1 // i386.cc -- i386 target support for gold.
3 // Copyright 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013
4 // Free Software Foundation, Inc.
5 // Written by Ian Lance Taylor <iant@google.com>.
7 // This file is part of gold.
9 // This program is free software; you can redistribute it and/or modify
10 // it under the terms of the GNU General Public License as published by
11 // the Free Software Foundation; either version 3 of the License, or
12 // (at your option) any later version.
14 // This program is distributed in the hope that it will be useful,
15 // but WITHOUT ANY WARRANTY; without even the implied warranty of
16 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 // GNU General Public License for more details.
19 // You should have received a copy of the GNU General Public License
20 // along with this program; if not, write to the Free Software
21 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
22 // MA 02110-1301, USA.
30 #include "parameters.h"
37 #include "copy-relocs.h"
39 #include "target-reloc.h"
40 #include "target-select.h"
51 // A class to handle the PLT data.
52 // This is an abstract base class that handles most of the linker details
53 // but does not know the actual contents of PLT entries. The derived
54 // classes below fill in those details.
56 class Output_data_plt_i386
: public Output_section_data
59 typedef Output_data_reloc
<elfcpp::SHT_REL
, true, 32, false> Reloc_section
;
61 Output_data_plt_i386(Layout
*, uint64_t addralign
,
62 Output_data_space
*, Output_data_space
*);
64 // Add an entry to the PLT.
66 add_entry(Symbol_table
*, Layout
*, Symbol
* gsym
);
68 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
70 add_local_ifunc_entry(Symbol_table
*, Layout
*,
71 Sized_relobj_file
<32, false>* relobj
,
72 unsigned int local_sym_index
);
74 // Return the .rel.plt section data.
77 { return this->rel_
; }
79 // Return where the TLS_DESC relocations should go.
81 rel_tls_desc(Layout
*);
83 // Return where the IRELATIVE relocations should go.
85 rel_irelative(Symbol_table
*, Layout
*);
87 // Return whether we created a section for IRELATIVE relocations.
89 has_irelative_section() const
90 { return this->irelative_rel_
!= NULL
; }
92 // Return the number of PLT entries.
95 { return this->count_
+ this->irelative_count_
; }
97 // Return the offset of the first non-reserved PLT entry.
99 first_plt_entry_offset()
100 { return this->get_plt_entry_size(); }
102 // Return the size of a PLT entry.
104 get_plt_entry_size() const
105 { return this->do_get_plt_entry_size(); }
107 // Return the PLT address to use for a global symbol.
109 address_for_global(const Symbol
*);
111 // Return the PLT address to use for a local symbol.
113 address_for_local(const Relobj
*, unsigned int symndx
);
115 // Add .eh_frame information for the PLT.
117 add_eh_frame(Layout
* layout
)
118 { this->do_add_eh_frame(layout
); }
121 // Fill the first PLT entry, given the pointer to the PLT section data
122 // and the runtime address of the GOT.
124 fill_first_plt_entry(unsigned char* pov
,
125 elfcpp::Elf_types
<32>::Elf_Addr got_address
)
126 { this->do_fill_first_plt_entry(pov
, got_address
); }
128 // Fill a normal PLT entry, given the pointer to the entry's data in the
129 // section, the runtime address of the GOT, the offset into the GOT of
130 // the corresponding slot, the offset into the relocation section of the
131 // corresponding reloc, and the offset of this entry within the whole
132 // PLT. Return the offset from this PLT entry's runtime address that
133 // should be used to compute the initial value of the GOT slot.
135 fill_plt_entry(unsigned char* pov
,
136 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
137 unsigned int got_offset
,
138 unsigned int plt_offset
,
139 unsigned int plt_rel_offset
)
141 return this->do_fill_plt_entry(pov
, got_address
, got_offset
,
142 plt_offset
, plt_rel_offset
);
146 do_get_plt_entry_size() const = 0;
149 do_fill_first_plt_entry(unsigned char* pov
,
150 elfcpp::Elf_types
<32>::Elf_Addr got_address
) = 0;
153 do_fill_plt_entry(unsigned char* pov
,
154 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
155 unsigned int got_offset
,
156 unsigned int plt_offset
,
157 unsigned int plt_rel_offset
) = 0;
160 do_add_eh_frame(Layout
*) = 0;
163 do_adjust_output_section(Output_section
* os
);
165 // Write to a map file.
167 do_print_to_mapfile(Mapfile
* mapfile
) const
168 { mapfile
->print_output_data(this, _("** PLT")); }
170 // The .eh_frame unwind information for the PLT.
171 // The CIE is common across variants of the PLT format.
172 static const int plt_eh_frame_cie_size
= 16;
173 static const unsigned char plt_eh_frame_cie
[plt_eh_frame_cie_size
];
176 // Set the final size.
178 set_final_data_size()
180 this->set_data_size((this->count_
+ this->irelative_count_
+ 1)
181 * this->get_plt_entry_size());
184 // Write out the PLT data.
186 do_write(Output_file
*);
188 // We keep a list of global STT_GNU_IFUNC symbols, each with its
189 // offset in the GOT.
193 unsigned int got_offset
;
196 // We keep a list of local STT_GNU_IFUNC symbols, each with its
197 // offset in the GOT.
200 Sized_relobj_file
<32, false>* object
;
201 unsigned int local_sym_index
;
202 unsigned int got_offset
;
205 // A pointer to the Layout class, so that we can find the .dynamic
206 // section when we write out the GOT PLT section.
208 // The reloc section.
210 // The TLS_DESC relocations, if necessary. These must follow the
211 // regular PLT relocs.
212 Reloc_section
* tls_desc_rel_
;
213 // The IRELATIVE relocations, if necessary. These must follow the
214 // regular relocatoins and the TLS_DESC relocations.
215 Reloc_section
* irelative_rel_
;
216 // The .got.plt section.
217 Output_data_space
* got_plt_
;
218 // The part of the .got.plt section used for IRELATIVE relocs.
219 Output_data_space
* got_irelative_
;
220 // The number of PLT entries.
222 // Number of PLT entries with R_386_IRELATIVE relocs. These follow
223 // the regular PLT entries.
224 unsigned int irelative_count_
;
225 // Global STT_GNU_IFUNC symbols.
226 std::vector
<Global_ifunc
> global_ifuncs_
;
227 // Local STT_GNU_IFUNC symbols.
228 std::vector
<Local_ifunc
> local_ifuncs_
;
231 // This is an abstract class for the standard PLT layout.
232 // The derived classes below handle the actual PLT contents
233 // for the executable (non-PIC) and shared-library (PIC) cases.
234 // The unwind information is uniform across those two, so it's here.
236 class Output_data_plt_i386_standard
: public Output_data_plt_i386
239 Output_data_plt_i386_standard(Layout
* layout
,
240 Output_data_space
* got_plt
,
241 Output_data_space
* got_irelative
)
242 : Output_data_plt_i386(layout
, plt_entry_size
, got_plt
, got_irelative
)
247 do_get_plt_entry_size() const
248 { return plt_entry_size
; }
251 do_add_eh_frame(Layout
* layout
)
253 layout
->add_eh_frame_for_plt(this, plt_eh_frame_cie
, plt_eh_frame_cie_size
,
254 plt_eh_frame_fde
, plt_eh_frame_fde_size
);
257 // The size of an entry in the PLT.
258 static const int plt_entry_size
= 16;
260 // The .eh_frame unwind information for the PLT.
261 static const int plt_eh_frame_fde_size
= 32;
262 static const unsigned char plt_eh_frame_fde
[plt_eh_frame_fde_size
];
265 // Actually fill the PLT contents for an executable (non-PIC).
267 class Output_data_plt_i386_exec
: public Output_data_plt_i386_standard
270 Output_data_plt_i386_exec(Layout
* layout
,
271 Output_data_space
* got_plt
,
272 Output_data_space
* got_irelative
)
273 : Output_data_plt_i386_standard(layout
, got_plt
, got_irelative
)
278 do_fill_first_plt_entry(unsigned char* pov
,
279 elfcpp::Elf_types
<32>::Elf_Addr got_address
);
282 do_fill_plt_entry(unsigned char* pov
,
283 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
284 unsigned int got_offset
,
285 unsigned int plt_offset
,
286 unsigned int plt_rel_offset
);
289 // The first entry in the PLT for an executable.
290 static const unsigned char first_plt_entry
[plt_entry_size
];
292 // Other entries in the PLT for an executable.
293 static const unsigned char plt_entry
[plt_entry_size
];
296 // Actually fill the PLT contents for a shared library (PIC).
298 class Output_data_plt_i386_dyn
: public Output_data_plt_i386_standard
301 Output_data_plt_i386_dyn(Layout
* layout
,
302 Output_data_space
* got_plt
,
303 Output_data_space
* got_irelative
)
304 : Output_data_plt_i386_standard(layout
, got_plt
, got_irelative
)
309 do_fill_first_plt_entry(unsigned char* pov
, elfcpp::Elf_types
<32>::Elf_Addr
);
312 do_fill_plt_entry(unsigned char* pov
,
313 elfcpp::Elf_types
<32>::Elf_Addr
,
314 unsigned int got_offset
,
315 unsigned int plt_offset
,
316 unsigned int plt_rel_offset
);
319 // The first entry in the PLT for a shared object.
320 static const unsigned char first_plt_entry
[plt_entry_size
];
322 // Other entries in the PLT for a shared object.
323 static const unsigned char plt_entry
[plt_entry_size
];
326 // The i386 target class.
327 // TLS info comes from
328 // http://people.redhat.com/drepper/tls.pdf
329 // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
331 class Target_i386
: public Sized_target
<32, false>
334 typedef Output_data_reloc
<elfcpp::SHT_REL
, true, 32, false> Reloc_section
;
336 Target_i386(const Target::Target_info
* info
= &i386_info
)
337 : Sized_target
<32, false>(info
),
338 got_(NULL
), plt_(NULL
), got_plt_(NULL
), got_irelative_(NULL
),
339 got_tlsdesc_(NULL
), global_offset_table_(NULL
), rel_dyn_(NULL
),
340 rel_irelative_(NULL
), copy_relocs_(elfcpp::R_386_COPY
), dynbss_(NULL
),
341 got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
344 // Process the relocations to determine unreferenced sections for
345 // garbage collection.
347 gc_process_relocs(Symbol_table
* symtab
,
349 Sized_relobj_file
<32, false>* object
,
350 unsigned int data_shndx
,
351 unsigned int sh_type
,
352 const unsigned char* prelocs
,
354 Output_section
* output_section
,
355 bool needs_special_offset_handling
,
356 size_t local_symbol_count
,
357 const unsigned char* plocal_symbols
);
359 // Scan the relocations to look for symbol adjustments.
361 scan_relocs(Symbol_table
* symtab
,
363 Sized_relobj_file
<32, false>* object
,
364 unsigned int data_shndx
,
365 unsigned int sh_type
,
366 const unsigned char* prelocs
,
368 Output_section
* output_section
,
369 bool needs_special_offset_handling
,
370 size_t local_symbol_count
,
371 const unsigned char* plocal_symbols
);
373 // Finalize the sections.
375 do_finalize_sections(Layout
*, const Input_objects
*, Symbol_table
*);
377 // Return the value to use for a dynamic which requires special
380 do_dynsym_value(const Symbol
*) const;
382 // Relocate a section.
384 relocate_section(const Relocate_info
<32, false>*,
385 unsigned int sh_type
,
386 const unsigned char* prelocs
,
388 Output_section
* output_section
,
389 bool needs_special_offset_handling
,
391 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
392 section_size_type view_size
,
393 const Reloc_symbol_changes
*);
395 // Scan the relocs during a relocatable link.
397 scan_relocatable_relocs(Symbol_table
* symtab
,
399 Sized_relobj_file
<32, false>* object
,
400 unsigned int data_shndx
,
401 unsigned int sh_type
,
402 const unsigned char* prelocs
,
404 Output_section
* output_section
,
405 bool needs_special_offset_handling
,
406 size_t local_symbol_count
,
407 const unsigned char* plocal_symbols
,
408 Relocatable_relocs
*);
410 // Emit relocations for a section.
412 relocate_relocs(const Relocate_info
<32, false>*,
413 unsigned int sh_type
,
414 const unsigned char* prelocs
,
416 Output_section
* output_section
,
417 elfcpp::Elf_types
<32>::Elf_Off offset_in_output_section
,
418 const Relocatable_relocs
*,
420 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
421 section_size_type view_size
,
422 unsigned char* reloc_view
,
423 section_size_type reloc_view_size
);
425 // Return a string used to fill a code section with nops.
427 do_code_fill(section_size_type length
) const;
429 // Return whether SYM is defined by the ABI.
431 do_is_defined_by_abi(const Symbol
* sym
) const
432 { return strcmp(sym
->name(), "___tls_get_addr") == 0; }
434 // Return whether a symbol name implies a local label. The UnixWare
435 // 2.1 cc generates temporary symbols that start with .X, so we
436 // recognize them here. FIXME: do other SVR4 compilers also use .X?.
437 // If so, we should move the .X recognition into
438 // Target::do_is_local_label_name.
440 do_is_local_label_name(const char* name
) const
442 if (name
[0] == '.' && name
[1] == 'X')
444 return Target::do_is_local_label_name(name
);
447 // Return the PLT address to use for a global symbol.
449 do_plt_address_for_global(const Symbol
* gsym
) const
450 { return this->plt_section()->address_for_global(gsym
); }
453 do_plt_address_for_local(const Relobj
* relobj
, unsigned int symndx
) const
454 { return this->plt_section()->address_for_local(relobj
, symndx
); }
456 // We can tell whether we take the address of a function.
458 do_can_check_for_function_pointers() const
461 // Return the base for a DW_EH_PE_datarel encoding.
463 do_ehframe_datarel_base() const;
465 // Return whether SYM is call to a non-split function.
467 do_is_call_to_non_split(const Symbol
* sym
, unsigned int) const;
469 // Adjust -fsplit-stack code which calls non-split-stack code.
471 do_calls_non_split(Relobj
* object
, unsigned int shndx
,
472 section_offset_type fnoffset
, section_size_type fnsize
,
473 unsigned char* view
, section_size_type view_size
,
474 std::string
* from
, std::string
* to
) const;
476 // Return the size of the GOT section.
480 gold_assert(this->got_
!= NULL
);
481 return this->got_
->data_size();
484 // Return the number of entries in the GOT.
486 got_entry_count() const
488 if (this->got_
== NULL
)
490 return this->got_size() / 4;
493 // Return the number of entries in the PLT.
495 plt_entry_count() const;
497 // Return the offset of the first non-reserved PLT entry.
499 first_plt_entry_offset() const;
501 // Return the size of each PLT entry.
503 plt_entry_size() const;
506 // Instantiate the plt_ member.
507 // This chooses the right PLT flavor for an executable or a shared object.
508 Output_data_plt_i386
*
509 make_data_plt(Layout
* layout
,
510 Output_data_space
* got_plt
,
511 Output_data_space
* got_irelative
,
513 { return this->do_make_data_plt(layout
, got_plt
, got_irelative
, dyn
); }
515 virtual Output_data_plt_i386
*
516 do_make_data_plt(Layout
* layout
,
517 Output_data_space
* got_plt
,
518 Output_data_space
* got_irelative
,
522 return new Output_data_plt_i386_dyn(layout
, got_plt
, got_irelative
);
524 return new Output_data_plt_i386_exec(layout
, got_plt
, got_irelative
);
528 // The class which scans relocations.
533 get_reference_flags(unsigned int r_type
);
536 local(Symbol_table
* symtab
, Layout
* layout
, Target_i386
* target
,
537 Sized_relobj_file
<32, false>* object
,
538 unsigned int data_shndx
,
539 Output_section
* output_section
,
540 const elfcpp::Rel
<32, false>& reloc
, unsigned int r_type
,
541 const elfcpp::Sym
<32, false>& lsym
,
545 global(Symbol_table
* symtab
, Layout
* layout
, Target_i386
* target
,
546 Sized_relobj_file
<32, false>* object
,
547 unsigned int data_shndx
,
548 Output_section
* output_section
,
549 const elfcpp::Rel
<32, false>& reloc
, unsigned int r_type
,
553 local_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
555 Sized_relobj_file
<32, false>* object
,
556 unsigned int data_shndx
,
557 Output_section
* output_section
,
558 const elfcpp::Rel
<32, false>& reloc
,
560 const elfcpp::Sym
<32, false>& lsym
);
563 global_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
565 Sized_relobj_file
<32, false>* object
,
566 unsigned int data_shndx
,
567 Output_section
* output_section
,
568 const elfcpp::Rel
<32, false>& reloc
,
573 possible_function_pointer_reloc(unsigned int r_type
);
576 reloc_needs_plt_for_ifunc(Sized_relobj_file
<32, false>*,
577 unsigned int r_type
);
580 unsupported_reloc_local(Sized_relobj_file
<32, false>*, unsigned int r_type
);
583 unsupported_reloc_global(Sized_relobj_file
<32, false>*, unsigned int r_type
,
587 // The class which implements relocation.
592 : skip_call_tls_get_addr_(false),
593 local_dynamic_type_(LOCAL_DYNAMIC_NONE
)
598 if (this->skip_call_tls_get_addr_
)
600 // FIXME: This needs to specify the location somehow.
601 gold_error(_("missing expected TLS relocation"));
605 // Return whether the static relocation needs to be applied.
607 should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
610 Output_section
* output_section
);
612 // Do a relocation. Return false if the caller should not issue
613 // any warnings about this relocation.
615 relocate(const Relocate_info
<32, false>*, Target_i386
*, Output_section
*,
616 size_t relnum
, const elfcpp::Rel
<32, false>&,
617 unsigned int r_type
, const Sized_symbol
<32>*,
618 const Symbol_value
<32>*,
619 unsigned char*, elfcpp::Elf_types
<32>::Elf_Addr
,
623 // Do a TLS relocation.
625 relocate_tls(const Relocate_info
<32, false>*, Target_i386
* target
,
626 size_t relnum
, const elfcpp::Rel
<32, false>&,
627 unsigned int r_type
, const Sized_symbol
<32>*,
628 const Symbol_value
<32>*,
629 unsigned char*, elfcpp::Elf_types
<32>::Elf_Addr
,
632 // Do a TLS General-Dynamic to Initial-Exec transition.
634 tls_gd_to_ie(const Relocate_info
<32, false>*, size_t relnum
,
635 Output_segment
* tls_segment
,
636 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
637 elfcpp::Elf_types
<32>::Elf_Addr value
,
639 section_size_type view_size
);
641 // Do a TLS General-Dynamic to Local-Exec transition.
643 tls_gd_to_le(const Relocate_info
<32, false>*, size_t relnum
,
644 Output_segment
* tls_segment
,
645 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
646 elfcpp::Elf_types
<32>::Elf_Addr value
,
648 section_size_type view_size
);
650 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
653 tls_desc_gd_to_ie(const Relocate_info
<32, false>*, size_t relnum
,
654 Output_segment
* tls_segment
,
655 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
656 elfcpp::Elf_types
<32>::Elf_Addr value
,
658 section_size_type view_size
);
660 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
663 tls_desc_gd_to_le(const Relocate_info
<32, false>*, size_t relnum
,
664 Output_segment
* tls_segment
,
665 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
666 elfcpp::Elf_types
<32>::Elf_Addr value
,
668 section_size_type view_size
);
670 // Do a TLS Local-Dynamic to Local-Exec transition.
672 tls_ld_to_le(const Relocate_info
<32, false>*, size_t relnum
,
673 Output_segment
* tls_segment
,
674 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
675 elfcpp::Elf_types
<32>::Elf_Addr value
,
677 section_size_type view_size
);
679 // Do a TLS Initial-Exec to Local-Exec transition.
681 tls_ie_to_le(const Relocate_info
<32, false>*, size_t relnum
,
682 Output_segment
* tls_segment
,
683 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
684 elfcpp::Elf_types
<32>::Elf_Addr value
,
686 section_size_type view_size
);
688 // We need to keep track of which type of local dynamic relocation
689 // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
690 enum Local_dynamic_type
697 // This is set if we should skip the next reloc, which should be a
698 // PLT32 reloc against ___tls_get_addr.
699 bool skip_call_tls_get_addr_
;
700 // The type of local dynamic relocation we have seen in the section
701 // being relocated, if any.
702 Local_dynamic_type local_dynamic_type_
;
705 // A class which returns the size required for a relocation type,
706 // used while scanning relocs during a relocatable link.
707 class Relocatable_size_for_reloc
711 get_size_for_reloc(unsigned int, Relobj
*);
714 // Adjust TLS relocation type based on the options and whether this
715 // is a local symbol.
716 static tls::Tls_optimization
717 optimize_tls_reloc(bool is_final
, int r_type
);
719 // Get the GOT section, creating it if necessary.
720 Output_data_got
<32, false>*
721 got_section(Symbol_table
*, Layout
*);
723 // Get the GOT PLT section.
725 got_plt_section() const
727 gold_assert(this->got_plt_
!= NULL
);
728 return this->got_plt_
;
731 // Get the GOT section for TLSDESC entries.
732 Output_data_got
<32, false>*
733 got_tlsdesc_section() const
735 gold_assert(this->got_tlsdesc_
!= NULL
);
736 return this->got_tlsdesc_
;
739 // Create the PLT section.
741 make_plt_section(Symbol_table
* symtab
, Layout
* layout
);
743 // Create a PLT entry for a global symbol.
745 make_plt_entry(Symbol_table
*, Layout
*, Symbol
*);
747 // Create a PLT entry for a local STT_GNU_IFUNC symbol.
749 make_local_ifunc_plt_entry(Symbol_table
*, Layout
*,
750 Sized_relobj_file
<32, false>* relobj
,
751 unsigned int local_sym_index
);
753 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
755 define_tls_base_symbol(Symbol_table
*, Layout
*);
757 // Create a GOT entry for the TLS module index.
759 got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
760 Sized_relobj_file
<32, false>* object
);
762 // Get the PLT section.
763 Output_data_plt_i386
*
766 gold_assert(this->plt_
!= NULL
);
770 // Get the dynamic reloc section, creating it if necessary.
772 rel_dyn_section(Layout
*);
774 // Get the section to use for TLS_DESC relocations.
776 rel_tls_desc_section(Layout
*) const;
778 // Get the section to use for IRELATIVE relocations.
780 rel_irelative_section(Layout
*);
782 // Add a potential copy relocation.
784 copy_reloc(Symbol_table
* symtab
, Layout
* layout
,
785 Sized_relobj_file
<32, false>* object
,
786 unsigned int shndx
, Output_section
* output_section
,
787 Symbol
* sym
, const elfcpp::Rel
<32, false>& reloc
)
789 this->copy_relocs_
.copy_reloc(symtab
, layout
,
790 symtab
->get_sized_symbol
<32>(sym
),
791 object
, shndx
, output_section
, reloc
,
792 this->rel_dyn_section(layout
));
795 // Information about this specific target which we pass to the
796 // general Target structure.
797 static const Target::Target_info i386_info
;
799 // The types of GOT entries needed for this platform.
800 // These values are exposed to the ABI in an incremental link.
801 // Do not renumber existing values without changing the version
802 // number of the .gnu_incremental_inputs section.
805 GOT_TYPE_STANDARD
= 0, // GOT entry for a regular symbol
806 GOT_TYPE_TLS_NOFFSET
= 1, // GOT entry for negative TLS offset
807 GOT_TYPE_TLS_OFFSET
= 2, // GOT entry for positive TLS offset
808 GOT_TYPE_TLS_PAIR
= 3, // GOT entry for TLS module/offset pair
809 GOT_TYPE_TLS_DESC
= 4 // GOT entry for TLS_DESC pair
813 Output_data_got
<32, false>* got_
;
815 Output_data_plt_i386
* plt_
;
816 // The GOT PLT section.
817 Output_data_space
* got_plt_
;
818 // The GOT section for IRELATIVE relocations.
819 Output_data_space
* got_irelative_
;
820 // The GOT section for TLSDESC relocations.
821 Output_data_got
<32, false>* got_tlsdesc_
;
822 // The _GLOBAL_OFFSET_TABLE_ symbol.
823 Symbol
* global_offset_table_
;
824 // The dynamic reloc section.
825 Reloc_section
* rel_dyn_
;
826 // The section to use for IRELATIVE relocs.
827 Reloc_section
* rel_irelative_
;
828 // Relocs saved to avoid a COPY reloc.
829 Copy_relocs
<elfcpp::SHT_REL
, 32, false> copy_relocs_
;
830 // Space for variables copied with a COPY reloc.
831 Output_data_space
* dynbss_
;
832 // Offset of the GOT entry for the TLS module index.
833 unsigned int got_mod_index_offset_
;
834 // True if the _TLS_MODULE_BASE_ symbol has been defined.
835 bool tls_base_symbol_defined_
;
838 const Target::Target_info
Target_i386::i386_info
=
841 false, // is_big_endian
842 elfcpp::EM_386
, // machine_code
843 false, // has_make_symbol
844 false, // has_resolve
845 true, // has_code_fill
846 true, // is_default_stack_executable
847 true, // can_icf_inline_merge_sections
849 "/usr/lib/libc.so.1", // dynamic_linker
850 0x08048000, // default_text_segment_address
851 0x1000, // abi_pagesize (overridable by -z max-page-size)
852 0x1000, // common_pagesize (overridable by -z common-page-size)
853 false, // isolate_execinstr
855 elfcpp::SHN_UNDEF
, // small_common_shndx
856 elfcpp::SHN_UNDEF
, // large_common_shndx
857 0, // small_common_section_flags
858 0, // large_common_section_flags
859 NULL
, // attributes_section
860 NULL
, // attributes_vendor
861 "_start" // entry_symbol_name
864 // Get the GOT section, creating it if necessary.
866 Output_data_got
<32, false>*
867 Target_i386::got_section(Symbol_table
* symtab
, Layout
* layout
)
869 if (this->got_
== NULL
)
871 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
873 this->got_
= new Output_data_got
<32, false>();
875 // When using -z now, we can treat .got.plt as a relro section.
876 // Without -z now, it is modified after program startup by lazy
878 bool is_got_plt_relro
= parameters
->options().now();
879 Output_section_order got_order
= (is_got_plt_relro
882 Output_section_order got_plt_order
= (is_got_plt_relro
884 : ORDER_NON_RELRO_FIRST
);
886 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
888 | elfcpp::SHF_WRITE
),
889 this->got_
, got_order
, true);
891 this->got_plt_
= new Output_data_space(4, "** GOT PLT");
892 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
894 | elfcpp::SHF_WRITE
),
895 this->got_plt_
, got_plt_order
,
898 // The first three entries are reserved.
899 this->got_plt_
->set_current_data_size(3 * 4);
901 if (!is_got_plt_relro
)
903 // Those bytes can go into the relro segment.
904 layout
->increase_relro(3 * 4);
907 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
908 this->global_offset_table_
=
909 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
910 Symbol_table::PREDEFINED
,
912 0, 0, elfcpp::STT_OBJECT
,
914 elfcpp::STV_HIDDEN
, 0,
917 // If there are any IRELATIVE relocations, they get GOT entries
918 // in .got.plt after the jump slot relocations.
919 this->got_irelative_
= new Output_data_space(4, "** GOT IRELATIVE PLT");
920 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
922 | elfcpp::SHF_WRITE
),
923 this->got_irelative_
,
924 got_plt_order
, is_got_plt_relro
);
926 // If there are any TLSDESC relocations, they get GOT entries in
927 // .got.plt after the jump slot entries.
928 this->got_tlsdesc_
= new Output_data_got
<32, false>();
929 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
931 | elfcpp::SHF_WRITE
),
933 got_plt_order
, is_got_plt_relro
);
939 // Get the dynamic reloc section, creating it if necessary.
941 Target_i386::Reloc_section
*
942 Target_i386::rel_dyn_section(Layout
* layout
)
944 if (this->rel_dyn_
== NULL
)
946 gold_assert(layout
!= NULL
);
947 this->rel_dyn_
= new Reloc_section(parameters
->options().combreloc());
948 layout
->add_output_section_data(".rel.dyn", elfcpp::SHT_REL
,
949 elfcpp::SHF_ALLOC
, this->rel_dyn_
,
950 ORDER_DYNAMIC_RELOCS
, false);
952 return this->rel_dyn_
;
955 // Get the section to use for IRELATIVE relocs, creating it if
956 // necessary. These go in .rel.dyn, but only after all other dynamic
957 // relocations. They need to follow the other dynamic relocations so
958 // that they can refer to global variables initialized by those
961 Target_i386::Reloc_section
*
962 Target_i386::rel_irelative_section(Layout
* layout
)
964 if (this->rel_irelative_
== NULL
)
966 // Make sure we have already create the dynamic reloc section.
967 this->rel_dyn_section(layout
);
968 this->rel_irelative_
= new Reloc_section(false);
969 layout
->add_output_section_data(".rel.dyn", elfcpp::SHT_REL
,
970 elfcpp::SHF_ALLOC
, this->rel_irelative_
,
971 ORDER_DYNAMIC_RELOCS
, false);
972 gold_assert(this->rel_dyn_
->output_section()
973 == this->rel_irelative_
->output_section());
975 return this->rel_irelative_
;
978 // Create the PLT section. The ordinary .got section is an argument,
979 // since we need to refer to the start. We also create our own .got
980 // section just for PLT entries.
982 Output_data_plt_i386::Output_data_plt_i386(Layout
* layout
,
984 Output_data_space
* got_plt
,
985 Output_data_space
* got_irelative
)
986 : Output_section_data(addralign
),
987 layout_(layout
), tls_desc_rel_(NULL
),
988 irelative_rel_(NULL
), got_plt_(got_plt
), got_irelative_(got_irelative
),
989 count_(0), irelative_count_(0), global_ifuncs_(), local_ifuncs_()
991 this->rel_
= new Reloc_section(false);
992 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
993 elfcpp::SHF_ALLOC
, this->rel_
,
994 ORDER_DYNAMIC_PLT_RELOCS
, false);
998 Output_data_plt_i386::do_adjust_output_section(Output_section
* os
)
1000 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
1001 // linker, and so do we.
1005 // Add an entry to the PLT.
1008 Output_data_plt_i386::add_entry(Symbol_table
* symtab
, Layout
* layout
,
1011 gold_assert(!gsym
->has_plt_offset());
1013 // Every PLT entry needs a reloc.
1014 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1015 && gsym
->can_use_relative_reloc(false))
1017 gsym
->set_plt_offset(this->irelative_count_
* this->get_plt_entry_size());
1018 ++this->irelative_count_
;
1019 section_offset_type got_offset
=
1020 this->got_irelative_
->current_data_size();
1021 this->got_irelative_
->set_current_data_size(got_offset
+ 4);
1022 Reloc_section
* rel
= this->rel_irelative(symtab
, layout
);
1023 rel
->add_symbolless_global_addend(gsym
, elfcpp::R_386_IRELATIVE
,
1024 this->got_irelative_
, got_offset
);
1025 struct Global_ifunc gi
;
1027 gi
.got_offset
= got_offset
;
1028 this->global_ifuncs_
.push_back(gi
);
1032 // When setting the PLT offset we skip the initial reserved PLT
1034 gsym
->set_plt_offset((this->count_
+ 1) * this->get_plt_entry_size());
1038 section_offset_type got_offset
= this->got_plt_
->current_data_size();
1040 // Every PLT entry needs a GOT entry which points back to the
1041 // PLT entry (this will be changed by the dynamic linker,
1042 // normally lazily when the function is called).
1043 this->got_plt_
->set_current_data_size(got_offset
+ 4);
1045 gsym
->set_needs_dynsym_entry();
1046 this->rel_
->add_global(gsym
, elfcpp::R_386_JUMP_SLOT
, this->got_plt_
,
1050 // Note that we don't need to save the symbol. The contents of the
1051 // PLT are independent of which symbols are used. The symbols only
1052 // appear in the relocations.
1055 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
1059 Output_data_plt_i386::add_local_ifunc_entry(
1060 Symbol_table
* symtab
,
1062 Sized_relobj_file
<32, false>* relobj
,
1063 unsigned int local_sym_index
)
1065 unsigned int plt_offset
= this->irelative_count_
* this->get_plt_entry_size();
1066 ++this->irelative_count_
;
1068 section_offset_type got_offset
= this->got_irelative_
->current_data_size();
1070 // Every PLT entry needs a GOT entry which points back to the PLT
1072 this->got_irelative_
->set_current_data_size(got_offset
+ 4);
1074 // Every PLT entry needs a reloc.
1075 Reloc_section
* rel
= this->rel_irelative(symtab
, layout
);
1076 rel
->add_symbolless_local_addend(relobj
, local_sym_index
,
1077 elfcpp::R_386_IRELATIVE
,
1078 this->got_irelative_
, got_offset
);
1080 struct Local_ifunc li
;
1082 li
.local_sym_index
= local_sym_index
;
1083 li
.got_offset
= got_offset
;
1084 this->local_ifuncs_
.push_back(li
);
1089 // Return where the TLS_DESC relocations should go, creating it if
1090 // necessary. These follow the JUMP_SLOT relocations.
1092 Output_data_plt_i386::Reloc_section
*
1093 Output_data_plt_i386::rel_tls_desc(Layout
* layout
)
1095 if (this->tls_desc_rel_
== NULL
)
1097 this->tls_desc_rel_
= new Reloc_section(false);
1098 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
1099 elfcpp::SHF_ALLOC
, this->tls_desc_rel_
,
1100 ORDER_DYNAMIC_PLT_RELOCS
, false);
1101 gold_assert(this->tls_desc_rel_
->output_section()
1102 == this->rel_
->output_section());
1104 return this->tls_desc_rel_
;
1107 // Return where the IRELATIVE relocations should go in the PLT. These
1108 // follow the JUMP_SLOT and TLS_DESC relocations.
1110 Output_data_plt_i386::Reloc_section
*
1111 Output_data_plt_i386::rel_irelative(Symbol_table
* symtab
, Layout
* layout
)
1113 if (this->irelative_rel_
== NULL
)
1115 // Make sure we have a place for the TLS_DESC relocations, in
1116 // case we see any later on.
1117 this->rel_tls_desc(layout
);
1118 this->irelative_rel_
= new Reloc_section(false);
1119 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
1120 elfcpp::SHF_ALLOC
, this->irelative_rel_
,
1121 ORDER_DYNAMIC_PLT_RELOCS
, false);
1122 gold_assert(this->irelative_rel_
->output_section()
1123 == this->rel_
->output_section());
1125 if (parameters
->doing_static_link())
1127 // A statically linked executable will only have a .rel.plt
1128 // section to hold R_386_IRELATIVE relocs for STT_GNU_IFUNC
1129 // symbols. The library will use these symbols to locate
1130 // the IRELATIVE relocs at program startup time.
1131 symtab
->define_in_output_data("__rel_iplt_start", NULL
,
1132 Symbol_table::PREDEFINED
,
1133 this->irelative_rel_
, 0, 0,
1134 elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
1135 elfcpp::STV_HIDDEN
, 0, false, true);
1136 symtab
->define_in_output_data("__rel_iplt_end", NULL
,
1137 Symbol_table::PREDEFINED
,
1138 this->irelative_rel_
, 0, 0,
1139 elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
1140 elfcpp::STV_HIDDEN
, 0, true, true);
1143 return this->irelative_rel_
;
1146 // Return the PLT address to use for a global symbol.
1149 Output_data_plt_i386::address_for_global(const Symbol
* gsym
)
1151 uint64_t offset
= 0;
1152 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1153 && gsym
->can_use_relative_reloc(false))
1154 offset
= (this->count_
+ 1) * this->get_plt_entry_size();
1155 return this->address() + offset
+ gsym
->plt_offset();
1158 // Return the PLT address to use for a local symbol. These are always
1159 // IRELATIVE relocs.
1162 Output_data_plt_i386::address_for_local(const Relobj
* object
,
1165 return (this->address()
1166 + (this->count_
+ 1) * this->get_plt_entry_size()
1167 + object
->local_plt_offset(r_sym
));
1170 // The first entry in the PLT for an executable.
1172 const unsigned char Output_data_plt_i386_exec::first_plt_entry
[plt_entry_size
] =
1174 0xff, 0x35, // pushl contents of memory address
1175 0, 0, 0, 0, // replaced with address of .got + 4
1176 0xff, 0x25, // jmp indirect
1177 0, 0, 0, 0, // replaced with address of .got + 8
1178 0, 0, 0, 0 // unused
1182 Output_data_plt_i386_exec::do_fill_first_plt_entry(
1184 elfcpp::Elf_types
<32>::Elf_Addr got_address
)
1186 memcpy(pov
, first_plt_entry
, plt_entry_size
);
1187 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 4);
1188 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 8);
1191 // The first entry in the PLT for a shared object.
1193 const unsigned char Output_data_plt_i386_dyn::first_plt_entry
[plt_entry_size
] =
1195 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
1196 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
1197 0, 0, 0, 0 // unused
1201 Output_data_plt_i386_dyn::do_fill_first_plt_entry(
1203 elfcpp::Elf_types
<32>::Elf_Addr
)
1205 memcpy(pov
, first_plt_entry
, plt_entry_size
);
1208 // Subsequent entries in the PLT for an executable.
1210 const unsigned char Output_data_plt_i386_exec::plt_entry
[plt_entry_size
] =
1212 0xff, 0x25, // jmp indirect
1213 0, 0, 0, 0, // replaced with address of symbol in .got
1214 0x68, // pushl immediate
1215 0, 0, 0, 0, // replaced with offset into relocation table
1216 0xe9, // jmp relative
1217 0, 0, 0, 0 // replaced with offset to start of .plt
1221 Output_data_plt_i386_exec::do_fill_plt_entry(
1223 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
1224 unsigned int got_offset
,
1225 unsigned int plt_offset
,
1226 unsigned int plt_rel_offset
)
1228 memcpy(pov
, plt_entry
, plt_entry_size
);
1229 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
1230 got_address
+ got_offset
);
1231 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_rel_offset
);
1232 elfcpp::Swap
<32, false>::writeval(pov
+ 12, - (plt_offset
+ 12 + 4));
1236 // Subsequent entries in the PLT for a shared object.
1238 const unsigned char Output_data_plt_i386_dyn::plt_entry
[plt_entry_size
] =
1240 0xff, 0xa3, // jmp *offset(%ebx)
1241 0, 0, 0, 0, // replaced with offset of symbol in .got
1242 0x68, // pushl immediate
1243 0, 0, 0, 0, // replaced with offset into relocation table
1244 0xe9, // jmp relative
1245 0, 0, 0, 0 // replaced with offset to start of .plt
1249 Output_data_plt_i386_dyn::do_fill_plt_entry(unsigned char* pov
,
1250 elfcpp::Elf_types
<32>::Elf_Addr
,
1251 unsigned int got_offset
,
1252 unsigned int plt_offset
,
1253 unsigned int plt_rel_offset
)
1255 memcpy(pov
, plt_entry
, plt_entry_size
);
1256 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
1257 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_rel_offset
);
1258 elfcpp::Swap
<32, false>::writeval(pov
+ 12, - (plt_offset
+ 12 + 4));
1262 // The .eh_frame unwind information for the PLT.
1265 Output_data_plt_i386::plt_eh_frame_cie
[plt_eh_frame_cie_size
] =
1268 'z', // Augmentation: augmentation size included.
1269 'R', // Augmentation: FDE encoding included.
1270 '\0', // End of augmentation string.
1271 1, // Code alignment factor.
1272 0x7c, // Data alignment factor.
1273 8, // Return address column.
1274 1, // Augmentation size.
1275 (elfcpp::DW_EH_PE_pcrel
// FDE encoding.
1276 | elfcpp::DW_EH_PE_sdata4
),
1277 elfcpp::DW_CFA_def_cfa
, 4, 4, // DW_CFA_def_cfa: r4 (esp) ofs 4.
1278 elfcpp::DW_CFA_offset
+ 8, 1, // DW_CFA_offset: r8 (eip) at cfa-4.
1279 elfcpp::DW_CFA_nop
, // Align to 16 bytes.
1284 Output_data_plt_i386_standard::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
1286 0, 0, 0, 0, // Replaced with offset to .plt.
1287 0, 0, 0, 0, // Replaced with size of .plt.
1288 0, // Augmentation size.
1289 elfcpp::DW_CFA_def_cfa_offset
, 8, // DW_CFA_def_cfa_offset: 8.
1290 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
1291 elfcpp::DW_CFA_def_cfa_offset
, 12, // DW_CFA_def_cfa_offset: 12.
1292 elfcpp::DW_CFA_advance_loc
+ 10, // Advance 10 to __PLT__ + 16.
1293 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
1294 11, // Block length.
1295 elfcpp::DW_OP_breg4
, 4, // Push %esp + 4.
1296 elfcpp::DW_OP_breg8
, 0, // Push %eip.
1297 elfcpp::DW_OP_lit15
, // Push 0xf.
1298 elfcpp::DW_OP_and
, // & (%eip & 0xf).
1299 elfcpp::DW_OP_lit11
, // Push 0xb.
1300 elfcpp::DW_OP_ge
, // >= ((%eip & 0xf) >= 0xb)
1301 elfcpp::DW_OP_lit2
, // Push 2.
1302 elfcpp::DW_OP_shl
, // << (((%eip & 0xf) >= 0xb) << 2)
1303 elfcpp::DW_OP_plus
, // + ((((%eip&0xf)>=0xb)<<2)+%esp+4
1304 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
1310 // Write out the PLT. This uses the hand-coded instructions above,
1311 // and adjusts them as needed. This is all specified by the i386 ELF
1312 // Processor Supplement.
1315 Output_data_plt_i386::do_write(Output_file
* of
)
1317 const off_t offset
= this->offset();
1318 const section_size_type oview_size
=
1319 convert_to_section_size_type(this->data_size());
1320 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
1322 const off_t got_file_offset
= this->got_plt_
->offset();
1323 gold_assert(parameters
->incremental_update()
1324 || (got_file_offset
+ this->got_plt_
->data_size()
1325 == this->got_irelative_
->offset()));
1326 const section_size_type got_size
=
1327 convert_to_section_size_type(this->got_plt_
->data_size()
1328 + this->got_irelative_
->data_size());
1329 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
1332 unsigned char* pov
= oview
;
1334 elfcpp::Elf_types
<32>::Elf_Addr plt_address
= this->address();
1335 elfcpp::Elf_types
<32>::Elf_Addr got_address
= this->got_plt_
->address();
1337 this->fill_first_plt_entry(pov
, got_address
);
1338 pov
+= this->get_plt_entry_size();
1340 unsigned char* got_pov
= got_view
;
1342 // The first entry in the GOT is the address of the .dynamic section
1343 // aka the PT_DYNAMIC segment. The next two entries are reserved.
1344 // We saved space for them when we created the section in
1345 // Target_i386::got_section.
1346 Output_section
* dynamic
= this->layout_
->dynamic_section();
1347 uint32_t dynamic_addr
= dynamic
== NULL
? 0 : dynamic
->address();
1348 elfcpp::Swap
<32, false>::writeval(got_pov
, dynamic_addr
);
1350 memset(got_pov
, 0, 8);
1353 const int rel_size
= elfcpp::Elf_sizes
<32>::rel_size
;
1355 unsigned int plt_offset
= this->get_plt_entry_size();
1356 unsigned int plt_rel_offset
= 0;
1357 unsigned int got_offset
= 12;
1358 const unsigned int count
= this->count_
+ this->irelative_count_
;
1359 for (unsigned int i
= 0;
1362 pov
+= this->get_plt_entry_size(),
1364 plt_offset
+= this->get_plt_entry_size(),
1365 plt_rel_offset
+= rel_size
,
1368 // Set and adjust the PLT entry itself.
1369 unsigned int lazy_offset
= this->fill_plt_entry(pov
,
1375 // Set the entry in the GOT.
1376 elfcpp::Swap
<32, false>::writeval(got_pov
,
1377 plt_address
+ plt_offset
+ lazy_offset
);
1380 // If any STT_GNU_IFUNC symbols have PLT entries, we need to change
1381 // the GOT to point to the actual symbol value, rather than point to
1382 // the PLT entry. That will let the dynamic linker call the right
1383 // function when resolving IRELATIVE relocations.
1384 unsigned char* got_irelative_view
= got_view
+ this->got_plt_
->data_size();
1385 for (std::vector
<Global_ifunc
>::const_iterator p
=
1386 this->global_ifuncs_
.begin();
1387 p
!= this->global_ifuncs_
.end();
1390 const Sized_symbol
<32>* ssym
=
1391 static_cast<const Sized_symbol
<32>*>(p
->sym
);
1392 elfcpp::Swap
<32, false>::writeval(got_irelative_view
+ p
->got_offset
,
1396 for (std::vector
<Local_ifunc
>::const_iterator p
=
1397 this->local_ifuncs_
.begin();
1398 p
!= this->local_ifuncs_
.end();
1401 const Symbol_value
<32>* psymval
=
1402 p
->object
->local_symbol(p
->local_sym_index
);
1403 elfcpp::Swap
<32, false>::writeval(got_irelative_view
+ p
->got_offset
,
1404 psymval
->value(p
->object
, 0));
1407 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
1408 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
1410 of
->write_output_view(offset
, oview_size
, oview
);
1411 of
->write_output_view(got_file_offset
, got_size
, got_view
);
1414 // Create the PLT section.
1417 Target_i386::make_plt_section(Symbol_table
* symtab
, Layout
* layout
)
1419 if (this->plt_
== NULL
)
1421 // Create the GOT sections first.
1422 this->got_section(symtab
, layout
);
1424 const bool dyn
= parameters
->options().output_is_position_independent();
1425 this->plt_
= this->make_data_plt(layout
,
1427 this->got_irelative_
,
1430 // Add unwind information if requested.
1431 if (parameters
->options().ld_generated_unwind_info())
1432 this->plt_
->add_eh_frame(layout
);
1434 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
1436 | elfcpp::SHF_EXECINSTR
),
1437 this->plt_
, ORDER_PLT
, false);
1439 // Make the sh_info field of .rel.plt point to .plt.
1440 Output_section
* rel_plt_os
= this->plt_
->rel_plt()->output_section();
1441 rel_plt_os
->set_info_section(this->plt_
->output_section());
1445 // Create a PLT entry for a global symbol.
1448 Target_i386::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
, Symbol
* gsym
)
1450 if (gsym
->has_plt_offset())
1452 if (this->plt_
== NULL
)
1453 this->make_plt_section(symtab
, layout
);
1454 this->plt_
->add_entry(symtab
, layout
, gsym
);
1457 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1460 Target_i386::make_local_ifunc_plt_entry(Symbol_table
* symtab
, Layout
* layout
,
1461 Sized_relobj_file
<32, false>* relobj
,
1462 unsigned int local_sym_index
)
1464 if (relobj
->local_has_plt_offset(local_sym_index
))
1466 if (this->plt_
== NULL
)
1467 this->make_plt_section(symtab
, layout
);
1468 unsigned int plt_offset
= this->plt_
->add_local_ifunc_entry(symtab
, layout
,
1471 relobj
->set_local_plt_offset(local_sym_index
, plt_offset
);
1474 // Return the number of entries in the PLT.
1477 Target_i386::plt_entry_count() const
1479 if (this->plt_
== NULL
)
1481 return this->plt_
->entry_count();
1484 // Return the offset of the first non-reserved PLT entry.
1487 Target_i386::first_plt_entry_offset() const
1489 return this->plt_
->first_plt_entry_offset();
1492 // Return the size of each PLT entry.
1495 Target_i386::plt_entry_size() const
1497 return this->plt_
->get_plt_entry_size();
1500 // Get the section to use for TLS_DESC relocations.
1502 Target_i386::Reloc_section
*
1503 Target_i386::rel_tls_desc_section(Layout
* layout
) const
1505 return this->plt_section()->rel_tls_desc(layout
);
1508 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1511 Target_i386::define_tls_base_symbol(Symbol_table
* symtab
, Layout
* layout
)
1513 if (this->tls_base_symbol_defined_
)
1516 Output_segment
* tls_segment
= layout
->tls_segment();
1517 if (tls_segment
!= NULL
)
1519 bool is_exec
= parameters
->options().output_is_executable();
1520 symtab
->define_in_output_segment("_TLS_MODULE_BASE_", NULL
,
1521 Symbol_table::PREDEFINED
,
1525 elfcpp::STV_HIDDEN
, 0,
1527 ? Symbol::SEGMENT_END
1528 : Symbol::SEGMENT_START
),
1531 this->tls_base_symbol_defined_
= true;
1534 // Create a GOT entry for the TLS module index.
1537 Target_i386::got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
1538 Sized_relobj_file
<32, false>* object
)
1540 if (this->got_mod_index_offset_
== -1U)
1542 gold_assert(symtab
!= NULL
&& layout
!= NULL
&& object
!= NULL
);
1543 Reloc_section
* rel_dyn
= this->rel_dyn_section(layout
);
1544 Output_data_got
<32, false>* got
= this->got_section(symtab
, layout
);
1545 unsigned int got_offset
= got
->add_constant(0);
1546 rel_dyn
->add_local(object
, 0, elfcpp::R_386_TLS_DTPMOD32
, got
,
1548 got
->add_constant(0);
1549 this->got_mod_index_offset_
= got_offset
;
1551 return this->got_mod_index_offset_
;
1554 // Optimize the TLS relocation type based on what we know about the
1555 // symbol. IS_FINAL is true if the final address of this symbol is
1556 // known at link time.
1558 tls::Tls_optimization
1559 Target_i386::optimize_tls_reloc(bool is_final
, int r_type
)
1561 // If we are generating a shared library, then we can't do anything
1563 if (parameters
->options().shared())
1564 return tls::TLSOPT_NONE
;
1568 case elfcpp::R_386_TLS_GD
:
1569 case elfcpp::R_386_TLS_GOTDESC
:
1570 case elfcpp::R_386_TLS_DESC_CALL
:
1571 // These are General-Dynamic which permits fully general TLS
1572 // access. Since we know that we are generating an executable,
1573 // we can convert this to Initial-Exec. If we also know that
1574 // this is a local symbol, we can further switch to Local-Exec.
1576 return tls::TLSOPT_TO_LE
;
1577 return tls::TLSOPT_TO_IE
;
1579 case elfcpp::R_386_TLS_LDM
:
1580 // This is Local-Dynamic, which refers to a local symbol in the
1581 // dynamic TLS block. Since we know that we generating an
1582 // executable, we can switch to Local-Exec.
1583 return tls::TLSOPT_TO_LE
;
1585 case elfcpp::R_386_TLS_LDO_32
:
1586 // Another type of Local-Dynamic relocation.
1587 return tls::TLSOPT_TO_LE
;
1589 case elfcpp::R_386_TLS_IE
:
1590 case elfcpp::R_386_TLS_GOTIE
:
1591 case elfcpp::R_386_TLS_IE_32
:
1592 // These are Initial-Exec relocs which get the thread offset
1593 // from the GOT. If we know that we are linking against the
1594 // local symbol, we can switch to Local-Exec, which links the
1595 // thread offset into the instruction.
1597 return tls::TLSOPT_TO_LE
;
1598 return tls::TLSOPT_NONE
;
1600 case elfcpp::R_386_TLS_LE
:
1601 case elfcpp::R_386_TLS_LE_32
:
1602 // When we already have Local-Exec, there is nothing further we
1604 return tls::TLSOPT_NONE
;
1611 // Get the Reference_flags for a particular relocation.
1614 Target_i386::Scan::get_reference_flags(unsigned int r_type
)
1618 case elfcpp::R_386_NONE
:
1619 case elfcpp::R_386_GNU_VTINHERIT
:
1620 case elfcpp::R_386_GNU_VTENTRY
:
1621 case elfcpp::R_386_GOTPC
:
1622 // No symbol reference.
1625 case elfcpp::R_386_32
:
1626 case elfcpp::R_386_16
:
1627 case elfcpp::R_386_8
:
1628 return Symbol::ABSOLUTE_REF
;
1630 case elfcpp::R_386_PC32
:
1631 case elfcpp::R_386_PC16
:
1632 case elfcpp::R_386_PC8
:
1633 case elfcpp::R_386_GOTOFF
:
1634 return Symbol::RELATIVE_REF
;
1636 case elfcpp::R_386_PLT32
:
1637 return Symbol::FUNCTION_CALL
| Symbol::RELATIVE_REF
;
1639 case elfcpp::R_386_GOT32
:
1641 return Symbol::ABSOLUTE_REF
;
1643 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1644 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1645 case elfcpp::R_386_TLS_DESC_CALL
:
1646 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1647 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1648 case elfcpp::R_386_TLS_IE
: // Initial-exec
1649 case elfcpp::R_386_TLS_IE_32
:
1650 case elfcpp::R_386_TLS_GOTIE
:
1651 case elfcpp::R_386_TLS_LE
: // Local-exec
1652 case elfcpp::R_386_TLS_LE_32
:
1653 return Symbol::TLS_REF
;
1655 case elfcpp::R_386_COPY
:
1656 case elfcpp::R_386_GLOB_DAT
:
1657 case elfcpp::R_386_JUMP_SLOT
:
1658 case elfcpp::R_386_RELATIVE
:
1659 case elfcpp::R_386_IRELATIVE
:
1660 case elfcpp::R_386_TLS_TPOFF
:
1661 case elfcpp::R_386_TLS_DTPMOD32
:
1662 case elfcpp::R_386_TLS_DTPOFF32
:
1663 case elfcpp::R_386_TLS_TPOFF32
:
1664 case elfcpp::R_386_TLS_DESC
:
1665 case elfcpp::R_386_32PLT
:
1666 case elfcpp::R_386_TLS_GD_32
:
1667 case elfcpp::R_386_TLS_GD_PUSH
:
1668 case elfcpp::R_386_TLS_GD_CALL
:
1669 case elfcpp::R_386_TLS_GD_POP
:
1670 case elfcpp::R_386_TLS_LDM_32
:
1671 case elfcpp::R_386_TLS_LDM_PUSH
:
1672 case elfcpp::R_386_TLS_LDM_CALL
:
1673 case elfcpp::R_386_TLS_LDM_POP
:
1674 case elfcpp::R_386_USED_BY_INTEL_200
:
1676 // Not expected. We will give an error later.
1681 // Report an unsupported relocation against a local symbol.
1684 Target_i386::Scan::unsupported_reloc_local(Sized_relobj_file
<32, false>* object
,
1685 unsigned int r_type
)
1687 gold_error(_("%s: unsupported reloc %u against local symbol"),
1688 object
->name().c_str(), r_type
);
1691 // Return whether we need to make a PLT entry for a relocation of a
1692 // given type against a STT_GNU_IFUNC symbol.
1695 Target_i386::Scan::reloc_needs_plt_for_ifunc(
1696 Sized_relobj_file
<32, false>* object
,
1697 unsigned int r_type
)
1699 int flags
= Scan::get_reference_flags(r_type
);
1700 if (flags
& Symbol::TLS_REF
)
1701 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
1702 object
->name().c_str(), r_type
);
1706 // Scan a relocation for a local symbol.
1709 Target_i386::Scan::local(Symbol_table
* symtab
,
1711 Target_i386
* target
,
1712 Sized_relobj_file
<32, false>* object
,
1713 unsigned int data_shndx
,
1714 Output_section
* output_section
,
1715 const elfcpp::Rel
<32, false>& reloc
,
1716 unsigned int r_type
,
1717 const elfcpp::Sym
<32, false>& lsym
,
1723 // A local STT_GNU_IFUNC symbol may require a PLT entry.
1724 if (lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
1725 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
1727 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1728 target
->make_local_ifunc_plt_entry(symtab
, layout
, object
, r_sym
);
1733 case elfcpp::R_386_NONE
:
1734 case elfcpp::R_386_GNU_VTINHERIT
:
1735 case elfcpp::R_386_GNU_VTENTRY
:
1738 case elfcpp::R_386_32
:
1739 // If building a shared library (or a position-independent
1740 // executable), we need to create a dynamic relocation for
1741 // this location. The relocation applied at link time will
1742 // apply the link-time value, so we flag the location with
1743 // an R_386_RELATIVE relocation so the dynamic loader can
1744 // relocate it easily.
1745 if (parameters
->options().output_is_position_independent())
1747 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1748 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1749 rel_dyn
->add_local_relative(object
, r_sym
, elfcpp::R_386_RELATIVE
,
1750 output_section
, data_shndx
,
1751 reloc
.get_r_offset());
1755 case elfcpp::R_386_16
:
1756 case elfcpp::R_386_8
:
1757 // If building a shared library (or a position-independent
1758 // executable), we need to create a dynamic relocation for
1759 // this location. Because the addend needs to remain in the
1760 // data section, we need to be careful not to apply this
1761 // relocation statically.
1762 if (parameters
->options().output_is_position_independent())
1764 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1765 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1766 if (lsym
.get_st_type() != elfcpp::STT_SECTION
)
1767 rel_dyn
->add_local(object
, r_sym
, r_type
, output_section
,
1768 data_shndx
, reloc
.get_r_offset());
1771 gold_assert(lsym
.get_st_value() == 0);
1772 unsigned int shndx
= lsym
.get_st_shndx();
1774 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
,
1777 object
->error(_("section symbol %u has bad shndx %u"),
1780 rel_dyn
->add_local_section(object
, shndx
,
1781 r_type
, output_section
,
1782 data_shndx
, reloc
.get_r_offset());
1787 case elfcpp::R_386_PC32
:
1788 case elfcpp::R_386_PC16
:
1789 case elfcpp::R_386_PC8
:
1792 case elfcpp::R_386_PLT32
:
1793 // Since we know this is a local symbol, we can handle this as a
1797 case elfcpp::R_386_GOTOFF
:
1798 case elfcpp::R_386_GOTPC
:
1799 // We need a GOT section.
1800 target
->got_section(symtab
, layout
);
1803 case elfcpp::R_386_GOT32
:
1805 // The symbol requires a GOT entry.
1806 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
1807 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1809 // For a STT_GNU_IFUNC symbol we want the PLT offset. That
1810 // lets function pointers compare correctly with shared
1811 // libraries. Otherwise we would need an IRELATIVE reloc.
1813 if (lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
)
1814 is_new
= got
->add_local_plt(object
, r_sym
, GOT_TYPE_STANDARD
);
1816 is_new
= got
->add_local(object
, r_sym
, GOT_TYPE_STANDARD
);
1819 // If we are generating a shared object, we need to add a
1820 // dynamic RELATIVE relocation for this symbol's GOT entry.
1821 if (parameters
->options().output_is_position_independent())
1823 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1824 unsigned int got_offset
=
1825 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
);
1826 rel_dyn
->add_local_relative(object
, r_sym
,
1827 elfcpp::R_386_RELATIVE
,
1834 // These are relocations which should only be seen by the
1835 // dynamic linker, and should never be seen here.
1836 case elfcpp::R_386_COPY
:
1837 case elfcpp::R_386_GLOB_DAT
:
1838 case elfcpp::R_386_JUMP_SLOT
:
1839 case elfcpp::R_386_RELATIVE
:
1840 case elfcpp::R_386_IRELATIVE
:
1841 case elfcpp::R_386_TLS_TPOFF
:
1842 case elfcpp::R_386_TLS_DTPMOD32
:
1843 case elfcpp::R_386_TLS_DTPOFF32
:
1844 case elfcpp::R_386_TLS_TPOFF32
:
1845 case elfcpp::R_386_TLS_DESC
:
1846 gold_error(_("%s: unexpected reloc %u in object file"),
1847 object
->name().c_str(), r_type
);
1850 // These are initial TLS relocs, which are expected when
1852 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1853 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1854 case elfcpp::R_386_TLS_DESC_CALL
:
1855 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1856 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1857 case elfcpp::R_386_TLS_IE
: // Initial-exec
1858 case elfcpp::R_386_TLS_IE_32
:
1859 case elfcpp::R_386_TLS_GOTIE
:
1860 case elfcpp::R_386_TLS_LE
: // Local-exec
1861 case elfcpp::R_386_TLS_LE_32
:
1863 bool output_is_shared
= parameters
->options().shared();
1864 const tls::Tls_optimization optimized_type
1865 = Target_i386::optimize_tls_reloc(!output_is_shared
, r_type
);
1868 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1869 if (optimized_type
== tls::TLSOPT_NONE
)
1871 // Create a pair of GOT entries for the module index and
1872 // dtv-relative offset.
1873 Output_data_got
<32, false>* got
1874 = target
->got_section(symtab
, layout
);
1875 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1876 unsigned int shndx
= lsym
.get_st_shndx();
1878 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
1880 object
->error(_("local symbol %u has bad shndx %u"),
1883 got
->add_local_pair_with_rel(object
, r_sym
, shndx
,
1885 target
->rel_dyn_section(layout
),
1886 elfcpp::R_386_TLS_DTPMOD32
);
1888 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1889 unsupported_reloc_local(object
, r_type
);
1892 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva)
1893 target
->define_tls_base_symbol(symtab
, layout
);
1894 if (optimized_type
== tls::TLSOPT_NONE
)
1896 // Create a double GOT entry with an R_386_TLS_DESC
1897 // reloc. The R_386_TLS_DESC reloc is resolved
1898 // lazily, so the GOT entry needs to be in an area in
1899 // .got.plt, not .got. Call got_section to make sure
1900 // the section has been created.
1901 target
->got_section(symtab
, layout
);
1902 Output_data_got
<32, false>* got
= target
->got_tlsdesc_section();
1903 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1904 if (!object
->local_has_got_offset(r_sym
, GOT_TYPE_TLS_DESC
))
1906 unsigned int got_offset
= got
->add_constant(0);
1907 // The local symbol value is stored in the second
1909 got
->add_local(object
, r_sym
, GOT_TYPE_TLS_DESC
);
1910 // That set the GOT offset of the local symbol to
1911 // point to the second entry, but we want it to
1912 // point to the first.
1913 object
->set_local_got_offset(r_sym
, GOT_TYPE_TLS_DESC
,
1915 Reloc_section
* rt
= target
->rel_tls_desc_section(layout
);
1916 rt
->add_absolute(elfcpp::R_386_TLS_DESC
, got
, got_offset
);
1919 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1920 unsupported_reloc_local(object
, r_type
);
1923 case elfcpp::R_386_TLS_DESC_CALL
:
1926 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1927 if (optimized_type
== tls::TLSOPT_NONE
)
1929 // Create a GOT entry for the module index.
1930 target
->got_mod_index_entry(symtab
, layout
, object
);
1932 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1933 unsupported_reloc_local(object
, r_type
);
1936 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1939 case elfcpp::R_386_TLS_IE
: // Initial-exec
1940 case elfcpp::R_386_TLS_IE_32
:
1941 case elfcpp::R_386_TLS_GOTIE
:
1942 layout
->set_has_static_tls();
1943 if (optimized_type
== tls::TLSOPT_NONE
)
1945 // For the R_386_TLS_IE relocation, we need to create a
1946 // dynamic relocation when building a shared library.
1947 if (r_type
== elfcpp::R_386_TLS_IE
1948 && parameters
->options().shared())
1950 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1952 = elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1953 rel_dyn
->add_local_relative(object
, r_sym
,
1954 elfcpp::R_386_RELATIVE
,
1955 output_section
, data_shndx
,
1956 reloc
.get_r_offset());
1958 // Create a GOT entry for the tp-relative offset.
1959 Output_data_got
<32, false>* got
1960 = target
->got_section(symtab
, layout
);
1961 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1962 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1963 ? elfcpp::R_386_TLS_TPOFF32
1964 : elfcpp::R_386_TLS_TPOFF
);
1965 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1966 ? GOT_TYPE_TLS_OFFSET
1967 : GOT_TYPE_TLS_NOFFSET
);
1968 got
->add_local_with_rel(object
, r_sym
, got_type
,
1969 target
->rel_dyn_section(layout
),
1972 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1973 unsupported_reloc_local(object
, r_type
);
1976 case elfcpp::R_386_TLS_LE
: // Local-exec
1977 case elfcpp::R_386_TLS_LE_32
:
1978 layout
->set_has_static_tls();
1979 if (output_is_shared
)
1981 // We need to create a dynamic relocation.
1982 gold_assert(lsym
.get_st_type() != elfcpp::STT_SECTION
);
1983 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1984 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
1985 ? elfcpp::R_386_TLS_TPOFF32
1986 : elfcpp::R_386_TLS_TPOFF
);
1987 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1988 rel_dyn
->add_local(object
, r_sym
, dyn_r_type
, output_section
,
1989 data_shndx
, reloc
.get_r_offset());
1999 case elfcpp::R_386_32PLT
:
2000 case elfcpp::R_386_TLS_GD_32
:
2001 case elfcpp::R_386_TLS_GD_PUSH
:
2002 case elfcpp::R_386_TLS_GD_CALL
:
2003 case elfcpp::R_386_TLS_GD_POP
:
2004 case elfcpp::R_386_TLS_LDM_32
:
2005 case elfcpp::R_386_TLS_LDM_PUSH
:
2006 case elfcpp::R_386_TLS_LDM_CALL
:
2007 case elfcpp::R_386_TLS_LDM_POP
:
2008 case elfcpp::R_386_USED_BY_INTEL_200
:
2010 unsupported_reloc_local(object
, r_type
);
2015 // Report an unsupported relocation against a global symbol.
2018 Target_i386::Scan::unsupported_reloc_global(
2019 Sized_relobj_file
<32, false>* object
,
2020 unsigned int r_type
,
2023 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
2024 object
->name().c_str(), r_type
, gsym
->demangled_name().c_str());
2028 Target_i386::Scan::possible_function_pointer_reloc(unsigned int r_type
)
2032 case elfcpp::R_386_32
:
2033 case elfcpp::R_386_16
:
2034 case elfcpp::R_386_8
:
2035 case elfcpp::R_386_GOTOFF
:
2036 case elfcpp::R_386_GOT32
:
2047 Target_i386::Scan::local_reloc_may_be_function_pointer(
2051 Sized_relobj_file
<32, false>* ,
2054 const elfcpp::Rel
<32, false>& ,
2055 unsigned int r_type
,
2056 const elfcpp::Sym
<32, false>&)
2058 return possible_function_pointer_reloc(r_type
);
2062 Target_i386::Scan::global_reloc_may_be_function_pointer(
2066 Sized_relobj_file
<32, false>* ,
2069 const elfcpp::Rel
<32, false>& ,
2070 unsigned int r_type
,
2073 return possible_function_pointer_reloc(r_type
);
2076 // Scan a relocation for a global symbol.
2079 Target_i386::Scan::global(Symbol_table
* symtab
,
2081 Target_i386
* target
,
2082 Sized_relobj_file
<32, false>* object
,
2083 unsigned int data_shndx
,
2084 Output_section
* output_section
,
2085 const elfcpp::Rel
<32, false>& reloc
,
2086 unsigned int r_type
,
2089 // A STT_GNU_IFUNC symbol may require a PLT entry.
2090 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
2091 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
2092 target
->make_plt_entry(symtab
, layout
, gsym
);
2096 case elfcpp::R_386_NONE
:
2097 case elfcpp::R_386_GNU_VTINHERIT
:
2098 case elfcpp::R_386_GNU_VTENTRY
:
2101 case elfcpp::R_386_32
:
2102 case elfcpp::R_386_16
:
2103 case elfcpp::R_386_8
:
2105 // Make a PLT entry if necessary.
2106 if (gsym
->needs_plt_entry())
2108 target
->make_plt_entry(symtab
, layout
, gsym
);
2109 // Since this is not a PC-relative relocation, we may be
2110 // taking the address of a function. In that case we need to
2111 // set the entry in the dynamic symbol table to the address of
2113 if (gsym
->is_from_dynobj() && !parameters
->options().shared())
2114 gsym
->set_needs_dynsym_value();
2116 // Make a dynamic relocation if necessary.
2117 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
2119 if (gsym
->may_need_copy_reloc())
2121 target
->copy_reloc(symtab
, layout
, object
,
2122 data_shndx
, output_section
, gsym
, reloc
);
2124 else if (r_type
== elfcpp::R_386_32
2125 && gsym
->type() == elfcpp::STT_GNU_IFUNC
2126 && gsym
->can_use_relative_reloc(false)
2127 && !gsym
->is_from_dynobj()
2128 && !gsym
->is_undefined()
2129 && !gsym
->is_preemptible())
2131 // Use an IRELATIVE reloc for a locally defined
2132 // STT_GNU_IFUNC symbol. This makes a function
2133 // address in a PIE executable match the address in a
2134 // shared library that it links against.
2135 Reloc_section
* rel_dyn
= target
->rel_irelative_section(layout
);
2136 rel_dyn
->add_symbolless_global_addend(gsym
,
2137 elfcpp::R_386_IRELATIVE
,
2140 reloc
.get_r_offset());
2142 else if (r_type
== elfcpp::R_386_32
2143 && gsym
->can_use_relative_reloc(false))
2145 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2146 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
2147 output_section
, object
,
2148 data_shndx
, reloc
.get_r_offset());
2152 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2153 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
2154 data_shndx
, reloc
.get_r_offset());
2160 case elfcpp::R_386_PC32
:
2161 case elfcpp::R_386_PC16
:
2162 case elfcpp::R_386_PC8
:
2164 // Make a PLT entry if necessary.
2165 if (gsym
->needs_plt_entry())
2167 // These relocations are used for function calls only in
2168 // non-PIC code. For a 32-bit relocation in a shared library,
2169 // we'll need a text relocation anyway, so we can skip the
2170 // PLT entry and let the dynamic linker bind the call directly
2171 // to the target. For smaller relocations, we should use a
2172 // PLT entry to ensure that the call can reach.
2173 if (!parameters
->options().shared()
2174 || r_type
!= elfcpp::R_386_PC32
)
2175 target
->make_plt_entry(symtab
, layout
, gsym
);
2177 // Make a dynamic relocation if necessary.
2178 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
2180 if (gsym
->may_need_copy_reloc())
2182 target
->copy_reloc(symtab
, layout
, object
,
2183 data_shndx
, output_section
, gsym
, reloc
);
2187 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2188 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
2189 data_shndx
, reloc
.get_r_offset());
2195 case elfcpp::R_386_GOT32
:
2197 // The symbol requires a GOT entry.
2198 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
2199 if (gsym
->final_value_is_known())
2201 // For a STT_GNU_IFUNC symbol we want the PLT address.
2202 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
)
2203 got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
2205 got
->add_global(gsym
, GOT_TYPE_STANDARD
);
2209 // If this symbol is not fully resolved, we need to add a
2210 // GOT entry with a dynamic relocation.
2211 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2213 // Use a GLOB_DAT rather than a RELATIVE reloc if:
2215 // 1) The symbol may be defined in some other module.
2217 // 2) We are building a shared library and this is a
2218 // protected symbol; using GLOB_DAT means that the dynamic
2219 // linker can use the address of the PLT in the main
2220 // executable when appropriate so that function address
2221 // comparisons work.
2223 // 3) This is a STT_GNU_IFUNC symbol in position dependent
2224 // code, again so that function address comparisons work.
2225 if (gsym
->is_from_dynobj()
2226 || gsym
->is_undefined()
2227 || gsym
->is_preemptible()
2228 || (gsym
->visibility() == elfcpp::STV_PROTECTED
2229 && parameters
->options().shared())
2230 || (gsym
->type() == elfcpp::STT_GNU_IFUNC
2231 && parameters
->options().output_is_position_independent()))
2232 got
->add_global_with_rel(gsym
, GOT_TYPE_STANDARD
,
2233 rel_dyn
, elfcpp::R_386_GLOB_DAT
);
2236 // For a STT_GNU_IFUNC symbol we want to write the PLT
2237 // offset into the GOT, so that function pointer
2238 // comparisons work correctly.
2240 if (gsym
->type() != elfcpp::STT_GNU_IFUNC
)
2241 is_new
= got
->add_global(gsym
, GOT_TYPE_STANDARD
);
2244 is_new
= got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
2245 // Tell the dynamic linker to use the PLT address
2246 // when resolving relocations.
2247 if (gsym
->is_from_dynobj()
2248 && !parameters
->options().shared())
2249 gsym
->set_needs_dynsym_value();
2253 unsigned int got_off
= gsym
->got_offset(GOT_TYPE_STANDARD
);
2254 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
2262 case elfcpp::R_386_PLT32
:
2263 // If the symbol is fully resolved, this is just a PC32 reloc.
2264 // Otherwise we need a PLT entry.
2265 if (gsym
->final_value_is_known())
2267 // If building a shared library, we can also skip the PLT entry
2268 // if the symbol is defined in the output file and is protected
2270 if (gsym
->is_defined()
2271 && !gsym
->is_from_dynobj()
2272 && !gsym
->is_preemptible())
2274 target
->make_plt_entry(symtab
, layout
, gsym
);
2277 case elfcpp::R_386_GOTOFF
:
2278 case elfcpp::R_386_GOTPC
:
2279 // We need a GOT section.
2280 target
->got_section(symtab
, layout
);
2283 // These are relocations which should only be seen by the
2284 // dynamic linker, and should never be seen here.
2285 case elfcpp::R_386_COPY
:
2286 case elfcpp::R_386_GLOB_DAT
:
2287 case elfcpp::R_386_JUMP_SLOT
:
2288 case elfcpp::R_386_RELATIVE
:
2289 case elfcpp::R_386_IRELATIVE
:
2290 case elfcpp::R_386_TLS_TPOFF
:
2291 case elfcpp::R_386_TLS_DTPMOD32
:
2292 case elfcpp::R_386_TLS_DTPOFF32
:
2293 case elfcpp::R_386_TLS_TPOFF32
:
2294 case elfcpp::R_386_TLS_DESC
:
2295 gold_error(_("%s: unexpected reloc %u in object file"),
2296 object
->name().c_str(), r_type
);
2299 // These are initial tls relocs, which are expected when
2301 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2302 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2303 case elfcpp::R_386_TLS_DESC_CALL
:
2304 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2305 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2306 case elfcpp::R_386_TLS_IE
: // Initial-exec
2307 case elfcpp::R_386_TLS_IE_32
:
2308 case elfcpp::R_386_TLS_GOTIE
:
2309 case elfcpp::R_386_TLS_LE
: // Local-exec
2310 case elfcpp::R_386_TLS_LE_32
:
2312 const bool is_final
= gsym
->final_value_is_known();
2313 const tls::Tls_optimization optimized_type
2314 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
2317 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2318 if (optimized_type
== tls::TLSOPT_NONE
)
2320 // Create a pair of GOT entries for the module index and
2321 // dtv-relative offset.
2322 Output_data_got
<32, false>* got
2323 = target
->got_section(symtab
, layout
);
2324 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_PAIR
,
2325 target
->rel_dyn_section(layout
),
2326 elfcpp::R_386_TLS_DTPMOD32
,
2327 elfcpp::R_386_TLS_DTPOFF32
);
2329 else if (optimized_type
== tls::TLSOPT_TO_IE
)
2331 // Create a GOT entry for the tp-relative offset.
2332 Output_data_got
<32, false>* got
2333 = target
->got_section(symtab
, layout
);
2334 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
2335 target
->rel_dyn_section(layout
),
2336 elfcpp::R_386_TLS_TPOFF
);
2338 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2339 unsupported_reloc_global(object
, r_type
, gsym
);
2342 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (~oliva url)
2343 target
->define_tls_base_symbol(symtab
, layout
);
2344 if (optimized_type
== tls::TLSOPT_NONE
)
2346 // Create a double GOT entry with an R_386_TLS_DESC
2347 // reloc. The R_386_TLS_DESC reloc is resolved
2348 // lazily, so the GOT entry needs to be in an area in
2349 // .got.plt, not .got. Call got_section to make sure
2350 // the section has been created.
2351 target
->got_section(symtab
, layout
);
2352 Output_data_got
<32, false>* got
= target
->got_tlsdesc_section();
2353 Reloc_section
* rt
= target
->rel_tls_desc_section(layout
);
2354 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_DESC
, rt
,
2355 elfcpp::R_386_TLS_DESC
, 0);
2357 else if (optimized_type
== tls::TLSOPT_TO_IE
)
2359 // Create a GOT entry for the tp-relative offset.
2360 Output_data_got
<32, false>* got
2361 = target
->got_section(symtab
, layout
);
2362 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
2363 target
->rel_dyn_section(layout
),
2364 elfcpp::R_386_TLS_TPOFF
);
2366 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2367 unsupported_reloc_global(object
, r_type
, gsym
);
2370 case elfcpp::R_386_TLS_DESC_CALL
:
2373 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2374 if (optimized_type
== tls::TLSOPT_NONE
)
2376 // Create a GOT entry for the module index.
2377 target
->got_mod_index_entry(symtab
, layout
, object
);
2379 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2380 unsupported_reloc_global(object
, r_type
, gsym
);
2383 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2386 case elfcpp::R_386_TLS_IE
: // Initial-exec
2387 case elfcpp::R_386_TLS_IE_32
:
2388 case elfcpp::R_386_TLS_GOTIE
:
2389 layout
->set_has_static_tls();
2390 if (optimized_type
== tls::TLSOPT_NONE
)
2392 // For the R_386_TLS_IE relocation, we need to create a
2393 // dynamic relocation when building a shared library.
2394 if (r_type
== elfcpp::R_386_TLS_IE
2395 && parameters
->options().shared())
2397 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2398 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
2399 output_section
, object
,
2401 reloc
.get_r_offset());
2403 // Create a GOT entry for the tp-relative offset.
2404 Output_data_got
<32, false>* got
2405 = target
->got_section(symtab
, layout
);
2406 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2407 ? elfcpp::R_386_TLS_TPOFF32
2408 : elfcpp::R_386_TLS_TPOFF
);
2409 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2410 ? GOT_TYPE_TLS_OFFSET
2411 : GOT_TYPE_TLS_NOFFSET
);
2412 got
->add_global_with_rel(gsym
, got_type
,
2413 target
->rel_dyn_section(layout
),
2416 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2417 unsupported_reloc_global(object
, r_type
, gsym
);
2420 case elfcpp::R_386_TLS_LE
: // Local-exec
2421 case elfcpp::R_386_TLS_LE_32
:
2422 layout
->set_has_static_tls();
2423 if (parameters
->options().shared())
2425 // We need to create a dynamic relocation.
2426 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
2427 ? elfcpp::R_386_TLS_TPOFF32
2428 : elfcpp::R_386_TLS_TPOFF
);
2429 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2430 rel_dyn
->add_global(gsym
, dyn_r_type
, output_section
, object
,
2431 data_shndx
, reloc
.get_r_offset());
2441 case elfcpp::R_386_32PLT
:
2442 case elfcpp::R_386_TLS_GD_32
:
2443 case elfcpp::R_386_TLS_GD_PUSH
:
2444 case elfcpp::R_386_TLS_GD_CALL
:
2445 case elfcpp::R_386_TLS_GD_POP
:
2446 case elfcpp::R_386_TLS_LDM_32
:
2447 case elfcpp::R_386_TLS_LDM_PUSH
:
2448 case elfcpp::R_386_TLS_LDM_CALL
:
2449 case elfcpp::R_386_TLS_LDM_POP
:
2450 case elfcpp::R_386_USED_BY_INTEL_200
:
2452 unsupported_reloc_global(object
, r_type
, gsym
);
2457 // Process relocations for gc.
2460 Target_i386::gc_process_relocs(Symbol_table
* symtab
,
2462 Sized_relobj_file
<32, false>* object
,
2463 unsigned int data_shndx
,
2465 const unsigned char* prelocs
,
2467 Output_section
* output_section
,
2468 bool needs_special_offset_handling
,
2469 size_t local_symbol_count
,
2470 const unsigned char* plocal_symbols
)
2472 gold::gc_process_relocs
<32, false, Target_i386
, elfcpp::SHT_REL
,
2474 Target_i386::Relocatable_size_for_reloc
>(
2483 needs_special_offset_handling
,
2488 // Scan relocations for a section.
2491 Target_i386::scan_relocs(Symbol_table
* symtab
,
2493 Sized_relobj_file
<32, false>* object
,
2494 unsigned int data_shndx
,
2495 unsigned int sh_type
,
2496 const unsigned char* prelocs
,
2498 Output_section
* output_section
,
2499 bool needs_special_offset_handling
,
2500 size_t local_symbol_count
,
2501 const unsigned char* plocal_symbols
)
2503 if (sh_type
== elfcpp::SHT_RELA
)
2505 gold_error(_("%s: unsupported RELA reloc section"),
2506 object
->name().c_str());
2510 gold::scan_relocs
<32, false, Target_i386
, elfcpp::SHT_REL
,
2520 needs_special_offset_handling
,
2525 // Finalize the sections.
2528 Target_i386::do_finalize_sections(
2530 const Input_objects
*,
2531 Symbol_table
* symtab
)
2533 const Reloc_section
* rel_plt
= (this->plt_
== NULL
2535 : this->plt_
->rel_plt());
2536 layout
->add_target_dynamic_tags(true, this->got_plt_
, rel_plt
,
2537 this->rel_dyn_
, true, false);
2539 // Emit any relocs we saved in an attempt to avoid generating COPY
2541 if (this->copy_relocs_
.any_saved_relocs())
2542 this->copy_relocs_
.emit(this->rel_dyn_section(layout
));
2544 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
2545 // the .got.plt section.
2546 Symbol
* sym
= this->global_offset_table_
;
2549 uint32_t data_size
= this->got_plt_
->current_data_size();
2550 symtab
->get_sized_symbol
<32>(sym
)->set_symsize(data_size
);
2553 if (parameters
->doing_static_link()
2554 && (this->plt_
== NULL
|| !this->plt_
->has_irelative_section()))
2556 // If linking statically, make sure that the __rel_iplt symbols
2557 // were defined if necessary, even if we didn't create a PLT.
2558 static const Define_symbol_in_segment syms
[] =
2561 "__rel_iplt_start", // name
2562 elfcpp::PT_LOAD
, // segment_type
2563 elfcpp::PF_W
, // segment_flags_set
2564 elfcpp::PF(0), // segment_flags_clear
2567 elfcpp::STT_NOTYPE
, // type
2568 elfcpp::STB_GLOBAL
, // binding
2569 elfcpp::STV_HIDDEN
, // visibility
2571 Symbol::SEGMENT_START
, // offset_from_base
2575 "__rel_iplt_end", // name
2576 elfcpp::PT_LOAD
, // segment_type
2577 elfcpp::PF_W
, // segment_flags_set
2578 elfcpp::PF(0), // segment_flags_clear
2581 elfcpp::STT_NOTYPE
, // type
2582 elfcpp::STB_GLOBAL
, // binding
2583 elfcpp::STV_HIDDEN
, // visibility
2585 Symbol::SEGMENT_START
, // offset_from_base
2590 symtab
->define_symbols(layout
, 2, syms
,
2591 layout
->script_options()->saw_sections_clause());
2595 // Return whether a direct absolute static relocation needs to be applied.
2596 // In cases where Scan::local() or Scan::global() has created
2597 // a dynamic relocation other than R_386_RELATIVE, the addend
2598 // of the relocation is carried in the data, and we must not
2599 // apply the static relocation.
2602 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
2603 unsigned int r_type
,
2605 Output_section
* output_section
)
2607 // If the output section is not allocated, then we didn't call
2608 // scan_relocs, we didn't create a dynamic reloc, and we must apply
2610 if ((output_section
->flags() & elfcpp::SHF_ALLOC
) == 0)
2613 int ref_flags
= Scan::get_reference_flags(r_type
);
2615 // For local symbols, we will have created a non-RELATIVE dynamic
2616 // relocation only if (a) the output is position independent,
2617 // (b) the relocation is absolute (not pc- or segment-relative), and
2618 // (c) the relocation is not 32 bits wide.
2620 return !(parameters
->options().output_is_position_independent()
2621 && (ref_flags
& Symbol::ABSOLUTE_REF
)
2624 // For global symbols, we use the same helper routines used in the
2625 // scan pass. If we did not create a dynamic relocation, or if we
2626 // created a RELATIVE dynamic relocation, we should apply the static
2628 bool has_dyn
= gsym
->needs_dynamic_reloc(ref_flags
);
2629 bool is_rel
= (ref_flags
& Symbol::ABSOLUTE_REF
)
2630 && gsym
->can_use_relative_reloc(ref_flags
2631 & Symbol::FUNCTION_CALL
);
2632 return !has_dyn
|| is_rel
;
2635 // Perform a relocation.
2638 Target_i386::Relocate::relocate(const Relocate_info
<32, false>* relinfo
,
2639 Target_i386
* target
,
2640 Output_section
* output_section
,
2642 const elfcpp::Rel
<32, false>& rel
,
2643 unsigned int r_type
,
2644 const Sized_symbol
<32>* gsym
,
2645 const Symbol_value
<32>* psymval
,
2646 unsigned char* view
,
2647 elfcpp::Elf_types
<32>::Elf_Addr address
,
2648 section_size_type view_size
)
2650 if (this->skip_call_tls_get_addr_
)
2652 if ((r_type
!= elfcpp::R_386_PLT32
2653 && r_type
!= elfcpp::R_386_PC32
)
2655 || strcmp(gsym
->name(), "___tls_get_addr") != 0)
2656 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2657 _("missing expected TLS relocation"));
2660 this->skip_call_tls_get_addr_
= false;
2668 const Sized_relobj_file
<32, false>* object
= relinfo
->object
;
2670 // Pick the value to use for symbols defined in shared objects.
2671 Symbol_value
<32> symval
;
2673 && gsym
->type() == elfcpp::STT_GNU_IFUNC
2674 && r_type
== elfcpp::R_386_32
2675 && gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
))
2676 && gsym
->can_use_relative_reloc(false)
2677 && !gsym
->is_from_dynobj()
2678 && !gsym
->is_undefined()
2679 && !gsym
->is_preemptible())
2681 // In this case we are generating a R_386_IRELATIVE reloc. We
2682 // want to use the real value of the symbol, not the PLT offset.
2684 else if (gsym
!= NULL
2685 && gsym
->use_plt_offset(Scan::get_reference_flags(r_type
)))
2687 symval
.set_output_value(target
->plt_address_for_global(gsym
));
2690 else if (gsym
== NULL
&& psymval
->is_ifunc_symbol())
2692 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2693 if (object
->local_has_plt_offset(r_sym
))
2695 symval
.set_output_value(target
->plt_address_for_local(object
, r_sym
));
2700 // Get the GOT offset if needed.
2701 // The GOT pointer points to the end of the GOT section.
2702 // We need to subtract the size of the GOT section to get
2703 // the actual offset to use in the relocation.
2704 bool have_got_offset
= false;
2705 unsigned int got_offset
= 0;
2708 case elfcpp::R_386_GOT32
:
2711 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
2712 got_offset
= (gsym
->got_offset(GOT_TYPE_STANDARD
)
2713 - target
->got_size());
2717 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2718 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
2719 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
2720 - target
->got_size());
2722 have_got_offset
= true;
2731 case elfcpp::R_386_NONE
:
2732 case elfcpp::R_386_GNU_VTINHERIT
:
2733 case elfcpp::R_386_GNU_VTENTRY
:
2736 case elfcpp::R_386_32
:
2737 if (should_apply_static_reloc(gsym
, r_type
, true, output_section
))
2738 Relocate_functions
<32, false>::rel32(view
, object
, psymval
);
2741 case elfcpp::R_386_PC32
:
2742 if (should_apply_static_reloc(gsym
, r_type
, true, output_section
))
2743 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
2746 case elfcpp::R_386_16
:
2747 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2748 Relocate_functions
<32, false>::rel16(view
, object
, psymval
);
2751 case elfcpp::R_386_PC16
:
2752 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2753 Relocate_functions
<32, false>::pcrel16(view
, object
, psymval
, address
);
2756 case elfcpp::R_386_8
:
2757 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2758 Relocate_functions
<32, false>::rel8(view
, object
, psymval
);
2761 case elfcpp::R_386_PC8
:
2762 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2763 Relocate_functions
<32, false>::pcrel8(view
, object
, psymval
, address
);
2766 case elfcpp::R_386_PLT32
:
2767 gold_assert(gsym
== NULL
2768 || gsym
->has_plt_offset()
2769 || gsym
->final_value_is_known()
2770 || (gsym
->is_defined()
2771 && !gsym
->is_from_dynobj()
2772 && !gsym
->is_preemptible()));
2773 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
2776 case elfcpp::R_386_GOT32
:
2777 gold_assert(have_got_offset
);
2778 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2781 case elfcpp::R_386_GOTOFF
:
2783 elfcpp::Elf_types
<32>::Elf_Addr value
;
2784 value
= (psymval
->value(object
, 0)
2785 - target
->got_plt_section()->address());
2786 Relocate_functions
<32, false>::rel32(view
, value
);
2790 case elfcpp::R_386_GOTPC
:
2792 elfcpp::Elf_types
<32>::Elf_Addr value
;
2793 value
= target
->got_plt_section()->address();
2794 Relocate_functions
<32, false>::pcrel32(view
, value
, address
);
2798 case elfcpp::R_386_COPY
:
2799 case elfcpp::R_386_GLOB_DAT
:
2800 case elfcpp::R_386_JUMP_SLOT
:
2801 case elfcpp::R_386_RELATIVE
:
2802 case elfcpp::R_386_IRELATIVE
:
2803 // These are outstanding tls relocs, which are unexpected when
2805 case elfcpp::R_386_TLS_TPOFF
:
2806 case elfcpp::R_386_TLS_DTPMOD32
:
2807 case elfcpp::R_386_TLS_DTPOFF32
:
2808 case elfcpp::R_386_TLS_TPOFF32
:
2809 case elfcpp::R_386_TLS_DESC
:
2810 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2811 _("unexpected reloc %u in object file"),
2815 // These are initial tls relocs, which are expected when
2817 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2818 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2819 case elfcpp::R_386_TLS_DESC_CALL
:
2820 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2821 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2822 case elfcpp::R_386_TLS_IE
: // Initial-exec
2823 case elfcpp::R_386_TLS_IE_32
:
2824 case elfcpp::R_386_TLS_GOTIE
:
2825 case elfcpp::R_386_TLS_LE
: // Local-exec
2826 case elfcpp::R_386_TLS_LE_32
:
2827 this->relocate_tls(relinfo
, target
, relnum
, rel
, r_type
, gsym
, psymval
,
2828 view
, address
, view_size
);
2831 case elfcpp::R_386_32PLT
:
2832 case elfcpp::R_386_TLS_GD_32
:
2833 case elfcpp::R_386_TLS_GD_PUSH
:
2834 case elfcpp::R_386_TLS_GD_CALL
:
2835 case elfcpp::R_386_TLS_GD_POP
:
2836 case elfcpp::R_386_TLS_LDM_32
:
2837 case elfcpp::R_386_TLS_LDM_PUSH
:
2838 case elfcpp::R_386_TLS_LDM_CALL
:
2839 case elfcpp::R_386_TLS_LDM_POP
:
2840 case elfcpp::R_386_USED_BY_INTEL_200
:
2842 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2843 _("unsupported reloc %u"),
2851 // Perform a TLS relocation.
2854 Target_i386::Relocate::relocate_tls(const Relocate_info
<32, false>* relinfo
,
2855 Target_i386
* target
,
2857 const elfcpp::Rel
<32, false>& rel
,
2858 unsigned int r_type
,
2859 const Sized_symbol
<32>* gsym
,
2860 const Symbol_value
<32>* psymval
,
2861 unsigned char* view
,
2862 elfcpp::Elf_types
<32>::Elf_Addr
,
2863 section_size_type view_size
)
2865 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
2867 const Sized_relobj_file
<32, false>* object
= relinfo
->object
;
2869 elfcpp::Elf_types
<32>::Elf_Addr value
= psymval
->value(object
, 0);
2871 const bool is_final
= (gsym
== NULL
2872 ? !parameters
->options().shared()
2873 : gsym
->final_value_is_known());
2874 const tls::Tls_optimization optimized_type
2875 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
2878 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2879 if (optimized_type
== tls::TLSOPT_TO_LE
)
2881 if (tls_segment
== NULL
)
2883 gold_assert(parameters
->errors()->error_count() > 0
2884 || issue_undefined_symbol_error(gsym
));
2887 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
2888 rel
, r_type
, value
, view
,
2894 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
2895 ? GOT_TYPE_TLS_NOFFSET
2896 : GOT_TYPE_TLS_PAIR
);
2897 unsigned int got_offset
;
2900 gold_assert(gsym
->has_got_offset(got_type
));
2901 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
2905 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2906 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
2907 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
2908 - target
->got_size());
2910 if (optimized_type
== tls::TLSOPT_TO_IE
)
2912 this->tls_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
2913 got_offset
, view
, view_size
);
2916 else if (optimized_type
== tls::TLSOPT_NONE
)
2918 // Relocate the field with the offset of the pair of GOT
2920 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2924 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2925 _("unsupported reloc %u"),
2929 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2930 case elfcpp::R_386_TLS_DESC_CALL
:
2931 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
2932 if (optimized_type
== tls::TLSOPT_TO_LE
)
2934 if (tls_segment
== NULL
)
2936 gold_assert(parameters
->errors()->error_count() > 0
2937 || issue_undefined_symbol_error(gsym
));
2940 this->tls_desc_gd_to_le(relinfo
, relnum
, tls_segment
,
2941 rel
, r_type
, value
, view
,
2947 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
2948 ? GOT_TYPE_TLS_NOFFSET
2949 : GOT_TYPE_TLS_DESC
);
2950 unsigned int got_offset
= 0;
2951 if (r_type
== elfcpp::R_386_TLS_GOTDESC
2952 && optimized_type
== tls::TLSOPT_NONE
)
2954 // We created GOT entries in the .got.tlsdesc portion of
2955 // the .got.plt section, but the offset stored in the
2956 // symbol is the offset within .got.tlsdesc.
2957 got_offset
= (target
->got_size()
2958 + target
->got_plt_section()->data_size());
2962 gold_assert(gsym
->has_got_offset(got_type
));
2963 got_offset
+= gsym
->got_offset(got_type
) - target
->got_size();
2967 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2968 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
2969 got_offset
+= (object
->local_got_offset(r_sym
, got_type
)
2970 - target
->got_size());
2972 if (optimized_type
== tls::TLSOPT_TO_IE
)
2974 if (tls_segment
== NULL
)
2976 gold_assert(parameters
->errors()->error_count() > 0
2977 || issue_undefined_symbol_error(gsym
));
2980 this->tls_desc_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
2981 got_offset
, view
, view_size
);
2984 else if (optimized_type
== tls::TLSOPT_NONE
)
2986 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
2988 // Relocate the field with the offset of the pair of GOT
2990 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2995 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2996 _("unsupported reloc %u"),
3000 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
3001 if (this->local_dynamic_type_
== LOCAL_DYNAMIC_SUN
)
3003 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3004 _("both SUN and GNU model "
3005 "TLS relocations"));
3008 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
3009 if (optimized_type
== tls::TLSOPT_TO_LE
)
3011 if (tls_segment
== NULL
)
3013 gold_assert(parameters
->errors()->error_count() > 0
3014 || issue_undefined_symbol_error(gsym
));
3017 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rel
, r_type
,
3018 value
, view
, view_size
);
3021 else if (optimized_type
== tls::TLSOPT_NONE
)
3023 // Relocate the field with the offset of the GOT entry for
3024 // the module index.
3025 unsigned int got_offset
;
3026 got_offset
= (target
->got_mod_index_entry(NULL
, NULL
, NULL
)
3027 - target
->got_size());
3028 Relocate_functions
<32, false>::rel32(view
, got_offset
);
3031 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3032 _("unsupported reloc %u"),
3036 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
3037 if (optimized_type
== tls::TLSOPT_TO_LE
)
3039 // This reloc can appear in debugging sections, in which
3040 // case we must not convert to local-exec. We decide what
3041 // to do based on whether the section is marked as
3042 // containing executable code. That is what the GNU linker
3044 elfcpp::Shdr
<32, false> shdr(relinfo
->data_shdr
);
3045 if ((shdr
.get_sh_flags() & elfcpp::SHF_EXECINSTR
) != 0)
3047 if (tls_segment
== NULL
)
3049 gold_assert(parameters
->errors()->error_count() > 0
3050 || issue_undefined_symbol_error(gsym
));
3053 value
-= tls_segment
->memsz();
3056 Relocate_functions
<32, false>::rel32(view
, value
);
3059 case elfcpp::R_386_TLS_IE
: // Initial-exec
3060 case elfcpp::R_386_TLS_GOTIE
:
3061 case elfcpp::R_386_TLS_IE_32
:
3062 if (optimized_type
== tls::TLSOPT_TO_LE
)
3064 if (tls_segment
== NULL
)
3066 gold_assert(parameters
->errors()->error_count() > 0
3067 || issue_undefined_symbol_error(gsym
));
3070 Target_i386::Relocate::tls_ie_to_le(relinfo
, relnum
, tls_segment
,
3071 rel
, r_type
, value
, view
,
3075 else if (optimized_type
== tls::TLSOPT_NONE
)
3077 // Relocate the field with the offset of the GOT entry for
3078 // the tp-relative offset of the symbol.
3079 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
3080 ? GOT_TYPE_TLS_OFFSET
3081 : GOT_TYPE_TLS_NOFFSET
);
3082 unsigned int got_offset
;
3085 gold_assert(gsym
->has_got_offset(got_type
));
3086 got_offset
= gsym
->got_offset(got_type
);
3090 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
3091 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
3092 got_offset
= object
->local_got_offset(r_sym
, got_type
);
3094 // For the R_386_TLS_IE relocation, we need to apply the
3095 // absolute address of the GOT entry.
3096 if (r_type
== elfcpp::R_386_TLS_IE
)
3097 got_offset
+= target
->got_plt_section()->address();
3098 // All GOT offsets are relative to the end of the GOT.
3099 got_offset
-= target
->got_size();
3100 Relocate_functions
<32, false>::rel32(view
, got_offset
);
3103 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3104 _("unsupported reloc %u"),
3108 case elfcpp::R_386_TLS_LE
: // Local-exec
3109 // If we're creating a shared library, a dynamic relocation will
3110 // have been created for this location, so do not apply it now.
3111 if (!parameters
->options().shared())
3113 if (tls_segment
== NULL
)
3115 gold_assert(parameters
->errors()->error_count() > 0
3116 || issue_undefined_symbol_error(gsym
));
3119 value
-= tls_segment
->memsz();
3120 Relocate_functions
<32, false>::rel32(view
, value
);
3124 case elfcpp::R_386_TLS_LE_32
:
3125 // If we're creating a shared library, a dynamic relocation will
3126 // have been created for this location, so do not apply it now.
3127 if (!parameters
->options().shared())
3129 if (tls_segment
== NULL
)
3131 gold_assert(parameters
->errors()->error_count() > 0
3132 || issue_undefined_symbol_error(gsym
));
3135 value
= tls_segment
->memsz() - value
;
3136 Relocate_functions
<32, false>::rel32(view
, value
);
3142 // Do a relocation in which we convert a TLS General-Dynamic to a
3146 Target_i386::Relocate::tls_gd_to_le(const Relocate_info
<32, false>* relinfo
,
3148 Output_segment
* tls_segment
,
3149 const elfcpp::Rel
<32, false>& rel
,
3151 elfcpp::Elf_types
<32>::Elf_Addr value
,
3152 unsigned char* view
,
3153 section_size_type view_size
)
3155 // leal foo(,%reg,1),%eax; call ___tls_get_addr
3156 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
3157 // leal foo(%reg),%eax; call ___tls_get_addr
3158 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
3160 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3161 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
3163 unsigned char op1
= view
[-1];
3164 unsigned char op2
= view
[-2];
3166 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3167 op2
== 0x8d || op2
== 0x04);
3168 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
3174 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
3175 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
3176 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3177 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
3178 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3182 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3183 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
3184 if (rel
.get_r_offset() + 9 < view_size
3187 // There is a trailing nop. Use the size byte subl.
3188 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3193 // Use the five byte subl.
3194 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
3198 value
= tls_segment
->memsz() - value
;
3199 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
3201 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3203 this->skip_call_tls_get_addr_
= true;
3206 // Do a relocation in which we convert a TLS General-Dynamic to an
3210 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info
<32, false>* relinfo
,
3213 const elfcpp::Rel
<32, false>& rel
,
3215 elfcpp::Elf_types
<32>::Elf_Addr value
,
3216 unsigned char* view
,
3217 section_size_type view_size
)
3219 // leal foo(,%ebx,1),%eax; call ___tls_get_addr
3220 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
3222 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3223 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
3225 unsigned char op1
= view
[-1];
3226 unsigned char op2
= view
[-2];
3228 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3229 op2
== 0x8d || op2
== 0x04);
3230 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
3234 // FIXME: For now, support only the first (SIB) form.
3235 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), op2
== 0x04);
3239 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
3240 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
3241 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3242 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
3243 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
3247 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3248 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
3249 if (rel
.get_r_offset() + 9 < view_size
3252 // FIXME: This is not the right instruction sequence.
3253 // There is a trailing nop. Use the size byte subl.
3254 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3259 // FIXME: This is not the right instruction sequence.
3260 // Use the five byte subl.
3261 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
3265 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
3267 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3269 this->skip_call_tls_get_addr_
= true;
3272 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3273 // General-Dynamic to a Local-Exec.
3276 Target_i386::Relocate::tls_desc_gd_to_le(
3277 const Relocate_info
<32, false>* relinfo
,
3279 Output_segment
* tls_segment
,
3280 const elfcpp::Rel
<32, false>& rel
,
3281 unsigned int r_type
,
3282 elfcpp::Elf_types
<32>::Elf_Addr value
,
3283 unsigned char* view
,
3284 section_size_type view_size
)
3286 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
3288 // leal foo@TLSDESC(%ebx), %eax
3289 // ==> leal foo@NTPOFF, %eax
3290 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3291 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3292 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3293 view
[-2] == 0x8d && view
[-1] == 0x83);
3295 value
-= tls_segment
->memsz();
3296 Relocate_functions
<32, false>::rel32(view
, value
);
3300 // call *foo@TLSCALL(%eax)
3302 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
3303 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
3304 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3305 view
[0] == 0xff && view
[1] == 0x10);
3311 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3312 // General-Dynamic to an Initial-Exec.
3315 Target_i386::Relocate::tls_desc_gd_to_ie(
3316 const Relocate_info
<32, false>* relinfo
,
3319 const elfcpp::Rel
<32, false>& rel
,
3320 unsigned int r_type
,
3321 elfcpp::Elf_types
<32>::Elf_Addr value
,
3322 unsigned char* view
,
3323 section_size_type view_size
)
3325 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
3327 // leal foo@TLSDESC(%ebx), %eax
3328 // ==> movl foo@GOTNTPOFF(%ebx), %eax
3329 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3330 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3331 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3332 view
[-2] == 0x8d && view
[-1] == 0x83);
3334 Relocate_functions
<32, false>::rel32(view
, value
);
3338 // call *foo@TLSCALL(%eax)
3340 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
3341 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
3342 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3343 view
[0] == 0xff && view
[1] == 0x10);
3349 // Do a relocation in which we convert a TLS Local-Dynamic to a
3353 Target_i386::Relocate::tls_ld_to_le(const Relocate_info
<32, false>* relinfo
,
3356 const elfcpp::Rel
<32, false>& rel
,
3358 elfcpp::Elf_types
<32>::Elf_Addr
,
3359 unsigned char* view
,
3360 section_size_type view_size
)
3362 // leal foo(%reg), %eax; call ___tls_get_addr
3363 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
3365 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3366 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
3368 // FIXME: Does this test really always pass?
3369 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3370 view
[-2] == 0x8d && view
[-1] == 0x83);
3372 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
3374 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
3376 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3378 this->skip_call_tls_get_addr_
= true;
3381 // Do a relocation in which we convert a TLS Initial-Exec to a
3385 Target_i386::Relocate::tls_ie_to_le(const Relocate_info
<32, false>* relinfo
,
3387 Output_segment
* tls_segment
,
3388 const elfcpp::Rel
<32, false>& rel
,
3389 unsigned int r_type
,
3390 elfcpp::Elf_types
<32>::Elf_Addr value
,
3391 unsigned char* view
,
3392 section_size_type view_size
)
3394 // We have to actually change the instructions, which means that we
3395 // need to examine the opcodes to figure out which instruction we
3397 if (r_type
== elfcpp::R_386_TLS_IE
)
3399 // movl %gs:XX,%eax ==> movl $YY,%eax
3400 // movl %gs:XX,%reg ==> movl $YY,%reg
3401 // addl %gs:XX,%reg ==> addl $YY,%reg
3402 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -1);
3403 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3405 unsigned char op1
= view
[-1];
3408 // movl XX,%eax ==> movl $YY,%eax
3413 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3415 unsigned char op2
= view
[-2];
3418 // movl XX,%reg ==> movl $YY,%reg
3419 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3420 (op1
& 0xc7) == 0x05);
3422 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3424 else if (op2
== 0x03)
3426 // addl XX,%reg ==> addl $YY,%reg
3427 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3428 (op1
& 0xc7) == 0x05);
3430 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3433 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
3438 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
3439 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
3440 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
3441 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3442 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3444 unsigned char op1
= view
[-1];
3445 unsigned char op2
= view
[-2];
3446 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3447 (op1
& 0xc0) == 0x80 && (op1
& 7) != 4);
3450 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
3452 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3454 else if (op2
== 0x2b)
3456 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
3458 view
[-1] = 0xe8 | ((op1
>> 3) & 7);
3460 else if (op2
== 0x03)
3462 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
3464 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3467 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
3470 value
= tls_segment
->memsz() - value
;
3471 if (r_type
== elfcpp::R_386_TLS_IE
|| r_type
== elfcpp::R_386_TLS_GOTIE
)
3474 Relocate_functions
<32, false>::rel32(view
, value
);
3477 // Relocate section data.
3480 Target_i386::relocate_section(const Relocate_info
<32, false>* relinfo
,
3481 unsigned int sh_type
,
3482 const unsigned char* prelocs
,
3484 Output_section
* output_section
,
3485 bool needs_special_offset_handling
,
3486 unsigned char* view
,
3487 elfcpp::Elf_types
<32>::Elf_Addr address
,
3488 section_size_type view_size
,
3489 const Reloc_symbol_changes
* reloc_symbol_changes
)
3491 gold_assert(sh_type
== elfcpp::SHT_REL
);
3493 gold::relocate_section
<32, false, Target_i386
, elfcpp::SHT_REL
,
3494 Target_i386::Relocate
, gold::Default_comdat_behavior
>(
3500 needs_special_offset_handling
,
3504 reloc_symbol_changes
);
3507 // Return the size of a relocation while scanning during a relocatable
3511 Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
3512 unsigned int r_type
,
3517 case elfcpp::R_386_NONE
:
3518 case elfcpp::R_386_GNU_VTINHERIT
:
3519 case elfcpp::R_386_GNU_VTENTRY
:
3520 case elfcpp::R_386_TLS_GD
: // Global-dynamic
3521 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
3522 case elfcpp::R_386_TLS_DESC_CALL
:
3523 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
3524 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
3525 case elfcpp::R_386_TLS_IE
: // Initial-exec
3526 case elfcpp::R_386_TLS_IE_32
:
3527 case elfcpp::R_386_TLS_GOTIE
:
3528 case elfcpp::R_386_TLS_LE
: // Local-exec
3529 case elfcpp::R_386_TLS_LE_32
:
3532 case elfcpp::R_386_32
:
3533 case elfcpp::R_386_PC32
:
3534 case elfcpp::R_386_GOT32
:
3535 case elfcpp::R_386_PLT32
:
3536 case elfcpp::R_386_GOTOFF
:
3537 case elfcpp::R_386_GOTPC
:
3540 case elfcpp::R_386_16
:
3541 case elfcpp::R_386_PC16
:
3544 case elfcpp::R_386_8
:
3545 case elfcpp::R_386_PC8
:
3548 // These are relocations which should only be seen by the
3549 // dynamic linker, and should never be seen here.
3550 case elfcpp::R_386_COPY
:
3551 case elfcpp::R_386_GLOB_DAT
:
3552 case elfcpp::R_386_JUMP_SLOT
:
3553 case elfcpp::R_386_RELATIVE
:
3554 case elfcpp::R_386_IRELATIVE
:
3555 case elfcpp::R_386_TLS_TPOFF
:
3556 case elfcpp::R_386_TLS_DTPMOD32
:
3557 case elfcpp::R_386_TLS_DTPOFF32
:
3558 case elfcpp::R_386_TLS_TPOFF32
:
3559 case elfcpp::R_386_TLS_DESC
:
3560 object
->error(_("unexpected reloc %u in object file"), r_type
);
3563 case elfcpp::R_386_32PLT
:
3564 case elfcpp::R_386_TLS_GD_32
:
3565 case elfcpp::R_386_TLS_GD_PUSH
:
3566 case elfcpp::R_386_TLS_GD_CALL
:
3567 case elfcpp::R_386_TLS_GD_POP
:
3568 case elfcpp::R_386_TLS_LDM_32
:
3569 case elfcpp::R_386_TLS_LDM_PUSH
:
3570 case elfcpp::R_386_TLS_LDM_CALL
:
3571 case elfcpp::R_386_TLS_LDM_POP
:
3572 case elfcpp::R_386_USED_BY_INTEL_200
:
3574 object
->error(_("unsupported reloc %u in object file"), r_type
);
3579 // Scan the relocs during a relocatable link.
3582 Target_i386::scan_relocatable_relocs(Symbol_table
* symtab
,
3584 Sized_relobj_file
<32, false>* object
,
3585 unsigned int data_shndx
,
3586 unsigned int sh_type
,
3587 const unsigned char* prelocs
,
3589 Output_section
* output_section
,
3590 bool needs_special_offset_handling
,
3591 size_t local_symbol_count
,
3592 const unsigned char* plocal_symbols
,
3593 Relocatable_relocs
* rr
)
3595 gold_assert(sh_type
== elfcpp::SHT_REL
);
3597 typedef gold::Default_scan_relocatable_relocs
<elfcpp::SHT_REL
,
3598 Relocatable_size_for_reloc
> Scan_relocatable_relocs
;
3600 gold::scan_relocatable_relocs
<32, false, elfcpp::SHT_REL
,
3601 Scan_relocatable_relocs
>(
3609 needs_special_offset_handling
,
3615 // Emit relocations for a section.
3618 Target_i386::relocate_relocs(
3619 const Relocate_info
<32, false>* relinfo
,
3620 unsigned int sh_type
,
3621 const unsigned char* prelocs
,
3623 Output_section
* output_section
,
3624 elfcpp::Elf_types
<32>::Elf_Off offset_in_output_section
,
3625 const Relocatable_relocs
* rr
,
3626 unsigned char* view
,
3627 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
3628 section_size_type view_size
,
3629 unsigned char* reloc_view
,
3630 section_size_type reloc_view_size
)
3632 gold_assert(sh_type
== elfcpp::SHT_REL
);
3634 gold::relocate_relocs
<32, false, elfcpp::SHT_REL
>(
3639 offset_in_output_section
,
3648 // Return the value to use for a dynamic which requires special
3649 // treatment. This is how we support equality comparisons of function
3650 // pointers across shared library boundaries, as described in the
3651 // processor specific ABI supplement.
3654 Target_i386::do_dynsym_value(const Symbol
* gsym
) const
3656 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
3657 return this->plt_address_for_global(gsym
);
3660 // Return a string used to fill a code section with nops to take up
3661 // the specified length.
3664 Target_i386::do_code_fill(section_size_type length
) const
3668 // Build a jmp instruction to skip over the bytes.
3669 unsigned char jmp
[5];
3671 elfcpp::Swap_unaligned
<32, false>::writeval(jmp
+ 1, length
- 5);
3672 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
3673 + std::string(length
- 5, static_cast<char>(0x90)));
3676 // Nop sequences of various lengths.
3677 const char nop1
[1] = { '\x90' }; // nop
3678 const char nop2
[2] = { '\x66', '\x90' }; // xchg %ax %ax
3679 const char nop3
[3] = { '\x8d', '\x76', '\x00' }; // leal 0(%esi),%esi
3680 const char nop4
[4] = { '\x8d', '\x74', '\x26', // leal 0(%esi,1),%esi
3682 const char nop5
[5] = { '\x90', '\x8d', '\x74', // nop
3683 '\x26', '\x00' }; // leal 0(%esi,1),%esi
3684 const char nop6
[6] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3685 '\x00', '\x00', '\x00' };
3686 const char nop7
[7] = { '\x8d', '\xb4', '\x26', // leal 0L(%esi,1),%esi
3687 '\x00', '\x00', '\x00',
3689 const char nop8
[8] = { '\x90', '\x8d', '\xb4', // nop
3690 '\x26', '\x00', '\x00', // leal 0L(%esi,1),%esi
3692 const char nop9
[9] = { '\x89', '\xf6', '\x8d', // movl %esi,%esi
3693 '\xbc', '\x27', '\x00', // leal 0L(%edi,1),%edi
3694 '\x00', '\x00', '\x00' };
3695 const char nop10
[10] = { '\x8d', '\x76', '\x00', // leal 0(%esi),%esi
3696 '\x8d', '\xbc', '\x27', // leal 0L(%edi,1),%edi
3697 '\x00', '\x00', '\x00',
3699 const char nop11
[11] = { '\x8d', '\x74', '\x26', // leal 0(%esi,1),%esi
3700 '\x00', '\x8d', '\xbc', // leal 0L(%edi,1),%edi
3701 '\x27', '\x00', '\x00',
3703 const char nop12
[12] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3704 '\x00', '\x00', '\x00', // leal 0L(%edi),%edi
3705 '\x8d', '\xbf', '\x00',
3706 '\x00', '\x00', '\x00' };
3707 const char nop13
[13] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3708 '\x00', '\x00', '\x00', // leal 0L(%edi,1),%edi
3709 '\x8d', '\xbc', '\x27',
3710 '\x00', '\x00', '\x00',
3712 const char nop14
[14] = { '\x8d', '\xb4', '\x26', // leal 0L(%esi,1),%esi
3713 '\x00', '\x00', '\x00', // leal 0L(%edi,1),%edi
3714 '\x00', '\x8d', '\xbc',
3715 '\x27', '\x00', '\x00',
3717 const char nop15
[15] = { '\xeb', '\x0d', '\x90', // jmp .+15
3718 '\x90', '\x90', '\x90', // nop,nop,nop,...
3719 '\x90', '\x90', '\x90',
3720 '\x90', '\x90', '\x90',
3721 '\x90', '\x90', '\x90' };
3723 const char* nops
[16] = {
3725 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
3726 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
3729 return std::string(nops
[length
], length
);
3732 // Return the value to use for the base of a DW_EH_PE_datarel offset
3733 // in an FDE. Solaris and SVR4 use DW_EH_PE_datarel because their
3734 // assembler can not write out the difference between two labels in
3735 // different sections, so instead of using a pc-relative value they
3736 // use an offset from the GOT.
3739 Target_i386::do_ehframe_datarel_base() const
3741 gold_assert(this->global_offset_table_
!= NULL
);
3742 Symbol
* sym
= this->global_offset_table_
;
3743 Sized_symbol
<32>* ssym
= static_cast<Sized_symbol
<32>*>(sym
);
3744 return ssym
->value();
3747 // Return whether SYM should be treated as a call to a non-split
3748 // function. We don't want that to be true of a call to a
3749 // get_pc_thunk function.
3752 Target_i386::do_is_call_to_non_split(const Symbol
* sym
, unsigned int) const
3754 return (sym
->type() == elfcpp::STT_FUNC
3755 && !is_prefix_of("__i686.get_pc_thunk.", sym
->name()));
3758 // FNOFFSET in section SHNDX in OBJECT is the start of a function
3759 // compiled with -fsplit-stack. The function calls non-split-stack
3760 // code. We have to change the function so that it always ensures
3761 // that it has enough stack space to run some random function.
3764 Target_i386::do_calls_non_split(Relobj
* object
, unsigned int shndx
,
3765 section_offset_type fnoffset
,
3766 section_size_type fnsize
,
3767 unsigned char* view
,
3768 section_size_type view_size
,
3770 std::string
* to
) const
3772 // The function starts with a comparison of the stack pointer and a
3773 // field in the TCB. This is followed by a jump.
3776 if (this->match_view(view
, view_size
, fnoffset
, "\x65\x3b\x25", 3)
3779 // We will call __morestack if the carry flag is set after this
3780 // comparison. We turn the comparison into an stc instruction
3782 view
[fnoffset
] = '\xf9';
3783 this->set_view_to_nop(view
, view_size
, fnoffset
+ 1, 6);
3785 // lea NN(%esp),%ecx
3786 // lea NN(%esp),%edx
3787 else if ((this->match_view(view
, view_size
, fnoffset
, "\x8d\x8c\x24", 3)
3788 || this->match_view(view
, view_size
, fnoffset
, "\x8d\x94\x24", 3))
3791 // This is loading an offset from the stack pointer for a
3792 // comparison. The offset is negative, so we decrease the
3793 // offset by the amount of space we need for the stack. This
3794 // means we will avoid calling __morestack if there happens to
3795 // be plenty of space on the stack already.
3796 unsigned char* pval
= view
+ fnoffset
+ 3;
3797 uint32_t val
= elfcpp::Swap_unaligned
<32, false>::readval(pval
);
3798 val
-= parameters
->options().split_stack_adjust_size();
3799 elfcpp::Swap_unaligned
<32, false>::writeval(pval
, val
);
3803 if (!object
->has_no_split_stack())
3804 object
->error(_("failed to match split-stack sequence at "
3805 "section %u offset %0zx"),
3806 shndx
, static_cast<size_t>(fnoffset
));
3810 // We have to change the function so that it calls
3811 // __morestack_non_split instead of __morestack. The former will
3812 // allocate additional stack space.
3813 *from
= "__morestack";
3814 *to
= "__morestack_non_split";
3817 // The selector for i386 object files. Note this is never instantiated
3818 // directly. It's only used in Target_selector_i386_nacl, below.
3820 class Target_selector_i386
: public Target_selector_freebsd
3823 Target_selector_i386()
3824 : Target_selector_freebsd(elfcpp::EM_386
, 32, false,
3825 "elf32-i386", "elf32-i386-freebsd",
3830 do_instantiate_target()
3831 { return new Target_i386(); }
3834 // NaCl variant. It uses different PLT contents.
3836 class Output_data_plt_i386_nacl
: public Output_data_plt_i386
3839 Output_data_plt_i386_nacl(Layout
* layout
,
3840 Output_data_space
* got_plt
,
3841 Output_data_space
* got_irelative
)
3842 : Output_data_plt_i386(layout
, plt_entry_size
, got_plt
, got_irelative
)
3846 virtual unsigned int
3847 do_get_plt_entry_size() const
3848 { return plt_entry_size
; }
3851 do_add_eh_frame(Layout
* layout
)
3853 layout
->add_eh_frame_for_plt(this, plt_eh_frame_cie
, plt_eh_frame_cie_size
,
3854 plt_eh_frame_fde
, plt_eh_frame_fde_size
);
3857 // The size of an entry in the PLT.
3858 static const int plt_entry_size
= 64;
3860 // The .eh_frame unwind information for the PLT.
3861 static const int plt_eh_frame_fde_size
= 32;
3862 static const unsigned char plt_eh_frame_fde
[plt_eh_frame_fde_size
];
3865 class Output_data_plt_i386_nacl_exec
: public Output_data_plt_i386_nacl
3868 Output_data_plt_i386_nacl_exec(Layout
* layout
,
3869 Output_data_space
* got_plt
,
3870 Output_data_space
* got_irelative
)
3871 : Output_data_plt_i386_nacl(layout
, got_plt
, got_irelative
)
3876 do_fill_first_plt_entry(unsigned char* pov
,
3877 elfcpp::Elf_types
<32>::Elf_Addr got_address
);
3879 virtual unsigned int
3880 do_fill_plt_entry(unsigned char* pov
,
3881 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
3882 unsigned int got_offset
,
3883 unsigned int plt_offset
,
3884 unsigned int plt_rel_offset
);
3887 // The first entry in the PLT for an executable.
3888 static const unsigned char first_plt_entry
[plt_entry_size
];
3890 // Other entries in the PLT for an executable.
3891 static const unsigned char plt_entry
[plt_entry_size
];
3894 class Output_data_plt_i386_nacl_dyn
: public Output_data_plt_i386_nacl
3897 Output_data_plt_i386_nacl_dyn(Layout
* layout
,
3898 Output_data_space
* got_plt
,
3899 Output_data_space
* got_irelative
)
3900 : Output_data_plt_i386_nacl(layout
, got_plt
, got_irelative
)
3905 do_fill_first_plt_entry(unsigned char* pov
, elfcpp::Elf_types
<32>::Elf_Addr
);
3907 virtual unsigned int
3908 do_fill_plt_entry(unsigned char* pov
,
3909 elfcpp::Elf_types
<32>::Elf_Addr
,
3910 unsigned int got_offset
,
3911 unsigned int plt_offset
,
3912 unsigned int plt_rel_offset
);
3915 // The first entry in the PLT for a shared object.
3916 static const unsigned char first_plt_entry
[plt_entry_size
];
3918 // Other entries in the PLT for a shared object.
3919 static const unsigned char plt_entry
[plt_entry_size
];
3922 class Target_i386_nacl
: public Target_i386
3926 : Target_i386(&i386_nacl_info
)
3930 virtual Output_data_plt_i386
*
3931 do_make_data_plt(Layout
* layout
,
3932 Output_data_space
* got_plt
,
3933 Output_data_space
* got_irelative
,
3937 return new Output_data_plt_i386_nacl_dyn(layout
, got_plt
, got_irelative
);
3939 return new Output_data_plt_i386_nacl_exec(layout
, got_plt
, got_irelative
);
3943 do_code_fill(section_size_type length
) const;
3946 static const Target::Target_info i386_nacl_info
;
3949 const Target::Target_info
Target_i386_nacl::i386_nacl_info
=
3952 false, // is_big_endian
3953 elfcpp::EM_386
, // machine_code
3954 false, // has_make_symbol
3955 false, // has_resolve
3956 true, // has_code_fill
3957 true, // is_default_stack_executable
3958 true, // can_icf_inline_merge_sections
3960 "/lib/ld-nacl-x86-32.so.1", // dynamic_linker
3961 0x20000, // default_text_segment_address
3962 0x10000, // abi_pagesize (overridable by -z max-page-size)
3963 0x10000, // common_pagesize (overridable by -z common-page-size)
3964 true, // isolate_execinstr
3965 0x10000000, // rosegment_gap
3966 elfcpp::SHN_UNDEF
, // small_common_shndx
3967 elfcpp::SHN_UNDEF
, // large_common_shndx
3968 0, // small_common_section_flags
3969 0, // large_common_section_flags
3970 NULL
, // attributes_section
3971 NULL
, // attributes_vendor
3972 "_start" // entry_symbol_name
3975 #define NACLMASK 0xe0 // 32-byte alignment mask
3978 Output_data_plt_i386_nacl_exec::first_plt_entry
[plt_entry_size
] =
3980 0xff, 0x35, // pushl contents of memory address
3981 0, 0, 0, 0, // replaced with address of .got + 4
3982 0x8b, 0x0d, // movl contents of address, %ecx
3983 0, 0, 0, 0, // replaced with address of .got + 8
3984 0x83, 0xe1, NACLMASK
, // andl $NACLMASK, %ecx
3985 0xff, 0xe1, // jmp *%ecx
3986 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3987 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3988 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3989 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3990 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3991 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3992 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3993 0x90, 0x90, 0x90, 0x90, 0x90
3997 Output_data_plt_i386_nacl_exec::do_fill_first_plt_entry(
3999 elfcpp::Elf_types
<32>::Elf_Addr got_address
)
4001 memcpy(pov
, first_plt_entry
, plt_entry_size
);
4002 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 4);
4003 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 8);
4006 // The first entry in the PLT for a shared object.
4009 Output_data_plt_i386_nacl_dyn::first_plt_entry
[plt_entry_size
] =
4011 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
4012 0x8b, 0x4b, 0x08, // mov 0x8(%ebx), %ecx
4013 0x83, 0xe1, NACLMASK
, // andl $NACLMASK, %ecx
4014 0xff, 0xe1, // jmp *%ecx
4015 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4016 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4017 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4018 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4019 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4020 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4021 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4022 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4023 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4024 0x90, 0x90, 0x90, 0x90, 0x90 // nops
4028 Output_data_plt_i386_nacl_dyn::do_fill_first_plt_entry(
4030 elfcpp::Elf_types
<32>::Elf_Addr
)
4032 memcpy(pov
, first_plt_entry
, plt_entry_size
);
4035 // Subsequent entries in the PLT for an executable.
4038 Output_data_plt_i386_nacl_exec::plt_entry
[plt_entry_size
] =
4040 0x8b, 0x0d, // movl contents of address, %ecx */
4041 0, 0, 0, 0, // replaced with address of symbol in .got
4042 0x83, 0xe1, NACLMASK
, // andl $NACLMASK, %ecx
4043 0xff, 0xe1, // jmp *%ecx
4045 // Pad to the next 32-byte boundary with nop instructions.
4047 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4048 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4050 // Lazy GOT entries point here (32-byte aligned).
4051 0x68, // pushl immediate
4052 0, 0, 0, 0, // replaced with offset into relocation table
4053 0xe9, // jmp relative
4054 0, 0, 0, 0, // replaced with offset to start of .plt
4056 // Pad to the next 32-byte boundary with nop instructions.
4057 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4058 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4063 Output_data_plt_i386_nacl_exec::do_fill_plt_entry(
4065 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
4066 unsigned int got_offset
,
4067 unsigned int plt_offset
,
4068 unsigned int plt_rel_offset
)
4070 memcpy(pov
, plt_entry
, plt_entry_size
);
4071 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
4072 got_address
+ got_offset
);
4073 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 33, plt_rel_offset
);
4074 elfcpp::Swap
<32, false>::writeval(pov
+ 38, - (plt_offset
+ 38 + 4));
4078 // Subsequent entries in the PLT for a shared object.
4081 Output_data_plt_i386_nacl_dyn::plt_entry
[plt_entry_size
] =
4083 0x8b, 0x8b, // movl offset(%ebx), %ecx
4084 0, 0, 0, 0, // replaced with offset of symbol in .got
4085 0x83, 0xe1, 0xe0, // andl $NACLMASK, %ecx
4086 0xff, 0xe1, // jmp *%ecx
4088 // Pad to the next 32-byte boundary with nop instructions.
4090 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4091 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4093 // Lazy GOT entries point here (32-byte aligned).
4094 0x68, // pushl immediate
4095 0, 0, 0, 0, // replaced with offset into relocation table.
4096 0xe9, // jmp relative
4097 0, 0, 0, 0, // replaced with offset to start of .plt.
4099 // Pad to the next 32-byte boundary with nop instructions.
4100 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4101 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4106 Output_data_plt_i386_nacl_dyn::do_fill_plt_entry(
4108 elfcpp::Elf_types
<32>::Elf_Addr
,
4109 unsigned int got_offset
,
4110 unsigned int plt_offset
,
4111 unsigned int plt_rel_offset
)
4113 memcpy(pov
, plt_entry
, plt_entry_size
);
4114 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
4115 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 33, plt_rel_offset
);
4116 elfcpp::Swap
<32, false>::writeval(pov
+ 38, - (plt_offset
+ 38 + 4));
4121 Output_data_plt_i386_nacl::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
4123 0, 0, 0, 0, // Replaced with offset to .plt.
4124 0, 0, 0, 0, // Replaced with size of .plt.
4125 0, // Augmentation size.
4126 elfcpp::DW_CFA_def_cfa_offset
, 8, // DW_CFA_def_cfa_offset: 8.
4127 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
4128 elfcpp::DW_CFA_def_cfa_offset
, 12, // DW_CFA_def_cfa_offset: 12.
4129 elfcpp::DW_CFA_advance_loc
+ 58, // Advance 58 to __PLT__ + 64.
4130 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
4131 13, // Block length.
4132 elfcpp::DW_OP_breg4
, 4, // Push %esp + 4.
4133 elfcpp::DW_OP_breg8
, 0, // Push %eip.
4134 elfcpp::DW_OP_const1u
, 63, // Push 0x3f.
4135 elfcpp::DW_OP_and
, // & (%eip & 0x3f).
4136 elfcpp::DW_OP_const1u
, 37, // Push 0x25.
4137 elfcpp::DW_OP_ge
, // >= ((%eip & 0x3f) >= 0x25)
4138 elfcpp::DW_OP_lit2
, // Push 2.
4139 elfcpp::DW_OP_shl
, // << (((%eip & 0x3f) >= 0x25) << 2)
4140 elfcpp::DW_OP_plus
, // + ((((%eip&0x3f)>=0x25)<<2)+%esp+4
4141 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
4145 // Return a string used to fill a code section with nops.
4146 // For NaCl, long NOPs are only valid if they do not cross
4147 // bundle alignment boundaries, so keep it simple with one-byte NOPs.
4149 Target_i386_nacl::do_code_fill(section_size_type length
) const
4151 return std::string(length
, static_cast<char>(0x90));
4154 // The selector for i386-nacl object files.
4156 class Target_selector_i386_nacl
4157 : public Target_selector_nacl
<Target_selector_i386
, Target_i386_nacl
>
4160 Target_selector_i386_nacl()
4161 : Target_selector_nacl
<Target_selector_i386
,
4162 Target_i386_nacl
>("x86-32",
4168 Target_selector_i386_nacl target_selector_i386
;
4170 } // End anonymous namespace.