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