gold/i386.cc

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