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