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 if (this->plt_
== NULL
)
1570 return this->plt_
->first_plt_entry_offset();
1573 // Return the size of each PLT entry.
1576 Target_i386::plt_entry_size() const
1578 if (this->plt_
== NULL
)
1580 return this->plt_
->get_plt_entry_size();
1583 // Get the section to use for TLS_DESC relocations.
1585 Target_i386::Reloc_section
*
1586 Target_i386::rel_tls_desc_section(Layout
* layout
) const
1588 return this->plt_section()->rel_tls_desc(layout
);
1591 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1594 Target_i386::define_tls_base_symbol(Symbol_table
* symtab
, Layout
* layout
)
1596 if (this->tls_base_symbol_defined_
)
1599 Output_segment
* tls_segment
= layout
->tls_segment();
1600 if (tls_segment
!= NULL
)
1602 bool is_exec
= parameters
->options().output_is_executable();
1603 symtab
->define_in_output_segment("_TLS_MODULE_BASE_", NULL
,
1604 Symbol_table::PREDEFINED
,
1608 elfcpp::STV_HIDDEN
, 0,
1610 ? Symbol::SEGMENT_END
1611 : Symbol::SEGMENT_START
),
1614 this->tls_base_symbol_defined_
= true;
1617 // Create a GOT entry for the TLS module index.
1620 Target_i386::got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
1621 Sized_relobj_file
<32, false>* object
)
1623 if (this->got_mod_index_offset_
== -1U)
1625 gold_assert(symtab
!= NULL
&& layout
!= NULL
&& object
!= NULL
);
1626 Reloc_section
* rel_dyn
= this->rel_dyn_section(layout
);
1627 Output_data_got
<32, false>* got
= this->got_section(symtab
, layout
);
1628 unsigned int got_offset
= got
->add_constant(0);
1629 rel_dyn
->add_local(object
, 0, elfcpp::R_386_TLS_DTPMOD32
, got
,
1631 got
->add_constant(0);
1632 this->got_mod_index_offset_
= got_offset
;
1634 return this->got_mod_index_offset_
;
1637 // Optimize the TLS relocation type based on what we know about the
1638 // symbol. IS_FINAL is true if the final address of this symbol is
1639 // known at link time.
1641 tls::Tls_optimization
1642 Target_i386::optimize_tls_reloc(bool is_final
, int r_type
)
1644 // If we are generating a shared library, then we can't do anything
1646 if (parameters
->options().shared())
1647 return tls::TLSOPT_NONE
;
1651 case elfcpp::R_386_TLS_GD
:
1652 case elfcpp::R_386_TLS_GOTDESC
:
1653 case elfcpp::R_386_TLS_DESC_CALL
:
1654 // These are General-Dynamic which permits fully general TLS
1655 // access. Since we know that we are generating an executable,
1656 // we can convert this to Initial-Exec. If we also know that
1657 // this is a local symbol, we can further switch to Local-Exec.
1659 return tls::TLSOPT_TO_LE
;
1660 return tls::TLSOPT_TO_IE
;
1662 case elfcpp::R_386_TLS_LDM
:
1663 // This is Local-Dynamic, which refers to a local symbol in the
1664 // dynamic TLS block. Since we know that we generating an
1665 // executable, we can switch to Local-Exec.
1666 return tls::TLSOPT_TO_LE
;
1668 case elfcpp::R_386_TLS_LDO_32
:
1669 // Another type of Local-Dynamic relocation.
1670 return tls::TLSOPT_TO_LE
;
1672 case elfcpp::R_386_TLS_IE
:
1673 case elfcpp::R_386_TLS_GOTIE
:
1674 case elfcpp::R_386_TLS_IE_32
:
1675 // These are Initial-Exec relocs which get the thread offset
1676 // from the GOT. If we know that we are linking against the
1677 // local symbol, we can switch to Local-Exec, which links the
1678 // thread offset into the instruction.
1680 return tls::TLSOPT_TO_LE
;
1681 return tls::TLSOPT_NONE
;
1683 case elfcpp::R_386_TLS_LE
:
1684 case elfcpp::R_386_TLS_LE_32
:
1685 // When we already have Local-Exec, there is nothing further we
1687 return tls::TLSOPT_NONE
;
1694 // Get the Reference_flags for a particular relocation.
1697 Target_i386::Scan::get_reference_flags(unsigned int r_type
)
1701 case elfcpp::R_386_NONE
:
1702 case elfcpp::R_386_GNU_VTINHERIT
:
1703 case elfcpp::R_386_GNU_VTENTRY
:
1704 case elfcpp::R_386_GOTPC
:
1705 // No symbol reference.
1708 case elfcpp::R_386_32
:
1709 case elfcpp::R_386_16
:
1710 case elfcpp::R_386_8
:
1711 return Symbol::ABSOLUTE_REF
;
1713 case elfcpp::R_386_PC32
:
1714 case elfcpp::R_386_PC16
:
1715 case elfcpp::R_386_PC8
:
1716 case elfcpp::R_386_GOTOFF
:
1717 return Symbol::RELATIVE_REF
;
1719 case elfcpp::R_386_PLT32
:
1720 return Symbol::FUNCTION_CALL
| Symbol::RELATIVE_REF
;
1722 case elfcpp::R_386_GOT32
:
1723 case elfcpp::R_386_GOT32X
:
1725 return Symbol::ABSOLUTE_REF
;
1727 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1728 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1729 case elfcpp::R_386_TLS_DESC_CALL
:
1730 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1731 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1732 case elfcpp::R_386_TLS_IE
: // Initial-exec
1733 case elfcpp::R_386_TLS_IE_32
:
1734 case elfcpp::R_386_TLS_GOTIE
:
1735 case elfcpp::R_386_TLS_LE
: // Local-exec
1736 case elfcpp::R_386_TLS_LE_32
:
1737 return Symbol::TLS_REF
;
1739 case elfcpp::R_386_COPY
:
1740 case elfcpp::R_386_GLOB_DAT
:
1741 case elfcpp::R_386_JUMP_SLOT
:
1742 case elfcpp::R_386_RELATIVE
:
1743 case elfcpp::R_386_IRELATIVE
:
1744 case elfcpp::R_386_TLS_TPOFF
:
1745 case elfcpp::R_386_TLS_DTPMOD32
:
1746 case elfcpp::R_386_TLS_DTPOFF32
:
1747 case elfcpp::R_386_TLS_TPOFF32
:
1748 case elfcpp::R_386_TLS_DESC
:
1749 case elfcpp::R_386_32PLT
:
1750 case elfcpp::R_386_TLS_GD_32
:
1751 case elfcpp::R_386_TLS_GD_PUSH
:
1752 case elfcpp::R_386_TLS_GD_CALL
:
1753 case elfcpp::R_386_TLS_GD_POP
:
1754 case elfcpp::R_386_TLS_LDM_32
:
1755 case elfcpp::R_386_TLS_LDM_PUSH
:
1756 case elfcpp::R_386_TLS_LDM_CALL
:
1757 case elfcpp::R_386_TLS_LDM_POP
:
1758 case elfcpp::R_386_USED_BY_INTEL_200
:
1760 // Not expected. We will give an error later.
1765 // Report an unsupported relocation against a local symbol.
1768 Target_i386::Scan::unsupported_reloc_local(Sized_relobj_file
<32, false>* object
,
1769 unsigned int r_type
)
1771 gold_error(_("%s: unsupported reloc %u against local symbol"),
1772 object
->name().c_str(), r_type
);
1775 // Return whether we need to make a PLT entry for a relocation of a
1776 // given type against a STT_GNU_IFUNC symbol.
1779 Target_i386::Scan::reloc_needs_plt_for_ifunc(
1780 Sized_relobj_file
<32, false>* object
,
1781 unsigned int r_type
)
1783 int flags
= Scan::get_reference_flags(r_type
);
1784 if (flags
& Symbol::TLS_REF
)
1785 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
1786 object
->name().c_str(), r_type
);
1790 // Scan a relocation for a local symbol.
1793 Target_i386::Scan::local(Symbol_table
* symtab
,
1795 Target_i386
* target
,
1796 Sized_relobj_file
<32, false>* object
,
1797 unsigned int data_shndx
,
1798 Output_section
* output_section
,
1799 const elfcpp::Rel
<32, false>& reloc
,
1800 unsigned int r_type
,
1801 const elfcpp::Sym
<32, false>& lsym
,
1807 // A local STT_GNU_IFUNC symbol may require a PLT entry.
1808 if (lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
1809 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
1811 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1812 target
->make_local_ifunc_plt_entry(symtab
, layout
, object
, r_sym
);
1817 case elfcpp::R_386_NONE
:
1818 case elfcpp::R_386_GNU_VTINHERIT
:
1819 case elfcpp::R_386_GNU_VTENTRY
:
1822 case elfcpp::R_386_32
:
1823 // If building a shared library (or a position-independent
1824 // executable), we need to create a dynamic relocation for
1825 // this location. The relocation applied at link time will
1826 // apply the link-time value, so we flag the location with
1827 // an R_386_RELATIVE relocation so the dynamic loader can
1828 // relocate it easily.
1829 if (parameters
->options().output_is_position_independent())
1831 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1832 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1833 rel_dyn
->add_local_relative(object
, r_sym
, elfcpp::R_386_RELATIVE
,
1834 output_section
, data_shndx
,
1835 reloc
.get_r_offset());
1839 case elfcpp::R_386_16
:
1840 case elfcpp::R_386_8
:
1841 // If building a shared library (or a position-independent
1842 // executable), we need to create a dynamic relocation for
1843 // this location. Because the addend needs to remain in the
1844 // data section, we need to be careful not to apply this
1845 // relocation statically.
1846 if (parameters
->options().output_is_position_independent())
1848 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1849 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1850 if (lsym
.get_st_type() != elfcpp::STT_SECTION
)
1851 rel_dyn
->add_local(object
, r_sym
, r_type
, output_section
,
1852 data_shndx
, reloc
.get_r_offset());
1855 gold_assert(lsym
.get_st_value() == 0);
1856 unsigned int shndx
= lsym
.get_st_shndx();
1858 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
,
1861 object
->error(_("section symbol %u has bad shndx %u"),
1864 rel_dyn
->add_local_section(object
, shndx
,
1865 r_type
, output_section
,
1866 data_shndx
, reloc
.get_r_offset());
1871 case elfcpp::R_386_PC32
:
1872 case elfcpp::R_386_PC16
:
1873 case elfcpp::R_386_PC8
:
1876 case elfcpp::R_386_PLT32
:
1877 // Since we know this is a local symbol, we can handle this as a
1881 case elfcpp::R_386_GOTOFF
:
1882 case elfcpp::R_386_GOTPC
:
1883 // We need a GOT section.
1884 target
->got_section(symtab
, layout
);
1887 case elfcpp::R_386_GOT32
:
1888 case elfcpp::R_386_GOT32X
:
1890 // We need GOT section.
1891 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
1893 // If the relocation symbol isn't IFUNC,
1894 // and is local, then we will convert
1895 // mov foo@GOT(%reg), %reg
1897 // lea foo@GOTOFF(%reg), %reg
1898 // in Relocate::relocate.
1899 if (reloc
.get_r_offset() >= 2
1900 && lsym
.get_st_type() != elfcpp::STT_GNU_IFUNC
)
1902 section_size_type stype
;
1903 const unsigned char* view
= object
->section_contents(data_shndx
,
1905 if (view
[reloc
.get_r_offset() - 2] == 0x8b)
1909 // Otherwise, the symbol requires a GOT entry.
1910 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1912 // For a STT_GNU_IFUNC symbol we want the PLT offset. That
1913 // lets function pointers compare correctly with shared
1914 // libraries. Otherwise we would need an IRELATIVE reloc.
1916 if (lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
)
1917 is_new
= got
->add_local_plt(object
, r_sym
, GOT_TYPE_STANDARD
);
1919 is_new
= got
->add_local(object
, r_sym
, GOT_TYPE_STANDARD
);
1922 // If we are generating a shared object, we need to add a
1923 // dynamic RELATIVE relocation for this symbol's GOT entry.
1924 if (parameters
->options().output_is_position_independent())
1926 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1927 unsigned int got_offset
=
1928 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
);
1929 rel_dyn
->add_local_relative(object
, r_sym
,
1930 elfcpp::R_386_RELATIVE
,
1937 // These are relocations which should only be seen by the
1938 // dynamic linker, and should never be seen here.
1939 case elfcpp::R_386_COPY
:
1940 case elfcpp::R_386_GLOB_DAT
:
1941 case elfcpp::R_386_JUMP_SLOT
:
1942 case elfcpp::R_386_RELATIVE
:
1943 case elfcpp::R_386_IRELATIVE
:
1944 case elfcpp::R_386_TLS_TPOFF
:
1945 case elfcpp::R_386_TLS_DTPMOD32
:
1946 case elfcpp::R_386_TLS_DTPOFF32
:
1947 case elfcpp::R_386_TLS_TPOFF32
:
1948 case elfcpp::R_386_TLS_DESC
:
1949 gold_error(_("%s: unexpected reloc %u in object file"),
1950 object
->name().c_str(), r_type
);
1953 // These are initial TLS relocs, which are expected when
1955 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1956 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1957 case elfcpp::R_386_TLS_DESC_CALL
:
1958 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1959 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1960 case elfcpp::R_386_TLS_IE
: // Initial-exec
1961 case elfcpp::R_386_TLS_IE_32
:
1962 case elfcpp::R_386_TLS_GOTIE
:
1963 case elfcpp::R_386_TLS_LE
: // Local-exec
1964 case elfcpp::R_386_TLS_LE_32
:
1966 bool output_is_shared
= parameters
->options().shared();
1967 const tls::Tls_optimization optimized_type
1968 = Target_i386::optimize_tls_reloc(!output_is_shared
, r_type
);
1971 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1972 if (optimized_type
== tls::TLSOPT_NONE
)
1974 // Create a pair of GOT entries for the module index and
1975 // dtv-relative offset.
1976 Output_data_got
<32, false>* got
1977 = target
->got_section(symtab
, layout
);
1978 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1979 unsigned int shndx
= lsym
.get_st_shndx();
1981 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
1983 object
->error(_("local symbol %u has bad shndx %u"),
1986 got
->add_local_pair_with_rel(object
, r_sym
, shndx
,
1988 target
->rel_dyn_section(layout
),
1989 elfcpp::R_386_TLS_DTPMOD32
);
1991 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1992 unsupported_reloc_local(object
, r_type
);
1995 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva)
1996 target
->define_tls_base_symbol(symtab
, layout
);
1997 if (optimized_type
== tls::TLSOPT_NONE
)
1999 // Create a double GOT entry with an R_386_TLS_DESC
2000 // reloc. The R_386_TLS_DESC reloc is resolved
2001 // lazily, so the GOT entry needs to be in an area in
2002 // .got.plt, not .got. Call got_section to make sure
2003 // the section has been created.
2004 target
->got_section(symtab
, layout
);
2005 Output_data_got
<32, false>* got
= target
->got_tlsdesc_section();
2006 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
2007 if (!object
->local_has_got_offset(r_sym
, GOT_TYPE_TLS_DESC
))
2009 unsigned int got_offset
= got
->add_constant(0);
2010 // The local symbol value is stored in the second
2012 got
->add_local(object
, r_sym
, GOT_TYPE_TLS_DESC
);
2013 // That set the GOT offset of the local symbol to
2014 // point to the second entry, but we want it to
2015 // point to the first.
2016 object
->set_local_got_offset(r_sym
, GOT_TYPE_TLS_DESC
,
2018 Reloc_section
* rt
= target
->rel_tls_desc_section(layout
);
2019 rt
->add_absolute(elfcpp::R_386_TLS_DESC
, got
, got_offset
);
2022 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2023 unsupported_reloc_local(object
, r_type
);
2026 case elfcpp::R_386_TLS_DESC_CALL
:
2029 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2030 if (optimized_type
== tls::TLSOPT_NONE
)
2032 // Create a GOT entry for the module index.
2033 target
->got_mod_index_entry(symtab
, layout
, object
);
2035 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2036 unsupported_reloc_local(object
, r_type
);
2039 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2042 case elfcpp::R_386_TLS_IE
: // Initial-exec
2043 case elfcpp::R_386_TLS_IE_32
:
2044 case elfcpp::R_386_TLS_GOTIE
:
2045 layout
->set_has_static_tls();
2046 if (optimized_type
== tls::TLSOPT_NONE
)
2048 // For the R_386_TLS_IE relocation, we need to create a
2049 // dynamic relocation when building a shared library.
2050 if (r_type
== elfcpp::R_386_TLS_IE
2051 && parameters
->options().shared())
2053 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2055 = elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
2056 rel_dyn
->add_local_relative(object
, r_sym
,
2057 elfcpp::R_386_RELATIVE
,
2058 output_section
, data_shndx
,
2059 reloc
.get_r_offset());
2061 // Create a GOT entry for the tp-relative offset.
2062 Output_data_got
<32, false>* got
2063 = target
->got_section(symtab
, layout
);
2064 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
2065 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2066 ? elfcpp::R_386_TLS_TPOFF32
2067 : elfcpp::R_386_TLS_TPOFF
);
2068 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2069 ? GOT_TYPE_TLS_OFFSET
2070 : GOT_TYPE_TLS_NOFFSET
);
2071 got
->add_local_with_rel(object
, r_sym
, got_type
,
2072 target
->rel_dyn_section(layout
),
2075 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2076 unsupported_reloc_local(object
, r_type
);
2079 case elfcpp::R_386_TLS_LE
: // Local-exec
2080 case elfcpp::R_386_TLS_LE_32
:
2081 layout
->set_has_static_tls();
2082 if (output_is_shared
)
2084 // We need to create a dynamic relocation.
2085 gold_assert(lsym
.get_st_type() != elfcpp::STT_SECTION
);
2086 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
2087 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
2088 ? elfcpp::R_386_TLS_TPOFF32
2089 : elfcpp::R_386_TLS_TPOFF
);
2090 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2091 rel_dyn
->add_local(object
, r_sym
, dyn_r_type
, output_section
,
2092 data_shndx
, reloc
.get_r_offset());
2102 case elfcpp::R_386_32PLT
:
2103 case elfcpp::R_386_TLS_GD_32
:
2104 case elfcpp::R_386_TLS_GD_PUSH
:
2105 case elfcpp::R_386_TLS_GD_CALL
:
2106 case elfcpp::R_386_TLS_GD_POP
:
2107 case elfcpp::R_386_TLS_LDM_32
:
2108 case elfcpp::R_386_TLS_LDM_PUSH
:
2109 case elfcpp::R_386_TLS_LDM_CALL
:
2110 case elfcpp::R_386_TLS_LDM_POP
:
2111 case elfcpp::R_386_USED_BY_INTEL_200
:
2113 unsupported_reloc_local(object
, r_type
);
2118 // Report an unsupported relocation against a global symbol.
2121 Target_i386::Scan::unsupported_reloc_global(
2122 Sized_relobj_file
<32, false>* object
,
2123 unsigned int r_type
,
2126 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
2127 object
->name().c_str(), r_type
, gsym
->demangled_name().c_str());
2131 Target_i386::Scan::possible_function_pointer_reloc(unsigned int r_type
)
2135 case elfcpp::R_386_32
:
2136 case elfcpp::R_386_16
:
2137 case elfcpp::R_386_8
:
2138 case elfcpp::R_386_GOTOFF
:
2139 case elfcpp::R_386_GOT32
:
2140 case elfcpp::R_386_GOT32X
:
2151 Target_i386::Scan::local_reloc_may_be_function_pointer(
2155 Sized_relobj_file
<32, false>* ,
2158 const elfcpp::Rel
<32, false>& ,
2159 unsigned int r_type
,
2160 const elfcpp::Sym
<32, false>&)
2162 return possible_function_pointer_reloc(r_type
);
2166 Target_i386::Scan::global_reloc_may_be_function_pointer(
2170 Sized_relobj_file
<32, false>* ,
2173 const elfcpp::Rel
<32, false>& ,
2174 unsigned int r_type
,
2177 return possible_function_pointer_reloc(r_type
);
2180 // Scan a relocation for a global symbol.
2183 Target_i386::Scan::global(Symbol_table
* symtab
,
2185 Target_i386
* target
,
2186 Sized_relobj_file
<32, false>* object
,
2187 unsigned int data_shndx
,
2188 Output_section
* output_section
,
2189 const elfcpp::Rel
<32, false>& reloc
,
2190 unsigned int r_type
,
2193 // A STT_GNU_IFUNC symbol may require a PLT entry.
2194 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
2195 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
2196 target
->make_plt_entry(symtab
, layout
, gsym
);
2200 case elfcpp::R_386_NONE
:
2201 case elfcpp::R_386_GNU_VTINHERIT
:
2202 case elfcpp::R_386_GNU_VTENTRY
:
2205 case elfcpp::R_386_32
:
2206 case elfcpp::R_386_16
:
2207 case elfcpp::R_386_8
:
2209 // Make a PLT entry if necessary.
2210 if (gsym
->needs_plt_entry())
2212 target
->make_plt_entry(symtab
, layout
, gsym
);
2213 // Since this is not a PC-relative relocation, we may be
2214 // taking the address of a function. In that case we need to
2215 // set the entry in the dynamic symbol table to the address of
2217 if (gsym
->is_from_dynobj() && !parameters
->options().shared())
2218 gsym
->set_needs_dynsym_value();
2220 // Make a dynamic relocation if necessary.
2221 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
2223 if (!parameters
->options().output_is_position_independent()
2224 && gsym
->may_need_copy_reloc())
2226 target
->copy_reloc(symtab
, layout
, object
,
2227 data_shndx
, output_section
, gsym
, reloc
);
2229 else if (r_type
== elfcpp::R_386_32
2230 && gsym
->type() == elfcpp::STT_GNU_IFUNC
2231 && gsym
->can_use_relative_reloc(false)
2232 && !gsym
->is_from_dynobj()
2233 && !gsym
->is_undefined()
2234 && !gsym
->is_preemptible())
2236 // Use an IRELATIVE reloc for a locally defined
2237 // STT_GNU_IFUNC symbol. This makes a function
2238 // address in a PIE executable match the address in a
2239 // shared library that it links against.
2240 Reloc_section
* rel_dyn
= target
->rel_irelative_section(layout
);
2241 rel_dyn
->add_symbolless_global_addend(gsym
,
2242 elfcpp::R_386_IRELATIVE
,
2245 reloc
.get_r_offset());
2247 else if (r_type
== elfcpp::R_386_32
2248 && gsym
->can_use_relative_reloc(false))
2250 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2251 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
2252 output_section
, object
,
2253 data_shndx
, reloc
.get_r_offset());
2257 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2258 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
2259 data_shndx
, reloc
.get_r_offset());
2265 case elfcpp::R_386_PC32
:
2266 case elfcpp::R_386_PC16
:
2267 case elfcpp::R_386_PC8
:
2269 // Make a PLT entry if necessary.
2270 if (gsym
->needs_plt_entry())
2272 // These relocations are used for function calls only in
2273 // non-PIC code. For a 32-bit relocation in a shared library,
2274 // we'll need a text relocation anyway, so we can skip the
2275 // PLT entry and let the dynamic linker bind the call directly
2276 // to the target. For smaller relocations, we should use a
2277 // PLT entry to ensure that the call can reach.
2278 if (!parameters
->options().shared()
2279 || r_type
!= elfcpp::R_386_PC32
)
2280 target
->make_plt_entry(symtab
, layout
, gsym
);
2282 // Make a dynamic relocation if necessary.
2283 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
2285 if (parameters
->options().output_is_executable()
2286 && gsym
->may_need_copy_reloc())
2288 target
->copy_reloc(symtab
, layout
, object
,
2289 data_shndx
, output_section
, gsym
, reloc
);
2293 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2294 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
2295 data_shndx
, reloc
.get_r_offset());
2301 case elfcpp::R_386_GOT32
:
2302 case elfcpp::R_386_GOT32X
:
2304 // The symbol requires a GOT section.
2305 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
2307 // If we convert this from
2308 // mov foo@GOT(%reg), %reg
2310 // lea foo@GOTOFF(%reg), %reg
2311 // in Relocate::relocate, then there is nothing to do here.
2312 if (reloc
.get_r_offset() >= 2
2313 && Target_i386::can_convert_mov_to_lea(gsym
))
2315 section_size_type stype
;
2316 const unsigned char* view
= object
->section_contents(data_shndx
,
2318 if (view
[reloc
.get_r_offset() - 2] == 0x8b)
2322 if (gsym
->final_value_is_known())
2324 // For a STT_GNU_IFUNC symbol we want the PLT address.
2325 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
)
2326 got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
2328 got
->add_global(gsym
, GOT_TYPE_STANDARD
);
2332 // If this symbol is not fully resolved, we need to add a
2333 // GOT entry with a dynamic relocation.
2334 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2336 // Use a GLOB_DAT rather than a RELATIVE reloc if:
2338 // 1) The symbol may be defined in some other module.
2340 // 2) We are building a shared library and this is a
2341 // protected symbol; using GLOB_DAT means that the dynamic
2342 // linker can use the address of the PLT in the main
2343 // executable when appropriate so that function address
2344 // comparisons work.
2346 // 3) This is a STT_GNU_IFUNC symbol in position dependent
2347 // code, again so that function address comparisons work.
2348 if (gsym
->is_from_dynobj()
2349 || gsym
->is_undefined()
2350 || gsym
->is_preemptible()
2351 || (gsym
->visibility() == elfcpp::STV_PROTECTED
2352 && parameters
->options().shared())
2353 || (gsym
->type() == elfcpp::STT_GNU_IFUNC
2354 && parameters
->options().output_is_position_independent()))
2355 got
->add_global_with_rel(gsym
, GOT_TYPE_STANDARD
,
2356 rel_dyn
, elfcpp::R_386_GLOB_DAT
);
2359 // For a STT_GNU_IFUNC symbol we want to write the PLT
2360 // offset into the GOT, so that function pointer
2361 // comparisons work correctly.
2363 if (gsym
->type() != elfcpp::STT_GNU_IFUNC
)
2364 is_new
= got
->add_global(gsym
, GOT_TYPE_STANDARD
);
2367 is_new
= got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
2368 // Tell the dynamic linker to use the PLT address
2369 // when resolving relocations.
2370 if (gsym
->is_from_dynobj()
2371 && !parameters
->options().shared())
2372 gsym
->set_needs_dynsym_value();
2376 unsigned int got_off
= gsym
->got_offset(GOT_TYPE_STANDARD
);
2377 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
2385 case elfcpp::R_386_PLT32
:
2386 // If the symbol is fully resolved, this is just a PC32 reloc.
2387 // Otherwise we need a PLT entry.
2388 if (gsym
->final_value_is_known())
2390 // If building a shared library, we can also skip the PLT entry
2391 // if the symbol is defined in the output file and is protected
2393 if (gsym
->is_defined()
2394 && !gsym
->is_from_dynobj()
2395 && !gsym
->is_preemptible())
2397 target
->make_plt_entry(symtab
, layout
, gsym
);
2400 case elfcpp::R_386_GOTOFF
:
2401 // A GOT-relative reference must resolve locally.
2402 if (!gsym
->is_defined())
2403 gold_error(_("%s: relocation R_386_GOTOFF against undefined symbol %s"
2404 " cannot be used when making a shared object"),
2405 object
->name().c_str(), gsym
->name());
2406 else if (gsym
->is_from_dynobj())
2407 gold_error(_("%s: relocation R_386_GOTOFF against external symbol %s"
2408 " cannot be used when making a shared object"),
2409 object
->name().c_str(), gsym
->name());
2410 else if (gsym
->is_preemptible())
2411 gold_error(_("%s: relocation R_386_GOTOFF against preemptible symbol %s"
2412 " cannot be used when making a shared object"),
2413 object
->name().c_str(), gsym
->name());
2414 // We need a GOT section.
2415 target
->got_section(symtab
, layout
);
2418 case elfcpp::R_386_GOTPC
:
2419 // We need a GOT section.
2420 target
->got_section(symtab
, layout
);
2423 // These are relocations which should only be seen by the
2424 // dynamic linker, and should never be seen here.
2425 case elfcpp::R_386_COPY
:
2426 case elfcpp::R_386_GLOB_DAT
:
2427 case elfcpp::R_386_JUMP_SLOT
:
2428 case elfcpp::R_386_RELATIVE
:
2429 case elfcpp::R_386_IRELATIVE
:
2430 case elfcpp::R_386_TLS_TPOFF
:
2431 case elfcpp::R_386_TLS_DTPMOD32
:
2432 case elfcpp::R_386_TLS_DTPOFF32
:
2433 case elfcpp::R_386_TLS_TPOFF32
:
2434 case elfcpp::R_386_TLS_DESC
:
2435 gold_error(_("%s: unexpected reloc %u in object file"),
2436 object
->name().c_str(), r_type
);
2439 // These are initial tls relocs, which are expected when
2441 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2442 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2443 case elfcpp::R_386_TLS_DESC_CALL
:
2444 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2445 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2446 case elfcpp::R_386_TLS_IE
: // Initial-exec
2447 case elfcpp::R_386_TLS_IE_32
:
2448 case elfcpp::R_386_TLS_GOTIE
:
2449 case elfcpp::R_386_TLS_LE
: // Local-exec
2450 case elfcpp::R_386_TLS_LE_32
:
2452 const bool is_final
= gsym
->final_value_is_known();
2453 const tls::Tls_optimization optimized_type
2454 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
2457 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2458 if (optimized_type
== tls::TLSOPT_NONE
)
2460 // Create a pair of GOT entries for the module index and
2461 // dtv-relative offset.
2462 Output_data_got
<32, false>* got
2463 = target
->got_section(symtab
, layout
);
2464 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_PAIR
,
2465 target
->rel_dyn_section(layout
),
2466 elfcpp::R_386_TLS_DTPMOD32
,
2467 elfcpp::R_386_TLS_DTPOFF32
);
2469 else if (optimized_type
== tls::TLSOPT_TO_IE
)
2471 // Create a GOT entry for the tp-relative offset.
2472 Output_data_got
<32, false>* got
2473 = target
->got_section(symtab
, layout
);
2474 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
2475 target
->rel_dyn_section(layout
),
2476 elfcpp::R_386_TLS_TPOFF
);
2478 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2479 unsupported_reloc_global(object
, r_type
, gsym
);
2482 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (~oliva url)
2483 target
->define_tls_base_symbol(symtab
, layout
);
2484 if (optimized_type
== tls::TLSOPT_NONE
)
2486 // Create a double GOT entry with an R_386_TLS_DESC
2487 // reloc. The R_386_TLS_DESC reloc is resolved
2488 // lazily, so the GOT entry needs to be in an area in
2489 // .got.plt, not .got. Call got_section to make sure
2490 // the section has been created.
2491 target
->got_section(symtab
, layout
);
2492 Output_data_got
<32, false>* got
= target
->got_tlsdesc_section();
2493 Reloc_section
* rt
= target
->rel_tls_desc_section(layout
);
2494 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_DESC
, rt
,
2495 elfcpp::R_386_TLS_DESC
, 0);
2497 else if (optimized_type
== tls::TLSOPT_TO_IE
)
2499 // Create a GOT entry for the tp-relative offset.
2500 Output_data_got
<32, false>* got
2501 = target
->got_section(symtab
, layout
);
2502 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
2503 target
->rel_dyn_section(layout
),
2504 elfcpp::R_386_TLS_TPOFF
);
2506 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2507 unsupported_reloc_global(object
, r_type
, gsym
);
2510 case elfcpp::R_386_TLS_DESC_CALL
:
2513 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2514 if (optimized_type
== tls::TLSOPT_NONE
)
2516 // Create a GOT entry for the module index.
2517 target
->got_mod_index_entry(symtab
, layout
, object
);
2519 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2520 unsupported_reloc_global(object
, r_type
, gsym
);
2523 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2526 case elfcpp::R_386_TLS_IE
: // Initial-exec
2527 case elfcpp::R_386_TLS_IE_32
:
2528 case elfcpp::R_386_TLS_GOTIE
:
2529 layout
->set_has_static_tls();
2530 if (optimized_type
== tls::TLSOPT_NONE
)
2532 // For the R_386_TLS_IE relocation, we need to create a
2533 // dynamic relocation when building a shared library.
2534 if (r_type
== elfcpp::R_386_TLS_IE
2535 && parameters
->options().shared())
2537 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2538 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
2539 output_section
, object
,
2541 reloc
.get_r_offset());
2543 // Create a GOT entry for the tp-relative offset.
2544 Output_data_got
<32, false>* got
2545 = target
->got_section(symtab
, layout
);
2546 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2547 ? elfcpp::R_386_TLS_TPOFF32
2548 : elfcpp::R_386_TLS_TPOFF
);
2549 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2550 ? GOT_TYPE_TLS_OFFSET
2551 : GOT_TYPE_TLS_NOFFSET
);
2552 got
->add_global_with_rel(gsym
, got_type
,
2553 target
->rel_dyn_section(layout
),
2556 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2557 unsupported_reloc_global(object
, r_type
, gsym
);
2560 case elfcpp::R_386_TLS_LE
: // Local-exec
2561 case elfcpp::R_386_TLS_LE_32
:
2562 layout
->set_has_static_tls();
2563 if (parameters
->options().shared())
2565 // We need to create a dynamic relocation.
2566 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
2567 ? elfcpp::R_386_TLS_TPOFF32
2568 : elfcpp::R_386_TLS_TPOFF
);
2569 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2570 rel_dyn
->add_global(gsym
, dyn_r_type
, output_section
, object
,
2571 data_shndx
, reloc
.get_r_offset());
2581 case elfcpp::R_386_32PLT
:
2582 case elfcpp::R_386_TLS_GD_32
:
2583 case elfcpp::R_386_TLS_GD_PUSH
:
2584 case elfcpp::R_386_TLS_GD_CALL
:
2585 case elfcpp::R_386_TLS_GD_POP
:
2586 case elfcpp::R_386_TLS_LDM_32
:
2587 case elfcpp::R_386_TLS_LDM_PUSH
:
2588 case elfcpp::R_386_TLS_LDM_CALL
:
2589 case elfcpp::R_386_TLS_LDM_POP
:
2590 case elfcpp::R_386_USED_BY_INTEL_200
:
2592 unsupported_reloc_global(object
, r_type
, gsym
);
2597 // Process relocations for gc.
2600 Target_i386::gc_process_relocs(Symbol_table
* symtab
,
2602 Sized_relobj_file
<32, false>* object
,
2603 unsigned int data_shndx
,
2605 const unsigned char* prelocs
,
2607 Output_section
* output_section
,
2608 bool needs_special_offset_handling
,
2609 size_t local_symbol_count
,
2610 const unsigned char* plocal_symbols
)
2612 gold::gc_process_relocs
<32, false, Target_i386
, Scan
, Classify_reloc
>(
2621 needs_special_offset_handling
,
2626 // Scan relocations for a section.
2629 Target_i386::scan_relocs(Symbol_table
* symtab
,
2631 Sized_relobj_file
<32, false>* object
,
2632 unsigned int data_shndx
,
2633 unsigned int sh_type
,
2634 const unsigned char* prelocs
,
2636 Output_section
* output_section
,
2637 bool needs_special_offset_handling
,
2638 size_t local_symbol_count
,
2639 const unsigned char* plocal_symbols
)
2641 if (sh_type
== elfcpp::SHT_RELA
)
2643 gold_error(_("%s: unsupported RELA reloc section"),
2644 object
->name().c_str());
2648 gold::scan_relocs
<32, false, Target_i386
, Scan
, Classify_reloc
>(
2657 needs_special_offset_handling
,
2662 // Finalize the sections.
2665 Target_i386::do_finalize_sections(
2667 const Input_objects
*,
2668 Symbol_table
* symtab
)
2670 const Reloc_section
* rel_plt
= (this->plt_
== NULL
2672 : this->plt_
->rel_plt());
2673 layout
->add_target_dynamic_tags(true, this->got_plt_
, rel_plt
,
2674 this->rel_dyn_
, true, false);
2676 // Emit any relocs we saved in an attempt to avoid generating COPY
2678 if (this->copy_relocs_
.any_saved_relocs())
2679 this->copy_relocs_
.emit(this->rel_dyn_section(layout
));
2681 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
2682 // the .got.plt section.
2683 Symbol
* sym
= this->global_offset_table_
;
2686 uint32_t data_size
= this->got_plt_
->current_data_size();
2687 symtab
->get_sized_symbol
<32>(sym
)->set_symsize(data_size
);
2690 if (parameters
->doing_static_link()
2691 && (this->plt_
== NULL
|| !this->plt_
->has_irelative_section()))
2693 // If linking statically, make sure that the __rel_iplt symbols
2694 // were defined if necessary, even if we didn't create a PLT.
2695 static const Define_symbol_in_segment syms
[] =
2698 "__rel_iplt_start", // name
2699 elfcpp::PT_LOAD
, // segment_type
2700 elfcpp::PF_W
, // segment_flags_set
2701 elfcpp::PF(0), // segment_flags_clear
2704 elfcpp::STT_NOTYPE
, // type
2705 elfcpp::STB_GLOBAL
, // binding
2706 elfcpp::STV_HIDDEN
, // visibility
2708 Symbol::SEGMENT_START
, // offset_from_base
2712 "__rel_iplt_end", // name
2713 elfcpp::PT_LOAD
, // segment_type
2714 elfcpp::PF_W
, // segment_flags_set
2715 elfcpp::PF(0), // segment_flags_clear
2718 elfcpp::STT_NOTYPE
, // type
2719 elfcpp::STB_GLOBAL
, // binding
2720 elfcpp::STV_HIDDEN
, // visibility
2722 Symbol::SEGMENT_START
, // offset_from_base
2727 symtab
->define_symbols(layout
, 2, syms
,
2728 layout
->script_options()->saw_sections_clause());
2732 // Return whether a direct absolute static relocation needs to be applied.
2733 // In cases where Scan::local() or Scan::global() has created
2734 // a dynamic relocation other than R_386_RELATIVE, the addend
2735 // of the relocation is carried in the data, and we must not
2736 // apply the static relocation.
2739 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
2740 unsigned int r_type
,
2742 Output_section
* output_section
)
2744 // If the output section is not allocated, then we didn't call
2745 // scan_relocs, we didn't create a dynamic reloc, and we must apply
2747 if ((output_section
->flags() & elfcpp::SHF_ALLOC
) == 0)
2750 int ref_flags
= Scan::get_reference_flags(r_type
);
2752 // For local symbols, we will have created a non-RELATIVE dynamic
2753 // relocation only if (a) the output is position independent,
2754 // (b) the relocation is absolute (not pc- or segment-relative), and
2755 // (c) the relocation is not 32 bits wide.
2757 return !(parameters
->options().output_is_position_independent()
2758 && (ref_flags
& Symbol::ABSOLUTE_REF
)
2761 // For global symbols, we use the same helper routines used in the
2762 // scan pass. If we did not create a dynamic relocation, or if we
2763 // created a RELATIVE dynamic relocation, we should apply the static
2765 bool has_dyn
= gsym
->needs_dynamic_reloc(ref_flags
);
2766 bool is_rel
= (ref_flags
& Symbol::ABSOLUTE_REF
)
2767 && gsym
->can_use_relative_reloc(ref_flags
2768 & Symbol::FUNCTION_CALL
);
2769 return !has_dyn
|| is_rel
;
2772 // Perform a relocation.
2775 Target_i386::Relocate::relocate(const Relocate_info
<32, false>* relinfo
,
2777 Target_i386
* target
,
2778 Output_section
* output_section
,
2780 const unsigned char* preloc
,
2781 const Sized_symbol
<32>* gsym
,
2782 const Symbol_value
<32>* psymval
,
2783 unsigned char* view
,
2784 elfcpp::Elf_types
<32>::Elf_Addr address
,
2785 section_size_type view_size
)
2787 const elfcpp::Rel
<32, false> rel(preloc
);
2788 unsigned int r_type
= elfcpp::elf_r_type
<32>(rel
.get_r_info());
2790 if (this->skip_call_tls_get_addr_
)
2792 if ((r_type
!= elfcpp::R_386_PLT32
2793 && r_type
!= elfcpp::R_386_GOT32X
2794 && r_type
!= elfcpp::R_386_PC32
)
2796 || strcmp(gsym
->name(), "___tls_get_addr") != 0)
2797 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2798 _("missing expected TLS relocation"));
2801 this->skip_call_tls_get_addr_
= false;
2809 const Sized_relobj_file
<32, false>* object
= relinfo
->object
;
2811 // Pick the value to use for symbols defined in shared objects.
2812 Symbol_value
<32> symval
;
2814 && gsym
->type() == elfcpp::STT_GNU_IFUNC
2815 && r_type
== elfcpp::R_386_32
2816 && gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
))
2817 && gsym
->can_use_relative_reloc(false)
2818 && !gsym
->is_from_dynobj()
2819 && !gsym
->is_undefined()
2820 && !gsym
->is_preemptible())
2822 // In this case we are generating a R_386_IRELATIVE reloc. We
2823 // want to use the real value of the symbol, not the PLT offset.
2825 else if (gsym
!= NULL
2826 && gsym
->use_plt_offset(Scan::get_reference_flags(r_type
)))
2828 symval
.set_output_value(target
->plt_address_for_global(gsym
));
2831 else if (gsym
== NULL
&& psymval
->is_ifunc_symbol())
2833 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2834 if (object
->local_has_plt_offset(r_sym
))
2836 symval
.set_output_value(target
->plt_address_for_local(object
, r_sym
));
2845 case elfcpp::R_386_NONE
:
2846 case elfcpp::R_386_GNU_VTINHERIT
:
2847 case elfcpp::R_386_GNU_VTENTRY
:
2850 case elfcpp::R_386_32
:
2851 if (should_apply_static_reloc(gsym
, r_type
, true, output_section
))
2852 Relocate_functions
<32, false>::rel32(view
, object
, psymval
);
2855 case elfcpp::R_386_PC32
:
2856 if (should_apply_static_reloc(gsym
, r_type
, true, output_section
))
2857 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
2860 case elfcpp::R_386_16
:
2861 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2862 Relocate_functions
<32, false>::rel16(view
, object
, psymval
);
2865 case elfcpp::R_386_PC16
:
2866 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2867 Relocate_functions
<32, false>::pcrel16(view
, object
, psymval
, address
);
2870 case elfcpp::R_386_8
:
2871 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2872 Relocate_functions
<32, false>::rel8(view
, object
, psymval
);
2875 case elfcpp::R_386_PC8
:
2876 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2877 Relocate_functions
<32, false>::pcrel8(view
, object
, psymval
, address
);
2880 case elfcpp::R_386_PLT32
:
2881 gold_assert(gsym
== NULL
2882 || gsym
->has_plt_offset()
2883 || gsym
->final_value_is_known()
2884 || (gsym
->is_defined()
2885 && !gsym
->is_from_dynobj()
2886 && !gsym
->is_preemptible()));
2887 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
2890 case elfcpp::R_386_GOT32
:
2891 case elfcpp::R_386_GOT32X
:
2892 baseless
= (view
[-1] & 0xc7) == 0x5;
2893 // R_386_GOT32 and R_386_GOT32X don't work without base register
2894 // when generating a position-independent output file.
2896 && parameters
->options().output_is_position_independent())
2899 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2900 _("unexpected reloc %u against global symbol %s without base register in object file when generating a position-independent output file"),
2901 r_type
, gsym
->demangled_name().c_str());
2903 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2904 _("unexpected reloc %u against local symbol without base register in object file when generating a position-independent output file"),
2909 // mov foo@GOT(%reg), %reg
2911 // lea foo@GOTOFF(%reg), %reg
2913 if (rel
.get_r_offset() >= 2
2915 && ((gsym
== NULL
&& !psymval
->is_ifunc_symbol())
2917 && Target_i386::can_convert_mov_to_lea(gsym
))))
2920 elfcpp::Elf_types
<32>::Elf_Addr value
;
2921 value
= psymval
->value(object
, 0);
2922 // Don't subtract the .got.plt section address for baseless
2925 value
-= target
->got_plt_section()->address();
2926 Relocate_functions
<32, false>::rel32(view
, value
);
2930 // The GOT pointer points to the end of the GOT section.
2931 // We need to subtract the size of the GOT section to get
2932 // the actual offset to use in the relocation.
2933 unsigned int got_offset
= 0;
2936 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
2937 got_offset
= (gsym
->got_offset(GOT_TYPE_STANDARD
)
2938 - target
->got_size());
2942 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2943 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
2944 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
2945 - target
->got_size());
2947 // Add the .got.plt section address for baseless addressing.
2949 got_offset
+= target
->got_plt_section()->address();
2950 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2954 case elfcpp::R_386_GOTOFF
:
2956 elfcpp::Elf_types
<32>::Elf_Addr value
;
2957 value
= (psymval
->value(object
, 0)
2958 - target
->got_plt_section()->address());
2959 Relocate_functions
<32, false>::rel32(view
, value
);
2963 case elfcpp::R_386_GOTPC
:
2965 elfcpp::Elf_types
<32>::Elf_Addr value
;
2966 value
= target
->got_plt_section()->address();
2967 Relocate_functions
<32, false>::pcrel32(view
, value
, address
);
2971 case elfcpp::R_386_COPY
:
2972 case elfcpp::R_386_GLOB_DAT
:
2973 case elfcpp::R_386_JUMP_SLOT
:
2974 case elfcpp::R_386_RELATIVE
:
2975 case elfcpp::R_386_IRELATIVE
:
2976 // These are outstanding tls relocs, which are unexpected when
2978 case elfcpp::R_386_TLS_TPOFF
:
2979 case elfcpp::R_386_TLS_DTPMOD32
:
2980 case elfcpp::R_386_TLS_DTPOFF32
:
2981 case elfcpp::R_386_TLS_TPOFF32
:
2982 case elfcpp::R_386_TLS_DESC
:
2983 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2984 _("unexpected reloc %u in object file"),
2988 // These are initial tls relocs, which are expected when
2990 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2991 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2992 case elfcpp::R_386_TLS_DESC_CALL
:
2993 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2994 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2995 case elfcpp::R_386_TLS_IE
: // Initial-exec
2996 case elfcpp::R_386_TLS_IE_32
:
2997 case elfcpp::R_386_TLS_GOTIE
:
2998 case elfcpp::R_386_TLS_LE
: // Local-exec
2999 case elfcpp::R_386_TLS_LE_32
:
3000 this->relocate_tls(relinfo
, target
, relnum
, rel
, r_type
, gsym
, psymval
,
3001 view
, address
, view_size
);
3004 case elfcpp::R_386_32PLT
:
3005 case elfcpp::R_386_TLS_GD_32
:
3006 case elfcpp::R_386_TLS_GD_PUSH
:
3007 case elfcpp::R_386_TLS_GD_CALL
:
3008 case elfcpp::R_386_TLS_GD_POP
:
3009 case elfcpp::R_386_TLS_LDM_32
:
3010 case elfcpp::R_386_TLS_LDM_PUSH
:
3011 case elfcpp::R_386_TLS_LDM_CALL
:
3012 case elfcpp::R_386_TLS_LDM_POP
:
3013 case elfcpp::R_386_USED_BY_INTEL_200
:
3015 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3016 _("unsupported reloc %u"),
3024 // Perform a TLS relocation.
3027 Target_i386::Relocate::relocate_tls(const Relocate_info
<32, false>* relinfo
,
3028 Target_i386
* target
,
3030 const elfcpp::Rel
<32, false>& rel
,
3031 unsigned int r_type
,
3032 const Sized_symbol
<32>* gsym
,
3033 const Symbol_value
<32>* psymval
,
3034 unsigned char* view
,
3035 elfcpp::Elf_types
<32>::Elf_Addr
,
3036 section_size_type view_size
)
3038 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
3040 const Sized_relobj_file
<32, false>* object
= relinfo
->object
;
3042 elfcpp::Elf_types
<32>::Elf_Addr value
= psymval
->value(object
, 0);
3044 const bool is_final
= (gsym
== NULL
3045 ? !parameters
->options().shared()
3046 : gsym
->final_value_is_known());
3047 const tls::Tls_optimization optimized_type
3048 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
3051 case elfcpp::R_386_TLS_GD
: // Global-dynamic
3052 if (optimized_type
== tls::TLSOPT_TO_LE
)
3054 if (tls_segment
== NULL
)
3056 gold_assert(parameters
->errors()->error_count() > 0
3057 || issue_undefined_symbol_error(gsym
));
3060 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
3061 rel
, r_type
, value
, view
,
3067 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
3068 ? GOT_TYPE_TLS_NOFFSET
3069 : GOT_TYPE_TLS_PAIR
);
3070 unsigned int got_offset
;
3073 gold_assert(gsym
->has_got_offset(got_type
));
3074 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
3078 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
3079 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
3080 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
3081 - target
->got_size());
3083 if (optimized_type
== tls::TLSOPT_TO_IE
)
3085 this->tls_gd_to_ie(relinfo
, relnum
, rel
, r_type
,
3086 got_offset
, view
, view_size
);
3089 else if (optimized_type
== tls::TLSOPT_NONE
)
3091 // Relocate the field with the offset of the pair of GOT
3093 Relocate_functions
<32, false>::rel32(view
, got_offset
);
3097 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3098 _("unsupported reloc %u"),
3102 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
3103 case elfcpp::R_386_TLS_DESC_CALL
:
3104 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
3105 if (optimized_type
== tls::TLSOPT_TO_LE
)
3107 if (tls_segment
== NULL
)
3109 gold_assert(parameters
->errors()->error_count() > 0
3110 || issue_undefined_symbol_error(gsym
));
3113 this->tls_desc_gd_to_le(relinfo
, relnum
, tls_segment
,
3114 rel
, r_type
, value
, view
,
3120 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
3121 ? GOT_TYPE_TLS_NOFFSET
3122 : GOT_TYPE_TLS_DESC
);
3123 unsigned int got_offset
= 0;
3124 if (r_type
== elfcpp::R_386_TLS_GOTDESC
3125 && optimized_type
== tls::TLSOPT_NONE
)
3127 // We created GOT entries in the .got.tlsdesc portion of
3128 // the .got.plt section, but the offset stored in the
3129 // symbol is the offset within .got.tlsdesc.
3130 got_offset
= (target
->got_size()
3131 + target
->got_plt_section()->data_size());
3135 gold_assert(gsym
->has_got_offset(got_type
));
3136 got_offset
+= gsym
->got_offset(got_type
) - target
->got_size();
3140 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
3141 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
3142 got_offset
+= (object
->local_got_offset(r_sym
, got_type
)
3143 - target
->got_size());
3145 if (optimized_type
== tls::TLSOPT_TO_IE
)
3147 this->tls_desc_gd_to_ie(relinfo
, relnum
, rel
, r_type
,
3148 got_offset
, view
, view_size
);
3151 else if (optimized_type
== tls::TLSOPT_NONE
)
3153 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
3155 // Relocate the field with the offset of the pair of GOT
3157 Relocate_functions
<32, false>::rel32(view
, got_offset
);
3162 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3163 _("unsupported reloc %u"),
3167 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
3168 if (this->local_dynamic_type_
== LOCAL_DYNAMIC_SUN
)
3170 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3171 _("both SUN and GNU model "
3172 "TLS relocations"));
3175 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
3176 if (optimized_type
== tls::TLSOPT_TO_LE
)
3178 if (tls_segment
== NULL
)
3180 gold_assert(parameters
->errors()->error_count() > 0
3181 || issue_undefined_symbol_error(gsym
));
3184 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rel
, r_type
,
3185 value
, view
, view_size
);
3188 else if (optimized_type
== tls::TLSOPT_NONE
)
3190 // Relocate the field with the offset of the GOT entry for
3191 // the module index.
3192 unsigned int got_offset
;
3193 got_offset
= (target
->got_mod_index_entry(NULL
, NULL
, NULL
)
3194 - target
->got_size());
3195 Relocate_functions
<32, false>::rel32(view
, got_offset
);
3198 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3199 _("unsupported reloc %u"),
3203 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
3204 if (optimized_type
== tls::TLSOPT_TO_LE
)
3206 // This reloc can appear in debugging sections, in which
3207 // case we must not convert to local-exec. We decide what
3208 // to do based on whether the section is marked as
3209 // containing executable code. That is what the GNU linker
3211 elfcpp::Shdr
<32, false> shdr(relinfo
->data_shdr
);
3212 if ((shdr
.get_sh_flags() & elfcpp::SHF_EXECINSTR
) != 0)
3214 if (tls_segment
== NULL
)
3216 gold_assert(parameters
->errors()->error_count() > 0
3217 || issue_undefined_symbol_error(gsym
));
3220 value
-= tls_segment
->memsz();
3223 Relocate_functions
<32, false>::rel32(view
, value
);
3226 case elfcpp::R_386_TLS_IE
: // Initial-exec
3227 case elfcpp::R_386_TLS_GOTIE
:
3228 case elfcpp::R_386_TLS_IE_32
:
3229 if (optimized_type
== tls::TLSOPT_TO_LE
)
3231 if (tls_segment
== NULL
)
3233 gold_assert(parameters
->errors()->error_count() > 0
3234 || issue_undefined_symbol_error(gsym
));
3237 Target_i386::Relocate::tls_ie_to_le(relinfo
, relnum
, tls_segment
,
3238 rel
, r_type
, value
, view
,
3242 else if (optimized_type
== tls::TLSOPT_NONE
)
3244 // Relocate the field with the offset of the GOT entry for
3245 // the tp-relative offset of the symbol.
3246 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
3247 ? GOT_TYPE_TLS_OFFSET
3248 : GOT_TYPE_TLS_NOFFSET
);
3249 unsigned int got_offset
;
3252 gold_assert(gsym
->has_got_offset(got_type
));
3253 got_offset
= gsym
->got_offset(got_type
);
3257 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
3258 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
3259 got_offset
= object
->local_got_offset(r_sym
, got_type
);
3261 // For the R_386_TLS_IE relocation, we need to apply the
3262 // absolute address of the GOT entry.
3263 if (r_type
== elfcpp::R_386_TLS_IE
)
3264 got_offset
+= target
->got_plt_section()->address();
3265 // All GOT offsets are relative to the end of the GOT.
3266 got_offset
-= target
->got_size();
3267 Relocate_functions
<32, false>::rel32(view
, got_offset
);
3270 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3271 _("unsupported reloc %u"),
3275 case elfcpp::R_386_TLS_LE
: // Local-exec
3276 // If we're creating a shared library, a dynamic relocation will
3277 // have been created for this location, so do not apply it now.
3278 if (!parameters
->options().shared())
3280 if (tls_segment
== NULL
)
3282 gold_assert(parameters
->errors()->error_count() > 0
3283 || issue_undefined_symbol_error(gsym
));
3286 value
-= tls_segment
->memsz();
3287 Relocate_functions
<32, false>::rel32(view
, value
);
3291 case elfcpp::R_386_TLS_LE_32
:
3292 // If we're creating a shared library, a dynamic relocation will
3293 // have been created for this location, so do not apply it now.
3294 if (!parameters
->options().shared())
3296 if (tls_segment
== NULL
)
3298 gold_assert(parameters
->errors()->error_count() > 0
3299 || issue_undefined_symbol_error(gsym
));
3302 value
= tls_segment
->memsz() - value
;
3303 Relocate_functions
<32, false>::rel32(view
, value
);
3309 // Do a relocation in which we convert a TLS General-Dynamic to a
3313 Target_i386::Relocate::tls_gd_to_le(const Relocate_info
<32, false>* relinfo
,
3315 Output_segment
* tls_segment
,
3316 const elfcpp::Rel
<32, false>& rel
,
3318 elfcpp::Elf_types
<32>::Elf_Addr value
,
3319 unsigned char* view
,
3320 section_size_type view_size
)
3322 // leal foo(,%ebx,1),%eax; call ___tls_get_addr@PLT
3323 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
3324 // leal foo(%ebx),%eax; call ___tls_get_addr@PLT
3325 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
3326 // leal foo(%reg),%eax; call *___tls_get_addr@GOT(%reg)
3327 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
3329 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3330 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
3332 unsigned char op1
= view
[-1];
3333 unsigned char op2
= view
[-2];
3334 unsigned char op3
= view
[4];
3336 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3337 op2
== 0x8d || op2
== 0x04);
3338 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3339 op3
== 0xe8 || op3
== 0xff);
3345 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
3346 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
3347 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3348 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
3349 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3353 unsigned char reg
= op1
& 7;
3354 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3355 ((op1
& 0xf8) == 0x80
3358 && (op3
== 0xe8 || (view
[5] & 0x7) == reg
)));
3360 || (rel
.get_r_offset() + 9 < view_size
3361 && view
[9] == 0x90))
3363 // There is an indirect call or a trailing nop. Use the size
3365 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3370 // Use the five byte subl.
3371 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
3375 value
= tls_segment
->memsz() - value
;
3376 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
3378 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3380 this->skip_call_tls_get_addr_
= true;
3383 // Do a relocation in which we convert a TLS General-Dynamic to an
3387 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info
<32, false>* relinfo
,
3389 const elfcpp::Rel
<32, false>& rel
,
3391 elfcpp::Elf_types
<32>::Elf_Addr value
,
3392 unsigned char* view
,
3393 section_size_type view_size
)
3395 // leal foo(,%ebx,1),%eax; call ___tls_get_addr@PLT
3396 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
3397 // leal foo(%ebx),%eax; call ___tls_get_addr@PLT; nop
3398 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
3399 // leal foo(%reg),%eax; call *___tls_get_addr@GOT(%reg)
3400 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%reg),%eax
3402 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3403 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
3405 unsigned char op1
= view
[-1];
3406 unsigned char op2
= view
[-2];
3407 unsigned char op3
= view
[4];
3409 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3410 op2
== 0x8d || op2
== 0x04);
3411 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3412 op3
== 0xe8 || op3
== 0xff);
3418 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
3419 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
3420 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3421 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
3426 unsigned char reg
= op1
& 7;
3427 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 10);
3428 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3429 ((op1
& 0xf8) == 0x80
3432 && ((op3
== 0xe8 && view
[9] == 0x90)
3433 || (view
[5] & 0x7) == reg
)));
3437 memcpy(view
+ roff
- 8, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
3438 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
3440 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3442 this->skip_call_tls_get_addr_
= true;
3445 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3446 // General-Dynamic to a Local-Exec.
3449 Target_i386::Relocate::tls_desc_gd_to_le(
3450 const Relocate_info
<32, false>* relinfo
,
3452 Output_segment
* tls_segment
,
3453 const elfcpp::Rel
<32, false>& rel
,
3454 unsigned int r_type
,
3455 elfcpp::Elf_types
<32>::Elf_Addr value
,
3456 unsigned char* view
,
3457 section_size_type view_size
)
3459 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
3461 // leal foo@TLSDESC(%ebx), %eax
3462 // ==> leal foo@NTPOFF, %eax
3463 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3464 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3465 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3466 view
[-2] == 0x8d && view
[-1] == 0x83);
3468 value
-= tls_segment
->memsz();
3469 Relocate_functions
<32, false>::rel32(view
, value
);
3473 // call *foo@TLSCALL(%eax)
3475 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
3476 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
3477 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3478 view
[0] == 0xff && view
[1] == 0x10);
3484 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3485 // General-Dynamic to an Initial-Exec.
3488 Target_i386::Relocate::tls_desc_gd_to_ie(
3489 const Relocate_info
<32, false>* relinfo
,
3491 const elfcpp::Rel
<32, false>& rel
,
3492 unsigned int r_type
,
3493 elfcpp::Elf_types
<32>::Elf_Addr value
,
3494 unsigned char* view
,
3495 section_size_type view_size
)
3497 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
3499 // leal foo@TLSDESC(%ebx), %eax
3500 // ==> movl foo@GOTNTPOFF(%ebx), %eax
3501 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3502 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3503 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3504 view
[-2] == 0x8d && view
[-1] == 0x83);
3506 Relocate_functions
<32, false>::rel32(view
, value
);
3510 // call *foo@TLSCALL(%eax)
3512 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
3513 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
3514 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3515 view
[0] == 0xff && view
[1] == 0x10);
3521 // Do a relocation in which we convert a TLS Local-Dynamic to a
3525 Target_i386::Relocate::tls_ld_to_le(const Relocate_info
<32, false>* relinfo
,
3528 const elfcpp::Rel
<32, false>& rel
,
3530 elfcpp::Elf_types
<32>::Elf_Addr
,
3531 unsigned char* view
,
3532 section_size_type view_size
)
3534 // leal foo(%ebx), %eax; call ___tls_get_addr@PLT
3535 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
3536 // leal foo(%reg), %eax; call call *___tls_get_addr@GOT(%reg)
3537 // ==> movl %gs:0,%eax; leal (%esi),%esi
3539 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3541 unsigned char op1
= view
[-1];
3542 unsigned char op2
= view
[-2];
3543 unsigned char op3
= view
[4];
3545 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3546 op3
== 0xe8 || op3
== 0xff);
3547 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
,
3548 op3
== 0xe8 ? 9 : 10);
3550 // FIXME: Does this test really always pass?
3551 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), op2
== 0x8d);
3553 unsigned char reg
= op1
& 7;
3554 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3555 ((op1
& 0xf8) == 0x80
3558 && (op3
== 0xe8 || (view
[5] & 0x7) == reg
)));
3561 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
3563 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x8d\xb6\0\0\0\0", 12);
3565 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3567 this->skip_call_tls_get_addr_
= true;
3570 // Do a relocation in which we convert a TLS Initial-Exec to a
3574 Target_i386::Relocate::tls_ie_to_le(const Relocate_info
<32, false>* relinfo
,
3576 Output_segment
* tls_segment
,
3577 const elfcpp::Rel
<32, false>& rel
,
3578 unsigned int r_type
,
3579 elfcpp::Elf_types
<32>::Elf_Addr value
,
3580 unsigned char* view
,
3581 section_size_type view_size
)
3583 // We have to actually change the instructions, which means that we
3584 // need to examine the opcodes to figure out which instruction we
3586 if (r_type
== elfcpp::R_386_TLS_IE
)
3588 // movl %gs:XX,%eax ==> movl $YY,%eax
3589 // movl %gs:XX,%reg ==> movl $YY,%reg
3590 // addl %gs:XX,%reg ==> addl $YY,%reg
3591 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -1);
3592 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3594 unsigned char op1
= view
[-1];
3597 // movl XX,%eax ==> movl $YY,%eax
3602 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3604 unsigned char op2
= view
[-2];
3607 // movl XX,%reg ==> movl $YY,%reg
3608 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3609 (op1
& 0xc7) == 0x05);
3611 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3613 else if (op2
== 0x03)
3615 // addl XX,%reg ==> addl $YY,%reg
3616 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3617 (op1
& 0xc7) == 0x05);
3619 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3622 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
3627 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
3628 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
3629 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
3630 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3631 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3633 unsigned char op1
= view
[-1];
3634 unsigned char op2
= view
[-2];
3635 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3636 (op1
& 0xc0) == 0x80 && (op1
& 7) != 4);
3639 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
3641 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3643 else if (op2
== 0x2b)
3645 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
3647 view
[-1] = 0xe8 | ((op1
>> 3) & 7);
3649 else if (op2
== 0x03)
3651 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
3653 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3656 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
3659 value
= tls_segment
->memsz() - value
;
3660 if (r_type
== elfcpp::R_386_TLS_IE
|| r_type
== elfcpp::R_386_TLS_GOTIE
)
3663 Relocate_functions
<32, false>::rel32(view
, value
);
3666 // Relocate section data.
3669 Target_i386::relocate_section(const Relocate_info
<32, false>* relinfo
,
3670 unsigned int sh_type
,
3671 const unsigned char* prelocs
,
3673 Output_section
* output_section
,
3674 bool needs_special_offset_handling
,
3675 unsigned char* view
,
3676 elfcpp::Elf_types
<32>::Elf_Addr address
,
3677 section_size_type view_size
,
3678 const Reloc_symbol_changes
* reloc_symbol_changes
)
3680 gold_assert(sh_type
== elfcpp::SHT_REL
);
3682 gold::relocate_section
<32, false, Target_i386
, Relocate
,
3683 gold::Default_comdat_behavior
, Classify_reloc
>(
3689 needs_special_offset_handling
,
3693 reloc_symbol_changes
);
3696 // Return the size of a relocation while scanning during a relocatable
3700 Target_i386::Classify_reloc::get_size_for_reloc(
3701 unsigned int r_type
,
3706 case elfcpp::R_386_NONE
:
3707 case elfcpp::R_386_GNU_VTINHERIT
:
3708 case elfcpp::R_386_GNU_VTENTRY
:
3709 case elfcpp::R_386_TLS_GD
: // Global-dynamic
3710 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
3711 case elfcpp::R_386_TLS_DESC_CALL
:
3712 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
3713 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
3714 case elfcpp::R_386_TLS_IE
: // Initial-exec
3715 case elfcpp::R_386_TLS_IE_32
:
3716 case elfcpp::R_386_TLS_GOTIE
:
3717 case elfcpp::R_386_TLS_LE
: // Local-exec
3718 case elfcpp::R_386_TLS_LE_32
:
3721 case elfcpp::R_386_32
:
3722 case elfcpp::R_386_PC32
:
3723 case elfcpp::R_386_GOT32
:
3724 case elfcpp::R_386_GOT32X
:
3725 case elfcpp::R_386_PLT32
:
3726 case elfcpp::R_386_GOTOFF
:
3727 case elfcpp::R_386_GOTPC
:
3730 case elfcpp::R_386_16
:
3731 case elfcpp::R_386_PC16
:
3734 case elfcpp::R_386_8
:
3735 case elfcpp::R_386_PC8
:
3738 // These are relocations which should only be seen by the
3739 // dynamic linker, and should never be seen here.
3740 case elfcpp::R_386_COPY
:
3741 case elfcpp::R_386_GLOB_DAT
:
3742 case elfcpp::R_386_JUMP_SLOT
:
3743 case elfcpp::R_386_RELATIVE
:
3744 case elfcpp::R_386_IRELATIVE
:
3745 case elfcpp::R_386_TLS_TPOFF
:
3746 case elfcpp::R_386_TLS_DTPMOD32
:
3747 case elfcpp::R_386_TLS_DTPOFF32
:
3748 case elfcpp::R_386_TLS_TPOFF32
:
3749 case elfcpp::R_386_TLS_DESC
:
3750 object
->error(_("unexpected reloc %u in object file"), r_type
);
3753 case elfcpp::R_386_32PLT
:
3754 case elfcpp::R_386_TLS_GD_32
:
3755 case elfcpp::R_386_TLS_GD_PUSH
:
3756 case elfcpp::R_386_TLS_GD_CALL
:
3757 case elfcpp::R_386_TLS_GD_POP
:
3758 case elfcpp::R_386_TLS_LDM_32
:
3759 case elfcpp::R_386_TLS_LDM_PUSH
:
3760 case elfcpp::R_386_TLS_LDM_CALL
:
3761 case elfcpp::R_386_TLS_LDM_POP
:
3762 case elfcpp::R_386_USED_BY_INTEL_200
:
3764 object
->error(_("unsupported reloc %u in object file"), r_type
);
3769 // Scan the relocs during a relocatable link.
3772 Target_i386::scan_relocatable_relocs(Symbol_table
* symtab
,
3774 Sized_relobj_file
<32, false>* object
,
3775 unsigned int data_shndx
,
3776 unsigned int sh_type
,
3777 const unsigned char* prelocs
,
3779 Output_section
* output_section
,
3780 bool needs_special_offset_handling
,
3781 size_t local_symbol_count
,
3782 const unsigned char* plocal_symbols
,
3783 Relocatable_relocs
* rr
)
3785 typedef gold::Default_scan_relocatable_relocs
<Classify_reloc
>
3786 Scan_relocatable_relocs
;
3788 gold_assert(sh_type
== elfcpp::SHT_REL
);
3790 gold::scan_relocatable_relocs
<32, false, Scan_relocatable_relocs
>(
3798 needs_special_offset_handling
,
3804 // Scan the relocs for --emit-relocs.
3807 Target_i386::emit_relocs_scan(Symbol_table
* symtab
,
3809 Sized_relobj_file
<32, false>* object
,
3810 unsigned int data_shndx
,
3811 unsigned int sh_type
,
3812 const unsigned char* prelocs
,
3814 Output_section
* output_section
,
3815 bool needs_special_offset_handling
,
3816 size_t local_symbol_count
,
3817 const unsigned char* plocal_syms
,
3818 Relocatable_relocs
* rr
)
3820 typedef gold::Default_classify_reloc
<elfcpp::SHT_REL
, 32, false>
3822 typedef gold::Default_emit_relocs_strategy
<Classify_reloc
>
3823 Emit_relocs_strategy
;
3825 gold_assert(sh_type
== elfcpp::SHT_REL
);
3827 gold::scan_relocatable_relocs
<32, false, Emit_relocs_strategy
>(
3835 needs_special_offset_handling
,
3841 // Emit relocations for a section.
3844 Target_i386::relocate_relocs(
3845 const Relocate_info
<32, false>* relinfo
,
3846 unsigned int sh_type
,
3847 const unsigned char* prelocs
,
3849 Output_section
* output_section
,
3850 elfcpp::Elf_types
<32>::Elf_Off offset_in_output_section
,
3851 unsigned char* view
,
3852 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
3853 section_size_type view_size
,
3854 unsigned char* reloc_view
,
3855 section_size_type reloc_view_size
)
3857 gold_assert(sh_type
== elfcpp::SHT_REL
);
3859 gold::relocate_relocs
<32, false, Classify_reloc
>(
3864 offset_in_output_section
,
3872 // Return the value to use for a dynamic which requires special
3873 // treatment. This is how we support equality comparisons of function
3874 // pointers across shared library boundaries, as described in the
3875 // processor specific ABI supplement.
3878 Target_i386::do_dynsym_value(const Symbol
* gsym
) const
3880 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
3881 return this->plt_address_for_global(gsym
);
3884 // Return a string used to fill a code section with nops to take up
3885 // the specified length.
3888 Target_i386::do_code_fill(section_size_type length
) const
3892 // Build a jmp instruction to skip over the bytes.
3893 unsigned char jmp
[5];
3895 elfcpp::Swap_unaligned
<32, false>::writeval(jmp
+ 1, length
- 5);
3896 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
3897 + std::string(length
- 5, static_cast<char>(0x90)));
3900 // Nop sequences of various lengths.
3901 const char nop1
[1] = { '\x90' }; // nop
3902 const char nop2
[2] = { '\x66', '\x90' }; // xchg %ax %ax
3903 const char nop3
[3] = { '\x8d', '\x76', '\x00' }; // leal 0(%esi),%esi
3904 const char nop4
[4] = { '\x8d', '\x74', '\x26', // leal 0(%esi,1),%esi
3906 const char nop5
[5] = { '\x90', '\x8d', '\x74', // nop
3907 '\x26', '\x00' }; // leal 0(%esi,1),%esi
3908 const char nop6
[6] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3909 '\x00', '\x00', '\x00' };
3910 const char nop7
[7] = { '\x8d', '\xb4', '\x26', // leal 0L(%esi,1),%esi
3911 '\x00', '\x00', '\x00',
3913 const char nop8
[8] = { '\x90', '\x8d', '\xb4', // nop
3914 '\x26', '\x00', '\x00', // leal 0L(%esi,1),%esi
3916 const char nop9
[9] = { '\x89', '\xf6', '\x8d', // movl %esi,%esi
3917 '\xbc', '\x27', '\x00', // leal 0L(%edi,1),%edi
3918 '\x00', '\x00', '\x00' };
3919 const char nop10
[10] = { '\x8d', '\x76', '\x00', // leal 0(%esi),%esi
3920 '\x8d', '\xbc', '\x27', // leal 0L(%edi,1),%edi
3921 '\x00', '\x00', '\x00',
3923 const char nop11
[11] = { '\x8d', '\x74', '\x26', // leal 0(%esi,1),%esi
3924 '\x00', '\x8d', '\xbc', // leal 0L(%edi,1),%edi
3925 '\x27', '\x00', '\x00',
3927 const char nop12
[12] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3928 '\x00', '\x00', '\x00', // leal 0L(%edi),%edi
3929 '\x8d', '\xbf', '\x00',
3930 '\x00', '\x00', '\x00' };
3931 const char nop13
[13] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3932 '\x00', '\x00', '\x00', // leal 0L(%edi,1),%edi
3933 '\x8d', '\xbc', '\x27',
3934 '\x00', '\x00', '\x00',
3936 const char nop14
[14] = { '\x8d', '\xb4', '\x26', // leal 0L(%esi,1),%esi
3937 '\x00', '\x00', '\x00', // leal 0L(%edi,1),%edi
3938 '\x00', '\x8d', '\xbc',
3939 '\x27', '\x00', '\x00',
3941 const char nop15
[15] = { '\xeb', '\x0d', '\x90', // jmp .+15
3942 '\x90', '\x90', '\x90', // nop,nop,nop,...
3943 '\x90', '\x90', '\x90',
3944 '\x90', '\x90', '\x90',
3945 '\x90', '\x90', '\x90' };
3947 const char* nops
[16] = {
3949 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
3950 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
3953 return std::string(nops
[length
], length
);
3956 // Return the value to use for the base of a DW_EH_PE_datarel offset
3957 // in an FDE. Solaris and SVR4 use DW_EH_PE_datarel because their
3958 // assembler can not write out the difference between two labels in
3959 // different sections, so instead of using a pc-relative value they
3960 // use an offset from the GOT.
3963 Target_i386::do_ehframe_datarel_base() const
3965 gold_assert(this->global_offset_table_
!= NULL
);
3966 Symbol
* sym
= this->global_offset_table_
;
3967 Sized_symbol
<32>* ssym
= static_cast<Sized_symbol
<32>*>(sym
);
3968 return ssym
->value();
3971 // Return whether SYM should be treated as a call to a non-split
3972 // function. We don't want that to be true of a call to a
3973 // get_pc_thunk function.
3976 Target_i386::do_is_call_to_non_split(const Symbol
* sym
,
3977 const unsigned char*,
3978 const unsigned char*,
3979 section_size_type
) const
3981 return (sym
->type() == elfcpp::STT_FUNC
3982 && !is_prefix_of("__i686.get_pc_thunk.", sym
->name()));
3985 // FNOFFSET in section SHNDX in OBJECT is the start of a function
3986 // compiled with -fsplit-stack. The function calls non-split-stack
3987 // code. We have to change the function so that it always ensures
3988 // that it has enough stack space to run some random function.
3991 Target_i386::do_calls_non_split(Relobj
* object
, unsigned int shndx
,
3992 section_offset_type fnoffset
,
3993 section_size_type fnsize
,
3994 const unsigned char*,
3996 unsigned char* view
,
3997 section_size_type view_size
,
3999 std::string
* to
) const
4001 // The function starts with a comparison of the stack pointer and a
4002 // field in the TCB. This is followed by a jump.
4005 if (this->match_view(view
, view_size
, fnoffset
, "\x65\x3b\x25", 3)
4008 // We will call __morestack if the carry flag is set after this
4009 // comparison. We turn the comparison into an stc instruction
4011 view
[fnoffset
] = '\xf9';
4012 this->set_view_to_nop(view
, view_size
, fnoffset
+ 1, 6);
4014 // lea NN(%esp),%ecx
4015 // lea NN(%esp),%edx
4016 else if ((this->match_view(view
, view_size
, fnoffset
, "\x8d\x8c\x24", 3)
4017 || this->match_view(view
, view_size
, fnoffset
, "\x8d\x94\x24", 3))
4020 // This is loading an offset from the stack pointer for a
4021 // comparison. The offset is negative, so we decrease the
4022 // offset by the amount of space we need for the stack. This
4023 // means we will avoid calling __morestack if there happens to
4024 // be plenty of space on the stack already.
4025 unsigned char* pval
= view
+ fnoffset
+ 3;
4026 uint32_t val
= elfcpp::Swap_unaligned
<32, false>::readval(pval
);
4027 val
-= parameters
->options().split_stack_adjust_size();
4028 elfcpp::Swap_unaligned
<32, false>::writeval(pval
, val
);
4032 if (!object
->has_no_split_stack())
4033 object
->error(_("failed to match split-stack sequence at "
4034 "section %u offset %0zx"),
4035 shndx
, static_cast<size_t>(fnoffset
));
4039 // We have to change the function so that it calls
4040 // __morestack_non_split instead of __morestack. The former will
4041 // allocate additional stack space.
4042 *from
= "__morestack";
4043 *to
= "__morestack_non_split";
4046 // The selector for i386 object files. Note this is never instantiated
4047 // directly. It's only used in Target_selector_i386_nacl, below.
4049 class Target_selector_i386
: public Target_selector_freebsd
4052 Target_selector_i386()
4053 : Target_selector_freebsd(elfcpp::EM_386
, 32, false,
4054 "elf32-i386", "elf32-i386-freebsd",
4059 do_instantiate_target()
4060 { return new Target_i386(); }
4063 // NaCl variant. It uses different PLT contents.
4065 class Output_data_plt_i386_nacl
: public Output_data_plt_i386
4068 Output_data_plt_i386_nacl(Layout
* layout
,
4069 Output_data_got_plt_i386
* got_plt
,
4070 Output_data_space
* got_irelative
)
4071 : Output_data_plt_i386(layout
, plt_entry_size
, got_plt
, got_irelative
)
4075 virtual unsigned int
4076 do_get_plt_entry_size() const
4077 { return plt_entry_size
; }
4080 do_add_eh_frame(Layout
* layout
)
4082 layout
->add_eh_frame_for_plt(this, plt_eh_frame_cie
, plt_eh_frame_cie_size
,
4083 plt_eh_frame_fde
, plt_eh_frame_fde_size
);
4086 // The size of an entry in the PLT.
4087 static const int plt_entry_size
= 64;
4089 // The .eh_frame unwind information for the PLT.
4090 static const int plt_eh_frame_fde_size
= 32;
4091 static const unsigned char plt_eh_frame_fde
[plt_eh_frame_fde_size
];
4094 class Output_data_plt_i386_nacl_exec
: public Output_data_plt_i386_nacl
4097 Output_data_plt_i386_nacl_exec(Layout
* layout
,
4098 Output_data_got_plt_i386
* got_plt
,
4099 Output_data_space
* got_irelative
)
4100 : Output_data_plt_i386_nacl(layout
, got_plt
, got_irelative
)
4105 do_fill_first_plt_entry(unsigned char* pov
,
4106 elfcpp::Elf_types
<32>::Elf_Addr got_address
);
4108 virtual unsigned int
4109 do_fill_plt_entry(unsigned char* pov
,
4110 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
4111 unsigned int got_offset
,
4112 unsigned int plt_offset
,
4113 unsigned int plt_rel_offset
);
4116 // The first entry in the PLT for an executable.
4117 static const unsigned char first_plt_entry
[plt_entry_size
];
4119 // Other entries in the PLT for an executable.
4120 static const unsigned char plt_entry
[plt_entry_size
];
4123 class Output_data_plt_i386_nacl_dyn
: public Output_data_plt_i386_nacl
4126 Output_data_plt_i386_nacl_dyn(Layout
* layout
,
4127 Output_data_got_plt_i386
* got_plt
,
4128 Output_data_space
* got_irelative
)
4129 : Output_data_plt_i386_nacl(layout
, got_plt
, got_irelative
)
4134 do_fill_first_plt_entry(unsigned char* pov
, elfcpp::Elf_types
<32>::Elf_Addr
);
4136 virtual unsigned int
4137 do_fill_plt_entry(unsigned char* pov
,
4138 elfcpp::Elf_types
<32>::Elf_Addr
,
4139 unsigned int got_offset
,
4140 unsigned int plt_offset
,
4141 unsigned int plt_rel_offset
);
4144 // The first entry in the PLT for a shared object.
4145 static const unsigned char first_plt_entry
[plt_entry_size
];
4147 // Other entries in the PLT for a shared object.
4148 static const unsigned char plt_entry
[plt_entry_size
];
4151 class Target_i386_nacl
: public Target_i386
4155 : Target_i386(&i386_nacl_info
)
4159 virtual Output_data_plt_i386
*
4160 do_make_data_plt(Layout
* layout
,
4161 Output_data_got_plt_i386
* got_plt
,
4162 Output_data_space
* got_irelative
,
4166 return new Output_data_plt_i386_nacl_dyn(layout
, got_plt
, got_irelative
);
4168 return new Output_data_plt_i386_nacl_exec(layout
, got_plt
, got_irelative
);
4172 do_code_fill(section_size_type length
) const;
4175 static const Target::Target_info i386_nacl_info
;
4178 const Target::Target_info
Target_i386_nacl::i386_nacl_info
=
4181 false, // is_big_endian
4182 elfcpp::EM_386
, // machine_code
4183 false, // has_make_symbol
4184 false, // has_resolve
4185 true, // has_code_fill
4186 true, // is_default_stack_executable
4187 true, // can_icf_inline_merge_sections
4189 "/lib/ld-nacl-x86-32.so.1", // dynamic_linker
4190 0x20000, // default_text_segment_address
4191 0x10000, // abi_pagesize (overridable by -z max-page-size)
4192 0x10000, // common_pagesize (overridable by -z common-page-size)
4193 true, // isolate_execinstr
4194 0x10000000, // rosegment_gap
4195 elfcpp::SHN_UNDEF
, // small_common_shndx
4196 elfcpp::SHN_UNDEF
, // large_common_shndx
4197 0, // small_common_section_flags
4198 0, // large_common_section_flags
4199 NULL
, // attributes_section
4200 NULL
, // attributes_vendor
4201 "_start", // entry_symbol_name
4202 32, // hash_entry_size
4205 #define NACLMASK 0xe0 // 32-byte alignment mask
4208 Output_data_plt_i386_nacl_exec::first_plt_entry
[plt_entry_size
] =
4210 0xff, 0x35, // pushl contents of memory address
4211 0, 0, 0, 0, // replaced with address of .got + 4
4212 0x8b, 0x0d, // movl contents of address, %ecx
4213 0, 0, 0, 0, // replaced with address of .got + 8
4214 0x83, 0xe1, NACLMASK
, // andl $NACLMASK, %ecx
4215 0xff, 0xe1, // jmp *%ecx
4216 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4217 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4218 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4219 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4220 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4221 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4222 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4223 0x90, 0x90, 0x90, 0x90, 0x90
4227 Output_data_plt_i386_nacl_exec::do_fill_first_plt_entry(
4229 elfcpp::Elf_types
<32>::Elf_Addr got_address
)
4231 memcpy(pov
, first_plt_entry
, plt_entry_size
);
4232 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 4);
4233 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 8);
4236 // The first entry in the PLT for a shared object.
4239 Output_data_plt_i386_nacl_dyn::first_plt_entry
[plt_entry_size
] =
4241 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
4242 0x8b, 0x4b, 0x08, // mov 0x8(%ebx), %ecx
4243 0x83, 0xe1, NACLMASK
, // andl $NACLMASK, %ecx
4244 0xff, 0xe1, // jmp *%ecx
4245 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4246 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4247 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4248 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4249 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4250 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4251 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4252 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4253 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4254 0x90, 0x90, 0x90, 0x90, 0x90 // nops
4258 Output_data_plt_i386_nacl_dyn::do_fill_first_plt_entry(
4260 elfcpp::Elf_types
<32>::Elf_Addr
)
4262 memcpy(pov
, first_plt_entry
, plt_entry_size
);
4265 // Subsequent entries in the PLT for an executable.
4268 Output_data_plt_i386_nacl_exec::plt_entry
[plt_entry_size
] =
4270 0x8b, 0x0d, // movl contents of address, %ecx */
4271 0, 0, 0, 0, // replaced with address of symbol in .got
4272 0x83, 0xe1, NACLMASK
, // andl $NACLMASK, %ecx
4273 0xff, 0xe1, // jmp *%ecx
4275 // Pad to the next 32-byte boundary with nop instructions.
4277 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4278 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4280 // Lazy GOT entries point here (32-byte aligned).
4281 0x68, // pushl immediate
4282 0, 0, 0, 0, // replaced with offset into relocation table
4283 0xe9, // jmp relative
4284 0, 0, 0, 0, // replaced with offset to start of .plt
4286 // Pad to the next 32-byte boundary with nop instructions.
4287 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4288 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4293 Output_data_plt_i386_nacl_exec::do_fill_plt_entry(
4295 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
4296 unsigned int got_offset
,
4297 unsigned int plt_offset
,
4298 unsigned int plt_rel_offset
)
4300 memcpy(pov
, plt_entry
, plt_entry_size
);
4301 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
4302 got_address
+ got_offset
);
4303 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 33, plt_rel_offset
);
4304 elfcpp::Swap
<32, false>::writeval(pov
+ 38, - (plt_offset
+ 38 + 4));
4308 // Subsequent entries in the PLT for a shared object.
4311 Output_data_plt_i386_nacl_dyn::plt_entry
[plt_entry_size
] =
4313 0x8b, 0x8b, // movl offset(%ebx), %ecx
4314 0, 0, 0, 0, // replaced with offset of symbol in .got
4315 0x83, 0xe1, 0xe0, // andl $NACLMASK, %ecx
4316 0xff, 0xe1, // jmp *%ecx
4318 // Pad to the next 32-byte boundary with nop instructions.
4320 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4321 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4323 // Lazy GOT entries point here (32-byte aligned).
4324 0x68, // pushl immediate
4325 0, 0, 0, 0, // replaced with offset into relocation table.
4326 0xe9, // jmp relative
4327 0, 0, 0, 0, // replaced with offset to start of .plt.
4329 // Pad to the next 32-byte boundary with nop instructions.
4330 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4331 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4336 Output_data_plt_i386_nacl_dyn::do_fill_plt_entry(
4338 elfcpp::Elf_types
<32>::Elf_Addr
,
4339 unsigned int got_offset
,
4340 unsigned int plt_offset
,
4341 unsigned int plt_rel_offset
)
4343 memcpy(pov
, plt_entry
, plt_entry_size
);
4344 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
4345 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 33, plt_rel_offset
);
4346 elfcpp::Swap
<32, false>::writeval(pov
+ 38, - (plt_offset
+ 38 + 4));
4351 Output_data_plt_i386_nacl::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
4353 0, 0, 0, 0, // Replaced with offset to .plt.
4354 0, 0, 0, 0, // Replaced with size of .plt.
4355 0, // Augmentation size.
4356 elfcpp::DW_CFA_def_cfa_offset
, 8, // DW_CFA_def_cfa_offset: 8.
4357 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
4358 elfcpp::DW_CFA_def_cfa_offset
, 12, // DW_CFA_def_cfa_offset: 12.
4359 elfcpp::DW_CFA_advance_loc
+ 58, // Advance 58 to __PLT__ + 64.
4360 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
4361 13, // Block length.
4362 elfcpp::DW_OP_breg4
, 4, // Push %esp + 4.
4363 elfcpp::DW_OP_breg8
, 0, // Push %eip.
4364 elfcpp::DW_OP_const1u
, 63, // Push 0x3f.
4365 elfcpp::DW_OP_and
, // & (%eip & 0x3f).
4366 elfcpp::DW_OP_const1u
, 37, // Push 0x25.
4367 elfcpp::DW_OP_ge
, // >= ((%eip & 0x3f) >= 0x25)
4368 elfcpp::DW_OP_lit2
, // Push 2.
4369 elfcpp::DW_OP_shl
, // << (((%eip & 0x3f) >= 0x25) << 2)
4370 elfcpp::DW_OP_plus
, // + ((((%eip&0x3f)>=0x25)<<2)+%esp+4
4371 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
4375 // Return a string used to fill a code section with nops.
4376 // For NaCl, long NOPs are only valid if they do not cross
4377 // bundle alignment boundaries, so keep it simple with one-byte NOPs.
4379 Target_i386_nacl::do_code_fill(section_size_type length
) const
4381 return std::string(length
, static_cast<char>(0x90));
4384 // The selector for i386-nacl object files.
4386 class Target_selector_i386_nacl
4387 : public Target_selector_nacl
<Target_selector_i386
, Target_i386_nacl
>
4390 Target_selector_i386_nacl()
4391 : Target_selector_nacl
<Target_selector_i386
,
4392 Target_i386_nacl
>("x86-32",
4398 Target_selector_i386_nacl target_selector_i386
;
4400 // IAMCU variant. It uses EM_IAMCU, not EM_386.
4402 class Target_iamcu
: public Target_i386
4406 : Target_i386(&iamcu_info
)
4410 // Information about this specific target which we pass to the
4411 // general Target structure.
4412 static const Target::Target_info iamcu_info
;
4415 const Target::Target_info
Target_iamcu::iamcu_info
=
4418 false, // is_big_endian
4419 elfcpp::EM_IAMCU
, // machine_code
4420 false, // has_make_symbol
4421 false, // has_resolve
4422 true, // has_code_fill
4423 true, // is_default_stack_executable
4424 true, // can_icf_inline_merge_sections
4426 "/usr/lib/libc.so.1", // dynamic_linker
4427 0x08048000, // default_text_segment_address
4428 0x1000, // abi_pagesize (overridable by -z max-page-size)
4429 0x1000, // common_pagesize (overridable by -z common-page-size)
4430 false, // isolate_execinstr
4432 elfcpp::SHN_UNDEF
, // small_common_shndx
4433 elfcpp::SHN_UNDEF
, // large_common_shndx
4434 0, // small_common_section_flags
4435 0, // large_common_section_flags
4436 NULL
, // attributes_section
4437 NULL
, // attributes_vendor
4438 "_start", // entry_symbol_name
4439 32, // hash_entry_size
4442 class Target_selector_iamcu
: public Target_selector
4445 Target_selector_iamcu()
4446 : Target_selector(elfcpp::EM_IAMCU
, 32, false, "elf32-iamcu",
4451 do_instantiate_target()
4452 { return new Target_iamcu(); }
4455 Target_selector_iamcu target_selector_iamcu
;
4457 } // End anonymous namespace.