gold/i386.cc

   1 // i386.cc -- i386 target support for gold.
   2
   3 // Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
   4 // Written by Ian Lance Taylor <iant@google.com>.
   5
   6 // This file is part of gold.
   7
   8 // This program is free software; you can redistribute it and/or modify
   9 // it under the terms of the GNU General Public License as published by
  10 // the Free Software Foundation; either version 3 of the License, or
  11 // (at your option) any later version.
  12
  13 // This program is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17
  18 // You should have received a copy of the GNU General Public License
  19 // along with this program; if not, write to the Free Software
  20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  21 // MA 02110-1301, USA.
  22
  23 #include "gold.h"
  24
  25 #include <cstring>
  26
  27 #include "elfcpp.h"
  28 #include "parameters.h"
  29 #include "reloc.h"
  30 #include "i386.h"
  31 #include "object.h"
  32 #include "symtab.h"
  33 #include "layout.h"
  34 #include "output.h"
  35 #include "copy-relocs.h"
  36 #include "target.h"
  37 #include "target-reloc.h"
  38 #include "target-select.h"
  39 #include "tls.h"
  40 #include "freebsd.h"
  41 #include "gc.h"
  42
  43 namespace
  44 {
  45
  46 using namespace gold;
  47
  48 class Output_data_plt_i386;
  49
  50 // The i386 target class.
  51 // TLS info comes from
  52 //   http://people.redhat.com/drepper/tls.pdf
  53 //   http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
  54
  55 class Target_i386 : public Target_freebsd<32, false>
  56 {
  57  public:
  58   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
  59
  60   Target_i386()
  61     : Target_freebsd<32, false>(&i386_info),
  62       got_(NULL), plt_(NULL), got_plt_(NULL), global_offset_table_(NULL),
  63       rel_dyn_(NULL), copy_relocs_(elfcpp::R_386_COPY), dynbss_(NULL),
  64       got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
  65   { }
  66
  67   inline bool
  68   can_check_for_function_pointers() const
  69   { return true; }
  70
  71   // Process the relocations to determine unreferenced sections for
  72   // garbage collection.
  73   void
  74   gc_process_relocs(Symbol_table* symtab,
  75                     Layout* layout,
  76                     Sized_relobj<32, false>* object,
  77                     unsigned int data_shndx,
  78                     unsigned int sh_type,
  79                     const unsigned char* prelocs,
  80                     size_t reloc_count,
  81                     Output_section* output_section,
  82                     bool needs_special_offset_handling,
  83                     size_t local_symbol_count,
  84                     const unsigned char* plocal_symbols);
  85
  86   // Scan the relocations to look for symbol adjustments.
  87   void
  88   scan_relocs(Symbol_table* symtab,
  89               Layout* layout,
  90               Sized_relobj<32, false>* object,
  91               unsigned int data_shndx,
  92               unsigned int sh_type,
  93               const unsigned char* prelocs,
  94               size_t reloc_count,
  95               Output_section* output_section,
  96               bool needs_special_offset_handling,
  97               size_t local_symbol_count,
  98               const unsigned char* plocal_symbols);
  99
 100   // Finalize the sections.
 101   void
 102   do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
 103
 104   // Return the value to use for a dynamic which requires special
 105   // treatment.
 106   uint64_t
 107   do_dynsym_value(const Symbol*) const;
 108
 109   // Relocate a section.
 110   void
 111   relocate_section(const Relocate_info<32, false>*,
 112                    unsigned int sh_type,
 113                    const unsigned char* prelocs,
 114                    size_t reloc_count,
 115                    Output_section* output_section,
 116                    bool needs_special_offset_handling,
 117                    unsigned char* view,
 118                    elfcpp::Elf_types<32>::Elf_Addr view_address,
 119                    section_size_type view_size,
 120                    const Reloc_symbol_changes*);
 121
 122   // Scan the relocs during a relocatable link.
 123   void
 124   scan_relocatable_relocs(Symbol_table* symtab,
 125                           Layout* layout,
 126                           Sized_relobj<32, false>* object,
 127                           unsigned int data_shndx,
 128                           unsigned int sh_type,
 129                           const unsigned char* prelocs,
 130                           size_t reloc_count,
 131                           Output_section* output_section,
 132                           bool needs_special_offset_handling,
 133                           size_t local_symbol_count,
 134                           const unsigned char* plocal_symbols,
 135                           Relocatable_relocs*);
 136
 137   // Relocate a section during a relocatable link.
 138   void
 139   relocate_for_relocatable(const Relocate_info<32, false>*,
 140                            unsigned int sh_type,
 141                            const unsigned char* prelocs,
 142                            size_t reloc_count,
 143                            Output_section* output_section,
 144                            off_t offset_in_output_section,
 145                            const Relocatable_relocs*,
 146                            unsigned char* view,
 147                            elfcpp::Elf_types<32>::Elf_Addr view_address,
 148                            section_size_type view_size,
 149                            unsigned char* reloc_view,
 150                            section_size_type reloc_view_size);
 151
 152   // Return a string used to fill a code section with nops.
 153   std::string
 154   do_code_fill(section_size_type length) const;
 155
 156   // Return whether SYM is defined by the ABI.
 157   bool
 158   do_is_defined_by_abi(const Symbol* sym) const
 159   { return strcmp(sym->name(), "___tls_get_addr") == 0; }
 160
 161   // Return whether a symbol name implies a local label.  The UnixWare
 162   // 2.1 cc generates temporary symbols that start with .X, so we
 163   // recognize them here.  FIXME: do other SVR4 compilers also use .X?.
 164   // If so, we should move the .X recognition into
 165   // Target::do_is_local_label_name.
 166   bool
 167   do_is_local_label_name(const char* name) const
 168   {
 169     if (name[0] == '.' && name[1] == 'X')
 170       return true;
 171     return Target::do_is_local_label_name(name);
 172   }
 173
 174   // Return whether SYM is call to a non-split function.
 175   bool
 176   do_is_call_to_non_split(const Symbol* sym, unsigned int) const;
 177
 178   // Adjust -fstack-split code which calls non-stack-split code.
 179   void
 180   do_calls_non_split(Relobj* object, unsigned int shndx,
 181                      section_offset_type fnoffset, section_size_type fnsize,
 182                      unsigned char* view, section_size_type view_size,
 183                      std::string* from, std::string* to) const;
 184
 185   // Return the size of the GOT section.
 186   section_size_type
 187   got_size()
 188   {
 189     gold_assert(this->got_ != NULL);
 190     return this->got_->data_size();
 191   }
 192
 193  private:
 194   // The class which scans relocations.
 195   struct Scan
 196   {
 197     inline void
 198     local(Symbol_table* symtab, Layout* layout, Target_i386* target,
 199           Sized_relobj<32, false>* object,
 200           unsigned int data_shndx,
 201           Output_section* output_section,
 202           const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
 203           const elfcpp::Sym<32, false>& lsym);
 204
 205     inline void
 206     global(Symbol_table* symtab, Layout* layout, Target_i386* target,
 207            Sized_relobj<32, false>* object,
 208            unsigned int data_shndx,
 209            Output_section* output_section,
 210            const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
 211            Symbol* gsym);
 212
 213     inline bool
 214     local_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
 215                                         Target_i386* target,
 216                                         Sized_relobj<32, false>* object,
 217                                         unsigned int data_shndx,
 218                                         Output_section* output_section,
 219                                         const elfcpp::Rel<32, false>& reloc,
 220                                         unsigned int r_type,
 221                                         const elfcpp::Sym<32, false>& lsym);
 222
 223     inline bool
 224     global_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
 225                                          Target_i386* target,
 226                                          Sized_relobj<32, false>* object,
 227                                          unsigned int data_shndx,
 228                                          Output_section* output_section,
 229                                          const elfcpp::Rel<32, false>& reloc,
 230                                          unsigned int r_type,
 231                                          Symbol* gsym);
 232
 233     inline bool
 234     possible_function_pointer_reloc(unsigned int r_type);
 235
 236     static void
 237     unsupported_reloc_local(Sized_relobj<32, false>*, unsigned int r_type);
 238
 239     static void
 240     unsupported_reloc_global(Sized_relobj<32, false>*, unsigned int r_type,
 241                              Symbol*);
 242   };
 243
 244   // The class which implements relocation.
 245   class Relocate
 246   {
 247    public:
 248     Relocate()
 249       : skip_call_tls_get_addr_(false),
 250         local_dynamic_type_(LOCAL_DYNAMIC_NONE)
 251     { }
 252
 253     ~Relocate()
 254     {
 255       if (this->skip_call_tls_get_addr_)
 256         {
 257           // FIXME: This needs to specify the location somehow.
 258           gold_error(_("missing expected TLS relocation"));
 259         }
 260     }
 261
 262     // Return whether the static relocation needs to be applied.
 263     inline bool
 264     should_apply_static_reloc(const Sized_symbol<32>* gsym,
 265                               int ref_flags,
 266                               bool is_32bit,
 267                               Output_section* output_section);
 268
 269     // Do a relocation.  Return false if the caller should not issue
 270     // any warnings about this relocation.
 271     inline bool
 272     relocate(const Relocate_info<32, false>*, Target_i386*, Output_section*,
 273              size_t relnum, const elfcpp::Rel<32, false>&,
 274              unsigned int r_type, const Sized_symbol<32>*,
 275              const Symbol_value<32>*,
 276              unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
 277              section_size_type);
 278
 279    private:
 280     // Do a TLS relocation.
 281     inline void
 282     relocate_tls(const Relocate_info<32, false>*, Target_i386* target,
 283                  size_t relnum, const elfcpp::Rel<32, false>&,
 284                  unsigned int r_type, const Sized_symbol<32>*,
 285                  const Symbol_value<32>*,
 286                  unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
 287                  section_size_type);
 288
 289     // Do a TLS General-Dynamic to Initial-Exec transition.
 290     inline void
 291     tls_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
 292                  Output_segment* tls_segment,
 293                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 294                  elfcpp::Elf_types<32>::Elf_Addr value,
 295                  unsigned char* view,
 296                  section_size_type view_size);
 297
 298     // Do a TLS General-Dynamic to Local-Exec transition.
 299     inline void
 300     tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
 301                  Output_segment* tls_segment,
 302                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 303                  elfcpp::Elf_types<32>::Elf_Addr value,
 304                  unsigned char* view,
 305                  section_size_type view_size);
 306
 307     // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
 308     // transition.
 309     inline void
 310     tls_desc_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
 311                       Output_segment* tls_segment,
 312                       const elfcpp::Rel<32, false>&, unsigned int r_type,
 313                       elfcpp::Elf_types<32>::Elf_Addr value,
 314                       unsigned char* view,
 315                       section_size_type view_size);
 316
 317     // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
 318     // transition.
 319     inline void
 320     tls_desc_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
 321                       Output_segment* tls_segment,
 322                       const elfcpp::Rel<32, false>&, unsigned int r_type,
 323                       elfcpp::Elf_types<32>::Elf_Addr value,
 324                       unsigned char* view,
 325                       section_size_type view_size);
 326
 327     // Do a TLS Local-Dynamic to Local-Exec transition.
 328     inline void
 329     tls_ld_to_le(const Relocate_info<32, false>*, size_t relnum,
 330                  Output_segment* tls_segment,
 331                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 332                  elfcpp::Elf_types<32>::Elf_Addr value,
 333                  unsigned char* view,
 334                  section_size_type view_size);
 335
 336     // Do a TLS Initial-Exec to Local-Exec transition.
 337     static inline void
 338     tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum,
 339                  Output_segment* tls_segment,
 340                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 341                  elfcpp::Elf_types<32>::Elf_Addr value,
 342                  unsigned char* view,
 343                  section_size_type view_size);
 344
 345     // We need to keep track of which type of local dynamic relocation
 346     // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
 347     enum Local_dynamic_type
 348     {
 349       LOCAL_DYNAMIC_NONE,
 350       LOCAL_DYNAMIC_SUN,
 351       LOCAL_DYNAMIC_GNU
 352     };
 353
 354     // This is set if we should skip the next reloc, which should be a
 355     // PLT32 reloc against ___tls_get_addr.
 356     bool skip_call_tls_get_addr_;
 357     // The type of local dynamic relocation we have seen in the section
 358     // being relocated, if any.
 359     Local_dynamic_type local_dynamic_type_;
 360   };
 361
 362   // A class which returns the size required for a relocation type,
 363   // used while scanning relocs during a relocatable link.
 364   class Relocatable_size_for_reloc
 365   {
 366    public:
 367     unsigned int
 368     get_size_for_reloc(unsigned int, Relobj*);
 369   };
 370
 371   // Adjust TLS relocation type based on the options and whether this
 372   // is a local symbol.
 373   static tls::Tls_optimization
 374   optimize_tls_reloc(bool is_final, int r_type);
 375
 376   // Get the GOT section, creating it if necessary.
 377   Output_data_got<32, false>*
 378   got_section(Symbol_table*, Layout*);
 379
 380   // Get the GOT PLT section.
 381   Output_data_space*
 382   got_plt_section() const
 383   {
 384     gold_assert(this->got_plt_ != NULL);
 385     return this->got_plt_;
 386   }
 387
 388   // Create a PLT entry for a global symbol.
 389   void
 390   make_plt_entry(Symbol_table*, Layout*, Symbol*);
 391
 392   // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
 393   void
 394   define_tls_base_symbol(Symbol_table*, Layout*);
 395
 396   // Create a GOT entry for the TLS module index.
 397   unsigned int
 398   got_mod_index_entry(Symbol_table* symtab, Layout* layout,
 399                       Sized_relobj<32, false>* object);
 400
 401   // Get the PLT section.
 402   Output_data_plt_i386*
 403   plt_section() const
 404   {
 405     gold_assert(this->plt_ != NULL);
 406     return this->plt_;
 407   }
 408
 409   // Get the dynamic reloc section, creating it if necessary.
 410   Reloc_section*
 411   rel_dyn_section(Layout*);
 412
 413   // Get the section to use for TLS_DESC relocations.
 414   Reloc_section*
 415   rel_tls_desc_section(Layout*) const;
 416
 417   // Add a potential copy relocation.
 418   void
 419   copy_reloc(Symbol_table* symtab, Layout* layout,
 420              Sized_relobj<32, false>* object,
 421              unsigned int shndx, Output_section* output_section,
 422              Symbol* sym, const elfcpp::Rel<32, false>& reloc)
 423   {
 424     this->copy_relocs_.copy_reloc(symtab, layout,
 425                                   symtab->get_sized_symbol<32>(sym),
 426                                   object, shndx, output_section, reloc,
 427                                   this->rel_dyn_section(layout));
 428   }
 429
 430   // Information about this specific target which we pass to the
 431   // general Target structure.
 432   static const Target::Target_info i386_info;
 433
 434   // The types of GOT entries needed for this platform.
 435   enum Got_type
 436   {
 437     GOT_TYPE_STANDARD = 0,      // GOT entry for a regular symbol
 438     GOT_TYPE_TLS_NOFFSET = 1,   // GOT entry for negative TLS offset
 439     GOT_TYPE_TLS_OFFSET = 2,    // GOT entry for positive TLS offset
 440     GOT_TYPE_TLS_PAIR = 3,      // GOT entry for TLS module/offset pair
 441     GOT_TYPE_TLS_DESC = 4       // GOT entry for TLS_DESC pair
 442   };
 443
 444   // The GOT section.
 445   Output_data_got<32, false>* got_;
 446   // The PLT section.
 447   Output_data_plt_i386* plt_;
 448   // The GOT PLT section.
 449   Output_data_space* got_plt_;
 450   // The _GLOBAL_OFFSET_TABLE_ symbol.
 451   Symbol* global_offset_table_;
 452   // The dynamic reloc section.
 453   Reloc_section* rel_dyn_;
 454   // Relocs saved to avoid a COPY reloc.
 455   Copy_relocs<elfcpp::SHT_REL, 32, false> copy_relocs_;
 456   // Space for variables copied with a COPY reloc.
 457   Output_data_space* dynbss_;
 458   // Offset of the GOT entry for the TLS module index.
 459   unsigned int got_mod_index_offset_;
 460   // True if the _TLS_MODULE_BASE_ symbol has been defined.
 461   bool tls_base_symbol_defined_;
 462 };
 463
 464 const Target::Target_info Target_i386::i386_info =
 465 {
 466   32,                   // size
 467   false,                // is_big_endian
 468   elfcpp::EM_386,       // machine_code
 469   false,                // has_make_symbol
 470   false,                // has_resolve
 471   true,                 // has_code_fill
 472   true,                 // is_default_stack_executable
 473   '\0',                 // wrap_char
 474   "/usr/lib/libc.so.1", // dynamic_linker
 475   0x08048000,           // default_text_segment_address
 476   0x1000,               // abi_pagesize (overridable by -z max-page-size)
 477   0x1000,               // common_pagesize (overridable by -z common-page-size)
 478   elfcpp::SHN_UNDEF,    // small_common_shndx
 479   elfcpp::SHN_UNDEF,    // large_common_shndx
 480   0,                    // small_common_section_flags
 481   0,                    // large_common_section_flags
 482   NULL,                 // attributes_section
 483   NULL                  // attributes_vendor
 484 };
 485
 486 // Get the GOT section, creating it if necessary.
 487
 488 Output_data_got<32, false>*
 489 Target_i386::got_section(Symbol_table* symtab, Layout* layout)
 490 {
 491   if (this->got_ == NULL)
 492     {
 493       gold_assert(symtab != NULL && layout != NULL);
 494
 495       this->got_ = new Output_data_got<32, false>();
 496
 497       Output_section* os;
 498       os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
 499                                            (elfcpp::SHF_ALLOC
 500                                             | elfcpp::SHF_WRITE),
 501                                            this->got_, false, true, true,
 502                                            false);
 503
 504       this->got_plt_ = new Output_data_space(4, "** GOT PLT");
 505       os = layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
 506                                            (elfcpp::SHF_ALLOC
 507                                             | elfcpp::SHF_WRITE),
 508                                            this->got_plt_, false, false, false,
 509                                            true);
 510
 511       // The first three entries are reserved.
 512       this->got_plt_->set_current_data_size(3 * 4);
 513
 514       // Those bytes can go into the relro segment.
 515       layout->increase_relro(3 * 4);
 516
 517       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
 518       this->global_offset_table_ =
 519         symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
 520                                       Symbol_table::PREDEFINED,
 521                                       this->got_plt_,
 522                                       0, 0, elfcpp::STT_OBJECT,
 523                                       elfcpp::STB_LOCAL,
 524                                       elfcpp::STV_HIDDEN, 0,
 525                                       false, false);
 526     }
 527
 528   return this->got_;
 529 }
 530
 531 // Get the dynamic reloc section, creating it if necessary.
 532
 533 Target_i386::Reloc_section*
 534 Target_i386::rel_dyn_section(Layout* layout)
 535 {
 536   if (this->rel_dyn_ == NULL)
 537     {
 538       gold_assert(layout != NULL);
 539       this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
 540       layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
 541                                       elfcpp::SHF_ALLOC, this->rel_dyn_, true,
 542                                       false, false, false);
 543     }
 544   return this->rel_dyn_;
 545 }
 546
 547 // A class to handle the PLT data.
 548
 549 class Output_data_plt_i386 : public Output_section_data
 550 {
 551  public:
 552   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
 553
 554   Output_data_plt_i386(Layout*, Output_data_space*);
 555
 556   // Add an entry to the PLT.
 557   void
 558   add_entry(Symbol* gsym);
 559
 560   // Return the .rel.plt section data.
 561   const Reloc_section*
 562   rel_plt() const
 563   { return this->rel_; }
 564
 565   // Return where the TLS_DESC relocations should go.
 566   Reloc_section*
 567   rel_tls_desc(Layout*);
 568
 569  protected:
 570   void
 571   do_adjust_output_section(Output_section* os);
 572
 573   // Write to a map file.
 574   void
 575   do_print_to_mapfile(Mapfile* mapfile) const
 576   { mapfile->print_output_data(this, _("** PLT")); }
 577
 578  private:
 579   // The size of an entry in the PLT.
 580   static const int plt_entry_size = 16;
 581
 582   // The first entry in the PLT for an executable.
 583   static unsigned char exec_first_plt_entry[plt_entry_size];
 584
 585   // The first entry in the PLT for a shared object.
 586   static unsigned char dyn_first_plt_entry[plt_entry_size];
 587
 588   // Other entries in the PLT for an executable.
 589   static unsigned char exec_plt_entry[plt_entry_size];
 590
 591   // Other entries in the PLT for a shared object.
 592   static unsigned char dyn_plt_entry[plt_entry_size];
 593
 594   // Set the final size.
 595   void
 596   set_final_data_size()
 597   { this->set_data_size((this->count_ + 1) * plt_entry_size); }
 598
 599   // Write out the PLT data.
 600   void
 601   do_write(Output_file*);
 602
 603   // The reloc section.
 604   Reloc_section* rel_;
 605   // The TLS_DESC relocations, if necessary.  These must follow the
 606   // regular PLT relocs.
 607   Reloc_section* tls_desc_rel_;
 608   // The .got.plt section.
 609   Output_data_space* got_plt_;
 610   // The number of PLT entries.
 611   unsigned int count_;
 612 };
 613
 614 // Create the PLT section.  The ordinary .got section is an argument,
 615 // since we need to refer to the start.  We also create our own .got
 616 // section just for PLT entries.
 617
 618 Output_data_plt_i386::Output_data_plt_i386(Layout* layout,
 619                                            Output_data_space* got_plt)
 620   : Output_section_data(4), tls_desc_rel_(NULL), got_plt_(got_plt), count_(0)
 621 {
 622   this->rel_ = new Reloc_section(false);
 623   layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
 624                                   elfcpp::SHF_ALLOC, this->rel_, true,
 625                                   false, false, false);
 626 }
 627
 628 void
 629 Output_data_plt_i386::do_adjust_output_section(Output_section* os)
 630 {
 631   // UnixWare sets the entsize of .plt to 4, and so does the old GNU
 632   // linker, and so do we.
 633   os->set_entsize(4);
 634 }
 635
 636 // Add an entry to the PLT.
 637
 638 void
 639 Output_data_plt_i386::add_entry(Symbol* gsym)
 640 {
 641   gold_assert(!gsym->has_plt_offset());
 642
 643   // Note that when setting the PLT offset we skip the initial
 644   // reserved PLT entry.
 645   gsym->set_plt_offset((this->count_ + 1) * plt_entry_size);
 646
 647   ++this->count_;
 648
 649   section_offset_type got_offset = this->got_plt_->current_data_size();
 650
 651   // Every PLT entry needs a GOT entry which points back to the PLT
 652   // entry (this will be changed by the dynamic linker, normally
 653   // lazily when the function is called).
 654   this->got_plt_->set_current_data_size(got_offset + 4);
 655
 656   // Every PLT entry needs a reloc.
 657   gsym->set_needs_dynsym_entry();
 658   this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_,
 659                          got_offset);
 660
 661   // Note that we don't need to save the symbol.  The contents of the
 662   // PLT are independent of which symbols are used.  The symbols only
 663   // appear in the relocations.
 664 }
 665
 666 // Return where the TLS_DESC relocations should go, creating it if
 667 // necessary. These follow the JUMP_SLOT relocations.
 668
 669 Output_data_plt_i386::Reloc_section*
 670 Output_data_plt_i386::rel_tls_desc(Layout* layout)
 671 {
 672   if (this->tls_desc_rel_ == NULL)
 673     {
 674       this->tls_desc_rel_ = new Reloc_section(false);
 675       layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
 676                                       elfcpp::SHF_ALLOC, this->tls_desc_rel_,
 677                                       true, false, false, false);
 678       gold_assert(this->tls_desc_rel_->output_section() ==
 679                   this->rel_->output_section());
 680     }
 681   return this->tls_desc_rel_;
 682 }
 683
 684 // The first entry in the PLT for an executable.
 685
 686 unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] =
 687 {
 688   0xff, 0x35,   // pushl contents of memory address
 689   0, 0, 0, 0,   // replaced with address of .got + 4
 690   0xff, 0x25,   // jmp indirect
 691   0, 0, 0, 0,   // replaced with address of .got + 8
 692   0, 0, 0, 0    // unused
 693 };
 694
 695 // The first entry in the PLT for a shared object.
 696
 697 unsigned char Output_data_plt_i386::dyn_first_plt_entry[plt_entry_size] =
 698 {
 699   0xff, 0xb3, 4, 0, 0, 0,       // pushl 4(%ebx)
 700   0xff, 0xa3, 8, 0, 0, 0,       // jmp *8(%ebx)
 701   0, 0, 0, 0                    // unused
 702 };
 703
 704 // Subsequent entries in the PLT for an executable.
 705
 706 unsigned char Output_data_plt_i386::exec_plt_entry[plt_entry_size] =
 707 {
 708   0xff, 0x25,   // jmp indirect
 709   0, 0, 0, 0,   // replaced with address of symbol in .got
 710   0x68,         // pushl immediate
 711   0, 0, 0, 0,   // replaced with offset into relocation table
 712   0xe9,         // jmp relative
 713   0, 0, 0, 0    // replaced with offset to start of .plt
 714 };
 715
 716 // Subsequent entries in the PLT for a shared object.
 717
 718 unsigned char Output_data_plt_i386::dyn_plt_entry[plt_entry_size] =
 719 {
 720   0xff, 0xa3,   // jmp *offset(%ebx)
 721   0, 0, 0, 0,   // replaced with offset of symbol in .got
 722   0x68,         // pushl immediate
 723   0, 0, 0, 0,   // replaced with offset into relocation table
 724   0xe9,         // jmp relative
 725   0, 0, 0, 0    // replaced with offset to start of .plt
 726 };
 727
 728 // Write out the PLT.  This uses the hand-coded instructions above,
 729 // and adjusts them as needed.  This is all specified by the i386 ELF
 730 // Processor Supplement.
 731
 732 void
 733 Output_data_plt_i386::do_write(Output_file* of)
 734 {
 735   const off_t offset = this->offset();
 736   const section_size_type oview_size =
 737     convert_to_section_size_type(this->data_size());
 738   unsigned char* const oview = of->get_output_view(offset, oview_size);
 739
 740   const off_t got_file_offset = this->got_plt_->offset();
 741   const section_size_type got_size =
 742     convert_to_section_size_type(this->got_plt_->data_size());
 743   unsigned char* const got_view = of->get_output_view(got_file_offset,
 744                                                       got_size);
 745
 746   unsigned char* pov = oview;
 747
 748   elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address();
 749   elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address();
 750
 751   if (parameters->options().output_is_position_independent())
 752     memcpy(pov, dyn_first_plt_entry, plt_entry_size);
 753   else
 754     {
 755       memcpy(pov, exec_first_plt_entry, plt_entry_size);
 756       elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
 757       elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
 758     }
 759   pov += plt_entry_size;
 760
 761   unsigned char* got_pov = got_view;
 762
 763   memset(got_pov, 0, 12);
 764   got_pov += 12;
 765
 766   const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
 767
 768   unsigned int plt_offset = plt_entry_size;
 769   unsigned int plt_rel_offset = 0;
 770   unsigned int got_offset = 12;
 771   const unsigned int count = this->count_;
 772   for (unsigned int i = 0;
 773        i < count;
 774        ++i,
 775          pov += plt_entry_size,
 776          got_pov += 4,
 777          plt_offset += plt_entry_size,
 778          plt_rel_offset += rel_size,
 779          got_offset += 4)
 780     {
 781       // Set and adjust the PLT entry itself.
 782
 783       if (parameters->options().output_is_position_independent())
 784         {
 785           memcpy(pov, dyn_plt_entry, plt_entry_size);
 786           elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
 787         }
 788       else
 789         {
 790           memcpy(pov, exec_plt_entry, plt_entry_size);
 791           elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
 792                                                       (got_address
 793                                                        + got_offset));
 794         }
 795
 796       elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
 797       elfcpp::Swap<32, false>::writeval(pov + 12,
 798                                         - (plt_offset + plt_entry_size));
 799
 800       // Set the entry in the GOT.
 801       elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6);
 802     }
 803
 804   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
 805   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
 806
 807   of->write_output_view(offset, oview_size, oview);
 808   of->write_output_view(got_file_offset, got_size, got_view);
 809 }
 810
 811 // Create a PLT entry for a global symbol.
 812
 813 void
 814 Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym)
 815 {
 816   if (gsym->has_plt_offset())
 817     return;
 818
 819   if (this->plt_ == NULL)
 820     {
 821       // Create the GOT sections first.
 822       this->got_section(symtab, layout);
 823
 824       this->plt_ = new Output_data_plt_i386(layout, this->got_plt_);
 825       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
 826                                       (elfcpp::SHF_ALLOC
 827                                        | elfcpp::SHF_EXECINSTR),
 828                                       this->plt_, false, false, false, false);
 829     }
 830
 831   this->plt_->add_entry(gsym);
 832 }
 833
 834 // Get the section to use for TLS_DESC relocations.
 835
 836 Target_i386::Reloc_section*
 837 Target_i386::rel_tls_desc_section(Layout* layout) const
 838 {
 839   return this->plt_section()->rel_tls_desc(layout);
 840 }
 841
 842 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
 843
 844 void
 845 Target_i386::define_tls_base_symbol(Symbol_table* symtab, Layout* layout)
 846 {
 847   if (this->tls_base_symbol_defined_)
 848     return;
 849
 850   Output_segment* tls_segment = layout->tls_segment();
 851   if (tls_segment != NULL)
 852     {
 853       bool is_exec = parameters->options().output_is_executable();
 854       symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
 855                                        Symbol_table::PREDEFINED,
 856                                        tls_segment, 0, 0,
 857                                        elfcpp::STT_TLS,
 858                                        elfcpp::STB_LOCAL,
 859                                        elfcpp::STV_HIDDEN, 0,
 860                                        (is_exec
 861                                         ? Symbol::SEGMENT_END
 862                                         : Symbol::SEGMENT_START),
 863                                        true);
 864     }
 865   this->tls_base_symbol_defined_ = true;
 866 }
 867
 868 // Create a GOT entry for the TLS module index.
 869
 870 unsigned int
 871 Target_i386::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
 872                                  Sized_relobj<32, false>* object)
 873 {
 874   if (this->got_mod_index_offset_ == -1U)
 875     {
 876       gold_assert(symtab != NULL && layout != NULL && object != NULL);
 877       Reloc_section* rel_dyn = this->rel_dyn_section(layout);
 878       Output_data_got<32, false>* got = this->got_section(symtab, layout);
 879       unsigned int got_offset = got->add_constant(0);
 880       rel_dyn->add_local(object, 0, elfcpp::R_386_TLS_DTPMOD32, got,
 881                          got_offset);
 882       got->add_constant(0);
 883       this->got_mod_index_offset_ = got_offset;
 884     }
 885   return this->got_mod_index_offset_;
 886 }
 887
 888 // Optimize the TLS relocation type based on what we know about the
 889 // symbol.  IS_FINAL is true if the final address of this symbol is
 890 // known at link time.
 891
 892 tls::Tls_optimization
 893 Target_i386::optimize_tls_reloc(bool is_final, int r_type)
 894 {
 895   // If we are generating a shared library, then we can't do anything
 896   // in the linker.
 897   if (parameters->options().shared())
 898     return tls::TLSOPT_NONE;
 899
 900   switch (r_type)
 901     {
 902     case elfcpp::R_386_TLS_GD:
 903     case elfcpp::R_386_TLS_GOTDESC:
 904     case elfcpp::R_386_TLS_DESC_CALL:
 905       // These are General-Dynamic which permits fully general TLS
 906       // access.  Since we know that we are generating an executable,
 907       // we can convert this to Initial-Exec.  If we also know that
 908       // this is a local symbol, we can further switch to Local-Exec.
 909       if (is_final)
 910         return tls::TLSOPT_TO_LE;
 911       return tls::TLSOPT_TO_IE;
 912
 913     case elfcpp::R_386_TLS_LDM:
 914       // This is Local-Dynamic, which refers to a local symbol in the
 915       // dynamic TLS block.  Since we know that we generating an
 916       // executable, we can switch to Local-Exec.
 917       return tls::TLSOPT_TO_LE;
 918
 919     case elfcpp::R_386_TLS_LDO_32:
 920       // Another type of Local-Dynamic relocation.
 921       return tls::TLSOPT_TO_LE;
 922
 923     case elfcpp::R_386_TLS_IE:
 924     case elfcpp::R_386_TLS_GOTIE:
 925     case elfcpp::R_386_TLS_IE_32:
 926       // These are Initial-Exec relocs which get the thread offset
 927       // from the GOT.  If we know that we are linking against the
 928       // local symbol, we can switch to Local-Exec, which links the
 929       // thread offset into the instruction.
 930       if (is_final)
 931         return tls::TLSOPT_TO_LE;
 932       return tls::TLSOPT_NONE;
 933
 934     case elfcpp::R_386_TLS_LE:
 935     case elfcpp::R_386_TLS_LE_32:
 936       // When we already have Local-Exec, there is nothing further we
 937       // can do.
 938       return tls::TLSOPT_NONE;
 939
 940     default:
 941       gold_unreachable();
 942     }
 943 }
 944
 945 // Report an unsupported relocation against a local symbol.
 946
 947 void
 948 Target_i386::Scan::unsupported_reloc_local(Sized_relobj<32, false>* object,
 949                                            unsigned int r_type)
 950 {
 951   gold_error(_("%s: unsupported reloc %u against local symbol"),
 952              object->name().c_str(), r_type);
 953 }
 954
 955 // Scan a relocation for a local symbol.
 956
 957 inline void
 958 Target_i386::Scan::local(Symbol_table* symtab,
 959                          Layout* layout,
 960                          Target_i386* target,
 961                          Sized_relobj<32, false>* object,
 962                          unsigned int data_shndx,
 963                          Output_section* output_section,
 964                          const elfcpp::Rel<32, false>& reloc,
 965                          unsigned int r_type,
 966                          const elfcpp::Sym<32, false>& lsym)
 967 {
 968   switch (r_type)
 969     {
 970     case elfcpp::R_386_NONE:
 971     case elfcpp::R_386_GNU_VTINHERIT:
 972     case elfcpp::R_386_GNU_VTENTRY:
 973       break;
 974
 975     case elfcpp::R_386_32:
 976       // If building a shared library (or a position-independent
 977       // executable), we need to create a dynamic relocation for
 978       // this location. The relocation applied at link time will
 979       // apply the link-time value, so we flag the location with
 980       // an R_386_RELATIVE relocation so the dynamic loader can
 981       // relocate it easily.
 982       if (parameters->options().output_is_position_independent())
 983         {
 984           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
 985           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
 986           rel_dyn->add_local_relative(object, r_sym, elfcpp::R_386_RELATIVE,
 987                                       output_section, data_shndx,
 988                                       reloc.get_r_offset());
 989         }
 990       break;
 991
 992     case elfcpp::R_386_16:
 993     case elfcpp::R_386_8:
 994       // If building a shared library (or a position-independent
 995       // executable), we need to create a dynamic relocation for
 996       // this location. Because the addend needs to remain in the
 997       // data section, we need to be careful not to apply this
 998       // relocation statically.
 999       if (parameters->options().output_is_position_independent())
1000         {
1001           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1002           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1003           if (lsym.get_st_type() != elfcpp::STT_SECTION)
1004             rel_dyn->add_local(object, r_sym, r_type, output_section,
1005                                data_shndx, reloc.get_r_offset());
1006           else
1007             {
1008               gold_assert(lsym.get_st_value() == 0);
1009               unsigned int shndx = lsym.get_st_shndx();
1010               bool is_ordinary;
1011               shndx = object->adjust_sym_shndx(r_sym, shndx,
1012                                                &is_ordinary);
1013               if (!is_ordinary)
1014                 object->error(_("section symbol %u has bad shndx %u"),
1015                               r_sym, shndx);
1016               else
1017                 rel_dyn->add_local_section(object, shndx,
1018                                            r_type, output_section,
1019                                            data_shndx, reloc.get_r_offset());
1020             }
1021         }
1022       break;
1023
1024     case elfcpp::R_386_PC32:
1025     case elfcpp::R_386_PC16:
1026     case elfcpp::R_386_PC8:
1027       break;
1028
1029     case elfcpp::R_386_PLT32:
1030       // Since we know this is a local symbol, we can handle this as a
1031       // PC32 reloc.
1032       break;
1033
1034     case elfcpp::R_386_GOTOFF:
1035     case elfcpp::R_386_GOTPC:
1036       // We need a GOT section.
1037       target->got_section(symtab, layout);
1038       break;
1039
1040     case elfcpp::R_386_GOT32:
1041       {
1042         // The symbol requires a GOT entry.
1043         Output_data_got<32, false>* got = target->got_section(symtab, layout);
1044         unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1045         if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
1046           {
1047             // If we are generating a shared object, we need to add a
1048             // dynamic RELATIVE relocation for this symbol's GOT entry.
1049             if (parameters->options().output_is_position_independent())
1050               {
1051                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1052                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1053                 rel_dyn->add_local_relative(
1054                     object, r_sym, elfcpp::R_386_RELATIVE, got,
1055                     object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
1056               }
1057           }
1058       }
1059       break;
1060
1061       // These are relocations which should only be seen by the
1062       // dynamic linker, and should never be seen here.
1063     case elfcpp::R_386_COPY:
1064     case elfcpp::R_386_GLOB_DAT:
1065     case elfcpp::R_386_JUMP_SLOT:
1066     case elfcpp::R_386_RELATIVE:
1067     case elfcpp::R_386_TLS_TPOFF:
1068     case elfcpp::R_386_TLS_DTPMOD32:
1069     case elfcpp::R_386_TLS_DTPOFF32:
1070     case elfcpp::R_386_TLS_TPOFF32:
1071     case elfcpp::R_386_TLS_DESC:
1072       gold_error(_("%s: unexpected reloc %u in object file"),
1073                  object->name().c_str(), r_type);
1074       break;
1075
1076       // These are initial TLS relocs, which are expected when
1077       // linking.
1078     case elfcpp::R_386_TLS_GD:            // Global-dynamic
1079     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
1080     case elfcpp::R_386_TLS_DESC_CALL:
1081     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
1082     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
1083     case elfcpp::R_386_TLS_IE:            // Initial-exec
1084     case elfcpp::R_386_TLS_IE_32:
1085     case elfcpp::R_386_TLS_GOTIE:
1086     case elfcpp::R_386_TLS_LE:            // Local-exec
1087     case elfcpp::R_386_TLS_LE_32:
1088       {
1089         bool output_is_shared = parameters->options().shared();
1090         const tls::Tls_optimization optimized_type
1091             = Target_i386::optimize_tls_reloc(!output_is_shared, r_type);
1092         switch (r_type)
1093           {
1094           case elfcpp::R_386_TLS_GD:          // Global-dynamic
1095             if (optimized_type == tls::TLSOPT_NONE)
1096               {
1097                 // Create a pair of GOT entries for the module index and
1098                 // dtv-relative offset.
1099                 Output_data_got<32, false>* got
1100                     = target->got_section(symtab, layout);
1101                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1102                 unsigned int shndx = lsym.get_st_shndx();
1103                 bool is_ordinary;
1104                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1105                 if (!is_ordinary)
1106                   object->error(_("local symbol %u has bad shndx %u"),
1107                               r_sym, shndx);
1108                 else
1109                   got->add_local_pair_with_rel(object, r_sym, shndx,
1110                                                GOT_TYPE_TLS_PAIR,
1111                                                target->rel_dyn_section(layout),
1112                                                elfcpp::R_386_TLS_DTPMOD32, 0);
1113               }
1114             else if (optimized_type != tls::TLSOPT_TO_LE)
1115               unsupported_reloc_local(object, r_type);
1116             break;
1117
1118           case elfcpp::R_386_TLS_GOTDESC:     // Global-dynamic (from ~oliva)
1119             target->define_tls_base_symbol(symtab, layout);
1120             if (optimized_type == tls::TLSOPT_NONE)
1121               {
1122                 // Create a double GOT entry with an R_386_TLS_DESC reloc.
1123                 Output_data_got<32, false>* got
1124                     = target->got_section(symtab, layout);
1125                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1126                 if (!object->local_has_got_offset(r_sym, GOT_TYPE_TLS_DESC))
1127                   {
1128                     unsigned int got_offset = got->add_constant(0);
1129                     // The local symbol value is stored in the second
1130                     // GOT entry.
1131                     got->add_local(object, r_sym, GOT_TYPE_TLS_DESC);
1132                     // That set the GOT offset of the local symbol to
1133                     // point to the second entry, but we want it to
1134                     // point to the first.
1135                     object->set_local_got_offset(r_sym, GOT_TYPE_TLS_DESC,
1136                                                  got_offset);
1137                     Reloc_section* rt = target->rel_tls_desc_section(layout);
1138                     rt->add_absolute(elfcpp::R_386_TLS_DESC, got, got_offset);
1139                   }
1140               }
1141             else if (optimized_type != tls::TLSOPT_TO_LE)
1142               unsupported_reloc_local(object, r_type);
1143             break;
1144
1145           case elfcpp::R_386_TLS_DESC_CALL:
1146             break;
1147
1148           case elfcpp::R_386_TLS_LDM:         // Local-dynamic
1149             if (optimized_type == tls::TLSOPT_NONE)
1150               {
1151                 // Create a GOT entry for the module index.
1152                 target->got_mod_index_entry(symtab, layout, object);
1153               }
1154             else if (optimized_type != tls::TLSOPT_TO_LE)
1155               unsupported_reloc_local(object, r_type);
1156             break;
1157
1158           case elfcpp::R_386_TLS_LDO_32:      // Alternate local-dynamic
1159             break;
1160
1161           case elfcpp::R_386_TLS_IE:          // Initial-exec
1162           case elfcpp::R_386_TLS_IE_32:
1163           case elfcpp::R_386_TLS_GOTIE:
1164             layout->set_has_static_tls();
1165             if (optimized_type == tls::TLSOPT_NONE)
1166               {
1167                 // For the R_386_TLS_IE relocation, we need to create a
1168                 // dynamic relocation when building a shared library.
1169                 if (r_type == elfcpp::R_386_TLS_IE
1170                     && parameters->options().shared())
1171                   {
1172                     Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1173                     unsigned int r_sym
1174                         = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1175                     rel_dyn->add_local_relative(object, r_sym,
1176                                                 elfcpp::R_386_RELATIVE,
1177                                                 output_section, data_shndx,
1178                                                 reloc.get_r_offset());
1179                   }
1180                 // Create a GOT entry for the tp-relative offset.
1181                 Output_data_got<32, false>* got
1182                     = target->got_section(symtab, layout);
1183                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1184                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
1185                                            ? elfcpp::R_386_TLS_TPOFF32
1186                                            : elfcpp::R_386_TLS_TPOFF);
1187                 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
1188                                          ? GOT_TYPE_TLS_OFFSET
1189                                          : GOT_TYPE_TLS_NOFFSET);
1190                 got->add_local_with_rel(object, r_sym, got_type,
1191                                         target->rel_dyn_section(layout),
1192                                         dyn_r_type);
1193               }
1194             else if (optimized_type != tls::TLSOPT_TO_LE)
1195               unsupported_reloc_local(object, r_type);
1196             break;
1197
1198           case elfcpp::R_386_TLS_LE:          // Local-exec
1199           case elfcpp::R_386_TLS_LE_32:
1200             layout->set_has_static_tls();
1201             if (output_is_shared)
1202               {
1203                 // We need to create a dynamic relocation.
1204                 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
1205                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1206                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
1207                                            ? elfcpp::R_386_TLS_TPOFF32
1208                                            : elfcpp::R_386_TLS_TPOFF);
1209                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1210                 rel_dyn->add_local(object, r_sym, dyn_r_type, output_section,
1211                                    data_shndx, reloc.get_r_offset());
1212               }
1213             break;
1214
1215           default:
1216             gold_unreachable();
1217           }
1218       }
1219       break;
1220
1221     case elfcpp::R_386_32PLT:
1222     case elfcpp::R_386_TLS_GD_32:
1223     case elfcpp::R_386_TLS_GD_PUSH:
1224     case elfcpp::R_386_TLS_GD_CALL:
1225     case elfcpp::R_386_TLS_GD_POP:
1226     case elfcpp::R_386_TLS_LDM_32:
1227     case elfcpp::R_386_TLS_LDM_PUSH:
1228     case elfcpp::R_386_TLS_LDM_CALL:
1229     case elfcpp::R_386_TLS_LDM_POP:
1230     case elfcpp::R_386_USED_BY_INTEL_200:
1231     default:
1232       unsupported_reloc_local(object, r_type);
1233       break;
1234     }
1235 }
1236
1237 // Report an unsupported relocation against a global symbol.
1238
1239 void
1240 Target_i386::Scan::unsupported_reloc_global(Sized_relobj<32, false>* object,
1241                                             unsigned int r_type,
1242                                             Symbol* gsym)
1243 {
1244   gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1245              object->name().c_str(), r_type, gsym->demangled_name().c_str());
1246 }
1247
1248 inline bool
1249 Target_i386::Scan::possible_function_pointer_reloc(unsigned int r_type)
1250 {
1251   switch (r_type)
1252     {
1253     case elfcpp::R_386_32:
1254     case elfcpp::R_386_16:
1255     case elfcpp::R_386_8:
1256     case elfcpp::R_386_GOTOFF:
1257     case elfcpp::R_386_GOT32:
1258       {
1259         return true;
1260       }
1261     default:
1262       return false;
1263     }
1264   return false;
1265 }
1266
1267 inline bool
1268 Target_i386::Scan::local_reloc_may_be_function_pointer(
1269   Symbol_table* ,
1270   Layout* ,
1271   Target_i386* ,
1272   Sized_relobj<32, false>* ,
1273   unsigned int ,
1274   Output_section* ,
1275   const elfcpp::Rel<32, false>& ,
1276   unsigned int r_type,
1277   const elfcpp::Sym<32, false>&)
1278 {
1279   return possible_function_pointer_reloc(r_type);
1280 }
1281
1282 inline bool
1283 Target_i386::Scan::global_reloc_may_be_function_pointer(
1284   Symbol_table* ,
1285   Layout* ,
1286   Target_i386* ,
1287   Sized_relobj<32, false>* ,
1288   unsigned int ,
1289   Output_section* ,
1290   const elfcpp::Rel<32, false>& ,
1291   unsigned int r_type,
1292   Symbol*)
1293 {
1294   return possible_function_pointer_reloc(r_type);
1295 }
1296
1297 // Scan a relocation for a global symbol.
1298
1299 inline void
1300 Target_i386::Scan::global(Symbol_table* symtab,
1301                           Layout* layout,
1302                           Target_i386* target,
1303                           Sized_relobj<32, false>* object,
1304                           unsigned int data_shndx,
1305                           Output_section* output_section,
1306                           const elfcpp::Rel<32, false>& reloc,
1307                           unsigned int r_type,
1308                           Symbol* gsym)
1309 {
1310   switch (r_type)
1311     {
1312     case elfcpp::R_386_NONE:
1313     case elfcpp::R_386_GNU_VTINHERIT:
1314     case elfcpp::R_386_GNU_VTENTRY:
1315       break;
1316
1317     case elfcpp::R_386_32:
1318     case elfcpp::R_386_16:
1319     case elfcpp::R_386_8:
1320       {
1321         // Make a PLT entry if necessary.
1322         if (gsym->needs_plt_entry())
1323           {
1324             target->make_plt_entry(symtab, layout, gsym);
1325             // Since this is not a PC-relative relocation, we may be
1326             // taking the address of a function. In that case we need to
1327             // set the entry in the dynamic symbol table to the address of
1328             // the PLT entry.
1329             if (gsym->is_from_dynobj() && !parameters->options().shared())
1330               gsym->set_needs_dynsym_value();
1331           }
1332         // Make a dynamic relocation if necessary.
1333         if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
1334           {
1335             if (gsym->may_need_copy_reloc())
1336               {
1337                 target->copy_reloc(symtab, layout, object,
1338                                    data_shndx, output_section, gsym, reloc);
1339               }
1340             else if (r_type == elfcpp::R_386_32
1341                      && gsym->can_use_relative_reloc(false))
1342               {
1343                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1344                 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1345                                              output_section, object,
1346                                              data_shndx, reloc.get_r_offset());
1347               }
1348             else
1349               {
1350                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1351                 rel_dyn->add_global(gsym, r_type, output_section, object,
1352                                     data_shndx, reloc.get_r_offset());
1353               }
1354           }
1355       }
1356       break;
1357
1358     case elfcpp::R_386_PC32:
1359     case elfcpp::R_386_PC16:
1360     case elfcpp::R_386_PC8:
1361       {
1362         // Make a PLT entry if necessary.
1363         if (gsym->needs_plt_entry())
1364           {
1365             // These relocations are used for function calls only in
1366             // non-PIC code.  For a 32-bit relocation in a shared library,
1367             // we'll need a text relocation anyway, so we can skip the
1368             // PLT entry and let the dynamic linker bind the call directly
1369             // to the target.  For smaller relocations, we should use a
1370             // PLT entry to ensure that the call can reach.
1371             if (!parameters->options().shared()
1372                 || r_type != elfcpp::R_386_PC32)
1373               target->make_plt_entry(symtab, layout, gsym);
1374           }
1375         // Make a dynamic relocation if necessary.
1376         int flags = Symbol::NON_PIC_REF;
1377         if (gsym->is_func())
1378           flags |= Symbol::FUNCTION_CALL;
1379         if (gsym->needs_dynamic_reloc(flags))
1380           {
1381             if (gsym->may_need_copy_reloc())
1382               {
1383                 target->copy_reloc(symtab, layout, object,
1384                                    data_shndx, output_section, gsym, reloc);
1385               }
1386             else
1387               {
1388                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1389                 rel_dyn->add_global(gsym, r_type, output_section, object,
1390                                     data_shndx, reloc.get_r_offset());
1391               }
1392           }
1393       }
1394       break;
1395
1396     case elfcpp::R_386_GOT32:
1397       {
1398         // The symbol requires a GOT entry.
1399         Output_data_got<32, false>* got = target->got_section(symtab, layout);
1400         if (gsym->final_value_is_known())
1401           got->add_global(gsym, GOT_TYPE_STANDARD);
1402         else
1403           {
1404             // If this symbol is not fully resolved, we need to add a
1405             // GOT entry with a dynamic relocation.
1406             Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1407             if (gsym->is_from_dynobj()
1408                 || gsym->is_undefined()
1409                 || gsym->is_preemptible())
1410               got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
1411                                        rel_dyn, elfcpp::R_386_GLOB_DAT);
1412             else
1413               {
1414                 if (got->add_global(gsym, GOT_TYPE_STANDARD))
1415                   rel_dyn->add_global_relative(
1416                       gsym, elfcpp::R_386_RELATIVE, got,
1417                       gsym->got_offset(GOT_TYPE_STANDARD));
1418               }
1419           }
1420       }
1421       break;
1422
1423     case elfcpp::R_386_PLT32:
1424       // If the symbol is fully resolved, this is just a PC32 reloc.
1425       // Otherwise we need a PLT entry.
1426       if (gsym->final_value_is_known())
1427         break;
1428       // If building a shared library, we can also skip the PLT entry
1429       // if the symbol is defined in the output file and is protected
1430       // or hidden.
1431       if (gsym->is_defined()
1432           && !gsym->is_from_dynobj()
1433           && !gsym->is_preemptible())
1434         break;
1435       target->make_plt_entry(symtab, layout, gsym);
1436       break;
1437
1438     case elfcpp::R_386_GOTOFF:
1439     case elfcpp::R_386_GOTPC:
1440       // We need a GOT section.
1441       target->got_section(symtab, layout);
1442       break;
1443
1444       // These are relocations which should only be seen by the
1445       // dynamic linker, and should never be seen here.
1446     case elfcpp::R_386_COPY:
1447     case elfcpp::R_386_GLOB_DAT:
1448     case elfcpp::R_386_JUMP_SLOT:
1449     case elfcpp::R_386_RELATIVE:
1450     case elfcpp::R_386_TLS_TPOFF:
1451     case elfcpp::R_386_TLS_DTPMOD32:
1452     case elfcpp::R_386_TLS_DTPOFF32:
1453     case elfcpp::R_386_TLS_TPOFF32:
1454     case elfcpp::R_386_TLS_DESC:
1455       gold_error(_("%s: unexpected reloc %u in object file"),
1456                  object->name().c_str(), r_type);
1457       break;
1458
1459       // These are initial tls relocs, which are expected when
1460       // linking.
1461     case elfcpp::R_386_TLS_GD:            // Global-dynamic
1462     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
1463     case elfcpp::R_386_TLS_DESC_CALL:
1464     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
1465     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
1466     case elfcpp::R_386_TLS_IE:            // Initial-exec
1467     case elfcpp::R_386_TLS_IE_32:
1468     case elfcpp::R_386_TLS_GOTIE:
1469     case elfcpp::R_386_TLS_LE:            // Local-exec
1470     case elfcpp::R_386_TLS_LE_32:
1471       {
1472         const bool is_final = gsym->final_value_is_known();
1473         const tls::Tls_optimization optimized_type
1474             = Target_i386::optimize_tls_reloc(is_final, r_type);
1475         switch (r_type)
1476           {
1477           case elfcpp::R_386_TLS_GD:          // Global-dynamic
1478             if (optimized_type == tls::TLSOPT_NONE)
1479               {
1480                 // Create a pair of GOT entries for the module index and
1481                 // dtv-relative offset.
1482                 Output_data_got<32, false>* got
1483                     = target->got_section(symtab, layout);
1484                 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
1485                                              target->rel_dyn_section(layout),
1486                                              elfcpp::R_386_TLS_DTPMOD32,
1487                                              elfcpp::R_386_TLS_DTPOFF32);
1488               }
1489             else if (optimized_type == tls::TLSOPT_TO_IE)
1490               {
1491                 // Create a GOT entry for the tp-relative offset.
1492                 Output_data_got<32, false>* got
1493                     = target->got_section(symtab, layout);
1494                 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
1495                                          target->rel_dyn_section(layout),
1496                                          elfcpp::R_386_TLS_TPOFF);
1497               }
1498             else if (optimized_type != tls::TLSOPT_TO_LE)
1499               unsupported_reloc_global(object, r_type, gsym);
1500             break;
1501
1502           case elfcpp::R_386_TLS_GOTDESC:     // Global-dynamic (~oliva url)
1503             target->define_tls_base_symbol(symtab, layout);
1504             if (optimized_type == tls::TLSOPT_NONE)
1505               {
1506                 // Create a double GOT entry with an R_386_TLS_DESC reloc.
1507                 Output_data_got<32, false>* got
1508                     = target->got_section(symtab, layout);
1509                 Reloc_section* rt = target->rel_tls_desc_section(layout);
1510                 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC, rt,
1511                                              elfcpp::R_386_TLS_DESC, 0);
1512               }
1513             else if (optimized_type == tls::TLSOPT_TO_IE)
1514               {
1515                 // Create a GOT entry for the tp-relative offset.
1516                 Output_data_got<32, false>* got
1517                     = target->got_section(symtab, layout);
1518                 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
1519                                          target->rel_dyn_section(layout),
1520                                          elfcpp::R_386_TLS_TPOFF);
1521               }
1522             else if (optimized_type != tls::TLSOPT_TO_LE)
1523               unsupported_reloc_global(object, r_type, gsym);
1524             break;
1525
1526           case elfcpp::R_386_TLS_DESC_CALL:
1527             break;
1528
1529           case elfcpp::R_386_TLS_LDM:         // Local-dynamic
1530             if (optimized_type == tls::TLSOPT_NONE)
1531               {
1532                 // Create a GOT entry for the module index.
1533                 target->got_mod_index_entry(symtab, layout, object);
1534               }
1535             else if (optimized_type != tls::TLSOPT_TO_LE)
1536               unsupported_reloc_global(object, r_type, gsym);
1537             break;
1538
1539           case elfcpp::R_386_TLS_LDO_32:      // Alternate local-dynamic
1540             break;
1541
1542           case elfcpp::R_386_TLS_IE:          // Initial-exec
1543           case elfcpp::R_386_TLS_IE_32:
1544           case elfcpp::R_386_TLS_GOTIE:
1545             layout->set_has_static_tls();
1546             if (optimized_type == tls::TLSOPT_NONE)
1547               {
1548                 // For the R_386_TLS_IE relocation, we need to create a
1549                 // dynamic relocation when building a shared library.
1550                 if (r_type == elfcpp::R_386_TLS_IE
1551                     && parameters->options().shared())
1552                   {
1553                     Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1554                     rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1555                                                  output_section, object,
1556                                                  data_shndx,
1557                                                  reloc.get_r_offset());
1558                   }
1559                 // Create a GOT entry for the tp-relative offset.
1560                 Output_data_got<32, false>* got
1561                     = target->got_section(symtab, layout);
1562                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
1563                                            ? elfcpp::R_386_TLS_TPOFF32
1564                                            : elfcpp::R_386_TLS_TPOFF);
1565                 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
1566                                          ? GOT_TYPE_TLS_OFFSET
1567                                          : GOT_TYPE_TLS_NOFFSET);
1568                 got->add_global_with_rel(gsym, got_type,
1569                                          target->rel_dyn_section(layout),
1570                                          dyn_r_type);
1571               }
1572             else if (optimized_type != tls::TLSOPT_TO_LE)
1573               unsupported_reloc_global(object, r_type, gsym);
1574             break;
1575
1576           case elfcpp::R_386_TLS_LE:          // Local-exec
1577           case elfcpp::R_386_TLS_LE_32:
1578             layout->set_has_static_tls();
1579             if (parameters->options().shared())
1580               {
1581                 // We need to create a dynamic relocation.
1582                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
1583                                            ? elfcpp::R_386_TLS_TPOFF32
1584                                            : elfcpp::R_386_TLS_TPOFF);
1585                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1586                 rel_dyn->add_global(gsym, dyn_r_type, output_section, object,
1587                                     data_shndx, reloc.get_r_offset());
1588               }
1589             break;
1590
1591           default:
1592             gold_unreachable();
1593           }
1594       }
1595       break;
1596
1597     case elfcpp::R_386_32PLT:
1598     case elfcpp::R_386_TLS_GD_32:
1599     case elfcpp::R_386_TLS_GD_PUSH:
1600     case elfcpp::R_386_TLS_GD_CALL:
1601     case elfcpp::R_386_TLS_GD_POP:
1602     case elfcpp::R_386_TLS_LDM_32:
1603     case elfcpp::R_386_TLS_LDM_PUSH:
1604     case elfcpp::R_386_TLS_LDM_CALL:
1605     case elfcpp::R_386_TLS_LDM_POP:
1606     case elfcpp::R_386_USED_BY_INTEL_200:
1607     default:
1608       unsupported_reloc_global(object, r_type, gsym);
1609       break;
1610     }
1611 }
1612
1613 // Process relocations for gc.
1614
1615 void
1616 Target_i386::gc_process_relocs(Symbol_table* symtab,
1617                                Layout* layout,
1618                                Sized_relobj<32, false>* object,
1619                                unsigned int data_shndx,
1620                                unsigned int,
1621                                const unsigned char* prelocs,
1622                                size_t reloc_count,
1623                                Output_section* output_section,
1624                                bool needs_special_offset_handling,
1625                                size_t local_symbol_count,
1626                                const unsigned char* plocal_symbols)
1627 {
1628   gold::gc_process_relocs<32, false, Target_i386, elfcpp::SHT_REL,
1629                           Target_i386::Scan>(
1630     symtab,
1631     layout,
1632     this,
1633     object,
1634     data_shndx,
1635     prelocs,
1636     reloc_count,
1637     output_section,
1638     needs_special_offset_handling,
1639     local_symbol_count,
1640     plocal_symbols);
1641 }
1642
1643 // Scan relocations for a section.
1644
1645 void
1646 Target_i386::scan_relocs(Symbol_table* symtab,
1647                          Layout* layout,
1648                          Sized_relobj<32, false>* object,
1649                          unsigned int data_shndx,
1650                          unsigned int sh_type,
1651                          const unsigned char* prelocs,
1652                          size_t reloc_count,
1653                          Output_section* output_section,
1654                          bool needs_special_offset_handling,
1655                          size_t local_symbol_count,
1656                          const unsigned char* plocal_symbols)
1657 {
1658   if (sh_type == elfcpp::SHT_RELA)
1659     {
1660       gold_error(_("%s: unsupported RELA reloc section"),
1661                  object->name().c_str());
1662       return;
1663     }
1664
1665   gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL,
1666                     Target_i386::Scan>(
1667     symtab,
1668     layout,
1669     this,
1670     object,
1671     data_shndx,
1672     prelocs,
1673     reloc_count,
1674     output_section,
1675     needs_special_offset_handling,
1676     local_symbol_count,
1677     plocal_symbols);
1678 }
1679
1680 // Finalize the sections.
1681
1682 void
1683 Target_i386::do_finalize_sections(
1684     Layout* layout,
1685     const Input_objects*,
1686     Symbol_table* symtab)
1687 {
1688   const Reloc_section* rel_plt = (this->plt_ == NULL
1689                                   ? NULL
1690                                   : this->plt_->rel_plt());
1691   layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
1692                                   this->rel_dyn_, true, false);
1693
1694   // Emit any relocs we saved in an attempt to avoid generating COPY
1695   // relocs.
1696   if (this->copy_relocs_.any_saved_relocs())
1697     this->copy_relocs_.emit(this->rel_dyn_section(layout));
1698
1699   // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
1700   // the .got.plt section.
1701   Symbol* sym = this->global_offset_table_;
1702   if (sym != NULL)
1703     {
1704       uint32_t data_size = this->got_plt_->current_data_size();
1705       symtab->get_sized_symbol<32>(sym)->set_symsize(data_size);
1706     }
1707 }
1708
1709 // Return whether a direct absolute static relocation needs to be applied.
1710 // In cases where Scan::local() or Scan::global() has created
1711 // a dynamic relocation other than R_386_RELATIVE, the addend
1712 // of the relocation is carried in the data, and we must not
1713 // apply the static relocation.
1714
1715 inline bool
1716 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol<32>* gsym,
1717                                                  int ref_flags,
1718                                                  bool is_32bit,
1719                                                  Output_section* output_section)
1720 {
1721   // If the output section is not allocated, then we didn't call
1722   // scan_relocs, we didn't create a dynamic reloc, and we must apply
1723   // the reloc here.
1724   if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
1725     return true;
1726
1727   // For local symbols, we will have created a non-RELATIVE dynamic
1728   // relocation only if (a) the output is position independent,
1729   // (b) the relocation is absolute (not pc- or segment-relative), and
1730   // (c) the relocation is not 32 bits wide.
1731   if (gsym == NULL)
1732     return !(parameters->options().output_is_position_independent()
1733              && (ref_flags & Symbol::ABSOLUTE_REF)
1734              && !is_32bit);
1735
1736   // For global symbols, we use the same helper routines used in the
1737   // scan pass.  If we did not create a dynamic relocation, or if we
1738   // created a RELATIVE dynamic relocation, we should apply the static
1739   // relocation.
1740   bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
1741   bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
1742                 && gsym->can_use_relative_reloc(ref_flags
1743                                                 & Symbol::FUNCTION_CALL);
1744   return !has_dyn || is_rel;
1745 }
1746
1747 // Perform a relocation.
1748
1749 inline bool
1750 Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
1751                                 Target_i386* target,
1752                                 Output_section *output_section,
1753                                 size_t relnum,
1754                                 const elfcpp::Rel<32, false>& rel,
1755                                 unsigned int r_type,
1756                                 const Sized_symbol<32>* gsym,
1757                                 const Symbol_value<32>* psymval,
1758                                 unsigned char* view,
1759                                 elfcpp::Elf_types<32>::Elf_Addr address,
1760                                 section_size_type view_size)
1761 {
1762   if (this->skip_call_tls_get_addr_)
1763     {
1764       if ((r_type != elfcpp::R_386_PLT32
1765            && r_type != elfcpp::R_386_PC32)
1766           || gsym == NULL
1767           || strcmp(gsym->name(), "___tls_get_addr") != 0)
1768         gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1769                                _("missing expected TLS relocation"));
1770       else
1771         {
1772           this->skip_call_tls_get_addr_ = false;
1773           return false;
1774         }
1775     }
1776
1777   // Pick the value to use for symbols defined in shared objects.
1778   Symbol_value<32> symval;
1779   if (gsym != NULL
1780       && gsym->use_plt_offset(r_type == elfcpp::R_386_PC8
1781                               || r_type == elfcpp::R_386_PC16
1782                               || r_type == elfcpp::R_386_PC32))
1783     {
1784       symval.set_output_value(target->plt_section()->address()
1785                               + gsym->plt_offset());
1786       psymval = &symval;
1787     }
1788
1789   const Sized_relobj<32, false>* object = relinfo->object;
1790
1791   // Get the GOT offset if needed.
1792   // The GOT pointer points to the end of the GOT section.
1793   // We need to subtract the size of the GOT section to get
1794   // the actual offset to use in the relocation.
1795   bool have_got_offset = false;
1796   unsigned int got_offset = 0;
1797   switch (r_type)
1798     {
1799     case elfcpp::R_386_GOT32:
1800       if (gsym != NULL)
1801         {
1802           gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
1803           got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
1804                         - target->got_size());
1805         }
1806       else
1807         {
1808           unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
1809           gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
1810           got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
1811                         - target->got_size());
1812         }
1813       have_got_offset = true;
1814       break;
1815
1816     default:
1817       break;
1818     }
1819
1820   switch (r_type)
1821     {
1822     case elfcpp::R_386_NONE:
1823     case elfcpp::R_386_GNU_VTINHERIT:
1824     case elfcpp::R_386_GNU_VTENTRY:
1825       break;
1826
1827     case elfcpp::R_386_32:
1828       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
1829                                     output_section))
1830         Relocate_functions<32, false>::rel32(view, object, psymval);
1831       break;
1832
1833     case elfcpp::R_386_PC32:
1834       {
1835         int ref_flags = Symbol::NON_PIC_REF;
1836         if (gsym != NULL && gsym->is_func())
1837           ref_flags |= Symbol::FUNCTION_CALL;
1838         if (should_apply_static_reloc(gsym, ref_flags, true, output_section))
1839           Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1840       }
1841       break;
1842
1843     case elfcpp::R_386_16:
1844       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
1845                                     output_section))
1846         Relocate_functions<32, false>::rel16(view, object, psymval);
1847       break;
1848
1849     case elfcpp::R_386_PC16:
1850       {
1851         int ref_flags = Symbol::NON_PIC_REF;
1852         if (gsym != NULL && gsym->is_func())
1853           ref_flags |= Symbol::FUNCTION_CALL;
1854         if (should_apply_static_reloc(gsym, ref_flags, false, output_section))
1855           Relocate_functions<32, false>::pcrel16(view, object, psymval, address);
1856       }
1857       break;
1858
1859     case elfcpp::R_386_8:
1860       if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
1861                                     output_section))
1862         Relocate_functions<32, false>::rel8(view, object, psymval);
1863       break;
1864
1865     case elfcpp::R_386_PC8:
1866       {
1867         int ref_flags = Symbol::NON_PIC_REF;
1868         if (gsym != NULL && gsym->is_func())
1869           ref_flags |= Symbol::FUNCTION_CALL;
1870         if (should_apply_static_reloc(gsym, ref_flags, false,
1871                                       output_section))
1872           Relocate_functions<32, false>::pcrel8(view, object, psymval, address);
1873       }
1874       break;
1875
1876     case elfcpp::R_386_PLT32:
1877       gold_assert(gsym == NULL
1878                   || gsym->has_plt_offset()
1879                   || gsym->final_value_is_known()
1880                   || (gsym->is_defined()
1881                       && !gsym->is_from_dynobj()
1882                       && !gsym->is_preemptible()));
1883       Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
1884       break;
1885
1886     case elfcpp::R_386_GOT32:
1887       gold_assert(have_got_offset);
1888       Relocate_functions<32, false>::rel32(view, got_offset);
1889       break;
1890
1891     case elfcpp::R_386_GOTOFF:
1892       {
1893         elfcpp::Elf_types<32>::Elf_Addr value;
1894         value = (psymval->value(object, 0)
1895                  - target->got_plt_section()->address());
1896         Relocate_functions<32, false>::rel32(view, value);
1897       }
1898       break;
1899
1900     case elfcpp::R_386_GOTPC:
1901       {
1902         elfcpp::Elf_types<32>::Elf_Addr value;
1903         value = target->got_plt_section()->address();
1904         Relocate_functions<32, false>::pcrel32(view, value, address);
1905       }
1906       break;
1907
1908     case elfcpp::R_386_COPY:
1909     case elfcpp::R_386_GLOB_DAT:
1910     case elfcpp::R_386_JUMP_SLOT:
1911     case elfcpp::R_386_RELATIVE:
1912       // These are outstanding tls relocs, which are unexpected when
1913       // linking.
1914     case elfcpp::R_386_TLS_TPOFF:
1915     case elfcpp::R_386_TLS_DTPMOD32:
1916     case elfcpp::R_386_TLS_DTPOFF32:
1917     case elfcpp::R_386_TLS_TPOFF32:
1918     case elfcpp::R_386_TLS_DESC:
1919       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1920                              _("unexpected reloc %u in object file"),
1921                              r_type);
1922       break;
1923
1924       // These are initial tls relocs, which are expected when
1925       // linking.
1926     case elfcpp::R_386_TLS_GD:             // Global-dynamic
1927     case elfcpp::R_386_TLS_GOTDESC:        // Global-dynamic (from ~oliva url)
1928     case elfcpp::R_386_TLS_DESC_CALL:
1929     case elfcpp::R_386_TLS_LDM:            // Local-dynamic
1930     case elfcpp::R_386_TLS_LDO_32:         // Alternate local-dynamic
1931     case elfcpp::R_386_TLS_IE:             // Initial-exec
1932     case elfcpp::R_386_TLS_IE_32:
1933     case elfcpp::R_386_TLS_GOTIE:
1934     case elfcpp::R_386_TLS_LE:             // Local-exec
1935     case elfcpp::R_386_TLS_LE_32:
1936       this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
1937                          view, address, view_size);
1938       break;
1939
1940     case elfcpp::R_386_32PLT:
1941     case elfcpp::R_386_TLS_GD_32:
1942     case elfcpp::R_386_TLS_GD_PUSH:
1943     case elfcpp::R_386_TLS_GD_CALL:
1944     case elfcpp::R_386_TLS_GD_POP:
1945     case elfcpp::R_386_TLS_LDM_32:
1946     case elfcpp::R_386_TLS_LDM_PUSH:
1947     case elfcpp::R_386_TLS_LDM_CALL:
1948     case elfcpp::R_386_TLS_LDM_POP:
1949     case elfcpp::R_386_USED_BY_INTEL_200:
1950     default:
1951       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
1952                              _("unsupported reloc %u"),
1953                              r_type);
1954       break;
1955     }
1956
1957   return true;
1958 }
1959
1960 // Perform a TLS relocation.
1961
1962 inline void
1963 Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo,
1964                                     Target_i386* target,
1965                                     size_t relnum,
1966                                     const elfcpp::Rel<32, false>& rel,
1967                                     unsigned int r_type,
1968                                     const Sized_symbol<32>* gsym,
1969                                     const Symbol_value<32>* psymval,
1970                                     unsigned char* view,
1971                                     elfcpp::Elf_types<32>::Elf_Addr,
1972                                     section_size_type view_size)
1973 {
1974   Output_segment* tls_segment = relinfo->layout->tls_segment();
1975
1976   const Sized_relobj<32, false>* object = relinfo->object;
1977
1978   elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
1979
1980   const bool is_final = (gsym == NULL
1981                          ? !parameters->options().shared()
1982                          : gsym->final_value_is_known());
1983   const tls::Tls_optimization optimized_type
1984       = Target_i386::optimize_tls_reloc(is_final, r_type);
1985   switch (r_type)
1986     {
1987     case elfcpp::R_386_TLS_GD:           // Global-dynamic
1988       if (optimized_type == tls::TLSOPT_TO_LE)
1989         {
1990           gold_assert(tls_segment != NULL);
1991           this->tls_gd_to_le(relinfo, relnum, tls_segment,
1992                              rel, r_type, value, view,
1993                              view_size);
1994           break;
1995         }
1996       else
1997         {
1998           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
1999                                    ? GOT_TYPE_TLS_NOFFSET
2000                                    : GOT_TYPE_TLS_PAIR);
2001           unsigned int got_offset;
2002           if (gsym != NULL)
2003             {
2004               gold_assert(gsym->has_got_offset(got_type));
2005               got_offset = gsym->got_offset(got_type) - target->got_size();
2006             }
2007           else
2008             {
2009               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2010               gold_assert(object->local_has_got_offset(r_sym, got_type));
2011               got_offset = (object->local_got_offset(r_sym, got_type)
2012                             - target->got_size());
2013             }
2014           if (optimized_type == tls::TLSOPT_TO_IE)
2015             {
2016               gold_assert(tls_segment != NULL);
2017               this->tls_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
2018                                  got_offset, view, view_size);
2019               break;
2020             }
2021           else if (optimized_type == tls::TLSOPT_NONE)
2022             {
2023               // Relocate the field with the offset of the pair of GOT
2024               // entries.
2025               Relocate_functions<32, false>::rel32(view, got_offset);
2026               break;
2027             }
2028         }
2029       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2030                              _("unsupported reloc %u"),
2031                              r_type);
2032       break;
2033
2034     case elfcpp::R_386_TLS_GOTDESC:      // Global-dynamic (from ~oliva url)
2035     case elfcpp::R_386_TLS_DESC_CALL:
2036       this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
2037       if (optimized_type == tls::TLSOPT_TO_LE)
2038         {
2039           gold_assert(tls_segment != NULL);
2040           this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
2041                                   rel, r_type, value, view,
2042                                   view_size);
2043           break;
2044         }
2045       else
2046         {
2047           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
2048                                    ? GOT_TYPE_TLS_NOFFSET
2049                                    : GOT_TYPE_TLS_DESC);
2050           unsigned int got_offset;
2051           if (gsym != NULL)
2052             {
2053               gold_assert(gsym->has_got_offset(got_type));
2054               got_offset = gsym->got_offset(got_type) - target->got_size();
2055             }
2056           else
2057             {
2058               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2059               gold_assert(object->local_has_got_offset(r_sym, got_type));
2060               got_offset = (object->local_got_offset(r_sym, got_type)
2061                             - target->got_size());
2062             }
2063           if (optimized_type == tls::TLSOPT_TO_IE)
2064             {
2065               gold_assert(tls_segment != NULL);
2066               this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
2067                                       got_offset, view, view_size);
2068               break;
2069             }
2070           else if (optimized_type == tls::TLSOPT_NONE)
2071             {
2072               if (r_type == elfcpp::R_386_TLS_GOTDESC)
2073                 {
2074                   // Relocate the field with the offset of the pair of GOT
2075                   // entries.
2076                   Relocate_functions<32, false>::rel32(view, got_offset);
2077                 }
2078               break;
2079             }
2080         }
2081       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2082                              _("unsupported reloc %u"),
2083                              r_type);
2084       break;
2085
2086     case elfcpp::R_386_TLS_LDM:          // Local-dynamic
2087       if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN)
2088         {
2089           gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2090                                  _("both SUN and GNU model "
2091                                    "TLS relocations"));
2092           break;
2093         }
2094       this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
2095       if (optimized_type == tls::TLSOPT_TO_LE)
2096         {
2097           gold_assert(tls_segment != NULL);
2098           this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, r_type,
2099                              value, view, view_size);
2100           break;
2101         }
2102       else if (optimized_type == tls::TLSOPT_NONE)
2103         {
2104           // Relocate the field with the offset of the GOT entry for
2105           // the module index.
2106           unsigned int got_offset;
2107           got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
2108                         - target->got_size());
2109           Relocate_functions<32, false>::rel32(view, got_offset);
2110           break;
2111         }
2112       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2113                              _("unsupported reloc %u"),
2114                              r_type);
2115       break;
2116
2117     case elfcpp::R_386_TLS_LDO_32:       // Alternate local-dynamic
2118       if (optimized_type == tls::TLSOPT_TO_LE)
2119         {
2120           // This reloc can appear in debugging sections, in which
2121           // case we must not convert to local-exec.  We decide what
2122           // to do based on whether the section is marked as
2123           // containing executable code.  That is what the GNU linker
2124           // does as well.
2125           elfcpp::Shdr<32, false> shdr(relinfo->data_shdr);
2126           if ((shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0)
2127             {
2128               gold_assert(tls_segment != NULL);
2129               value -= tls_segment->memsz();
2130             }
2131         }
2132       Relocate_functions<32, false>::rel32(view, value);
2133       break;
2134
2135     case elfcpp::R_386_TLS_IE:           // Initial-exec
2136     case elfcpp::R_386_TLS_GOTIE:
2137     case elfcpp::R_386_TLS_IE_32:
2138       if (optimized_type == tls::TLSOPT_TO_LE)
2139         {
2140           gold_assert(tls_segment != NULL);
2141           Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
2142                                               rel, r_type, value, view,
2143                                               view_size);
2144           break;
2145         }
2146       else if (optimized_type == tls::TLSOPT_NONE)
2147         {
2148           // Relocate the field with the offset of the GOT entry for
2149           // the tp-relative offset of the symbol.
2150           unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
2151                                    ? GOT_TYPE_TLS_OFFSET
2152                                    : GOT_TYPE_TLS_NOFFSET);
2153           unsigned int got_offset;
2154           if (gsym != NULL)
2155             {
2156               gold_assert(gsym->has_got_offset(got_type));
2157               got_offset = gsym->got_offset(got_type);
2158             }
2159           else
2160             {
2161               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2162               gold_assert(object->local_has_got_offset(r_sym, got_type));
2163               got_offset = object->local_got_offset(r_sym, got_type);
2164             }
2165           // For the R_386_TLS_IE relocation, we need to apply the
2166           // absolute address of the GOT entry.
2167           if (r_type == elfcpp::R_386_TLS_IE)
2168             got_offset += target->got_plt_section()->address();
2169           // All GOT offsets are relative to the end of the GOT.
2170           got_offset -= target->got_size();
2171           Relocate_functions<32, false>::rel32(view, got_offset);
2172           break;
2173         }
2174       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2175                              _("unsupported reloc %u"),
2176                              r_type);
2177       break;
2178
2179     case elfcpp::R_386_TLS_LE:           // Local-exec
2180       // If we're creating a shared library, a dynamic relocation will
2181       // have been created for this location, so do not apply it now.
2182       if (!parameters->options().shared())
2183         {
2184           gold_assert(tls_segment != NULL);
2185           value -= tls_segment->memsz();
2186           Relocate_functions<32, false>::rel32(view, value);
2187         }
2188       break;
2189
2190     case elfcpp::R_386_TLS_LE_32:
2191       // If we're creating a shared library, a dynamic relocation will
2192       // have been created for this location, so do not apply it now.
2193       if (!parameters->options().shared())
2194         {
2195           gold_assert(tls_segment != NULL);
2196           value = tls_segment->memsz() - value;
2197           Relocate_functions<32, false>::rel32(view, value);
2198         }
2199       break;
2200     }
2201 }
2202
2203 // Do a relocation in which we convert a TLS General-Dynamic to a
2204 // Local-Exec.
2205
2206 inline void
2207 Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo,
2208                                     size_t relnum,
2209                                     Output_segment* tls_segment,
2210                                     const elfcpp::Rel<32, false>& rel,
2211                                     unsigned int,
2212                                     elfcpp::Elf_types<32>::Elf_Addr value,
2213                                     unsigned char* view,
2214                                     section_size_type view_size)
2215 {
2216   // leal foo(,%reg,1),%eax; call ___tls_get_addr
2217   //  ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2218   // leal foo(%reg),%eax; call ___tls_get_addr
2219   //  ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2220
2221   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2222   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2223
2224   unsigned char op1 = view[-1];
2225   unsigned char op2 = view[-2];
2226
2227   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2228                  op2 == 0x8d || op2 == 0x04);
2229   tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2230
2231   int roff = 5;
2232
2233   if (op2 == 0x04)
2234     {
2235       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
2236       tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
2237       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2238                      ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
2239       memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2240     }
2241   else
2242     {
2243       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2244                      (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
2245       if (rel.get_r_offset() + 9 < view_size
2246           && view[9] == 0x90)
2247         {
2248           // There is a trailing nop.  Use the size byte subl.
2249           memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2250           roff = 6;
2251         }
2252       else
2253         {
2254           // Use the five byte subl.
2255           memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2256         }
2257     }
2258
2259   value = tls_segment->memsz() - value;
2260   Relocate_functions<32, false>::rel32(view + roff, value);
2261
2262   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2263   // We can skip it.
2264   this->skip_call_tls_get_addr_ = true;
2265 }
2266
2267 // Do a relocation in which we convert a TLS General-Dynamic to an
2268 // Initial-Exec.
2269
2270 inline void
2271 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info<32, false>* relinfo,
2272                                     size_t relnum,
2273                                     Output_segment*,
2274                                     const elfcpp::Rel<32, false>& rel,
2275                                     unsigned int,
2276                                     elfcpp::Elf_types<32>::Elf_Addr value,
2277                                     unsigned char* view,
2278                                     section_size_type view_size)
2279 {
2280   // leal foo(,%ebx,1),%eax; call ___tls_get_addr
2281   //  ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
2282
2283   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2284   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2285
2286   unsigned char op1 = view[-1];
2287   unsigned char op2 = view[-2];
2288
2289   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2290                  op2 == 0x8d || op2 == 0x04);
2291   tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2292
2293   int roff = 5;
2294
2295   // FIXME: For now, support only the first (SIB) form.
2296   tls::check_tls(relinfo, relnum, rel.get_r_offset(), op2 == 0x04);
2297
2298   if (op2 == 0x04)
2299     {
2300       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
2301       tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
2302       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2303                      ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
2304       memcpy(view - 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
2305     }
2306   else
2307     {
2308       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2309                      (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
2310       if (rel.get_r_offset() + 9 < view_size
2311           && view[9] == 0x90)
2312         {
2313           // FIXME: This is not the right instruction sequence.
2314           // There is a trailing nop.  Use the size byte subl.
2315           memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2316           roff = 6;
2317         }
2318       else
2319         {
2320           // FIXME: This is not the right instruction sequence.
2321           // Use the five byte subl.
2322           memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2323         }
2324     }
2325
2326   Relocate_functions<32, false>::rel32(view + roff, value);
2327
2328   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2329   // We can skip it.
2330   this->skip_call_tls_get_addr_ = true;
2331 }
2332
2333 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2334 // General-Dynamic to a Local-Exec.
2335
2336 inline void
2337 Target_i386::Relocate::tls_desc_gd_to_le(
2338     const Relocate_info<32, false>* relinfo,
2339     size_t relnum,
2340     Output_segment* tls_segment,
2341     const elfcpp::Rel<32, false>& rel,
2342     unsigned int r_type,
2343     elfcpp::Elf_types<32>::Elf_Addr value,
2344     unsigned char* view,
2345     section_size_type view_size)
2346 {
2347   if (r_type == elfcpp::R_386_TLS_GOTDESC)
2348     {
2349       // leal foo@TLSDESC(%ebx), %eax
2350       // ==> leal foo@NTPOFF, %eax
2351       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2352       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2353       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2354                      view[-2] == 0x8d && view[-1] == 0x83);
2355       view[-1] = 0x05;
2356       value -= tls_segment->memsz();
2357       Relocate_functions<32, false>::rel32(view, value);
2358     }
2359   else
2360     {
2361       // call *foo@TLSCALL(%eax)
2362       // ==> nop; nop
2363       gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
2364       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
2365       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2366                      view[0] == 0xff && view[1] == 0x10);
2367       view[0] = 0x66;
2368       view[1] = 0x90;
2369     }
2370 }
2371
2372 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2373 // General-Dynamic to an Initial-Exec.
2374
2375 inline void
2376 Target_i386::Relocate::tls_desc_gd_to_ie(
2377     const Relocate_info<32, false>* relinfo,
2378     size_t relnum,
2379     Output_segment*,
2380     const elfcpp::Rel<32, false>& rel,
2381     unsigned int r_type,
2382     elfcpp::Elf_types<32>::Elf_Addr value,
2383     unsigned char* view,
2384     section_size_type view_size)
2385 {
2386   if (r_type == elfcpp::R_386_TLS_GOTDESC)
2387     {
2388       // leal foo@TLSDESC(%ebx), %eax
2389       // ==> movl foo@GOTNTPOFF(%ebx), %eax
2390       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2391       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2392       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2393                      view[-2] == 0x8d && view[-1] == 0x83);
2394       view[-2] = 0x8b;
2395       Relocate_functions<32, false>::rel32(view, value);
2396     }
2397   else
2398     {
2399       // call *foo@TLSCALL(%eax)
2400       // ==> nop; nop
2401       gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
2402       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
2403       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2404                      view[0] == 0xff && view[1] == 0x10);
2405       view[0] = 0x66;
2406       view[1] = 0x90;
2407     }
2408 }
2409
2410 // Do a relocation in which we convert a TLS Local-Dynamic to a
2411 // Local-Exec.
2412
2413 inline void
2414 Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo,
2415                                     size_t relnum,
2416                                     Output_segment*,
2417                                     const elfcpp::Rel<32, false>& rel,
2418                                     unsigned int,
2419                                     elfcpp::Elf_types<32>::Elf_Addr,
2420                                     unsigned char* view,
2421                                     section_size_type view_size)
2422 {
2423   // leal foo(%reg), %eax; call ___tls_get_addr
2424   // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
2425
2426   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2427   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2428
2429   // FIXME: Does this test really always pass?
2430   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2431                  view[-2] == 0x8d && view[-1] == 0x83);
2432
2433   tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2434
2435   memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
2436
2437   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2438   // We can skip it.
2439   this->skip_call_tls_get_addr_ = true;
2440 }
2441
2442 // Do a relocation in which we convert a TLS Initial-Exec to a
2443 // Local-Exec.
2444
2445 inline void
2446 Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo,
2447                                     size_t relnum,
2448                                     Output_segment* tls_segment,
2449                                     const elfcpp::Rel<32, false>& rel,
2450                                     unsigned int r_type,
2451                                     elfcpp::Elf_types<32>::Elf_Addr value,
2452                                     unsigned char* view,
2453                                     section_size_type view_size)
2454 {
2455   // We have to actually change the instructions, which means that we
2456   // need to examine the opcodes to figure out which instruction we
2457   // are looking at.
2458   if (r_type == elfcpp::R_386_TLS_IE)
2459     {
2460       // movl %gs:XX,%eax  ==>  movl $YY,%eax
2461       // movl %gs:XX,%reg  ==>  movl $YY,%reg
2462       // addl %gs:XX,%reg  ==>  addl $YY,%reg
2463       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -1);
2464       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2465
2466       unsigned char op1 = view[-1];
2467       if (op1 == 0xa1)
2468         {
2469           // movl XX,%eax  ==>  movl $YY,%eax
2470           view[-1] = 0xb8;
2471         }
2472       else
2473         {
2474           tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2475
2476           unsigned char op2 = view[-2];
2477           if (op2 == 0x8b)
2478             {
2479               // movl XX,%reg  ==>  movl $YY,%reg
2480               tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2481                              (op1 & 0xc7) == 0x05);
2482               view[-2] = 0xc7;
2483               view[-1] = 0xc0 | ((op1 >> 3) & 7);
2484             }
2485           else if (op2 == 0x03)
2486             {
2487               // addl XX,%reg  ==>  addl $YY,%reg
2488               tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2489                              (op1 & 0xc7) == 0x05);
2490               view[-2] = 0x81;
2491               view[-1] = 0xc0 | ((op1 >> 3) & 7);
2492             }
2493           else
2494             tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
2495         }
2496     }
2497   else
2498     {
2499       // subl %gs:XX(%reg1),%reg2  ==>  subl $YY,%reg2
2500       // movl %gs:XX(%reg1),%reg2  ==>  movl $YY,%reg2
2501       // addl %gs:XX(%reg1),%reg2  ==>  addl $YY,$reg2
2502       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2503       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2504
2505       unsigned char op1 = view[-1];
2506       unsigned char op2 = view[-2];
2507       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2508                      (op1 & 0xc0) == 0x80 && (op1 & 7) != 4);
2509       if (op2 == 0x8b)
2510         {
2511           // movl %gs:XX(%reg1),%reg2  ==>  movl $YY,%reg2
2512           view[-2] = 0xc7;
2513           view[-1] = 0xc0 | ((op1 >> 3) & 7);
2514         }
2515       else if (op2 == 0x2b)
2516         {
2517           // subl %gs:XX(%reg1),%reg2  ==>  subl $YY,%reg2
2518           view[-2] = 0x81;
2519           view[-1] = 0xe8 | ((op1 >> 3) & 7);
2520         }
2521       else if (op2 == 0x03)
2522         {
2523           // addl %gs:XX(%reg1),%reg2  ==>  addl $YY,$reg2
2524           view[-2] = 0x81;
2525           view[-1] = 0xc0 | ((op1 >> 3) & 7);
2526         }
2527       else
2528         tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
2529     }
2530
2531   value = tls_segment->memsz() - value;
2532   if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE)
2533     value = - value;
2534
2535   Relocate_functions<32, false>::rel32(view, value);
2536 }
2537
2538 // Relocate section data.
2539
2540 void
2541 Target_i386::relocate_section(const Relocate_info<32, false>* relinfo,
2542                               unsigned int sh_type,
2543                               const unsigned char* prelocs,
2544                               size_t reloc_count,
2545                               Output_section* output_section,
2546                               bool needs_special_offset_handling,
2547                               unsigned char* view,
2548                               elfcpp::Elf_types<32>::Elf_Addr address,
2549                               section_size_type view_size,
2550                               const Reloc_symbol_changes* reloc_symbol_changes)
2551 {
2552   gold_assert(sh_type == elfcpp::SHT_REL);
2553
2554   gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL,
2555                          Target_i386::Relocate>(
2556     relinfo,
2557     this,
2558     prelocs,
2559     reloc_count,
2560     output_section,
2561     needs_special_offset_handling,
2562     view,
2563     address,
2564     view_size,
2565     reloc_symbol_changes);
2566 }
2567
2568 // Return the size of a relocation while scanning during a relocatable
2569 // link.
2570
2571 unsigned int
2572 Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
2573     unsigned int r_type,
2574     Relobj* object)
2575 {
2576   switch (r_type)
2577     {
2578     case elfcpp::R_386_NONE:
2579     case elfcpp::R_386_GNU_VTINHERIT:
2580     case elfcpp::R_386_GNU_VTENTRY:
2581     case elfcpp::R_386_TLS_GD:            // Global-dynamic
2582     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
2583     case elfcpp::R_386_TLS_DESC_CALL:
2584     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
2585     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
2586     case elfcpp::R_386_TLS_IE:            // Initial-exec
2587     case elfcpp::R_386_TLS_IE_32:
2588     case elfcpp::R_386_TLS_GOTIE:
2589     case elfcpp::R_386_TLS_LE:            // Local-exec
2590     case elfcpp::R_386_TLS_LE_32:
2591       return 0;
2592
2593     case elfcpp::R_386_32:
2594     case elfcpp::R_386_PC32:
2595     case elfcpp::R_386_GOT32:
2596     case elfcpp::R_386_PLT32:
2597     case elfcpp::R_386_GOTOFF:
2598     case elfcpp::R_386_GOTPC:
2599      return 4;
2600
2601     case elfcpp::R_386_16:
2602     case elfcpp::R_386_PC16:
2603       return 2;
2604
2605     case elfcpp::R_386_8:
2606     case elfcpp::R_386_PC8:
2607       return 1;
2608
2609       // These are relocations which should only be seen by the
2610       // dynamic linker, and should never be seen here.
2611     case elfcpp::R_386_COPY:
2612     case elfcpp::R_386_GLOB_DAT:
2613     case elfcpp::R_386_JUMP_SLOT:
2614     case elfcpp::R_386_RELATIVE:
2615     case elfcpp::R_386_TLS_TPOFF:
2616     case elfcpp::R_386_TLS_DTPMOD32:
2617     case elfcpp::R_386_TLS_DTPOFF32:
2618     case elfcpp::R_386_TLS_TPOFF32:
2619     case elfcpp::R_386_TLS_DESC:
2620       object->error(_("unexpected reloc %u in object file"), r_type);
2621       return 0;
2622
2623     case elfcpp::R_386_32PLT:
2624     case elfcpp::R_386_TLS_GD_32:
2625     case elfcpp::R_386_TLS_GD_PUSH:
2626     case elfcpp::R_386_TLS_GD_CALL:
2627     case elfcpp::R_386_TLS_GD_POP:
2628     case elfcpp::R_386_TLS_LDM_32:
2629     case elfcpp::R_386_TLS_LDM_PUSH:
2630     case elfcpp::R_386_TLS_LDM_CALL:
2631     case elfcpp::R_386_TLS_LDM_POP:
2632     case elfcpp::R_386_USED_BY_INTEL_200:
2633     default:
2634       object->error(_("unsupported reloc %u in object file"), r_type);
2635       return 0;
2636     }
2637 }
2638
2639 // Scan the relocs during a relocatable link.
2640
2641 void
2642 Target_i386::scan_relocatable_relocs(Symbol_table* symtab,
2643                                      Layout* layout,
2644                                      Sized_relobj<32, false>* object,
2645                                      unsigned int data_shndx,
2646                                      unsigned int sh_type,
2647                                      const unsigned char* prelocs,
2648                                      size_t reloc_count,
2649                                      Output_section* output_section,
2650                                      bool needs_special_offset_handling,
2651                                      size_t local_symbol_count,
2652                                      const unsigned char* plocal_symbols,
2653                                      Relocatable_relocs* rr)
2654 {
2655   gold_assert(sh_type == elfcpp::SHT_REL);
2656
2657   typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_REL,
2658     Relocatable_size_for_reloc> Scan_relocatable_relocs;
2659
2660   gold::scan_relocatable_relocs<32, false, elfcpp::SHT_REL,
2661       Scan_relocatable_relocs>(
2662     symtab,
2663     layout,
2664     object,
2665     data_shndx,
2666     prelocs,
2667     reloc_count,
2668     output_section,
2669     needs_special_offset_handling,
2670     local_symbol_count,
2671     plocal_symbols,
2672     rr);
2673 }
2674
2675 // Relocate a section during a relocatable link.
2676
2677 void
2678 Target_i386::relocate_for_relocatable(
2679     const Relocate_info<32, false>* relinfo,
2680     unsigned int sh_type,
2681     const unsigned char* prelocs,
2682     size_t reloc_count,
2683     Output_section* output_section,
2684     off_t offset_in_output_section,
2685     const Relocatable_relocs* rr,
2686     unsigned char* view,
2687     elfcpp::Elf_types<32>::Elf_Addr view_address,
2688     section_size_type view_size,
2689     unsigned char* reloc_view,
2690     section_size_type reloc_view_size)
2691 {
2692   gold_assert(sh_type == elfcpp::SHT_REL);
2693
2694   gold::relocate_for_relocatable<32, false, elfcpp::SHT_REL>(
2695     relinfo,
2696     prelocs,
2697     reloc_count,
2698     output_section,
2699     offset_in_output_section,
2700     rr,
2701     view,
2702     view_address,
2703     view_size,
2704     reloc_view,
2705     reloc_view_size);
2706 }
2707
2708 // Return the value to use for a dynamic which requires special
2709 // treatment.  This is how we support equality comparisons of function
2710 // pointers across shared library boundaries, as described in the
2711 // processor specific ABI supplement.
2712
2713 uint64_t
2714 Target_i386::do_dynsym_value(const Symbol* gsym) const
2715 {
2716   gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
2717   return this->plt_section()->address() + gsym->plt_offset();
2718 }
2719
2720 // Return a string used to fill a code section with nops to take up
2721 // the specified length.
2722
2723 std::string
2724 Target_i386::do_code_fill(section_size_type length) const
2725 {
2726   if (length >= 16)
2727     {
2728       // Build a jmp instruction to skip over the bytes.
2729       unsigned char jmp[5];
2730       jmp[0] = 0xe9;
2731       elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
2732       return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
2733               + std::string(length - 5, '\0'));
2734     }
2735
2736   // Nop sequences of various lengths.
2737   const char nop1[1] = { 0x90 };                   // nop
2738   const char nop2[2] = { 0x66, 0x90 };             // xchg %ax %ax
2739   const char nop3[3] = { 0x8d, 0x76, 0x00 };       // leal 0(%esi),%esi
2740   const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00};  // leal 0(%esi,1),%esi
2741   const char nop5[5] = { 0x90, 0x8d, 0x74, 0x26,   // nop
2742                          0x00 };                   // leal 0(%esi,1),%esi
2743   const char nop6[6] = { 0x8d, 0xb6, 0x00, 0x00,   // leal 0L(%esi),%esi
2744                          0x00, 0x00 };
2745   const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00,   // leal 0L(%esi,1),%esi
2746                          0x00, 0x00, 0x00 };
2747   const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26,   // nop
2748                          0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
2749   const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc,   // movl %esi,%esi
2750                          0x27, 0x00, 0x00, 0x00,   // leal 0L(%edi,1),%edi
2751                          0x00 };
2752   const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
2753                            0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
2754                            0x00, 0x00 };
2755   const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
2756                            0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
2757                            0x00, 0x00, 0x00 };
2758   const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2759                            0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
2760                            0x00, 0x00, 0x00, 0x00 };
2761   const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
2762                            0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
2763                            0x27, 0x00, 0x00, 0x00,
2764                            0x00 };
2765   const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
2766                            0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
2767                            0xbc, 0x27, 0x00, 0x00,
2768                            0x00, 0x00 };
2769   const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
2770                            0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
2771                            0x90, 0x90, 0x90, 0x90,
2772                            0x90, 0x90, 0x90 };
2773
2774   const char* nops[16] = {
2775     NULL,
2776     nop1, nop2, nop3, nop4, nop5, nop6, nop7,
2777     nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
2778   };
2779
2780   return std::string(nops[length], length);
2781 }
2782
2783 // Return whether SYM should be treated as a call to a non-split
2784 // function.  We don't want that to be true of a call to a
2785 // get_pc_thunk function.
2786
2787 bool
2788 Target_i386::do_is_call_to_non_split(const Symbol* sym, unsigned int) const
2789 {
2790   return (sym->type() == elfcpp::STT_FUNC
2791           && !is_prefix_of("__i686.get_pc_thunk.", sym->name()));
2792 }
2793
2794 // FNOFFSET in section SHNDX in OBJECT is the start of a function
2795 // compiled with -fstack-split.  The function calls non-stack-split
2796 // code.  We have to change the function so that it always ensures
2797 // that it has enough stack space to run some random function.
2798
2799 void
2800 Target_i386::do_calls_non_split(Relobj* object, unsigned int shndx,
2801                                 section_offset_type fnoffset,
2802                                 section_size_type fnsize,
2803                                 unsigned char* view,
2804                                 section_size_type view_size,
2805                                 std::string* from,
2806                                 std::string* to) const
2807 {
2808   // The function starts with a comparison of the stack pointer and a
2809   // field in the TCB.  This is followed by a jump.
2810
2811   // cmp %gs:NN,%esp
2812   if (this->match_view(view, view_size, fnoffset, "\x65\x3b\x25", 3)
2813       && fnsize > 7)
2814     {
2815       // We will call __morestack if the carry flag is set after this
2816       // comparison.  We turn the comparison into an stc instruction
2817       // and some nops.
2818       view[fnoffset] = '\xf9';
2819       this->set_view_to_nop(view, view_size, fnoffset + 1, 6);
2820     }
2821   // lea NN(%esp),%ecx
2822   // lea NN(%esp),%edx
2823   else if ((this->match_view(view, view_size, fnoffset, "\x8d\x8c\x24", 3)
2824             || this->match_view(view, view_size, fnoffset, "\x8d\x94\x24", 3))
2825            && fnsize > 7)
2826     {
2827       // This is loading an offset from the stack pointer for a
2828       // comparison.  The offset is negative, so we decrease the
2829       // offset by the amount of space we need for the stack.  This
2830       // means we will avoid calling __morestack if there happens to
2831       // be plenty of space on the stack already.
2832       unsigned char* pval = view + fnoffset + 3;
2833       uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
2834       val -= parameters->options().split_stack_adjust_size();
2835       elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
2836     }
2837   else
2838     {
2839       if (!object->has_no_split_stack())
2840         object->error(_("failed to match split-stack sequence at "
2841                         "section %u offset %0zx"),
2842                       shndx, static_cast<size_t>(fnoffset));
2843       return;
2844     }
2845
2846   // We have to change the function so that it calls
2847   // __morestack_non_split instead of __morestack.  The former will
2848   // allocate additional stack space.
2849   *from = "__morestack";
2850   *to = "__morestack_non_split";
2851 }
2852
2853 // The selector for i386 object files.
2854
2855 class Target_selector_i386 : public Target_selector_freebsd
2856 {
2857 public:
2858   Target_selector_i386()
2859     : Target_selector_freebsd(elfcpp::EM_386, 32, false,
2860                               "elf32-i386", "elf32-i386-freebsd")
2861   { }
2862
2863   Target*
2864   do_instantiate_target()
2865   { return new Target_i386(); }
2866 };
2867
2868 Target_selector_i386 target_selector_i386;
2869
2870 } // End anonymous namespace.