1 // i386.cc -- i386 target support for gold.
3 // Copyright (C) 2006-2015 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 .got.plt section.
52 class Output_data_got_plt_i386
: public Output_section_data_build
55 Output_data_got_plt_i386(Layout
* layout
)
56 : Output_section_data_build(4),
61 // Write out the PLT data.
63 do_write(Output_file
*);
65 // Write to a map file.
67 do_print_to_mapfile(Mapfile
* mapfile
) const
68 { mapfile
->print_output_data(this, "** GOT PLT"); }
71 // A pointer to the Layout class, so that we can find the .dynamic
72 // section when we write out the GOT PLT section.
76 // A class to handle the PLT data.
77 // This is an abstract base class that handles most of the linker details
78 // but does not know the actual contents of PLT entries. The derived
79 // classes below fill in those details.
81 class Output_data_plt_i386
: public Output_section_data
84 typedef Output_data_reloc
<elfcpp::SHT_REL
, true, 32, false> Reloc_section
;
86 Output_data_plt_i386(Layout
*, uint64_t addralign
,
87 Output_data_got_plt_i386
*, Output_data_space
*);
89 // Add an entry to the PLT.
91 add_entry(Symbol_table
*, Layout
*, Symbol
* gsym
);
93 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
95 add_local_ifunc_entry(Symbol_table
*, Layout
*,
96 Sized_relobj_file
<32, false>* relobj
,
97 unsigned int local_sym_index
);
99 // Return the .rel.plt section data.
102 { return this->rel_
; }
104 // Return where the TLS_DESC relocations should go.
106 rel_tls_desc(Layout
*);
108 // Return where the IRELATIVE relocations should go.
110 rel_irelative(Symbol_table
*, Layout
*);
112 // Return whether we created a section for IRELATIVE relocations.
114 has_irelative_section() const
115 { return this->irelative_rel_
!= NULL
; }
117 // Return the number of PLT entries.
120 { return this->count_
+ this->irelative_count_
; }
122 // Return the offset of the first non-reserved PLT entry.
124 first_plt_entry_offset()
125 { return this->get_plt_entry_size(); }
127 // Return the size of a PLT entry.
129 get_plt_entry_size() const
130 { return this->do_get_plt_entry_size(); }
132 // Return the PLT address to use for a global symbol.
134 address_for_global(const Symbol
*);
136 // Return the PLT address to use for a local symbol.
138 address_for_local(const Relobj
*, unsigned int symndx
);
140 // Add .eh_frame information for the PLT.
142 add_eh_frame(Layout
* layout
)
143 { this->do_add_eh_frame(layout
); }
146 // Fill the first PLT entry, given the pointer to the PLT section data
147 // and the runtime address of the GOT.
149 fill_first_plt_entry(unsigned char* pov
,
150 elfcpp::Elf_types
<32>::Elf_Addr got_address
)
151 { this->do_fill_first_plt_entry(pov
, got_address
); }
153 // Fill a normal PLT entry, given the pointer to the entry's data in the
154 // section, the runtime address of the GOT, the offset into the GOT of
155 // the corresponding slot, the offset into the relocation section of the
156 // corresponding reloc, and the offset of this entry within the whole
157 // PLT. Return the offset from this PLT entry's runtime address that
158 // should be used to compute the initial value of the GOT slot.
160 fill_plt_entry(unsigned char* pov
,
161 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
162 unsigned int got_offset
,
163 unsigned int plt_offset
,
164 unsigned int plt_rel_offset
)
166 return this->do_fill_plt_entry(pov
, got_address
, got_offset
,
167 plt_offset
, plt_rel_offset
);
171 do_get_plt_entry_size() const = 0;
174 do_fill_first_plt_entry(unsigned char* pov
,
175 elfcpp::Elf_types
<32>::Elf_Addr got_address
) = 0;
178 do_fill_plt_entry(unsigned char* pov
,
179 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
180 unsigned int got_offset
,
181 unsigned int plt_offset
,
182 unsigned int plt_rel_offset
) = 0;
185 do_add_eh_frame(Layout
*) = 0;
188 do_adjust_output_section(Output_section
* os
);
190 // Write to a map file.
192 do_print_to_mapfile(Mapfile
* mapfile
) const
193 { mapfile
->print_output_data(this, _("** PLT")); }
195 // The .eh_frame unwind information for the PLT.
196 // The CIE is common across variants of the PLT format.
197 static const int plt_eh_frame_cie_size
= 16;
198 static const unsigned char plt_eh_frame_cie
[plt_eh_frame_cie_size
];
201 // Set the final size.
203 set_final_data_size()
205 this->set_data_size((this->count_
+ this->irelative_count_
+ 1)
206 * this->get_plt_entry_size());
209 // Write out the PLT data.
211 do_write(Output_file
*);
213 // We keep a list of global STT_GNU_IFUNC symbols, each with its
214 // offset in the GOT.
218 unsigned int got_offset
;
221 // We keep a list of local STT_GNU_IFUNC symbols, each with its
222 // offset in the GOT.
225 Sized_relobj_file
<32, false>* object
;
226 unsigned int local_sym_index
;
227 unsigned int got_offset
;
230 // The reloc section.
232 // The TLS_DESC relocations, if necessary. These must follow the
233 // regular PLT relocs.
234 Reloc_section
* tls_desc_rel_
;
235 // The IRELATIVE relocations, if necessary. These must follow the
236 // regular relocatoins and the TLS_DESC relocations.
237 Reloc_section
* irelative_rel_
;
238 // The .got.plt section.
239 Output_data_got_plt_i386
* got_plt_
;
240 // The part of the .got.plt section used for IRELATIVE relocs.
241 Output_data_space
* got_irelative_
;
242 // The number of PLT entries.
244 // Number of PLT entries with R_386_IRELATIVE relocs. These follow
245 // the regular PLT entries.
246 unsigned int irelative_count_
;
247 // Global STT_GNU_IFUNC symbols.
248 std::vector
<Global_ifunc
> global_ifuncs_
;
249 // Local STT_GNU_IFUNC symbols.
250 std::vector
<Local_ifunc
> local_ifuncs_
;
253 // This is an abstract class for the standard PLT layout.
254 // The derived classes below handle the actual PLT contents
255 // for the executable (non-PIC) and shared-library (PIC) cases.
256 // The unwind information is uniform across those two, so it's here.
258 class Output_data_plt_i386_standard
: public Output_data_plt_i386
261 Output_data_plt_i386_standard(Layout
* layout
,
262 Output_data_got_plt_i386
* got_plt
,
263 Output_data_space
* got_irelative
)
264 : Output_data_plt_i386(layout
, plt_entry_size
, got_plt
, got_irelative
)
269 do_get_plt_entry_size() const
270 { return plt_entry_size
; }
273 do_add_eh_frame(Layout
* layout
)
275 layout
->add_eh_frame_for_plt(this, plt_eh_frame_cie
, plt_eh_frame_cie_size
,
276 plt_eh_frame_fde
, plt_eh_frame_fde_size
);
279 // The size of an entry in the PLT.
280 static const int plt_entry_size
= 16;
282 // The .eh_frame unwind information for the PLT.
283 static const int plt_eh_frame_fde_size
= 32;
284 static const unsigned char plt_eh_frame_fde
[plt_eh_frame_fde_size
];
287 // Actually fill the PLT contents for an executable (non-PIC).
289 class Output_data_plt_i386_exec
: public Output_data_plt_i386_standard
292 Output_data_plt_i386_exec(Layout
* layout
,
293 Output_data_got_plt_i386
* got_plt
,
294 Output_data_space
* got_irelative
)
295 : Output_data_plt_i386_standard(layout
, got_plt
, got_irelative
)
300 do_fill_first_plt_entry(unsigned char* pov
,
301 elfcpp::Elf_types
<32>::Elf_Addr got_address
);
304 do_fill_plt_entry(unsigned char* pov
,
305 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
306 unsigned int got_offset
,
307 unsigned int plt_offset
,
308 unsigned int plt_rel_offset
);
311 // The first entry in the PLT for an executable.
312 static const unsigned char first_plt_entry
[plt_entry_size
];
314 // Other entries in the PLT for an executable.
315 static const unsigned char plt_entry
[plt_entry_size
];
318 // Actually fill the PLT contents for a shared library (PIC).
320 class Output_data_plt_i386_dyn
: public Output_data_plt_i386_standard
323 Output_data_plt_i386_dyn(Layout
* layout
,
324 Output_data_got_plt_i386
* got_plt
,
325 Output_data_space
* got_irelative
)
326 : Output_data_plt_i386_standard(layout
, got_plt
, got_irelative
)
331 do_fill_first_plt_entry(unsigned char* pov
, elfcpp::Elf_types
<32>::Elf_Addr
);
334 do_fill_plt_entry(unsigned char* pov
,
335 elfcpp::Elf_types
<32>::Elf_Addr
,
336 unsigned int got_offset
,
337 unsigned int plt_offset
,
338 unsigned int plt_rel_offset
);
341 // The first entry in the PLT for a shared object.
342 static const unsigned char first_plt_entry
[plt_entry_size
];
344 // Other entries in the PLT for a shared object.
345 static const unsigned char plt_entry
[plt_entry_size
];
348 // The i386 target class.
349 // TLS info comes from
350 // http://people.redhat.com/drepper/tls.pdf
351 // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
353 class Target_i386
: public Sized_target
<32, false>
356 typedef Output_data_reloc
<elfcpp::SHT_REL
, true, 32, false> Reloc_section
;
358 Target_i386(const Target::Target_info
* info
= &i386_info
)
359 : Sized_target
<32, false>(info
),
360 got_(NULL
), plt_(NULL
), got_plt_(NULL
), got_irelative_(NULL
),
361 got_tlsdesc_(NULL
), global_offset_table_(NULL
), rel_dyn_(NULL
),
362 rel_irelative_(NULL
), copy_relocs_(elfcpp::R_386_COPY
),
363 got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
366 // Process the relocations to determine unreferenced sections for
367 // garbage collection.
369 gc_process_relocs(Symbol_table
* symtab
,
371 Sized_relobj_file
<32, false>* object
,
372 unsigned int data_shndx
,
373 unsigned int sh_type
,
374 const unsigned char* prelocs
,
376 Output_section
* output_section
,
377 bool needs_special_offset_handling
,
378 size_t local_symbol_count
,
379 const unsigned char* plocal_symbols
);
381 // Scan the relocations to look for symbol adjustments.
383 scan_relocs(Symbol_table
* symtab
,
385 Sized_relobj_file
<32, false>* object
,
386 unsigned int data_shndx
,
387 unsigned int sh_type
,
388 const unsigned char* prelocs
,
390 Output_section
* output_section
,
391 bool needs_special_offset_handling
,
392 size_t local_symbol_count
,
393 const unsigned char* plocal_symbols
);
395 // Finalize the sections.
397 do_finalize_sections(Layout
*, const Input_objects
*, Symbol_table
*);
399 // Return the value to use for a dynamic which requires special
402 do_dynsym_value(const Symbol
*) const;
404 // Relocate a section.
406 relocate_section(const Relocate_info
<32, false>*,
407 unsigned int sh_type
,
408 const unsigned char* prelocs
,
410 Output_section
* output_section
,
411 bool needs_special_offset_handling
,
413 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
414 section_size_type view_size
,
415 const Reloc_symbol_changes
*);
417 // Scan the relocs during a relocatable link.
419 scan_relocatable_relocs(Symbol_table
* symtab
,
421 Sized_relobj_file
<32, false>* object
,
422 unsigned int data_shndx
,
423 unsigned int sh_type
,
424 const unsigned char* prelocs
,
426 Output_section
* output_section
,
427 bool needs_special_offset_handling
,
428 size_t local_symbol_count
,
429 const unsigned char* plocal_symbols
,
430 Relocatable_relocs
*);
432 // Emit relocations for a section.
434 relocate_relocs(const Relocate_info
<32, false>*,
435 unsigned int sh_type
,
436 const unsigned char* prelocs
,
438 Output_section
* output_section
,
439 elfcpp::Elf_types
<32>::Elf_Off offset_in_output_section
,
440 const Relocatable_relocs
*,
442 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
443 section_size_type view_size
,
444 unsigned char* reloc_view
,
445 section_size_type reloc_view_size
);
447 // Return a string used to fill a code section with nops.
449 do_code_fill(section_size_type length
) const;
451 // Return whether SYM is defined by the ABI.
453 do_is_defined_by_abi(const Symbol
* sym
) const
454 { return strcmp(sym
->name(), "___tls_get_addr") == 0; }
456 // Return whether a symbol name implies a local label. The UnixWare
457 // 2.1 cc generates temporary symbols that start with .X, so we
458 // recognize them here. FIXME: do other SVR4 compilers also use .X?.
459 // If so, we should move the .X recognition into
460 // Target::do_is_local_label_name.
462 do_is_local_label_name(const char* name
) const
464 if (name
[0] == '.' && name
[1] == 'X')
466 return Target::do_is_local_label_name(name
);
469 // Return the PLT address to use for a global symbol.
471 do_plt_address_for_global(const Symbol
* gsym
) const
472 { return this->plt_section()->address_for_global(gsym
); }
475 do_plt_address_for_local(const Relobj
* relobj
, unsigned int symndx
) const
476 { return this->plt_section()->address_for_local(relobj
, symndx
); }
478 // We can tell whether we take the address of a function.
480 do_can_check_for_function_pointers() const
483 // Return the base for a DW_EH_PE_datarel encoding.
485 do_ehframe_datarel_base() const;
487 // Return whether SYM is call to a non-split function.
489 do_is_call_to_non_split(const Symbol
* sym
, unsigned int) const;
491 // Adjust -fsplit-stack code which calls non-split-stack code.
493 do_calls_non_split(Relobj
* object
, unsigned int shndx
,
494 section_offset_type fnoffset
, section_size_type fnsize
,
495 unsigned char* view
, section_size_type view_size
,
496 std::string
* from
, std::string
* to
) const;
498 // Return the size of the GOT section.
502 gold_assert(this->got_
!= NULL
);
503 return this->got_
->data_size();
506 // Return the number of entries in the GOT.
508 got_entry_count() const
510 if (this->got_
== NULL
)
512 return this->got_size() / 4;
515 // Return the number of entries in the PLT.
517 plt_entry_count() const;
519 // Return the offset of the first non-reserved PLT entry.
521 first_plt_entry_offset() const;
523 // Return the size of each PLT entry.
525 plt_entry_size() const;
528 // Instantiate the plt_ member.
529 // This chooses the right PLT flavor for an executable or a shared object.
530 Output_data_plt_i386
*
531 make_data_plt(Layout
* layout
,
532 Output_data_got_plt_i386
* got_plt
,
533 Output_data_space
* got_irelative
,
535 { return this->do_make_data_plt(layout
, got_plt
, got_irelative
, dyn
); }
537 virtual Output_data_plt_i386
*
538 do_make_data_plt(Layout
* layout
,
539 Output_data_got_plt_i386
* got_plt
,
540 Output_data_space
* got_irelative
,
544 return new Output_data_plt_i386_dyn(layout
, got_plt
, got_irelative
);
546 return new Output_data_plt_i386_exec(layout
, got_plt
, got_irelative
);
550 // The class which scans relocations.
555 get_reference_flags(unsigned int r_type
);
558 local(Symbol_table
* symtab
, Layout
* layout
, Target_i386
* target
,
559 Sized_relobj_file
<32, false>* object
,
560 unsigned int data_shndx
,
561 Output_section
* output_section
,
562 const elfcpp::Rel
<32, false>& reloc
, unsigned int r_type
,
563 const elfcpp::Sym
<32, false>& lsym
,
567 global(Symbol_table
* symtab
, Layout
* layout
, Target_i386
* target
,
568 Sized_relobj_file
<32, false>* object
,
569 unsigned int data_shndx
,
570 Output_section
* output_section
,
571 const elfcpp::Rel
<32, false>& reloc
, unsigned int r_type
,
575 local_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
577 Sized_relobj_file
<32, false>* object
,
578 unsigned int data_shndx
,
579 Output_section
* output_section
,
580 const elfcpp::Rel
<32, false>& reloc
,
582 const elfcpp::Sym
<32, false>& lsym
);
585 global_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
587 Sized_relobj_file
<32, false>* object
,
588 unsigned int data_shndx
,
589 Output_section
* output_section
,
590 const elfcpp::Rel
<32, false>& reloc
,
595 possible_function_pointer_reloc(unsigned int r_type
);
598 reloc_needs_plt_for_ifunc(Sized_relobj_file
<32, false>*,
599 unsigned int r_type
);
602 unsupported_reloc_local(Sized_relobj_file
<32, false>*, unsigned int r_type
);
605 unsupported_reloc_global(Sized_relobj_file
<32, false>*, unsigned int r_type
,
609 // The class which implements relocation.
614 : skip_call_tls_get_addr_(false),
615 local_dynamic_type_(LOCAL_DYNAMIC_NONE
)
620 if (this->skip_call_tls_get_addr_
)
622 // FIXME: This needs to specify the location somehow.
623 gold_error(_("missing expected TLS relocation"));
627 // Return whether the static relocation needs to be applied.
629 should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
632 Output_section
* output_section
);
634 // Do a relocation. Return false if the caller should not issue
635 // any warnings about this relocation.
637 relocate(const Relocate_info
<32, false>*, Target_i386
*, Output_section
*,
638 size_t relnum
, const elfcpp::Rel
<32, false>&,
639 unsigned int r_type
, const Sized_symbol
<32>*,
640 const Symbol_value
<32>*,
641 unsigned char*, elfcpp::Elf_types
<32>::Elf_Addr
,
645 // Do a TLS relocation.
647 relocate_tls(const Relocate_info
<32, false>*, Target_i386
* target
,
648 size_t relnum
, const elfcpp::Rel
<32, false>&,
649 unsigned int r_type
, const Sized_symbol
<32>*,
650 const Symbol_value
<32>*,
651 unsigned char*, elfcpp::Elf_types
<32>::Elf_Addr
,
654 // Do a TLS General-Dynamic to Initial-Exec transition.
656 tls_gd_to_ie(const Relocate_info
<32, false>*, size_t relnum
,
657 Output_segment
* tls_segment
,
658 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
659 elfcpp::Elf_types
<32>::Elf_Addr value
,
661 section_size_type view_size
);
663 // Do a TLS General-Dynamic to Local-Exec transition.
665 tls_gd_to_le(const Relocate_info
<32, false>*, size_t relnum
,
666 Output_segment
* tls_segment
,
667 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
668 elfcpp::Elf_types
<32>::Elf_Addr value
,
670 section_size_type view_size
);
672 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
675 tls_desc_gd_to_ie(const Relocate_info
<32, false>*, size_t relnum
,
676 Output_segment
* tls_segment
,
677 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
678 elfcpp::Elf_types
<32>::Elf_Addr value
,
680 section_size_type view_size
);
682 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
685 tls_desc_gd_to_le(const Relocate_info
<32, false>*, size_t relnum
,
686 Output_segment
* tls_segment
,
687 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
688 elfcpp::Elf_types
<32>::Elf_Addr value
,
690 section_size_type view_size
);
692 // Do a TLS Local-Dynamic to Local-Exec transition.
694 tls_ld_to_le(const Relocate_info
<32, false>*, size_t relnum
,
695 Output_segment
* tls_segment
,
696 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
697 elfcpp::Elf_types
<32>::Elf_Addr value
,
699 section_size_type view_size
);
701 // Do a TLS Initial-Exec to Local-Exec transition.
703 tls_ie_to_le(const Relocate_info
<32, false>*, size_t relnum
,
704 Output_segment
* tls_segment
,
705 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
706 elfcpp::Elf_types
<32>::Elf_Addr value
,
708 section_size_type view_size
);
710 // We need to keep track of which type of local dynamic relocation
711 // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
712 enum Local_dynamic_type
719 // This is set if we should skip the next reloc, which should be a
720 // PLT32 reloc against ___tls_get_addr.
721 bool skip_call_tls_get_addr_
;
722 // The type of local dynamic relocation we have seen in the section
723 // being relocated, if any.
724 Local_dynamic_type local_dynamic_type_
;
727 // A class which returns the size required for a relocation type,
728 // used while scanning relocs during a relocatable link.
729 class Relocatable_size_for_reloc
733 get_size_for_reloc(unsigned int, Relobj
*);
736 // Adjust TLS relocation type based on the options and whether this
737 // is a local symbol.
738 static tls::Tls_optimization
739 optimize_tls_reloc(bool is_final
, int r_type
);
741 // Check if relocation against this symbol is a candidate for
743 // mov foo@GOT(%reg), %reg
745 // lea foo@GOTOFF(%reg), %reg.
747 can_convert_mov_to_lea(const Symbol
* gsym
)
749 gold_assert(gsym
!= NULL
);
750 return (gsym
->type() != elfcpp::STT_GNU_IFUNC
751 && !gsym
->is_undefined ()
752 && !gsym
->is_from_dynobj()
753 && !gsym
->is_preemptible()
754 && (!parameters
->options().shared()
755 || (gsym
->visibility() != elfcpp::STV_DEFAULT
756 && gsym
->visibility() != elfcpp::STV_PROTECTED
)
757 || parameters
->options().Bsymbolic())
758 && strcmp(gsym
->name(), "_DYNAMIC") != 0);
761 // Get the GOT section, creating it if necessary.
762 Output_data_got
<32, false>*
763 got_section(Symbol_table
*, Layout
*);
765 // Get the GOT PLT section.
766 Output_data_got_plt_i386
*
767 got_plt_section() const
769 gold_assert(this->got_plt_
!= NULL
);
770 return this->got_plt_
;
773 // Get the GOT section for TLSDESC entries.
774 Output_data_got
<32, false>*
775 got_tlsdesc_section() const
777 gold_assert(this->got_tlsdesc_
!= NULL
);
778 return this->got_tlsdesc_
;
781 // Create the PLT section.
783 make_plt_section(Symbol_table
* symtab
, Layout
* layout
);
785 // Create a PLT entry for a global symbol.
787 make_plt_entry(Symbol_table
*, Layout
*, Symbol
*);
789 // Create a PLT entry for a local STT_GNU_IFUNC symbol.
791 make_local_ifunc_plt_entry(Symbol_table
*, Layout
*,
792 Sized_relobj_file
<32, false>* relobj
,
793 unsigned int local_sym_index
);
795 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
797 define_tls_base_symbol(Symbol_table
*, Layout
*);
799 // Create a GOT entry for the TLS module index.
801 got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
802 Sized_relobj_file
<32, false>* object
);
804 // Get the PLT section.
805 Output_data_plt_i386
*
808 gold_assert(this->plt_
!= NULL
);
812 // Get the dynamic reloc section, creating it if necessary.
814 rel_dyn_section(Layout
*);
816 // Get the section to use for TLS_DESC relocations.
818 rel_tls_desc_section(Layout
*) const;
820 // Get the section to use for IRELATIVE relocations.
822 rel_irelative_section(Layout
*);
824 // Add a potential copy relocation.
826 copy_reloc(Symbol_table
* symtab
, Layout
* layout
,
827 Sized_relobj_file
<32, false>* object
,
828 unsigned int shndx
, Output_section
* output_section
,
829 Symbol
* sym
, const elfcpp::Rel
<32, false>& reloc
)
831 this->copy_relocs_
.copy_reloc(symtab
, layout
,
832 symtab
->get_sized_symbol
<32>(sym
),
833 object
, shndx
, output_section
, reloc
,
834 this->rel_dyn_section(layout
));
837 // Information about this specific target which we pass to the
838 // general Target structure.
839 static const Target::Target_info i386_info
;
841 // The types of GOT entries needed for this platform.
842 // These values are exposed to the ABI in an incremental link.
843 // Do not renumber existing values without changing the version
844 // number of the .gnu_incremental_inputs section.
847 GOT_TYPE_STANDARD
= 0, // GOT entry for a regular symbol
848 GOT_TYPE_TLS_NOFFSET
= 1, // GOT entry for negative TLS offset
849 GOT_TYPE_TLS_OFFSET
= 2, // GOT entry for positive TLS offset
850 GOT_TYPE_TLS_PAIR
= 3, // GOT entry for TLS module/offset pair
851 GOT_TYPE_TLS_DESC
= 4 // GOT entry for TLS_DESC pair
855 Output_data_got
<32, false>* got_
;
857 Output_data_plt_i386
* plt_
;
858 // The GOT PLT section.
859 Output_data_got_plt_i386
* got_plt_
;
860 // The GOT section for IRELATIVE relocations.
861 Output_data_space
* got_irelative_
;
862 // The GOT section for TLSDESC relocations.
863 Output_data_got
<32, false>* got_tlsdesc_
;
864 // The _GLOBAL_OFFSET_TABLE_ symbol.
865 Symbol
* global_offset_table_
;
866 // The dynamic reloc section.
867 Reloc_section
* rel_dyn_
;
868 // The section to use for IRELATIVE relocs.
869 Reloc_section
* rel_irelative_
;
870 // Relocs saved to avoid a COPY reloc.
871 Copy_relocs
<elfcpp::SHT_REL
, 32, false> copy_relocs_
;
872 // Offset of the GOT entry for the TLS module index.
873 unsigned int got_mod_index_offset_
;
874 // True if the _TLS_MODULE_BASE_ symbol has been defined.
875 bool tls_base_symbol_defined_
;
878 const Target::Target_info
Target_i386::i386_info
=
881 false, // is_big_endian
882 elfcpp::EM_386
, // machine_code
883 false, // has_make_symbol
884 false, // has_resolve
885 true, // has_code_fill
886 true, // is_default_stack_executable
887 true, // can_icf_inline_merge_sections
889 "/usr/lib/libc.so.1", // dynamic_linker
890 0x08048000, // default_text_segment_address
891 0x1000, // abi_pagesize (overridable by -z max-page-size)
892 0x1000, // common_pagesize (overridable by -z common-page-size)
893 false, // isolate_execinstr
895 elfcpp::SHN_UNDEF
, // small_common_shndx
896 elfcpp::SHN_UNDEF
, // large_common_shndx
897 0, // small_common_section_flags
898 0, // large_common_section_flags
899 NULL
, // attributes_section
900 NULL
, // attributes_vendor
901 "_start" // entry_symbol_name
904 // Get the GOT section, creating it if necessary.
906 Output_data_got
<32, false>*
907 Target_i386::got_section(Symbol_table
* symtab
, Layout
* layout
)
909 if (this->got_
== NULL
)
911 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
913 this->got_
= new Output_data_got
<32, false>();
915 // When using -z now, we can treat .got.plt as a relro section.
916 // Without -z now, it is modified after program startup by lazy
918 bool is_got_plt_relro
= parameters
->options().now();
919 Output_section_order got_order
= (is_got_plt_relro
922 Output_section_order got_plt_order
= (is_got_plt_relro
924 : ORDER_NON_RELRO_FIRST
);
926 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
928 | elfcpp::SHF_WRITE
),
929 this->got_
, got_order
, true);
931 this->got_plt_
= new Output_data_got_plt_i386(layout
);
932 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
934 | elfcpp::SHF_WRITE
),
935 this->got_plt_
, got_plt_order
,
938 // The first three entries are reserved.
939 this->got_plt_
->set_current_data_size(3 * 4);
941 if (!is_got_plt_relro
)
943 // Those bytes can go into the relro segment.
944 layout
->increase_relro(3 * 4);
947 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
948 this->global_offset_table_
=
949 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
950 Symbol_table::PREDEFINED
,
952 0, 0, elfcpp::STT_OBJECT
,
954 elfcpp::STV_HIDDEN
, 0,
957 // If there are any IRELATIVE relocations, they get GOT entries
958 // in .got.plt after the jump slot relocations.
959 this->got_irelative_
= new Output_data_space(4, "** GOT IRELATIVE PLT");
960 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
962 | elfcpp::SHF_WRITE
),
963 this->got_irelative_
,
964 got_plt_order
, is_got_plt_relro
);
966 // If there are any TLSDESC relocations, they get GOT entries in
967 // .got.plt after the jump slot entries.
968 this->got_tlsdesc_
= new Output_data_got
<32, false>();
969 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
971 | elfcpp::SHF_WRITE
),
973 got_plt_order
, is_got_plt_relro
);
979 // Get the dynamic reloc section, creating it if necessary.
981 Target_i386::Reloc_section
*
982 Target_i386::rel_dyn_section(Layout
* layout
)
984 if (this->rel_dyn_
== NULL
)
986 gold_assert(layout
!= NULL
);
987 this->rel_dyn_
= new Reloc_section(parameters
->options().combreloc());
988 layout
->add_output_section_data(".rel.dyn", elfcpp::SHT_REL
,
989 elfcpp::SHF_ALLOC
, this->rel_dyn_
,
990 ORDER_DYNAMIC_RELOCS
, false);
992 return this->rel_dyn_
;
995 // Get the section to use for IRELATIVE relocs, creating it if
996 // necessary. These go in .rel.dyn, but only after all other dynamic
997 // relocations. They need to follow the other dynamic relocations so
998 // that they can refer to global variables initialized by those
1001 Target_i386::Reloc_section
*
1002 Target_i386::rel_irelative_section(Layout
* layout
)
1004 if (this->rel_irelative_
== NULL
)
1006 // Make sure we have already create the dynamic reloc section.
1007 this->rel_dyn_section(layout
);
1008 this->rel_irelative_
= new Reloc_section(false);
1009 layout
->add_output_section_data(".rel.dyn", elfcpp::SHT_REL
,
1010 elfcpp::SHF_ALLOC
, this->rel_irelative_
,
1011 ORDER_DYNAMIC_RELOCS
, false);
1012 gold_assert(this->rel_dyn_
->output_section()
1013 == this->rel_irelative_
->output_section());
1015 return this->rel_irelative_
;
1018 // Write the first three reserved words of the .got.plt section.
1019 // The remainder of the section is written while writing the PLT
1020 // in Output_data_plt_i386::do_write.
1023 Output_data_got_plt_i386::do_write(Output_file
* of
)
1025 // The first entry in the GOT is the address of the .dynamic section
1026 // aka the PT_DYNAMIC segment. The next two entries are reserved.
1027 // We saved space for them when we created the section in
1028 // Target_i386::got_section.
1029 const off_t got_file_offset
= this->offset();
1030 gold_assert(this->data_size() >= 12);
1031 unsigned char* const got_view
= of
->get_output_view(got_file_offset
, 12);
1032 Output_section
* dynamic
= this->layout_
->dynamic_section();
1033 uint32_t dynamic_addr
= dynamic
== NULL
? 0 : dynamic
->address();
1034 elfcpp::Swap
<32, false>::writeval(got_view
, dynamic_addr
);
1035 memset(got_view
+ 4, 0, 8);
1036 of
->write_output_view(got_file_offset
, 12, got_view
);
1039 // Create the PLT section. The ordinary .got section is an argument,
1040 // since we need to refer to the start. We also create our own .got
1041 // section just for PLT entries.
1043 Output_data_plt_i386::Output_data_plt_i386(Layout
* layout
,
1045 Output_data_got_plt_i386
* got_plt
,
1046 Output_data_space
* got_irelative
)
1047 : Output_section_data(addralign
),
1048 tls_desc_rel_(NULL
), irelative_rel_(NULL
), got_plt_(got_plt
),
1049 got_irelative_(got_irelative
), count_(0), irelative_count_(0),
1050 global_ifuncs_(), local_ifuncs_()
1052 this->rel_
= new Reloc_section(false);
1053 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
1054 elfcpp::SHF_ALLOC
, this->rel_
,
1055 ORDER_DYNAMIC_PLT_RELOCS
, false);
1059 Output_data_plt_i386::do_adjust_output_section(Output_section
* os
)
1061 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
1062 // linker, and so do we.
1066 // Add an entry to the PLT.
1069 Output_data_plt_i386::add_entry(Symbol_table
* symtab
, Layout
* layout
,
1072 gold_assert(!gsym
->has_plt_offset());
1074 // Every PLT entry needs a reloc.
1075 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1076 && gsym
->can_use_relative_reloc(false))
1078 gsym
->set_plt_offset(this->irelative_count_
* this->get_plt_entry_size());
1079 ++this->irelative_count_
;
1080 section_offset_type got_offset
=
1081 this->got_irelative_
->current_data_size();
1082 this->got_irelative_
->set_current_data_size(got_offset
+ 4);
1083 Reloc_section
* rel
= this->rel_irelative(symtab
, layout
);
1084 rel
->add_symbolless_global_addend(gsym
, elfcpp::R_386_IRELATIVE
,
1085 this->got_irelative_
, got_offset
);
1086 struct Global_ifunc gi
;
1088 gi
.got_offset
= got_offset
;
1089 this->global_ifuncs_
.push_back(gi
);
1093 // When setting the PLT offset we skip the initial reserved PLT
1095 gsym
->set_plt_offset((this->count_
+ 1) * this->get_plt_entry_size());
1099 section_offset_type got_offset
= this->got_plt_
->current_data_size();
1101 // Every PLT entry needs a GOT entry which points back to the
1102 // PLT entry (this will be changed by the dynamic linker,
1103 // normally lazily when the function is called).
1104 this->got_plt_
->set_current_data_size(got_offset
+ 4);
1106 gsym
->set_needs_dynsym_entry();
1107 this->rel_
->add_global(gsym
, elfcpp::R_386_JUMP_SLOT
, this->got_plt_
,
1111 // Note that we don't need to save the symbol. The contents of the
1112 // PLT are independent of which symbols are used. The symbols only
1113 // appear in the relocations.
1116 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
1120 Output_data_plt_i386::add_local_ifunc_entry(
1121 Symbol_table
* symtab
,
1123 Sized_relobj_file
<32, false>* relobj
,
1124 unsigned int local_sym_index
)
1126 unsigned int plt_offset
= this->irelative_count_
* this->get_plt_entry_size();
1127 ++this->irelative_count_
;
1129 section_offset_type got_offset
= this->got_irelative_
->current_data_size();
1131 // Every PLT entry needs a GOT entry which points back to the PLT
1133 this->got_irelative_
->set_current_data_size(got_offset
+ 4);
1135 // Every PLT entry needs a reloc.
1136 Reloc_section
* rel
= this->rel_irelative(symtab
, layout
);
1137 rel
->add_symbolless_local_addend(relobj
, local_sym_index
,
1138 elfcpp::R_386_IRELATIVE
,
1139 this->got_irelative_
, got_offset
);
1141 struct Local_ifunc li
;
1143 li
.local_sym_index
= local_sym_index
;
1144 li
.got_offset
= got_offset
;
1145 this->local_ifuncs_
.push_back(li
);
1150 // Return where the TLS_DESC relocations should go, creating it if
1151 // necessary. These follow the JUMP_SLOT relocations.
1153 Output_data_plt_i386::Reloc_section
*
1154 Output_data_plt_i386::rel_tls_desc(Layout
* layout
)
1156 if (this->tls_desc_rel_
== NULL
)
1158 this->tls_desc_rel_
= new Reloc_section(false);
1159 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
1160 elfcpp::SHF_ALLOC
, this->tls_desc_rel_
,
1161 ORDER_DYNAMIC_PLT_RELOCS
, false);
1162 gold_assert(this->tls_desc_rel_
->output_section()
1163 == this->rel_
->output_section());
1165 return this->tls_desc_rel_
;
1168 // Return where the IRELATIVE relocations should go in the PLT. These
1169 // follow the JUMP_SLOT and TLS_DESC relocations.
1171 Output_data_plt_i386::Reloc_section
*
1172 Output_data_plt_i386::rel_irelative(Symbol_table
* symtab
, Layout
* layout
)
1174 if (this->irelative_rel_
== NULL
)
1176 // Make sure we have a place for the TLS_DESC relocations, in
1177 // case we see any later on.
1178 this->rel_tls_desc(layout
);
1179 this->irelative_rel_
= new Reloc_section(false);
1180 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
1181 elfcpp::SHF_ALLOC
, this->irelative_rel_
,
1182 ORDER_DYNAMIC_PLT_RELOCS
, false);
1183 gold_assert(this->irelative_rel_
->output_section()
1184 == this->rel_
->output_section());
1186 if (parameters
->doing_static_link())
1188 // A statically linked executable will only have a .rel.plt
1189 // section to hold R_386_IRELATIVE relocs for STT_GNU_IFUNC
1190 // symbols. The library will use these symbols to locate
1191 // the IRELATIVE relocs at program startup time.
1192 symtab
->define_in_output_data("__rel_iplt_start", NULL
,
1193 Symbol_table::PREDEFINED
,
1194 this->irelative_rel_
, 0, 0,
1195 elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
1196 elfcpp::STV_HIDDEN
, 0, false, true);
1197 symtab
->define_in_output_data("__rel_iplt_end", NULL
,
1198 Symbol_table::PREDEFINED
,
1199 this->irelative_rel_
, 0, 0,
1200 elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
1201 elfcpp::STV_HIDDEN
, 0, true, true);
1204 return this->irelative_rel_
;
1207 // Return the PLT address to use for a global symbol.
1210 Output_data_plt_i386::address_for_global(const Symbol
* gsym
)
1212 uint64_t offset
= 0;
1213 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1214 && gsym
->can_use_relative_reloc(false))
1215 offset
= (this->count_
+ 1) * this->get_plt_entry_size();
1216 return this->address() + offset
+ gsym
->plt_offset();
1219 // Return the PLT address to use for a local symbol. These are always
1220 // IRELATIVE relocs.
1223 Output_data_plt_i386::address_for_local(const Relobj
* object
,
1226 return (this->address()
1227 + (this->count_
+ 1) * this->get_plt_entry_size()
1228 + object
->local_plt_offset(r_sym
));
1231 // The first entry in the PLT for an executable.
1233 const unsigned char Output_data_plt_i386_exec::first_plt_entry
[plt_entry_size
] =
1235 0xff, 0x35, // pushl contents of memory address
1236 0, 0, 0, 0, // replaced with address of .got + 4
1237 0xff, 0x25, // jmp indirect
1238 0, 0, 0, 0, // replaced with address of .got + 8
1239 0, 0, 0, 0 // unused
1243 Output_data_plt_i386_exec::do_fill_first_plt_entry(
1245 elfcpp::Elf_types
<32>::Elf_Addr got_address
)
1247 memcpy(pov
, first_plt_entry
, plt_entry_size
);
1248 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 4);
1249 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 8);
1252 // The first entry in the PLT for a shared object.
1254 const unsigned char Output_data_plt_i386_dyn::first_plt_entry
[plt_entry_size
] =
1256 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
1257 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
1258 0, 0, 0, 0 // unused
1262 Output_data_plt_i386_dyn::do_fill_first_plt_entry(
1264 elfcpp::Elf_types
<32>::Elf_Addr
)
1266 memcpy(pov
, first_plt_entry
, plt_entry_size
);
1269 // Subsequent entries in the PLT for an executable.
1271 const unsigned char Output_data_plt_i386_exec::plt_entry
[plt_entry_size
] =
1273 0xff, 0x25, // jmp indirect
1274 0, 0, 0, 0, // replaced with address of symbol in .got
1275 0x68, // pushl immediate
1276 0, 0, 0, 0, // replaced with offset into relocation table
1277 0xe9, // jmp relative
1278 0, 0, 0, 0 // replaced with offset to start of .plt
1282 Output_data_plt_i386_exec::do_fill_plt_entry(
1284 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
1285 unsigned int got_offset
,
1286 unsigned int plt_offset
,
1287 unsigned int plt_rel_offset
)
1289 memcpy(pov
, plt_entry
, plt_entry_size
);
1290 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
1291 got_address
+ got_offset
);
1292 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_rel_offset
);
1293 elfcpp::Swap
<32, false>::writeval(pov
+ 12, - (plt_offset
+ 12 + 4));
1297 // Subsequent entries in the PLT for a shared object.
1299 const unsigned char Output_data_plt_i386_dyn::plt_entry
[plt_entry_size
] =
1301 0xff, 0xa3, // jmp *offset(%ebx)
1302 0, 0, 0, 0, // replaced with offset of symbol in .got
1303 0x68, // pushl immediate
1304 0, 0, 0, 0, // replaced with offset into relocation table
1305 0xe9, // jmp relative
1306 0, 0, 0, 0 // replaced with offset to start of .plt
1310 Output_data_plt_i386_dyn::do_fill_plt_entry(unsigned char* pov
,
1311 elfcpp::Elf_types
<32>::Elf_Addr
,
1312 unsigned int got_offset
,
1313 unsigned int plt_offset
,
1314 unsigned int plt_rel_offset
)
1316 memcpy(pov
, plt_entry
, plt_entry_size
);
1317 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
1318 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_rel_offset
);
1319 elfcpp::Swap
<32, false>::writeval(pov
+ 12, - (plt_offset
+ 12 + 4));
1323 // The .eh_frame unwind information for the PLT.
1326 Output_data_plt_i386::plt_eh_frame_cie
[plt_eh_frame_cie_size
] =
1329 'z', // Augmentation: augmentation size included.
1330 'R', // Augmentation: FDE encoding included.
1331 '\0', // End of augmentation string.
1332 1, // Code alignment factor.
1333 0x7c, // Data alignment factor.
1334 8, // Return address column.
1335 1, // Augmentation size.
1336 (elfcpp::DW_EH_PE_pcrel
// FDE encoding.
1337 | elfcpp::DW_EH_PE_sdata4
),
1338 elfcpp::DW_CFA_def_cfa
, 4, 4, // DW_CFA_def_cfa: r4 (esp) ofs 4.
1339 elfcpp::DW_CFA_offset
+ 8, 1, // DW_CFA_offset: r8 (eip) at cfa-4.
1340 elfcpp::DW_CFA_nop
, // Align to 16 bytes.
1345 Output_data_plt_i386_standard::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
1347 0, 0, 0, 0, // Replaced with offset to .plt.
1348 0, 0, 0, 0, // Replaced with size of .plt.
1349 0, // Augmentation size.
1350 elfcpp::DW_CFA_def_cfa_offset
, 8, // DW_CFA_def_cfa_offset: 8.
1351 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
1352 elfcpp::DW_CFA_def_cfa_offset
, 12, // DW_CFA_def_cfa_offset: 12.
1353 elfcpp::DW_CFA_advance_loc
+ 10, // Advance 10 to __PLT__ + 16.
1354 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
1355 11, // Block length.
1356 elfcpp::DW_OP_breg4
, 4, // Push %esp + 4.
1357 elfcpp::DW_OP_breg8
, 0, // Push %eip.
1358 elfcpp::DW_OP_lit15
, // Push 0xf.
1359 elfcpp::DW_OP_and
, // & (%eip & 0xf).
1360 elfcpp::DW_OP_lit11
, // Push 0xb.
1361 elfcpp::DW_OP_ge
, // >= ((%eip & 0xf) >= 0xb)
1362 elfcpp::DW_OP_lit2
, // Push 2.
1363 elfcpp::DW_OP_shl
, // << (((%eip & 0xf) >= 0xb) << 2)
1364 elfcpp::DW_OP_plus
, // + ((((%eip&0xf)>=0xb)<<2)+%esp+4
1365 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
1371 // Write out the PLT. This uses the hand-coded instructions above,
1372 // and adjusts them as needed. This is all specified by the i386 ELF
1373 // Processor Supplement.
1376 Output_data_plt_i386::do_write(Output_file
* of
)
1378 const off_t offset
= this->offset();
1379 const section_size_type oview_size
=
1380 convert_to_section_size_type(this->data_size());
1381 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
1383 const off_t got_file_offset
= this->got_plt_
->offset();
1384 gold_assert(parameters
->incremental_update()
1385 || (got_file_offset
+ this->got_plt_
->data_size()
1386 == this->got_irelative_
->offset()));
1387 const section_size_type got_size
=
1388 convert_to_section_size_type(this->got_plt_
->data_size()
1389 + this->got_irelative_
->data_size());
1391 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
1394 unsigned char* pov
= oview
;
1396 elfcpp::Elf_types
<32>::Elf_Addr plt_address
= this->address();
1397 elfcpp::Elf_types
<32>::Elf_Addr got_address
= this->got_plt_
->address();
1399 this->fill_first_plt_entry(pov
, got_address
);
1400 pov
+= this->get_plt_entry_size();
1402 // The first three entries in the GOT are reserved, and are written
1403 // by Output_data_got_plt_i386::do_write.
1404 unsigned char* got_pov
= got_view
+ 12;
1406 const int rel_size
= elfcpp::Elf_sizes
<32>::rel_size
;
1408 unsigned int plt_offset
= this->get_plt_entry_size();
1409 unsigned int plt_rel_offset
= 0;
1410 unsigned int got_offset
= 12;
1411 const unsigned int count
= this->count_
+ this->irelative_count_
;
1412 for (unsigned int i
= 0;
1415 pov
+= this->get_plt_entry_size(),
1417 plt_offset
+= this->get_plt_entry_size(),
1418 plt_rel_offset
+= rel_size
,
1421 // Set and adjust the PLT entry itself.
1422 unsigned int lazy_offset
= this->fill_plt_entry(pov
,
1428 // Set the entry in the GOT.
1429 elfcpp::Swap
<32, false>::writeval(got_pov
,
1430 plt_address
+ plt_offset
+ lazy_offset
);
1433 // If any STT_GNU_IFUNC symbols have PLT entries, we need to change
1434 // the GOT to point to the actual symbol value, rather than point to
1435 // the PLT entry. That will let the dynamic linker call the right
1436 // function when resolving IRELATIVE relocations.
1437 unsigned char* got_irelative_view
= got_view
+ this->got_plt_
->data_size();
1438 for (std::vector
<Global_ifunc
>::const_iterator p
=
1439 this->global_ifuncs_
.begin();
1440 p
!= this->global_ifuncs_
.end();
1443 const Sized_symbol
<32>* ssym
=
1444 static_cast<const Sized_symbol
<32>*>(p
->sym
);
1445 elfcpp::Swap
<32, false>::writeval(got_irelative_view
+ p
->got_offset
,
1449 for (std::vector
<Local_ifunc
>::const_iterator p
=
1450 this->local_ifuncs_
.begin();
1451 p
!= this->local_ifuncs_
.end();
1454 const Symbol_value
<32>* psymval
=
1455 p
->object
->local_symbol(p
->local_sym_index
);
1456 elfcpp::Swap
<32, false>::writeval(got_irelative_view
+ p
->got_offset
,
1457 psymval
->value(p
->object
, 0));
1460 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
1461 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
1463 of
->write_output_view(offset
, oview_size
, oview
);
1464 of
->write_output_view(got_file_offset
, got_size
, got_view
);
1467 // Create the PLT section.
1470 Target_i386::make_plt_section(Symbol_table
* symtab
, Layout
* layout
)
1472 if (this->plt_
== NULL
)
1474 // Create the GOT sections first.
1475 this->got_section(symtab
, layout
);
1477 const bool dyn
= parameters
->options().output_is_position_independent();
1478 this->plt_
= this->make_data_plt(layout
,
1480 this->got_irelative_
,
1483 // Add unwind information if requested.
1484 if (parameters
->options().ld_generated_unwind_info())
1485 this->plt_
->add_eh_frame(layout
);
1487 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
1489 | elfcpp::SHF_EXECINSTR
),
1490 this->plt_
, ORDER_PLT
, false);
1492 // Make the sh_info field of .rel.plt point to .plt.
1493 Output_section
* rel_plt_os
= this->plt_
->rel_plt()->output_section();
1494 rel_plt_os
->set_info_section(this->plt_
->output_section());
1498 // Create a PLT entry for a global symbol.
1501 Target_i386::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
, Symbol
* gsym
)
1503 if (gsym
->has_plt_offset())
1505 if (this->plt_
== NULL
)
1506 this->make_plt_section(symtab
, layout
);
1507 this->plt_
->add_entry(symtab
, layout
, gsym
);
1510 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1513 Target_i386::make_local_ifunc_plt_entry(Symbol_table
* symtab
, Layout
* layout
,
1514 Sized_relobj_file
<32, false>* relobj
,
1515 unsigned int local_sym_index
)
1517 if (relobj
->local_has_plt_offset(local_sym_index
))
1519 if (this->plt_
== NULL
)
1520 this->make_plt_section(symtab
, layout
);
1521 unsigned int plt_offset
= this->plt_
->add_local_ifunc_entry(symtab
, layout
,
1524 relobj
->set_local_plt_offset(local_sym_index
, plt_offset
);
1527 // Return the number of entries in the PLT.
1530 Target_i386::plt_entry_count() const
1532 if (this->plt_
== NULL
)
1534 return this->plt_
->entry_count();
1537 // Return the offset of the first non-reserved PLT entry.
1540 Target_i386::first_plt_entry_offset() const
1542 return this->plt_
->first_plt_entry_offset();
1545 // Return the size of each PLT entry.
1548 Target_i386::plt_entry_size() const
1550 return this->plt_
->get_plt_entry_size();
1553 // Get the section to use for TLS_DESC relocations.
1555 Target_i386::Reloc_section
*
1556 Target_i386::rel_tls_desc_section(Layout
* layout
) const
1558 return this->plt_section()->rel_tls_desc(layout
);
1561 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1564 Target_i386::define_tls_base_symbol(Symbol_table
* symtab
, Layout
* layout
)
1566 if (this->tls_base_symbol_defined_
)
1569 Output_segment
* tls_segment
= layout
->tls_segment();
1570 if (tls_segment
!= NULL
)
1572 bool is_exec
= parameters
->options().output_is_executable();
1573 symtab
->define_in_output_segment("_TLS_MODULE_BASE_", NULL
,
1574 Symbol_table::PREDEFINED
,
1578 elfcpp::STV_HIDDEN
, 0,
1580 ? Symbol::SEGMENT_END
1581 : Symbol::SEGMENT_START
),
1584 this->tls_base_symbol_defined_
= true;
1587 // Create a GOT entry for the TLS module index.
1590 Target_i386::got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
1591 Sized_relobj_file
<32, false>* object
)
1593 if (this->got_mod_index_offset_
== -1U)
1595 gold_assert(symtab
!= NULL
&& layout
!= NULL
&& object
!= NULL
);
1596 Reloc_section
* rel_dyn
= this->rel_dyn_section(layout
);
1597 Output_data_got
<32, false>* got
= this->got_section(symtab
, layout
);
1598 unsigned int got_offset
= got
->add_constant(0);
1599 rel_dyn
->add_local(object
, 0, elfcpp::R_386_TLS_DTPMOD32
, got
,
1601 got
->add_constant(0);
1602 this->got_mod_index_offset_
= got_offset
;
1604 return this->got_mod_index_offset_
;
1607 // Optimize the TLS relocation type based on what we know about the
1608 // symbol. IS_FINAL is true if the final address of this symbol is
1609 // known at link time.
1611 tls::Tls_optimization
1612 Target_i386::optimize_tls_reloc(bool is_final
, int r_type
)
1614 // If we are generating a shared library, then we can't do anything
1616 if (parameters
->options().shared())
1617 return tls::TLSOPT_NONE
;
1621 case elfcpp::R_386_TLS_GD
:
1622 case elfcpp::R_386_TLS_GOTDESC
:
1623 case elfcpp::R_386_TLS_DESC_CALL
:
1624 // These are General-Dynamic which permits fully general TLS
1625 // access. Since we know that we are generating an executable,
1626 // we can convert this to Initial-Exec. If we also know that
1627 // this is a local symbol, we can further switch to Local-Exec.
1629 return tls::TLSOPT_TO_LE
;
1630 return tls::TLSOPT_TO_IE
;
1632 case elfcpp::R_386_TLS_LDM
:
1633 // This is Local-Dynamic, which refers to a local symbol in the
1634 // dynamic TLS block. Since we know that we generating an
1635 // executable, we can switch to Local-Exec.
1636 return tls::TLSOPT_TO_LE
;
1638 case elfcpp::R_386_TLS_LDO_32
:
1639 // Another type of Local-Dynamic relocation.
1640 return tls::TLSOPT_TO_LE
;
1642 case elfcpp::R_386_TLS_IE
:
1643 case elfcpp::R_386_TLS_GOTIE
:
1644 case elfcpp::R_386_TLS_IE_32
:
1645 // These are Initial-Exec relocs which get the thread offset
1646 // from the GOT. If we know that we are linking against the
1647 // local symbol, we can switch to Local-Exec, which links the
1648 // thread offset into the instruction.
1650 return tls::TLSOPT_TO_LE
;
1651 return tls::TLSOPT_NONE
;
1653 case elfcpp::R_386_TLS_LE
:
1654 case elfcpp::R_386_TLS_LE_32
:
1655 // When we already have Local-Exec, there is nothing further we
1657 return tls::TLSOPT_NONE
;
1664 // Get the Reference_flags for a particular relocation.
1667 Target_i386::Scan::get_reference_flags(unsigned int r_type
)
1671 case elfcpp::R_386_NONE
:
1672 case elfcpp::R_386_GNU_VTINHERIT
:
1673 case elfcpp::R_386_GNU_VTENTRY
:
1674 case elfcpp::R_386_GOTPC
:
1675 // No symbol reference.
1678 case elfcpp::R_386_32
:
1679 case elfcpp::R_386_16
:
1680 case elfcpp::R_386_8
:
1681 return Symbol::ABSOLUTE_REF
;
1683 case elfcpp::R_386_PC32
:
1684 case elfcpp::R_386_PC16
:
1685 case elfcpp::R_386_PC8
:
1686 case elfcpp::R_386_GOTOFF
:
1687 return Symbol::RELATIVE_REF
;
1689 case elfcpp::R_386_PLT32
:
1690 return Symbol::FUNCTION_CALL
| Symbol::RELATIVE_REF
;
1692 case elfcpp::R_386_GOT32
:
1693 case elfcpp::R_386_GOT32X
:
1695 return Symbol::ABSOLUTE_REF
;
1697 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1698 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1699 case elfcpp::R_386_TLS_DESC_CALL
:
1700 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1701 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1702 case elfcpp::R_386_TLS_IE
: // Initial-exec
1703 case elfcpp::R_386_TLS_IE_32
:
1704 case elfcpp::R_386_TLS_GOTIE
:
1705 case elfcpp::R_386_TLS_LE
: // Local-exec
1706 case elfcpp::R_386_TLS_LE_32
:
1707 return Symbol::TLS_REF
;
1709 case elfcpp::R_386_COPY
:
1710 case elfcpp::R_386_GLOB_DAT
:
1711 case elfcpp::R_386_JUMP_SLOT
:
1712 case elfcpp::R_386_RELATIVE
:
1713 case elfcpp::R_386_IRELATIVE
:
1714 case elfcpp::R_386_TLS_TPOFF
:
1715 case elfcpp::R_386_TLS_DTPMOD32
:
1716 case elfcpp::R_386_TLS_DTPOFF32
:
1717 case elfcpp::R_386_TLS_TPOFF32
:
1718 case elfcpp::R_386_TLS_DESC
:
1719 case elfcpp::R_386_32PLT
:
1720 case elfcpp::R_386_TLS_GD_32
:
1721 case elfcpp::R_386_TLS_GD_PUSH
:
1722 case elfcpp::R_386_TLS_GD_CALL
:
1723 case elfcpp::R_386_TLS_GD_POP
:
1724 case elfcpp::R_386_TLS_LDM_32
:
1725 case elfcpp::R_386_TLS_LDM_PUSH
:
1726 case elfcpp::R_386_TLS_LDM_CALL
:
1727 case elfcpp::R_386_TLS_LDM_POP
:
1728 case elfcpp::R_386_USED_BY_INTEL_200
:
1730 // Not expected. We will give an error later.
1735 // Report an unsupported relocation against a local symbol.
1738 Target_i386::Scan::unsupported_reloc_local(Sized_relobj_file
<32, false>* object
,
1739 unsigned int r_type
)
1741 gold_error(_("%s: unsupported reloc %u against local symbol"),
1742 object
->name().c_str(), r_type
);
1745 // Return whether we need to make a PLT entry for a relocation of a
1746 // given type against a STT_GNU_IFUNC symbol.
1749 Target_i386::Scan::reloc_needs_plt_for_ifunc(
1750 Sized_relobj_file
<32, false>* object
,
1751 unsigned int r_type
)
1753 int flags
= Scan::get_reference_flags(r_type
);
1754 if (flags
& Symbol::TLS_REF
)
1755 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
1756 object
->name().c_str(), r_type
);
1760 // Scan a relocation for a local symbol.
1763 Target_i386::Scan::local(Symbol_table
* symtab
,
1765 Target_i386
* target
,
1766 Sized_relobj_file
<32, false>* object
,
1767 unsigned int data_shndx
,
1768 Output_section
* output_section
,
1769 const elfcpp::Rel
<32, false>& reloc
,
1770 unsigned int r_type
,
1771 const elfcpp::Sym
<32, false>& lsym
,
1777 // A local STT_GNU_IFUNC symbol may require a PLT entry.
1778 if (lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
1779 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
1781 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1782 target
->make_local_ifunc_plt_entry(symtab
, layout
, object
, r_sym
);
1787 case elfcpp::R_386_NONE
:
1788 case elfcpp::R_386_GNU_VTINHERIT
:
1789 case elfcpp::R_386_GNU_VTENTRY
:
1792 case elfcpp::R_386_32
:
1793 // If building a shared library (or a position-independent
1794 // executable), we need to create a dynamic relocation for
1795 // this location. The relocation applied at link time will
1796 // apply the link-time value, so we flag the location with
1797 // an R_386_RELATIVE relocation so the dynamic loader can
1798 // relocate it easily.
1799 if (parameters
->options().output_is_position_independent())
1801 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1802 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1803 rel_dyn
->add_local_relative(object
, r_sym
, elfcpp::R_386_RELATIVE
,
1804 output_section
, data_shndx
,
1805 reloc
.get_r_offset());
1809 case elfcpp::R_386_16
:
1810 case elfcpp::R_386_8
:
1811 // If building a shared library (or a position-independent
1812 // executable), we need to create a dynamic relocation for
1813 // this location. Because the addend needs to remain in the
1814 // data section, we need to be careful not to apply this
1815 // relocation statically.
1816 if (parameters
->options().output_is_position_independent())
1818 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1819 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1820 if (lsym
.get_st_type() != elfcpp::STT_SECTION
)
1821 rel_dyn
->add_local(object
, r_sym
, r_type
, output_section
,
1822 data_shndx
, reloc
.get_r_offset());
1825 gold_assert(lsym
.get_st_value() == 0);
1826 unsigned int shndx
= lsym
.get_st_shndx();
1828 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
,
1831 object
->error(_("section symbol %u has bad shndx %u"),
1834 rel_dyn
->add_local_section(object
, shndx
,
1835 r_type
, output_section
,
1836 data_shndx
, reloc
.get_r_offset());
1841 case elfcpp::R_386_PC32
:
1842 case elfcpp::R_386_PC16
:
1843 case elfcpp::R_386_PC8
:
1846 case elfcpp::R_386_PLT32
:
1847 // Since we know this is a local symbol, we can handle this as a
1851 case elfcpp::R_386_GOTOFF
:
1852 case elfcpp::R_386_GOTPC
:
1853 // We need a GOT section.
1854 target
->got_section(symtab
, layout
);
1857 case elfcpp::R_386_GOT32
:
1858 case elfcpp::R_386_GOT32X
:
1860 // We need GOT section.
1861 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
1863 // If the relocation symbol isn't IFUNC,
1864 // and is local, then we will convert
1865 // mov foo@GOT(%reg), %reg
1867 // lea foo@GOTOFF(%reg), %reg
1868 // in Relocate::relocate.
1869 if (reloc
.get_r_offset() >= 2
1870 && lsym
.get_st_type() != elfcpp::STT_GNU_IFUNC
)
1872 section_size_type stype
;
1873 const unsigned char* view
= object
->section_contents(data_shndx
,
1875 if (view
[reloc
.get_r_offset() - 2] == 0x8b)
1879 // Otherwise, the symbol requires a GOT entry.
1880 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1882 // For a STT_GNU_IFUNC symbol we want the PLT offset. That
1883 // lets function pointers compare correctly with shared
1884 // libraries. Otherwise we would need an IRELATIVE reloc.
1886 if (lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
)
1887 is_new
= got
->add_local_plt(object
, r_sym
, GOT_TYPE_STANDARD
);
1889 is_new
= got
->add_local(object
, r_sym
, GOT_TYPE_STANDARD
);
1892 // If we are generating a shared object, we need to add a
1893 // dynamic RELATIVE relocation for this symbol's GOT entry.
1894 if (parameters
->options().output_is_position_independent())
1896 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1897 unsigned int got_offset
=
1898 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
);
1899 rel_dyn
->add_local_relative(object
, r_sym
,
1900 elfcpp::R_386_RELATIVE
,
1907 // These are relocations which should only be seen by the
1908 // dynamic linker, and should never be seen here.
1909 case elfcpp::R_386_COPY
:
1910 case elfcpp::R_386_GLOB_DAT
:
1911 case elfcpp::R_386_JUMP_SLOT
:
1912 case elfcpp::R_386_RELATIVE
:
1913 case elfcpp::R_386_IRELATIVE
:
1914 case elfcpp::R_386_TLS_TPOFF
:
1915 case elfcpp::R_386_TLS_DTPMOD32
:
1916 case elfcpp::R_386_TLS_DTPOFF32
:
1917 case elfcpp::R_386_TLS_TPOFF32
:
1918 case elfcpp::R_386_TLS_DESC
:
1919 gold_error(_("%s: unexpected reloc %u in object file"),
1920 object
->name().c_str(), r_type
);
1923 // These are initial TLS relocs, which are expected when
1925 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1926 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1927 case elfcpp::R_386_TLS_DESC_CALL
:
1928 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1929 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1930 case elfcpp::R_386_TLS_IE
: // Initial-exec
1931 case elfcpp::R_386_TLS_IE_32
:
1932 case elfcpp::R_386_TLS_GOTIE
:
1933 case elfcpp::R_386_TLS_LE
: // Local-exec
1934 case elfcpp::R_386_TLS_LE_32
:
1936 bool output_is_shared
= parameters
->options().shared();
1937 const tls::Tls_optimization optimized_type
1938 = Target_i386::optimize_tls_reloc(!output_is_shared
, r_type
);
1941 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1942 if (optimized_type
== tls::TLSOPT_NONE
)
1944 // Create a pair of GOT entries for the module index and
1945 // dtv-relative offset.
1946 Output_data_got
<32, false>* got
1947 = target
->got_section(symtab
, layout
);
1948 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1949 unsigned int shndx
= lsym
.get_st_shndx();
1951 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
1953 object
->error(_("local symbol %u has bad shndx %u"),
1956 got
->add_local_pair_with_rel(object
, r_sym
, shndx
,
1958 target
->rel_dyn_section(layout
),
1959 elfcpp::R_386_TLS_DTPMOD32
);
1961 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1962 unsupported_reloc_local(object
, r_type
);
1965 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva)
1966 target
->define_tls_base_symbol(symtab
, layout
);
1967 if (optimized_type
== tls::TLSOPT_NONE
)
1969 // Create a double GOT entry with an R_386_TLS_DESC
1970 // reloc. The R_386_TLS_DESC reloc is resolved
1971 // lazily, so the GOT entry needs to be in an area in
1972 // .got.plt, not .got. Call got_section to make sure
1973 // the section has been created.
1974 target
->got_section(symtab
, layout
);
1975 Output_data_got
<32, false>* got
= target
->got_tlsdesc_section();
1976 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1977 if (!object
->local_has_got_offset(r_sym
, GOT_TYPE_TLS_DESC
))
1979 unsigned int got_offset
= got
->add_constant(0);
1980 // The local symbol value is stored in the second
1982 got
->add_local(object
, r_sym
, GOT_TYPE_TLS_DESC
);
1983 // That set the GOT offset of the local symbol to
1984 // point to the second entry, but we want it to
1985 // point to the first.
1986 object
->set_local_got_offset(r_sym
, GOT_TYPE_TLS_DESC
,
1988 Reloc_section
* rt
= target
->rel_tls_desc_section(layout
);
1989 rt
->add_absolute(elfcpp::R_386_TLS_DESC
, got
, got_offset
);
1992 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1993 unsupported_reloc_local(object
, r_type
);
1996 case elfcpp::R_386_TLS_DESC_CALL
:
1999 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2000 if (optimized_type
== tls::TLSOPT_NONE
)
2002 // Create a GOT entry for the module index.
2003 target
->got_mod_index_entry(symtab
, layout
, object
);
2005 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2006 unsupported_reloc_local(object
, r_type
);
2009 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2012 case elfcpp::R_386_TLS_IE
: // Initial-exec
2013 case elfcpp::R_386_TLS_IE_32
:
2014 case elfcpp::R_386_TLS_GOTIE
:
2015 layout
->set_has_static_tls();
2016 if (optimized_type
== tls::TLSOPT_NONE
)
2018 // For the R_386_TLS_IE relocation, we need to create a
2019 // dynamic relocation when building a shared library.
2020 if (r_type
== elfcpp::R_386_TLS_IE
2021 && parameters
->options().shared())
2023 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2025 = elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
2026 rel_dyn
->add_local_relative(object
, r_sym
,
2027 elfcpp::R_386_RELATIVE
,
2028 output_section
, data_shndx
,
2029 reloc
.get_r_offset());
2031 // Create a GOT entry for the tp-relative offset.
2032 Output_data_got
<32, false>* got
2033 = target
->got_section(symtab
, layout
);
2034 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
2035 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2036 ? elfcpp::R_386_TLS_TPOFF32
2037 : elfcpp::R_386_TLS_TPOFF
);
2038 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2039 ? GOT_TYPE_TLS_OFFSET
2040 : GOT_TYPE_TLS_NOFFSET
);
2041 got
->add_local_with_rel(object
, r_sym
, got_type
,
2042 target
->rel_dyn_section(layout
),
2045 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2046 unsupported_reloc_local(object
, r_type
);
2049 case elfcpp::R_386_TLS_LE
: // Local-exec
2050 case elfcpp::R_386_TLS_LE_32
:
2051 layout
->set_has_static_tls();
2052 if (output_is_shared
)
2054 // We need to create a dynamic relocation.
2055 gold_assert(lsym
.get_st_type() != elfcpp::STT_SECTION
);
2056 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
2057 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
2058 ? elfcpp::R_386_TLS_TPOFF32
2059 : elfcpp::R_386_TLS_TPOFF
);
2060 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2061 rel_dyn
->add_local(object
, r_sym
, dyn_r_type
, output_section
,
2062 data_shndx
, reloc
.get_r_offset());
2072 case elfcpp::R_386_32PLT
:
2073 case elfcpp::R_386_TLS_GD_32
:
2074 case elfcpp::R_386_TLS_GD_PUSH
:
2075 case elfcpp::R_386_TLS_GD_CALL
:
2076 case elfcpp::R_386_TLS_GD_POP
:
2077 case elfcpp::R_386_TLS_LDM_32
:
2078 case elfcpp::R_386_TLS_LDM_PUSH
:
2079 case elfcpp::R_386_TLS_LDM_CALL
:
2080 case elfcpp::R_386_TLS_LDM_POP
:
2081 case elfcpp::R_386_USED_BY_INTEL_200
:
2083 unsupported_reloc_local(object
, r_type
);
2088 // Report an unsupported relocation against a global symbol.
2091 Target_i386::Scan::unsupported_reloc_global(
2092 Sized_relobj_file
<32, false>* object
,
2093 unsigned int r_type
,
2096 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
2097 object
->name().c_str(), r_type
, gsym
->demangled_name().c_str());
2101 Target_i386::Scan::possible_function_pointer_reloc(unsigned int r_type
)
2105 case elfcpp::R_386_32
:
2106 case elfcpp::R_386_16
:
2107 case elfcpp::R_386_8
:
2108 case elfcpp::R_386_GOTOFF
:
2109 case elfcpp::R_386_GOT32
:
2110 case elfcpp::R_386_GOT32X
:
2121 Target_i386::Scan::local_reloc_may_be_function_pointer(
2125 Sized_relobj_file
<32, false>* ,
2128 const elfcpp::Rel
<32, false>& ,
2129 unsigned int r_type
,
2130 const elfcpp::Sym
<32, false>&)
2132 return possible_function_pointer_reloc(r_type
);
2136 Target_i386::Scan::global_reloc_may_be_function_pointer(
2140 Sized_relobj_file
<32, false>* ,
2143 const elfcpp::Rel
<32, false>& ,
2144 unsigned int r_type
,
2147 return possible_function_pointer_reloc(r_type
);
2150 // Scan a relocation for a global symbol.
2153 Target_i386::Scan::global(Symbol_table
* symtab
,
2155 Target_i386
* target
,
2156 Sized_relobj_file
<32, false>* object
,
2157 unsigned int data_shndx
,
2158 Output_section
* output_section
,
2159 const elfcpp::Rel
<32, false>& reloc
,
2160 unsigned int r_type
,
2163 // A STT_GNU_IFUNC symbol may require a PLT entry.
2164 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
2165 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
2166 target
->make_plt_entry(symtab
, layout
, gsym
);
2170 case elfcpp::R_386_NONE
:
2171 case elfcpp::R_386_GNU_VTINHERIT
:
2172 case elfcpp::R_386_GNU_VTENTRY
:
2175 case elfcpp::R_386_32
:
2176 case elfcpp::R_386_16
:
2177 case elfcpp::R_386_8
:
2179 // Make a PLT entry if necessary.
2180 if (gsym
->needs_plt_entry())
2182 target
->make_plt_entry(symtab
, layout
, gsym
);
2183 // Since this is not a PC-relative relocation, we may be
2184 // taking the address of a function. In that case we need to
2185 // set the entry in the dynamic symbol table to the address of
2187 if (gsym
->is_from_dynobj() && !parameters
->options().shared())
2188 gsym
->set_needs_dynsym_value();
2190 // Make a dynamic relocation if necessary.
2191 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
2193 if (!parameters
->options().output_is_position_independent()
2194 && gsym
->may_need_copy_reloc())
2196 target
->copy_reloc(symtab
, layout
, object
,
2197 data_shndx
, output_section
, gsym
, reloc
);
2199 else if (r_type
== elfcpp::R_386_32
2200 && gsym
->type() == elfcpp::STT_GNU_IFUNC
2201 && gsym
->can_use_relative_reloc(false)
2202 && !gsym
->is_from_dynobj()
2203 && !gsym
->is_undefined()
2204 && !gsym
->is_preemptible())
2206 // Use an IRELATIVE reloc for a locally defined
2207 // STT_GNU_IFUNC symbol. This makes a function
2208 // address in a PIE executable match the address in a
2209 // shared library that it links against.
2210 Reloc_section
* rel_dyn
= target
->rel_irelative_section(layout
);
2211 rel_dyn
->add_symbolless_global_addend(gsym
,
2212 elfcpp::R_386_IRELATIVE
,
2215 reloc
.get_r_offset());
2217 else if (r_type
== elfcpp::R_386_32
2218 && gsym
->can_use_relative_reloc(false))
2220 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2221 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
2222 output_section
, object
,
2223 data_shndx
, reloc
.get_r_offset());
2227 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2228 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
2229 data_shndx
, reloc
.get_r_offset());
2235 case elfcpp::R_386_PC32
:
2236 case elfcpp::R_386_PC16
:
2237 case elfcpp::R_386_PC8
:
2239 // Make a PLT entry if necessary.
2240 if (gsym
->needs_plt_entry())
2242 // These relocations are used for function calls only in
2243 // non-PIC code. For a 32-bit relocation in a shared library,
2244 // we'll need a text relocation anyway, so we can skip the
2245 // PLT entry and let the dynamic linker bind the call directly
2246 // to the target. For smaller relocations, we should use a
2247 // PLT entry to ensure that the call can reach.
2248 if (!parameters
->options().shared()
2249 || r_type
!= elfcpp::R_386_PC32
)
2250 target
->make_plt_entry(symtab
, layout
, gsym
);
2252 // Make a dynamic relocation if necessary.
2253 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
2255 if (parameters
->options().output_is_executable()
2256 && gsym
->may_need_copy_reloc())
2258 target
->copy_reloc(symtab
, layout
, object
,
2259 data_shndx
, output_section
, gsym
, reloc
);
2263 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2264 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
2265 data_shndx
, reloc
.get_r_offset());
2271 case elfcpp::R_386_GOT32
:
2272 case elfcpp::R_386_GOT32X
:
2274 // The symbol requires a GOT section.
2275 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
2277 // If we convert this from
2278 // mov foo@GOT(%reg), %reg
2280 // lea foo@GOTOFF(%reg), %reg
2281 // in Relocate::relocate, then there is nothing to do here.
2282 if (reloc
.get_r_offset() >= 2
2283 && Target_i386::can_convert_mov_to_lea(gsym
))
2285 section_size_type stype
;
2286 const unsigned char* view
= object
->section_contents(data_shndx
,
2288 if (view
[reloc
.get_r_offset() - 2] == 0x8b)
2292 if (gsym
->final_value_is_known())
2294 // For a STT_GNU_IFUNC symbol we want the PLT address.
2295 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
)
2296 got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
2298 got
->add_global(gsym
, GOT_TYPE_STANDARD
);
2302 // If this symbol is not fully resolved, we need to add a
2303 // GOT entry with a dynamic relocation.
2304 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2306 // Use a GLOB_DAT rather than a RELATIVE reloc if:
2308 // 1) The symbol may be defined in some other module.
2310 // 2) We are building a shared library and this is a
2311 // protected symbol; using GLOB_DAT means that the dynamic
2312 // linker can use the address of the PLT in the main
2313 // executable when appropriate so that function address
2314 // comparisons work.
2316 // 3) This is a STT_GNU_IFUNC symbol in position dependent
2317 // code, again so that function address comparisons work.
2318 if (gsym
->is_from_dynobj()
2319 || gsym
->is_undefined()
2320 || gsym
->is_preemptible()
2321 || (gsym
->visibility() == elfcpp::STV_PROTECTED
2322 && parameters
->options().shared())
2323 || (gsym
->type() == elfcpp::STT_GNU_IFUNC
2324 && parameters
->options().output_is_position_independent()))
2325 got
->add_global_with_rel(gsym
, GOT_TYPE_STANDARD
,
2326 rel_dyn
, elfcpp::R_386_GLOB_DAT
);
2329 // For a STT_GNU_IFUNC symbol we want to write the PLT
2330 // offset into the GOT, so that function pointer
2331 // comparisons work correctly.
2333 if (gsym
->type() != elfcpp::STT_GNU_IFUNC
)
2334 is_new
= got
->add_global(gsym
, GOT_TYPE_STANDARD
);
2337 is_new
= got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
2338 // Tell the dynamic linker to use the PLT address
2339 // when resolving relocations.
2340 if (gsym
->is_from_dynobj()
2341 && !parameters
->options().shared())
2342 gsym
->set_needs_dynsym_value();
2346 unsigned int got_off
= gsym
->got_offset(GOT_TYPE_STANDARD
);
2347 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
2355 case elfcpp::R_386_PLT32
:
2356 // If the symbol is fully resolved, this is just a PC32 reloc.
2357 // Otherwise we need a PLT entry.
2358 if (gsym
->final_value_is_known())
2360 // If building a shared library, we can also skip the PLT entry
2361 // if the symbol is defined in the output file and is protected
2363 if (gsym
->is_defined()
2364 && !gsym
->is_from_dynobj()
2365 && !gsym
->is_preemptible())
2367 target
->make_plt_entry(symtab
, layout
, gsym
);
2370 case elfcpp::R_386_GOTOFF
:
2371 case elfcpp::R_386_GOTPC
:
2372 // We need a GOT section.
2373 target
->got_section(symtab
, layout
);
2376 // These are relocations which should only be seen by the
2377 // dynamic linker, and should never be seen here.
2378 case elfcpp::R_386_COPY
:
2379 case elfcpp::R_386_GLOB_DAT
:
2380 case elfcpp::R_386_JUMP_SLOT
:
2381 case elfcpp::R_386_RELATIVE
:
2382 case elfcpp::R_386_IRELATIVE
:
2383 case elfcpp::R_386_TLS_TPOFF
:
2384 case elfcpp::R_386_TLS_DTPMOD32
:
2385 case elfcpp::R_386_TLS_DTPOFF32
:
2386 case elfcpp::R_386_TLS_TPOFF32
:
2387 case elfcpp::R_386_TLS_DESC
:
2388 gold_error(_("%s: unexpected reloc %u in object file"),
2389 object
->name().c_str(), r_type
);
2392 // These are initial tls relocs, which are expected when
2394 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2395 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2396 case elfcpp::R_386_TLS_DESC_CALL
:
2397 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2398 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2399 case elfcpp::R_386_TLS_IE
: // Initial-exec
2400 case elfcpp::R_386_TLS_IE_32
:
2401 case elfcpp::R_386_TLS_GOTIE
:
2402 case elfcpp::R_386_TLS_LE
: // Local-exec
2403 case elfcpp::R_386_TLS_LE_32
:
2405 const bool is_final
= gsym
->final_value_is_known();
2406 const tls::Tls_optimization optimized_type
2407 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
2410 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2411 if (optimized_type
== tls::TLSOPT_NONE
)
2413 // Create a pair of GOT entries for the module index and
2414 // dtv-relative offset.
2415 Output_data_got
<32, false>* got
2416 = target
->got_section(symtab
, layout
);
2417 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_PAIR
,
2418 target
->rel_dyn_section(layout
),
2419 elfcpp::R_386_TLS_DTPMOD32
,
2420 elfcpp::R_386_TLS_DTPOFF32
);
2422 else if (optimized_type
== tls::TLSOPT_TO_IE
)
2424 // Create a GOT entry for the tp-relative offset.
2425 Output_data_got
<32, false>* got
2426 = target
->got_section(symtab
, layout
);
2427 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
2428 target
->rel_dyn_section(layout
),
2429 elfcpp::R_386_TLS_TPOFF
);
2431 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2432 unsupported_reloc_global(object
, r_type
, gsym
);
2435 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (~oliva url)
2436 target
->define_tls_base_symbol(symtab
, layout
);
2437 if (optimized_type
== tls::TLSOPT_NONE
)
2439 // Create a double GOT entry with an R_386_TLS_DESC
2440 // reloc. The R_386_TLS_DESC reloc is resolved
2441 // lazily, so the GOT entry needs to be in an area in
2442 // .got.plt, not .got. Call got_section to make sure
2443 // the section has been created.
2444 target
->got_section(symtab
, layout
);
2445 Output_data_got
<32, false>* got
= target
->got_tlsdesc_section();
2446 Reloc_section
* rt
= target
->rel_tls_desc_section(layout
);
2447 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_DESC
, rt
,
2448 elfcpp::R_386_TLS_DESC
, 0);
2450 else if (optimized_type
== tls::TLSOPT_TO_IE
)
2452 // Create a GOT entry for the tp-relative offset.
2453 Output_data_got
<32, false>* got
2454 = target
->got_section(symtab
, layout
);
2455 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
2456 target
->rel_dyn_section(layout
),
2457 elfcpp::R_386_TLS_TPOFF
);
2459 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2460 unsupported_reloc_global(object
, r_type
, gsym
);
2463 case elfcpp::R_386_TLS_DESC_CALL
:
2466 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2467 if (optimized_type
== tls::TLSOPT_NONE
)
2469 // Create a GOT entry for the module index.
2470 target
->got_mod_index_entry(symtab
, layout
, object
);
2472 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2473 unsupported_reloc_global(object
, r_type
, gsym
);
2476 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2479 case elfcpp::R_386_TLS_IE
: // Initial-exec
2480 case elfcpp::R_386_TLS_IE_32
:
2481 case elfcpp::R_386_TLS_GOTIE
:
2482 layout
->set_has_static_tls();
2483 if (optimized_type
== tls::TLSOPT_NONE
)
2485 // For the R_386_TLS_IE relocation, we need to create a
2486 // dynamic relocation when building a shared library.
2487 if (r_type
== elfcpp::R_386_TLS_IE
2488 && parameters
->options().shared())
2490 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2491 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
2492 output_section
, object
,
2494 reloc
.get_r_offset());
2496 // Create a GOT entry for the tp-relative offset.
2497 Output_data_got
<32, false>* got
2498 = target
->got_section(symtab
, layout
);
2499 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2500 ? elfcpp::R_386_TLS_TPOFF32
2501 : elfcpp::R_386_TLS_TPOFF
);
2502 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2503 ? GOT_TYPE_TLS_OFFSET
2504 : GOT_TYPE_TLS_NOFFSET
);
2505 got
->add_global_with_rel(gsym
, got_type
,
2506 target
->rel_dyn_section(layout
),
2509 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2510 unsupported_reloc_global(object
, r_type
, gsym
);
2513 case elfcpp::R_386_TLS_LE
: // Local-exec
2514 case elfcpp::R_386_TLS_LE_32
:
2515 layout
->set_has_static_tls();
2516 if (parameters
->options().shared())
2518 // We need to create a dynamic relocation.
2519 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
2520 ? elfcpp::R_386_TLS_TPOFF32
2521 : elfcpp::R_386_TLS_TPOFF
);
2522 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2523 rel_dyn
->add_global(gsym
, dyn_r_type
, output_section
, object
,
2524 data_shndx
, reloc
.get_r_offset());
2534 case elfcpp::R_386_32PLT
:
2535 case elfcpp::R_386_TLS_GD_32
:
2536 case elfcpp::R_386_TLS_GD_PUSH
:
2537 case elfcpp::R_386_TLS_GD_CALL
:
2538 case elfcpp::R_386_TLS_GD_POP
:
2539 case elfcpp::R_386_TLS_LDM_32
:
2540 case elfcpp::R_386_TLS_LDM_PUSH
:
2541 case elfcpp::R_386_TLS_LDM_CALL
:
2542 case elfcpp::R_386_TLS_LDM_POP
:
2543 case elfcpp::R_386_USED_BY_INTEL_200
:
2545 unsupported_reloc_global(object
, r_type
, gsym
);
2550 // Process relocations for gc.
2553 Target_i386::gc_process_relocs(Symbol_table
* symtab
,
2555 Sized_relobj_file
<32, false>* object
,
2556 unsigned int data_shndx
,
2558 const unsigned char* prelocs
,
2560 Output_section
* output_section
,
2561 bool needs_special_offset_handling
,
2562 size_t local_symbol_count
,
2563 const unsigned char* plocal_symbols
)
2565 gold::gc_process_relocs
<32, false, Target_i386
, elfcpp::SHT_REL
,
2567 Target_i386::Relocatable_size_for_reloc
>(
2576 needs_special_offset_handling
,
2581 // Scan relocations for a section.
2584 Target_i386::scan_relocs(Symbol_table
* symtab
,
2586 Sized_relobj_file
<32, false>* object
,
2587 unsigned int data_shndx
,
2588 unsigned int sh_type
,
2589 const unsigned char* prelocs
,
2591 Output_section
* output_section
,
2592 bool needs_special_offset_handling
,
2593 size_t local_symbol_count
,
2594 const unsigned char* plocal_symbols
)
2596 if (sh_type
== elfcpp::SHT_RELA
)
2598 gold_error(_("%s: unsupported RELA reloc section"),
2599 object
->name().c_str());
2603 gold::scan_relocs
<32, false, Target_i386
, elfcpp::SHT_REL
,
2613 needs_special_offset_handling
,
2618 // Finalize the sections.
2621 Target_i386::do_finalize_sections(
2623 const Input_objects
*,
2624 Symbol_table
* symtab
)
2626 const Reloc_section
* rel_plt
= (this->plt_
== NULL
2628 : this->plt_
->rel_plt());
2629 layout
->add_target_dynamic_tags(true, this->got_plt_
, rel_plt
,
2630 this->rel_dyn_
, true, false);
2632 // Emit any relocs we saved in an attempt to avoid generating COPY
2634 if (this->copy_relocs_
.any_saved_relocs())
2635 this->copy_relocs_
.emit(this->rel_dyn_section(layout
));
2637 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
2638 // the .got.plt section.
2639 Symbol
* sym
= this->global_offset_table_
;
2642 uint32_t data_size
= this->got_plt_
->current_data_size();
2643 symtab
->get_sized_symbol
<32>(sym
)->set_symsize(data_size
);
2646 if (parameters
->doing_static_link()
2647 && (this->plt_
== NULL
|| !this->plt_
->has_irelative_section()))
2649 // If linking statically, make sure that the __rel_iplt symbols
2650 // were defined if necessary, even if we didn't create a PLT.
2651 static const Define_symbol_in_segment syms
[] =
2654 "__rel_iplt_start", // name
2655 elfcpp::PT_LOAD
, // segment_type
2656 elfcpp::PF_W
, // segment_flags_set
2657 elfcpp::PF(0), // segment_flags_clear
2660 elfcpp::STT_NOTYPE
, // type
2661 elfcpp::STB_GLOBAL
, // binding
2662 elfcpp::STV_HIDDEN
, // visibility
2664 Symbol::SEGMENT_START
, // offset_from_base
2668 "__rel_iplt_end", // name
2669 elfcpp::PT_LOAD
, // segment_type
2670 elfcpp::PF_W
, // segment_flags_set
2671 elfcpp::PF(0), // segment_flags_clear
2674 elfcpp::STT_NOTYPE
, // type
2675 elfcpp::STB_GLOBAL
, // binding
2676 elfcpp::STV_HIDDEN
, // visibility
2678 Symbol::SEGMENT_START
, // offset_from_base
2683 symtab
->define_symbols(layout
, 2, syms
,
2684 layout
->script_options()->saw_sections_clause());
2688 // Return whether a direct absolute static relocation needs to be applied.
2689 // In cases where Scan::local() or Scan::global() has created
2690 // a dynamic relocation other than R_386_RELATIVE, the addend
2691 // of the relocation is carried in the data, and we must not
2692 // apply the static relocation.
2695 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
2696 unsigned int r_type
,
2698 Output_section
* output_section
)
2700 // If the output section is not allocated, then we didn't call
2701 // scan_relocs, we didn't create a dynamic reloc, and we must apply
2703 if ((output_section
->flags() & elfcpp::SHF_ALLOC
) == 0)
2706 int ref_flags
= Scan::get_reference_flags(r_type
);
2708 // For local symbols, we will have created a non-RELATIVE dynamic
2709 // relocation only if (a) the output is position independent,
2710 // (b) the relocation is absolute (not pc- or segment-relative), and
2711 // (c) the relocation is not 32 bits wide.
2713 return !(parameters
->options().output_is_position_independent()
2714 && (ref_flags
& Symbol::ABSOLUTE_REF
)
2717 // For global symbols, we use the same helper routines used in the
2718 // scan pass. If we did not create a dynamic relocation, or if we
2719 // created a RELATIVE dynamic relocation, we should apply the static
2721 bool has_dyn
= gsym
->needs_dynamic_reloc(ref_flags
);
2722 bool is_rel
= (ref_flags
& Symbol::ABSOLUTE_REF
)
2723 && gsym
->can_use_relative_reloc(ref_flags
2724 & Symbol::FUNCTION_CALL
);
2725 return !has_dyn
|| is_rel
;
2728 // Perform a relocation.
2731 Target_i386::Relocate::relocate(const Relocate_info
<32, false>* relinfo
,
2732 Target_i386
* target
,
2733 Output_section
* output_section
,
2735 const elfcpp::Rel
<32, false>& rel
,
2736 unsigned int r_type
,
2737 const Sized_symbol
<32>* gsym
,
2738 const Symbol_value
<32>* psymval
,
2739 unsigned char* view
,
2740 elfcpp::Elf_types
<32>::Elf_Addr address
,
2741 section_size_type view_size
)
2743 if (this->skip_call_tls_get_addr_
)
2745 if ((r_type
!= elfcpp::R_386_PLT32
2746 && r_type
!= elfcpp::R_386_PC32
)
2748 || strcmp(gsym
->name(), "___tls_get_addr") != 0)
2749 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2750 _("missing expected TLS relocation"));
2753 this->skip_call_tls_get_addr_
= false;
2761 const Sized_relobj_file
<32, false>* object
= relinfo
->object
;
2763 // Pick the value to use for symbols defined in shared objects.
2764 Symbol_value
<32> symval
;
2766 && gsym
->type() == elfcpp::STT_GNU_IFUNC
2767 && r_type
== elfcpp::R_386_32
2768 && gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
))
2769 && gsym
->can_use_relative_reloc(false)
2770 && !gsym
->is_from_dynobj()
2771 && !gsym
->is_undefined()
2772 && !gsym
->is_preemptible())
2774 // In this case we are generating a R_386_IRELATIVE reloc. We
2775 // want to use the real value of the symbol, not the PLT offset.
2777 else if (gsym
!= NULL
2778 && gsym
->use_plt_offset(Scan::get_reference_flags(r_type
)))
2780 symval
.set_output_value(target
->plt_address_for_global(gsym
));
2783 else if (gsym
== NULL
&& psymval
->is_ifunc_symbol())
2785 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2786 if (object
->local_has_plt_offset(r_sym
))
2788 symval
.set_output_value(target
->plt_address_for_local(object
, r_sym
));
2797 case elfcpp::R_386_NONE
:
2798 case elfcpp::R_386_GNU_VTINHERIT
:
2799 case elfcpp::R_386_GNU_VTENTRY
:
2802 case elfcpp::R_386_32
:
2803 if (should_apply_static_reloc(gsym
, r_type
, true, output_section
))
2804 Relocate_functions
<32, false>::rel32(view
, object
, psymval
);
2807 case elfcpp::R_386_PC32
:
2808 if (should_apply_static_reloc(gsym
, r_type
, true, output_section
))
2809 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
2812 case elfcpp::R_386_16
:
2813 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2814 Relocate_functions
<32, false>::rel16(view
, object
, psymval
);
2817 case elfcpp::R_386_PC16
:
2818 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2819 Relocate_functions
<32, false>::pcrel16(view
, object
, psymval
, address
);
2822 case elfcpp::R_386_8
:
2823 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2824 Relocate_functions
<32, false>::rel8(view
, object
, psymval
);
2827 case elfcpp::R_386_PC8
:
2828 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2829 Relocate_functions
<32, false>::pcrel8(view
, object
, psymval
, address
);
2832 case elfcpp::R_386_PLT32
:
2833 gold_assert(gsym
== NULL
2834 || gsym
->has_plt_offset()
2835 || gsym
->final_value_is_known()
2836 || (gsym
->is_defined()
2837 && !gsym
->is_from_dynobj()
2838 && !gsym
->is_preemptible()));
2839 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
2842 case elfcpp::R_386_GOT32
:
2843 case elfcpp::R_386_GOT32X
:
2844 baseless
= (view
[-1] & 0xc7) == 0x5;
2845 // R_386_GOT32 and R_386_GOT32X don't work without base register
2846 // when generating a position-independent output file.
2848 && parameters
->options().output_is_position_independent())
2851 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2852 _("unexpected reloc %u against global symbol %s without base register in object file when generating a position-independent output file"),
2853 r_type
, gsym
->demangled_name().c_str());
2855 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2856 _("unexpected reloc %u against local symbol without base register in object file when generating a position-independent output file"),
2861 // mov foo@GOT(%reg), %reg
2863 // lea foo@GOTOFF(%reg), %reg
2865 if (rel
.get_r_offset() >= 2
2867 && ((gsym
== NULL
&& !psymval
->is_ifunc_symbol())
2869 && Target_i386::can_convert_mov_to_lea(gsym
))))
2872 elfcpp::Elf_types
<32>::Elf_Addr value
;
2873 value
= psymval
->value(object
, 0);
2874 // Don't subtract the .got.plt section address for baseless
2877 value
-= target
->got_plt_section()->address();
2878 Relocate_functions
<32, false>::rel32(view
, value
);
2882 // The GOT pointer points to the end of the GOT section.
2883 // We need to subtract the size of the GOT section to get
2884 // the actual offset to use in the relocation.
2885 unsigned int got_offset
= 0;
2888 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
2889 got_offset
= (gsym
->got_offset(GOT_TYPE_STANDARD
)
2890 - target
->got_size());
2894 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2895 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
2896 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
2897 - target
->got_size());
2899 // Add the .got.plt section address for baseless addressing.
2901 got_offset
+= target
->got_plt_section()->address();
2902 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2906 case elfcpp::R_386_GOTOFF
:
2908 elfcpp::Elf_types
<32>::Elf_Addr value
;
2909 value
= (psymval
->value(object
, 0)
2910 - target
->got_plt_section()->address());
2911 Relocate_functions
<32, false>::rel32(view
, value
);
2915 case elfcpp::R_386_GOTPC
:
2917 elfcpp::Elf_types
<32>::Elf_Addr value
;
2918 value
= target
->got_plt_section()->address();
2919 Relocate_functions
<32, false>::pcrel32(view
, value
, address
);
2923 case elfcpp::R_386_COPY
:
2924 case elfcpp::R_386_GLOB_DAT
:
2925 case elfcpp::R_386_JUMP_SLOT
:
2926 case elfcpp::R_386_RELATIVE
:
2927 case elfcpp::R_386_IRELATIVE
:
2928 // These are outstanding tls relocs, which are unexpected when
2930 case elfcpp::R_386_TLS_TPOFF
:
2931 case elfcpp::R_386_TLS_DTPMOD32
:
2932 case elfcpp::R_386_TLS_DTPOFF32
:
2933 case elfcpp::R_386_TLS_TPOFF32
:
2934 case elfcpp::R_386_TLS_DESC
:
2935 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2936 _("unexpected reloc %u in object file"),
2940 // These are initial tls relocs, which are expected when
2942 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2943 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2944 case elfcpp::R_386_TLS_DESC_CALL
:
2945 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2946 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2947 case elfcpp::R_386_TLS_IE
: // Initial-exec
2948 case elfcpp::R_386_TLS_IE_32
:
2949 case elfcpp::R_386_TLS_GOTIE
:
2950 case elfcpp::R_386_TLS_LE
: // Local-exec
2951 case elfcpp::R_386_TLS_LE_32
:
2952 this->relocate_tls(relinfo
, target
, relnum
, rel
, r_type
, gsym
, psymval
,
2953 view
, address
, view_size
);
2956 case elfcpp::R_386_32PLT
:
2957 case elfcpp::R_386_TLS_GD_32
:
2958 case elfcpp::R_386_TLS_GD_PUSH
:
2959 case elfcpp::R_386_TLS_GD_CALL
:
2960 case elfcpp::R_386_TLS_GD_POP
:
2961 case elfcpp::R_386_TLS_LDM_32
:
2962 case elfcpp::R_386_TLS_LDM_PUSH
:
2963 case elfcpp::R_386_TLS_LDM_CALL
:
2964 case elfcpp::R_386_TLS_LDM_POP
:
2965 case elfcpp::R_386_USED_BY_INTEL_200
:
2967 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2968 _("unsupported reloc %u"),
2976 // Perform a TLS relocation.
2979 Target_i386::Relocate::relocate_tls(const Relocate_info
<32, false>* relinfo
,
2980 Target_i386
* target
,
2982 const elfcpp::Rel
<32, false>& rel
,
2983 unsigned int r_type
,
2984 const Sized_symbol
<32>* gsym
,
2985 const Symbol_value
<32>* psymval
,
2986 unsigned char* view
,
2987 elfcpp::Elf_types
<32>::Elf_Addr
,
2988 section_size_type view_size
)
2990 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
2992 const Sized_relobj_file
<32, false>* object
= relinfo
->object
;
2994 elfcpp::Elf_types
<32>::Elf_Addr value
= psymval
->value(object
, 0);
2996 const bool is_final
= (gsym
== NULL
2997 ? !parameters
->options().shared()
2998 : gsym
->final_value_is_known());
2999 const tls::Tls_optimization optimized_type
3000 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
3003 case elfcpp::R_386_TLS_GD
: // Global-dynamic
3004 if (optimized_type
== tls::TLSOPT_TO_LE
)
3006 if (tls_segment
== NULL
)
3008 gold_assert(parameters
->errors()->error_count() > 0
3009 || issue_undefined_symbol_error(gsym
));
3012 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
3013 rel
, r_type
, value
, view
,
3019 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
3020 ? GOT_TYPE_TLS_NOFFSET
3021 : GOT_TYPE_TLS_PAIR
);
3022 unsigned int got_offset
;
3025 gold_assert(gsym
->has_got_offset(got_type
));
3026 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
3030 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
3031 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
3032 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
3033 - target
->got_size());
3035 if (optimized_type
== tls::TLSOPT_TO_IE
)
3037 this->tls_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
3038 got_offset
, view
, view_size
);
3041 else if (optimized_type
== tls::TLSOPT_NONE
)
3043 // Relocate the field with the offset of the pair of GOT
3045 Relocate_functions
<32, false>::rel32(view
, got_offset
);
3049 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3050 _("unsupported reloc %u"),
3054 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
3055 case elfcpp::R_386_TLS_DESC_CALL
:
3056 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
3057 if (optimized_type
== tls::TLSOPT_TO_LE
)
3059 if (tls_segment
== NULL
)
3061 gold_assert(parameters
->errors()->error_count() > 0
3062 || issue_undefined_symbol_error(gsym
));
3065 this->tls_desc_gd_to_le(relinfo
, relnum
, tls_segment
,
3066 rel
, r_type
, value
, view
,
3072 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
3073 ? GOT_TYPE_TLS_NOFFSET
3074 : GOT_TYPE_TLS_DESC
);
3075 unsigned int got_offset
= 0;
3076 if (r_type
== elfcpp::R_386_TLS_GOTDESC
3077 && optimized_type
== tls::TLSOPT_NONE
)
3079 // We created GOT entries in the .got.tlsdesc portion of
3080 // the .got.plt section, but the offset stored in the
3081 // symbol is the offset within .got.tlsdesc.
3082 got_offset
= (target
->got_size()
3083 + target
->got_plt_section()->data_size());
3087 gold_assert(gsym
->has_got_offset(got_type
));
3088 got_offset
+= gsym
->got_offset(got_type
) - target
->got_size();
3092 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
3093 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
3094 got_offset
+= (object
->local_got_offset(r_sym
, got_type
)
3095 - target
->got_size());
3097 if (optimized_type
== tls::TLSOPT_TO_IE
)
3099 if (tls_segment
== NULL
)
3101 gold_assert(parameters
->errors()->error_count() > 0
3102 || issue_undefined_symbol_error(gsym
));
3105 this->tls_desc_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
3106 got_offset
, view
, view_size
);
3109 else if (optimized_type
== tls::TLSOPT_NONE
)
3111 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
3113 // Relocate the field with the offset of the pair of GOT
3115 Relocate_functions
<32, false>::rel32(view
, got_offset
);
3120 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3121 _("unsupported reloc %u"),
3125 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
3126 if (this->local_dynamic_type_
== LOCAL_DYNAMIC_SUN
)
3128 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3129 _("both SUN and GNU model "
3130 "TLS relocations"));
3133 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
3134 if (optimized_type
== tls::TLSOPT_TO_LE
)
3136 if (tls_segment
== NULL
)
3138 gold_assert(parameters
->errors()->error_count() > 0
3139 || issue_undefined_symbol_error(gsym
));
3142 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rel
, r_type
,
3143 value
, view
, view_size
);
3146 else if (optimized_type
== tls::TLSOPT_NONE
)
3148 // Relocate the field with the offset of the GOT entry for
3149 // the module index.
3150 unsigned int got_offset
;
3151 got_offset
= (target
->got_mod_index_entry(NULL
, NULL
, NULL
)
3152 - target
->got_size());
3153 Relocate_functions
<32, false>::rel32(view
, got_offset
);
3156 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3157 _("unsupported reloc %u"),
3161 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
3162 if (optimized_type
== tls::TLSOPT_TO_LE
)
3164 // This reloc can appear in debugging sections, in which
3165 // case we must not convert to local-exec. We decide what
3166 // to do based on whether the section is marked as
3167 // containing executable code. That is what the GNU linker
3169 elfcpp::Shdr
<32, false> shdr(relinfo
->data_shdr
);
3170 if ((shdr
.get_sh_flags() & elfcpp::SHF_EXECINSTR
) != 0)
3172 if (tls_segment
== NULL
)
3174 gold_assert(parameters
->errors()->error_count() > 0
3175 || issue_undefined_symbol_error(gsym
));
3178 value
-= tls_segment
->memsz();
3181 Relocate_functions
<32, false>::rel32(view
, value
);
3184 case elfcpp::R_386_TLS_IE
: // Initial-exec
3185 case elfcpp::R_386_TLS_GOTIE
:
3186 case elfcpp::R_386_TLS_IE_32
:
3187 if (optimized_type
== tls::TLSOPT_TO_LE
)
3189 if (tls_segment
== NULL
)
3191 gold_assert(parameters
->errors()->error_count() > 0
3192 || issue_undefined_symbol_error(gsym
));
3195 Target_i386::Relocate::tls_ie_to_le(relinfo
, relnum
, tls_segment
,
3196 rel
, r_type
, value
, view
,
3200 else if (optimized_type
== tls::TLSOPT_NONE
)
3202 // Relocate the field with the offset of the GOT entry for
3203 // the tp-relative offset of the symbol.
3204 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
3205 ? GOT_TYPE_TLS_OFFSET
3206 : GOT_TYPE_TLS_NOFFSET
);
3207 unsigned int got_offset
;
3210 gold_assert(gsym
->has_got_offset(got_type
));
3211 got_offset
= gsym
->got_offset(got_type
);
3215 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
3216 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
3217 got_offset
= object
->local_got_offset(r_sym
, got_type
);
3219 // For the R_386_TLS_IE relocation, we need to apply the
3220 // absolute address of the GOT entry.
3221 if (r_type
== elfcpp::R_386_TLS_IE
)
3222 got_offset
+= target
->got_plt_section()->address();
3223 // All GOT offsets are relative to the end of the GOT.
3224 got_offset
-= target
->got_size();
3225 Relocate_functions
<32, false>::rel32(view
, got_offset
);
3228 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3229 _("unsupported reloc %u"),
3233 case elfcpp::R_386_TLS_LE
: // Local-exec
3234 // If we're creating a shared library, a dynamic relocation will
3235 // have been created for this location, so do not apply it now.
3236 if (!parameters
->options().shared())
3238 if (tls_segment
== NULL
)
3240 gold_assert(parameters
->errors()->error_count() > 0
3241 || issue_undefined_symbol_error(gsym
));
3244 value
-= tls_segment
->memsz();
3245 Relocate_functions
<32, false>::rel32(view
, value
);
3249 case elfcpp::R_386_TLS_LE_32
:
3250 // If we're creating a shared library, a dynamic relocation will
3251 // have been created for this location, so do not apply it now.
3252 if (!parameters
->options().shared())
3254 if (tls_segment
== NULL
)
3256 gold_assert(parameters
->errors()->error_count() > 0
3257 || issue_undefined_symbol_error(gsym
));
3260 value
= tls_segment
->memsz() - value
;
3261 Relocate_functions
<32, false>::rel32(view
, value
);
3267 // Do a relocation in which we convert a TLS General-Dynamic to a
3271 Target_i386::Relocate::tls_gd_to_le(const Relocate_info
<32, false>* relinfo
,
3273 Output_segment
* tls_segment
,
3274 const elfcpp::Rel
<32, false>& rel
,
3276 elfcpp::Elf_types
<32>::Elf_Addr value
,
3277 unsigned char* view
,
3278 section_size_type view_size
)
3280 // leal foo(,%reg,1),%eax; call ___tls_get_addr
3281 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
3282 // leal foo(%reg),%eax; call ___tls_get_addr
3283 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
3285 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3286 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
3288 unsigned char op1
= view
[-1];
3289 unsigned char op2
= view
[-2];
3291 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3292 op2
== 0x8d || op2
== 0x04);
3293 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
3299 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
3300 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
3301 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3302 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
3303 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3307 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3308 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
3309 if (rel
.get_r_offset() + 9 < view_size
3312 // There is a trailing nop. Use the size byte subl.
3313 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3318 // Use the five byte subl.
3319 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
3323 value
= tls_segment
->memsz() - value
;
3324 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
3326 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3328 this->skip_call_tls_get_addr_
= true;
3331 // Do a relocation in which we convert a TLS General-Dynamic to an
3335 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info
<32, false>* relinfo
,
3338 const elfcpp::Rel
<32, false>& rel
,
3340 elfcpp::Elf_types
<32>::Elf_Addr value
,
3341 unsigned char* view
,
3342 section_size_type view_size
)
3344 // leal foo(,%ebx,1),%eax; call ___tls_get_addr
3345 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
3346 // leal foo(%ebx),%eax; call ___tls_get_addr; nop
3347 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
3349 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3350 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
3352 unsigned char op1
= view
[-1];
3353 unsigned char op2
= view
[-2];
3355 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3356 op2
== 0x8d || op2
== 0x04);
3357 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
3363 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
3364 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
3365 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3366 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
3371 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 10);
3372 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3373 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
3374 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[9] == 0x90);
3378 memcpy(view
+ roff
- 8, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
3379 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
3381 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3383 this->skip_call_tls_get_addr_
= true;
3386 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3387 // General-Dynamic to a Local-Exec.
3390 Target_i386::Relocate::tls_desc_gd_to_le(
3391 const Relocate_info
<32, false>* relinfo
,
3393 Output_segment
* tls_segment
,
3394 const elfcpp::Rel
<32, false>& rel
,
3395 unsigned int r_type
,
3396 elfcpp::Elf_types
<32>::Elf_Addr value
,
3397 unsigned char* view
,
3398 section_size_type view_size
)
3400 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
3402 // leal foo@TLSDESC(%ebx), %eax
3403 // ==> leal foo@NTPOFF, %eax
3404 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3405 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3406 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3407 view
[-2] == 0x8d && view
[-1] == 0x83);
3409 value
-= tls_segment
->memsz();
3410 Relocate_functions
<32, false>::rel32(view
, value
);
3414 // call *foo@TLSCALL(%eax)
3416 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
3417 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
3418 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3419 view
[0] == 0xff && view
[1] == 0x10);
3425 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3426 // General-Dynamic to an Initial-Exec.
3429 Target_i386::Relocate::tls_desc_gd_to_ie(
3430 const Relocate_info
<32, false>* relinfo
,
3433 const elfcpp::Rel
<32, false>& rel
,
3434 unsigned int r_type
,
3435 elfcpp::Elf_types
<32>::Elf_Addr value
,
3436 unsigned char* view
,
3437 section_size_type view_size
)
3439 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
3441 // leal foo@TLSDESC(%ebx), %eax
3442 // ==> movl foo@GOTNTPOFF(%ebx), %eax
3443 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3444 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3445 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3446 view
[-2] == 0x8d && view
[-1] == 0x83);
3448 Relocate_functions
<32, false>::rel32(view
, value
);
3452 // call *foo@TLSCALL(%eax)
3454 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
3455 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
3456 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3457 view
[0] == 0xff && view
[1] == 0x10);
3463 // Do a relocation in which we convert a TLS Local-Dynamic to a
3467 Target_i386::Relocate::tls_ld_to_le(const Relocate_info
<32, false>* relinfo
,
3470 const elfcpp::Rel
<32, false>& rel
,
3472 elfcpp::Elf_types
<32>::Elf_Addr
,
3473 unsigned char* view
,
3474 section_size_type view_size
)
3476 // leal foo(%reg), %eax; call ___tls_get_addr
3477 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
3479 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3480 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
3482 // FIXME: Does this test really always pass?
3483 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3484 view
[-2] == 0x8d && view
[-1] == 0x83);
3486 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
3488 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
3490 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3492 this->skip_call_tls_get_addr_
= true;
3495 // Do a relocation in which we convert a TLS Initial-Exec to a
3499 Target_i386::Relocate::tls_ie_to_le(const Relocate_info
<32, false>* relinfo
,
3501 Output_segment
* tls_segment
,
3502 const elfcpp::Rel
<32, false>& rel
,
3503 unsigned int r_type
,
3504 elfcpp::Elf_types
<32>::Elf_Addr value
,
3505 unsigned char* view
,
3506 section_size_type view_size
)
3508 // We have to actually change the instructions, which means that we
3509 // need to examine the opcodes to figure out which instruction we
3511 if (r_type
== elfcpp::R_386_TLS_IE
)
3513 // movl %gs:XX,%eax ==> movl $YY,%eax
3514 // movl %gs:XX,%reg ==> movl $YY,%reg
3515 // addl %gs:XX,%reg ==> addl $YY,%reg
3516 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -1);
3517 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3519 unsigned char op1
= view
[-1];
3522 // movl XX,%eax ==> movl $YY,%eax
3527 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3529 unsigned char op2
= view
[-2];
3532 // movl XX,%reg ==> movl $YY,%reg
3533 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3534 (op1
& 0xc7) == 0x05);
3536 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3538 else if (op2
== 0x03)
3540 // addl XX,%reg ==> addl $YY,%reg
3541 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3542 (op1
& 0xc7) == 0x05);
3544 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3547 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
3552 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
3553 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
3554 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
3555 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3556 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3558 unsigned char op1
= view
[-1];
3559 unsigned char op2
= view
[-2];
3560 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3561 (op1
& 0xc0) == 0x80 && (op1
& 7) != 4);
3564 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
3566 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3568 else if (op2
== 0x2b)
3570 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
3572 view
[-1] = 0xe8 | ((op1
>> 3) & 7);
3574 else if (op2
== 0x03)
3576 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
3578 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3581 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
3584 value
= tls_segment
->memsz() - value
;
3585 if (r_type
== elfcpp::R_386_TLS_IE
|| r_type
== elfcpp::R_386_TLS_GOTIE
)
3588 Relocate_functions
<32, false>::rel32(view
, value
);
3591 // Relocate section data.
3594 Target_i386::relocate_section(const Relocate_info
<32, false>* relinfo
,
3595 unsigned int sh_type
,
3596 const unsigned char* prelocs
,
3598 Output_section
* output_section
,
3599 bool needs_special_offset_handling
,
3600 unsigned char* view
,
3601 elfcpp::Elf_types
<32>::Elf_Addr address
,
3602 section_size_type view_size
,
3603 const Reloc_symbol_changes
* reloc_symbol_changes
)
3605 gold_assert(sh_type
== elfcpp::SHT_REL
);
3607 gold::relocate_section
<32, false, Target_i386
, elfcpp::SHT_REL
,
3608 Target_i386::Relocate
, gold::Default_comdat_behavior
>(
3614 needs_special_offset_handling
,
3618 reloc_symbol_changes
);
3621 // Return the size of a relocation while scanning during a relocatable
3625 Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
3626 unsigned int r_type
,
3631 case elfcpp::R_386_NONE
:
3632 case elfcpp::R_386_GNU_VTINHERIT
:
3633 case elfcpp::R_386_GNU_VTENTRY
:
3634 case elfcpp::R_386_TLS_GD
: // Global-dynamic
3635 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
3636 case elfcpp::R_386_TLS_DESC_CALL
:
3637 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
3638 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
3639 case elfcpp::R_386_TLS_IE
: // Initial-exec
3640 case elfcpp::R_386_TLS_IE_32
:
3641 case elfcpp::R_386_TLS_GOTIE
:
3642 case elfcpp::R_386_TLS_LE
: // Local-exec
3643 case elfcpp::R_386_TLS_LE_32
:
3646 case elfcpp::R_386_32
:
3647 case elfcpp::R_386_PC32
:
3648 case elfcpp::R_386_GOT32
:
3649 case elfcpp::R_386_GOT32X
:
3650 case elfcpp::R_386_PLT32
:
3651 case elfcpp::R_386_GOTOFF
:
3652 case elfcpp::R_386_GOTPC
:
3655 case elfcpp::R_386_16
:
3656 case elfcpp::R_386_PC16
:
3659 case elfcpp::R_386_8
:
3660 case elfcpp::R_386_PC8
:
3663 // These are relocations which should only be seen by the
3664 // dynamic linker, and should never be seen here.
3665 case elfcpp::R_386_COPY
:
3666 case elfcpp::R_386_GLOB_DAT
:
3667 case elfcpp::R_386_JUMP_SLOT
:
3668 case elfcpp::R_386_RELATIVE
:
3669 case elfcpp::R_386_IRELATIVE
:
3670 case elfcpp::R_386_TLS_TPOFF
:
3671 case elfcpp::R_386_TLS_DTPMOD32
:
3672 case elfcpp::R_386_TLS_DTPOFF32
:
3673 case elfcpp::R_386_TLS_TPOFF32
:
3674 case elfcpp::R_386_TLS_DESC
:
3675 object
->error(_("unexpected reloc %u in object file"), r_type
);
3678 case elfcpp::R_386_32PLT
:
3679 case elfcpp::R_386_TLS_GD_32
:
3680 case elfcpp::R_386_TLS_GD_PUSH
:
3681 case elfcpp::R_386_TLS_GD_CALL
:
3682 case elfcpp::R_386_TLS_GD_POP
:
3683 case elfcpp::R_386_TLS_LDM_32
:
3684 case elfcpp::R_386_TLS_LDM_PUSH
:
3685 case elfcpp::R_386_TLS_LDM_CALL
:
3686 case elfcpp::R_386_TLS_LDM_POP
:
3687 case elfcpp::R_386_USED_BY_INTEL_200
:
3689 object
->error(_("unsupported reloc %u in object file"), r_type
);
3694 // Scan the relocs during a relocatable link.
3697 Target_i386::scan_relocatable_relocs(Symbol_table
* symtab
,
3699 Sized_relobj_file
<32, false>* object
,
3700 unsigned int data_shndx
,
3701 unsigned int sh_type
,
3702 const unsigned char* prelocs
,
3704 Output_section
* output_section
,
3705 bool needs_special_offset_handling
,
3706 size_t local_symbol_count
,
3707 const unsigned char* plocal_symbols
,
3708 Relocatable_relocs
* rr
)
3710 gold_assert(sh_type
== elfcpp::SHT_REL
);
3712 typedef gold::Default_scan_relocatable_relocs
<elfcpp::SHT_REL
,
3713 Relocatable_size_for_reloc
> Scan_relocatable_relocs
;
3715 gold::scan_relocatable_relocs
<32, false, elfcpp::SHT_REL
,
3716 Scan_relocatable_relocs
>(
3724 needs_special_offset_handling
,
3730 // Emit relocations for a section.
3733 Target_i386::relocate_relocs(
3734 const Relocate_info
<32, false>* relinfo
,
3735 unsigned int sh_type
,
3736 const unsigned char* prelocs
,
3738 Output_section
* output_section
,
3739 elfcpp::Elf_types
<32>::Elf_Off offset_in_output_section
,
3740 const Relocatable_relocs
* rr
,
3741 unsigned char* view
,
3742 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
3743 section_size_type view_size
,
3744 unsigned char* reloc_view
,
3745 section_size_type reloc_view_size
)
3747 gold_assert(sh_type
== elfcpp::SHT_REL
);
3749 gold::relocate_relocs
<32, false, elfcpp::SHT_REL
>(
3754 offset_in_output_section
,
3763 // Return the value to use for a dynamic which requires special
3764 // treatment. This is how we support equality comparisons of function
3765 // pointers across shared library boundaries, as described in the
3766 // processor specific ABI supplement.
3769 Target_i386::do_dynsym_value(const Symbol
* gsym
) const
3771 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
3772 return this->plt_address_for_global(gsym
);
3775 // Return a string used to fill a code section with nops to take up
3776 // the specified length.
3779 Target_i386::do_code_fill(section_size_type length
) const
3783 // Build a jmp instruction to skip over the bytes.
3784 unsigned char jmp
[5];
3786 elfcpp::Swap_unaligned
<32, false>::writeval(jmp
+ 1, length
- 5);
3787 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
3788 + std::string(length
- 5, static_cast<char>(0x90)));
3791 // Nop sequences of various lengths.
3792 const char nop1
[1] = { '\x90' }; // nop
3793 const char nop2
[2] = { '\x66', '\x90' }; // xchg %ax %ax
3794 const char nop3
[3] = { '\x8d', '\x76', '\x00' }; // leal 0(%esi),%esi
3795 const char nop4
[4] = { '\x8d', '\x74', '\x26', // leal 0(%esi,1),%esi
3797 const char nop5
[5] = { '\x90', '\x8d', '\x74', // nop
3798 '\x26', '\x00' }; // leal 0(%esi,1),%esi
3799 const char nop6
[6] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3800 '\x00', '\x00', '\x00' };
3801 const char nop7
[7] = { '\x8d', '\xb4', '\x26', // leal 0L(%esi,1),%esi
3802 '\x00', '\x00', '\x00',
3804 const char nop8
[8] = { '\x90', '\x8d', '\xb4', // nop
3805 '\x26', '\x00', '\x00', // leal 0L(%esi,1),%esi
3807 const char nop9
[9] = { '\x89', '\xf6', '\x8d', // movl %esi,%esi
3808 '\xbc', '\x27', '\x00', // leal 0L(%edi,1),%edi
3809 '\x00', '\x00', '\x00' };
3810 const char nop10
[10] = { '\x8d', '\x76', '\x00', // leal 0(%esi),%esi
3811 '\x8d', '\xbc', '\x27', // leal 0L(%edi,1),%edi
3812 '\x00', '\x00', '\x00',
3814 const char nop11
[11] = { '\x8d', '\x74', '\x26', // leal 0(%esi,1),%esi
3815 '\x00', '\x8d', '\xbc', // leal 0L(%edi,1),%edi
3816 '\x27', '\x00', '\x00',
3818 const char nop12
[12] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3819 '\x00', '\x00', '\x00', // leal 0L(%edi),%edi
3820 '\x8d', '\xbf', '\x00',
3821 '\x00', '\x00', '\x00' };
3822 const char nop13
[13] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3823 '\x00', '\x00', '\x00', // leal 0L(%edi,1),%edi
3824 '\x8d', '\xbc', '\x27',
3825 '\x00', '\x00', '\x00',
3827 const char nop14
[14] = { '\x8d', '\xb4', '\x26', // leal 0L(%esi,1),%esi
3828 '\x00', '\x00', '\x00', // leal 0L(%edi,1),%edi
3829 '\x00', '\x8d', '\xbc',
3830 '\x27', '\x00', '\x00',
3832 const char nop15
[15] = { '\xeb', '\x0d', '\x90', // jmp .+15
3833 '\x90', '\x90', '\x90', // nop,nop,nop,...
3834 '\x90', '\x90', '\x90',
3835 '\x90', '\x90', '\x90',
3836 '\x90', '\x90', '\x90' };
3838 const char* nops
[16] = {
3840 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
3841 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
3844 return std::string(nops
[length
], length
);
3847 // Return the value to use for the base of a DW_EH_PE_datarel offset
3848 // in an FDE. Solaris and SVR4 use DW_EH_PE_datarel because their
3849 // assembler can not write out the difference between two labels in
3850 // different sections, so instead of using a pc-relative value they
3851 // use an offset from the GOT.
3854 Target_i386::do_ehframe_datarel_base() const
3856 gold_assert(this->global_offset_table_
!= NULL
);
3857 Symbol
* sym
= this->global_offset_table_
;
3858 Sized_symbol
<32>* ssym
= static_cast<Sized_symbol
<32>*>(sym
);
3859 return ssym
->value();
3862 // Return whether SYM should be treated as a call to a non-split
3863 // function. We don't want that to be true of a call to a
3864 // get_pc_thunk function.
3867 Target_i386::do_is_call_to_non_split(const Symbol
* sym
, unsigned int) const
3869 return (sym
->type() == elfcpp::STT_FUNC
3870 && !is_prefix_of("__i686.get_pc_thunk.", sym
->name()));
3873 // FNOFFSET in section SHNDX in OBJECT is the start of a function
3874 // compiled with -fsplit-stack. The function calls non-split-stack
3875 // code. We have to change the function so that it always ensures
3876 // that it has enough stack space to run some random function.
3879 Target_i386::do_calls_non_split(Relobj
* object
, unsigned int shndx
,
3880 section_offset_type fnoffset
,
3881 section_size_type fnsize
,
3882 unsigned char* view
,
3883 section_size_type view_size
,
3885 std::string
* to
) const
3887 // The function starts with a comparison of the stack pointer and a
3888 // field in the TCB. This is followed by a jump.
3891 if (this->match_view(view
, view_size
, fnoffset
, "\x65\x3b\x25", 3)
3894 // We will call __morestack if the carry flag is set after this
3895 // comparison. We turn the comparison into an stc instruction
3897 view
[fnoffset
] = '\xf9';
3898 this->set_view_to_nop(view
, view_size
, fnoffset
+ 1, 6);
3900 // lea NN(%esp),%ecx
3901 // lea NN(%esp),%edx
3902 else if ((this->match_view(view
, view_size
, fnoffset
, "\x8d\x8c\x24", 3)
3903 || this->match_view(view
, view_size
, fnoffset
, "\x8d\x94\x24", 3))
3906 // This is loading an offset from the stack pointer for a
3907 // comparison. The offset is negative, so we decrease the
3908 // offset by the amount of space we need for the stack. This
3909 // means we will avoid calling __morestack if there happens to
3910 // be plenty of space on the stack already.
3911 unsigned char* pval
= view
+ fnoffset
+ 3;
3912 uint32_t val
= elfcpp::Swap_unaligned
<32, false>::readval(pval
);
3913 val
-= parameters
->options().split_stack_adjust_size();
3914 elfcpp::Swap_unaligned
<32, false>::writeval(pval
, val
);
3918 if (!object
->has_no_split_stack())
3919 object
->error(_("failed to match split-stack sequence at "
3920 "section %u offset %0zx"),
3921 shndx
, static_cast<size_t>(fnoffset
));
3925 // We have to change the function so that it calls
3926 // __morestack_non_split instead of __morestack. The former will
3927 // allocate additional stack space.
3928 *from
= "__morestack";
3929 *to
= "__morestack_non_split";
3932 // The selector for i386 object files. Note this is never instantiated
3933 // directly. It's only used in Target_selector_i386_nacl, below.
3935 class Target_selector_i386
: public Target_selector_freebsd
3938 Target_selector_i386()
3939 : Target_selector_freebsd(elfcpp::EM_386
, 32, false,
3940 "elf32-i386", "elf32-i386-freebsd",
3945 do_instantiate_target()
3946 { return new Target_i386(); }
3949 // NaCl variant. It uses different PLT contents.
3951 class Output_data_plt_i386_nacl
: public Output_data_plt_i386
3954 Output_data_plt_i386_nacl(Layout
* layout
,
3955 Output_data_got_plt_i386
* got_plt
,
3956 Output_data_space
* got_irelative
)
3957 : Output_data_plt_i386(layout
, plt_entry_size
, got_plt
, got_irelative
)
3961 virtual unsigned int
3962 do_get_plt_entry_size() const
3963 { return plt_entry_size
; }
3966 do_add_eh_frame(Layout
* layout
)
3968 layout
->add_eh_frame_for_plt(this, plt_eh_frame_cie
, plt_eh_frame_cie_size
,
3969 plt_eh_frame_fde
, plt_eh_frame_fde_size
);
3972 // The size of an entry in the PLT.
3973 static const int plt_entry_size
= 64;
3975 // The .eh_frame unwind information for the PLT.
3976 static const int plt_eh_frame_fde_size
= 32;
3977 static const unsigned char plt_eh_frame_fde
[plt_eh_frame_fde_size
];
3980 class Output_data_plt_i386_nacl_exec
: public Output_data_plt_i386_nacl
3983 Output_data_plt_i386_nacl_exec(Layout
* layout
,
3984 Output_data_got_plt_i386
* got_plt
,
3985 Output_data_space
* got_irelative
)
3986 : Output_data_plt_i386_nacl(layout
, got_plt
, got_irelative
)
3991 do_fill_first_plt_entry(unsigned char* pov
,
3992 elfcpp::Elf_types
<32>::Elf_Addr got_address
);
3994 virtual unsigned int
3995 do_fill_plt_entry(unsigned char* pov
,
3996 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
3997 unsigned int got_offset
,
3998 unsigned int plt_offset
,
3999 unsigned int plt_rel_offset
);
4002 // The first entry in the PLT for an executable.
4003 static const unsigned char first_plt_entry
[plt_entry_size
];
4005 // Other entries in the PLT for an executable.
4006 static const unsigned char plt_entry
[plt_entry_size
];
4009 class Output_data_plt_i386_nacl_dyn
: public Output_data_plt_i386_nacl
4012 Output_data_plt_i386_nacl_dyn(Layout
* layout
,
4013 Output_data_got_plt_i386
* got_plt
,
4014 Output_data_space
* got_irelative
)
4015 : Output_data_plt_i386_nacl(layout
, got_plt
, got_irelative
)
4020 do_fill_first_plt_entry(unsigned char* pov
, elfcpp::Elf_types
<32>::Elf_Addr
);
4022 virtual unsigned int
4023 do_fill_plt_entry(unsigned char* pov
,
4024 elfcpp::Elf_types
<32>::Elf_Addr
,
4025 unsigned int got_offset
,
4026 unsigned int plt_offset
,
4027 unsigned int plt_rel_offset
);
4030 // The first entry in the PLT for a shared object.
4031 static const unsigned char first_plt_entry
[plt_entry_size
];
4033 // Other entries in the PLT for a shared object.
4034 static const unsigned char plt_entry
[plt_entry_size
];
4037 class Target_i386_nacl
: public Target_i386
4041 : Target_i386(&i386_nacl_info
)
4045 virtual Output_data_plt_i386
*
4046 do_make_data_plt(Layout
* layout
,
4047 Output_data_got_plt_i386
* got_plt
,
4048 Output_data_space
* got_irelative
,
4052 return new Output_data_plt_i386_nacl_dyn(layout
, got_plt
, got_irelative
);
4054 return new Output_data_plt_i386_nacl_exec(layout
, got_plt
, got_irelative
);
4058 do_code_fill(section_size_type length
) const;
4061 static const Target::Target_info i386_nacl_info
;
4064 const Target::Target_info
Target_i386_nacl::i386_nacl_info
=
4067 false, // is_big_endian
4068 elfcpp::EM_386
, // machine_code
4069 false, // has_make_symbol
4070 false, // has_resolve
4071 true, // has_code_fill
4072 true, // is_default_stack_executable
4073 true, // can_icf_inline_merge_sections
4075 "/lib/ld-nacl-x86-32.so.1", // dynamic_linker
4076 0x20000, // default_text_segment_address
4077 0x10000, // abi_pagesize (overridable by -z max-page-size)
4078 0x10000, // common_pagesize (overridable by -z common-page-size)
4079 true, // isolate_execinstr
4080 0x10000000, // rosegment_gap
4081 elfcpp::SHN_UNDEF
, // small_common_shndx
4082 elfcpp::SHN_UNDEF
, // large_common_shndx
4083 0, // small_common_section_flags
4084 0, // large_common_section_flags
4085 NULL
, // attributes_section
4086 NULL
, // attributes_vendor
4087 "_start" // entry_symbol_name
4090 #define NACLMASK 0xe0 // 32-byte alignment mask
4093 Output_data_plt_i386_nacl_exec::first_plt_entry
[plt_entry_size
] =
4095 0xff, 0x35, // pushl contents of memory address
4096 0, 0, 0, 0, // replaced with address of .got + 4
4097 0x8b, 0x0d, // movl contents of address, %ecx
4098 0, 0, 0, 0, // replaced with address of .got + 8
4099 0x83, 0xe1, NACLMASK
, // andl $NACLMASK, %ecx
4100 0xff, 0xe1, // jmp *%ecx
4101 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4102 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4103 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4104 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4105 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4106 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4107 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4108 0x90, 0x90, 0x90, 0x90, 0x90
4112 Output_data_plt_i386_nacl_exec::do_fill_first_plt_entry(
4114 elfcpp::Elf_types
<32>::Elf_Addr got_address
)
4116 memcpy(pov
, first_plt_entry
, plt_entry_size
);
4117 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 4);
4118 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 8);
4121 // The first entry in the PLT for a shared object.
4124 Output_data_plt_i386_nacl_dyn::first_plt_entry
[plt_entry_size
] =
4126 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
4127 0x8b, 0x4b, 0x08, // mov 0x8(%ebx), %ecx
4128 0x83, 0xe1, NACLMASK
, // andl $NACLMASK, %ecx
4129 0xff, 0xe1, // jmp *%ecx
4130 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4131 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4132 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4133 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4134 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4135 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4136 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4137 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4138 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4139 0x90, 0x90, 0x90, 0x90, 0x90 // nops
4143 Output_data_plt_i386_nacl_dyn::do_fill_first_plt_entry(
4145 elfcpp::Elf_types
<32>::Elf_Addr
)
4147 memcpy(pov
, first_plt_entry
, plt_entry_size
);
4150 // Subsequent entries in the PLT for an executable.
4153 Output_data_plt_i386_nacl_exec::plt_entry
[plt_entry_size
] =
4155 0x8b, 0x0d, // movl contents of address, %ecx */
4156 0, 0, 0, 0, // replaced with address of symbol in .got
4157 0x83, 0xe1, NACLMASK
, // andl $NACLMASK, %ecx
4158 0xff, 0xe1, // jmp *%ecx
4160 // Pad to the next 32-byte boundary with nop instructions.
4162 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4163 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4165 // Lazy GOT entries point here (32-byte aligned).
4166 0x68, // pushl immediate
4167 0, 0, 0, 0, // replaced with offset into relocation table
4168 0xe9, // jmp relative
4169 0, 0, 0, 0, // replaced with offset to start of .plt
4171 // Pad to the next 32-byte boundary with nop instructions.
4172 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4173 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4178 Output_data_plt_i386_nacl_exec::do_fill_plt_entry(
4180 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
4181 unsigned int got_offset
,
4182 unsigned int plt_offset
,
4183 unsigned int plt_rel_offset
)
4185 memcpy(pov
, plt_entry
, plt_entry_size
);
4186 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
4187 got_address
+ got_offset
);
4188 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 33, plt_rel_offset
);
4189 elfcpp::Swap
<32, false>::writeval(pov
+ 38, - (plt_offset
+ 38 + 4));
4193 // Subsequent entries in the PLT for a shared object.
4196 Output_data_plt_i386_nacl_dyn::plt_entry
[plt_entry_size
] =
4198 0x8b, 0x8b, // movl offset(%ebx), %ecx
4199 0, 0, 0, 0, // replaced with offset of symbol in .got
4200 0x83, 0xe1, 0xe0, // andl $NACLMASK, %ecx
4201 0xff, 0xe1, // jmp *%ecx
4203 // Pad to the next 32-byte boundary with nop instructions.
4205 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4206 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4208 // Lazy GOT entries point here (32-byte aligned).
4209 0x68, // pushl immediate
4210 0, 0, 0, 0, // replaced with offset into relocation table.
4211 0xe9, // jmp relative
4212 0, 0, 0, 0, // replaced with offset to start of .plt.
4214 // Pad to the next 32-byte boundary with nop instructions.
4215 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4216 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4221 Output_data_plt_i386_nacl_dyn::do_fill_plt_entry(
4223 elfcpp::Elf_types
<32>::Elf_Addr
,
4224 unsigned int got_offset
,
4225 unsigned int plt_offset
,
4226 unsigned int plt_rel_offset
)
4228 memcpy(pov
, plt_entry
, plt_entry_size
);
4229 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
4230 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 33, plt_rel_offset
);
4231 elfcpp::Swap
<32, false>::writeval(pov
+ 38, - (plt_offset
+ 38 + 4));
4236 Output_data_plt_i386_nacl::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
4238 0, 0, 0, 0, // Replaced with offset to .plt.
4239 0, 0, 0, 0, // Replaced with size of .plt.
4240 0, // Augmentation size.
4241 elfcpp::DW_CFA_def_cfa_offset
, 8, // DW_CFA_def_cfa_offset: 8.
4242 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
4243 elfcpp::DW_CFA_def_cfa_offset
, 12, // DW_CFA_def_cfa_offset: 12.
4244 elfcpp::DW_CFA_advance_loc
+ 58, // Advance 58 to __PLT__ + 64.
4245 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
4246 13, // Block length.
4247 elfcpp::DW_OP_breg4
, 4, // Push %esp + 4.
4248 elfcpp::DW_OP_breg8
, 0, // Push %eip.
4249 elfcpp::DW_OP_const1u
, 63, // Push 0x3f.
4250 elfcpp::DW_OP_and
, // & (%eip & 0x3f).
4251 elfcpp::DW_OP_const1u
, 37, // Push 0x25.
4252 elfcpp::DW_OP_ge
, // >= ((%eip & 0x3f) >= 0x25)
4253 elfcpp::DW_OP_lit2
, // Push 2.
4254 elfcpp::DW_OP_shl
, // << (((%eip & 0x3f) >= 0x25) << 2)
4255 elfcpp::DW_OP_plus
, // + ((((%eip&0x3f)>=0x25)<<2)+%esp+4
4256 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
4260 // Return a string used to fill a code section with nops.
4261 // For NaCl, long NOPs are only valid if they do not cross
4262 // bundle alignment boundaries, so keep it simple with one-byte NOPs.
4264 Target_i386_nacl::do_code_fill(section_size_type length
) const
4266 return std::string(length
, static_cast<char>(0x90));
4269 // The selector for i386-nacl object files.
4271 class Target_selector_i386_nacl
4272 : public Target_selector_nacl
<Target_selector_i386
, Target_i386_nacl
>
4275 Target_selector_i386_nacl()
4276 : Target_selector_nacl
<Target_selector_i386
,
4277 Target_i386_nacl
>("x86-32",
4283 Target_selector_i386_nacl target_selector_i386
;
4285 // IAMCU variant. It uses EM_IAMCU, not EM_386.
4287 class Target_iamcu
: public Target_i386
4291 : Target_i386(&iamcu_info
)
4295 // Information about this specific target which we pass to the
4296 // general Target structure.
4297 static const Target::Target_info iamcu_info
;
4300 const Target::Target_info
Target_iamcu::iamcu_info
=
4303 false, // is_big_endian
4304 elfcpp::EM_IAMCU
, // machine_code
4305 false, // has_make_symbol
4306 false, // has_resolve
4307 true, // has_code_fill
4308 true, // is_default_stack_executable
4309 true, // can_icf_inline_merge_sections
4311 "/usr/lib/libc.so.1", // dynamic_linker
4312 0x08048000, // default_text_segment_address
4313 0x1000, // abi_pagesize (overridable by -z max-page-size)
4314 0x1000, // common_pagesize (overridable by -z common-page-size)
4315 false, // isolate_execinstr
4317 elfcpp::SHN_UNDEF
, // small_common_shndx
4318 elfcpp::SHN_UNDEF
, // large_common_shndx
4319 0, // small_common_section_flags
4320 0, // large_common_section_flags
4321 NULL
, // attributes_section
4322 NULL
, // attributes_vendor
4323 "_start" // entry_symbol_name
4326 class Target_selector_iamcu
: public Target_selector
4329 Target_selector_iamcu()
4330 : Target_selector(elfcpp::EM_IAMCU
, 32, false, "elf32-iamcu",
4335 do_instantiate_target()
4336 { return new Target_iamcu(); }
4339 Target_selector_iamcu target_selector_iamcu
;
4341 } // End anonymous namespace.