1 // i386.cc -- i386 target support for gold.
3 // Copyright 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013
4 // Free Software Foundation, Inc.
5 // Written by Ian Lance Taylor <iant@google.com>.
7 // This file is part of gold.
9 // This program is free software; you can redistribute it and/or modify
10 // it under the terms of the GNU General Public License as published by
11 // the Free Software Foundation; either version 3 of the License, or
12 // (at your option) any later version.
14 // This program is distributed in the hope that it will be useful,
15 // but WITHOUT ANY WARRANTY; without even the implied warranty of
16 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 // GNU General Public License for more details.
19 // You should have received a copy of the GNU General Public License
20 // along with this program; if not, write to the Free Software
21 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
22 // MA 02110-1301, USA.
30 #include "parameters.h"
37 #include "copy-relocs.h"
39 #include "target-reloc.h"
40 #include "target-select.h"
51 // A class to handle the PLT data.
52 // This is an abstract base class that handles most of the linker details
53 // but does not know the actual contents of PLT entries. The derived
54 // classes below fill in those details.
56 class Output_data_plt_i386
: public Output_section_data
59 typedef Output_data_reloc
<elfcpp::SHT_REL
, true, 32, false> Reloc_section
;
61 Output_data_plt_i386(Layout
*, uint64_t addralign
,
62 Output_data_space
*, Output_data_space
*);
64 // Add an entry to the PLT.
66 add_entry(Symbol_table
*, Layout
*, Symbol
* gsym
);
68 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
70 add_local_ifunc_entry(Symbol_table
*, Layout
*,
71 Sized_relobj_file
<32, false>* relobj
,
72 unsigned int local_sym_index
);
74 // Return the .rel.plt section data.
77 { return this->rel_
; }
79 // Return where the TLS_DESC relocations should go.
81 rel_tls_desc(Layout
*);
83 // Return where the IRELATIVE relocations should go.
85 rel_irelative(Symbol_table
*, Layout
*);
87 // Return whether we created a section for IRELATIVE relocations.
89 has_irelative_section() const
90 { return this->irelative_rel_
!= NULL
; }
92 // Return the number of PLT entries.
95 { return this->count_
+ this->irelative_count_
; }
97 // Return the offset of the first non-reserved PLT entry.
99 first_plt_entry_offset()
100 { return this->get_plt_entry_size(); }
102 // Return the size of a PLT entry.
104 get_plt_entry_size() const
105 { return this->do_get_plt_entry_size(); }
107 // Return the PLT address to use for a global symbol.
109 address_for_global(const Symbol
*);
111 // Return the PLT address to use for a local symbol.
113 address_for_local(const Relobj
*, unsigned int symndx
);
115 // Add .eh_frame information for the PLT.
117 add_eh_frame(Layout
* layout
)
118 { this->do_add_eh_frame(layout
); }
121 // Fill the first PLT entry, given the pointer to the PLT section data
122 // and the runtime address of the GOT.
124 fill_first_plt_entry(unsigned char* pov
,
125 elfcpp::Elf_types
<32>::Elf_Addr got_address
)
126 { this->do_fill_first_plt_entry(pov
, got_address
); }
128 // Fill a normal PLT entry, given the pointer to the entry's data in the
129 // section, the runtime address of the GOT, the offset into the GOT of
130 // the corresponding slot, the offset into the relocation section of the
131 // corresponding reloc, and the offset of this entry within the whole
132 // PLT. Return the offset from this PLT entry's runtime address that
133 // should be used to compute the initial value of the GOT slot.
135 fill_plt_entry(unsigned char* pov
,
136 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
137 unsigned int got_offset
,
138 unsigned int plt_offset
,
139 unsigned int plt_rel_offset
)
141 return this->do_fill_plt_entry(pov
, got_address
, got_offset
,
142 plt_offset
, plt_rel_offset
);
146 do_get_plt_entry_size() const = 0;
149 do_fill_first_plt_entry(unsigned char* pov
,
150 elfcpp::Elf_types
<32>::Elf_Addr got_address
) = 0;
153 do_fill_plt_entry(unsigned char* pov
,
154 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
155 unsigned int got_offset
,
156 unsigned int plt_offset
,
157 unsigned int plt_rel_offset
) = 0;
160 do_add_eh_frame(Layout
*) = 0;
163 do_adjust_output_section(Output_section
* os
);
165 // Write to a map file.
167 do_print_to_mapfile(Mapfile
* mapfile
) const
168 { mapfile
->print_output_data(this, _("** PLT")); }
170 // The .eh_frame unwind information for the PLT.
171 // The CIE is common across variants of the PLT format.
172 static const int plt_eh_frame_cie_size
= 16;
173 static const unsigned char plt_eh_frame_cie
[plt_eh_frame_cie_size
];
176 // Set the final size.
178 set_final_data_size()
180 this->set_data_size((this->count_
+ this->irelative_count_
+ 1)
181 * this->get_plt_entry_size());
184 // Write out the PLT data.
186 do_write(Output_file
*);
188 // We keep a list of global STT_GNU_IFUNC symbols, each with its
189 // offset in the GOT.
193 unsigned int got_offset
;
196 // We keep a list of local STT_GNU_IFUNC symbols, each with its
197 // offset in the GOT.
200 Sized_relobj_file
<32, false>* object
;
201 unsigned int local_sym_index
;
202 unsigned int got_offset
;
205 // A pointer to the Layout class, so that we can find the .dynamic
206 // section when we write out the GOT PLT section.
208 // The reloc section.
210 // The TLS_DESC relocations, if necessary. These must follow the
211 // regular PLT relocs.
212 Reloc_section
* tls_desc_rel_
;
213 // The IRELATIVE relocations, if necessary. These must follow the
214 // regular relocatoins and the TLS_DESC relocations.
215 Reloc_section
* irelative_rel_
;
216 // The .got.plt section.
217 Output_data_space
* got_plt_
;
218 // The part of the .got.plt section used for IRELATIVE relocs.
219 Output_data_space
* got_irelative_
;
220 // The number of PLT entries.
222 // Number of PLT entries with R_386_IRELATIVE relocs. These follow
223 // the regular PLT entries.
224 unsigned int irelative_count_
;
225 // Global STT_GNU_IFUNC symbols.
226 std::vector
<Global_ifunc
> global_ifuncs_
;
227 // Local STT_GNU_IFUNC symbols.
228 std::vector
<Local_ifunc
> local_ifuncs_
;
231 // This is an abstract class for the standard PLT layout.
232 // The derived classes below handle the actual PLT contents
233 // for the executable (non-PIC) and shared-library (PIC) cases.
234 // The unwind information is uniform across those two, so it's here.
236 class Output_data_plt_i386_standard
: public Output_data_plt_i386
239 Output_data_plt_i386_standard(Layout
* layout
,
240 Output_data_space
* got_plt
,
241 Output_data_space
* got_irelative
)
242 : Output_data_plt_i386(layout
, plt_entry_size
, got_plt
, got_irelative
)
247 do_get_plt_entry_size() const
248 { return plt_entry_size
; }
251 do_add_eh_frame(Layout
* layout
)
253 layout
->add_eh_frame_for_plt(this, plt_eh_frame_cie
, plt_eh_frame_cie_size
,
254 plt_eh_frame_fde
, plt_eh_frame_fde_size
);
257 // The size of an entry in the PLT.
258 static const int plt_entry_size
= 16;
260 // The .eh_frame unwind information for the PLT.
261 static const int plt_eh_frame_fde_size
= 32;
262 static const unsigned char plt_eh_frame_fde
[plt_eh_frame_fde_size
];
265 // Actually fill the PLT contents for an executable (non-PIC).
267 class Output_data_plt_i386_exec
: public Output_data_plt_i386_standard
270 Output_data_plt_i386_exec(Layout
* layout
,
271 Output_data_space
* got_plt
,
272 Output_data_space
* got_irelative
)
273 : Output_data_plt_i386_standard(layout
, got_plt
, got_irelative
)
278 do_fill_first_plt_entry(unsigned char* pov
,
279 elfcpp::Elf_types
<32>::Elf_Addr got_address
);
282 do_fill_plt_entry(unsigned char* pov
,
283 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
284 unsigned int got_offset
,
285 unsigned int plt_offset
,
286 unsigned int plt_rel_offset
);
289 // The first entry in the PLT for an executable.
290 static const unsigned char first_plt_entry
[plt_entry_size
];
292 // Other entries in the PLT for an executable.
293 static const unsigned char plt_entry
[plt_entry_size
];
296 // Actually fill the PLT contents for a shared library (PIC).
298 class Output_data_plt_i386_dyn
: public Output_data_plt_i386_standard
301 Output_data_plt_i386_dyn(Layout
* layout
,
302 Output_data_space
* got_plt
,
303 Output_data_space
* got_irelative
)
304 : Output_data_plt_i386_standard(layout
, got_plt
, got_irelative
)
309 do_fill_first_plt_entry(unsigned char* pov
, elfcpp::Elf_types
<32>::Elf_Addr
);
312 do_fill_plt_entry(unsigned char* pov
,
313 elfcpp::Elf_types
<32>::Elf_Addr
,
314 unsigned int got_offset
,
315 unsigned int plt_offset
,
316 unsigned int plt_rel_offset
);
319 // The first entry in the PLT for a shared object.
320 static const unsigned char first_plt_entry
[plt_entry_size
];
322 // Other entries in the PLT for a shared object.
323 static const unsigned char plt_entry
[plt_entry_size
];
326 // The i386 target class.
327 // TLS info comes from
328 // http://people.redhat.com/drepper/tls.pdf
329 // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
331 class Target_i386
: public Sized_target
<32, false>
334 typedef Output_data_reloc
<elfcpp::SHT_REL
, true, 32, false> Reloc_section
;
336 Target_i386(const Target::Target_info
* info
= &i386_info
)
337 : Sized_target
<32, false>(info
),
338 got_(NULL
), plt_(NULL
), got_plt_(NULL
), got_irelative_(NULL
),
339 got_tlsdesc_(NULL
), global_offset_table_(NULL
), rel_dyn_(NULL
),
340 rel_irelative_(NULL
), copy_relocs_(elfcpp::R_386_COPY
),
341 got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
344 // Process the relocations to determine unreferenced sections for
345 // garbage collection.
347 gc_process_relocs(Symbol_table
* symtab
,
349 Sized_relobj_file
<32, false>* object
,
350 unsigned int data_shndx
,
351 unsigned int sh_type
,
352 const unsigned char* prelocs
,
354 Output_section
* output_section
,
355 bool needs_special_offset_handling
,
356 size_t local_symbol_count
,
357 const unsigned char* plocal_symbols
);
359 // Scan the relocations to look for symbol adjustments.
361 scan_relocs(Symbol_table
* symtab
,
363 Sized_relobj_file
<32, false>* object
,
364 unsigned int data_shndx
,
365 unsigned int sh_type
,
366 const unsigned char* prelocs
,
368 Output_section
* output_section
,
369 bool needs_special_offset_handling
,
370 size_t local_symbol_count
,
371 const unsigned char* plocal_symbols
);
373 // Finalize the sections.
375 do_finalize_sections(Layout
*, const Input_objects
*, Symbol_table
*);
377 // Return the value to use for a dynamic which requires special
380 do_dynsym_value(const Symbol
*) const;
382 // Relocate a section.
384 relocate_section(const Relocate_info
<32, false>*,
385 unsigned int sh_type
,
386 const unsigned char* prelocs
,
388 Output_section
* output_section
,
389 bool needs_special_offset_handling
,
391 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
392 section_size_type view_size
,
393 const Reloc_symbol_changes
*);
395 // Scan the relocs during a relocatable link.
397 scan_relocatable_relocs(Symbol_table
* symtab
,
399 Sized_relobj_file
<32, false>* object
,
400 unsigned int data_shndx
,
401 unsigned int sh_type
,
402 const unsigned char* prelocs
,
404 Output_section
* output_section
,
405 bool needs_special_offset_handling
,
406 size_t local_symbol_count
,
407 const unsigned char* plocal_symbols
,
408 Relocatable_relocs
*);
410 // Emit relocations for a section.
412 relocate_relocs(const Relocate_info
<32, false>*,
413 unsigned int sh_type
,
414 const unsigned char* prelocs
,
416 Output_section
* output_section
,
417 elfcpp::Elf_types
<32>::Elf_Off offset_in_output_section
,
418 const Relocatable_relocs
*,
420 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
421 section_size_type view_size
,
422 unsigned char* reloc_view
,
423 section_size_type reloc_view_size
);
425 // Return a string used to fill a code section with nops.
427 do_code_fill(section_size_type length
) const;
429 // Return whether SYM is defined by the ABI.
431 do_is_defined_by_abi(const Symbol
* sym
) const
432 { return strcmp(sym
->name(), "___tls_get_addr") == 0; }
434 // Return whether a symbol name implies a local label. The UnixWare
435 // 2.1 cc generates temporary symbols that start with .X, so we
436 // recognize them here. FIXME: do other SVR4 compilers also use .X?.
437 // If so, we should move the .X recognition into
438 // Target::do_is_local_label_name.
440 do_is_local_label_name(const char* name
) const
442 if (name
[0] == '.' && name
[1] == 'X')
444 return Target::do_is_local_label_name(name
);
447 // Return the PLT address to use for a global symbol.
449 do_plt_address_for_global(const Symbol
* gsym
) const
450 { return this->plt_section()->address_for_global(gsym
); }
453 do_plt_address_for_local(const Relobj
* relobj
, unsigned int symndx
) const
454 { return this->plt_section()->address_for_local(relobj
, symndx
); }
456 // We can tell whether we take the address of a function.
458 do_can_check_for_function_pointers() const
461 // Return the base for a DW_EH_PE_datarel encoding.
463 do_ehframe_datarel_base() const;
465 // Return whether SYM is call to a non-split function.
467 do_is_call_to_non_split(const Symbol
* sym
, unsigned int) const;
469 // Adjust -fsplit-stack code which calls non-split-stack code.
471 do_calls_non_split(Relobj
* object
, unsigned int shndx
,
472 section_offset_type fnoffset
, section_size_type fnsize
,
473 unsigned char* view
, section_size_type view_size
,
474 std::string
* from
, std::string
* to
) const;
476 // Return the size of the GOT section.
480 gold_assert(this->got_
!= NULL
);
481 return this->got_
->data_size();
484 // Return the number of entries in the GOT.
486 got_entry_count() const
488 if (this->got_
== NULL
)
490 return this->got_size() / 4;
493 // Return the number of entries in the PLT.
495 plt_entry_count() const;
497 // Return the offset of the first non-reserved PLT entry.
499 first_plt_entry_offset() const;
501 // Return the size of each PLT entry.
503 plt_entry_size() const;
506 // Instantiate the plt_ member.
507 // This chooses the right PLT flavor for an executable or a shared object.
508 Output_data_plt_i386
*
509 make_data_plt(Layout
* layout
,
510 Output_data_space
* got_plt
,
511 Output_data_space
* got_irelative
,
513 { return this->do_make_data_plt(layout
, got_plt
, got_irelative
, dyn
); }
515 virtual Output_data_plt_i386
*
516 do_make_data_plt(Layout
* layout
,
517 Output_data_space
* got_plt
,
518 Output_data_space
* got_irelative
,
522 return new Output_data_plt_i386_dyn(layout
, got_plt
, got_irelative
);
524 return new Output_data_plt_i386_exec(layout
, got_plt
, got_irelative
);
528 // The class which scans relocations.
533 get_reference_flags(unsigned int r_type
);
536 local(Symbol_table
* symtab
, Layout
* layout
, Target_i386
* target
,
537 Sized_relobj_file
<32, false>* object
,
538 unsigned int data_shndx
,
539 Output_section
* output_section
,
540 const elfcpp::Rel
<32, false>& reloc
, unsigned int r_type
,
541 const elfcpp::Sym
<32, false>& lsym
,
545 global(Symbol_table
* symtab
, Layout
* layout
, Target_i386
* target
,
546 Sized_relobj_file
<32, false>* object
,
547 unsigned int data_shndx
,
548 Output_section
* output_section
,
549 const elfcpp::Rel
<32, false>& reloc
, unsigned int r_type
,
553 local_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
555 Sized_relobj_file
<32, false>* object
,
556 unsigned int data_shndx
,
557 Output_section
* output_section
,
558 const elfcpp::Rel
<32, false>& reloc
,
560 const elfcpp::Sym
<32, false>& lsym
);
563 global_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
565 Sized_relobj_file
<32, false>* object
,
566 unsigned int data_shndx
,
567 Output_section
* output_section
,
568 const elfcpp::Rel
<32, false>& reloc
,
573 possible_function_pointer_reloc(unsigned int r_type
);
576 reloc_needs_plt_for_ifunc(Sized_relobj_file
<32, false>*,
577 unsigned int r_type
);
580 unsupported_reloc_local(Sized_relobj_file
<32, false>*, unsigned int r_type
);
583 unsupported_reloc_global(Sized_relobj_file
<32, false>*, unsigned int r_type
,
587 // The class which implements relocation.
592 : skip_call_tls_get_addr_(false),
593 local_dynamic_type_(LOCAL_DYNAMIC_NONE
)
598 if (this->skip_call_tls_get_addr_
)
600 // FIXME: This needs to specify the location somehow.
601 gold_error(_("missing expected TLS relocation"));
605 // Return whether the static relocation needs to be applied.
607 should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
610 Output_section
* output_section
);
612 // Do a relocation. Return false if the caller should not issue
613 // any warnings about this relocation.
615 relocate(const Relocate_info
<32, false>*, Target_i386
*, Output_section
*,
616 size_t relnum
, const elfcpp::Rel
<32, false>&,
617 unsigned int r_type
, const Sized_symbol
<32>*,
618 const Symbol_value
<32>*,
619 unsigned char*, elfcpp::Elf_types
<32>::Elf_Addr
,
623 // Do a TLS relocation.
625 relocate_tls(const Relocate_info
<32, false>*, Target_i386
* target
,
626 size_t relnum
, const elfcpp::Rel
<32, false>&,
627 unsigned int r_type
, const Sized_symbol
<32>*,
628 const Symbol_value
<32>*,
629 unsigned char*, elfcpp::Elf_types
<32>::Elf_Addr
,
632 // Do a TLS General-Dynamic to Initial-Exec transition.
634 tls_gd_to_ie(const Relocate_info
<32, false>*, size_t relnum
,
635 Output_segment
* tls_segment
,
636 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
637 elfcpp::Elf_types
<32>::Elf_Addr value
,
639 section_size_type view_size
);
641 // Do a TLS General-Dynamic to Local-Exec transition.
643 tls_gd_to_le(const Relocate_info
<32, false>*, size_t relnum
,
644 Output_segment
* tls_segment
,
645 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
646 elfcpp::Elf_types
<32>::Elf_Addr value
,
648 section_size_type view_size
);
650 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
653 tls_desc_gd_to_ie(const Relocate_info
<32, false>*, size_t relnum
,
654 Output_segment
* tls_segment
,
655 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
656 elfcpp::Elf_types
<32>::Elf_Addr value
,
658 section_size_type view_size
);
660 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
663 tls_desc_gd_to_le(const Relocate_info
<32, false>*, size_t relnum
,
664 Output_segment
* tls_segment
,
665 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
666 elfcpp::Elf_types
<32>::Elf_Addr value
,
668 section_size_type view_size
);
670 // Do a TLS Local-Dynamic to Local-Exec transition.
672 tls_ld_to_le(const Relocate_info
<32, false>*, size_t relnum
,
673 Output_segment
* tls_segment
,
674 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
675 elfcpp::Elf_types
<32>::Elf_Addr value
,
677 section_size_type view_size
);
679 // Do a TLS Initial-Exec to Local-Exec transition.
681 tls_ie_to_le(const Relocate_info
<32, false>*, size_t relnum
,
682 Output_segment
* tls_segment
,
683 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
684 elfcpp::Elf_types
<32>::Elf_Addr value
,
686 section_size_type view_size
);
688 // We need to keep track of which type of local dynamic relocation
689 // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
690 enum Local_dynamic_type
697 // This is set if we should skip the next reloc, which should be a
698 // PLT32 reloc against ___tls_get_addr.
699 bool skip_call_tls_get_addr_
;
700 // The type of local dynamic relocation we have seen in the section
701 // being relocated, if any.
702 Local_dynamic_type local_dynamic_type_
;
705 // A class which returns the size required for a relocation type,
706 // used while scanning relocs during a relocatable link.
707 class Relocatable_size_for_reloc
711 get_size_for_reloc(unsigned int, Relobj
*);
714 // Adjust TLS relocation type based on the options and whether this
715 // is a local symbol.
716 static tls::Tls_optimization
717 optimize_tls_reloc(bool is_final
, int r_type
);
719 // Get the GOT section, creating it if necessary.
720 Output_data_got
<32, false>*
721 got_section(Symbol_table
*, Layout
*);
723 // Get the GOT PLT section.
725 got_plt_section() const
727 gold_assert(this->got_plt_
!= NULL
);
728 return this->got_plt_
;
731 // Get the GOT section for TLSDESC entries.
732 Output_data_got
<32, false>*
733 got_tlsdesc_section() const
735 gold_assert(this->got_tlsdesc_
!= NULL
);
736 return this->got_tlsdesc_
;
739 // Create the PLT section.
741 make_plt_section(Symbol_table
* symtab
, Layout
* layout
);
743 // Create a PLT entry for a global symbol.
745 make_plt_entry(Symbol_table
*, Layout
*, Symbol
*);
747 // Create a PLT entry for a local STT_GNU_IFUNC symbol.
749 make_local_ifunc_plt_entry(Symbol_table
*, Layout
*,
750 Sized_relobj_file
<32, false>* relobj
,
751 unsigned int local_sym_index
);
753 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
755 define_tls_base_symbol(Symbol_table
*, Layout
*);
757 // Create a GOT entry for the TLS module index.
759 got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
760 Sized_relobj_file
<32, false>* object
);
762 // Get the PLT section.
763 Output_data_plt_i386
*
766 gold_assert(this->plt_
!= NULL
);
770 // Get the dynamic reloc section, creating it if necessary.
772 rel_dyn_section(Layout
*);
774 // Get the section to use for TLS_DESC relocations.
776 rel_tls_desc_section(Layout
*) const;
778 // Get the section to use for IRELATIVE relocations.
780 rel_irelative_section(Layout
*);
782 // Add a potential copy relocation.
784 copy_reloc(Symbol_table
* symtab
, Layout
* layout
,
785 Sized_relobj_file
<32, false>* object
,
786 unsigned int shndx
, Output_section
* output_section
,
787 Symbol
* sym
, const elfcpp::Rel
<32, false>& reloc
)
789 this->copy_relocs_
.copy_reloc(symtab
, layout
,
790 symtab
->get_sized_symbol
<32>(sym
),
791 object
, shndx
, output_section
, reloc
,
792 this->rel_dyn_section(layout
));
795 // Information about this specific target which we pass to the
796 // general Target structure.
797 static const Target::Target_info i386_info
;
799 // The types of GOT entries needed for this platform.
800 // These values are exposed to the ABI in an incremental link.
801 // Do not renumber existing values without changing the version
802 // number of the .gnu_incremental_inputs section.
805 GOT_TYPE_STANDARD
= 0, // GOT entry for a regular symbol
806 GOT_TYPE_TLS_NOFFSET
= 1, // GOT entry for negative TLS offset
807 GOT_TYPE_TLS_OFFSET
= 2, // GOT entry for positive TLS offset
808 GOT_TYPE_TLS_PAIR
= 3, // GOT entry for TLS module/offset pair
809 GOT_TYPE_TLS_DESC
= 4 // GOT entry for TLS_DESC pair
813 Output_data_got
<32, false>* got_
;
815 Output_data_plt_i386
* plt_
;
816 // The GOT PLT section.
817 Output_data_space
* got_plt_
;
818 // The GOT section for IRELATIVE relocations.
819 Output_data_space
* got_irelative_
;
820 // The GOT section for TLSDESC relocations.
821 Output_data_got
<32, false>* got_tlsdesc_
;
822 // The _GLOBAL_OFFSET_TABLE_ symbol.
823 Symbol
* global_offset_table_
;
824 // The dynamic reloc section.
825 Reloc_section
* rel_dyn_
;
826 // The section to use for IRELATIVE relocs.
827 Reloc_section
* rel_irelative_
;
828 // Relocs saved to avoid a COPY reloc.
829 Copy_relocs
<elfcpp::SHT_REL
, 32, false> copy_relocs_
;
830 // Offset of the GOT entry for the TLS module index.
831 unsigned int got_mod_index_offset_
;
832 // True if the _TLS_MODULE_BASE_ symbol has been defined.
833 bool tls_base_symbol_defined_
;
836 const Target::Target_info
Target_i386::i386_info
=
839 false, // is_big_endian
840 elfcpp::EM_386
, // machine_code
841 false, // has_make_symbol
842 false, // has_resolve
843 true, // has_code_fill
844 true, // is_default_stack_executable
845 true, // can_icf_inline_merge_sections
847 "/usr/lib/libc.so.1", // dynamic_linker
848 0x08048000, // default_text_segment_address
849 0x1000, // abi_pagesize (overridable by -z max-page-size)
850 0x1000, // common_pagesize (overridable by -z common-page-size)
851 false, // isolate_execinstr
853 elfcpp::SHN_UNDEF
, // small_common_shndx
854 elfcpp::SHN_UNDEF
, // large_common_shndx
855 0, // small_common_section_flags
856 0, // large_common_section_flags
857 NULL
, // attributes_section
858 NULL
, // attributes_vendor
859 "_start" // entry_symbol_name
862 // Get the GOT section, creating it if necessary.
864 Output_data_got
<32, false>*
865 Target_i386::got_section(Symbol_table
* symtab
, Layout
* layout
)
867 if (this->got_
== NULL
)
869 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
871 this->got_
= new Output_data_got
<32, false>();
873 // When using -z now, we can treat .got.plt as a relro section.
874 // Without -z now, it is modified after program startup by lazy
876 bool is_got_plt_relro
= parameters
->options().now();
877 Output_section_order got_order
= (is_got_plt_relro
880 Output_section_order got_plt_order
= (is_got_plt_relro
882 : ORDER_NON_RELRO_FIRST
);
884 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
886 | elfcpp::SHF_WRITE
),
887 this->got_
, got_order
, true);
889 this->got_plt_
= new Output_data_space(4, "** GOT PLT");
890 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
892 | elfcpp::SHF_WRITE
),
893 this->got_plt_
, got_plt_order
,
896 // The first three entries are reserved.
897 this->got_plt_
->set_current_data_size(3 * 4);
899 if (!is_got_plt_relro
)
901 // Those bytes can go into the relro segment.
902 layout
->increase_relro(3 * 4);
905 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
906 this->global_offset_table_
=
907 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
908 Symbol_table::PREDEFINED
,
910 0, 0, elfcpp::STT_OBJECT
,
912 elfcpp::STV_HIDDEN
, 0,
915 // If there are any IRELATIVE relocations, they get GOT entries
916 // in .got.plt after the jump slot relocations.
917 this->got_irelative_
= new Output_data_space(4, "** GOT IRELATIVE PLT");
918 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
920 | elfcpp::SHF_WRITE
),
921 this->got_irelative_
,
922 got_plt_order
, is_got_plt_relro
);
924 // If there are any TLSDESC relocations, they get GOT entries in
925 // .got.plt after the jump slot entries.
926 this->got_tlsdesc_
= new Output_data_got
<32, false>();
927 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
929 | elfcpp::SHF_WRITE
),
931 got_plt_order
, is_got_plt_relro
);
937 // Get the dynamic reloc section, creating it if necessary.
939 Target_i386::Reloc_section
*
940 Target_i386::rel_dyn_section(Layout
* layout
)
942 if (this->rel_dyn_
== NULL
)
944 gold_assert(layout
!= NULL
);
945 this->rel_dyn_
= new Reloc_section(parameters
->options().combreloc());
946 layout
->add_output_section_data(".rel.dyn", elfcpp::SHT_REL
,
947 elfcpp::SHF_ALLOC
, this->rel_dyn_
,
948 ORDER_DYNAMIC_RELOCS
, false);
950 return this->rel_dyn_
;
953 // Get the section to use for IRELATIVE relocs, creating it if
954 // necessary. These go in .rel.dyn, but only after all other dynamic
955 // relocations. They need to follow the other dynamic relocations so
956 // that they can refer to global variables initialized by those
959 Target_i386::Reloc_section
*
960 Target_i386::rel_irelative_section(Layout
* layout
)
962 if (this->rel_irelative_
== NULL
)
964 // Make sure we have already create the dynamic reloc section.
965 this->rel_dyn_section(layout
);
966 this->rel_irelative_
= new Reloc_section(false);
967 layout
->add_output_section_data(".rel.dyn", elfcpp::SHT_REL
,
968 elfcpp::SHF_ALLOC
, this->rel_irelative_
,
969 ORDER_DYNAMIC_RELOCS
, false);
970 gold_assert(this->rel_dyn_
->output_section()
971 == this->rel_irelative_
->output_section());
973 return this->rel_irelative_
;
976 // Create the PLT section. The ordinary .got section is an argument,
977 // since we need to refer to the start. We also create our own .got
978 // section just for PLT entries.
980 Output_data_plt_i386::Output_data_plt_i386(Layout
* layout
,
982 Output_data_space
* got_plt
,
983 Output_data_space
* got_irelative
)
984 : Output_section_data(addralign
),
985 layout_(layout
), tls_desc_rel_(NULL
),
986 irelative_rel_(NULL
), got_plt_(got_plt
), got_irelative_(got_irelative
),
987 count_(0), irelative_count_(0), global_ifuncs_(), local_ifuncs_()
989 this->rel_
= new Reloc_section(false);
990 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
991 elfcpp::SHF_ALLOC
, this->rel_
,
992 ORDER_DYNAMIC_PLT_RELOCS
, false);
996 Output_data_plt_i386::do_adjust_output_section(Output_section
* os
)
998 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
999 // linker, and so do we.
1003 // Add an entry to the PLT.
1006 Output_data_plt_i386::add_entry(Symbol_table
* symtab
, Layout
* layout
,
1009 gold_assert(!gsym
->has_plt_offset());
1011 // Every PLT entry needs a reloc.
1012 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1013 && gsym
->can_use_relative_reloc(false))
1015 gsym
->set_plt_offset(this->irelative_count_
* this->get_plt_entry_size());
1016 ++this->irelative_count_
;
1017 section_offset_type got_offset
=
1018 this->got_irelative_
->current_data_size();
1019 this->got_irelative_
->set_current_data_size(got_offset
+ 4);
1020 Reloc_section
* rel
= this->rel_irelative(symtab
, layout
);
1021 rel
->add_symbolless_global_addend(gsym
, elfcpp::R_386_IRELATIVE
,
1022 this->got_irelative_
, got_offset
);
1023 struct Global_ifunc gi
;
1025 gi
.got_offset
= got_offset
;
1026 this->global_ifuncs_
.push_back(gi
);
1030 // When setting the PLT offset we skip the initial reserved PLT
1032 gsym
->set_plt_offset((this->count_
+ 1) * this->get_plt_entry_size());
1036 section_offset_type got_offset
= this->got_plt_
->current_data_size();
1038 // Every PLT entry needs a GOT entry which points back to the
1039 // PLT entry (this will be changed by the dynamic linker,
1040 // normally lazily when the function is called).
1041 this->got_plt_
->set_current_data_size(got_offset
+ 4);
1043 gsym
->set_needs_dynsym_entry();
1044 this->rel_
->add_global(gsym
, elfcpp::R_386_JUMP_SLOT
, this->got_plt_
,
1048 // Note that we don't need to save the symbol. The contents of the
1049 // PLT are independent of which symbols are used. The symbols only
1050 // appear in the relocations.
1053 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
1057 Output_data_plt_i386::add_local_ifunc_entry(
1058 Symbol_table
* symtab
,
1060 Sized_relobj_file
<32, false>* relobj
,
1061 unsigned int local_sym_index
)
1063 unsigned int plt_offset
= this->irelative_count_
* this->get_plt_entry_size();
1064 ++this->irelative_count_
;
1066 section_offset_type got_offset
= this->got_irelative_
->current_data_size();
1068 // Every PLT entry needs a GOT entry which points back to the PLT
1070 this->got_irelative_
->set_current_data_size(got_offset
+ 4);
1072 // Every PLT entry needs a reloc.
1073 Reloc_section
* rel
= this->rel_irelative(symtab
, layout
);
1074 rel
->add_symbolless_local_addend(relobj
, local_sym_index
,
1075 elfcpp::R_386_IRELATIVE
,
1076 this->got_irelative_
, got_offset
);
1078 struct Local_ifunc li
;
1080 li
.local_sym_index
= local_sym_index
;
1081 li
.got_offset
= got_offset
;
1082 this->local_ifuncs_
.push_back(li
);
1087 // Return where the TLS_DESC relocations should go, creating it if
1088 // necessary. These follow the JUMP_SLOT relocations.
1090 Output_data_plt_i386::Reloc_section
*
1091 Output_data_plt_i386::rel_tls_desc(Layout
* layout
)
1093 if (this->tls_desc_rel_
== NULL
)
1095 this->tls_desc_rel_
= new Reloc_section(false);
1096 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
1097 elfcpp::SHF_ALLOC
, this->tls_desc_rel_
,
1098 ORDER_DYNAMIC_PLT_RELOCS
, false);
1099 gold_assert(this->tls_desc_rel_
->output_section()
1100 == this->rel_
->output_section());
1102 return this->tls_desc_rel_
;
1105 // Return where the IRELATIVE relocations should go in the PLT. These
1106 // follow the JUMP_SLOT and TLS_DESC relocations.
1108 Output_data_plt_i386::Reloc_section
*
1109 Output_data_plt_i386::rel_irelative(Symbol_table
* symtab
, Layout
* layout
)
1111 if (this->irelative_rel_
== NULL
)
1113 // Make sure we have a place for the TLS_DESC relocations, in
1114 // case we see any later on.
1115 this->rel_tls_desc(layout
);
1116 this->irelative_rel_
= new Reloc_section(false);
1117 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
1118 elfcpp::SHF_ALLOC
, this->irelative_rel_
,
1119 ORDER_DYNAMIC_PLT_RELOCS
, false);
1120 gold_assert(this->irelative_rel_
->output_section()
1121 == this->rel_
->output_section());
1123 if (parameters
->doing_static_link())
1125 // A statically linked executable will only have a .rel.plt
1126 // section to hold R_386_IRELATIVE relocs for STT_GNU_IFUNC
1127 // symbols. The library will use these symbols to locate
1128 // the IRELATIVE relocs at program startup time.
1129 symtab
->define_in_output_data("__rel_iplt_start", NULL
,
1130 Symbol_table::PREDEFINED
,
1131 this->irelative_rel_
, 0, 0,
1132 elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
1133 elfcpp::STV_HIDDEN
, 0, false, true);
1134 symtab
->define_in_output_data("__rel_iplt_end", NULL
,
1135 Symbol_table::PREDEFINED
,
1136 this->irelative_rel_
, 0, 0,
1137 elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
1138 elfcpp::STV_HIDDEN
, 0, true, true);
1141 return this->irelative_rel_
;
1144 // Return the PLT address to use for a global symbol.
1147 Output_data_plt_i386::address_for_global(const Symbol
* gsym
)
1149 uint64_t offset
= 0;
1150 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1151 && gsym
->can_use_relative_reloc(false))
1152 offset
= (this->count_
+ 1) * this->get_plt_entry_size();
1153 return this->address() + offset
+ gsym
->plt_offset();
1156 // Return the PLT address to use for a local symbol. These are always
1157 // IRELATIVE relocs.
1160 Output_data_plt_i386::address_for_local(const Relobj
* object
,
1163 return (this->address()
1164 + (this->count_
+ 1) * this->get_plt_entry_size()
1165 + object
->local_plt_offset(r_sym
));
1168 // The first entry in the PLT for an executable.
1170 const unsigned char Output_data_plt_i386_exec::first_plt_entry
[plt_entry_size
] =
1172 0xff, 0x35, // pushl contents of memory address
1173 0, 0, 0, 0, // replaced with address of .got + 4
1174 0xff, 0x25, // jmp indirect
1175 0, 0, 0, 0, // replaced with address of .got + 8
1176 0, 0, 0, 0 // unused
1180 Output_data_plt_i386_exec::do_fill_first_plt_entry(
1182 elfcpp::Elf_types
<32>::Elf_Addr got_address
)
1184 memcpy(pov
, first_plt_entry
, plt_entry_size
);
1185 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 4);
1186 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 8);
1189 // The first entry in the PLT for a shared object.
1191 const unsigned char Output_data_plt_i386_dyn::first_plt_entry
[plt_entry_size
] =
1193 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
1194 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
1195 0, 0, 0, 0 // unused
1199 Output_data_plt_i386_dyn::do_fill_first_plt_entry(
1201 elfcpp::Elf_types
<32>::Elf_Addr
)
1203 memcpy(pov
, first_plt_entry
, plt_entry_size
);
1206 // Subsequent entries in the PLT for an executable.
1208 const unsigned char Output_data_plt_i386_exec::plt_entry
[plt_entry_size
] =
1210 0xff, 0x25, // jmp indirect
1211 0, 0, 0, 0, // replaced with address of symbol in .got
1212 0x68, // pushl immediate
1213 0, 0, 0, 0, // replaced with offset into relocation table
1214 0xe9, // jmp relative
1215 0, 0, 0, 0 // replaced with offset to start of .plt
1219 Output_data_plt_i386_exec::do_fill_plt_entry(
1221 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
1222 unsigned int got_offset
,
1223 unsigned int plt_offset
,
1224 unsigned int plt_rel_offset
)
1226 memcpy(pov
, plt_entry
, plt_entry_size
);
1227 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
1228 got_address
+ got_offset
);
1229 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_rel_offset
);
1230 elfcpp::Swap
<32, false>::writeval(pov
+ 12, - (plt_offset
+ 12 + 4));
1234 // Subsequent entries in the PLT for a shared object.
1236 const unsigned char Output_data_plt_i386_dyn::plt_entry
[plt_entry_size
] =
1238 0xff, 0xa3, // jmp *offset(%ebx)
1239 0, 0, 0, 0, // replaced with offset of symbol in .got
1240 0x68, // pushl immediate
1241 0, 0, 0, 0, // replaced with offset into relocation table
1242 0xe9, // jmp relative
1243 0, 0, 0, 0 // replaced with offset to start of .plt
1247 Output_data_plt_i386_dyn::do_fill_plt_entry(unsigned char* pov
,
1248 elfcpp::Elf_types
<32>::Elf_Addr
,
1249 unsigned int got_offset
,
1250 unsigned int plt_offset
,
1251 unsigned int plt_rel_offset
)
1253 memcpy(pov
, plt_entry
, plt_entry_size
);
1254 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
1255 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_rel_offset
);
1256 elfcpp::Swap
<32, false>::writeval(pov
+ 12, - (plt_offset
+ 12 + 4));
1260 // The .eh_frame unwind information for the PLT.
1263 Output_data_plt_i386::plt_eh_frame_cie
[plt_eh_frame_cie_size
] =
1266 'z', // Augmentation: augmentation size included.
1267 'R', // Augmentation: FDE encoding included.
1268 '\0', // End of augmentation string.
1269 1, // Code alignment factor.
1270 0x7c, // Data alignment factor.
1271 8, // Return address column.
1272 1, // Augmentation size.
1273 (elfcpp::DW_EH_PE_pcrel
// FDE encoding.
1274 | elfcpp::DW_EH_PE_sdata4
),
1275 elfcpp::DW_CFA_def_cfa
, 4, 4, // DW_CFA_def_cfa: r4 (esp) ofs 4.
1276 elfcpp::DW_CFA_offset
+ 8, 1, // DW_CFA_offset: r8 (eip) at cfa-4.
1277 elfcpp::DW_CFA_nop
, // Align to 16 bytes.
1282 Output_data_plt_i386_standard::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
1284 0, 0, 0, 0, // Replaced with offset to .plt.
1285 0, 0, 0, 0, // Replaced with size of .plt.
1286 0, // Augmentation size.
1287 elfcpp::DW_CFA_def_cfa_offset
, 8, // DW_CFA_def_cfa_offset: 8.
1288 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
1289 elfcpp::DW_CFA_def_cfa_offset
, 12, // DW_CFA_def_cfa_offset: 12.
1290 elfcpp::DW_CFA_advance_loc
+ 10, // Advance 10 to __PLT__ + 16.
1291 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
1292 11, // Block length.
1293 elfcpp::DW_OP_breg4
, 4, // Push %esp + 4.
1294 elfcpp::DW_OP_breg8
, 0, // Push %eip.
1295 elfcpp::DW_OP_lit15
, // Push 0xf.
1296 elfcpp::DW_OP_and
, // & (%eip & 0xf).
1297 elfcpp::DW_OP_lit11
, // Push 0xb.
1298 elfcpp::DW_OP_ge
, // >= ((%eip & 0xf) >= 0xb)
1299 elfcpp::DW_OP_lit2
, // Push 2.
1300 elfcpp::DW_OP_shl
, // << (((%eip & 0xf) >= 0xb) << 2)
1301 elfcpp::DW_OP_plus
, // + ((((%eip&0xf)>=0xb)<<2)+%esp+4
1302 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
1308 // Write out the PLT. This uses the hand-coded instructions above,
1309 // and adjusts them as needed. This is all specified by the i386 ELF
1310 // Processor Supplement.
1313 Output_data_plt_i386::do_write(Output_file
* of
)
1315 const off_t offset
= this->offset();
1316 const section_size_type oview_size
=
1317 convert_to_section_size_type(this->data_size());
1318 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
1320 const off_t got_file_offset
= this->got_plt_
->offset();
1321 gold_assert(parameters
->incremental_update()
1322 || (got_file_offset
+ this->got_plt_
->data_size()
1323 == this->got_irelative_
->offset()));
1324 const section_size_type got_size
=
1325 convert_to_section_size_type(this->got_plt_
->data_size()
1326 + this->got_irelative_
->data_size());
1327 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
1330 unsigned char* pov
= oview
;
1332 elfcpp::Elf_types
<32>::Elf_Addr plt_address
= this->address();
1333 elfcpp::Elf_types
<32>::Elf_Addr got_address
= this->got_plt_
->address();
1335 this->fill_first_plt_entry(pov
, got_address
);
1336 pov
+= this->get_plt_entry_size();
1338 unsigned char* got_pov
= got_view
;
1340 // The first entry in the GOT is the address of the .dynamic section
1341 // aka the PT_DYNAMIC segment. The next two entries are reserved.
1342 // We saved space for them when we created the section in
1343 // Target_i386::got_section.
1344 Output_section
* dynamic
= this->layout_
->dynamic_section();
1345 uint32_t dynamic_addr
= dynamic
== NULL
? 0 : dynamic
->address();
1346 elfcpp::Swap
<32, false>::writeval(got_pov
, dynamic_addr
);
1348 memset(got_pov
, 0, 8);
1351 const int rel_size
= elfcpp::Elf_sizes
<32>::rel_size
;
1353 unsigned int plt_offset
= this->get_plt_entry_size();
1354 unsigned int plt_rel_offset
= 0;
1355 unsigned int got_offset
= 12;
1356 const unsigned int count
= this->count_
+ this->irelative_count_
;
1357 for (unsigned int i
= 0;
1360 pov
+= this->get_plt_entry_size(),
1362 plt_offset
+= this->get_plt_entry_size(),
1363 plt_rel_offset
+= rel_size
,
1366 // Set and adjust the PLT entry itself.
1367 unsigned int lazy_offset
= this->fill_plt_entry(pov
,
1373 // Set the entry in the GOT.
1374 elfcpp::Swap
<32, false>::writeval(got_pov
,
1375 plt_address
+ plt_offset
+ lazy_offset
);
1378 // If any STT_GNU_IFUNC symbols have PLT entries, we need to change
1379 // the GOT to point to the actual symbol value, rather than point to
1380 // the PLT entry. That will let the dynamic linker call the right
1381 // function when resolving IRELATIVE relocations.
1382 unsigned char* got_irelative_view
= got_view
+ this->got_plt_
->data_size();
1383 for (std::vector
<Global_ifunc
>::const_iterator p
=
1384 this->global_ifuncs_
.begin();
1385 p
!= this->global_ifuncs_
.end();
1388 const Sized_symbol
<32>* ssym
=
1389 static_cast<const Sized_symbol
<32>*>(p
->sym
);
1390 elfcpp::Swap
<32, false>::writeval(got_irelative_view
+ p
->got_offset
,
1394 for (std::vector
<Local_ifunc
>::const_iterator p
=
1395 this->local_ifuncs_
.begin();
1396 p
!= this->local_ifuncs_
.end();
1399 const Symbol_value
<32>* psymval
=
1400 p
->object
->local_symbol(p
->local_sym_index
);
1401 elfcpp::Swap
<32, false>::writeval(got_irelative_view
+ p
->got_offset
,
1402 psymval
->value(p
->object
, 0));
1405 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
1406 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
1408 of
->write_output_view(offset
, oview_size
, oview
);
1409 of
->write_output_view(got_file_offset
, got_size
, got_view
);
1412 // Create the PLT section.
1415 Target_i386::make_plt_section(Symbol_table
* symtab
, Layout
* layout
)
1417 if (this->plt_
== NULL
)
1419 // Create the GOT sections first.
1420 this->got_section(symtab
, layout
);
1422 const bool dyn
= parameters
->options().output_is_position_independent();
1423 this->plt_
= this->make_data_plt(layout
,
1425 this->got_irelative_
,
1428 // Add unwind information if requested.
1429 if (parameters
->options().ld_generated_unwind_info())
1430 this->plt_
->add_eh_frame(layout
);
1432 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
1434 | elfcpp::SHF_EXECINSTR
),
1435 this->plt_
, ORDER_PLT
, false);
1437 // Make the sh_info field of .rel.plt point to .plt.
1438 Output_section
* rel_plt_os
= this->plt_
->rel_plt()->output_section();
1439 rel_plt_os
->set_info_section(this->plt_
->output_section());
1443 // Create a PLT entry for a global symbol.
1446 Target_i386::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
, Symbol
* gsym
)
1448 if (gsym
->has_plt_offset())
1450 if (this->plt_
== NULL
)
1451 this->make_plt_section(symtab
, layout
);
1452 this->plt_
->add_entry(symtab
, layout
, gsym
);
1455 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1458 Target_i386::make_local_ifunc_plt_entry(Symbol_table
* symtab
, Layout
* layout
,
1459 Sized_relobj_file
<32, false>* relobj
,
1460 unsigned int local_sym_index
)
1462 if (relobj
->local_has_plt_offset(local_sym_index
))
1464 if (this->plt_
== NULL
)
1465 this->make_plt_section(symtab
, layout
);
1466 unsigned int plt_offset
= this->plt_
->add_local_ifunc_entry(symtab
, layout
,
1469 relobj
->set_local_plt_offset(local_sym_index
, plt_offset
);
1472 // Return the number of entries in the PLT.
1475 Target_i386::plt_entry_count() const
1477 if (this->plt_
== NULL
)
1479 return this->plt_
->entry_count();
1482 // Return the offset of the first non-reserved PLT entry.
1485 Target_i386::first_plt_entry_offset() const
1487 return this->plt_
->first_plt_entry_offset();
1490 // Return the size of each PLT entry.
1493 Target_i386::plt_entry_size() const
1495 return this->plt_
->get_plt_entry_size();
1498 // Get the section to use for TLS_DESC relocations.
1500 Target_i386::Reloc_section
*
1501 Target_i386::rel_tls_desc_section(Layout
* layout
) const
1503 return this->plt_section()->rel_tls_desc(layout
);
1506 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1509 Target_i386::define_tls_base_symbol(Symbol_table
* symtab
, Layout
* layout
)
1511 if (this->tls_base_symbol_defined_
)
1514 Output_segment
* tls_segment
= layout
->tls_segment();
1515 if (tls_segment
!= NULL
)
1517 bool is_exec
= parameters
->options().output_is_executable();
1518 symtab
->define_in_output_segment("_TLS_MODULE_BASE_", NULL
,
1519 Symbol_table::PREDEFINED
,
1523 elfcpp::STV_HIDDEN
, 0,
1525 ? Symbol::SEGMENT_END
1526 : Symbol::SEGMENT_START
),
1529 this->tls_base_symbol_defined_
= true;
1532 // Create a GOT entry for the TLS module index.
1535 Target_i386::got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
1536 Sized_relobj_file
<32, false>* object
)
1538 if (this->got_mod_index_offset_
== -1U)
1540 gold_assert(symtab
!= NULL
&& layout
!= NULL
&& object
!= NULL
);
1541 Reloc_section
* rel_dyn
= this->rel_dyn_section(layout
);
1542 Output_data_got
<32, false>* got
= this->got_section(symtab
, layout
);
1543 unsigned int got_offset
= got
->add_constant(0);
1544 rel_dyn
->add_local(object
, 0, elfcpp::R_386_TLS_DTPMOD32
, got
,
1546 got
->add_constant(0);
1547 this->got_mod_index_offset_
= got_offset
;
1549 return this->got_mod_index_offset_
;
1552 // Optimize the TLS relocation type based on what we know about the
1553 // symbol. IS_FINAL is true if the final address of this symbol is
1554 // known at link time.
1556 tls::Tls_optimization
1557 Target_i386::optimize_tls_reloc(bool is_final
, int r_type
)
1559 // If we are generating a shared library, then we can't do anything
1561 if (parameters
->options().shared())
1562 return tls::TLSOPT_NONE
;
1566 case elfcpp::R_386_TLS_GD
:
1567 case elfcpp::R_386_TLS_GOTDESC
:
1568 case elfcpp::R_386_TLS_DESC_CALL
:
1569 // These are General-Dynamic which permits fully general TLS
1570 // access. Since we know that we are generating an executable,
1571 // we can convert this to Initial-Exec. If we also know that
1572 // this is a local symbol, we can further switch to Local-Exec.
1574 return tls::TLSOPT_TO_LE
;
1575 return tls::TLSOPT_TO_IE
;
1577 case elfcpp::R_386_TLS_LDM
:
1578 // This is Local-Dynamic, which refers to a local symbol in the
1579 // dynamic TLS block. Since we know that we generating an
1580 // executable, we can switch to Local-Exec.
1581 return tls::TLSOPT_TO_LE
;
1583 case elfcpp::R_386_TLS_LDO_32
:
1584 // Another type of Local-Dynamic relocation.
1585 return tls::TLSOPT_TO_LE
;
1587 case elfcpp::R_386_TLS_IE
:
1588 case elfcpp::R_386_TLS_GOTIE
:
1589 case elfcpp::R_386_TLS_IE_32
:
1590 // These are Initial-Exec relocs which get the thread offset
1591 // from the GOT. If we know that we are linking against the
1592 // local symbol, we can switch to Local-Exec, which links the
1593 // thread offset into the instruction.
1595 return tls::TLSOPT_TO_LE
;
1596 return tls::TLSOPT_NONE
;
1598 case elfcpp::R_386_TLS_LE
:
1599 case elfcpp::R_386_TLS_LE_32
:
1600 // When we already have Local-Exec, there is nothing further we
1602 return tls::TLSOPT_NONE
;
1609 // Get the Reference_flags for a particular relocation.
1612 Target_i386::Scan::get_reference_flags(unsigned int r_type
)
1616 case elfcpp::R_386_NONE
:
1617 case elfcpp::R_386_GNU_VTINHERIT
:
1618 case elfcpp::R_386_GNU_VTENTRY
:
1619 case elfcpp::R_386_GOTPC
:
1620 // No symbol reference.
1623 case elfcpp::R_386_32
:
1624 case elfcpp::R_386_16
:
1625 case elfcpp::R_386_8
:
1626 return Symbol::ABSOLUTE_REF
;
1628 case elfcpp::R_386_PC32
:
1629 case elfcpp::R_386_PC16
:
1630 case elfcpp::R_386_PC8
:
1631 case elfcpp::R_386_GOTOFF
:
1632 return Symbol::RELATIVE_REF
;
1634 case elfcpp::R_386_PLT32
:
1635 return Symbol::FUNCTION_CALL
| Symbol::RELATIVE_REF
;
1637 case elfcpp::R_386_GOT32
:
1639 return Symbol::ABSOLUTE_REF
;
1641 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1642 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1643 case elfcpp::R_386_TLS_DESC_CALL
:
1644 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1645 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1646 case elfcpp::R_386_TLS_IE
: // Initial-exec
1647 case elfcpp::R_386_TLS_IE_32
:
1648 case elfcpp::R_386_TLS_GOTIE
:
1649 case elfcpp::R_386_TLS_LE
: // Local-exec
1650 case elfcpp::R_386_TLS_LE_32
:
1651 return Symbol::TLS_REF
;
1653 case elfcpp::R_386_COPY
:
1654 case elfcpp::R_386_GLOB_DAT
:
1655 case elfcpp::R_386_JUMP_SLOT
:
1656 case elfcpp::R_386_RELATIVE
:
1657 case elfcpp::R_386_IRELATIVE
:
1658 case elfcpp::R_386_TLS_TPOFF
:
1659 case elfcpp::R_386_TLS_DTPMOD32
:
1660 case elfcpp::R_386_TLS_DTPOFF32
:
1661 case elfcpp::R_386_TLS_TPOFF32
:
1662 case elfcpp::R_386_TLS_DESC
:
1663 case elfcpp::R_386_32PLT
:
1664 case elfcpp::R_386_TLS_GD_32
:
1665 case elfcpp::R_386_TLS_GD_PUSH
:
1666 case elfcpp::R_386_TLS_GD_CALL
:
1667 case elfcpp::R_386_TLS_GD_POP
:
1668 case elfcpp::R_386_TLS_LDM_32
:
1669 case elfcpp::R_386_TLS_LDM_PUSH
:
1670 case elfcpp::R_386_TLS_LDM_CALL
:
1671 case elfcpp::R_386_TLS_LDM_POP
:
1672 case elfcpp::R_386_USED_BY_INTEL_200
:
1674 // Not expected. We will give an error later.
1679 // Report an unsupported relocation against a local symbol.
1682 Target_i386::Scan::unsupported_reloc_local(Sized_relobj_file
<32, false>* object
,
1683 unsigned int r_type
)
1685 gold_error(_("%s: unsupported reloc %u against local symbol"),
1686 object
->name().c_str(), r_type
);
1689 // Return whether we need to make a PLT entry for a relocation of a
1690 // given type against a STT_GNU_IFUNC symbol.
1693 Target_i386::Scan::reloc_needs_plt_for_ifunc(
1694 Sized_relobj_file
<32, false>* object
,
1695 unsigned int r_type
)
1697 int flags
= Scan::get_reference_flags(r_type
);
1698 if (flags
& Symbol::TLS_REF
)
1699 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
1700 object
->name().c_str(), r_type
);
1704 // Scan a relocation for a local symbol.
1707 Target_i386::Scan::local(Symbol_table
* symtab
,
1709 Target_i386
* target
,
1710 Sized_relobj_file
<32, false>* object
,
1711 unsigned int data_shndx
,
1712 Output_section
* output_section
,
1713 const elfcpp::Rel
<32, false>& reloc
,
1714 unsigned int r_type
,
1715 const elfcpp::Sym
<32, false>& lsym
,
1721 // A local STT_GNU_IFUNC symbol may require a PLT entry.
1722 if (lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
1723 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
1725 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1726 target
->make_local_ifunc_plt_entry(symtab
, layout
, object
, r_sym
);
1731 case elfcpp::R_386_NONE
:
1732 case elfcpp::R_386_GNU_VTINHERIT
:
1733 case elfcpp::R_386_GNU_VTENTRY
:
1736 case elfcpp::R_386_32
:
1737 // If building a shared library (or a position-independent
1738 // executable), we need to create a dynamic relocation for
1739 // this location. The relocation applied at link time will
1740 // apply the link-time value, so we flag the location with
1741 // an R_386_RELATIVE relocation so the dynamic loader can
1742 // relocate it easily.
1743 if (parameters
->options().output_is_position_independent())
1745 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1746 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1747 rel_dyn
->add_local_relative(object
, r_sym
, elfcpp::R_386_RELATIVE
,
1748 output_section
, data_shndx
,
1749 reloc
.get_r_offset());
1753 case elfcpp::R_386_16
:
1754 case elfcpp::R_386_8
:
1755 // If building a shared library (or a position-independent
1756 // executable), we need to create a dynamic relocation for
1757 // this location. Because the addend needs to remain in the
1758 // data section, we need to be careful not to apply this
1759 // relocation statically.
1760 if (parameters
->options().output_is_position_independent())
1762 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1763 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1764 if (lsym
.get_st_type() != elfcpp::STT_SECTION
)
1765 rel_dyn
->add_local(object
, r_sym
, r_type
, output_section
,
1766 data_shndx
, reloc
.get_r_offset());
1769 gold_assert(lsym
.get_st_value() == 0);
1770 unsigned int shndx
= lsym
.get_st_shndx();
1772 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
,
1775 object
->error(_("section symbol %u has bad shndx %u"),
1778 rel_dyn
->add_local_section(object
, shndx
,
1779 r_type
, output_section
,
1780 data_shndx
, reloc
.get_r_offset());
1785 case elfcpp::R_386_PC32
:
1786 case elfcpp::R_386_PC16
:
1787 case elfcpp::R_386_PC8
:
1790 case elfcpp::R_386_PLT32
:
1791 // Since we know this is a local symbol, we can handle this as a
1795 case elfcpp::R_386_GOTOFF
:
1796 case elfcpp::R_386_GOTPC
:
1797 // We need a GOT section.
1798 target
->got_section(symtab
, layout
);
1801 case elfcpp::R_386_GOT32
:
1803 // The symbol requires a GOT entry.
1804 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
1805 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1807 // For a STT_GNU_IFUNC symbol we want the PLT offset. That
1808 // lets function pointers compare correctly with shared
1809 // libraries. Otherwise we would need an IRELATIVE reloc.
1811 if (lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
)
1812 is_new
= got
->add_local_plt(object
, r_sym
, GOT_TYPE_STANDARD
);
1814 is_new
= got
->add_local(object
, r_sym
, GOT_TYPE_STANDARD
);
1817 // If we are generating a shared object, we need to add a
1818 // dynamic RELATIVE relocation for this symbol's GOT entry.
1819 if (parameters
->options().output_is_position_independent())
1821 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1822 unsigned int got_offset
=
1823 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
);
1824 rel_dyn
->add_local_relative(object
, r_sym
,
1825 elfcpp::R_386_RELATIVE
,
1832 // These are relocations which should only be seen by the
1833 // dynamic linker, and should never be seen here.
1834 case elfcpp::R_386_COPY
:
1835 case elfcpp::R_386_GLOB_DAT
:
1836 case elfcpp::R_386_JUMP_SLOT
:
1837 case elfcpp::R_386_RELATIVE
:
1838 case elfcpp::R_386_IRELATIVE
:
1839 case elfcpp::R_386_TLS_TPOFF
:
1840 case elfcpp::R_386_TLS_DTPMOD32
:
1841 case elfcpp::R_386_TLS_DTPOFF32
:
1842 case elfcpp::R_386_TLS_TPOFF32
:
1843 case elfcpp::R_386_TLS_DESC
:
1844 gold_error(_("%s: unexpected reloc %u in object file"),
1845 object
->name().c_str(), r_type
);
1848 // These are initial TLS relocs, which are expected when
1850 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1851 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1852 case elfcpp::R_386_TLS_DESC_CALL
:
1853 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1854 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1855 case elfcpp::R_386_TLS_IE
: // Initial-exec
1856 case elfcpp::R_386_TLS_IE_32
:
1857 case elfcpp::R_386_TLS_GOTIE
:
1858 case elfcpp::R_386_TLS_LE
: // Local-exec
1859 case elfcpp::R_386_TLS_LE_32
:
1861 bool output_is_shared
= parameters
->options().shared();
1862 const tls::Tls_optimization optimized_type
1863 = Target_i386::optimize_tls_reloc(!output_is_shared
, r_type
);
1866 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1867 if (optimized_type
== tls::TLSOPT_NONE
)
1869 // Create a pair of GOT entries for the module index and
1870 // dtv-relative offset.
1871 Output_data_got
<32, false>* got
1872 = target
->got_section(symtab
, layout
);
1873 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1874 unsigned int shndx
= lsym
.get_st_shndx();
1876 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
1878 object
->error(_("local symbol %u has bad shndx %u"),
1881 got
->add_local_pair_with_rel(object
, r_sym
, shndx
,
1883 target
->rel_dyn_section(layout
),
1884 elfcpp::R_386_TLS_DTPMOD32
);
1886 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1887 unsupported_reloc_local(object
, r_type
);
1890 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva)
1891 target
->define_tls_base_symbol(symtab
, layout
);
1892 if (optimized_type
== tls::TLSOPT_NONE
)
1894 // Create a double GOT entry with an R_386_TLS_DESC
1895 // reloc. The R_386_TLS_DESC reloc is resolved
1896 // lazily, so the GOT entry needs to be in an area in
1897 // .got.plt, not .got. Call got_section to make sure
1898 // the section has been created.
1899 target
->got_section(symtab
, layout
);
1900 Output_data_got
<32, false>* got
= target
->got_tlsdesc_section();
1901 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1902 if (!object
->local_has_got_offset(r_sym
, GOT_TYPE_TLS_DESC
))
1904 unsigned int got_offset
= got
->add_constant(0);
1905 // The local symbol value is stored in the second
1907 got
->add_local(object
, r_sym
, GOT_TYPE_TLS_DESC
);
1908 // That set the GOT offset of the local symbol to
1909 // point to the second entry, but we want it to
1910 // point to the first.
1911 object
->set_local_got_offset(r_sym
, GOT_TYPE_TLS_DESC
,
1913 Reloc_section
* rt
= target
->rel_tls_desc_section(layout
);
1914 rt
->add_absolute(elfcpp::R_386_TLS_DESC
, got
, got_offset
);
1917 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1918 unsupported_reloc_local(object
, r_type
);
1921 case elfcpp::R_386_TLS_DESC_CALL
:
1924 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1925 if (optimized_type
== tls::TLSOPT_NONE
)
1927 // Create a GOT entry for the module index.
1928 target
->got_mod_index_entry(symtab
, layout
, object
);
1930 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1931 unsupported_reloc_local(object
, r_type
);
1934 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1937 case elfcpp::R_386_TLS_IE
: // Initial-exec
1938 case elfcpp::R_386_TLS_IE_32
:
1939 case elfcpp::R_386_TLS_GOTIE
:
1940 layout
->set_has_static_tls();
1941 if (optimized_type
== tls::TLSOPT_NONE
)
1943 // For the R_386_TLS_IE relocation, we need to create a
1944 // dynamic relocation when building a shared library.
1945 if (r_type
== elfcpp::R_386_TLS_IE
1946 && parameters
->options().shared())
1948 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1950 = elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1951 rel_dyn
->add_local_relative(object
, r_sym
,
1952 elfcpp::R_386_RELATIVE
,
1953 output_section
, data_shndx
,
1954 reloc
.get_r_offset());
1956 // Create a GOT entry for the tp-relative offset.
1957 Output_data_got
<32, false>* got
1958 = target
->got_section(symtab
, layout
);
1959 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1960 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1961 ? elfcpp::R_386_TLS_TPOFF32
1962 : elfcpp::R_386_TLS_TPOFF
);
1963 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
1964 ? GOT_TYPE_TLS_OFFSET
1965 : GOT_TYPE_TLS_NOFFSET
);
1966 got
->add_local_with_rel(object
, r_sym
, got_type
,
1967 target
->rel_dyn_section(layout
),
1970 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1971 unsupported_reloc_local(object
, r_type
);
1974 case elfcpp::R_386_TLS_LE
: // Local-exec
1975 case elfcpp::R_386_TLS_LE_32
:
1976 layout
->set_has_static_tls();
1977 if (output_is_shared
)
1979 // We need to create a dynamic relocation.
1980 gold_assert(lsym
.get_st_type() != elfcpp::STT_SECTION
);
1981 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1982 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
1983 ? elfcpp::R_386_TLS_TPOFF32
1984 : elfcpp::R_386_TLS_TPOFF
);
1985 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1986 rel_dyn
->add_local(object
, r_sym
, dyn_r_type
, output_section
,
1987 data_shndx
, reloc
.get_r_offset());
1997 case elfcpp::R_386_32PLT
:
1998 case elfcpp::R_386_TLS_GD_32
:
1999 case elfcpp::R_386_TLS_GD_PUSH
:
2000 case elfcpp::R_386_TLS_GD_CALL
:
2001 case elfcpp::R_386_TLS_GD_POP
:
2002 case elfcpp::R_386_TLS_LDM_32
:
2003 case elfcpp::R_386_TLS_LDM_PUSH
:
2004 case elfcpp::R_386_TLS_LDM_CALL
:
2005 case elfcpp::R_386_TLS_LDM_POP
:
2006 case elfcpp::R_386_USED_BY_INTEL_200
:
2008 unsupported_reloc_local(object
, r_type
);
2013 // Report an unsupported relocation against a global symbol.
2016 Target_i386::Scan::unsupported_reloc_global(
2017 Sized_relobj_file
<32, false>* object
,
2018 unsigned int r_type
,
2021 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
2022 object
->name().c_str(), r_type
, gsym
->demangled_name().c_str());
2026 Target_i386::Scan::possible_function_pointer_reloc(unsigned int r_type
)
2030 case elfcpp::R_386_32
:
2031 case elfcpp::R_386_16
:
2032 case elfcpp::R_386_8
:
2033 case elfcpp::R_386_GOTOFF
:
2034 case elfcpp::R_386_GOT32
:
2045 Target_i386::Scan::local_reloc_may_be_function_pointer(
2049 Sized_relobj_file
<32, false>* ,
2052 const elfcpp::Rel
<32, false>& ,
2053 unsigned int r_type
,
2054 const elfcpp::Sym
<32, false>&)
2056 return possible_function_pointer_reloc(r_type
);
2060 Target_i386::Scan::global_reloc_may_be_function_pointer(
2064 Sized_relobj_file
<32, false>* ,
2067 const elfcpp::Rel
<32, false>& ,
2068 unsigned int r_type
,
2071 return possible_function_pointer_reloc(r_type
);
2074 // Scan a relocation for a global symbol.
2077 Target_i386::Scan::global(Symbol_table
* symtab
,
2079 Target_i386
* target
,
2080 Sized_relobj_file
<32, false>* object
,
2081 unsigned int data_shndx
,
2082 Output_section
* output_section
,
2083 const elfcpp::Rel
<32, false>& reloc
,
2084 unsigned int r_type
,
2087 // A STT_GNU_IFUNC symbol may require a PLT entry.
2088 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
2089 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
2090 target
->make_plt_entry(symtab
, layout
, gsym
);
2094 case elfcpp::R_386_NONE
:
2095 case elfcpp::R_386_GNU_VTINHERIT
:
2096 case elfcpp::R_386_GNU_VTENTRY
:
2099 case elfcpp::R_386_32
:
2100 case elfcpp::R_386_16
:
2101 case elfcpp::R_386_8
:
2103 // Make a PLT entry if necessary.
2104 if (gsym
->needs_plt_entry())
2106 target
->make_plt_entry(symtab
, layout
, gsym
);
2107 // Since this is not a PC-relative relocation, we may be
2108 // taking the address of a function. In that case we need to
2109 // set the entry in the dynamic symbol table to the address of
2111 if (gsym
->is_from_dynobj() && !parameters
->options().shared())
2112 gsym
->set_needs_dynsym_value();
2114 // Make a dynamic relocation if necessary.
2115 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
2117 if (gsym
->may_need_copy_reloc())
2119 target
->copy_reloc(symtab
, layout
, object
,
2120 data_shndx
, output_section
, gsym
, reloc
);
2122 else if (r_type
== elfcpp::R_386_32
2123 && gsym
->type() == elfcpp::STT_GNU_IFUNC
2124 && gsym
->can_use_relative_reloc(false)
2125 && !gsym
->is_from_dynobj()
2126 && !gsym
->is_undefined()
2127 && !gsym
->is_preemptible())
2129 // Use an IRELATIVE reloc for a locally defined
2130 // STT_GNU_IFUNC symbol. This makes a function
2131 // address in a PIE executable match the address in a
2132 // shared library that it links against.
2133 Reloc_section
* rel_dyn
= target
->rel_irelative_section(layout
);
2134 rel_dyn
->add_symbolless_global_addend(gsym
,
2135 elfcpp::R_386_IRELATIVE
,
2138 reloc
.get_r_offset());
2140 else if (r_type
== elfcpp::R_386_32
2141 && gsym
->can_use_relative_reloc(false))
2143 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2144 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
2145 output_section
, object
,
2146 data_shndx
, reloc
.get_r_offset());
2150 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2151 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
2152 data_shndx
, reloc
.get_r_offset());
2158 case elfcpp::R_386_PC32
:
2159 case elfcpp::R_386_PC16
:
2160 case elfcpp::R_386_PC8
:
2162 // Make a PLT entry if necessary.
2163 if (gsym
->needs_plt_entry())
2165 // These relocations are used for function calls only in
2166 // non-PIC code. For a 32-bit relocation in a shared library,
2167 // we'll need a text relocation anyway, so we can skip the
2168 // PLT entry and let the dynamic linker bind the call directly
2169 // to the target. For smaller relocations, we should use a
2170 // PLT entry to ensure that the call can reach.
2171 if (!parameters
->options().shared()
2172 || r_type
!= elfcpp::R_386_PC32
)
2173 target
->make_plt_entry(symtab
, layout
, gsym
);
2175 // Make a dynamic relocation if necessary.
2176 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
2178 if (gsym
->may_need_copy_reloc())
2180 target
->copy_reloc(symtab
, layout
, object
,
2181 data_shndx
, output_section
, gsym
, reloc
);
2185 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2186 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
2187 data_shndx
, reloc
.get_r_offset());
2193 case elfcpp::R_386_GOT32
:
2195 // The symbol requires a GOT entry.
2196 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
2197 if (gsym
->final_value_is_known())
2199 // For a STT_GNU_IFUNC symbol we want the PLT address.
2200 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
)
2201 got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
2203 got
->add_global(gsym
, GOT_TYPE_STANDARD
);
2207 // If this symbol is not fully resolved, we need to add a
2208 // GOT entry with a dynamic relocation.
2209 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2211 // Use a GLOB_DAT rather than a RELATIVE reloc if:
2213 // 1) The symbol may be defined in some other module.
2215 // 2) We are building a shared library and this is a
2216 // protected symbol; using GLOB_DAT means that the dynamic
2217 // linker can use the address of the PLT in the main
2218 // executable when appropriate so that function address
2219 // comparisons work.
2221 // 3) This is a STT_GNU_IFUNC symbol in position dependent
2222 // code, again so that function address comparisons work.
2223 if (gsym
->is_from_dynobj()
2224 || gsym
->is_undefined()
2225 || gsym
->is_preemptible()
2226 || (gsym
->visibility() == elfcpp::STV_PROTECTED
2227 && parameters
->options().shared())
2228 || (gsym
->type() == elfcpp::STT_GNU_IFUNC
2229 && parameters
->options().output_is_position_independent()))
2230 got
->add_global_with_rel(gsym
, GOT_TYPE_STANDARD
,
2231 rel_dyn
, elfcpp::R_386_GLOB_DAT
);
2234 // For a STT_GNU_IFUNC symbol we want to write the PLT
2235 // offset into the GOT, so that function pointer
2236 // comparisons work correctly.
2238 if (gsym
->type() != elfcpp::STT_GNU_IFUNC
)
2239 is_new
= got
->add_global(gsym
, GOT_TYPE_STANDARD
);
2242 is_new
= got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
2243 // Tell the dynamic linker to use the PLT address
2244 // when resolving relocations.
2245 if (gsym
->is_from_dynobj()
2246 && !parameters
->options().shared())
2247 gsym
->set_needs_dynsym_value();
2251 unsigned int got_off
= gsym
->got_offset(GOT_TYPE_STANDARD
);
2252 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
2260 case elfcpp::R_386_PLT32
:
2261 // If the symbol is fully resolved, this is just a PC32 reloc.
2262 // Otherwise we need a PLT entry.
2263 if (gsym
->final_value_is_known())
2265 // If building a shared library, we can also skip the PLT entry
2266 // if the symbol is defined in the output file and is protected
2268 if (gsym
->is_defined()
2269 && !gsym
->is_from_dynobj()
2270 && !gsym
->is_preemptible())
2272 target
->make_plt_entry(symtab
, layout
, gsym
);
2275 case elfcpp::R_386_GOTOFF
:
2276 case elfcpp::R_386_GOTPC
:
2277 // We need a GOT section.
2278 target
->got_section(symtab
, layout
);
2281 // These are relocations which should only be seen by the
2282 // dynamic linker, and should never be seen here.
2283 case elfcpp::R_386_COPY
:
2284 case elfcpp::R_386_GLOB_DAT
:
2285 case elfcpp::R_386_JUMP_SLOT
:
2286 case elfcpp::R_386_RELATIVE
:
2287 case elfcpp::R_386_IRELATIVE
:
2288 case elfcpp::R_386_TLS_TPOFF
:
2289 case elfcpp::R_386_TLS_DTPMOD32
:
2290 case elfcpp::R_386_TLS_DTPOFF32
:
2291 case elfcpp::R_386_TLS_TPOFF32
:
2292 case elfcpp::R_386_TLS_DESC
:
2293 gold_error(_("%s: unexpected reloc %u in object file"),
2294 object
->name().c_str(), r_type
);
2297 // These are initial tls relocs, which are expected when
2299 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2300 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2301 case elfcpp::R_386_TLS_DESC_CALL
:
2302 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2303 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2304 case elfcpp::R_386_TLS_IE
: // Initial-exec
2305 case elfcpp::R_386_TLS_IE_32
:
2306 case elfcpp::R_386_TLS_GOTIE
:
2307 case elfcpp::R_386_TLS_LE
: // Local-exec
2308 case elfcpp::R_386_TLS_LE_32
:
2310 const bool is_final
= gsym
->final_value_is_known();
2311 const tls::Tls_optimization optimized_type
2312 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
2315 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2316 if (optimized_type
== tls::TLSOPT_NONE
)
2318 // Create a pair of GOT entries for the module index and
2319 // dtv-relative offset.
2320 Output_data_got
<32, false>* got
2321 = target
->got_section(symtab
, layout
);
2322 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_PAIR
,
2323 target
->rel_dyn_section(layout
),
2324 elfcpp::R_386_TLS_DTPMOD32
,
2325 elfcpp::R_386_TLS_DTPOFF32
);
2327 else if (optimized_type
== tls::TLSOPT_TO_IE
)
2329 // Create a GOT entry for the tp-relative offset.
2330 Output_data_got
<32, false>* got
2331 = target
->got_section(symtab
, layout
);
2332 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
2333 target
->rel_dyn_section(layout
),
2334 elfcpp::R_386_TLS_TPOFF
);
2336 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2337 unsupported_reloc_global(object
, r_type
, gsym
);
2340 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (~oliva url)
2341 target
->define_tls_base_symbol(symtab
, layout
);
2342 if (optimized_type
== tls::TLSOPT_NONE
)
2344 // Create a double GOT entry with an R_386_TLS_DESC
2345 // reloc. The R_386_TLS_DESC reloc is resolved
2346 // lazily, so the GOT entry needs to be in an area in
2347 // .got.plt, not .got. Call got_section to make sure
2348 // the section has been created.
2349 target
->got_section(symtab
, layout
);
2350 Output_data_got
<32, false>* got
= target
->got_tlsdesc_section();
2351 Reloc_section
* rt
= target
->rel_tls_desc_section(layout
);
2352 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_DESC
, rt
,
2353 elfcpp::R_386_TLS_DESC
, 0);
2355 else if (optimized_type
== tls::TLSOPT_TO_IE
)
2357 // Create a GOT entry for the tp-relative offset.
2358 Output_data_got
<32, false>* got
2359 = target
->got_section(symtab
, layout
);
2360 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
2361 target
->rel_dyn_section(layout
),
2362 elfcpp::R_386_TLS_TPOFF
);
2364 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2365 unsupported_reloc_global(object
, r_type
, gsym
);
2368 case elfcpp::R_386_TLS_DESC_CALL
:
2371 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2372 if (optimized_type
== tls::TLSOPT_NONE
)
2374 // Create a GOT entry for the module index.
2375 target
->got_mod_index_entry(symtab
, layout
, object
);
2377 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2378 unsupported_reloc_global(object
, r_type
, gsym
);
2381 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2384 case elfcpp::R_386_TLS_IE
: // Initial-exec
2385 case elfcpp::R_386_TLS_IE_32
:
2386 case elfcpp::R_386_TLS_GOTIE
:
2387 layout
->set_has_static_tls();
2388 if (optimized_type
== tls::TLSOPT_NONE
)
2390 // For the R_386_TLS_IE relocation, we need to create a
2391 // dynamic relocation when building a shared library.
2392 if (r_type
== elfcpp::R_386_TLS_IE
2393 && parameters
->options().shared())
2395 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2396 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
2397 output_section
, object
,
2399 reloc
.get_r_offset());
2401 // Create a GOT entry for the tp-relative offset.
2402 Output_data_got
<32, false>* got
2403 = target
->got_section(symtab
, layout
);
2404 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2405 ? elfcpp::R_386_TLS_TPOFF32
2406 : elfcpp::R_386_TLS_TPOFF
);
2407 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2408 ? GOT_TYPE_TLS_OFFSET
2409 : GOT_TYPE_TLS_NOFFSET
);
2410 got
->add_global_with_rel(gsym
, got_type
,
2411 target
->rel_dyn_section(layout
),
2414 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2415 unsupported_reloc_global(object
, r_type
, gsym
);
2418 case elfcpp::R_386_TLS_LE
: // Local-exec
2419 case elfcpp::R_386_TLS_LE_32
:
2420 layout
->set_has_static_tls();
2421 if (parameters
->options().shared())
2423 // We need to create a dynamic relocation.
2424 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
2425 ? elfcpp::R_386_TLS_TPOFF32
2426 : elfcpp::R_386_TLS_TPOFF
);
2427 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2428 rel_dyn
->add_global(gsym
, dyn_r_type
, output_section
, object
,
2429 data_shndx
, reloc
.get_r_offset());
2439 case elfcpp::R_386_32PLT
:
2440 case elfcpp::R_386_TLS_GD_32
:
2441 case elfcpp::R_386_TLS_GD_PUSH
:
2442 case elfcpp::R_386_TLS_GD_CALL
:
2443 case elfcpp::R_386_TLS_GD_POP
:
2444 case elfcpp::R_386_TLS_LDM_32
:
2445 case elfcpp::R_386_TLS_LDM_PUSH
:
2446 case elfcpp::R_386_TLS_LDM_CALL
:
2447 case elfcpp::R_386_TLS_LDM_POP
:
2448 case elfcpp::R_386_USED_BY_INTEL_200
:
2450 unsupported_reloc_global(object
, r_type
, gsym
);
2455 // Process relocations for gc.
2458 Target_i386::gc_process_relocs(Symbol_table
* symtab
,
2460 Sized_relobj_file
<32, false>* object
,
2461 unsigned int data_shndx
,
2463 const unsigned char* prelocs
,
2465 Output_section
* output_section
,
2466 bool needs_special_offset_handling
,
2467 size_t local_symbol_count
,
2468 const unsigned char* plocal_symbols
)
2470 gold::gc_process_relocs
<32, false, Target_i386
, elfcpp::SHT_REL
,
2472 Target_i386::Relocatable_size_for_reloc
>(
2481 needs_special_offset_handling
,
2486 // Scan relocations for a section.
2489 Target_i386::scan_relocs(Symbol_table
* symtab
,
2491 Sized_relobj_file
<32, false>* object
,
2492 unsigned int data_shndx
,
2493 unsigned int sh_type
,
2494 const unsigned char* prelocs
,
2496 Output_section
* output_section
,
2497 bool needs_special_offset_handling
,
2498 size_t local_symbol_count
,
2499 const unsigned char* plocal_symbols
)
2501 if (sh_type
== elfcpp::SHT_RELA
)
2503 gold_error(_("%s: unsupported RELA reloc section"),
2504 object
->name().c_str());
2508 gold::scan_relocs
<32, false, Target_i386
, elfcpp::SHT_REL
,
2518 needs_special_offset_handling
,
2523 // Finalize the sections.
2526 Target_i386::do_finalize_sections(
2528 const Input_objects
*,
2529 Symbol_table
* symtab
)
2531 const Reloc_section
* rel_plt
= (this->plt_
== NULL
2533 : this->plt_
->rel_plt());
2534 layout
->add_target_dynamic_tags(true, this->got_plt_
, rel_plt
,
2535 this->rel_dyn_
, true, false);
2537 // Emit any relocs we saved in an attempt to avoid generating COPY
2539 if (this->copy_relocs_
.any_saved_relocs())
2540 this->copy_relocs_
.emit(this->rel_dyn_section(layout
));
2542 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
2543 // the .got.plt section.
2544 Symbol
* sym
= this->global_offset_table_
;
2547 uint32_t data_size
= this->got_plt_
->current_data_size();
2548 symtab
->get_sized_symbol
<32>(sym
)->set_symsize(data_size
);
2551 if (parameters
->doing_static_link()
2552 && (this->plt_
== NULL
|| !this->plt_
->has_irelative_section()))
2554 // If linking statically, make sure that the __rel_iplt symbols
2555 // were defined if necessary, even if we didn't create a PLT.
2556 static const Define_symbol_in_segment syms
[] =
2559 "__rel_iplt_start", // name
2560 elfcpp::PT_LOAD
, // segment_type
2561 elfcpp::PF_W
, // segment_flags_set
2562 elfcpp::PF(0), // segment_flags_clear
2565 elfcpp::STT_NOTYPE
, // type
2566 elfcpp::STB_GLOBAL
, // binding
2567 elfcpp::STV_HIDDEN
, // visibility
2569 Symbol::SEGMENT_START
, // offset_from_base
2573 "__rel_iplt_end", // name
2574 elfcpp::PT_LOAD
, // segment_type
2575 elfcpp::PF_W
, // segment_flags_set
2576 elfcpp::PF(0), // segment_flags_clear
2579 elfcpp::STT_NOTYPE
, // type
2580 elfcpp::STB_GLOBAL
, // binding
2581 elfcpp::STV_HIDDEN
, // visibility
2583 Symbol::SEGMENT_START
, // offset_from_base
2588 symtab
->define_symbols(layout
, 2, syms
,
2589 layout
->script_options()->saw_sections_clause());
2593 // Return whether a direct absolute static relocation needs to be applied.
2594 // In cases where Scan::local() or Scan::global() has created
2595 // a dynamic relocation other than R_386_RELATIVE, the addend
2596 // of the relocation is carried in the data, and we must not
2597 // apply the static relocation.
2600 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
2601 unsigned int r_type
,
2603 Output_section
* output_section
)
2605 // If the output section is not allocated, then we didn't call
2606 // scan_relocs, we didn't create a dynamic reloc, and we must apply
2608 if ((output_section
->flags() & elfcpp::SHF_ALLOC
) == 0)
2611 int ref_flags
= Scan::get_reference_flags(r_type
);
2613 // For local symbols, we will have created a non-RELATIVE dynamic
2614 // relocation only if (a) the output is position independent,
2615 // (b) the relocation is absolute (not pc- or segment-relative), and
2616 // (c) the relocation is not 32 bits wide.
2618 return !(parameters
->options().output_is_position_independent()
2619 && (ref_flags
& Symbol::ABSOLUTE_REF
)
2622 // For global symbols, we use the same helper routines used in the
2623 // scan pass. If we did not create a dynamic relocation, or if we
2624 // created a RELATIVE dynamic relocation, we should apply the static
2626 bool has_dyn
= gsym
->needs_dynamic_reloc(ref_flags
);
2627 bool is_rel
= (ref_flags
& Symbol::ABSOLUTE_REF
)
2628 && gsym
->can_use_relative_reloc(ref_flags
2629 & Symbol::FUNCTION_CALL
);
2630 return !has_dyn
|| is_rel
;
2633 // Perform a relocation.
2636 Target_i386::Relocate::relocate(const Relocate_info
<32, false>* relinfo
,
2637 Target_i386
* target
,
2638 Output_section
* output_section
,
2640 const elfcpp::Rel
<32, false>& rel
,
2641 unsigned int r_type
,
2642 const Sized_symbol
<32>* gsym
,
2643 const Symbol_value
<32>* psymval
,
2644 unsigned char* view
,
2645 elfcpp::Elf_types
<32>::Elf_Addr address
,
2646 section_size_type view_size
)
2648 if (this->skip_call_tls_get_addr_
)
2650 if ((r_type
!= elfcpp::R_386_PLT32
2651 && r_type
!= elfcpp::R_386_PC32
)
2653 || strcmp(gsym
->name(), "___tls_get_addr") != 0)
2654 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2655 _("missing expected TLS relocation"));
2658 this->skip_call_tls_get_addr_
= false;
2666 const Sized_relobj_file
<32, false>* object
= relinfo
->object
;
2668 // Pick the value to use for symbols defined in shared objects.
2669 Symbol_value
<32> symval
;
2671 && gsym
->type() == elfcpp::STT_GNU_IFUNC
2672 && r_type
== elfcpp::R_386_32
2673 && gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
))
2674 && gsym
->can_use_relative_reloc(false)
2675 && !gsym
->is_from_dynobj()
2676 && !gsym
->is_undefined()
2677 && !gsym
->is_preemptible())
2679 // In this case we are generating a R_386_IRELATIVE reloc. We
2680 // want to use the real value of the symbol, not the PLT offset.
2682 else if (gsym
!= NULL
2683 && gsym
->use_plt_offset(Scan::get_reference_flags(r_type
)))
2685 symval
.set_output_value(target
->plt_address_for_global(gsym
));
2688 else if (gsym
== NULL
&& psymval
->is_ifunc_symbol())
2690 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2691 if (object
->local_has_plt_offset(r_sym
))
2693 symval
.set_output_value(target
->plt_address_for_local(object
, r_sym
));
2698 // Get the GOT offset if needed.
2699 // The GOT pointer points to the end of the GOT section.
2700 // We need to subtract the size of the GOT section to get
2701 // the actual offset to use in the relocation.
2702 bool have_got_offset
= false;
2703 unsigned int got_offset
= 0;
2706 case elfcpp::R_386_GOT32
:
2709 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
2710 got_offset
= (gsym
->got_offset(GOT_TYPE_STANDARD
)
2711 - target
->got_size());
2715 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2716 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
2717 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
2718 - target
->got_size());
2720 have_got_offset
= true;
2729 case elfcpp::R_386_NONE
:
2730 case elfcpp::R_386_GNU_VTINHERIT
:
2731 case elfcpp::R_386_GNU_VTENTRY
:
2734 case elfcpp::R_386_32
:
2735 if (should_apply_static_reloc(gsym
, r_type
, true, output_section
))
2736 Relocate_functions
<32, false>::rel32(view
, object
, psymval
);
2739 case elfcpp::R_386_PC32
:
2740 if (should_apply_static_reloc(gsym
, r_type
, true, output_section
))
2741 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
2744 case elfcpp::R_386_16
:
2745 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2746 Relocate_functions
<32, false>::rel16(view
, object
, psymval
);
2749 case elfcpp::R_386_PC16
:
2750 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2751 Relocate_functions
<32, false>::pcrel16(view
, object
, psymval
, address
);
2754 case elfcpp::R_386_8
:
2755 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2756 Relocate_functions
<32, false>::rel8(view
, object
, psymval
);
2759 case elfcpp::R_386_PC8
:
2760 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2761 Relocate_functions
<32, false>::pcrel8(view
, object
, psymval
, address
);
2764 case elfcpp::R_386_PLT32
:
2765 gold_assert(gsym
== NULL
2766 || gsym
->has_plt_offset()
2767 || gsym
->final_value_is_known()
2768 || (gsym
->is_defined()
2769 && !gsym
->is_from_dynobj()
2770 && !gsym
->is_preemptible()));
2771 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
2774 case elfcpp::R_386_GOT32
:
2775 gold_assert(have_got_offset
);
2776 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2779 case elfcpp::R_386_GOTOFF
:
2781 elfcpp::Elf_types
<32>::Elf_Addr value
;
2782 value
= (psymval
->value(object
, 0)
2783 - target
->got_plt_section()->address());
2784 Relocate_functions
<32, false>::rel32(view
, value
);
2788 case elfcpp::R_386_GOTPC
:
2790 elfcpp::Elf_types
<32>::Elf_Addr value
;
2791 value
= target
->got_plt_section()->address();
2792 Relocate_functions
<32, false>::pcrel32(view
, value
, address
);
2796 case elfcpp::R_386_COPY
:
2797 case elfcpp::R_386_GLOB_DAT
:
2798 case elfcpp::R_386_JUMP_SLOT
:
2799 case elfcpp::R_386_RELATIVE
:
2800 case elfcpp::R_386_IRELATIVE
:
2801 // These are outstanding tls relocs, which are unexpected when
2803 case elfcpp::R_386_TLS_TPOFF
:
2804 case elfcpp::R_386_TLS_DTPMOD32
:
2805 case elfcpp::R_386_TLS_DTPOFF32
:
2806 case elfcpp::R_386_TLS_TPOFF32
:
2807 case elfcpp::R_386_TLS_DESC
:
2808 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2809 _("unexpected reloc %u in object file"),
2813 // These are initial tls relocs, which are expected when
2815 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2816 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2817 case elfcpp::R_386_TLS_DESC_CALL
:
2818 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2819 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2820 case elfcpp::R_386_TLS_IE
: // Initial-exec
2821 case elfcpp::R_386_TLS_IE_32
:
2822 case elfcpp::R_386_TLS_GOTIE
:
2823 case elfcpp::R_386_TLS_LE
: // Local-exec
2824 case elfcpp::R_386_TLS_LE_32
:
2825 this->relocate_tls(relinfo
, target
, relnum
, rel
, r_type
, gsym
, psymval
,
2826 view
, address
, view_size
);
2829 case elfcpp::R_386_32PLT
:
2830 case elfcpp::R_386_TLS_GD_32
:
2831 case elfcpp::R_386_TLS_GD_PUSH
:
2832 case elfcpp::R_386_TLS_GD_CALL
:
2833 case elfcpp::R_386_TLS_GD_POP
:
2834 case elfcpp::R_386_TLS_LDM_32
:
2835 case elfcpp::R_386_TLS_LDM_PUSH
:
2836 case elfcpp::R_386_TLS_LDM_CALL
:
2837 case elfcpp::R_386_TLS_LDM_POP
:
2838 case elfcpp::R_386_USED_BY_INTEL_200
:
2840 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2841 _("unsupported reloc %u"),
2849 // Perform a TLS relocation.
2852 Target_i386::Relocate::relocate_tls(const Relocate_info
<32, false>* relinfo
,
2853 Target_i386
* target
,
2855 const elfcpp::Rel
<32, false>& rel
,
2856 unsigned int r_type
,
2857 const Sized_symbol
<32>* gsym
,
2858 const Symbol_value
<32>* psymval
,
2859 unsigned char* view
,
2860 elfcpp::Elf_types
<32>::Elf_Addr
,
2861 section_size_type view_size
)
2863 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
2865 const Sized_relobj_file
<32, false>* object
= relinfo
->object
;
2867 elfcpp::Elf_types
<32>::Elf_Addr value
= psymval
->value(object
, 0);
2869 const bool is_final
= (gsym
== NULL
2870 ? !parameters
->options().shared()
2871 : gsym
->final_value_is_known());
2872 const tls::Tls_optimization optimized_type
2873 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
2876 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2877 if (optimized_type
== tls::TLSOPT_TO_LE
)
2879 if (tls_segment
== NULL
)
2881 gold_assert(parameters
->errors()->error_count() > 0
2882 || issue_undefined_symbol_error(gsym
));
2885 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
2886 rel
, r_type
, value
, view
,
2892 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
2893 ? GOT_TYPE_TLS_NOFFSET
2894 : GOT_TYPE_TLS_PAIR
);
2895 unsigned int got_offset
;
2898 gold_assert(gsym
->has_got_offset(got_type
));
2899 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
2903 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2904 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
2905 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
2906 - target
->got_size());
2908 if (optimized_type
== tls::TLSOPT_TO_IE
)
2910 this->tls_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
2911 got_offset
, view
, view_size
);
2914 else if (optimized_type
== tls::TLSOPT_NONE
)
2916 // Relocate the field with the offset of the pair of GOT
2918 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2922 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2923 _("unsupported reloc %u"),
2927 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2928 case elfcpp::R_386_TLS_DESC_CALL
:
2929 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
2930 if (optimized_type
== tls::TLSOPT_TO_LE
)
2932 if (tls_segment
== NULL
)
2934 gold_assert(parameters
->errors()->error_count() > 0
2935 || issue_undefined_symbol_error(gsym
));
2938 this->tls_desc_gd_to_le(relinfo
, relnum
, tls_segment
,
2939 rel
, r_type
, value
, view
,
2945 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
2946 ? GOT_TYPE_TLS_NOFFSET
2947 : GOT_TYPE_TLS_DESC
);
2948 unsigned int got_offset
= 0;
2949 if (r_type
== elfcpp::R_386_TLS_GOTDESC
2950 && optimized_type
== tls::TLSOPT_NONE
)
2952 // We created GOT entries in the .got.tlsdesc portion of
2953 // the .got.plt section, but the offset stored in the
2954 // symbol is the offset within .got.tlsdesc.
2955 got_offset
= (target
->got_size()
2956 + target
->got_plt_section()->data_size());
2960 gold_assert(gsym
->has_got_offset(got_type
));
2961 got_offset
+= gsym
->got_offset(got_type
) - target
->got_size();
2965 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2966 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
2967 got_offset
+= (object
->local_got_offset(r_sym
, got_type
)
2968 - target
->got_size());
2970 if (optimized_type
== tls::TLSOPT_TO_IE
)
2972 if (tls_segment
== NULL
)
2974 gold_assert(parameters
->errors()->error_count() > 0
2975 || issue_undefined_symbol_error(gsym
));
2978 this->tls_desc_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
2979 got_offset
, view
, view_size
);
2982 else if (optimized_type
== tls::TLSOPT_NONE
)
2984 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
2986 // Relocate the field with the offset of the pair of GOT
2988 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2993 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2994 _("unsupported reloc %u"),
2998 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2999 if (this->local_dynamic_type_
== LOCAL_DYNAMIC_SUN
)
3001 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3002 _("both SUN and GNU model "
3003 "TLS relocations"));
3006 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
3007 if (optimized_type
== tls::TLSOPT_TO_LE
)
3009 if (tls_segment
== NULL
)
3011 gold_assert(parameters
->errors()->error_count() > 0
3012 || issue_undefined_symbol_error(gsym
));
3015 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rel
, r_type
,
3016 value
, view
, view_size
);
3019 else if (optimized_type
== tls::TLSOPT_NONE
)
3021 // Relocate the field with the offset of the GOT entry for
3022 // the module index.
3023 unsigned int got_offset
;
3024 got_offset
= (target
->got_mod_index_entry(NULL
, NULL
, NULL
)
3025 - target
->got_size());
3026 Relocate_functions
<32, false>::rel32(view
, got_offset
);
3029 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3030 _("unsupported reloc %u"),
3034 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
3035 if (optimized_type
== tls::TLSOPT_TO_LE
)
3037 // This reloc can appear in debugging sections, in which
3038 // case we must not convert to local-exec. We decide what
3039 // to do based on whether the section is marked as
3040 // containing executable code. That is what the GNU linker
3042 elfcpp::Shdr
<32, false> shdr(relinfo
->data_shdr
);
3043 if ((shdr
.get_sh_flags() & elfcpp::SHF_EXECINSTR
) != 0)
3045 if (tls_segment
== NULL
)
3047 gold_assert(parameters
->errors()->error_count() > 0
3048 || issue_undefined_symbol_error(gsym
));
3051 value
-= tls_segment
->memsz();
3054 Relocate_functions
<32, false>::rel32(view
, value
);
3057 case elfcpp::R_386_TLS_IE
: // Initial-exec
3058 case elfcpp::R_386_TLS_GOTIE
:
3059 case elfcpp::R_386_TLS_IE_32
:
3060 if (optimized_type
== tls::TLSOPT_TO_LE
)
3062 if (tls_segment
== NULL
)
3064 gold_assert(parameters
->errors()->error_count() > 0
3065 || issue_undefined_symbol_error(gsym
));
3068 Target_i386::Relocate::tls_ie_to_le(relinfo
, relnum
, tls_segment
,
3069 rel
, r_type
, value
, view
,
3073 else if (optimized_type
== tls::TLSOPT_NONE
)
3075 // Relocate the field with the offset of the GOT entry for
3076 // the tp-relative offset of the symbol.
3077 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
3078 ? GOT_TYPE_TLS_OFFSET
3079 : GOT_TYPE_TLS_NOFFSET
);
3080 unsigned int got_offset
;
3083 gold_assert(gsym
->has_got_offset(got_type
));
3084 got_offset
= gsym
->got_offset(got_type
);
3088 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
3089 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
3090 got_offset
= object
->local_got_offset(r_sym
, got_type
);
3092 // For the R_386_TLS_IE relocation, we need to apply the
3093 // absolute address of the GOT entry.
3094 if (r_type
== elfcpp::R_386_TLS_IE
)
3095 got_offset
+= target
->got_plt_section()->address();
3096 // All GOT offsets are relative to the end of the GOT.
3097 got_offset
-= target
->got_size();
3098 Relocate_functions
<32, false>::rel32(view
, got_offset
);
3101 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3102 _("unsupported reloc %u"),
3106 case elfcpp::R_386_TLS_LE
: // Local-exec
3107 // If we're creating a shared library, a dynamic relocation will
3108 // have been created for this location, so do not apply it now.
3109 if (!parameters
->options().shared())
3111 if (tls_segment
== NULL
)
3113 gold_assert(parameters
->errors()->error_count() > 0
3114 || issue_undefined_symbol_error(gsym
));
3117 value
-= tls_segment
->memsz();
3118 Relocate_functions
<32, false>::rel32(view
, value
);
3122 case elfcpp::R_386_TLS_LE_32
:
3123 // If we're creating a shared library, a dynamic relocation will
3124 // have been created for this location, so do not apply it now.
3125 if (!parameters
->options().shared())
3127 if (tls_segment
== NULL
)
3129 gold_assert(parameters
->errors()->error_count() > 0
3130 || issue_undefined_symbol_error(gsym
));
3133 value
= tls_segment
->memsz() - value
;
3134 Relocate_functions
<32, false>::rel32(view
, value
);
3140 // Do a relocation in which we convert a TLS General-Dynamic to a
3144 Target_i386::Relocate::tls_gd_to_le(const Relocate_info
<32, false>* relinfo
,
3146 Output_segment
* tls_segment
,
3147 const elfcpp::Rel
<32, false>& rel
,
3149 elfcpp::Elf_types
<32>::Elf_Addr value
,
3150 unsigned char* view
,
3151 section_size_type view_size
)
3153 // leal foo(,%reg,1),%eax; call ___tls_get_addr
3154 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
3155 // leal foo(%reg),%eax; call ___tls_get_addr
3156 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
3158 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3159 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
3161 unsigned char op1
= view
[-1];
3162 unsigned char op2
= view
[-2];
3164 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3165 op2
== 0x8d || op2
== 0x04);
3166 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
3172 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
3173 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
3174 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3175 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
3176 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3180 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3181 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
3182 if (rel
.get_r_offset() + 9 < view_size
3185 // There is a trailing nop. Use the size byte subl.
3186 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3191 // Use the five byte subl.
3192 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
3196 value
= tls_segment
->memsz() - value
;
3197 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
3199 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3201 this->skip_call_tls_get_addr_
= true;
3204 // Do a relocation in which we convert a TLS General-Dynamic to an
3208 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info
<32, false>* relinfo
,
3211 const elfcpp::Rel
<32, false>& rel
,
3213 elfcpp::Elf_types
<32>::Elf_Addr value
,
3214 unsigned char* view
,
3215 section_size_type view_size
)
3217 // leal foo(,%ebx,1),%eax; call ___tls_get_addr
3218 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
3220 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3221 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
3223 unsigned char op1
= view
[-1];
3224 unsigned char op2
= view
[-2];
3226 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3227 op2
== 0x8d || op2
== 0x04);
3228 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
3232 // FIXME: For now, support only the first (SIB) form.
3233 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), op2
== 0x04);
3237 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
3238 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
3239 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3240 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
3241 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
3245 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3246 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
3247 if (rel
.get_r_offset() + 9 < view_size
3250 // FIXME: This is not the right instruction sequence.
3251 // There is a trailing nop. Use the size byte subl.
3252 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3257 // FIXME: This is not the right instruction sequence.
3258 // Use the five byte subl.
3259 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
3263 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
3265 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3267 this->skip_call_tls_get_addr_
= true;
3270 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3271 // General-Dynamic to a Local-Exec.
3274 Target_i386::Relocate::tls_desc_gd_to_le(
3275 const Relocate_info
<32, false>* relinfo
,
3277 Output_segment
* tls_segment
,
3278 const elfcpp::Rel
<32, false>& rel
,
3279 unsigned int r_type
,
3280 elfcpp::Elf_types
<32>::Elf_Addr value
,
3281 unsigned char* view
,
3282 section_size_type view_size
)
3284 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
3286 // leal foo@TLSDESC(%ebx), %eax
3287 // ==> leal foo@NTPOFF, %eax
3288 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3289 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3290 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3291 view
[-2] == 0x8d && view
[-1] == 0x83);
3293 value
-= tls_segment
->memsz();
3294 Relocate_functions
<32, false>::rel32(view
, value
);
3298 // call *foo@TLSCALL(%eax)
3300 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
3301 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
3302 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3303 view
[0] == 0xff && view
[1] == 0x10);
3309 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3310 // General-Dynamic to an Initial-Exec.
3313 Target_i386::Relocate::tls_desc_gd_to_ie(
3314 const Relocate_info
<32, false>* relinfo
,
3317 const elfcpp::Rel
<32, false>& rel
,
3318 unsigned int r_type
,
3319 elfcpp::Elf_types
<32>::Elf_Addr value
,
3320 unsigned char* view
,
3321 section_size_type view_size
)
3323 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
3325 // leal foo@TLSDESC(%ebx), %eax
3326 // ==> movl foo@GOTNTPOFF(%ebx), %eax
3327 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3328 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3329 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3330 view
[-2] == 0x8d && view
[-1] == 0x83);
3332 Relocate_functions
<32, false>::rel32(view
, value
);
3336 // call *foo@TLSCALL(%eax)
3338 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
3339 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
3340 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3341 view
[0] == 0xff && view
[1] == 0x10);
3347 // Do a relocation in which we convert a TLS Local-Dynamic to a
3351 Target_i386::Relocate::tls_ld_to_le(const Relocate_info
<32, false>* relinfo
,
3354 const elfcpp::Rel
<32, false>& rel
,
3356 elfcpp::Elf_types
<32>::Elf_Addr
,
3357 unsigned char* view
,
3358 section_size_type view_size
)
3360 // leal foo(%reg), %eax; call ___tls_get_addr
3361 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
3363 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3364 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
3366 // FIXME: Does this test really always pass?
3367 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3368 view
[-2] == 0x8d && view
[-1] == 0x83);
3370 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
3372 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
3374 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3376 this->skip_call_tls_get_addr_
= true;
3379 // Do a relocation in which we convert a TLS Initial-Exec to a
3383 Target_i386::Relocate::tls_ie_to_le(const Relocate_info
<32, false>* relinfo
,
3385 Output_segment
* tls_segment
,
3386 const elfcpp::Rel
<32, false>& rel
,
3387 unsigned int r_type
,
3388 elfcpp::Elf_types
<32>::Elf_Addr value
,
3389 unsigned char* view
,
3390 section_size_type view_size
)
3392 // We have to actually change the instructions, which means that we
3393 // need to examine the opcodes to figure out which instruction we
3395 if (r_type
== elfcpp::R_386_TLS_IE
)
3397 // movl %gs:XX,%eax ==> movl $YY,%eax
3398 // movl %gs:XX,%reg ==> movl $YY,%reg
3399 // addl %gs:XX,%reg ==> addl $YY,%reg
3400 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -1);
3401 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3403 unsigned char op1
= view
[-1];
3406 // movl XX,%eax ==> movl $YY,%eax
3411 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3413 unsigned char op2
= view
[-2];
3416 // movl XX,%reg ==> movl $YY,%reg
3417 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3418 (op1
& 0xc7) == 0x05);
3420 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3422 else if (op2
== 0x03)
3424 // addl XX,%reg ==> addl $YY,%reg
3425 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3426 (op1
& 0xc7) == 0x05);
3428 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3431 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
3436 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
3437 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
3438 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
3439 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3440 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3442 unsigned char op1
= view
[-1];
3443 unsigned char op2
= view
[-2];
3444 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3445 (op1
& 0xc0) == 0x80 && (op1
& 7) != 4);
3448 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
3450 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3452 else if (op2
== 0x2b)
3454 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
3456 view
[-1] = 0xe8 | ((op1
>> 3) & 7);
3458 else if (op2
== 0x03)
3460 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
3462 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3465 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
3468 value
= tls_segment
->memsz() - value
;
3469 if (r_type
== elfcpp::R_386_TLS_IE
|| r_type
== elfcpp::R_386_TLS_GOTIE
)
3472 Relocate_functions
<32, false>::rel32(view
, value
);
3475 // Relocate section data.
3478 Target_i386::relocate_section(const Relocate_info
<32, false>* relinfo
,
3479 unsigned int sh_type
,
3480 const unsigned char* prelocs
,
3482 Output_section
* output_section
,
3483 bool needs_special_offset_handling
,
3484 unsigned char* view
,
3485 elfcpp::Elf_types
<32>::Elf_Addr address
,
3486 section_size_type view_size
,
3487 const Reloc_symbol_changes
* reloc_symbol_changes
)
3489 gold_assert(sh_type
== elfcpp::SHT_REL
);
3491 gold::relocate_section
<32, false, Target_i386
, elfcpp::SHT_REL
,
3492 Target_i386::Relocate
, gold::Default_comdat_behavior
>(
3498 needs_special_offset_handling
,
3502 reloc_symbol_changes
);
3505 // Return the size of a relocation while scanning during a relocatable
3509 Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
3510 unsigned int r_type
,
3515 case elfcpp::R_386_NONE
:
3516 case elfcpp::R_386_GNU_VTINHERIT
:
3517 case elfcpp::R_386_GNU_VTENTRY
:
3518 case elfcpp::R_386_TLS_GD
: // Global-dynamic
3519 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
3520 case elfcpp::R_386_TLS_DESC_CALL
:
3521 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
3522 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
3523 case elfcpp::R_386_TLS_IE
: // Initial-exec
3524 case elfcpp::R_386_TLS_IE_32
:
3525 case elfcpp::R_386_TLS_GOTIE
:
3526 case elfcpp::R_386_TLS_LE
: // Local-exec
3527 case elfcpp::R_386_TLS_LE_32
:
3530 case elfcpp::R_386_32
:
3531 case elfcpp::R_386_PC32
:
3532 case elfcpp::R_386_GOT32
:
3533 case elfcpp::R_386_PLT32
:
3534 case elfcpp::R_386_GOTOFF
:
3535 case elfcpp::R_386_GOTPC
:
3538 case elfcpp::R_386_16
:
3539 case elfcpp::R_386_PC16
:
3542 case elfcpp::R_386_8
:
3543 case elfcpp::R_386_PC8
:
3546 // These are relocations which should only be seen by the
3547 // dynamic linker, and should never be seen here.
3548 case elfcpp::R_386_COPY
:
3549 case elfcpp::R_386_GLOB_DAT
:
3550 case elfcpp::R_386_JUMP_SLOT
:
3551 case elfcpp::R_386_RELATIVE
:
3552 case elfcpp::R_386_IRELATIVE
:
3553 case elfcpp::R_386_TLS_TPOFF
:
3554 case elfcpp::R_386_TLS_DTPMOD32
:
3555 case elfcpp::R_386_TLS_DTPOFF32
:
3556 case elfcpp::R_386_TLS_TPOFF32
:
3557 case elfcpp::R_386_TLS_DESC
:
3558 object
->error(_("unexpected reloc %u in object file"), r_type
);
3561 case elfcpp::R_386_32PLT
:
3562 case elfcpp::R_386_TLS_GD_32
:
3563 case elfcpp::R_386_TLS_GD_PUSH
:
3564 case elfcpp::R_386_TLS_GD_CALL
:
3565 case elfcpp::R_386_TLS_GD_POP
:
3566 case elfcpp::R_386_TLS_LDM_32
:
3567 case elfcpp::R_386_TLS_LDM_PUSH
:
3568 case elfcpp::R_386_TLS_LDM_CALL
:
3569 case elfcpp::R_386_TLS_LDM_POP
:
3570 case elfcpp::R_386_USED_BY_INTEL_200
:
3572 object
->error(_("unsupported reloc %u in object file"), r_type
);
3577 // Scan the relocs during a relocatable link.
3580 Target_i386::scan_relocatable_relocs(Symbol_table
* symtab
,
3582 Sized_relobj_file
<32, false>* object
,
3583 unsigned int data_shndx
,
3584 unsigned int sh_type
,
3585 const unsigned char* prelocs
,
3587 Output_section
* output_section
,
3588 bool needs_special_offset_handling
,
3589 size_t local_symbol_count
,
3590 const unsigned char* plocal_symbols
,
3591 Relocatable_relocs
* rr
)
3593 gold_assert(sh_type
== elfcpp::SHT_REL
);
3595 typedef gold::Default_scan_relocatable_relocs
<elfcpp::SHT_REL
,
3596 Relocatable_size_for_reloc
> Scan_relocatable_relocs
;
3598 gold::scan_relocatable_relocs
<32, false, elfcpp::SHT_REL
,
3599 Scan_relocatable_relocs
>(
3607 needs_special_offset_handling
,
3613 // Emit relocations for a section.
3616 Target_i386::relocate_relocs(
3617 const Relocate_info
<32, false>* relinfo
,
3618 unsigned int sh_type
,
3619 const unsigned char* prelocs
,
3621 Output_section
* output_section
,
3622 elfcpp::Elf_types
<32>::Elf_Off offset_in_output_section
,
3623 const Relocatable_relocs
* rr
,
3624 unsigned char* view
,
3625 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
3626 section_size_type view_size
,
3627 unsigned char* reloc_view
,
3628 section_size_type reloc_view_size
)
3630 gold_assert(sh_type
== elfcpp::SHT_REL
);
3632 gold::relocate_relocs
<32, false, elfcpp::SHT_REL
>(
3637 offset_in_output_section
,
3646 // Return the value to use for a dynamic which requires special
3647 // treatment. This is how we support equality comparisons of function
3648 // pointers across shared library boundaries, as described in the
3649 // processor specific ABI supplement.
3652 Target_i386::do_dynsym_value(const Symbol
* gsym
) const
3654 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
3655 return this->plt_address_for_global(gsym
);
3658 // Return a string used to fill a code section with nops to take up
3659 // the specified length.
3662 Target_i386::do_code_fill(section_size_type length
) const
3666 // Build a jmp instruction to skip over the bytes.
3667 unsigned char jmp
[5];
3669 elfcpp::Swap_unaligned
<32, false>::writeval(jmp
+ 1, length
- 5);
3670 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
3671 + std::string(length
- 5, static_cast<char>(0x90)));
3674 // Nop sequences of various lengths.
3675 const char nop1
[1] = { '\x90' }; // nop
3676 const char nop2
[2] = { '\x66', '\x90' }; // xchg %ax %ax
3677 const char nop3
[3] = { '\x8d', '\x76', '\x00' }; // leal 0(%esi),%esi
3678 const char nop4
[4] = { '\x8d', '\x74', '\x26', // leal 0(%esi,1),%esi
3680 const char nop5
[5] = { '\x90', '\x8d', '\x74', // nop
3681 '\x26', '\x00' }; // leal 0(%esi,1),%esi
3682 const char nop6
[6] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3683 '\x00', '\x00', '\x00' };
3684 const char nop7
[7] = { '\x8d', '\xb4', '\x26', // leal 0L(%esi,1),%esi
3685 '\x00', '\x00', '\x00',
3687 const char nop8
[8] = { '\x90', '\x8d', '\xb4', // nop
3688 '\x26', '\x00', '\x00', // leal 0L(%esi,1),%esi
3690 const char nop9
[9] = { '\x89', '\xf6', '\x8d', // movl %esi,%esi
3691 '\xbc', '\x27', '\x00', // leal 0L(%edi,1),%edi
3692 '\x00', '\x00', '\x00' };
3693 const char nop10
[10] = { '\x8d', '\x76', '\x00', // leal 0(%esi),%esi
3694 '\x8d', '\xbc', '\x27', // leal 0L(%edi,1),%edi
3695 '\x00', '\x00', '\x00',
3697 const char nop11
[11] = { '\x8d', '\x74', '\x26', // leal 0(%esi,1),%esi
3698 '\x00', '\x8d', '\xbc', // leal 0L(%edi,1),%edi
3699 '\x27', '\x00', '\x00',
3701 const char nop12
[12] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3702 '\x00', '\x00', '\x00', // leal 0L(%edi),%edi
3703 '\x8d', '\xbf', '\x00',
3704 '\x00', '\x00', '\x00' };
3705 const char nop13
[13] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3706 '\x00', '\x00', '\x00', // leal 0L(%edi,1),%edi
3707 '\x8d', '\xbc', '\x27',
3708 '\x00', '\x00', '\x00',
3710 const char nop14
[14] = { '\x8d', '\xb4', '\x26', // leal 0L(%esi,1),%esi
3711 '\x00', '\x00', '\x00', // leal 0L(%edi,1),%edi
3712 '\x00', '\x8d', '\xbc',
3713 '\x27', '\x00', '\x00',
3715 const char nop15
[15] = { '\xeb', '\x0d', '\x90', // jmp .+15
3716 '\x90', '\x90', '\x90', // nop,nop,nop,...
3717 '\x90', '\x90', '\x90',
3718 '\x90', '\x90', '\x90',
3719 '\x90', '\x90', '\x90' };
3721 const char* nops
[16] = {
3723 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
3724 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
3727 return std::string(nops
[length
], length
);
3730 // Return the value to use for the base of a DW_EH_PE_datarel offset
3731 // in an FDE. Solaris and SVR4 use DW_EH_PE_datarel because their
3732 // assembler can not write out the difference between two labels in
3733 // different sections, so instead of using a pc-relative value they
3734 // use an offset from the GOT.
3737 Target_i386::do_ehframe_datarel_base() const
3739 gold_assert(this->global_offset_table_
!= NULL
);
3740 Symbol
* sym
= this->global_offset_table_
;
3741 Sized_symbol
<32>* ssym
= static_cast<Sized_symbol
<32>*>(sym
);
3742 return ssym
->value();
3745 // Return whether SYM should be treated as a call to a non-split
3746 // function. We don't want that to be true of a call to a
3747 // get_pc_thunk function.
3750 Target_i386::do_is_call_to_non_split(const Symbol
* sym
, unsigned int) const
3752 return (sym
->type() == elfcpp::STT_FUNC
3753 && !is_prefix_of("__i686.get_pc_thunk.", sym
->name()));
3756 // FNOFFSET in section SHNDX in OBJECT is the start of a function
3757 // compiled with -fsplit-stack. The function calls non-split-stack
3758 // code. We have to change the function so that it always ensures
3759 // that it has enough stack space to run some random function.
3762 Target_i386::do_calls_non_split(Relobj
* object
, unsigned int shndx
,
3763 section_offset_type fnoffset
,
3764 section_size_type fnsize
,
3765 unsigned char* view
,
3766 section_size_type view_size
,
3768 std::string
* to
) const
3770 // The function starts with a comparison of the stack pointer and a
3771 // field in the TCB. This is followed by a jump.
3774 if (this->match_view(view
, view_size
, fnoffset
, "\x65\x3b\x25", 3)
3777 // We will call __morestack if the carry flag is set after this
3778 // comparison. We turn the comparison into an stc instruction
3780 view
[fnoffset
] = '\xf9';
3781 this->set_view_to_nop(view
, view_size
, fnoffset
+ 1, 6);
3783 // lea NN(%esp),%ecx
3784 // lea NN(%esp),%edx
3785 else if ((this->match_view(view
, view_size
, fnoffset
, "\x8d\x8c\x24", 3)
3786 || this->match_view(view
, view_size
, fnoffset
, "\x8d\x94\x24", 3))
3789 // This is loading an offset from the stack pointer for a
3790 // comparison. The offset is negative, so we decrease the
3791 // offset by the amount of space we need for the stack. This
3792 // means we will avoid calling __morestack if there happens to
3793 // be plenty of space on the stack already.
3794 unsigned char* pval
= view
+ fnoffset
+ 3;
3795 uint32_t val
= elfcpp::Swap_unaligned
<32, false>::readval(pval
);
3796 val
-= parameters
->options().split_stack_adjust_size();
3797 elfcpp::Swap_unaligned
<32, false>::writeval(pval
, val
);
3801 if (!object
->has_no_split_stack())
3802 object
->error(_("failed to match split-stack sequence at "
3803 "section %u offset %0zx"),
3804 shndx
, static_cast<size_t>(fnoffset
));
3808 // We have to change the function so that it calls
3809 // __morestack_non_split instead of __morestack. The former will
3810 // allocate additional stack space.
3811 *from
= "__morestack";
3812 *to
= "__morestack_non_split";
3815 // The selector for i386 object files. Note this is never instantiated
3816 // directly. It's only used in Target_selector_i386_nacl, below.
3818 class Target_selector_i386
: public Target_selector_freebsd
3821 Target_selector_i386()
3822 : Target_selector_freebsd(elfcpp::EM_386
, 32, false,
3823 "elf32-i386", "elf32-i386-freebsd",
3828 do_instantiate_target()
3829 { return new Target_i386(); }
3832 // NaCl variant. It uses different PLT contents.
3834 class Output_data_plt_i386_nacl
: public Output_data_plt_i386
3837 Output_data_plt_i386_nacl(Layout
* layout
,
3838 Output_data_space
* got_plt
,
3839 Output_data_space
* got_irelative
)
3840 : Output_data_plt_i386(layout
, plt_entry_size
, got_plt
, got_irelative
)
3844 virtual unsigned int
3845 do_get_plt_entry_size() const
3846 { return plt_entry_size
; }
3849 do_add_eh_frame(Layout
* layout
)
3851 layout
->add_eh_frame_for_plt(this, plt_eh_frame_cie
, plt_eh_frame_cie_size
,
3852 plt_eh_frame_fde
, plt_eh_frame_fde_size
);
3855 // The size of an entry in the PLT.
3856 static const int plt_entry_size
= 64;
3858 // The .eh_frame unwind information for the PLT.
3859 static const int plt_eh_frame_fde_size
= 32;
3860 static const unsigned char plt_eh_frame_fde
[plt_eh_frame_fde_size
];
3863 class Output_data_plt_i386_nacl_exec
: public Output_data_plt_i386_nacl
3866 Output_data_plt_i386_nacl_exec(Layout
* layout
,
3867 Output_data_space
* got_plt
,
3868 Output_data_space
* got_irelative
)
3869 : Output_data_plt_i386_nacl(layout
, got_plt
, got_irelative
)
3874 do_fill_first_plt_entry(unsigned char* pov
,
3875 elfcpp::Elf_types
<32>::Elf_Addr got_address
);
3877 virtual unsigned int
3878 do_fill_plt_entry(unsigned char* pov
,
3879 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
3880 unsigned int got_offset
,
3881 unsigned int plt_offset
,
3882 unsigned int plt_rel_offset
);
3885 // The first entry in the PLT for an executable.
3886 static const unsigned char first_plt_entry
[plt_entry_size
];
3888 // Other entries in the PLT for an executable.
3889 static const unsigned char plt_entry
[plt_entry_size
];
3892 class Output_data_plt_i386_nacl_dyn
: public Output_data_plt_i386_nacl
3895 Output_data_plt_i386_nacl_dyn(Layout
* layout
,
3896 Output_data_space
* got_plt
,
3897 Output_data_space
* got_irelative
)
3898 : Output_data_plt_i386_nacl(layout
, got_plt
, got_irelative
)
3903 do_fill_first_plt_entry(unsigned char* pov
, elfcpp::Elf_types
<32>::Elf_Addr
);
3905 virtual unsigned int
3906 do_fill_plt_entry(unsigned char* pov
,
3907 elfcpp::Elf_types
<32>::Elf_Addr
,
3908 unsigned int got_offset
,
3909 unsigned int plt_offset
,
3910 unsigned int plt_rel_offset
);
3913 // The first entry in the PLT for a shared object.
3914 static const unsigned char first_plt_entry
[plt_entry_size
];
3916 // Other entries in the PLT for a shared object.
3917 static const unsigned char plt_entry
[plt_entry_size
];
3920 class Target_i386_nacl
: public Target_i386
3924 : Target_i386(&i386_nacl_info
)
3928 virtual Output_data_plt_i386
*
3929 do_make_data_plt(Layout
* layout
,
3930 Output_data_space
* got_plt
,
3931 Output_data_space
* got_irelative
,
3935 return new Output_data_plt_i386_nacl_dyn(layout
, got_plt
, got_irelative
);
3937 return new Output_data_plt_i386_nacl_exec(layout
, got_plt
, got_irelative
);
3941 do_code_fill(section_size_type length
) const;
3944 static const Target::Target_info i386_nacl_info
;
3947 const Target::Target_info
Target_i386_nacl::i386_nacl_info
=
3950 false, // is_big_endian
3951 elfcpp::EM_386
, // machine_code
3952 false, // has_make_symbol
3953 false, // has_resolve
3954 true, // has_code_fill
3955 true, // is_default_stack_executable
3956 true, // can_icf_inline_merge_sections
3958 "/lib/ld-nacl-x86-32.so.1", // dynamic_linker
3959 0x20000, // default_text_segment_address
3960 0x10000, // abi_pagesize (overridable by -z max-page-size)
3961 0x10000, // common_pagesize (overridable by -z common-page-size)
3962 true, // isolate_execinstr
3963 0x10000000, // rosegment_gap
3964 elfcpp::SHN_UNDEF
, // small_common_shndx
3965 elfcpp::SHN_UNDEF
, // large_common_shndx
3966 0, // small_common_section_flags
3967 0, // large_common_section_flags
3968 NULL
, // attributes_section
3969 NULL
, // attributes_vendor
3970 "_start" // entry_symbol_name
3973 #define NACLMASK 0xe0 // 32-byte alignment mask
3976 Output_data_plt_i386_nacl_exec::first_plt_entry
[plt_entry_size
] =
3978 0xff, 0x35, // pushl contents of memory address
3979 0, 0, 0, 0, // replaced with address of .got + 4
3980 0x8b, 0x0d, // movl contents of address, %ecx
3981 0, 0, 0, 0, // replaced with address of .got + 8
3982 0x83, 0xe1, NACLMASK
, // andl $NACLMASK, %ecx
3983 0xff, 0xe1, // jmp *%ecx
3984 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3985 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3986 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3987 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3988 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3989 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3990 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
3991 0x90, 0x90, 0x90, 0x90, 0x90
3995 Output_data_plt_i386_nacl_exec::do_fill_first_plt_entry(
3997 elfcpp::Elf_types
<32>::Elf_Addr got_address
)
3999 memcpy(pov
, first_plt_entry
, plt_entry_size
);
4000 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 4);
4001 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 8);
4004 // The first entry in the PLT for a shared object.
4007 Output_data_plt_i386_nacl_dyn::first_plt_entry
[plt_entry_size
] =
4009 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
4010 0x8b, 0x4b, 0x08, // mov 0x8(%ebx), %ecx
4011 0x83, 0xe1, NACLMASK
, // andl $NACLMASK, %ecx
4012 0xff, 0xe1, // jmp *%ecx
4013 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4014 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4015 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4016 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4017 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4018 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4019 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4020 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4021 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4022 0x90, 0x90, 0x90, 0x90, 0x90 // nops
4026 Output_data_plt_i386_nacl_dyn::do_fill_first_plt_entry(
4028 elfcpp::Elf_types
<32>::Elf_Addr
)
4030 memcpy(pov
, first_plt_entry
, plt_entry_size
);
4033 // Subsequent entries in the PLT for an executable.
4036 Output_data_plt_i386_nacl_exec::plt_entry
[plt_entry_size
] =
4038 0x8b, 0x0d, // movl contents of address, %ecx */
4039 0, 0, 0, 0, // replaced with address of symbol in .got
4040 0x83, 0xe1, NACLMASK
, // andl $NACLMASK, %ecx
4041 0xff, 0xe1, // jmp *%ecx
4043 // Pad to the next 32-byte boundary with nop instructions.
4045 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4046 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4048 // Lazy GOT entries point here (32-byte aligned).
4049 0x68, // pushl immediate
4050 0, 0, 0, 0, // replaced with offset into relocation table
4051 0xe9, // jmp relative
4052 0, 0, 0, 0, // replaced with offset to start of .plt
4054 // Pad to the next 32-byte boundary with nop instructions.
4055 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4056 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4061 Output_data_plt_i386_nacl_exec::do_fill_plt_entry(
4063 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
4064 unsigned int got_offset
,
4065 unsigned int plt_offset
,
4066 unsigned int plt_rel_offset
)
4068 memcpy(pov
, plt_entry
, plt_entry_size
);
4069 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
4070 got_address
+ got_offset
);
4071 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 33, plt_rel_offset
);
4072 elfcpp::Swap
<32, false>::writeval(pov
+ 38, - (plt_offset
+ 38 + 4));
4076 // Subsequent entries in the PLT for a shared object.
4079 Output_data_plt_i386_nacl_dyn::plt_entry
[plt_entry_size
] =
4081 0x8b, 0x8b, // movl offset(%ebx), %ecx
4082 0, 0, 0, 0, // replaced with offset of symbol in .got
4083 0x83, 0xe1, 0xe0, // andl $NACLMASK, %ecx
4084 0xff, 0xe1, // jmp *%ecx
4086 // Pad to the next 32-byte boundary with nop instructions.
4088 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4089 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4091 // Lazy GOT entries point here (32-byte aligned).
4092 0x68, // pushl immediate
4093 0, 0, 0, 0, // replaced with offset into relocation table.
4094 0xe9, // jmp relative
4095 0, 0, 0, 0, // replaced with offset to start of .plt.
4097 // Pad to the next 32-byte boundary with nop instructions.
4098 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4099 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4104 Output_data_plt_i386_nacl_dyn::do_fill_plt_entry(
4106 elfcpp::Elf_types
<32>::Elf_Addr
,
4107 unsigned int got_offset
,
4108 unsigned int plt_offset
,
4109 unsigned int plt_rel_offset
)
4111 memcpy(pov
, plt_entry
, plt_entry_size
);
4112 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
4113 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 33, plt_rel_offset
);
4114 elfcpp::Swap
<32, false>::writeval(pov
+ 38, - (plt_offset
+ 38 + 4));
4119 Output_data_plt_i386_nacl::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
4121 0, 0, 0, 0, // Replaced with offset to .plt.
4122 0, 0, 0, 0, // Replaced with size of .plt.
4123 0, // Augmentation size.
4124 elfcpp::DW_CFA_def_cfa_offset
, 8, // DW_CFA_def_cfa_offset: 8.
4125 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
4126 elfcpp::DW_CFA_def_cfa_offset
, 12, // DW_CFA_def_cfa_offset: 12.
4127 elfcpp::DW_CFA_advance_loc
+ 58, // Advance 58 to __PLT__ + 64.
4128 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
4129 13, // Block length.
4130 elfcpp::DW_OP_breg4
, 4, // Push %esp + 4.
4131 elfcpp::DW_OP_breg8
, 0, // Push %eip.
4132 elfcpp::DW_OP_const1u
, 63, // Push 0x3f.
4133 elfcpp::DW_OP_and
, // & (%eip & 0x3f).
4134 elfcpp::DW_OP_const1u
, 37, // Push 0x25.
4135 elfcpp::DW_OP_ge
, // >= ((%eip & 0x3f) >= 0x25)
4136 elfcpp::DW_OP_lit2
, // Push 2.
4137 elfcpp::DW_OP_shl
, // << (((%eip & 0x3f) >= 0x25) << 2)
4138 elfcpp::DW_OP_plus
, // + ((((%eip&0x3f)>=0x25)<<2)+%esp+4
4139 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
4143 // Return a string used to fill a code section with nops.
4144 // For NaCl, long NOPs are only valid if they do not cross
4145 // bundle alignment boundaries, so keep it simple with one-byte NOPs.
4147 Target_i386_nacl::do_code_fill(section_size_type length
) const
4149 return std::string(length
, static_cast<char>(0x90));
4152 // The selector for i386-nacl object files.
4154 class Target_selector_i386_nacl
4155 : public Target_selector_nacl
<Target_selector_i386
, Target_i386_nacl
>
4158 Target_selector_i386_nacl()
4159 : Target_selector_nacl
<Target_selector_i386
,
4160 Target_i386_nacl
>("x86-32",
4166 Target_selector_i386_nacl target_selector_i386
;
4168 } // End anonymous namespace.