1 // i386.cc -- i386 target support for gold.
3 // Copyright (C) 2006-2016 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
29 #include "parameters.h"
36 #include "copy-relocs.h"
38 #include "target-reloc.h"
39 #include "target-select.h"
50 // A class to handle the .got.plt section.
52 class Output_data_got_plt_i386
: public Output_section_data_build
55 Output_data_got_plt_i386(Layout
* layout
)
56 : Output_section_data_build(4),
61 // Write out the PLT data.
63 do_write(Output_file
*);
65 // Write to a map file.
67 do_print_to_mapfile(Mapfile
* mapfile
) const
68 { mapfile
->print_output_data(this, "** GOT PLT"); }
71 // A pointer to the Layout class, so that we can find the .dynamic
72 // section when we write out the GOT PLT section.
76 // A class to handle the PLT data.
77 // This is an abstract base class that handles most of the linker details
78 // but does not know the actual contents of PLT entries. The derived
79 // classes below fill in those details.
81 class Output_data_plt_i386
: public Output_section_data
84 typedef Output_data_reloc
<elfcpp::SHT_REL
, true, 32, false> Reloc_section
;
86 Output_data_plt_i386(Layout
*, uint64_t addralign
,
87 Output_data_got_plt_i386
*, Output_data_space
*);
89 // Add an entry to the PLT.
91 add_entry(Symbol_table
*, Layout
*, Symbol
* gsym
);
93 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
95 add_local_ifunc_entry(Symbol_table
*, Layout
*,
96 Sized_relobj_file
<32, false>* relobj
,
97 unsigned int local_sym_index
);
99 // Return the .rel.plt section data.
102 { return this->rel_
; }
104 // Return where the TLS_DESC relocations should go.
106 rel_tls_desc(Layout
*);
108 // Return where the IRELATIVE relocations should go.
110 rel_irelative(Symbol_table
*, Layout
*);
112 // Return whether we created a section for IRELATIVE relocations.
114 has_irelative_section() const
115 { return this->irelative_rel_
!= NULL
; }
117 // Return the number of PLT entries.
120 { return this->count_
+ this->irelative_count_
; }
122 // Return the offset of the first non-reserved PLT entry.
124 first_plt_entry_offset()
125 { return this->get_plt_entry_size(); }
127 // Return the size of a PLT entry.
129 get_plt_entry_size() const
130 { return this->do_get_plt_entry_size(); }
132 // Return the PLT address to use for a global symbol.
134 address_for_global(const Symbol
*);
136 // Return the PLT address to use for a local symbol.
138 address_for_local(const Relobj
*, unsigned int symndx
);
140 // Add .eh_frame information for the PLT.
142 add_eh_frame(Layout
* layout
)
143 { this->do_add_eh_frame(layout
); }
146 // Fill the first PLT entry, given the pointer to the PLT section data
147 // and the runtime address of the GOT.
149 fill_first_plt_entry(unsigned char* pov
,
150 elfcpp::Elf_types
<32>::Elf_Addr got_address
)
151 { this->do_fill_first_plt_entry(pov
, got_address
); }
153 // Fill a normal PLT entry, given the pointer to the entry's data in the
154 // section, the runtime address of the GOT, the offset into the GOT of
155 // the corresponding slot, the offset into the relocation section of the
156 // corresponding reloc, and the offset of this entry within the whole
157 // PLT. Return the offset from this PLT entry's runtime address that
158 // should be used to compute the initial value of the GOT slot.
160 fill_plt_entry(unsigned char* pov
,
161 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
162 unsigned int got_offset
,
163 unsigned int plt_offset
,
164 unsigned int plt_rel_offset
)
166 return this->do_fill_plt_entry(pov
, got_address
, got_offset
,
167 plt_offset
, plt_rel_offset
);
171 do_get_plt_entry_size() const = 0;
174 do_fill_first_plt_entry(unsigned char* pov
,
175 elfcpp::Elf_types
<32>::Elf_Addr got_address
) = 0;
178 do_fill_plt_entry(unsigned char* pov
,
179 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
180 unsigned int got_offset
,
181 unsigned int plt_offset
,
182 unsigned int plt_rel_offset
) = 0;
185 do_add_eh_frame(Layout
*) = 0;
188 do_adjust_output_section(Output_section
* os
);
190 // Write to a map file.
192 do_print_to_mapfile(Mapfile
* mapfile
) const
193 { mapfile
->print_output_data(this, _("** PLT")); }
195 // The .eh_frame unwind information for the PLT.
196 // The CIE is common across variants of the PLT format.
197 static const int plt_eh_frame_cie_size
= 16;
198 static const unsigned char plt_eh_frame_cie
[plt_eh_frame_cie_size
];
201 // Set the final size.
203 set_final_data_size()
205 this->set_data_size((this->count_
+ this->irelative_count_
+ 1)
206 * this->get_plt_entry_size());
209 // Write out the PLT data.
211 do_write(Output_file
*);
213 // We keep a list of global STT_GNU_IFUNC symbols, each with its
214 // offset in the GOT.
218 unsigned int got_offset
;
221 // We keep a list of local STT_GNU_IFUNC symbols, each with its
222 // offset in the GOT.
225 Sized_relobj_file
<32, false>* object
;
226 unsigned int local_sym_index
;
227 unsigned int got_offset
;
230 // The reloc section.
232 // The TLS_DESC relocations, if necessary. These must follow the
233 // regular PLT relocs.
234 Reloc_section
* tls_desc_rel_
;
235 // The IRELATIVE relocations, if necessary. These must follow the
236 // regular relocatoins and the TLS_DESC relocations.
237 Reloc_section
* irelative_rel_
;
238 // The .got.plt section.
239 Output_data_got_plt_i386
* got_plt_
;
240 // The part of the .got.plt section used for IRELATIVE relocs.
241 Output_data_space
* got_irelative_
;
242 // The number of PLT entries.
244 // Number of PLT entries with R_386_IRELATIVE relocs. These follow
245 // the regular PLT entries.
246 unsigned int irelative_count_
;
247 // Global STT_GNU_IFUNC symbols.
248 std::vector
<Global_ifunc
> global_ifuncs_
;
249 // Local STT_GNU_IFUNC symbols.
250 std::vector
<Local_ifunc
> local_ifuncs_
;
253 // This is an abstract class for the standard PLT layout.
254 // The derived classes below handle the actual PLT contents
255 // for the executable (non-PIC) and shared-library (PIC) cases.
256 // The unwind information is uniform across those two, so it's here.
258 class Output_data_plt_i386_standard
: public Output_data_plt_i386
261 Output_data_plt_i386_standard(Layout
* layout
,
262 Output_data_got_plt_i386
* got_plt
,
263 Output_data_space
* got_irelative
)
264 : Output_data_plt_i386(layout
, plt_entry_size
, got_plt
, got_irelative
)
269 do_get_plt_entry_size() const
270 { return plt_entry_size
; }
273 do_add_eh_frame(Layout
* layout
)
275 layout
->add_eh_frame_for_plt(this, plt_eh_frame_cie
, plt_eh_frame_cie_size
,
276 plt_eh_frame_fde
, plt_eh_frame_fde_size
);
279 // The size of an entry in the PLT.
280 static const int plt_entry_size
= 16;
282 // The .eh_frame unwind information for the PLT.
283 static const int plt_eh_frame_fde_size
= 32;
284 static const unsigned char plt_eh_frame_fde
[plt_eh_frame_fde_size
];
287 // Actually fill the PLT contents for an executable (non-PIC).
289 class Output_data_plt_i386_exec
: public Output_data_plt_i386_standard
292 Output_data_plt_i386_exec(Layout
* layout
,
293 Output_data_got_plt_i386
* got_plt
,
294 Output_data_space
* got_irelative
)
295 : Output_data_plt_i386_standard(layout
, got_plt
, got_irelative
)
300 do_fill_first_plt_entry(unsigned char* pov
,
301 elfcpp::Elf_types
<32>::Elf_Addr got_address
);
304 do_fill_plt_entry(unsigned char* pov
,
305 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
306 unsigned int got_offset
,
307 unsigned int plt_offset
,
308 unsigned int plt_rel_offset
);
311 // The first entry in the PLT for an executable.
312 static const unsigned char first_plt_entry
[plt_entry_size
];
314 // Other entries in the PLT for an executable.
315 static const unsigned char plt_entry
[plt_entry_size
];
318 // Actually fill the PLT contents for a shared library (PIC).
320 class Output_data_plt_i386_dyn
: public Output_data_plt_i386_standard
323 Output_data_plt_i386_dyn(Layout
* layout
,
324 Output_data_got_plt_i386
* got_plt
,
325 Output_data_space
* got_irelative
)
326 : Output_data_plt_i386_standard(layout
, got_plt
, got_irelative
)
331 do_fill_first_plt_entry(unsigned char* pov
, elfcpp::Elf_types
<32>::Elf_Addr
);
334 do_fill_plt_entry(unsigned char* pov
,
335 elfcpp::Elf_types
<32>::Elf_Addr
,
336 unsigned int got_offset
,
337 unsigned int plt_offset
,
338 unsigned int plt_rel_offset
);
341 // The first entry in the PLT for a shared object.
342 static const unsigned char first_plt_entry
[plt_entry_size
];
344 // Other entries in the PLT for a shared object.
345 static const unsigned char plt_entry
[plt_entry_size
];
348 // The i386 target class.
349 // TLS info comes from
350 // http://people.redhat.com/drepper/tls.pdf
351 // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
353 class Target_i386
: public Sized_target
<32, false>
356 typedef Output_data_reloc
<elfcpp::SHT_REL
, true, 32, false> Reloc_section
;
358 Target_i386(const Target::Target_info
* info
= &i386_info
)
359 : Sized_target
<32, false>(info
),
360 got_(NULL
), plt_(NULL
), got_plt_(NULL
), got_irelative_(NULL
),
361 got_tlsdesc_(NULL
), global_offset_table_(NULL
), rel_dyn_(NULL
),
362 rel_irelative_(NULL
), copy_relocs_(elfcpp::R_386_COPY
),
363 got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
366 // Process the relocations to determine unreferenced sections for
367 // garbage collection.
369 gc_process_relocs(Symbol_table
* symtab
,
371 Sized_relobj_file
<32, false>* object
,
372 unsigned int data_shndx
,
373 unsigned int sh_type
,
374 const unsigned char* prelocs
,
376 Output_section
* output_section
,
377 bool needs_special_offset_handling
,
378 size_t local_symbol_count
,
379 const unsigned char* plocal_symbols
);
381 // Scan the relocations to look for symbol adjustments.
383 scan_relocs(Symbol_table
* symtab
,
385 Sized_relobj_file
<32, false>* object
,
386 unsigned int data_shndx
,
387 unsigned int sh_type
,
388 const unsigned char* prelocs
,
390 Output_section
* output_section
,
391 bool needs_special_offset_handling
,
392 size_t local_symbol_count
,
393 const unsigned char* plocal_symbols
);
395 // Finalize the sections.
397 do_finalize_sections(Layout
*, const Input_objects
*, Symbol_table
*);
399 // Return the value to use for a dynamic which requires special
402 do_dynsym_value(const Symbol
*) const;
404 // Relocate a section.
406 relocate_section(const Relocate_info
<32, false>*,
407 unsigned int sh_type
,
408 const unsigned char* prelocs
,
410 Output_section
* output_section
,
411 bool needs_special_offset_handling
,
413 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
414 section_size_type view_size
,
415 const Reloc_symbol_changes
*);
417 // Scan the relocs during a relocatable link.
419 scan_relocatable_relocs(Symbol_table
* symtab
,
421 Sized_relobj_file
<32, false>* object
,
422 unsigned int data_shndx
,
423 unsigned int sh_type
,
424 const unsigned char* prelocs
,
426 Output_section
* output_section
,
427 bool needs_special_offset_handling
,
428 size_t local_symbol_count
,
429 const unsigned char* plocal_symbols
,
430 Relocatable_relocs
*);
432 // Scan the relocs for --emit-relocs.
434 emit_relocs_scan(Symbol_table
* symtab
,
436 Sized_relobj_file
<32, false>* object
,
437 unsigned int data_shndx
,
438 unsigned int sh_type
,
439 const unsigned char* prelocs
,
441 Output_section
* output_section
,
442 bool needs_special_offset_handling
,
443 size_t local_symbol_count
,
444 const unsigned char* plocal_syms
,
445 Relocatable_relocs
* rr
);
447 // Emit relocations for a section.
449 relocate_relocs(const Relocate_info
<32, false>*,
450 unsigned int sh_type
,
451 const unsigned char* prelocs
,
453 Output_section
* output_section
,
454 elfcpp::Elf_types
<32>::Elf_Off offset_in_output_section
,
456 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
457 section_size_type view_size
,
458 unsigned char* reloc_view
,
459 section_size_type reloc_view_size
);
461 // Return a string used to fill a code section with nops.
463 do_code_fill(section_size_type length
) const;
465 // Return whether SYM is defined by the ABI.
467 do_is_defined_by_abi(const Symbol
* sym
) const
468 { return strcmp(sym
->name(), "___tls_get_addr") == 0; }
470 // Return whether a symbol name implies a local label. The UnixWare
471 // 2.1 cc generates temporary symbols that start with .X, so we
472 // recognize them here. FIXME: do other SVR4 compilers also use .X?.
473 // If so, we should move the .X recognition into
474 // Target::do_is_local_label_name.
476 do_is_local_label_name(const char* name
) const
478 if (name
[0] == '.' && name
[1] == 'X')
480 return Target::do_is_local_label_name(name
);
483 // Return the PLT address to use for a global symbol.
485 do_plt_address_for_global(const Symbol
* gsym
) const
486 { return this->plt_section()->address_for_global(gsym
); }
489 do_plt_address_for_local(const Relobj
* relobj
, unsigned int symndx
) const
490 { return this->plt_section()->address_for_local(relobj
, symndx
); }
492 // We can tell whether we take the address of a function.
494 do_can_check_for_function_pointers() const
497 // Return the base for a DW_EH_PE_datarel encoding.
499 do_ehframe_datarel_base() const;
501 // Return whether SYM is call to a non-split function.
503 do_is_call_to_non_split(const Symbol
* sym
, const unsigned char*,
504 const unsigned char*, section_size_type
) const;
506 // Adjust -fsplit-stack code which calls non-split-stack code.
508 do_calls_non_split(Relobj
* object
, unsigned int shndx
,
509 section_offset_type fnoffset
, section_size_type fnsize
,
510 const unsigned char* prelocs
, size_t reloc_count
,
511 unsigned char* view
, section_size_type view_size
,
512 std::string
* from
, std::string
* to
) const;
514 // Return the size of the GOT section.
518 gold_assert(this->got_
!= NULL
);
519 return this->got_
->data_size();
522 // Return the number of entries in the GOT.
524 got_entry_count() const
526 if (this->got_
== NULL
)
528 return this->got_size() / 4;
531 // Return the number of entries in the PLT.
533 plt_entry_count() const;
535 // Return the offset of the first non-reserved PLT entry.
537 first_plt_entry_offset() const;
539 // Return the size of each PLT entry.
541 plt_entry_size() const;
544 // Instantiate the plt_ member.
545 // This chooses the right PLT flavor for an executable or a shared object.
546 Output_data_plt_i386
*
547 make_data_plt(Layout
* layout
,
548 Output_data_got_plt_i386
* got_plt
,
549 Output_data_space
* got_irelative
,
551 { return this->do_make_data_plt(layout
, got_plt
, got_irelative
, dyn
); }
553 virtual Output_data_plt_i386
*
554 do_make_data_plt(Layout
* layout
,
555 Output_data_got_plt_i386
* got_plt
,
556 Output_data_space
* got_irelative
,
560 return new Output_data_plt_i386_dyn(layout
, got_plt
, got_irelative
);
562 return new Output_data_plt_i386_exec(layout
, got_plt
, got_irelative
);
566 // The class which scans relocations.
571 get_reference_flags(unsigned int r_type
);
574 local(Symbol_table
* symtab
, Layout
* layout
, Target_i386
* target
,
575 Sized_relobj_file
<32, false>* object
,
576 unsigned int data_shndx
,
577 Output_section
* output_section
,
578 const elfcpp::Rel
<32, false>& reloc
, unsigned int r_type
,
579 const elfcpp::Sym
<32, false>& lsym
,
583 global(Symbol_table
* symtab
, Layout
* layout
, Target_i386
* target
,
584 Sized_relobj_file
<32, false>* object
,
585 unsigned int data_shndx
,
586 Output_section
* output_section
,
587 const elfcpp::Rel
<32, false>& reloc
, unsigned int r_type
,
591 local_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
593 Sized_relobj_file
<32, false>* object
,
594 unsigned int data_shndx
,
595 Output_section
* output_section
,
596 const elfcpp::Rel
<32, false>& reloc
,
598 const elfcpp::Sym
<32, false>& lsym
);
601 global_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
603 Sized_relobj_file
<32, false>* object
,
604 unsigned int data_shndx
,
605 Output_section
* output_section
,
606 const elfcpp::Rel
<32, false>& reloc
,
611 possible_function_pointer_reloc(unsigned int r_type
);
614 reloc_needs_plt_for_ifunc(Sized_relobj_file
<32, false>*,
615 unsigned int r_type
);
618 unsupported_reloc_local(Sized_relobj_file
<32, false>*, unsigned int r_type
);
621 unsupported_reloc_global(Sized_relobj_file
<32, false>*, unsigned int r_type
,
625 // The class which implements relocation.
630 : skip_call_tls_get_addr_(false),
631 local_dynamic_type_(LOCAL_DYNAMIC_NONE
)
636 if (this->skip_call_tls_get_addr_
)
638 // FIXME: This needs to specify the location somehow.
639 gold_error(_("missing expected TLS relocation"));
643 // Return whether the static relocation needs to be applied.
645 should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
648 Output_section
* output_section
);
650 // Do a relocation. Return false if the caller should not issue
651 // any warnings about this relocation.
653 relocate(const Relocate_info
<32, false>*, unsigned int,
654 Target_i386
*, Output_section
*, size_t, const unsigned char*,
655 const Sized_symbol
<32>*, const Symbol_value
<32>*,
656 unsigned char*, elfcpp::Elf_types
<32>::Elf_Addr
,
660 // Do a TLS relocation.
662 relocate_tls(const Relocate_info
<32, false>*, Target_i386
* target
,
663 size_t relnum
, const elfcpp::Rel
<32, false>&,
664 unsigned int r_type
, const Sized_symbol
<32>*,
665 const Symbol_value
<32>*,
666 unsigned char*, elfcpp::Elf_types
<32>::Elf_Addr
,
669 // Do a TLS General-Dynamic to Initial-Exec transition.
671 tls_gd_to_ie(const Relocate_info
<32, false>*, size_t relnum
,
672 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
673 elfcpp::Elf_types
<32>::Elf_Addr value
,
675 section_size_type view_size
);
677 // Do a TLS General-Dynamic to Local-Exec transition.
679 tls_gd_to_le(const Relocate_info
<32, false>*, size_t relnum
,
680 Output_segment
* tls_segment
,
681 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
682 elfcpp::Elf_types
<32>::Elf_Addr value
,
684 section_size_type view_size
);
686 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
689 tls_desc_gd_to_ie(const Relocate_info
<32, false>*, size_t relnum
,
690 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
691 elfcpp::Elf_types
<32>::Elf_Addr value
,
693 section_size_type view_size
);
695 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
698 tls_desc_gd_to_le(const Relocate_info
<32, false>*, size_t relnum
,
699 Output_segment
* tls_segment
,
700 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
701 elfcpp::Elf_types
<32>::Elf_Addr value
,
703 section_size_type view_size
);
705 // Do a TLS Local-Dynamic to Local-Exec transition.
707 tls_ld_to_le(const Relocate_info
<32, false>*, size_t relnum
,
708 Output_segment
* tls_segment
,
709 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
710 elfcpp::Elf_types
<32>::Elf_Addr value
,
712 section_size_type view_size
);
714 // Do a TLS Initial-Exec to Local-Exec transition.
716 tls_ie_to_le(const Relocate_info
<32, false>*, size_t relnum
,
717 Output_segment
* tls_segment
,
718 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
719 elfcpp::Elf_types
<32>::Elf_Addr value
,
721 section_size_type view_size
);
723 // We need to keep track of which type of local dynamic relocation
724 // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
725 enum Local_dynamic_type
732 // This is set if we should skip the next reloc, which should be a
733 // PLT32 reloc against ___tls_get_addr.
734 bool skip_call_tls_get_addr_
;
735 // The type of local dynamic relocation we have seen in the section
736 // being relocated, if any.
737 Local_dynamic_type local_dynamic_type_
;
740 // A class for inquiring about properties of a relocation,
741 // used while scanning relocs during a relocatable link and
742 // garbage collection.
743 class Classify_reloc
:
744 public gold::Default_classify_reloc
<elfcpp::SHT_REL
, 32, false>
747 typedef Reloc_types
<elfcpp::SHT_REL
, 32, false>::Reloc Reltype
;
749 // Return the explicit addend of the relocation (return 0 for SHT_REL).
750 static elfcpp::Elf_types
<32>::Elf_Swxword
751 get_r_addend(const Reltype
*)
754 // Return the size of the addend of the relocation (only used for SHT_REL).
756 get_size_for_reloc(unsigned int, Relobj
*);
759 // Adjust TLS relocation type based on the options and whether this
760 // is a local symbol.
761 static tls::Tls_optimization
762 optimize_tls_reloc(bool is_final
, int r_type
);
764 // Check if relocation against this symbol is a candidate for
766 // mov foo@GOT(%reg), %reg
768 // lea foo@GOTOFF(%reg), %reg.
770 can_convert_mov_to_lea(const Symbol
* gsym
)
772 gold_assert(gsym
!= NULL
);
773 return (gsym
->type() != elfcpp::STT_GNU_IFUNC
774 && !gsym
->is_undefined ()
775 && !gsym
->is_from_dynobj()
776 && !gsym
->is_preemptible()
777 && (!parameters
->options().shared()
778 || (gsym
->visibility() != elfcpp::STV_DEFAULT
779 && gsym
->visibility() != elfcpp::STV_PROTECTED
)
780 || parameters
->options().Bsymbolic())
781 && strcmp(gsym
->name(), "_DYNAMIC") != 0);
784 // Get the GOT section, creating it if necessary.
785 Output_data_got
<32, false>*
786 got_section(Symbol_table
*, Layout
*);
788 // Get the GOT PLT section.
789 Output_data_got_plt_i386
*
790 got_plt_section() const
792 gold_assert(this->got_plt_
!= NULL
);
793 return this->got_plt_
;
796 // Get the GOT section for TLSDESC entries.
797 Output_data_got
<32, false>*
798 got_tlsdesc_section() const
800 gold_assert(this->got_tlsdesc_
!= NULL
);
801 return this->got_tlsdesc_
;
804 // Create the PLT section.
806 make_plt_section(Symbol_table
* symtab
, Layout
* layout
);
808 // Create a PLT entry for a global symbol.
810 make_plt_entry(Symbol_table
*, Layout
*, Symbol
*);
812 // Create a PLT entry for a local STT_GNU_IFUNC symbol.
814 make_local_ifunc_plt_entry(Symbol_table
*, Layout
*,
815 Sized_relobj_file
<32, false>* relobj
,
816 unsigned int local_sym_index
);
818 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
820 define_tls_base_symbol(Symbol_table
*, Layout
*);
822 // Create a GOT entry for the TLS module index.
824 got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
825 Sized_relobj_file
<32, false>* object
);
827 // Get the PLT section.
828 Output_data_plt_i386
*
831 gold_assert(this->plt_
!= NULL
);
835 // Get the dynamic reloc section, creating it if necessary.
837 rel_dyn_section(Layout
*);
839 // Get the section to use for TLS_DESC relocations.
841 rel_tls_desc_section(Layout
*) const;
843 // Get the section to use for IRELATIVE relocations.
845 rel_irelative_section(Layout
*);
847 // Add a potential copy relocation.
849 copy_reloc(Symbol_table
* symtab
, Layout
* layout
,
850 Sized_relobj_file
<32, false>* object
,
851 unsigned int shndx
, Output_section
* output_section
,
852 Symbol
* sym
, const elfcpp::Rel
<32, false>& reloc
)
854 unsigned int r_type
= elfcpp::elf_r_type
<32>(reloc
.get_r_info());
855 this->copy_relocs_
.copy_reloc(symtab
, layout
,
856 symtab
->get_sized_symbol
<32>(sym
),
857 object
, shndx
, output_section
,
858 r_type
, reloc
.get_r_offset(), 0,
859 this->rel_dyn_section(layout
));
862 // Information about this specific target which we pass to the
863 // general Target structure.
864 static const Target::Target_info i386_info
;
866 // The types of GOT entries needed for this platform.
867 // These values are exposed to the ABI in an incremental link.
868 // Do not renumber existing values without changing the version
869 // number of the .gnu_incremental_inputs section.
872 GOT_TYPE_STANDARD
= 0, // GOT entry for a regular symbol
873 GOT_TYPE_TLS_NOFFSET
= 1, // GOT entry for negative TLS offset
874 GOT_TYPE_TLS_OFFSET
= 2, // GOT entry for positive TLS offset
875 GOT_TYPE_TLS_PAIR
= 3, // GOT entry for TLS module/offset pair
876 GOT_TYPE_TLS_DESC
= 4 // GOT entry for TLS_DESC pair
880 Output_data_got
<32, false>* got_
;
882 Output_data_plt_i386
* plt_
;
883 // The GOT PLT section.
884 Output_data_got_plt_i386
* got_plt_
;
885 // The GOT section for IRELATIVE relocations.
886 Output_data_space
* got_irelative_
;
887 // The GOT section for TLSDESC relocations.
888 Output_data_got
<32, false>* got_tlsdesc_
;
889 // The _GLOBAL_OFFSET_TABLE_ symbol.
890 Symbol
* global_offset_table_
;
891 // The dynamic reloc section.
892 Reloc_section
* rel_dyn_
;
893 // The section to use for IRELATIVE relocs.
894 Reloc_section
* rel_irelative_
;
895 // Relocs saved to avoid a COPY reloc.
896 Copy_relocs
<elfcpp::SHT_REL
, 32, false> copy_relocs_
;
897 // Offset of the GOT entry for the TLS module index.
898 unsigned int got_mod_index_offset_
;
899 // True if the _TLS_MODULE_BASE_ symbol has been defined.
900 bool tls_base_symbol_defined_
;
903 const Target::Target_info
Target_i386::i386_info
=
906 false, // is_big_endian
907 elfcpp::EM_386
, // machine_code
908 false, // has_make_symbol
909 false, // has_resolve
910 true, // has_code_fill
911 true, // is_default_stack_executable
912 true, // can_icf_inline_merge_sections
914 "/usr/lib/libc.so.1", // dynamic_linker
915 0x08048000, // default_text_segment_address
916 0x1000, // abi_pagesize (overridable by -z max-page-size)
917 0x1000, // common_pagesize (overridable by -z common-page-size)
918 false, // isolate_execinstr
920 elfcpp::SHN_UNDEF
, // small_common_shndx
921 elfcpp::SHN_UNDEF
, // large_common_shndx
922 0, // small_common_section_flags
923 0, // large_common_section_flags
924 NULL
, // attributes_section
925 NULL
, // attributes_vendor
926 "_start", // entry_symbol_name
927 32, // hash_entry_size
930 // Get the GOT section, creating it if necessary.
932 Output_data_got
<32, false>*
933 Target_i386::got_section(Symbol_table
* symtab
, Layout
* layout
)
935 if (this->got_
== NULL
)
937 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
939 this->got_
= new Output_data_got
<32, false>();
941 // When using -z now, we can treat .got.plt as a relro section.
942 // Without -z now, it is modified after program startup by lazy
944 bool is_got_plt_relro
= parameters
->options().now();
945 Output_section_order got_order
= (is_got_plt_relro
948 Output_section_order got_plt_order
= (is_got_plt_relro
950 : ORDER_NON_RELRO_FIRST
);
952 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
954 | elfcpp::SHF_WRITE
),
955 this->got_
, got_order
, true);
957 this->got_plt_
= new Output_data_got_plt_i386(layout
);
958 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
960 | elfcpp::SHF_WRITE
),
961 this->got_plt_
, got_plt_order
,
964 // The first three entries are reserved.
965 this->got_plt_
->set_current_data_size(3 * 4);
967 if (!is_got_plt_relro
)
969 // Those bytes can go into the relro segment.
970 layout
->increase_relro(3 * 4);
973 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
974 this->global_offset_table_
=
975 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
976 Symbol_table::PREDEFINED
,
978 0, 0, elfcpp::STT_OBJECT
,
980 elfcpp::STV_HIDDEN
, 0,
983 // If there are any IRELATIVE relocations, they get GOT entries
984 // in .got.plt after the jump slot relocations.
985 this->got_irelative_
= new Output_data_space(4, "** GOT IRELATIVE PLT");
986 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
988 | elfcpp::SHF_WRITE
),
989 this->got_irelative_
,
990 got_plt_order
, is_got_plt_relro
);
992 // If there are any TLSDESC relocations, they get GOT entries in
993 // .got.plt after the jump slot entries.
994 this->got_tlsdesc_
= new Output_data_got
<32, false>();
995 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
997 | elfcpp::SHF_WRITE
),
999 got_plt_order
, is_got_plt_relro
);
1005 // Get the dynamic reloc section, creating it if necessary.
1007 Target_i386::Reloc_section
*
1008 Target_i386::rel_dyn_section(Layout
* layout
)
1010 if (this->rel_dyn_
== NULL
)
1012 gold_assert(layout
!= NULL
);
1013 this->rel_dyn_
= new Reloc_section(parameters
->options().combreloc());
1014 layout
->add_output_section_data(".rel.dyn", elfcpp::SHT_REL
,
1015 elfcpp::SHF_ALLOC
, this->rel_dyn_
,
1016 ORDER_DYNAMIC_RELOCS
, false);
1018 return this->rel_dyn_
;
1021 // Get the section to use for IRELATIVE relocs, creating it if
1022 // necessary. These go in .rel.dyn, but only after all other dynamic
1023 // relocations. They need to follow the other dynamic relocations so
1024 // that they can refer to global variables initialized by those
1027 Target_i386::Reloc_section
*
1028 Target_i386::rel_irelative_section(Layout
* layout
)
1030 if (this->rel_irelative_
== NULL
)
1032 // Make sure we have already create the dynamic reloc section.
1033 this->rel_dyn_section(layout
);
1034 this->rel_irelative_
= new Reloc_section(false);
1035 layout
->add_output_section_data(".rel.dyn", elfcpp::SHT_REL
,
1036 elfcpp::SHF_ALLOC
, this->rel_irelative_
,
1037 ORDER_DYNAMIC_RELOCS
, false);
1038 gold_assert(this->rel_dyn_
->output_section()
1039 == this->rel_irelative_
->output_section());
1041 return this->rel_irelative_
;
1044 // Write the first three reserved words of the .got.plt section.
1045 // The remainder of the section is written while writing the PLT
1046 // in Output_data_plt_i386::do_write.
1049 Output_data_got_plt_i386::do_write(Output_file
* of
)
1051 // The first entry in the GOT is the address of the .dynamic section
1052 // aka the PT_DYNAMIC segment. The next two entries are reserved.
1053 // We saved space for them when we created the section in
1054 // Target_i386::got_section.
1055 const off_t got_file_offset
= this->offset();
1056 gold_assert(this->data_size() >= 12);
1057 unsigned char* const got_view
= of
->get_output_view(got_file_offset
, 12);
1058 Output_section
* dynamic
= this->layout_
->dynamic_section();
1059 uint32_t dynamic_addr
= dynamic
== NULL
? 0 : dynamic
->address();
1060 elfcpp::Swap
<32, false>::writeval(got_view
, dynamic_addr
);
1061 memset(got_view
+ 4, 0, 8);
1062 of
->write_output_view(got_file_offset
, 12, got_view
);
1065 // Create the PLT section. The ordinary .got section is an argument,
1066 // since we need to refer to the start. We also create our own .got
1067 // section just for PLT entries.
1069 Output_data_plt_i386::Output_data_plt_i386(Layout
* layout
,
1071 Output_data_got_plt_i386
* got_plt
,
1072 Output_data_space
* got_irelative
)
1073 : Output_section_data(addralign
),
1074 tls_desc_rel_(NULL
), irelative_rel_(NULL
), got_plt_(got_plt
),
1075 got_irelative_(got_irelative
), count_(0), irelative_count_(0),
1076 global_ifuncs_(), local_ifuncs_()
1078 this->rel_
= new Reloc_section(false);
1079 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
1080 elfcpp::SHF_ALLOC
, this->rel_
,
1081 ORDER_DYNAMIC_PLT_RELOCS
, false);
1085 Output_data_plt_i386::do_adjust_output_section(Output_section
* os
)
1087 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
1088 // linker, and so do we.
1092 // Add an entry to the PLT.
1095 Output_data_plt_i386::add_entry(Symbol_table
* symtab
, Layout
* layout
,
1098 gold_assert(!gsym
->has_plt_offset());
1100 // Every PLT entry needs a reloc.
1101 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1102 && gsym
->can_use_relative_reloc(false))
1104 gsym
->set_plt_offset(this->irelative_count_
* this->get_plt_entry_size());
1105 ++this->irelative_count_
;
1106 section_offset_type got_offset
=
1107 this->got_irelative_
->current_data_size();
1108 this->got_irelative_
->set_current_data_size(got_offset
+ 4);
1109 Reloc_section
* rel
= this->rel_irelative(symtab
, layout
);
1110 rel
->add_symbolless_global_addend(gsym
, elfcpp::R_386_IRELATIVE
,
1111 this->got_irelative_
, got_offset
);
1112 struct Global_ifunc gi
;
1114 gi
.got_offset
= got_offset
;
1115 this->global_ifuncs_
.push_back(gi
);
1119 // When setting the PLT offset we skip the initial reserved PLT
1121 gsym
->set_plt_offset((this->count_
+ 1) * this->get_plt_entry_size());
1125 section_offset_type got_offset
= this->got_plt_
->current_data_size();
1127 // Every PLT entry needs a GOT entry which points back to the
1128 // PLT entry (this will be changed by the dynamic linker,
1129 // normally lazily when the function is called).
1130 this->got_plt_
->set_current_data_size(got_offset
+ 4);
1132 gsym
->set_needs_dynsym_entry();
1133 this->rel_
->add_global(gsym
, elfcpp::R_386_JUMP_SLOT
, this->got_plt_
,
1137 // Note that we don't need to save the symbol. The contents of the
1138 // PLT are independent of which symbols are used. The symbols only
1139 // appear in the relocations.
1142 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
1146 Output_data_plt_i386::add_local_ifunc_entry(
1147 Symbol_table
* symtab
,
1149 Sized_relobj_file
<32, false>* relobj
,
1150 unsigned int local_sym_index
)
1152 unsigned int plt_offset
= this->irelative_count_
* this->get_plt_entry_size();
1153 ++this->irelative_count_
;
1155 section_offset_type got_offset
= this->got_irelative_
->current_data_size();
1157 // Every PLT entry needs a GOT entry which points back to the PLT
1159 this->got_irelative_
->set_current_data_size(got_offset
+ 4);
1161 // Every PLT entry needs a reloc.
1162 Reloc_section
* rel
= this->rel_irelative(symtab
, layout
);
1163 rel
->add_symbolless_local_addend(relobj
, local_sym_index
,
1164 elfcpp::R_386_IRELATIVE
,
1165 this->got_irelative_
, got_offset
);
1167 struct Local_ifunc li
;
1169 li
.local_sym_index
= local_sym_index
;
1170 li
.got_offset
= got_offset
;
1171 this->local_ifuncs_
.push_back(li
);
1176 // Return where the TLS_DESC relocations should go, creating it if
1177 // necessary. These follow the JUMP_SLOT relocations.
1179 Output_data_plt_i386::Reloc_section
*
1180 Output_data_plt_i386::rel_tls_desc(Layout
* layout
)
1182 if (this->tls_desc_rel_
== NULL
)
1184 this->tls_desc_rel_
= new Reloc_section(false);
1185 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
1186 elfcpp::SHF_ALLOC
, this->tls_desc_rel_
,
1187 ORDER_DYNAMIC_PLT_RELOCS
, false);
1188 gold_assert(this->tls_desc_rel_
->output_section()
1189 == this->rel_
->output_section());
1191 return this->tls_desc_rel_
;
1194 // Return where the IRELATIVE relocations should go in the PLT. These
1195 // follow the JUMP_SLOT and TLS_DESC relocations.
1197 Output_data_plt_i386::Reloc_section
*
1198 Output_data_plt_i386::rel_irelative(Symbol_table
* symtab
, Layout
* layout
)
1200 if (this->irelative_rel_
== NULL
)
1202 // Make sure we have a place for the TLS_DESC relocations, in
1203 // case we see any later on.
1204 this->rel_tls_desc(layout
);
1205 this->irelative_rel_
= new Reloc_section(false);
1206 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
1207 elfcpp::SHF_ALLOC
, this->irelative_rel_
,
1208 ORDER_DYNAMIC_PLT_RELOCS
, false);
1209 gold_assert(this->irelative_rel_
->output_section()
1210 == this->rel_
->output_section());
1212 if (parameters
->doing_static_link())
1214 // A statically linked executable will only have a .rel.plt
1215 // section to hold R_386_IRELATIVE relocs for STT_GNU_IFUNC
1216 // symbols. The library will use these symbols to locate
1217 // the IRELATIVE relocs at program startup time.
1218 symtab
->define_in_output_data("__rel_iplt_start", NULL
,
1219 Symbol_table::PREDEFINED
,
1220 this->irelative_rel_
, 0, 0,
1221 elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
1222 elfcpp::STV_HIDDEN
, 0, false, true);
1223 symtab
->define_in_output_data("__rel_iplt_end", NULL
,
1224 Symbol_table::PREDEFINED
,
1225 this->irelative_rel_
, 0, 0,
1226 elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
1227 elfcpp::STV_HIDDEN
, 0, true, true);
1230 return this->irelative_rel_
;
1233 // Return the PLT address to use for a global symbol.
1236 Output_data_plt_i386::address_for_global(const Symbol
* gsym
)
1238 uint64_t offset
= 0;
1239 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1240 && gsym
->can_use_relative_reloc(false))
1241 offset
= (this->count_
+ 1) * this->get_plt_entry_size();
1242 return this->address() + offset
+ gsym
->plt_offset();
1245 // Return the PLT address to use for a local symbol. These are always
1246 // IRELATIVE relocs.
1249 Output_data_plt_i386::address_for_local(const Relobj
* object
,
1252 return (this->address()
1253 + (this->count_
+ 1) * this->get_plt_entry_size()
1254 + object
->local_plt_offset(r_sym
));
1257 // The first entry in the PLT for an executable.
1259 const unsigned char Output_data_plt_i386_exec::first_plt_entry
[plt_entry_size
] =
1261 0xff, 0x35, // pushl contents of memory address
1262 0, 0, 0, 0, // replaced with address of .got + 4
1263 0xff, 0x25, // jmp indirect
1264 0, 0, 0, 0, // replaced with address of .got + 8
1265 0, 0, 0, 0 // unused
1269 Output_data_plt_i386_exec::do_fill_first_plt_entry(
1271 elfcpp::Elf_types
<32>::Elf_Addr got_address
)
1273 memcpy(pov
, first_plt_entry
, plt_entry_size
);
1274 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 4);
1275 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 8);
1278 // The first entry in the PLT for a shared object.
1280 const unsigned char Output_data_plt_i386_dyn::first_plt_entry
[plt_entry_size
] =
1282 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
1283 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
1284 0, 0, 0, 0 // unused
1288 Output_data_plt_i386_dyn::do_fill_first_plt_entry(
1290 elfcpp::Elf_types
<32>::Elf_Addr
)
1292 memcpy(pov
, first_plt_entry
, plt_entry_size
);
1295 // Subsequent entries in the PLT for an executable.
1297 const unsigned char Output_data_plt_i386_exec::plt_entry
[plt_entry_size
] =
1299 0xff, 0x25, // jmp indirect
1300 0, 0, 0, 0, // replaced with address of symbol in .got
1301 0x68, // pushl immediate
1302 0, 0, 0, 0, // replaced with offset into relocation table
1303 0xe9, // jmp relative
1304 0, 0, 0, 0 // replaced with offset to start of .plt
1308 Output_data_plt_i386_exec::do_fill_plt_entry(
1310 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
1311 unsigned int got_offset
,
1312 unsigned int plt_offset
,
1313 unsigned int plt_rel_offset
)
1315 memcpy(pov
, plt_entry
, plt_entry_size
);
1316 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
1317 got_address
+ got_offset
);
1318 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_rel_offset
);
1319 elfcpp::Swap
<32, false>::writeval(pov
+ 12, - (plt_offset
+ 12 + 4));
1323 // Subsequent entries in the PLT for a shared object.
1325 const unsigned char Output_data_plt_i386_dyn::plt_entry
[plt_entry_size
] =
1327 0xff, 0xa3, // jmp *offset(%ebx)
1328 0, 0, 0, 0, // replaced with offset of symbol in .got
1329 0x68, // pushl immediate
1330 0, 0, 0, 0, // replaced with offset into relocation table
1331 0xe9, // jmp relative
1332 0, 0, 0, 0 // replaced with offset to start of .plt
1336 Output_data_plt_i386_dyn::do_fill_plt_entry(unsigned char* pov
,
1337 elfcpp::Elf_types
<32>::Elf_Addr
,
1338 unsigned int got_offset
,
1339 unsigned int plt_offset
,
1340 unsigned int plt_rel_offset
)
1342 memcpy(pov
, plt_entry
, plt_entry_size
);
1343 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
1344 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_rel_offset
);
1345 elfcpp::Swap
<32, false>::writeval(pov
+ 12, - (plt_offset
+ 12 + 4));
1349 // The .eh_frame unwind information for the PLT.
1352 Output_data_plt_i386::plt_eh_frame_cie
[plt_eh_frame_cie_size
] =
1355 'z', // Augmentation: augmentation size included.
1356 'R', // Augmentation: FDE encoding included.
1357 '\0', // End of augmentation string.
1358 1, // Code alignment factor.
1359 0x7c, // Data alignment factor.
1360 8, // Return address column.
1361 1, // Augmentation size.
1362 (elfcpp::DW_EH_PE_pcrel
// FDE encoding.
1363 | elfcpp::DW_EH_PE_sdata4
),
1364 elfcpp::DW_CFA_def_cfa
, 4, 4, // DW_CFA_def_cfa: r4 (esp) ofs 4.
1365 elfcpp::DW_CFA_offset
+ 8, 1, // DW_CFA_offset: r8 (eip) at cfa-4.
1366 elfcpp::DW_CFA_nop
, // Align to 16 bytes.
1371 Output_data_plt_i386_standard::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
1373 0, 0, 0, 0, // Replaced with offset to .plt.
1374 0, 0, 0, 0, // Replaced with size of .plt.
1375 0, // Augmentation size.
1376 elfcpp::DW_CFA_def_cfa_offset
, 8, // DW_CFA_def_cfa_offset: 8.
1377 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
1378 elfcpp::DW_CFA_def_cfa_offset
, 12, // DW_CFA_def_cfa_offset: 12.
1379 elfcpp::DW_CFA_advance_loc
+ 10, // Advance 10 to __PLT__ + 16.
1380 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
1381 11, // Block length.
1382 elfcpp::DW_OP_breg4
, 4, // Push %esp + 4.
1383 elfcpp::DW_OP_breg8
, 0, // Push %eip.
1384 elfcpp::DW_OP_lit15
, // Push 0xf.
1385 elfcpp::DW_OP_and
, // & (%eip & 0xf).
1386 elfcpp::DW_OP_lit11
, // Push 0xb.
1387 elfcpp::DW_OP_ge
, // >= ((%eip & 0xf) >= 0xb)
1388 elfcpp::DW_OP_lit2
, // Push 2.
1389 elfcpp::DW_OP_shl
, // << (((%eip & 0xf) >= 0xb) << 2)
1390 elfcpp::DW_OP_plus
, // + ((((%eip&0xf)>=0xb)<<2)+%esp+4
1391 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
1397 // Write out the PLT. This uses the hand-coded instructions above,
1398 // and adjusts them as needed. This is all specified by the i386 ELF
1399 // Processor Supplement.
1402 Output_data_plt_i386::do_write(Output_file
* of
)
1404 const off_t offset
= this->offset();
1405 const section_size_type oview_size
=
1406 convert_to_section_size_type(this->data_size());
1407 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
1409 const off_t got_file_offset
= this->got_plt_
->offset();
1410 gold_assert(parameters
->incremental_update()
1411 || (got_file_offset
+ this->got_plt_
->data_size()
1412 == this->got_irelative_
->offset()));
1413 const section_size_type got_size
=
1414 convert_to_section_size_type(this->got_plt_
->data_size()
1415 + this->got_irelative_
->data_size());
1417 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
1420 unsigned char* pov
= oview
;
1422 elfcpp::Elf_types
<32>::Elf_Addr plt_address
= this->address();
1423 elfcpp::Elf_types
<32>::Elf_Addr got_address
= this->got_plt_
->address();
1425 this->fill_first_plt_entry(pov
, got_address
);
1426 pov
+= this->get_plt_entry_size();
1428 // The first three entries in the GOT are reserved, and are written
1429 // by Output_data_got_plt_i386::do_write.
1430 unsigned char* got_pov
= got_view
+ 12;
1432 const int rel_size
= elfcpp::Elf_sizes
<32>::rel_size
;
1434 unsigned int plt_offset
= this->get_plt_entry_size();
1435 unsigned int plt_rel_offset
= 0;
1436 unsigned int got_offset
= 12;
1437 const unsigned int count
= this->count_
+ this->irelative_count_
;
1438 for (unsigned int i
= 0;
1441 pov
+= this->get_plt_entry_size(),
1443 plt_offset
+= this->get_plt_entry_size(),
1444 plt_rel_offset
+= rel_size
,
1447 // Set and adjust the PLT entry itself.
1448 unsigned int lazy_offset
= this->fill_plt_entry(pov
,
1454 // Set the entry in the GOT.
1455 elfcpp::Swap
<32, false>::writeval(got_pov
,
1456 plt_address
+ plt_offset
+ lazy_offset
);
1459 // If any STT_GNU_IFUNC symbols have PLT entries, we need to change
1460 // the GOT to point to the actual symbol value, rather than point to
1461 // the PLT entry. That will let the dynamic linker call the right
1462 // function when resolving IRELATIVE relocations.
1463 unsigned char* got_irelative_view
= got_view
+ this->got_plt_
->data_size();
1464 for (std::vector
<Global_ifunc
>::const_iterator p
=
1465 this->global_ifuncs_
.begin();
1466 p
!= this->global_ifuncs_
.end();
1469 const Sized_symbol
<32>* ssym
=
1470 static_cast<const Sized_symbol
<32>*>(p
->sym
);
1471 elfcpp::Swap
<32, false>::writeval(got_irelative_view
+ p
->got_offset
,
1475 for (std::vector
<Local_ifunc
>::const_iterator p
=
1476 this->local_ifuncs_
.begin();
1477 p
!= this->local_ifuncs_
.end();
1480 const Symbol_value
<32>* psymval
=
1481 p
->object
->local_symbol(p
->local_sym_index
);
1482 elfcpp::Swap
<32, false>::writeval(got_irelative_view
+ p
->got_offset
,
1483 psymval
->value(p
->object
, 0));
1486 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
1487 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
1489 of
->write_output_view(offset
, oview_size
, oview
);
1490 of
->write_output_view(got_file_offset
, got_size
, got_view
);
1493 // Create the PLT section.
1496 Target_i386::make_plt_section(Symbol_table
* symtab
, Layout
* layout
)
1498 if (this->plt_
== NULL
)
1500 // Create the GOT sections first.
1501 this->got_section(symtab
, layout
);
1503 const bool dyn
= parameters
->options().output_is_position_independent();
1504 this->plt_
= this->make_data_plt(layout
,
1506 this->got_irelative_
,
1509 // Add unwind information if requested.
1510 if (parameters
->options().ld_generated_unwind_info())
1511 this->plt_
->add_eh_frame(layout
);
1513 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
1515 | elfcpp::SHF_EXECINSTR
),
1516 this->plt_
, ORDER_PLT
, false);
1518 // Make the sh_info field of .rel.plt point to .plt.
1519 Output_section
* rel_plt_os
= this->plt_
->rel_plt()->output_section();
1520 rel_plt_os
->set_info_section(this->plt_
->output_section());
1524 // Create a PLT entry for a global symbol.
1527 Target_i386::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
, Symbol
* gsym
)
1529 if (gsym
->has_plt_offset())
1531 if (this->plt_
== NULL
)
1532 this->make_plt_section(symtab
, layout
);
1533 this->plt_
->add_entry(symtab
, layout
, gsym
);
1536 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1539 Target_i386::make_local_ifunc_plt_entry(Symbol_table
* symtab
, Layout
* layout
,
1540 Sized_relobj_file
<32, false>* relobj
,
1541 unsigned int local_sym_index
)
1543 if (relobj
->local_has_plt_offset(local_sym_index
))
1545 if (this->plt_
== NULL
)
1546 this->make_plt_section(symtab
, layout
);
1547 unsigned int plt_offset
= this->plt_
->add_local_ifunc_entry(symtab
, layout
,
1550 relobj
->set_local_plt_offset(local_sym_index
, plt_offset
);
1553 // Return the number of entries in the PLT.
1556 Target_i386::plt_entry_count() const
1558 if (this->plt_
== NULL
)
1560 return this->plt_
->entry_count();
1563 // Return the offset of the first non-reserved PLT entry.
1566 Target_i386::first_plt_entry_offset() const
1568 return this->plt_
->first_plt_entry_offset();
1571 // Return the size of each PLT entry.
1574 Target_i386::plt_entry_size() const
1576 return this->plt_
->get_plt_entry_size();
1579 // Get the section to use for TLS_DESC relocations.
1581 Target_i386::Reloc_section
*
1582 Target_i386::rel_tls_desc_section(Layout
* layout
) const
1584 return this->plt_section()->rel_tls_desc(layout
);
1587 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1590 Target_i386::define_tls_base_symbol(Symbol_table
* symtab
, Layout
* layout
)
1592 if (this->tls_base_symbol_defined_
)
1595 Output_segment
* tls_segment
= layout
->tls_segment();
1596 if (tls_segment
!= NULL
)
1598 bool is_exec
= parameters
->options().output_is_executable();
1599 symtab
->define_in_output_segment("_TLS_MODULE_BASE_", NULL
,
1600 Symbol_table::PREDEFINED
,
1604 elfcpp::STV_HIDDEN
, 0,
1606 ? Symbol::SEGMENT_END
1607 : Symbol::SEGMENT_START
),
1610 this->tls_base_symbol_defined_
= true;
1613 // Create a GOT entry for the TLS module index.
1616 Target_i386::got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
1617 Sized_relobj_file
<32, false>* object
)
1619 if (this->got_mod_index_offset_
== -1U)
1621 gold_assert(symtab
!= NULL
&& layout
!= NULL
&& object
!= NULL
);
1622 Reloc_section
* rel_dyn
= this->rel_dyn_section(layout
);
1623 Output_data_got
<32, false>* got
= this->got_section(symtab
, layout
);
1624 unsigned int got_offset
= got
->add_constant(0);
1625 rel_dyn
->add_local(object
, 0, elfcpp::R_386_TLS_DTPMOD32
, got
,
1627 got
->add_constant(0);
1628 this->got_mod_index_offset_
= got_offset
;
1630 return this->got_mod_index_offset_
;
1633 // Optimize the TLS relocation type based on what we know about the
1634 // symbol. IS_FINAL is true if the final address of this symbol is
1635 // known at link time.
1637 tls::Tls_optimization
1638 Target_i386::optimize_tls_reloc(bool is_final
, int r_type
)
1640 // If we are generating a shared library, then we can't do anything
1642 if (parameters
->options().shared())
1643 return tls::TLSOPT_NONE
;
1647 case elfcpp::R_386_TLS_GD
:
1648 case elfcpp::R_386_TLS_GOTDESC
:
1649 case elfcpp::R_386_TLS_DESC_CALL
:
1650 // These are General-Dynamic which permits fully general TLS
1651 // access. Since we know that we are generating an executable,
1652 // we can convert this to Initial-Exec. If we also know that
1653 // this is a local symbol, we can further switch to Local-Exec.
1655 return tls::TLSOPT_TO_LE
;
1656 return tls::TLSOPT_TO_IE
;
1658 case elfcpp::R_386_TLS_LDM
:
1659 // This is Local-Dynamic, which refers to a local symbol in the
1660 // dynamic TLS block. Since we know that we generating an
1661 // executable, we can switch to Local-Exec.
1662 return tls::TLSOPT_TO_LE
;
1664 case elfcpp::R_386_TLS_LDO_32
:
1665 // Another type of Local-Dynamic relocation.
1666 return tls::TLSOPT_TO_LE
;
1668 case elfcpp::R_386_TLS_IE
:
1669 case elfcpp::R_386_TLS_GOTIE
:
1670 case elfcpp::R_386_TLS_IE_32
:
1671 // These are Initial-Exec relocs which get the thread offset
1672 // from the GOT. If we know that we are linking against the
1673 // local symbol, we can switch to Local-Exec, which links the
1674 // thread offset into the instruction.
1676 return tls::TLSOPT_TO_LE
;
1677 return tls::TLSOPT_NONE
;
1679 case elfcpp::R_386_TLS_LE
:
1680 case elfcpp::R_386_TLS_LE_32
:
1681 // When we already have Local-Exec, there is nothing further we
1683 return tls::TLSOPT_NONE
;
1690 // Get the Reference_flags for a particular relocation.
1693 Target_i386::Scan::get_reference_flags(unsigned int r_type
)
1697 case elfcpp::R_386_NONE
:
1698 case elfcpp::R_386_GNU_VTINHERIT
:
1699 case elfcpp::R_386_GNU_VTENTRY
:
1700 case elfcpp::R_386_GOTPC
:
1701 // No symbol reference.
1704 case elfcpp::R_386_32
:
1705 case elfcpp::R_386_16
:
1706 case elfcpp::R_386_8
:
1707 return Symbol::ABSOLUTE_REF
;
1709 case elfcpp::R_386_PC32
:
1710 case elfcpp::R_386_PC16
:
1711 case elfcpp::R_386_PC8
:
1712 case elfcpp::R_386_GOTOFF
:
1713 return Symbol::RELATIVE_REF
;
1715 case elfcpp::R_386_PLT32
:
1716 return Symbol::FUNCTION_CALL
| Symbol::RELATIVE_REF
;
1718 case elfcpp::R_386_GOT32
:
1719 case elfcpp::R_386_GOT32X
:
1721 return Symbol::ABSOLUTE_REF
;
1723 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1724 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1725 case elfcpp::R_386_TLS_DESC_CALL
:
1726 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1727 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1728 case elfcpp::R_386_TLS_IE
: // Initial-exec
1729 case elfcpp::R_386_TLS_IE_32
:
1730 case elfcpp::R_386_TLS_GOTIE
:
1731 case elfcpp::R_386_TLS_LE
: // Local-exec
1732 case elfcpp::R_386_TLS_LE_32
:
1733 return Symbol::TLS_REF
;
1735 case elfcpp::R_386_COPY
:
1736 case elfcpp::R_386_GLOB_DAT
:
1737 case elfcpp::R_386_JUMP_SLOT
:
1738 case elfcpp::R_386_RELATIVE
:
1739 case elfcpp::R_386_IRELATIVE
:
1740 case elfcpp::R_386_TLS_TPOFF
:
1741 case elfcpp::R_386_TLS_DTPMOD32
:
1742 case elfcpp::R_386_TLS_DTPOFF32
:
1743 case elfcpp::R_386_TLS_TPOFF32
:
1744 case elfcpp::R_386_TLS_DESC
:
1745 case elfcpp::R_386_32PLT
:
1746 case elfcpp::R_386_TLS_GD_32
:
1747 case elfcpp::R_386_TLS_GD_PUSH
:
1748 case elfcpp::R_386_TLS_GD_CALL
:
1749 case elfcpp::R_386_TLS_GD_POP
:
1750 case elfcpp::R_386_TLS_LDM_32
:
1751 case elfcpp::R_386_TLS_LDM_PUSH
:
1752 case elfcpp::R_386_TLS_LDM_CALL
:
1753 case elfcpp::R_386_TLS_LDM_POP
:
1754 case elfcpp::R_386_USED_BY_INTEL_200
:
1756 // Not expected. We will give an error later.
1761 // Report an unsupported relocation against a local symbol.
1764 Target_i386::Scan::unsupported_reloc_local(Sized_relobj_file
<32, false>* object
,
1765 unsigned int r_type
)
1767 gold_error(_("%s: unsupported reloc %u against local symbol"),
1768 object
->name().c_str(), r_type
);
1771 // Return whether we need to make a PLT entry for a relocation of a
1772 // given type against a STT_GNU_IFUNC symbol.
1775 Target_i386::Scan::reloc_needs_plt_for_ifunc(
1776 Sized_relobj_file
<32, false>* object
,
1777 unsigned int r_type
)
1779 int flags
= Scan::get_reference_flags(r_type
);
1780 if (flags
& Symbol::TLS_REF
)
1781 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
1782 object
->name().c_str(), r_type
);
1786 // Scan a relocation for a local symbol.
1789 Target_i386::Scan::local(Symbol_table
* symtab
,
1791 Target_i386
* target
,
1792 Sized_relobj_file
<32, false>* object
,
1793 unsigned int data_shndx
,
1794 Output_section
* output_section
,
1795 const elfcpp::Rel
<32, false>& reloc
,
1796 unsigned int r_type
,
1797 const elfcpp::Sym
<32, false>& lsym
,
1803 // A local STT_GNU_IFUNC symbol may require a PLT entry.
1804 if (lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
1805 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
1807 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1808 target
->make_local_ifunc_plt_entry(symtab
, layout
, object
, r_sym
);
1813 case elfcpp::R_386_NONE
:
1814 case elfcpp::R_386_GNU_VTINHERIT
:
1815 case elfcpp::R_386_GNU_VTENTRY
:
1818 case elfcpp::R_386_32
:
1819 // If building a shared library (or a position-independent
1820 // executable), we need to create a dynamic relocation for
1821 // this location. The relocation applied at link time will
1822 // apply the link-time value, so we flag the location with
1823 // an R_386_RELATIVE relocation so the dynamic loader can
1824 // relocate it easily.
1825 if (parameters
->options().output_is_position_independent())
1827 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1828 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1829 rel_dyn
->add_local_relative(object
, r_sym
, elfcpp::R_386_RELATIVE
,
1830 output_section
, data_shndx
,
1831 reloc
.get_r_offset());
1835 case elfcpp::R_386_16
:
1836 case elfcpp::R_386_8
:
1837 // If building a shared library (or a position-independent
1838 // executable), we need to create a dynamic relocation for
1839 // this location. Because the addend needs to remain in the
1840 // data section, we need to be careful not to apply this
1841 // relocation statically.
1842 if (parameters
->options().output_is_position_independent())
1844 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1845 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1846 if (lsym
.get_st_type() != elfcpp::STT_SECTION
)
1847 rel_dyn
->add_local(object
, r_sym
, r_type
, output_section
,
1848 data_shndx
, reloc
.get_r_offset());
1851 gold_assert(lsym
.get_st_value() == 0);
1852 unsigned int shndx
= lsym
.get_st_shndx();
1854 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
,
1857 object
->error(_("section symbol %u has bad shndx %u"),
1860 rel_dyn
->add_local_section(object
, shndx
,
1861 r_type
, output_section
,
1862 data_shndx
, reloc
.get_r_offset());
1867 case elfcpp::R_386_PC32
:
1868 case elfcpp::R_386_PC16
:
1869 case elfcpp::R_386_PC8
:
1872 case elfcpp::R_386_PLT32
:
1873 // Since we know this is a local symbol, we can handle this as a
1877 case elfcpp::R_386_GOTOFF
:
1878 case elfcpp::R_386_GOTPC
:
1879 // We need a GOT section.
1880 target
->got_section(symtab
, layout
);
1883 case elfcpp::R_386_GOT32
:
1884 case elfcpp::R_386_GOT32X
:
1886 // We need GOT section.
1887 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
1889 // If the relocation symbol isn't IFUNC,
1890 // and is local, then we will convert
1891 // mov foo@GOT(%reg), %reg
1893 // lea foo@GOTOFF(%reg), %reg
1894 // in Relocate::relocate.
1895 if (reloc
.get_r_offset() >= 2
1896 && lsym
.get_st_type() != elfcpp::STT_GNU_IFUNC
)
1898 section_size_type stype
;
1899 const unsigned char* view
= object
->section_contents(data_shndx
,
1901 if (view
[reloc
.get_r_offset() - 2] == 0x8b)
1905 // Otherwise, the symbol requires a GOT entry.
1906 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1908 // For a STT_GNU_IFUNC symbol we want the PLT offset. That
1909 // lets function pointers compare correctly with shared
1910 // libraries. Otherwise we would need an IRELATIVE reloc.
1912 if (lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
)
1913 is_new
= got
->add_local_plt(object
, r_sym
, GOT_TYPE_STANDARD
);
1915 is_new
= got
->add_local(object
, r_sym
, GOT_TYPE_STANDARD
);
1918 // If we are generating a shared object, we need to add a
1919 // dynamic RELATIVE relocation for this symbol's GOT entry.
1920 if (parameters
->options().output_is_position_independent())
1922 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1923 unsigned int got_offset
=
1924 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
);
1925 rel_dyn
->add_local_relative(object
, r_sym
,
1926 elfcpp::R_386_RELATIVE
,
1933 // These are relocations which should only be seen by the
1934 // dynamic linker, and should never be seen here.
1935 case elfcpp::R_386_COPY
:
1936 case elfcpp::R_386_GLOB_DAT
:
1937 case elfcpp::R_386_JUMP_SLOT
:
1938 case elfcpp::R_386_RELATIVE
:
1939 case elfcpp::R_386_IRELATIVE
:
1940 case elfcpp::R_386_TLS_TPOFF
:
1941 case elfcpp::R_386_TLS_DTPMOD32
:
1942 case elfcpp::R_386_TLS_DTPOFF32
:
1943 case elfcpp::R_386_TLS_TPOFF32
:
1944 case elfcpp::R_386_TLS_DESC
:
1945 gold_error(_("%s: unexpected reloc %u in object file"),
1946 object
->name().c_str(), r_type
);
1949 // These are initial TLS relocs, which are expected when
1951 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1952 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1953 case elfcpp::R_386_TLS_DESC_CALL
:
1954 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1955 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1956 case elfcpp::R_386_TLS_IE
: // Initial-exec
1957 case elfcpp::R_386_TLS_IE_32
:
1958 case elfcpp::R_386_TLS_GOTIE
:
1959 case elfcpp::R_386_TLS_LE
: // Local-exec
1960 case elfcpp::R_386_TLS_LE_32
:
1962 bool output_is_shared
= parameters
->options().shared();
1963 const tls::Tls_optimization optimized_type
1964 = Target_i386::optimize_tls_reloc(!output_is_shared
, r_type
);
1967 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1968 if (optimized_type
== tls::TLSOPT_NONE
)
1970 // Create a pair of GOT entries for the module index and
1971 // dtv-relative offset.
1972 Output_data_got
<32, false>* got
1973 = target
->got_section(symtab
, layout
);
1974 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1975 unsigned int shndx
= lsym
.get_st_shndx();
1977 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
1979 object
->error(_("local symbol %u has bad shndx %u"),
1982 got
->add_local_pair_with_rel(object
, r_sym
, shndx
,
1984 target
->rel_dyn_section(layout
),
1985 elfcpp::R_386_TLS_DTPMOD32
);
1987 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1988 unsupported_reloc_local(object
, r_type
);
1991 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva)
1992 target
->define_tls_base_symbol(symtab
, layout
);
1993 if (optimized_type
== tls::TLSOPT_NONE
)
1995 // Create a double GOT entry with an R_386_TLS_DESC
1996 // reloc. The R_386_TLS_DESC reloc is resolved
1997 // lazily, so the GOT entry needs to be in an area in
1998 // .got.plt, not .got. Call got_section to make sure
1999 // the section has been created.
2000 target
->got_section(symtab
, layout
);
2001 Output_data_got
<32, false>* got
= target
->got_tlsdesc_section();
2002 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
2003 if (!object
->local_has_got_offset(r_sym
, GOT_TYPE_TLS_DESC
))
2005 unsigned int got_offset
= got
->add_constant(0);
2006 // The local symbol value is stored in the second
2008 got
->add_local(object
, r_sym
, GOT_TYPE_TLS_DESC
);
2009 // That set the GOT offset of the local symbol to
2010 // point to the second entry, but we want it to
2011 // point to the first.
2012 object
->set_local_got_offset(r_sym
, GOT_TYPE_TLS_DESC
,
2014 Reloc_section
* rt
= target
->rel_tls_desc_section(layout
);
2015 rt
->add_absolute(elfcpp::R_386_TLS_DESC
, got
, got_offset
);
2018 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2019 unsupported_reloc_local(object
, r_type
);
2022 case elfcpp::R_386_TLS_DESC_CALL
:
2025 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2026 if (optimized_type
== tls::TLSOPT_NONE
)
2028 // Create a GOT entry for the module index.
2029 target
->got_mod_index_entry(symtab
, layout
, object
);
2031 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2032 unsupported_reloc_local(object
, r_type
);
2035 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2038 case elfcpp::R_386_TLS_IE
: // Initial-exec
2039 case elfcpp::R_386_TLS_IE_32
:
2040 case elfcpp::R_386_TLS_GOTIE
:
2041 layout
->set_has_static_tls();
2042 if (optimized_type
== tls::TLSOPT_NONE
)
2044 // For the R_386_TLS_IE relocation, we need to create a
2045 // dynamic relocation when building a shared library.
2046 if (r_type
== elfcpp::R_386_TLS_IE
2047 && parameters
->options().shared())
2049 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2051 = elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
2052 rel_dyn
->add_local_relative(object
, r_sym
,
2053 elfcpp::R_386_RELATIVE
,
2054 output_section
, data_shndx
,
2055 reloc
.get_r_offset());
2057 // Create a GOT entry for the tp-relative offset.
2058 Output_data_got
<32, false>* got
2059 = target
->got_section(symtab
, layout
);
2060 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
2061 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2062 ? elfcpp::R_386_TLS_TPOFF32
2063 : elfcpp::R_386_TLS_TPOFF
);
2064 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2065 ? GOT_TYPE_TLS_OFFSET
2066 : GOT_TYPE_TLS_NOFFSET
);
2067 got
->add_local_with_rel(object
, r_sym
, got_type
,
2068 target
->rel_dyn_section(layout
),
2071 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2072 unsupported_reloc_local(object
, r_type
);
2075 case elfcpp::R_386_TLS_LE
: // Local-exec
2076 case elfcpp::R_386_TLS_LE_32
:
2077 layout
->set_has_static_tls();
2078 if (output_is_shared
)
2080 // We need to create a dynamic relocation.
2081 gold_assert(lsym
.get_st_type() != elfcpp::STT_SECTION
);
2082 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
2083 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
2084 ? elfcpp::R_386_TLS_TPOFF32
2085 : elfcpp::R_386_TLS_TPOFF
);
2086 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2087 rel_dyn
->add_local(object
, r_sym
, dyn_r_type
, output_section
,
2088 data_shndx
, reloc
.get_r_offset());
2098 case elfcpp::R_386_32PLT
:
2099 case elfcpp::R_386_TLS_GD_32
:
2100 case elfcpp::R_386_TLS_GD_PUSH
:
2101 case elfcpp::R_386_TLS_GD_CALL
:
2102 case elfcpp::R_386_TLS_GD_POP
:
2103 case elfcpp::R_386_TLS_LDM_32
:
2104 case elfcpp::R_386_TLS_LDM_PUSH
:
2105 case elfcpp::R_386_TLS_LDM_CALL
:
2106 case elfcpp::R_386_TLS_LDM_POP
:
2107 case elfcpp::R_386_USED_BY_INTEL_200
:
2109 unsupported_reloc_local(object
, r_type
);
2114 // Report an unsupported relocation against a global symbol.
2117 Target_i386::Scan::unsupported_reloc_global(
2118 Sized_relobj_file
<32, false>* object
,
2119 unsigned int r_type
,
2122 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
2123 object
->name().c_str(), r_type
, gsym
->demangled_name().c_str());
2127 Target_i386::Scan::possible_function_pointer_reloc(unsigned int r_type
)
2131 case elfcpp::R_386_32
:
2132 case elfcpp::R_386_16
:
2133 case elfcpp::R_386_8
:
2134 case elfcpp::R_386_GOTOFF
:
2135 case elfcpp::R_386_GOT32
:
2136 case elfcpp::R_386_GOT32X
:
2147 Target_i386::Scan::local_reloc_may_be_function_pointer(
2151 Sized_relobj_file
<32, false>* ,
2154 const elfcpp::Rel
<32, false>& ,
2155 unsigned int r_type
,
2156 const elfcpp::Sym
<32, false>&)
2158 return possible_function_pointer_reloc(r_type
);
2162 Target_i386::Scan::global_reloc_may_be_function_pointer(
2166 Sized_relobj_file
<32, false>* ,
2169 const elfcpp::Rel
<32, false>& ,
2170 unsigned int r_type
,
2173 return possible_function_pointer_reloc(r_type
);
2176 // Scan a relocation for a global symbol.
2179 Target_i386::Scan::global(Symbol_table
* symtab
,
2181 Target_i386
* target
,
2182 Sized_relobj_file
<32, false>* object
,
2183 unsigned int data_shndx
,
2184 Output_section
* output_section
,
2185 const elfcpp::Rel
<32, false>& reloc
,
2186 unsigned int r_type
,
2189 // A STT_GNU_IFUNC symbol may require a PLT entry.
2190 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
2191 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
2192 target
->make_plt_entry(symtab
, layout
, gsym
);
2196 case elfcpp::R_386_NONE
:
2197 case elfcpp::R_386_GNU_VTINHERIT
:
2198 case elfcpp::R_386_GNU_VTENTRY
:
2201 case elfcpp::R_386_32
:
2202 case elfcpp::R_386_16
:
2203 case elfcpp::R_386_8
:
2205 // Make a PLT entry if necessary.
2206 if (gsym
->needs_plt_entry())
2208 target
->make_plt_entry(symtab
, layout
, gsym
);
2209 // Since this is not a PC-relative relocation, we may be
2210 // taking the address of a function. In that case we need to
2211 // set the entry in the dynamic symbol table to the address of
2213 if (gsym
->is_from_dynobj() && !parameters
->options().shared())
2214 gsym
->set_needs_dynsym_value();
2216 // Make a dynamic relocation if necessary.
2217 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
2219 if (!parameters
->options().output_is_position_independent()
2220 && gsym
->may_need_copy_reloc())
2222 target
->copy_reloc(symtab
, layout
, object
,
2223 data_shndx
, output_section
, gsym
, reloc
);
2225 else if (r_type
== elfcpp::R_386_32
2226 && gsym
->type() == elfcpp::STT_GNU_IFUNC
2227 && gsym
->can_use_relative_reloc(false)
2228 && !gsym
->is_from_dynobj()
2229 && !gsym
->is_undefined()
2230 && !gsym
->is_preemptible())
2232 // Use an IRELATIVE reloc for a locally defined
2233 // STT_GNU_IFUNC symbol. This makes a function
2234 // address in a PIE executable match the address in a
2235 // shared library that it links against.
2236 Reloc_section
* rel_dyn
= target
->rel_irelative_section(layout
);
2237 rel_dyn
->add_symbolless_global_addend(gsym
,
2238 elfcpp::R_386_IRELATIVE
,
2241 reloc
.get_r_offset());
2243 else if (r_type
== elfcpp::R_386_32
2244 && gsym
->can_use_relative_reloc(false))
2246 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2247 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
2248 output_section
, object
,
2249 data_shndx
, reloc
.get_r_offset());
2253 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2254 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
2255 data_shndx
, reloc
.get_r_offset());
2261 case elfcpp::R_386_PC32
:
2262 case elfcpp::R_386_PC16
:
2263 case elfcpp::R_386_PC8
:
2265 // Make a PLT entry if necessary.
2266 if (gsym
->needs_plt_entry())
2268 // These relocations are used for function calls only in
2269 // non-PIC code. For a 32-bit relocation in a shared library,
2270 // we'll need a text relocation anyway, so we can skip the
2271 // PLT entry and let the dynamic linker bind the call directly
2272 // to the target. For smaller relocations, we should use a
2273 // PLT entry to ensure that the call can reach.
2274 if (!parameters
->options().shared()
2275 || r_type
!= elfcpp::R_386_PC32
)
2276 target
->make_plt_entry(symtab
, layout
, gsym
);
2278 // Make a dynamic relocation if necessary.
2279 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
2281 if (parameters
->options().output_is_executable()
2282 && gsym
->may_need_copy_reloc())
2284 target
->copy_reloc(symtab
, layout
, object
,
2285 data_shndx
, output_section
, gsym
, reloc
);
2289 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2290 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
2291 data_shndx
, reloc
.get_r_offset());
2297 case elfcpp::R_386_GOT32
:
2298 case elfcpp::R_386_GOT32X
:
2300 // The symbol requires a GOT section.
2301 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
2303 // If we convert this from
2304 // mov foo@GOT(%reg), %reg
2306 // lea foo@GOTOFF(%reg), %reg
2307 // in Relocate::relocate, then there is nothing to do here.
2308 if (reloc
.get_r_offset() >= 2
2309 && Target_i386::can_convert_mov_to_lea(gsym
))
2311 section_size_type stype
;
2312 const unsigned char* view
= object
->section_contents(data_shndx
,
2314 if (view
[reloc
.get_r_offset() - 2] == 0x8b)
2318 if (gsym
->final_value_is_known())
2320 // For a STT_GNU_IFUNC symbol we want the PLT address.
2321 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
)
2322 got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
2324 got
->add_global(gsym
, GOT_TYPE_STANDARD
);
2328 // If this symbol is not fully resolved, we need to add a
2329 // GOT entry with a dynamic relocation.
2330 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2332 // Use a GLOB_DAT rather than a RELATIVE reloc if:
2334 // 1) The symbol may be defined in some other module.
2336 // 2) We are building a shared library and this is a
2337 // protected symbol; using GLOB_DAT means that the dynamic
2338 // linker can use the address of the PLT in the main
2339 // executable when appropriate so that function address
2340 // comparisons work.
2342 // 3) This is a STT_GNU_IFUNC symbol in position dependent
2343 // code, again so that function address comparisons work.
2344 if (gsym
->is_from_dynobj()
2345 || gsym
->is_undefined()
2346 || gsym
->is_preemptible()
2347 || (gsym
->visibility() == elfcpp::STV_PROTECTED
2348 && parameters
->options().shared())
2349 || (gsym
->type() == elfcpp::STT_GNU_IFUNC
2350 && parameters
->options().output_is_position_independent()))
2351 got
->add_global_with_rel(gsym
, GOT_TYPE_STANDARD
,
2352 rel_dyn
, elfcpp::R_386_GLOB_DAT
);
2355 // For a STT_GNU_IFUNC symbol we want to write the PLT
2356 // offset into the GOT, so that function pointer
2357 // comparisons work correctly.
2359 if (gsym
->type() != elfcpp::STT_GNU_IFUNC
)
2360 is_new
= got
->add_global(gsym
, GOT_TYPE_STANDARD
);
2363 is_new
= got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
2364 // Tell the dynamic linker to use the PLT address
2365 // when resolving relocations.
2366 if (gsym
->is_from_dynobj()
2367 && !parameters
->options().shared())
2368 gsym
->set_needs_dynsym_value();
2372 unsigned int got_off
= gsym
->got_offset(GOT_TYPE_STANDARD
);
2373 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
2381 case elfcpp::R_386_PLT32
:
2382 // If the symbol is fully resolved, this is just a PC32 reloc.
2383 // Otherwise we need a PLT entry.
2384 if (gsym
->final_value_is_known())
2386 // If building a shared library, we can also skip the PLT entry
2387 // if the symbol is defined in the output file and is protected
2389 if (gsym
->is_defined()
2390 && !gsym
->is_from_dynobj()
2391 && !gsym
->is_preemptible())
2393 target
->make_plt_entry(symtab
, layout
, gsym
);
2396 case elfcpp::R_386_GOTOFF
:
2397 // A GOT-relative reference must resolve locally.
2398 if (!gsym
->is_defined())
2399 gold_error(_("%s: relocation R_386_GOTOFF against undefined symbol %s"
2400 " cannot be used when making a shared object"),
2401 object
->name().c_str(), gsym
->name());
2402 else if (gsym
->is_from_dynobj())
2403 gold_error(_("%s: relocation R_386_GOTOFF against external symbol %s"
2404 " cannot be used when making a shared object"),
2405 object
->name().c_str(), gsym
->name());
2406 else if (gsym
->is_preemptible())
2407 gold_error(_("%s: relocation R_386_GOTOFF against preemptible symbol %s"
2408 " cannot be used when making a shared object"),
2409 object
->name().c_str(), gsym
->name());
2410 // We need a GOT section.
2411 target
->got_section(symtab
, layout
);
2414 case elfcpp::R_386_GOTPC
:
2415 // We need a GOT section.
2416 target
->got_section(symtab
, layout
);
2419 // These are relocations which should only be seen by the
2420 // dynamic linker, and should never be seen here.
2421 case elfcpp::R_386_COPY
:
2422 case elfcpp::R_386_GLOB_DAT
:
2423 case elfcpp::R_386_JUMP_SLOT
:
2424 case elfcpp::R_386_RELATIVE
:
2425 case elfcpp::R_386_IRELATIVE
:
2426 case elfcpp::R_386_TLS_TPOFF
:
2427 case elfcpp::R_386_TLS_DTPMOD32
:
2428 case elfcpp::R_386_TLS_DTPOFF32
:
2429 case elfcpp::R_386_TLS_TPOFF32
:
2430 case elfcpp::R_386_TLS_DESC
:
2431 gold_error(_("%s: unexpected reloc %u in object file"),
2432 object
->name().c_str(), r_type
);
2435 // These are initial tls relocs, which are expected when
2437 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2438 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2439 case elfcpp::R_386_TLS_DESC_CALL
:
2440 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2441 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2442 case elfcpp::R_386_TLS_IE
: // Initial-exec
2443 case elfcpp::R_386_TLS_IE_32
:
2444 case elfcpp::R_386_TLS_GOTIE
:
2445 case elfcpp::R_386_TLS_LE
: // Local-exec
2446 case elfcpp::R_386_TLS_LE_32
:
2448 const bool is_final
= gsym
->final_value_is_known();
2449 const tls::Tls_optimization optimized_type
2450 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
2453 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2454 if (optimized_type
== tls::TLSOPT_NONE
)
2456 // Create a pair of GOT entries for the module index and
2457 // dtv-relative offset.
2458 Output_data_got
<32, false>* got
2459 = target
->got_section(symtab
, layout
);
2460 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_PAIR
,
2461 target
->rel_dyn_section(layout
),
2462 elfcpp::R_386_TLS_DTPMOD32
,
2463 elfcpp::R_386_TLS_DTPOFF32
);
2465 else if (optimized_type
== tls::TLSOPT_TO_IE
)
2467 // Create a GOT entry for the tp-relative offset.
2468 Output_data_got
<32, false>* got
2469 = target
->got_section(symtab
, layout
);
2470 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
2471 target
->rel_dyn_section(layout
),
2472 elfcpp::R_386_TLS_TPOFF
);
2474 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2475 unsupported_reloc_global(object
, r_type
, gsym
);
2478 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (~oliva url)
2479 target
->define_tls_base_symbol(symtab
, layout
);
2480 if (optimized_type
== tls::TLSOPT_NONE
)
2482 // Create a double GOT entry with an R_386_TLS_DESC
2483 // reloc. The R_386_TLS_DESC reloc is resolved
2484 // lazily, so the GOT entry needs to be in an area in
2485 // .got.plt, not .got. Call got_section to make sure
2486 // the section has been created.
2487 target
->got_section(symtab
, layout
);
2488 Output_data_got
<32, false>* got
= target
->got_tlsdesc_section();
2489 Reloc_section
* rt
= target
->rel_tls_desc_section(layout
);
2490 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_DESC
, rt
,
2491 elfcpp::R_386_TLS_DESC
, 0);
2493 else if (optimized_type
== tls::TLSOPT_TO_IE
)
2495 // Create a GOT entry for the tp-relative offset.
2496 Output_data_got
<32, false>* got
2497 = target
->got_section(symtab
, layout
);
2498 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
2499 target
->rel_dyn_section(layout
),
2500 elfcpp::R_386_TLS_TPOFF
);
2502 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2503 unsupported_reloc_global(object
, r_type
, gsym
);
2506 case elfcpp::R_386_TLS_DESC_CALL
:
2509 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2510 if (optimized_type
== tls::TLSOPT_NONE
)
2512 // Create a GOT entry for the module index.
2513 target
->got_mod_index_entry(symtab
, layout
, object
);
2515 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2516 unsupported_reloc_global(object
, r_type
, gsym
);
2519 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2522 case elfcpp::R_386_TLS_IE
: // Initial-exec
2523 case elfcpp::R_386_TLS_IE_32
:
2524 case elfcpp::R_386_TLS_GOTIE
:
2525 layout
->set_has_static_tls();
2526 if (optimized_type
== tls::TLSOPT_NONE
)
2528 // For the R_386_TLS_IE relocation, we need to create a
2529 // dynamic relocation when building a shared library.
2530 if (r_type
== elfcpp::R_386_TLS_IE
2531 && parameters
->options().shared())
2533 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2534 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
2535 output_section
, object
,
2537 reloc
.get_r_offset());
2539 // Create a GOT entry for the tp-relative offset.
2540 Output_data_got
<32, false>* got
2541 = target
->got_section(symtab
, layout
);
2542 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2543 ? elfcpp::R_386_TLS_TPOFF32
2544 : elfcpp::R_386_TLS_TPOFF
);
2545 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2546 ? GOT_TYPE_TLS_OFFSET
2547 : GOT_TYPE_TLS_NOFFSET
);
2548 got
->add_global_with_rel(gsym
, got_type
,
2549 target
->rel_dyn_section(layout
),
2552 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2553 unsupported_reloc_global(object
, r_type
, gsym
);
2556 case elfcpp::R_386_TLS_LE
: // Local-exec
2557 case elfcpp::R_386_TLS_LE_32
:
2558 layout
->set_has_static_tls();
2559 if (parameters
->options().shared())
2561 // We need to create a dynamic relocation.
2562 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
2563 ? elfcpp::R_386_TLS_TPOFF32
2564 : elfcpp::R_386_TLS_TPOFF
);
2565 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2566 rel_dyn
->add_global(gsym
, dyn_r_type
, output_section
, object
,
2567 data_shndx
, reloc
.get_r_offset());
2577 case elfcpp::R_386_32PLT
:
2578 case elfcpp::R_386_TLS_GD_32
:
2579 case elfcpp::R_386_TLS_GD_PUSH
:
2580 case elfcpp::R_386_TLS_GD_CALL
:
2581 case elfcpp::R_386_TLS_GD_POP
:
2582 case elfcpp::R_386_TLS_LDM_32
:
2583 case elfcpp::R_386_TLS_LDM_PUSH
:
2584 case elfcpp::R_386_TLS_LDM_CALL
:
2585 case elfcpp::R_386_TLS_LDM_POP
:
2586 case elfcpp::R_386_USED_BY_INTEL_200
:
2588 unsupported_reloc_global(object
, r_type
, gsym
);
2593 // Process relocations for gc.
2596 Target_i386::gc_process_relocs(Symbol_table
* symtab
,
2598 Sized_relobj_file
<32, false>* object
,
2599 unsigned int data_shndx
,
2601 const unsigned char* prelocs
,
2603 Output_section
* output_section
,
2604 bool needs_special_offset_handling
,
2605 size_t local_symbol_count
,
2606 const unsigned char* plocal_symbols
)
2608 gold::gc_process_relocs
<32, false, Target_i386
, Scan
, Classify_reloc
>(
2617 needs_special_offset_handling
,
2622 // Scan relocations for a section.
2625 Target_i386::scan_relocs(Symbol_table
* symtab
,
2627 Sized_relobj_file
<32, false>* object
,
2628 unsigned int data_shndx
,
2629 unsigned int sh_type
,
2630 const unsigned char* prelocs
,
2632 Output_section
* output_section
,
2633 bool needs_special_offset_handling
,
2634 size_t local_symbol_count
,
2635 const unsigned char* plocal_symbols
)
2637 if (sh_type
== elfcpp::SHT_RELA
)
2639 gold_error(_("%s: unsupported RELA reloc section"),
2640 object
->name().c_str());
2644 gold::scan_relocs
<32, false, Target_i386
, Scan
, Classify_reloc
>(
2653 needs_special_offset_handling
,
2658 // Finalize the sections.
2661 Target_i386::do_finalize_sections(
2663 const Input_objects
*,
2664 Symbol_table
* symtab
)
2666 const Reloc_section
* rel_plt
= (this->plt_
== NULL
2668 : this->plt_
->rel_plt());
2669 layout
->add_target_dynamic_tags(true, this->got_plt_
, rel_plt
,
2670 this->rel_dyn_
, true, false);
2672 // Emit any relocs we saved in an attempt to avoid generating COPY
2674 if (this->copy_relocs_
.any_saved_relocs())
2675 this->copy_relocs_
.emit(this->rel_dyn_section(layout
));
2677 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
2678 // the .got.plt section.
2679 Symbol
* sym
= this->global_offset_table_
;
2682 uint32_t data_size
= this->got_plt_
->current_data_size();
2683 symtab
->get_sized_symbol
<32>(sym
)->set_symsize(data_size
);
2686 if (parameters
->doing_static_link()
2687 && (this->plt_
== NULL
|| !this->plt_
->has_irelative_section()))
2689 // If linking statically, make sure that the __rel_iplt symbols
2690 // were defined if necessary, even if we didn't create a PLT.
2691 static const Define_symbol_in_segment syms
[] =
2694 "__rel_iplt_start", // name
2695 elfcpp::PT_LOAD
, // segment_type
2696 elfcpp::PF_W
, // segment_flags_set
2697 elfcpp::PF(0), // segment_flags_clear
2700 elfcpp::STT_NOTYPE
, // type
2701 elfcpp::STB_GLOBAL
, // binding
2702 elfcpp::STV_HIDDEN
, // visibility
2704 Symbol::SEGMENT_START
, // offset_from_base
2708 "__rel_iplt_end", // name
2709 elfcpp::PT_LOAD
, // segment_type
2710 elfcpp::PF_W
, // segment_flags_set
2711 elfcpp::PF(0), // segment_flags_clear
2714 elfcpp::STT_NOTYPE
, // type
2715 elfcpp::STB_GLOBAL
, // binding
2716 elfcpp::STV_HIDDEN
, // visibility
2718 Symbol::SEGMENT_START
, // offset_from_base
2723 symtab
->define_symbols(layout
, 2, syms
,
2724 layout
->script_options()->saw_sections_clause());
2728 // Return whether a direct absolute static relocation needs to be applied.
2729 // In cases where Scan::local() or Scan::global() has created
2730 // a dynamic relocation other than R_386_RELATIVE, the addend
2731 // of the relocation is carried in the data, and we must not
2732 // apply the static relocation.
2735 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
2736 unsigned int r_type
,
2738 Output_section
* output_section
)
2740 // If the output section is not allocated, then we didn't call
2741 // scan_relocs, we didn't create a dynamic reloc, and we must apply
2743 if ((output_section
->flags() & elfcpp::SHF_ALLOC
) == 0)
2746 int ref_flags
= Scan::get_reference_flags(r_type
);
2748 // For local symbols, we will have created a non-RELATIVE dynamic
2749 // relocation only if (a) the output is position independent,
2750 // (b) the relocation is absolute (not pc- or segment-relative), and
2751 // (c) the relocation is not 32 bits wide.
2753 return !(parameters
->options().output_is_position_independent()
2754 && (ref_flags
& Symbol::ABSOLUTE_REF
)
2757 // For global symbols, we use the same helper routines used in the
2758 // scan pass. If we did not create a dynamic relocation, or if we
2759 // created a RELATIVE dynamic relocation, we should apply the static
2761 bool has_dyn
= gsym
->needs_dynamic_reloc(ref_flags
);
2762 bool is_rel
= (ref_flags
& Symbol::ABSOLUTE_REF
)
2763 && gsym
->can_use_relative_reloc(ref_flags
2764 & Symbol::FUNCTION_CALL
);
2765 return !has_dyn
|| is_rel
;
2768 // Perform a relocation.
2771 Target_i386::Relocate::relocate(const Relocate_info
<32, false>* relinfo
,
2773 Target_i386
* target
,
2774 Output_section
* output_section
,
2776 const unsigned char* preloc
,
2777 const Sized_symbol
<32>* gsym
,
2778 const Symbol_value
<32>* psymval
,
2779 unsigned char* view
,
2780 elfcpp::Elf_types
<32>::Elf_Addr address
,
2781 section_size_type view_size
)
2783 const elfcpp::Rel
<32, false> rel(preloc
);
2784 unsigned int r_type
= elfcpp::elf_r_type
<32>(rel
.get_r_info());
2786 if (this->skip_call_tls_get_addr_
)
2788 if ((r_type
!= elfcpp::R_386_PLT32
2789 && r_type
!= elfcpp::R_386_PC32
)
2791 || strcmp(gsym
->name(), "___tls_get_addr") != 0)
2792 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2793 _("missing expected TLS relocation"));
2796 this->skip_call_tls_get_addr_
= false;
2804 const Sized_relobj_file
<32, false>* object
= relinfo
->object
;
2806 // Pick the value to use for symbols defined in shared objects.
2807 Symbol_value
<32> symval
;
2809 && gsym
->type() == elfcpp::STT_GNU_IFUNC
2810 && r_type
== elfcpp::R_386_32
2811 && gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
))
2812 && gsym
->can_use_relative_reloc(false)
2813 && !gsym
->is_from_dynobj()
2814 && !gsym
->is_undefined()
2815 && !gsym
->is_preemptible())
2817 // In this case we are generating a R_386_IRELATIVE reloc. We
2818 // want to use the real value of the symbol, not the PLT offset.
2820 else if (gsym
!= NULL
2821 && gsym
->use_plt_offset(Scan::get_reference_flags(r_type
)))
2823 symval
.set_output_value(target
->plt_address_for_global(gsym
));
2826 else if (gsym
== NULL
&& psymval
->is_ifunc_symbol())
2828 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2829 if (object
->local_has_plt_offset(r_sym
))
2831 symval
.set_output_value(target
->plt_address_for_local(object
, r_sym
));
2840 case elfcpp::R_386_NONE
:
2841 case elfcpp::R_386_GNU_VTINHERIT
:
2842 case elfcpp::R_386_GNU_VTENTRY
:
2845 case elfcpp::R_386_32
:
2846 if (should_apply_static_reloc(gsym
, r_type
, true, output_section
))
2847 Relocate_functions
<32, false>::rel32(view
, object
, psymval
);
2850 case elfcpp::R_386_PC32
:
2851 if (should_apply_static_reloc(gsym
, r_type
, true, output_section
))
2852 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
2855 case elfcpp::R_386_16
:
2856 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2857 Relocate_functions
<32, false>::rel16(view
, object
, psymval
);
2860 case elfcpp::R_386_PC16
:
2861 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2862 Relocate_functions
<32, false>::pcrel16(view
, object
, psymval
, address
);
2865 case elfcpp::R_386_8
:
2866 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2867 Relocate_functions
<32, false>::rel8(view
, object
, psymval
);
2870 case elfcpp::R_386_PC8
:
2871 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2872 Relocate_functions
<32, false>::pcrel8(view
, object
, psymval
, address
);
2875 case elfcpp::R_386_PLT32
:
2876 gold_assert(gsym
== NULL
2877 || gsym
->has_plt_offset()
2878 || gsym
->final_value_is_known()
2879 || (gsym
->is_defined()
2880 && !gsym
->is_from_dynobj()
2881 && !gsym
->is_preemptible()));
2882 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
2885 case elfcpp::R_386_GOT32
:
2886 case elfcpp::R_386_GOT32X
:
2887 baseless
= (view
[-1] & 0xc7) == 0x5;
2888 // R_386_GOT32 and R_386_GOT32X don't work without base register
2889 // when generating a position-independent output file.
2891 && parameters
->options().output_is_position_independent())
2894 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2895 _("unexpected reloc %u against global symbol %s without base register in object file when generating a position-independent output file"),
2896 r_type
, gsym
->demangled_name().c_str());
2898 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2899 _("unexpected reloc %u against local symbol without base register in object file when generating a position-independent output file"),
2904 // mov foo@GOT(%reg), %reg
2906 // lea foo@GOTOFF(%reg), %reg
2908 if (rel
.get_r_offset() >= 2
2910 && ((gsym
== NULL
&& !psymval
->is_ifunc_symbol())
2912 && Target_i386::can_convert_mov_to_lea(gsym
))))
2915 elfcpp::Elf_types
<32>::Elf_Addr value
;
2916 value
= psymval
->value(object
, 0);
2917 // Don't subtract the .got.plt section address for baseless
2920 value
-= target
->got_plt_section()->address();
2921 Relocate_functions
<32, false>::rel32(view
, value
);
2925 // The GOT pointer points to the end of the GOT section.
2926 // We need to subtract the size of the GOT section to get
2927 // the actual offset to use in the relocation.
2928 unsigned int got_offset
= 0;
2931 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
2932 got_offset
= (gsym
->got_offset(GOT_TYPE_STANDARD
)
2933 - target
->got_size());
2937 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2938 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
2939 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
2940 - target
->got_size());
2942 // Add the .got.plt section address for baseless addressing.
2944 got_offset
+= target
->got_plt_section()->address();
2945 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2949 case elfcpp::R_386_GOTOFF
:
2951 elfcpp::Elf_types
<32>::Elf_Addr value
;
2952 value
= (psymval
->value(object
, 0)
2953 - target
->got_plt_section()->address());
2954 Relocate_functions
<32, false>::rel32(view
, value
);
2958 case elfcpp::R_386_GOTPC
:
2960 elfcpp::Elf_types
<32>::Elf_Addr value
;
2961 value
= target
->got_plt_section()->address();
2962 Relocate_functions
<32, false>::pcrel32(view
, value
, address
);
2966 case elfcpp::R_386_COPY
:
2967 case elfcpp::R_386_GLOB_DAT
:
2968 case elfcpp::R_386_JUMP_SLOT
:
2969 case elfcpp::R_386_RELATIVE
:
2970 case elfcpp::R_386_IRELATIVE
:
2971 // These are outstanding tls relocs, which are unexpected when
2973 case elfcpp::R_386_TLS_TPOFF
:
2974 case elfcpp::R_386_TLS_DTPMOD32
:
2975 case elfcpp::R_386_TLS_DTPOFF32
:
2976 case elfcpp::R_386_TLS_TPOFF32
:
2977 case elfcpp::R_386_TLS_DESC
:
2978 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2979 _("unexpected reloc %u in object file"),
2983 // These are initial tls relocs, which are expected when
2985 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2986 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2987 case elfcpp::R_386_TLS_DESC_CALL
:
2988 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2989 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2990 case elfcpp::R_386_TLS_IE
: // Initial-exec
2991 case elfcpp::R_386_TLS_IE_32
:
2992 case elfcpp::R_386_TLS_GOTIE
:
2993 case elfcpp::R_386_TLS_LE
: // Local-exec
2994 case elfcpp::R_386_TLS_LE_32
:
2995 this->relocate_tls(relinfo
, target
, relnum
, rel
, r_type
, gsym
, psymval
,
2996 view
, address
, view_size
);
2999 case elfcpp::R_386_32PLT
:
3000 case elfcpp::R_386_TLS_GD_32
:
3001 case elfcpp::R_386_TLS_GD_PUSH
:
3002 case elfcpp::R_386_TLS_GD_CALL
:
3003 case elfcpp::R_386_TLS_GD_POP
:
3004 case elfcpp::R_386_TLS_LDM_32
:
3005 case elfcpp::R_386_TLS_LDM_PUSH
:
3006 case elfcpp::R_386_TLS_LDM_CALL
:
3007 case elfcpp::R_386_TLS_LDM_POP
:
3008 case elfcpp::R_386_USED_BY_INTEL_200
:
3010 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3011 _("unsupported reloc %u"),
3019 // Perform a TLS relocation.
3022 Target_i386::Relocate::relocate_tls(const Relocate_info
<32, false>* relinfo
,
3023 Target_i386
* target
,
3025 const elfcpp::Rel
<32, false>& rel
,
3026 unsigned int r_type
,
3027 const Sized_symbol
<32>* gsym
,
3028 const Symbol_value
<32>* psymval
,
3029 unsigned char* view
,
3030 elfcpp::Elf_types
<32>::Elf_Addr
,
3031 section_size_type view_size
)
3033 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
3035 const Sized_relobj_file
<32, false>* object
= relinfo
->object
;
3037 elfcpp::Elf_types
<32>::Elf_Addr value
= psymval
->value(object
, 0);
3039 const bool is_final
= (gsym
== NULL
3040 ? !parameters
->options().shared()
3041 : gsym
->final_value_is_known());
3042 const tls::Tls_optimization optimized_type
3043 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
3046 case elfcpp::R_386_TLS_GD
: // Global-dynamic
3047 if (optimized_type
== tls::TLSOPT_TO_LE
)
3049 if (tls_segment
== NULL
)
3051 gold_assert(parameters
->errors()->error_count() > 0
3052 || issue_undefined_symbol_error(gsym
));
3055 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
3056 rel
, r_type
, value
, view
,
3062 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
3063 ? GOT_TYPE_TLS_NOFFSET
3064 : GOT_TYPE_TLS_PAIR
);
3065 unsigned int got_offset
;
3068 gold_assert(gsym
->has_got_offset(got_type
));
3069 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
3073 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
3074 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
3075 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
3076 - target
->got_size());
3078 if (optimized_type
== tls::TLSOPT_TO_IE
)
3080 this->tls_gd_to_ie(relinfo
, relnum
, rel
, r_type
,
3081 got_offset
, view
, view_size
);
3084 else if (optimized_type
== tls::TLSOPT_NONE
)
3086 // Relocate the field with the offset of the pair of GOT
3088 Relocate_functions
<32, false>::rel32(view
, got_offset
);
3092 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3093 _("unsupported reloc %u"),
3097 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
3098 case elfcpp::R_386_TLS_DESC_CALL
:
3099 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
3100 if (optimized_type
== tls::TLSOPT_TO_LE
)
3102 if (tls_segment
== NULL
)
3104 gold_assert(parameters
->errors()->error_count() > 0
3105 || issue_undefined_symbol_error(gsym
));
3108 this->tls_desc_gd_to_le(relinfo
, relnum
, tls_segment
,
3109 rel
, r_type
, value
, view
,
3115 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
3116 ? GOT_TYPE_TLS_NOFFSET
3117 : GOT_TYPE_TLS_DESC
);
3118 unsigned int got_offset
= 0;
3119 if (r_type
== elfcpp::R_386_TLS_GOTDESC
3120 && optimized_type
== tls::TLSOPT_NONE
)
3122 // We created GOT entries in the .got.tlsdesc portion of
3123 // the .got.plt section, but the offset stored in the
3124 // symbol is the offset within .got.tlsdesc.
3125 got_offset
= (target
->got_size()
3126 + target
->got_plt_section()->data_size());
3130 gold_assert(gsym
->has_got_offset(got_type
));
3131 got_offset
+= gsym
->got_offset(got_type
) - target
->got_size();
3135 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
3136 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
3137 got_offset
+= (object
->local_got_offset(r_sym
, got_type
)
3138 - target
->got_size());
3140 if (optimized_type
== tls::TLSOPT_TO_IE
)
3142 this->tls_desc_gd_to_ie(relinfo
, relnum
, rel
, r_type
,
3143 got_offset
, view
, view_size
);
3146 else if (optimized_type
== tls::TLSOPT_NONE
)
3148 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
3150 // Relocate the field with the offset of the pair of GOT
3152 Relocate_functions
<32, false>::rel32(view
, got_offset
);
3157 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3158 _("unsupported reloc %u"),
3162 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
3163 if (this->local_dynamic_type_
== LOCAL_DYNAMIC_SUN
)
3165 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3166 _("both SUN and GNU model "
3167 "TLS relocations"));
3170 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
3171 if (optimized_type
== tls::TLSOPT_TO_LE
)
3173 if (tls_segment
== NULL
)
3175 gold_assert(parameters
->errors()->error_count() > 0
3176 || issue_undefined_symbol_error(gsym
));
3179 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rel
, r_type
,
3180 value
, view
, view_size
);
3183 else if (optimized_type
== tls::TLSOPT_NONE
)
3185 // Relocate the field with the offset of the GOT entry for
3186 // the module index.
3187 unsigned int got_offset
;
3188 got_offset
= (target
->got_mod_index_entry(NULL
, NULL
, NULL
)
3189 - target
->got_size());
3190 Relocate_functions
<32, false>::rel32(view
, got_offset
);
3193 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3194 _("unsupported reloc %u"),
3198 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
3199 if (optimized_type
== tls::TLSOPT_TO_LE
)
3201 // This reloc can appear in debugging sections, in which
3202 // case we must not convert to local-exec. We decide what
3203 // to do based on whether the section is marked as
3204 // containing executable code. That is what the GNU linker
3206 elfcpp::Shdr
<32, false> shdr(relinfo
->data_shdr
);
3207 if ((shdr
.get_sh_flags() & elfcpp::SHF_EXECINSTR
) != 0)
3209 if (tls_segment
== NULL
)
3211 gold_assert(parameters
->errors()->error_count() > 0
3212 || issue_undefined_symbol_error(gsym
));
3215 value
-= tls_segment
->memsz();
3218 Relocate_functions
<32, false>::rel32(view
, value
);
3221 case elfcpp::R_386_TLS_IE
: // Initial-exec
3222 case elfcpp::R_386_TLS_GOTIE
:
3223 case elfcpp::R_386_TLS_IE_32
:
3224 if (optimized_type
== tls::TLSOPT_TO_LE
)
3226 if (tls_segment
== NULL
)
3228 gold_assert(parameters
->errors()->error_count() > 0
3229 || issue_undefined_symbol_error(gsym
));
3232 Target_i386::Relocate::tls_ie_to_le(relinfo
, relnum
, tls_segment
,
3233 rel
, r_type
, value
, view
,
3237 else if (optimized_type
== tls::TLSOPT_NONE
)
3239 // Relocate the field with the offset of the GOT entry for
3240 // the tp-relative offset of the symbol.
3241 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
3242 ? GOT_TYPE_TLS_OFFSET
3243 : GOT_TYPE_TLS_NOFFSET
);
3244 unsigned int got_offset
;
3247 gold_assert(gsym
->has_got_offset(got_type
));
3248 got_offset
= gsym
->got_offset(got_type
);
3252 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
3253 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
3254 got_offset
= object
->local_got_offset(r_sym
, got_type
);
3256 // For the R_386_TLS_IE relocation, we need to apply the
3257 // absolute address of the GOT entry.
3258 if (r_type
== elfcpp::R_386_TLS_IE
)
3259 got_offset
+= target
->got_plt_section()->address();
3260 // All GOT offsets are relative to the end of the GOT.
3261 got_offset
-= target
->got_size();
3262 Relocate_functions
<32, false>::rel32(view
, got_offset
);
3265 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3266 _("unsupported reloc %u"),
3270 case elfcpp::R_386_TLS_LE
: // Local-exec
3271 // If we're creating a shared library, a dynamic relocation will
3272 // have been created for this location, so do not apply it now.
3273 if (!parameters
->options().shared())
3275 if (tls_segment
== NULL
)
3277 gold_assert(parameters
->errors()->error_count() > 0
3278 || issue_undefined_symbol_error(gsym
));
3281 value
-= tls_segment
->memsz();
3282 Relocate_functions
<32, false>::rel32(view
, value
);
3286 case elfcpp::R_386_TLS_LE_32
:
3287 // If we're creating a shared library, a dynamic relocation will
3288 // have been created for this location, so do not apply it now.
3289 if (!parameters
->options().shared())
3291 if (tls_segment
== NULL
)
3293 gold_assert(parameters
->errors()->error_count() > 0
3294 || issue_undefined_symbol_error(gsym
));
3297 value
= tls_segment
->memsz() - value
;
3298 Relocate_functions
<32, false>::rel32(view
, value
);
3304 // Do a relocation in which we convert a TLS General-Dynamic to a
3308 Target_i386::Relocate::tls_gd_to_le(const Relocate_info
<32, false>* relinfo
,
3310 Output_segment
* tls_segment
,
3311 const elfcpp::Rel
<32, false>& rel
,
3313 elfcpp::Elf_types
<32>::Elf_Addr value
,
3314 unsigned char* view
,
3315 section_size_type view_size
)
3317 // leal foo(,%reg,1),%eax; call ___tls_get_addr
3318 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
3319 // leal foo(%reg),%eax; call ___tls_get_addr
3320 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
3322 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3323 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
3325 unsigned char op1
= view
[-1];
3326 unsigned char op2
= view
[-2];
3328 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3329 op2
== 0x8d || op2
== 0x04);
3330 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
3336 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
3337 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
3338 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3339 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
3340 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3344 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3345 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
3346 if (rel
.get_r_offset() + 9 < view_size
3349 // There is a trailing nop. Use the size byte subl.
3350 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3355 // Use the five byte subl.
3356 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
3360 value
= tls_segment
->memsz() - value
;
3361 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
3363 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3365 this->skip_call_tls_get_addr_
= true;
3368 // Do a relocation in which we convert a TLS General-Dynamic to an
3372 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info
<32, false>* relinfo
,
3374 const elfcpp::Rel
<32, false>& rel
,
3376 elfcpp::Elf_types
<32>::Elf_Addr value
,
3377 unsigned char* view
,
3378 section_size_type view_size
)
3380 // leal foo(,%ebx,1),%eax; call ___tls_get_addr
3381 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
3382 // leal foo(%ebx),%eax; call ___tls_get_addr; nop
3383 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
3385 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3386 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
3388 unsigned char op1
= view
[-1];
3389 unsigned char op2
= view
[-2];
3391 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3392 op2
== 0x8d || op2
== 0x04);
3393 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
3399 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
3400 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
3401 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3402 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
3407 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 10);
3408 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3409 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
3410 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[9] == 0x90);
3414 memcpy(view
+ roff
- 8, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
3415 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
3417 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3419 this->skip_call_tls_get_addr_
= true;
3422 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3423 // General-Dynamic to a Local-Exec.
3426 Target_i386::Relocate::tls_desc_gd_to_le(
3427 const Relocate_info
<32, false>* relinfo
,
3429 Output_segment
* tls_segment
,
3430 const elfcpp::Rel
<32, false>& rel
,
3431 unsigned int r_type
,
3432 elfcpp::Elf_types
<32>::Elf_Addr value
,
3433 unsigned char* view
,
3434 section_size_type view_size
)
3436 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
3438 // leal foo@TLSDESC(%ebx), %eax
3439 // ==> leal foo@NTPOFF, %eax
3440 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3441 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3442 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3443 view
[-2] == 0x8d && view
[-1] == 0x83);
3445 value
-= tls_segment
->memsz();
3446 Relocate_functions
<32, false>::rel32(view
, value
);
3450 // call *foo@TLSCALL(%eax)
3452 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
3453 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
3454 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3455 view
[0] == 0xff && view
[1] == 0x10);
3461 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3462 // General-Dynamic to an Initial-Exec.
3465 Target_i386::Relocate::tls_desc_gd_to_ie(
3466 const Relocate_info
<32, false>* relinfo
,
3468 const elfcpp::Rel
<32, false>& rel
,
3469 unsigned int r_type
,
3470 elfcpp::Elf_types
<32>::Elf_Addr value
,
3471 unsigned char* view
,
3472 section_size_type view_size
)
3474 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
3476 // leal foo@TLSDESC(%ebx), %eax
3477 // ==> movl foo@GOTNTPOFF(%ebx), %eax
3478 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3479 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3480 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3481 view
[-2] == 0x8d && view
[-1] == 0x83);
3483 Relocate_functions
<32, false>::rel32(view
, value
);
3487 // call *foo@TLSCALL(%eax)
3489 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
3490 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
3491 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3492 view
[0] == 0xff && view
[1] == 0x10);
3498 // Do a relocation in which we convert a TLS Local-Dynamic to a
3502 Target_i386::Relocate::tls_ld_to_le(const Relocate_info
<32, false>* relinfo
,
3505 const elfcpp::Rel
<32, false>& rel
,
3507 elfcpp::Elf_types
<32>::Elf_Addr
,
3508 unsigned char* view
,
3509 section_size_type view_size
)
3511 // leal foo(%reg), %eax; call ___tls_get_addr
3512 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
3514 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3515 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
3517 // FIXME: Does this test really always pass?
3518 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3519 view
[-2] == 0x8d && view
[-1] == 0x83);
3521 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
3523 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
3525 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3527 this->skip_call_tls_get_addr_
= true;
3530 // Do a relocation in which we convert a TLS Initial-Exec to a
3534 Target_i386::Relocate::tls_ie_to_le(const Relocate_info
<32, false>* relinfo
,
3536 Output_segment
* tls_segment
,
3537 const elfcpp::Rel
<32, false>& rel
,
3538 unsigned int r_type
,
3539 elfcpp::Elf_types
<32>::Elf_Addr value
,
3540 unsigned char* view
,
3541 section_size_type view_size
)
3543 // We have to actually change the instructions, which means that we
3544 // need to examine the opcodes to figure out which instruction we
3546 if (r_type
== elfcpp::R_386_TLS_IE
)
3548 // movl %gs:XX,%eax ==> movl $YY,%eax
3549 // movl %gs:XX,%reg ==> movl $YY,%reg
3550 // addl %gs:XX,%reg ==> addl $YY,%reg
3551 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -1);
3552 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3554 unsigned char op1
= view
[-1];
3557 // movl XX,%eax ==> movl $YY,%eax
3562 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3564 unsigned char op2
= view
[-2];
3567 // movl XX,%reg ==> movl $YY,%reg
3568 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3569 (op1
& 0xc7) == 0x05);
3571 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3573 else if (op2
== 0x03)
3575 // addl XX,%reg ==> addl $YY,%reg
3576 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3577 (op1
& 0xc7) == 0x05);
3579 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3582 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
3587 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
3588 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
3589 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
3590 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3591 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3593 unsigned char op1
= view
[-1];
3594 unsigned char op2
= view
[-2];
3595 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3596 (op1
& 0xc0) == 0x80 && (op1
& 7) != 4);
3599 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
3601 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3603 else if (op2
== 0x2b)
3605 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
3607 view
[-1] = 0xe8 | ((op1
>> 3) & 7);
3609 else if (op2
== 0x03)
3611 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
3613 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3616 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
3619 value
= tls_segment
->memsz() - value
;
3620 if (r_type
== elfcpp::R_386_TLS_IE
|| r_type
== elfcpp::R_386_TLS_GOTIE
)
3623 Relocate_functions
<32, false>::rel32(view
, value
);
3626 // Relocate section data.
3629 Target_i386::relocate_section(const Relocate_info
<32, false>* relinfo
,
3630 unsigned int sh_type
,
3631 const unsigned char* prelocs
,
3633 Output_section
* output_section
,
3634 bool needs_special_offset_handling
,
3635 unsigned char* view
,
3636 elfcpp::Elf_types
<32>::Elf_Addr address
,
3637 section_size_type view_size
,
3638 const Reloc_symbol_changes
* reloc_symbol_changes
)
3640 gold_assert(sh_type
== elfcpp::SHT_REL
);
3642 gold::relocate_section
<32, false, Target_i386
, Relocate
,
3643 gold::Default_comdat_behavior
, Classify_reloc
>(
3649 needs_special_offset_handling
,
3653 reloc_symbol_changes
);
3656 // Return the size of a relocation while scanning during a relocatable
3660 Target_i386::Classify_reloc::get_size_for_reloc(
3661 unsigned int r_type
,
3666 case elfcpp::R_386_NONE
:
3667 case elfcpp::R_386_GNU_VTINHERIT
:
3668 case elfcpp::R_386_GNU_VTENTRY
:
3669 case elfcpp::R_386_TLS_GD
: // Global-dynamic
3670 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
3671 case elfcpp::R_386_TLS_DESC_CALL
:
3672 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
3673 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
3674 case elfcpp::R_386_TLS_IE
: // Initial-exec
3675 case elfcpp::R_386_TLS_IE_32
:
3676 case elfcpp::R_386_TLS_GOTIE
:
3677 case elfcpp::R_386_TLS_LE
: // Local-exec
3678 case elfcpp::R_386_TLS_LE_32
:
3681 case elfcpp::R_386_32
:
3682 case elfcpp::R_386_PC32
:
3683 case elfcpp::R_386_GOT32
:
3684 case elfcpp::R_386_GOT32X
:
3685 case elfcpp::R_386_PLT32
:
3686 case elfcpp::R_386_GOTOFF
:
3687 case elfcpp::R_386_GOTPC
:
3690 case elfcpp::R_386_16
:
3691 case elfcpp::R_386_PC16
:
3694 case elfcpp::R_386_8
:
3695 case elfcpp::R_386_PC8
:
3698 // These are relocations which should only be seen by the
3699 // dynamic linker, and should never be seen here.
3700 case elfcpp::R_386_COPY
:
3701 case elfcpp::R_386_GLOB_DAT
:
3702 case elfcpp::R_386_JUMP_SLOT
:
3703 case elfcpp::R_386_RELATIVE
:
3704 case elfcpp::R_386_IRELATIVE
:
3705 case elfcpp::R_386_TLS_TPOFF
:
3706 case elfcpp::R_386_TLS_DTPMOD32
:
3707 case elfcpp::R_386_TLS_DTPOFF32
:
3708 case elfcpp::R_386_TLS_TPOFF32
:
3709 case elfcpp::R_386_TLS_DESC
:
3710 object
->error(_("unexpected reloc %u in object file"), r_type
);
3713 case elfcpp::R_386_32PLT
:
3714 case elfcpp::R_386_TLS_GD_32
:
3715 case elfcpp::R_386_TLS_GD_PUSH
:
3716 case elfcpp::R_386_TLS_GD_CALL
:
3717 case elfcpp::R_386_TLS_GD_POP
:
3718 case elfcpp::R_386_TLS_LDM_32
:
3719 case elfcpp::R_386_TLS_LDM_PUSH
:
3720 case elfcpp::R_386_TLS_LDM_CALL
:
3721 case elfcpp::R_386_TLS_LDM_POP
:
3722 case elfcpp::R_386_USED_BY_INTEL_200
:
3724 object
->error(_("unsupported reloc %u in object file"), r_type
);
3729 // Scan the relocs during a relocatable link.
3732 Target_i386::scan_relocatable_relocs(Symbol_table
* symtab
,
3734 Sized_relobj_file
<32, false>* object
,
3735 unsigned int data_shndx
,
3736 unsigned int sh_type
,
3737 const unsigned char* prelocs
,
3739 Output_section
* output_section
,
3740 bool needs_special_offset_handling
,
3741 size_t local_symbol_count
,
3742 const unsigned char* plocal_symbols
,
3743 Relocatable_relocs
* rr
)
3745 typedef gold::Default_scan_relocatable_relocs
<Classify_reloc
>
3746 Scan_relocatable_relocs
;
3748 gold_assert(sh_type
== elfcpp::SHT_REL
);
3750 gold::scan_relocatable_relocs
<32, false, Scan_relocatable_relocs
>(
3758 needs_special_offset_handling
,
3764 // Scan the relocs for --emit-relocs.
3767 Target_i386::emit_relocs_scan(Symbol_table
* symtab
,
3769 Sized_relobj_file
<32, false>* object
,
3770 unsigned int data_shndx
,
3771 unsigned int sh_type
,
3772 const unsigned char* prelocs
,
3774 Output_section
* output_section
,
3775 bool needs_special_offset_handling
,
3776 size_t local_symbol_count
,
3777 const unsigned char* plocal_syms
,
3778 Relocatable_relocs
* rr
)
3780 typedef gold::Default_classify_reloc
<elfcpp::SHT_REL
, 32, false>
3782 typedef gold::Default_emit_relocs_strategy
<Classify_reloc
>
3783 Emit_relocs_strategy
;
3785 gold_assert(sh_type
== elfcpp::SHT_REL
);
3787 gold::scan_relocatable_relocs
<32, false, Emit_relocs_strategy
>(
3795 needs_special_offset_handling
,
3801 // Emit relocations for a section.
3804 Target_i386::relocate_relocs(
3805 const Relocate_info
<32, false>* relinfo
,
3806 unsigned int sh_type
,
3807 const unsigned char* prelocs
,
3809 Output_section
* output_section
,
3810 elfcpp::Elf_types
<32>::Elf_Off offset_in_output_section
,
3811 unsigned char* view
,
3812 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
3813 section_size_type view_size
,
3814 unsigned char* reloc_view
,
3815 section_size_type reloc_view_size
)
3817 gold_assert(sh_type
== elfcpp::SHT_REL
);
3819 gold::relocate_relocs
<32, false, Classify_reloc
>(
3824 offset_in_output_section
,
3832 // Return the value to use for a dynamic which requires special
3833 // treatment. This is how we support equality comparisons of function
3834 // pointers across shared library boundaries, as described in the
3835 // processor specific ABI supplement.
3838 Target_i386::do_dynsym_value(const Symbol
* gsym
) const
3840 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
3841 return this->plt_address_for_global(gsym
);
3844 // Return a string used to fill a code section with nops to take up
3845 // the specified length.
3848 Target_i386::do_code_fill(section_size_type length
) const
3852 // Build a jmp instruction to skip over the bytes.
3853 unsigned char jmp
[5];
3855 elfcpp::Swap_unaligned
<32, false>::writeval(jmp
+ 1, length
- 5);
3856 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
3857 + std::string(length
- 5, static_cast<char>(0x90)));
3860 // Nop sequences of various lengths.
3861 const char nop1
[1] = { '\x90' }; // nop
3862 const char nop2
[2] = { '\x66', '\x90' }; // xchg %ax %ax
3863 const char nop3
[3] = { '\x8d', '\x76', '\x00' }; // leal 0(%esi),%esi
3864 const char nop4
[4] = { '\x8d', '\x74', '\x26', // leal 0(%esi,1),%esi
3866 const char nop5
[5] = { '\x90', '\x8d', '\x74', // nop
3867 '\x26', '\x00' }; // leal 0(%esi,1),%esi
3868 const char nop6
[6] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3869 '\x00', '\x00', '\x00' };
3870 const char nop7
[7] = { '\x8d', '\xb4', '\x26', // leal 0L(%esi,1),%esi
3871 '\x00', '\x00', '\x00',
3873 const char nop8
[8] = { '\x90', '\x8d', '\xb4', // nop
3874 '\x26', '\x00', '\x00', // leal 0L(%esi,1),%esi
3876 const char nop9
[9] = { '\x89', '\xf6', '\x8d', // movl %esi,%esi
3877 '\xbc', '\x27', '\x00', // leal 0L(%edi,1),%edi
3878 '\x00', '\x00', '\x00' };
3879 const char nop10
[10] = { '\x8d', '\x76', '\x00', // leal 0(%esi),%esi
3880 '\x8d', '\xbc', '\x27', // leal 0L(%edi,1),%edi
3881 '\x00', '\x00', '\x00',
3883 const char nop11
[11] = { '\x8d', '\x74', '\x26', // leal 0(%esi,1),%esi
3884 '\x00', '\x8d', '\xbc', // leal 0L(%edi,1),%edi
3885 '\x27', '\x00', '\x00',
3887 const char nop12
[12] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3888 '\x00', '\x00', '\x00', // leal 0L(%edi),%edi
3889 '\x8d', '\xbf', '\x00',
3890 '\x00', '\x00', '\x00' };
3891 const char nop13
[13] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3892 '\x00', '\x00', '\x00', // leal 0L(%edi,1),%edi
3893 '\x8d', '\xbc', '\x27',
3894 '\x00', '\x00', '\x00',
3896 const char nop14
[14] = { '\x8d', '\xb4', '\x26', // leal 0L(%esi,1),%esi
3897 '\x00', '\x00', '\x00', // leal 0L(%edi,1),%edi
3898 '\x00', '\x8d', '\xbc',
3899 '\x27', '\x00', '\x00',
3901 const char nop15
[15] = { '\xeb', '\x0d', '\x90', // jmp .+15
3902 '\x90', '\x90', '\x90', // nop,nop,nop,...
3903 '\x90', '\x90', '\x90',
3904 '\x90', '\x90', '\x90',
3905 '\x90', '\x90', '\x90' };
3907 const char* nops
[16] = {
3909 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
3910 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
3913 return std::string(nops
[length
], length
);
3916 // Return the value to use for the base of a DW_EH_PE_datarel offset
3917 // in an FDE. Solaris and SVR4 use DW_EH_PE_datarel because their
3918 // assembler can not write out the difference between two labels in
3919 // different sections, so instead of using a pc-relative value they
3920 // use an offset from the GOT.
3923 Target_i386::do_ehframe_datarel_base() const
3925 gold_assert(this->global_offset_table_
!= NULL
);
3926 Symbol
* sym
= this->global_offset_table_
;
3927 Sized_symbol
<32>* ssym
= static_cast<Sized_symbol
<32>*>(sym
);
3928 return ssym
->value();
3931 // Return whether SYM should be treated as a call to a non-split
3932 // function. We don't want that to be true of a call to a
3933 // get_pc_thunk function.
3936 Target_i386::do_is_call_to_non_split(const Symbol
* sym
,
3937 const unsigned char*,
3938 const unsigned char*,
3939 section_size_type
) const
3941 return (sym
->type() == elfcpp::STT_FUNC
3942 && !is_prefix_of("__i686.get_pc_thunk.", sym
->name()));
3945 // FNOFFSET in section SHNDX in OBJECT is the start of a function
3946 // compiled with -fsplit-stack. The function calls non-split-stack
3947 // code. We have to change the function so that it always ensures
3948 // that it has enough stack space to run some random function.
3951 Target_i386::do_calls_non_split(Relobj
* object
, unsigned int shndx
,
3952 section_offset_type fnoffset
,
3953 section_size_type fnsize
,
3954 const unsigned char*,
3956 unsigned char* view
,
3957 section_size_type view_size
,
3959 std::string
* to
) const
3961 // The function starts with a comparison of the stack pointer and a
3962 // field in the TCB. This is followed by a jump.
3965 if (this->match_view(view
, view_size
, fnoffset
, "\x65\x3b\x25", 3)
3968 // We will call __morestack if the carry flag is set after this
3969 // comparison. We turn the comparison into an stc instruction
3971 view
[fnoffset
] = '\xf9';
3972 this->set_view_to_nop(view
, view_size
, fnoffset
+ 1, 6);
3974 // lea NN(%esp),%ecx
3975 // lea NN(%esp),%edx
3976 else if ((this->match_view(view
, view_size
, fnoffset
, "\x8d\x8c\x24", 3)
3977 || this->match_view(view
, view_size
, fnoffset
, "\x8d\x94\x24", 3))
3980 // This is loading an offset from the stack pointer for a
3981 // comparison. The offset is negative, so we decrease the
3982 // offset by the amount of space we need for the stack. This
3983 // means we will avoid calling __morestack if there happens to
3984 // be plenty of space on the stack already.
3985 unsigned char* pval
= view
+ fnoffset
+ 3;
3986 uint32_t val
= elfcpp::Swap_unaligned
<32, false>::readval(pval
);
3987 val
-= parameters
->options().split_stack_adjust_size();
3988 elfcpp::Swap_unaligned
<32, false>::writeval(pval
, val
);
3992 if (!object
->has_no_split_stack())
3993 object
->error(_("failed to match split-stack sequence at "
3994 "section %u offset %0zx"),
3995 shndx
, static_cast<size_t>(fnoffset
));
3999 // We have to change the function so that it calls
4000 // __morestack_non_split instead of __morestack. The former will
4001 // allocate additional stack space.
4002 *from
= "__morestack";
4003 *to
= "__morestack_non_split";
4006 // The selector for i386 object files. Note this is never instantiated
4007 // directly. It's only used in Target_selector_i386_nacl, below.
4009 class Target_selector_i386
: public Target_selector_freebsd
4012 Target_selector_i386()
4013 : Target_selector_freebsd(elfcpp::EM_386
, 32, false,
4014 "elf32-i386", "elf32-i386-freebsd",
4019 do_instantiate_target()
4020 { return new Target_i386(); }
4023 // NaCl variant. It uses different PLT contents.
4025 class Output_data_plt_i386_nacl
: public Output_data_plt_i386
4028 Output_data_plt_i386_nacl(Layout
* layout
,
4029 Output_data_got_plt_i386
* got_plt
,
4030 Output_data_space
* got_irelative
)
4031 : Output_data_plt_i386(layout
, plt_entry_size
, got_plt
, got_irelative
)
4035 virtual unsigned int
4036 do_get_plt_entry_size() const
4037 { return plt_entry_size
; }
4040 do_add_eh_frame(Layout
* layout
)
4042 layout
->add_eh_frame_for_plt(this, plt_eh_frame_cie
, plt_eh_frame_cie_size
,
4043 plt_eh_frame_fde
, plt_eh_frame_fde_size
);
4046 // The size of an entry in the PLT.
4047 static const int plt_entry_size
= 64;
4049 // The .eh_frame unwind information for the PLT.
4050 static const int plt_eh_frame_fde_size
= 32;
4051 static const unsigned char plt_eh_frame_fde
[plt_eh_frame_fde_size
];
4054 class Output_data_plt_i386_nacl_exec
: public Output_data_plt_i386_nacl
4057 Output_data_plt_i386_nacl_exec(Layout
* layout
,
4058 Output_data_got_plt_i386
* got_plt
,
4059 Output_data_space
* got_irelative
)
4060 : Output_data_plt_i386_nacl(layout
, got_plt
, got_irelative
)
4065 do_fill_first_plt_entry(unsigned char* pov
,
4066 elfcpp::Elf_types
<32>::Elf_Addr got_address
);
4068 virtual unsigned int
4069 do_fill_plt_entry(unsigned char* pov
,
4070 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
4071 unsigned int got_offset
,
4072 unsigned int plt_offset
,
4073 unsigned int plt_rel_offset
);
4076 // The first entry in the PLT for an executable.
4077 static const unsigned char first_plt_entry
[plt_entry_size
];
4079 // Other entries in the PLT for an executable.
4080 static const unsigned char plt_entry
[plt_entry_size
];
4083 class Output_data_plt_i386_nacl_dyn
: public Output_data_plt_i386_nacl
4086 Output_data_plt_i386_nacl_dyn(Layout
* layout
,
4087 Output_data_got_plt_i386
* got_plt
,
4088 Output_data_space
* got_irelative
)
4089 : Output_data_plt_i386_nacl(layout
, got_plt
, got_irelative
)
4094 do_fill_first_plt_entry(unsigned char* pov
, elfcpp::Elf_types
<32>::Elf_Addr
);
4096 virtual unsigned int
4097 do_fill_plt_entry(unsigned char* pov
,
4098 elfcpp::Elf_types
<32>::Elf_Addr
,
4099 unsigned int got_offset
,
4100 unsigned int plt_offset
,
4101 unsigned int plt_rel_offset
);
4104 // The first entry in the PLT for a shared object.
4105 static const unsigned char first_plt_entry
[plt_entry_size
];
4107 // Other entries in the PLT for a shared object.
4108 static const unsigned char plt_entry
[plt_entry_size
];
4111 class Target_i386_nacl
: public Target_i386
4115 : Target_i386(&i386_nacl_info
)
4119 virtual Output_data_plt_i386
*
4120 do_make_data_plt(Layout
* layout
,
4121 Output_data_got_plt_i386
* got_plt
,
4122 Output_data_space
* got_irelative
,
4126 return new Output_data_plt_i386_nacl_dyn(layout
, got_plt
, got_irelative
);
4128 return new Output_data_plt_i386_nacl_exec(layout
, got_plt
, got_irelative
);
4132 do_code_fill(section_size_type length
) const;
4135 static const Target::Target_info i386_nacl_info
;
4138 const Target::Target_info
Target_i386_nacl::i386_nacl_info
=
4141 false, // is_big_endian
4142 elfcpp::EM_386
, // machine_code
4143 false, // has_make_symbol
4144 false, // has_resolve
4145 true, // has_code_fill
4146 true, // is_default_stack_executable
4147 true, // can_icf_inline_merge_sections
4149 "/lib/ld-nacl-x86-32.so.1", // dynamic_linker
4150 0x20000, // default_text_segment_address
4151 0x10000, // abi_pagesize (overridable by -z max-page-size)
4152 0x10000, // common_pagesize (overridable by -z common-page-size)
4153 true, // isolate_execinstr
4154 0x10000000, // rosegment_gap
4155 elfcpp::SHN_UNDEF
, // small_common_shndx
4156 elfcpp::SHN_UNDEF
, // large_common_shndx
4157 0, // small_common_section_flags
4158 0, // large_common_section_flags
4159 NULL
, // attributes_section
4160 NULL
, // attributes_vendor
4161 "_start", // entry_symbol_name
4162 32, // hash_entry_size
4165 #define NACLMASK 0xe0 // 32-byte alignment mask
4168 Output_data_plt_i386_nacl_exec::first_plt_entry
[plt_entry_size
] =
4170 0xff, 0x35, // pushl contents of memory address
4171 0, 0, 0, 0, // replaced with address of .got + 4
4172 0x8b, 0x0d, // movl contents of address, %ecx
4173 0, 0, 0, 0, // replaced with address of .got + 8
4174 0x83, 0xe1, NACLMASK
, // andl $NACLMASK, %ecx
4175 0xff, 0xe1, // jmp *%ecx
4176 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4177 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4178 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4179 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4180 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4181 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4182 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4183 0x90, 0x90, 0x90, 0x90, 0x90
4187 Output_data_plt_i386_nacl_exec::do_fill_first_plt_entry(
4189 elfcpp::Elf_types
<32>::Elf_Addr got_address
)
4191 memcpy(pov
, first_plt_entry
, plt_entry_size
);
4192 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 4);
4193 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 8);
4196 // The first entry in the PLT for a shared object.
4199 Output_data_plt_i386_nacl_dyn::first_plt_entry
[plt_entry_size
] =
4201 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
4202 0x8b, 0x4b, 0x08, // mov 0x8(%ebx), %ecx
4203 0x83, 0xe1, NACLMASK
, // andl $NACLMASK, %ecx
4204 0xff, 0xe1, // jmp *%ecx
4205 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4206 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4207 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4208 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4209 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4210 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4211 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4212 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4213 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4214 0x90, 0x90, 0x90, 0x90, 0x90 // nops
4218 Output_data_plt_i386_nacl_dyn::do_fill_first_plt_entry(
4220 elfcpp::Elf_types
<32>::Elf_Addr
)
4222 memcpy(pov
, first_plt_entry
, plt_entry_size
);
4225 // Subsequent entries in the PLT for an executable.
4228 Output_data_plt_i386_nacl_exec::plt_entry
[plt_entry_size
] =
4230 0x8b, 0x0d, // movl contents of address, %ecx */
4231 0, 0, 0, 0, // replaced with address of symbol in .got
4232 0x83, 0xe1, NACLMASK
, // andl $NACLMASK, %ecx
4233 0xff, 0xe1, // jmp *%ecx
4235 // Pad to the next 32-byte boundary with nop instructions.
4237 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4238 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4240 // Lazy GOT entries point here (32-byte aligned).
4241 0x68, // pushl immediate
4242 0, 0, 0, 0, // replaced with offset into relocation table
4243 0xe9, // jmp relative
4244 0, 0, 0, 0, // replaced with offset to start of .plt
4246 // Pad to the next 32-byte boundary with nop instructions.
4247 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4248 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4253 Output_data_plt_i386_nacl_exec::do_fill_plt_entry(
4255 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
4256 unsigned int got_offset
,
4257 unsigned int plt_offset
,
4258 unsigned int plt_rel_offset
)
4260 memcpy(pov
, plt_entry
, plt_entry_size
);
4261 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
4262 got_address
+ got_offset
);
4263 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 33, plt_rel_offset
);
4264 elfcpp::Swap
<32, false>::writeval(pov
+ 38, - (plt_offset
+ 38 + 4));
4268 // Subsequent entries in the PLT for a shared object.
4271 Output_data_plt_i386_nacl_dyn::plt_entry
[plt_entry_size
] =
4273 0x8b, 0x8b, // movl offset(%ebx), %ecx
4274 0, 0, 0, 0, // replaced with offset of symbol in .got
4275 0x83, 0xe1, 0xe0, // andl $NACLMASK, %ecx
4276 0xff, 0xe1, // jmp *%ecx
4278 // Pad to the next 32-byte boundary with nop instructions.
4280 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4281 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4283 // Lazy GOT entries point here (32-byte aligned).
4284 0x68, // pushl immediate
4285 0, 0, 0, 0, // replaced with offset into relocation table.
4286 0xe9, // jmp relative
4287 0, 0, 0, 0, // replaced with offset to start of .plt.
4289 // Pad to the next 32-byte boundary with nop instructions.
4290 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4291 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4296 Output_data_plt_i386_nacl_dyn::do_fill_plt_entry(
4298 elfcpp::Elf_types
<32>::Elf_Addr
,
4299 unsigned int got_offset
,
4300 unsigned int plt_offset
,
4301 unsigned int plt_rel_offset
)
4303 memcpy(pov
, plt_entry
, plt_entry_size
);
4304 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
4305 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 33, plt_rel_offset
);
4306 elfcpp::Swap
<32, false>::writeval(pov
+ 38, - (plt_offset
+ 38 + 4));
4311 Output_data_plt_i386_nacl::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
4313 0, 0, 0, 0, // Replaced with offset to .plt.
4314 0, 0, 0, 0, // Replaced with size of .plt.
4315 0, // Augmentation size.
4316 elfcpp::DW_CFA_def_cfa_offset
, 8, // DW_CFA_def_cfa_offset: 8.
4317 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
4318 elfcpp::DW_CFA_def_cfa_offset
, 12, // DW_CFA_def_cfa_offset: 12.
4319 elfcpp::DW_CFA_advance_loc
+ 58, // Advance 58 to __PLT__ + 64.
4320 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
4321 13, // Block length.
4322 elfcpp::DW_OP_breg4
, 4, // Push %esp + 4.
4323 elfcpp::DW_OP_breg8
, 0, // Push %eip.
4324 elfcpp::DW_OP_const1u
, 63, // Push 0x3f.
4325 elfcpp::DW_OP_and
, // & (%eip & 0x3f).
4326 elfcpp::DW_OP_const1u
, 37, // Push 0x25.
4327 elfcpp::DW_OP_ge
, // >= ((%eip & 0x3f) >= 0x25)
4328 elfcpp::DW_OP_lit2
, // Push 2.
4329 elfcpp::DW_OP_shl
, // << (((%eip & 0x3f) >= 0x25) << 2)
4330 elfcpp::DW_OP_plus
, // + ((((%eip&0x3f)>=0x25)<<2)+%esp+4
4331 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
4335 // Return a string used to fill a code section with nops.
4336 // For NaCl, long NOPs are only valid if they do not cross
4337 // bundle alignment boundaries, so keep it simple with one-byte NOPs.
4339 Target_i386_nacl::do_code_fill(section_size_type length
) const
4341 return std::string(length
, static_cast<char>(0x90));
4344 // The selector for i386-nacl object files.
4346 class Target_selector_i386_nacl
4347 : public Target_selector_nacl
<Target_selector_i386
, Target_i386_nacl
>
4350 Target_selector_i386_nacl()
4351 : Target_selector_nacl
<Target_selector_i386
,
4352 Target_i386_nacl
>("x86-32",
4358 Target_selector_i386_nacl target_selector_i386
;
4360 // IAMCU variant. It uses EM_IAMCU, not EM_386.
4362 class Target_iamcu
: public Target_i386
4366 : Target_i386(&iamcu_info
)
4370 // Information about this specific target which we pass to the
4371 // general Target structure.
4372 static const Target::Target_info iamcu_info
;
4375 const Target::Target_info
Target_iamcu::iamcu_info
=
4378 false, // is_big_endian
4379 elfcpp::EM_IAMCU
, // machine_code
4380 false, // has_make_symbol
4381 false, // has_resolve
4382 true, // has_code_fill
4383 true, // is_default_stack_executable
4384 true, // can_icf_inline_merge_sections
4386 "/usr/lib/libc.so.1", // dynamic_linker
4387 0x08048000, // default_text_segment_address
4388 0x1000, // abi_pagesize (overridable by -z max-page-size)
4389 0x1000, // common_pagesize (overridable by -z common-page-size)
4390 false, // isolate_execinstr
4392 elfcpp::SHN_UNDEF
, // small_common_shndx
4393 elfcpp::SHN_UNDEF
, // large_common_shndx
4394 0, // small_common_section_flags
4395 0, // large_common_section_flags
4396 NULL
, // attributes_section
4397 NULL
, // attributes_vendor
4398 "_start", // entry_symbol_name
4399 32, // hash_entry_size
4402 class Target_selector_iamcu
: public Target_selector
4405 Target_selector_iamcu()
4406 : Target_selector(elfcpp::EM_IAMCU
, 32, false, "elf32-iamcu",
4411 do_instantiate_target()
4412 { return new Target_iamcu(); }
4415 Target_selector_iamcu target_selector_iamcu
;
4417 } // End anonymous namespace.