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 #include "gc.h"
  42
  43 namespace
  44 {
  45
  46 using namespace gold;
  47
  48 class Output_data_plt_i386;
  49
  50 // The i386 target class.
  51 // TLS info comes from
  52 //   http://people.redhat.com/drepper/tls.pdf
  53 //   http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
  54
  55 class Target_i386 : public Target_freebsd<32, false>
  56 {
  57  public:
  58   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
  59
  60   Target_i386()
  61     : Target_freebsd<32, false>(&i386_info),
  62       got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
  63       copy_relocs_(elfcpp::R_386_COPY), dynbss_(NULL),
  64       got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
  65   { }
  66
  67   // Process the relocations to determine unreferenced sections for
  68   // garbage collection.
  69   void
  70   gc_process_relocs(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(Symbol_table* symtab,
  85               Layout* layout,
  86               Sized_relobj<32, false>* object,
  87               unsigned int data_shndx,
  88               unsigned int sh_type,
  89               const unsigned char* prelocs,
  90               size_t reloc_count,
  91               Output_section* output_section,
  92               bool needs_special_offset_handling,
  93               size_t local_symbol_count,
  94               const unsigned char* plocal_symbols);
  95
  96   // Finalize the sections.
  97   void
  98   do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
  99
 100   // Return the value to use for a dynamic which requires special
 101   // treatment.
 102   uint64_t
 103   do_dynsym_value(const Symbol*) const;
 104
 105   // Relocate a section.
 106   void
 107   relocate_section(const Relocate_info<32, false>*,
 108                    unsigned int sh_type,
 109                    const unsigned char* prelocs,
 110                    size_t reloc_count,
 111                    Output_section* output_section,
 112                    bool needs_special_offset_handling,
 113                    unsigned char* view,
 114                    elfcpp::Elf_types<32>::Elf_Addr view_address,
 115                    section_size_type view_size,
 116                    const Reloc_symbol_changes*);
 117
 118   // Scan the relocs during a relocatable link.
 119   void
 120   scan_relocatable_relocs(Symbol_table* symtab,
 121                           Layout* layout,
 122                           Sized_relobj<32, false>* object,
 123                           unsigned int data_shndx,
 124                           unsigned int sh_type,
 125                           const unsigned char* prelocs,
 126                           size_t reloc_count,
 127                           Output_section* output_section,
 128                           bool needs_special_offset_handling,
 129                           size_t local_symbol_count,
 130                           const unsigned char* plocal_symbols,
 131                           Relocatable_relocs*);
 132
 133   // Relocate a section during a relocatable link.
 134   void
 135   relocate_for_relocatable(const Relocate_info<32, false>*,
 136                            unsigned int sh_type,
 137                            const unsigned char* prelocs,
 138                            size_t reloc_count,
 139                            Output_section* output_section,
 140                            off_t offset_in_output_section,
 141                            const Relocatable_relocs*,
 142                            unsigned char* view,
 143                            elfcpp::Elf_types<32>::Elf_Addr view_address,
 144                            section_size_type view_size,
 145                            unsigned char* reloc_view,
 146                            section_size_type reloc_view_size);
 147
 148   // Return a string used to fill a code section with nops.
 149   std::string
 150   do_code_fill(section_size_type length) const;
 151
 152   // Return whether SYM is defined by the ABI.
 153   bool
 154   do_is_defined_by_abi(const Symbol* sym) const
 155   { return strcmp(sym->name(), "___tls_get_addr") == 0; }
 156
 157   // Return whether a symbol name implies a local label.  The UnixWare
 158   // 2.1 cc generates temporary symbols that start with .X, so we
 159   // recognize them here.  FIXME: do other SVR4 compilers also use .X?.
 160   // If so, we should move the .X recognition into
 161   // Target::do_is_local_label_name.
 162   bool
 163   do_is_local_label_name(const char* name) const
 164   {
 165     if (name[0] == '.' && name[1] == 'X')
 166       return true;
 167     return Target::do_is_local_label_name(name);
 168   }
 169
 170   // Adjust -fstack-split code which calls non-stack-split code.
 171   void
 172   do_calls_non_split(Relobj* object, unsigned int shndx,
 173                      section_offset_type fnoffset, section_size_type fnsize,
 174                      unsigned char* view, section_size_type view_size,
 175                      std::string* from, std::string* to) const;
 176
 177   // Return the size of the GOT section.
 178   section_size_type
 179   got_size()
 180   {
 181     gold_assert(this->got_ != NULL);
 182     return this->got_->data_size();
 183   }
 184
 185  private:
 186   // The class which scans relocations.
 187   struct Scan
 188   {
 189     inline void
 190     local(Symbol_table* symtab, Layout* layout, Target_i386* target,
 191           Sized_relobj<32, false>* object,
 192           unsigned int data_shndx,
 193           Output_section* output_section,
 194           const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
 195           const elfcpp::Sym<32, false>& lsym);
 196
 197     inline void
 198     global(Symbol_table* symtab, Layout* layout, Target_i386* target,
 199            Sized_relobj<32, false>* object,
 200            unsigned int data_shndx,
 201            Output_section* output_section,
 202            const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
 203            Symbol* gsym);
 204
 205     static void
 206     unsupported_reloc_local(Sized_relobj<32, false>*, unsigned int r_type);
 207
 208     static void
 209     unsupported_reloc_global(Sized_relobj<32, false>*, unsigned int r_type,
 210                              Symbol*);
 211   };
 212
 213   // The class which implements relocation.
 214   class Relocate
 215   {
 216    public:
 217     Relocate()
 218       : skip_call_tls_get_addr_(false),
 219         local_dynamic_type_(LOCAL_DYNAMIC_NONE)
 220     { }
 221
 222     ~Relocate()
 223     {
 224       if (this->skip_call_tls_get_addr_)
 225         {
 226           // FIXME: This needs to specify the location somehow.
 227           gold_error(_("missing expected TLS relocation"));
 228         }
 229     }
 230
 231     // Return whether the static relocation needs to be applied.
 232     inline bool
 233     should_apply_static_reloc(const Sized_symbol<32>* gsym,
 234                               int ref_flags,
 235                               bool is_32bit,
 236                               Output_section* output_section);
 237
 238     // Do a relocation.  Return false if the caller should not issue
 239     // any warnings about this relocation.
 240     inline bool
 241     relocate(const Relocate_info<32, false>*, Target_i386*, Output_section*,
 242              size_t relnum, const elfcpp::Rel<32, false>&,
 243              unsigned int r_type, const Sized_symbol<32>*,
 244              const Symbol_value<32>*,
 245              unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
 246              section_size_type);
 247
 248    private:
 249     // Do a TLS relocation.
 250     inline void
 251     relocate_tls(const Relocate_info<32, false>*, Target_i386* target,
 252                  size_t relnum, const elfcpp::Rel<32, false>&,
 253                  unsigned int r_type, const Sized_symbol<32>*,
 254                  const Symbol_value<32>*,
 255                  unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
 256                  section_size_type);
 257
 258     // Do a TLS General-Dynamic to Initial-Exec transition.
 259     inline void
 260     tls_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
 261                  Output_segment* tls_segment,
 262                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 263                  elfcpp::Elf_types<32>::Elf_Addr value,
 264                  unsigned char* view,
 265                  section_size_type view_size);
 266
 267     // Do a TLS General-Dynamic to Local-Exec transition.
 268     inline void
 269     tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
 270                  Output_segment* tls_segment,
 271                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 272                  elfcpp::Elf_types<32>::Elf_Addr value,
 273                  unsigned char* view,
 274                  section_size_type view_size);
 275
 276     // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
 277     // transition.
 278     inline void
 279     tls_desc_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
 280                       Output_segment* tls_segment,
 281                       const elfcpp::Rel<32, false>&, unsigned int r_type,
 282                       elfcpp::Elf_types<32>::Elf_Addr value,
 283                       unsigned char* view,
 284                       section_size_type view_size);
 285
 286     // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
 287     // transition.
 288     inline void
 289     tls_desc_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
 290                       Output_segment* tls_segment,
 291                       const elfcpp::Rel<32, false>&, unsigned int r_type,
 292                       elfcpp::Elf_types<32>::Elf_Addr value,
 293                       unsigned char* view,
 294                       section_size_type view_size);
 295
 296     // Do a TLS Local-Dynamic to Local-Exec transition.
 297     inline void
 298     tls_ld_to_le(const Relocate_info<32, false>*, size_t relnum,
 299                  Output_segment* tls_segment,
 300                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 301                  elfcpp::Elf_types<32>::Elf_Addr value,
 302                  unsigned char* view,
 303                  section_size_type view_size);
 304
 305     // Do a TLS Initial-Exec to Local-Exec transition.
 306     static inline void
 307     tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum,
 308                  Output_segment* tls_segment,
 309                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 310                  elfcpp::Elf_types<32>::Elf_Addr value,
 311                  unsigned char* view,
 312                  section_size_type view_size);
 313
 314     // We need to keep track of which type of local dynamic relocation
 315     // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
 316     enum Local_dynamic_type
 317     {
 318       LOCAL_DYNAMIC_NONE,
 319       LOCAL_DYNAMIC_SUN,
 320       LOCAL_DYNAMIC_GNU
 321     };
 322
 323     // This is set if we should skip the next reloc, which should be a
 324     // PLT32 reloc against ___tls_get_addr.
 325     bool skip_call_tls_get_addr_;
 326     // The type of local dynamic relocation we have seen in the section
 327     // being relocated, if any.
 328     Local_dynamic_type local_dynamic_type_;
 329   };
 330
 331   // A class which returns the size required for a relocation type,
 332   // used while scanning relocs during a relocatable link.
 333   class Relocatable_size_for_reloc
 334   {
 335    public:
 336     unsigned int
 337     get_size_for_reloc(unsigned int, Relobj*);
 338   };
 339
 340   // Adjust TLS relocation type based on the options and whether this
 341   // is a local symbol.
 342   static tls::Tls_optimization
 343   optimize_tls_reloc(bool is_final, int r_type);
 344
 345   // Get the GOT section, creating it if necessary.
 346   Output_data_got<32, false>*
 347   got_section(Symbol_table*, Layout*);
 348
 349   // Get the GOT PLT section.
 350   Output_data_space*
 351   got_plt_section() const
 352   {
 353     gold_assert(this->got_plt_ != NULL);
 354     return this->got_plt_;
 355   }
 356
 357   // Create a PLT entry for a global symbol.
 358   void
 359   make_plt_entry(Symbol_table*, Layout*, Symbol*);
 360
 361   // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
 362   void
 363   define_tls_base_symbol(Symbol_table*, Layout*);
 364
 365   // Create a GOT entry for the TLS module index.
 366   unsigned int
 367   got_mod_index_entry(Symbol_table* symtab, Layout* layout,
 368                       Sized_relobj<32, false>* object);
 369
 370   // Get the PLT section.
 371   const Output_data_plt_i386*
 372   plt_section() const
 373   {
 374     gold_assert(this->plt_ != NULL);
 375     return this->plt_;
 376   }
 377
 378   // Get the dynamic reloc section, creating it if necessary.
 379   Reloc_section*
 380   rel_dyn_section(Layout*);
 381
 382   // Add a potential copy relocation.
 383   void
 384   copy_reloc(Symbol_table* symtab, Layout* layout,
 385              Sized_relobj<32, false>* object,
 386              unsigned int shndx, Output_section* output_section,
 387              Symbol* sym, const elfcpp::Rel<32, false>& reloc)
 388   {
 389     this->copy_relocs_.copy_reloc(symtab, layout,
 390                                   symtab->get_sized_symbol<32>(sym),
 391                                   object, shndx, output_section, reloc,
 392                                   this->rel_dyn_section(layout));
 393   }
 394
 395   // Information about this specific target which we pass to the
 396   // general Target structure.
 397   static const Target::Target_info i386_info;
 398
 399   // The types of GOT entries needed for this platform.
 400   enum Got_type
 401   {
 402     GOT_TYPE_STANDARD = 0,      // GOT entry for a regular symbol
 403     GOT_TYPE_TLS_NOFFSET = 1,   // GOT entry for negative TLS offset
 404     GOT_TYPE_TLS_OFFSET = 2,    // GOT entry for positive TLS offset
 405     GOT_TYPE_TLS_PAIR = 3,      // GOT entry for TLS module/offset pair
 406     GOT_TYPE_TLS_DESC = 4       // GOT entry for TLS_DESC pair
 407   };
 408
 409   // The GOT section.
 410   Output_data_got<32, false>* got_;
 411   // The PLT section.
 412   Output_data_plt_i386* plt_;
 413   // The GOT PLT section.
 414   Output_data_space* got_plt_;
 415   // The dynamic reloc section.
 416   Reloc_section* rel_dyn_;
 417   // Relocs saved to avoid a COPY reloc.
 418   Copy_relocs<elfcpp::SHT_REL, 32, false> copy_relocs_;
 419   // Space for variables copied with a COPY reloc.
 420   Output_data_space* dynbss_;
 421   // Offset of the GOT entry for the TLS module index.
 422   unsigned int got_mod_index_offset_;
 423   // True if the _TLS_MODULE_BASE_ symbol has been defined.
 424   bool tls_base_symbol_defined_;
 425 };
 426
 427 const Target::Target_info Target_i386::i386_info =
 428 {
 429   32,                   // size
 430   false,                // is_big_endian
 431   elfcpp::EM_386,       // machine_code
 432   false,                // has_make_symbol
 433   false,                // has_resolve
 434   true,                 // has_code_fill
 435   true,                 // is_default_stack_executable
 436   '\0',                 // wrap_char
 437   "/usr/lib/libc.so.1", // dynamic_linker
 438   0x08048000,           // default_text_segment_address
 439   0x1000,               // abi_pagesize (overridable by -z max-page-size)
 440   0x1000,               // common_pagesize (overridable by -z common-page-size)
 441   elfcpp::SHN_UNDEF,    // small_common_shndx
 442   elfcpp::SHN_UNDEF,    // large_common_shndx
 443   0,                    // small_common_section_flags
 444   0,                    // large_common_section_flags
 445   NULL,                 // attributes_section
 446   NULL                  // attributes_vendor
 447 };
 448
 449 // Get the GOT section, creating it if necessary.
 450
 451 Output_data_got<32, false>*
 452 Target_i386::got_section(Symbol_table* symtab, Layout* layout)
 453 {
 454   if (this->got_ == NULL)
 455     {
 456       gold_assert(symtab != NULL && layout != NULL);
 457
 458       this->got_ = new Output_data_got<32, false>();
 459
 460       Output_section* os;
 461       os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
 462                                            (elfcpp::SHF_ALLOC
 463                                             | elfcpp::SHF_WRITE),
 464                                            this->got_, false, true, true,
 465                                            false);
 466
 467       this->got_plt_ = new Output_data_space(4, "** GOT PLT");
 468       os = layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
 469                                            (elfcpp::SHF_ALLOC
 470                                             | elfcpp::SHF_WRITE),
 471                                            this->got_plt_, false, false, false,
 472                                            true);
 473
 474       // The first three entries are reserved.
 475       this->got_plt_->set_current_data_size(3 * 4);
 476
 477       // Those bytes can go into the relro segment.
 478       layout->increase_relro(3 * 4);
 479
 480       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
 481       symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
 482                                     Symbol_table::PREDEFINED,
 483                                     this->got_plt_,
 484                                     0, 0, elfcpp::STT_OBJECT,
 485                                     elfcpp::STB_LOCAL,
 486                                     elfcpp::STV_HIDDEN, 0,
 487                                     false, false);
 488     }
 489
 490   return this->got_;
 491 }
 492
 493 // Get the dynamic reloc section, creating it if necessary.
 494
 495 Target_i386::Reloc_section*
 496 Target_i386::rel_dyn_section(Layout* layout)
 497 {
 498   if (this->rel_dyn_ == NULL)
 499     {
 500       gold_assert(layout != NULL);
 501       this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
 502       layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
 503                                       elfcpp::SHF_ALLOC, this->rel_dyn_, true,
 504                                       false, false, false);
 505     }
 506   return this->rel_dyn_;
 507 }
 508
 509 // A class to handle the PLT data.
 510
 511 class Output_data_plt_i386 : public Output_section_data
 512 {
 513  public:
 514   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
 515
 516   Output_data_plt_i386(Layout*, Output_data_space*);
 517
 518   // Add an entry to the PLT.
 519   void
 520   add_entry(Symbol* gsym);
 521
 522   // Return the .rel.plt section data.
 523   const Reloc_section*
 524   rel_plt() const
 525   { return this->rel_; }
 526
 527  protected:
 528   void
 529   do_adjust_output_section(Output_section* os);
 530
 531   // Write to a map file.
 532   void
 533   do_print_to_mapfile(Mapfile* mapfile) const
 534   { mapfile->print_output_data(this, _("** PLT")); }
 535
 536  private:
 537   // The size of an entry in the PLT.
 538   static const int plt_entry_size = 16;
 539
 540   // The first entry in the PLT for an executable.
 541   static unsigned char exec_first_plt_entry[plt_entry_size];
 542
 543   // The first entry in the PLT for a shared object.
 544   static unsigned char dyn_first_plt_entry[plt_entry_size];
 545
 546   // Other entries in the PLT for an executable.
 547   static unsigned char exec_plt_entry[plt_entry_size];
 548
 549   // Other entries in the PLT for a shared object.
 550   static unsigned char dyn_plt_entry[plt_entry_size];
 551
 552   // Set the final size.
 553   void
 554   set_final_data_size()
 555   { this->set_data_size((this->count_ + 1) * plt_entry_size); }
 556
 557   // Write out the PLT data.
 558   void
 559   do_write(Output_file*);
 560
 561   // The reloc section.
 562   Reloc_section* rel_;
 563   // The .got.plt section.
 564   Output_data_space* got_plt_;
 565   // The number of PLT entries.
 566   unsigned int count_;
 567 };
 568
 569 // Create the PLT section.  The ordinary .got section is an argument,
 570 // since we need to refer to the start.  We also create our own .got
 571 // section just for PLT entries.
 572
 573 Output_data_plt_i386::Output_data_plt_i386(Layout* layout,
 574                                            Output_data_space* got_plt)
 575   : Output_section_data(4), got_plt_(got_plt), count_(0)
 576 {
 577   this->rel_ = new Reloc_section(false);
 578   layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
 579                                   elfcpp::SHF_ALLOC, this->rel_, true,
 580                                   false, false, false);
 581 }
 582
 583 void
 584 Output_data_plt_i386::do_adjust_output_section(Output_section* os)
 585 {
 586   // UnixWare sets the entsize of .plt to 4, and so does the old GNU
 587   // linker, and so do we.
 588   os->set_entsize(4);
 589 }
 590
 591 // Add an entry to the PLT.
 592
 593 void
 594 Output_data_plt_i386::add_entry(Symbol* gsym)
 595 {
 596   gold_assert(!gsym->has_plt_offset());
 597
 598   // Note that when setting the PLT offset we skip the initial
 599   // reserved PLT entry.
 600   gsym->set_plt_offset((this->count_ + 1) * plt_entry_size);
 601
 602   ++this->count_;
 603
 604   section_offset_type got_offset = this->got_plt_->current_data_size();
 605
 606   // Every PLT entry needs a GOT entry which points back to the PLT
 607   // entry (this will be changed by the dynamic linker, normally
 608   // lazily when the function is called).
 609   this->got_plt_->set_current_data_size(got_offset + 4);
 610
 611   // Every PLT entry needs a reloc.
 612   gsym->set_needs_dynsym_entry();
 613   this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_,
 614                          got_offset);
 615
 616   // Note that we don't need to save the symbol.  The contents of the
 617   // PLT are independent of which symbols are used.  The symbols only
 618   // appear in the relocations.
 619 }
 620
 621 // The first entry in the PLT for an executable.
 622
 623 unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] =
 624 {
 625   0xff, 0x35,   // pushl contents of memory address
 626   0, 0, 0, 0,   // replaced with address of .got + 4
 627   0xff, 0x25,   // jmp indirect
 628   0, 0, 0, 0,   // replaced with address of .got + 8
 629   0, 0, 0, 0    // unused
 630 };
 631
 632 // The first entry in the PLT for a shared object.
 633
 634 unsigned char Output_data_plt_i386::dyn_first_plt_entry[plt_entry_size] =
 635 {
 636   0xff, 0xb3, 4, 0, 0, 0,       // pushl 4(%ebx)
 637   0xff, 0xa3, 8, 0, 0, 0,       // jmp *8(%ebx)
 638   0, 0, 0, 0                    // unused
 639 };
 640
 641 // Subsequent entries in the PLT for an executable.
 642
 643 unsigned char Output_data_plt_i386::exec_plt_entry[plt_entry_size] =
 644 {
 645   0xff, 0x25,   // jmp indirect
 646   0, 0, 0, 0,   // replaced with address of symbol in .got
 647   0x68,         // pushl immediate
 648   0, 0, 0, 0,   // replaced with offset into relocation table
 649   0xe9,         // jmp relative
 650   0, 0, 0, 0    // replaced with offset to start of .plt
 651 };
 652
 653 // Subsequent entries in the PLT for a shared object.
 654
 655 unsigned char Output_data_plt_i386::dyn_plt_entry[plt_entry_size] =
 656 {
 657   0xff, 0xa3,   // jmp *offset(%ebx)
 658   0, 0, 0, 0,   // replaced with offset of symbol in .got
 659   0x68,         // pushl immediate
 660   0, 0, 0, 0,   // replaced with offset into relocation table
 661   0xe9,         // jmp relative
 662   0, 0, 0, 0    // replaced with offset to start of .plt
 663 };
 664
 665 // Write out the PLT.  This uses the hand-coded instructions above,
 666 // and adjusts them as needed.  This is all specified by the i386 ELF
 667 // Processor Supplement.
 668
 669 void
 670 Output_data_plt_i386::do_write(Output_file* of)
 671 {
 672   const off_t offset = this->offset();
 673   const section_size_type oview_size =
 674     convert_to_section_size_type(this->data_size());
 675   unsigned char* const oview = of->get_output_view(offset, oview_size);
 676
 677   const off_t got_file_offset = this->got_plt_->offset();
 678   const section_size_type got_size =
 679     convert_to_section_size_type(this->got_plt_->data_size());
 680   unsigned char* const got_view = of->get_output_view(got_file_offset,
 681                                                       got_size);
 682
 683   unsigned char* pov = oview;
 684
 685   elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address();
 686   elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address();
 687
 688   if (parameters->options().output_is_position_independent())
 689     memcpy(pov, dyn_first_plt_entry, plt_entry_size);
 690   else
 691     {
 692       memcpy(pov, exec_first_plt_entry, plt_entry_size);
 693       elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
 694       elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
 695     }
 696   pov += plt_entry_size;
 697
 698   unsigned char* got_pov = got_view;
 699
 700   memset(got_pov, 0, 12);
 701   got_pov += 12;
 702
 703   const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
 704
 705   unsigned int plt_offset = plt_entry_size;
 706   unsigned int plt_rel_offset = 0;
 707   unsigned int got_offset = 12;
 708   const unsigned int count = this->count_;
 709   for (unsigned int i = 0;
 710        i < count;
 711        ++i,
 712          pov += plt_entry_size,
 713          got_pov += 4,
 714          plt_offset += plt_entry_size,
 715          plt_rel_offset += rel_size,
 716          got_offset += 4)
 717     {
 718       // Set and adjust the PLT entry itself.
 719
 720       if (parameters->options().output_is_position_independent())
 721         {
 722           memcpy(pov, dyn_plt_entry, plt_entry_size);
 723           elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
 724         }
 725       else
 726         {
 727           memcpy(pov, exec_plt_entry, plt_entry_size);
 728           elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
 729                                                       (got_address
 730                                                        + got_offset));
 731         }
 732
 733       elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
 734       elfcpp::Swap<32, false>::writeval(pov + 12,
 735                                         - (plt_offset + plt_entry_size));
 736
 737       // Set the entry in the GOT.
 738       elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6);
 739     }
 740
 741   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
 742   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
 743
 744   of->write_output_view(offset, oview_size, oview);
 745   of->write_output_view(got_file_offset, got_size, got_view);
 746 }
 747
 748 // Create a PLT entry for a global symbol.
 749
 750 void
 751 Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym)
 752 {
 753   if (gsym->has_plt_offset())
 754     return;
 755
 756   if (this->plt_ == NULL)
 757     {
 758       // Create the GOT sections first.
 759       this->got_section(symtab, layout);
 760
 761       this->plt_ = new Output_data_plt_i386(layout, this->got_plt_);
 762       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
 763                                       (elfcpp::SHF_ALLOC
 764                                        | elfcpp::SHF_EXECINSTR),
 765                                       this->plt_, false, false, false, false);
 766     }
 767
 768   this->plt_->add_entry(gsym);
 769 }
 770
 771 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
 772
 773 void
 774 Target_i386::define_tls_base_symbol(Symbol_table* symtab, Layout* layout)
 775 {
 776   if (this->tls_base_symbol_defined_)
 777     return;
 778
 779   Output_segment* tls_segment = layout->tls_segment();
 780   if (tls_segment != NULL)
 781     {
 782       bool is_exec = parameters->options().output_is_executable();
 783       symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
 784                                        Symbol_table::PREDEFINED,
 785                                        tls_segment, 0, 0,
 786                                        elfcpp::STT_TLS,
 787                                        elfcpp::STB_LOCAL,
 788                                        elfcpp::STV_HIDDEN, 0,
 789                                        (is_exec
 790                                         ? Symbol::SEGMENT_END
 791                                         : Symbol::SEGMENT_START),
 792                                        true);
 793     }
 794   this->tls_base_symbol_defined_ = true;
 795 }
 796
 797 // Create a GOT entry for the TLS module index.
 798
 799 unsigned int
 800 Target_i386::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
 801                                  Sized_relobj<32, false>* object)
 802 {
 803   if (this->got_mod_index_offset_ == -1U)
 804     {
 805       gold_assert(symtab != NULL && layout != NULL && object != NULL);
 806       Reloc_section* rel_dyn = this->rel_dyn_section(layout);
 807       Output_data_got<32, false>* got = this->got_section(symtab, layout);
 808       unsigned int got_offset = got->add_constant(0);
 809       rel_dyn->add_local(object, 0, elfcpp::R_386_TLS_DTPMOD32, got,
 810                          got_offset);
 811       got->add_constant(0);
 812       this->got_mod_index_offset_ = got_offset;
 813     }
 814   return this->got_mod_index_offset_;
 815 }
 816
 817 // Optimize the TLS relocation type based on what we know about the
 818 // symbol.  IS_FINAL is true if the final address of this symbol is
 819 // known at link time.
 820
 821 tls::Tls_optimization
 822 Target_i386::optimize_tls_reloc(bool is_final, int r_type)
 823 {
 824   // If we are generating a shared library, then we can't do anything
 825   // in the linker.
 826   if (parameters->options().shared())
 827     return tls::TLSOPT_NONE;
 828
 829   switch (r_type)
 830     {
 831     case elfcpp::R_386_TLS_GD:
 832     case elfcpp::R_386_TLS_GOTDESC:
 833     case elfcpp::R_386_TLS_DESC_CALL:
 834       // These are General-Dynamic which permits fully general TLS
 835       // access.  Since we know that we are generating an executable,
 836       // we can convert this to Initial-Exec.  If we also know that
 837       // this is a local symbol, we can further switch to Local-Exec.
 838       if (is_final)
 839         return tls::TLSOPT_TO_LE;
 840       return tls::TLSOPT_TO_IE;
 841
 842     case elfcpp::R_386_TLS_LDM:
 843       // This is Local-Dynamic, which refers to a local symbol in the
 844       // dynamic TLS block.  Since we know that we generating an
 845       // executable, we can switch to Local-Exec.
 846       return tls::TLSOPT_TO_LE;
 847
 848     case elfcpp::R_386_TLS_LDO_32:
 849       // Another type of Local-Dynamic relocation.
 850       return tls::TLSOPT_TO_LE;
 851
 852     case elfcpp::R_386_TLS_IE:
 853     case elfcpp::R_386_TLS_GOTIE:
 854     case elfcpp::R_386_TLS_IE_32:
 855       // These are Initial-Exec relocs which get the thread offset
 856       // from the GOT.  If we know that we are linking against the
 857       // local symbol, we can switch to Local-Exec, which links the
 858       // thread offset into the instruction.
 859       if (is_final)
 860         return tls::TLSOPT_TO_LE;
 861       return tls::TLSOPT_NONE;
 862
 863     case elfcpp::R_386_TLS_LE:
 864     case elfcpp::R_386_TLS_LE_32:
 865       // When we already have Local-Exec, there is nothing further we
 866       // can do.
 867       return tls::TLSOPT_NONE;
 868
 869     default:
 870       gold_unreachable();
 871     }
 872 }
 873
 874 // Report an unsupported relocation against a local symbol.
 875
 876 void
 877 Target_i386::Scan::unsupported_reloc_local(Sized_relobj<32, false>* object,
 878                                            unsigned int r_type)
 879 {
 880   gold_error(_("%s: unsupported reloc %u against local symbol"),
 881              object->name().c_str(), r_type);
 882 }
 883
 884 // Scan a relocation for a local symbol.
 885
 886 inline void
 887 Target_i386::Scan::local(Symbol_table* symtab,
 888                          Layout* layout,
 889                          Target_i386* target,
 890                          Sized_relobj<32, false>* object,
 891                          unsigned int data_shndx,
 892                          Output_section* output_section,
 893                          const elfcpp::Rel<32, false>& reloc,
 894                          unsigned int r_type,
 895                          const elfcpp::Sym<32, false>& lsym)
 896 {
 897   switch (r_type)
 898     {
 899     case elfcpp::R_386_NONE:
 900     case elfcpp::R_386_GNU_VTINHERIT:
 901     case elfcpp::R_386_GNU_VTENTRY:
 902       break;
 903
 904     case elfcpp::R_386_32:
 905       // If building a shared library (or a position-independent
 906       // executable), we need to create a dynamic relocation for
 907       // this location. The relocation applied at link time will
 908       // apply the link-time value, so we flag the location with
 909       // an R_386_RELATIVE relocation so the dynamic loader can
 910       // relocate it easily.
 911       if (parameters->options().output_is_position_independent())
 912         {
 913           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
 914           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
 915           rel_dyn->add_local_relative(object, r_sym, elfcpp::R_386_RELATIVE,
 916                                       output_section, data_shndx,
 917                                       reloc.get_r_offset());
 918         }
 919       break;
 920
 921     case elfcpp::R_386_16:
 922     case elfcpp::R_386_8:
 923       // If building a shared library (or a position-independent
 924       // executable), we need to create a dynamic relocation for
 925       // this location. Because the addend needs to remain in the
 926       // data section, we need to be careful not to apply this
 927       // relocation statically.
 928       if (parameters->options().output_is_position_independent())
 929         {
 930           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
 931           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
 932           if (lsym.get_st_type() != elfcpp::STT_SECTION)
 933             rel_dyn->add_local(object, r_sym, r_type, output_section,
 934                                data_shndx, reloc.get_r_offset());
 935           else
 936             {
 937               gold_assert(lsym.get_st_value() == 0);
 938               unsigned int shndx = lsym.get_st_shndx();
 939               bool is_ordinary;
 940               shndx = object->adjust_sym_shndx(r_sym, shndx,
 941                                                &is_ordinary);
 942               if (!is_ordinary)
 943                 object->error(_("section symbol %u has bad shndx %u"),
 944                               r_sym, shndx);
 945               else
 946                 rel_dyn->add_local_section(object, shndx,
 947                                            r_type, output_section,
 948                                            data_shndx, reloc.get_r_offset());
 949             }
 950         }
 951       break;
 952
 953     case elfcpp::R_386_PC32:
 954     case elfcpp::R_386_PC16:
 955     case elfcpp::R_386_PC8:
 956       break;
 957
 958     case elfcpp::R_386_PLT32:
 959       // Since we know this is a local symbol, we can handle this as a
 960       // PC32 reloc.
 961       break;
 962
 963     case elfcpp::R_386_GOTOFF:
 964     case elfcpp::R_386_GOTPC:
 965       // We need a GOT section.
 966       target->got_section(symtab, layout);
 967       break;
 968
 969     case elfcpp::R_386_GOT32:
 970       {
 971         // The symbol requires a GOT entry.
 972         Output_data_got<32, false>* got = target->got_section(symtab, layout);
 973         unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
 974         if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
 975           {
 976             // If we are generating a shared object, we need to add a
 977             // dynamic RELATIVE relocation for this symbol's GOT entry.
 978             if (parameters->options().output_is_position_independent())
 979               {
 980                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
 981                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
 982                 rel_dyn->add_local_relative(
 983                     object, r_sym, elfcpp::R_386_RELATIVE, got,
 984                     object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
 985               }
 986           }
 987       }
 988       break;
 989
 990       // These are relocations which should only be seen by the
 991       // dynamic linker, and should never be seen here.
 992     case elfcpp::R_386_COPY:
 993     case elfcpp::R_386_GLOB_DAT:
 994     case elfcpp::R_386_JUMP_SLOT:
 995     case elfcpp::R_386_RELATIVE:
 996     case elfcpp::R_386_TLS_TPOFF:
 997     case elfcpp::R_386_TLS_DTPMOD32:
 998     case elfcpp::R_386_TLS_DTPOFF32:
 999     case elfcpp::R_386_TLS_TPOFF32:
1000     case elfcpp::R_386_TLS_DESC:
1001       gold_error(_("%s: unexpected reloc %u in object file"),
1002                  object->name().c_str(), r_type);
1003       break;
1004
1005       // These are initial TLS relocs, which are expected when
1006       // linking.
1007     case elfcpp::R_386_TLS_GD:            // Global-dynamic
1008     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
1009     case elfcpp::R_386_TLS_DESC_CALL:
1010     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
1011     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
1012     case elfcpp::R_386_TLS_IE:            // Initial-exec
1013     case elfcpp::R_386_TLS_IE_32:
1014     case elfcpp::R_386_TLS_GOTIE:
1015     case elfcpp::R_386_TLS_LE:            // Local-exec
1016     case elfcpp::R_386_TLS_LE_32:
1017       {
1018         bool output_is_shared = parameters->options().shared();
1019         const tls::Tls_optimization optimized_type
1020             = Target_i386::optimize_tls_reloc(!output_is_shared, r_type);
1021         switch (r_type)
1022           {
1023           case elfcpp::R_386_TLS_GD:          // Global-dynamic
1024             if (optimized_type == tls::TLSOPT_NONE)
1025               {
1026                 // Create a pair of GOT entries for the module index and
1027                 // dtv-relative offset.
1028                 Output_data_got<32, false>* got
1029                     = target->got_section(symtab, layout);
1030                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1031                 unsigned int shndx = lsym.get_st_shndx();
1032                 bool is_ordinary;
1033                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1034                 if (!is_ordinary)
1035                   object->error(_("local symbol %u has bad shndx %u"),
1036                               r_sym, shndx);
1037                 else
1038                   got->add_local_pair_with_rel(object, r_sym, shndx,
1039                                                GOT_TYPE_TLS_PAIR,
1040                                                target->rel_dyn_section(layout),
1041                                                elfcpp::R_386_TLS_DTPMOD32, 0);
1042               }
1043             else if (optimized_type != tls::TLSOPT_TO_LE)
1044               unsupported_reloc_local(object, r_type);
1045             break;
1046
1047           case elfcpp::R_386_TLS_GOTDESC:     // Global-dynamic (from ~oliva)
1048             target->define_tls_base_symbol(symtab, layout);
1049             if (optimized_type == tls::TLSOPT_NONE)
1050               {
1051                 // Create a double GOT entry with an R_386_TLS_DESC reloc.
1052                 Output_data_got<32, false>* got
1053                     = target->got_section(symtab, layout);
1054                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1055                 unsigned int shndx = lsym.get_st_shndx();
1056                 bool is_ordinary;
1057                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1058                 if (!is_ordinary)
1059                   object->error(_("local symbol %u has bad shndx %u"),
1060                               r_sym, shndx);
1061                 else
1062                   got->add_local_pair_with_rel(object, r_sym, shndx,
1063                                                GOT_TYPE_TLS_DESC,
1064                                                target->rel_dyn_section(layout),
1065                                                elfcpp::R_386_TLS_DESC, 0);
1066               }
1067             else if (optimized_type != tls::TLSOPT_TO_LE)
1068               unsupported_reloc_local(object, r_type);
1069             break;
1070
1071           case elfcpp::R_386_TLS_DESC_CALL:
1072             break;
1073
1074           case elfcpp::R_386_TLS_LDM:         // Local-dynamic
1075             if (optimized_type == tls::TLSOPT_NONE)
1076               {
1077                 // Create a GOT entry for the module index.
1078                 target->got_mod_index_entry(symtab, layout, object);
1079               }
1080             else if (optimized_type != tls::TLSOPT_TO_LE)
1081               unsupported_reloc_local(object, r_type);
1082             break;
1083
1084           case elfcpp::R_386_TLS_LDO_32:      // Alternate local-dynamic
1085             break;
1086
1087           case elfcpp::R_386_TLS_IE:          // Initial-exec
1088           case elfcpp::R_386_TLS_IE_32:
1089           case elfcpp::R_386_TLS_GOTIE:
1090             layout->set_has_static_tls();
1091             if (optimized_type == tls::TLSOPT_NONE)
1092               {
1093                 // For the R_386_TLS_IE relocation, we need to create a
1094                 // dynamic relocation when building a shared library.
1095                 if (r_type == elfcpp::R_386_TLS_IE
1096                     && parameters->options().shared())
1097                   {
1098                     Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1099                     unsigned int r_sym
1100                         = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1101                     rel_dyn->add_local_relative(object, r_sym,
1102                                                 elfcpp::R_386_RELATIVE,
1103                                                 output_section, data_shndx,
1104                                                 reloc.get_r_offset());
1105                   }
1106                 // Create a GOT entry for the tp-relative offset.
1107                 Output_data_got<32, false>* got
1108                     = target->got_section(symtab, layout);
1109                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1110                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
1111                                            ? elfcpp::R_386_TLS_TPOFF32
1112                                            : elfcpp::R_386_TLS_TPOFF);
1113                 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
1114                                          ? GOT_TYPE_TLS_OFFSET
1115                                          : GOT_TYPE_TLS_NOFFSET);
1116                 got->add_local_with_rel(object, r_sym, got_type,
1117                                         target->rel_dyn_section(layout),
1118                                         dyn_r_type);
1119               }
1120             else if (optimized_type != tls::TLSOPT_TO_LE)
1121               unsupported_reloc_local(object, r_type);
1122             break;
1123
1124           case elfcpp::R_386_TLS_LE:          // Local-exec
1125           case elfcpp::R_386_TLS_LE_32:
1126             layout->set_has_static_tls();
1127             if (output_is_shared)
1128               {
1129                 // We need to create a dynamic relocation.
1130                 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
1131                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1132                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
1133                                            ? elfcpp::R_386_TLS_TPOFF32
1134                                            : elfcpp::R_386_TLS_TPOFF);
1135                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1136                 rel_dyn->add_local(object, r_sym, dyn_r_type, output_section,
1137                                    data_shndx, reloc.get_r_offset());
1138               }
1139             break;
1140
1141           default:
1142             gold_unreachable();
1143           }
1144       }
1145       break;
1146
1147     case elfcpp::R_386_32PLT:
1148     case elfcpp::R_386_TLS_GD_32:
1149     case elfcpp::R_386_TLS_GD_PUSH:
1150     case elfcpp::R_386_TLS_GD_CALL:
1151     case elfcpp::R_386_TLS_GD_POP:
1152     case elfcpp::R_386_TLS_LDM_32:
1153     case elfcpp::R_386_TLS_LDM_PUSH:
1154     case elfcpp::R_386_TLS_LDM_CALL:
1155     case elfcpp::R_386_TLS_LDM_POP:
1156     case elfcpp::R_386_USED_BY_INTEL_200:
1157     default:
1158       unsupported_reloc_local(object, r_type);
1159       break;
1160     }
1161 }
1162
1163 // Report an unsupported relocation against a global symbol.
1164
1165 void
1166 Target_i386::Scan::unsupported_reloc_global(Sized_relobj<32, false>* object,
1167                                             unsigned int r_type,
1168                                             Symbol* gsym)
1169 {
1170   gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1171              object->name().c_str(), r_type, gsym->demangled_name().c_str());
1172 }
1173
1174 // Scan a relocation for a global symbol.
1175
1176 inline void
1177 Target_i386::Scan::global(Symbol_table* symtab,
1178                           Layout* layout,
1179                           Target_i386* target,
1180                           Sized_relobj<32, false>* object,
1181                           unsigned int data_shndx,
1182                           Output_section* output_section,
1183                           const elfcpp::Rel<32, false>& reloc,
1184                           unsigned int r_type,
1185                           Symbol* gsym)
1186 {
1187   switch (r_type)
1188     {
1189     case elfcpp::R_386_NONE:
1190     case elfcpp::R_386_GNU_VTINHERIT:
1191     case elfcpp::R_386_GNU_VTENTRY:
1192       break;
1193
1194     case elfcpp::R_386_32:
1195     case elfcpp::R_386_16:
1196     case elfcpp::R_386_8:
1197       {
1198         // Make a PLT entry if necessary.
1199         if (gsym->needs_plt_entry())
1200           {
1201             target->make_plt_entry(symtab, layout, gsym);
1202             // Since this is not a PC-relative relocation, we may be
1203             // taking the address of a function. In that case we need to
1204             // set the entry in the dynamic symbol table to the address of
1205             // the PLT entry.
1206             if (gsym->is_from_dynobj() && !parameters->options().shared())
1207               gsym->set_needs_dynsym_value();
1208           }
1209         // Make a dynamic relocation if necessary.
1210         if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
1211           {
1212             if (gsym->may_need_copy_reloc())
1213               {
1214                 target->copy_reloc(symtab, layout, object,
1215                                    data_shndx, output_section, gsym, reloc);
1216               }
1217             else if (r_type == elfcpp::R_386_32
1218                      && gsym->can_use_relative_reloc(false))
1219               {
1220                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1221                 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1222                                              output_section, object,
1223                                              data_shndx, reloc.get_r_offset());
1224               }
1225             else
1226               {
1227                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1228                 rel_dyn->add_global(gsym, r_type, output_section, object,
1229                                     data_shndx, reloc.get_r_offset());
1230               }
1231           }
1232       }
1233       break;
1234
1235     case elfcpp::R_386_PC32:
1236     case elfcpp::R_386_PC16:
1237     case elfcpp::R_386_PC8:
1238       {
1239         // Make a PLT entry if necessary.
1240         if (gsym->needs_plt_entry())
1241           {
1242             // These relocations are used for function calls only in
1243             // non-PIC code.  For a 32-bit relocation in a shared library,
1244             // we'll need a text relocation anyway, so we can skip the
1245             // PLT entry and let the dynamic linker bind the call directly
1246             // to the target.  For smaller relocations, we should use a
1247             // PLT entry to ensure that the call can reach.
1248             if (!parameters->options().shared()
1249                 || r_type != elfcpp::R_386_PC32)
1250               target->make_plt_entry(symtab, layout, gsym);
1251           }
1252         // Make a dynamic relocation if necessary.
1253         int flags = Symbol::NON_PIC_REF;
1254         if (gsym->is_func())
1255           flags |= Symbol::FUNCTION_CALL;
1256         if (gsym->needs_dynamic_reloc(flags))
1257           {
1258             if (gsym->may_need_copy_reloc())
1259               {
1260                 target->copy_reloc(symtab, layout, object,
1261                                    data_shndx, output_section, gsym, reloc);
1262               }
1263             else
1264               {
1265                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1266                 rel_dyn->add_global(gsym, r_type, output_section, object,
1267                                     data_shndx, reloc.get_r_offset());
1268               }
1269           }
1270       }
1271       break;
1272
1273     case elfcpp::R_386_GOT32:
1274       {
1275         // The symbol requires a GOT entry.
1276         Output_data_got<32, false>* got = target->got_section(symtab, layout);
1277         if (gsym->final_value_is_known())
1278           got->add_global(gsym, GOT_TYPE_STANDARD);
1279         else
1280           {
1281             // If this symbol is not fully resolved, we need to add a
1282             // GOT entry with a dynamic relocation.
1283             Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1284             if (gsym->is_from_dynobj()
1285                 || gsym->is_undefined()
1286                 || gsym->is_preemptible())
1287               got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
1288                                        rel_dyn, elfcpp::R_386_GLOB_DAT);
1289             else
1290               {
1291                 if (got->add_global(gsym, GOT_TYPE_STANDARD))
1292                   rel_dyn->add_global_relative(
1293                       gsym, elfcpp::R_386_RELATIVE, got,
1294                       gsym->got_offset(GOT_TYPE_STANDARD));
1295               }
1296           }
1297       }
1298       break;
1299
1300     case elfcpp::R_386_PLT32:
1301       // If the symbol is fully resolved, this is just a PC32 reloc.
1302       // Otherwise we need a PLT entry.
1303       if (gsym->final_value_is_known())
1304         break;
1305       // If building a shared library, we can also skip the PLT entry
1306       // if the symbol is defined in the output file and is protected
1307       // or hidden.
1308       if (gsym->is_defined()
1309           && !gsym->is_from_dynobj()
1310           && !gsym->is_preemptible())
1311         break;
1312       target->make_plt_entry(symtab, layout, gsym);
1313       break;
1314
1315     case elfcpp::R_386_GOTOFF:
1316     case elfcpp::R_386_GOTPC:
1317       // We need a GOT section.
1318       target->got_section(symtab, layout);
1319       break;
1320
1321       // These are relocations which should only be seen by the
1322       // dynamic linker, and should never be seen here.
1323     case elfcpp::R_386_COPY:
1324     case elfcpp::R_386_GLOB_DAT:
1325     case elfcpp::R_386_JUMP_SLOT:
1326     case elfcpp::R_386_RELATIVE:
1327     case elfcpp::R_386_TLS_TPOFF:
1328     case elfcpp::R_386_TLS_DTPMOD32:
1329     case elfcpp::R_386_TLS_DTPOFF32:
1330     case elfcpp::R_386_TLS_TPOFF32:
1331     case elfcpp::R_386_TLS_DESC:
1332       gold_error(_("%s: unexpected reloc %u in object file"),
1333                  object->name().c_str(), r_type);
1334       break;
1335
1336       // These are initial tls relocs, which are expected when
1337       // linking.
1338     case elfcpp::R_386_TLS_GD:            // Global-dynamic
1339     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
1340     case elfcpp::R_386_TLS_DESC_CALL:
1341     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
1342     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
1343     case elfcpp::R_386_TLS_IE:            // Initial-exec
1344     case elfcpp::R_386_TLS_IE_32:
1345     case elfcpp::R_386_TLS_GOTIE:
1346     case elfcpp::R_386_TLS_LE:            // Local-exec
1347     case elfcpp::R_386_TLS_LE_32:
1348       {
1349         const bool is_final = gsym->final_value_is_known();
1350         const tls::Tls_optimization optimized_type
1351             = Target_i386::optimize_tls_reloc(is_final, r_type);
1352         switch (r_type)
1353           {
1354           case elfcpp::R_386_TLS_GD:          // Global-dynamic
1355             if (optimized_type == tls::TLSOPT_NONE)
1356               {
1357                 // Create a pair of GOT entries for the module index and
1358                 // dtv-relative offset.
1359                 Output_data_got<32, false>* got
1360                     = target->got_section(symtab, layout);
1361                 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
1362                                              target->rel_dyn_section(layout),
1363                                              elfcpp::R_386_TLS_DTPMOD32,
1364                                              elfcpp::R_386_TLS_DTPOFF32);
1365               }
1366             else if (optimized_type == tls::TLSOPT_TO_IE)
1367               {
1368                 // Create a GOT entry for the tp-relative offset.
1369                 Output_data_got<32, false>* got
1370                     = target->got_section(symtab, layout);
1371                 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
1372                                          target->rel_dyn_section(layout),
1373                                          elfcpp::R_386_TLS_TPOFF);
1374               }
1375             else if (optimized_type != tls::TLSOPT_TO_LE)
1376               unsupported_reloc_global(object, r_type, gsym);
1377             break;
1378
1379           case elfcpp::R_386_TLS_GOTDESC:     // Global-dynamic (~oliva url)
1380             target->define_tls_base_symbol(symtab, layout);
1381             if (optimized_type == tls::TLSOPT_NONE)
1382               {
1383                 // Create a double GOT entry with an R_386_TLS_DESC reloc.
1384                 Output_data_got<32, false>* got
1385                     = target->got_section(symtab, layout);
1386                 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC,
1387                                              target->rel_dyn_section(layout),
1388                                              elfcpp::R_386_TLS_DESC, 0);
1389               }
1390             else if (optimized_type == tls::TLSOPT_TO_IE)
1391               {
1392                 // Create a GOT entry for the tp-relative offset.
1393                 Output_data_got<32, false>* got
1394                     = target->got_section(symtab, layout);
1395                 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
1396                                          target->rel_dyn_section(layout),
1397                                          elfcpp::R_386_TLS_TPOFF);
1398               }
1399             else if (optimized_type != tls::TLSOPT_TO_LE)
1400               unsupported_reloc_global(object, r_type, gsym);
1401             break;
1402
1403           case elfcpp::R_386_TLS_DESC_CALL:
1404             break;
1405
1406           case elfcpp::R_386_TLS_LDM:         // Local-dynamic
1407             if (optimized_type == tls::TLSOPT_NONE)
1408               {
1409                 // Create a GOT entry for the module index.
1410                 target->got_mod_index_entry(symtab, layout, object);
1411               }
1412             else if (optimized_type != tls::TLSOPT_TO_LE)
1413               unsupported_reloc_global(object, r_type, gsym);
1414             break;
1415
1416           case elfcpp::R_386_TLS_LDO_32:      // Alternate local-dynamic
1417             break;
1418
1419           case elfcpp::R_386_TLS_IE:          // Initial-exec
1420           case elfcpp::R_386_TLS_IE_32:
1421           case elfcpp::R_386_TLS_GOTIE:
1422             layout->set_has_static_tls();
1423             if (optimized_type == tls::TLSOPT_NONE)
1424               {
1425                 // For the R_386_TLS_IE relocation, we need to create a
1426                 // dynamic relocation when building a shared library.
1427                 if (r_type == elfcpp::R_386_TLS_IE
1428                     && parameters->options().shared())
1429                   {
1430                     Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1431                     rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1432                                                  output_section, object,
1433                                                  data_shndx,
1434                                                  reloc.get_r_offset());
1435                   }
1436                 // Create a GOT entry for the tp-relative offset.
1437                 Output_data_got<32, false>* got
1438                     = target->got_section(symtab, layout);
1439                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
1440                                            ? elfcpp::R_386_TLS_TPOFF32
1441                                            : elfcpp::R_386_TLS_TPOFF);
1442                 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
1443                                          ? GOT_TYPE_TLS_OFFSET
1444                                          : GOT_TYPE_TLS_NOFFSET);
1445                 got->add_global_with_rel(gsym, got_type,
1446                                          target->rel_dyn_section(layout),
1447                                          dyn_r_type);
1448               }
1449             else if (optimized_type != tls::TLSOPT_TO_LE)
1450               unsupported_reloc_global(object, r_type, gsym);
1451             break;
1452
1453           case elfcpp::R_386_TLS_LE:          // Local-exec
1454           case elfcpp::R_386_TLS_LE_32:
1455             layout->set_has_static_tls();
1456             if (parameters->options().shared())
1457               {
1458                 // We need to create a dynamic relocation.
1459                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
1460                                            ? elfcpp::R_386_TLS_TPOFF32
1461                                            : elfcpp::R_386_TLS_TPOFF);
1462                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1463                 rel_dyn->add_global(gsym, dyn_r_type, output_section, object,
1464                                     data_shndx, reloc.get_r_offset());
1465               }
1466             break;
1467
1468           default:
1469             gold_unreachable();
1470           }
1471       }
1472       break;
1473
1474     case elfcpp::R_386_32PLT:
1475     case elfcpp::R_386_TLS_GD_32:
1476     case elfcpp::R_386_TLS_GD_PUSH:
1477     case elfcpp::R_386_TLS_GD_CALL:
1478     case elfcpp::R_386_TLS_GD_POP:
1479     case elfcpp::R_386_TLS_LDM_32:
1480     case elfcpp::R_386_TLS_LDM_PUSH:
1481     case elfcpp::R_386_TLS_LDM_CALL:
1482     case elfcpp::R_386_TLS_LDM_POP:
1483     case elfcpp::R_386_USED_BY_INTEL_200:
1484     default:
1485       unsupported_reloc_global(object, r_type, gsym);
1486       break;
1487     }
1488 }
1489
1490 // Process relocations for gc.
1491
1492 void
1493 Target_i386::gc_process_relocs(Symbol_table* symtab,
1494                                Layout* layout,
1495                                Sized_relobj<32, false>* object,
1496                                unsigned int data_shndx,
1497                                unsigned int,
1498                                const unsigned char* prelocs,
1499                                size_t reloc_count,
1500                                Output_section* output_section,
1501                                bool needs_special_offset_handling,
1502                                size_t local_symbol_count,
1503                                const unsigned char* plocal_symbols)
1504 {
1505   gold::gc_process_relocs<32, false, Target_i386, elfcpp::SHT_REL,
1506                           Target_i386::Scan>(
1507     symtab,
1508     layout,
1509     this,
1510     object,
1511     data_shndx,
1512     prelocs,
1513     reloc_count,
1514     output_section,
1515     needs_special_offset_handling,
1516     local_symbol_count,
1517     plocal_symbols);
1518 }
1519
1520 // Scan relocations for a section.
1521
1522 void
1523 Target_i386::scan_relocs(Symbol_table* symtab,
1524                          Layout* layout,
1525                          Sized_relobj<32, false>* object,
1526                          unsigned int data_shndx,
1527                          unsigned int sh_type,
1528                          const unsigned char* prelocs,
1529                          size_t reloc_count,
1530                          Output_section* output_section,
1531                          bool needs_special_offset_handling,
1532                          size_t local_symbol_count,
1533                          const unsigned char* plocal_symbols)
1534 {
1535   if (sh_type == elfcpp::SHT_RELA)
1536     {
1537       gold_error(_("%s: unsupported RELA reloc section"),
1538                  object->name().c_str());
1539       return;
1540     }
1541
1542   gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL,
1543                     Target_i386::Scan>(
1544     symtab,
1545     layout,
1546     this,
1547     object,
1548     data_shndx,
1549     prelocs,
1550     reloc_count,
1551     output_section,
1552     needs_special_offset_handling,
1553     local_symbol_count,
1554     plocal_symbols);
1555 }
1556
1557 // Finalize the sections.
1558
1559 void
1560 Target_i386::do_finalize_sections(
1561     Layout* layout,
1562     const Input_objects*,
1563     Symbol_table*)
1564 {
1565   // Fill in some more dynamic tags.
1566   Output_data_dynamic* const odyn = layout->dynamic_data();
1567   if (odyn != NULL)
1568     {
1569       if (this->got_plt_ != NULL
1570           && this->got_plt_->output_section() != NULL)
1571         odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_);
1572
1573       if (this->plt_ != NULL
1574           && this->plt_->output_section() != NULL)
1575         {
1576           const Output_data* od = this->plt_->rel_plt();
1577           odyn->add_section_size(elfcpp::DT_PLTRELSZ, od);
1578           odyn->add_section_address(elfcpp::DT_JMPREL, od);
1579           odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_REL);
1580         }
1581
1582       if (this->rel_dyn_ != NULL
1583           && this->rel_dyn_->output_section() != NULL)
1584         {
1585           const Output_data* od = this->rel_dyn_;
1586           odyn->add_section_address(elfcpp::DT_REL, od);
1587           odyn->add_section_size(elfcpp::DT_RELSZ, od);
1588           odyn->add_constant(elfcpp::DT_RELENT,
1589                              elfcpp::Elf_sizes<32>::rel_size);
1590         }
1591
1592       if (!parameters->options().shared())
1593         {
1594           // The value of the DT_DEBUG tag is filled in by the dynamic
1595           // linker at run time, and used by the debugger.
1596           odyn->add_constant(elfcpp::DT_DEBUG, 0);
1597         }
1598     }
1599
1600   // Emit any relocs we saved in an attempt to avoid generating COPY
1601   // relocs.
1602   if (this->copy_relocs_.any_saved_relocs())
1603     this->copy_relocs_.emit(this->rel_dyn_section(layout));
1604 }
1605
1606 // Return whether a direct absolute static relocation needs to be applied.
1607 // In cases where Scan::local() or Scan::global() has created
1608 // a dynamic relocation other than R_386_RELATIVE, the addend
1609 // of the relocation is carried in the data, and we must not
1610 // apply the static relocation.
1611
1612 inline bool
1613 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol<32>* gsym,
1614                                                  int ref_flags,
1615                                                  bool is_32bit,
1616                                                  Output_section* output_section)
1617 {
1618   // If the output section is not allocated, then we didn't call
1619   // scan_relocs, we didn't create a dynamic reloc, and we must apply
1620   // the reloc here.
1621   if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
1622     return true;
1623
1624   // For local symbols, we will have created a non-RELATIVE dynamic
1625   // relocation only if (a) the output is position independent,
1626   // (b) the relocation is absolute (not pc- or segment-relative), and
1627   // (c) the relocation is not 32 bits wide.
1628   if (gsym == NULL)
1629     return !(parameters->options().output_is_position_independent()
1630              && (ref_flags & Symbol::ABSOLUTE_REF)
1631              && !is_32bit);
1632
1633   // For global symbols, we use the same helper routines used in the
1634   // scan pass.  If we did not create a dynamic relocation, or if we
1635   // created a RELATIVE dynamic relocation, we should apply the static
1636   // relocation.
1637   bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
1638   bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
1639                 && gsym->can_use_relative_reloc(ref_flags
1640                                                 & Symbol::FUNCTION_CALL);
1641   return !has_dyn || is_rel;
1642 }
1643
1644 // Perform a relocation.
1645
1646 inline bool
1647 Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
1648                                 Target_i386* target,
1649                                 Output_section *output_section,
1650                                 size_t relnum,
1651                                 const elfcpp::Rel<32, false>& rel,
1652                                 unsigned int r_type,
1653                                 const Sized_symbol<32>* gsym,
1654                                 const Symbol_value<32>* psymval,
1655                                 unsigned char* view,
1656                                 elfcpp::Elf_types<32>::Elf_Addr address,
1657                                 section_size_type view_size)
1658 {
1659   if (this->skip_call_tls_get_addr_)
1660     {
1661       if ((r_type != elfcpp::R_386_PLT32
1662            && r_type != elfcpp::R_386_PC32)
1663           || gsym == NULL
1664           || strcmp(gsym->name(), "___tls_get_addr") != 0)
1665         gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1666                                _("missing expected TLS relocation"));
1667       else
1668         {
1669           this->skip_call_tls_get_addr_ = false;
1670           return false;
1671         }
1672     }
1673
1674   // Pick the value to use for symbols defined in shared objects.
1675   Symbol_value<32> symval;
1676   if (gsym != NULL
1677       && gsym->use_plt_offset(r_type == elfcpp::R_386_PC8
1678                               || r_type == elfcpp::R_386_PC16
1679                               || r_type == elfcpp::R_386_PC32))
1680     {
1681       symval.set_output_value(target->plt_section()->address()
1682                               + gsym->plt_offset());
1683       psymval = &symval;
1684     }
1685
1686   const Sized_relobj<32, false>* object = relinfo->object;
1687
1688   // Get the GOT offset if needed.
1689   // The GOT pointer points to the end of the GOT section.
1690   // We need to subtract the size of the GOT section to get
1691   // the actual offset to use in the relocation.
1692   bool have_got_offset = false;
1693   unsigned int got_offset = 0;
1694   switch (r_type)
1695     {
1696     case elfcpp::R_386_GOT32:
1697       if (gsym != NULL)
1698         {
1699           gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
1700           got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
1701                         - target->got_size());
1702         }
1703       else
1704         {
1705           unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
1706           gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
1707           got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
1708                         - target->got_size());
1709         }
1710       have_got_offset = true;
1711       break;
1712
1713     default:
1714       break;
1715     }
1716
1717   switch (r_type)
1718     {
1719     case elfcpp::R_386_NONE:
1720     case elfcpp::R_386_GNU_VTINHERIT:
1721     case elfcpp::R_386_GNU_VTENTRY:
1722       break;
1723
1724     case elfcpp::R_386_32:
1725       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
1726                                     output_section))
1727         Relocate_functions<32, false>::rel32(view, object, psymval);
1728       break;
1729
1730     case elfcpp::R_386_PC32:
1731       {
1732         int ref_flags = Symbol::NON_PIC_REF;
1733         if (gsym != NULL && gsym->is_func())
1734           ref_flags |= Symbol::FUNCTION_CALL;
1735         if (should_apply_static_reloc(gsym, ref_flags, true, output_section))
1736           Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1737       }
1738       break;
1739
1740     case elfcpp::R_386_16:
1741       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
1742                                     output_section))
1743         Relocate_functions<32, false>::rel16(view, object, psymval);
1744       break;
1745
1746     case elfcpp::R_386_PC16:
1747       {
1748         int ref_flags = Symbol::NON_PIC_REF;
1749         if (gsym != NULL && gsym->is_func())
1750           ref_flags |= Symbol::FUNCTION_CALL;
1751         if (should_apply_static_reloc(gsym, ref_flags, false, output_section))
1752           Relocate_functions<32, false>::pcrel16(view, object, psymval, address);
1753       }
1754       break;
1755
1756     case elfcpp::R_386_8:
1757       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
1758                                     output_section))
1759         Relocate_functions<32, false>::rel8(view, object, psymval);
1760       break;
1761
1762     case elfcpp::R_386_PC8:
1763       {
1764         int ref_flags = Symbol::NON_PIC_REF;
1765         if (gsym != NULL && gsym->is_func())
1766           ref_flags |= Symbol::FUNCTION_CALL;
1767         if (should_apply_static_reloc(gsym, ref_flags, false,
1768                                       output_section))
1769           Relocate_functions<32, false>::pcrel8(view, object, psymval, address);
1770       }
1771       break;
1772
1773     case elfcpp::R_386_PLT32:
1774       gold_assert(gsym == NULL
1775                   || gsym->has_plt_offset()
1776                   || gsym->final_value_is_known()
1777                   || (gsym->is_defined()
1778                       && !gsym->is_from_dynobj()
1779                       && !gsym->is_preemptible()));
1780       Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1781       break;
1782
1783     case elfcpp::R_386_GOT32:
1784       gold_assert(have_got_offset);
1785       Relocate_functions<32, false>::rel32(view, got_offset);
1786       break;
1787
1788     case elfcpp::R_386_GOTOFF:
1789       {
1790         elfcpp::Elf_types<32>::Elf_Addr value;
1791         value = (psymval->value(object, 0)
1792                  - target->got_plt_section()->address());
1793         Relocate_functions<32, false>::rel32(view, value);
1794       }
1795       break;
1796
1797     case elfcpp::R_386_GOTPC:
1798       {
1799         elfcpp::Elf_types<32>::Elf_Addr value;
1800         value = target->got_plt_section()->address();
1801         Relocate_functions<32, false>::pcrel32(view, value, address);
1802       }
1803       break;
1804
1805     case elfcpp::R_386_COPY:
1806     case elfcpp::R_386_GLOB_DAT:
1807     case elfcpp::R_386_JUMP_SLOT:
1808     case elfcpp::R_386_RELATIVE:
1809       // These are outstanding tls relocs, which are unexpected when
1810       // linking.
1811     case elfcpp::R_386_TLS_TPOFF:
1812     case elfcpp::R_386_TLS_DTPMOD32:
1813     case elfcpp::R_386_TLS_DTPOFF32:
1814     case elfcpp::R_386_TLS_TPOFF32:
1815     case elfcpp::R_386_TLS_DESC:
1816       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1817                              _("unexpected reloc %u in object file"),
1818                              r_type);
1819       break;
1820
1821       // These are initial tls relocs, which are expected when
1822       // linking.
1823     case elfcpp::R_386_TLS_GD:             // Global-dynamic
1824     case elfcpp::R_386_TLS_GOTDESC:        // Global-dynamic (from ~oliva url)
1825     case elfcpp::R_386_TLS_DESC_CALL:
1826     case elfcpp::R_386_TLS_LDM:            // Local-dynamic
1827     case elfcpp::R_386_TLS_LDO_32:         // Alternate local-dynamic
1828     case elfcpp::R_386_TLS_IE:             // Initial-exec
1829     case elfcpp::R_386_TLS_IE_32:
1830     case elfcpp::R_386_TLS_GOTIE:
1831     case elfcpp::R_386_TLS_LE:             // Local-exec
1832     case elfcpp::R_386_TLS_LE_32:
1833       this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
1834                          view, address, view_size);
1835       break;
1836
1837     case elfcpp::R_386_32PLT:
1838     case elfcpp::R_386_TLS_GD_32:
1839     case elfcpp::R_386_TLS_GD_PUSH:
1840     case elfcpp::R_386_TLS_GD_CALL:
1841     case elfcpp::R_386_TLS_GD_POP:
1842     case elfcpp::R_386_TLS_LDM_32:
1843     case elfcpp::R_386_TLS_LDM_PUSH:
1844     case elfcpp::R_386_TLS_LDM_CALL:
1845     case elfcpp::R_386_TLS_LDM_POP:
1846     case elfcpp::R_386_USED_BY_INTEL_200:
1847     default:
1848       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1849                              _("unsupported reloc %u"),
1850                              r_type);
1851       break;
1852     }
1853
1854   return true;
1855 }
1856
1857 // Perform a TLS relocation.
1858
1859 inline void
1860 Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo,
1861                                     Target_i386* target,
1862                                     size_t relnum,
1863                                     const elfcpp::Rel<32, false>& rel,
1864                                     unsigned int r_type,
1865                                     const Sized_symbol<32>* gsym,
1866                                     const Symbol_value<32>* psymval,
1867                                     unsigned char* view,
1868                                     elfcpp::Elf_types<32>::Elf_Addr,
1869                                     section_size_type view_size)
1870 {
1871   Output_segment* tls_segment = relinfo->layout->tls_segment();
1872
1873   const Sized_relobj<32, false>* object = relinfo->object;
1874
1875   elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
1876
1877   const bool is_final =
1878     (gsym == NULL
1879      ? !parameters->options().output_is_position_independent()
1880      : gsym->final_value_is_known());
1881   const tls::Tls_optimization optimized_type
1882       = Target_i386::optimize_tls_reloc(is_final, r_type);
1883   switch (r_type)
1884     {
1885     case elfcpp::R_386_TLS_GD:           // Global-dynamic
1886       if (optimized_type == tls::TLSOPT_TO_LE)
1887         {
1888           gold_assert(tls_segment != NULL);
1889           this->tls_gd_to_le(relinfo, relnum, tls_segment,
1890                              rel, r_type, value, view,
1891                              view_size);
1892           break;
1893         }
1894       else
1895         {
1896           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
1897                                    ? GOT_TYPE_TLS_NOFFSET
1898                                    : GOT_TYPE_TLS_PAIR);
1899           unsigned int got_offset;
1900           if (gsym != NULL)
1901             {
1902               gold_assert(gsym->has_got_offset(got_type));
1903               got_offset = gsym->got_offset(got_type) - target->got_size();
1904             }
1905           else
1906             {
1907               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
1908               gold_assert(object->local_has_got_offset(r_sym, got_type));
1909               got_offset = (object->local_got_offset(r_sym, got_type)
1910                             - target->got_size());
1911             }
1912           if (optimized_type == tls::TLSOPT_TO_IE)
1913             {
1914               gold_assert(tls_segment != NULL);
1915               this->tls_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
1916                                  got_offset, view, view_size);
1917               break;
1918             }
1919           else if (optimized_type == tls::TLSOPT_NONE)
1920             {
1921               // Relocate the field with the offset of the pair of GOT
1922               // entries.
1923               Relocate_functions<32, false>::rel32(view, got_offset);
1924               break;
1925             }
1926         }
1927       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1928                              _("unsupported reloc %u"),
1929                              r_type);
1930       break;
1931
1932     case elfcpp::R_386_TLS_GOTDESC:      // Global-dynamic (from ~oliva url)
1933     case elfcpp::R_386_TLS_DESC_CALL:
1934       this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
1935       if (optimized_type == tls::TLSOPT_TO_LE)
1936         {
1937           gold_assert(tls_segment != NULL);
1938           this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
1939                                   rel, r_type, value, view,
1940                                   view_size);
1941           break;
1942         }
1943       else
1944         {
1945           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
1946                                    ? GOT_TYPE_TLS_NOFFSET
1947                                    : GOT_TYPE_TLS_DESC);
1948           unsigned int got_offset;
1949           if (gsym != NULL)
1950             {
1951               gold_assert(gsym->has_got_offset(got_type));
1952               got_offset = gsym->got_offset(got_type) - target->got_size();
1953             }
1954           else
1955             {
1956               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
1957               gold_assert(object->local_has_got_offset(r_sym, got_type));
1958               got_offset = (object->local_got_offset(r_sym, got_type)
1959                             - target->got_size());
1960             }
1961           if (optimized_type == tls::TLSOPT_TO_IE)
1962             {
1963               gold_assert(tls_segment != NULL);
1964               this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
1965                                       got_offset, view, view_size);
1966               break;
1967             }
1968           else if (optimized_type == tls::TLSOPT_NONE)
1969             {
1970               if (r_type == elfcpp::R_386_TLS_GOTDESC)
1971                 {
1972                   // Relocate the field with the offset of the pair of GOT
1973                   // entries.
1974                   Relocate_functions<32, false>::rel32(view, got_offset);
1975                 }
1976               break;
1977             }
1978         }
1979       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1980                              _("unsupported reloc %u"),
1981                              r_type);
1982       break;
1983
1984     case elfcpp::R_386_TLS_LDM:          // Local-dynamic
1985       if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN)
1986         {
1987           gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1988                                  _("both SUN and GNU model "
1989                                    "TLS relocations"));
1990           break;
1991         }
1992       this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
1993       if (optimized_type == tls::TLSOPT_TO_LE)
1994         {
1995           gold_assert(tls_segment != NULL);
1996           this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, r_type,
1997                              value, view, view_size);
1998           break;
1999         }
2000       else if (optimized_type == tls::TLSOPT_NONE)
2001         {
2002           // Relocate the field with the offset of the GOT entry for
2003           // the module index.
2004           unsigned int got_offset;
2005           got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
2006                         - target->got_size());
2007           Relocate_functions<32, false>::rel32(view, got_offset);
2008           break;
2009         }
2010       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2011                              _("unsupported reloc %u"),
2012                              r_type);
2013       break;
2014
2015     case elfcpp::R_386_TLS_LDO_32:       // Alternate local-dynamic
2016       if (optimized_type == tls::TLSOPT_TO_LE)
2017         {
2018           // This reloc can appear in debugging sections, in which
2019           // case we must not convert to local-exec.  We decide what
2020           // to do based on whether the section is marked as
2021           // containing executable code.  That is what the GNU linker
2022           // does as well.
2023           elfcpp::Shdr<32, false> shdr(relinfo->data_shdr);
2024           if ((shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0)
2025             {
2026               gold_assert(tls_segment != NULL);
2027               value -= tls_segment->memsz();
2028             }
2029         }
2030       Relocate_functions<32, false>::rel32(view, value);
2031       break;
2032
2033     case elfcpp::R_386_TLS_IE:           // Initial-exec
2034     case elfcpp::R_386_TLS_GOTIE:
2035     case elfcpp::R_386_TLS_IE_32:
2036       if (optimized_type == tls::TLSOPT_TO_LE)
2037         {
2038           gold_assert(tls_segment != NULL);
2039           Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
2040                                               rel, r_type, value, view,
2041                                               view_size);
2042           break;
2043         }
2044       else if (optimized_type == tls::TLSOPT_NONE)
2045         {
2046           // Relocate the field with the offset of the GOT entry for
2047           // the tp-relative offset of the symbol.
2048           unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
2049                                    ? GOT_TYPE_TLS_OFFSET
2050                                    : GOT_TYPE_TLS_NOFFSET);
2051           unsigned int got_offset;
2052           if (gsym != NULL)
2053             {
2054               gold_assert(gsym->has_got_offset(got_type));
2055               got_offset = gsym->got_offset(got_type);
2056             }
2057           else
2058             {
2059               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2060               gold_assert(object->local_has_got_offset(r_sym, got_type));
2061               got_offset = object->local_got_offset(r_sym, got_type);
2062             }
2063           // For the R_386_TLS_IE relocation, we need to apply the
2064           // absolute address of the GOT entry.
2065           if (r_type == elfcpp::R_386_TLS_IE)
2066             got_offset += target->got_plt_section()->address();
2067           // All GOT offsets are relative to the end of the GOT.
2068           got_offset -= target->got_size();
2069           Relocate_functions<32, false>::rel32(view, got_offset);
2070           break;
2071         }
2072       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2073                              _("unsupported reloc %u"),
2074                              r_type);
2075       break;
2076
2077     case elfcpp::R_386_TLS_LE:           // Local-exec
2078       // If we're creating a shared library, a dynamic relocation will
2079       // have been created for this location, so do not apply it now.
2080       if (!parameters->options().shared())
2081         {
2082           gold_assert(tls_segment != NULL);
2083           value -= tls_segment->memsz();
2084           Relocate_functions<32, false>::rel32(view, value);
2085         }
2086       break;
2087
2088     case elfcpp::R_386_TLS_LE_32:
2089       // If we're creating a shared library, a dynamic relocation will
2090       // have been created for this location, so do not apply it now.
2091       if (!parameters->options().shared())
2092         {
2093           gold_assert(tls_segment != NULL);
2094           value = tls_segment->memsz() - value;
2095           Relocate_functions<32, false>::rel32(view, value);
2096         }
2097       break;
2098     }
2099 }
2100
2101 // Do a relocation in which we convert a TLS General-Dynamic to a
2102 // Local-Exec.
2103
2104 inline void
2105 Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo,
2106                                     size_t relnum,
2107                                     Output_segment* tls_segment,
2108                                     const elfcpp::Rel<32, false>& rel,
2109                                     unsigned int,
2110                                     elfcpp::Elf_types<32>::Elf_Addr value,
2111                                     unsigned char* view,
2112                                     section_size_type view_size)
2113 {
2114   // leal foo(,%reg,1),%eax; call ___tls_get_addr
2115   //  ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2116   // leal foo(%reg),%eax; call ___tls_get_addr
2117   //  ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2118
2119   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2120   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2121
2122   unsigned char op1 = view[-1];
2123   unsigned char op2 = view[-2];
2124
2125   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2126                  op2 == 0x8d || op2 == 0x04);
2127   tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2128
2129   int roff = 5;
2130
2131   if (op2 == 0x04)
2132     {
2133       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
2134       tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
2135       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2136                      ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
2137       memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2138     }
2139   else
2140     {
2141       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2142                      (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
2143       if (rel.get_r_offset() + 9 < view_size
2144           && view[9] == 0x90)
2145         {
2146           // There is a trailing nop.  Use the size byte subl.
2147           memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2148           roff = 6;
2149         }
2150       else
2151         {
2152           // Use the five byte subl.
2153           memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2154         }
2155     }
2156
2157   value = tls_segment->memsz() - value;
2158   Relocate_functions<32, false>::rel32(view + roff, value);
2159
2160   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2161   // We can skip it.
2162   this->skip_call_tls_get_addr_ = true;
2163 }
2164
2165 // Do a relocation in which we convert a TLS General-Dynamic to an
2166 // Initial-Exec.
2167
2168 inline void
2169 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info<32, false>* relinfo,
2170                                     size_t relnum,
2171                                     Output_segment*,
2172                                     const elfcpp::Rel<32, false>& rel,
2173                                     unsigned int,
2174                                     elfcpp::Elf_types<32>::Elf_Addr value,
2175                                     unsigned char* view,
2176                                     section_size_type view_size)
2177 {
2178   // leal foo(,%ebx,1),%eax; call ___tls_get_addr
2179   //  ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
2180
2181   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2182   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2183
2184   unsigned char op1 = view[-1];
2185   unsigned char op2 = view[-2];
2186
2187   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2188                  op2 == 0x8d || op2 == 0x04);
2189   tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2190
2191   int roff = 5;
2192
2193   // FIXME: For now, support only the first (SIB) form.
2194   tls::check_tls(relinfo, relnum, rel.get_r_offset(), op2 == 0x04);
2195
2196   if (op2 == 0x04)
2197     {
2198       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
2199       tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
2200       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2201                      ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
2202       memcpy(view - 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
2203     }
2204   else
2205     {
2206       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2207                      (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
2208       if (rel.get_r_offset() + 9 < view_size
2209           && view[9] == 0x90)
2210         {
2211           // FIXME: This is not the right instruction sequence.
2212           // There is a trailing nop.  Use the size byte subl.
2213           memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2214           roff = 6;
2215         }
2216       else
2217         {
2218           // FIXME: This is not the right instruction sequence.
2219           // Use the five byte subl.
2220           memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2221         }
2222     }
2223
2224   Relocate_functions<32, false>::rel32(view + roff, value);
2225
2226   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2227   // We can skip it.
2228   this->skip_call_tls_get_addr_ = true;
2229 }
2230
2231 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2232 // General-Dynamic to a Local-Exec.
2233
2234 inline void
2235 Target_i386::Relocate::tls_desc_gd_to_le(
2236     const Relocate_info<32, false>* relinfo,
2237     size_t relnum,
2238     Output_segment* tls_segment,
2239     const elfcpp::Rel<32, false>& rel,
2240     unsigned int r_type,
2241     elfcpp::Elf_types<32>::Elf_Addr value,
2242     unsigned char* view,
2243     section_size_type view_size)
2244 {
2245   if (r_type == elfcpp::R_386_TLS_GOTDESC)
2246     {
2247       // leal foo@TLSDESC(%ebx), %eax
2248       // ==> leal foo@NTPOFF, %eax
2249       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2250       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2251       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2252                      view[-2] == 0x8d && view[-1] == 0x83);
2253       view[-1] = 0x05;
2254       value -= tls_segment->memsz();
2255       Relocate_functions<32, false>::rel32(view, value);
2256     }
2257   else
2258     {
2259       // call *foo@TLSCALL(%eax)
2260       // ==> nop; nop
2261       gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
2262       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
2263       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2264                      view[0] == 0xff && view[1] == 0x10);
2265       view[0] = 0x66;
2266       view[1] = 0x90;
2267     }
2268 }
2269
2270 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2271 // General-Dynamic to an Initial-Exec.
2272
2273 inline void
2274 Target_i386::Relocate::tls_desc_gd_to_ie(
2275     const Relocate_info<32, false>* relinfo,
2276     size_t relnum,
2277     Output_segment*,
2278     const elfcpp::Rel<32, false>& rel,
2279     unsigned int r_type,
2280     elfcpp::Elf_types<32>::Elf_Addr value,
2281     unsigned char* view,
2282     section_size_type view_size)
2283 {
2284   if (r_type == elfcpp::R_386_TLS_GOTDESC)
2285     {
2286       // leal foo@TLSDESC(%ebx), %eax
2287       // ==> movl foo@GOTNTPOFF(%ebx), %eax
2288       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2289       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2290       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2291                      view[-2] == 0x8d && view[-1] == 0x83);
2292       view[-2] = 0x8b;
2293       Relocate_functions<32, false>::rel32(view, value);
2294     }
2295   else
2296     {
2297       // call *foo@TLSCALL(%eax)
2298       // ==> nop; nop
2299       gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
2300       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
2301       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2302                      view[0] == 0xff && view[1] == 0x10);
2303       view[0] = 0x66;
2304       view[1] = 0x90;
2305     }
2306 }
2307
2308 // Do a relocation in which we convert a TLS Local-Dynamic to a
2309 // Local-Exec.
2310
2311 inline void
2312 Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo,
2313                                     size_t relnum,
2314                                     Output_segment*,
2315                                     const elfcpp::Rel<32, false>& rel,
2316                                     unsigned int,
2317                                     elfcpp::Elf_types<32>::Elf_Addr,
2318                                     unsigned char* view,
2319                                     section_size_type view_size)
2320 {
2321   // leal foo(%reg), %eax; call ___tls_get_addr
2322   // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
2323
2324   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2325   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2326
2327   // FIXME: Does this test really always pass?
2328   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2329                  view[-2] == 0x8d && view[-1] == 0x83);
2330
2331   tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2332
2333   memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
2334
2335   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2336   // We can skip it.
2337   this->skip_call_tls_get_addr_ = true;
2338 }
2339
2340 // Do a relocation in which we convert a TLS Initial-Exec to a
2341 // Local-Exec.
2342
2343 inline void
2344 Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo,
2345                                     size_t relnum,
2346                                     Output_segment* tls_segment,
2347                                     const elfcpp::Rel<32, false>& rel,
2348                                     unsigned int r_type,
2349                                     elfcpp::Elf_types<32>::Elf_Addr value,
2350                                     unsigned char* view,
2351                                     section_size_type view_size)
2352 {
2353   // We have to actually change the instructions, which means that we
2354   // need to examine the opcodes to figure out which instruction we
2355   // are looking at.
2356   if (r_type == elfcpp::R_386_TLS_IE)
2357     {
2358       // movl %gs:XX,%eax  ==>  movl $YY,%eax
2359       // movl %gs:XX,%reg  ==>  movl $YY,%reg
2360       // addl %gs:XX,%reg  ==>  addl $YY,%reg
2361       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -1);
2362       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2363
2364       unsigned char op1 = view[-1];
2365       if (op1 == 0xa1)
2366         {
2367           // movl XX,%eax  ==>  movl $YY,%eax
2368           view[-1] = 0xb8;
2369         }
2370       else
2371         {
2372           tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2373
2374           unsigned char op2 = view[-2];
2375           if (op2 == 0x8b)
2376             {
2377               // movl XX,%reg  ==>  movl $YY,%reg
2378               tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2379                              (op1 & 0xc7) == 0x05);
2380               view[-2] = 0xc7;
2381               view[-1] = 0xc0 | ((op1 >> 3) & 7);
2382             }
2383           else if (op2 == 0x03)
2384             {
2385               // addl XX,%reg  ==>  addl $YY,%reg
2386               tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2387                              (op1 & 0xc7) == 0x05);
2388               view[-2] = 0x81;
2389               view[-1] = 0xc0 | ((op1 >> 3) & 7);
2390             }
2391           else
2392             tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
2393         }
2394     }
2395   else
2396     {
2397       // subl %gs:XX(%reg1),%reg2  ==>  subl $YY,%reg2
2398       // movl %gs:XX(%reg1),%reg2  ==>  movl $YY,%reg2
2399       // addl %gs:XX(%reg1),%reg2  ==>  addl $YY,$reg2
2400       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2401       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2402
2403       unsigned char op1 = view[-1];
2404       unsigned char op2 = view[-2];
2405       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2406                      (op1 & 0xc0) == 0x80 && (op1 & 7) != 4);
2407       if (op2 == 0x8b)
2408         {
2409           // movl %gs:XX(%reg1),%reg2  ==>  movl $YY,%reg2
2410           view[-2] = 0xc7;
2411           view[-1] = 0xc0 | ((op1 >> 3) & 7);
2412         }
2413       else if (op2 == 0x2b)
2414         {
2415           // subl %gs:XX(%reg1),%reg2  ==>  subl $YY,%reg2
2416           view[-2] = 0x81;
2417           view[-1] = 0xe8 | ((op1 >> 3) & 7);
2418         }
2419       else if (op2 == 0x03)
2420         {
2421           // addl %gs:XX(%reg1),%reg2  ==>  addl $YY,$reg2
2422           view[-2] = 0x81;
2423           view[-1] = 0xc0 | ((op1 >> 3) & 7);
2424         }
2425       else
2426         tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
2427     }
2428
2429   value = tls_segment->memsz() - value;
2430   if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE)
2431     value = - value;
2432
2433   Relocate_functions<32, false>::rel32(view, value);
2434 }
2435
2436 // Relocate section data.
2437
2438 void
2439 Target_i386::relocate_section(const Relocate_info<32, false>* relinfo,
2440                               unsigned int sh_type,
2441                               const unsigned char* prelocs,
2442                               size_t reloc_count,
2443                               Output_section* output_section,
2444                               bool needs_special_offset_handling,
2445                               unsigned char* view,
2446                               elfcpp::Elf_types<32>::Elf_Addr address,
2447                               section_size_type view_size,
2448                               const Reloc_symbol_changes* reloc_symbol_changes)
2449 {
2450   gold_assert(sh_type == elfcpp::SHT_REL);
2451
2452   gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL,
2453                          Target_i386::Relocate>(
2454     relinfo,
2455     this,
2456     prelocs,
2457     reloc_count,
2458     output_section,
2459     needs_special_offset_handling,
2460     view,
2461     address,
2462     view_size,
2463     reloc_symbol_changes);
2464 }
2465
2466 // Return the size of a relocation while scanning during a relocatable
2467 // link.
2468
2469 unsigned int
2470 Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
2471     unsigned int r_type,
2472     Relobj* object)
2473 {
2474   switch (r_type)
2475     {
2476     case elfcpp::R_386_NONE:
2477     case elfcpp::R_386_GNU_VTINHERIT:
2478     case elfcpp::R_386_GNU_VTENTRY:
2479     case elfcpp::R_386_TLS_GD:            // Global-dynamic
2480     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
2481     case elfcpp::R_386_TLS_DESC_CALL:
2482     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
2483     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
2484     case elfcpp::R_386_TLS_IE:            // Initial-exec
2485     case elfcpp::R_386_TLS_IE_32:
2486     case elfcpp::R_386_TLS_GOTIE:
2487     case elfcpp::R_386_TLS_LE:            // Local-exec
2488     case elfcpp::R_386_TLS_LE_32:
2489       return 0;
2490
2491     case elfcpp::R_386_32:
2492     case elfcpp::R_386_PC32:
2493     case elfcpp::R_386_GOT32:
2494     case elfcpp::R_386_PLT32:
2495     case elfcpp::R_386_GOTOFF:
2496     case elfcpp::R_386_GOTPC:
2497      return 4;
2498
2499     case elfcpp::R_386_16:
2500     case elfcpp::R_386_PC16:
2501       return 2;
2502
2503     case elfcpp::R_386_8:
2504     case elfcpp::R_386_PC8:
2505       return 1;
2506
2507       // These are relocations which should only be seen by the
2508       // dynamic linker, and should never be seen here.
2509     case elfcpp::R_386_COPY:
2510     case elfcpp::R_386_GLOB_DAT:
2511     case elfcpp::R_386_JUMP_SLOT:
2512     case elfcpp::R_386_RELATIVE:
2513     case elfcpp::R_386_TLS_TPOFF:
2514     case elfcpp::R_386_TLS_DTPMOD32:
2515     case elfcpp::R_386_TLS_DTPOFF32:
2516     case elfcpp::R_386_TLS_TPOFF32:
2517     case elfcpp::R_386_TLS_DESC:
2518       object->error(_("unexpected reloc %u in object file"), r_type);
2519       return 0;
2520
2521     case elfcpp::R_386_32PLT:
2522     case elfcpp::R_386_TLS_GD_32:
2523     case elfcpp::R_386_TLS_GD_PUSH:
2524     case elfcpp::R_386_TLS_GD_CALL:
2525     case elfcpp::R_386_TLS_GD_POP:
2526     case elfcpp::R_386_TLS_LDM_32:
2527     case elfcpp::R_386_TLS_LDM_PUSH:
2528     case elfcpp::R_386_TLS_LDM_CALL:
2529     case elfcpp::R_386_TLS_LDM_POP:
2530     case elfcpp::R_386_USED_BY_INTEL_200:
2531     default:
2532       object->error(_("unsupported reloc %u in object file"), r_type);
2533       return 0;
2534     }
2535 }
2536
2537 // Scan the relocs during a relocatable link.
2538
2539 void
2540 Target_i386::scan_relocatable_relocs(Symbol_table* symtab,
2541                                      Layout* layout,
2542                                      Sized_relobj<32, false>* object,
2543                                      unsigned int data_shndx,
2544                                      unsigned int sh_type,
2545                                      const unsigned char* prelocs,
2546                                      size_t reloc_count,
2547                                      Output_section* output_section,
2548                                      bool needs_special_offset_handling,
2549                                      size_t local_symbol_count,
2550                                      const unsigned char* plocal_symbols,
2551                                      Relocatable_relocs* rr)
2552 {
2553   gold_assert(sh_type == elfcpp::SHT_REL);
2554
2555   typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_REL,
2556     Relocatable_size_for_reloc> Scan_relocatable_relocs;
2557
2558   gold::scan_relocatable_relocs<32, false, elfcpp::SHT_REL,
2559       Scan_relocatable_relocs>(
2560     symtab,
2561     layout,
2562     object,
2563     data_shndx,
2564     prelocs,
2565     reloc_count,
2566     output_section,
2567     needs_special_offset_handling,
2568     local_symbol_count,
2569     plocal_symbols,
2570     rr);
2571 }
2572
2573 // Relocate a section during a relocatable link.
2574
2575 void
2576 Target_i386::relocate_for_relocatable(
2577     const Relocate_info<32, false>* relinfo,
2578     unsigned int sh_type,
2579     const unsigned char* prelocs,
2580     size_t reloc_count,
2581     Output_section* output_section,
2582     off_t offset_in_output_section,
2583     const Relocatable_relocs* rr,
2584     unsigned char* view,
2585     elfcpp::Elf_types<32>::Elf_Addr view_address,
2586     section_size_type view_size,
2587     unsigned char* reloc_view,
2588     section_size_type reloc_view_size)
2589 {
2590   gold_assert(sh_type == elfcpp::SHT_REL);
2591
2592   gold::relocate_for_relocatable<32, false, elfcpp::SHT_REL>(
2593     relinfo,
2594     prelocs,
2595     reloc_count,
2596     output_section,
2597     offset_in_output_section,
2598     rr,
2599     view,
2600     view_address,
2601     view_size,
2602     reloc_view,
2603     reloc_view_size);
2604 }
2605
2606 // Return the value to use for a dynamic which requires special
2607 // treatment.  This is how we support equality comparisons of function
2608 // pointers across shared library boundaries, as described in the
2609 // processor specific ABI supplement.
2610
2611 uint64_t
2612 Target_i386::do_dynsym_value(const Symbol* gsym) const
2613 {
2614   gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
2615   return this->plt_section()->address() + gsym->plt_offset();
2616 }
2617
2618 // Return a string used to fill a code section with nops to take up
2619 // the specified length.
2620
2621 std::string
2622 Target_i386::do_code_fill(section_size_type length) const
2623 {
2624   if (length >= 16)
2625     {
2626       // Build a jmp instruction to skip over the bytes.
2627       unsigned char jmp[5];
2628       jmp[0] = 0xe9;
2629       elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
2630       return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
2631               + std::string(length - 5, '\0'));
2632     }
2633
2634   // Nop sequences of various lengths.
2635   const char nop1[1] = { 0x90 };                   // nop
2636   const char nop2[2] = { 0x66, 0x90 };             // xchg %ax %ax
2637   const char nop3[3] = { 0x8d, 0x76, 0x00 };       // leal 0(%esi),%esi
2638   const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00};  // leal 0(%esi,1),%esi
2639   const char nop5[5] = { 0x90, 0x8d, 0x74, 0x26,   // nop
2640                          0x00 };                   // leal 0(%esi,1),%esi
2641   const char nop6[6] = { 0x8d, 0xb6, 0x00, 0x00,   // leal 0L(%esi),%esi
2642                          0x00, 0x00 };
2643   const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00,   // leal 0L(%esi,1),%esi
2644                          0x00, 0x00, 0x00 };
2645   const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26,   // nop
2646                          0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
2647   const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc,   // movl %esi,%esi
2648                          0x27, 0x00, 0x00, 0x00,   // leal 0L(%edi,1),%edi
2649                          0x00 };
2650   const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
2651                            0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
2652                            0x00, 0x00 };
2653   const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
2654                            0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
2655                            0x00, 0x00, 0x00 };
2656   const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2657                            0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
2658                            0x00, 0x00, 0x00, 0x00 };
2659   const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2660                            0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
2661                            0x27, 0x00, 0x00, 0x00,
2662                            0x00 };
2663   const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2664                            0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
2665                            0xbc, 0x27, 0x00, 0x00,
2666                            0x00, 0x00 };
2667   const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
2668                            0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
2669                            0x90, 0x90, 0x90, 0x90,
2670                            0x90, 0x90, 0x90 };
2671
2672   const char* nops[16] = {
2673     NULL,
2674     nop1, nop2, nop3, nop4, nop5, nop6, nop7,
2675     nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
2676   };
2677
2678   return std::string(nops[length], length);
2679 }
2680
2681 // FNOFFSET in section SHNDX in OBJECT is the start of a function
2682 // compiled with -fstack-split.  The function calls non-stack-split
2683 // code.  We have to change the function so that it always ensures
2684 // that it has enough stack space to run some random function.
2685
2686 void
2687 Target_i386::do_calls_non_split(Relobj* object, unsigned int shndx,
2688                                 section_offset_type fnoffset,
2689                                 section_size_type fnsize,
2690                                 unsigned char* view,
2691                                 section_size_type view_size,
2692                                 std::string* from,
2693                                 std::string* to) const
2694 {
2695   // The function starts with a comparison of the stack pointer and a
2696   // field in the TCB.  This is followed by a jump.
2697
2698   // cmp %gs:NN,%esp
2699   if (this->match_view(view, view_size, fnoffset, "\x65\x3b\x25", 3)
2700       && fnsize > 7)
2701     {
2702       // We will call __morestack if the carry flag is set after this
2703       // comparison.  We turn the comparison into an stc instruction
2704       // and some nops.
2705       view[fnoffset] = '\xf9';
2706       this->set_view_to_nop(view, view_size, fnoffset + 1, 6);
2707     }
2708   // lea NN(%esp),%ecx
2709   // lea NN(%esp),%edx
2710   else if ((this->match_view(view, view_size, fnoffset, "\x8d\x8c\x24", 3)
2711             || this->match_view(view, view_size, fnoffset, "\x8d\x94\x24", 3))
2712            && fnsize > 7)
2713     {
2714       // This is loading an offset from the stack pointer for a
2715       // comparison.  The offset is negative, so we decrease the
2716       // offset by the amount of space we need for the stack.  This
2717       // means we will avoid calling __morestack if there happens to
2718       // be plenty of space on the stack already.
2719       unsigned char* pval = view + fnoffset + 3;
2720       uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
2721       val -= parameters->options().split_stack_adjust_size();
2722       elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
2723     }
2724   else
2725     {
2726       if (!object->has_no_split_stack())
2727         object->error(_("failed to match split-stack sequence at "
2728                         "section %u offset %0zx"),
2729                       shndx, static_cast<size_t>(fnoffset));
2730       return;
2731     }
2732
2733   // We have to change the function so that it calls
2734   // __morestack_non_split instead of __morestack.  The former will
2735   // allocate additional stack space.
2736   *from = "__morestack";
2737   *to = "__morestack_non_split";
2738 }
2739
2740 // The selector for i386 object files.
2741
2742 class Target_selector_i386 : public Target_selector_freebsd
2743 {
2744 public:
2745   Target_selector_i386()
2746     : Target_selector_freebsd(elfcpp::EM_386, 32, false,
2747                               "elf32-i386", "elf32-i386-freebsd")
2748   { }
2749
2750   Target*
2751   do_instantiate_target()
2752   { return new Target_i386(); }
2753 };
2754
2755 Target_selector_i386 target_selector_i386;
2756
2757 } // End anonymous namespace.