gold/i386.cc

   1 // i386.cc -- i386 target support for gold.
   2
   3 // Copyright 2006, 2007, 2008, 2009, 2010 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 // A class to handle the PLT data.
  49
  50 class Output_data_plt_i386 : public Output_section_data
  51 {
  52  public:
  53   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
  54
  55   Output_data_plt_i386(Symbol_table*, Layout*, Output_data_space*);
  56
  57   // Add an entry to the PLT.
  58   void
  59   add_entry(Symbol* gsym);
  60
  61   // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
  62   unsigned int
  63   add_local_ifunc_entry(Sized_relobj<32, false>* relobj,
  64                         unsigned int local_sym_index);
  65
  66   // Return the .rel.plt section data.
  67   Reloc_section*
  68   rel_plt() const
  69   { return this->rel_; }
  70
  71   // Return where the TLS_DESC relocations should go.
  72   Reloc_section*
  73   rel_tls_desc(Layout*);
  74
  75   // Return the number of PLT entries.
  76   unsigned int
  77   entry_count() const
  78   { return this->count_; }
  79
  80   // Return the offset of the first non-reserved PLT entry.
  81   static unsigned int
  82   first_plt_entry_offset()
  83   { return plt_entry_size; }
  84
  85   // Return the size of a PLT entry.
  86   static unsigned int
  87   get_plt_entry_size()
  88   { return plt_entry_size; }
  89
  90  protected:
  91   void
  92   do_adjust_output_section(Output_section* os);
  93
  94   // Write to a map file.
  95   void
  96   do_print_to_mapfile(Mapfile* mapfile) const
  97   { mapfile->print_output_data(this, _("** PLT")); }
  98
  99  private:
 100   // The size of an entry in the PLT.
 101   static const int plt_entry_size = 16;
 102
 103   // The first entry in the PLT for an executable.
 104   static unsigned char exec_first_plt_entry[plt_entry_size];
 105
 106   // The first entry in the PLT for a shared object.
 107   static unsigned char dyn_first_plt_entry[plt_entry_size];
 108
 109   // Other entries in the PLT for an executable.
 110   static unsigned char exec_plt_entry[plt_entry_size];
 111
 112   // Other entries in the PLT for a shared object.
 113   static unsigned char dyn_plt_entry[plt_entry_size];
 114
 115   // Set the final size.
 116   void
 117   set_final_data_size()
 118   { this->set_data_size((this->count_ + 1) * plt_entry_size); }
 119
 120   // Write out the PLT data.
 121   void
 122   do_write(Output_file*);
 123
 124   // We keep a list of global STT_GNU_IFUNC symbols, each with its
 125   // offset in the GOT.
 126   struct Global_ifunc
 127   {
 128     Symbol* sym;
 129     unsigned int got_offset;
 130   };
 131
 132   // We keep a list of local STT_GNU_IFUNC symbols, each with its
 133   // offset in the GOT.
 134   struct Local_ifunc
 135   {
 136     Sized_relobj<32, false>* object;
 137     unsigned int local_sym_index;
 138     unsigned int got_offset;
 139   };
 140
 141   // The reloc section.
 142   Reloc_section* rel_;
 143   // The TLS_DESC relocations, if necessary.  These must follow the
 144   // regular PLT relocs.
 145   Reloc_section* tls_desc_rel_;
 146   // The .got.plt section.
 147   Output_data_space* got_plt_;
 148   // The number of PLT entries.
 149   unsigned int count_;
 150   // Global STT_GNU_IFUNC symbols.
 151   std::vector<Global_ifunc> global_ifuncs_;
 152   // Local STT_GNU_IFUNC symbols.
 153   std::vector<Local_ifunc> local_ifuncs_;
 154 };
 155
 156 // The i386 target class.
 157 // TLS info comes from
 158 //   http://people.redhat.com/drepper/tls.pdf
 159 //   http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
 160
 161 class Target_i386 : public Target_freebsd<32, false>
 162 {
 163  public:
 164   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
 165
 166   Target_i386()
 167     : Target_freebsd<32, false>(&i386_info),
 168       got_(NULL), plt_(NULL), got_plt_(NULL), got_tlsdesc_(NULL),
 169       global_offset_table_(NULL), rel_dyn_(NULL),
 170       copy_relocs_(elfcpp::R_386_COPY), dynbss_(NULL),
 171       got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
 172   { }
 173
 174   inline bool
 175   can_check_for_function_pointers() const
 176   { return true; }
 177
 178   virtual bool
 179   can_icf_inline_merge_sections () const
 180   { return true; }
 181
 182   // Process the relocations to determine unreferenced sections for
 183   // garbage collection.
 184   void
 185   gc_process_relocs(Symbol_table* symtab,
 186                     Layout* layout,
 187                     Sized_relobj<32, false>* object,
 188                     unsigned int data_shndx,
 189                     unsigned int sh_type,
 190                     const unsigned char* prelocs,
 191                     size_t reloc_count,
 192                     Output_section* output_section,
 193                     bool needs_special_offset_handling,
 194                     size_t local_symbol_count,
 195                     const unsigned char* plocal_symbols);
 196
 197   // Scan the relocations to look for symbol adjustments.
 198   void
 199   scan_relocs(Symbol_table* symtab,
 200               Layout* layout,
 201               Sized_relobj<32, false>* object,
 202               unsigned int data_shndx,
 203               unsigned int sh_type,
 204               const unsigned char* prelocs,
 205               size_t reloc_count,
 206               Output_section* output_section,
 207               bool needs_special_offset_handling,
 208               size_t local_symbol_count,
 209               const unsigned char* plocal_symbols);
 210
 211   // Finalize the sections.
 212   void
 213   do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
 214
 215   // Return the value to use for a dynamic which requires special
 216   // treatment.
 217   uint64_t
 218   do_dynsym_value(const Symbol*) const;
 219
 220   // Relocate a section.
 221   void
 222   relocate_section(const Relocate_info<32, false>*,
 223                    unsigned int sh_type,
 224                    const unsigned char* prelocs,
 225                    size_t reloc_count,
 226                    Output_section* output_section,
 227                    bool needs_special_offset_handling,
 228                    unsigned char* view,
 229                    elfcpp::Elf_types<32>::Elf_Addr view_address,
 230                    section_size_type view_size,
 231                    const Reloc_symbol_changes*);
 232
 233   // Scan the relocs during a relocatable link.
 234   void
 235   scan_relocatable_relocs(Symbol_table* symtab,
 236                           Layout* layout,
 237                           Sized_relobj<32, false>* object,
 238                           unsigned int data_shndx,
 239                           unsigned int sh_type,
 240                           const unsigned char* prelocs,
 241                           size_t reloc_count,
 242                           Output_section* output_section,
 243                           bool needs_special_offset_handling,
 244                           size_t local_symbol_count,
 245                           const unsigned char* plocal_symbols,
 246                           Relocatable_relocs*);
 247
 248   // Relocate a section during a relocatable link.
 249   void
 250   relocate_for_relocatable(const Relocate_info<32, false>*,
 251                            unsigned int sh_type,
 252                            const unsigned char* prelocs,
 253                            size_t reloc_count,
 254                            Output_section* output_section,
 255                            off_t offset_in_output_section,
 256                            const Relocatable_relocs*,
 257                            unsigned char* view,
 258                            elfcpp::Elf_types<32>::Elf_Addr view_address,
 259                            section_size_type view_size,
 260                            unsigned char* reloc_view,
 261                            section_size_type reloc_view_size);
 262
 263   // Return a string used to fill a code section with nops.
 264   std::string
 265   do_code_fill(section_size_type length) const;
 266
 267   // Return whether SYM is defined by the ABI.
 268   bool
 269   do_is_defined_by_abi(const Symbol* sym) const
 270   { return strcmp(sym->name(), "___tls_get_addr") == 0; }
 271
 272   // Return whether a symbol name implies a local label.  The UnixWare
 273   // 2.1 cc generates temporary symbols that start with .X, so we
 274   // recognize them here.  FIXME: do other SVR4 compilers also use .X?.
 275   // If so, we should move the .X recognition into
 276   // Target::do_is_local_label_name.
 277   bool
 278   do_is_local_label_name(const char* name) const
 279   {
 280     if (name[0] == '.' && name[1] == 'X')
 281       return true;
 282     return Target::do_is_local_label_name(name);
 283   }
 284
 285   // Return the PLT section.
 286   Output_data*
 287   do_plt_section_for_global(const Symbol*) const
 288   { return this->plt_section(); }
 289
 290   Output_data*
 291   do_plt_section_for_local(const Relobj*, unsigned int) const
 292   { return this->plt_section(); }
 293
 294   // Return whether SYM is call to a non-split function.
 295   bool
 296   do_is_call_to_non_split(const Symbol* sym, unsigned int) const;
 297
 298   // Adjust -fsplit-stack code which calls non-split-stack code.
 299   void
 300   do_calls_non_split(Relobj* object, unsigned int shndx,
 301                      section_offset_type fnoffset, section_size_type fnsize,
 302                      unsigned char* view, section_size_type view_size,
 303                      std::string* from, std::string* to) const;
 304
 305   // Return the size of the GOT section.
 306   section_size_type
 307   got_size() const
 308   {
 309     gold_assert(this->got_ != NULL);
 310     return this->got_->data_size();
 311   }
 312
 313   // Return the number of entries in the GOT.
 314   unsigned int
 315   got_entry_count() const
 316   {
 317     if (this->got_ == NULL)
 318       return 0;
 319     return this->got_size() / 4;
 320   }
 321
 322   // Return the number of entries in the PLT.
 323   unsigned int
 324   plt_entry_count() const;
 325
 326   // Return the offset of the first non-reserved PLT entry.
 327   unsigned int
 328   first_plt_entry_offset() const;
 329
 330   // Return the size of each PLT entry.
 331   unsigned int
 332   plt_entry_size() const;
 333
 334  private:
 335   // The class which scans relocations.
 336   struct Scan
 337   {
 338     static inline int
 339
 340     get_reference_flags(unsigned int r_type);
 341
 342     inline void
 343     local(Symbol_table* symtab, Layout* layout, Target_i386* target,
 344           Sized_relobj<32, false>* object,
 345           unsigned int data_shndx,
 346           Output_section* output_section,
 347           const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
 348           const elfcpp::Sym<32, false>& lsym);
 349
 350     inline void
 351     global(Symbol_table* symtab, Layout* layout, Target_i386* target,
 352            Sized_relobj<32, false>* object,
 353            unsigned int data_shndx,
 354            Output_section* output_section,
 355            const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
 356            Symbol* gsym);
 357
 358     inline bool
 359     local_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
 360                                         Target_i386* target,
 361                                         Sized_relobj<32, false>* object,
 362                                         unsigned int data_shndx,
 363                                         Output_section* output_section,
 364                                         const elfcpp::Rel<32, false>& reloc,
 365                                         unsigned int r_type,
 366                                         const elfcpp::Sym<32, false>& lsym);
 367
 368     inline bool
 369     global_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
 370                                          Target_i386* target,
 371                                          Sized_relobj<32, false>* object,
 372                                          unsigned int data_shndx,
 373                                          Output_section* output_section,
 374                                          const elfcpp::Rel<32, false>& reloc,
 375                                          unsigned int r_type,
 376                                          Symbol* gsym);
 377
 378     inline bool
 379     possible_function_pointer_reloc(unsigned int r_type);
 380
 381     bool
 382     reloc_needs_plt_for_ifunc(Sized_relobj<32, false>*, unsigned int r_type);
 383
 384     static void
 385     unsupported_reloc_local(Sized_relobj<32, false>*, unsigned int r_type);
 386
 387     static void
 388     unsupported_reloc_global(Sized_relobj<32, false>*, unsigned int r_type,
 389                              Symbol*);
 390   };
 391
 392   // The class which implements relocation.
 393   class Relocate
 394   {
 395    public:
 396     Relocate()
 397       : skip_call_tls_get_addr_(false),
 398         local_dynamic_type_(LOCAL_DYNAMIC_NONE)
 399     { }
 400
 401     ~Relocate()
 402     {
 403       if (this->skip_call_tls_get_addr_)
 404         {
 405           // FIXME: This needs to specify the location somehow.
 406           gold_error(_("missing expected TLS relocation"));
 407         }
 408     }
 409
 410     // Return whether the static relocation needs to be applied.
 411     inline bool
 412     should_apply_static_reloc(const Sized_symbol<32>* gsym,
 413                               unsigned int r_type,
 414                               bool is_32bit,
 415                               Output_section* output_section);
 416
 417     // Do a relocation.  Return false if the caller should not issue
 418     // any warnings about this relocation.
 419     inline bool
 420     relocate(const Relocate_info<32, false>*, Target_i386*, Output_section*,
 421              size_t relnum, const elfcpp::Rel<32, false>&,
 422              unsigned int r_type, const Sized_symbol<32>*,
 423              const Symbol_value<32>*,
 424              unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
 425              section_size_type);
 426
 427    private:
 428     // Do a TLS relocation.
 429     inline void
 430     relocate_tls(const Relocate_info<32, false>*, Target_i386* target,
 431                  size_t relnum, const elfcpp::Rel<32, false>&,
 432                  unsigned int r_type, const Sized_symbol<32>*,
 433                  const Symbol_value<32>*,
 434                  unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
 435                  section_size_type);
 436
 437     // Do a TLS General-Dynamic to Initial-Exec transition.
 438     inline void
 439     tls_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
 440                  Output_segment* tls_segment,
 441                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 442                  elfcpp::Elf_types<32>::Elf_Addr value,
 443                  unsigned char* view,
 444                  section_size_type view_size);
 445
 446     // Do a TLS General-Dynamic to Local-Exec transition.
 447     inline void
 448     tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
 449                  Output_segment* tls_segment,
 450                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 451                  elfcpp::Elf_types<32>::Elf_Addr value,
 452                  unsigned char* view,
 453                  section_size_type view_size);
 454
 455     // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
 456     // transition.
 457     inline void
 458     tls_desc_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
 459                       Output_segment* tls_segment,
 460                       const elfcpp::Rel<32, false>&, unsigned int r_type,
 461                       elfcpp::Elf_types<32>::Elf_Addr value,
 462                       unsigned char* view,
 463                       section_size_type view_size);
 464
 465     // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
 466     // transition.
 467     inline void
 468     tls_desc_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
 469                       Output_segment* tls_segment,
 470                       const elfcpp::Rel<32, false>&, unsigned int r_type,
 471                       elfcpp::Elf_types<32>::Elf_Addr value,
 472                       unsigned char* view,
 473                       section_size_type view_size);
 474
 475     // Do a TLS Local-Dynamic to Local-Exec transition.
 476     inline void
 477     tls_ld_to_le(const Relocate_info<32, false>*, size_t relnum,
 478                  Output_segment* tls_segment,
 479                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 480                  elfcpp::Elf_types<32>::Elf_Addr value,
 481                  unsigned char* view,
 482                  section_size_type view_size);
 483
 484     // Do a TLS Initial-Exec to Local-Exec transition.
 485     static inline void
 486     tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum,
 487                  Output_segment* tls_segment,
 488                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 489                  elfcpp::Elf_types<32>::Elf_Addr value,
 490                  unsigned char* view,
 491                  section_size_type view_size);
 492
 493     // We need to keep track of which type of local dynamic relocation
 494     // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
 495     enum Local_dynamic_type
 496     {
 497       LOCAL_DYNAMIC_NONE,
 498       LOCAL_DYNAMIC_SUN,
 499       LOCAL_DYNAMIC_GNU
 500     };
 501
 502     // This is set if we should skip the next reloc, which should be a
 503     // PLT32 reloc against ___tls_get_addr.
 504     bool skip_call_tls_get_addr_;
 505     // The type of local dynamic relocation we have seen in the section
 506     // being relocated, if any.
 507     Local_dynamic_type local_dynamic_type_;
 508   };
 509
 510   // A class which returns the size required for a relocation type,
 511   // used while scanning relocs during a relocatable link.
 512   class Relocatable_size_for_reloc
 513   {
 514    public:
 515     unsigned int
 516     get_size_for_reloc(unsigned int, Relobj*);
 517   };
 518
 519   // Adjust TLS relocation type based on the options and whether this
 520   // is a local symbol.
 521   static tls::Tls_optimization
 522   optimize_tls_reloc(bool is_final, int r_type);
 523
 524   // Get the GOT section, creating it if necessary.
 525   Output_data_got<32, false>*
 526   got_section(Symbol_table*, Layout*);
 527
 528   // Get the GOT PLT section.
 529   Output_data_space*
 530   got_plt_section() const
 531   {
 532     gold_assert(this->got_plt_ != NULL);
 533     return this->got_plt_;
 534   }
 535
 536   // Get the GOT section for TLSDESC entries.
 537   Output_data_got<32, false>*
 538   got_tlsdesc_section() const
 539   {
 540     gold_assert(this->got_tlsdesc_ != NULL);
 541     return this->got_tlsdesc_;
 542   }
 543
 544   // Create the PLT section.
 545   void
 546   make_plt_section(Symbol_table* symtab, Layout* layout);
 547
 548   // Create a PLT entry for a global symbol.
 549   void
 550   make_plt_entry(Symbol_table*, Layout*, Symbol*);
 551
 552   // Create a PLT entry for a local STT_GNU_IFUNC symbol.
 553   void
 554   make_local_ifunc_plt_entry(Symbol_table*, Layout*,
 555                              Sized_relobj<32, false>* relobj,
 556                              unsigned int local_sym_index);
 557
 558   // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
 559   void
 560   define_tls_base_symbol(Symbol_table*, Layout*);
 561
 562   // Create a GOT entry for the TLS module index.
 563   unsigned int
 564   got_mod_index_entry(Symbol_table* symtab, Layout* layout,
 565                       Sized_relobj<32, false>* object);
 566
 567   // Get the PLT section.
 568   Output_data_plt_i386*
 569   plt_section() const
 570   {
 571     gold_assert(this->plt_ != NULL);
 572     return this->plt_;
 573   }
 574
 575   // Get the dynamic reloc section, creating it if necessary.
 576   Reloc_section*
 577   rel_dyn_section(Layout*);
 578
 579   // Get the section to use for TLS_DESC relocations.
 580   Reloc_section*
 581   rel_tls_desc_section(Layout*) const;
 582
 583   // Add a potential copy relocation.
 584   void
 585   copy_reloc(Symbol_table* symtab, Layout* layout,
 586              Sized_relobj<32, false>* object,
 587              unsigned int shndx, Output_section* output_section,
 588              Symbol* sym, const elfcpp::Rel<32, false>& reloc)
 589   {
 590     this->copy_relocs_.copy_reloc(symtab, layout,
 591                                   symtab->get_sized_symbol<32>(sym),
 592                                   object, shndx, output_section, reloc,
 593                                   this->rel_dyn_section(layout));
 594   }
 595
 596   // Information about this specific target which we pass to the
 597   // general Target structure.
 598   static const Target::Target_info i386_info;
 599
 600   // The types of GOT entries needed for this platform.
 601   // These values are exposed to the ABI in an incremental link.
 602   // Do not renumber existing values without changing the version
 603   // number of the .gnu_incremental_inputs section.
 604   enum Got_type
 605   {
 606     GOT_TYPE_STANDARD = 0,      // GOT entry for a regular symbol
 607     GOT_TYPE_TLS_NOFFSET = 1,   // GOT entry for negative TLS offset
 608     GOT_TYPE_TLS_OFFSET = 2,    // GOT entry for positive TLS offset
 609     GOT_TYPE_TLS_PAIR = 3,      // GOT entry for TLS module/offset pair
 610     GOT_TYPE_TLS_DESC = 4       // GOT entry for TLS_DESC pair
 611   };
 612
 613   // The GOT section.
 614   Output_data_got<32, false>* got_;
 615   // The PLT section.
 616   Output_data_plt_i386* plt_;
 617   // The GOT PLT section.
 618   Output_data_space* got_plt_;
 619   // The GOT section for TLSDESC relocations.
 620   Output_data_got<32, false>* got_tlsdesc_;
 621   // The _GLOBAL_OFFSET_TABLE_ symbol.
 622   Symbol* global_offset_table_;
 623   // The dynamic reloc section.
 624   Reloc_section* rel_dyn_;
 625   // Relocs saved to avoid a COPY reloc.
 626   Copy_relocs<elfcpp::SHT_REL, 32, false> copy_relocs_;
 627   // Space for variables copied with a COPY reloc.
 628   Output_data_space* dynbss_;
 629   // Offset of the GOT entry for the TLS module index.
 630   unsigned int got_mod_index_offset_;
 631   // True if the _TLS_MODULE_BASE_ symbol has been defined.
 632   bool tls_base_symbol_defined_;
 633 };
 634
 635 const Target::Target_info Target_i386::i386_info =
 636 {
 637   32,                   // size
 638   false,                // is_big_endian
 639   elfcpp::EM_386,       // machine_code
 640   false,                // has_make_symbol
 641   false,                // has_resolve
 642   true,                 // has_code_fill
 643   true,                 // is_default_stack_executable
 644   '\0',                 // wrap_char
 645   "/usr/lib/libc.so.1", // dynamic_linker
 646   0x08048000,           // default_text_segment_address
 647   0x1000,               // abi_pagesize (overridable by -z max-page-size)
 648   0x1000,               // common_pagesize (overridable by -z common-page-size)
 649   elfcpp::SHN_UNDEF,    // small_common_shndx
 650   elfcpp::SHN_UNDEF,    // large_common_shndx
 651   0,                    // small_common_section_flags
 652   0,                    // large_common_section_flags
 653   NULL,                 // attributes_section
 654   NULL                  // attributes_vendor
 655 };
 656
 657 // Get the GOT section, creating it if necessary.
 658
 659 Output_data_got<32, false>*
 660 Target_i386::got_section(Symbol_table* symtab, Layout* layout)
 661 {
 662   if (this->got_ == NULL)
 663     {
 664       gold_assert(symtab != NULL && layout != NULL);
 665
 666       this->got_ = new Output_data_got<32, false>();
 667
 668       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
 669                                       (elfcpp::SHF_ALLOC
 670                                        | elfcpp::SHF_WRITE),
 671                                       this->got_, ORDER_RELRO_LAST, true);
 672
 673       this->got_plt_ = new Output_data_space(4, "** GOT PLT");
 674       layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
 675                                       (elfcpp::SHF_ALLOC
 676                                        | elfcpp::SHF_WRITE),
 677                                       this->got_plt_, ORDER_NON_RELRO_FIRST,
 678                                       false);
 679
 680       // The first three entries are reserved.
 681       this->got_plt_->set_current_data_size(3 * 4);
 682
 683       // Those bytes can go into the relro segment.
 684       layout->increase_relro(3 * 4);
 685
 686       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
 687       this->global_offset_table_ =
 688         symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
 689                                       Symbol_table::PREDEFINED,
 690                                       this->got_plt_,
 691                                       0, 0, elfcpp::STT_OBJECT,
 692                                       elfcpp::STB_LOCAL,
 693                                       elfcpp::STV_HIDDEN, 0,
 694                                       false, false);
 695
 696       // If there are any TLSDESC relocations, they get GOT entries in
 697       // .got.plt after the jump slot entries.
 698       this->got_tlsdesc_ = new Output_data_got<32, false>();
 699       layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
 700                                       (elfcpp::SHF_ALLOC
 701                                        | elfcpp::SHF_WRITE),
 702                                       this->got_tlsdesc_,
 703                                       ORDER_NON_RELRO_FIRST, false);
 704     }
 705
 706   return this->got_;
 707 }
 708
 709 // Get the dynamic reloc section, creating it if necessary.
 710
 711 Target_i386::Reloc_section*
 712 Target_i386::rel_dyn_section(Layout* layout)
 713 {
 714   if (this->rel_dyn_ == NULL)
 715     {
 716       gold_assert(layout != NULL);
 717       this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
 718       layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
 719                                       elfcpp::SHF_ALLOC, this->rel_dyn_,
 720                                       ORDER_DYNAMIC_RELOCS, false);
 721     }
 722   return this->rel_dyn_;
 723 }
 724
 725 // Create the PLT section.  The ordinary .got section is an argument,
 726 // since we need to refer to the start.  We also create our own .got
 727 // section just for PLT entries.
 728
 729 Output_data_plt_i386::Output_data_plt_i386(Symbol_table* symtab,
 730                                            Layout* layout,
 731                                            Output_data_space* got_plt)
 732   : Output_section_data(4), tls_desc_rel_(NULL), got_plt_(got_plt), count_(0),
 733     global_ifuncs_(), local_ifuncs_()
 734 {
 735   this->rel_ = new Reloc_section(false);
 736   layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
 737                                   elfcpp::SHF_ALLOC, this->rel_,
 738                                   ORDER_DYNAMIC_PLT_RELOCS, false);
 739
 740   if (parameters->doing_static_link())
 741     {
 742       // A statically linked executable will only have a .rel.plt
 743       // section to hold R_386_IRELATIVE relocs for STT_GNU_IFUNC
 744       // symbols.  The library will use these symbols to locate the
 745       // IRELATIVE relocs at program startup time.
 746       symtab->define_in_output_data("__rel_iplt_start", NULL,
 747                                     Symbol_table::PREDEFINED,
 748                                     this->rel_, 0, 0, elfcpp::STT_NOTYPE,
 749                                     elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN,
 750                                     0, false, true);
 751       symtab->define_in_output_data("__rel_iplt_end", NULL,
 752                                     Symbol_table::PREDEFINED,
 753                                     this->rel_, 0, 0, elfcpp::STT_NOTYPE,
 754                                     elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN,
 755                                     0, true, true);
 756     }
 757 }
 758
 759 void
 760 Output_data_plt_i386::do_adjust_output_section(Output_section* os)
 761 {
 762   // UnixWare sets the entsize of .plt to 4, and so does the old GNU
 763   // linker, and so do we.
 764   os->set_entsize(4);
 765 }
 766
 767 // Add an entry to the PLT.
 768
 769 void
 770 Output_data_plt_i386::add_entry(Symbol* gsym)
 771 {
 772   gold_assert(!gsym->has_plt_offset());
 773
 774   // Note that when setting the PLT offset we skip the initial
 775   // reserved PLT entry.
 776   gsym->set_plt_offset((this->count_ + 1) * plt_entry_size);
 777
 778   ++this->count_;
 779
 780   section_offset_type got_offset = this->got_plt_->current_data_size();
 781
 782   // Every PLT entry needs a GOT entry which points back to the PLT
 783   // entry (this will be changed by the dynamic linker, normally
 784   // lazily when the function is called).
 785   this->got_plt_->set_current_data_size(got_offset + 4);
 786
 787   // Every PLT entry needs a reloc.
 788   if (gsym->type() == elfcpp::STT_GNU_IFUNC
 789       && gsym->can_use_relative_reloc(false))
 790     {
 791       this->rel_->add_symbolless_global_addend(gsym, elfcpp::R_386_IRELATIVE,
 792                                                this->got_plt_, got_offset);
 793       struct Global_ifunc gi;
 794       gi.sym = gsym;
 795       gi.got_offset = got_offset;
 796       this->global_ifuncs_.push_back(gi);
 797     }
 798   else
 799     {
 800       gsym->set_needs_dynsym_entry();
 801       this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_,
 802                              got_offset);
 803     }
 804
 805   // Note that we don't need to save the symbol.  The contents of the
 806   // PLT are independent of which symbols are used.  The symbols only
 807   // appear in the relocations.
 808 }
 809
 810 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.  Return
 811 // the PLT offset.
 812
 813 unsigned int
 814 Output_data_plt_i386::add_local_ifunc_entry(Sized_relobj<32, false>* relobj,
 815                                             unsigned int local_sym_index)
 816 {
 817   unsigned int plt_offset = (this->count_ + 1) * plt_entry_size;
 818   ++this->count_;
 819
 820   section_offset_type got_offset = this->got_plt_->current_data_size();
 821
 822   // Every PLT entry needs a GOT entry which points back to the PLT
 823   // entry.
 824   this->got_plt_->set_current_data_size(got_offset + 4);
 825
 826   // Every PLT entry needs a reloc.
 827   this->rel_->add_symbolless_local_addend(relobj, local_sym_index,
 828                                           elfcpp::R_386_IRELATIVE,
 829                                           this->got_plt_, got_offset);
 830
 831   struct Local_ifunc li;
 832   li.object = relobj;
 833   li.local_sym_index = local_sym_index;
 834   li.got_offset = got_offset;
 835   this->local_ifuncs_.push_back(li);
 836
 837   return plt_offset;
 838 }
 839
 840 // Return where the TLS_DESC relocations should go, creating it if
 841 // necessary. These follow the JUMP_SLOT relocations.
 842
 843 Output_data_plt_i386::Reloc_section*
 844 Output_data_plt_i386::rel_tls_desc(Layout* layout)
 845 {
 846   if (this->tls_desc_rel_ == NULL)
 847     {
 848       this->tls_desc_rel_ = new Reloc_section(false);
 849       layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
 850                                       elfcpp::SHF_ALLOC, this->tls_desc_rel_,
 851                                       ORDER_DYNAMIC_PLT_RELOCS, false);
 852       gold_assert(this->tls_desc_rel_->output_section() ==
 853                   this->rel_->output_section());
 854     }
 855   return this->tls_desc_rel_;
 856 }
 857
 858 // The first entry in the PLT for an executable.
 859
 860 unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] =
 861 {
 862   0xff, 0x35,   // pushl contents of memory address
 863   0, 0, 0, 0,   // replaced with address of .got + 4
 864   0xff, 0x25,   // jmp indirect
 865   0, 0, 0, 0,   // replaced with address of .got + 8
 866   0, 0, 0, 0    // unused
 867 };
 868
 869 // The first entry in the PLT for a shared object.
 870
 871 unsigned char Output_data_plt_i386::dyn_first_plt_entry[plt_entry_size] =
 872 {
 873   0xff, 0xb3, 4, 0, 0, 0,       // pushl 4(%ebx)
 874   0xff, 0xa3, 8, 0, 0, 0,       // jmp *8(%ebx)
 875   0, 0, 0, 0                    // unused
 876 };
 877
 878 // Subsequent entries in the PLT for an executable.
 879
 880 unsigned char Output_data_plt_i386::exec_plt_entry[plt_entry_size] =
 881 {
 882   0xff, 0x25,   // jmp indirect
 883   0, 0, 0, 0,   // replaced with address of symbol in .got
 884   0x68,         // pushl immediate
 885   0, 0, 0, 0,   // replaced with offset into relocation table
 886   0xe9,         // jmp relative
 887   0, 0, 0, 0    // replaced with offset to start of .plt
 888 };
 889
 890 // Subsequent entries in the PLT for a shared object.
 891
 892 unsigned char Output_data_plt_i386::dyn_plt_entry[plt_entry_size] =
 893 {
 894   0xff, 0xa3,   // jmp *offset(%ebx)
 895   0, 0, 0, 0,   // replaced with offset of symbol in .got
 896   0x68,         // pushl immediate
 897   0, 0, 0, 0,   // replaced with offset into relocation table
 898   0xe9,         // jmp relative
 899   0, 0, 0, 0    // replaced with offset to start of .plt
 900 };
 901
 902 // Write out the PLT.  This uses the hand-coded instructions above,
 903 // and adjusts them as needed.  This is all specified by the i386 ELF
 904 // Processor Supplement.
 905
 906 void
 907 Output_data_plt_i386::do_write(Output_file* of)
 908 {
 909   const off_t offset = this->offset();
 910   const section_size_type oview_size =
 911     convert_to_section_size_type(this->data_size());
 912   unsigned char* const oview = of->get_output_view(offset, oview_size);
 913
 914   const off_t got_file_offset = this->got_plt_->offset();
 915   const section_size_type got_size =
 916     convert_to_section_size_type(this->got_plt_->data_size());
 917   unsigned char* const got_view = of->get_output_view(got_file_offset,
 918                                                       got_size);
 919
 920   unsigned char* pov = oview;
 921
 922   elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address();
 923   elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address();
 924
 925   if (parameters->options().output_is_position_independent())
 926     memcpy(pov, dyn_first_plt_entry, plt_entry_size);
 927   else
 928     {
 929       memcpy(pov, exec_first_plt_entry, plt_entry_size);
 930       elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
 931       elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
 932     }
 933   pov += plt_entry_size;
 934
 935   unsigned char* got_pov = got_view;
 936
 937   memset(got_pov, 0, 12);
 938   got_pov += 12;
 939
 940   const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
 941
 942   unsigned int plt_offset = plt_entry_size;
 943   unsigned int plt_rel_offset = 0;
 944   unsigned int got_offset = 12;
 945   const unsigned int count = this->count_;
 946   for (unsigned int i = 0;
 947        i < count;
 948        ++i,
 949          pov += plt_entry_size,
 950          got_pov += 4,
 951          plt_offset += plt_entry_size,
 952          plt_rel_offset += rel_size,
 953          got_offset += 4)
 954     {
 955       // Set and adjust the PLT entry itself.
 956
 957       if (parameters->options().output_is_position_independent())
 958         {
 959           memcpy(pov, dyn_plt_entry, plt_entry_size);
 960           elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
 961         }
 962       else
 963         {
 964           memcpy(pov, exec_plt_entry, plt_entry_size);
 965           elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
 966                                                       (got_address
 967                                                        + got_offset));
 968         }
 969
 970       elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
 971       elfcpp::Swap<32, false>::writeval(pov + 12,
 972                                         - (plt_offset + plt_entry_size));
 973
 974       // Set the entry in the GOT.
 975       elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6);
 976     }
 977
 978   // If any STT_GNU_IFUNC symbols have PLT entries, we need to change
 979   // the GOT to point to the actual symbol value, rather than point to
 980   // the PLT entry.  That will let the dynamic linker call the right
 981   // function when resolving IRELATIVE relocations.
 982   for (std::vector<Global_ifunc>::const_iterator p =
 983          this->global_ifuncs_.begin();
 984        p != this->global_ifuncs_.end();
 985        ++p)
 986     {
 987       const Sized_symbol<32>* ssym =
 988         static_cast<const Sized_symbol<32>*>(p->sym);
 989       elfcpp::Swap<32, false>::writeval(got_view + p->got_offset,
 990                                         ssym->value());
 991     }
 992
 993   for (std::vector<Local_ifunc>::const_iterator p =
 994          this->local_ifuncs_.begin();
 995        p != this->local_ifuncs_.end();
 996        ++p)
 997     {
 998       const Symbol_value<32>* psymval =
 999         p->object->local_symbol(p->local_sym_index);
1000       elfcpp::Swap<32, false>::writeval(got_view + p->got_offset,
1001                                         psymval->value(p->object, 0));
1002     }
1003
1004   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
1005   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
1006
1007   of->write_output_view(offset, oview_size, oview);
1008   of->write_output_view(got_file_offset, got_size, got_view);
1009 }
1010
1011 // Create the PLT section.
1012
1013 void
1014 Target_i386::make_plt_section(Symbol_table* symtab, Layout* layout)
1015 {
1016   if (this->plt_ == NULL)
1017     {
1018       // Create the GOT sections first.
1019       this->got_section(symtab, layout);
1020
1021       this->plt_ = new Output_data_plt_i386(symtab, layout, this->got_plt_);
1022       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
1023                                       (elfcpp::SHF_ALLOC
1024                                        | elfcpp::SHF_EXECINSTR),
1025                                       this->plt_, ORDER_PLT, false);
1026
1027       // Make the sh_info field of .rel.plt point to .plt.
1028       Output_section* rel_plt_os = this->plt_->rel_plt()->output_section();
1029       rel_plt_os->set_info_section(this->plt_->output_section());
1030     }
1031 }
1032
1033 // Create a PLT entry for a global symbol.
1034
1035 void
1036 Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym)
1037 {
1038   if (gsym->has_plt_offset())
1039     return;
1040   if (this->plt_ == NULL)
1041     this->make_plt_section(symtab, layout);
1042   this->plt_->add_entry(gsym);
1043 }
1044
1045 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1046
1047 void
1048 Target_i386::make_local_ifunc_plt_entry(Symbol_table* symtab, Layout* layout,
1049                                         Sized_relobj<32, false>* relobj,
1050                                         unsigned int local_sym_index)
1051 {
1052   if (relobj->local_has_plt_offset(local_sym_index))
1053     return;
1054   if (this->plt_ == NULL)
1055     this->make_plt_section(symtab, layout);
1056   unsigned int plt_offset = this->plt_->add_local_ifunc_entry(relobj,
1057                                                               local_sym_index);
1058   relobj->set_local_plt_offset(local_sym_index, plt_offset);
1059 }
1060
1061 // Return the number of entries in the PLT.
1062
1063 unsigned int
1064 Target_i386::plt_entry_count() const
1065 {
1066   if (this->plt_ == NULL)
1067     return 0;
1068   return this->plt_->entry_count();
1069 }
1070
1071 // Return the offset of the first non-reserved PLT entry.
1072
1073 unsigned int
1074 Target_i386::first_plt_entry_offset() const
1075 {
1076   return Output_data_plt_i386::first_plt_entry_offset();
1077 }
1078
1079 // Return the size of each PLT entry.
1080
1081 unsigned int
1082 Target_i386::plt_entry_size() const
1083 {
1084   return Output_data_plt_i386::get_plt_entry_size();
1085 }
1086
1087 // Get the section to use for TLS_DESC relocations.
1088
1089 Target_i386::Reloc_section*
1090 Target_i386::rel_tls_desc_section(Layout* layout) const
1091 {
1092   return this->plt_section()->rel_tls_desc(layout);
1093 }
1094
1095 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1096
1097 void
1098 Target_i386::define_tls_base_symbol(Symbol_table* symtab, Layout* layout)
1099 {
1100   if (this->tls_base_symbol_defined_)
1101     return;
1102
1103   Output_segment* tls_segment = layout->tls_segment();
1104   if (tls_segment != NULL)
1105     {
1106       bool is_exec = parameters->options().output_is_executable();
1107       symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
1108                                        Symbol_table::PREDEFINED,
1109                                        tls_segment, 0, 0,
1110                                        elfcpp::STT_TLS,
1111                                        elfcpp::STB_LOCAL,
1112                                        elfcpp::STV_HIDDEN, 0,
1113                                        (is_exec
1114                                         ? Symbol::SEGMENT_END
1115                                         : Symbol::SEGMENT_START),
1116                                        true);
1117     }
1118   this->tls_base_symbol_defined_ = true;
1119 }
1120
1121 // Create a GOT entry for the TLS module index.
1122
1123 unsigned int
1124 Target_i386::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
1125                                  Sized_relobj<32, false>* object)
1126 {
1127   if (this->got_mod_index_offset_ == -1U)
1128     {
1129       gold_assert(symtab != NULL && layout != NULL && object != NULL);
1130       Reloc_section* rel_dyn = this->rel_dyn_section(layout);
1131       Output_data_got<32, false>* got = this->got_section(symtab, layout);
1132       unsigned int got_offset = got->add_constant(0);
1133       rel_dyn->add_local(object, 0, elfcpp::R_386_TLS_DTPMOD32, got,
1134                          got_offset);
1135       got->add_constant(0);
1136       this->got_mod_index_offset_ = got_offset;
1137     }
1138   return this->got_mod_index_offset_;
1139 }
1140
1141 // Optimize the TLS relocation type based on what we know about the
1142 // symbol.  IS_FINAL is true if the final address of this symbol is
1143 // known at link time.
1144
1145 tls::Tls_optimization
1146 Target_i386::optimize_tls_reloc(bool is_final, int r_type)
1147 {
1148   // If we are generating a shared library, then we can't do anything
1149   // in the linker.
1150   if (parameters->options().shared())
1151     return tls::TLSOPT_NONE;
1152
1153   switch (r_type)
1154     {
1155     case elfcpp::R_386_TLS_GD:
1156     case elfcpp::R_386_TLS_GOTDESC:
1157     case elfcpp::R_386_TLS_DESC_CALL:
1158       // These are General-Dynamic which permits fully general TLS
1159       // access.  Since we know that we are generating an executable,
1160       // we can convert this to Initial-Exec.  If we also know that
1161       // this is a local symbol, we can further switch to Local-Exec.
1162       if (is_final)
1163         return tls::TLSOPT_TO_LE;
1164       return tls::TLSOPT_TO_IE;
1165
1166     case elfcpp::R_386_TLS_LDM:
1167       // This is Local-Dynamic, which refers to a local symbol in the
1168       // dynamic TLS block.  Since we know that we generating an
1169       // executable, we can switch to Local-Exec.
1170       return tls::TLSOPT_TO_LE;
1171
1172     case elfcpp::R_386_TLS_LDO_32:
1173       // Another type of Local-Dynamic relocation.
1174       return tls::TLSOPT_TO_LE;
1175
1176     case elfcpp::R_386_TLS_IE:
1177     case elfcpp::R_386_TLS_GOTIE:
1178     case elfcpp::R_386_TLS_IE_32:
1179       // These are Initial-Exec relocs which get the thread offset
1180       // from the GOT.  If we know that we are linking against the
1181       // local symbol, we can switch to Local-Exec, which links the
1182       // thread offset into the instruction.
1183       if (is_final)
1184         return tls::TLSOPT_TO_LE;
1185       return tls::TLSOPT_NONE;
1186
1187     case elfcpp::R_386_TLS_LE:
1188     case elfcpp::R_386_TLS_LE_32:
1189       // When we already have Local-Exec, there is nothing further we
1190       // can do.
1191       return tls::TLSOPT_NONE;
1192
1193     default:
1194       gold_unreachable();
1195     }
1196 }
1197
1198 // Get the Reference_flags for a particular relocation.
1199
1200 int
1201 Target_i386::Scan::get_reference_flags(unsigned int r_type)
1202 {
1203   switch (r_type)
1204     {
1205     case elfcpp::R_386_NONE:
1206     case elfcpp::R_386_GNU_VTINHERIT:
1207     case elfcpp::R_386_GNU_VTENTRY:
1208     case elfcpp::R_386_GOTPC:
1209       // No symbol reference.
1210       return 0;
1211
1212     case elfcpp::R_386_32:
1213     case elfcpp::R_386_16:
1214     case elfcpp::R_386_8:
1215       return Symbol::ABSOLUTE_REF;
1216
1217     case elfcpp::R_386_PC32:
1218     case elfcpp::R_386_PC16:
1219     case elfcpp::R_386_PC8:
1220     case elfcpp::R_386_GOTOFF:
1221       return Symbol::RELATIVE_REF;
1222
1223     case elfcpp::R_386_PLT32:
1224       return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
1225
1226     case elfcpp::R_386_GOT32:
1227       // Absolute in GOT.
1228       return Symbol::ABSOLUTE_REF;
1229
1230     case elfcpp::R_386_TLS_GD:            // Global-dynamic
1231     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
1232     case elfcpp::R_386_TLS_DESC_CALL:
1233     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
1234     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
1235     case elfcpp::R_386_TLS_IE:            // Initial-exec
1236     case elfcpp::R_386_TLS_IE_32:
1237     case elfcpp::R_386_TLS_GOTIE:
1238     case elfcpp::R_386_TLS_LE:            // Local-exec
1239     case elfcpp::R_386_TLS_LE_32:
1240       return Symbol::TLS_REF;
1241
1242     case elfcpp::R_386_COPY:
1243     case elfcpp::R_386_GLOB_DAT:
1244     case elfcpp::R_386_JUMP_SLOT:
1245     case elfcpp::R_386_RELATIVE:
1246     case elfcpp::R_386_IRELATIVE:
1247     case elfcpp::R_386_TLS_TPOFF:
1248     case elfcpp::R_386_TLS_DTPMOD32:
1249     case elfcpp::R_386_TLS_DTPOFF32:
1250     case elfcpp::R_386_TLS_TPOFF32:
1251     case elfcpp::R_386_TLS_DESC:
1252     case elfcpp::R_386_32PLT:
1253     case elfcpp::R_386_TLS_GD_32:
1254     case elfcpp::R_386_TLS_GD_PUSH:
1255     case elfcpp::R_386_TLS_GD_CALL:
1256     case elfcpp::R_386_TLS_GD_POP:
1257     case elfcpp::R_386_TLS_LDM_32:
1258     case elfcpp::R_386_TLS_LDM_PUSH:
1259     case elfcpp::R_386_TLS_LDM_CALL:
1260     case elfcpp::R_386_TLS_LDM_POP:
1261     case elfcpp::R_386_USED_BY_INTEL_200:
1262     default:
1263       // Not expected.  We will give an error later.
1264       return 0;
1265     }
1266 }
1267
1268 // Report an unsupported relocation against a local symbol.
1269
1270 void
1271 Target_i386::Scan::unsupported_reloc_local(Sized_relobj<32, false>* object,
1272                                            unsigned int r_type)
1273 {
1274   gold_error(_("%s: unsupported reloc %u against local symbol"),
1275              object->name().c_str(), r_type);
1276 }
1277
1278 // Return whether we need to make a PLT entry for a relocation of a
1279 // given type against a STT_GNU_IFUNC symbol.
1280
1281 bool
1282 Target_i386::Scan::reloc_needs_plt_for_ifunc(Sized_relobj<32, false>* object,
1283                                              unsigned int r_type)
1284 {
1285   int flags = Scan::get_reference_flags(r_type);
1286   if (flags & Symbol::TLS_REF)
1287     gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
1288                object->name().c_str(), r_type);
1289   return flags != 0;
1290 }
1291
1292 // Scan a relocation for a local symbol.
1293
1294 inline void
1295 Target_i386::Scan::local(Symbol_table* symtab,
1296                          Layout* layout,
1297                          Target_i386* target,
1298                          Sized_relobj<32, false>* object,
1299                          unsigned int data_shndx,
1300                          Output_section* output_section,
1301                          const elfcpp::Rel<32, false>& reloc,
1302                          unsigned int r_type,
1303                          const elfcpp::Sym<32, false>& lsym)
1304 {
1305   // A local STT_GNU_IFUNC symbol may require a PLT entry.
1306   if (lsym.get_st_type() == elfcpp::STT_GNU_IFUNC
1307       && this->reloc_needs_plt_for_ifunc(object, r_type))
1308     {
1309       unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1310       target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
1311     }
1312
1313   switch (r_type)
1314     {
1315     case elfcpp::R_386_NONE:
1316     case elfcpp::R_386_GNU_VTINHERIT:
1317     case elfcpp::R_386_GNU_VTENTRY:
1318       break;
1319
1320     case elfcpp::R_386_32:
1321       // If building a shared library (or a position-independent
1322       // executable), we need to create a dynamic relocation for
1323       // this location. The relocation applied at link time will
1324       // apply the link-time value, so we flag the location with
1325       // an R_386_RELATIVE relocation so the dynamic loader can
1326       // relocate it easily.
1327       if (parameters->options().output_is_position_independent())
1328         {
1329           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1330           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1331           rel_dyn->add_local_relative(object, r_sym, elfcpp::R_386_RELATIVE,
1332                                       output_section, data_shndx,
1333                                       reloc.get_r_offset());
1334         }
1335       break;
1336
1337     case elfcpp::R_386_16:
1338     case elfcpp::R_386_8:
1339       // If building a shared library (or a position-independent
1340       // executable), we need to create a dynamic relocation for
1341       // this location. Because the addend needs to remain in the
1342       // data section, we need to be careful not to apply this
1343       // relocation statically.
1344       if (parameters->options().output_is_position_independent())
1345         {
1346           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1347           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1348           if (lsym.get_st_type() != elfcpp::STT_SECTION)
1349             rel_dyn->add_local(object, r_sym, r_type, output_section,
1350                                data_shndx, reloc.get_r_offset());
1351           else
1352             {
1353               gold_assert(lsym.get_st_value() == 0);
1354               unsigned int shndx = lsym.get_st_shndx();
1355               bool is_ordinary;
1356               shndx = object->adjust_sym_shndx(r_sym, shndx,
1357                                                &is_ordinary);
1358               if (!is_ordinary)
1359                 object->error(_("section symbol %u has bad shndx %u"),
1360                               r_sym, shndx);
1361               else
1362                 rel_dyn->add_local_section(object, shndx,
1363                                            r_type, output_section,
1364                                            data_shndx, reloc.get_r_offset());
1365             }
1366         }
1367       break;
1368
1369     case elfcpp::R_386_PC32:
1370     case elfcpp::R_386_PC16:
1371     case elfcpp::R_386_PC8:
1372       break;
1373
1374     case elfcpp::R_386_PLT32:
1375       // Since we know this is a local symbol, we can handle this as a
1376       // PC32 reloc.
1377       break;
1378
1379     case elfcpp::R_386_GOTOFF:
1380     case elfcpp::R_386_GOTPC:
1381       // We need a GOT section.
1382       target->got_section(symtab, layout);
1383       break;
1384
1385     case elfcpp::R_386_GOT32:
1386       {
1387         // The symbol requires a GOT entry.
1388         Output_data_got<32, false>* got = target->got_section(symtab, layout);
1389         unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1390
1391         // For a STT_GNU_IFUNC symbol we want the PLT offset.  That
1392         // lets function pointers compare correctly with shared
1393         // libraries.  Otherwise we would need an IRELATIVE reloc.
1394         bool is_new;
1395         if (lsym.get_st_type() == elfcpp::STT_GNU_IFUNC)
1396           is_new = got->add_local_plt(object, r_sym, GOT_TYPE_STANDARD);
1397         else
1398           is_new = got->add_local(object, r_sym, GOT_TYPE_STANDARD);
1399         if (is_new)
1400           {
1401             // If we are generating a shared object, we need to add a
1402             // dynamic RELATIVE relocation for this symbol's GOT entry.
1403             if (parameters->options().output_is_position_independent())
1404               {
1405                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1406                 unsigned int got_offset =
1407                   object->local_got_offset(r_sym, GOT_TYPE_STANDARD);
1408                 rel_dyn->add_local_relative(object, r_sym,
1409                                             elfcpp::R_386_RELATIVE,
1410                                             got, got_offset);
1411               }
1412           }
1413       }
1414       break;
1415
1416       // These are relocations which should only be seen by the
1417       // dynamic linker, and should never be seen here.
1418     case elfcpp::R_386_COPY:
1419     case elfcpp::R_386_GLOB_DAT:
1420     case elfcpp::R_386_JUMP_SLOT:
1421     case elfcpp::R_386_RELATIVE:
1422     case elfcpp::R_386_IRELATIVE:
1423     case elfcpp::R_386_TLS_TPOFF:
1424     case elfcpp::R_386_TLS_DTPMOD32:
1425     case elfcpp::R_386_TLS_DTPOFF32:
1426     case elfcpp::R_386_TLS_TPOFF32:
1427     case elfcpp::R_386_TLS_DESC:
1428       gold_error(_("%s: unexpected reloc %u in object file"),
1429                  object->name().c_str(), r_type);
1430       break;
1431
1432       // These are initial TLS relocs, which are expected when
1433       // linking.
1434     case elfcpp::R_386_TLS_GD:            // Global-dynamic
1435     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
1436     case elfcpp::R_386_TLS_DESC_CALL:
1437     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
1438     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
1439     case elfcpp::R_386_TLS_IE:            // Initial-exec
1440     case elfcpp::R_386_TLS_IE_32:
1441     case elfcpp::R_386_TLS_GOTIE:
1442     case elfcpp::R_386_TLS_LE:            // Local-exec
1443     case elfcpp::R_386_TLS_LE_32:
1444       {
1445         bool output_is_shared = parameters->options().shared();
1446         const tls::Tls_optimization optimized_type
1447             = Target_i386::optimize_tls_reloc(!output_is_shared, r_type);
1448         switch (r_type)
1449           {
1450           case elfcpp::R_386_TLS_GD:          // Global-dynamic
1451             if (optimized_type == tls::TLSOPT_NONE)
1452               {
1453                 // Create a pair of GOT entries for the module index and
1454                 // dtv-relative offset.
1455                 Output_data_got<32, false>* got
1456                     = target->got_section(symtab, layout);
1457                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1458                 unsigned int shndx = lsym.get_st_shndx();
1459                 bool is_ordinary;
1460                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1461                 if (!is_ordinary)
1462                   object->error(_("local symbol %u has bad shndx %u"),
1463                               r_sym, shndx);
1464                 else
1465                   got->add_local_pair_with_rel(object, r_sym, shndx,
1466                                                GOT_TYPE_TLS_PAIR,
1467                                                target->rel_dyn_section(layout),
1468                                                elfcpp::R_386_TLS_DTPMOD32, 0);
1469               }
1470             else if (optimized_type != tls::TLSOPT_TO_LE)
1471               unsupported_reloc_local(object, r_type);
1472             break;
1473
1474           case elfcpp::R_386_TLS_GOTDESC:     // Global-dynamic (from ~oliva)
1475             target->define_tls_base_symbol(symtab, layout);
1476             if (optimized_type == tls::TLSOPT_NONE)
1477               {
1478                 // Create a double GOT entry with an R_386_TLS_DESC
1479                 // reloc.  The R_386_TLS_DESC reloc is resolved
1480                 // lazily, so the GOT entry needs to be in an area in
1481                 // .got.plt, not .got.  Call got_section to make sure
1482                 // the section has been created.
1483                 target->got_section(symtab, layout);
1484                 Output_data_got<32, false>* got = target->got_tlsdesc_section();
1485                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1486                 if (!object->local_has_got_offset(r_sym, GOT_TYPE_TLS_DESC))
1487                   {
1488                     unsigned int got_offset = got->add_constant(0);
1489                     // The local symbol value is stored in the second
1490                     // GOT entry.
1491                     got->add_local(object, r_sym, GOT_TYPE_TLS_DESC);
1492                     // That set the GOT offset of the local symbol to
1493                     // point to the second entry, but we want it to
1494                     // point to the first.
1495                     object->set_local_got_offset(r_sym, GOT_TYPE_TLS_DESC,
1496                                                  got_offset);
1497                     Reloc_section* rt = target->rel_tls_desc_section(layout);
1498                     rt->add_absolute(elfcpp::R_386_TLS_DESC, got, got_offset);
1499                   }
1500               }
1501             else if (optimized_type != tls::TLSOPT_TO_LE)
1502               unsupported_reloc_local(object, r_type);
1503             break;
1504
1505           case elfcpp::R_386_TLS_DESC_CALL:
1506             break;
1507
1508           case elfcpp::R_386_TLS_LDM:         // Local-dynamic
1509             if (optimized_type == tls::TLSOPT_NONE)
1510               {
1511                 // Create a GOT entry for the module index.
1512                 target->got_mod_index_entry(symtab, layout, object);
1513               }
1514             else if (optimized_type != tls::TLSOPT_TO_LE)
1515               unsupported_reloc_local(object, r_type);
1516             break;
1517
1518           case elfcpp::R_386_TLS_LDO_32:      // Alternate local-dynamic
1519             break;
1520
1521           case elfcpp::R_386_TLS_IE:          // Initial-exec
1522           case elfcpp::R_386_TLS_IE_32:
1523           case elfcpp::R_386_TLS_GOTIE:
1524             layout->set_has_static_tls();
1525             if (optimized_type == tls::TLSOPT_NONE)
1526               {
1527                 // For the R_386_TLS_IE relocation, we need to create a
1528                 // dynamic relocation when building a shared library.
1529                 if (r_type == elfcpp::R_386_TLS_IE
1530                     && parameters->options().shared())
1531                   {
1532                     Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1533                     unsigned int r_sym
1534                         = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1535                     rel_dyn->add_local_relative(object, r_sym,
1536                                                 elfcpp::R_386_RELATIVE,
1537                                                 output_section, data_shndx,
1538                                                 reloc.get_r_offset());
1539                   }
1540                 // Create a GOT entry for the tp-relative offset.
1541                 Output_data_got<32, false>* got
1542                     = target->got_section(symtab, layout);
1543                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1544                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
1545                                            ? elfcpp::R_386_TLS_TPOFF32
1546                                            : elfcpp::R_386_TLS_TPOFF);
1547                 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
1548                                          ? GOT_TYPE_TLS_OFFSET
1549                                          : GOT_TYPE_TLS_NOFFSET);
1550                 got->add_local_with_rel(object, r_sym, got_type,
1551                                         target->rel_dyn_section(layout),
1552                                         dyn_r_type);
1553               }
1554             else if (optimized_type != tls::TLSOPT_TO_LE)
1555               unsupported_reloc_local(object, r_type);
1556             break;
1557
1558           case elfcpp::R_386_TLS_LE:          // Local-exec
1559           case elfcpp::R_386_TLS_LE_32:
1560             layout->set_has_static_tls();
1561             if (output_is_shared)
1562               {
1563                 // We need to create a dynamic relocation.
1564                 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
1565                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1566                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
1567                                            ? elfcpp::R_386_TLS_TPOFF32
1568                                            : elfcpp::R_386_TLS_TPOFF);
1569                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1570                 rel_dyn->add_local(object, r_sym, dyn_r_type, output_section,
1571                                    data_shndx, reloc.get_r_offset());
1572               }
1573             break;
1574
1575           default:
1576             gold_unreachable();
1577           }
1578       }
1579       break;
1580
1581     case elfcpp::R_386_32PLT:
1582     case elfcpp::R_386_TLS_GD_32:
1583     case elfcpp::R_386_TLS_GD_PUSH:
1584     case elfcpp::R_386_TLS_GD_CALL:
1585     case elfcpp::R_386_TLS_GD_POP:
1586     case elfcpp::R_386_TLS_LDM_32:
1587     case elfcpp::R_386_TLS_LDM_PUSH:
1588     case elfcpp::R_386_TLS_LDM_CALL:
1589     case elfcpp::R_386_TLS_LDM_POP:
1590     case elfcpp::R_386_USED_BY_INTEL_200:
1591     default:
1592       unsupported_reloc_local(object, r_type);
1593       break;
1594     }
1595 }
1596
1597 // Report an unsupported relocation against a global symbol.
1598
1599 void
1600 Target_i386::Scan::unsupported_reloc_global(Sized_relobj<32, false>* object,
1601                                             unsigned int r_type,
1602                                             Symbol* gsym)
1603 {
1604   gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1605              object->name().c_str(), r_type, gsym->demangled_name().c_str());
1606 }
1607
1608 inline bool
1609 Target_i386::Scan::possible_function_pointer_reloc(unsigned int r_type)
1610 {
1611   switch (r_type)
1612     {
1613     case elfcpp::R_386_32:
1614     case elfcpp::R_386_16:
1615     case elfcpp::R_386_8:
1616     case elfcpp::R_386_GOTOFF:
1617     case elfcpp::R_386_GOT32:
1618       {
1619         return true;
1620       }
1621     default:
1622       return false;
1623     }
1624   return false;
1625 }
1626
1627 inline bool
1628 Target_i386::Scan::local_reloc_may_be_function_pointer(
1629   Symbol_table* ,
1630   Layout* ,
1631   Target_i386* ,
1632   Sized_relobj<32, false>* ,
1633   unsigned int ,
1634   Output_section* ,
1635   const elfcpp::Rel<32, false>& ,
1636   unsigned int r_type,
1637   const elfcpp::Sym<32, false>&)
1638 {
1639   return possible_function_pointer_reloc(r_type);
1640 }
1641
1642 inline bool
1643 Target_i386::Scan::global_reloc_may_be_function_pointer(
1644   Symbol_table* ,
1645   Layout* ,
1646   Target_i386* ,
1647   Sized_relobj<32, false>* ,
1648   unsigned int ,
1649   Output_section* ,
1650   const elfcpp::Rel<32, false>& ,
1651   unsigned int r_type,
1652   Symbol*)
1653 {
1654   return possible_function_pointer_reloc(r_type);
1655 }
1656
1657 // Scan a relocation for a global symbol.
1658
1659 inline void
1660 Target_i386::Scan::global(Symbol_table* symtab,
1661                           Layout* layout,
1662                           Target_i386* target,
1663                           Sized_relobj<32, false>* object,
1664                           unsigned int data_shndx,
1665                           Output_section* output_section,
1666                           const elfcpp::Rel<32, false>& reloc,
1667                           unsigned int r_type,
1668                           Symbol* gsym)
1669 {
1670   // A STT_GNU_IFUNC symbol may require a PLT entry.
1671   if (gsym->type() == elfcpp::STT_GNU_IFUNC
1672       && this->reloc_needs_plt_for_ifunc(object, r_type))
1673     target->make_plt_entry(symtab, layout, gsym);
1674
1675   switch (r_type)
1676     {
1677     case elfcpp::R_386_NONE:
1678     case elfcpp::R_386_GNU_VTINHERIT:
1679     case elfcpp::R_386_GNU_VTENTRY:
1680       break;
1681
1682     case elfcpp::R_386_32:
1683     case elfcpp::R_386_16:
1684     case elfcpp::R_386_8:
1685       {
1686         // Make a PLT entry if necessary.
1687         if (gsym->needs_plt_entry())
1688           {
1689             target->make_plt_entry(symtab, layout, gsym);
1690             // Since this is not a PC-relative relocation, we may be
1691             // taking the address of a function. In that case we need to
1692             // set the entry in the dynamic symbol table to the address of
1693             // the PLT entry.
1694             if (gsym->is_from_dynobj() && !parameters->options().shared())
1695               gsym->set_needs_dynsym_value();
1696           }
1697         // Make a dynamic relocation if necessary.
1698         if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
1699           {
1700             if (gsym->may_need_copy_reloc())
1701               {
1702                 target->copy_reloc(symtab, layout, object,
1703                                    data_shndx, output_section, gsym, reloc);
1704               }
1705             else if (r_type == elfcpp::R_386_32
1706                      && gsym->type() == elfcpp::STT_GNU_IFUNC
1707                      && gsym->can_use_relative_reloc(false)
1708                      && !gsym->is_from_dynobj()
1709                      && !gsym->is_undefined()
1710                      && !gsym->is_preemptible())
1711               {
1712                 // Use an IRELATIVE reloc for a locally defined
1713                 // STT_GNU_IFUNC symbol.  This makes a function
1714                 // address in a PIE executable match the address in a
1715                 // shared library that it links against.
1716                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1717                 rel_dyn->add_symbolless_global_addend(gsym,
1718                                                       elfcpp::R_386_IRELATIVE,
1719                                                       output_section,
1720                                                       object, data_shndx,
1721                                                       reloc.get_r_offset());
1722               }
1723             else if (r_type == elfcpp::R_386_32
1724                      && gsym->can_use_relative_reloc(false))
1725               {
1726                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1727                 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1728                                              output_section, object,
1729                                              data_shndx, reloc.get_r_offset());
1730               }
1731             else
1732               {
1733                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1734                 rel_dyn->add_global(gsym, r_type, output_section, object,
1735                                     data_shndx, reloc.get_r_offset());
1736               }
1737           }
1738       }
1739       break;
1740
1741     case elfcpp::R_386_PC32:
1742     case elfcpp::R_386_PC16:
1743     case elfcpp::R_386_PC8:
1744       {
1745         // Make a PLT entry if necessary.
1746         if (gsym->needs_plt_entry())
1747           {
1748             // These relocations are used for function calls only in
1749             // non-PIC code.  For a 32-bit relocation in a shared library,
1750             // we'll need a text relocation anyway, so we can skip the
1751             // PLT entry and let the dynamic linker bind the call directly
1752             // to the target.  For smaller relocations, we should use a
1753             // PLT entry to ensure that the call can reach.
1754             if (!parameters->options().shared()
1755                 || r_type != elfcpp::R_386_PC32)
1756               target->make_plt_entry(symtab, layout, gsym);
1757           }
1758         // Make a dynamic relocation if necessary.
1759         if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
1760           {
1761             if (gsym->may_need_copy_reloc())
1762               {
1763                 target->copy_reloc(symtab, layout, object,
1764                                    data_shndx, output_section, gsym, reloc);
1765               }
1766             else
1767               {
1768                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1769                 rel_dyn->add_global(gsym, r_type, output_section, object,
1770                                     data_shndx, reloc.get_r_offset());
1771               }
1772           }
1773       }
1774       break;
1775
1776     case elfcpp::R_386_GOT32:
1777       {
1778         // The symbol requires a GOT entry.
1779         Output_data_got<32, false>* got = target->got_section(symtab, layout);
1780         if (gsym->final_value_is_known())
1781           {
1782             // For a STT_GNU_IFUNC symbol we want the PLT address.
1783             if (gsym->type() == elfcpp::STT_GNU_IFUNC)
1784               got->add_global_plt(gsym, GOT_TYPE_STANDARD);
1785             else
1786               got->add_global(gsym, GOT_TYPE_STANDARD);
1787           }
1788         else
1789           {
1790             // If this symbol is not fully resolved, we need to add a
1791             // GOT entry with a dynamic relocation.
1792             Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1793             if (gsym->is_from_dynobj()
1794                 || gsym->is_undefined()
1795                 || gsym->is_preemptible()
1796                 || (gsym->type() == elfcpp::STT_GNU_IFUNC
1797                     && parameters->options().output_is_position_independent()))
1798               got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
1799                                        rel_dyn, elfcpp::R_386_GLOB_DAT);
1800             else
1801               {
1802                 // For a STT_GNU_IFUNC symbol we want to write the PLT
1803                 // offset into the GOT, so that function pointer
1804                 // comparisons work correctly.
1805                 bool is_new;
1806                 if (gsym->type() != elfcpp::STT_GNU_IFUNC)
1807                   is_new = got->add_global(gsym, GOT_TYPE_STANDARD);
1808                 else
1809                   {
1810                     is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD);
1811                     // Tell the dynamic linker to use the PLT address
1812                     // when resolving relocations.
1813                     if (gsym->is_from_dynobj()
1814                         && !parameters->options().shared())
1815                       gsym->set_needs_dynsym_value();
1816                   }
1817                 if (is_new)
1818                   {
1819                     unsigned int got_off = gsym->got_offset(GOT_TYPE_STANDARD);
1820                     rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1821                                                  got, got_off);
1822                   }
1823               }
1824           }
1825       }
1826       break;
1827
1828     case elfcpp::R_386_PLT32:
1829       // If the symbol is fully resolved, this is just a PC32 reloc.
1830       // Otherwise we need a PLT entry.
1831       if (gsym->final_value_is_known())
1832         break;
1833       // If building a shared library, we can also skip the PLT entry
1834       // if the symbol is defined in the output file and is protected
1835       // or hidden.
1836       if (gsym->is_defined()
1837           && !gsym->is_from_dynobj()
1838           && !gsym->is_preemptible())
1839         break;
1840       target->make_plt_entry(symtab, layout, gsym);
1841       break;
1842
1843     case elfcpp::R_386_GOTOFF:
1844     case elfcpp::R_386_GOTPC:
1845       // We need a GOT section.
1846       target->got_section(symtab, layout);
1847       break;
1848
1849       // These are relocations which should only be seen by the
1850       // dynamic linker, and should never be seen here.
1851     case elfcpp::R_386_COPY:
1852     case elfcpp::R_386_GLOB_DAT:
1853     case elfcpp::R_386_JUMP_SLOT:
1854     case elfcpp::R_386_RELATIVE:
1855     case elfcpp::R_386_IRELATIVE:
1856     case elfcpp::R_386_TLS_TPOFF:
1857     case elfcpp::R_386_TLS_DTPMOD32:
1858     case elfcpp::R_386_TLS_DTPOFF32:
1859     case elfcpp::R_386_TLS_TPOFF32:
1860     case elfcpp::R_386_TLS_DESC:
1861       gold_error(_("%s: unexpected reloc %u in object file"),
1862                  object->name().c_str(), r_type);
1863       break;
1864
1865       // These are initial tls relocs, which are expected when
1866       // linking.
1867     case elfcpp::R_386_TLS_GD:            // Global-dynamic
1868     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
1869     case elfcpp::R_386_TLS_DESC_CALL:
1870     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
1871     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
1872     case elfcpp::R_386_TLS_IE:            // Initial-exec
1873     case elfcpp::R_386_TLS_IE_32:
1874     case elfcpp::R_386_TLS_GOTIE:
1875     case elfcpp::R_386_TLS_LE:            // Local-exec
1876     case elfcpp::R_386_TLS_LE_32:
1877       {
1878         const bool is_final = gsym->final_value_is_known();
1879         const tls::Tls_optimization optimized_type
1880             = Target_i386::optimize_tls_reloc(is_final, r_type);
1881         switch (r_type)
1882           {
1883           case elfcpp::R_386_TLS_GD:          // Global-dynamic
1884             if (optimized_type == tls::TLSOPT_NONE)
1885               {
1886                 // Create a pair of GOT entries for the module index and
1887                 // dtv-relative offset.
1888                 Output_data_got<32, false>* got
1889                     = target->got_section(symtab, layout);
1890                 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
1891                                              target->rel_dyn_section(layout),
1892                                              elfcpp::R_386_TLS_DTPMOD32,
1893                                              elfcpp::R_386_TLS_DTPOFF32);
1894               }
1895             else if (optimized_type == tls::TLSOPT_TO_IE)
1896               {
1897                 // Create a GOT entry for the tp-relative offset.
1898                 Output_data_got<32, false>* got
1899                     = target->got_section(symtab, layout);
1900                 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
1901                                          target->rel_dyn_section(layout),
1902                                          elfcpp::R_386_TLS_TPOFF);
1903               }
1904             else if (optimized_type != tls::TLSOPT_TO_LE)
1905               unsupported_reloc_global(object, r_type, gsym);
1906             break;
1907
1908           case elfcpp::R_386_TLS_GOTDESC:     // Global-dynamic (~oliva url)
1909             target->define_tls_base_symbol(symtab, layout);
1910             if (optimized_type == tls::TLSOPT_NONE)
1911               {
1912                 // Create a double GOT entry with an R_386_TLS_DESC
1913                 // reloc.  The R_386_TLS_DESC reloc is resolved
1914                 // lazily, so the GOT entry needs to be in an area in
1915                 // .got.plt, not .got.  Call got_section to make sure
1916                 // the section has been created.
1917                 target->got_section(symtab, layout);
1918                 Output_data_got<32, false>* got = target->got_tlsdesc_section();
1919                 Reloc_section* rt = target->rel_tls_desc_section(layout);
1920                 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC, rt,
1921                                              elfcpp::R_386_TLS_DESC, 0);
1922               }
1923             else if (optimized_type == tls::TLSOPT_TO_IE)
1924               {
1925                 // Create a GOT entry for the tp-relative offset.
1926                 Output_data_got<32, false>* got
1927                     = target->got_section(symtab, layout);
1928                 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
1929                                          target->rel_dyn_section(layout),
1930                                          elfcpp::R_386_TLS_TPOFF);
1931               }
1932             else if (optimized_type != tls::TLSOPT_TO_LE)
1933               unsupported_reloc_global(object, r_type, gsym);
1934             break;
1935
1936           case elfcpp::R_386_TLS_DESC_CALL:
1937             break;
1938
1939           case elfcpp::R_386_TLS_LDM:         // Local-dynamic
1940             if (optimized_type == tls::TLSOPT_NONE)
1941               {
1942                 // Create a GOT entry for the module index.
1943                 target->got_mod_index_entry(symtab, layout, object);
1944               }
1945             else if (optimized_type != tls::TLSOPT_TO_LE)
1946               unsupported_reloc_global(object, r_type, gsym);
1947             break;
1948
1949           case elfcpp::R_386_TLS_LDO_32:      // Alternate local-dynamic
1950             break;
1951
1952           case elfcpp::R_386_TLS_IE:          // Initial-exec
1953           case elfcpp::R_386_TLS_IE_32:
1954           case elfcpp::R_386_TLS_GOTIE:
1955             layout->set_has_static_tls();
1956             if (optimized_type == tls::TLSOPT_NONE)
1957               {
1958                 // For the R_386_TLS_IE relocation, we need to create a
1959                 // dynamic relocation when building a shared library.
1960                 if (r_type == elfcpp::R_386_TLS_IE
1961                     && parameters->options().shared())
1962                   {
1963                     Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1964                     rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1965                                                  output_section, object,
1966                                                  data_shndx,
1967                                                  reloc.get_r_offset());
1968                   }
1969                 // Create a GOT entry for the tp-relative offset.
1970                 Output_data_got<32, false>* got
1971                     = target->got_section(symtab, layout);
1972                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
1973                                            ? elfcpp::R_386_TLS_TPOFF32
1974                                            : elfcpp::R_386_TLS_TPOFF);
1975                 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
1976                                          ? GOT_TYPE_TLS_OFFSET
1977                                          : GOT_TYPE_TLS_NOFFSET);
1978                 got->add_global_with_rel(gsym, got_type,
1979                                          target->rel_dyn_section(layout),
1980                                          dyn_r_type);
1981               }
1982             else if (optimized_type != tls::TLSOPT_TO_LE)
1983               unsupported_reloc_global(object, r_type, gsym);
1984             break;
1985
1986           case elfcpp::R_386_TLS_LE:          // Local-exec
1987           case elfcpp::R_386_TLS_LE_32:
1988             layout->set_has_static_tls();
1989             if (parameters->options().shared())
1990               {
1991                 // We need to create a dynamic relocation.
1992                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
1993                                            ? elfcpp::R_386_TLS_TPOFF32
1994                                            : elfcpp::R_386_TLS_TPOFF);
1995                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1996                 rel_dyn->add_global(gsym, dyn_r_type, output_section, object,
1997                                     data_shndx, reloc.get_r_offset());
1998               }
1999             break;
2000
2001           default:
2002             gold_unreachable();
2003           }
2004       }
2005       break;
2006
2007     case elfcpp::R_386_32PLT:
2008     case elfcpp::R_386_TLS_GD_32:
2009     case elfcpp::R_386_TLS_GD_PUSH:
2010     case elfcpp::R_386_TLS_GD_CALL:
2011     case elfcpp::R_386_TLS_GD_POP:
2012     case elfcpp::R_386_TLS_LDM_32:
2013     case elfcpp::R_386_TLS_LDM_PUSH:
2014     case elfcpp::R_386_TLS_LDM_CALL:
2015     case elfcpp::R_386_TLS_LDM_POP:
2016     case elfcpp::R_386_USED_BY_INTEL_200:
2017     default:
2018       unsupported_reloc_global(object, r_type, gsym);
2019       break;
2020     }
2021 }
2022
2023 // Process relocations for gc.
2024
2025 void
2026 Target_i386::gc_process_relocs(Symbol_table* symtab,
2027                                Layout* layout,
2028                                Sized_relobj<32, false>* object,
2029                                unsigned int data_shndx,
2030                                unsigned int,
2031                                const unsigned char* prelocs,
2032                                size_t reloc_count,
2033                                Output_section* output_section,
2034                                bool needs_special_offset_handling,
2035                                size_t local_symbol_count,
2036                                const unsigned char* plocal_symbols)
2037 {
2038   gold::gc_process_relocs<32, false, Target_i386, elfcpp::SHT_REL,
2039                           Target_i386::Scan,
2040                           Target_i386::Relocatable_size_for_reloc>(
2041     symtab,
2042     layout,
2043     this,
2044     object,
2045     data_shndx,
2046     prelocs,
2047     reloc_count,
2048     output_section,
2049     needs_special_offset_handling,
2050     local_symbol_count,
2051     plocal_symbols);
2052 }
2053
2054 // Scan relocations for a section.
2055
2056 void
2057 Target_i386::scan_relocs(Symbol_table* symtab,
2058                          Layout* layout,
2059                          Sized_relobj<32, false>* object,
2060                          unsigned int data_shndx,
2061                          unsigned int sh_type,
2062                          const unsigned char* prelocs,
2063                          size_t reloc_count,
2064                          Output_section* output_section,
2065                          bool needs_special_offset_handling,
2066                          size_t local_symbol_count,
2067                          const unsigned char* plocal_symbols)
2068 {
2069   if (sh_type == elfcpp::SHT_RELA)
2070     {
2071       gold_error(_("%s: unsupported RELA reloc section"),
2072                  object->name().c_str());
2073       return;
2074     }
2075
2076   gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL,
2077                     Target_i386::Scan>(
2078     symtab,
2079     layout,
2080     this,
2081     object,
2082     data_shndx,
2083     prelocs,
2084     reloc_count,
2085     output_section,
2086     needs_special_offset_handling,
2087     local_symbol_count,
2088     plocal_symbols);
2089 }
2090
2091 // Finalize the sections.
2092
2093 void
2094 Target_i386::do_finalize_sections(
2095     Layout* layout,
2096     const Input_objects*,
2097     Symbol_table* symtab)
2098 {
2099   const Reloc_section* rel_plt = (this->plt_ == NULL
2100                                   ? NULL
2101                                   : this->plt_->rel_plt());
2102   layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
2103                                   this->rel_dyn_, true, false);
2104
2105   // Emit any relocs we saved in an attempt to avoid generating COPY
2106   // relocs.
2107   if (this->copy_relocs_.any_saved_relocs())
2108     this->copy_relocs_.emit(this->rel_dyn_section(layout));
2109
2110   // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
2111   // the .got.plt section.
2112   Symbol* sym = this->global_offset_table_;
2113   if (sym != NULL)
2114     {
2115       uint32_t data_size = this->got_plt_->current_data_size();
2116       symtab->get_sized_symbol<32>(sym)->set_symsize(data_size);
2117     }
2118 }
2119
2120 // Return whether a direct absolute static relocation needs to be applied.
2121 // In cases where Scan::local() or Scan::global() has created
2122 // a dynamic relocation other than R_386_RELATIVE, the addend
2123 // of the relocation is carried in the data, and we must not
2124 // apply the static relocation.
2125
2126 inline bool
2127 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol<32>* gsym,
2128                                                  unsigned int r_type,
2129                                                  bool is_32bit,
2130                                                  Output_section* output_section)
2131 {
2132   // If the output section is not allocated, then we didn't call
2133   // scan_relocs, we didn't create a dynamic reloc, and we must apply
2134   // the reloc here.
2135   if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
2136     return true;
2137
2138   int ref_flags = Scan::get_reference_flags(r_type);
2139
2140   // For local symbols, we will have created a non-RELATIVE dynamic
2141   // relocation only if (a) the output is position independent,
2142   // (b) the relocation is absolute (not pc- or segment-relative), and
2143   // (c) the relocation is not 32 bits wide.
2144   if (gsym == NULL)
2145     return !(parameters->options().output_is_position_independent()
2146              && (ref_flags & Symbol::ABSOLUTE_REF)
2147              && !is_32bit);
2148
2149   // For global symbols, we use the same helper routines used in the
2150   // scan pass.  If we did not create a dynamic relocation, or if we
2151   // created a RELATIVE dynamic relocation, we should apply the static
2152   // relocation.
2153   bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
2154   bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
2155                 && gsym->can_use_relative_reloc(ref_flags
2156                                                 & Symbol::FUNCTION_CALL);
2157   return !has_dyn || is_rel;
2158 }
2159
2160 // Perform a relocation.
2161
2162 inline bool
2163 Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
2164                                 Target_i386* target,
2165                                 Output_section* output_section,
2166                                 size_t relnum,
2167                                 const elfcpp::Rel<32, false>& rel,
2168                                 unsigned int r_type,
2169                                 const Sized_symbol<32>* gsym,
2170                                 const Symbol_value<32>* psymval,
2171                                 unsigned char* view,
2172                                 elfcpp::Elf_types<32>::Elf_Addr address,
2173                                 section_size_type view_size)
2174 {
2175   if (this->skip_call_tls_get_addr_)
2176     {
2177       if ((r_type != elfcpp::R_386_PLT32
2178            && r_type != elfcpp::R_386_PC32)
2179           || gsym == NULL
2180           || strcmp(gsym->name(), "___tls_get_addr") != 0)
2181         gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2182                                _("missing expected TLS relocation"));
2183       else
2184         {
2185           this->skip_call_tls_get_addr_ = false;
2186           return false;
2187         }
2188     }
2189
2190   const Sized_relobj<32, false>* object = relinfo->object;
2191
2192   // Pick the value to use for symbols defined in shared objects.
2193   Symbol_value<32> symval;
2194   if (gsym != NULL
2195       && gsym->type() == elfcpp::STT_GNU_IFUNC
2196       && r_type == elfcpp::R_386_32
2197       && gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type))
2198       && gsym->can_use_relative_reloc(false)
2199       && !gsym->is_from_dynobj()
2200       && !gsym->is_undefined()
2201       && !gsym->is_preemptible())
2202     {
2203       // In this case we are generating a R_386_IRELATIVE reloc.  We
2204       // want to use the real value of the symbol, not the PLT offset.
2205     }
2206   else if (gsym != NULL
2207            && gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
2208     {
2209       symval.set_output_value(target->plt_section()->address()
2210                               + gsym->plt_offset());
2211       psymval = &symval;
2212     }
2213   else if (gsym == NULL && psymval->is_ifunc_symbol())
2214     {
2215       unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2216       if (object->local_has_plt_offset(r_sym))
2217         {
2218           symval.set_output_value(target->plt_section()->address()
2219                                   + object->local_plt_offset(r_sym));
2220           psymval = &symval;
2221         }
2222     }
2223
2224   // Get the GOT offset if needed.
2225   // The GOT pointer points to the end of the GOT section.
2226   // We need to subtract the size of the GOT section to get
2227   // the actual offset to use in the relocation.
2228   bool have_got_offset = false;
2229   unsigned int got_offset = 0;
2230   switch (r_type)
2231     {
2232     case elfcpp::R_386_GOT32:
2233       if (gsym != NULL)
2234         {
2235           gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
2236           got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
2237                         - target->got_size());
2238         }
2239       else
2240         {
2241           unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2242           gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
2243           got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
2244                         - target->got_size());
2245         }
2246       have_got_offset = true;
2247       break;
2248
2249     default:
2250       break;
2251     }
2252
2253   switch (r_type)
2254     {
2255     case elfcpp::R_386_NONE:
2256     case elfcpp::R_386_GNU_VTINHERIT:
2257     case elfcpp::R_386_GNU_VTENTRY:
2258       break;
2259
2260     case elfcpp::R_386_32:
2261       if (should_apply_static_reloc(gsym, r_type, true, output_section))
2262         Relocate_functions<32, false>::rel32(view, object, psymval);
2263       break;
2264
2265     case elfcpp::R_386_PC32:
2266       if (should_apply_static_reloc(gsym, r_type, true, output_section))
2267         Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
2268       break;
2269
2270     case elfcpp::R_386_16:
2271       if (should_apply_static_reloc(gsym, r_type, false, output_section))
2272         Relocate_functions<32, false>::rel16(view, object, psymval);
2273       break;
2274
2275     case elfcpp::R_386_PC16:
2276       if (should_apply_static_reloc(gsym, r_type, false, output_section))
2277         Relocate_functions<32, false>::pcrel16(view, object, psymval, address);
2278       break;
2279
2280     case elfcpp::R_386_8:
2281       if (should_apply_static_reloc(gsym, r_type, false, output_section))
2282         Relocate_functions<32, false>::rel8(view, object, psymval);
2283       break;
2284
2285     case elfcpp::R_386_PC8:
2286       if (should_apply_static_reloc(gsym, r_type, false, output_section))
2287         Relocate_functions<32, false>::pcrel8(view, object, psymval, address);
2288       break;
2289
2290     case elfcpp::R_386_PLT32:
2291       gold_assert(gsym == NULL
2292                   || gsym->has_plt_offset()
2293                   || gsym->final_value_is_known()
2294                   || (gsym->is_defined()
2295                       && !gsym->is_from_dynobj()
2296                       && !gsym->is_preemptible()));
2297       Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
2298       break;
2299
2300     case elfcpp::R_386_GOT32:
2301       gold_assert(have_got_offset);
2302       Relocate_functions<32, false>::rel32(view, got_offset);
2303       break;
2304
2305     case elfcpp::R_386_GOTOFF:
2306       {
2307         elfcpp::Elf_types<32>::Elf_Addr value;
2308         value = (psymval->value(object, 0)
2309                  - target->got_plt_section()->address());
2310         Relocate_functions<32, false>::rel32(view, value);
2311       }
2312       break;
2313
2314     case elfcpp::R_386_GOTPC:
2315       {
2316         elfcpp::Elf_types<32>::Elf_Addr value;
2317         value = target->got_plt_section()->address();
2318         Relocate_functions<32, false>::pcrel32(view, value, address);
2319       }
2320       break;
2321
2322     case elfcpp::R_386_COPY:
2323     case elfcpp::R_386_GLOB_DAT:
2324     case elfcpp::R_386_JUMP_SLOT:
2325     case elfcpp::R_386_RELATIVE:
2326     case elfcpp::R_386_IRELATIVE:
2327       // These are outstanding tls relocs, which are unexpected when
2328       // linking.
2329     case elfcpp::R_386_TLS_TPOFF:
2330     case elfcpp::R_386_TLS_DTPMOD32:
2331     case elfcpp::R_386_TLS_DTPOFF32:
2332     case elfcpp::R_386_TLS_TPOFF32:
2333     case elfcpp::R_386_TLS_DESC:
2334       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2335                              _("unexpected reloc %u in object file"),
2336                              r_type);
2337       break;
2338
2339       // These are initial tls relocs, which are expected when
2340       // linking.
2341     case elfcpp::R_386_TLS_GD:             // Global-dynamic
2342     case elfcpp::R_386_TLS_GOTDESC:        // Global-dynamic (from ~oliva url)
2343     case elfcpp::R_386_TLS_DESC_CALL:
2344     case elfcpp::R_386_TLS_LDM:            // Local-dynamic
2345     case elfcpp::R_386_TLS_LDO_32:         // Alternate local-dynamic
2346     case elfcpp::R_386_TLS_IE:             // Initial-exec
2347     case elfcpp::R_386_TLS_IE_32:
2348     case elfcpp::R_386_TLS_GOTIE:
2349     case elfcpp::R_386_TLS_LE:             // Local-exec
2350     case elfcpp::R_386_TLS_LE_32:
2351       this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
2352                          view, address, view_size);
2353       break;
2354
2355     case elfcpp::R_386_32PLT:
2356     case elfcpp::R_386_TLS_GD_32:
2357     case elfcpp::R_386_TLS_GD_PUSH:
2358     case elfcpp::R_386_TLS_GD_CALL:
2359     case elfcpp::R_386_TLS_GD_POP:
2360     case elfcpp::R_386_TLS_LDM_32:
2361     case elfcpp::R_386_TLS_LDM_PUSH:
2362     case elfcpp::R_386_TLS_LDM_CALL:
2363     case elfcpp::R_386_TLS_LDM_POP:
2364     case elfcpp::R_386_USED_BY_INTEL_200:
2365     default:
2366       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2367                              _("unsupported reloc %u"),
2368                              r_type);
2369       break;
2370     }
2371
2372   return true;
2373 }
2374
2375 // Perform a TLS relocation.
2376
2377 inline void
2378 Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo,
2379                                     Target_i386* target,
2380                                     size_t relnum,
2381                                     const elfcpp::Rel<32, false>& rel,
2382                                     unsigned int r_type,
2383                                     const Sized_symbol<32>* gsym,
2384                                     const Symbol_value<32>* psymval,
2385                                     unsigned char* view,
2386                                     elfcpp::Elf_types<32>::Elf_Addr,
2387                                     section_size_type view_size)
2388 {
2389   Output_segment* tls_segment = relinfo->layout->tls_segment();
2390
2391   const Sized_relobj<32, false>* object = relinfo->object;
2392
2393   elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
2394
2395   const bool is_final = (gsym == NULL
2396                          ? !parameters->options().shared()
2397                          : gsym->final_value_is_known());
2398   const tls::Tls_optimization optimized_type
2399       = Target_i386::optimize_tls_reloc(is_final, r_type);
2400   switch (r_type)
2401     {
2402     case elfcpp::R_386_TLS_GD:           // Global-dynamic
2403       if (optimized_type == tls::TLSOPT_TO_LE)
2404         {
2405           gold_assert(tls_segment != NULL);
2406           this->tls_gd_to_le(relinfo, relnum, tls_segment,
2407                              rel, r_type, value, view,
2408                              view_size);
2409           break;
2410         }
2411       else
2412         {
2413           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
2414                                    ? GOT_TYPE_TLS_NOFFSET
2415                                    : GOT_TYPE_TLS_PAIR);
2416           unsigned int got_offset;
2417           if (gsym != NULL)
2418             {
2419               gold_assert(gsym->has_got_offset(got_type));
2420               got_offset = gsym->got_offset(got_type) - target->got_size();
2421             }
2422           else
2423             {
2424               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2425               gold_assert(object->local_has_got_offset(r_sym, got_type));
2426               got_offset = (object->local_got_offset(r_sym, got_type)
2427                             - target->got_size());
2428             }
2429           if (optimized_type == tls::TLSOPT_TO_IE)
2430             {
2431               gold_assert(tls_segment != NULL);
2432               this->tls_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
2433                                  got_offset, view, view_size);
2434               break;
2435             }
2436           else if (optimized_type == tls::TLSOPT_NONE)
2437             {
2438               // Relocate the field with the offset of the pair of GOT
2439               // entries.
2440               Relocate_functions<32, false>::rel32(view, got_offset);
2441               break;
2442             }
2443         }
2444       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2445                              _("unsupported reloc %u"),
2446                              r_type);
2447       break;
2448
2449     case elfcpp::R_386_TLS_GOTDESC:      // Global-dynamic (from ~oliva url)
2450     case elfcpp::R_386_TLS_DESC_CALL:
2451       this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
2452       if (optimized_type == tls::TLSOPT_TO_LE)
2453         {
2454           gold_assert(tls_segment != NULL);
2455           this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
2456                                   rel, r_type, value, view,
2457                                   view_size);
2458           break;
2459         }
2460       else
2461         {
2462           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
2463                                    ? GOT_TYPE_TLS_NOFFSET
2464                                    : GOT_TYPE_TLS_DESC);
2465           unsigned int got_offset = 0;
2466           if (r_type == elfcpp::R_386_TLS_GOTDESC
2467               && optimized_type == tls::TLSOPT_NONE)
2468             {
2469               // We created GOT entries in the .got.tlsdesc portion of
2470               // the .got.plt section, but the offset stored in the
2471               // symbol is the offset within .got.tlsdesc.
2472               got_offset = (target->got_size()
2473                             + target->got_plt_section()->data_size());
2474             }
2475           if (gsym != NULL)
2476             {
2477               gold_assert(gsym->has_got_offset(got_type));
2478               got_offset += gsym->got_offset(got_type) - target->got_size();
2479             }
2480           else
2481             {
2482               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2483               gold_assert(object->local_has_got_offset(r_sym, got_type));
2484               got_offset += (object->local_got_offset(r_sym, got_type)
2485                              - target->got_size());
2486             }
2487           if (optimized_type == tls::TLSOPT_TO_IE)
2488             {
2489               gold_assert(tls_segment != NULL);
2490               this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
2491                                       got_offset, view, view_size);
2492               break;
2493             }
2494           else if (optimized_type == tls::TLSOPT_NONE)
2495             {
2496               if (r_type == elfcpp::R_386_TLS_GOTDESC)
2497                 {
2498                   // Relocate the field with the offset of the pair of GOT
2499                   // entries.
2500                   Relocate_functions<32, false>::rel32(view, got_offset);
2501                 }
2502               break;
2503             }
2504         }
2505       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2506                              _("unsupported reloc %u"),
2507                              r_type);
2508       break;
2509
2510     case elfcpp::R_386_TLS_LDM:          // Local-dynamic
2511       if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN)
2512         {
2513           gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2514                                  _("both SUN and GNU model "
2515                                    "TLS relocations"));
2516           break;
2517         }
2518       this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
2519       if (optimized_type == tls::TLSOPT_TO_LE)
2520         {
2521           gold_assert(tls_segment != NULL);
2522           this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, r_type,
2523                              value, view, view_size);
2524           break;
2525         }
2526       else if (optimized_type == tls::TLSOPT_NONE)
2527         {
2528           // Relocate the field with the offset of the GOT entry for
2529           // the module index.
2530           unsigned int got_offset;
2531           got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
2532                         - target->got_size());
2533           Relocate_functions<32, false>::rel32(view, got_offset);
2534           break;
2535         }
2536       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2537                              _("unsupported reloc %u"),
2538                              r_type);
2539       break;
2540
2541     case elfcpp::R_386_TLS_LDO_32:       // Alternate local-dynamic
2542       if (optimized_type == tls::TLSOPT_TO_LE)
2543         {
2544           // This reloc can appear in debugging sections, in which
2545           // case we must not convert to local-exec.  We decide what
2546           // to do based on whether the section is marked as
2547           // containing executable code.  That is what the GNU linker
2548           // does as well.
2549           elfcpp::Shdr<32, false> shdr(relinfo->data_shdr);
2550           if ((shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0)
2551             {
2552               gold_assert(tls_segment != NULL);
2553               value -= tls_segment->memsz();
2554             }
2555         }
2556       Relocate_functions<32, false>::rel32(view, value);
2557       break;
2558
2559     case elfcpp::R_386_TLS_IE:           // Initial-exec
2560     case elfcpp::R_386_TLS_GOTIE:
2561     case elfcpp::R_386_TLS_IE_32:
2562       if (optimized_type == tls::TLSOPT_TO_LE)
2563         {
2564           gold_assert(tls_segment != NULL);
2565           Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
2566                                               rel, r_type, value, view,
2567                                               view_size);
2568           break;
2569         }
2570       else if (optimized_type == tls::TLSOPT_NONE)
2571         {
2572           // Relocate the field with the offset of the GOT entry for
2573           // the tp-relative offset of the symbol.
2574           unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
2575                                    ? GOT_TYPE_TLS_OFFSET
2576                                    : GOT_TYPE_TLS_NOFFSET);
2577           unsigned int got_offset;
2578           if (gsym != NULL)
2579             {
2580               gold_assert(gsym->has_got_offset(got_type));
2581               got_offset = gsym->got_offset(got_type);
2582             }
2583           else
2584             {
2585               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2586               gold_assert(object->local_has_got_offset(r_sym, got_type));
2587               got_offset = object->local_got_offset(r_sym, got_type);
2588             }
2589           // For the R_386_TLS_IE relocation, we need to apply the
2590           // absolute address of the GOT entry.
2591           if (r_type == elfcpp::R_386_TLS_IE)
2592             got_offset += target->got_plt_section()->address();
2593           // All GOT offsets are relative to the end of the GOT.
2594           got_offset -= target->got_size();
2595           Relocate_functions<32, false>::rel32(view, got_offset);
2596           break;
2597         }
2598       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2599                              _("unsupported reloc %u"),
2600                              r_type);
2601       break;
2602
2603     case elfcpp::R_386_TLS_LE:           // Local-exec
2604       // If we're creating a shared library, a dynamic relocation will
2605       // have been created for this location, so do not apply it now.
2606       if (!parameters->options().shared())
2607         {
2608           gold_assert(tls_segment != NULL);
2609           value -= tls_segment->memsz();
2610           Relocate_functions<32, false>::rel32(view, value);
2611         }
2612       break;
2613
2614     case elfcpp::R_386_TLS_LE_32:
2615       // If we're creating a shared library, a dynamic relocation will
2616       // have been created for this location, so do not apply it now.
2617       if (!parameters->options().shared())
2618         {
2619           gold_assert(tls_segment != NULL);
2620           value = tls_segment->memsz() - value;
2621           Relocate_functions<32, false>::rel32(view, value);
2622         }
2623       break;
2624     }
2625 }
2626
2627 // Do a relocation in which we convert a TLS General-Dynamic to a
2628 // Local-Exec.
2629
2630 inline void
2631 Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo,
2632                                     size_t relnum,
2633                                     Output_segment* tls_segment,
2634                                     const elfcpp::Rel<32, false>& rel,
2635                                     unsigned int,
2636                                     elfcpp::Elf_types<32>::Elf_Addr value,
2637                                     unsigned char* view,
2638                                     section_size_type view_size)
2639 {
2640   // leal foo(,%reg,1),%eax; call ___tls_get_addr
2641   //  ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2642   // leal foo(%reg),%eax; call ___tls_get_addr
2643   //  ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2644
2645   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2646   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2647
2648   unsigned char op1 = view[-1];
2649   unsigned char op2 = view[-2];
2650
2651   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2652                  op2 == 0x8d || op2 == 0x04);
2653   tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2654
2655   int roff = 5;
2656
2657   if (op2 == 0x04)
2658     {
2659       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
2660       tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
2661       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2662                      ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
2663       memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2664     }
2665   else
2666     {
2667       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2668                      (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
2669       if (rel.get_r_offset() + 9 < view_size
2670           && view[9] == 0x90)
2671         {
2672           // There is a trailing nop.  Use the size byte subl.
2673           memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2674           roff = 6;
2675         }
2676       else
2677         {
2678           // Use the five byte subl.
2679           memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2680         }
2681     }
2682
2683   value = tls_segment->memsz() - value;
2684   Relocate_functions<32, false>::rel32(view + roff, value);
2685
2686   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2687   // We can skip it.
2688   this->skip_call_tls_get_addr_ = true;
2689 }
2690
2691 // Do a relocation in which we convert a TLS General-Dynamic to an
2692 // Initial-Exec.
2693
2694 inline void
2695 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info<32, false>* relinfo,
2696                                     size_t relnum,
2697                                     Output_segment*,
2698                                     const elfcpp::Rel<32, false>& rel,
2699                                     unsigned int,
2700                                     elfcpp::Elf_types<32>::Elf_Addr value,
2701                                     unsigned char* view,
2702                                     section_size_type view_size)
2703 {
2704   // leal foo(,%ebx,1),%eax; call ___tls_get_addr
2705   //  ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
2706
2707   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2708   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2709
2710   unsigned char op1 = view[-1];
2711   unsigned char op2 = view[-2];
2712
2713   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2714                  op2 == 0x8d || op2 == 0x04);
2715   tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2716
2717   int roff = 5;
2718
2719   // FIXME: For now, support only the first (SIB) form.
2720   tls::check_tls(relinfo, relnum, rel.get_r_offset(), op2 == 0x04);
2721
2722   if (op2 == 0x04)
2723     {
2724       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
2725       tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
2726       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2727                      ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
2728       memcpy(view - 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
2729     }
2730   else
2731     {
2732       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2733                      (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
2734       if (rel.get_r_offset() + 9 < view_size
2735           && view[9] == 0x90)
2736         {
2737           // FIXME: This is not the right instruction sequence.
2738           // There is a trailing nop.  Use the size byte subl.
2739           memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2740           roff = 6;
2741         }
2742       else
2743         {
2744           // FIXME: This is not the right instruction sequence.
2745           // Use the five byte subl.
2746           memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2747         }
2748     }
2749
2750   Relocate_functions<32, false>::rel32(view + roff, value);
2751
2752   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2753   // We can skip it.
2754   this->skip_call_tls_get_addr_ = true;
2755 }
2756
2757 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2758 // General-Dynamic to a Local-Exec.
2759
2760 inline void
2761 Target_i386::Relocate::tls_desc_gd_to_le(
2762     const Relocate_info<32, false>* relinfo,
2763     size_t relnum,
2764     Output_segment* tls_segment,
2765     const elfcpp::Rel<32, false>& rel,
2766     unsigned int r_type,
2767     elfcpp::Elf_types<32>::Elf_Addr value,
2768     unsigned char* view,
2769     section_size_type view_size)
2770 {
2771   if (r_type == elfcpp::R_386_TLS_GOTDESC)
2772     {
2773       // leal foo@TLSDESC(%ebx), %eax
2774       // ==> leal foo@NTPOFF, %eax
2775       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2776       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2777       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2778                      view[-2] == 0x8d && view[-1] == 0x83);
2779       view[-1] = 0x05;
2780       value -= tls_segment->memsz();
2781       Relocate_functions<32, false>::rel32(view, value);
2782     }
2783   else
2784     {
2785       // call *foo@TLSCALL(%eax)
2786       // ==> nop; nop
2787       gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
2788       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
2789       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2790                      view[0] == 0xff && view[1] == 0x10);
2791       view[0] = 0x66;
2792       view[1] = 0x90;
2793     }
2794 }
2795
2796 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2797 // General-Dynamic to an Initial-Exec.
2798
2799 inline void
2800 Target_i386::Relocate::tls_desc_gd_to_ie(
2801     const Relocate_info<32, false>* relinfo,
2802     size_t relnum,
2803     Output_segment*,
2804     const elfcpp::Rel<32, false>& rel,
2805     unsigned int r_type,
2806     elfcpp::Elf_types<32>::Elf_Addr value,
2807     unsigned char* view,
2808     section_size_type view_size)
2809 {
2810   if (r_type == elfcpp::R_386_TLS_GOTDESC)
2811     {
2812       // leal foo@TLSDESC(%ebx), %eax
2813       // ==> movl foo@GOTNTPOFF(%ebx), %eax
2814       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2815       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2816       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2817                      view[-2] == 0x8d && view[-1] == 0x83);
2818       view[-2] = 0x8b;
2819       Relocate_functions<32, false>::rel32(view, value);
2820     }
2821   else
2822     {
2823       // call *foo@TLSCALL(%eax)
2824       // ==> nop; nop
2825       gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
2826       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
2827       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2828                      view[0] == 0xff && view[1] == 0x10);
2829       view[0] = 0x66;
2830       view[1] = 0x90;
2831     }
2832 }
2833
2834 // Do a relocation in which we convert a TLS Local-Dynamic to a
2835 // Local-Exec.
2836
2837 inline void
2838 Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo,
2839                                     size_t relnum,
2840                                     Output_segment*,
2841                                     const elfcpp::Rel<32, false>& rel,
2842                                     unsigned int,
2843                                     elfcpp::Elf_types<32>::Elf_Addr,
2844                                     unsigned char* view,
2845                                     section_size_type view_size)
2846 {
2847   // leal foo(%reg), %eax; call ___tls_get_addr
2848   // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
2849
2850   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2851   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2852
2853   // FIXME: Does this test really always pass?
2854   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2855                  view[-2] == 0x8d && view[-1] == 0x83);
2856
2857   tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2858
2859   memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
2860
2861   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2862   // We can skip it.
2863   this->skip_call_tls_get_addr_ = true;
2864 }
2865
2866 // Do a relocation in which we convert a TLS Initial-Exec to a
2867 // Local-Exec.
2868
2869 inline void
2870 Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo,
2871                                     size_t relnum,
2872                                     Output_segment* tls_segment,
2873                                     const elfcpp::Rel<32, false>& rel,
2874                                     unsigned int r_type,
2875                                     elfcpp::Elf_types<32>::Elf_Addr value,
2876                                     unsigned char* view,
2877                                     section_size_type view_size)
2878 {
2879   // We have to actually change the instructions, which means that we
2880   // need to examine the opcodes to figure out which instruction we
2881   // are looking at.
2882   if (r_type == elfcpp::R_386_TLS_IE)
2883     {
2884       // movl %gs:XX,%eax  ==>  movl $YY,%eax
2885       // movl %gs:XX,%reg  ==>  movl $YY,%reg
2886       // addl %gs:XX,%reg  ==>  addl $YY,%reg
2887       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -1);
2888       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2889
2890       unsigned char op1 = view[-1];
2891       if (op1 == 0xa1)
2892         {
2893           // movl XX,%eax  ==>  movl $YY,%eax
2894           view[-1] = 0xb8;
2895         }
2896       else
2897         {
2898           tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2899
2900           unsigned char op2 = view[-2];
2901           if (op2 == 0x8b)
2902             {
2903               // movl XX,%reg  ==>  movl $YY,%reg
2904               tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2905                              (op1 & 0xc7) == 0x05);
2906               view[-2] = 0xc7;
2907               view[-1] = 0xc0 | ((op1 >> 3) & 7);
2908             }
2909           else if (op2 == 0x03)
2910             {
2911               // addl XX,%reg  ==>  addl $YY,%reg
2912               tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2913                              (op1 & 0xc7) == 0x05);
2914               view[-2] = 0x81;
2915               view[-1] = 0xc0 | ((op1 >> 3) & 7);
2916             }
2917           else
2918             tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
2919         }
2920     }
2921   else
2922     {
2923       // subl %gs:XX(%reg1),%reg2  ==>  subl $YY,%reg2
2924       // movl %gs:XX(%reg1),%reg2  ==>  movl $YY,%reg2
2925       // addl %gs:XX(%reg1),%reg2  ==>  addl $YY,$reg2
2926       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2927       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2928
2929       unsigned char op1 = view[-1];
2930       unsigned char op2 = view[-2];
2931       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2932                      (op1 & 0xc0) == 0x80 && (op1 & 7) != 4);
2933       if (op2 == 0x8b)
2934         {
2935           // movl %gs:XX(%reg1),%reg2  ==>  movl $YY,%reg2
2936           view[-2] = 0xc7;
2937           view[-1] = 0xc0 | ((op1 >> 3) & 7);
2938         }
2939       else if (op2 == 0x2b)
2940         {
2941           // subl %gs:XX(%reg1),%reg2  ==>  subl $YY,%reg2
2942           view[-2] = 0x81;
2943           view[-1] = 0xe8 | ((op1 >> 3) & 7);
2944         }
2945       else if (op2 == 0x03)
2946         {
2947           // addl %gs:XX(%reg1),%reg2  ==>  addl $YY,$reg2
2948           view[-2] = 0x81;
2949           view[-1] = 0xc0 | ((op1 >> 3) & 7);
2950         }
2951       else
2952         tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
2953     }
2954
2955   value = tls_segment->memsz() - value;
2956   if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE)
2957     value = - value;
2958
2959   Relocate_functions<32, false>::rel32(view, value);
2960 }
2961
2962 // Relocate section data.
2963
2964 void
2965 Target_i386::relocate_section(const Relocate_info<32, false>* relinfo,
2966                               unsigned int sh_type,
2967                               const unsigned char* prelocs,
2968                               size_t reloc_count,
2969                               Output_section* output_section,
2970                               bool needs_special_offset_handling,
2971                               unsigned char* view,
2972                               elfcpp::Elf_types<32>::Elf_Addr address,
2973                               section_size_type view_size,
2974                               const Reloc_symbol_changes* reloc_symbol_changes)
2975 {
2976   gold_assert(sh_type == elfcpp::SHT_REL);
2977
2978   gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL,
2979                          Target_i386::Relocate>(
2980     relinfo,
2981     this,
2982     prelocs,
2983     reloc_count,
2984     output_section,
2985     needs_special_offset_handling,
2986     view,
2987     address,
2988     view_size,
2989     reloc_symbol_changes);
2990 }
2991
2992 // Return the size of a relocation while scanning during a relocatable
2993 // link.
2994
2995 unsigned int
2996 Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
2997     unsigned int r_type,
2998     Relobj* object)
2999 {
3000   switch (r_type)
3001     {
3002     case elfcpp::R_386_NONE:
3003     case elfcpp::R_386_GNU_VTINHERIT:
3004     case elfcpp::R_386_GNU_VTENTRY:
3005     case elfcpp::R_386_TLS_GD:            // Global-dynamic
3006     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
3007     case elfcpp::R_386_TLS_DESC_CALL:
3008     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
3009     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
3010     case elfcpp::R_386_TLS_IE:            // Initial-exec
3011     case elfcpp::R_386_TLS_IE_32:
3012     case elfcpp::R_386_TLS_GOTIE:
3013     case elfcpp::R_386_TLS_LE:            // Local-exec
3014     case elfcpp::R_386_TLS_LE_32:
3015       return 0;
3016
3017     case elfcpp::R_386_32:
3018     case elfcpp::R_386_PC32:
3019     case elfcpp::R_386_GOT32:
3020     case elfcpp::R_386_PLT32:
3021     case elfcpp::R_386_GOTOFF:
3022     case elfcpp::R_386_GOTPC:
3023      return 4;
3024
3025     case elfcpp::R_386_16:
3026     case elfcpp::R_386_PC16:
3027       return 2;
3028
3029     case elfcpp::R_386_8:
3030     case elfcpp::R_386_PC8:
3031       return 1;
3032
3033       // These are relocations which should only be seen by the
3034       // dynamic linker, and should never be seen here.
3035     case elfcpp::R_386_COPY:
3036     case elfcpp::R_386_GLOB_DAT:
3037     case elfcpp::R_386_JUMP_SLOT:
3038     case elfcpp::R_386_RELATIVE:
3039     case elfcpp::R_386_IRELATIVE:
3040     case elfcpp::R_386_TLS_TPOFF:
3041     case elfcpp::R_386_TLS_DTPMOD32:
3042     case elfcpp::R_386_TLS_DTPOFF32:
3043     case elfcpp::R_386_TLS_TPOFF32:
3044     case elfcpp::R_386_TLS_DESC:
3045       object->error(_("unexpected reloc %u in object file"), r_type);
3046       return 0;
3047
3048     case elfcpp::R_386_32PLT:
3049     case elfcpp::R_386_TLS_GD_32:
3050     case elfcpp::R_386_TLS_GD_PUSH:
3051     case elfcpp::R_386_TLS_GD_CALL:
3052     case elfcpp::R_386_TLS_GD_POP:
3053     case elfcpp::R_386_TLS_LDM_32:
3054     case elfcpp::R_386_TLS_LDM_PUSH:
3055     case elfcpp::R_386_TLS_LDM_CALL:
3056     case elfcpp::R_386_TLS_LDM_POP:
3057     case elfcpp::R_386_USED_BY_INTEL_200:
3058     default:
3059       object->error(_("unsupported reloc %u in object file"), r_type);
3060       return 0;
3061     }
3062 }
3063
3064 // Scan the relocs during a relocatable link.
3065
3066 void
3067 Target_i386::scan_relocatable_relocs(Symbol_table* symtab,
3068                                      Layout* layout,
3069                                      Sized_relobj<32, false>* object,
3070                                      unsigned int data_shndx,
3071                                      unsigned int sh_type,
3072                                      const unsigned char* prelocs,
3073                                      size_t reloc_count,
3074                                      Output_section* output_section,
3075                                      bool needs_special_offset_handling,
3076                                      size_t local_symbol_count,
3077                                      const unsigned char* plocal_symbols,
3078                                      Relocatable_relocs* rr)
3079 {
3080   gold_assert(sh_type == elfcpp::SHT_REL);
3081
3082   typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_REL,
3083     Relocatable_size_for_reloc> Scan_relocatable_relocs;
3084
3085   gold::scan_relocatable_relocs<32, false, elfcpp::SHT_REL,
3086       Scan_relocatable_relocs>(
3087     symtab,
3088     layout,
3089     object,
3090     data_shndx,
3091     prelocs,
3092     reloc_count,
3093     output_section,
3094     needs_special_offset_handling,
3095     local_symbol_count,
3096     plocal_symbols,
3097     rr);
3098 }
3099
3100 // Relocate a section during a relocatable link.
3101
3102 void
3103 Target_i386::relocate_for_relocatable(
3104     const Relocate_info<32, false>* relinfo,
3105     unsigned int sh_type,
3106     const unsigned char* prelocs,
3107     size_t reloc_count,
3108     Output_section* output_section,
3109     off_t offset_in_output_section,
3110     const Relocatable_relocs* rr,
3111     unsigned char* view,
3112     elfcpp::Elf_types<32>::Elf_Addr view_address,
3113     section_size_type view_size,
3114     unsigned char* reloc_view,
3115     section_size_type reloc_view_size)
3116 {
3117   gold_assert(sh_type == elfcpp::SHT_REL);
3118
3119   gold::relocate_for_relocatable<32, false, elfcpp::SHT_REL>(
3120     relinfo,
3121     prelocs,
3122     reloc_count,
3123     output_section,
3124     offset_in_output_section,
3125     rr,
3126     view,
3127     view_address,
3128     view_size,
3129     reloc_view,
3130     reloc_view_size);
3131 }
3132
3133 // Return the value to use for a dynamic which requires special
3134 // treatment.  This is how we support equality comparisons of function
3135 // pointers across shared library boundaries, as described in the
3136 // processor specific ABI supplement.
3137
3138 uint64_t
3139 Target_i386::do_dynsym_value(const Symbol* gsym) const
3140 {
3141   gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
3142   return this->plt_section()->address() + gsym->plt_offset();
3143 }
3144
3145 // Return a string used to fill a code section with nops to take up
3146 // the specified length.
3147
3148 std::string
3149 Target_i386::do_code_fill(section_size_type length) const
3150 {
3151   if (length >= 16)
3152     {
3153       // Build a jmp instruction to skip over the bytes.
3154       unsigned char jmp[5];
3155       jmp[0] = 0xe9;
3156       elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
3157       return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
3158               + std::string(length - 5, '\0'));
3159     }
3160
3161   // Nop sequences of various lengths.
3162   const char nop1[1] = { 0x90 };                   // nop
3163   const char nop2[2] = { 0x66, 0x90 };             // xchg %ax %ax
3164   const char nop3[3] = { 0x8d, 0x76, 0x00 };       // leal 0(%esi),%esi
3165   const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00};  // leal 0(%esi,1),%esi
3166   const char nop5[5] = { 0x90, 0x8d, 0x74, 0x26,   // nop
3167                          0x00 };                   // leal 0(%esi,1),%esi
3168   const char nop6[6] = { 0x8d, 0xb6, 0x00, 0x00,   // leal 0L(%esi),%esi
3169                          0x00, 0x00 };
3170   const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00,   // leal 0L(%esi,1),%esi
3171                          0x00, 0x00, 0x00 };
3172   const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26,   // nop
3173                          0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
3174   const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc,   // movl %esi,%esi
3175                          0x27, 0x00, 0x00, 0x00,   // leal 0L(%edi,1),%edi
3176                          0x00 };
3177   const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
3178                            0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
3179                            0x00, 0x00 };
3180   const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
3181                            0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
3182                            0x00, 0x00, 0x00 };
3183   const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
3184                            0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
3185                            0x00, 0x00, 0x00, 0x00 };
3186   const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
3187                            0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
3188                            0x27, 0x00, 0x00, 0x00,
3189                            0x00 };
3190   const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
3191                            0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
3192                            0xbc, 0x27, 0x00, 0x00,
3193                            0x00, 0x00 };
3194   const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
3195                            0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
3196                            0x90, 0x90, 0x90, 0x90,
3197                            0x90, 0x90, 0x90 };
3198
3199   const char* nops[16] = {
3200     NULL,
3201     nop1, nop2, nop3, nop4, nop5, nop6, nop7,
3202     nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
3203   };
3204
3205   return std::string(nops[length], length);
3206 }
3207
3208 // Return whether SYM should be treated as a call to a non-split
3209 // function.  We don't want that to be true of a call to a
3210 // get_pc_thunk function.
3211
3212 bool
3213 Target_i386::do_is_call_to_non_split(const Symbol* sym, unsigned int) const
3214 {
3215   return (sym->type() == elfcpp::STT_FUNC
3216           && !is_prefix_of("__i686.get_pc_thunk.", sym->name()));
3217 }
3218
3219 // FNOFFSET in section SHNDX in OBJECT is the start of a function
3220 // compiled with -fsplit-stack.  The function calls non-split-stack
3221 // code.  We have to change the function so that it always ensures
3222 // that it has enough stack space to run some random function.
3223
3224 void
3225 Target_i386::do_calls_non_split(Relobj* object, unsigned int shndx,
3226                                 section_offset_type fnoffset,
3227                                 section_size_type fnsize,
3228                                 unsigned char* view,
3229                                 section_size_type view_size,
3230                                 std::string* from,
3231                                 std::string* to) const
3232 {
3233   // The function starts with a comparison of the stack pointer and a
3234   // field in the TCB.  This is followed by a jump.
3235
3236   // cmp %gs:NN,%esp
3237   if (this->match_view(view, view_size, fnoffset, "\x65\x3b\x25", 3)
3238       && fnsize > 7)
3239     {
3240       // We will call __morestack if the carry flag is set after this
3241       // comparison.  We turn the comparison into an stc instruction
3242       // and some nops.
3243       view[fnoffset] = '\xf9';
3244       this->set_view_to_nop(view, view_size, fnoffset + 1, 6);
3245     }
3246   // lea NN(%esp),%ecx
3247   // lea NN(%esp),%edx
3248   else if ((this->match_view(view, view_size, fnoffset, "\x8d\x8c\x24", 3)
3249             || this->match_view(view, view_size, fnoffset, "\x8d\x94\x24", 3))
3250            && fnsize > 7)
3251     {
3252       // This is loading an offset from the stack pointer for a
3253       // comparison.  The offset is negative, so we decrease the
3254       // offset by the amount of space we need for the stack.  This
3255       // means we will avoid calling __morestack if there happens to
3256       // be plenty of space on the stack already.
3257       unsigned char* pval = view + fnoffset + 3;
3258       uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
3259       val -= parameters->options().split_stack_adjust_size();
3260       elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
3261     }
3262   else
3263     {
3264       if (!object->has_no_split_stack())
3265         object->error(_("failed to match split-stack sequence at "
3266                         "section %u offset %0zx"),
3267                       shndx, static_cast<size_t>(fnoffset));
3268       return;
3269     }
3270
3271   // We have to change the function so that it calls
3272   // __morestack_non_split instead of __morestack.  The former will
3273   // allocate additional stack space.
3274   *from = "__morestack";
3275   *to = "__morestack_non_split";
3276 }
3277
3278 // The selector for i386 object files.
3279
3280 class Target_selector_i386 : public Target_selector_freebsd
3281 {
3282 public:
3283   Target_selector_i386()
3284     : Target_selector_freebsd(elfcpp::EM_386, 32, false,
3285                               "elf32-i386", "elf32-i386-freebsd")
3286   { }
3287
3288   Target*
3289   do_instantiate_target()
3290   { return new Target_i386(); }
3291 };
3292
3293 Target_selector_i386 target_selector_i386;
3294
3295 } // End anonymous namespace.