gold/i386.cc

   1 // i386.cc -- i386 target support for gold.
   2
   3 // Copyright 2006, 2007 Free Software Foundation, Inc.
   4 // Written by Ian Lance Taylor <iant@google.com>.
   5
   6 // This file is part of gold.
   7
   8 // This program is free software; you can redistribute it and/or modify
   9 // it under the terms of the GNU General Public License as published by
  10 // the Free Software Foundation; either version 3 of the License, or
  11 // (at your option) any later version.
  12
  13 // This program is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17
  18 // You should have received a copy of the GNU General Public License
  19 // along with this program; if not, write to the Free Software
  20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  21 // MA 02110-1301, USA.
  22
  23 #include "gold.h"
  24
  25 #include <cstring>
  26
  27 #include "elfcpp.h"
  28 #include "parameters.h"
  29 #include "reloc.h"
  30 #include "i386.h"
  31 #include "object.h"
  32 #include "symtab.h"
  33 #include "layout.h"
  34 #include "output.h"
  35 #include "target.h"
  36 #include "target-reloc.h"
  37 #include "target-select.h"
  38 #include "tls.h"
  39
  40 namespace
  41 {
  42
  43 using namespace gold;
  44
  45 class Output_data_plt_i386;
  46
  47 // The i386 target class.
  48 // TLS info comes from
  49 //   http://people.redhat.com/drepper/tls.pdf
  50 //   http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
  51
  52 class Target_i386 : public Sized_target<32, false>
  53 {
  54  public:
  55   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
  56
  57   Target_i386()
  58     : Sized_target<32, false>(&i386_info),
  59       got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
  60       copy_relocs_(NULL), dynbss_(NULL)
  61   { }
  62
  63   // Scan the relocations to look for symbol adjustments.
  64   void
  65   scan_relocs(const General_options& options,
  66               Symbol_table* symtab,
  67               Layout* layout,
  68               Sized_relobj<32, false>* object,
  69               unsigned int data_shndx,
  70               unsigned int sh_type,
  71               const unsigned char* prelocs,
  72               size_t reloc_count,
  73               Output_section* output_section,
  74               bool needs_special_offset_handling,
  75               size_t local_symbol_count,
  76               const unsigned char* plocal_symbols);
  77
  78   // Finalize the sections.
  79   void
  80   do_finalize_sections(Layout*);
  81
  82   // Return the value to use for a dynamic which requires special
  83   // treatment.
  84   uint64_t
  85   do_dynsym_value(const Symbol*) const;
  86
  87   // Relocate a section.
  88   void
  89   relocate_section(const Relocate_info<32, false>*,
  90                    unsigned int sh_type,
  91                    const unsigned char* prelocs,
  92                    size_t reloc_count,
  93                    Output_section* output_section,
  94                    bool needs_special_offset_handling,
  95                    unsigned char* view,
  96                    elfcpp::Elf_types<32>::Elf_Addr view_address,
  97                    off_t view_size);
  98
  99   // Return a string used to fill a code section with nops.
 100   std::string
 101   do_code_fill(off_t length);
 102
 103   // Return whether SYM is defined by the ABI.
 104   bool
 105   do_is_defined_by_abi(Symbol* sym) const
 106   { return strcmp(sym->name(), "___tls_get_addr") == 0; }
 107
 108   // Return the size of the GOT section.
 109   off_t
 110   got_size()
 111   {
 112     gold_assert(this->got_ != NULL);
 113     return this->got_->data_size();
 114   }
 115
 116  private:
 117   // The class which scans relocations.
 118   struct Scan
 119   {
 120     inline void
 121     local(const General_options& options, Symbol_table* symtab,
 122           Layout* layout, Target_i386* target,
 123           Sized_relobj<32, false>* object,
 124           unsigned int data_shndx,
 125           Output_section* output_section,
 126           const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
 127           const elfcpp::Sym<32, false>& lsym);
 128
 129     inline void
 130     global(const General_options& options, Symbol_table* symtab,
 131            Layout* layout, Target_i386* target,
 132            Sized_relobj<32, false>* object,
 133            unsigned int data_shndx,
 134            Output_section* output_section,
 135            const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
 136            Symbol* gsym);
 137
 138     static void
 139     unsupported_reloc_local(Sized_relobj<32, false>*, unsigned int r_type);
 140
 141     static void
 142     unsupported_reloc_global(Sized_relobj<32, false>*, unsigned int r_type,
 143                              Symbol*);
 144   };
 145
 146   // The class which implements relocation.
 147   class Relocate
 148   {
 149    public:
 150     Relocate()
 151       : skip_call_tls_get_addr_(false),
 152         local_dynamic_type_(LOCAL_DYNAMIC_NONE)
 153     { }
 154
 155     ~Relocate()
 156     {
 157       if (this->skip_call_tls_get_addr_)
 158         {
 159           // FIXME: This needs to specify the location somehow.
 160           gold_error(_("missing expected TLS relocation"));
 161         }
 162     }
 163
 164     // Return whether the static relocation needs to be applied.
 165     inline bool
 166     should_apply_static_reloc(const Sized_symbol<32>* gsym,
 167                               bool is_absolute_ref,
 168                               bool is_function_call,
 169                               bool is_32bit);
 170
 171     // Do a relocation.  Return false if the caller should not issue
 172     // any warnings about this relocation.
 173     inline bool
 174     relocate(const Relocate_info<32, false>*, Target_i386*, size_t relnum,
 175              const elfcpp::Rel<32, false>&,
 176              unsigned int r_type, const Sized_symbol<32>*,
 177              const Symbol_value<32>*,
 178              unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
 179              off_t);
 180
 181    private:
 182     // Do a TLS relocation.
 183     inline void
 184     relocate_tls(const Relocate_info<32, false>*, Target_i386* target,
 185                  size_t relnum, const elfcpp::Rel<32, false>&,
 186                  unsigned int r_type, const Sized_symbol<32>*,
 187                  const Symbol_value<32>*,
 188                  unsigned char*, elfcpp::Elf_types<32>::Elf_Addr, off_t);
 189
 190     // Do a TLS General-Dynamic to Initial-Exec transition.
 191     inline void
 192     tls_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
 193                  Output_segment* tls_segment,
 194                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 195                  elfcpp::Elf_types<32>::Elf_Addr value,
 196                  unsigned char* view,
 197                  off_t view_size);
 198
 199     // Do a TLS General-Dynamic to Local-Exec transition.
 200     inline void
 201     tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
 202                  Output_segment* tls_segment,
 203                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 204                  elfcpp::Elf_types<32>::Elf_Addr value,
 205                  unsigned char* view,
 206                  off_t view_size);
 207
 208     // Do a TLS Local-Dynamic to Local-Exec transition.
 209     inline void
 210     tls_ld_to_le(const Relocate_info<32, false>*, size_t relnum,
 211                  Output_segment* tls_segment,
 212                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 213                  elfcpp::Elf_types<32>::Elf_Addr value,
 214                  unsigned char* view,
 215                  off_t view_size);
 216
 217     // Do a TLS Initial-Exec to Local-Exec transition.
 218     static inline void
 219     tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum,
 220                  Output_segment* tls_segment,
 221                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 222                  elfcpp::Elf_types<32>::Elf_Addr value,
 223                  unsigned char* view,
 224                  off_t view_size);
 225
 226     // We need to keep track of which type of local dynamic relocation
 227     // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
 228     enum Local_dynamic_type
 229     {
 230       LOCAL_DYNAMIC_NONE,
 231       LOCAL_DYNAMIC_SUN,
 232       LOCAL_DYNAMIC_GNU
 233     };
 234
 235     // This is set if we should skip the next reloc, which should be a
 236     // PLT32 reloc against ___tls_get_addr.
 237     bool skip_call_tls_get_addr_;
 238     // The type of local dynamic relocation we have seen in the section
 239     // being relocated, if any.
 240     Local_dynamic_type local_dynamic_type_;
 241   };
 242
 243   // Adjust TLS relocation type based on the options and whether this
 244   // is a local symbol.
 245   static tls::Tls_optimization
 246   optimize_tls_reloc(bool is_final, int r_type);
 247
 248   // Get the GOT section, creating it if necessary.
 249   Output_data_got<32, false>*
 250   got_section(Symbol_table*, Layout*);
 251
 252   // Get the GOT PLT section.
 253   Output_data_space*
 254   got_plt_section() const
 255   {
 256     gold_assert(this->got_plt_ != NULL);
 257     return this->got_plt_;
 258   }
 259
 260   // Create a PLT entry for a global symbol.
 261   void
 262   make_plt_entry(Symbol_table*, Layout*, Symbol*);
 263
 264   // Get the PLT section.
 265   const Output_data_plt_i386*
 266   plt_section() const
 267   {
 268     gold_assert(this->plt_ != NULL);
 269     return this->plt_;
 270   }
 271
 272   // Get the dynamic reloc section, creating it if necessary.
 273   Reloc_section*
 274   rel_dyn_section(Layout*);
 275
 276   // Return true if the symbol may need a COPY relocation.
 277   // References from an executable object to non-function symbols
 278   // defined in a dynamic object may need a COPY relocation.
 279   bool
 280   may_need_copy_reloc(Symbol* gsym)
 281   {
 282     return (!parameters->output_is_shared()
 283             && gsym->is_from_dynobj()
 284             && gsym->type() != elfcpp::STT_FUNC);
 285   }
 286
 287   // Copy a relocation against a global symbol.
 288   void
 289   copy_reloc(const General_options*, Symbol_table*, Layout*,
 290              Sized_relobj<32, false>*, unsigned int,
 291              Output_section*, Symbol*, const elfcpp::Rel<32, false>&);
 292
 293   // Information about this specific target which we pass to the
 294   // general Target structure.
 295   static const Target::Target_info i386_info;
 296
 297   // The GOT section.
 298   Output_data_got<32, false>* got_;
 299   // The PLT section.
 300   Output_data_plt_i386* plt_;
 301   // The GOT PLT section.
 302   Output_data_space* got_plt_;
 303   // The dynamic reloc section.
 304   Reloc_section* rel_dyn_;
 305   // Relocs saved to avoid a COPY reloc.
 306   Copy_relocs<32, false>* copy_relocs_;
 307   // Space for variables copied with a COPY reloc.
 308   Output_data_space* dynbss_;
 309 };
 310
 311 const Target::Target_info Target_i386::i386_info =
 312 {
 313   32,                   // size
 314   false,                // is_big_endian
 315   elfcpp::EM_386,       // machine_code
 316   false,                // has_make_symbol
 317   false,                // has_resolve
 318   true,                 // has_code_fill
 319   true,                 // is_default_stack_executable
 320   "/usr/lib/libc.so.1", // dynamic_linker
 321   0x08048000,           // default_text_segment_address
 322   0x1000,               // abi_pagesize
 323   0x1000                // common_pagesize
 324 };
 325
 326 // Get the GOT section, creating it if necessary.
 327
 328 Output_data_got<32, false>*
 329 Target_i386::got_section(Symbol_table* symtab, Layout* layout)
 330 {
 331   if (this->got_ == NULL)
 332     {
 333       gold_assert(symtab != NULL && layout != NULL);
 334
 335       this->got_ = new Output_data_got<32, false>();
 336
 337       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
 338                                       elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
 339                                       this->got_);
 340
 341       // The old GNU linker creates a .got.plt section.  We just
 342       // create another set of data in the .got section.  Note that we
 343       // always create a PLT if we create a GOT, although the PLT
 344       // might be empty.
 345       this->got_plt_ = new Output_data_space(4);
 346       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
 347                                       elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
 348                                       this->got_plt_);
 349
 350       // The first three entries are reserved.
 351       this->got_plt_->set_current_data_size(3 * 4);
 352
 353       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
 354       symtab->define_in_output_data(this, "_GLOBAL_OFFSET_TABLE_", NULL,
 355                                     this->got_plt_,
 356                                     0, 0, elfcpp::STT_OBJECT,
 357                                     elfcpp::STB_LOCAL,
 358                                     elfcpp::STV_HIDDEN, 0,
 359                                     false, false);
 360     }
 361
 362   return this->got_;
 363 }
 364
 365 // Get the dynamic reloc section, creating it if necessary.
 366
 367 Target_i386::Reloc_section*
 368 Target_i386::rel_dyn_section(Layout* layout)
 369 {
 370   if (this->rel_dyn_ == NULL)
 371     {
 372       gold_assert(layout != NULL);
 373       this->rel_dyn_ = new Reloc_section();
 374       layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
 375                                       elfcpp::SHF_ALLOC, this->rel_dyn_);
 376     }
 377   return this->rel_dyn_;
 378 }
 379
 380 // A class to handle the PLT data.
 381
 382 class Output_data_plt_i386 : public Output_section_data
 383 {
 384  public:
 385   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
 386
 387   Output_data_plt_i386(Layout*, Output_data_space*);
 388
 389   // Add an entry to the PLT.
 390   void
 391   add_entry(Symbol* gsym);
 392
 393   // Return the .rel.plt section data.
 394   const Reloc_section*
 395   rel_plt() const
 396   { return this->rel_; }
 397
 398  protected:
 399   void
 400   do_adjust_output_section(Output_section* os);
 401
 402  private:
 403   // The size of an entry in the PLT.
 404   static const int plt_entry_size = 16;
 405
 406   // The first entry in the PLT for an executable.
 407   static unsigned char exec_first_plt_entry[plt_entry_size];
 408
 409   // The first entry in the PLT for a shared object.
 410   static unsigned char dyn_first_plt_entry[plt_entry_size];
 411
 412   // Other entries in the PLT for an executable.
 413   static unsigned char exec_plt_entry[plt_entry_size];
 414
 415   // Other entries in the PLT for a shared object.
 416   static unsigned char dyn_plt_entry[plt_entry_size];
 417
 418   // Set the final size.
 419   void
 420   set_final_data_size()
 421   { this->set_data_size((this->count_ + 1) * plt_entry_size); }
 422
 423   // Write out the PLT data.
 424   void
 425   do_write(Output_file*);
 426
 427   // The reloc section.
 428   Reloc_section* rel_;
 429   // The .got.plt section.
 430   Output_data_space* got_plt_;
 431   // The number of PLT entries.
 432   unsigned int count_;
 433 };
 434
 435 // Create the PLT section.  The ordinary .got section is an argument,
 436 // since we need to refer to the start.  We also create our own .got
 437 // section just for PLT entries.
 438
 439 Output_data_plt_i386::Output_data_plt_i386(Layout* layout,
 440                                            Output_data_space* got_plt)
 441   : Output_section_data(4), got_plt_(got_plt), count_(0)
 442 {
 443   this->rel_ = new Reloc_section();
 444   layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
 445                                   elfcpp::SHF_ALLOC, this->rel_);
 446 }
 447
 448 void
 449 Output_data_plt_i386::do_adjust_output_section(Output_section* os)
 450 {
 451   // UnixWare sets the entsize of .plt to 4, and so does the old GNU
 452   // linker, and so do we.
 453   os->set_entsize(4);
 454 }
 455
 456 // Add an entry to the PLT.
 457
 458 void
 459 Output_data_plt_i386::add_entry(Symbol* gsym)
 460 {
 461   gold_assert(!gsym->has_plt_offset());
 462
 463   // Note that when setting the PLT offset we skip the initial
 464   // reserved PLT entry.
 465   gsym->set_plt_offset((this->count_ + 1) * plt_entry_size);
 466
 467   ++this->count_;
 468
 469   off_t got_offset = this->got_plt_->current_data_size();
 470
 471   // Every PLT entry needs a GOT entry which points back to the PLT
 472   // entry (this will be changed by the dynamic linker, normally
 473   // lazily when the function is called).
 474   this->got_plt_->set_current_data_size(got_offset + 4);
 475
 476   // Every PLT entry needs a reloc.
 477   gsym->set_needs_dynsym_entry();
 478   this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_,
 479                          got_offset);
 480
 481   // Note that we don't need to save the symbol.  The contents of the
 482   // PLT are independent of which symbols are used.  The symbols only
 483   // appear in the relocations.
 484 }
 485
 486 // The first entry in the PLT for an executable.
 487
 488 unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] =
 489 {
 490   0xff, 0x35,   // pushl contents of memory address
 491   0, 0, 0, 0,   // replaced with address of .got + 4
 492   0xff, 0x25,   // jmp indirect
 493   0, 0, 0, 0,   // replaced with address of .got + 8
 494   0, 0, 0, 0    // unused
 495 };
 496
 497 // The first entry in the PLT for a shared object.
 498
 499 unsigned char Output_data_plt_i386::dyn_first_plt_entry[plt_entry_size] =
 500 {
 501   0xff, 0xb3, 4, 0, 0, 0,       // pushl 4(%ebx)
 502   0xff, 0xa3, 8, 0, 0, 0,       // jmp *8(%ebx)
 503   0, 0, 0, 0                    // unused
 504 };
 505
 506 // Subsequent entries in the PLT for an executable.
 507
 508 unsigned char Output_data_plt_i386::exec_plt_entry[plt_entry_size] =
 509 {
 510   0xff, 0x25,   // jmp indirect
 511   0, 0, 0, 0,   // replaced with address of symbol in .got
 512   0x68,         // pushl immediate
 513   0, 0, 0, 0,   // replaced with offset into relocation table
 514   0xe9,         // jmp relative
 515   0, 0, 0, 0    // replaced with offset to start of .plt
 516 };
 517
 518 // Subsequent entries in the PLT for a shared object.
 519
 520 unsigned char Output_data_plt_i386::dyn_plt_entry[plt_entry_size] =
 521 {
 522   0xff, 0xa3,   // jmp *offset(%ebx)
 523   0, 0, 0, 0,   // replaced with offset of symbol in .got
 524   0x68,         // pushl immediate
 525   0, 0, 0, 0,   // replaced with offset into relocation table
 526   0xe9,         // jmp relative
 527   0, 0, 0, 0    // replaced with offset to start of .plt
 528 };
 529
 530 // Write out the PLT.  This uses the hand-coded instructions above,
 531 // and adjusts them as needed.  This is all specified by the i386 ELF
 532 // Processor Supplement.
 533
 534 void
 535 Output_data_plt_i386::do_write(Output_file* of)
 536 {
 537   const off_t offset = this->offset();
 538   const off_t oview_size = this->data_size();
 539   unsigned char* const oview = of->get_output_view(offset, oview_size);
 540
 541   const off_t got_file_offset = this->got_plt_->offset();
 542   const off_t got_size = this->got_plt_->data_size();
 543   unsigned char* const got_view = of->get_output_view(got_file_offset,
 544                                                       got_size);
 545
 546   unsigned char* pov = oview;
 547
 548   elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address();
 549   elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address();
 550
 551   if (parameters->output_is_shared())
 552     memcpy(pov, dyn_first_plt_entry, plt_entry_size);
 553   else
 554     {
 555       memcpy(pov, exec_first_plt_entry, plt_entry_size);
 556       elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
 557       elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
 558     }
 559   pov += plt_entry_size;
 560
 561   unsigned char* got_pov = got_view;
 562
 563   memset(got_pov, 0, 12);
 564   got_pov += 12;
 565
 566   const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
 567
 568   unsigned int plt_offset = plt_entry_size;
 569   unsigned int plt_rel_offset = 0;
 570   unsigned int got_offset = 12;
 571   const unsigned int count = this->count_;
 572   for (unsigned int i = 0;
 573        i < count;
 574        ++i,
 575          pov += plt_entry_size,
 576          got_pov += 4,
 577          plt_offset += plt_entry_size,
 578          plt_rel_offset += rel_size,
 579          got_offset += 4)
 580     {
 581       // Set and adjust the PLT entry itself.
 582
 583       if (parameters->output_is_shared())
 584         {
 585           memcpy(pov, dyn_plt_entry, plt_entry_size);
 586           elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
 587         }
 588       else
 589         {
 590           memcpy(pov, exec_plt_entry, plt_entry_size);
 591           elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
 592                                                       (got_address
 593                                                        + got_offset));
 594         }
 595
 596       elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
 597       elfcpp::Swap<32, false>::writeval(pov + 12,
 598                                         - (plt_offset + plt_entry_size));
 599
 600       // Set the entry in the GOT.
 601       elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6);
 602     }
 603
 604   gold_assert(pov - oview == oview_size);
 605   gold_assert(got_pov - got_view == got_size);
 606
 607   of->write_output_view(offset, oview_size, oview);
 608   of->write_output_view(got_file_offset, got_size, got_view);
 609 }
 610
 611 // Create a PLT entry for a global symbol.
 612
 613 void
 614 Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym)
 615 {
 616   if (gsym->has_plt_offset())
 617     return;
 618
 619   if (this->plt_ == NULL)
 620     {
 621       // Create the GOT sections first.
 622       this->got_section(symtab, layout);
 623
 624       this->plt_ = new Output_data_plt_i386(layout, this->got_plt_);
 625       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
 626                                       (elfcpp::SHF_ALLOC
 627                                        | elfcpp::SHF_EXECINSTR),
 628                                       this->plt_);
 629     }
 630
 631   this->plt_->add_entry(gsym);
 632 }
 633
 634 // Handle a relocation against a non-function symbol defined in a
 635 // dynamic object.  The traditional way to handle this is to generate
 636 // a COPY relocation to copy the variable at runtime from the shared
 637 // object into the executable's data segment.  However, this is
 638 // undesirable in general, as if the size of the object changes in the
 639 // dynamic object, the executable will no longer work correctly.  If
 640 // this relocation is in a writable section, then we can create a
 641 // dynamic reloc and the dynamic linker will resolve it to the correct
 642 // address at runtime.  However, we do not want do that if the
 643 // relocation is in a read-only section, as it would prevent the
 644 // readonly segment from being shared.  And if we have to eventually
 645 // generate a COPY reloc, then any dynamic relocations will be
 646 // useless.  So this means that if this is a writable section, we need
 647 // to save the relocation until we see whether we have to create a
 648 // COPY relocation for this symbol for any other relocation.
 649
 650 void
 651 Target_i386::copy_reloc(const General_options* options,
 652                         Symbol_table* symtab,
 653                         Layout* layout,
 654                         Sized_relobj<32, false>* object,
 655                         unsigned int data_shndx,
 656                         Output_section* output_section,
 657                         Symbol* gsym,
 658                         const elfcpp::Rel<32, false>& rel)
 659 {
 660   Sized_symbol<32>* ssym;
 661   ssym = symtab->get_sized_symbol SELECT_SIZE_NAME(32) (gsym
 662                                                         SELECT_SIZE(32));
 663
 664   if (!Copy_relocs<32, false>::need_copy_reloc(options, object,
 665                                                data_shndx, ssym))
 666     {
 667       // So far we do not need a COPY reloc.  Save this relocation.
 668       // If it turns out that we never need a COPY reloc for this
 669       // symbol, then we will emit the relocation.
 670       if (this->copy_relocs_ == NULL)
 671         this->copy_relocs_ = new Copy_relocs<32, false>();
 672       this->copy_relocs_->save(ssym, object, data_shndx, output_section, rel);
 673     }
 674   else
 675     {
 676       // Allocate space for this symbol in the .bss section.
 677
 678       elfcpp::Elf_types<32>::Elf_WXword symsize = ssym->symsize();
 679
 680       // There is no defined way to determine the required alignment
 681       // of the symbol.  We pick the alignment based on the size.  We
 682       // set an arbitrary maximum of 256.
 683       unsigned int align;
 684       for (align = 1; align < 512; align <<= 1)
 685         if ((symsize & align) != 0)
 686           break;
 687
 688       if (this->dynbss_ == NULL)
 689         {
 690           this->dynbss_ = new Output_data_space(align);
 691           layout->add_output_section_data(".bss",
 692                                           elfcpp::SHT_NOBITS,
 693                                           (elfcpp::SHF_ALLOC
 694                                            | elfcpp::SHF_WRITE),
 695                                           this->dynbss_);
 696         }
 697
 698       Output_data_space* dynbss = this->dynbss_;
 699
 700       if (align > dynbss->addralign())
 701         dynbss->set_space_alignment(align);
 702
 703       off_t dynbss_size = dynbss->current_data_size();
 704       dynbss_size = align_address(dynbss_size, align);
 705       off_t offset = dynbss_size;
 706       dynbss->set_current_data_size(dynbss_size + symsize);
 707
 708       symtab->define_with_copy_reloc(this, ssym, dynbss, offset);
 709
 710       // Add the COPY reloc.
 711       Reloc_section* rel_dyn = this->rel_dyn_section(layout);
 712       rel_dyn->add_global(ssym, elfcpp::R_386_COPY, dynbss, offset);
 713     }
 714 }
 715
 716 // Optimize the TLS relocation type based on what we know about the
 717 // symbol.  IS_FINAL is true if the final address of this symbol is
 718 // known at link time.
 719
 720 tls::Tls_optimization
 721 Target_i386::optimize_tls_reloc(bool is_final, int r_type)
 722 {
 723   // If we are generating a shared library, then we can't do anything
 724   // in the linker.
 725   if (parameters->output_is_shared())
 726     return tls::TLSOPT_NONE;
 727
 728   switch (r_type)
 729     {
 730     case elfcpp::R_386_TLS_GD:
 731     case elfcpp::R_386_TLS_GOTDESC:
 732     case elfcpp::R_386_TLS_DESC_CALL:
 733       // These are General-Dynamic which permits fully general TLS
 734       // access.  Since we know that we are generating an executable,
 735       // we can convert this to Initial-Exec.  If we also know that
 736       // this is a local symbol, we can further switch to Local-Exec.
 737       if (is_final)
 738         return tls::TLSOPT_TO_LE;
 739       return tls::TLSOPT_TO_IE;
 740
 741     case elfcpp::R_386_TLS_LDM:
 742       // This is Local-Dynamic, which refers to a local symbol in the
 743       // dynamic TLS block.  Since we know that we generating an
 744       // executable, we can switch to Local-Exec.
 745       return tls::TLSOPT_TO_LE;
 746
 747     case elfcpp::R_386_TLS_LDO_32:
 748       // Another type of Local-Dynamic relocation.
 749       return tls::TLSOPT_TO_LE;
 750
 751     case elfcpp::R_386_TLS_IE:
 752     case elfcpp::R_386_TLS_GOTIE:
 753     case elfcpp::R_386_TLS_IE_32:
 754       // These are Initial-Exec relocs which get the thread offset
 755       // from the GOT.  If we know that we are linking against the
 756       // local symbol, we can switch to Local-Exec, which links the
 757       // thread offset into the instruction.
 758       if (is_final)
 759         return tls::TLSOPT_TO_LE;
 760       return tls::TLSOPT_NONE;
 761
 762     case elfcpp::R_386_TLS_LE:
 763     case elfcpp::R_386_TLS_LE_32:
 764       // When we already have Local-Exec, there is nothing further we
 765       // can do.
 766       return tls::TLSOPT_NONE;
 767
 768     default:
 769       gold_unreachable();
 770     }
 771 }
 772
 773 // Report an unsupported relocation against a local symbol.
 774
 775 void
 776 Target_i386::Scan::unsupported_reloc_local(Sized_relobj<32, false>* object,
 777                                            unsigned int r_type)
 778 {
 779   gold_error(_("%s: unsupported reloc %u against local symbol"),
 780              object->name().c_str(), r_type);
 781 }
 782
 783 // Scan a relocation for a local symbol.
 784
 785 inline void
 786 Target_i386::Scan::local(const General_options&,
 787                          Symbol_table* symtab,
 788                          Layout* layout,
 789                          Target_i386* target,
 790                          Sized_relobj<32, false>* object,
 791                          unsigned int data_shndx,
 792                          Output_section* output_section,
 793                          const elfcpp::Rel<32, false>& reloc,
 794                          unsigned int r_type,
 795                          const elfcpp::Sym<32, false>& lsym)
 796 {
 797   switch (r_type)
 798     {
 799     case elfcpp::R_386_NONE:
 800     case elfcpp::R_386_GNU_VTINHERIT:
 801     case elfcpp::R_386_GNU_VTENTRY:
 802       break;
 803
 804     case elfcpp::R_386_32:
 805       // If building a shared library (or a position-independent
 806       // executable), we need to create a dynamic relocation for
 807       // this location. The relocation applied at link time will
 808       // apply the link-time value, so we flag the location with
 809       // an R_386_RELATIVE relocation so the dynamic loader can
 810       // relocate it easily.
 811       if (parameters->output_is_position_independent())
 812         {
 813           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
 814           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
 815           rel_dyn->add_local_relative(object, r_sym, elfcpp::R_386_RELATIVE,
 816                                       output_section, data_shndx,
 817                                       reloc.get_r_offset());
 818         }
 819       break;
 820
 821     case elfcpp::R_386_16:
 822     case elfcpp::R_386_8:
 823       // If building a shared library (or a position-independent
 824       // executable), we need to create a dynamic relocation for
 825       // this location. Because the addend needs to remain in the
 826       // data section, we need to be careful not to apply this
 827       // relocation statically.
 828       if (parameters->output_is_position_independent())
 829         {
 830           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
 831           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
 832           rel_dyn->add_local(object, r_sym, r_type, output_section, data_shndx,
 833                              reloc.get_r_offset());
 834         }
 835       break;
 836
 837     case elfcpp::R_386_PC32:
 838     case elfcpp::R_386_PC16:
 839     case elfcpp::R_386_PC8:
 840       break;
 841
 842     case elfcpp::R_386_PLT32:
 843       // Since we know this is a local symbol, we can handle this as a
 844       // PC32 reloc.
 845       break;
 846
 847     case elfcpp::R_386_GOTOFF:
 848     case elfcpp::R_386_GOTPC:
 849       // We need a GOT section.
 850       target->got_section(symtab, layout);
 851       break;
 852
 853     case elfcpp::R_386_GOT32:
 854       {
 855         // The symbol requires a GOT entry.
 856         Output_data_got<32, false>* got = target->got_section(symtab, layout);
 857         unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
 858         if (got->add_local(object, r_sym))
 859           {
 860             // If we are generating a shared object, we need to add a
 861             // dynamic RELATIVE relocation for this symbol's GOT entry.
 862             if (parameters->output_is_position_independent())
 863               {
 864                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
 865                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
 866                 rel_dyn->add_local_relative(object, r_sym,
 867                                             elfcpp::R_386_RELATIVE,
 868                                             got,
 869                                             object->local_got_offset(r_sym));
 870               }
 871           }
 872       }
 873       break;
 874
 875       // These are relocations which should only be seen by the
 876       // dynamic linker, and should never be seen here.
 877     case elfcpp::R_386_COPY:
 878     case elfcpp::R_386_GLOB_DAT:
 879     case elfcpp::R_386_JUMP_SLOT:
 880     case elfcpp::R_386_RELATIVE:
 881     case elfcpp::R_386_TLS_TPOFF:
 882     case elfcpp::R_386_TLS_DTPMOD32:
 883     case elfcpp::R_386_TLS_DTPOFF32:
 884     case elfcpp::R_386_TLS_TPOFF32:
 885     case elfcpp::R_386_TLS_DESC:
 886       gold_error(_("%s: unexpected reloc %u in object file"),
 887                  object->name().c_str(), r_type);
 888       break;
 889
 890       // These are initial TLS relocs, which are expected when
 891       // linking.
 892     case elfcpp::R_386_TLS_GD:            // Global-dynamic
 893     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
 894     case elfcpp::R_386_TLS_DESC_CALL:
 895     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
 896     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
 897     case elfcpp::R_386_TLS_IE:            // Initial-exec
 898     case elfcpp::R_386_TLS_IE_32:
 899     case elfcpp::R_386_TLS_GOTIE:
 900     case elfcpp::R_386_TLS_LE:            // Local-exec
 901     case elfcpp::R_386_TLS_LE_32:
 902       {
 903         bool output_is_shared = parameters->output_is_shared();
 904         const tls::Tls_optimization optimized_type
 905             = Target_i386::optimize_tls_reloc(!output_is_shared, r_type);
 906         switch (r_type)
 907           {
 908           case elfcpp::R_386_TLS_GD:          // Global-dynamic
 909             if (optimized_type == tls::TLSOPT_NONE)
 910               {
 911                 // Create a pair of GOT entries for the module index and
 912                 // dtv-relative offset.
 913                 Output_data_got<32, false>* got
 914                     = target->got_section(symtab, layout);
 915                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
 916                 got->add_local_tls_with_rel(object, r_sym,
 917                                             lsym.get_st_shndx(), true,
 918                                             target->rel_dyn_section(layout),
 919                                             elfcpp::R_386_TLS_DTPMOD32);
 920               }
 921             else if (optimized_type != tls::TLSOPT_TO_LE)
 922               unsupported_reloc_local(object, r_type);
 923             break;
 924
 925           case elfcpp::R_386_TLS_GOTDESC:     // Global-dynamic (from ~oliva)
 926           case elfcpp::R_386_TLS_DESC_CALL:
 927             // FIXME: If not relaxing to LE, we need to generate
 928             // a GOT entry with an R_386_TLS_DESC reloc.
 929             if (optimized_type != tls::TLSOPT_TO_LE)
 930               unsupported_reloc_local(object, r_type);
 931             break;
 932
 933           case elfcpp::R_386_TLS_LDM:         // Local-dynamic
 934             if (optimized_type == tls::TLSOPT_NONE)
 935               {
 936                 // Create a GOT entry for the module index.
 937                 Output_data_got<32, false>* got
 938                     = target->got_section(symtab, layout);
 939                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
 940                 got->add_local_tls_with_rel(object, r_sym,
 941                                             lsym.get_st_shndx(), false,
 942                                             target->rel_dyn_section(layout),
 943                                             elfcpp::R_386_TLS_DTPMOD32);
 944               }
 945             else if (optimized_type != tls::TLSOPT_TO_LE)
 946               unsupported_reloc_local(object, r_type);
 947             break;
 948
 949           case elfcpp::R_386_TLS_LDO_32:      // Alternate local-dynamic
 950             break;
 951
 952           case elfcpp::R_386_TLS_IE:          // Initial-exec
 953           case elfcpp::R_386_TLS_IE_32:
 954           case elfcpp::R_386_TLS_GOTIE:
 955             if (optimized_type == tls::TLSOPT_NONE)
 956               {
 957                 // For the R_386_TLS_IE relocation, we need to create a
 958                 // dynamic relocation when building a shared library.
 959                 if (r_type == elfcpp::R_386_TLS_IE
 960                     && parameters->output_is_shared())
 961                   {
 962                     Reloc_section* rel_dyn = target->rel_dyn_section(layout);
 963                     unsigned int r_sym
 964                         = elfcpp::elf_r_sym<32>(reloc.get_r_info());
 965                     rel_dyn->add_local_relative(object, r_sym,
 966                                                 elfcpp::R_386_RELATIVE,
 967                                                 output_section, data_shndx,
 968                                                 reloc.get_r_offset());
 969                   }
 970                 // Create a GOT entry for the tp-relative offset.
 971                 Output_data_got<32, false>* got
 972                     = target->got_section(symtab, layout);
 973                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
 974                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
 975                                            ? elfcpp::R_386_TLS_TPOFF32
 976                                            : elfcpp::R_386_TLS_TPOFF);
 977                 got->add_local_with_rel(object, r_sym,
 978                                         target->rel_dyn_section(layout),
 979                                         dyn_r_type);
 980               }
 981             else if (optimized_type != tls::TLSOPT_TO_LE)
 982               unsupported_reloc_local(object, r_type);
 983             break;
 984
 985           case elfcpp::R_386_TLS_LE:          // Local-exec
 986           case elfcpp::R_386_TLS_LE_32:
 987             if (output_is_shared)
 988               {
 989                 // We need to create a dynamic relocation.
 990                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
 991                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
 992                                            ? elfcpp::R_386_TLS_TPOFF32
 993                                            : elfcpp::R_386_TLS_TPOFF);
 994                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
 995                 rel_dyn->add_local(object, r_sym, dyn_r_type, output_section,
 996                                    data_shndx, reloc.get_r_offset());
 997               }
 998             break;
 999
1000           default:
1001             gold_unreachable();
1002           }
1003       }
1004       break;
1005
1006     case elfcpp::R_386_32PLT:
1007     case elfcpp::R_386_TLS_GD_32:
1008     case elfcpp::R_386_TLS_GD_PUSH:
1009     case elfcpp::R_386_TLS_GD_CALL:
1010     case elfcpp::R_386_TLS_GD_POP:
1011     case elfcpp::R_386_TLS_LDM_32:
1012     case elfcpp::R_386_TLS_LDM_PUSH:
1013     case elfcpp::R_386_TLS_LDM_CALL:
1014     case elfcpp::R_386_TLS_LDM_POP:
1015     case elfcpp::R_386_USED_BY_INTEL_200:
1016     default:
1017       unsupported_reloc_local(object, r_type);
1018       break;
1019     }
1020 }
1021
1022 // Report an unsupported relocation against a global symbol.
1023
1024 void
1025 Target_i386::Scan::unsupported_reloc_global(Sized_relobj<32, false>* object,
1026                                             unsigned int r_type,
1027                                             Symbol* gsym)
1028 {
1029   gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1030              object->name().c_str(), r_type, gsym->demangled_name().c_str());
1031 }
1032
1033 // Scan a relocation for a global symbol.
1034
1035 inline void
1036 Target_i386::Scan::global(const General_options& options,
1037                           Symbol_table* symtab,
1038                           Layout* layout,
1039                           Target_i386* target,
1040                           Sized_relobj<32, false>* object,
1041                           unsigned int data_shndx,
1042                           Output_section* output_section,
1043                           const elfcpp::Rel<32, false>& reloc,
1044                           unsigned int r_type,
1045                           Symbol* gsym)
1046 {
1047   switch (r_type)
1048     {
1049     case elfcpp::R_386_NONE:
1050     case elfcpp::R_386_GNU_VTINHERIT:
1051     case elfcpp::R_386_GNU_VTENTRY:
1052       break;
1053
1054     case elfcpp::R_386_32:
1055     case elfcpp::R_386_16:
1056     case elfcpp::R_386_8:
1057       {
1058         // Make a PLT entry if necessary.
1059         if (gsym->needs_plt_entry())
1060           {
1061             target->make_plt_entry(symtab, layout, gsym);
1062             // Since this is not a PC-relative relocation, we may be
1063             // taking the address of a function. In that case we need to
1064             // set the entry in the dynamic symbol table to the address of
1065             // the PLT entry.
1066             if (gsym->is_from_dynobj())
1067               gsym->set_needs_dynsym_value();
1068           }
1069         // Make a dynamic relocation if necessary.
1070         if (gsym->needs_dynamic_reloc(true, false))
1071           {
1072             if (target->may_need_copy_reloc(gsym))
1073               {
1074                 target->copy_reloc(&options, symtab, layout, object,
1075                                    data_shndx, output_section, gsym, reloc);
1076               }
1077             else if (r_type == elfcpp::R_386_32
1078                      && gsym->can_use_relative_reloc(false))
1079               {
1080                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1081                 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1082                                              output_section, object,
1083                                              data_shndx, reloc.get_r_offset());
1084               }
1085             else
1086               {
1087                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1088                 rel_dyn->add_global(gsym, r_type, output_section, object,
1089                                     data_shndx, reloc.get_r_offset());
1090               }
1091           }
1092       }
1093       break;
1094
1095     case elfcpp::R_386_PC32:
1096     case elfcpp::R_386_PC16:
1097     case elfcpp::R_386_PC8:
1098       {
1099         // Make a PLT entry if necessary.
1100         if (gsym->needs_plt_entry())
1101           {
1102             // These relocations are used for function calls only in
1103             // non-PIC code.  For a 32-bit relocation in a shared library,
1104             // we'll need a text relocation anyway, so we can skip the
1105             // PLT entry and let the dynamic linker bind the call directly
1106             // to the target.  For smaller relocations, we should use a
1107             // PLT entry to ensure that the call can reach.
1108             if (!parameters->output_is_shared()
1109                 || r_type != elfcpp::R_386_PC32)
1110               target->make_plt_entry(symtab, layout, gsym);
1111           }
1112         // Make a dynamic relocation if necessary.
1113         bool is_function_call = (gsym->type() == elfcpp::STT_FUNC);
1114         if (gsym->needs_dynamic_reloc(false, is_function_call))
1115           {
1116             if (target->may_need_copy_reloc(gsym))
1117               {
1118                 target->copy_reloc(&options, symtab, layout, object,
1119                                    data_shndx, output_section, gsym, reloc);
1120               }
1121             else
1122               {
1123                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1124                 rel_dyn->add_global(gsym, r_type, output_section, object,
1125                                     data_shndx, reloc.get_r_offset());
1126               }
1127           }
1128       }
1129       break;
1130
1131     case elfcpp::R_386_GOT32:
1132       {
1133         // The symbol requires a GOT entry.
1134         Output_data_got<32, false>* got = target->got_section(symtab, layout);
1135         if (gsym->final_value_is_known())
1136           got->add_global(gsym);
1137         else
1138           {
1139             // If this symbol is not fully resolved, we need to add a
1140             // GOT entry with a dynamic relocation.
1141             Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1142             if (gsym->is_from_dynobj() || gsym->is_preemptible())
1143               got->add_global_with_rel(gsym, rel_dyn, elfcpp::R_386_GLOB_DAT);
1144             else
1145               {
1146                 if (got->add_global(gsym))
1147                   rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1148                                                got, gsym->got_offset());
1149               }
1150           }
1151       }
1152       break;
1153
1154     case elfcpp::R_386_PLT32:
1155       // If the symbol is fully resolved, this is just a PC32 reloc.
1156       // Otherwise we need a PLT entry.
1157       if (gsym->final_value_is_known())
1158         break;
1159       // If building a shared library, we can also skip the PLT entry
1160       // if the symbol is defined in the output file and is protected
1161       // or hidden.
1162       if (gsym->is_defined()
1163           && !gsym->is_from_dynobj()
1164           && !gsym->is_preemptible())
1165         break;
1166       target->make_plt_entry(symtab, layout, gsym);
1167       break;
1168
1169     case elfcpp::R_386_GOTOFF:
1170     case elfcpp::R_386_GOTPC:
1171       // We need a GOT section.
1172       target->got_section(symtab, layout);
1173       break;
1174
1175       // These are relocations which should only be seen by the
1176       // dynamic linker, and should never be seen here.
1177     case elfcpp::R_386_COPY:
1178     case elfcpp::R_386_GLOB_DAT:
1179     case elfcpp::R_386_JUMP_SLOT:
1180     case elfcpp::R_386_RELATIVE:
1181     case elfcpp::R_386_TLS_TPOFF:
1182     case elfcpp::R_386_TLS_DTPMOD32:
1183     case elfcpp::R_386_TLS_DTPOFF32:
1184     case elfcpp::R_386_TLS_TPOFF32:
1185     case elfcpp::R_386_TLS_DESC:
1186       gold_error(_("%s: unexpected reloc %u in object file"),
1187                  object->name().c_str(), r_type);
1188       break;
1189
1190       // These are initial tls relocs, which are expected when
1191       // linking.
1192     case elfcpp::R_386_TLS_GD:            // Global-dynamic
1193     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
1194     case elfcpp::R_386_TLS_DESC_CALL:
1195     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
1196     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
1197     case elfcpp::R_386_TLS_IE:            // Initial-exec
1198     case elfcpp::R_386_TLS_IE_32:
1199     case elfcpp::R_386_TLS_GOTIE:
1200     case elfcpp::R_386_TLS_LE:            // Local-exec
1201     case elfcpp::R_386_TLS_LE_32:
1202       {
1203         const bool is_final = gsym->final_value_is_known();
1204         const tls::Tls_optimization optimized_type
1205             = Target_i386::optimize_tls_reloc(is_final, r_type);
1206         switch (r_type)
1207           {
1208           case elfcpp::R_386_TLS_GD:          // Global-dynamic
1209             if (optimized_type == tls::TLSOPT_NONE)
1210               {
1211                 // Create a pair of GOT entries for the module index and
1212                 // dtv-relative offset.
1213                 Output_data_got<32, false>* got
1214                     = target->got_section(symtab, layout);
1215                 got->add_global_tls_with_rel(gsym,
1216                                              target->rel_dyn_section(layout),
1217                                              elfcpp::R_386_TLS_DTPMOD32,
1218                                              elfcpp::R_386_TLS_DTPOFF32);
1219               }
1220             else if (optimized_type == tls::TLSOPT_TO_IE)
1221               {
1222                 // Create a GOT entry for the tp-relative offset.
1223                 Output_data_got<32, false>* got
1224                     = target->got_section(symtab, layout);
1225                 got->add_global_with_rel(gsym, target->rel_dyn_section(layout),
1226                                          elfcpp::R_386_TLS_TPOFF32);
1227               }
1228             else if (optimized_type != tls::TLSOPT_TO_LE)
1229               unsupported_reloc_global(object, r_type, gsym);
1230             break;
1231
1232           case elfcpp::R_386_TLS_GOTDESC:     // Global-dynamic (~oliva url)
1233           case elfcpp::R_386_TLS_DESC_CALL:
1234             // FIXME: If not relaxing to LE, we need to generate
1235             // a GOT entry with an R_386_TLS_DESC reloc.
1236             if (optimized_type != tls::TLSOPT_TO_LE)
1237               unsupported_reloc_global(object, r_type, gsym);
1238             unsupported_reloc_global(object, r_type, gsym);
1239             break;
1240
1241           case elfcpp::R_386_TLS_LDM:         // Local-dynamic
1242             // FIXME: If not relaxing to LE, we need to generate a
1243             // DTPMOD32 reloc.
1244             if (optimized_type == tls::TLSOPT_NONE)
1245               {
1246                 // Create a GOT entry for the module index.
1247                 Output_data_got<32, false>* got
1248                     = target->got_section(symtab, layout);
1249                 got->add_global_tls_with_rel(gsym,
1250                                              target->rel_dyn_section(layout),
1251                                              elfcpp::R_386_TLS_DTPMOD32);
1252               }
1253             else if (optimized_type != tls::TLSOPT_TO_LE)
1254               unsupported_reloc_global(object, r_type, gsym);
1255             break;
1256
1257           case elfcpp::R_386_TLS_LDO_32:      // Alternate local-dynamic
1258             break;
1259
1260           case elfcpp::R_386_TLS_IE:          // Initial-exec
1261           case elfcpp::R_386_TLS_IE_32:
1262           case elfcpp::R_386_TLS_GOTIE:
1263             if (optimized_type == tls::TLSOPT_NONE)
1264               {
1265                 // For the R_386_TLS_IE relocation, we need to create a
1266                 // dynamic relocation when building a shared library.
1267                 if (r_type == elfcpp::R_386_TLS_IE
1268                     && parameters->output_is_shared())
1269                   {
1270                     Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1271                     rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1272                                                  output_section, object,
1273                                                  data_shndx,
1274                                                  reloc.get_r_offset());
1275                   }
1276                 // Create a GOT entry for the tp-relative offset.
1277                 Output_data_got<32, false>* got
1278                     = target->got_section(symtab, layout);
1279                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
1280                                            ? elfcpp::R_386_TLS_TPOFF32
1281                                            : elfcpp::R_386_TLS_TPOFF);
1282                 got->add_global_with_rel(gsym,
1283                                          target->rel_dyn_section(layout),
1284                                          dyn_r_type);
1285               }
1286             else if (optimized_type != tls::TLSOPT_TO_LE)
1287               unsupported_reloc_global(object, r_type, gsym);
1288             break;
1289
1290           case elfcpp::R_386_TLS_LE:          // Local-exec
1291           case elfcpp::R_386_TLS_LE_32:
1292             if (parameters->output_is_shared())
1293               {
1294                 // We need to create a dynamic relocation.
1295                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
1296                                            ? elfcpp::R_386_TLS_TPOFF32
1297                                            : elfcpp::R_386_TLS_TPOFF);
1298                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1299                 rel_dyn->add_global(gsym, dyn_r_type, output_section, object,
1300                                     data_shndx, reloc.get_r_offset());
1301               }
1302             break;
1303
1304           default:
1305             gold_unreachable();
1306           }
1307       }
1308       break;
1309
1310     case elfcpp::R_386_32PLT:
1311     case elfcpp::R_386_TLS_GD_32:
1312     case elfcpp::R_386_TLS_GD_PUSH:
1313     case elfcpp::R_386_TLS_GD_CALL:
1314     case elfcpp::R_386_TLS_GD_POP:
1315     case elfcpp::R_386_TLS_LDM_32:
1316     case elfcpp::R_386_TLS_LDM_PUSH:
1317     case elfcpp::R_386_TLS_LDM_CALL:
1318     case elfcpp::R_386_TLS_LDM_POP:
1319     case elfcpp::R_386_USED_BY_INTEL_200:
1320     default:
1321       unsupported_reloc_global(object, r_type, gsym);
1322       break;
1323     }
1324 }
1325
1326 // Scan relocations for a section.
1327
1328 void
1329 Target_i386::scan_relocs(const General_options& options,
1330                          Symbol_table* symtab,
1331                          Layout* layout,
1332                          Sized_relobj<32, false>* object,
1333                          unsigned int data_shndx,
1334                          unsigned int sh_type,
1335                          const unsigned char* prelocs,
1336                          size_t reloc_count,
1337                          Output_section* output_section,
1338                          bool needs_special_offset_handling,
1339                          size_t local_symbol_count,
1340                          const unsigned char* plocal_symbols)
1341 {
1342   if (sh_type == elfcpp::SHT_RELA)
1343     {
1344       gold_error(_("%s: unsupported RELA reloc section"),
1345                  object->name().c_str());
1346       return;
1347     }
1348
1349   gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL,
1350                     Target_i386::Scan>(
1351     options,
1352     symtab,
1353     layout,
1354     this,
1355     object,
1356     data_shndx,
1357     prelocs,
1358     reloc_count,
1359     output_section,
1360     needs_special_offset_handling,
1361     local_symbol_count,
1362     plocal_symbols);
1363 }
1364
1365 // Finalize the sections.
1366
1367 void
1368 Target_i386::do_finalize_sections(Layout* layout)
1369 {
1370   // Fill in some more dynamic tags.
1371   Output_data_dynamic* const odyn = layout->dynamic_data();
1372   if (odyn != NULL)
1373     {
1374       if (this->got_plt_ != NULL)
1375         odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_);
1376
1377       if (this->plt_ != NULL)
1378         {
1379           const Output_data* od = this->plt_->rel_plt();
1380           odyn->add_section_size(elfcpp::DT_PLTRELSZ, od);
1381           odyn->add_section_address(elfcpp::DT_JMPREL, od);
1382           odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_REL);
1383         }
1384
1385       if (this->rel_dyn_ != NULL)
1386         {
1387           const Output_data* od = this->rel_dyn_;
1388           odyn->add_section_address(elfcpp::DT_REL, od);
1389           odyn->add_section_size(elfcpp::DT_RELSZ, od);
1390           odyn->add_constant(elfcpp::DT_RELENT,
1391                              elfcpp::Elf_sizes<32>::rel_size);
1392         }
1393
1394       if (!parameters->output_is_shared())
1395         {
1396           // The value of the DT_DEBUG tag is filled in by the dynamic
1397           // linker at run time, and used by the debugger.
1398           odyn->add_constant(elfcpp::DT_DEBUG, 0);
1399         }
1400     }
1401
1402   // Emit any relocs we saved in an attempt to avoid generating COPY
1403   // relocs.
1404   if (this->copy_relocs_ == NULL)
1405     return;
1406   if (this->copy_relocs_->any_to_emit())
1407     {
1408       Reloc_section* rel_dyn = this->rel_dyn_section(layout);
1409       this->copy_relocs_->emit(rel_dyn);
1410     }
1411   delete this->copy_relocs_;
1412   this->copy_relocs_ = NULL;
1413 }
1414
1415 // Return whether a direct absolute static relocation needs to be applied.
1416 // In cases where Scan::local() or Scan::global() has created
1417 // a dynamic relocation other than R_386_RELATIVE, the addend
1418 // of the relocation is carried in the data, and we must not
1419 // apply the static relocation.
1420
1421 inline bool
1422 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol<32>* gsym,
1423                                                  bool is_absolute_ref,
1424                                                  bool is_function_call,
1425                                                  bool is_32bit)
1426 {
1427   // For local symbols, we will have created a non-RELATIVE dynamic
1428   // relocation only if (a) the output is position independent,
1429   // (b) the relocation is absolute (not pc- or segment-relative), and
1430   // (c) the relocation is not 32 bits wide.
1431   if (gsym == NULL)
1432     return !(parameters->output_is_position_independent()
1433              && is_absolute_ref
1434              && !is_32bit);
1435
1436   // For global symbols, we use the same helper routines used in the scan pass.
1437   return !(gsym->needs_dynamic_reloc(is_absolute_ref, is_function_call)
1438            && !gsym->can_use_relative_reloc(is_function_call));
1439 }
1440
1441 // Perform a relocation.
1442
1443 inline bool
1444 Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
1445                                 Target_i386* target,
1446                                 size_t relnum,
1447                                 const elfcpp::Rel<32, false>& rel,
1448                                 unsigned int r_type,
1449                                 const Sized_symbol<32>* gsym,
1450                                 const Symbol_value<32>* psymval,
1451                                 unsigned char* view,
1452                                 elfcpp::Elf_types<32>::Elf_Addr address,
1453                                 off_t view_size)
1454 {
1455   if (this->skip_call_tls_get_addr_)
1456     {
1457       if (r_type != elfcpp::R_386_PLT32
1458           || gsym == NULL
1459           || strcmp(gsym->name(), "___tls_get_addr") != 0)
1460         gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1461                                _("missing expected TLS relocation"));
1462       else
1463         {
1464           this->skip_call_tls_get_addr_ = false;
1465           return false;
1466         }
1467     }
1468
1469   // Pick the value to use for symbols defined in shared objects.
1470   Symbol_value<32> symval;
1471   if (gsym != NULL
1472       && (gsym->is_from_dynobj()
1473           || (parameters->output_is_shared()
1474               && gsym->is_preemptible()))
1475       && gsym->has_plt_offset())
1476     {
1477       symval.set_output_value(target->plt_section()->address()
1478                               + gsym->plt_offset());
1479       psymval = &symval;
1480     }
1481
1482   const Sized_relobj<32, false>* object = relinfo->object;
1483
1484   // Get the GOT offset if needed.
1485   // The GOT pointer points to the end of the GOT section.
1486   // We need to subtract the size of the GOT section to get
1487   // the actual offset to use in the relocation.
1488   bool have_got_offset = false;
1489   unsigned int got_offset = 0;
1490   switch (r_type)
1491     {
1492     case elfcpp::R_386_GOT32:
1493       if (gsym != NULL)
1494         {
1495           gold_assert(gsym->has_got_offset());
1496           got_offset = gsym->got_offset() - target->got_size();
1497         }
1498       else
1499         {
1500           unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
1501           gold_assert(object->local_has_got_offset(r_sym));
1502           got_offset = object->local_got_offset(r_sym) - target->got_size();
1503         }
1504       have_got_offset = true;
1505       break;
1506
1507     default:
1508       break;
1509     }
1510
1511   switch (r_type)
1512     {
1513     case elfcpp::R_386_NONE:
1514     case elfcpp::R_386_GNU_VTINHERIT:
1515     case elfcpp::R_386_GNU_VTENTRY:
1516       break;
1517
1518     case elfcpp::R_386_32:
1519       if (should_apply_static_reloc(gsym, true, false, true))
1520         Relocate_functions<32, false>::rel32(view, object, psymval);
1521       break;
1522
1523     case elfcpp::R_386_PC32:
1524       {
1525         bool is_function_call = (gsym != NULL
1526                                  && gsym->type() == elfcpp::STT_FUNC);
1527         if (should_apply_static_reloc(gsym, false, is_function_call, true))
1528           Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1529       }
1530       break;
1531
1532     case elfcpp::R_386_16:
1533       if (should_apply_static_reloc(gsym, true, false, false))
1534         Relocate_functions<32, false>::rel16(view, object, psymval);
1535       break;
1536
1537     case elfcpp::R_386_PC16:
1538       {
1539         bool is_function_call = (gsym != NULL
1540                                  && gsym->type() == elfcpp::STT_FUNC);
1541         if (should_apply_static_reloc(gsym, false, is_function_call, false))
1542           Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1543       }
1544       break;
1545
1546     case elfcpp::R_386_8:
1547       if (should_apply_static_reloc(gsym, true, false, false))
1548         Relocate_functions<32, false>::rel8(view, object, psymval);
1549       break;
1550
1551     case elfcpp::R_386_PC8:
1552       {
1553         bool is_function_call = (gsym != NULL
1554                                  && gsym->type() == elfcpp::STT_FUNC);
1555         if (should_apply_static_reloc(gsym, false, is_function_call, false))
1556           Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1557       }
1558       break;
1559
1560     case elfcpp::R_386_PLT32:
1561       gold_assert(gsym == NULL
1562                   || gsym->has_plt_offset()
1563                   || gsym->final_value_is_known());
1564       Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1565       break;
1566
1567     case elfcpp::R_386_GOT32:
1568       gold_assert(have_got_offset);
1569       Relocate_functions<32, false>::rel32(view, got_offset);
1570       break;
1571
1572     case elfcpp::R_386_GOTOFF:
1573       {
1574         elfcpp::Elf_types<32>::Elf_Addr value;
1575         value = (psymval->value(object, 0)
1576                  - target->got_plt_section()->address());
1577         Relocate_functions<32, false>::rel32(view, value);
1578       }
1579       break;
1580
1581     case elfcpp::R_386_GOTPC:
1582       {
1583         elfcpp::Elf_types<32>::Elf_Addr value;
1584         value = target->got_plt_section()->address();
1585         Relocate_functions<32, false>::pcrel32(view, value, address);
1586       }
1587       break;
1588
1589     case elfcpp::R_386_COPY:
1590     case elfcpp::R_386_GLOB_DAT:
1591     case elfcpp::R_386_JUMP_SLOT:
1592     case elfcpp::R_386_RELATIVE:
1593       // These are outstanding tls relocs, which are unexpected when
1594       // linking.
1595     case elfcpp::R_386_TLS_TPOFF:
1596     case elfcpp::R_386_TLS_DTPMOD32:
1597     case elfcpp::R_386_TLS_DTPOFF32:
1598     case elfcpp::R_386_TLS_TPOFF32:
1599     case elfcpp::R_386_TLS_DESC:
1600       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1601                              _("unexpected reloc %u in object file"),
1602                              r_type);
1603       break;
1604
1605       // These are initial tls relocs, which are expected when
1606       // linking.
1607     case elfcpp::R_386_TLS_GD:             // Global-dynamic
1608     case elfcpp::R_386_TLS_GOTDESC:        // Global-dynamic (from ~oliva url)
1609     case elfcpp::R_386_TLS_DESC_CALL:
1610     case elfcpp::R_386_TLS_LDM:            // Local-dynamic
1611     case elfcpp::R_386_TLS_LDO_32:         // Alternate local-dynamic
1612     case elfcpp::R_386_TLS_IE:             // Initial-exec
1613     case elfcpp::R_386_TLS_IE_32:
1614     case elfcpp::R_386_TLS_GOTIE:
1615     case elfcpp::R_386_TLS_LE:             // Local-exec
1616     case elfcpp::R_386_TLS_LE_32:
1617       this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
1618                          view, address, view_size);
1619       break;
1620
1621     case elfcpp::R_386_32PLT:
1622     case elfcpp::R_386_TLS_GD_32:
1623     case elfcpp::R_386_TLS_GD_PUSH:
1624     case elfcpp::R_386_TLS_GD_CALL:
1625     case elfcpp::R_386_TLS_GD_POP:
1626     case elfcpp::R_386_TLS_LDM_32:
1627     case elfcpp::R_386_TLS_LDM_PUSH:
1628     case elfcpp::R_386_TLS_LDM_CALL:
1629     case elfcpp::R_386_TLS_LDM_POP:
1630     case elfcpp::R_386_USED_BY_INTEL_200:
1631     default:
1632       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1633                              _("unsupported reloc %u"),
1634                              r_type);
1635       break;
1636     }
1637
1638   return true;
1639 }
1640
1641 // Perform a TLS relocation.
1642
1643 inline void
1644 Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo,
1645                                     Target_i386* target,
1646                                     size_t relnum,
1647                                     const elfcpp::Rel<32, false>& rel,
1648                                     unsigned int r_type,
1649                                     const Sized_symbol<32>* gsym,
1650                                     const Symbol_value<32>* psymval,
1651                                     unsigned char* view,
1652                                     elfcpp::Elf_types<32>::Elf_Addr,
1653                                     off_t view_size)
1654 {
1655   Output_segment* tls_segment = relinfo->layout->tls_segment();
1656
1657   const Sized_relobj<32, false>* object = relinfo->object;
1658
1659   elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
1660
1661   const bool is_final = (gsym == NULL
1662                          ? !parameters->output_is_position_independent()
1663                          : gsym->final_value_is_known());
1664   const tls::Tls_optimization optimized_type
1665       = Target_i386::optimize_tls_reloc(is_final, r_type);
1666   switch (r_type)
1667     {
1668     case elfcpp::R_386_TLS_GD:           // Global-dynamic
1669       if (optimized_type == tls::TLSOPT_TO_LE)
1670         {
1671           gold_assert(tls_segment != NULL);
1672           this->tls_gd_to_le(relinfo, relnum, tls_segment,
1673                              rel, r_type, value, view,
1674                              view_size);
1675           break;
1676         }
1677       else
1678         {
1679           unsigned int got_offset;
1680           if (gsym != NULL)
1681             {
1682               gold_assert(gsym->has_tls_got_offset(true));
1683               got_offset = gsym->tls_got_offset(true) - target->got_size();
1684             }
1685           else
1686             {
1687               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
1688               gold_assert(object->local_has_tls_got_offset(r_sym, true));
1689               got_offset = (object->local_tls_got_offset(r_sym, true)
1690                             - target->got_size());
1691             }
1692           if (optimized_type == tls::TLSOPT_TO_IE)
1693             {
1694               gold_assert(tls_segment != NULL);
1695               this->tls_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
1696                                  got_offset, view, view_size);
1697               break;
1698             }
1699           else if (optimized_type == tls::TLSOPT_NONE)
1700             {
1701               // Relocate the field with the offset of the pair of GOT
1702               // entries.
1703               Relocate_functions<32, false>::rel32(view, got_offset);
1704               break;
1705             }
1706         }
1707       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1708                              _("unsupported reloc %u"),
1709                              r_type);
1710       break;
1711
1712     case elfcpp::R_386_TLS_GOTDESC:      // Global-dynamic (from ~oliva url)
1713     case elfcpp::R_386_TLS_DESC_CALL:
1714       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1715                              _("unsupported reloc %u"),
1716                              r_type);
1717       break;
1718
1719     case elfcpp::R_386_TLS_LDM:          // Local-dynamic
1720       if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN)
1721         {
1722           gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1723                                  _("both SUN and GNU model "
1724                                    "TLS relocations"));
1725           break;
1726         }
1727       this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
1728       if (optimized_type == tls::TLSOPT_TO_LE)
1729         {
1730           gold_assert(tls_segment != NULL);
1731           this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, r_type,
1732                              value, view, view_size);
1733           break;
1734         }
1735       else if (optimized_type == tls::TLSOPT_NONE)
1736         {
1737           // Relocate the field with the offset of the GOT entry for
1738           // the module index.
1739           unsigned int got_offset;
1740           if (gsym != NULL)
1741             {
1742               gold_assert(gsym->has_tls_got_offset(false));
1743               got_offset = gsym->tls_got_offset(false) - target->got_size();
1744             }
1745           else
1746             {
1747               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
1748               gold_assert(object->local_has_tls_got_offset(r_sym, false));
1749               got_offset = (object->local_tls_got_offset(r_sym, false)
1750                             - target->got_size());
1751             }
1752           Relocate_functions<32, false>::rel32(view, got_offset);
1753           break;
1754         }
1755       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1756                              _("unsupported reloc %u"),
1757                              r_type);
1758       break;
1759
1760     case elfcpp::R_386_TLS_LDO_32:       // Alternate local-dynamic
1761       // This reloc can appear in debugging sections, in which case we
1762       // won't see the TLS_LDM reloc.  The local_dynamic_type field
1763       // tells us this.
1764       gold_assert(tls_segment != NULL);
1765       if (this->local_dynamic_type_ == LOCAL_DYNAMIC_GNU)
1766         value -= tls_segment->memsz();
1767       else if (optimized_type == tls::TLSOPT_TO_LE
1768                && this->local_dynamic_type_ != LOCAL_DYNAMIC_NONE)
1769         value = tls_segment->memsz() - value;
1770       Relocate_functions<32, false>::rel32(view, value);
1771       break;
1772
1773     case elfcpp::R_386_TLS_IE:           // Initial-exec
1774     case elfcpp::R_386_TLS_GOTIE:
1775     case elfcpp::R_386_TLS_IE_32:
1776       if (optimized_type == tls::TLSOPT_TO_LE)
1777         {
1778           gold_assert(tls_segment != NULL);
1779           Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
1780                                               rel, r_type, value, view,
1781                                               view_size);
1782           break;
1783         }
1784       else if (optimized_type == tls::TLSOPT_NONE)
1785         {
1786           // Relocate the field with the offset of the GOT entry for
1787           // the tp-relative offset of the symbol.
1788           unsigned int got_offset;
1789           if (gsym != NULL)
1790             {
1791               gold_assert(gsym->has_got_offset());
1792               got_offset = gsym->got_offset();
1793             }
1794           else
1795             {
1796               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
1797               gold_assert(object->local_has_got_offset(r_sym));
1798               got_offset = object->local_got_offset(r_sym);
1799             }
1800           // For the R_386_TLS_IE relocation, we need to apply the
1801           // absolute address of the GOT entry.
1802           if (r_type == elfcpp::R_386_TLS_IE)
1803             got_offset += target->got_plt_section()->address();
1804           // All GOT offsets are relative to the end of the GOT.
1805           got_offset -= target->got_size();
1806           Relocate_functions<32, false>::rel32(view, got_offset);
1807           break;
1808         }
1809       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1810                              _("unsupported reloc %u"),
1811                              r_type);
1812       break;
1813
1814     case elfcpp::R_386_TLS_LE:           // Local-exec
1815       // If we're creating a shared library, a dynamic relocation will
1816       // have been created for this location, so do not apply it now.
1817       if (!parameters->output_is_shared())
1818         {
1819           gold_assert(tls_segment != NULL);
1820           value -= tls_segment->memsz();
1821           Relocate_functions<32, false>::rel32(view, value);
1822         }
1823       break;
1824
1825     case elfcpp::R_386_TLS_LE_32:
1826       // If we're creating a shared library, a dynamic relocation will
1827       // have been created for this location, so do not apply it now.
1828       if (!parameters->output_is_shared())
1829         {
1830           gold_assert(tls_segment != NULL);
1831           value = tls_segment->memsz() - value;
1832           Relocate_functions<32, false>::rel32(view, value);
1833         }
1834       break;
1835     }
1836 }
1837
1838 // Do a relocation in which we convert a TLS General-Dynamic to a
1839 // Local-Exec.
1840
1841 inline void
1842 Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo,
1843                                     size_t relnum,
1844                                     Output_segment* tls_segment,
1845                                     const elfcpp::Rel<32, false>& rel,
1846                                     unsigned int,
1847                                     elfcpp::Elf_types<32>::Elf_Addr value,
1848                                     unsigned char* view,
1849                                     off_t view_size)
1850 {
1851   // leal foo(,%reg,1),%eax; call ___tls_get_addr
1852   //  ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
1853   // leal foo(%reg),%eax; call ___tls_get_addr
1854   //  ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
1855
1856   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
1857   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
1858
1859   unsigned char op1 = view[-1];
1860   unsigned char op2 = view[-2];
1861
1862   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
1863                  op2 == 0x8d || op2 == 0x04);
1864   tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
1865
1866   int roff = 5;
1867
1868   if (op2 == 0x04)
1869     {
1870       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
1871       tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
1872       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
1873                      ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
1874       memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
1875     }
1876   else
1877     {
1878       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
1879                      (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
1880       if (static_cast<off_t>(rel.get_r_offset() + 9) < view_size
1881           && view[9] == 0x90)
1882         {
1883           // There is a trailing nop.  Use the size byte subl.
1884           memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
1885           roff = 6;
1886         }
1887       else
1888         {
1889           // Use the five byte subl.
1890           memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
1891         }
1892     }
1893
1894   value = tls_segment->memsz() - value;
1895   Relocate_functions<32, false>::rel32(view + roff, value);
1896
1897   // The next reloc should be a PLT32 reloc against __tls_get_addr.
1898   // We can skip it.
1899   this->skip_call_tls_get_addr_ = true;
1900 }
1901
1902 // Do a relocation in which we convert a TLS General-Dynamic to an
1903 // Initial-Exec.
1904
1905 inline void
1906 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info<32, false>* relinfo,
1907                                     size_t relnum,
1908                                     Output_segment* tls_segment,
1909                                     const elfcpp::Rel<32, false>& rel,
1910                                     unsigned int,
1911                                     elfcpp::Elf_types<32>::Elf_Addr value,
1912                                     unsigned char* view,
1913                                     off_t view_size)
1914 {
1915   // leal foo(,%ebx,1),%eax; call ___tls_get_addr
1916   //  ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
1917
1918   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
1919   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
1920
1921   unsigned char op1 = view[-1];
1922   unsigned char op2 = view[-2];
1923
1924   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
1925                  op2 == 0x8d || op2 == 0x04);
1926   tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
1927
1928   int roff = 5;
1929
1930   // FIXME: For now, support only one form.
1931   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
1932                  op1 == 0x8d && op2 == 0x04);
1933
1934   if (op2 == 0x04)
1935     {
1936       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
1937       tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
1938       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
1939                      ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
1940       memcpy(view - 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
1941     }
1942   else
1943     {
1944       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
1945                      (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
1946       if (static_cast<off_t>(rel.get_r_offset() + 9) < view_size
1947           && view[9] == 0x90)
1948         {
1949           // FIXME: This is not the right instruction sequence.
1950           // There is a trailing nop.  Use the size byte subl.
1951           memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
1952           roff = 6;
1953         }
1954       else
1955         {
1956           // FIXME: This is not the right instruction sequence.
1957           // Use the five byte subl.
1958           memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
1959         }
1960     }
1961
1962   value = tls_segment->memsz() - value;
1963   Relocate_functions<32, false>::rel32(view + roff, value);
1964
1965   // The next reloc should be a PLT32 reloc against __tls_get_addr.
1966   // We can skip it.
1967   this->skip_call_tls_get_addr_ = true;
1968 }
1969
1970 // Do a relocation in which we convert a TLS Local-Dynamic to a
1971 // Local-Exec.
1972
1973 inline void
1974 Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo,
1975                                     size_t relnum,
1976                                     Output_segment*,
1977                                     const elfcpp::Rel<32, false>& rel,
1978                                     unsigned int,
1979                                     elfcpp::Elf_types<32>::Elf_Addr,
1980                                     unsigned char* view,
1981                                     off_t view_size)
1982 {
1983   // leal foo(%reg), %eax; call ___tls_get_addr
1984   // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
1985
1986   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
1987   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
1988
1989   // FIXME: Does this test really always pass?
1990   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
1991                  view[-2] == 0x8d && view[-1] == 0x83);
1992
1993   tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
1994
1995   memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
1996
1997   // The next reloc should be a PLT32 reloc against __tls_get_addr.
1998   // We can skip it.
1999   this->skip_call_tls_get_addr_ = true;
2000 }
2001
2002 // Do a relocation in which we convert a TLS Initial-Exec to a
2003 // Local-Exec.
2004
2005 inline void
2006 Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo,
2007                                     size_t relnum,
2008                                     Output_segment* tls_segment,
2009                                     const elfcpp::Rel<32, false>& rel,
2010                                     unsigned int r_type,
2011                                     elfcpp::Elf_types<32>::Elf_Addr value,
2012                                     unsigned char* view,
2013                                     off_t view_size)
2014 {
2015   // We have to actually change the instructions, which means that we
2016   // need to examine the opcodes to figure out which instruction we
2017   // are looking at.
2018   if (r_type == elfcpp::R_386_TLS_IE)
2019     {
2020       // movl %gs:XX,%eax  ==>  movl $YY,%eax
2021       // movl %gs:XX,%reg  ==>  movl $YY,%reg
2022       // addl %gs:XX,%reg  ==>  addl $YY,%reg
2023       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -1);
2024       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2025
2026       unsigned char op1 = view[-1];
2027       if (op1 == 0xa1)
2028         {
2029           // movl XX,%eax  ==>  movl $YY,%eax
2030           view[-1] = 0xb8;
2031         }
2032       else
2033         {
2034           tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2035
2036           unsigned char op2 = view[-2];
2037           if (op2 == 0x8b)
2038             {
2039               // movl XX,%reg  ==>  movl $YY,%reg
2040               tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2041                              (op1 & 0xc7) == 0x05);
2042               view[-2] = 0xc7;
2043               view[-1] = 0xc0 | ((op1 >> 3) & 7);
2044             }
2045           else if (op2 == 0x03)
2046             {
2047               // addl XX,%reg  ==>  addl $YY,%reg
2048               tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2049                              (op1 & 0xc7) == 0x05);
2050               view[-2] = 0x81;
2051               view[-1] = 0xc0 | ((op1 >> 3) & 7);
2052             }
2053           else
2054             tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
2055         }
2056     }
2057   else
2058     {
2059       // subl %gs:XX(%reg1),%reg2  ==>  subl $YY,%reg2
2060       // movl %gs:XX(%reg1),%reg2  ==>  movl $YY,%reg2
2061       // addl %gs:XX(%reg1),%reg2  ==>  addl $YY,$reg2
2062       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2063       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2064
2065       unsigned char op1 = view[-1];
2066       unsigned char op2 = view[-2];
2067       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2068                      (op1 & 0xc0) == 0x80 && (op1 & 7) != 4);
2069       if (op2 == 0x8b)
2070         {
2071           // movl %gs:XX(%reg1),%reg2  ==>  movl $YY,%reg2
2072           view[-2] = 0xc7;
2073           view[-1] = 0xc0 | ((op1 >> 3) & 7);
2074         }
2075       else if (op2 == 0x2b)
2076         {
2077           // subl %gs:XX(%reg1),%reg2  ==>  subl $YY,%reg2
2078           view[-2] = 0x81;
2079           view[-1] = 0xe8 | ((op1 >> 3) & 7);
2080         }
2081       else if (op2 == 0x03)
2082         {
2083           // addl %gs:XX(%reg1),%reg2  ==>  addl $YY,$reg2
2084           view[-2] = 0x81;
2085           view[-1] = 0xc0 | ((op1 >> 3) & 7);
2086         }
2087       else
2088         tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
2089     }
2090
2091   value = tls_segment->memsz() - value;
2092   if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE)
2093     value = - value;
2094
2095   Relocate_functions<32, false>::rel32(view, value);
2096 }
2097
2098 // Relocate section data.
2099
2100 void
2101 Target_i386::relocate_section(const Relocate_info<32, false>* relinfo,
2102                               unsigned int sh_type,
2103                               const unsigned char* prelocs,
2104                               size_t reloc_count,
2105                               Output_section* output_section,
2106                               bool needs_special_offset_handling,
2107                               unsigned char* view,
2108                               elfcpp::Elf_types<32>::Elf_Addr address,
2109                               off_t view_size)
2110 {
2111   gold_assert(sh_type == elfcpp::SHT_REL);
2112
2113   gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL,
2114                          Target_i386::Relocate>(
2115     relinfo,
2116     this,
2117     prelocs,
2118     reloc_count,
2119     output_section,
2120     needs_special_offset_handling,
2121     view,
2122     address,
2123     view_size);
2124 }
2125
2126 // Return the value to use for a dynamic which requires special
2127 // treatment.  This is how we support equality comparisons of function
2128 // pointers across shared library boundaries, as described in the
2129 // processor specific ABI supplement.
2130
2131 uint64_t
2132 Target_i386::do_dynsym_value(const Symbol* gsym) const
2133 {
2134   gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
2135   return this->plt_section()->address() + gsym->plt_offset();
2136 }
2137
2138 // Return a string used to fill a code section with nops to take up
2139 // the specified length.
2140
2141 std::string
2142 Target_i386::do_code_fill(off_t length)
2143 {
2144   if (length >= 16)
2145     {
2146       // Build a jmp instruction to skip over the bytes.
2147       unsigned char jmp[5];
2148       jmp[0] = 0xe9;
2149       elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
2150       return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
2151               + std::string(length - 5, '\0'));
2152     }
2153
2154   // Nop sequences of various lengths.
2155   const char nop1[1] = { 0x90 };                   // nop
2156   const char nop2[2] = { 0x66, 0x90 };             // xchg %ax %ax
2157   const char nop3[3] = { 0x8d, 0x76, 0x00 };       // leal 0(%esi),%esi
2158   const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00};  // leal 0(%esi,1),%esi
2159   const char nop5[5] = { 0x90, 0x8d, 0x74, 0x26,   // nop
2160                          0x00 };                   // leal 0(%esi,1),%esi
2161   const char nop6[6] = { 0x8d, 0xb6, 0x00, 0x00,   // leal 0L(%esi),%esi
2162                          0x00, 0x00 };
2163   const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00,   // leal 0L(%esi,1),%esi
2164                          0x00, 0x00, 0x00 };
2165   const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26,   // nop
2166                          0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
2167   const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc,   // movl %esi,%esi
2168                          0x27, 0x00, 0x00, 0x00,   // leal 0L(%edi,1),%edi
2169                          0x00 };
2170   const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
2171                            0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
2172                            0x00, 0x00 };
2173   const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
2174                            0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
2175                            0x00, 0x00, 0x00 };
2176   const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2177                            0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
2178                            0x00, 0x00, 0x00, 0x00 };
2179   const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2180                            0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
2181                            0x27, 0x00, 0x00, 0x00,
2182                            0x00 };
2183   const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2184                            0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
2185                            0xbc, 0x27, 0x00, 0x00,
2186                            0x00, 0x00 };
2187   const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
2188                            0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
2189                            0x90, 0x90, 0x90, 0x90,
2190                            0x90, 0x90, 0x90 };
2191
2192   const char* nops[16] = {
2193     NULL,
2194     nop1, nop2, nop3, nop4, nop5, nop6, nop7,
2195     nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
2196   };
2197
2198   return std::string(nops[length], length);
2199 }
2200
2201 // The selector for i386 object files.
2202
2203 class Target_selector_i386 : public Target_selector
2204 {
2205 public:
2206   Target_selector_i386()
2207     : Target_selector(elfcpp::EM_386, 32, false)
2208   { }
2209
2210   Target*
2211   recognize(int machine, int osabi, int abiversion);
2212
2213  private:
2214   Target_i386* target_;
2215 };
2216
2217 // Recognize an i386 object file when we already know that the machine
2218 // number is EM_386.
2219
2220 Target*
2221 Target_selector_i386::recognize(int, int, int)
2222 {
2223   if (this->target_ == NULL)
2224     this->target_ = new Target_i386();
2225   return this->target_;
2226 }
2227
2228 Target_selector_i386 target_selector_i386;
2229
2230 } // End anonymous namespace.