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14bfc3f5 ILT |
1 | // i386.cc -- i386 target support for gold. |
2 | ||
6cb15b7f ILT |
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" |
ead1e424 ILT |
24 | |
25 | #include <cstring> | |
26 | ||
14bfc3f5 | 27 | #include "elfcpp.h" |
7e1edb90 | 28 | #include "parameters.h" |
92e059d8 | 29 | #include "reloc.h" |
61ba1cf9 ILT |
30 | #include "i386.h" |
31 | #include "object.h" | |
ead1e424 | 32 | #include "symtab.h" |
92e059d8 ILT |
33 | #include "layout.h" |
34 | #include "output.h" | |
14bfc3f5 | 35 | #include "target.h" |
61ba1cf9 | 36 | #include "target-reloc.h" |
14bfc3f5 ILT |
37 | #include "target-select.h" |
38 | ||
39 | namespace | |
40 | { | |
41 | ||
42 | using namespace gold; | |
43 | ||
a3ad94ed ILT |
44 | class Output_data_plt_i386; |
45 | ||
14bfc3f5 ILT |
46 | // The i386 target class. |
47 | ||
48 | class Target_i386 : public Sized_target<32, false> | |
49 | { | |
50 | public: | |
5a6f7e2d ILT |
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), |
5a6f7e2d ILT |
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 |
92e059d8 ILT |
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, |
92e059d8 ILT |
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 | |
5a6f7e2d ILT |
73 | // Finalize the sections. |
74 | void | |
7e1edb90 | 75 | do_finalize_sections(Layout*); |
5a6f7e2d | 76 | |
92e059d8 ILT |
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 | ||
c51e6221 ILT |
87 | // Return a string used to fill a code section with nops. |
88 | std::string | |
89 | do_code_fill(off_t length); | |
90 | ||
92e059d8 ILT |
91 | private: |
92 | // The class which scans relocations. | |
93 | struct Scan | |
61ba1cf9 ILT |
94 | { |
95 | inline void | |
ead1e424 ILT |
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, |
92e059d8 ILT |
100 | const elfcpp::Rel<32, false>& reloc, unsigned int r_type, |
101 | const elfcpp::Sym<32, false>& lsym); | |
61ba1cf9 | 102 | |
92e059d8 | 103 | inline void |
ead1e424 ILT |
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, |
92e059d8 ILT |
108 | const elfcpp::Rel<32, false>& reloc, unsigned int r_type, |
109 | Symbol* gsym); | |
61ba1cf9 ILT |
110 | }; |
111 | ||
92e059d8 ILT |
112 | // The class which implements relocation. |
113 | class Relocate | |
114 | { | |
115 | public: | |
ead1e424 ILT |
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>*, |
92e059d8 ILT |
138 | unsigned char*, elfcpp::Elf_types<32>::Elf_Addr, |
139 | off_t); | |
140 | ||
141 | private: | |
142 | // Do a TLS relocation. | |
ead1e424 | 143 | inline void |
92e059d8 ILT |
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>*, |
92e059d8 ILT |
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 | ||
ead1e424 ILT |
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 | ||
92e059d8 ILT |
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); | |
ead1e424 ILT |
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_; | |
92e059d8 ILT |
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*); |
a3ad94ed ILT |
191 | |
192 | // Create a PLT entry for a global symbol. | |
193 | void | |
7e1edb90 | 194 | make_plt_entry(Symbol_table*, Layout*, Symbol*); |
a3ad94ed ILT |
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 | ||
5a6f7e2d ILT |
204 | // Get the dynamic reloc section, creating it if necessary. |
205 | Reloc_section* | |
206 | rel_dyn_section(Layout*); | |
207 | ||
a3ad94ed ILT |
208 | // Copy a relocation against a global symbol. |
209 | void | |
5a6f7e2d ILT |
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 | |
92e059d8 ILT |
214 | // Information about this specific target which we pass to the |
215 | // general Target structure. | |
75f65a3e | 216 | static const Target::Target_info i386_info; |
ead1e424 ILT |
217 | |
218 | // The GOT section. | |
dbe717ef | 219 | Output_data_got<32, false>* got_; |
a3ad94ed ILT |
220 | // The PLT section. |
221 | Output_data_plt_i386* plt_; | |
222 | // The GOT PLT section. | |
223 | Output_data_space* got_plt_; | |
5a6f7e2d ILT |
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_; | |
75f65a3e ILT |
230 | }; |
231 | ||
232 | const Target::Target_info Target_i386::i386_info = | |
233 | { | |
61ba1cf9 ILT |
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 |
dbe717ef ILT |
240 | "/usr/lib/libc.so.1", // dynamic_linker |
241 | 0x08048000, // text_segment_address | |
61ba1cf9 ILT |
242 | 0x1000, // abi_pagesize |
243 | 0x1000 // common_pagesize | |
14bfc3f5 ILT |
244 | }; |
245 | ||
ead1e424 ILT |
246 | // Get the GOT section, creating it if necessary. |
247 | ||
dbe717ef | 248 | Output_data_got<32, false>* |
7e1edb90 | 249 | Target_i386::got_section(Symbol_table* symtab, Layout* layout) |
ead1e424 ILT |
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, |
16649710 ILT |
258 | elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE, |
259 | this->got_); | |
ead1e424 | 260 | |
a3ad94ed ILT |
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, | |
16649710 ILT |
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, |
ead1e424 ILT |
278 | elfcpp::STV_HIDDEN, 0, |
279 | false, false); | |
280 | } | |
a3ad94ed | 281 | |
ead1e424 ILT |
282 | return this->got_; |
283 | } | |
284 | ||
5a6f7e2d ILT |
285 | // Get the dynamic reloc section, creating it if necessary. |
286 | ||
287 | Target_i386::Reloc_section* | |
288 | Target_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 | ||
a3ad94ed ILT |
300 | // A class to handle the PLT data. |
301 | ||
302 | class 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*); |
a3ad94ed ILT |
308 | |
309 | // Add an entry to the PLT. | |
310 | void | |
311 | add_entry(Symbol* gsym); | |
312 | ||
16649710 ILT |
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 | ||
a3ad94ed ILT |
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_; | |
a3ad94ed ILT |
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 | ||
359 | Output_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) |
a3ad94ed ILT |
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 | ||
16649710 ILT |
368 | // For some reason |
369 | ||
370 | void | |
371 | Output_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 | ||
a3ad94ed ILT |
378 | // Add an entry to the PLT. |
379 | ||
380 | void | |
381 | Output_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(); |
a3ad94ed ILT |
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 | ||
410 | unsigned 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 | ||
421 | unsigned 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 | ||
430 | unsigned 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 | ||
442 | unsigned 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 | ||
456 | void | |
457 | Output_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()) |
a3ad94ed ILT |
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()) |
a3ad94ed ILT |
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 | ||
535 | void | |
7e1edb90 | 536 | Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym) |
a3ad94ed ILT |
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_); |
16649710 ILT |
547 | layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS, |
548 | (elfcpp::SHF_ALLOC | |
549 | | elfcpp::SHF_EXECINSTR), | |
550 | this->plt_); | |
a3ad94ed ILT |
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 | ||
572 | void | |
573 | Target_i386::copy_reloc(const General_options* options, | |
5a6f7e2d ILT |
574 | Symbol_table* symtab, |
575 | Layout* layout, | |
a3ad94ed ILT |
576 | Sized_relobj<32, false>* object, |
577 | unsigned int data_shndx, Symbol* gsym, | |
5a6f7e2d | 578 | const elfcpp::Rel<32, false>& rel) |
a3ad94ed | 579 | { |
5a6f7e2d ILT |
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)) | |
a3ad94ed ILT |
586 | { |
587 | // So far we do not need a COPY reloc. Save this relocation. | |
5a6f7e2d ILT |
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 | } |
5a6f7e2d ILT |
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 | |
645 | unsigned int | |
7e1edb90 | 646 | Target_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 | ||
700 | inline void | |
7e1edb90 | 701 | Target_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 | ||
811 | inline void | |
812 | Target_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 | ||
961 | void | |
962 | Target_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 | |
998 | void | |
7e1edb90 | 999 | Target_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 | 1048 | inline bool |
92e059d8 | 1049 | Target_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 | ||
1203 | inline void | |
1204 | Target_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 | ||
1290 | inline void | |
1291 | Target_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 | ||
1387 | inline void | |
1388 | Target_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 | ||
1452 | inline void | |
1453 | Target_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 | ||
1470 | inline void | |
1471 | Target_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 | ||
1488 | void | |
92e059d8 | 1489 | Target_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 | ||
1513 | std::string | |
1514 | Target_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 | ||
1575 | class Target_selector_i386 : public Target_selector | |
1576 | { | |
1577 | public: | |
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 | ||
1592 | Target* | |
ead1e424 | 1593 | Target_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 | ||
1600 | Target_selector_i386 target_selector_i386; | |
1601 | ||
1602 | } // End anonymous namespace. |