (or a position-independent
2398       // executable), we need to create a dynamic relocation for this
2399       // location.  The relocation applied at link time will apply the
2400       // link-time value, so we flag the location with an
2401       // R_X86_64_RELATIVE relocation so the dynamic loader can
2402       // relocate it easily.
2403       if (parameters->options().output_is_position_independent())
2404         {
2405           unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2406           Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2407           rela_dyn->add_local_relative(object, r_sym,
2408                                        (size == 32
2409                                         ? elfcpp::R_X86_64_RELATIVE64
2410                                         : elfcpp::R_X86_64_RELATIVE),
2411                                        output_section, data_shndx,
2412                                        reloc.get_r_offset(),
2413                                        reloc.get_r_addend(), is_ifunc);
2414         }
2415       break;
2416
2417     case elfcpp::R_X86_64_32:
2418     case elfcpp::R_X86_64_32S:
2419     case elfcpp::R_X86_64_16:
2420     case elfcpp::R_X86_64_8:
2421       // If building a shared library (or a position-independent
2422       // executable), we need to create a dynamic relocation for this
2423       // location.  We can't use an R_X86_64_RELATIVE relocation
2424       // because that is always a 64-bit relocation.
2425       if (parameters->options().output_is_position_independent())
2426         {
2427           // Use R_X86_64_RELATIVE relocation for R_X86_64_32 under x32.
2428           if (size == 32 && r_type == elfcpp::R_X86_64_32)
2429             {
2430               unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2431               Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2432               rela_dyn->add_local_relative(object, r_sym,
2433                                            elfcpp::R_X86_64_RELATIVE,
2434                                            output_section, data_shndx,
2435                                            reloc.get_r_offset(),
2436                                            reloc.get_r_addend(), is_ifunc);
2437               break;
2438             }
2439
2440           this->check_non_pic(object, r_type, NULL);
2441
2442           Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2443           unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2444           if (lsym.get_st_type() != elfcpp::STT_SECTION)
2445             rela_dyn->add_local(object, r_sym, r_type, output_section,
2446                                 data_shndx, reloc.get_r_offset(),
2447                                 reloc.get_r_addend());
2448           else
2449             {
2450               gold_assert(lsym.get_st_value() == 0);
2451               unsigned int shndx = lsym.get_st_shndx();
2452               bool is_ordinary;
2453               shndx = object->adjust_sym_shndx(r_sym, shndx,
2454                                                &is_ordinary);
2455               if (!is_ordinary)
2456                 object->error(_("section symbol %u has bad shndx %u"),
2457                               r_sym, shndx);
2458               else
2459                 rela_dyn->add_local_section(object, shndx,
2460                                             r_type, output_section,
2461                                             data_shndx, reloc.get_r_offset(),
2462                                             reloc.get_r_addend());
2463             }
2464         }
2465       break;
2466
2467     case elfcpp::R_X86_64_PC64:
2468     case elfcpp::R_X86_64_PC32:
2469     case elfcpp::R_X86_64_PC32_BND:
2470     case elfcpp::R_X86_64_PC16:
2471     case elfcpp::R_X86_64_PC8:
2472       break;
2473
2474     case elfcpp::R_X86_64_PLT32:
2475     case elfcpp::R_X86_64_PLT32_BND:
2476       // Since we know this is a local symbol, we can handle this as a
2477       // PC32 reloc.
2478       break;
2479
2480     case elfcpp::R_X86_64_GOTPC32:
2481     case elfcpp::R_X86_64_GOTOFF64:
2482     case elfcpp::R_X86_64_GOTPC64:
2483     case elfcpp::R_X86_64_PLTOFF64:
2484       // We need a GOT section.
2485       target->got_section(symtab, layout);
2486       // For PLTOFF64, we'd normally want a PLT section, but since we
2487       // know this is a local symbol, no PLT is needed.
2488       break;
2489
2490     case elfcpp::R_X86_64_GOT64:
2491     case elfcpp::R_X86_64_GOT32:
2492     case elfcpp::R_X86_64_GOTPCREL64:
2493     case elfcpp::R_X86_64_GOTPCREL:
2494     case elfcpp::R_X86_64_GOTPCRELX:
2495     case elfcpp::R_X86_64_REX_GOTPCRELX:
2496     case elfcpp::R_X86_64_GOTPLT64:
2497       {
2498         // The symbol requires a GOT section.
2499         Output_data_got<64, false>* got = target->got_section(symtab, layout);
2500
2501         // If the relocation symbol isn't IFUNC,
2502         // and is local, then we will convert
2503         // mov foo@GOTPCREL(%rip), %reg
2504         // to lea foo(%rip), %reg.
2505         // in Relocate::relocate.
2506         if ((r_type == elfcpp::R_X86_64_GOTPCREL
2507              || r_type == elfcpp::R_X86_64_GOTPCRELX
2508              || r_type == elfcpp::R_X86_64_REX_GOTPCRELX)
2509             && reloc.get_r_offset() >= 2
2510             && !is_ifunc)
2511           {
2512             section_size_type stype;
2513             const unsigned char* view = object->section_contents(data_shndx,
2514                                                                  &stype, true);
2515             if (view[reloc.get_r_offset() - 2] == 0x8b)
2516               break;
2517           }
2518
2519
2520         // The symbol requires a GOT entry.
2521         unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2522
2523         // For a STT_GNU_IFUNC symbol we want the PLT offset.  That
2524         // lets function pointers compare correctly with shared
2525         // libraries.  Otherwise we would need an IRELATIVE reloc.
2526         bool is_new;
2527         if (is_ifunc)
2528           is_new = got->add_local_plt(object, r_sym, GOT_TYPE_STANDARD);
2529         else
2530           is_new = got->add_local(object, r_sym, GOT_TYPE_STANDARD);
2531         if (is_new)
2532           {
2533             // If we are generating a shared object, we need to add a
2534             // dynamic relocation for this symbol's GOT entry.
2535             if (parameters->options().output_is_position_independent())
2536               {
2537                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2538                 // R_X86_64_RELATIVE assumes a 64-bit relocation.
2539                 if (r_type != elfcpp::R_X86_64_GOT32)
2540                   {
2541                     unsigned int got_offset =
2542                       object->local_got_offset(r_sym, GOT_TYPE_STANDARD);
2543                     rela_dyn->add_local_relative(object, r_sym,
2544                                                  elfcpp::R_X86_64_RELATIVE,
2545                                                  got, got_offset, 0, is_ifunc);
2546                   }
2547                 else
2548                   {
2549                     this->check_non_pic(object, r_type, NULL);
2550
2551                     gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
2552                     rela_dyn->add_local(
2553                         object, r_sym, r_type, got,
2554                         object->local_got_offset(r_sym, GOT_TYPE_STANDARD), 0);
2555                   }
2556               }
2557           }
2558         // For GOTPLT64, we'd normally want a PLT section, but since
2559         // we know this is a local symbol, no PLT is needed.
2560       }
2561       break;
2562
2563     case elfcpp::R_X86_64_COPY:
2564     case elfcpp::R_X86_64_GLOB_DAT:
2565     case elfcpp::R_X86_64_JUMP_SLOT:
2566     case elfcpp::R_X86_64_RELATIVE:
2567     case elfcpp::R_X86_64_IRELATIVE:
2568       // These are outstanding tls relocs, which are unexpected when linking
2569     case elfcpp::R_X86_64_TPOFF64:
2570     case elfcpp::R_X86_64_DTPMOD64:
2571     case elfcpp::R_X86_64_TLSDESC:
2572       gold_error(_("%s: unexpected reloc %u in object file"),
2573                  object->name().c_str(), r_type);
2574       break;
2575
2576       // These are initial tls relocs, which are expected when linking
2577     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
2578     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
2579     case elfcpp::R_X86_64_TLSDESC_CALL:
2580     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
2581     case elfcpp::R_X86_64_DTPOFF32:
2582     case elfcpp::R_X86_64_DTPOFF64:
2583     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
2584     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
2585       {
2586         bool output_is_shared = parameters->options().shared();
2587         const tls::Tls_optimization optimized_type
2588             = Target_x86_64<size>::optimize_tls_reloc(!output_is_shared,
2589                                                       r_type);
2590         switch (r_type)
2591           {
2592           case elfcpp::R_X86_64_TLSGD:       // General-dynamic
2593             if (optimized_type == tls::TLSOPT_NONE)
2594               {
2595                 // Create a pair of GOT entries for the module index and
2596                 // dtv-relative offset.
2597                 Output_data_got<64, false>* got
2598                     = target->got_section(symtab, layout);
2599                 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2600                 unsigned int shndx = lsym.get_st_shndx();
2601                 bool is_ordinary;
2602                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
2603                 if (!is_ordinary)
2604                   object->error(_("local symbol %u has bad shndx %u"),
2605                               r_sym, shndx);
2606                 else
2607                   got->add_local_pair_with_rel(object, r_sym,
2608                                                shndx,
2609                                                GOT_TYPE_TLS_PAIR,
2610                                                target->rela_dyn_section(layout),
2611                                                elfcpp::R_X86_64_DTPMOD64);
2612               }
2613             else if (optimized_type != tls::TLSOPT_TO_LE)
2614               unsupported_reloc_local(object, r_type);
2615             break;
2616
2617           case elfcpp::R_X86_64_GOTPC32_TLSDESC:
2618             target->define_tls_base_symbol(symtab, layout);
2619             if (optimized_type == tls::TLSOPT_NONE)
2620               {
2621                 // Create reserved PLT and GOT entries for the resolver.
2622                 target->reserve_tlsdesc_entries(symtab, layout);
2623
2624                 // Generate a double GOT entry with an
2625                 // R_X86_64_TLSDESC reloc.  The R_X86_64_TLSDESC reloc
2626                 // is resolved lazily, so the GOT entry needs to be in
2627                 // an area in .got.plt, not .got.  Call got_section to
2628                 // make sure the section has been created.
2629                 target->got_section(symtab, layout);
2630                 Output_data_got<64, false>* got = target->got_tlsdesc_section();
2631                 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2632                 if (!object->local_has_got_offset(r_sym, GOT_TYPE_TLS_DESC))
2633                   {
2634                     unsigned int got_offset = got->add_constant(0);
2635                     got->add_constant(0);
2636                     object->set_local_got_offset(r_sym, GOT_TYPE_TLS_DESC,
2637                                                  got_offset);
2638                     Reloc_section* rt = target->rela_tlsdesc_section(layout);
2639                     // We store the arguments we need in a vector, and
2640                     // use the index into the vector as the parameter
2641                     // to pass to the target specific routines.
2642                     uintptr_t intarg = target->add_tlsdesc_info(object, r_sym);
2643                     void* arg = reinterpret_cast<void*>(intarg);
2644                     rt->add_target_specific(elfcpp::R_X86_64_TLSDESC, arg,
2645                                             got, got_offset, 0);
2646                   }
2647               }
2648             else if (optimized_type != tls::TLSOPT_TO_LE)
2649               unsupported_reloc_local(object, r_type);
2650             break;
2651
2652           case elfcpp::R_X86_64_TLSDESC_CALL:
2653             break;
2654
2655           case elfcpp::R_X86_64_TLSLD:       // Local-dynamic
2656             if (optimized_type == tls::TLSOPT_NONE)
2657               {
2658                 // Create a GOT entry for the module index.
2659                 target->got_mod_index_entry(symtab, layout, object);
2660               }
2661             else if (optimized_type != tls::TLSOPT_TO_LE)
2662               unsupported_reloc_local(object, r_type);
2663             break;
2664
2665           case elfcpp::R_X86_64_DTPOFF32:
2666           case elfcpp::R_X86_64_DTPOFF64:
2667             break;
2668
2669           case elfcpp::R_X86_64_GOTTPOFF:    // Initial-exec
2670             layout->set_has_static_tls();
2671             if (optimized_type == tls::TLSOPT_NONE)
2672               {
2673                 // Create a GOT entry for the tp-relative offset.
2674                 Output_data_got<64, false>* got
2675                     = target->got_section(symtab, layout);
2676                 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2677                 got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
2678                                         target->rela_dyn_section(layout),
2679                                         elfcpp::R_X86_64_TPOFF64);
2680               }
2681             else if (optimized_type != tls::TLSOPT_TO_LE)
2682               unsupported_reloc_local(object, r_type);
2683             break;
2684
2685           case elfcpp::R_X86_64_TPOFF32:     // Local-exec
2686             layout->set_has_static_tls();
2687             if (output_is_shared)
2688               unsupported_reloc_local(object, r_type);
2689             break;
2690
2691           default:
2692             gold_unreachable();
2693           }
2694       }
2695       break;
2696
2697     case elfcpp::R_X86_64_SIZE32:
2698     case elfcpp::R_X86_64_SIZE64:
2699     default:
2700       gold_error(_("%s: unsupported reloc %u against local symbol"),
2701                  object->name().c_str(), r_type);
2702       break;
2703     }
2704 }
2705
2706
2707 // Report an unsupported relocation against a global symbol.
2708
2709 template<int size>
2710 void
2711 Target_x86_64<size>::Scan::unsupported_reloc_global(
2712     Sized_relobj_file<size, false>* object,
2713     unsigned int r_type,
2714     Symbol* gsym)
2715 {
2716   gold_error(_("%s: unsupported reloc %u against global symbol %s"),
2717              object->name().c_str(), r_type, gsym->demangled_name().c_str());
2718 }
2719
2720 // Returns true if this relocation type could be that of a function pointer.
2721 template<int size>
2722 inline bool
2723 Target_x86_64<size>::Scan::possible_function_pointer_reloc(unsigned int r_type)
2724 {
2725   switch (r_type)
2726     {
2727     case elfcpp::R_X86_64_64:
2728     case elfcpp::R_X86_64_32:
2729     case elfcpp::R_X86_64_32S:
2730     case elfcpp::R_X86_64_16:
2731     case elfcpp::R_X86_64_8:
2732     case elfcpp::R_X86_64_GOT64:
2733     case elfcpp::R_X86_64_GOT32:
2734     case elfcpp::R_X86_64_GOTPCREL64:
2735     case elfcpp::R_X86_64_GOTPCREL:
2736     case elfcpp::R_X86_64_GOTPCRELX:
2737     case elfcpp::R_X86_64_REX_GOTPCRELX:
2738     case elfcpp::R_X86_64_GOTPLT64:
2739       {
2740         return true;
2741       }
2742     }
2743   return false;
2744 }
2745
2746 // For safe ICF, scan a relocation for a local symbol to check if it
2747 // corresponds to a function pointer being taken.  In that case mark
2748 // the function whose pointer was taken as not foldable.
2749
2750 template<int size>
2751 inline bool
2752 Target_x86_64<size>::Scan::local_reloc_may_be_function_pointer(
2753   Symbol_table* ,
2754   Layout* ,
2755   Target_x86_64<size>* ,
2756   Sized_relobj_file<size, false>* ,
2757   unsigned int ,
2758   Output_section* ,
2759   const elfcpp::Rela<size, false>& ,
2760   unsigned int r_type,
2761   const elfcpp::Sym<size, false>&)
2762 {
2763   // When building a shared library, do not fold any local symbols as it is
2764   // not possible to distinguish pointer taken versus a call by looking at
2765   // the relocation types.
2766   return (parameters->options().shared()
2767           || possible_function_pointer_reloc(r_type));
2768 }
2769
2770 // For safe ICF, scan a relocation for a global symbol to check if it
2771 // corresponds to a function pointer being taken.  In that case mark
2772 // the function whose pointer was taken as not foldable.
2773
2774 template<int size>
2775 inline bool
2776 Target_x86_64<size>::Scan::global_reloc_may_be_function_pointer(
2777   Symbol_table*,
2778   Layout* ,
2779   Target_x86_64<size>* ,
2780   Sized_relobj_file<size, false>* ,
2781   unsigned int ,
2782   Output_section* ,
2783   const elfcpp::Rela<size, false>& ,
2784   unsigned int r_type,
2785   Symbol* gsym)
2786 {
2787   // When building a shared library, do not fold symbols whose visibility
2788   // is hidden, internal or protected.
2789   return ((parameters->options().shared()
2790            && (gsym->visibility() == elfcpp::STV_INTERNAL
2791                || gsym->visibility() == elfcpp::STV_PROTECTED
2792                || gsym->visibility() == elfcpp::STV_HIDDEN))
2793           || possible_function_pointer_reloc(r_type));
2794 }
2795
2796 // Scan a relocation for a global symbol.
2797
2798 template<int size>
2799 inline void
2800 Target_x86_64<size>::Scan::global(Symbol_table* symtab,
2801                             Layout* layout,
2802                             Target_x86_64<size>* target,
2803                             Sized_relobj_file<size, false>* object,
2804                             unsigned int data_shndx,
2805                             Output_section* output_section,
2806                             const elfcpp::Rela<size, false>& reloc,
2807                             unsigned int r_type,
2808                             Symbol* gsym)
2809 {
2810   // A STT_GNU_IFUNC symbol may require a PLT entry.
2811   if (gsym->type() == elfcpp::STT_GNU_IFUNC
2812       && this->reloc_needs_plt_for_ifunc(object, r_type))
2813     target->make_plt_entry(symtab, layout, gsym);
2814
2815   switch (r_type)
2816     {
2817     case elfcpp::R_X86_64_NONE:
2818     case elfcpp::R_X86_64_GNU_VTINHERIT:
2819     case elfcpp::R_X86_64_GNU_VTENTRY:
2820       break;
2821
2822     case elfcpp::R_X86_64_64:
2823     case elfcpp::R_X86_64_32:
2824     case elfcpp::R_X86_64_32S:
2825     case elfcpp::R_X86_64_16:
2826     case elfcpp::R_X86_64_8:
2827       {
2828         // Make a PLT entry if necessary.
2829         if (gsym->needs_plt_entry())
2830           {
2831             target->make_plt_entry(symtab, layout, gsym);
2832             // Since this is not a PC-relative relocation, we may be
2833             // taking the address of a function. In that case we need to
2834             // set the entry in the dynamic symbol table to the address of
2835             // the PLT entry.
2836             if (gsym->is_from_dynobj() && !parameters->options().shared())
2837               gsym->set_needs_dynsym_value();
2838           }
2839         // Make a dynamic relocation if necessary.
2840         if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
2841           {
2842             if (!parameters->options().output_is_position_independent()
2843                 && gsym->may_need_copy_reloc())
2844               {
2845                 target->copy_reloc(symtab, layout, object,
2846                                    data_shndx, output_section, gsym, reloc);
2847               }
2848             else if (((size == 64 && r_type == elfcpp::R_X86_64_64)
2849                       || (size == 32 && r_type == elfcpp::R_X86_64_32))
2850                      && gsym->type() == elfcpp::STT_GNU_IFUNC
2851                      && gsym->can_use_relative_reloc(false)
2852                      && !gsym->is_from_dynobj()
2853                      && !gsym->is_undefined()
2854                      && !gsym->is_preemptible())
2855               {
2856                 // Use an IRELATIVE reloc for a locally defined
2857                 // STT_GNU_IFUNC symbol.  This makes a function
2858                 // address in a PIE executable match the address in a
2859                 // shared library that it links against.
2860                 Reloc_section* rela_dyn =
2861                   target->rela_irelative_section(layout);
2862                 unsigned int r_type = elfcpp::R_X86_64_IRELATIVE;
2863                 rela_dyn->add_symbolless_global_addend(gsym, r_type,
2864                                                        output_section, object,
2865                                                        data_shndx,
2866                                                        reloc.get_r_offset(),
2867                                                        reloc.get_r_addend());
2868               }
2869             else if (((size == 64 && r_type == elfcpp::R_X86_64_64)
2870                       || (size == 32 && r_type == elfcpp::R_X86_64_32))
2871                      && gsym->can_use_relative_reloc(false))
2872               {
2873                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2874                 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_RELATIVE,
2875                                               output_section, object,
2876                                               data_shndx,
2877                                               reloc.get_r_offset(),
2878                                               reloc.get_r_addend(), false);
2879               }
2880             else
2881               {
2882                 this->check_non_pic(object, r_type, gsym);
2883                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2884                 rela_dyn->add_global(gsym, r_type, output_section, object,
2885                                      data_shndx, reloc.get_r_offset(),
2886                                      reloc.get_r_addend());
2887               }
2888           }
2889       }
2890       break;
2891
2892     case elfcpp::R_X86_64_PC64:
2893     case elfcpp::R_X86_64_PC32:
2894     case elfcpp::R_X86_64_PC32_BND:
2895     case elfcpp::R_X86_64_PC16:
2896     case elfcpp::R_X86_64_PC8:
2897       {
2898         // Make a PLT entry if necessary.
2899         if (gsym->needs_plt_entry())
2900           target->make_plt_entry(symtab, layout, gsym);
2901         // Make a dynamic relocation if necessary.
2902         if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
2903           {
2904             if (parameters->options().output_is_executable()
2905                 && gsym->may_need_copy_reloc())
2906               {
2907                 target->copy_reloc(symtab, layout, object,
2908                                    data_shndx, output_section, gsym, reloc);
2909               }
2910             else
2911               {
2912                 this->check_non_pic(object, r_type, gsym);
2913                 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2914                 rela_dyn->add_global(gsym, r_type, output_section, object,
2915                                      data_shndx, reloc.get_r_offset(),
2916                                      reloc.get_r_addend());
2917               }
2918           }
2919       }
2920       break;
2921
2922     case elfcpp::R_X86_64_GOT64:
2923     case elfcpp::R_X86_64_GOT32:
2924     case elfcpp::R_X86_64_GOTPCREL64:
2925     case elfcpp::R_X86_64_GOTPCREL:
2926     case elfcpp::R_X86_64_GOTPCRELX:
2927     case elfcpp::R_X86_64_REX_GOTPCRELX:
2928     case elfcpp::R_X86_64_GOTPLT64:
2929       {
2930         // The symbol requires a GOT entry.
2931         Output_data_got<64, false>* got = target->got_section(symtab, layout);
2932
2933         // If we convert this from
2934         // mov foo@GOTPCREL(%rip), %reg
2935         // to lea foo(%rip), %reg.
2936         // in Relocate::relocate, then there is nothing to do here.
2937         if ((r_type == elfcpp::R_X86_64_GOTPCREL
2938              || r_type == elfcpp::R_X86_64_GOTPCRELX
2939              || r_type == elfcpp::R_X86_64_REX_GOTPCRELX)
2940             && reloc.get_r_offset() >= 2
2941             && Target_x86_64<size>::can_convert_mov_to_lea(gsym))
2942           {
2943             section_size_type stype;
2944             const unsigned char* view = object->section_contents(data_shndx,
2945                                                                  &stype, true);
2946             if (view[reloc.get_r_offset() - 2] == 0x8b)
2947               break;
2948           }
2949
2950         if (gsym->final_value_is_known())
2951           {
2952             // For a STT_GNU_IFUNC symbol we want the PLT address.
2953             if (gsym->type() == elfcpp::STT_GNU_IFUNC)
2954               got->add_global_plt(gsym, GOT_TYPE_STANDARD);
2955             else
2956               got->add_global(gsym, GOT_TYPE_STANDARD);
2957           }
2958         else
2959           {
2960             // If this symbol is not fully resolved, we need to add a
2961             // dynamic relocation for it.
2962             Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2963
2964             // Use a GLOB_DAT rather than a RELATIVE reloc if:
2965             //
2966             // 1) The symbol may be defined in some other module.
2967             //
2968             // 2) We are building a shared library and this is a
2969             // protected symbol; using GLOB_DAT means that the dynamic
2970             // linker can use the address of the PLT in the main
2971             // executable when appropriate so that function address
2972             // comparisons work.
2973             //
2974             // 3) This is a STT_GNU_IFUNC symbol in position dependent
2975             // code, again so that function address comparisons work.
2976             if (gsym->is_from_dynobj()
2977                 || gsym->is_undefined()
2978                 || gsym->is_preemptible()
2979                 || (gsym->visibility() == elfcpp::STV_PROTECTED
2980                     && parameters->options().shared())
2981                 || (gsym->type() == elfcpp::STT_GNU_IFUNC
2982                     && parameters->options().output_is_position_independent()))
2983               got->add_global_with_rel(gsym, GOT_TYPE_STANDARD, rela_dyn,
2984                                        elfcpp::R_X86_64_GLOB_DAT);
2985             else
2986               {
2987                 // For a STT_GNU_IFUNC symbol we want to write the PLT
2988                 // offset into the GOT, so that function pointer
2989                 // comparisons work correctly.
2990                 bool is_new;
2991                 if (gsym->type() != elfcpp::STT_GNU_IFUNC)
2992                   is_new = got->add_global(gsym, GOT_TYPE_STANDARD);
2993                 else
2994                   {
2995                     is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD);
2996                     // Tell the dynamic linker to use the PLT address
2997                     // when resolving relocations.
2998                     if (gsym->is_from_dynobj()
2999                         && !parameters->options().shared())
3000                       gsym->set_needs_dynsym_value();
3001                   }
3002                 if (is_new)
3003                   {
3004                     unsigned int got_off = gsym->got_offset(GOT_TYPE_STANDARD);
3005                     rela_dyn->add_global_relative(gsym,
3006                                                   elfcpp::R_X86_64_RELATIVE,
3007                                                   got, got_off, 0, false);
3008                   }
3009               }
3010           }
3011       }
3012       break;
3013
3014     case elfcpp::R_X86_64_PLT32:
3015     case elfcpp::R_X86_64_PLT32_BND:
3016       // If the symbol is fully resolved, this is just a PC32 reloc.
3017       // Otherwise we need a PLT entry.
3018       if (gsym->final_value_is_known())
3019         break;
3020       // If building a shared library, we can also skip the PLT entry
3021       // if the symbol is defined in the output file and is protected
3022       // or hidden.
3023       if (gsym->is_defined()
3024           && !gsym->is_from_dynobj()
3025           && !gsym->is_preemptible())
3026         break;
3027       target->make_plt_entry(symtab, layout, gsym);
3028       break;
3029
3030     case elfcpp::R_X86_64_GOTPC32:
3031     case elfcpp::R_X86_64_GOTOFF64:
3032     case elfcpp::R_X86_64_GOTPC64:
3033     case elfcpp::R_X86_64_PLTOFF64:
3034       // We need a GOT section.
3035       target->got_section(symtab, layout);
3036       // For PLTOFF64, we also need a PLT entry (but only if the
3037       // symbol is not fully resolved).
3038       if (r_type == elfcpp::R_X86_64_PLTOFF64
3039           && !gsym->final_value_is_known())
3040         target->make_plt_entry(symtab, layout, gsym);
3041       break;
3042
3043     case elfcpp::R_X86_64_COPY:
3044     case elfcpp::R_X86_64_GLOB_DAT:
3045     case elfcpp::R_X86_64_JUMP_SLOT:
3046     case elfcpp::R_X86_64_RELATIVE:
3047     case elfcpp::R_X86_64_IRELATIVE:
3048       // These are outstanding tls relocs, which are unexpected when linking
3049     case elfcpp::R_X86_64_TPOFF64:
3050     case elfcpp::R_X86_64_DTPMOD64:
3051     case elfcpp::R_X86_64_TLSDESC:
3052       gold_error(_("%s: unexpected reloc %u in object file"),
3053                  object->name().c_str(), r_type);
3054       break;
3055
3056       // These are initial tls relocs, which are expected for global()
3057     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
3058     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
3059     case elfcpp::R_X86_64_TLSDESC_CALL:
3060     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
3061     case elfcpp::R_X86_64_DTPOFF32:
3062     case elfcpp::R_X86_64_DTPOFF64:
3063     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
3064     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
3065       {
3066         // For the Initial-Exec model, we can treat undef symbols as final
3067         // when building an executable.
3068         const bool is_final = (gsym->final_value_is_known() ||
3069                                (r_type == elfcpp::R_X86_64_GOTTPOFF &&
3070                                 gsym->is_undefined() &&
3071                                 parameters->options().output_is_executable()));
3072         const tls::Tls_optimization optimized_type
3073             = Target_x86_64<size>::optimize_tls_reloc(is_final, r_type);
3074         switch (r_type)
3075           {
3076           case elfcpp::R_X86_64_TLSGD:       // General-dynamic
3077             if (optimized_type == tls::TLSOPT_NONE)
3078               {
3079                 // Create a pair of GOT entries for the module index and
3080                 // dtv-relative offset.
3081                 Output_data_got<64, false>* got
3082                     = target->got_section(symtab, layout);
3083                 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
3084                                               target->rela_dyn_section(layout),
3085                                               elfcpp::R_X86_64_DTPMOD64,
3086                                               elfcpp::R_X86_64_DTPOFF64);
3087               }
3088             else if (optimized_type == tls::TLSOPT_TO_IE)
3089               {
3090                 // Create a GOT entry for the tp-relative offset.
3091                 Output_data_got<64, false>* got
3092                     = target->got_section(symtab, layout);
3093                 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
3094                                          target->rela_dyn_section(layout),
3095                                          elfcpp::R_X86_64_TPOFF64);
3096               }
3097             else if (optimized_type != tls::TLSOPT_TO_LE)
3098               unsupported_reloc_global(object, r_type, gsym);
3099             break;
3100
3101           case elfcpp::R_X86_64_GOTPC32_TLSDESC:
3102             target->define_tls_base_symbol(symtab, layout);
3103             if (optimized_type == tls::TLSOPT_NONE)
3104               {
3105                 // Create reserved PLT and GOT entries for the resolver.
3106                 target->reserve_tlsdesc_entries(symtab, layout);
3107
3108                 // Create a double GOT entry with an R_X86_64_TLSDESC
3109                 // reloc.  The R_X86_64_TLSDESC reloc is resolved
3110                 // lazily, so the GOT entry needs to be in an area in
3111                 // .got.plt, not .got.  Call got_section to make sure
3112                 // the section has been created.
3113                 target->got_section(symtab, layout);
3114                 Output_data_got<64, false>* got = target->got_tlsdesc_section();
3115                 Reloc_section* rt = target->rela_tlsdesc_section(layout);
3116                 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC, rt,
3117                                               elfcpp::R_X86_64_TLSDESC, 0);
3118               }
3119             else if (optimized_type == tls::TLSOPT_TO_IE)
3120               {
3121                 // Create a GOT entry for the tp-relative offset.
3122                 Output_data_got<64, false>* got
3123                     = target->got_section(symtab, layout);
3124                 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
3125                                          target->rela_dyn_section(layout),
3126                                          elfcpp::R_X86_64_TPOFF64);
3127               }
3128             else if (optimized_type != tls::TLSOPT_TO_LE)
3129               unsupported_reloc_global(object, r_type, gsym);
3130             break;
3131
3132           case elfcpp::R_X86_64_TLSDESC_CALL:
3133             break;
3134
3135           case elfcpp::R_X86_64_TLSLD:       // Local-dynamic
3136             if (optimized_type == tls::TLSOPT_NONE)
3137               {
3138                 // Create a GOT entry for the module index.
3139                 target->got_mod_index_entry(symtab, layout, object);
3140               }
3141             else if (optimized_type != tls::TLSOPT_TO_LE)
3142               unsupported_reloc_global(object, r_type, gsym);
3143             break;
3144
3145           case elfcpp::R_X86_64_DTPOFF32:
3146           case elfcpp::R_X86_64_DTPOFF64:
3147             break;
3148
3149           case elfcpp::R_X86_64_GOTTPOFF:    // Initial-exec
3150             layout->set_has_static_tls();
3151             if (optimized_type == tls::TLSOPT_NONE)
3152               {
3153                 // Create a GOT entry for the tp-relative offset.
3154                 Output_data_got<64, false>* got
3155                     = target->got_section(symtab, layout);
3156                 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
3157                                          target->rela_dyn_section(layout),
3158                                          elfcpp::R_X86_64_TPOFF64);
3159               }
3160             else if (optimized_type != tls::TLSOPT_TO_LE)
3161               unsupported_reloc_global(object, r_type, gsym);
3162             break;
3163
3164           case elfcpp::R_X86_64_TPOFF32:     // Local-exec
3165             layout->set_has_static_tls();
3166             if (parameters->options().shared())
3167               unsupported_reloc_global(object, r_type, gsym);
3168             break;
3169
3170           default:
3171             gold_unreachable();
3172           }
3173       }
3174       break;
3175
3176     case elfcpp::R_X86_64_SIZE32:
3177     case elfcpp::R_X86_64_SIZE64:
3178     default:
3179       gold_error(_("%s: unsupported reloc %u against global symbol %s"),
3180                  object->name().c_str(), r_type,
3181                  gsym->demangled_name().c_str());
3182       break;
3183     }
3184 }
3185
3186 template<int size>
3187 void
3188 Target_x86_64<size>::gc_process_relocs(Symbol_table* symtab,
3189                                        Layout* layout,
3190                                        Sized_relobj_file<size, false>* object,
3191                                        unsigned int data_shndx,
3192                                        unsigned int sh_type,
3193                                        const unsigned char* prelocs,
3194                                        size_t reloc_count,
3195                                        Output_section* output_section,
3196                                        bool needs_special_offset_handling,
3197                                        size_t local_symbol_count,
3198                                        const unsigned char* plocal_symbols)
3199 {
3200   typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
3201       Classify_reloc;
3202
3203   if (sh_type == elfcpp::SHT_REL)
3204     {
3205       return;
3206     }
3207
3208    gold::gc_process_relocs<size, false, Target_x86_64<size>, Scan,
3209                            Classify_reloc>(
3210     symtab,
3211     layout,
3212     this,
3213     object,
3214     data_shndx,
3215     prelocs,
3216     reloc_count,
3217     output_section,
3218     needs_special_offset_handling,
3219     local_symbol_count,
3220     plocal_symbols);
3221
3222 }
3223 // Scan relocations for a section.
3224
3225 template<int size>
3226 void
3227 Target_x86_64<size>::scan_relocs(Symbol_table* symtab,
3228                                  Layout* layout,
3229                                  Sized_relobj_file<size, false>* object,
3230                                  unsigned int data_shndx,
3231                                  unsigned int sh_type,
3232                                  const unsigned char* prelocs,
3233                                  size_t reloc_count,
3234                                  Output_section* output_section,
3235                                  bool needs_special_offset_handling,
3236                                  size_t local_symbol_count,
3237                                  const unsigned char* plocal_symbols)
3238 {
3239   typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
3240       Classify_reloc;
3241
3242   if (sh_type == elfcpp::SHT_REL)
3243     {
3244       gold_error(_("%s: unsupported REL reloc section"),
3245                  object->name().c_str());
3246       return;
3247     }
3248
3249   gold::scan_relocs<size, false, Target_x86_64<size>, Scan, Classify_reloc>(
3250     symtab,
3251     layout,
3252     this,
3253     object,
3254     data_shndx,
3255     prelocs,
3256     reloc_count,
3257     output_section,
3258     needs_special_offset_handling,
3259     local_symbol_count,
3260     plocal_symbols);
3261 }
3262
3263 // Finalize the sections.
3264
3265 template<int size>
3266 void
3267 Target_x86_64<size>::do_finalize_sections(
3268     Layout* layout,
3269     const Input_objects*,
3270     Symbol_table* symtab)
3271 {
3272   const Reloc_section* rel_plt = (this->plt_ == NULL
3273                                   ? NULL
3274                                   : this->plt_->rela_plt());
3275   layout->add_target_dynamic_tags(false, this->got_plt_, rel_plt,
3276                                   this->rela_dyn_, true, false);
3277
3278   // Fill in some more dynamic tags.
3279   Output_data_dynamic* const odyn = layout->dynamic_data();
3280   if (odyn != NULL)
3281     {
3282       if (this->plt_ != NULL
3283           && this->plt_->output_section() != NULL
3284           && this->plt_->has_tlsdesc_entry())
3285         {
3286           unsigned int plt_offset = this->plt_->get_tlsdesc_plt_offset();
3287           unsigned int got_offset = this->plt_->get_tlsdesc_got_offset();
3288           this->got_->finalize_data_size();
3289           odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_PLT,
3290                                         this->plt_, plt_offset);
3291           odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_GOT,
3292                                         this->got_, got_offset);
3293         }
3294     }
3295
3296   // Emit any relocs we saved in an attempt to avoid generating COPY
3297   // relocs.
3298   if (this->copy_relocs_.any_saved_relocs())
3299     this->copy_relocs_.emit(this->rela_dyn_section(layout));
3300
3301   // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
3302   // the .got.plt section.
3303   Symbol* sym = this->global_offset_table_;
3304   if (sym != NULL)
3305     {
3306       uint64_t data_size = this->got_plt_->current_data_size();
3307       symtab->get_sized_symbol<size>(sym)->set_symsize(data_size);
3308     }
3309
3310   if (parameters->doing_static_link()
3311       && (this->plt_ == NULL || !this->plt_->has_irelative_section()))
3312     {
3313       // If linking statically, make sure that the __rela_iplt symbols
3314       // were defined if necessary, even if we didn't create a PLT.
3315       static const Define_symbol_in_segment syms[] =
3316         {
3317           {
3318             "__rela_iplt_start",        // name
3319             elfcpp::PT_LOAD,            // segment_type
3320             elfcpp::PF_W,               // segment_flags_set
3321             elfcpp::PF(0),              // segment_flags_clear
3322             0,                          // value
3323             0,                          // size
3324             elfcpp::STT_NOTYPE,         // type
3325             elfcpp::STB_GLOBAL,         // binding
3326             elfcpp::STV_HIDDEN,         // visibility
3327             0,                          // nonvis
3328             Symbol::SEGMENT_START,      // offset_from_base
3329             true                        // only_if_ref
3330           },
3331           {
3332             "__rela_iplt_end",          // name
3333             elfcpp::PT_LOAD,            // segment_type
3334             elfcpp::PF_W,               // segment_flags_set
3335             elfcpp::PF(0),              // segment_flags_clear
3336             0,                          // value
3337             0,                          // size
3338             elfcpp::STT_NOTYPE,         // type
3339             elfcpp::STB_GLOBAL,         // binding
3340             elfcpp::STV_HIDDEN,         // visibility
3341             0,                          // nonvis
3342             Symbol::SEGMENT_START,      // offset_from_base
3343             true                        // only_if_ref
3344           }
3345         };
3346
3347       symtab->define_symbols(layout, 2, syms,
3348                              layout->script_options()->saw_sections_clause());
3349     }
3350 }
3351
3352 // Perform a relocation.
3353
3354 template<int size>
3355 inline bool
3356 Target_x86_64<size>::Relocate::relocate(
3357     const Relocate_info<size, false>* relinfo,
3358     unsigned int,
3359     Target_x86_64<size>* target,
3360     Output_section*,
3361     size_t relnum,
3362     const unsigned char* preloc,
3363     const Sized_symbol<size>* gsym,
3364     const Symbol_value<size>* psymval,
3365     unsigned char* view,
3366     typename elfcpp::Elf_types<size>::Elf_Addr address,
3367     section_size_type view_size)
3368 {
3369   const elfcpp::Rela<size, false> rela(preloc);
3370   unsigned int r_type = elfcpp::elf_r_type<size>(rela.get_r_info());
3371
3372   if (this->skip_call_tls_get_addr_)
3373     {
3374       if ((r_type != elfcpp::R_X86_64_PLT32
3375            && r_type != elfcpp::R_X86_64_PLT32_BND
3376            && r_type != elfcpp::R_X86_64_PC32_BND
3377            && r_type != elfcpp::R_X86_64_PC32)
3378           || gsym == NULL
3379           || strcmp(gsym->name(), "__tls_get_addr") != 0)
3380         {
3381           gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3382                                  _("missing expected TLS relocation"));
3383         }
3384       else
3385         {
3386           this->skip_call_tls_get_addr_ = false;
3387           return false;
3388         }
3389     }
3390
3391   if (view == NULL)
3392     return true;
3393
3394   const Sized_relobj_file<size, false>* object = relinfo->object;
3395
3396   // Pick the value to use for symbols defined in the PLT.
3397   Symbol_value<size> symval;
3398   if (gsym != NULL
3399       && gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
3400     {
3401       symval.set_output_value(target->plt_address_for_global(gsym));
3402       psymval = &symval;
3403     }
3404   else if (gsym == NULL && psymval->is_ifunc_symbol())
3405     {
3406       unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3407       if (object->local_has_plt_offset(r_sym))
3408         {
3409           symval.set_output_value(target->plt_address_for_local(object, r_sym));
3410           psymval = &symval;
3411         }
3412     }
3413
3414   const elfcpp::Elf_Xword addend = rela.get_r_addend();
3415
3416   // Get the GOT offset if needed.
3417   // The GOT pointer points to the end of the GOT section.
3418   // We need to subtract the size of the GOT section to get
3419   // the actual offset to use in the relocation.
3420   bool have_got_offset = false;
3421   // Since the actual offset is always negative, we use signed int to
3422   // support 64-bit GOT relocations.
3423   int got_offset = 0;
3424   switch (r_type)
3425     {
3426     case elfcpp::R_X86_64_GOT32:
3427     case elfcpp::R_X86_64_GOT64:
3428     case elfcpp::R_X86_64_GOTPLT64:
3429     case elfcpp::R_X86_64_GOTPCREL64:
3430       if (gsym != NULL)
3431         {
3432           gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
3433           got_offset = gsym->got_offset(GOT_TYPE_STANDARD) - target->got_size();
3434         }
3435       else
3436         {
3437           unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3438           gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
3439           got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
3440                         - target->got_size());
3441         }
3442       have_got_offset = true;
3443       break;
3444
3445     default:
3446       break;
3447     }
3448
3449   switch (r_type)
3450     {
3451     case elfcpp::R_X86_64_NONE:
3452     case elfcpp::R_X86_64_GNU_VTINHERIT:
3453     case elfcpp::R_X86_64_GNU_VTENTRY:
3454       break;
3455
3456     case elfcpp::R_X86_64_64:
3457       Relocate_functions<size, false>::rela64(view, object, psymval, addend);
3458       break;
3459
3460     case elfcpp::R_X86_64_PC64:
3461       Relocate_functions<size, false>::pcrela64(view, object, psymval, addend,
3462                                               address);
3463       break;
3464
3465     case elfcpp::R_X86_64_32:
3466       // FIXME: we need to verify that value + addend fits into 32 bits:
3467       //    uint64_t x = value + addend;
3468       //    x == static_cast<uint64_t>(static_cast<uint32_t>(x))
3469       // Likewise for other <=32-bit relocations (but see R_X86_64_32S).
3470       Relocate_functions<size, false>::rela32(view, object, psymval, addend);
3471       break;
3472
3473     case elfcpp::R_X86_64_32S:
3474       // FIXME: we need to verify that value + addend fits into 32 bits:
3475       //    int64_t x = value + addend;   // note this quantity is signed!
3476       //    x == static_cast<int64_t>(static_cast<int32_t>(x))
3477       Relocate_functions<size, false>::rela32(view, object, psymval, addend);
3478       break;
3479
3480     case elfcpp::R_X86_64_PC32:
3481     case elfcpp::R_X86_64_PC32_BND:
3482       Relocate_functions<size, false>::pcrela32(view, object, psymval, addend,
3483                                                 address);
3484       break;
3485
3486     case elfcpp::R_X86_64_16:
3487       Relocate_functions<size, false>::rela16(view, object, psymval, addend);
3488       break;
3489
3490     case elfcpp::R_X86_64_PC16:
3491       Relocate_functions<size, false>::pcrela16(view, object, psymval, addend,
3492                                                 address);
3493       break;
3494
3495     case elfcpp::R_X86_64_8:
3496       Relocate_functions<size, false>::rela8(view, object, psymval, addend);
3497       break;
3498
3499     case elfcpp::R_X86_64_PC8:
3500       Relocate_functions<size, false>::pcrela8(view, object, psymval, addend,
3501                                                address);
3502       break;
3503
3504     case elfcpp::R_X86_64_PLT32:
3505     case elfcpp::R_X86_64_PLT32_BND:
3506       gold_assert(gsym == NULL
3507                   || gsym->has_plt_offset()
3508                   || gsym->final_value_is_known()
3509                   || (gsym->is_defined()
3510                       && !gsym->is_from_dynobj()
3511                       && !gsym->is_preemptible()));
3512       // Note: while this code looks the same as for R_X86_64_PC32, it
3513       // behaves differently because psymval was set to point to
3514       // the PLT entry, rather than the symbol, in Scan::global().
3515       Relocate_functions<size, false>::pcrela32(view, object, psymval, addend,
3516                                                 address);
3517       break;
3518
3519     case elfcpp::R_X86_64_PLTOFF64:
3520       {
3521         gold_assert(gsym);
3522         gold_assert(gsym->has_plt_offset()
3523                     || gsym->final_value_is_known());
3524         typename elfcpp::Elf_types<size>::Elf_Addr got_address;
3525         // This is the address of GLOBAL_OFFSET_TABLE.
3526         got_address = target->got_plt_section()->address();
3527         Relocate_functions<size, false>::rela64(view, object, psymval,
3528                                                 addend - got_address);
3529       }
3530       break;
3531
3532     case elfcpp::R_X86_64_GOT32:
3533       gold_assert(have_got_offset);
3534       Relocate_functions<size, false>::rela32(view, got_offset, addend);
3535       break;
3536
3537     case elfcpp::R_X86_64_GOTPC32:
3538       {
3539         gold_assert(gsym);
3540         typename elfcpp::Elf_types<size>::Elf_Addr value;
3541         value = target->got_plt_section()->address();
3542         Relocate_functions<size, false>::pcrela32(view, value, addend, address);
3543       }
3544       break;
3545
3546     case elfcpp::R_X86_64_GOT64:
3547     case elfcpp::R_X86_64_GOTPLT64:
3548       // R_X86_64_GOTPLT64 is obsolete and treated the the same as
3549       // GOT64.
3550       gold_assert(have_got_offset);
3551       Relocate_functions<size, false>::rela64(view, got_offset, addend);
3552       break;
3553
3554     case elfcpp::R_X86_64_GOTPC64:
3555       {
3556         gold_assert(gsym);
3557         typename elfcpp::Elf_types<size>::Elf_Addr value;
3558         value = target->got_plt_section()->address();
3559         Relocate_functions<size, false>::pcrela64(view, value, addend, address);
3560       }
3561       break;
3562
3563     case elfcpp::R_X86_64_GOTOFF64:
3564       {
3565         typename elfcpp::Elf_types<size>::Elf_Addr value;
3566         value = (psymval->value(object, 0)
3567                  - target->got_plt_section()->address());
3568         Relocate_functions<size, false>::rela64(view, value, addend);
3569       }
3570       break;
3571
3572     case elfcpp::R_X86_64_GOTPCREL:
3573     case elfcpp::R_X86_64_GOTPCRELX:
3574     case elfcpp::R_X86_64_REX_GOTPCRELX:
3575       {
3576       // Convert
3577       // mov foo@GOTPCREL(%rip), %reg
3578       // to lea foo(%rip), %reg.
3579       // if possible.
3580       if (rela.get_r_offset() >= 2
3581           && view[-2] == 0x8b
3582           && ((gsym == NULL && !psymval->is_ifunc_symbol())
3583               || (gsym != NULL
3584                   && Target_x86_64<size>::can_convert_mov_to_lea(gsym))))
3585         {
3586           view[-2] = 0x8d;
3587           Relocate_functions<size, false>::pcrela32(view, object, psymval, addend,
3588                                                     address);
3589         }
3590       else
3591         {
3592           if (gsym != NULL)
3593             {
3594               gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
3595               got_offset = gsym->got_offset(GOT_TYPE_STANDARD) - target->got_size();
3596             }
3597           else
3598             {
3599               unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3600               gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
3601               got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
3602                             - target->got_size());
3603             }
3604           typename elfcpp::Elf_types<size>::Elf_Addr value;
3605           value = target->got_plt_section()->address() + got_offset;
3606           Relocate_functions<size, false>::pcrela32(view, value, addend, address);
3607         }
3608       }
3609       break;
3610
3611     case elfcpp::R_X86_64_GOTPCREL64:
3612       {
3613         gold_assert(have_got_offset);
3614         typename elfcpp::Elf_types<size>::Elf_Addr value;
3615         value = target->got_plt_section()->address() + got_offset;
3616         Relocate_functions<size, false>::pcrela64(view, value, addend, address);
3617       }
3618       break;
3619
3620     case elfcpp::R_X86_64_COPY:
3621     case elfcpp::R_X86_64_GLOB_DAT:
3622     case elfcpp::R_X86_64_JUMP_SLOT:
3623     case elfcpp::R_X86_64_RELATIVE:
3624     case elfcpp::R_X86_64_IRELATIVE:
3625       // These are outstanding tls relocs, which are unexpected when linking
3626     case elfcpp::R_X86_64_TPOFF64:
3627     case elfcpp::R_X86_64_DTPMOD64:
3628     case elfcpp::R_X86_64_TLSDESC:
3629       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3630                              _("unexpected reloc %u in object file"),
3631                              r_type);
3632       break;
3633
3634       // These are initial tls relocs, which are expected when linking
3635     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
3636     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
3637     case elfcpp::R_X86_64_TLSDESC_CALL:
3638     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
3639     case elfcpp::R_X86_64_DTPOFF32:
3640     case elfcpp::R_X86_64_DTPOFF64:
3641     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
3642     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
3643       this->relocate_tls(relinfo, target, relnum, rela, r_type, gsym, psymval,
3644                          view, address, view_size);
3645       break;
3646
3647     case elfcpp::R_X86_64_SIZE32:
3648     case elfcpp::R_X86_64_SIZE64:
3649     default:
3650       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3651                              _("unsupported reloc %u"),
3652                              r_type);
3653       break;
3654     }
3655
3656   return true;
3657 }
3658
3659 // Perform a TLS relocation.
3660
3661 template<int size>
3662 inline void
3663 Target_x86_64<size>::Relocate::relocate_tls(
3664     const Relocate_info<size, false>* relinfo,
3665     Target_x86_64<size>* target,
3666     size_t relnum,
3667     const elfcpp::Rela<size, false>& rela,
3668     unsigned int r_type,
3669     const Sized_symbol<size>* gsym,
3670     const Symbol_value<size>* psymval,
3671     unsigned char* view,
3672     typename elfcpp::Elf_types<size>::Elf_Addr address,
3673     section_size_type view_size)
3674 {
3675   Output_segment* tls_segment = relinfo->layout->tls_segment();
3676
3677   const Sized_relobj_file<size, false>* object = relinfo->object;
3678   const elfcpp::Elf_Xword addend = rela.get_r_addend();
3679   elfcpp::Shdr<size, false> data_shdr(relinfo->data_shdr);
3680   bool is_executable = (data_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0;
3681
3682   typename elfcpp::Elf_types<size>::Elf_Addr value = psymval->value(relinfo->object, 0);
3683
3684   const bool is_final = (gsym == NULL
3685                          ? !parameters->options().shared()
3686                          : gsym->final_value_is_known());
3687   tls::Tls_optimization optimized_type
3688       = Target_x86_64<size>::optimize_tls_reloc(is_final, r_type);
3689   switch (r_type)
3690     {
3691     case elfcpp::R_X86_64_TLSGD:            // Global-dynamic
3692       if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
3693         {
3694           // If this code sequence is used in a non-executable section,
3695           // we will not optimize the R_X86_64_DTPOFF32/64 relocation,
3696           // on the assumption that it's being used by itself in a debug
3697           // section.  Therefore, in the unlikely event that the code
3698           // sequence appears in a non-executable section, we simply
3699           // leave it unoptimized.
3700           optimized_type = tls::TLSOPT_NONE;
3701         }
3702       if (optimized_type == tls::TLSOPT_TO_LE)
3703         {
3704           if (tls_segment == NULL)
3705             {
3706               gold_assert(parameters->errors()->error_count() > 0
3707                           || issue_undefined_symbol_error(gsym));
3708               return;
3709             }
3710           this->tls_gd_to_le(relinfo, relnum, tls_segment,
3711                              rela, r_type, value, view,
3712                              view_size);
3713           break;
3714         }
3715       else
3716         {
3717           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
3718                                    ? GOT_TYPE_TLS_OFFSET
3719                                    : GOT_TYPE_TLS_PAIR);
3720           unsigned int got_offset;
3721           if (gsym != NULL)
3722             {
3723               gold_assert(gsym->has_got_offset(got_type));
3724               got_offset = gsym->got_offset(got_type) - target->got_size();
3725             }
3726           else
3727             {
3728               unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3729               gold_assert(object->local_has_got_offset(r_sym, got_type));
3730               got_offset = (object->local_got_offset(r_sym, got_type)
3731                             - target->got_size());
3732             }
3733           if (optimized_type == tls::TLSOPT_TO_IE)
3734             {
3735               value = target->got_plt_section()->address() + got_offset;
3736               this->tls_gd_to_ie(relinfo, relnum, tls_segment, rela, r_type,
3737                                  value, view, address, view_size);
3738               break;
3739             }
3740           else if (optimized_type == tls::TLSOPT_NONE)
3741             {
3742               // Relocate the field with the offset of the pair of GOT
3743               // entries.
3744               value = target->got_plt_section()->address() + got_offset;
3745               Relocate_functions<size, false>::pcrela32(view, value, addend,
3746                                                         address);
3747               break;
3748             }
3749         }
3750       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3751                              _("unsupported reloc %u"), r_type);
3752       break;
3753
3754     case elfcpp::R_X86_64_GOTPC32_TLSDESC:  // Global-dynamic (from ~oliva url)
3755     case elfcpp::R_X86_64_TLSDESC_CALL:
3756       if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
3757         {
3758           // See above comment for R_X86_64_TLSGD.
3759           optimized_type = tls::TLSOPT_NONE;
3760         }
3761       if (optimized_type == tls::TLSOPT_TO_LE)
3762         {
3763           if (tls_segment == NULL)
3764             {
3765               gold_assert(parameters->errors()->error_count() > 0
3766                           || issue_undefined_symbol_error(gsym));
3767               return;
3768             }
3769           this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
3770                                   rela, r_type, value, view,
3771                                   view_size);
3772           break;
3773         }
3774       else
3775         {
3776           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
3777                                    ? GOT_TYPE_TLS_OFFSET
3778                                    : GOT_TYPE_TLS_DESC);
3779           unsigned int got_offset = 0;
3780           if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC
3781               && optimized_type == tls::TLSOPT_NONE)
3782             {
3783               // We created GOT entries in the .got.tlsdesc portion of
3784               // the .got.plt section, but the offset stored in the
3785               // symbol is the offset within .got.tlsdesc.
3786               got_offset = (target->got_size()
3787                             + target->got_plt_section()->data_size());
3788             }
3789           if (gsym != NULL)
3790             {
3791               gold_assert(gsym->has_got_offset(got_type));
3792               got_offset += gsym->got_offset(got_type) - target->got_size();
3793             }
3794           else
3795             {
3796               unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3797               gold_assert(object->local_has_got_offset(r_sym, got_type));
3798               got_offset += (object->local_got_offset(r_sym, got_type)
3799                              - target->got_size());
3800             }
3801           if (optimized_type == tls::TLSOPT_TO_IE)
3802             {
3803               if (tls_segment == NULL)
3804                 {
3805                   gold_assert(parameters->errors()->error_count() > 0
3806                               || issue_undefined_symbol_error(gsym));
3807                   return;
3808                 }
3809               value = target->got_plt_section()->address() + got_offset;
3810               this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment,
3811                                       rela, r_type, value, view, address,
3812                                       view_size);
3813               break;
3814             }
3815           else if (optimized_type == tls::TLSOPT_NONE)
3816             {
3817               if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
3818                 {
3819                   // Relocate the field with the offset of the pair of GOT
3820                   // entries.
3821                   value = target->got_plt_section()->address() + got_offset;
3822                   Relocate_functions<size, false>::pcrela32(view, value, addend,
3823                                                             address);
3824                 }
3825               break;
3826             }
3827         }
3828       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3829                              _("unsupported reloc %u"), r_type);
3830       break;
3831
3832     case elfcpp::R_X86_64_TLSLD:            // Local-dynamic
3833       if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
3834         {
3835           // See above comment for R_X86_64_TLSGD.
3836           optimized_type = tls::TLSOPT_NONE;
3837         }
3838       if (optimized_type == tls::TLSOPT_TO_LE)
3839         {
3840           if (tls_segment == NULL)
3841             {
3842               gold_assert(parameters->errors()->error_count() > 0
3843                           || issue_undefined_symbol_error(gsym));
3844               return;
3845             }
3846           this->tls_ld_to_le(relinfo, relnum, tls_segment, rela, r_type,
3847                              value, view, view_size);
3848           break;
3849         }
3850       else if (optimized_type == tls::TLSOPT_NONE)
3851         {
3852           // Relocate the field with the offset of the GOT entry for
3853           // the module index.
3854           unsigned int got_offset;
3855           got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
3856                         - target->got_size());
3857           value = target->got_plt_section()->address() + got_offset;
3858           Relocate_functions<size, false>::pcrela32(view, value, addend,
3859                                                     address);
3860           break;
3861         }
3862       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3863                              _("unsupported reloc %u"), r_type);
3864       break;
3865
3866     case elfcpp::R_X86_64_DTPOFF32:
3867       // This relocation type is used in debugging information.
3868       // In that case we need to not optimize the value.  If the
3869       // section is not executable, then we assume we should not
3870       // optimize this reloc.  See comments above for R_X86_64_TLSGD,
3871       // R_X86_64_GOTPC32_TLSDESC, R_X86_64_TLSDESC_CALL, and
3872       // R_X86_64_TLSLD.
3873       if (optimized_type == tls::TLSOPT_TO_LE && is_executable)
3874         {
3875           if (tls_segment == NULL)
3876             {
3877               gold_assert(parameters->errors()->error_count() > 0
3878                           || issue_undefined_symbol_error(gsym));
3879               return;
3880             }
3881           value -= tls_segment->memsz();
3882         }
3883       Relocate_functions<size, false>::rela32(view, value, addend);
3884       break;
3885
3886     case elfcpp::R_X86_64_DTPOFF64:
3887       // See R_X86_64_DTPOFF32, just above, for why we check for is_executable.
3888       if (optimized_type == tls::TLSOPT_TO_LE && is_executable)
3889         {
3890           if (tls_segment == NULL)
3891             {
3892               gold_assert(parameters->errors()->error_count() > 0
3893                           || issue_undefined_symbol_error(gsym));
3894               return;
3895             }
3896           value -= tls_segment->memsz();
3897         }
3898       Relocate_functions<size, false>::rela64(view, value, addend);
3899       break;
3900
3901     case elfcpp::R_X86_64_GOTTPOFF:         // Initial-exec
3902       if (gsym != NULL
3903           && gsym->is_undefined()
3904           && parameters->options().output_is_executable())
3905         {
3906           Target_x86_64<size>::Relocate::tls_ie_to_le(relinfo, relnum,
3907                                                       NULL, rela,
3908                                                       r_type, value, view,
3909                                                       view_size);
3910           break;
3911         }
3912       else if (optimized_type == tls::TLSOPT_TO_LE)
3913         {
3914           if (tls_segment == NULL)
3915             {
3916               gold_assert(parameters->errors()->error_count() > 0
3917                           || issue_undefined_symbol_error(gsym));
3918               return;
3919             }
3920           Target_x86_64<size>::Relocate::tls_ie_to_le(relinfo, relnum,
3921                                                       tls_segment, rela,
3922                                                       r_type, value, view,
3923                                                       view_size);
3924           break;
3925         }
3926       else if (optimized_type == tls::TLSOPT_NONE)
3927         {
3928           // Relocate the field with the offset of the GOT entry for
3929           // the tp-relative offset of the symbol.
3930           unsigned int got_offset;
3931           if (gsym != NULL)
3932             {
3933               gold_assert(gsym->has_got_offset(GOT_TYPE_TLS_OFFSET));
3934               got_offset = (gsym->got_offset(GOT_TYPE_TLS_OFFSET)
3935                             - target->got_size());
3936             }
3937           else
3938             {
3939               unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
3940               gold_assert(object->local_has_got_offset(r_sym,
3941                                                        GOT_TYPE_TLS_OFFSET));
3942               got_offset = (object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET)
3943                             - target->got_size());
3944             }
3945           value = target->got_plt_section()->address() + got_offset;
3946           Relocate_functions<size, false>::pcrela32(view, value, addend,
3947                                                     address);
3948           break;
3949         }
3950       gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
3951                              _("unsupported reloc type %u"),
3952                              r_type);
3953       break;
3954
3955     case elfcpp::R_X86_64_TPOFF32:          // Local-exec
3956       if (tls_segment == NULL)
3957         {
3958           gold_assert(parameters->errors()->error_count() > 0
3959                       || issue_undefined_symbol_error(gsym));
3960           return;
3961         }
3962       value -= tls_segment->memsz();
3963       Relocate_functions<size, false>::rela32(view, value, addend);
3964       break;
3965     }
3966 }
3967
3968 // Do a relocation in which we convert a TLS General-Dynamic to an
3969 // Initial-Exec.
3970
3971 template<int size>
3972 inline void
3973 Target_x86_64<size>::Relocate::tls_gd_to_ie(
3974     const Relocate_info<size, false>* relinfo,
3975     size_t relnum,
3976     Output_segment*,
3977     const elfcpp::Rela<size, false>& rela,
3978     unsigned int,
3979     typename elfcpp::Elf_types<size>::Elf_Addr value,
3980     unsigned char* view,
3981     typename elfcpp::Elf_types<size>::Elf_Addr address,
3982     section_size_type view_size)
3983 {
3984   // For SIZE == 64:
3985   //    .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
3986   //    .word 0x6666; rex64; call __tls_get_addr
3987   //    ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
3988   // For SIZE == 32:
3989   //    leaq foo@tlsgd(%rip),%rdi;
3990   //    .word 0x6666; rex64; call __tls_get_addr
3991   //    ==> movl %fs:0,%eax; addq x@gottpoff(%rip),%rax
3992
3993   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
3994   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
3995                  (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0));
3996
3997   if (size == 64)
3998     {
3999       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
4000                        -4);
4001       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4002                      (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
4003       memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0",
4004              16);
4005     }
4006   else
4007     {
4008       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
4009                        -3);
4010       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4011                      (memcmp(view - 3, "\x48\x8d\x3d", 3) == 0));
4012       memcpy(view - 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0",
4013              15);
4014     }
4015
4016   const elfcpp::Elf_Xword addend = rela.get_r_addend();
4017   Relocate_functions<size, false>::pcrela32(view + 8, value, addend - 8,
4018                                             address);
4019
4020   // The next reloc should be a PLT32 reloc against __tls_get_addr.
4021   // We can skip it.
4022   this->skip_call_tls_get_addr_ = true;
4023 }
4024
4025 // Do a relocation in which we convert a TLS General-Dynamic to a
4026 // Local-Exec.
4027
4028 template<int size>
4029 inline void
4030 Target_x86_64<size>::Relocate::tls_gd_to_le(
4031     const Relocate_info<size, false>* relinfo,
4032     size_t relnum,
4033     Output_segment* tls_segment,
4034     const elfcpp::Rela<size, false>& rela,
4035     unsigned int,
4036     typename elfcpp::Elf_types<size>::Elf_Addr value,
4037     unsigned char* view,
4038     section_size_type view_size)
4039 {
4040   // For SIZE == 64:
4041   //    .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
4042   //    .word 0x6666; rex64; call __tls_get_addr
4043   //    ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
4044   // For SIZE == 32:
4045   //    leaq foo@tlsgd(%rip),%rdi;
4046   //    .word 0x6666; rex64; call __tls_get_addr
4047   //    ==> movl %fs:0,%eax; leaq x@tpoff(%rax),%rax
4048
4049   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
4050   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4051                  (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0));
4052
4053   if (size == 64)
4054     {
4055       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
4056                        -4);
4057       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4058                      (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
4059       memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0",
4060              16);
4061     }
4062   else
4063     {
4064       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
4065                        -3);
4066       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4067                      (memcmp(view - 3, "\x48\x8d\x3d", 3) == 0));
4068
4069       memcpy(view - 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0",
4070              15);
4071     }
4072
4073   value -= tls_segment->memsz();
4074   Relocate_functions<size, false>::rela32(view + 8, value, 0);
4075
4076   // The next reloc should be a PLT32 reloc against __tls_get_addr.
4077   // We can skip it.
4078   this->skip_call_tls_get_addr_ = true;
4079 }
4080
4081 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
4082
4083 template<int size>
4084 inline void
4085 Target_x86_64<size>::Relocate::tls_desc_gd_to_ie(
4086     const Relocate_info<size, false>* relinfo,
4087     size_t relnum,
4088     Output_segment*,
4089     const elfcpp::Rela<size, false>& rela,
4090     unsigned int r_type,
4091     typename elfcpp::Elf_types<size>::Elf_Addr value,
4092     unsigned char* view,
4093     typename elfcpp::Elf_types<size>::Elf_Addr address,
4094     section_size_type view_size)
4095 {
4096   if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
4097     {
4098       // leaq foo@tlsdesc(%rip), %rax
4099       // ==> movq foo@gottpoff(%rip), %rax
4100       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
4101       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
4102       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4103                      view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05);
4104       view[-2] = 0x8b;
4105       const elfcpp::Elf_Xword addend = rela.get_r_addend();
4106       Relocate_functions<size, false>::pcrela32(view, value, addend, address);
4107     }
4108   else
4109     {
4110       // call *foo@tlscall(%rax)
4111       // ==> nop; nop
4112       gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
4113       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
4114       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4115                      view[0] == 0xff && view[1] == 0x10);
4116       view[0] = 0x66;
4117       view[1] = 0x90;
4118     }
4119 }
4120
4121 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
4122
4123 template<int size>
4124 inline void
4125 Target_x86_64<size>::Relocate::tls_desc_gd_to_le(
4126     const Relocate_info<size, false>* relinfo,
4127     size_t relnum,
4128     Output_segment* tls_segment,
4129     const elfcpp::Rela<size, false>& rela,
4130     unsigned int r_type,
4131     typename elfcpp::Elf_types<size>::Elf_Addr value,
4132     unsigned char* view,
4133     section_size_type view_size)
4134 {
4135   if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
4136     {
4137       // leaq foo@tlsdesc(%rip), %rax
4138       // ==> movq foo@tpoff, %rax
4139       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
4140       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
4141       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4142                      view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05);
4143       view[-2] = 0xc7;
4144       view[-1] = 0xc0;
4145       value -= tls_segment->memsz();
4146       Relocate_functions<size, false>::rela32(view, value, 0);
4147     }
4148   else
4149     {
4150       // call *foo@tlscall(%rax)
4151       // ==> nop; nop
4152       gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
4153       tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
4154       tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4155                      view[0] == 0xff && view[1] == 0x10);
4156       view[0] = 0x66;
4157       view[1] = 0x90;
4158     }
4159 }
4160
4161 template<int size>
4162 inline void
4163 Target_x86_64<size>::Relocate::tls_ld_to_le(
4164     const Relocate_info<size, false>* relinfo,
4165     size_t relnum,
4166     Output_segment*,
4167     const elfcpp::Rela<size, false>& rela,
4168     unsigned int,
4169     typename elfcpp::Elf_types<size>::Elf_Addr,
4170     unsigned char* view,
4171     section_size_type view_size)
4172 {
4173   // leaq foo@tlsld(%rip),%rdi; call __tls_get_addr@plt;
4174   // For SIZE == 64:
4175   // ... leq foo@dtpoff(%rax),%reg
4176   // ==> .word 0x6666; .byte 0x66; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
4177   // For SIZE == 32:
4178   // ... leq foo@dtpoff(%rax),%reg
4179   // ==> nopl 0x0(%rax); movl %fs:0,%eax ... leaq x@tpoff(%rax),%rdx
4180
4181   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
4182   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 9);
4183
4184   tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4185                  view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x3d);
4186
4187   tls::check_tls(relinfo, relnum, rela.get_r_offset(), view[4] == 0xe8);
4188
4189   if (size == 64)
4190     memcpy(view - 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12);
4191   else
4192     memcpy(view - 3, "\x0f\x1f\x40\x00\x64\x8b\x04\x25\0\0\0\0", 12);
4193
4194   // The next reloc should be a PLT32 reloc against __tls_get_addr.
4195   // We can skip it.
4196   this->skip_call_tls_get_addr_ = true;
4197 }
4198
4199 // Do a relocation in which we convert a TLS Initial-Exec to a
4200 // Local-Exec.
4201
4202 template<int size>
4203 inline void
4204 Target_x86_64<size>::Relocate::tls_ie_to_le(
4205     const Relocate_info<size, false>* relinfo,
4206     size_t relnum,
4207     Output_segment* tls_segment,
4208     const elfcpp::Rela<size, false>& rela,
4209     unsigned int,
4210     typename elfcpp::Elf_types<size>::Elf_Addr value,
4211     unsigned char* view,
4212     section_size_type view_size)
4213 {
4214   // We need to examine the opcodes to figure out which instruction we
4215   // are looking at.
4216
4217   // movq foo@gottpoff(%rip),%reg  ==>  movq $YY,%reg
4218   // addq foo@gottpoff(%rip),%reg  ==>  addq $YY,%reg
4219
4220   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
4221   tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
4222
4223   unsigned char op1 = view[-3];
4224   unsigned char op2 = view[-2];
4225   unsigned char op3 = view[-1];
4226   unsigned char reg = op3 >> 3;
4227
4228   if (op2 == 0x8b)
4229     {
4230       // movq
4231       if (op1 == 0x4c)
4232         view[-3] = 0x49;
4233       else if (size == 32 && op1 == 0x44)
4234         view[-3] = 0x41;
4235       view[-2] = 0xc7;
4236       view[-1] = 0xc0 | reg;
4237     }
4238   else if (reg == 4)
4239     {
4240       // Special handling for %rsp.
4241       if (op1 == 0x4c)
4242         view[-3] = 0x49;
4243       else if (size == 32 && op1 == 0x44)
4244         view[-3] = 0x41;
4245       view[-2] = 0x81;
4246       view[-1] = 0xc0 | reg;
4247     }
4248   else
4249     {
4250       // addq
4251       if (op1 == 0x4c)
4252         view[-3] = 0x4d;
4253       else if (size == 32 && op1 == 0x44)
4254         view[-3] = 0x45;
4255       view[-2] = 0x8d;
4256       view[-1] = 0x80 | reg | (reg << 3);
4257     }
4258
4259   if (tls_segment != NULL)
4260     value -= tls_segment->memsz();
4261   Relocate_functions<size, false>::rela32(view, value, 0);
4262 }
4263
4264 // Relocate section data.
4265
4266 template<int size>
4267 void
4268 Target_x86_64<size>::relocate_section(
4269     const Relocate_info<size, false>* relinfo,
4270     unsigned int sh_type,
4271     const unsigned char* prelocs,
4272     size_t reloc_count,
4273     Output_section* output_section,
4274     bool needs_special_offset_handling,
4275     unsigned char* view,
4276     typename elfcpp::Elf_types<size>::Elf_Addr address,
4277     section_size_type view_size,
4278     const Reloc_symbol_changes* reloc_symbol_changes)
4279 {
4280   typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
4281       Classify_reloc;
4282
4283   gold_assert(sh_type == elfcpp::SHT_RELA);
4284
4285   gold::relocate_section<size, false, Target_x86_64<size>, Relocate,
4286                          gold::Default_comdat_behavior, Classify_reloc>(
4287     relinfo,
4288     this,
4289     prelocs,
4290     reloc_count,
4291     output_section,
4292     needs_special_offset_handling,
4293     view,
4294     address,
4295     view_size,
4296     reloc_symbol_changes);
4297 }
4298
4299 // Apply an incremental relocation.  Incremental relocations always refer
4300 // to global symbols.
4301
4302 template<int size>
4303 void
4304 Target_x86_64<size>::apply_relocation(
4305     const Relocate_info<size, false>* relinfo,
4306     typename elfcpp::Elf_types<size>::Elf_Addr r_offset,
4307     unsigned int r_type,
4308     typename elfcpp::Elf_types<size>::Elf_Swxword r_addend,
4309     const Symbol* gsym,
4310     unsigned char* view,
4311     typename elfcpp::Elf_types<size>::Elf_Addr address,
4312     section_size_type view_size)
4313 {
4314   gold::apply_relocation<size, false, Target_x86_64<size>,
4315                          typename Target_x86_64<size>::Relocate>(
4316     relinfo,
4317     this,
4318     r_offset,
4319     r_type,
4320     r_addend,
4321     gsym,
4322     view,
4323     address,
4324     view_size);
4325 }
4326
4327 // Scan the relocs during a relocatable link.
4328
4329 template<int size>
4330 void
4331 Target_x86_64<size>::scan_relocatable_relocs(
4332     Symbol_table* symtab,
4333     Layout* layout,
4334     Sized_relobj_file<size, false>* object,
4335     unsigned int data_shndx,
4336     unsigned int sh_type,
4337     const unsigned char* prelocs,
4338     size_t reloc_count,
4339     Output_section* output_section,
4340     bool needs_special_offset_handling,
4341     size_t local_symbol_count,
4342     const unsigned char* plocal_symbols,
4343     Relocatable_relocs* rr)
4344 {
4345   typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
4346       Classify_reloc;
4347   typedef gold::Default_scan_relocatable_relocs<Classify_reloc>
4348       Scan_relocatable_relocs;
4349
4350   gold_assert(sh_type == elfcpp::SHT_RELA);
4351
4352   gold::scan_relocatable_relocs<size, false, Scan_relocatable_relocs>(
4353     symtab,
4354     layout,
4355     object,
4356     data_shndx,
4357     prelocs,
4358     reloc_count,
4359     output_section,
4360     needs_special_offset_handling,
4361     local_symbol_count,
4362     plocal_symbols,
4363     rr);
4364 }
4365
4366 // Scan the relocs for --emit-relocs.
4367
4368 template<int size>
4369 void
4370 Target_x86_64<size>::emit_relocs_scan(
4371     Symbol_table* symtab,
4372     Layout* layout,
4373     Sized_relobj_file<size, false>* object,
4374     unsigned int data_shndx,
4375     unsigned int sh_type,
4376     const unsigned char* prelocs,
4377     size_t reloc_count,
4378     Output_section* output_section,
4379     bool needs_special_offset_handling,
4380     size_t local_symbol_count,
4381     const unsigned char* plocal_syms,
4382     Relocatable_relocs* rr)
4383 {
4384   typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
4385       Classify_reloc;
4386   typedef gold::Default_emit_relocs_strategy<Classify_reloc>
4387       Emit_relocs_strategy;
4388
4389   gold_assert(sh_type == elfcpp::SHT_RELA);
4390
4391   gold::scan_relocatable_relocs<size, false, Emit_relocs_strategy>(
4392     symtab,
4393     layout,
4394     object,
4395     data_shndx,
4396     prelocs,
4397     reloc_count,
4398     output_section,
4399     needs_special_offset_handling,
4400     local_symbol_count,
4401     plocal_syms,
4402     rr);
4403 }
4404
4405 // Relocate a section during a relocatable link.
4406
4407 template<int size>
4408 void
4409 Target_x86_64<size>::relocate_relocs(
4410     const Relocate_info<size, false>* relinfo,
4411     unsigned int sh_type,
4412     const unsigned char* prelocs,
4413     size_t reloc_count,
4414     Output_section* output_section,
4415     typename elfcpp::Elf_types<size>::Elf_Off offset_in_output_section,
4416     unsigned char* view,
4417     typename elfcpp::Elf_types<size>::Elf_Addr view_address,
4418     section_size_type view_size,
4419     unsigned char* reloc_view,
4420     section_size_type reloc_view_size)
4421 {
4422   typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
4423       Classify_reloc;
4424
4425   gold_assert(sh_type == elfcpp::SHT_RELA);
4426
4427   gold::relocate_relocs<size, false, Classify_reloc>(
4428     relinfo,
4429     prelocs,
4430     reloc_count,
4431     output_section,
4432     offset_in_output_section,
4433     view,
4434     view_address,
4435     view_size,
4436     reloc_view,
4437     reloc_view_size);
4438 }
4439
4440 // Return the value to use for a dynamic which requires special
4441 // treatment.  This is how we support equality comparisons of function
4442 // pointers across shared library boundaries, as described in the
4443 // processor specific ABI supplement.
4444
4445 template<int size>
4446 uint64_t
4447 Target_x86_64<size>::do_dynsym_value(const Symbol* gsym) const
4448 {
4449   gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
4450   return this->plt_address_for_global(gsym);
4451 }
4452
4453 // Return a string used to fill a code section with nops to take up
4454 // the specified length.
4455
4456 template<int size>
4457 std::string
4458 Target_x86_64<size>::do_code_fill(section_size_type length) const
4459 {
4460   if (length >= 16)
4461     {
4462       // Build a jmpq instruction to skip over the bytes.
4463       unsigned char jmp[5];
4464       jmp[0] = 0xe9;
4465       elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
4466       return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
4467               + std::string(length - 5, static_cast<char>(0x90)));
4468     }
4469
4470   // Nop sequences of various lengths.
4471   const char nop1[1] = { '\x90' };                 // nop
4472   const char nop2[2] = { '\x66', '\x90' };         // xchg %ax %ax
4473   const char nop3[3] = { '\x0f', '\x1f', '\x00' }; // nop (%rax)
4474   const char nop4[4] = { '\x0f', '\x1f', '\x40',   // nop 0(%rax)
4475                          '\x00'};
4476   const char nop5[5] = { '\x0f', '\x1f', '\x44',   // nop 0(%rax,%rax,1)
4477                          '\x00', '\x00' };
4478   const char nop6[6] = { '\x66', '\x0f', '\x1f',   // nopw 0(%rax,%rax,1)
4479                          '\x44', '\x00', '\x00' };
4480   const char nop7[7] = { '\x0f', '\x1f', '\x80',   // nopl 0L(%rax)
4481                          '\x00', '\x00', '\x00',
4482                          '\x00' };
4483   const char nop8[8] = { '\x0f', '\x1f', '\x84',   // nopl 0L(%rax,%rax,1)
4484                          '\x00', '\x00', '\x00',
4485                          '\x00', '\x00' };
4486   const char nop9[9] = { '\x66', '\x0f', '\x1f',   // nopw 0L(%rax,%rax,1)
4487                          '\x84', '\x00', '\x00',
4488                          '\x00', '\x00', '\x00' };
4489   const char nop10[10] = { '\x66', '\x2e', '\x0f', // nopw %cs:0L(%rax,%rax,1)
4490                            '\x1f', '\x84', '\x00',
4491                            '\x00', '\x00', '\x00',
4492                            '\x00' };
4493   const char nop11[11] = { '\x66', '\x66', '\x2e', // data16
4494                            '\x0f', '\x1f', '\x84', // nopw %cs:0L(%rax,%rax,1)
4495                            '\x00', '\x00', '\x00',
4496                            '\x00', '\x00' };
4497   const char nop12[12] = { '\x66', '\x66', '\x66', // data16; data16
4498                            '\x2e', '\x0f', '\x1f', // nopw %cs:0L(%rax,%rax,1)
4499                            '\x84', '\x00', '\x00',
4500                            '\x00', '\x00', '\x00' };
4501   const char nop13[13] = { '\x66', '\x66', '\x66', // data16; data16; data16
4502                            '\x66', '\x2e', '\x0f', // nopw %cs:0L(%rax,%rax,1)
4503                            '\x1f', '\x84', '\x00',
4504                            '\x00', '\x00', '\x00',
4505                            '\x00' };
4506   const char nop14[14] = { '\x66', '\x66', '\x66', // data16; data16; data16
4507                            '\x66', '\x66', '\x2e', // data16
4508                            '\x0f', '\x1f', '\x84', // nopw %cs:0L(%rax,%rax,1)
4509                            '\x00', '\x00', '\x00',
4510                            '\x00', '\x00' };
4511   const char nop15[15] = { '\x66', '\x66', '\x66', // data16; data16; data16
4512                            '\x66', '\x66', '\x66', // data16; data16
4513                            '\x2e', '\x0f', '\x1f', // nopw %cs:0L(%rax,%rax,1)
4514                            '\x84', '\x00', '\x00',
4515                            '\x00', '\x00', '\x00' };
4516
4517   const char* nops[16] = {
4518     NULL,
4519     nop1, nop2, nop3, nop4, nop5, nop6, nop7,
4520     nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
4521   };
4522
4523   return std::string(nops[length], length);
4524 }
4525
4526 // Return the addend to use for a target specific relocation.  The
4527 // only target specific relocation is R_X86_64_TLSDESC for a local
4528 // symbol.  We want to set the addend is the offset of the local
4529 // symbol in the TLS segment.
4530
4531 template<int size>
4532 uint64_t
4533 Target_x86_64<size>::do_reloc_addend(void* arg, unsigned int r_type,
4534                                      uint64_t) const
4535 {
4536   gold_assert(r_type == elfcpp::R_X86_64_TLSDESC);
4537   uintptr_t intarg = reinterpret_cast<uintptr_t>(arg);
4538   gold_assert(intarg < this->tlsdesc_reloc_info_.size());
4539   const Tlsdesc_info& ti(this->tlsdesc_reloc_info_[intarg]);
4540   const Symbol_value<size>* psymval = ti.object->local_symbol(ti.r_sym);
4541   gold_assert(psymval->is_tls_symbol());
4542   // The value of a TLS symbol is the offset in the TLS segment.
4543   return psymval->value(ti.object, 0);
4544 }
4545
4546 // Return the value to use for the base of a DW_EH_PE_datarel offset
4547 // in an FDE.  Solaris and SVR4 use DW_EH_PE_datarel because their
4548 // assembler can not write out the difference between two labels in
4549 // different sections, so instead of using a pc-relative value they
4550 // use an offset from the GOT.
4551
4552 template<int size>
4553 uint64_t
4554 Target_x86_64<size>::do_ehframe_datarel_base() const
4555 {
4556   gold_assert(this->global_offset_table_ != NULL);
4557   Symbol* sym = this->global_offset_table_;
4558   Sized_symbol<size>* ssym = static_cast<Sized_symbol<size>*>(sym);
4559   return ssym->value();
4560 }
4561
4562 // FNOFFSET in section SHNDX in OBJECT is the start of a function
4563 // compiled with -fsplit-stack.  The function calls non-split-stack
4564 // code.  We have to change the function so that it always ensures
4565 // that it has enough stack space to run some random function.
4566
4567 static const unsigned char cmp_insn_32[] = { 0x64, 0x3b, 0x24, 0x25 };
4568 static const unsigned char lea_r10_insn_32[] = { 0x44, 0x8d, 0x94, 0x24 };
4569 static const unsigned char lea_r11_insn_32[] = { 0x44, 0x8d, 0x9c, 0x24 };
4570
4571 static const unsigned char cmp_insn_64[] = { 0x64, 0x48, 0x3b, 0x24, 0x25 };
4572 static const unsigned char lea_r10_insn_64[] = { 0x4c, 0x8d, 0x94, 0x24 };
4573 static const unsigned char lea_r11_insn_64[] = { 0x4c, 0x8d, 0x9c, 0x24 };
4574
4575 template<int size>
4576 void
4577 Target_x86_64<size>::do_calls_non_split(Relobj* object, unsigned int shndx,
4578                                         section_offset_type fnoffset,
4579                                         section_size_type fnsize,
4580                                         const unsigned char*,
4581                                         size_t,
4582                                         unsigned char* view,
4583                                         section_size_type view_size,
4584                                         std::string* from,
4585                                         std::string* to) const
4586 {
4587   const char* const cmp_insn = reinterpret_cast<const char*>
4588       (size == 32 ? cmp_insn_32 : cmp_insn_64);
4589   const char* const lea_r10_insn = reinterpret_cast<const char*>
4590       (size == 32 ? lea_r10_insn_32 : lea_r10_insn_64);
4591   const char* const lea_r11_insn = reinterpret_cast<const char*>
4592       (size == 32 ? lea_r11_insn_32 : lea_r11_insn_64);
4593
4594   const size_t cmp_insn_len =
4595       (size == 32 ? sizeof(cmp_insn_32) : sizeof(cmp_insn_64));
4596   const size_t lea_r10_insn_len =
4597       (size == 32 ? sizeof(lea_r10_insn_32) : sizeof(lea_r10_insn_64));
4598   const size_t lea_r11_insn_len =
4599       (size == 32 ? sizeof(lea_r11_insn_32) : sizeof(lea_r11_insn_64));
4600   const size_t nop_len = (size == 32 ? 7 : 8);
4601
4602   // The function starts with a comparison of the stack pointer and a
4603   // field in the TCB.  This is followed by a jump.
4604
4605   // cmp %fs:NN,%rsp
4606   if (this->match_view(view, view_size, fnoffset, cmp_insn, cmp_insn_len)
4607       && fnsize > nop_len + 1)
4608     {
4609       // We will call __morestack if the carry flag is set after this
4610       // comparison.  We turn the comparison into an stc instruction
4611       // and some nops.
4612       view[fnoffset] = '\xf9';
4613       this->set_view_to_nop(view, view_size, fnoffset + 1, nop_len);
4614     }
4615   // lea NN(%rsp),%r10
4616   // lea NN(%rsp),%r11
4617   else if ((this->match_view(view, view_size, fnoffset,
4618                              lea_r10_insn, lea_r10_insn_len)
4619             || this->match_view(view, view_size, fnoffset,
4620                                 lea_r11_insn, lea_r11_insn_len))
4621            && fnsize > 8)
4622     {
4623       // This is loading an offset from the stack pointer for a
4624       // comparison.  The offset is negative, so we decrease the
4625       // offset by the amount of space we need for the stack.  This
4626       // means we will avoid calling __morestack if there happens to
4627       // be plenty of space on the stack already.
4628       unsigned char* pval = view + fnoffset + 4;
4629       uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
4630       val -= parameters->options().split_stack_adjust_size();
4631       elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
4632     }
4633   else
4634     {
4635       if (!object->has_no_split_stack())
4636         object->error(_("failed to match split-stack sequence at "
4637                         "section %u offset %0zx"),
4638                       shndx, static_cast<size_t>(fnoffset));
4639       return;
4640     }
4641
4642   // We have to change the function so that it calls
4643   // __morestack_non_split instead of __morestack.  The former will
4644   // allocate additional stack space.
4645   *from = "__morestack";
4646   *to = "__morestack_non_split";
4647 }
4648
4649 // The selector for x86_64 object files.  Note this is never instantiated
4650 // directly.  It's only used in Target_selector_x86_64_nacl, below.
4651
4652 template<int size>
4653 class Target_selector_x86_64 : public Target_selector_freebsd
4654 {
4655 public:
4656   Target_selector_x86_64()
4657     : Target_selector_freebsd(elfcpp::EM_X86_64, size, false,
4658                               (size == 64
4659                                ? "elf64-x86-64" : "elf32-x86-64"),
4660                               (size == 64
4661                                ? "elf64-x86-64-freebsd"
4662                                : "elf32-x86-64-freebsd"),
4663                               (size == 64 ? "elf_x86_64" : "elf32_x86_64"))
4664   { }
4665
4666   Target*
4667   do_instantiate_target()
4668   { return new Target_x86_64<size>(); }
4669
4670 };
4671
4672 // NaCl variant.  It uses different PLT contents.
4673
4674 template<int size>
4675 class Output_data_plt_x86_64_nacl : public Output_data_plt_x86_64<size>
4676 {
4677  public:
4678   Output_data_plt_x86_64_nacl(Layout* layout,
4679                               Output_data_got<64, false>* got,
4680                               Output_data_got_plt_x86_64* got_plt,
4681                               Output_data_space* got_irelative)
4682     : Output_data_plt_x86_64<size>(layout, plt_entry_size,
4683                                    got, got_plt, got_irelative)
4684   { }
4685
4686   Output_data_plt_x86_64_nacl(Layout* layout,
4687                               Output_data_got<64, false>* got,
4688                               Output_data_got_plt_x86_64* got_plt,
4689                               Output_data_space* got_irelative,
4690                               unsigned int plt_count)
4691     : Output_data_plt_x86_64<size>(layout, plt_entry_size,
4692                                    got, got_plt, got_irelative,
4693                                    plt_count)
4694   { }
4695
4696  protected:
4697   virtual unsigned int
4698   do_get_plt_entry_size() const
4699   { return plt_entry_size; }
4700
4701   virtual void
4702   do_add_eh_frame(Layout* layout)
4703   {
4704     layout->add_eh_frame_for_plt(this,
4705                                  this->plt_eh_frame_cie,
4706                                  this->plt_eh_frame_cie_size,
4707                                  plt_eh_frame_fde,
4708                                  plt_eh_frame_fde_size);
4709   }
4710
4711   virtual void
4712   do_fill_first_plt_entry(unsigned char* pov,
4713                           typename elfcpp::Elf_types<size>::Elf_Addr got_addr,
4714                           typename elfcpp::Elf_types<size>::Elf_Addr plt_addr);
4715
4716   virtual unsigned int
4717   do_fill_plt_entry(unsigned char* pov,
4718                     typename elfcpp::Elf_types<size>::Elf_Addr got_address,
4719                     typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
4720                     unsigned int got_offset,
4721                     unsigned int plt_offset,
4722                     unsigned int plt_index);
4723
4724   virtual void
4725   do_fill_tlsdesc_entry(unsigned char* pov,
4726                         typename elfcpp::Elf_types<size>::Elf_Addr got_address,
4727                         typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
4728                         typename elfcpp::Elf_types<size>::Elf_Addr got_base,
4729                         unsigned int tlsdesc_got_offset,
4730                         unsigned int plt_offset);
4731
4732  private:
4733   // The size of an entry in the PLT.
4734   static const int plt_entry_size = 64;
4735
4736   // The first entry in the PLT.
4737   static const unsigned char first_plt_entry[plt_entry_size];
4738
4739   // Other entries in the PLT for an executable.
4740   static const unsigned char plt_entry[plt_entry_size];
4741
4742   // The reserved TLSDESC entry in the PLT for an executable.
4743   static const unsigned char tlsdesc_plt_entry[plt_entry_size];
4744
4745   // The .eh_frame unwind information for the PLT.
4746   static const int plt_eh_frame_fde_size = 32;
4747   static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
4748 };
4749
4750 template<int size>
4751 class Target_x86_64_nacl : public Target_x86_64<size>
4752 {
4753  public:
4754   Target_x86_64_nacl()
4755     : Target_x86_64<size>(&x86_64_nacl_info)
4756   { }
4757
4758   virtual Output_data_plt_x86_64<size>*
4759   do_make_data_plt(Layout* layout,
4760                    Output_data_got<64, false>* got,
4761                    Output_data_got_plt_x86_64* got_plt,
4762                    Output_data_space* got_irelative)
4763   {
4764     return new Output_data_plt_x86_64_nacl<size>(layout, got, got_plt,
4765                                                  got_irelative);
4766   }
4767
4768   virtual Output_data_plt_x86_64<size>*
4769   do_make_data_plt(Layout* layout,
4770                    Output_data_got<64, false>* got,
4771                    Output_data_got_plt_x86_64* got_plt,
4772                    Output_data_space* got_irelative,
4773                    unsigned int plt_count)
4774   {
4775     return new Output_data_plt_x86_64_nacl<size>(layout, got, got_plt,
4776                                                  got_irelative,
4777                                                  plt_count);
4778   }
4779
4780   virtual std::string
4781   do_code_fill(section_size_type length) const;
4782
4783  private:
4784   static const Target::Target_info x86_64_nacl_info;
4785 };
4786
4787 template<>
4788 const Target::Target_info Target_x86_64_nacl<64>::x86_64_nacl_info =
4789 {
4790   64,                   // size
4791   false,                // is_big_endian
4792   elfcpp::EM_X86_64,    // machine_code
4793   false,                // has_make_symbol
4794   false,                // has_resolve
4795   true,                 // has_code_fill
4796   true,                 // is_default_stack_executable
4797   true,                 // can_icf_inline_merge_sections
4798   '\0',                 // wrap_char
4799   "/lib64/ld-nacl-x86-64.so.1", // dynamic_linker
4800   0x20000,              // default_text_segment_address
4801   0x10000,              // abi_pagesize (overridable by -z max-page-size)
4802   0x10000,              // common_pagesize (overridable by -z common-page-size)
4803   true,                 // isolate_execinstr
4804   0x10000000,           // rosegment_gap
4805   elfcpp::SHN_UNDEF,    // small_common_shndx
4806   elfcpp::SHN_X86_64_LCOMMON,   // large_common_shndx
4807   0,                    // small_common_section_flags
4808   elfcpp::SHF_X86_64_LARGE,     // large_common_section_flags
4809   NULL,                 // attributes_section
4810   NULL,                 // attributes_vendor
4811   "_start",             // entry_symbol_name
4812   32,                   // hash_entry_size
4813 };
4814
4815 template<>
4816 const Target::Target_info Target_x86_64_nacl<32>::x86_64_nacl_info =
4817 {
4818   32,                   // size
4819   false,                // is_big_endian
4820   elfcpp::EM_X86_64,    // machine_code
4821   false,                // has_make_symbol
4822   false,                // has_resolve
4823   true,                 // has_code_fill
4824   true,                 // is_default_stack_executable
4825   true,                 // can_icf_inline_merge_sections
4826   '\0',                 // wrap_char
4827   "/lib/ld-nacl-x86-64.so.1", // dynamic_linker
4828   0x20000,              // default_text_segment_address
4829   0x10000,              // abi_pagesize (overridable by -z max-page-size)
4830   0x10000,              // common_pagesize (overridable by -z common-page-size)
4831   true,                 // isolate_execinstr
4832   0x10000000,           // rosegment_gap
4833   elfcpp::SHN_UNDEF,    // small_common_shndx
4834   elfcpp::SHN_X86_64_LCOMMON,   // large_common_shndx
4835   0,                    // small_common_section_flags
4836   elfcpp::SHF_X86_64_LARGE,     // large_common_section_flags
4837   NULL,                 // attributes_section
4838   NULL,                 // attributes_vendor
4839   "_start",             // entry_symbol_name
4840   32,                   // hash_entry_size
4841 };
4842
4843 #define NACLMASK        0xe0            // 32-byte alignment mask.
4844
4845 // The first entry in the PLT.
4846
4847 template<int size>
4848 const unsigned char
4849 Output_data_plt_x86_64_nacl<size>::first_plt_entry[plt_entry_size] =
4850 {
4851   0xff, 0x35,                         // pushq contents of memory address
4852   0, 0, 0, 0,                         // replaced with address of .got + 8
4853   0x4c, 0x8b, 0x1d,                   // mov GOT+16(%rip), %r11
4854   0, 0, 0, 0,                         // replaced with address of .got + 16
4855   0x41, 0x83, 0xe3, NACLMASK,         // and $-32, %r11d
4856   0x4d, 0x01, 0xfb,                   // add %r15, %r11
4857   0x41, 0xff, 0xe3,                   // jmpq *%r11
4858
4859   // 9-byte nop sequence to pad out to the next 32-byte boundary.
4860   0x66, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw 0x0(%rax,%rax,1)
4861
4862   // 32 bytes of nop to pad out to the standard size
4863   0x66, 0x66, 0x66, 0x66, 0x66, 0x66,    // excess data32 prefixes
4864   0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4865   0x66, 0x66, 0x66, 0x66, 0x66, 0x66,    // excess data32 prefixes
4866   0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4867   0x66,                                  // excess data32 prefix
4868   0x90                                   // nop
4869 };
4870
4871 template<int size>
4872 void
4873 Output_data_plt_x86_64_nacl<size>::do_fill_first_plt_entry(
4874     unsigned char* pov,
4875     typename elfcpp::Elf_types<size>::Elf_Addr got_address,
4876     typename elfcpp::Elf_types<size>::Elf_Addr plt_address)
4877 {
4878   memcpy(pov, first_plt_entry, plt_entry_size);
4879   elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
4880                                               (got_address + 8
4881                                                - (plt_address + 2 + 4)));
4882   elfcpp::Swap_unaligned<32, false>::writeval(pov + 9,
4883                                               (got_address + 16
4884                                                - (plt_address + 9 + 4)));
4885 }
4886
4887 // Subsequent entries in the PLT.
4888
4889 template<int size>
4890 const unsigned char
4891 Output_data_plt_x86_64_nacl<size>::plt_entry[plt_entry_size] =
4892 {
4893   0x4c, 0x8b, 0x1d,              // mov name@GOTPCREL(%rip),%r11
4894   0, 0, 0, 0,                    // replaced with address of symbol in .got
4895   0x41, 0x83, 0xe3, NACLMASK,    // and $-32, %r11d
4896   0x4d, 0x01, 0xfb,              // add %r15, %r11
4897   0x41, 0xff, 0xe3,              // jmpq *%r11
4898
4899   // 15-byte nop sequence to pad out to the next 32-byte boundary.
4900   0x66, 0x66, 0x66, 0x66, 0x66, 0x66,    // excess data32 prefixes
4901   0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4902
4903   // Lazy GOT entries point here (32-byte aligned).
4904   0x68,                       // pushq immediate
4905   0, 0, 0, 0,                 // replaced with index into relocation table
4906   0xe9,                       // jmp relative
4907   0, 0, 0, 0,                 // replaced with offset to start of .plt0
4908
4909   // 22 bytes of nop to pad out to the standard size.
4910   0x66, 0x66, 0x66, 0x66, 0x66, 0x66,    // excess data32 prefixes
4911   0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4912   0x0f, 0x1f, 0x80, 0, 0, 0, 0,          // nopl 0x0(%rax)
4913 };
4914
4915 template<int size>
4916 unsigned int
4917 Output_data_plt_x86_64_nacl<size>::do_fill_plt_entry(
4918     unsigned char* pov,
4919     typename elfcpp::Elf_types<size>::Elf_Addr got_address,
4920     typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
4921     unsigned int got_offset,
4922     unsigned int plt_offset,
4923     unsigned int plt_index)
4924 {
4925   memcpy(pov, plt_entry, plt_entry_size);
4926   elfcpp::Swap_unaligned<32, false>::writeval(pov + 3,
4927                                               (got_address + got_offset
4928                                                - (plt_address + plt_offset
4929                                                   + 3 + 4)));
4930
4931   elfcpp::Swap_unaligned<32, false>::writeval(pov + 33, plt_index);
4932   elfcpp::Swap_unaligned<32, false>::writeval(pov + 38,
4933                                               - (plt_offset + 38 + 4));
4934
4935   return 32;
4936 }
4937
4938 // The reserved TLSDESC entry in the PLT.
4939
4940 template<int size>
4941 const unsigned char
4942 Output_data_plt_x86_64_nacl<size>::tlsdesc_plt_entry[plt_entry_size] =
4943 {
4944   0xff, 0x35,                   // pushq x(%rip)
4945   0, 0, 0, 0,   // replaced with address of linkmap GOT entry (at PLTGOT + 8)
4946   0x4c, 0x8b, 0x1d,             // mov y(%rip),%r11
4947   0, 0, 0, 0,   // replaced with offset of reserved TLSDESC_GOT entry
4948   0x41, 0x83, 0xe3, NACLMASK,   // and $-32, %r11d
4949   0x4d, 0x01, 0xfb,             // add %r15, %r11
4950   0x41, 0xff, 0xe3,             // jmpq *%r11
4951
4952   // 41 bytes of nop to pad out to the standard size.
4953   0x66, 0x66, 0x66, 0x66, 0x66, 0x66,    // excess data32 prefixes
4954   0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4955   0x66, 0x66, 0x66, 0x66, 0x66, 0x66,    // excess data32 prefixes
4956   0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4957   0x66, 0x66,                            // excess data32 prefixes
4958   0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
4959 };
4960
4961 template<int size>
4962 void
4963 Output_data_plt_x86_64_nacl<size>::do_fill_tlsdesc_entry(
4964     unsigned char* pov,
4965     typename elfcpp::Elf_types<size>::Elf_Addr got_address,
4966     typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
4967     typename elfcpp::Elf_types<size>::Elf_Addr got_base,
4968     unsigned int tlsdesc_got_offset,
4969     unsigned int plt_offset)
4970 {
4971   memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
4972   elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
4973                                               (got_address + 8
4974                                                - (plt_address + plt_offset
4975                                                   + 2 + 4)));
4976   elfcpp::Swap_unaligned<32, false>::writeval(pov + 9,
4977                                               (got_base
4978                                                + tlsdesc_got_offset
4979                                                - (plt_address + plt_offset
4980                                                   + 9 + 4)));
4981 }
4982
4983 // The .eh_frame unwind information for the PLT.
4984
4985 template<int size>
4986 const unsigned char
4987 Output_data_plt_x86_64_nacl<size>::plt_eh_frame_fde[plt_eh_frame_fde_size] =
4988 {
4989   0, 0, 0, 0,                           // Replaced with offset to .plt.
4990   0, 0, 0, 0,                           // Replaced with size of .plt.
4991   0,                                    // Augmentation size.
4992   elfcpp::DW_CFA_def_cfa_offset, 16,    // DW_CFA_def_cfa_offset: 16.
4993   elfcpp::DW_CFA_advance_loc + 6,       // Advance 6 to __PLT__ + 6.
4994   elfcpp::DW_CFA_def_cfa_offset, 24,    // DW_CFA_def_cfa_offset: 24.
4995   elfcpp::DW_CFA_advance_loc + 58,      // Advance 58 to __PLT__ + 64.
4996   elfcpp::DW_CFA_def_cfa_expression,    // DW_CFA_def_cfa_expression.
4997   13,                                   // Block length.
4998   elfcpp::DW_OP_breg7, 8,               // Push %rsp + 8.
4999   elfcpp::DW_OP_breg16, 0,              // Push %rip.
5000   elfcpp::DW_OP_const1u, 63,            // Push 0x3f.
5001   elfcpp::DW_OP_and,                    // & (%rip & 0x3f).
5002   elfcpp::DW_OP_const1u, 37,            // Push 0x25.
5003   elfcpp::DW_OP_ge,                     // >= ((%rip & 0x3f) >= 0x25)
5004   elfcpp::DW_OP_lit3,                   // Push 3.
5005   elfcpp::DW_OP_shl,                    // << (((%rip & 0x3f) >= 0x25) << 3)
5006   elfcpp::DW_OP_plus,                   // + ((((%rip&0x3f)>=0x25)<<3)+%rsp+8
5007   elfcpp::DW_CFA_nop,                   // Align to 32 bytes.
5008   elfcpp::DW_CFA_nop
5009 };
5010
5011 // Return a string used to fill a code section with nops.
5012 // For NaCl, long NOPs are only valid if they do not cross
5013 // bundle alignment boundaries, so keep it simple with one-byte NOPs.
5014 template<int size>
5015 std::string
5016 Target_x86_64_nacl<size>::do_code_fill(section_size_type length) const
5017 {
5018   return std::string(length, static_cast<char>(0x90));
5019 }
5020
5021 // The selector for x86_64-nacl object files.
5022
5023 template<int size>
5024 class Target_selector_x86_64_nacl
5025   : public Target_selector_nacl<Target_selector_x86_64<size>,
5026                                 Target_x86_64_nacl<size> >
5027 {
5028  public:
5029   Target_selector_x86_64_nacl()
5030     : Target_selector_nacl<Target_selector_x86_64<size>,
5031                            Target_x86_64_nacl<size> >("x86-64",
5032                                                       size == 64
5033                                                       ? "elf64-x86-64-nacl"
5034                                                       : "elf32-x86-64-nacl",
5035                                                       size == 64
5036                                                       ? "elf_x86_64_nacl"
5037                                                       : "elf32_x86_64_nacl")
5038   { }
5039 };
5040
5041 Target_selector_x86_64_nacl<64> target_selector_x86_64;
5042 Target_selector_x86_64_nacl<32> target_selector_x32;
5043
5044 } // End anonymous namespace.