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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 | 37 | #include "target-select.h" |
af6359d5 | 38 | #include "tls.h" |
14bfc3f5 ILT |
39 | |
40 | namespace | |
41 | { | |
42 | ||
43 | using namespace gold; | |
44 | ||
a3ad94ed ILT |
45 | class Output_data_plt_i386; |
46 | ||
14bfc3f5 | 47 | // The i386 target class. |
e041f13d ILT |
48 | // TLS info comes from |
49 | // http://people.redhat.com/drepper/tls.pdf | |
50 | // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt | |
14bfc3f5 ILT |
51 | |
52 | class Target_i386 : public Sized_target<32, false> | |
53 | { | |
54 | public: | |
5a6f7e2d ILT |
55 | typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section; |
56 | ||
14bfc3f5 | 57 | Target_i386() |
ead1e424 | 58 | : Sized_target<32, false>(&i386_info), |
5a6f7e2d ILT |
59 | got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL), |
60 | copy_relocs_(NULL), dynbss_(NULL) | |
14bfc3f5 | 61 | { } |
75f65a3e | 62 | |
92e059d8 | 63 | // Scan the relocations to look for symbol adjustments. |
61ba1cf9 | 64 | void |
92e059d8 ILT |
65 | scan_relocs(const General_options& options, |
66 | Symbol_table* symtab, | |
ead1e424 | 67 | Layout* layout, |
f6ce93d6 | 68 | Sized_relobj<32, false>* object, |
a3ad94ed | 69 | unsigned int data_shndx, |
92e059d8 ILT |
70 | unsigned int sh_type, |
71 | const unsigned char* prelocs, | |
72 | size_t reloc_count, | |
73 | size_t local_symbol_count, | |
74 | const unsigned char* plocal_symbols, | |
75 | Symbol** global_symbols); | |
61ba1cf9 | 76 | |
5a6f7e2d ILT |
77 | // Finalize the sections. |
78 | void | |
7e1edb90 | 79 | do_finalize_sections(Layout*); |
5a6f7e2d | 80 | |
ab5c9e90 ILT |
81 | // Return the value to use for a dynamic which requires special |
82 | // treatment. | |
83 | uint64_t | |
84 | do_dynsym_value(const Symbol*) const; | |
85 | ||
92e059d8 ILT |
86 | // Relocate a section. |
87 | void | |
88 | relocate_section(const Relocate_info<32, false>*, | |
89 | unsigned int sh_type, | |
90 | const unsigned char* prelocs, | |
91 | size_t reloc_count, | |
92 | unsigned char* view, | |
93 | elfcpp::Elf_types<32>::Elf_Addr view_address, | |
94 | off_t view_size); | |
95 | ||
c51e6221 ILT |
96 | // Return a string used to fill a code section with nops. |
97 | std::string | |
98 | do_code_fill(off_t length); | |
99 | ||
92e059d8 ILT |
100 | private: |
101 | // The class which scans relocations. | |
102 | struct Scan | |
61ba1cf9 ILT |
103 | { |
104 | inline void | |
ead1e424 ILT |
105 | local(const General_options& options, Symbol_table* symtab, |
106 | Layout* layout, Target_i386* target, | |
f6ce93d6 | 107 | Sized_relobj<32, false>* object, |
a3ad94ed | 108 | unsigned int data_shndx, |
92e059d8 ILT |
109 | const elfcpp::Rel<32, false>& reloc, unsigned int r_type, |
110 | const elfcpp::Sym<32, false>& lsym); | |
61ba1cf9 | 111 | |
92e059d8 | 112 | inline void |
ead1e424 ILT |
113 | global(const General_options& options, Symbol_table* symtab, |
114 | Layout* layout, Target_i386* target, | |
f6ce93d6 | 115 | Sized_relobj<32, false>* object, |
a3ad94ed | 116 | unsigned int data_shndx, |
92e059d8 ILT |
117 | const elfcpp::Rel<32, false>& reloc, unsigned int r_type, |
118 | Symbol* gsym); | |
af6359d5 ILT |
119 | |
120 | static void | |
121 | unsupported_reloc_local(Sized_relobj<32, false>*, unsigned int r_type); | |
122 | ||
123 | static void | |
124 | unsupported_reloc_global(Sized_relobj<32, false>*, unsigned int r_type, | |
125 | Symbol*); | |
61ba1cf9 ILT |
126 | }; |
127 | ||
92e059d8 ILT |
128 | // The class which implements relocation. |
129 | class Relocate | |
130 | { | |
131 | public: | |
ead1e424 | 132 | Relocate() |
46cf9fa2 ILT |
133 | : skip_call_tls_get_addr_(false), |
134 | local_dynamic_type_(LOCAL_DYNAMIC_NONE) | |
ead1e424 ILT |
135 | { } |
136 | ||
137 | ~Relocate() | |
138 | { | |
139 | if (this->skip_call_tls_get_addr_) | |
140 | { | |
141 | // FIXME: This needs to specify the location somehow. | |
142 | fprintf(stderr, _("%s: missing expected TLS relocation\n"), | |
143 | program_name); | |
144 | gold_exit(false); | |
145 | } | |
146 | } | |
147 | ||
148 | // Do a relocation. Return false if the caller should not issue | |
149 | // any warnings about this relocation. | |
150 | inline bool | |
151 | relocate(const Relocate_info<32, false>*, Target_i386*, size_t relnum, | |
92e059d8 | 152 | const elfcpp::Rel<32, false>&, |
c06b7b0b | 153 | unsigned int r_type, const Sized_symbol<32>*, |
b8e6aad9 | 154 | const Symbol_value<32>*, |
92e059d8 ILT |
155 | unsigned char*, elfcpp::Elf_types<32>::Elf_Addr, |
156 | off_t); | |
157 | ||
158 | private: | |
159 | // Do a TLS relocation. | |
ead1e424 | 160 | inline void |
92e059d8 ILT |
161 | relocate_tls(const Relocate_info<32, false>*, size_t relnum, |
162 | const elfcpp::Rel<32, false>&, | |
c06b7b0b | 163 | unsigned int r_type, const Sized_symbol<32>*, |
b8e6aad9 | 164 | const Symbol_value<32>*, |
92e059d8 ILT |
165 | unsigned char*, elfcpp::Elf_types<32>::Elf_Addr, off_t); |
166 | ||
167 | // Do a TLS Initial-Exec to Local-Exec transition. | |
168 | static inline void | |
169 | tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum, | |
170 | Output_segment* tls_segment, | |
171 | const elfcpp::Rel<32, false>&, unsigned int r_type, | |
172 | elfcpp::Elf_types<32>::Elf_Addr value, | |
173 | unsigned char* view, | |
174 | off_t view_size); | |
175 | ||
e041f13d | 176 | // Do a TLS General-Dynamic to Local-Exec transition. |
ead1e424 ILT |
177 | inline void |
178 | tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum, | |
179 | Output_segment* tls_segment, | |
180 | const elfcpp::Rel<32, false>&, unsigned int r_type, | |
181 | elfcpp::Elf_types<32>::Elf_Addr value, | |
182 | unsigned char* view, | |
183 | off_t view_size); | |
184 | ||
46cf9fa2 ILT |
185 | // Do a TLS Local-Dynamic to Local-Exec transition. |
186 | inline void | |
187 | tls_ld_to_le(const Relocate_info<32, false>*, size_t relnum, | |
188 | Output_segment* tls_segment, | |
189 | const elfcpp::Rel<32, false>&, unsigned int r_type, | |
190 | elfcpp::Elf_types<32>::Elf_Addr value, | |
191 | unsigned char* view, | |
192 | off_t view_size); | |
193 | ||
46cf9fa2 ILT |
194 | // We need to keep track of which type of local dynamic relocation |
195 | // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly. | |
196 | enum Local_dynamic_type | |
197 | { | |
198 | LOCAL_DYNAMIC_NONE, | |
199 | LOCAL_DYNAMIC_SUN, | |
200 | LOCAL_DYNAMIC_GNU | |
201 | }; | |
202 | ||
ead1e424 ILT |
203 | // This is set if we should skip the next reloc, which should be a |
204 | // PLT32 reloc against ___tls_get_addr. | |
205 | bool skip_call_tls_get_addr_; | |
46cf9fa2 ILT |
206 | // The type of local dynamic relocation we have seen in the section |
207 | // being relocated, if any. | |
208 | Local_dynamic_type local_dynamic_type_; | |
92e059d8 ILT |
209 | }; |
210 | ||
211 | // Adjust TLS relocation type based on the options and whether this | |
212 | // is a local symbol. | |
af6359d5 | 213 | static tls::Tls_optimization |
7e1edb90 | 214 | optimize_tls_reloc(bool is_final, int r_type); |
92e059d8 | 215 | |
ead1e424 | 216 | // Get the GOT section, creating it if necessary. |
dbe717ef | 217 | Output_data_got<32, false>* |
7e1edb90 | 218 | got_section(Symbol_table*, Layout*); |
a3ad94ed ILT |
219 | |
220 | // Create a PLT entry for a global symbol. | |
221 | void | |
7e1edb90 | 222 | make_plt_entry(Symbol_table*, Layout*, Symbol*); |
a3ad94ed ILT |
223 | |
224 | // Get the PLT section. | |
7bb3655e | 225 | const Output_data_plt_i386* |
a3ad94ed ILT |
226 | plt_section() const |
227 | { | |
228 | gold_assert(this->plt_ != NULL); | |
229 | return this->plt_; | |
230 | } | |
231 | ||
5a6f7e2d ILT |
232 | // Get the dynamic reloc section, creating it if necessary. |
233 | Reloc_section* | |
234 | rel_dyn_section(Layout*); | |
235 | ||
a3ad94ed ILT |
236 | // Copy a relocation against a global symbol. |
237 | void | |
5a6f7e2d ILT |
238 | copy_reloc(const General_options*, Symbol_table*, Layout*, |
239 | Sized_relobj<32, false>*, unsigned int, | |
a3ad94ed | 240 | Symbol*, const elfcpp::Rel<32, false>&); |
ead1e424 | 241 | |
92e059d8 ILT |
242 | // Information about this specific target which we pass to the |
243 | // general Target structure. | |
75f65a3e | 244 | static const Target::Target_info i386_info; |
ead1e424 ILT |
245 | |
246 | // The GOT section. | |
dbe717ef | 247 | Output_data_got<32, false>* got_; |
a3ad94ed ILT |
248 | // The PLT section. |
249 | Output_data_plt_i386* plt_; | |
250 | // The GOT PLT section. | |
251 | Output_data_space* got_plt_; | |
5a6f7e2d ILT |
252 | // The dynamic reloc section. |
253 | Reloc_section* rel_dyn_; | |
254 | // Relocs saved to avoid a COPY reloc. | |
255 | Copy_relocs<32, false>* copy_relocs_; | |
256 | // Space for variables copied with a COPY reloc. | |
257 | Output_data_space* dynbss_; | |
75f65a3e ILT |
258 | }; |
259 | ||
260 | const Target::Target_info Target_i386::i386_info = | |
261 | { | |
61ba1cf9 ILT |
262 | 32, // size |
263 | false, // is_big_endian | |
264 | elfcpp::EM_386, // machine_code | |
265 | false, // has_make_symbol | |
dbe717ef | 266 | false, // has_resolve |
c51e6221 | 267 | true, // has_code_fill |
dbe717ef ILT |
268 | "/usr/lib/libc.so.1", // dynamic_linker |
269 | 0x08048000, // text_segment_address | |
61ba1cf9 ILT |
270 | 0x1000, // abi_pagesize |
271 | 0x1000 // common_pagesize | |
14bfc3f5 ILT |
272 | }; |
273 | ||
ead1e424 ILT |
274 | // Get the GOT section, creating it if necessary. |
275 | ||
dbe717ef | 276 | Output_data_got<32, false>* |
7e1edb90 | 277 | Target_i386::got_section(Symbol_table* symtab, Layout* layout) |
ead1e424 ILT |
278 | { |
279 | if (this->got_ == NULL) | |
280 | { | |
7e1edb90 | 281 | gold_assert(symtab != NULL && layout != NULL); |
a3ad94ed | 282 | |
7e1edb90 | 283 | this->got_ = new Output_data_got<32, false>(); |
ead1e424 | 284 | |
ead1e424 | 285 | layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS, |
16649710 ILT |
286 | elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE, |
287 | this->got_); | |
ead1e424 | 288 | |
a3ad94ed ILT |
289 | // The old GNU linker creates a .got.plt section. We just |
290 | // create another set of data in the .got section. Note that we | |
291 | // always create a PLT if we create a GOT, although the PLT | |
292 | // might be empty. | |
293 | this->got_plt_ = new Output_data_space(4); | |
294 | layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS, | |
16649710 ILT |
295 | elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE, |
296 | this->got_plt_); | |
a3ad94ed | 297 | |
ead1e424 | 298 | // The first three entries are reserved. |
a3ad94ed | 299 | this->got_plt_->set_space_size(3 * 4); |
ead1e424 | 300 | |
a3ad94ed | 301 | // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT. |
14b31740 | 302 | symtab->define_in_output_data(this, "_GLOBAL_OFFSET_TABLE_", NULL, |
a3ad94ed | 303 | this->got_plt_, |
ead1e424 | 304 | 0, 0, elfcpp::STT_OBJECT, |
16649710 | 305 | elfcpp::STB_LOCAL, |
ead1e424 ILT |
306 | elfcpp::STV_HIDDEN, 0, |
307 | false, false); | |
308 | } | |
a3ad94ed | 309 | |
ead1e424 ILT |
310 | return this->got_; |
311 | } | |
312 | ||
5a6f7e2d ILT |
313 | // Get the dynamic reloc section, creating it if necessary. |
314 | ||
315 | Target_i386::Reloc_section* | |
316 | Target_i386::rel_dyn_section(Layout* layout) | |
317 | { | |
318 | if (this->rel_dyn_ == NULL) | |
319 | { | |
320 | gold_assert(layout != NULL); | |
321 | this->rel_dyn_ = new Reloc_section(); | |
322 | layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL, | |
323 | elfcpp::SHF_ALLOC, this->rel_dyn_); | |
324 | } | |
325 | return this->rel_dyn_; | |
326 | } | |
327 | ||
a3ad94ed ILT |
328 | // A class to handle the PLT data. |
329 | ||
330 | class Output_data_plt_i386 : public Output_section_data | |
331 | { | |
332 | public: | |
333 | typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section; | |
334 | ||
7e1edb90 | 335 | Output_data_plt_i386(Layout*, Output_data_space*); |
a3ad94ed ILT |
336 | |
337 | // Add an entry to the PLT. | |
338 | void | |
339 | add_entry(Symbol* gsym); | |
340 | ||
16649710 ILT |
341 | // Return the .rel.plt section data. |
342 | const Reloc_section* | |
343 | rel_plt() const | |
344 | { return this->rel_; } | |
345 | ||
346 | protected: | |
347 | void | |
348 | do_adjust_output_section(Output_section* os); | |
349 | ||
a3ad94ed ILT |
350 | private: |
351 | // The size of an entry in the PLT. | |
352 | static const int plt_entry_size = 16; | |
353 | ||
354 | // The first entry in the PLT for an executable. | |
355 | static unsigned char exec_first_plt_entry[plt_entry_size]; | |
356 | ||
357 | // The first entry in the PLT for a shared object. | |
358 | static unsigned char dyn_first_plt_entry[plt_entry_size]; | |
359 | ||
360 | // Other entries in the PLT for an executable. | |
361 | static unsigned char exec_plt_entry[plt_entry_size]; | |
362 | ||
363 | // Other entries in the PLT for a shared object. | |
364 | static unsigned char dyn_plt_entry[plt_entry_size]; | |
365 | ||
366 | // Set the final size. | |
367 | void | |
368 | do_set_address(uint64_t, off_t) | |
369 | { this->set_data_size((this->count_ + 1) * plt_entry_size); } | |
370 | ||
371 | // Write out the PLT data. | |
372 | void | |
373 | do_write(Output_file*); | |
374 | ||
375 | // The reloc section. | |
376 | Reloc_section* rel_; | |
377 | // The .got.plt section. | |
378 | Output_data_space* got_plt_; | |
379 | // The number of PLT entries. | |
380 | unsigned int count_; | |
a3ad94ed ILT |
381 | }; |
382 | ||
383 | // Create the PLT section. The ordinary .got section is an argument, | |
384 | // since we need to refer to the start. We also create our own .got | |
385 | // section just for PLT entries. | |
386 | ||
387 | Output_data_plt_i386::Output_data_plt_i386(Layout* layout, | |
7e1edb90 | 388 | Output_data_space* got_plt) |
80576242 | 389 | : Output_section_data(4), got_plt_(got_plt), count_(0) |
a3ad94ed ILT |
390 | { |
391 | this->rel_ = new Reloc_section(); | |
392 | layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL, | |
393 | elfcpp::SHF_ALLOC, this->rel_); | |
394 | } | |
395 | ||
16649710 ILT |
396 | void |
397 | Output_data_plt_i386::do_adjust_output_section(Output_section* os) | |
398 | { | |
399 | // UnixWare sets the entsize of .plt to 4, and so does the old GNU | |
400 | // linker, and so do we. | |
401 | os->set_entsize(4); | |
402 | } | |
403 | ||
a3ad94ed ILT |
404 | // Add an entry to the PLT. |
405 | ||
406 | void | |
407 | Output_data_plt_i386::add_entry(Symbol* gsym) | |
408 | { | |
409 | gold_assert(!gsym->has_plt_offset()); | |
410 | ||
411 | // Note that when setting the PLT offset we skip the initial | |
412 | // reserved PLT entry. | |
413 | gsym->set_plt_offset((this->count_ + 1) * plt_entry_size); | |
414 | ||
415 | ++this->count_; | |
416 | ||
417 | off_t got_offset = this->got_plt_->data_size(); | |
418 | ||
419 | // Every PLT entry needs a GOT entry which points back to the PLT | |
420 | // entry (this will be changed by the dynamic linker, normally | |
421 | // lazily when the function is called). | |
422 | this->got_plt_->set_space_size(got_offset + 4); | |
423 | ||
424 | // Every PLT entry needs a reloc. | |
16649710 | 425 | gsym->set_needs_dynsym_entry(); |
a3ad94ed ILT |
426 | this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_, |
427 | got_offset); | |
428 | ||
429 | // Note that we don't need to save the symbol. The contents of the | |
430 | // PLT are independent of which symbols are used. The symbols only | |
431 | // appear in the relocations. | |
432 | } | |
433 | ||
434 | // The first entry in the PLT for an executable. | |
435 | ||
436 | unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] = | |
437 | { | |
438 | 0xff, 0x35, // pushl contents of memory address | |
439 | 0, 0, 0, 0, // replaced with address of .got + 4 | |
440 | 0xff, 0x25, // jmp indirect | |
441 | 0, 0, 0, 0, // replaced with address of .got + 8 | |
442 | 0, 0, 0, 0 // unused | |
443 | }; | |
444 | ||
445 | // The first entry in the PLT for a shared object. | |
446 | ||
447 | unsigned char Output_data_plt_i386::dyn_first_plt_entry[plt_entry_size] = | |
448 | { | |
449 | 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx) | |
450 | 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx) | |
451 | 0, 0, 0, 0 // unused | |
452 | }; | |
453 | ||
454 | // Subsequent entries in the PLT for an executable. | |
455 | ||
456 | unsigned char Output_data_plt_i386::exec_plt_entry[plt_entry_size] = | |
457 | { | |
458 | 0xff, 0x25, // jmp indirect | |
459 | 0, 0, 0, 0, // replaced with address of symbol in .got | |
460 | 0x68, // pushl immediate | |
461 | 0, 0, 0, 0, // replaced with offset into relocation table | |
462 | 0xe9, // jmp relative | |
463 | 0, 0, 0, 0 // replaced with offset to start of .plt | |
464 | }; | |
465 | ||
466 | // Subsequent entries in the PLT for a shared object. | |
467 | ||
468 | unsigned char Output_data_plt_i386::dyn_plt_entry[plt_entry_size] = | |
469 | { | |
470 | 0xff, 0xa3, // jmp *offset(%ebx) | |
471 | 0, 0, 0, 0, // replaced with offset of symbol in .got | |
472 | 0x68, // pushl immediate | |
473 | 0, 0, 0, 0, // replaced with offset into relocation table | |
474 | 0xe9, // jmp relative | |
475 | 0, 0, 0, 0 // replaced with offset to start of .plt | |
476 | }; | |
477 | ||
478 | // Write out the PLT. This uses the hand-coded instructions above, | |
479 | // and adjusts them as needed. This is all specified by the i386 ELF | |
480 | // Processor Supplement. | |
481 | ||
482 | void | |
483 | Output_data_plt_i386::do_write(Output_file* of) | |
484 | { | |
485 | const off_t offset = this->offset(); | |
486 | const off_t oview_size = this->data_size(); | |
487 | unsigned char* const oview = of->get_output_view(offset, oview_size); | |
488 | ||
489 | const off_t got_file_offset = this->got_plt_->offset(); | |
490 | const off_t got_size = this->got_plt_->data_size(); | |
491 | unsigned char* const got_view = of->get_output_view(got_file_offset, | |
492 | got_size); | |
493 | ||
494 | unsigned char* pov = oview; | |
495 | ||
496 | elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address(); | |
497 | elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address(); | |
498 | ||
7e1edb90 | 499 | if (parameters->output_is_shared()) |
a3ad94ed ILT |
500 | memcpy(pov, dyn_first_plt_entry, plt_entry_size); |
501 | else | |
502 | { | |
503 | memcpy(pov, exec_first_plt_entry, plt_entry_size); | |
504 | elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4); | |
505 | elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8); | |
506 | } | |
507 | pov += plt_entry_size; | |
508 | ||
509 | unsigned char* got_pov = got_view; | |
510 | ||
511 | memset(got_pov, 0, 12); | |
512 | got_pov += 12; | |
513 | ||
514 | const int rel_size = elfcpp::Elf_sizes<32>::rel_size; | |
515 | ||
516 | unsigned int plt_offset = plt_entry_size; | |
517 | unsigned int plt_rel_offset = 0; | |
518 | unsigned int got_offset = 12; | |
519 | const unsigned int count = this->count_; | |
520 | for (unsigned int i = 0; | |
521 | i < count; | |
522 | ++i, | |
523 | pov += plt_entry_size, | |
524 | got_pov += 4, | |
525 | plt_offset += plt_entry_size, | |
526 | plt_rel_offset += rel_size, | |
527 | got_offset += 4) | |
528 | { | |
529 | // Set and adjust the PLT entry itself. | |
530 | ||
7e1edb90 | 531 | if (parameters->output_is_shared()) |
a3ad94ed ILT |
532 | { |
533 | memcpy(pov, dyn_plt_entry, plt_entry_size); | |
534 | elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset); | |
535 | } | |
536 | else | |
537 | { | |
538 | memcpy(pov, exec_plt_entry, plt_entry_size); | |
539 | elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, | |
540 | (got_address | |
541 | + got_offset)); | |
542 | } | |
543 | ||
544 | elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset); | |
545 | elfcpp::Swap<32, false>::writeval(pov + 12, | |
546 | - (plt_offset + plt_entry_size)); | |
547 | ||
548 | // Set the entry in the GOT. | |
549 | elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6); | |
550 | } | |
551 | ||
552 | gold_assert(pov - oview == oview_size); | |
553 | gold_assert(got_pov - got_view == got_size); | |
554 | ||
555 | of->write_output_view(offset, oview_size, oview); | |
556 | of->write_output_view(got_file_offset, got_size, got_view); | |
557 | } | |
558 | ||
559 | // Create a PLT entry for a global symbol. | |
560 | ||
561 | void | |
7e1edb90 | 562 | Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym) |
a3ad94ed ILT |
563 | { |
564 | if (gsym->has_plt_offset()) | |
565 | return; | |
566 | ||
567 | if (this->plt_ == NULL) | |
568 | { | |
569 | // Create the GOT sections first. | |
7e1edb90 | 570 | this->got_section(symtab, layout); |
a3ad94ed | 571 | |
7e1edb90 | 572 | this->plt_ = new Output_data_plt_i386(layout, this->got_plt_); |
16649710 ILT |
573 | layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS, |
574 | (elfcpp::SHF_ALLOC | |
575 | | elfcpp::SHF_EXECINSTR), | |
576 | this->plt_); | |
a3ad94ed ILT |
577 | } |
578 | ||
579 | this->plt_->add_entry(gsym); | |
580 | } | |
581 | ||
582 | // Handle a relocation against a non-function symbol defined in a | |
583 | // dynamic object. The traditional way to handle this is to generate | |
584 | // a COPY relocation to copy the variable at runtime from the shared | |
585 | // object into the executable's data segment. However, this is | |
586 | // undesirable in general, as if the size of the object changes in the | |
587 | // dynamic object, the executable will no longer work correctly. If | |
588 | // this relocation is in a writable section, then we can create a | |
589 | // dynamic reloc and the dynamic linker will resolve it to the correct | |
590 | // address at runtime. However, we do not want do that if the | |
591 | // relocation is in a read-only section, as it would prevent the | |
592 | // readonly segment from being shared. And if we have to eventually | |
593 | // generate a COPY reloc, then any dynamic relocations will be | |
594 | // useless. So this means that if this is a writable section, we need | |
595 | // to save the relocation until we see whether we have to create a | |
596 | // COPY relocation for this symbol for any other relocation. | |
597 | ||
598 | void | |
599 | Target_i386::copy_reloc(const General_options* options, | |
5a6f7e2d ILT |
600 | Symbol_table* symtab, |
601 | Layout* layout, | |
a3ad94ed ILT |
602 | Sized_relobj<32, false>* object, |
603 | unsigned int data_shndx, Symbol* gsym, | |
5a6f7e2d | 604 | const elfcpp::Rel<32, false>& rel) |
a3ad94ed | 605 | { |
5a6f7e2d ILT |
606 | Sized_symbol<32>* ssym; |
607 | ssym = symtab->get_sized_symbol SELECT_SIZE_NAME(32) (gsym | |
608 | SELECT_SIZE(32)); | |
609 | ||
610 | if (!Copy_relocs<32, false>::need_copy_reloc(options, object, | |
611 | data_shndx, ssym)) | |
a3ad94ed ILT |
612 | { |
613 | // So far we do not need a COPY reloc. Save this relocation. | |
5a6f7e2d ILT |
614 | // If it turns out that we never need a COPY reloc for this |
615 | // symbol, then we will emit the relocation. | |
616 | if (this->copy_relocs_ == NULL) | |
617 | this->copy_relocs_ = new Copy_relocs<32, false>(); | |
618 | this->copy_relocs_->save(ssym, object, data_shndx, rel); | |
a3ad94ed | 619 | } |
5a6f7e2d ILT |
620 | else |
621 | { | |
622 | // Allocate space for this symbol in the .bss section. | |
623 | ||
624 | elfcpp::Elf_types<32>::Elf_WXword symsize = ssym->symsize(); | |
625 | ||
626 | // There is no defined way to determine the required alignment | |
627 | // of the symbol. We pick the alignment based on the size. We | |
628 | // set an arbitrary maximum of 256. | |
629 | unsigned int align; | |
630 | for (align = 1; align < 512; align <<= 1) | |
631 | if ((symsize & align) != 0) | |
632 | break; | |
a3ad94ed | 633 | |
5a6f7e2d ILT |
634 | if (this->dynbss_ == NULL) |
635 | { | |
636 | this->dynbss_ = new Output_data_space(align); | |
637 | layout->add_output_section_data(".bss", | |
638 | elfcpp::SHT_NOBITS, | |
639 | (elfcpp::SHF_ALLOC | |
640 | | elfcpp::SHF_WRITE), | |
641 | this->dynbss_); | |
642 | } | |
643 | ||
644 | Output_data_space* dynbss = this->dynbss_; | |
645 | ||
646 | if (align > dynbss->addralign()) | |
647 | dynbss->set_space_alignment(align); | |
648 | ||
649 | off_t dynbss_size = dynbss->data_size(); | |
650 | dynbss_size = align_address(dynbss_size, align); | |
651 | off_t offset = dynbss_size; | |
652 | dynbss->set_space_size(dynbss_size + symsize); | |
653 | ||
654 | // Define the symbol in the .dynbss section. | |
14b31740 ILT |
655 | symtab->define_in_output_data(this, ssym->name(), ssym->version(), |
656 | dynbss, offset, symsize, ssym->type(), | |
657 | ssym->binding(), ssym->visibility(), | |
658 | ssym->nonvis(), false, false); | |
5a6f7e2d ILT |
659 | |
660 | // Add the COPY reloc. | |
16649710 | 661 | ssym->set_needs_dynsym_entry(); |
5a6f7e2d ILT |
662 | Reloc_section* rel_dyn = this->rel_dyn_section(layout); |
663 | rel_dyn->add_global(ssym, elfcpp::R_386_COPY, dynbss, offset); | |
664 | } | |
a3ad94ed ILT |
665 | } |
666 | ||
92e059d8 | 667 | // Optimize the TLS relocation type based on what we know about the |
a3ad94ed ILT |
668 | // symbol. IS_FINAL is true if the final address of this symbol is |
669 | // known at link time. | |
92e059d8 | 670 | |
af6359d5 | 671 | tls::Tls_optimization |
7e1edb90 | 672 | Target_i386::optimize_tls_reloc(bool is_final, int r_type) |
92e059d8 ILT |
673 | { |
674 | // If we are generating a shared library, then we can't do anything | |
675 | // in the linker. | |
7e1edb90 | 676 | if (parameters->output_is_shared()) |
af6359d5 | 677 | return tls::TLSOPT_NONE; |
92e059d8 ILT |
678 | |
679 | switch (r_type) | |
680 | { | |
681 | case elfcpp::R_386_TLS_GD: | |
682 | case elfcpp::R_386_TLS_GOTDESC: | |
683 | case elfcpp::R_386_TLS_DESC_CALL: | |
e041f13d | 684 | // These are General-Dynamic which permits fully general TLS |
92e059d8 ILT |
685 | // access. Since we know that we are generating an executable, |
686 | // we can convert this to Initial-Exec. If we also know that | |
687 | // this is a local symbol, we can further switch to Local-Exec. | |
a3ad94ed | 688 | if (is_final) |
af6359d5 ILT |
689 | return tls::TLSOPT_TO_LE; |
690 | return tls::TLSOPT_TO_IE; | |
92e059d8 ILT |
691 | |
692 | case elfcpp::R_386_TLS_LDM: | |
693 | // This is Local-Dynamic, which refers to a local symbol in the | |
694 | // dynamic TLS block. Since we know that we generating an | |
695 | // executable, we can switch to Local-Exec. | |
af6359d5 | 696 | return tls::TLSOPT_TO_LE; |
92e059d8 ILT |
697 | |
698 | case elfcpp::R_386_TLS_LDO_32: | |
af6359d5 ILT |
699 | // Another type of Local-Dynamic relocation. |
700 | return tls::TLSOPT_TO_LE; | |
92e059d8 ILT |
701 | |
702 | case elfcpp::R_386_TLS_IE: | |
703 | case elfcpp::R_386_TLS_GOTIE: | |
704 | case elfcpp::R_386_TLS_IE_32: | |
705 | // These are Initial-Exec relocs which get the thread offset | |
706 | // from the GOT. If we know that we are linking against the | |
707 | // local symbol, we can switch to Local-Exec, which links the | |
708 | // thread offset into the instruction. | |
a3ad94ed | 709 | if (is_final) |
af6359d5 ILT |
710 | return tls::TLSOPT_TO_LE; |
711 | return tls::TLSOPT_NONE; | |
8462ae85 | 712 | |
92e059d8 ILT |
713 | case elfcpp::R_386_TLS_LE: |
714 | case elfcpp::R_386_TLS_LE_32: | |
715 | // When we already have Local-Exec, there is nothing further we | |
716 | // can do. | |
af6359d5 | 717 | return tls::TLSOPT_NONE; |
92e059d8 ILT |
718 | |
719 | default: | |
a3ad94ed | 720 | gold_unreachable(); |
92e059d8 ILT |
721 | } |
722 | } | |
723 | ||
af6359d5 ILT |
724 | // Report an unsupported relocation against a local symbol. |
725 | ||
726 | void | |
727 | Target_i386::Scan::unsupported_reloc_local(Sized_relobj<32, false>* object, | |
728 | unsigned int r_type) | |
729 | { | |
730 | fprintf(stderr, _("%s: %s: unsupported reloc %u against local symbol\n"), | |
731 | program_name, object->name().c_str(), r_type); | |
732 | } | |
733 | ||
92e059d8 ILT |
734 | // Scan a relocation for a local symbol. |
735 | ||
736 | inline void | |
7e1edb90 | 737 | Target_i386::Scan::local(const General_options&, |
ead1e424 ILT |
738 | Symbol_table* symtab, |
739 | Layout* layout, | |
740 | Target_i386* target, | |
f6ce93d6 | 741 | Sized_relobj<32, false>* object, |
a3ad94ed ILT |
742 | unsigned int, |
743 | const elfcpp::Rel<32, false>&, | |
744 | unsigned int r_type, | |
92e059d8 ILT |
745 | const elfcpp::Sym<32, false>&) |
746 | { | |
747 | switch (r_type) | |
748 | { | |
749 | case elfcpp::R_386_NONE: | |
750 | case elfcpp::R_386_GNU_VTINHERIT: | |
751 | case elfcpp::R_386_GNU_VTENTRY: | |
752 | break; | |
753 | ||
754 | case elfcpp::R_386_32: | |
755 | case elfcpp::R_386_16: | |
756 | case elfcpp::R_386_8: | |
757 | // FIXME: If we are generating a shared object we need to copy | |
758 | // this relocation into the object. | |
7e1edb90 | 759 | gold_assert(!parameters->output_is_shared()); |
92e059d8 ILT |
760 | break; |
761 | ||
762 | case elfcpp::R_386_PC32: | |
763 | case elfcpp::R_386_PC16: | |
764 | case elfcpp::R_386_PC8: | |
765 | break; | |
766 | ||
ead1e424 ILT |
767 | case elfcpp::R_386_GOTOFF: |
768 | case elfcpp::R_386_GOTPC: | |
769 | // We need a GOT section. | |
7e1edb90 | 770 | target->got_section(symtab, layout); |
ead1e424 ILT |
771 | break; |
772 | ||
af6359d5 ILT |
773 | // These are relocations which should only be seen by the |
774 | // dynamic linker, and should never be seen here. | |
92e059d8 ILT |
775 | case elfcpp::R_386_COPY: |
776 | case elfcpp::R_386_GLOB_DAT: | |
777 | case elfcpp::R_386_JUMP_SLOT: | |
778 | case elfcpp::R_386_RELATIVE: | |
779 | case elfcpp::R_386_TLS_TPOFF: | |
780 | case elfcpp::R_386_TLS_DTPMOD32: | |
781 | case elfcpp::R_386_TLS_DTPOFF32: | |
782 | case elfcpp::R_386_TLS_TPOFF32: | |
783 | case elfcpp::R_386_TLS_DESC: | |
784 | fprintf(stderr, _("%s: %s: unexpected reloc %u in object file\n"), | |
785 | program_name, object->name().c_str(), r_type); | |
786 | gold_exit(false); | |
787 | break; | |
788 | ||
af6359d5 | 789 | // These are initial TLS relocs, which are expected when |
d61c17ea | 790 | // linking. |
92e059d8 ILT |
791 | case elfcpp::R_386_TLS_IE: |
792 | case elfcpp::R_386_TLS_GOTIE: | |
793 | case elfcpp::R_386_TLS_LE: | |
794 | case elfcpp::R_386_TLS_GD: | |
795 | case elfcpp::R_386_TLS_LDM: | |
796 | case elfcpp::R_386_TLS_LDO_32: | |
797 | case elfcpp::R_386_TLS_IE_32: | |
798 | case elfcpp::R_386_TLS_LE_32: | |
799 | case elfcpp::R_386_TLS_GOTDESC: | |
800 | case elfcpp::R_386_TLS_DESC_CALL: | |
7e1edb90 | 801 | { |
80576242 | 802 | bool output_is_shared = parameters->output_is_shared(); |
af6359d5 ILT |
803 | const tls::Tls_optimization optimized_type |
804 | = Target_i386::optimize_tls_reloc(!output_is_shared, r_type); | |
7e1edb90 ILT |
805 | switch (r_type) |
806 | { | |
807 | case elfcpp::R_386_TLS_LE: | |
808 | case elfcpp::R_386_TLS_LE_32: | |
809 | // FIXME: If generating a shared object, we need to copy | |
810 | // this relocation into the object. | |
80576242 | 811 | gold_assert(!output_is_shared); |
7e1edb90 | 812 | break; |
92e059d8 | 813 | |
af6359d5 ILT |
814 | case elfcpp::R_386_TLS_IE: |
815 | case elfcpp::R_386_TLS_IE_32: | |
816 | case elfcpp::R_386_TLS_GOTIE: | |
817 | // FIXME: If not relaxing to LE, we need to generate a | |
818 | // TPOFF or TPOFF32 reloc. | |
819 | if (optimized_type != tls::TLSOPT_TO_LE) | |
820 | unsupported_reloc_local(object, r_type); | |
821 | break; | |
822 | ||
46cf9fa2 | 823 | case elfcpp::R_386_TLS_LDM: |
af6359d5 ILT |
824 | // FIXME: If not relaxing to LE, we need to generate a |
825 | // DTPMOD32 reloc. | |
826 | if (optimized_type != tls::TLSOPT_TO_LE) | |
827 | unsupported_reloc_local(object, r_type); | |
828 | break; | |
829 | ||
46cf9fa2 ILT |
830 | case elfcpp::R_386_TLS_LDO_32: |
831 | break; | |
832 | ||
7e1edb90 | 833 | case elfcpp::R_386_TLS_GD: |
7e1edb90 ILT |
834 | case elfcpp::R_386_TLS_GOTDESC: |
835 | case elfcpp::R_386_TLS_DESC_CALL: | |
af6359d5 ILT |
836 | // FIXME: If not relaxing to LE, we need to generate |
837 | // DTPMOD32 and DTPOFF32 relocs. | |
838 | if (optimized_type != tls::TLSOPT_TO_LE) | |
839 | unsupported_reloc_local(object, r_type); | |
7e1edb90 | 840 | break; |
af6359d5 ILT |
841 | |
842 | default: | |
843 | gold_unreachable(); | |
7e1edb90 ILT |
844 | } |
845 | } | |
92e059d8 ILT |
846 | break; |
847 | ||
848 | case elfcpp::R_386_GOT32: | |
849 | case elfcpp::R_386_PLT32: | |
92e059d8 ILT |
850 | case elfcpp::R_386_32PLT: |
851 | case elfcpp::R_386_TLS_GD_32: | |
852 | case elfcpp::R_386_TLS_GD_PUSH: | |
853 | case elfcpp::R_386_TLS_GD_CALL: | |
854 | case elfcpp::R_386_TLS_GD_POP: | |
855 | case elfcpp::R_386_TLS_LDM_32: | |
856 | case elfcpp::R_386_TLS_LDM_PUSH: | |
857 | case elfcpp::R_386_TLS_LDM_CALL: | |
858 | case elfcpp::R_386_TLS_LDM_POP: | |
859 | case elfcpp::R_386_USED_BY_INTEL_200: | |
860 | default: | |
af6359d5 | 861 | unsupported_reloc_local(object, r_type); |
92e059d8 ILT |
862 | break; |
863 | } | |
864 | } | |
865 | ||
af6359d5 ILT |
866 | // Report an unsupported relocation against a global symbol. |
867 | ||
868 | void | |
869 | Target_i386::Scan::unsupported_reloc_global(Sized_relobj<32, false>* object, | |
870 | unsigned int r_type, | |
871 | Symbol* gsym) | |
872 | { | |
873 | fprintf(stderr, | |
874 | _("%s: %s: unsupported reloc %u against global symbol %s\n"), | |
875 | program_name, object->name().c_str(), r_type, gsym->name()); | |
876 | } | |
877 | ||
92e059d8 ILT |
878 | // Scan a relocation for a global symbol. |
879 | ||
880 | inline void | |
881 | Target_i386::Scan::global(const General_options& options, | |
ead1e424 ILT |
882 | Symbol_table* symtab, |
883 | Layout* layout, | |
884 | Target_i386* target, | |
f6ce93d6 | 885 | Sized_relobj<32, false>* object, |
a3ad94ed ILT |
886 | unsigned int data_shndx, |
887 | const elfcpp::Rel<32, false>& reloc, | |
888 | unsigned int r_type, | |
92e059d8 ILT |
889 | Symbol* gsym) |
890 | { | |
891 | switch (r_type) | |
892 | { | |
893 | case elfcpp::R_386_NONE: | |
894 | case elfcpp::R_386_GNU_VTINHERIT: | |
8462ae85 | 895 | case elfcpp::R_386_GNU_VTENTRY: |
92e059d8 ILT |
896 | break; |
897 | ||
898 | case elfcpp::R_386_32: | |
899 | case elfcpp::R_386_PC32: | |
900 | case elfcpp::R_386_16: | |
901 | case elfcpp::R_386_PC16: | |
902 | case elfcpp::R_386_8: | |
903 | case elfcpp::R_386_PC8: | |
904 | // FIXME: If we are generating a shared object we may need to | |
905 | // copy this relocation into the object. If this symbol is | |
906 | // defined in a shared object, we may need to copy this | |
907 | // relocation in order to avoid a COPY relocation. | |
7e1edb90 | 908 | gold_assert(!parameters->output_is_shared()); |
a3ad94ed | 909 | |
14b31740 | 910 | if (gsym->is_from_dynobj()) |
a3ad94ed ILT |
911 | { |
912 | // This symbol is defined in a dynamic object. If it is a | |
913 | // function, we make a PLT entry. Otherwise we need to | |
914 | // either generate a COPY reloc or copy this reloc. | |
915 | if (gsym->type() == elfcpp::STT_FUNC) | |
ab5c9e90 ILT |
916 | { |
917 | target->make_plt_entry(symtab, layout, gsym); | |
918 | ||
919 | // If this is not a PC relative reference, then we may | |
920 | // be taking the address of the function. In that case | |
921 | // we need to set the entry in the dynamic symbol table | |
922 | // to the address of the PLT entry. | |
923 | if (r_type != elfcpp::R_386_PC32 | |
924 | && r_type != elfcpp::R_386_PC16 | |
925 | && r_type != elfcpp::R_386_PC8) | |
926 | gsym->set_needs_dynsym_value(); | |
927 | } | |
a3ad94ed | 928 | else |
5a6f7e2d ILT |
929 | target->copy_reloc(&options, symtab, layout, object, data_shndx, |
930 | gsym, reloc); | |
a3ad94ed ILT |
931 | } |
932 | ||
92e059d8 ILT |
933 | break; |
934 | ||
ead1e424 | 935 | case elfcpp::R_386_GOT32: |
8462ae85 ILT |
936 | { |
937 | // The symbol requires a GOT entry. | |
7e1edb90 | 938 | Output_data_got<32, false>* got = target->got_section(symtab, layout); |
8462ae85 ILT |
939 | if (got->add_global(gsym)) |
940 | { | |
941 | // If this symbol is not fully resolved, we need to add a | |
942 | // dynamic relocation for it. | |
7e1edb90 | 943 | if (!gsym->final_value_is_known()) |
8462ae85 ILT |
944 | { |
945 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); | |
946 | rel_dyn->add_global(gsym, elfcpp::R_386_GLOB_DAT, got, | |
947 | gsym->got_offset()); | |
948 | } | |
949 | } | |
950 | } | |
ead1e424 ILT |
951 | break; |
952 | ||
953 | case elfcpp::R_386_PLT32: | |
a3ad94ed ILT |
954 | // If the symbol is fully resolved, this is just a PC32 reloc. |
955 | // Otherwise we need a PLT entry. | |
7e1edb90 | 956 | if (gsym->final_value_is_known()) |
ead1e424 | 957 | break; |
7e1edb90 | 958 | target->make_plt_entry(symtab, layout, gsym); |
ead1e424 ILT |
959 | break; |
960 | ||
961 | case elfcpp::R_386_GOTOFF: | |
962 | case elfcpp::R_386_GOTPC: | |
963 | // We need a GOT section. | |
7e1edb90 | 964 | target->got_section(symtab, layout); |
ead1e424 ILT |
965 | break; |
966 | ||
af6359d5 ILT |
967 | // These are relocations which should only be seen by the |
968 | // dynamic linker, and should never be seen here. | |
92e059d8 ILT |
969 | case elfcpp::R_386_COPY: |
970 | case elfcpp::R_386_GLOB_DAT: | |
971 | case elfcpp::R_386_JUMP_SLOT: | |
972 | case elfcpp::R_386_RELATIVE: | |
973 | case elfcpp::R_386_TLS_TPOFF: | |
974 | case elfcpp::R_386_TLS_DTPMOD32: | |
975 | case elfcpp::R_386_TLS_DTPOFF32: | |
976 | case elfcpp::R_386_TLS_TPOFF32: | |
977 | case elfcpp::R_386_TLS_DESC: | |
978 | fprintf(stderr, _("%s: %s: unexpected reloc %u in object file\n"), | |
979 | program_name, object->name().c_str(), r_type); | |
980 | gold_exit(false); | |
981 | break; | |
982 | ||
d61c17ea ILT |
983 | // These are initial tls relocs, which are expected when |
984 | // linking. | |
92e059d8 ILT |
985 | case elfcpp::R_386_TLS_IE: |
986 | case elfcpp::R_386_TLS_GOTIE: | |
987 | case elfcpp::R_386_TLS_LE: | |
988 | case elfcpp::R_386_TLS_GD: | |
989 | case elfcpp::R_386_TLS_LDM: | |
990 | case elfcpp::R_386_TLS_LDO_32: | |
991 | case elfcpp::R_386_TLS_IE_32: | |
992 | case elfcpp::R_386_TLS_LE_32: | |
993 | case elfcpp::R_386_TLS_GOTDESC: | |
994 | case elfcpp::R_386_TLS_DESC_CALL: | |
a3ad94ed | 995 | { |
7e1edb90 | 996 | const bool is_final = gsym->final_value_is_known(); |
af6359d5 ILT |
997 | const tls::Tls_optimization optimized_type |
998 | = Target_i386::optimize_tls_reloc(is_final, r_type); | |
a3ad94ed ILT |
999 | switch (r_type) |
1000 | { | |
1001 | case elfcpp::R_386_TLS_LE: | |
1002 | case elfcpp::R_386_TLS_LE_32: | |
1003 | // FIXME: If generating a shared object, we need to copy | |
1004 | // this relocation into the object. | |
7e1edb90 | 1005 | gold_assert(!parameters->output_is_shared()); |
a3ad94ed ILT |
1006 | break; |
1007 | ||
af6359d5 ILT |
1008 | case elfcpp::R_386_TLS_IE: |
1009 | case elfcpp::R_386_TLS_IE_32: | |
1010 | case elfcpp::R_386_TLS_GOTIE: | |
1011 | // FIXME: If not relaxing to LE, we need to generate a | |
1012 | // TPOFF or TPOFF32 reloc. | |
1013 | if (optimized_type != tls::TLSOPT_TO_LE) | |
1014 | unsupported_reloc_global(object, r_type, gsym); | |
1015 | break; | |
1016 | ||
46cf9fa2 | 1017 | case elfcpp::R_386_TLS_LDM: |
af6359d5 ILT |
1018 | // FIXME: If not relaxing to LE, we need to generate a |
1019 | // DTPMOD32 reloc. | |
1020 | if (optimized_type != tls::TLSOPT_TO_LE) | |
1021 | unsupported_reloc_global(object, r_type, gsym); | |
1022 | break; | |
1023 | ||
46cf9fa2 ILT |
1024 | case elfcpp::R_386_TLS_LDO_32: |
1025 | break; | |
1026 | ||
a3ad94ed | 1027 | case elfcpp::R_386_TLS_GD: |
a3ad94ed ILT |
1028 | case elfcpp::R_386_TLS_GOTDESC: |
1029 | case elfcpp::R_386_TLS_DESC_CALL: | |
af6359d5 ILT |
1030 | // FIXME: If not relaxing to LE, we need to generate |
1031 | // DTPMOD32 and DTPOFF32 relocs. | |
1032 | if (optimized_type != tls::TLSOPT_TO_LE) | |
1033 | unsupported_reloc_global(object, r_type, gsym); | |
a3ad94ed | 1034 | break; |
af6359d5 ILT |
1035 | |
1036 | default: | |
1037 | gold_unreachable(); | |
a3ad94ed ILT |
1038 | } |
1039 | } | |
92e059d8 ILT |
1040 | break; |
1041 | ||
92e059d8 ILT |
1042 | case elfcpp::R_386_32PLT: |
1043 | case elfcpp::R_386_TLS_GD_32: | |
1044 | case elfcpp::R_386_TLS_GD_PUSH: | |
1045 | case elfcpp::R_386_TLS_GD_CALL: | |
1046 | case elfcpp::R_386_TLS_GD_POP: | |
1047 | case elfcpp::R_386_TLS_LDM_32: | |
1048 | case elfcpp::R_386_TLS_LDM_PUSH: | |
1049 | case elfcpp::R_386_TLS_LDM_CALL: | |
1050 | case elfcpp::R_386_TLS_LDM_POP: | |
1051 | case elfcpp::R_386_USED_BY_INTEL_200: | |
1052 | default: | |
af6359d5 | 1053 | unsupported_reloc_global(object, r_type, gsym); |
92e059d8 ILT |
1054 | break; |
1055 | } | |
1056 | } | |
1057 | ||
1058 | // Scan relocations for a section. | |
1059 | ||
1060 | void | |
1061 | Target_i386::scan_relocs(const General_options& options, | |
1062 | Symbol_table* symtab, | |
ead1e424 | 1063 | Layout* layout, |
f6ce93d6 | 1064 | Sized_relobj<32, false>* object, |
a3ad94ed | 1065 | unsigned int data_shndx, |
92e059d8 ILT |
1066 | unsigned int sh_type, |
1067 | const unsigned char* prelocs, | |
1068 | size_t reloc_count, | |
1069 | size_t local_symbol_count, | |
1070 | const unsigned char* plocal_symbols, | |
1071 | Symbol** global_symbols) | |
1072 | { | |
1073 | if (sh_type == elfcpp::SHT_RELA) | |
1074 | { | |
1075 | fprintf(stderr, _("%s: %s: unsupported RELA reloc section\n"), | |
1076 | program_name, object->name().c_str()); | |
1077 | gold_exit(false); | |
1078 | } | |
1079 | ||
ead1e424 ILT |
1080 | gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL, |
1081 | Target_i386::Scan>( | |
92e059d8 ILT |
1082 | options, |
1083 | symtab, | |
ead1e424 ILT |
1084 | layout, |
1085 | this, | |
92e059d8 | 1086 | object, |
a3ad94ed | 1087 | data_shndx, |
92e059d8 ILT |
1088 | prelocs, |
1089 | reloc_count, | |
1090 | local_symbol_count, | |
1091 | plocal_symbols, | |
1092 | global_symbols); | |
1093 | } | |
1094 | ||
16649710 | 1095 | // Finalize the sections. |
5a6f7e2d ILT |
1096 | |
1097 | void | |
7e1edb90 | 1098 | Target_i386::do_finalize_sections(Layout* layout) |
5a6f7e2d | 1099 | { |
16649710 ILT |
1100 | // Fill in some more dynamic tags. |
1101 | Output_data_dynamic* const odyn = layout->dynamic_data(); | |
1102 | if (odyn != NULL) | |
1103 | { | |
1104 | if (this->got_plt_ != NULL) | |
1105 | odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_); | |
1106 | ||
1107 | if (this->plt_ != NULL) | |
1108 | { | |
1109 | const Output_data* od = this->plt_->rel_plt(); | |
1110 | odyn->add_section_size(elfcpp::DT_PLTRELSZ, od); | |
1111 | odyn->add_section_address(elfcpp::DT_JMPREL, od); | |
1112 | odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_REL); | |
1113 | } | |
1114 | ||
1115 | if (this->rel_dyn_ != NULL) | |
1116 | { | |
1117 | const Output_data* od = this->rel_dyn_; | |
1118 | odyn->add_section_address(elfcpp::DT_REL, od); | |
1119 | odyn->add_section_size(elfcpp::DT_RELSZ, od); | |
1120 | odyn->add_constant(elfcpp::DT_RELENT, | |
1121 | elfcpp::Elf_sizes<32>::rel_size); | |
1122 | } | |
1123 | ||
7e1edb90 | 1124 | if (!parameters->output_is_shared()) |
16649710 ILT |
1125 | { |
1126 | // The value of the DT_DEBUG tag is filled in by the dynamic | |
1127 | // linker at run time, and used by the debugger. | |
1128 | odyn->add_constant(elfcpp::DT_DEBUG, 0); | |
1129 | } | |
1130 | } | |
1131 | ||
1132 | // Emit any relocs we saved in an attempt to avoid generating COPY | |
1133 | // relocs. | |
5a6f7e2d ILT |
1134 | if (this->copy_relocs_ == NULL) |
1135 | return; | |
1136 | if (this->copy_relocs_->any_to_emit()) | |
1137 | { | |
1138 | Reloc_section* rel_dyn = this->rel_dyn_section(layout); | |
1139 | this->copy_relocs_->emit(rel_dyn); | |
1140 | } | |
1141 | delete this->copy_relocs_; | |
1142 | this->copy_relocs_ = NULL; | |
1143 | } | |
1144 | ||
61ba1cf9 ILT |
1145 | // Perform a relocation. |
1146 | ||
ead1e424 | 1147 | inline bool |
92e059d8 | 1148 | Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo, |
ead1e424 | 1149 | Target_i386* target, |
92e059d8 ILT |
1150 | size_t relnum, |
1151 | const elfcpp::Rel<32, false>& rel, | |
1152 | unsigned int r_type, | |
c06b7b0b | 1153 | const Sized_symbol<32>* gsym, |
b8e6aad9 | 1154 | const Symbol_value<32>* psymval, |
92e059d8 ILT |
1155 | unsigned char* view, |
1156 | elfcpp::Elf_types<32>::Elf_Addr address, | |
1157 | off_t view_size) | |
61ba1cf9 | 1158 | { |
ead1e424 ILT |
1159 | if (this->skip_call_tls_get_addr_) |
1160 | { | |
1161 | if (r_type != elfcpp::R_386_PLT32 | |
1162 | || gsym == NULL | |
1163 | || strcmp(gsym->name(), "___tls_get_addr") != 0) | |
1164 | { | |
1165 | fprintf(stderr, _("%s: %s: missing expected TLS relocation\n"), | |
1166 | program_name, | |
1167 | relinfo->location(relnum, rel.get_r_offset()).c_str()); | |
1168 | gold_exit(false); | |
1169 | } | |
1170 | ||
1171 | this->skip_call_tls_get_addr_ = false; | |
1172 | ||
1173 | return false; | |
1174 | } | |
1175 | ||
a3ad94ed | 1176 | // Pick the value to use for symbols defined in shared objects. |
b8e6aad9 | 1177 | Symbol_value<32> symval; |
8462ae85 | 1178 | if (gsym != NULL && gsym->is_from_dynobj() && gsym->has_plt_offset()) |
a3ad94ed | 1179 | { |
b8e6aad9 ILT |
1180 | symval.set_output_value(target->plt_section()->address() |
1181 | + gsym->plt_offset()); | |
1182 | psymval = &symval; | |
a3ad94ed ILT |
1183 | } |
1184 | ||
b8e6aad9 ILT |
1185 | const Sized_relobj<32, false>* object = relinfo->object; |
1186 | ||
61ba1cf9 ILT |
1187 | switch (r_type) |
1188 | { | |
1189 | case elfcpp::R_386_NONE: | |
92e059d8 ILT |
1190 | case elfcpp::R_386_GNU_VTINHERIT: |
1191 | case elfcpp::R_386_GNU_VTENTRY: | |
61ba1cf9 ILT |
1192 | break; |
1193 | ||
1194 | case elfcpp::R_386_32: | |
b8e6aad9 | 1195 | Relocate_functions<32, false>::rel32(view, object, psymval); |
61ba1cf9 ILT |
1196 | break; |
1197 | ||
1198 | case elfcpp::R_386_PC32: | |
b8e6aad9 | 1199 | Relocate_functions<32, false>::pcrel32(view, object, psymval, address); |
92e059d8 ILT |
1200 | break; |
1201 | ||
1202 | case elfcpp::R_386_16: | |
b8e6aad9 | 1203 | Relocate_functions<32, false>::rel16(view, object, psymval); |
92e059d8 ILT |
1204 | break; |
1205 | ||
1206 | case elfcpp::R_386_PC16: | |
b8e6aad9 | 1207 | Relocate_functions<32, false>::pcrel16(view, object, psymval, address); |
61ba1cf9 ILT |
1208 | break; |
1209 | ||
92e059d8 | 1210 | case elfcpp::R_386_8: |
b8e6aad9 | 1211 | Relocate_functions<32, false>::rel8(view, object, psymval); |
92e059d8 ILT |
1212 | break; |
1213 | ||
1214 | case elfcpp::R_386_PC8: | |
b8e6aad9 | 1215 | Relocate_functions<32, false>::pcrel8(view, object, psymval, address); |
92e059d8 ILT |
1216 | break; |
1217 | ||
ead1e424 | 1218 | case elfcpp::R_386_PLT32: |
a3ad94ed | 1219 | gold_assert(gsym->has_plt_offset() |
7e1edb90 | 1220 | || gsym->final_value_is_known()); |
b8e6aad9 | 1221 | Relocate_functions<32, false>::pcrel32(view, object, psymval, address); |
ead1e424 ILT |
1222 | break; |
1223 | ||
1224 | case elfcpp::R_386_GOT32: | |
1225 | // Local GOT offsets not yet supported. | |
a3ad94ed ILT |
1226 | gold_assert(gsym); |
1227 | gold_assert(gsym->has_got_offset()); | |
b8e6aad9 | 1228 | Relocate_functions<32, false>::rel32(view, gsym->got_offset()); |
ead1e424 ILT |
1229 | break; |
1230 | ||
1231 | case elfcpp::R_386_GOTOFF: | |
b8e6aad9 ILT |
1232 | { |
1233 | elfcpp::Elf_types<32>::Elf_Addr value; | |
1234 | value = (psymval->value(object, 0) | |
7e1edb90 | 1235 | - target->got_section(NULL, NULL)->address()); |
b8e6aad9 ILT |
1236 | Relocate_functions<32, false>::rel32(view, value); |
1237 | } | |
ead1e424 ILT |
1238 | break; |
1239 | ||
1240 | case elfcpp::R_386_GOTPC: | |
b8e6aad9 ILT |
1241 | { |
1242 | elfcpp::Elf_types<32>::Elf_Addr value; | |
7e1edb90 | 1243 | value = target->got_section(NULL, NULL)->address(); |
b8e6aad9 ILT |
1244 | Relocate_functions<32, false>::pcrel32(view, value, address); |
1245 | } | |
ead1e424 ILT |
1246 | break; |
1247 | ||
92e059d8 ILT |
1248 | case elfcpp::R_386_COPY: |
1249 | case elfcpp::R_386_GLOB_DAT: | |
1250 | case elfcpp::R_386_JUMP_SLOT: | |
1251 | case elfcpp::R_386_RELATIVE: | |
d61c17ea ILT |
1252 | // These are outstanding tls relocs, which are unexpected when |
1253 | // linking. | |
92e059d8 ILT |
1254 | case elfcpp::R_386_TLS_TPOFF: |
1255 | case elfcpp::R_386_TLS_DTPMOD32: | |
1256 | case elfcpp::R_386_TLS_DTPOFF32: | |
1257 | case elfcpp::R_386_TLS_TPOFF32: | |
1258 | case elfcpp::R_386_TLS_DESC: | |
1259 | fprintf(stderr, _("%s: %s: unexpected reloc %u in object file\n"), | |
1260 | program_name, | |
1261 | relinfo->location(relnum, rel.get_r_offset()).c_str(), | |
1262 | r_type); | |
1263 | gold_exit(false); | |
1264 | break; | |
1265 | ||
d61c17ea ILT |
1266 | // These are initial tls relocs, which are expected when |
1267 | // linking. | |
92e059d8 ILT |
1268 | case elfcpp::R_386_TLS_IE: |
1269 | case elfcpp::R_386_TLS_GOTIE: | |
1270 | case elfcpp::R_386_TLS_LE: | |
1271 | case elfcpp::R_386_TLS_GD: | |
1272 | case elfcpp::R_386_TLS_LDM: | |
1273 | case elfcpp::R_386_TLS_LDO_32: | |
1274 | case elfcpp::R_386_TLS_IE_32: | |
1275 | case elfcpp::R_386_TLS_LE_32: | |
1276 | case elfcpp::R_386_TLS_GOTDESC: | |
1277 | case elfcpp::R_386_TLS_DESC_CALL: | |
b8e6aad9 | 1278 | this->relocate_tls(relinfo, relnum, rel, r_type, gsym, psymval, view, |
ead1e424 | 1279 | address, view_size); |
92e059d8 ILT |
1280 | break; |
1281 | ||
92e059d8 ILT |
1282 | case elfcpp::R_386_32PLT: |
1283 | case elfcpp::R_386_TLS_GD_32: | |
1284 | case elfcpp::R_386_TLS_GD_PUSH: | |
1285 | case elfcpp::R_386_TLS_GD_CALL: | |
1286 | case elfcpp::R_386_TLS_GD_POP: | |
1287 | case elfcpp::R_386_TLS_LDM_32: | |
1288 | case elfcpp::R_386_TLS_LDM_PUSH: | |
1289 | case elfcpp::R_386_TLS_LDM_CALL: | |
1290 | case elfcpp::R_386_TLS_LDM_POP: | |
1291 | case elfcpp::R_386_USED_BY_INTEL_200: | |
61ba1cf9 ILT |
1292 | default: |
1293 | fprintf(stderr, _("%s: %s: unsupported reloc %u\n"), | |
92e059d8 ILT |
1294 | program_name, |
1295 | relinfo->location(relnum, rel.get_r_offset()).c_str(), | |
1296 | r_type); | |
7d00dcbd | 1297 | gold_exit(false); |
92e059d8 ILT |
1298 | break; |
1299 | } | |
ead1e424 ILT |
1300 | |
1301 | return true; | |
92e059d8 ILT |
1302 | } |
1303 | ||
1304 | // Perform a TLS relocation. | |
1305 | ||
1306 | inline void | |
1307 | Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo, | |
1308 | size_t relnum, | |
1309 | const elfcpp::Rel<32, false>& rel, | |
1310 | unsigned int r_type, | |
c06b7b0b | 1311 | const Sized_symbol<32>* gsym, |
b8e6aad9 | 1312 | const Symbol_value<32>* psymval, |
92e059d8 ILT |
1313 | unsigned char* view, |
1314 | elfcpp::Elf_types<32>::Elf_Addr, | |
1315 | off_t view_size) | |
1316 | { | |
1317 | Output_segment* tls_segment = relinfo->layout->tls_segment(); | |
1318 | if (tls_segment == NULL) | |
1319 | { | |
1320 | fprintf(stderr, _("%s: %s: TLS reloc but no TLS segment\n"), | |
1321 | program_name, | |
1322 | relinfo->location(relnum, rel.get_r_offset()).c_str()); | |
1323 | gold_exit(false); | |
1324 | } | |
1325 | ||
b8e6aad9 ILT |
1326 | elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(relinfo->object, 0); |
1327 | ||
a3ad94ed | 1328 | const bool is_final = (gsym == NULL |
7e1edb90 ILT |
1329 | ? !parameters->output_is_shared() |
1330 | : gsym->final_value_is_known()); | |
af6359d5 ILT |
1331 | const tls::Tls_optimization optimized_type |
1332 | = Target_i386::optimize_tls_reloc(is_final, r_type); | |
92e059d8 ILT |
1333 | switch (r_type) |
1334 | { | |
1335 | case elfcpp::R_386_TLS_LE_32: | |
1336 | value = tls_segment->vaddr() + tls_segment->memsz() - value; | |
1337 | Relocate_functions<32, false>::rel32(view, value); | |
1338 | break; | |
1339 | ||
1340 | case elfcpp::R_386_TLS_LE: | |
1341 | value = value - (tls_segment->vaddr() + tls_segment->memsz()); | |
1342 | Relocate_functions<32, false>::rel32(view, value); | |
1343 | break; | |
1344 | ||
1345 | case elfcpp::R_386_TLS_IE: | |
1346 | case elfcpp::R_386_TLS_GOTIE: | |
1347 | case elfcpp::R_386_TLS_IE_32: | |
af6359d5 | 1348 | if (optimized_type == tls::TLSOPT_TO_LE) |
92e059d8 ILT |
1349 | { |
1350 | Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment, | |
1351 | rel, r_type, value, view, | |
1352 | view_size); | |
1353 | break; | |
1354 | } | |
af6359d5 | 1355 | fprintf(stderr, _("%s: %s: unsupported reloc %u\n"), |
92e059d8 ILT |
1356 | program_name, |
1357 | relinfo->location(relnum, rel.get_r_offset()).c_str(), | |
1358 | r_type); | |
7d00dcbd | 1359 | gold_exit(false); |
92e059d8 ILT |
1360 | break; |
1361 | ||
1362 | case elfcpp::R_386_TLS_GD: | |
af6359d5 | 1363 | if (optimized_type == tls::TLSOPT_TO_LE) |
ead1e424 ILT |
1364 | { |
1365 | this->tls_gd_to_le(relinfo, relnum, tls_segment, | |
1366 | rel, r_type, value, view, | |
1367 | view_size); | |
1368 | break; | |
1369 | } | |
1370 | fprintf(stderr, _("%s: %s: unsupported reloc %u\n"), | |
1371 | program_name, | |
1372 | relinfo->location(relnum, rel.get_r_offset()).c_str(), | |
1373 | r_type); | |
7d00dcbd | 1374 | gold_exit(false); |
ead1e424 ILT |
1375 | break; |
1376 | ||
92e059d8 | 1377 | case elfcpp::R_386_TLS_LDM: |
46cf9fa2 ILT |
1378 | if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN) |
1379 | { | |
1380 | fprintf(stderr, | |
1381 | _("%s: %s: both SUN and GNU model TLS relocations\n"), | |
1382 | program_name, | |
1383 | relinfo->location(relnum, rel.get_r_offset()).c_str()); | |
1384 | gold_exit(false); | |
1385 | } | |
1386 | this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU; | |
af6359d5 | 1387 | if (optimized_type == tls::TLSOPT_TO_LE) |
46cf9fa2 ILT |
1388 | { |
1389 | this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, r_type, | |
1390 | value, view, view_size); | |
1391 | break; | |
1392 | } | |
1393 | fprintf(stderr, _("%s: %s: unsupported reloc %u\n"), | |
1394 | program_name, | |
1395 | relinfo->location(relnum, rel.get_r_offset()).c_str(), | |
1396 | r_type); | |
7d00dcbd | 1397 | gold_exit(false); |
46cf9fa2 ILT |
1398 | break; |
1399 | ||
92e059d8 | 1400 | case elfcpp::R_386_TLS_LDO_32: |
46cf9fa2 ILT |
1401 | // This reloc can appear in debugging sections, in which case we |
1402 | // won't see the TLS_LDM reloc. The local_dynamic_type field | |
1403 | // tells us this. | |
af6359d5 | 1404 | if (optimized_type != tls::TLSOPT_TO_LE |
46cf9fa2 ILT |
1405 | || this->local_dynamic_type_ == LOCAL_DYNAMIC_NONE) |
1406 | value = value - tls_segment->vaddr(); | |
1407 | else if (this->local_dynamic_type_ == LOCAL_DYNAMIC_GNU) | |
1408 | value = value - (tls_segment->vaddr() + tls_segment->memsz()); | |
1409 | else | |
1410 | value = tls_segment->vaddr() + tls_segment->memsz() - value; | |
1411 | Relocate_functions<32, false>::rel32(view, value); | |
1412 | break; | |
1413 | ||
92e059d8 ILT |
1414 | case elfcpp::R_386_TLS_GOTDESC: |
1415 | case elfcpp::R_386_TLS_DESC_CALL: | |
1416 | fprintf(stderr, _("%s: %s: unsupported reloc %u\n"), | |
1417 | program_name, | |
1418 | relinfo->location(relnum, rel.get_r_offset()).c_str(), | |
1419 | r_type); | |
7d00dcbd | 1420 | gold_exit(false); |
92e059d8 ILT |
1421 | break; |
1422 | } | |
1423 | } | |
1424 | ||
1425 | // Do a relocation in which we convert a TLS Initial-Exec to a | |
1426 | // Local-Exec. | |
1427 | ||
1428 | inline void | |
1429 | Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo, | |
1430 | size_t relnum, | |
1431 | Output_segment* tls_segment, | |
1432 | const elfcpp::Rel<32, false>& rel, | |
1433 | unsigned int r_type, | |
1434 | elfcpp::Elf_types<32>::Elf_Addr value, | |
1435 | unsigned char* view, | |
1436 | off_t view_size) | |
1437 | { | |
1438 | // We have to actually change the instructions, which means that we | |
1439 | // need to examine the opcodes to figure out which instruction we | |
1440 | // are looking at. | |
1441 | if (r_type == elfcpp::R_386_TLS_IE) | |
1442 | { | |
1443 | // movl %gs:XX,%eax ==> movl $YY,%eax | |
1444 | // movl %gs:XX,%reg ==> movl $YY,%reg | |
1445 | // addl %gs:XX,%reg ==> addl $YY,%reg | |
af6359d5 ILT |
1446 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -1); |
1447 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4); | |
92e059d8 ILT |
1448 | |
1449 | unsigned char op1 = view[-1]; | |
1450 | if (op1 == 0xa1) | |
1451 | { | |
1452 | // movl XX,%eax ==> movl $YY,%eax | |
1453 | view[-1] = 0xb8; | |
1454 | } | |
1455 | else | |
1456 | { | |
af6359d5 | 1457 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2); |
92e059d8 ILT |
1458 | |
1459 | unsigned char op2 = view[-2]; | |
1460 | if (op2 == 0x8b) | |
1461 | { | |
1462 | // movl XX,%reg ==> movl $YY,%reg | |
af6359d5 ILT |
1463 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
1464 | (op1 & 0xc7) == 0x05); | |
92e059d8 ILT |
1465 | view[-2] = 0xc7; |
1466 | view[-1] = 0xc0 | ((op1 >> 3) & 7); | |
1467 | } | |
1468 | else if (op2 == 0x03) | |
1469 | { | |
1470 | // addl XX,%reg ==> addl $YY,%reg | |
af6359d5 ILT |
1471 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
1472 | (op1 & 0xc7) == 0x05); | |
92e059d8 ILT |
1473 | view[-2] = 0x81; |
1474 | view[-1] = 0xc0 | ((op1 >> 3) & 7); | |
1475 | } | |
1476 | else | |
af6359d5 | 1477 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0); |
92e059d8 ILT |
1478 | } |
1479 | } | |
1480 | else | |
1481 | { | |
1482 | // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2 | |
1483 | // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2 | |
1484 | // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2 | |
af6359d5 ILT |
1485 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2); |
1486 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4); | |
92e059d8 ILT |
1487 | |
1488 | unsigned char op1 = view[-1]; | |
1489 | unsigned char op2 = view[-2]; | |
af6359d5 ILT |
1490 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
1491 | (op1 & 0xc0) == 0x80 && (op1 & 7) != 4); | |
92e059d8 ILT |
1492 | if (op2 == 0x8b) |
1493 | { | |
1494 | // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2 | |
1495 | view[-2] = 0xc7; | |
1496 | view[-1] = 0xc0 | ((op1 >> 3) & 7); | |
1497 | } | |
1498 | else if (op2 == 0x2b) | |
1499 | { | |
1500 | // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2 | |
1501 | view[-2] = 0x81; | |
1502 | view[-1] = 0xe8 | ((op1 >> 3) & 7); | |
1503 | } | |
1504 | else if (op2 == 0x03) | |
1505 | { | |
1506 | // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2 | |
1507 | view[-2] = 0x81; | |
1508 | view[-1] = 0xc0 | ((op1 >> 3) & 7); | |
1509 | } | |
1510 | else | |
af6359d5 | 1511 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0); |
92e059d8 ILT |
1512 | } |
1513 | ||
ead1e424 ILT |
1514 | value = tls_segment->vaddr() + tls_segment->memsz() - value; |
1515 | if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE) | |
1516 | value = - value; | |
92e059d8 ILT |
1517 | |
1518 | Relocate_functions<32, false>::rel32(view, value); | |
1519 | } | |
1520 | ||
e041f13d | 1521 | // Do a relocation in which we convert a TLS General-Dynamic to a |
ead1e424 ILT |
1522 | // Local-Exec. |
1523 | ||
1524 | inline void | |
1525 | Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo, | |
1526 | size_t relnum, | |
1527 | Output_segment* tls_segment, | |
1528 | const elfcpp::Rel<32, false>& rel, | |
1529 | unsigned int, | |
1530 | elfcpp::Elf_types<32>::Elf_Addr value, | |
1531 | unsigned char* view, | |
1532 | off_t view_size) | |
1533 | { | |
1534 | // leal foo(,%reg,1),%eax; call ___tls_get_addr | |
46cf9fa2 | 1535 | // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax |
ead1e424 ILT |
1536 | // leal foo(%reg),%eax; call ___tls_get_addr |
1537 | // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax | |
1538 | ||
af6359d5 ILT |
1539 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2); |
1540 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9); | |
ead1e424 ILT |
1541 | |
1542 | unsigned char op1 = view[-1]; | |
1543 | unsigned char op2 = view[-2]; | |
1544 | ||
af6359d5 ILT |
1545 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
1546 | op2 == 0x8d || op2 == 0x04); | |
1547 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8); | |
ead1e424 ILT |
1548 | |
1549 | int roff = 5; | |
1550 | ||
1551 | if (op2 == 0x04) | |
1552 | { | |
af6359d5 ILT |
1553 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3); |
1554 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d); | |
1555 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), | |
1556 | ((op1 & 0xc7) == 0x05 && op1 != (4 << 3))); | |
ead1e424 ILT |
1557 | memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12); |
1558 | } | |
1559 | else | |
1560 | { | |
af6359d5 ILT |
1561 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
1562 | (op1 & 0xf8) == 0x80 && (op1 & 7) != 4); | |
d61c17ea ILT |
1563 | if (static_cast<off_t>(rel.get_r_offset() + 9) < view_size |
1564 | && view[9] == 0x90) | |
ead1e424 ILT |
1565 | { |
1566 | // There is a trailing nop. Use the size byte subl. | |
1567 | memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12); | |
1568 | roff = 6; | |
1569 | } | |
1570 | else | |
1571 | { | |
1572 | // Use the five byte subl. | |
1573 | memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11); | |
1574 | } | |
1575 | } | |
1576 | ||
1577 | value = tls_segment->vaddr() + tls_segment->memsz() - value; | |
1578 | Relocate_functions<32, false>::rel32(view + roff, value); | |
1579 | ||
1580 | // The next reloc should be a PLT32 reloc against __tls_get_addr. | |
1581 | // We can skip it. | |
1582 | this->skip_call_tls_get_addr_ = true; | |
1583 | } | |
1584 | ||
46cf9fa2 ILT |
1585 | // Do a relocation in which we convert a TLS Local-Dynamic to a |
1586 | // Local-Exec. | |
1587 | ||
1588 | inline void | |
1589 | Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo, | |
1590 | size_t relnum, | |
1591 | Output_segment*, | |
1592 | const elfcpp::Rel<32, false>& rel, | |
1593 | unsigned int, | |
1594 | elfcpp::Elf_types<32>::Elf_Addr, | |
1595 | unsigned char* view, | |
1596 | off_t view_size) | |
1597 | { | |
1598 | // leal foo(%reg), %eax; call ___tls_get_addr | |
1599 | // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi | |
1600 | ||
af6359d5 ILT |
1601 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2); |
1602 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9); | |
46cf9fa2 ILT |
1603 | |
1604 | // FIXME: Does this test really always pass? | |
af6359d5 ILT |
1605 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
1606 | view[-2] == 0x8d && view[-1] == 0x83); | |
46cf9fa2 | 1607 | |
af6359d5 | 1608 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8); |
46cf9fa2 ILT |
1609 | |
1610 | memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11); | |
1611 | ||
1612 | // The next reloc should be a PLT32 reloc against __tls_get_addr. | |
1613 | // We can skip it. | |
1614 | this->skip_call_tls_get_addr_ = true; | |
1615 | } | |
1616 | ||
61ba1cf9 ILT |
1617 | // Relocate section data. |
1618 | ||
1619 | void | |
92e059d8 | 1620 | Target_i386::relocate_section(const Relocate_info<32, false>* relinfo, |
61ba1cf9 ILT |
1621 | unsigned int sh_type, |
1622 | const unsigned char* prelocs, | |
1623 | size_t reloc_count, | |
61ba1cf9 ILT |
1624 | unsigned char* view, |
1625 | elfcpp::Elf_types<32>::Elf_Addr address, | |
1626 | off_t view_size) | |
1627 | { | |
a3ad94ed | 1628 | gold_assert(sh_type == elfcpp::SHT_REL); |
61ba1cf9 | 1629 | |
ead1e424 ILT |
1630 | gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL, |
1631 | Target_i386::Relocate>( | |
92e059d8 | 1632 | relinfo, |
ead1e424 | 1633 | this, |
61ba1cf9 ILT |
1634 | prelocs, |
1635 | reloc_count, | |
61ba1cf9 ILT |
1636 | view, |
1637 | address, | |
1638 | view_size); | |
1639 | } | |
1640 | ||
ab5c9e90 ILT |
1641 | // Return the value to use for a dynamic which requires special |
1642 | // treatment. This is how we support equality comparisons of function | |
1643 | // pointers across shared library boundaries, as described in the | |
1644 | // processor specific ABI supplement. | |
1645 | ||
1646 | uint64_t | |
1647 | Target_i386::do_dynsym_value(const Symbol* gsym) const | |
1648 | { | |
1649 | gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset()); | |
1650 | return this->plt_section()->address() + gsym->plt_offset(); | |
1651 | } | |
1652 | ||
c51e6221 ILT |
1653 | // Return a string used to fill a code section with nops to take up |
1654 | // the specified length. | |
1655 | ||
1656 | std::string | |
1657 | Target_i386::do_code_fill(off_t length) | |
1658 | { | |
1659 | if (length >= 16) | |
1660 | { | |
1661 | // Build a jmp instruction to skip over the bytes. | |
1662 | unsigned char jmp[5]; | |
1663 | jmp[0] = 0xe9; | |
1664 | elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5); | |
1665 | return (std::string(reinterpret_cast<char*>(&jmp[0]), 5) | |
1666 | + std::string(length - 5, '\0')); | |
1667 | } | |
1668 | ||
1669 | // Nop sequences of various lengths. | |
1670 | const char nop1[1] = { 0x90 }; // nop | |
1671 | const char nop2[2] = { 0x66, 0x90 }; // xchg %ax %ax | |
1672 | const char nop3[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi | |
1673 | const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi | |
1674 | const char nop5[5] = { 0x90, 0x8d, 0x74, 0x26, // nop | |
1675 | 0x00 }; // leal 0(%esi,1),%esi | |
1676 | const char nop6[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi | |
1677 | 0x00, 0x00 }; | |
1678 | const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi | |
1679 | 0x00, 0x00, 0x00 }; | |
1680 | const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop | |
1681 | 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi | |
1682 | const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi | |
1683 | 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi | |
1684 | 0x00 }; | |
1685 | const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi | |
1686 | 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi | |
1687 | 0x00, 0x00 }; | |
1688 | const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi | |
1689 | 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi | |
1690 | 0x00, 0x00, 0x00 }; | |
1691 | const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi | |
1692 | 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi | |
1693 | 0x00, 0x00, 0x00, 0x00 }; | |
1694 | const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi | |
1695 | 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi | |
1696 | 0x27, 0x00, 0x00, 0x00, | |
1697 | 0x00 }; | |
1698 | const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi | |
1699 | 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi | |
1700 | 0xbc, 0x27, 0x00, 0x00, | |
1701 | 0x00, 0x00 }; | |
1702 | const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15 | |
1703 | 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,... | |
1704 | 0x90, 0x90, 0x90, 0x90, | |
1705 | 0x90, 0x90, 0x90 }; | |
1706 | ||
1707 | const char* nops[16] = { | |
1708 | NULL, | |
1709 | nop1, nop2, nop3, nop4, nop5, nop6, nop7, | |
1710 | nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15 | |
1711 | }; | |
1712 | ||
1713 | return std::string(nops[length], length); | |
1714 | } | |
1715 | ||
14bfc3f5 ILT |
1716 | // The selector for i386 object files. |
1717 | ||
1718 | class Target_selector_i386 : public Target_selector | |
1719 | { | |
1720 | public: | |
1721 | Target_selector_i386() | |
1722 | : Target_selector(elfcpp::EM_386, 32, false) | |
1723 | { } | |
1724 | ||
1725 | Target* | |
ead1e424 ILT |
1726 | recognize(int machine, int osabi, int abiversion); |
1727 | ||
1728 | private: | |
1729 | Target_i386* target_; | |
14bfc3f5 ILT |
1730 | }; |
1731 | ||
1732 | // Recognize an i386 object file when we already know that the machine | |
1733 | // number is EM_386. | |
1734 | ||
1735 | Target* | |
ead1e424 | 1736 | Target_selector_i386::recognize(int, int, int) |
14bfc3f5 | 1737 | { |
ead1e424 ILT |
1738 | if (this->target_ == NULL) |
1739 | this->target_ = new Target_i386(); | |
1740 | return this->target_; | |
14bfc3f5 ILT |
1741 | } |
1742 | ||
1743 | Target_selector_i386 target_selector_i386; | |
1744 | ||
1745 | } // End anonymous namespace. |