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14bfc3f5 ILT |
1 | // i386.cc -- i386 target support for gold. |
2 | ||
3 | #include "gold.h" | |
ead1e424 ILT |
4 | |
5 | #include <cstring> | |
6 | ||
14bfc3f5 | 7 | #include "elfcpp.h" |
92e059d8 | 8 | #include "reloc.h" |
61ba1cf9 ILT |
9 | #include "i386.h" |
10 | #include "object.h" | |
ead1e424 | 11 | #include "symtab.h" |
92e059d8 ILT |
12 | #include "layout.h" |
13 | #include "output.h" | |
14bfc3f5 | 14 | #include "target.h" |
61ba1cf9 | 15 | #include "target-reloc.h" |
14bfc3f5 ILT |
16 | #include "target-select.h" |
17 | ||
18 | namespace | |
19 | { | |
20 | ||
21 | using namespace gold; | |
22 | ||
23 | // The i386 target class. | |
24 | ||
25 | class Target_i386 : public Sized_target<32, false> | |
26 | { | |
27 | public: | |
28 | Target_i386() | |
ead1e424 ILT |
29 | : Sized_target<32, false>(&i386_info), |
30 | got_(NULL) | |
14bfc3f5 | 31 | { } |
75f65a3e | 32 | |
92e059d8 | 33 | // Scan the relocations to look for symbol adjustments. |
61ba1cf9 | 34 | void |
92e059d8 ILT |
35 | scan_relocs(const General_options& options, |
36 | Symbol_table* symtab, | |
ead1e424 | 37 | Layout* layout, |
f6ce93d6 | 38 | Sized_relobj<32, false>* object, |
92e059d8 ILT |
39 | unsigned int sh_type, |
40 | const unsigned char* prelocs, | |
41 | size_t reloc_count, | |
42 | size_t local_symbol_count, | |
43 | const unsigned char* plocal_symbols, | |
44 | Symbol** global_symbols); | |
61ba1cf9 | 45 | |
92e059d8 ILT |
46 | // Relocate a section. |
47 | void | |
48 | relocate_section(const Relocate_info<32, false>*, | |
49 | unsigned int sh_type, | |
50 | const unsigned char* prelocs, | |
51 | size_t reloc_count, | |
52 | unsigned char* view, | |
53 | elfcpp::Elf_types<32>::Elf_Addr view_address, | |
54 | off_t view_size); | |
55 | ||
56 | private: | |
57 | // The class which scans relocations. | |
58 | struct Scan | |
61ba1cf9 ILT |
59 | { |
60 | inline void | |
ead1e424 ILT |
61 | local(const General_options& options, Symbol_table* symtab, |
62 | Layout* layout, Target_i386* target, | |
f6ce93d6 | 63 | Sized_relobj<32, false>* object, |
92e059d8 ILT |
64 | const elfcpp::Rel<32, false>& reloc, unsigned int r_type, |
65 | const elfcpp::Sym<32, false>& lsym); | |
61ba1cf9 | 66 | |
92e059d8 | 67 | inline void |
ead1e424 ILT |
68 | global(const General_options& options, Symbol_table* symtab, |
69 | Layout* layout, Target_i386* target, | |
f6ce93d6 | 70 | Sized_relobj<32, false>* object, |
92e059d8 ILT |
71 | const elfcpp::Rel<32, false>& reloc, unsigned int r_type, |
72 | Symbol* gsym); | |
61ba1cf9 ILT |
73 | }; |
74 | ||
92e059d8 ILT |
75 | // The class which implements relocation. |
76 | class Relocate | |
77 | { | |
78 | public: | |
ead1e424 ILT |
79 | Relocate() |
80 | : skip_call_tls_get_addr_(false) | |
81 | { } | |
82 | ||
83 | ~Relocate() | |
84 | { | |
85 | if (this->skip_call_tls_get_addr_) | |
86 | { | |
87 | // FIXME: This needs to specify the location somehow. | |
88 | fprintf(stderr, _("%s: missing expected TLS relocation\n"), | |
89 | program_name); | |
90 | gold_exit(false); | |
91 | } | |
92 | } | |
93 | ||
94 | // Do a relocation. Return false if the caller should not issue | |
95 | // any warnings about this relocation. | |
96 | inline bool | |
97 | relocate(const Relocate_info<32, false>*, Target_i386*, size_t relnum, | |
92e059d8 ILT |
98 | const elfcpp::Rel<32, false>&, |
99 | unsigned int r_type, Sized_symbol<32>*, | |
100 | elfcpp::Elf_types<32>::Elf_Addr, | |
101 | unsigned char*, elfcpp::Elf_types<32>::Elf_Addr, | |
102 | off_t); | |
103 | ||
104 | private: | |
105 | // Do a TLS relocation. | |
ead1e424 | 106 | inline void |
92e059d8 ILT |
107 | relocate_tls(const Relocate_info<32, false>*, size_t relnum, |
108 | const elfcpp::Rel<32, false>&, | |
109 | unsigned int r_type, Sized_symbol<32>*, | |
110 | elfcpp::Elf_types<32>::Elf_Addr, | |
111 | unsigned char*, elfcpp::Elf_types<32>::Elf_Addr, off_t); | |
112 | ||
113 | // Do a TLS Initial-Exec to Local-Exec transition. | |
114 | static inline void | |
115 | tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum, | |
116 | Output_segment* tls_segment, | |
117 | const elfcpp::Rel<32, false>&, unsigned int r_type, | |
118 | elfcpp::Elf_types<32>::Elf_Addr value, | |
119 | unsigned char* view, | |
120 | off_t view_size); | |
121 | ||
ead1e424 ILT |
122 | // Do a TLS Global-Dynamic to Local-Exec transition. |
123 | inline void | |
124 | tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum, | |
125 | Output_segment* tls_segment, | |
126 | const elfcpp::Rel<32, false>&, unsigned int r_type, | |
127 | elfcpp::Elf_types<32>::Elf_Addr value, | |
128 | unsigned char* view, | |
129 | off_t view_size); | |
130 | ||
92e059d8 ILT |
131 | // Check the range for a TLS relocation. |
132 | static inline void | |
133 | check_range(const Relocate_info<32, false>*, size_t relnum, | |
134 | const elfcpp::Rel<32, false>&, off_t, off_t); | |
135 | ||
136 | // Check the validity of a TLS relocation. This is like assert. | |
137 | static inline void | |
138 | check_tls(const Relocate_info<32, false>*, size_t relnum, | |
139 | const elfcpp::Rel<32, false>&, bool); | |
ead1e424 ILT |
140 | |
141 | // This is set if we should skip the next reloc, which should be a | |
142 | // PLT32 reloc against ___tls_get_addr. | |
143 | bool skip_call_tls_get_addr_; | |
92e059d8 ILT |
144 | }; |
145 | ||
146 | // Adjust TLS relocation type based on the options and whether this | |
147 | // is a local symbol. | |
148 | static unsigned int | |
149 | optimize_tls_reloc(const General_options*, bool is_local, int r_type); | |
150 | ||
ead1e424 ILT |
151 | // Get the GOT section, creating it if necessary. |
152 | Output_section_got<32, false>* | |
153 | got_section(Symbol_table*, Layout*); | |
154 | ||
92e059d8 ILT |
155 | // Information about this specific target which we pass to the |
156 | // general Target structure. | |
75f65a3e | 157 | static const Target::Target_info i386_info; |
ead1e424 ILT |
158 | |
159 | // The GOT section. | |
160 | Output_section_got<32, false>* got_; | |
75f65a3e ILT |
161 | }; |
162 | ||
163 | const Target::Target_info Target_i386::i386_info = | |
164 | { | |
61ba1cf9 ILT |
165 | 32, // size |
166 | false, // is_big_endian | |
167 | elfcpp::EM_386, // machine_code | |
168 | false, // has_make_symbol | |
169 | false, // has_resolve, | |
170 | 0x08048000, // text_segment_address, | |
171 | 0x1000, // abi_pagesize | |
172 | 0x1000 // common_pagesize | |
14bfc3f5 ILT |
173 | }; |
174 | ||
ead1e424 ILT |
175 | // Get the GOT section, creating it if necessary. |
176 | ||
177 | Output_section_got<32, false>* | |
178 | Target_i386::got_section(Symbol_table* symtab, Layout* layout) | |
179 | { | |
180 | if (this->got_ == NULL) | |
181 | { | |
182 | this->got_ = new Output_section_got<32, false>(); | |
183 | ||
184 | assert(symtab != NULL && layout != NULL); | |
185 | layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS, | |
186 | elfcpp::SHF_ALLOC, this->got_); | |
187 | ||
188 | // The first three entries are reserved. | |
189 | this->got_->add_constant(0); | |
190 | this->got_->add_constant(0); | |
191 | this->got_->add_constant(0); | |
192 | ||
193 | // Define _GLOBAL_OFFSET_TABLE_ at the start of the section. | |
194 | symtab->define_in_output_data(this, "_GLOBAL_OFFSET_TABLE_", this->got_, | |
195 | 0, 0, elfcpp::STT_OBJECT, | |
196 | elfcpp::STB_GLOBAL, | |
197 | elfcpp::STV_HIDDEN, 0, | |
198 | false, false); | |
199 | } | |
200 | return this->got_; | |
201 | } | |
202 | ||
92e059d8 ILT |
203 | // Optimize the TLS relocation type based on what we know about the |
204 | // symbol. IS_LOCAL is true if this symbol can be resolved entirely | |
205 | // locally--i.e., does not have to be in the dynamic symbol table. | |
206 | ||
207 | unsigned int | |
208 | Target_i386::optimize_tls_reloc(const General_options* options, bool is_local, | |
209 | int r_type) | |
210 | { | |
211 | // If we are generating a shared library, then we can't do anything | |
212 | // in the linker. | |
213 | if (options->is_shared()) | |
214 | return r_type; | |
215 | ||
216 | switch (r_type) | |
217 | { | |
218 | case elfcpp::R_386_TLS_GD: | |
219 | case elfcpp::R_386_TLS_GOTDESC: | |
220 | case elfcpp::R_386_TLS_DESC_CALL: | |
221 | // These are Global-Dynamic which permits fully general TLS | |
222 | // access. Since we know that we are generating an executable, | |
223 | // we can convert this to Initial-Exec. If we also know that | |
224 | // this is a local symbol, we can further switch to Local-Exec. | |
225 | if (is_local) | |
226 | return elfcpp::R_386_TLS_LE_32; | |
227 | return elfcpp::R_386_TLS_IE_32; | |
228 | ||
229 | case elfcpp::R_386_TLS_LDM: | |
230 | // This is Local-Dynamic, which refers to a local symbol in the | |
231 | // dynamic TLS block. Since we know that we generating an | |
232 | // executable, we can switch to Local-Exec. | |
233 | return elfcpp::R_386_TLS_LE_32; | |
234 | ||
235 | case elfcpp::R_386_TLS_LDO_32: | |
236 | // Another type of Local-Dynamic relocation. | |
237 | return elfcpp::R_386_TLS_LE; | |
238 | ||
239 | case elfcpp::R_386_TLS_IE: | |
240 | case elfcpp::R_386_TLS_GOTIE: | |
241 | case elfcpp::R_386_TLS_IE_32: | |
242 | // These are Initial-Exec relocs which get the thread offset | |
243 | // from the GOT. If we know that we are linking against the | |
244 | // local symbol, we can switch to Local-Exec, which links the | |
245 | // thread offset into the instruction. | |
246 | if (is_local) | |
247 | return elfcpp::R_386_TLS_LE_32; | |
248 | return r_type; | |
249 | ||
250 | case elfcpp::R_386_TLS_LE: | |
251 | case elfcpp::R_386_TLS_LE_32: | |
252 | // When we already have Local-Exec, there is nothing further we | |
253 | // can do. | |
254 | return r_type; | |
255 | ||
256 | default: | |
257 | abort(); | |
258 | } | |
259 | } | |
260 | ||
261 | // Scan a relocation for a local symbol. | |
262 | ||
263 | inline void | |
264 | Target_i386::Scan::local(const General_options& options, | |
ead1e424 ILT |
265 | Symbol_table* symtab, |
266 | Layout* layout, | |
267 | Target_i386* target, | |
f6ce93d6 | 268 | Sized_relobj<32, false>* object, |
92e059d8 ILT |
269 | const elfcpp::Rel<32, false>&, unsigned int r_type, |
270 | const elfcpp::Sym<32, false>&) | |
271 | { | |
272 | switch (r_type) | |
273 | { | |
274 | case elfcpp::R_386_NONE: | |
275 | case elfcpp::R_386_GNU_VTINHERIT: | |
276 | case elfcpp::R_386_GNU_VTENTRY: | |
277 | break; | |
278 | ||
279 | case elfcpp::R_386_32: | |
280 | case elfcpp::R_386_16: | |
281 | case elfcpp::R_386_8: | |
282 | // FIXME: If we are generating a shared object we need to copy | |
283 | // this relocation into the object. | |
284 | break; | |
285 | ||
286 | case elfcpp::R_386_PC32: | |
287 | case elfcpp::R_386_PC16: | |
288 | case elfcpp::R_386_PC8: | |
289 | break; | |
290 | ||
ead1e424 ILT |
291 | case elfcpp::R_386_GOTOFF: |
292 | case elfcpp::R_386_GOTPC: | |
293 | // We need a GOT section. | |
294 | target->got_section(symtab, layout); | |
295 | break; | |
296 | ||
92e059d8 ILT |
297 | case elfcpp::R_386_COPY: |
298 | case elfcpp::R_386_GLOB_DAT: | |
299 | case elfcpp::R_386_JUMP_SLOT: | |
300 | case elfcpp::R_386_RELATIVE: | |
301 | case elfcpp::R_386_TLS_TPOFF: | |
302 | case elfcpp::R_386_TLS_DTPMOD32: | |
303 | case elfcpp::R_386_TLS_DTPOFF32: | |
304 | case elfcpp::R_386_TLS_TPOFF32: | |
305 | case elfcpp::R_386_TLS_DESC: | |
306 | fprintf(stderr, _("%s: %s: unexpected reloc %u in object file\n"), | |
307 | program_name, object->name().c_str(), r_type); | |
308 | gold_exit(false); | |
309 | break; | |
310 | ||
311 | case elfcpp::R_386_TLS_IE: | |
312 | case elfcpp::R_386_TLS_GOTIE: | |
313 | case elfcpp::R_386_TLS_LE: | |
314 | case elfcpp::R_386_TLS_GD: | |
315 | case elfcpp::R_386_TLS_LDM: | |
316 | case elfcpp::R_386_TLS_LDO_32: | |
317 | case elfcpp::R_386_TLS_IE_32: | |
318 | case elfcpp::R_386_TLS_LE_32: | |
319 | case elfcpp::R_386_TLS_GOTDESC: | |
320 | case elfcpp::R_386_TLS_DESC_CALL: | |
321 | r_type = Target_i386::optimize_tls_reloc(&options, true, r_type); | |
322 | switch (r_type) | |
323 | { | |
324 | case elfcpp::R_386_TLS_LE: | |
325 | case elfcpp::R_386_TLS_LE_32: | |
326 | // FIXME: If generating a shared object, we need to copy | |
327 | // this relocation into the object. | |
328 | break; | |
329 | ||
330 | case elfcpp::R_386_TLS_IE: | |
331 | case elfcpp::R_386_TLS_GOTIE: | |
332 | case elfcpp::R_386_TLS_GD: | |
333 | case elfcpp::R_386_TLS_LDM: | |
334 | case elfcpp::R_386_TLS_LDO_32: | |
335 | case elfcpp::R_386_TLS_IE_32: | |
336 | case elfcpp::R_386_TLS_GOTDESC: | |
337 | case elfcpp::R_386_TLS_DESC_CALL: | |
338 | fprintf(stderr, | |
339 | _("%s: %s: unsupported reloc %u against local symbol\n"), | |
340 | program_name, object->name().c_str(), r_type); | |
341 | break; | |
342 | } | |
343 | break; | |
344 | ||
345 | case elfcpp::R_386_GOT32: | |
346 | case elfcpp::R_386_PLT32: | |
92e059d8 ILT |
347 | case elfcpp::R_386_32PLT: |
348 | case elfcpp::R_386_TLS_GD_32: | |
349 | case elfcpp::R_386_TLS_GD_PUSH: | |
350 | case elfcpp::R_386_TLS_GD_CALL: | |
351 | case elfcpp::R_386_TLS_GD_POP: | |
352 | case elfcpp::R_386_TLS_LDM_32: | |
353 | case elfcpp::R_386_TLS_LDM_PUSH: | |
354 | case elfcpp::R_386_TLS_LDM_CALL: | |
355 | case elfcpp::R_386_TLS_LDM_POP: | |
356 | case elfcpp::R_386_USED_BY_INTEL_200: | |
357 | default: | |
358 | fprintf(stderr, _("%s: %s: unsupported reloc %u against local symbol\n"), | |
359 | program_name, object->name().c_str(), r_type); | |
360 | break; | |
361 | } | |
362 | } | |
363 | ||
364 | // Scan a relocation for a global symbol. | |
365 | ||
366 | inline void | |
367 | Target_i386::Scan::global(const General_options& options, | |
ead1e424 ILT |
368 | Symbol_table* symtab, |
369 | Layout* layout, | |
370 | Target_i386* target, | |
f6ce93d6 | 371 | Sized_relobj<32, false>* object, |
92e059d8 ILT |
372 | const elfcpp::Rel<32, false>&, unsigned int r_type, |
373 | Symbol* gsym) | |
374 | { | |
375 | switch (r_type) | |
376 | { | |
377 | case elfcpp::R_386_NONE: | |
378 | case elfcpp::R_386_GNU_VTINHERIT: | |
379 | case elfcpp::R_386_GNU_VTENTRY: | |
380 | break; | |
381 | ||
382 | case elfcpp::R_386_32: | |
383 | case elfcpp::R_386_PC32: | |
384 | case elfcpp::R_386_16: | |
385 | case elfcpp::R_386_PC16: | |
386 | case elfcpp::R_386_8: | |
387 | case elfcpp::R_386_PC8: | |
388 | // FIXME: If we are generating a shared object we may need to | |
389 | // copy this relocation into the object. If this symbol is | |
390 | // defined in a shared object, we may need to copy this | |
391 | // relocation in order to avoid a COPY relocation. | |
392 | break; | |
393 | ||
ead1e424 ILT |
394 | case elfcpp::R_386_GOT32: |
395 | // The symbol requires a GOT entry. | |
396 | if (!gsym->has_got_offset()) | |
397 | { | |
398 | Output_section_got<32, false>* got = target->got_section(symtab, | |
399 | layout); | |
400 | const unsigned int got_offset = got->add_global(gsym); | |
401 | gsym->set_got_offset(got_offset); | |
402 | ||
403 | // If this symbol is not resolved locally, we need to add a | |
404 | // dynamic relocation for it. | |
405 | if (!gsym->is_resolved_locally()) | |
406 | abort(); | |
407 | } | |
408 | break; | |
409 | ||
410 | case elfcpp::R_386_PLT32: | |
411 | // If the symbol is resolved locally, this is just a PC32 reloc. | |
412 | if (gsym->is_resolved_locally()) | |
413 | break; | |
414 | fprintf(stderr, | |
415 | _("%s: %s: unsupported reloc %u against global symbol %s\n"), | |
416 | program_name, object->name().c_str(), r_type, gsym->name()); | |
417 | break; | |
418 | ||
419 | case elfcpp::R_386_GOTOFF: | |
420 | case elfcpp::R_386_GOTPC: | |
421 | // We need a GOT section. | |
422 | target->got_section(symtab, layout); | |
423 | break; | |
424 | ||
92e059d8 ILT |
425 | case elfcpp::R_386_COPY: |
426 | case elfcpp::R_386_GLOB_DAT: | |
427 | case elfcpp::R_386_JUMP_SLOT: | |
428 | case elfcpp::R_386_RELATIVE: | |
429 | case elfcpp::R_386_TLS_TPOFF: | |
430 | case elfcpp::R_386_TLS_DTPMOD32: | |
431 | case elfcpp::R_386_TLS_DTPOFF32: | |
432 | case elfcpp::R_386_TLS_TPOFF32: | |
433 | case elfcpp::R_386_TLS_DESC: | |
434 | fprintf(stderr, _("%s: %s: unexpected reloc %u in object file\n"), | |
435 | program_name, object->name().c_str(), r_type); | |
436 | gold_exit(false); | |
437 | break; | |
438 | ||
439 | case elfcpp::R_386_TLS_IE: | |
440 | case elfcpp::R_386_TLS_GOTIE: | |
441 | case elfcpp::R_386_TLS_LE: | |
442 | case elfcpp::R_386_TLS_GD: | |
443 | case elfcpp::R_386_TLS_LDM: | |
444 | case elfcpp::R_386_TLS_LDO_32: | |
445 | case elfcpp::R_386_TLS_IE_32: | |
446 | case elfcpp::R_386_TLS_LE_32: | |
447 | case elfcpp::R_386_TLS_GOTDESC: | |
448 | case elfcpp::R_386_TLS_DESC_CALL: | |
449 | r_type = Target_i386::optimize_tls_reloc(&options, | |
ead1e424 | 450 | gsym->is_resolved_locally(), |
92e059d8 ILT |
451 | r_type); |
452 | switch (r_type) | |
453 | { | |
454 | case elfcpp::R_386_TLS_LE: | |
455 | case elfcpp::R_386_TLS_LE_32: | |
456 | // FIXME: If generating a shared object, we need to copy | |
457 | // this relocation into the object. | |
458 | break; | |
459 | ||
460 | case elfcpp::R_386_TLS_IE: | |
461 | case elfcpp::R_386_TLS_GOTIE: | |
462 | case elfcpp::R_386_TLS_GD: | |
463 | case elfcpp::R_386_TLS_LDM: | |
464 | case elfcpp::R_386_TLS_LDO_32: | |
465 | case elfcpp::R_386_TLS_IE_32: | |
466 | case elfcpp::R_386_TLS_GOTDESC: | |
467 | case elfcpp::R_386_TLS_DESC_CALL: | |
468 | fprintf(stderr, | |
469 | _("%s: %s: unsupported reloc %u against global symbol %s\n"), | |
470 | program_name, object->name().c_str(), r_type, gsym->name()); | |
471 | break; | |
472 | } | |
473 | break; | |
474 | ||
92e059d8 ILT |
475 | case elfcpp::R_386_32PLT: |
476 | case elfcpp::R_386_TLS_GD_32: | |
477 | case elfcpp::R_386_TLS_GD_PUSH: | |
478 | case elfcpp::R_386_TLS_GD_CALL: | |
479 | case elfcpp::R_386_TLS_GD_POP: | |
480 | case elfcpp::R_386_TLS_LDM_32: | |
481 | case elfcpp::R_386_TLS_LDM_PUSH: | |
482 | case elfcpp::R_386_TLS_LDM_CALL: | |
483 | case elfcpp::R_386_TLS_LDM_POP: | |
484 | case elfcpp::R_386_USED_BY_INTEL_200: | |
485 | default: | |
486 | fprintf(stderr, | |
487 | _("%s: %s: unsupported reloc %u against global symbol %s\n"), | |
488 | program_name, object->name().c_str(), r_type, gsym->name()); | |
489 | break; | |
490 | } | |
491 | } | |
492 | ||
493 | // Scan relocations for a section. | |
494 | ||
495 | void | |
496 | Target_i386::scan_relocs(const General_options& options, | |
497 | Symbol_table* symtab, | |
ead1e424 | 498 | Layout* layout, |
f6ce93d6 | 499 | Sized_relobj<32, false>* object, |
92e059d8 ILT |
500 | unsigned int sh_type, |
501 | const unsigned char* prelocs, | |
502 | size_t reloc_count, | |
503 | size_t local_symbol_count, | |
504 | const unsigned char* plocal_symbols, | |
505 | Symbol** global_symbols) | |
506 | { | |
507 | if (sh_type == elfcpp::SHT_RELA) | |
508 | { | |
509 | fprintf(stderr, _("%s: %s: unsupported RELA reloc section\n"), | |
510 | program_name, object->name().c_str()); | |
511 | gold_exit(false); | |
512 | } | |
513 | ||
ead1e424 ILT |
514 | gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL, |
515 | Target_i386::Scan>( | |
92e059d8 ILT |
516 | options, |
517 | symtab, | |
ead1e424 ILT |
518 | layout, |
519 | this, | |
92e059d8 ILT |
520 | object, |
521 | prelocs, | |
522 | reloc_count, | |
523 | local_symbol_count, | |
524 | plocal_symbols, | |
525 | global_symbols); | |
526 | } | |
527 | ||
61ba1cf9 ILT |
528 | // Perform a relocation. |
529 | ||
ead1e424 | 530 | inline bool |
92e059d8 | 531 | Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo, |
ead1e424 | 532 | Target_i386* target, |
92e059d8 ILT |
533 | size_t relnum, |
534 | const elfcpp::Rel<32, false>& rel, | |
535 | unsigned int r_type, | |
536 | Sized_symbol<32>* gsym, | |
537 | elfcpp::Elf_types<32>::Elf_Addr value, | |
538 | unsigned char* view, | |
539 | elfcpp::Elf_types<32>::Elf_Addr address, | |
540 | off_t view_size) | |
61ba1cf9 | 541 | { |
ead1e424 ILT |
542 | if (this->skip_call_tls_get_addr_) |
543 | { | |
544 | if (r_type != elfcpp::R_386_PLT32 | |
545 | || gsym == NULL | |
546 | || strcmp(gsym->name(), "___tls_get_addr") != 0) | |
547 | { | |
548 | fprintf(stderr, _("%s: %s: missing expected TLS relocation\n"), | |
549 | program_name, | |
550 | relinfo->location(relnum, rel.get_r_offset()).c_str()); | |
551 | gold_exit(false); | |
552 | } | |
553 | ||
554 | this->skip_call_tls_get_addr_ = false; | |
555 | ||
556 | return false; | |
557 | } | |
558 | ||
61ba1cf9 ILT |
559 | switch (r_type) |
560 | { | |
561 | case elfcpp::R_386_NONE: | |
92e059d8 ILT |
562 | case elfcpp::R_386_GNU_VTINHERIT: |
563 | case elfcpp::R_386_GNU_VTENTRY: | |
61ba1cf9 ILT |
564 | break; |
565 | ||
566 | case elfcpp::R_386_32: | |
92e059d8 | 567 | Relocate_functions<32, false>::rel32(view, value); |
61ba1cf9 ILT |
568 | break; |
569 | ||
570 | case elfcpp::R_386_PC32: | |
92e059d8 ILT |
571 | Relocate_functions<32, false>::pcrel32(view, value, address); |
572 | break; | |
573 | ||
574 | case elfcpp::R_386_16: | |
575 | Relocate_functions<32, false>::rel16(view, value); | |
576 | break; | |
577 | ||
578 | case elfcpp::R_386_PC16: | |
579 | Relocate_functions<32, false>::pcrel16(view, value, address); | |
61ba1cf9 ILT |
580 | break; |
581 | ||
92e059d8 ILT |
582 | case elfcpp::R_386_8: |
583 | Relocate_functions<32, false>::rel8(view, value); | |
584 | break; | |
585 | ||
586 | case elfcpp::R_386_PC8: | |
587 | Relocate_functions<32, false>::pcrel8(view, value, address); | |
588 | break; | |
589 | ||
ead1e424 ILT |
590 | case elfcpp::R_386_PLT32: |
591 | if (gsym->is_resolved_locally()) | |
592 | Relocate_functions<32, false>::pcrel32(view, value, address); | |
593 | else | |
594 | fprintf(stderr, _("%s: %s: unsupported reloc %u\n"), | |
595 | program_name, | |
596 | relinfo->location(relnum, rel.get_r_offset()).c_str(), | |
597 | r_type); | |
598 | break; | |
599 | ||
600 | case elfcpp::R_386_GOT32: | |
601 | // Local GOT offsets not yet supported. | |
602 | assert(gsym); | |
603 | assert(gsym->has_got_offset()); | |
604 | value = gsym->got_offset(); | |
605 | Relocate_functions<32, false>::rel32(view, value); | |
606 | break; | |
607 | ||
608 | case elfcpp::R_386_GOTOFF: | |
609 | value -= target->got_section(NULL, NULL)->address(); | |
610 | Relocate_functions<32, false>::rel32(view, value); | |
611 | break; | |
612 | ||
613 | case elfcpp::R_386_GOTPC: | |
614 | value = target->got_section(NULL, NULL)->address(); | |
615 | Relocate_functions<32, false>::pcrel32(view, value, address); | |
616 | break; | |
617 | ||
92e059d8 ILT |
618 | case elfcpp::R_386_COPY: |
619 | case elfcpp::R_386_GLOB_DAT: | |
620 | case elfcpp::R_386_JUMP_SLOT: | |
621 | case elfcpp::R_386_RELATIVE: | |
622 | case elfcpp::R_386_TLS_TPOFF: | |
623 | case elfcpp::R_386_TLS_DTPMOD32: | |
624 | case elfcpp::R_386_TLS_DTPOFF32: | |
625 | case elfcpp::R_386_TLS_TPOFF32: | |
626 | case elfcpp::R_386_TLS_DESC: | |
627 | fprintf(stderr, _("%s: %s: unexpected reloc %u in object file\n"), | |
628 | program_name, | |
629 | relinfo->location(relnum, rel.get_r_offset()).c_str(), | |
630 | r_type); | |
631 | gold_exit(false); | |
632 | break; | |
633 | ||
634 | case elfcpp::R_386_TLS_IE: | |
635 | case elfcpp::R_386_TLS_GOTIE: | |
636 | case elfcpp::R_386_TLS_LE: | |
637 | case elfcpp::R_386_TLS_GD: | |
638 | case elfcpp::R_386_TLS_LDM: | |
639 | case elfcpp::R_386_TLS_LDO_32: | |
640 | case elfcpp::R_386_TLS_IE_32: | |
641 | case elfcpp::R_386_TLS_LE_32: | |
642 | case elfcpp::R_386_TLS_GOTDESC: | |
643 | case elfcpp::R_386_TLS_DESC_CALL: | |
ead1e424 ILT |
644 | this->relocate_tls(relinfo, relnum, rel, r_type, gsym, value, view, |
645 | address, view_size); | |
92e059d8 ILT |
646 | break; |
647 | ||
92e059d8 ILT |
648 | case elfcpp::R_386_32PLT: |
649 | case elfcpp::R_386_TLS_GD_32: | |
650 | case elfcpp::R_386_TLS_GD_PUSH: | |
651 | case elfcpp::R_386_TLS_GD_CALL: | |
652 | case elfcpp::R_386_TLS_GD_POP: | |
653 | case elfcpp::R_386_TLS_LDM_32: | |
654 | case elfcpp::R_386_TLS_LDM_PUSH: | |
655 | case elfcpp::R_386_TLS_LDM_CALL: | |
656 | case elfcpp::R_386_TLS_LDM_POP: | |
657 | case elfcpp::R_386_USED_BY_INTEL_200: | |
61ba1cf9 ILT |
658 | default: |
659 | fprintf(stderr, _("%s: %s: unsupported reloc %u\n"), | |
92e059d8 ILT |
660 | program_name, |
661 | relinfo->location(relnum, rel.get_r_offset()).c_str(), | |
662 | r_type); | |
61ba1cf9 | 663 | // gold_exit(false); |
92e059d8 ILT |
664 | break; |
665 | } | |
ead1e424 ILT |
666 | |
667 | return true; | |
92e059d8 ILT |
668 | } |
669 | ||
670 | // Perform a TLS relocation. | |
671 | ||
672 | inline void | |
673 | Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo, | |
674 | size_t relnum, | |
675 | const elfcpp::Rel<32, false>& rel, | |
676 | unsigned int r_type, | |
677 | Sized_symbol<32>* gsym, | |
678 | elfcpp::Elf_types<32>::Elf_Addr value, | |
679 | unsigned char* view, | |
680 | elfcpp::Elf_types<32>::Elf_Addr, | |
681 | off_t view_size) | |
682 | { | |
683 | Output_segment* tls_segment = relinfo->layout->tls_segment(); | |
684 | if (tls_segment == NULL) | |
685 | { | |
686 | fprintf(stderr, _("%s: %s: TLS reloc but no TLS segment\n"), | |
687 | program_name, | |
688 | relinfo->location(relnum, rel.get_r_offset()).c_str()); | |
689 | gold_exit(false); | |
690 | } | |
691 | ||
ead1e424 | 692 | const bool is_local = gsym == NULL || gsym->is_resolved_locally(); |
92e059d8 ILT |
693 | const unsigned int opt_r_type = |
694 | Target_i386::optimize_tls_reloc(relinfo->options, is_local, r_type); | |
695 | switch (r_type) | |
696 | { | |
697 | case elfcpp::R_386_TLS_LE_32: | |
698 | value = tls_segment->vaddr() + tls_segment->memsz() - value; | |
699 | Relocate_functions<32, false>::rel32(view, value); | |
700 | break; | |
701 | ||
702 | case elfcpp::R_386_TLS_LE: | |
703 | value = value - (tls_segment->vaddr() + tls_segment->memsz()); | |
704 | Relocate_functions<32, false>::rel32(view, value); | |
705 | break; | |
706 | ||
707 | case elfcpp::R_386_TLS_IE: | |
708 | case elfcpp::R_386_TLS_GOTIE: | |
709 | case elfcpp::R_386_TLS_IE_32: | |
710 | if (opt_r_type == elfcpp::R_386_TLS_LE_32) | |
711 | { | |
712 | Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment, | |
713 | rel, r_type, value, view, | |
714 | view_size); | |
715 | break; | |
716 | } | |
717 | fprintf(stderr, _("%s: %s: unsupported reloc type %u\n"), | |
718 | program_name, | |
719 | relinfo->location(relnum, rel.get_r_offset()).c_str(), | |
720 | r_type); | |
721 | // gold_exit(false); | |
722 | break; | |
723 | ||
724 | case elfcpp::R_386_TLS_GD: | |
ead1e424 ILT |
725 | if (opt_r_type == elfcpp::R_386_TLS_LE_32) |
726 | { | |
727 | this->tls_gd_to_le(relinfo, relnum, tls_segment, | |
728 | rel, r_type, value, view, | |
729 | view_size); | |
730 | break; | |
731 | } | |
732 | fprintf(stderr, _("%s: %s: unsupported reloc %u\n"), | |
733 | program_name, | |
734 | relinfo->location(relnum, rel.get_r_offset()).c_str(), | |
735 | r_type); | |
736 | // gold_exit(false); | |
737 | break; | |
738 | ||
92e059d8 ILT |
739 | case elfcpp::R_386_TLS_LDM: |
740 | case elfcpp::R_386_TLS_LDO_32: | |
741 | case elfcpp::R_386_TLS_GOTDESC: | |
742 | case elfcpp::R_386_TLS_DESC_CALL: | |
743 | fprintf(stderr, _("%s: %s: unsupported reloc %u\n"), | |
744 | program_name, | |
745 | relinfo->location(relnum, rel.get_r_offset()).c_str(), | |
746 | r_type); | |
747 | // gold_exit(false); | |
748 | break; | |
749 | } | |
750 | } | |
751 | ||
752 | // Do a relocation in which we convert a TLS Initial-Exec to a | |
753 | // Local-Exec. | |
754 | ||
755 | inline void | |
756 | Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo, | |
757 | size_t relnum, | |
758 | Output_segment* tls_segment, | |
759 | const elfcpp::Rel<32, false>& rel, | |
760 | unsigned int r_type, | |
761 | elfcpp::Elf_types<32>::Elf_Addr value, | |
762 | unsigned char* view, | |
763 | off_t view_size) | |
764 | { | |
765 | // We have to actually change the instructions, which means that we | |
766 | // need to examine the opcodes to figure out which instruction we | |
767 | // are looking at. | |
768 | if (r_type == elfcpp::R_386_TLS_IE) | |
769 | { | |
770 | // movl %gs:XX,%eax ==> movl $YY,%eax | |
771 | // movl %gs:XX,%reg ==> movl $YY,%reg | |
772 | // addl %gs:XX,%reg ==> addl $YY,%reg | |
773 | Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, -1); | |
774 | Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, 4); | |
775 | ||
776 | unsigned char op1 = view[-1]; | |
777 | if (op1 == 0xa1) | |
778 | { | |
779 | // movl XX,%eax ==> movl $YY,%eax | |
780 | view[-1] = 0xb8; | |
781 | } | |
782 | else | |
783 | { | |
784 | Target_i386::Relocate::check_range(relinfo, relnum, rel, | |
785 | view_size, -2); | |
786 | ||
787 | unsigned char op2 = view[-2]; | |
788 | if (op2 == 0x8b) | |
789 | { | |
790 | // movl XX,%reg ==> movl $YY,%reg | |
791 | Target_i386::Relocate::check_tls(relinfo, relnum, rel, | |
792 | (op1 & 0xc7) == 0x05); | |
793 | view[-2] = 0xc7; | |
794 | view[-1] = 0xc0 | ((op1 >> 3) & 7); | |
795 | } | |
796 | else if (op2 == 0x03) | |
797 | { | |
798 | // addl XX,%reg ==> addl $YY,%reg | |
799 | Target_i386::Relocate::check_tls(relinfo, relnum, rel, | |
800 | (op1 & 0xc7) == 0x05); | |
801 | view[-2] = 0x81; | |
802 | view[-1] = 0xc0 | ((op1 >> 3) & 7); | |
803 | } | |
804 | else | |
805 | Target_i386::Relocate::check_tls(relinfo, relnum, rel, 0); | |
806 | } | |
807 | } | |
808 | else | |
809 | { | |
810 | // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2 | |
811 | // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2 | |
812 | // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2 | |
813 | Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, -2); | |
814 | Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, 4); | |
815 | ||
816 | unsigned char op1 = view[-1]; | |
817 | unsigned char op2 = view[-2]; | |
818 | Target_i386::Relocate::check_tls(relinfo, relnum, rel, | |
819 | (op1 & 0xc0) == 0x80 && (op1 & 7) != 4); | |
820 | if (op2 == 0x8b) | |
821 | { | |
822 | // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2 | |
823 | view[-2] = 0xc7; | |
824 | view[-1] = 0xc0 | ((op1 >> 3) & 7); | |
825 | } | |
826 | else if (op2 == 0x2b) | |
827 | { | |
828 | // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2 | |
829 | view[-2] = 0x81; | |
830 | view[-1] = 0xe8 | ((op1 >> 3) & 7); | |
831 | } | |
832 | else if (op2 == 0x03) | |
833 | { | |
834 | // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2 | |
835 | view[-2] = 0x81; | |
836 | view[-1] = 0xc0 | ((op1 >> 3) & 7); | |
837 | } | |
838 | else | |
839 | Target_i386::Relocate::check_tls(relinfo, relnum, rel, 0); | |
840 | } | |
841 | ||
ead1e424 ILT |
842 | value = tls_segment->vaddr() + tls_segment->memsz() - value; |
843 | if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE) | |
844 | value = - value; | |
92e059d8 ILT |
845 | |
846 | Relocate_functions<32, false>::rel32(view, value); | |
847 | } | |
848 | ||
ead1e424 ILT |
849 | // Do a relocation in which we convert a TLS Global-Dynamic to a |
850 | // Local-Exec. | |
851 | ||
852 | inline void | |
853 | Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo, | |
854 | size_t relnum, | |
855 | Output_segment* tls_segment, | |
856 | const elfcpp::Rel<32, false>& rel, | |
857 | unsigned int, | |
858 | elfcpp::Elf_types<32>::Elf_Addr value, | |
859 | unsigned char* view, | |
860 | off_t view_size) | |
861 | { | |
862 | // leal foo(,%reg,1),%eax; call ___tls_get_addr | |
863 | // ==> movl %gs,0,%eax; subl $foo@tpoff,%eax | |
864 | // leal foo(%reg),%eax; call ___tls_get_addr | |
865 | // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax | |
866 | ||
867 | Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, -2); | |
868 | Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, 9); | |
869 | ||
870 | unsigned char op1 = view[-1]; | |
871 | unsigned char op2 = view[-2]; | |
872 | ||
873 | Target_i386::Relocate::check_tls(relinfo, relnum, rel, | |
874 | op2 == 0x8d || op2 == 0x04); | |
875 | Target_i386::Relocate::check_tls(relinfo, relnum, rel, | |
876 | view[4] == 0xe8); | |
877 | ||
878 | int roff = 5; | |
879 | ||
880 | if (op2 == 0x04) | |
881 | { | |
882 | Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, -3); | |
883 | Target_i386::Relocate::check_tls(relinfo, relnum, rel, | |
884 | view[-3] == 0x8d); | |
885 | Target_i386::Relocate::check_tls(relinfo, relnum, rel, | |
886 | ((op1 & 0xc7) == 0x05 | |
887 | && op1 != (4 << 3))); | |
888 | memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12); | |
889 | } | |
890 | else | |
891 | { | |
892 | Target_i386::Relocate::check_tls(relinfo, relnum, rel, | |
893 | (op1 & 0xf8) == 0x80 && (op1 & 7) != 4); | |
894 | if (rel.get_r_offset() + 9 < view_size && view[9] == 0x90) | |
895 | { | |
896 | // There is a trailing nop. Use the size byte subl. | |
897 | memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12); | |
898 | roff = 6; | |
899 | } | |
900 | else | |
901 | { | |
902 | // Use the five byte subl. | |
903 | memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11); | |
904 | } | |
905 | } | |
906 | ||
907 | value = tls_segment->vaddr() + tls_segment->memsz() - value; | |
908 | Relocate_functions<32, false>::rel32(view + roff, value); | |
909 | ||
910 | // The next reloc should be a PLT32 reloc against __tls_get_addr. | |
911 | // We can skip it. | |
912 | this->skip_call_tls_get_addr_ = true; | |
913 | } | |
914 | ||
92e059d8 ILT |
915 | // Check the range for a TLS relocation. |
916 | ||
917 | inline void | |
918 | Target_i386::Relocate::check_range(const Relocate_info<32, false>* relinfo, | |
919 | size_t relnum, | |
920 | const elfcpp::Rel<32, false>& rel, | |
921 | off_t view_size, off_t off) | |
922 | { | |
923 | off_t offset = rel.get_r_offset() + off; | |
924 | if (offset < 0 || offset > view_size) | |
925 | { | |
926 | fprintf(stderr, _("%s: %s: TLS relocation out of range\n"), | |
927 | program_name, | |
928 | relinfo->location(relnum, rel.get_r_offset()).c_str()); | |
929 | gold_exit(false); | |
930 | } | |
931 | } | |
932 | ||
933 | // Check the validity of a TLS relocation. This is like assert. | |
934 | ||
935 | inline void | |
936 | Target_i386::Relocate::check_tls(const Relocate_info<32, false>* relinfo, | |
937 | size_t relnum, | |
938 | const elfcpp::Rel<32, false>& rel, | |
939 | bool valid) | |
940 | { | |
941 | if (!valid) | |
942 | { | |
943 | fprintf(stderr, | |
944 | _("%s: %s: TLS relocation against invalid instruction\n"), | |
945 | program_name, | |
946 | relinfo->location(relnum, rel.get_r_offset()).c_str()); | |
947 | gold_exit(false); | |
61ba1cf9 ILT |
948 | } |
949 | } | |
950 | ||
951 | // Relocate section data. | |
952 | ||
953 | void | |
92e059d8 | 954 | Target_i386::relocate_section(const Relocate_info<32, false>* relinfo, |
61ba1cf9 ILT |
955 | unsigned int sh_type, |
956 | const unsigned char* prelocs, | |
957 | size_t reloc_count, | |
61ba1cf9 ILT |
958 | unsigned char* view, |
959 | elfcpp::Elf_types<32>::Elf_Addr address, | |
960 | off_t view_size) | |
961 | { | |
92e059d8 | 962 | assert(sh_type == elfcpp::SHT_REL); |
61ba1cf9 | 963 | |
ead1e424 ILT |
964 | gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL, |
965 | Target_i386::Relocate>( | |
92e059d8 | 966 | relinfo, |
ead1e424 | 967 | this, |
61ba1cf9 ILT |
968 | prelocs, |
969 | reloc_count, | |
61ba1cf9 ILT |
970 | view, |
971 | address, | |
972 | view_size); | |
973 | } | |
974 | ||
14bfc3f5 ILT |
975 | // The selector for i386 object files. |
976 | ||
977 | class Target_selector_i386 : public Target_selector | |
978 | { | |
979 | public: | |
980 | Target_selector_i386() | |
981 | : Target_selector(elfcpp::EM_386, 32, false) | |
982 | { } | |
983 | ||
984 | Target* | |
ead1e424 ILT |
985 | recognize(int machine, int osabi, int abiversion); |
986 | ||
987 | private: | |
988 | Target_i386* target_; | |
14bfc3f5 ILT |
989 | }; |
990 | ||
991 | // Recognize an i386 object file when we already know that the machine | |
992 | // number is EM_386. | |
993 | ||
994 | Target* | |
ead1e424 | 995 | Target_selector_i386::recognize(int, int, int) |
14bfc3f5 | 996 | { |
ead1e424 ILT |
997 | if (this->target_ == NULL) |
998 | this->target_ = new Target_i386(); | |
999 | return this->target_; | |
14bfc3f5 ILT |
1000 | } |
1001 | ||
1002 | Target_selector_i386 target_selector_i386; | |
1003 | ||
1004 | } // End anonymous namespace. |