1 // i386.cc -- i386 target support for gold.
3 // Copyright 2006, 2007, 2008, 2009, 2010, 2011, 2012
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 off_t 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
863 // Get the GOT section, creating it if necessary.
865 Output_data_got
<32, false>*
866 Target_i386::got_section(Symbol_table
* symtab
, Layout
* layout
)
868 if (this->got_
== NULL
)
870 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
872 this->got_
= new Output_data_got
<32, false>();
874 // When using -z now, we can treat .got.plt as a relro section.
875 // Without -z now, it is modified after program startup by lazy
877 bool is_got_plt_relro
= parameters
->options().now();
878 Output_section_order got_order
= (is_got_plt_relro
881 Output_section_order got_plt_order
= (is_got_plt_relro
883 : ORDER_NON_RELRO_FIRST
);
885 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
887 | elfcpp::SHF_WRITE
),
888 this->got_
, got_order
, true);
890 this->got_plt_
= new Output_data_space(4, "** GOT PLT");
891 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
893 | elfcpp::SHF_WRITE
),
894 this->got_plt_
, got_plt_order
,
897 // The first three entries are reserved.
898 this->got_plt_
->set_current_data_size(3 * 4);
900 if (!is_got_plt_relro
)
902 // Those bytes can go into the relro segment.
903 layout
->increase_relro(3 * 4);
906 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
907 this->global_offset_table_
=
908 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
909 Symbol_table::PREDEFINED
,
911 0, 0, elfcpp::STT_OBJECT
,
913 elfcpp::STV_HIDDEN
, 0,
916 // If there are any IRELATIVE relocations, they get GOT entries
917 // in .got.plt after the jump slot relocations.
918 this->got_irelative_
= new Output_data_space(4, "** GOT IRELATIVE PLT");
919 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
921 | elfcpp::SHF_WRITE
),
922 this->got_irelative_
,
923 got_plt_order
, is_got_plt_relro
);
925 // If there are any TLSDESC relocations, they get GOT entries in
926 // .got.plt after the jump slot entries.
927 this->got_tlsdesc_
= new Output_data_got
<32, false>();
928 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
930 | elfcpp::SHF_WRITE
),
932 got_plt_order
, is_got_plt_relro
);
938 // Get the dynamic reloc section, creating it if necessary.
940 Target_i386::Reloc_section
*
941 Target_i386::rel_dyn_section(Layout
* layout
)
943 if (this->rel_dyn_
== NULL
)
945 gold_assert(layout
!= NULL
);
946 this->rel_dyn_
= new Reloc_section(parameters
->options().combreloc());
947 layout
->add_output_section_data(".rel.dyn", elfcpp::SHT_REL
,
948 elfcpp::SHF_ALLOC
, this->rel_dyn_
,
949 ORDER_DYNAMIC_RELOCS
, false);
951 return this->rel_dyn_
;
954 // Get the section to use for IRELATIVE relocs, creating it if
955 // necessary. These go in .rel.dyn, but only after all other dynamic
956 // relocations. They need to follow the other dynamic relocations so
957 // that they can refer to global variables initialized by those
960 Target_i386::Reloc_section
*
961 Target_i386::rel_irelative_section(Layout
* layout
)
963 if (this->rel_irelative_
== NULL
)
965 // Make sure we have already create the dynamic reloc section.
966 this->rel_dyn_section(layout
);
967 this->rel_irelative_
= new Reloc_section(false);
968 layout
->add_output_section_data(".rel.dyn", elfcpp::SHT_REL
,
969 elfcpp::SHF_ALLOC
, this->rel_irelative_
,
970 ORDER_DYNAMIC_RELOCS
, false);
971 gold_assert(this->rel_dyn_
->output_section()
972 == this->rel_irelative_
->output_section());
974 return this->rel_irelative_
;
977 // Create the PLT section. The ordinary .got section is an argument,
978 // since we need to refer to the start. We also create our own .got
979 // section just for PLT entries.
981 Output_data_plt_i386::Output_data_plt_i386(Layout
* layout
,
983 Output_data_space
* got_plt
,
984 Output_data_space
* got_irelative
)
985 : Output_section_data(addralign
),
986 layout_(layout
), tls_desc_rel_(NULL
),
987 irelative_rel_(NULL
), got_plt_(got_plt
), got_irelative_(got_irelative
),
988 count_(0), irelative_count_(0), global_ifuncs_(), local_ifuncs_()
990 this->rel_
= new Reloc_section(false);
991 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
992 elfcpp::SHF_ALLOC
, this->rel_
,
993 ORDER_DYNAMIC_PLT_RELOCS
, false);
997 Output_data_plt_i386::do_adjust_output_section(Output_section
* os
)
999 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
1000 // linker, and so do we.
1004 // Add an entry to the PLT.
1007 Output_data_plt_i386::add_entry(Symbol_table
* symtab
, Layout
* layout
,
1010 gold_assert(!gsym
->has_plt_offset());
1012 // Every PLT entry needs a reloc.
1013 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1014 && gsym
->can_use_relative_reloc(false))
1016 gsym
->set_plt_offset(this->irelative_count_
* this->get_plt_entry_size());
1017 ++this->irelative_count_
;
1018 section_offset_type got_offset
=
1019 this->got_irelative_
->current_data_size();
1020 this->got_irelative_
->set_current_data_size(got_offset
+ 4);
1021 Reloc_section
* rel
= this->rel_irelative(symtab
, layout
);
1022 rel
->add_symbolless_global_addend(gsym
, elfcpp::R_386_IRELATIVE
,
1023 this->got_irelative_
, got_offset
);
1024 struct Global_ifunc gi
;
1026 gi
.got_offset
= got_offset
;
1027 this->global_ifuncs_
.push_back(gi
);
1031 // When setting the PLT offset we skip the initial reserved PLT
1033 gsym
->set_plt_offset((this->count_
+ 1) * this->get_plt_entry_size());
1037 section_offset_type got_offset
= this->got_plt_
->current_data_size();
1039 // Every PLT entry needs a GOT entry which points back to the
1040 // PLT entry (this will be changed by the dynamic linker,
1041 // normally lazily when the function is called).
1042 this->got_plt_
->set_current_data_size(got_offset
+ 4);
1044 gsym
->set_needs_dynsym_entry();
1045 this->rel_
->add_global(gsym
, elfcpp::R_386_JUMP_SLOT
, this->got_plt_
,
1049 // Note that we don't need to save the symbol. The contents of the
1050 // PLT are independent of which symbols are used. The symbols only
1051 // appear in the relocations.
1054 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
1058 Output_data_plt_i386::add_local_ifunc_entry(
1059 Symbol_table
* symtab
,
1061 Sized_relobj_file
<32, false>* relobj
,
1062 unsigned int local_sym_index
)
1064 unsigned int plt_offset
= this->irelative_count_
* this->get_plt_entry_size();
1065 ++this->irelative_count_
;
1067 section_offset_type got_offset
= this->got_irelative_
->current_data_size();
1069 // Every PLT entry needs a GOT entry which points back to the PLT
1071 this->got_irelative_
->set_current_data_size(got_offset
+ 4);
1073 // Every PLT entry needs a reloc.
1074 Reloc_section
* rel
= this->rel_irelative(symtab
, layout
);
1075 rel
->add_symbolless_local_addend(relobj
, local_sym_index
,
1076 elfcpp::R_386_IRELATIVE
,
1077 this->got_irelative_
, got_offset
);
1079 struct Local_ifunc li
;
1081 li
.local_sym_index
= local_sym_index
;
1082 li
.got_offset
= got_offset
;
1083 this->local_ifuncs_
.push_back(li
);
1088 // Return where the TLS_DESC relocations should go, creating it if
1089 // necessary. These follow the JUMP_SLOT relocations.
1091 Output_data_plt_i386::Reloc_section
*
1092 Output_data_plt_i386::rel_tls_desc(Layout
* layout
)
1094 if (this->tls_desc_rel_
== NULL
)
1096 this->tls_desc_rel_
= new Reloc_section(false);
1097 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
1098 elfcpp::SHF_ALLOC
, this->tls_desc_rel_
,
1099 ORDER_DYNAMIC_PLT_RELOCS
, false);
1100 gold_assert(this->tls_desc_rel_
->output_section()
1101 == this->rel_
->output_section());
1103 return this->tls_desc_rel_
;
1106 // Return where the IRELATIVE relocations should go in the PLT. These
1107 // follow the JUMP_SLOT and TLS_DESC relocations.
1109 Output_data_plt_i386::Reloc_section
*
1110 Output_data_plt_i386::rel_irelative(Symbol_table
* symtab
, Layout
* layout
)
1112 if (this->irelative_rel_
== NULL
)
1114 // Make sure we have a place for the TLS_DESC relocations, in
1115 // case we see any later on.
1116 this->rel_tls_desc(layout
);
1117 this->irelative_rel_
= new Reloc_section(false);
1118 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
1119 elfcpp::SHF_ALLOC
, this->irelative_rel_
,
1120 ORDER_DYNAMIC_PLT_RELOCS
, false);
1121 gold_assert(this->irelative_rel_
->output_section()
1122 == this->rel_
->output_section());
1124 if (parameters
->doing_static_link())
1126 // A statically linked executable will only have a .rel.plt
1127 // section to hold R_386_IRELATIVE relocs for STT_GNU_IFUNC
1128 // symbols. The library will use these symbols to locate
1129 // the IRELATIVE relocs at program startup time.
1130 symtab
->define_in_output_data("__rel_iplt_start", NULL
,
1131 Symbol_table::PREDEFINED
,
1132 this->irelative_rel_
, 0, 0,
1133 elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
1134 elfcpp::STV_HIDDEN
, 0, false, true);
1135 symtab
->define_in_output_data("__rel_iplt_end", NULL
,
1136 Symbol_table::PREDEFINED
,
1137 this->irelative_rel_
, 0, 0,
1138 elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
1139 elfcpp::STV_HIDDEN
, 0, true, true);
1142 return this->irelative_rel_
;
1145 // Return the PLT address to use for a global symbol.
1148 Output_data_plt_i386::address_for_global(const Symbol
* gsym
)
1150 uint64_t offset
= 0;
1151 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1152 && gsym
->can_use_relative_reloc(false))
1153 offset
= (this->count_
+ 1) * this->get_plt_entry_size();
1154 return this->address() + offset
;
1157 // Return the PLT address to use for a local symbol. These are always
1158 // IRELATIVE relocs.
1161 Output_data_plt_i386::address_for_local(const Relobj
*, unsigned int)
1163 return this->address() + (this->count_
+ 1) * this->get_plt_entry_size();
1166 // The first entry in the PLT for an executable.
1168 const unsigned char Output_data_plt_i386_exec::first_plt_entry
[plt_entry_size
] =
1170 0xff, 0x35, // pushl contents of memory address
1171 0, 0, 0, 0, // replaced with address of .got + 4
1172 0xff, 0x25, // jmp indirect
1173 0, 0, 0, 0, // replaced with address of .got + 8
1174 0, 0, 0, 0 // unused
1178 Output_data_plt_i386_exec::do_fill_first_plt_entry(
1180 elfcpp::Elf_types
<32>::Elf_Addr got_address
)
1182 memcpy(pov
, first_plt_entry
, plt_entry_size
);
1183 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 4);
1184 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 8);
1187 // The first entry in the PLT for a shared object.
1189 const unsigned char Output_data_plt_i386_dyn::first_plt_entry
[plt_entry_size
] =
1191 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
1192 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
1193 0, 0, 0, 0 // unused
1197 Output_data_plt_i386_dyn::do_fill_first_plt_entry(
1199 elfcpp::Elf_types
<32>::Elf_Addr
)
1201 memcpy(pov
, first_plt_entry
, plt_entry_size
);
1204 // Subsequent entries in the PLT for an executable.
1206 const unsigned char Output_data_plt_i386_exec::plt_entry
[plt_entry_size
] =
1208 0xff, 0x25, // jmp indirect
1209 0, 0, 0, 0, // replaced with address of symbol in .got
1210 0x68, // pushl immediate
1211 0, 0, 0, 0, // replaced with offset into relocation table
1212 0xe9, // jmp relative
1213 0, 0, 0, 0 // replaced with offset to start of .plt
1217 Output_data_plt_i386_exec::do_fill_plt_entry(
1219 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
1220 unsigned int got_offset
,
1221 unsigned int plt_offset
,
1222 unsigned int plt_rel_offset
)
1224 memcpy(pov
, plt_entry
, plt_entry_size
);
1225 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
1226 got_address
+ got_offset
);
1227 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_rel_offset
);
1228 elfcpp::Swap
<32, false>::writeval(pov
+ 12, - (plt_offset
+ 12 + 4));
1232 // Subsequent entries in the PLT for a shared object.
1234 const unsigned char Output_data_plt_i386_dyn::plt_entry
[plt_entry_size
] =
1236 0xff, 0xa3, // jmp *offset(%ebx)
1237 0, 0, 0, 0, // replaced with offset of symbol in .got
1238 0x68, // pushl immediate
1239 0, 0, 0, 0, // replaced with offset into relocation table
1240 0xe9, // jmp relative
1241 0, 0, 0, 0 // replaced with offset to start of .plt
1245 Output_data_plt_i386_dyn::do_fill_plt_entry(unsigned char* pov
,
1246 elfcpp::Elf_types
<32>::Elf_Addr
,
1247 unsigned int got_offset
,
1248 unsigned int plt_offset
,
1249 unsigned int plt_rel_offset
)
1251 memcpy(pov
, plt_entry
, plt_entry_size
);
1252 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
1253 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_rel_offset
);
1254 elfcpp::Swap
<32, false>::writeval(pov
+ 12, - (plt_offset
+ 12 + 4));
1258 // The .eh_frame unwind information for the PLT.
1261 Output_data_plt_i386::plt_eh_frame_cie
[plt_eh_frame_cie_size
] =
1264 'z', // Augmentation: augmentation size included.
1265 'R', // Augmentation: FDE encoding included.
1266 '\0', // End of augmentation string.
1267 1, // Code alignment factor.
1268 0x7c, // Data alignment factor.
1269 8, // Return address column.
1270 1, // Augmentation size.
1271 (elfcpp::DW_EH_PE_pcrel
// FDE encoding.
1272 | elfcpp::DW_EH_PE_sdata4
),
1273 elfcpp::DW_CFA_def_cfa
, 4, 4, // DW_CFA_def_cfa: r4 (esp) ofs 4.
1274 elfcpp::DW_CFA_offset
+ 8, 1, // DW_CFA_offset: r8 (eip) at cfa-4.
1275 elfcpp::DW_CFA_nop
, // Align to 16 bytes.
1280 Output_data_plt_i386_standard::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
1282 0, 0, 0, 0, // Replaced with offset to .plt.
1283 0, 0, 0, 0, // Replaced with size of .plt.
1284 0, // Augmentation size.
1285 elfcpp::DW_CFA_def_cfa_offset
, 8, // DW_CFA_def_cfa_offset: 8.
1286 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
1287 elfcpp::DW_CFA_def_cfa_offset
, 12, // DW_CFA_def_cfa_offset: 12.
1288 elfcpp::DW_CFA_advance_loc
+ 10, // Advance 10 to __PLT__ + 16.
1289 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
1290 11, // Block length.
1291 elfcpp::DW_OP_breg4
, 4, // Push %esp + 4.
1292 elfcpp::DW_OP_breg8
, 0, // Push %eip.
1293 elfcpp::DW_OP_lit15
, // Push 0xf.
1294 elfcpp::DW_OP_and
, // & (%eip & 0xf).
1295 elfcpp::DW_OP_lit11
, // Push 0xb.
1296 elfcpp::DW_OP_ge
, // >= ((%eip & 0xf) >= 0xb)
1297 elfcpp::DW_OP_lit2
, // Push 2.
1298 elfcpp::DW_OP_shl
, // << (((%eip & 0xf) >= 0xb) << 2)
1299 elfcpp::DW_OP_plus
, // + ((((%eip&0xf)>=0xb)<<2)+%esp+4
1300 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
1306 // Write out the PLT. This uses the hand-coded instructions above,
1307 // and adjusts them as needed. This is all specified by the i386 ELF
1308 // Processor Supplement.
1311 Output_data_plt_i386::do_write(Output_file
* of
)
1313 const off_t offset
= this->offset();
1314 const section_size_type oview_size
=
1315 convert_to_section_size_type(this->data_size());
1316 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
1318 const off_t got_file_offset
= this->got_plt_
->offset();
1319 gold_assert(parameters
->incremental_update()
1320 || (got_file_offset
+ this->got_plt_
->data_size()
1321 == this->got_irelative_
->offset()));
1322 const section_size_type got_size
=
1323 convert_to_section_size_type(this->got_plt_
->data_size()
1324 + this->got_irelative_
->data_size());
1325 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
1328 unsigned char* pov
= oview
;
1330 elfcpp::Elf_types
<32>::Elf_Addr plt_address
= this->address();
1331 elfcpp::Elf_types
<32>::Elf_Addr got_address
= this->got_plt_
->address();
1333 this->fill_first_plt_entry(pov
, got_address
);
1334 pov
+= this->get_plt_entry_size();
1336 unsigned char* got_pov
= got_view
;
1338 // The first entry in the GOT is the address of the .dynamic section
1339 // aka the PT_DYNAMIC segment. The next two entries are reserved.
1340 // We saved space for them when we created the section in
1341 // Target_i386::got_section.
1342 Output_section
* dynamic
= this->layout_
->dynamic_section();
1343 uint32_t dynamic_addr
= dynamic
== NULL
? 0 : dynamic
->address();
1344 elfcpp::Swap
<32, false>::writeval(got_pov
, dynamic_addr
);
1346 memset(got_pov
, 0, 8);
1349 const int rel_size
= elfcpp::Elf_sizes
<32>::rel_size
;
1351 unsigned int plt_offset
= this->get_plt_entry_size();
1352 unsigned int plt_rel_offset
= 0;
1353 unsigned int got_offset
= 12;
1354 const unsigned int count
= this->count_
+ this->irelative_count_
;
1355 for (unsigned int i
= 0;
1358 pov
+= this->get_plt_entry_size(),
1360 plt_offset
+= this->get_plt_entry_size(),
1361 plt_rel_offset
+= rel_size
,
1364 // Set and adjust the PLT entry itself.
1365 unsigned int lazy_offset
= this->fill_plt_entry(pov
,
1371 // Set the entry in the GOT.
1372 elfcpp::Swap
<32, false>::writeval(got_pov
,
1373 plt_address
+ plt_offset
+ lazy_offset
);
1376 // If any STT_GNU_IFUNC symbols have PLT entries, we need to change
1377 // the GOT to point to the actual symbol value, rather than point to
1378 // the PLT entry. That will let the dynamic linker call the right
1379 // function when resolving IRELATIVE relocations.
1380 unsigned char* got_irelative_view
= got_view
+ this->got_plt_
->data_size();
1381 for (std::vector
<Global_ifunc
>::const_iterator p
=
1382 this->global_ifuncs_
.begin();
1383 p
!= this->global_ifuncs_
.end();
1386 const Sized_symbol
<32>* ssym
=
1387 static_cast<const Sized_symbol
<32>*>(p
->sym
);
1388 elfcpp::Swap
<32, false>::writeval(got_irelative_view
+ p
->got_offset
,
1392 for (std::vector
<Local_ifunc
>::const_iterator p
=
1393 this->local_ifuncs_
.begin();
1394 p
!= this->local_ifuncs_
.end();
1397 const Symbol_value
<32>* psymval
=
1398 p
->object
->local_symbol(p
->local_sym_index
);
1399 elfcpp::Swap
<32, false>::writeval(got_irelative_view
+ p
->got_offset
,
1400 psymval
->value(p
->object
, 0));
1403 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
1404 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
1406 of
->write_output_view(offset
, oview_size
, oview
);
1407 of
->write_output_view(got_file_offset
, got_size
, got_view
);
1410 // Create the PLT section.
1413 Target_i386::make_plt_section(Symbol_table
* symtab
, Layout
* layout
)
1415 if (this->plt_
== NULL
)
1417 // Create the GOT sections first.
1418 this->got_section(symtab
, layout
);
1420 const bool dyn
= parameters
->options().output_is_position_independent();
1421 this->plt_
= this->make_data_plt(layout
,
1423 this->got_irelative_
,
1426 // Add unwind information if requested.
1427 if (parameters
->options().ld_generated_unwind_info())
1428 this->plt_
->add_eh_frame(layout
);
1430 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
1432 | elfcpp::SHF_EXECINSTR
),
1433 this->plt_
, ORDER_PLT
, false);
1435 // Make the sh_info field of .rel.plt point to .plt.
1436 Output_section
* rel_plt_os
= this->plt_
->rel_plt()->output_section();
1437 rel_plt_os
->set_info_section(this->plt_
->output_section());
1441 // Create a PLT entry for a global symbol.
1444 Target_i386::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
, Symbol
* gsym
)
1446 if (gsym
->has_plt_offset())
1448 if (this->plt_
== NULL
)
1449 this->make_plt_section(symtab
, layout
);
1450 this->plt_
->add_entry(symtab
, layout
, gsym
);
1453 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1456 Target_i386::make_local_ifunc_plt_entry(Symbol_table
* symtab
, Layout
* layout
,
1457 Sized_relobj_file
<32, false>* relobj
,
1458 unsigned int local_sym_index
)
1460 if (relobj
->local_has_plt_offset(local_sym_index
))
1462 if (this->plt_
== NULL
)
1463 this->make_plt_section(symtab
, layout
);
1464 unsigned int plt_offset
= this->plt_
->add_local_ifunc_entry(symtab
, layout
,
1467 relobj
->set_local_plt_offset(local_sym_index
, plt_offset
);
1470 // Return the number of entries in the PLT.
1473 Target_i386::plt_entry_count() const
1475 if (this->plt_
== NULL
)
1477 return this->plt_
->entry_count();
1480 // Return the offset of the first non-reserved PLT entry.
1483 Target_i386::first_plt_entry_offset() const
1485 return this->plt_
->first_plt_entry_offset();
1488 // Return the size of each PLT entry.
1491 Target_i386::plt_entry_size() const
1493 return this->plt_
->get_plt_entry_size();
1496 // Get the section to use for TLS_DESC relocations.
1498 Target_i386::Reloc_section
*
1499 Target_i386::rel_tls_desc_section(Layout
* layout
) const
1501 return this->plt_section()->rel_tls_desc(layout
);
1504 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1507 Target_i386::define_tls_base_symbol(Symbol_table
* symtab
, Layout
* layout
)
1509 if (this->tls_base_symbol_defined_
)
1512 Output_segment
* tls_segment
= layout
->tls_segment();
1513 if (tls_segment
!= NULL
)
1515 bool is_exec
= parameters
->options().output_is_executable();
1516 symtab
->define_in_output_segment("_TLS_MODULE_BASE_", NULL
,
1517 Symbol_table::PREDEFINED
,
1521 elfcpp::STV_HIDDEN
, 0,
1523 ? Symbol::SEGMENT_END
1524 : Symbol::SEGMENT_START
),
1527 this->tls_base_symbol_defined_
= true;
1530 // Create a GOT entry for the TLS module index.
1533 Target_i386::got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
1534 Sized_relobj_file
<32, false>* object
)
1536 if (this->got_mod_index_offset_
== -1U)
1538 gold_assert(symtab
!= NULL
&& layout
!= NULL
&& object
!= NULL
);
1539 Reloc_section
* rel_dyn
= this->rel_dyn_section(layout
);
1540 Output_data_got
<32, false>* got
= this->got_section(symtab
, layout
);
1541 unsigned int got_offset
= got
->add_constant(0);
1542 rel_dyn
->add_local(object
, 0, elfcpp::R_386_TLS_DTPMOD32
, got
,
1544 got
->add_constant(0);
1545 this->got_mod_index_offset_
= got_offset
;
1547 return this->got_mod_index_offset_
;
1550 // Optimize the TLS relocation type based on what we know about the
1551 // symbol. IS_FINAL is true if the final address of this symbol is
1552 // known at link time.
1554 tls::Tls_optimization
1555 Target_i386::optimize_tls_reloc(bool is_final
, int r_type
)
1557 // If we are generating a shared library, then we can't do anything
1559 if (parameters
->options().shared())
1560 return tls::TLSOPT_NONE
;
1564 case elfcpp::R_386_TLS_GD
:
1565 case elfcpp::R_386_TLS_GOTDESC
:
1566 case elfcpp::R_386_TLS_DESC_CALL
:
1567 // These are General-Dynamic which permits fully general TLS
1568 // access. Since we know that we are generating an executable,
1569 // we can convert this to Initial-Exec. If we also know that
1570 // this is a local symbol, we can further switch to Local-Exec.
1572 return tls::TLSOPT_TO_LE
;
1573 return tls::TLSOPT_TO_IE
;
1575 case elfcpp::R_386_TLS_LDM
:
1576 // This is Local-Dynamic, which refers to a local symbol in the
1577 // dynamic TLS block. Since we know that we generating an
1578 // executable, we can switch to Local-Exec.
1579 return tls::TLSOPT_TO_LE
;
1581 case elfcpp::R_386_TLS_LDO_32
:
1582 // Another type of Local-Dynamic relocation.
1583 return tls::TLSOPT_TO_LE
;
1585 case elfcpp::R_386_TLS_IE
:
1586 case elfcpp::R_386_TLS_GOTIE
:
1587 case elfcpp::R_386_TLS_IE_32
:
1588 // These are Initial-Exec relocs which get the thread offset
1589 // from the GOT. If we know that we are linking against the
1590 // local symbol, we can switch to Local-Exec, which links the
1591 // thread offset into the instruction.
1593 return tls::TLSOPT_TO_LE
;
1594 return tls::TLSOPT_NONE
;
1596 case elfcpp::R_386_TLS_LE
:
1597 case elfcpp::R_386_TLS_LE_32
:
1598 // When we already have Local-Exec, there is nothing further we
1600 return tls::TLSOPT_NONE
;
1607 // Get the Reference_flags for a particular relocation.
1610 Target_i386::Scan::get_reference_flags(unsigned int r_type
)
1614 case elfcpp::R_386_NONE
:
1615 case elfcpp::R_386_GNU_VTINHERIT
:
1616 case elfcpp::R_386_GNU_VTENTRY
:
1617 case elfcpp::R_386_GOTPC
:
1618 // No symbol reference.
1621 case elfcpp::R_386_32
:
1622 case elfcpp::R_386_16
:
1623 case elfcpp::R_386_8
:
1624 return Symbol::ABSOLUTE_REF
;
1626 case elfcpp::R_386_PC32
:
1627 case elfcpp::R_386_PC16
:
1628 case elfcpp::R_386_PC8
:
1629 case elfcpp::R_386_GOTOFF
:
1630 return Symbol::RELATIVE_REF
;
1632 case elfcpp::R_386_PLT32
:
1633 return Symbol::FUNCTION_CALL
| Symbol::RELATIVE_REF
;
1635 case elfcpp::R_386_GOT32
:
1637 return Symbol::ABSOLUTE_REF
;
1639 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1640 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1641 case elfcpp::R_386_TLS_DESC_CALL
:
1642 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1643 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1644 case elfcpp::R_386_TLS_IE
: // Initial-exec
1645 case elfcpp::R_386_TLS_IE_32
:
1646 case elfcpp::R_386_TLS_GOTIE
:
1647 case elfcpp::R_386_TLS_LE
: // Local-exec
1648 case elfcpp::R_386_TLS_LE_32
:
1649 return Symbol::TLS_REF
;
1651 case elfcpp::R_386_COPY
:
1652 case elfcpp::R_386_GLOB_DAT
:
1653 case elfcpp::R_386_JUMP_SLOT
:
1654 case elfcpp::R_386_RELATIVE
:
1655 case elfcpp::R_386_IRELATIVE
:
1656 case elfcpp::R_386_TLS_TPOFF
:
1657 case elfcpp::R_386_TLS_DTPMOD32
:
1658 case elfcpp::R_386_TLS_DTPOFF32
:
1659 case elfcpp::R_386_TLS_TPOFF32
:
1660 case elfcpp::R_386_TLS_DESC
:
1661 case elfcpp::R_386_32PLT
:
1662 case elfcpp::R_386_TLS_GD_32
:
1663 case elfcpp::R_386_TLS_GD_PUSH
:
1664 case elfcpp::R_386_TLS_GD_CALL
:
1665 case elfcpp::R_386_TLS_GD_POP
:
1666 case elfcpp::R_386_TLS_LDM_32
:
1667 case elfcpp::R_386_TLS_LDM_PUSH
:
1668 case elfcpp::R_386_TLS_LDM_CALL
:
1669 case elfcpp::R_386_TLS_LDM_POP
:
1670 case elfcpp::R_386_USED_BY_INTEL_200
:
1672 // Not expected. We will give an error later.
1677 // Report an unsupported relocation against a local symbol.
1680 Target_i386::Scan::unsupported_reloc_local(Sized_relobj_file
<32, false>* object
,
1681 unsigned int r_type
)
1683 gold_error(_("%s: unsupported reloc %u against local symbol"),
1684 object
->name().c_str(), r_type
);
1687 // Return whether we need to make a PLT entry for a relocation of a
1688 // given type against a STT_GNU_IFUNC symbol.
1691 Target_i386::Scan::reloc_needs_plt_for_ifunc(
1692 Sized_relobj_file
<32, false>* object
,
1693 unsigned int r_type
)
1695 int flags
= Scan::get_reference_flags(r_type
);
1696 if (flags
& Symbol::TLS_REF
)
1697 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
1698 object
->name().c_str(), r_type
);
1702 // Scan a relocation for a local symbol.
1705 Target_i386::Scan::local(Symbol_table
* symtab
,
1707 Target_i386
* target
,
1708 Sized_relobj_file
<32, false>* object
,
1709 unsigned int data_shndx
,
1710 Output_section
* output_section
,
1711 const elfcpp::Rel
<32, false>& reloc
,
1712 unsigned int r_type
,
1713 const elfcpp::Sym
<32, false>& lsym
,
1719 // A local STT_GNU_IFUNC symbol may require a PLT entry.
1720 if (lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
1721 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
1723 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1724 target
->make_local_ifunc_plt_entry(symtab
, layout
, object
, r_sym
);
1729 case elfcpp::R_386_NONE
:
1730 case elfcpp::R_386_GNU_VTINHERIT
:
1731 case elfcpp::R_386_GNU_VTENTRY
:
1734 case elfcpp::R_386_32
:
1735 // If building a shared library (or a position-independent
1736 // executable), we need to create a dynamic relocation for
1737 // this location. The relocation applied at link time will
1738 // apply the link-time value, so we flag the location with
1739 // an R_386_RELATIVE relocation so the dynamic loader can
1740 // relocate it easily.
1741 if (parameters
->options().output_is_position_independent())
1743 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1744 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1745 rel_dyn
->add_local_relative(object
, r_sym
, elfcpp::R_386_RELATIVE
,
1746 output_section
, data_shndx
,
1747 reloc
.get_r_offset());
1751 case elfcpp::R_386_16
:
1752 case elfcpp::R_386_8
:
1753 // If building a shared library (or a position-independent
1754 // executable), we need to create a dynamic relocation for
1755 // this location. Because the addend needs to remain in the
1756 // data section, we need to be careful not to apply this
1757 // relocation statically.
1758 if (parameters
->options().output_is_position_independent())
1760 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1761 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1762 if (lsym
.get_st_type() != elfcpp::STT_SECTION
)
1763 rel_dyn
->add_local(object
, r_sym
, r_type
, output_section
,
1764 data_shndx
, reloc
.get_r_offset());
1767 gold_assert(lsym
.get_st_value() == 0);
1768 unsigned int shndx
= lsym
.get_st_shndx();
1770 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
,
1773 object
->error(_("section symbol %u has bad shndx %u"),
1776 rel_dyn
->add_local_section(object
, shndx
,
1777 r_type
, output_section
,
1778 data_shndx
, reloc
.get_r_offset());
1783 case elfcpp::R_386_PC32
:
1784 case elfcpp::R_386_PC16
:
1785 case elfcpp::R_386_PC8
:
1788 case elfcpp::R_386_PLT32
:
1789 // Since we know this is a local symbol, we can handle this as a
1793 case elfcpp::R_386_GOTOFF
:
1794 case elfcpp::R_386_GOTPC
:
1795 // We need a GOT section.
1796 target
->got_section(symtab
, layout
);
1799 case elfcpp::R_386_GOT32
:
1801 // The symbol requires a GOT entry.
1802 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
1803 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1805 // For a STT_GNU_IFUNC symbol we want the PLT offset. That
1806 // lets function pointers compare correctly with shared
1807 // libraries. Otherwise we would need an IRELATIVE reloc.
1809 if (lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
)
1810 is_new
= got
->add_local_plt(object
, r_sym
, GOT_TYPE_STANDARD
);
1812 is_new
= got
->add_local(object
, r_sym
, GOT_TYPE_STANDARD
);
1815 // If we are generating a shared object, we need to add a
1816 // dynamic RELATIVE relocation for this symbol's GOT entry.
1817 if (parameters
->options().output_is_position_independent())
1819 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1820 unsigned int got_offset
=
1821 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
);
1822 rel_dyn
->add_local_relative(object
, r_sym
,
1823 elfcpp::R_386_RELATIVE
,
1830 // These are relocations which should only be seen by the
1831 // dynamic linker, and should never be seen here.
1832 case elfcpp::R_386_COPY
:
1833 case elfcpp::R_386_GLOB_DAT
:
1834 case elfcpp::R_386_JUMP_SLOT
:
1835 case elfcpp::R_386_RELATIVE
:
1836 case elfcpp::R_386_IRELATIVE
:
1837 case elfcpp::R_386_TLS_TPOFF
:
1838 case elfcpp::R_386_TLS_DTPMOD32
:
1839 case elfcpp::R_386_TLS_DTPOFF32
:
1840 case elfcpp::R_386_TLS_TPOFF32
:
1841 case elfcpp::R_386_TLS_DESC
:
1842 gold_error(_("%s: unexpected reloc %u in object file"),
1843 object
->name().c_str(), r_type
);
1846 // These are initial TLS relocs, which are expected when
1848 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1849 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1850 case elfcpp::R_386_TLS_DESC_CALL
:
1851 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1852 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1853 case elfcpp::R_386_TLS_IE
: // Initial-exec
1854 case elfcpp::R_386_TLS_IE_32
:
1855 case elfcpp::R_386_TLS_GOTIE
:
1856 case elfcpp::R_386_TLS_LE
: // Local-exec
1857 case elfcpp::R_386_TLS_LE_32
:
1859 bool output_is_shared
= parameters
->options().shared();
1860 const tls::Tls_optimization optimized_type
1861 = Target_i386::optimize_tls_reloc(!output_is_shared
, r_type
);
1864 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1865 if (optimized_type
== tls::TLSOPT_NONE
)
1867 // Create a pair of GOT entries for the module index and
1868 // dtv-relative offset.
1869 Output_data_got
<32, false>* got
1870 = target
->got_section(symtab
, layout
);
1871 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1872 unsigned int shndx
= lsym
.get_st_shndx();
1874 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
1876 object
->error(_("local symbol %u has bad shndx %u"),
1879 got
->add_local_pair_with_rel(object
, r_sym
, shndx
,
1881 target
->rel_dyn_section(layout
),
1882 elfcpp::R_386_TLS_DTPMOD32
);
1884 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1885 unsupported_reloc_local(object
, r_type
);
1888 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva)
1889 target
->define_tls_base_symbol(symtab
, layout
);
1890 if (optimized_type
== tls::TLSOPT_NONE
)
1892 // Create a double GOT entry with an R_386_TLS_DESC
1893 // reloc. The R_386_TLS_DESC reloc is resolved
1894 // lazily, so the GOT entry needs to be in an area in
1895 // .got.plt, not .got. Call got_section to make sure
1896 // the section has been created.
1897 target
->got_section(symtab
, layout
);
1898 Output_data_got
<32, false>* got
= target
->got_tlsdesc_section();
1899 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1900 if (!object
->local_has_got_offset(r_sym
, GOT_TYPE_TLS_DESC
))
1902 unsigned int got_offset
= got
->add_constant(0);
1903 // The local symbol value is stored in the second
1905 got
->add_local(object
, r_sym
, GOT_TYPE_TLS_DESC
);
1906 // That set the GOT offset of the local symbol to
1907 // point to the second entry, but we want it to
1908 // point to the first.
1909 object
->set_local_got_offset(r_sym
, GOT_TYPE_TLS_DESC
,
1911 Reloc_section
* rt
= target
->rel_tls_desc_section(layout
);
1912 rt
->add_absolute(elfcpp::R_386_TLS_DESC
, got
, got_offset
);
1915 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1916 unsupported_reloc_local(object
, r_type
);
1919 case elfcpp::R_386_TLS_DESC_CALL
:
1922 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1923 if (optimized_type
== tls::TLSOPT_NONE
)
1925 // Create a GOT entry for the module index.
1926 target
->got_mod_index_entry(symtab
, layout
, object
);
1928 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1929 unsupported_reloc_local(object
, r_type
);
1932 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1935 case elfcpp::R_386_TLS_IE
: // Initial-exec
1936 case elfcpp::R_386_TLS_IE_32
:
1937 case elfcpp::R_386_TLS_GOTIE
:
1938 layout
->set_has_static_tls();
1939 if (optimized_type
== tls::TLSOPT_NONE
)
1941 // For the R_386_TLS_IE relocation, we need to create a
1942 // dynamic relocation when building a shared library.
1943 if (r_type
== elfcpp::R_386_TLS_IE
1944 && parameters
->options().shared())
1946 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1948 = elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1949 rel_dyn
->add_local_relative(object
, r_sym
,
1950 elfcpp::R_386_RELATIVE
,
1951 output_section
, data_shndx
,
1952 reloc
.get_r_offset());
1954 // Create a GOT entry for the tp-relative offset.
1955 Output_data_got
<32, false>* got
1956 = target
->got_section(symtab
, layout
);
1957 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1958 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1959 ? elfcpp::R_386_TLS_TPOFF32
1960 : elfcpp::R_386_TLS_TPOFF
);
1961 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1962 ? GOT_TYPE_TLS_OFFSET
1963 : GOT_TYPE_TLS_NOFFSET
);
1964 got
->add_local_with_rel(object
, r_sym
, got_type
,
1965 target
->rel_dyn_section(layout
),
1968 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1969 unsupported_reloc_local(object
, r_type
);
1972 case elfcpp::R_386_TLS_LE
: // Local-exec
1973 case elfcpp::R_386_TLS_LE_32
:
1974 layout
->set_has_static_tls();
1975 if (output_is_shared
)
1977 // We need to create a dynamic relocation.
1978 gold_assert(lsym
.get_st_type() != elfcpp::STT_SECTION
);
1979 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1980 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
1981 ? elfcpp::R_386_TLS_TPOFF32
1982 : elfcpp::R_386_TLS_TPOFF
);
1983 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1984 rel_dyn
->add_local(object
, r_sym
, dyn_r_type
, output_section
,
1985 data_shndx
, reloc
.get_r_offset());
1995 case elfcpp::R_386_32PLT
:
1996 case elfcpp::R_386_TLS_GD_32
:
1997 case elfcpp::R_386_TLS_GD_PUSH
:
1998 case elfcpp::R_386_TLS_GD_CALL
:
1999 case elfcpp::R_386_TLS_GD_POP
:
2000 case elfcpp::R_386_TLS_LDM_32
:
2001 case elfcpp::R_386_TLS_LDM_PUSH
:
2002 case elfcpp::R_386_TLS_LDM_CALL
:
2003 case elfcpp::R_386_TLS_LDM_POP
:
2004 case elfcpp::R_386_USED_BY_INTEL_200
:
2006 unsupported_reloc_local(object
, r_type
);
2011 // Report an unsupported relocation against a global symbol.
2014 Target_i386::Scan::unsupported_reloc_global(
2015 Sized_relobj_file
<32, false>* object
,
2016 unsigned int r_type
,
2019 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
2020 object
->name().c_str(), r_type
, gsym
->demangled_name().c_str());
2024 Target_i386::Scan::possible_function_pointer_reloc(unsigned int r_type
)
2028 case elfcpp::R_386_32
:
2029 case elfcpp::R_386_16
:
2030 case elfcpp::R_386_8
:
2031 case elfcpp::R_386_GOTOFF
:
2032 case elfcpp::R_386_GOT32
:
2043 Target_i386::Scan::local_reloc_may_be_function_pointer(
2047 Sized_relobj_file
<32, false>* ,
2050 const elfcpp::Rel
<32, false>& ,
2051 unsigned int r_type
,
2052 const elfcpp::Sym
<32, false>&)
2054 return possible_function_pointer_reloc(r_type
);
2058 Target_i386::Scan::global_reloc_may_be_function_pointer(
2062 Sized_relobj_file
<32, false>* ,
2065 const elfcpp::Rel
<32, false>& ,
2066 unsigned int r_type
,
2069 return possible_function_pointer_reloc(r_type
);
2072 // Scan a relocation for a global symbol.
2075 Target_i386::Scan::global(Symbol_table
* symtab
,
2077 Target_i386
* target
,
2078 Sized_relobj_file
<32, false>* object
,
2079 unsigned int data_shndx
,
2080 Output_section
* output_section
,
2081 const elfcpp::Rel
<32, false>& reloc
,
2082 unsigned int r_type
,
2085 // A STT_GNU_IFUNC symbol may require a PLT entry.
2086 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
2087 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
2088 target
->make_plt_entry(symtab
, layout
, gsym
);
2092 case elfcpp::R_386_NONE
:
2093 case elfcpp::R_386_GNU_VTINHERIT
:
2094 case elfcpp::R_386_GNU_VTENTRY
:
2097 case elfcpp::R_386_32
:
2098 case elfcpp::R_386_16
:
2099 case elfcpp::R_386_8
:
2101 // Make a PLT entry if necessary.
2102 if (gsym
->needs_plt_entry())
2104 target
->make_plt_entry(symtab
, layout
, gsym
);
2105 // Since this is not a PC-relative relocation, we may be
2106 // taking the address of a function. In that case we need to
2107 // set the entry in the dynamic symbol table to the address of
2109 if (gsym
->is_from_dynobj() && !parameters
->options().shared())
2110 gsym
->set_needs_dynsym_value();
2112 // Make a dynamic relocation if necessary.
2113 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
2115 if (gsym
->may_need_copy_reloc())
2117 target
->copy_reloc(symtab
, layout
, object
,
2118 data_shndx
, output_section
, gsym
, reloc
);
2120 else if (r_type
== elfcpp::R_386_32
2121 && gsym
->type() == elfcpp::STT_GNU_IFUNC
2122 && gsym
->can_use_relative_reloc(false)
2123 && !gsym
->is_from_dynobj()
2124 && !gsym
->is_undefined()
2125 && !gsym
->is_preemptible())
2127 // Use an IRELATIVE reloc for a locally defined
2128 // STT_GNU_IFUNC symbol. This makes a function
2129 // address in a PIE executable match the address in a
2130 // shared library that it links against.
2131 Reloc_section
* rel_dyn
= target
->rel_irelative_section(layout
);
2132 rel_dyn
->add_symbolless_global_addend(gsym
,
2133 elfcpp::R_386_IRELATIVE
,
2136 reloc
.get_r_offset());
2138 else if (r_type
== elfcpp::R_386_32
2139 && gsym
->can_use_relative_reloc(false))
2141 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2142 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
2143 output_section
, object
,
2144 data_shndx
, reloc
.get_r_offset());
2148 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2149 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
2150 data_shndx
, reloc
.get_r_offset());
2156 case elfcpp::R_386_PC32
:
2157 case elfcpp::R_386_PC16
:
2158 case elfcpp::R_386_PC8
:
2160 // Make a PLT entry if necessary.
2161 if (gsym
->needs_plt_entry())
2163 // These relocations are used for function calls only in
2164 // non-PIC code. For a 32-bit relocation in a shared library,
2165 // we'll need a text relocation anyway, so we can skip the
2166 // PLT entry and let the dynamic linker bind the call directly
2167 // to the target. For smaller relocations, we should use a
2168 // PLT entry to ensure that the call can reach.
2169 if (!parameters
->options().shared()
2170 || r_type
!= elfcpp::R_386_PC32
)
2171 target
->make_plt_entry(symtab
, layout
, gsym
);
2173 // Make a dynamic relocation if necessary.
2174 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
2176 if (gsym
->may_need_copy_reloc())
2178 target
->copy_reloc(symtab
, layout
, object
,
2179 data_shndx
, output_section
, gsym
, reloc
);
2183 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2184 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
2185 data_shndx
, reloc
.get_r_offset());
2191 case elfcpp::R_386_GOT32
:
2193 // The symbol requires a GOT entry.
2194 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
2195 if (gsym
->final_value_is_known())
2197 // For a STT_GNU_IFUNC symbol we want the PLT address.
2198 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
)
2199 got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
2201 got
->add_global(gsym
, GOT_TYPE_STANDARD
);
2205 // If this symbol is not fully resolved, we need to add a
2206 // GOT entry with a dynamic relocation.
2207 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2209 // Use a GLOB_DAT rather than a RELATIVE reloc if:
2211 // 1) The symbol may be defined in some other module.
2213 // 2) We are building a shared library and this is a
2214 // protected symbol; using GLOB_DAT means that the dynamic
2215 // linker can use the address of the PLT in the main
2216 // executable when appropriate so that function address
2217 // comparisons work.
2219 // 3) This is a STT_GNU_IFUNC symbol in position dependent
2220 // code, again so that function address comparisons work.
2221 if (gsym
->is_from_dynobj()
2222 || gsym
->is_undefined()
2223 || gsym
->is_preemptible()
2224 || (gsym
->visibility() == elfcpp::STV_PROTECTED
2225 && parameters
->options().shared())
2226 || (gsym
->type() == elfcpp::STT_GNU_IFUNC
2227 && parameters
->options().output_is_position_independent()))
2228 got
->add_global_with_rel(gsym
, GOT_TYPE_STANDARD
,
2229 rel_dyn
, elfcpp::R_386_GLOB_DAT
);
2232 // For a STT_GNU_IFUNC symbol we want to write the PLT
2233 // offset into the GOT, so that function pointer
2234 // comparisons work correctly.
2236 if (gsym
->type() != elfcpp::STT_GNU_IFUNC
)
2237 is_new
= got
->add_global(gsym
, GOT_TYPE_STANDARD
);
2240 is_new
= got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
2241 // Tell the dynamic linker to use the PLT address
2242 // when resolving relocations.
2243 if (gsym
->is_from_dynobj()
2244 && !parameters
->options().shared())
2245 gsym
->set_needs_dynsym_value();
2249 unsigned int got_off
= gsym
->got_offset(GOT_TYPE_STANDARD
);
2250 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
2258 case elfcpp::R_386_PLT32
:
2259 // If the symbol is fully resolved, this is just a PC32 reloc.
2260 // Otherwise we need a PLT entry.
2261 if (gsym
->final_value_is_known())
2263 // If building a shared library, we can also skip the PLT entry
2264 // if the symbol is defined in the output file and is protected
2266 if (gsym
->is_defined()
2267 && !gsym
->is_from_dynobj()
2268 && !gsym
->is_preemptible())
2270 target
->make_plt_entry(symtab
, layout
, gsym
);
2273 case elfcpp::R_386_GOTOFF
:
2274 case elfcpp::R_386_GOTPC
:
2275 // We need a GOT section.
2276 target
->got_section(symtab
, layout
);
2279 // These are relocations which should only be seen by the
2280 // dynamic linker, and should never be seen here.
2281 case elfcpp::R_386_COPY
:
2282 case elfcpp::R_386_GLOB_DAT
:
2283 case elfcpp::R_386_JUMP_SLOT
:
2284 case elfcpp::R_386_RELATIVE
:
2285 case elfcpp::R_386_IRELATIVE
:
2286 case elfcpp::R_386_TLS_TPOFF
:
2287 case elfcpp::R_386_TLS_DTPMOD32
:
2288 case elfcpp::R_386_TLS_DTPOFF32
:
2289 case elfcpp::R_386_TLS_TPOFF32
:
2290 case elfcpp::R_386_TLS_DESC
:
2291 gold_error(_("%s: unexpected reloc %u in object file"),
2292 object
->name().c_str(), r_type
);
2295 // These are initial tls relocs, which are expected when
2297 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2298 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2299 case elfcpp::R_386_TLS_DESC_CALL
:
2300 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2301 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2302 case elfcpp::R_386_TLS_IE
: // Initial-exec
2303 case elfcpp::R_386_TLS_IE_32
:
2304 case elfcpp::R_386_TLS_GOTIE
:
2305 case elfcpp::R_386_TLS_LE
: // Local-exec
2306 case elfcpp::R_386_TLS_LE_32
:
2308 const bool is_final
= gsym
->final_value_is_known();
2309 const tls::Tls_optimization optimized_type
2310 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
2313 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2314 if (optimized_type
== tls::TLSOPT_NONE
)
2316 // Create a pair of GOT entries for the module index and
2317 // dtv-relative offset.
2318 Output_data_got
<32, false>* got
2319 = target
->got_section(symtab
, layout
);
2320 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_PAIR
,
2321 target
->rel_dyn_section(layout
),
2322 elfcpp::R_386_TLS_DTPMOD32
,
2323 elfcpp::R_386_TLS_DTPOFF32
);
2325 else if (optimized_type
== tls::TLSOPT_TO_IE
)
2327 // Create a GOT entry for the tp-relative offset.
2328 Output_data_got
<32, false>* got
2329 = target
->got_section(symtab
, layout
);
2330 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
2331 target
->rel_dyn_section(layout
),
2332 elfcpp::R_386_TLS_TPOFF
);
2334 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2335 unsupported_reloc_global(object
, r_type
, gsym
);
2338 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (~oliva url)
2339 target
->define_tls_base_symbol(symtab
, layout
);
2340 if (optimized_type
== tls::TLSOPT_NONE
)
2342 // Create a double GOT entry with an R_386_TLS_DESC
2343 // reloc. The R_386_TLS_DESC reloc is resolved
2344 // lazily, so the GOT entry needs to be in an area in
2345 // .got.plt, not .got. Call got_section to make sure
2346 // the section has been created.
2347 target
->got_section(symtab
, layout
);
2348 Output_data_got
<32, false>* got
= target
->got_tlsdesc_section();
2349 Reloc_section
* rt
= target
->rel_tls_desc_section(layout
);
2350 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_DESC
, rt
,
2351 elfcpp::R_386_TLS_DESC
, 0);
2353 else if (optimized_type
== tls::TLSOPT_TO_IE
)
2355 // Create a GOT entry for the tp-relative offset.
2356 Output_data_got
<32, false>* got
2357 = target
->got_section(symtab
, layout
);
2358 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
2359 target
->rel_dyn_section(layout
),
2360 elfcpp::R_386_TLS_TPOFF
);
2362 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2363 unsupported_reloc_global(object
, r_type
, gsym
);
2366 case elfcpp::R_386_TLS_DESC_CALL
:
2369 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2370 if (optimized_type
== tls::TLSOPT_NONE
)
2372 // Create a GOT entry for the module index.
2373 target
->got_mod_index_entry(symtab
, layout
, object
);
2375 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2376 unsupported_reloc_global(object
, r_type
, gsym
);
2379 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2382 case elfcpp::R_386_TLS_IE
: // Initial-exec
2383 case elfcpp::R_386_TLS_IE_32
:
2384 case elfcpp::R_386_TLS_GOTIE
:
2385 layout
->set_has_static_tls();
2386 if (optimized_type
== tls::TLSOPT_NONE
)
2388 // For the R_386_TLS_IE relocation, we need to create a
2389 // dynamic relocation when building a shared library.
2390 if (r_type
== elfcpp::R_386_TLS_IE
2391 && parameters
->options().shared())
2393 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2394 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
2395 output_section
, object
,
2397 reloc
.get_r_offset());
2399 // Create a GOT entry for the tp-relative offset.
2400 Output_data_got
<32, false>* got
2401 = target
->got_section(symtab
, layout
);
2402 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2403 ? elfcpp::R_386_TLS_TPOFF32
2404 : elfcpp::R_386_TLS_TPOFF
);
2405 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2406 ? GOT_TYPE_TLS_OFFSET
2407 : GOT_TYPE_TLS_NOFFSET
);
2408 got
->add_global_with_rel(gsym
, got_type
,
2409 target
->rel_dyn_section(layout
),
2412 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2413 unsupported_reloc_global(object
, r_type
, gsym
);
2416 case elfcpp::R_386_TLS_LE
: // Local-exec
2417 case elfcpp::R_386_TLS_LE_32
:
2418 layout
->set_has_static_tls();
2419 if (parameters
->options().shared())
2421 // We need to create a dynamic relocation.
2422 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
2423 ? elfcpp::R_386_TLS_TPOFF32
2424 : elfcpp::R_386_TLS_TPOFF
);
2425 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2426 rel_dyn
->add_global(gsym
, dyn_r_type
, output_section
, object
,
2427 data_shndx
, reloc
.get_r_offset());
2437 case elfcpp::R_386_32PLT
:
2438 case elfcpp::R_386_TLS_GD_32
:
2439 case elfcpp::R_386_TLS_GD_PUSH
:
2440 case elfcpp::R_386_TLS_GD_CALL
:
2441 case elfcpp::R_386_TLS_GD_POP
:
2442 case elfcpp::R_386_TLS_LDM_32
:
2443 case elfcpp::R_386_TLS_LDM_PUSH
:
2444 case elfcpp::R_386_TLS_LDM_CALL
:
2445 case elfcpp::R_386_TLS_LDM_POP
:
2446 case elfcpp::R_386_USED_BY_INTEL_200
:
2448 unsupported_reloc_global(object
, r_type
, gsym
);
2453 // Process relocations for gc.
2456 Target_i386::gc_process_relocs(Symbol_table
* symtab
,
2458 Sized_relobj_file
<32, false>* object
,
2459 unsigned int data_shndx
,
2461 const unsigned char* prelocs
,
2463 Output_section
* output_section
,
2464 bool needs_special_offset_handling
,
2465 size_t local_symbol_count
,
2466 const unsigned char* plocal_symbols
)
2468 gold::gc_process_relocs
<32, false, Target_i386
, elfcpp::SHT_REL
,
2470 Target_i386::Relocatable_size_for_reloc
>(
2479 needs_special_offset_handling
,
2484 // Scan relocations for a section.
2487 Target_i386::scan_relocs(Symbol_table
* symtab
,
2489 Sized_relobj_file
<32, false>* object
,
2490 unsigned int data_shndx
,
2491 unsigned int sh_type
,
2492 const unsigned char* prelocs
,
2494 Output_section
* output_section
,
2495 bool needs_special_offset_handling
,
2496 size_t local_symbol_count
,
2497 const unsigned char* plocal_symbols
)
2499 if (sh_type
== elfcpp::SHT_RELA
)
2501 gold_error(_("%s: unsupported RELA reloc section"),
2502 object
->name().c_str());
2506 gold::scan_relocs
<32, false, Target_i386
, elfcpp::SHT_REL
,
2516 needs_special_offset_handling
,
2521 // Finalize the sections.
2524 Target_i386::do_finalize_sections(
2526 const Input_objects
*,
2527 Symbol_table
* symtab
)
2529 const Reloc_section
* rel_plt
= (this->plt_
== NULL
2531 : this->plt_
->rel_plt());
2532 layout
->add_target_dynamic_tags(true, this->got_plt_
, rel_plt
,
2533 this->rel_dyn_
, true, false);
2535 // Emit any relocs we saved in an attempt to avoid generating COPY
2537 if (this->copy_relocs_
.any_saved_relocs())
2538 this->copy_relocs_
.emit(this->rel_dyn_section(layout
));
2540 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
2541 // the .got.plt section.
2542 Symbol
* sym
= this->global_offset_table_
;
2545 uint32_t data_size
= this->got_plt_
->current_data_size();
2546 symtab
->get_sized_symbol
<32>(sym
)->set_symsize(data_size
);
2549 if (parameters
->doing_static_link()
2550 && (this->plt_
== NULL
|| !this->plt_
->has_irelative_section()))
2552 // If linking statically, make sure that the __rel_iplt symbols
2553 // were defined if necessary, even if we didn't create a PLT.
2554 static const Define_symbol_in_segment syms
[] =
2557 "__rel_iplt_start", // name
2558 elfcpp::PT_LOAD
, // segment_type
2559 elfcpp::PF_W
, // segment_flags_set
2560 elfcpp::PF(0), // segment_flags_clear
2563 elfcpp::STT_NOTYPE
, // type
2564 elfcpp::STB_GLOBAL
, // binding
2565 elfcpp::STV_HIDDEN
, // visibility
2567 Symbol::SEGMENT_START
, // offset_from_base
2571 "__rel_iplt_end", // name
2572 elfcpp::PT_LOAD
, // segment_type
2573 elfcpp::PF_W
, // segment_flags_set
2574 elfcpp::PF(0), // segment_flags_clear
2577 elfcpp::STT_NOTYPE
, // type
2578 elfcpp::STB_GLOBAL
, // binding
2579 elfcpp::STV_HIDDEN
, // visibility
2581 Symbol::SEGMENT_START
, // offset_from_base
2586 symtab
->define_symbols(layout
, 2, syms
,
2587 layout
->script_options()->saw_sections_clause());
2591 // Return whether a direct absolute static relocation needs to be applied.
2592 // In cases where Scan::local() or Scan::global() has created
2593 // a dynamic relocation other than R_386_RELATIVE, the addend
2594 // of the relocation is carried in the data, and we must not
2595 // apply the static relocation.
2598 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
2599 unsigned int r_type
,
2601 Output_section
* output_section
)
2603 // If the output section is not allocated, then we didn't call
2604 // scan_relocs, we didn't create a dynamic reloc, and we must apply
2606 if ((output_section
->flags() & elfcpp::SHF_ALLOC
) == 0)
2609 int ref_flags
= Scan::get_reference_flags(r_type
);
2611 // For local symbols, we will have created a non-RELATIVE dynamic
2612 // relocation only if (a) the output is position independent,
2613 // (b) the relocation is absolute (not pc- or segment-relative), and
2614 // (c) the relocation is not 32 bits wide.
2616 return !(parameters
->options().output_is_position_independent()
2617 && (ref_flags
& Symbol::ABSOLUTE_REF
)
2620 // For global symbols, we use the same helper routines used in the
2621 // scan pass. If we did not create a dynamic relocation, or if we
2622 // created a RELATIVE dynamic relocation, we should apply the static
2624 bool has_dyn
= gsym
->needs_dynamic_reloc(ref_flags
);
2625 bool is_rel
= (ref_flags
& Symbol::ABSOLUTE_REF
)
2626 && gsym
->can_use_relative_reloc(ref_flags
2627 & Symbol::FUNCTION_CALL
);
2628 return !has_dyn
|| is_rel
;
2631 // Perform a relocation.
2634 Target_i386::Relocate::relocate(const Relocate_info
<32, false>* relinfo
,
2635 Target_i386
* target
,
2636 Output_section
* output_section
,
2638 const elfcpp::Rel
<32, false>& rel
,
2639 unsigned int r_type
,
2640 const Sized_symbol
<32>* gsym
,
2641 const Symbol_value
<32>* psymval
,
2642 unsigned char* view
,
2643 elfcpp::Elf_types
<32>::Elf_Addr address
,
2644 section_size_type view_size
)
2646 if (this->skip_call_tls_get_addr_
)
2648 if ((r_type
!= elfcpp::R_386_PLT32
2649 && r_type
!= elfcpp::R_386_PC32
)
2651 || strcmp(gsym
->name(), "___tls_get_addr") != 0)
2652 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2653 _("missing expected TLS relocation"));
2656 this->skip_call_tls_get_addr_
= false;
2661 const Sized_relobj_file
<32, false>* object
= relinfo
->object
;
2663 // Pick the value to use for symbols defined in shared objects.
2664 Symbol_value
<32> symval
;
2666 && gsym
->type() == elfcpp::STT_GNU_IFUNC
2667 && r_type
== elfcpp::R_386_32
2668 && gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
))
2669 && gsym
->can_use_relative_reloc(false)
2670 && !gsym
->is_from_dynobj()
2671 && !gsym
->is_undefined()
2672 && !gsym
->is_preemptible())
2674 // In this case we are generating a R_386_IRELATIVE reloc. We
2675 // want to use the real value of the symbol, not the PLT offset.
2677 else if (gsym
!= NULL
2678 && gsym
->use_plt_offset(Scan::get_reference_flags(r_type
)))
2680 symval
.set_output_value(target
->plt_address_for_global(gsym
)
2681 + gsym
->plt_offset());
2684 else if (gsym
== NULL
&& psymval
->is_ifunc_symbol())
2686 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2687 if (object
->local_has_plt_offset(r_sym
))
2689 symval
.set_output_value(target
->plt_address_for_local(object
, r_sym
)
2690 + object
->local_plt_offset(r_sym
));
2695 // Get the GOT offset if needed.
2696 // The GOT pointer points to the end of the GOT section.
2697 // We need to subtract the size of the GOT section to get
2698 // the actual offset to use in the relocation.
2699 bool have_got_offset
= false;
2700 unsigned int got_offset
= 0;
2703 case elfcpp::R_386_GOT32
:
2706 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
2707 got_offset
= (gsym
->got_offset(GOT_TYPE_STANDARD
)
2708 - target
->got_size());
2712 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2713 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
2714 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
2715 - target
->got_size());
2717 have_got_offset
= true;
2726 case elfcpp::R_386_NONE
:
2727 case elfcpp::R_386_GNU_VTINHERIT
:
2728 case elfcpp::R_386_GNU_VTENTRY
:
2731 case elfcpp::R_386_32
:
2732 if (should_apply_static_reloc(gsym
, r_type
, true, output_section
))
2733 Relocate_functions
<32, false>::rel32(view
, object
, psymval
);
2736 case elfcpp::R_386_PC32
:
2737 if (should_apply_static_reloc(gsym
, r_type
, true, output_section
))
2738 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
2741 case elfcpp::R_386_16
:
2742 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2743 Relocate_functions
<32, false>::rel16(view
, object
, psymval
);
2746 case elfcpp::R_386_PC16
:
2747 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2748 Relocate_functions
<32, false>::pcrel16(view
, object
, psymval
, address
);
2751 case elfcpp::R_386_8
:
2752 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2753 Relocate_functions
<32, false>::rel8(view
, object
, psymval
);
2756 case elfcpp::R_386_PC8
:
2757 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2758 Relocate_functions
<32, false>::pcrel8(view
, object
, psymval
, address
);
2761 case elfcpp::R_386_PLT32
:
2762 gold_assert(gsym
== NULL
2763 || gsym
->has_plt_offset()
2764 || gsym
->final_value_is_known()
2765 || (gsym
->is_defined()
2766 && !gsym
->is_from_dynobj()
2767 && !gsym
->is_preemptible()));
2768 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
2771 case elfcpp::R_386_GOT32
:
2772 gold_assert(have_got_offset
);
2773 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2776 case elfcpp::R_386_GOTOFF
:
2778 elfcpp::Elf_types
<32>::Elf_Addr value
;
2779 value
= (psymval
->value(object
, 0)
2780 - target
->got_plt_section()->address());
2781 Relocate_functions
<32, false>::rel32(view
, value
);
2785 case elfcpp::R_386_GOTPC
:
2787 elfcpp::Elf_types
<32>::Elf_Addr value
;
2788 value
= target
->got_plt_section()->address();
2789 Relocate_functions
<32, false>::pcrel32(view
, value
, address
);
2793 case elfcpp::R_386_COPY
:
2794 case elfcpp::R_386_GLOB_DAT
:
2795 case elfcpp::R_386_JUMP_SLOT
:
2796 case elfcpp::R_386_RELATIVE
:
2797 case elfcpp::R_386_IRELATIVE
:
2798 // These are outstanding tls relocs, which are unexpected when
2800 case elfcpp::R_386_TLS_TPOFF
:
2801 case elfcpp::R_386_TLS_DTPMOD32
:
2802 case elfcpp::R_386_TLS_DTPOFF32
:
2803 case elfcpp::R_386_TLS_TPOFF32
:
2804 case elfcpp::R_386_TLS_DESC
:
2805 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2806 _("unexpected reloc %u in object file"),
2810 // These are initial tls relocs, which are expected when
2812 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2813 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2814 case elfcpp::R_386_TLS_DESC_CALL
:
2815 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2816 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2817 case elfcpp::R_386_TLS_IE
: // Initial-exec
2818 case elfcpp::R_386_TLS_IE_32
:
2819 case elfcpp::R_386_TLS_GOTIE
:
2820 case elfcpp::R_386_TLS_LE
: // Local-exec
2821 case elfcpp::R_386_TLS_LE_32
:
2822 this->relocate_tls(relinfo
, target
, relnum
, rel
, r_type
, gsym
, psymval
,
2823 view
, address
, view_size
);
2826 case elfcpp::R_386_32PLT
:
2827 case elfcpp::R_386_TLS_GD_32
:
2828 case elfcpp::R_386_TLS_GD_PUSH
:
2829 case elfcpp::R_386_TLS_GD_CALL
:
2830 case elfcpp::R_386_TLS_GD_POP
:
2831 case elfcpp::R_386_TLS_LDM_32
:
2832 case elfcpp::R_386_TLS_LDM_PUSH
:
2833 case elfcpp::R_386_TLS_LDM_CALL
:
2834 case elfcpp::R_386_TLS_LDM_POP
:
2835 case elfcpp::R_386_USED_BY_INTEL_200
:
2837 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2838 _("unsupported reloc %u"),
2846 // Perform a TLS relocation.
2849 Target_i386::Relocate::relocate_tls(const Relocate_info
<32, false>* relinfo
,
2850 Target_i386
* target
,
2852 const elfcpp::Rel
<32, false>& rel
,
2853 unsigned int r_type
,
2854 const Sized_symbol
<32>* gsym
,
2855 const Symbol_value
<32>* psymval
,
2856 unsigned char* view
,
2857 elfcpp::Elf_types
<32>::Elf_Addr
,
2858 section_size_type view_size
)
2860 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
2862 const Sized_relobj_file
<32, false>* object
= relinfo
->object
;
2864 elfcpp::Elf_types
<32>::Elf_Addr value
= psymval
->value(object
, 0);
2866 const bool is_final
= (gsym
== NULL
2867 ? !parameters
->options().shared()
2868 : gsym
->final_value_is_known());
2869 const tls::Tls_optimization optimized_type
2870 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
2873 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2874 if (optimized_type
== tls::TLSOPT_TO_LE
)
2876 if (tls_segment
== NULL
)
2878 gold_assert(parameters
->errors()->error_count() > 0
2879 || issue_undefined_symbol_error(gsym
));
2882 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
2883 rel
, r_type
, value
, view
,
2889 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
2890 ? GOT_TYPE_TLS_NOFFSET
2891 : GOT_TYPE_TLS_PAIR
);
2892 unsigned int got_offset
;
2895 gold_assert(gsym
->has_got_offset(got_type
));
2896 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
2900 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2901 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
2902 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
2903 - target
->got_size());
2905 if (optimized_type
== tls::TLSOPT_TO_IE
)
2907 this->tls_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
2908 got_offset
, view
, view_size
);
2911 else if (optimized_type
== tls::TLSOPT_NONE
)
2913 // Relocate the field with the offset of the pair of GOT
2915 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2919 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2920 _("unsupported reloc %u"),
2924 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2925 case elfcpp::R_386_TLS_DESC_CALL
:
2926 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
2927 if (optimized_type
== tls::TLSOPT_TO_LE
)
2929 if (tls_segment
== NULL
)
2931 gold_assert(parameters
->errors()->error_count() > 0
2932 || issue_undefined_symbol_error(gsym
));
2935 this->tls_desc_gd_to_le(relinfo
, relnum
, tls_segment
,
2936 rel
, r_type
, value
, view
,
2942 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
2943 ? GOT_TYPE_TLS_NOFFSET
2944 : GOT_TYPE_TLS_DESC
);
2945 unsigned int got_offset
= 0;
2946 if (r_type
== elfcpp::R_386_TLS_GOTDESC
2947 && optimized_type
== tls::TLSOPT_NONE
)
2949 // We created GOT entries in the .got.tlsdesc portion of
2950 // the .got.plt section, but the offset stored in the
2951 // symbol is the offset within .got.tlsdesc.
2952 got_offset
= (target
->got_size()
2953 + target
->got_plt_section()->data_size());
2957 gold_assert(gsym
->has_got_offset(got_type
));
2958 got_offset
+= gsym
->got_offset(got_type
) - target
->got_size();
2962 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2963 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
2964 got_offset
+= (object
->local_got_offset(r_sym
, got_type
)
2965 - target
->got_size());
2967 if (optimized_type
== tls::TLSOPT_TO_IE
)
2969 if (tls_segment
== NULL
)
2971 gold_assert(parameters
->errors()->error_count() > 0
2972 || issue_undefined_symbol_error(gsym
));
2975 this->tls_desc_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
2976 got_offset
, view
, view_size
);
2979 else if (optimized_type
== tls::TLSOPT_NONE
)
2981 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
2983 // Relocate the field with the offset of the pair of GOT
2985 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2990 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2991 _("unsupported reloc %u"),
2995 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2996 if (this->local_dynamic_type_
== LOCAL_DYNAMIC_SUN
)
2998 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2999 _("both SUN and GNU model "
3000 "TLS relocations"));
3003 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
3004 if (optimized_type
== tls::TLSOPT_TO_LE
)
3006 if (tls_segment
== NULL
)
3008 gold_assert(parameters
->errors()->error_count() > 0
3009 || issue_undefined_symbol_error(gsym
));
3012 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rel
, r_type
,
3013 value
, view
, view_size
);
3016 else if (optimized_type
== tls::TLSOPT_NONE
)
3018 // Relocate the field with the offset of the GOT entry for
3019 // the module index.
3020 unsigned int got_offset
;
3021 got_offset
= (target
->got_mod_index_entry(NULL
, NULL
, NULL
)
3022 - target
->got_size());
3023 Relocate_functions
<32, false>::rel32(view
, got_offset
);
3026 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3027 _("unsupported reloc %u"),
3031 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
3032 if (optimized_type
== tls::TLSOPT_TO_LE
)
3034 // This reloc can appear in debugging sections, in which
3035 // case we must not convert to local-exec. We decide what
3036 // to do based on whether the section is marked as
3037 // containing executable code. That is what the GNU linker
3039 elfcpp::Shdr
<32, false> shdr(relinfo
->data_shdr
);
3040 if ((shdr
.get_sh_flags() & elfcpp::SHF_EXECINSTR
) != 0)
3042 if (tls_segment
== NULL
)
3044 gold_assert(parameters
->errors()->error_count() > 0
3045 || issue_undefined_symbol_error(gsym
));
3048 value
-= tls_segment
->memsz();
3051 Relocate_functions
<32, false>::rel32(view
, value
);
3054 case elfcpp::R_386_TLS_IE
: // Initial-exec
3055 case elfcpp::R_386_TLS_GOTIE
:
3056 case elfcpp::R_386_TLS_IE_32
:
3057 if (optimized_type
== tls::TLSOPT_TO_LE
)
3059 if (tls_segment
== NULL
)
3061 gold_assert(parameters
->errors()->error_count() > 0
3062 || issue_undefined_symbol_error(gsym
));
3065 Target_i386::Relocate::tls_ie_to_le(relinfo
, relnum
, tls_segment
,
3066 rel
, r_type
, value
, view
,
3070 else if (optimized_type
== tls::TLSOPT_NONE
)
3072 // Relocate the field with the offset of the GOT entry for
3073 // the tp-relative offset of the symbol.
3074 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
3075 ? GOT_TYPE_TLS_OFFSET
3076 : GOT_TYPE_TLS_NOFFSET
);
3077 unsigned int got_offset
;
3080 gold_assert(gsym
->has_got_offset(got_type
));
3081 got_offset
= gsym
->got_offset(got_type
);
3085 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
3086 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
3087 got_offset
= object
->local_got_offset(r_sym
, got_type
);
3089 // For the R_386_TLS_IE relocation, we need to apply the
3090 // absolute address of the GOT entry.
3091 if (r_type
== elfcpp::R_386_TLS_IE
)
3092 got_offset
+= target
->got_plt_section()->address();
3093 // All GOT offsets are relative to the end of the GOT.
3094 got_offset
-= target
->got_size();
3095 Relocate_functions
<32, false>::rel32(view
, got_offset
);
3098 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3099 _("unsupported reloc %u"),
3103 case elfcpp::R_386_TLS_LE
: // Local-exec
3104 // If we're creating a shared library, a dynamic relocation will
3105 // have been created for this location, so do not apply it now.
3106 if (!parameters
->options().shared())
3108 if (tls_segment
== NULL
)
3110 gold_assert(parameters
->errors()->error_count() > 0
3111 || issue_undefined_symbol_error(gsym
));
3114 value
-= tls_segment
->memsz();
3115 Relocate_functions
<32, false>::rel32(view
, value
);
3119 case elfcpp::R_386_TLS_LE_32
:
3120 // If we're creating a shared library, a dynamic relocation will
3121 // have been created for this location, so do not apply it now.
3122 if (!parameters
->options().shared())
3124 if (tls_segment
== NULL
)
3126 gold_assert(parameters
->errors()->error_count() > 0
3127 || issue_undefined_symbol_error(gsym
));
3130 value
= tls_segment
->memsz() - value
;
3131 Relocate_functions
<32, false>::rel32(view
, value
);
3137 // Do a relocation in which we convert a TLS General-Dynamic to a
3141 Target_i386::Relocate::tls_gd_to_le(const Relocate_info
<32, false>* relinfo
,
3143 Output_segment
* tls_segment
,
3144 const elfcpp::Rel
<32, false>& rel
,
3146 elfcpp::Elf_types
<32>::Elf_Addr value
,
3147 unsigned char* view
,
3148 section_size_type view_size
)
3150 // leal foo(,%reg,1),%eax; call ___tls_get_addr
3151 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
3152 // leal foo(%reg),%eax; call ___tls_get_addr
3153 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
3155 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3156 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
3158 unsigned char op1
= view
[-1];
3159 unsigned char op2
= view
[-2];
3161 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3162 op2
== 0x8d || op2
== 0x04);
3163 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
3169 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
3170 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
3171 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3172 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
3173 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3177 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3178 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
3179 if (rel
.get_r_offset() + 9 < view_size
3182 // There is a trailing nop. Use the size byte subl.
3183 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3188 // Use the five byte subl.
3189 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
3193 value
= tls_segment
->memsz() - value
;
3194 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
3196 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3198 this->skip_call_tls_get_addr_
= true;
3201 // Do a relocation in which we convert a TLS General-Dynamic to an
3205 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info
<32, false>* relinfo
,
3208 const elfcpp::Rel
<32, false>& rel
,
3210 elfcpp::Elf_types
<32>::Elf_Addr value
,
3211 unsigned char* view
,
3212 section_size_type view_size
)
3214 // leal foo(,%ebx,1),%eax; call ___tls_get_addr
3215 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
3217 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3218 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
3220 unsigned char op1
= view
[-1];
3221 unsigned char op2
= view
[-2];
3223 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3224 op2
== 0x8d || op2
== 0x04);
3225 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
3229 // FIXME: For now, support only the first (SIB) form.
3230 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), op2
== 0x04);
3234 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
3235 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
3236 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3237 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
3238 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
3242 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3243 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
3244 if (rel
.get_r_offset() + 9 < view_size
3247 // FIXME: This is not the right instruction sequence.
3248 // There is a trailing nop. Use the size byte subl.
3249 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3254 // FIXME: This is not the right instruction sequence.
3255 // Use the five byte subl.
3256 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
3260 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
3262 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3264 this->skip_call_tls_get_addr_
= true;
3267 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3268 // General-Dynamic to a Local-Exec.
3271 Target_i386::Relocate::tls_desc_gd_to_le(
3272 const Relocate_info
<32, false>* relinfo
,
3274 Output_segment
* tls_segment
,
3275 const elfcpp::Rel
<32, false>& rel
,
3276 unsigned int r_type
,
3277 elfcpp::Elf_types
<32>::Elf_Addr value
,
3278 unsigned char* view
,
3279 section_size_type view_size
)
3281 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
3283 // leal foo@TLSDESC(%ebx), %eax
3284 // ==> leal foo@NTPOFF, %eax
3285 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3286 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3287 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3288 view
[-2] == 0x8d && view
[-1] == 0x83);
3290 value
-= tls_segment
->memsz();
3291 Relocate_functions
<32, false>::rel32(view
, value
);
3295 // call *foo@TLSCALL(%eax)
3297 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
3298 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
3299 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3300 view
[0] == 0xff && view
[1] == 0x10);
3306 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3307 // General-Dynamic to an Initial-Exec.
3310 Target_i386::Relocate::tls_desc_gd_to_ie(
3311 const Relocate_info
<32, false>* relinfo
,
3314 const elfcpp::Rel
<32, false>& rel
,
3315 unsigned int r_type
,
3316 elfcpp::Elf_types
<32>::Elf_Addr value
,
3317 unsigned char* view
,
3318 section_size_type view_size
)
3320 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
3322 // leal foo@TLSDESC(%ebx), %eax
3323 // ==> movl foo@GOTNTPOFF(%ebx), %eax
3324 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3325 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3326 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3327 view
[-2] == 0x8d && view
[-1] == 0x83);
3329 Relocate_functions
<32, false>::rel32(view
, value
);
3333 // call *foo@TLSCALL(%eax)
3335 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
3336 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
3337 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3338 view
[0] == 0xff && view
[1] == 0x10);
3344 // Do a relocation in which we convert a TLS Local-Dynamic to a
3348 Target_i386::Relocate::tls_ld_to_le(const Relocate_info
<32, false>* relinfo
,
3351 const elfcpp::Rel
<32, false>& rel
,
3353 elfcpp::Elf_types
<32>::Elf_Addr
,
3354 unsigned char* view
,
3355 section_size_type view_size
)
3357 // leal foo(%reg), %eax; call ___tls_get_addr
3358 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
3360 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3361 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
3363 // FIXME: Does this test really always pass?
3364 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3365 view
[-2] == 0x8d && view
[-1] == 0x83);
3367 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
3369 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
3371 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3373 this->skip_call_tls_get_addr_
= true;
3376 // Do a relocation in which we convert a TLS Initial-Exec to a
3380 Target_i386::Relocate::tls_ie_to_le(const Relocate_info
<32, false>* relinfo
,
3382 Output_segment
* tls_segment
,
3383 const elfcpp::Rel
<32, false>& rel
,
3384 unsigned int r_type
,
3385 elfcpp::Elf_types
<32>::Elf_Addr value
,
3386 unsigned char* view
,
3387 section_size_type view_size
)
3389 // We have to actually change the instructions, which means that we
3390 // need to examine the opcodes to figure out which instruction we
3392 if (r_type
== elfcpp::R_386_TLS_IE
)
3394 // movl %gs:XX,%eax ==> movl $YY,%eax
3395 // movl %gs:XX,%reg ==> movl $YY,%reg
3396 // addl %gs:XX,%reg ==> addl $YY,%reg
3397 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -1);
3398 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3400 unsigned char op1
= view
[-1];
3403 // movl XX,%eax ==> movl $YY,%eax
3408 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3410 unsigned char op2
= view
[-2];
3413 // movl XX,%reg ==> movl $YY,%reg
3414 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3415 (op1
& 0xc7) == 0x05);
3417 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3419 else if (op2
== 0x03)
3421 // addl XX,%reg ==> addl $YY,%reg
3422 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3423 (op1
& 0xc7) == 0x05);
3425 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3428 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
3433 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
3434 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
3435 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
3436 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3437 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3439 unsigned char op1
= view
[-1];
3440 unsigned char op2
= view
[-2];
3441 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3442 (op1
& 0xc0) == 0x80 && (op1
& 7) != 4);
3445 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
3447 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3449 else if (op2
== 0x2b)
3451 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
3453 view
[-1] = 0xe8 | ((op1
>> 3) & 7);
3455 else if (op2
== 0x03)
3457 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
3459 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3462 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
3465 value
= tls_segment
->memsz() - value
;
3466 if (r_type
== elfcpp::R_386_TLS_IE
|| r_type
== elfcpp::R_386_TLS_GOTIE
)
3469 Relocate_functions
<32, false>::rel32(view
, value
);
3472 // Relocate section data.
3475 Target_i386::relocate_section(const Relocate_info
<32, false>* relinfo
,
3476 unsigned int sh_type
,
3477 const unsigned char* prelocs
,
3479 Output_section
* output_section
,
3480 bool needs_special_offset_handling
,
3481 unsigned char* view
,
3482 elfcpp::Elf_types
<32>::Elf_Addr address
,
3483 section_size_type view_size
,
3484 const Reloc_symbol_changes
* reloc_symbol_changes
)
3486 gold_assert(sh_type
== elfcpp::SHT_REL
);
3488 gold::relocate_section
<32, false, Target_i386
, elfcpp::SHT_REL
,
3489 Target_i386::Relocate
>(
3495 needs_special_offset_handling
,
3499 reloc_symbol_changes
);
3502 // Return the size of a relocation while scanning during a relocatable
3506 Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
3507 unsigned int r_type
,
3512 case elfcpp::R_386_NONE
:
3513 case elfcpp::R_386_GNU_VTINHERIT
:
3514 case elfcpp::R_386_GNU_VTENTRY
:
3515 case elfcpp::R_386_TLS_GD
: // Global-dynamic
3516 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
3517 case elfcpp::R_386_TLS_DESC_CALL
:
3518 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
3519 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
3520 case elfcpp::R_386_TLS_IE
: // Initial-exec
3521 case elfcpp::R_386_TLS_IE_32
:
3522 case elfcpp::R_386_TLS_GOTIE
:
3523 case elfcpp::R_386_TLS_LE
: // Local-exec
3524 case elfcpp::R_386_TLS_LE_32
:
3527 case elfcpp::R_386_32
:
3528 case elfcpp::R_386_PC32
:
3529 case elfcpp::R_386_GOT32
:
3530 case elfcpp::R_386_PLT32
:
3531 case elfcpp::R_386_GOTOFF
:
3532 case elfcpp::R_386_GOTPC
:
3535 case elfcpp::R_386_16
:
3536 case elfcpp::R_386_PC16
:
3539 case elfcpp::R_386_8
:
3540 case elfcpp::R_386_PC8
:
3543 // These are relocations which should only be seen by the
3544 // dynamic linker, and should never be seen here.
3545 case elfcpp::R_386_COPY
:
3546 case elfcpp::R_386_GLOB_DAT
:
3547 case elfcpp::R_386_JUMP_SLOT
:
3548 case elfcpp::R_386_RELATIVE
:
3549 case elfcpp::R_386_IRELATIVE
:
3550 case elfcpp::R_386_TLS_TPOFF
:
3551 case elfcpp::R_386_TLS_DTPMOD32
:
3552 case elfcpp::R_386_TLS_DTPOFF32
:
3553 case elfcpp::R_386_TLS_TPOFF32
:
3554 case elfcpp::R_386_TLS_DESC
:
3555 object
->error(_("unexpected reloc %u in object file"), r_type
);
3558 case elfcpp::R_386_32PLT
:
3559 case elfcpp::R_386_TLS_GD_32
:
3560 case elfcpp::R_386_TLS_GD_PUSH
:
3561 case elfcpp::R_386_TLS_GD_CALL
:
3562 case elfcpp::R_386_TLS_GD_POP
:
3563 case elfcpp::R_386_TLS_LDM_32
:
3564 case elfcpp::R_386_TLS_LDM_PUSH
:
3565 case elfcpp::R_386_TLS_LDM_CALL
:
3566 case elfcpp::R_386_TLS_LDM_POP
:
3567 case elfcpp::R_386_USED_BY_INTEL_200
:
3569 object
->error(_("unsupported reloc %u in object file"), r_type
);
3574 // Scan the relocs during a relocatable link.
3577 Target_i386::scan_relocatable_relocs(Symbol_table
* symtab
,
3579 Sized_relobj_file
<32, false>* object
,
3580 unsigned int data_shndx
,
3581 unsigned int sh_type
,
3582 const unsigned char* prelocs
,
3584 Output_section
* output_section
,
3585 bool needs_special_offset_handling
,
3586 size_t local_symbol_count
,
3587 const unsigned char* plocal_symbols
,
3588 Relocatable_relocs
* rr
)
3590 gold_assert(sh_type
== elfcpp::SHT_REL
);
3592 typedef gold::Default_scan_relocatable_relocs
<elfcpp::SHT_REL
,
3593 Relocatable_size_for_reloc
> Scan_relocatable_relocs
;
3595 gold::scan_relocatable_relocs
<32, false, elfcpp::SHT_REL
,
3596 Scan_relocatable_relocs
>(
3604 needs_special_offset_handling
,
3610 // Emit relocations for a section.
3613 Target_i386::relocate_relocs(
3614 const Relocate_info
<32, false>* relinfo
,
3615 unsigned int sh_type
,
3616 const unsigned char* prelocs
,
3618 Output_section
* output_section
,
3619 off_t offset_in_output_section
,
3620 const Relocatable_relocs
* rr
,
3621 unsigned char* view
,
3622 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
3623 section_size_type view_size
,
3624 unsigned char* reloc_view
,
3625 section_size_type reloc_view_size
)
3627 gold_assert(sh_type
== elfcpp::SHT_REL
);
3629 gold::relocate_relocs
<32, false, elfcpp::SHT_REL
>(
3634 offset_in_output_section
,
3643 // Return the value to use for a dynamic which requires special
3644 // treatment. This is how we support equality comparisons of function
3645 // pointers across shared library boundaries, as described in the
3646 // processor specific ABI supplement.
3649 Target_i386::do_dynsym_value(const Symbol
* gsym
) const
3651 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
3652 return this->plt_address_for_global(gsym
) + gsym
->plt_offset();
3655 // Return a string used to fill a code section with nops to take up
3656 // the specified length.
3659 Target_i386::do_code_fill(section_size_type length
) const
3663 // Build a jmp instruction to skip over the bytes.
3664 unsigned char jmp
[5];
3666 elfcpp::Swap_unaligned
<32, false>::writeval(jmp
+ 1, length
- 5);
3667 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
3668 + std::string(length
- 5, static_cast<char>(0x90)));
3671 // Nop sequences of various lengths.
3672 const char nop1
[1] = { '\x90' }; // nop
3673 const char nop2
[2] = { '\x66', '\x90' }; // xchg %ax %ax
3674 const char nop3
[3] = { '\x8d', '\x76', '\x00' }; // leal 0(%esi),%esi
3675 const char nop4
[4] = { '\x8d', '\x74', '\x26', // leal 0(%esi,1),%esi
3677 const char nop5
[5] = { '\x90', '\x8d', '\x74', // nop
3678 '\x26', '\x00' }; // leal 0(%esi,1),%esi
3679 const char nop6
[6] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3680 '\x00', '\x00', '\x00' };
3681 const char nop7
[7] = { '\x8d', '\xb4', '\x26', // leal 0L(%esi,1),%esi
3682 '\x00', '\x00', '\x00',
3684 const char nop8
[8] = { '\x90', '\x8d', '\xb4', // nop
3685 '\x26', '\x00', '\x00', // leal 0L(%esi,1),%esi
3687 const char nop9
[9] = { '\x89', '\xf6', '\x8d', // movl %esi,%esi
3688 '\xbc', '\x27', '\x00', // leal 0L(%edi,1),%edi
3689 '\x00', '\x00', '\x00' };
3690 const char nop10
[10] = { '\x8d', '\x76', '\x00', // leal 0(%esi),%esi
3691 '\x8d', '\xbc', '\x27', // leal 0L(%edi,1),%edi
3692 '\x00', '\x00', '\x00',
3694 const char nop11
[11] = { '\x8d', '\x74', '\x26', // leal 0(%esi,1),%esi
3695 '\x00', '\x8d', '\xbc', // leal 0L(%edi,1),%edi
3696 '\x27', '\x00', '\x00',
3698 const char nop12
[12] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3699 '\x00', '\x00', '\x00', // leal 0L(%edi),%edi
3700 '\x8d', '\xbf', '\x00',
3701 '\x00', '\x00', '\x00' };
3702 const char nop13
[13] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3703 '\x00', '\x00', '\x00', // leal 0L(%edi,1),%edi
3704 '\x8d', '\xbc', '\x27',
3705 '\x00', '\x00', '\x00',
3707 const char nop14
[14] = { '\x8d', '\xb4', '\x26', // leal 0L(%esi,1),%esi
3708 '\x00', '\x00', '\x00', // leal 0L(%edi,1),%edi
3709 '\x00', '\x8d', '\xbc',
3710 '\x27', '\x00', '\x00',
3712 const char nop15
[15] = { '\xeb', '\x0d', '\x90', // jmp .+15
3713 '\x90', '\x90', '\x90', // nop,nop,nop,...
3714 '\x90', '\x90', '\x90',
3715 '\x90', '\x90', '\x90',
3716 '\x90', '\x90', '\x90' };
3718 const char* nops
[16] = {
3720 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
3721 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
3724 return std::string(nops
[length
], length
);
3727 // Return the value to use for the base of a DW_EH_PE_datarel offset
3728 // in an FDE. Solaris and SVR4 use DW_EH_PE_datarel because their
3729 // assembler can not write out the difference between two labels in
3730 // different sections, so instead of using a pc-relative value they
3731 // use an offset from the GOT.
3734 Target_i386::do_ehframe_datarel_base() const
3736 gold_assert(this->global_offset_table_
!= NULL
);
3737 Symbol
* sym
= this->global_offset_table_
;
3738 Sized_symbol
<32>* ssym
= static_cast<Sized_symbol
<32>*>(sym
);
3739 return ssym
->value();
3742 // Return whether SYM should be treated as a call to a non-split
3743 // function. We don't want that to be true of a call to a
3744 // get_pc_thunk function.
3747 Target_i386::do_is_call_to_non_split(const Symbol
* sym
, unsigned int) const
3749 return (sym
->type() == elfcpp::STT_FUNC
3750 && !is_prefix_of("__i686.get_pc_thunk.", sym
->name()));
3753 // FNOFFSET in section SHNDX in OBJECT is the start of a function
3754 // compiled with -fsplit-stack. The function calls non-split-stack
3755 // code. We have to change the function so that it always ensures
3756 // that it has enough stack space to run some random function.
3759 Target_i386::do_calls_non_split(Relobj
* object
, unsigned int shndx
,
3760 section_offset_type fnoffset
,
3761 section_size_type fnsize
,
3762 unsigned char* view
,
3763 section_size_type view_size
,
3765 std::string
* to
) const
3767 // The function starts with a comparison of the stack pointer and a
3768 // field in the TCB. This is followed by a jump.
3771 if (this->match_view(view
, view_size
, fnoffset
, "\x65\x3b\x25", 3)
3774 // We will call __morestack if the carry flag is set after this
3775 // comparison. We turn the comparison into an stc instruction
3777 view
[fnoffset
] = '\xf9';
3778 this->set_view_to_nop(view
, view_size
, fnoffset
+ 1, 6);
3780 // lea NN(%esp),%ecx
3781 // lea NN(%esp),%edx
3782 else if ((this->match_view(view
, view_size
, fnoffset
, "\x8d\x8c\x24", 3)
3783 || this->match_view(view
, view_size
, fnoffset
, "\x8d\x94\x24", 3))
3786 // This is loading an offset from the stack pointer for a
3787 // comparison. The offset is negative, so we decrease the
3788 // offset by the amount of space we need for the stack. This
3789 // means we will avoid calling __morestack if there happens to
3790 // be plenty of space on the stack already.
3791 unsigned char* pval
= view
+ fnoffset
+ 3;
3792 uint32_t val
= elfcpp::Swap_unaligned
<32, false>::readval(pval
);
3793 val
-= parameters
->options().split_stack_adjust_size();
3794 elfcpp::Swap_unaligned
<32, false>::writeval(pval
, val
);
3798 if (!object
->has_no_split_stack())
3799 object
->error(_("failed to match split-stack sequence at "
3800 "section %u offset %0zx"),
3801 shndx
, static_cast<size_t>(fnoffset
));
3805 // We have to change the function so that it calls
3806 // __morestack_non_split instead of __morestack. The former will
3807 // allocate additional stack space.
3808 *from
= "__morestack";
3809 *to
= "__morestack_non_split";
3812 // The selector for i386 object files. Note this is never instantiated
3813 // directly. It's only used in Target_selector_i386_nacl, below.
3815 class Target_selector_i386
: public Target_selector_freebsd
3818 Target_selector_i386()
3819 : Target_selector_freebsd(elfcpp::EM_386
, 32, false,
3820 "elf32-i386", "elf32-i386-freebsd",
3825 do_instantiate_target()
3826 { return new Target_i386(); }
3829 // NaCl variant. It uses different PLT contents.
3831 class Output_data_plt_i386_nacl
: public Output_data_plt_i386
3834 Output_data_plt_i386_nacl(Layout
* layout
,
3835 Output_data_space
* got_plt
,
3836 Output_data_space
* got_irelative
)
3837 : Output_data_plt_i386(layout
, plt_entry_size
, got_plt
, got_irelative
)
3841 virtual unsigned int
3842 do_get_plt_entry_size() const
3843 { return plt_entry_size
; }
3846 do_add_eh_frame(Layout
* layout
)
3848 layout
->add_eh_frame_for_plt(this, plt_eh_frame_cie
, plt_eh_frame_cie_size
,
3849 plt_eh_frame_fde
, plt_eh_frame_fde_size
);
3852 // The size of an entry in the PLT.
3853 static const int plt_entry_size
= 64;
3855 // The .eh_frame unwind information for the PLT.
3856 static const int plt_eh_frame_fde_size
= 32;
3857 static const unsigned char plt_eh_frame_fde
[plt_eh_frame_fde_size
];
3860 class Output_data_plt_i386_nacl_exec
: public Output_data_plt_i386_nacl
3863 Output_data_plt_i386_nacl_exec(Layout
* layout
,
3864 Output_data_space
* got_plt
,
3865 Output_data_space
* got_irelative
)
3866 : Output_data_plt_i386_nacl(layout
, got_plt
, got_irelative
)
3871 do_fill_first_plt_entry(unsigned char* pov
,
3872 elfcpp::Elf_types
<32>::Elf_Addr got_address
);
3874 virtual unsigned int
3875 do_fill_plt_entry(unsigned char* pov
,
3876 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
3877 unsigned int got_offset
,
3878 unsigned int plt_offset
,
3879 unsigned int plt_rel_offset
);
3882 // The first entry in the PLT for an executable.
3883 static const unsigned char first_plt_entry
[plt_entry_size
];
3885 // Other entries in the PLT for an executable.
3886 static const unsigned char plt_entry
[plt_entry_size
];
3889 class Output_data_plt_i386_nacl_dyn
: public Output_data_plt_i386_nacl
3892 Output_data_plt_i386_nacl_dyn(Layout
* layout
,
3893 Output_data_space
* got_plt
,
3894 Output_data_space
* got_irelative
)
3895 : Output_data_plt_i386_nacl(layout
, got_plt
, got_irelative
)
3900 do_fill_first_plt_entry(unsigned char* pov
, elfcpp::Elf_types
<32>::Elf_Addr
);
3902 virtual unsigned int
3903 do_fill_plt_entry(unsigned char* pov
,
3904 elfcpp::Elf_types
<32>::Elf_Addr
,
3905 unsigned int got_offset
,
3906 unsigned int plt_offset
,
3907 unsigned int plt_rel_offset
);
3910 // The first entry in the PLT for a shared object.
3911 static const unsigned char first_plt_entry
[plt_entry_size
];
3913 // Other entries in the PLT for a shared object.
3914 static const unsigned char plt_entry
[plt_entry_size
];
3917 class Target_i386_nacl
: public Target_i386
3921 : Target_i386(&i386_nacl_info
)
3925 virtual Output_data_plt_i386
*
3926 do_make_data_plt(Layout
* layout
,
3927 Output_data_space
* got_plt
,
3928 Output_data_space
* got_irelative
,
3932 return new Output_data_plt_i386_nacl_dyn(layout
, got_plt
, got_irelative
);
3934 return new Output_data_plt_i386_nacl_exec(layout
, got_plt
, got_irelative
);
3938 static const Target::Target_info i386_nacl_info
;
3941 const Target::Target_info
Target_i386_nacl::i386_nacl_info
=
3944 false, // is_big_endian
3945 elfcpp::EM_386
, // machine_code
3946 false, // has_make_symbol
3947 false, // has_resolve
3948 true, // has_code_fill
3949 true, // is_default_stack_executable
3950 true, // can_icf_inline_merge_sections
3952 "/lib/ld-nacl-x86-32.so.1", // dynamic_linker
3953 0x20000, // default_text_segment_address
3954 0x10000, // abi_pagesize (overridable by -z max-page-size)
3955 0x10000, // common_pagesize (overridable by -z common-page-size)
3956 true, // isolate_execinstr
3957 0x10000000, // rosegment_gap
3958 elfcpp::SHN_UNDEF
, // small_common_shndx
3959 elfcpp::SHN_UNDEF
, // large_common_shndx
3960 0, // small_common_section_flags
3961 0, // large_common_section_flags
3962 NULL
, // attributes_section
3963 NULL
// attributes_vendor
3966 #define NACLMASK 0xe0 // 32-byte alignment mask
3969 Output_data_plt_i386_nacl_exec::first_plt_entry
[plt_entry_size
] =
3971 0xff, 0x35, // pushl contents of memory address
3972 0, 0, 0, 0, // replaced with address of .got + 4
3973 0x8b, 0x0d, // movl contents of address, %ecx
3974 0, 0, 0, 0, // replaced with address of .got + 8
3975 0x83, 0xe1, NACLMASK
, // andl $NACLMASK, %ecx
3976 0xff, 0xe1, // jmp *%ecx
3977 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3978 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3979 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3980 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3981 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3982 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3983 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3984 0x90, 0x90, 0x90, 0x90, 0x90
3988 Output_data_plt_i386_nacl_exec::do_fill_first_plt_entry(
3990 elfcpp::Elf_types
<32>::Elf_Addr got_address
)
3992 memcpy(pov
, first_plt_entry
, plt_entry_size
);
3993 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 4);
3994 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 8);
3997 // The first entry in the PLT for a shared object.
4000 Output_data_plt_i386_nacl_dyn::first_plt_entry
[plt_entry_size
] =
4002 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
4003 0x8b, 0x4b, 0x08, // mov 0x8(%ebx), %ecx
4004 0x83, 0xe1, NACLMASK
, // andl $NACLMASK, %ecx
4005 0xff, 0xe1, // jmp *%ecx
4006 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4007 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4008 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4009 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4010 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4011 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4012 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4013 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4014 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4015 0x90, 0x90, 0x90, 0x90, 0x90 // nops
4019 Output_data_plt_i386_nacl_dyn::do_fill_first_plt_entry(
4021 elfcpp::Elf_types
<32>::Elf_Addr
)
4023 memcpy(pov
, first_plt_entry
, plt_entry_size
);
4026 // Subsequent entries in the PLT for an executable.
4029 Output_data_plt_i386_nacl_exec::plt_entry
[plt_entry_size
] =
4031 0x8b, 0x0d, // movl contents of address, %ecx */
4032 0, 0, 0, 0, // replaced with address of symbol in .got
4033 0x83, 0xe1, NACLMASK
, // andl $NACLMASK, %ecx
4034 0xff, 0xe1, // jmp *%ecx
4036 // Pad to the next 32-byte boundary with nop instructions.
4038 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4039 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4041 // Lazy GOT entries point here (32-byte aligned).
4042 0x68, // pushl immediate
4043 0, 0, 0, 0, // replaced with offset into relocation table
4044 0xe9, // jmp relative
4045 0, 0, 0, 0, // replaced with offset to start of .plt
4047 // Pad to the next 32-byte boundary with nop instructions.
4048 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4049 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4054 Output_data_plt_i386_nacl_exec::do_fill_plt_entry(
4056 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
4057 unsigned int got_offset
,
4058 unsigned int plt_offset
,
4059 unsigned int plt_rel_offset
)
4061 memcpy(pov
, plt_entry
, plt_entry_size
);
4062 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
4063 got_address
+ got_offset
);
4064 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 33, plt_rel_offset
);
4065 elfcpp::Swap
<32, false>::writeval(pov
+ 38, - (plt_offset
+ 38 + 4));
4069 // Subsequent entries in the PLT for a shared object.
4072 Output_data_plt_i386_nacl_dyn::plt_entry
[plt_entry_size
] =
4074 0x8b, 0x8b, // movl offset(%ebx), %ecx
4075 0, 0, 0, 0, // replaced with offset of symbol in .got
4076 0x83, 0xe1, 0xe0, // andl $NACLMASK, %ecx
4077 0xff, 0xe1, // jmp *%ecx
4079 // Pad to the next 32-byte boundary with nop instructions.
4081 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4082 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4084 // Lazy GOT entries point here (32-byte aligned).
4085 0x68, // pushl immediate
4086 0, 0, 0, 0, // replaced with offset into relocation table.
4087 0xe9, // jmp relative
4088 0, 0, 0, 0, // replaced with offset to start of .plt.
4090 // Pad to the next 32-byte boundary with nop instructions.
4091 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4092 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4097 Output_data_plt_i386_nacl_dyn::do_fill_plt_entry(
4099 elfcpp::Elf_types
<32>::Elf_Addr
,
4100 unsigned int got_offset
,
4101 unsigned int plt_offset
,
4102 unsigned int plt_rel_offset
)
4104 memcpy(pov
, plt_entry
, plt_entry_size
);
4105 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
4106 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 33, plt_rel_offset
);
4107 elfcpp::Swap
<32, false>::writeval(pov
+ 38, - (plt_offset
+ 38 + 4));
4112 Output_data_plt_i386_nacl::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
4114 0, 0, 0, 0, // Replaced with offset to .plt.
4115 0, 0, 0, 0, // Replaced with size of .plt.
4116 0, // Augmentation size.
4117 elfcpp::DW_CFA_def_cfa_offset
, 8, // DW_CFA_def_cfa_offset: 8.
4118 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
4119 elfcpp::DW_CFA_def_cfa_offset
, 12, // DW_CFA_def_cfa_offset: 12.
4120 elfcpp::DW_CFA_advance_loc
+ 58, // Advance 58 to __PLT__ + 64.
4121 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
4122 13, // Block length.
4123 elfcpp::DW_OP_breg4
, 4, // Push %esp + 4.
4124 elfcpp::DW_OP_breg8
, 0, // Push %eip.
4125 elfcpp::DW_OP_const1u
, 63, // Push 0x3f.
4126 elfcpp::DW_OP_and
, // & (%eip & 0x3f).
4127 elfcpp::DW_OP_const1u
, 37, // Push 0x25.
4128 elfcpp::DW_OP_ge
, // >= ((%eip & 0x3f) >= 0x25)
4129 elfcpp::DW_OP_lit2
, // Push 2.
4130 elfcpp::DW_OP_shl
, // << (((%eip & 0x3f) >= 0x25) << 2)
4131 elfcpp::DW_OP_plus
, // + ((((%eip&0x3f)>=0x25)<<2)+%esp+4
4132 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
4136 // The selector for i386-nacl object files.
4138 class Target_selector_i386_nacl
4139 : public Target_selector_nacl
<Target_selector_i386
, Target_i386_nacl
>
4142 Target_selector_i386_nacl()
4143 : Target_selector_nacl
<Target_selector_i386
,
4144 Target_i386_nacl
>("x86-32",
4150 Target_selector_i386_nacl target_selector_i386
;
4152 } // End anonymous namespace.