PR gold/12392
[external/binutils.git] / 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(Symbol_table*, Layout*, Output_data_space*);
57
58   // Add an entry to the PLT.
59   void
60   add_entry(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(Sized_relobj_file<32, false>* relobj,
65                         unsigned int local_sym_index);
66
67   // Return the .rel.plt section data.
68   Reloc_section*
69   rel_plt() const
70   { return this->rel_; }
71
72   // Return where the TLS_DESC relocations should go.
73   Reloc_section*
74   rel_tls_desc(Layout*);
75
76   // Return the number of PLT entries.
77   unsigned int
78   entry_count() const
79   { return this->count_; }
80
81   // Return the offset of the first non-reserved PLT entry.
82   static unsigned int
83   first_plt_entry_offset()
84   { return plt_entry_size; }
85
86   // Return the size of a PLT entry.
87   static unsigned int
88   get_plt_entry_size()
89   { return plt_entry_size; }
90
91  protected:
92   void
93   do_adjust_output_section(Output_section* os);
94
95   // Write to a map file.
96   void
97   do_print_to_mapfile(Mapfile* mapfile) const
98   { mapfile->print_output_data(this, _("** PLT")); }
99
100  private:
101   // The size of an entry in the PLT.
102   static const int plt_entry_size = 16;
103
104   // The first entry in the PLT for an executable.
105   static const unsigned char exec_first_plt_entry[plt_entry_size];
106
107   // The first entry in the PLT for a shared object.
108   static const unsigned char dyn_first_plt_entry[plt_entry_size];
109
110   // Other entries in the PLT for an executable.
111   static const unsigned char exec_plt_entry[plt_entry_size];
112
113   // Other entries in the PLT for a shared object.
114   static const unsigned char dyn_plt_entry[plt_entry_size];
115
116   // The .eh_frame unwind information for the PLT.
117   static const int plt_eh_frame_cie_size = 16;
118   static const int plt_eh_frame_fde_size = 32;
119   static const unsigned char plt_eh_frame_cie[plt_eh_frame_cie_size];
120   static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
121
122   // Set the final size.
123   void
124   set_final_data_size()
125   { this->set_data_size((this->count_ + 1) * plt_entry_size); }
126
127   // Write out the PLT data.
128   void
129   do_write(Output_file*);
130
131   // We keep a list of global STT_GNU_IFUNC symbols, each with its
132   // offset in the GOT.
133   struct Global_ifunc
134   {
135     Symbol* sym;
136     unsigned int got_offset;
137   };
138
139   // We keep a list of local STT_GNU_IFUNC symbols, each with its
140   // offset in the GOT.
141   struct Local_ifunc
142   {
143     Sized_relobj_file<32, false>* object;
144     unsigned int local_sym_index;
145     unsigned int got_offset;
146   };
147
148   // The reloc section.
149   Reloc_section* rel_;
150   // The TLS_DESC relocations, if necessary.  These must follow the
151   // regular PLT relocs.
152   Reloc_section* tls_desc_rel_;
153   // The .got.plt section.
154   Output_data_space* got_plt_;
155   // The number of PLT entries.
156   unsigned int count_;
157   // Global STT_GNU_IFUNC symbols.
158   std::vector<Global_ifunc> global_ifuncs_;
159   // Local STT_GNU_IFUNC symbols.
160   std::vector<Local_ifunc> local_ifuncs_;
161 };
162
163 // The i386 target class.
164 // TLS info comes from
165 //   http://people.redhat.com/drepper/tls.pdf
166 //   http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
167
168 class Target_i386 : public Sized_target<32, false>
169 {
170  public:
171   typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
172
173   Target_i386()
174     : Sized_target<32, false>(&i386_info),
175       got_(NULL), plt_(NULL), got_plt_(NULL), got_tlsdesc_(NULL),
176       global_offset_table_(NULL), rel_dyn_(NULL),
177       copy_relocs_(elfcpp::R_386_COPY), dynbss_(NULL),
178       got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
179   { }
180
181   // Process the relocations to determine unreferenced sections for 
182   // garbage collection.
183   void
184   gc_process_relocs(Symbol_table* symtab,
185                     Layout* layout,
186                     Sized_relobj_file<32, false>* object,
187                     unsigned int data_shndx,
188                     unsigned int sh_type,
189                     const unsigned char* prelocs,
190                     size_t reloc_count,
191                     Output_section* output_section,
192                     bool needs_special_offset_handling,
193                     size_t local_symbol_count,
194                     const unsigned char* plocal_symbols);
195
196   // Scan the relocations to look for symbol adjustments.
197   void
198   scan_relocs(Symbol_table* symtab,
199               Layout* layout,
200               Sized_relobj_file<32, false>* object,
201               unsigned int data_shndx,
202               unsigned int sh_type,
203               const unsigned char* prelocs,
204               size_t reloc_count,
205               Output_section* output_section,
206               bool needs_special_offset_handling,
207               size_t local_symbol_count,
208               const unsigned char* plocal_symbols);
209
210   // Finalize the sections.
211   void
212   do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
213
214   // Return the value to use for a dynamic which requires special
215   // treatment.
216   uint64_t
217   do_dynsym_value(const Symbol*) const;
218
219   // Relocate a section.
220   void
221   relocate_section(const Relocate_info<32, false>*,
222                    unsigned int sh_type,
223                    const unsigned char* prelocs,
224                    size_t reloc_count,
225                    Output_section* output_section,
226                    bool needs_special_offset_handling,
227                    unsigned char* view,
228                    elfcpp::Elf_types<32>::Elf_Addr view_address,
229                    section_size_type view_size,
230                    const Reloc_symbol_changes*);
231
232   // Scan the relocs during a relocatable link.
233   void
234   scan_relocatable_relocs(Symbol_table* symtab,
235                           Layout* layout,
236                           Sized_relobj_file<32, false>* object,
237                           unsigned int data_shndx,
238                           unsigned int sh_type,
239                           const unsigned char* prelocs,
240                           size_t reloc_count,
241                           Output_section* output_section,
242                           bool needs_special_offset_handling,
243                           size_t local_symbol_count,
244                           const unsigned char* plocal_symbols,
245                           Relocatable_relocs*);
246
247   // Relocate a section during a relocatable link.
248   void
249   relocate_for_relocatable(const Relocate_info<32, false>*,
250                            unsigned int sh_type,
251                            const unsigned char* prelocs,
252                            size_t reloc_count,
253                            Output_section* output_section,
254                            off_t offset_in_output_section,
255                            const Relocatable_relocs*,
256                            unsigned char* view,
257                            elfcpp::Elf_types<32>::Elf_Addr view_address,
258                            section_size_type view_size,
259                            unsigned char* reloc_view,
260                            section_size_type reloc_view_size);
261
262   // Return a string used to fill a code section with nops.
263   std::string
264   do_code_fill(section_size_type length) const;
265
266   // Return whether SYM is defined by the ABI.
267   bool
268   do_is_defined_by_abi(const Symbol* sym) const
269   { return strcmp(sym->name(), "___tls_get_addr") == 0; }
270
271   // Return whether a symbol name implies a local label.  The UnixWare
272   // 2.1 cc generates temporary symbols that start with .X, so we
273   // recognize them here.  FIXME: do other SVR4 compilers also use .X?.
274   // If so, we should move the .X recognition into
275   // Target::do_is_local_label_name.
276   bool
277   do_is_local_label_name(const char* name) const
278   {
279     if (name[0] == '.' && name[1] == 'X')
280       return true;
281     return Target::do_is_local_label_name(name);
282   }
283
284   // Return the PLT section.
285   Output_data*
286   do_plt_section_for_global(const Symbol*) const
287   { return this->plt_section(); }
288
289   Output_data*
290   do_plt_section_for_local(const Relobj*, unsigned int) const
291   { return this->plt_section(); }
292
293   // We can tell whether we take the address of a function.
294   inline bool
295   do_can_check_for_function_pointers() const
296   { return true; }
297
298   // Return the base for a DW_EH_PE_datarel encoding.
299   uint64_t
300   do_ehframe_datarel_base() const;
301
302   // Return whether SYM is call to a non-split function.
303   bool
304   do_is_call_to_non_split(const Symbol* sym, unsigned int) const;
305
306   // Adjust -fsplit-stack code which calls non-split-stack code.
307   void
308   do_calls_non_split(Relobj* object, unsigned int shndx,
309                      section_offset_type fnoffset, section_size_type fnsize,
310                      unsigned char* view, section_size_type view_size,
311                      std::string* from, std::string* to) const;
312
313   // Return the size of the GOT section.
314   section_size_type
315   got_size() const
316   {
317     gold_assert(this->got_ != NULL);
318     return this->got_->data_size();
319   }
320
321   // Return the number of entries in the GOT.
322   unsigned int
323   got_entry_count() const
324   {
325     if (this->got_ == NULL)
326       return 0;
327     return this->got_size() / 4;
328   }
329
330   // Return the number of entries in the PLT.
331   unsigned int
332   plt_entry_count() const;
333
334   // Return the offset of the first non-reserved PLT entry.
335   unsigned int
336   first_plt_entry_offset() const;
337
338   // Return the size of each PLT entry.
339   unsigned int
340   plt_entry_size() const;
341
342  private:
343   // The class which scans relocations.
344   struct Scan
345   {
346     static inline int
347
348     get_reference_flags(unsigned int r_type);
349
350     inline void
351     local(Symbol_table* symtab, Layout* layout, Target_i386* target,
352           Sized_relobj_file<32, false>* object,
353           unsigned int data_shndx,
354           Output_section* output_section,
355           const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
356           const elfcpp::Sym<32, false>& lsym);
357
358     inline void
359     global(Symbol_table* symtab, Layout* layout, Target_i386* target,
360            Sized_relobj_file<32, false>* object,
361            unsigned int data_shndx,
362            Output_section* output_section,
363            const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
364            Symbol* gsym);
365
366     inline bool
367     local_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
368                                         Target_i386* target,
369                                         Sized_relobj_file<32, false>* object,
370                                         unsigned int data_shndx,
371                                         Output_section* output_section,
372                                         const elfcpp::Rel<32, false>& reloc,
373                                         unsigned int r_type,
374                                         const elfcpp::Sym<32, false>& lsym);
375
376     inline bool
377     global_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
378                                          Target_i386* target,
379                                          Sized_relobj_file<32, false>* object,
380                                          unsigned int data_shndx,
381                                          Output_section* output_section,
382                                          const elfcpp::Rel<32, false>& reloc,
383                                          unsigned int r_type,
384                                          Symbol* gsym);
385
386     inline bool
387     possible_function_pointer_reloc(unsigned int r_type);
388
389     bool
390     reloc_needs_plt_for_ifunc(Sized_relobj_file<32, false>*,
391                               unsigned int r_type);
392
393     static void
394     unsupported_reloc_local(Sized_relobj_file<32, false>*, unsigned int r_type);
395
396     static void
397     unsupported_reloc_global(Sized_relobj_file<32, false>*, unsigned int r_type,
398                              Symbol*);
399   };
400
401   // The class which implements relocation.
402   class Relocate
403   {
404    public:
405     Relocate()
406       : skip_call_tls_get_addr_(false),
407         local_dynamic_type_(LOCAL_DYNAMIC_NONE)
408     { }
409
410     ~Relocate()
411     {
412       if (this->skip_call_tls_get_addr_)
413         {
414           // FIXME: This needs to specify the location somehow.
415           gold_error(_("missing expected TLS relocation"));
416         }
417     }
418
419     // Return whether the static relocation needs to be applied.
420     inline bool
421     should_apply_static_reloc(const Sized_symbol<32>* gsym,
422                               unsigned int r_type,
423                               bool is_32bit,
424                               Output_section* output_section);
425
426     // Do a relocation.  Return false if the caller should not issue
427     // any warnings about this relocation.
428     inline bool
429     relocate(const Relocate_info<32, false>*, Target_i386*, Output_section*,
430              size_t relnum, const elfcpp::Rel<32, false>&,
431              unsigned int r_type, const Sized_symbol<32>*,
432              const Symbol_value<32>*,
433              unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
434              section_size_type);
435
436    private:
437     // Do a TLS relocation.
438     inline void
439     relocate_tls(const Relocate_info<32, false>*, Target_i386* target,
440                  size_t relnum, const elfcpp::Rel<32, false>&,
441                  unsigned int r_type, const Sized_symbol<32>*,
442                  const Symbol_value<32>*,
443                  unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
444                  section_size_type);
445
446     // Do a TLS General-Dynamic to Initial-Exec transition.
447     inline void
448     tls_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
449                  Output_segment* tls_segment,
450                  const elfcpp::Rel<32, false>&, unsigned int r_type,
451                  elfcpp::Elf_types<32>::Elf_Addr value,
452                  unsigned char* view,
453                  section_size_type view_size);
454
455     // Do a TLS General-Dynamic to Local-Exec transition.
456     inline void
457     tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
458                  Output_segment* tls_segment,
459                  const elfcpp::Rel<32, false>&, unsigned int r_type,
460                  elfcpp::Elf_types<32>::Elf_Addr value,
461                  unsigned char* view,
462                  section_size_type view_size);
463
464     // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
465     // transition.
466     inline void
467     tls_desc_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
468                       Output_segment* tls_segment,
469                       const elfcpp::Rel<32, false>&, unsigned int r_type,
470                       elfcpp::Elf_types<32>::Elf_Addr value,
471                       unsigned char* view,
472                       section_size_type view_size);
473
474     // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
475     // transition.
476     inline void
477     tls_desc_gd_to_le(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 Local-Dynamic to Local-Exec transition.
485     inline void
486     tls_ld_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 Initial-Exec to Local-Exec transition.
494     static inline void
495     tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum,
496                  Output_segment* tls_segment,
497                  const elfcpp::Rel<32, false>&, unsigned int r_type,
498                  elfcpp::Elf_types<32>::Elf_Addr value,
499                  unsigned char* view,
500                  section_size_type view_size);
501
502     // We need to keep track of which type of local dynamic relocation
503     // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
504     enum Local_dynamic_type
505     {
506       LOCAL_DYNAMIC_NONE,
507       LOCAL_DYNAMIC_SUN,
508       LOCAL_DYNAMIC_GNU
509     };
510
511     // This is set if we should skip the next reloc, which should be a
512     // PLT32 reloc against ___tls_get_addr.
513     bool skip_call_tls_get_addr_;
514     // The type of local dynamic relocation we have seen in the section
515     // being relocated, if any.
516     Local_dynamic_type local_dynamic_type_;
517   };
518
519   // A class which returns the size required for a relocation type,
520   // used while scanning relocs during a relocatable link.
521   class Relocatable_size_for_reloc
522   {
523    public:
524     unsigned int
525     get_size_for_reloc(unsigned int, Relobj*);
526   };
527
528   // Adjust TLS relocation type based on the options and whether this
529   // is a local symbol.
530   static tls::Tls_optimization
531   optimize_tls_reloc(bool is_final, int r_type);
532
533   // Get the GOT section, creating it if necessary.
534   Output_data_got<32, false>*
535   got_section(Symbol_table*, Layout*);
536
537   // Get the GOT PLT section.
538   Output_data_space*
539   got_plt_section() const
540   {
541     gold_assert(this->got_plt_ != NULL);
542     return this->got_plt_;
543   }
544
545   // Get the GOT section for TLSDESC entries.
546   Output_data_got<32, false>*
547   got_tlsdesc_section() const
548   {
549     gold_assert(this->got_tlsdesc_ != NULL);
550     return this->got_tlsdesc_;
551   }
552
553   // Create the PLT section.
554   void
555   make_plt_section(Symbol_table* symtab, Layout* layout);
556
557   // Create a PLT entry for a global symbol.
558   void
559   make_plt_entry(Symbol_table*, Layout*, Symbol*);
560
561   // Create a PLT entry for a local STT_GNU_IFUNC symbol.
562   void
563   make_local_ifunc_plt_entry(Symbol_table*, Layout*,
564                              Sized_relobj_file<32, false>* relobj,
565                              unsigned int local_sym_index);
566
567   // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
568   void
569   define_tls_base_symbol(Symbol_table*, Layout*);
570
571   // Create a GOT entry for the TLS module index.
572   unsigned int
573   got_mod_index_entry(Symbol_table* symtab, Layout* layout,
574                       Sized_relobj_file<32, false>* object);
575
576   // Get the PLT section.
577   Output_data_plt_i386*
578   plt_section() const
579   {
580     gold_assert(this->plt_ != NULL);
581     return this->plt_;
582   }
583
584   // Get the dynamic reloc section, creating it if necessary.
585   Reloc_section*
586   rel_dyn_section(Layout*);
587
588   // Get the section to use for TLS_DESC relocations.
589   Reloc_section*
590   rel_tls_desc_section(Layout*) const;
591
592   // Add a potential copy relocation.
593   void
594   copy_reloc(Symbol_table* symtab, Layout* layout,
595              Sized_relobj_file<32, false>* object,
596              unsigned int shndx, Output_section* output_section,
597              Symbol* sym, const elfcpp::Rel<32, false>& reloc)
598   {
599     this->copy_relocs_.copy_reloc(symtab, layout,
600                                   symtab->get_sized_symbol<32>(sym),
601                                   object, shndx, output_section, reloc,
602                                   this->rel_dyn_section(layout));
603   }
604
605   // Information about this specific target which we pass to the
606   // general Target structure.
607   static const Target::Target_info i386_info;
608
609   // The types of GOT entries needed for this platform.
610   // These values are exposed to the ABI in an incremental link.
611   // Do not renumber existing values without changing the version
612   // number of the .gnu_incremental_inputs section.
613   enum Got_type
614   {
615     GOT_TYPE_STANDARD = 0,      // GOT entry for a regular symbol
616     GOT_TYPE_TLS_NOFFSET = 1,   // GOT entry for negative TLS offset
617     GOT_TYPE_TLS_OFFSET = 2,    // GOT entry for positive TLS offset
618     GOT_TYPE_TLS_PAIR = 3,      // GOT entry for TLS module/offset pair
619     GOT_TYPE_TLS_DESC = 4       // GOT entry for TLS_DESC pair
620   };
621
622   // The GOT section.
623   Output_data_got<32, false>* got_;
624   // The PLT section.
625   Output_data_plt_i386* plt_;
626   // The GOT PLT section.
627   Output_data_space* got_plt_;
628   // The GOT section for TLSDESC relocations.
629   Output_data_got<32, false>* got_tlsdesc_;
630   // The _GLOBAL_OFFSET_TABLE_ symbol.
631   Symbol* global_offset_table_;
632   // The dynamic reloc section.
633   Reloc_section* rel_dyn_;
634   // Relocs saved to avoid a COPY reloc.
635   Copy_relocs<elfcpp::SHT_REL, 32, false> copy_relocs_;
636   // Space for variables copied with a COPY reloc.
637   Output_data_space* dynbss_;
638   // Offset of the GOT entry for the TLS module index.
639   unsigned int got_mod_index_offset_;
640   // True if the _TLS_MODULE_BASE_ symbol has been defined.
641   bool tls_base_symbol_defined_;
642 };
643
644 const Target::Target_info Target_i386::i386_info =
645 {
646   32,                   // size
647   false,                // is_big_endian
648   elfcpp::EM_386,       // machine_code
649   false,                // has_make_symbol
650   false,                // has_resolve
651   true,                 // has_code_fill
652   true,                 // is_default_stack_executable
653   true,                 // can_icf_inline_merge_sections
654   '\0',                 // wrap_char
655   "/usr/lib/libc.so.1", // dynamic_linker
656   0x08048000,           // default_text_segment_address
657   0x1000,               // abi_pagesize (overridable by -z max-page-size)
658   0x1000,               // common_pagesize (overridable by -z common-page-size)
659   elfcpp::SHN_UNDEF,    // small_common_shndx
660   elfcpp::SHN_UNDEF,    // large_common_shndx
661   0,                    // small_common_section_flags
662   0,                    // large_common_section_flags
663   NULL,                 // attributes_section
664   NULL                  // attributes_vendor
665 };
666
667 // Get the GOT section, creating it if necessary.
668
669 Output_data_got<32, false>*
670 Target_i386::got_section(Symbol_table* symtab, Layout* layout)
671 {
672   if (this->got_ == NULL)
673     {
674       gold_assert(symtab != NULL && layout != NULL);
675
676       this->got_ = new Output_data_got<32, false>();
677
678       layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
679                                       (elfcpp::SHF_ALLOC
680                                        | elfcpp::SHF_WRITE),
681                                       this->got_, ORDER_RELRO_LAST, true);
682
683       this->got_plt_ = new Output_data_space(4, "** GOT PLT");
684       layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
685                                       (elfcpp::SHF_ALLOC
686                                        | elfcpp::SHF_WRITE),
687                                       this->got_plt_, ORDER_NON_RELRO_FIRST,
688                                       false);
689
690       // The first three entries are reserved.
691       this->got_plt_->set_current_data_size(3 * 4);
692
693       // Those bytes can go into the relro segment.
694       layout->increase_relro(3 * 4);
695
696       // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
697       this->global_offset_table_ =
698         symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
699                                       Symbol_table::PREDEFINED,
700                                       this->got_plt_,
701                                       0, 0, elfcpp::STT_OBJECT,
702                                       elfcpp::STB_LOCAL,
703                                       elfcpp::STV_HIDDEN, 0,
704                                       false, false);
705
706       // If there are any TLSDESC relocations, they get GOT entries in
707       // .got.plt after the jump slot entries.
708       this->got_tlsdesc_ = new Output_data_got<32, false>();
709       layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
710                                       (elfcpp::SHF_ALLOC
711                                        | elfcpp::SHF_WRITE),
712                                       this->got_tlsdesc_,
713                                       ORDER_NON_RELRO_FIRST, false);
714     }
715
716   return this->got_;
717 }
718
719 // Get the dynamic reloc section, creating it if necessary.
720
721 Target_i386::Reloc_section*
722 Target_i386::rel_dyn_section(Layout* layout)
723 {
724   if (this->rel_dyn_ == NULL)
725     {
726       gold_assert(layout != NULL);
727       this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
728       layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
729                                       elfcpp::SHF_ALLOC, this->rel_dyn_,
730                                       ORDER_DYNAMIC_RELOCS, false);
731     }
732   return this->rel_dyn_;
733 }
734
735 // Create the PLT section.  The ordinary .got section is an argument,
736 // since we need to refer to the start.  We also create our own .got
737 // section just for PLT entries.
738
739 Output_data_plt_i386::Output_data_plt_i386(Symbol_table* symtab,
740                                            Layout* layout,
741                                            Output_data_space* got_plt)
742   : Output_section_data(16), tls_desc_rel_(NULL), got_plt_(got_plt), count_(0),
743     global_ifuncs_(), local_ifuncs_()
744 {
745   this->rel_ = new Reloc_section(false);
746   layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
747                                   elfcpp::SHF_ALLOC, this->rel_,
748                                   ORDER_DYNAMIC_PLT_RELOCS, false);
749
750   if (parameters->doing_static_link())
751     {
752       // A statically linked executable will only have a .rel.plt
753       // section to hold R_386_IRELATIVE relocs for STT_GNU_IFUNC
754       // symbols.  The library will use these symbols to locate the
755       // IRELATIVE relocs at program startup time.
756       symtab->define_in_output_data("__rel_iplt_start", NULL,
757                                     Symbol_table::PREDEFINED,
758                                     this->rel_, 0, 0, elfcpp::STT_NOTYPE,
759                                     elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN,
760                                     0, false, true);
761       symtab->define_in_output_data("__rel_iplt_end", NULL,
762                                     Symbol_table::PREDEFINED,
763                                     this->rel_, 0, 0, elfcpp::STT_NOTYPE,
764                                     elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN,
765                                     0, true, true);
766     }
767
768   // Add unwind information if requested.
769   if (parameters->options().ld_generated_unwind_info())
770     layout->add_eh_frame_for_plt(this, plt_eh_frame_cie, plt_eh_frame_cie_size,
771                                  plt_eh_frame_fde, plt_eh_frame_fde_size);
772 }
773
774 void
775 Output_data_plt_i386::do_adjust_output_section(Output_section* os)
776 {
777   // UnixWare sets the entsize of .plt to 4, and so does the old GNU
778   // linker, and so do we.
779   os->set_entsize(4);
780 }
781
782 // Add an entry to the PLT.
783
784 void
785 Output_data_plt_i386::add_entry(Symbol* gsym)
786 {
787   gold_assert(!gsym->has_plt_offset());
788
789   // Note that when setting the PLT offset we skip the initial
790   // reserved PLT entry.
791   gsym->set_plt_offset((this->count_ + 1) * plt_entry_size);
792
793   ++this->count_;
794
795   section_offset_type got_offset = this->got_plt_->current_data_size();
796
797   // Every PLT entry needs a GOT entry which points back to the PLT
798   // entry (this will be changed by the dynamic linker, normally
799   // lazily when the function is called).
800   this->got_plt_->set_current_data_size(got_offset + 4);
801
802   // Every PLT entry needs a reloc.
803   if (gsym->type() == elfcpp::STT_GNU_IFUNC
804       && gsym->can_use_relative_reloc(false))
805     {
806       this->rel_->add_symbolless_global_addend(gsym, elfcpp::R_386_IRELATIVE,
807                                                this->got_plt_, got_offset);
808       struct Global_ifunc gi;
809       gi.sym = gsym;
810       gi.got_offset = got_offset;
811       this->global_ifuncs_.push_back(gi);
812     }
813   else
814     {
815       gsym->set_needs_dynsym_entry();
816       this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_,
817                              got_offset);
818     }
819
820   // Note that we don't need to save the symbol.  The contents of the
821   // PLT are independent of which symbols are used.  The symbols only
822   // appear in the relocations.
823 }
824
825 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.  Return
826 // the PLT offset.
827
828 unsigned int
829 Output_data_plt_i386::add_local_ifunc_entry(
830     Sized_relobj_file<32, false>* relobj,
831     unsigned int local_sym_index)
832 {
833   unsigned int plt_offset = (this->count_ + 1) * plt_entry_size;
834   ++this->count_;
835
836   section_offset_type got_offset = this->got_plt_->current_data_size();
837
838   // Every PLT entry needs a GOT entry which points back to the PLT
839   // entry.
840   this->got_plt_->set_current_data_size(got_offset + 4);
841
842   // Every PLT entry needs a reloc.
843   this->rel_->add_symbolless_local_addend(relobj, local_sym_index,
844                                           elfcpp::R_386_IRELATIVE,
845                                           this->got_plt_, got_offset);
846
847   struct Local_ifunc li;
848   li.object = relobj;
849   li.local_sym_index = local_sym_index;
850   li.got_offset = got_offset;
851   this->local_ifuncs_.push_back(li);
852
853   return plt_offset;
854 }
855
856 // Return where the TLS_DESC relocations should go, creating it if
857 // necessary. These follow the JUMP_SLOT relocations.
858
859 Output_data_plt_i386::Reloc_section*
860 Output_data_plt_i386::rel_tls_desc(Layout* layout)
861 {
862   if (this->tls_desc_rel_ == NULL)
863     {
864       this->tls_desc_rel_ = new Reloc_section(false);
865       layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
866                                       elfcpp::SHF_ALLOC, this->tls_desc_rel_,
867                                       ORDER_DYNAMIC_PLT_RELOCS, false);
868       gold_assert(this->tls_desc_rel_->output_section() ==
869                   this->rel_->output_section());
870     }
871   return this->tls_desc_rel_;
872 }
873
874 // The first entry in the PLT for an executable.
875
876 const unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] =
877 {
878   0xff, 0x35,   // pushl contents of memory address
879   0, 0, 0, 0,   // replaced with address of .got + 4
880   0xff, 0x25,   // jmp indirect
881   0, 0, 0, 0,   // replaced with address of .got + 8
882   0, 0, 0, 0    // unused
883 };
884
885 // The first entry in the PLT for a shared object.
886
887 const unsigned char Output_data_plt_i386::dyn_first_plt_entry[plt_entry_size] =
888 {
889   0xff, 0xb3, 4, 0, 0, 0,       // pushl 4(%ebx)
890   0xff, 0xa3, 8, 0, 0, 0,       // jmp *8(%ebx)
891   0, 0, 0, 0                    // unused
892 };
893
894 // Subsequent entries in the PLT for an executable.
895
896 const unsigned char Output_data_plt_i386::exec_plt_entry[plt_entry_size] =
897 {
898   0xff, 0x25,   // jmp indirect
899   0, 0, 0, 0,   // replaced with address of symbol in .got
900   0x68,         // pushl immediate
901   0, 0, 0, 0,   // replaced with offset into relocation table
902   0xe9,         // jmp relative
903   0, 0, 0, 0    // replaced with offset to start of .plt
904 };
905
906 // Subsequent entries in the PLT for a shared object.
907
908 const unsigned char Output_data_plt_i386::dyn_plt_entry[plt_entry_size] =
909 {
910   0xff, 0xa3,   // jmp *offset(%ebx)
911   0, 0, 0, 0,   // replaced with offset of symbol in .got
912   0x68,         // pushl immediate
913   0, 0, 0, 0,   // replaced with offset into relocation table
914   0xe9,         // jmp relative
915   0, 0, 0, 0    // replaced with offset to start of .plt
916 };
917
918 // The .eh_frame unwind information for the PLT.
919
920 const unsigned char
921 Output_data_plt_i386::plt_eh_frame_cie[plt_eh_frame_cie_size] =
922 {
923   1,                            // CIE version.
924   'z',                          // Augmentation: augmentation size included.
925   'R',                          // Augmentation: FDE encoding included.
926   '\0',                         // End of augmentation string.
927   1,                            // Code alignment factor.
928   0x7c,                         // Data alignment factor.
929   8,                            // Return address column.
930   1,                            // Augmentation size.
931   (elfcpp::DW_EH_PE_pcrel       // FDE encoding.
932    | elfcpp::DW_EH_PE_sdata4),
933   elfcpp::DW_CFA_def_cfa, 4, 4, // DW_CFA_def_cfa: r4 (esp) ofs 4.
934   elfcpp::DW_CFA_offset + 8, 1, // DW_CFA_offset: r8 (eip) at cfa-4.
935   elfcpp::DW_CFA_nop,           // Align to 16 bytes.
936   elfcpp::DW_CFA_nop
937 };
938
939 const unsigned char
940 Output_data_plt_i386::plt_eh_frame_fde[plt_eh_frame_fde_size] =
941 {
942   0, 0, 0, 0,                           // Replaced with offset to .plt.
943   0, 0, 0, 0,                           // Replaced with size of .plt.
944   0,                                    // Augmentation size.
945   elfcpp::DW_CFA_def_cfa_offset, 8,     // DW_CFA_def_cfa_offset: 8.
946   elfcpp::DW_CFA_advance_loc + 6,       // Advance 6 to __PLT__ + 6.
947   elfcpp::DW_CFA_def_cfa_offset, 12,    // DW_CFA_def_cfa_offset: 12.
948   elfcpp::DW_CFA_advance_loc + 10,      // Advance 10 to __PLT__ + 16.
949   elfcpp::DW_CFA_def_cfa_expression,    // DW_CFA_def_cfa_expression.
950   11,                                   // Block length.
951   elfcpp::DW_OP_breg4, 4,               // Push %esp + 4.
952   elfcpp::DW_OP_breg8, 0,               // Push %eip.
953   elfcpp::DW_OP_lit15,                  // Push 0xf.
954   elfcpp::DW_OP_and,                    // & (%eip & 0xf).
955   elfcpp::DW_OP_lit11,                  // Push 0xb.
956   elfcpp::DW_OP_ge,                     // >= ((%eip & 0xf) >= 0xb)
957   elfcpp::DW_OP_lit2,                   // Push 2.
958   elfcpp::DW_OP_shl,                    // << (((%eip & 0xf) >= 0xb) << 2)
959   elfcpp::DW_OP_plus,                   // + ((((%eip&0xf)>=0xb)<<2)+%esp+4
960   elfcpp::DW_CFA_nop,                   // Align to 32 bytes.
961   elfcpp::DW_CFA_nop,
962   elfcpp::DW_CFA_nop,
963   elfcpp::DW_CFA_nop
964 };
965
966 // Write out the PLT.  This uses the hand-coded instructions above,
967 // and adjusts them as needed.  This is all specified by the i386 ELF
968 // Processor Supplement.
969
970 void
971 Output_data_plt_i386::do_write(Output_file* of)
972 {
973   const off_t offset = this->offset();
974   const section_size_type oview_size =
975     convert_to_section_size_type(this->data_size());
976   unsigned char* const oview = of->get_output_view(offset, oview_size);
977
978   const off_t got_file_offset = this->got_plt_->offset();
979   const section_size_type got_size =
980     convert_to_section_size_type(this->got_plt_->data_size());
981   unsigned char* const got_view = of->get_output_view(got_file_offset,
982                                                       got_size);
983
984   unsigned char* pov = oview;
985
986   elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address();
987   elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address();
988
989   if (parameters->options().output_is_position_independent())
990     memcpy(pov, dyn_first_plt_entry, plt_entry_size);
991   else
992     {
993       memcpy(pov, exec_first_plt_entry, plt_entry_size);
994       elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
995       elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
996     }
997   pov += plt_entry_size;
998
999   unsigned char* got_pov = got_view;
1000
1001   memset(got_pov, 0, 12);
1002   got_pov += 12;
1003
1004   const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
1005
1006   unsigned int plt_offset = plt_entry_size;
1007   unsigned int plt_rel_offset = 0;
1008   unsigned int got_offset = 12;
1009   const unsigned int count = this->count_;
1010   for (unsigned int i = 0;
1011        i < count;
1012        ++i,
1013          pov += plt_entry_size,
1014          got_pov += 4,
1015          plt_offset += plt_entry_size,
1016          plt_rel_offset += rel_size,
1017          got_offset += 4)
1018     {
1019       // Set and adjust the PLT entry itself.
1020
1021       if (parameters->options().output_is_position_independent())
1022         {
1023           memcpy(pov, dyn_plt_entry, plt_entry_size);
1024           elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
1025         }
1026       else
1027         {
1028           memcpy(pov, exec_plt_entry, plt_entry_size);
1029           elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1030                                                       (got_address
1031                                                        + got_offset));
1032         }
1033
1034       elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
1035       elfcpp::Swap<32, false>::writeval(pov + 12,
1036                                         - (plt_offset + plt_entry_size));
1037
1038       // Set the entry in the GOT.
1039       elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6);
1040     }
1041
1042   // If any STT_GNU_IFUNC symbols have PLT entries, we need to change
1043   // the GOT to point to the actual symbol value, rather than point to
1044   // the PLT entry.  That will let the dynamic linker call the right
1045   // function when resolving IRELATIVE relocations.
1046   for (std::vector<Global_ifunc>::const_iterator p =
1047          this->global_ifuncs_.begin();
1048        p != this->global_ifuncs_.end();
1049        ++p)
1050     {
1051       const Sized_symbol<32>* ssym =
1052         static_cast<const Sized_symbol<32>*>(p->sym);
1053       elfcpp::Swap<32, false>::writeval(got_view + p->got_offset,
1054                                         ssym->value());
1055     }
1056
1057   for (std::vector<Local_ifunc>::const_iterator p =
1058          this->local_ifuncs_.begin();
1059        p != this->local_ifuncs_.end();
1060        ++p)
1061     {
1062       const Symbol_value<32>* psymval =
1063         p->object->local_symbol(p->local_sym_index);
1064       elfcpp::Swap<32, false>::writeval(got_view + p->got_offset,
1065                                         psymval->value(p->object, 0));
1066     }
1067
1068   gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
1069   gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
1070
1071   of->write_output_view(offset, oview_size, oview);
1072   of->write_output_view(got_file_offset, got_size, got_view);
1073 }
1074
1075 // Create the PLT section.
1076
1077 void
1078 Target_i386::make_plt_section(Symbol_table* symtab, Layout* layout)
1079 {
1080   if (this->plt_ == NULL)
1081     {
1082       // Create the GOT sections first.
1083       this->got_section(symtab, layout);
1084
1085       this->plt_ = new Output_data_plt_i386(symtab, layout, this->got_plt_);
1086       layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
1087                                       (elfcpp::SHF_ALLOC
1088                                        | elfcpp::SHF_EXECINSTR),
1089                                       this->plt_, ORDER_PLT, false);
1090
1091       // Make the sh_info field of .rel.plt point to .plt.
1092       Output_section* rel_plt_os = this->plt_->rel_plt()->output_section();
1093       rel_plt_os->set_info_section(this->plt_->output_section());
1094     }
1095 }
1096
1097 // Create a PLT entry for a global symbol.
1098
1099 void
1100 Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym)
1101 {
1102   if (gsym->has_plt_offset())
1103     return;
1104   if (this->plt_ == NULL)
1105     this->make_plt_section(symtab, layout);
1106   this->plt_->add_entry(gsym);
1107 }
1108
1109 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1110
1111 void
1112 Target_i386::make_local_ifunc_plt_entry(Symbol_table* symtab, Layout* layout,
1113                                         Sized_relobj_file<32, false>* relobj,
1114                                         unsigned int local_sym_index)
1115 {
1116   if (relobj->local_has_plt_offset(local_sym_index))
1117     return;
1118   if (this->plt_ == NULL)
1119     this->make_plt_section(symtab, layout);
1120   unsigned int plt_offset = this->plt_->add_local_ifunc_entry(relobj,
1121                                                               local_sym_index);
1122   relobj->set_local_plt_offset(local_sym_index, plt_offset);
1123 }
1124
1125 // Return the number of entries in the PLT.
1126
1127 unsigned int
1128 Target_i386::plt_entry_count() const
1129 {
1130   if (this->plt_ == NULL)
1131     return 0;
1132   return this->plt_->entry_count();
1133 }
1134
1135 // Return the offset of the first non-reserved PLT entry.
1136
1137 unsigned int
1138 Target_i386::first_plt_entry_offset() const
1139 {
1140   return Output_data_plt_i386::first_plt_entry_offset();
1141 }
1142
1143 // Return the size of each PLT entry.
1144
1145 unsigned int
1146 Target_i386::plt_entry_size() const
1147 {
1148   return Output_data_plt_i386::get_plt_entry_size();
1149 }
1150
1151 // Get the section to use for TLS_DESC relocations.
1152
1153 Target_i386::Reloc_section*
1154 Target_i386::rel_tls_desc_section(Layout* layout) const
1155 {
1156   return this->plt_section()->rel_tls_desc(layout);
1157 }
1158
1159 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1160
1161 void
1162 Target_i386::define_tls_base_symbol(Symbol_table* symtab, Layout* layout)
1163 {
1164   if (this->tls_base_symbol_defined_)
1165     return;
1166
1167   Output_segment* tls_segment = layout->tls_segment();
1168   if (tls_segment != NULL)
1169     {
1170       bool is_exec = parameters->options().output_is_executable();
1171       symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
1172                                        Symbol_table::PREDEFINED,
1173                                        tls_segment, 0, 0,
1174                                        elfcpp::STT_TLS,
1175                                        elfcpp::STB_LOCAL,
1176                                        elfcpp::STV_HIDDEN, 0,
1177                                        (is_exec
1178                                         ? Symbol::SEGMENT_END
1179                                         : Symbol::SEGMENT_START),
1180                                        true);
1181     }
1182   this->tls_base_symbol_defined_ = true;
1183 }
1184
1185 // Create a GOT entry for the TLS module index.
1186
1187 unsigned int
1188 Target_i386::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
1189                                  Sized_relobj_file<32, false>* object)
1190 {
1191   if (this->got_mod_index_offset_ == -1U)
1192     {
1193       gold_assert(symtab != NULL && layout != NULL && object != NULL);
1194       Reloc_section* rel_dyn = this->rel_dyn_section(layout);
1195       Output_data_got<32, false>* got = this->got_section(symtab, layout);
1196       unsigned int got_offset = got->add_constant(0);
1197       rel_dyn->add_local(object, 0, elfcpp::R_386_TLS_DTPMOD32, got,
1198                          got_offset);
1199       got->add_constant(0);
1200       this->got_mod_index_offset_ = got_offset;
1201     }
1202   return this->got_mod_index_offset_;
1203 }
1204
1205 // Optimize the TLS relocation type based on what we know about the
1206 // symbol.  IS_FINAL is true if the final address of this symbol is
1207 // known at link time.
1208
1209 tls::Tls_optimization
1210 Target_i386::optimize_tls_reloc(bool is_final, int r_type)
1211 {
1212   // If we are generating a shared library, then we can't do anything
1213   // in the linker.
1214   if (parameters->options().shared())
1215     return tls::TLSOPT_NONE;
1216
1217   switch (r_type)
1218     {
1219     case elfcpp::R_386_TLS_GD:
1220     case elfcpp::R_386_TLS_GOTDESC:
1221     case elfcpp::R_386_TLS_DESC_CALL:
1222       // These are General-Dynamic which permits fully general TLS
1223       // access.  Since we know that we are generating an executable,
1224       // we can convert this to Initial-Exec.  If we also know that
1225       // this is a local symbol, we can further switch to Local-Exec.
1226       if (is_final)
1227         return tls::TLSOPT_TO_LE;
1228       return tls::TLSOPT_TO_IE;
1229
1230     case elfcpp::R_386_TLS_LDM:
1231       // This is Local-Dynamic, which refers to a local symbol in the
1232       // dynamic TLS block.  Since we know that we generating an
1233       // executable, we can switch to Local-Exec.
1234       return tls::TLSOPT_TO_LE;
1235
1236     case elfcpp::R_386_TLS_LDO_32:
1237       // Another type of Local-Dynamic relocation.
1238       return tls::TLSOPT_TO_LE;
1239
1240     case elfcpp::R_386_TLS_IE:
1241     case elfcpp::R_386_TLS_GOTIE:
1242     case elfcpp::R_386_TLS_IE_32:
1243       // These are Initial-Exec relocs which get the thread offset
1244       // from the GOT.  If we know that we are linking against the
1245       // local symbol, we can switch to Local-Exec, which links the
1246       // thread offset into the instruction.
1247       if (is_final)
1248         return tls::TLSOPT_TO_LE;
1249       return tls::TLSOPT_NONE;
1250
1251     case elfcpp::R_386_TLS_LE:
1252     case elfcpp::R_386_TLS_LE_32:
1253       // When we already have Local-Exec, there is nothing further we
1254       // can do.
1255       return tls::TLSOPT_NONE;
1256
1257     default:
1258       gold_unreachable();
1259     }
1260 }
1261
1262 // Get the Reference_flags for a particular relocation.
1263
1264 int
1265 Target_i386::Scan::get_reference_flags(unsigned int r_type)
1266 {
1267   switch (r_type)
1268     {
1269     case elfcpp::R_386_NONE:
1270     case elfcpp::R_386_GNU_VTINHERIT:
1271     case elfcpp::R_386_GNU_VTENTRY:
1272     case elfcpp::R_386_GOTPC:
1273       // No symbol reference.
1274       return 0;
1275
1276     case elfcpp::R_386_32:
1277     case elfcpp::R_386_16:
1278     case elfcpp::R_386_8:
1279       return Symbol::ABSOLUTE_REF;
1280
1281     case elfcpp::R_386_PC32:
1282     case elfcpp::R_386_PC16:
1283     case elfcpp::R_386_PC8:
1284     case elfcpp::R_386_GOTOFF:
1285       return Symbol::RELATIVE_REF;
1286
1287     case elfcpp::R_386_PLT32:
1288       return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
1289
1290     case elfcpp::R_386_GOT32:
1291       // Absolute in GOT.
1292       return Symbol::ABSOLUTE_REF;
1293
1294     case elfcpp::R_386_TLS_GD:            // Global-dynamic
1295     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
1296     case elfcpp::R_386_TLS_DESC_CALL:
1297     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
1298     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
1299     case elfcpp::R_386_TLS_IE:            // Initial-exec
1300     case elfcpp::R_386_TLS_IE_32:
1301     case elfcpp::R_386_TLS_GOTIE:
1302     case elfcpp::R_386_TLS_LE:            // Local-exec
1303     case elfcpp::R_386_TLS_LE_32:
1304       return Symbol::TLS_REF;
1305
1306     case elfcpp::R_386_COPY:
1307     case elfcpp::R_386_GLOB_DAT:
1308     case elfcpp::R_386_JUMP_SLOT:
1309     case elfcpp::R_386_RELATIVE:
1310     case elfcpp::R_386_IRELATIVE:
1311     case elfcpp::R_386_TLS_TPOFF:
1312     case elfcpp::R_386_TLS_DTPMOD32:
1313     case elfcpp::R_386_TLS_DTPOFF32:
1314     case elfcpp::R_386_TLS_TPOFF32:
1315     case elfcpp::R_386_TLS_DESC:
1316     case elfcpp::R_386_32PLT:
1317     case elfcpp::R_386_TLS_GD_32:
1318     case elfcpp::R_386_TLS_GD_PUSH:
1319     case elfcpp::R_386_TLS_GD_CALL:
1320     case elfcpp::R_386_TLS_GD_POP:
1321     case elfcpp::R_386_TLS_LDM_32:
1322     case elfcpp::R_386_TLS_LDM_PUSH:
1323     case elfcpp::R_386_TLS_LDM_CALL:
1324     case elfcpp::R_386_TLS_LDM_POP:
1325     case elfcpp::R_386_USED_BY_INTEL_200:
1326     default:
1327       // Not expected.  We will give an error later.
1328       return 0;
1329     }
1330 }
1331
1332 // Report an unsupported relocation against a local symbol.
1333
1334 void
1335 Target_i386::Scan::unsupported_reloc_local(Sized_relobj_file<32, false>* object,
1336                                            unsigned int r_type)
1337 {
1338   gold_error(_("%s: unsupported reloc %u against local symbol"),
1339              object->name().c_str(), r_type);
1340 }
1341
1342 // Return whether we need to make a PLT entry for a relocation of a
1343 // given type against a STT_GNU_IFUNC symbol.
1344
1345 bool
1346 Target_i386::Scan::reloc_needs_plt_for_ifunc(
1347     Sized_relobj_file<32, false>* object,
1348     unsigned int r_type)
1349 {
1350   int flags = Scan::get_reference_flags(r_type);
1351   if (flags & Symbol::TLS_REF)
1352     gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
1353                object->name().c_str(), r_type);
1354   return flags != 0;
1355 }
1356
1357 // Scan a relocation for a local symbol.
1358
1359 inline void
1360 Target_i386::Scan::local(Symbol_table* symtab,
1361                          Layout* layout,
1362                          Target_i386* target,
1363                          Sized_relobj_file<32, false>* object,
1364                          unsigned int data_shndx,
1365                          Output_section* output_section,
1366                          const elfcpp::Rel<32, false>& reloc,
1367                          unsigned int r_type,
1368                          const elfcpp::Sym<32, false>& lsym)
1369 {
1370   // A local STT_GNU_IFUNC symbol may require a PLT entry.
1371   if (lsym.get_st_type() == elfcpp::STT_GNU_IFUNC
1372       && this->reloc_needs_plt_for_ifunc(object, r_type))
1373     {
1374       unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1375       target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
1376     }
1377
1378   switch (r_type)
1379     {
1380     case elfcpp::R_386_NONE:
1381     case elfcpp::R_386_GNU_VTINHERIT:
1382     case elfcpp::R_386_GNU_VTENTRY:
1383       break;
1384
1385     case elfcpp::R_386_32:
1386       // If building a shared library (or a position-independent
1387       // executable), we need to create a dynamic relocation for
1388       // this location. The relocation applied at link time will
1389       // apply the link-time value, so we flag the location with
1390       // an R_386_RELATIVE relocation so the dynamic loader can
1391       // relocate it easily.
1392       if (parameters->options().output_is_position_independent())
1393         {
1394           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1395           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1396           rel_dyn->add_local_relative(object, r_sym, elfcpp::R_386_RELATIVE,
1397                                       output_section, data_shndx,
1398                                       reloc.get_r_offset());
1399         }
1400       break;
1401
1402     case elfcpp::R_386_16:
1403     case elfcpp::R_386_8:
1404       // If building a shared library (or a position-independent
1405       // executable), we need to create a dynamic relocation for
1406       // this location. Because the addend needs to remain in the
1407       // data section, we need to be careful not to apply this
1408       // relocation statically.
1409       if (parameters->options().output_is_position_independent())
1410         {
1411           Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1412           unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1413           if (lsym.get_st_type() != elfcpp::STT_SECTION)
1414             rel_dyn->add_local(object, r_sym, r_type, output_section,
1415                                data_shndx, reloc.get_r_offset());
1416           else
1417             {
1418               gold_assert(lsym.get_st_value() == 0);
1419               unsigned int shndx = lsym.get_st_shndx();
1420               bool is_ordinary;
1421               shndx = object->adjust_sym_shndx(r_sym, shndx,
1422                                                &is_ordinary);
1423               if (!is_ordinary)
1424                 object->error(_("section symbol %u has bad shndx %u"),
1425                               r_sym, shndx);
1426               else
1427                 rel_dyn->add_local_section(object, shndx,
1428                                            r_type, output_section,
1429                                            data_shndx, reloc.get_r_offset());
1430             }
1431         }
1432       break;
1433
1434     case elfcpp::R_386_PC32:
1435     case elfcpp::R_386_PC16:
1436     case elfcpp::R_386_PC8:
1437       break;
1438
1439     case elfcpp::R_386_PLT32:
1440       // Since we know this is a local symbol, we can handle this as a
1441       // PC32 reloc.
1442       break;
1443
1444     case elfcpp::R_386_GOTOFF:
1445     case elfcpp::R_386_GOTPC:
1446       // We need a GOT section.
1447       target->got_section(symtab, layout);
1448       break;
1449
1450     case elfcpp::R_386_GOT32:
1451       {
1452         // The symbol requires a GOT entry.
1453         Output_data_got<32, false>* got = target->got_section(symtab, layout);
1454         unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1455
1456         // For a STT_GNU_IFUNC symbol we want the PLT offset.  That
1457         // lets function pointers compare correctly with shared
1458         // libraries.  Otherwise we would need an IRELATIVE reloc.
1459         bool is_new;
1460         if (lsym.get_st_type() == elfcpp::STT_GNU_IFUNC)
1461           is_new = got->add_local_plt(object, r_sym, GOT_TYPE_STANDARD);
1462         else
1463           is_new = got->add_local(object, r_sym, GOT_TYPE_STANDARD);
1464         if (is_new)
1465           {
1466             // If we are generating a shared object, we need to add a
1467             // dynamic RELATIVE relocation for this symbol's GOT entry.
1468             if (parameters->options().output_is_position_independent())
1469               {
1470                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1471                 unsigned int got_offset =
1472                   object->local_got_offset(r_sym, GOT_TYPE_STANDARD);
1473                 rel_dyn->add_local_relative(object, r_sym,
1474                                             elfcpp::R_386_RELATIVE,
1475                                             got, got_offset);
1476               }
1477           }
1478       }
1479       break;
1480
1481       // These are relocations which should only be seen by the
1482       // dynamic linker, and should never be seen here.
1483     case elfcpp::R_386_COPY:
1484     case elfcpp::R_386_GLOB_DAT:
1485     case elfcpp::R_386_JUMP_SLOT:
1486     case elfcpp::R_386_RELATIVE:
1487     case elfcpp::R_386_IRELATIVE:
1488     case elfcpp::R_386_TLS_TPOFF:
1489     case elfcpp::R_386_TLS_DTPMOD32:
1490     case elfcpp::R_386_TLS_DTPOFF32:
1491     case elfcpp::R_386_TLS_TPOFF32:
1492     case elfcpp::R_386_TLS_DESC:
1493       gold_error(_("%s: unexpected reloc %u in object file"),
1494                  object->name().c_str(), r_type);
1495       break;
1496
1497       // These are initial TLS relocs, which are expected when
1498       // linking.
1499     case elfcpp::R_386_TLS_GD:            // Global-dynamic
1500     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
1501     case elfcpp::R_386_TLS_DESC_CALL:
1502     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
1503     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
1504     case elfcpp::R_386_TLS_IE:            // Initial-exec
1505     case elfcpp::R_386_TLS_IE_32:
1506     case elfcpp::R_386_TLS_GOTIE:
1507     case elfcpp::R_386_TLS_LE:            // Local-exec
1508     case elfcpp::R_386_TLS_LE_32:
1509       {
1510         bool output_is_shared = parameters->options().shared();
1511         const tls::Tls_optimization optimized_type
1512             = Target_i386::optimize_tls_reloc(!output_is_shared, r_type);
1513         switch (r_type)
1514           {
1515           case elfcpp::R_386_TLS_GD:          // Global-dynamic
1516             if (optimized_type == tls::TLSOPT_NONE)
1517               {
1518                 // Create a pair of GOT entries for the module index and
1519                 // dtv-relative offset.
1520                 Output_data_got<32, false>* got
1521                     = target->got_section(symtab, layout);
1522                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1523                 unsigned int shndx = lsym.get_st_shndx();
1524                 bool is_ordinary;
1525                 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
1526                 if (!is_ordinary)
1527                   object->error(_("local symbol %u has bad shndx %u"),
1528                               r_sym, shndx);
1529                 else
1530                   got->add_local_pair_with_rel(object, r_sym, shndx,
1531                                                GOT_TYPE_TLS_PAIR,
1532                                                target->rel_dyn_section(layout),
1533                                                elfcpp::R_386_TLS_DTPMOD32, 0);
1534               }
1535             else if (optimized_type != tls::TLSOPT_TO_LE)
1536               unsupported_reloc_local(object, r_type);
1537             break;
1538
1539           case elfcpp::R_386_TLS_GOTDESC:     // Global-dynamic (from ~oliva)
1540             target->define_tls_base_symbol(symtab, layout);
1541             if (optimized_type == tls::TLSOPT_NONE)
1542               {
1543                 // Create a double GOT entry with an R_386_TLS_DESC
1544                 // reloc.  The R_386_TLS_DESC reloc is resolved
1545                 // lazily, so the GOT entry needs to be in an area in
1546                 // .got.plt, not .got.  Call got_section to make sure
1547                 // the section has been created.
1548                 target->got_section(symtab, layout);
1549                 Output_data_got<32, false>* got = target->got_tlsdesc_section();
1550                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1551                 if (!object->local_has_got_offset(r_sym, GOT_TYPE_TLS_DESC))
1552                   {
1553                     unsigned int got_offset = got->add_constant(0);
1554                     // The local symbol value is stored in the second
1555                     // GOT entry.
1556                     got->add_local(object, r_sym, GOT_TYPE_TLS_DESC);
1557                     // That set the GOT offset of the local symbol to
1558                     // point to the second entry, but we want it to
1559                     // point to the first.
1560                     object->set_local_got_offset(r_sym, GOT_TYPE_TLS_DESC,
1561                                                  got_offset);
1562                     Reloc_section* rt = target->rel_tls_desc_section(layout);
1563                     rt->add_absolute(elfcpp::R_386_TLS_DESC, got, got_offset);
1564                   }
1565               }
1566             else if (optimized_type != tls::TLSOPT_TO_LE)
1567               unsupported_reloc_local(object, r_type);
1568             break;
1569
1570           case elfcpp::R_386_TLS_DESC_CALL:
1571             break;
1572
1573           case elfcpp::R_386_TLS_LDM:         // Local-dynamic
1574             if (optimized_type == tls::TLSOPT_NONE)
1575               {
1576                 // Create a GOT entry for the module index.
1577                 target->got_mod_index_entry(symtab, layout, object);
1578               }
1579             else if (optimized_type != tls::TLSOPT_TO_LE)
1580               unsupported_reloc_local(object, r_type);
1581             break;
1582
1583           case elfcpp::R_386_TLS_LDO_32:      // Alternate local-dynamic
1584             break;
1585
1586           case elfcpp::R_386_TLS_IE:          // Initial-exec
1587           case elfcpp::R_386_TLS_IE_32:
1588           case elfcpp::R_386_TLS_GOTIE:
1589             layout->set_has_static_tls();
1590             if (optimized_type == tls::TLSOPT_NONE)
1591               {
1592                 // For the R_386_TLS_IE relocation, we need to create a
1593                 // dynamic relocation when building a shared library.
1594                 if (r_type == elfcpp::R_386_TLS_IE
1595                     && parameters->options().shared())
1596                   {
1597                     Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1598                     unsigned int r_sym
1599                         = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1600                     rel_dyn->add_local_relative(object, r_sym,
1601                                                 elfcpp::R_386_RELATIVE,
1602                                                 output_section, data_shndx,
1603                                                 reloc.get_r_offset());
1604                   }
1605                 // Create a GOT entry for the tp-relative offset.
1606                 Output_data_got<32, false>* got
1607                     = target->got_section(symtab, layout);
1608                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1609                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
1610                                            ? elfcpp::R_386_TLS_TPOFF32
1611                                            : elfcpp::R_386_TLS_TPOFF);
1612                 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
1613                                          ? GOT_TYPE_TLS_OFFSET
1614                                          : GOT_TYPE_TLS_NOFFSET);
1615                 got->add_local_with_rel(object, r_sym, got_type,
1616                                         target->rel_dyn_section(layout),
1617                                         dyn_r_type);
1618               }
1619             else if (optimized_type != tls::TLSOPT_TO_LE)
1620               unsupported_reloc_local(object, r_type);
1621             break;
1622
1623           case elfcpp::R_386_TLS_LE:          // Local-exec
1624           case elfcpp::R_386_TLS_LE_32:
1625             layout->set_has_static_tls();
1626             if (output_is_shared)
1627               {
1628                 // We need to create a dynamic relocation.
1629                 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
1630                 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
1631                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
1632                                            ? elfcpp::R_386_TLS_TPOFF32
1633                                            : elfcpp::R_386_TLS_TPOFF);
1634                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1635                 rel_dyn->add_local(object, r_sym, dyn_r_type, output_section,
1636                                    data_shndx, reloc.get_r_offset());
1637               }
1638             break;
1639
1640           default:
1641             gold_unreachable();
1642           }
1643       }
1644       break;
1645
1646     case elfcpp::R_386_32PLT:
1647     case elfcpp::R_386_TLS_GD_32:
1648     case elfcpp::R_386_TLS_GD_PUSH:
1649     case elfcpp::R_386_TLS_GD_CALL:
1650     case elfcpp::R_386_TLS_GD_POP:
1651     case elfcpp::R_386_TLS_LDM_32:
1652     case elfcpp::R_386_TLS_LDM_PUSH:
1653     case elfcpp::R_386_TLS_LDM_CALL:
1654     case elfcpp::R_386_TLS_LDM_POP:
1655     case elfcpp::R_386_USED_BY_INTEL_200:
1656     default:
1657       unsupported_reloc_local(object, r_type);
1658       break;
1659     }
1660 }
1661
1662 // Report an unsupported relocation against a global symbol.
1663
1664 void
1665 Target_i386::Scan::unsupported_reloc_global(
1666     Sized_relobj_file<32, false>* object,
1667     unsigned int r_type,
1668     Symbol* gsym)
1669 {
1670   gold_error(_("%s: unsupported reloc %u against global symbol %s"),
1671              object->name().c_str(), r_type, gsym->demangled_name().c_str());
1672 }
1673
1674 inline bool
1675 Target_i386::Scan::possible_function_pointer_reloc(unsigned int r_type)
1676 {
1677   switch (r_type)
1678     {
1679     case elfcpp::R_386_32:
1680     case elfcpp::R_386_16:
1681     case elfcpp::R_386_8:
1682     case elfcpp::R_386_GOTOFF:
1683     case elfcpp::R_386_GOT32:
1684       {
1685         return true;
1686       }
1687     default:
1688       return false;
1689     }
1690   return false;
1691 }
1692
1693 inline bool
1694 Target_i386::Scan::local_reloc_may_be_function_pointer(
1695   Symbol_table* ,
1696   Layout* ,
1697   Target_i386* ,
1698   Sized_relobj_file<32, false>* ,
1699   unsigned int ,
1700   Output_section* ,
1701   const elfcpp::Rel<32, false>& ,
1702   unsigned int r_type,
1703   const elfcpp::Sym<32, false>&)
1704 {
1705   return possible_function_pointer_reloc(r_type);
1706 }
1707
1708 inline bool
1709 Target_i386::Scan::global_reloc_may_be_function_pointer(
1710   Symbol_table* ,
1711   Layout* ,
1712   Target_i386* ,
1713   Sized_relobj_file<32, false>* ,
1714   unsigned int ,
1715   Output_section* ,
1716   const elfcpp::Rel<32, false>& ,
1717   unsigned int r_type,
1718   Symbol*)
1719 {
1720   return possible_function_pointer_reloc(r_type);
1721 }
1722
1723 // Scan a relocation for a global symbol.
1724
1725 inline void
1726 Target_i386::Scan::global(Symbol_table* symtab,
1727                           Layout* layout,
1728                           Target_i386* target,
1729                           Sized_relobj_file<32, false>* object,
1730                           unsigned int data_shndx,
1731                           Output_section* output_section,
1732                           const elfcpp::Rel<32, false>& reloc,
1733                           unsigned int r_type,
1734                           Symbol* gsym)
1735 {
1736   // A STT_GNU_IFUNC symbol may require a PLT entry.
1737   if (gsym->type() == elfcpp::STT_GNU_IFUNC
1738       && this->reloc_needs_plt_for_ifunc(object, r_type))
1739     target->make_plt_entry(symtab, layout, gsym);
1740
1741   switch (r_type)
1742     {
1743     case elfcpp::R_386_NONE:
1744     case elfcpp::R_386_GNU_VTINHERIT:
1745     case elfcpp::R_386_GNU_VTENTRY:
1746       break;
1747
1748     case elfcpp::R_386_32:
1749     case elfcpp::R_386_16:
1750     case elfcpp::R_386_8:
1751       {
1752         // Make a PLT entry if necessary.
1753         if (gsym->needs_plt_entry())
1754           {
1755             target->make_plt_entry(symtab, layout, gsym);
1756             // Since this is not a PC-relative relocation, we may be
1757             // taking the address of a function. In that case we need to
1758             // set the entry in the dynamic symbol table to the address of
1759             // the PLT entry.
1760             if (gsym->is_from_dynobj() && !parameters->options().shared())
1761               gsym->set_needs_dynsym_value();
1762           }
1763         // Make a dynamic relocation if necessary.
1764         if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
1765           {
1766             if (gsym->may_need_copy_reloc())
1767               {
1768                 target->copy_reloc(symtab, layout, object,
1769                                    data_shndx, output_section, gsym, reloc);
1770               }
1771             else if (r_type == elfcpp::R_386_32
1772                      && gsym->type() == elfcpp::STT_GNU_IFUNC
1773                      && gsym->can_use_relative_reloc(false)
1774                      && !gsym->is_from_dynobj()
1775                      && !gsym->is_undefined()
1776                      && !gsym->is_preemptible())
1777               {
1778                 // Use an IRELATIVE reloc for a locally defined
1779                 // STT_GNU_IFUNC symbol.  This makes a function
1780                 // address in a PIE executable match the address in a
1781                 // shared library that it links against.
1782                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1783                 rel_dyn->add_symbolless_global_addend(gsym,
1784                                                       elfcpp::R_386_IRELATIVE,
1785                                                       output_section,
1786                                                       object, data_shndx,
1787                                                       reloc.get_r_offset());
1788               }
1789             else if (r_type == elfcpp::R_386_32
1790                      && gsym->can_use_relative_reloc(false))
1791               {
1792                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1793                 rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1794                                              output_section, object,
1795                                              data_shndx, reloc.get_r_offset());
1796               }
1797             else
1798               {
1799                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1800                 rel_dyn->add_global(gsym, r_type, output_section, object,
1801                                     data_shndx, reloc.get_r_offset());
1802               }
1803           }
1804       }
1805       break;
1806
1807     case elfcpp::R_386_PC32:
1808     case elfcpp::R_386_PC16:
1809     case elfcpp::R_386_PC8:
1810       {
1811         // Make a PLT entry if necessary.
1812         if (gsym->needs_plt_entry())
1813           {
1814             // These relocations are used for function calls only in
1815             // non-PIC code.  For a 32-bit relocation in a shared library,
1816             // we'll need a text relocation anyway, so we can skip the
1817             // PLT entry and let the dynamic linker bind the call directly
1818             // to the target.  For smaller relocations, we should use a
1819             // PLT entry to ensure that the call can reach.
1820             if (!parameters->options().shared()
1821                 || r_type != elfcpp::R_386_PC32)
1822               target->make_plt_entry(symtab, layout, gsym);
1823           }
1824         // Make a dynamic relocation if necessary.
1825         if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
1826           {
1827             if (gsym->may_need_copy_reloc())
1828               {
1829                 target->copy_reloc(symtab, layout, object,
1830                                    data_shndx, output_section, gsym, reloc);
1831               }
1832             else
1833               {
1834                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1835                 rel_dyn->add_global(gsym, r_type, output_section, object,
1836                                     data_shndx, reloc.get_r_offset());
1837               }
1838           }
1839       }
1840       break;
1841
1842     case elfcpp::R_386_GOT32:
1843       {
1844         // The symbol requires a GOT entry.
1845         Output_data_got<32, false>* got = target->got_section(symtab, layout);
1846         if (gsym->final_value_is_known())
1847           {
1848             // For a STT_GNU_IFUNC symbol we want the PLT address.
1849             if (gsym->type() == elfcpp::STT_GNU_IFUNC)
1850               got->add_global_plt(gsym, GOT_TYPE_STANDARD);
1851             else
1852               got->add_global(gsym, GOT_TYPE_STANDARD);
1853           }
1854         else
1855           {
1856             // If this symbol is not fully resolved, we need to add a
1857             // GOT entry with a dynamic relocation.
1858             Reloc_section* rel_dyn = target->rel_dyn_section(layout);
1859             if (gsym->is_from_dynobj()
1860                 || gsym->is_undefined()
1861                 || gsym->is_preemptible()
1862                 || (gsym->type() == elfcpp::STT_GNU_IFUNC
1863                     && parameters->options().output_is_position_independent()))
1864               got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
1865                                        rel_dyn, elfcpp::R_386_GLOB_DAT);
1866             else
1867               {
1868                 // For a STT_GNU_IFUNC symbol we want to write the PLT
1869                 // offset into the GOT, so that function pointer
1870                 // comparisons work correctly.
1871                 bool is_new;
1872                 if (gsym->type() != elfcpp::STT_GNU_IFUNC)
1873                   is_new = got->add_global(gsym, GOT_TYPE_STANDARD);
1874                 else
1875                   {
1876                     is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD);
1877                     // Tell the dynamic linker to use the PLT address
1878                     // when resolving relocations.
1879                     if (gsym->is_from_dynobj()
1880                         && !parameters->options().shared())
1881                       gsym->set_needs_dynsym_value();
1882                   }
1883                 if (is_new)
1884                   {
1885                     unsigned int got_off = gsym->got_offset(GOT_TYPE_STANDARD);
1886                     rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
1887                                                  got, got_off);
1888                   }
1889               }
1890           }
1891       }
1892       break;
1893
1894     case elfcpp::R_386_PLT32:
1895       // If the symbol is fully resolved, this is just a PC32 reloc.
1896       // Otherwise we need a PLT entry.
1897       if (gsym->final_value_is_known())
1898         break;
1899       // If building a shared library, we can also skip the PLT entry
1900       // if the symbol is defined in the output file and is protected
1901       // or hidden.
1902       if (gsym->is_defined()
1903           && !gsym->is_from_dynobj()
1904           && !gsym->is_preemptible())
1905         break;
1906       target->make_plt_entry(symtab, layout, gsym);
1907       break;
1908
1909     case elfcpp::R_386_GOTOFF:
1910     case elfcpp::R_386_GOTPC:
1911       // We need a GOT section.
1912       target->got_section(symtab, layout);
1913       break;
1914
1915       // These are relocations which should only be seen by the
1916       // dynamic linker, and should never be seen here.
1917     case elfcpp::R_386_COPY:
1918     case elfcpp::R_386_GLOB_DAT:
1919     case elfcpp::R_386_JUMP_SLOT:
1920     case elfcpp::R_386_RELATIVE:
1921     case elfcpp::R_386_IRELATIVE:
1922     case elfcpp::R_386_TLS_TPOFF:
1923     case elfcpp::R_386_TLS_DTPMOD32:
1924     case elfcpp::R_386_TLS_DTPOFF32:
1925     case elfcpp::R_386_TLS_TPOFF32:
1926     case elfcpp::R_386_TLS_DESC:
1927       gold_error(_("%s: unexpected reloc %u in object file"),
1928                  object->name().c_str(), r_type);
1929       break;
1930
1931       // These are initial tls relocs, which are expected when
1932       // linking.
1933     case elfcpp::R_386_TLS_GD:            // Global-dynamic
1934     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
1935     case elfcpp::R_386_TLS_DESC_CALL:
1936     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
1937     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
1938     case elfcpp::R_386_TLS_IE:            // Initial-exec
1939     case elfcpp::R_386_TLS_IE_32:
1940     case elfcpp::R_386_TLS_GOTIE:
1941     case elfcpp::R_386_TLS_LE:            // Local-exec
1942     case elfcpp::R_386_TLS_LE_32:
1943       {
1944         const bool is_final = gsym->final_value_is_known();
1945         const tls::Tls_optimization optimized_type
1946             = Target_i386::optimize_tls_reloc(is_final, r_type);
1947         switch (r_type)
1948           {
1949           case elfcpp::R_386_TLS_GD:          // Global-dynamic
1950             if (optimized_type == tls::TLSOPT_NONE)
1951               {
1952                 // Create a pair of GOT entries for the module index and
1953                 // dtv-relative offset.
1954                 Output_data_got<32, false>* got
1955                     = target->got_section(symtab, layout);
1956                 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
1957                                              target->rel_dyn_section(layout),
1958                                              elfcpp::R_386_TLS_DTPMOD32,
1959                                              elfcpp::R_386_TLS_DTPOFF32);
1960               }
1961             else if (optimized_type == tls::TLSOPT_TO_IE)
1962               {
1963                 // Create a GOT entry for the tp-relative offset.
1964                 Output_data_got<32, false>* got
1965                     = target->got_section(symtab, layout);
1966                 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
1967                                          target->rel_dyn_section(layout),
1968                                          elfcpp::R_386_TLS_TPOFF);
1969               }
1970             else if (optimized_type != tls::TLSOPT_TO_LE)
1971               unsupported_reloc_global(object, r_type, gsym);
1972             break;
1973
1974           case elfcpp::R_386_TLS_GOTDESC:     // Global-dynamic (~oliva url)
1975             target->define_tls_base_symbol(symtab, layout);
1976             if (optimized_type == tls::TLSOPT_NONE)
1977               {
1978                 // Create a double GOT entry with an R_386_TLS_DESC
1979                 // reloc.  The R_386_TLS_DESC reloc is resolved
1980                 // lazily, so the GOT entry needs to be in an area in
1981                 // .got.plt, not .got.  Call got_section to make sure
1982                 // the section has been created.
1983                 target->got_section(symtab, layout);
1984                 Output_data_got<32, false>* got = target->got_tlsdesc_section();
1985                 Reloc_section* rt = target->rel_tls_desc_section(layout);
1986                 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC, rt,
1987                                              elfcpp::R_386_TLS_DESC, 0);
1988               }
1989             else if (optimized_type == tls::TLSOPT_TO_IE)
1990               {
1991                 // Create a GOT entry for the tp-relative offset.
1992                 Output_data_got<32, false>* got
1993                     = target->got_section(symtab, layout);
1994                 got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
1995                                          target->rel_dyn_section(layout),
1996                                          elfcpp::R_386_TLS_TPOFF);
1997               }
1998             else if (optimized_type != tls::TLSOPT_TO_LE)
1999               unsupported_reloc_global(object, r_type, gsym);
2000             break;
2001
2002           case elfcpp::R_386_TLS_DESC_CALL:
2003             break;
2004
2005           case elfcpp::R_386_TLS_LDM:         // Local-dynamic
2006             if (optimized_type == tls::TLSOPT_NONE)
2007               {
2008                 // Create a GOT entry for the module index.
2009                 target->got_mod_index_entry(symtab, layout, object);
2010               }
2011             else if (optimized_type != tls::TLSOPT_TO_LE)
2012               unsupported_reloc_global(object, r_type, gsym);
2013             break;
2014
2015           case elfcpp::R_386_TLS_LDO_32:      // Alternate local-dynamic
2016             break;
2017
2018           case elfcpp::R_386_TLS_IE:          // Initial-exec
2019           case elfcpp::R_386_TLS_IE_32:
2020           case elfcpp::R_386_TLS_GOTIE:
2021             layout->set_has_static_tls();
2022             if (optimized_type == tls::TLSOPT_NONE)
2023               {
2024                 // For the R_386_TLS_IE relocation, we need to create a
2025                 // dynamic relocation when building a shared library.
2026                 if (r_type == elfcpp::R_386_TLS_IE
2027                     && parameters->options().shared())
2028                   {
2029                     Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2030                     rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
2031                                                  output_section, object,
2032                                                  data_shndx,
2033                                                  reloc.get_r_offset());
2034                   }
2035                 // Create a GOT entry for the tp-relative offset.
2036                 Output_data_got<32, false>* got
2037                     = target->got_section(symtab, layout);
2038                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
2039                                            ? elfcpp::R_386_TLS_TPOFF32
2040                                            : elfcpp::R_386_TLS_TPOFF);
2041                 unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
2042                                          ? GOT_TYPE_TLS_OFFSET
2043                                          : GOT_TYPE_TLS_NOFFSET);
2044                 got->add_global_with_rel(gsym, got_type,
2045                                          target->rel_dyn_section(layout),
2046                                          dyn_r_type);
2047               }
2048             else if (optimized_type != tls::TLSOPT_TO_LE)
2049               unsupported_reloc_global(object, r_type, gsym);
2050             break;
2051
2052           case elfcpp::R_386_TLS_LE:          // Local-exec
2053           case elfcpp::R_386_TLS_LE_32:
2054             layout->set_has_static_tls();
2055             if (parameters->options().shared())
2056               {
2057                 // We need to create a dynamic relocation.
2058                 unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
2059                                            ? elfcpp::R_386_TLS_TPOFF32
2060                                            : elfcpp::R_386_TLS_TPOFF);
2061                 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
2062                 rel_dyn->add_global(gsym, dyn_r_type, output_section, object,
2063                                     data_shndx, reloc.get_r_offset());
2064               }
2065             break;
2066
2067           default:
2068             gold_unreachable();
2069           }
2070       }
2071       break;
2072
2073     case elfcpp::R_386_32PLT:
2074     case elfcpp::R_386_TLS_GD_32:
2075     case elfcpp::R_386_TLS_GD_PUSH:
2076     case elfcpp::R_386_TLS_GD_CALL:
2077     case elfcpp::R_386_TLS_GD_POP:
2078     case elfcpp::R_386_TLS_LDM_32:
2079     case elfcpp::R_386_TLS_LDM_PUSH:
2080     case elfcpp::R_386_TLS_LDM_CALL:
2081     case elfcpp::R_386_TLS_LDM_POP:
2082     case elfcpp::R_386_USED_BY_INTEL_200:
2083     default:
2084       unsupported_reloc_global(object, r_type, gsym);
2085       break;
2086     }
2087 }
2088
2089 // Process relocations for gc.
2090
2091 void
2092 Target_i386::gc_process_relocs(Symbol_table* symtab,
2093                                Layout* layout,
2094                                Sized_relobj_file<32, false>* object,
2095                                unsigned int data_shndx,
2096                                unsigned int,
2097                                const unsigned char* prelocs,
2098                                size_t reloc_count,
2099                                Output_section* output_section,
2100                                bool needs_special_offset_handling,
2101                                size_t local_symbol_count,
2102                                const unsigned char* plocal_symbols)
2103 {
2104   gold::gc_process_relocs<32, false, Target_i386, elfcpp::SHT_REL,
2105                           Target_i386::Scan,
2106                           Target_i386::Relocatable_size_for_reloc>(
2107     symtab,
2108     layout,
2109     this,
2110     object,
2111     data_shndx,
2112     prelocs,
2113     reloc_count,
2114     output_section,
2115     needs_special_offset_handling,
2116     local_symbol_count,
2117     plocal_symbols);
2118 }
2119
2120 // Scan relocations for a section.
2121
2122 void
2123 Target_i386::scan_relocs(Symbol_table* symtab,
2124                          Layout* layout,
2125                          Sized_relobj_file<32, false>* object,
2126                          unsigned int data_shndx,
2127                          unsigned int sh_type,
2128                          const unsigned char* prelocs,
2129                          size_t reloc_count,
2130                          Output_section* output_section,
2131                          bool needs_special_offset_handling,
2132                          size_t local_symbol_count,
2133                          const unsigned char* plocal_symbols)
2134 {
2135   if (sh_type == elfcpp::SHT_RELA)
2136     {
2137       gold_error(_("%s: unsupported RELA reloc section"),
2138                  object->name().c_str());
2139       return;
2140     }
2141
2142   gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL,
2143                     Target_i386::Scan>(
2144     symtab,
2145     layout,
2146     this,
2147     object,
2148     data_shndx,
2149     prelocs,
2150     reloc_count,
2151     output_section,
2152     needs_special_offset_handling,
2153     local_symbol_count,
2154     plocal_symbols);
2155 }
2156
2157 // Finalize the sections.
2158
2159 void
2160 Target_i386::do_finalize_sections(
2161     Layout* layout,
2162     const Input_objects*,
2163     Symbol_table* symtab)
2164 {
2165   const Reloc_section* rel_plt = (this->plt_ == NULL
2166                                   ? NULL
2167                                   : this->plt_->rel_plt());
2168   layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
2169                                   this->rel_dyn_, true, false);
2170
2171   // Emit any relocs we saved in an attempt to avoid generating COPY
2172   // relocs.
2173   if (this->copy_relocs_.any_saved_relocs())
2174     this->copy_relocs_.emit(this->rel_dyn_section(layout));
2175
2176   // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
2177   // the .got.plt section.
2178   Symbol* sym = this->global_offset_table_;
2179   if (sym != NULL)
2180     {
2181       uint32_t data_size = this->got_plt_->current_data_size();
2182       symtab->get_sized_symbol<32>(sym)->set_symsize(data_size);
2183     }
2184
2185   if (parameters->doing_static_link() && this->plt_ == NULL)
2186     {
2187       // If linking statically, make sure that the __rel_iplt symbols
2188       // were defined if necessary, even if we didn't create a PLT.
2189       static const Define_symbol_in_segment syms[] =
2190         {
2191           {
2192             "__rel_iplt_start",         // name
2193             elfcpp::PT_LOAD,            // segment_type
2194             elfcpp::PF_W,               // segment_flags_set
2195             elfcpp::PF(0),              // segment_flags_clear
2196             0,                          // value
2197             0,                          // size
2198             elfcpp::STT_NOTYPE,         // type
2199             elfcpp::STB_GLOBAL,         // binding
2200             elfcpp::STV_HIDDEN,         // visibility
2201             0,                          // nonvis
2202             Symbol::SEGMENT_START,      // offset_from_base
2203             true                        // only_if_ref
2204           },
2205           {
2206             "__rel_iplt_end",           // name
2207             elfcpp::PT_LOAD,            // segment_type
2208             elfcpp::PF_W,               // segment_flags_set
2209             elfcpp::PF(0),              // segment_flags_clear
2210             0,                          // value
2211             0,                          // size
2212             elfcpp::STT_NOTYPE,         // type
2213             elfcpp::STB_GLOBAL,         // binding
2214             elfcpp::STV_HIDDEN,         // visibility
2215             0,                          // nonvis
2216             Symbol::SEGMENT_START,      // offset_from_base
2217             true                        // only_if_ref
2218           }
2219         };
2220
2221       symtab->define_symbols(layout, 2, syms,
2222                              layout->script_options()->saw_sections_clause());
2223     }
2224 }
2225
2226 // Return whether a direct absolute static relocation needs to be applied.
2227 // In cases where Scan::local() or Scan::global() has created
2228 // a dynamic relocation other than R_386_RELATIVE, the addend
2229 // of the relocation is carried in the data, and we must not
2230 // apply the static relocation.
2231
2232 inline bool
2233 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol<32>* gsym,
2234                                                  unsigned int r_type,
2235                                                  bool is_32bit,
2236                                                  Output_section* output_section)
2237 {
2238   // If the output section is not allocated, then we didn't call
2239   // scan_relocs, we didn't create a dynamic reloc, and we must apply
2240   // the reloc here.
2241   if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
2242     return true;
2243
2244   int ref_flags = Scan::get_reference_flags(r_type);
2245
2246   // For local symbols, we will have created a non-RELATIVE dynamic
2247   // relocation only if (a) the output is position independent,
2248   // (b) the relocation is absolute (not pc- or segment-relative), and
2249   // (c) the relocation is not 32 bits wide.
2250   if (gsym == NULL)
2251     return !(parameters->options().output_is_position_independent()
2252              && (ref_flags & Symbol::ABSOLUTE_REF)
2253              && !is_32bit);
2254
2255   // For global symbols, we use the same helper routines used in the
2256   // scan pass.  If we did not create a dynamic relocation, or if we
2257   // created a RELATIVE dynamic relocation, we should apply the static
2258   // relocation.
2259   bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
2260   bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
2261                 && gsym->can_use_relative_reloc(ref_flags
2262                                                 & Symbol::FUNCTION_CALL);
2263   return !has_dyn || is_rel;
2264 }
2265
2266 // Perform a relocation.
2267
2268 inline bool
2269 Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
2270                                 Target_i386* target,
2271                                 Output_section* output_section,
2272                                 size_t relnum,
2273                                 const elfcpp::Rel<32, false>& rel,
2274                                 unsigned int r_type,
2275                                 const Sized_symbol<32>* gsym,
2276                                 const Symbol_value<32>* psymval,
2277                                 unsigned char* view,
2278                                 elfcpp::Elf_types<32>::Elf_Addr address,
2279                                 section_size_type view_size)
2280 {
2281   if (this->skip_call_tls_get_addr_)
2282     {
2283       if ((r_type != elfcpp::R_386_PLT32
2284            && r_type != elfcpp::R_386_PC32)
2285           || gsym == NULL
2286           || strcmp(gsym->name(), "___tls_get_addr") != 0)
2287         gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2288                                _("missing expected TLS relocation"));
2289       else
2290         {
2291           this->skip_call_tls_get_addr_ = false;
2292           return false;
2293         }
2294     }
2295
2296   const Sized_relobj_file<32, false>* object = relinfo->object;
2297
2298   // Pick the value to use for symbols defined in shared objects.
2299   Symbol_value<32> symval;
2300   if (gsym != NULL
2301       && gsym->type() == elfcpp::STT_GNU_IFUNC
2302       && r_type == elfcpp::R_386_32
2303       && gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type))
2304       && gsym->can_use_relative_reloc(false)
2305       && !gsym->is_from_dynobj()
2306       && !gsym->is_undefined()
2307       && !gsym->is_preemptible())
2308     {
2309       // In this case we are generating a R_386_IRELATIVE reloc.  We
2310       // want to use the real value of the symbol, not the PLT offset.
2311     }
2312   else if (gsym != NULL
2313            && gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
2314     {
2315       symval.set_output_value(target->plt_section()->address()
2316                               + gsym->plt_offset());
2317       psymval = &symval;
2318     }
2319   else if (gsym == NULL && psymval->is_ifunc_symbol())
2320     {
2321       unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2322       if (object->local_has_plt_offset(r_sym))
2323         {
2324           symval.set_output_value(target->plt_section()->address()
2325                                   + object->local_plt_offset(r_sym));
2326           psymval = &symval;
2327         }
2328     }
2329
2330   // Get the GOT offset if needed.
2331   // The GOT pointer points to the end of the GOT section.
2332   // We need to subtract the size of the GOT section to get
2333   // the actual offset to use in the relocation.
2334   bool have_got_offset = false;
2335   unsigned int got_offset = 0;
2336   switch (r_type)
2337     {
2338     case elfcpp::R_386_GOT32:
2339       if (gsym != NULL)
2340         {
2341           gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
2342           got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
2343                         - target->got_size());
2344         }
2345       else
2346         {
2347           unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2348           gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
2349           got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
2350                         - target->got_size());
2351         }
2352       have_got_offset = true;
2353       break;
2354
2355     default:
2356       break;
2357     }
2358
2359   switch (r_type)
2360     {
2361     case elfcpp::R_386_NONE:
2362     case elfcpp::R_386_GNU_VTINHERIT:
2363     case elfcpp::R_386_GNU_VTENTRY:
2364       break;
2365
2366     case elfcpp::R_386_32:
2367       if (should_apply_static_reloc(gsym, r_type, true, output_section))
2368         Relocate_functions<32, false>::rel32(view, object, psymval);
2369       break;
2370
2371     case elfcpp::R_386_PC32:
2372       if (should_apply_static_reloc(gsym, r_type, true, output_section))
2373         Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
2374       break;
2375
2376     case elfcpp::R_386_16:
2377       if (should_apply_static_reloc(gsym, r_type, false, output_section))
2378         Relocate_functions<32, false>::rel16(view, object, psymval);
2379       break;
2380
2381     case elfcpp::R_386_PC16:
2382       if (should_apply_static_reloc(gsym, r_type, false, output_section))
2383         Relocate_functions<32, false>::pcrel16(view, object, psymval, address);
2384       break;
2385
2386     case elfcpp::R_386_8:
2387       if (should_apply_static_reloc(gsym, r_type, false, output_section))
2388         Relocate_functions<32, false>::rel8(view, object, psymval);
2389       break;
2390
2391     case elfcpp::R_386_PC8:
2392       if (should_apply_static_reloc(gsym, r_type, false, output_section))
2393         Relocate_functions<32, false>::pcrel8(view, object, psymval, address);
2394       break;
2395
2396     case elfcpp::R_386_PLT32:
2397       gold_assert(gsym == NULL
2398                   || gsym->has_plt_offset()
2399                   || gsym->final_value_is_known()
2400                   || (gsym->is_defined()
2401                       && !gsym->is_from_dynobj()
2402                       && !gsym->is_preemptible()));
2403       Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
2404       break;
2405
2406     case elfcpp::R_386_GOT32:
2407       gold_assert(have_got_offset);
2408       Relocate_functions<32, false>::rel32(view, got_offset);
2409       break;
2410
2411     case elfcpp::R_386_GOTOFF:
2412       {
2413         elfcpp::Elf_types<32>::Elf_Addr value;
2414         value = (psymval->value(object, 0)
2415                  - target->got_plt_section()->address());
2416         Relocate_functions<32, false>::rel32(view, value);
2417       }
2418       break;
2419
2420     case elfcpp::R_386_GOTPC:
2421       {
2422         elfcpp::Elf_types<32>::Elf_Addr value;
2423         value = target->got_plt_section()->address();
2424         Relocate_functions<32, false>::pcrel32(view, value, address);
2425       }
2426       break;
2427
2428     case elfcpp::R_386_COPY:
2429     case elfcpp::R_386_GLOB_DAT:
2430     case elfcpp::R_386_JUMP_SLOT:
2431     case elfcpp::R_386_RELATIVE:
2432     case elfcpp::R_386_IRELATIVE:
2433       // These are outstanding tls relocs, which are unexpected when
2434       // linking.
2435     case elfcpp::R_386_TLS_TPOFF:
2436     case elfcpp::R_386_TLS_DTPMOD32:
2437     case elfcpp::R_386_TLS_DTPOFF32:
2438     case elfcpp::R_386_TLS_TPOFF32:
2439     case elfcpp::R_386_TLS_DESC:
2440       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2441                              _("unexpected reloc %u in object file"),
2442                              r_type);
2443       break;
2444
2445       // These are initial tls relocs, which are expected when
2446       // linking.
2447     case elfcpp::R_386_TLS_GD:             // Global-dynamic
2448     case elfcpp::R_386_TLS_GOTDESC:        // Global-dynamic (from ~oliva url)
2449     case elfcpp::R_386_TLS_DESC_CALL:
2450     case elfcpp::R_386_TLS_LDM:            // Local-dynamic
2451     case elfcpp::R_386_TLS_LDO_32:         // Alternate local-dynamic
2452     case elfcpp::R_386_TLS_IE:             // Initial-exec
2453     case elfcpp::R_386_TLS_IE_32:
2454     case elfcpp::R_386_TLS_GOTIE:
2455     case elfcpp::R_386_TLS_LE:             // Local-exec
2456     case elfcpp::R_386_TLS_LE_32:
2457       this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
2458                          view, address, view_size);
2459       break;
2460
2461     case elfcpp::R_386_32PLT:
2462     case elfcpp::R_386_TLS_GD_32:
2463     case elfcpp::R_386_TLS_GD_PUSH:
2464     case elfcpp::R_386_TLS_GD_CALL:
2465     case elfcpp::R_386_TLS_GD_POP:
2466     case elfcpp::R_386_TLS_LDM_32:
2467     case elfcpp::R_386_TLS_LDM_PUSH:
2468     case elfcpp::R_386_TLS_LDM_CALL:
2469     case elfcpp::R_386_TLS_LDM_POP:
2470     case elfcpp::R_386_USED_BY_INTEL_200:
2471     default:
2472       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2473                              _("unsupported reloc %u"),
2474                              r_type);
2475       break;
2476     }
2477
2478   return true;
2479 }
2480
2481 // Perform a TLS relocation.
2482
2483 inline void
2484 Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo,
2485                                     Target_i386* target,
2486                                     size_t relnum,
2487                                     const elfcpp::Rel<32, false>& rel,
2488                                     unsigned int r_type,
2489                                     const Sized_symbol<32>* gsym,
2490                                     const Symbol_value<32>* psymval,
2491                                     unsigned char* view,
2492                                     elfcpp::Elf_types<32>::Elf_Addr,
2493                                     section_size_type view_size)
2494 {
2495   Output_segment* tls_segment = relinfo->layout->tls_segment();
2496
2497   const Sized_relobj_file<32, false>* object = relinfo->object;
2498
2499   elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
2500
2501   const bool is_final = (gsym == NULL
2502                          ? !parameters->options().shared()
2503                          : gsym->final_value_is_known());
2504   const tls::Tls_optimization optimized_type
2505       = Target_i386::optimize_tls_reloc(is_final, r_type);
2506   switch (r_type)
2507     {
2508     case elfcpp::R_386_TLS_GD:           // Global-dynamic
2509       if (optimized_type == tls::TLSOPT_TO_LE)
2510         {
2511           gold_assert(tls_segment != NULL);
2512           this->tls_gd_to_le(relinfo, relnum, tls_segment,
2513                              rel, r_type, value, view,
2514                              view_size);
2515           break;
2516         }
2517       else
2518         {
2519           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
2520                                    ? GOT_TYPE_TLS_NOFFSET
2521                                    : GOT_TYPE_TLS_PAIR);
2522           unsigned int got_offset;
2523           if (gsym != NULL)
2524             {
2525               gold_assert(gsym->has_got_offset(got_type));
2526               got_offset = gsym->got_offset(got_type) - target->got_size();
2527             }
2528           else
2529             {
2530               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2531               gold_assert(object->local_has_got_offset(r_sym, got_type));
2532               got_offset = (object->local_got_offset(r_sym, got_type)
2533                             - target->got_size());
2534             }
2535           if (optimized_type == tls::TLSOPT_TO_IE)
2536             {
2537               gold_assert(tls_segment != NULL);
2538               this->tls_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
2539                                  got_offset, view, view_size);
2540               break;
2541             }
2542           else if (optimized_type == tls::TLSOPT_NONE)
2543             {
2544               // Relocate the field with the offset of the pair of GOT
2545               // entries.
2546               Relocate_functions<32, false>::rel32(view, got_offset);
2547               break;
2548             }
2549         }
2550       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2551                              _("unsupported reloc %u"),
2552                              r_type);
2553       break;
2554
2555     case elfcpp::R_386_TLS_GOTDESC:      // Global-dynamic (from ~oliva url)
2556     case elfcpp::R_386_TLS_DESC_CALL:
2557       this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
2558       if (optimized_type == tls::TLSOPT_TO_LE)
2559         {
2560           gold_assert(tls_segment != NULL);
2561           this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
2562                                   rel, r_type, value, view,
2563                                   view_size);
2564           break;
2565         }
2566       else
2567         {
2568           unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
2569                                    ? GOT_TYPE_TLS_NOFFSET
2570                                    : GOT_TYPE_TLS_DESC);
2571           unsigned int got_offset = 0;
2572           if (r_type == elfcpp::R_386_TLS_GOTDESC
2573               && optimized_type == tls::TLSOPT_NONE)
2574             {
2575               // We created GOT entries in the .got.tlsdesc portion of
2576               // the .got.plt section, but the offset stored in the
2577               // symbol is the offset within .got.tlsdesc.
2578               got_offset = (target->got_size()
2579                             + target->got_plt_section()->data_size());
2580             }
2581           if (gsym != NULL)
2582             {
2583               gold_assert(gsym->has_got_offset(got_type));
2584               got_offset += gsym->got_offset(got_type) - target->got_size();
2585             }
2586           else
2587             {
2588               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2589               gold_assert(object->local_has_got_offset(r_sym, got_type));
2590               got_offset += (object->local_got_offset(r_sym, got_type)
2591                              - target->got_size());
2592             }
2593           if (optimized_type == tls::TLSOPT_TO_IE)
2594             {
2595               gold_assert(tls_segment != NULL);
2596               this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
2597                                       got_offset, view, view_size);
2598               break;
2599             }
2600           else if (optimized_type == tls::TLSOPT_NONE)
2601             {
2602               if (r_type == elfcpp::R_386_TLS_GOTDESC)
2603                 {
2604                   // Relocate the field with the offset of the pair of GOT
2605                   // entries.
2606                   Relocate_functions<32, false>::rel32(view, got_offset);
2607                 }
2608               break;
2609             }
2610         }
2611       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2612                              _("unsupported reloc %u"),
2613                              r_type);
2614       break;
2615
2616     case elfcpp::R_386_TLS_LDM:          // Local-dynamic
2617       if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN)
2618         {
2619           gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2620                                  _("both SUN and GNU model "
2621                                    "TLS relocations"));
2622           break;
2623         }
2624       this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
2625       if (optimized_type == tls::TLSOPT_TO_LE)
2626         {
2627           gold_assert(tls_segment != NULL);
2628           this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, r_type,
2629                              value, view, view_size);
2630           break;
2631         }
2632       else if (optimized_type == tls::TLSOPT_NONE)
2633         {
2634           // Relocate the field with the offset of the GOT entry for
2635           // the module index.
2636           unsigned int got_offset;
2637           got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
2638                         - target->got_size());
2639           Relocate_functions<32, false>::rel32(view, got_offset);
2640           break;
2641         }
2642       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2643                              _("unsupported reloc %u"),
2644                              r_type);
2645       break;
2646
2647     case elfcpp::R_386_TLS_LDO_32:       // Alternate local-dynamic
2648       if (optimized_type == tls::TLSOPT_TO_LE)
2649         {
2650           // This reloc can appear in debugging sections, in which
2651           // case we must not convert to local-exec.  We decide what
2652           // to do based on whether the section is marked as
2653           // containing executable code.  That is what the GNU linker
2654           // does as well.
2655           elfcpp::Shdr<32, false> shdr(relinfo->data_shdr);
2656           if ((shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0)
2657             {
2658               gold_assert(tls_segment != NULL);
2659               value -= tls_segment->memsz();
2660             }
2661         }
2662       Relocate_functions<32, false>::rel32(view, value);
2663       break;
2664
2665     case elfcpp::R_386_TLS_IE:           // Initial-exec
2666     case elfcpp::R_386_TLS_GOTIE:
2667     case elfcpp::R_386_TLS_IE_32:
2668       if (optimized_type == tls::TLSOPT_TO_LE)
2669         {
2670           gold_assert(tls_segment != NULL);
2671           Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
2672                                               rel, r_type, value, view,
2673                                               view_size);
2674           break;
2675         }
2676       else if (optimized_type == tls::TLSOPT_NONE)
2677         {
2678           // Relocate the field with the offset of the GOT entry for
2679           // the tp-relative offset of the symbol.
2680           unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
2681                                    ? GOT_TYPE_TLS_OFFSET
2682                                    : GOT_TYPE_TLS_NOFFSET);
2683           unsigned int got_offset;
2684           if (gsym != NULL)
2685             {
2686               gold_assert(gsym->has_got_offset(got_type));
2687               got_offset = gsym->got_offset(got_type);
2688             }
2689           else
2690             {
2691               unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
2692               gold_assert(object->local_has_got_offset(r_sym, got_type));
2693               got_offset = object->local_got_offset(r_sym, got_type);
2694             }
2695           // For the R_386_TLS_IE relocation, we need to apply the
2696           // absolute address of the GOT entry.
2697           if (r_type == elfcpp::R_386_TLS_IE)
2698             got_offset += target->got_plt_section()->address();
2699           // All GOT offsets are relative to the end of the GOT.
2700           got_offset -= target->got_size();
2701           Relocate_functions<32, false>::rel32(view, got_offset);
2702           break;
2703         }
2704       gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
2705                              _("unsupported reloc %u"),
2706                              r_type);
2707       break;
2708
2709     case elfcpp::R_386_TLS_LE:           // Local-exec
2710       // If we're creating a shared library, a dynamic relocation will
2711       // have been created for this location, so do not apply it now.
2712       if (!parameters->options().shared())
2713         {
2714           gold_assert(tls_segment != NULL);
2715           value -= tls_segment->memsz();
2716           Relocate_functions<32, false>::rel32(view, value);
2717         }
2718       break;
2719
2720     case elfcpp::R_386_TLS_LE_32:
2721       // If we're creating a shared library, a dynamic relocation will
2722       // have been created for this location, so do not apply it now.
2723       if (!parameters->options().shared())
2724         {
2725           gold_assert(tls_segment != NULL);
2726           value = tls_segment->memsz() - value;
2727           Relocate_functions<32, false>::rel32(view, value);
2728         }
2729       break;
2730     }
2731 }
2732
2733 // Do a relocation in which we convert a TLS General-Dynamic to a
2734 // Local-Exec.
2735
2736 inline void
2737 Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo,
2738                                     size_t relnum,
2739                                     Output_segment* tls_segment,
2740                                     const elfcpp::Rel<32, false>& rel,
2741                                     unsigned int,
2742                                     elfcpp::Elf_types<32>::Elf_Addr value,
2743                                     unsigned char* view,
2744                                     section_size_type view_size)
2745 {
2746   // leal foo(,%reg,1),%eax; call ___tls_get_addr
2747   //  ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2748   // leal foo(%reg),%eax; call ___tls_get_addr
2749   //  ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
2750
2751   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2752   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2753
2754   unsigned char op1 = view[-1];
2755   unsigned char op2 = view[-2];
2756
2757   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2758                  op2 == 0x8d || op2 == 0x04);
2759   tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2760
2761   int roff = 5;
2762
2763   if (op2 == 0x04)
2764     {
2765       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
2766       tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
2767       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2768                      ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
2769       memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2770     }
2771   else
2772     {
2773       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2774                      (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
2775       if (rel.get_r_offset() + 9 < view_size
2776           && view[9] == 0x90)
2777         {
2778           // There is a trailing nop.  Use the size byte subl.
2779           memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2780           roff = 6;
2781         }
2782       else
2783         {
2784           // Use the five byte subl.
2785           memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2786         }
2787     }
2788
2789   value = tls_segment->memsz() - value;
2790   Relocate_functions<32, false>::rel32(view + roff, value);
2791
2792   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2793   // We can skip it.
2794   this->skip_call_tls_get_addr_ = true;
2795 }
2796
2797 // Do a relocation in which we convert a TLS General-Dynamic to an
2798 // Initial-Exec.
2799
2800 inline void
2801 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info<32, false>* relinfo,
2802                                     size_t relnum,
2803                                     Output_segment*,
2804                                     const elfcpp::Rel<32, false>& rel,
2805                                     unsigned int,
2806                                     elfcpp::Elf_types<32>::Elf_Addr value,
2807                                     unsigned char* view,
2808                                     section_size_type view_size)
2809 {
2810   // leal foo(,%ebx,1),%eax; call ___tls_get_addr
2811   //  ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
2812
2813   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2814   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2815
2816   unsigned char op1 = view[-1];
2817   unsigned char op2 = view[-2];
2818
2819   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2820                  op2 == 0x8d || op2 == 0x04);
2821   tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2822
2823   int roff = 5;
2824
2825   // FIXME: For now, support only the first (SIB) form.
2826   tls::check_tls(relinfo, relnum, rel.get_r_offset(), op2 == 0x04);
2827
2828   if (op2 == 0x04)
2829     {
2830       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
2831       tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
2832       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2833                      ((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
2834       memcpy(view - 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
2835     }
2836   else
2837     {
2838       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2839                      (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
2840       if (rel.get_r_offset() + 9 < view_size
2841           && view[9] == 0x90)
2842         {
2843           // FIXME: This is not the right instruction sequence.
2844           // There is a trailing nop.  Use the size byte subl.
2845           memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
2846           roff = 6;
2847         }
2848       else
2849         {
2850           // FIXME: This is not the right instruction sequence.
2851           // Use the five byte subl.
2852           memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
2853         }
2854     }
2855
2856   Relocate_functions<32, false>::rel32(view + roff, value);
2857
2858   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2859   // We can skip it.
2860   this->skip_call_tls_get_addr_ = true;
2861 }
2862
2863 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2864 // General-Dynamic to a Local-Exec.
2865
2866 inline void
2867 Target_i386::Relocate::tls_desc_gd_to_le(
2868     const Relocate_info<32, false>* relinfo,
2869     size_t relnum,
2870     Output_segment* tls_segment,
2871     const elfcpp::Rel<32, false>& rel,
2872     unsigned int r_type,
2873     elfcpp::Elf_types<32>::Elf_Addr value,
2874     unsigned char* view,
2875     section_size_type view_size)
2876 {
2877   if (r_type == elfcpp::R_386_TLS_GOTDESC)
2878     {
2879       // leal foo@TLSDESC(%ebx), %eax
2880       // ==> leal foo@NTPOFF, %eax
2881       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2882       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2883       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2884                      view[-2] == 0x8d && view[-1] == 0x83);
2885       view[-1] = 0x05;
2886       value -= tls_segment->memsz();
2887       Relocate_functions<32, false>::rel32(view, value);
2888     }
2889   else
2890     {
2891       // call *foo@TLSCALL(%eax)
2892       // ==> nop; nop
2893       gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
2894       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
2895       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2896                      view[0] == 0xff && view[1] == 0x10);
2897       view[0] = 0x66;
2898       view[1] = 0x90;
2899     }
2900 }
2901
2902 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
2903 // General-Dynamic to an Initial-Exec.
2904
2905 inline void
2906 Target_i386::Relocate::tls_desc_gd_to_ie(
2907     const Relocate_info<32, false>* relinfo,
2908     size_t relnum,
2909     Output_segment*,
2910     const elfcpp::Rel<32, false>& rel,
2911     unsigned int r_type,
2912     elfcpp::Elf_types<32>::Elf_Addr value,
2913     unsigned char* view,
2914     section_size_type view_size)
2915 {
2916   if (r_type == elfcpp::R_386_TLS_GOTDESC)
2917     {
2918       // leal foo@TLSDESC(%ebx), %eax
2919       // ==> movl foo@GOTNTPOFF(%ebx), %eax
2920       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2921       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2922       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2923                      view[-2] == 0x8d && view[-1] == 0x83);
2924       view[-2] = 0x8b;
2925       Relocate_functions<32, false>::rel32(view, value);
2926     }
2927   else
2928     {
2929       // call *foo@TLSCALL(%eax)
2930       // ==> nop; nop
2931       gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
2932       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
2933       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2934                      view[0] == 0xff && view[1] == 0x10);
2935       view[0] = 0x66;
2936       view[1] = 0x90;
2937     }
2938 }
2939
2940 // Do a relocation in which we convert a TLS Local-Dynamic to a
2941 // Local-Exec.
2942
2943 inline void
2944 Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo,
2945                                     size_t relnum,
2946                                     Output_segment*,
2947                                     const elfcpp::Rel<32, false>& rel,
2948                                     unsigned int,
2949                                     elfcpp::Elf_types<32>::Elf_Addr,
2950                                     unsigned char* view,
2951                                     section_size_type view_size)
2952 {
2953   // leal foo(%reg), %eax; call ___tls_get_addr
2954   // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
2955
2956   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
2957   tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
2958
2959   // FIXME: Does this test really always pass?
2960   tls::check_tls(relinfo, relnum, rel.get_r_offset(),
2961                  view[-2] == 0x8d && view[-1] == 0x83);
2962
2963   tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
2964
2965   memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
2966
2967   // The next reloc should be a PLT32 reloc against __tls_get_addr.
2968   // We can skip it.
2969   this->skip_call_tls_get_addr_ = true;
2970 }
2971
2972 // Do a relocation in which we convert a TLS Initial-Exec to a
2973 // Local-Exec.
2974
2975 inline void
2976 Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo,
2977                                     size_t relnum,
2978                                     Output_segment* tls_segment,
2979                                     const elfcpp::Rel<32, false>& rel,
2980                                     unsigned int r_type,
2981                                     elfcpp::Elf_types<32>::Elf_Addr value,
2982                                     unsigned char* view,
2983                                     section_size_type view_size)
2984 {
2985   // We have to actually change the instructions, which means that we
2986   // need to examine the opcodes to figure out which instruction we
2987   // are looking at.
2988   if (r_type == elfcpp::R_386_TLS_IE)
2989     {
2990       // movl %gs:XX,%eax  ==>  movl $YY,%eax
2991       // movl %gs:XX,%reg  ==>  movl $YY,%reg
2992       // addl %gs:XX,%reg  ==>  addl $YY,%reg
2993       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -1);
2994       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
2995
2996       unsigned char op1 = view[-1];
2997       if (op1 == 0xa1)
2998         {
2999           // movl XX,%eax  ==>  movl $YY,%eax
3000           view[-1] = 0xb8;
3001         }
3002       else
3003         {
3004           tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3005
3006           unsigned char op2 = view[-2];
3007           if (op2 == 0x8b)
3008             {
3009               // movl XX,%reg  ==>  movl $YY,%reg
3010               tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3011                              (op1 & 0xc7) == 0x05);
3012               view[-2] = 0xc7;
3013               view[-1] = 0xc0 | ((op1 >> 3) & 7);
3014             }
3015           else if (op2 == 0x03)
3016             {
3017               // addl XX,%reg  ==>  addl $YY,%reg
3018               tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3019                              (op1 & 0xc7) == 0x05);
3020               view[-2] = 0x81;
3021               view[-1] = 0xc0 | ((op1 >> 3) & 7);
3022             }
3023           else
3024             tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
3025         }
3026     }
3027   else
3028     {
3029       // subl %gs:XX(%reg1),%reg2  ==>  subl $YY,%reg2
3030       // movl %gs:XX(%reg1),%reg2  ==>  movl $YY,%reg2
3031       // addl %gs:XX(%reg1),%reg2  ==>  addl $YY,$reg2
3032       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
3033       tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
3034
3035       unsigned char op1 = view[-1];
3036       unsigned char op2 = view[-2];
3037       tls::check_tls(relinfo, relnum, rel.get_r_offset(),
3038                      (op1 & 0xc0) == 0x80 && (op1 & 7) != 4);
3039       if (op2 == 0x8b)
3040         {
3041           // movl %gs:XX(%reg1),%reg2  ==>  movl $YY,%reg2
3042           view[-2] = 0xc7;
3043           view[-1] = 0xc0 | ((op1 >> 3) & 7);
3044         }
3045       else if (op2 == 0x2b)
3046         {
3047           // subl %gs:XX(%reg1),%reg2  ==>  subl $YY,%reg2
3048           view[-2] = 0x81;
3049           view[-1] = 0xe8 | ((op1 >> 3) & 7);
3050         }
3051       else if (op2 == 0x03)
3052         {
3053           // addl %gs:XX(%reg1),%reg2  ==>  addl $YY,$reg2
3054           view[-2] = 0x81;
3055           view[-1] = 0xc0 | ((op1 >> 3) & 7);
3056         }
3057       else
3058         tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
3059     }
3060
3061   value = tls_segment->memsz() - value;
3062   if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE)
3063     value = - value;
3064
3065   Relocate_functions<32, false>::rel32(view, value);
3066 }
3067
3068 // Relocate section data.
3069
3070 void
3071 Target_i386::relocate_section(const Relocate_info<32, false>* relinfo,
3072                               unsigned int sh_type,
3073                               const unsigned char* prelocs,
3074                               size_t reloc_count,
3075                               Output_section* output_section,
3076                               bool needs_special_offset_handling,
3077                               unsigned char* view,
3078                               elfcpp::Elf_types<32>::Elf_Addr address,
3079                               section_size_type view_size,
3080                               const Reloc_symbol_changes* reloc_symbol_changes)
3081 {
3082   gold_assert(sh_type == elfcpp::SHT_REL);
3083
3084   gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL,
3085                          Target_i386::Relocate>(
3086     relinfo,
3087     this,
3088     prelocs,
3089     reloc_count,
3090     output_section,
3091     needs_special_offset_handling,
3092     view,
3093     address,
3094     view_size,
3095     reloc_symbol_changes);
3096 }
3097
3098 // Return the size of a relocation while scanning during a relocatable
3099 // link.
3100
3101 unsigned int
3102 Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
3103     unsigned int r_type,
3104     Relobj* object)
3105 {
3106   switch (r_type)
3107     {
3108     case elfcpp::R_386_NONE:
3109     case elfcpp::R_386_GNU_VTINHERIT:
3110     case elfcpp::R_386_GNU_VTENTRY:
3111     case elfcpp::R_386_TLS_GD:            // Global-dynamic
3112     case elfcpp::R_386_TLS_GOTDESC:       // Global-dynamic (from ~oliva url)
3113     case elfcpp::R_386_TLS_DESC_CALL:
3114     case elfcpp::R_386_TLS_LDM:           // Local-dynamic
3115     case elfcpp::R_386_TLS_LDO_32:        // Alternate local-dynamic
3116     case elfcpp::R_386_TLS_IE:            // Initial-exec
3117     case elfcpp::R_386_TLS_IE_32:
3118     case elfcpp::R_386_TLS_GOTIE:
3119     case elfcpp::R_386_TLS_LE:            // Local-exec
3120     case elfcpp::R_386_TLS_LE_32:
3121       return 0;
3122
3123     case elfcpp::R_386_32:
3124     case elfcpp::R_386_PC32:
3125     case elfcpp::R_386_GOT32:
3126     case elfcpp::R_386_PLT32:
3127     case elfcpp::R_386_GOTOFF:
3128     case elfcpp::R_386_GOTPC:
3129      return 4;
3130
3131     case elfcpp::R_386_16:
3132     case elfcpp::R_386_PC16:
3133       return 2;
3134
3135     case elfcpp::R_386_8:
3136     case elfcpp::R_386_PC8:
3137       return 1;
3138
3139       // These are relocations which should only be seen by the
3140       // dynamic linker, and should never be seen here.
3141     case elfcpp::R_386_COPY:
3142     case elfcpp::R_386_GLOB_DAT:
3143     case elfcpp::R_386_JUMP_SLOT:
3144     case elfcpp::R_386_RELATIVE:
3145     case elfcpp::R_386_IRELATIVE:
3146     case elfcpp::R_386_TLS_TPOFF:
3147     case elfcpp::R_386_TLS_DTPMOD32:
3148     case elfcpp::R_386_TLS_DTPOFF32:
3149     case elfcpp::R_386_TLS_TPOFF32:
3150     case elfcpp::R_386_TLS_DESC:
3151       object->error(_("unexpected reloc %u in object file"), r_type);
3152       return 0;
3153
3154     case elfcpp::R_386_32PLT:
3155     case elfcpp::R_386_TLS_GD_32:
3156     case elfcpp::R_386_TLS_GD_PUSH:
3157     case elfcpp::R_386_TLS_GD_CALL:
3158     case elfcpp::R_386_TLS_GD_POP:
3159     case elfcpp::R_386_TLS_LDM_32:
3160     case elfcpp::R_386_TLS_LDM_PUSH:
3161     case elfcpp::R_386_TLS_LDM_CALL:
3162     case elfcpp::R_386_TLS_LDM_POP:
3163     case elfcpp::R_386_USED_BY_INTEL_200:
3164     default:
3165       object->error(_("unsupported reloc %u in object file"), r_type);
3166       return 0;
3167     }
3168 }
3169
3170 // Scan the relocs during a relocatable link.
3171
3172 void
3173 Target_i386::scan_relocatable_relocs(Symbol_table* symtab,
3174                                      Layout* layout,
3175                                      Sized_relobj_file<32, false>* object,
3176                                      unsigned int data_shndx,
3177                                      unsigned int sh_type,
3178                                      const unsigned char* prelocs,
3179                                      size_t reloc_count,
3180                                      Output_section* output_section,
3181                                      bool needs_special_offset_handling,
3182                                      size_t local_symbol_count,
3183                                      const unsigned char* plocal_symbols,
3184                                      Relocatable_relocs* rr)
3185 {
3186   gold_assert(sh_type == elfcpp::SHT_REL);
3187
3188   typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_REL,
3189     Relocatable_size_for_reloc> Scan_relocatable_relocs;
3190
3191   gold::scan_relocatable_relocs<32, false, elfcpp::SHT_REL,
3192       Scan_relocatable_relocs>(
3193     symtab,
3194     layout,
3195     object,
3196     data_shndx,
3197     prelocs,
3198     reloc_count,
3199     output_section,
3200     needs_special_offset_handling,
3201     local_symbol_count,
3202     plocal_symbols,
3203     rr);
3204 }
3205
3206 // Relocate a section during a relocatable link.
3207
3208 void
3209 Target_i386::relocate_for_relocatable(
3210     const Relocate_info<32, false>* relinfo,
3211     unsigned int sh_type,
3212     const unsigned char* prelocs,
3213     size_t reloc_count,
3214     Output_section* output_section,
3215     off_t offset_in_output_section,
3216     const Relocatable_relocs* rr,
3217     unsigned char* view,
3218     elfcpp::Elf_types<32>::Elf_Addr view_address,
3219     section_size_type view_size,
3220     unsigned char* reloc_view,
3221     section_size_type reloc_view_size)
3222 {
3223   gold_assert(sh_type == elfcpp::SHT_REL);
3224
3225   gold::relocate_for_relocatable<32, false, elfcpp::SHT_REL>(
3226     relinfo,
3227     prelocs,
3228     reloc_count,
3229     output_section,
3230     offset_in_output_section,
3231     rr,
3232     view,
3233     view_address,
3234     view_size,
3235     reloc_view,
3236     reloc_view_size);
3237 }
3238
3239 // Return the value to use for a dynamic which requires special
3240 // treatment.  This is how we support equality comparisons of function
3241 // pointers across shared library boundaries, as described in the
3242 // processor specific ABI supplement.
3243
3244 uint64_t
3245 Target_i386::do_dynsym_value(const Symbol* gsym) const
3246 {
3247   gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
3248   return this->plt_section()->address() + gsym->plt_offset();
3249 }
3250
3251 // Return a string used to fill a code section with nops to take up
3252 // the specified length.
3253
3254 std::string
3255 Target_i386::do_code_fill(section_size_type length) const
3256 {
3257   if (length >= 16)
3258     {
3259       // Build a jmp instruction to skip over the bytes.
3260       unsigned char jmp[5];
3261       jmp[0] = 0xe9;
3262       elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
3263       return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
3264               + std::string(length - 5, '\0'));
3265     }
3266
3267   // Nop sequences of various lengths.
3268   const char nop1[1] = { 0x90 };                   // nop
3269   const char nop2[2] = { 0x66, 0x90 };             // xchg %ax %ax
3270   const char nop3[3] = { 0x8d, 0x76, 0x00 };       // leal 0(%esi),%esi
3271   const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00};  // leal 0(%esi,1),%esi
3272   const char nop5[5] = { 0x90, 0x8d, 0x74, 0x26,   // nop
3273                          0x00 };                   // leal 0(%esi,1),%esi
3274   const char nop6[6] = { 0x8d, 0xb6, 0x00, 0x00,   // leal 0L(%esi),%esi
3275                          0x00, 0x00 };
3276   const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00,   // leal 0L(%esi,1),%esi
3277                          0x00, 0x00, 0x00 };
3278   const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26,   // nop
3279                          0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
3280   const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc,   // movl %esi,%esi
3281                          0x27, 0x00, 0x00, 0x00,   // leal 0L(%edi,1),%edi
3282                          0x00 };
3283   const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
3284                            0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
3285                            0x00, 0x00 };
3286   const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
3287                            0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
3288                            0x00, 0x00, 0x00 };
3289   const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
3290                            0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
3291                            0x00, 0x00, 0x00, 0x00 };
3292   const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
3293                            0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
3294                            0x27, 0x00, 0x00, 0x00,
3295                            0x00 };
3296   const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
3297                            0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
3298                            0xbc, 0x27, 0x00, 0x00,
3299                            0x00, 0x00 };
3300   const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
3301                            0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
3302                            0x90, 0x90, 0x90, 0x90,
3303                            0x90, 0x90, 0x90 };
3304
3305   const char* nops[16] = {
3306     NULL,
3307     nop1, nop2, nop3, nop4, nop5, nop6, nop7,
3308     nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
3309   };
3310
3311   return std::string(nops[length], length);
3312 }
3313
3314 // Return the value to use for the base of a DW_EH_PE_datarel offset
3315 // in an FDE.  Solaris and SVR4 use DW_EH_PE_datarel because their
3316 // assembler can not write out the difference between two labels in
3317 // different sections, so instead of using a pc-relative value they
3318 // use an offset from the GOT.
3319
3320 uint64_t
3321 Target_i386::do_ehframe_datarel_base() const
3322 {
3323   gold_assert(this->global_offset_table_ != NULL);
3324   Symbol* sym = this->global_offset_table_;
3325   Sized_symbol<32>* ssym = static_cast<Sized_symbol<32>*>(sym);
3326   return ssym->value();
3327 }
3328
3329 // Return whether SYM should be treated as a call to a non-split
3330 // function.  We don't want that to be true of a call to a
3331 // get_pc_thunk function.
3332
3333 bool
3334 Target_i386::do_is_call_to_non_split(const Symbol* sym, unsigned int) const
3335 {
3336   return (sym->type() == elfcpp::STT_FUNC
3337           && !is_prefix_of("__i686.get_pc_thunk.", sym->name()));
3338 }
3339
3340 // FNOFFSET in section SHNDX in OBJECT is the start of a function
3341 // compiled with -fsplit-stack.  The function calls non-split-stack
3342 // code.  We have to change the function so that it always ensures
3343 // that it has enough stack space to run some random function.
3344
3345 void
3346 Target_i386::do_calls_non_split(Relobj* object, unsigned int shndx,
3347                                 section_offset_type fnoffset,
3348                                 section_size_type fnsize,
3349                                 unsigned char* view,
3350                                 section_size_type view_size,
3351                                 std::string* from,
3352                                 std::string* to) const
3353 {
3354   // The function starts with a comparison of the stack pointer and a
3355   // field in the TCB.  This is followed by a jump.
3356
3357   // cmp %gs:NN,%esp
3358   if (this->match_view(view, view_size, fnoffset, "\x65\x3b\x25", 3)
3359       && fnsize > 7)
3360     {
3361       // We will call __morestack if the carry flag is set after this
3362       // comparison.  We turn the comparison into an stc instruction
3363       // and some nops.
3364       view[fnoffset] = '\xf9';
3365       this->set_view_to_nop(view, view_size, fnoffset + 1, 6);
3366     }
3367   // lea NN(%esp),%ecx
3368   // lea NN(%esp),%edx
3369   else if ((this->match_view(view, view_size, fnoffset, "\x8d\x8c\x24", 3)
3370             || this->match_view(view, view_size, fnoffset, "\x8d\x94\x24", 3))
3371            && fnsize > 7)
3372     {
3373       // This is loading an offset from the stack pointer for a
3374       // comparison.  The offset is negative, so we decrease the
3375       // offset by the amount of space we need for the stack.  This
3376       // means we will avoid calling __morestack if there happens to
3377       // be plenty of space on the stack already.
3378       unsigned char* pval = view + fnoffset + 3;
3379       uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
3380       val -= parameters->options().split_stack_adjust_size();
3381       elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
3382     }
3383   else
3384     {
3385       if (!object->has_no_split_stack())
3386         object->error(_("failed to match split-stack sequence at "
3387                         "section %u offset %0zx"),
3388                       shndx, static_cast<size_t>(fnoffset));
3389       return;
3390     }
3391
3392   // We have to change the function so that it calls
3393   // __morestack_non_split instead of __morestack.  The former will
3394   // allocate additional stack space.
3395   *from = "__morestack";
3396   *to = "__morestack_non_split";
3397 }
3398
3399 // The selector for i386 object files.
3400
3401 class Target_selector_i386 : public Target_selector_freebsd
3402 {
3403 public:
3404   Target_selector_i386()
3405     : Target_selector_freebsd(elfcpp::EM_386, 32, false,
3406                               "elf32-i386", "elf32-i386-freebsd",
3407                               "elf_i386")
3408   { }
3409
3410   Target*
3411   do_instantiate_target()
3412   { return new Target_i386(); }
3413 };
3414
3415 Target_selector_i386 target_selector_i386;
3416
3417 } // End anonymous namespace.