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*) const;
505 // Adjust -fsplit-stack code which calls non-split-stack code.
507 do_calls_non_split(Relobj
* object
, unsigned int shndx
,
508 section_offset_type fnoffset
, section_size_type fnsize
,
509 const unsigned char* prelocs
, size_t reloc_count
,
510 unsigned char* view
, section_size_type view_size
,
511 std::string
* from
, std::string
* to
) const;
513 // Return the size of the GOT section.
517 gold_assert(this->got_
!= NULL
);
518 return this->got_
->data_size();
521 // Return the number of entries in the GOT.
523 got_entry_count() const
525 if (this->got_
== NULL
)
527 return this->got_size() / 4;
530 // Return the number of entries in the PLT.
532 plt_entry_count() const;
534 // Return the offset of the first non-reserved PLT entry.
536 first_plt_entry_offset() const;
538 // Return the size of each PLT entry.
540 plt_entry_size() const;
543 // Instantiate the plt_ member.
544 // This chooses the right PLT flavor for an executable or a shared object.
545 Output_data_plt_i386
*
546 make_data_plt(Layout
* layout
,
547 Output_data_got_plt_i386
* got_plt
,
548 Output_data_space
* got_irelative
,
550 { return this->do_make_data_plt(layout
, got_plt
, got_irelative
, dyn
); }
552 virtual Output_data_plt_i386
*
553 do_make_data_plt(Layout
* layout
,
554 Output_data_got_plt_i386
* got_plt
,
555 Output_data_space
* got_irelative
,
559 return new Output_data_plt_i386_dyn(layout
, got_plt
, got_irelative
);
561 return new Output_data_plt_i386_exec(layout
, got_plt
, got_irelative
);
565 // The class which scans relocations.
570 get_reference_flags(unsigned int r_type
);
573 local(Symbol_table
* symtab
, Layout
* layout
, Target_i386
* target
,
574 Sized_relobj_file
<32, false>* object
,
575 unsigned int data_shndx
,
576 Output_section
* output_section
,
577 const elfcpp::Rel
<32, false>& reloc
, unsigned int r_type
,
578 const elfcpp::Sym
<32, false>& lsym
,
582 global(Symbol_table
* symtab
, Layout
* layout
, Target_i386
* target
,
583 Sized_relobj_file
<32, false>* object
,
584 unsigned int data_shndx
,
585 Output_section
* output_section
,
586 const elfcpp::Rel
<32, false>& reloc
, unsigned int r_type
,
590 local_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
592 Sized_relobj_file
<32, false>* object
,
593 unsigned int data_shndx
,
594 Output_section
* output_section
,
595 const elfcpp::Rel
<32, false>& reloc
,
597 const elfcpp::Sym
<32, false>& lsym
);
600 global_reloc_may_be_function_pointer(Symbol_table
* symtab
, Layout
* layout
,
602 Sized_relobj_file
<32, false>* object
,
603 unsigned int data_shndx
,
604 Output_section
* output_section
,
605 const elfcpp::Rel
<32, false>& reloc
,
610 possible_function_pointer_reloc(unsigned int r_type
);
613 reloc_needs_plt_for_ifunc(Sized_relobj_file
<32, false>*,
614 unsigned int r_type
);
617 unsupported_reloc_local(Sized_relobj_file
<32, false>*, unsigned int r_type
);
620 unsupported_reloc_global(Sized_relobj_file
<32, false>*, unsigned int r_type
,
624 // The class which implements relocation.
629 : skip_call_tls_get_addr_(false),
630 local_dynamic_type_(LOCAL_DYNAMIC_NONE
)
635 if (this->skip_call_tls_get_addr_
)
637 // FIXME: This needs to specify the location somehow.
638 gold_error(_("missing expected TLS relocation"));
642 // Return whether the static relocation needs to be applied.
644 should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
647 Output_section
* output_section
);
649 // Do a relocation. Return false if the caller should not issue
650 // any warnings about this relocation.
652 relocate(const Relocate_info
<32, false>*, unsigned int,
653 Target_i386
*, Output_section
*, size_t, const unsigned char*,
654 const Sized_symbol
<32>*, const Symbol_value
<32>*,
655 unsigned char*, elfcpp::Elf_types
<32>::Elf_Addr
,
659 // Do a TLS relocation.
661 relocate_tls(const Relocate_info
<32, false>*, Target_i386
* target
,
662 size_t relnum
, const elfcpp::Rel
<32, false>&,
663 unsigned int r_type
, const Sized_symbol
<32>*,
664 const Symbol_value
<32>*,
665 unsigned char*, elfcpp::Elf_types
<32>::Elf_Addr
,
668 // Do a TLS General-Dynamic to Initial-Exec transition.
670 tls_gd_to_ie(const Relocate_info
<32, false>*, size_t relnum
,
671 Output_segment
* tls_segment
,
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 Output_segment
* tls_segment
,
691 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
692 elfcpp::Elf_types
<32>::Elf_Addr value
,
694 section_size_type view_size
);
696 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
699 tls_desc_gd_to_le(const Relocate_info
<32, false>*, size_t relnum
,
700 Output_segment
* tls_segment
,
701 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
702 elfcpp::Elf_types
<32>::Elf_Addr value
,
704 section_size_type view_size
);
706 // Do a TLS Local-Dynamic to Local-Exec transition.
708 tls_ld_to_le(const Relocate_info
<32, false>*, size_t relnum
,
709 Output_segment
* tls_segment
,
710 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
711 elfcpp::Elf_types
<32>::Elf_Addr value
,
713 section_size_type view_size
);
715 // Do a TLS Initial-Exec to Local-Exec transition.
717 tls_ie_to_le(const Relocate_info
<32, false>*, size_t relnum
,
718 Output_segment
* tls_segment
,
719 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
720 elfcpp::Elf_types
<32>::Elf_Addr value
,
722 section_size_type view_size
);
724 // We need to keep track of which type of local dynamic relocation
725 // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
726 enum Local_dynamic_type
733 // This is set if we should skip the next reloc, which should be a
734 // PLT32 reloc against ___tls_get_addr.
735 bool skip_call_tls_get_addr_
;
736 // The type of local dynamic relocation we have seen in the section
737 // being relocated, if any.
738 Local_dynamic_type local_dynamic_type_
;
741 // A class for inquiring about properties of a relocation,
742 // used while scanning relocs during a relocatable link and
743 // garbage collection.
744 class Classify_reloc
:
745 public gold::Default_classify_reloc
<elfcpp::SHT_REL
, 32, false>
748 // Return the size of the addend of the relocation (only used for SHT_REL).
750 get_size_for_reloc(unsigned int, Relobj
*);
753 // Adjust TLS relocation type based on the options and whether this
754 // is a local symbol.
755 static tls::Tls_optimization
756 optimize_tls_reloc(bool is_final
, int r_type
);
758 // Check if relocation against this symbol is a candidate for
760 // mov foo@GOT(%reg), %reg
762 // lea foo@GOTOFF(%reg), %reg.
764 can_convert_mov_to_lea(const Symbol
* gsym
)
766 gold_assert(gsym
!= NULL
);
767 return (gsym
->type() != elfcpp::STT_GNU_IFUNC
768 && !gsym
->is_undefined ()
769 && !gsym
->is_from_dynobj()
770 && !gsym
->is_preemptible()
771 && (!parameters
->options().shared()
772 || (gsym
->visibility() != elfcpp::STV_DEFAULT
773 && gsym
->visibility() != elfcpp::STV_PROTECTED
)
774 || parameters
->options().Bsymbolic())
775 && strcmp(gsym
->name(), "_DYNAMIC") != 0);
778 // Get the GOT section, creating it if necessary.
779 Output_data_got
<32, false>*
780 got_section(Symbol_table
*, Layout
*);
782 // Get the GOT PLT section.
783 Output_data_got_plt_i386
*
784 got_plt_section() const
786 gold_assert(this->got_plt_
!= NULL
);
787 return this->got_plt_
;
790 // Get the GOT section for TLSDESC entries.
791 Output_data_got
<32, false>*
792 got_tlsdesc_section() const
794 gold_assert(this->got_tlsdesc_
!= NULL
);
795 return this->got_tlsdesc_
;
798 // Create the PLT section.
800 make_plt_section(Symbol_table
* symtab
, Layout
* layout
);
802 // Create a PLT entry for a global symbol.
804 make_plt_entry(Symbol_table
*, Layout
*, Symbol
*);
806 // Create a PLT entry for a local STT_GNU_IFUNC symbol.
808 make_local_ifunc_plt_entry(Symbol_table
*, Layout
*,
809 Sized_relobj_file
<32, false>* relobj
,
810 unsigned int local_sym_index
);
812 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
814 define_tls_base_symbol(Symbol_table
*, Layout
*);
816 // Create a GOT entry for the TLS module index.
818 got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
819 Sized_relobj_file
<32, false>* object
);
821 // Get the PLT section.
822 Output_data_plt_i386
*
825 gold_assert(this->plt_
!= NULL
);
829 // Get the dynamic reloc section, creating it if necessary.
831 rel_dyn_section(Layout
*);
833 // Get the section to use for TLS_DESC relocations.
835 rel_tls_desc_section(Layout
*) const;
837 // Get the section to use for IRELATIVE relocations.
839 rel_irelative_section(Layout
*);
841 // Add a potential copy relocation.
843 copy_reloc(Symbol_table
* symtab
, Layout
* layout
,
844 Sized_relobj_file
<32, false>* object
,
845 unsigned int shndx
, Output_section
* output_section
,
846 Symbol
* sym
, const elfcpp::Rel
<32, false>& reloc
)
848 unsigned int r_type
= elfcpp::elf_r_type
<32>(reloc
.get_r_info());
849 this->copy_relocs_
.copy_reloc(symtab
, layout
,
850 symtab
->get_sized_symbol
<32>(sym
),
851 object
, shndx
, output_section
,
852 r_type
, reloc
.get_r_offset(), 0,
853 this->rel_dyn_section(layout
));
856 // Information about this specific target which we pass to the
857 // general Target structure.
858 static const Target::Target_info i386_info
;
860 // The types of GOT entries needed for this platform.
861 // These values are exposed to the ABI in an incremental link.
862 // Do not renumber existing values without changing the version
863 // number of the .gnu_incremental_inputs section.
866 GOT_TYPE_STANDARD
= 0, // GOT entry for a regular symbol
867 GOT_TYPE_TLS_NOFFSET
= 1, // GOT entry for negative TLS offset
868 GOT_TYPE_TLS_OFFSET
= 2, // GOT entry for positive TLS offset
869 GOT_TYPE_TLS_PAIR
= 3, // GOT entry for TLS module/offset pair
870 GOT_TYPE_TLS_DESC
= 4 // GOT entry for TLS_DESC pair
874 Output_data_got
<32, false>* got_
;
876 Output_data_plt_i386
* plt_
;
877 // The GOT PLT section.
878 Output_data_got_plt_i386
* got_plt_
;
879 // The GOT section for IRELATIVE relocations.
880 Output_data_space
* got_irelative_
;
881 // The GOT section for TLSDESC relocations.
882 Output_data_got
<32, false>* got_tlsdesc_
;
883 // The _GLOBAL_OFFSET_TABLE_ symbol.
884 Symbol
* global_offset_table_
;
885 // The dynamic reloc section.
886 Reloc_section
* rel_dyn_
;
887 // The section to use for IRELATIVE relocs.
888 Reloc_section
* rel_irelative_
;
889 // Relocs saved to avoid a COPY reloc.
890 Copy_relocs
<elfcpp::SHT_REL
, 32, false> copy_relocs_
;
891 // Offset of the GOT entry for the TLS module index.
892 unsigned int got_mod_index_offset_
;
893 // True if the _TLS_MODULE_BASE_ symbol has been defined.
894 bool tls_base_symbol_defined_
;
897 const Target::Target_info
Target_i386::i386_info
=
900 false, // is_big_endian
901 elfcpp::EM_386
, // machine_code
902 false, // has_make_symbol
903 false, // has_resolve
904 true, // has_code_fill
905 true, // is_default_stack_executable
906 true, // can_icf_inline_merge_sections
908 "/usr/lib/libc.so.1", // dynamic_linker
909 0x08048000, // default_text_segment_address
910 0x1000, // abi_pagesize (overridable by -z max-page-size)
911 0x1000, // common_pagesize (overridable by -z common-page-size)
912 false, // isolate_execinstr
914 elfcpp::SHN_UNDEF
, // small_common_shndx
915 elfcpp::SHN_UNDEF
, // large_common_shndx
916 0, // small_common_section_flags
917 0, // large_common_section_flags
918 NULL
, // attributes_section
919 NULL
, // attributes_vendor
920 "_start", // entry_symbol_name
921 32, // hash_entry_size
924 // Get the GOT section, creating it if necessary.
926 Output_data_got
<32, false>*
927 Target_i386::got_section(Symbol_table
* symtab
, Layout
* layout
)
929 if (this->got_
== NULL
)
931 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
933 this->got_
= new Output_data_got
<32, false>();
935 // When using -z now, we can treat .got.plt as a relro section.
936 // Without -z now, it is modified after program startup by lazy
938 bool is_got_plt_relro
= parameters
->options().now();
939 Output_section_order got_order
= (is_got_plt_relro
942 Output_section_order got_plt_order
= (is_got_plt_relro
944 : ORDER_NON_RELRO_FIRST
);
946 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
948 | elfcpp::SHF_WRITE
),
949 this->got_
, got_order
, true);
951 this->got_plt_
= new Output_data_got_plt_i386(layout
);
952 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
954 | elfcpp::SHF_WRITE
),
955 this->got_plt_
, got_plt_order
,
958 // The first three entries are reserved.
959 this->got_plt_
->set_current_data_size(3 * 4);
961 if (!is_got_plt_relro
)
963 // Those bytes can go into the relro segment.
964 layout
->increase_relro(3 * 4);
967 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
968 this->global_offset_table_
=
969 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
970 Symbol_table::PREDEFINED
,
972 0, 0, elfcpp::STT_OBJECT
,
974 elfcpp::STV_HIDDEN
, 0,
977 // If there are any IRELATIVE relocations, they get GOT entries
978 // in .got.plt after the jump slot relocations.
979 this->got_irelative_
= new Output_data_space(4, "** GOT IRELATIVE PLT");
980 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
982 | elfcpp::SHF_WRITE
),
983 this->got_irelative_
,
984 got_plt_order
, is_got_plt_relro
);
986 // If there are any TLSDESC relocations, they get GOT entries in
987 // .got.plt after the jump slot entries.
988 this->got_tlsdesc_
= new Output_data_got
<32, false>();
989 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
991 | elfcpp::SHF_WRITE
),
993 got_plt_order
, is_got_plt_relro
);
999 // Get the dynamic reloc section, creating it if necessary.
1001 Target_i386::Reloc_section
*
1002 Target_i386::rel_dyn_section(Layout
* layout
)
1004 if (this->rel_dyn_
== NULL
)
1006 gold_assert(layout
!= NULL
);
1007 this->rel_dyn_
= new Reloc_section(parameters
->options().combreloc());
1008 layout
->add_output_section_data(".rel.dyn", elfcpp::SHT_REL
,
1009 elfcpp::SHF_ALLOC
, this->rel_dyn_
,
1010 ORDER_DYNAMIC_RELOCS
, false);
1012 return this->rel_dyn_
;
1015 // Get the section to use for IRELATIVE relocs, creating it if
1016 // necessary. These go in .rel.dyn, but only after all other dynamic
1017 // relocations. They need to follow the other dynamic relocations so
1018 // that they can refer to global variables initialized by those
1021 Target_i386::Reloc_section
*
1022 Target_i386::rel_irelative_section(Layout
* layout
)
1024 if (this->rel_irelative_
== NULL
)
1026 // Make sure we have already create the dynamic reloc section.
1027 this->rel_dyn_section(layout
);
1028 this->rel_irelative_
= new Reloc_section(false);
1029 layout
->add_output_section_data(".rel.dyn", elfcpp::SHT_REL
,
1030 elfcpp::SHF_ALLOC
, this->rel_irelative_
,
1031 ORDER_DYNAMIC_RELOCS
, false);
1032 gold_assert(this->rel_dyn_
->output_section()
1033 == this->rel_irelative_
->output_section());
1035 return this->rel_irelative_
;
1038 // Write the first three reserved words of the .got.plt section.
1039 // The remainder of the section is written while writing the PLT
1040 // in Output_data_plt_i386::do_write.
1043 Output_data_got_plt_i386::do_write(Output_file
* of
)
1045 // The first entry in the GOT is the address of the .dynamic section
1046 // aka the PT_DYNAMIC segment. The next two entries are reserved.
1047 // We saved space for them when we created the section in
1048 // Target_i386::got_section.
1049 const off_t got_file_offset
= this->offset();
1050 gold_assert(this->data_size() >= 12);
1051 unsigned char* const got_view
= of
->get_output_view(got_file_offset
, 12);
1052 Output_section
* dynamic
= this->layout_
->dynamic_section();
1053 uint32_t dynamic_addr
= dynamic
== NULL
? 0 : dynamic
->address();
1054 elfcpp::Swap
<32, false>::writeval(got_view
, dynamic_addr
);
1055 memset(got_view
+ 4, 0, 8);
1056 of
->write_output_view(got_file_offset
, 12, got_view
);
1059 // Create the PLT section. The ordinary .got section is an argument,
1060 // since we need to refer to the start. We also create our own .got
1061 // section just for PLT entries.
1063 Output_data_plt_i386::Output_data_plt_i386(Layout
* layout
,
1065 Output_data_got_plt_i386
* got_plt
,
1066 Output_data_space
* got_irelative
)
1067 : Output_section_data(addralign
),
1068 tls_desc_rel_(NULL
), irelative_rel_(NULL
), got_plt_(got_plt
),
1069 got_irelative_(got_irelative
), count_(0), irelative_count_(0),
1070 global_ifuncs_(), local_ifuncs_()
1072 this->rel_
= new Reloc_section(false);
1073 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
1074 elfcpp::SHF_ALLOC
, this->rel_
,
1075 ORDER_DYNAMIC_PLT_RELOCS
, false);
1079 Output_data_plt_i386::do_adjust_output_section(Output_section
* os
)
1081 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
1082 // linker, and so do we.
1086 // Add an entry to the PLT.
1089 Output_data_plt_i386::add_entry(Symbol_table
* symtab
, Layout
* layout
,
1092 gold_assert(!gsym
->has_plt_offset());
1094 // Every PLT entry needs a reloc.
1095 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1096 && gsym
->can_use_relative_reloc(false))
1098 gsym
->set_plt_offset(this->irelative_count_
* this->get_plt_entry_size());
1099 ++this->irelative_count_
;
1100 section_offset_type got_offset
=
1101 this->got_irelative_
->current_data_size();
1102 this->got_irelative_
->set_current_data_size(got_offset
+ 4);
1103 Reloc_section
* rel
= this->rel_irelative(symtab
, layout
);
1104 rel
->add_symbolless_global_addend(gsym
, elfcpp::R_386_IRELATIVE
,
1105 this->got_irelative_
, got_offset
);
1106 struct Global_ifunc gi
;
1108 gi
.got_offset
= got_offset
;
1109 this->global_ifuncs_
.push_back(gi
);
1113 // When setting the PLT offset we skip the initial reserved PLT
1115 gsym
->set_plt_offset((this->count_
+ 1) * this->get_plt_entry_size());
1119 section_offset_type got_offset
= this->got_plt_
->current_data_size();
1121 // Every PLT entry needs a GOT entry which points back to the
1122 // PLT entry (this will be changed by the dynamic linker,
1123 // normally lazily when the function is called).
1124 this->got_plt_
->set_current_data_size(got_offset
+ 4);
1126 gsym
->set_needs_dynsym_entry();
1127 this->rel_
->add_global(gsym
, elfcpp::R_386_JUMP_SLOT
, this->got_plt_
,
1131 // Note that we don't need to save the symbol. The contents of the
1132 // PLT are independent of which symbols are used. The symbols only
1133 // appear in the relocations.
1136 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
1140 Output_data_plt_i386::add_local_ifunc_entry(
1141 Symbol_table
* symtab
,
1143 Sized_relobj_file
<32, false>* relobj
,
1144 unsigned int local_sym_index
)
1146 unsigned int plt_offset
= this->irelative_count_
* this->get_plt_entry_size();
1147 ++this->irelative_count_
;
1149 section_offset_type got_offset
= this->got_irelative_
->current_data_size();
1151 // Every PLT entry needs a GOT entry which points back to the PLT
1153 this->got_irelative_
->set_current_data_size(got_offset
+ 4);
1155 // Every PLT entry needs a reloc.
1156 Reloc_section
* rel
= this->rel_irelative(symtab
, layout
);
1157 rel
->add_symbolless_local_addend(relobj
, local_sym_index
,
1158 elfcpp::R_386_IRELATIVE
,
1159 this->got_irelative_
, got_offset
);
1161 struct Local_ifunc li
;
1163 li
.local_sym_index
= local_sym_index
;
1164 li
.got_offset
= got_offset
;
1165 this->local_ifuncs_
.push_back(li
);
1170 // Return where the TLS_DESC relocations should go, creating it if
1171 // necessary. These follow the JUMP_SLOT relocations.
1173 Output_data_plt_i386::Reloc_section
*
1174 Output_data_plt_i386::rel_tls_desc(Layout
* layout
)
1176 if (this->tls_desc_rel_
== NULL
)
1178 this->tls_desc_rel_
= new Reloc_section(false);
1179 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
1180 elfcpp::SHF_ALLOC
, this->tls_desc_rel_
,
1181 ORDER_DYNAMIC_PLT_RELOCS
, false);
1182 gold_assert(this->tls_desc_rel_
->output_section()
1183 == this->rel_
->output_section());
1185 return this->tls_desc_rel_
;
1188 // Return where the IRELATIVE relocations should go in the PLT. These
1189 // follow the JUMP_SLOT and TLS_DESC relocations.
1191 Output_data_plt_i386::Reloc_section
*
1192 Output_data_plt_i386::rel_irelative(Symbol_table
* symtab
, Layout
* layout
)
1194 if (this->irelative_rel_
== NULL
)
1196 // Make sure we have a place for the TLS_DESC relocations, in
1197 // case we see any later on.
1198 this->rel_tls_desc(layout
);
1199 this->irelative_rel_
= new Reloc_section(false);
1200 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
1201 elfcpp::SHF_ALLOC
, this->irelative_rel_
,
1202 ORDER_DYNAMIC_PLT_RELOCS
, false);
1203 gold_assert(this->irelative_rel_
->output_section()
1204 == this->rel_
->output_section());
1206 if (parameters
->doing_static_link())
1208 // A statically linked executable will only have a .rel.plt
1209 // section to hold R_386_IRELATIVE relocs for STT_GNU_IFUNC
1210 // symbols. The library will use these symbols to locate
1211 // the IRELATIVE relocs at program startup time.
1212 symtab
->define_in_output_data("__rel_iplt_start", NULL
,
1213 Symbol_table::PREDEFINED
,
1214 this->irelative_rel_
, 0, 0,
1215 elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
1216 elfcpp::STV_HIDDEN
, 0, false, true);
1217 symtab
->define_in_output_data("__rel_iplt_end", NULL
,
1218 Symbol_table::PREDEFINED
,
1219 this->irelative_rel_
, 0, 0,
1220 elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
1221 elfcpp::STV_HIDDEN
, 0, true, true);
1224 return this->irelative_rel_
;
1227 // Return the PLT address to use for a global symbol.
1230 Output_data_plt_i386::address_for_global(const Symbol
* gsym
)
1232 uint64_t offset
= 0;
1233 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1234 && gsym
->can_use_relative_reloc(false))
1235 offset
= (this->count_
+ 1) * this->get_plt_entry_size();
1236 return this->address() + offset
+ gsym
->plt_offset();
1239 // Return the PLT address to use for a local symbol. These are always
1240 // IRELATIVE relocs.
1243 Output_data_plt_i386::address_for_local(const Relobj
* object
,
1246 return (this->address()
1247 + (this->count_
+ 1) * this->get_plt_entry_size()
1248 + object
->local_plt_offset(r_sym
));
1251 // The first entry in the PLT for an executable.
1253 const unsigned char Output_data_plt_i386_exec::first_plt_entry
[plt_entry_size
] =
1255 0xff, 0x35, // pushl contents of memory address
1256 0, 0, 0, 0, // replaced with address of .got + 4
1257 0xff, 0x25, // jmp indirect
1258 0, 0, 0, 0, // replaced with address of .got + 8
1259 0, 0, 0, 0 // unused
1263 Output_data_plt_i386_exec::do_fill_first_plt_entry(
1265 elfcpp::Elf_types
<32>::Elf_Addr got_address
)
1267 memcpy(pov
, first_plt_entry
, plt_entry_size
);
1268 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 4);
1269 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 8);
1272 // The first entry in the PLT for a shared object.
1274 const unsigned char Output_data_plt_i386_dyn::first_plt_entry
[plt_entry_size
] =
1276 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
1277 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
1278 0, 0, 0, 0 // unused
1282 Output_data_plt_i386_dyn::do_fill_first_plt_entry(
1284 elfcpp::Elf_types
<32>::Elf_Addr
)
1286 memcpy(pov
, first_plt_entry
, plt_entry_size
);
1289 // Subsequent entries in the PLT for an executable.
1291 const unsigned char Output_data_plt_i386_exec::plt_entry
[plt_entry_size
] =
1293 0xff, 0x25, // jmp indirect
1294 0, 0, 0, 0, // replaced with address of symbol in .got
1295 0x68, // pushl immediate
1296 0, 0, 0, 0, // replaced with offset into relocation table
1297 0xe9, // jmp relative
1298 0, 0, 0, 0 // replaced with offset to start of .plt
1302 Output_data_plt_i386_exec::do_fill_plt_entry(
1304 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
1305 unsigned int got_offset
,
1306 unsigned int plt_offset
,
1307 unsigned int plt_rel_offset
)
1309 memcpy(pov
, plt_entry
, plt_entry_size
);
1310 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
1311 got_address
+ got_offset
);
1312 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_rel_offset
);
1313 elfcpp::Swap
<32, false>::writeval(pov
+ 12, - (plt_offset
+ 12 + 4));
1317 // Subsequent entries in the PLT for a shared object.
1319 const unsigned char Output_data_plt_i386_dyn::plt_entry
[plt_entry_size
] =
1321 0xff, 0xa3, // jmp *offset(%ebx)
1322 0, 0, 0, 0, // replaced with offset of symbol in .got
1323 0x68, // pushl immediate
1324 0, 0, 0, 0, // replaced with offset into relocation table
1325 0xe9, // jmp relative
1326 0, 0, 0, 0 // replaced with offset to start of .plt
1330 Output_data_plt_i386_dyn::do_fill_plt_entry(unsigned char* pov
,
1331 elfcpp::Elf_types
<32>::Elf_Addr
,
1332 unsigned int got_offset
,
1333 unsigned int plt_offset
,
1334 unsigned int plt_rel_offset
)
1336 memcpy(pov
, plt_entry
, plt_entry_size
);
1337 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
1338 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_rel_offset
);
1339 elfcpp::Swap
<32, false>::writeval(pov
+ 12, - (plt_offset
+ 12 + 4));
1343 // The .eh_frame unwind information for the PLT.
1346 Output_data_plt_i386::plt_eh_frame_cie
[plt_eh_frame_cie_size
] =
1349 'z', // Augmentation: augmentation size included.
1350 'R', // Augmentation: FDE encoding included.
1351 '\0', // End of augmentation string.
1352 1, // Code alignment factor.
1353 0x7c, // Data alignment factor.
1354 8, // Return address column.
1355 1, // Augmentation size.
1356 (elfcpp::DW_EH_PE_pcrel
// FDE encoding.
1357 | elfcpp::DW_EH_PE_sdata4
),
1358 elfcpp::DW_CFA_def_cfa
, 4, 4, // DW_CFA_def_cfa: r4 (esp) ofs 4.
1359 elfcpp::DW_CFA_offset
+ 8, 1, // DW_CFA_offset: r8 (eip) at cfa-4.
1360 elfcpp::DW_CFA_nop
, // Align to 16 bytes.
1365 Output_data_plt_i386_standard::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
1367 0, 0, 0, 0, // Replaced with offset to .plt.
1368 0, 0, 0, 0, // Replaced with size of .plt.
1369 0, // Augmentation size.
1370 elfcpp::DW_CFA_def_cfa_offset
, 8, // DW_CFA_def_cfa_offset: 8.
1371 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
1372 elfcpp::DW_CFA_def_cfa_offset
, 12, // DW_CFA_def_cfa_offset: 12.
1373 elfcpp::DW_CFA_advance_loc
+ 10, // Advance 10 to __PLT__ + 16.
1374 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
1375 11, // Block length.
1376 elfcpp::DW_OP_breg4
, 4, // Push %esp + 4.
1377 elfcpp::DW_OP_breg8
, 0, // Push %eip.
1378 elfcpp::DW_OP_lit15
, // Push 0xf.
1379 elfcpp::DW_OP_and
, // & (%eip & 0xf).
1380 elfcpp::DW_OP_lit11
, // Push 0xb.
1381 elfcpp::DW_OP_ge
, // >= ((%eip & 0xf) >= 0xb)
1382 elfcpp::DW_OP_lit2
, // Push 2.
1383 elfcpp::DW_OP_shl
, // << (((%eip & 0xf) >= 0xb) << 2)
1384 elfcpp::DW_OP_plus
, // + ((((%eip&0xf)>=0xb)<<2)+%esp+4
1385 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
1391 // Write out the PLT. This uses the hand-coded instructions above,
1392 // and adjusts them as needed. This is all specified by the i386 ELF
1393 // Processor Supplement.
1396 Output_data_plt_i386::do_write(Output_file
* of
)
1398 const off_t offset
= this->offset();
1399 const section_size_type oview_size
=
1400 convert_to_section_size_type(this->data_size());
1401 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
1403 const off_t got_file_offset
= this->got_plt_
->offset();
1404 gold_assert(parameters
->incremental_update()
1405 || (got_file_offset
+ this->got_plt_
->data_size()
1406 == this->got_irelative_
->offset()));
1407 const section_size_type got_size
=
1408 convert_to_section_size_type(this->got_plt_
->data_size()
1409 + this->got_irelative_
->data_size());
1411 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
1414 unsigned char* pov
= oview
;
1416 elfcpp::Elf_types
<32>::Elf_Addr plt_address
= this->address();
1417 elfcpp::Elf_types
<32>::Elf_Addr got_address
= this->got_plt_
->address();
1419 this->fill_first_plt_entry(pov
, got_address
);
1420 pov
+= this->get_plt_entry_size();
1422 // The first three entries in the GOT are reserved, and are written
1423 // by Output_data_got_plt_i386::do_write.
1424 unsigned char* got_pov
= got_view
+ 12;
1426 const int rel_size
= elfcpp::Elf_sizes
<32>::rel_size
;
1428 unsigned int plt_offset
= this->get_plt_entry_size();
1429 unsigned int plt_rel_offset
= 0;
1430 unsigned int got_offset
= 12;
1431 const unsigned int count
= this->count_
+ this->irelative_count_
;
1432 for (unsigned int i
= 0;
1435 pov
+= this->get_plt_entry_size(),
1437 plt_offset
+= this->get_plt_entry_size(),
1438 plt_rel_offset
+= rel_size
,
1441 // Set and adjust the PLT entry itself.
1442 unsigned int lazy_offset
= this->fill_plt_entry(pov
,
1448 // Set the entry in the GOT.
1449 elfcpp::Swap
<32, false>::writeval(got_pov
,
1450 plt_address
+ plt_offset
+ lazy_offset
);
1453 // If any STT_GNU_IFUNC symbols have PLT entries, we need to change
1454 // the GOT to point to the actual symbol value, rather than point to
1455 // the PLT entry. That will let the dynamic linker call the right
1456 // function when resolving IRELATIVE relocations.
1457 unsigned char* got_irelative_view
= got_view
+ this->got_plt_
->data_size();
1458 for (std::vector
<Global_ifunc
>::const_iterator p
=
1459 this->global_ifuncs_
.begin();
1460 p
!= this->global_ifuncs_
.end();
1463 const Sized_symbol
<32>* ssym
=
1464 static_cast<const Sized_symbol
<32>*>(p
->sym
);
1465 elfcpp::Swap
<32, false>::writeval(got_irelative_view
+ p
->got_offset
,
1469 for (std::vector
<Local_ifunc
>::const_iterator p
=
1470 this->local_ifuncs_
.begin();
1471 p
!= this->local_ifuncs_
.end();
1474 const Symbol_value
<32>* psymval
=
1475 p
->object
->local_symbol(p
->local_sym_index
);
1476 elfcpp::Swap
<32, false>::writeval(got_irelative_view
+ p
->got_offset
,
1477 psymval
->value(p
->object
, 0));
1480 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
1481 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
1483 of
->write_output_view(offset
, oview_size
, oview
);
1484 of
->write_output_view(got_file_offset
, got_size
, got_view
);
1487 // Create the PLT section.
1490 Target_i386::make_plt_section(Symbol_table
* symtab
, Layout
* layout
)
1492 if (this->plt_
== NULL
)
1494 // Create the GOT sections first.
1495 this->got_section(symtab
, layout
);
1497 const bool dyn
= parameters
->options().output_is_position_independent();
1498 this->plt_
= this->make_data_plt(layout
,
1500 this->got_irelative_
,
1503 // Add unwind information if requested.
1504 if (parameters
->options().ld_generated_unwind_info())
1505 this->plt_
->add_eh_frame(layout
);
1507 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
1509 | elfcpp::SHF_EXECINSTR
),
1510 this->plt_
, ORDER_PLT
, false);
1512 // Make the sh_info field of .rel.plt point to .plt.
1513 Output_section
* rel_plt_os
= this->plt_
->rel_plt()->output_section();
1514 rel_plt_os
->set_info_section(this->plt_
->output_section());
1518 // Create a PLT entry for a global symbol.
1521 Target_i386::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
, Symbol
* gsym
)
1523 if (gsym
->has_plt_offset())
1525 if (this->plt_
== NULL
)
1526 this->make_plt_section(symtab
, layout
);
1527 this->plt_
->add_entry(symtab
, layout
, gsym
);
1530 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1533 Target_i386::make_local_ifunc_plt_entry(Symbol_table
* symtab
, Layout
* layout
,
1534 Sized_relobj_file
<32, false>* relobj
,
1535 unsigned int local_sym_index
)
1537 if (relobj
->local_has_plt_offset(local_sym_index
))
1539 if (this->plt_
== NULL
)
1540 this->make_plt_section(symtab
, layout
);
1541 unsigned int plt_offset
= this->plt_
->add_local_ifunc_entry(symtab
, layout
,
1544 relobj
->set_local_plt_offset(local_sym_index
, plt_offset
);
1547 // Return the number of entries in the PLT.
1550 Target_i386::plt_entry_count() const
1552 if (this->plt_
== NULL
)
1554 return this->plt_
->entry_count();
1557 // Return the offset of the first non-reserved PLT entry.
1560 Target_i386::first_plt_entry_offset() const
1562 return this->plt_
->first_plt_entry_offset();
1565 // Return the size of each PLT entry.
1568 Target_i386::plt_entry_size() const
1570 return this->plt_
->get_plt_entry_size();
1573 // Get the section to use for TLS_DESC relocations.
1575 Target_i386::Reloc_section
*
1576 Target_i386::rel_tls_desc_section(Layout
* layout
) const
1578 return this->plt_section()->rel_tls_desc(layout
);
1581 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1584 Target_i386::define_tls_base_symbol(Symbol_table
* symtab
, Layout
* layout
)
1586 if (this->tls_base_symbol_defined_
)
1589 Output_segment
* tls_segment
= layout
->tls_segment();
1590 if (tls_segment
!= NULL
)
1592 bool is_exec
= parameters
->options().output_is_executable();
1593 symtab
->define_in_output_segment("_TLS_MODULE_BASE_", NULL
,
1594 Symbol_table::PREDEFINED
,
1598 elfcpp::STV_HIDDEN
, 0,
1600 ? Symbol::SEGMENT_END
1601 : Symbol::SEGMENT_START
),
1604 this->tls_base_symbol_defined_
= true;
1607 // Create a GOT entry for the TLS module index.
1610 Target_i386::got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
1611 Sized_relobj_file
<32, false>* object
)
1613 if (this->got_mod_index_offset_
== -1U)
1615 gold_assert(symtab
!= NULL
&& layout
!= NULL
&& object
!= NULL
);
1616 Reloc_section
* rel_dyn
= this->rel_dyn_section(layout
);
1617 Output_data_got
<32, false>* got
= this->got_section(symtab
, layout
);
1618 unsigned int got_offset
= got
->add_constant(0);
1619 rel_dyn
->add_local(object
, 0, elfcpp::R_386_TLS_DTPMOD32
, got
,
1621 got
->add_constant(0);
1622 this->got_mod_index_offset_
= got_offset
;
1624 return this->got_mod_index_offset_
;
1627 // Optimize the TLS relocation type based on what we know about the
1628 // symbol. IS_FINAL is true if the final address of this symbol is
1629 // known at link time.
1631 tls::Tls_optimization
1632 Target_i386::optimize_tls_reloc(bool is_final
, int r_type
)
1634 // If we are generating a shared library, then we can't do anything
1636 if (parameters
->options().shared())
1637 return tls::TLSOPT_NONE
;
1641 case elfcpp::R_386_TLS_GD
:
1642 case elfcpp::R_386_TLS_GOTDESC
:
1643 case elfcpp::R_386_TLS_DESC_CALL
:
1644 // These are General-Dynamic which permits fully general TLS
1645 // access. Since we know that we are generating an executable,
1646 // we can convert this to Initial-Exec. If we also know that
1647 // this is a local symbol, we can further switch to Local-Exec.
1649 return tls::TLSOPT_TO_LE
;
1650 return tls::TLSOPT_TO_IE
;
1652 case elfcpp::R_386_TLS_LDM
:
1653 // This is Local-Dynamic, which refers to a local symbol in the
1654 // dynamic TLS block. Since we know that we generating an
1655 // executable, we can switch to Local-Exec.
1656 return tls::TLSOPT_TO_LE
;
1658 case elfcpp::R_386_TLS_LDO_32
:
1659 // Another type of Local-Dynamic relocation.
1660 return tls::TLSOPT_TO_LE
;
1662 case elfcpp::R_386_TLS_IE
:
1663 case elfcpp::R_386_TLS_GOTIE
:
1664 case elfcpp::R_386_TLS_IE_32
:
1665 // These are Initial-Exec relocs which get the thread offset
1666 // from the GOT. If we know that we are linking against the
1667 // local symbol, we can switch to Local-Exec, which links the
1668 // thread offset into the instruction.
1670 return tls::TLSOPT_TO_LE
;
1671 return tls::TLSOPT_NONE
;
1673 case elfcpp::R_386_TLS_LE
:
1674 case elfcpp::R_386_TLS_LE_32
:
1675 // When we already have Local-Exec, there is nothing further we
1677 return tls::TLSOPT_NONE
;
1684 // Get the Reference_flags for a particular relocation.
1687 Target_i386::Scan::get_reference_flags(unsigned int r_type
)
1691 case elfcpp::R_386_NONE
:
1692 case elfcpp::R_386_GNU_VTINHERIT
:
1693 case elfcpp::R_386_GNU_VTENTRY
:
1694 case elfcpp::R_386_GOTPC
:
1695 // No symbol reference.
1698 case elfcpp::R_386_32
:
1699 case elfcpp::R_386_16
:
1700 case elfcpp::R_386_8
:
1701 return Symbol::ABSOLUTE_REF
;
1703 case elfcpp::R_386_PC32
:
1704 case elfcpp::R_386_PC16
:
1705 case elfcpp::R_386_PC8
:
1706 case elfcpp::R_386_GOTOFF
:
1707 return Symbol::RELATIVE_REF
;
1709 case elfcpp::R_386_PLT32
:
1710 return Symbol::FUNCTION_CALL
| Symbol::RELATIVE_REF
;
1712 case elfcpp::R_386_GOT32
:
1713 case elfcpp::R_386_GOT32X
:
1715 return Symbol::ABSOLUTE_REF
;
1717 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1718 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1719 case elfcpp::R_386_TLS_DESC_CALL
:
1720 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1721 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1722 case elfcpp::R_386_TLS_IE
: // Initial-exec
1723 case elfcpp::R_386_TLS_IE_32
:
1724 case elfcpp::R_386_TLS_GOTIE
:
1725 case elfcpp::R_386_TLS_LE
: // Local-exec
1726 case elfcpp::R_386_TLS_LE_32
:
1727 return Symbol::TLS_REF
;
1729 case elfcpp::R_386_COPY
:
1730 case elfcpp::R_386_GLOB_DAT
:
1731 case elfcpp::R_386_JUMP_SLOT
:
1732 case elfcpp::R_386_RELATIVE
:
1733 case elfcpp::R_386_IRELATIVE
:
1734 case elfcpp::R_386_TLS_TPOFF
:
1735 case elfcpp::R_386_TLS_DTPMOD32
:
1736 case elfcpp::R_386_TLS_DTPOFF32
:
1737 case elfcpp::R_386_TLS_TPOFF32
:
1738 case elfcpp::R_386_TLS_DESC
:
1739 case elfcpp::R_386_32PLT
:
1740 case elfcpp::R_386_TLS_GD_32
:
1741 case elfcpp::R_386_TLS_GD_PUSH
:
1742 case elfcpp::R_386_TLS_GD_CALL
:
1743 case elfcpp::R_386_TLS_GD_POP
:
1744 case elfcpp::R_386_TLS_LDM_32
:
1745 case elfcpp::R_386_TLS_LDM_PUSH
:
1746 case elfcpp::R_386_TLS_LDM_CALL
:
1747 case elfcpp::R_386_TLS_LDM_POP
:
1748 case elfcpp::R_386_USED_BY_INTEL_200
:
1750 // Not expected. We will give an error later.
1755 // Report an unsupported relocation against a local symbol.
1758 Target_i386::Scan::unsupported_reloc_local(Sized_relobj_file
<32, false>* object
,
1759 unsigned int r_type
)
1761 gold_error(_("%s: unsupported reloc %u against local symbol"),
1762 object
->name().c_str(), r_type
);
1765 // Return whether we need to make a PLT entry for a relocation of a
1766 // given type against a STT_GNU_IFUNC symbol.
1769 Target_i386::Scan::reloc_needs_plt_for_ifunc(
1770 Sized_relobj_file
<32, false>* object
,
1771 unsigned int r_type
)
1773 int flags
= Scan::get_reference_flags(r_type
);
1774 if (flags
& Symbol::TLS_REF
)
1775 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
1776 object
->name().c_str(), r_type
);
1780 // Scan a relocation for a local symbol.
1783 Target_i386::Scan::local(Symbol_table
* symtab
,
1785 Target_i386
* target
,
1786 Sized_relobj_file
<32, false>* object
,
1787 unsigned int data_shndx
,
1788 Output_section
* output_section
,
1789 const elfcpp::Rel
<32, false>& reloc
,
1790 unsigned int r_type
,
1791 const elfcpp::Sym
<32, false>& lsym
,
1797 // A local STT_GNU_IFUNC symbol may require a PLT entry.
1798 if (lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
1799 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
1801 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1802 target
->make_local_ifunc_plt_entry(symtab
, layout
, object
, r_sym
);
1807 case elfcpp::R_386_NONE
:
1808 case elfcpp::R_386_GNU_VTINHERIT
:
1809 case elfcpp::R_386_GNU_VTENTRY
:
1812 case elfcpp::R_386_32
:
1813 // If building a shared library (or a position-independent
1814 // executable), we need to create a dynamic relocation for
1815 // this location. The relocation applied at link time will
1816 // apply the link-time value, so we flag the location with
1817 // an R_386_RELATIVE relocation so the dynamic loader can
1818 // relocate it easily.
1819 if (parameters
->options().output_is_position_independent())
1821 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1822 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1823 rel_dyn
->add_local_relative(object
, r_sym
, elfcpp::R_386_RELATIVE
,
1824 output_section
, data_shndx
,
1825 reloc
.get_r_offset());
1829 case elfcpp::R_386_16
:
1830 case elfcpp::R_386_8
:
1831 // If building a shared library (or a position-independent
1832 // executable), we need to create a dynamic relocation for
1833 // this location. Because the addend needs to remain in the
1834 // data section, we need to be careful not to apply this
1835 // relocation statically.
1836 if (parameters
->options().output_is_position_independent())
1838 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1839 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1840 if (lsym
.get_st_type() != elfcpp::STT_SECTION
)
1841 rel_dyn
->add_local(object
, r_sym
, r_type
, output_section
,
1842 data_shndx
, reloc
.get_r_offset());
1845 gold_assert(lsym
.get_st_value() == 0);
1846 unsigned int shndx
= lsym
.get_st_shndx();
1848 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
,
1851 object
->error(_("section symbol %u has bad shndx %u"),
1854 rel_dyn
->add_local_section(object
, shndx
,
1855 r_type
, output_section
,
1856 data_shndx
, reloc
.get_r_offset());
1861 case elfcpp::R_386_PC32
:
1862 case elfcpp::R_386_PC16
:
1863 case elfcpp::R_386_PC8
:
1866 case elfcpp::R_386_PLT32
:
1867 // Since we know this is a local symbol, we can handle this as a
1871 case elfcpp::R_386_GOTOFF
:
1872 case elfcpp::R_386_GOTPC
:
1873 // We need a GOT section.
1874 target
->got_section(symtab
, layout
);
1877 case elfcpp::R_386_GOT32
:
1878 case elfcpp::R_386_GOT32X
:
1880 // We need GOT section.
1881 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
1883 // If the relocation symbol isn't IFUNC,
1884 // and is local, then we will convert
1885 // mov foo@GOT(%reg), %reg
1887 // lea foo@GOTOFF(%reg), %reg
1888 // in Relocate::relocate.
1889 if (reloc
.get_r_offset() >= 2
1890 && lsym
.get_st_type() != elfcpp::STT_GNU_IFUNC
)
1892 section_size_type stype
;
1893 const unsigned char* view
= object
->section_contents(data_shndx
,
1895 if (view
[reloc
.get_r_offset() - 2] == 0x8b)
1899 // Otherwise, the symbol requires a GOT entry.
1900 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1902 // For a STT_GNU_IFUNC symbol we want the PLT offset. That
1903 // lets function pointers compare correctly with shared
1904 // libraries. Otherwise we would need an IRELATIVE reloc.
1906 if (lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
)
1907 is_new
= got
->add_local_plt(object
, r_sym
, GOT_TYPE_STANDARD
);
1909 is_new
= got
->add_local(object
, r_sym
, GOT_TYPE_STANDARD
);
1912 // If we are generating a shared object, we need to add a
1913 // dynamic RELATIVE relocation for this symbol's GOT entry.
1914 if (parameters
->options().output_is_position_independent())
1916 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1917 unsigned int got_offset
=
1918 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
);
1919 rel_dyn
->add_local_relative(object
, r_sym
,
1920 elfcpp::R_386_RELATIVE
,
1927 // These are relocations which should only be seen by the
1928 // dynamic linker, and should never be seen here.
1929 case elfcpp::R_386_COPY
:
1930 case elfcpp::R_386_GLOB_DAT
:
1931 case elfcpp::R_386_JUMP_SLOT
:
1932 case elfcpp::R_386_RELATIVE
:
1933 case elfcpp::R_386_IRELATIVE
:
1934 case elfcpp::R_386_TLS_TPOFF
:
1935 case elfcpp::R_386_TLS_DTPMOD32
:
1936 case elfcpp::R_386_TLS_DTPOFF32
:
1937 case elfcpp::R_386_TLS_TPOFF32
:
1938 case elfcpp::R_386_TLS_DESC
:
1939 gold_error(_("%s: unexpected reloc %u in object file"),
1940 object
->name().c_str(), r_type
);
1943 // These are initial TLS relocs, which are expected when
1945 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1946 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1947 case elfcpp::R_386_TLS_DESC_CALL
:
1948 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1949 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1950 case elfcpp::R_386_TLS_IE
: // Initial-exec
1951 case elfcpp::R_386_TLS_IE_32
:
1952 case elfcpp::R_386_TLS_GOTIE
:
1953 case elfcpp::R_386_TLS_LE
: // Local-exec
1954 case elfcpp::R_386_TLS_LE_32
:
1956 bool output_is_shared
= parameters
->options().shared();
1957 const tls::Tls_optimization optimized_type
1958 = Target_i386::optimize_tls_reloc(!output_is_shared
, r_type
);
1961 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1962 if (optimized_type
== tls::TLSOPT_NONE
)
1964 // Create a pair of GOT entries for the module index and
1965 // dtv-relative offset.
1966 Output_data_got
<32, false>* got
1967 = target
->got_section(symtab
, layout
);
1968 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1969 unsigned int shndx
= lsym
.get_st_shndx();
1971 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
1973 object
->error(_("local symbol %u has bad shndx %u"),
1976 got
->add_local_pair_with_rel(object
, r_sym
, shndx
,
1978 target
->rel_dyn_section(layout
),
1979 elfcpp::R_386_TLS_DTPMOD32
);
1981 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1982 unsupported_reloc_local(object
, r_type
);
1985 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva)
1986 target
->define_tls_base_symbol(symtab
, layout
);
1987 if (optimized_type
== tls::TLSOPT_NONE
)
1989 // Create a double GOT entry with an R_386_TLS_DESC
1990 // reloc. The R_386_TLS_DESC reloc is resolved
1991 // lazily, so the GOT entry needs to be in an area in
1992 // .got.plt, not .got. Call got_section to make sure
1993 // the section has been created.
1994 target
->got_section(symtab
, layout
);
1995 Output_data_got
<32, false>* got
= target
->got_tlsdesc_section();
1996 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1997 if (!object
->local_has_got_offset(r_sym
, GOT_TYPE_TLS_DESC
))
1999 unsigned int got_offset
= got
->add_constant(0);
2000 // The local symbol value is stored in the second
2002 got
->add_local(object
, r_sym
, GOT_TYPE_TLS_DESC
);
2003 // That set the GOT offset of the local symbol to
2004 // point to the second entry, but we want it to
2005 // point to the first.
2006 object
->set_local_got_offset(r_sym
, GOT_TYPE_TLS_DESC
,
2008 Reloc_section
* rt
= target
->rel_tls_desc_section(layout
);
2009 rt
->add_absolute(elfcpp::R_386_TLS_DESC
, got
, got_offset
);
2012 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2013 unsupported_reloc_local(object
, r_type
);
2016 case elfcpp::R_386_TLS_DESC_CALL
:
2019 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2020 if (optimized_type
== tls::TLSOPT_NONE
)
2022 // Create a GOT entry for the module index.
2023 target
->got_mod_index_entry(symtab
, layout
, object
);
2025 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2026 unsupported_reloc_local(object
, r_type
);
2029 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2032 case elfcpp::R_386_TLS_IE
: // Initial-exec
2033 case elfcpp::R_386_TLS_IE_32
:
2034 case elfcpp::R_386_TLS_GOTIE
:
2035 layout
->set_has_static_tls();
2036 if (optimized_type
== tls::TLSOPT_NONE
)
2038 // For the R_386_TLS_IE relocation, we need to create a
2039 // dynamic relocation when building a shared library.
2040 if (r_type
== elfcpp::R_386_TLS_IE
2041 && parameters
->options().shared())
2043 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2045 = elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
2046 rel_dyn
->add_local_relative(object
, r_sym
,
2047 elfcpp::R_386_RELATIVE
,
2048 output_section
, data_shndx
,
2049 reloc
.get_r_offset());
2051 // Create a GOT entry for the tp-relative offset.
2052 Output_data_got
<32, false>* got
2053 = target
->got_section(symtab
, layout
);
2054 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
2055 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2056 ? elfcpp::R_386_TLS_TPOFF32
2057 : elfcpp::R_386_TLS_TPOFF
);
2058 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2059 ? GOT_TYPE_TLS_OFFSET
2060 : GOT_TYPE_TLS_NOFFSET
);
2061 got
->add_local_with_rel(object
, r_sym
, got_type
,
2062 target
->rel_dyn_section(layout
),
2065 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2066 unsupported_reloc_local(object
, r_type
);
2069 case elfcpp::R_386_TLS_LE
: // Local-exec
2070 case elfcpp::R_386_TLS_LE_32
:
2071 layout
->set_has_static_tls();
2072 if (output_is_shared
)
2074 // We need to create a dynamic relocation.
2075 gold_assert(lsym
.get_st_type() != elfcpp::STT_SECTION
);
2076 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
2077 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
2078 ? elfcpp::R_386_TLS_TPOFF32
2079 : elfcpp::R_386_TLS_TPOFF
);
2080 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2081 rel_dyn
->add_local(object
, r_sym
, dyn_r_type
, output_section
,
2082 data_shndx
, reloc
.get_r_offset());
2092 case elfcpp::R_386_32PLT
:
2093 case elfcpp::R_386_TLS_GD_32
:
2094 case elfcpp::R_386_TLS_GD_PUSH
:
2095 case elfcpp::R_386_TLS_GD_CALL
:
2096 case elfcpp::R_386_TLS_GD_POP
:
2097 case elfcpp::R_386_TLS_LDM_32
:
2098 case elfcpp::R_386_TLS_LDM_PUSH
:
2099 case elfcpp::R_386_TLS_LDM_CALL
:
2100 case elfcpp::R_386_TLS_LDM_POP
:
2101 case elfcpp::R_386_USED_BY_INTEL_200
:
2103 unsupported_reloc_local(object
, r_type
);
2108 // Report an unsupported relocation against a global symbol.
2111 Target_i386::Scan::unsupported_reloc_global(
2112 Sized_relobj_file
<32, false>* object
,
2113 unsigned int r_type
,
2116 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
2117 object
->name().c_str(), r_type
, gsym
->demangled_name().c_str());
2121 Target_i386::Scan::possible_function_pointer_reloc(unsigned int r_type
)
2125 case elfcpp::R_386_32
:
2126 case elfcpp::R_386_16
:
2127 case elfcpp::R_386_8
:
2128 case elfcpp::R_386_GOTOFF
:
2129 case elfcpp::R_386_GOT32
:
2130 case elfcpp::R_386_GOT32X
:
2141 Target_i386::Scan::local_reloc_may_be_function_pointer(
2145 Sized_relobj_file
<32, false>* ,
2148 const elfcpp::Rel
<32, false>& ,
2149 unsigned int r_type
,
2150 const elfcpp::Sym
<32, false>&)
2152 return possible_function_pointer_reloc(r_type
);
2156 Target_i386::Scan::global_reloc_may_be_function_pointer(
2160 Sized_relobj_file
<32, false>* ,
2163 const elfcpp::Rel
<32, false>& ,
2164 unsigned int r_type
,
2167 return possible_function_pointer_reloc(r_type
);
2170 // Scan a relocation for a global symbol.
2173 Target_i386::Scan::global(Symbol_table
* symtab
,
2175 Target_i386
* target
,
2176 Sized_relobj_file
<32, false>* object
,
2177 unsigned int data_shndx
,
2178 Output_section
* output_section
,
2179 const elfcpp::Rel
<32, false>& reloc
,
2180 unsigned int r_type
,
2183 // A STT_GNU_IFUNC symbol may require a PLT entry.
2184 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
2185 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
2186 target
->make_plt_entry(symtab
, layout
, gsym
);
2190 case elfcpp::R_386_NONE
:
2191 case elfcpp::R_386_GNU_VTINHERIT
:
2192 case elfcpp::R_386_GNU_VTENTRY
:
2195 case elfcpp::R_386_32
:
2196 case elfcpp::R_386_16
:
2197 case elfcpp::R_386_8
:
2199 // Make a PLT entry if necessary.
2200 if (gsym
->needs_plt_entry())
2202 target
->make_plt_entry(symtab
, layout
, gsym
);
2203 // Since this is not a PC-relative relocation, we may be
2204 // taking the address of a function. In that case we need to
2205 // set the entry in the dynamic symbol table to the address of
2207 if (gsym
->is_from_dynobj() && !parameters
->options().shared())
2208 gsym
->set_needs_dynsym_value();
2210 // Make a dynamic relocation if necessary.
2211 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
2213 if (!parameters
->options().output_is_position_independent()
2214 && gsym
->may_need_copy_reloc())
2216 target
->copy_reloc(symtab
, layout
, object
,
2217 data_shndx
, output_section
, gsym
, reloc
);
2219 else if (r_type
== elfcpp::R_386_32
2220 && gsym
->type() == elfcpp::STT_GNU_IFUNC
2221 && gsym
->can_use_relative_reloc(false)
2222 && !gsym
->is_from_dynobj()
2223 && !gsym
->is_undefined()
2224 && !gsym
->is_preemptible())
2226 // Use an IRELATIVE reloc for a locally defined
2227 // STT_GNU_IFUNC symbol. This makes a function
2228 // address in a PIE executable match the address in a
2229 // shared library that it links against.
2230 Reloc_section
* rel_dyn
= target
->rel_irelative_section(layout
);
2231 rel_dyn
->add_symbolless_global_addend(gsym
,
2232 elfcpp::R_386_IRELATIVE
,
2235 reloc
.get_r_offset());
2237 else if (r_type
== elfcpp::R_386_32
2238 && gsym
->can_use_relative_reloc(false))
2240 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2241 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
2242 output_section
, object
,
2243 data_shndx
, reloc
.get_r_offset());
2247 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2248 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
2249 data_shndx
, reloc
.get_r_offset());
2255 case elfcpp::R_386_PC32
:
2256 case elfcpp::R_386_PC16
:
2257 case elfcpp::R_386_PC8
:
2259 // Make a PLT entry if necessary.
2260 if (gsym
->needs_plt_entry())
2262 // These relocations are used for function calls only in
2263 // non-PIC code. For a 32-bit relocation in a shared library,
2264 // we'll need a text relocation anyway, so we can skip the
2265 // PLT entry and let the dynamic linker bind the call directly
2266 // to the target. For smaller relocations, we should use a
2267 // PLT entry to ensure that the call can reach.
2268 if (!parameters
->options().shared()
2269 || r_type
!= elfcpp::R_386_PC32
)
2270 target
->make_plt_entry(symtab
, layout
, gsym
);
2272 // Make a dynamic relocation if necessary.
2273 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
2275 if (parameters
->options().output_is_executable()
2276 && gsym
->may_need_copy_reloc())
2278 target
->copy_reloc(symtab
, layout
, object
,
2279 data_shndx
, output_section
, gsym
, reloc
);
2283 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2284 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
2285 data_shndx
, reloc
.get_r_offset());
2291 case elfcpp::R_386_GOT32
:
2292 case elfcpp::R_386_GOT32X
:
2294 // The symbol requires a GOT section.
2295 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
2297 // If we convert this from
2298 // mov foo@GOT(%reg), %reg
2300 // lea foo@GOTOFF(%reg), %reg
2301 // in Relocate::relocate, then there is nothing to do here.
2302 if (reloc
.get_r_offset() >= 2
2303 && Target_i386::can_convert_mov_to_lea(gsym
))
2305 section_size_type stype
;
2306 const unsigned char* view
= object
->section_contents(data_shndx
,
2308 if (view
[reloc
.get_r_offset() - 2] == 0x8b)
2312 if (gsym
->final_value_is_known())
2314 // For a STT_GNU_IFUNC symbol we want the PLT address.
2315 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
)
2316 got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
2318 got
->add_global(gsym
, GOT_TYPE_STANDARD
);
2322 // If this symbol is not fully resolved, we need to add a
2323 // GOT entry with a dynamic relocation.
2324 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2326 // Use a GLOB_DAT rather than a RELATIVE reloc if:
2328 // 1) The symbol may be defined in some other module.
2330 // 2) We are building a shared library and this is a
2331 // protected symbol; using GLOB_DAT means that the dynamic
2332 // linker can use the address of the PLT in the main
2333 // executable when appropriate so that function address
2334 // comparisons work.
2336 // 3) This is a STT_GNU_IFUNC symbol in position dependent
2337 // code, again so that function address comparisons work.
2338 if (gsym
->is_from_dynobj()
2339 || gsym
->is_undefined()
2340 || gsym
->is_preemptible()
2341 || (gsym
->visibility() == elfcpp::STV_PROTECTED
2342 && parameters
->options().shared())
2343 || (gsym
->type() == elfcpp::STT_GNU_IFUNC
2344 && parameters
->options().output_is_position_independent()))
2345 got
->add_global_with_rel(gsym
, GOT_TYPE_STANDARD
,
2346 rel_dyn
, elfcpp::R_386_GLOB_DAT
);
2349 // For a STT_GNU_IFUNC symbol we want to write the PLT
2350 // offset into the GOT, so that function pointer
2351 // comparisons work correctly.
2353 if (gsym
->type() != elfcpp::STT_GNU_IFUNC
)
2354 is_new
= got
->add_global(gsym
, GOT_TYPE_STANDARD
);
2357 is_new
= got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
2358 // Tell the dynamic linker to use the PLT address
2359 // when resolving relocations.
2360 if (gsym
->is_from_dynobj()
2361 && !parameters
->options().shared())
2362 gsym
->set_needs_dynsym_value();
2366 unsigned int got_off
= gsym
->got_offset(GOT_TYPE_STANDARD
);
2367 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
2375 case elfcpp::R_386_PLT32
:
2376 // If the symbol is fully resolved, this is just a PC32 reloc.
2377 // Otherwise we need a PLT entry.
2378 if (gsym
->final_value_is_known())
2380 // If building a shared library, we can also skip the PLT entry
2381 // if the symbol is defined in the output file and is protected
2383 if (gsym
->is_defined()
2384 && !gsym
->is_from_dynobj()
2385 && !gsym
->is_preemptible())
2387 target
->make_plt_entry(symtab
, layout
, gsym
);
2390 case elfcpp::R_386_GOTOFF
:
2391 case elfcpp::R_386_GOTPC
:
2392 // We need a GOT section.
2393 target
->got_section(symtab
, layout
);
2396 // These are relocations which should only be seen by the
2397 // dynamic linker, and should never be seen here.
2398 case elfcpp::R_386_COPY
:
2399 case elfcpp::R_386_GLOB_DAT
:
2400 case elfcpp::R_386_JUMP_SLOT
:
2401 case elfcpp::R_386_RELATIVE
:
2402 case elfcpp::R_386_IRELATIVE
:
2403 case elfcpp::R_386_TLS_TPOFF
:
2404 case elfcpp::R_386_TLS_DTPMOD32
:
2405 case elfcpp::R_386_TLS_DTPOFF32
:
2406 case elfcpp::R_386_TLS_TPOFF32
:
2407 case elfcpp::R_386_TLS_DESC
:
2408 gold_error(_("%s: unexpected reloc %u in object file"),
2409 object
->name().c_str(), r_type
);
2412 // These are initial tls relocs, which are expected when
2414 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2415 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2416 case elfcpp::R_386_TLS_DESC_CALL
:
2417 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2418 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2419 case elfcpp::R_386_TLS_IE
: // Initial-exec
2420 case elfcpp::R_386_TLS_IE_32
:
2421 case elfcpp::R_386_TLS_GOTIE
:
2422 case elfcpp::R_386_TLS_LE
: // Local-exec
2423 case elfcpp::R_386_TLS_LE_32
:
2425 const bool is_final
= gsym
->final_value_is_known();
2426 const tls::Tls_optimization optimized_type
2427 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
2430 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2431 if (optimized_type
== tls::TLSOPT_NONE
)
2433 // Create a pair of GOT entries for the module index and
2434 // dtv-relative offset.
2435 Output_data_got
<32, false>* got
2436 = target
->got_section(symtab
, layout
);
2437 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_PAIR
,
2438 target
->rel_dyn_section(layout
),
2439 elfcpp::R_386_TLS_DTPMOD32
,
2440 elfcpp::R_386_TLS_DTPOFF32
);
2442 else if (optimized_type
== tls::TLSOPT_TO_IE
)
2444 // Create a GOT entry for the tp-relative offset.
2445 Output_data_got
<32, false>* got
2446 = target
->got_section(symtab
, layout
);
2447 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
2448 target
->rel_dyn_section(layout
),
2449 elfcpp::R_386_TLS_TPOFF
);
2451 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2452 unsupported_reloc_global(object
, r_type
, gsym
);
2455 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (~oliva url)
2456 target
->define_tls_base_symbol(symtab
, layout
);
2457 if (optimized_type
== tls::TLSOPT_NONE
)
2459 // Create a double GOT entry with an R_386_TLS_DESC
2460 // reloc. The R_386_TLS_DESC reloc is resolved
2461 // lazily, so the GOT entry needs to be in an area in
2462 // .got.plt, not .got. Call got_section to make sure
2463 // the section has been created.
2464 target
->got_section(symtab
, layout
);
2465 Output_data_got
<32, false>* got
= target
->got_tlsdesc_section();
2466 Reloc_section
* rt
= target
->rel_tls_desc_section(layout
);
2467 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_DESC
, rt
,
2468 elfcpp::R_386_TLS_DESC
, 0);
2470 else if (optimized_type
== tls::TLSOPT_TO_IE
)
2472 // Create a GOT entry for the tp-relative offset.
2473 Output_data_got
<32, false>* got
2474 = target
->got_section(symtab
, layout
);
2475 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
2476 target
->rel_dyn_section(layout
),
2477 elfcpp::R_386_TLS_TPOFF
);
2479 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2480 unsupported_reloc_global(object
, r_type
, gsym
);
2483 case elfcpp::R_386_TLS_DESC_CALL
:
2486 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2487 if (optimized_type
== tls::TLSOPT_NONE
)
2489 // Create a GOT entry for the module index.
2490 target
->got_mod_index_entry(symtab
, layout
, object
);
2492 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2493 unsupported_reloc_global(object
, r_type
, gsym
);
2496 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2499 case elfcpp::R_386_TLS_IE
: // Initial-exec
2500 case elfcpp::R_386_TLS_IE_32
:
2501 case elfcpp::R_386_TLS_GOTIE
:
2502 layout
->set_has_static_tls();
2503 if (optimized_type
== tls::TLSOPT_NONE
)
2505 // For the R_386_TLS_IE relocation, we need to create a
2506 // dynamic relocation when building a shared library.
2507 if (r_type
== elfcpp::R_386_TLS_IE
2508 && parameters
->options().shared())
2510 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2511 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
2512 output_section
, object
,
2514 reloc
.get_r_offset());
2516 // Create a GOT entry for the tp-relative offset.
2517 Output_data_got
<32, false>* got
2518 = target
->got_section(symtab
, layout
);
2519 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2520 ? elfcpp::R_386_TLS_TPOFF32
2521 : elfcpp::R_386_TLS_TPOFF
);
2522 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2523 ? GOT_TYPE_TLS_OFFSET
2524 : GOT_TYPE_TLS_NOFFSET
);
2525 got
->add_global_with_rel(gsym
, got_type
,
2526 target
->rel_dyn_section(layout
),
2529 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2530 unsupported_reloc_global(object
, r_type
, gsym
);
2533 case elfcpp::R_386_TLS_LE
: // Local-exec
2534 case elfcpp::R_386_TLS_LE_32
:
2535 layout
->set_has_static_tls();
2536 if (parameters
->options().shared())
2538 // We need to create a dynamic relocation.
2539 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
2540 ? elfcpp::R_386_TLS_TPOFF32
2541 : elfcpp::R_386_TLS_TPOFF
);
2542 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2543 rel_dyn
->add_global(gsym
, dyn_r_type
, output_section
, object
,
2544 data_shndx
, reloc
.get_r_offset());
2554 case elfcpp::R_386_32PLT
:
2555 case elfcpp::R_386_TLS_GD_32
:
2556 case elfcpp::R_386_TLS_GD_PUSH
:
2557 case elfcpp::R_386_TLS_GD_CALL
:
2558 case elfcpp::R_386_TLS_GD_POP
:
2559 case elfcpp::R_386_TLS_LDM_32
:
2560 case elfcpp::R_386_TLS_LDM_PUSH
:
2561 case elfcpp::R_386_TLS_LDM_CALL
:
2562 case elfcpp::R_386_TLS_LDM_POP
:
2563 case elfcpp::R_386_USED_BY_INTEL_200
:
2565 unsupported_reloc_global(object
, r_type
, gsym
);
2570 // Process relocations for gc.
2573 Target_i386::gc_process_relocs(Symbol_table
* symtab
,
2575 Sized_relobj_file
<32, false>* object
,
2576 unsigned int data_shndx
,
2578 const unsigned char* prelocs
,
2580 Output_section
* output_section
,
2581 bool needs_special_offset_handling
,
2582 size_t local_symbol_count
,
2583 const unsigned char* plocal_symbols
)
2585 gold::gc_process_relocs
<32, false, Target_i386
, Scan
, Classify_reloc
>(
2594 needs_special_offset_handling
,
2599 // Scan relocations for a section.
2602 Target_i386::scan_relocs(Symbol_table
* symtab
,
2604 Sized_relobj_file
<32, false>* object
,
2605 unsigned int data_shndx
,
2606 unsigned int sh_type
,
2607 const unsigned char* prelocs
,
2609 Output_section
* output_section
,
2610 bool needs_special_offset_handling
,
2611 size_t local_symbol_count
,
2612 const unsigned char* plocal_symbols
)
2614 if (sh_type
== elfcpp::SHT_RELA
)
2616 gold_error(_("%s: unsupported RELA reloc section"),
2617 object
->name().c_str());
2621 gold::scan_relocs
<32, false, Target_i386
, Scan
, Classify_reloc
>(
2630 needs_special_offset_handling
,
2635 // Finalize the sections.
2638 Target_i386::do_finalize_sections(
2640 const Input_objects
*,
2641 Symbol_table
* symtab
)
2643 const Reloc_section
* rel_plt
= (this->plt_
== NULL
2645 : this->plt_
->rel_plt());
2646 layout
->add_target_dynamic_tags(true, this->got_plt_
, rel_plt
,
2647 this->rel_dyn_
, true, false);
2649 // Emit any relocs we saved in an attempt to avoid generating COPY
2651 if (this->copy_relocs_
.any_saved_relocs())
2652 this->copy_relocs_
.emit(this->rel_dyn_section(layout
));
2654 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
2655 // the .got.plt section.
2656 Symbol
* sym
= this->global_offset_table_
;
2659 uint32_t data_size
= this->got_plt_
->current_data_size();
2660 symtab
->get_sized_symbol
<32>(sym
)->set_symsize(data_size
);
2663 if (parameters
->doing_static_link()
2664 && (this->plt_
== NULL
|| !this->plt_
->has_irelative_section()))
2666 // If linking statically, make sure that the __rel_iplt symbols
2667 // were defined if necessary, even if we didn't create a PLT.
2668 static const Define_symbol_in_segment syms
[] =
2671 "__rel_iplt_start", // name
2672 elfcpp::PT_LOAD
, // segment_type
2673 elfcpp::PF_W
, // segment_flags_set
2674 elfcpp::PF(0), // segment_flags_clear
2677 elfcpp::STT_NOTYPE
, // type
2678 elfcpp::STB_GLOBAL
, // binding
2679 elfcpp::STV_HIDDEN
, // visibility
2681 Symbol::SEGMENT_START
, // offset_from_base
2685 "__rel_iplt_end", // name
2686 elfcpp::PT_LOAD
, // segment_type
2687 elfcpp::PF_W
, // segment_flags_set
2688 elfcpp::PF(0), // segment_flags_clear
2691 elfcpp::STT_NOTYPE
, // type
2692 elfcpp::STB_GLOBAL
, // binding
2693 elfcpp::STV_HIDDEN
, // visibility
2695 Symbol::SEGMENT_START
, // offset_from_base
2700 symtab
->define_symbols(layout
, 2, syms
,
2701 layout
->script_options()->saw_sections_clause());
2705 // Return whether a direct absolute static relocation needs to be applied.
2706 // In cases where Scan::local() or Scan::global() has created
2707 // a dynamic relocation other than R_386_RELATIVE, the addend
2708 // of the relocation is carried in the data, and we must not
2709 // apply the static relocation.
2712 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
2713 unsigned int r_type
,
2715 Output_section
* output_section
)
2717 // If the output section is not allocated, then we didn't call
2718 // scan_relocs, we didn't create a dynamic reloc, and we must apply
2720 if ((output_section
->flags() & elfcpp::SHF_ALLOC
) == 0)
2723 int ref_flags
= Scan::get_reference_flags(r_type
);
2725 // For local symbols, we will have created a non-RELATIVE dynamic
2726 // relocation only if (a) the output is position independent,
2727 // (b) the relocation is absolute (not pc- or segment-relative), and
2728 // (c) the relocation is not 32 bits wide.
2730 return !(parameters
->options().output_is_position_independent()
2731 && (ref_flags
& Symbol::ABSOLUTE_REF
)
2734 // For global symbols, we use the same helper routines used in the
2735 // scan pass. If we did not create a dynamic relocation, or if we
2736 // created a RELATIVE dynamic relocation, we should apply the static
2738 bool has_dyn
= gsym
->needs_dynamic_reloc(ref_flags
);
2739 bool is_rel
= (ref_flags
& Symbol::ABSOLUTE_REF
)
2740 && gsym
->can_use_relative_reloc(ref_flags
2741 & Symbol::FUNCTION_CALL
);
2742 return !has_dyn
|| is_rel
;
2745 // Perform a relocation.
2748 Target_i386::Relocate::relocate(const Relocate_info
<32, false>* relinfo
,
2750 Target_i386
* target
,
2751 Output_section
* output_section
,
2753 const unsigned char* preloc
,
2754 const Sized_symbol
<32>* gsym
,
2755 const Symbol_value
<32>* psymval
,
2756 unsigned char* view
,
2757 elfcpp::Elf_types
<32>::Elf_Addr address
,
2758 section_size_type view_size
)
2760 const elfcpp::Rel
<32, false> rel(preloc
);
2761 unsigned int r_type
= elfcpp::elf_r_type
<32>(rel
.get_r_info());
2763 if (this->skip_call_tls_get_addr_
)
2765 if ((r_type
!= elfcpp::R_386_PLT32
2766 && r_type
!= elfcpp::R_386_PC32
)
2768 || strcmp(gsym
->name(), "___tls_get_addr") != 0)
2769 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2770 _("missing expected TLS relocation"));
2773 this->skip_call_tls_get_addr_
= false;
2781 const Sized_relobj_file
<32, false>* object
= relinfo
->object
;
2783 // Pick the value to use for symbols defined in shared objects.
2784 Symbol_value
<32> symval
;
2786 && gsym
->type() == elfcpp::STT_GNU_IFUNC
2787 && r_type
== elfcpp::R_386_32
2788 && gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
))
2789 && gsym
->can_use_relative_reloc(false)
2790 && !gsym
->is_from_dynobj()
2791 && !gsym
->is_undefined()
2792 && !gsym
->is_preemptible())
2794 // In this case we are generating a R_386_IRELATIVE reloc. We
2795 // want to use the real value of the symbol, not the PLT offset.
2797 else if (gsym
!= NULL
2798 && gsym
->use_plt_offset(Scan::get_reference_flags(r_type
)))
2800 symval
.set_output_value(target
->plt_address_for_global(gsym
));
2803 else if (gsym
== NULL
&& psymval
->is_ifunc_symbol())
2805 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2806 if (object
->local_has_plt_offset(r_sym
))
2808 symval
.set_output_value(target
->plt_address_for_local(object
, r_sym
));
2817 case elfcpp::R_386_NONE
:
2818 case elfcpp::R_386_GNU_VTINHERIT
:
2819 case elfcpp::R_386_GNU_VTENTRY
:
2822 case elfcpp::R_386_32
:
2823 if (should_apply_static_reloc(gsym
, r_type
, true, output_section
))
2824 Relocate_functions
<32, false>::rel32(view
, object
, psymval
);
2827 case elfcpp::R_386_PC32
:
2828 if (should_apply_static_reloc(gsym
, r_type
, true, output_section
))
2829 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
2832 case elfcpp::R_386_16
:
2833 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2834 Relocate_functions
<32, false>::rel16(view
, object
, psymval
);
2837 case elfcpp::R_386_PC16
:
2838 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2839 Relocate_functions
<32, false>::pcrel16(view
, object
, psymval
, address
);
2842 case elfcpp::R_386_8
:
2843 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2844 Relocate_functions
<32, false>::rel8(view
, object
, psymval
);
2847 case elfcpp::R_386_PC8
:
2848 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2849 Relocate_functions
<32, false>::pcrel8(view
, object
, psymval
, address
);
2852 case elfcpp::R_386_PLT32
:
2853 gold_assert(gsym
== NULL
2854 || gsym
->has_plt_offset()
2855 || gsym
->final_value_is_known()
2856 || (gsym
->is_defined()
2857 && !gsym
->is_from_dynobj()
2858 && !gsym
->is_preemptible()));
2859 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
2862 case elfcpp::R_386_GOT32
:
2863 case elfcpp::R_386_GOT32X
:
2864 baseless
= (view
[-1] & 0xc7) == 0x5;
2865 // R_386_GOT32 and R_386_GOT32X don't work without base register
2866 // when generating a position-independent output file.
2868 && parameters
->options().output_is_position_independent())
2871 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2872 _("unexpected reloc %u against global symbol %s without base register in object file when generating a position-independent output file"),
2873 r_type
, gsym
->demangled_name().c_str());
2875 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2876 _("unexpected reloc %u against local symbol without base register in object file when generating a position-independent output file"),
2881 // mov foo@GOT(%reg), %reg
2883 // lea foo@GOTOFF(%reg), %reg
2885 if (rel
.get_r_offset() >= 2
2887 && ((gsym
== NULL
&& !psymval
->is_ifunc_symbol())
2889 && Target_i386::can_convert_mov_to_lea(gsym
))))
2892 elfcpp::Elf_types
<32>::Elf_Addr value
;
2893 value
= psymval
->value(object
, 0);
2894 // Don't subtract the .got.plt section address for baseless
2897 value
-= target
->got_plt_section()->address();
2898 Relocate_functions
<32, false>::rel32(view
, value
);
2902 // The GOT pointer points to the end of the GOT section.
2903 // We need to subtract the size of the GOT section to get
2904 // the actual offset to use in the relocation.
2905 unsigned int got_offset
= 0;
2908 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
2909 got_offset
= (gsym
->got_offset(GOT_TYPE_STANDARD
)
2910 - target
->got_size());
2914 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2915 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
2916 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
2917 - target
->got_size());
2919 // Add the .got.plt section address for baseless addressing.
2921 got_offset
+= target
->got_plt_section()->address();
2922 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2926 case elfcpp::R_386_GOTOFF
:
2928 elfcpp::Elf_types
<32>::Elf_Addr value
;
2929 value
= (psymval
->value(object
, 0)
2930 - target
->got_plt_section()->address());
2931 Relocate_functions
<32, false>::rel32(view
, value
);
2935 case elfcpp::R_386_GOTPC
:
2937 elfcpp::Elf_types
<32>::Elf_Addr value
;
2938 value
= target
->got_plt_section()->address();
2939 Relocate_functions
<32, false>::pcrel32(view
, value
, address
);
2943 case elfcpp::R_386_COPY
:
2944 case elfcpp::R_386_GLOB_DAT
:
2945 case elfcpp::R_386_JUMP_SLOT
:
2946 case elfcpp::R_386_RELATIVE
:
2947 case elfcpp::R_386_IRELATIVE
:
2948 // These are outstanding tls relocs, which are unexpected when
2950 case elfcpp::R_386_TLS_TPOFF
:
2951 case elfcpp::R_386_TLS_DTPMOD32
:
2952 case elfcpp::R_386_TLS_DTPOFF32
:
2953 case elfcpp::R_386_TLS_TPOFF32
:
2954 case elfcpp::R_386_TLS_DESC
:
2955 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2956 _("unexpected reloc %u in object file"),
2960 // These are initial tls relocs, which are expected when
2962 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2963 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2964 case elfcpp::R_386_TLS_DESC_CALL
:
2965 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2966 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2967 case elfcpp::R_386_TLS_IE
: // Initial-exec
2968 case elfcpp::R_386_TLS_IE_32
:
2969 case elfcpp::R_386_TLS_GOTIE
:
2970 case elfcpp::R_386_TLS_LE
: // Local-exec
2971 case elfcpp::R_386_TLS_LE_32
:
2972 this->relocate_tls(relinfo
, target
, relnum
, rel
, r_type
, gsym
, psymval
,
2973 view
, address
, view_size
);
2976 case elfcpp::R_386_32PLT
:
2977 case elfcpp::R_386_TLS_GD_32
:
2978 case elfcpp::R_386_TLS_GD_PUSH
:
2979 case elfcpp::R_386_TLS_GD_CALL
:
2980 case elfcpp::R_386_TLS_GD_POP
:
2981 case elfcpp::R_386_TLS_LDM_32
:
2982 case elfcpp::R_386_TLS_LDM_PUSH
:
2983 case elfcpp::R_386_TLS_LDM_CALL
:
2984 case elfcpp::R_386_TLS_LDM_POP
:
2985 case elfcpp::R_386_USED_BY_INTEL_200
:
2987 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2988 _("unsupported reloc %u"),
2996 // Perform a TLS relocation.
2999 Target_i386::Relocate::relocate_tls(const Relocate_info
<32, false>* relinfo
,
3000 Target_i386
* target
,
3002 const elfcpp::Rel
<32, false>& rel
,
3003 unsigned int r_type
,
3004 const Sized_symbol
<32>* gsym
,
3005 const Symbol_value
<32>* psymval
,
3006 unsigned char* view
,
3007 elfcpp::Elf_types
<32>::Elf_Addr
,
3008 section_size_type view_size
)
3010 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
3012 const Sized_relobj_file
<32, false>* object
= relinfo
->object
;
3014 elfcpp::Elf_types
<32>::Elf_Addr value
= psymval
->value(object
, 0);
3016 const bool is_final
= (gsym
== NULL
3017 ? !parameters
->options().shared()
3018 : gsym
->final_value_is_known());
3019 const tls::Tls_optimization optimized_type
3020 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
3023 case elfcpp::R_386_TLS_GD
: // Global-dynamic
3024 if (optimized_type
== tls::TLSOPT_TO_LE
)
3026 if (tls_segment
== NULL
)
3028 gold_assert(parameters
->errors()->error_count() > 0
3029 || issue_undefined_symbol_error(gsym
));
3032 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
3033 rel
, r_type
, value
, view
,
3039 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
3040 ? GOT_TYPE_TLS_NOFFSET
3041 : GOT_TYPE_TLS_PAIR
);
3042 unsigned int got_offset
;
3045 gold_assert(gsym
->has_got_offset(got_type
));
3046 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
3050 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
3051 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
3052 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
3053 - target
->got_size());
3055 if (optimized_type
== tls::TLSOPT_TO_IE
)
3057 this->tls_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
3058 got_offset
, view
, view_size
);
3061 else if (optimized_type
== tls::TLSOPT_NONE
)
3063 // Relocate the field with the offset of the pair of GOT
3065 Relocate_functions
<32, false>::rel32(view
, got_offset
);
3069 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3070 _("unsupported reloc %u"),
3074 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
3075 case elfcpp::R_386_TLS_DESC_CALL
:
3076 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
3077 if (optimized_type
== tls::TLSOPT_TO_LE
)
3079 if (tls_segment
== NULL
)
3081 gold_assert(parameters
->errors()->error_count() > 0
3082 || issue_undefined_symbol_error(gsym
));
3085 this->tls_desc_gd_to_le(relinfo
, relnum
, tls_segment
,
3086 rel
, r_type
, value
, view
,
3092 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
3093 ? GOT_TYPE_TLS_NOFFSET
3094 : GOT_TYPE_TLS_DESC
);
3095 unsigned int got_offset
= 0;
3096 if (r_type
== elfcpp::R_386_TLS_GOTDESC
3097 && optimized_type
== tls::TLSOPT_NONE
)
3099 // We created GOT entries in the .got.tlsdesc portion of
3100 // the .got.plt section, but the offset stored in the
3101 // symbol is the offset within .got.tlsdesc.
3102 got_offset
= (target
->got_size()
3103 + target
->got_plt_section()->data_size());
3107 gold_assert(gsym
->has_got_offset(got_type
));
3108 got_offset
+= gsym
->got_offset(got_type
) - target
->got_size();
3112 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
3113 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
3114 got_offset
+= (object
->local_got_offset(r_sym
, got_type
)
3115 - target
->got_size());
3117 if (optimized_type
== tls::TLSOPT_TO_IE
)
3119 if (tls_segment
== NULL
)
3121 gold_assert(parameters
->errors()->error_count() > 0
3122 || issue_undefined_symbol_error(gsym
));
3125 this->tls_desc_gd_to_ie(relinfo
, relnum
, tls_segment
, rel
, r_type
,
3126 got_offset
, view
, view_size
);
3129 else if (optimized_type
== tls::TLSOPT_NONE
)
3131 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
3133 // Relocate the field with the offset of the pair of GOT
3135 Relocate_functions
<32, false>::rel32(view
, got_offset
);
3140 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3141 _("unsupported reloc %u"),
3145 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
3146 if (this->local_dynamic_type_
== LOCAL_DYNAMIC_SUN
)
3148 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3149 _("both SUN and GNU model "
3150 "TLS relocations"));
3153 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
3154 if (optimized_type
== tls::TLSOPT_TO_LE
)
3156 if (tls_segment
== NULL
)
3158 gold_assert(parameters
->errors()->error_count() > 0
3159 || issue_undefined_symbol_error(gsym
));
3162 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rel
, r_type
,
3163 value
, view
, view_size
);
3166 else if (optimized_type
== tls::TLSOPT_NONE
)
3168 // Relocate the field with the offset of the GOT entry for
3169 // the module index.
3170 unsigned int got_offset
;
3171 got_offset
= (target
->got_mod_index_entry(NULL
, NULL
, NULL
)
3172 - target
->got_size());
3173 Relocate_functions
<32, false>::rel32(view
, got_offset
);
3176 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3177 _("unsupported reloc %u"),
3181 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
3182 if (optimized_type
== tls::TLSOPT_TO_LE
)
3184 // This reloc can appear in debugging sections, in which
3185 // case we must not convert to local-exec. We decide what
3186 // to do based on whether the section is marked as
3187 // containing executable code. That is what the GNU linker
3189 elfcpp::Shdr
<32, false> shdr(relinfo
->data_shdr
);
3190 if ((shdr
.get_sh_flags() & elfcpp::SHF_EXECINSTR
) != 0)
3192 if (tls_segment
== NULL
)
3194 gold_assert(parameters
->errors()->error_count() > 0
3195 || issue_undefined_symbol_error(gsym
));
3198 value
-= tls_segment
->memsz();
3201 Relocate_functions
<32, false>::rel32(view
, value
);
3204 case elfcpp::R_386_TLS_IE
: // Initial-exec
3205 case elfcpp::R_386_TLS_GOTIE
:
3206 case elfcpp::R_386_TLS_IE_32
:
3207 if (optimized_type
== tls::TLSOPT_TO_LE
)
3209 if (tls_segment
== NULL
)
3211 gold_assert(parameters
->errors()->error_count() > 0
3212 || issue_undefined_symbol_error(gsym
));
3215 Target_i386::Relocate::tls_ie_to_le(relinfo
, relnum
, tls_segment
,
3216 rel
, r_type
, value
, view
,
3220 else if (optimized_type
== tls::TLSOPT_NONE
)
3222 // Relocate the field with the offset of the GOT entry for
3223 // the tp-relative offset of the symbol.
3224 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
3225 ? GOT_TYPE_TLS_OFFSET
3226 : GOT_TYPE_TLS_NOFFSET
);
3227 unsigned int got_offset
;
3230 gold_assert(gsym
->has_got_offset(got_type
));
3231 got_offset
= gsym
->got_offset(got_type
);
3235 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
3236 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
3237 got_offset
= object
->local_got_offset(r_sym
, got_type
);
3239 // For the R_386_TLS_IE relocation, we need to apply the
3240 // absolute address of the GOT entry.
3241 if (r_type
== elfcpp::R_386_TLS_IE
)
3242 got_offset
+= target
->got_plt_section()->address();
3243 // All GOT offsets are relative to the end of the GOT.
3244 got_offset
-= target
->got_size();
3245 Relocate_functions
<32, false>::rel32(view
, got_offset
);
3248 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3249 _("unsupported reloc %u"),
3253 case elfcpp::R_386_TLS_LE
: // Local-exec
3254 // If we're creating a shared library, a dynamic relocation will
3255 // have been created for this location, so do not apply it now.
3256 if (!parameters
->options().shared())
3258 if (tls_segment
== NULL
)
3260 gold_assert(parameters
->errors()->error_count() > 0
3261 || issue_undefined_symbol_error(gsym
));
3264 value
-= tls_segment
->memsz();
3265 Relocate_functions
<32, false>::rel32(view
, value
);
3269 case elfcpp::R_386_TLS_LE_32
:
3270 // If we're creating a shared library, a dynamic relocation will
3271 // have been created for this location, so do not apply it now.
3272 if (!parameters
->options().shared())
3274 if (tls_segment
== NULL
)
3276 gold_assert(parameters
->errors()->error_count() > 0
3277 || issue_undefined_symbol_error(gsym
));
3280 value
= tls_segment
->memsz() - value
;
3281 Relocate_functions
<32, false>::rel32(view
, value
);
3287 // Do a relocation in which we convert a TLS General-Dynamic to a
3291 Target_i386::Relocate::tls_gd_to_le(const Relocate_info
<32, false>* relinfo
,
3293 Output_segment
* tls_segment
,
3294 const elfcpp::Rel
<32, false>& rel
,
3296 elfcpp::Elf_types
<32>::Elf_Addr value
,
3297 unsigned char* view
,
3298 section_size_type view_size
)
3300 // leal foo(,%reg,1),%eax; call ___tls_get_addr
3301 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
3302 // leal foo(%reg),%eax; call ___tls_get_addr
3303 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
3305 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3306 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
3308 unsigned char op1
= view
[-1];
3309 unsigned char op2
= view
[-2];
3311 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3312 op2
== 0x8d || op2
== 0x04);
3313 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
3319 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
3320 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
3321 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3322 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
3323 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3327 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3328 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
3329 if (rel
.get_r_offset() + 9 < view_size
3332 // There is a trailing nop. Use the size byte subl.
3333 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3338 // Use the five byte subl.
3339 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
3343 value
= tls_segment
->memsz() - value
;
3344 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
3346 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3348 this->skip_call_tls_get_addr_
= true;
3351 // Do a relocation in which we convert a TLS General-Dynamic to an
3355 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info
<32, false>* relinfo
,
3358 const elfcpp::Rel
<32, false>& rel
,
3360 elfcpp::Elf_types
<32>::Elf_Addr value
,
3361 unsigned char* view
,
3362 section_size_type view_size
)
3364 // leal foo(,%ebx,1),%eax; call ___tls_get_addr
3365 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
3366 // leal foo(%ebx),%eax; call ___tls_get_addr; nop
3367 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
3369 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3370 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
3372 unsigned char op1
= view
[-1];
3373 unsigned char op2
= view
[-2];
3375 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3376 op2
== 0x8d || op2
== 0x04);
3377 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
3383 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
3384 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
3385 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3386 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
3391 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 10);
3392 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3393 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
3394 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[9] == 0x90);
3398 memcpy(view
+ roff
- 8, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
3399 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
3401 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3403 this->skip_call_tls_get_addr_
= true;
3406 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3407 // General-Dynamic to a Local-Exec.
3410 Target_i386::Relocate::tls_desc_gd_to_le(
3411 const Relocate_info
<32, false>* relinfo
,
3413 Output_segment
* tls_segment
,
3414 const elfcpp::Rel
<32, false>& rel
,
3415 unsigned int r_type
,
3416 elfcpp::Elf_types
<32>::Elf_Addr value
,
3417 unsigned char* view
,
3418 section_size_type view_size
)
3420 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
3422 // leal foo@TLSDESC(%ebx), %eax
3423 // ==> leal foo@NTPOFF, %eax
3424 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3425 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3426 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3427 view
[-2] == 0x8d && view
[-1] == 0x83);
3429 value
-= tls_segment
->memsz();
3430 Relocate_functions
<32, false>::rel32(view
, value
);
3434 // call *foo@TLSCALL(%eax)
3436 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
3437 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
3438 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3439 view
[0] == 0xff && view
[1] == 0x10);
3445 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3446 // General-Dynamic to an Initial-Exec.
3449 Target_i386::Relocate::tls_desc_gd_to_ie(
3450 const Relocate_info
<32, false>* relinfo
,
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 // ==> movl foo@GOTNTPOFF(%ebx), %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 Relocate_functions
<32, false>::rel32(view
, value
);
3472 // call *foo@TLSCALL(%eax)
3474 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
3475 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
3476 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3477 view
[0] == 0xff && view
[1] == 0x10);
3483 // Do a relocation in which we convert a TLS Local-Dynamic to a
3487 Target_i386::Relocate::tls_ld_to_le(const Relocate_info
<32, false>* relinfo
,
3490 const elfcpp::Rel
<32, false>& rel
,
3492 elfcpp::Elf_types
<32>::Elf_Addr
,
3493 unsigned char* view
,
3494 section_size_type view_size
)
3496 // leal foo(%reg), %eax; call ___tls_get_addr
3497 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
3499 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3500 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
3502 // FIXME: Does this test really always pass?
3503 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3504 view
[-2] == 0x8d && view
[-1] == 0x83);
3506 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
3508 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
3510 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3512 this->skip_call_tls_get_addr_
= true;
3515 // Do a relocation in which we convert a TLS Initial-Exec to a
3519 Target_i386::Relocate::tls_ie_to_le(const Relocate_info
<32, false>* relinfo
,
3521 Output_segment
* tls_segment
,
3522 const elfcpp::Rel
<32, false>& rel
,
3523 unsigned int r_type
,
3524 elfcpp::Elf_types
<32>::Elf_Addr value
,
3525 unsigned char* view
,
3526 section_size_type view_size
)
3528 // We have to actually change the instructions, which means that we
3529 // need to examine the opcodes to figure out which instruction we
3531 if (r_type
== elfcpp::R_386_TLS_IE
)
3533 // movl %gs:XX,%eax ==> movl $YY,%eax
3534 // movl %gs:XX,%reg ==> movl $YY,%reg
3535 // addl %gs:XX,%reg ==> addl $YY,%reg
3536 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -1);
3537 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3539 unsigned char op1
= view
[-1];
3542 // movl XX,%eax ==> movl $YY,%eax
3547 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3549 unsigned char op2
= view
[-2];
3552 // movl XX,%reg ==> movl $YY,%reg
3553 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3554 (op1
& 0xc7) == 0x05);
3556 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3558 else if (op2
== 0x03)
3560 // addl XX,%reg ==> addl $YY,%reg
3561 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3562 (op1
& 0xc7) == 0x05);
3564 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3567 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
3572 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
3573 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
3574 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
3575 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3576 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3578 unsigned char op1
= view
[-1];
3579 unsigned char op2
= view
[-2];
3580 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3581 (op1
& 0xc0) == 0x80 && (op1
& 7) != 4);
3584 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
3586 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3588 else if (op2
== 0x2b)
3590 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
3592 view
[-1] = 0xe8 | ((op1
>> 3) & 7);
3594 else if (op2
== 0x03)
3596 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
3598 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3601 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
3604 value
= tls_segment
->memsz() - value
;
3605 if (r_type
== elfcpp::R_386_TLS_IE
|| r_type
== elfcpp::R_386_TLS_GOTIE
)
3608 Relocate_functions
<32, false>::rel32(view
, value
);
3611 // Relocate section data.
3614 Target_i386::relocate_section(const Relocate_info
<32, false>* relinfo
,
3615 unsigned int sh_type
,
3616 const unsigned char* prelocs
,
3618 Output_section
* output_section
,
3619 bool needs_special_offset_handling
,
3620 unsigned char* view
,
3621 elfcpp::Elf_types
<32>::Elf_Addr address
,
3622 section_size_type view_size
,
3623 const Reloc_symbol_changes
* reloc_symbol_changes
)
3625 gold_assert(sh_type
== elfcpp::SHT_REL
);
3627 gold::relocate_section
<32, false, Target_i386
, Relocate
,
3628 gold::Default_comdat_behavior
, Classify_reloc
>(
3634 needs_special_offset_handling
,
3638 reloc_symbol_changes
);
3641 // Return the size of a relocation while scanning during a relocatable
3645 Target_i386::Classify_reloc::get_size_for_reloc(
3646 unsigned int r_type
,
3651 case elfcpp::R_386_NONE
:
3652 case elfcpp::R_386_GNU_VTINHERIT
:
3653 case elfcpp::R_386_GNU_VTENTRY
:
3654 case elfcpp::R_386_TLS_GD
: // Global-dynamic
3655 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
3656 case elfcpp::R_386_TLS_DESC_CALL
:
3657 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
3658 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
3659 case elfcpp::R_386_TLS_IE
: // Initial-exec
3660 case elfcpp::R_386_TLS_IE_32
:
3661 case elfcpp::R_386_TLS_GOTIE
:
3662 case elfcpp::R_386_TLS_LE
: // Local-exec
3663 case elfcpp::R_386_TLS_LE_32
:
3666 case elfcpp::R_386_32
:
3667 case elfcpp::R_386_PC32
:
3668 case elfcpp::R_386_GOT32
:
3669 case elfcpp::R_386_GOT32X
:
3670 case elfcpp::R_386_PLT32
:
3671 case elfcpp::R_386_GOTOFF
:
3672 case elfcpp::R_386_GOTPC
:
3675 case elfcpp::R_386_16
:
3676 case elfcpp::R_386_PC16
:
3679 case elfcpp::R_386_8
:
3680 case elfcpp::R_386_PC8
:
3683 // These are relocations which should only be seen by the
3684 // dynamic linker, and should never be seen here.
3685 case elfcpp::R_386_COPY
:
3686 case elfcpp::R_386_GLOB_DAT
:
3687 case elfcpp::R_386_JUMP_SLOT
:
3688 case elfcpp::R_386_RELATIVE
:
3689 case elfcpp::R_386_IRELATIVE
:
3690 case elfcpp::R_386_TLS_TPOFF
:
3691 case elfcpp::R_386_TLS_DTPMOD32
:
3692 case elfcpp::R_386_TLS_DTPOFF32
:
3693 case elfcpp::R_386_TLS_TPOFF32
:
3694 case elfcpp::R_386_TLS_DESC
:
3695 object
->error(_("unexpected reloc %u in object file"), r_type
);
3698 case elfcpp::R_386_32PLT
:
3699 case elfcpp::R_386_TLS_GD_32
:
3700 case elfcpp::R_386_TLS_GD_PUSH
:
3701 case elfcpp::R_386_TLS_GD_CALL
:
3702 case elfcpp::R_386_TLS_GD_POP
:
3703 case elfcpp::R_386_TLS_LDM_32
:
3704 case elfcpp::R_386_TLS_LDM_PUSH
:
3705 case elfcpp::R_386_TLS_LDM_CALL
:
3706 case elfcpp::R_386_TLS_LDM_POP
:
3707 case elfcpp::R_386_USED_BY_INTEL_200
:
3709 object
->error(_("unsupported reloc %u in object file"), r_type
);
3714 // Scan the relocs during a relocatable link.
3717 Target_i386::scan_relocatable_relocs(Symbol_table
* symtab
,
3719 Sized_relobj_file
<32, false>* object
,
3720 unsigned int data_shndx
,
3721 unsigned int sh_type
,
3722 const unsigned char* prelocs
,
3724 Output_section
* output_section
,
3725 bool needs_special_offset_handling
,
3726 size_t local_symbol_count
,
3727 const unsigned char* plocal_symbols
,
3728 Relocatable_relocs
* rr
)
3730 typedef gold::Default_scan_relocatable_relocs
<Classify_reloc
>
3731 Scan_relocatable_relocs
;
3733 gold_assert(sh_type
== elfcpp::SHT_REL
);
3735 gold::scan_relocatable_relocs
<32, false, Scan_relocatable_relocs
>(
3743 needs_special_offset_handling
,
3749 // Scan the relocs for --emit-relocs.
3752 Target_i386::emit_relocs_scan(Symbol_table
* symtab
,
3754 Sized_relobj_file
<32, false>* object
,
3755 unsigned int data_shndx
,
3756 unsigned int sh_type
,
3757 const unsigned char* prelocs
,
3759 Output_section
* output_section
,
3760 bool needs_special_offset_handling
,
3761 size_t local_symbol_count
,
3762 const unsigned char* plocal_syms
,
3763 Relocatable_relocs
* rr
)
3765 typedef gold::Default_classify_reloc
<elfcpp::SHT_REL
, 32, false>
3767 typedef gold::Default_emit_relocs_strategy
<Classify_reloc
>
3768 Emit_relocs_strategy
;
3770 gold_assert(sh_type
== elfcpp::SHT_REL
);
3772 gold::scan_relocatable_relocs
<32, false, Emit_relocs_strategy
>(
3780 needs_special_offset_handling
,
3786 // Emit relocations for a section.
3789 Target_i386::relocate_relocs(
3790 const Relocate_info
<32, false>* relinfo
,
3791 unsigned int sh_type
,
3792 const unsigned char* prelocs
,
3794 Output_section
* output_section
,
3795 elfcpp::Elf_types
<32>::Elf_Off offset_in_output_section
,
3796 unsigned char* view
,
3797 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
3798 section_size_type view_size
,
3799 unsigned char* reloc_view
,
3800 section_size_type reloc_view_size
)
3802 gold_assert(sh_type
== elfcpp::SHT_REL
);
3804 gold::relocate_relocs
<32, false, Classify_reloc
>(
3809 offset_in_output_section
,
3817 // Return the value to use for a dynamic which requires special
3818 // treatment. This is how we support equality comparisons of function
3819 // pointers across shared library boundaries, as described in the
3820 // processor specific ABI supplement.
3823 Target_i386::do_dynsym_value(const Symbol
* gsym
) const
3825 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
3826 return this->plt_address_for_global(gsym
);
3829 // Return a string used to fill a code section with nops to take up
3830 // the specified length.
3833 Target_i386::do_code_fill(section_size_type length
) const
3837 // Build a jmp instruction to skip over the bytes.
3838 unsigned char jmp
[5];
3840 elfcpp::Swap_unaligned
<32, false>::writeval(jmp
+ 1, length
- 5);
3841 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
3842 + std::string(length
- 5, static_cast<char>(0x90)));
3845 // Nop sequences of various lengths.
3846 const char nop1
[1] = { '\x90' }; // nop
3847 const char nop2
[2] = { '\x66', '\x90' }; // xchg %ax %ax
3848 const char nop3
[3] = { '\x8d', '\x76', '\x00' }; // leal 0(%esi),%esi
3849 const char nop4
[4] = { '\x8d', '\x74', '\x26', // leal 0(%esi,1),%esi
3851 const char nop5
[5] = { '\x90', '\x8d', '\x74', // nop
3852 '\x26', '\x00' }; // leal 0(%esi,1),%esi
3853 const char nop6
[6] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3854 '\x00', '\x00', '\x00' };
3855 const char nop7
[7] = { '\x8d', '\xb4', '\x26', // leal 0L(%esi,1),%esi
3856 '\x00', '\x00', '\x00',
3858 const char nop8
[8] = { '\x90', '\x8d', '\xb4', // nop
3859 '\x26', '\x00', '\x00', // leal 0L(%esi,1),%esi
3861 const char nop9
[9] = { '\x89', '\xf6', '\x8d', // movl %esi,%esi
3862 '\xbc', '\x27', '\x00', // leal 0L(%edi,1),%edi
3863 '\x00', '\x00', '\x00' };
3864 const char nop10
[10] = { '\x8d', '\x76', '\x00', // leal 0(%esi),%esi
3865 '\x8d', '\xbc', '\x27', // leal 0L(%edi,1),%edi
3866 '\x00', '\x00', '\x00',
3868 const char nop11
[11] = { '\x8d', '\x74', '\x26', // leal 0(%esi,1),%esi
3869 '\x00', '\x8d', '\xbc', // leal 0L(%edi,1),%edi
3870 '\x27', '\x00', '\x00',
3872 const char nop12
[12] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3873 '\x00', '\x00', '\x00', // leal 0L(%edi),%edi
3874 '\x8d', '\xbf', '\x00',
3875 '\x00', '\x00', '\x00' };
3876 const char nop13
[13] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3877 '\x00', '\x00', '\x00', // leal 0L(%edi,1),%edi
3878 '\x8d', '\xbc', '\x27',
3879 '\x00', '\x00', '\x00',
3881 const char nop14
[14] = { '\x8d', '\xb4', '\x26', // leal 0L(%esi,1),%esi
3882 '\x00', '\x00', '\x00', // leal 0L(%edi,1),%edi
3883 '\x00', '\x8d', '\xbc',
3884 '\x27', '\x00', '\x00',
3886 const char nop15
[15] = { '\xeb', '\x0d', '\x90', // jmp .+15
3887 '\x90', '\x90', '\x90', // nop,nop,nop,...
3888 '\x90', '\x90', '\x90',
3889 '\x90', '\x90', '\x90',
3890 '\x90', '\x90', '\x90' };
3892 const char* nops
[16] = {
3894 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
3895 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
3898 return std::string(nops
[length
], length
);
3901 // Return the value to use for the base of a DW_EH_PE_datarel offset
3902 // in an FDE. Solaris and SVR4 use DW_EH_PE_datarel because their
3903 // assembler can not write out the difference between two labels in
3904 // different sections, so instead of using a pc-relative value they
3905 // use an offset from the GOT.
3908 Target_i386::do_ehframe_datarel_base() const
3910 gold_assert(this->global_offset_table_
!= NULL
);
3911 Symbol
* sym
= this->global_offset_table_
;
3912 Sized_symbol
<32>* ssym
= static_cast<Sized_symbol
<32>*>(sym
);
3913 return ssym
->value();
3916 // Return whether SYM should be treated as a call to a non-split
3917 // function. We don't want that to be true of a call to a
3918 // get_pc_thunk function.
3921 Target_i386::do_is_call_to_non_split(const Symbol
* sym
,
3922 const unsigned char*) const
3924 return (sym
->type() == elfcpp::STT_FUNC
3925 && !is_prefix_of("__i686.get_pc_thunk.", sym
->name()));
3928 // FNOFFSET in section SHNDX in OBJECT is the start of a function
3929 // compiled with -fsplit-stack. The function calls non-split-stack
3930 // code. We have to change the function so that it always ensures
3931 // that it has enough stack space to run some random function.
3934 Target_i386::do_calls_non_split(Relobj
* object
, unsigned int shndx
,
3935 section_offset_type fnoffset
,
3936 section_size_type fnsize
,
3937 const unsigned char*,
3939 unsigned char* view
,
3940 section_size_type view_size
,
3942 std::string
* to
) const
3944 // The function starts with a comparison of the stack pointer and a
3945 // field in the TCB. This is followed by a jump.
3948 if (this->match_view(view
, view_size
, fnoffset
, "\x65\x3b\x25", 3)
3951 // We will call __morestack if the carry flag is set after this
3952 // comparison. We turn the comparison into an stc instruction
3954 view
[fnoffset
] = '\xf9';
3955 this->set_view_to_nop(view
, view_size
, fnoffset
+ 1, 6);
3957 // lea NN(%esp),%ecx
3958 // lea NN(%esp),%edx
3959 else if ((this->match_view(view
, view_size
, fnoffset
, "\x8d\x8c\x24", 3)
3960 || this->match_view(view
, view_size
, fnoffset
, "\x8d\x94\x24", 3))
3963 // This is loading an offset from the stack pointer for a
3964 // comparison. The offset is negative, so we decrease the
3965 // offset by the amount of space we need for the stack. This
3966 // means we will avoid calling __morestack if there happens to
3967 // be plenty of space on the stack already.
3968 unsigned char* pval
= view
+ fnoffset
+ 3;
3969 uint32_t val
= elfcpp::Swap_unaligned
<32, false>::readval(pval
);
3970 val
-= parameters
->options().split_stack_adjust_size();
3971 elfcpp::Swap_unaligned
<32, false>::writeval(pval
, val
);
3975 if (!object
->has_no_split_stack())
3976 object
->error(_("failed to match split-stack sequence at "
3977 "section %u offset %0zx"),
3978 shndx
, static_cast<size_t>(fnoffset
));
3982 // We have to change the function so that it calls
3983 // __morestack_non_split instead of __morestack. The former will
3984 // allocate additional stack space.
3985 *from
= "__morestack";
3986 *to
= "__morestack_non_split";
3989 // The selector for i386 object files. Note this is never instantiated
3990 // directly. It's only used in Target_selector_i386_nacl, below.
3992 class Target_selector_i386
: public Target_selector_freebsd
3995 Target_selector_i386()
3996 : Target_selector_freebsd(elfcpp::EM_386
, 32, false,
3997 "elf32-i386", "elf32-i386-freebsd",
4002 do_instantiate_target()
4003 { return new Target_i386(); }
4006 // NaCl variant. It uses different PLT contents.
4008 class Output_data_plt_i386_nacl
: public Output_data_plt_i386
4011 Output_data_plt_i386_nacl(Layout
* layout
,
4012 Output_data_got_plt_i386
* got_plt
,
4013 Output_data_space
* got_irelative
)
4014 : Output_data_plt_i386(layout
, plt_entry_size
, got_plt
, got_irelative
)
4018 virtual unsigned int
4019 do_get_plt_entry_size() const
4020 { return plt_entry_size
; }
4023 do_add_eh_frame(Layout
* layout
)
4025 layout
->add_eh_frame_for_plt(this, plt_eh_frame_cie
, plt_eh_frame_cie_size
,
4026 plt_eh_frame_fde
, plt_eh_frame_fde_size
);
4029 // The size of an entry in the PLT.
4030 static const int plt_entry_size
= 64;
4032 // The .eh_frame unwind information for the PLT.
4033 static const int plt_eh_frame_fde_size
= 32;
4034 static const unsigned char plt_eh_frame_fde
[plt_eh_frame_fde_size
];
4037 class Output_data_plt_i386_nacl_exec
: public Output_data_plt_i386_nacl
4040 Output_data_plt_i386_nacl_exec(Layout
* layout
,
4041 Output_data_got_plt_i386
* got_plt
,
4042 Output_data_space
* got_irelative
)
4043 : Output_data_plt_i386_nacl(layout
, got_plt
, got_irelative
)
4048 do_fill_first_plt_entry(unsigned char* pov
,
4049 elfcpp::Elf_types
<32>::Elf_Addr got_address
);
4051 virtual unsigned int
4052 do_fill_plt_entry(unsigned char* pov
,
4053 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
4054 unsigned int got_offset
,
4055 unsigned int plt_offset
,
4056 unsigned int plt_rel_offset
);
4059 // The first entry in the PLT for an executable.
4060 static const unsigned char first_plt_entry
[plt_entry_size
];
4062 // Other entries in the PLT for an executable.
4063 static const unsigned char plt_entry
[plt_entry_size
];
4066 class Output_data_plt_i386_nacl_dyn
: public Output_data_plt_i386_nacl
4069 Output_data_plt_i386_nacl_dyn(Layout
* layout
,
4070 Output_data_got_plt_i386
* got_plt
,
4071 Output_data_space
* got_irelative
)
4072 : Output_data_plt_i386_nacl(layout
, got_plt
, got_irelative
)
4077 do_fill_first_plt_entry(unsigned char* pov
, elfcpp::Elf_types
<32>::Elf_Addr
);
4079 virtual unsigned int
4080 do_fill_plt_entry(unsigned char* pov
,
4081 elfcpp::Elf_types
<32>::Elf_Addr
,
4082 unsigned int got_offset
,
4083 unsigned int plt_offset
,
4084 unsigned int plt_rel_offset
);
4087 // The first entry in the PLT for a shared object.
4088 static const unsigned char first_plt_entry
[plt_entry_size
];
4090 // Other entries in the PLT for a shared object.
4091 static const unsigned char plt_entry
[plt_entry_size
];
4094 class Target_i386_nacl
: public Target_i386
4098 : Target_i386(&i386_nacl_info
)
4102 virtual Output_data_plt_i386
*
4103 do_make_data_plt(Layout
* layout
,
4104 Output_data_got_plt_i386
* got_plt
,
4105 Output_data_space
* got_irelative
,
4109 return new Output_data_plt_i386_nacl_dyn(layout
, got_plt
, got_irelative
);
4111 return new Output_data_plt_i386_nacl_exec(layout
, got_plt
, got_irelative
);
4115 do_code_fill(section_size_type length
) const;
4118 static const Target::Target_info i386_nacl_info
;
4121 const Target::Target_info
Target_i386_nacl::i386_nacl_info
=
4124 false, // is_big_endian
4125 elfcpp::EM_386
, // machine_code
4126 false, // has_make_symbol
4127 false, // has_resolve
4128 true, // has_code_fill
4129 true, // is_default_stack_executable
4130 true, // can_icf_inline_merge_sections
4132 "/lib/ld-nacl-x86-32.so.1", // dynamic_linker
4133 0x20000, // default_text_segment_address
4134 0x10000, // abi_pagesize (overridable by -z max-page-size)
4135 0x10000, // common_pagesize (overridable by -z common-page-size)
4136 true, // isolate_execinstr
4137 0x10000000, // rosegment_gap
4138 elfcpp::SHN_UNDEF
, // small_common_shndx
4139 elfcpp::SHN_UNDEF
, // large_common_shndx
4140 0, // small_common_section_flags
4141 0, // large_common_section_flags
4142 NULL
, // attributes_section
4143 NULL
, // attributes_vendor
4144 "_start", // entry_symbol_name
4145 32, // hash_entry_size
4148 #define NACLMASK 0xe0 // 32-byte alignment mask
4151 Output_data_plt_i386_nacl_exec::first_plt_entry
[plt_entry_size
] =
4153 0xff, 0x35, // pushl contents of memory address
4154 0, 0, 0, 0, // replaced with address of .got + 4
4155 0x8b, 0x0d, // movl contents of address, %ecx
4156 0, 0, 0, 0, // replaced with address of .got + 8
4157 0x83, 0xe1, NACLMASK
, // andl $NACLMASK, %ecx
4158 0xff, 0xe1, // jmp *%ecx
4159 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4160 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4161 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4162 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4163 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4164 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4165 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4166 0x90, 0x90, 0x90, 0x90, 0x90
4170 Output_data_plt_i386_nacl_exec::do_fill_first_plt_entry(
4172 elfcpp::Elf_types
<32>::Elf_Addr got_address
)
4174 memcpy(pov
, first_plt_entry
, plt_entry_size
);
4175 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 4);
4176 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 8);
4179 // The first entry in the PLT for a shared object.
4182 Output_data_plt_i386_nacl_dyn::first_plt_entry
[plt_entry_size
] =
4184 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
4185 0x8b, 0x4b, 0x08, // mov 0x8(%ebx), %ecx
4186 0x83, 0xe1, NACLMASK
, // andl $NACLMASK, %ecx
4187 0xff, 0xe1, // jmp *%ecx
4188 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4189 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4190 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4191 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4192 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4193 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4194 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4195 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4196 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4197 0x90, 0x90, 0x90, 0x90, 0x90 // nops
4201 Output_data_plt_i386_nacl_dyn::do_fill_first_plt_entry(
4203 elfcpp::Elf_types
<32>::Elf_Addr
)
4205 memcpy(pov
, first_plt_entry
, plt_entry_size
);
4208 // Subsequent entries in the PLT for an executable.
4211 Output_data_plt_i386_nacl_exec::plt_entry
[plt_entry_size
] =
4213 0x8b, 0x0d, // movl contents of address, %ecx */
4214 0, 0, 0, 0, // replaced with address of symbol in .got
4215 0x83, 0xe1, NACLMASK
, // andl $NACLMASK, %ecx
4216 0xff, 0xe1, // jmp *%ecx
4218 // Pad to the next 32-byte boundary with nop instructions.
4220 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4221 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4223 // Lazy GOT entries point here (32-byte aligned).
4224 0x68, // pushl immediate
4225 0, 0, 0, 0, // replaced with offset into relocation table
4226 0xe9, // jmp relative
4227 0, 0, 0, 0, // replaced with offset to start of .plt
4229 // Pad to the next 32-byte boundary with nop instructions.
4230 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4231 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4236 Output_data_plt_i386_nacl_exec::do_fill_plt_entry(
4238 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
4239 unsigned int got_offset
,
4240 unsigned int plt_offset
,
4241 unsigned int plt_rel_offset
)
4243 memcpy(pov
, plt_entry
, plt_entry_size
);
4244 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
4245 got_address
+ got_offset
);
4246 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 33, plt_rel_offset
);
4247 elfcpp::Swap
<32, false>::writeval(pov
+ 38, - (plt_offset
+ 38 + 4));
4251 // Subsequent entries in the PLT for a shared object.
4254 Output_data_plt_i386_nacl_dyn::plt_entry
[plt_entry_size
] =
4256 0x8b, 0x8b, // movl offset(%ebx), %ecx
4257 0, 0, 0, 0, // replaced with offset of symbol in .got
4258 0x83, 0xe1, 0xe0, // andl $NACLMASK, %ecx
4259 0xff, 0xe1, // jmp *%ecx
4261 // Pad to the next 32-byte boundary with nop instructions.
4263 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4264 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4266 // Lazy GOT entries point here (32-byte aligned).
4267 0x68, // pushl immediate
4268 0, 0, 0, 0, // replaced with offset into relocation table.
4269 0xe9, // jmp relative
4270 0, 0, 0, 0, // replaced with offset to start of .plt.
4272 // Pad to the next 32-byte boundary with nop instructions.
4273 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4274 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4279 Output_data_plt_i386_nacl_dyn::do_fill_plt_entry(
4281 elfcpp::Elf_types
<32>::Elf_Addr
,
4282 unsigned int got_offset
,
4283 unsigned int plt_offset
,
4284 unsigned int plt_rel_offset
)
4286 memcpy(pov
, plt_entry
, plt_entry_size
);
4287 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
4288 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 33, plt_rel_offset
);
4289 elfcpp::Swap
<32, false>::writeval(pov
+ 38, - (plt_offset
+ 38 + 4));
4294 Output_data_plt_i386_nacl::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
4296 0, 0, 0, 0, // Replaced with offset to .plt.
4297 0, 0, 0, 0, // Replaced with size of .plt.
4298 0, // Augmentation size.
4299 elfcpp::DW_CFA_def_cfa_offset
, 8, // DW_CFA_def_cfa_offset: 8.
4300 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
4301 elfcpp::DW_CFA_def_cfa_offset
, 12, // DW_CFA_def_cfa_offset: 12.
4302 elfcpp::DW_CFA_advance_loc
+ 58, // Advance 58 to __PLT__ + 64.
4303 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
4304 13, // Block length.
4305 elfcpp::DW_OP_breg4
, 4, // Push %esp + 4.
4306 elfcpp::DW_OP_breg8
, 0, // Push %eip.
4307 elfcpp::DW_OP_const1u
, 63, // Push 0x3f.
4308 elfcpp::DW_OP_and
, // & (%eip & 0x3f).
4309 elfcpp::DW_OP_const1u
, 37, // Push 0x25.
4310 elfcpp::DW_OP_ge
, // >= ((%eip & 0x3f) >= 0x25)
4311 elfcpp::DW_OP_lit2
, // Push 2.
4312 elfcpp::DW_OP_shl
, // << (((%eip & 0x3f) >= 0x25) << 2)
4313 elfcpp::DW_OP_plus
, // + ((((%eip&0x3f)>=0x25)<<2)+%esp+4
4314 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
4318 // Return a string used to fill a code section with nops.
4319 // For NaCl, long NOPs are only valid if they do not cross
4320 // bundle alignment boundaries, so keep it simple with one-byte NOPs.
4322 Target_i386_nacl::do_code_fill(section_size_type length
) const
4324 return std::string(length
, static_cast<char>(0x90));
4327 // The selector for i386-nacl object files.
4329 class Target_selector_i386_nacl
4330 : public Target_selector_nacl
<Target_selector_i386
, Target_i386_nacl
>
4333 Target_selector_i386_nacl()
4334 : Target_selector_nacl
<Target_selector_i386
,
4335 Target_i386_nacl
>("x86-32",
4341 Target_selector_i386_nacl target_selector_i386
;
4343 // IAMCU variant. It uses EM_IAMCU, not EM_386.
4345 class Target_iamcu
: public Target_i386
4349 : Target_i386(&iamcu_info
)
4353 // Information about this specific target which we pass to the
4354 // general Target structure.
4355 static const Target::Target_info iamcu_info
;
4358 const Target::Target_info
Target_iamcu::iamcu_info
=
4361 false, // is_big_endian
4362 elfcpp::EM_IAMCU
, // machine_code
4363 false, // has_make_symbol
4364 false, // has_resolve
4365 true, // has_code_fill
4366 true, // is_default_stack_executable
4367 true, // can_icf_inline_merge_sections
4369 "/usr/lib/libc.so.1", // dynamic_linker
4370 0x08048000, // default_text_segment_address
4371 0x1000, // abi_pagesize (overridable by -z max-page-size)
4372 0x1000, // common_pagesize (overridable by -z common-page-size)
4373 false, // isolate_execinstr
4375 elfcpp::SHN_UNDEF
, // small_common_shndx
4376 elfcpp::SHN_UNDEF
, // large_common_shndx
4377 0, // small_common_section_flags
4378 0, // large_common_section_flags
4379 NULL
, // attributes_section
4380 NULL
, // attributes_vendor
4381 "_start", // entry_symbol_name
4382 32, // hash_entry_size
4385 class Target_selector_iamcu
: public Target_selector
4388 Target_selector_iamcu()
4389 : Target_selector(elfcpp::EM_IAMCU
, 32, false, "elf32-iamcu",
4394 do_instantiate_target()
4395 { return new Target_iamcu(); }
4398 Target_selector_iamcu target_selector_iamcu
;
4400 } // End anonymous namespace.