Add static version of constructor test.
[deliverable/binutils-gdb.git] / gold / i386.cc
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1// i386.cc -- i386 target support for gold.
2
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3// Copyright 2006, 2007 Free Software Foundation, Inc.
4// Written by Ian Lance Taylor <iant@google.com>.
5
6// This file is part of gold.
7
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.
12
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.
17
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.
22
14bfc3f5 23#include "gold.h"
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24
25#include <cstring>
26
14bfc3f5 27#include "elfcpp.h"
7e1edb90 28#include "parameters.h"
92e059d8 29#include "reloc.h"
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30#include "i386.h"
31#include "object.h"
ead1e424 32#include "symtab.h"
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33#include "layout.h"
34#include "output.h"
14bfc3f5 35#include "target.h"
61ba1cf9 36#include "target-reloc.h"
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37#include "target-select.h"
38
39namespace
40{
41
42using namespace gold;
43
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44class Output_data_plt_i386;
45
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46// The i386 target class.
47
48class Target_i386 : public Sized_target<32, false>
49{
50 public:
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51 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
52
14bfc3f5 53 Target_i386()
ead1e424 54 : Sized_target<32, false>(&i386_info),
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55 got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
56 copy_relocs_(NULL), dynbss_(NULL)
14bfc3f5 57 { }
75f65a3e 58
92e059d8 59 // Scan the relocations to look for symbol adjustments.
61ba1cf9 60 void
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61 scan_relocs(const General_options& options,
62 Symbol_table* symtab,
ead1e424 63 Layout* layout,
f6ce93d6 64 Sized_relobj<32, false>* object,
a3ad94ed 65 unsigned int data_shndx,
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66 unsigned int sh_type,
67 const unsigned char* prelocs,
68 size_t reloc_count,
69 size_t local_symbol_count,
70 const unsigned char* plocal_symbols,
71 Symbol** global_symbols);
61ba1cf9 72
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73 // Finalize the sections.
74 void
7e1edb90 75 do_finalize_sections(Layout*);
5a6f7e2d 76
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77 // Relocate a section.
78 void
79 relocate_section(const Relocate_info<32, false>*,
80 unsigned int sh_type,
81 const unsigned char* prelocs,
82 size_t reloc_count,
83 unsigned char* view,
84 elfcpp::Elf_types<32>::Elf_Addr view_address,
85 off_t view_size);
86
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87 // Return a string used to fill a code section with nops.
88 std::string
89 do_code_fill(off_t length);
90
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91 private:
92 // The class which scans relocations.
93 struct Scan
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94 {
95 inline void
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96 local(const General_options& options, Symbol_table* symtab,
97 Layout* layout, Target_i386* target,
f6ce93d6 98 Sized_relobj<32, false>* object,
a3ad94ed 99 unsigned int data_shndx,
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100 const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
101 const elfcpp::Sym<32, false>& lsym);
61ba1cf9 102
92e059d8 103 inline void
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104 global(const General_options& options, Symbol_table* symtab,
105 Layout* layout, Target_i386* target,
f6ce93d6 106 Sized_relobj<32, false>* object,
a3ad94ed 107 unsigned int data_shndx,
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108 const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
109 Symbol* gsym);
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110 };
111
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112 // The class which implements relocation.
113 class Relocate
114 {
115 public:
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116 Relocate()
117 : skip_call_tls_get_addr_(false)
118 { }
119
120 ~Relocate()
121 {
122 if (this->skip_call_tls_get_addr_)
123 {
124 // FIXME: This needs to specify the location somehow.
125 fprintf(stderr, _("%s: missing expected TLS relocation\n"),
126 program_name);
127 gold_exit(false);
128 }
129 }
130
131 // Do a relocation. Return false if the caller should not issue
132 // any warnings about this relocation.
133 inline bool
134 relocate(const Relocate_info<32, false>*, Target_i386*, size_t relnum,
92e059d8 135 const elfcpp::Rel<32, false>&,
c06b7b0b 136 unsigned int r_type, const Sized_symbol<32>*,
b8e6aad9 137 const Symbol_value<32>*,
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138 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
139 off_t);
140
141 private:
142 // Do a TLS relocation.
ead1e424 143 inline void
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144 relocate_tls(const Relocate_info<32, false>*, size_t relnum,
145 const elfcpp::Rel<32, false>&,
c06b7b0b 146 unsigned int r_type, const Sized_symbol<32>*,
b8e6aad9 147 const Symbol_value<32>*,
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148 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr, off_t);
149
150 // Do a TLS Initial-Exec to Local-Exec transition.
151 static inline void
152 tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum,
153 Output_segment* tls_segment,
154 const elfcpp::Rel<32, false>&, unsigned int r_type,
155 elfcpp::Elf_types<32>::Elf_Addr value,
156 unsigned char* view,
157 off_t view_size);
158
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159 // Do a TLS Global-Dynamic to Local-Exec transition.
160 inline void
161 tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
162 Output_segment* tls_segment,
163 const elfcpp::Rel<32, false>&, unsigned int r_type,
164 elfcpp::Elf_types<32>::Elf_Addr value,
165 unsigned char* view,
166 off_t view_size);
167
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168 // Check the range for a TLS relocation.
169 static inline void
170 check_range(const Relocate_info<32, false>*, size_t relnum,
171 const elfcpp::Rel<32, false>&, off_t, off_t);
172
173 // Check the validity of a TLS relocation. This is like assert.
174 static inline void
175 check_tls(const Relocate_info<32, false>*, size_t relnum,
176 const elfcpp::Rel<32, false>&, bool);
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177
178 // This is set if we should skip the next reloc, which should be a
179 // PLT32 reloc against ___tls_get_addr.
180 bool skip_call_tls_get_addr_;
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181 };
182
183 // Adjust TLS relocation type based on the options and whether this
184 // is a local symbol.
185 static unsigned int
7e1edb90 186 optimize_tls_reloc(bool is_final, int r_type);
92e059d8 187
ead1e424 188 // Get the GOT section, creating it if necessary.
dbe717ef 189 Output_data_got<32, false>*
7e1edb90 190 got_section(Symbol_table*, Layout*);
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191
192 // Create a PLT entry for a global symbol.
193 void
7e1edb90 194 make_plt_entry(Symbol_table*, Layout*, Symbol*);
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195
196 // Get the PLT section.
197 Output_data_plt_i386*
198 plt_section() const
199 {
200 gold_assert(this->plt_ != NULL);
201 return this->plt_;
202 }
203
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204 // Get the dynamic reloc section, creating it if necessary.
205 Reloc_section*
206 rel_dyn_section(Layout*);
207
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208 // Copy a relocation against a global symbol.
209 void
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210 copy_reloc(const General_options*, Symbol_table*, Layout*,
211 Sized_relobj<32, false>*, unsigned int,
a3ad94ed 212 Symbol*, const elfcpp::Rel<32, false>&);
ead1e424 213
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214 // Information about this specific target which we pass to the
215 // general Target structure.
75f65a3e 216 static const Target::Target_info i386_info;
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217
218 // The GOT section.
dbe717ef 219 Output_data_got<32, false>* got_;
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220 // The PLT section.
221 Output_data_plt_i386* plt_;
222 // The GOT PLT section.
223 Output_data_space* got_plt_;
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224 // The dynamic reloc section.
225 Reloc_section* rel_dyn_;
226 // Relocs saved to avoid a COPY reloc.
227 Copy_relocs<32, false>* copy_relocs_;
228 // Space for variables copied with a COPY reloc.
229 Output_data_space* dynbss_;
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230};
231
232const Target::Target_info Target_i386::i386_info =
233{
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234 32, // size
235 false, // is_big_endian
236 elfcpp::EM_386, // machine_code
237 false, // has_make_symbol
dbe717ef 238 false, // has_resolve
c51e6221 239 true, // has_code_fill
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240 "/usr/lib/libc.so.1", // dynamic_linker
241 0x08048000, // text_segment_address
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242 0x1000, // abi_pagesize
243 0x1000 // common_pagesize
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244};
245
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246// Get the GOT section, creating it if necessary.
247
dbe717ef 248Output_data_got<32, false>*
7e1edb90 249Target_i386::got_section(Symbol_table* symtab, Layout* layout)
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250{
251 if (this->got_ == NULL)
252 {
7e1edb90 253 gold_assert(symtab != NULL && layout != NULL);
a3ad94ed 254
7e1edb90 255 this->got_ = new Output_data_got<32, false>();
ead1e424 256
ead1e424 257 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
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258 elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
259 this->got_);
ead1e424 260
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261 // The old GNU linker creates a .got.plt section. We just
262 // create another set of data in the .got section. Note that we
263 // always create a PLT if we create a GOT, although the PLT
264 // might be empty.
265 this->got_plt_ = new Output_data_space(4);
266 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
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267 elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
268 this->got_plt_);
a3ad94ed 269
ead1e424 270 // The first three entries are reserved.
a3ad94ed 271 this->got_plt_->set_space_size(3 * 4);
ead1e424 272
a3ad94ed 273 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
14b31740 274 symtab->define_in_output_data(this, "_GLOBAL_OFFSET_TABLE_", NULL,
a3ad94ed 275 this->got_plt_,
ead1e424 276 0, 0, elfcpp::STT_OBJECT,
16649710 277 elfcpp::STB_LOCAL,
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278 elfcpp::STV_HIDDEN, 0,
279 false, false);
280 }
a3ad94ed 281
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282 return this->got_;
283}
284
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285// Get the dynamic reloc section, creating it if necessary.
286
287Target_i386::Reloc_section*
288Target_i386::rel_dyn_section(Layout* layout)
289{
290 if (this->rel_dyn_ == NULL)
291 {
292 gold_assert(layout != NULL);
293 this->rel_dyn_ = new Reloc_section();
294 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
295 elfcpp::SHF_ALLOC, this->rel_dyn_);
296 }
297 return this->rel_dyn_;
298}
299
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300// A class to handle the PLT data.
301
302class Output_data_plt_i386 : public Output_section_data
303{
304 public:
305 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
306
7e1edb90 307 Output_data_plt_i386(Layout*, Output_data_space*);
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308
309 // Add an entry to the PLT.
310 void
311 add_entry(Symbol* gsym);
312
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313 // Return the .rel.plt section data.
314 const Reloc_section*
315 rel_plt() const
316 { return this->rel_; }
317
318 protected:
319 void
320 do_adjust_output_section(Output_section* os);
321
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322 private:
323 // The size of an entry in the PLT.
324 static const int plt_entry_size = 16;
325
326 // The first entry in the PLT for an executable.
327 static unsigned char exec_first_plt_entry[plt_entry_size];
328
329 // The first entry in the PLT for a shared object.
330 static unsigned char dyn_first_plt_entry[plt_entry_size];
331
332 // Other entries in the PLT for an executable.
333 static unsigned char exec_plt_entry[plt_entry_size];
334
335 // Other entries in the PLT for a shared object.
336 static unsigned char dyn_plt_entry[plt_entry_size];
337
338 // Set the final size.
339 void
340 do_set_address(uint64_t, off_t)
341 { this->set_data_size((this->count_ + 1) * plt_entry_size); }
342
343 // Write out the PLT data.
344 void
345 do_write(Output_file*);
346
347 // The reloc section.
348 Reloc_section* rel_;
349 // The .got.plt section.
350 Output_data_space* got_plt_;
351 // The number of PLT entries.
352 unsigned int count_;
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353};
354
355// Create the PLT section. The ordinary .got section is an argument,
356// since we need to refer to the start. We also create our own .got
357// section just for PLT entries.
358
359Output_data_plt_i386::Output_data_plt_i386(Layout* layout,
7e1edb90 360 Output_data_space* got_plt)
80576242 361 : Output_section_data(4), got_plt_(got_plt), count_(0)
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362{
363 this->rel_ = new Reloc_section();
364 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
365 elfcpp::SHF_ALLOC, this->rel_);
366}
367
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368// For some reason
369
370void
371Output_data_plt_i386::do_adjust_output_section(Output_section* os)
372{
373 // UnixWare sets the entsize of .plt to 4, and so does the old GNU
374 // linker, and so do we.
375 os->set_entsize(4);
376}
377
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378// Add an entry to the PLT.
379
380void
381Output_data_plt_i386::add_entry(Symbol* gsym)
382{
383 gold_assert(!gsym->has_plt_offset());
384
385 // Note that when setting the PLT offset we skip the initial
386 // reserved PLT entry.
387 gsym->set_plt_offset((this->count_ + 1) * plt_entry_size);
388
389 ++this->count_;
390
391 off_t got_offset = this->got_plt_->data_size();
392
393 // Every PLT entry needs a GOT entry which points back to the PLT
394 // entry (this will be changed by the dynamic linker, normally
395 // lazily when the function is called).
396 this->got_plt_->set_space_size(got_offset + 4);
397
398 // Every PLT entry needs a reloc.
16649710 399 gsym->set_needs_dynsym_entry();
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400 this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_,
401 got_offset);
402
403 // Note that we don't need to save the symbol. The contents of the
404 // PLT are independent of which symbols are used. The symbols only
405 // appear in the relocations.
406}
407
408// The first entry in the PLT for an executable.
409
410unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] =
411{
412 0xff, 0x35, // pushl contents of memory address
413 0, 0, 0, 0, // replaced with address of .got + 4
414 0xff, 0x25, // jmp indirect
415 0, 0, 0, 0, // replaced with address of .got + 8
416 0, 0, 0, 0 // unused
417};
418
419// The first entry in the PLT for a shared object.
420
421unsigned char Output_data_plt_i386::dyn_first_plt_entry[plt_entry_size] =
422{
423 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
424 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
425 0, 0, 0, 0 // unused
426};
427
428// Subsequent entries in the PLT for an executable.
429
430unsigned char Output_data_plt_i386::exec_plt_entry[plt_entry_size] =
431{
432 0xff, 0x25, // jmp indirect
433 0, 0, 0, 0, // replaced with address of symbol in .got
434 0x68, // pushl immediate
435 0, 0, 0, 0, // replaced with offset into relocation table
436 0xe9, // jmp relative
437 0, 0, 0, 0 // replaced with offset to start of .plt
438};
439
440// Subsequent entries in the PLT for a shared object.
441
442unsigned char Output_data_plt_i386::dyn_plt_entry[plt_entry_size] =
443{
444 0xff, 0xa3, // jmp *offset(%ebx)
445 0, 0, 0, 0, // replaced with offset of symbol in .got
446 0x68, // pushl immediate
447 0, 0, 0, 0, // replaced with offset into relocation table
448 0xe9, // jmp relative
449 0, 0, 0, 0 // replaced with offset to start of .plt
450};
451
452// Write out the PLT. This uses the hand-coded instructions above,
453// and adjusts them as needed. This is all specified by the i386 ELF
454// Processor Supplement.
455
456void
457Output_data_plt_i386::do_write(Output_file* of)
458{
459 const off_t offset = this->offset();
460 const off_t oview_size = this->data_size();
461 unsigned char* const oview = of->get_output_view(offset, oview_size);
462
463 const off_t got_file_offset = this->got_plt_->offset();
464 const off_t got_size = this->got_plt_->data_size();
465 unsigned char* const got_view = of->get_output_view(got_file_offset,
466 got_size);
467
468 unsigned char* pov = oview;
469
470 elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address();
471 elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address();
472
7e1edb90 473 if (parameters->output_is_shared())
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474 memcpy(pov, dyn_first_plt_entry, plt_entry_size);
475 else
476 {
477 memcpy(pov, exec_first_plt_entry, plt_entry_size);
478 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
479 elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
480 }
481 pov += plt_entry_size;
482
483 unsigned char* got_pov = got_view;
484
485 memset(got_pov, 0, 12);
486 got_pov += 12;
487
488 const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
489
490 unsigned int plt_offset = plt_entry_size;
491 unsigned int plt_rel_offset = 0;
492 unsigned int got_offset = 12;
493 const unsigned int count = this->count_;
494 for (unsigned int i = 0;
495 i < count;
496 ++i,
497 pov += plt_entry_size,
498 got_pov += 4,
499 plt_offset += plt_entry_size,
500 plt_rel_offset += rel_size,
501 got_offset += 4)
502 {
503 // Set and adjust the PLT entry itself.
504
7e1edb90 505 if (parameters->output_is_shared())
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506 {
507 memcpy(pov, dyn_plt_entry, plt_entry_size);
508 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
509 }
510 else
511 {
512 memcpy(pov, exec_plt_entry, plt_entry_size);
513 elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
514 (got_address
515 + got_offset));
516 }
517
518 elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
519 elfcpp::Swap<32, false>::writeval(pov + 12,
520 - (plt_offset + plt_entry_size));
521
522 // Set the entry in the GOT.
523 elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6);
524 }
525
526 gold_assert(pov - oview == oview_size);
527 gold_assert(got_pov - got_view == got_size);
528
529 of->write_output_view(offset, oview_size, oview);
530 of->write_output_view(got_file_offset, got_size, got_view);
531}
532
533// Create a PLT entry for a global symbol.
534
535void
7e1edb90 536Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym)
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537{
538 if (gsym->has_plt_offset())
539 return;
540
541 if (this->plt_ == NULL)
542 {
543 // Create the GOT sections first.
7e1edb90 544 this->got_section(symtab, layout);
a3ad94ed 545
7e1edb90 546 this->plt_ = new Output_data_plt_i386(layout, this->got_plt_);
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547 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
548 (elfcpp::SHF_ALLOC
549 | elfcpp::SHF_EXECINSTR),
550 this->plt_);
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551 }
552
553 this->plt_->add_entry(gsym);
554}
555
556// Handle a relocation against a non-function symbol defined in a
557// dynamic object. The traditional way to handle this is to generate
558// a COPY relocation to copy the variable at runtime from the shared
559// object into the executable's data segment. However, this is
560// undesirable in general, as if the size of the object changes in the
561// dynamic object, the executable will no longer work correctly. If
562// this relocation is in a writable section, then we can create a
563// dynamic reloc and the dynamic linker will resolve it to the correct
564// address at runtime. However, we do not want do that if the
565// relocation is in a read-only section, as it would prevent the
566// readonly segment from being shared. And if we have to eventually
567// generate a COPY reloc, then any dynamic relocations will be
568// useless. So this means that if this is a writable section, we need
569// to save the relocation until we see whether we have to create a
570// COPY relocation for this symbol for any other relocation.
571
572void
573Target_i386::copy_reloc(const General_options* options,
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574 Symbol_table* symtab,
575 Layout* layout,
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576 Sized_relobj<32, false>* object,
577 unsigned int data_shndx, Symbol* gsym,
5a6f7e2d 578 const elfcpp::Rel<32, false>& rel)
a3ad94ed 579{
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580 Sized_symbol<32>* ssym;
581 ssym = symtab->get_sized_symbol SELECT_SIZE_NAME(32) (gsym
582 SELECT_SIZE(32));
583
584 if (!Copy_relocs<32, false>::need_copy_reloc(options, object,
585 data_shndx, ssym))
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586 {
587 // So far we do not need a COPY reloc. Save this relocation.
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588 // If it turns out that we never need a COPY reloc for this
589 // symbol, then we will emit the relocation.
590 if (this->copy_relocs_ == NULL)
591 this->copy_relocs_ = new Copy_relocs<32, false>();
592 this->copy_relocs_->save(ssym, object, data_shndx, rel);
a3ad94ed 593 }
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594 else
595 {
596 // Allocate space for this symbol in the .bss section.
597
598 elfcpp::Elf_types<32>::Elf_WXword symsize = ssym->symsize();
599
600 // There is no defined way to determine the required alignment
601 // of the symbol. We pick the alignment based on the size. We
602 // set an arbitrary maximum of 256.
603 unsigned int align;
604 for (align = 1; align < 512; align <<= 1)
605 if ((symsize & align) != 0)
606 break;
a3ad94ed 607
5a6f7e2d
ILT
608 if (this->dynbss_ == NULL)
609 {
610 this->dynbss_ = new Output_data_space(align);
611 layout->add_output_section_data(".bss",
612 elfcpp::SHT_NOBITS,
613 (elfcpp::SHF_ALLOC
614 | elfcpp::SHF_WRITE),
615 this->dynbss_);
616 }
617
618 Output_data_space* dynbss = this->dynbss_;
619
620 if (align > dynbss->addralign())
621 dynbss->set_space_alignment(align);
622
623 off_t dynbss_size = dynbss->data_size();
624 dynbss_size = align_address(dynbss_size, align);
625 off_t offset = dynbss_size;
626 dynbss->set_space_size(dynbss_size + symsize);
627
628 // Define the symbol in the .dynbss section.
14b31740
ILT
629 symtab->define_in_output_data(this, ssym->name(), ssym->version(),
630 dynbss, offset, symsize, ssym->type(),
631 ssym->binding(), ssym->visibility(),
632 ssym->nonvis(), false, false);
5a6f7e2d
ILT
633
634 // Add the COPY reloc.
16649710 635 ssym->set_needs_dynsym_entry();
5a6f7e2d
ILT
636 Reloc_section* rel_dyn = this->rel_dyn_section(layout);
637 rel_dyn->add_global(ssym, elfcpp::R_386_COPY, dynbss, offset);
638 }
a3ad94ed
ILT
639}
640
92e059d8 641// Optimize the TLS relocation type based on what we know about the
a3ad94ed
ILT
642// symbol. IS_FINAL is true if the final address of this symbol is
643// known at link time.
92e059d8
ILT
644
645unsigned int
7e1edb90 646Target_i386::optimize_tls_reloc(bool is_final, int r_type)
92e059d8
ILT
647{
648 // If we are generating a shared library, then we can't do anything
649 // in the linker.
7e1edb90 650 if (parameters->output_is_shared())
92e059d8
ILT
651 return r_type;
652
653 switch (r_type)
654 {
655 case elfcpp::R_386_TLS_GD:
656 case elfcpp::R_386_TLS_GOTDESC:
657 case elfcpp::R_386_TLS_DESC_CALL:
658 // These are Global-Dynamic which permits fully general TLS
659 // access. Since we know that we are generating an executable,
660 // we can convert this to Initial-Exec. If we also know that
661 // this is a local symbol, we can further switch to Local-Exec.
a3ad94ed 662 if (is_final)
92e059d8
ILT
663 return elfcpp::R_386_TLS_LE_32;
664 return elfcpp::R_386_TLS_IE_32;
665
666 case elfcpp::R_386_TLS_LDM:
667 // This is Local-Dynamic, which refers to a local symbol in the
668 // dynamic TLS block. Since we know that we generating an
669 // executable, we can switch to Local-Exec.
670 return elfcpp::R_386_TLS_LE_32;
671
672 case elfcpp::R_386_TLS_LDO_32:
673 // Another type of Local-Dynamic relocation.
674 return elfcpp::R_386_TLS_LE;
675
676 case elfcpp::R_386_TLS_IE:
677 case elfcpp::R_386_TLS_GOTIE:
678 case elfcpp::R_386_TLS_IE_32:
679 // These are Initial-Exec relocs which get the thread offset
680 // from the GOT. If we know that we are linking against the
681 // local symbol, we can switch to Local-Exec, which links the
682 // thread offset into the instruction.
a3ad94ed 683 if (is_final)
92e059d8
ILT
684 return elfcpp::R_386_TLS_LE_32;
685 return r_type;
8462ae85 686
92e059d8
ILT
687 case elfcpp::R_386_TLS_LE:
688 case elfcpp::R_386_TLS_LE_32:
689 // When we already have Local-Exec, there is nothing further we
690 // can do.
691 return r_type;
692
693 default:
a3ad94ed 694 gold_unreachable();
92e059d8
ILT
695 }
696}
697
698// Scan a relocation for a local symbol.
699
700inline void
7e1edb90 701Target_i386::Scan::local(const General_options&,
ead1e424
ILT
702 Symbol_table* symtab,
703 Layout* layout,
704 Target_i386* target,
f6ce93d6 705 Sized_relobj<32, false>* object,
a3ad94ed
ILT
706 unsigned int,
707 const elfcpp::Rel<32, false>&,
708 unsigned int r_type,
92e059d8
ILT
709 const elfcpp::Sym<32, false>&)
710{
711 switch (r_type)
712 {
713 case elfcpp::R_386_NONE:
714 case elfcpp::R_386_GNU_VTINHERIT:
715 case elfcpp::R_386_GNU_VTENTRY:
716 break;
717
718 case elfcpp::R_386_32:
719 case elfcpp::R_386_16:
720 case elfcpp::R_386_8:
721 // FIXME: If we are generating a shared object we need to copy
722 // this relocation into the object.
7e1edb90 723 gold_assert(!parameters->output_is_shared());
92e059d8
ILT
724 break;
725
726 case elfcpp::R_386_PC32:
727 case elfcpp::R_386_PC16:
728 case elfcpp::R_386_PC8:
729 break;
730
ead1e424
ILT
731 case elfcpp::R_386_GOTOFF:
732 case elfcpp::R_386_GOTPC:
733 // We need a GOT section.
7e1edb90 734 target->got_section(symtab, layout);
ead1e424
ILT
735 break;
736
92e059d8
ILT
737 case elfcpp::R_386_COPY:
738 case elfcpp::R_386_GLOB_DAT:
739 case elfcpp::R_386_JUMP_SLOT:
740 case elfcpp::R_386_RELATIVE:
741 case elfcpp::R_386_TLS_TPOFF:
742 case elfcpp::R_386_TLS_DTPMOD32:
743 case elfcpp::R_386_TLS_DTPOFF32:
744 case elfcpp::R_386_TLS_TPOFF32:
745 case elfcpp::R_386_TLS_DESC:
746 fprintf(stderr, _("%s: %s: unexpected reloc %u in object file\n"),
747 program_name, object->name().c_str(), r_type);
748 gold_exit(false);
749 break;
750
751 case elfcpp::R_386_TLS_IE:
752 case elfcpp::R_386_TLS_GOTIE:
753 case elfcpp::R_386_TLS_LE:
754 case elfcpp::R_386_TLS_GD:
755 case elfcpp::R_386_TLS_LDM:
756 case elfcpp::R_386_TLS_LDO_32:
757 case elfcpp::R_386_TLS_IE_32:
758 case elfcpp::R_386_TLS_LE_32:
759 case elfcpp::R_386_TLS_GOTDESC:
760 case elfcpp::R_386_TLS_DESC_CALL:
7e1edb90 761 {
80576242
ILT
762 bool output_is_shared = parameters->output_is_shared();
763 r_type = Target_i386::optimize_tls_reloc(!output_is_shared,
7e1edb90
ILT
764 r_type);
765 switch (r_type)
766 {
767 case elfcpp::R_386_TLS_LE:
768 case elfcpp::R_386_TLS_LE_32:
769 // FIXME: If generating a shared object, we need to copy
770 // this relocation into the object.
80576242 771 gold_assert(!output_is_shared);
7e1edb90 772 break;
92e059d8 773
7e1edb90
ILT
774 case elfcpp::R_386_TLS_IE:
775 case elfcpp::R_386_TLS_GOTIE:
776 case elfcpp::R_386_TLS_GD:
777 case elfcpp::R_386_TLS_LDM:
778 case elfcpp::R_386_TLS_LDO_32:
779 case elfcpp::R_386_TLS_IE_32:
780 case elfcpp::R_386_TLS_GOTDESC:
781 case elfcpp::R_386_TLS_DESC_CALL:
782 fprintf(stderr,
783 _("%s: %s: unsupported reloc %u against local symbol\n"),
784 program_name, object->name().c_str(), r_type);
785 break;
786 }
787 }
92e059d8
ILT
788 break;
789
790 case elfcpp::R_386_GOT32:
791 case elfcpp::R_386_PLT32:
92e059d8
ILT
792 case elfcpp::R_386_32PLT:
793 case elfcpp::R_386_TLS_GD_32:
794 case elfcpp::R_386_TLS_GD_PUSH:
795 case elfcpp::R_386_TLS_GD_CALL:
796 case elfcpp::R_386_TLS_GD_POP:
797 case elfcpp::R_386_TLS_LDM_32:
798 case elfcpp::R_386_TLS_LDM_PUSH:
799 case elfcpp::R_386_TLS_LDM_CALL:
800 case elfcpp::R_386_TLS_LDM_POP:
801 case elfcpp::R_386_USED_BY_INTEL_200:
802 default:
803 fprintf(stderr, _("%s: %s: unsupported reloc %u against local symbol\n"),
804 program_name, object->name().c_str(), r_type);
805 break;
806 }
807}
808
809// Scan a relocation for a global symbol.
810
811inline void
812Target_i386::Scan::global(const General_options& options,
ead1e424
ILT
813 Symbol_table* symtab,
814 Layout* layout,
815 Target_i386* target,
f6ce93d6 816 Sized_relobj<32, false>* object,
a3ad94ed
ILT
817 unsigned int data_shndx,
818 const elfcpp::Rel<32, false>& reloc,
819 unsigned int r_type,
92e059d8
ILT
820 Symbol* gsym)
821{
822 switch (r_type)
823 {
824 case elfcpp::R_386_NONE:
825 case elfcpp::R_386_GNU_VTINHERIT:
8462ae85 826 case elfcpp::R_386_GNU_VTENTRY:
92e059d8
ILT
827 break;
828
829 case elfcpp::R_386_32:
830 case elfcpp::R_386_PC32:
831 case elfcpp::R_386_16:
832 case elfcpp::R_386_PC16:
833 case elfcpp::R_386_8:
834 case elfcpp::R_386_PC8:
835 // FIXME: If we are generating a shared object we may need to
836 // copy this relocation into the object. If this symbol is
837 // defined in a shared object, we may need to copy this
838 // relocation in order to avoid a COPY relocation.
7e1edb90 839 gold_assert(!parameters->output_is_shared());
a3ad94ed 840
14b31740 841 if (gsym->is_from_dynobj())
a3ad94ed
ILT
842 {
843 // This symbol is defined in a dynamic object. If it is a
844 // function, we make a PLT entry. Otherwise we need to
845 // either generate a COPY reloc or copy this reloc.
846 if (gsym->type() == elfcpp::STT_FUNC)
7e1edb90 847 target->make_plt_entry(symtab, layout, gsym);
a3ad94ed 848 else
5a6f7e2d
ILT
849 target->copy_reloc(&options, symtab, layout, object, data_shndx,
850 gsym, reloc);
a3ad94ed
ILT
851 }
852
92e059d8
ILT
853 break;
854
ead1e424 855 case elfcpp::R_386_GOT32:
8462ae85
ILT
856 {
857 // The symbol requires a GOT entry.
7e1edb90 858 Output_data_got<32, false>* got = target->got_section(symtab, layout);
8462ae85
ILT
859 if (got->add_global(gsym))
860 {
861 // If this symbol is not fully resolved, we need to add a
862 // dynamic relocation for it.
7e1edb90 863 if (!gsym->final_value_is_known())
8462ae85
ILT
864 {
865 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
866 rel_dyn->add_global(gsym, elfcpp::R_386_GLOB_DAT, got,
867 gsym->got_offset());
868 }
869 }
870 }
ead1e424
ILT
871 break;
872
873 case elfcpp::R_386_PLT32:
a3ad94ed
ILT
874 // If the symbol is fully resolved, this is just a PC32 reloc.
875 // Otherwise we need a PLT entry.
7e1edb90 876 if (gsym->final_value_is_known())
ead1e424 877 break;
7e1edb90 878 target->make_plt_entry(symtab, layout, gsym);
ead1e424
ILT
879 break;
880
881 case elfcpp::R_386_GOTOFF:
882 case elfcpp::R_386_GOTPC:
883 // We need a GOT section.
7e1edb90 884 target->got_section(symtab, layout);
ead1e424
ILT
885 break;
886
92e059d8
ILT
887 case elfcpp::R_386_COPY:
888 case elfcpp::R_386_GLOB_DAT:
889 case elfcpp::R_386_JUMP_SLOT:
890 case elfcpp::R_386_RELATIVE:
891 case elfcpp::R_386_TLS_TPOFF:
892 case elfcpp::R_386_TLS_DTPMOD32:
893 case elfcpp::R_386_TLS_DTPOFF32:
894 case elfcpp::R_386_TLS_TPOFF32:
895 case elfcpp::R_386_TLS_DESC:
896 fprintf(stderr, _("%s: %s: unexpected reloc %u in object file\n"),
897 program_name, object->name().c_str(), r_type);
898 gold_exit(false);
899 break;
900
901 case elfcpp::R_386_TLS_IE:
902 case elfcpp::R_386_TLS_GOTIE:
903 case elfcpp::R_386_TLS_LE:
904 case elfcpp::R_386_TLS_GD:
905 case elfcpp::R_386_TLS_LDM:
906 case elfcpp::R_386_TLS_LDO_32:
907 case elfcpp::R_386_TLS_IE_32:
908 case elfcpp::R_386_TLS_LE_32:
909 case elfcpp::R_386_TLS_GOTDESC:
910 case elfcpp::R_386_TLS_DESC_CALL:
a3ad94ed 911 {
7e1edb90
ILT
912 const bool is_final = gsym->final_value_is_known();
913 r_type = Target_i386::optimize_tls_reloc(is_final, r_type);
a3ad94ed
ILT
914 switch (r_type)
915 {
916 case elfcpp::R_386_TLS_LE:
917 case elfcpp::R_386_TLS_LE_32:
918 // FIXME: If generating a shared object, we need to copy
919 // this relocation into the object.
7e1edb90 920 gold_assert(!parameters->output_is_shared());
a3ad94ed
ILT
921 break;
922
923 case elfcpp::R_386_TLS_IE:
924 case elfcpp::R_386_TLS_GOTIE:
925 case elfcpp::R_386_TLS_GD:
926 case elfcpp::R_386_TLS_LDM:
927 case elfcpp::R_386_TLS_LDO_32:
928 case elfcpp::R_386_TLS_IE_32:
929 case elfcpp::R_386_TLS_GOTDESC:
930 case elfcpp::R_386_TLS_DESC_CALL:
931 fprintf(stderr,
932 _("%s: %s: unsupported reloc %u "
933 "against global symbol %s\n"),
934 program_name, object->name().c_str(), r_type,
935 gsym->name());
936 break;
937 }
938 }
92e059d8
ILT
939 break;
940
92e059d8
ILT
941 case elfcpp::R_386_32PLT:
942 case elfcpp::R_386_TLS_GD_32:
943 case elfcpp::R_386_TLS_GD_PUSH:
944 case elfcpp::R_386_TLS_GD_CALL:
945 case elfcpp::R_386_TLS_GD_POP:
946 case elfcpp::R_386_TLS_LDM_32:
947 case elfcpp::R_386_TLS_LDM_PUSH:
948 case elfcpp::R_386_TLS_LDM_CALL:
949 case elfcpp::R_386_TLS_LDM_POP:
950 case elfcpp::R_386_USED_BY_INTEL_200:
951 default:
952 fprintf(stderr,
953 _("%s: %s: unsupported reloc %u against global symbol %s\n"),
954 program_name, object->name().c_str(), r_type, gsym->name());
955 break;
956 }
957}
958
959// Scan relocations for a section.
960
961void
962Target_i386::scan_relocs(const General_options& options,
963 Symbol_table* symtab,
ead1e424 964 Layout* layout,
f6ce93d6 965 Sized_relobj<32, false>* object,
a3ad94ed 966 unsigned int data_shndx,
92e059d8
ILT
967 unsigned int sh_type,
968 const unsigned char* prelocs,
969 size_t reloc_count,
970 size_t local_symbol_count,
971 const unsigned char* plocal_symbols,
972 Symbol** global_symbols)
973{
974 if (sh_type == elfcpp::SHT_RELA)
975 {
976 fprintf(stderr, _("%s: %s: unsupported RELA reloc section\n"),
977 program_name, object->name().c_str());
978 gold_exit(false);
979 }
980
ead1e424
ILT
981 gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL,
982 Target_i386::Scan>(
92e059d8
ILT
983 options,
984 symtab,
ead1e424
ILT
985 layout,
986 this,
92e059d8 987 object,
a3ad94ed 988 data_shndx,
92e059d8
ILT
989 prelocs,
990 reloc_count,
991 local_symbol_count,
992 plocal_symbols,
993 global_symbols);
994}
995
16649710 996// Finalize the sections.
5a6f7e2d
ILT
997
998void
7e1edb90 999Target_i386::do_finalize_sections(Layout* layout)
5a6f7e2d 1000{
16649710
ILT
1001 // Fill in some more dynamic tags.
1002 Output_data_dynamic* const odyn = layout->dynamic_data();
1003 if (odyn != NULL)
1004 {
1005 if (this->got_plt_ != NULL)
1006 odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_);
1007
1008 if (this->plt_ != NULL)
1009 {
1010 const Output_data* od = this->plt_->rel_plt();
1011 odyn->add_section_size(elfcpp::DT_PLTRELSZ, od);
1012 odyn->add_section_address(elfcpp::DT_JMPREL, od);
1013 odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_REL);
1014 }
1015
1016 if (this->rel_dyn_ != NULL)
1017 {
1018 const Output_data* od = this->rel_dyn_;
1019 odyn->add_section_address(elfcpp::DT_REL, od);
1020 odyn->add_section_size(elfcpp::DT_RELSZ, od);
1021 odyn->add_constant(elfcpp::DT_RELENT,
1022 elfcpp::Elf_sizes<32>::rel_size);
1023 }
1024
7e1edb90 1025 if (!parameters->output_is_shared())
16649710
ILT
1026 {
1027 // The value of the DT_DEBUG tag is filled in by the dynamic
1028 // linker at run time, and used by the debugger.
1029 odyn->add_constant(elfcpp::DT_DEBUG, 0);
1030 }
1031 }
1032
1033 // Emit any relocs we saved in an attempt to avoid generating COPY
1034 // relocs.
5a6f7e2d
ILT
1035 if (this->copy_relocs_ == NULL)
1036 return;
1037 if (this->copy_relocs_->any_to_emit())
1038 {
1039 Reloc_section* rel_dyn = this->rel_dyn_section(layout);
1040 this->copy_relocs_->emit(rel_dyn);
1041 }
1042 delete this->copy_relocs_;
1043 this->copy_relocs_ = NULL;
1044}
1045
61ba1cf9
ILT
1046// Perform a relocation.
1047
ead1e424 1048inline bool
92e059d8 1049Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
ead1e424 1050 Target_i386* target,
92e059d8
ILT
1051 size_t relnum,
1052 const elfcpp::Rel<32, false>& rel,
1053 unsigned int r_type,
c06b7b0b 1054 const Sized_symbol<32>* gsym,
b8e6aad9 1055 const Symbol_value<32>* psymval,
92e059d8
ILT
1056 unsigned char* view,
1057 elfcpp::Elf_types<32>::Elf_Addr address,
1058 off_t view_size)
61ba1cf9 1059{
ead1e424
ILT
1060 if (this->skip_call_tls_get_addr_)
1061 {
1062 if (r_type != elfcpp::R_386_PLT32
1063 || gsym == NULL
1064 || strcmp(gsym->name(), "___tls_get_addr") != 0)
1065 {
1066 fprintf(stderr, _("%s: %s: missing expected TLS relocation\n"),
1067 program_name,
1068 relinfo->location(relnum, rel.get_r_offset()).c_str());
1069 gold_exit(false);
1070 }
1071
1072 this->skip_call_tls_get_addr_ = false;
1073
1074 return false;
1075 }
1076
a3ad94ed 1077 // Pick the value to use for symbols defined in shared objects.
b8e6aad9 1078 Symbol_value<32> symval;
8462ae85 1079 if (gsym != NULL && gsym->is_from_dynobj() && gsym->has_plt_offset())
a3ad94ed 1080 {
b8e6aad9
ILT
1081 symval.set_output_value(target->plt_section()->address()
1082 + gsym->plt_offset());
1083 psymval = &symval;
a3ad94ed
ILT
1084 }
1085
b8e6aad9
ILT
1086 const Sized_relobj<32, false>* object = relinfo->object;
1087
61ba1cf9
ILT
1088 switch (r_type)
1089 {
1090 case elfcpp::R_386_NONE:
92e059d8
ILT
1091 case elfcpp::R_386_GNU_VTINHERIT:
1092 case elfcpp::R_386_GNU_VTENTRY:
61ba1cf9
ILT
1093 break;
1094
1095 case elfcpp::R_386_32:
b8e6aad9 1096 Relocate_functions<32, false>::rel32(view, object, psymval);
61ba1cf9
ILT
1097 break;
1098
1099 case elfcpp::R_386_PC32:
b8e6aad9 1100 Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
92e059d8
ILT
1101 break;
1102
1103 case elfcpp::R_386_16:
b8e6aad9 1104 Relocate_functions<32, false>::rel16(view, object, psymval);
92e059d8
ILT
1105 break;
1106
1107 case elfcpp::R_386_PC16:
b8e6aad9 1108 Relocate_functions<32, false>::pcrel16(view, object, psymval, address);
61ba1cf9
ILT
1109 break;
1110
92e059d8 1111 case elfcpp::R_386_8:
b8e6aad9 1112 Relocate_functions<32, false>::rel8(view, object, psymval);
92e059d8
ILT
1113 break;
1114
1115 case elfcpp::R_386_PC8:
b8e6aad9 1116 Relocate_functions<32, false>::pcrel8(view, object, psymval, address);
92e059d8
ILT
1117 break;
1118
ead1e424 1119 case elfcpp::R_386_PLT32:
a3ad94ed 1120 gold_assert(gsym->has_plt_offset()
7e1edb90 1121 || gsym->final_value_is_known());
b8e6aad9 1122 Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
ead1e424
ILT
1123 break;
1124
1125 case elfcpp::R_386_GOT32:
1126 // Local GOT offsets not yet supported.
a3ad94ed
ILT
1127 gold_assert(gsym);
1128 gold_assert(gsym->has_got_offset());
b8e6aad9 1129 Relocate_functions<32, false>::rel32(view, gsym->got_offset());
ead1e424
ILT
1130 break;
1131
1132 case elfcpp::R_386_GOTOFF:
b8e6aad9
ILT
1133 {
1134 elfcpp::Elf_types<32>::Elf_Addr value;
1135 value = (psymval->value(object, 0)
7e1edb90 1136 - target->got_section(NULL, NULL)->address());
b8e6aad9
ILT
1137 Relocate_functions<32, false>::rel32(view, value);
1138 }
ead1e424
ILT
1139 break;
1140
1141 case elfcpp::R_386_GOTPC:
b8e6aad9
ILT
1142 {
1143 elfcpp::Elf_types<32>::Elf_Addr value;
7e1edb90 1144 value = target->got_section(NULL, NULL)->address();
b8e6aad9
ILT
1145 Relocate_functions<32, false>::pcrel32(view, value, address);
1146 }
ead1e424
ILT
1147 break;
1148
92e059d8
ILT
1149 case elfcpp::R_386_COPY:
1150 case elfcpp::R_386_GLOB_DAT:
1151 case elfcpp::R_386_JUMP_SLOT:
1152 case elfcpp::R_386_RELATIVE:
1153 case elfcpp::R_386_TLS_TPOFF:
1154 case elfcpp::R_386_TLS_DTPMOD32:
1155 case elfcpp::R_386_TLS_DTPOFF32:
1156 case elfcpp::R_386_TLS_TPOFF32:
1157 case elfcpp::R_386_TLS_DESC:
1158 fprintf(stderr, _("%s: %s: unexpected reloc %u in object file\n"),
1159 program_name,
1160 relinfo->location(relnum, rel.get_r_offset()).c_str(),
1161 r_type);
1162 gold_exit(false);
1163 break;
1164
1165 case elfcpp::R_386_TLS_IE:
1166 case elfcpp::R_386_TLS_GOTIE:
1167 case elfcpp::R_386_TLS_LE:
1168 case elfcpp::R_386_TLS_GD:
1169 case elfcpp::R_386_TLS_LDM:
1170 case elfcpp::R_386_TLS_LDO_32:
1171 case elfcpp::R_386_TLS_IE_32:
1172 case elfcpp::R_386_TLS_LE_32:
1173 case elfcpp::R_386_TLS_GOTDESC:
1174 case elfcpp::R_386_TLS_DESC_CALL:
b8e6aad9 1175 this->relocate_tls(relinfo, relnum, rel, r_type, gsym, psymval, view,
ead1e424 1176 address, view_size);
92e059d8
ILT
1177 break;
1178
92e059d8
ILT
1179 case elfcpp::R_386_32PLT:
1180 case elfcpp::R_386_TLS_GD_32:
1181 case elfcpp::R_386_TLS_GD_PUSH:
1182 case elfcpp::R_386_TLS_GD_CALL:
1183 case elfcpp::R_386_TLS_GD_POP:
1184 case elfcpp::R_386_TLS_LDM_32:
1185 case elfcpp::R_386_TLS_LDM_PUSH:
1186 case elfcpp::R_386_TLS_LDM_CALL:
1187 case elfcpp::R_386_TLS_LDM_POP:
1188 case elfcpp::R_386_USED_BY_INTEL_200:
61ba1cf9
ILT
1189 default:
1190 fprintf(stderr, _("%s: %s: unsupported reloc %u\n"),
92e059d8
ILT
1191 program_name,
1192 relinfo->location(relnum, rel.get_r_offset()).c_str(),
1193 r_type);
61ba1cf9 1194 // gold_exit(false);
92e059d8
ILT
1195 break;
1196 }
ead1e424
ILT
1197
1198 return true;
92e059d8
ILT
1199}
1200
1201// Perform a TLS relocation.
1202
1203inline void
1204Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo,
1205 size_t relnum,
1206 const elfcpp::Rel<32, false>& rel,
1207 unsigned int r_type,
c06b7b0b 1208 const Sized_symbol<32>* gsym,
b8e6aad9 1209 const Symbol_value<32>* psymval,
92e059d8
ILT
1210 unsigned char* view,
1211 elfcpp::Elf_types<32>::Elf_Addr,
1212 off_t view_size)
1213{
1214 Output_segment* tls_segment = relinfo->layout->tls_segment();
1215 if (tls_segment == NULL)
1216 {
1217 fprintf(stderr, _("%s: %s: TLS reloc but no TLS segment\n"),
1218 program_name,
1219 relinfo->location(relnum, rel.get_r_offset()).c_str());
1220 gold_exit(false);
1221 }
1222
b8e6aad9
ILT
1223 elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(relinfo->object, 0);
1224
a3ad94ed 1225 const bool is_final = (gsym == NULL
7e1edb90
ILT
1226 ? !parameters->output_is_shared()
1227 : gsym->final_value_is_known());
92e059d8 1228 const unsigned int opt_r_type =
7e1edb90 1229 Target_i386::optimize_tls_reloc(is_final, r_type);
92e059d8
ILT
1230 switch (r_type)
1231 {
1232 case elfcpp::R_386_TLS_LE_32:
1233 value = tls_segment->vaddr() + tls_segment->memsz() - value;
1234 Relocate_functions<32, false>::rel32(view, value);
1235 break;
1236
1237 case elfcpp::R_386_TLS_LE:
1238 value = value - (tls_segment->vaddr() + tls_segment->memsz());
1239 Relocate_functions<32, false>::rel32(view, value);
1240 break;
1241
1242 case elfcpp::R_386_TLS_IE:
1243 case elfcpp::R_386_TLS_GOTIE:
1244 case elfcpp::R_386_TLS_IE_32:
1245 if (opt_r_type == elfcpp::R_386_TLS_LE_32)
1246 {
1247 Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
1248 rel, r_type, value, view,
1249 view_size);
1250 break;
1251 }
1252 fprintf(stderr, _("%s: %s: unsupported reloc type %u\n"),
1253 program_name,
1254 relinfo->location(relnum, rel.get_r_offset()).c_str(),
1255 r_type);
1256 // gold_exit(false);
1257 break;
1258
1259 case elfcpp::R_386_TLS_GD:
ead1e424
ILT
1260 if (opt_r_type == elfcpp::R_386_TLS_LE_32)
1261 {
1262 this->tls_gd_to_le(relinfo, relnum, tls_segment,
1263 rel, r_type, value, view,
1264 view_size);
1265 break;
1266 }
1267 fprintf(stderr, _("%s: %s: unsupported reloc %u\n"),
1268 program_name,
1269 relinfo->location(relnum, rel.get_r_offset()).c_str(),
1270 r_type);
1271 // gold_exit(false);
1272 break;
1273
92e059d8
ILT
1274 case elfcpp::R_386_TLS_LDM:
1275 case elfcpp::R_386_TLS_LDO_32:
1276 case elfcpp::R_386_TLS_GOTDESC:
1277 case elfcpp::R_386_TLS_DESC_CALL:
1278 fprintf(stderr, _("%s: %s: unsupported reloc %u\n"),
1279 program_name,
1280 relinfo->location(relnum, rel.get_r_offset()).c_str(),
1281 r_type);
1282 // gold_exit(false);
1283 break;
1284 }
1285}
1286
1287// Do a relocation in which we convert a TLS Initial-Exec to a
1288// Local-Exec.
1289
1290inline void
1291Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo,
1292 size_t relnum,
1293 Output_segment* tls_segment,
1294 const elfcpp::Rel<32, false>& rel,
1295 unsigned int r_type,
1296 elfcpp::Elf_types<32>::Elf_Addr value,
1297 unsigned char* view,
1298 off_t view_size)
1299{
1300 // We have to actually change the instructions, which means that we
1301 // need to examine the opcodes to figure out which instruction we
1302 // are looking at.
1303 if (r_type == elfcpp::R_386_TLS_IE)
1304 {
1305 // movl %gs:XX,%eax ==> movl $YY,%eax
1306 // movl %gs:XX,%reg ==> movl $YY,%reg
1307 // addl %gs:XX,%reg ==> addl $YY,%reg
1308 Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, -1);
1309 Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, 4);
1310
1311 unsigned char op1 = view[-1];
1312 if (op1 == 0xa1)
1313 {
1314 // movl XX,%eax ==> movl $YY,%eax
1315 view[-1] = 0xb8;
1316 }
1317 else
1318 {
1319 Target_i386::Relocate::check_range(relinfo, relnum, rel,
1320 view_size, -2);
1321
1322 unsigned char op2 = view[-2];
1323 if (op2 == 0x8b)
1324 {
1325 // movl XX,%reg ==> movl $YY,%reg
1326 Target_i386::Relocate::check_tls(relinfo, relnum, rel,
1327 (op1 & 0xc7) == 0x05);
1328 view[-2] = 0xc7;
1329 view[-1] = 0xc0 | ((op1 >> 3) & 7);
1330 }
1331 else if (op2 == 0x03)
1332 {
1333 // addl XX,%reg ==> addl $YY,%reg
1334 Target_i386::Relocate::check_tls(relinfo, relnum, rel,
1335 (op1 & 0xc7) == 0x05);
1336 view[-2] = 0x81;
1337 view[-1] = 0xc0 | ((op1 >> 3) & 7);
1338 }
1339 else
1340 Target_i386::Relocate::check_tls(relinfo, relnum, rel, 0);
1341 }
1342 }
1343 else
1344 {
1345 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
1346 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
1347 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
1348 Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, -2);
1349 Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, 4);
1350
1351 unsigned char op1 = view[-1];
1352 unsigned char op2 = view[-2];
1353 Target_i386::Relocate::check_tls(relinfo, relnum, rel,
1354 (op1 & 0xc0) == 0x80 && (op1 & 7) != 4);
1355 if (op2 == 0x8b)
1356 {
1357 // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
1358 view[-2] = 0xc7;
1359 view[-1] = 0xc0 | ((op1 >> 3) & 7);
1360 }
1361 else if (op2 == 0x2b)
1362 {
1363 // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
1364 view[-2] = 0x81;
1365 view[-1] = 0xe8 | ((op1 >> 3) & 7);
1366 }
1367 else if (op2 == 0x03)
1368 {
1369 // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
1370 view[-2] = 0x81;
1371 view[-1] = 0xc0 | ((op1 >> 3) & 7);
1372 }
1373 else
1374 Target_i386::Relocate::check_tls(relinfo, relnum, rel, 0);
1375 }
1376
ead1e424
ILT
1377 value = tls_segment->vaddr() + tls_segment->memsz() - value;
1378 if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE)
1379 value = - value;
92e059d8
ILT
1380
1381 Relocate_functions<32, false>::rel32(view, value);
1382}
1383
ead1e424
ILT
1384// Do a relocation in which we convert a TLS Global-Dynamic to a
1385// Local-Exec.
1386
1387inline void
1388Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo,
1389 size_t relnum,
1390 Output_segment* tls_segment,
1391 const elfcpp::Rel<32, false>& rel,
1392 unsigned int,
1393 elfcpp::Elf_types<32>::Elf_Addr value,
1394 unsigned char* view,
1395 off_t view_size)
1396{
1397 // leal foo(,%reg,1),%eax; call ___tls_get_addr
1398 // ==> movl %gs,0,%eax; subl $foo@tpoff,%eax
1399 // leal foo(%reg),%eax; call ___tls_get_addr
1400 // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
1401
1402 Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, -2);
1403 Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, 9);
1404
1405 unsigned char op1 = view[-1];
1406 unsigned char op2 = view[-2];
1407
1408 Target_i386::Relocate::check_tls(relinfo, relnum, rel,
1409 op2 == 0x8d || op2 == 0x04);
1410 Target_i386::Relocate::check_tls(relinfo, relnum, rel,
1411 view[4] == 0xe8);
1412
1413 int roff = 5;
1414
1415 if (op2 == 0x04)
1416 {
1417 Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, -3);
1418 Target_i386::Relocate::check_tls(relinfo, relnum, rel,
1419 view[-3] == 0x8d);
1420 Target_i386::Relocate::check_tls(relinfo, relnum, rel,
1421 ((op1 & 0xc7) == 0x05
1422 && op1 != (4 << 3)));
1423 memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
1424 }
1425 else
1426 {
1427 Target_i386::Relocate::check_tls(relinfo, relnum, rel,
1428 (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
1429 if (rel.get_r_offset() + 9 < view_size && view[9] == 0x90)
1430 {
1431 // There is a trailing nop. Use the size byte subl.
1432 memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
1433 roff = 6;
1434 }
1435 else
1436 {
1437 // Use the five byte subl.
1438 memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
1439 }
1440 }
1441
1442 value = tls_segment->vaddr() + tls_segment->memsz() - value;
1443 Relocate_functions<32, false>::rel32(view + roff, value);
1444
1445 // The next reloc should be a PLT32 reloc against __tls_get_addr.
1446 // We can skip it.
1447 this->skip_call_tls_get_addr_ = true;
1448}
1449
92e059d8
ILT
1450// Check the range for a TLS relocation.
1451
1452inline void
1453Target_i386::Relocate::check_range(const Relocate_info<32, false>* relinfo,
1454 size_t relnum,
1455 const elfcpp::Rel<32, false>& rel,
1456 off_t view_size, off_t off)
1457{
1458 off_t offset = rel.get_r_offset() + off;
1459 if (offset < 0 || offset > view_size)
1460 {
1461 fprintf(stderr, _("%s: %s: TLS relocation out of range\n"),
1462 program_name,
1463 relinfo->location(relnum, rel.get_r_offset()).c_str());
1464 gold_exit(false);
1465 }
1466}
1467
1468// Check the validity of a TLS relocation. This is like assert.
1469
1470inline void
1471Target_i386::Relocate::check_tls(const Relocate_info<32, false>* relinfo,
1472 size_t relnum,
1473 const elfcpp::Rel<32, false>& rel,
1474 bool valid)
1475{
1476 if (!valid)
1477 {
1478 fprintf(stderr,
1479 _("%s: %s: TLS relocation against invalid instruction\n"),
1480 program_name,
1481 relinfo->location(relnum, rel.get_r_offset()).c_str());
1482 gold_exit(false);
61ba1cf9
ILT
1483 }
1484}
1485
1486// Relocate section data.
1487
1488void
92e059d8 1489Target_i386::relocate_section(const Relocate_info<32, false>* relinfo,
61ba1cf9
ILT
1490 unsigned int sh_type,
1491 const unsigned char* prelocs,
1492 size_t reloc_count,
61ba1cf9
ILT
1493 unsigned char* view,
1494 elfcpp::Elf_types<32>::Elf_Addr address,
1495 off_t view_size)
1496{
a3ad94ed 1497 gold_assert(sh_type == elfcpp::SHT_REL);
61ba1cf9 1498
ead1e424
ILT
1499 gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL,
1500 Target_i386::Relocate>(
92e059d8 1501 relinfo,
ead1e424 1502 this,
61ba1cf9
ILT
1503 prelocs,
1504 reloc_count,
61ba1cf9
ILT
1505 view,
1506 address,
1507 view_size);
1508}
1509
c51e6221
ILT
1510// Return a string used to fill a code section with nops to take up
1511// the specified length.
1512
1513std::string
1514Target_i386::do_code_fill(off_t length)
1515{
1516 if (length >= 16)
1517 {
1518 // Build a jmp instruction to skip over the bytes.
1519 unsigned char jmp[5];
1520 jmp[0] = 0xe9;
1521 elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
1522 return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
1523 + std::string(length - 5, '\0'));
1524 }
1525
1526 // Nop sequences of various lengths.
1527 const char nop1[1] = { 0x90 }; // nop
1528 const char nop2[2] = { 0x66, 0x90 }; // xchg %ax %ax
1529 const char nop3[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi
1530 const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi
1531 const char nop5[5] = { 0x90, 0x8d, 0x74, 0x26, // nop
1532 0x00 }; // leal 0(%esi,1),%esi
1533 const char nop6[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
1534 0x00, 0x00 };
1535 const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
1536 0x00, 0x00, 0x00 };
1537 const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop
1538 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
1539 const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi
1540 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi
1541 0x00 };
1542 const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
1543 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
1544 0x00, 0x00 };
1545 const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
1546 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
1547 0x00, 0x00, 0x00 };
1548 const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
1549 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
1550 0x00, 0x00, 0x00, 0x00 };
1551 const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
1552 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
1553 0x27, 0x00, 0x00, 0x00,
1554 0x00 };
1555 const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
1556 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
1557 0xbc, 0x27, 0x00, 0x00,
1558 0x00, 0x00 };
1559 const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
1560 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
1561 0x90, 0x90, 0x90, 0x90,
1562 0x90, 0x90, 0x90 };
1563
1564 const char* nops[16] = {
1565 NULL,
1566 nop1, nop2, nop3, nop4, nop5, nop6, nop7,
1567 nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
1568 };
1569
1570 return std::string(nops[length], length);
1571}
1572
14bfc3f5
ILT
1573// The selector for i386 object files.
1574
1575class Target_selector_i386 : public Target_selector
1576{
1577public:
1578 Target_selector_i386()
1579 : Target_selector(elfcpp::EM_386, 32, false)
1580 { }
1581
1582 Target*
ead1e424
ILT
1583 recognize(int machine, int osabi, int abiversion);
1584
1585 private:
1586 Target_i386* target_;
14bfc3f5
ILT
1587};
1588
1589// Recognize an i386 object file when we already know that the machine
1590// number is EM_386.
1591
1592Target*
ead1e424 1593Target_selector_i386::recognize(int, int, int)
14bfc3f5 1594{
ead1e424
ILT
1595 if (this->target_ == NULL)
1596 this->target_ = new Target_i386();
1597 return this->target_;
14bfc3f5
ILT
1598}
1599
1600Target_selector_i386 target_selector_i386;
1601
1602} // End anonymous namespace.
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