gold/i386.cc

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