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[binutils-gdb.git] / gold / x86_64.cc
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1 // x86_64.cc -- x86_64 target support for gold.
3 // Copyright (C) 2006-2017 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.
23 #include "gold.h"
25 #include <cstring>
27 #include "elfcpp.h"
28 #include "dwarf.h"
29 #include "parameters.h"
30 #include "reloc.h"
31 #include "x86_64.h"
32 #include "object.h"
33 #include "symtab.h"
34 #include "layout.h"
35 #include "output.h"
36 #include "copy-relocs.h"
37 #include "target.h"
38 #include "target-reloc.h"
39 #include "target-select.h"
40 #include "tls.h"
41 #include "freebsd.h"
42 #include "nacl.h"
43 #include "gc.h"
44 #include "icf.h"
46 namespace
49 using namespace gold;
51 // A class to handle the .got.plt section.
53 class Output_data_got_plt_x86_64 : public Output_section_data_build
55 public:
56 Output_data_got_plt_x86_64(Layout* layout)
57 : Output_section_data_build(8),
58 layout_(layout)
59 { }
61 Output_data_got_plt_x86_64(Layout* layout, off_t data_size)
62 : Output_section_data_build(data_size, 8),
63 layout_(layout)
64 { }
66 protected:
67 // Write out the PLT data.
68 void
69 do_write(Output_file*);
71 // Write to a map file.
72 void
73 do_print_to_mapfile(Mapfile* mapfile) const
74 { mapfile->print_output_data(this, "** GOT PLT"); }
76 private:
77 // A pointer to the Layout class, so that we can find the .dynamic
78 // section when we write out the GOT PLT section.
79 Layout* layout_;
82 // A class to handle the PLT data.
83 // This is an abstract base class that handles most of the linker details
84 // but does not know the actual contents of PLT entries. The derived
85 // classes below fill in those details.
87 template<int size>
88 class Output_data_plt_x86_64 : public Output_section_data
90 public:
91 typedef Output_data_reloc<elfcpp::SHT_RELA, true, size, false> Reloc_section;
93 Output_data_plt_x86_64(Layout* layout, uint64_t addralign,
94 Output_data_got<64, false>* got,
95 Output_data_got_plt_x86_64* got_plt,
96 Output_data_space* got_irelative)
97 : Output_section_data(addralign), tlsdesc_rel_(NULL),
98 irelative_rel_(NULL), got_(got), got_plt_(got_plt),
99 got_irelative_(got_irelative), count_(0), irelative_count_(0),
100 tlsdesc_got_offset_(-1U), free_list_()
101 { this->init(layout); }
103 Output_data_plt_x86_64(Layout* layout, uint64_t plt_entry_size,
104 Output_data_got<64, false>* got,
105 Output_data_got_plt_x86_64* got_plt,
106 Output_data_space* got_irelative,
107 unsigned int plt_count)
108 : Output_section_data((plt_count + 1) * plt_entry_size,
109 plt_entry_size, false),
110 tlsdesc_rel_(NULL), irelative_rel_(NULL), got_(got),
111 got_plt_(got_plt), got_irelative_(got_irelative), count_(plt_count),
112 irelative_count_(0), tlsdesc_got_offset_(-1U), free_list_()
114 this->init(layout);
116 // Initialize the free list and reserve the first entry.
117 this->free_list_.init((plt_count + 1) * plt_entry_size, false);
118 this->free_list_.remove(0, plt_entry_size);
121 // Initialize the PLT section.
122 void
123 init(Layout* layout);
125 // Add an entry to the PLT.
126 void
127 add_entry(Symbol_table*, Layout*, Symbol* gsym);
129 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
130 unsigned int
131 add_local_ifunc_entry(Symbol_table* symtab, Layout*,
132 Sized_relobj_file<size, false>* relobj,
133 unsigned int local_sym_index);
135 // Add the relocation for a PLT entry.
136 void
137 add_relocation(Symbol_table*, Layout*, Symbol* gsym,
138 unsigned int got_offset);
140 // Add the reserved TLSDESC_PLT entry to the PLT.
141 void
142 reserve_tlsdesc_entry(unsigned int got_offset)
143 { this->tlsdesc_got_offset_ = got_offset; }
145 // Return true if a TLSDESC_PLT entry has been reserved.
146 bool
147 has_tlsdesc_entry() const
148 { return this->tlsdesc_got_offset_ != -1U; }
150 // Return the GOT offset for the reserved TLSDESC_PLT entry.
151 unsigned int
152 get_tlsdesc_got_offset() const
153 { return this->tlsdesc_got_offset_; }
155 // Return the offset of the reserved TLSDESC_PLT entry.
156 unsigned int
157 get_tlsdesc_plt_offset() const
159 return ((this->count_ + this->irelative_count_ + 1)
160 * this->get_plt_entry_size());
163 // Return the .rela.plt section data.
164 Reloc_section*
165 rela_plt()
166 { return this->rel_; }
168 // Return where the TLSDESC relocations should go.
169 Reloc_section*
170 rela_tlsdesc(Layout*);
172 // Return where the IRELATIVE relocations should go in the PLT
173 // relocations.
174 Reloc_section*
175 rela_irelative(Symbol_table*, Layout*);
177 // Return whether we created a section for IRELATIVE relocations.
178 bool
179 has_irelative_section() const
180 { return this->irelative_rel_ != NULL; }
182 // Get count of regular PLT entries.
183 unsigned int
184 regular_count() const
185 { return this->count_; }
187 // Return the total number of PLT entries.
188 unsigned int
189 entry_count() const
190 { return this->count_ + this->irelative_count_; }
192 // Return the offset of the first non-reserved PLT entry.
193 unsigned int
194 first_plt_entry_offset()
195 { return this->get_plt_entry_size(); }
197 // Return the size of a PLT entry.
198 unsigned int
199 get_plt_entry_size() const
200 { return this->do_get_plt_entry_size(); }
202 // Reserve a slot in the PLT for an existing symbol in an incremental update.
203 void
204 reserve_slot(unsigned int plt_index)
206 this->free_list_.remove((plt_index + 1) * this->get_plt_entry_size(),
207 (plt_index + 2) * this->get_plt_entry_size());
210 // Return the PLT address to use for a global symbol.
211 uint64_t
212 address_for_global(const Symbol* sym)
213 { return do_address_for_global(sym); }
215 // Return the PLT address to use for a local symbol.
216 uint64_t
217 address_for_local(const Relobj* obj, unsigned int symndx)
218 { return do_address_for_local(obj, symndx); }
220 // Add .eh_frame information for the PLT.
221 void
222 add_eh_frame(Layout* layout)
223 { this->do_add_eh_frame(layout); }
225 protected:
226 Output_data_got<64, false>*
227 got() const
228 { return this->got_; }
230 Output_data_got_plt_x86_64*
231 got_plt() const
232 { return this->got_plt_; }
234 Output_data_space*
235 got_irelative() const
236 { return this->got_irelative_; }
238 // Fill in the first PLT entry.
239 void
240 fill_first_plt_entry(unsigned char* pov,
241 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
242 typename elfcpp::Elf_types<size>::Elf_Addr plt_address)
243 { this->do_fill_first_plt_entry(pov, got_address, plt_address); }
245 // Fill in a normal PLT entry. Returns the offset into the entry that
246 // should be the initial GOT slot value.
247 unsigned int
248 fill_plt_entry(unsigned char* pov,
249 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
250 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
251 unsigned int got_offset,
252 unsigned int plt_offset,
253 unsigned int plt_index)
255 return this->do_fill_plt_entry(pov, got_address, plt_address,
256 got_offset, plt_offset, plt_index);
259 // Fill in the reserved TLSDESC PLT entry.
260 void
261 fill_tlsdesc_entry(unsigned char* pov,
262 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
263 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
264 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
265 unsigned int tlsdesc_got_offset,
266 unsigned int plt_offset)
268 this->do_fill_tlsdesc_entry(pov, got_address, plt_address, got_base,
269 tlsdesc_got_offset, plt_offset);
272 virtual unsigned int
273 do_get_plt_entry_size() const = 0;
275 virtual void
276 do_fill_first_plt_entry(unsigned char* pov,
277 typename elfcpp::Elf_types<size>::Elf_Addr got_addr,
278 typename elfcpp::Elf_types<size>::Elf_Addr plt_addr)
279 = 0;
281 virtual unsigned int
282 do_fill_plt_entry(unsigned char* pov,
283 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
284 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
285 unsigned int got_offset,
286 unsigned int plt_offset,
287 unsigned int plt_index) = 0;
289 virtual void
290 do_fill_tlsdesc_entry(unsigned char* pov,
291 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
292 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
293 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
294 unsigned int tlsdesc_got_offset,
295 unsigned int plt_offset) = 0;
297 // Return the PLT address to use for a global symbol.
298 virtual uint64_t
299 do_address_for_global(const Symbol* sym);
301 // Return the PLT address to use for a local symbol.
302 virtual uint64_t
303 do_address_for_local(const Relobj* obj, unsigned int symndx);
305 virtual void
306 do_add_eh_frame(Layout* layout) = 0;
308 void
309 do_adjust_output_section(Output_section* os);
311 // Write to a map file.
312 void
313 do_print_to_mapfile(Mapfile* mapfile) const
314 { mapfile->print_output_data(this, _("** PLT")); }
316 // The CIE of the .eh_frame unwind information for the PLT.
317 static const int plt_eh_frame_cie_size = 16;
318 static const unsigned char plt_eh_frame_cie[plt_eh_frame_cie_size];
320 private:
321 // Set the final size.
322 void
323 set_final_data_size();
325 // Write out the PLT data.
326 void
327 do_write(Output_file*);
329 // The reloc section.
330 Reloc_section* rel_;
331 // The TLSDESC relocs, if necessary. These must follow the regular
332 // PLT relocs.
333 Reloc_section* tlsdesc_rel_;
334 // The IRELATIVE relocs, if necessary. These must follow the
335 // regular PLT relocations and the TLSDESC relocations.
336 Reloc_section* irelative_rel_;
337 // The .got section.
338 Output_data_got<64, false>* got_;
339 // The .got.plt section.
340 Output_data_got_plt_x86_64* got_plt_;
341 // The part of the .got.plt section used for IRELATIVE relocs.
342 Output_data_space* got_irelative_;
343 // The number of PLT entries.
344 unsigned int count_;
345 // Number of PLT entries with R_X86_64_IRELATIVE relocs. These
346 // follow the regular PLT entries.
347 unsigned int irelative_count_;
348 // Offset of the reserved TLSDESC_GOT entry when needed.
349 unsigned int tlsdesc_got_offset_;
350 // List of available regions within the section, for incremental
351 // update links.
352 Free_list free_list_;
355 template<int size>
356 class Output_data_plt_x86_64_standard : public Output_data_plt_x86_64<size>
358 public:
359 Output_data_plt_x86_64_standard(Layout* layout,
360 Output_data_got<64, false>* got,
361 Output_data_got_plt_x86_64* got_plt,
362 Output_data_space* got_irelative)
363 : Output_data_plt_x86_64<size>(layout, plt_entry_size,
364 got, got_plt, got_irelative)
367 Output_data_plt_x86_64_standard(Layout* layout,
368 Output_data_got<64, false>* got,
369 Output_data_got_plt_x86_64* got_plt,
370 Output_data_space* got_irelative,
371 unsigned int plt_count)
372 : Output_data_plt_x86_64<size>(layout, plt_entry_size,
373 got, got_plt, got_irelative,
374 plt_count)
377 protected:
378 virtual unsigned int
379 do_get_plt_entry_size() const
380 { return plt_entry_size; }
382 virtual void
383 do_add_eh_frame(Layout* layout)
385 layout->add_eh_frame_for_plt(this,
386 this->plt_eh_frame_cie,
387 this->plt_eh_frame_cie_size,
388 plt_eh_frame_fde,
389 plt_eh_frame_fde_size);
392 virtual void
393 do_fill_first_plt_entry(unsigned char* pov,
394 typename elfcpp::Elf_types<size>::Elf_Addr got_addr,
395 typename elfcpp::Elf_types<size>::Elf_Addr plt_addr);
397 virtual unsigned int
398 do_fill_plt_entry(unsigned char* pov,
399 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
400 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
401 unsigned int got_offset,
402 unsigned int plt_offset,
403 unsigned int plt_index);
405 virtual void
406 do_fill_tlsdesc_entry(unsigned char* pov,
407 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
408 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
409 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
410 unsigned int tlsdesc_got_offset,
411 unsigned int plt_offset);
413 private:
414 // The size of an entry in the PLT.
415 static const int plt_entry_size = 16;
417 // The first entry in the PLT.
418 // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
419 // procedure linkage table for both programs and shared objects."
420 static const unsigned char first_plt_entry[plt_entry_size];
422 // Other entries in the PLT for an executable.
423 static const unsigned char plt_entry[plt_entry_size];
425 // The reserved TLSDESC entry in the PLT for an executable.
426 static const unsigned char tlsdesc_plt_entry[plt_entry_size];
428 // The .eh_frame unwind information for the PLT.
429 static const int plt_eh_frame_fde_size = 32;
430 static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
433 class Output_data_plt_x86_64_bnd : public Output_data_plt_x86_64<64>
435 public:
436 Output_data_plt_x86_64_bnd(Layout* layout,
437 Output_data_got<64, false>* got,
438 Output_data_got_plt_x86_64* got_plt,
439 Output_data_space* got_irelative)
440 : Output_data_plt_x86_64<64>(layout, plt_entry_size,
441 got, got_plt, got_irelative),
442 aplt_offset_(0)
445 Output_data_plt_x86_64_bnd(Layout* layout,
446 Output_data_got<64, false>* got,
447 Output_data_got_plt_x86_64* got_plt,
448 Output_data_space* got_irelative,
449 unsigned int plt_count)
450 : Output_data_plt_x86_64<64>(layout, plt_entry_size,
451 got, got_plt, got_irelative,
452 plt_count),
453 aplt_offset_(0)
456 protected:
457 virtual unsigned int
458 do_get_plt_entry_size() const
459 { return plt_entry_size; }
461 // Return the PLT address to use for a global symbol.
462 uint64_t
463 do_address_for_global(const Symbol*);
465 // Return the PLT address to use for a local symbol.
466 uint64_t
467 do_address_for_local(const Relobj*, unsigned int symndx);
469 virtual void
470 do_add_eh_frame(Layout* layout)
472 layout->add_eh_frame_for_plt(this,
473 this->plt_eh_frame_cie,
474 this->plt_eh_frame_cie_size,
475 plt_eh_frame_fde,
476 plt_eh_frame_fde_size);
479 virtual void
480 do_fill_first_plt_entry(unsigned char* pov,
481 elfcpp::Elf_types<64>::Elf_Addr got_addr,
482 elfcpp::Elf_types<64>::Elf_Addr plt_addr);
484 virtual unsigned int
485 do_fill_plt_entry(unsigned char* pov,
486 elfcpp::Elf_types<64>::Elf_Addr got_address,
487 elfcpp::Elf_types<64>::Elf_Addr plt_address,
488 unsigned int got_offset,
489 unsigned int plt_offset,
490 unsigned int plt_index);
492 virtual void
493 do_fill_tlsdesc_entry(unsigned char* pov,
494 elfcpp::Elf_types<64>::Elf_Addr got_address,
495 elfcpp::Elf_types<64>::Elf_Addr plt_address,
496 elfcpp::Elf_types<64>::Elf_Addr got_base,
497 unsigned int tlsdesc_got_offset,
498 unsigned int plt_offset);
500 void
501 fill_aplt_entry(unsigned char* pov,
502 elfcpp::Elf_types<64>::Elf_Addr got_address,
503 elfcpp::Elf_types<64>::Elf_Addr plt_address,
504 unsigned int got_offset,
505 unsigned int plt_offset,
506 unsigned int plt_index);
508 private:
509 // Set the final size.
510 void
511 set_final_data_size();
513 // Write out the BND PLT data.
514 void
515 do_write(Output_file*);
517 // Offset of the Additional PLT (if using -z bndplt).
518 unsigned int aplt_offset_;
520 // The size of an entry in the PLT.
521 static const int plt_entry_size = 16;
523 // The size of an entry in the additional PLT.
524 static const int aplt_entry_size = 8;
526 // The first entry in the PLT.
527 // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
528 // procedure linkage table for both programs and shared objects."
529 static const unsigned char first_plt_entry[plt_entry_size];
531 // Other entries in the PLT for an executable.
532 static const unsigned char plt_entry[plt_entry_size];
534 // Entries in the additional PLT.
535 static const unsigned char aplt_entry[aplt_entry_size];
537 // The reserved TLSDESC entry in the PLT for an executable.
538 static const unsigned char tlsdesc_plt_entry[plt_entry_size];
540 // The .eh_frame unwind information for the PLT.
541 static const int plt_eh_frame_fde_size = 32;
542 static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
545 template<int size>
546 class Lazy_view
548 public:
549 Lazy_view(Sized_relobj_file<size, false>* object, unsigned int data_shndx)
550 : object_(object), data_shndx_(data_shndx), view_(NULL), view_size_(0)
553 inline unsigned char
554 operator[](size_t offset)
556 if (this->view_ == NULL)
557 this->view_ = this->object_->section_contents(this->data_shndx_,
558 &this->view_size_,
559 true);
560 if (offset >= this->view_size_)
561 return 0;
562 return this->view_[offset];
565 private:
566 Sized_relobj_file<size, false>* object_;
567 unsigned int data_shndx_;
568 const unsigned char* view_;
569 section_size_type view_size_;
572 // The x86_64 target class.
573 // See the ABI at
574 // http://www.x86-64.org/documentation/abi.pdf
575 // TLS info comes from
576 // http://people.redhat.com/drepper/tls.pdf
577 // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
579 template<int size>
580 class Target_x86_64 : public Sized_target<size, false>
582 public:
583 // In the x86_64 ABI (p 68), it says "The AMD64 ABI architectures
584 // uses only Elf64_Rela relocation entries with explicit addends."
585 typedef Output_data_reloc<elfcpp::SHT_RELA, true, size, false> Reloc_section;
587 Target_x86_64(const Target::Target_info* info = &x86_64_info)
588 : Sized_target<size, false>(info),
589 got_(NULL), plt_(NULL), got_plt_(NULL), got_irelative_(NULL),
590 got_tlsdesc_(NULL), global_offset_table_(NULL), rela_dyn_(NULL),
591 rela_irelative_(NULL), copy_relocs_(elfcpp::R_X86_64_COPY),
592 got_mod_index_offset_(-1U), tlsdesc_reloc_info_(),
593 tls_base_symbol_defined_(false)
596 // Hook for a new output section.
597 void
598 do_new_output_section(Output_section*) const;
600 // Scan the relocations to look for symbol adjustments.
601 void
602 gc_process_relocs(Symbol_table* symtab,
603 Layout* layout,
604 Sized_relobj_file<size, false>* object,
605 unsigned int data_shndx,
606 unsigned int sh_type,
607 const unsigned char* prelocs,
608 size_t reloc_count,
609 Output_section* output_section,
610 bool needs_special_offset_handling,
611 size_t local_symbol_count,
612 const unsigned char* plocal_symbols);
614 // Scan the relocations to look for symbol adjustments.
615 void
616 scan_relocs(Symbol_table* symtab,
617 Layout* layout,
618 Sized_relobj_file<size, false>* object,
619 unsigned int data_shndx,
620 unsigned int sh_type,
621 const unsigned char* prelocs,
622 size_t reloc_count,
623 Output_section* output_section,
624 bool needs_special_offset_handling,
625 size_t local_symbol_count,
626 const unsigned char* plocal_symbols);
628 // Finalize the sections.
629 void
630 do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
632 // Return the value to use for a dynamic which requires special
633 // treatment.
634 uint64_t
635 do_dynsym_value(const Symbol*) const;
637 // Relocate a section.
638 void
639 relocate_section(const Relocate_info<size, false>*,
640 unsigned int sh_type,
641 const unsigned char* prelocs,
642 size_t reloc_count,
643 Output_section* output_section,
644 bool needs_special_offset_handling,
645 unsigned char* view,
646 typename elfcpp::Elf_types<size>::Elf_Addr view_address,
647 section_size_type view_size,
648 const Reloc_symbol_changes*);
650 // Scan the relocs during a relocatable link.
651 void
652 scan_relocatable_relocs(Symbol_table* symtab,
653 Layout* layout,
654 Sized_relobj_file<size, false>* object,
655 unsigned int data_shndx,
656 unsigned int sh_type,
657 const unsigned char* prelocs,
658 size_t reloc_count,
659 Output_section* output_section,
660 bool needs_special_offset_handling,
661 size_t local_symbol_count,
662 const unsigned char* plocal_symbols,
663 Relocatable_relocs*);
665 // Scan the relocs for --emit-relocs.
666 void
667 emit_relocs_scan(Symbol_table* symtab,
668 Layout* layout,
669 Sized_relobj_file<size, false>* object,
670 unsigned int data_shndx,
671 unsigned int sh_type,
672 const unsigned char* prelocs,
673 size_t reloc_count,
674 Output_section* output_section,
675 bool needs_special_offset_handling,
676 size_t local_symbol_count,
677 const unsigned char* plocal_syms,
678 Relocatable_relocs* rr);
680 // Emit relocations for a section.
681 void
682 relocate_relocs(
683 const Relocate_info<size, false>*,
684 unsigned int sh_type,
685 const unsigned char* prelocs,
686 size_t reloc_count,
687 Output_section* output_section,
688 typename elfcpp::Elf_types<size>::Elf_Off offset_in_output_section,
689 unsigned char* view,
690 typename elfcpp::Elf_types<size>::Elf_Addr view_address,
691 section_size_type view_size,
692 unsigned char* reloc_view,
693 section_size_type reloc_view_size);
695 // Return a string used to fill a code section with nops.
696 std::string
697 do_code_fill(section_size_type length) const;
699 // Return whether SYM is defined by the ABI.
700 bool
701 do_is_defined_by_abi(const Symbol* sym) const
702 { return strcmp(sym->name(), "__tls_get_addr") == 0; }
704 // Return the symbol index to use for a target specific relocation.
705 // The only target specific relocation is R_X86_64_TLSDESC for a
706 // local symbol, which is an absolute reloc.
707 unsigned int
708 do_reloc_symbol_index(void*, unsigned int r_type) const
710 gold_assert(r_type == elfcpp::R_X86_64_TLSDESC);
711 return 0;
714 // Return the addend to use for a target specific relocation.
715 uint64_t
716 do_reloc_addend(void* arg, unsigned int r_type, uint64_t addend) const;
718 // Return the PLT section.
719 uint64_t
720 do_plt_address_for_global(const Symbol* gsym) const
721 { return this->plt_section()->address_for_global(gsym); }
723 uint64_t
724 do_plt_address_for_local(const Relobj* relobj, unsigned int symndx) const
725 { return this->plt_section()->address_for_local(relobj, symndx); }
727 // This function should be defined in targets that can use relocation
728 // types to determine (implemented in local_reloc_may_be_function_pointer
729 // and global_reloc_may_be_function_pointer)
730 // if a function's pointer is taken. ICF uses this in safe mode to only
731 // fold those functions whose pointer is defintely not taken. For x86_64
732 // pie binaries, safe ICF cannot be done by looking at only relocation
733 // types, and for certain cases (e.g. R_X86_64_PC32), the instruction
734 // opcode is checked as well to distinguish a function call from taking
735 // a function's pointer.
736 bool
737 do_can_check_for_function_pointers() const
738 { return true; }
740 // Return the base for a DW_EH_PE_datarel encoding.
741 uint64_t
742 do_ehframe_datarel_base() const;
744 // Adjust -fsplit-stack code which calls non-split-stack code.
745 void
746 do_calls_non_split(Relobj* object, unsigned int shndx,
747 section_offset_type fnoffset, section_size_type fnsize,
748 const unsigned char* prelocs, size_t reloc_count,
749 unsigned char* view, section_size_type view_size,
750 std::string* from, std::string* to) const;
752 // Return the size of the GOT section.
753 section_size_type
754 got_size() const
756 gold_assert(this->got_ != NULL);
757 return this->got_->data_size();
760 // Return the number of entries in the GOT.
761 unsigned int
762 got_entry_count() const
764 if (this->got_ == NULL)
765 return 0;
766 return this->got_size() / 8;
769 // Return the number of entries in the PLT.
770 unsigned int
771 plt_entry_count() const;
773 // Return the offset of the first non-reserved PLT entry.
774 unsigned int
775 first_plt_entry_offset() const;
777 // Return the size of each PLT entry.
778 unsigned int
779 plt_entry_size() const;
781 // Return the size of each GOT entry.
782 unsigned int
783 got_entry_size() const
784 { return 8; };
786 // Create the GOT section for an incremental update.
787 Output_data_got_base*
788 init_got_plt_for_update(Symbol_table* symtab,
789 Layout* layout,
790 unsigned int got_count,
791 unsigned int plt_count);
793 // Reserve a GOT entry for a local symbol, and regenerate any
794 // necessary dynamic relocations.
795 void
796 reserve_local_got_entry(unsigned int got_index,
797 Sized_relobj<size, false>* obj,
798 unsigned int r_sym,
799 unsigned int got_type);
801 // Reserve a GOT entry for a global symbol, and regenerate any
802 // necessary dynamic relocations.
803 void
804 reserve_global_got_entry(unsigned int got_index, Symbol* gsym,
805 unsigned int got_type);
807 // Register an existing PLT entry for a global symbol.
808 void
809 register_global_plt_entry(Symbol_table*, Layout*, unsigned int plt_index,
810 Symbol* gsym);
812 // Force a COPY relocation for a given symbol.
813 void
814 emit_copy_reloc(Symbol_table*, Symbol*, Output_section*, off_t);
816 // Apply an incremental relocation.
817 void
818 apply_relocation(const Relocate_info<size, false>* relinfo,
819 typename elfcpp::Elf_types<size>::Elf_Addr r_offset,
820 unsigned int r_type,
821 typename elfcpp::Elf_types<size>::Elf_Swxword r_addend,
822 const Symbol* gsym,
823 unsigned char* view,
824 typename elfcpp::Elf_types<size>::Elf_Addr address,
825 section_size_type view_size);
827 // Add a new reloc argument, returning the index in the vector.
828 size_t
829 add_tlsdesc_info(Sized_relobj_file<size, false>* object, unsigned int r_sym)
831 this->tlsdesc_reloc_info_.push_back(Tlsdesc_info(object, r_sym));
832 return this->tlsdesc_reloc_info_.size() - 1;
835 Output_data_plt_x86_64<size>*
836 make_data_plt(Layout* layout,
837 Output_data_got<64, false>* got,
838 Output_data_got_plt_x86_64* got_plt,
839 Output_data_space* got_irelative)
841 return this->do_make_data_plt(layout, got, got_plt, got_irelative);
844 Output_data_plt_x86_64<size>*
845 make_data_plt(Layout* layout,
846 Output_data_got<64, false>* got,
847 Output_data_got_plt_x86_64* got_plt,
848 Output_data_space* got_irelative,
849 unsigned int plt_count)
851 return this->do_make_data_plt(layout, got, got_plt, got_irelative,
852 plt_count);
855 virtual Output_data_plt_x86_64<size>*
856 do_make_data_plt(Layout* layout,
857 Output_data_got<64, false>* got,
858 Output_data_got_plt_x86_64* got_plt,
859 Output_data_space* got_irelative);
861 virtual Output_data_plt_x86_64<size>*
862 do_make_data_plt(Layout* layout,
863 Output_data_got<64, false>* got,
864 Output_data_got_plt_x86_64* got_plt,
865 Output_data_space* got_irelative,
866 unsigned int plt_count);
868 private:
869 // The class which scans relocations.
870 class Scan
872 public:
873 Scan()
874 : issued_non_pic_error_(false)
877 static inline int
878 get_reference_flags(unsigned int r_type);
880 inline void
881 local(Symbol_table* symtab, Layout* layout, Target_x86_64* target,
882 Sized_relobj_file<size, false>* object,
883 unsigned int data_shndx,
884 Output_section* output_section,
885 const elfcpp::Rela<size, false>& reloc, unsigned int r_type,
886 const elfcpp::Sym<size, false>& lsym,
887 bool is_discarded);
889 inline void
890 global(Symbol_table* symtab, Layout* layout, Target_x86_64* target,
891 Sized_relobj_file<size, false>* object,
892 unsigned int data_shndx,
893 Output_section* output_section,
894 const elfcpp::Rela<size, false>& reloc, unsigned int r_type,
895 Symbol* gsym);
897 inline bool
898 local_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
899 Target_x86_64* target,
900 Sized_relobj_file<size, false>* object,
901 unsigned int data_shndx,
902 Output_section* output_section,
903 const elfcpp::Rela<size, false>& reloc,
904 unsigned int r_type,
905 const elfcpp::Sym<size, false>& lsym);
907 inline bool
908 global_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
909 Target_x86_64* target,
910 Sized_relobj_file<size, false>* object,
911 unsigned int data_shndx,
912 Output_section* output_section,
913 const elfcpp::Rela<size, false>& reloc,
914 unsigned int r_type,
915 Symbol* gsym);
917 private:
918 static void
919 unsupported_reloc_local(Sized_relobj_file<size, false>*,
920 unsigned int r_type);
922 static void
923 unsupported_reloc_global(Sized_relobj_file<size, false>*,
924 unsigned int r_type, Symbol*);
926 void
927 check_non_pic(Relobj*, unsigned int r_type, Symbol*);
929 inline bool
930 possible_function_pointer_reloc(Sized_relobj_file<size, false>* src_obj,
931 unsigned int src_indx,
932 unsigned int r_offset,
933 unsigned int r_type);
935 bool
936 reloc_needs_plt_for_ifunc(Sized_relobj_file<size, false>*,
937 unsigned int r_type);
939 // Whether we have issued an error about a non-PIC compilation.
940 bool issued_non_pic_error_;
943 // The class which implements relocation.
944 class Relocate
946 public:
947 Relocate()
948 : skip_call_tls_get_addr_(false)
951 ~Relocate()
953 if (this->skip_call_tls_get_addr_)
955 // FIXME: This needs to specify the location somehow.
956 gold_error(_("missing expected TLS relocation"));
960 // Do a relocation. Return false if the caller should not issue
961 // any warnings about this relocation.
962 inline bool
963 relocate(const Relocate_info<size, false>*, unsigned int,
964 Target_x86_64*, Output_section*, size_t, const unsigned char*,
965 const Sized_symbol<size>*, const Symbol_value<size>*,
966 unsigned char*, typename elfcpp::Elf_types<size>::Elf_Addr,
967 section_size_type);
969 private:
970 // Do a TLS relocation.
971 inline void
972 relocate_tls(const Relocate_info<size, false>*, Target_x86_64*,
973 size_t relnum, const elfcpp::Rela<size, false>&,
974 unsigned int r_type, const Sized_symbol<size>*,
975 const Symbol_value<size>*,
976 unsigned char*, typename elfcpp::Elf_types<size>::Elf_Addr,
977 section_size_type);
979 // Do a TLS General-Dynamic to Initial-Exec transition.
980 inline void
981 tls_gd_to_ie(const Relocate_info<size, false>*, size_t relnum,
982 const elfcpp::Rela<size, false>&, unsigned int r_type,
983 typename elfcpp::Elf_types<size>::Elf_Addr value,
984 unsigned char* view,
985 typename elfcpp::Elf_types<size>::Elf_Addr,
986 section_size_type view_size);
988 // Do a TLS General-Dynamic to Local-Exec transition.
989 inline void
990 tls_gd_to_le(const Relocate_info<size, false>*, size_t relnum,
991 Output_segment* tls_segment,
992 const elfcpp::Rela<size, false>&, unsigned int r_type,
993 typename elfcpp::Elf_types<size>::Elf_Addr value,
994 unsigned char* view,
995 section_size_type view_size);
997 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
998 inline void
999 tls_desc_gd_to_ie(const Relocate_info<size, false>*, size_t relnum,
1000 const elfcpp::Rela<size, false>&, unsigned int r_type,
1001 typename elfcpp::Elf_types<size>::Elf_Addr value,
1002 unsigned char* view,
1003 typename elfcpp::Elf_types<size>::Elf_Addr,
1004 section_size_type view_size);
1006 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
1007 inline void
1008 tls_desc_gd_to_le(const Relocate_info<size, false>*, size_t relnum,
1009 Output_segment* tls_segment,
1010 const elfcpp::Rela<size, false>&, unsigned int r_type,
1011 typename elfcpp::Elf_types<size>::Elf_Addr value,
1012 unsigned char* view,
1013 section_size_type view_size);
1015 // Do a TLS Local-Dynamic to Local-Exec transition.
1016 inline void
1017 tls_ld_to_le(const Relocate_info<size, false>*, size_t relnum,
1018 Output_segment* tls_segment,
1019 const elfcpp::Rela<size, false>&, unsigned int r_type,
1020 typename elfcpp::Elf_types<size>::Elf_Addr value,
1021 unsigned char* view,
1022 section_size_type view_size);
1024 // Do a TLS Initial-Exec to Local-Exec transition.
1025 static inline void
1026 tls_ie_to_le(const Relocate_info<size, false>*, size_t relnum,
1027 Output_segment* tls_segment,
1028 const elfcpp::Rela<size, false>&, unsigned int r_type,
1029 typename elfcpp::Elf_types<size>::Elf_Addr value,
1030 unsigned char* view,
1031 section_size_type view_size);
1033 // This is set if we should skip the next reloc, which should be a
1034 // PLT32 reloc against ___tls_get_addr.
1035 bool skip_call_tls_get_addr_;
1038 // Check if relocation against this symbol is a candidate for
1039 // conversion from
1040 // mov foo@GOTPCREL(%rip), %reg
1041 // to lea foo(%rip), %reg.
1042 template<class View_type>
1043 static inline bool
1044 can_convert_mov_to_lea(const Symbol* gsym, unsigned int r_type,
1045 size_t r_offset, View_type* view)
1047 gold_assert(gsym != NULL);
1048 // We cannot do the conversion unless it's one of these relocations.
1049 if (r_type != elfcpp::R_X86_64_GOTPCREL
1050 && r_type != elfcpp::R_X86_64_GOTPCRELX
1051 && r_type != elfcpp::R_X86_64_REX_GOTPCRELX)
1052 return false;
1053 // We cannot convert references to IFUNC symbols, or to symbols that
1054 // are not local to the current module.
1055 // We can't do predefined symbols because they may become undefined
1056 // (e.g., __ehdr_start when the headers aren't mapped to a segment).
1057 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1058 || gsym->is_undefined()
1059 || gsym->is_predefined()
1060 || gsym->is_from_dynobj()
1061 || gsym->is_preemptible())
1062 return false;
1063 // If we are building a shared object and the symbol is protected, we may
1064 // need to go through the GOT.
1065 if (parameters->options().shared()
1066 && gsym->visibility() == elfcpp::STV_PROTECTED)
1067 return false;
1068 // We cannot convert references to the _DYNAMIC symbol.
1069 if (strcmp(gsym->name(), "_DYNAMIC") == 0)
1070 return false;
1071 // Check for a MOV opcode.
1072 return (*view)[r_offset - 2] == 0x8b;
1075 // Convert
1076 // callq *foo@GOTPCRELX(%rip) to
1077 // addr32 callq foo
1078 // and jmpq *foo@GOTPCRELX(%rip) to
1079 // jmpq foo
1080 // nop
1081 template<class View_type>
1082 static inline bool
1083 can_convert_callq_to_direct(const Symbol* gsym, unsigned int r_type,
1084 size_t r_offset, View_type* view)
1086 gold_assert(gsym != NULL);
1087 // We cannot do the conversion unless it's a GOTPCRELX relocation.
1088 if (r_type != elfcpp::R_X86_64_GOTPCRELX)
1089 return false;
1090 // We cannot convert references to IFUNC symbols, or to symbols that
1091 // are not local to the current module.
1092 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1093 || gsym->is_undefined ()
1094 || gsym->is_from_dynobj()
1095 || gsym->is_preemptible())
1096 return false;
1097 // Check for a CALLQ or JMPQ opcode.
1098 return ((*view)[r_offset - 2] == 0xff
1099 && ((*view)[r_offset - 1] == 0x15
1100 || (*view)[r_offset - 1] == 0x25));
1103 // Adjust TLS relocation type based on the options and whether this
1104 // is a local symbol.
1105 static tls::Tls_optimization
1106 optimize_tls_reloc(bool is_final, int r_type);
1108 // Get the GOT section, creating it if necessary.
1109 Output_data_got<64, false>*
1110 got_section(Symbol_table*, Layout*);
1112 // Get the GOT PLT section.
1113 Output_data_got_plt_x86_64*
1114 got_plt_section() const
1116 gold_assert(this->got_plt_ != NULL);
1117 return this->got_plt_;
1120 // Get the GOT section for TLSDESC entries.
1121 Output_data_got<64, false>*
1122 got_tlsdesc_section() const
1124 gold_assert(this->got_tlsdesc_ != NULL);
1125 return this->got_tlsdesc_;
1128 // Create the PLT section.
1129 void
1130 make_plt_section(Symbol_table* symtab, Layout* layout);
1132 // Create a PLT entry for a global symbol.
1133 void
1134 make_plt_entry(Symbol_table*, Layout*, Symbol*);
1136 // Create a PLT entry for a local STT_GNU_IFUNC symbol.
1137 void
1138 make_local_ifunc_plt_entry(Symbol_table*, Layout*,
1139 Sized_relobj_file<size, false>* relobj,
1140 unsigned int local_sym_index);
1142 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
1143 void
1144 define_tls_base_symbol(Symbol_table*, Layout*);
1146 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
1147 void
1148 reserve_tlsdesc_entries(Symbol_table* symtab, Layout* layout);
1150 // Create a GOT entry for the TLS module index.
1151 unsigned int
1152 got_mod_index_entry(Symbol_table* symtab, Layout* layout,
1153 Sized_relobj_file<size, false>* object);
1155 // Get the PLT section.
1156 Output_data_plt_x86_64<size>*
1157 plt_section() const
1159 gold_assert(this->plt_ != NULL);
1160 return this->plt_;
1163 // Get the dynamic reloc section, creating it if necessary.
1164 Reloc_section*
1165 rela_dyn_section(Layout*);
1167 // Get the section to use for TLSDESC relocations.
1168 Reloc_section*
1169 rela_tlsdesc_section(Layout*) const;
1171 // Get the section to use for IRELATIVE relocations.
1172 Reloc_section*
1173 rela_irelative_section(Layout*);
1175 // Add a potential copy relocation.
1176 void
1177 copy_reloc(Symbol_table* symtab, Layout* layout,
1178 Sized_relobj_file<size, false>* object,
1179 unsigned int shndx, Output_section* output_section,
1180 Symbol* sym, const elfcpp::Rela<size, false>& reloc)
1182 unsigned int r_type = elfcpp::elf_r_type<size>(reloc.get_r_info());
1183 this->copy_relocs_.copy_reloc(symtab, layout,
1184 symtab->get_sized_symbol<size>(sym),
1185 object, shndx, output_section,
1186 r_type, reloc.get_r_offset(),
1187 reloc.get_r_addend(),
1188 this->rela_dyn_section(layout));
1191 // Information about this specific target which we pass to the
1192 // general Target structure.
1193 static const Target::Target_info x86_64_info;
1195 // The types of GOT entries needed for this platform.
1196 // These values are exposed to the ABI in an incremental link.
1197 // Do not renumber existing values without changing the version
1198 // number of the .gnu_incremental_inputs section.
1199 enum Got_type
1201 GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
1202 GOT_TYPE_TLS_OFFSET = 1, // GOT entry for TLS offset
1203 GOT_TYPE_TLS_PAIR = 2, // GOT entry for TLS module/offset pair
1204 GOT_TYPE_TLS_DESC = 3 // GOT entry for TLS_DESC pair
1207 // This type is used as the argument to the target specific
1208 // relocation routines. The only target specific reloc is
1209 // R_X86_64_TLSDESC against a local symbol.
1210 struct Tlsdesc_info
1212 Tlsdesc_info(Sized_relobj_file<size, false>* a_object, unsigned int a_r_sym)
1213 : object(a_object), r_sym(a_r_sym)
1216 // The object in which the local symbol is defined.
1217 Sized_relobj_file<size, false>* object;
1218 // The local symbol index in the object.
1219 unsigned int r_sym;
1222 // The GOT section.
1223 Output_data_got<64, false>* got_;
1224 // The PLT section.
1225 Output_data_plt_x86_64<size>* plt_;
1226 // The GOT PLT section.
1227 Output_data_got_plt_x86_64* got_plt_;
1228 // The GOT section for IRELATIVE relocations.
1229 Output_data_space* got_irelative_;
1230 // The GOT section for TLSDESC relocations.
1231 Output_data_got<64, false>* got_tlsdesc_;
1232 // The _GLOBAL_OFFSET_TABLE_ symbol.
1233 Symbol* global_offset_table_;
1234 // The dynamic reloc section.
1235 Reloc_section* rela_dyn_;
1236 // The section to use for IRELATIVE relocs.
1237 Reloc_section* rela_irelative_;
1238 // Relocs saved to avoid a COPY reloc.
1239 Copy_relocs<elfcpp::SHT_RELA, size, false> copy_relocs_;
1240 // Offset of the GOT entry for the TLS module index.
1241 unsigned int got_mod_index_offset_;
1242 // We handle R_X86_64_TLSDESC against a local symbol as a target
1243 // specific relocation. Here we store the object and local symbol
1244 // index for the relocation.
1245 std::vector<Tlsdesc_info> tlsdesc_reloc_info_;
1246 // True if the _TLS_MODULE_BASE_ symbol has been defined.
1247 bool tls_base_symbol_defined_;
1250 template<>
1251 const Target::Target_info Target_x86_64<64>::x86_64_info =
1253 64, // size
1254 false, // is_big_endian
1255 elfcpp::EM_X86_64, // machine_code
1256 false, // has_make_symbol
1257 false, // has_resolve
1258 true, // has_code_fill
1259 true, // is_default_stack_executable
1260 true, // can_icf_inline_merge_sections
1261 '\0', // wrap_char
1262 "/lib/ld64.so.1", // program interpreter
1263 0x400000, // default_text_segment_address
1264 0x1000, // abi_pagesize (overridable by -z max-page-size)
1265 0x1000, // common_pagesize (overridable by -z common-page-size)
1266 false, // isolate_execinstr
1267 0, // rosegment_gap
1268 elfcpp::SHN_UNDEF, // small_common_shndx
1269 elfcpp::SHN_X86_64_LCOMMON, // large_common_shndx
1270 0, // small_common_section_flags
1271 elfcpp::SHF_X86_64_LARGE, // large_common_section_flags
1272 NULL, // attributes_section
1273 NULL, // attributes_vendor
1274 "_start", // entry_symbol_name
1275 32, // hash_entry_size
1278 template<>
1279 const Target::Target_info Target_x86_64<32>::x86_64_info =
1281 32, // size
1282 false, // is_big_endian
1283 elfcpp::EM_X86_64, // machine_code
1284 false, // has_make_symbol
1285 false, // has_resolve
1286 true, // has_code_fill
1287 true, // is_default_stack_executable
1288 true, // can_icf_inline_merge_sections
1289 '\0', // wrap_char
1290 "/libx32/ldx32.so.1", // program interpreter
1291 0x400000, // default_text_segment_address
1292 0x1000, // abi_pagesize (overridable by -z max-page-size)
1293 0x1000, // common_pagesize (overridable by -z common-page-size)
1294 false, // isolate_execinstr
1295 0, // rosegment_gap
1296 elfcpp::SHN_UNDEF, // small_common_shndx
1297 elfcpp::SHN_X86_64_LCOMMON, // large_common_shndx
1298 0, // small_common_section_flags
1299 elfcpp::SHF_X86_64_LARGE, // large_common_section_flags
1300 NULL, // attributes_section
1301 NULL, // attributes_vendor
1302 "_start", // entry_symbol_name
1303 32, // hash_entry_size
1306 // This is called when a new output section is created. This is where
1307 // we handle the SHF_X86_64_LARGE.
1309 template<int size>
1310 void
1311 Target_x86_64<size>::do_new_output_section(Output_section* os) const
1313 if ((os->flags() & elfcpp::SHF_X86_64_LARGE) != 0)
1314 os->set_is_large_section();
1317 // Get the GOT section, creating it if necessary.
1319 template<int size>
1320 Output_data_got<64, false>*
1321 Target_x86_64<size>::got_section(Symbol_table* symtab, Layout* layout)
1323 if (this->got_ == NULL)
1325 gold_assert(symtab != NULL && layout != NULL);
1327 // When using -z now, we can treat .got.plt as a relro section.
1328 // Without -z now, it is modified after program startup by lazy
1329 // PLT relocations.
1330 bool is_got_plt_relro = parameters->options().now();
1331 Output_section_order got_order = (is_got_plt_relro
1332 ? ORDER_RELRO
1333 : ORDER_RELRO_LAST);
1334 Output_section_order got_plt_order = (is_got_plt_relro
1335 ? ORDER_RELRO
1336 : ORDER_NON_RELRO_FIRST);
1338 this->got_ = new Output_data_got<64, false>();
1340 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
1341 (elfcpp::SHF_ALLOC
1342 | elfcpp::SHF_WRITE),
1343 this->got_, got_order, true);
1345 this->got_plt_ = new Output_data_got_plt_x86_64(layout);
1346 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1347 (elfcpp::SHF_ALLOC
1348 | elfcpp::SHF_WRITE),
1349 this->got_plt_, got_plt_order,
1350 is_got_plt_relro);
1352 // The first three entries are reserved.
1353 this->got_plt_->set_current_data_size(3 * 8);
1355 if (!is_got_plt_relro)
1357 // Those bytes can go into the relro segment.
1358 layout->increase_relro(3 * 8);
1361 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
1362 this->global_offset_table_ =
1363 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
1364 Symbol_table::PREDEFINED,
1365 this->got_plt_,
1366 0, 0, elfcpp::STT_OBJECT,
1367 elfcpp::STB_LOCAL,
1368 elfcpp::STV_HIDDEN, 0,
1369 false, false);
1371 // If there are any IRELATIVE relocations, they get GOT entries
1372 // in .got.plt after the jump slot entries.
1373 this->got_irelative_ = new Output_data_space(8, "** GOT IRELATIVE PLT");
1374 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1375 (elfcpp::SHF_ALLOC
1376 | elfcpp::SHF_WRITE),
1377 this->got_irelative_,
1378 got_plt_order, is_got_plt_relro);
1380 // If there are any TLSDESC relocations, they get GOT entries in
1381 // .got.plt after the jump slot and IRELATIVE entries.
1382 this->got_tlsdesc_ = new Output_data_got<64, false>();
1383 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
1384 (elfcpp::SHF_ALLOC
1385 | elfcpp::SHF_WRITE),
1386 this->got_tlsdesc_,
1387 got_plt_order, is_got_plt_relro);
1390 return this->got_;
1393 // Get the dynamic reloc section, creating it if necessary.
1395 template<int size>
1396 typename Target_x86_64<size>::Reloc_section*
1397 Target_x86_64<size>::rela_dyn_section(Layout* layout)
1399 if (this->rela_dyn_ == NULL)
1401 gold_assert(layout != NULL);
1402 this->rela_dyn_ = new Reloc_section(parameters->options().combreloc());
1403 layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
1404 elfcpp::SHF_ALLOC, this->rela_dyn_,
1405 ORDER_DYNAMIC_RELOCS, false);
1407 return this->rela_dyn_;
1410 // Get the section to use for IRELATIVE relocs, creating it if
1411 // necessary. These go in .rela.dyn, but only after all other dynamic
1412 // relocations. They need to follow the other dynamic relocations so
1413 // that they can refer to global variables initialized by those
1414 // relocs.
1416 template<int size>
1417 typename Target_x86_64<size>::Reloc_section*
1418 Target_x86_64<size>::rela_irelative_section(Layout* layout)
1420 if (this->rela_irelative_ == NULL)
1422 // Make sure we have already created the dynamic reloc section.
1423 this->rela_dyn_section(layout);
1424 this->rela_irelative_ = new Reloc_section(false);
1425 layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
1426 elfcpp::SHF_ALLOC, this->rela_irelative_,
1427 ORDER_DYNAMIC_RELOCS, false);
1428 gold_assert(this->rela_dyn_->output_section()
1429 == this->rela_irelative_->output_section());
1431 return this->rela_irelative_;
1434 // Write the first three reserved words of the .got.plt section.
1435 // The remainder of the section is written while writing the PLT
1436 // in Output_data_plt_i386::do_write.
1438 void
1439 Output_data_got_plt_x86_64::do_write(Output_file* of)
1441 // The first entry in the GOT is the address of the .dynamic section
1442 // aka the PT_DYNAMIC segment. The next two entries are reserved.
1443 // We saved space for them when we created the section in
1444 // Target_x86_64::got_section.
1445 const off_t got_file_offset = this->offset();
1446 gold_assert(this->data_size() >= 24);
1447 unsigned char* const got_view = of->get_output_view(got_file_offset, 24);
1448 Output_section* dynamic = this->layout_->dynamic_section();
1449 uint64_t dynamic_addr = dynamic == NULL ? 0 : dynamic->address();
1450 elfcpp::Swap<64, false>::writeval(got_view, dynamic_addr);
1451 memset(got_view + 8, 0, 16);
1452 of->write_output_view(got_file_offset, 24, got_view);
1455 // Initialize the PLT section.
1457 template<int size>
1458 void
1459 Output_data_plt_x86_64<size>::init(Layout* layout)
1461 this->rel_ = new Reloc_section(false);
1462 layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
1463 elfcpp::SHF_ALLOC, this->rel_,
1464 ORDER_DYNAMIC_PLT_RELOCS, false);
1467 template<int size>
1468 void
1469 Output_data_plt_x86_64<size>::do_adjust_output_section(Output_section* os)
1471 os->set_entsize(this->get_plt_entry_size());
1474 // Add an entry to the PLT.
1476 template<int size>
1477 void
1478 Output_data_plt_x86_64<size>::add_entry(Symbol_table* symtab, Layout* layout,
1479 Symbol* gsym)
1481 gold_assert(!gsym->has_plt_offset());
1483 unsigned int plt_index;
1484 off_t plt_offset;
1485 section_offset_type got_offset;
1487 unsigned int* pcount;
1488 unsigned int offset;
1489 unsigned int reserved;
1490 Output_section_data_build* got;
1491 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1492 && gsym->can_use_relative_reloc(false))
1494 pcount = &this->irelative_count_;
1495 offset = 0;
1496 reserved = 0;
1497 got = this->got_irelative_;
1499 else
1501 pcount = &this->count_;
1502 offset = 1;
1503 reserved = 3;
1504 got = this->got_plt_;
1507 if (!this->is_data_size_valid())
1509 // Note that when setting the PLT offset for a non-IRELATIVE
1510 // entry we skip the initial reserved PLT entry.
1511 plt_index = *pcount + offset;
1512 plt_offset = plt_index * this->get_plt_entry_size();
1514 ++*pcount;
1516 got_offset = (plt_index - offset + reserved) * 8;
1517 gold_assert(got_offset == got->current_data_size());
1519 // Every PLT entry needs a GOT entry which points back to the PLT
1520 // entry (this will be changed by the dynamic linker, normally
1521 // lazily when the function is called).
1522 got->set_current_data_size(got_offset + 8);
1524 else
1526 // FIXME: This is probably not correct for IRELATIVE relocs.
1528 // For incremental updates, find an available slot.
1529 plt_offset = this->free_list_.allocate(this->get_plt_entry_size(),
1530 this->get_plt_entry_size(), 0);
1531 if (plt_offset == -1)
1532 gold_fallback(_("out of patch space (PLT);"
1533 " relink with --incremental-full"));
1535 // The GOT and PLT entries have a 1-1 correspondance, so the GOT offset
1536 // can be calculated from the PLT index, adjusting for the three
1537 // reserved entries at the beginning of the GOT.
1538 plt_index = plt_offset / this->get_plt_entry_size() - 1;
1539 got_offset = (plt_index - offset + reserved) * 8;
1542 gsym->set_plt_offset(plt_offset);
1544 // Every PLT entry needs a reloc.
1545 this->add_relocation(symtab, layout, gsym, got_offset);
1547 // Note that we don't need to save the symbol. The contents of the
1548 // PLT are independent of which symbols are used. The symbols only
1549 // appear in the relocations.
1552 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
1553 // the PLT offset.
1555 template<int size>
1556 unsigned int
1557 Output_data_plt_x86_64<size>::add_local_ifunc_entry(
1558 Symbol_table* symtab,
1559 Layout* layout,
1560 Sized_relobj_file<size, false>* relobj,
1561 unsigned int local_sym_index)
1563 unsigned int plt_offset = this->irelative_count_ * this->get_plt_entry_size();
1564 ++this->irelative_count_;
1566 section_offset_type got_offset = this->got_irelative_->current_data_size();
1568 // Every PLT entry needs a GOT entry which points back to the PLT
1569 // entry.
1570 this->got_irelative_->set_current_data_size(got_offset + 8);
1572 // Every PLT entry needs a reloc.
1573 Reloc_section* rela = this->rela_irelative(symtab, layout);
1574 rela->add_symbolless_local_addend(relobj, local_sym_index,
1575 elfcpp::R_X86_64_IRELATIVE,
1576 this->got_irelative_, got_offset, 0);
1578 return plt_offset;
1581 // Add the relocation for a PLT entry.
1583 template<int size>
1584 void
1585 Output_data_plt_x86_64<size>::add_relocation(Symbol_table* symtab,
1586 Layout* layout,
1587 Symbol* gsym,
1588 unsigned int got_offset)
1590 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1591 && gsym->can_use_relative_reloc(false))
1593 Reloc_section* rela = this->rela_irelative(symtab, layout);
1594 rela->add_symbolless_global_addend(gsym, elfcpp::R_X86_64_IRELATIVE,
1595 this->got_irelative_, got_offset, 0);
1597 else
1599 gsym->set_needs_dynsym_entry();
1600 this->rel_->add_global(gsym, elfcpp::R_X86_64_JUMP_SLOT, this->got_plt_,
1601 got_offset, 0);
1605 // Return where the TLSDESC relocations should go, creating it if
1606 // necessary. These follow the JUMP_SLOT relocations.
1608 template<int size>
1609 typename Output_data_plt_x86_64<size>::Reloc_section*
1610 Output_data_plt_x86_64<size>::rela_tlsdesc(Layout* layout)
1612 if (this->tlsdesc_rel_ == NULL)
1614 this->tlsdesc_rel_ = new Reloc_section(false);
1615 layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
1616 elfcpp::SHF_ALLOC, this->tlsdesc_rel_,
1617 ORDER_DYNAMIC_PLT_RELOCS, false);
1618 gold_assert(this->tlsdesc_rel_->output_section()
1619 == this->rel_->output_section());
1621 return this->tlsdesc_rel_;
1624 // Return where the IRELATIVE relocations should go in the PLT. These
1625 // follow the JUMP_SLOT and the TLSDESC relocations.
1627 template<int size>
1628 typename Output_data_plt_x86_64<size>::Reloc_section*
1629 Output_data_plt_x86_64<size>::rela_irelative(Symbol_table* symtab,
1630 Layout* layout)
1632 if (this->irelative_rel_ == NULL)
1634 // Make sure we have a place for the TLSDESC relocations, in
1635 // case we see any later on.
1636 this->rela_tlsdesc(layout);
1637 this->irelative_rel_ = new Reloc_section(false);
1638 layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
1639 elfcpp::SHF_ALLOC, this->irelative_rel_,
1640 ORDER_DYNAMIC_PLT_RELOCS, false);
1641 gold_assert(this->irelative_rel_->output_section()
1642 == this->rel_->output_section());
1644 if (parameters->doing_static_link())
1646 // A statically linked executable will only have a .rela.plt
1647 // section to hold R_X86_64_IRELATIVE relocs for
1648 // STT_GNU_IFUNC symbols. The library will use these
1649 // symbols to locate the IRELATIVE relocs at program startup
1650 // time.
1651 symtab->define_in_output_data("__rela_iplt_start", NULL,
1652 Symbol_table::PREDEFINED,
1653 this->irelative_rel_, 0, 0,
1654 elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1655 elfcpp::STV_HIDDEN, 0, false, true);
1656 symtab->define_in_output_data("__rela_iplt_end", NULL,
1657 Symbol_table::PREDEFINED,
1658 this->irelative_rel_, 0, 0,
1659 elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
1660 elfcpp::STV_HIDDEN, 0, true, true);
1663 return this->irelative_rel_;
1666 // Return the PLT address to use for a global symbol.
1668 template<int size>
1669 uint64_t
1670 Output_data_plt_x86_64<size>::do_address_for_global(const Symbol* gsym)
1672 uint64_t offset = 0;
1673 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1674 && gsym->can_use_relative_reloc(false))
1675 offset = (this->count_ + 1) * this->get_plt_entry_size();
1676 return this->address() + offset + gsym->plt_offset();
1679 // Return the PLT address to use for a local symbol. These are always
1680 // IRELATIVE relocs.
1682 template<int size>
1683 uint64_t
1684 Output_data_plt_x86_64<size>::do_address_for_local(const Relobj* object,
1685 unsigned int r_sym)
1687 return (this->address()
1688 + (this->count_ + 1) * this->get_plt_entry_size()
1689 + object->local_plt_offset(r_sym));
1692 // Set the final size.
1693 template<int size>
1694 void
1695 Output_data_plt_x86_64<size>::set_final_data_size()
1697 // Number of regular and IFUNC PLT entries, plus the first entry.
1698 unsigned int count = this->count_ + this->irelative_count_ + 1;
1699 // Count the TLSDESC entry, if present.
1700 if (this->has_tlsdesc_entry())
1701 ++count;
1702 this->set_data_size(count * this->get_plt_entry_size());
1705 // The first entry in the PLT for an executable.
1707 template<int size>
1708 const unsigned char
1709 Output_data_plt_x86_64_standard<size>::first_plt_entry[plt_entry_size] =
1711 // From AMD64 ABI Draft 0.98, page 76
1712 0xff, 0x35, // pushq contents of memory address
1713 0, 0, 0, 0, // replaced with address of .got + 8
1714 0xff, 0x25, // jmp indirect
1715 0, 0, 0, 0, // replaced with address of .got + 16
1716 0x90, 0x90, 0x90, 0x90 // noop (x4)
1719 template<int size>
1720 void
1721 Output_data_plt_x86_64_standard<size>::do_fill_first_plt_entry(
1722 unsigned char* pov,
1723 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
1724 typename elfcpp::Elf_types<size>::Elf_Addr plt_address)
1726 memcpy(pov, first_plt_entry, plt_entry_size);
1727 // We do a jmp relative to the PC at the end of this instruction.
1728 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1729 (got_address + 8
1730 - (plt_address + 6)));
1731 elfcpp::Swap<32, false>::writeval(pov + 8,
1732 (got_address + 16
1733 - (plt_address + 12)));
1736 // Subsequent entries in the PLT for an executable.
1738 template<int size>
1739 const unsigned char
1740 Output_data_plt_x86_64_standard<size>::plt_entry[plt_entry_size] =
1742 // From AMD64 ABI Draft 0.98, page 76
1743 0xff, 0x25, // jmpq indirect
1744 0, 0, 0, 0, // replaced with address of symbol in .got
1745 0x68, // pushq immediate
1746 0, 0, 0, 0, // replaced with offset into relocation table
1747 0xe9, // jmpq relative
1748 0, 0, 0, 0 // replaced with offset to start of .plt
1751 template<int size>
1752 unsigned int
1753 Output_data_plt_x86_64_standard<size>::do_fill_plt_entry(
1754 unsigned char* pov,
1755 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
1756 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
1757 unsigned int got_offset,
1758 unsigned int plt_offset,
1759 unsigned int plt_index)
1761 // Check PC-relative offset overflow in PLT entry.
1762 uint64_t plt_got_pcrel_offset = (got_address + got_offset
1763 - (plt_address + plt_offset + 6));
1764 if (Bits<32>::has_overflow(plt_got_pcrel_offset))
1765 gold_error(_("PC-relative offset overflow in PLT entry %d"),
1766 plt_index + 1);
1768 memcpy(pov, plt_entry, plt_entry_size);
1769 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1770 plt_got_pcrel_offset);
1772 elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_index);
1773 elfcpp::Swap<32, false>::writeval(pov + 12,
1774 - (plt_offset + plt_entry_size));
1776 return 6;
1779 // The reserved TLSDESC entry in the PLT for an executable.
1781 template<int size>
1782 const unsigned char
1783 Output_data_plt_x86_64_standard<size>::tlsdesc_plt_entry[plt_entry_size] =
1785 // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
1786 // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
1787 0xff, 0x35, // pushq x(%rip)
1788 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
1789 0xff, 0x25, // jmpq *y(%rip)
1790 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
1791 0x0f, 0x1f, // nop
1792 0x40, 0
1795 template<int size>
1796 void
1797 Output_data_plt_x86_64_standard<size>::do_fill_tlsdesc_entry(
1798 unsigned char* pov,
1799 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
1800 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
1801 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
1802 unsigned int tlsdesc_got_offset,
1803 unsigned int plt_offset)
1805 memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
1806 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1807 (got_address + 8
1808 - (plt_address + plt_offset
1809 + 6)));
1810 elfcpp::Swap_unaligned<32, false>::writeval(pov + 8,
1811 (got_base
1812 + tlsdesc_got_offset
1813 - (plt_address + plt_offset
1814 + 12)));
1817 // Return the APLT address to use for a global symbol (for -z bndplt).
1819 uint64_t
1820 Output_data_plt_x86_64_bnd::do_address_for_global(const Symbol* gsym)
1822 uint64_t offset = this->aplt_offset_;
1823 // Convert the PLT offset into an APLT offset.
1824 unsigned int plt_offset = gsym->plt_offset();
1825 if (gsym->type() == elfcpp::STT_GNU_IFUNC
1826 && gsym->can_use_relative_reloc(false))
1827 offset += this->regular_count() * aplt_entry_size;
1828 else
1829 plt_offset -= plt_entry_size;
1830 plt_offset = plt_offset / (plt_entry_size / aplt_entry_size);
1831 return this->address() + offset + plt_offset;
1834 // Return the PLT address to use for a local symbol. These are always
1835 // IRELATIVE relocs.
1837 uint64_t
1838 Output_data_plt_x86_64_bnd::do_address_for_local(const Relobj* object,
1839 unsigned int r_sym)
1841 // Convert the PLT offset into an APLT offset.
1842 unsigned int plt_offset = ((object->local_plt_offset(r_sym) - plt_entry_size)
1843 / (plt_entry_size / aplt_entry_size));
1844 return (this->address()
1845 + this->aplt_offset_
1846 + this->regular_count() * aplt_entry_size
1847 + plt_offset);
1850 // Set the final size.
1851 void
1852 Output_data_plt_x86_64_bnd::set_final_data_size()
1854 // Number of regular and IFUNC PLT entries.
1855 unsigned int count = this->entry_count();
1856 // Count the first entry and the TLSDESC entry, if present.
1857 unsigned int extra = this->has_tlsdesc_entry() ? 2 : 1;
1858 unsigned int plt_size = (count + extra) * plt_entry_size;
1859 // Offset of the APLT.
1860 this->aplt_offset_ = plt_size;
1861 // Size of the APLT.
1862 plt_size += count * aplt_entry_size;
1863 this->set_data_size(plt_size);
1866 // The first entry in the BND PLT.
1868 const unsigned char
1869 Output_data_plt_x86_64_bnd::first_plt_entry[plt_entry_size] =
1871 // From AMD64 ABI Draft 0.98, page 76
1872 0xff, 0x35, // pushq contents of memory address
1873 0, 0, 0, 0, // replaced with address of .got + 8
1874 0xf2, 0xff, 0x25, // bnd jmp indirect
1875 0, 0, 0, 0, // replaced with address of .got + 16
1876 0x0f, 0x1f, 0x00 // nop
1879 void
1880 Output_data_plt_x86_64_bnd::do_fill_first_plt_entry(
1881 unsigned char* pov,
1882 elfcpp::Elf_types<64>::Elf_Addr got_address,
1883 elfcpp::Elf_types<64>::Elf_Addr plt_address)
1885 memcpy(pov, first_plt_entry, plt_entry_size);
1886 // We do a jmp relative to the PC at the end of this instruction.
1887 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1888 (got_address + 8
1889 - (plt_address + 6)));
1890 elfcpp::Swap<32, false>::writeval(pov + 9,
1891 (got_address + 16
1892 - (plt_address + 13)));
1895 // Subsequent entries in the BND PLT.
1897 const unsigned char
1898 Output_data_plt_x86_64_bnd::plt_entry[plt_entry_size] =
1900 // From AMD64 ABI Draft 0.99.8, page 139
1901 0x68, // pushq immediate
1902 0, 0, 0, 0, // replaced with offset into relocation table
1903 0xf2, 0xe9, // bnd jmpq relative
1904 0, 0, 0, 0, // replaced with offset to start of .plt
1905 0x0f, 0x1f, 0x44, 0, 0 // nop
1908 // Entries in the BND Additional PLT.
1910 const unsigned char
1911 Output_data_plt_x86_64_bnd::aplt_entry[aplt_entry_size] =
1913 // From AMD64 ABI Draft 0.99.8, page 139
1914 0xf2, 0xff, 0x25, // bnd jmpq indirect
1915 0, 0, 0, 0, // replaced with address of symbol in .got
1916 0x90, // nop
1919 unsigned int
1920 Output_data_plt_x86_64_bnd::do_fill_plt_entry(
1921 unsigned char* pov,
1922 elfcpp::Elf_types<64>::Elf_Addr,
1923 elfcpp::Elf_types<64>::Elf_Addr,
1924 unsigned int,
1925 unsigned int plt_offset,
1926 unsigned int plt_index)
1928 memcpy(pov, plt_entry, plt_entry_size);
1929 elfcpp::Swap_unaligned<32, false>::writeval(pov + 1, plt_index);
1930 elfcpp::Swap<32, false>::writeval(pov + 7, -(plt_offset + 11));
1931 return 0;
1934 void
1935 Output_data_plt_x86_64_bnd::fill_aplt_entry(
1936 unsigned char* pov,
1937 elfcpp::Elf_types<64>::Elf_Addr got_address,
1938 elfcpp::Elf_types<64>::Elf_Addr plt_address,
1939 unsigned int got_offset,
1940 unsigned int plt_offset,
1941 unsigned int plt_index)
1943 // Check PC-relative offset overflow in PLT entry.
1944 uint64_t plt_got_pcrel_offset = (got_address + got_offset
1945 - (plt_address + plt_offset + 7));
1946 if (Bits<32>::has_overflow(plt_got_pcrel_offset))
1947 gold_error(_("PC-relative offset overflow in APLT entry %d"),
1948 plt_index + 1);
1950 memcpy(pov, aplt_entry, aplt_entry_size);
1951 elfcpp::Swap_unaligned<32, false>::writeval(pov + 3, plt_got_pcrel_offset);
1954 // The reserved TLSDESC entry in the PLT for an executable.
1956 const unsigned char
1957 Output_data_plt_x86_64_bnd::tlsdesc_plt_entry[plt_entry_size] =
1959 // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
1960 // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
1961 0xff, 0x35, // pushq x(%rip)
1962 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
1963 0xf2, 0xff, 0x25, // jmpq *y(%rip)
1964 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
1965 0x0f, 0x1f, 0 // nop
1968 void
1969 Output_data_plt_x86_64_bnd::do_fill_tlsdesc_entry(
1970 unsigned char* pov,
1971 elfcpp::Elf_types<64>::Elf_Addr got_address,
1972 elfcpp::Elf_types<64>::Elf_Addr plt_address,
1973 elfcpp::Elf_types<64>::Elf_Addr got_base,
1974 unsigned int tlsdesc_got_offset,
1975 unsigned int plt_offset)
1977 memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
1978 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
1979 (got_address + 8
1980 - (plt_address + plt_offset
1981 + 6)));
1982 elfcpp::Swap_unaligned<32, false>::writeval(pov + 9,
1983 (got_base
1984 + tlsdesc_got_offset
1985 - (plt_address + plt_offset
1986 + 13)));
1989 // The .eh_frame unwind information for the PLT.
1991 template<int size>
1992 const unsigned char
1993 Output_data_plt_x86_64<size>::plt_eh_frame_cie[plt_eh_frame_cie_size] =
1995 1, // CIE version.
1996 'z', // Augmentation: augmentation size included.
1997 'R', // Augmentation: FDE encoding included.
1998 '\0', // End of augmentation string.
1999 1, // Code alignment factor.
2000 0x78, // Data alignment factor.
2001 16, // Return address column.
2002 1, // Augmentation size.
2003 (elfcpp::DW_EH_PE_pcrel // FDE encoding.
2004 | elfcpp::DW_EH_PE_sdata4),
2005 elfcpp::DW_CFA_def_cfa, 7, 8, // DW_CFA_def_cfa: r7 (rsp) ofs 8.
2006 elfcpp::DW_CFA_offset + 16, 1,// DW_CFA_offset: r16 (rip) at cfa-8.
2007 elfcpp::DW_CFA_nop, // Align to 16 bytes.
2008 elfcpp::DW_CFA_nop
2011 template<int size>
2012 const unsigned char
2013 Output_data_plt_x86_64_standard<size>::plt_eh_frame_fde[plt_eh_frame_fde_size] =
2015 0, 0, 0, 0, // Replaced with offset to .plt.
2016 0, 0, 0, 0, // Replaced with size of .plt.
2017 0, // Augmentation size.
2018 elfcpp::DW_CFA_def_cfa_offset, 16, // DW_CFA_def_cfa_offset: 16.
2019 elfcpp::DW_CFA_advance_loc + 6, // Advance 6 to __PLT__ + 6.
2020 elfcpp::DW_CFA_def_cfa_offset, 24, // DW_CFA_def_cfa_offset: 24.
2021 elfcpp::DW_CFA_advance_loc + 10, // Advance 10 to __PLT__ + 16.
2022 elfcpp::DW_CFA_def_cfa_expression, // DW_CFA_def_cfa_expression.
2023 11, // Block length.
2024 elfcpp::DW_OP_breg7, 8, // Push %rsp + 8.
2025 elfcpp::DW_OP_breg16, 0, // Push %rip.
2026 elfcpp::DW_OP_lit15, // Push 0xf.
2027 elfcpp::DW_OP_and, // & (%rip & 0xf).
2028 elfcpp::DW_OP_lit11, // Push 0xb.
2029 elfcpp::DW_OP_ge, // >= ((%rip & 0xf) >= 0xb)
2030 elfcpp::DW_OP_lit3, // Push 3.
2031 elfcpp::DW_OP_shl, // << (((%rip & 0xf) >= 0xb) << 3)
2032 elfcpp::DW_OP_plus, // + ((((%rip&0xf)>=0xb)<<3)+%rsp+8
2033 elfcpp::DW_CFA_nop, // Align to 32 bytes.
2034 elfcpp::DW_CFA_nop,
2035 elfcpp::DW_CFA_nop,
2036 elfcpp::DW_CFA_nop
2039 // The .eh_frame unwind information for the BND PLT.
2040 const unsigned char
2041 Output_data_plt_x86_64_bnd::plt_eh_frame_fde[plt_eh_frame_fde_size] =
2043 0, 0, 0, 0, // Replaced with offset to .plt.
2044 0, 0, 0, 0, // Replaced with size of .plt.
2045 0, // Augmentation size.
2046 elfcpp::DW_CFA_def_cfa_offset, 16, // DW_CFA_def_cfa_offset: 16.
2047 elfcpp::DW_CFA_advance_loc + 6, // Advance 6 to __PLT__ + 6.
2048 elfcpp::DW_CFA_def_cfa_offset, 24, // DW_CFA_def_cfa_offset: 24.
2049 elfcpp::DW_CFA_advance_loc + 10, // Advance 10 to __PLT__ + 16.
2050 elfcpp::DW_CFA_def_cfa_expression, // DW_CFA_def_cfa_expression.
2051 11, // Block length.
2052 elfcpp::DW_OP_breg7, 8, // Push %rsp + 8.
2053 elfcpp::DW_OP_breg16, 0, // Push %rip.
2054 elfcpp::DW_OP_lit15, // Push 0xf.
2055 elfcpp::DW_OP_and, // & (%rip & 0xf).
2056 elfcpp::DW_OP_lit5, // Push 5.
2057 elfcpp::DW_OP_ge, // >= ((%rip & 0xf) >= 5)
2058 elfcpp::DW_OP_lit3, // Push 3.
2059 elfcpp::DW_OP_shl, // << (((%rip & 0xf) >= 5) << 3)
2060 elfcpp::DW_OP_plus, // + ((((%rip&0xf)>=5)<<3)+%rsp+8
2061 elfcpp::DW_CFA_nop, // Align to 32 bytes.
2062 elfcpp::DW_CFA_nop,
2063 elfcpp::DW_CFA_nop,
2064 elfcpp::DW_CFA_nop
2067 // Write out the PLT. This uses the hand-coded instructions above,
2068 // and adjusts them as needed. This is specified by the AMD64 ABI.
2070 template<int size>
2071 void
2072 Output_data_plt_x86_64<size>::do_write(Output_file* of)
2074 const off_t offset = this->offset();
2075 const section_size_type oview_size =
2076 convert_to_section_size_type(this->data_size());
2077 unsigned char* const oview = of->get_output_view(offset, oview_size);
2079 const off_t got_file_offset = this->got_plt_->offset();
2080 gold_assert(parameters->incremental_update()
2081 || (got_file_offset + this->got_plt_->data_size()
2082 == this->got_irelative_->offset()));
2083 const section_size_type got_size =
2084 convert_to_section_size_type(this->got_plt_->data_size()
2085 + this->got_irelative_->data_size());
2086 unsigned char* const got_view = of->get_output_view(got_file_offset,
2087 got_size);
2089 unsigned char* pov = oview;
2091 // The base address of the .plt section.
2092 typename elfcpp::Elf_types<size>::Elf_Addr plt_address = this->address();
2093 // The base address of the .got section.
2094 typename elfcpp::Elf_types<size>::Elf_Addr got_base = this->got_->address();
2095 // The base address of the PLT portion of the .got section,
2096 // which is where the GOT pointer will point, and where the
2097 // three reserved GOT entries are located.
2098 typename elfcpp::Elf_types<size>::Elf_Addr got_address
2099 = this->got_plt_->address();
2101 this->fill_first_plt_entry(pov, got_address, plt_address);
2102 pov += this->get_plt_entry_size();
2104 // The first three entries in the GOT are reserved, and are written
2105 // by Output_data_got_plt_x86_64::do_write.
2106 unsigned char* got_pov = got_view + 24;
2108 unsigned int plt_offset = this->get_plt_entry_size();
2109 unsigned int got_offset = 24;
2110 const unsigned int count = this->count_ + this->irelative_count_;
2111 for (unsigned int plt_index = 0;
2112 plt_index < count;
2113 ++plt_index,
2114 pov += this->get_plt_entry_size(),
2115 got_pov += 8,
2116 plt_offset += this->get_plt_entry_size(),
2117 got_offset += 8)
2119 // Set and adjust the PLT entry itself.
2120 unsigned int lazy_offset = this->fill_plt_entry(pov,
2121 got_address, plt_address,
2122 got_offset, plt_offset,
2123 plt_index);
2125 // Set the entry in the GOT.
2126 elfcpp::Swap<64, false>::writeval(got_pov,
2127 plt_address + plt_offset + lazy_offset);
2130 if (this->has_tlsdesc_entry())
2132 // Set and adjust the reserved TLSDESC PLT entry.
2133 unsigned int tlsdesc_got_offset = this->get_tlsdesc_got_offset();
2134 this->fill_tlsdesc_entry(pov, got_address, plt_address, got_base,
2135 tlsdesc_got_offset, plt_offset);
2136 pov += this->get_plt_entry_size();
2139 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
2140 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
2142 of->write_output_view(offset, oview_size, oview);
2143 of->write_output_view(got_file_offset, got_size, got_view);
2146 // Write out the BND PLT.
2148 void
2149 Output_data_plt_x86_64_bnd::do_write(Output_file* of)
2151 const off_t offset = this->offset();
2152 const section_size_type oview_size =
2153 convert_to_section_size_type(this->data_size());
2154 unsigned char* const oview = of->get_output_view(offset, oview_size);
2156 Output_data_got<64, false>* got = this->got();
2157 Output_data_got_plt_x86_64* got_plt = this->got_plt();
2158 Output_data_space* got_irelative = this->got_irelative();
2160 const off_t got_file_offset = got_plt->offset();
2161 gold_assert(parameters->incremental_update()
2162 || (got_file_offset + got_plt->data_size()
2163 == got_irelative->offset()));
2164 const section_size_type got_size =
2165 convert_to_section_size_type(got_plt->data_size()
2166 + got_irelative->data_size());
2167 unsigned char* const got_view = of->get_output_view(got_file_offset,
2168 got_size);
2170 unsigned char* pov = oview;
2172 // The base address of the .plt section.
2173 elfcpp::Elf_types<64>::Elf_Addr plt_address = this->address();
2174 // The base address of the .got section.
2175 elfcpp::Elf_types<64>::Elf_Addr got_base = got->address();
2176 // The base address of the PLT portion of the .got section,
2177 // which is where the GOT pointer will point, and where the
2178 // three reserved GOT entries are located.
2179 elfcpp::Elf_types<64>::Elf_Addr got_address = got_plt->address();
2181 this->fill_first_plt_entry(pov, got_address, plt_address);
2182 pov += plt_entry_size;
2184 // The first three entries in the GOT are reserved, and are written
2185 // by Output_data_got_plt_x86_64::do_write.
2186 unsigned char* got_pov = got_view + 24;
2188 unsigned int plt_offset = plt_entry_size;
2189 unsigned int got_offset = 24;
2190 const unsigned int count = this->entry_count();
2191 for (unsigned int plt_index = 0;
2192 plt_index < count;
2193 ++plt_index,
2194 pov += plt_entry_size,
2195 got_pov += 8,
2196 plt_offset += plt_entry_size,
2197 got_offset += 8)
2199 // Set and adjust the PLT entry itself.
2200 unsigned int lazy_offset = this->fill_plt_entry(pov,
2201 got_address, plt_address,
2202 got_offset, plt_offset,
2203 plt_index);
2205 // Set the entry in the GOT.
2206 elfcpp::Swap<64, false>::writeval(got_pov,
2207 plt_address + plt_offset + lazy_offset);
2210 if (this->has_tlsdesc_entry())
2212 // Set and adjust the reserved TLSDESC PLT entry.
2213 unsigned int tlsdesc_got_offset = this->get_tlsdesc_got_offset();
2214 this->fill_tlsdesc_entry(pov, got_address, plt_address, got_base,
2215 tlsdesc_got_offset, plt_offset);
2216 pov += this->get_plt_entry_size();
2219 // Write the additional PLT.
2220 got_offset = 24;
2221 for (unsigned int plt_index = 0;
2222 plt_index < count;
2223 ++plt_index,
2224 pov += aplt_entry_size,
2225 plt_offset += aplt_entry_size,
2226 got_offset += 8)
2228 // Set and adjust the PLT entry itself.
2229 this->fill_aplt_entry(pov, got_address, plt_address, got_offset,
2230 plt_offset, plt_index);
2233 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
2234 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
2236 of->write_output_view(offset, oview_size, oview);
2237 of->write_output_view(got_file_offset, got_size, got_view);
2240 // Create the PLT section.
2242 template<int size>
2243 void
2244 Target_x86_64<size>::make_plt_section(Symbol_table* symtab, Layout* layout)
2246 if (this->plt_ == NULL)
2248 // Create the GOT sections first.
2249 this->got_section(symtab, layout);
2251 this->plt_ = this->make_data_plt(layout, this->got_, this->got_plt_,
2252 this->got_irelative_);
2254 // Add unwind information if requested.
2255 if (parameters->options().ld_generated_unwind_info())
2256 this->plt_->add_eh_frame(layout);
2258 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
2259 (elfcpp::SHF_ALLOC
2260 | elfcpp::SHF_EXECINSTR),
2261 this->plt_, ORDER_PLT, false);
2263 // Make the sh_info field of .rela.plt point to .plt.
2264 Output_section* rela_plt_os = this->plt_->rela_plt()->output_section();
2265 rela_plt_os->set_info_section(this->plt_->output_section());
2269 template<>
2270 Output_data_plt_x86_64<32>*
2271 Target_x86_64<32>::do_make_data_plt(Layout* layout,
2272 Output_data_got<64, false>* got,
2273 Output_data_got_plt_x86_64* got_plt,
2274 Output_data_space* got_irelative)
2276 return new Output_data_plt_x86_64_standard<32>(layout, got, got_plt,
2277 got_irelative);
2280 template<>
2281 Output_data_plt_x86_64<64>*
2282 Target_x86_64<64>::do_make_data_plt(Layout* layout,
2283 Output_data_got<64, false>* got,
2284 Output_data_got_plt_x86_64* got_plt,
2285 Output_data_space* got_irelative)
2287 if (parameters->options().bndplt())
2288 return new Output_data_plt_x86_64_bnd(layout, got, got_plt,
2289 got_irelative);
2290 else
2291 return new Output_data_plt_x86_64_standard<64>(layout, got, got_plt,
2292 got_irelative);
2295 template<>
2296 Output_data_plt_x86_64<32>*
2297 Target_x86_64<32>::do_make_data_plt(Layout* layout,
2298 Output_data_got<64, false>* got,
2299 Output_data_got_plt_x86_64* got_plt,
2300 Output_data_space* got_irelative,
2301 unsigned int plt_count)
2303 return new Output_data_plt_x86_64_standard<32>(layout, got, got_plt,
2304 got_irelative,
2305 plt_count);
2308 template<>
2309 Output_data_plt_x86_64<64>*
2310 Target_x86_64<64>::do_make_data_plt(Layout* layout,
2311 Output_data_got<64, false>* got,
2312 Output_data_got_plt_x86_64* got_plt,
2313 Output_data_space* got_irelative,
2314 unsigned int plt_count)
2316 if (parameters->options().bndplt())
2317 return new Output_data_plt_x86_64_bnd(layout, got, got_plt,
2318 got_irelative, plt_count);
2319 else
2320 return new Output_data_plt_x86_64_standard<64>(layout, got, got_plt,
2321 got_irelative,
2322 plt_count);
2325 // Return the section for TLSDESC relocations.
2327 template<int size>
2328 typename Target_x86_64<size>::Reloc_section*
2329 Target_x86_64<size>::rela_tlsdesc_section(Layout* layout) const
2331 return this->plt_section()->rela_tlsdesc(layout);
2334 // Create a PLT entry for a global symbol.
2336 template<int size>
2337 void
2338 Target_x86_64<size>::make_plt_entry(Symbol_table* symtab, Layout* layout,
2339 Symbol* gsym)
2341 if (gsym->has_plt_offset())
2342 return;
2344 if (this->plt_ == NULL)
2345 this->make_plt_section(symtab, layout);
2347 this->plt_->add_entry(symtab, layout, gsym);
2350 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
2352 template<int size>
2353 void
2354 Target_x86_64<size>::make_local_ifunc_plt_entry(
2355 Symbol_table* symtab, Layout* layout,
2356 Sized_relobj_file<size, false>* relobj,
2357 unsigned int local_sym_index)
2359 if (relobj->local_has_plt_offset(local_sym_index))
2360 return;
2361 if (this->plt_ == NULL)
2362 this->make_plt_section(symtab, layout);
2363 unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout,
2364 relobj,
2365 local_sym_index);
2366 relobj->set_local_plt_offset(local_sym_index, plt_offset);
2369 // Return the number of entries in the PLT.
2371 template<int size>
2372 unsigned int
2373 Target_x86_64<size>::plt_entry_count() const
2375 if (this->plt_ == NULL)
2376 return 0;
2377 return this->plt_->entry_count();
2380 // Return the offset of the first non-reserved PLT entry.
2382 template<int size>
2383 unsigned int
2384 Target_x86_64<size>::first_plt_entry_offset() const
2386 if (this->plt_ == NULL)
2387 return 0;
2388 return this->plt_->first_plt_entry_offset();
2391 // Return the size of each PLT entry.
2393 template<int size>
2394 unsigned int
2395 Target_x86_64<size>::plt_entry_size() const
2397 if (this->plt_ == NULL)
2398 return 0;
2399 return this->plt_->get_plt_entry_size();
2402 // Create the GOT and PLT sections for an incremental update.
2404 template<int size>
2405 Output_data_got_base*
2406 Target_x86_64<size>::init_got_plt_for_update(Symbol_table* symtab,
2407 Layout* layout,
2408 unsigned int got_count,
2409 unsigned int plt_count)
2411 gold_assert(this->got_ == NULL);
2413 this->got_ = new Output_data_got<64, false>(got_count * 8);
2414 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
2415 (elfcpp::SHF_ALLOC
2416 | elfcpp::SHF_WRITE),
2417 this->got_, ORDER_RELRO_LAST,
2418 true);
2420 // Add the three reserved entries.
2421 this->got_plt_ = new Output_data_got_plt_x86_64(layout, (plt_count + 3) * 8);
2422 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
2423 (elfcpp::SHF_ALLOC
2424 | elfcpp::SHF_WRITE),
2425 this->got_plt_, ORDER_NON_RELRO_FIRST,
2426 false);
2428 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
2429 this->global_offset_table_ =
2430 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
2431 Symbol_table::PREDEFINED,
2432 this->got_plt_,
2433 0, 0, elfcpp::STT_OBJECT,
2434 elfcpp::STB_LOCAL,
2435 elfcpp::STV_HIDDEN, 0,
2436 false, false);
2438 // If there are any TLSDESC relocations, they get GOT entries in
2439 // .got.plt after the jump slot entries.
2440 // FIXME: Get the count for TLSDESC entries.
2441 this->got_tlsdesc_ = new Output_data_got<64, false>(0);
2442 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
2443 elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
2444 this->got_tlsdesc_,
2445 ORDER_NON_RELRO_FIRST, false);
2447 // If there are any IRELATIVE relocations, they get GOT entries in
2448 // .got.plt after the jump slot and TLSDESC entries.
2449 this->got_irelative_ = new Output_data_space(0, 8, "** GOT IRELATIVE PLT");
2450 layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
2451 elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
2452 this->got_irelative_,
2453 ORDER_NON_RELRO_FIRST, false);
2455 // Create the PLT section.
2456 this->plt_ = this->make_data_plt(layout, this->got_,
2457 this->got_plt_,
2458 this->got_irelative_,
2459 plt_count);
2461 // Add unwind information if requested.
2462 if (parameters->options().ld_generated_unwind_info())
2463 this->plt_->add_eh_frame(layout);
2465 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
2466 elfcpp::SHF_ALLOC | elfcpp::SHF_EXECINSTR,
2467 this->plt_, ORDER_PLT, false);
2469 // Make the sh_info field of .rela.plt point to .plt.
2470 Output_section* rela_plt_os = this->plt_->rela_plt()->output_section();
2471 rela_plt_os->set_info_section(this->plt_->output_section());
2473 // Create the rela_dyn section.
2474 this->rela_dyn_section(layout);
2476 return this->got_;
2479 // Reserve a GOT entry for a local symbol, and regenerate any
2480 // necessary dynamic relocations.
2482 template<int size>
2483 void
2484 Target_x86_64<size>::reserve_local_got_entry(
2485 unsigned int got_index,
2486 Sized_relobj<size, false>* obj,
2487 unsigned int r_sym,
2488 unsigned int got_type)
2490 unsigned int got_offset = got_index * 8;
2491 Reloc_section* rela_dyn = this->rela_dyn_section(NULL);
2493 this->got_->reserve_local(got_index, obj, r_sym, got_type);
2494 switch (got_type)
2496 case GOT_TYPE_STANDARD:
2497 if (parameters->options().output_is_position_independent())
2498 rela_dyn->add_local_relative(obj, r_sym, elfcpp::R_X86_64_RELATIVE,
2499 this->got_, got_offset, 0, false);
2500 break;
2501 case GOT_TYPE_TLS_OFFSET:
2502 rela_dyn->add_local(obj, r_sym, elfcpp::R_X86_64_TPOFF64,
2503 this->got_, got_offset, 0);
2504 break;
2505 case GOT_TYPE_TLS_PAIR:
2506 this->got_->reserve_slot(got_index + 1);
2507 rela_dyn->add_local(obj, r_sym, elfcpp::R_X86_64_DTPMOD64,
2508 this->got_, got_offset, 0);
2509 break;
2510 case GOT_TYPE_TLS_DESC:
2511 gold_fatal(_("TLS_DESC not yet supported for incremental linking"));
2512 // this->got_->reserve_slot(got_index + 1);
2513 // rela_dyn->add_target_specific(elfcpp::R_X86_64_TLSDESC, arg,
2514 // this->got_, got_offset, 0);
2515 break;
2516 default:
2517 gold_unreachable();
2521 // Reserve a GOT entry for a global symbol, and regenerate any
2522 // necessary dynamic relocations.
2524 template<int size>
2525 void
2526 Target_x86_64<size>::reserve_global_got_entry(unsigned int got_index,
2527 Symbol* gsym,
2528 unsigned int got_type)
2530 unsigned int got_offset = got_index * 8;
2531 Reloc_section* rela_dyn = this->rela_dyn_section(NULL);
2533 this->got_->reserve_global(got_index, gsym, got_type);
2534 switch (got_type)
2536 case GOT_TYPE_STANDARD:
2537 if (!gsym->final_value_is_known())
2539 if (gsym->is_from_dynobj()
2540 || gsym->is_undefined()
2541 || gsym->is_preemptible()
2542 || gsym->type() == elfcpp::STT_GNU_IFUNC)
2543 rela_dyn->add_global(gsym, elfcpp::R_X86_64_GLOB_DAT,
2544 this->got_, got_offset, 0);
2545 else
2546 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_RELATIVE,
2547 this->got_, got_offset, 0, false);
2549 break;
2550 case GOT_TYPE_TLS_OFFSET:
2551 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_TPOFF64,
2552 this->got_, got_offset, 0, false);
2553 break;
2554 case GOT_TYPE_TLS_PAIR:
2555 this->got_->reserve_slot(got_index + 1);
2556 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_DTPMOD64,
2557 this->got_, got_offset, 0, false);
2558 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_DTPOFF64,
2559 this->got_, got_offset + 8, 0, false);
2560 break;
2561 case GOT_TYPE_TLS_DESC:
2562 this->got_->reserve_slot(got_index + 1);
2563 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_TLSDESC,
2564 this->got_, got_offset, 0, false);
2565 break;
2566 default:
2567 gold_unreachable();
2571 // Register an existing PLT entry for a global symbol.
2573 template<int size>
2574 void
2575 Target_x86_64<size>::register_global_plt_entry(Symbol_table* symtab,
2576 Layout* layout,
2577 unsigned int plt_index,
2578 Symbol* gsym)
2580 gold_assert(this->plt_ != NULL);
2581 gold_assert(!gsym->has_plt_offset());
2583 this->plt_->reserve_slot(plt_index);
2585 gsym->set_plt_offset((plt_index + 1) * this->plt_entry_size());
2587 unsigned int got_offset = (plt_index + 3) * 8;
2588 this->plt_->add_relocation(symtab, layout, gsym, got_offset);
2591 // Force a COPY relocation for a given symbol.
2593 template<int size>
2594 void
2595 Target_x86_64<size>::emit_copy_reloc(
2596 Symbol_table* symtab, Symbol* sym, Output_section* os, off_t offset)
2598 this->copy_relocs_.emit_copy_reloc(symtab,
2599 symtab->get_sized_symbol<size>(sym),
2601 offset,
2602 this->rela_dyn_section(NULL));
2605 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
2607 template<int size>
2608 void
2609 Target_x86_64<size>::define_tls_base_symbol(Symbol_table* symtab,
2610 Layout* layout)
2612 if (this->tls_base_symbol_defined_)
2613 return;
2615 Output_segment* tls_segment = layout->tls_segment();
2616 if (tls_segment != NULL)
2618 bool is_exec = parameters->options().output_is_executable();
2619 symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
2620 Symbol_table::PREDEFINED,
2621 tls_segment, 0, 0,
2622 elfcpp::STT_TLS,
2623 elfcpp::STB_LOCAL,
2624 elfcpp::STV_HIDDEN, 0,
2625 (is_exec
2626 ? Symbol::SEGMENT_END
2627 : Symbol::SEGMENT_START),
2628 true);
2630 this->tls_base_symbol_defined_ = true;
2633 // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
2635 template<int size>
2636 void
2637 Target_x86_64<size>::reserve_tlsdesc_entries(Symbol_table* symtab,
2638 Layout* layout)
2640 if (this->plt_ == NULL)
2641 this->make_plt_section(symtab, layout);
2643 if (!this->plt_->has_tlsdesc_entry())
2645 // Allocate the TLSDESC_GOT entry.
2646 Output_data_got<64, false>* got = this->got_section(symtab, layout);
2647 unsigned int got_offset = got->add_constant(0);
2649 // Allocate the TLSDESC_PLT entry.
2650 this->plt_->reserve_tlsdesc_entry(got_offset);
2654 // Create a GOT entry for the TLS module index.
2656 template<int size>
2657 unsigned int
2658 Target_x86_64<size>::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
2659 Sized_relobj_file<size, false>* object)
2661 if (this->got_mod_index_offset_ == -1U)
2663 gold_assert(symtab != NULL && layout != NULL && object != NULL);
2664 Reloc_section* rela_dyn = this->rela_dyn_section(layout);
2665 Output_data_got<64, false>* got = this->got_section(symtab, layout);
2666 unsigned int got_offset = got->add_constant(0);
2667 rela_dyn->add_local(object, 0, elfcpp::R_X86_64_DTPMOD64, got,
2668 got_offset, 0);
2669 got->add_constant(0);
2670 this->got_mod_index_offset_ = got_offset;
2672 return this->got_mod_index_offset_;
2675 // Optimize the TLS relocation type based on what we know about the
2676 // symbol. IS_FINAL is true if the final address of this symbol is
2677 // known at link time.
2679 template<int size>
2680 tls::Tls_optimization
2681 Target_x86_64<size>::optimize_tls_reloc(bool is_final, int r_type)
2683 // If we are generating a shared library, then we can't do anything
2684 // in the linker.
2685 if (parameters->options().shared())
2686 return tls::TLSOPT_NONE;
2688 switch (r_type)
2690 case elfcpp::R_X86_64_TLSGD:
2691 case elfcpp::R_X86_64_GOTPC32_TLSDESC:
2692 case elfcpp::R_X86_64_TLSDESC_CALL:
2693 // These are General-Dynamic which permits fully general TLS
2694 // access. Since we know that we are generating an executable,
2695 // we can convert this to Initial-Exec. If we also know that
2696 // this is a local symbol, we can further switch to Local-Exec.
2697 if (is_final)
2698 return tls::TLSOPT_TO_LE;
2699 return tls::TLSOPT_TO_IE;
2701 case elfcpp::R_X86_64_TLSLD:
2702 // This is Local-Dynamic, which refers to a local symbol in the
2703 // dynamic TLS block. Since we know that we generating an
2704 // executable, we can switch to Local-Exec.
2705 return tls::TLSOPT_TO_LE;
2707 case elfcpp::R_X86_64_DTPOFF32:
2708 case elfcpp::R_X86_64_DTPOFF64:
2709 // Another Local-Dynamic reloc.
2710 return tls::TLSOPT_TO_LE;
2712 case elfcpp::R_X86_64_GOTTPOFF:
2713 // These are Initial-Exec relocs which get the thread offset
2714 // from the GOT. If we know that we are linking against the
2715 // local symbol, we can switch to Local-Exec, which links the
2716 // thread offset into the instruction.
2717 if (is_final)
2718 return tls::TLSOPT_TO_LE;
2719 return tls::TLSOPT_NONE;
2721 case elfcpp::R_X86_64_TPOFF32:
2722 // When we already have Local-Exec, there is nothing further we
2723 // can do.
2724 return tls::TLSOPT_NONE;
2726 default:
2727 gold_unreachable();
2731 // Get the Reference_flags for a particular relocation.
2733 template<int size>
2735 Target_x86_64<size>::Scan::get_reference_flags(unsigned int r_type)
2737 switch (r_type)
2739 case elfcpp::R_X86_64_NONE:
2740 case elfcpp::R_X86_64_GNU_VTINHERIT:
2741 case elfcpp::R_X86_64_GNU_VTENTRY:
2742 case elfcpp::R_X86_64_GOTPC32:
2743 case elfcpp::R_X86_64_GOTPC64:
2744 // No symbol reference.
2745 return 0;
2747 case elfcpp::R_X86_64_64:
2748 case elfcpp::R_X86_64_32:
2749 case elfcpp::R_X86_64_32S:
2750 case elfcpp::R_X86_64_16:
2751 case elfcpp::R_X86_64_8:
2752 return Symbol::ABSOLUTE_REF;
2754 case elfcpp::R_X86_64_PC64:
2755 case elfcpp::R_X86_64_PC32:
2756 case elfcpp::R_X86_64_PC32_BND:
2757 case elfcpp::R_X86_64_PC16:
2758 case elfcpp::R_X86_64_PC8:
2759 case elfcpp::R_X86_64_GOTOFF64:
2760 return Symbol::RELATIVE_REF;
2762 case elfcpp::R_X86_64_PLT32:
2763 case elfcpp::R_X86_64_PLT32_BND:
2764 case elfcpp::R_X86_64_PLTOFF64:
2765 return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
2767 case elfcpp::R_X86_64_GOT64:
2768 case elfcpp::R_X86_64_GOT32:
2769 case elfcpp::R_X86_64_GOTPCREL64:
2770 case elfcpp::R_X86_64_GOTPCREL:
2771 case elfcpp::R_X86_64_GOTPCRELX:
2772 case elfcpp::R_X86_64_REX_GOTPCRELX:
2773 case elfcpp::R_X86_64_GOTPLT64:
2774 // Absolute in GOT.
2775 return Symbol::ABSOLUTE_REF;
2777 case elfcpp::R_X86_64_TLSGD: // Global-dynamic
2778 case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
2779 case elfcpp::R_X86_64_TLSDESC_CALL:
2780 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
2781 case elfcpp::R_X86_64_DTPOFF32:
2782 case elfcpp::R_X86_64_DTPOFF64:
2783 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
2784 case elfcpp::R_X86_64_TPOFF32: // Local-exec
2785 return Symbol::TLS_REF;
2787 case elfcpp::R_X86_64_COPY:
2788 case elfcpp::R_X86_64_GLOB_DAT:
2789 case elfcpp::R_X86_64_JUMP_SLOT:
2790 case elfcpp::R_X86_64_RELATIVE:
2791 case elfcpp::R_X86_64_IRELATIVE:
2792 case elfcpp::R_X86_64_TPOFF64:
2793 case elfcpp::R_X86_64_DTPMOD64:
2794 case elfcpp::R_X86_64_TLSDESC:
2795 case elfcpp::R_X86_64_SIZE32:
2796 case elfcpp::R_X86_64_SIZE64:
2797 default:
2798 // Not expected. We will give an error later.
2799 return 0;
2803 // Report an unsupported relocation against a local symbol.
2805 template<int size>
2806 void
2807 Target_x86_64<size>::Scan::unsupported_reloc_local(
2808 Sized_relobj_file<size, false>* object,
2809 unsigned int r_type)
2811 gold_error(_("%s: unsupported reloc %u against local symbol"),
2812 object->name().c_str(), r_type);
2815 // We are about to emit a dynamic relocation of type R_TYPE. If the
2816 // dynamic linker does not support it, issue an error. The GNU linker
2817 // only issues a non-PIC error for an allocated read-only section.
2818 // Here we know the section is allocated, but we don't know that it is
2819 // read-only. But we check for all the relocation types which the
2820 // glibc dynamic linker supports, so it seems appropriate to issue an
2821 // error even if the section is not read-only. If GSYM is not NULL,
2822 // it is the symbol the relocation is against; if it is NULL, the
2823 // relocation is against a local symbol.
2825 template<int size>
2826 void
2827 Target_x86_64<size>::Scan::check_non_pic(Relobj* object, unsigned int r_type,
2828 Symbol* gsym)
2830 switch (r_type)
2832 // These are the relocation types supported by glibc for x86_64
2833 // which should always work.
2834 case elfcpp::R_X86_64_RELATIVE:
2835 case elfcpp::R_X86_64_IRELATIVE:
2836 case elfcpp::R_X86_64_GLOB_DAT:
2837 case elfcpp::R_X86_64_JUMP_SLOT:
2838 case elfcpp::R_X86_64_DTPMOD64:
2839 case elfcpp::R_X86_64_DTPOFF64:
2840 case elfcpp::R_X86_64_TPOFF64:
2841 case elfcpp::R_X86_64_64:
2842 case elfcpp::R_X86_64_COPY:
2843 return;
2845 // glibc supports these reloc types, but they can overflow.
2846 case elfcpp::R_X86_64_PC32:
2847 case elfcpp::R_X86_64_PC32_BND:
2848 // A PC relative reference is OK against a local symbol or if
2849 // the symbol is defined locally.
2850 if (gsym == NULL
2851 || (!gsym->is_from_dynobj()
2852 && !gsym->is_undefined()
2853 && !gsym->is_preemptible()))
2854 return;
2855 // Fall through.
2856 case elfcpp::R_X86_64_32:
2857 // R_X86_64_32 is OK for x32.
2858 if (size == 32 && r_type == elfcpp::R_X86_64_32)
2859 return;
2860 if (this->issued_non_pic_error_)
2861 return;
2862 gold_assert(parameters->options().output_is_position_independent());
2863 if (gsym == NULL)
2864 object->error(_("requires dynamic R_X86_64_32 reloc which may "
2865 "overflow at runtime; recompile with -fPIC"));
2866 else
2868 const char *r_name;
2869 switch (r_type)
2871 case elfcpp::R_X86_64_32:
2872 r_name = "R_X86_64_32";
2873 break;
2874 case elfcpp::R_X86_64_PC32:
2875 r_name = "R_X86_64_PC32";
2876 break;
2877 case elfcpp::R_X86_64_PC32_BND:
2878 r_name = "R_X86_64_PC32_BND";
2879 break;
2880 default:
2881 gold_unreachable();
2882 break;
2884 object->error(_("requires dynamic %s reloc against '%s' "
2885 "which may overflow at runtime; recompile "
2886 "with -fPIC"),
2887 r_name, gsym->name());
2889 this->issued_non_pic_error_ = true;
2890 return;
2892 default:
2893 // This prevents us from issuing more than one error per reloc
2894 // section. But we can still wind up issuing more than one
2895 // error per object file.
2896 if (this->issued_non_pic_error_)
2897 return;
2898 gold_assert(parameters->options().output_is_position_independent());
2899 object->error(_("requires unsupported dynamic reloc %u; "
2900 "recompile with -fPIC"),
2901 r_type);
2902 this->issued_non_pic_error_ = true;
2903 return;
2905 case elfcpp::R_X86_64_NONE:
2906 gold_unreachable();
2910 // Return whether we need to make a PLT entry for a relocation of the
2911 // given type against a STT_GNU_IFUNC symbol.
2913 template<int size>
2914 bool
2915 Target_x86_64<size>::Scan::reloc_needs_plt_for_ifunc(
2916 Sized_relobj_file<size, false>* object,
2917 unsigned int r_type)
2919 int flags = Scan::get_reference_flags(r_type);
2920 if (flags & Symbol::TLS_REF)
2921 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
2922 object->name().c_str(), r_type);
2923 return flags != 0;
2926 // Scan a relocation for a local symbol.
2928 template<int size>
2929 inline void
2930 Target_x86_64<size>::Scan::local(Symbol_table* symtab,
2931 Layout* layout,
2932 Target_x86_64<size>* target,
2933 Sized_relobj_file<size, false>* object,
2934 unsigned int data_shndx,
2935 Output_section* output_section,
2936 const elfcpp::Rela<size, false>& reloc,
2937 unsigned int r_type,
2938 const elfcpp::Sym<size, false>& lsym,
2939 bool is_discarded)
2941 if (is_discarded)
2942 return;
2944 // A local STT_GNU_IFUNC symbol may require a PLT entry.
2945 bool is_ifunc = lsym.get_st_type() == elfcpp::STT_GNU_IFUNC;
2946 if (is_ifunc && this->reloc_needs_plt_for_ifunc(object, r_type))
2948 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2949 target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
2952 switch (r_type)
2954 case elfcpp::R_X86_64_NONE:
2955 case elfcpp::R_X86_64_GNU_VTINHERIT:
2956 case elfcpp::R_X86_64_GNU_VTENTRY:
2957 break;
2959 case elfcpp::R_X86_64_64:
2960 // If building a shared library (or a position-independent
2961 // executable), we need to create a dynamic relocation for this
2962 // location. The relocation applied at link time will apply the
2963 // link-time value, so we flag the location with an
2964 // R_X86_64_RELATIVE relocation so the dynamic loader can
2965 // relocate it easily.
2966 if (parameters->options().output_is_position_independent())
2968 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2969 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2970 rela_dyn->add_local_relative(object, r_sym,
2971 (size == 32
2972 ? elfcpp::R_X86_64_RELATIVE64
2973 : elfcpp::R_X86_64_RELATIVE),
2974 output_section, data_shndx,
2975 reloc.get_r_offset(),
2976 reloc.get_r_addend(), is_ifunc);
2978 break;
2980 case elfcpp::R_X86_64_32:
2981 case elfcpp::R_X86_64_32S:
2982 case elfcpp::R_X86_64_16:
2983 case elfcpp::R_X86_64_8:
2984 // If building a shared library (or a position-independent
2985 // executable), we need to create a dynamic relocation for this
2986 // location. We can't use an R_X86_64_RELATIVE relocation
2987 // because that is always a 64-bit relocation.
2988 if (parameters->options().output_is_position_independent())
2990 // Use R_X86_64_RELATIVE relocation for R_X86_64_32 under x32.
2991 if (size == 32 && r_type == elfcpp::R_X86_64_32)
2993 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
2994 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
2995 rela_dyn->add_local_relative(object, r_sym,
2996 elfcpp::R_X86_64_RELATIVE,
2997 output_section, data_shndx,
2998 reloc.get_r_offset(),
2999 reloc.get_r_addend(), is_ifunc);
3000 break;
3003 this->check_non_pic(object, r_type, NULL);
3005 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
3006 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
3007 if (lsym.get_st_type() != elfcpp::STT_SECTION)
3008 rela_dyn->add_local(object, r_sym, r_type, output_section,
3009 data_shndx, reloc.get_r_offset(),
3010 reloc.get_r_addend());
3011 else
3013 gold_assert(lsym.get_st_value() == 0);
3014 unsigned int shndx = lsym.get_st_shndx();
3015 bool is_ordinary;
3016 shndx = object->adjust_sym_shndx(r_sym, shndx,
3017 &is_ordinary);
3018 if (!is_ordinary)
3019 object->error(_("section symbol %u has bad shndx %u"),
3020 r_sym, shndx);
3021 else
3022 rela_dyn->add_local_section(object, shndx,
3023 r_type, output_section,
3024 data_shndx, reloc.get_r_offset(),
3025 reloc.get_r_addend());
3028 break;
3030 case elfcpp::R_X86_64_PC64:
3031 case elfcpp::R_X86_64_PC32:
3032 case elfcpp::R_X86_64_PC32_BND:
3033 case elfcpp::R_X86_64_PC16:
3034 case elfcpp::R_X86_64_PC8:
3035 break;
3037 case elfcpp::R_X86_64_PLT32:
3038 case elfcpp::R_X86_64_PLT32_BND:
3039 // Since we know this is a local symbol, we can handle this as a
3040 // PC32 reloc.
3041 break;
3043 case elfcpp::R_X86_64_GOTPC32:
3044 case elfcpp::R_X86_64_GOTOFF64:
3045 case elfcpp::R_X86_64_GOTPC64:
3046 case elfcpp::R_X86_64_PLTOFF64:
3047 // We need a GOT section.
3048 target->got_section(symtab, layout);
3049 // For PLTOFF64, we'd normally want a PLT section, but since we
3050 // know this is a local symbol, no PLT is needed.
3051 break;
3053 case elfcpp::R_X86_64_GOT64:
3054 case elfcpp::R_X86_64_GOT32:
3055 case elfcpp::R_X86_64_GOTPCREL64:
3056 case elfcpp::R_X86_64_GOTPCREL:
3057 case elfcpp::R_X86_64_GOTPCRELX:
3058 case elfcpp::R_X86_64_REX_GOTPCRELX:
3059 case elfcpp::R_X86_64_GOTPLT64:
3061 // The symbol requires a GOT section.
3062 Output_data_got<64, false>* got = target->got_section(symtab, layout);
3064 // If the relocation symbol isn't IFUNC,
3065 // and is local, then we will convert
3066 // mov foo@GOTPCREL(%rip), %reg
3067 // to lea foo(%rip), %reg.
3068 // in Relocate::relocate.
3069 if ((r_type == elfcpp::R_X86_64_GOTPCREL
3070 || r_type == elfcpp::R_X86_64_GOTPCRELX
3071 || r_type == elfcpp::R_X86_64_REX_GOTPCRELX)
3072 && reloc.get_r_offset() >= 2
3073 && !is_ifunc)
3075 section_size_type stype;
3076 const unsigned char* view = object->section_contents(data_shndx,
3077 &stype, true);
3078 if (view[reloc.get_r_offset() - 2] == 0x8b)
3079 break;
3083 // The symbol requires a GOT entry.
3084 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
3086 // For a STT_GNU_IFUNC symbol we want the PLT offset. That
3087 // lets function pointers compare correctly with shared
3088 // libraries. Otherwise we would need an IRELATIVE reloc.
3089 bool is_new;
3090 if (is_ifunc)
3091 is_new = got->add_local_plt(object, r_sym, GOT_TYPE_STANDARD);
3092 else
3093 is_new = got->add_local(object, r_sym, GOT_TYPE_STANDARD);
3094 if (is_new)
3096 // If we are generating a shared object, we need to add a
3097 // dynamic relocation for this symbol's GOT entry.
3098 if (parameters->options().output_is_position_independent())
3100 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
3101 // R_X86_64_RELATIVE assumes a 64-bit relocation.
3102 if (r_type != elfcpp::R_X86_64_GOT32)
3104 unsigned int got_offset =
3105 object->local_got_offset(r_sym, GOT_TYPE_STANDARD);
3106 rela_dyn->add_local_relative(object, r_sym,
3107 elfcpp::R_X86_64_RELATIVE,
3108 got, got_offset, 0, is_ifunc);
3110 else
3112 this->check_non_pic(object, r_type, NULL);
3114 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
3115 rela_dyn->add_local(
3116 object, r_sym, r_type, got,
3117 object->local_got_offset(r_sym, GOT_TYPE_STANDARD), 0);
3121 // For GOTPLT64, we'd normally want a PLT section, but since
3122 // we know this is a local symbol, no PLT is needed.
3124 break;
3126 case elfcpp::R_X86_64_COPY:
3127 case elfcpp::R_X86_64_GLOB_DAT:
3128 case elfcpp::R_X86_64_JUMP_SLOT:
3129 case elfcpp::R_X86_64_RELATIVE:
3130 case elfcpp::R_X86_64_IRELATIVE:
3131 // These are outstanding tls relocs, which are unexpected when linking
3132 case elfcpp::R_X86_64_TPOFF64:
3133 case elfcpp::R_X86_64_DTPMOD64:
3134 case elfcpp::R_X86_64_TLSDESC:
3135 gold_error(_("%s: unexpected reloc %u in object file"),
3136 object->name().c_str(), r_type);
3137 break;
3139 // These are initial tls relocs, which are expected when linking
3140 case elfcpp::R_X86_64_TLSGD: // Global-dynamic
3141 case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
3142 case elfcpp::R_X86_64_TLSDESC_CALL:
3143 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
3144 case elfcpp::R_X86_64_DTPOFF32:
3145 case elfcpp::R_X86_64_DTPOFF64:
3146 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
3147 case elfcpp::R_X86_64_TPOFF32: // Local-exec
3149 bool output_is_shared = parameters->options().shared();
3150 const tls::Tls_optimization optimized_type
3151 = Target_x86_64<size>::optimize_tls_reloc(!output_is_shared,
3152 r_type);
3153 switch (r_type)
3155 case elfcpp::R_X86_64_TLSGD: // General-dynamic
3156 if (optimized_type == tls::TLSOPT_NONE)
3158 // Create a pair of GOT entries for the module index and
3159 // dtv-relative offset.
3160 Output_data_got<64, false>* got
3161 = target->got_section(symtab, layout);
3162 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
3163 unsigned int shndx = lsym.get_st_shndx();
3164 bool is_ordinary;
3165 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
3166 if (!is_ordinary)
3167 object->error(_("local symbol %u has bad shndx %u"),
3168 r_sym, shndx);
3169 else
3170 got->add_local_pair_with_rel(object, r_sym,
3171 shndx,
3172 GOT_TYPE_TLS_PAIR,
3173 target->rela_dyn_section(layout),
3174 elfcpp::R_X86_64_DTPMOD64);
3176 else if (optimized_type != tls::TLSOPT_TO_LE)
3177 unsupported_reloc_local(object, r_type);
3178 break;
3180 case elfcpp::R_X86_64_GOTPC32_TLSDESC:
3181 target->define_tls_base_symbol(symtab, layout);
3182 if (optimized_type == tls::TLSOPT_NONE)
3184 // Create reserved PLT and GOT entries for the resolver.
3185 target->reserve_tlsdesc_entries(symtab, layout);
3187 // Generate a double GOT entry with an
3188 // R_X86_64_TLSDESC reloc. The R_X86_64_TLSDESC reloc
3189 // is resolved lazily, so the GOT entry needs to be in
3190 // an area in .got.plt, not .got. Call got_section to
3191 // make sure the section has been created.
3192 target->got_section(symtab, layout);
3193 Output_data_got<64, false>* got = target->got_tlsdesc_section();
3194 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
3195 if (!object->local_has_got_offset(r_sym, GOT_TYPE_TLS_DESC))
3197 unsigned int got_offset = got->add_constant(0);
3198 got->add_constant(0);
3199 object->set_local_got_offset(r_sym, GOT_TYPE_TLS_DESC,
3200 got_offset);
3201 Reloc_section* rt = target->rela_tlsdesc_section(layout);
3202 // We store the arguments we need in a vector, and
3203 // use the index into the vector as the parameter
3204 // to pass to the target specific routines.
3205 uintptr_t intarg = target->add_tlsdesc_info(object, r_sym);
3206 void* arg = reinterpret_cast<void*>(intarg);
3207 rt->add_target_specific(elfcpp::R_X86_64_TLSDESC, arg,
3208 got, got_offset, 0);
3211 else if (optimized_type != tls::TLSOPT_TO_LE)
3212 unsupported_reloc_local(object, r_type);
3213 break;
3215 case elfcpp::R_X86_64_TLSDESC_CALL:
3216 break;
3218 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
3219 if (optimized_type == tls::TLSOPT_NONE)
3221 // Create a GOT entry for the module index.
3222 target->got_mod_index_entry(symtab, layout, object);
3224 else if (optimized_type != tls::TLSOPT_TO_LE)
3225 unsupported_reloc_local(object, r_type);
3226 break;
3228 case elfcpp::R_X86_64_DTPOFF32:
3229 case elfcpp::R_X86_64_DTPOFF64:
3230 break;
3232 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
3233 layout->set_has_static_tls();
3234 if (optimized_type == tls::TLSOPT_NONE)
3236 // Create a GOT entry for the tp-relative offset.
3237 Output_data_got<64, false>* got
3238 = target->got_section(symtab, layout);
3239 unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
3240 got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
3241 target->rela_dyn_section(layout),
3242 elfcpp::R_X86_64_TPOFF64);
3244 else if (optimized_type != tls::TLSOPT_TO_LE)
3245 unsupported_reloc_local(object, r_type);
3246 break;
3248 case elfcpp::R_X86_64_TPOFF32: // Local-exec
3249 layout->set_has_static_tls();
3250 if (output_is_shared)
3251 unsupported_reloc_local(object, r_type);
3252 break;
3254 default:
3255 gold_unreachable();
3258 break;
3260 case elfcpp::R_X86_64_SIZE32:
3261 case elfcpp::R_X86_64_SIZE64:
3262 default:
3263 gold_error(_("%s: unsupported reloc %u against local symbol"),
3264 object->name().c_str(), r_type);
3265 break;
3270 // Report an unsupported relocation against a global symbol.
3272 template<int size>
3273 void
3274 Target_x86_64<size>::Scan::unsupported_reloc_global(
3275 Sized_relobj_file<size, false>* object,
3276 unsigned int r_type,
3277 Symbol* gsym)
3279 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
3280 object->name().c_str(), r_type, gsym->demangled_name().c_str());
3283 // Returns true if this relocation type could be that of a function pointer.
3284 template<int size>
3285 inline bool
3286 Target_x86_64<size>::Scan::possible_function_pointer_reloc(
3287 Sized_relobj_file<size, false>* src_obj,
3288 unsigned int src_indx,
3289 unsigned int r_offset,
3290 unsigned int r_type)
3292 switch (r_type)
3294 case elfcpp::R_X86_64_64:
3295 case elfcpp::R_X86_64_32:
3296 case elfcpp::R_X86_64_32S:
3297 case elfcpp::R_X86_64_16:
3298 case elfcpp::R_X86_64_8:
3299 case elfcpp::R_X86_64_GOT64:
3300 case elfcpp::R_X86_64_GOT32:
3301 case elfcpp::R_X86_64_GOTPCREL64:
3302 case elfcpp::R_X86_64_GOTPCREL:
3303 case elfcpp::R_X86_64_GOTPCRELX:
3304 case elfcpp::R_X86_64_REX_GOTPCRELX:
3305 case elfcpp::R_X86_64_GOTPLT64:
3307 return true;
3309 case elfcpp::R_X86_64_PC32:
3311 // This relocation may be used both for function calls and
3312 // for taking address of a function. We distinguish between
3313 // them by checking the opcodes.
3314 uint64_t sh_flags = src_obj->section_flags(src_indx);
3315 bool is_executable = (sh_flags & elfcpp::SHF_EXECINSTR) != 0;
3316 if (is_executable)
3318 section_size_type stype;
3319 const unsigned char* view = src_obj->section_contents(src_indx,
3320 &stype,
3321 true);
3323 // call
3324 if (r_offset >= 1
3325 && view[r_offset - 1] == 0xe8)
3326 return false;
3328 // jmp
3329 if (r_offset >= 1
3330 && view[r_offset - 1] == 0xe9)
3331 return false;
3333 // jo/jno/jb/jnb/je/jne/jna/ja/js/jns/jp/jnp/jl/jge/jle/jg
3334 if (r_offset >= 2
3335 && view[r_offset - 2] == 0x0f
3336 && view[r_offset - 1] >= 0x80
3337 && view[r_offset - 1] <= 0x8f)
3338 return false;
3341 // Be conservative and treat all others as function pointers.
3342 return true;
3345 return false;
3348 // For safe ICF, scan a relocation for a local symbol to check if it
3349 // corresponds to a function pointer being taken. In that case mark
3350 // the function whose pointer was taken as not foldable.
3352 template<int size>
3353 inline bool
3354 Target_x86_64<size>::Scan::local_reloc_may_be_function_pointer(
3355 Symbol_table* ,
3356 Layout* ,
3357 Target_x86_64<size>* ,
3358 Sized_relobj_file<size, false>* src_obj,
3359 unsigned int src_indx,
3360 Output_section* ,
3361 const elfcpp::Rela<size, false>& reloc,
3362 unsigned int r_type,
3363 const elfcpp::Sym<size, false>&)
3365 // When building a shared library, do not fold any local symbols as it is
3366 // not possible to distinguish pointer taken versus a call by looking at
3367 // the relocation types.
3368 if (parameters->options().shared())
3369 return true;
3371 return possible_function_pointer_reloc(src_obj, src_indx,
3372 reloc.get_r_offset(), r_type);
3375 // For safe ICF, scan a relocation for a global symbol to check if it
3376 // corresponds to a function pointer being taken. In that case mark
3377 // the function whose pointer was taken as not foldable.
3379 template<int size>
3380 inline bool
3381 Target_x86_64<size>::Scan::global_reloc_may_be_function_pointer(
3382 Symbol_table*,
3383 Layout* ,
3384 Target_x86_64<size>* ,
3385 Sized_relobj_file<size, false>* src_obj,
3386 unsigned int src_indx,
3387 Output_section* ,
3388 const elfcpp::Rela<size, false>& reloc,
3389 unsigned int r_type,
3390 Symbol* gsym)
3392 // When building a shared library, do not fold symbols whose visibility
3393 // is hidden, internal or protected.
3394 if (parameters->options().shared()
3395 && (gsym->visibility() == elfcpp::STV_INTERNAL
3396 || gsym->visibility() == elfcpp::STV_PROTECTED
3397 || gsym->visibility() == elfcpp::STV_HIDDEN))
3398 return true;
3400 return possible_function_pointer_reloc(src_obj, src_indx,
3401 reloc.get_r_offset(), r_type);
3404 // Scan a relocation for a global symbol.
3406 template<int size>
3407 inline void
3408 Target_x86_64<size>::Scan::global(Symbol_table* symtab,
3409 Layout* layout,
3410 Target_x86_64<size>* target,
3411 Sized_relobj_file<size, false>* object,
3412 unsigned int data_shndx,
3413 Output_section* output_section,
3414 const elfcpp::Rela<size, false>& reloc,
3415 unsigned int r_type,
3416 Symbol* gsym)
3418 // A STT_GNU_IFUNC symbol may require a PLT entry.
3419 if (gsym->type() == elfcpp::STT_GNU_IFUNC
3420 && this->reloc_needs_plt_for_ifunc(object, r_type))
3421 target->make_plt_entry(symtab, layout, gsym);
3423 switch (r_type)
3425 case elfcpp::R_X86_64_NONE:
3426 case elfcpp::R_X86_64_GNU_VTINHERIT:
3427 case elfcpp::R_X86_64_GNU_VTENTRY:
3428 break;
3430 case elfcpp::R_X86_64_64:
3431 case elfcpp::R_X86_64_32:
3432 case elfcpp::R_X86_64_32S:
3433 case elfcpp::R_X86_64_16:
3434 case elfcpp::R_X86_64_8:
3436 // Make a PLT entry if necessary.
3437 if (gsym->needs_plt_entry())
3439 target->make_plt_entry(symtab, layout, gsym);
3440 // Since this is not a PC-relative relocation, we may be
3441 // taking the address of a function. In that case we need to
3442 // set the entry in the dynamic symbol table to the address of
3443 // the PLT entry.
3444 if (gsym->is_from_dynobj() && !parameters->options().shared())
3445 gsym->set_needs_dynsym_value();
3447 // Make a dynamic relocation if necessary.
3448 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
3450 if (!parameters->options().output_is_position_independent()
3451 && gsym->may_need_copy_reloc())
3453 target->copy_reloc(symtab, layout, object,
3454 data_shndx, output_section, gsym, reloc);
3456 else if (((size == 64 && r_type == elfcpp::R_X86_64_64)
3457 || (size == 32 && r_type == elfcpp::R_X86_64_32))
3458 && gsym->type() == elfcpp::STT_GNU_IFUNC
3459 && gsym->can_use_relative_reloc(false)
3460 && !gsym->is_from_dynobj()
3461 && !gsym->is_undefined()
3462 && !gsym->is_preemptible())
3464 // Use an IRELATIVE reloc for a locally defined
3465 // STT_GNU_IFUNC symbol. This makes a function
3466 // address in a PIE executable match the address in a
3467 // shared library that it links against.
3468 Reloc_section* rela_dyn =
3469 target->rela_irelative_section(layout);
3470 unsigned int r_type = elfcpp::R_X86_64_IRELATIVE;
3471 rela_dyn->add_symbolless_global_addend(gsym, r_type,
3472 output_section, object,
3473 data_shndx,
3474 reloc.get_r_offset(),
3475 reloc.get_r_addend());
3477 else if (((size == 64 && r_type == elfcpp::R_X86_64_64)
3478 || (size == 32 && r_type == elfcpp::R_X86_64_32))
3479 && gsym->can_use_relative_reloc(false))
3481 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
3482 rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_RELATIVE,
3483 output_section, object,
3484 data_shndx,
3485 reloc.get_r_offset(),
3486 reloc.get_r_addend(), false);
3488 else
3490 this->check_non_pic(object, r_type, gsym);
3491 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
3492 rela_dyn->add_global(gsym, r_type, output_section, object,
3493 data_shndx, reloc.get_r_offset(),
3494 reloc.get_r_addend());
3498 break;
3500 case elfcpp::R_X86_64_PC64:
3501 case elfcpp::R_X86_64_PC32:
3502 case elfcpp::R_X86_64_PC32_BND:
3503 case elfcpp::R_X86_64_PC16:
3504 case elfcpp::R_X86_64_PC8:
3506 // Make a PLT entry if necessary.
3507 if (gsym->needs_plt_entry())
3508 target->make_plt_entry(symtab, layout, gsym);
3509 // Make a dynamic relocation if necessary.
3510 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
3512 if (parameters->options().output_is_executable()
3513 && gsym->may_need_copy_reloc())
3515 target->copy_reloc(symtab, layout, object,
3516 data_shndx, output_section, gsym, reloc);
3518 else
3520 this->check_non_pic(object, r_type, gsym);
3521 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
3522 rela_dyn->add_global(gsym, r_type, output_section, object,
3523 data_shndx, reloc.get_r_offset(),
3524 reloc.get_r_addend());
3528 break;
3530 case elfcpp::R_X86_64_GOT64:
3531 case elfcpp::R_X86_64_GOT32:
3532 case elfcpp::R_X86_64_GOTPCREL64:
3533 case elfcpp::R_X86_64_GOTPCREL:
3534 case elfcpp::R_X86_64_GOTPCRELX:
3535 case elfcpp::R_X86_64_REX_GOTPCRELX:
3536 case elfcpp::R_X86_64_GOTPLT64:
3538 // The symbol requires a GOT entry.
3539 Output_data_got<64, false>* got = target->got_section(symtab, layout);
3541 // If we convert this from
3542 // mov foo@GOTPCREL(%rip), %reg
3543 // to lea foo(%rip), %reg.
3544 // OR
3545 // if we convert
3546 // (callq|jmpq) *foo@GOTPCRELX(%rip) to
3547 // (callq|jmpq) foo
3548 // in Relocate::relocate, then there is nothing to do here.
3550 Lazy_view<size> view(object, data_shndx);
3551 size_t r_offset = reloc.get_r_offset();
3552 if (r_offset >= 2
3553 && Target_x86_64<size>::can_convert_mov_to_lea(gsym, r_type,
3554 r_offset, &view))
3555 break;
3557 if (r_offset >= 2
3558 && Target_x86_64<size>::can_convert_callq_to_direct(gsym, r_type,
3559 r_offset,
3560 &view))
3561 break;
3563 if (gsym->final_value_is_known())
3565 // For a STT_GNU_IFUNC symbol we want the PLT address.
3566 if (gsym->type() == elfcpp::STT_GNU_IFUNC)
3567 got->add_global_plt(gsym, GOT_TYPE_STANDARD);
3568 else
3569 got->add_global(gsym, GOT_TYPE_STANDARD);
3571 else
3573 // If this symbol is not fully resolved, we need to add a
3574 // dynamic relocation for it.
3575 Reloc_section* rela_dyn = target->rela_dyn_section(layout);
3577 // Use a GLOB_DAT rather than a RELATIVE reloc if:
3579 // 1) The symbol may be defined in some other module.
3581 // 2) We are building a shared library and this is a
3582 // protected symbol; using GLOB_DAT means that the dynamic
3583 // linker can use the address of the PLT in the main
3584 // executable when appropriate so that function address
3585 // comparisons work.
3587 // 3) This is a STT_GNU_IFUNC symbol in position dependent
3588 // code, again so that function address comparisons work.
3589 if (gsym->is_from_dynobj()
3590 || gsym->is_undefined()
3591 || gsym->is_preemptible()
3592 || (gsym->visibility() == elfcpp::STV_PROTECTED
3593 && parameters->options().shared())
3594 || (gsym->type() == elfcpp::STT_GNU_IFUNC
3595 && parameters->options().output_is_position_independent()))
3596 got->add_global_with_rel(gsym, GOT_TYPE_STANDARD, rela_dyn,
3597 elfcpp::R_X86_64_GLOB_DAT);
3598 else
3600 // For a STT_GNU_IFUNC symbol we want to write the PLT
3601 // offset into the GOT, so that function pointer
3602 // comparisons work correctly.
3603 bool is_new;
3604 if (gsym->type() != elfcpp::STT_GNU_IFUNC)
3605 is_new = got->add_global(gsym, GOT_TYPE_STANDARD);
3606 else
3608 is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD);
3609 // Tell the dynamic linker to use the PLT address
3610 // when resolving relocations.
3611 if (gsym->is_from_dynobj()
3612 && !parameters->options().shared())
3613 gsym->set_needs_dynsym_value();
3615 if (is_new)
3617 unsigned int got_off = gsym->got_offset(GOT_TYPE_STANDARD);
3618 rela_dyn->add_global_relative(gsym,
3619 elfcpp::R_X86_64_RELATIVE,
3620 got, got_off, 0, false);
3625 break;
3627 case elfcpp::R_X86_64_PLT32:
3628 case elfcpp::R_X86_64_PLT32_BND:
3629 // If the symbol is fully resolved, this is just a PC32 reloc.
3630 // Otherwise we need a PLT entry.
3631 if (gsym->final_value_is_known())
3632 break;
3633 // If building a shared library, we can also skip the PLT entry
3634 // if the symbol is defined in the output file and is protected
3635 // or hidden.
3636 if (gsym->is_defined()
3637 && !gsym->is_from_dynobj()
3638 && !gsym->is_preemptible())
3639 break;
3640 target->make_plt_entry(symtab, layout, gsym);
3641 break;
3643 case elfcpp::R_X86_64_GOTPC32:
3644 case elfcpp::R_X86_64_GOTOFF64:
3645 case elfcpp::R_X86_64_GOTPC64:
3646 case elfcpp::R_X86_64_PLTOFF64:
3647 // We need a GOT section.
3648 target->got_section(symtab, layout);
3649 // For PLTOFF64, we also need a PLT entry (but only if the
3650 // symbol is not fully resolved).
3651 if (r_type == elfcpp::R_X86_64_PLTOFF64
3652 && !gsym->final_value_is_known())
3653 target->make_plt_entry(symtab, layout, gsym);
3654 break;
3656 case elfcpp::R_X86_64_COPY:
3657 case elfcpp::R_X86_64_GLOB_DAT:
3658 case elfcpp::R_X86_64_JUMP_SLOT:
3659 case elfcpp::R_X86_64_RELATIVE:
3660 case elfcpp::R_X86_64_IRELATIVE:
3661 // These are outstanding tls relocs, which are unexpected when linking
3662 case elfcpp::R_X86_64_TPOFF64:
3663 case elfcpp::R_X86_64_DTPMOD64:
3664 case elfcpp::R_X86_64_TLSDESC:
3665 gold_error(_("%s: unexpected reloc %u in object file"),
3666 object->name().c_str(), r_type);
3667 break;
3669 // These are initial tls relocs, which are expected for global()
3670 case elfcpp::R_X86_64_TLSGD: // Global-dynamic
3671 case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
3672 case elfcpp::R_X86_64_TLSDESC_CALL:
3673 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
3674 case elfcpp::R_X86_64_DTPOFF32:
3675 case elfcpp::R_X86_64_DTPOFF64:
3676 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
3677 case elfcpp::R_X86_64_TPOFF32: // Local-exec
3679 // For the Initial-Exec model, we can treat undef symbols as final
3680 // when building an executable.
3681 const bool is_final = (gsym->final_value_is_known() ||
3682 (r_type == elfcpp::R_X86_64_GOTTPOFF &&
3683 gsym->is_undefined() &&
3684 parameters->options().output_is_executable()));
3685 const tls::Tls_optimization optimized_type
3686 = Target_x86_64<size>::optimize_tls_reloc(is_final, r_type);
3687 switch (r_type)
3689 case elfcpp::R_X86_64_TLSGD: // General-dynamic
3690 if (optimized_type == tls::TLSOPT_NONE)
3692 // Create a pair of GOT entries for the module index and
3693 // dtv-relative offset.
3694 Output_data_got<64, false>* got
3695 = target->got_section(symtab, layout);
3696 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
3697 target->rela_dyn_section(layout),
3698 elfcpp::R_X86_64_DTPMOD64,
3699 elfcpp::R_X86_64_DTPOFF64);
3701 else if (optimized_type == tls::TLSOPT_TO_IE)
3703 // Create a GOT entry for the tp-relative offset.
3704 Output_data_got<64, false>* got
3705 = target->got_section(symtab, layout);
3706 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
3707 target->rela_dyn_section(layout),
3708 elfcpp::R_X86_64_TPOFF64);
3710 else if (optimized_type != tls::TLSOPT_TO_LE)
3711 unsupported_reloc_global(object, r_type, gsym);
3712 break;
3714 case elfcpp::R_X86_64_GOTPC32_TLSDESC:
3715 target->define_tls_base_symbol(symtab, layout);
3716 if (optimized_type == tls::TLSOPT_NONE)
3718 // Create reserved PLT and GOT entries for the resolver.
3719 target->reserve_tlsdesc_entries(symtab, layout);
3721 // Create a double GOT entry with an R_X86_64_TLSDESC
3722 // reloc. The R_X86_64_TLSDESC reloc is resolved
3723 // lazily, so the GOT entry needs to be in an area in
3724 // .got.plt, not .got. Call got_section to make sure
3725 // the section has been created.
3726 target->got_section(symtab, layout);
3727 Output_data_got<64, false>* got = target->got_tlsdesc_section();
3728 Reloc_section* rt = target->rela_tlsdesc_section(layout);
3729 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC, rt,
3730 elfcpp::R_X86_64_TLSDESC, 0);
3732 else if (optimized_type == tls::TLSOPT_TO_IE)
3734 // Create a GOT entry for the tp-relative offset.
3735 Output_data_got<64, false>* got
3736 = target->got_section(symtab, layout);
3737 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
3738 target->rela_dyn_section(layout),
3739 elfcpp::R_X86_64_TPOFF64);
3741 else if (optimized_type != tls::TLSOPT_TO_LE)
3742 unsupported_reloc_global(object, r_type, gsym);
3743 break;
3745 case elfcpp::R_X86_64_TLSDESC_CALL:
3746 break;
3748 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
3749 if (optimized_type == tls::TLSOPT_NONE)
3751 // Create a GOT entry for the module index.
3752 target->got_mod_index_entry(symtab, layout, object);
3754 else if (optimized_type != tls::TLSOPT_TO_LE)
3755 unsupported_reloc_global(object, r_type, gsym);
3756 break;
3758 case elfcpp::R_X86_64_DTPOFF32:
3759 case elfcpp::R_X86_64_DTPOFF64:
3760 break;
3762 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
3763 layout->set_has_static_tls();
3764 if (optimized_type == tls::TLSOPT_NONE)
3766 // Create a GOT entry for the tp-relative offset.
3767 Output_data_got<64, false>* got
3768 = target->got_section(symtab, layout);
3769 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
3770 target->rela_dyn_section(layout),
3771 elfcpp::R_X86_64_TPOFF64);
3773 else if (optimized_type != tls::TLSOPT_TO_LE)
3774 unsupported_reloc_global(object, r_type, gsym);
3775 break;
3777 case elfcpp::R_X86_64_TPOFF32: // Local-exec
3778 layout->set_has_static_tls();
3779 if (parameters->options().shared())
3780 unsupported_reloc_global(object, r_type, gsym);
3781 break;
3783 default:
3784 gold_unreachable();
3787 break;
3789 case elfcpp::R_X86_64_SIZE32:
3790 case elfcpp::R_X86_64_SIZE64:
3791 default:
3792 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
3793 object->name().c_str(), r_type,
3794 gsym->demangled_name().c_str());
3795 break;
3799 template<int size>
3800 void
3801 Target_x86_64<size>::gc_process_relocs(Symbol_table* symtab,
3802 Layout* layout,
3803 Sized_relobj_file<size, false>* object,
3804 unsigned int data_shndx,
3805 unsigned int sh_type,
3806 const unsigned char* prelocs,
3807 size_t reloc_count,
3808 Output_section* output_section,
3809 bool needs_special_offset_handling,
3810 size_t local_symbol_count,
3811 const unsigned char* plocal_symbols)
3813 typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
3814 Classify_reloc;
3816 if (sh_type == elfcpp::SHT_REL)
3818 return;
3821 gold::gc_process_relocs<size, false, Target_x86_64<size>, Scan,
3822 Classify_reloc>(
3823 symtab,
3824 layout,
3825 this,
3826 object,
3827 data_shndx,
3828 prelocs,
3829 reloc_count,
3830 output_section,
3831 needs_special_offset_handling,
3832 local_symbol_count,
3833 plocal_symbols);
3836 // Scan relocations for a section.
3838 template<int size>
3839 void
3840 Target_x86_64<size>::scan_relocs(Symbol_table* symtab,
3841 Layout* layout,
3842 Sized_relobj_file<size, false>* object,
3843 unsigned int data_shndx,
3844 unsigned int sh_type,
3845 const unsigned char* prelocs,
3846 size_t reloc_count,
3847 Output_section* output_section,
3848 bool needs_special_offset_handling,
3849 size_t local_symbol_count,
3850 const unsigned char* plocal_symbols)
3852 typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
3853 Classify_reloc;
3855 if (sh_type == elfcpp::SHT_REL)
3857 gold_error(_("%s: unsupported REL reloc section"),
3858 object->name().c_str());
3859 return;
3862 gold::scan_relocs<size, false, Target_x86_64<size>, Scan, Classify_reloc>(
3863 symtab,
3864 layout,
3865 this,
3866 object,
3867 data_shndx,
3868 prelocs,
3869 reloc_count,
3870 output_section,
3871 needs_special_offset_handling,
3872 local_symbol_count,
3873 plocal_symbols);
3876 // Finalize the sections.
3878 template<int size>
3879 void
3880 Target_x86_64<size>::do_finalize_sections(
3881 Layout* layout,
3882 const Input_objects*,
3883 Symbol_table* symtab)
3885 const Reloc_section* rel_plt = (this->plt_ == NULL
3886 ? NULL
3887 : this->plt_->rela_plt());
3888 layout->add_target_dynamic_tags(false, this->got_plt_, rel_plt,
3889 this->rela_dyn_, true, false);
3891 // Fill in some more dynamic tags.
3892 Output_data_dynamic* const odyn = layout->dynamic_data();
3893 if (odyn != NULL)
3895 if (this->plt_ != NULL
3896 && this->plt_->output_section() != NULL
3897 && this->plt_->has_tlsdesc_entry())
3899 unsigned int plt_offset = this->plt_->get_tlsdesc_plt_offset();
3900 unsigned int got_offset = this->plt_->get_tlsdesc_got_offset();
3901 this->got_->finalize_data_size();
3902 odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_PLT,
3903 this->plt_, plt_offset);
3904 odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_GOT,
3905 this->got_, got_offset);
3909 // Emit any relocs we saved in an attempt to avoid generating COPY
3910 // relocs.
3911 if (this->copy_relocs_.any_saved_relocs())
3912 this->copy_relocs_.emit(this->rela_dyn_section(layout));
3914 // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of
3915 // the .got.plt section.
3916 Symbol* sym = this->global_offset_table_;
3917 if (sym != NULL)
3919 uint64_t data_size = this->got_plt_->current_data_size();
3920 symtab->get_sized_symbol<size>(sym)->set_symsize(data_size);
3923 if (parameters->doing_static_link()
3924 && (this->plt_ == NULL || !this->plt_->has_irelative_section()))
3926 // If linking statically, make sure that the __rela_iplt symbols
3927 // were defined if necessary, even if we didn't create a PLT.
3928 static const Define_symbol_in_segment syms[] =
3931 "__rela_iplt_start", // name
3932 elfcpp::PT_LOAD, // segment_type
3933 elfcpp::PF_W, // segment_flags_set
3934 elfcpp::PF(0), // segment_flags_clear
3935 0, // value
3936 0, // size
3937 elfcpp::STT_NOTYPE, // type
3938 elfcpp::STB_GLOBAL, // binding
3939 elfcpp::STV_HIDDEN, // visibility
3940 0, // nonvis
3941 Symbol::SEGMENT_START, // offset_from_base
3942 true // only_if_ref
3945 "__rela_iplt_end", // name
3946 elfcpp::PT_LOAD, // segment_type
3947 elfcpp::PF_W, // segment_flags_set
3948 elfcpp::PF(0), // segment_flags_clear
3949 0, // value
3950 0, // size
3951 elfcpp::STT_NOTYPE, // type
3952 elfcpp::STB_GLOBAL, // binding
3953 elfcpp::STV_HIDDEN, // visibility
3954 0, // nonvis
3955 Symbol::SEGMENT_START, // offset_from_base
3956 true // only_if_ref
3960 symtab->define_symbols(layout, 2, syms,
3961 layout->script_options()->saw_sections_clause());
3965 // For x32, we need to handle PC-relative relocations using full 64-bit
3966 // arithmetic, so that we can detect relocation overflows properly.
3967 // This class overrides the pcrela32_check methods from the defaults in
3968 // Relocate_functions in reloc.h.
3970 template<int size>
3971 class X86_64_relocate_functions : public Relocate_functions<size, false>
3973 public:
3974 typedef Relocate_functions<size, false> Base;
3976 // Do a simple PC relative relocation with the addend in the
3977 // relocation.
3978 static inline typename Base::Reloc_status
3979 pcrela32_check(unsigned char* view,
3980 typename elfcpp::Elf_types<64>::Elf_Addr value,
3981 typename elfcpp::Elf_types<64>::Elf_Swxword addend,
3982 typename elfcpp::Elf_types<64>::Elf_Addr address)
3984 typedef typename elfcpp::Swap<32, false>::Valtype Valtype;
3985 Valtype* wv = reinterpret_cast<Valtype*>(view);
3986 value = value + addend - address;
3987 elfcpp::Swap<32, false>::writeval(wv, value);
3988 return (Bits<32>::has_overflow(value)
3989 ? Base::RELOC_OVERFLOW : Base::RELOC_OK);
3992 // Do a simple PC relative relocation with a Symbol_value with the
3993 // addend in the relocation.
3994 static inline typename Base::Reloc_status
3995 pcrela32_check(unsigned char* view,
3996 const Sized_relobj_file<size, false>* object,
3997 const Symbol_value<size>* psymval,
3998 typename elfcpp::Elf_types<64>::Elf_Swxword addend,
3999 typename elfcpp::Elf_types<64>::Elf_Addr address)
4001 typedef typename elfcpp::Swap<32, false>::Valtype Valtype;
4002 Valtype* wv = reinterpret_cast<Valtype*>(view);
4003 typename elfcpp::Elf_types<64>::Elf_Addr value;
4004 if (addend >= 0)
4005 value = psymval->value(object, addend);
4006 else
4008 // For negative addends, get the symbol value without
4009 // the addend, then add the addend using 64-bit arithmetic.
4010 value = psymval->value(object, 0);
4011 value += addend;
4013 value -= address;
4014 elfcpp::Swap<32, false>::writeval(wv, value);
4015 return (Bits<32>::has_overflow(value)
4016 ? Base::RELOC_OVERFLOW : Base::RELOC_OK);
4020 // Perform a relocation.
4022 template<int size>
4023 inline bool
4024 Target_x86_64<size>::Relocate::relocate(
4025 const Relocate_info<size, false>* relinfo,
4026 unsigned int,
4027 Target_x86_64<size>* target,
4028 Output_section*,
4029 size_t relnum,
4030 const unsigned char* preloc,
4031 const Sized_symbol<size>* gsym,
4032 const Symbol_value<size>* psymval,
4033 unsigned char* view,
4034 typename elfcpp::Elf_types<size>::Elf_Addr address,
4035 section_size_type view_size)
4037 typedef X86_64_relocate_functions<size> Reloc_funcs;
4038 const elfcpp::Rela<size, false> rela(preloc);
4039 unsigned int r_type = elfcpp::elf_r_type<size>(rela.get_r_info());
4041 if (this->skip_call_tls_get_addr_)
4043 if ((r_type != elfcpp::R_X86_64_PLT32
4044 && r_type != elfcpp::R_X86_64_GOTPCREL
4045 && r_type != elfcpp::R_X86_64_GOTPCRELX
4046 && r_type != elfcpp::R_X86_64_PLT32_BND
4047 && r_type != elfcpp::R_X86_64_PC32_BND
4048 && r_type != elfcpp::R_X86_64_PC32)
4049 || gsym == NULL
4050 || strcmp(gsym->name(), "__tls_get_addr") != 0)
4052 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
4053 _("missing expected TLS relocation"));
4054 this->skip_call_tls_get_addr_ = false;
4056 else
4058 this->skip_call_tls_get_addr_ = false;
4059 return false;
4063 if (view == NULL)
4064 return true;
4066 const Sized_relobj_file<size, false>* object = relinfo->object;
4068 // Pick the value to use for symbols defined in the PLT.
4069 Symbol_value<size> symval;
4070 if (gsym != NULL
4071 && gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
4073 symval.set_output_value(target->plt_address_for_global(gsym));
4074 psymval = &symval;
4076 else if (gsym == NULL && psymval->is_ifunc_symbol())
4078 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
4079 if (object->local_has_plt_offset(r_sym))
4081 symval.set_output_value(target->plt_address_for_local(object, r_sym));
4082 psymval = &symval;
4086 const elfcpp::Elf_Xword addend = rela.get_r_addend();
4088 // Get the GOT offset if needed.
4089 // The GOT pointer points to the end of the GOT section.
4090 // We need to subtract the size of the GOT section to get
4091 // the actual offset to use in the relocation.
4092 bool have_got_offset = false;
4093 // Since the actual offset is always negative, we use signed int to
4094 // support 64-bit GOT relocations.
4095 int got_offset = 0;
4096 switch (r_type)
4098 case elfcpp::R_X86_64_GOT32:
4099 case elfcpp::R_X86_64_GOT64:
4100 case elfcpp::R_X86_64_GOTPLT64:
4101 case elfcpp::R_X86_64_GOTPCREL64:
4102 if (gsym != NULL)
4104 gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
4105 got_offset = gsym->got_offset(GOT_TYPE_STANDARD) - target->got_size();
4107 else
4109 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
4110 gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
4111 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
4112 - target->got_size());
4114 have_got_offset = true;
4115 break;
4117 default:
4118 break;
4121 typename Reloc_funcs::Reloc_status rstatus = Reloc_funcs::RELOC_OK;
4123 switch (r_type)
4125 case elfcpp::R_X86_64_NONE:
4126 case elfcpp::R_X86_64_GNU_VTINHERIT:
4127 case elfcpp::R_X86_64_GNU_VTENTRY:
4128 break;
4130 case elfcpp::R_X86_64_64:
4131 Reloc_funcs::rela64(view, object, psymval, addend);
4132 break;
4134 case elfcpp::R_X86_64_PC64:
4135 Reloc_funcs::pcrela64(view, object, psymval, addend,
4136 address);
4137 break;
4139 case elfcpp::R_X86_64_32:
4140 rstatus = Reloc_funcs::rela32_check(view, object, psymval, addend,
4141 Reloc_funcs::CHECK_UNSIGNED);
4142 break;
4144 case elfcpp::R_X86_64_32S:
4145 rstatus = Reloc_funcs::rela32_check(view, object, psymval, addend,
4146 Reloc_funcs::CHECK_SIGNED);
4147 break;
4149 case elfcpp::R_X86_64_PC32:
4150 case elfcpp::R_X86_64_PC32_BND:
4151 rstatus = Reloc_funcs::pcrela32_check(view, object, psymval, addend,
4152 address);
4153 break;
4155 case elfcpp::R_X86_64_16:
4156 Reloc_funcs::rela16(view, object, psymval, addend);
4157 break;
4159 case elfcpp::R_X86_64_PC16:
4160 Reloc_funcs::pcrela16(view, object, psymval, addend, address);
4161 break;
4163 case elfcpp::R_X86_64_8:
4164 Reloc_funcs::rela8(view, object, psymval, addend);
4165 break;
4167 case elfcpp::R_X86_64_PC8:
4168 Reloc_funcs::pcrela8(view, object, psymval, addend, address);
4169 break;
4171 case elfcpp::R_X86_64_PLT32:
4172 case elfcpp::R_X86_64_PLT32_BND:
4173 gold_assert(gsym == NULL
4174 || gsym->has_plt_offset()
4175 || gsym->final_value_is_known()
4176 || (gsym->is_defined()
4177 && !gsym->is_from_dynobj()
4178 && !gsym->is_preemptible()));
4179 // Note: while this code looks the same as for R_X86_64_PC32, it
4180 // behaves differently because psymval was set to point to
4181 // the PLT entry, rather than the symbol, in Scan::global().
4182 rstatus = Reloc_funcs::pcrela32_check(view, object, psymval, addend,
4183 address);
4184 break;
4186 case elfcpp::R_X86_64_PLTOFF64:
4188 gold_assert(gsym);
4189 gold_assert(gsym->has_plt_offset()
4190 || gsym->final_value_is_known());
4191 typename elfcpp::Elf_types<size>::Elf_Addr got_address;
4192 // This is the address of GLOBAL_OFFSET_TABLE.
4193 got_address = target->got_plt_section()->address();
4194 Reloc_funcs::rela64(view, object, psymval, addend - got_address);
4196 break;
4198 case elfcpp::R_X86_64_GOT32:
4199 gold_assert(have_got_offset);
4200 Reloc_funcs::rela32(view, got_offset, addend);
4201 break;
4203 case elfcpp::R_X86_64_GOTPC32:
4205 gold_assert(gsym);
4206 typename elfcpp::Elf_types<size>::Elf_Addr value;
4207 value = target->got_plt_section()->address();
4208 Reloc_funcs::pcrela32_check(view, value, addend, address);
4210 break;
4212 case elfcpp::R_X86_64_GOT64:
4213 case elfcpp::R_X86_64_GOTPLT64:
4214 // R_X86_64_GOTPLT64 is obsolete and treated the same as
4215 // GOT64.
4216 gold_assert(have_got_offset);
4217 Reloc_funcs::rela64(view, got_offset, addend);
4218 break;
4220 case elfcpp::R_X86_64_GOTPC64:
4222 gold_assert(gsym);
4223 typename elfcpp::Elf_types<size>::Elf_Addr value;
4224 value = target->got_plt_section()->address();
4225 Reloc_funcs::pcrela64(view, value, addend, address);
4227 break;
4229 case elfcpp::R_X86_64_GOTOFF64:
4231 typename elfcpp::Elf_types<size>::Elf_Addr value;
4232 value = (psymval->value(object, 0)
4233 - target->got_plt_section()->address());
4234 Reloc_funcs::rela64(view, value, addend);
4236 break;
4238 case elfcpp::R_X86_64_GOTPCREL:
4239 case elfcpp::R_X86_64_GOTPCRELX:
4240 case elfcpp::R_X86_64_REX_GOTPCRELX:
4242 // Convert
4243 // mov foo@GOTPCREL(%rip), %reg
4244 // to lea foo(%rip), %reg.
4245 // if possible.
4246 if ((gsym == NULL
4247 && rela.get_r_offset() >= 2
4248 && view[-2] == 0x8b
4249 && !psymval->is_ifunc_symbol())
4250 || (gsym != NULL
4251 && rela.get_r_offset() >= 2
4252 && Target_x86_64<size>::can_convert_mov_to_lea(gsym, r_type,
4253 0, &view)))
4255 view[-2] = 0x8d;
4256 Reloc_funcs::pcrela32(view, object, psymval, addend, address);
4258 // Convert
4259 // callq *foo@GOTPCRELX(%rip) to
4260 // addr32 callq foo
4261 // and jmpq *foo@GOTPCRELX(%rip) to
4262 // jmpq foo
4263 // nop
4264 else if (gsym != NULL
4265 && rela.get_r_offset() >= 2
4266 && Target_x86_64<size>::can_convert_callq_to_direct(gsym,
4267 r_type,
4268 0, &view))
4270 if (view[-1] == 0x15)
4272 // Convert callq *foo@GOTPCRELX(%rip) to addr32 callq.
4273 // Opcode of addr32 is 0x67 and opcode of direct callq is 0xe8.
4274 view[-2] = 0x67;
4275 view[-1] = 0xe8;
4276 // Convert GOTPCRELX to 32-bit pc relative reloc.
4277 Reloc_funcs::pcrela32(view, object, psymval, addend, address);
4279 else
4281 // Convert jmpq *foo@GOTPCRELX(%rip) to
4282 // jmpq foo
4283 // nop
4284 // The opcode of direct jmpq is 0xe9.
4285 view[-2] = 0xe9;
4286 // The opcode of nop is 0x90.
4287 view[3] = 0x90;
4288 // Convert GOTPCRELX to 32-bit pc relative reloc. jmpq is rip
4289 // relative and since the instruction following the jmpq is now
4290 // the nop, offset the address by 1 byte. The start of the
4291 // relocation also moves ahead by 1 byte.
4292 Reloc_funcs::pcrela32(&view[-1], object, psymval, addend,
4293 address - 1);
4296 else
4298 if (gsym != NULL)
4300 gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
4301 got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
4302 - target->got_size());
4304 else
4306 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
4307 gold_assert(object->local_has_got_offset(r_sym,
4308 GOT_TYPE_STANDARD));
4309 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
4310 - target->got_size());
4312 typename elfcpp::Elf_types<size>::Elf_Addr value;
4313 value = target->got_plt_section()->address() + got_offset;
4314 Reloc_funcs::pcrela32_check(view, value, addend, address);
4317 break;
4319 case elfcpp::R_X86_64_GOTPCREL64:
4321 gold_assert(have_got_offset);
4322 typename elfcpp::Elf_types<size>::Elf_Addr value;
4323 value = target->got_plt_section()->address() + got_offset;
4324 Reloc_funcs::pcrela64(view, value, addend, address);
4326 break;
4328 case elfcpp::R_X86_64_COPY:
4329 case elfcpp::R_X86_64_GLOB_DAT:
4330 case elfcpp::R_X86_64_JUMP_SLOT:
4331 case elfcpp::R_X86_64_RELATIVE:
4332 case elfcpp::R_X86_64_IRELATIVE:
4333 // These are outstanding tls relocs, which are unexpected when linking
4334 case elfcpp::R_X86_64_TPOFF64:
4335 case elfcpp::R_X86_64_DTPMOD64:
4336 case elfcpp::R_X86_64_TLSDESC:
4337 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
4338 _("unexpected reloc %u in object file"),
4339 r_type);
4340 break;
4342 // These are initial tls relocs, which are expected when linking
4343 case elfcpp::R_X86_64_TLSGD: // Global-dynamic
4344 case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
4345 case elfcpp::R_X86_64_TLSDESC_CALL:
4346 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
4347 case elfcpp::R_X86_64_DTPOFF32:
4348 case elfcpp::R_X86_64_DTPOFF64:
4349 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
4350 case elfcpp::R_X86_64_TPOFF32: // Local-exec
4351 this->relocate_tls(relinfo, target, relnum, rela, r_type, gsym, psymval,
4352 view, address, view_size);
4353 break;
4355 case elfcpp::R_X86_64_SIZE32:
4356 case elfcpp::R_X86_64_SIZE64:
4357 default:
4358 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
4359 _("unsupported reloc %u"),
4360 r_type);
4361 break;
4364 if (rstatus == Reloc_funcs::RELOC_OVERFLOW)
4366 if (gsym == NULL)
4368 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
4369 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
4370 _("relocation overflow: "
4371 "reference to local symbol %u in %s"),
4372 r_sym, object->name().c_str());
4374 else if (gsym->is_defined() && gsym->source() == Symbol::FROM_OBJECT)
4376 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
4377 _("relocation overflow: "
4378 "reference to '%s' defined in %s"),
4379 gsym->name(),
4380 gsym->object()->name().c_str());
4382 else
4384 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
4385 _("relocation overflow: reference to '%s'"),
4386 gsym->name());
4390 return true;
4393 // Perform a TLS relocation.
4395 template<int size>
4396 inline void
4397 Target_x86_64<size>::Relocate::relocate_tls(
4398 const Relocate_info<size, false>* relinfo,
4399 Target_x86_64<size>* target,
4400 size_t relnum,
4401 const elfcpp::Rela<size, false>& rela,
4402 unsigned int r_type,
4403 const Sized_symbol<size>* gsym,
4404 const Symbol_value<size>* psymval,
4405 unsigned char* view,
4406 typename elfcpp::Elf_types<size>::Elf_Addr address,
4407 section_size_type view_size)
4409 Output_segment* tls_segment = relinfo->layout->tls_segment();
4411 const Sized_relobj_file<size, false>* object = relinfo->object;
4412 const elfcpp::Elf_Xword addend = rela.get_r_addend();
4413 elfcpp::Shdr<size, false> data_shdr(relinfo->data_shdr);
4414 bool is_executable = (data_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0;
4416 typename elfcpp::Elf_types<size>::Elf_Addr value = psymval->value(relinfo->object, 0);
4418 const bool is_final = (gsym == NULL
4419 ? !parameters->options().shared()
4420 : gsym->final_value_is_known());
4421 tls::Tls_optimization optimized_type
4422 = Target_x86_64<size>::optimize_tls_reloc(is_final, r_type);
4423 switch (r_type)
4425 case elfcpp::R_X86_64_TLSGD: // Global-dynamic
4426 if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
4428 // If this code sequence is used in a non-executable section,
4429 // we will not optimize the R_X86_64_DTPOFF32/64 relocation,
4430 // on the assumption that it's being used by itself in a debug
4431 // section. Therefore, in the unlikely event that the code
4432 // sequence appears in a non-executable section, we simply
4433 // leave it unoptimized.
4434 optimized_type = tls::TLSOPT_NONE;
4436 if (optimized_type == tls::TLSOPT_TO_LE)
4438 if (tls_segment == NULL)
4440 gold_assert(parameters->errors()->error_count() > 0
4441 || issue_undefined_symbol_error(gsym));
4442 return;
4444 this->tls_gd_to_le(relinfo, relnum, tls_segment,
4445 rela, r_type, value, view,
4446 view_size);
4447 break;
4449 else
4451 unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
4452 ? GOT_TYPE_TLS_OFFSET
4453 : GOT_TYPE_TLS_PAIR);
4454 unsigned int got_offset;
4455 if (gsym != NULL)
4457 gold_assert(gsym->has_got_offset(got_type));
4458 got_offset = gsym->got_offset(got_type) - target->got_size();
4460 else
4462 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
4463 gold_assert(object->local_has_got_offset(r_sym, got_type));
4464 got_offset = (object->local_got_offset(r_sym, got_type)
4465 - target->got_size());
4467 if (optimized_type == tls::TLSOPT_TO_IE)
4469 value = target->got_plt_section()->address() + got_offset;
4470 this->tls_gd_to_ie(relinfo, relnum, rela, r_type,
4471 value, view, address, view_size);
4472 break;
4474 else if (optimized_type == tls::TLSOPT_NONE)
4476 // Relocate the field with the offset of the pair of GOT
4477 // entries.
4478 value = target->got_plt_section()->address() + got_offset;
4479 Relocate_functions<size, false>::pcrela32(view, value, addend,
4480 address);
4481 break;
4484 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
4485 _("unsupported reloc %u"), r_type);
4486 break;
4488 case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
4489 case elfcpp::R_X86_64_TLSDESC_CALL:
4490 if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
4492 // See above comment for R_X86_64_TLSGD.
4493 optimized_type = tls::TLSOPT_NONE;
4495 if (optimized_type == tls::TLSOPT_TO_LE)
4497 if (tls_segment == NULL)
4499 gold_assert(parameters->errors()->error_count() > 0
4500 || issue_undefined_symbol_error(gsym));
4501 return;
4503 this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
4504 rela, r_type, value, view,
4505 view_size);
4506 break;
4508 else
4510 unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
4511 ? GOT_TYPE_TLS_OFFSET
4512 : GOT_TYPE_TLS_DESC);
4513 unsigned int got_offset = 0;
4514 if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC
4515 && optimized_type == tls::TLSOPT_NONE)
4517 // We created GOT entries in the .got.tlsdesc portion of
4518 // the .got.plt section, but the offset stored in the
4519 // symbol is the offset within .got.tlsdesc.
4520 got_offset = (target->got_size()
4521 + target->got_plt_section()->data_size());
4523 if (gsym != NULL)
4525 gold_assert(gsym->has_got_offset(got_type));
4526 got_offset += gsym->got_offset(got_type) - target->got_size();
4528 else
4530 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
4531 gold_assert(object->local_has_got_offset(r_sym, got_type));
4532 got_offset += (object->local_got_offset(r_sym, got_type)
4533 - target->got_size());
4535 if (optimized_type == tls::TLSOPT_TO_IE)
4537 value = target->got_plt_section()->address() + got_offset;
4538 this->tls_desc_gd_to_ie(relinfo, relnum,
4539 rela, r_type, value, view, address,
4540 view_size);
4541 break;
4543 else if (optimized_type == tls::TLSOPT_NONE)
4545 if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
4547 // Relocate the field with the offset of the pair of GOT
4548 // entries.
4549 value = target->got_plt_section()->address() + got_offset;
4550 Relocate_functions<size, false>::pcrela32(view, value, addend,
4551 address);
4553 break;
4556 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
4557 _("unsupported reloc %u"), r_type);
4558 break;
4560 case elfcpp::R_X86_64_TLSLD: // Local-dynamic
4561 if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
4563 // See above comment for R_X86_64_TLSGD.
4564 optimized_type = tls::TLSOPT_NONE;
4566 if (optimized_type == tls::TLSOPT_TO_LE)
4568 if (tls_segment == NULL)
4570 gold_assert(parameters->errors()->error_count() > 0
4571 || issue_undefined_symbol_error(gsym));
4572 return;
4574 this->tls_ld_to_le(relinfo, relnum, tls_segment, rela, r_type,
4575 value, view, view_size);
4576 break;
4578 else if (optimized_type == tls::TLSOPT_NONE)
4580 // Relocate the field with the offset of the GOT entry for
4581 // the module index.
4582 unsigned int got_offset;
4583 got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
4584 - target->got_size());
4585 value = target->got_plt_section()->address() + got_offset;
4586 Relocate_functions<size, false>::pcrela32(view, value, addend,
4587 address);
4588 break;
4590 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
4591 _("unsupported reloc %u"), r_type);
4592 break;
4594 case elfcpp::R_X86_64_DTPOFF32:
4595 // This relocation type is used in debugging information.
4596 // In that case we need to not optimize the value. If the
4597 // section is not executable, then we assume we should not
4598 // optimize this reloc. See comments above for R_X86_64_TLSGD,
4599 // R_X86_64_GOTPC32_TLSDESC, R_X86_64_TLSDESC_CALL, and
4600 // R_X86_64_TLSLD.
4601 if (optimized_type == tls::TLSOPT_TO_LE && is_executable)
4603 if (tls_segment == NULL)
4605 gold_assert(parameters->errors()->error_count() > 0
4606 || issue_undefined_symbol_error(gsym));
4607 return;
4609 value -= tls_segment->memsz();
4611 Relocate_functions<size, false>::rela32(view, value, addend);
4612 break;
4614 case elfcpp::R_X86_64_DTPOFF64:
4615 // See R_X86_64_DTPOFF32, just above, for why we check for is_executable.
4616 if (optimized_type == tls::TLSOPT_TO_LE && is_executable)
4618 if (tls_segment == NULL)
4620 gold_assert(parameters->errors()->error_count() > 0
4621 || issue_undefined_symbol_error(gsym));
4622 return;
4624 value -= tls_segment->memsz();
4626 Relocate_functions<size, false>::rela64(view, value, addend);
4627 break;
4629 case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
4630 if (gsym != NULL
4631 && gsym->is_undefined()
4632 && parameters->options().output_is_executable())
4634 Target_x86_64<size>::Relocate::tls_ie_to_le(relinfo, relnum,
4635 NULL, rela,
4636 r_type, value, view,
4637 view_size);
4638 break;
4640 else if (optimized_type == tls::TLSOPT_TO_LE)
4642 if (tls_segment == NULL)
4644 gold_assert(parameters->errors()->error_count() > 0
4645 || issue_undefined_symbol_error(gsym));
4646 return;
4648 Target_x86_64<size>::Relocate::tls_ie_to_le(relinfo, relnum,
4649 tls_segment, rela,
4650 r_type, value, view,
4651 view_size);
4652 break;
4654 else if (optimized_type == tls::TLSOPT_NONE)
4656 // Relocate the field with the offset of the GOT entry for
4657 // the tp-relative offset of the symbol.
4658 unsigned int got_offset;
4659 if (gsym != NULL)
4661 gold_assert(gsym->has_got_offset(GOT_TYPE_TLS_OFFSET));
4662 got_offset = (gsym->got_offset(GOT_TYPE_TLS_OFFSET)
4663 - target->got_size());
4665 else
4667 unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
4668 gold_assert(object->local_has_got_offset(r_sym,
4669 GOT_TYPE_TLS_OFFSET));
4670 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET)
4671 - target->got_size());
4673 value = target->got_plt_section()->address() + got_offset;
4674 Relocate_functions<size, false>::pcrela32(view, value, addend,
4675 address);
4676 break;
4678 gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
4679 _("unsupported reloc type %u"),
4680 r_type);
4681 break;
4683 case elfcpp::R_X86_64_TPOFF32: // Local-exec
4684 if (tls_segment == NULL)
4686 gold_assert(parameters->errors()->error_count() > 0
4687 || issue_undefined_symbol_error(gsym));
4688 return;
4690 value -= tls_segment->memsz();
4691 Relocate_functions<size, false>::rela32(view, value, addend);
4692 break;
4696 // Do a relocation in which we convert a TLS General-Dynamic to an
4697 // Initial-Exec.
4699 template<int size>
4700 inline void
4701 Target_x86_64<size>::Relocate::tls_gd_to_ie(
4702 const Relocate_info<size, false>* relinfo,
4703 size_t relnum,
4704 const elfcpp::Rela<size, false>& rela,
4705 unsigned int,
4706 typename elfcpp::Elf_types<size>::Elf_Addr value,
4707 unsigned char* view,
4708 typename elfcpp::Elf_types<size>::Elf_Addr address,
4709 section_size_type view_size)
4711 // For SIZE == 64:
4712 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
4713 // .word 0x6666; rex64; call __tls_get_addr@PLT
4714 // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
4715 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
4716 // .word 0x66; rex64; call *__tls_get_addr@GOTPCREL(%rip)
4717 // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
4718 // For SIZE == 32:
4719 // leaq foo@tlsgd(%rip),%rdi;
4720 // .word 0x6666; rex64; call __tls_get_addr@PLT
4721 // ==> movl %fs:0,%eax; addq x@gottpoff(%rip),%rax
4722 // leaq foo@tlsgd(%rip),%rdi;
4723 // .word 0x66; rex64; call *__tls_get_addr@GOTPCREL(%rip)
4724 // ==> movl %fs:0,%eax; addq x@gottpoff(%rip),%rax
4726 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
4727 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4728 (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0
4729 || memcmp(view + 4, "\x66\x48\xff", 3) == 0));
4731 if (size == 64)
4733 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
4734 -4);
4735 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4736 (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
4737 memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0",
4738 16);
4740 else
4742 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
4743 -3);
4744 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4745 (memcmp(view - 3, "\x48\x8d\x3d", 3) == 0));
4746 memcpy(view - 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0",
4747 15);
4750 const elfcpp::Elf_Xword addend = rela.get_r_addend();
4751 Relocate_functions<size, false>::pcrela32(view + 8, value, addend - 8,
4752 address);
4754 // The next reloc should be a PLT32 reloc against __tls_get_addr.
4755 // We can skip it.
4756 this->skip_call_tls_get_addr_ = true;
4759 // Do a relocation in which we convert a TLS General-Dynamic to a
4760 // Local-Exec.
4762 template<int size>
4763 inline void
4764 Target_x86_64<size>::Relocate::tls_gd_to_le(
4765 const Relocate_info<size, false>* relinfo,
4766 size_t relnum,
4767 Output_segment* tls_segment,
4768 const elfcpp::Rela<size, false>& rela,
4769 unsigned int,
4770 typename elfcpp::Elf_types<size>::Elf_Addr value,
4771 unsigned char* view,
4772 section_size_type view_size)
4774 // For SIZE == 64:
4775 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
4776 // .word 0x6666; rex64; call __tls_get_addr@PLT
4777 // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
4778 // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
4779 // .word 0x66; rex64; call *__tls_get_addr@GOTPCREL(%rip)
4780 // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
4781 // For SIZE == 32:
4782 // leaq foo@tlsgd(%rip),%rdi;
4783 // .word 0x6666; rex64; call __tls_get_addr@PLT
4784 // ==> movl %fs:0,%eax; leaq x@tpoff(%rax),%rax
4785 // leaq foo@tlsgd(%rip),%rdi;
4786 // .word 0x66; rex64; call *__tls_get_addr@GOTPCREL(%rip)
4787 // ==> movl %fs:0,%eax; leaq x@tpoff(%rax),%rax
4789 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
4790 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4791 (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0
4792 || memcmp(view + 4, "\x66\x48\xff", 3) == 0));
4794 if (size == 64)
4796 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
4797 -4);
4798 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4799 (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
4800 memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0",
4801 16);
4803 else
4805 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size,
4806 -3);
4807 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4808 (memcmp(view - 3, "\x48\x8d\x3d", 3) == 0));
4810 memcpy(view - 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0",
4811 15);
4814 value -= tls_segment->memsz();
4815 Relocate_functions<size, false>::rela32(view + 8, value, 0);
4817 // The next reloc should be a PLT32 reloc against __tls_get_addr.
4818 // We can skip it.
4819 this->skip_call_tls_get_addr_ = true;
4822 // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
4824 template<int size>
4825 inline void
4826 Target_x86_64<size>::Relocate::tls_desc_gd_to_ie(
4827 const Relocate_info<size, false>* relinfo,
4828 size_t relnum,
4829 const elfcpp::Rela<size, false>& rela,
4830 unsigned int r_type,
4831 typename elfcpp::Elf_types<size>::Elf_Addr value,
4832 unsigned char* view,
4833 typename elfcpp::Elf_types<size>::Elf_Addr address,
4834 section_size_type view_size)
4836 if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
4838 // leaq foo@tlsdesc(%rip), %rax
4839 // ==> movq foo@gottpoff(%rip), %rax
4840 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
4841 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
4842 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4843 view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05);
4844 view[-2] = 0x8b;
4845 const elfcpp::Elf_Xword addend = rela.get_r_addend();
4846 Relocate_functions<size, false>::pcrela32(view, value, addend, address);
4848 else
4850 // call *foo@tlscall(%rax)
4851 // ==> nop; nop
4852 gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
4853 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
4854 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4855 view[0] == 0xff && view[1] == 0x10);
4856 view[0] = 0x66;
4857 view[1] = 0x90;
4861 // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
4863 template<int size>
4864 inline void
4865 Target_x86_64<size>::Relocate::tls_desc_gd_to_le(
4866 const Relocate_info<size, false>* relinfo,
4867 size_t relnum,
4868 Output_segment* tls_segment,
4869 const elfcpp::Rela<size, false>& rela,
4870 unsigned int r_type,
4871 typename elfcpp::Elf_types<size>::Elf_Addr value,
4872 unsigned char* view,
4873 section_size_type view_size)
4875 if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
4877 // leaq foo@tlsdesc(%rip), %rax
4878 // ==> movq foo@tpoff, %rax
4879 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
4880 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
4881 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4882 view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05);
4883 view[-2] = 0xc7;
4884 view[-1] = 0xc0;
4885 value -= tls_segment->memsz();
4886 Relocate_functions<size, false>::rela32(view, value, 0);
4888 else
4890 // call *foo@tlscall(%rax)
4891 // ==> nop; nop
4892 gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
4893 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
4894 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4895 view[0] == 0xff && view[1] == 0x10);
4896 view[0] = 0x66;
4897 view[1] = 0x90;
4901 template<int size>
4902 inline void
4903 Target_x86_64<size>::Relocate::tls_ld_to_le(
4904 const Relocate_info<size, false>* relinfo,
4905 size_t relnum,
4906 Output_segment*,
4907 const elfcpp::Rela<size, false>& rela,
4908 unsigned int,
4909 typename elfcpp::Elf_types<size>::Elf_Addr,
4910 unsigned char* view,
4911 section_size_type view_size)
4913 // leaq foo@tlsld(%rip),%rdi; call __tls_get_addr@plt;
4914 // For SIZE == 64:
4915 // ... leq foo@dtpoff(%rax),%reg
4916 // ==> .word 0x6666; .byte 0x66; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
4917 // For SIZE == 32:
4918 // ... leq foo@dtpoff(%rax),%reg
4919 // ==> nopl 0x0(%rax); movl %fs:0,%eax ... leaq x@tpoff(%rax),%rdx
4920 // leaq foo@tlsld(%rip),%rdi; call *__tls_get_addr@GOTPCREL(%rip)
4921 // For SIZE == 64:
4922 // ... leq foo@dtpoff(%rax),%reg
4923 // ==> .word 0x6666; .byte 0x6666; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
4924 // For SIZE == 32:
4925 // ... leq foo@dtpoff(%rax),%reg
4926 // ==> nopw 0x0(%rax); movl %fs:0,%eax ... leaq x@tpoff(%rax),%rdx
4928 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
4929 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 9);
4931 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4932 view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x3d);
4934 tls::check_tls(relinfo, relnum, rela.get_r_offset(),
4935 view[4] == 0xe8 || view[4] == 0xff);
4937 if (view[4] == 0xe8)
4939 if (size == 64)
4940 memcpy(view - 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12);
4941 else
4942 memcpy(view - 3, "\x0f\x1f\x40\x00\x64\x8b\x04\x25\0\0\0\0", 12);
4944 else
4946 if (size == 64)
4947 memcpy(view - 3, "\x66\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0",
4948 13);
4949 else
4950 memcpy(view - 3, "\x66\x0f\x1f\x40\x00\x64\x8b\x04\x25\0\0\0\0",
4951 13);
4954 // The next reloc should be a PLT32 reloc against __tls_get_addr.
4955 // We can skip it.
4956 this->skip_call_tls_get_addr_ = true;
4959 // Do a relocation in which we convert a TLS Initial-Exec to a
4960 // Local-Exec.
4962 template<int size>
4963 inline void
4964 Target_x86_64<size>::Relocate::tls_ie_to_le(
4965 const Relocate_info<size, false>* relinfo,
4966 size_t relnum,
4967 Output_segment* tls_segment,
4968 const elfcpp::Rela<size, false>& rela,
4969 unsigned int,
4970 typename elfcpp::Elf_types<size>::Elf_Addr value,
4971 unsigned char* view,
4972 section_size_type view_size)
4974 // We need to examine the opcodes to figure out which instruction we
4975 // are looking at.
4977 // movq foo@gottpoff(%rip),%reg ==> movq $YY,%reg
4978 // addq foo@gottpoff(%rip),%reg ==> addq $YY,%reg
4980 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
4981 tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
4983 unsigned char op1 = view[-3];
4984 unsigned char op2 = view[-2];
4985 unsigned char op3 = view[-1];
4986 unsigned char reg = op3 >> 3;
4988 if (op2 == 0x8b)
4990 // movq
4991 if (op1 == 0x4c)
4992 view[-3] = 0x49;
4993 else if (size == 32 && op1 == 0x44)
4994 view[-3] = 0x41;
4995 view[-2] = 0xc7;
4996 view[-1] = 0xc0 | reg;
4998 else if (reg == 4)
5000 // Special handling for %rsp.
5001 if (op1 == 0x4c)
5002 view[-3] = 0x49;
5003 else if (size == 32 && op1 == 0x44)
5004 view[-3] = 0x41;
5005 view[-2] = 0x81;
5006 view[-1] = 0xc0 | reg;
5008 else
5010 // addq
5011 if (op1 == 0x4c)
5012 view[-3] = 0x4d;
5013 else if (size == 32 && op1 == 0x44)
5014 view[-3] = 0x45;
5015 view[-2] = 0x8d;
5016 view[-1] = 0x80 | reg | (reg << 3);
5019 if (tls_segment != NULL)
5020 value -= tls_segment->memsz();
5021 Relocate_functions<size, false>::rela32(view, value, 0);
5024 // Relocate section data.
5026 template<int size>
5027 void
5028 Target_x86_64<size>::relocate_section(
5029 const Relocate_info<size, false>* relinfo,
5030 unsigned int sh_type,
5031 const unsigned char* prelocs,
5032 size_t reloc_count,
5033 Output_section* output_section,
5034 bool needs_special_offset_handling,
5035 unsigned char* view,
5036 typename elfcpp::Elf_types<size>::Elf_Addr address,
5037 section_size_type view_size,
5038 const Reloc_symbol_changes* reloc_symbol_changes)
5040 typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
5041 Classify_reloc;
5043 gold_assert(sh_type == elfcpp::SHT_RELA);
5045 gold::relocate_section<size, false, Target_x86_64<size>, Relocate,
5046 gold::Default_comdat_behavior, Classify_reloc>(
5047 relinfo,
5048 this,
5049 prelocs,
5050 reloc_count,
5051 output_section,
5052 needs_special_offset_handling,
5053 view,
5054 address,
5055 view_size,
5056 reloc_symbol_changes);
5059 // Apply an incremental relocation. Incremental relocations always refer
5060 // to global symbols.
5062 template<int size>
5063 void
5064 Target_x86_64<size>::apply_relocation(
5065 const Relocate_info<size, false>* relinfo,
5066 typename elfcpp::Elf_types<size>::Elf_Addr r_offset,
5067 unsigned int r_type,
5068 typename elfcpp::Elf_types<size>::Elf_Swxword r_addend,
5069 const Symbol* gsym,
5070 unsigned char* view,
5071 typename elfcpp::Elf_types<size>::Elf_Addr address,
5072 section_size_type view_size)
5074 gold::apply_relocation<size, false, Target_x86_64<size>,
5075 typename Target_x86_64<size>::Relocate>(
5076 relinfo,
5077 this,
5078 r_offset,
5079 r_type,
5080 r_addend,
5081 gsym,
5082 view,
5083 address,
5084 view_size);
5087 // Scan the relocs during a relocatable link.
5089 template<int size>
5090 void
5091 Target_x86_64<size>::scan_relocatable_relocs(
5092 Symbol_table* symtab,
5093 Layout* layout,
5094 Sized_relobj_file<size, false>* object,
5095 unsigned int data_shndx,
5096 unsigned int sh_type,
5097 const unsigned char* prelocs,
5098 size_t reloc_count,
5099 Output_section* output_section,
5100 bool needs_special_offset_handling,
5101 size_t local_symbol_count,
5102 const unsigned char* plocal_symbols,
5103 Relocatable_relocs* rr)
5105 typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
5106 Classify_reloc;
5107 typedef gold::Default_scan_relocatable_relocs<Classify_reloc>
5108 Scan_relocatable_relocs;
5110 gold_assert(sh_type == elfcpp::SHT_RELA);
5112 gold::scan_relocatable_relocs<size, false, Scan_relocatable_relocs>(
5113 symtab,
5114 layout,
5115 object,
5116 data_shndx,
5117 prelocs,
5118 reloc_count,
5119 output_section,
5120 needs_special_offset_handling,
5121 local_symbol_count,
5122 plocal_symbols,
5123 rr);
5126 // Scan the relocs for --emit-relocs.
5128 template<int size>
5129 void
5130 Target_x86_64<size>::emit_relocs_scan(
5131 Symbol_table* symtab,
5132 Layout* layout,
5133 Sized_relobj_file<size, false>* object,
5134 unsigned int data_shndx,
5135 unsigned int sh_type,
5136 const unsigned char* prelocs,
5137 size_t reloc_count,
5138 Output_section* output_section,
5139 bool needs_special_offset_handling,
5140 size_t local_symbol_count,
5141 const unsigned char* plocal_syms,
5142 Relocatable_relocs* rr)
5144 typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
5145 Classify_reloc;
5146 typedef gold::Default_emit_relocs_strategy<Classify_reloc>
5147 Emit_relocs_strategy;
5149 gold_assert(sh_type == elfcpp::SHT_RELA);
5151 gold::scan_relocatable_relocs<size, false, Emit_relocs_strategy>(
5152 symtab,
5153 layout,
5154 object,
5155 data_shndx,
5156 prelocs,
5157 reloc_count,
5158 output_section,
5159 needs_special_offset_handling,
5160 local_symbol_count,
5161 plocal_syms,
5162 rr);
5165 // Relocate a section during a relocatable link.
5167 template<int size>
5168 void
5169 Target_x86_64<size>::relocate_relocs(
5170 const Relocate_info<size, false>* relinfo,
5171 unsigned int sh_type,
5172 const unsigned char* prelocs,
5173 size_t reloc_count,
5174 Output_section* output_section,
5175 typename elfcpp::Elf_types<size>::Elf_Off offset_in_output_section,
5176 unsigned char* view,
5177 typename elfcpp::Elf_types<size>::Elf_Addr view_address,
5178 section_size_type view_size,
5179 unsigned char* reloc_view,
5180 section_size_type reloc_view_size)
5182 typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
5183 Classify_reloc;
5185 gold_assert(sh_type == elfcpp::SHT_RELA);
5187 gold::relocate_relocs<size, false, Classify_reloc>(
5188 relinfo,
5189 prelocs,
5190 reloc_count,
5191 output_section,
5192 offset_in_output_section,
5193 view,
5194 view_address,
5195 view_size,
5196 reloc_view,
5197 reloc_view_size);
5200 // Return the value to use for a dynamic which requires special
5201 // treatment. This is how we support equality comparisons of function
5202 // pointers across shared library boundaries, as described in the
5203 // processor specific ABI supplement.
5205 template<int size>
5206 uint64_t
5207 Target_x86_64<size>::do_dynsym_value(const Symbol* gsym) const
5209 gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
5210 return this->plt_address_for_global(gsym);
5213 // Return a string used to fill a code section with nops to take up
5214 // the specified length.
5216 template<int size>
5217 std::string
5218 Target_x86_64<size>::do_code_fill(section_size_type length) const
5220 if (length >= 16)
5222 // Build a jmpq instruction to skip over the bytes.
5223 unsigned char jmp[5];
5224 jmp[0] = 0xe9;
5225 elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
5226 return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
5227 + std::string(length - 5, static_cast<char>(0x90)));
5230 // Nop sequences of various lengths.
5231 const char nop1[1] = { '\x90' }; // nop
5232 const char nop2[2] = { '\x66', '\x90' }; // xchg %ax %ax
5233 const char nop3[3] = { '\x0f', '\x1f', '\x00' }; // nop (%rax)
5234 const char nop4[4] = { '\x0f', '\x1f', '\x40', // nop 0(%rax)
5235 '\x00'};
5236 const char nop5[5] = { '\x0f', '\x1f', '\x44', // nop 0(%rax,%rax,1)
5237 '\x00', '\x00' };
5238 const char nop6[6] = { '\x66', '\x0f', '\x1f', // nopw 0(%rax,%rax,1)
5239 '\x44', '\x00', '\x00' };
5240 const char nop7[7] = { '\x0f', '\x1f', '\x80', // nopl 0L(%rax)
5241 '\x00', '\x00', '\x00',
5242 '\x00' };
5243 const char nop8[8] = { '\x0f', '\x1f', '\x84', // nopl 0L(%rax,%rax,1)
5244 '\x00', '\x00', '\x00',
5245 '\x00', '\x00' };
5246 const char nop9[9] = { '\x66', '\x0f', '\x1f', // nopw 0L(%rax,%rax,1)
5247 '\x84', '\x00', '\x00',
5248 '\x00', '\x00', '\x00' };
5249 const char nop10[10] = { '\x66', '\x2e', '\x0f', // nopw %cs:0L(%rax,%rax,1)
5250 '\x1f', '\x84', '\x00',
5251 '\x00', '\x00', '\x00',
5252 '\x00' };
5253 const char nop11[11] = { '\x66', '\x66', '\x2e', // data16
5254 '\x0f', '\x1f', '\x84', // nopw %cs:0L(%rax,%rax,1)
5255 '\x00', '\x00', '\x00',
5256 '\x00', '\x00' };
5257 const char nop12[12] = { '\x66', '\x66', '\x66', // data16; data16
5258 '\x2e', '\x0f', '\x1f', // nopw %cs:0L(%rax,%rax,1)
5259 '\x84', '\x00', '\x00',
5260 '\x00', '\x00', '\x00' };
5261 const char nop13[13] = { '\x66', '\x66', '\x66', // data16; data16; data16
5262 '\x66', '\x2e', '\x0f', // nopw %cs:0L(%rax,%rax,1)
5263 '\x1f', '\x84', '\x00',
5264 '\x00', '\x00', '\x00',
5265 '\x00' };
5266 const char nop14[14] = { '\x66', '\x66', '\x66', // data16; data16; data16
5267 '\x66', '\x66', '\x2e', // data16
5268 '\x0f', '\x1f', '\x84', // nopw %cs:0L(%rax,%rax,1)
5269 '\x00', '\x00', '\x00',
5270 '\x00', '\x00' };
5271 const char nop15[15] = { '\x66', '\x66', '\x66', // data16; data16; data16
5272 '\x66', '\x66', '\x66', // data16; data16
5273 '\x2e', '\x0f', '\x1f', // nopw %cs:0L(%rax,%rax,1)
5274 '\x84', '\x00', '\x00',
5275 '\x00', '\x00', '\x00' };
5277 const char* nops[16] = {
5278 NULL,
5279 nop1, nop2, nop3, nop4, nop5, nop6, nop7,
5280 nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
5283 return std::string(nops[length], length);
5286 // Return the addend to use for a target specific relocation. The
5287 // only target specific relocation is R_X86_64_TLSDESC for a local
5288 // symbol. We want to set the addend is the offset of the local
5289 // symbol in the TLS segment.
5291 template<int size>
5292 uint64_t
5293 Target_x86_64<size>::do_reloc_addend(void* arg, unsigned int r_type,
5294 uint64_t) const
5296 gold_assert(r_type == elfcpp::R_X86_64_TLSDESC);
5297 uintptr_t intarg = reinterpret_cast<uintptr_t>(arg);
5298 gold_assert(intarg < this->tlsdesc_reloc_info_.size());
5299 const Tlsdesc_info& ti(this->tlsdesc_reloc_info_[intarg]);
5300 const Symbol_value<size>* psymval = ti.object->local_symbol(ti.r_sym);
5301 gold_assert(psymval->is_tls_symbol());
5302 // The value of a TLS symbol is the offset in the TLS segment.
5303 return psymval->value(ti.object, 0);
5306 // Return the value to use for the base of a DW_EH_PE_datarel offset
5307 // in an FDE. Solaris and SVR4 use DW_EH_PE_datarel because their
5308 // assembler can not write out the difference between two labels in
5309 // different sections, so instead of using a pc-relative value they
5310 // use an offset from the GOT.
5312 template<int size>
5313 uint64_t
5314 Target_x86_64<size>::do_ehframe_datarel_base() const
5316 gold_assert(this->global_offset_table_ != NULL);
5317 Symbol* sym = this->global_offset_table_;
5318 Sized_symbol<size>* ssym = static_cast<Sized_symbol<size>*>(sym);
5319 return ssym->value();
5322 // FNOFFSET in section SHNDX in OBJECT is the start of a function
5323 // compiled with -fsplit-stack. The function calls non-split-stack
5324 // code. We have to change the function so that it always ensures
5325 // that it has enough stack space to run some random function.
5327 static const unsigned char cmp_insn_32[] = { 0x64, 0x3b, 0x24, 0x25 };
5328 static const unsigned char lea_r10_insn_32[] = { 0x44, 0x8d, 0x94, 0x24 };
5329 static const unsigned char lea_r11_insn_32[] = { 0x44, 0x8d, 0x9c, 0x24 };
5331 static const unsigned char cmp_insn_64[] = { 0x64, 0x48, 0x3b, 0x24, 0x25 };
5332 static const unsigned char lea_r10_insn_64[] = { 0x4c, 0x8d, 0x94, 0x24 };
5333 static const unsigned char lea_r11_insn_64[] = { 0x4c, 0x8d, 0x9c, 0x24 };
5335 template<int size>
5336 void
5337 Target_x86_64<size>::do_calls_non_split(Relobj* object, unsigned int shndx,
5338 section_offset_type fnoffset,
5339 section_size_type fnsize,
5340 const unsigned char*,
5341 size_t,
5342 unsigned char* view,
5343 section_size_type view_size,
5344 std::string* from,
5345 std::string* to) const
5347 const char* const cmp_insn = reinterpret_cast<const char*>
5348 (size == 32 ? cmp_insn_32 : cmp_insn_64);
5349 const char* const lea_r10_insn = reinterpret_cast<const char*>
5350 (size == 32 ? lea_r10_insn_32 : lea_r10_insn_64);
5351 const char* const lea_r11_insn = reinterpret_cast<const char*>
5352 (size == 32 ? lea_r11_insn_32 : lea_r11_insn_64);
5354 const size_t cmp_insn_len =
5355 (size == 32 ? sizeof(cmp_insn_32) : sizeof(cmp_insn_64));
5356 const size_t lea_r10_insn_len =
5357 (size == 32 ? sizeof(lea_r10_insn_32) : sizeof(lea_r10_insn_64));
5358 const size_t lea_r11_insn_len =
5359 (size == 32 ? sizeof(lea_r11_insn_32) : sizeof(lea_r11_insn_64));
5360 const size_t nop_len = (size == 32 ? 7 : 8);
5362 // The function starts with a comparison of the stack pointer and a
5363 // field in the TCB. This is followed by a jump.
5365 // cmp %fs:NN,%rsp
5366 if (this->match_view(view, view_size, fnoffset, cmp_insn, cmp_insn_len)
5367 && fnsize > nop_len + 1)
5369 // We will call __morestack if the carry flag is set after this
5370 // comparison. We turn the comparison into an stc instruction
5371 // and some nops.
5372 view[fnoffset] = '\xf9';
5373 this->set_view_to_nop(view, view_size, fnoffset + 1, nop_len);
5375 // lea NN(%rsp),%r10
5376 // lea NN(%rsp),%r11
5377 else if ((this->match_view(view, view_size, fnoffset,
5378 lea_r10_insn, lea_r10_insn_len)
5379 || this->match_view(view, view_size, fnoffset,
5380 lea_r11_insn, lea_r11_insn_len))
5381 && fnsize > 8)
5383 // This is loading an offset from the stack pointer for a
5384 // comparison. The offset is negative, so we decrease the
5385 // offset by the amount of space we need for the stack. This
5386 // means we will avoid calling __morestack if there happens to
5387 // be plenty of space on the stack already.
5388 unsigned char* pval = view + fnoffset + 4;
5389 uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
5390 val -= parameters->options().split_stack_adjust_size();
5391 elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
5393 else
5395 if (!object->has_no_split_stack())
5396 object->error(_("failed to match split-stack sequence at "
5397 "section %u offset %0zx"),
5398 shndx, static_cast<size_t>(fnoffset));
5399 return;
5402 // We have to change the function so that it calls
5403 // __morestack_non_split instead of __morestack. The former will
5404 // allocate additional stack space.
5405 *from = "__morestack";
5406 *to = "__morestack_non_split";
5409 // The selector for x86_64 object files. Note this is never instantiated
5410 // directly. It's only used in Target_selector_x86_64_nacl, below.
5412 template<int size>
5413 class Target_selector_x86_64 : public Target_selector_freebsd
5415 public:
5416 Target_selector_x86_64()
5417 : Target_selector_freebsd(elfcpp::EM_X86_64, size, false,
5418 (size == 64
5419 ? "elf64-x86-64" : "elf32-x86-64"),
5420 (size == 64
5421 ? "elf64-x86-64-freebsd"
5422 : "elf32-x86-64-freebsd"),
5423 (size == 64 ? "elf_x86_64" : "elf32_x86_64"))
5426 Target*
5427 do_instantiate_target()
5428 { return new Target_x86_64<size>(); }
5432 // NaCl variant. It uses different PLT contents.
5434 template<int size>
5435 class Output_data_plt_x86_64_nacl : public Output_data_plt_x86_64<size>
5437 public:
5438 Output_data_plt_x86_64_nacl(Layout* layout,
5439 Output_data_got<64, false>* got,
5440 Output_data_got_plt_x86_64* got_plt,
5441 Output_data_space* got_irelative)
5442 : Output_data_plt_x86_64<size>(layout, plt_entry_size,
5443 got, got_plt, got_irelative)
5446 Output_data_plt_x86_64_nacl(Layout* layout,
5447 Output_data_got<64, false>* got,
5448 Output_data_got_plt_x86_64* got_plt,
5449 Output_data_space* got_irelative,
5450 unsigned int plt_count)
5451 : Output_data_plt_x86_64<size>(layout, plt_entry_size,
5452 got, got_plt, got_irelative,
5453 plt_count)
5456 protected:
5457 virtual unsigned int
5458 do_get_plt_entry_size() const
5459 { return plt_entry_size; }
5461 virtual void
5462 do_add_eh_frame(Layout* layout)
5464 layout->add_eh_frame_for_plt(this,
5465 this->plt_eh_frame_cie,
5466 this->plt_eh_frame_cie_size,
5467 plt_eh_frame_fde,
5468 plt_eh_frame_fde_size);
5471 virtual void
5472 do_fill_first_plt_entry(unsigned char* pov,
5473 typename elfcpp::Elf_types<size>::Elf_Addr got_addr,
5474 typename elfcpp::Elf_types<size>::Elf_Addr plt_addr);
5476 virtual unsigned int
5477 do_fill_plt_entry(unsigned char* pov,
5478 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
5479 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
5480 unsigned int got_offset,
5481 unsigned int plt_offset,
5482 unsigned int plt_index);
5484 virtual void
5485 do_fill_tlsdesc_entry(unsigned char* pov,
5486 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
5487 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
5488 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
5489 unsigned int tlsdesc_got_offset,
5490 unsigned int plt_offset);
5492 private:
5493 // The size of an entry in the PLT.
5494 static const int plt_entry_size = 64;
5496 // The first entry in the PLT.
5497 static const unsigned char first_plt_entry[plt_entry_size];
5499 // Other entries in the PLT for an executable.
5500 static const unsigned char plt_entry[plt_entry_size];
5502 // The reserved TLSDESC entry in the PLT for an executable.
5503 static const unsigned char tlsdesc_plt_entry[plt_entry_size];
5505 // The .eh_frame unwind information for the PLT.
5506 static const int plt_eh_frame_fde_size = 32;
5507 static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
5510 template<int size>
5511 class Target_x86_64_nacl : public Target_x86_64<size>
5513 public:
5514 Target_x86_64_nacl()
5515 : Target_x86_64<size>(&x86_64_nacl_info)
5518 virtual Output_data_plt_x86_64<size>*
5519 do_make_data_plt(Layout* layout,
5520 Output_data_got<64, false>* got,
5521 Output_data_got_plt_x86_64* got_plt,
5522 Output_data_space* got_irelative)
5524 return new Output_data_plt_x86_64_nacl<size>(layout, got, got_plt,
5525 got_irelative);
5528 virtual Output_data_plt_x86_64<size>*
5529 do_make_data_plt(Layout* layout,
5530 Output_data_got<64, false>* got,
5531 Output_data_got_plt_x86_64* got_plt,
5532 Output_data_space* got_irelative,
5533 unsigned int plt_count)
5535 return new Output_data_plt_x86_64_nacl<size>(layout, got, got_plt,
5536 got_irelative,
5537 plt_count);
5540 virtual std::string
5541 do_code_fill(section_size_type length) const;
5543 private:
5544 static const Target::Target_info x86_64_nacl_info;
5547 template<>
5548 const Target::Target_info Target_x86_64_nacl<64>::x86_64_nacl_info =
5550 64, // size
5551 false, // is_big_endian
5552 elfcpp::EM_X86_64, // machine_code
5553 false, // has_make_symbol
5554 false, // has_resolve
5555 true, // has_code_fill
5556 true, // is_default_stack_executable
5557 true, // can_icf_inline_merge_sections
5558 '\0', // wrap_char
5559 "/lib64/ld-nacl-x86-64.so.1", // dynamic_linker
5560 0x20000, // default_text_segment_address
5561 0x10000, // abi_pagesize (overridable by -z max-page-size)
5562 0x10000, // common_pagesize (overridable by -z common-page-size)
5563 true, // isolate_execinstr
5564 0x10000000, // rosegment_gap
5565 elfcpp::SHN_UNDEF, // small_common_shndx
5566 elfcpp::SHN_X86_64_LCOMMON, // large_common_shndx
5567 0, // small_common_section_flags
5568 elfcpp::SHF_X86_64_LARGE, // large_common_section_flags
5569 NULL, // attributes_section
5570 NULL, // attributes_vendor
5571 "_start", // entry_symbol_name
5572 32, // hash_entry_size
5575 template<>
5576 const Target::Target_info Target_x86_64_nacl<32>::x86_64_nacl_info =
5578 32, // size
5579 false, // is_big_endian
5580 elfcpp::EM_X86_64, // machine_code
5581 false, // has_make_symbol
5582 false, // has_resolve
5583 true, // has_code_fill
5584 true, // is_default_stack_executable
5585 true, // can_icf_inline_merge_sections
5586 '\0', // wrap_char
5587 "/lib/ld-nacl-x86-64.so.1", // dynamic_linker
5588 0x20000, // default_text_segment_address
5589 0x10000, // abi_pagesize (overridable by -z max-page-size)
5590 0x10000, // common_pagesize (overridable by -z common-page-size)
5591 true, // isolate_execinstr
5592 0x10000000, // rosegment_gap
5593 elfcpp::SHN_UNDEF, // small_common_shndx
5594 elfcpp::SHN_X86_64_LCOMMON, // large_common_shndx
5595 0, // small_common_section_flags
5596 elfcpp::SHF_X86_64_LARGE, // large_common_section_flags
5597 NULL, // attributes_section
5598 NULL, // attributes_vendor
5599 "_start", // entry_symbol_name
5600 32, // hash_entry_size
5603 #define NACLMASK 0xe0 // 32-byte alignment mask.
5605 // The first entry in the PLT.
5607 template<int size>
5608 const unsigned char
5609 Output_data_plt_x86_64_nacl<size>::first_plt_entry[plt_entry_size] =
5611 0xff, 0x35, // pushq contents of memory address
5612 0, 0, 0, 0, // replaced with address of .got + 8
5613 0x4c, 0x8b, 0x1d, // mov GOT+16(%rip), %r11
5614 0, 0, 0, 0, // replaced with address of .got + 16
5615 0x41, 0x83, 0xe3, NACLMASK, // and $-32, %r11d
5616 0x4d, 0x01, 0xfb, // add %r15, %r11
5617 0x41, 0xff, 0xe3, // jmpq *%r11
5619 // 9-byte nop sequence to pad out to the next 32-byte boundary.
5620 0x66, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw 0x0(%rax,%rax,1)
5622 // 32 bytes of nop to pad out to the standard size
5623 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
5624 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
5625 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
5626 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
5627 0x66, // excess data32 prefix
5628 0x90 // nop
5631 template<int size>
5632 void
5633 Output_data_plt_x86_64_nacl<size>::do_fill_first_plt_entry(
5634 unsigned char* pov,
5635 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
5636 typename elfcpp::Elf_types<size>::Elf_Addr plt_address)
5638 memcpy(pov, first_plt_entry, plt_entry_size);
5639 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
5640 (got_address + 8
5641 - (plt_address + 2 + 4)));
5642 elfcpp::Swap_unaligned<32, false>::writeval(pov + 9,
5643 (got_address + 16
5644 - (plt_address + 9 + 4)));
5647 // Subsequent entries in the PLT.
5649 template<int size>
5650 const unsigned char
5651 Output_data_plt_x86_64_nacl<size>::plt_entry[plt_entry_size] =
5653 0x4c, 0x8b, 0x1d, // mov name@GOTPCREL(%rip),%r11
5654 0, 0, 0, 0, // replaced with address of symbol in .got
5655 0x41, 0x83, 0xe3, NACLMASK, // and $-32, %r11d
5656 0x4d, 0x01, 0xfb, // add %r15, %r11
5657 0x41, 0xff, 0xe3, // jmpq *%r11
5659 // 15-byte nop sequence to pad out to the next 32-byte boundary.
5660 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
5661 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
5663 // Lazy GOT entries point here (32-byte aligned).
5664 0x68, // pushq immediate
5665 0, 0, 0, 0, // replaced with index into relocation table
5666 0xe9, // jmp relative
5667 0, 0, 0, 0, // replaced with offset to start of .plt0
5669 // 22 bytes of nop to pad out to the standard size.
5670 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
5671 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
5672 0x0f, 0x1f, 0x80, 0, 0, 0, 0, // nopl 0x0(%rax)
5675 template<int size>
5676 unsigned int
5677 Output_data_plt_x86_64_nacl<size>::do_fill_plt_entry(
5678 unsigned char* pov,
5679 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
5680 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
5681 unsigned int got_offset,
5682 unsigned int plt_offset,
5683 unsigned int plt_index)
5685 memcpy(pov, plt_entry, plt_entry_size);
5686 elfcpp::Swap_unaligned<32, false>::writeval(pov + 3,
5687 (got_address + got_offset
5688 - (plt_address + plt_offset
5689 + 3 + 4)));
5691 elfcpp::Swap_unaligned<32, false>::writeval(pov + 33, plt_index);
5692 elfcpp::Swap_unaligned<32, false>::writeval(pov + 38,
5693 - (plt_offset + 38 + 4));
5695 return 32;
5698 // The reserved TLSDESC entry in the PLT.
5700 template<int size>
5701 const unsigned char
5702 Output_data_plt_x86_64_nacl<size>::tlsdesc_plt_entry[plt_entry_size] =
5704 0xff, 0x35, // pushq x(%rip)
5705 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
5706 0x4c, 0x8b, 0x1d, // mov y(%rip),%r11
5707 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
5708 0x41, 0x83, 0xe3, NACLMASK, // and $-32, %r11d
5709 0x4d, 0x01, 0xfb, // add %r15, %r11
5710 0x41, 0xff, 0xe3, // jmpq *%r11
5712 // 41 bytes of nop to pad out to the standard size.
5713 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
5714 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
5715 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes
5716 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
5717 0x66, 0x66, // excess data32 prefixes
5718 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1)
5721 template<int size>
5722 void
5723 Output_data_plt_x86_64_nacl<size>::do_fill_tlsdesc_entry(
5724 unsigned char* pov,
5725 typename elfcpp::Elf_types<size>::Elf_Addr got_address,
5726 typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
5727 typename elfcpp::Elf_types<size>::Elf_Addr got_base,
5728 unsigned int tlsdesc_got_offset,
5729 unsigned int plt_offset)
5731 memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
5732 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
5733 (got_address + 8
5734 - (plt_address + plt_offset
5735 + 2 + 4)));
5736 elfcpp::Swap_unaligned<32, false>::writeval(pov + 9,
5737 (got_base
5738 + tlsdesc_got_offset
5739 - (plt_address + plt_offset
5740 + 9 + 4)));
5743 // The .eh_frame unwind information for the PLT.
5745 template<int size>
5746 const unsigned char
5747 Output_data_plt_x86_64_nacl<size>::plt_eh_frame_fde[plt_eh_frame_fde_size] =
5749 0, 0, 0, 0, // Replaced with offset to .plt.
5750 0, 0, 0, 0, // Replaced with size of .plt.
5751 0, // Augmentation size.
5752 elfcpp::DW_CFA_def_cfa_offset, 16, // DW_CFA_def_cfa_offset: 16.
5753 elfcpp::DW_CFA_advance_loc + 6, // Advance 6 to __PLT__ + 6.
5754 elfcpp::DW_CFA_def_cfa_offset, 24, // DW_CFA_def_cfa_offset: 24.
5755 elfcpp::DW_CFA_advance_loc + 58, // Advance 58 to __PLT__ + 64.
5756 elfcpp::DW_CFA_def_cfa_expression, // DW_CFA_def_cfa_expression.
5757 13, // Block length.
5758 elfcpp::DW_OP_breg7, 8, // Push %rsp + 8.
5759 elfcpp::DW_OP_breg16, 0, // Push %rip.
5760 elfcpp::DW_OP_const1u, 63, // Push 0x3f.
5761 elfcpp::DW_OP_and, // & (%rip & 0x3f).
5762 elfcpp::DW_OP_const1u, 37, // Push 0x25.
5763 elfcpp::DW_OP_ge, // >= ((%rip & 0x3f) >= 0x25)
5764 elfcpp::DW_OP_lit3, // Push 3.
5765 elfcpp::DW_OP_shl, // << (((%rip & 0x3f) >= 0x25) << 3)
5766 elfcpp::DW_OP_plus, // + ((((%rip&0x3f)>=0x25)<<3)+%rsp+8
5767 elfcpp::DW_CFA_nop, // Align to 32 bytes.
5768 elfcpp::DW_CFA_nop
5771 // Return a string used to fill a code section with nops.
5772 // For NaCl, long NOPs are only valid if they do not cross
5773 // bundle alignment boundaries, so keep it simple with one-byte NOPs.
5774 template<int size>
5775 std::string
5776 Target_x86_64_nacl<size>::do_code_fill(section_size_type length) const
5778 return std::string(length, static_cast<char>(0x90));
5781 // The selector for x86_64-nacl object files.
5783 template<int size>
5784 class Target_selector_x86_64_nacl
5785 : public Target_selector_nacl<Target_selector_x86_64<size>,
5786 Target_x86_64_nacl<size> >
5788 public:
5789 Target_selector_x86_64_nacl()
5790 : Target_selector_nacl<Target_selector_x86_64<size>,
5791 Target_x86_64_nacl<size> >("x86-64",
5792 size == 64
5793 ? "elf64-x86-64-nacl"
5794 : "elf32-x86-64-nacl",
5795 size == 64
5796 ? "elf_x86_64_nacl"
5797 : "elf32_x86_64_nacl")
5801 Target_selector_x86_64_nacl<64> target_selector_x86_64;
5802 Target_selector_x86_64_nacl<32> target_selector_x32;
5804 } // End anonymous namespace.