gold/i386.cc

   1 // i386.cc -- i386 target support for gold.
   2
   3 // Copyright 2006, 2007, 2008, 2009, 2010, 2011 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 "dwarf.h"
  29 #include "parameters.h"
  30 #include "reloc.h"
  31 #include "i386.h"
  32 #include "object.h"
  33 #include "symtab.h"
  34 #include "layout.h"
  35 #include "output.h"
  36 #include "copy-relocs.h"
  37 #include "target.h"
  38 #include "target-reloc.h"
  39 #include "target-select.h"
  40 #include "tls.h"
  41 #include "freebsd.h"
  42 #include "gc.h"
  43
  44 namespace
  45 {
  46
  47 using namespace gold;
  48
  49 // A class to handle the PLT data.
  50
  51 class Output_data_plt_i386 : public Output_section_data
  52 {
  53  public:
  54   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
  55
  56   Output_data_plt_i386(Layout*, Output_data_space*, Output_data_space*);
  57
  58   // Add an entry to the PLT.
  59   void
  60   add_entry(Symbol_table*, Layout*, Symbol* gsym);
  61
  62   // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
  63   unsigned int
  64   add_local_ifunc_entry(Symbol_table*, Layout*,
  65                         Sized_relobj_file<32, false>* relobj,
  66                         unsigned int local_sym_index);
  67
  68   // Return the .rel.plt section data.
  69   Reloc_section*
  70   rel_plt() const
  71   { return this->rel_; }
  72
  73   // Return where the TLS_DESC relocations should go.
  74   Reloc_section*
  75   rel_tls_desc(Layout*);
  76
  77   // Return where the IRELATIVE relocations should go.
  78   Reloc_section*
  79   rel_irelative(Symbol_table*, Layout*);
  80
  81   // Return whether we created a section for IRELATIVE relocations.
  82   bool
  83   has_irelative_section() const
  84   { return this->irelative_rel_ != NULL; }
  85
  86   // Return the number of PLT entries.
  87   unsigned int
  88   entry_count() const
  89   { return this->count_ + this->irelative_count_; }
  90
  91   // Return the offset of the first non-reserved PLT entry.
  92   static unsigned int
  93   first_plt_entry_offset()
  94   { return plt_entry_size; }
  95
  96   // Return the size of a PLT entry.
  97   static unsigned int
  98   get_plt_entry_size()
  99   { return plt_entry_size; }
 100
 101   // Return the PLT address to use for a global symbol.
 102   uint64_t
 103   address_for_global(const Symbol*);
 104
 105   // Return the PLT address to use for a local symbol.
 106   uint64_t
 107   address_for_local(const Relobj*, unsigned int symndx);
 108
 109  protected:
 110   void
 111   do_adjust_output_section(Output_section* os);
 112
 113   // Write to a map file.
 114   void
 115   do_print_to_mapfile(Mapfile* mapfile) const
 116   { mapfile->print_output_data(this, _("** PLT")); }
 117
 118  private:
 119   // The size of an entry in the PLT.
 120   static const int plt_entry_size = 16;
 121
 122   // The first entry in the PLT for an executable.
 123   static const unsigned char exec_first_plt_entry[plt_entry_size];
 124
 125   // The first entry in the PLT for a shared object.
 126   static const unsigned char dyn_first_plt_entry[plt_entry_size];
 127
 128   // Other entries in the PLT for an executable.
 129   static const unsigned char exec_plt_entry[plt_entry_size];
 130
 131   // Other entries in the PLT for a shared object.
 132   static const unsigned char dyn_plt_entry[plt_entry_size];
 133
 134   // The .eh_frame unwind information for the PLT.
 135   static const int plt_eh_frame_cie_size = 16;
 136   static const int plt_eh_frame_fde_size = 32;
 137   static const unsigned char plt_eh_frame_cie[plt_eh_frame_cie_size];
 138   static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
 139
 140   // Set the final size.
 141   void
 142   set_final_data_size()
 143   {
 144     this->set_data_size((this->count_ + this->irelative_count_ + 1)
 145                         * plt_entry_size);
 146   }
 147
 148   // Write out the PLT data.
 149   void
 150   do_write(Output_file*);
 151
 152   // We keep a list of global STT_GNU_IFUNC symbols, each with its
 153   // offset in the GOT.
 154   struct Global_ifunc
 155   {
 156     Symbol* sym;
 157     unsigned int got_offset;
 158   };
 159
 160   // We keep a list of local STT_GNU_IFUNC symbols, each with its
 161   // offset in the GOT.
 162   struct Local_ifunc
 163   {
 164     Sized_relobj_file<32, false>* object;
 165     unsigned int local_sym_index;
 166     unsigned int got_offset;
 167   };
 168
 169   // The reloc section.
 170   Reloc_section* rel_;
 171   // The TLS_DESC relocations, if necessary.  These must follow the
 172   // regular PLT relocs.
 173   Reloc_section* tls_desc_rel_;
 174   // The IRELATIVE relocations, if necessary.  These must follow the
 175   // regular relocatoins and the TLS_DESC relocations.
 176   Reloc_section* irelative_rel_;
 177   // The .got.plt section.
 178   Output_data_space* got_plt_;
 179   // The part of the .got.plt section used for IRELATIVE relocs.
 180   Output_data_space* got_irelative_;
 181   // The number of PLT entries.
 182   unsigned int count_;
 183   // Number of PLT entries with R_386_IRELATIVE relocs.  These follow
 184   // the regular PLT entries.
 185   unsigned int irelative_count_;
 186   // Global STT_GNU_IFUNC symbols.
 187   std::vector<Global_ifunc> global_ifuncs_;
 188   // Local STT_GNU_IFUNC symbols.
 189   std::vector<Local_ifunc> local_ifuncs_;
 190 };
 191
 192 // The i386 target class.
 193 // TLS info comes from
 194 //   http://people.redhat.com/drepper/tls.pdf
 195 //   http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
 196
 197 class Target_i386 : public Sized_target<32, false>
 198 {
 199  public:
 200   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
 201
 202   Target_i386()
 203     : Sized_target<32, false>(&i386_info),
 204       got_(NULL), plt_(NULL), got_plt_(NULL), got_irelative_(NULL),
 205       got_tlsdesc_(NULL), global_offset_table_(NULL), rel_dyn_(NULL),
 206       rel_irelative_(NULL), copy_relocs_(elfcpp::R_386_COPY), dynbss_(NULL),
 207       got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
 208   { }
 209
 210   // Process the relocations to determine unreferenced sections for
 211   // garbage collection.
 212   void
 213   gc_process_relocs(Symbol_table* symtab,
 214                     Layout* layout,
 215                     Sized_relobj_file<32, false>* object,
 216                     unsigned int data_shndx,
 217                     unsigned int sh_type,
 218                     const unsigned char* prelocs,
 219                     size_t reloc_count,
 220                     Output_section* output_section,
 221                     bool needs_special_offset_handling,
 222                     size_t local_symbol_count,
 223                     const unsigned char* plocal_symbols);
 224
 225   // Scan the relocations to look for symbol adjustments.
 226   void
 227   scan_relocs(Symbol_table* symtab,
 228               Layout* layout,
 229               Sized_relobj_file<32, false>* object,
 230               unsigned int data_shndx,
 231               unsigned int sh_type,
 232               const unsigned char* prelocs,
 233               size_t reloc_count,
 234               Output_section* output_section,
 235               bool needs_special_offset_handling,
 236               size_t local_symbol_count,
 237               const unsigned char* plocal_symbols);
 238
 239   // Finalize the sections.
 240   void
 241   do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
 242
 243   // Return the value to use for a dynamic which requires special
 244   // treatment.
 245   uint64_t
 246   do_dynsym_value(const Symbol*) const;
 247
 248   // Relocate a section.
 249   void
 250   relocate_section(const Relocate_info<32, false>*,
 251                    unsigned int sh_type,
 252                    const unsigned char* prelocs,
 253                    size_t reloc_count,
 254                    Output_section* output_section,
 255                    bool needs_special_offset_handling,
 256                    unsigned char* view,
 257                    elfcpp::Elf_types<32>::Elf_Addr view_address,
 258                    section_size_type view_size,
 259                    const Reloc_symbol_changes*);
 260
 261   // Scan the relocs during a relocatable link.
 262   void
 263   scan_relocatable_relocs(Symbol_table* symtab,
 264                           Layout* layout,
 265                           Sized_relobj_file<32, false>* object,
 266                           unsigned int data_shndx,
 267                           unsigned int sh_type,
 268                           const unsigned char* prelocs,
 269                           size_t reloc_count,
 270                           Output_section* output_section,
 271                           bool needs_special_offset_handling,
 272                           size_t local_symbol_count,
 273                           const unsigned char* plocal_symbols,
 274                           Relocatable_relocs*);
 275
 276   // Relocate a section during a relocatable link.
 277   void
 278   relocate_for_relocatable(const Relocate_info<32, false>*,
 279                            unsigned int sh_type,
 280                            const unsigned char* prelocs,
 281                            size_t reloc_count,
 282                            Output_section* output_section,
 283                            off_t offset_in_output_section,
 284                            const Relocatable_relocs*,
 285                            unsigned char* view,
 286                            elfcpp::Elf_types<32>::Elf_Addr view_address,
 287                            section_size_type view_size,
 288                            unsigned char* reloc_view,
 289                            section_size_type reloc_view_size);
 290
 291   // Return a string used to fill a code section with nops.
 292   std::string
 293   do_code_fill(section_size_type length) const;
 294
 295   // Return whether SYM is defined by the ABI.
 296   bool
 297   do_is_defined_by_abi(const Symbol* sym) const
 298   { return strcmp(sym->name(), "___tls_get_addr") == 0; }
 299
 300   // Return whether a symbol name implies a local label.  The UnixWare
 301   // 2.1 cc generates temporary symbols that start with .X, so we
 302   // recognize them here.  FIXME: do other SVR4 compilers also use .X?.
 303   // If so, we should move the .X recognition into
 304   // Target::do_is_local_label_name.
 305   bool
 306   do_is_local_label_name(const char* name) const
 307   {
 308     if (name[0] == '.' && name[1] == 'X')
 309       return true;
 310     return Target::do_is_local_label_name(name);
 311   }
 312
 313   // Return the PLT address to use for a global symbol.
 314   uint64_t
 315   do_plt_address_for_global(const Symbol* gsym) const
 316   { return this->plt_section()->address_for_global(gsym); }
 317
 318   uint64_t
 319   do_plt_address_for_local(const Relobj* relobj, unsigned int symndx) const
 320   { return this->plt_section()->address_for_local(relobj, symndx); }
 321
 322   // We can tell whether we take the address of a function.
 323   inline bool
 324   do_can_check_for_function_pointers() const
 325   { return true; }
 326
 327   // Return the base for a DW_EH_PE_datarel encoding.
 328   uint64_t
 329   do_ehframe_datarel_base() const;
 330
 331   // Return whether SYM is call to a non-split function.
 332   bool
 333   do_is_call_to_non_split(const Symbol* sym, unsigned int) const;
 334
 335   // Adjust -fsplit-stack code which calls non-split-stack code.
 336   void
 337   do_calls_non_split(Relobj* object, unsigned int shndx,
 338                      section_offset_type fnoffset, section_size_type fnsize,
 339                      unsigned char* view, section_size_type view_size,
 340                      std::string* from, std::string* to) const;
 341
 342   // Return the size of the GOT section.
 343   section_size_type
 344   got_size() const
 345   {
 346     gold_assert(this->got_ != NULL);
 347     return this->got_->data_size();
 348   }
 349
 350   // Return the number of entries in the GOT.
 351   unsigned int
 352   got_entry_count() const
 353   {
 354     if (this->got_ == NULL)
 355       return 0;
 356     return this->got_size() / 4;
 357   }
 358
 359   // Return the number of entries in the PLT.
 360   unsigned int
 361   plt_entry_count() const;
 362
 363   // Return the offset of the first non-reserved PLT entry.
 364   unsigned int
 365   first_plt_entry_offset() const;
 366
 367   // Return the size of each PLT entry.
 368   unsigned int
 369   plt_entry_size() const;
 370
 371  private:
 372   // The class which scans relocations.
 373   struct Scan
 374   {
 375     static inline int
 376
 377     get_reference_flags(unsigned int r_type);
 378
 379     inline void
 380     local(Symbol_table* symtab, Layout* layout, Target_i386* target,
 381           Sized_relobj_file<32, false>* object,
 382           unsigned int data_shndx,
 383           Output_section* output_section,
 384           const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
 385           const elfcpp::Sym<32, false>& lsym);
 386
 387     inline void
 388     global(Symbol_table* symtab, Layout* layout, Target_i386* target,
 389            Sized_relobj_file<32, false>* object,
 390            unsigned int data_shndx,
 391            Output_section* output_section,
 392            const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
 393            Symbol* gsym);
 394
 395     inline bool
 396     local_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
 397                                         Target_i386* target,
 398                                         Sized_relobj_file<32, false>* object,
 399                                         unsigned int data_shndx,
 400                                         Output_section* output_section,
 401                                         const elfcpp::Rel<32, false>& reloc,
 402                                         unsigned int r_type,
 403                                         const elfcpp::Sym<32, false>& lsym);
 404
 405     inline bool
 406     global_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
 407                                          Target_i386* target,
 408                                          Sized_relobj_file<32, false>* object,
 409                                          unsigned int data_shndx,
 410                                          Output_section* output_section,
 411                                          const elfcpp::Rel<32, false>& reloc,
 412                                          unsigned int r_type,
 413                                          Symbol* gsym);
 414
 415     inline bool
 416     possible_function_pointer_reloc(unsigned int r_type);
 417
 418     bool
 419     reloc_needs_plt_for_ifunc(Sized_relobj_file<32, false>*,
 420                               unsigned int r_type);
 421
 422     static void
 423     unsupported_reloc_local(Sized_relobj_file<32, false>*, unsigned int r_type);
 424
 425     static void
 426     unsupported_reloc_global(Sized_relobj_file<32, false>*, unsigned int r_type,
 427                              Symbol*);
 428   };
 429
 430   // The class which implements relocation.
 431   class Relocate
 432   {
 433    public:
 434     Relocate()
 435       : skip_call_tls_get_addr_(false),
 436         local_dynamic_type_(LOCAL_DYNAMIC_NONE)
 437     { }
 438
 439     ~Relocate()
 440     {
 441       if (this->skip_call_tls_get_addr_)
 442         {
 443           // FIXME: This needs to specify the location somehow.
 444           gold_error(_("missing expected TLS relocation"));
 445         }
 446     }
 447
 448     // Return whether the static relocation needs to be applied.
 449     inline bool
 450     should_apply_static_reloc(const Sized_symbol<32>* gsym,
 451                               unsigned int r_type,
 452                               bool is_32bit,
 453                               Output_section* output_section);
 454
 455     // Do a relocation.  Return false if the caller should not issue
 456     // any warnings about this relocation.
 457     inline bool
 458     relocate(const Relocate_info<32, false>*, Target_i386*, Output_section*,
 459              size_t relnum, const elfcpp::Rel<32, false>&,
 460              unsigned int r_type, const Sized_symbol<32>*,
 461              const Symbol_value<32>*,
 462              unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
 463              section_size_type);
 464
 465    private:
 466     // Do a TLS relocation.
 467     inline void
 468     relocate_tls(const Relocate_info<32, false>*, Target_i386* target,
 469                  size_t relnum, const elfcpp::Rel<32, false>&,
 470                  unsigned int r_type, const Sized_symbol<32>*,
 471                  const Symbol_value<32>*,
 472                  unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
 473                  section_size_type);
 474
 475     // Do a TLS General-Dynamic to Initial-Exec transition.
 476     inline void
 477     tls_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
 478                  Output_segment* tls_segment,
 479                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 480                  elfcpp::Elf_types<32>::Elf_Addr value,
 481                  unsigned char* view,
 482                  section_size_type view_size);
 483
 484     // Do a TLS General-Dynamic to Local-Exec transition.
 485     inline void
 486     tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
 487                  Output_segment* tls_segment,
 488                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 489                  elfcpp::Elf_types<32>::Elf_Addr value,
 490                  unsigned char* view,
 491                  section_size_type view_size);
 492
 493     // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
 494     // transition.
 495     inline void
 496     tls_desc_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
 497                       Output_segment* tls_segment,
 498                       const elfcpp::Rel<32, false>&, unsigned int r_type,
 499                       elfcpp::Elf_types<32>::Elf_Addr value,
 500                       unsigned char* view,
 501                       section_size_type view_size);
 502
 503     // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
 504     // transition.
 505     inline void
 506     tls_desc_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
 507                       Output_segment* tls_segment,
 508                       const elfcpp::Rel<32, false>&, unsigned int r_type,
 509                       elfcpp::Elf_types<32>::Elf_Addr value,
 510                       unsigned char* view,
 511                       section_size_type view_size);
 512
 513     // Do a TLS Local-Dynamic to Local-Exec transition.
 514     inline void
 515     tls_ld_to_le(const Relocate_info<32, false>*, size_t relnum,
 516                  Output_segment* tls_segment,
 517                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 518                  elfcpp::Elf_types<32>::Elf_Addr value,
 519                  unsigned char* view,
 520                  section_size_type view_size);
 521
 522     // Do a TLS Initial-Exec to Local-Exec transition.
 523     static inline void
 524     tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum,
 525                  Output_segment* tls_segment,
 526                  const elfcpp::Rel<32, false>&, unsigned int r_type,
 527                  elfcpp::Elf_types<32>::Elf_Addr value,
 528                  unsigned char* view,
 529                  section_size_type view_size);
 530
 531     // We need to keep track of which type of local dynamic relocation
 532     // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
 533     enum Local_dynamic_type
 534     {
 535       LOCAL_DYNAMIC_NONE,
 536       LOCAL_DYNAMIC_SUN,
 537       LOCAL_DYNAMIC_GNU
 538     };
 539
 540     // This is set if we should skip the next reloc, which should be a
 541     // PLT32 reloc against ___tls_get_addr.
 542     bool skip_call_tls_get_addr_;
 543     // The type of local dynamic relocation we have seen in the section
 544     // being relocated, if any.
 545     Local_dynamic_type local_dynamic_type_;
 546   };
 547
 548   // A class which returns the size required for a relocation type,
 549   // used while scanning relocs during a relocatable link.
 550   class Relocatable_size_for_reloc
 551   {
 552    public:
 553     unsigned int
 554     get_size_for_reloc(unsigned int, Relobj*);
 555   };
 556
 557   // Adjust TLS relocation type based on the options and whether this
 558   // is a local symbol.
 559   static tls::Tls_optimization
 560   optimize_tls_reloc(bool is_final, int r_type);
 561
 562   // Get the GOT section, creating it if necessary.
 563   Output_data_got<32, false>*
 564   got_section(Symbol_table*, Layout*);
 565
 566   // Get the GOT PLT section.
 567   Output_data_space*
 568   got_plt_section() const
 569   {
 570     gold_assert(this->got_plt_ != NULL);
 571     return this->got_plt_;
 572   }
 573
 574   // Get the GOT section for TLSDESC entries.
 575   Output_data_got<32, false>*
 576   got_tlsdesc_section() const
 577   {
 578     gold_assert(this->got_tlsdesc_ != NULL);
 579     return this->got_tlsdesc_;
 580   }
 581
 582   // Create the PLT section.
 583   void
 584   make_plt_section(Symbol_table* symtab, Layout* layout);
 585
 586   // Create a PLT entry for a global symbol.
 587   void
 588   make_plt_entry(Symbol_table*, Layout*, Symbol*);
 589
 590   // Create a PLT entry for a local STT_GNU_IFUNC symbol.
 591   void
 592   make_local_ifunc_plt_entry(Symbol_table*, Layout*,
 593                              Sized_relobj_file<32, false>* relobj,
 594                              unsigned int local_sym_index);
 595
 596   // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
 597   void
 598   define_tls_base_symbol(Symbol_table*, Layout*);
 599
 600   // Create a GOT entry for the TLS module index.
 601   unsigned int
 602   got_mod_index_entry(Symbol_table* symtab, Layout* layout,
 603                       Sized_relobj_file<32, false>* object);
 604
 605   // Get the PLT section.
 606   Output_data_plt_i386*
 607   plt_section() const
 608   {
 609     gold_assert(this->plt_ != NULL);
 610     return this->plt_;
 611   }
 612
 613   // Get the dynamic reloc section, creating it if necessary.
 614   Reloc_section*
 615   rel_dyn_section(Layout*);
 616
 617   // Get the section to use for TLS_DESC relocations.
 618   Reloc_section*
 619   rel_tls_desc_section(Layout*) const;
 620
 621   // Get the section to use for IRELATIVE relocations.
 622   Reloc_section*
 623   rel_irelative_section(Layout*);
 624
 625   // Add a potential copy relocation.
 626   void
 627   copy_reloc(Symbol_table* symtab, Layout* layout,
 628              Sized_relobj_file<32, false>* object,
 629              unsigned int shndx, Output_section* output_section,
 630              Symbol* sym, const elfcpp::Rel<32, false>& reloc)
 631   {
 632     this->copy_relocs_.copy_reloc(symtab, layout,
 633                                   symtab->get_sized_symbol<32>(sym),
 634                                   object, shndx, output_section, reloc,
 635                                   this->rel_dyn_section(layout));
 636   }
 637
 638   // Information about this specific target which we pass to the
 639   // general Target structure.
 640   static const Target::Target_info i386_info;
 641
 642   // The types of GOT entries needed for this platform.
 643   // These values are exposed to the ABI in an incremental link.
 644   // Do not renumber existing values without changing the version
 645   // number of the .gnu_incremental_inputs section.
 646   enum Got_type
 647   {
 648     GOT_TYPE_STANDARD = 0,      // GOT entry for a regular symbol
 649     GOT_TYPE_TLS_NOFFSET = 1,   // GOT entry for negative TLS offset
 650     GOT_TYPE_TLS_OFFSET = 2,    // GOT entry for positive TLS offset
 651     GOT_TYPE_TLS_PAIR = 3,      // GOT entry for TLS module/offset pair
 652     GOT_TYPE_TLS_DESC = 4       // GOT entry for TLS_DESC pair
 653   };
 654
 655   // The GOT section.
 656   Output_data_got<32, false>* got_;
 657   // The PLT section.
 658   Output_data_plt_i386* plt_;
 659   // The GOT PLT section.
 660   Output_data_space* got_plt_;
 661   // The GOT section for IRELATIVE relocations.
 662   Output_data_space* got_irelative_;
 663   // The GOT section for TLSDESC relocations.
 664   Output_data_got<32, false>* got_tlsdesc_;
 665   // The _GLOBAL_OFFSET_TABLE_ symbol.
 666   Symbol* global_offset_table_;
 667   // The dynamic reloc section.
 668   Reloc_section* rel_dyn_;
 669   // The section to use for IRELATIVE relocs.
 670   Reloc_section* rel_irelative_;
 671   // Relocs saved to avoid a COPY reloc.
 672   Copy_relocs<elfcpp::SHT_REL, 32, false> copy_relocs_;
 673   // Space for variables copied with a COPY reloc.
 674   Output_data_space* dynbss_;
 675   // Offset of the GOT entry for the TLS module index.
 676   unsigned int got_mod_index_offset_;
 677   // True if the _TLS_MODULE_BASE_ symbol has been defined.
 678   bool tls_base_symbol_defined_;
 679 };
 680
 681 const Target::Target_info Target_i386::i386_info =
 682 {
 683   32,                   // size
 684   false,                // is_big_endian
 685   elfcpp::EM_386,       // machine_code
 686   false,                // has_make_symbol
 687   false,                // has_resolve
 688   true,                 // has_code_fill
 689   true,                 // is_default_stack_executable
 690   true,                 // can_icf_inline_merge_sections
 691   '\0',                 // wrap_char
 692   "/usr/lib/libc.so.1", // dynamic_linker
 693   0x08048000,           // default_text_segment_address
 694   0x1000,               // abi_pagesize (overridable by -z max-page-size)
 695   0x1000,               // common_pagesize (overridable by -z common-page-size)
 696   elfcpp::SHN_UNDEF,    // small_common_shndx
 697   elfcpp::SHN_UNDEF,    // large_common_shndx
 698   0,                    // small_common_section_flags
 699   0,                    // large_common_section_flags
 700   NULL,                 // attributes_section
 701   NULL                  // attributes_vendor
 702 };
 703
 704 // Get the GOT section, creating it if necessary.
 705
 706 Output_data_got<32, false>*
 707 Target_i386::got_section(Symbol_table* symtab, Layout* layout)
 708 {
 709   if (this->got_ == NULL)
 710     {
 711       gold_assert(symtab != NULL && layout != NULL);
 712
 713       this->got_ = new Output_data_got<32, false>();
 714
 715       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
 716                                       (elfcpp::SHF_ALLOC
 717                                        | elfcpp::SHF_WRITE),
 718                                       this->got_, ORDER_RELRO_LAST, true);
 719
 720       this->got_plt_ = new Output_data_space(4, "** GOT PLT");
 721       layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
 722                                       (elfcpp::SHF_ALLOC
 723                                        | elfcpp::SHF_WRITE),
 724                                       this->got_plt_, ORDER_NON_RELRO_FIRST,
 725                                       false);
 726
 727       // The first three entries are reserved.
 728       this->got_plt_->set_current_data_size(3 * 4);
 729
 730       // Those bytes can go into the relro segment.
 731       layout->increase_relro(3 * 4);
 732
 733       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
 734       this->global_offset_table_ =
 735         symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
 736                                       Symbol_table::PREDEFINED,
 737                                       this->got_plt_,
 738                                       0, 0, elfcpp::STT_OBJECT,
 739                                       elfcpp::STB_LOCAL,
 740                                       elfcpp::STV_HIDDEN, 0,
 741                                       false, false);
 742
 743       // If there are any IRELATIVE relocations, they get GOT entries
 744       // in .got.plt after the jump slot relocations.
 745       this->got_irelative_ = new Output_data_space(4, "** GOT IRELATIVE PLT");
 746       layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
 747                                       (elfcpp::SHF_ALLOC
 748                                        | elfcpp::SHF_WRITE),
 749                                       this->got_irelative_,
 750                                       ORDER_NON_RELRO_FIRST, false);
 751
 752       // If there are any TLSDESC relocations, they get GOT entries in
 753       // .got.plt after the jump slot entries.
 754       this->got_tlsdesc_ = new Output_data_got<32, false>();
 755       layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
 756                                       (elfcpp::SHF_ALLOC
 757                                        | elfcpp::SHF_WRITE),
 758                                       this->got_tlsdesc_,
 759                                       ORDER_NON_RELRO_FIRST, false);
 760     }
 761
 762   return this->got_;
 763 }
 764
 765 // Get the dynamic reloc section, creating it if necessary.
 766
 767 Target_i386::Reloc_section*
 768 Target_i386::rel_dyn_section(Layout* layout)
 769 {
 770   if (this->rel_dyn_ == NULL)
 771     {
 772       gold_assert(layout != NULL);
 773       this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
 774       layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
 775                                       elfcpp::SHF_ALLOC, this->rel_dyn_,
 776                                       ORDER_DYNAMIC_RELOCS, false);
 777     }
 778   return this->rel_dyn_;
 779 }
 780
 781 // Get the section to use for IRELATIVE relocs, creating it if
 782 // necessary.  These go in .rel.dyn, but only after all other dynamic
 783 // relocations.  They need to follow the other dynamic relocations so
 784 // that they can refer to global variables initialized by those
 785 // relocs.
 786
 787 Target_i386::Reloc_section*
 788 Target_i386::rel_irelative_section(Layout* layout)
 789 {
 790   if (this->rel_irelative_ == NULL)
 791     {
 792       // Make sure we have already create the dynamic reloc section.
 793       this->rel_dyn_section(layout);
 794       this->rel_irelative_ = new Reloc_section(false);
 795       layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
 796                                       elfcpp::SHF_ALLOC, this->rel_irelative_,
 797                                       ORDER_DYNAMIC_RELOCS, false);
 798       gold_assert(this->rel_dyn_->output_section()
 799                   == this->rel_irelative_->output_section());
 800     }
 801   return this->rel_irelative_;
 802 }
 803
 804 // Create the PLT section.  The ordinary .got section is an argument,
 805 // since we need to refer to the start.  We also create our own .got
 806 // section just for PLT entries.
 807
 808 Output_data_plt_i386::Output_data_plt_i386(Layout* layout,
 809                                            Output_data_space* got_plt,
 810                                            Output_data_space* got_irelative)
 811   : Output_section_data(16), tls_desc_rel_(NULL), irelative_rel_(NULL),
 812     got_plt_(got_plt), got_irelative_(got_irelative), count_(0),
 813     irelative_count_(0), global_ifuncs_(), local_ifuncs_()
 814 {
 815   this->rel_ = new Reloc_section(false);
 816   layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
 817                                   elfcpp::SHF_ALLOC, this->rel_,
 818                                   ORDER_DYNAMIC_PLT_RELOCS, false);
 819
 820   // Add unwind information if requested.
 821   if (parameters->options().ld_generated_unwind_info())
 822     layout->add_eh_frame_for_plt(this, plt_eh_frame_cie, plt_eh_frame_cie_size,
 823                                  plt_eh_frame_fde, plt_eh_frame_fde_size);
 824 }
 825
 826 void
 827 Output_data_plt_i386::do_adjust_output_section(Output_section* os)
 828 {
 829   // UnixWare sets the entsize of .plt to 4, and so does the old GNU
 830   // linker, and so do we.
 831   os->set_entsize(4);
 832 }
 833
 834 // Add an entry to the PLT.
 835
 836 void
 837 Output_data_plt_i386::add_entry(Symbol_table* symtab, Layout* layout,
 838                                 Symbol* gsym)
 839 {
 840   gold_assert(!gsym->has_plt_offset());
 841
 842   // Every PLT entry needs a reloc.
 843   if (gsym->type() == elfcpp::STT_GNU_IFUNC
 844       && gsym->can_use_relative_reloc(false))
 845     {
 846       gsym->set_plt_offset(this->irelative_count_ * plt_entry_size);
 847       ++this->irelative_count_;
 848       section_offset_type got_offset =
 849         this->got_irelative_->current_data_size();
 850       this->got_irelative_->set_current_data_size(got_offset + 4);
 851       Reloc_section* rel = this->rel_irelative(symtab, layout);
 852       rel->add_symbolless_global_addend(gsym, elfcpp::R_386_IRELATIVE,
 853                                         this->got_irelative_, got_offset);
 854       struct Global_ifunc gi;
 855       gi.sym = gsym;
 856       gi.got_offset = got_offset;
 857       this->global_ifuncs_.push_back(gi);
 858     }
 859   else
 860     {
 861       // When setting the PLT offset we skip the initial reserved PLT
 862       // entry.
 863       gsym->set_plt_offset((this->count_ + 1) * plt_entry_size);
 864
 865       ++this->count_;
 866
 867       section_offset_type got_offset = this->got_plt_->current_data_size();
 868
 869       // Every PLT entry needs a GOT entry which points back to the
 870       // PLT entry (this will be changed by the dynamic linker,
 871       // normally lazily when the function is called).
 872       this->got_plt_->set_current_data_size(got_offset + 4);
 873
 874       gsym->set_needs_dynsym_entry();
 875       this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_,
 876                              got_offset);
 877     }
 878
 879   // Note that we don't need to save the symbol.  The contents of the
 880   // PLT are independent of which symbols are used.  The symbols only
 881   // appear in the relocations.
 882 }
 883
 884 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.  Return
 885 // the PLT offset.
 886
 887 unsigned int
 888 Output_data_plt_i386::add_local_ifunc_entry(
 889     Symbol_table* symtab,
 890     Layout* layout,
 891     Sized_relobj_file<32, false>* relobj,
 892     unsigned int local_sym_index)
 893 {
 894   unsigned int plt_offset = this->irelative_count_ * plt_entry_size;
 895   ++this->irelative_count_;
 896
 897   section_offset_type got_offset = this->got_irelative_->current_data_size();
 898
 899   // Every PLT entry needs a GOT entry which points back to the PLT
 900   // entry.
 901   this->got_irelative_->set_current_data_size(got_offset + 4);
 902
 903   // Every PLT entry needs a reloc.
 904   Reloc_section* rel = this->rel_irelative(symtab, layout);
 905   rel->add_symbolless_local_addend(relobj, local_sym_index,
 906                                    elfcpp::R_386_IRELATIVE,
 907                                    this->got_irelative_, got_offset);
 908
 909   struct Local_ifunc li;
 910   li.object = relobj;
 911   li.local_sym_index = local_sym_index;
 912   li.got_offset = got_offset;
 913   this->local_ifuncs_.push_back(li);
 914
 915   return plt_offset;
 916 }
 917
 918 // Return where the TLS_DESC relocations should go, creating it if
 919 // necessary. These follow the JUMP_SLOT relocations.
 920
 921 Output_data_plt_i386::Reloc_section*
 922 Output_data_plt_i386::rel_tls_desc(Layout* layout)
 923 {
 924   if (this->tls_desc_rel_ == NULL)
 925     {
 926       this->tls_desc_rel_ = new Reloc_section(false);
 927       layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
 928                                       elfcpp::SHF_ALLOC, this->tls_desc_rel_,
 929                                       ORDER_DYNAMIC_PLT_RELOCS, false);
 930       gold_assert(this->tls_desc_rel_->output_section()
 931                   == this->rel_->output_section());
 932     }
 933   return this->tls_desc_rel_;
 934 }
 935
 936 // Return where the IRELATIVE relocations should go in the PLT.  These
 937 // follow the JUMP_SLOT and TLS_DESC relocations.
 938
 939 Output_data_plt_i386::Reloc_section*
 940 Output_data_plt_i386::rel_irelative(Symbol_table* symtab, Layout* layout)
 941 {
 942   if (this->irelative_rel_ == NULL)
 943     {
 944       // Make sure we have a place for the TLS_DESC relocations, in
 945       // case we see any later on.
 946       this->rel_tls_desc(layout);
 947       this->irelative_rel_ = new Reloc_section(false);
 948       layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
 949                                       elfcpp::SHF_ALLOC, this->irelative_rel_,
 950                                       ORDER_DYNAMIC_PLT_RELOCS, false);
 951       gold_assert(this->irelative_rel_->output_section()
 952                   == this->rel_->output_section());
 953
 954       if (parameters->doing_static_link())
 955         {
 956           // A statically linked executable will only have a .rel.plt
 957           // section to hold R_386_IRELATIVE relocs for STT_GNU_IFUNC
 958           // symbols.  The library will use these symbols to locate
 959           // the IRELATIVE relocs at program startup time.
 960           symtab->define_in_output_data("__rel_iplt_start", NULL,
 961                                         Symbol_table::PREDEFINED,
 962                                         this->irelative_rel_, 0, 0,
 963                                         elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
 964                                         elfcpp::STV_HIDDEN, 0, false, true);
 965           symtab->define_in_output_data("__rel_iplt_end", NULL,
 966                                         Symbol_table::PREDEFINED,
 967                                         this->irelative_rel_, 0, 0,
 968                                         elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
 969                                         elfcpp::STV_HIDDEN, 0, true, true);
 970         }
 971     }
 972   return this->irelative_rel_;
 973 }
 974
 975 // Return the PLT address to use for a global symbol.
 976
 977 uint64_t
 978 Output_data_plt_i386::address_for_global(const Symbol* gsym)
 979 {
 980   uint64_t offset = 0;
 981   if (gsym->type() == elfcpp::STT_GNU_IFUNC
 982       && gsym->can_use_relative_reloc(false))
 983     offset = (this->count_ + 1) * plt_entry_size;
 984   return this->address() + offset;
 985 }
 986
 987 // Return the PLT address to use for a local symbol.  These are always
 988 // IRELATIVE relocs.
 989
 990 uint64_t
 991 Output_data_plt_i386::address_for_local(const Relobj*, unsigned int)
 992 {
 993   return this->address() + (this->count_ + 1) * plt_entry_size;
 994 }
 995
 996 // The first entry in the PLT for an executable.
 997
 998 const unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] =
 999 {
1000   0xff, 0x35,   // pushl contents of memory address
1001   0, 0, 0, 0,   // replaced with address of .got + 4
1002   0xff, 0x25,   // jmp indirect
1003   0, 0, 0, 0,   // replaced with address of .got + 8
1004   0, 0, 0, 0    // unused
1005 };
1006
1007 // The first entry in the PLT for a shared object.
1008
1009 const unsigned char Output_data_plt_i386::dyn_first_plt_entry[plt_entry_size] =
1010 {
1011   0xff, 0xb3, 4, 0, 0, 0,       // pushl 4(%ebx)
1012   0xff, 0xa3, 8, 0, 0, 0,       // jmp *8(%ebx)
1013   0, 0, 0, 0                    // unused
1014 };
1015
1016 // Subsequent entries in the PLT for an executable.
1017
1018 const unsigned char Output_data_plt_i386::exec_plt_entry[plt_entry_size] =
1019 {
1020   0xff, 0x25,   // jmp indirect
1021   0, 0, 0, 0,   // replaced with address of symbol in .got
1022   0x68,         // pushl immediate
1023   0, 0, 0, 0,   // replaced with offset into relocation table
1024   0xe9,         // jmp relative
1025   0, 0, 0, 0    // replaced with offset to start of .plt
1026 };
1027
1028 // Subsequent entries in the PLT for a shared object.
1029
1030 const unsigned char Output_data_plt_i386::dyn_plt_entry[plt_entry_size] =
1031 {
1032   0xff, 0xa3,   // jmp *offset(%ebx)
1033   0, 0, 0, 0,   // replaced with offset of symbol in .got
1034   0x68,         // pushl immediate
1035   0, 0, 0, 0,   // replaced with offset into relocation table
1036   0xe9,         // jmp relative
1037   0, 0, 0, 0    // replaced with offset to start of .plt
1038 };
1039
1040 // The .eh_frame unwind information for the PLT.
1041
1042 const unsigned char
1043 Output_data_plt_i386::plt_eh_frame_cie[plt_eh_frame_cie_size] =
1044 {
1045   1,                            // CIE version.
1046   'z',                          // Augmentation: augmentation size included.
1047   'R',                          // Augmentation: FDE encoding included.
1048   '\0',                         // End of augmentation string.
1049   1,                            // Code alignment factor.
1050   0x7c,                         // Data alignment factor.
1051   8,                            // Return address column.
1052   1,                            // Augmentation size.
1053   (elfcpp::DW_EH_PE_pcrel       // FDE encoding.
1054    | elfcpp::DW_EH_PE_sdata4),
1055   elfcpp::DW_CFA_def_cfa, 4, 4, // DW_CFA_def_cfa: r4 (esp) ofs 4.
1056   elfcpp::DW_CFA_offset + 8, 1, // DW_CFA_offset: r8 (eip) at cfa-4.
1057   elfcpp::DW_CFA_nop,           // Align to 16 bytes.
1058   elfcpp::DW_CFA_nop
1059 };
1060
1061 const unsigned char
1062 Output_data_plt_i386::plt_eh_frame_fde[plt_eh_frame_fde_size] =
1063 {
1064   0, 0, 0, 0,                           // Replaced with offset to .plt.
1065   0, 0, 0, 0,                           // Replaced with size of .plt.
1066   0,                                    // Augmentation size.
1067   elfcpp::DW_CFA_def_cfa_offset, 8,     // DW_CFA_def_cfa_offset: 8.
1068   elfcpp::DW_CFA_advance_loc + 6,       // Advance 6 to __PLT__ + 6.
1069   elfcpp::DW_CFA_def_cfa_offset, 12,    // DW_CFA_def_cfa_offset: 12.
1070   elfcpp::DW_CFA_advance_loc + 10,      // Advance 10 to __PLT__ + 16.
1071   elfcpp::DW_CFA_def_cfa_expression,    // DW_CFA_def_cfa_expression.
1072   11,                                   // Block length.
1073   elfcpp::DW_OP_breg4, 4,               // Push %esp + 4.
1074   elfcpp::DW_OP_breg8, 0,               // Push %eip.
1075   elfcpp::DW_OP_lit15,                  // Push 0xf.
1076   elfcpp::DW_OP_and,                    // & (%eip & 0xf).
1077   elfcpp::DW_OP_lit11,                  // Push 0xb.
1078   elfcpp::DW_OP_ge,                     // >= ((%eip & 0xf) >= 0xb)
1079   elfcpp::DW_OP_lit2,                   // Push 2.
1080   elfcpp::DW_OP_shl,                    // << (((%eip & 0xf) >= 0xb) << 2)
1081   elfcpp::DW_OP_plus,                   // + ((((%eip&0xf)>=0xb)<<2)+%esp+4
1082   elfcpp::DW_CFA_nop,                   // Align to 32 bytes.
1083   elfcpp::DW_CFA_nop,
1084   elfcpp::DW_CFA_nop,
1085   elfcpp::DW_CFA_nop
1086 };
1087
1088 // Write out the PLT.  This uses the hand-coded instructions above,
1089 // and adjusts them as needed.  This is all specified by the i386 ELF
1090 // Processor Supplement.
1091
1092 void
1093 Output_data_plt_i386::do_write(Output_file* of)
1094 {
1095   const off_t offset = this->offset();
1096   const section_size_type oview_size =
1097     convert_to_section_size_type(this->data_size());
1098   unsigned char* const oview = of->get_output_view(offset, oview_size);
1099
1100   const off_t got_file_offset = this->got_plt_->offset();
1101   gold_assert(parameters->incremental_update()
1102               || (got_file_offset + this->got_plt_->data_size()
1103                   == this->got_irelative_->offset()));
1104   const section_size_type got_size =
1105     convert_to_section_size_type(this->got_plt_->data_size()
1106                                  + this->got_irelative_->data_size());
1107   unsigned char* const got_view = of->get_output_view(got_file_offset,
1108                                                       got_size);
1109
1110   unsigned char* pov = oview;
1111
1112   elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address();
1113   elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address();
1114
1115   if (parameters->options().output_is_position_independent())
1116     memcpy(pov, dyn_first_plt_entry, plt_entry_size);
1117   else
1118     {
1119       memcpy(pov, exec_first_plt_entry, plt_entry_size);
1120       elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
1121       elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
1122     }
1123   pov += plt_entry_size;
1124
1125   unsigned char* got_pov = got_view;
1126
1127   memset(got_pov, 0, 12);
1128   got_pov += 12;
1129
1130   const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
1131
1132   unsigned int plt_offset = plt_entry_size;
1133   unsigned int plt_rel_offset = 0;
1134   unsigned int got_offset = 12;
1135   const unsigned int count = this->count_ + this->irelative_count_;
1136   for (unsigned int i = 0;
1137        i < count;
1138        ++i,
1139          pov += plt_entry_size,
1140          got_pov += 4,
1141          plt_offset += plt_entry_size,
1142          plt_rel_offset += rel_size,
1143          got_offset += 4)
1144     {
1145       // Set and adjust the PLT entry itself.
1146
1147       if (parameters->options().output_is_position_independent())
1148         {
1149           memcpy(pov, dyn_plt_entry, plt_entry_size);
1150           elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
1151         }
1152       else
1153         {
1154           memcpy(pov, exec_plt_entry, plt_entry_size);
1155           elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1156                                                       (got_address
1157                                                        + got_offset));
1158         }
1159
1160       elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
1161       elfcpp::Swap<32, false>::writeval(pov + 12,
1162                                         - (plt_offset + plt_entry_size));
1163
1164       // Set the entry in the GOT.
1165       elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6);
1166     }
1167
1168   // If any STT_GNU_IFUNC symbols have PLT entries, we need to change
1169   // the GOT to point to the actual symbol value, rather than point to
1170   // the PLT entry.  That will let the dynamic linker call the right
1171   // function when resolving IRELATIVE relocations.
1172   unsigned char* got_irelative_view = got_view + this->got_plt_->data_size();
1173   for (std::vector<Global_ifunc>::const_iterator p =
1174          this->global_ifuncs_.begin();
1175        p != this->global_ifuncs_.end();
1176        ++p)
1177     {
1178       const Sized_symbol<32>* ssym =
1179         static_cast<const Sized_symbol<32>*>(p->sym);
1180       elfcpp::Swap<32, false>::writeval(got_irelative_view + p->got_offset,
1181                                         ssym->value());
1182     }
1183
1184   for (std::vector<Local_ifunc>::const_iterator p =
1185          this->local_ifuncs_.begin();
1186        p != this->local_ifuncs_.end();
1187        ++p)
1188     {
1189       const Symbol_value<32>* psymval =
1190         p->object->local_symbol(p->local_sym_index);
1191       elfcpp::Swap<32, false>::writeval(got_irelative_view + p->got_offset,
1192                                         psymval->value(p->object, 0));
1193     }
1194
1195   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
1196   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
1197
1198   of->write_output_view(offset, oview_size, oview);
1199   of->write_output_view(got_file_offset, got_size, got_view);
1200 }
1201
1202 // Create the PLT section.
1203
1204 void
1205 Target_i386::make_plt_section(Symbol_table* symtab, Layout* layout)
1206 {
1207   if (this->plt_ == NULL)
1208     {
1209       // Create the GOT sections first.
1210       this->got_section(symtab, layout);
1211
1212       this->plt_ = new Output_data_plt_i386(layout, this->got_plt_,
1213                                             this->got_irelative_);
1214       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
1215                                       (elfcpp::SHF_ALLOC
1216                                        | elfcpp::SHF_EXECINSTR),
1217                                       this->plt_, ORDER_PLT, false);
1218
1219       // Make the sh_info field of .rel.plt point to .plt.
1220       Output_section* rel_plt_os = this->plt_->rel_plt()->output_section();
1221       rel_plt_os->set_info_section(this->plt_->output_section());
1222     }
1223 }
1224
1225 // Create a PLT entry for a global symbol.
1226
1227 void
1228 Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym)
1229 {
1230   if (gsym->has_plt_offset())
1231     return;
1232   if (this->plt_ == NULL)
1233     this->make_plt_section(symtab, layout);
1234   this->plt_->add_entry(symtab, layout, gsym);
1235 }
1236
1237 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1238
1239 void
1240 Target_i386::make_local_ifunc_plt_entry(Symbol_table* symtab, Layout* layout,
1241                                         Sized_relobj_file<32, false>* relobj,
1242                                         unsigned int local_sym_index)
1243 {
1244   if (relobj->local_has_plt_offset(local_sym_index))
1245     return;
1246   if (this->plt_ == NULL)
1247     this->make_plt_section(symtab, layout);
1248   unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout,
1249                                                               relobj,
1250                                                               local_sym_index);
1251   relobj->set_local_plt_offset(local_sym_index, plt_offset);
1252 }
1253
1254 // Return the number of entries in the PLT.
1255
1256 unsigned int
1257 Target_i386::plt_entry_count() const
1258 {
1259   if (this->plt_ == NULL)
1260     return 0;
1261   return this->plt_->entry_count();
1262 }
1263
1264 // Return the offset of the first non-reserved PLT entry.
1265
1266 unsigned int
1267 Target_i386::first_plt_entry_offset() const
1268 {
1269   return Output_data_plt_i386::first_plt_entry_offset();
1270 }
1271
1272 // Return the size of each PLT entry.
1273
1274 unsigned int
1275 Target_i386::plt_entry_size() const
1276 {
1277   return Output_data_plt_i386::get_plt_entry_size();
1278 }
1279
1280 // Get the section to use for TLS_DESC relocations.
1281
1282 Target_i386::Reloc_section*
1283 Target_i386::rel_tls_desc_section(Layout* layout) const
1284 {
1285   return this->plt_section()->rel_tls_desc(layout);
1286 }
1287
1288 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1289
1290 void
1291 Target_i386::define_tls_base_symbol(Symbol_table* symtab, Layout* layout)
1292 {
1293   if (this->tls_base_symbol_defined_)
1294     return;
1295
1296   Output_segment* tls_segment = layout->tls_segment();
1297   if (tls_segment != NULL)
1298     {
1299       bool is_exec = parameters->options().output_is_executable();
1300       symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
1301                                        Symbol_table::PREDEFINED,
1302                                        tls_segment, 0, 0,
1303                                        elfcpp::STT_TLS,
1304                                        elfcpp::STB_LOCAL,
1305                                        elfcpp::STV_HIDDEN, 0,
1306                                        (is_exec
1307                                         ? Symbol::SEGMENT_END
1308                                         : Symbol::SEGMENT_START),
1309                                        true);
1310     }
1311   this->tls_base_symbol_defined_ = true;
1312 }
1313
1314 // Create a GOT entry for the TLS module index.
1315
1316 unsigned int
1317 Target_i386::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
1318                                  Sized_relobj_file<32, false>* object)
1319 {
1320   if (this->got_mod_index_offset_ == -1U)
1321     {
1322       gold_assert(symtab != NULL && layout != NULL && object != NULL);
1323       Reloc_section* rel_dyn = this->rel_dyn_section(layout);
1324       Output_data_got<32, false>* got = this->got_section(symtab, layout);
1325       unsigned int got_offset = got->add_constant(0);
1326       rel_dyn->add_local(object, 0, elfcpp::R_386_TLS_DTPMOD32, got,
1327                          got_offset);
1328       got->add_constant(0);
1329       this->got_mod_index_offset_ = got_offset;
1330     }
1331   return this->got_mod_index_offset_;
1332 }
1333
1334 // Optimize the TLS relocation type based on what we know about the
1335 // symbol.  IS_FINAL is true if the final address of this symbol is
1336 // known at link time.
1337
1338 tls::Tls_optimization
1339 Target_i386::optimize_tls_reloc(bool is_final, int r_type)
1340 {
1341   // If we are generating a shared library, then we can't do anything
1342   // in the linker.
1343   if (parameters->options().shared())
1344     return tls::TLSOPT_NONE;
1345
1346   switch (r_type)
1347     {
1348     case elfcpp::R_386_TLS_GD:
1349     case elfcpp::R_386_TLS_GOTDESC:
1350     case elfcpp::R_386_TLS_DESC_CALL:
1351       // These are General-Dynamic which permits fully general TLS
1352       // access.  Since we know that we are generating an executable,
1353       // we can convert this to Initial-Exec.  If we also know that
1354       // this is a local symbol, we can further switch to Local-Exec.
1355       if (is_final)
1356         return tls::TLSOPT_TO_LE;
1357       return tls::TLSOPT_TO_IE;
1358
1359     case elfcpp::R_386_TLS_LDM:
1360       // This is Local-Dynamic, which refers to a local symbol in the
1361       // dynamic TLS block.  Since we know that we generating an
1362       // executable, we can switch to Local-Exec.
1363       return tls::TLSOPT_TO_LE;
1364
1365     case elfcpp::R_386_TLS_LDO_32:
1366       // Another type of Local-Dynamic relocation.
1367       return tls::TLSOPT_TO_LE;
1368
1369     case elfcpp::R_386_TLS_IE:
1370     case elfcpp::R_386_TLS_GOTIE:
1371     case elfcpp::R_386_TLS_IE_32:
1372       // These are Initial-Exec relocs which get the thread offset
1373       // from the GOT.  If we know that we are linking against the
1374       // local symbol, we can switch to Local-Exec, which links the
1375       // thread offset into the instruction.
1376       if (is_final)
1377         return tls::TLSOPT_TO_LE;
1378       return tls::TLSOPT_NONE;
1379
1380     case elfcpp::R_386_TLS_LE:
1381     case elfcpp::R_386_TLS_LE_32:
1382       // When we already have Local-Exec, there is nothing further we
1383       // can do.
1384       return tls::TLSOPT_NONE;
1385
1386     default:
1387       gold_unreachable();
1388     }
1389 }
1390
1391 // Get the Reference_flags for a particular relocation.
1392
1393 int
1394 Target_i386::Scan::get_reference_flags(unsigned int r_type)
1395 {
1396   switch (r_type)
1397     {
1398     case elfcpp::R_386_NONE:
1399     case elfcpp::R_386_GNU_VTINHERIT:
1400     case elfcpp::R_386_GNU_VTENTRY:
1401     case elfcpp::R_386_GOTPC:
1402       // No symbol reference.
1403       return 0;
1404
1405     case elfcpp::R_386_32:
1406     case elfcpp::R_386_16:
1407     case elfcpp::R_386_8:
1408       return Symbol::ABSOLUTE_REF;
1409
1410     case elfcpp::R_386_PC32:
1411     case elfcpp::R_386_PC16:
1412     case elfcpp::R_386_PC8:
1413     case elfcpp::R_386_GOTOFF:
1414       return Symbol::RELATIVE_REF;
1415
1416     case elfcpp::R_386_PLT32:
1417       return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
1418
1419     case elfcpp::R_386_GOT32:
1420       // Absolute in GOT.
1421       return Symbol::ABSOLUTE_REF;
1422
1423     case elfcpp::R_386_TLS_GD:            // Global-dynamic
1424     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
1425     case elfcpp::R_386_TLS_DESC_CALL:
1426     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
1427     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
1428     case elfcpp::R_386_TLS_IE:            // Initial-exec
1429     case elfcpp::R_386_TLS_IE_32:
1430     case elfcpp::R_386_TLS_GOTIE:
1431     case elfcpp::R_386_TLS_LE:            // Local-exec
1432     case elfcpp::R_386_TLS_LE_32:
1433       return Symbol::TLS_REF;
1434
1435     case elfcpp::R_386_COPY:
1436     case elfcpp::R_386_GLOB_DAT:
1437     case elfcpp::R_386_JUMP_SLOT:
1438     case elfcpp::R_386_RELATIVE:
1439     case elfcpp::R_386_IRELATIVE:
1440     case elfcpp::R_386_TLS_TPOFF:
1441     case elfcpp::R_386_TLS_DTPMOD32:
1442     case elfcpp::R_386_TLS_DTPOFF32:
1443     case elfcpp::R_386_TLS_TPOFF32:
1444     case elfcpp::R_386_TLS_DESC:
1445     case elfcpp::R_386_32PLT:
1446     case elfcpp::R_386_TLS_GD_32:
1447     case elfcpp::R_386_TLS_GD_PUSH:
1448     case elfcpp::R_386_TLS_GD_CALL:
1449     case elfcpp::R_386_TLS_GD_POP:
1450     case elfcpp::R_386_TLS_LDM_32:
1451     case elfcpp::R_386_TLS_LDM_PUSH:
1452     case elfcpp::R_386_TLS_LDM_CALL:
1453     case elfcpp::R_386_TLS_LDM_POP:
1454     case elfcpp::R_386_USED_BY_INTEL_200:
1455     default:
1456       // Not expected.  We will give an error later.
1457       return 0;
1458     }
1459 }
1460
1461 // Report an unsupported relocation against a local symbol.
1462
1463 void
1464 Target_i386::Scan::unsupported_reloc_local(Sized_relobj_file<32, false>* object,
1465                                            unsigned int r_type)
1466 {
1467   gold_error(_("%s: unsupported reloc %u against local symbol"),
1468              object->name().c_str(), r_type);
1469 }
1470
1471 // Return whether we need to make a PLT entry for a relocation of a
1472 // given type against a STT_GNU_IFUNC symbol.
1473
1474 bool
1475 Target_i386::Scan::reloc_needs_plt_for_ifunc(
1476     Sized_relobj_file<32, false>* object,
1477     unsigned int r_type)
1478 {
1479   int flags = Scan::get_reference_flags(r_type);
1480   if (flags & Symbol::TLS_REF)
1481     gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
1482                object->name().c_str(), r_type);
1483   return flags != 0;
1484 }
1485
1486 // Scan a relocation for a local symbol.
1487
1488 inline void
1489 Target_i386::Scan::local(Symbol_table* symtab,
1490                          Layout* layout,
1491                          Target_i386* target,
1492                          Sized_relobj_file<32, false>* object,
1493                          unsigned int data_shndx,
1494                          Output_section* output_section,
1495                          const elfcpp::Rel<32, false>& reloc,
1496                          unsigned int r_type,
1497                          const elfcpp::Sym<32, false>& lsym)
1498 {
1499   // A local STT_GNU_IFUNC symbol may require a PLT entry.
1500   if (lsym.get_st_type() == elfcpp::STT_GNU_IFUNC
1501       && this->reloc_needs_plt_for_ifunc(object, r_type))
1502     {
1503       unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1504       target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
1505     }
1506
1507   switch (r_type)
1508     {
1509     case elfcpp::R_386_NONE:
1510     case elfcpp::R_386_GNU_VTINHERIT:
1511     case elfcpp::R_386_GNU_VTENTRY:
1512       break;
1513
1514     case elfcpp::R_386_32:
1515       // If building a shared library (or a position-independent
1516       // executable), we need to create a dynamic relocation for
1517       // this location. The relocation applied at link time will
1518       // apply the link-time value, so we flag the location with
1519       // an R_386_RELATIVE relocation so the dynamic loader can
1520       // relocate it easily.
1521       if (parameters->options().output_is_position_independent())
1522         {
1523           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1524           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1525           rel_dyn->add_local_relative(object, r_sym, elfcpp::R_386_RELATIVE,
1526                                       output_section, data_shndx,
1527                                       reloc.get_r_offset());
1528         }
1529       break;
1530
1531     case elfcpp::R_386_16:
1532     case elfcpp::R_386_8:
1533       // If building a shared library (or a position-independent
1534       // executable), we need to create a dynamic relocation for
1535       // this location. Because the addend needs to remain in the
1536       // data section, we need to be careful not to apply this
1537       // relocation statically.
1538       if (parameters->options().output_is_position_independent())
1539         {
1540           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1541           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1542           if (lsym.get_st_type() != elfcpp::STT_SECTION)
1543             rel_dyn->add_local(object, r_sym, r_type, output_section,
1544                                data_shndx, reloc.get_r_offset());
1545           else
1546             {
1547               gold_assert(lsym.get_st_value() == 0);
1548               unsigned int shndx = lsym.get_st_shndx();
1549               bool is_ordinary;
1550               shndx = object->adjust_sym_shndx(r_sym, shndx,
1551                                                &is_ordinary);
1552               if (!is_ordinary)
1553                 object->error(_("section symbol %u has bad shndx %u"),
1554                               r_sym, shndx);
1555               else
1556                 rel_dyn->add_local_section(object, shndx,
1557                                            r_type, output_section,
1558                                            data_shndx, reloc.get_r_offset());
1559             }
1560         }
1561       break;
1562
1563     case elfcpp::R_386_PC32:
1564     case elfcpp::R_386_PC16:
1565     case elfcpp::R_386_PC8:
1566       break;
1567
1568     case elfcpp::R_386_PLT32:
1569       // Since we know this is a local symbol, we can handle this as a
1570       // PC32 reloc.
1571       break;
1572
1573     case elfcpp::R_386_GOTOFF:
1574     case elfcpp::R_386_GOTPC:
1575       // We need a GOT section.
1576       target->got_section(symtab, layout);
1577       break;
1578
1579     case elfcpp::R_386_GOT32:
1580       {
1581         // The symbol requires a GOT entry.
1582         Output_data_got<32, false>* got = target->got_section(symtab, layout);
1583         unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1584
1585         // For a STT_GNU_IFUNC symbol we want the PLT offset.  That
1586         // lets function pointers compare correctly with shared
1587         // libraries.  Otherwise we would need an IRELATIVE reloc.
1588         bool is_new;
1589         if (lsym.get_st_type() == elfcpp::STT_GNU_IFUNC)
1590           is_new = got->add_local_plt(object, r_sym, GOT_TYPE_STANDARD);
1591         else
1592           is_new = got->add_local(object, r_sym, GOT_TYPE_STANDARD);
1593         if (is_new)
1594           {
1595             // If we are generating a shared object, we need to add a
1596             // dynamic RELATIVE relocation for this symbol's GOT entry.
1597             if (parameters->options().output_is_position_independent())
1598               {
1599                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1600                 unsigned int got_offset =
1601                   object->local_got_offset(r_sym, GOT_TYPE_STANDARD);
1602                 rel_dyn->add_local_relative(object, r_sym,
1603                                             elfcpp::R_386_RELATIVE,
1604                                             got, got_offset);
1605               }
1606           }
1607       }
1608       break;
1609
1610       // These are relocations which should only be seen by the
1611       // dynamic linker, and should never be seen here.
1612     case elfcpp::R_386_COPY:
1613     case elfcpp::R_386_GLOB_DAT:
1614     case elfcpp::R_386_JUMP_SLOT:
1615     case elfcpp::R_386_RELATIVE:
1616     case elfcpp::R_386_IRELATIVE:
1617     case elfcpp::R_386_TLS_TPOFF:
1618     case elfcpp::R_386_TLS_DTPMOD32:
1619     case elfcpp::R_386_TLS_DTPOFF32:
1620     case elfcpp::R_386_TLS_TPOFF32:
1621     case elfcpp::R_386_TLS_DESC:
1622       gold_error(_("%s: unexpected reloc %u in object file"),
1623                  object->name().c_str(), r_type);
1624       break;
1625
1626       // These are initial TLS relocs, which are expected when
1627       // linking.
1628     case elfcpp::R_386_TLS_GD:            // Global-dynamic
1629     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
1630     case elfcpp::R_386_TLS_DESC_CALL:
1631     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
1632     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
1633     case elfcpp::R_386_TLS_IE:            // Initial-exec
1634     case elfcpp::R_386_TLS_IE_32:
1635     case elfcpp::R_386_TLS_GOTIE:
1636     case elfcpp::R_386_TLS_LE:            // Local-exec
1637     case elfcpp::R_386_TLS_LE_32:
1638       {
1639         bool output_is_shared = parameters->options().shared();
1640         const tls::Tls_optimization optimized_type
1641             = Target_i386::optimize_tls_reloc(!output_is_shared, r_type);
1642         switch (r_type)
1643           {
1644           case elfcpp::R_386_TLS_GD:          // Global-dynamic
1645             if (optimized_type == tls::TLSOPT_NONE)
1646               {
1647                 // Create a pair of GOT entries for the module index and
1648                 // dtv-relative offset.
1649                 Output_data_got<32, false>* got
1650                     = target->got_section(symtab, layout);
1651                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1652                 unsigned int shndx = lsym.get_st_shndx();
1653                 bool is_ordinary;
1654                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1655                 if (!is_ordinary)
1656                   object->error(_("local symbol %u has bad shndx %u"),
1657                               r_sym, shndx);
1658                 else
1659                   got->add_local_pair_with_rel(object, r_sym, shndx,
1660                                                GOT_TYPE_TLS_PAIR,
1661                                                target->rel_dyn_section(layout),
1662                                                elfcpp::R_386_TLS_DTPMOD32, 0);
1663               }
1664             else if (optimized_type != tls::TLSOPT_TO_LE)
1665               unsupported_reloc_local(object, r_type);
1666             break;
1667
1668           case elfcpp::R_386_TLS_GOTDESC:     // Global-dynamic (from ~oliva)
1669             target->define_tls_base_symbol(symtab, layout);
1670             if (optimized_type == tls::TLSOPT_NONE)
1671               {
1672                 // Create a double GOT entry with an R_386_TLS_DESC
1673                 // reloc.  The R_386_TLS_DESC reloc is resolved
1674                 // lazily, so the GOT entry needs to be in an area in
1675                 // .got.plt, not .got.  Call got_section to make sure
1676                 // the section has been created.
1677                 target->got_section(symtab, layout);
1678                 Output_data_got<32, false>* got = target->got_tlsdesc_section();
1679                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1680                 if (!object->local_has_got_offset(r_sym, GOT_TYPE_TLS_DESC))
1681                   {
1682                     unsigned int got_offset = got->add_constant(0);
1683                     // The local symbol value is stored in the second
1684                     // GOT entry.
1685                     got->add_local(object, r_sym, GOT_TYPE_TLS_DESC);
1686                     // That set the GOT offset of the local symbol to
1687                     // point to the second entry, but we want it to
1688                     // point to the first.
1689                     object->set_local_got_offset(r_sym, GOT_TYPE_TLS_DESC,
1690                                                  got_offset);
1691                     Reloc_section* rt = target->rel_tls_desc_section(layout);
1692                     rt->add_absolute(elfcpp::R_386_TLS_DESC, got, got_offset);
1693                   }
1694               }
1695             else if (optimized_type != tls::TLSOPT_TO_LE)
1696               unsupported_reloc_local(object, r_type);
1697             break;
1698
1699           case elfcpp::R_386_TLS_DESC_CALL:
1700             break;
1701
1702           case elfcpp::R_386_TLS_LDM:         // Local-dynamic
1703             if (optimized_type == tls::TLSOPT_NONE)
1704               {
1705                 // Create a GOT entry for the module index.
1706                 target->got_mod_index_entry(symtab, layout, object);
1707               }
1708             else if (optimized_type != tls::TLSOPT_TO_LE)
1709               unsupported_reloc_local(object, r_type);
1710             break;
1711
1712           case elfcpp::R_386_TLS_LDO_32:      // Alternate local-dynamic
1713             break;
1714
1715           case elfcpp::R_386_TLS_IE:          // Initial-exec
1716           case elfcpp::R_386_TLS_IE_32:
1717           case elfcpp::R_386_TLS_GOTIE:
1718             layout->set_has_static_tls();
1719             if (optimized_type == tls::TLSOPT_NONE)
1720               {
1721                 // For the R_386_TLS_IE relocation, we need to create a
1722                 // dynamic relocation when building a shared library.
1723                 if (r_type == elfcpp::R_386_TLS_IE
1724                     && parameters->options().shared())
1725                   {
1726                     Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1727                     unsigned int r_sym
1728                         = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1729                     rel_dyn->add_local_relative(object, r_sym,
1730                                                 elfcpp::R_386_RELATIVE,
1731                                                 output_section, data_shndx,
1732                                                 reloc.get_r_offset());
1733                   }
1734                 // Create a GOT entry for the tp-relative offset.
1735                 Output_data_got<32, false>* got
1736                     = target->got_section(symtab, layout);
1737                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1738                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
1739                                            ? elfcpp::R_386_TLS_TPOFF32
1740                                            : elfcpp::R_386_TLS_TPOFF);
1741                 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
1742                                          ? GOT_TYPE_TLS_OFFSET
1743                                          : GOT_TYPE_TLS_NOFFSET);
1744                 got->add_local_with_rel(object, r_sym, got_type,
1745                                         target->rel_dyn_section(layout),
1746                                         dyn_r_type);
1747               }
1748             else if (optimized_type != tls::TLSOPT_TO_LE)
1749               unsupported_reloc_local(object, r_type);
1750             break;
1751
1752           case elfcpp::R_386_TLS_LE:          // Local-exec
1753           case elfcpp::R_386_TLS_LE_32:
1754             layout->set_has_static_tls();
1755             if (output_is_shared)
1756               {
1757                 // We need to create a dynamic relocation.
1758                 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
1759                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1760                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
1761                                            ? elfcpp::R_386_TLS_TPOFF32
1762                                            : elfcpp::R_386_TLS_TPOFF);
1763                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1764                 rel_dyn->add_local(object, r_sym, dyn_r_type, output_section,
1765                                    data_shndx, reloc.get_r_offset());
1766               }
1767             break;
1768
1769           default:
1770             gold_unreachable();
1771           }
1772       }
1773       break;
1774
1775     case elfcpp::R_386_32PLT:
1776     case elfcpp::R_386_TLS_GD_32:
1777     case elfcpp::R_386_TLS_GD_PUSH:
1778     case elfcpp::R_386_TLS_GD_CALL:
1779     case elfcpp::R_386_TLS_GD_POP:
1780     case elfcpp::R_386_TLS_LDM_32:
1781     case elfcpp::R_386_TLS_LDM_PUSH:
1782     case elfcpp::R_386_TLS_LDM_CALL:
1783     case elfcpp::R_386_TLS_LDM_POP:
1784     case elfcpp::R_386_USED_BY_INTEL_200:
1785     default:
1786       unsupported_reloc_local(object, r_type);
1787       break;
1788     }
1789 }
1790
1791 // Report an unsupported relocation against a global symbol.
1792
1793 void
1794 Target_i386::Scan::unsupported_reloc_global(
1795     Sized_relobj_file<32, false>* object,
1796     unsigned int r_type,
1797     Symbol* gsym)
1798 {
1799   gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1800              object->name().c_str(), r_type, gsym->demangled_name().c_str());
1801 }
1802
1803 inline bool
1804 Target_i386::Scan::possible_function_pointer_reloc(unsigned int r_type)
1805 {
1806   switch (r_type)
1807     {
1808     case elfcpp::R_386_32:
1809     case elfcpp::R_386_16:
1810     case elfcpp::R_386_8:
1811     case elfcpp::R_386_GOTOFF:
1812     case elfcpp::R_386_GOT32:
1813       {
1814         return true;
1815       }
1816     default:
1817       return false;
1818     }
1819   return false;
1820 }
1821
1822 inline bool
1823 Target_i386::Scan::local_reloc_may_be_function_pointer(
1824   Symbol_table* ,
1825   Layout* ,
1826   Target_i386* ,
1827   Sized_relobj_file<32, false>* ,
1828   unsigned int ,
1829   Output_section* ,
1830   const elfcpp::Rel<32, false>& ,
1831   unsigned int r_type,
1832   const elfcpp::Sym<32, false>&)
1833 {
1834   return possible_function_pointer_reloc(r_type);
1835 }
1836
1837 inline bool
1838 Target_i386::Scan::global_reloc_may_be_function_pointer(
1839   Symbol_table* ,
1840   Layout* ,
1841   Target_i386* ,
1842   Sized_relobj_file<32, false>* ,
1843   unsigned int ,
1844   Output_section* ,
1845   const elfcpp::Rel<32, false>& ,
1846   unsigned int r_type,
1847   Symbol*)
1848 {
1849   return possible_function_pointer_reloc(r_type);
1850 }
1851
1852 // Scan a relocation for a global symbol.
1853
1854 inline void
1855 Target_i386::Scan::global(Symbol_table* symtab,
1856                           Layout* layout,
1857                           Target_i386* target,
1858                           Sized_relobj_file<32, false>* object,
1859                           unsigned int data_shndx,
1860                           Output_section* output_section,
1861                           const elfcpp::Rel<32, false>& reloc,
1862                           unsigned int r_type,
1863                           Symbol* gsym)
1864 {
1865   // A STT_GNU_IFUNC symbol may require a PLT entry.
1866   if (gsym->type() == elfcpp::STT_GNU_IFUNC
1867       && this->reloc_needs_plt_for_ifunc(object, r_type))
1868     target->make_plt_entry(symtab, layout, gsym);
1869
1870   switch (r_type)
1871     {
1872     case elfcpp::R_386_NONE:
1873     case elfcpp::R_386_GNU_VTINHERIT:
1874     case elfcpp::R_386_GNU_VTENTRY:
1875       break;
1876
1877     case elfcpp::R_386_32:
1878     case elfcpp::R_386_16:
1879     case elfcpp::R_386_8:
1880       {
1881         // Make a PLT entry if necessary.
1882         if (gsym->needs_plt_entry())
1883           {
1884             target->make_plt_entry(symtab, layout, gsym);
1885             // Since this is not a PC-relative relocation, we may be
1886             // taking the address of a function. In that case we need to
1887             // set the entry in the dynamic symbol table to the address of
1888             // the PLT entry.
1889             if (gsym->is_from_dynobj() && !parameters->options().shared())
1890               gsym->set_needs_dynsym_value();
1891           }
1892         // Make a dynamic relocation if necessary.
1893         if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
1894           {
1895             if (gsym->may_need_copy_reloc())
1896               {
1897                 target->copy_reloc(symtab, layout, object,
1898                                    data_shndx, output_section, gsym, reloc);
1899               }
1900             else if (r_type == elfcpp::R_386_32
1901                      && gsym->type() == elfcpp::STT_GNU_IFUNC
1902                      && gsym->can_use_relative_reloc(false)
1903                      && !gsym->is_from_dynobj()
1904                      && !gsym->is_undefined()
1905                      && !gsym->is_preemptible())
1906               {
1907                 // Use an IRELATIVE reloc for a locally defined
1908                 // STT_GNU_IFUNC symbol.  This makes a function
1909                 // address in a PIE executable match the address in a
1910                 // shared library that it links against.
1911                 Reloc_section* rel_dyn = target->rel_irelative_section(layout);
1912                 rel_dyn->add_symbolless_global_addend(gsym,
1913                                                       elfcpp::R_386_IRELATIVE,
1914                                                       output_section,
1915                                                       object, data_shndx,
1916                                                       reloc.get_r_offset());
1917               }
1918             else if (r_type == elfcpp::R_386_32
1919                      && gsym->can_use_relative_reloc(false))
1920               {
1921                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1922                 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1923                                              output_section, object,
1924                                              data_shndx, reloc.get_r_offset());
1925               }
1926             else
1927               {
1928                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1929                 rel_dyn->add_global(gsym, r_type, output_section, object,
1930                                     data_shndx, reloc.get_r_offset());
1931               }
1932           }
1933       }
1934       break;
1935
1936     case elfcpp::R_386_PC32:
1937     case elfcpp::R_386_PC16:
1938     case elfcpp::R_386_PC8:
1939       {
1940         // Make a PLT entry if necessary.
1941         if (gsym->needs_plt_entry())
1942           {
1943             // These relocations are used for function calls only in
1944             // non-PIC code.  For a 32-bit relocation in a shared library,
1945             // we'll need a text relocation anyway, so we can skip the
1946             // PLT entry and let the dynamic linker bind the call directly
1947             // to the target.  For smaller relocations, we should use a
1948             // PLT entry to ensure that the call can reach.
1949             if (!parameters->options().shared()
1950                 || r_type != elfcpp::R_386_PC32)
1951               target->make_plt_entry(symtab, layout, gsym);
1952           }
1953         // Make a dynamic relocation if necessary.
1954         if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
1955           {
1956             if (gsym->may_need_copy_reloc())
1957               {
1958                 target->copy_reloc(symtab, layout, object,
1959                                    data_shndx, output_section, gsym, reloc);
1960               }
1961             else
1962               {
1963                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1964                 rel_dyn->add_global(gsym, r_type, output_section, object,
1965                                     data_shndx, reloc.get_r_offset());
1966               }
1967           }
1968       }
1969       break;
1970
1971     case elfcpp::R_386_GOT32:
1972       {
1973         // The symbol requires a GOT entry.
1974         Output_data_got<32, false>* got = target->got_section(symtab, layout);
1975         if (gsym->final_value_is_known())
1976           {
1977             // For a STT_GNU_IFUNC symbol we want the PLT address.
1978             if (gsym->type() == elfcpp::STT_GNU_IFUNC)
1979               got->add_global_plt(gsym, GOT_TYPE_STANDARD);
1980             else
1981               got->add_global(gsym, GOT_TYPE_STANDARD);
1982           }
1983         else
1984           {
1985             // If this symbol is not fully resolved, we need to add a
1986             // GOT entry with a dynamic relocation.
1987             Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1988             if (gsym->is_from_dynobj()
1989                 || gsym->is_undefined()
1990                 || gsym->is_preemptible()
1991                 || (gsym->type() == elfcpp::STT_GNU_IFUNC
1992                     && parameters->options().output_is_position_independent()))
1993               got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
1994                                        rel_dyn, elfcpp::R_386_GLOB_DAT);
1995             else
1996               {
1997                 // For a STT_GNU_IFUNC symbol we want to write the PLT
1998                 // offset into the GOT, so that function pointer
1999                 // comparisons work correctly.
2000                 bool is_new;
2001                 if (gsym->type() != elfcpp::STT_GNU_IFUNC)
2002                   is_new = got->add_global(gsym, GOT_TYPE_STANDARD);
2003                 else
2004                   {
2005                     is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD);
2006                     // Tell the dynamic linker to use the PLT address
2007                     // when resolving relocations.
2008                     if (gsym->is_from_dynobj()
2009                         && !parameters->options().shared())
2010                       gsym->set_needs_dynsym_value();
2011                   }
2012                 if (is_new)
2013                   {
2014                     unsigned int got_off = gsym->got_offset(GOT_TYPE_STANDARD);
2015                     rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
2016                                                  got, got_off);
2017                   }
2018               }
2019           }
2020       }
2021       break;
2022
2023     case elfcpp::R_386_PLT32:
2024       // If the symbol is fully resolved, this is just a PC32 reloc.
2025       // Otherwise we need a PLT entry.
2026       if (gsym->final_value_is_known())
2027         break;
2028       // If building a shared library, we can also skip the PLT entry
2029       // if the symbol is defined in the output file and is protected
2030       // or hidden.
2031       if (gsym->is_defined()
2032           && !gsym->is_from_dynobj()
2033           && !gsym->is_preemptible())
2034         break;
2035       target->make_plt_entry(symtab, layout, gsym);
2036       break;
2037
2038     case elfcpp::R_386_GOTOFF:
2039     case elfcpp::R_386_GOTPC:
2040       // We need a GOT section.
2041       target->got_section(symtab, layout);
2042       break;
2043
2044       // These are relocations which should only be seen by the
2045       // dynamic linker, and should never be seen here.
2046     case elfcpp::R_386_COPY:
2047     case elfcpp::R_386_GLOB_DAT:
2048     case elfcpp::R_386_JUMP_SLOT:
2049     case elfcpp::R_386_RELATIVE:
2050     case elfcpp::R_386_IRELATIVE:
2051     case elfcpp::R_386_TLS_TPOFF:
2052     case elfcpp::R_386_TLS_DTPMOD32:
2053     case elfcpp::R_386_TLS_DTPOFF32:
2054     case elfcpp::R_386_TLS_TPOFF32:
2055     case elfcpp::R_386_TLS_DESC:
2056       gold_error(_("%s: unexpected reloc %u in object file"),
2057                  object->name().c_str(), r_type);
2058       break;
2059
2060       // These are initial tls relocs, which are expected when
2061       // linking.
2062     case elfcpp::R_386_TLS_GD:            // Global-dynamic
2063     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
2064     case elfcpp::R_386_TLS_DESC_CALL:
2065     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
2066     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
2067     case elfcpp::R_386_TLS_IE:            // Initial-exec
2068     case elfcpp::R_386_TLS_IE_32:
2069     case elfcpp::R_386_TLS_GOTIE:
2070     case elfcpp::R_386_TLS_LE:            // Local-exec
2071     case elfcpp::R_386_TLS_LE_32:
2072       {
2073         const bool is_final = gsym->final_value_is_known();
2074         const tls::Tls_optimization optimized_type
2075             = Target_i386::optimize_tls_reloc(is_final, r_type);
2076         switch (r_type)
2077           {
2078           case elfcpp::R_386_TLS_GD:          // Global-dynamic
2079             if (optimized_type == tls::TLSOPT_NONE)
2080               {
2081                 // Create a pair of GOT entries for the module index and
2082                 // dtv-relative offset.
2083                 Output_data_got<32, false>* got
2084                     = target->got_section(symtab, layout);
2085                 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
2086                                              target->rel_dyn_section(layout),
2087                                              elfcpp::R_386_TLS_DTPMOD32,
2088                                              elfcpp::R_386_TLS_DTPOFF32);
2089               }
2090             else if (optimized_type == tls::TLSOPT_TO_IE)
2091               {
2092                 // Create a GOT entry for the tp-relative offset.
2093                 Output_data_got<32, false>* got
2094                     = target->got_section(symtab, layout);
2095                 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
2096                                          target->rel_dyn_section(layout),
2097                                          elfcpp::R_386_TLS_TPOFF);
2098               }
2099             else if (optimized_type != tls::TLSOPT_TO_LE)
2100               unsupported_reloc_global(object, r_type, gsym);
2101             break;
2102
2103           case elfcpp::R_386_TLS_GOTDESC:     // Global-dynamic (~oliva url)
2104             target->define_tls_base_symbol(symtab, layout);
2105             if (optimized_type == tls::TLSOPT_NONE)
2106               {
2107                 // Create a double GOT entry with an R_386_TLS_DESC
2108                 // reloc.  The R_386_TLS_DESC reloc is resolved
2109                 // lazily, so the GOT entry needs to be in an area in
2110                 // .got.plt, not .got.  Call got_section to make sure
2111                 // the section has been created.
2112                 target->got_section(symtab, layout);
2113                 Output_data_got<32, false>* got = target->got_tlsdesc_section();
2114                 Reloc_section* rt = target->rel_tls_desc_section(layout);
2115                 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC, rt,
2116                                              elfcpp::R_386_TLS_DESC, 0);
2117               }
2118             else if (optimized_type == tls::TLSOPT_TO_IE)
2119               {
2120                 // Create a GOT entry for the tp-relative offset.
2121                 Output_data_got<32, false>* got
2122                     = target->got_section(symtab, layout);
2123                 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
2124                                          target->rel_dyn_section(layout),
2125                                          elfcpp::R_386_TLS_TPOFF);
2126               }
2127             else if (optimized_type != tls::TLSOPT_TO_LE)
2128               unsupported_reloc_global(object, r_type, gsym);
2129             break;
2130
2131           case elfcpp::R_386_TLS_DESC_CALL:
2132             break;
2133
2134           case elfcpp::R_386_TLS_LDM:         // Local-dynamic
2135             if (optimized_type == tls::TLSOPT_NONE)
2136               {
2137                 // Create a GOT entry for the module index.
2138                 target->got_mod_index_entry(symtab, layout, object);
2139               }
2140             else if (optimized_type != tls::TLSOPT_TO_LE)
2141               unsupported_reloc_global(object, r_type, gsym);
2142             break;
2143
2144           case elfcpp::R_386_TLS_LDO_32:      // Alternate local-dynamic
2145             break;
2146
2147           case elfcpp::R_386_TLS_IE:          // Initial-exec
2148           case elfcpp::R_386_TLS_IE_32:
2149           case elfcpp::R_386_TLS_GOTIE:
2150             layout->set_has_static_tls();
2151             if (optimized_type == tls::TLSOPT_NONE)
2152               {
2153                 // For the R_386_TLS_IE relocation, we need to create a
2154                 // dynamic relocation when building a shared library.
2155                 if (r_type == elfcpp::R_386_TLS_IE
2156                     && parameters->options().shared())
2157                   {
2158                     Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2159                     rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
2160                                                  output_section, object,
2161                                                  data_shndx,
2162                                                  reloc.get_r_offset());
2163                   }
2164                 // Create a GOT entry for the tp-relative offset.
2165                 Output_data_got<32, false>* got
2166                     = target->got_section(symtab, layout);
2167                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
2168                                            ? elfcpp::R_386_TLS_TPOFF32
2169                                            : elfcpp::R_386_TLS_TPOFF);
2170                 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
2171                                          ? GOT_TYPE_TLS_OFFSET
2172                                          : GOT_TYPE_TLS_NOFFSET);
2173                 got->add_global_with_rel(gsym, got_type,
2174                                          target->rel_dyn_section(layout),
2175                                          dyn_r_type);
2176               }
2177             else if (optimized_type != tls::TLSOPT_TO_LE)
2178               unsupported_reloc_global(object, r_type, gsym);
2179             break;
2180
2181           case elfcpp::R_386_TLS_LE:          // Local-exec
2182           case elfcpp::R_386_TLS_LE_32:
2183             layout->set_has_static_tls();
2184             if (parameters->options().shared())
2185               {
2186                 // We need to create a dynamic relocation.
2187                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
2188                                            ? elfcpp::R_386_TLS_TPOFF32
2189                                            : elfcpp::R_386_TLS_TPOFF);
2190                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2191                 rel_dyn->add_global(gsym, dyn_r_type, output_section, object,
2192                                     data_shndx, reloc.get_r_offset());
2193               }
2194             break;
2195
2196           default:
2197             gold_unreachable();
2198           }
2199       }
2200       break;
2201
2202     case elfcpp::R_386_32PLT:
2203     case elfcpp::R_386_TLS_GD_32:
2204     case elfcpp::R_386_TLS_GD_PUSH:
2205     case elfcpp::R_386_TLS_GD_CALL:
2206     case elfcpp::R_386_TLS_GD_POP:
2207     case elfcpp::R_386_TLS_LDM_32:
2208     case elfcpp::R_386_TLS_LDM_PUSH:
2209     case elfcpp::R_386_TLS_LDM_CALL:
2210     case elfcpp::R_386_TLS_LDM_POP:
2211     case elfcpp::R_386_USED_BY_INTEL_200:
2212     default:
2213       unsupported_reloc_global(object, r_type, gsym);
2214       break;
2215     }
2216 }
2217
2218 // Process relocations for gc.
2219
2220 void
2221 Target_i386::gc_process_relocs(Symbol_table* symtab,
2222                                Layout* layout,
2223                                Sized_relobj_file<32, false>* object,
2224                                unsigned int data_shndx,
2225                                unsigned int,
2226                                const unsigned char* prelocs,
2227                                size_t reloc_count,
2228                                Output_section* output_section,
2229                                bool needs_special_offset_handling,
2230                                size_t local_symbol_count,
2231                                const unsigned char* plocal_symbols)
2232 {
2233   gold::gc_process_relocs<32, false, Target_i386, elfcpp::SHT_REL,
2234                           Target_i386::Scan,
2235                           Target_i386::Relocatable_size_for_reloc>(
2236     symtab,
2237     layout,
2238     this,
2239     object,
2240     data_shndx,
2241     prelocs,
2242     reloc_count,
2243     output_section,
2244     needs_special_offset_handling,
2245     local_symbol_count,
2246     plocal_symbols);
2247 }
2248
2249 // Scan relocations for a section.
2250
2251 void
2252 Target_i386::scan_relocs(Symbol_table* symtab,
2253                          Layout* layout,
2254                          Sized_relobj_file<32, false>* object,
2255                          unsigned int data_shndx,
2256                          unsigned int sh_type,
2257                          const unsigned char* prelocs,
2258                          size_t reloc_count,
2259                          Output_section* output_section,
2260                          bool needs_special_offset_handling,
2261                          size_t local_symbol_count,
2262                          const unsigned char* plocal_symbols)
2263 {
2264   if (sh_type == elfcpp::SHT_RELA)
2265     {
2266       gold_error(_("%s: unsupported RELA reloc section"),
2267                  object->name().c_str());
2268       return;
2269     }
2270
2271   gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL,
2272                     Target_i386::Scan>(
2273     symtab,
2274     layout,
2275     this,
2276     object,
2277     data_shndx,
2278     prelocs,
2279     reloc_count,
2280     output_section,
2281     needs_special_offset_handling,
2282     local_symbol_count,
2283     plocal_symbols);
2284 }
2285
2286 // Finalize the sections.
2287
2288 void
2289 Target_i386::do_finalize_sections(
2290     Layout* layout,
2291     const Input_objects*,
2292     Symbol_table* symtab)
2293 {
2294   const Reloc_section* rel_plt = (this->plt_ == NULL
2295                                   ? NULL
2296                                   : this->plt_->rel_plt());
2297   layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
2298                                   this->rel_dyn_, true, false);
2299
2300   // Emit any relocs we saved in an attempt to avoid generating COPY
2301   // relocs.
2302   if (this->copy_relocs_.any_saved_relocs())
2303     this->copy_relocs_.emit(this->rel_dyn_section(layout));
2304
2305   // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
2306   // the .got.plt section.
2307   Symbol* sym = this->global_offset_table_;
2308   if (sym != NULL)
2309     {
2310       uint32_t data_size = this->got_plt_->current_data_size();
2311       symtab->get_sized_symbol<32>(sym)->set_symsize(data_size);
2312     }
2313
2314   if (parameters->doing_static_link()
2315       && (this->plt_ == NULL || !this->plt_->has_irelative_section()))
2316     {
2317       // If linking statically, make sure that the __rel_iplt symbols
2318       // were defined if necessary, even if we didn't create a PLT.
2319       static const Define_symbol_in_segment syms[] =
2320         {
2321           {
2322             "__rel_iplt_start",         // name
2323             elfcpp::PT_LOAD,            // segment_type
2324             elfcpp::PF_W,               // segment_flags_set
2325             elfcpp::PF(0),              // segment_flags_clear
2326             0,                          // value
2327             0,                          // size
2328             elfcpp::STT_NOTYPE,         // type
2329             elfcpp::STB_GLOBAL,         // binding
2330             elfcpp::STV_HIDDEN,         // visibility
2331             0,                          // nonvis
2332             Symbol::SEGMENT_START,      // offset_from_base
2333             true                        // only_if_ref
2334           },
2335           {
2336             "__rel_iplt_end",           // name
2337             elfcpp::PT_LOAD,            // segment_type
2338             elfcpp::PF_W,               // segment_flags_set
2339             elfcpp::PF(0),              // segment_flags_clear
2340             0,                          // value
2341             0,                          // size
2342             elfcpp::STT_NOTYPE,         // type
2343             elfcpp::STB_GLOBAL,         // binding
2344             elfcpp::STV_HIDDEN,         // visibility
2345             0,                          // nonvis
2346             Symbol::SEGMENT_START,      // offset_from_base
2347             true                        // only_if_ref
2348           }
2349         };
2350
2351       symtab->define_symbols(layout, 2, syms,
2352                              layout->script_options()->saw_sections_clause());
2353     }
2354 }
2355
2356 // Return whether a direct absolute static relocation needs to be applied.
2357 // In cases where Scan::local() or Scan::global() has created
2358 // a dynamic relocation other than R_386_RELATIVE, the addend
2359 // of the relocation is carried in the data, and we must not
2360 // apply the static relocation.
2361
2362 inline bool
2363 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol<32>* gsym,
2364                                                  unsigned int r_type,
2365                                                  bool is_32bit,
2366                                                  Output_section* output_section)
2367 {
2368   // If the output section is not allocated, then we didn't call
2369   // scan_relocs, we didn't create a dynamic reloc, and we must apply
2370   // the reloc here.
2371   if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
2372     return true;
2373
2374   int ref_flags = Scan::get_reference_flags(r_type);
2375
2376   // For local symbols, we will have created a non-RELATIVE dynamic
2377   // relocation only if (a) the output is position independent,
2378   // (b) the relocation is absolute (not pc- or segment-relative), and
2379   // (c) the relocation is not 32 bits wide.
2380   if (gsym == NULL)
2381     return !(parameters->options().output_is_position_independent()
2382              && (ref_flags & Symbol::ABSOLUTE_REF)
2383              && !is_32bit);
2384
2385   // For global symbols, we use the same helper routines used in the
2386   // scan pass.  If we did not create a dynamic relocation, or if we
2387   // created a RELATIVE dynamic relocation, we should apply the static
2388   // relocation.
2389   bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
2390   bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
2391                 && gsym->can_use_relative_reloc(ref_flags
2392                                                 & Symbol::FUNCTION_CALL);
2393   return !has_dyn || is_rel;
2394 }
2395
2396 // Perform a relocation.
2397
2398 inline bool
2399 Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
2400                                 Target_i386* target,
2401                                 Output_section* output_section,
2402                                 size_t relnum,
2403                                 const elfcpp::Rel<32, false>& rel,
2404                                 unsigned int r_type,
2405                                 const Sized_symbol<32>* gsym,
2406                                 const Symbol_value<32>* psymval,
2407                                 unsigned char* view,
2408                                 elfcpp::Elf_types<32>::Elf_Addr address,
2409                                 section_size_type view_size)
2410 {
2411   if (this->skip_call_tls_get_addr_)
2412     {
2413       if ((r_type != elfcpp::R_386_PLT32
2414            && r_type != elfcpp::R_386_PC32)
2415           || gsym == NULL
2416           || strcmp(gsym->name(), "___tls_get_addr") != 0)
2417         gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2418                                _("missing expected TLS relocation"));
2419       else
2420         {
2421           this->skip_call_tls_get_addr_ = false;
2422           return false;
2423         }
2424     }
2425
2426   const Sized_relobj_file<32, false>* object = relinfo->object;
2427
2428   // Pick the value to use for symbols defined in shared objects.
2429   Symbol_value<32> symval;
2430   if (gsym != NULL
2431       && gsym->type() == elfcpp::STT_GNU_IFUNC
2432       && r_type == elfcpp::R_386_32
2433       && gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type))
2434       && gsym->can_use_relative_reloc(false)
2435       && !gsym->is_from_dynobj()
2436       && !gsym->is_undefined()
2437       && !gsym->is_preemptible())
2438     {
2439       // In this case we are generating a R_386_IRELATIVE reloc.  We
2440       // want to use the real value of the symbol, not the PLT offset.
2441     }
2442   else if (gsym != NULL
2443            && gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
2444     {
2445       symval.set_output_value(target->plt_address_for_global(gsym)
2446                               + gsym->plt_offset());
2447       psymval = &symval;
2448     }
2449   else if (gsym == NULL && psymval->is_ifunc_symbol())
2450     {
2451       unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2452       if (object->local_has_plt_offset(r_sym))
2453         {
2454           symval.set_output_value(target->plt_address_for_local(object, r_sym)
2455                                   + object->local_plt_offset(r_sym));
2456           psymval = &symval;
2457         }
2458     }
2459
2460   // Get the GOT offset if needed.
2461   // The GOT pointer points to the end of the GOT section.
2462   // We need to subtract the size of the GOT section to get
2463   // the actual offset to use in the relocation.
2464   bool have_got_offset = false;
2465   unsigned int got_offset = 0;
2466   switch (r_type)
2467     {
2468     case elfcpp::R_386_GOT32:
2469       if (gsym != NULL)
2470         {
2471           gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
2472           got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
2473                         - target->got_size());
2474         }
2475       else
2476         {
2477           unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2478           gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
2479           got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
2480                         - target->got_size());
2481         }
2482       have_got_offset = true;
2483       break;
2484
2485     default:
2486       break;
2487     }
2488
2489   switch (r_type)
2490     {
2491     case elfcpp::R_386_NONE:
2492     case elfcpp::R_386_GNU_VTINHERIT:
2493     case elfcpp::R_386_GNU_VTENTRY:
2494       break;
2495
2496     case elfcpp::R_386_32:
2497       if (should_apply_static_reloc(gsym, r_type, true, output_section))
2498         Relocate_functions<32, false>::rel32(view, object, psymval);
2499       break;
2500
2501     case elfcpp::R_386_PC32:
2502       if (should_apply_static_reloc(gsym, r_type, true, output_section))
2503         Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
2504       break;
2505
2506     case elfcpp::R_386_16:
2507       if (should_apply_static_reloc(gsym, r_type, false, output_section))
2508         Relocate_functions<32, false>::rel16(view, object, psymval);
2509       break;
2510
2511     case elfcpp::R_386_PC16:
2512       if (should_apply_static_reloc(gsym, r_type, false, output_section))
2513         Relocate_functions<32, false>::pcrel16(view, object, psymval, address);
2514       break;
2515
2516     case elfcpp::R_386_8:
2517       if (should_apply_static_reloc(gsym, r_type, false, output_section))
2518         Relocate_functions<32, false>::rel8(view, object, psymval);
2519       break;
2520
2521     case elfcpp::R_386_PC8:
2522       if (should_apply_static_reloc(gsym, r_type, false, output_section))
2523         Relocate_functions<32, false>::pcrel8(view, object, psymval, address);
2524       break;
2525
2526     case elfcpp::R_386_PLT32:
2527       gold_assert(gsym == NULL
2528                   || gsym->has_plt_offset()
2529                   || gsym->final_value_is_known()
2530                   || (gsym->is_defined()
2531                       && !gsym->is_from_dynobj()
2532                       && !gsym->is_preemptible()));
2533       Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
2534       break;
2535
2536     case elfcpp::R_386_GOT32:
2537       gold_assert(have_got_offset);
2538       Relocate_functions<32, false>::rel32(view, got_offset);
2539       break;
2540
2541     case elfcpp::R_386_GOTOFF:
2542       {
2543         elfcpp::Elf_types<32>::Elf_Addr value;
2544         value = (psymval->value(object, 0)
2545                  - target->got_plt_section()->address());
2546         Relocate_functions<32, false>::rel32(view, value);
2547       }
2548       break;
2549
2550     case elfcpp::R_386_GOTPC:
2551       {
2552         elfcpp::Elf_types<32>::Elf_Addr value;
2553         value = target->got_plt_section()->address();
2554         Relocate_functions<32, false>::pcrel32(view, value, address);
2555       }
2556       break;
2557
2558     case elfcpp::R_386_COPY:
2559     case elfcpp::R_386_GLOB_DAT:
2560     case elfcpp::R_386_JUMP_SLOT:
2561     case elfcpp::R_386_RELATIVE:
2562     case elfcpp::R_386_IRELATIVE:
2563       // These are outstanding tls relocs, which are unexpected when
2564       // linking.
2565     case elfcpp::R_386_TLS_TPOFF:
2566     case elfcpp::R_386_TLS_DTPMOD32:
2567     case elfcpp::R_386_TLS_DTPOFF32:
2568     case elfcpp::R_386_TLS_TPOFF32:
2569     case elfcpp::R_386_TLS_DESC:
2570       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2571                              _("unexpected reloc %u in object file"),
2572                              r_type);
2573       break;
2574
2575       // These are initial tls relocs, which are expected when
2576       // linking.
2577     case elfcpp::R_386_TLS_GD:             // Global-dynamic
2578     case elfcpp::R_386_TLS_GOTDESC:        // Global-dynamic (from ~oliva url)
2579     case elfcpp::R_386_TLS_DESC_CALL:
2580     case elfcpp::R_386_TLS_LDM:            // Local-dynamic
2581     case elfcpp::R_386_TLS_LDO_32:         // Alternate local-dynamic
2582     case elfcpp::R_386_TLS_IE:             // Initial-exec
2583     case elfcpp::R_386_TLS_IE_32:
2584     case elfcpp::R_386_TLS_GOTIE:
2585     case elfcpp::R_386_TLS_LE:             // Local-exec
2586     case elfcpp::R_386_TLS_LE_32:
2587       this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
2588                          view, address, view_size);
2589       break;
2590
2591     case elfcpp::R_386_32PLT:
2592     case elfcpp::R_386_TLS_GD_32:
2593     case elfcpp::R_386_TLS_GD_PUSH:
2594     case elfcpp::R_386_TLS_GD_CALL:
2595     case elfcpp::R_386_TLS_GD_POP:
2596     case elfcpp::R_386_TLS_LDM_32:
2597     case elfcpp::R_386_TLS_LDM_PUSH:
2598     case elfcpp::R_386_TLS_LDM_CALL:
2599     case elfcpp::R_386_TLS_LDM_POP:
2600     case elfcpp::R_386_USED_BY_INTEL_200:
2601     default:
2602       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2603                              _("unsupported reloc %u"),
2604                              r_type);
2605       break;
2606     }
2607
2608   return true;
2609 }
2610
2611 // Perform a TLS relocation.
2612
2613 inline void
2614 Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo,
2615                                     Target_i386* target,
2616                                     size_t relnum,
2617                                     const elfcpp::Rel<32, false>& rel,
2618                                     unsigned int r_type,
2619                                     const Sized_symbol<32>* gsym,
2620                                     const Symbol_value<32>* psymval,
2621                                     unsigned char* view,
2622                                     elfcpp::Elf_types<32>::Elf_Addr,
2623                                     section_size_type view_size)
2624 {
2625   Output_segment* tls_segment = relinfo->layout->tls_segment();
2626
2627   const Sized_relobj_file<32, false>* object = relinfo->object;
2628
2629   elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
2630
2631   const bool is_final = (gsym == NULL
2632                          ? !parameters->options().shared()
2633                          : gsym->final_value_is_known());
2634   const tls::Tls_optimization optimized_type
2635       = Target_i386::optimize_tls_reloc(is_final, r_type);
2636   switch (r_type)
2637     {
2638     case elfcpp::R_386_TLS_GD:           // Global-dynamic
2639       if (optimized_type == tls::TLSOPT_TO_LE)
2640         {
2641           if (tls_segment == NULL)
2642             {
2643               gold_assert(parameters->errors()->error_count() > 0);
2644               return;
2645             }
2646           this->tls_gd_to_le(relinfo, relnum, tls_segment,
2647                              rel, r_type, value, view,
2648                              view_size);
2649           break;
2650         }
2651       else
2652         {
2653           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
2654                                    ? GOT_TYPE_TLS_NOFFSET
2655                                    : GOT_TYPE_TLS_PAIR);
2656           unsigned int got_offset;
2657           if (gsym != NULL)
2658             {
2659               gold_assert(gsym->has_got_offset(got_type));
2660               got_offset = gsym->got_offset(got_type) - target->got_size();
2661             }
2662           else
2663             {
2664               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2665               gold_assert(object->local_has_got_offset(r_sym, got_type));
2666               got_offset = (object->local_got_offset(r_sym, got_type)
2667                             - target->got_size());
2668             }
2669           if (optimized_type == tls::TLSOPT_TO_IE)
2670             {
2671               if (tls_segment == NULL)
2672                 {
2673                   gold_assert(parameters->errors()->error_count() > 0);
2674                   return;
2675                 }
2676               this->tls_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
2677                                  got_offset, view, view_size);
2678               break;
2679             }
2680           else if (optimized_type == tls::TLSOPT_NONE)
2681             {
2682               // Relocate the field with the offset of the pair of GOT
2683               // entries.
2684               Relocate_functions<32, false>::rel32(view, got_offset);
2685               break;
2686             }
2687         }
2688       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2689                              _("unsupported reloc %u"),
2690                              r_type);
2691       break;
2692
2693     case elfcpp::R_386_TLS_GOTDESC:      // Global-dynamic (from ~oliva url)
2694     case elfcpp::R_386_TLS_DESC_CALL:
2695       this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
2696       if (optimized_type == tls::TLSOPT_TO_LE)
2697         {
2698           if (tls_segment == NULL)
2699             {
2700               gold_assert(parameters->errors()->error_count() > 0);
2701               return;
2702             }
2703           this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
2704                                   rel, r_type, value, view,
2705                                   view_size);
2706           break;
2707         }
2708       else
2709         {
2710           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
2711                                    ? GOT_TYPE_TLS_NOFFSET
2712                                    : GOT_TYPE_TLS_DESC);
2713           unsigned int got_offset = 0;
2714           if (r_type == elfcpp::R_386_TLS_GOTDESC
2715               && optimized_type == tls::TLSOPT_NONE)
2716             {
2717               // We created GOT entries in the .got.tlsdesc portion of
2718               // the .got.plt section, but the offset stored in the
2719               // symbol is the offset within .got.tlsdesc.
2720               got_offset = (target->got_size()
2721                             + target->got_plt_section()->data_size());
2722             }
2723           if (gsym != NULL)
2724             {
2725               gold_assert(gsym->has_got_offset(got_type));
2726               got_offset += gsym->got_offset(got_type) - target->got_size();
2727             }
2728           else
2729             {
2730               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2731               gold_assert(object->local_has_got_offset(r_sym, got_type));
2732               got_offset += (object->local_got_offset(r_sym, got_type)
2733                              - target->got_size());
2734             }
2735           if (optimized_type == tls::TLSOPT_TO_IE)
2736             {
2737               if (tls_segment == NULL)
2738                 {
2739                   gold_assert(parameters->errors()->error_count() > 0);
2740                   return;
2741                 }
2742               this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
2743                                       got_offset, view, view_size);
2744               break;
2745             }
2746           else if (optimized_type == tls::TLSOPT_NONE)
2747             {
2748               if (r_type == elfcpp::R_386_TLS_GOTDESC)
2749                 {
2750                   // Relocate the field with the offset of the pair of GOT
2751                   // entries.
2752                   Relocate_functions<32, false>::rel32(view, got_offset);
2753                 }
2754               break;
2755             }
2756         }
2757       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2758                              _("unsupported reloc %u"),
2759                              r_type);
2760       break;
2761
2762     case elfcpp::R_386_TLS_LDM:          // Local-dynamic
2763       if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN)
2764         {
2765           gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2766                                  _("both SUN and GNU model "
2767                                    "TLS relocations"));
2768           break;
2769         }
2770       this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
2771       if (optimized_type == tls::TLSOPT_TO_LE)
2772         {
2773           if (tls_segment == NULL)
2774             {
2775               gold_assert(parameters->errors()->error_count() > 0);
2776               return;
2777             }
2778           this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, r_type,
2779                              value, view, view_size);
2780           break;
2781         }
2782       else if (optimized_type == tls::TLSOPT_NONE)
2783         {
2784           // Relocate the field with the offset of the GOT entry for
2785           // the module index.
2786           unsigned int got_offset;
2787           got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
2788                         - target->got_size());
2789           Relocate_functions<32, false>::rel32(view, got_offset);
2790           break;
2791         }
2792       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2793                              _("unsupported reloc %u"),
2794                              r_type);
2795       break;
2796
2797     case elfcpp::R_386_TLS_LDO_32:       // Alternate local-dynamic
2798       if (optimized_type == tls::TLSOPT_TO_LE)
2799         {
2800           // This reloc can appear in debugging sections, in which
2801           // case we must not convert to local-exec.  We decide what
2802           // to do based on whether the section is marked as
2803           // containing executable code.  That is what the GNU linker
2804           // does as well.
2805           elfcpp::Shdr<32, false> shdr(relinfo->data_shdr);
2806           if ((shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0)
2807             {
2808               if (tls_segment == NULL)
2809                 {
2810                   gold_assert(parameters->errors()->error_count() > 0);
2811                   return;
2812                 }
2813               value -= tls_segment->memsz();
2814             }
2815         }
2816       Relocate_functions<32, false>::rel32(view, value);
2817       break;
2818
2819     case elfcpp::R_386_TLS_IE:           // Initial-exec
2820     case elfcpp::R_386_TLS_GOTIE:
2821     case elfcpp::R_386_TLS_IE_32:
2822       if (optimized_type == tls::TLSOPT_TO_LE)
2823         {
2824           if (tls_segment == NULL)
2825             {
2826               gold_assert(parameters->errors()->error_count() > 0);
2827               return;
2828             }
2829           Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
2830                                               rel, r_type, value, view,
2831                                               view_size);
2832           break;
2833         }
2834       else if (optimized_type == tls::TLSOPT_NONE)
2835         {
2836           // Relocate the field with the offset of the GOT entry for
2837           // the tp-relative offset of the symbol.
2838           unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
2839                                    ? GOT_TYPE_TLS_OFFSET
2840                                    : GOT_TYPE_TLS_NOFFSET);
2841           unsigned int got_offset;
2842           if (gsym != NULL)
2843             {
2844               gold_assert(gsym->has_got_offset(got_type));
2845               got_offset = gsym->got_offset(got_type);
2846             }
2847           else
2848             {
2849               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2850               gold_assert(object->local_has_got_offset(r_sym, got_type));
2851               got_offset = object->local_got_offset(r_sym, got_type);
2852             }
2853           // For the R_386_TLS_IE relocation, we need to apply the
2854           // absolute address of the GOT entry.
2855           if (r_type == elfcpp::R_386_TLS_IE)
2856             got_offset += target->got_plt_section()->address();
2857           // All GOT offsets are relative to the end of the GOT.
2858           got_offset -= target->got_size();
2859           Relocate_functions<32, false>::rel32(view, got_offset);
2860           break;
2861         }
2862       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2863                              _("unsupported reloc %u"),
2864                              r_type);
2865       break;
2866
2867     case elfcpp::R_386_TLS_LE:           // Local-exec
2868       // If we're creating a shared library, a dynamic relocation will
2869       // have been created for this location, so do not apply it now.
2870       if (!parameters->options().shared())
2871         {
2872           if (tls_segment == NULL)
2873             {
2874               gold_assert(parameters->errors()->error_count() > 0);
2875               return;
2876             }
2877           value -= tls_segment->memsz();
2878           Relocate_functions<32, false>::rel32(view, value);
2879         }
2880       break;
2881
2882     case elfcpp::R_386_TLS_LE_32:
2883       // If we're creating a shared library, a dynamic relocation will
2884       // have been created for this location, so do not apply it now.
2885       if (!parameters->options().shared())
2886         {
2887           if (tls_segment == NULL)
2888             {
2889               gold_assert(parameters->errors()->error_count() > 0);
2890               return;
2891             }
2892           value = tls_segment->memsz() - value;
2893           Relocate_functions<32, false>::rel32(view, value);
2894         }
2895       break;
2896     }
2897 }
2898
2899 // Do a relocation in which we convert a TLS General-Dynamic to a
2900 // Local-Exec.
2901
2902 inline void
2903 Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo,
2904                                     size_t relnum,
2905                                     Output_segment* tls_segment,
2906                                     const elfcpp::Rel<32, false>& rel,
2907                                     unsigned int,
2908                                     elfcpp::Elf_types<32>::Elf_Addr value,
2909                                     unsigned char* view,
2910                                     section_size_type view_size)
2911 {
2912   // leal foo(,%reg,1),%eax; call ___tls_get_addr
2913   //  ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2914   // leal foo(%reg),%eax; call ___tls_get_addr
2915   //  ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2916
2917   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2918   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2919
2920   unsigned char op1 = view[-1];
2921   unsigned char op2 = view[-2];
2922
2923   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2924                  op2 == 0x8d || op2 == 0x04);
2925   tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2926
2927   int roff = 5;
2928
2929   if (op2 == 0x04)
2930     {
2931       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
2932       tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
2933       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2934                      ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
2935       memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2936     }
2937   else
2938     {
2939       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2940                      (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
2941       if (rel.get_r_offset() + 9 < view_size
2942           && view[9] == 0x90)
2943         {
2944           // There is a trailing nop.  Use the size byte subl.
2945           memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2946           roff = 6;
2947         }
2948       else
2949         {
2950           // Use the five byte subl.
2951           memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2952         }
2953     }
2954
2955   value = tls_segment->memsz() - value;
2956   Relocate_functions<32, false>::rel32(view + roff, value);
2957
2958   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2959   // We can skip it.
2960   this->skip_call_tls_get_addr_ = true;
2961 }
2962
2963 // Do a relocation in which we convert a TLS General-Dynamic to an
2964 // Initial-Exec.
2965
2966 inline void
2967 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info<32, false>* relinfo,
2968                                     size_t relnum,
2969                                     Output_segment*,
2970                                     const elfcpp::Rel<32, false>& rel,
2971                                     unsigned int,
2972                                     elfcpp::Elf_types<32>::Elf_Addr value,
2973                                     unsigned char* view,
2974                                     section_size_type view_size)
2975 {
2976   // leal foo(,%ebx,1),%eax; call ___tls_get_addr
2977   //  ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
2978
2979   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2980   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2981
2982   unsigned char op1 = view[-1];
2983   unsigned char op2 = view[-2];
2984
2985   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2986                  op2 == 0x8d || op2 == 0x04);
2987   tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2988
2989   int roff = 5;
2990
2991   // FIXME: For now, support only the first (SIB) form.
2992   tls::check_tls(relinfo, relnum, rel.get_r_offset(), op2 == 0x04);
2993
2994   if (op2 == 0x04)
2995     {
2996       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
2997       tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
2998       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2999                      ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
3000       memcpy(view - 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
3001     }
3002   else
3003     {
3004       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3005                      (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
3006       if (rel.get_r_offset() + 9 < view_size
3007           && view[9] == 0x90)
3008         {
3009           // FIXME: This is not the right instruction sequence.
3010           // There is a trailing nop.  Use the size byte subl.
3011           memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3012           roff = 6;
3013         }
3014       else
3015         {
3016           // FIXME: This is not the right instruction sequence.
3017           // Use the five byte subl.
3018           memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
3019         }
3020     }
3021
3022   Relocate_functions<32, false>::rel32(view + roff, value);
3023
3024   // The next reloc should be a PLT32 reloc against __tls_get_addr.
3025   // We can skip it.
3026   this->skip_call_tls_get_addr_ = true;
3027 }
3028
3029 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3030 // General-Dynamic to a Local-Exec.
3031
3032 inline void
3033 Target_i386::Relocate::tls_desc_gd_to_le(
3034     const Relocate_info<32, false>* relinfo,
3035     size_t relnum,
3036     Output_segment* tls_segment,
3037     const elfcpp::Rel<32, false>& rel,
3038     unsigned int r_type,
3039     elfcpp::Elf_types<32>::Elf_Addr value,
3040     unsigned char* view,
3041     section_size_type view_size)
3042 {
3043   if (r_type == elfcpp::R_386_TLS_GOTDESC)
3044     {
3045       // leal foo@TLSDESC(%ebx), %eax
3046       // ==> leal foo@NTPOFF, %eax
3047       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3048       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3049       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3050                      view[-2] == 0x8d && view[-1] == 0x83);
3051       view[-1] = 0x05;
3052       value -= tls_segment->memsz();
3053       Relocate_functions<32, false>::rel32(view, value);
3054     }
3055   else
3056     {
3057       // call *foo@TLSCALL(%eax)
3058       // ==> nop; nop
3059       gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
3060       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
3061       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3062                      view[0] == 0xff && view[1] == 0x10);
3063       view[0] = 0x66;
3064       view[1] = 0x90;
3065     }
3066 }
3067
3068 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3069 // General-Dynamic to an Initial-Exec.
3070
3071 inline void
3072 Target_i386::Relocate::tls_desc_gd_to_ie(
3073     const Relocate_info<32, false>* relinfo,
3074     size_t relnum,
3075     Output_segment*,
3076     const elfcpp::Rel<32, false>& rel,
3077     unsigned int r_type,
3078     elfcpp::Elf_types<32>::Elf_Addr value,
3079     unsigned char* view,
3080     section_size_type view_size)
3081 {
3082   if (r_type == elfcpp::R_386_TLS_GOTDESC)
3083     {
3084       // leal foo@TLSDESC(%ebx), %eax
3085       // ==> movl foo@GOTNTPOFF(%ebx), %eax
3086       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3087       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3088       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3089                      view[-2] == 0x8d && view[-1] == 0x83);
3090       view[-2] = 0x8b;
3091       Relocate_functions<32, false>::rel32(view, value);
3092     }
3093   else
3094     {
3095       // call *foo@TLSCALL(%eax)
3096       // ==> nop; nop
3097       gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
3098       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
3099       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3100                      view[0] == 0xff && view[1] == 0x10);
3101       view[0] = 0x66;
3102       view[1] = 0x90;
3103     }
3104 }
3105
3106 // Do a relocation in which we convert a TLS Local-Dynamic to a
3107 // Local-Exec.
3108
3109 inline void
3110 Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo,
3111                                     size_t relnum,
3112                                     Output_segment*,
3113                                     const elfcpp::Rel<32, false>& rel,
3114                                     unsigned int,
3115                                     elfcpp::Elf_types<32>::Elf_Addr,
3116                                     unsigned char* view,
3117                                     section_size_type view_size)
3118 {
3119   // leal foo(%reg), %eax; call ___tls_get_addr
3120   // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
3121
3122   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3123   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
3124
3125   // FIXME: Does this test really always pass?
3126   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3127                  view[-2] == 0x8d && view[-1] == 0x83);
3128
3129   tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
3130
3131   memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
3132
3133   // The next reloc should be a PLT32 reloc against __tls_get_addr.
3134   // We can skip it.
3135   this->skip_call_tls_get_addr_ = true;
3136 }
3137
3138 // Do a relocation in which we convert a TLS Initial-Exec to a
3139 // Local-Exec.
3140
3141 inline void
3142 Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo,
3143                                     size_t relnum,
3144                                     Output_segment* tls_segment,
3145                                     const elfcpp::Rel<32, false>& rel,
3146                                     unsigned int r_type,
3147                                     elfcpp::Elf_types<32>::Elf_Addr value,
3148                                     unsigned char* view,
3149                                     section_size_type view_size)
3150 {
3151   // We have to actually change the instructions, which means that we
3152   // need to examine the opcodes to figure out which instruction we
3153   // are looking at.
3154   if (r_type == elfcpp::R_386_TLS_IE)
3155     {
3156       // movl %gs:XX,%eax  ==>  movl $YY,%eax
3157       // movl %gs:XX,%reg  ==>  movl $YY,%reg
3158       // addl %gs:XX,%reg  ==>  addl $YY,%reg
3159       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -1);
3160       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3161
3162       unsigned char op1 = view[-1];
3163       if (op1 == 0xa1)
3164         {
3165           // movl XX,%eax  ==>  movl $YY,%eax
3166           view[-1] = 0xb8;
3167         }
3168       else
3169         {
3170           tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3171
3172           unsigned char op2 = view[-2];
3173           if (op2 == 0x8b)
3174             {
3175               // movl XX,%reg  ==>  movl $YY,%reg
3176               tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3177                              (op1 & 0xc7) == 0x05);
3178               view[-2] = 0xc7;
3179               view[-1] = 0xc0 | ((op1 >> 3) & 7);
3180             }
3181           else if (op2 == 0x03)
3182             {
3183               // addl XX,%reg  ==>  addl $YY,%reg
3184               tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3185                              (op1 & 0xc7) == 0x05);
3186               view[-2] = 0x81;
3187               view[-1] = 0xc0 | ((op1 >> 3) & 7);
3188             }
3189           else
3190             tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
3191         }
3192     }
3193   else
3194     {
3195       // subl %gs:XX(%reg1),%reg2  ==>  subl $YY,%reg2
3196       // movl %gs:XX(%reg1),%reg2  ==>  movl $YY,%reg2
3197       // addl %gs:XX(%reg1),%reg2  ==>  addl $YY,$reg2
3198       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3199       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3200
3201       unsigned char op1 = view[-1];
3202       unsigned char op2 = view[-2];
3203       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3204                      (op1 & 0xc0) == 0x80 && (op1 & 7) != 4);
3205       if (op2 == 0x8b)
3206         {
3207           // movl %gs:XX(%reg1),%reg2  ==>  movl $YY,%reg2
3208           view[-2] = 0xc7;
3209           view[-1] = 0xc0 | ((op1 >> 3) & 7);
3210         }
3211       else if (op2 == 0x2b)
3212         {
3213           // subl %gs:XX(%reg1),%reg2  ==>  subl $YY,%reg2
3214           view[-2] = 0x81;
3215           view[-1] = 0xe8 | ((op1 >> 3) & 7);
3216         }
3217       else if (op2 == 0x03)
3218         {
3219           // addl %gs:XX(%reg1),%reg2  ==>  addl $YY,$reg2
3220           view[-2] = 0x81;
3221           view[-1] = 0xc0 | ((op1 >> 3) & 7);
3222         }
3223       else
3224         tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
3225     }
3226
3227   value = tls_segment->memsz() - value;
3228   if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE)
3229     value = - value;
3230
3231   Relocate_functions<32, false>::rel32(view, value);
3232 }
3233
3234 // Relocate section data.
3235
3236 void
3237 Target_i386::relocate_section(const Relocate_info<32, false>* relinfo,
3238                               unsigned int sh_type,
3239                               const unsigned char* prelocs,
3240                               size_t reloc_count,
3241                               Output_section* output_section,
3242                               bool needs_special_offset_handling,
3243                               unsigned char* view,
3244                               elfcpp::Elf_types<32>::Elf_Addr address,
3245                               section_size_type view_size,
3246                               const Reloc_symbol_changes* reloc_symbol_changes)
3247 {
3248   gold_assert(sh_type == elfcpp::SHT_REL);
3249
3250   gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL,
3251                          Target_i386::Relocate>(
3252     relinfo,
3253     this,
3254     prelocs,
3255     reloc_count,
3256     output_section,
3257     needs_special_offset_handling,
3258     view,
3259     address,
3260     view_size,
3261     reloc_symbol_changes);
3262 }
3263
3264 // Return the size of a relocation while scanning during a relocatable
3265 // link.
3266
3267 unsigned int
3268 Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
3269     unsigned int r_type,
3270     Relobj* object)
3271 {
3272   switch (r_type)
3273     {
3274     case elfcpp::R_386_NONE:
3275     case elfcpp::R_386_GNU_VTINHERIT:
3276     case elfcpp::R_386_GNU_VTENTRY:
3277     case elfcpp::R_386_TLS_GD:            // Global-dynamic
3278     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
3279     case elfcpp::R_386_TLS_DESC_CALL:
3280     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
3281     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
3282     case elfcpp::R_386_TLS_IE:            // Initial-exec
3283     case elfcpp::R_386_TLS_IE_32:
3284     case elfcpp::R_386_TLS_GOTIE:
3285     case elfcpp::R_386_TLS_LE:            // Local-exec
3286     case elfcpp::R_386_TLS_LE_32:
3287       return 0;
3288
3289     case elfcpp::R_386_32:
3290     case elfcpp::R_386_PC32:
3291     case elfcpp::R_386_GOT32:
3292     case elfcpp::R_386_PLT32:
3293     case elfcpp::R_386_GOTOFF:
3294     case elfcpp::R_386_GOTPC:
3295      return 4;
3296
3297     case elfcpp::R_386_16:
3298     case elfcpp::R_386_PC16:
3299       return 2;
3300
3301     case elfcpp::R_386_8:
3302     case elfcpp::R_386_PC8:
3303       return 1;
3304
3305       // These are relocations which should only be seen by the
3306       // dynamic linker, and should never be seen here.
3307     case elfcpp::R_386_COPY:
3308     case elfcpp::R_386_GLOB_DAT:
3309     case elfcpp::R_386_JUMP_SLOT:
3310     case elfcpp::R_386_RELATIVE:
3311     case elfcpp::R_386_IRELATIVE:
3312     case elfcpp::R_386_TLS_TPOFF:
3313     case elfcpp::R_386_TLS_DTPMOD32:
3314     case elfcpp::R_386_TLS_DTPOFF32:
3315     case elfcpp::R_386_TLS_TPOFF32:
3316     case elfcpp::R_386_TLS_DESC:
3317       object->error(_("unexpected reloc %u in object file"), r_type);
3318       return 0;
3319
3320     case elfcpp::R_386_32PLT:
3321     case elfcpp::R_386_TLS_GD_32:
3322     case elfcpp::R_386_TLS_GD_PUSH:
3323     case elfcpp::R_386_TLS_GD_CALL:
3324     case elfcpp::R_386_TLS_GD_POP:
3325     case elfcpp::R_386_TLS_LDM_32:
3326     case elfcpp::R_386_TLS_LDM_PUSH:
3327     case elfcpp::R_386_TLS_LDM_CALL:
3328     case elfcpp::R_386_TLS_LDM_POP:
3329     case elfcpp::R_386_USED_BY_INTEL_200:
3330     default:
3331       object->error(_("unsupported reloc %u in object file"), r_type);
3332       return 0;
3333     }
3334 }
3335
3336 // Scan the relocs during a relocatable link.
3337
3338 void
3339 Target_i386::scan_relocatable_relocs(Symbol_table* symtab,
3340                                      Layout* layout,
3341                                      Sized_relobj_file<32, false>* object,
3342                                      unsigned int data_shndx,
3343                                      unsigned int sh_type,
3344                                      const unsigned char* prelocs,
3345                                      size_t reloc_count,
3346                                      Output_section* output_section,
3347                                      bool needs_special_offset_handling,
3348                                      size_t local_symbol_count,
3349                                      const unsigned char* plocal_symbols,
3350                                      Relocatable_relocs* rr)
3351 {
3352   gold_assert(sh_type == elfcpp::SHT_REL);
3353
3354   typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_REL,
3355     Relocatable_size_for_reloc> Scan_relocatable_relocs;
3356
3357   gold::scan_relocatable_relocs<32, false, elfcpp::SHT_REL,
3358       Scan_relocatable_relocs>(
3359     symtab,
3360     layout,
3361     object,
3362     data_shndx,
3363     prelocs,
3364     reloc_count,
3365     output_section,
3366     needs_special_offset_handling,
3367     local_symbol_count,
3368     plocal_symbols,
3369     rr);
3370 }
3371
3372 // Relocate a section during a relocatable link.
3373
3374 void
3375 Target_i386::relocate_for_relocatable(
3376     const Relocate_info<32, false>* relinfo,
3377     unsigned int sh_type,
3378     const unsigned char* prelocs,
3379     size_t reloc_count,
3380     Output_section* output_section,
3381     off_t offset_in_output_section,
3382     const Relocatable_relocs* rr,
3383     unsigned char* view,
3384     elfcpp::Elf_types<32>::Elf_Addr view_address,
3385     section_size_type view_size,
3386     unsigned char* reloc_view,
3387     section_size_type reloc_view_size)
3388 {
3389   gold_assert(sh_type == elfcpp::SHT_REL);
3390
3391   gold::relocate_for_relocatable<32, false, elfcpp::SHT_REL>(
3392     relinfo,
3393     prelocs,
3394     reloc_count,
3395     output_section,
3396     offset_in_output_section,
3397     rr,
3398     view,
3399     view_address,
3400     view_size,
3401     reloc_view,
3402     reloc_view_size);
3403 }
3404
3405 // Return the value to use for a dynamic which requires special
3406 // treatment.  This is how we support equality comparisons of function
3407 // pointers across shared library boundaries, as described in the
3408 // processor specific ABI supplement.
3409
3410 uint64_t
3411 Target_i386::do_dynsym_value(const Symbol* gsym) const
3412 {
3413   gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
3414   return this->plt_address_for_global(gsym) + gsym->plt_offset();
3415 }
3416
3417 // Return a string used to fill a code section with nops to take up
3418 // the specified length.
3419
3420 std::string
3421 Target_i386::do_code_fill(section_size_type length) const
3422 {
3423   if (length >= 16)
3424     {
3425       // Build a jmp instruction to skip over the bytes.
3426       unsigned char jmp[5];
3427       jmp[0] = 0xe9;
3428       elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
3429       return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
3430               + std::string(length - 5, '\0'));
3431     }
3432
3433   // Nop sequences of various lengths.
3434   const char nop1[1] = { 0x90 };                   // nop
3435   const char nop2[2] = { 0x66, 0x90 };             // xchg %ax %ax
3436   const char nop3[3] = { 0x8d, 0x76, 0x00 };       // leal 0(%esi),%esi
3437   const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00};  // leal 0(%esi,1),%esi
3438   const char nop5[5] = { 0x90, 0x8d, 0x74, 0x26,   // nop
3439                          0x00 };                   // leal 0(%esi,1),%esi
3440   const char nop6[6] = { 0x8d, 0xb6, 0x00, 0x00,   // leal 0L(%esi),%esi
3441                          0x00, 0x00 };
3442   const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00,   // leal 0L(%esi,1),%esi
3443                          0x00, 0x00, 0x00 };
3444   const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26,   // nop
3445                          0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
3446   const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc,   // movl %esi,%esi
3447                          0x27, 0x00, 0x00, 0x00,   // leal 0L(%edi,1),%edi
3448                          0x00 };
3449   const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
3450                            0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
3451                            0x00, 0x00 };
3452   const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
3453                            0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
3454                            0x00, 0x00, 0x00 };
3455   const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
3456                            0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
3457                            0x00, 0x00, 0x00, 0x00 };
3458   const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
3459                            0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
3460                            0x27, 0x00, 0x00, 0x00,
3461                            0x00 };
3462   const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
3463                            0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
3464                            0xbc, 0x27, 0x00, 0x00,
3465                            0x00, 0x00 };
3466   const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
3467                            0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
3468                            0x90, 0x90, 0x90, 0x90,
3469                            0x90, 0x90, 0x90 };
3470
3471   const char* nops[16] = {
3472     NULL,
3473     nop1, nop2, nop3, nop4, nop5, nop6, nop7,
3474     nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
3475   };
3476
3477   return std::string(nops[length], length);
3478 }
3479
3480 // Return the value to use for the base of a DW_EH_PE_datarel offset
3481 // in an FDE.  Solaris and SVR4 use DW_EH_PE_datarel because their
3482 // assembler can not write out the difference between two labels in
3483 // different sections, so instead of using a pc-relative value they
3484 // use an offset from the GOT.
3485
3486 uint64_t
3487 Target_i386::do_ehframe_datarel_base() const
3488 {
3489   gold_assert(this->global_offset_table_ != NULL);
3490   Symbol* sym = this->global_offset_table_;
3491   Sized_symbol<32>* ssym = static_cast<Sized_symbol<32>*>(sym);
3492   return ssym->value();
3493 }
3494
3495 // Return whether SYM should be treated as a call to a non-split
3496 // function.  We don't want that to be true of a call to a
3497 // get_pc_thunk function.
3498
3499 bool
3500 Target_i386::do_is_call_to_non_split(const Symbol* sym, unsigned int) const
3501 {
3502   return (sym->type() == elfcpp::STT_FUNC
3503           && !is_prefix_of("__i686.get_pc_thunk.", sym->name()));
3504 }
3505
3506 // FNOFFSET in section SHNDX in OBJECT is the start of a function
3507 // compiled with -fsplit-stack.  The function calls non-split-stack
3508 // code.  We have to change the function so that it always ensures
3509 // that it has enough stack space to run some random function.
3510
3511 void
3512 Target_i386::do_calls_non_split(Relobj* object, unsigned int shndx,
3513                                 section_offset_type fnoffset,
3514                                 section_size_type fnsize,
3515                                 unsigned char* view,
3516                                 section_size_type view_size,
3517                                 std::string* from,
3518                                 std::string* to) const
3519 {
3520   // The function starts with a comparison of the stack pointer and a
3521   // field in the TCB.  This is followed by a jump.
3522
3523   // cmp %gs:NN,%esp
3524   if (this->match_view(view, view_size, fnoffset, "\x65\x3b\x25", 3)
3525       && fnsize > 7)
3526     {
3527       // We will call __morestack if the carry flag is set after this
3528       // comparison.  We turn the comparison into an stc instruction
3529       // and some nops.
3530       view[fnoffset] = '\xf9';
3531       this->set_view_to_nop(view, view_size, fnoffset + 1, 6);
3532     }
3533   // lea NN(%esp),%ecx
3534   // lea NN(%esp),%edx
3535   else if ((this->match_view(view, view_size, fnoffset, "\x8d\x8c\x24", 3)
3536             || this->match_view(view, view_size, fnoffset, "\x8d\x94\x24", 3))
3537            && fnsize > 7)
3538     {
3539       // This is loading an offset from the stack pointer for a
3540       // comparison.  The offset is negative, so we decrease the
3541       // offset by the amount of space we need for the stack.  This
3542       // means we will avoid calling __morestack if there happens to
3543       // be plenty of space on the stack already.
3544       unsigned char* pval = view + fnoffset + 3;
3545       uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
3546       val -= parameters->options().split_stack_adjust_size();
3547       elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
3548     }
3549   else
3550     {
3551       if (!object->has_no_split_stack())
3552         object->error(_("failed to match split-stack sequence at "
3553                         "section %u offset %0zx"),
3554                       shndx, static_cast<size_t>(fnoffset));
3555       return;
3556     }
3557
3558   // We have to change the function so that it calls
3559   // __morestack_non_split instead of __morestack.  The former will
3560   // allocate additional stack space.
3561   *from = "__morestack";
3562   *to = "__morestack_non_split";
3563 }
3564
3565 // The selector for i386 object files.
3566
3567 class Target_selector_i386 : public Target_selector_freebsd
3568 {
3569 public:
3570   Target_selector_i386()
3571     : Target_selector_freebsd(elfcpp::EM_386, 32, false,
3572                               "elf32-i386", "elf32-i386-freebsd",
3573                               "elf_i386")
3574   { }
3575
3576   Target*
3577   do_instantiate_target()
3578   { return new Target_i386(); }
3579 };
3580
3581 Target_selector_i386 target_selector_i386;
3582
3583 } // End anonymous namespace.