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 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
672 elfcpp::Elf_types
<32>::Elf_Addr value
,
674 section_size_type view_size
);
676 // Do a TLS General-Dynamic to Local-Exec transition.
678 tls_gd_to_le(const Relocate_info
<32, false>*, size_t relnum
,
679 Output_segment
* tls_segment
,
680 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
681 elfcpp::Elf_types
<32>::Elf_Addr value
,
683 section_size_type view_size
);
685 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
688 tls_desc_gd_to_ie(const Relocate_info
<32, false>*, size_t relnum
,
689 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
690 elfcpp::Elf_types
<32>::Elf_Addr value
,
692 section_size_type view_size
);
694 // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
697 tls_desc_gd_to_le(const Relocate_info
<32, false>*, size_t relnum
,
698 Output_segment
* tls_segment
,
699 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
700 elfcpp::Elf_types
<32>::Elf_Addr value
,
702 section_size_type view_size
);
704 // Do a TLS Local-Dynamic to Local-Exec transition.
706 tls_ld_to_le(const Relocate_info
<32, false>*, size_t relnum
,
707 Output_segment
* tls_segment
,
708 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
709 elfcpp::Elf_types
<32>::Elf_Addr value
,
711 section_size_type view_size
);
713 // Do a TLS Initial-Exec to Local-Exec transition.
715 tls_ie_to_le(const Relocate_info
<32, false>*, size_t relnum
,
716 Output_segment
* tls_segment
,
717 const elfcpp::Rel
<32, false>&, unsigned int r_type
,
718 elfcpp::Elf_types
<32>::Elf_Addr value
,
720 section_size_type view_size
);
722 // We need to keep track of which type of local dynamic relocation
723 // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
724 enum Local_dynamic_type
731 // This is set if we should skip the next reloc, which should be a
732 // PLT32 reloc against ___tls_get_addr.
733 bool skip_call_tls_get_addr_
;
734 // The type of local dynamic relocation we have seen in the section
735 // being relocated, if any.
736 Local_dynamic_type local_dynamic_type_
;
739 // A class for inquiring about properties of a relocation,
740 // used while scanning relocs during a relocatable link and
741 // garbage collection.
742 class Classify_reloc
:
743 public gold::Default_classify_reloc
<elfcpp::SHT_REL
, 32, false>
746 typedef Reloc_types
<elfcpp::SHT_REL
, 32, false>::Reloc Reltype
;
748 // Return the explicit addend of the relocation (return 0 for SHT_REL).
749 static elfcpp::Elf_types
<32>::Elf_Swxword
750 get_r_addend(const Reltype
*)
753 // Return the size of the addend of the relocation (only used for SHT_REL).
755 get_size_for_reloc(unsigned int, Relobj
*);
758 // Adjust TLS relocation type based on the options and whether this
759 // is a local symbol.
760 static tls::Tls_optimization
761 optimize_tls_reloc(bool is_final
, int r_type
);
763 // Check if relocation against this symbol is a candidate for
765 // mov foo@GOT(%reg), %reg
767 // lea foo@GOTOFF(%reg), %reg.
769 can_convert_mov_to_lea(const Symbol
* gsym
)
771 gold_assert(gsym
!= NULL
);
772 return (gsym
->type() != elfcpp::STT_GNU_IFUNC
773 && !gsym
->is_undefined ()
774 && !gsym
->is_from_dynobj()
775 && !gsym
->is_preemptible()
776 && (!parameters
->options().shared()
777 || (gsym
->visibility() != elfcpp::STV_DEFAULT
778 && gsym
->visibility() != elfcpp::STV_PROTECTED
)
779 || parameters
->options().Bsymbolic())
780 && strcmp(gsym
->name(), "_DYNAMIC") != 0);
783 // Get the GOT section, creating it if necessary.
784 Output_data_got
<32, false>*
785 got_section(Symbol_table
*, Layout
*);
787 // Get the GOT PLT section.
788 Output_data_got_plt_i386
*
789 got_plt_section() const
791 gold_assert(this->got_plt_
!= NULL
);
792 return this->got_plt_
;
795 // Get the GOT section for TLSDESC entries.
796 Output_data_got
<32, false>*
797 got_tlsdesc_section() const
799 gold_assert(this->got_tlsdesc_
!= NULL
);
800 return this->got_tlsdesc_
;
803 // Create the PLT section.
805 make_plt_section(Symbol_table
* symtab
, Layout
* layout
);
807 // Create a PLT entry for a global symbol.
809 make_plt_entry(Symbol_table
*, Layout
*, Symbol
*);
811 // Create a PLT entry for a local STT_GNU_IFUNC symbol.
813 make_local_ifunc_plt_entry(Symbol_table
*, Layout
*,
814 Sized_relobj_file
<32, false>* relobj
,
815 unsigned int local_sym_index
);
817 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
819 define_tls_base_symbol(Symbol_table
*, Layout
*);
821 // Create a GOT entry for the TLS module index.
823 got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
824 Sized_relobj_file
<32, false>* object
);
826 // Get the PLT section.
827 Output_data_plt_i386
*
830 gold_assert(this->plt_
!= NULL
);
834 // Get the dynamic reloc section, creating it if necessary.
836 rel_dyn_section(Layout
*);
838 // Get the section to use for TLS_DESC relocations.
840 rel_tls_desc_section(Layout
*) const;
842 // Get the section to use for IRELATIVE relocations.
844 rel_irelative_section(Layout
*);
846 // Add a potential copy relocation.
848 copy_reloc(Symbol_table
* symtab
, Layout
* layout
,
849 Sized_relobj_file
<32, false>* object
,
850 unsigned int shndx
, Output_section
* output_section
,
851 Symbol
* sym
, const elfcpp::Rel
<32, false>& reloc
)
853 unsigned int r_type
= elfcpp::elf_r_type
<32>(reloc
.get_r_info());
854 this->copy_relocs_
.copy_reloc(symtab
, layout
,
855 symtab
->get_sized_symbol
<32>(sym
),
856 object
, shndx
, output_section
,
857 r_type
, reloc
.get_r_offset(), 0,
858 this->rel_dyn_section(layout
));
861 // Information about this specific target which we pass to the
862 // general Target structure.
863 static const Target::Target_info i386_info
;
865 // The types of GOT entries needed for this platform.
866 // These values are exposed to the ABI in an incremental link.
867 // Do not renumber existing values without changing the version
868 // number of the .gnu_incremental_inputs section.
871 GOT_TYPE_STANDARD
= 0, // GOT entry for a regular symbol
872 GOT_TYPE_TLS_NOFFSET
= 1, // GOT entry for negative TLS offset
873 GOT_TYPE_TLS_OFFSET
= 2, // GOT entry for positive TLS offset
874 GOT_TYPE_TLS_PAIR
= 3, // GOT entry for TLS module/offset pair
875 GOT_TYPE_TLS_DESC
= 4 // GOT entry for TLS_DESC pair
879 Output_data_got
<32, false>* got_
;
881 Output_data_plt_i386
* plt_
;
882 // The GOT PLT section.
883 Output_data_got_plt_i386
* got_plt_
;
884 // The GOT section for IRELATIVE relocations.
885 Output_data_space
* got_irelative_
;
886 // The GOT section for TLSDESC relocations.
887 Output_data_got
<32, false>* got_tlsdesc_
;
888 // The _GLOBAL_OFFSET_TABLE_ symbol.
889 Symbol
* global_offset_table_
;
890 // The dynamic reloc section.
891 Reloc_section
* rel_dyn_
;
892 // The section to use for IRELATIVE relocs.
893 Reloc_section
* rel_irelative_
;
894 // Relocs saved to avoid a COPY reloc.
895 Copy_relocs
<elfcpp::SHT_REL
, 32, false> copy_relocs_
;
896 // Offset of the GOT entry for the TLS module index.
897 unsigned int got_mod_index_offset_
;
898 // True if the _TLS_MODULE_BASE_ symbol has been defined.
899 bool tls_base_symbol_defined_
;
902 const Target::Target_info
Target_i386::i386_info
=
905 false, // is_big_endian
906 elfcpp::EM_386
, // machine_code
907 false, // has_make_symbol
908 false, // has_resolve
909 true, // has_code_fill
910 true, // is_default_stack_executable
911 true, // can_icf_inline_merge_sections
913 "/usr/lib/libc.so.1", // dynamic_linker
914 0x08048000, // default_text_segment_address
915 0x1000, // abi_pagesize (overridable by -z max-page-size)
916 0x1000, // common_pagesize (overridable by -z common-page-size)
917 false, // isolate_execinstr
919 elfcpp::SHN_UNDEF
, // small_common_shndx
920 elfcpp::SHN_UNDEF
, // large_common_shndx
921 0, // small_common_section_flags
922 0, // large_common_section_flags
923 NULL
, // attributes_section
924 NULL
, // attributes_vendor
925 "_start", // entry_symbol_name
926 32, // hash_entry_size
929 // Get the GOT section, creating it if necessary.
931 Output_data_got
<32, false>*
932 Target_i386::got_section(Symbol_table
* symtab
, Layout
* layout
)
934 if (this->got_
== NULL
)
936 gold_assert(symtab
!= NULL
&& layout
!= NULL
);
938 this->got_
= new Output_data_got
<32, false>();
940 // When using -z now, we can treat .got.plt as a relro section.
941 // Without -z now, it is modified after program startup by lazy
943 bool is_got_plt_relro
= parameters
->options().now();
944 Output_section_order got_order
= (is_got_plt_relro
947 Output_section_order got_plt_order
= (is_got_plt_relro
949 : ORDER_NON_RELRO_FIRST
);
951 layout
->add_output_section_data(".got", elfcpp::SHT_PROGBITS
,
953 | elfcpp::SHF_WRITE
),
954 this->got_
, got_order
, true);
956 this->got_plt_
= new Output_data_got_plt_i386(layout
);
957 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
959 | elfcpp::SHF_WRITE
),
960 this->got_plt_
, got_plt_order
,
963 // The first three entries are reserved.
964 this->got_plt_
->set_current_data_size(3 * 4);
966 if (!is_got_plt_relro
)
968 // Those bytes can go into the relro segment.
969 layout
->increase_relro(3 * 4);
972 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
973 this->global_offset_table_
=
974 symtab
->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL
,
975 Symbol_table::PREDEFINED
,
977 0, 0, elfcpp::STT_OBJECT
,
979 elfcpp::STV_HIDDEN
, 0,
982 // If there are any IRELATIVE relocations, they get GOT entries
983 // in .got.plt after the jump slot relocations.
984 this->got_irelative_
= new Output_data_space(4, "** GOT IRELATIVE PLT");
985 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
987 | elfcpp::SHF_WRITE
),
988 this->got_irelative_
,
989 got_plt_order
, is_got_plt_relro
);
991 // If there are any TLSDESC relocations, they get GOT entries in
992 // .got.plt after the jump slot entries.
993 this->got_tlsdesc_
= new Output_data_got
<32, false>();
994 layout
->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS
,
996 | elfcpp::SHF_WRITE
),
998 got_plt_order
, is_got_plt_relro
);
1004 // Get the dynamic reloc section, creating it if necessary.
1006 Target_i386::Reloc_section
*
1007 Target_i386::rel_dyn_section(Layout
* layout
)
1009 if (this->rel_dyn_
== NULL
)
1011 gold_assert(layout
!= NULL
);
1012 this->rel_dyn_
= new Reloc_section(parameters
->options().combreloc());
1013 layout
->add_output_section_data(".rel.dyn", elfcpp::SHT_REL
,
1014 elfcpp::SHF_ALLOC
, this->rel_dyn_
,
1015 ORDER_DYNAMIC_RELOCS
, false);
1017 return this->rel_dyn_
;
1020 // Get the section to use for IRELATIVE relocs, creating it if
1021 // necessary. These go in .rel.dyn, but only after all other dynamic
1022 // relocations. They need to follow the other dynamic relocations so
1023 // that they can refer to global variables initialized by those
1026 Target_i386::Reloc_section
*
1027 Target_i386::rel_irelative_section(Layout
* layout
)
1029 if (this->rel_irelative_
== NULL
)
1031 // Make sure we have already create the dynamic reloc section.
1032 this->rel_dyn_section(layout
);
1033 this->rel_irelative_
= new Reloc_section(false);
1034 layout
->add_output_section_data(".rel.dyn", elfcpp::SHT_REL
,
1035 elfcpp::SHF_ALLOC
, this->rel_irelative_
,
1036 ORDER_DYNAMIC_RELOCS
, false);
1037 gold_assert(this->rel_dyn_
->output_section()
1038 == this->rel_irelative_
->output_section());
1040 return this->rel_irelative_
;
1043 // Write the first three reserved words of the .got.plt section.
1044 // The remainder of the section is written while writing the PLT
1045 // in Output_data_plt_i386::do_write.
1048 Output_data_got_plt_i386::do_write(Output_file
* of
)
1050 // The first entry in the GOT is the address of the .dynamic section
1051 // aka the PT_DYNAMIC segment. The next two entries are reserved.
1052 // We saved space for them when we created the section in
1053 // Target_i386::got_section.
1054 const off_t got_file_offset
= this->offset();
1055 gold_assert(this->data_size() >= 12);
1056 unsigned char* const got_view
= of
->get_output_view(got_file_offset
, 12);
1057 Output_section
* dynamic
= this->layout_
->dynamic_section();
1058 uint32_t dynamic_addr
= dynamic
== NULL
? 0 : dynamic
->address();
1059 elfcpp::Swap
<32, false>::writeval(got_view
, dynamic_addr
);
1060 memset(got_view
+ 4, 0, 8);
1061 of
->write_output_view(got_file_offset
, 12, got_view
);
1064 // Create the PLT section. The ordinary .got section is an argument,
1065 // since we need to refer to the start. We also create our own .got
1066 // section just for PLT entries.
1068 Output_data_plt_i386::Output_data_plt_i386(Layout
* layout
,
1070 Output_data_got_plt_i386
* got_plt
,
1071 Output_data_space
* got_irelative
)
1072 : Output_section_data(addralign
),
1073 tls_desc_rel_(NULL
), irelative_rel_(NULL
), got_plt_(got_plt
),
1074 got_irelative_(got_irelative
), count_(0), irelative_count_(0),
1075 global_ifuncs_(), local_ifuncs_()
1077 this->rel_
= new Reloc_section(false);
1078 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
1079 elfcpp::SHF_ALLOC
, this->rel_
,
1080 ORDER_DYNAMIC_PLT_RELOCS
, false);
1084 Output_data_plt_i386::do_adjust_output_section(Output_section
* os
)
1086 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
1087 // linker, and so do we.
1091 // Add an entry to the PLT.
1094 Output_data_plt_i386::add_entry(Symbol_table
* symtab
, Layout
* layout
,
1097 gold_assert(!gsym
->has_plt_offset());
1099 // Every PLT entry needs a reloc.
1100 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1101 && gsym
->can_use_relative_reloc(false))
1103 gsym
->set_plt_offset(this->irelative_count_
* this->get_plt_entry_size());
1104 ++this->irelative_count_
;
1105 section_offset_type got_offset
=
1106 this->got_irelative_
->current_data_size();
1107 this->got_irelative_
->set_current_data_size(got_offset
+ 4);
1108 Reloc_section
* rel
= this->rel_irelative(symtab
, layout
);
1109 rel
->add_symbolless_global_addend(gsym
, elfcpp::R_386_IRELATIVE
,
1110 this->got_irelative_
, got_offset
);
1111 struct Global_ifunc gi
;
1113 gi
.got_offset
= got_offset
;
1114 this->global_ifuncs_
.push_back(gi
);
1118 // When setting the PLT offset we skip the initial reserved PLT
1120 gsym
->set_plt_offset((this->count_
+ 1) * this->get_plt_entry_size());
1124 section_offset_type got_offset
= this->got_plt_
->current_data_size();
1126 // Every PLT entry needs a GOT entry which points back to the
1127 // PLT entry (this will be changed by the dynamic linker,
1128 // normally lazily when the function is called).
1129 this->got_plt_
->set_current_data_size(got_offset
+ 4);
1131 gsym
->set_needs_dynsym_entry();
1132 this->rel_
->add_global(gsym
, elfcpp::R_386_JUMP_SLOT
, this->got_plt_
,
1136 // Note that we don't need to save the symbol. The contents of the
1137 // PLT are independent of which symbols are used. The symbols only
1138 // appear in the relocations.
1141 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
1145 Output_data_plt_i386::add_local_ifunc_entry(
1146 Symbol_table
* symtab
,
1148 Sized_relobj_file
<32, false>* relobj
,
1149 unsigned int local_sym_index
)
1151 unsigned int plt_offset
= this->irelative_count_
* this->get_plt_entry_size();
1152 ++this->irelative_count_
;
1154 section_offset_type got_offset
= this->got_irelative_
->current_data_size();
1156 // Every PLT entry needs a GOT entry which points back to the PLT
1158 this->got_irelative_
->set_current_data_size(got_offset
+ 4);
1160 // Every PLT entry needs a reloc.
1161 Reloc_section
* rel
= this->rel_irelative(symtab
, layout
);
1162 rel
->add_symbolless_local_addend(relobj
, local_sym_index
,
1163 elfcpp::R_386_IRELATIVE
,
1164 this->got_irelative_
, got_offset
);
1166 struct Local_ifunc li
;
1168 li
.local_sym_index
= local_sym_index
;
1169 li
.got_offset
= got_offset
;
1170 this->local_ifuncs_
.push_back(li
);
1175 // Return where the TLS_DESC relocations should go, creating it if
1176 // necessary. These follow the JUMP_SLOT relocations.
1178 Output_data_plt_i386::Reloc_section
*
1179 Output_data_plt_i386::rel_tls_desc(Layout
* layout
)
1181 if (this->tls_desc_rel_
== NULL
)
1183 this->tls_desc_rel_
= new Reloc_section(false);
1184 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
1185 elfcpp::SHF_ALLOC
, this->tls_desc_rel_
,
1186 ORDER_DYNAMIC_PLT_RELOCS
, false);
1187 gold_assert(this->tls_desc_rel_
->output_section()
1188 == this->rel_
->output_section());
1190 return this->tls_desc_rel_
;
1193 // Return where the IRELATIVE relocations should go in the PLT. These
1194 // follow the JUMP_SLOT and TLS_DESC relocations.
1196 Output_data_plt_i386::Reloc_section
*
1197 Output_data_plt_i386::rel_irelative(Symbol_table
* symtab
, Layout
* layout
)
1199 if (this->irelative_rel_
== NULL
)
1201 // Make sure we have a place for the TLS_DESC relocations, in
1202 // case we see any later on.
1203 this->rel_tls_desc(layout
);
1204 this->irelative_rel_
= new Reloc_section(false);
1205 layout
->add_output_section_data(".rel.plt", elfcpp::SHT_REL
,
1206 elfcpp::SHF_ALLOC
, this->irelative_rel_
,
1207 ORDER_DYNAMIC_PLT_RELOCS
, false);
1208 gold_assert(this->irelative_rel_
->output_section()
1209 == this->rel_
->output_section());
1211 if (parameters
->doing_static_link())
1213 // A statically linked executable will only have a .rel.plt
1214 // section to hold R_386_IRELATIVE relocs for STT_GNU_IFUNC
1215 // symbols. The library will use these symbols to locate
1216 // the IRELATIVE relocs at program startup time.
1217 symtab
->define_in_output_data("__rel_iplt_start", NULL
,
1218 Symbol_table::PREDEFINED
,
1219 this->irelative_rel_
, 0, 0,
1220 elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
1221 elfcpp::STV_HIDDEN
, 0, false, true);
1222 symtab
->define_in_output_data("__rel_iplt_end", NULL
,
1223 Symbol_table::PREDEFINED
,
1224 this->irelative_rel_
, 0, 0,
1225 elfcpp::STT_NOTYPE
, elfcpp::STB_GLOBAL
,
1226 elfcpp::STV_HIDDEN
, 0, true, true);
1229 return this->irelative_rel_
;
1232 // Return the PLT address to use for a global symbol.
1235 Output_data_plt_i386::address_for_global(const Symbol
* gsym
)
1237 uint64_t offset
= 0;
1238 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
1239 && gsym
->can_use_relative_reloc(false))
1240 offset
= (this->count_
+ 1) * this->get_plt_entry_size();
1241 return this->address() + offset
+ gsym
->plt_offset();
1244 // Return the PLT address to use for a local symbol. These are always
1245 // IRELATIVE relocs.
1248 Output_data_plt_i386::address_for_local(const Relobj
* object
,
1251 return (this->address()
1252 + (this->count_
+ 1) * this->get_plt_entry_size()
1253 + object
->local_plt_offset(r_sym
));
1256 // The first entry in the PLT for an executable.
1258 const unsigned char Output_data_plt_i386_exec::first_plt_entry
[plt_entry_size
] =
1260 0xff, 0x35, // pushl contents of memory address
1261 0, 0, 0, 0, // replaced with address of .got + 4
1262 0xff, 0x25, // jmp indirect
1263 0, 0, 0, 0, // replaced with address of .got + 8
1264 0, 0, 0, 0 // unused
1268 Output_data_plt_i386_exec::do_fill_first_plt_entry(
1270 elfcpp::Elf_types
<32>::Elf_Addr got_address
)
1272 memcpy(pov
, first_plt_entry
, plt_entry_size
);
1273 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 4);
1274 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 8);
1277 // The first entry in the PLT for a shared object.
1279 const unsigned char Output_data_plt_i386_dyn::first_plt_entry
[plt_entry_size
] =
1281 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
1282 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
1283 0, 0, 0, 0 // unused
1287 Output_data_plt_i386_dyn::do_fill_first_plt_entry(
1289 elfcpp::Elf_types
<32>::Elf_Addr
)
1291 memcpy(pov
, first_plt_entry
, plt_entry_size
);
1294 // Subsequent entries in the PLT for an executable.
1296 const unsigned char Output_data_plt_i386_exec::plt_entry
[plt_entry_size
] =
1298 0xff, 0x25, // jmp indirect
1299 0, 0, 0, 0, // replaced with address of symbol in .got
1300 0x68, // pushl immediate
1301 0, 0, 0, 0, // replaced with offset into relocation table
1302 0xe9, // jmp relative
1303 0, 0, 0, 0 // replaced with offset to start of .plt
1307 Output_data_plt_i386_exec::do_fill_plt_entry(
1309 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
1310 unsigned int got_offset
,
1311 unsigned int plt_offset
,
1312 unsigned int plt_rel_offset
)
1314 memcpy(pov
, plt_entry
, plt_entry_size
);
1315 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
1316 got_address
+ got_offset
);
1317 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_rel_offset
);
1318 elfcpp::Swap
<32, false>::writeval(pov
+ 12, - (plt_offset
+ 12 + 4));
1322 // Subsequent entries in the PLT for a shared object.
1324 const unsigned char Output_data_plt_i386_dyn::plt_entry
[plt_entry_size
] =
1326 0xff, 0xa3, // jmp *offset(%ebx)
1327 0, 0, 0, 0, // replaced with offset of symbol in .got
1328 0x68, // pushl immediate
1329 0, 0, 0, 0, // replaced with offset into relocation table
1330 0xe9, // jmp relative
1331 0, 0, 0, 0 // replaced with offset to start of .plt
1335 Output_data_plt_i386_dyn::do_fill_plt_entry(unsigned char* pov
,
1336 elfcpp::Elf_types
<32>::Elf_Addr
,
1337 unsigned int got_offset
,
1338 unsigned int plt_offset
,
1339 unsigned int plt_rel_offset
)
1341 memcpy(pov
, plt_entry
, plt_entry_size
);
1342 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
1343 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 7, plt_rel_offset
);
1344 elfcpp::Swap
<32, false>::writeval(pov
+ 12, - (plt_offset
+ 12 + 4));
1348 // The .eh_frame unwind information for the PLT.
1351 Output_data_plt_i386::plt_eh_frame_cie
[plt_eh_frame_cie_size
] =
1354 'z', // Augmentation: augmentation size included.
1355 'R', // Augmentation: FDE encoding included.
1356 '\0', // End of augmentation string.
1357 1, // Code alignment factor.
1358 0x7c, // Data alignment factor.
1359 8, // Return address column.
1360 1, // Augmentation size.
1361 (elfcpp::DW_EH_PE_pcrel
// FDE encoding.
1362 | elfcpp::DW_EH_PE_sdata4
),
1363 elfcpp::DW_CFA_def_cfa
, 4, 4, // DW_CFA_def_cfa: r4 (esp) ofs 4.
1364 elfcpp::DW_CFA_offset
+ 8, 1, // DW_CFA_offset: r8 (eip) at cfa-4.
1365 elfcpp::DW_CFA_nop
, // Align to 16 bytes.
1370 Output_data_plt_i386_standard::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
1372 0, 0, 0, 0, // Replaced with offset to .plt.
1373 0, 0, 0, 0, // Replaced with size of .plt.
1374 0, // Augmentation size.
1375 elfcpp::DW_CFA_def_cfa_offset
, 8, // DW_CFA_def_cfa_offset: 8.
1376 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
1377 elfcpp::DW_CFA_def_cfa_offset
, 12, // DW_CFA_def_cfa_offset: 12.
1378 elfcpp::DW_CFA_advance_loc
+ 10, // Advance 10 to __PLT__ + 16.
1379 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
1380 11, // Block length.
1381 elfcpp::DW_OP_breg4
, 4, // Push %esp + 4.
1382 elfcpp::DW_OP_breg8
, 0, // Push %eip.
1383 elfcpp::DW_OP_lit15
, // Push 0xf.
1384 elfcpp::DW_OP_and
, // & (%eip & 0xf).
1385 elfcpp::DW_OP_lit11
, // Push 0xb.
1386 elfcpp::DW_OP_ge
, // >= ((%eip & 0xf) >= 0xb)
1387 elfcpp::DW_OP_lit2
, // Push 2.
1388 elfcpp::DW_OP_shl
, // << (((%eip & 0xf) >= 0xb) << 2)
1389 elfcpp::DW_OP_plus
, // + ((((%eip&0xf)>=0xb)<<2)+%esp+4
1390 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
1396 // Write out the PLT. This uses the hand-coded instructions above,
1397 // and adjusts them as needed. This is all specified by the i386 ELF
1398 // Processor Supplement.
1401 Output_data_plt_i386::do_write(Output_file
* of
)
1403 const off_t offset
= this->offset();
1404 const section_size_type oview_size
=
1405 convert_to_section_size_type(this->data_size());
1406 unsigned char* const oview
= of
->get_output_view(offset
, oview_size
);
1408 const off_t got_file_offset
= this->got_plt_
->offset();
1409 gold_assert(parameters
->incremental_update()
1410 || (got_file_offset
+ this->got_plt_
->data_size()
1411 == this->got_irelative_
->offset()));
1412 const section_size_type got_size
=
1413 convert_to_section_size_type(this->got_plt_
->data_size()
1414 + this->got_irelative_
->data_size());
1416 unsigned char* const got_view
= of
->get_output_view(got_file_offset
,
1419 unsigned char* pov
= oview
;
1421 elfcpp::Elf_types
<32>::Elf_Addr plt_address
= this->address();
1422 elfcpp::Elf_types
<32>::Elf_Addr got_address
= this->got_plt_
->address();
1424 this->fill_first_plt_entry(pov
, got_address
);
1425 pov
+= this->get_plt_entry_size();
1427 // The first three entries in the GOT are reserved, and are written
1428 // by Output_data_got_plt_i386::do_write.
1429 unsigned char* got_pov
= got_view
+ 12;
1431 const int rel_size
= elfcpp::Elf_sizes
<32>::rel_size
;
1433 unsigned int plt_offset
= this->get_plt_entry_size();
1434 unsigned int plt_rel_offset
= 0;
1435 unsigned int got_offset
= 12;
1436 const unsigned int count
= this->count_
+ this->irelative_count_
;
1437 for (unsigned int i
= 0;
1440 pov
+= this->get_plt_entry_size(),
1442 plt_offset
+= this->get_plt_entry_size(),
1443 plt_rel_offset
+= rel_size
,
1446 // Set and adjust the PLT entry itself.
1447 unsigned int lazy_offset
= this->fill_plt_entry(pov
,
1453 // Set the entry in the GOT.
1454 elfcpp::Swap
<32, false>::writeval(got_pov
,
1455 plt_address
+ plt_offset
+ lazy_offset
);
1458 // If any STT_GNU_IFUNC symbols have PLT entries, we need to change
1459 // the GOT to point to the actual symbol value, rather than point to
1460 // the PLT entry. That will let the dynamic linker call the right
1461 // function when resolving IRELATIVE relocations.
1462 unsigned char* got_irelative_view
= got_view
+ this->got_plt_
->data_size();
1463 for (std::vector
<Global_ifunc
>::const_iterator p
=
1464 this->global_ifuncs_
.begin();
1465 p
!= this->global_ifuncs_
.end();
1468 const Sized_symbol
<32>* ssym
=
1469 static_cast<const Sized_symbol
<32>*>(p
->sym
);
1470 elfcpp::Swap
<32, false>::writeval(got_irelative_view
+ p
->got_offset
,
1474 for (std::vector
<Local_ifunc
>::const_iterator p
=
1475 this->local_ifuncs_
.begin();
1476 p
!= this->local_ifuncs_
.end();
1479 const Symbol_value
<32>* psymval
=
1480 p
->object
->local_symbol(p
->local_sym_index
);
1481 elfcpp::Swap
<32, false>::writeval(got_irelative_view
+ p
->got_offset
,
1482 psymval
->value(p
->object
, 0));
1485 gold_assert(static_cast<section_size_type
>(pov
- oview
) == oview_size
);
1486 gold_assert(static_cast<section_size_type
>(got_pov
- got_view
) == got_size
);
1488 of
->write_output_view(offset
, oview_size
, oview
);
1489 of
->write_output_view(got_file_offset
, got_size
, got_view
);
1492 // Create the PLT section.
1495 Target_i386::make_plt_section(Symbol_table
* symtab
, Layout
* layout
)
1497 if (this->plt_
== NULL
)
1499 // Create the GOT sections first.
1500 this->got_section(symtab
, layout
);
1502 const bool dyn
= parameters
->options().output_is_position_independent();
1503 this->plt_
= this->make_data_plt(layout
,
1505 this->got_irelative_
,
1508 // Add unwind information if requested.
1509 if (parameters
->options().ld_generated_unwind_info())
1510 this->plt_
->add_eh_frame(layout
);
1512 layout
->add_output_section_data(".plt", elfcpp::SHT_PROGBITS
,
1514 | elfcpp::SHF_EXECINSTR
),
1515 this->plt_
, ORDER_PLT
, false);
1517 // Make the sh_info field of .rel.plt point to .plt.
1518 Output_section
* rel_plt_os
= this->plt_
->rel_plt()->output_section();
1519 rel_plt_os
->set_info_section(this->plt_
->output_section());
1523 // Create a PLT entry for a global symbol.
1526 Target_i386::make_plt_entry(Symbol_table
* symtab
, Layout
* layout
, Symbol
* gsym
)
1528 if (gsym
->has_plt_offset())
1530 if (this->plt_
== NULL
)
1531 this->make_plt_section(symtab
, layout
);
1532 this->plt_
->add_entry(symtab
, layout
, gsym
);
1535 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
1538 Target_i386::make_local_ifunc_plt_entry(Symbol_table
* symtab
, Layout
* layout
,
1539 Sized_relobj_file
<32, false>* relobj
,
1540 unsigned int local_sym_index
)
1542 if (relobj
->local_has_plt_offset(local_sym_index
))
1544 if (this->plt_
== NULL
)
1545 this->make_plt_section(symtab
, layout
);
1546 unsigned int plt_offset
= this->plt_
->add_local_ifunc_entry(symtab
, layout
,
1549 relobj
->set_local_plt_offset(local_sym_index
, plt_offset
);
1552 // Return the number of entries in the PLT.
1555 Target_i386::plt_entry_count() const
1557 if (this->plt_
== NULL
)
1559 return this->plt_
->entry_count();
1562 // Return the offset of the first non-reserved PLT entry.
1565 Target_i386::first_plt_entry_offset() const
1567 return this->plt_
->first_plt_entry_offset();
1570 // Return the size of each PLT entry.
1573 Target_i386::plt_entry_size() const
1575 return this->plt_
->get_plt_entry_size();
1578 // Get the section to use for TLS_DESC relocations.
1580 Target_i386::Reloc_section
*
1581 Target_i386::rel_tls_desc_section(Layout
* layout
) const
1583 return this->plt_section()->rel_tls_desc(layout
);
1586 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1589 Target_i386::define_tls_base_symbol(Symbol_table
* symtab
, Layout
* layout
)
1591 if (this->tls_base_symbol_defined_
)
1594 Output_segment
* tls_segment
= layout
->tls_segment();
1595 if (tls_segment
!= NULL
)
1597 bool is_exec
= parameters
->options().output_is_executable();
1598 symtab
->define_in_output_segment("_TLS_MODULE_BASE_", NULL
,
1599 Symbol_table::PREDEFINED
,
1603 elfcpp::STV_HIDDEN
, 0,
1605 ? Symbol::SEGMENT_END
1606 : Symbol::SEGMENT_START
),
1609 this->tls_base_symbol_defined_
= true;
1612 // Create a GOT entry for the TLS module index.
1615 Target_i386::got_mod_index_entry(Symbol_table
* symtab
, Layout
* layout
,
1616 Sized_relobj_file
<32, false>* object
)
1618 if (this->got_mod_index_offset_
== -1U)
1620 gold_assert(symtab
!= NULL
&& layout
!= NULL
&& object
!= NULL
);
1621 Reloc_section
* rel_dyn
= this->rel_dyn_section(layout
);
1622 Output_data_got
<32, false>* got
= this->got_section(symtab
, layout
);
1623 unsigned int got_offset
= got
->add_constant(0);
1624 rel_dyn
->add_local(object
, 0, elfcpp::R_386_TLS_DTPMOD32
, got
,
1626 got
->add_constant(0);
1627 this->got_mod_index_offset_
= got_offset
;
1629 return this->got_mod_index_offset_
;
1632 // Optimize the TLS relocation type based on what we know about the
1633 // symbol. IS_FINAL is true if the final address of this symbol is
1634 // known at link time.
1636 tls::Tls_optimization
1637 Target_i386::optimize_tls_reloc(bool is_final
, int r_type
)
1639 // If we are generating a shared library, then we can't do anything
1641 if (parameters
->options().shared())
1642 return tls::TLSOPT_NONE
;
1646 case elfcpp::R_386_TLS_GD
:
1647 case elfcpp::R_386_TLS_GOTDESC
:
1648 case elfcpp::R_386_TLS_DESC_CALL
:
1649 // These are General-Dynamic which permits fully general TLS
1650 // access. Since we know that we are generating an executable,
1651 // we can convert this to Initial-Exec. If we also know that
1652 // this is a local symbol, we can further switch to Local-Exec.
1654 return tls::TLSOPT_TO_LE
;
1655 return tls::TLSOPT_TO_IE
;
1657 case elfcpp::R_386_TLS_LDM
:
1658 // This is Local-Dynamic, which refers to a local symbol in the
1659 // dynamic TLS block. Since we know that we generating an
1660 // executable, we can switch to Local-Exec.
1661 return tls::TLSOPT_TO_LE
;
1663 case elfcpp::R_386_TLS_LDO_32
:
1664 // Another type of Local-Dynamic relocation.
1665 return tls::TLSOPT_TO_LE
;
1667 case elfcpp::R_386_TLS_IE
:
1668 case elfcpp::R_386_TLS_GOTIE
:
1669 case elfcpp::R_386_TLS_IE_32
:
1670 // These are Initial-Exec relocs which get the thread offset
1671 // from the GOT. If we know that we are linking against the
1672 // local symbol, we can switch to Local-Exec, which links the
1673 // thread offset into the instruction.
1675 return tls::TLSOPT_TO_LE
;
1676 return tls::TLSOPT_NONE
;
1678 case elfcpp::R_386_TLS_LE
:
1679 case elfcpp::R_386_TLS_LE_32
:
1680 // When we already have Local-Exec, there is nothing further we
1682 return tls::TLSOPT_NONE
;
1689 // Get the Reference_flags for a particular relocation.
1692 Target_i386::Scan::get_reference_flags(unsigned int r_type
)
1696 case elfcpp::R_386_NONE
:
1697 case elfcpp::R_386_GNU_VTINHERIT
:
1698 case elfcpp::R_386_GNU_VTENTRY
:
1699 case elfcpp::R_386_GOTPC
:
1700 // No symbol reference.
1703 case elfcpp::R_386_32
:
1704 case elfcpp::R_386_16
:
1705 case elfcpp::R_386_8
:
1706 return Symbol::ABSOLUTE_REF
;
1708 case elfcpp::R_386_PC32
:
1709 case elfcpp::R_386_PC16
:
1710 case elfcpp::R_386_PC8
:
1711 case elfcpp::R_386_GOTOFF
:
1712 return Symbol::RELATIVE_REF
;
1714 case elfcpp::R_386_PLT32
:
1715 return Symbol::FUNCTION_CALL
| Symbol::RELATIVE_REF
;
1717 case elfcpp::R_386_GOT32
:
1718 case elfcpp::R_386_GOT32X
:
1720 return Symbol::ABSOLUTE_REF
;
1722 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1723 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1724 case elfcpp::R_386_TLS_DESC_CALL
:
1725 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1726 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1727 case elfcpp::R_386_TLS_IE
: // Initial-exec
1728 case elfcpp::R_386_TLS_IE_32
:
1729 case elfcpp::R_386_TLS_GOTIE
:
1730 case elfcpp::R_386_TLS_LE
: // Local-exec
1731 case elfcpp::R_386_TLS_LE_32
:
1732 return Symbol::TLS_REF
;
1734 case elfcpp::R_386_COPY
:
1735 case elfcpp::R_386_GLOB_DAT
:
1736 case elfcpp::R_386_JUMP_SLOT
:
1737 case elfcpp::R_386_RELATIVE
:
1738 case elfcpp::R_386_IRELATIVE
:
1739 case elfcpp::R_386_TLS_TPOFF
:
1740 case elfcpp::R_386_TLS_DTPMOD32
:
1741 case elfcpp::R_386_TLS_DTPOFF32
:
1742 case elfcpp::R_386_TLS_TPOFF32
:
1743 case elfcpp::R_386_TLS_DESC
:
1744 case elfcpp::R_386_32PLT
:
1745 case elfcpp::R_386_TLS_GD_32
:
1746 case elfcpp::R_386_TLS_GD_PUSH
:
1747 case elfcpp::R_386_TLS_GD_CALL
:
1748 case elfcpp::R_386_TLS_GD_POP
:
1749 case elfcpp::R_386_TLS_LDM_32
:
1750 case elfcpp::R_386_TLS_LDM_PUSH
:
1751 case elfcpp::R_386_TLS_LDM_CALL
:
1752 case elfcpp::R_386_TLS_LDM_POP
:
1753 case elfcpp::R_386_USED_BY_INTEL_200
:
1755 // Not expected. We will give an error later.
1760 // Report an unsupported relocation against a local symbol.
1763 Target_i386::Scan::unsupported_reloc_local(Sized_relobj_file
<32, false>* object
,
1764 unsigned int r_type
)
1766 gold_error(_("%s: unsupported reloc %u against local symbol"),
1767 object
->name().c_str(), r_type
);
1770 // Return whether we need to make a PLT entry for a relocation of a
1771 // given type against a STT_GNU_IFUNC symbol.
1774 Target_i386::Scan::reloc_needs_plt_for_ifunc(
1775 Sized_relobj_file
<32, false>* object
,
1776 unsigned int r_type
)
1778 int flags
= Scan::get_reference_flags(r_type
);
1779 if (flags
& Symbol::TLS_REF
)
1780 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
1781 object
->name().c_str(), r_type
);
1785 // Scan a relocation for a local symbol.
1788 Target_i386::Scan::local(Symbol_table
* symtab
,
1790 Target_i386
* target
,
1791 Sized_relobj_file
<32, false>* object
,
1792 unsigned int data_shndx
,
1793 Output_section
* output_section
,
1794 const elfcpp::Rel
<32, false>& reloc
,
1795 unsigned int r_type
,
1796 const elfcpp::Sym
<32, false>& lsym
,
1802 // A local STT_GNU_IFUNC symbol may require a PLT entry.
1803 if (lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
1804 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
1806 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1807 target
->make_local_ifunc_plt_entry(symtab
, layout
, object
, r_sym
);
1812 case elfcpp::R_386_NONE
:
1813 case elfcpp::R_386_GNU_VTINHERIT
:
1814 case elfcpp::R_386_GNU_VTENTRY
:
1817 case elfcpp::R_386_32
:
1818 // If building a shared library (or a position-independent
1819 // executable), we need to create a dynamic relocation for
1820 // this location. The relocation applied at link time will
1821 // apply the link-time value, so we flag the location with
1822 // an R_386_RELATIVE relocation so the dynamic loader can
1823 // relocate it easily.
1824 if (parameters
->options().output_is_position_independent())
1826 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1827 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1828 rel_dyn
->add_local_relative(object
, r_sym
, elfcpp::R_386_RELATIVE
,
1829 output_section
, data_shndx
,
1830 reloc
.get_r_offset());
1834 case elfcpp::R_386_16
:
1835 case elfcpp::R_386_8
:
1836 // If building a shared library (or a position-independent
1837 // executable), we need to create a dynamic relocation for
1838 // this location. Because the addend needs to remain in the
1839 // data section, we need to be careful not to apply this
1840 // relocation statically.
1841 if (parameters
->options().output_is_position_independent())
1843 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1844 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1845 if (lsym
.get_st_type() != elfcpp::STT_SECTION
)
1846 rel_dyn
->add_local(object
, r_sym
, r_type
, output_section
,
1847 data_shndx
, reloc
.get_r_offset());
1850 gold_assert(lsym
.get_st_value() == 0);
1851 unsigned int shndx
= lsym
.get_st_shndx();
1853 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
,
1856 object
->error(_("section symbol %u has bad shndx %u"),
1859 rel_dyn
->add_local_section(object
, shndx
,
1860 r_type
, output_section
,
1861 data_shndx
, reloc
.get_r_offset());
1866 case elfcpp::R_386_PC32
:
1867 case elfcpp::R_386_PC16
:
1868 case elfcpp::R_386_PC8
:
1871 case elfcpp::R_386_PLT32
:
1872 // Since we know this is a local symbol, we can handle this as a
1876 case elfcpp::R_386_GOTOFF
:
1877 case elfcpp::R_386_GOTPC
:
1878 // We need a GOT section.
1879 target
->got_section(symtab
, layout
);
1882 case elfcpp::R_386_GOT32
:
1883 case elfcpp::R_386_GOT32X
:
1885 // We need GOT section.
1886 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
1888 // If the relocation symbol isn't IFUNC,
1889 // and is local, then we will convert
1890 // mov foo@GOT(%reg), %reg
1892 // lea foo@GOTOFF(%reg), %reg
1893 // in Relocate::relocate.
1894 if (reloc
.get_r_offset() >= 2
1895 && lsym
.get_st_type() != elfcpp::STT_GNU_IFUNC
)
1897 section_size_type stype
;
1898 const unsigned char* view
= object
->section_contents(data_shndx
,
1900 if (view
[reloc
.get_r_offset() - 2] == 0x8b)
1904 // Otherwise, the symbol requires a GOT entry.
1905 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1907 // For a STT_GNU_IFUNC symbol we want the PLT offset. That
1908 // lets function pointers compare correctly with shared
1909 // libraries. Otherwise we would need an IRELATIVE reloc.
1911 if (lsym
.get_st_type() == elfcpp::STT_GNU_IFUNC
)
1912 is_new
= got
->add_local_plt(object
, r_sym
, GOT_TYPE_STANDARD
);
1914 is_new
= got
->add_local(object
, r_sym
, GOT_TYPE_STANDARD
);
1917 // If we are generating a shared object, we need to add a
1918 // dynamic RELATIVE relocation for this symbol's GOT entry.
1919 if (parameters
->options().output_is_position_independent())
1921 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
1922 unsigned int got_offset
=
1923 object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
);
1924 rel_dyn
->add_local_relative(object
, r_sym
,
1925 elfcpp::R_386_RELATIVE
,
1932 // These are relocations which should only be seen by the
1933 // dynamic linker, and should never be seen here.
1934 case elfcpp::R_386_COPY
:
1935 case elfcpp::R_386_GLOB_DAT
:
1936 case elfcpp::R_386_JUMP_SLOT
:
1937 case elfcpp::R_386_RELATIVE
:
1938 case elfcpp::R_386_IRELATIVE
:
1939 case elfcpp::R_386_TLS_TPOFF
:
1940 case elfcpp::R_386_TLS_DTPMOD32
:
1941 case elfcpp::R_386_TLS_DTPOFF32
:
1942 case elfcpp::R_386_TLS_TPOFF32
:
1943 case elfcpp::R_386_TLS_DESC
:
1944 gold_error(_("%s: unexpected reloc %u in object file"),
1945 object
->name().c_str(), r_type
);
1948 // These are initial TLS relocs, which are expected when
1950 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1951 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
1952 case elfcpp::R_386_TLS_DESC_CALL
:
1953 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
1954 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
1955 case elfcpp::R_386_TLS_IE
: // Initial-exec
1956 case elfcpp::R_386_TLS_IE_32
:
1957 case elfcpp::R_386_TLS_GOTIE
:
1958 case elfcpp::R_386_TLS_LE
: // Local-exec
1959 case elfcpp::R_386_TLS_LE_32
:
1961 bool output_is_shared
= parameters
->options().shared();
1962 const tls::Tls_optimization optimized_type
1963 = Target_i386::optimize_tls_reloc(!output_is_shared
, r_type
);
1966 case elfcpp::R_386_TLS_GD
: // Global-dynamic
1967 if (optimized_type
== tls::TLSOPT_NONE
)
1969 // Create a pair of GOT entries for the module index and
1970 // dtv-relative offset.
1971 Output_data_got
<32, false>* got
1972 = target
->got_section(symtab
, layout
);
1973 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
1974 unsigned int shndx
= lsym
.get_st_shndx();
1976 shndx
= object
->adjust_sym_shndx(r_sym
, shndx
, &is_ordinary
);
1978 object
->error(_("local symbol %u has bad shndx %u"),
1981 got
->add_local_pair_with_rel(object
, r_sym
, shndx
,
1983 target
->rel_dyn_section(layout
),
1984 elfcpp::R_386_TLS_DTPMOD32
);
1986 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
1987 unsupported_reloc_local(object
, r_type
);
1990 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva)
1991 target
->define_tls_base_symbol(symtab
, layout
);
1992 if (optimized_type
== tls::TLSOPT_NONE
)
1994 // Create a double GOT entry with an R_386_TLS_DESC
1995 // reloc. The R_386_TLS_DESC reloc is resolved
1996 // lazily, so the GOT entry needs to be in an area in
1997 // .got.plt, not .got. Call got_section to make sure
1998 // the section has been created.
1999 target
->got_section(symtab
, layout
);
2000 Output_data_got
<32, false>* got
= target
->got_tlsdesc_section();
2001 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
2002 if (!object
->local_has_got_offset(r_sym
, GOT_TYPE_TLS_DESC
))
2004 unsigned int got_offset
= got
->add_constant(0);
2005 // The local symbol value is stored in the second
2007 got
->add_local(object
, r_sym
, GOT_TYPE_TLS_DESC
);
2008 // That set the GOT offset of the local symbol to
2009 // point to the second entry, but we want it to
2010 // point to the first.
2011 object
->set_local_got_offset(r_sym
, GOT_TYPE_TLS_DESC
,
2013 Reloc_section
* rt
= target
->rel_tls_desc_section(layout
);
2014 rt
->add_absolute(elfcpp::R_386_TLS_DESC
, got
, got_offset
);
2017 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2018 unsupported_reloc_local(object
, r_type
);
2021 case elfcpp::R_386_TLS_DESC_CALL
:
2024 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2025 if (optimized_type
== tls::TLSOPT_NONE
)
2027 // Create a GOT entry for the module index.
2028 target
->got_mod_index_entry(symtab
, layout
, object
);
2030 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2031 unsupported_reloc_local(object
, r_type
);
2034 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2037 case elfcpp::R_386_TLS_IE
: // Initial-exec
2038 case elfcpp::R_386_TLS_IE_32
:
2039 case elfcpp::R_386_TLS_GOTIE
:
2040 layout
->set_has_static_tls();
2041 if (optimized_type
== tls::TLSOPT_NONE
)
2043 // For the R_386_TLS_IE relocation, we need to create a
2044 // dynamic relocation when building a shared library.
2045 if (r_type
== elfcpp::R_386_TLS_IE
2046 && parameters
->options().shared())
2048 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2050 = elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
2051 rel_dyn
->add_local_relative(object
, r_sym
,
2052 elfcpp::R_386_RELATIVE
,
2053 output_section
, data_shndx
,
2054 reloc
.get_r_offset());
2056 // Create a GOT entry for the tp-relative offset.
2057 Output_data_got
<32, false>* got
2058 = target
->got_section(symtab
, layout
);
2059 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
2060 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2061 ? elfcpp::R_386_TLS_TPOFF32
2062 : elfcpp::R_386_TLS_TPOFF
);
2063 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2064 ? GOT_TYPE_TLS_OFFSET
2065 : GOT_TYPE_TLS_NOFFSET
);
2066 got
->add_local_with_rel(object
, r_sym
, got_type
,
2067 target
->rel_dyn_section(layout
),
2070 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2071 unsupported_reloc_local(object
, r_type
);
2074 case elfcpp::R_386_TLS_LE
: // Local-exec
2075 case elfcpp::R_386_TLS_LE_32
:
2076 layout
->set_has_static_tls();
2077 if (output_is_shared
)
2079 // We need to create a dynamic relocation.
2080 gold_assert(lsym
.get_st_type() != elfcpp::STT_SECTION
);
2081 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(reloc
.get_r_info());
2082 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
2083 ? elfcpp::R_386_TLS_TPOFF32
2084 : elfcpp::R_386_TLS_TPOFF
);
2085 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2086 rel_dyn
->add_local(object
, r_sym
, dyn_r_type
, output_section
,
2087 data_shndx
, reloc
.get_r_offset());
2097 case elfcpp::R_386_32PLT
:
2098 case elfcpp::R_386_TLS_GD_32
:
2099 case elfcpp::R_386_TLS_GD_PUSH
:
2100 case elfcpp::R_386_TLS_GD_CALL
:
2101 case elfcpp::R_386_TLS_GD_POP
:
2102 case elfcpp::R_386_TLS_LDM_32
:
2103 case elfcpp::R_386_TLS_LDM_PUSH
:
2104 case elfcpp::R_386_TLS_LDM_CALL
:
2105 case elfcpp::R_386_TLS_LDM_POP
:
2106 case elfcpp::R_386_USED_BY_INTEL_200
:
2108 unsupported_reloc_local(object
, r_type
);
2113 // Report an unsupported relocation against a global symbol.
2116 Target_i386::Scan::unsupported_reloc_global(
2117 Sized_relobj_file
<32, false>* object
,
2118 unsigned int r_type
,
2121 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
2122 object
->name().c_str(), r_type
, gsym
->demangled_name().c_str());
2126 Target_i386::Scan::possible_function_pointer_reloc(unsigned int r_type
)
2130 case elfcpp::R_386_32
:
2131 case elfcpp::R_386_16
:
2132 case elfcpp::R_386_8
:
2133 case elfcpp::R_386_GOTOFF
:
2134 case elfcpp::R_386_GOT32
:
2135 case elfcpp::R_386_GOT32X
:
2146 Target_i386::Scan::local_reloc_may_be_function_pointer(
2150 Sized_relobj_file
<32, false>* ,
2153 const elfcpp::Rel
<32, false>& ,
2154 unsigned int r_type
,
2155 const elfcpp::Sym
<32, false>&)
2157 return possible_function_pointer_reloc(r_type
);
2161 Target_i386::Scan::global_reloc_may_be_function_pointer(
2165 Sized_relobj_file
<32, false>* ,
2168 const elfcpp::Rel
<32, false>& ,
2169 unsigned int r_type
,
2172 return possible_function_pointer_reloc(r_type
);
2175 // Scan a relocation for a global symbol.
2178 Target_i386::Scan::global(Symbol_table
* symtab
,
2180 Target_i386
* target
,
2181 Sized_relobj_file
<32, false>* object
,
2182 unsigned int data_shndx
,
2183 Output_section
* output_section
,
2184 const elfcpp::Rel
<32, false>& reloc
,
2185 unsigned int r_type
,
2188 // A STT_GNU_IFUNC symbol may require a PLT entry.
2189 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
2190 && this->reloc_needs_plt_for_ifunc(object
, r_type
))
2191 target
->make_plt_entry(symtab
, layout
, gsym
);
2195 case elfcpp::R_386_NONE
:
2196 case elfcpp::R_386_GNU_VTINHERIT
:
2197 case elfcpp::R_386_GNU_VTENTRY
:
2200 case elfcpp::R_386_32
:
2201 case elfcpp::R_386_16
:
2202 case elfcpp::R_386_8
:
2204 // Make a PLT entry if necessary.
2205 if (gsym
->needs_plt_entry())
2207 target
->make_plt_entry(symtab
, layout
, gsym
);
2208 // Since this is not a PC-relative relocation, we may be
2209 // taking the address of a function. In that case we need to
2210 // set the entry in the dynamic symbol table to the address of
2212 if (gsym
->is_from_dynobj() && !parameters
->options().shared())
2213 gsym
->set_needs_dynsym_value();
2215 // Make a dynamic relocation if necessary.
2216 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
2218 if (!parameters
->options().output_is_position_independent()
2219 && gsym
->may_need_copy_reloc())
2221 target
->copy_reloc(symtab
, layout
, object
,
2222 data_shndx
, output_section
, gsym
, reloc
);
2224 else if (r_type
== elfcpp::R_386_32
2225 && gsym
->type() == elfcpp::STT_GNU_IFUNC
2226 && gsym
->can_use_relative_reloc(false)
2227 && !gsym
->is_from_dynobj()
2228 && !gsym
->is_undefined()
2229 && !gsym
->is_preemptible())
2231 // Use an IRELATIVE reloc for a locally defined
2232 // STT_GNU_IFUNC symbol. This makes a function
2233 // address in a PIE executable match the address in a
2234 // shared library that it links against.
2235 Reloc_section
* rel_dyn
= target
->rel_irelative_section(layout
);
2236 rel_dyn
->add_symbolless_global_addend(gsym
,
2237 elfcpp::R_386_IRELATIVE
,
2240 reloc
.get_r_offset());
2242 else if (r_type
== elfcpp::R_386_32
2243 && gsym
->can_use_relative_reloc(false))
2245 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2246 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
2247 output_section
, object
,
2248 data_shndx
, reloc
.get_r_offset());
2252 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2253 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
2254 data_shndx
, reloc
.get_r_offset());
2260 case elfcpp::R_386_PC32
:
2261 case elfcpp::R_386_PC16
:
2262 case elfcpp::R_386_PC8
:
2264 // Make a PLT entry if necessary.
2265 if (gsym
->needs_plt_entry())
2267 // These relocations are used for function calls only in
2268 // non-PIC code. For a 32-bit relocation in a shared library,
2269 // we'll need a text relocation anyway, so we can skip the
2270 // PLT entry and let the dynamic linker bind the call directly
2271 // to the target. For smaller relocations, we should use a
2272 // PLT entry to ensure that the call can reach.
2273 if (!parameters
->options().shared()
2274 || r_type
!= elfcpp::R_386_PC32
)
2275 target
->make_plt_entry(symtab
, layout
, gsym
);
2277 // Make a dynamic relocation if necessary.
2278 if (gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
)))
2280 if (parameters
->options().output_is_executable()
2281 && gsym
->may_need_copy_reloc())
2283 target
->copy_reloc(symtab
, layout
, object
,
2284 data_shndx
, output_section
, gsym
, reloc
);
2288 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2289 rel_dyn
->add_global(gsym
, r_type
, output_section
, object
,
2290 data_shndx
, reloc
.get_r_offset());
2296 case elfcpp::R_386_GOT32
:
2297 case elfcpp::R_386_GOT32X
:
2299 // The symbol requires a GOT section.
2300 Output_data_got
<32, false>* got
= target
->got_section(symtab
, layout
);
2302 // If we convert this from
2303 // mov foo@GOT(%reg), %reg
2305 // lea foo@GOTOFF(%reg), %reg
2306 // in Relocate::relocate, then there is nothing to do here.
2307 if (reloc
.get_r_offset() >= 2
2308 && Target_i386::can_convert_mov_to_lea(gsym
))
2310 section_size_type stype
;
2311 const unsigned char* view
= object
->section_contents(data_shndx
,
2313 if (view
[reloc
.get_r_offset() - 2] == 0x8b)
2317 if (gsym
->final_value_is_known())
2319 // For a STT_GNU_IFUNC symbol we want the PLT address.
2320 if (gsym
->type() == elfcpp::STT_GNU_IFUNC
)
2321 got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
2323 got
->add_global(gsym
, GOT_TYPE_STANDARD
);
2327 // If this symbol is not fully resolved, we need to add a
2328 // GOT entry with a dynamic relocation.
2329 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2331 // Use a GLOB_DAT rather than a RELATIVE reloc if:
2333 // 1) The symbol may be defined in some other module.
2335 // 2) We are building a shared library and this is a
2336 // protected symbol; using GLOB_DAT means that the dynamic
2337 // linker can use the address of the PLT in the main
2338 // executable when appropriate so that function address
2339 // comparisons work.
2341 // 3) This is a STT_GNU_IFUNC symbol in position dependent
2342 // code, again so that function address comparisons work.
2343 if (gsym
->is_from_dynobj()
2344 || gsym
->is_undefined()
2345 || gsym
->is_preemptible()
2346 || (gsym
->visibility() == elfcpp::STV_PROTECTED
2347 && parameters
->options().shared())
2348 || (gsym
->type() == elfcpp::STT_GNU_IFUNC
2349 && parameters
->options().output_is_position_independent()))
2350 got
->add_global_with_rel(gsym
, GOT_TYPE_STANDARD
,
2351 rel_dyn
, elfcpp::R_386_GLOB_DAT
);
2354 // For a STT_GNU_IFUNC symbol we want to write the PLT
2355 // offset into the GOT, so that function pointer
2356 // comparisons work correctly.
2358 if (gsym
->type() != elfcpp::STT_GNU_IFUNC
)
2359 is_new
= got
->add_global(gsym
, GOT_TYPE_STANDARD
);
2362 is_new
= got
->add_global_plt(gsym
, GOT_TYPE_STANDARD
);
2363 // Tell the dynamic linker to use the PLT address
2364 // when resolving relocations.
2365 if (gsym
->is_from_dynobj()
2366 && !parameters
->options().shared())
2367 gsym
->set_needs_dynsym_value();
2371 unsigned int got_off
= gsym
->got_offset(GOT_TYPE_STANDARD
);
2372 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
2380 case elfcpp::R_386_PLT32
:
2381 // If the symbol is fully resolved, this is just a PC32 reloc.
2382 // Otherwise we need a PLT entry.
2383 if (gsym
->final_value_is_known())
2385 // If building a shared library, we can also skip the PLT entry
2386 // if the symbol is defined in the output file and is protected
2388 if (gsym
->is_defined()
2389 && !gsym
->is_from_dynobj()
2390 && !gsym
->is_preemptible())
2392 target
->make_plt_entry(symtab
, layout
, gsym
);
2395 case elfcpp::R_386_GOTOFF
:
2396 case elfcpp::R_386_GOTPC
:
2397 // We need a GOT section.
2398 target
->got_section(symtab
, layout
);
2401 // These are relocations which should only be seen by the
2402 // dynamic linker, and should never be seen here.
2403 case elfcpp::R_386_COPY
:
2404 case elfcpp::R_386_GLOB_DAT
:
2405 case elfcpp::R_386_JUMP_SLOT
:
2406 case elfcpp::R_386_RELATIVE
:
2407 case elfcpp::R_386_IRELATIVE
:
2408 case elfcpp::R_386_TLS_TPOFF
:
2409 case elfcpp::R_386_TLS_DTPMOD32
:
2410 case elfcpp::R_386_TLS_DTPOFF32
:
2411 case elfcpp::R_386_TLS_TPOFF32
:
2412 case elfcpp::R_386_TLS_DESC
:
2413 gold_error(_("%s: unexpected reloc %u in object file"),
2414 object
->name().c_str(), r_type
);
2417 // These are initial tls relocs, which are expected when
2419 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2420 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2421 case elfcpp::R_386_TLS_DESC_CALL
:
2422 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2423 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2424 case elfcpp::R_386_TLS_IE
: // Initial-exec
2425 case elfcpp::R_386_TLS_IE_32
:
2426 case elfcpp::R_386_TLS_GOTIE
:
2427 case elfcpp::R_386_TLS_LE
: // Local-exec
2428 case elfcpp::R_386_TLS_LE_32
:
2430 const bool is_final
= gsym
->final_value_is_known();
2431 const tls::Tls_optimization optimized_type
2432 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
2435 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2436 if (optimized_type
== tls::TLSOPT_NONE
)
2438 // Create a pair of GOT entries for the module index and
2439 // dtv-relative offset.
2440 Output_data_got
<32, false>* got
2441 = target
->got_section(symtab
, layout
);
2442 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_PAIR
,
2443 target
->rel_dyn_section(layout
),
2444 elfcpp::R_386_TLS_DTPMOD32
,
2445 elfcpp::R_386_TLS_DTPOFF32
);
2447 else if (optimized_type
== tls::TLSOPT_TO_IE
)
2449 // Create a GOT entry for the tp-relative offset.
2450 Output_data_got
<32, false>* got
2451 = target
->got_section(symtab
, layout
);
2452 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
2453 target
->rel_dyn_section(layout
),
2454 elfcpp::R_386_TLS_TPOFF
);
2456 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2457 unsupported_reloc_global(object
, r_type
, gsym
);
2460 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (~oliva url)
2461 target
->define_tls_base_symbol(symtab
, layout
);
2462 if (optimized_type
== tls::TLSOPT_NONE
)
2464 // Create a double GOT entry with an R_386_TLS_DESC
2465 // reloc. The R_386_TLS_DESC reloc is resolved
2466 // lazily, so the GOT entry needs to be in an area in
2467 // .got.plt, not .got. Call got_section to make sure
2468 // the section has been created.
2469 target
->got_section(symtab
, layout
);
2470 Output_data_got
<32, false>* got
= target
->got_tlsdesc_section();
2471 Reloc_section
* rt
= target
->rel_tls_desc_section(layout
);
2472 got
->add_global_pair_with_rel(gsym
, GOT_TYPE_TLS_DESC
, rt
,
2473 elfcpp::R_386_TLS_DESC
, 0);
2475 else if (optimized_type
== tls::TLSOPT_TO_IE
)
2477 // Create a GOT entry for the tp-relative offset.
2478 Output_data_got
<32, false>* got
2479 = target
->got_section(symtab
, layout
);
2480 got
->add_global_with_rel(gsym
, GOT_TYPE_TLS_NOFFSET
,
2481 target
->rel_dyn_section(layout
),
2482 elfcpp::R_386_TLS_TPOFF
);
2484 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2485 unsupported_reloc_global(object
, r_type
, gsym
);
2488 case elfcpp::R_386_TLS_DESC_CALL
:
2491 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2492 if (optimized_type
== tls::TLSOPT_NONE
)
2494 // Create a GOT entry for the module index.
2495 target
->got_mod_index_entry(symtab
, layout
, object
);
2497 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2498 unsupported_reloc_global(object
, r_type
, gsym
);
2501 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2504 case elfcpp::R_386_TLS_IE
: // Initial-exec
2505 case elfcpp::R_386_TLS_IE_32
:
2506 case elfcpp::R_386_TLS_GOTIE
:
2507 layout
->set_has_static_tls();
2508 if (optimized_type
== tls::TLSOPT_NONE
)
2510 // For the R_386_TLS_IE relocation, we need to create a
2511 // dynamic relocation when building a shared library.
2512 if (r_type
== elfcpp::R_386_TLS_IE
2513 && parameters
->options().shared())
2515 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2516 rel_dyn
->add_global_relative(gsym
, elfcpp::R_386_RELATIVE
,
2517 output_section
, object
,
2519 reloc
.get_r_offset());
2521 // Create a GOT entry for the tp-relative offset.
2522 Output_data_got
<32, false>* got
2523 = target
->got_section(symtab
, layout
);
2524 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2525 ? elfcpp::R_386_TLS_TPOFF32
2526 : elfcpp::R_386_TLS_TPOFF
);
2527 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
2528 ? GOT_TYPE_TLS_OFFSET
2529 : GOT_TYPE_TLS_NOFFSET
);
2530 got
->add_global_with_rel(gsym
, got_type
,
2531 target
->rel_dyn_section(layout
),
2534 else if (optimized_type
!= tls::TLSOPT_TO_LE
)
2535 unsupported_reloc_global(object
, r_type
, gsym
);
2538 case elfcpp::R_386_TLS_LE
: // Local-exec
2539 case elfcpp::R_386_TLS_LE_32
:
2540 layout
->set_has_static_tls();
2541 if (parameters
->options().shared())
2543 // We need to create a dynamic relocation.
2544 unsigned int dyn_r_type
= (r_type
== elfcpp::R_386_TLS_LE_32
2545 ? elfcpp::R_386_TLS_TPOFF32
2546 : elfcpp::R_386_TLS_TPOFF
);
2547 Reloc_section
* rel_dyn
= target
->rel_dyn_section(layout
);
2548 rel_dyn
->add_global(gsym
, dyn_r_type
, output_section
, object
,
2549 data_shndx
, reloc
.get_r_offset());
2559 case elfcpp::R_386_32PLT
:
2560 case elfcpp::R_386_TLS_GD_32
:
2561 case elfcpp::R_386_TLS_GD_PUSH
:
2562 case elfcpp::R_386_TLS_GD_CALL
:
2563 case elfcpp::R_386_TLS_GD_POP
:
2564 case elfcpp::R_386_TLS_LDM_32
:
2565 case elfcpp::R_386_TLS_LDM_PUSH
:
2566 case elfcpp::R_386_TLS_LDM_CALL
:
2567 case elfcpp::R_386_TLS_LDM_POP
:
2568 case elfcpp::R_386_USED_BY_INTEL_200
:
2570 unsupported_reloc_global(object
, r_type
, gsym
);
2575 // Process relocations for gc.
2578 Target_i386::gc_process_relocs(Symbol_table
* symtab
,
2580 Sized_relobj_file
<32, false>* object
,
2581 unsigned int data_shndx
,
2583 const unsigned char* prelocs
,
2585 Output_section
* output_section
,
2586 bool needs_special_offset_handling
,
2587 size_t local_symbol_count
,
2588 const unsigned char* plocal_symbols
)
2590 gold::gc_process_relocs
<32, false, Target_i386
, Scan
, Classify_reloc
>(
2599 needs_special_offset_handling
,
2604 // Scan relocations for a section.
2607 Target_i386::scan_relocs(Symbol_table
* symtab
,
2609 Sized_relobj_file
<32, false>* object
,
2610 unsigned int data_shndx
,
2611 unsigned int sh_type
,
2612 const unsigned char* prelocs
,
2614 Output_section
* output_section
,
2615 bool needs_special_offset_handling
,
2616 size_t local_symbol_count
,
2617 const unsigned char* plocal_symbols
)
2619 if (sh_type
== elfcpp::SHT_RELA
)
2621 gold_error(_("%s: unsupported RELA reloc section"),
2622 object
->name().c_str());
2626 gold::scan_relocs
<32, false, Target_i386
, Scan
, Classify_reloc
>(
2635 needs_special_offset_handling
,
2640 // Finalize the sections.
2643 Target_i386::do_finalize_sections(
2645 const Input_objects
*,
2646 Symbol_table
* symtab
)
2648 const Reloc_section
* rel_plt
= (this->plt_
== NULL
2650 : this->plt_
->rel_plt());
2651 layout
->add_target_dynamic_tags(true, this->got_plt_
, rel_plt
,
2652 this->rel_dyn_
, true, false);
2654 // Emit any relocs we saved in an attempt to avoid generating COPY
2656 if (this->copy_relocs_
.any_saved_relocs())
2657 this->copy_relocs_
.emit(this->rel_dyn_section(layout
));
2659 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
2660 // the .got.plt section.
2661 Symbol
* sym
= this->global_offset_table_
;
2664 uint32_t data_size
= this->got_plt_
->current_data_size();
2665 symtab
->get_sized_symbol
<32>(sym
)->set_symsize(data_size
);
2668 if (parameters
->doing_static_link()
2669 && (this->plt_
== NULL
|| !this->plt_
->has_irelative_section()))
2671 // If linking statically, make sure that the __rel_iplt symbols
2672 // were defined if necessary, even if we didn't create a PLT.
2673 static const Define_symbol_in_segment syms
[] =
2676 "__rel_iplt_start", // name
2677 elfcpp::PT_LOAD
, // segment_type
2678 elfcpp::PF_W
, // segment_flags_set
2679 elfcpp::PF(0), // segment_flags_clear
2682 elfcpp::STT_NOTYPE
, // type
2683 elfcpp::STB_GLOBAL
, // binding
2684 elfcpp::STV_HIDDEN
, // visibility
2686 Symbol::SEGMENT_START
, // offset_from_base
2690 "__rel_iplt_end", // name
2691 elfcpp::PT_LOAD
, // segment_type
2692 elfcpp::PF_W
, // segment_flags_set
2693 elfcpp::PF(0), // segment_flags_clear
2696 elfcpp::STT_NOTYPE
, // type
2697 elfcpp::STB_GLOBAL
, // binding
2698 elfcpp::STV_HIDDEN
, // visibility
2700 Symbol::SEGMENT_START
, // offset_from_base
2705 symtab
->define_symbols(layout
, 2, syms
,
2706 layout
->script_options()->saw_sections_clause());
2710 // Return whether a direct absolute static relocation needs to be applied.
2711 // In cases where Scan::local() or Scan::global() has created
2712 // a dynamic relocation other than R_386_RELATIVE, the addend
2713 // of the relocation is carried in the data, and we must not
2714 // apply the static relocation.
2717 Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol
<32>* gsym
,
2718 unsigned int r_type
,
2720 Output_section
* output_section
)
2722 // If the output section is not allocated, then we didn't call
2723 // scan_relocs, we didn't create a dynamic reloc, and we must apply
2725 if ((output_section
->flags() & elfcpp::SHF_ALLOC
) == 0)
2728 int ref_flags
= Scan::get_reference_flags(r_type
);
2730 // For local symbols, we will have created a non-RELATIVE dynamic
2731 // relocation only if (a) the output is position independent,
2732 // (b) the relocation is absolute (not pc- or segment-relative), and
2733 // (c) the relocation is not 32 bits wide.
2735 return !(parameters
->options().output_is_position_independent()
2736 && (ref_flags
& Symbol::ABSOLUTE_REF
)
2739 // For global symbols, we use the same helper routines used in the
2740 // scan pass. If we did not create a dynamic relocation, or if we
2741 // created a RELATIVE dynamic relocation, we should apply the static
2743 bool has_dyn
= gsym
->needs_dynamic_reloc(ref_flags
);
2744 bool is_rel
= (ref_flags
& Symbol::ABSOLUTE_REF
)
2745 && gsym
->can_use_relative_reloc(ref_flags
2746 & Symbol::FUNCTION_CALL
);
2747 return !has_dyn
|| is_rel
;
2750 // Perform a relocation.
2753 Target_i386::Relocate::relocate(const Relocate_info
<32, false>* relinfo
,
2755 Target_i386
* target
,
2756 Output_section
* output_section
,
2758 const unsigned char* preloc
,
2759 const Sized_symbol
<32>* gsym
,
2760 const Symbol_value
<32>* psymval
,
2761 unsigned char* view
,
2762 elfcpp::Elf_types
<32>::Elf_Addr address
,
2763 section_size_type view_size
)
2765 const elfcpp::Rel
<32, false> rel(preloc
);
2766 unsigned int r_type
= elfcpp::elf_r_type
<32>(rel
.get_r_info());
2768 if (this->skip_call_tls_get_addr_
)
2770 if ((r_type
!= elfcpp::R_386_PLT32
2771 && r_type
!= elfcpp::R_386_PC32
)
2773 || strcmp(gsym
->name(), "___tls_get_addr") != 0)
2774 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2775 _("missing expected TLS relocation"));
2778 this->skip_call_tls_get_addr_
= false;
2786 const Sized_relobj_file
<32, false>* object
= relinfo
->object
;
2788 // Pick the value to use for symbols defined in shared objects.
2789 Symbol_value
<32> symval
;
2791 && gsym
->type() == elfcpp::STT_GNU_IFUNC
2792 && r_type
== elfcpp::R_386_32
2793 && gsym
->needs_dynamic_reloc(Scan::get_reference_flags(r_type
))
2794 && gsym
->can_use_relative_reloc(false)
2795 && !gsym
->is_from_dynobj()
2796 && !gsym
->is_undefined()
2797 && !gsym
->is_preemptible())
2799 // In this case we are generating a R_386_IRELATIVE reloc. We
2800 // want to use the real value of the symbol, not the PLT offset.
2802 else if (gsym
!= NULL
2803 && gsym
->use_plt_offset(Scan::get_reference_flags(r_type
)))
2805 symval
.set_output_value(target
->plt_address_for_global(gsym
));
2808 else if (gsym
== NULL
&& psymval
->is_ifunc_symbol())
2810 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2811 if (object
->local_has_plt_offset(r_sym
))
2813 symval
.set_output_value(target
->plt_address_for_local(object
, r_sym
));
2822 case elfcpp::R_386_NONE
:
2823 case elfcpp::R_386_GNU_VTINHERIT
:
2824 case elfcpp::R_386_GNU_VTENTRY
:
2827 case elfcpp::R_386_32
:
2828 if (should_apply_static_reloc(gsym
, r_type
, true, output_section
))
2829 Relocate_functions
<32, false>::rel32(view
, object
, psymval
);
2832 case elfcpp::R_386_PC32
:
2833 if (should_apply_static_reloc(gsym
, r_type
, true, output_section
))
2834 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
2837 case elfcpp::R_386_16
:
2838 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2839 Relocate_functions
<32, false>::rel16(view
, object
, psymval
);
2842 case elfcpp::R_386_PC16
:
2843 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2844 Relocate_functions
<32, false>::pcrel16(view
, object
, psymval
, address
);
2847 case elfcpp::R_386_8
:
2848 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2849 Relocate_functions
<32, false>::rel8(view
, object
, psymval
);
2852 case elfcpp::R_386_PC8
:
2853 if (should_apply_static_reloc(gsym
, r_type
, false, output_section
))
2854 Relocate_functions
<32, false>::pcrel8(view
, object
, psymval
, address
);
2857 case elfcpp::R_386_PLT32
:
2858 gold_assert(gsym
== NULL
2859 || gsym
->has_plt_offset()
2860 || gsym
->final_value_is_known()
2861 || (gsym
->is_defined()
2862 && !gsym
->is_from_dynobj()
2863 && !gsym
->is_preemptible()));
2864 Relocate_functions
<32, false>::pcrel32(view
, object
, psymval
, address
);
2867 case elfcpp::R_386_GOT32
:
2868 case elfcpp::R_386_GOT32X
:
2869 baseless
= (view
[-1] & 0xc7) == 0x5;
2870 // R_386_GOT32 and R_386_GOT32X don't work without base register
2871 // when generating a position-independent output file.
2873 && parameters
->options().output_is_position_independent())
2876 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2877 _("unexpected reloc %u against global symbol %s without base register in object file when generating a position-independent output file"),
2878 r_type
, gsym
->demangled_name().c_str());
2880 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2881 _("unexpected reloc %u against local symbol without base register in object file when generating a position-independent output file"),
2886 // mov foo@GOT(%reg), %reg
2888 // lea foo@GOTOFF(%reg), %reg
2890 if (rel
.get_r_offset() >= 2
2892 && ((gsym
== NULL
&& !psymval
->is_ifunc_symbol())
2894 && Target_i386::can_convert_mov_to_lea(gsym
))))
2897 elfcpp::Elf_types
<32>::Elf_Addr value
;
2898 value
= psymval
->value(object
, 0);
2899 // Don't subtract the .got.plt section address for baseless
2902 value
-= target
->got_plt_section()->address();
2903 Relocate_functions
<32, false>::rel32(view
, value
);
2907 // The GOT pointer points to the end of the GOT section.
2908 // We need to subtract the size of the GOT section to get
2909 // the actual offset to use in the relocation.
2910 unsigned int got_offset
= 0;
2913 gold_assert(gsym
->has_got_offset(GOT_TYPE_STANDARD
));
2914 got_offset
= (gsym
->got_offset(GOT_TYPE_STANDARD
)
2915 - target
->got_size());
2919 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
2920 gold_assert(object
->local_has_got_offset(r_sym
, GOT_TYPE_STANDARD
));
2921 got_offset
= (object
->local_got_offset(r_sym
, GOT_TYPE_STANDARD
)
2922 - target
->got_size());
2924 // Add the .got.plt section address for baseless addressing.
2926 got_offset
+= target
->got_plt_section()->address();
2927 Relocate_functions
<32, false>::rel32(view
, got_offset
);
2931 case elfcpp::R_386_GOTOFF
:
2933 elfcpp::Elf_types
<32>::Elf_Addr value
;
2934 value
= (psymval
->value(object
, 0)
2935 - target
->got_plt_section()->address());
2936 Relocate_functions
<32, false>::rel32(view
, value
);
2940 case elfcpp::R_386_GOTPC
:
2942 elfcpp::Elf_types
<32>::Elf_Addr value
;
2943 value
= target
->got_plt_section()->address();
2944 Relocate_functions
<32, false>::pcrel32(view
, value
, address
);
2948 case elfcpp::R_386_COPY
:
2949 case elfcpp::R_386_GLOB_DAT
:
2950 case elfcpp::R_386_JUMP_SLOT
:
2951 case elfcpp::R_386_RELATIVE
:
2952 case elfcpp::R_386_IRELATIVE
:
2953 // These are outstanding tls relocs, which are unexpected when
2955 case elfcpp::R_386_TLS_TPOFF
:
2956 case elfcpp::R_386_TLS_DTPMOD32
:
2957 case elfcpp::R_386_TLS_DTPOFF32
:
2958 case elfcpp::R_386_TLS_TPOFF32
:
2959 case elfcpp::R_386_TLS_DESC
:
2960 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2961 _("unexpected reloc %u in object file"),
2965 // These are initial tls relocs, which are expected when
2967 case elfcpp::R_386_TLS_GD
: // Global-dynamic
2968 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
2969 case elfcpp::R_386_TLS_DESC_CALL
:
2970 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
2971 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
2972 case elfcpp::R_386_TLS_IE
: // Initial-exec
2973 case elfcpp::R_386_TLS_IE_32
:
2974 case elfcpp::R_386_TLS_GOTIE
:
2975 case elfcpp::R_386_TLS_LE
: // Local-exec
2976 case elfcpp::R_386_TLS_LE_32
:
2977 this->relocate_tls(relinfo
, target
, relnum
, rel
, r_type
, gsym
, psymval
,
2978 view
, address
, view_size
);
2981 case elfcpp::R_386_32PLT
:
2982 case elfcpp::R_386_TLS_GD_32
:
2983 case elfcpp::R_386_TLS_GD_PUSH
:
2984 case elfcpp::R_386_TLS_GD_CALL
:
2985 case elfcpp::R_386_TLS_GD_POP
:
2986 case elfcpp::R_386_TLS_LDM_32
:
2987 case elfcpp::R_386_TLS_LDM_PUSH
:
2988 case elfcpp::R_386_TLS_LDM_CALL
:
2989 case elfcpp::R_386_TLS_LDM_POP
:
2990 case elfcpp::R_386_USED_BY_INTEL_200
:
2992 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
2993 _("unsupported reloc %u"),
3001 // Perform a TLS relocation.
3004 Target_i386::Relocate::relocate_tls(const Relocate_info
<32, false>* relinfo
,
3005 Target_i386
* target
,
3007 const elfcpp::Rel
<32, false>& rel
,
3008 unsigned int r_type
,
3009 const Sized_symbol
<32>* gsym
,
3010 const Symbol_value
<32>* psymval
,
3011 unsigned char* view
,
3012 elfcpp::Elf_types
<32>::Elf_Addr
,
3013 section_size_type view_size
)
3015 Output_segment
* tls_segment
= relinfo
->layout
->tls_segment();
3017 const Sized_relobj_file
<32, false>* object
= relinfo
->object
;
3019 elfcpp::Elf_types
<32>::Elf_Addr value
= psymval
->value(object
, 0);
3021 const bool is_final
= (gsym
== NULL
3022 ? !parameters
->options().shared()
3023 : gsym
->final_value_is_known());
3024 const tls::Tls_optimization optimized_type
3025 = Target_i386::optimize_tls_reloc(is_final
, r_type
);
3028 case elfcpp::R_386_TLS_GD
: // Global-dynamic
3029 if (optimized_type
== tls::TLSOPT_TO_LE
)
3031 if (tls_segment
== NULL
)
3033 gold_assert(parameters
->errors()->error_count() > 0
3034 || issue_undefined_symbol_error(gsym
));
3037 this->tls_gd_to_le(relinfo
, relnum
, tls_segment
,
3038 rel
, r_type
, value
, view
,
3044 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
3045 ? GOT_TYPE_TLS_NOFFSET
3046 : GOT_TYPE_TLS_PAIR
);
3047 unsigned int got_offset
;
3050 gold_assert(gsym
->has_got_offset(got_type
));
3051 got_offset
= gsym
->got_offset(got_type
) - target
->got_size();
3055 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
3056 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
3057 got_offset
= (object
->local_got_offset(r_sym
, got_type
)
3058 - target
->got_size());
3060 if (optimized_type
== tls::TLSOPT_TO_IE
)
3062 this->tls_gd_to_ie(relinfo
, relnum
, rel
, r_type
,
3063 got_offset
, view
, view_size
);
3066 else if (optimized_type
== tls::TLSOPT_NONE
)
3068 // Relocate the field with the offset of the pair of GOT
3070 Relocate_functions
<32, false>::rel32(view
, got_offset
);
3074 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3075 _("unsupported reloc %u"),
3079 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
3080 case elfcpp::R_386_TLS_DESC_CALL
:
3081 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
3082 if (optimized_type
== tls::TLSOPT_TO_LE
)
3084 if (tls_segment
== NULL
)
3086 gold_assert(parameters
->errors()->error_count() > 0
3087 || issue_undefined_symbol_error(gsym
));
3090 this->tls_desc_gd_to_le(relinfo
, relnum
, tls_segment
,
3091 rel
, r_type
, value
, view
,
3097 unsigned int got_type
= (optimized_type
== tls::TLSOPT_TO_IE
3098 ? GOT_TYPE_TLS_NOFFSET
3099 : GOT_TYPE_TLS_DESC
);
3100 unsigned int got_offset
= 0;
3101 if (r_type
== elfcpp::R_386_TLS_GOTDESC
3102 && optimized_type
== tls::TLSOPT_NONE
)
3104 // We created GOT entries in the .got.tlsdesc portion of
3105 // the .got.plt section, but the offset stored in the
3106 // symbol is the offset within .got.tlsdesc.
3107 got_offset
= (target
->got_size()
3108 + target
->got_plt_section()->data_size());
3112 gold_assert(gsym
->has_got_offset(got_type
));
3113 got_offset
+= gsym
->got_offset(got_type
) - target
->got_size();
3117 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
3118 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
3119 got_offset
+= (object
->local_got_offset(r_sym
, got_type
)
3120 - target
->got_size());
3122 if (optimized_type
== tls::TLSOPT_TO_IE
)
3124 this->tls_desc_gd_to_ie(relinfo
, relnum
, rel
, r_type
,
3125 got_offset
, view
, view_size
);
3128 else if (optimized_type
== tls::TLSOPT_NONE
)
3130 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
3132 // Relocate the field with the offset of the pair of GOT
3134 Relocate_functions
<32, false>::rel32(view
, got_offset
);
3139 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3140 _("unsupported reloc %u"),
3144 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
3145 if (this->local_dynamic_type_
== LOCAL_DYNAMIC_SUN
)
3147 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3148 _("both SUN and GNU model "
3149 "TLS relocations"));
3152 this->local_dynamic_type_
= LOCAL_DYNAMIC_GNU
;
3153 if (optimized_type
== tls::TLSOPT_TO_LE
)
3155 if (tls_segment
== NULL
)
3157 gold_assert(parameters
->errors()->error_count() > 0
3158 || issue_undefined_symbol_error(gsym
));
3161 this->tls_ld_to_le(relinfo
, relnum
, tls_segment
, rel
, r_type
,
3162 value
, view
, view_size
);
3165 else if (optimized_type
== tls::TLSOPT_NONE
)
3167 // Relocate the field with the offset of the GOT entry for
3168 // the module index.
3169 unsigned int got_offset
;
3170 got_offset
= (target
->got_mod_index_entry(NULL
, NULL
, NULL
)
3171 - target
->got_size());
3172 Relocate_functions
<32, false>::rel32(view
, got_offset
);
3175 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3176 _("unsupported reloc %u"),
3180 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
3181 if (optimized_type
== tls::TLSOPT_TO_LE
)
3183 // This reloc can appear in debugging sections, in which
3184 // case we must not convert to local-exec. We decide what
3185 // to do based on whether the section is marked as
3186 // containing executable code. That is what the GNU linker
3188 elfcpp::Shdr
<32, false> shdr(relinfo
->data_shdr
);
3189 if ((shdr
.get_sh_flags() & elfcpp::SHF_EXECINSTR
) != 0)
3191 if (tls_segment
== NULL
)
3193 gold_assert(parameters
->errors()->error_count() > 0
3194 || issue_undefined_symbol_error(gsym
));
3197 value
-= tls_segment
->memsz();
3200 Relocate_functions
<32, false>::rel32(view
, value
);
3203 case elfcpp::R_386_TLS_IE
: // Initial-exec
3204 case elfcpp::R_386_TLS_GOTIE
:
3205 case elfcpp::R_386_TLS_IE_32
:
3206 if (optimized_type
== tls::TLSOPT_TO_LE
)
3208 if (tls_segment
== NULL
)
3210 gold_assert(parameters
->errors()->error_count() > 0
3211 || issue_undefined_symbol_error(gsym
));
3214 Target_i386::Relocate::tls_ie_to_le(relinfo
, relnum
, tls_segment
,
3215 rel
, r_type
, value
, view
,
3219 else if (optimized_type
== tls::TLSOPT_NONE
)
3221 // Relocate the field with the offset of the GOT entry for
3222 // the tp-relative offset of the symbol.
3223 unsigned int got_type
= (r_type
== elfcpp::R_386_TLS_IE_32
3224 ? GOT_TYPE_TLS_OFFSET
3225 : GOT_TYPE_TLS_NOFFSET
);
3226 unsigned int got_offset
;
3229 gold_assert(gsym
->has_got_offset(got_type
));
3230 got_offset
= gsym
->got_offset(got_type
);
3234 unsigned int r_sym
= elfcpp::elf_r_sym
<32>(rel
.get_r_info());
3235 gold_assert(object
->local_has_got_offset(r_sym
, got_type
));
3236 got_offset
= object
->local_got_offset(r_sym
, got_type
);
3238 // For the R_386_TLS_IE relocation, we need to apply the
3239 // absolute address of the GOT entry.
3240 if (r_type
== elfcpp::R_386_TLS_IE
)
3241 got_offset
+= target
->got_plt_section()->address();
3242 // All GOT offsets are relative to the end of the GOT.
3243 got_offset
-= target
->got_size();
3244 Relocate_functions
<32, false>::rel32(view
, got_offset
);
3247 gold_error_at_location(relinfo
, relnum
, rel
.get_r_offset(),
3248 _("unsupported reloc %u"),
3252 case elfcpp::R_386_TLS_LE
: // Local-exec
3253 // If we're creating a shared library, a dynamic relocation will
3254 // have been created for this location, so do not apply it now.
3255 if (!parameters
->options().shared())
3257 if (tls_segment
== NULL
)
3259 gold_assert(parameters
->errors()->error_count() > 0
3260 || issue_undefined_symbol_error(gsym
));
3263 value
-= tls_segment
->memsz();
3264 Relocate_functions
<32, false>::rel32(view
, value
);
3268 case elfcpp::R_386_TLS_LE_32
:
3269 // If we're creating a shared library, a dynamic relocation will
3270 // have been created for this location, so do not apply it now.
3271 if (!parameters
->options().shared())
3273 if (tls_segment
== NULL
)
3275 gold_assert(parameters
->errors()->error_count() > 0
3276 || issue_undefined_symbol_error(gsym
));
3279 value
= tls_segment
->memsz() - value
;
3280 Relocate_functions
<32, false>::rel32(view
, value
);
3286 // Do a relocation in which we convert a TLS General-Dynamic to a
3290 Target_i386::Relocate::tls_gd_to_le(const Relocate_info
<32, false>* relinfo
,
3292 Output_segment
* tls_segment
,
3293 const elfcpp::Rel
<32, false>& rel
,
3295 elfcpp::Elf_types
<32>::Elf_Addr value
,
3296 unsigned char* view
,
3297 section_size_type view_size
)
3299 // leal foo(,%reg,1),%eax; call ___tls_get_addr
3300 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
3301 // leal foo(%reg),%eax; call ___tls_get_addr
3302 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
3304 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3305 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
3307 unsigned char op1
= view
[-1];
3308 unsigned char op2
= view
[-2];
3310 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3311 op2
== 0x8d || op2
== 0x04);
3312 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
3318 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
3319 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
3320 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3321 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
3322 memcpy(view
- 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3326 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3327 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
3328 if (rel
.get_r_offset() + 9 < view_size
3331 // There is a trailing nop. Use the size byte subl.
3332 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
3337 // Use the five byte subl.
3338 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
3342 value
= tls_segment
->memsz() - value
;
3343 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
3345 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3347 this->skip_call_tls_get_addr_
= true;
3350 // Do a relocation in which we convert a TLS General-Dynamic to an
3354 Target_i386::Relocate::tls_gd_to_ie(const Relocate_info
<32, false>* relinfo
,
3356 const elfcpp::Rel
<32, false>& rel
,
3358 elfcpp::Elf_types
<32>::Elf_Addr value
,
3359 unsigned char* view
,
3360 section_size_type view_size
)
3362 // leal foo(,%ebx,1),%eax; call ___tls_get_addr
3363 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
3364 // leal foo(%ebx),%eax; call ___tls_get_addr; nop
3365 // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
3367 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3368 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
3370 unsigned char op1
= view
[-1];
3371 unsigned char op2
= view
[-2];
3373 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3374 op2
== 0x8d || op2
== 0x04);
3375 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
3381 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -3);
3382 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[-3] == 0x8d);
3383 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3384 ((op1
& 0xc7) == 0x05 && op1
!= (4 << 3)));
3389 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 10);
3390 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3391 (op1
& 0xf8) == 0x80 && (op1
& 7) != 4);
3392 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[9] == 0x90);
3396 memcpy(view
+ roff
- 8, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
3397 Relocate_functions
<32, false>::rel32(view
+ roff
, value
);
3399 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3401 this->skip_call_tls_get_addr_
= true;
3404 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3405 // General-Dynamic to a Local-Exec.
3408 Target_i386::Relocate::tls_desc_gd_to_le(
3409 const Relocate_info
<32, false>* relinfo
,
3411 Output_segment
* tls_segment
,
3412 const elfcpp::Rel
<32, false>& rel
,
3413 unsigned int r_type
,
3414 elfcpp::Elf_types
<32>::Elf_Addr value
,
3415 unsigned char* view
,
3416 section_size_type view_size
)
3418 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
3420 // leal foo@TLSDESC(%ebx), %eax
3421 // ==> leal foo@NTPOFF, %eax
3422 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3423 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3424 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3425 view
[-2] == 0x8d && view
[-1] == 0x83);
3427 value
-= tls_segment
->memsz();
3428 Relocate_functions
<32, false>::rel32(view
, value
);
3432 // call *foo@TLSCALL(%eax)
3434 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
3435 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
3436 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3437 view
[0] == 0xff && view
[1] == 0x10);
3443 // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
3444 // General-Dynamic to an Initial-Exec.
3447 Target_i386::Relocate::tls_desc_gd_to_ie(
3448 const Relocate_info
<32, false>* relinfo
,
3450 const elfcpp::Rel
<32, false>& rel
,
3451 unsigned int r_type
,
3452 elfcpp::Elf_types
<32>::Elf_Addr value
,
3453 unsigned char* view
,
3454 section_size_type view_size
)
3456 if (r_type
== elfcpp::R_386_TLS_GOTDESC
)
3458 // leal foo@TLSDESC(%ebx), %eax
3459 // ==> movl foo@GOTNTPOFF(%ebx), %eax
3460 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3461 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3462 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3463 view
[-2] == 0x8d && view
[-1] == 0x83);
3465 Relocate_functions
<32, false>::rel32(view
, value
);
3469 // call *foo@TLSCALL(%eax)
3471 gold_assert(r_type
== elfcpp::R_386_TLS_DESC_CALL
);
3472 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 2);
3473 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3474 view
[0] == 0xff && view
[1] == 0x10);
3480 // Do a relocation in which we convert a TLS Local-Dynamic to a
3484 Target_i386::Relocate::tls_ld_to_le(const Relocate_info
<32, false>* relinfo
,
3487 const elfcpp::Rel
<32, false>& rel
,
3489 elfcpp::Elf_types
<32>::Elf_Addr
,
3490 unsigned char* view
,
3491 section_size_type view_size
)
3493 // leal foo(%reg), %eax; call ___tls_get_addr
3494 // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
3496 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3497 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 9);
3499 // FIXME: Does this test really always pass?
3500 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3501 view
[-2] == 0x8d && view
[-1] == 0x83);
3503 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), view
[4] == 0xe8);
3505 memcpy(view
- 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
3507 // The next reloc should be a PLT32 reloc against __tls_get_addr.
3509 this->skip_call_tls_get_addr_
= true;
3512 // Do a relocation in which we convert a TLS Initial-Exec to a
3516 Target_i386::Relocate::tls_ie_to_le(const Relocate_info
<32, false>* relinfo
,
3518 Output_segment
* tls_segment
,
3519 const elfcpp::Rel
<32, false>& rel
,
3520 unsigned int r_type
,
3521 elfcpp::Elf_types
<32>::Elf_Addr value
,
3522 unsigned char* view
,
3523 section_size_type view_size
)
3525 // We have to actually change the instructions, which means that we
3526 // need to examine the opcodes to figure out which instruction we
3528 if (r_type
== elfcpp::R_386_TLS_IE
)
3530 // movl %gs:XX,%eax ==> movl $YY,%eax
3531 // movl %gs:XX,%reg ==> movl $YY,%reg
3532 // addl %gs:XX,%reg ==> addl $YY,%reg
3533 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -1);
3534 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3536 unsigned char op1
= view
[-1];
3539 // movl XX,%eax ==> movl $YY,%eax
3544 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3546 unsigned char op2
= view
[-2];
3549 // movl XX,%reg ==> movl $YY,%reg
3550 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3551 (op1
& 0xc7) == 0x05);
3553 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3555 else if (op2
== 0x03)
3557 // addl XX,%reg ==> addl $YY,%reg
3558 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3559 (op1
& 0xc7) == 0x05);
3561 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3564 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
3569 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
3570 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
3571 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
3572 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, -2);
3573 tls::check_range(relinfo
, relnum
, rel
.get_r_offset(), view_size
, 4);
3575 unsigned char op1
= view
[-1];
3576 unsigned char op2
= view
[-2];
3577 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(),
3578 (op1
& 0xc0) == 0x80 && (op1
& 7) != 4);
3581 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
3583 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3585 else if (op2
== 0x2b)
3587 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
3589 view
[-1] = 0xe8 | ((op1
>> 3) & 7);
3591 else if (op2
== 0x03)
3593 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
3595 view
[-1] = 0xc0 | ((op1
>> 3) & 7);
3598 tls::check_tls(relinfo
, relnum
, rel
.get_r_offset(), 0);
3601 value
= tls_segment
->memsz() - value
;
3602 if (r_type
== elfcpp::R_386_TLS_IE
|| r_type
== elfcpp::R_386_TLS_GOTIE
)
3605 Relocate_functions
<32, false>::rel32(view
, value
);
3608 // Relocate section data.
3611 Target_i386::relocate_section(const Relocate_info
<32, false>* relinfo
,
3612 unsigned int sh_type
,
3613 const unsigned char* prelocs
,
3615 Output_section
* output_section
,
3616 bool needs_special_offset_handling
,
3617 unsigned char* view
,
3618 elfcpp::Elf_types
<32>::Elf_Addr address
,
3619 section_size_type view_size
,
3620 const Reloc_symbol_changes
* reloc_symbol_changes
)
3622 gold_assert(sh_type
== elfcpp::SHT_REL
);
3624 gold::relocate_section
<32, false, Target_i386
, Relocate
,
3625 gold::Default_comdat_behavior
, Classify_reloc
>(
3631 needs_special_offset_handling
,
3635 reloc_symbol_changes
);
3638 // Return the size of a relocation while scanning during a relocatable
3642 Target_i386::Classify_reloc::get_size_for_reloc(
3643 unsigned int r_type
,
3648 case elfcpp::R_386_NONE
:
3649 case elfcpp::R_386_GNU_VTINHERIT
:
3650 case elfcpp::R_386_GNU_VTENTRY
:
3651 case elfcpp::R_386_TLS_GD
: // Global-dynamic
3652 case elfcpp::R_386_TLS_GOTDESC
: // Global-dynamic (from ~oliva url)
3653 case elfcpp::R_386_TLS_DESC_CALL
:
3654 case elfcpp::R_386_TLS_LDM
: // Local-dynamic
3655 case elfcpp::R_386_TLS_LDO_32
: // Alternate local-dynamic
3656 case elfcpp::R_386_TLS_IE
: // Initial-exec
3657 case elfcpp::R_386_TLS_IE_32
:
3658 case elfcpp::R_386_TLS_GOTIE
:
3659 case elfcpp::R_386_TLS_LE
: // Local-exec
3660 case elfcpp::R_386_TLS_LE_32
:
3663 case elfcpp::R_386_32
:
3664 case elfcpp::R_386_PC32
:
3665 case elfcpp::R_386_GOT32
:
3666 case elfcpp::R_386_GOT32X
:
3667 case elfcpp::R_386_PLT32
:
3668 case elfcpp::R_386_GOTOFF
:
3669 case elfcpp::R_386_GOTPC
:
3672 case elfcpp::R_386_16
:
3673 case elfcpp::R_386_PC16
:
3676 case elfcpp::R_386_8
:
3677 case elfcpp::R_386_PC8
:
3680 // These are relocations which should only be seen by the
3681 // dynamic linker, and should never be seen here.
3682 case elfcpp::R_386_COPY
:
3683 case elfcpp::R_386_GLOB_DAT
:
3684 case elfcpp::R_386_JUMP_SLOT
:
3685 case elfcpp::R_386_RELATIVE
:
3686 case elfcpp::R_386_IRELATIVE
:
3687 case elfcpp::R_386_TLS_TPOFF
:
3688 case elfcpp::R_386_TLS_DTPMOD32
:
3689 case elfcpp::R_386_TLS_DTPOFF32
:
3690 case elfcpp::R_386_TLS_TPOFF32
:
3691 case elfcpp::R_386_TLS_DESC
:
3692 object
->error(_("unexpected reloc %u in object file"), r_type
);
3695 case elfcpp::R_386_32PLT
:
3696 case elfcpp::R_386_TLS_GD_32
:
3697 case elfcpp::R_386_TLS_GD_PUSH
:
3698 case elfcpp::R_386_TLS_GD_CALL
:
3699 case elfcpp::R_386_TLS_GD_POP
:
3700 case elfcpp::R_386_TLS_LDM_32
:
3701 case elfcpp::R_386_TLS_LDM_PUSH
:
3702 case elfcpp::R_386_TLS_LDM_CALL
:
3703 case elfcpp::R_386_TLS_LDM_POP
:
3704 case elfcpp::R_386_USED_BY_INTEL_200
:
3706 object
->error(_("unsupported reloc %u in object file"), r_type
);
3711 // Scan the relocs during a relocatable link.
3714 Target_i386::scan_relocatable_relocs(Symbol_table
* symtab
,
3716 Sized_relobj_file
<32, false>* object
,
3717 unsigned int data_shndx
,
3718 unsigned int sh_type
,
3719 const unsigned char* prelocs
,
3721 Output_section
* output_section
,
3722 bool needs_special_offset_handling
,
3723 size_t local_symbol_count
,
3724 const unsigned char* plocal_symbols
,
3725 Relocatable_relocs
* rr
)
3727 typedef gold::Default_scan_relocatable_relocs
<Classify_reloc
>
3728 Scan_relocatable_relocs
;
3730 gold_assert(sh_type
== elfcpp::SHT_REL
);
3732 gold::scan_relocatable_relocs
<32, false, Scan_relocatable_relocs
>(
3740 needs_special_offset_handling
,
3746 // Scan the relocs for --emit-relocs.
3749 Target_i386::emit_relocs_scan(Symbol_table
* symtab
,
3751 Sized_relobj_file
<32, false>* object
,
3752 unsigned int data_shndx
,
3753 unsigned int sh_type
,
3754 const unsigned char* prelocs
,
3756 Output_section
* output_section
,
3757 bool needs_special_offset_handling
,
3758 size_t local_symbol_count
,
3759 const unsigned char* plocal_syms
,
3760 Relocatable_relocs
* rr
)
3762 typedef gold::Default_classify_reloc
<elfcpp::SHT_REL
, 32, false>
3764 typedef gold::Default_emit_relocs_strategy
<Classify_reloc
>
3765 Emit_relocs_strategy
;
3767 gold_assert(sh_type
== elfcpp::SHT_REL
);
3769 gold::scan_relocatable_relocs
<32, false, Emit_relocs_strategy
>(
3777 needs_special_offset_handling
,
3783 // Emit relocations for a section.
3786 Target_i386::relocate_relocs(
3787 const Relocate_info
<32, false>* relinfo
,
3788 unsigned int sh_type
,
3789 const unsigned char* prelocs
,
3791 Output_section
* output_section
,
3792 elfcpp::Elf_types
<32>::Elf_Off offset_in_output_section
,
3793 unsigned char* view
,
3794 elfcpp::Elf_types
<32>::Elf_Addr view_address
,
3795 section_size_type view_size
,
3796 unsigned char* reloc_view
,
3797 section_size_type reloc_view_size
)
3799 gold_assert(sh_type
== elfcpp::SHT_REL
);
3801 gold::relocate_relocs
<32, false, Classify_reloc
>(
3806 offset_in_output_section
,
3814 // Return the value to use for a dynamic which requires special
3815 // treatment. This is how we support equality comparisons of function
3816 // pointers across shared library boundaries, as described in the
3817 // processor specific ABI supplement.
3820 Target_i386::do_dynsym_value(const Symbol
* gsym
) const
3822 gold_assert(gsym
->is_from_dynobj() && gsym
->has_plt_offset());
3823 return this->plt_address_for_global(gsym
);
3826 // Return a string used to fill a code section with nops to take up
3827 // the specified length.
3830 Target_i386::do_code_fill(section_size_type length
) const
3834 // Build a jmp instruction to skip over the bytes.
3835 unsigned char jmp
[5];
3837 elfcpp::Swap_unaligned
<32, false>::writeval(jmp
+ 1, length
- 5);
3838 return (std::string(reinterpret_cast<char*>(&jmp
[0]), 5)
3839 + std::string(length
- 5, static_cast<char>(0x90)));
3842 // Nop sequences of various lengths.
3843 const char nop1
[1] = { '\x90' }; // nop
3844 const char nop2
[2] = { '\x66', '\x90' }; // xchg %ax %ax
3845 const char nop3
[3] = { '\x8d', '\x76', '\x00' }; // leal 0(%esi),%esi
3846 const char nop4
[4] = { '\x8d', '\x74', '\x26', // leal 0(%esi,1),%esi
3848 const char nop5
[5] = { '\x90', '\x8d', '\x74', // nop
3849 '\x26', '\x00' }; // leal 0(%esi,1),%esi
3850 const char nop6
[6] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3851 '\x00', '\x00', '\x00' };
3852 const char nop7
[7] = { '\x8d', '\xb4', '\x26', // leal 0L(%esi,1),%esi
3853 '\x00', '\x00', '\x00',
3855 const char nop8
[8] = { '\x90', '\x8d', '\xb4', // nop
3856 '\x26', '\x00', '\x00', // leal 0L(%esi,1),%esi
3858 const char nop9
[9] = { '\x89', '\xf6', '\x8d', // movl %esi,%esi
3859 '\xbc', '\x27', '\x00', // leal 0L(%edi,1),%edi
3860 '\x00', '\x00', '\x00' };
3861 const char nop10
[10] = { '\x8d', '\x76', '\x00', // leal 0(%esi),%esi
3862 '\x8d', '\xbc', '\x27', // leal 0L(%edi,1),%edi
3863 '\x00', '\x00', '\x00',
3865 const char nop11
[11] = { '\x8d', '\x74', '\x26', // leal 0(%esi,1),%esi
3866 '\x00', '\x8d', '\xbc', // leal 0L(%edi,1),%edi
3867 '\x27', '\x00', '\x00',
3869 const char nop12
[12] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3870 '\x00', '\x00', '\x00', // leal 0L(%edi),%edi
3871 '\x8d', '\xbf', '\x00',
3872 '\x00', '\x00', '\x00' };
3873 const char nop13
[13] = { '\x8d', '\xb6', '\x00', // leal 0L(%esi),%esi
3874 '\x00', '\x00', '\x00', // leal 0L(%edi,1),%edi
3875 '\x8d', '\xbc', '\x27',
3876 '\x00', '\x00', '\x00',
3878 const char nop14
[14] = { '\x8d', '\xb4', '\x26', // leal 0L(%esi,1),%esi
3879 '\x00', '\x00', '\x00', // leal 0L(%edi,1),%edi
3880 '\x00', '\x8d', '\xbc',
3881 '\x27', '\x00', '\x00',
3883 const char nop15
[15] = { '\xeb', '\x0d', '\x90', // jmp .+15
3884 '\x90', '\x90', '\x90', // nop,nop,nop,...
3885 '\x90', '\x90', '\x90',
3886 '\x90', '\x90', '\x90',
3887 '\x90', '\x90', '\x90' };
3889 const char* nops
[16] = {
3891 nop1
, nop2
, nop3
, nop4
, nop5
, nop6
, nop7
,
3892 nop8
, nop9
, nop10
, nop11
, nop12
, nop13
, nop14
, nop15
3895 return std::string(nops
[length
], length
);
3898 // Return the value to use for the base of a DW_EH_PE_datarel offset
3899 // in an FDE. Solaris and SVR4 use DW_EH_PE_datarel because their
3900 // assembler can not write out the difference between two labels in
3901 // different sections, so instead of using a pc-relative value they
3902 // use an offset from the GOT.
3905 Target_i386::do_ehframe_datarel_base() const
3907 gold_assert(this->global_offset_table_
!= NULL
);
3908 Symbol
* sym
= this->global_offset_table_
;
3909 Sized_symbol
<32>* ssym
= static_cast<Sized_symbol
<32>*>(sym
);
3910 return ssym
->value();
3913 // Return whether SYM should be treated as a call to a non-split
3914 // function. We don't want that to be true of a call to a
3915 // get_pc_thunk function.
3918 Target_i386::do_is_call_to_non_split(const Symbol
* sym
,
3919 const unsigned char*) const
3921 return (sym
->type() == elfcpp::STT_FUNC
3922 && !is_prefix_of("__i686.get_pc_thunk.", sym
->name()));
3925 // FNOFFSET in section SHNDX in OBJECT is the start of a function
3926 // compiled with -fsplit-stack. The function calls non-split-stack
3927 // code. We have to change the function so that it always ensures
3928 // that it has enough stack space to run some random function.
3931 Target_i386::do_calls_non_split(Relobj
* object
, unsigned int shndx
,
3932 section_offset_type fnoffset
,
3933 section_size_type fnsize
,
3934 const unsigned char*,
3936 unsigned char* view
,
3937 section_size_type view_size
,
3939 std::string
* to
) const
3941 // The function starts with a comparison of the stack pointer and a
3942 // field in the TCB. This is followed by a jump.
3945 if (this->match_view(view
, view_size
, fnoffset
, "\x65\x3b\x25", 3)
3948 // We will call __morestack if the carry flag is set after this
3949 // comparison. We turn the comparison into an stc instruction
3951 view
[fnoffset
] = '\xf9';
3952 this->set_view_to_nop(view
, view_size
, fnoffset
+ 1, 6);
3954 // lea NN(%esp),%ecx
3955 // lea NN(%esp),%edx
3956 else if ((this->match_view(view
, view_size
, fnoffset
, "\x8d\x8c\x24", 3)
3957 || this->match_view(view
, view_size
, fnoffset
, "\x8d\x94\x24", 3))
3960 // This is loading an offset from the stack pointer for a
3961 // comparison. The offset is negative, so we decrease the
3962 // offset by the amount of space we need for the stack. This
3963 // means we will avoid calling __morestack if there happens to
3964 // be plenty of space on the stack already.
3965 unsigned char* pval
= view
+ fnoffset
+ 3;
3966 uint32_t val
= elfcpp::Swap_unaligned
<32, false>::readval(pval
);
3967 val
-= parameters
->options().split_stack_adjust_size();
3968 elfcpp::Swap_unaligned
<32, false>::writeval(pval
, val
);
3972 if (!object
->has_no_split_stack())
3973 object
->error(_("failed to match split-stack sequence at "
3974 "section %u offset %0zx"),
3975 shndx
, static_cast<size_t>(fnoffset
));
3979 // We have to change the function so that it calls
3980 // __morestack_non_split instead of __morestack. The former will
3981 // allocate additional stack space.
3982 *from
= "__morestack";
3983 *to
= "__morestack_non_split";
3986 // The selector for i386 object files. Note this is never instantiated
3987 // directly. It's only used in Target_selector_i386_nacl, below.
3989 class Target_selector_i386
: public Target_selector_freebsd
3992 Target_selector_i386()
3993 : Target_selector_freebsd(elfcpp::EM_386
, 32, false,
3994 "elf32-i386", "elf32-i386-freebsd",
3999 do_instantiate_target()
4000 { return new Target_i386(); }
4003 // NaCl variant. It uses different PLT contents.
4005 class Output_data_plt_i386_nacl
: public Output_data_plt_i386
4008 Output_data_plt_i386_nacl(Layout
* layout
,
4009 Output_data_got_plt_i386
* got_plt
,
4010 Output_data_space
* got_irelative
)
4011 : Output_data_plt_i386(layout
, plt_entry_size
, got_plt
, got_irelative
)
4015 virtual unsigned int
4016 do_get_plt_entry_size() const
4017 { return plt_entry_size
; }
4020 do_add_eh_frame(Layout
* layout
)
4022 layout
->add_eh_frame_for_plt(this, plt_eh_frame_cie
, plt_eh_frame_cie_size
,
4023 plt_eh_frame_fde
, plt_eh_frame_fde_size
);
4026 // The size of an entry in the PLT.
4027 static const int plt_entry_size
= 64;
4029 // The .eh_frame unwind information for the PLT.
4030 static const int plt_eh_frame_fde_size
= 32;
4031 static const unsigned char plt_eh_frame_fde
[plt_eh_frame_fde_size
];
4034 class Output_data_plt_i386_nacl_exec
: public Output_data_plt_i386_nacl
4037 Output_data_plt_i386_nacl_exec(Layout
* layout
,
4038 Output_data_got_plt_i386
* got_plt
,
4039 Output_data_space
* got_irelative
)
4040 : Output_data_plt_i386_nacl(layout
, got_plt
, got_irelative
)
4045 do_fill_first_plt_entry(unsigned char* pov
,
4046 elfcpp::Elf_types
<32>::Elf_Addr got_address
);
4048 virtual unsigned int
4049 do_fill_plt_entry(unsigned char* pov
,
4050 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
4051 unsigned int got_offset
,
4052 unsigned int plt_offset
,
4053 unsigned int plt_rel_offset
);
4056 // The first entry in the PLT for an executable.
4057 static const unsigned char first_plt_entry
[plt_entry_size
];
4059 // Other entries in the PLT for an executable.
4060 static const unsigned char plt_entry
[plt_entry_size
];
4063 class Output_data_plt_i386_nacl_dyn
: public Output_data_plt_i386_nacl
4066 Output_data_plt_i386_nacl_dyn(Layout
* layout
,
4067 Output_data_got_plt_i386
* got_plt
,
4068 Output_data_space
* got_irelative
)
4069 : Output_data_plt_i386_nacl(layout
, got_plt
, got_irelative
)
4074 do_fill_first_plt_entry(unsigned char* pov
, elfcpp::Elf_types
<32>::Elf_Addr
);
4076 virtual unsigned int
4077 do_fill_plt_entry(unsigned char* pov
,
4078 elfcpp::Elf_types
<32>::Elf_Addr
,
4079 unsigned int got_offset
,
4080 unsigned int plt_offset
,
4081 unsigned int plt_rel_offset
);
4084 // The first entry in the PLT for a shared object.
4085 static const unsigned char first_plt_entry
[plt_entry_size
];
4087 // Other entries in the PLT for a shared object.
4088 static const unsigned char plt_entry
[plt_entry_size
];
4091 class Target_i386_nacl
: public Target_i386
4095 : Target_i386(&i386_nacl_info
)
4099 virtual Output_data_plt_i386
*
4100 do_make_data_plt(Layout
* layout
,
4101 Output_data_got_plt_i386
* got_plt
,
4102 Output_data_space
* got_irelative
,
4106 return new Output_data_plt_i386_nacl_dyn(layout
, got_plt
, got_irelative
);
4108 return new Output_data_plt_i386_nacl_exec(layout
, got_plt
, got_irelative
);
4112 do_code_fill(section_size_type length
) const;
4115 static const Target::Target_info i386_nacl_info
;
4118 const Target::Target_info
Target_i386_nacl::i386_nacl_info
=
4121 false, // is_big_endian
4122 elfcpp::EM_386
, // machine_code
4123 false, // has_make_symbol
4124 false, // has_resolve
4125 true, // has_code_fill
4126 true, // is_default_stack_executable
4127 true, // can_icf_inline_merge_sections
4129 "/lib/ld-nacl-x86-32.so.1", // dynamic_linker
4130 0x20000, // default_text_segment_address
4131 0x10000, // abi_pagesize (overridable by -z max-page-size)
4132 0x10000, // common_pagesize (overridable by -z common-page-size)
4133 true, // isolate_execinstr
4134 0x10000000, // rosegment_gap
4135 elfcpp::SHN_UNDEF
, // small_common_shndx
4136 elfcpp::SHN_UNDEF
, // large_common_shndx
4137 0, // small_common_section_flags
4138 0, // large_common_section_flags
4139 NULL
, // attributes_section
4140 NULL
, // attributes_vendor
4141 "_start", // entry_symbol_name
4142 32, // hash_entry_size
4145 #define NACLMASK 0xe0 // 32-byte alignment mask
4148 Output_data_plt_i386_nacl_exec::first_plt_entry
[plt_entry_size
] =
4150 0xff, 0x35, // pushl contents of memory address
4151 0, 0, 0, 0, // replaced with address of .got + 4
4152 0x8b, 0x0d, // movl contents of address, %ecx
4153 0, 0, 0, 0, // replaced with address of .got + 8
4154 0x83, 0xe1, NACLMASK
, // andl $NACLMASK, %ecx
4155 0xff, 0xe1, // jmp *%ecx
4156 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4157 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4158 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
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
4167 Output_data_plt_i386_nacl_exec::do_fill_first_plt_entry(
4169 elfcpp::Elf_types
<32>::Elf_Addr got_address
)
4171 memcpy(pov
, first_plt_entry
, plt_entry_size
);
4172 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_address
+ 4);
4173 elfcpp::Swap
<32, false>::writeval(pov
+ 8, got_address
+ 8);
4176 // The first entry in the PLT for a shared object.
4179 Output_data_plt_i386_nacl_dyn::first_plt_entry
[plt_entry_size
] =
4181 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
4182 0x8b, 0x4b, 0x08, // mov 0x8(%ebx), %ecx
4183 0x83, 0xe1, NACLMASK
, // andl $NACLMASK, %ecx
4184 0xff, 0xe1, // jmp *%ecx
4185 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4186 0x90, 0x90, 0x90, 0x90, 0x90, // nops
4187 0x90, 0x90, 0x90, 0x90, 0x90, // nops
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
4198 Output_data_plt_i386_nacl_dyn::do_fill_first_plt_entry(
4200 elfcpp::Elf_types
<32>::Elf_Addr
)
4202 memcpy(pov
, first_plt_entry
, plt_entry_size
);
4205 // Subsequent entries in the PLT for an executable.
4208 Output_data_plt_i386_nacl_exec::plt_entry
[plt_entry_size
] =
4210 0x8b, 0x0d, // movl contents of address, %ecx */
4211 0, 0, 0, 0, // replaced with address of symbol in .got
4212 0x83, 0xe1, NACLMASK
, // andl $NACLMASK, %ecx
4213 0xff, 0xe1, // jmp *%ecx
4215 // Pad to the next 32-byte boundary with nop instructions.
4217 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4218 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4220 // Lazy GOT entries point here (32-byte aligned).
4221 0x68, // pushl immediate
4222 0, 0, 0, 0, // replaced with offset into relocation table
4223 0xe9, // jmp relative
4224 0, 0, 0, 0, // replaced with offset to start of .plt
4226 // Pad to the next 32-byte boundary with nop instructions.
4227 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4228 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4233 Output_data_plt_i386_nacl_exec::do_fill_plt_entry(
4235 elfcpp::Elf_types
<32>::Elf_Addr got_address
,
4236 unsigned int got_offset
,
4237 unsigned int plt_offset
,
4238 unsigned int plt_rel_offset
)
4240 memcpy(pov
, plt_entry
, plt_entry_size
);
4241 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2,
4242 got_address
+ got_offset
);
4243 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 33, plt_rel_offset
);
4244 elfcpp::Swap
<32, false>::writeval(pov
+ 38, - (plt_offset
+ 38 + 4));
4248 // Subsequent entries in the PLT for a shared object.
4251 Output_data_plt_i386_nacl_dyn::plt_entry
[plt_entry_size
] =
4253 0x8b, 0x8b, // movl offset(%ebx), %ecx
4254 0, 0, 0, 0, // replaced with offset of symbol in .got
4255 0x83, 0xe1, 0xe0, // andl $NACLMASK, %ecx
4256 0xff, 0xe1, // jmp *%ecx
4258 // Pad to the next 32-byte boundary with nop instructions.
4260 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4261 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4263 // Lazy GOT entries point here (32-byte aligned).
4264 0x68, // pushl immediate
4265 0, 0, 0, 0, // replaced with offset into relocation table.
4266 0xe9, // jmp relative
4267 0, 0, 0, 0, // replaced with offset to start of .plt.
4269 // Pad to the next 32-byte boundary with nop instructions.
4270 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4271 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90,
4276 Output_data_plt_i386_nacl_dyn::do_fill_plt_entry(
4278 elfcpp::Elf_types
<32>::Elf_Addr
,
4279 unsigned int got_offset
,
4280 unsigned int plt_offset
,
4281 unsigned int plt_rel_offset
)
4283 memcpy(pov
, plt_entry
, plt_entry_size
);
4284 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 2, got_offset
);
4285 elfcpp::Swap_unaligned
<32, false>::writeval(pov
+ 33, plt_rel_offset
);
4286 elfcpp::Swap
<32, false>::writeval(pov
+ 38, - (plt_offset
+ 38 + 4));
4291 Output_data_plt_i386_nacl::plt_eh_frame_fde
[plt_eh_frame_fde_size
] =
4293 0, 0, 0, 0, // Replaced with offset to .plt.
4294 0, 0, 0, 0, // Replaced with size of .plt.
4295 0, // Augmentation size.
4296 elfcpp::DW_CFA_def_cfa_offset
, 8, // DW_CFA_def_cfa_offset: 8.
4297 elfcpp::DW_CFA_advance_loc
+ 6, // Advance 6 to __PLT__ + 6.
4298 elfcpp::DW_CFA_def_cfa_offset
, 12, // DW_CFA_def_cfa_offset: 12.
4299 elfcpp::DW_CFA_advance_loc
+ 58, // Advance 58 to __PLT__ + 64.
4300 elfcpp::DW_CFA_def_cfa_expression
, // DW_CFA_def_cfa_expression.
4301 13, // Block length.
4302 elfcpp::DW_OP_breg4
, 4, // Push %esp + 4.
4303 elfcpp::DW_OP_breg8
, 0, // Push %eip.
4304 elfcpp::DW_OP_const1u
, 63, // Push 0x3f.
4305 elfcpp::DW_OP_and
, // & (%eip & 0x3f).
4306 elfcpp::DW_OP_const1u
, 37, // Push 0x25.
4307 elfcpp::DW_OP_ge
, // >= ((%eip & 0x3f) >= 0x25)
4308 elfcpp::DW_OP_lit2
, // Push 2.
4309 elfcpp::DW_OP_shl
, // << (((%eip & 0x3f) >= 0x25) << 2)
4310 elfcpp::DW_OP_plus
, // + ((((%eip&0x3f)>=0x25)<<2)+%esp+4
4311 elfcpp::DW_CFA_nop
, // Align to 32 bytes.
4315 // Return a string used to fill a code section with nops.
4316 // For NaCl, long NOPs are only valid if they do not cross
4317 // bundle alignment boundaries, so keep it simple with one-byte NOPs.
4319 Target_i386_nacl::do_code_fill(section_size_type length
) const
4321 return std::string(length
, static_cast<char>(0x90));
4324 // The selector for i386-nacl object files.
4326 class Target_selector_i386_nacl
4327 : public Target_selector_nacl
<Target_selector_i386
, Target_i386_nacl
>
4330 Target_selector_i386_nacl()
4331 : Target_selector_nacl
<Target_selector_i386
,
4332 Target_i386_nacl
>("x86-32",
4338 Target_selector_i386_nacl target_selector_i386
;
4340 // IAMCU variant. It uses EM_IAMCU, not EM_386.
4342 class Target_iamcu
: public Target_i386
4346 : Target_i386(&iamcu_info
)
4350 // Information about this specific target which we pass to the
4351 // general Target structure.
4352 static const Target::Target_info iamcu_info
;
4355 const Target::Target_info
Target_iamcu::iamcu_info
=
4358 false, // is_big_endian
4359 elfcpp::EM_IAMCU
, // machine_code
4360 false, // has_make_symbol
4361 false, // has_resolve
4362 true, // has_code_fill
4363 true, // is_default_stack_executable
4364 true, // can_icf_inline_merge_sections
4366 "/usr/lib/libc.so.1", // dynamic_linker
4367 0x08048000, // default_text_segment_address
4368 0x1000, // abi_pagesize (overridable by -z max-page-size)
4369 0x1000, // common_pagesize (overridable by -z common-page-size)
4370 false, // isolate_execinstr
4372 elfcpp::SHN_UNDEF
, // small_common_shndx
4373 elfcpp::SHN_UNDEF
, // large_common_shndx
4374 0, // small_common_section_flags
4375 0, // large_common_section_flags
4376 NULL
, // attributes_section
4377 NULL
, // attributes_vendor
4378 "_start", // entry_symbol_name
4379 32, // hash_entry_size
4382 class Target_selector_iamcu
: public Target_selector
4385 Target_selector_iamcu()
4386 : Target_selector(elfcpp::EM_IAMCU
, 32, false, "elf32-iamcu",
4391 do_instantiate_target()
4392 { return new Target_iamcu(); }
4395 Target_selector_iamcu target_selector_iamcu
;
4397 } // End anonymous namespace.