Commit | Line | Data |
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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" |
7e1edb90 | 8 | #include "parameters.h" |
92e059d8 | 9 | #include "reloc.h" |
61ba1cf9 ILT |
10 | #include "i386.h" |
11 | #include "object.h" | |
ead1e424 | 12 | #include "symtab.h" |
92e059d8 ILT |
13 | #include "layout.h" |
14 | #include "output.h" | |
14bfc3f5 | 15 | #include "target.h" |
61ba1cf9 | 16 | #include "target-reloc.h" |
14bfc3f5 ILT |
17 | #include "target-select.h" |
18 | ||
19 | namespace | |
20 | { | |
21 | ||
22 | using namespace gold; | |
23 | ||
a3ad94ed ILT |
24 | class Output_data_plt_i386; |
25 | ||
14bfc3f5 ILT |
26 | // The i386 target class. |
27 | ||
28 | class Target_i386 : public Sized_target<32, false> | |
29 | { | |
30 | public: | |
5a6f7e2d ILT |
31 | typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section; |
32 | ||
14bfc3f5 | 33 | Target_i386() |
ead1e424 | 34 | : Sized_target<32, false>(&i386_info), |
5a6f7e2d ILT |
35 | got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL), |
36 | copy_relocs_(NULL), dynbss_(NULL) | |
14bfc3f5 | 37 | { } |
75f65a3e | 38 | |
92e059d8 | 39 | // Scan the relocations to look for symbol adjustments. |
61ba1cf9 | 40 | void |
92e059d8 ILT |
41 | scan_relocs(const General_options& options, |
42 | Symbol_table* symtab, | |
ead1e424 | 43 | Layout* layout, |
f6ce93d6 | 44 | Sized_relobj<32, false>* object, |
a3ad94ed | 45 | unsigned int data_shndx, |
92e059d8 ILT |
46 | unsigned int sh_type, |
47 | const unsigned char* prelocs, | |
48 | size_t reloc_count, | |
49 | size_t local_symbol_count, | |
50 | const unsigned char* plocal_symbols, | |
51 | Symbol** global_symbols); | |
61ba1cf9 | 52 | |
5a6f7e2d ILT |
53 | // Finalize the sections. |
54 | void | |
7e1edb90 | 55 | do_finalize_sections(Layout*); |
5a6f7e2d | 56 | |
92e059d8 ILT |
57 | // Relocate a section. |
58 | void | |
59 | relocate_section(const Relocate_info<32, false>*, | |
60 | unsigned int sh_type, | |
61 | const unsigned char* prelocs, | |
62 | size_t reloc_count, | |
63 | unsigned char* view, | |
64 | elfcpp::Elf_types<32>::Elf_Addr view_address, | |
65 | off_t view_size); | |
66 | ||
c51e6221 ILT |
67 | // Return a string used to fill a code section with nops. |
68 | std::string | |
69 | do_code_fill(off_t length); | |
70 | ||
92e059d8 ILT |
71 | private: |
72 | // The class which scans relocations. | |
73 | struct Scan | |
61ba1cf9 ILT |
74 | { |
75 | inline void | |
ead1e424 ILT |
76 | local(const General_options& options, Symbol_table* symtab, |
77 | Layout* layout, Target_i386* target, | |
f6ce93d6 | 78 | Sized_relobj<32, false>* object, |
a3ad94ed | 79 | unsigned int data_shndx, |
92e059d8 ILT |
80 | const elfcpp::Rel<32, false>& reloc, unsigned int r_type, |
81 | const elfcpp::Sym<32, false>& lsym); | |
61ba1cf9 | 82 | |
92e059d8 | 83 | inline void |
ead1e424 ILT |
84 | global(const General_options& options, Symbol_table* symtab, |
85 | Layout* layout, Target_i386* target, | |
f6ce93d6 | 86 | Sized_relobj<32, false>* object, |
a3ad94ed | 87 | unsigned int data_shndx, |
92e059d8 ILT |
88 | const elfcpp::Rel<32, false>& reloc, unsigned int r_type, |
89 | Symbol* gsym); | |
61ba1cf9 ILT |
90 | }; |
91 | ||
92e059d8 ILT |
92 | // The class which implements relocation. |
93 | class Relocate | |
94 | { | |
95 | public: | |
ead1e424 ILT |
96 | Relocate() |
97 | : skip_call_tls_get_addr_(false) | |
98 | { } | |
99 | ||
100 | ~Relocate() | |
101 | { | |
102 | if (this->skip_call_tls_get_addr_) | |
103 | { | |
104 | // FIXME: This needs to specify the location somehow. | |
105 | fprintf(stderr, _("%s: missing expected TLS relocation\n"), | |
106 | program_name); | |
107 | gold_exit(false); | |
108 | } | |
109 | } | |
110 | ||
111 | // Do a relocation. Return false if the caller should not issue | |
112 | // any warnings about this relocation. | |
113 | inline bool | |
114 | relocate(const Relocate_info<32, false>*, Target_i386*, size_t relnum, | |
92e059d8 | 115 | const elfcpp::Rel<32, false>&, |
c06b7b0b | 116 | unsigned int r_type, const Sized_symbol<32>*, |
b8e6aad9 | 117 | const Symbol_value<32>*, |
92e059d8 ILT |
118 | unsigned char*, elfcpp::Elf_types<32>::Elf_Addr, |
119 | off_t); | |
120 | ||
121 | private: | |
122 | // Do a TLS relocation. | |
ead1e424 | 123 | inline void |
92e059d8 ILT |
124 | relocate_tls(const Relocate_info<32, false>*, size_t relnum, |
125 | const elfcpp::Rel<32, false>&, | |
c06b7b0b | 126 | unsigned int r_type, const Sized_symbol<32>*, |
b8e6aad9 | 127 | const Symbol_value<32>*, |
92e059d8 ILT |
128 | unsigned char*, elfcpp::Elf_types<32>::Elf_Addr, off_t); |
129 | ||
130 | // Do a TLS Initial-Exec to Local-Exec transition. | |
131 | static inline void | |
132 | tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum, | |
133 | Output_segment* tls_segment, | |
134 | const elfcpp::Rel<32, false>&, unsigned int r_type, | |
135 | elfcpp::Elf_types<32>::Elf_Addr value, | |
136 | unsigned char* view, | |
137 | off_t view_size); | |
138 | ||
ead1e424 ILT |
139 | // Do a TLS Global-Dynamic to Local-Exec transition. |
140 | inline void | |
141 | tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum, | |
142 | Output_segment* tls_segment, | |
143 | const elfcpp::Rel<32, false>&, unsigned int r_type, | |
144 | elfcpp::Elf_types<32>::Elf_Addr value, | |
145 | unsigned char* view, | |
146 | off_t view_size); | |
147 | ||
92e059d8 ILT |
148 | // Check the range for a TLS relocation. |
149 | static inline void | |
150 | check_range(const Relocate_info<32, false>*, size_t relnum, | |
151 | const elfcpp::Rel<32, false>&, off_t, off_t); | |
152 | ||
153 | // Check the validity of a TLS relocation. This is like assert. | |
154 | static inline void | |
155 | check_tls(const Relocate_info<32, false>*, size_t relnum, | |
156 | const elfcpp::Rel<32, false>&, bool); | |
ead1e424 ILT |
157 | |
158 | // This is set if we should skip the next reloc, which should be a | |
159 | // PLT32 reloc against ___tls_get_addr. | |
160 | bool skip_call_tls_get_addr_; | |
92e059d8 ILT |
161 | }; |
162 | ||
163 | // Adjust TLS relocation type based on the options and whether this | |
164 | // is a local symbol. | |
165 | static unsigned int | |
7e1edb90 | 166 | optimize_tls_reloc(bool is_final, int r_type); |
92e059d8 | 167 | |
ead1e424 | 168 | // Get the GOT section, creating it if necessary. |
dbe717ef | 169 | Output_data_got<32, false>* |
7e1edb90 | 170 | got_section(Symbol_table*, Layout*); |
a3ad94ed ILT |
171 | |
172 | // Create a PLT entry for a global symbol. | |
173 | void | |
7e1edb90 | 174 | make_plt_entry(Symbol_table*, Layout*, Symbol*); |
a3ad94ed ILT |
175 | |
176 | // Get the PLT section. | |
177 | Output_data_plt_i386* | |
178 | plt_section() const | |
179 | { | |
180 | gold_assert(this->plt_ != NULL); | |
181 | return this->plt_; | |
182 | } | |
183 | ||
5a6f7e2d ILT |
184 | // Get the dynamic reloc section, creating it if necessary. |
185 | Reloc_section* | |
186 | rel_dyn_section(Layout*); | |
187 | ||
a3ad94ed ILT |
188 | // Copy a relocation against a global symbol. |
189 | void | |
5a6f7e2d ILT |
190 | copy_reloc(const General_options*, Symbol_table*, Layout*, |
191 | Sized_relobj<32, false>*, unsigned int, | |
a3ad94ed | 192 | Symbol*, const elfcpp::Rel<32, false>&); |
ead1e424 | 193 | |
92e059d8 ILT |
194 | // Information about this specific target which we pass to the |
195 | // general Target structure. | |
75f65a3e | 196 | static const Target::Target_info i386_info; |
ead1e424 ILT |
197 | |
198 | // The GOT section. | |
dbe717ef | 199 | Output_data_got<32, false>* got_; |
a3ad94ed ILT |
200 | // The PLT section. |
201 | Output_data_plt_i386* plt_; | |
202 | // The GOT PLT section. | |
203 | Output_data_space* got_plt_; | |
5a6f7e2d ILT |
204 | // The dynamic reloc section. |
205 | Reloc_section* rel_dyn_; | |
206 | // Relocs saved to avoid a COPY reloc. | |
207 | Copy_relocs<32, false>* copy_relocs_; | |
208 | // Space for variables copied with a COPY reloc. | |
209 | Output_data_space* dynbss_; | |
75f65a3e ILT |
210 | }; |
211 | ||
212 | const Target::Target_info Target_i386::i386_info = | |
213 | { | |
61ba1cf9 ILT |
214 | 32, // size |
215 | false, // is_big_endian | |
216 | elfcpp::EM_386, // machine_code | |
217 | false, // has_make_symbol | |
dbe717ef | 218 | false, // has_resolve |
c51e6221 | 219 | true, // has_code_fill |
dbe717ef ILT |
220 | "/usr/lib/libc.so.1", // dynamic_linker |
221 | 0x08048000, // text_segment_address | |
61ba1cf9 ILT |
222 | 0x1000, // abi_pagesize |
223 | 0x1000 // common_pagesize | |
14bfc3f5 ILT |
224 | }; |
225 | ||
ead1e424 ILT |
226 | // Get the GOT section, creating it if necessary. |
227 | ||
dbe717ef | 228 | Output_data_got<32, false>* |
7e1edb90 | 229 | Target_i386::got_section(Symbol_table* symtab, Layout* layout) |
ead1e424 ILT |
230 | { |
231 | if (this->got_ == NULL) | |
232 | { | |
7e1edb90 | 233 | gold_assert(symtab != NULL && layout != NULL); |
a3ad94ed | 234 | |
7e1edb90 | 235 | this->got_ = new Output_data_got<32, false>(); |
ead1e424 | 236 | |
ead1e424 | 237 | layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS, |
16649710 ILT |
238 | elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE, |
239 | this->got_); | |
ead1e424 | 240 | |
a3ad94ed ILT |
241 | // The old GNU linker creates a .got.plt section. We just |
242 | // create another set of data in the .got section. Note that we | |
243 | // always create a PLT if we create a GOT, although the PLT | |
244 | // might be empty. | |
245 | this->got_plt_ = new Output_data_space(4); | |
246 | layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS, | |
16649710 ILT |
247 | elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE, |
248 | this->got_plt_); | |
a3ad94ed | 249 | |
ead1e424 | 250 | // The first three entries are reserved. |
a3ad94ed | 251 | this->got_plt_->set_space_size(3 * 4); |
ead1e424 | 252 | |
a3ad94ed | 253 | // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT. |
14b31740 | 254 | symtab->define_in_output_data(this, "_GLOBAL_OFFSET_TABLE_", NULL, |
a3ad94ed | 255 | this->got_plt_, |
ead1e424 | 256 | 0, 0, elfcpp::STT_OBJECT, |
16649710 | 257 | elfcpp::STB_LOCAL, |
ead1e424 ILT |
258 | elfcpp::STV_HIDDEN, 0, |
259 | false, false); | |
260 | } | |
a3ad94ed | 261 | |
ead1e424 ILT |
262 | return this->got_; |
263 | } | |
264 | ||
5a6f7e2d ILT |
265 | // Get the dynamic reloc section, creating it if necessary. |
266 | ||
267 | Target_i386::Reloc_section* | |
268 | Target_i386::rel_dyn_section(Layout* layout) | |
269 | { | |
270 | if (this->rel_dyn_ == NULL) | |
271 | { | |
272 | gold_assert(layout != NULL); | |
273 | this->rel_dyn_ = new Reloc_section(); | |
274 | layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL, | |
275 | elfcpp::SHF_ALLOC, this->rel_dyn_); | |
276 | } | |
277 | return this->rel_dyn_; | |
278 | } | |
279 | ||
a3ad94ed ILT |
280 | // A class to handle the PLT data. |
281 | ||
282 | class Output_data_plt_i386 : public Output_section_data | |
283 | { | |
284 | public: | |
285 | typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section; | |
286 | ||
7e1edb90 | 287 | Output_data_plt_i386(Layout*, Output_data_space*); |
a3ad94ed ILT |
288 | |
289 | // Add an entry to the PLT. | |
290 | void | |
291 | add_entry(Symbol* gsym); | |
292 | ||
16649710 ILT |
293 | // Return the .rel.plt section data. |
294 | const Reloc_section* | |
295 | rel_plt() const | |
296 | { return this->rel_; } | |
297 | ||
298 | protected: | |
299 | void | |
300 | do_adjust_output_section(Output_section* os); | |
301 | ||
a3ad94ed ILT |
302 | private: |
303 | // The size of an entry in the PLT. | |
304 | static const int plt_entry_size = 16; | |
305 | ||
306 | // The first entry in the PLT for an executable. | |
307 | static unsigned char exec_first_plt_entry[plt_entry_size]; | |
308 | ||
309 | // The first entry in the PLT for a shared object. | |
310 | static unsigned char dyn_first_plt_entry[plt_entry_size]; | |
311 | ||
312 | // Other entries in the PLT for an executable. | |
313 | static unsigned char exec_plt_entry[plt_entry_size]; | |
314 | ||
315 | // Other entries in the PLT for a shared object. | |
316 | static unsigned char dyn_plt_entry[plt_entry_size]; | |
317 | ||
318 | // Set the final size. | |
319 | void | |
320 | do_set_address(uint64_t, off_t) | |
321 | { this->set_data_size((this->count_ + 1) * plt_entry_size); } | |
322 | ||
323 | // Write out the PLT data. | |
324 | void | |
325 | do_write(Output_file*); | |
326 | ||
327 | // The reloc section. | |
328 | Reloc_section* rel_; | |
329 | // The .got.plt section. | |
330 | Output_data_space* got_plt_; | |
331 | // The number of PLT entries. | |
332 | unsigned int count_; | |
a3ad94ed ILT |
333 | }; |
334 | ||
335 | // Create the PLT section. The ordinary .got section is an argument, | |
336 | // since we need to refer to the start. We also create our own .got | |
337 | // section just for PLT entries. | |
338 | ||
339 | Output_data_plt_i386::Output_data_plt_i386(Layout* layout, | |
7e1edb90 ILT |
340 | Output_data_space* got_plt) |
341 | : Output_section_data(4), got_plt_(got_plt) | |
a3ad94ed ILT |
342 | { |
343 | this->rel_ = new Reloc_section(); | |
344 | layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL, | |
345 | elfcpp::SHF_ALLOC, this->rel_); | |
346 | } | |
347 | ||
16649710 ILT |
348 | // For some reason |
349 | ||
350 | void | |
351 | Output_data_plt_i386::do_adjust_output_section(Output_section* os) | |
352 | { | |
353 | // UnixWare sets the entsize of .plt to 4, and so does the old GNU | |
354 | // linker, and so do we. | |
355 | os->set_entsize(4); | |
356 | } | |
357 | ||
a3ad94ed ILT |
358 | // Add an entry to the PLT. |
359 | ||
360 | void | |
361 | Output_data_plt_i386::add_entry(Symbol* gsym) | |
362 | { | |
363 | gold_assert(!gsym->has_plt_offset()); | |
364 | ||
365 | // Note that when setting the PLT offset we skip the initial | |
366 | // reserved PLT entry. | |
367 | gsym->set_plt_offset((this->count_ + 1) * plt_entry_size); | |
368 | ||
369 | ++this->count_; | |
370 | ||
371 | off_t got_offset = this->got_plt_->data_size(); | |
372 | ||
373 | // Every PLT entry needs a GOT entry which points back to the PLT | |
374 | // entry (this will be changed by the dynamic linker, normally | |
375 | // lazily when the function is called). | |
376 | this->got_plt_->set_space_size(got_offset + 4); | |
377 | ||
378 | // Every PLT entry needs a reloc. | |
16649710 | 379 | gsym->set_needs_dynsym_entry(); |
a3ad94ed ILT |
380 | this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_, |
381 | got_offset); | |
382 | ||
383 | // Note that we don't need to save the symbol. The contents of the | |
384 | // PLT are independent of which symbols are used. The symbols only | |
385 | // appear in the relocations. | |
386 | } | |
387 | ||
388 | // The first entry in the PLT for an executable. | |
389 | ||
390 | unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] = | |
391 | { | |
392 | 0xff, 0x35, // pushl contents of memory address | |
393 | 0, 0, 0, 0, // replaced with address of .got + 4 | |
394 | 0xff, 0x25, // jmp indirect | |
395 | 0, 0, 0, 0, // replaced with address of .got + 8 | |
396 | 0, 0, 0, 0 // unused | |
397 | }; | |
398 | ||
399 | // The first entry in the PLT for a shared object. | |
400 | ||
401 | unsigned char Output_data_plt_i386::dyn_first_plt_entry[plt_entry_size] = | |
402 | { | |
403 | 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx) | |
404 | 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx) | |
405 | 0, 0, 0, 0 // unused | |
406 | }; | |
407 | ||
408 | // Subsequent entries in the PLT for an executable. | |
409 | ||
410 | unsigned char Output_data_plt_i386::exec_plt_entry[plt_entry_size] = | |
411 | { | |
412 | 0xff, 0x25, // jmp indirect | |
413 | 0, 0, 0, 0, // replaced with address of symbol in .got | |
414 | 0x68, // pushl immediate | |
415 | 0, 0, 0, 0, // replaced with offset into relocation table | |
416 | 0xe9, // jmp relative | |
417 | 0, 0, 0, 0 // replaced with offset to start of .plt | |
418 | }; | |
419 | ||
420 | // Subsequent entries in the PLT for a shared object. | |
421 | ||
422 | unsigned char Output_data_plt_i386::dyn_plt_entry[plt_entry_size] = | |
423 | { | |
424 | 0xff, 0xa3, // jmp *offset(%ebx) | |
425 | 0, 0, 0, 0, // replaced with offset of symbol in .got | |
426 | 0x68, // pushl immediate | |
427 | 0, 0, 0, 0, // replaced with offset into relocation table | |
428 | 0xe9, // jmp relative | |
429 | 0, 0, 0, 0 // replaced with offset to start of .plt | |
430 | }; | |
431 | ||
432 | // Write out the PLT. This uses the hand-coded instructions above, | |
433 | // and adjusts them as needed. This is all specified by the i386 ELF | |
434 | // Processor Supplement. | |
435 | ||
436 | void | |
437 | Output_data_plt_i386::do_write(Output_file* of) | |
438 | { | |
439 | const off_t offset = this->offset(); | |
440 | const off_t oview_size = this->data_size(); | |
441 | unsigned char* const oview = of->get_output_view(offset, oview_size); | |
442 | ||
443 | const off_t got_file_offset = this->got_plt_->offset(); | |
444 | const off_t got_size = this->got_plt_->data_size(); | |
445 | unsigned char* const got_view = of->get_output_view(got_file_offset, | |
446 | got_size); | |
447 | ||
448 | unsigned char* pov = oview; | |
449 | ||
450 | elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address(); | |
451 | elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address(); | |
452 | ||
7e1edb90 | 453 | if (parameters->output_is_shared()) |
a3ad94ed ILT |
454 | memcpy(pov, dyn_first_plt_entry, plt_entry_size); |
455 | else | |
456 | { | |
457 | memcpy(pov, exec_first_plt_entry, plt_entry_size); | |
458 | elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4); | |
459 | elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8); | |
460 | } | |
461 | pov += plt_entry_size; | |
462 | ||
463 | unsigned char* got_pov = got_view; | |
464 | ||
465 | memset(got_pov, 0, 12); | |
466 | got_pov += 12; | |
467 | ||
468 | const int rel_size = elfcpp::Elf_sizes<32>::rel_size; | |
469 | ||
470 | unsigned int plt_offset = plt_entry_size; | |
471 | unsigned int plt_rel_offset = 0; | |
472 | unsigned int got_offset = 12; | |
473 | const unsigned int count = this->count_; | |
474 | for (unsigned int i = 0; | |
475 | i < count; | |
476 | ++i, | |
477 | pov += plt_entry_size, | |
478 | got_pov += 4, | |
479 | plt_offset += plt_entry_size, | |
480 | plt_rel_offset += rel_size, | |
481 | got_offset += 4) | |
482 | { | |
483 | // Set and adjust the PLT entry itself. | |
484 | ||
7e1edb90 | 485 | if (parameters->output_is_shared()) |
a3ad94ed ILT |
486 | { |
487 | memcpy(pov, dyn_plt_entry, plt_entry_size); | |
488 | elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset); | |
489 | } | |
490 | else | |
491 | { | |
492 | memcpy(pov, exec_plt_entry, plt_entry_size); | |
493 | elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, | |
494 | (got_address | |
495 | + got_offset)); | |
496 | } | |
497 | ||
498 | elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset); | |
499 | elfcpp::Swap<32, false>::writeval(pov + 12, | |
500 | - (plt_offset + plt_entry_size)); | |
501 | ||
502 | // Set the entry in the GOT. | |
503 | elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6); | |
504 | } | |
505 | ||
506 | gold_assert(pov - oview == oview_size); | |
507 | gold_assert(got_pov - got_view == got_size); | |
508 | ||
509 | of->write_output_view(offset, oview_size, oview); | |
510 | of->write_output_view(got_file_offset, got_size, got_view); | |
511 | } | |
512 | ||
513 | // Create a PLT entry for a global symbol. | |
514 | ||
515 | void | |
7e1edb90 | 516 | Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym) |
a3ad94ed ILT |
517 | { |
518 | if (gsym->has_plt_offset()) | |
519 | return; | |
520 | ||
521 | if (this->plt_ == NULL) | |
522 | { | |
523 | // Create the GOT sections first. | |
7e1edb90 | 524 | this->got_section(symtab, layout); |
a3ad94ed | 525 | |
7e1edb90 | 526 | this->plt_ = new Output_data_plt_i386(layout, this->got_plt_); |
16649710 ILT |
527 | layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS, |
528 | (elfcpp::SHF_ALLOC | |
529 | | elfcpp::SHF_EXECINSTR), | |
530 | this->plt_); | |
a3ad94ed ILT |
531 | } |
532 | ||
533 | this->plt_->add_entry(gsym); | |
534 | } | |
535 | ||
536 | // Handle a relocation against a non-function symbol defined in a | |
537 | // dynamic object. The traditional way to handle this is to generate | |
538 | // a COPY relocation to copy the variable at runtime from the shared | |
539 | // object into the executable's data segment. However, this is | |
540 | // undesirable in general, as if the size of the object changes in the | |
541 | // dynamic object, the executable will no longer work correctly. If | |
542 | // this relocation is in a writable section, then we can create a | |
543 | // dynamic reloc and the dynamic linker will resolve it to the correct | |
544 | // address at runtime. However, we do not want do that if the | |
545 | // relocation is in a read-only section, as it would prevent the | |
546 | // readonly segment from being shared. And if we have to eventually | |
547 | // generate a COPY reloc, then any dynamic relocations will be | |
548 | // useless. So this means that if this is a writable section, we need | |
549 | // to save the relocation until we see whether we have to create a | |
550 | // COPY relocation for this symbol for any other relocation. | |
551 | ||
552 | void | |
553 | Target_i386::copy_reloc(const General_options* options, | |
5a6f7e2d ILT |
554 | Symbol_table* symtab, |
555 | Layout* layout, | |
a3ad94ed ILT |
556 | Sized_relobj<32, false>* object, |
557 | unsigned int data_shndx, Symbol* gsym, | |
5a6f7e2d | 558 | const elfcpp::Rel<32, false>& rel) |
a3ad94ed | 559 | { |
5a6f7e2d ILT |
560 | Sized_symbol<32>* ssym; |
561 | ssym = symtab->get_sized_symbol SELECT_SIZE_NAME(32) (gsym | |
562 | SELECT_SIZE(32)); | |
563 | ||
564 | if (!Copy_relocs<32, false>::need_copy_reloc(options, object, | |
565 | data_shndx, ssym)) | |
a3ad94ed ILT |
566 | { |
567 | // So far we do not need a COPY reloc. Save this relocation. | |
5a6f7e2d ILT |
568 | // If it turns out that we never need a COPY reloc for this |
569 | // symbol, then we will emit the relocation. | |
570 | if (this->copy_relocs_ == NULL) | |
571 | this->copy_relocs_ = new Copy_relocs<32, false>(); | |
572 | this->copy_relocs_->save(ssym, object, data_shndx, rel); | |
a3ad94ed | 573 | } |
5a6f7e2d ILT |
574 | else |
575 | { | |
576 | // Allocate space for this symbol in the .bss section. | |
577 | ||
578 | elfcpp::Elf_types<32>::Elf_WXword symsize = ssym->symsize(); | |
579 | ||
580 | // There is no defined way to determine the required alignment | |
581 | // of the symbol. We pick the alignment based on the size. We | |
582 | // set an arbitrary maximum of 256. | |
583 | unsigned int align; | |
584 | for (align = 1; align < 512; align <<= 1) | |
585 | if ((symsize & align) != 0) | |
586 | break; | |
a3ad94ed | 587 | |
5a6f7e2d ILT |
588 | if (this->dynbss_ == NULL) |
589 | { | |
590 | this->dynbss_ = new Output_data_space(align); | |
591 | layout->add_output_section_data(".bss", | |
592 | elfcpp::SHT_NOBITS, | |
593 | (elfcpp::SHF_ALLOC | |
594 | | elfcpp::SHF_WRITE), | |
595 | this->dynbss_); | |
596 | } | |
597 | ||
598 | Output_data_space* dynbss = this->dynbss_; | |
599 | ||
600 | if (align > dynbss->addralign()) | |
601 | dynbss->set_space_alignment(align); | |
602 | ||
603 | off_t dynbss_size = dynbss->data_size(); | |
604 | dynbss_size = align_address(dynbss_size, align); | |
605 | off_t offset = dynbss_size; | |
606 | dynbss->set_space_size(dynbss_size + symsize); | |
607 | ||
608 | // Define the symbol in the .dynbss section. | |
14b31740 ILT |
609 | symtab->define_in_output_data(this, ssym->name(), ssym->version(), |
610 | dynbss, offset, symsize, ssym->type(), | |
611 | ssym->binding(), ssym->visibility(), | |
612 | ssym->nonvis(), false, false); | |
5a6f7e2d ILT |
613 | |
614 | // Add the COPY reloc. | |
16649710 | 615 | ssym->set_needs_dynsym_entry(); |
5a6f7e2d ILT |
616 | Reloc_section* rel_dyn = this->rel_dyn_section(layout); |
617 | rel_dyn->add_global(ssym, elfcpp::R_386_COPY, dynbss, offset); | |
618 | } | |
a3ad94ed ILT |
619 | } |
620 | ||
92e059d8 | 621 | // Optimize the TLS relocation type based on what we know about the |
a3ad94ed ILT |
622 | // symbol. IS_FINAL is true if the final address of this symbol is |
623 | // known at link time. | |
92e059d8 ILT |
624 | |
625 | unsigned int | |
7e1edb90 | 626 | Target_i386::optimize_tls_reloc(bool is_final, int r_type) |
92e059d8 ILT |
627 | { |
628 | // If we are generating a shared library, then we can't do anything | |
629 | // in the linker. | |
7e1edb90 | 630 | if (parameters->output_is_shared()) |
92e059d8 ILT |
631 | return r_type; |
632 | ||
633 | switch (r_type) | |
634 | { | |
635 | case elfcpp::R_386_TLS_GD: | |
636 | case elfcpp::R_386_TLS_GOTDESC: | |
637 | case elfcpp::R_386_TLS_DESC_CALL: | |
638 | // These are Global-Dynamic which permits fully general TLS | |
639 | // access. Since we know that we are generating an executable, | |
640 | // we can convert this to Initial-Exec. If we also know that | |
641 | // this is a local symbol, we can further switch to Local-Exec. | |
a3ad94ed | 642 | if (is_final) |
92e059d8 ILT |
643 | return elfcpp::R_386_TLS_LE_32; |
644 | return elfcpp::R_386_TLS_IE_32; | |
645 | ||
646 | case elfcpp::R_386_TLS_LDM: | |
647 | // This is Local-Dynamic, which refers to a local symbol in the | |
648 | // dynamic TLS block. Since we know that we generating an | |
649 | // executable, we can switch to Local-Exec. | |
650 | return elfcpp::R_386_TLS_LE_32; | |
651 | ||
652 | case elfcpp::R_386_TLS_LDO_32: | |
653 | // Another type of Local-Dynamic relocation. | |
654 | return elfcpp::R_386_TLS_LE; | |
655 | ||
656 | case elfcpp::R_386_TLS_IE: | |
657 | case elfcpp::R_386_TLS_GOTIE: | |
658 | case elfcpp::R_386_TLS_IE_32: | |
659 | // These are Initial-Exec relocs which get the thread offset | |
660 | // from the GOT. If we know that we are linking against the | |
661 | // local symbol, we can switch to Local-Exec, which links the | |
662 | // thread offset into the instruction. | |
a3ad94ed | 663 | if (is_final) |
92e059d8 ILT |
664 | return elfcpp::R_386_TLS_LE_32; |
665 | return r_type; | |
8462ae85 | 666 | |
92e059d8 ILT |
667 | case elfcpp::R_386_TLS_LE: |
668 | case elfcpp::R_386_TLS_LE_32: | |
669 | // When we already have Local-Exec, there is nothing further we | |
670 | // can do. | |
671 | return r_type; | |
672 | ||
673 | default: | |
a3ad94ed | 674 | gold_unreachable(); |
92e059d8 ILT |
675 | } |
676 | } | |
677 | ||
678 | // Scan a relocation for a local symbol. | |
679 | ||
680 | inline void | |
7e1edb90 | 681 | Target_i386::Scan::local(const General_options&, |
ead1e424 ILT |
682 | Symbol_table* symtab, |
683 | Layout* layout, | |
684 | Target_i386* target, | |
f6ce93d6 | 685 | Sized_relobj<32, false>* object, |
a3ad94ed ILT |
686 | unsigned int, |
687 | const elfcpp::Rel<32, false>&, | |
688 | unsigned int r_type, | |
92e059d8 ILT |
689 | const elfcpp::Sym<32, false>&) |
690 | { | |
691 | switch (r_type) | |
692 | { | |
693 | case elfcpp::R_386_NONE: | |
694 | case elfcpp::R_386_GNU_VTINHERIT: | |
695 | case elfcpp::R_386_GNU_VTENTRY: | |
696 | break; | |
697 | ||
698 | case elfcpp::R_386_32: | |
699 | case elfcpp::R_386_16: | |
700 | case elfcpp::R_386_8: | |
701 | // FIXME: If we are generating a shared object we need to copy | |
702 | // this relocation into the object. | |
7e1edb90 | 703 | gold_assert(!parameters->output_is_shared()); |
92e059d8 ILT |
704 | break; |
705 | ||
706 | case elfcpp::R_386_PC32: | |
707 | case elfcpp::R_386_PC16: | |
708 | case elfcpp::R_386_PC8: | |
709 | break; | |
710 | ||
ead1e424 ILT |
711 | case elfcpp::R_386_GOTOFF: |
712 | case elfcpp::R_386_GOTPC: | |
713 | // We need a GOT section. | |
7e1edb90 | 714 | target->got_section(symtab, layout); |
ead1e424 ILT |
715 | break; |
716 | ||
92e059d8 ILT |
717 | case elfcpp::R_386_COPY: |
718 | case elfcpp::R_386_GLOB_DAT: | |
719 | case elfcpp::R_386_JUMP_SLOT: | |
720 | case elfcpp::R_386_RELATIVE: | |
721 | case elfcpp::R_386_TLS_TPOFF: | |
722 | case elfcpp::R_386_TLS_DTPMOD32: | |
723 | case elfcpp::R_386_TLS_DTPOFF32: | |
724 | case elfcpp::R_386_TLS_TPOFF32: | |
725 | case elfcpp::R_386_TLS_DESC: | |
726 | fprintf(stderr, _("%s: %s: unexpected reloc %u in object file\n"), | |
727 | program_name, object->name().c_str(), r_type); | |
728 | gold_exit(false); | |
729 | break; | |
730 | ||
731 | case elfcpp::R_386_TLS_IE: | |
732 | case elfcpp::R_386_TLS_GOTIE: | |
733 | case elfcpp::R_386_TLS_LE: | |
734 | case elfcpp::R_386_TLS_GD: | |
735 | case elfcpp::R_386_TLS_LDM: | |
736 | case elfcpp::R_386_TLS_LDO_32: | |
737 | case elfcpp::R_386_TLS_IE_32: | |
738 | case elfcpp::R_386_TLS_LE_32: | |
739 | case elfcpp::R_386_TLS_GOTDESC: | |
740 | case elfcpp::R_386_TLS_DESC_CALL: | |
7e1edb90 ILT |
741 | { |
742 | bool output_is_executable = parameters->output_is_executable(); | |
743 | r_type = Target_i386::optimize_tls_reloc(output_is_executable, | |
744 | r_type); | |
745 | switch (r_type) | |
746 | { | |
747 | case elfcpp::R_386_TLS_LE: | |
748 | case elfcpp::R_386_TLS_LE_32: | |
749 | // FIXME: If generating a shared object, we need to copy | |
750 | // this relocation into the object. | |
751 | gold_assert(output_is_executable); | |
752 | break; | |
92e059d8 | 753 | |
7e1edb90 ILT |
754 | case elfcpp::R_386_TLS_IE: |
755 | case elfcpp::R_386_TLS_GOTIE: | |
756 | case elfcpp::R_386_TLS_GD: | |
757 | case elfcpp::R_386_TLS_LDM: | |
758 | case elfcpp::R_386_TLS_LDO_32: | |
759 | case elfcpp::R_386_TLS_IE_32: | |
760 | case elfcpp::R_386_TLS_GOTDESC: | |
761 | case elfcpp::R_386_TLS_DESC_CALL: | |
762 | fprintf(stderr, | |
763 | _("%s: %s: unsupported reloc %u against local symbol\n"), | |
764 | program_name, object->name().c_str(), r_type); | |
765 | break; | |
766 | } | |
767 | } | |
92e059d8 ILT |
768 | break; |
769 | ||
770 | case elfcpp::R_386_GOT32: | |
771 | case elfcpp::R_386_PLT32: | |
92e059d8 ILT |
772 | case elfcpp::R_386_32PLT: |
773 | case elfcpp::R_386_TLS_GD_32: | |
774 | case elfcpp::R_386_TLS_GD_PUSH: | |
775 | case elfcpp::R_386_TLS_GD_CALL: | |
776 | case elfcpp::R_386_TLS_GD_POP: | |
777 | case elfcpp::R_386_TLS_LDM_32: | |
778 | case elfcpp::R_386_TLS_LDM_PUSH: | |
779 | case elfcpp::R_386_TLS_LDM_CALL: | |
780 | case elfcpp::R_386_TLS_LDM_POP: | |
781 | case elfcpp::R_386_USED_BY_INTEL_200: | |
782 | default: | |
783 | fprintf(stderr, _("%s: %s: unsupported reloc %u against local symbol\n"), | |
784 | program_name, object->name().c_str(), r_type); | |
785 | break; | |
786 | } | |
787 | } | |
788 | ||
789 | // Scan a relocation for a global symbol. | |
790 | ||
791 | inline void | |
792 | Target_i386::Scan::global(const General_options& options, | |
ead1e424 ILT |
793 | Symbol_table* symtab, |
794 | Layout* layout, | |
795 | Target_i386* target, | |
f6ce93d6 | 796 | Sized_relobj<32, false>* object, |
a3ad94ed ILT |
797 | unsigned int data_shndx, |
798 | const elfcpp::Rel<32, false>& reloc, | |
799 | unsigned int r_type, | |
92e059d8 ILT |
800 | Symbol* gsym) |
801 | { | |
802 | switch (r_type) | |
803 | { | |
804 | case elfcpp::R_386_NONE: | |
805 | case elfcpp::R_386_GNU_VTINHERIT: | |
8462ae85 | 806 | case elfcpp::R_386_GNU_VTENTRY: |
92e059d8 ILT |
807 | break; |
808 | ||
809 | case elfcpp::R_386_32: | |
810 | case elfcpp::R_386_PC32: | |
811 | case elfcpp::R_386_16: | |
812 | case elfcpp::R_386_PC16: | |
813 | case elfcpp::R_386_8: | |
814 | case elfcpp::R_386_PC8: | |
815 | // FIXME: If we are generating a shared object we may need to | |
816 | // copy this relocation into the object. If this symbol is | |
817 | // defined in a shared object, we may need to copy this | |
818 | // relocation in order to avoid a COPY relocation. | |
7e1edb90 | 819 | gold_assert(!parameters->output_is_shared()); |
a3ad94ed | 820 | |
14b31740 | 821 | if (gsym->is_from_dynobj()) |
a3ad94ed ILT |
822 | { |
823 | // This symbol is defined in a dynamic object. If it is a | |
824 | // function, we make a PLT entry. Otherwise we need to | |
825 | // either generate a COPY reloc or copy this reloc. | |
826 | if (gsym->type() == elfcpp::STT_FUNC) | |
7e1edb90 | 827 | target->make_plt_entry(symtab, layout, gsym); |
a3ad94ed | 828 | else |
5a6f7e2d ILT |
829 | target->copy_reloc(&options, symtab, layout, object, data_shndx, |
830 | gsym, reloc); | |
a3ad94ed ILT |
831 | } |
832 | ||
92e059d8 ILT |
833 | break; |
834 | ||
ead1e424 | 835 | case elfcpp::R_386_GOT32: |
8462ae85 ILT |
836 | { |
837 | // The symbol requires a GOT entry. | |
7e1edb90 | 838 | Output_data_got<32, false>* got = target->got_section(symtab, layout); |
8462ae85 ILT |
839 | if (got->add_global(gsym)) |
840 | { | |
841 | // If this symbol is not fully resolved, we need to add a | |
842 | // dynamic relocation for it. | |
7e1edb90 | 843 | if (!gsym->final_value_is_known()) |
8462ae85 ILT |
844 | { |
845 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); | |
846 | rel_dyn->add_global(gsym, elfcpp::R_386_GLOB_DAT, got, | |
847 | gsym->got_offset()); | |
848 | } | |
849 | } | |
850 | } | |
ead1e424 ILT |
851 | break; |
852 | ||
853 | case elfcpp::R_386_PLT32: | |
a3ad94ed ILT |
854 | // If the symbol is fully resolved, this is just a PC32 reloc. |
855 | // Otherwise we need a PLT entry. | |
7e1edb90 | 856 | if (gsym->final_value_is_known()) |
ead1e424 | 857 | break; |
7e1edb90 | 858 | target->make_plt_entry(symtab, layout, gsym); |
ead1e424 ILT |
859 | break; |
860 | ||
861 | case elfcpp::R_386_GOTOFF: | |
862 | case elfcpp::R_386_GOTPC: | |
863 | // We need a GOT section. | |
7e1edb90 | 864 | target->got_section(symtab, layout); |
ead1e424 ILT |
865 | break; |
866 | ||
92e059d8 ILT |
867 | case elfcpp::R_386_COPY: |
868 | case elfcpp::R_386_GLOB_DAT: | |
869 | case elfcpp::R_386_JUMP_SLOT: | |
870 | case elfcpp::R_386_RELATIVE: | |
871 | case elfcpp::R_386_TLS_TPOFF: | |
872 | case elfcpp::R_386_TLS_DTPMOD32: | |
873 | case elfcpp::R_386_TLS_DTPOFF32: | |
874 | case elfcpp::R_386_TLS_TPOFF32: | |
875 | case elfcpp::R_386_TLS_DESC: | |
876 | fprintf(stderr, _("%s: %s: unexpected reloc %u in object file\n"), | |
877 | program_name, object->name().c_str(), r_type); | |
878 | gold_exit(false); | |
879 | break; | |
880 | ||
881 | case elfcpp::R_386_TLS_IE: | |
882 | case elfcpp::R_386_TLS_GOTIE: | |
883 | case elfcpp::R_386_TLS_LE: | |
884 | case elfcpp::R_386_TLS_GD: | |
885 | case elfcpp::R_386_TLS_LDM: | |
886 | case elfcpp::R_386_TLS_LDO_32: | |
887 | case elfcpp::R_386_TLS_IE_32: | |
888 | case elfcpp::R_386_TLS_LE_32: | |
889 | case elfcpp::R_386_TLS_GOTDESC: | |
890 | case elfcpp::R_386_TLS_DESC_CALL: | |
a3ad94ed | 891 | { |
7e1edb90 ILT |
892 | const bool is_final = gsym->final_value_is_known(); |
893 | r_type = Target_i386::optimize_tls_reloc(is_final, r_type); | |
a3ad94ed ILT |
894 | switch (r_type) |
895 | { | |
896 | case elfcpp::R_386_TLS_LE: | |
897 | case elfcpp::R_386_TLS_LE_32: | |
898 | // FIXME: If generating a shared object, we need to copy | |
899 | // this relocation into the object. | |
7e1edb90 | 900 | gold_assert(!parameters->output_is_shared()); |
a3ad94ed ILT |
901 | break; |
902 | ||
903 | case elfcpp::R_386_TLS_IE: | |
904 | case elfcpp::R_386_TLS_GOTIE: | |
905 | case elfcpp::R_386_TLS_GD: | |
906 | case elfcpp::R_386_TLS_LDM: | |
907 | case elfcpp::R_386_TLS_LDO_32: | |
908 | case elfcpp::R_386_TLS_IE_32: | |
909 | case elfcpp::R_386_TLS_GOTDESC: | |
910 | case elfcpp::R_386_TLS_DESC_CALL: | |
911 | fprintf(stderr, | |
912 | _("%s: %s: unsupported reloc %u " | |
913 | "against global symbol %s\n"), | |
914 | program_name, object->name().c_str(), r_type, | |
915 | gsym->name()); | |
916 | break; | |
917 | } | |
918 | } | |
92e059d8 ILT |
919 | break; |
920 | ||
92e059d8 ILT |
921 | case elfcpp::R_386_32PLT: |
922 | case elfcpp::R_386_TLS_GD_32: | |
923 | case elfcpp::R_386_TLS_GD_PUSH: | |
924 | case elfcpp::R_386_TLS_GD_CALL: | |
925 | case elfcpp::R_386_TLS_GD_POP: | |
926 | case elfcpp::R_386_TLS_LDM_32: | |
927 | case elfcpp::R_386_TLS_LDM_PUSH: | |
928 | case elfcpp::R_386_TLS_LDM_CALL: | |
929 | case elfcpp::R_386_TLS_LDM_POP: | |
930 | case elfcpp::R_386_USED_BY_INTEL_200: | |
931 | default: | |
932 | fprintf(stderr, | |
933 | _("%s: %s: unsupported reloc %u against global symbol %s\n"), | |
934 | program_name, object->name().c_str(), r_type, gsym->name()); | |
935 | break; | |
936 | } | |
937 | } | |
938 | ||
939 | // Scan relocations for a section. | |
940 | ||
941 | void | |
942 | Target_i386::scan_relocs(const General_options& options, | |
943 | Symbol_table* symtab, | |
ead1e424 | 944 | Layout* layout, |
f6ce93d6 | 945 | Sized_relobj<32, false>* object, |
a3ad94ed | 946 | unsigned int data_shndx, |
92e059d8 ILT |
947 | unsigned int sh_type, |
948 | const unsigned char* prelocs, | |
949 | size_t reloc_count, | |
950 | size_t local_symbol_count, | |
951 | const unsigned char* plocal_symbols, | |
952 | Symbol** global_symbols) | |
953 | { | |
954 | if (sh_type == elfcpp::SHT_RELA) | |
955 | { | |
956 | fprintf(stderr, _("%s: %s: unsupported RELA reloc section\n"), | |
957 | program_name, object->name().c_str()); | |
958 | gold_exit(false); | |
959 | } | |
960 | ||
ead1e424 ILT |
961 | gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL, |
962 | Target_i386::Scan>( | |
92e059d8 ILT |
963 | options, |
964 | symtab, | |
ead1e424 ILT |
965 | layout, |
966 | this, | |
92e059d8 | 967 | object, |
a3ad94ed | 968 | data_shndx, |
92e059d8 ILT |
969 | prelocs, |
970 | reloc_count, | |
971 | local_symbol_count, | |
972 | plocal_symbols, | |
973 | global_symbols); | |
974 | } | |
975 | ||
16649710 | 976 | // Finalize the sections. |
5a6f7e2d ILT |
977 | |
978 | void | |
7e1edb90 | 979 | Target_i386::do_finalize_sections(Layout* layout) |
5a6f7e2d | 980 | { |
16649710 ILT |
981 | // Fill in some more dynamic tags. |
982 | Output_data_dynamic* const odyn = layout->dynamic_data(); | |
983 | if (odyn != NULL) | |
984 | { | |
985 | if (this->got_plt_ != NULL) | |
986 | odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_); | |
987 | ||
988 | if (this->plt_ != NULL) | |
989 | { | |
990 | const Output_data* od = this->plt_->rel_plt(); | |
991 | odyn->add_section_size(elfcpp::DT_PLTRELSZ, od); | |
992 | odyn->add_section_address(elfcpp::DT_JMPREL, od); | |
993 | odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_REL); | |
994 | } | |
995 | ||
996 | if (this->rel_dyn_ != NULL) | |
997 | { | |
998 | const Output_data* od = this->rel_dyn_; | |
999 | odyn->add_section_address(elfcpp::DT_REL, od); | |
1000 | odyn->add_section_size(elfcpp::DT_RELSZ, od); | |
1001 | odyn->add_constant(elfcpp::DT_RELENT, | |
1002 | elfcpp::Elf_sizes<32>::rel_size); | |
1003 | } | |
1004 | ||
7e1edb90 | 1005 | if (!parameters->output_is_shared()) |
16649710 ILT |
1006 | { |
1007 | // The value of the DT_DEBUG tag is filled in by the dynamic | |
1008 | // linker at run time, and used by the debugger. | |
1009 | odyn->add_constant(elfcpp::DT_DEBUG, 0); | |
1010 | } | |
1011 | } | |
1012 | ||
1013 | // Emit any relocs we saved in an attempt to avoid generating COPY | |
1014 | // relocs. | |
5a6f7e2d ILT |
1015 | if (this->copy_relocs_ == NULL) |
1016 | return; | |
1017 | if (this->copy_relocs_->any_to_emit()) | |
1018 | { | |
1019 | Reloc_section* rel_dyn = this->rel_dyn_section(layout); | |
1020 | this->copy_relocs_->emit(rel_dyn); | |
1021 | } | |
1022 | delete this->copy_relocs_; | |
1023 | this->copy_relocs_ = NULL; | |
1024 | } | |
1025 | ||
61ba1cf9 ILT |
1026 | // Perform a relocation. |
1027 | ||
ead1e424 | 1028 | inline bool |
92e059d8 | 1029 | Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo, |
ead1e424 | 1030 | Target_i386* target, |
92e059d8 ILT |
1031 | size_t relnum, |
1032 | const elfcpp::Rel<32, false>& rel, | |
1033 | unsigned int r_type, | |
c06b7b0b | 1034 | const Sized_symbol<32>* gsym, |
b8e6aad9 | 1035 | const Symbol_value<32>* psymval, |
92e059d8 ILT |
1036 | unsigned char* view, |
1037 | elfcpp::Elf_types<32>::Elf_Addr address, | |
1038 | off_t view_size) | |
61ba1cf9 | 1039 | { |
ead1e424 ILT |
1040 | if (this->skip_call_tls_get_addr_) |
1041 | { | |
1042 | if (r_type != elfcpp::R_386_PLT32 | |
1043 | || gsym == NULL | |
1044 | || strcmp(gsym->name(), "___tls_get_addr") != 0) | |
1045 | { | |
1046 | fprintf(stderr, _("%s: %s: missing expected TLS relocation\n"), | |
1047 | program_name, | |
1048 | relinfo->location(relnum, rel.get_r_offset()).c_str()); | |
1049 | gold_exit(false); | |
1050 | } | |
1051 | ||
1052 | this->skip_call_tls_get_addr_ = false; | |
1053 | ||
1054 | return false; | |
1055 | } | |
1056 | ||
a3ad94ed | 1057 | // Pick the value to use for symbols defined in shared objects. |
b8e6aad9 | 1058 | Symbol_value<32> symval; |
8462ae85 | 1059 | if (gsym != NULL && gsym->is_from_dynobj() && gsym->has_plt_offset()) |
a3ad94ed | 1060 | { |
b8e6aad9 ILT |
1061 | symval.set_output_value(target->plt_section()->address() |
1062 | + gsym->plt_offset()); | |
1063 | psymval = &symval; | |
a3ad94ed ILT |
1064 | } |
1065 | ||
b8e6aad9 ILT |
1066 | const Sized_relobj<32, false>* object = relinfo->object; |
1067 | ||
61ba1cf9 ILT |
1068 | switch (r_type) |
1069 | { | |
1070 | case elfcpp::R_386_NONE: | |
92e059d8 ILT |
1071 | case elfcpp::R_386_GNU_VTINHERIT: |
1072 | case elfcpp::R_386_GNU_VTENTRY: | |
61ba1cf9 ILT |
1073 | break; |
1074 | ||
1075 | case elfcpp::R_386_32: | |
b8e6aad9 | 1076 | Relocate_functions<32, false>::rel32(view, object, psymval); |
61ba1cf9 ILT |
1077 | break; |
1078 | ||
1079 | case elfcpp::R_386_PC32: | |
b8e6aad9 | 1080 | Relocate_functions<32, false>::pcrel32(view, object, psymval, address); |
92e059d8 ILT |
1081 | break; |
1082 | ||
1083 | case elfcpp::R_386_16: | |
b8e6aad9 | 1084 | Relocate_functions<32, false>::rel16(view, object, psymval); |
92e059d8 ILT |
1085 | break; |
1086 | ||
1087 | case elfcpp::R_386_PC16: | |
b8e6aad9 | 1088 | Relocate_functions<32, false>::pcrel16(view, object, psymval, address); |
61ba1cf9 ILT |
1089 | break; |
1090 | ||
92e059d8 | 1091 | case elfcpp::R_386_8: |
b8e6aad9 | 1092 | Relocate_functions<32, false>::rel8(view, object, psymval); |
92e059d8 ILT |
1093 | break; |
1094 | ||
1095 | case elfcpp::R_386_PC8: | |
b8e6aad9 | 1096 | Relocate_functions<32, false>::pcrel8(view, object, psymval, address); |
92e059d8 ILT |
1097 | break; |
1098 | ||
ead1e424 | 1099 | case elfcpp::R_386_PLT32: |
a3ad94ed | 1100 | gold_assert(gsym->has_plt_offset() |
7e1edb90 | 1101 | || gsym->final_value_is_known()); |
b8e6aad9 | 1102 | Relocate_functions<32, false>::pcrel32(view, object, psymval, address); |
ead1e424 ILT |
1103 | break; |
1104 | ||
1105 | case elfcpp::R_386_GOT32: | |
1106 | // Local GOT offsets not yet supported. | |
a3ad94ed ILT |
1107 | gold_assert(gsym); |
1108 | gold_assert(gsym->has_got_offset()); | |
b8e6aad9 | 1109 | Relocate_functions<32, false>::rel32(view, gsym->got_offset()); |
ead1e424 ILT |
1110 | break; |
1111 | ||
1112 | case elfcpp::R_386_GOTOFF: | |
b8e6aad9 ILT |
1113 | { |
1114 | elfcpp::Elf_types<32>::Elf_Addr value; | |
1115 | value = (psymval->value(object, 0) | |
7e1edb90 | 1116 | - target->got_section(NULL, NULL)->address()); |
b8e6aad9 ILT |
1117 | Relocate_functions<32, false>::rel32(view, value); |
1118 | } | |
ead1e424 ILT |
1119 | break; |
1120 | ||
1121 | case elfcpp::R_386_GOTPC: | |
b8e6aad9 ILT |
1122 | { |
1123 | elfcpp::Elf_types<32>::Elf_Addr value; | |
7e1edb90 | 1124 | value = target->got_section(NULL, NULL)->address(); |
b8e6aad9 ILT |
1125 | Relocate_functions<32, false>::pcrel32(view, value, address); |
1126 | } | |
ead1e424 ILT |
1127 | break; |
1128 | ||
92e059d8 ILT |
1129 | case elfcpp::R_386_COPY: |
1130 | case elfcpp::R_386_GLOB_DAT: | |
1131 | case elfcpp::R_386_JUMP_SLOT: | |
1132 | case elfcpp::R_386_RELATIVE: | |
1133 | case elfcpp::R_386_TLS_TPOFF: | |
1134 | case elfcpp::R_386_TLS_DTPMOD32: | |
1135 | case elfcpp::R_386_TLS_DTPOFF32: | |
1136 | case elfcpp::R_386_TLS_TPOFF32: | |
1137 | case elfcpp::R_386_TLS_DESC: | |
1138 | fprintf(stderr, _("%s: %s: unexpected reloc %u in object file\n"), | |
1139 | program_name, | |
1140 | relinfo->location(relnum, rel.get_r_offset()).c_str(), | |
1141 | r_type); | |
1142 | gold_exit(false); | |
1143 | break; | |
1144 | ||
1145 | case elfcpp::R_386_TLS_IE: | |
1146 | case elfcpp::R_386_TLS_GOTIE: | |
1147 | case elfcpp::R_386_TLS_LE: | |
1148 | case elfcpp::R_386_TLS_GD: | |
1149 | case elfcpp::R_386_TLS_LDM: | |
1150 | case elfcpp::R_386_TLS_LDO_32: | |
1151 | case elfcpp::R_386_TLS_IE_32: | |
1152 | case elfcpp::R_386_TLS_LE_32: | |
1153 | case elfcpp::R_386_TLS_GOTDESC: | |
1154 | case elfcpp::R_386_TLS_DESC_CALL: | |
b8e6aad9 | 1155 | this->relocate_tls(relinfo, relnum, rel, r_type, gsym, psymval, view, |
ead1e424 | 1156 | address, view_size); |
92e059d8 ILT |
1157 | break; |
1158 | ||
92e059d8 ILT |
1159 | case elfcpp::R_386_32PLT: |
1160 | case elfcpp::R_386_TLS_GD_32: | |
1161 | case elfcpp::R_386_TLS_GD_PUSH: | |
1162 | case elfcpp::R_386_TLS_GD_CALL: | |
1163 | case elfcpp::R_386_TLS_GD_POP: | |
1164 | case elfcpp::R_386_TLS_LDM_32: | |
1165 | case elfcpp::R_386_TLS_LDM_PUSH: | |
1166 | case elfcpp::R_386_TLS_LDM_CALL: | |
1167 | case elfcpp::R_386_TLS_LDM_POP: | |
1168 | case elfcpp::R_386_USED_BY_INTEL_200: | |
61ba1cf9 ILT |
1169 | default: |
1170 | fprintf(stderr, _("%s: %s: unsupported reloc %u\n"), | |
92e059d8 ILT |
1171 | program_name, |
1172 | relinfo->location(relnum, rel.get_r_offset()).c_str(), | |
1173 | r_type); | |
61ba1cf9 | 1174 | // gold_exit(false); |
92e059d8 ILT |
1175 | break; |
1176 | } | |
ead1e424 ILT |
1177 | |
1178 | return true; | |
92e059d8 ILT |
1179 | } |
1180 | ||
1181 | // Perform a TLS relocation. | |
1182 | ||
1183 | inline void | |
1184 | Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo, | |
1185 | size_t relnum, | |
1186 | const elfcpp::Rel<32, false>& rel, | |
1187 | unsigned int r_type, | |
c06b7b0b | 1188 | const Sized_symbol<32>* gsym, |
b8e6aad9 | 1189 | const Symbol_value<32>* psymval, |
92e059d8 ILT |
1190 | unsigned char* view, |
1191 | elfcpp::Elf_types<32>::Elf_Addr, | |
1192 | off_t view_size) | |
1193 | { | |
1194 | Output_segment* tls_segment = relinfo->layout->tls_segment(); | |
1195 | if (tls_segment == NULL) | |
1196 | { | |
1197 | fprintf(stderr, _("%s: %s: TLS reloc but no TLS segment\n"), | |
1198 | program_name, | |
1199 | relinfo->location(relnum, rel.get_r_offset()).c_str()); | |
1200 | gold_exit(false); | |
1201 | } | |
1202 | ||
b8e6aad9 ILT |
1203 | elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(relinfo->object, 0); |
1204 | ||
a3ad94ed | 1205 | const bool is_final = (gsym == NULL |
7e1edb90 ILT |
1206 | ? !parameters->output_is_shared() |
1207 | : gsym->final_value_is_known()); | |
92e059d8 | 1208 | const unsigned int opt_r_type = |
7e1edb90 | 1209 | Target_i386::optimize_tls_reloc(is_final, r_type); |
92e059d8 ILT |
1210 | switch (r_type) |
1211 | { | |
1212 | case elfcpp::R_386_TLS_LE_32: | |
1213 | value = tls_segment->vaddr() + tls_segment->memsz() - value; | |
1214 | Relocate_functions<32, false>::rel32(view, value); | |
1215 | break; | |
1216 | ||
1217 | case elfcpp::R_386_TLS_LE: | |
1218 | value = value - (tls_segment->vaddr() + tls_segment->memsz()); | |
1219 | Relocate_functions<32, false>::rel32(view, value); | |
1220 | break; | |
1221 | ||
1222 | case elfcpp::R_386_TLS_IE: | |
1223 | case elfcpp::R_386_TLS_GOTIE: | |
1224 | case elfcpp::R_386_TLS_IE_32: | |
1225 | if (opt_r_type == elfcpp::R_386_TLS_LE_32) | |
1226 | { | |
1227 | Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment, | |
1228 | rel, r_type, value, view, | |
1229 | view_size); | |
1230 | break; | |
1231 | } | |
1232 | fprintf(stderr, _("%s: %s: unsupported reloc type %u\n"), | |
1233 | program_name, | |
1234 | relinfo->location(relnum, rel.get_r_offset()).c_str(), | |
1235 | r_type); | |
1236 | // gold_exit(false); | |
1237 | break; | |
1238 | ||
1239 | case elfcpp::R_386_TLS_GD: | |
ead1e424 ILT |
1240 | if (opt_r_type == elfcpp::R_386_TLS_LE_32) |
1241 | { | |
1242 | this->tls_gd_to_le(relinfo, relnum, tls_segment, | |
1243 | rel, r_type, value, view, | |
1244 | view_size); | |
1245 | break; | |
1246 | } | |
1247 | fprintf(stderr, _("%s: %s: unsupported reloc %u\n"), | |
1248 | program_name, | |
1249 | relinfo->location(relnum, rel.get_r_offset()).c_str(), | |
1250 | r_type); | |
1251 | // gold_exit(false); | |
1252 | break; | |
1253 | ||
92e059d8 ILT |
1254 | case elfcpp::R_386_TLS_LDM: |
1255 | case elfcpp::R_386_TLS_LDO_32: | |
1256 | case elfcpp::R_386_TLS_GOTDESC: | |
1257 | case elfcpp::R_386_TLS_DESC_CALL: | |
1258 | fprintf(stderr, _("%s: %s: unsupported reloc %u\n"), | |
1259 | program_name, | |
1260 | relinfo->location(relnum, rel.get_r_offset()).c_str(), | |
1261 | r_type); | |
1262 | // gold_exit(false); | |
1263 | break; | |
1264 | } | |
1265 | } | |
1266 | ||
1267 | // Do a relocation in which we convert a TLS Initial-Exec to a | |
1268 | // Local-Exec. | |
1269 | ||
1270 | inline void | |
1271 | Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo, | |
1272 | size_t relnum, | |
1273 | Output_segment* tls_segment, | |
1274 | const elfcpp::Rel<32, false>& rel, | |
1275 | unsigned int r_type, | |
1276 | elfcpp::Elf_types<32>::Elf_Addr value, | |
1277 | unsigned char* view, | |
1278 | off_t view_size) | |
1279 | { | |
1280 | // We have to actually change the instructions, which means that we | |
1281 | // need to examine the opcodes to figure out which instruction we | |
1282 | // are looking at. | |
1283 | if (r_type == elfcpp::R_386_TLS_IE) | |
1284 | { | |
1285 | // movl %gs:XX,%eax ==> movl $YY,%eax | |
1286 | // movl %gs:XX,%reg ==> movl $YY,%reg | |
1287 | // addl %gs:XX,%reg ==> addl $YY,%reg | |
1288 | Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, -1); | |
1289 | Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, 4); | |
1290 | ||
1291 | unsigned char op1 = view[-1]; | |
1292 | if (op1 == 0xa1) | |
1293 | { | |
1294 | // movl XX,%eax ==> movl $YY,%eax | |
1295 | view[-1] = 0xb8; | |
1296 | } | |
1297 | else | |
1298 | { | |
1299 | Target_i386::Relocate::check_range(relinfo, relnum, rel, | |
1300 | view_size, -2); | |
1301 | ||
1302 | unsigned char op2 = view[-2]; | |
1303 | if (op2 == 0x8b) | |
1304 | { | |
1305 | // movl XX,%reg ==> movl $YY,%reg | |
1306 | Target_i386::Relocate::check_tls(relinfo, relnum, rel, | |
1307 | (op1 & 0xc7) == 0x05); | |
1308 | view[-2] = 0xc7; | |
1309 | view[-1] = 0xc0 | ((op1 >> 3) & 7); | |
1310 | } | |
1311 | else if (op2 == 0x03) | |
1312 | { | |
1313 | // addl XX,%reg ==> addl $YY,%reg | |
1314 | Target_i386::Relocate::check_tls(relinfo, relnum, rel, | |
1315 | (op1 & 0xc7) == 0x05); | |
1316 | view[-2] = 0x81; | |
1317 | view[-1] = 0xc0 | ((op1 >> 3) & 7); | |
1318 | } | |
1319 | else | |
1320 | Target_i386::Relocate::check_tls(relinfo, relnum, rel, 0); | |
1321 | } | |
1322 | } | |
1323 | else | |
1324 | { | |
1325 | // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2 | |
1326 | // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2 | |
1327 | // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2 | |
1328 | Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, -2); | |
1329 | Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, 4); | |
1330 | ||
1331 | unsigned char op1 = view[-1]; | |
1332 | unsigned char op2 = view[-2]; | |
1333 | Target_i386::Relocate::check_tls(relinfo, relnum, rel, | |
1334 | (op1 & 0xc0) == 0x80 && (op1 & 7) != 4); | |
1335 | if (op2 == 0x8b) | |
1336 | { | |
1337 | // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2 | |
1338 | view[-2] = 0xc7; | |
1339 | view[-1] = 0xc0 | ((op1 >> 3) & 7); | |
1340 | } | |
1341 | else if (op2 == 0x2b) | |
1342 | { | |
1343 | // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2 | |
1344 | view[-2] = 0x81; | |
1345 | view[-1] = 0xe8 | ((op1 >> 3) & 7); | |
1346 | } | |
1347 | else if (op2 == 0x03) | |
1348 | { | |
1349 | // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2 | |
1350 | view[-2] = 0x81; | |
1351 | view[-1] = 0xc0 | ((op1 >> 3) & 7); | |
1352 | } | |
1353 | else | |
1354 | Target_i386::Relocate::check_tls(relinfo, relnum, rel, 0); | |
1355 | } | |
1356 | ||
ead1e424 ILT |
1357 | value = tls_segment->vaddr() + tls_segment->memsz() - value; |
1358 | if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE) | |
1359 | value = - value; | |
92e059d8 ILT |
1360 | |
1361 | Relocate_functions<32, false>::rel32(view, value); | |
1362 | } | |
1363 | ||
ead1e424 ILT |
1364 | // Do a relocation in which we convert a TLS Global-Dynamic to a |
1365 | // Local-Exec. | |
1366 | ||
1367 | inline void | |
1368 | Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo, | |
1369 | size_t relnum, | |
1370 | Output_segment* tls_segment, | |
1371 | const elfcpp::Rel<32, false>& rel, | |
1372 | unsigned int, | |
1373 | elfcpp::Elf_types<32>::Elf_Addr value, | |
1374 | unsigned char* view, | |
1375 | off_t view_size) | |
1376 | { | |
1377 | // leal foo(,%reg,1),%eax; call ___tls_get_addr | |
1378 | // ==> movl %gs,0,%eax; subl $foo@tpoff,%eax | |
1379 | // leal foo(%reg),%eax; call ___tls_get_addr | |
1380 | // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax | |
1381 | ||
1382 | Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, -2); | |
1383 | Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, 9); | |
1384 | ||
1385 | unsigned char op1 = view[-1]; | |
1386 | unsigned char op2 = view[-2]; | |
1387 | ||
1388 | Target_i386::Relocate::check_tls(relinfo, relnum, rel, | |
1389 | op2 == 0x8d || op2 == 0x04); | |
1390 | Target_i386::Relocate::check_tls(relinfo, relnum, rel, | |
1391 | view[4] == 0xe8); | |
1392 | ||
1393 | int roff = 5; | |
1394 | ||
1395 | if (op2 == 0x04) | |
1396 | { | |
1397 | Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, -3); | |
1398 | Target_i386::Relocate::check_tls(relinfo, relnum, rel, | |
1399 | view[-3] == 0x8d); | |
1400 | Target_i386::Relocate::check_tls(relinfo, relnum, rel, | |
1401 | ((op1 & 0xc7) == 0x05 | |
1402 | && op1 != (4 << 3))); | |
1403 | memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12); | |
1404 | } | |
1405 | else | |
1406 | { | |
1407 | Target_i386::Relocate::check_tls(relinfo, relnum, rel, | |
1408 | (op1 & 0xf8) == 0x80 && (op1 & 7) != 4); | |
1409 | if (rel.get_r_offset() + 9 < view_size && view[9] == 0x90) | |
1410 | { | |
1411 | // There is a trailing nop. Use the size byte subl. | |
1412 | memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12); | |
1413 | roff = 6; | |
1414 | } | |
1415 | else | |
1416 | { | |
1417 | // Use the five byte subl. | |
1418 | memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11); | |
1419 | } | |
1420 | } | |
1421 | ||
1422 | value = tls_segment->vaddr() + tls_segment->memsz() - value; | |
1423 | Relocate_functions<32, false>::rel32(view + roff, value); | |
1424 | ||
1425 | // The next reloc should be a PLT32 reloc against __tls_get_addr. | |
1426 | // We can skip it. | |
1427 | this->skip_call_tls_get_addr_ = true; | |
1428 | } | |
1429 | ||
92e059d8 ILT |
1430 | // Check the range for a TLS relocation. |
1431 | ||
1432 | inline void | |
1433 | Target_i386::Relocate::check_range(const Relocate_info<32, false>* relinfo, | |
1434 | size_t relnum, | |
1435 | const elfcpp::Rel<32, false>& rel, | |
1436 | off_t view_size, off_t off) | |
1437 | { | |
1438 | off_t offset = rel.get_r_offset() + off; | |
1439 | if (offset < 0 || offset > view_size) | |
1440 | { | |
1441 | fprintf(stderr, _("%s: %s: TLS relocation out of range\n"), | |
1442 | program_name, | |
1443 | relinfo->location(relnum, rel.get_r_offset()).c_str()); | |
1444 | gold_exit(false); | |
1445 | } | |
1446 | } | |
1447 | ||
1448 | // Check the validity of a TLS relocation. This is like assert. | |
1449 | ||
1450 | inline void | |
1451 | Target_i386::Relocate::check_tls(const Relocate_info<32, false>* relinfo, | |
1452 | size_t relnum, | |
1453 | const elfcpp::Rel<32, false>& rel, | |
1454 | bool valid) | |
1455 | { | |
1456 | if (!valid) | |
1457 | { | |
1458 | fprintf(stderr, | |
1459 | _("%s: %s: TLS relocation against invalid instruction\n"), | |
1460 | program_name, | |
1461 | relinfo->location(relnum, rel.get_r_offset()).c_str()); | |
1462 | gold_exit(false); | |
61ba1cf9 ILT |
1463 | } |
1464 | } | |
1465 | ||
1466 | // Relocate section data. | |
1467 | ||
1468 | void | |
92e059d8 | 1469 | Target_i386::relocate_section(const Relocate_info<32, false>* relinfo, |
61ba1cf9 ILT |
1470 | unsigned int sh_type, |
1471 | const unsigned char* prelocs, | |
1472 | size_t reloc_count, | |
61ba1cf9 ILT |
1473 | unsigned char* view, |
1474 | elfcpp::Elf_types<32>::Elf_Addr address, | |
1475 | off_t view_size) | |
1476 | { | |
a3ad94ed | 1477 | gold_assert(sh_type == elfcpp::SHT_REL); |
61ba1cf9 | 1478 | |
ead1e424 ILT |
1479 | gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL, |
1480 | Target_i386::Relocate>( | |
92e059d8 | 1481 | relinfo, |
ead1e424 | 1482 | this, |
61ba1cf9 ILT |
1483 | prelocs, |
1484 | reloc_count, | |
61ba1cf9 ILT |
1485 | view, |
1486 | address, | |
1487 | view_size); | |
1488 | } | |
1489 | ||
c51e6221 ILT |
1490 | // Return a string used to fill a code section with nops to take up |
1491 | // the specified length. | |
1492 | ||
1493 | std::string | |
1494 | Target_i386::do_code_fill(off_t length) | |
1495 | { | |
1496 | if (length >= 16) | |
1497 | { | |
1498 | // Build a jmp instruction to skip over the bytes. | |
1499 | unsigned char jmp[5]; | |
1500 | jmp[0] = 0xe9; | |
1501 | elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5); | |
1502 | return (std::string(reinterpret_cast<char*>(&jmp[0]), 5) | |
1503 | + std::string(length - 5, '\0')); | |
1504 | } | |
1505 | ||
1506 | // Nop sequences of various lengths. | |
1507 | const char nop1[1] = { 0x90 }; // nop | |
1508 | const char nop2[2] = { 0x66, 0x90 }; // xchg %ax %ax | |
1509 | const char nop3[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi | |
1510 | const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi | |
1511 | const char nop5[5] = { 0x90, 0x8d, 0x74, 0x26, // nop | |
1512 | 0x00 }; // leal 0(%esi,1),%esi | |
1513 | const char nop6[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi | |
1514 | 0x00, 0x00 }; | |
1515 | const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi | |
1516 | 0x00, 0x00, 0x00 }; | |
1517 | const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop | |
1518 | 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi | |
1519 | const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi | |
1520 | 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi | |
1521 | 0x00 }; | |
1522 | const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi | |
1523 | 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi | |
1524 | 0x00, 0x00 }; | |
1525 | const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi | |
1526 | 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi | |
1527 | 0x00, 0x00, 0x00 }; | |
1528 | const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi | |
1529 | 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi | |
1530 | 0x00, 0x00, 0x00, 0x00 }; | |
1531 | const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi | |
1532 | 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi | |
1533 | 0x27, 0x00, 0x00, 0x00, | |
1534 | 0x00 }; | |
1535 | const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi | |
1536 | 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi | |
1537 | 0xbc, 0x27, 0x00, 0x00, | |
1538 | 0x00, 0x00 }; | |
1539 | const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15 | |
1540 | 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,... | |
1541 | 0x90, 0x90, 0x90, 0x90, | |
1542 | 0x90, 0x90, 0x90 }; | |
1543 | ||
1544 | const char* nops[16] = { | |
1545 | NULL, | |
1546 | nop1, nop2, nop3, nop4, nop5, nop6, nop7, | |
1547 | nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15 | |
1548 | }; | |
1549 | ||
1550 | return std::string(nops[length], length); | |
1551 | } | |
1552 | ||
14bfc3f5 ILT |
1553 | // The selector for i386 object files. |
1554 | ||
1555 | class Target_selector_i386 : public Target_selector | |
1556 | { | |
1557 | public: | |
1558 | Target_selector_i386() | |
1559 | : Target_selector(elfcpp::EM_386, 32, false) | |
1560 | { } | |
1561 | ||
1562 | Target* | |
ead1e424 ILT |
1563 | recognize(int machine, int osabi, int abiversion); |
1564 | ||
1565 | private: | |
1566 | Target_i386* target_; | |
14bfc3f5 ILT |
1567 | }; |
1568 | ||
1569 | // Recognize an i386 object file when we already know that the machine | |
1570 | // number is EM_386. | |
1571 | ||
1572 | Target* | |
ead1e424 | 1573 | Target_selector_i386::recognize(int, int, int) |
14bfc3f5 | 1574 | { |
ead1e424 ILT |
1575 | if (this->target_ == NULL) |
1576 | this->target_ = new Target_i386(); | |
1577 | return this->target_; | |
14bfc3f5 ILT |
1578 | } |
1579 | ||
1580 | Target_selector_i386 target_selector_i386; | |
1581 | ||
1582 | } // End anonymous namespace. |