1 // i386.cc -- i386 target support for gold.
3 // Copyright (C) 2006-2014 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
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.
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.
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.
29 #include "parameters.h"
36 #include "copy-relocs.h"
38 #include "target-reloc.h"
39 #include "target-select.h"
50 // A class to handle the PLT data.
51 // This is an abstract base class that handles most of the linker details
52 // but does not know the actual contents of PLT entries. The derived
53 // classes below fill in those details.
55 class Output_data_plt_i386
: public Output_section_data
58 typedef Output_data_reloc
<elfcpp::SHT_REL
, true, 32, false> Reloc_section
;
60 Output_data_plt_i386(Layout
*, uint64_t addralign
,
61 Output_data_space
*, Output_data_space
*);
63 // Add an entry to the PLT.
65 add_entry(Symbol_table
*, Layout
*, Symbol
* gsym
);
67 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
69 add_local_ifunc_entry(Symbol_table
*, Layout
*,
70 Sized_relobj_file
<32, false>* relobj
,
71 unsigned int local_sym_index
);
73 // Return the .rel.plt section data.
76 { return this->rel_
; }
78 // Return where the TLS_DESC relocations should go.
80 rel_tls_desc(Layout
*);
82 // Return where the IRELATIVE relocations should go.
84 rel_irelative(Symbol_table
*, Layout
*);
86 // Return whether we created a section for IRELATIVE relocations.
88 has_irelative_section() const
89 { return this->irelative_rel_
!= NULL
; }
91 // Return the number of PLT entries.
94 { return this->count_
+ this->irelative_count_
; }
96 // Return the offset of the first non-reserved PLT entry.
98 first_plt_entry_offset()
99 { return this->get_plt_entry_size(); }
101 // Return the size of a PLT entry.
103 get_plt_entry_size() const
104 { return this->do_get_plt_entry_size(); }
106 // Return the PLT address to use for a global symbol.
108 address_for_global(const Symbol
*);
110 // Return the PLT address to use for a local symbol.
112 address_for_local(const Relobj
*, unsigned int symndx
);
114 // Add .eh_frame information for the PLT.
116 add_eh_frame(Layout
* layout
)
117 { this->do_add_eh_frame(layout
); }
120 // Fill the first PLT entry, given the pointer to the PLT section data
121 // and the runtime address of the GOT.
123 fill_first_plt_entry(unsigned char* pov
,
124 elfcpp::Elf_types
<32>::Elf_Addr got_address
)
125 { this->do_fill_first_plt_entry(pov
, got_address
); }
127 // Fill a normal PLT entry, given the pointer to the entry's data in the
128 // section, the runtime address of the GOT, the offset into the GOT of
129 // the corresponding slot, the offset into the relocation section of the
130 // corresponding reloc, and the offset of this entry within the whole
131 // PLT. Return the offset from this PLT entry's runtime address that
132 // should be used to compute the initial value of the GOT slot.
134 fill_plt_entry(unsigned char* pov
,
135 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
136 unsigned int got_offset
,
137 unsigned int plt_offset
,
138 unsigned int plt_rel_offset
)
140 return this->do_fill_plt_entry(pov
, got_address
, got_offset
,
141 plt_offset
, plt_rel_offset
);
145 do_get_plt_entry_size() const = 0;
148 do_fill_first_plt_entry(unsigned char* pov
,
149 elfcpp::Elf_types
<32>::Elf_Addr got_address
) = 0;
152 do_fill_plt_entry(unsigned char* pov
,
153 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
154 unsigned int got_offset
,
155 unsigned int plt_offset
,
156 unsigned int plt_rel_offset
) = 0;
159 do_add_eh_frame(Layout
*) = 0;
162 do_adjust_output_section(Output_section
* os
);
164 // Write to a map file.
166 do_print_to_mapfile(Mapfile
* mapfile
) const
167 { mapfile
->print_output_data(this, _("** PLT")); }
169 // The .eh_frame unwind information for the PLT.
170 // The CIE is common across variants of the PLT format.
171 static const int plt_eh_frame_cie_size
= 16;
172 static const unsigned char plt_eh_frame_cie
[plt_eh_frame_cie_size
];
175 // Set the final size.
177 set_final_data_size()
179 this->set_data_size((this->count_
+ this->irelative_count_
+ 1)
180 * this->get_plt_entry_size());
183 // Write out the PLT data.
185 do_write(Output_file
*);
187 // We keep a list of global STT_GNU_IFUNC symbols, each with its
188 // offset in the GOT.
192 unsigned int got_offset
;
195 // We keep a list of local STT_GNU_IFUNC symbols, each with its
196 // offset in the GOT.
199 Sized_relobj_file
<32, false>* object
;
200 unsigned int local_sym_index
;
201 unsigned int got_offset
;
204 // A pointer to the Layout class, so that we can find the .dynamic
205 // section when we write out the GOT PLT section.
207 // The reloc section.
209 // The TLS_DESC relocations, if necessary. These must follow the
210 // regular PLT relocs.
211 Reloc_section
* tls_desc_rel_
;
212 // The IRELATIVE relocations, if necessary. These must follow the
213 // regular relocatoins and the TLS_DESC relocations.
214 Reloc_section
* irelative_rel_
;
215 // The .got.plt section.
216 Output_data_space
* got_plt_
;
217 // The part of the .got.plt section used for IRELATIVE relocs.
218 Output_data_space
* got_irelative_
;
219 // The number of PLT entries.
221 // Number of PLT entries with R_386_IRELATIVE relocs. These follow
222 // the regular PLT entries.
223 unsigned int irelative_count_
;
224 // Global STT_GNU_IFUNC symbols.
225 std::vector
<Global_ifunc
> global_ifuncs_
;
226 // Local STT_GNU_IFUNC symbols.
227 std::vector
<Local_ifunc
> local_ifuncs_
;
230 // This is an abstract class for the standard PLT layout.
231 // The derived classes below handle the actual PLT contents
232 // for the executable (non-PIC) and shared-library (PIC) cases.
233 // The unwind information is uniform across those two, so it's here.
235 class Output_data_plt_i386_standard
: public Output_data_plt_i386
238 Output_data_plt_i386_standard(Layout
* layout
,
239 Output_data_space
* got_plt
,
240 Output_data_space
* got_irelative
)
241 : Output_data_plt_i386(layout
, plt_entry_size
, got_plt
, got_irelative
)
246 do_get_plt_entry_size() const
247 { return plt_entry_size
; }
250 do_add_eh_frame(Layout
* layout
)
252 layout
->add_eh_frame_for_plt(this, plt_eh_frame_cie
, plt_eh_frame_cie_size
,
253 plt_eh_frame_fde
, plt_eh_frame_fde_size
);
256 // The size of an entry in the PLT.
257 static const int plt_entry_size
= 16;
259 // The .eh_frame unwind information for the PLT.
260 static const int plt_eh_frame_fde_size
= 32;
261 static const unsigned char plt_eh_frame_fde
[plt_eh_frame_fde_size
];
264 // Actually fill the PLT contents for an executable (non-PIC).
266 class Output_data_plt_i386_exec
: public Output_data_plt_i386_standard
269 Output_data_plt_i386_exec(Layout
* layout
,
270 Output_data_space
* got_plt
,
271 Output_data_space
* got_irelative
)
272 : Output_data_plt_i386_standard(layout
, got_plt
, got_irelative
)
277 do_fill_first_plt_entry(unsigned char* pov
,
278 elfcpp::Elf_types
<32>::Elf_Addr got_address
);
281 do_fill_plt_entry(unsigned char* pov
,
282 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
283 unsigned int got_offset
,
284 unsigned int plt_offset
,
285 unsigned int plt_rel_offset
);
288 // The first entry in the PLT for an executable.
289 static const unsigned char first_plt_entry
[plt_entry_size
];
291 // Other entries in the PLT for an executable.
292 static const unsigned char plt_entry
[plt_entry_size
];
295 // Actually fill the PLT contents for a shared library (PIC).
297 class Output_data_plt_i386_dyn
: public Output_data_plt_i386_standard
300 Output_data_plt_i386_dyn(Layout
* layout
,
301 Output_data_space
* got_plt
,
302 Output_data_space
* got_irelative
)
303 : Output_data_plt_i386_standard(layout
, got_plt
, got_irelative
)
308 do_fill_first_plt_entry(unsigned char* pov
, elfcpp::Elf_types
<32>::Elf_Addr
);
311 do_fill_plt_entry(unsigned char* pov
,
312 elfcpp::Elf_types
<32>::Elf_Addr
,
313 unsigned int got_offset
,
314 unsigned int plt_offset
,
315 unsigned int plt_rel_offset
);
318 // The first entry in the PLT for a shared object.
319 static const unsigned char first_plt_entry
[plt_entry_size
];
321 // Other entries in the PLT for a shared object.
322 static const unsigned char plt_entry
[plt_entry_size
];
325 // The i386 target class.
326 // TLS info comes from
327 // http://people.redhat.com/drepper/tls.pdf
328 // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
330 class Target_i386
: public Sized_target
<32, false>
333 typedef Output_data_reloc
<elfcpp::SHT_REL
, true, 32, false> Reloc_section
;
335 Target_i386(const Target::Target_info
* info
= &i386_info
)
336 : Sized_target
<32, false>(info
),
337 got_(NULL
), plt_(NULL
), got_plt_(NULL
), got_irelative_(NULL
),
338 got_tlsdesc_(NULL
), global_offset_table_(NULL
), rel_dyn_(NULL
),
339 rel_irelative_(NULL
), copy_relocs_(elfcpp::R_386_COPY
),
340 got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
343 // Process the relocations to determine unreferenced sections for
344 // garbage collection.
346 gc_process_relocs(Symbol_table
* symtab
,
348 Sized_relobj_file
<32, false>* object
,
349 unsigned int data_shndx
,
350 unsigned int sh_type
,
351 const unsigned char* prelocs
,
353 Output_section
* output_section
,
354 bool needs_special_offset_handling
,
355 size_t local_symbol_count
,
356 const unsigned char* plocal_symbols
);
358 // Scan the relocations to look for symbol adjustments.
360 scan_relocs(Symbol_table
* symtab
,
362 Sized_relobj_file
<32, false>* object
,
363 unsigned int data_shndx
,
364 unsigned int sh_type
,
365 const unsigned char* prelocs
,
367 Output_section
* output_section
,
368 bool needs_special_offset_handling
,
369 size_t local_symbol_count
,
370 const unsigned char* plocal_symbols
);
372 // Finalize the sections.
374 do_finalize_sections(Layout
*, const Input_objects
*, Symbol_table
*);
376 // Return the value to use for a dynamic which requires special
379 do_dynsym_value(const Symbol
*) const;
381 // Relocate a section.
383 relocate_section(const Relocate_info
<32, false>*,
384 unsigned int sh_type
,
385 const unsigned char* prelocs
,
387 Output_section
* output_section
,
388 bool needs_special_offset_handling
,
390 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
391 section_size_type view_size
,
392 const Reloc_symbol_changes
*);
394 // Scan the relocs during a relocatable link.
396 scan_relocatable_relocs(Symbol_table
* symtab
,
398 Sized_relobj_file
<32, false>* object
,
399 unsigned int data_shndx
,
400 unsigned int sh_type
,
401 const unsigned char* prelocs
,
403 Output_section
* output_section
,
404 bool needs_special_offset_handling
,
405 size_t local_symbol_count
,
406 const unsigned char* plocal_symbols
,
407 Relocatable_relocs
*);
409 // Emit relocations for a section.
411 relocate_relocs(const Relocate_info
<32, false>*,
412 unsigned int sh_type
,
413 const unsigned char* prelocs
,
415 Output_section
* output_section
,
416 elfcpp::Elf_types
<32>::Elf_Off offset_in_output_section
,
417 const Relocatable_relocs
*,
419 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
420 section_size_type view_size
,
421 unsigned char* reloc_view
,
422 section_size_type reloc_view_size
);
424 // Return a string used to fill a code section with nops.
426 do_code_fill(section_size_type length
) const;
428 // Return whether SYM is defined by the ABI.
430 do_is_defined_by_abi(const Symbol
* sym
) const
431 { return strcmp(sym
->name(), "___tls_get_addr") == 0; }
433 // Return whether a symbol name implies a local label. The UnixWare
434 // 2.1 cc generates temporary symbols that start with .X, so we
435 // recognize them here. FIXME: do other SVR4 compilers also use .X?.
436 // If so, we should move the .X recognition into
437 // Target::do_is_local_label_name.
439 do_is_local_label_name(const char* name
) const
441 if (name
[0] == '.' && name
[1] == 'X')
443 return Target::do_is_local_label_name(name
);
446 // Return the PLT address to use for a global symbol.
448 do_plt_address_for_global(const Symbol
* gsym
) const
449 { return this->plt_section()->address_for_global(gsym
); }
452 do_plt_address_for_local(const Relobj
* relobj
, unsigned int symndx
) const
453 { return this->plt_section()->address_for_local(relobj
, symndx
); }
455 // We can tell whether we take the address of a function.
457 do_can_check_for_function_pointers() const
460 // Return the base for a DW_EH_PE_datarel encoding.
462 do_ehframe_datarel_base() const;
464 // Return whether SYM is call to a non-split function.
466 do_is_call_to_non_split(const Symbol
* sym
, unsigned int) const;
468 // Adjust -fsplit-stack code which calls non-split-stack code.
470 do_calls_non_split(Relobj
* object
, unsigned int shndx
,
471 section_offset_type fnoffset
, section_size_type fnsize
,
472 unsigned char* view
, section_size_type view_size
,
473 std::string
* from
, std::string
* to
) const;
475 // Return the size of the GOT section.
479 gold_assert(this->got_
!= NULL
);
480 return this->got_
->data_size();
483 // Return the number of entries in the GOT.
485 got_entry_count() const
487 if (this->got_
== NULL
)
489 return this->got_size() / 4;
492 // Return the number of entries in the PLT.
494 plt_entry_count() const;
496 // Return the offset of the first non-reserved PLT entry.
498 first_plt_entry_offset() const;
500 // Return the size of each PLT entry.
502 plt_entry_size() const;
505 // Instantiate the plt_ member.
506 // This chooses the right PLT flavor for an executable or a shared object.
507 Output_data_plt_i386
*
508 make_data_plt(Layout
* layout
,
509 Output_data_space
* got_plt
,
510 Output_data_space
* got_irelative
,
512 { return this->do_make_data_plt(layout
, got_plt
, got_irelative
, dyn
); }
514 virtual Output_data_plt_i386
*
515 do_make_data_plt(Layout
* layout
,
516 Output_data_space
* got_plt
,
517 Output_data_space
* got_irelative
,
521 return new Output_data_plt_i386_dyn(layout
, got_plt
, got_irelative
);
523 return new Output_data_plt_i386_exec(layout
, got_plt
, got_irelative
);
527 // The class which scans relocations.
532 get_reference_flags(unsigned int r_type
);
535 local(Symbol_table
* symtab
, Layout
* layout
, Target_i386
* target
,
536 Sized_relobj_file
<32, false>* object
,
537 unsigned int data_shndx
,
538 Output_section
* output_section
,
539 const elfcpp::Rel
<32, false>& reloc
, unsigned int r_type
,
540 const elfcpp::Sym
<32, false>& lsym
,
544 global(Symbol_table
* symtab
, Layout
* layout
, Target_i386
* target
,
545 Sized_relobj_file
<32, false>* object
,
546 unsigned int data_shndx
,
547 Output_section
* output_section
,
548 const elfcpp::Rel
<32, false>& reloc
, unsigned int r_type
,
552 local_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
554 Sized_relobj_file
<32, false>* object
,
555 unsigned int data_shndx
,
556 Output_section
* output_section
,
557 const elfcpp::Rel
<32, false>& reloc
,
559 const elfcpp::Sym
<32, false>& lsym
);
562 global_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
564 Sized_relobj_file
<32, false>* object
,
565 unsigned int data_shndx
,
566 Output_section
* output_section
,
567 const elfcpp::Rel
<32, false>& reloc
,
572 possible_function_pointer_reloc(unsigned int r_type
);
575 reloc_needs_plt_for_ifunc(Sized_relobj_file
<32, false>*,
576 unsigned int r_type
);
579 unsupported_reloc_local(Sized_relobj_file
<32, false>*, unsigned int r_type
);
582 unsupported_reloc_global(Sized_relobj_file
<32, false>*, unsigned int r_type
,
586 // The class which implements relocation.
591 : skip_call_tls_get_addr_(false),
592 local_dynamic_type_(LOCAL_DYNAMIC_NONE
)
597 if (this->skip_call_tls_get_addr_
)
599 // FIXME: This needs to specify the location somehow.
600 gold_error(_("missing expected TLS relocation"));
604 // Return whether the static relocation needs to be applied.
606 should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
609 Output_section
* output_section
);
611 // Do a relocation. Return false if the caller should not issue
612 // any warnings about this relocation.
614 relocate(const Relocate_info
<32, false>*, Target_i386
*, Output_section
*,
615 size_t relnum
, const elfcpp::Rel
<32, false>&,
616 unsigned int r_type
, const Sized_symbol
<32>*,
617 const Symbol_value
<32>*,
618 unsigned char*, elfcpp::Elf_types
<32>::Elf_Addr
,
622 // Do a TLS relocation.
624 relocate_tls(const Relocate_info
<32, false>*, Target_i386
* target
,
625 size_t relnum
, const elfcpp::Rel
<32, false>&,
626 unsigned int r_type
, const Sized_symbol
<32>*,
627 const Symbol_value
<32>*,
628 unsigned char*, elfcpp::Elf_types
<32>::Elf_Addr
,
631 // Do a TLS General-Dynamic to Initial-Exec transition.
633 tls_gd_to_ie(const Relocate_info
<32, false>*, size_t relnum
,
634 Output_segment
* tls_segment
,
635 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
636 elfcpp::Elf_types
<32>::Elf_Addr value
,
638 section_size_type view_size
);
640 // Do a TLS General-Dynamic to Local-Exec transition.
642 tls_gd_to_le(const Relocate_info
<32, false>*, size_t relnum
,
643 Output_segment
* tls_segment
,
644 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
645 elfcpp::Elf_types
<32>::Elf_Addr value
,
647 section_size_type view_size
);
649 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
652 tls_desc_gd_to_ie(const Relocate_info
<32, false>*, size_t relnum
,
653 Output_segment
* tls_segment
,
654 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
655 elfcpp::Elf_types
<32>::Elf_Addr value
,
657 section_size_type view_size
);
659 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
662 tls_desc_gd_to_le(const Relocate_info
<32, false>*, size_t relnum
,
663 Output_segment
* tls_segment
,
664 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
665 elfcpp::Elf_types
<32>::Elf_Addr value
,
667 section_size_type view_size
);
669 // Do a TLS Local-Dynamic to Local-Exec transition.
671 tls_ld_to_le(const Relocate_info
<32, false>*, size_t relnum
,
672 Output_segment
* tls_segment
,
673 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
674 elfcpp::Elf_types
<32>::Elf_Addr value
,
676 section_size_type view_size
);
678 // Do a TLS Initial-Exec to Local-Exec transition.
680 tls_ie_to_le(const Relocate_info
<32, false>*, size_t relnum
,
681 Output_segment
* tls_segment
,
682 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
683 elfcpp::Elf_types
<32>::Elf_Addr value
,
685 section_size_type view_size
);
687 // We need to keep track of which type of local dynamic relocation
688 // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
689 enum Local_dynamic_type
696 // This is set if we should skip the next reloc, which should be a
697 // PLT32 reloc against ___tls_get_addr.
698 bool skip_call_tls_get_addr_
;
699 // The type of local dynamic relocation we have seen in the section
700 // being relocated, if any.
701 Local_dynamic_type local_dynamic_type_
;
704 // A class which returns the size required for a relocation type,
705 // used while scanning relocs during a relocatable link.
706 class Relocatable_size_for_reloc
710 get_size_for_reloc(unsigned int, Relobj
*);
713 // Adjust TLS relocation type based on the options and whether this
714 // is a local symbol.
715 static tls::Tls_optimization
716 optimize_tls_reloc(bool is_final
, int r_type
);
718 // Get the GOT section, creating it if necessary.
719 Output_data_got
<32, false>*
720 got_section(Symbol_table
*, Layout
*);
722 // Get the GOT PLT section.
724 got_plt_section() const
726 gold_assert(this->got_plt_
!= NULL
);
727 return this->got_plt_
;
730 // Get the GOT section for TLSDESC entries.
731 Output_data_got
<32, false>*
732 got_tlsdesc_section() const
734 gold_assert(this->got_tlsdesc_
!= NULL
);
735 return this->got_tlsdesc_
;
738 // Create the PLT section.
740 make_plt_section(Symbol_table
* symtab
, Layout
* layout
);
742 // Create a PLT entry for a global symbol.
744 make_plt_entry(Symbol_table
*, Layout
*, Symbol
*);
746 // Create a PLT entry for a local STT_GNU_IFUNC symbol.
748 make_local_ifunc_plt_entry(Symbol_table
*, Layout
*,
749 Sized_relobj_file
<32, false>* relobj
,
750 unsigned int local_sym_index
);
752 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
754 define_tls_base_symbol(Symbol_table
*, Layout
*);
756 // Create a GOT entry for the TLS module index.
758 got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
759 Sized_relobj_file
<32, false>* object
);
761 // Get the PLT section.
762 Output_data_plt_i386
*
765 gold_assert(this->plt_
!= NULL
);
769 // Get the dynamic reloc section, creating it if necessary.
771 rel_dyn_section(Layout
*);
773 // Get the section to use for TLS_DESC relocations.
775 rel_tls_desc_section(Layout
*) const;
777 // Get the section to use for IRELATIVE relocations.
779 rel_irelative_section(Layout
*);
781 // Add a potential copy relocation.
783 copy_reloc(Symbol_table
* symtab
, Layout
* layout
,
784 Sized_relobj_file
<32, false>* object
,
785 unsigned int shndx
, Output_section
* output_section
,
786 Symbol
* sym
, const elfcpp::Rel
<32, false>& reloc
)
788 this->copy_relocs_
.copy_reloc(symtab
, layout
,
789 symtab
->get_sized_symbol
<32>(sym
),
790 object
, shndx
, output_section
, reloc
,
791 this->rel_dyn_section(layout
));
794 // Information about this specific target which we pass to the
795 // general Target structure.
796 static const Target::Target_info i386_info
;
798 // The types of GOT entries needed for this platform.
799 // These values are exposed to the ABI in an incremental link.
800 // Do not renumber existing values without changing the version
801 // number of the .gnu_incremental_inputs section.
804 GOT_TYPE_STANDARD
= 0, // GOT entry for a regular symbol
805 GOT_TYPE_TLS_NOFFSET
= 1, // GOT entry for negative TLS offset
806 GOT_TYPE_TLS_OFFSET
= 2, // GOT entry for positive TLS offset
807 GOT_TYPE_TLS_PAIR
= 3, // GOT entry for TLS module/offset pair
808 GOT_TYPE_TLS_DESC
= 4 // GOT entry for TLS_DESC pair
812 Output_data_got
<32, false>* got_
;
814 Output_data_plt_i386
* plt_
;
815 // The GOT PLT section.
816 Output_data_space
* got_plt_
;
817 // The GOT section for IRELATIVE relocations.
818 Output_data_space
* got_irelative_
;
819 // The GOT section for TLSDESC relocations.
820 Output_data_got
<32, false>* got_tlsdesc_
;
821 // The _GLOBAL_OFFSET_TABLE_ symbol.
822 Symbol
* global_offset_table_
;
823 // The dynamic reloc section.
824 Reloc_section
* rel_dyn_
;
825 // The section to use for IRELATIVE relocs.
826 Reloc_section
* rel_irelative_
;
827 // Relocs saved to avoid a COPY reloc.
828 Copy_relocs
<elfcpp::SHT_REL
, 32, false> copy_relocs_
;
829 // Offset of the GOT entry for the TLS module index.
830 unsigned int got_mod_index_offset_
;
831 // True if the _TLS_MODULE_BASE_ symbol has been defined.
832 bool tls_base_symbol_defined_
;
835 const Target::Target_info
Target_i386::i386_info
=
838 false, // is_big_endian
839 elfcpp::EM_386
, // machine_code
840 false, // has_make_symbol
841 false, // has_resolve
842 true, // has_code_fill
843 true, // is_default_stack_executable
844 true, // can_icf_inline_merge_sections
846 "/usr/lib/libc.so.1", // dynamic_linker
847 0x08048000, // default_text_segment_address
848 0x1000, // abi_pagesize (overridable by -z max-page-size)
849 0x1000, // common_pagesize (overridable by -z common-page-size)
850 false, // isolate_execinstr
852 elfcpp::SHN_UNDEF
, // small_common_shndx
853 elfcpp::SHN_UNDEF
, // large_common_shndx
854 0, // small_common_section_flags
855 0, // large_common_section_flags
856 NULL
, // attributes_section
857 NULL
, // attributes_vendor
858 "_start" // entry_symbol_name
861 // Get the GOT section, creating it if necessary.
863 Output_data_got
<32, false>*
864 Target_i386::got_section(Symbol_table
* symtab
, Layout
* layout
)
866 if (this->got_
== NULL
)
868 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
870 this->got_
= new Output_data_got
<32, false>();
872 // When using -z now, we can treat .got.plt as a relro section.
873 // Without -z now, it is modified after program startup by lazy
875 bool is_got_plt_relro
= parameters
->options().now();
876 Output_section_order got_order
= (is_got_plt_relro
879 Output_section_order got_plt_order
= (is_got_plt_relro
881 : ORDER_NON_RELRO_FIRST
);
883 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
885 | elfcpp::SHF_WRITE
),
886 this->got_
, got_order
, true);
888 this->got_plt_
= new Output_data_space(4, "** GOT PLT");
889 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
891 | elfcpp::SHF_WRITE
),
892 this->got_plt_
, got_plt_order
,
895 // The first three entries are reserved.
896 this->got_plt_
->set_current_data_size(3 * 4);
898 if (!is_got_plt_relro
)
900 // Those bytes can go into the relro segment.
901 layout
->increase_relro(3 * 4);
904 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
905 this->global_offset_table_
=
906 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
907 Symbol_table::PREDEFINED
,
909 0, 0, elfcpp::STT_OBJECT
,
911 elfcpp::STV_HIDDEN
, 0,
914 // If there are any IRELATIVE relocations, they get GOT entries
915 // in .got.plt after the jump slot relocations.
916 this->got_irelative_
= new Output_data_space(4, "** GOT IRELATIVE PLT");
917 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
919 | elfcpp::SHF_WRITE
),
920 this->got_irelative_
,
921 got_plt_order
, is_got_plt_relro
);
923 // If there are any TLSDESC relocations, they get GOT entries in
924 // .got.plt after the jump slot entries.
925 this->got_tlsdesc_
= new Output_data_got
<32, false>();
926 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
928 | elfcpp::SHF_WRITE
),
930 got_plt_order
, is_got_plt_relro
);
936 // Get the dynamic reloc section, creating it if necessary.
938 Target_i386::Reloc_section
*
939 Target_i386::rel_dyn_section(Layout
* layout
)
941 if (this->rel_dyn_
== NULL
)
943 gold_assert(layout
!= NULL
);
944 this->rel_dyn_
= new Reloc_section(parameters
->options().combreloc());
945 layout
->add_output_section_data(".rel.dyn", elfcpp::SHT_REL
,
946 elfcpp::SHF_ALLOC
, this->rel_dyn_
,
947 ORDER_DYNAMIC_RELOCS
, false);
949 return this->rel_dyn_
;
952 // Get the section to use for IRELATIVE relocs, creating it if
953 // necessary. These go in .rel.dyn, but only after all other dynamic
954 // relocations. They need to follow the other dynamic relocations so
955 // that they can refer to global variables initialized by those
958 Target_i386::Reloc_section
*
959 Target_i386::rel_irelative_section(Layout
* layout
)
961 if (this->rel_irelative_
== NULL
)
963 // Make sure we have already create the dynamic reloc section.
964 this->rel_dyn_section(layout
);
965 this->rel_irelative_
= new Reloc_section(false);
966 layout
->add_output_section_data(".rel.dyn", elfcpp::SHT_REL
,
967 elfcpp::SHF_ALLOC
, this->rel_irelative_
,
968 ORDER_DYNAMIC_RELOCS
, false);
969 gold_assert(this->rel_dyn_
->output_section()
970 == this->rel_irelative_
->output_section());
972 return this->rel_irelative_
;
975 // Create the PLT section. The ordinary .got section is an argument,
976 // since we need to refer to the start. We also create our own .got
977 // section just for PLT entries.
979 Output_data_plt_i386::Output_data_plt_i386(Layout
* layout
,
981 Output_data_space
* got_plt
,
982 Output_data_space
* got_irelative
)
983 : Output_section_data(addralign
),
984 layout_(layout
), tls_desc_rel_(NULL
),
985 irelative_rel_(NULL
), got_plt_(got_plt
), got_irelative_(got_irelative
),
986 count_(0), irelative_count_(0), global_ifuncs_(), local_ifuncs_()
988 this->rel_
= new Reloc_section(false);
989 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
990 elfcpp::SHF_ALLOC
, this->rel_
,
991 ORDER_DYNAMIC_PLT_RELOCS
, false);
995 Output_data_plt_i386::do_adjust_output_section(Output_section
* os
)
997 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
998 // linker, and so do we.
1002 // Add an entry to the PLT.
1005 Output_data_plt_i386::add_entry(Symbol_table
* symtab
, Layout
* layout
,
1008 gold_assert(!gsym
->has_plt_offset());
1010 // Every PLT entry needs a reloc.
1011 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1012 && gsym
->can_use_relative_reloc(false))
1014 gsym
->set_plt_offset(this->irelative_count_
* this->get_plt_entry_size());
1015 ++this->irelative_count_
;
1016 section_offset_type got_offset
=
1017 this->got_irelative_
->current_data_size();
1018 this->got_irelative_
->set_current_data_size(got_offset
+ 4);
1019 Reloc_section
* rel
= this->rel_irelative(symtab
, layout
);
1020 rel
->add_symbolless_global_addend(gsym
, elfcpp::R_386_IRELATIVE
,
1021 this->got_irelative_
, got_offset
);
1022 struct Global_ifunc gi
;
1024 gi
.got_offset
= got_offset
;
1025 this->global_ifuncs_
.push_back(gi
);
1029 // When setting the PLT offset we skip the initial reserved PLT
1031 gsym
->set_plt_offset((this->count_
+ 1) * this->get_plt_entry_size());
1035 section_offset_type got_offset
= this->got_plt_
->current_data_size();
1037 // Every PLT entry needs a GOT entry which points back to the
1038 // PLT entry (this will be changed by the dynamic linker,
1039 // normally lazily when the function is called).
1040 this->got_plt_
->set_current_data_size(got_offset
+ 4);
1042 gsym
->set_needs_dynsym_entry();
1043 this->rel_
->add_global(gsym
, elfcpp::R_386_JUMP_SLOT
, this->got_plt_
,
1047 // Note that we don't need to save the symbol. The contents of the
1048 // PLT are independent of which symbols are used. The symbols only
1049 // appear in the relocations.
1052 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
1056 Output_data_plt_i386::add_local_ifunc_entry(
1057 Symbol_table
* symtab
,
1059 Sized_relobj_file
<32, false>* relobj
,
1060 unsigned int local_sym_index
)
1062 unsigned int plt_offset
= this->irelative_count_
* this->get_plt_entry_size();
1063 ++this->irelative_count_
;
1065 section_offset_type got_offset
= this->got_irelative_
->current_data_size();
1067 // Every PLT entry needs a GOT entry which points back to the PLT
1069 this->got_irelative_
->set_current_data_size(got_offset
+ 4);
1071 // Every PLT entry needs a reloc.
1072 Reloc_section
* rel
= this->rel_irelative(symtab
, layout
);
1073 rel
->add_symbolless_local_addend(relobj
, local_sym_index
,
1074 elfcpp::R_386_IRELATIVE
,
1075 this->got_irelative_
, got_offset
);
1077 struct Local_ifunc li
;
1079 li
.local_sym_index
= local_sym_index
;
1080 li
.got_offset
= got_offset
;
1081 this->local_ifuncs_
.push_back(li
);
1086 // Return where the TLS_DESC relocations should go, creating it if
1087 // necessary. These follow the JUMP_SLOT relocations.
1089 Output_data_plt_i386::Reloc_section
*
1090 Output_data_plt_i386::rel_tls_desc(Layout
* layout
)
1092 if (this->tls_desc_rel_
== NULL
)
1094 this->tls_desc_rel_
= new Reloc_section(false);
1095 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
1096 elfcpp::SHF_ALLOC
, this->tls_desc_rel_
,
1097 ORDER_DYNAMIC_PLT_RELOCS
, false);
1098 gold_assert(this->tls_desc_rel_
->output_section()
1099 == this->rel_
->output_section());
1101 return this->tls_desc_rel_
;
1104 // Return where the IRELATIVE relocations should go in the PLT. These
1105 // follow the JUMP_SLOT and TLS_DESC relocations.
1107 Output_data_plt_i386::Reloc_section
*
1108 Output_data_plt_i386::rel_irelative(Symbol_table
* symtab
, Layout
* layout
)
1110 if (this->irelative_rel_
== NULL
)
1112 // Make sure we have a place for the TLS_DESC relocations, in
1113 // case we see any later on.
1114 this->rel_tls_desc(layout
);
1115 this->irelative_rel_
= new Reloc_section(false);
1116 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
1117 elfcpp::SHF_ALLOC
, this->irelative_rel_
,
1118 ORDER_DYNAMIC_PLT_RELOCS
, false);
1119 gold_assert(this->irelative_rel_
->output_section()
1120 == this->rel_
->output_section());
1122 if (parameters
->doing_static_link())
1124 // A statically linked executable will only have a .rel.plt
1125 // section to hold R_386_IRELATIVE relocs for STT_GNU_IFUNC
1126 // symbols. The library will use these symbols to locate
1127 // the IRELATIVE relocs at program startup time.
1128 symtab
->define_in_output_data("__rel_iplt_start", NULL
,
1129 Symbol_table::PREDEFINED
,
1130 this->irelative_rel_
, 0, 0,
1131 elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
1132 elfcpp::STV_HIDDEN
, 0, false, true);
1133 symtab
->define_in_output_data("__rel_iplt_end", NULL
,
1134 Symbol_table::PREDEFINED
,
1135 this->irelative_rel_
, 0, 0,
1136 elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
1137 elfcpp::STV_HIDDEN
, 0, true, true);
1140 return this->irelative_rel_
;
1143 // Return the PLT address to use for a global symbol.
1146 Output_data_plt_i386::address_for_global(const Symbol
* gsym
)
1148 uint64_t offset
= 0;
1149 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1150 && gsym
->can_use_relative_reloc(false))
1151 offset
= (this->count_
+ 1) * this->get_plt_entry_size();
1152 return this->address() + offset
+ gsym
->plt_offset();
1155 // Return the PLT address to use for a local symbol. These are always
1156 // IRELATIVE relocs.
1159 Output_data_plt_i386::address_for_local(const Relobj
* object
,
1162 return (this->address()
1163 + (this->count_
+ 1) * this->get_plt_entry_size()
1164 + object
->local_plt_offset(r_sym
));
1167 // The first entry in the PLT for an executable.
1169 const unsigned char Output_data_plt_i386_exec::first_plt_entry
[plt_entry_size
] =
1171 0xff, 0x35, // pushl contents of memory address
1172 0, 0, 0, 0, // replaced with address of .got + 4
1173 0xff, 0x25, // jmp indirect
1174 0, 0, 0, 0, // replaced with address of .got + 8
1175 0, 0, 0, 0 // unused
1179 Output_data_plt_i386_exec::do_fill_first_plt_entry(
1181 elfcpp::Elf_types
<32>::Elf_Addr got_address
)
1183 memcpy(pov
, first_plt_entry
, plt_entry_size
);
1184 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 4);
1185 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 8);
1188 // The first entry in the PLT for a shared object.
1190 const unsigned char Output_data_plt_i386_dyn::first_plt_entry
[plt_entry_size
] =
1192 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
1193 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
1194 0, 0, 0, 0 // unused
1198 Output_data_plt_i386_dyn::do_fill_first_plt_entry(
1200 elfcpp::Elf_types
<32>::Elf_Addr
)
1202 memcpy(pov
, first_plt_entry
, plt_entry_size
);
1205 // Subsequent entries in the PLT for an executable.
1207 const unsigned char Output_data_plt_i386_exec::plt_entry
[plt_entry_size
] =
1209 0xff, 0x25, // jmp indirect
1210 0, 0, 0, 0, // replaced with address of symbol in .got
1211 0x68, // pushl immediate
1212 0, 0, 0, 0, // replaced with offset into relocation table
1213 0xe9, // jmp relative
1214 0, 0, 0, 0 // replaced with offset to start of .plt
1218 Output_data_plt_i386_exec::do_fill_plt_entry(
1220 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
1221 unsigned int got_offset
,
1222 unsigned int plt_offset
,
1223 unsigned int plt_rel_offset
)
1225 memcpy(pov
, plt_entry
, plt_entry_size
);
1226 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
1227 got_address
+ got_offset
);
1228 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_rel_offset
);
1229 elfcpp::Swap
<32, false>::writeval(pov
+ 12, - (plt_offset
+ 12 + 4));
1233 // Subsequent entries in the PLT for a shared object.
1235 const unsigned char Output_data_plt_i386_dyn::plt_entry
[plt_entry_size
] =
1237 0xff, 0xa3, // jmp *offset(%ebx)
1238 0, 0, 0, 0, // replaced with offset of symbol in .got
1239 0x68, // pushl immediate
1240 0, 0, 0, 0, // replaced with offset into relocation table
1241 0xe9, // jmp relative
1242 0, 0, 0, 0 // replaced with offset to start of .plt
1246 Output_data_plt_i386_dyn::do_fill_plt_entry(unsigned char* pov
,
1247 elfcpp::Elf_types
<32>::Elf_Addr
,
1248 unsigned int got_offset
,
1249 unsigned int plt_offset
,
1250 unsigned int plt_rel_offset
)
1252 memcpy(pov
, plt_entry
, plt_entry_size
);
1253 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
1254 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_rel_offset
);
1255 elfcpp::Swap
<32, false>::writeval(pov
+ 12, - (plt_offset
+ 12 + 4));
1259 // The .eh_frame unwind information for the PLT.
1262 Output_data_plt_i386::plt_eh_frame_cie
[plt_eh_frame_cie_size
] =
1265 'z', // Augmentation: augmentation size included.
1266 'R', // Augmentation: FDE encoding included.
1267 '\0', // End of augmentation string.
1268 1, // Code alignment factor.
1269 0x7c, // Data alignment factor.
1270 8, // Return address column.
1271 1, // Augmentation size.
1272 (elfcpp::DW_EH_PE_pcrel
// FDE encoding.
1273 | elfcpp::DW_EH_PE_sdata4
),
1274 elfcpp::DW_CFA_def_cfa
, 4, 4, // DW_CFA_def_cfa: r4 (esp) ofs 4.
1275 elfcpp::DW_CFA_offset
+ 8, 1, // DW_CFA_offset: r8 (eip) at cfa-4.
1276 elfcpp::DW_CFA_nop
, // Align to 16 bytes.
1281 Output_data_plt_i386_standard::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
1283 0, 0, 0, 0, // Replaced with offset to .plt.
1284 0, 0, 0, 0, // Replaced with size of .plt.
1285 0, // Augmentation size.
1286 elfcpp::DW_CFA_def_cfa_offset
, 8, // DW_CFA_def_cfa_offset: 8.
1287 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
1288 elfcpp::DW_CFA_def_cfa_offset
, 12, // DW_CFA_def_cfa_offset: 12.
1289 elfcpp::DW_CFA_advance_loc
+ 10, // Advance 10 to __PLT__ + 16.
1290 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
1291 11, // Block length.
1292 elfcpp::DW_OP_breg4
, 4, // Push %esp + 4.
1293 elfcpp::DW_OP_breg8
, 0, // Push %eip.
1294 elfcpp::DW_OP_lit15
, // Push 0xf.
1295 elfcpp::DW_OP_and
, // & (%eip & 0xf).
1296 elfcpp::DW_OP_lit11
, // Push 0xb.
1297 elfcpp::DW_OP_ge
, // >= ((%eip & 0xf) >= 0xb)
1298 elfcpp::DW_OP_lit2
, // Push 2.
1299 elfcpp::DW_OP_shl
, // << (((%eip & 0xf) >= 0xb) << 2)
1300 elfcpp::DW_OP_plus
, // + ((((%eip&0xf)>=0xb)<<2)+%esp+4
1301 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
1307 // Write out the PLT. This uses the hand-coded instructions above,
1308 // and adjusts them as needed. This is all specified by the i386 ELF
1309 // Processor Supplement.
1312 Output_data_plt_i386::do_write(Output_file
* of
)
1314 const off_t offset
= this->offset();
1315 const section_size_type oview_size
=
1316 convert_to_section_size_type(this->data_size());
1317 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
1319 const off_t got_file_offset
= this->got_plt_
->offset();
1320 gold_assert(parameters
->incremental_update()
1321 || (got_file_offset
+ this->got_plt_
->data_size()
1322 == this->got_irelative_
->offset()));
1323 const section_size_type got_size
=
1324 convert_to_section_size_type(this->got_plt_
->data_size()
1325 + this->got_irelative_
->data_size());
1326 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
1329 unsigned char* pov
= oview
;
1331 elfcpp::Elf_types
<32>::Elf_Addr plt_address
= this->address();
1332 elfcpp::Elf_types
<32>::Elf_Addr got_address
= this->got_plt_
->address();
1334 this->fill_first_plt_entry(pov
, got_address
);
1335 pov
+= this->get_plt_entry_size();
1337 unsigned char* got_pov
= got_view
;
1339 // The first entry in the GOT is the address of the .dynamic section
1340 // aka the PT_DYNAMIC segment. The next two entries are reserved.
1341 // We saved space for them when we created the section in
1342 // Target_i386::got_section.
1343 Output_section
* dynamic
= this->layout_
->dynamic_section();
1344 uint32_t dynamic_addr
= dynamic
== NULL
? 0 : dynamic
->address();
1345 elfcpp::Swap
<32, false>::writeval(got_pov
, dynamic_addr
);
1347 memset(got_pov
, 0, 8);
1350 const int rel_size
= elfcpp::Elf_sizes
<32>::rel_size
;
1352 unsigned int plt_offset
= this->get_plt_entry_size();
1353 unsigned int plt_rel_offset
= 0;
1354 unsigned int got_offset
= 12;
1355 const unsigned int count
= this->count_
+ this->irelative_count_
;
1356 for (unsigned int i
= 0;
1359 pov
+= this->get_plt_entry_size(),
1361 plt_offset
+= this->get_plt_entry_size(),
1362 plt_rel_offset
+= rel_size
,
1365 // Set and adjust the PLT entry itself.
1366 unsigned int lazy_offset
= this->fill_plt_entry(pov
,
1372 // Set the entry in the GOT.
1373 elfcpp::Swap
<32, false>::writeval(got_pov
,
1374 plt_address
+ plt_offset
+ lazy_offset
);
1377 // If any STT_GNU_IFUNC symbols have PLT entries, we need to change
1378 // the GOT to point to the actual symbol value, rather than point to
1379 // the PLT entry. That will let the dynamic linker call the right
1380 // function when resolving IRELATIVE relocations.
1381 unsigned char* got_irelative_view
= got_view
+ this->got_plt_
->data_size();
1382 for (std::vector
<Global_ifunc
>::const_iterator p
=
1383 this->global_ifuncs_
.begin();
1384 p
!= this->global_ifuncs_
.end();
1387 const Sized_symbol
<32>* ssym
=
1388 static_cast<const Sized_symbol
<32>*>(p
->sym
);
1389 elfcpp::Swap
<32, false>::writeval(got_irelative_view
+ p
->got_offset
,
1393 for (std::vector
<Local_ifunc
>::const_iterator p
=
1394 this->local_ifuncs_
.begin();
1395 p
!= this->local_ifuncs_
.end();
1398 const Symbol_value
<32>* psymval
=
1399 p
->object
->local_symbol(p
->local_sym_index
);
1400 elfcpp::Swap
<32, false>::writeval(got_irelative_view
+ p
->got_offset
,
1401 psymval
->value(p
->object
, 0));
1404 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
1405 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
1407 of
->write_output_view(offset
, oview_size
, oview
);
1408 of
->write_output_view(got_file_offset
, got_size
, got_view
);
1411 // Create the PLT section.
1414 Target_i386::make_plt_section(Symbol_table
* symtab
, Layout
* layout
)
1416 if (this->plt_
== NULL
)
1418 // Create the GOT sections first.
1419 this->got_section(symtab
, layout
);
1421 const bool dyn
= parameters
->options().output_is_position_independent();
1422 this->plt_
= this->make_data_plt(layout
,
1424 this->got_irelative_
,
1427 // Add unwind information if requested.
1428 if (parameters
->options().ld_generated_unwind_info())
1429 this->plt_
->add_eh_frame(layout
);
1431 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
1433 | elfcpp::SHF_EXECINSTR
),
1434 this->plt_
, ORDER_PLT
, false);
1436 // Make the sh_info field of .rel.plt point to .plt.
1437 Output_section
* rel_plt_os
= this->plt_
->rel_plt()->output_section();
1438 rel_plt_os
->set_info_section(this->plt_
->output_section());
1442 // Create a PLT entry for a global symbol.
1445 Target_i386::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
, Symbol
* gsym
)
1447 if (gsym
->has_plt_offset())
1449 if (this->plt_
== NULL
)
1450 this->make_plt_section(symtab
, layout
);
1451 this->plt_
->add_entry(symtab
, layout
, gsym
);
1454 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1457 Target_i386::make_local_ifunc_plt_entry(Symbol_table
* symtab
, Layout
* layout
,
1458 Sized_relobj_file
<32, false>* relobj
,
1459 unsigned int local_sym_index
)
1461 if (relobj
->local_has_plt_offset(local_sym_index
))
1463 if (this->plt_
== NULL
)
1464 this->make_plt_section(symtab
, layout
);
1465 unsigned int plt_offset
= this->plt_
->add_local_ifunc_entry(symtab
, layout
,
1468 relobj
->set_local_plt_offset(local_sym_index
, plt_offset
);
1471 // Return the number of entries in the PLT.
1474 Target_i386::plt_entry_count() const
1476 if (this->plt_
== NULL
)
1478 return this->plt_
->entry_count();
1481 // Return the offset of the first non-reserved PLT entry.
1484 Target_i386::first_plt_entry_offset() const
1486 return this->plt_
->first_plt_entry_offset();
1489 // Return the size of each PLT entry.
1492 Target_i386::plt_entry_size() const
1494 return this->plt_
->get_plt_entry_size();
1497 // Get the section to use for TLS_DESC relocations.
1499 Target_i386::Reloc_section
*
1500 Target_i386::rel_tls_desc_section(Layout
* layout
) const
1502 return this->plt_section()->rel_tls_desc(layout
);
1505 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1508 Target_i386::define_tls_base_symbol(Symbol_table
* symtab
, Layout
* layout
)
1510 if (this->tls_base_symbol_defined_
)
1513 Output_segment
* tls_segment
= layout
->tls_segment();
1514 if (tls_segment
!= NULL
)
1516 bool is_exec
= parameters
->options().output_is_executable();
1517 symtab
->define_in_output_segment("_TLS_MODULE_BASE_", NULL
,
1518 Symbol_table::PREDEFINED
,
1522 elfcpp::STV_HIDDEN
, 0,
1524 ? Symbol::SEGMENT_END
1525 : Symbol::SEGMENT_START
),
1528 this->tls_base_symbol_defined_
= true;
1531 // Create a GOT entry for the TLS module index.
1534 Target_i386::got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
1535 Sized_relobj_file
<32, false>* object
)
1537 if (this->got_mod_index_offset_
== -1U)
1539 gold_assert(symtab
!= NULL
&& layout
!= NULL
&& object
!= NULL
);
1540 Reloc_section
* rel_dyn
= this->rel_dyn_section(layout
);
1541 Output_data_got
<32, false>* got
= this->got_section(symtab
, layout
);
1542 unsigned int got_offset
= got
->add_constant(0);
1543 rel_dyn
->add_local(object
, 0, elfcpp::R_386_TLS_DTPMOD32
, got
,
1545 got
->add_constant(0);
1546 this->got_mod_index_offset_
= got_offset
;
1548 return this->got_mod_index_offset_
;
1551 // Optimize the TLS relocation type based on what we know about the
1552 // symbol. IS_FINAL is true if the final address of this symbol is
1553 // known at link time.
1555 tls::Tls_optimization
1556 Target_i386::optimize_tls_reloc(bool is_final
, int r_type
)
1558 // If we are generating a shared library, then we can't do anything
1560 if (parameters
->options().shared())
1561 return tls::TLSOPT_NONE
;
1565 case elfcpp::R_386_TLS_GD
:
1566 case elfcpp::R_386_TLS_GOTDESC
:
1567 case elfcpp::R_386_TLS_DESC_CALL
:
1568 // These are General-Dynamic which permits fully general TLS
1569 // access. Since we know that we are generating an executable,
1570 // we can convert this to Initial-Exec. If we also know that
1571 // this is a local symbol, we can further switch to Local-Exec.
1573 return tls::TLSOPT_TO_LE
;
1574 return tls::TLSOPT_TO_IE
;
1576 case elfcpp::R_386_TLS_LDM
:
1577 // This is Local-Dynamic, which refers to a local symbol in the
1578 // dynamic TLS block. Since we know that we generating an
1579 // executable, we can switch to Local-Exec.
1580 return tls::TLSOPT_TO_LE
;
1582 case elfcpp::R_386_TLS_LDO_32
:
1583 // Another type of Local-Dynamic relocation.
1584 return tls::TLSOPT_TO_LE
;
1586 case elfcpp::R_386_TLS_IE
:
1587 case elfcpp::R_386_TLS_GOTIE
:
1588 case elfcpp::R_386_TLS_IE_32
:
1589 // These are Initial-Exec relocs which get the thread offset
1590 // from the GOT. If we know that we are linking against the
1591 // local symbol, we can switch to Local-Exec, which links the
1592 // thread offset into the instruction.
1594 return tls::TLSOPT_TO_LE
;
1595 return tls::TLSOPT_NONE
;
1597 case elfcpp::R_386_TLS_LE
:
1598 case elfcpp::R_386_TLS_LE_32
:
1599 // When we already have Local-Exec, there is nothing further we
1601 return tls::TLSOPT_NONE
;
1608 // Get the Reference_flags for a particular relocation.
1611 Target_i386::Scan::get_reference_flags(unsigned int r_type
)
1615 case elfcpp::R_386_NONE
:
1616 case elfcpp::R_386_GNU_VTINHERIT
:
1617 case elfcpp::R_386_GNU_VTENTRY
:
1618 case elfcpp::R_386_GOTPC
:
1619 // No symbol reference.
1622 case elfcpp::R_386_32
:
1623 case elfcpp::R_386_16
:
1624 case elfcpp::R_386_8
:
1625 return Symbol::ABSOLUTE_REF
;
1627 case elfcpp::R_386_PC32
:
1628 case elfcpp::R_386_PC16
:
1629 case elfcpp::R_386_PC8
:
1630 case elfcpp::R_386_GOTOFF
:
1631 return Symbol::RELATIVE_REF
;
1633 case elfcpp::R_386_PLT32
:
1634 return Symbol::FUNCTION_CALL
| Symbol::RELATIVE_REF
;
1636 case elfcpp::R_386_GOT32
:
1638 return Symbol::ABSOLUTE_REF
;
1640 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1641 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1642 case elfcpp::R_386_TLS_DESC_CALL
:
1643 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1644 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1645 case elfcpp::R_386_TLS_IE
: // Initial-exec
1646 case elfcpp::R_386_TLS_IE_32
:
1647 case elfcpp::R_386_TLS_GOTIE
:
1648 case elfcpp::R_386_TLS_LE
: // Local-exec
1649 case elfcpp::R_386_TLS_LE_32
:
1650 return Symbol::TLS_REF
;
1652 case elfcpp::R_386_COPY
:
1653 case elfcpp::R_386_GLOB_DAT
:
1654 case elfcpp::R_386_JUMP_SLOT
:
1655 case elfcpp::R_386_RELATIVE
:
1656 case elfcpp::R_386_IRELATIVE
:
1657 case elfcpp::R_386_TLS_TPOFF
:
1658 case elfcpp::R_386_TLS_DTPMOD32
:
1659 case elfcpp::R_386_TLS_DTPOFF32
:
1660 case elfcpp::R_386_TLS_TPOFF32
:
1661 case elfcpp::R_386_TLS_DESC
:
1662 case elfcpp::R_386_32PLT
:
1663 case elfcpp::R_386_TLS_GD_32
:
1664 case elfcpp::R_386_TLS_GD_PUSH
:
1665 case elfcpp::R_386_TLS_GD_CALL
:
1666 case elfcpp::R_386_TLS_GD_POP
:
1667 case elfcpp::R_386_TLS_LDM_32
:
1668 case elfcpp::R_386_TLS_LDM_PUSH
:
1669 case elfcpp::R_386_TLS_LDM_CALL
:
1670 case elfcpp::R_386_TLS_LDM_POP
:
1671 case elfcpp::R_386_USED_BY_INTEL_200
:
1673 // Not expected. We will give an error later.
1678 // Report an unsupported relocation against a local symbol.
1681 Target_i386::Scan::unsupported_reloc_local(Sized_relobj_file
<32, false>* object
,
1682 unsigned int r_type
)
1684 gold_error(_("%s: unsupported reloc %u against local symbol"),
1685 object
->name().c_str(), r_type
);
1688 // Return whether we need to make a PLT entry for a relocation of a
1689 // given type against a STT_GNU_IFUNC symbol.
1692 Target_i386::Scan::reloc_needs_plt_for_ifunc(
1693 Sized_relobj_file
<32, false>* object
,
1694 unsigned int r_type
)
1696 int flags
= Scan::get_reference_flags(r_type
);
1697 if (flags
& Symbol::TLS_REF
)
1698 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
1699 object
->name().c_str(), r_type
);
1703 // Scan a relocation for a local symbol.
1706 Target_i386::Scan::local(Symbol_table
* symtab
,
1708 Target_i386
* target
,
1709 Sized_relobj_file
<32, false>* object
,
1710 unsigned int data_shndx
,
1711 Output_section
* output_section
,
1712 const elfcpp::Rel
<32, false>& reloc
,
1713 unsigned int r_type
,
1714 const elfcpp::Sym
<32, false>& lsym
,
1720 // A local STT_GNU_IFUNC symbol may require a PLT entry.
1721 if (lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
1722 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
1724 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1725 target
->make_local_ifunc_plt_entry(symtab
, layout
, object
, r_sym
);
1730 case elfcpp::R_386_NONE
:
1731 case elfcpp::R_386_GNU_VTINHERIT
:
1732 case elfcpp::R_386_GNU_VTENTRY
:
1735 case elfcpp::R_386_32
:
1736 // If building a shared library (or a position-independent
1737 // executable), we need to create a dynamic relocation for
1738 // this location. The relocation applied at link time will
1739 // apply the link-time value, so we flag the location with
1740 // an R_386_RELATIVE relocation so the dynamic loader can
1741 // relocate it easily.
1742 if (parameters
->options().output_is_position_independent())
1744 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1745 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1746 rel_dyn
->add_local_relative(object
, r_sym
, elfcpp::R_386_RELATIVE
,
1747 output_section
, data_shndx
,
1748 reloc
.get_r_offset());
1752 case elfcpp::R_386_16
:
1753 case elfcpp::R_386_8
:
1754 // If building a shared library (or a position-independent
1755 // executable), we need to create a dynamic relocation for
1756 // this location. Because the addend needs to remain in the
1757 // data section, we need to be careful not to apply this
1758 // relocation statically.
1759 if (parameters
->options().output_is_position_independent())
1761 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1762 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1763 if (lsym
.get_st_type() != elfcpp::STT_SECTION
)
1764 rel_dyn
->add_local(object
, r_sym
, r_type
, output_section
,
1765 data_shndx
, reloc
.get_r_offset());
1768 gold_assert(lsym
.get_st_value() == 0);
1769 unsigned int shndx
= lsym
.get_st_shndx();
1771 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
,
1774 object
->error(_("section symbol %u has bad shndx %u"),
1777 rel_dyn
->add_local_section(object
, shndx
,
1778 r_type
, output_section
,
1779 data_shndx
, reloc
.get_r_offset());
1784 case elfcpp::R_386_PC32
:
1785 case elfcpp::R_386_PC16
:
1786 case elfcpp::R_386_PC8
:
1789 case elfcpp::R_386_PLT32
:
1790 // Since we know this is a local symbol, we can handle this as a
1794 case elfcpp::R_386_GOTOFF
:
1795 case elfcpp::R_386_GOTPC
:
1796 // We need a GOT section.
1797 target
->got_section(symtab
, layout
);
1800 case elfcpp::R_386_GOT32
:
1802 // The symbol requires a GOT entry.
1803 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
1804 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1806 // For a STT_GNU_IFUNC symbol we want the PLT offset. That
1807 // lets function pointers compare correctly with shared
1808 // libraries. Otherwise we would need an IRELATIVE reloc.
1810 if (lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
)
1811 is_new
= got
->add_local_plt(object
, r_sym
, GOT_TYPE_STANDARD
);
1813 is_new
= got
->add_local(object
, r_sym
, GOT_TYPE_STANDARD
);
1816 // If we are generating a shared object, we need to add a
1817 // dynamic RELATIVE relocation for this symbol's GOT entry.
1818 if (parameters
->options().output_is_position_independent())
1820 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1821 unsigned int got_offset
=
1822 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
);
1823 rel_dyn
->add_local_relative(object
, r_sym
,
1824 elfcpp::R_386_RELATIVE
,
1831 // These are relocations which should only be seen by the
1832 // dynamic linker, and should never be seen here.
1833 case elfcpp::R_386_COPY
:
1834 case elfcpp::R_386_GLOB_DAT
:
1835 case elfcpp::R_386_JUMP_SLOT
:
1836 case elfcpp::R_386_RELATIVE
:
1837 case elfcpp::R_386_IRELATIVE
:
1838 case elfcpp::R_386_TLS_TPOFF
:
1839 case elfcpp::R_386_TLS_DTPMOD32
:
1840 case elfcpp::R_386_TLS_DTPOFF32
:
1841 case elfcpp::R_386_TLS_TPOFF32
:
1842 case elfcpp::R_386_TLS_DESC
:
1843 gold_error(_("%s: unexpected reloc %u in object file"),
1844 object
->name().c_str(), r_type
);
1847 // These are initial TLS relocs, which are expected when
1849 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1850 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1851 case elfcpp::R_386_TLS_DESC_CALL
:
1852 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1853 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1854 case elfcpp::R_386_TLS_IE
: // Initial-exec
1855 case elfcpp::R_386_TLS_IE_32
:
1856 case elfcpp::R_386_TLS_GOTIE
:
1857 case elfcpp::R_386_TLS_LE
: // Local-exec
1858 case elfcpp::R_386_TLS_LE_32
:
1860 bool output_is_shared
= parameters
->options().shared();
1861 const tls::Tls_optimization optimized_type
1862 = Target_i386::optimize_tls_reloc(!output_is_shared
, r_type
);
1865 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1866 if (optimized_type
== tls::TLSOPT_NONE
)
1868 // Create a pair of GOT entries for the module index and
1869 // dtv-relative offset.
1870 Output_data_got
<32, false>* got
1871 = target
->got_section(symtab
, layout
);
1872 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1873 unsigned int shndx
= lsym
.get_st_shndx();
1875 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
1877 object
->error(_("local symbol %u has bad shndx %u"),
1880 got
->add_local_pair_with_rel(object
, r_sym
, shndx
,
1882 target
->rel_dyn_section(layout
),
1883 elfcpp::R_386_TLS_DTPMOD32
);
1885 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1886 unsupported_reloc_local(object
, r_type
);
1889 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva)
1890 target
->define_tls_base_symbol(symtab
, layout
);
1891 if (optimized_type
== tls::TLSOPT_NONE
)
1893 // Create a double GOT entry with an R_386_TLS_DESC
1894 // reloc. The R_386_TLS_DESC reloc is resolved
1895 // lazily, so the GOT entry needs to be in an area in
1896 // .got.plt, not .got. Call got_section to make sure
1897 // the section has been created.
1898 target
->got_section(symtab
, layout
);
1899 Output_data_got
<32, false>* got
= target
->got_tlsdesc_section();
1900 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1901 if (!object
->local_has_got_offset(r_sym
, GOT_TYPE_TLS_DESC
))
1903 unsigned int got_offset
= got
->add_constant(0);
1904 // The local symbol value is stored in the second
1906 got
->add_local(object
, r_sym
, GOT_TYPE_TLS_DESC
);
1907 // That set the GOT offset of the local symbol to
1908 // point to the second entry, but we want it to
1909 // point to the first.
1910 object
->set_local_got_offset(r_sym
, GOT_TYPE_TLS_DESC
,
1912 Reloc_section
* rt
= target
->rel_tls_desc_section(layout
);
1913 rt
->add_absolute(elfcpp::R_386_TLS_DESC
, got
, got_offset
);
1916 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1917 unsupported_reloc_local(object
, r_type
);
1920 case elfcpp::R_386_TLS_DESC_CALL
:
1923 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1924 if (optimized_type
== tls::TLSOPT_NONE
)
1926 // Create a GOT entry for the module index.
1927 target
->got_mod_index_entry(symtab
, layout
, object
);
1929 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1930 unsupported_reloc_local(object
, r_type
);
1933 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1936 case elfcpp::R_386_TLS_IE
: // Initial-exec
1937 case elfcpp::R_386_TLS_IE_32
:
1938 case elfcpp::R_386_TLS_GOTIE
:
1939 layout
->set_has_static_tls();
1940 if (optimized_type
== tls::TLSOPT_NONE
)
1942 // For the R_386_TLS_IE relocation, we need to create a
1943 // dynamic relocation when building a shared library.
1944 if (r_type
== elfcpp::R_386_TLS_IE
1945 && parameters
->options().shared())
1947 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1949 = elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1950 rel_dyn
->add_local_relative(object
, r_sym
,
1951 elfcpp::R_386_RELATIVE
,
1952 output_section
, data_shndx
,
1953 reloc
.get_r_offset());
1955 // Create a GOT entry for the tp-relative offset.
1956 Output_data_got
<32, false>* got
1957 = target
->got_section(symtab
, layout
);
1958 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1959 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1960 ? elfcpp::R_386_TLS_TPOFF32
1961 : elfcpp::R_386_TLS_TPOFF
);
1962 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1963 ? GOT_TYPE_TLS_OFFSET
1964 : GOT_TYPE_TLS_NOFFSET
);
1965 got
->add_local_with_rel(object
, r_sym
, got_type
,
1966 target
->rel_dyn_section(layout
),
1969 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1970 unsupported_reloc_local(object
, r_type
);
1973 case elfcpp::R_386_TLS_LE
: // Local-exec
1974 case elfcpp::R_386_TLS_LE_32
:
1975 layout
->set_has_static_tls();
1976 if (output_is_shared
)
1978 // We need to create a dynamic relocation.
1979 gold_assert(lsym
.get_st_type() != elfcpp::STT_SECTION
);
1980 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1981 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
1982 ? elfcpp::R_386_TLS_TPOFF32
1983 : elfcpp::R_386_TLS_TPOFF
);
1984 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1985 rel_dyn
->add_local(object
, r_sym
, dyn_r_type
, output_section
,
1986 data_shndx
, reloc
.get_r_offset());
1996 case elfcpp::R_386_32PLT
:
1997 case elfcpp::R_386_TLS_GD_32
:
1998 case elfcpp::R_386_TLS_GD_PUSH
:
1999 case elfcpp::R_386_TLS_GD_CALL
:
2000 case elfcpp::R_386_TLS_GD_POP
:
2001 case elfcpp::R_386_TLS_LDM_32
:
2002 case elfcpp::R_386_TLS_LDM_PUSH
:
2003 case elfcpp::R_386_TLS_LDM_CALL
:
2004 case elfcpp::R_386_TLS_LDM_POP
:
2005 case elfcpp::R_386_USED_BY_INTEL_200
:
2007 unsupported_reloc_local(object
, r_type
);
2012 // Report an unsupported relocation against a global symbol.
2015 Target_i386::Scan::unsupported_reloc_global(
2016 Sized_relobj_file
<32, false>* object
,
2017 unsigned int r_type
,
2020 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
2021 object
->name().c_str(), r_type
, gsym
->demangled_name().c_str());
2025 Target_i386::Scan::possible_function_pointer_reloc(unsigned int r_type
)
2029 case elfcpp::R_386_32
:
2030 case elfcpp::R_386_16
:
2031 case elfcpp::R_386_8
:
2032 case elfcpp::R_386_GOTOFF
:
2033 case elfcpp::R_386_GOT32
:
2044 Target_i386::Scan::local_reloc_may_be_function_pointer(
2048 Sized_relobj_file
<32, false>* ,
2051 const elfcpp::Rel
<32, false>& ,
2052 unsigned int r_type
,
2053 const elfcpp::Sym
<32, false>&)
2055 return possible_function_pointer_reloc(r_type
);
2059 Target_i386::Scan::global_reloc_may_be_function_pointer(
2063 Sized_relobj_file
<32, false>* ,
2066 const elfcpp::Rel
<32, false>& ,
2067 unsigned int r_type
,
2070 return possible_function_pointer_reloc(r_type
);
2073 // Scan a relocation for a global symbol.
2076 Target_i386::Scan::global(Symbol_table
* symtab
,
2078 Target_i386
* target
,
2079 Sized_relobj_file
<32, false>* object
,
2080 unsigned int data_shndx
,
2081 Output_section
* output_section
,
2082 const elfcpp::Rel
<32, false>& reloc
,
2083 unsigned int r_type
,
2086 // A STT_GNU_IFUNC symbol may require a PLT entry.
2087 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
2088 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
2089 target
->make_plt_entry(symtab
, layout
, gsym
);
2093 case elfcpp::R_386_NONE
:
2094 case elfcpp::R_386_GNU_VTINHERIT
:
2095 case elfcpp::R_386_GNU_VTENTRY
:
2098 case elfcpp::R_386_32
:
2099 case elfcpp::R_386_16
:
2100 case elfcpp::R_386_8
:
2102 // Make a PLT entry if necessary.
2103 if (gsym
->needs_plt_entry())
2105 target
->make_plt_entry(symtab
, layout
, gsym
);
2106 // Since this is not a PC-relative relocation, we may be
2107 // taking the address of a function. In that case we need to
2108 // set the entry in the dynamic symbol table to the address of
2110 if (gsym
->is_from_dynobj() && !parameters
->options().shared())
2111 gsym
->set_needs_dynsym_value();
2113 // Make a dynamic relocation if necessary.
2114 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
2116 if (gsym
->may_need_copy_reloc())
2118 target
->copy_reloc(symtab
, layout
, object
,
2119 data_shndx
, output_section
, gsym
, reloc
);
2121 else if (r_type
== elfcpp::R_386_32
2122 && gsym
->type() == elfcpp::STT_GNU_IFUNC
2123 && gsym
->can_use_relative_reloc(false)
2124 && !gsym
->is_from_dynobj()
2125 && !gsym
->is_undefined()
2126 && !gsym
->is_preemptible())
2128 // Use an IRELATIVE reloc for a locally defined
2129 // STT_GNU_IFUNC symbol. This makes a function
2130 // address in a PIE executable match the address in a
2131 // shared library that it links against.
2132 Reloc_section
* rel_dyn
= target
->rel_irelative_section(layout
);
2133 rel_dyn
->add_symbolless_global_addend(gsym
,
2134 elfcpp::R_386_IRELATIVE
,
2137 reloc
.get_r_offset());
2139 else if (r_type
== elfcpp::R_386_32
2140 && gsym
->can_use_relative_reloc(false))
2142 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2143 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
2144 output_section
, object
,
2145 data_shndx
, reloc
.get_r_offset());
2149 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2150 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
2151 data_shndx
, reloc
.get_r_offset());
2157 case elfcpp::R_386_PC32
:
2158 case elfcpp::R_386_PC16
:
2159 case elfcpp::R_386_PC8
:
2161 // Make a PLT entry if necessary.
2162 if (gsym
->needs_plt_entry())
2164 // These relocations are used for function calls only in
2165 // non-PIC code. For a 32-bit relocation in a shared library,
2166 // we'll need a text relocation anyway, so we can skip the
2167 // PLT entry and let the dynamic linker bind the call directly
2168 // to the target. For smaller relocations, we should use a
2169 // PLT entry to ensure that the call can reach.
2170 if (!parameters
->options().shared()
2171 || r_type
!= elfcpp::R_386_PC32
)
2172 target
->make_plt_entry(symtab
, layout
, gsym
);
2174 // Make a dynamic relocation if necessary.
2175 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
2177 if (gsym
->may_need_copy_reloc())
2179 target
->copy_reloc(symtab
, layout
, object
,
2180 data_shndx
, output_section
, gsym
, reloc
);
2184 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2185 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
2186 data_shndx
, reloc
.get_r_offset());
2192 case elfcpp::R_386_GOT32
:
2194 // The symbol requires a GOT entry.
2195 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
2196 if (gsym
->final_value_is_known())
2198 // For a STT_GNU_IFUNC symbol we want the PLT address.
2199 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
)
2200 got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
2202 got
->add_global(gsym
, GOT_TYPE_STANDARD
);
2206 // If this symbol is not fully resolved, we need to add a
2207 // GOT entry with a dynamic relocation.
2208 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2210 // Use a GLOB_DAT rather than a RELATIVE reloc if:
2212 // 1) The symbol may be defined in some other module.
2214 // 2) We are building a shared library and this is a
2215 // protected symbol; using GLOB_DAT means that the dynamic
2216 // linker can use the address of the PLT in the main
2217 // executable when appropriate so that function address
2218 // comparisons work.
2220 // 3) This is a STT_GNU_IFUNC symbol in position dependent
2221 // code, again so that function address comparisons work.
2222 if (gsym
->is_from_dynobj()
2223 || gsym
->is_undefined()
2224 || gsym
->is_preemptible()
2225 || (gsym
->visibility() == elfcpp::STV_PROTECTED
2226 && parameters
->options().shared())
2227 || (gsym
->type() == elfcpp::STT_GNU_IFUNC
2228 && parameters
->options().output_is_position_independent()))
2229 got
->add_global_with_rel(gsym
, GOT_TYPE_STANDARD
,
2230 rel_dyn
, elfcpp::R_386_GLOB_DAT
);
2233 // For a STT_GNU_IFUNC symbol we want to write the PLT
2234 // offset into the GOT, so that function pointer
2235 // comparisons work correctly.
2237 if (gsym
->type() != elfcpp::STT_GNU_IFUNC
)
2238 is_new
= got
->add_global(gsym
, GOT_TYPE_STANDARD
);
2241 is_new
= got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
2242 // Tell the dynamic linker to use the PLT address
2243 // when resolving relocations.
2244 if (gsym
->is_from_dynobj()
2245 && !parameters
->options().shared())
2246 gsym
->set_needs_dynsym_value();
2250 unsigned int got_off
= gsym
->got_offset(GOT_TYPE_STANDARD
);
2251 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
2259 case elfcpp::R_386_PLT32
:
2260 // If the symbol is fully resolved, this is just a PC32 reloc.
2261 // Otherwise we need a PLT entry.
2262 if (gsym
->final_value_is_known())
2264 // If building a shared library, we can also skip the PLT entry
2265 // if the symbol is defined in the output file and is protected
2267 if (gsym
->is_defined()
2268 && !gsym
->is_from_dynobj()
2269 && !gsym
->is_preemptible())
2271 target
->make_plt_entry(symtab
, layout
, gsym
);
2274 case elfcpp::R_386_GOTOFF
:
2275 case elfcpp::R_386_GOTPC
:
2276 // We need a GOT section.
2277 target
->got_section(symtab
, layout
);
2280 // These are relocations which should only be seen by the
2281 // dynamic linker, and should never be seen here.
2282 case elfcpp::R_386_COPY
:
2283 case elfcpp::R_386_GLOB_DAT
:
2284 case elfcpp::R_386_JUMP_SLOT
:
2285 case elfcpp::R_386_RELATIVE
:
2286 case elfcpp::R_386_IRELATIVE
:
2287 case elfcpp::R_386_TLS_TPOFF
:
2288 case elfcpp::R_386_TLS_DTPMOD32
:
2289 case elfcpp::R_386_TLS_DTPOFF32
:
2290 case elfcpp::R_386_TLS_TPOFF32
:
2291 case elfcpp::R_386_TLS_DESC
:
2292 gold_error(_("%s: unexpected reloc %u in object file"),
2293 object
->name().c_str(), r_type
);
2296 // These are initial tls relocs, which are expected when
2298 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2299 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2300 case elfcpp::R_386_TLS_DESC_CALL
:
2301 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2302 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2303 case elfcpp::R_386_TLS_IE
: // Initial-exec
2304 case elfcpp::R_386_TLS_IE_32
:
2305 case elfcpp::R_386_TLS_GOTIE
:
2306 case elfcpp::R_386_TLS_LE
: // Local-exec
2307 case elfcpp::R_386_TLS_LE_32
:
2309 const bool is_final
= gsym
->final_value_is_known();
2310 const tls::Tls_optimization optimized_type
2311 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
2314 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2315 if (optimized_type
== tls::TLSOPT_NONE
)
2317 // Create a pair of GOT entries for the module index and
2318 // dtv-relative offset.
2319 Output_data_got
<32, false>* got
2320 = target
->got_section(symtab
, layout
);
2321 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_PAIR
,
2322 target
->rel_dyn_section(layout
),
2323 elfcpp::R_386_TLS_DTPMOD32
,
2324 elfcpp::R_386_TLS_DTPOFF32
);
2326 else if (optimized_type
== tls::TLSOPT_TO_IE
)
2328 // Create a GOT entry for the tp-relative offset.
2329 Output_data_got
<32, false>* got
2330 = target
->got_section(symtab
, layout
);
2331 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
2332 target
->rel_dyn_section(layout
),
2333 elfcpp::R_386_TLS_TPOFF
);
2335 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2336 unsupported_reloc_global(object
, r_type
, gsym
);
2339 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (~oliva url)
2340 target
->define_tls_base_symbol(symtab
, layout
);
2341 if (optimized_type
== tls::TLSOPT_NONE
)
2343 // Create a double GOT entry with an R_386_TLS_DESC
2344 // reloc. The R_386_TLS_DESC reloc is resolved
2345 // lazily, so the GOT entry needs to be in an area in
2346 // .got.plt, not .got. Call got_section to make sure
2347 // the section has been created.
2348 target
->got_section(symtab
, layout
);
2349 Output_data_got
<32, false>* got
= target
->got_tlsdesc_section();
2350 Reloc_section
* rt
= target
->rel_tls_desc_section(layout
);
2351 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_DESC
, rt
,
2352 elfcpp::R_386_TLS_DESC
, 0);
2354 else if (optimized_type
== tls::TLSOPT_TO_IE
)
2356 // Create a GOT entry for the tp-relative offset.
2357 Output_data_got
<32, false>* got
2358 = target
->got_section(symtab
, layout
);
2359 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
2360 target
->rel_dyn_section(layout
),
2361 elfcpp::R_386_TLS_TPOFF
);
2363 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2364 unsupported_reloc_global(object
, r_type
, gsym
);
2367 case elfcpp::R_386_TLS_DESC_CALL
:
2370 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2371 if (optimized_type
== tls::TLSOPT_NONE
)
2373 // Create a GOT entry for the module index.
2374 target
->got_mod_index_entry(symtab
, layout
, object
);
2376 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2377 unsupported_reloc_global(object
, r_type
, gsym
);
2380 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2383 case elfcpp::R_386_TLS_IE
: // Initial-exec
2384 case elfcpp::R_386_TLS_IE_32
:
2385 case elfcpp::R_386_TLS_GOTIE
:
2386 layout
->set_has_static_tls();
2387 if (optimized_type
== tls::TLSOPT_NONE
)
2389 // For the R_386_TLS_IE relocation, we need to create a
2390 // dynamic relocation when building a shared library.
2391 if (r_type
== elfcpp::R_386_TLS_IE
2392 && parameters
->options().shared())
2394 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2395 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
2396 output_section
, object
,
2398 reloc
.get_r_offset());
2400 // Create a GOT entry for the tp-relative offset.
2401 Output_data_got
<32, false>* got
2402 = target
->got_section(symtab
, layout
);
2403 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2404 ? elfcpp::R_386_TLS_TPOFF32
2405 : elfcpp::R_386_TLS_TPOFF
);
2406 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2407 ? GOT_TYPE_TLS_OFFSET
2408 : GOT_TYPE_TLS_NOFFSET
);
2409 got
->add_global_with_rel(gsym
, got_type
,
2410 target
->rel_dyn_section(layout
),
2413 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2414 unsupported_reloc_global(object
, r_type
, gsym
);
2417 case elfcpp::R_386_TLS_LE
: // Local-exec
2418 case elfcpp::R_386_TLS_LE_32
:
2419 layout
->set_has_static_tls();
2420 if (parameters
->options().shared())
2422 // We need to create a dynamic relocation.
2423 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
2424 ? elfcpp::R_386_TLS_TPOFF32
2425 : elfcpp::R_386_TLS_TPOFF
);
2426 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2427 rel_dyn
->add_global(gsym
, dyn_r_type
, output_section
, object
,
2428 data_shndx
, reloc
.get_r_offset());
2438 case elfcpp::R_386_32PLT
:
2439 case elfcpp::R_386_TLS_GD_32
:
2440 case elfcpp::R_386_TLS_GD_PUSH
:
2441 case elfcpp::R_386_TLS_GD_CALL
:
2442 case elfcpp::R_386_TLS_GD_POP
:
2443 case elfcpp::R_386_TLS_LDM_32
:
2444 case elfcpp::R_386_TLS_LDM_PUSH
:
2445 case elfcpp::R_386_TLS_LDM_CALL
:
2446 case elfcpp::R_386_TLS_LDM_POP
:
2447 case elfcpp::R_386_USED_BY_INTEL_200
:
2449 unsupported_reloc_global(object
, r_type
, gsym
);
2454 // Process relocations for gc.
2457 Target_i386::gc_process_relocs(Symbol_table
* symtab
,
2459 Sized_relobj_file
<32, false>* object
,
2460 unsigned int data_shndx
,
2462 const unsigned char* prelocs
,
2464 Output_section
* output_section
,
2465 bool needs_special_offset_handling
,
2466 size_t local_symbol_count
,
2467 const unsigned char* plocal_symbols
)
2469 gold::gc_process_relocs
<32, false, Target_i386
, elfcpp::SHT_REL
,
2471 Target_i386::Relocatable_size_for_reloc
>(
2480 needs_special_offset_handling
,
2485 // Scan relocations for a section.
2488 Target_i386::scan_relocs(Symbol_table
* symtab
,
2490 Sized_relobj_file
<32, false>* object
,
2491 unsigned int data_shndx
,
2492 unsigned int sh_type
,
2493 const unsigned char* prelocs
,
2495 Output_section
* output_section
,
2496 bool needs_special_offset_handling
,
2497 size_t local_symbol_count
,
2498 const unsigned char* plocal_symbols
)
2500 if (sh_type
== elfcpp::SHT_RELA
)
2502 gold_error(_("%s: unsupported RELA reloc section"),
2503 object
->name().c_str());
2507 gold::scan_relocs
<32, false, Target_i386
, elfcpp::SHT_REL
,
2517 needs_special_offset_handling
,
2522 // Finalize the sections.
2525 Target_i386::do_finalize_sections(
2527 const Input_objects
*,
2528 Symbol_table
* symtab
)
2530 const Reloc_section
* rel_plt
= (this->plt_
== NULL
2532 : this->plt_
->rel_plt());
2533 layout
->add_target_dynamic_tags(true, this->got_plt_
, rel_plt
,
2534 this->rel_dyn_
, true, false);
2536 // Emit any relocs we saved in an attempt to avoid generating COPY
2538 if (this->copy_relocs_
.any_saved_relocs())
2539 this->copy_relocs_
.emit(this->rel_dyn_section(layout
));
2541 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
2542 // the .got.plt section.
2543 Symbol
* sym
= this->global_offset_table_
;
2546 uint32_t data_size
= this->got_plt_
->current_data_size();
2547 symtab
->get_sized_symbol
<32>(sym
)->set_symsize(data_size
);
2550 if (parameters
->doing_static_link()
2551 && (this->plt_
== NULL
|| !this->plt_
->has_irelative_section()))
2553 // If linking statically, make sure that the __rel_iplt symbols
2554 // were defined if necessary, even if we didn't create a PLT.
2555 static const Define_symbol_in_segment syms
[] =
2558 "__rel_iplt_start", // name
2559 elfcpp::PT_LOAD
, // segment_type
2560 elfcpp::PF_W
, // segment_flags_set
2561 elfcpp::PF(0), // segment_flags_clear
2564 elfcpp::STT_NOTYPE
, // type
2565 elfcpp::STB_GLOBAL
, // binding
2566 elfcpp::STV_HIDDEN
, // visibility
2568 Symbol::SEGMENT_START
, // offset_from_base
2572 "__rel_iplt_end", // name
2573 elfcpp::PT_LOAD
, // segment_type
2574 elfcpp::PF_W
, // segment_flags_set
2575 elfcpp::PF(0), // segment_flags_clear
2578 elfcpp::STT_NOTYPE
, // type
2579 elfcpp::STB_GLOBAL
, // binding
2580 elfcpp::STV_HIDDEN
, // visibility
2582 Symbol::SEGMENT_START
, // offset_from_base
2587 symtab
->define_symbols(layout
, 2, syms
,
2588 layout
->script_options()->saw_sections_clause());
2592 // Return whether a direct absolute static relocation needs to be applied.
2593 // In cases where Scan::local() or Scan::global() has created
2594 // a dynamic relocation other than R_386_RELATIVE, the addend
2595 // of the relocation is carried in the data, and we must not
2596 // apply the static relocation.
2599 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
2600 unsigned int r_type
,
2602 Output_section
* output_section
)
2604 // If the output section is not allocated, then we didn't call
2605 // scan_relocs, we didn't create a dynamic reloc, and we must apply
2607 if ((output_section
->flags() & elfcpp::SHF_ALLOC
) == 0)
2610 int ref_flags
= Scan::get_reference_flags(r_type
);
2612 // For local symbols, we will have created a non-RELATIVE dynamic
2613 // relocation only if (a) the output is position independent,
2614 // (b) the relocation is absolute (not pc- or segment-relative), and
2615 // (c) the relocation is not 32 bits wide.
2617 return !(parameters
->options().output_is_position_independent()
2618 && (ref_flags
& Symbol::ABSOLUTE_REF
)
2621 // For global symbols, we use the same helper routines used in the
2622 // scan pass. If we did not create a dynamic relocation, or if we
2623 // created a RELATIVE dynamic relocation, we should apply the static
2625 bool has_dyn
= gsym
->needs_dynamic_reloc(ref_flags
);
2626 bool is_rel
= (ref_flags
& Symbol::ABSOLUTE_REF
)
2627 && gsym
->can_use_relative_reloc(ref_flags
2628 & Symbol::FUNCTION_CALL
);
2629 return !has_dyn
|| is_rel
;
2632 // Perform a relocation.
2635 Target_i386::Relocate::relocate(const Relocate_info
<32, false>* relinfo
,
2636 Target_i386
* target
,
2637 Output_section
* output_section
,
2639 const elfcpp::Rel
<32, false>& rel
,
2640 unsigned int r_type
,
2641 const Sized_symbol
<32>* gsym
,
2642 const Symbol_value
<32>* psymval
,
2643 unsigned char* view
,
2644 elfcpp::Elf_types
<32>::Elf_Addr address
,
2645 section_size_type view_size
)
2647 if (this->skip_call_tls_get_addr_
)
2649 if ((r_type
!= elfcpp::R_386_PLT32
2650 && r_type
!= elfcpp::R_386_PC32
)
2652 || strcmp(gsym
->name(), "___tls_get_addr") != 0)
2653 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2654 _("missing expected TLS relocation"));
2657 this->skip_call_tls_get_addr_
= false;
2665 const Sized_relobj_file
<32, false>* object
= relinfo
->object
;
2667 // Pick the value to use for symbols defined in shared objects.
2668 Symbol_value
<32> symval
;
2670 && gsym
->type() == elfcpp::STT_GNU_IFUNC
2671 && r_type
== elfcpp::R_386_32
2672 && gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
))
2673 && gsym
->can_use_relative_reloc(false)
2674 && !gsym
->is_from_dynobj()
2675 && !gsym
->is_undefined()
2676 && !gsym
->is_preemptible())
2678 // In this case we are generating a R_386_IRELATIVE reloc. We
2679 // want to use the real value of the symbol, not the PLT offset.
2681 else if (gsym
!= NULL
2682 && gsym
->use_plt_offset(Scan::get_reference_flags(r_type
)))
2684 symval
.set_output_value(target
->plt_address_for_global(gsym
));
2687 else if (gsym
== NULL
&& psymval
->is_ifunc_symbol())
2689 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2690 if (object
->local_has_plt_offset(r_sym
))
2692 symval
.set_output_value(target
->plt_address_for_local(object
, r_sym
));
2697 // Get the GOT offset if needed.
2698 // The GOT pointer points to the end of the GOT section.
2699 // We need to subtract the size of the GOT section to get
2700 // the actual offset to use in the relocation.
2701 bool have_got_offset
= false;
2702 unsigned int got_offset
= 0;
2705 case elfcpp::R_386_GOT32
:
2708 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
2709 got_offset
= (gsym
->got_offset(GOT_TYPE_STANDARD
)
2710 - target
->got_size());
2714 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2715 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
2716 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
2717 - target
->got_size());
2719 have_got_offset
= true;
2728 case elfcpp::R_386_NONE
:
2729 case elfcpp::R_386_GNU_VTINHERIT
:
2730 case elfcpp::R_386_GNU_VTENTRY
:
2733 case elfcpp::R_386_32
:
2734 if (should_apply_static_reloc(gsym
, r_type
, true, output_section
))
2735 Relocate_functions
<32, false>::rel32(view
, object
, psymval
);
2738 case elfcpp::R_386_PC32
:
2739 if (should_apply_static_reloc(gsym
, r_type
, true, output_section
))
2740 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
2743 case elfcpp::R_386_16
:
2744 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2745 Relocate_functions
<32, false>::rel16(view
, object
, psymval
);
2748 case elfcpp::R_386_PC16
:
2749 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2750 Relocate_functions
<32, false>::pcrel16(view
, object
, psymval
, address
);
2753 case elfcpp::R_386_8
:
2754 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2755 Relocate_functions
<32, false>::rel8(view
, object
, psymval
);
2758 case elfcpp::R_386_PC8
:
2759 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2760 Relocate_functions
<32, false>::pcrel8(view
, object
, psymval
, address
);
2763 case elfcpp::R_386_PLT32
:
2764 gold_assert(gsym
== NULL
2765 || gsym
->has_plt_offset()
2766 || gsym
->final_value_is_known()
2767 || (gsym
->is_defined()
2768 && !gsym
->is_from_dynobj()
2769 && !gsym
->is_preemptible()));
2770 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
2773 case elfcpp::R_386_GOT32
:
2774 gold_assert(have_got_offset
);
2775 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2778 case elfcpp::R_386_GOTOFF
:
2780 elfcpp::Elf_types
<32>::Elf_Addr value
;
2781 value
= (psymval
->value(object
, 0)
2782 - target
->got_plt_section()->address());
2783 Relocate_functions
<32, false>::rel32(view
, value
);
2787 case elfcpp::R_386_GOTPC
:
2789 elfcpp::Elf_types
<32>::Elf_Addr value
;
2790 value
= target
->got_plt_section()->address();
2791 Relocate_functions
<32, false>::pcrel32(view
, value
, address
);
2795 case elfcpp::R_386_COPY
:
2796 case elfcpp::R_386_GLOB_DAT
:
2797 case elfcpp::R_386_JUMP_SLOT
:
2798 case elfcpp::R_386_RELATIVE
:
2799 case elfcpp::R_386_IRELATIVE
:
2800 // These are outstanding tls relocs, which are unexpected when
2802 case elfcpp::R_386_TLS_TPOFF
:
2803 case elfcpp::R_386_TLS_DTPMOD32
:
2804 case elfcpp::R_386_TLS_DTPOFF32
:
2805 case elfcpp::R_386_TLS_TPOFF32
:
2806 case elfcpp::R_386_TLS_DESC
:
2807 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2808 _("unexpected reloc %u in object file"),
2812 // These are initial tls relocs, which are expected when
2814 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2815 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2816 case elfcpp::R_386_TLS_DESC_CALL
:
2817 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2818 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2819 case elfcpp::R_386_TLS_IE
: // Initial-exec
2820 case elfcpp::R_386_TLS_IE_32
:
2821 case elfcpp::R_386_TLS_GOTIE
:
2822 case elfcpp::R_386_TLS_LE
: // Local-exec
2823 case elfcpp::R_386_TLS_LE_32
:
2824 this->relocate_tls(relinfo
, target
, relnum
, rel
, r_type
, gsym
, psymval
,
2825 view
, address
, view_size
);
2828 case elfcpp::R_386_32PLT
:
2829 case elfcpp::R_386_TLS_GD_32
:
2830 case elfcpp::R_386_TLS_GD_PUSH
:
2831 case elfcpp::R_386_TLS_GD_CALL
:
2832 case elfcpp::R_386_TLS_GD_POP
:
2833 case elfcpp::R_386_TLS_LDM_32
:
2834 case elfcpp::R_386_TLS_LDM_PUSH
:
2835 case elfcpp::R_386_TLS_LDM_CALL
:
2836 case elfcpp::R_386_TLS_LDM_POP
:
2837 case elfcpp::R_386_USED_BY_INTEL_200
:
2839 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2840 _("unsupported reloc %u"),
2848 // Perform a TLS relocation.
2851 Target_i386::Relocate::relocate_tls(const Relocate_info
<32, false>* relinfo
,
2852 Target_i386
* target
,
2854 const elfcpp::Rel
<32, false>& rel
,
2855 unsigned int r_type
,
2856 const Sized_symbol
<32>* gsym
,
2857 const Symbol_value
<32>* psymval
,
2858 unsigned char* view
,
2859 elfcpp::Elf_types
<32>::Elf_Addr
,
2860 section_size_type view_size
)
2862 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
2864 const Sized_relobj_file
<32, false>* object
= relinfo
->object
;
2866 elfcpp::Elf_types
<32>::Elf_Addr value
= psymval
->value(object
, 0);
2868 const bool is_final
= (gsym
== NULL
2869 ? !parameters
->options().shared()
2870 : gsym
->final_value_is_known());
2871 const tls::Tls_optimization optimized_type
2872 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
2875 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2876 if (optimized_type
== tls::TLSOPT_TO_LE
)
2878 if (tls_segment
== NULL
)
2880 gold_assert(parameters
->errors()->error_count() > 0
2881 || issue_undefined_symbol_error(gsym
));
2884 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
2885 rel
, r_type
, value
, view
,
2891 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
2892 ? GOT_TYPE_TLS_NOFFSET
2893 : GOT_TYPE_TLS_PAIR
);
2894 unsigned int got_offset
;
2897 gold_assert(gsym
->has_got_offset(got_type
));
2898 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
2902 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2903 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
2904 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
2905 - target
->got_size());
2907 if (optimized_type
== tls::TLSOPT_TO_IE
)
2909 this->tls_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
2910 got_offset
, view
, view_size
);
2913 else if (optimized_type
== tls::TLSOPT_NONE
)
2915 // Relocate the field with the offset of the pair of GOT
2917 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2921 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2922 _("unsupported reloc %u"),
2926 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2927 case elfcpp::R_386_TLS_DESC_CALL
:
2928 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
2929 if (optimized_type
== tls::TLSOPT_TO_LE
)
2931 if (tls_segment
== NULL
)
2933 gold_assert(parameters
->errors()->error_count() > 0
2934 || issue_undefined_symbol_error(gsym
));
2937 this->tls_desc_gd_to_le(relinfo
, relnum
, tls_segment
,
2938 rel
, r_type
, value
, view
,
2944 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
2945 ? GOT_TYPE_TLS_NOFFSET
2946 : GOT_TYPE_TLS_DESC
);
2947 unsigned int got_offset
= 0;
2948 if (r_type
== elfcpp::R_386_TLS_GOTDESC
2949 && optimized_type
== tls::TLSOPT_NONE
)
2951 // We created GOT entries in the .got.tlsdesc portion of
2952 // the .got.plt section, but the offset stored in the
2953 // symbol is the offset within .got.tlsdesc.
2954 got_offset
= (target
->got_size()
2955 + target
->got_plt_section()->data_size());
2959 gold_assert(gsym
->has_got_offset(got_type
));
2960 got_offset
+= gsym
->got_offset(got_type
) - target
->got_size();
2964 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2965 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
2966 got_offset
+= (object
->local_got_offset(r_sym
, got_type
)
2967 - target
->got_size());
2969 if (optimized_type
== tls::TLSOPT_TO_IE
)
2971 if (tls_segment
== NULL
)
2973 gold_assert(parameters
->errors()->error_count() > 0
2974 || issue_undefined_symbol_error(gsym
));
2977 this->tls_desc_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
2978 got_offset
, view
, view_size
);
2981 else if (optimized_type
== tls::TLSOPT_NONE
)
2983 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
2985 // Relocate the field with the offset of the pair of GOT
2987 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2992 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2993 _("unsupported reloc %u"),
2997 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2998 if (this->local_dynamic_type_
== LOCAL_DYNAMIC_SUN
)
3000 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3001 _("both SUN and GNU model "
3002 "TLS relocations"));
3005 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
3006 if (optimized_type
== tls::TLSOPT_TO_LE
)
3008 if (tls_segment
== NULL
)
3010 gold_assert(parameters
->errors()->error_count() > 0
3011 || issue_undefined_symbol_error(gsym
));
3014 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rel
, r_type
,
3015 value
, view
, view_size
);
3018 else if (optimized_type
== tls::TLSOPT_NONE
)
3020 // Relocate the field with the offset of the GOT entry for
3021 // the module index.
3022 unsigned int got_offset
;
3023 got_offset
= (target
->got_mod_index_entry(NULL
, NULL
, NULL
)
3024 - target
->got_size());
3025 Relocate_functions
<32, false>::rel32(view
, got_offset
);
3028 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3029 _("unsupported reloc %u"),
3033 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
3034 if (optimized_type
== tls::TLSOPT_TO_LE
)
3036 // This reloc can appear in debugging sections, in which
3037 // case we must not convert to local-exec. We decide what
3038 // to do based on whether the section is marked as
3039 // containing executable code. That is what the GNU linker
3041 elfcpp::Shdr
<32, false> shdr(relinfo
->data_shdr
);
3042 if ((shdr
.get_sh_flags() & elfcpp::SHF_EXECINSTR
) != 0)
3044 if (tls_segment
== NULL
)
3046 gold_assert(parameters
->errors()->error_count() > 0
3047 || issue_undefined_symbol_error(gsym
));
3050 value
-= tls_segment
->memsz();
3053 Relocate_functions
<32, false>::rel32(view
, value
);
3056 case elfcpp::R_386_TLS_IE
: // Initial-exec
3057 case elfcpp::R_386_TLS_GOTIE
:
3058 case elfcpp::R_386_TLS_IE_32
:
3059 if (optimized_type
== tls::TLSOPT_TO_LE
)
3061 if (tls_segment
== NULL
)
3063 gold_assert(parameters
->errors()->error_count() > 0
3064 || issue_undefined_symbol_error(gsym
));
3067 Target_i386::Relocate::tls_ie_to_le(relinfo
, relnum
, tls_segment
,
3068 rel
, r_type
, value
, view
,
3072 else if (optimized_type
== tls::TLSOPT_NONE
)
3074 // Relocate the field with the offset of the GOT entry for
3075 // the tp-relative offset of the symbol.
3076 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
3077 ? GOT_TYPE_TLS_OFFSET
3078 : GOT_TYPE_TLS_NOFFSET
);
3079 unsigned int got_offset
;
3082 gold_assert(gsym
->has_got_offset(got_type
));
3083 got_offset
= gsym
->got_offset(got_type
);
3087 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
3088 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
3089 got_offset
= object
->local_got_offset(r_sym
, got_type
);
3091 // For the R_386_TLS_IE relocation, we need to apply the
3092 // absolute address of the GOT entry.
3093 if (r_type
== elfcpp::R_386_TLS_IE
)
3094 got_offset
+= target
->got_plt_section()->address();
3095 // All GOT offsets are relative to the end of the GOT.
3096 got_offset
-= target
->got_size();
3097 Relocate_functions
<32, false>::rel32(view
, got_offset
);
3100 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3101 _("unsupported reloc %u"),
3105 case elfcpp::R_386_TLS_LE
: // Local-exec
3106 // If we're creating a shared library, a dynamic relocation will
3107 // have been created for this location, so do not apply it now.
3108 if (!parameters
->options().shared())
3110 if (tls_segment
== NULL
)
3112 gold_assert(parameters
->errors()->error_count() > 0
3113 || issue_undefined_symbol_error(gsym
));
3116 value
-= tls_segment
->memsz();
3117 Relocate_functions
<32, false>::rel32(view
, value
);
3121 case elfcpp::R_386_TLS_LE_32
:
3122 // If we're creating a shared library, a dynamic relocation will
3123 // have been created for this location, so do not apply it now.
3124 if (!parameters
->options().shared())
3126 if (tls_segment
== NULL
)
3128 gold_assert(parameters
->errors()->error_count() > 0
3129 || issue_undefined_symbol_error(gsym
));
3132 value
= tls_segment
->memsz() - value
;
3133 Relocate_functions
<32, false>::rel32(view
, value
);
3139 // Do a relocation in which we convert a TLS General-Dynamic to a
3143 Target_i386::Relocate::tls_gd_to_le(const Relocate_info
<32, false>* relinfo
,
3145 Output_segment
* tls_segment
,
3146 const elfcpp::Rel
<32, false>& rel
,
3148 elfcpp::Elf_types
<32>::Elf_Addr value
,
3149 unsigned char* view
,
3150 section_size_type view_size
)
3152 // leal foo(,%reg,1),%eax; call ___tls_get_addr
3153 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
3154 // leal foo(%reg),%eax; call ___tls_get_addr
3155 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
3157 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3158 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
3160 unsigned char op1
= view
[-1];
3161 unsigned char op2
= view
[-2];
3163 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3164 op2
== 0x8d || op2
== 0x04);
3165 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
3171 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
3172 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
3173 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3174 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
3175 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3179 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3180 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
3181 if (rel
.get_r_offset() + 9 < view_size
3184 // There is a trailing nop. Use the size byte subl.
3185 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3190 // Use the five byte subl.
3191 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
3195 value
= tls_segment
->memsz() - value
;
3196 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
3198 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3200 this->skip_call_tls_get_addr_
= true;
3203 // Do a relocation in which we convert a TLS General-Dynamic to an
3207 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info
<32, false>* relinfo
,
3210 const elfcpp::Rel
<32, false>& rel
,
3212 elfcpp::Elf_types
<32>::Elf_Addr value
,
3213 unsigned char* view
,
3214 section_size_type view_size
)
3216 // leal foo(,%ebx,1),%eax; call ___tls_get_addr
3217 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
3219 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3220 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
3222 unsigned char op1
= view
[-1];
3223 unsigned char op2
= view
[-2];
3225 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3226 op2
== 0x8d || op2
== 0x04);
3227 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
3231 // FIXME: For now, support only the first (SIB) form.
3232 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), op2
== 0x04);
3236 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
3237 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
3238 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3239 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
3240 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
3244 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3245 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
3246 if (rel
.get_r_offset() + 9 < view_size
3249 // FIXME: This is not the right instruction sequence.
3250 // There is a trailing nop. Use the size byte subl.
3251 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3256 // FIXME: This is not the right instruction sequence.
3257 // Use the five byte subl.
3258 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
3262 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
3264 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3266 this->skip_call_tls_get_addr_
= true;
3269 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3270 // General-Dynamic to a Local-Exec.
3273 Target_i386::Relocate::tls_desc_gd_to_le(
3274 const Relocate_info
<32, false>* relinfo
,
3276 Output_segment
* tls_segment
,
3277 const elfcpp::Rel
<32, false>& rel
,
3278 unsigned int r_type
,
3279 elfcpp::Elf_types
<32>::Elf_Addr value
,
3280 unsigned char* view
,
3281 section_size_type view_size
)
3283 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
3285 // leal foo@TLSDESC(%ebx), %eax
3286 // ==> leal foo@NTPOFF, %eax
3287 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3288 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3289 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3290 view
[-2] == 0x8d && view
[-1] == 0x83);
3292 value
-= tls_segment
->memsz();
3293 Relocate_functions
<32, false>::rel32(view
, value
);
3297 // call *foo@TLSCALL(%eax)
3299 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
3300 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
3301 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3302 view
[0] == 0xff && view
[1] == 0x10);
3308 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3309 // General-Dynamic to an Initial-Exec.
3312 Target_i386::Relocate::tls_desc_gd_to_ie(
3313 const Relocate_info
<32, false>* relinfo
,
3316 const elfcpp::Rel
<32, false>& rel
,
3317 unsigned int r_type
,
3318 elfcpp::Elf_types
<32>::Elf_Addr value
,
3319 unsigned char* view
,
3320 section_size_type view_size
)
3322 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
3324 // leal foo@TLSDESC(%ebx), %eax
3325 // ==> movl foo@GOTNTPOFF(%ebx), %eax
3326 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3327 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3328 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3329 view
[-2] == 0x8d && view
[-1] == 0x83);
3331 Relocate_functions
<32, false>::rel32(view
, value
);
3335 // call *foo@TLSCALL(%eax)
3337 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
3338 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
3339 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3340 view
[0] == 0xff && view
[1] == 0x10);
3346 // Do a relocation in which we convert a TLS Local-Dynamic to a
3350 Target_i386::Relocate::tls_ld_to_le(const Relocate_info
<32, false>* relinfo
,
3353 const elfcpp::Rel
<32, false>& rel
,
3355 elfcpp::Elf_types
<32>::Elf_Addr
,
3356 unsigned char* view
,
3357 section_size_type view_size
)
3359 // leal foo(%reg), %eax; call ___tls_get_addr
3360 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
3362 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3363 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
3365 // FIXME: Does this test really always pass?
3366 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3367 view
[-2] == 0x8d && view
[-1] == 0x83);
3369 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
3371 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
3373 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3375 this->skip_call_tls_get_addr_
= true;
3378 // Do a relocation in which we convert a TLS Initial-Exec to a
3382 Target_i386::Relocate::tls_ie_to_le(const Relocate_info
<32, false>* relinfo
,
3384 Output_segment
* tls_segment
,
3385 const elfcpp::Rel
<32, false>& rel
,
3386 unsigned int r_type
,
3387 elfcpp::Elf_types
<32>::Elf_Addr value
,
3388 unsigned char* view
,
3389 section_size_type view_size
)
3391 // We have to actually change the instructions, which means that we
3392 // need to examine the opcodes to figure out which instruction we
3394 if (r_type
== elfcpp::R_386_TLS_IE
)
3396 // movl %gs:XX,%eax ==> movl $YY,%eax
3397 // movl %gs:XX,%reg ==> movl $YY,%reg
3398 // addl %gs:XX,%reg ==> addl $YY,%reg
3399 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -1);
3400 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3402 unsigned char op1
= view
[-1];
3405 // movl XX,%eax ==> movl $YY,%eax
3410 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3412 unsigned char op2
= view
[-2];
3415 // movl XX,%reg ==> movl $YY,%reg
3416 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3417 (op1
& 0xc7) == 0x05);
3419 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3421 else if (op2
== 0x03)
3423 // addl XX,%reg ==> addl $YY,%reg
3424 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3425 (op1
& 0xc7) == 0x05);
3427 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3430 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
3435 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
3436 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
3437 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
3438 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3439 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3441 unsigned char op1
= view
[-1];
3442 unsigned char op2
= view
[-2];
3443 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3444 (op1
& 0xc0) == 0x80 && (op1
& 7) != 4);
3447 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
3449 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3451 else if (op2
== 0x2b)
3453 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
3455 view
[-1] = 0xe8 | ((op1
>> 3) & 7);
3457 else if (op2
== 0x03)
3459 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
3461 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3464 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
3467 value
= tls_segment
->memsz() - value
;
3468 if (r_type
== elfcpp::R_386_TLS_IE
|| r_type
== elfcpp::R_386_TLS_GOTIE
)
3471 Relocate_functions
<32, false>::rel32(view
, value
);
3474 // Relocate section data.
3477 Target_i386::relocate_section(const Relocate_info
<32, false>* relinfo
,
3478 unsigned int sh_type
,
3479 const unsigned char* prelocs
,
3481 Output_section
* output_section
,
3482 bool needs_special_offset_handling
,
3483 unsigned char* view
,
3484 elfcpp::Elf_types
<32>::Elf_Addr address
,
3485 section_size_type view_size
,
3486 const Reloc_symbol_changes
* reloc_symbol_changes
)
3488 gold_assert(sh_type
== elfcpp::SHT_REL
);
3490 gold::relocate_section
<32, false, Target_i386
, elfcpp::SHT_REL
,
3491 Target_i386::Relocate
, gold::Default_comdat_behavior
>(
3497 needs_special_offset_handling
,
3501 reloc_symbol_changes
);
3504 // Return the size of a relocation while scanning during a relocatable
3508 Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
3509 unsigned int r_type
,
3514 case elfcpp::R_386_NONE
:
3515 case elfcpp::R_386_GNU_VTINHERIT
:
3516 case elfcpp::R_386_GNU_VTENTRY
:
3517 case elfcpp::R_386_TLS_GD
: // Global-dynamic
3518 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
3519 case elfcpp::R_386_TLS_DESC_CALL
:
3520 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
3521 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
3522 case elfcpp::R_386_TLS_IE
: // Initial-exec
3523 case elfcpp::R_386_TLS_IE_32
:
3524 case elfcpp::R_386_TLS_GOTIE
:
3525 case elfcpp::R_386_TLS_LE
: // Local-exec
3526 case elfcpp::R_386_TLS_LE_32
:
3529 case elfcpp::R_386_32
:
3530 case elfcpp::R_386_PC32
:
3531 case elfcpp::R_386_GOT32
:
3532 case elfcpp::R_386_PLT32
:
3533 case elfcpp::R_386_GOTOFF
:
3534 case elfcpp::R_386_GOTPC
:
3537 case elfcpp::R_386_16
:
3538 case elfcpp::R_386_PC16
:
3541 case elfcpp::R_386_8
:
3542 case elfcpp::R_386_PC8
:
3545 // These are relocations which should only be seen by the
3546 // dynamic linker, and should never be seen here.
3547 case elfcpp::R_386_COPY
:
3548 case elfcpp::R_386_GLOB_DAT
:
3549 case elfcpp::R_386_JUMP_SLOT
:
3550 case elfcpp::R_386_RELATIVE
:
3551 case elfcpp::R_386_IRELATIVE
:
3552 case elfcpp::R_386_TLS_TPOFF
:
3553 case elfcpp::R_386_TLS_DTPMOD32
:
3554 case elfcpp::R_386_TLS_DTPOFF32
:
3555 case elfcpp::R_386_TLS_TPOFF32
:
3556 case elfcpp::R_386_TLS_DESC
:
3557 object
->error(_("unexpected reloc %u in object file"), r_type
);
3560 case elfcpp::R_386_32PLT
:
3561 case elfcpp::R_386_TLS_GD_32
:
3562 case elfcpp::R_386_TLS_GD_PUSH
:
3563 case elfcpp::R_386_TLS_GD_CALL
:
3564 case elfcpp::R_386_TLS_GD_POP
:
3565 case elfcpp::R_386_TLS_LDM_32
:
3566 case elfcpp::R_386_TLS_LDM_PUSH
:
3567 case elfcpp::R_386_TLS_LDM_CALL
:
3568 case elfcpp::R_386_TLS_LDM_POP
:
3569 case elfcpp::R_386_USED_BY_INTEL_200
:
3571 object
->error(_("unsupported reloc %u in object file"), r_type
);
3576 // Scan the relocs during a relocatable link.
3579 Target_i386::scan_relocatable_relocs(Symbol_table
* symtab
,
3581 Sized_relobj_file
<32, false>* object
,
3582 unsigned int data_shndx
,
3583 unsigned int sh_type
,
3584 const unsigned char* prelocs
,
3586 Output_section
* output_section
,
3587 bool needs_special_offset_handling
,
3588 size_t local_symbol_count
,
3589 const unsigned char* plocal_symbols
,
3590 Relocatable_relocs
* rr
)
3592 gold_assert(sh_type
== elfcpp::SHT_REL
);
3594 typedef gold::Default_scan_relocatable_relocs
<elfcpp::SHT_REL
,
3595 Relocatable_size_for_reloc
> Scan_relocatable_relocs
;
3597 gold::scan_relocatable_relocs
<32, false, elfcpp::SHT_REL
,
3598 Scan_relocatable_relocs
>(
3606 needs_special_offset_handling
,
3612 // Emit relocations for a section.
3615 Target_i386::relocate_relocs(
3616 const Relocate_info
<32, false>* relinfo
,
3617 unsigned int sh_type
,
3618 const unsigned char* prelocs
,
3620 Output_section
* output_section
,
3621 elfcpp::Elf_types
<32>::Elf_Off offset_in_output_section
,
3622 const Relocatable_relocs
* rr
,
3623 unsigned char* view
,
3624 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
3625 section_size_type view_size
,
3626 unsigned char* reloc_view
,
3627 section_size_type reloc_view_size
)
3629 gold_assert(sh_type
== elfcpp::SHT_REL
);
3631 gold::relocate_relocs
<32, false, elfcpp::SHT_REL
>(
3636 offset_in_output_section
,
3645 // Return the value to use for a dynamic which requires special
3646 // treatment. This is how we support equality comparisons of function
3647 // pointers across shared library boundaries, as described in the
3648 // processor specific ABI supplement.
3651 Target_i386::do_dynsym_value(const Symbol
* gsym
) const
3653 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
3654 return this->plt_address_for_global(gsym
);
3657 // Return a string used to fill a code section with nops to take up
3658 // the specified length.
3661 Target_i386::do_code_fill(section_size_type length
) const
3665 // Build a jmp instruction to skip over the bytes.
3666 unsigned char jmp
[5];
3668 elfcpp::Swap_unaligned
<32, false>::writeval(jmp
+ 1, length
- 5);
3669 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
3670 + std::string(length
- 5, static_cast<char>(0x90)));
3673 // Nop sequences of various lengths.
3674 const char nop1
[1] = { '\x90' }; // nop
3675 const char nop2
[2] = { '\x66', '\x90' }; // xchg %ax %ax
3676 const char nop3
[3] = { '\x8d', '\x76', '\x00' }; // leal 0(%esi),%esi
3677 const char nop4
[4] = { '\x8d', '\x74', '\x26', // leal 0(%esi,1),%esi
3679 const char nop5
[5] = { '\x90', '\x8d', '\x74', // nop
3680 '\x26', '\x00' }; // leal 0(%esi,1),%esi
3681 const char nop6
[6] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3682 '\x00', '\x00', '\x00' };
3683 const char nop7
[7] = { '\x8d', '\xb4', '\x26', // leal 0L(%esi,1),%esi
3684 '\x00', '\x00', '\x00',
3686 const char nop8
[8] = { '\x90', '\x8d', '\xb4', // nop
3687 '\x26', '\x00', '\x00', // leal 0L(%esi,1),%esi
3689 const char nop9
[9] = { '\x89', '\xf6', '\x8d', // movl %esi,%esi
3690 '\xbc', '\x27', '\x00', // leal 0L(%edi,1),%edi
3691 '\x00', '\x00', '\x00' };
3692 const char nop10
[10] = { '\x8d', '\x76', '\x00', // leal 0(%esi),%esi
3693 '\x8d', '\xbc', '\x27', // leal 0L(%edi,1),%edi
3694 '\x00', '\x00', '\x00',
3696 const char nop11
[11] = { '\x8d', '\x74', '\x26', // leal 0(%esi,1),%esi
3697 '\x00', '\x8d', '\xbc', // leal 0L(%edi,1),%edi
3698 '\x27', '\x00', '\x00',
3700 const char nop12
[12] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3701 '\x00', '\x00', '\x00', // leal 0L(%edi),%edi
3702 '\x8d', '\xbf', '\x00',
3703 '\x00', '\x00', '\x00' };
3704 const char nop13
[13] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3705 '\x00', '\x00', '\x00', // leal 0L(%edi,1),%edi
3706 '\x8d', '\xbc', '\x27',
3707 '\x00', '\x00', '\x00',
3709 const char nop14
[14] = { '\x8d', '\xb4', '\x26', // leal 0L(%esi,1),%esi
3710 '\x00', '\x00', '\x00', // leal 0L(%edi,1),%edi
3711 '\x00', '\x8d', '\xbc',
3712 '\x27', '\x00', '\x00',
3714 const char nop15
[15] = { '\xeb', '\x0d', '\x90', // jmp .+15
3715 '\x90', '\x90', '\x90', // nop,nop,nop,...
3716 '\x90', '\x90', '\x90',
3717 '\x90', '\x90', '\x90',
3718 '\x90', '\x90', '\x90' };
3720 const char* nops
[16] = {
3722 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
3723 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
3726 return std::string(nops
[length
], length
);
3729 // Return the value to use for the base of a DW_EH_PE_datarel offset
3730 // in an FDE. Solaris and SVR4 use DW_EH_PE_datarel because their
3731 // assembler can not write out the difference between two labels in
3732 // different sections, so instead of using a pc-relative value they
3733 // use an offset from the GOT.
3736 Target_i386::do_ehframe_datarel_base() const
3738 gold_assert(this->global_offset_table_
!= NULL
);
3739 Symbol
* sym
= this->global_offset_table_
;
3740 Sized_symbol
<32>* ssym
= static_cast<Sized_symbol
<32>*>(sym
);
3741 return ssym
->value();
3744 // Return whether SYM should be treated as a call to a non-split
3745 // function. We don't want that to be true of a call to a
3746 // get_pc_thunk function.
3749 Target_i386::do_is_call_to_non_split(const Symbol
* sym
, unsigned int) const
3751 return (sym
->type() == elfcpp::STT_FUNC
3752 && !is_prefix_of("__i686.get_pc_thunk.", sym
->name()));
3755 // FNOFFSET in section SHNDX in OBJECT is the start of a function
3756 // compiled with -fsplit-stack. The function calls non-split-stack
3757 // code. We have to change the function so that it always ensures
3758 // that it has enough stack space to run some random function.
3761 Target_i386::do_calls_non_split(Relobj
* object
, unsigned int shndx
,
3762 section_offset_type fnoffset
,
3763 section_size_type fnsize
,
3764 unsigned char* view
,
3765 section_size_type view_size
,
3767 std::string
* to
) const
3769 // The function starts with a comparison of the stack pointer and a
3770 // field in the TCB. This is followed by a jump.
3773 if (this->match_view(view
, view_size
, fnoffset
, "\x65\x3b\x25", 3)
3776 // We will call __morestack if the carry flag is set after this
3777 // comparison. We turn the comparison into an stc instruction
3779 view
[fnoffset
] = '\xf9';
3780 this->set_view_to_nop(view
, view_size
, fnoffset
+ 1, 6);
3782 // lea NN(%esp),%ecx
3783 // lea NN(%esp),%edx
3784 else if ((this->match_view(view
, view_size
, fnoffset
, "\x8d\x8c\x24", 3)
3785 || this->match_view(view
, view_size
, fnoffset
, "\x8d\x94\x24", 3))
3788 // This is loading an offset from the stack pointer for a
3789 // comparison. The offset is negative, so we decrease the
3790 // offset by the amount of space we need for the stack. This
3791 // means we will avoid calling __morestack if there happens to
3792 // be plenty of space on the stack already.
3793 unsigned char* pval
= view
+ fnoffset
+ 3;
3794 uint32_t val
= elfcpp::Swap_unaligned
<32, false>::readval(pval
);
3795 val
-= parameters
->options().split_stack_adjust_size();
3796 elfcpp::Swap_unaligned
<32, false>::writeval(pval
, val
);
3800 if (!object
->has_no_split_stack())
3801 object
->error(_("failed to match split-stack sequence at "
3802 "section %u offset %0zx"),
3803 shndx
, static_cast<size_t>(fnoffset
));
3807 // We have to change the function so that it calls
3808 // __morestack_non_split instead of __morestack. The former will
3809 // allocate additional stack space.
3810 *from
= "__morestack";
3811 *to
= "__morestack_non_split";
3814 // The selector for i386 object files. Note this is never instantiated
3815 // directly. It's only used in Target_selector_i386_nacl, below.
3817 class Target_selector_i386
: public Target_selector_freebsd
3820 Target_selector_i386()
3821 : Target_selector_freebsd(elfcpp::EM_386
, 32, false,
3822 "elf32-i386", "elf32-i386-freebsd",
3827 do_instantiate_target()
3828 { return new Target_i386(); }
3831 // NaCl variant. It uses different PLT contents.
3833 class Output_data_plt_i386_nacl
: public Output_data_plt_i386
3836 Output_data_plt_i386_nacl(Layout
* layout
,
3837 Output_data_space
* got_plt
,
3838 Output_data_space
* got_irelative
)
3839 : Output_data_plt_i386(layout
, plt_entry_size
, got_plt
, got_irelative
)
3843 virtual unsigned int
3844 do_get_plt_entry_size() const
3845 { return plt_entry_size
; }
3848 do_add_eh_frame(Layout
* layout
)
3850 layout
->add_eh_frame_for_plt(this, plt_eh_frame_cie
, plt_eh_frame_cie_size
,
3851 plt_eh_frame_fde
, plt_eh_frame_fde_size
);
3854 // The size of an entry in the PLT.
3855 static const int plt_entry_size
= 64;
3857 // The .eh_frame unwind information for the PLT.
3858 static const int plt_eh_frame_fde_size
= 32;
3859 static const unsigned char plt_eh_frame_fde
[plt_eh_frame_fde_size
];
3862 class Output_data_plt_i386_nacl_exec
: public Output_data_plt_i386_nacl
3865 Output_data_plt_i386_nacl_exec(Layout
* layout
,
3866 Output_data_space
* got_plt
,
3867 Output_data_space
* got_irelative
)
3868 : Output_data_plt_i386_nacl(layout
, got_plt
, got_irelative
)
3873 do_fill_first_plt_entry(unsigned char* pov
,
3874 elfcpp::Elf_types
<32>::Elf_Addr got_address
);
3876 virtual unsigned int
3877 do_fill_plt_entry(unsigned char* pov
,
3878 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
3879 unsigned int got_offset
,
3880 unsigned int plt_offset
,
3881 unsigned int plt_rel_offset
);
3884 // The first entry in the PLT for an executable.
3885 static const unsigned char first_plt_entry
[plt_entry_size
];
3887 // Other entries in the PLT for an executable.
3888 static const unsigned char plt_entry
[plt_entry_size
];
3891 class Output_data_plt_i386_nacl_dyn
: public Output_data_plt_i386_nacl
3894 Output_data_plt_i386_nacl_dyn(Layout
* layout
,
3895 Output_data_space
* got_plt
,
3896 Output_data_space
* got_irelative
)
3897 : Output_data_plt_i386_nacl(layout
, got_plt
, got_irelative
)
3902 do_fill_first_plt_entry(unsigned char* pov
, elfcpp::Elf_types
<32>::Elf_Addr
);
3904 virtual unsigned int
3905 do_fill_plt_entry(unsigned char* pov
,
3906 elfcpp::Elf_types
<32>::Elf_Addr
,
3907 unsigned int got_offset
,
3908 unsigned int plt_offset
,
3909 unsigned int plt_rel_offset
);
3912 // The first entry in the PLT for a shared object.
3913 static const unsigned char first_plt_entry
[plt_entry_size
];
3915 // Other entries in the PLT for a shared object.
3916 static const unsigned char plt_entry
[plt_entry_size
];
3919 class Target_i386_nacl
: public Target_i386
3923 : Target_i386(&i386_nacl_info
)
3927 virtual Output_data_plt_i386
*
3928 do_make_data_plt(Layout
* layout
,
3929 Output_data_space
* got_plt
,
3930 Output_data_space
* got_irelative
,
3934 return new Output_data_plt_i386_nacl_dyn(layout
, got_plt
, got_irelative
);
3936 return new Output_data_plt_i386_nacl_exec(layout
, got_plt
, got_irelative
);
3940 do_code_fill(section_size_type length
) const;
3943 static const Target::Target_info i386_nacl_info
;
3946 const Target::Target_info
Target_i386_nacl::i386_nacl_info
=
3949 false, // is_big_endian
3950 elfcpp::EM_386
, // machine_code
3951 false, // has_make_symbol
3952 false, // has_resolve
3953 true, // has_code_fill
3954 true, // is_default_stack_executable
3955 true, // can_icf_inline_merge_sections
3957 "/lib/ld-nacl-x86-32.so.1", // dynamic_linker
3958 0x20000, // default_text_segment_address
3959 0x10000, // abi_pagesize (overridable by -z max-page-size)
3960 0x10000, // common_pagesize (overridable by -z common-page-size)
3961 true, // isolate_execinstr
3962 0x10000000, // rosegment_gap
3963 elfcpp::SHN_UNDEF
, // small_common_shndx
3964 elfcpp::SHN_UNDEF
, // large_common_shndx
3965 0, // small_common_section_flags
3966 0, // large_common_section_flags
3967 NULL
, // attributes_section
3968 NULL
, // attributes_vendor
3969 "_start" // entry_symbol_name
3972 #define NACLMASK 0xe0 // 32-byte alignment mask
3975 Output_data_plt_i386_nacl_exec::first_plt_entry
[plt_entry_size
] =
3977 0xff, 0x35, // pushl contents of memory address
3978 0, 0, 0, 0, // replaced with address of .got + 4
3979 0x8b, 0x0d, // movl contents of address, %ecx
3980 0, 0, 0, 0, // replaced with address of .got + 8
3981 0x83, 0xe1, NACLMASK
, // andl $NACLMASK, %ecx
3982 0xff, 0xe1, // jmp *%ecx
3983 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3984 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3985 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3986 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3987 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3988 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3989 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3990 0x90, 0x90, 0x90, 0x90, 0x90
3994 Output_data_plt_i386_nacl_exec::do_fill_first_plt_entry(
3996 elfcpp::Elf_types
<32>::Elf_Addr got_address
)
3998 memcpy(pov
, first_plt_entry
, plt_entry_size
);
3999 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 4);
4000 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 8);
4003 // The first entry in the PLT for a shared object.
4006 Output_data_plt_i386_nacl_dyn::first_plt_entry
[plt_entry_size
] =
4008 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
4009 0x8b, 0x4b, 0x08, // mov 0x8(%ebx), %ecx
4010 0x83, 0xe1, NACLMASK
, // andl $NACLMASK, %ecx
4011 0xff, 0xe1, // jmp *%ecx
4012 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4013 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4014 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4015 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4016 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4017 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4018 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4019 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4020 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4021 0x90, 0x90, 0x90, 0x90, 0x90 // nops
4025 Output_data_plt_i386_nacl_dyn::do_fill_first_plt_entry(
4027 elfcpp::Elf_types
<32>::Elf_Addr
)
4029 memcpy(pov
, first_plt_entry
, plt_entry_size
);
4032 // Subsequent entries in the PLT for an executable.
4035 Output_data_plt_i386_nacl_exec::plt_entry
[plt_entry_size
] =
4037 0x8b, 0x0d, // movl contents of address, %ecx */
4038 0, 0, 0, 0, // replaced with address of symbol in .got
4039 0x83, 0xe1, NACLMASK
, // andl $NACLMASK, %ecx
4040 0xff, 0xe1, // jmp *%ecx
4042 // Pad to the next 32-byte boundary with nop instructions.
4044 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4045 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4047 // Lazy GOT entries point here (32-byte aligned).
4048 0x68, // pushl immediate
4049 0, 0, 0, 0, // replaced with offset into relocation table
4050 0xe9, // jmp relative
4051 0, 0, 0, 0, // replaced with offset to start of .plt
4053 // Pad to the next 32-byte boundary with nop instructions.
4054 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4055 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4060 Output_data_plt_i386_nacl_exec::do_fill_plt_entry(
4062 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
4063 unsigned int got_offset
,
4064 unsigned int plt_offset
,
4065 unsigned int plt_rel_offset
)
4067 memcpy(pov
, plt_entry
, plt_entry_size
);
4068 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
4069 got_address
+ got_offset
);
4070 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 33, plt_rel_offset
);
4071 elfcpp::Swap
<32, false>::writeval(pov
+ 38, - (plt_offset
+ 38 + 4));
4075 // Subsequent entries in the PLT for a shared object.
4078 Output_data_plt_i386_nacl_dyn::plt_entry
[plt_entry_size
] =
4080 0x8b, 0x8b, // movl offset(%ebx), %ecx
4081 0, 0, 0, 0, // replaced with offset of symbol in .got
4082 0x83, 0xe1, 0xe0, // andl $NACLMASK, %ecx
4083 0xff, 0xe1, // jmp *%ecx
4085 // Pad to the next 32-byte boundary with nop instructions.
4087 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4088 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4090 // Lazy GOT entries point here (32-byte aligned).
4091 0x68, // pushl immediate
4092 0, 0, 0, 0, // replaced with offset into relocation table.
4093 0xe9, // jmp relative
4094 0, 0, 0, 0, // replaced with offset to start of .plt.
4096 // Pad to the next 32-byte boundary with nop instructions.
4097 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4098 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4103 Output_data_plt_i386_nacl_dyn::do_fill_plt_entry(
4105 elfcpp::Elf_types
<32>::Elf_Addr
,
4106 unsigned int got_offset
,
4107 unsigned int plt_offset
,
4108 unsigned int plt_rel_offset
)
4110 memcpy(pov
, plt_entry
, plt_entry_size
);
4111 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
4112 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 33, plt_rel_offset
);
4113 elfcpp::Swap
<32, false>::writeval(pov
+ 38, - (plt_offset
+ 38 + 4));
4118 Output_data_plt_i386_nacl::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
4120 0, 0, 0, 0, // Replaced with offset to .plt.
4121 0, 0, 0, 0, // Replaced with size of .plt.
4122 0, // Augmentation size.
4123 elfcpp::DW_CFA_def_cfa_offset
, 8, // DW_CFA_def_cfa_offset: 8.
4124 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
4125 elfcpp::DW_CFA_def_cfa_offset
, 12, // DW_CFA_def_cfa_offset: 12.
4126 elfcpp::DW_CFA_advance_loc
+ 58, // Advance 58 to __PLT__ + 64.
4127 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
4128 13, // Block length.
4129 elfcpp::DW_OP_breg4
, 4, // Push %esp + 4.
4130 elfcpp::DW_OP_breg8
, 0, // Push %eip.
4131 elfcpp::DW_OP_const1u
, 63, // Push 0x3f.
4132 elfcpp::DW_OP_and
, // & (%eip & 0x3f).
4133 elfcpp::DW_OP_const1u
, 37, // Push 0x25.
4134 elfcpp::DW_OP_ge
, // >= ((%eip & 0x3f) >= 0x25)
4135 elfcpp::DW_OP_lit2
, // Push 2.
4136 elfcpp::DW_OP_shl
, // << (((%eip & 0x3f) >= 0x25) << 2)
4137 elfcpp::DW_OP_plus
, // + ((((%eip&0x3f)>=0x25)<<2)+%esp+4
4138 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
4142 // Return a string used to fill a code section with nops.
4143 // For NaCl, long NOPs are only valid if they do not cross
4144 // bundle alignment boundaries, so keep it simple with one-byte NOPs.
4146 Target_i386_nacl::do_code_fill(section_size_type length
) const
4148 return std::string(length
, static_cast<char>(0x90));
4151 // The selector for i386-nacl object files.
4153 class Target_selector_i386_nacl
4154 : public Target_selector_nacl
<Target_selector_i386
, Target_i386_nacl
>
4157 Target_selector_i386_nacl()
4158 : Target_selector_nacl
<Target_selector_i386
,
4159 Target_i386_nacl
>("x86-32",
4165 Target_selector_i386_nacl target_selector_i386
;
4167 } // End anonymous namespace.