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