gold/i386.cc

   1 // i386.cc -- i386 target support for gold.
   2
   3 #include "gold.h"
   4
   5 #include <cstring>
   6
   7 #include "elfcpp.h"
   8 #include "reloc.h"
   9 #include "i386.h"
  10 #include "object.h"
  11 #include "symtab.h"
  12 #include "layout.h"
  13 #include "output.h"
  14 #include "target.h"
  15 #include "target-reloc.h"
  16 #include "target-select.h"
  17
  18 namespace
  19 {
  20
  21 using namespace gold;
  22
  23 class Output_data_plt_i386;
  24
  25 // The i386 target class.
  26
  27 class Target_i386 : public Sized_target<32, false>
  28 {
  29  public:
  30   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
  31
  32   Target_i386()
  33     : Sized_target<32, false>(&i386_info),
  34       got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
  35       copy_relocs_(NULL), dynbss_(NULL)
  36   { }
  37
  38   // Scan the relocations to look for symbol adjustments.
  39   void
  40   scan_relocs(const General_options& options,
  41               Symbol_table* symtab,
  42               Layout* layout,
  43               Sized_relobj<32, false>* object,
  44               unsigned int data_shndx,
  45               unsigned int sh_type,
  46               const unsigned char* prelocs,
  47               size_t reloc_count,
  48               size_t local_symbol_count,
  49               const unsigned char* plocal_symbols,
  50               Symbol** global_symbols);
  51
  52   // Finalize the sections.
  53   void
  54   do_finalize_sections(const General_options*, Layout*);
  55
  56   // Relocate a section.
  57   void
  58   relocate_section(const Relocate_info<32, false>*,
  59                    unsigned int sh_type,
  60                    const unsigned char* prelocs,
  61                    size_t reloc_count,
  62                    unsigned char* view,
  63                    elfcpp::Elf_types<32>::Elf_Addr view_address,
  64                    off_t view_size);
  65
  66   // Return a string used to fill a code section with nops.
  67   std::string
  68   do_code_fill(off_t length);
  69
  70  private:
  71   // The class which scans relocations.
  72   struct Scan
  73   {
  74     inline void
  75     local(const General_options& options, Symbol_table* symtab,
  76           Layout* layout, Target_i386* target,
  77           Sized_relobj<32, false>* object,
  78           unsigned int data_shndx,
  79           const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
  80           const elfcpp::Sym<32, false>& lsym);
  81
  82     inline void
  83     global(const General_options& options, Symbol_table* symtab,
  84            Layout* layout, Target_i386* target,
  85            Sized_relobj<32, false>* object,
  86            unsigned int data_shndx,
  87            const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
  88            Symbol* gsym);
  89   };
  90
  91   // The class which implements relocation.
  92   class Relocate
  93   {
  94    public:
  95     Relocate()
  96       : skip_call_tls_get_addr_(false)
  97     { }
  98
  99     ~Relocate()
 100     {
 101       if (this->skip_call_tls_get_addr_)
 102         {
 103           // FIXME: This needs to specify the location somehow.
 104           fprintf(stderr, _("%s: missing expected TLS relocation\n"),
 105                   program_name);
 106           gold_exit(false);
 107         }
 108     }
 109
 110     // Do a relocation.  Return false if the caller should not issue
 111     // any warnings about this relocation.
 112     inline bool
 113     relocate(const Relocate_info<32, false>*, Target_i386*, size_t relnum,
 114              const elfcpp::Rel<32, false>&,
 115              unsigned int r_type, const Sized_symbol<32>*,
 116              const Symbol_value<32>*,
 117              unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
 118              off_t);
 119
 120    private:
 121     // Do a TLS relocation.
 122     inline void
 123     relocate_tls(const Relocate_info<32, false>*, size_t relnum,
 124                  const elfcpp::Rel<32, false>&,
 125                  unsigned int r_type, const Sized_symbol<32>*,
 126                  const Symbol_value<32>*,
 127                  unsigned char*, elfcpp::Elf_types<32>::Elf_Addr, off_t);
 128
 129     // Do a TLS Initial-Exec to Local-Exec transition.
 130     static inline void
 131     tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum,
 132                  Output_segment* tls_segment,
 133                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 134                  elfcpp::Elf_types<32>::Elf_Addr value,
 135                  unsigned char* view,
 136                  off_t view_size);
 137
 138     // Do a TLS Global-Dynamic to Local-Exec transition.
 139     inline void
 140     tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
 141                  Output_segment* tls_segment,
 142                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 143                  elfcpp::Elf_types<32>::Elf_Addr value,
 144                  unsigned char* view,
 145                  off_t view_size);
 146
 147     // Check the range for a TLS relocation.
 148     static inline void
 149     check_range(const Relocate_info<32, false>*, size_t relnum,
 150                 const elfcpp::Rel<32, false>&, off_t, off_t);
 151
 152     // Check the validity of a TLS relocation.  This is like assert.
 153     static inline void
 154     check_tls(const Relocate_info<32, false>*, size_t relnum,
 155               const elfcpp::Rel<32, false>&, bool);
 156
 157     // This is set if we should skip the next reloc, which should be a
 158     // PLT32 reloc against ___tls_get_addr.
 159     bool skip_call_tls_get_addr_;
 160   };
 161
 162   // Adjust TLS relocation type based on the options and whether this
 163   // is a local symbol.
 164   static unsigned int
 165   optimize_tls_reloc(const General_options*, bool is_final, int r_type);
 166
 167   // Get the GOT section, creating it if necessary.
 168   Output_data_got<32, false>*
 169   got_section(const General_options*, Symbol_table*, Layout*);
 170
 171   // Create a PLT entry for a global symbol.
 172   void
 173   make_plt_entry(const General_options* options, Symbol_table*,
 174                  Layout*, Symbol*);
 175
 176   // Get the PLT section.
 177   Output_data_plt_i386*
 178   plt_section() const
 179   {
 180     gold_assert(this->plt_ != NULL);
 181     return this->plt_;
 182   }
 183
 184   // Get the dynamic reloc section, creating it if necessary.
 185   Reloc_section*
 186   rel_dyn_section(Layout*);
 187
 188   // Copy a relocation against a global symbol.
 189   void
 190   copy_reloc(const General_options*, Symbol_table*, Layout*,
 191              Sized_relobj<32, false>*, unsigned int,
 192              Symbol*, const elfcpp::Rel<32, false>&);
 193
 194   // Information about this specific target which we pass to the
 195   // general Target structure.
 196   static const Target::Target_info i386_info;
 197
 198   // The GOT section.
 199   Output_data_got<32, false>* got_;
 200   // The PLT section.
 201   Output_data_plt_i386* plt_;
 202   // The GOT PLT section.
 203   Output_data_space* got_plt_;
 204   // The dynamic reloc section.
 205   Reloc_section* rel_dyn_;
 206   // Relocs saved to avoid a COPY reloc.
 207   Copy_relocs<32, false>* copy_relocs_;
 208   // Space for variables copied with a COPY reloc.
 209   Output_data_space* dynbss_;
 210 };
 211
 212 const Target::Target_info Target_i386::i386_info =
 213 {
 214   32,                   // size
 215   false,                // is_big_endian
 216   elfcpp::EM_386,       // machine_code
 217   false,                // has_make_symbol
 218   false,                // has_resolve
 219   true,                 // has_code_fill
 220   "/usr/lib/libc.so.1", // dynamic_linker
 221   0x08048000,           // text_segment_address
 222   0x1000,               // abi_pagesize
 223   0x1000                // common_pagesize
 224 };
 225
 226 // Get the GOT section, creating it if necessary.
 227
 228 Output_data_got<32, false>*
 229 Target_i386::got_section(const General_options* options, Symbol_table* symtab,
 230                          Layout* layout)
 231 {
 232   if (this->got_ == NULL)
 233     {
 234       gold_assert(options != NULL && symtab != NULL && layout != NULL);
 235
 236       this->got_ = new Output_data_got<32, false>(options);
 237
 238       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
 239                                       elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
 240                                       this->got_);
 241
 242       // The old GNU linker creates a .got.plt section.  We just
 243       // create another set of data in the .got section.  Note that we
 244       // always create a PLT if we create a GOT, although the PLT
 245       // might be empty.
 246       this->got_plt_ = new Output_data_space(4);
 247       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
 248                                       elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
 249                                       this->got_plt_);
 250
 251       // The first three entries are reserved.
 252       this->got_plt_->set_space_size(3 * 4);
 253
 254       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
 255       symtab->define_in_output_data(this, "_GLOBAL_OFFSET_TABLE_", NULL,
 256                                     this->got_plt_,
 257                                     0, 0, elfcpp::STT_OBJECT,
 258                                     elfcpp::STB_LOCAL,
 259                                     elfcpp::STV_HIDDEN, 0,
 260                                     false, false);
 261     }
 262
 263   return this->got_;
 264 }
 265
 266 // Get the dynamic reloc section, creating it if necessary.
 267
 268 Target_i386::Reloc_section*
 269 Target_i386::rel_dyn_section(Layout* layout)
 270 {
 271   if (this->rel_dyn_ == NULL)
 272     {
 273       gold_assert(layout != NULL);
 274       this->rel_dyn_ = new Reloc_section();
 275       layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
 276                                       elfcpp::SHF_ALLOC, this->rel_dyn_);
 277     }
 278   return this->rel_dyn_;
 279 }
 280
 281 // A class to handle the PLT data.
 282
 283 class Output_data_plt_i386 : public Output_section_data
 284 {
 285  public:
 286   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
 287
 288   Output_data_plt_i386(Layout*, Output_data_space*, bool is_shared);
 289
 290   // Add an entry to the PLT.
 291   void
 292   add_entry(Symbol* gsym);
 293
 294   // Return the .rel.plt section data.
 295   const Reloc_section*
 296   rel_plt() const
 297   { return this->rel_; }
 298
 299  protected:
 300   void
 301   do_adjust_output_section(Output_section* os);
 302
 303  private:
 304   // The size of an entry in the PLT.
 305   static const int plt_entry_size = 16;
 306
 307   // The first entry in the PLT for an executable.
 308   static unsigned char exec_first_plt_entry[plt_entry_size];
 309
 310   // The first entry in the PLT for a shared object.
 311   static unsigned char dyn_first_plt_entry[plt_entry_size];
 312
 313   // Other entries in the PLT for an executable.
 314   static unsigned char exec_plt_entry[plt_entry_size];
 315
 316   // Other entries in the PLT for a shared object.
 317   static unsigned char dyn_plt_entry[plt_entry_size];
 318
 319   // Set the final size.
 320   void
 321   do_set_address(uint64_t, off_t)
 322   { this->set_data_size((this->count_ + 1) * plt_entry_size); }
 323
 324   // Write out the PLT data.
 325   void
 326   do_write(Output_file*);
 327
 328   // The reloc section.
 329   Reloc_section* rel_;
 330   // The .got.plt section.
 331   Output_data_space* got_plt_;
 332   // The number of PLT entries.
 333   unsigned int count_;
 334   // Whether we are generated a shared object.
 335   bool is_shared_;
 336 };
 337
 338 // Create the PLT section.  The ordinary .got section is an argument,
 339 // since we need to refer to the start.  We also create our own .got
 340 // section just for PLT entries.
 341
 342 Output_data_plt_i386::Output_data_plt_i386(Layout* layout,
 343                                            Output_data_space* got_plt,
 344                                            bool is_shared)
 345   : Output_section_data(4), got_plt_(got_plt), is_shared_(is_shared)
 346 {
 347   this->rel_ = new Reloc_section();
 348   layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
 349                                   elfcpp::SHF_ALLOC, this->rel_);
 350 }
 351
 352 // For some reason
 353
 354 void
 355 Output_data_plt_i386::do_adjust_output_section(Output_section* os)
 356 {
 357   // UnixWare sets the entsize of .plt to 4, and so does the old GNU
 358   // linker, and so do we.
 359   os->set_entsize(4);
 360 }
 361
 362 // Add an entry to the PLT.
 363
 364 void
 365 Output_data_plt_i386::add_entry(Symbol* gsym)
 366 {
 367   gold_assert(!gsym->has_plt_offset());
 368
 369   // Note that when setting the PLT offset we skip the initial
 370   // reserved PLT entry.
 371   gsym->set_plt_offset((this->count_ + 1) * plt_entry_size);
 372
 373   ++this->count_;
 374
 375   off_t got_offset = this->got_plt_->data_size();
 376
 377   // Every PLT entry needs a GOT entry which points back to the PLT
 378   // entry (this will be changed by the dynamic linker, normally
 379   // lazily when the function is called).
 380   this->got_plt_->set_space_size(got_offset + 4);
 381
 382   // Every PLT entry needs a reloc.
 383   gsym->set_needs_dynsym_entry();
 384   this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_,
 385                          got_offset);
 386
 387   // Note that we don't need to save the symbol.  The contents of the
 388   // PLT are independent of which symbols are used.  The symbols only
 389   // appear in the relocations.
 390 }
 391
 392 // The first entry in the PLT for an executable.
 393
 394 unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] =
 395 {
 396   0xff, 0x35,   // pushl contents of memory address
 397   0, 0, 0, 0,   // replaced with address of .got + 4
 398   0xff, 0x25,   // jmp indirect
 399   0, 0, 0, 0,   // replaced with address of .got + 8
 400   0, 0, 0, 0    // unused
 401 };
 402
 403 // The first entry in the PLT for a shared object.
 404
 405 unsigned char Output_data_plt_i386::dyn_first_plt_entry[plt_entry_size] =
 406 {
 407   0xff, 0xb3, 4, 0, 0, 0,       // pushl 4(%ebx)
 408   0xff, 0xa3, 8, 0, 0, 0,       // jmp *8(%ebx)
 409   0, 0, 0, 0                    // unused
 410 };
 411
 412 // Subsequent entries in the PLT for an executable.
 413
 414 unsigned char Output_data_plt_i386::exec_plt_entry[plt_entry_size] =
 415 {
 416   0xff, 0x25,   // jmp indirect
 417   0, 0, 0, 0,   // replaced with address of symbol in .got
 418   0x68,         // pushl immediate
 419   0, 0, 0, 0,   // replaced with offset into relocation table
 420   0xe9,         // jmp relative
 421   0, 0, 0, 0    // replaced with offset to start of .plt
 422 };
 423
 424 // Subsequent entries in the PLT for a shared object.
 425
 426 unsigned char Output_data_plt_i386::dyn_plt_entry[plt_entry_size] =
 427 {
 428   0xff, 0xa3,   // jmp *offset(%ebx)
 429   0, 0, 0, 0,   // replaced with offset of symbol in .got
 430   0x68,         // pushl immediate
 431   0, 0, 0, 0,   // replaced with offset into relocation table
 432   0xe9,         // jmp relative
 433   0, 0, 0, 0    // replaced with offset to start of .plt
 434 };
 435
 436 // Write out the PLT.  This uses the hand-coded instructions above,
 437 // and adjusts them as needed.  This is all specified by the i386 ELF
 438 // Processor Supplement.
 439
 440 void
 441 Output_data_plt_i386::do_write(Output_file* of)
 442 {
 443   const off_t offset = this->offset();
 444   const off_t oview_size = this->data_size();
 445   unsigned char* const oview = of->get_output_view(offset, oview_size);
 446
 447   const off_t got_file_offset = this->got_plt_->offset();
 448   const off_t got_size = this->got_plt_->data_size();
 449   unsigned char* const got_view = of->get_output_view(got_file_offset,
 450                                                       got_size);
 451
 452   unsigned char* pov = oview;
 453
 454   elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address();
 455   elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address();
 456
 457   if (this->is_shared_)
 458     memcpy(pov, dyn_first_plt_entry, plt_entry_size);
 459   else
 460     {
 461       memcpy(pov, exec_first_plt_entry, plt_entry_size);
 462       elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
 463       elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
 464     }
 465   pov += plt_entry_size;
 466
 467   unsigned char* got_pov = got_view;
 468
 469   memset(got_pov, 0, 12);
 470   got_pov += 12;
 471
 472   const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
 473
 474   unsigned int plt_offset = plt_entry_size;
 475   unsigned int plt_rel_offset = 0;
 476   unsigned int got_offset = 12;
 477   const unsigned int count = this->count_;
 478   for (unsigned int i = 0;
 479        i < count;
 480        ++i,
 481          pov += plt_entry_size,
 482          got_pov += 4,
 483          plt_offset += plt_entry_size,
 484          plt_rel_offset += rel_size,
 485          got_offset += 4)
 486     {
 487       // Set and adjust the PLT entry itself.
 488
 489       if (this->is_shared_)
 490         {
 491           memcpy(pov, dyn_plt_entry, plt_entry_size);
 492           elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
 493         }
 494       else
 495         {
 496           memcpy(pov, exec_plt_entry, plt_entry_size);
 497           elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
 498                                                       (got_address
 499                                                        + got_offset));
 500         }
 501
 502       elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
 503       elfcpp::Swap<32, false>::writeval(pov + 12,
 504                                         - (plt_offset + plt_entry_size));
 505
 506       // Set the entry in the GOT.
 507       elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6);
 508     }
 509
 510   gold_assert(pov - oview == oview_size);
 511   gold_assert(got_pov - got_view == got_size);
 512
 513   of->write_output_view(offset, oview_size, oview);
 514   of->write_output_view(got_file_offset, got_size, got_view);
 515 }
 516
 517 // Create a PLT entry for a global symbol.
 518
 519 void
 520 Target_i386::make_plt_entry(const General_options* options,
 521                             Symbol_table* symtab, Layout* layout, Symbol* gsym)
 522 {
 523   if (gsym->has_plt_offset())
 524     return;
 525
 526   if (this->plt_ == NULL)
 527     {
 528       // Create the GOT sections first.
 529       this->got_section(options, symtab, layout);
 530
 531       this->plt_ = new Output_data_plt_i386(layout, this->got_plt_,
 532                                             options->is_shared());
 533       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
 534                                       (elfcpp::SHF_ALLOC
 535                                        | elfcpp::SHF_EXECINSTR),
 536                                       this->plt_);
 537     }
 538
 539   this->plt_->add_entry(gsym);
 540 }
 541
 542 // Handle a relocation against a non-function symbol defined in a
 543 // dynamic object.  The traditional way to handle this is to generate
 544 // a COPY relocation to copy the variable at runtime from the shared
 545 // object into the executable's data segment.  However, this is
 546 // undesirable in general, as if the size of the object changes in the
 547 // dynamic object, the executable will no longer work correctly.  If
 548 // this relocation is in a writable section, then we can create a
 549 // dynamic reloc and the dynamic linker will resolve it to the correct
 550 // address at runtime.  However, we do not want do that if the
 551 // relocation is in a read-only section, as it would prevent the
 552 // readonly segment from being shared.  And if we have to eventually
 553 // generate a COPY reloc, then any dynamic relocations will be
 554 // useless.  So this means that if this is a writable section, we need
 555 // to save the relocation until we see whether we have to create a
 556 // COPY relocation for this symbol for any other relocation.
 557
 558 void
 559 Target_i386::copy_reloc(const General_options* options,
 560                         Symbol_table* symtab,
 561                         Layout* layout,
 562                         Sized_relobj<32, false>* object,
 563                         unsigned int data_shndx, Symbol* gsym,
 564                         const elfcpp::Rel<32, false>& rel)
 565 {
 566   Sized_symbol<32>* ssym;
 567   ssym = symtab->get_sized_symbol SELECT_SIZE_NAME(32) (gsym
 568                                                         SELECT_SIZE(32));
 569
 570   if (!Copy_relocs<32, false>::need_copy_reloc(options, object,
 571                                                data_shndx, ssym))
 572     {
 573       // So far we do not need a COPY reloc.  Save this relocation.
 574       // If it turns out that we never need a COPY reloc for this
 575       // symbol, then we will emit the relocation.
 576       if (this->copy_relocs_ == NULL)
 577         this->copy_relocs_ = new Copy_relocs<32, false>();
 578       this->copy_relocs_->save(ssym, object, data_shndx, rel);
 579     }
 580   else
 581     {
 582       // Allocate space for this symbol in the .bss section.
 583
 584       elfcpp::Elf_types<32>::Elf_WXword symsize = ssym->symsize();
 585
 586       // There is no defined way to determine the required alignment
 587       // of the symbol.  We pick the alignment based on the size.  We
 588       // set an arbitrary maximum of 256.
 589       unsigned int align;
 590       for (align = 1; align < 512; align <<= 1)
 591         if ((symsize & align) != 0)
 592           break;
 593
 594       if (this->dynbss_ == NULL)
 595         {
 596           this->dynbss_ = new Output_data_space(align);
 597           layout->add_output_section_data(".bss",
 598                                           elfcpp::SHT_NOBITS,
 599                                           (elfcpp::SHF_ALLOC
 600                                            | elfcpp::SHF_WRITE),
 601                                           this->dynbss_);
 602         }
 603
 604       Output_data_space* dynbss = this->dynbss_;
 605
 606       if (align > dynbss->addralign())
 607         dynbss->set_space_alignment(align);
 608
 609       off_t dynbss_size = dynbss->data_size();
 610       dynbss_size = align_address(dynbss_size, align);
 611       off_t offset = dynbss_size;
 612       dynbss->set_space_size(dynbss_size + symsize);
 613
 614       // Define the symbol in the .dynbss section.
 615       symtab->define_in_output_data(this, ssym->name(), ssym->version(),
 616                                     dynbss, offset, symsize, ssym->type(),
 617                                     ssym->binding(), ssym->visibility(),
 618                                     ssym->nonvis(), false, false);
 619
 620       // Add the COPY reloc.
 621       ssym->set_needs_dynsym_entry();
 622       Reloc_section* rel_dyn = this->rel_dyn_section(layout);
 623       rel_dyn->add_global(ssym, elfcpp::R_386_COPY, dynbss, offset);
 624     }
 625 }
 626
 627 // Optimize the TLS relocation type based on what we know about the
 628 // symbol.  IS_FINAL is true if the final address of this symbol is
 629 // known at link time.
 630
 631 unsigned int
 632 Target_i386::optimize_tls_reloc(const General_options* options,
 633                                 bool is_final,
 634                                 int r_type)
 635 {
 636   // If we are generating a shared library, then we can't do anything
 637   // in the linker.
 638   if (options->is_shared())
 639     return r_type;
 640
 641   switch (r_type)
 642     {
 643     case elfcpp::R_386_TLS_GD:
 644     case elfcpp::R_386_TLS_GOTDESC:
 645     case elfcpp::R_386_TLS_DESC_CALL:
 646       // These are Global-Dynamic which permits fully general TLS
 647       // access.  Since we know that we are generating an executable,
 648       // we can convert this to Initial-Exec.  If we also know that
 649       // this is a local symbol, we can further switch to Local-Exec.
 650       if (is_final)
 651         return elfcpp::R_386_TLS_LE_32;
 652       return elfcpp::R_386_TLS_IE_32;
 653
 654     case elfcpp::R_386_TLS_LDM:
 655       // This is Local-Dynamic, which refers to a local symbol in the
 656       // dynamic TLS block.  Since we know that we generating an
 657       // executable, we can switch to Local-Exec.
 658       return elfcpp::R_386_TLS_LE_32;
 659
 660     case elfcpp::R_386_TLS_LDO_32:
 661       // Another type of Local-Dynamic relocation.
 662       return elfcpp::R_386_TLS_LE;
 663
 664     case elfcpp::R_386_TLS_IE:
 665     case elfcpp::R_386_TLS_GOTIE:
 666     case elfcpp::R_386_TLS_IE_32:
 667       // These are Initial-Exec relocs which get the thread offset
 668       // from the GOT.  If we know that we are linking against the
 669       // local symbol, we can switch to Local-Exec, which links the
 670       // thread offset into the instruction.
 671       if (is_final)
 672         return elfcpp::R_386_TLS_LE_32;
 673       return r_type;
 674
 675     case elfcpp::R_386_TLS_LE:
 676     case elfcpp::R_386_TLS_LE_32:
 677       // When we already have Local-Exec, there is nothing further we
 678       // can do.
 679       return r_type;
 680
 681     default:
 682       gold_unreachable();
 683     }
 684 }
 685
 686 // Scan a relocation for a local symbol.
 687
 688 inline void
 689 Target_i386::Scan::local(const General_options& options,
 690                          Symbol_table* symtab,
 691                          Layout* layout,
 692                          Target_i386* target,
 693                          Sized_relobj<32, false>* object,
 694                          unsigned int,
 695                          const elfcpp::Rel<32, false>&,
 696                          unsigned int r_type,
 697                          const elfcpp::Sym<32, false>&)
 698 {
 699   switch (r_type)
 700     {
 701     case elfcpp::R_386_NONE:
 702     case elfcpp::R_386_GNU_VTINHERIT:
 703     case elfcpp::R_386_GNU_VTENTRY:
 704       break;
 705
 706     case elfcpp::R_386_32:
 707     case elfcpp::R_386_16:
 708     case elfcpp::R_386_8:
 709       // FIXME: If we are generating a shared object we need to copy
 710       // this relocation into the object.
 711       gold_assert(!options.is_shared());
 712       break;
 713
 714     case elfcpp::R_386_PC32:
 715     case elfcpp::R_386_PC16:
 716     case elfcpp::R_386_PC8:
 717       break;
 718
 719     case elfcpp::R_386_GOTOFF:
 720     case elfcpp::R_386_GOTPC:
 721       // We need a GOT section.
 722       target->got_section(&options, symtab, layout);
 723       break;
 724
 725     case elfcpp::R_386_COPY:
 726     case elfcpp::R_386_GLOB_DAT:
 727     case elfcpp::R_386_JUMP_SLOT:
 728     case elfcpp::R_386_RELATIVE:
 729     case elfcpp::R_386_TLS_TPOFF:
 730     case elfcpp::R_386_TLS_DTPMOD32:
 731     case elfcpp::R_386_TLS_DTPOFF32:
 732     case elfcpp::R_386_TLS_TPOFF32:
 733     case elfcpp::R_386_TLS_DESC:
 734       fprintf(stderr, _("%s: %s: unexpected reloc %u in object file\n"),
 735               program_name, object->name().c_str(), r_type);
 736       gold_exit(false);
 737       break;
 738
 739     case elfcpp::R_386_TLS_IE:
 740     case elfcpp::R_386_TLS_GOTIE:
 741     case elfcpp::R_386_TLS_LE:
 742     case elfcpp::R_386_TLS_GD:
 743     case elfcpp::R_386_TLS_LDM:
 744     case elfcpp::R_386_TLS_LDO_32:
 745     case elfcpp::R_386_TLS_IE_32:
 746     case elfcpp::R_386_TLS_LE_32:
 747     case elfcpp::R_386_TLS_GOTDESC:
 748     case elfcpp::R_386_TLS_DESC_CALL:
 749       r_type = Target_i386::optimize_tls_reloc(&options,
 750                                                !options.is_shared(),
 751                                                r_type);
 752       switch (r_type)
 753         {
 754         case elfcpp::R_386_TLS_LE:
 755         case elfcpp::R_386_TLS_LE_32:
 756           // FIXME: If generating a shared object, we need to copy
 757           // this relocation into the object.
 758           gold_assert(!options.is_shared());
 759           break;
 760
 761         case elfcpp::R_386_TLS_IE:
 762         case elfcpp::R_386_TLS_GOTIE:
 763         case elfcpp::R_386_TLS_GD:
 764         case elfcpp::R_386_TLS_LDM:
 765         case elfcpp::R_386_TLS_LDO_32:
 766         case elfcpp::R_386_TLS_IE_32:
 767         case elfcpp::R_386_TLS_GOTDESC:
 768         case elfcpp::R_386_TLS_DESC_CALL:
 769           fprintf(stderr,
 770                   _("%s: %s: unsupported reloc %u against local symbol\n"),
 771                   program_name, object->name().c_str(), r_type);
 772           break;
 773         }
 774       break;
 775
 776     case elfcpp::R_386_GOT32:
 777     case elfcpp::R_386_PLT32:
 778     case elfcpp::R_386_32PLT:
 779     case elfcpp::R_386_TLS_GD_32:
 780     case elfcpp::R_386_TLS_GD_PUSH:
 781     case elfcpp::R_386_TLS_GD_CALL:
 782     case elfcpp::R_386_TLS_GD_POP:
 783     case elfcpp::R_386_TLS_LDM_32:
 784     case elfcpp::R_386_TLS_LDM_PUSH:
 785     case elfcpp::R_386_TLS_LDM_CALL:
 786     case elfcpp::R_386_TLS_LDM_POP:
 787     case elfcpp::R_386_USED_BY_INTEL_200:
 788     default:
 789       fprintf(stderr, _("%s: %s: unsupported reloc %u against local symbol\n"),
 790               program_name, object->name().c_str(), r_type);
 791       break;
 792     }
 793 }
 794
 795 // Scan a relocation for a global symbol.
 796
 797 inline void
 798 Target_i386::Scan::global(const General_options& options,
 799                           Symbol_table* symtab,
 800                           Layout* layout,
 801                           Target_i386* target,
 802                           Sized_relobj<32, false>* object,
 803                           unsigned int data_shndx,
 804                           const elfcpp::Rel<32, false>& reloc,
 805                           unsigned int r_type,
 806                           Symbol* gsym)
 807 {
 808   switch (r_type)
 809     {
 810     case elfcpp::R_386_NONE:
 811     case elfcpp::R_386_GNU_VTINHERIT:
 812     case elfcpp::R_386_GNU_VTENTRY:
 813       break;
 814
 815     case elfcpp::R_386_32:
 816     case elfcpp::R_386_PC32:
 817     case elfcpp::R_386_16:
 818     case elfcpp::R_386_PC16:
 819     case elfcpp::R_386_8:
 820     case elfcpp::R_386_PC8:
 821       // FIXME: If we are generating a shared object we may need to
 822       // copy this relocation into the object.  If this symbol is
 823       // defined in a shared object, we may need to copy this
 824       // relocation in order to avoid a COPY relocation.
 825       gold_assert(!options.is_shared());
 826
 827       if (gsym->is_from_dynobj())
 828         {
 829           // This symbol is defined in a dynamic object.  If it is a
 830           // function, we make a PLT entry.  Otherwise we need to
 831           // either generate a COPY reloc or copy this reloc.
 832           if (gsym->type() == elfcpp::STT_FUNC)
 833             target->make_plt_entry(&options, symtab, layout, gsym);
 834           else
 835             target->copy_reloc(&options, symtab, layout, object, data_shndx,
 836                                gsym, reloc);
 837         }
 838
 839       break;
 840
 841     case elfcpp::R_386_GOT32:
 842       {
 843         // The symbol requires a GOT entry.
 844         Output_data_got<32, false>* got = target->got_section(&options, symtab,
 845                                                               layout);
 846         if (got->add_global(gsym))
 847           {
 848             // If this symbol is not fully resolved, we need to add a
 849             // dynamic relocation for it.
 850             if (!gsym->final_value_is_known(&options))
 851               {
 852                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
 853                 rel_dyn->add_global(gsym, elfcpp::R_386_GLOB_DAT, got,
 854                                     gsym->got_offset());
 855               }
 856           }
 857       }
 858       break;
 859
 860     case elfcpp::R_386_PLT32:
 861       // If the symbol is fully resolved, this is just a PC32 reloc.
 862       // Otherwise we need a PLT entry.
 863       if (gsym->final_value_is_known(&options))
 864         break;
 865       target->make_plt_entry(&options, symtab, layout, gsym);
 866       break;
 867
 868     case elfcpp::R_386_GOTOFF:
 869     case elfcpp::R_386_GOTPC:
 870       // We need a GOT section.
 871       target->got_section(&options, symtab, layout);
 872       break;
 873
 874     case elfcpp::R_386_COPY:
 875     case elfcpp::R_386_GLOB_DAT:
 876     case elfcpp::R_386_JUMP_SLOT:
 877     case elfcpp::R_386_RELATIVE:
 878     case elfcpp::R_386_TLS_TPOFF:
 879     case elfcpp::R_386_TLS_DTPMOD32:
 880     case elfcpp::R_386_TLS_DTPOFF32:
 881     case elfcpp::R_386_TLS_TPOFF32:
 882     case elfcpp::R_386_TLS_DESC:
 883       fprintf(stderr, _("%s: %s: unexpected reloc %u in object file\n"),
 884               program_name, object->name().c_str(), r_type);
 885       gold_exit(false);
 886       break;
 887
 888     case elfcpp::R_386_TLS_IE:
 889     case elfcpp::R_386_TLS_GOTIE:
 890     case elfcpp::R_386_TLS_LE:
 891     case elfcpp::R_386_TLS_GD:
 892     case elfcpp::R_386_TLS_LDM:
 893     case elfcpp::R_386_TLS_LDO_32:
 894     case elfcpp::R_386_TLS_IE_32:
 895     case elfcpp::R_386_TLS_LE_32:
 896     case elfcpp::R_386_TLS_GOTDESC:
 897     case elfcpp::R_386_TLS_DESC_CALL:
 898       {
 899         const bool is_final = gsym->final_value_is_known(&options);
 900         r_type = Target_i386::optimize_tls_reloc(&options, is_final, r_type);
 901         switch (r_type)
 902           {
 903           case elfcpp::R_386_TLS_LE:
 904           case elfcpp::R_386_TLS_LE_32:
 905             // FIXME: If generating a shared object, we need to copy
 906             // this relocation into the object.
 907             gold_assert(!options.is_shared());
 908             break;
 909
 910           case elfcpp::R_386_TLS_IE:
 911           case elfcpp::R_386_TLS_GOTIE:
 912           case elfcpp::R_386_TLS_GD:
 913           case elfcpp::R_386_TLS_LDM:
 914           case elfcpp::R_386_TLS_LDO_32:
 915           case elfcpp::R_386_TLS_IE_32:
 916           case elfcpp::R_386_TLS_GOTDESC:
 917           case elfcpp::R_386_TLS_DESC_CALL:
 918             fprintf(stderr,
 919                     _("%s: %s: unsupported reloc %u "
 920                       "against global symbol %s\n"),
 921                     program_name, object->name().c_str(), r_type,
 922                     gsym->name());
 923             break;
 924           }
 925       }
 926       break;
 927
 928     case elfcpp::R_386_32PLT:
 929     case elfcpp::R_386_TLS_GD_32:
 930     case elfcpp::R_386_TLS_GD_PUSH:
 931     case elfcpp::R_386_TLS_GD_CALL:
 932     case elfcpp::R_386_TLS_GD_POP:
 933     case elfcpp::R_386_TLS_LDM_32:
 934     case elfcpp::R_386_TLS_LDM_PUSH:
 935     case elfcpp::R_386_TLS_LDM_CALL:
 936     case elfcpp::R_386_TLS_LDM_POP:
 937     case elfcpp::R_386_USED_BY_INTEL_200:
 938     default:
 939       fprintf(stderr,
 940               _("%s: %s: unsupported reloc %u against global symbol %s\n"),
 941               program_name, object->name().c_str(), r_type, gsym->name());
 942       break;
 943     }
 944 }
 945
 946 // Scan relocations for a section.
 947
 948 void
 949 Target_i386::scan_relocs(const General_options& options,
 950                          Symbol_table* symtab,
 951                          Layout* layout,
 952                          Sized_relobj<32, false>* object,
 953                          unsigned int data_shndx,
 954                          unsigned int sh_type,
 955                          const unsigned char* prelocs,
 956                          size_t reloc_count,
 957                          size_t local_symbol_count,
 958                          const unsigned char* plocal_symbols,
 959                          Symbol** global_symbols)
 960 {
 961   if (sh_type == elfcpp::SHT_RELA)
 962     {
 963       fprintf(stderr, _("%s: %s: unsupported RELA reloc section\n"),
 964               program_name, object->name().c_str());
 965       gold_exit(false);
 966     }
 967
 968   gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL,
 969                     Target_i386::Scan>(
 970     options,
 971     symtab,
 972     layout,
 973     this,
 974     object,
 975     data_shndx,
 976     prelocs,
 977     reloc_count,
 978     local_symbol_count,
 979     plocal_symbols,
 980     global_symbols);
 981 }
 982
 983 // Finalize the sections.
 984
 985 void
 986 Target_i386::do_finalize_sections(const General_options* options,
 987                                   Layout* layout)
 988 {
 989   // Fill in some more dynamic tags.
 990   Output_data_dynamic* const odyn = layout->dynamic_data();
 991   if (odyn != NULL)
 992     {
 993       if (this->got_plt_ != NULL)
 994         odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_);
 995
 996       if (this->plt_ != NULL)
 997         {
 998           const Output_data* od = this->plt_->rel_plt();
 999           odyn->add_section_size(elfcpp::DT_PLTRELSZ, od);
1000           odyn->add_section_address(elfcpp::DT_JMPREL, od);
1001           odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_REL);
1002         }
1003
1004       if (this->rel_dyn_ != NULL)
1005         {
1006           const Output_data* od = this->rel_dyn_;
1007           odyn->add_section_address(elfcpp::DT_REL, od);
1008           odyn->add_section_size(elfcpp::DT_RELSZ, od);
1009           odyn->add_constant(elfcpp::DT_RELENT,
1010                              elfcpp::Elf_sizes<32>::rel_size);
1011         }
1012
1013       if (!options->is_shared())
1014         {
1015           // The value of the DT_DEBUG tag is filled in by the dynamic
1016           // linker at run time, and used by the debugger.
1017           odyn->add_constant(elfcpp::DT_DEBUG, 0);
1018         }
1019     }
1020
1021   // Emit any relocs we saved in an attempt to avoid generating COPY
1022   // relocs.
1023   if (this->copy_relocs_ == NULL)
1024     return;
1025   if (this->copy_relocs_->any_to_emit())
1026     {
1027       Reloc_section* rel_dyn = this->rel_dyn_section(layout);
1028       this->copy_relocs_->emit(rel_dyn);
1029     }
1030   delete this->copy_relocs_;
1031   this->copy_relocs_ = NULL;
1032 }
1033
1034 // Perform a relocation.
1035
1036 inline bool
1037 Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
1038                                 Target_i386* target,
1039                                 size_t relnum,
1040                                 const elfcpp::Rel<32, false>& rel,
1041                                 unsigned int r_type,
1042                                 const Sized_symbol<32>* gsym,
1043                                 const Symbol_value<32>* psymval,
1044                                 unsigned char* view,
1045                                 elfcpp::Elf_types<32>::Elf_Addr address,
1046                                 off_t view_size)
1047 {
1048   if (this->skip_call_tls_get_addr_)
1049     {
1050       if (r_type != elfcpp::R_386_PLT32
1051           || gsym == NULL
1052           || strcmp(gsym->name(), "___tls_get_addr") != 0)
1053         {
1054           fprintf(stderr, _("%s: %s: missing expected TLS relocation\n"),
1055                   program_name,
1056                   relinfo->location(relnum, rel.get_r_offset()).c_str());
1057           gold_exit(false);
1058         }
1059
1060       this->skip_call_tls_get_addr_ = false;
1061
1062       return false;
1063     }
1064
1065   // Pick the value to use for symbols defined in shared objects.
1066   Symbol_value<32> symval;
1067   if (gsym != NULL && gsym->is_from_dynobj() && gsym->has_plt_offset())
1068     {
1069       symval.set_output_value(target->plt_section()->address()
1070                               + gsym->plt_offset());
1071       psymval = &symval;
1072     }
1073
1074   const Sized_relobj<32, false>* object = relinfo->object;
1075
1076   switch (r_type)
1077     {
1078     case elfcpp::R_386_NONE:
1079     case elfcpp::R_386_GNU_VTINHERIT:
1080     case elfcpp::R_386_GNU_VTENTRY:
1081       break;
1082
1083     case elfcpp::R_386_32:
1084       Relocate_functions<32, false>::rel32(view, object, psymval);
1085       break;
1086
1087     case elfcpp::R_386_PC32:
1088       Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1089       break;
1090
1091     case elfcpp::R_386_16:
1092       Relocate_functions<32, false>::rel16(view, object, psymval);
1093       break;
1094
1095     case elfcpp::R_386_PC16:
1096       Relocate_functions<32, false>::pcrel16(view, object, psymval, address);
1097       break;
1098
1099     case elfcpp::R_386_8:
1100       Relocate_functions<32, false>::rel8(view, object, psymval);
1101       break;
1102
1103     case elfcpp::R_386_PC8:
1104       Relocate_functions<32, false>::pcrel8(view, object, psymval, address);
1105       break;
1106
1107     case elfcpp::R_386_PLT32:
1108       gold_assert(gsym->has_plt_offset()
1109                   || gsym->final_value_is_known(relinfo->options));
1110       Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1111       break;
1112
1113     case elfcpp::R_386_GOT32:
1114       // Local GOT offsets not yet supported.
1115       gold_assert(gsym);
1116       gold_assert(gsym->has_got_offset());
1117       Relocate_functions<32, false>::rel32(view, gsym->got_offset());
1118       break;
1119
1120     case elfcpp::R_386_GOTOFF:
1121       {
1122         elfcpp::Elf_types<32>::Elf_Addr value;
1123         value = (psymval->value(object, 0)
1124                  - target->got_section(NULL, NULL, NULL)->address());
1125         Relocate_functions<32, false>::rel32(view, value);
1126       }
1127       break;
1128
1129     case elfcpp::R_386_GOTPC:
1130       {
1131         elfcpp::Elf_types<32>::Elf_Addr value;
1132         value = target->got_section(NULL, NULL, NULL)->address();
1133         Relocate_functions<32, false>::pcrel32(view, value, address);
1134       }
1135       break;
1136
1137     case elfcpp::R_386_COPY:
1138     case elfcpp::R_386_GLOB_DAT:
1139     case elfcpp::R_386_JUMP_SLOT:
1140     case elfcpp::R_386_RELATIVE:
1141     case elfcpp::R_386_TLS_TPOFF:
1142     case elfcpp::R_386_TLS_DTPMOD32:
1143     case elfcpp::R_386_TLS_DTPOFF32:
1144     case elfcpp::R_386_TLS_TPOFF32:
1145     case elfcpp::R_386_TLS_DESC:
1146       fprintf(stderr, _("%s: %s: unexpected reloc %u in object file\n"),
1147               program_name,
1148               relinfo->location(relnum, rel.get_r_offset()).c_str(),
1149               r_type);
1150       gold_exit(false);
1151       break;
1152
1153     case elfcpp::R_386_TLS_IE:
1154     case elfcpp::R_386_TLS_GOTIE:
1155     case elfcpp::R_386_TLS_LE:
1156     case elfcpp::R_386_TLS_GD:
1157     case elfcpp::R_386_TLS_LDM:
1158     case elfcpp::R_386_TLS_LDO_32:
1159     case elfcpp::R_386_TLS_IE_32:
1160     case elfcpp::R_386_TLS_LE_32:
1161     case elfcpp::R_386_TLS_GOTDESC:
1162     case elfcpp::R_386_TLS_DESC_CALL:
1163       this->relocate_tls(relinfo, relnum, rel, r_type, gsym, psymval, view,
1164                          address, view_size);
1165       break;
1166
1167     case elfcpp::R_386_32PLT:
1168     case elfcpp::R_386_TLS_GD_32:
1169     case elfcpp::R_386_TLS_GD_PUSH:
1170     case elfcpp::R_386_TLS_GD_CALL:
1171     case elfcpp::R_386_TLS_GD_POP:
1172     case elfcpp::R_386_TLS_LDM_32:
1173     case elfcpp::R_386_TLS_LDM_PUSH:
1174     case elfcpp::R_386_TLS_LDM_CALL:
1175     case elfcpp::R_386_TLS_LDM_POP:
1176     case elfcpp::R_386_USED_BY_INTEL_200:
1177     default:
1178       fprintf(stderr, _("%s: %s: unsupported reloc %u\n"),
1179               program_name,
1180               relinfo->location(relnum, rel.get_r_offset()).c_str(),
1181               r_type);
1182       // gold_exit(false);
1183       break;
1184     }
1185
1186   return true;
1187 }
1188
1189 // Perform a TLS relocation.
1190
1191 inline void
1192 Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo,
1193                                     size_t relnum,
1194                                     const elfcpp::Rel<32, false>& rel,
1195                                     unsigned int r_type,
1196                                     const Sized_symbol<32>* gsym,
1197                                     const Symbol_value<32>* psymval,
1198                                     unsigned char* view,
1199                                     elfcpp::Elf_types<32>::Elf_Addr,
1200                                     off_t view_size)
1201 {
1202   Output_segment* tls_segment = relinfo->layout->tls_segment();
1203   if (tls_segment == NULL)
1204     {
1205       fprintf(stderr, _("%s: %s: TLS reloc but no TLS segment\n"),
1206               program_name,
1207               relinfo->location(relnum, rel.get_r_offset()).c_str());
1208       gold_exit(false);
1209     }
1210
1211   elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(relinfo->object, 0);
1212
1213   const bool is_final = (gsym == NULL
1214                          ? !relinfo->options->is_shared()
1215                          : gsym->final_value_is_known(relinfo->options));
1216   const unsigned int opt_r_type =
1217     Target_i386::optimize_tls_reloc(relinfo->options, is_final, r_type);
1218   switch (r_type)
1219     {
1220     case elfcpp::R_386_TLS_LE_32:
1221       value = tls_segment->vaddr() + tls_segment->memsz() - value;
1222       Relocate_functions<32, false>::rel32(view, value);
1223       break;
1224
1225     case elfcpp::R_386_TLS_LE:
1226       value = value - (tls_segment->vaddr() + tls_segment->memsz());
1227       Relocate_functions<32, false>::rel32(view, value);
1228       break;
1229
1230     case elfcpp::R_386_TLS_IE:
1231     case elfcpp::R_386_TLS_GOTIE:
1232     case elfcpp::R_386_TLS_IE_32:
1233       if (opt_r_type == elfcpp::R_386_TLS_LE_32)
1234         {
1235           Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
1236                                               rel, r_type, value, view,
1237                                               view_size);
1238           break;
1239         }
1240       fprintf(stderr, _("%s: %s: unsupported reloc type %u\n"),
1241               program_name,
1242               relinfo->location(relnum, rel.get_r_offset()).c_str(),
1243               r_type);
1244       // gold_exit(false);
1245       break;
1246
1247     case elfcpp::R_386_TLS_GD:
1248       if (opt_r_type == elfcpp::R_386_TLS_LE_32)
1249         {
1250           this->tls_gd_to_le(relinfo, relnum, tls_segment,
1251                              rel, r_type, value, view,
1252                              view_size);
1253           break;
1254         }
1255       fprintf(stderr, _("%s: %s: unsupported reloc %u\n"),
1256               program_name,
1257               relinfo->location(relnum, rel.get_r_offset()).c_str(),
1258               r_type);
1259       // gold_exit(false);
1260       break;
1261
1262     case elfcpp::R_386_TLS_LDM:
1263     case elfcpp::R_386_TLS_LDO_32:
1264     case elfcpp::R_386_TLS_GOTDESC:
1265     case elfcpp::R_386_TLS_DESC_CALL:
1266       fprintf(stderr, _("%s: %s: unsupported reloc %u\n"),
1267               program_name,
1268               relinfo->location(relnum, rel.get_r_offset()).c_str(),
1269               r_type);
1270       // gold_exit(false);
1271       break;
1272     }
1273 }
1274
1275 // Do a relocation in which we convert a TLS Initial-Exec to a
1276 // Local-Exec.
1277
1278 inline void
1279 Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo,
1280                                     size_t relnum,
1281                                     Output_segment* tls_segment,
1282                                     const elfcpp::Rel<32, false>& rel,
1283                                     unsigned int r_type,
1284                                     elfcpp::Elf_types<32>::Elf_Addr value,
1285                                     unsigned char* view,
1286                                     off_t view_size)
1287 {
1288   // We have to actually change the instructions, which means that we
1289   // need to examine the opcodes to figure out which instruction we
1290   // are looking at.
1291   if (r_type == elfcpp::R_386_TLS_IE)
1292     {
1293       // movl %gs:XX,%eax  ==>  movl $YY,%eax
1294       // movl %gs:XX,%reg  ==>  movl $YY,%reg
1295       // addl %gs:XX,%reg  ==>  addl $YY,%reg
1296       Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, -1);
1297       Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, 4);
1298
1299       unsigned char op1 = view[-1];
1300       if (op1 == 0xa1)
1301         {
1302           // movl XX,%eax  ==>  movl $YY,%eax
1303           view[-1] = 0xb8;
1304         }
1305       else
1306         {
1307           Target_i386::Relocate::check_range(relinfo, relnum, rel,
1308                                              view_size, -2);
1309
1310           unsigned char op2 = view[-2];
1311           if (op2 == 0x8b)
1312             {
1313               // movl XX,%reg  ==>  movl $YY,%reg
1314               Target_i386::Relocate::check_tls(relinfo, relnum, rel,
1315                                                (op1 & 0xc7) == 0x05);
1316               view[-2] = 0xc7;
1317               view[-1] = 0xc0 | ((op1 >> 3) & 7);
1318             }
1319           else if (op2 == 0x03)
1320             {
1321               // addl XX,%reg  ==>  addl $YY,%reg
1322               Target_i386::Relocate::check_tls(relinfo, relnum, rel,
1323                                                (op1 & 0xc7) == 0x05);
1324               view[-2] = 0x81;
1325               view[-1] = 0xc0 | ((op1 >> 3) & 7);
1326             }
1327           else
1328             Target_i386::Relocate::check_tls(relinfo, relnum, rel, 0);
1329         }
1330     }
1331   else
1332     {
1333       // subl %gs:XX(%reg1),%reg2  ==>  subl $YY,%reg2
1334       // movl %gs:XX(%reg1),%reg2  ==>  movl $YY,%reg2
1335       // addl %gs:XX(%reg1),%reg2  ==>  addl $YY,$reg2
1336       Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, -2);
1337       Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, 4);
1338
1339       unsigned char op1 = view[-1];
1340       unsigned char op2 = view[-2];
1341       Target_i386::Relocate::check_tls(relinfo, relnum, rel,
1342                                        (op1 & 0xc0) == 0x80 && (op1 & 7) != 4);
1343       if (op2 == 0x8b)
1344         {
1345           // movl %gs:XX(%reg1),%reg2  ==>  movl $YY,%reg2
1346           view[-2] = 0xc7;
1347           view[-1] = 0xc0 | ((op1 >> 3) & 7);
1348         }
1349       else if (op2 == 0x2b)
1350         {
1351           // subl %gs:XX(%reg1),%reg2  ==>  subl $YY,%reg2
1352           view[-2] = 0x81;
1353           view[-1] = 0xe8 | ((op1 >> 3) & 7);
1354         }
1355       else if (op2 == 0x03)
1356         {
1357           // addl %gs:XX(%reg1),%reg2  ==>  addl $YY,$reg2
1358           view[-2] = 0x81;
1359           view[-1] = 0xc0 | ((op1 >> 3) & 7);
1360         }
1361       else
1362         Target_i386::Relocate::check_tls(relinfo, relnum, rel, 0);
1363     }
1364
1365   value = tls_segment->vaddr() + tls_segment->memsz() - value;
1366   if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE)
1367     value = - value;
1368
1369   Relocate_functions<32, false>::rel32(view, value);
1370 }
1371
1372 // Do a relocation in which we convert a TLS Global-Dynamic to a
1373 // Local-Exec.
1374
1375 inline void
1376 Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo,
1377                                     size_t relnum,
1378                                     Output_segment* tls_segment,
1379                                     const elfcpp::Rel<32, false>& rel,
1380                                     unsigned int,
1381                                     elfcpp::Elf_types<32>::Elf_Addr value,
1382                                     unsigned char* view,
1383                                     off_t view_size)
1384 {
1385   // leal foo(,%reg,1),%eax; call ___tls_get_addr
1386   //  ==> movl %gs,0,%eax; subl $foo@tpoff,%eax
1387   // leal foo(%reg),%eax; call ___tls_get_addr
1388   //  ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
1389
1390   Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, -2);
1391   Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, 9);
1392
1393   unsigned char op1 = view[-1];
1394   unsigned char op2 = view[-2];
1395
1396   Target_i386::Relocate::check_tls(relinfo, relnum, rel,
1397                                    op2 == 0x8d || op2 == 0x04);
1398   Target_i386::Relocate::check_tls(relinfo, relnum, rel,
1399                                    view[4] == 0xe8);
1400
1401   int roff = 5;
1402
1403   if (op2 == 0x04)
1404     {
1405       Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, -3);
1406       Target_i386::Relocate::check_tls(relinfo, relnum, rel,
1407                                        view[-3] == 0x8d);
1408       Target_i386::Relocate::check_tls(relinfo, relnum, rel,
1409                                        ((op1 & 0xc7) == 0x05
1410                                         && op1 != (4 << 3)));
1411       memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
1412     }
1413   else
1414     {
1415       Target_i386::Relocate::check_tls(relinfo, relnum, rel,
1416                                        (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
1417       if (rel.get_r_offset() + 9 < view_size && view[9] == 0x90)
1418         {
1419           // There is a trailing nop.  Use the size byte subl.
1420           memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
1421           roff = 6;
1422         }
1423       else
1424         {
1425           // Use the five byte subl.
1426           memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
1427         }
1428     }
1429
1430   value = tls_segment->vaddr() + tls_segment->memsz() - value;
1431   Relocate_functions<32, false>::rel32(view + roff, value);
1432
1433   // The next reloc should be a PLT32 reloc against __tls_get_addr.
1434   // We can skip it.
1435   this->skip_call_tls_get_addr_ = true;
1436 }
1437
1438 // Check the range for a TLS relocation.
1439
1440 inline void
1441 Target_i386::Relocate::check_range(const Relocate_info<32, false>* relinfo,
1442                                    size_t relnum,
1443                                    const elfcpp::Rel<32, false>& rel,
1444                                    off_t view_size, off_t off)
1445 {
1446   off_t offset = rel.get_r_offset() + off;
1447   if (offset < 0 || offset > view_size)
1448     {
1449       fprintf(stderr, _("%s: %s: TLS relocation out of range\n"),
1450               program_name,
1451               relinfo->location(relnum, rel.get_r_offset()).c_str());
1452       gold_exit(false);
1453     }
1454 }
1455
1456 // Check the validity of a TLS relocation.  This is like assert.
1457
1458 inline void
1459 Target_i386::Relocate::check_tls(const Relocate_info<32, false>* relinfo,
1460                                  size_t relnum,
1461                                  const elfcpp::Rel<32, false>& rel,
1462                                  bool valid)
1463 {
1464   if (!valid)
1465     {
1466       fprintf(stderr,
1467               _("%s: %s: TLS relocation against invalid instruction\n"),
1468               program_name,
1469               relinfo->location(relnum, rel.get_r_offset()).c_str());
1470       gold_exit(false);
1471     }
1472 }
1473
1474 // Relocate section data.
1475
1476 void
1477 Target_i386::relocate_section(const Relocate_info<32, false>* relinfo,
1478                               unsigned int sh_type,
1479                               const unsigned char* prelocs,
1480                               size_t reloc_count,
1481                               unsigned char* view,
1482                               elfcpp::Elf_types<32>::Elf_Addr address,
1483                               off_t view_size)
1484 {
1485   gold_assert(sh_type == elfcpp::SHT_REL);
1486
1487   gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL,
1488                          Target_i386::Relocate>(
1489     relinfo,
1490     this,
1491     prelocs,
1492     reloc_count,
1493     view,
1494     address,
1495     view_size);
1496 }
1497
1498 // Return a string used to fill a code section with nops to take up
1499 // the specified length.
1500
1501 std::string
1502 Target_i386::do_code_fill(off_t length)
1503 {
1504   if (length >= 16)
1505     {
1506       // Build a jmp instruction to skip over the bytes.
1507       unsigned char jmp[5];
1508       jmp[0] = 0xe9;
1509       elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
1510       return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
1511               + std::string(length - 5, '\0'));
1512     }
1513
1514   // Nop sequences of various lengths.
1515   const char nop1[1] = { 0x90 };                   // nop
1516   const char nop2[2] = { 0x66, 0x90 };             // xchg %ax %ax
1517   const char nop3[3] = { 0x8d, 0x76, 0x00 };       // leal 0(%esi),%esi
1518   const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00};  // leal 0(%esi,1),%esi
1519   const char nop5[5] = { 0x90, 0x8d, 0x74, 0x26,   // nop
1520                          0x00 };                   // leal 0(%esi,1),%esi
1521   const char nop6[6] = { 0x8d, 0xb6, 0x00, 0x00,   // leal 0L(%esi),%esi
1522                          0x00, 0x00 };
1523   const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00,   // leal 0L(%esi,1),%esi
1524                          0x00, 0x00, 0x00 };
1525   const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26,   // nop
1526                          0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
1527   const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc,   // movl %esi,%esi
1528                          0x27, 0x00, 0x00, 0x00,   // leal 0L(%edi,1),%edi
1529                          0x00 };
1530   const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
1531                            0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
1532                            0x00, 0x00 };
1533   const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
1534                            0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
1535                            0x00, 0x00, 0x00 };
1536   const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
1537                            0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
1538                            0x00, 0x00, 0x00, 0x00 };
1539   const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
1540                            0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
1541                            0x27, 0x00, 0x00, 0x00,
1542                            0x00 };
1543   const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
1544                            0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
1545                            0xbc, 0x27, 0x00, 0x00,
1546                            0x00, 0x00 };
1547   const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
1548                            0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
1549                            0x90, 0x90, 0x90, 0x90,
1550                            0x90, 0x90, 0x90 };
1551
1552   const char* nops[16] = {
1553     NULL,
1554     nop1, nop2, nop3, nop4, nop5, nop6, nop7,
1555     nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
1556   };
1557
1558   return std::string(nops[length], length);
1559 }
1560
1561 // The selector for i386 object files.
1562
1563 class Target_selector_i386 : public Target_selector
1564 {
1565 public:
1566   Target_selector_i386()
1567     : Target_selector(elfcpp::EM_386, 32, false)
1568   { }
1569
1570   Target*
1571   recognize(int machine, int osabi, int abiversion);
1572
1573  private:
1574   Target_i386* target_;
1575 };
1576
1577 // Recognize an i386 object file when we already know that the machine
1578 // number is EM_386.
1579
1580 Target*
1581 Target_selector_i386::recognize(int, int, int)
1582 {
1583   if (this->target_ == NULL)
1584     this->target_ = new Target_i386();
1585   return this->target_;
1586 }
1587
1588 Target_selector_i386 target_selector_i386;
1589
1590 } // End anonymous namespace.