gold/i386.cc

   1 // i386.cc -- i386 target support for gold.
   2
   3 // Copyright 2006, 2007, 2008, 2009 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 "copy-relocs.h"
  36 #include "target.h"
  37 #include "target-reloc.h"
  38 #include "target-select.h"
  39 #include "tls.h"
  40 #include "freebsd.h"
  41
  42 namespace
  43 {
  44
  45 using namespace gold;
  46
  47 class Output_data_plt_i386;
  48
  49 // The i386 target class.
  50 // TLS info comes from
  51 //   http://people.redhat.com/drepper/tls.pdf
  52 //   http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
  53
  54 class Target_i386 : public Target_freebsd<32, false>
  55 {
  56  public:
  57   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
  58
  59   Target_i386()
  60     : Target_freebsd<32, false>(&i386_info),
  61       got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
  62       copy_relocs_(elfcpp::R_386_COPY), dynbss_(NULL),
  63       got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
  64   { }
  65
  66   // Process the relocations to determine unreferenced sections for
  67   // garbage collection.
  68   void
  69   gc_process_relocs(const General_options& options,
  70                     Symbol_table* symtab,
  71                     Layout* layout,
  72                     Sized_relobj<32, false>* object,
  73                     unsigned int data_shndx,
  74                     unsigned int sh_type,
  75                     const unsigned char* prelocs,
  76                     size_t reloc_count,
  77                     Output_section* output_section,
  78                     bool needs_special_offset_handling,
  79                     size_t local_symbol_count,
  80                     const unsigned char* plocal_symbols);
  81
  82   // Scan the relocations to look for symbol adjustments.
  83   void
  84   scan_relocs(const General_options& options,
  85               Symbol_table* symtab,
  86               Layout* layout,
  87               Sized_relobj<32, false>* object,
  88               unsigned int data_shndx,
  89               unsigned int sh_type,
  90               const unsigned char* prelocs,
  91               size_t reloc_count,
  92               Output_section* output_section,
  93               bool needs_special_offset_handling,
  94               size_t local_symbol_count,
  95               const unsigned char* plocal_symbols);
  96
  97   // Finalize the sections.
  98   void
  99   do_finalize_sections(Layout*);
 100
 101   // Return the value to use for a dynamic which requires special
 102   // treatment.
 103   uint64_t
 104   do_dynsym_value(const Symbol*) const;
 105
 106   // Relocate a section.
 107   void
 108   relocate_section(const Relocate_info<32, false>*,
 109                    unsigned int sh_type,
 110                    const unsigned char* prelocs,
 111                    size_t reloc_count,
 112                    Output_section* output_section,
 113                    bool needs_special_offset_handling,
 114                    unsigned char* view,
 115                    elfcpp::Elf_types<32>::Elf_Addr view_address,
 116                    section_size_type view_size);
 117
 118   // Scan the relocs during a relocatable link.
 119   void
 120   scan_relocatable_relocs(const General_options& options,
 121                           Symbol_table* symtab,
 122                           Layout* layout,
 123                           Sized_relobj<32, false>* object,
 124                           unsigned int data_shndx,
 125                           unsigned int sh_type,
 126                           const unsigned char* prelocs,
 127                           size_t reloc_count,
 128                           Output_section* output_section,
 129                           bool needs_special_offset_handling,
 130                           size_t local_symbol_count,
 131                           const unsigned char* plocal_symbols,
 132                           Relocatable_relocs*);
 133
 134   // Relocate a section during a relocatable link.
 135   void
 136   relocate_for_relocatable(const Relocate_info<32, false>*,
 137                            unsigned int sh_type,
 138                            const unsigned char* prelocs,
 139                            size_t reloc_count,
 140                            Output_section* output_section,
 141                            off_t offset_in_output_section,
 142                            const Relocatable_relocs*,
 143                            unsigned char* view,
 144                            elfcpp::Elf_types<32>::Elf_Addr view_address,
 145                            section_size_type view_size,
 146                            unsigned char* reloc_view,
 147                            section_size_type reloc_view_size);
 148
 149   // Return a string used to fill a code section with nops.
 150   std::string
 151   do_code_fill(section_size_type length) const;
 152
 153   // Return whether SYM is defined by the ABI.
 154   bool
 155   do_is_defined_by_abi(const Symbol* sym) const
 156   { return strcmp(sym->name(), "___tls_get_addr") == 0; }
 157
 158   // Return whether a symbol name implies a local label.  The UnixWare
 159   // 2.1 cc generates temporary symbols that start with .X, so we
 160   // recognize them here.  FIXME: do other SVR4 compilers also use .X?.
 161   // If so, we should move the .X recognition into
 162   // Target::do_is_local_label_name.
 163   bool
 164   do_is_local_label_name(const char* name) const
 165   {
 166     if (name[0] == '.' && name[1] == 'X')
 167       return true;
 168     return Target::do_is_local_label_name(name);
 169   }
 170
 171   // Return the size of the GOT section.
 172   section_size_type
 173   got_size()
 174   {
 175     gold_assert(this->got_ != NULL);
 176     return this->got_->data_size();
 177   }
 178
 179  private:
 180   // The class which scans relocations.
 181   struct Scan
 182   {
 183     inline void
 184     local(const General_options& options, Symbol_table* symtab,
 185           Layout* layout, Target_i386* target,
 186           Sized_relobj<32, false>* object,
 187           unsigned int data_shndx,
 188           Output_section* output_section,
 189           const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
 190           const elfcpp::Sym<32, false>& lsym);
 191
 192     inline void
 193     global(const General_options& options, Symbol_table* symtab,
 194            Layout* layout, Target_i386* target,
 195            Sized_relobj<32, false>* object,
 196            unsigned int data_shndx,
 197            Output_section* output_section,
 198            const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
 199            Symbol* gsym);
 200
 201     static void
 202     unsupported_reloc_local(Sized_relobj<32, false>*, unsigned int r_type);
 203
 204     static void
 205     unsupported_reloc_global(Sized_relobj<32, false>*, unsigned int r_type,
 206                              Symbol*);
 207   };
 208
 209   // The class which implements relocation.
 210   class Relocate
 211   {
 212    public:
 213     Relocate()
 214       : skip_call_tls_get_addr_(false),
 215         local_dynamic_type_(LOCAL_DYNAMIC_NONE), ldo_addrs_()
 216     { }
 217
 218     ~Relocate()
 219     {
 220       if (this->skip_call_tls_get_addr_)
 221         {
 222           // FIXME: This needs to specify the location somehow.
 223           gold_error(_("missing expected TLS relocation"));
 224         }
 225     }
 226
 227     // Return whether the static relocation needs to be applied.
 228     inline bool
 229     should_apply_static_reloc(const Sized_symbol<32>* gsym,
 230                               int ref_flags,
 231                               bool is_32bit,
 232                               Output_section* output_section);
 233
 234     // Do a relocation.  Return false if the caller should not issue
 235     // any warnings about this relocation.
 236     inline bool
 237     relocate(const Relocate_info<32, false>*, Target_i386*, Output_section*,
 238              size_t relnum, const elfcpp::Rel<32, false>&,
 239              unsigned int r_type, const Sized_symbol<32>*,
 240              const Symbol_value<32>*,
 241              unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
 242              section_size_type);
 243
 244    private:
 245     // Do a TLS relocation.
 246     inline void
 247     relocate_tls(const Relocate_info<32, false>*, Target_i386* target,
 248                  size_t relnum, const elfcpp::Rel<32, false>&,
 249                  unsigned int r_type, const Sized_symbol<32>*,
 250                  const Symbol_value<32>*,
 251                  unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
 252                  section_size_type);
 253
 254     // Do a TLS General-Dynamic to Initial-Exec transition.
 255     inline void
 256     tls_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
 257                  Output_segment* tls_segment,
 258                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 259                  elfcpp::Elf_types<32>::Elf_Addr value,
 260                  unsigned char* view,
 261                  section_size_type view_size);
 262
 263     // Do a TLS General-Dynamic to Local-Exec transition.
 264     inline void
 265     tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
 266                  Output_segment* tls_segment,
 267                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 268                  elfcpp::Elf_types<32>::Elf_Addr value,
 269                  unsigned char* view,
 270                  section_size_type view_size);
 271
 272     // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
 273     // transition.
 274     inline void
 275     tls_desc_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
 276                       Output_segment* tls_segment,
 277                       const elfcpp::Rel<32, false>&, unsigned int r_type,
 278                       elfcpp::Elf_types<32>::Elf_Addr value,
 279                       unsigned char* view,
 280                       section_size_type view_size);
 281
 282     // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
 283     // transition.
 284     inline void
 285     tls_desc_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
 286                       Output_segment* tls_segment,
 287                       const elfcpp::Rel<32, false>&, unsigned int r_type,
 288                       elfcpp::Elf_types<32>::Elf_Addr value,
 289                       unsigned char* view,
 290                       section_size_type view_size);
 291
 292     // Do a TLS Local-Dynamic to Local-Exec transition.
 293     inline void
 294     tls_ld_to_le(const Relocate_info<32, false>*, size_t relnum,
 295                  Output_segment* tls_segment,
 296                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 297                  elfcpp::Elf_types<32>::Elf_Addr value,
 298                  unsigned char* view,
 299                  section_size_type view_size);
 300
 301     // Do a TLS Initial-Exec to Local-Exec transition.
 302     static inline void
 303     tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum,
 304                  Output_segment* tls_segment,
 305                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 306                  elfcpp::Elf_types<32>::Elf_Addr value,
 307                  unsigned char* view,
 308                  section_size_type view_size);
 309
 310     // Fix up LDO_32 relocations we've already seen.
 311     void
 312     fix_up_ldo(const Relocate_info<32, false>*);
 313
 314     // We need to keep track of which type of local dynamic relocation
 315     // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
 316     enum Local_dynamic_type
 317     {
 318       LOCAL_DYNAMIC_NONE,
 319       LOCAL_DYNAMIC_SUN,
 320       LOCAL_DYNAMIC_GNU
 321     };
 322
 323     // This is set if we should skip the next reloc, which should be a
 324     // PLT32 reloc against ___tls_get_addr.
 325     bool skip_call_tls_get_addr_;
 326     // The type of local dynamic relocation we have seen in the section
 327     // being relocated, if any.
 328     Local_dynamic_type local_dynamic_type_;
 329     // A list of LDO_32 offsets, in case we find LDM after LDO_32.
 330     std::vector<unsigned char*> ldo_addrs_;
 331   };
 332
 333   // A class which returns the size required for a relocation type,
 334   // used while scanning relocs during a relocatable link.
 335   class Relocatable_size_for_reloc
 336   {
 337    public:
 338     unsigned int
 339     get_size_for_reloc(unsigned int, Relobj*);
 340   };
 341
 342   // Adjust TLS relocation type based on the options and whether this
 343   // is a local symbol.
 344   static tls::Tls_optimization
 345   optimize_tls_reloc(bool is_final, int r_type);
 346
 347   // Get the GOT section, creating it if necessary.
 348   Output_data_got<32, false>*
 349   got_section(Symbol_table*, Layout*);
 350
 351   // Get the GOT PLT section.
 352   Output_data_space*
 353   got_plt_section() const
 354   {
 355     gold_assert(this->got_plt_ != NULL);
 356     return this->got_plt_;
 357   }
 358
 359   // Create a PLT entry for a global symbol.
 360   void
 361   make_plt_entry(Symbol_table*, Layout*, Symbol*);
 362
 363   // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
 364   void
 365   define_tls_base_symbol(Symbol_table*, Layout*);
 366
 367   // Create a GOT entry for the TLS module index.
 368   unsigned int
 369   got_mod_index_entry(Symbol_table* symtab, Layout* layout,
 370                       Sized_relobj<32, false>* object);
 371
 372   // Get the PLT section.
 373   const Output_data_plt_i386*
 374   plt_section() const
 375   {
 376     gold_assert(this->plt_ != NULL);
 377     return this->plt_;
 378   }
 379
 380   // Get the dynamic reloc section, creating it if necessary.
 381   Reloc_section*
 382   rel_dyn_section(Layout*);
 383
 384   // Add a potential copy relocation.
 385   void
 386   copy_reloc(Symbol_table* symtab, Layout* layout,
 387              Sized_relobj<32, false>* object,
 388              unsigned int shndx, Output_section* output_section,
 389              Symbol* sym, const elfcpp::Rel<32, false>& reloc)
 390   {
 391     this->copy_relocs_.copy_reloc(symtab, layout,
 392                                   symtab->get_sized_symbol<32>(sym),
 393                                   object, shndx, output_section, reloc,
 394                                   this->rel_dyn_section(layout));
 395   }
 396
 397   // Information about this specific target which we pass to the
 398   // general Target structure.
 399   static const Target::Target_info i386_info;
 400
 401   // The types of GOT entries needed for this platform.
 402   enum Got_type
 403   {
 404     GOT_TYPE_STANDARD = 0,      // GOT entry for a regular symbol
 405     GOT_TYPE_TLS_NOFFSET = 1,   // GOT entry for negative TLS offset
 406     GOT_TYPE_TLS_OFFSET = 2,    // GOT entry for positive TLS offset
 407     GOT_TYPE_TLS_PAIR = 3,      // GOT entry for TLS module/offset pair
 408     GOT_TYPE_TLS_DESC = 4       // GOT entry for TLS_DESC pair
 409   };
 410
 411   // The GOT section.
 412   Output_data_got<32, false>* got_;
 413   // The PLT section.
 414   Output_data_plt_i386* plt_;
 415   // The GOT PLT section.
 416   Output_data_space* got_plt_;
 417   // The dynamic reloc section.
 418   Reloc_section* rel_dyn_;
 419   // Relocs saved to avoid a COPY reloc.
 420   Copy_relocs<elfcpp::SHT_REL, 32, false> copy_relocs_;
 421   // Space for variables copied with a COPY reloc.
 422   Output_data_space* dynbss_;
 423   // Offset of the GOT entry for the TLS module index.
 424   unsigned int got_mod_index_offset_;
 425   // True if the _TLS_MODULE_BASE_ symbol has been defined.
 426   bool tls_base_symbol_defined_;
 427 };
 428
 429 const Target::Target_info Target_i386::i386_info =
 430 {
 431   32,                   // size
 432   false,                // is_big_endian
 433   elfcpp::EM_386,       // machine_code
 434   false,                // has_make_symbol
 435   false,                // has_resolve
 436   true,                 // has_code_fill
 437   true,                 // is_default_stack_executable
 438   '\0',                 // wrap_char
 439   "/usr/lib/libc.so.1", // dynamic_linker
 440   0x08048000,           // default_text_segment_address
 441   0x1000,               // abi_pagesize (overridable by -z max-page-size)
 442   0x1000,               // common_pagesize (overridable by -z common-page-size)
 443   elfcpp::SHN_UNDEF,    // small_common_shndx
 444   elfcpp::SHN_UNDEF,    // large_common_shndx
 445   0,                    // small_common_section_flags
 446   0                     // large_common_section_flags
 447 };
 448
 449 // Get the GOT section, creating it if necessary.
 450
 451 Output_data_got<32, false>*
 452 Target_i386::got_section(Symbol_table* symtab, Layout* layout)
 453 {
 454   if (this->got_ == NULL)
 455     {
 456       gold_assert(symtab != NULL && layout != NULL);
 457
 458       this->got_ = new Output_data_got<32, false>();
 459
 460       Output_section* os;
 461       os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
 462                                            (elfcpp::SHF_ALLOC
 463                                             | elfcpp::SHF_WRITE),
 464                                            this->got_);
 465       os->set_is_relro();
 466
 467       // The old GNU linker creates a .got.plt section.  We just
 468       // create another set of data in the .got section.  Note that we
 469       // always create a PLT if we create a GOT, although the PLT
 470       // might be empty.
 471       this->got_plt_ = new Output_data_space(4, "** GOT PLT");
 472       os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
 473                                            (elfcpp::SHF_ALLOC
 474                                             | elfcpp::SHF_WRITE),
 475                                            this->got_plt_);
 476       os->set_is_relro();
 477
 478       // The first three entries are reserved.
 479       this->got_plt_->set_current_data_size(3 * 4);
 480
 481       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
 482       symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
 483                                     this->got_plt_,
 484                                     0, 0, elfcpp::STT_OBJECT,
 485                                     elfcpp::STB_LOCAL,
 486                                     elfcpp::STV_HIDDEN, 0,
 487                                     false, false);
 488     }
 489
 490   return this->got_;
 491 }
 492
 493 // Get the dynamic reloc section, creating it if necessary.
 494
 495 Target_i386::Reloc_section*
 496 Target_i386::rel_dyn_section(Layout* layout)
 497 {
 498   if (this->rel_dyn_ == NULL)
 499     {
 500       gold_assert(layout != NULL);
 501       this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
 502       layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
 503                                       elfcpp::SHF_ALLOC, this->rel_dyn_);
 504     }
 505   return this->rel_dyn_;
 506 }
 507
 508 // A class to handle the PLT data.
 509
 510 class Output_data_plt_i386 : public Output_section_data
 511 {
 512  public:
 513   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
 514
 515   Output_data_plt_i386(Layout*, Output_data_space*);
 516
 517   // Add an entry to the PLT.
 518   void
 519   add_entry(Symbol* gsym);
 520
 521   // Return the .rel.plt section data.
 522   const Reloc_section*
 523   rel_plt() const
 524   { return this->rel_; }
 525
 526  protected:
 527   void
 528   do_adjust_output_section(Output_section* os);
 529
 530   // Write to a map file.
 531   void
 532   do_print_to_mapfile(Mapfile* mapfile) const
 533   { mapfile->print_output_data(this, _("** PLT")); }
 534
 535  private:
 536   // The size of an entry in the PLT.
 537   static const int plt_entry_size = 16;
 538
 539   // The first entry in the PLT for an executable.
 540   static unsigned char exec_first_plt_entry[plt_entry_size];
 541
 542   // The first entry in the PLT for a shared object.
 543   static unsigned char dyn_first_plt_entry[plt_entry_size];
 544
 545   // Other entries in the PLT for an executable.
 546   static unsigned char exec_plt_entry[plt_entry_size];
 547
 548   // Other entries in the PLT for a shared object.
 549   static unsigned char dyn_plt_entry[plt_entry_size];
 550
 551   // Set the final size.
 552   void
 553   set_final_data_size()
 554   { this->set_data_size((this->count_ + 1) * plt_entry_size); }
 555
 556   // Write out the PLT data.
 557   void
 558   do_write(Output_file*);
 559
 560   // The reloc section.
 561   Reloc_section* rel_;
 562   // The .got.plt section.
 563   Output_data_space* got_plt_;
 564   // The number of PLT entries.
 565   unsigned int count_;
 566 };
 567
 568 // Create the PLT section.  The ordinary .got section is an argument,
 569 // since we need to refer to the start.  We also create our own .got
 570 // section just for PLT entries.
 571
 572 Output_data_plt_i386::Output_data_plt_i386(Layout* layout,
 573                                            Output_data_space* got_plt)
 574   : Output_section_data(4), got_plt_(got_plt), count_(0)
 575 {
 576   this->rel_ = new Reloc_section(false);
 577   layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
 578                                   elfcpp::SHF_ALLOC, this->rel_);
 579 }
 580
 581 void
 582 Output_data_plt_i386::do_adjust_output_section(Output_section* os)
 583 {
 584   // UnixWare sets the entsize of .plt to 4, and so does the old GNU
 585   // linker, and so do we.
 586   os->set_entsize(4);
 587 }
 588
 589 // Add an entry to the PLT.
 590
 591 void
 592 Output_data_plt_i386::add_entry(Symbol* gsym)
 593 {
 594   gold_assert(!gsym->has_plt_offset());
 595
 596   // Note that when setting the PLT offset we skip the initial
 597   // reserved PLT entry.
 598   gsym->set_plt_offset((this->count_ + 1) * plt_entry_size);
 599
 600   ++this->count_;
 601
 602   section_offset_type got_offset = this->got_plt_->current_data_size();
 603
 604   // Every PLT entry needs a GOT entry which points back to the PLT
 605   // entry (this will be changed by the dynamic linker, normally
 606   // lazily when the function is called).
 607   this->got_plt_->set_current_data_size(got_offset + 4);
 608
 609   // Every PLT entry needs a reloc.
 610   gsym->set_needs_dynsym_entry();
 611   this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_,
 612                          got_offset);
 613
 614   // Note that we don't need to save the symbol.  The contents of the
 615   // PLT are independent of which symbols are used.  The symbols only
 616   // appear in the relocations.
 617 }
 618
 619 // The first entry in the PLT for an executable.
 620
 621 unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] =
 622 {
 623   0xff, 0x35,   // pushl contents of memory address
 624   0, 0, 0, 0,   // replaced with address of .got + 4
 625   0xff, 0x25,   // jmp indirect
 626   0, 0, 0, 0,   // replaced with address of .got + 8
 627   0, 0, 0, 0    // unused
 628 };
 629
 630 // The first entry in the PLT for a shared object.
 631
 632 unsigned char Output_data_plt_i386::dyn_first_plt_entry[plt_entry_size] =
 633 {
 634   0xff, 0xb3, 4, 0, 0, 0,       // pushl 4(%ebx)
 635   0xff, 0xa3, 8, 0, 0, 0,       // jmp *8(%ebx)
 636   0, 0, 0, 0                    // unused
 637 };
 638
 639 // Subsequent entries in the PLT for an executable.
 640
 641 unsigned char Output_data_plt_i386::exec_plt_entry[plt_entry_size] =
 642 {
 643   0xff, 0x25,   // jmp indirect
 644   0, 0, 0, 0,   // replaced with address of symbol in .got
 645   0x68,         // pushl immediate
 646   0, 0, 0, 0,   // replaced with offset into relocation table
 647   0xe9,         // jmp relative
 648   0, 0, 0, 0    // replaced with offset to start of .plt
 649 };
 650
 651 // Subsequent entries in the PLT for a shared object.
 652
 653 unsigned char Output_data_plt_i386::dyn_plt_entry[plt_entry_size] =
 654 {
 655   0xff, 0xa3,   // jmp *offset(%ebx)
 656   0, 0, 0, 0,   // replaced with offset of symbol in .got
 657   0x68,         // pushl immediate
 658   0, 0, 0, 0,   // replaced with offset into relocation table
 659   0xe9,         // jmp relative
 660   0, 0, 0, 0    // replaced with offset to start of .plt
 661 };
 662
 663 // Write out the PLT.  This uses the hand-coded instructions above,
 664 // and adjusts them as needed.  This is all specified by the i386 ELF
 665 // Processor Supplement.
 666
 667 void
 668 Output_data_plt_i386::do_write(Output_file* of)
 669 {
 670   const off_t offset = this->offset();
 671   const section_size_type oview_size =
 672     convert_to_section_size_type(this->data_size());
 673   unsigned char* const oview = of->get_output_view(offset, oview_size);
 674
 675   const off_t got_file_offset = this->got_plt_->offset();
 676   const section_size_type got_size =
 677     convert_to_section_size_type(this->got_plt_->data_size());
 678   unsigned char* const got_view = of->get_output_view(got_file_offset,
 679                                                       got_size);
 680
 681   unsigned char* pov = oview;
 682
 683   elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address();
 684   elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address();
 685
 686   if (parameters->options().shared())
 687     memcpy(pov, dyn_first_plt_entry, plt_entry_size);
 688   else
 689     {
 690       memcpy(pov, exec_first_plt_entry, plt_entry_size);
 691       elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
 692       elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
 693     }
 694   pov += plt_entry_size;
 695
 696   unsigned char* got_pov = got_view;
 697
 698   memset(got_pov, 0, 12);
 699   got_pov += 12;
 700
 701   const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
 702
 703   unsigned int plt_offset = plt_entry_size;
 704   unsigned int plt_rel_offset = 0;
 705   unsigned int got_offset = 12;
 706   const unsigned int count = this->count_;
 707   for (unsigned int i = 0;
 708        i < count;
 709        ++i,
 710          pov += plt_entry_size,
 711          got_pov += 4,
 712          plt_offset += plt_entry_size,
 713          plt_rel_offset += rel_size,
 714          got_offset += 4)
 715     {
 716       // Set and adjust the PLT entry itself.
 717
 718       if (parameters->options().shared())
 719         {
 720           memcpy(pov, dyn_plt_entry, plt_entry_size);
 721           elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
 722         }
 723       else
 724         {
 725           memcpy(pov, exec_plt_entry, plt_entry_size);
 726           elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
 727                                                       (got_address
 728                                                        + got_offset));
 729         }
 730
 731       elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
 732       elfcpp::Swap<32, false>::writeval(pov + 12,
 733                                         - (plt_offset + plt_entry_size));
 734
 735       // Set the entry in the GOT.
 736       elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6);
 737     }
 738
 739   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
 740   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
 741
 742   of->write_output_view(offset, oview_size, oview);
 743   of->write_output_view(got_file_offset, got_size, got_view);
 744 }
 745
 746 // Create a PLT entry for a global symbol.
 747
 748 void
 749 Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym)
 750 {
 751   if (gsym->has_plt_offset())
 752     return;
 753
 754   if (this->plt_ == NULL)
 755     {
 756       // Create the GOT sections first.
 757       this->got_section(symtab, layout);
 758
 759       this->plt_ = new Output_data_plt_i386(layout, this->got_plt_);
 760       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
 761                                       (elfcpp::SHF_ALLOC
 762                                        | elfcpp::SHF_EXECINSTR),
 763                                       this->plt_);
 764     }
 765
 766   this->plt_->add_entry(gsym);
 767 }
 768
 769 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
 770
 771 void
 772 Target_i386::define_tls_base_symbol(Symbol_table* symtab, Layout* layout)
 773 {
 774   if (this->tls_base_symbol_defined_)
 775     return;
 776
 777   Output_segment* tls_segment = layout->tls_segment();
 778   if (tls_segment != NULL)
 779     {
 780       bool is_exec = parameters->options().output_is_executable();
 781       symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
 782                                        tls_segment, 0, 0,
 783                                        elfcpp::STT_TLS,
 784                                        elfcpp::STB_LOCAL,
 785                                        elfcpp::STV_HIDDEN, 0,
 786                                        (is_exec
 787                                         ? Symbol::SEGMENT_END
 788                                         : Symbol::SEGMENT_START),
 789                                        true);
 790     }
 791   this->tls_base_symbol_defined_ = true;
 792 }
 793
 794 // Create a GOT entry for the TLS module index.
 795
 796 unsigned int
 797 Target_i386::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
 798                                  Sized_relobj<32, false>* object)
 799 {
 800   if (this->got_mod_index_offset_ == -1U)
 801     {
 802       gold_assert(symtab != NULL && layout != NULL && object != NULL);
 803       Reloc_section* rel_dyn = this->rel_dyn_section(layout);
 804       Output_data_got<32, false>* got = this->got_section(symtab, layout);
 805       unsigned int got_offset = got->add_constant(0);
 806       rel_dyn->add_local(object, 0, elfcpp::R_386_TLS_DTPMOD32, got,
 807                          got_offset);
 808       got->add_constant(0);
 809       this->got_mod_index_offset_ = got_offset;
 810     }
 811   return this->got_mod_index_offset_;
 812 }
 813
 814 // Optimize the TLS relocation type based on what we know about the
 815 // symbol.  IS_FINAL is true if the final address of this symbol is
 816 // known at link time.
 817
 818 tls::Tls_optimization
 819 Target_i386::optimize_tls_reloc(bool is_final, int r_type)
 820 {
 821   // If we are generating a shared library, then we can't do anything
 822   // in the linker.
 823   if (parameters->options().shared())
 824     return tls::TLSOPT_NONE;
 825
 826   switch (r_type)
 827     {
 828     case elfcpp::R_386_TLS_GD:
 829     case elfcpp::R_386_TLS_GOTDESC:
 830     case elfcpp::R_386_TLS_DESC_CALL:
 831       // These are General-Dynamic which permits fully general TLS
 832       // access.  Since we know that we are generating an executable,
 833       // we can convert this to Initial-Exec.  If we also know that
 834       // this is a local symbol, we can further switch to Local-Exec.
 835       if (is_final)
 836         return tls::TLSOPT_TO_LE;
 837       return tls::TLSOPT_TO_IE;
 838
 839     case elfcpp::R_386_TLS_LDM:
 840       // This is Local-Dynamic, which refers to a local symbol in the
 841       // dynamic TLS block.  Since we know that we generating an
 842       // executable, we can switch to Local-Exec.
 843       return tls::TLSOPT_TO_LE;
 844
 845     case elfcpp::R_386_TLS_LDO_32:
 846       // Another type of Local-Dynamic relocation.
 847       return tls::TLSOPT_TO_LE;
 848
 849     case elfcpp::R_386_TLS_IE:
 850     case elfcpp::R_386_TLS_GOTIE:
 851     case elfcpp::R_386_TLS_IE_32:
 852       // These are Initial-Exec relocs which get the thread offset
 853       // from the GOT.  If we know that we are linking against the
 854       // local symbol, we can switch to Local-Exec, which links the
 855       // thread offset into the instruction.
 856       if (is_final)
 857         return tls::TLSOPT_TO_LE;
 858       return tls::TLSOPT_NONE;
 859
 860     case elfcpp::R_386_TLS_LE:
 861     case elfcpp::R_386_TLS_LE_32:
 862       // When we already have Local-Exec, there is nothing further we
 863       // can do.
 864       return tls::TLSOPT_NONE;
 865
 866     default:
 867       gold_unreachable();
 868     }
 869 }
 870
 871 // Report an unsupported relocation against a local symbol.
 872
 873 void
 874 Target_i386::Scan::unsupported_reloc_local(Sized_relobj<32, false>* object,
 875                                            unsigned int r_type)
 876 {
 877   gold_error(_("%s: unsupported reloc %u against local symbol"),
 878              object->name().c_str(), r_type);
 879 }
 880
 881 // Scan a relocation for a local symbol.
 882
 883 inline void
 884 Target_i386::Scan::local(const General_options&,
 885                          Symbol_table* symtab,
 886                          Layout* layout,
 887                          Target_i386* target,
 888                          Sized_relobj<32, false>* object,
 889                          unsigned int data_shndx,
 890                          Output_section* output_section,
 891                          const elfcpp::Rel<32, false>& reloc,
 892                          unsigned int r_type,
 893                          const elfcpp::Sym<32, false>& lsym)
 894 {
 895   switch (r_type)
 896     {
 897     case elfcpp::R_386_NONE:
 898     case elfcpp::R_386_GNU_VTINHERIT:
 899     case elfcpp::R_386_GNU_VTENTRY:
 900       break;
 901
 902     case elfcpp::R_386_32:
 903       // If building a shared library (or a position-independent
 904       // executable), we need to create a dynamic relocation for
 905       // this location. The relocation applied at link time will
 906       // apply the link-time value, so we flag the location with
 907       // an R_386_RELATIVE relocation so the dynamic loader can
 908       // relocate it easily.
 909       if (parameters->options().output_is_position_independent())
 910         {
 911           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
 912           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
 913           rel_dyn->add_local_relative(object, r_sym, elfcpp::R_386_RELATIVE,
 914                                       output_section, data_shndx,
 915                                       reloc.get_r_offset());
 916         }
 917       break;
 918
 919     case elfcpp::R_386_16:
 920     case elfcpp::R_386_8:
 921       // If building a shared library (or a position-independent
 922       // executable), we need to create a dynamic relocation for
 923       // this location. Because the addend needs to remain in the
 924       // data section, we need to be careful not to apply this
 925       // relocation statically.
 926       if (parameters->options().output_is_position_independent())
 927         {
 928           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
 929           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
 930           if (lsym.get_st_type() != elfcpp::STT_SECTION)
 931             rel_dyn->add_local(object, r_sym, r_type, output_section,
 932                                data_shndx, reloc.get_r_offset());
 933           else
 934             {
 935               gold_assert(lsym.get_st_value() == 0);
 936               unsigned int shndx = lsym.get_st_shndx();
 937               bool is_ordinary;
 938               shndx = object->adjust_sym_shndx(r_sym, shndx,
 939                                                &is_ordinary);
 940               if (!is_ordinary)
 941                 object->error(_("section symbol %u has bad shndx %u"),
 942                               r_sym, shndx);
 943               else
 944                 rel_dyn->add_local_section(object, shndx,
 945                                            r_type, output_section,
 946                                            data_shndx, reloc.get_r_offset());
 947             }
 948         }
 949       break;
 950
 951     case elfcpp::R_386_PC32:
 952     case elfcpp::R_386_PC16:
 953     case elfcpp::R_386_PC8:
 954       break;
 955
 956     case elfcpp::R_386_PLT32:
 957       // Since we know this is a local symbol, we can handle this as a
 958       // PC32 reloc.
 959       break;
 960
 961     case elfcpp::R_386_GOTOFF:
 962     case elfcpp::R_386_GOTPC:
 963       // We need a GOT section.
 964       target->got_section(symtab, layout);
 965       break;
 966
 967     case elfcpp::R_386_GOT32:
 968       {
 969         // The symbol requires a GOT entry.
 970         Output_data_got<32, false>* got = target->got_section(symtab, layout);
 971         unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
 972         if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
 973           {
 974             // If we are generating a shared object, we need to add a
 975             // dynamic RELATIVE relocation for this symbol's GOT entry.
 976             if (parameters->options().output_is_position_independent())
 977               {
 978                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
 979                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
 980                 rel_dyn->add_local_relative(
 981                     object, r_sym, elfcpp::R_386_RELATIVE, got,
 982                     object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
 983               }
 984           }
 985       }
 986       break;
 987
 988       // These are relocations which should only be seen by the
 989       // dynamic linker, and should never be seen here.
 990     case elfcpp::R_386_COPY:
 991     case elfcpp::R_386_GLOB_DAT:
 992     case elfcpp::R_386_JUMP_SLOT:
 993     case elfcpp::R_386_RELATIVE:
 994     case elfcpp::R_386_TLS_TPOFF:
 995     case elfcpp::R_386_TLS_DTPMOD32:
 996     case elfcpp::R_386_TLS_DTPOFF32:
 997     case elfcpp::R_386_TLS_TPOFF32:
 998     case elfcpp::R_386_TLS_DESC:
 999       gold_error(_("%s: unexpected reloc %u in object file"),
1000                  object->name().c_str(), r_type);
1001       break;
1002
1003       // These are initial TLS relocs, which are expected when
1004       // linking.
1005     case elfcpp::R_386_TLS_GD:            // Global-dynamic
1006     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
1007     case elfcpp::R_386_TLS_DESC_CALL:
1008     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
1009     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
1010     case elfcpp::R_386_TLS_IE:            // Initial-exec
1011     case elfcpp::R_386_TLS_IE_32:
1012     case elfcpp::R_386_TLS_GOTIE:
1013     case elfcpp::R_386_TLS_LE:            // Local-exec
1014     case elfcpp::R_386_TLS_LE_32:
1015       {
1016         bool output_is_shared = parameters->options().shared();
1017         const tls::Tls_optimization optimized_type
1018             = Target_i386::optimize_tls_reloc(!output_is_shared, r_type);
1019         switch (r_type)
1020           {
1021           case elfcpp::R_386_TLS_GD:          // Global-dynamic
1022             if (optimized_type == tls::TLSOPT_NONE)
1023               {
1024                 // Create a pair of GOT entries for the module index and
1025                 // dtv-relative offset.
1026                 Output_data_got<32, false>* got
1027                     = target->got_section(symtab, layout);
1028                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1029                 unsigned int shndx = lsym.get_st_shndx();
1030                 bool is_ordinary;
1031                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1032                 if (!is_ordinary)
1033                   object->error(_("local symbol %u has bad shndx %u"),
1034                               r_sym, shndx);
1035                 else
1036                   got->add_local_pair_with_rel(object, r_sym, shndx,
1037                                                GOT_TYPE_TLS_PAIR,
1038                                                target->rel_dyn_section(layout),
1039                                                elfcpp::R_386_TLS_DTPMOD32, 0);
1040               }
1041             else if (optimized_type != tls::TLSOPT_TO_LE)
1042               unsupported_reloc_local(object, r_type);
1043             break;
1044
1045           case elfcpp::R_386_TLS_GOTDESC:     // Global-dynamic (from ~oliva)
1046             target->define_tls_base_symbol(symtab, layout);
1047             if (optimized_type == tls::TLSOPT_NONE)
1048               {
1049                 // Create a double GOT entry with an R_386_TLS_DESC reloc.
1050                 Output_data_got<32, false>* got
1051                     = target->got_section(symtab, layout);
1052                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1053                 unsigned int shndx = lsym.get_st_shndx();
1054                 bool is_ordinary;
1055                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1056                 if (!is_ordinary)
1057                   object->error(_("local symbol %u has bad shndx %u"),
1058                               r_sym, shndx);
1059                 else
1060                   got->add_local_pair_with_rel(object, r_sym, shndx,
1061                                                GOT_TYPE_TLS_DESC,
1062                                                target->rel_dyn_section(layout),
1063                                                elfcpp::R_386_TLS_DESC, 0);
1064               }
1065             else if (optimized_type != tls::TLSOPT_TO_LE)
1066               unsupported_reloc_local(object, r_type);
1067             break;
1068
1069           case elfcpp::R_386_TLS_DESC_CALL:
1070             break;
1071
1072           case elfcpp::R_386_TLS_LDM:         // Local-dynamic
1073             if (optimized_type == tls::TLSOPT_NONE)
1074               {
1075                 // Create a GOT entry for the module index.
1076                 target->got_mod_index_entry(symtab, layout, object);
1077               }
1078             else if (optimized_type != tls::TLSOPT_TO_LE)
1079               unsupported_reloc_local(object, r_type);
1080             break;
1081
1082           case elfcpp::R_386_TLS_LDO_32:      // Alternate local-dynamic
1083             break;
1084
1085           case elfcpp::R_386_TLS_IE:          // Initial-exec
1086           case elfcpp::R_386_TLS_IE_32:
1087           case elfcpp::R_386_TLS_GOTIE:
1088             layout->set_has_static_tls();
1089             if (optimized_type == tls::TLSOPT_NONE)
1090               {
1091                 // For the R_386_TLS_IE relocation, we need to create a
1092                 // dynamic relocation when building a shared library.
1093                 if (r_type == elfcpp::R_386_TLS_IE
1094                     && parameters->options().shared())
1095                   {
1096                     Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1097                     unsigned int r_sym
1098                         = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1099                     rel_dyn->add_local_relative(object, r_sym,
1100                                                 elfcpp::R_386_RELATIVE,
1101                                                 output_section, data_shndx,
1102                                                 reloc.get_r_offset());
1103                   }
1104                 // Create a GOT entry for the tp-relative offset.
1105                 Output_data_got<32, false>* got
1106                     = target->got_section(symtab, layout);
1107                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1108                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
1109                                            ? elfcpp::R_386_TLS_TPOFF32
1110                                            : elfcpp::R_386_TLS_TPOFF);
1111                 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
1112                                          ? GOT_TYPE_TLS_OFFSET
1113                                          : GOT_TYPE_TLS_NOFFSET);
1114                 got->add_local_with_rel(object, r_sym, got_type,
1115                                         target->rel_dyn_section(layout),
1116                                         dyn_r_type);
1117               }
1118             else if (optimized_type != tls::TLSOPT_TO_LE)
1119               unsupported_reloc_local(object, r_type);
1120             break;
1121
1122           case elfcpp::R_386_TLS_LE:          // Local-exec
1123           case elfcpp::R_386_TLS_LE_32:
1124             layout->set_has_static_tls();
1125             if (output_is_shared)
1126               {
1127                 // We need to create a dynamic relocation.
1128                 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
1129                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1130                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
1131                                            ? elfcpp::R_386_TLS_TPOFF32
1132                                            : elfcpp::R_386_TLS_TPOFF);
1133                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1134                 rel_dyn->add_local(object, r_sym, dyn_r_type, output_section,
1135                                    data_shndx, reloc.get_r_offset());
1136               }
1137             break;
1138
1139           default:
1140             gold_unreachable();
1141           }
1142       }
1143       break;
1144
1145     case elfcpp::R_386_32PLT:
1146     case elfcpp::R_386_TLS_GD_32:
1147     case elfcpp::R_386_TLS_GD_PUSH:
1148     case elfcpp::R_386_TLS_GD_CALL:
1149     case elfcpp::R_386_TLS_GD_POP:
1150     case elfcpp::R_386_TLS_LDM_32:
1151     case elfcpp::R_386_TLS_LDM_PUSH:
1152     case elfcpp::R_386_TLS_LDM_CALL:
1153     case elfcpp::R_386_TLS_LDM_POP:
1154     case elfcpp::R_386_USED_BY_INTEL_200:
1155     default:
1156       unsupported_reloc_local(object, r_type);
1157       break;
1158     }
1159 }
1160
1161 // Report an unsupported relocation against a global symbol.
1162
1163 void
1164 Target_i386::Scan::unsupported_reloc_global(Sized_relobj<32, false>* object,
1165                                             unsigned int r_type,
1166                                             Symbol* gsym)
1167 {
1168   gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1169              object->name().c_str(), r_type, gsym->demangled_name().c_str());
1170 }
1171
1172 // Scan a relocation for a global symbol.
1173
1174 inline void
1175 Target_i386::Scan::global(const General_options&,
1176                           Symbol_table* symtab,
1177                           Layout* layout,
1178                           Target_i386* target,
1179                           Sized_relobj<32, false>* object,
1180                           unsigned int data_shndx,
1181                           Output_section* output_section,
1182                           const elfcpp::Rel<32, false>& reloc,
1183                           unsigned int r_type,
1184                           Symbol* gsym)
1185 {
1186   switch (r_type)
1187     {
1188     case elfcpp::R_386_NONE:
1189     case elfcpp::R_386_GNU_VTINHERIT:
1190     case elfcpp::R_386_GNU_VTENTRY:
1191       break;
1192
1193     case elfcpp::R_386_32:
1194     case elfcpp::R_386_16:
1195     case elfcpp::R_386_8:
1196       {
1197         // Make a PLT entry if necessary.
1198         if (gsym->needs_plt_entry())
1199           {
1200             target->make_plt_entry(symtab, layout, gsym);
1201             // Since this is not a PC-relative relocation, we may be
1202             // taking the address of a function. In that case we need to
1203             // set the entry in the dynamic symbol table to the address of
1204             // the PLT entry.
1205             if (gsym->is_from_dynobj() && !parameters->options().shared())
1206               gsym->set_needs_dynsym_value();
1207           }
1208         // Make a dynamic relocation if necessary.
1209         if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
1210           {
1211             if (gsym->may_need_copy_reloc())
1212               {
1213                 target->copy_reloc(symtab, layout, object,
1214                                    data_shndx, output_section, gsym, reloc);
1215               }
1216             else if (r_type == elfcpp::R_386_32
1217                      && gsym->can_use_relative_reloc(false))
1218               {
1219                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1220                 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1221                                              output_section, object,
1222                                              data_shndx, reloc.get_r_offset());
1223               }
1224             else
1225               {
1226                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1227                 rel_dyn->add_global(gsym, r_type, output_section, object,
1228                                     data_shndx, reloc.get_r_offset());
1229               }
1230           }
1231       }
1232       break;
1233
1234     case elfcpp::R_386_PC32:
1235     case elfcpp::R_386_PC16:
1236     case elfcpp::R_386_PC8:
1237       {
1238         // Make a PLT entry if necessary.
1239         if (gsym->needs_plt_entry())
1240           {
1241             // These relocations are used for function calls only in
1242             // non-PIC code.  For a 32-bit relocation in a shared library,
1243             // we'll need a text relocation anyway, so we can skip the
1244             // PLT entry and let the dynamic linker bind the call directly
1245             // to the target.  For smaller relocations, we should use a
1246             // PLT entry to ensure that the call can reach.
1247             if (!parameters->options().shared()
1248                 || r_type != elfcpp::R_386_PC32)
1249               target->make_plt_entry(symtab, layout, gsym);
1250           }
1251         // Make a dynamic relocation if necessary.
1252         int flags = Symbol::NON_PIC_REF;
1253         if (gsym->type() == elfcpp::STT_FUNC)
1254           flags |= Symbol::FUNCTION_CALL;
1255         if (gsym->needs_dynamic_reloc(flags))
1256           {
1257             if (gsym->may_need_copy_reloc())
1258               {
1259                 target->copy_reloc(symtab, layout, object,
1260                                    data_shndx, output_section, gsym, reloc);
1261               }
1262             else
1263               {
1264                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1265                 rel_dyn->add_global(gsym, r_type, output_section, object,
1266                                     data_shndx, reloc.get_r_offset());
1267               }
1268           }
1269       }
1270       break;
1271
1272     case elfcpp::R_386_GOT32:
1273       {
1274         // The symbol requires a GOT entry.
1275         Output_data_got<32, false>* got = target->got_section(symtab, layout);
1276         if (gsym->final_value_is_known())
1277           got->add_global(gsym, GOT_TYPE_STANDARD);
1278         else
1279           {
1280             // If this symbol is not fully resolved, we need to add a
1281             // GOT entry with a dynamic relocation.
1282             Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1283             if (gsym->is_from_dynobj()
1284                 || gsym->is_undefined()
1285                 || gsym->is_preemptible())
1286               got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
1287                                        rel_dyn, elfcpp::R_386_GLOB_DAT);
1288             else
1289               {
1290                 if (got->add_global(gsym, GOT_TYPE_STANDARD))
1291                   rel_dyn->add_global_relative(
1292                       gsym, elfcpp::R_386_RELATIVE, got,
1293                       gsym->got_offset(GOT_TYPE_STANDARD));
1294               }
1295           }
1296       }
1297       break;
1298
1299     case elfcpp::R_386_PLT32:
1300       // If the symbol is fully resolved, this is just a PC32 reloc.
1301       // Otherwise we need a PLT entry.
1302       if (gsym->final_value_is_known())
1303         break;
1304       // If building a shared library, we can also skip the PLT entry
1305       // if the symbol is defined in the output file and is protected
1306       // or hidden.
1307       if (gsym->is_defined()
1308           && !gsym->is_from_dynobj()
1309           && !gsym->is_preemptible())
1310         break;
1311       target->make_plt_entry(symtab, layout, gsym);
1312       break;
1313
1314     case elfcpp::R_386_GOTOFF:
1315     case elfcpp::R_386_GOTPC:
1316       // We need a GOT section.
1317       target->got_section(symtab, layout);
1318       break;
1319
1320       // These are relocations which should only be seen by the
1321       // dynamic linker, and should never be seen here.
1322     case elfcpp::R_386_COPY:
1323     case elfcpp::R_386_GLOB_DAT:
1324     case elfcpp::R_386_JUMP_SLOT:
1325     case elfcpp::R_386_RELATIVE:
1326     case elfcpp::R_386_TLS_TPOFF:
1327     case elfcpp::R_386_TLS_DTPMOD32:
1328     case elfcpp::R_386_TLS_DTPOFF32:
1329     case elfcpp::R_386_TLS_TPOFF32:
1330     case elfcpp::R_386_TLS_DESC:
1331       gold_error(_("%s: unexpected reloc %u in object file"),
1332                  object->name().c_str(), r_type);
1333       break;
1334
1335       // These are initial tls relocs, which are expected when
1336       // linking.
1337     case elfcpp::R_386_TLS_GD:            // Global-dynamic
1338     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
1339     case elfcpp::R_386_TLS_DESC_CALL:
1340     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
1341     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
1342     case elfcpp::R_386_TLS_IE:            // Initial-exec
1343     case elfcpp::R_386_TLS_IE_32:
1344     case elfcpp::R_386_TLS_GOTIE:
1345     case elfcpp::R_386_TLS_LE:            // Local-exec
1346     case elfcpp::R_386_TLS_LE_32:
1347       {
1348         const bool is_final = gsym->final_value_is_known();
1349         const tls::Tls_optimization optimized_type
1350             = Target_i386::optimize_tls_reloc(is_final, r_type);
1351         switch (r_type)
1352           {
1353           case elfcpp::R_386_TLS_GD:          // Global-dynamic
1354             if (optimized_type == tls::TLSOPT_NONE)
1355               {
1356                 // Create a pair of GOT entries for the module index and
1357                 // dtv-relative offset.
1358                 Output_data_got<32, false>* got
1359                     = target->got_section(symtab, layout);
1360                 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
1361                                              target->rel_dyn_section(layout),
1362                                              elfcpp::R_386_TLS_DTPMOD32,
1363                                              elfcpp::R_386_TLS_DTPOFF32);
1364               }
1365             else if (optimized_type == tls::TLSOPT_TO_IE)
1366               {
1367                 // Create a GOT entry for the tp-relative offset.
1368                 Output_data_got<32, false>* got
1369                     = target->got_section(symtab, layout);
1370                 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
1371                                          target->rel_dyn_section(layout),
1372                                          elfcpp::R_386_TLS_TPOFF);
1373               }
1374             else if (optimized_type != tls::TLSOPT_TO_LE)
1375               unsupported_reloc_global(object, r_type, gsym);
1376             break;
1377
1378           case elfcpp::R_386_TLS_GOTDESC:     // Global-dynamic (~oliva url)
1379             target->define_tls_base_symbol(symtab, layout);
1380             if (optimized_type == tls::TLSOPT_NONE)
1381               {
1382                 // Create a double GOT entry with an R_386_TLS_DESC reloc.
1383                 Output_data_got<32, false>* got
1384                     = target->got_section(symtab, layout);
1385                 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC,
1386                                              target->rel_dyn_section(layout),
1387                                              elfcpp::R_386_TLS_DESC, 0);
1388               }
1389             else if (optimized_type == tls::TLSOPT_TO_IE)
1390               {
1391                 // Create a GOT entry for the tp-relative offset.
1392                 Output_data_got<32, false>* got
1393                     = target->got_section(symtab, layout);
1394                 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
1395                                          target->rel_dyn_section(layout),
1396                                          elfcpp::R_386_TLS_TPOFF);
1397               }
1398             else if (optimized_type != tls::TLSOPT_TO_LE)
1399               unsupported_reloc_global(object, r_type, gsym);
1400             break;
1401
1402           case elfcpp::R_386_TLS_DESC_CALL:
1403             break;
1404
1405           case elfcpp::R_386_TLS_LDM:         // Local-dynamic
1406             if (optimized_type == tls::TLSOPT_NONE)
1407               {
1408                 // Create a GOT entry for the module index.
1409                 target->got_mod_index_entry(symtab, layout, object);
1410               }
1411             else if (optimized_type != tls::TLSOPT_TO_LE)
1412               unsupported_reloc_global(object, r_type, gsym);
1413             break;
1414
1415           case elfcpp::R_386_TLS_LDO_32:      // Alternate local-dynamic
1416             break;
1417
1418           case elfcpp::R_386_TLS_IE:          // Initial-exec
1419           case elfcpp::R_386_TLS_IE_32:
1420           case elfcpp::R_386_TLS_GOTIE:
1421             layout->set_has_static_tls();
1422             if (optimized_type == tls::TLSOPT_NONE)
1423               {
1424                 // For the R_386_TLS_IE relocation, we need to create a
1425                 // dynamic relocation when building a shared library.
1426                 if (r_type == elfcpp::R_386_TLS_IE
1427                     && parameters->options().shared())
1428                   {
1429                     Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1430                     rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1431                                                  output_section, object,
1432                                                  data_shndx,
1433                                                  reloc.get_r_offset());
1434                   }
1435                 // Create a GOT entry for the tp-relative offset.
1436                 Output_data_got<32, false>* got
1437                     = target->got_section(symtab, layout);
1438                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
1439                                            ? elfcpp::R_386_TLS_TPOFF32
1440                                            : elfcpp::R_386_TLS_TPOFF);
1441                 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
1442                                          ? GOT_TYPE_TLS_OFFSET
1443                                          : GOT_TYPE_TLS_NOFFSET);
1444                 got->add_global_with_rel(gsym, got_type,
1445                                          target->rel_dyn_section(layout),
1446                                          dyn_r_type);
1447               }
1448             else if (optimized_type != tls::TLSOPT_TO_LE)
1449               unsupported_reloc_global(object, r_type, gsym);
1450             break;
1451
1452           case elfcpp::R_386_TLS_LE:          // Local-exec
1453           case elfcpp::R_386_TLS_LE_32:
1454             layout->set_has_static_tls();
1455             if (parameters->options().shared())
1456               {
1457                 // We need to create a dynamic relocation.
1458                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
1459                                            ? elfcpp::R_386_TLS_TPOFF32
1460                                            : elfcpp::R_386_TLS_TPOFF);
1461                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1462                 rel_dyn->add_global(gsym, dyn_r_type, output_section, object,
1463                                     data_shndx, reloc.get_r_offset());
1464               }
1465             break;
1466
1467           default:
1468             gold_unreachable();
1469           }
1470       }
1471       break;
1472
1473     case elfcpp::R_386_32PLT:
1474     case elfcpp::R_386_TLS_GD_32:
1475     case elfcpp::R_386_TLS_GD_PUSH:
1476     case elfcpp::R_386_TLS_GD_CALL:
1477     case elfcpp::R_386_TLS_GD_POP:
1478     case elfcpp::R_386_TLS_LDM_32:
1479     case elfcpp::R_386_TLS_LDM_PUSH:
1480     case elfcpp::R_386_TLS_LDM_CALL:
1481     case elfcpp::R_386_TLS_LDM_POP:
1482     case elfcpp::R_386_USED_BY_INTEL_200:
1483     default:
1484       unsupported_reloc_global(object, r_type, gsym);
1485       break;
1486     }
1487 }
1488
1489 // Process relocations for gc.
1490
1491 void
1492 Target_i386::gc_process_relocs(const General_options& options,
1493                                Symbol_table* symtab,
1494                                Layout* layout,
1495                                Sized_relobj<32, false>* object,
1496                                unsigned int data_shndx,
1497                                unsigned int,
1498                                const unsigned char* prelocs,
1499                                size_t reloc_count,
1500                                Output_section* output_section,
1501                                bool needs_special_offset_handling,
1502                                size_t local_symbol_count,
1503                                const unsigned char* plocal_symbols)
1504 {
1505   gold::gc_process_relocs<32, false, Target_i386, elfcpp::SHT_REL,
1506                           Target_i386::Scan>(
1507     options,
1508     symtab,
1509     layout,
1510     this,
1511     object,
1512     data_shndx,
1513     prelocs,
1514     reloc_count,
1515     output_section,
1516     needs_special_offset_handling,
1517     local_symbol_count,
1518     plocal_symbols);
1519 }
1520
1521 // Scan relocations for a section.
1522
1523 void
1524 Target_i386::scan_relocs(const General_options& options,
1525                          Symbol_table* symtab,
1526                          Layout* layout,
1527                          Sized_relobj<32, false>* object,
1528                          unsigned int data_shndx,
1529                          unsigned int sh_type,
1530                          const unsigned char* prelocs,
1531                          size_t reloc_count,
1532                          Output_section* output_section,
1533                          bool needs_special_offset_handling,
1534                          size_t local_symbol_count,
1535                          const unsigned char* plocal_symbols)
1536 {
1537   if (sh_type == elfcpp::SHT_RELA)
1538     {
1539       gold_error(_("%s: unsupported RELA reloc section"),
1540                  object->name().c_str());
1541       return;
1542     }
1543
1544   gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL,
1545                     Target_i386::Scan>(
1546     options,
1547     symtab,
1548     layout,
1549     this,
1550     object,
1551     data_shndx,
1552     prelocs,
1553     reloc_count,
1554     output_section,
1555     needs_special_offset_handling,
1556     local_symbol_count,
1557     plocal_symbols);
1558 }
1559
1560 // Finalize the sections.
1561
1562 void
1563 Target_i386::do_finalize_sections(Layout* layout)
1564 {
1565   // Fill in some more dynamic tags.
1566   Output_data_dynamic* const odyn = layout->dynamic_data();
1567   if (odyn != NULL)
1568     {
1569       if (this->got_plt_ != NULL)
1570         odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_);
1571
1572       if (this->plt_ != NULL)
1573         {
1574           const Output_data* od = this->plt_->rel_plt();
1575           odyn->add_section_size(elfcpp::DT_PLTRELSZ, od);
1576           odyn->add_section_address(elfcpp::DT_JMPREL, od);
1577           odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_REL);
1578         }
1579
1580       if (this->rel_dyn_ != NULL)
1581         {
1582           const Output_data* od = this->rel_dyn_;
1583           odyn->add_section_address(elfcpp::DT_REL, od);
1584           odyn->add_section_size(elfcpp::DT_RELSZ, od);
1585           odyn->add_constant(elfcpp::DT_RELENT,
1586                              elfcpp::Elf_sizes<32>::rel_size);
1587         }
1588
1589       if (!parameters->options().shared())
1590         {
1591           // The value of the DT_DEBUG tag is filled in by the dynamic
1592           // linker at run time, and used by the debugger.
1593           odyn->add_constant(elfcpp::DT_DEBUG, 0);
1594         }
1595     }
1596
1597   // Emit any relocs we saved in an attempt to avoid generating COPY
1598   // relocs.
1599   if (this->copy_relocs_.any_saved_relocs())
1600     this->copy_relocs_.emit(this->rel_dyn_section(layout));
1601 }
1602
1603 // Return whether a direct absolute static relocation needs to be applied.
1604 // In cases where Scan::local() or Scan::global() has created
1605 // a dynamic relocation other than R_386_RELATIVE, the addend
1606 // of the relocation is carried in the data, and we must not
1607 // apply the static relocation.
1608
1609 inline bool
1610 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol<32>* gsym,
1611                                                  int ref_flags,
1612                                                  bool is_32bit,
1613                                                  Output_section* output_section)
1614 {
1615   // If the output section is not allocated, then we didn't call
1616   // scan_relocs, we didn't create a dynamic reloc, and we must apply
1617   // the reloc here.
1618   if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
1619     return true;
1620
1621   // For local symbols, we will have created a non-RELATIVE dynamic
1622   // relocation only if (a) the output is position independent,
1623   // (b) the relocation is absolute (not pc- or segment-relative), and
1624   // (c) the relocation is not 32 bits wide.
1625   if (gsym == NULL)
1626     return !(parameters->options().output_is_position_independent()
1627              && (ref_flags & Symbol::ABSOLUTE_REF)
1628              && !is_32bit);
1629
1630   // For global symbols, we use the same helper routines used in the
1631   // scan pass.  If we did not create a dynamic relocation, or if we
1632   // created a RELATIVE dynamic relocation, we should apply the static
1633   // relocation.
1634   bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
1635   bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
1636                 && gsym->can_use_relative_reloc(ref_flags
1637                                                 & Symbol::FUNCTION_CALL);
1638   return !has_dyn || is_rel;
1639 }
1640
1641 // Perform a relocation.
1642
1643 inline bool
1644 Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
1645                                 Target_i386* target,
1646                                 Output_section *output_section,
1647                                 size_t relnum,
1648                                 const elfcpp::Rel<32, false>& rel,
1649                                 unsigned int r_type,
1650                                 const Sized_symbol<32>* gsym,
1651                                 const Symbol_value<32>* psymval,
1652                                 unsigned char* view,
1653                                 elfcpp::Elf_types<32>::Elf_Addr address,
1654                                 section_size_type view_size)
1655 {
1656   if (this->skip_call_tls_get_addr_)
1657     {
1658       if ((r_type != elfcpp::R_386_PLT32
1659            && r_type != elfcpp::R_386_PC32)
1660           || gsym == NULL
1661           || strcmp(gsym->name(), "___tls_get_addr") != 0)
1662         gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1663                                _("missing expected TLS relocation"));
1664       else
1665         {
1666           this->skip_call_tls_get_addr_ = false;
1667           return false;
1668         }
1669     }
1670
1671   // Pick the value to use for symbols defined in shared objects.
1672   Symbol_value<32> symval;
1673   if (gsym != NULL
1674       && gsym->use_plt_offset(r_type == elfcpp::R_386_PC8
1675                               || r_type == elfcpp::R_386_PC16
1676                               || r_type == elfcpp::R_386_PC32))
1677     {
1678       symval.set_output_value(target->plt_section()->address()
1679                               + gsym->plt_offset());
1680       psymval = &symval;
1681     }
1682
1683   const Sized_relobj<32, false>* object = relinfo->object;
1684
1685   // Get the GOT offset if needed.
1686   // The GOT pointer points to the end of the GOT section.
1687   // We need to subtract the size of the GOT section to get
1688   // the actual offset to use in the relocation.
1689   bool have_got_offset = false;
1690   unsigned int got_offset = 0;
1691   switch (r_type)
1692     {
1693     case elfcpp::R_386_GOT32:
1694       if (gsym != NULL)
1695         {
1696           gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
1697           got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
1698                         - target->got_size());
1699         }
1700       else
1701         {
1702           unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
1703           gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
1704           got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
1705                         - target->got_size());
1706         }
1707       have_got_offset = true;
1708       break;
1709
1710     default:
1711       break;
1712     }
1713
1714   switch (r_type)
1715     {
1716     case elfcpp::R_386_NONE:
1717     case elfcpp::R_386_GNU_VTINHERIT:
1718     case elfcpp::R_386_GNU_VTENTRY:
1719       break;
1720
1721     case elfcpp::R_386_32:
1722       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
1723                                     output_section))
1724         Relocate_functions<32, false>::rel32(view, object, psymval);
1725       break;
1726
1727     case elfcpp::R_386_PC32:
1728       {
1729         int ref_flags = Symbol::NON_PIC_REF;
1730         if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC)
1731           ref_flags |= Symbol::FUNCTION_CALL;
1732         if (should_apply_static_reloc(gsym, ref_flags, true, output_section))
1733           Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1734       }
1735       break;
1736
1737     case elfcpp::R_386_16:
1738       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
1739                                     output_section))
1740         Relocate_functions<32, false>::rel16(view, object, psymval);
1741       break;
1742
1743     case elfcpp::R_386_PC16:
1744       {
1745         int ref_flags = Symbol::NON_PIC_REF;
1746         if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC)
1747           ref_flags |= Symbol::FUNCTION_CALL;
1748         if (should_apply_static_reloc(gsym, ref_flags, false, output_section))
1749           Relocate_functions<32, false>::pcrel16(view, object, psymval, address);
1750       }
1751       break;
1752
1753     case elfcpp::R_386_8:
1754       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
1755                                     output_section))
1756         Relocate_functions<32, false>::rel8(view, object, psymval);
1757       break;
1758
1759     case elfcpp::R_386_PC8:
1760       {
1761         int ref_flags = Symbol::NON_PIC_REF;
1762         if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC)
1763           ref_flags |= Symbol::FUNCTION_CALL;
1764         if (should_apply_static_reloc(gsym, ref_flags, false,
1765                                       output_section))
1766           Relocate_functions<32, false>::pcrel8(view, object, psymval, address);
1767       }
1768       break;
1769
1770     case elfcpp::R_386_PLT32:
1771       gold_assert(gsym == NULL
1772                   || gsym->has_plt_offset()
1773                   || gsym->final_value_is_known()
1774                   || (gsym->is_defined()
1775                       && !gsym->is_from_dynobj()
1776                       && !gsym->is_preemptible()));
1777       Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1778       break;
1779
1780     case elfcpp::R_386_GOT32:
1781       gold_assert(have_got_offset);
1782       Relocate_functions<32, false>::rel32(view, got_offset);
1783       break;
1784
1785     case elfcpp::R_386_GOTOFF:
1786       {
1787         elfcpp::Elf_types<32>::Elf_Addr value;
1788         value = (psymval->value(object, 0)
1789                  - target->got_plt_section()->address());
1790         Relocate_functions<32, false>::rel32(view, value);
1791       }
1792       break;
1793
1794     case elfcpp::R_386_GOTPC:
1795       {
1796         elfcpp::Elf_types<32>::Elf_Addr value;
1797         value = target->got_plt_section()->address();
1798         Relocate_functions<32, false>::pcrel32(view, value, address);
1799       }
1800       break;
1801
1802     case elfcpp::R_386_COPY:
1803     case elfcpp::R_386_GLOB_DAT:
1804     case elfcpp::R_386_JUMP_SLOT:
1805     case elfcpp::R_386_RELATIVE:
1806       // These are outstanding tls relocs, which are unexpected when
1807       // linking.
1808     case elfcpp::R_386_TLS_TPOFF:
1809     case elfcpp::R_386_TLS_DTPMOD32:
1810     case elfcpp::R_386_TLS_DTPOFF32:
1811     case elfcpp::R_386_TLS_TPOFF32:
1812     case elfcpp::R_386_TLS_DESC:
1813       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1814                              _("unexpected reloc %u in object file"),
1815                              r_type);
1816       break;
1817
1818       // These are initial tls relocs, which are expected when
1819       // linking.
1820     case elfcpp::R_386_TLS_GD:             // Global-dynamic
1821     case elfcpp::R_386_TLS_GOTDESC:        // Global-dynamic (from ~oliva url)
1822     case elfcpp::R_386_TLS_DESC_CALL:
1823     case elfcpp::R_386_TLS_LDM:            // Local-dynamic
1824     case elfcpp::R_386_TLS_LDO_32:         // Alternate local-dynamic
1825     case elfcpp::R_386_TLS_IE:             // Initial-exec
1826     case elfcpp::R_386_TLS_IE_32:
1827     case elfcpp::R_386_TLS_GOTIE:
1828     case elfcpp::R_386_TLS_LE:             // Local-exec
1829     case elfcpp::R_386_TLS_LE_32:
1830       this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
1831                          view, address, view_size);
1832       break;
1833
1834     case elfcpp::R_386_32PLT:
1835     case elfcpp::R_386_TLS_GD_32:
1836     case elfcpp::R_386_TLS_GD_PUSH:
1837     case elfcpp::R_386_TLS_GD_CALL:
1838     case elfcpp::R_386_TLS_GD_POP:
1839     case elfcpp::R_386_TLS_LDM_32:
1840     case elfcpp::R_386_TLS_LDM_PUSH:
1841     case elfcpp::R_386_TLS_LDM_CALL:
1842     case elfcpp::R_386_TLS_LDM_POP:
1843     case elfcpp::R_386_USED_BY_INTEL_200:
1844     default:
1845       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1846                              _("unsupported reloc %u"),
1847                              r_type);
1848       break;
1849     }
1850
1851   return true;
1852 }
1853
1854 // Perform a TLS relocation.
1855
1856 inline void
1857 Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo,
1858                                     Target_i386* target,
1859                                     size_t relnum,
1860                                     const elfcpp::Rel<32, false>& rel,
1861                                     unsigned int r_type,
1862                                     const Sized_symbol<32>* gsym,
1863                                     const Symbol_value<32>* psymval,
1864                                     unsigned char* view,
1865                                     elfcpp::Elf_types<32>::Elf_Addr,
1866                                     section_size_type view_size)
1867 {
1868   Output_segment* tls_segment = relinfo->layout->tls_segment();
1869
1870   const Sized_relobj<32, false>* object = relinfo->object;
1871
1872   elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
1873
1874   const bool is_final =
1875     (gsym == NULL
1876      ? !parameters->options().output_is_position_independent()
1877      : gsym->final_value_is_known());
1878   const tls::Tls_optimization optimized_type
1879       = Target_i386::optimize_tls_reloc(is_final, r_type);
1880   switch (r_type)
1881     {
1882     case elfcpp::R_386_TLS_GD:           // Global-dynamic
1883       if (optimized_type == tls::TLSOPT_TO_LE)
1884         {
1885           gold_assert(tls_segment != NULL);
1886           this->tls_gd_to_le(relinfo, relnum, tls_segment,
1887                              rel, r_type, value, view,
1888                              view_size);
1889           break;
1890         }
1891       else
1892         {
1893           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
1894                                    ? GOT_TYPE_TLS_NOFFSET
1895                                    : GOT_TYPE_TLS_PAIR);
1896           unsigned int got_offset;
1897           if (gsym != NULL)
1898             {
1899               gold_assert(gsym->has_got_offset(got_type));
1900               got_offset = gsym->got_offset(got_type) - target->got_size();
1901             }
1902           else
1903             {
1904               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
1905               gold_assert(object->local_has_got_offset(r_sym, got_type));
1906               got_offset = (object->local_got_offset(r_sym, got_type)
1907                             - target->got_size());
1908             }
1909           if (optimized_type == tls::TLSOPT_TO_IE)
1910             {
1911               gold_assert(tls_segment != NULL);
1912               this->tls_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
1913                                  got_offset, view, view_size);
1914               break;
1915             }
1916           else if (optimized_type == tls::TLSOPT_NONE)
1917             {
1918               // Relocate the field with the offset of the pair of GOT
1919               // entries.
1920               Relocate_functions<32, false>::rel32(view, got_offset);
1921               break;
1922             }
1923         }
1924       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1925                              _("unsupported reloc %u"),
1926                              r_type);
1927       break;
1928
1929     case elfcpp::R_386_TLS_GOTDESC:      // Global-dynamic (from ~oliva url)
1930     case elfcpp::R_386_TLS_DESC_CALL:
1931       if (this->local_dynamic_type_ == LOCAL_DYNAMIC_NONE)
1932         this->fix_up_ldo(relinfo);
1933       this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
1934       if (optimized_type == tls::TLSOPT_TO_LE)
1935         {
1936           gold_assert(tls_segment != NULL);
1937           this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
1938                                   rel, r_type, value, view,
1939                                   view_size);
1940           break;
1941         }
1942       else
1943         {
1944           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
1945                                    ? GOT_TYPE_TLS_NOFFSET
1946                                    : GOT_TYPE_TLS_DESC);
1947           unsigned int got_offset;
1948           if (gsym != NULL)
1949             {
1950               gold_assert(gsym->has_got_offset(got_type));
1951               got_offset = gsym->got_offset(got_type) - target->got_size();
1952             }
1953           else
1954             {
1955               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
1956               gold_assert(object->local_has_got_offset(r_sym, got_type));
1957               got_offset = (object->local_got_offset(r_sym, got_type)
1958                             - target->got_size());
1959             }
1960           if (optimized_type == tls::TLSOPT_TO_IE)
1961             {
1962               gold_assert(tls_segment != NULL);
1963               this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
1964                                       got_offset, view, view_size);
1965               break;
1966             }
1967           else if (optimized_type == tls::TLSOPT_NONE)
1968             {
1969               if (r_type == elfcpp::R_386_TLS_GOTDESC)
1970                 {
1971                   // Relocate the field with the offset of the pair of GOT
1972                   // entries.
1973                   Relocate_functions<32, false>::rel32(view, got_offset);
1974                 }
1975               break;
1976             }
1977         }
1978       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1979                              _("unsupported reloc %u"),
1980                              r_type);
1981       break;
1982
1983     case elfcpp::R_386_TLS_LDM:          // Local-dynamic
1984       if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN)
1985         {
1986           gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1987                                  _("both SUN and GNU model "
1988                                    "TLS relocations"));
1989           break;
1990         }
1991       else if (this->local_dynamic_type_ == LOCAL_DYNAMIC_NONE)
1992         this->fix_up_ldo(relinfo);
1993       this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
1994       if (optimized_type == tls::TLSOPT_TO_LE)
1995         {
1996           gold_assert(tls_segment != NULL);
1997           this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, r_type,
1998                              value, view, view_size);
1999           break;
2000         }
2001       else if (optimized_type == tls::TLSOPT_NONE)
2002         {
2003           // Relocate the field with the offset of the GOT entry for
2004           // the module index.
2005           unsigned int got_offset;
2006           got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
2007                         - target->got_size());
2008           Relocate_functions<32, false>::rel32(view, got_offset);
2009           break;
2010         }
2011       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2012                              _("unsupported reloc %u"),
2013                              r_type);
2014       break;
2015
2016     case elfcpp::R_386_TLS_LDO_32:       // Alternate local-dynamic
2017       // This reloc can appear in debugging sections, in which case we
2018       // won't see the TLS_LDM reloc.  The local_dynamic_type field
2019       // tells us this.
2020       if (optimized_type == tls::TLSOPT_TO_LE
2021           && this->local_dynamic_type_ != LOCAL_DYNAMIC_NONE)
2022         {
2023           gold_assert(tls_segment != NULL);
2024           value -= tls_segment->memsz();
2025         }
2026       else
2027         {
2028           // We may see the LDM later.
2029           this->ldo_addrs_.push_back(view);
2030         }
2031       Relocate_functions<32, false>::rel32(view, value);
2032       break;
2033
2034     case elfcpp::R_386_TLS_IE:           // Initial-exec
2035     case elfcpp::R_386_TLS_GOTIE:
2036     case elfcpp::R_386_TLS_IE_32:
2037       if (optimized_type == tls::TLSOPT_TO_LE)
2038         {
2039           gold_assert(tls_segment != NULL);
2040           Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
2041                                               rel, r_type, value, view,
2042                                               view_size);
2043           break;
2044         }
2045       else if (optimized_type == tls::TLSOPT_NONE)
2046         {
2047           // Relocate the field with the offset of the GOT entry for
2048           // the tp-relative offset of the symbol.
2049           unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
2050                                    ? GOT_TYPE_TLS_OFFSET
2051                                    : GOT_TYPE_TLS_NOFFSET);
2052           unsigned int got_offset;
2053           if (gsym != NULL)
2054             {
2055               gold_assert(gsym->has_got_offset(got_type));
2056               got_offset = gsym->got_offset(got_type);
2057             }
2058           else
2059             {
2060               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2061               gold_assert(object->local_has_got_offset(r_sym, got_type));
2062               got_offset = object->local_got_offset(r_sym, got_type);
2063             }
2064           // For the R_386_TLS_IE relocation, we need to apply the
2065           // absolute address of the GOT entry.
2066           if (r_type == elfcpp::R_386_TLS_IE)
2067             got_offset += target->got_plt_section()->address();
2068           // All GOT offsets are relative to the end of the GOT.
2069           got_offset -= target->got_size();
2070           Relocate_functions<32, false>::rel32(view, got_offset);
2071           break;
2072         }
2073       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2074                              _("unsupported reloc %u"),
2075                              r_type);
2076       break;
2077
2078     case elfcpp::R_386_TLS_LE:           // Local-exec
2079       // If we're creating a shared library, a dynamic relocation will
2080       // have been created for this location, so do not apply it now.
2081       if (!parameters->options().shared())
2082         {
2083           gold_assert(tls_segment != NULL);
2084           value -= tls_segment->memsz();
2085           Relocate_functions<32, false>::rel32(view, value);
2086         }
2087       break;
2088
2089     case elfcpp::R_386_TLS_LE_32:
2090       // If we're creating a shared library, a dynamic relocation will
2091       // have been created for this location, so do not apply it now.
2092       if (!parameters->options().shared())
2093         {
2094           gold_assert(tls_segment != NULL);
2095           value = tls_segment->memsz() - value;
2096           Relocate_functions<32, false>::rel32(view, value);
2097         }
2098       break;
2099     }
2100 }
2101
2102 // Do a relocation in which we convert a TLS General-Dynamic to a
2103 // Local-Exec.
2104
2105 inline void
2106 Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo,
2107                                     size_t relnum,
2108                                     Output_segment* tls_segment,
2109                                     const elfcpp::Rel<32, false>& rel,
2110                                     unsigned int,
2111                                     elfcpp::Elf_types<32>::Elf_Addr value,
2112                                     unsigned char* view,
2113                                     section_size_type view_size)
2114 {
2115   // leal foo(,%reg,1),%eax; call ___tls_get_addr
2116   //  ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2117   // leal foo(%reg),%eax; call ___tls_get_addr
2118   //  ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2119
2120   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2121   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2122
2123   unsigned char op1 = view[-1];
2124   unsigned char op2 = view[-2];
2125
2126   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2127                  op2 == 0x8d || op2 == 0x04);
2128   tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2129
2130   int roff = 5;
2131
2132   if (op2 == 0x04)
2133     {
2134       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
2135       tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
2136       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2137                      ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
2138       memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2139     }
2140   else
2141     {
2142       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2143                      (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
2144       if (rel.get_r_offset() + 9 < view_size
2145           && view[9] == 0x90)
2146         {
2147           // There is a trailing nop.  Use the size byte subl.
2148           memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2149           roff = 6;
2150         }
2151       else
2152         {
2153           // Use the five byte subl.
2154           memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2155         }
2156     }
2157
2158   value = tls_segment->memsz() - value;
2159   Relocate_functions<32, false>::rel32(view + roff, value);
2160
2161   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2162   // We can skip it.
2163   this->skip_call_tls_get_addr_ = true;
2164 }
2165
2166 // Do a relocation in which we convert a TLS General-Dynamic to an
2167 // Initial-Exec.
2168
2169 inline void
2170 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info<32, false>* relinfo,
2171                                     size_t relnum,
2172                                     Output_segment*,
2173                                     const elfcpp::Rel<32, false>& rel,
2174                                     unsigned int,
2175                                     elfcpp::Elf_types<32>::Elf_Addr value,
2176                                     unsigned char* view,
2177                                     section_size_type view_size)
2178 {
2179   // leal foo(,%ebx,1),%eax; call ___tls_get_addr
2180   //  ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
2181
2182   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2183   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2184
2185   unsigned char op1 = view[-1];
2186   unsigned char op2 = view[-2];
2187
2188   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2189                  op2 == 0x8d || op2 == 0x04);
2190   tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2191
2192   int roff = 5;
2193
2194   // FIXME: For now, support only the first (SIB) form.
2195   tls::check_tls(relinfo, relnum, rel.get_r_offset(), op2 == 0x04);
2196
2197   if (op2 == 0x04)
2198     {
2199       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
2200       tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
2201       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2202                      ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
2203       memcpy(view - 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
2204     }
2205   else
2206     {
2207       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2208                      (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
2209       if (rel.get_r_offset() + 9 < view_size
2210           && view[9] == 0x90)
2211         {
2212           // FIXME: This is not the right instruction sequence.
2213           // There is a trailing nop.  Use the size byte subl.
2214           memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2215           roff = 6;
2216         }
2217       else
2218         {
2219           // FIXME: This is not the right instruction sequence.
2220           // Use the five byte subl.
2221           memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2222         }
2223     }
2224
2225   Relocate_functions<32, false>::rel32(view + roff, value);
2226
2227   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2228   // We can skip it.
2229   this->skip_call_tls_get_addr_ = true;
2230 }
2231
2232 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2233 // General-Dynamic to a Local-Exec.
2234
2235 inline void
2236 Target_i386::Relocate::tls_desc_gd_to_le(
2237     const Relocate_info<32, false>* relinfo,
2238     size_t relnum,
2239     Output_segment* tls_segment,
2240     const elfcpp::Rel<32, false>& rel,
2241     unsigned int r_type,
2242     elfcpp::Elf_types<32>::Elf_Addr value,
2243     unsigned char* view,
2244     section_size_type view_size)
2245 {
2246   if (r_type == elfcpp::R_386_TLS_GOTDESC)
2247     {
2248       // leal foo@TLSDESC(%ebx), %eax
2249       // ==> leal foo@NTPOFF, %eax
2250       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2251       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2252       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2253                      view[-2] == 0x8d && view[-1] == 0x83);
2254       view[-1] = 0x05;
2255       value -= tls_segment->memsz();
2256       Relocate_functions<32, false>::rel32(view, value);
2257     }
2258   else
2259     {
2260       // call *foo@TLSCALL(%eax)
2261       // ==> nop; nop
2262       gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
2263       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
2264       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2265                      view[0] == 0xff && view[1] == 0x10);
2266       view[0] = 0x66;
2267       view[1] = 0x90;
2268     }
2269 }
2270
2271 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2272 // General-Dynamic to an Initial-Exec.
2273
2274 inline void
2275 Target_i386::Relocate::tls_desc_gd_to_ie(
2276     const Relocate_info<32, false>* relinfo,
2277     size_t relnum,
2278     Output_segment*,
2279     const elfcpp::Rel<32, false>& rel,
2280     unsigned int r_type,
2281     elfcpp::Elf_types<32>::Elf_Addr value,
2282     unsigned char* view,
2283     section_size_type view_size)
2284 {
2285   if (r_type == elfcpp::R_386_TLS_GOTDESC)
2286     {
2287       // leal foo@TLSDESC(%ebx), %eax
2288       // ==> movl foo@GOTNTPOFF(%ebx), %eax
2289       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2290       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2291       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2292                      view[-2] == 0x8d && view[-1] == 0x83);
2293       view[-2] = 0x8b;
2294       Relocate_functions<32, false>::rel32(view, value);
2295     }
2296   else
2297     {
2298       // call *foo@TLSCALL(%eax)
2299       // ==> nop; nop
2300       gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
2301       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
2302       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2303                      view[0] == 0xff && view[1] == 0x10);
2304       view[0] = 0x66;
2305       view[1] = 0x90;
2306     }
2307 }
2308
2309 // Do a relocation in which we convert a TLS Local-Dynamic to a
2310 // Local-Exec.
2311
2312 inline void
2313 Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo,
2314                                     size_t relnum,
2315                                     Output_segment*,
2316                                     const elfcpp::Rel<32, false>& rel,
2317                                     unsigned int,
2318                                     elfcpp::Elf_types<32>::Elf_Addr,
2319                                     unsigned char* view,
2320                                     section_size_type view_size)
2321 {
2322   // leal foo(%reg), %eax; call ___tls_get_addr
2323   // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
2324
2325   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2326   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2327
2328   // FIXME: Does this test really always pass?
2329   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2330                  view[-2] == 0x8d && view[-1] == 0x83);
2331
2332   tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2333
2334   memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
2335
2336   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2337   // We can skip it.
2338   this->skip_call_tls_get_addr_ = true;
2339 }
2340
2341 // Do a relocation in which we convert a TLS Initial-Exec to a
2342 // Local-Exec.
2343
2344 inline void
2345 Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo,
2346                                     size_t relnum,
2347                                     Output_segment* tls_segment,
2348                                     const elfcpp::Rel<32, false>& rel,
2349                                     unsigned int r_type,
2350                                     elfcpp::Elf_types<32>::Elf_Addr value,
2351                                     unsigned char* view,
2352                                     section_size_type view_size)
2353 {
2354   // We have to actually change the instructions, which means that we
2355   // need to examine the opcodes to figure out which instruction we
2356   // are looking at.
2357   if (r_type == elfcpp::R_386_TLS_IE)
2358     {
2359       // movl %gs:XX,%eax  ==>  movl $YY,%eax
2360       // movl %gs:XX,%reg  ==>  movl $YY,%reg
2361       // addl %gs:XX,%reg  ==>  addl $YY,%reg
2362       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -1);
2363       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2364
2365       unsigned char op1 = view[-1];
2366       if (op1 == 0xa1)
2367         {
2368           // movl XX,%eax  ==>  movl $YY,%eax
2369           view[-1] = 0xb8;
2370         }
2371       else
2372         {
2373           tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2374
2375           unsigned char op2 = view[-2];
2376           if (op2 == 0x8b)
2377             {
2378               // movl XX,%reg  ==>  movl $YY,%reg
2379               tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2380                              (op1 & 0xc7) == 0x05);
2381               view[-2] = 0xc7;
2382               view[-1] = 0xc0 | ((op1 >> 3) & 7);
2383             }
2384           else if (op2 == 0x03)
2385             {
2386               // addl XX,%reg  ==>  addl $YY,%reg
2387               tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2388                              (op1 & 0xc7) == 0x05);
2389               view[-2] = 0x81;
2390               view[-1] = 0xc0 | ((op1 >> 3) & 7);
2391             }
2392           else
2393             tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
2394         }
2395     }
2396   else
2397     {
2398       // subl %gs:XX(%reg1),%reg2  ==>  subl $YY,%reg2
2399       // movl %gs:XX(%reg1),%reg2  ==>  movl $YY,%reg2
2400       // addl %gs:XX(%reg1),%reg2  ==>  addl $YY,$reg2
2401       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2402       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2403
2404       unsigned char op1 = view[-1];
2405       unsigned char op2 = view[-2];
2406       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2407                      (op1 & 0xc0) == 0x80 && (op1 & 7) != 4);
2408       if (op2 == 0x8b)
2409         {
2410           // movl %gs:XX(%reg1),%reg2  ==>  movl $YY,%reg2
2411           view[-2] = 0xc7;
2412           view[-1] = 0xc0 | ((op1 >> 3) & 7);
2413         }
2414       else if (op2 == 0x2b)
2415         {
2416           // subl %gs:XX(%reg1),%reg2  ==>  subl $YY,%reg2
2417           view[-2] = 0x81;
2418           view[-1] = 0xe8 | ((op1 >> 3) & 7);
2419         }
2420       else if (op2 == 0x03)
2421         {
2422           // addl %gs:XX(%reg1),%reg2  ==>  addl $YY,$reg2
2423           view[-2] = 0x81;
2424           view[-1] = 0xc0 | ((op1 >> 3) & 7);
2425         }
2426       else
2427         tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
2428     }
2429
2430   value = tls_segment->memsz() - value;
2431   if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE)
2432     value = - value;
2433
2434   Relocate_functions<32, false>::rel32(view, value);
2435 }
2436
2437 // If we see an LDM reloc after we handled any LDO_32 relocs, fix up
2438 // the LDO_32 relocs.
2439
2440 void
2441 Target_i386::Relocate::fix_up_ldo(const Relocate_info<32, false>* relinfo)
2442 {
2443   if (this->ldo_addrs_.empty())
2444     return;
2445   Output_segment* tls_segment = relinfo->layout->tls_segment();
2446   gold_assert(tls_segment != NULL);
2447   elfcpp::Elf_types<32>::Elf_Addr value = - tls_segment->memsz();
2448   for (std::vector<unsigned char*>::const_iterator p = this->ldo_addrs_.begin();
2449        p != this->ldo_addrs_.end();
2450        ++p)
2451     Relocate_functions<32, false>::rel32(*p, value);
2452   this->ldo_addrs_.clear();
2453 }
2454
2455 // Relocate section data.
2456
2457 void
2458 Target_i386::relocate_section(const Relocate_info<32, false>* relinfo,
2459                               unsigned int sh_type,
2460                               const unsigned char* prelocs,
2461                               size_t reloc_count,
2462                               Output_section* output_section,
2463                               bool needs_special_offset_handling,
2464                               unsigned char* view,
2465                               elfcpp::Elf_types<32>::Elf_Addr address,
2466                               section_size_type view_size)
2467 {
2468   gold_assert(sh_type == elfcpp::SHT_REL);
2469
2470   gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL,
2471                          Target_i386::Relocate>(
2472     relinfo,
2473     this,
2474     prelocs,
2475     reloc_count,
2476     output_section,
2477     needs_special_offset_handling,
2478     view,
2479     address,
2480     view_size);
2481 }
2482
2483 // Return the size of a relocation while scanning during a relocatable
2484 // link.
2485
2486 unsigned int
2487 Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
2488     unsigned int r_type,
2489     Relobj* object)
2490 {
2491   switch (r_type)
2492     {
2493     case elfcpp::R_386_NONE:
2494     case elfcpp::R_386_GNU_VTINHERIT:
2495     case elfcpp::R_386_GNU_VTENTRY:
2496     case elfcpp::R_386_TLS_GD:            // Global-dynamic
2497     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
2498     case elfcpp::R_386_TLS_DESC_CALL:
2499     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
2500     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
2501     case elfcpp::R_386_TLS_IE:            // Initial-exec
2502     case elfcpp::R_386_TLS_IE_32:
2503     case elfcpp::R_386_TLS_GOTIE:
2504     case elfcpp::R_386_TLS_LE:            // Local-exec
2505     case elfcpp::R_386_TLS_LE_32:
2506       return 0;
2507
2508     case elfcpp::R_386_32:
2509     case elfcpp::R_386_PC32:
2510     case elfcpp::R_386_GOT32:
2511     case elfcpp::R_386_PLT32:
2512     case elfcpp::R_386_GOTOFF:
2513     case elfcpp::R_386_GOTPC:
2514      return 4;
2515
2516     case elfcpp::R_386_16:
2517     case elfcpp::R_386_PC16:
2518       return 2;
2519
2520     case elfcpp::R_386_8:
2521     case elfcpp::R_386_PC8:
2522       return 1;
2523
2524       // These are relocations which should only be seen by the
2525       // dynamic linker, and should never be seen here.
2526     case elfcpp::R_386_COPY:
2527     case elfcpp::R_386_GLOB_DAT:
2528     case elfcpp::R_386_JUMP_SLOT:
2529     case elfcpp::R_386_RELATIVE:
2530     case elfcpp::R_386_TLS_TPOFF:
2531     case elfcpp::R_386_TLS_DTPMOD32:
2532     case elfcpp::R_386_TLS_DTPOFF32:
2533     case elfcpp::R_386_TLS_TPOFF32:
2534     case elfcpp::R_386_TLS_DESC:
2535       object->error(_("unexpected reloc %u in object file"), r_type);
2536       return 0;
2537
2538     case elfcpp::R_386_32PLT:
2539     case elfcpp::R_386_TLS_GD_32:
2540     case elfcpp::R_386_TLS_GD_PUSH:
2541     case elfcpp::R_386_TLS_GD_CALL:
2542     case elfcpp::R_386_TLS_GD_POP:
2543     case elfcpp::R_386_TLS_LDM_32:
2544     case elfcpp::R_386_TLS_LDM_PUSH:
2545     case elfcpp::R_386_TLS_LDM_CALL:
2546     case elfcpp::R_386_TLS_LDM_POP:
2547     case elfcpp::R_386_USED_BY_INTEL_200:
2548     default:
2549       object->error(_("unsupported reloc %u in object file"), r_type);
2550       return 0;
2551     }
2552 }
2553
2554 // Scan the relocs during a relocatable link.
2555
2556 void
2557 Target_i386::scan_relocatable_relocs(const General_options& options,
2558                                      Symbol_table* symtab,
2559                                      Layout* layout,
2560                                      Sized_relobj<32, false>* object,
2561                                      unsigned int data_shndx,
2562                                      unsigned int sh_type,
2563                                      const unsigned char* prelocs,
2564                                      size_t reloc_count,
2565                                      Output_section* output_section,
2566                                      bool needs_special_offset_handling,
2567                                      size_t local_symbol_count,
2568                                      const unsigned char* plocal_symbols,
2569                                      Relocatable_relocs* rr)
2570 {
2571   gold_assert(sh_type == elfcpp::SHT_REL);
2572
2573   typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_REL,
2574     Relocatable_size_for_reloc> Scan_relocatable_relocs;
2575
2576   gold::scan_relocatable_relocs<32, false, elfcpp::SHT_REL,
2577       Scan_relocatable_relocs>(
2578     options,
2579     symtab,
2580     layout,
2581     object,
2582     data_shndx,
2583     prelocs,
2584     reloc_count,
2585     output_section,
2586     needs_special_offset_handling,
2587     local_symbol_count,
2588     plocal_symbols,
2589     rr);
2590 }
2591
2592 // Relocate a section during a relocatable link.
2593
2594 void
2595 Target_i386::relocate_for_relocatable(
2596     const Relocate_info<32, false>* relinfo,
2597     unsigned int sh_type,
2598     const unsigned char* prelocs,
2599     size_t reloc_count,
2600     Output_section* output_section,
2601     off_t offset_in_output_section,
2602     const Relocatable_relocs* rr,
2603     unsigned char* view,
2604     elfcpp::Elf_types<32>::Elf_Addr view_address,
2605     section_size_type view_size,
2606     unsigned char* reloc_view,
2607     section_size_type reloc_view_size)
2608 {
2609   gold_assert(sh_type == elfcpp::SHT_REL);
2610
2611   gold::relocate_for_relocatable<32, false, elfcpp::SHT_REL>(
2612     relinfo,
2613     prelocs,
2614     reloc_count,
2615     output_section,
2616     offset_in_output_section,
2617     rr,
2618     view,
2619     view_address,
2620     view_size,
2621     reloc_view,
2622     reloc_view_size);
2623 }
2624
2625 // Return the value to use for a dynamic which requires special
2626 // treatment.  This is how we support equality comparisons of function
2627 // pointers across shared library boundaries, as described in the
2628 // processor specific ABI supplement.
2629
2630 uint64_t
2631 Target_i386::do_dynsym_value(const Symbol* gsym) const
2632 {
2633   gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
2634   return this->plt_section()->address() + gsym->plt_offset();
2635 }
2636
2637 // Return a string used to fill a code section with nops to take up
2638 // the specified length.
2639
2640 std::string
2641 Target_i386::do_code_fill(section_size_type length) const
2642 {
2643   if (length >= 16)
2644     {
2645       // Build a jmp instruction to skip over the bytes.
2646       unsigned char jmp[5];
2647       jmp[0] = 0xe9;
2648       elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
2649       return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
2650               + std::string(length - 5, '\0'));
2651     }
2652
2653   // Nop sequences of various lengths.
2654   const char nop1[1] = { 0x90 };                   // nop
2655   const char nop2[2] = { 0x66, 0x90 };             // xchg %ax %ax
2656   const char nop3[3] = { 0x8d, 0x76, 0x00 };       // leal 0(%esi),%esi
2657   const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00};  // leal 0(%esi,1),%esi
2658   const char nop5[5] = { 0x90, 0x8d, 0x74, 0x26,   // nop
2659                          0x00 };                   // leal 0(%esi,1),%esi
2660   const char nop6[6] = { 0x8d, 0xb6, 0x00, 0x00,   // leal 0L(%esi),%esi
2661                          0x00, 0x00 };
2662   const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00,   // leal 0L(%esi,1),%esi
2663                          0x00, 0x00, 0x00 };
2664   const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26,   // nop
2665                          0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
2666   const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc,   // movl %esi,%esi
2667                          0x27, 0x00, 0x00, 0x00,   // leal 0L(%edi,1),%edi
2668                          0x00 };
2669   const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
2670                            0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
2671                            0x00, 0x00 };
2672   const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
2673                            0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
2674                            0x00, 0x00, 0x00 };
2675   const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2676                            0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
2677                            0x00, 0x00, 0x00, 0x00 };
2678   const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2679                            0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
2680                            0x27, 0x00, 0x00, 0x00,
2681                            0x00 };
2682   const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2683                            0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
2684                            0xbc, 0x27, 0x00, 0x00,
2685                            0x00, 0x00 };
2686   const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
2687                            0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
2688                            0x90, 0x90, 0x90, 0x90,
2689                            0x90, 0x90, 0x90 };
2690
2691   const char* nops[16] = {
2692     NULL,
2693     nop1, nop2, nop3, nop4, nop5, nop6, nop7,
2694     nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
2695   };
2696
2697   return std::string(nops[length], length);
2698 }
2699
2700 // The selector for i386 object files.
2701
2702 class Target_selector_i386 : public Target_selector_freebsd
2703 {
2704 public:
2705   Target_selector_i386()
2706     : Target_selector_freebsd(elfcpp::EM_386, 32, false,
2707                               "elf32-i386", "elf32-i386-freebsd")
2708   { }
2709
2710   Target*
2711   do_instantiate_target()
2712   { return new Target_i386(); }
2713 };
2714
2715 Target_selector_i386 target_selector_i386;
2716
2717 } // End anonymous namespace.