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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. | |
75f2446e | 142 | gold_error(_("missing expected TLS relocation")); |
ead1e424 ILT |
143 | } |
144 | } | |
145 | ||
146 | // Do a relocation. Return false if the caller should not issue | |
147 | // any warnings about this relocation. | |
148 | inline bool | |
149 | relocate(const Relocate_info<32, false>*, Target_i386*, size_t relnum, | |
92e059d8 | 150 | const elfcpp::Rel<32, false>&, |
c06b7b0b | 151 | unsigned int r_type, const Sized_symbol<32>*, |
b8e6aad9 | 152 | const Symbol_value<32>*, |
92e059d8 ILT |
153 | unsigned char*, elfcpp::Elf_types<32>::Elf_Addr, |
154 | off_t); | |
155 | ||
156 | private: | |
157 | // Do a TLS relocation. | |
ead1e424 | 158 | inline void |
92e059d8 ILT |
159 | relocate_tls(const Relocate_info<32, false>*, size_t relnum, |
160 | const elfcpp::Rel<32, false>&, | |
c06b7b0b | 161 | unsigned int r_type, const Sized_symbol<32>*, |
b8e6aad9 | 162 | const Symbol_value<32>*, |
92e059d8 ILT |
163 | unsigned char*, elfcpp::Elf_types<32>::Elf_Addr, off_t); |
164 | ||
165 | // Do a TLS Initial-Exec to Local-Exec transition. | |
166 | static inline void | |
167 | tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum, | |
168 | Output_segment* tls_segment, | |
169 | const elfcpp::Rel<32, false>&, unsigned int r_type, | |
170 | elfcpp::Elf_types<32>::Elf_Addr value, | |
171 | unsigned char* view, | |
172 | off_t view_size); | |
173 | ||
e041f13d | 174 | // Do a TLS General-Dynamic to Local-Exec transition. |
ead1e424 ILT |
175 | inline void |
176 | tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum, | |
177 | Output_segment* tls_segment, | |
178 | const elfcpp::Rel<32, false>&, unsigned int r_type, | |
179 | elfcpp::Elf_types<32>::Elf_Addr value, | |
180 | unsigned char* view, | |
181 | off_t view_size); | |
182 | ||
46cf9fa2 ILT |
183 | // Do a TLS Local-Dynamic to Local-Exec transition. |
184 | inline void | |
185 | tls_ld_to_le(const Relocate_info<32, false>*, size_t relnum, | |
186 | Output_segment* tls_segment, | |
187 | const elfcpp::Rel<32, false>&, unsigned int r_type, | |
188 | elfcpp::Elf_types<32>::Elf_Addr value, | |
189 | unsigned char* view, | |
190 | off_t view_size); | |
191 | ||
46cf9fa2 ILT |
192 | // We need to keep track of which type of local dynamic relocation |
193 | // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly. | |
194 | enum Local_dynamic_type | |
195 | { | |
196 | LOCAL_DYNAMIC_NONE, | |
197 | LOCAL_DYNAMIC_SUN, | |
198 | LOCAL_DYNAMIC_GNU | |
199 | }; | |
200 | ||
ead1e424 ILT |
201 | // This is set if we should skip the next reloc, which should be a |
202 | // PLT32 reloc against ___tls_get_addr. | |
203 | bool skip_call_tls_get_addr_; | |
46cf9fa2 ILT |
204 | // The type of local dynamic relocation we have seen in the section |
205 | // being relocated, if any. | |
206 | Local_dynamic_type local_dynamic_type_; | |
92e059d8 ILT |
207 | }; |
208 | ||
209 | // Adjust TLS relocation type based on the options and whether this | |
210 | // is a local symbol. | |
af6359d5 | 211 | static tls::Tls_optimization |
7e1edb90 | 212 | optimize_tls_reloc(bool is_final, int r_type); |
92e059d8 | 213 | |
ead1e424 | 214 | // Get the GOT section, creating it if necessary. |
dbe717ef | 215 | Output_data_got<32, false>* |
7e1edb90 | 216 | got_section(Symbol_table*, Layout*); |
a3ad94ed ILT |
217 | |
218 | // Create a PLT entry for a global symbol. | |
219 | void | |
7e1edb90 | 220 | make_plt_entry(Symbol_table*, Layout*, Symbol*); |
a3ad94ed ILT |
221 | |
222 | // Get the PLT section. | |
7bb3655e | 223 | const Output_data_plt_i386* |
a3ad94ed ILT |
224 | plt_section() const |
225 | { | |
226 | gold_assert(this->plt_ != NULL); | |
227 | return this->plt_; | |
228 | } | |
229 | ||
5a6f7e2d ILT |
230 | // Get the dynamic reloc section, creating it if necessary. |
231 | Reloc_section* | |
232 | rel_dyn_section(Layout*); | |
233 | ||
a3ad94ed ILT |
234 | // Copy a relocation against a global symbol. |
235 | void | |
5a6f7e2d ILT |
236 | copy_reloc(const General_options*, Symbol_table*, Layout*, |
237 | Sized_relobj<32, false>*, unsigned int, | |
a3ad94ed | 238 | Symbol*, const elfcpp::Rel<32, false>&); |
ead1e424 | 239 | |
92e059d8 ILT |
240 | // Information about this specific target which we pass to the |
241 | // general Target structure. | |
75f65a3e | 242 | static const Target::Target_info i386_info; |
ead1e424 ILT |
243 | |
244 | // The GOT section. | |
dbe717ef | 245 | Output_data_got<32, false>* got_; |
a3ad94ed ILT |
246 | // The PLT section. |
247 | Output_data_plt_i386* plt_; | |
248 | // The GOT PLT section. | |
249 | Output_data_space* got_plt_; | |
5a6f7e2d ILT |
250 | // The dynamic reloc section. |
251 | Reloc_section* rel_dyn_; | |
252 | // Relocs saved to avoid a COPY reloc. | |
253 | Copy_relocs<32, false>* copy_relocs_; | |
254 | // Space for variables copied with a COPY reloc. | |
255 | Output_data_space* dynbss_; | |
75f65a3e ILT |
256 | }; |
257 | ||
258 | const Target::Target_info Target_i386::i386_info = | |
259 | { | |
61ba1cf9 ILT |
260 | 32, // size |
261 | false, // is_big_endian | |
262 | elfcpp::EM_386, // machine_code | |
263 | false, // has_make_symbol | |
dbe717ef | 264 | false, // has_resolve |
c51e6221 | 265 | true, // has_code_fill |
dbe717ef ILT |
266 | "/usr/lib/libc.so.1", // dynamic_linker |
267 | 0x08048000, // text_segment_address | |
61ba1cf9 ILT |
268 | 0x1000, // abi_pagesize |
269 | 0x1000 // common_pagesize | |
14bfc3f5 ILT |
270 | }; |
271 | ||
ead1e424 ILT |
272 | // Get the GOT section, creating it if necessary. |
273 | ||
dbe717ef | 274 | Output_data_got<32, false>* |
7e1edb90 | 275 | Target_i386::got_section(Symbol_table* symtab, Layout* layout) |
ead1e424 ILT |
276 | { |
277 | if (this->got_ == NULL) | |
278 | { | |
7e1edb90 | 279 | gold_assert(symtab != NULL && layout != NULL); |
a3ad94ed | 280 | |
7e1edb90 | 281 | this->got_ = new Output_data_got<32, false>(); |
ead1e424 | 282 | |
ead1e424 | 283 | layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS, |
16649710 ILT |
284 | elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE, |
285 | this->got_); | |
ead1e424 | 286 | |
a3ad94ed ILT |
287 | // The old GNU linker creates a .got.plt section. We just |
288 | // create another set of data in the .got section. Note that we | |
289 | // always create a PLT if we create a GOT, although the PLT | |
290 | // might be empty. | |
291 | this->got_plt_ = new Output_data_space(4); | |
292 | layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS, | |
16649710 ILT |
293 | elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE, |
294 | this->got_plt_); | |
a3ad94ed | 295 | |
ead1e424 | 296 | // The first three entries are reserved. |
a3ad94ed | 297 | this->got_plt_->set_space_size(3 * 4); |
ead1e424 | 298 | |
a3ad94ed | 299 | // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT. |
14b31740 | 300 | symtab->define_in_output_data(this, "_GLOBAL_OFFSET_TABLE_", NULL, |
a3ad94ed | 301 | this->got_plt_, |
ead1e424 | 302 | 0, 0, elfcpp::STT_OBJECT, |
16649710 | 303 | elfcpp::STB_LOCAL, |
ead1e424 ILT |
304 | elfcpp::STV_HIDDEN, 0, |
305 | false, false); | |
306 | } | |
a3ad94ed | 307 | |
ead1e424 ILT |
308 | return this->got_; |
309 | } | |
310 | ||
5a6f7e2d ILT |
311 | // Get the dynamic reloc section, creating it if necessary. |
312 | ||
313 | Target_i386::Reloc_section* | |
314 | Target_i386::rel_dyn_section(Layout* layout) | |
315 | { | |
316 | if (this->rel_dyn_ == NULL) | |
317 | { | |
318 | gold_assert(layout != NULL); | |
319 | this->rel_dyn_ = new Reloc_section(); | |
320 | layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL, | |
321 | elfcpp::SHF_ALLOC, this->rel_dyn_); | |
322 | } | |
323 | return this->rel_dyn_; | |
324 | } | |
325 | ||
a3ad94ed ILT |
326 | // A class to handle the PLT data. |
327 | ||
328 | class Output_data_plt_i386 : public Output_section_data | |
329 | { | |
330 | public: | |
331 | typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section; | |
332 | ||
7e1edb90 | 333 | Output_data_plt_i386(Layout*, Output_data_space*); |
a3ad94ed ILT |
334 | |
335 | // Add an entry to the PLT. | |
336 | void | |
337 | add_entry(Symbol* gsym); | |
338 | ||
16649710 ILT |
339 | // Return the .rel.plt section data. |
340 | const Reloc_section* | |
341 | rel_plt() const | |
342 | { return this->rel_; } | |
343 | ||
344 | protected: | |
345 | void | |
346 | do_adjust_output_section(Output_section* os); | |
347 | ||
a3ad94ed ILT |
348 | private: |
349 | // The size of an entry in the PLT. | |
350 | static const int plt_entry_size = 16; | |
351 | ||
352 | // The first entry in the PLT for an executable. | |
353 | static unsigned char exec_first_plt_entry[plt_entry_size]; | |
354 | ||
355 | // The first entry in the PLT for a shared object. | |
356 | static unsigned char dyn_first_plt_entry[plt_entry_size]; | |
357 | ||
358 | // Other entries in the PLT for an executable. | |
359 | static unsigned char exec_plt_entry[plt_entry_size]; | |
360 | ||
361 | // Other entries in the PLT for a shared object. | |
362 | static unsigned char dyn_plt_entry[plt_entry_size]; | |
363 | ||
364 | // Set the final size. | |
365 | void | |
366 | do_set_address(uint64_t, off_t) | |
367 | { this->set_data_size((this->count_ + 1) * plt_entry_size); } | |
368 | ||
369 | // Write out the PLT data. | |
370 | void | |
371 | do_write(Output_file*); | |
372 | ||
373 | // The reloc section. | |
374 | Reloc_section* rel_; | |
375 | // The .got.plt section. | |
376 | Output_data_space* got_plt_; | |
377 | // The number of PLT entries. | |
378 | unsigned int count_; | |
a3ad94ed ILT |
379 | }; |
380 | ||
381 | // Create the PLT section. The ordinary .got section is an argument, | |
382 | // since we need to refer to the start. We also create our own .got | |
383 | // section just for PLT entries. | |
384 | ||
385 | Output_data_plt_i386::Output_data_plt_i386(Layout* layout, | |
7e1edb90 | 386 | Output_data_space* got_plt) |
80576242 | 387 | : Output_section_data(4), got_plt_(got_plt), count_(0) |
a3ad94ed ILT |
388 | { |
389 | this->rel_ = new Reloc_section(); | |
390 | layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL, | |
391 | elfcpp::SHF_ALLOC, this->rel_); | |
392 | } | |
393 | ||
16649710 ILT |
394 | void |
395 | Output_data_plt_i386::do_adjust_output_section(Output_section* os) | |
396 | { | |
397 | // UnixWare sets the entsize of .plt to 4, and so does the old GNU | |
398 | // linker, and so do we. | |
399 | os->set_entsize(4); | |
400 | } | |
401 | ||
a3ad94ed ILT |
402 | // Add an entry to the PLT. |
403 | ||
404 | void | |
405 | Output_data_plt_i386::add_entry(Symbol* gsym) | |
406 | { | |
407 | gold_assert(!gsym->has_plt_offset()); | |
408 | ||
409 | // Note that when setting the PLT offset we skip the initial | |
410 | // reserved PLT entry. | |
411 | gsym->set_plt_offset((this->count_ + 1) * plt_entry_size); | |
412 | ||
413 | ++this->count_; | |
414 | ||
415 | off_t got_offset = this->got_plt_->data_size(); | |
416 | ||
417 | // Every PLT entry needs a GOT entry which points back to the PLT | |
418 | // entry (this will be changed by the dynamic linker, normally | |
419 | // lazily when the function is called). | |
420 | this->got_plt_->set_space_size(got_offset + 4); | |
421 | ||
422 | // Every PLT entry needs a reloc. | |
16649710 | 423 | gsym->set_needs_dynsym_entry(); |
a3ad94ed ILT |
424 | this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_, |
425 | got_offset); | |
426 | ||
427 | // Note that we don't need to save the symbol. The contents of the | |
428 | // PLT are independent of which symbols are used. The symbols only | |
429 | // appear in the relocations. | |
430 | } | |
431 | ||
432 | // The first entry in the PLT for an executable. | |
433 | ||
434 | unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] = | |
435 | { | |
436 | 0xff, 0x35, // pushl contents of memory address | |
437 | 0, 0, 0, 0, // replaced with address of .got + 4 | |
438 | 0xff, 0x25, // jmp indirect | |
439 | 0, 0, 0, 0, // replaced with address of .got + 8 | |
440 | 0, 0, 0, 0 // unused | |
441 | }; | |
442 | ||
443 | // The first entry in the PLT for a shared object. | |
444 | ||
445 | unsigned char Output_data_plt_i386::dyn_first_plt_entry[plt_entry_size] = | |
446 | { | |
447 | 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx) | |
448 | 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx) | |
449 | 0, 0, 0, 0 // unused | |
450 | }; | |
451 | ||
452 | // Subsequent entries in the PLT for an executable. | |
453 | ||
454 | unsigned char Output_data_plt_i386::exec_plt_entry[plt_entry_size] = | |
455 | { | |
456 | 0xff, 0x25, // jmp indirect | |
457 | 0, 0, 0, 0, // replaced with address of symbol in .got | |
458 | 0x68, // pushl immediate | |
459 | 0, 0, 0, 0, // replaced with offset into relocation table | |
460 | 0xe9, // jmp relative | |
461 | 0, 0, 0, 0 // replaced with offset to start of .plt | |
462 | }; | |
463 | ||
464 | // Subsequent entries in the PLT for a shared object. | |
465 | ||
466 | unsigned char Output_data_plt_i386::dyn_plt_entry[plt_entry_size] = | |
467 | { | |
468 | 0xff, 0xa3, // jmp *offset(%ebx) | |
469 | 0, 0, 0, 0, // replaced with offset of symbol in .got | |
470 | 0x68, // pushl immediate | |
471 | 0, 0, 0, 0, // replaced with offset into relocation table | |
472 | 0xe9, // jmp relative | |
473 | 0, 0, 0, 0 // replaced with offset to start of .plt | |
474 | }; | |
475 | ||
476 | // Write out the PLT. This uses the hand-coded instructions above, | |
477 | // and adjusts them as needed. This is all specified by the i386 ELF | |
478 | // Processor Supplement. | |
479 | ||
480 | void | |
481 | Output_data_plt_i386::do_write(Output_file* of) | |
482 | { | |
483 | const off_t offset = this->offset(); | |
484 | const off_t oview_size = this->data_size(); | |
485 | unsigned char* const oview = of->get_output_view(offset, oview_size); | |
486 | ||
487 | const off_t got_file_offset = this->got_plt_->offset(); | |
488 | const off_t got_size = this->got_plt_->data_size(); | |
489 | unsigned char* const got_view = of->get_output_view(got_file_offset, | |
490 | got_size); | |
491 | ||
492 | unsigned char* pov = oview; | |
493 | ||
494 | elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address(); | |
495 | elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address(); | |
496 | ||
7e1edb90 | 497 | if (parameters->output_is_shared()) |
a3ad94ed ILT |
498 | memcpy(pov, dyn_first_plt_entry, plt_entry_size); |
499 | else | |
500 | { | |
501 | memcpy(pov, exec_first_plt_entry, plt_entry_size); | |
502 | elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4); | |
503 | elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8); | |
504 | } | |
505 | pov += plt_entry_size; | |
506 | ||
507 | unsigned char* got_pov = got_view; | |
508 | ||
509 | memset(got_pov, 0, 12); | |
510 | got_pov += 12; | |
511 | ||
512 | const int rel_size = elfcpp::Elf_sizes<32>::rel_size; | |
513 | ||
514 | unsigned int plt_offset = plt_entry_size; | |
515 | unsigned int plt_rel_offset = 0; | |
516 | unsigned int got_offset = 12; | |
517 | const unsigned int count = this->count_; | |
518 | for (unsigned int i = 0; | |
519 | i < count; | |
520 | ++i, | |
521 | pov += plt_entry_size, | |
522 | got_pov += 4, | |
523 | plt_offset += plt_entry_size, | |
524 | plt_rel_offset += rel_size, | |
525 | got_offset += 4) | |
526 | { | |
527 | // Set and adjust the PLT entry itself. | |
528 | ||
7e1edb90 | 529 | if (parameters->output_is_shared()) |
a3ad94ed ILT |
530 | { |
531 | memcpy(pov, dyn_plt_entry, plt_entry_size); | |
532 | elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset); | |
533 | } | |
534 | else | |
535 | { | |
536 | memcpy(pov, exec_plt_entry, plt_entry_size); | |
537 | elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, | |
538 | (got_address | |
539 | + got_offset)); | |
540 | } | |
541 | ||
542 | elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset); | |
543 | elfcpp::Swap<32, false>::writeval(pov + 12, | |
544 | - (plt_offset + plt_entry_size)); | |
545 | ||
546 | // Set the entry in the GOT. | |
547 | elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6); | |
548 | } | |
549 | ||
550 | gold_assert(pov - oview == oview_size); | |
551 | gold_assert(got_pov - got_view == got_size); | |
552 | ||
553 | of->write_output_view(offset, oview_size, oview); | |
554 | of->write_output_view(got_file_offset, got_size, got_view); | |
555 | } | |
556 | ||
557 | // Create a PLT entry for a global symbol. | |
558 | ||
559 | void | |
7e1edb90 | 560 | Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym) |
a3ad94ed ILT |
561 | { |
562 | if (gsym->has_plt_offset()) | |
563 | return; | |
564 | ||
565 | if (this->plt_ == NULL) | |
566 | { | |
567 | // Create the GOT sections first. | |
7e1edb90 | 568 | this->got_section(symtab, layout); |
a3ad94ed | 569 | |
7e1edb90 | 570 | this->plt_ = new Output_data_plt_i386(layout, this->got_plt_); |
16649710 ILT |
571 | layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS, |
572 | (elfcpp::SHF_ALLOC | |
573 | | elfcpp::SHF_EXECINSTR), | |
574 | this->plt_); | |
a3ad94ed ILT |
575 | } |
576 | ||
577 | this->plt_->add_entry(gsym); | |
578 | } | |
579 | ||
580 | // Handle a relocation against a non-function symbol defined in a | |
581 | // dynamic object. The traditional way to handle this is to generate | |
582 | // a COPY relocation to copy the variable at runtime from the shared | |
583 | // object into the executable's data segment. However, this is | |
584 | // undesirable in general, as if the size of the object changes in the | |
585 | // dynamic object, the executable will no longer work correctly. If | |
586 | // this relocation is in a writable section, then we can create a | |
587 | // dynamic reloc and the dynamic linker will resolve it to the correct | |
588 | // address at runtime. However, we do not want do that if the | |
589 | // relocation is in a read-only section, as it would prevent the | |
590 | // readonly segment from being shared. And if we have to eventually | |
591 | // generate a COPY reloc, then any dynamic relocations will be | |
592 | // useless. So this means that if this is a writable section, we need | |
593 | // to save the relocation until we see whether we have to create a | |
594 | // COPY relocation for this symbol for any other relocation. | |
595 | ||
596 | void | |
597 | Target_i386::copy_reloc(const General_options* options, | |
5a6f7e2d ILT |
598 | Symbol_table* symtab, |
599 | Layout* layout, | |
a3ad94ed ILT |
600 | Sized_relobj<32, false>* object, |
601 | unsigned int data_shndx, Symbol* gsym, | |
5a6f7e2d | 602 | const elfcpp::Rel<32, false>& rel) |
a3ad94ed | 603 | { |
5a6f7e2d ILT |
604 | Sized_symbol<32>* ssym; |
605 | ssym = symtab->get_sized_symbol SELECT_SIZE_NAME(32) (gsym | |
606 | SELECT_SIZE(32)); | |
607 | ||
608 | if (!Copy_relocs<32, false>::need_copy_reloc(options, object, | |
609 | data_shndx, ssym)) | |
a3ad94ed ILT |
610 | { |
611 | // So far we do not need a COPY reloc. Save this relocation. | |
5a6f7e2d ILT |
612 | // If it turns out that we never need a COPY reloc for this |
613 | // symbol, then we will emit the relocation. | |
614 | if (this->copy_relocs_ == NULL) | |
615 | this->copy_relocs_ = new Copy_relocs<32, false>(); | |
616 | this->copy_relocs_->save(ssym, object, data_shndx, rel); | |
a3ad94ed | 617 | } |
5a6f7e2d ILT |
618 | else |
619 | { | |
620 | // Allocate space for this symbol in the .bss section. | |
621 | ||
622 | elfcpp::Elf_types<32>::Elf_WXword symsize = ssym->symsize(); | |
623 | ||
624 | // There is no defined way to determine the required alignment | |
625 | // of the symbol. We pick the alignment based on the size. We | |
626 | // set an arbitrary maximum of 256. | |
627 | unsigned int align; | |
628 | for (align = 1; align < 512; align <<= 1) | |
629 | if ((symsize & align) != 0) | |
630 | break; | |
a3ad94ed | 631 | |
5a6f7e2d ILT |
632 | if (this->dynbss_ == NULL) |
633 | { | |
634 | this->dynbss_ = new Output_data_space(align); | |
635 | layout->add_output_section_data(".bss", | |
636 | elfcpp::SHT_NOBITS, | |
637 | (elfcpp::SHF_ALLOC | |
638 | | elfcpp::SHF_WRITE), | |
639 | this->dynbss_); | |
640 | } | |
641 | ||
642 | Output_data_space* dynbss = this->dynbss_; | |
643 | ||
644 | if (align > dynbss->addralign()) | |
645 | dynbss->set_space_alignment(align); | |
646 | ||
647 | off_t dynbss_size = dynbss->data_size(); | |
648 | dynbss_size = align_address(dynbss_size, align); | |
649 | off_t offset = dynbss_size; | |
650 | dynbss->set_space_size(dynbss_size + symsize); | |
651 | ||
652 | // Define the symbol in the .dynbss section. | |
14b31740 ILT |
653 | symtab->define_in_output_data(this, ssym->name(), ssym->version(), |
654 | dynbss, offset, symsize, ssym->type(), | |
655 | ssym->binding(), ssym->visibility(), | |
656 | ssym->nonvis(), false, false); | |
5a6f7e2d ILT |
657 | |
658 | // Add the COPY reloc. | |
16649710 | 659 | ssym->set_needs_dynsym_entry(); |
5a6f7e2d ILT |
660 | Reloc_section* rel_dyn = this->rel_dyn_section(layout); |
661 | rel_dyn->add_global(ssym, elfcpp::R_386_COPY, dynbss, offset); | |
662 | } | |
a3ad94ed ILT |
663 | } |
664 | ||
92e059d8 | 665 | // Optimize the TLS relocation type based on what we know about the |
a3ad94ed ILT |
666 | // symbol. IS_FINAL is true if the final address of this symbol is |
667 | // known at link time. | |
92e059d8 | 668 | |
af6359d5 | 669 | tls::Tls_optimization |
7e1edb90 | 670 | Target_i386::optimize_tls_reloc(bool is_final, int r_type) |
92e059d8 ILT |
671 | { |
672 | // If we are generating a shared library, then we can't do anything | |
673 | // in the linker. | |
7e1edb90 | 674 | if (parameters->output_is_shared()) |
af6359d5 | 675 | return tls::TLSOPT_NONE; |
92e059d8 ILT |
676 | |
677 | switch (r_type) | |
678 | { | |
679 | case elfcpp::R_386_TLS_GD: | |
680 | case elfcpp::R_386_TLS_GOTDESC: | |
681 | case elfcpp::R_386_TLS_DESC_CALL: | |
e041f13d | 682 | // These are General-Dynamic which permits fully general TLS |
92e059d8 ILT |
683 | // access. Since we know that we are generating an executable, |
684 | // we can convert this to Initial-Exec. If we also know that | |
685 | // this is a local symbol, we can further switch to Local-Exec. | |
a3ad94ed | 686 | if (is_final) |
af6359d5 ILT |
687 | return tls::TLSOPT_TO_LE; |
688 | return tls::TLSOPT_TO_IE; | |
92e059d8 ILT |
689 | |
690 | case elfcpp::R_386_TLS_LDM: | |
691 | // This is Local-Dynamic, which refers to a local symbol in the | |
692 | // dynamic TLS block. Since we know that we generating an | |
693 | // executable, we can switch to Local-Exec. | |
af6359d5 | 694 | return tls::TLSOPT_TO_LE; |
92e059d8 ILT |
695 | |
696 | case elfcpp::R_386_TLS_LDO_32: | |
af6359d5 ILT |
697 | // Another type of Local-Dynamic relocation. |
698 | return tls::TLSOPT_TO_LE; | |
92e059d8 ILT |
699 | |
700 | case elfcpp::R_386_TLS_IE: | |
701 | case elfcpp::R_386_TLS_GOTIE: | |
702 | case elfcpp::R_386_TLS_IE_32: | |
703 | // These are Initial-Exec relocs which get the thread offset | |
704 | // from the GOT. If we know that we are linking against the | |
705 | // local symbol, we can switch to Local-Exec, which links the | |
706 | // thread offset into the instruction. | |
a3ad94ed | 707 | if (is_final) |
af6359d5 ILT |
708 | return tls::TLSOPT_TO_LE; |
709 | return tls::TLSOPT_NONE; | |
8462ae85 | 710 | |
92e059d8 ILT |
711 | case elfcpp::R_386_TLS_LE: |
712 | case elfcpp::R_386_TLS_LE_32: | |
713 | // When we already have Local-Exec, there is nothing further we | |
714 | // can do. | |
af6359d5 | 715 | return tls::TLSOPT_NONE; |
92e059d8 ILT |
716 | |
717 | default: | |
a3ad94ed | 718 | gold_unreachable(); |
92e059d8 ILT |
719 | } |
720 | } | |
721 | ||
af6359d5 ILT |
722 | // Report an unsupported relocation against a local symbol. |
723 | ||
724 | void | |
725 | Target_i386::Scan::unsupported_reloc_local(Sized_relobj<32, false>* object, | |
726 | unsigned int r_type) | |
727 | { | |
75f2446e ILT |
728 | gold_error(_("%s: unsupported reloc %u against local symbol"), |
729 | object->name().c_str(), r_type); | |
af6359d5 ILT |
730 | } |
731 | ||
92e059d8 ILT |
732 | // Scan a relocation for a local symbol. |
733 | ||
734 | inline void | |
7e1edb90 | 735 | Target_i386::Scan::local(const General_options&, |
ead1e424 ILT |
736 | Symbol_table* symtab, |
737 | Layout* layout, | |
738 | Target_i386* target, | |
f6ce93d6 | 739 | Sized_relobj<32, false>* object, |
a3ad94ed ILT |
740 | unsigned int, |
741 | const elfcpp::Rel<32, false>&, | |
742 | unsigned int r_type, | |
92e059d8 ILT |
743 | const elfcpp::Sym<32, false>&) |
744 | { | |
745 | switch (r_type) | |
746 | { | |
747 | case elfcpp::R_386_NONE: | |
748 | case elfcpp::R_386_GNU_VTINHERIT: | |
749 | case elfcpp::R_386_GNU_VTENTRY: | |
750 | break; | |
751 | ||
752 | case elfcpp::R_386_32: | |
753 | case elfcpp::R_386_16: | |
754 | case elfcpp::R_386_8: | |
755 | // FIXME: If we are generating a shared object we need to copy | |
756 | // this relocation into the object. | |
7e1edb90 | 757 | gold_assert(!parameters->output_is_shared()); |
92e059d8 ILT |
758 | break; |
759 | ||
760 | case elfcpp::R_386_PC32: | |
761 | case elfcpp::R_386_PC16: | |
762 | case elfcpp::R_386_PC8: | |
763 | break; | |
764 | ||
ead1e424 ILT |
765 | case elfcpp::R_386_GOTOFF: |
766 | case elfcpp::R_386_GOTPC: | |
767 | // We need a GOT section. | |
7e1edb90 | 768 | target->got_section(symtab, layout); |
ead1e424 ILT |
769 | break; |
770 | ||
af6359d5 ILT |
771 | // These are relocations which should only be seen by the |
772 | // dynamic linker, and should never be seen here. | |
92e059d8 ILT |
773 | case elfcpp::R_386_COPY: |
774 | case elfcpp::R_386_GLOB_DAT: | |
775 | case elfcpp::R_386_JUMP_SLOT: | |
776 | case elfcpp::R_386_RELATIVE: | |
777 | case elfcpp::R_386_TLS_TPOFF: | |
778 | case elfcpp::R_386_TLS_DTPMOD32: | |
779 | case elfcpp::R_386_TLS_DTPOFF32: | |
780 | case elfcpp::R_386_TLS_TPOFF32: | |
781 | case elfcpp::R_386_TLS_DESC: | |
75f2446e ILT |
782 | gold_error(_("%s: unexpected reloc %u in object file\n"), |
783 | object->name().c_str(), r_type); | |
92e059d8 ILT |
784 | break; |
785 | ||
af6359d5 | 786 | // These are initial TLS relocs, which are expected when |
d61c17ea | 787 | // linking. |
92e059d8 ILT |
788 | case elfcpp::R_386_TLS_IE: |
789 | case elfcpp::R_386_TLS_GOTIE: | |
790 | case elfcpp::R_386_TLS_LE: | |
791 | case elfcpp::R_386_TLS_GD: | |
792 | case elfcpp::R_386_TLS_LDM: | |
793 | case elfcpp::R_386_TLS_LDO_32: | |
794 | case elfcpp::R_386_TLS_IE_32: | |
795 | case elfcpp::R_386_TLS_LE_32: | |
796 | case elfcpp::R_386_TLS_GOTDESC: | |
797 | case elfcpp::R_386_TLS_DESC_CALL: | |
7e1edb90 | 798 | { |
80576242 | 799 | bool output_is_shared = parameters->output_is_shared(); |
af6359d5 ILT |
800 | const tls::Tls_optimization optimized_type |
801 | = Target_i386::optimize_tls_reloc(!output_is_shared, r_type); | |
7e1edb90 ILT |
802 | switch (r_type) |
803 | { | |
804 | case elfcpp::R_386_TLS_LE: | |
805 | case elfcpp::R_386_TLS_LE_32: | |
806 | // FIXME: If generating a shared object, we need to copy | |
807 | // this relocation into the object. | |
80576242 | 808 | gold_assert(!output_is_shared); |
7e1edb90 | 809 | break; |
92e059d8 | 810 | |
af6359d5 ILT |
811 | case elfcpp::R_386_TLS_IE: |
812 | case elfcpp::R_386_TLS_IE_32: | |
813 | case elfcpp::R_386_TLS_GOTIE: | |
814 | // FIXME: If not relaxing to LE, we need to generate a | |
815 | // TPOFF or TPOFF32 reloc. | |
816 | if (optimized_type != tls::TLSOPT_TO_LE) | |
817 | unsupported_reloc_local(object, r_type); | |
818 | break; | |
819 | ||
46cf9fa2 | 820 | case elfcpp::R_386_TLS_LDM: |
af6359d5 ILT |
821 | // FIXME: If not relaxing to LE, we need to generate a |
822 | // DTPMOD32 reloc. | |
823 | if (optimized_type != tls::TLSOPT_TO_LE) | |
824 | unsupported_reloc_local(object, r_type); | |
825 | break; | |
826 | ||
46cf9fa2 ILT |
827 | case elfcpp::R_386_TLS_LDO_32: |
828 | break; | |
829 | ||
7e1edb90 | 830 | case elfcpp::R_386_TLS_GD: |
7e1edb90 ILT |
831 | case elfcpp::R_386_TLS_GOTDESC: |
832 | case elfcpp::R_386_TLS_DESC_CALL: | |
af6359d5 ILT |
833 | // FIXME: If not relaxing to LE, we need to generate |
834 | // DTPMOD32 and DTPOFF32 relocs. | |
835 | if (optimized_type != tls::TLSOPT_TO_LE) | |
836 | unsupported_reloc_local(object, r_type); | |
7e1edb90 | 837 | break; |
af6359d5 ILT |
838 | |
839 | default: | |
840 | gold_unreachable(); | |
7e1edb90 ILT |
841 | } |
842 | } | |
92e059d8 ILT |
843 | break; |
844 | ||
845 | case elfcpp::R_386_GOT32: | |
846 | case elfcpp::R_386_PLT32: | |
92e059d8 ILT |
847 | case elfcpp::R_386_32PLT: |
848 | case elfcpp::R_386_TLS_GD_32: | |
849 | case elfcpp::R_386_TLS_GD_PUSH: | |
850 | case elfcpp::R_386_TLS_GD_CALL: | |
851 | case elfcpp::R_386_TLS_GD_POP: | |
852 | case elfcpp::R_386_TLS_LDM_32: | |
853 | case elfcpp::R_386_TLS_LDM_PUSH: | |
854 | case elfcpp::R_386_TLS_LDM_CALL: | |
855 | case elfcpp::R_386_TLS_LDM_POP: | |
856 | case elfcpp::R_386_USED_BY_INTEL_200: | |
857 | default: | |
af6359d5 | 858 | unsupported_reloc_local(object, r_type); |
92e059d8 ILT |
859 | break; |
860 | } | |
861 | } | |
862 | ||
af6359d5 ILT |
863 | // Report an unsupported relocation against a global symbol. |
864 | ||
865 | void | |
866 | Target_i386::Scan::unsupported_reloc_global(Sized_relobj<32, false>* object, | |
867 | unsigned int r_type, | |
868 | Symbol* gsym) | |
869 | { | |
75f2446e ILT |
870 | gold_error(_("%s: unsupported reloc %u against global symbol %s"), |
871 | object->name().c_str(), r_type, gsym->name()); | |
af6359d5 ILT |
872 | } |
873 | ||
92e059d8 ILT |
874 | // Scan a relocation for a global symbol. |
875 | ||
876 | inline void | |
877 | Target_i386::Scan::global(const General_options& options, | |
ead1e424 ILT |
878 | Symbol_table* symtab, |
879 | Layout* layout, | |
880 | Target_i386* target, | |
f6ce93d6 | 881 | Sized_relobj<32, false>* object, |
a3ad94ed ILT |
882 | unsigned int data_shndx, |
883 | const elfcpp::Rel<32, false>& reloc, | |
884 | unsigned int r_type, | |
92e059d8 ILT |
885 | Symbol* gsym) |
886 | { | |
887 | switch (r_type) | |
888 | { | |
889 | case elfcpp::R_386_NONE: | |
890 | case elfcpp::R_386_GNU_VTINHERIT: | |
8462ae85 | 891 | case elfcpp::R_386_GNU_VTENTRY: |
92e059d8 ILT |
892 | break; |
893 | ||
894 | case elfcpp::R_386_32: | |
895 | case elfcpp::R_386_PC32: | |
896 | case elfcpp::R_386_16: | |
897 | case elfcpp::R_386_PC16: | |
898 | case elfcpp::R_386_8: | |
899 | case elfcpp::R_386_PC8: | |
900 | // FIXME: If we are generating a shared object we may need to | |
901 | // copy this relocation into the object. If this symbol is | |
902 | // defined in a shared object, we may need to copy this | |
903 | // relocation in order to avoid a COPY relocation. | |
7e1edb90 | 904 | gold_assert(!parameters->output_is_shared()); |
a3ad94ed | 905 | |
14b31740 | 906 | if (gsym->is_from_dynobj()) |
a3ad94ed ILT |
907 | { |
908 | // This symbol is defined in a dynamic object. If it is a | |
909 | // function, we make a PLT entry. Otherwise we need to | |
910 | // either generate a COPY reloc or copy this reloc. | |
911 | if (gsym->type() == elfcpp::STT_FUNC) | |
ab5c9e90 ILT |
912 | { |
913 | target->make_plt_entry(symtab, layout, gsym); | |
914 | ||
915 | // If this is not a PC relative reference, then we may | |
916 | // be taking the address of the function. In that case | |
917 | // we need to set the entry in the dynamic symbol table | |
918 | // to the address of the PLT entry. | |
919 | if (r_type != elfcpp::R_386_PC32 | |
920 | && r_type != elfcpp::R_386_PC16 | |
921 | && r_type != elfcpp::R_386_PC8) | |
922 | gsym->set_needs_dynsym_value(); | |
923 | } | |
a3ad94ed | 924 | else |
5a6f7e2d ILT |
925 | target->copy_reloc(&options, symtab, layout, object, data_shndx, |
926 | gsym, reloc); | |
a3ad94ed ILT |
927 | } |
928 | ||
92e059d8 ILT |
929 | break; |
930 | ||
ead1e424 | 931 | case elfcpp::R_386_GOT32: |
8462ae85 ILT |
932 | { |
933 | // The symbol requires a GOT entry. | |
7e1edb90 | 934 | Output_data_got<32, false>* got = target->got_section(symtab, layout); |
8462ae85 ILT |
935 | if (got->add_global(gsym)) |
936 | { | |
937 | // If this symbol is not fully resolved, we need to add a | |
938 | // dynamic relocation for it. | |
7e1edb90 | 939 | if (!gsym->final_value_is_known()) |
8462ae85 ILT |
940 | { |
941 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); | |
942 | rel_dyn->add_global(gsym, elfcpp::R_386_GLOB_DAT, got, | |
943 | gsym->got_offset()); | |
944 | } | |
945 | } | |
946 | } | |
ead1e424 ILT |
947 | break; |
948 | ||
949 | case elfcpp::R_386_PLT32: | |
a3ad94ed ILT |
950 | // If the symbol is fully resolved, this is just a PC32 reloc. |
951 | // Otherwise we need a PLT entry. | |
7e1edb90 | 952 | if (gsym->final_value_is_known()) |
ead1e424 | 953 | break; |
7e1edb90 | 954 | target->make_plt_entry(symtab, layout, gsym); |
ead1e424 ILT |
955 | break; |
956 | ||
957 | case elfcpp::R_386_GOTOFF: | |
958 | case elfcpp::R_386_GOTPC: | |
959 | // We need a GOT section. | |
7e1edb90 | 960 | target->got_section(symtab, layout); |
ead1e424 ILT |
961 | break; |
962 | ||
af6359d5 ILT |
963 | // These are relocations which should only be seen by the |
964 | // dynamic linker, and should never be seen here. | |
92e059d8 ILT |
965 | case elfcpp::R_386_COPY: |
966 | case elfcpp::R_386_GLOB_DAT: | |
967 | case elfcpp::R_386_JUMP_SLOT: | |
968 | case elfcpp::R_386_RELATIVE: | |
969 | case elfcpp::R_386_TLS_TPOFF: | |
970 | case elfcpp::R_386_TLS_DTPMOD32: | |
971 | case elfcpp::R_386_TLS_DTPOFF32: | |
972 | case elfcpp::R_386_TLS_TPOFF32: | |
973 | case elfcpp::R_386_TLS_DESC: | |
75f2446e ILT |
974 | gold_error(_("%s: unexpected reloc %u in object file"), |
975 | object->name().c_str(), r_type); | |
92e059d8 ILT |
976 | break; |
977 | ||
d61c17ea ILT |
978 | // These are initial tls relocs, which are expected when |
979 | // linking. | |
92e059d8 ILT |
980 | case elfcpp::R_386_TLS_IE: |
981 | case elfcpp::R_386_TLS_GOTIE: | |
982 | case elfcpp::R_386_TLS_LE: | |
983 | case elfcpp::R_386_TLS_GD: | |
984 | case elfcpp::R_386_TLS_LDM: | |
985 | case elfcpp::R_386_TLS_LDO_32: | |
986 | case elfcpp::R_386_TLS_IE_32: | |
987 | case elfcpp::R_386_TLS_LE_32: | |
988 | case elfcpp::R_386_TLS_GOTDESC: | |
989 | case elfcpp::R_386_TLS_DESC_CALL: | |
a3ad94ed | 990 | { |
7e1edb90 | 991 | const bool is_final = gsym->final_value_is_known(); |
af6359d5 ILT |
992 | const tls::Tls_optimization optimized_type |
993 | = Target_i386::optimize_tls_reloc(is_final, r_type); | |
a3ad94ed ILT |
994 | switch (r_type) |
995 | { | |
996 | case elfcpp::R_386_TLS_LE: | |
997 | case elfcpp::R_386_TLS_LE_32: | |
998 | // FIXME: If generating a shared object, we need to copy | |
999 | // this relocation into the object. | |
7e1edb90 | 1000 | gold_assert(!parameters->output_is_shared()); |
a3ad94ed ILT |
1001 | break; |
1002 | ||
af6359d5 ILT |
1003 | case elfcpp::R_386_TLS_IE: |
1004 | case elfcpp::R_386_TLS_IE_32: | |
1005 | case elfcpp::R_386_TLS_GOTIE: | |
1006 | // FIXME: If not relaxing to LE, we need to generate a | |
1007 | // TPOFF or TPOFF32 reloc. | |
1008 | if (optimized_type != tls::TLSOPT_TO_LE) | |
1009 | unsupported_reloc_global(object, r_type, gsym); | |
1010 | break; | |
1011 | ||
46cf9fa2 | 1012 | case elfcpp::R_386_TLS_LDM: |
af6359d5 ILT |
1013 | // FIXME: If not relaxing to LE, we need to generate a |
1014 | // DTPMOD32 reloc. | |
1015 | if (optimized_type != tls::TLSOPT_TO_LE) | |
1016 | unsupported_reloc_global(object, r_type, gsym); | |
1017 | break; | |
1018 | ||
46cf9fa2 ILT |
1019 | case elfcpp::R_386_TLS_LDO_32: |
1020 | break; | |
1021 | ||
a3ad94ed | 1022 | case elfcpp::R_386_TLS_GD: |
a3ad94ed ILT |
1023 | case elfcpp::R_386_TLS_GOTDESC: |
1024 | case elfcpp::R_386_TLS_DESC_CALL: | |
af6359d5 ILT |
1025 | // FIXME: If not relaxing to LE, we need to generate |
1026 | // DTPMOD32 and DTPOFF32 relocs. | |
1027 | if (optimized_type != tls::TLSOPT_TO_LE) | |
1028 | unsupported_reloc_global(object, r_type, gsym); | |
a3ad94ed | 1029 | break; |
af6359d5 ILT |
1030 | |
1031 | default: | |
1032 | gold_unreachable(); | |
a3ad94ed ILT |
1033 | } |
1034 | } | |
92e059d8 ILT |
1035 | break; |
1036 | ||
92e059d8 ILT |
1037 | case elfcpp::R_386_32PLT: |
1038 | case elfcpp::R_386_TLS_GD_32: | |
1039 | case elfcpp::R_386_TLS_GD_PUSH: | |
1040 | case elfcpp::R_386_TLS_GD_CALL: | |
1041 | case elfcpp::R_386_TLS_GD_POP: | |
1042 | case elfcpp::R_386_TLS_LDM_32: | |
1043 | case elfcpp::R_386_TLS_LDM_PUSH: | |
1044 | case elfcpp::R_386_TLS_LDM_CALL: | |
1045 | case elfcpp::R_386_TLS_LDM_POP: | |
1046 | case elfcpp::R_386_USED_BY_INTEL_200: | |
1047 | default: | |
af6359d5 | 1048 | unsupported_reloc_global(object, r_type, gsym); |
92e059d8 ILT |
1049 | break; |
1050 | } | |
1051 | } | |
1052 | ||
1053 | // Scan relocations for a section. | |
1054 | ||
1055 | void | |
1056 | Target_i386::scan_relocs(const General_options& options, | |
1057 | Symbol_table* symtab, | |
ead1e424 | 1058 | Layout* layout, |
f6ce93d6 | 1059 | Sized_relobj<32, false>* object, |
a3ad94ed | 1060 | unsigned int data_shndx, |
92e059d8 ILT |
1061 | unsigned int sh_type, |
1062 | const unsigned char* prelocs, | |
1063 | size_t reloc_count, | |
1064 | size_t local_symbol_count, | |
1065 | const unsigned char* plocal_symbols, | |
1066 | Symbol** global_symbols) | |
1067 | { | |
1068 | if (sh_type == elfcpp::SHT_RELA) | |
1069 | { | |
75f2446e ILT |
1070 | gold_error(_("%s: unsupported RELA reloc section"), |
1071 | object->name().c_str()); | |
1072 | return; | |
92e059d8 ILT |
1073 | } |
1074 | ||
ead1e424 ILT |
1075 | gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL, |
1076 | Target_i386::Scan>( | |
92e059d8 ILT |
1077 | options, |
1078 | symtab, | |
ead1e424 ILT |
1079 | layout, |
1080 | this, | |
92e059d8 | 1081 | object, |
a3ad94ed | 1082 | data_shndx, |
92e059d8 ILT |
1083 | prelocs, |
1084 | reloc_count, | |
1085 | local_symbol_count, | |
1086 | plocal_symbols, | |
1087 | global_symbols); | |
1088 | } | |
1089 | ||
16649710 | 1090 | // Finalize the sections. |
5a6f7e2d ILT |
1091 | |
1092 | void | |
7e1edb90 | 1093 | Target_i386::do_finalize_sections(Layout* layout) |
5a6f7e2d | 1094 | { |
16649710 ILT |
1095 | // Fill in some more dynamic tags. |
1096 | Output_data_dynamic* const odyn = layout->dynamic_data(); | |
1097 | if (odyn != NULL) | |
1098 | { | |
1099 | if (this->got_plt_ != NULL) | |
1100 | odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_); | |
1101 | ||
1102 | if (this->plt_ != NULL) | |
1103 | { | |
1104 | const Output_data* od = this->plt_->rel_plt(); | |
1105 | odyn->add_section_size(elfcpp::DT_PLTRELSZ, od); | |
1106 | odyn->add_section_address(elfcpp::DT_JMPREL, od); | |
1107 | odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_REL); | |
1108 | } | |
1109 | ||
1110 | if (this->rel_dyn_ != NULL) | |
1111 | { | |
1112 | const Output_data* od = this->rel_dyn_; | |
1113 | odyn->add_section_address(elfcpp::DT_REL, od); | |
1114 | odyn->add_section_size(elfcpp::DT_RELSZ, od); | |
1115 | odyn->add_constant(elfcpp::DT_RELENT, | |
1116 | elfcpp::Elf_sizes<32>::rel_size); | |
1117 | } | |
1118 | ||
7e1edb90 | 1119 | if (!parameters->output_is_shared()) |
16649710 ILT |
1120 | { |
1121 | // The value of the DT_DEBUG tag is filled in by the dynamic | |
1122 | // linker at run time, and used by the debugger. | |
1123 | odyn->add_constant(elfcpp::DT_DEBUG, 0); | |
1124 | } | |
1125 | } | |
1126 | ||
1127 | // Emit any relocs we saved in an attempt to avoid generating COPY | |
1128 | // relocs. | |
5a6f7e2d ILT |
1129 | if (this->copy_relocs_ == NULL) |
1130 | return; | |
1131 | if (this->copy_relocs_->any_to_emit()) | |
1132 | { | |
1133 | Reloc_section* rel_dyn = this->rel_dyn_section(layout); | |
1134 | this->copy_relocs_->emit(rel_dyn); | |
1135 | } | |
1136 | delete this->copy_relocs_; | |
1137 | this->copy_relocs_ = NULL; | |
1138 | } | |
1139 | ||
61ba1cf9 ILT |
1140 | // Perform a relocation. |
1141 | ||
ead1e424 | 1142 | inline bool |
92e059d8 | 1143 | Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo, |
ead1e424 | 1144 | Target_i386* target, |
92e059d8 ILT |
1145 | size_t relnum, |
1146 | const elfcpp::Rel<32, false>& rel, | |
1147 | unsigned int r_type, | |
c06b7b0b | 1148 | const Sized_symbol<32>* gsym, |
b8e6aad9 | 1149 | const Symbol_value<32>* psymval, |
92e059d8 ILT |
1150 | unsigned char* view, |
1151 | elfcpp::Elf_types<32>::Elf_Addr address, | |
1152 | off_t view_size) | |
61ba1cf9 | 1153 | { |
ead1e424 ILT |
1154 | if (this->skip_call_tls_get_addr_) |
1155 | { | |
1156 | if (r_type != elfcpp::R_386_PLT32 | |
1157 | || gsym == NULL | |
1158 | || strcmp(gsym->name(), "___tls_get_addr") != 0) | |
75f2446e ILT |
1159 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
1160 | _("missing expected TLS relocation")); | |
1161 | else | |
ead1e424 | 1162 | { |
75f2446e ILT |
1163 | this->skip_call_tls_get_addr_ = false; |
1164 | return false; | |
ead1e424 | 1165 | } |
ead1e424 ILT |
1166 | } |
1167 | ||
a3ad94ed | 1168 | // Pick the value to use for symbols defined in shared objects. |
b8e6aad9 | 1169 | Symbol_value<32> symval; |
8462ae85 | 1170 | if (gsym != NULL && gsym->is_from_dynobj() && gsym->has_plt_offset()) |
a3ad94ed | 1171 | { |
b8e6aad9 ILT |
1172 | symval.set_output_value(target->plt_section()->address() |
1173 | + gsym->plt_offset()); | |
1174 | psymval = &symval; | |
a3ad94ed ILT |
1175 | } |
1176 | ||
b8e6aad9 ILT |
1177 | const Sized_relobj<32, false>* object = relinfo->object; |
1178 | ||
61ba1cf9 ILT |
1179 | switch (r_type) |
1180 | { | |
1181 | case elfcpp::R_386_NONE: | |
92e059d8 ILT |
1182 | case elfcpp::R_386_GNU_VTINHERIT: |
1183 | case elfcpp::R_386_GNU_VTENTRY: | |
61ba1cf9 ILT |
1184 | break; |
1185 | ||
1186 | case elfcpp::R_386_32: | |
b8e6aad9 | 1187 | Relocate_functions<32, false>::rel32(view, object, psymval); |
61ba1cf9 ILT |
1188 | break; |
1189 | ||
1190 | case elfcpp::R_386_PC32: | |
b8e6aad9 | 1191 | Relocate_functions<32, false>::pcrel32(view, object, psymval, address); |
92e059d8 ILT |
1192 | break; |
1193 | ||
1194 | case elfcpp::R_386_16: | |
b8e6aad9 | 1195 | Relocate_functions<32, false>::rel16(view, object, psymval); |
92e059d8 ILT |
1196 | break; |
1197 | ||
1198 | case elfcpp::R_386_PC16: | |
b8e6aad9 | 1199 | Relocate_functions<32, false>::pcrel16(view, object, psymval, address); |
61ba1cf9 ILT |
1200 | break; |
1201 | ||
92e059d8 | 1202 | case elfcpp::R_386_8: |
b8e6aad9 | 1203 | Relocate_functions<32, false>::rel8(view, object, psymval); |
92e059d8 ILT |
1204 | break; |
1205 | ||
1206 | case elfcpp::R_386_PC8: | |
b8e6aad9 | 1207 | Relocate_functions<32, false>::pcrel8(view, object, psymval, address); |
92e059d8 ILT |
1208 | break; |
1209 | ||
ead1e424 | 1210 | case elfcpp::R_386_PLT32: |
a3ad94ed | 1211 | gold_assert(gsym->has_plt_offset() |
7e1edb90 | 1212 | || gsym->final_value_is_known()); |
b8e6aad9 | 1213 | Relocate_functions<32, false>::pcrel32(view, object, psymval, address); |
ead1e424 ILT |
1214 | break; |
1215 | ||
1216 | case elfcpp::R_386_GOT32: | |
1217 | // Local GOT offsets not yet supported. | |
a3ad94ed ILT |
1218 | gold_assert(gsym); |
1219 | gold_assert(gsym->has_got_offset()); | |
b8e6aad9 | 1220 | Relocate_functions<32, false>::rel32(view, gsym->got_offset()); |
ead1e424 ILT |
1221 | break; |
1222 | ||
1223 | case elfcpp::R_386_GOTOFF: | |
b8e6aad9 ILT |
1224 | { |
1225 | elfcpp::Elf_types<32>::Elf_Addr value; | |
1226 | value = (psymval->value(object, 0) | |
7e1edb90 | 1227 | - target->got_section(NULL, NULL)->address()); |
b8e6aad9 ILT |
1228 | Relocate_functions<32, false>::rel32(view, value); |
1229 | } | |
ead1e424 ILT |
1230 | break; |
1231 | ||
1232 | case elfcpp::R_386_GOTPC: | |
b8e6aad9 ILT |
1233 | { |
1234 | elfcpp::Elf_types<32>::Elf_Addr value; | |
7e1edb90 | 1235 | value = target->got_section(NULL, NULL)->address(); |
b8e6aad9 ILT |
1236 | Relocate_functions<32, false>::pcrel32(view, value, address); |
1237 | } | |
ead1e424 ILT |
1238 | break; |
1239 | ||
92e059d8 ILT |
1240 | case elfcpp::R_386_COPY: |
1241 | case elfcpp::R_386_GLOB_DAT: | |
1242 | case elfcpp::R_386_JUMP_SLOT: | |
1243 | case elfcpp::R_386_RELATIVE: | |
d61c17ea ILT |
1244 | // These are outstanding tls relocs, which are unexpected when |
1245 | // linking. | |
92e059d8 ILT |
1246 | case elfcpp::R_386_TLS_TPOFF: |
1247 | case elfcpp::R_386_TLS_DTPMOD32: | |
1248 | case elfcpp::R_386_TLS_DTPOFF32: | |
1249 | case elfcpp::R_386_TLS_TPOFF32: | |
1250 | case elfcpp::R_386_TLS_DESC: | |
75f2446e ILT |
1251 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
1252 | _("unexpected reloc %u in object file"), | |
1253 | r_type); | |
92e059d8 ILT |
1254 | break; |
1255 | ||
d61c17ea ILT |
1256 | // These are initial tls relocs, which are expected when |
1257 | // linking. | |
92e059d8 ILT |
1258 | case elfcpp::R_386_TLS_IE: |
1259 | case elfcpp::R_386_TLS_GOTIE: | |
1260 | case elfcpp::R_386_TLS_LE: | |
1261 | case elfcpp::R_386_TLS_GD: | |
1262 | case elfcpp::R_386_TLS_LDM: | |
1263 | case elfcpp::R_386_TLS_LDO_32: | |
1264 | case elfcpp::R_386_TLS_IE_32: | |
1265 | case elfcpp::R_386_TLS_LE_32: | |
1266 | case elfcpp::R_386_TLS_GOTDESC: | |
1267 | case elfcpp::R_386_TLS_DESC_CALL: | |
b8e6aad9 | 1268 | this->relocate_tls(relinfo, relnum, rel, r_type, gsym, psymval, view, |
ead1e424 | 1269 | address, view_size); |
92e059d8 ILT |
1270 | break; |
1271 | ||
92e059d8 ILT |
1272 | case elfcpp::R_386_32PLT: |
1273 | case elfcpp::R_386_TLS_GD_32: | |
1274 | case elfcpp::R_386_TLS_GD_PUSH: | |
1275 | case elfcpp::R_386_TLS_GD_CALL: | |
1276 | case elfcpp::R_386_TLS_GD_POP: | |
1277 | case elfcpp::R_386_TLS_LDM_32: | |
1278 | case elfcpp::R_386_TLS_LDM_PUSH: | |
1279 | case elfcpp::R_386_TLS_LDM_CALL: | |
1280 | case elfcpp::R_386_TLS_LDM_POP: | |
1281 | case elfcpp::R_386_USED_BY_INTEL_200: | |
61ba1cf9 | 1282 | default: |
75f2446e ILT |
1283 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
1284 | _("unsupported reloc %u"), | |
1285 | r_type); | |
92e059d8 ILT |
1286 | break; |
1287 | } | |
ead1e424 ILT |
1288 | |
1289 | return true; | |
92e059d8 ILT |
1290 | } |
1291 | ||
1292 | // Perform a TLS relocation. | |
1293 | ||
1294 | inline void | |
1295 | Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo, | |
1296 | size_t relnum, | |
1297 | const elfcpp::Rel<32, false>& rel, | |
1298 | unsigned int r_type, | |
c06b7b0b | 1299 | const Sized_symbol<32>* gsym, |
b8e6aad9 | 1300 | const Symbol_value<32>* psymval, |
92e059d8 ILT |
1301 | unsigned char* view, |
1302 | elfcpp::Elf_types<32>::Elf_Addr, | |
1303 | off_t view_size) | |
1304 | { | |
1305 | Output_segment* tls_segment = relinfo->layout->tls_segment(); | |
1306 | if (tls_segment == NULL) | |
1307 | { | |
75f2446e ILT |
1308 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
1309 | _("TLS reloc but no TLS segment")); | |
1310 | return; | |
92e059d8 ILT |
1311 | } |
1312 | ||
b8e6aad9 ILT |
1313 | elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(relinfo->object, 0); |
1314 | ||
a3ad94ed | 1315 | const bool is_final = (gsym == NULL |
7e1edb90 ILT |
1316 | ? !parameters->output_is_shared() |
1317 | : gsym->final_value_is_known()); | |
af6359d5 ILT |
1318 | const tls::Tls_optimization optimized_type |
1319 | = Target_i386::optimize_tls_reloc(is_final, r_type); | |
92e059d8 ILT |
1320 | switch (r_type) |
1321 | { | |
1322 | case elfcpp::R_386_TLS_LE_32: | |
1323 | value = tls_segment->vaddr() + tls_segment->memsz() - value; | |
1324 | Relocate_functions<32, false>::rel32(view, value); | |
1325 | break; | |
1326 | ||
1327 | case elfcpp::R_386_TLS_LE: | |
1328 | value = value - (tls_segment->vaddr() + tls_segment->memsz()); | |
1329 | Relocate_functions<32, false>::rel32(view, value); | |
1330 | break; | |
1331 | ||
1332 | case elfcpp::R_386_TLS_IE: | |
1333 | case elfcpp::R_386_TLS_GOTIE: | |
1334 | case elfcpp::R_386_TLS_IE_32: | |
af6359d5 | 1335 | if (optimized_type == tls::TLSOPT_TO_LE) |
92e059d8 ILT |
1336 | { |
1337 | Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment, | |
1338 | rel, r_type, value, view, | |
1339 | view_size); | |
1340 | break; | |
1341 | } | |
75f2446e ILT |
1342 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
1343 | _("unsupported reloc %u"), | |
1344 | r_type); | |
92e059d8 ILT |
1345 | break; |
1346 | ||
1347 | case elfcpp::R_386_TLS_GD: | |
af6359d5 | 1348 | if (optimized_type == tls::TLSOPT_TO_LE) |
ead1e424 ILT |
1349 | { |
1350 | this->tls_gd_to_le(relinfo, relnum, tls_segment, | |
1351 | rel, r_type, value, view, | |
1352 | view_size); | |
1353 | break; | |
1354 | } | |
75f2446e ILT |
1355 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
1356 | _("unsupported reloc %u"), | |
1357 | r_type); | |
ead1e424 ILT |
1358 | break; |
1359 | ||
92e059d8 | 1360 | case elfcpp::R_386_TLS_LDM: |
46cf9fa2 ILT |
1361 | if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN) |
1362 | { | |
75f2446e ILT |
1363 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
1364 | _("both SUN and GNU model " | |
1365 | "TLS relocations")); | |
1366 | break; | |
46cf9fa2 ILT |
1367 | } |
1368 | this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU; | |
af6359d5 | 1369 | if (optimized_type == tls::TLSOPT_TO_LE) |
46cf9fa2 ILT |
1370 | { |
1371 | this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, r_type, | |
1372 | value, view, view_size); | |
1373 | break; | |
1374 | } | |
75f2446e ILT |
1375 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
1376 | _("unsupported reloc %u"), | |
1377 | r_type); | |
46cf9fa2 ILT |
1378 | break; |
1379 | ||
92e059d8 | 1380 | case elfcpp::R_386_TLS_LDO_32: |
46cf9fa2 ILT |
1381 | // This reloc can appear in debugging sections, in which case we |
1382 | // won't see the TLS_LDM reloc. The local_dynamic_type field | |
1383 | // tells us this. | |
af6359d5 | 1384 | if (optimized_type != tls::TLSOPT_TO_LE |
46cf9fa2 ILT |
1385 | || this->local_dynamic_type_ == LOCAL_DYNAMIC_NONE) |
1386 | value = value - tls_segment->vaddr(); | |
1387 | else if (this->local_dynamic_type_ == LOCAL_DYNAMIC_GNU) | |
1388 | value = value - (tls_segment->vaddr() + tls_segment->memsz()); | |
1389 | else | |
1390 | value = tls_segment->vaddr() + tls_segment->memsz() - value; | |
1391 | Relocate_functions<32, false>::rel32(view, value); | |
1392 | break; | |
1393 | ||
92e059d8 ILT |
1394 | case elfcpp::R_386_TLS_GOTDESC: |
1395 | case elfcpp::R_386_TLS_DESC_CALL: | |
75f2446e ILT |
1396 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
1397 | _("unsupported reloc %u"), | |
1398 | r_type); | |
92e059d8 ILT |
1399 | break; |
1400 | } | |
1401 | } | |
1402 | ||
1403 | // Do a relocation in which we convert a TLS Initial-Exec to a | |
1404 | // Local-Exec. | |
1405 | ||
1406 | inline void | |
1407 | Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo, | |
1408 | size_t relnum, | |
1409 | Output_segment* tls_segment, | |
1410 | const elfcpp::Rel<32, false>& rel, | |
1411 | unsigned int r_type, | |
1412 | elfcpp::Elf_types<32>::Elf_Addr value, | |
1413 | unsigned char* view, | |
1414 | off_t view_size) | |
1415 | { | |
1416 | // We have to actually change the instructions, which means that we | |
1417 | // need to examine the opcodes to figure out which instruction we | |
1418 | // are looking at. | |
1419 | if (r_type == elfcpp::R_386_TLS_IE) | |
1420 | { | |
1421 | // movl %gs:XX,%eax ==> movl $YY,%eax | |
1422 | // movl %gs:XX,%reg ==> movl $YY,%reg | |
1423 | // addl %gs:XX,%reg ==> addl $YY,%reg | |
af6359d5 ILT |
1424 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -1); |
1425 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4); | |
92e059d8 ILT |
1426 | |
1427 | unsigned char op1 = view[-1]; | |
1428 | if (op1 == 0xa1) | |
1429 | { | |
1430 | // movl XX,%eax ==> movl $YY,%eax | |
1431 | view[-1] = 0xb8; | |
1432 | } | |
1433 | else | |
1434 | { | |
af6359d5 | 1435 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2); |
92e059d8 ILT |
1436 | |
1437 | unsigned char op2 = view[-2]; | |
1438 | if (op2 == 0x8b) | |
1439 | { | |
1440 | // movl XX,%reg ==> movl $YY,%reg | |
af6359d5 ILT |
1441 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
1442 | (op1 & 0xc7) == 0x05); | |
92e059d8 ILT |
1443 | view[-2] = 0xc7; |
1444 | view[-1] = 0xc0 | ((op1 >> 3) & 7); | |
1445 | } | |
1446 | else if (op2 == 0x03) | |
1447 | { | |
1448 | // addl XX,%reg ==> addl $YY,%reg | |
af6359d5 ILT |
1449 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
1450 | (op1 & 0xc7) == 0x05); | |
92e059d8 ILT |
1451 | view[-2] = 0x81; |
1452 | view[-1] = 0xc0 | ((op1 >> 3) & 7); | |
1453 | } | |
1454 | else | |
af6359d5 | 1455 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0); |
92e059d8 ILT |
1456 | } |
1457 | } | |
1458 | else | |
1459 | { | |
1460 | // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2 | |
1461 | // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2 | |
1462 | // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2 | |
af6359d5 ILT |
1463 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2); |
1464 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4); | |
92e059d8 ILT |
1465 | |
1466 | unsigned char op1 = view[-1]; | |
1467 | unsigned char op2 = view[-2]; | |
af6359d5 ILT |
1468 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
1469 | (op1 & 0xc0) == 0x80 && (op1 & 7) != 4); | |
92e059d8 ILT |
1470 | if (op2 == 0x8b) |
1471 | { | |
1472 | // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2 | |
1473 | view[-2] = 0xc7; | |
1474 | view[-1] = 0xc0 | ((op1 >> 3) & 7); | |
1475 | } | |
1476 | else if (op2 == 0x2b) | |
1477 | { | |
1478 | // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2 | |
1479 | view[-2] = 0x81; | |
1480 | view[-1] = 0xe8 | ((op1 >> 3) & 7); | |
1481 | } | |
1482 | else if (op2 == 0x03) | |
1483 | { | |
1484 | // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2 | |
1485 | view[-2] = 0x81; | |
1486 | view[-1] = 0xc0 | ((op1 >> 3) & 7); | |
1487 | } | |
1488 | else | |
af6359d5 | 1489 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0); |
92e059d8 ILT |
1490 | } |
1491 | ||
ead1e424 ILT |
1492 | value = tls_segment->vaddr() + tls_segment->memsz() - value; |
1493 | if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE) | |
1494 | value = - value; | |
92e059d8 ILT |
1495 | |
1496 | Relocate_functions<32, false>::rel32(view, value); | |
1497 | } | |
1498 | ||
e041f13d | 1499 | // Do a relocation in which we convert a TLS General-Dynamic to a |
ead1e424 ILT |
1500 | // Local-Exec. |
1501 | ||
1502 | inline void | |
1503 | Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo, | |
1504 | size_t relnum, | |
1505 | Output_segment* tls_segment, | |
1506 | const elfcpp::Rel<32, false>& rel, | |
1507 | unsigned int, | |
1508 | elfcpp::Elf_types<32>::Elf_Addr value, | |
1509 | unsigned char* view, | |
1510 | off_t view_size) | |
1511 | { | |
1512 | // leal foo(,%reg,1),%eax; call ___tls_get_addr | |
46cf9fa2 | 1513 | // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax |
ead1e424 ILT |
1514 | // leal foo(%reg),%eax; call ___tls_get_addr |
1515 | // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax | |
1516 | ||
af6359d5 ILT |
1517 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2); |
1518 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9); | |
ead1e424 ILT |
1519 | |
1520 | unsigned char op1 = view[-1]; | |
1521 | unsigned char op2 = view[-2]; | |
1522 | ||
af6359d5 ILT |
1523 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
1524 | op2 == 0x8d || op2 == 0x04); | |
1525 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8); | |
ead1e424 ILT |
1526 | |
1527 | int roff = 5; | |
1528 | ||
1529 | if (op2 == 0x04) | |
1530 | { | |
af6359d5 ILT |
1531 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3); |
1532 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d); | |
1533 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), | |
1534 | ((op1 & 0xc7) == 0x05 && op1 != (4 << 3))); | |
ead1e424 ILT |
1535 | memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12); |
1536 | } | |
1537 | else | |
1538 | { | |
af6359d5 ILT |
1539 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
1540 | (op1 & 0xf8) == 0x80 && (op1 & 7) != 4); | |
d61c17ea ILT |
1541 | if (static_cast<off_t>(rel.get_r_offset() + 9) < view_size |
1542 | && view[9] == 0x90) | |
ead1e424 ILT |
1543 | { |
1544 | // There is a trailing nop. Use the size byte subl. | |
1545 | memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12); | |
1546 | roff = 6; | |
1547 | } | |
1548 | else | |
1549 | { | |
1550 | // Use the five byte subl. | |
1551 | memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11); | |
1552 | } | |
1553 | } | |
1554 | ||
1555 | value = tls_segment->vaddr() + tls_segment->memsz() - value; | |
1556 | Relocate_functions<32, false>::rel32(view + roff, value); | |
1557 | ||
1558 | // The next reloc should be a PLT32 reloc against __tls_get_addr. | |
1559 | // We can skip it. | |
1560 | this->skip_call_tls_get_addr_ = true; | |
1561 | } | |
1562 | ||
46cf9fa2 ILT |
1563 | // Do a relocation in which we convert a TLS Local-Dynamic to a |
1564 | // Local-Exec. | |
1565 | ||
1566 | inline void | |
1567 | Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo, | |
1568 | size_t relnum, | |
1569 | Output_segment*, | |
1570 | const elfcpp::Rel<32, false>& rel, | |
1571 | unsigned int, | |
1572 | elfcpp::Elf_types<32>::Elf_Addr, | |
1573 | unsigned char* view, | |
1574 | off_t view_size) | |
1575 | { | |
1576 | // leal foo(%reg), %eax; call ___tls_get_addr | |
1577 | // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi | |
1578 | ||
af6359d5 ILT |
1579 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2); |
1580 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9); | |
46cf9fa2 ILT |
1581 | |
1582 | // FIXME: Does this test really always pass? | |
af6359d5 ILT |
1583 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
1584 | view[-2] == 0x8d && view[-1] == 0x83); | |
46cf9fa2 | 1585 | |
af6359d5 | 1586 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8); |
46cf9fa2 ILT |
1587 | |
1588 | memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11); | |
1589 | ||
1590 | // The next reloc should be a PLT32 reloc against __tls_get_addr. | |
1591 | // We can skip it. | |
1592 | this->skip_call_tls_get_addr_ = true; | |
1593 | } | |
1594 | ||
61ba1cf9 ILT |
1595 | // Relocate section data. |
1596 | ||
1597 | void | |
92e059d8 | 1598 | Target_i386::relocate_section(const Relocate_info<32, false>* relinfo, |
61ba1cf9 ILT |
1599 | unsigned int sh_type, |
1600 | const unsigned char* prelocs, | |
1601 | size_t reloc_count, | |
61ba1cf9 ILT |
1602 | unsigned char* view, |
1603 | elfcpp::Elf_types<32>::Elf_Addr address, | |
1604 | off_t view_size) | |
1605 | { | |
a3ad94ed | 1606 | gold_assert(sh_type == elfcpp::SHT_REL); |
61ba1cf9 | 1607 | |
ead1e424 ILT |
1608 | gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL, |
1609 | Target_i386::Relocate>( | |
92e059d8 | 1610 | relinfo, |
ead1e424 | 1611 | this, |
61ba1cf9 ILT |
1612 | prelocs, |
1613 | reloc_count, | |
61ba1cf9 ILT |
1614 | view, |
1615 | address, | |
1616 | view_size); | |
1617 | } | |
1618 | ||
ab5c9e90 ILT |
1619 | // Return the value to use for a dynamic which requires special |
1620 | // treatment. This is how we support equality comparisons of function | |
1621 | // pointers across shared library boundaries, as described in the | |
1622 | // processor specific ABI supplement. | |
1623 | ||
1624 | uint64_t | |
1625 | Target_i386::do_dynsym_value(const Symbol* gsym) const | |
1626 | { | |
1627 | gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset()); | |
1628 | return this->plt_section()->address() + gsym->plt_offset(); | |
1629 | } | |
1630 | ||
c51e6221 ILT |
1631 | // Return a string used to fill a code section with nops to take up |
1632 | // the specified length. | |
1633 | ||
1634 | std::string | |
1635 | Target_i386::do_code_fill(off_t length) | |
1636 | { | |
1637 | if (length >= 16) | |
1638 | { | |
1639 | // Build a jmp instruction to skip over the bytes. | |
1640 | unsigned char jmp[5]; | |
1641 | jmp[0] = 0xe9; | |
1642 | elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5); | |
1643 | return (std::string(reinterpret_cast<char*>(&jmp[0]), 5) | |
1644 | + std::string(length - 5, '\0')); | |
1645 | } | |
1646 | ||
1647 | // Nop sequences of various lengths. | |
1648 | const char nop1[1] = { 0x90 }; // nop | |
1649 | const char nop2[2] = { 0x66, 0x90 }; // xchg %ax %ax | |
1650 | const char nop3[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi | |
1651 | const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi | |
1652 | const char nop5[5] = { 0x90, 0x8d, 0x74, 0x26, // nop | |
1653 | 0x00 }; // leal 0(%esi,1),%esi | |
1654 | const char nop6[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi | |
1655 | 0x00, 0x00 }; | |
1656 | const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi | |
1657 | 0x00, 0x00, 0x00 }; | |
1658 | const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop | |
1659 | 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi | |
1660 | const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi | |
1661 | 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi | |
1662 | 0x00 }; | |
1663 | const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi | |
1664 | 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi | |
1665 | 0x00, 0x00 }; | |
1666 | const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi | |
1667 | 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi | |
1668 | 0x00, 0x00, 0x00 }; | |
1669 | const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi | |
1670 | 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi | |
1671 | 0x00, 0x00, 0x00, 0x00 }; | |
1672 | const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi | |
1673 | 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi | |
1674 | 0x27, 0x00, 0x00, 0x00, | |
1675 | 0x00 }; | |
1676 | const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi | |
1677 | 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi | |
1678 | 0xbc, 0x27, 0x00, 0x00, | |
1679 | 0x00, 0x00 }; | |
1680 | const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15 | |
1681 | 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,... | |
1682 | 0x90, 0x90, 0x90, 0x90, | |
1683 | 0x90, 0x90, 0x90 }; | |
1684 | ||
1685 | const char* nops[16] = { | |
1686 | NULL, | |
1687 | nop1, nop2, nop3, nop4, nop5, nop6, nop7, | |
1688 | nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15 | |
1689 | }; | |
1690 | ||
1691 | return std::string(nops[length], length); | |
1692 | } | |
1693 | ||
14bfc3f5 ILT |
1694 | // The selector for i386 object files. |
1695 | ||
1696 | class Target_selector_i386 : public Target_selector | |
1697 | { | |
1698 | public: | |
1699 | Target_selector_i386() | |
1700 | : Target_selector(elfcpp::EM_386, 32, false) | |
1701 | { } | |
1702 | ||
1703 | Target* | |
ead1e424 ILT |
1704 | recognize(int machine, int osabi, int abiversion); |
1705 | ||
1706 | private: | |
1707 | Target_i386* target_; | |
14bfc3f5 ILT |
1708 | }; |
1709 | ||
1710 | // Recognize an i386 object file when we already know that the machine | |
1711 | // number is EM_386. | |
1712 | ||
1713 | Target* | |
ead1e424 | 1714 | Target_selector_i386::recognize(int, int, int) |
14bfc3f5 | 1715 | { |
ead1e424 ILT |
1716 | if (this->target_ == NULL) |
1717 | this->target_ = new Target_i386(); | |
1718 | return this->target_; | |
14bfc3f5 ILT |
1719 | } |
1720 | ||
1721 | Target_selector_i386 target_selector_i386; | |
1722 | ||
1723 | } // End anonymous namespace. |