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14bfc3f5 ILT |
1 | // i386.cc -- i386 target support for gold. |
2 | ||
6cb15b7f ILT |
3 | // Copyright 2006, 2007 Free Software Foundation, Inc. |
4 | // Written by Ian Lance Taylor <iant@google.com>. | |
5 | ||
6 | // This file is part of gold. | |
7 | ||
8 | // This program is free software; you can redistribute it and/or modify | |
9 | // it under the terms of the GNU General Public License as published by | |
10 | // the Free Software Foundation; either version 3 of the License, or | |
11 | // (at your option) any later version. | |
12 | ||
13 | // This program is distributed in the hope that it will be useful, | |
14 | // but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | // GNU General Public License for more details. | |
17 | ||
18 | // You should have received a copy of the GNU General Public License | |
19 | // along with this program; if not, write to the Free Software | |
20 | // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, | |
21 | // MA 02110-1301, USA. | |
22 | ||
14bfc3f5 | 23 | #include "gold.h" |
ead1e424 ILT |
24 | |
25 | #include <cstring> | |
26 | ||
14bfc3f5 | 27 | #include "elfcpp.h" |
7e1edb90 | 28 | #include "parameters.h" |
92e059d8 | 29 | #include "reloc.h" |
61ba1cf9 ILT |
30 | #include "i386.h" |
31 | #include "object.h" | |
ead1e424 | 32 | #include "symtab.h" |
92e059d8 ILT |
33 | #include "layout.h" |
34 | #include "output.h" | |
14bfc3f5 | 35 | #include "target.h" |
61ba1cf9 | 36 | #include "target-reloc.h" |
14bfc3f5 | 37 | #include "target-select.h" |
af6359d5 | 38 | #include "tls.h" |
14bfc3f5 ILT |
39 | |
40 | namespace | |
41 | { | |
42 | ||
43 | using namespace gold; | |
44 | ||
a3ad94ed ILT |
45 | class Output_data_plt_i386; |
46 | ||
14bfc3f5 | 47 | // The i386 target class. |
e041f13d ILT |
48 | // TLS info comes from |
49 | // http://people.redhat.com/drepper/tls.pdf | |
50 | // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt | |
14bfc3f5 ILT |
51 | |
52 | class Target_i386 : public Sized_target<32, false> | |
53 | { | |
54 | public: | |
5a6f7e2d ILT |
55 | typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section; |
56 | ||
14bfc3f5 | 57 | Target_i386() |
ead1e424 | 58 | : Sized_target<32, false>(&i386_info), |
5a6f7e2d ILT |
59 | got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL), |
60 | copy_relocs_(NULL), dynbss_(NULL) | |
14bfc3f5 | 61 | { } |
75f65a3e | 62 | |
92e059d8 | 63 | // Scan the relocations to look for symbol adjustments. |
61ba1cf9 | 64 | void |
92e059d8 ILT |
65 | scan_relocs(const General_options& options, |
66 | Symbol_table* symtab, | |
ead1e424 | 67 | Layout* layout, |
f6ce93d6 | 68 | Sized_relobj<32, false>* object, |
a3ad94ed | 69 | unsigned int data_shndx, |
92e059d8 ILT |
70 | unsigned int sh_type, |
71 | const unsigned char* prelocs, | |
72 | size_t reloc_count, | |
73 | size_t local_symbol_count, | |
74 | const unsigned char* plocal_symbols, | |
75 | Symbol** global_symbols); | |
61ba1cf9 | 76 | |
5a6f7e2d ILT |
77 | // Finalize the sections. |
78 | void | |
7e1edb90 | 79 | do_finalize_sections(Layout*); |
5a6f7e2d | 80 | |
ab5c9e90 ILT |
81 | // Return the value to use for a dynamic which requires special |
82 | // treatment. | |
83 | uint64_t | |
84 | do_dynsym_value(const Symbol*) const; | |
85 | ||
92e059d8 ILT |
86 | // Relocate a section. |
87 | void | |
88 | relocate_section(const Relocate_info<32, false>*, | |
89 | unsigned int sh_type, | |
90 | const unsigned char* prelocs, | |
91 | size_t reloc_count, | |
92 | unsigned char* view, | |
93 | elfcpp::Elf_types<32>::Elf_Addr view_address, | |
94 | off_t view_size); | |
95 | ||
c51e6221 ILT |
96 | // Return a string used to fill a code section with nops. |
97 | std::string | |
98 | do_code_fill(off_t length); | |
99 | ||
92e059d8 ILT |
100 | private: |
101 | // The class which scans relocations. | |
102 | struct Scan | |
61ba1cf9 ILT |
103 | { |
104 | inline void | |
ead1e424 ILT |
105 | local(const General_options& options, Symbol_table* symtab, |
106 | Layout* layout, Target_i386* target, | |
f6ce93d6 | 107 | Sized_relobj<32, false>* object, |
a3ad94ed | 108 | unsigned int data_shndx, |
92e059d8 ILT |
109 | const elfcpp::Rel<32, false>& reloc, unsigned int r_type, |
110 | const elfcpp::Sym<32, false>& lsym); | |
61ba1cf9 | 111 | |
92e059d8 | 112 | inline void |
ead1e424 ILT |
113 | global(const General_options& options, Symbol_table* symtab, |
114 | Layout* layout, Target_i386* target, | |
f6ce93d6 | 115 | Sized_relobj<32, false>* object, |
a3ad94ed | 116 | unsigned int data_shndx, |
92e059d8 ILT |
117 | const elfcpp::Rel<32, false>& reloc, unsigned int r_type, |
118 | Symbol* gsym); | |
af6359d5 ILT |
119 | |
120 | static void | |
121 | unsupported_reloc_local(Sized_relobj<32, false>*, unsigned int r_type); | |
122 | ||
123 | static void | |
124 | unsupported_reloc_global(Sized_relobj<32, false>*, unsigned int r_type, | |
125 | Symbol*); | |
61ba1cf9 ILT |
126 | }; |
127 | ||
92e059d8 ILT |
128 | // The class which implements relocation. |
129 | class Relocate | |
130 | { | |
131 | public: | |
ead1e424 | 132 | Relocate() |
46cf9fa2 ILT |
133 | : skip_call_tls_get_addr_(false), |
134 | local_dynamic_type_(LOCAL_DYNAMIC_NONE) | |
ead1e424 ILT |
135 | { } |
136 | ||
137 | ~Relocate() | |
138 | { | |
139 | if (this->skip_call_tls_get_addr_) | |
140 | { | |
141 | // FIXME: This needs to specify the location somehow. | |
75f2446e | 142 | gold_error(_("missing expected TLS relocation")); |
ead1e424 ILT |
143 | } |
144 | } | |
145 | ||
146 | // Do a relocation. Return false if the caller should not issue | |
147 | // any warnings about this relocation. | |
148 | inline bool | |
149 | relocate(const Relocate_info<32, false>*, Target_i386*, size_t relnum, | |
92e059d8 | 150 | const elfcpp::Rel<32, false>&, |
c06b7b0b | 151 | unsigned int r_type, const Sized_symbol<32>*, |
b8e6aad9 | 152 | const Symbol_value<32>*, |
92e059d8 ILT |
153 | unsigned char*, elfcpp::Elf_types<32>::Elf_Addr, |
154 | off_t); | |
155 | ||
156 | private: | |
157 | // Do a TLS relocation. | |
ead1e424 | 158 | inline void |
92e059d8 ILT |
159 | relocate_tls(const Relocate_info<32, false>*, size_t relnum, |
160 | const elfcpp::Rel<32, false>&, | |
c06b7b0b | 161 | unsigned int r_type, const Sized_symbol<32>*, |
b8e6aad9 | 162 | const Symbol_value<32>*, |
92e059d8 ILT |
163 | unsigned char*, elfcpp::Elf_types<32>::Elf_Addr, off_t); |
164 | ||
56622147 ILT |
165 | // Do a TLS General-Dynamic to Local-Exec transition. |
166 | inline void | |
167 | tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum, | |
92e059d8 ILT |
168 | Output_segment* tls_segment, |
169 | const elfcpp::Rel<32, false>&, unsigned int r_type, | |
170 | elfcpp::Elf_types<32>::Elf_Addr value, | |
171 | unsigned char* view, | |
172 | off_t view_size); | |
173 | ||
56622147 | 174 | // Do a TLS Local-Dynamic to Local-Exec transition. |
ead1e424 | 175 | inline void |
56622147 | 176 | tls_ld_to_le(const Relocate_info<32, false>*, size_t relnum, |
ead1e424 ILT |
177 | Output_segment* tls_segment, |
178 | const elfcpp::Rel<32, false>&, unsigned int r_type, | |
179 | elfcpp::Elf_types<32>::Elf_Addr value, | |
180 | unsigned char* view, | |
181 | off_t view_size); | |
182 | ||
56622147 ILT |
183 | // Do a TLS Initial-Exec to Local-Exec transition. |
184 | static inline void | |
185 | tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum, | |
46cf9fa2 ILT |
186 | Output_segment* tls_segment, |
187 | const elfcpp::Rel<32, false>&, unsigned int r_type, | |
188 | elfcpp::Elf_types<32>::Elf_Addr value, | |
189 | unsigned char* view, | |
190 | off_t view_size); | |
191 | ||
46cf9fa2 ILT |
192 | // We need to keep track of which type of local dynamic relocation |
193 | // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly. | |
194 | enum Local_dynamic_type | |
195 | { | |
196 | LOCAL_DYNAMIC_NONE, | |
197 | LOCAL_DYNAMIC_SUN, | |
198 | LOCAL_DYNAMIC_GNU | |
199 | }; | |
200 | ||
ead1e424 ILT |
201 | // This is set if we should skip the next reloc, which should be a |
202 | // PLT32 reloc against ___tls_get_addr. | |
203 | bool skip_call_tls_get_addr_; | |
46cf9fa2 ILT |
204 | // The type of local dynamic relocation we have seen in the section |
205 | // being relocated, if any. | |
206 | Local_dynamic_type local_dynamic_type_; | |
92e059d8 ILT |
207 | }; |
208 | ||
209 | // Adjust TLS relocation type based on the options and whether this | |
210 | // is a local symbol. | |
af6359d5 | 211 | static tls::Tls_optimization |
7e1edb90 | 212 | optimize_tls_reloc(bool is_final, int r_type); |
92e059d8 | 213 | |
ead1e424 | 214 | // Get the GOT section, creating it if necessary. |
dbe717ef | 215 | Output_data_got<32, false>* |
7e1edb90 | 216 | got_section(Symbol_table*, Layout*); |
a3ad94ed ILT |
217 | |
218 | // Create a PLT entry for a global symbol. | |
219 | void | |
7e1edb90 | 220 | make_plt_entry(Symbol_table*, Layout*, Symbol*); |
a3ad94ed ILT |
221 | |
222 | // Get the PLT section. | |
7bb3655e | 223 | const Output_data_plt_i386* |
a3ad94ed ILT |
224 | plt_section() const |
225 | { | |
226 | gold_assert(this->plt_ != NULL); | |
227 | return this->plt_; | |
228 | } | |
229 | ||
5a6f7e2d ILT |
230 | // Get the dynamic reloc section, creating it if necessary. |
231 | Reloc_section* | |
232 | rel_dyn_section(Layout*); | |
233 | ||
a3ad94ed ILT |
234 | // Copy a relocation against a global symbol. |
235 | void | |
5a6f7e2d ILT |
236 | copy_reloc(const General_options*, Symbol_table*, Layout*, |
237 | Sized_relobj<32, false>*, unsigned int, | |
a3ad94ed | 238 | Symbol*, const elfcpp::Rel<32, false>&); |
ead1e424 | 239 | |
92e059d8 ILT |
240 | // Information about this specific target which we pass to the |
241 | // general Target structure. | |
75f65a3e | 242 | static const Target::Target_info i386_info; |
ead1e424 ILT |
243 | |
244 | // The GOT section. | |
dbe717ef | 245 | Output_data_got<32, false>* got_; |
a3ad94ed ILT |
246 | // The PLT section. |
247 | Output_data_plt_i386* plt_; | |
248 | // The GOT PLT section. | |
249 | Output_data_space* got_plt_; | |
5a6f7e2d ILT |
250 | // The dynamic reloc section. |
251 | Reloc_section* rel_dyn_; | |
252 | // Relocs saved to avoid a COPY reloc. | |
253 | Copy_relocs<32, false>* copy_relocs_; | |
254 | // Space for variables copied with a COPY reloc. | |
255 | Output_data_space* dynbss_; | |
75f65a3e ILT |
256 | }; |
257 | ||
258 | const Target::Target_info Target_i386::i386_info = | |
259 | { | |
61ba1cf9 ILT |
260 | 32, // size |
261 | false, // is_big_endian | |
262 | elfcpp::EM_386, // machine_code | |
263 | false, // has_make_symbol | |
dbe717ef | 264 | false, // has_resolve |
c51e6221 | 265 | true, // has_code_fill |
35cdfc9a | 266 | true, // is_default_stack_executable |
dbe717ef | 267 | "/usr/lib/libc.so.1", // dynamic_linker |
0c5e9c22 | 268 | 0x08048000, // default_text_segment_address |
61ba1cf9 ILT |
269 | 0x1000, // abi_pagesize |
270 | 0x1000 // common_pagesize | |
14bfc3f5 ILT |
271 | }; |
272 | ||
ead1e424 ILT |
273 | // Get the GOT section, creating it if necessary. |
274 | ||
dbe717ef | 275 | Output_data_got<32, false>* |
7e1edb90 | 276 | Target_i386::got_section(Symbol_table* symtab, Layout* layout) |
ead1e424 ILT |
277 | { |
278 | if (this->got_ == NULL) | |
279 | { | |
7e1edb90 | 280 | gold_assert(symtab != NULL && layout != NULL); |
a3ad94ed | 281 | |
7e1edb90 | 282 | this->got_ = new Output_data_got<32, false>(); |
ead1e424 | 283 | |
ead1e424 | 284 | layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS, |
16649710 ILT |
285 | elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE, |
286 | this->got_); | |
ead1e424 | 287 | |
a3ad94ed ILT |
288 | // The old GNU linker creates a .got.plt section. We just |
289 | // create another set of data in the .got section. Note that we | |
290 | // always create a PLT if we create a GOT, although the PLT | |
291 | // might be empty. | |
292 | this->got_plt_ = new Output_data_space(4); | |
293 | layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS, | |
16649710 ILT |
294 | elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE, |
295 | this->got_plt_); | |
a3ad94ed | 296 | |
ead1e424 | 297 | // The first three entries are reserved. |
a3ad94ed | 298 | this->got_plt_->set_space_size(3 * 4); |
ead1e424 | 299 | |
a3ad94ed | 300 | // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT. |
14b31740 | 301 | symtab->define_in_output_data(this, "_GLOBAL_OFFSET_TABLE_", NULL, |
a3ad94ed | 302 | this->got_plt_, |
ead1e424 | 303 | 0, 0, elfcpp::STT_OBJECT, |
16649710 | 304 | elfcpp::STB_LOCAL, |
ead1e424 ILT |
305 | elfcpp::STV_HIDDEN, 0, |
306 | false, false); | |
307 | } | |
a3ad94ed | 308 | |
ead1e424 ILT |
309 | return this->got_; |
310 | } | |
311 | ||
5a6f7e2d ILT |
312 | // Get the dynamic reloc section, creating it if necessary. |
313 | ||
314 | Target_i386::Reloc_section* | |
315 | Target_i386::rel_dyn_section(Layout* layout) | |
316 | { | |
317 | if (this->rel_dyn_ == NULL) | |
318 | { | |
319 | gold_assert(layout != NULL); | |
320 | this->rel_dyn_ = new Reloc_section(); | |
321 | layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL, | |
322 | elfcpp::SHF_ALLOC, this->rel_dyn_); | |
323 | } | |
324 | return this->rel_dyn_; | |
325 | } | |
326 | ||
a3ad94ed ILT |
327 | // A class to handle the PLT data. |
328 | ||
329 | class Output_data_plt_i386 : public Output_section_data | |
330 | { | |
331 | public: | |
332 | typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section; | |
333 | ||
7e1edb90 | 334 | Output_data_plt_i386(Layout*, Output_data_space*); |
a3ad94ed ILT |
335 | |
336 | // Add an entry to the PLT. | |
337 | void | |
338 | add_entry(Symbol* gsym); | |
339 | ||
16649710 ILT |
340 | // Return the .rel.plt section data. |
341 | const Reloc_section* | |
342 | rel_plt() const | |
343 | { return this->rel_; } | |
344 | ||
345 | protected: | |
346 | void | |
347 | do_adjust_output_section(Output_section* os); | |
348 | ||
a3ad94ed ILT |
349 | private: |
350 | // The size of an entry in the PLT. | |
351 | static const int plt_entry_size = 16; | |
352 | ||
353 | // The first entry in the PLT for an executable. | |
354 | static unsigned char exec_first_plt_entry[plt_entry_size]; | |
355 | ||
356 | // The first entry in the PLT for a shared object. | |
357 | static unsigned char dyn_first_plt_entry[plt_entry_size]; | |
358 | ||
359 | // Other entries in the PLT for an executable. | |
360 | static unsigned char exec_plt_entry[plt_entry_size]; | |
361 | ||
362 | // Other entries in the PLT for a shared object. | |
363 | static unsigned char dyn_plt_entry[plt_entry_size]; | |
364 | ||
365 | // Set the final size. | |
366 | void | |
367 | do_set_address(uint64_t, off_t) | |
368 | { this->set_data_size((this->count_ + 1) * plt_entry_size); } | |
369 | ||
370 | // Write out the PLT data. | |
371 | void | |
372 | do_write(Output_file*); | |
373 | ||
374 | // The reloc section. | |
375 | Reloc_section* rel_; | |
376 | // The .got.plt section. | |
377 | Output_data_space* got_plt_; | |
378 | // The number of PLT entries. | |
379 | unsigned int count_; | |
a3ad94ed ILT |
380 | }; |
381 | ||
382 | // Create the PLT section. The ordinary .got section is an argument, | |
383 | // since we need to refer to the start. We also create our own .got | |
384 | // section just for PLT entries. | |
385 | ||
386 | Output_data_plt_i386::Output_data_plt_i386(Layout* layout, | |
7e1edb90 | 387 | Output_data_space* got_plt) |
80576242 | 388 | : Output_section_data(4), got_plt_(got_plt), count_(0) |
a3ad94ed ILT |
389 | { |
390 | this->rel_ = new Reloc_section(); | |
391 | layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL, | |
392 | elfcpp::SHF_ALLOC, this->rel_); | |
393 | } | |
394 | ||
16649710 ILT |
395 | void |
396 | Output_data_plt_i386::do_adjust_output_section(Output_section* os) | |
397 | { | |
398 | // UnixWare sets the entsize of .plt to 4, and so does the old GNU | |
399 | // linker, and so do we. | |
400 | os->set_entsize(4); | |
401 | } | |
402 | ||
a3ad94ed ILT |
403 | // Add an entry to the PLT. |
404 | ||
405 | void | |
406 | Output_data_plt_i386::add_entry(Symbol* gsym) | |
407 | { | |
408 | gold_assert(!gsym->has_plt_offset()); | |
409 | ||
410 | // Note that when setting the PLT offset we skip the initial | |
411 | // reserved PLT entry. | |
412 | gsym->set_plt_offset((this->count_ + 1) * plt_entry_size); | |
413 | ||
414 | ++this->count_; | |
415 | ||
416 | off_t got_offset = this->got_plt_->data_size(); | |
417 | ||
418 | // Every PLT entry needs a GOT entry which points back to the PLT | |
419 | // entry (this will be changed by the dynamic linker, normally | |
420 | // lazily when the function is called). | |
421 | this->got_plt_->set_space_size(got_offset + 4); | |
422 | ||
423 | // Every PLT entry needs a reloc. | |
16649710 | 424 | gsym->set_needs_dynsym_entry(); |
a3ad94ed ILT |
425 | this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_, |
426 | got_offset); | |
427 | ||
428 | // Note that we don't need to save the symbol. The contents of the | |
429 | // PLT are independent of which symbols are used. The symbols only | |
430 | // appear in the relocations. | |
431 | } | |
432 | ||
433 | // The first entry in the PLT for an executable. | |
434 | ||
435 | unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] = | |
436 | { | |
437 | 0xff, 0x35, // pushl contents of memory address | |
438 | 0, 0, 0, 0, // replaced with address of .got + 4 | |
439 | 0xff, 0x25, // jmp indirect | |
440 | 0, 0, 0, 0, // replaced with address of .got + 8 | |
441 | 0, 0, 0, 0 // unused | |
442 | }; | |
443 | ||
444 | // The first entry in the PLT for a shared object. | |
445 | ||
446 | unsigned char Output_data_plt_i386::dyn_first_plt_entry[plt_entry_size] = | |
447 | { | |
448 | 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx) | |
449 | 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx) | |
450 | 0, 0, 0, 0 // unused | |
451 | }; | |
452 | ||
453 | // Subsequent entries in the PLT for an executable. | |
454 | ||
455 | unsigned char Output_data_plt_i386::exec_plt_entry[plt_entry_size] = | |
456 | { | |
457 | 0xff, 0x25, // jmp indirect | |
458 | 0, 0, 0, 0, // replaced with address of symbol in .got | |
459 | 0x68, // pushl immediate | |
460 | 0, 0, 0, 0, // replaced with offset into relocation table | |
461 | 0xe9, // jmp relative | |
462 | 0, 0, 0, 0 // replaced with offset to start of .plt | |
463 | }; | |
464 | ||
465 | // Subsequent entries in the PLT for a shared object. | |
466 | ||
467 | unsigned char Output_data_plt_i386::dyn_plt_entry[plt_entry_size] = | |
468 | { | |
469 | 0xff, 0xa3, // jmp *offset(%ebx) | |
470 | 0, 0, 0, 0, // replaced with offset of symbol in .got | |
471 | 0x68, // pushl immediate | |
472 | 0, 0, 0, 0, // replaced with offset into relocation table | |
473 | 0xe9, // jmp relative | |
474 | 0, 0, 0, 0 // replaced with offset to start of .plt | |
475 | }; | |
476 | ||
477 | // Write out the PLT. This uses the hand-coded instructions above, | |
478 | // and adjusts them as needed. This is all specified by the i386 ELF | |
479 | // Processor Supplement. | |
480 | ||
481 | void | |
482 | Output_data_plt_i386::do_write(Output_file* of) | |
483 | { | |
484 | const off_t offset = this->offset(); | |
485 | const off_t oview_size = this->data_size(); | |
486 | unsigned char* const oview = of->get_output_view(offset, oview_size); | |
487 | ||
488 | const off_t got_file_offset = this->got_plt_->offset(); | |
489 | const off_t got_size = this->got_plt_->data_size(); | |
490 | unsigned char* const got_view = of->get_output_view(got_file_offset, | |
491 | got_size); | |
492 | ||
493 | unsigned char* pov = oview; | |
494 | ||
495 | elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address(); | |
496 | elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address(); | |
497 | ||
7e1edb90 | 498 | if (parameters->output_is_shared()) |
a3ad94ed ILT |
499 | memcpy(pov, dyn_first_plt_entry, plt_entry_size); |
500 | else | |
501 | { | |
502 | memcpy(pov, exec_first_plt_entry, plt_entry_size); | |
503 | elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4); | |
504 | elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8); | |
505 | } | |
506 | pov += plt_entry_size; | |
507 | ||
508 | unsigned char* got_pov = got_view; | |
509 | ||
510 | memset(got_pov, 0, 12); | |
511 | got_pov += 12; | |
512 | ||
513 | const int rel_size = elfcpp::Elf_sizes<32>::rel_size; | |
514 | ||
515 | unsigned int plt_offset = plt_entry_size; | |
516 | unsigned int plt_rel_offset = 0; | |
517 | unsigned int got_offset = 12; | |
518 | const unsigned int count = this->count_; | |
519 | for (unsigned int i = 0; | |
520 | i < count; | |
521 | ++i, | |
522 | pov += plt_entry_size, | |
523 | got_pov += 4, | |
524 | plt_offset += plt_entry_size, | |
525 | plt_rel_offset += rel_size, | |
526 | got_offset += 4) | |
527 | { | |
528 | // Set and adjust the PLT entry itself. | |
529 | ||
7e1edb90 | 530 | if (parameters->output_is_shared()) |
a3ad94ed ILT |
531 | { |
532 | memcpy(pov, dyn_plt_entry, plt_entry_size); | |
533 | elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset); | |
534 | } | |
535 | else | |
536 | { | |
537 | memcpy(pov, exec_plt_entry, plt_entry_size); | |
538 | elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, | |
539 | (got_address | |
540 | + got_offset)); | |
541 | } | |
542 | ||
543 | elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset); | |
544 | elfcpp::Swap<32, false>::writeval(pov + 12, | |
545 | - (plt_offset + plt_entry_size)); | |
546 | ||
547 | // Set the entry in the GOT. | |
548 | elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6); | |
549 | } | |
550 | ||
551 | gold_assert(pov - oview == oview_size); | |
552 | gold_assert(got_pov - got_view == got_size); | |
553 | ||
554 | of->write_output_view(offset, oview_size, oview); | |
555 | of->write_output_view(got_file_offset, got_size, got_view); | |
556 | } | |
557 | ||
558 | // Create a PLT entry for a global symbol. | |
559 | ||
560 | void | |
7e1edb90 | 561 | Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym) |
a3ad94ed ILT |
562 | { |
563 | if (gsym->has_plt_offset()) | |
564 | return; | |
565 | ||
566 | if (this->plt_ == NULL) | |
567 | { | |
568 | // Create the GOT sections first. | |
7e1edb90 | 569 | this->got_section(symtab, layout); |
a3ad94ed | 570 | |
7e1edb90 | 571 | this->plt_ = new Output_data_plt_i386(layout, this->got_plt_); |
16649710 ILT |
572 | layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS, |
573 | (elfcpp::SHF_ALLOC | |
574 | | elfcpp::SHF_EXECINSTR), | |
575 | this->plt_); | |
a3ad94ed ILT |
576 | } |
577 | ||
578 | this->plt_->add_entry(gsym); | |
579 | } | |
580 | ||
581 | // Handle a relocation against a non-function symbol defined in a | |
582 | // dynamic object. The traditional way to handle this is to generate | |
583 | // a COPY relocation to copy the variable at runtime from the shared | |
584 | // object into the executable's data segment. However, this is | |
585 | // undesirable in general, as if the size of the object changes in the | |
586 | // dynamic object, the executable will no longer work correctly. If | |
587 | // this relocation is in a writable section, then we can create a | |
588 | // dynamic reloc and the dynamic linker will resolve it to the correct | |
589 | // address at runtime. However, we do not want do that if the | |
590 | // relocation is in a read-only section, as it would prevent the | |
591 | // readonly segment from being shared. And if we have to eventually | |
592 | // generate a COPY reloc, then any dynamic relocations will be | |
593 | // useless. So this means that if this is a writable section, we need | |
594 | // to save the relocation until we see whether we have to create a | |
595 | // COPY relocation for this symbol for any other relocation. | |
596 | ||
597 | void | |
598 | Target_i386::copy_reloc(const General_options* options, | |
5a6f7e2d ILT |
599 | Symbol_table* symtab, |
600 | Layout* layout, | |
a3ad94ed ILT |
601 | Sized_relobj<32, false>* object, |
602 | unsigned int data_shndx, Symbol* gsym, | |
5a6f7e2d | 603 | const elfcpp::Rel<32, false>& rel) |
a3ad94ed | 604 | { |
5a6f7e2d ILT |
605 | Sized_symbol<32>* ssym; |
606 | ssym = symtab->get_sized_symbol SELECT_SIZE_NAME(32) (gsym | |
607 | SELECT_SIZE(32)); | |
608 | ||
609 | if (!Copy_relocs<32, false>::need_copy_reloc(options, object, | |
610 | data_shndx, ssym)) | |
a3ad94ed ILT |
611 | { |
612 | // So far we do not need a COPY reloc. Save this relocation. | |
5a6f7e2d ILT |
613 | // If it turns out that we never need a COPY reloc for this |
614 | // symbol, then we will emit the relocation. | |
615 | if (this->copy_relocs_ == NULL) | |
616 | this->copy_relocs_ = new Copy_relocs<32, false>(); | |
617 | this->copy_relocs_->save(ssym, object, data_shndx, rel); | |
a3ad94ed | 618 | } |
5a6f7e2d ILT |
619 | else |
620 | { | |
621 | // Allocate space for this symbol in the .bss section. | |
622 | ||
623 | elfcpp::Elf_types<32>::Elf_WXword symsize = ssym->symsize(); | |
624 | ||
625 | // There is no defined way to determine the required alignment | |
626 | // of the symbol. We pick the alignment based on the size. We | |
627 | // set an arbitrary maximum of 256. | |
628 | unsigned int align; | |
629 | for (align = 1; align < 512; align <<= 1) | |
630 | if ((symsize & align) != 0) | |
631 | break; | |
a3ad94ed | 632 | |
5a6f7e2d ILT |
633 | if (this->dynbss_ == NULL) |
634 | { | |
635 | this->dynbss_ = new Output_data_space(align); | |
636 | layout->add_output_section_data(".bss", | |
637 | elfcpp::SHT_NOBITS, | |
638 | (elfcpp::SHF_ALLOC | |
639 | | elfcpp::SHF_WRITE), | |
640 | this->dynbss_); | |
641 | } | |
642 | ||
643 | Output_data_space* dynbss = this->dynbss_; | |
644 | ||
645 | if (align > dynbss->addralign()) | |
646 | dynbss->set_space_alignment(align); | |
647 | ||
648 | off_t dynbss_size = dynbss->data_size(); | |
649 | dynbss_size = align_address(dynbss_size, align); | |
650 | off_t offset = dynbss_size; | |
651 | dynbss->set_space_size(dynbss_size + symsize); | |
652 | ||
46fe1623 | 653 | symtab->define_with_copy_reloc(this, ssym, dynbss, offset); |
5a6f7e2d ILT |
654 | |
655 | // Add the COPY reloc. | |
656 | Reloc_section* rel_dyn = this->rel_dyn_section(layout); | |
657 | rel_dyn->add_global(ssym, elfcpp::R_386_COPY, dynbss, offset); | |
658 | } | |
a3ad94ed ILT |
659 | } |
660 | ||
92e059d8 | 661 | // Optimize the TLS relocation type based on what we know about the |
a3ad94ed ILT |
662 | // symbol. IS_FINAL is true if the final address of this symbol is |
663 | // known at link time. | |
92e059d8 | 664 | |
af6359d5 | 665 | tls::Tls_optimization |
7e1edb90 | 666 | Target_i386::optimize_tls_reloc(bool is_final, int r_type) |
92e059d8 ILT |
667 | { |
668 | // If we are generating a shared library, then we can't do anything | |
669 | // in the linker. | |
7e1edb90 | 670 | if (parameters->output_is_shared()) |
af6359d5 | 671 | return tls::TLSOPT_NONE; |
92e059d8 ILT |
672 | |
673 | switch (r_type) | |
674 | { | |
675 | case elfcpp::R_386_TLS_GD: | |
676 | case elfcpp::R_386_TLS_GOTDESC: | |
677 | case elfcpp::R_386_TLS_DESC_CALL: | |
e041f13d | 678 | // These are General-Dynamic which permits fully general TLS |
92e059d8 ILT |
679 | // access. Since we know that we are generating an executable, |
680 | // we can convert this to Initial-Exec. If we also know that | |
681 | // this is a local symbol, we can further switch to Local-Exec. | |
a3ad94ed | 682 | if (is_final) |
af6359d5 ILT |
683 | return tls::TLSOPT_TO_LE; |
684 | return tls::TLSOPT_TO_IE; | |
92e059d8 ILT |
685 | |
686 | case elfcpp::R_386_TLS_LDM: | |
687 | // This is Local-Dynamic, which refers to a local symbol in the | |
688 | // dynamic TLS block. Since we know that we generating an | |
689 | // executable, we can switch to Local-Exec. | |
af6359d5 | 690 | return tls::TLSOPT_TO_LE; |
92e059d8 ILT |
691 | |
692 | case elfcpp::R_386_TLS_LDO_32: | |
af6359d5 ILT |
693 | // Another type of Local-Dynamic relocation. |
694 | return tls::TLSOPT_TO_LE; | |
92e059d8 ILT |
695 | |
696 | case elfcpp::R_386_TLS_IE: | |
697 | case elfcpp::R_386_TLS_GOTIE: | |
698 | case elfcpp::R_386_TLS_IE_32: | |
699 | // These are Initial-Exec relocs which get the thread offset | |
700 | // from the GOT. If we know that we are linking against the | |
701 | // local symbol, we can switch to Local-Exec, which links the | |
702 | // thread offset into the instruction. | |
a3ad94ed | 703 | if (is_final) |
af6359d5 ILT |
704 | return tls::TLSOPT_TO_LE; |
705 | return tls::TLSOPT_NONE; | |
8462ae85 | 706 | |
92e059d8 ILT |
707 | case elfcpp::R_386_TLS_LE: |
708 | case elfcpp::R_386_TLS_LE_32: | |
709 | // When we already have Local-Exec, there is nothing further we | |
710 | // can do. | |
af6359d5 | 711 | return tls::TLSOPT_NONE; |
92e059d8 ILT |
712 | |
713 | default: | |
a3ad94ed | 714 | gold_unreachable(); |
92e059d8 ILT |
715 | } |
716 | } | |
717 | ||
af6359d5 ILT |
718 | // Report an unsupported relocation against a local symbol. |
719 | ||
720 | void | |
721 | Target_i386::Scan::unsupported_reloc_local(Sized_relobj<32, false>* object, | |
722 | unsigned int r_type) | |
723 | { | |
75f2446e ILT |
724 | gold_error(_("%s: unsupported reloc %u against local symbol"), |
725 | object->name().c_str(), r_type); | |
af6359d5 ILT |
726 | } |
727 | ||
92e059d8 ILT |
728 | // Scan a relocation for a local symbol. |
729 | ||
730 | inline void | |
7e1edb90 | 731 | Target_i386::Scan::local(const General_options&, |
ead1e424 ILT |
732 | Symbol_table* symtab, |
733 | Layout* layout, | |
734 | Target_i386* target, | |
f6ce93d6 | 735 | Sized_relobj<32, false>* object, |
1b64748b ILT |
736 | unsigned int data_shndx, |
737 | const elfcpp::Rel<32, false>& reloc, | |
a3ad94ed | 738 | unsigned int r_type, |
92e059d8 ILT |
739 | const elfcpp::Sym<32, false>&) |
740 | { | |
741 | switch (r_type) | |
742 | { | |
743 | case elfcpp::R_386_NONE: | |
744 | case elfcpp::R_386_GNU_VTINHERIT: | |
745 | case elfcpp::R_386_GNU_VTENTRY: | |
746 | break; | |
747 | ||
748 | case elfcpp::R_386_32: | |
749 | case elfcpp::R_386_16: | |
750 | case elfcpp::R_386_8: | |
436ca963 ILT |
751 | // If building a shared library (or a position-independent |
752 | // executable), we need to create a dynamic relocation for | |
753 | // this location. The relocation applied at link time will | |
754 | // apply the link-time value, so we flag the location with | |
755 | // an R_386_RELATIVE relocation so the dynamic loader can | |
756 | // relocate it easily. | |
757 | if (parameters->output_is_position_independent()) | |
758 | { | |
759 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); | |
760 | rel_dyn->add_local(object, 0, elfcpp::R_386_RELATIVE, data_shndx, | |
761 | reloc.get_r_offset()); | |
762 | } | |
92e059d8 ILT |
763 | break; |
764 | ||
765 | case elfcpp::R_386_PC32: | |
766 | case elfcpp::R_386_PC16: | |
767 | case elfcpp::R_386_PC8: | |
768 | break; | |
769 | ||
df2efe71 ILT |
770 | case elfcpp::R_386_PLT32: |
771 | // Since we know this is a local symbol, we can handle this as a | |
772 | // PC32 reloc. | |
773 | break; | |
774 | ||
ead1e424 ILT |
775 | case elfcpp::R_386_GOTOFF: |
776 | case elfcpp::R_386_GOTPC: | |
777 | // We need a GOT section. | |
7e1edb90 | 778 | target->got_section(symtab, layout); |
ead1e424 ILT |
779 | break; |
780 | ||
1b64748b ILT |
781 | case elfcpp::R_386_GOT32: |
782 | { | |
783 | // The symbol requires a GOT entry. | |
784 | Output_data_got<32, false>* got = target->got_section(symtab, layout); | |
785 | unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); | |
786 | if (got->add_local(object, r_sym)) | |
787 | { | |
788 | // If we are generating a shared object, we need to add a | |
789 | // dynamic RELATIVE relocation for this symbol. | |
436ca963 | 790 | if (parameters->output_is_position_independent()) |
1b64748b ILT |
791 | { |
792 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); | |
793 | rel_dyn->add_local(object, 0, elfcpp::R_386_RELATIVE, | |
794 | data_shndx, reloc.get_r_offset()); | |
795 | } | |
796 | } | |
797 | } | |
798 | break; | |
799 | ||
af6359d5 ILT |
800 | // These are relocations which should only be seen by the |
801 | // dynamic linker, and should never be seen here. | |
92e059d8 ILT |
802 | case elfcpp::R_386_COPY: |
803 | case elfcpp::R_386_GLOB_DAT: | |
804 | case elfcpp::R_386_JUMP_SLOT: | |
805 | case elfcpp::R_386_RELATIVE: | |
806 | case elfcpp::R_386_TLS_TPOFF: | |
807 | case elfcpp::R_386_TLS_DTPMOD32: | |
808 | case elfcpp::R_386_TLS_DTPOFF32: | |
809 | case elfcpp::R_386_TLS_TPOFF32: | |
810 | case elfcpp::R_386_TLS_DESC: | |
a0c4fb0a | 811 | gold_error(_("%s: unexpected reloc %u in object file"), |
75f2446e | 812 | object->name().c_str(), r_type); |
92e059d8 ILT |
813 | break; |
814 | ||
af6359d5 | 815 | // These are initial TLS relocs, which are expected when |
d61c17ea | 816 | // linking. |
56622147 ILT |
817 | case elfcpp::R_386_TLS_GD: // Global-dynamic |
818 | case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url) | |
819 | case elfcpp::R_386_TLS_DESC_CALL: | |
820 | case elfcpp::R_386_TLS_LDM: // Local-dynamic | |
821 | case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic | |
822 | case elfcpp::R_386_TLS_IE: // Initial-exec | |
92e059d8 | 823 | case elfcpp::R_386_TLS_IE_32: |
56622147 ILT |
824 | case elfcpp::R_386_TLS_GOTIE: |
825 | case elfcpp::R_386_TLS_LE: // Local-exec | |
92e059d8 | 826 | case elfcpp::R_386_TLS_LE_32: |
7e1edb90 | 827 | { |
80576242 | 828 | bool output_is_shared = parameters->output_is_shared(); |
af6359d5 ILT |
829 | const tls::Tls_optimization optimized_type |
830 | = Target_i386::optimize_tls_reloc(!output_is_shared, r_type); | |
7e1edb90 ILT |
831 | switch (r_type) |
832 | { | |
56622147 ILT |
833 | case elfcpp::R_386_TLS_GD: // Global-dynamic |
834 | case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva) | |
835 | case elfcpp::R_386_TLS_DESC_CALL: | |
836 | // FIXME: If not relaxing to LE, we need to generate | |
837 | // DTPMOD32 and DTPOFF32 relocs. | |
af6359d5 ILT |
838 | if (optimized_type != tls::TLSOPT_TO_LE) |
839 | unsupported_reloc_local(object, r_type); | |
840 | break; | |
841 | ||
56622147 | 842 | case elfcpp::R_386_TLS_LDM: // Local-dynamic |
af6359d5 ILT |
843 | // FIXME: If not relaxing to LE, we need to generate a |
844 | // DTPMOD32 reloc. | |
845 | if (optimized_type != tls::TLSOPT_TO_LE) | |
846 | unsupported_reloc_local(object, r_type); | |
847 | break; | |
848 | ||
56622147 | 849 | case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic |
46cf9fa2 ILT |
850 | break; |
851 | ||
56622147 ILT |
852 | case elfcpp::R_386_TLS_IE: // Initial-exec |
853 | case elfcpp::R_386_TLS_IE_32: | |
854 | case elfcpp::R_386_TLS_GOTIE: | |
855 | // FIXME: If not relaxing to LE, we need to generate a | |
856 | // TPOFF or TPOFF32 reloc. | |
af6359d5 ILT |
857 | if (optimized_type != tls::TLSOPT_TO_LE) |
858 | unsupported_reloc_local(object, r_type); | |
7e1edb90 | 859 | break; |
af6359d5 | 860 | |
56622147 ILT |
861 | case elfcpp::R_386_TLS_LE: // Local-exec |
862 | case elfcpp::R_386_TLS_LE_32: | |
863 | // FIXME: If generating a shared object, we need to copy | |
864 | // this relocation into the object. | |
865 | gold_assert(!output_is_shared); | |
866 | break; | |
867 | ||
af6359d5 ILT |
868 | default: |
869 | gold_unreachable(); | |
7e1edb90 ILT |
870 | } |
871 | } | |
92e059d8 ILT |
872 | break; |
873 | ||
92e059d8 ILT |
874 | case elfcpp::R_386_32PLT: |
875 | case elfcpp::R_386_TLS_GD_32: | |
876 | case elfcpp::R_386_TLS_GD_PUSH: | |
877 | case elfcpp::R_386_TLS_GD_CALL: | |
878 | case elfcpp::R_386_TLS_GD_POP: | |
879 | case elfcpp::R_386_TLS_LDM_32: | |
880 | case elfcpp::R_386_TLS_LDM_PUSH: | |
881 | case elfcpp::R_386_TLS_LDM_CALL: | |
882 | case elfcpp::R_386_TLS_LDM_POP: | |
883 | case elfcpp::R_386_USED_BY_INTEL_200: | |
884 | default: | |
af6359d5 | 885 | unsupported_reloc_local(object, r_type); |
92e059d8 ILT |
886 | break; |
887 | } | |
888 | } | |
889 | ||
af6359d5 ILT |
890 | // Report an unsupported relocation against a global symbol. |
891 | ||
892 | void | |
893 | Target_i386::Scan::unsupported_reloc_global(Sized_relobj<32, false>* object, | |
894 | unsigned int r_type, | |
895 | Symbol* gsym) | |
896 | { | |
75f2446e ILT |
897 | gold_error(_("%s: unsupported reloc %u against global symbol %s"), |
898 | object->name().c_str(), r_type, gsym->name()); | |
af6359d5 ILT |
899 | } |
900 | ||
92e059d8 ILT |
901 | // Scan a relocation for a global symbol. |
902 | ||
903 | inline void | |
904 | Target_i386::Scan::global(const General_options& options, | |
ead1e424 ILT |
905 | Symbol_table* symtab, |
906 | Layout* layout, | |
907 | Target_i386* target, | |
f6ce93d6 | 908 | Sized_relobj<32, false>* object, |
a3ad94ed ILT |
909 | unsigned int data_shndx, |
910 | const elfcpp::Rel<32, false>& reloc, | |
911 | unsigned int r_type, | |
92e059d8 ILT |
912 | Symbol* gsym) |
913 | { | |
914 | switch (r_type) | |
915 | { | |
916 | case elfcpp::R_386_NONE: | |
917 | case elfcpp::R_386_GNU_VTINHERIT: | |
8462ae85 | 918 | case elfcpp::R_386_GNU_VTENTRY: |
92e059d8 ILT |
919 | break; |
920 | ||
921 | case elfcpp::R_386_32: | |
922 | case elfcpp::R_386_PC32: | |
923 | case elfcpp::R_386_16: | |
924 | case elfcpp::R_386_PC16: | |
925 | case elfcpp::R_386_8: | |
926 | case elfcpp::R_386_PC8: | |
436ca963 ILT |
927 | if (gsym->is_from_dynobj() |
928 | || (parameters->output_is_shared() | |
929 | && gsym->is_preemptible())) | |
a3ad94ed | 930 | { |
436ca963 | 931 | // (a) This symbol is defined in a dynamic object. If it is a |
a3ad94ed ILT |
932 | // function, we make a PLT entry. Otherwise we need to |
933 | // either generate a COPY reloc or copy this reloc. | |
436ca963 ILT |
934 | // (b) We are building a shared object and this symbol is |
935 | // preemptible. If it is a function, we make a PLT entry. | |
936 | // Otherwise, we copy the reloc. We do not make COPY relocs | |
937 | // in shared objects. | |
a3ad94ed | 938 | if (gsym->type() == elfcpp::STT_FUNC) |
ab5c9e90 ILT |
939 | { |
940 | target->make_plt_entry(symtab, layout, gsym); | |
941 | ||
942 | // If this is not a PC relative reference, then we may | |
943 | // be taking the address of the function. In that case | |
944 | // we need to set the entry in the dynamic symbol table | |
945 | // to the address of the PLT entry. | |
946 | if (r_type != elfcpp::R_386_PC32 | |
947 | && r_type != elfcpp::R_386_PC16 | |
436ca963 ILT |
948 | && r_type != elfcpp::R_386_PC8 |
949 | && gsym->is_from_dynobj()) | |
ab5c9e90 ILT |
950 | gsym->set_needs_dynsym_value(); |
951 | } | |
436ca963 ILT |
952 | else if (parameters->output_is_shared()) |
953 | { | |
954 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); | |
955 | rel_dyn->add_global(gsym, r_type, object, data_shndx, | |
956 | reloc.get_r_offset()); | |
957 | } | |
a3ad94ed | 958 | else |
5a6f7e2d ILT |
959 | target->copy_reloc(&options, symtab, layout, object, data_shndx, |
960 | gsym, reloc); | |
a3ad94ed ILT |
961 | } |
962 | ||
92e059d8 ILT |
963 | break; |
964 | ||
ead1e424 | 965 | case elfcpp::R_386_GOT32: |
8462ae85 ILT |
966 | { |
967 | // The symbol requires a GOT entry. | |
7e1edb90 | 968 | Output_data_got<32, false>* got = target->got_section(symtab, layout); |
8462ae85 ILT |
969 | if (got->add_global(gsym)) |
970 | { | |
971 | // If this symbol is not fully resolved, we need to add a | |
972 | // dynamic relocation for it. | |
7e1edb90 | 973 | if (!gsym->final_value_is_known()) |
8462ae85 ILT |
974 | { |
975 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); | |
976 | rel_dyn->add_global(gsym, elfcpp::R_386_GLOB_DAT, got, | |
977 | gsym->got_offset()); | |
978 | } | |
979 | } | |
980 | } | |
ead1e424 ILT |
981 | break; |
982 | ||
983 | case elfcpp::R_386_PLT32: | |
a3ad94ed ILT |
984 | // If the symbol is fully resolved, this is just a PC32 reloc. |
985 | // Otherwise we need a PLT entry. | |
7e1edb90 | 986 | if (gsym->final_value_is_known()) |
ead1e424 | 987 | break; |
436ca963 ILT |
988 | // If building a shared library, we can also skip the PLT entry |
989 | // if the symbol is defined in the output file and is protected | |
990 | // or hidden. | |
991 | if (gsym->is_defined() | |
992 | && !gsym->is_from_dynobj() | |
993 | && !gsym->is_preemptible()) | |
994 | break; | |
7e1edb90 | 995 | target->make_plt_entry(symtab, layout, gsym); |
ead1e424 ILT |
996 | break; |
997 | ||
998 | case elfcpp::R_386_GOTOFF: | |
999 | case elfcpp::R_386_GOTPC: | |
1000 | // We need a GOT section. | |
7e1edb90 | 1001 | target->got_section(symtab, layout); |
ead1e424 ILT |
1002 | break; |
1003 | ||
af6359d5 ILT |
1004 | // These are relocations which should only be seen by the |
1005 | // dynamic linker, and should never be seen here. | |
92e059d8 ILT |
1006 | case elfcpp::R_386_COPY: |
1007 | case elfcpp::R_386_GLOB_DAT: | |
1008 | case elfcpp::R_386_JUMP_SLOT: | |
1009 | case elfcpp::R_386_RELATIVE: | |
1010 | case elfcpp::R_386_TLS_TPOFF: | |
1011 | case elfcpp::R_386_TLS_DTPMOD32: | |
1012 | case elfcpp::R_386_TLS_DTPOFF32: | |
1013 | case elfcpp::R_386_TLS_TPOFF32: | |
1014 | case elfcpp::R_386_TLS_DESC: | |
75f2446e ILT |
1015 | gold_error(_("%s: unexpected reloc %u in object file"), |
1016 | object->name().c_str(), r_type); | |
92e059d8 ILT |
1017 | break; |
1018 | ||
d61c17ea ILT |
1019 | // These are initial tls relocs, which are expected when |
1020 | // linking. | |
56622147 ILT |
1021 | case elfcpp::R_386_TLS_GD: // Global-dynamic |
1022 | case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url) | |
1023 | case elfcpp::R_386_TLS_DESC_CALL: | |
1024 | case elfcpp::R_386_TLS_LDM: // Local-dynamic | |
1025 | case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic | |
1026 | case elfcpp::R_386_TLS_IE: // Initial-exec | |
92e059d8 | 1027 | case elfcpp::R_386_TLS_IE_32: |
56622147 ILT |
1028 | case elfcpp::R_386_TLS_GOTIE: |
1029 | case elfcpp::R_386_TLS_LE: // Local-exec | |
92e059d8 | 1030 | case elfcpp::R_386_TLS_LE_32: |
a3ad94ed | 1031 | { |
7e1edb90 | 1032 | const bool is_final = gsym->final_value_is_known(); |
af6359d5 ILT |
1033 | const tls::Tls_optimization optimized_type |
1034 | = Target_i386::optimize_tls_reloc(is_final, r_type); | |
a3ad94ed ILT |
1035 | switch (r_type) |
1036 | { | |
56622147 ILT |
1037 | case elfcpp::R_386_TLS_GD: // Global-dynamic |
1038 | case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (~oliva url) | |
1039 | case elfcpp::R_386_TLS_DESC_CALL: | |
1040 | // FIXME: If not relaxing to LE, we need to generate | |
1041 | // DTPMOD32 and DTPOFF32 relocs. | |
af6359d5 ILT |
1042 | if (optimized_type != tls::TLSOPT_TO_LE) |
1043 | unsupported_reloc_global(object, r_type, gsym); | |
1044 | break; | |
1045 | ||
56622147 | 1046 | case elfcpp::R_386_TLS_LDM: // Local-dynamic |
af6359d5 ILT |
1047 | // FIXME: If not relaxing to LE, we need to generate a |
1048 | // DTPMOD32 reloc. | |
1049 | if (optimized_type != tls::TLSOPT_TO_LE) | |
1050 | unsupported_reloc_global(object, r_type, gsym); | |
1051 | break; | |
1052 | ||
56622147 | 1053 | case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic |
46cf9fa2 ILT |
1054 | break; |
1055 | ||
56622147 ILT |
1056 | case elfcpp::R_386_TLS_IE: // Initial-exec |
1057 | case elfcpp::R_386_TLS_IE_32: | |
1058 | case elfcpp::R_386_TLS_GOTIE: | |
1059 | // FIXME: If not relaxing to LE, we need to generate a | |
1060 | // TPOFF or TPOFF32 reloc. | |
af6359d5 ILT |
1061 | if (optimized_type != tls::TLSOPT_TO_LE) |
1062 | unsupported_reloc_global(object, r_type, gsym); | |
a3ad94ed | 1063 | break; |
af6359d5 | 1064 | |
56622147 ILT |
1065 | case elfcpp::R_386_TLS_LE: // Local-exec |
1066 | case elfcpp::R_386_TLS_LE_32: | |
1067 | // FIXME: If generating a shared object, we need to copy | |
1068 | // this relocation into the object. | |
1069 | gold_assert(!parameters->output_is_shared()); | |
1070 | break; | |
1071 | ||
af6359d5 ILT |
1072 | default: |
1073 | gold_unreachable(); | |
a3ad94ed ILT |
1074 | } |
1075 | } | |
92e059d8 ILT |
1076 | break; |
1077 | ||
92e059d8 ILT |
1078 | case elfcpp::R_386_32PLT: |
1079 | case elfcpp::R_386_TLS_GD_32: | |
1080 | case elfcpp::R_386_TLS_GD_PUSH: | |
1081 | case elfcpp::R_386_TLS_GD_CALL: | |
1082 | case elfcpp::R_386_TLS_GD_POP: | |
1083 | case elfcpp::R_386_TLS_LDM_32: | |
1084 | case elfcpp::R_386_TLS_LDM_PUSH: | |
1085 | case elfcpp::R_386_TLS_LDM_CALL: | |
1086 | case elfcpp::R_386_TLS_LDM_POP: | |
1087 | case elfcpp::R_386_USED_BY_INTEL_200: | |
1088 | default: | |
af6359d5 | 1089 | unsupported_reloc_global(object, r_type, gsym); |
92e059d8 ILT |
1090 | break; |
1091 | } | |
1092 | } | |
1093 | ||
1094 | // Scan relocations for a section. | |
1095 | ||
1096 | void | |
1097 | Target_i386::scan_relocs(const General_options& options, | |
1098 | Symbol_table* symtab, | |
ead1e424 | 1099 | Layout* layout, |
f6ce93d6 | 1100 | Sized_relobj<32, false>* object, |
a3ad94ed | 1101 | unsigned int data_shndx, |
92e059d8 ILT |
1102 | unsigned int sh_type, |
1103 | const unsigned char* prelocs, | |
1104 | size_t reloc_count, | |
1105 | size_t local_symbol_count, | |
1106 | const unsigned char* plocal_symbols, | |
1107 | Symbol** global_symbols) | |
1108 | { | |
1109 | if (sh_type == elfcpp::SHT_RELA) | |
1110 | { | |
75f2446e ILT |
1111 | gold_error(_("%s: unsupported RELA reloc section"), |
1112 | object->name().c_str()); | |
1113 | return; | |
92e059d8 ILT |
1114 | } |
1115 | ||
ead1e424 ILT |
1116 | gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL, |
1117 | Target_i386::Scan>( | |
92e059d8 ILT |
1118 | options, |
1119 | symtab, | |
ead1e424 ILT |
1120 | layout, |
1121 | this, | |
92e059d8 | 1122 | object, |
a3ad94ed | 1123 | data_shndx, |
92e059d8 ILT |
1124 | prelocs, |
1125 | reloc_count, | |
1126 | local_symbol_count, | |
1127 | plocal_symbols, | |
1128 | global_symbols); | |
1129 | } | |
1130 | ||
16649710 | 1131 | // Finalize the sections. |
5a6f7e2d ILT |
1132 | |
1133 | void | |
7e1edb90 | 1134 | Target_i386::do_finalize_sections(Layout* layout) |
5a6f7e2d | 1135 | { |
16649710 ILT |
1136 | // Fill in some more dynamic tags. |
1137 | Output_data_dynamic* const odyn = layout->dynamic_data(); | |
1138 | if (odyn != NULL) | |
1139 | { | |
1140 | if (this->got_plt_ != NULL) | |
1141 | odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_); | |
1142 | ||
1143 | if (this->plt_ != NULL) | |
1144 | { | |
1145 | const Output_data* od = this->plt_->rel_plt(); | |
1146 | odyn->add_section_size(elfcpp::DT_PLTRELSZ, od); | |
1147 | odyn->add_section_address(elfcpp::DT_JMPREL, od); | |
1148 | odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_REL); | |
1149 | } | |
1150 | ||
1151 | if (this->rel_dyn_ != NULL) | |
1152 | { | |
1153 | const Output_data* od = this->rel_dyn_; | |
1154 | odyn->add_section_address(elfcpp::DT_REL, od); | |
1155 | odyn->add_section_size(elfcpp::DT_RELSZ, od); | |
1156 | odyn->add_constant(elfcpp::DT_RELENT, | |
1157 | elfcpp::Elf_sizes<32>::rel_size); | |
1158 | } | |
1159 | ||
7e1edb90 | 1160 | if (!parameters->output_is_shared()) |
16649710 ILT |
1161 | { |
1162 | // The value of the DT_DEBUG tag is filled in by the dynamic | |
1163 | // linker at run time, and used by the debugger. | |
1164 | odyn->add_constant(elfcpp::DT_DEBUG, 0); | |
1165 | } | |
1166 | } | |
1167 | ||
1168 | // Emit any relocs we saved in an attempt to avoid generating COPY | |
1169 | // relocs. | |
5a6f7e2d ILT |
1170 | if (this->copy_relocs_ == NULL) |
1171 | return; | |
1172 | if (this->copy_relocs_->any_to_emit()) | |
1173 | { | |
1174 | Reloc_section* rel_dyn = this->rel_dyn_section(layout); | |
1175 | this->copy_relocs_->emit(rel_dyn); | |
1176 | } | |
1177 | delete this->copy_relocs_; | |
1178 | this->copy_relocs_ = NULL; | |
1179 | } | |
1180 | ||
61ba1cf9 ILT |
1181 | // Perform a relocation. |
1182 | ||
ead1e424 | 1183 | inline bool |
92e059d8 | 1184 | Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo, |
ead1e424 | 1185 | Target_i386* target, |
92e059d8 ILT |
1186 | size_t relnum, |
1187 | const elfcpp::Rel<32, false>& rel, | |
1188 | unsigned int r_type, | |
c06b7b0b | 1189 | const Sized_symbol<32>* gsym, |
b8e6aad9 | 1190 | const Symbol_value<32>* psymval, |
92e059d8 ILT |
1191 | unsigned char* view, |
1192 | elfcpp::Elf_types<32>::Elf_Addr address, | |
1193 | off_t view_size) | |
61ba1cf9 | 1194 | { |
ead1e424 ILT |
1195 | if (this->skip_call_tls_get_addr_) |
1196 | { | |
1197 | if (r_type != elfcpp::R_386_PLT32 | |
1198 | || gsym == NULL | |
1199 | || strcmp(gsym->name(), "___tls_get_addr") != 0) | |
75f2446e ILT |
1200 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
1201 | _("missing expected TLS relocation")); | |
1202 | else | |
ead1e424 | 1203 | { |
75f2446e ILT |
1204 | this->skip_call_tls_get_addr_ = false; |
1205 | return false; | |
ead1e424 | 1206 | } |
ead1e424 ILT |
1207 | } |
1208 | ||
a3ad94ed | 1209 | // Pick the value to use for symbols defined in shared objects. |
b8e6aad9 | 1210 | Symbol_value<32> symval; |
436ca963 ILT |
1211 | if (gsym != NULL |
1212 | && (gsym->is_from_dynobj() | |
1213 | || (parameters->output_is_shared() | |
1214 | && gsym->is_preemptible())) | |
1215 | && gsym->has_plt_offset()) | |
a3ad94ed | 1216 | { |
b8e6aad9 ILT |
1217 | symval.set_output_value(target->plt_section()->address() |
1218 | + gsym->plt_offset()); | |
1219 | psymval = &symval; | |
a3ad94ed ILT |
1220 | } |
1221 | ||
b8e6aad9 ILT |
1222 | const Sized_relobj<32, false>* object = relinfo->object; |
1223 | ||
1b64748b ILT |
1224 | // Get the GOT offset if needed. |
1225 | bool have_got_offset = false; | |
1226 | unsigned int got_offset = 0; | |
1227 | switch (r_type) | |
1228 | { | |
1229 | case elfcpp::R_386_GOT32: | |
1230 | if (gsym != NULL) | |
1231 | { | |
1232 | gold_assert(gsym->has_got_offset()); | |
1233 | got_offset = gsym->got_offset(); | |
1234 | } | |
1235 | else | |
1236 | { | |
1237 | unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info()); | |
1238 | got_offset = object->local_got_offset(r_sym); | |
1239 | } | |
1240 | have_got_offset = true; | |
1241 | break; | |
1242 | ||
1243 | default: | |
1244 | break; | |
1245 | } | |
1246 | ||
61ba1cf9 ILT |
1247 | switch (r_type) |
1248 | { | |
1249 | case elfcpp::R_386_NONE: | |
92e059d8 ILT |
1250 | case elfcpp::R_386_GNU_VTINHERIT: |
1251 | case elfcpp::R_386_GNU_VTENTRY: | |
61ba1cf9 ILT |
1252 | break; |
1253 | ||
1254 | case elfcpp::R_386_32: | |
b8e6aad9 | 1255 | Relocate_functions<32, false>::rel32(view, object, psymval); |
61ba1cf9 ILT |
1256 | break; |
1257 | ||
1258 | case elfcpp::R_386_PC32: | |
b8e6aad9 | 1259 | Relocate_functions<32, false>::pcrel32(view, object, psymval, address); |
92e059d8 ILT |
1260 | break; |
1261 | ||
1262 | case elfcpp::R_386_16: | |
b8e6aad9 | 1263 | Relocate_functions<32, false>::rel16(view, object, psymval); |
92e059d8 ILT |
1264 | break; |
1265 | ||
1266 | case elfcpp::R_386_PC16: | |
b8e6aad9 | 1267 | Relocate_functions<32, false>::pcrel16(view, object, psymval, address); |
61ba1cf9 ILT |
1268 | break; |
1269 | ||
92e059d8 | 1270 | case elfcpp::R_386_8: |
b8e6aad9 | 1271 | Relocate_functions<32, false>::rel8(view, object, psymval); |
92e059d8 ILT |
1272 | break; |
1273 | ||
1274 | case elfcpp::R_386_PC8: | |
b8e6aad9 | 1275 | Relocate_functions<32, false>::pcrel8(view, object, psymval, address); |
92e059d8 ILT |
1276 | break; |
1277 | ||
ead1e424 | 1278 | case elfcpp::R_386_PLT32: |
df2efe71 ILT |
1279 | gold_assert(gsym == NULL |
1280 | || gsym->has_plt_offset() | |
1281 | || gsym->final_value_is_known()); | |
b8e6aad9 | 1282 | Relocate_functions<32, false>::pcrel32(view, object, psymval, address); |
ead1e424 ILT |
1283 | break; |
1284 | ||
1285 | case elfcpp::R_386_GOT32: | |
1b64748b ILT |
1286 | gold_assert(have_got_offset); |
1287 | Relocate_functions<32, false>::rel32(view, got_offset); | |
ead1e424 ILT |
1288 | break; |
1289 | ||
1290 | case elfcpp::R_386_GOTOFF: | |
b8e6aad9 ILT |
1291 | { |
1292 | elfcpp::Elf_types<32>::Elf_Addr value; | |
1293 | value = (psymval->value(object, 0) | |
7e1edb90 | 1294 | - target->got_section(NULL, NULL)->address()); |
b8e6aad9 ILT |
1295 | Relocate_functions<32, false>::rel32(view, value); |
1296 | } | |
ead1e424 ILT |
1297 | break; |
1298 | ||
1299 | case elfcpp::R_386_GOTPC: | |
b8e6aad9 ILT |
1300 | { |
1301 | elfcpp::Elf_types<32>::Elf_Addr value; | |
7e1edb90 | 1302 | value = target->got_section(NULL, NULL)->address(); |
b8e6aad9 ILT |
1303 | Relocate_functions<32, false>::pcrel32(view, value, address); |
1304 | } | |
ead1e424 ILT |
1305 | break; |
1306 | ||
92e059d8 ILT |
1307 | case elfcpp::R_386_COPY: |
1308 | case elfcpp::R_386_GLOB_DAT: | |
1309 | case elfcpp::R_386_JUMP_SLOT: | |
1310 | case elfcpp::R_386_RELATIVE: | |
d61c17ea ILT |
1311 | // These are outstanding tls relocs, which are unexpected when |
1312 | // linking. | |
92e059d8 ILT |
1313 | case elfcpp::R_386_TLS_TPOFF: |
1314 | case elfcpp::R_386_TLS_DTPMOD32: | |
1315 | case elfcpp::R_386_TLS_DTPOFF32: | |
1316 | case elfcpp::R_386_TLS_TPOFF32: | |
1317 | case elfcpp::R_386_TLS_DESC: | |
75f2446e ILT |
1318 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
1319 | _("unexpected reloc %u in object file"), | |
1320 | r_type); | |
92e059d8 ILT |
1321 | break; |
1322 | ||
d61c17ea ILT |
1323 | // These are initial tls relocs, which are expected when |
1324 | // linking. | |
56622147 ILT |
1325 | case elfcpp::R_386_TLS_GD: // Global-dynamic |
1326 | case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url) | |
1327 | case elfcpp::R_386_TLS_DESC_CALL: | |
1328 | case elfcpp::R_386_TLS_LDM: // Local-dynamic | |
1329 | case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic | |
1330 | case elfcpp::R_386_TLS_IE: // Initial-exec | |
92e059d8 | 1331 | case elfcpp::R_386_TLS_IE_32: |
56622147 ILT |
1332 | case elfcpp::R_386_TLS_GOTIE: |
1333 | case elfcpp::R_386_TLS_LE: // Local-exec | |
92e059d8 | 1334 | case elfcpp::R_386_TLS_LE_32: |
b8e6aad9 | 1335 | this->relocate_tls(relinfo, relnum, rel, r_type, gsym, psymval, view, |
ead1e424 | 1336 | address, view_size); |
92e059d8 ILT |
1337 | break; |
1338 | ||
92e059d8 ILT |
1339 | case elfcpp::R_386_32PLT: |
1340 | case elfcpp::R_386_TLS_GD_32: | |
1341 | case elfcpp::R_386_TLS_GD_PUSH: | |
1342 | case elfcpp::R_386_TLS_GD_CALL: | |
1343 | case elfcpp::R_386_TLS_GD_POP: | |
1344 | case elfcpp::R_386_TLS_LDM_32: | |
1345 | case elfcpp::R_386_TLS_LDM_PUSH: | |
1346 | case elfcpp::R_386_TLS_LDM_CALL: | |
1347 | case elfcpp::R_386_TLS_LDM_POP: | |
1348 | case elfcpp::R_386_USED_BY_INTEL_200: | |
61ba1cf9 | 1349 | default: |
75f2446e ILT |
1350 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
1351 | _("unsupported reloc %u"), | |
1352 | r_type); | |
92e059d8 ILT |
1353 | break; |
1354 | } | |
ead1e424 ILT |
1355 | |
1356 | return true; | |
92e059d8 ILT |
1357 | } |
1358 | ||
1359 | // Perform a TLS relocation. | |
1360 | ||
1361 | inline void | |
1362 | Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo, | |
1363 | size_t relnum, | |
1364 | const elfcpp::Rel<32, false>& rel, | |
1365 | unsigned int r_type, | |
c06b7b0b | 1366 | const Sized_symbol<32>* gsym, |
b8e6aad9 | 1367 | const Symbol_value<32>* psymval, |
92e059d8 ILT |
1368 | unsigned char* view, |
1369 | elfcpp::Elf_types<32>::Elf_Addr, | |
1370 | off_t view_size) | |
1371 | { | |
1372 | Output_segment* tls_segment = relinfo->layout->tls_segment(); | |
1373 | if (tls_segment == NULL) | |
1374 | { | |
75f2446e ILT |
1375 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
1376 | _("TLS reloc but no TLS segment")); | |
1377 | return; | |
92e059d8 ILT |
1378 | } |
1379 | ||
b8e6aad9 ILT |
1380 | elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(relinfo->object, 0); |
1381 | ||
a3ad94ed | 1382 | const bool is_final = (gsym == NULL |
436ca963 | 1383 | ? !parameters->output_is_position_independent() |
7e1edb90 | 1384 | : gsym->final_value_is_known()); |
af6359d5 ILT |
1385 | const tls::Tls_optimization optimized_type |
1386 | = Target_i386::optimize_tls_reloc(is_final, r_type); | |
92e059d8 ILT |
1387 | switch (r_type) |
1388 | { | |
56622147 | 1389 | case elfcpp::R_386_TLS_GD: // Global-dynamic |
af6359d5 | 1390 | if (optimized_type == tls::TLSOPT_TO_LE) |
92e059d8 | 1391 | { |
56622147 ILT |
1392 | this->tls_gd_to_le(relinfo, relnum, tls_segment, |
1393 | rel, r_type, value, view, | |
1394 | view_size); | |
92e059d8 ILT |
1395 | break; |
1396 | } | |
75f2446e ILT |
1397 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
1398 | _("unsupported reloc %u"), | |
1399 | r_type); | |
92e059d8 ILT |
1400 | break; |
1401 | ||
56622147 ILT |
1402 | case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url) |
1403 | case elfcpp::R_386_TLS_DESC_CALL: | |
75f2446e ILT |
1404 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
1405 | _("unsupported reloc %u"), | |
1406 | r_type); | |
ead1e424 ILT |
1407 | break; |
1408 | ||
56622147 | 1409 | case elfcpp::R_386_TLS_LDM: // Local-dynamic |
46cf9fa2 ILT |
1410 | if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN) |
1411 | { | |
75f2446e ILT |
1412 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
1413 | _("both SUN and GNU model " | |
1414 | "TLS relocations")); | |
1415 | break; | |
46cf9fa2 ILT |
1416 | } |
1417 | this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU; | |
af6359d5 | 1418 | if (optimized_type == tls::TLSOPT_TO_LE) |
46cf9fa2 ILT |
1419 | { |
1420 | this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, r_type, | |
1421 | value, view, view_size); | |
1422 | break; | |
1423 | } | |
75f2446e ILT |
1424 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
1425 | _("unsupported reloc %u"), | |
1426 | r_type); | |
46cf9fa2 ILT |
1427 | break; |
1428 | ||
56622147 | 1429 | case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic |
46cf9fa2 ILT |
1430 | // This reloc can appear in debugging sections, in which case we |
1431 | // won't see the TLS_LDM reloc. The local_dynamic_type field | |
1432 | // tells us this. | |
af6359d5 | 1433 | if (optimized_type != tls::TLSOPT_TO_LE |
46cf9fa2 ILT |
1434 | || this->local_dynamic_type_ == LOCAL_DYNAMIC_NONE) |
1435 | value = value - tls_segment->vaddr(); | |
1436 | else if (this->local_dynamic_type_ == LOCAL_DYNAMIC_GNU) | |
1437 | value = value - (tls_segment->vaddr() + tls_segment->memsz()); | |
1438 | else | |
1439 | value = tls_segment->vaddr() + tls_segment->memsz() - value; | |
1440 | Relocate_functions<32, false>::rel32(view, value); | |
1441 | break; | |
1442 | ||
56622147 ILT |
1443 | case elfcpp::R_386_TLS_IE: // Initial-exec |
1444 | case elfcpp::R_386_TLS_GOTIE: | |
1445 | case elfcpp::R_386_TLS_IE_32: | |
1446 | if (optimized_type == tls::TLSOPT_TO_LE) | |
1447 | { | |
1448 | Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment, | |
1449 | rel, r_type, value, view, | |
1450 | view_size); | |
1451 | break; | |
1452 | } | |
75f2446e ILT |
1453 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
1454 | _("unsupported reloc %u"), | |
1455 | r_type); | |
92e059d8 | 1456 | break; |
92e059d8 | 1457 | |
56622147 ILT |
1458 | case elfcpp::R_386_TLS_LE: // Local-exec |
1459 | value = value - (tls_segment->vaddr() + tls_segment->memsz()); | |
1460 | Relocate_functions<32, false>::rel32(view, value); | |
1461 | break; | |
92e059d8 | 1462 | |
56622147 ILT |
1463 | case elfcpp::R_386_TLS_LE_32: |
1464 | value = tls_segment->vaddr() + tls_segment->memsz() - value; | |
1465 | Relocate_functions<32, false>::rel32(view, value); | |
1466 | break; | |
92e059d8 | 1467 | } |
92e059d8 ILT |
1468 | } |
1469 | ||
e041f13d | 1470 | // Do a relocation in which we convert a TLS General-Dynamic to a |
ead1e424 ILT |
1471 | // Local-Exec. |
1472 | ||
1473 | inline void | |
1474 | Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo, | |
1475 | size_t relnum, | |
1476 | Output_segment* tls_segment, | |
1477 | const elfcpp::Rel<32, false>& rel, | |
1478 | unsigned int, | |
1479 | elfcpp::Elf_types<32>::Elf_Addr value, | |
1480 | unsigned char* view, | |
1481 | off_t view_size) | |
1482 | { | |
1483 | // leal foo(,%reg,1),%eax; call ___tls_get_addr | |
46cf9fa2 | 1484 | // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax |
ead1e424 ILT |
1485 | // leal foo(%reg),%eax; call ___tls_get_addr |
1486 | // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax | |
1487 | ||
af6359d5 ILT |
1488 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2); |
1489 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9); | |
ead1e424 ILT |
1490 | |
1491 | unsigned char op1 = view[-1]; | |
1492 | unsigned char op2 = view[-2]; | |
1493 | ||
af6359d5 ILT |
1494 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
1495 | op2 == 0x8d || op2 == 0x04); | |
1496 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8); | |
ead1e424 ILT |
1497 | |
1498 | int roff = 5; | |
1499 | ||
1500 | if (op2 == 0x04) | |
1501 | { | |
af6359d5 ILT |
1502 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3); |
1503 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d); | |
1504 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), | |
1505 | ((op1 & 0xc7) == 0x05 && op1 != (4 << 3))); | |
ead1e424 ILT |
1506 | memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12); |
1507 | } | |
1508 | else | |
1509 | { | |
af6359d5 ILT |
1510 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
1511 | (op1 & 0xf8) == 0x80 && (op1 & 7) != 4); | |
d61c17ea ILT |
1512 | if (static_cast<off_t>(rel.get_r_offset() + 9) < view_size |
1513 | && view[9] == 0x90) | |
ead1e424 ILT |
1514 | { |
1515 | // There is a trailing nop. Use the size byte subl. | |
1516 | memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12); | |
1517 | roff = 6; | |
1518 | } | |
1519 | else | |
1520 | { | |
1521 | // Use the five byte subl. | |
1522 | memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11); | |
1523 | } | |
1524 | } | |
1525 | ||
1526 | value = tls_segment->vaddr() + tls_segment->memsz() - value; | |
1527 | Relocate_functions<32, false>::rel32(view + roff, value); | |
1528 | ||
1529 | // The next reloc should be a PLT32 reloc against __tls_get_addr. | |
1530 | // We can skip it. | |
1531 | this->skip_call_tls_get_addr_ = true; | |
1532 | } | |
1533 | ||
46cf9fa2 ILT |
1534 | // Do a relocation in which we convert a TLS Local-Dynamic to a |
1535 | // Local-Exec. | |
1536 | ||
1537 | inline void | |
1538 | Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo, | |
1539 | size_t relnum, | |
1540 | Output_segment*, | |
1541 | const elfcpp::Rel<32, false>& rel, | |
1542 | unsigned int, | |
1543 | elfcpp::Elf_types<32>::Elf_Addr, | |
1544 | unsigned char* view, | |
1545 | off_t view_size) | |
1546 | { | |
1547 | // leal foo(%reg), %eax; call ___tls_get_addr | |
1548 | // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi | |
1549 | ||
af6359d5 ILT |
1550 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2); |
1551 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9); | |
46cf9fa2 ILT |
1552 | |
1553 | // FIXME: Does this test really always pass? | |
af6359d5 ILT |
1554 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
1555 | view[-2] == 0x8d && view[-1] == 0x83); | |
46cf9fa2 | 1556 | |
af6359d5 | 1557 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8); |
46cf9fa2 ILT |
1558 | |
1559 | memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11); | |
1560 | ||
1561 | // The next reloc should be a PLT32 reloc against __tls_get_addr. | |
1562 | // We can skip it. | |
1563 | this->skip_call_tls_get_addr_ = true; | |
1564 | } | |
1565 | ||
56622147 ILT |
1566 | // Do a relocation in which we convert a TLS Initial-Exec to a |
1567 | // Local-Exec. | |
1568 | ||
1569 | inline void | |
1570 | Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo, | |
1571 | size_t relnum, | |
1572 | Output_segment* tls_segment, | |
1573 | const elfcpp::Rel<32, false>& rel, | |
1574 | unsigned int r_type, | |
1575 | elfcpp::Elf_types<32>::Elf_Addr value, | |
1576 | unsigned char* view, | |
1577 | off_t view_size) | |
1578 | { | |
1579 | // We have to actually change the instructions, which means that we | |
1580 | // need to examine the opcodes to figure out which instruction we | |
1581 | // are looking at. | |
1582 | if (r_type == elfcpp::R_386_TLS_IE) | |
1583 | { | |
1584 | // movl %gs:XX,%eax ==> movl $YY,%eax | |
1585 | // movl %gs:XX,%reg ==> movl $YY,%reg | |
1586 | // addl %gs:XX,%reg ==> addl $YY,%reg | |
1587 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -1); | |
1588 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4); | |
1589 | ||
1590 | unsigned char op1 = view[-1]; | |
1591 | if (op1 == 0xa1) | |
1592 | { | |
1593 | // movl XX,%eax ==> movl $YY,%eax | |
1594 | view[-1] = 0xb8; | |
1595 | } | |
1596 | else | |
1597 | { | |
1598 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2); | |
1599 | ||
1600 | unsigned char op2 = view[-2]; | |
1601 | if (op2 == 0x8b) | |
1602 | { | |
1603 | // movl XX,%reg ==> movl $YY,%reg | |
1604 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), | |
1605 | (op1 & 0xc7) == 0x05); | |
1606 | view[-2] = 0xc7; | |
1607 | view[-1] = 0xc0 | ((op1 >> 3) & 7); | |
1608 | } | |
1609 | else if (op2 == 0x03) | |
1610 | { | |
1611 | // addl XX,%reg ==> addl $YY,%reg | |
1612 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), | |
1613 | (op1 & 0xc7) == 0x05); | |
1614 | view[-2] = 0x81; | |
1615 | view[-1] = 0xc0 | ((op1 >> 3) & 7); | |
1616 | } | |
1617 | else | |
1618 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0); | |
1619 | } | |
1620 | } | |
1621 | else | |
1622 | { | |
1623 | // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2 | |
1624 | // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2 | |
1625 | // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2 | |
1626 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2); | |
1627 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4); | |
1628 | ||
1629 | unsigned char op1 = view[-1]; | |
1630 | unsigned char op2 = view[-2]; | |
1631 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), | |
1632 | (op1 & 0xc0) == 0x80 && (op1 & 7) != 4); | |
1633 | if (op2 == 0x8b) | |
1634 | { | |
1635 | // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2 | |
1636 | view[-2] = 0xc7; | |
1637 | view[-1] = 0xc0 | ((op1 >> 3) & 7); | |
1638 | } | |
1639 | else if (op2 == 0x2b) | |
1640 | { | |
1641 | // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2 | |
1642 | view[-2] = 0x81; | |
1643 | view[-1] = 0xe8 | ((op1 >> 3) & 7); | |
1644 | } | |
1645 | else if (op2 == 0x03) | |
1646 | { | |
1647 | // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2 | |
1648 | view[-2] = 0x81; | |
1649 | view[-1] = 0xc0 | ((op1 >> 3) & 7); | |
1650 | } | |
1651 | else | |
1652 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0); | |
1653 | } | |
1654 | ||
1655 | value = tls_segment->vaddr() + tls_segment->memsz() - value; | |
1656 | if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE) | |
1657 | value = - value; | |
1658 | ||
1659 | Relocate_functions<32, false>::rel32(view, value); | |
1660 | } | |
1661 | ||
61ba1cf9 ILT |
1662 | // Relocate section data. |
1663 | ||
1664 | void | |
92e059d8 | 1665 | Target_i386::relocate_section(const Relocate_info<32, false>* relinfo, |
61ba1cf9 ILT |
1666 | unsigned int sh_type, |
1667 | const unsigned char* prelocs, | |
1668 | size_t reloc_count, | |
61ba1cf9 ILT |
1669 | unsigned char* view, |
1670 | elfcpp::Elf_types<32>::Elf_Addr address, | |
1671 | off_t view_size) | |
1672 | { | |
a3ad94ed | 1673 | gold_assert(sh_type == elfcpp::SHT_REL); |
61ba1cf9 | 1674 | |
ead1e424 ILT |
1675 | gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL, |
1676 | Target_i386::Relocate>( | |
92e059d8 | 1677 | relinfo, |
ead1e424 | 1678 | this, |
61ba1cf9 ILT |
1679 | prelocs, |
1680 | reloc_count, | |
61ba1cf9 ILT |
1681 | view, |
1682 | address, | |
1683 | view_size); | |
1684 | } | |
1685 | ||
ab5c9e90 ILT |
1686 | // Return the value to use for a dynamic which requires special |
1687 | // treatment. This is how we support equality comparisons of function | |
1688 | // pointers across shared library boundaries, as described in the | |
1689 | // processor specific ABI supplement. | |
1690 | ||
1691 | uint64_t | |
1692 | Target_i386::do_dynsym_value(const Symbol* gsym) const | |
1693 | { | |
1694 | gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset()); | |
1695 | return this->plt_section()->address() + gsym->plt_offset(); | |
1696 | } | |
1697 | ||
c51e6221 ILT |
1698 | // Return a string used to fill a code section with nops to take up |
1699 | // the specified length. | |
1700 | ||
1701 | std::string | |
1702 | Target_i386::do_code_fill(off_t length) | |
1703 | { | |
1704 | if (length >= 16) | |
1705 | { | |
1706 | // Build a jmp instruction to skip over the bytes. | |
1707 | unsigned char jmp[5]; | |
1708 | jmp[0] = 0xe9; | |
1709 | elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5); | |
1710 | return (std::string(reinterpret_cast<char*>(&jmp[0]), 5) | |
1711 | + std::string(length - 5, '\0')); | |
1712 | } | |
1713 | ||
1714 | // Nop sequences of various lengths. | |
1715 | const char nop1[1] = { 0x90 }; // nop | |
1716 | const char nop2[2] = { 0x66, 0x90 }; // xchg %ax %ax | |
1717 | const char nop3[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi | |
1718 | const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi | |
1719 | const char nop5[5] = { 0x90, 0x8d, 0x74, 0x26, // nop | |
1720 | 0x00 }; // leal 0(%esi,1),%esi | |
1721 | const char nop6[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi | |
1722 | 0x00, 0x00 }; | |
1723 | const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi | |
1724 | 0x00, 0x00, 0x00 }; | |
1725 | const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop | |
1726 | 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi | |
1727 | const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi | |
1728 | 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi | |
1729 | 0x00 }; | |
1730 | const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi | |
1731 | 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi | |
1732 | 0x00, 0x00 }; | |
1733 | const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi | |
1734 | 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi | |
1735 | 0x00, 0x00, 0x00 }; | |
1736 | const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi | |
1737 | 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi | |
1738 | 0x00, 0x00, 0x00, 0x00 }; | |
1739 | const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi | |
1740 | 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi | |
1741 | 0x27, 0x00, 0x00, 0x00, | |
1742 | 0x00 }; | |
1743 | const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi | |
1744 | 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi | |
1745 | 0xbc, 0x27, 0x00, 0x00, | |
1746 | 0x00, 0x00 }; | |
1747 | const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15 | |
1748 | 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,... | |
1749 | 0x90, 0x90, 0x90, 0x90, | |
1750 | 0x90, 0x90, 0x90 }; | |
1751 | ||
1752 | const char* nops[16] = { | |
1753 | NULL, | |
1754 | nop1, nop2, nop3, nop4, nop5, nop6, nop7, | |
1755 | nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15 | |
1756 | }; | |
1757 | ||
1758 | return std::string(nops[length], length); | |
1759 | } | |
1760 | ||
14bfc3f5 ILT |
1761 | // The selector for i386 object files. |
1762 | ||
1763 | class Target_selector_i386 : public Target_selector | |
1764 | { | |
1765 | public: | |
1766 | Target_selector_i386() | |
1767 | : Target_selector(elfcpp::EM_386, 32, false) | |
1768 | { } | |
1769 | ||
1770 | Target* | |
ead1e424 ILT |
1771 | recognize(int machine, int osabi, int abiversion); |
1772 | ||
1773 | private: | |
1774 | Target_i386* target_; | |
14bfc3f5 ILT |
1775 | }; |
1776 | ||
1777 | // Recognize an i386 object file when we already know that the machine | |
1778 | // number is EM_386. | |
1779 | ||
1780 | Target* | |
ead1e424 | 1781 | Target_selector_i386::recognize(int, int, int) |
14bfc3f5 | 1782 | { |
ead1e424 ILT |
1783 | if (this->target_ == NULL) |
1784 | this->target_ = new Target_i386(); | |
1785 | return this->target_; | |
14bfc3f5 ILT |
1786 | } |
1787 | ||
1788 | Target_selector_i386 target_selector_i386; | |
1789 | ||
1790 | } // End anonymous namespace. |