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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, | |
730cdc88 ILT |
73 | Output_section* output_section, |
74 | bool needs_special_offset_handling, | |
92e059d8 | 75 | size_t local_symbol_count, |
730cdc88 | 76 | const unsigned char* plocal_symbols); |
61ba1cf9 | 77 | |
5a6f7e2d ILT |
78 | // Finalize the sections. |
79 | void | |
7e1edb90 | 80 | do_finalize_sections(Layout*); |
5a6f7e2d | 81 | |
ab5c9e90 ILT |
82 | // Return the value to use for a dynamic which requires special |
83 | // treatment. | |
84 | uint64_t | |
85 | do_dynsym_value(const Symbol*) const; | |
86 | ||
92e059d8 ILT |
87 | // Relocate a section. |
88 | void | |
89 | relocate_section(const Relocate_info<32, false>*, | |
90 | unsigned int sh_type, | |
91 | const unsigned char* prelocs, | |
92 | size_t reloc_count, | |
730cdc88 ILT |
93 | Output_section* output_section, |
94 | bool needs_special_offset_handling, | |
92e059d8 ILT |
95 | unsigned char* view, |
96 | elfcpp::Elf_types<32>::Elf_Addr view_address, | |
97 | off_t view_size); | |
98 | ||
c51e6221 ILT |
99 | // Return a string used to fill a code section with nops. |
100 | std::string | |
101 | do_code_fill(off_t length); | |
102 | ||
9a2d6984 ILT |
103 | // Return whether SYM is defined by the ABI. |
104 | bool | |
105 | do_is_defined_by_abi(Symbol* sym) const | |
106 | { return strcmp(sym->name(), "___tls_get_addr") == 0; } | |
107 | ||
96f2030e ILT |
108 | // Return the size of the GOT section. |
109 | off_t | |
110 | got_size() | |
111 | { | |
112 | gold_assert(this->got_ != NULL); | |
113 | return this->got_->data_size(); | |
114 | } | |
115 | ||
92e059d8 ILT |
116 | private: |
117 | // The class which scans relocations. | |
118 | struct Scan | |
61ba1cf9 ILT |
119 | { |
120 | inline void | |
ead1e424 ILT |
121 | local(const General_options& options, Symbol_table* symtab, |
122 | Layout* layout, Target_i386* target, | |
f6ce93d6 | 123 | Sized_relobj<32, false>* object, |
a3ad94ed | 124 | unsigned int data_shndx, |
07f397ab | 125 | Output_section* output_section, |
92e059d8 ILT |
126 | const elfcpp::Rel<32, false>& reloc, unsigned int r_type, |
127 | const elfcpp::Sym<32, false>& lsym); | |
61ba1cf9 | 128 | |
92e059d8 | 129 | inline void |
ead1e424 ILT |
130 | global(const General_options& options, Symbol_table* symtab, |
131 | Layout* layout, Target_i386* target, | |
f6ce93d6 | 132 | Sized_relobj<32, false>* object, |
a3ad94ed | 133 | unsigned int data_shndx, |
07f397ab | 134 | Output_section* output_section, |
92e059d8 ILT |
135 | const elfcpp::Rel<32, false>& reloc, unsigned int r_type, |
136 | Symbol* gsym); | |
af6359d5 ILT |
137 | |
138 | static void | |
139 | unsupported_reloc_local(Sized_relobj<32, false>*, unsigned int r_type); | |
140 | ||
141 | static void | |
142 | unsupported_reloc_global(Sized_relobj<32, false>*, unsigned int r_type, | |
143 | Symbol*); | |
61ba1cf9 ILT |
144 | }; |
145 | ||
92e059d8 ILT |
146 | // The class which implements relocation. |
147 | class Relocate | |
148 | { | |
149 | public: | |
ead1e424 | 150 | Relocate() |
46cf9fa2 ILT |
151 | : skip_call_tls_get_addr_(false), |
152 | local_dynamic_type_(LOCAL_DYNAMIC_NONE) | |
ead1e424 ILT |
153 | { } |
154 | ||
155 | ~Relocate() | |
156 | { | |
157 | if (this->skip_call_tls_get_addr_) | |
158 | { | |
159 | // FIXME: This needs to specify the location somehow. | |
75f2446e | 160 | gold_error(_("missing expected TLS relocation")); |
ead1e424 ILT |
161 | } |
162 | } | |
163 | ||
86849f1f ILT |
164 | // Return whether the static relocation needs to be applied. |
165 | inline bool | |
166 | should_apply_static_reloc(const Sized_symbol<32>* gsym, | |
d61c6bd4 ILT |
167 | bool is_absolute_ref, |
168 | bool is_function_call, | |
86849f1f ILT |
169 | bool is_32bit); |
170 | ||
ead1e424 ILT |
171 | // Do a relocation. Return false if the caller should not issue |
172 | // any warnings about this relocation. | |
173 | inline bool | |
174 | relocate(const Relocate_info<32, false>*, Target_i386*, size_t relnum, | |
92e059d8 | 175 | const elfcpp::Rel<32, false>&, |
c06b7b0b | 176 | unsigned int r_type, const Sized_symbol<32>*, |
b8e6aad9 | 177 | const Symbol_value<32>*, |
92e059d8 ILT |
178 | unsigned char*, elfcpp::Elf_types<32>::Elf_Addr, |
179 | off_t); | |
180 | ||
181 | private: | |
182 | // Do a TLS relocation. | |
ead1e424 | 183 | inline void |
07f397ab ILT |
184 | relocate_tls(const Relocate_info<32, false>*, Target_i386* target, |
185 | size_t relnum, const elfcpp::Rel<32, false>&, | |
c06b7b0b | 186 | unsigned int r_type, const Sized_symbol<32>*, |
b8e6aad9 | 187 | const Symbol_value<32>*, |
92e059d8 ILT |
188 | unsigned char*, elfcpp::Elf_types<32>::Elf_Addr, off_t); |
189 | ||
07f397ab ILT |
190 | // Do a TLS General-Dynamic to Initial-Exec transition. |
191 | inline void | |
192 | tls_gd_to_ie(const Relocate_info<32, false>*, size_t relnum, | |
193 | Output_segment* tls_segment, | |
194 | const elfcpp::Rel<32, false>&, unsigned int r_type, | |
195 | elfcpp::Elf_types<32>::Elf_Addr value, | |
196 | unsigned char* view, | |
197 | off_t view_size); | |
198 | ||
56622147 ILT |
199 | // Do a TLS General-Dynamic to Local-Exec transition. |
200 | inline void | |
201 | tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum, | |
92e059d8 ILT |
202 | Output_segment* tls_segment, |
203 | const elfcpp::Rel<32, false>&, unsigned int r_type, | |
204 | elfcpp::Elf_types<32>::Elf_Addr value, | |
205 | unsigned char* view, | |
206 | off_t view_size); | |
207 | ||
56622147 | 208 | // Do a TLS Local-Dynamic to Local-Exec transition. |
ead1e424 | 209 | inline void |
56622147 | 210 | tls_ld_to_le(const Relocate_info<32, false>*, size_t relnum, |
ead1e424 ILT |
211 | Output_segment* tls_segment, |
212 | const elfcpp::Rel<32, false>&, unsigned int r_type, | |
213 | elfcpp::Elf_types<32>::Elf_Addr value, | |
214 | unsigned char* view, | |
215 | off_t view_size); | |
216 | ||
56622147 ILT |
217 | // Do a TLS Initial-Exec to Local-Exec transition. |
218 | static inline void | |
219 | tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum, | |
46cf9fa2 ILT |
220 | Output_segment* tls_segment, |
221 | const elfcpp::Rel<32, false>&, unsigned int r_type, | |
222 | elfcpp::Elf_types<32>::Elf_Addr value, | |
223 | unsigned char* view, | |
224 | off_t view_size); | |
225 | ||
46cf9fa2 ILT |
226 | // We need to keep track of which type of local dynamic relocation |
227 | // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly. | |
228 | enum Local_dynamic_type | |
229 | { | |
230 | LOCAL_DYNAMIC_NONE, | |
231 | LOCAL_DYNAMIC_SUN, | |
232 | LOCAL_DYNAMIC_GNU | |
233 | }; | |
234 | ||
ead1e424 ILT |
235 | // This is set if we should skip the next reloc, which should be a |
236 | // PLT32 reloc against ___tls_get_addr. | |
237 | bool skip_call_tls_get_addr_; | |
46cf9fa2 ILT |
238 | // The type of local dynamic relocation we have seen in the section |
239 | // being relocated, if any. | |
240 | Local_dynamic_type local_dynamic_type_; | |
92e059d8 ILT |
241 | }; |
242 | ||
243 | // Adjust TLS relocation type based on the options and whether this | |
244 | // is a local symbol. | |
af6359d5 | 245 | static tls::Tls_optimization |
7e1edb90 | 246 | optimize_tls_reloc(bool is_final, int r_type); |
92e059d8 | 247 | |
ead1e424 | 248 | // Get the GOT section, creating it if necessary. |
dbe717ef | 249 | Output_data_got<32, false>* |
7e1edb90 | 250 | got_section(Symbol_table*, Layout*); |
a3ad94ed | 251 | |
96f2030e ILT |
252 | // Get the GOT PLT section. |
253 | Output_data_space* | |
254 | got_plt_section() const | |
255 | { | |
256 | gold_assert(this->got_plt_ != NULL); | |
257 | return this->got_plt_; | |
258 | } | |
259 | ||
a3ad94ed ILT |
260 | // Create a PLT entry for a global symbol. |
261 | void | |
7e1edb90 | 262 | make_plt_entry(Symbol_table*, Layout*, Symbol*); |
a3ad94ed ILT |
263 | |
264 | // Get the PLT section. | |
7bb3655e | 265 | const Output_data_plt_i386* |
a3ad94ed ILT |
266 | plt_section() const |
267 | { | |
268 | gold_assert(this->plt_ != NULL); | |
269 | return this->plt_; | |
270 | } | |
271 | ||
5a6f7e2d ILT |
272 | // Get the dynamic reloc section, creating it if necessary. |
273 | Reloc_section* | |
274 | rel_dyn_section(Layout*); | |
275 | ||
d61c6bd4 ILT |
276 | // Return true if the symbol may need a COPY relocation. |
277 | // References from an executable object to non-function symbols | |
278 | // defined in a dynamic object may need a COPY relocation. | |
279 | bool | |
280 | may_need_copy_reloc(Symbol* gsym) | |
281 | { | |
282 | return (!parameters->output_is_shared() | |
283 | && gsym->is_from_dynobj() | |
284 | && gsym->type() != elfcpp::STT_FUNC); | |
285 | } | |
286 | ||
a3ad94ed ILT |
287 | // Copy a relocation against a global symbol. |
288 | void | |
5a6f7e2d ILT |
289 | copy_reloc(const General_options*, Symbol_table*, Layout*, |
290 | Sized_relobj<32, false>*, unsigned int, | |
4f4c5f80 | 291 | Output_section*, Symbol*, const elfcpp::Rel<32, false>&); |
ead1e424 | 292 | |
92e059d8 ILT |
293 | // Information about this specific target which we pass to the |
294 | // general Target structure. | |
75f65a3e | 295 | static const Target::Target_info i386_info; |
ead1e424 ILT |
296 | |
297 | // The GOT section. | |
dbe717ef | 298 | Output_data_got<32, false>* got_; |
a3ad94ed ILT |
299 | // The PLT section. |
300 | Output_data_plt_i386* plt_; | |
301 | // The GOT PLT section. | |
302 | Output_data_space* got_plt_; | |
5a6f7e2d ILT |
303 | // The dynamic reloc section. |
304 | Reloc_section* rel_dyn_; | |
305 | // Relocs saved to avoid a COPY reloc. | |
306 | Copy_relocs<32, false>* copy_relocs_; | |
307 | // Space for variables copied with a COPY reloc. | |
308 | Output_data_space* dynbss_; | |
75f65a3e ILT |
309 | }; |
310 | ||
311 | const Target::Target_info Target_i386::i386_info = | |
312 | { | |
61ba1cf9 ILT |
313 | 32, // size |
314 | false, // is_big_endian | |
315 | elfcpp::EM_386, // machine_code | |
316 | false, // has_make_symbol | |
dbe717ef | 317 | false, // has_resolve |
c51e6221 | 318 | true, // has_code_fill |
35cdfc9a | 319 | true, // is_default_stack_executable |
dbe717ef | 320 | "/usr/lib/libc.so.1", // dynamic_linker |
0c5e9c22 | 321 | 0x08048000, // default_text_segment_address |
61ba1cf9 ILT |
322 | 0x1000, // abi_pagesize |
323 | 0x1000 // common_pagesize | |
14bfc3f5 ILT |
324 | }; |
325 | ||
ead1e424 ILT |
326 | // Get the GOT section, creating it if necessary. |
327 | ||
dbe717ef | 328 | Output_data_got<32, false>* |
7e1edb90 | 329 | Target_i386::got_section(Symbol_table* symtab, Layout* layout) |
ead1e424 ILT |
330 | { |
331 | if (this->got_ == NULL) | |
332 | { | |
7e1edb90 | 333 | gold_assert(symtab != NULL && layout != NULL); |
a3ad94ed | 334 | |
7e1edb90 | 335 | this->got_ = new Output_data_got<32, false>(); |
ead1e424 | 336 | |
ead1e424 | 337 | layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS, |
16649710 ILT |
338 | elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE, |
339 | this->got_); | |
ead1e424 | 340 | |
a3ad94ed ILT |
341 | // The old GNU linker creates a .got.plt section. We just |
342 | // create another set of data in the .got section. Note that we | |
343 | // always create a PLT if we create a GOT, although the PLT | |
344 | // might be empty. | |
345 | this->got_plt_ = new Output_data_space(4); | |
346 | layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS, | |
16649710 ILT |
347 | elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE, |
348 | this->got_plt_); | |
a3ad94ed | 349 | |
ead1e424 | 350 | // The first three entries are reserved. |
27bc2bce | 351 | this->got_plt_->set_current_data_size(3 * 4); |
ead1e424 | 352 | |
a3ad94ed | 353 | // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT. |
14b31740 | 354 | symtab->define_in_output_data(this, "_GLOBAL_OFFSET_TABLE_", NULL, |
a3ad94ed | 355 | this->got_plt_, |
ead1e424 | 356 | 0, 0, elfcpp::STT_OBJECT, |
16649710 | 357 | elfcpp::STB_LOCAL, |
ead1e424 ILT |
358 | elfcpp::STV_HIDDEN, 0, |
359 | false, false); | |
360 | } | |
a3ad94ed | 361 | |
ead1e424 ILT |
362 | return this->got_; |
363 | } | |
364 | ||
5a6f7e2d ILT |
365 | // Get the dynamic reloc section, creating it if necessary. |
366 | ||
367 | Target_i386::Reloc_section* | |
368 | Target_i386::rel_dyn_section(Layout* layout) | |
369 | { | |
370 | if (this->rel_dyn_ == NULL) | |
371 | { | |
372 | gold_assert(layout != NULL); | |
373 | this->rel_dyn_ = new Reloc_section(); | |
374 | layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL, | |
375 | elfcpp::SHF_ALLOC, this->rel_dyn_); | |
376 | } | |
377 | return this->rel_dyn_; | |
378 | } | |
379 | ||
a3ad94ed ILT |
380 | // A class to handle the PLT data. |
381 | ||
382 | class Output_data_plt_i386 : public Output_section_data | |
383 | { | |
384 | public: | |
385 | typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section; | |
386 | ||
7e1edb90 | 387 | Output_data_plt_i386(Layout*, Output_data_space*); |
a3ad94ed ILT |
388 | |
389 | // Add an entry to the PLT. | |
390 | void | |
391 | add_entry(Symbol* gsym); | |
392 | ||
16649710 ILT |
393 | // Return the .rel.plt section data. |
394 | const Reloc_section* | |
395 | rel_plt() const | |
396 | { return this->rel_; } | |
397 | ||
398 | protected: | |
399 | void | |
400 | do_adjust_output_section(Output_section* os); | |
401 | ||
a3ad94ed ILT |
402 | private: |
403 | // The size of an entry in the PLT. | |
404 | static const int plt_entry_size = 16; | |
405 | ||
406 | // The first entry in the PLT for an executable. | |
407 | static unsigned char exec_first_plt_entry[plt_entry_size]; | |
408 | ||
409 | // The first entry in the PLT for a shared object. | |
410 | static unsigned char dyn_first_plt_entry[plt_entry_size]; | |
411 | ||
412 | // Other entries in the PLT for an executable. | |
413 | static unsigned char exec_plt_entry[plt_entry_size]; | |
414 | ||
415 | // Other entries in the PLT for a shared object. | |
416 | static unsigned char dyn_plt_entry[plt_entry_size]; | |
417 | ||
418 | // Set the final size. | |
419 | void | |
27bc2bce | 420 | set_final_data_size() |
a3ad94ed ILT |
421 | { this->set_data_size((this->count_ + 1) * plt_entry_size); } |
422 | ||
423 | // Write out the PLT data. | |
424 | void | |
425 | do_write(Output_file*); | |
426 | ||
427 | // The reloc section. | |
428 | Reloc_section* rel_; | |
429 | // The .got.plt section. | |
430 | Output_data_space* got_plt_; | |
431 | // The number of PLT entries. | |
432 | unsigned int count_; | |
a3ad94ed ILT |
433 | }; |
434 | ||
435 | // Create the PLT section. The ordinary .got section is an argument, | |
436 | // since we need to refer to the start. We also create our own .got | |
437 | // section just for PLT entries. | |
438 | ||
439 | Output_data_plt_i386::Output_data_plt_i386(Layout* layout, | |
7e1edb90 | 440 | Output_data_space* got_plt) |
80576242 | 441 | : Output_section_data(4), got_plt_(got_plt), count_(0) |
a3ad94ed ILT |
442 | { |
443 | this->rel_ = new Reloc_section(); | |
444 | layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL, | |
445 | elfcpp::SHF_ALLOC, this->rel_); | |
446 | } | |
447 | ||
16649710 ILT |
448 | void |
449 | Output_data_plt_i386::do_adjust_output_section(Output_section* os) | |
450 | { | |
451 | // UnixWare sets the entsize of .plt to 4, and so does the old GNU | |
452 | // linker, and so do we. | |
453 | os->set_entsize(4); | |
454 | } | |
455 | ||
a3ad94ed ILT |
456 | // Add an entry to the PLT. |
457 | ||
458 | void | |
459 | Output_data_plt_i386::add_entry(Symbol* gsym) | |
460 | { | |
461 | gold_assert(!gsym->has_plt_offset()); | |
462 | ||
463 | // Note that when setting the PLT offset we skip the initial | |
464 | // reserved PLT entry. | |
465 | gsym->set_plt_offset((this->count_ + 1) * plt_entry_size); | |
466 | ||
467 | ++this->count_; | |
468 | ||
27bc2bce | 469 | off_t got_offset = this->got_plt_->current_data_size(); |
a3ad94ed ILT |
470 | |
471 | // Every PLT entry needs a GOT entry which points back to the PLT | |
472 | // entry (this will be changed by the dynamic linker, normally | |
473 | // lazily when the function is called). | |
27bc2bce | 474 | this->got_plt_->set_current_data_size(got_offset + 4); |
a3ad94ed ILT |
475 | |
476 | // Every PLT entry needs a reloc. | |
16649710 | 477 | gsym->set_needs_dynsym_entry(); |
a3ad94ed ILT |
478 | this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_, |
479 | got_offset); | |
480 | ||
481 | // Note that we don't need to save the symbol. The contents of the | |
482 | // PLT are independent of which symbols are used. The symbols only | |
483 | // appear in the relocations. | |
484 | } | |
485 | ||
486 | // The first entry in the PLT for an executable. | |
487 | ||
488 | unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] = | |
489 | { | |
490 | 0xff, 0x35, // pushl contents of memory address | |
491 | 0, 0, 0, 0, // replaced with address of .got + 4 | |
492 | 0xff, 0x25, // jmp indirect | |
493 | 0, 0, 0, 0, // replaced with address of .got + 8 | |
494 | 0, 0, 0, 0 // unused | |
495 | }; | |
496 | ||
497 | // The first entry in the PLT for a shared object. | |
498 | ||
499 | unsigned char Output_data_plt_i386::dyn_first_plt_entry[plt_entry_size] = | |
500 | { | |
501 | 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx) | |
502 | 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx) | |
503 | 0, 0, 0, 0 // unused | |
504 | }; | |
505 | ||
506 | // Subsequent entries in the PLT for an executable. | |
507 | ||
508 | unsigned char Output_data_plt_i386::exec_plt_entry[plt_entry_size] = | |
509 | { | |
510 | 0xff, 0x25, // jmp indirect | |
511 | 0, 0, 0, 0, // replaced with address of symbol in .got | |
512 | 0x68, // pushl immediate | |
513 | 0, 0, 0, 0, // replaced with offset into relocation table | |
514 | 0xe9, // jmp relative | |
515 | 0, 0, 0, 0 // replaced with offset to start of .plt | |
516 | }; | |
517 | ||
518 | // Subsequent entries in the PLT for a shared object. | |
519 | ||
520 | unsigned char Output_data_plt_i386::dyn_plt_entry[plt_entry_size] = | |
521 | { | |
522 | 0xff, 0xa3, // jmp *offset(%ebx) | |
523 | 0, 0, 0, 0, // replaced with offset of symbol in .got | |
524 | 0x68, // pushl immediate | |
525 | 0, 0, 0, 0, // replaced with offset into relocation table | |
526 | 0xe9, // jmp relative | |
527 | 0, 0, 0, 0 // replaced with offset to start of .plt | |
528 | }; | |
529 | ||
530 | // Write out the PLT. This uses the hand-coded instructions above, | |
531 | // and adjusts them as needed. This is all specified by the i386 ELF | |
532 | // Processor Supplement. | |
533 | ||
534 | void | |
535 | Output_data_plt_i386::do_write(Output_file* of) | |
536 | { | |
537 | const off_t offset = this->offset(); | |
538 | const off_t oview_size = this->data_size(); | |
539 | unsigned char* const oview = of->get_output_view(offset, oview_size); | |
540 | ||
541 | const off_t got_file_offset = this->got_plt_->offset(); | |
542 | const off_t got_size = this->got_plt_->data_size(); | |
543 | unsigned char* const got_view = of->get_output_view(got_file_offset, | |
544 | got_size); | |
545 | ||
546 | unsigned char* pov = oview; | |
547 | ||
548 | elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address(); | |
549 | elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address(); | |
550 | ||
7e1edb90 | 551 | if (parameters->output_is_shared()) |
a3ad94ed ILT |
552 | memcpy(pov, dyn_first_plt_entry, plt_entry_size); |
553 | else | |
554 | { | |
555 | memcpy(pov, exec_first_plt_entry, plt_entry_size); | |
556 | elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4); | |
557 | elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8); | |
558 | } | |
559 | pov += plt_entry_size; | |
560 | ||
561 | unsigned char* got_pov = got_view; | |
562 | ||
563 | memset(got_pov, 0, 12); | |
564 | got_pov += 12; | |
565 | ||
566 | const int rel_size = elfcpp::Elf_sizes<32>::rel_size; | |
567 | ||
568 | unsigned int plt_offset = plt_entry_size; | |
569 | unsigned int plt_rel_offset = 0; | |
570 | unsigned int got_offset = 12; | |
571 | const unsigned int count = this->count_; | |
572 | for (unsigned int i = 0; | |
573 | i < count; | |
574 | ++i, | |
575 | pov += plt_entry_size, | |
576 | got_pov += 4, | |
577 | plt_offset += plt_entry_size, | |
578 | plt_rel_offset += rel_size, | |
579 | got_offset += 4) | |
580 | { | |
581 | // Set and adjust the PLT entry itself. | |
582 | ||
7e1edb90 | 583 | if (parameters->output_is_shared()) |
a3ad94ed ILT |
584 | { |
585 | memcpy(pov, dyn_plt_entry, plt_entry_size); | |
586 | elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset); | |
587 | } | |
588 | else | |
589 | { | |
590 | memcpy(pov, exec_plt_entry, plt_entry_size); | |
591 | elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, | |
592 | (got_address | |
593 | + got_offset)); | |
594 | } | |
595 | ||
596 | elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset); | |
597 | elfcpp::Swap<32, false>::writeval(pov + 12, | |
598 | - (plt_offset + plt_entry_size)); | |
599 | ||
600 | // Set the entry in the GOT. | |
601 | elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6); | |
602 | } | |
603 | ||
604 | gold_assert(pov - oview == oview_size); | |
605 | gold_assert(got_pov - got_view == got_size); | |
606 | ||
607 | of->write_output_view(offset, oview_size, oview); | |
608 | of->write_output_view(got_file_offset, got_size, got_view); | |
609 | } | |
610 | ||
611 | // Create a PLT entry for a global symbol. | |
612 | ||
613 | void | |
7e1edb90 | 614 | Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym) |
a3ad94ed ILT |
615 | { |
616 | if (gsym->has_plt_offset()) | |
617 | return; | |
618 | ||
619 | if (this->plt_ == NULL) | |
620 | { | |
621 | // Create the GOT sections first. | |
7e1edb90 | 622 | this->got_section(symtab, layout); |
a3ad94ed | 623 | |
7e1edb90 | 624 | this->plt_ = new Output_data_plt_i386(layout, this->got_plt_); |
16649710 ILT |
625 | layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS, |
626 | (elfcpp::SHF_ALLOC | |
627 | | elfcpp::SHF_EXECINSTR), | |
628 | this->plt_); | |
a3ad94ed ILT |
629 | } |
630 | ||
631 | this->plt_->add_entry(gsym); | |
632 | } | |
633 | ||
634 | // Handle a relocation against a non-function symbol defined in a | |
635 | // dynamic object. The traditional way to handle this is to generate | |
636 | // a COPY relocation to copy the variable at runtime from the shared | |
637 | // object into the executable's data segment. However, this is | |
638 | // undesirable in general, as if the size of the object changes in the | |
639 | // dynamic object, the executable will no longer work correctly. If | |
640 | // this relocation is in a writable section, then we can create a | |
641 | // dynamic reloc and the dynamic linker will resolve it to the correct | |
642 | // address at runtime. However, we do not want do that if the | |
643 | // relocation is in a read-only section, as it would prevent the | |
644 | // readonly segment from being shared. And if we have to eventually | |
645 | // generate a COPY reloc, then any dynamic relocations will be | |
646 | // useless. So this means that if this is a writable section, we need | |
647 | // to save the relocation until we see whether we have to create a | |
648 | // COPY relocation for this symbol for any other relocation. | |
649 | ||
650 | void | |
651 | Target_i386::copy_reloc(const General_options* options, | |
5a6f7e2d ILT |
652 | Symbol_table* symtab, |
653 | Layout* layout, | |
a3ad94ed | 654 | Sized_relobj<32, false>* object, |
4f4c5f80 ILT |
655 | unsigned int data_shndx, |
656 | Output_section* output_section, | |
657 | Symbol* gsym, | |
5a6f7e2d | 658 | const elfcpp::Rel<32, false>& rel) |
a3ad94ed | 659 | { |
5a6f7e2d ILT |
660 | Sized_symbol<32>* ssym; |
661 | ssym = symtab->get_sized_symbol SELECT_SIZE_NAME(32) (gsym | |
662 | SELECT_SIZE(32)); | |
663 | ||
664 | if (!Copy_relocs<32, false>::need_copy_reloc(options, object, | |
665 | data_shndx, ssym)) | |
a3ad94ed ILT |
666 | { |
667 | // So far we do not need a COPY reloc. Save this relocation. | |
5a6f7e2d ILT |
668 | // If it turns out that we never need a COPY reloc for this |
669 | // symbol, then we will emit the relocation. | |
670 | if (this->copy_relocs_ == NULL) | |
671 | this->copy_relocs_ = new Copy_relocs<32, false>(); | |
4f4c5f80 | 672 | this->copy_relocs_->save(ssym, object, data_shndx, output_section, rel); |
a3ad94ed | 673 | } |
5a6f7e2d ILT |
674 | else |
675 | { | |
676 | // Allocate space for this symbol in the .bss section. | |
677 | ||
678 | elfcpp::Elf_types<32>::Elf_WXword symsize = ssym->symsize(); | |
679 | ||
680 | // There is no defined way to determine the required alignment | |
681 | // of the symbol. We pick the alignment based on the size. We | |
682 | // set an arbitrary maximum of 256. | |
683 | unsigned int align; | |
684 | for (align = 1; align < 512; align <<= 1) | |
685 | if ((symsize & align) != 0) | |
686 | break; | |
a3ad94ed | 687 | |
5a6f7e2d ILT |
688 | if (this->dynbss_ == NULL) |
689 | { | |
690 | this->dynbss_ = new Output_data_space(align); | |
691 | layout->add_output_section_data(".bss", | |
692 | elfcpp::SHT_NOBITS, | |
693 | (elfcpp::SHF_ALLOC | |
694 | | elfcpp::SHF_WRITE), | |
695 | this->dynbss_); | |
696 | } | |
697 | ||
698 | Output_data_space* dynbss = this->dynbss_; | |
699 | ||
700 | if (align > dynbss->addralign()) | |
701 | dynbss->set_space_alignment(align); | |
702 | ||
27bc2bce | 703 | off_t dynbss_size = dynbss->current_data_size(); |
5a6f7e2d ILT |
704 | dynbss_size = align_address(dynbss_size, align); |
705 | off_t offset = dynbss_size; | |
27bc2bce | 706 | dynbss->set_current_data_size(dynbss_size + symsize); |
5a6f7e2d | 707 | |
46fe1623 | 708 | symtab->define_with_copy_reloc(this, ssym, dynbss, offset); |
5a6f7e2d ILT |
709 | |
710 | // Add the COPY reloc. | |
711 | Reloc_section* rel_dyn = this->rel_dyn_section(layout); | |
712 | rel_dyn->add_global(ssym, elfcpp::R_386_COPY, dynbss, offset); | |
713 | } | |
a3ad94ed ILT |
714 | } |
715 | ||
92e059d8 | 716 | // Optimize the TLS relocation type based on what we know about the |
a3ad94ed ILT |
717 | // symbol. IS_FINAL is true if the final address of this symbol is |
718 | // known at link time. | |
92e059d8 | 719 | |
af6359d5 | 720 | tls::Tls_optimization |
7e1edb90 | 721 | Target_i386::optimize_tls_reloc(bool is_final, int r_type) |
92e059d8 ILT |
722 | { |
723 | // If we are generating a shared library, then we can't do anything | |
724 | // in the linker. | |
7e1edb90 | 725 | if (parameters->output_is_shared()) |
af6359d5 | 726 | return tls::TLSOPT_NONE; |
92e059d8 ILT |
727 | |
728 | switch (r_type) | |
729 | { | |
730 | case elfcpp::R_386_TLS_GD: | |
731 | case elfcpp::R_386_TLS_GOTDESC: | |
732 | case elfcpp::R_386_TLS_DESC_CALL: | |
e041f13d | 733 | // These are General-Dynamic which permits fully general TLS |
92e059d8 ILT |
734 | // access. Since we know that we are generating an executable, |
735 | // we can convert this to Initial-Exec. If we also know that | |
736 | // this is a local symbol, we can further switch to Local-Exec. | |
a3ad94ed | 737 | if (is_final) |
af6359d5 ILT |
738 | return tls::TLSOPT_TO_LE; |
739 | return tls::TLSOPT_TO_IE; | |
92e059d8 ILT |
740 | |
741 | case elfcpp::R_386_TLS_LDM: | |
742 | // This is Local-Dynamic, which refers to a local symbol in the | |
743 | // dynamic TLS block. Since we know that we generating an | |
744 | // executable, we can switch to Local-Exec. | |
af6359d5 | 745 | return tls::TLSOPT_TO_LE; |
92e059d8 ILT |
746 | |
747 | case elfcpp::R_386_TLS_LDO_32: | |
af6359d5 ILT |
748 | // Another type of Local-Dynamic relocation. |
749 | return tls::TLSOPT_TO_LE; | |
92e059d8 ILT |
750 | |
751 | case elfcpp::R_386_TLS_IE: | |
752 | case elfcpp::R_386_TLS_GOTIE: | |
753 | case elfcpp::R_386_TLS_IE_32: | |
754 | // These are Initial-Exec relocs which get the thread offset | |
755 | // from the GOT. If we know that we are linking against the | |
756 | // local symbol, we can switch to Local-Exec, which links the | |
757 | // thread offset into the instruction. | |
a3ad94ed | 758 | if (is_final) |
af6359d5 ILT |
759 | return tls::TLSOPT_TO_LE; |
760 | return tls::TLSOPT_NONE; | |
8462ae85 | 761 | |
92e059d8 ILT |
762 | case elfcpp::R_386_TLS_LE: |
763 | case elfcpp::R_386_TLS_LE_32: | |
764 | // When we already have Local-Exec, there is nothing further we | |
765 | // can do. | |
af6359d5 | 766 | return tls::TLSOPT_NONE; |
92e059d8 ILT |
767 | |
768 | default: | |
a3ad94ed | 769 | gold_unreachable(); |
92e059d8 ILT |
770 | } |
771 | } | |
772 | ||
af6359d5 ILT |
773 | // Report an unsupported relocation against a local symbol. |
774 | ||
775 | void | |
776 | Target_i386::Scan::unsupported_reloc_local(Sized_relobj<32, false>* object, | |
777 | unsigned int r_type) | |
778 | { | |
75f2446e ILT |
779 | gold_error(_("%s: unsupported reloc %u against local symbol"), |
780 | object->name().c_str(), r_type); | |
af6359d5 ILT |
781 | } |
782 | ||
92e059d8 ILT |
783 | // Scan a relocation for a local symbol. |
784 | ||
785 | inline void | |
7e1edb90 | 786 | Target_i386::Scan::local(const General_options&, |
ead1e424 ILT |
787 | Symbol_table* symtab, |
788 | Layout* layout, | |
789 | Target_i386* target, | |
f6ce93d6 | 790 | Sized_relobj<32, false>* object, |
1b64748b | 791 | unsigned int data_shndx, |
07f397ab | 792 | Output_section* output_section, |
1b64748b | 793 | const elfcpp::Rel<32, false>& reloc, |
a3ad94ed | 794 | unsigned int r_type, |
92e059d8 ILT |
795 | const elfcpp::Sym<32, false>&) |
796 | { | |
797 | switch (r_type) | |
798 | { | |
799 | case elfcpp::R_386_NONE: | |
800 | case elfcpp::R_386_GNU_VTINHERIT: | |
801 | case elfcpp::R_386_GNU_VTENTRY: | |
802 | break; | |
803 | ||
804 | case elfcpp::R_386_32: | |
436ca963 ILT |
805 | // If building a shared library (or a position-independent |
806 | // executable), we need to create a dynamic relocation for | |
807 | // this location. The relocation applied at link time will | |
808 | // apply the link-time value, so we flag the location with | |
809 | // an R_386_RELATIVE relocation so the dynamic loader can | |
810 | // relocate it easily. | |
811 | if (parameters->output_is_position_independent()) | |
812 | { | |
813 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); | |
4f4c5f80 ILT |
814 | rel_dyn->add_local(object, 0, elfcpp::R_386_RELATIVE, output_section, |
815 | data_shndx, reloc.get_r_offset()); | |
d61c6bd4 ILT |
816 | } |
817 | break; | |
818 | ||
819 | case elfcpp::R_386_16: | |
820 | case elfcpp::R_386_8: | |
821 | // If building a shared library (or a position-independent | |
822 | // executable), we need to create a dynamic relocation for | |
823 | // this location. Because the addend needs to remain in the | |
824 | // data section, we need to be careful not to apply this | |
825 | // relocation statically. | |
826 | if (parameters->output_is_position_independent()) | |
827 | { | |
828 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); | |
829 | unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); | |
4f4c5f80 | 830 | rel_dyn->add_local(object, r_sym, r_type, output_section, data_shndx, |
d61c6bd4 | 831 | reloc.get_r_offset()); |
436ca963 | 832 | } |
92e059d8 ILT |
833 | break; |
834 | ||
835 | case elfcpp::R_386_PC32: | |
836 | case elfcpp::R_386_PC16: | |
837 | case elfcpp::R_386_PC8: | |
838 | break; | |
839 | ||
df2efe71 ILT |
840 | case elfcpp::R_386_PLT32: |
841 | // Since we know this is a local symbol, we can handle this as a | |
842 | // PC32 reloc. | |
843 | break; | |
844 | ||
ead1e424 ILT |
845 | case elfcpp::R_386_GOTOFF: |
846 | case elfcpp::R_386_GOTPC: | |
847 | // We need a GOT section. | |
7e1edb90 | 848 | target->got_section(symtab, layout); |
ead1e424 ILT |
849 | break; |
850 | ||
1b64748b ILT |
851 | case elfcpp::R_386_GOT32: |
852 | { | |
853 | // The symbol requires a GOT entry. | |
854 | Output_data_got<32, false>* got = target->got_section(symtab, layout); | |
855 | unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); | |
856 | if (got->add_local(object, r_sym)) | |
857 | { | |
858 | // If we are generating a shared object, we need to add a | |
859 | // dynamic RELATIVE relocation for this symbol. | |
436ca963 | 860 | if (parameters->output_is_position_independent()) |
1b64748b ILT |
861 | { |
862 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); | |
863 | rel_dyn->add_local(object, 0, elfcpp::R_386_RELATIVE, | |
4f4c5f80 ILT |
864 | output_section, data_shndx, |
865 | reloc.get_r_offset()); | |
1b64748b ILT |
866 | } |
867 | } | |
868 | } | |
869 | break; | |
870 | ||
af6359d5 ILT |
871 | // These are relocations which should only be seen by the |
872 | // dynamic linker, and should never be seen here. | |
92e059d8 ILT |
873 | case elfcpp::R_386_COPY: |
874 | case elfcpp::R_386_GLOB_DAT: | |
875 | case elfcpp::R_386_JUMP_SLOT: | |
876 | case elfcpp::R_386_RELATIVE: | |
877 | case elfcpp::R_386_TLS_TPOFF: | |
878 | case elfcpp::R_386_TLS_DTPMOD32: | |
879 | case elfcpp::R_386_TLS_DTPOFF32: | |
880 | case elfcpp::R_386_TLS_TPOFF32: | |
881 | case elfcpp::R_386_TLS_DESC: | |
a0c4fb0a | 882 | gold_error(_("%s: unexpected reloc %u in object file"), |
75f2446e | 883 | object->name().c_str(), r_type); |
92e059d8 ILT |
884 | break; |
885 | ||
af6359d5 | 886 | // These are initial TLS relocs, which are expected when |
d61c17ea | 887 | // linking. |
56622147 ILT |
888 | case elfcpp::R_386_TLS_GD: // Global-dynamic |
889 | case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url) | |
890 | case elfcpp::R_386_TLS_DESC_CALL: | |
891 | case elfcpp::R_386_TLS_LDM: // Local-dynamic | |
892 | case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic | |
893 | case elfcpp::R_386_TLS_IE: // Initial-exec | |
92e059d8 | 894 | case elfcpp::R_386_TLS_IE_32: |
56622147 ILT |
895 | case elfcpp::R_386_TLS_GOTIE: |
896 | case elfcpp::R_386_TLS_LE: // Local-exec | |
92e059d8 | 897 | case elfcpp::R_386_TLS_LE_32: |
7e1edb90 | 898 | { |
80576242 | 899 | bool output_is_shared = parameters->output_is_shared(); |
af6359d5 ILT |
900 | const tls::Tls_optimization optimized_type |
901 | = Target_i386::optimize_tls_reloc(!output_is_shared, r_type); | |
7e1edb90 ILT |
902 | switch (r_type) |
903 | { | |
56622147 | 904 | case elfcpp::R_386_TLS_GD: // Global-dynamic |
07f397ab ILT |
905 | if (optimized_type == tls::TLSOPT_NONE) |
906 | { | |
907 | // Create a pair of GOT entries for the module index and | |
908 | // dtv-relative offset. | |
909 | Output_data_got<32, false>* got | |
910 | = target->got_section(symtab, layout); | |
911 | unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); | |
912 | if (got->add_local_tls(object, r_sym, true)) | |
913 | { | |
914 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); | |
915 | unsigned int got_off | |
916 | = object->local_tls_got_offset(r_sym, true); | |
917 | rel_dyn->add_local(object, r_sym, | |
918 | elfcpp::R_386_TLS_DTPMOD32, | |
919 | got, got_off); | |
920 | rel_dyn->add_local(object, r_sym, | |
921 | elfcpp::R_386_TLS_DTPOFF32, | |
922 | got, got_off + 4); | |
923 | } | |
924 | } | |
925 | else if (optimized_type != tls::TLSOPT_TO_LE) | |
926 | unsupported_reloc_local(object, r_type); | |
927 | break; | |
928 | ||
56622147 ILT |
929 | case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva) |
930 | case elfcpp::R_386_TLS_DESC_CALL: | |
07f397ab | 931 | unsupported_reloc_local(object, r_type); |
af6359d5 ILT |
932 | break; |
933 | ||
56622147 | 934 | case elfcpp::R_386_TLS_LDM: // Local-dynamic |
07f397ab ILT |
935 | if (optimized_type == tls::TLSOPT_NONE) |
936 | { | |
937 | // Create a GOT entry for the module index. | |
938 | Output_data_got<32, false>* got | |
939 | = target->got_section(symtab, layout); | |
940 | unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); | |
941 | if (got->add_local_tls(object, r_sym, false)) | |
942 | { | |
943 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); | |
944 | unsigned int got_off | |
945 | = object->local_tls_got_offset(r_sym, false); | |
946 | rel_dyn->add_local(object, r_sym, | |
947 | elfcpp::R_386_TLS_DTPMOD32, got, | |
948 | got_off); | |
949 | } | |
950 | } | |
951 | else if (optimized_type != tls::TLSOPT_TO_LE) | |
af6359d5 ILT |
952 | unsupported_reloc_local(object, r_type); |
953 | break; | |
954 | ||
56622147 | 955 | case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic |
46cf9fa2 ILT |
956 | break; |
957 | ||
56622147 ILT |
958 | case elfcpp::R_386_TLS_IE: // Initial-exec |
959 | case elfcpp::R_386_TLS_IE_32: | |
960 | case elfcpp::R_386_TLS_GOTIE: | |
07f397ab ILT |
961 | if (optimized_type == tls::TLSOPT_NONE) |
962 | { | |
963 | // Create a GOT entry for the tp-relative offset. | |
964 | Output_data_got<32, false>* got | |
965 | = target->got_section(symtab, layout); | |
966 | unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); | |
967 | if (got->add_local(object, r_sym)) | |
968 | { | |
969 | unsigned int dyn_r_type | |
970 | = (r_type == elfcpp::R_386_TLS_IE_32 | |
971 | ? elfcpp::R_386_TLS_TPOFF32 | |
972 | : elfcpp::R_386_TLS_TPOFF); | |
973 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); | |
974 | unsigned int got_off = object->local_got_offset(r_sym); | |
975 | rel_dyn->add_local(object, r_sym, dyn_r_type, got, | |
976 | got_off); | |
977 | } | |
978 | } | |
979 | else if (optimized_type != tls::TLSOPT_TO_LE) | |
af6359d5 | 980 | unsupported_reloc_local(object, r_type); |
7e1edb90 | 981 | break; |
af6359d5 | 982 | |
56622147 ILT |
983 | case elfcpp::R_386_TLS_LE: // Local-exec |
984 | case elfcpp::R_386_TLS_LE_32: | |
07f397ab ILT |
985 | if (output_is_shared) |
986 | unsupported_reloc_local(object, r_type); | |
56622147 ILT |
987 | break; |
988 | ||
af6359d5 ILT |
989 | default: |
990 | gold_unreachable(); | |
7e1edb90 ILT |
991 | } |
992 | } | |
92e059d8 ILT |
993 | break; |
994 | ||
92e059d8 ILT |
995 | case elfcpp::R_386_32PLT: |
996 | case elfcpp::R_386_TLS_GD_32: | |
997 | case elfcpp::R_386_TLS_GD_PUSH: | |
998 | case elfcpp::R_386_TLS_GD_CALL: | |
999 | case elfcpp::R_386_TLS_GD_POP: | |
1000 | case elfcpp::R_386_TLS_LDM_32: | |
1001 | case elfcpp::R_386_TLS_LDM_PUSH: | |
1002 | case elfcpp::R_386_TLS_LDM_CALL: | |
1003 | case elfcpp::R_386_TLS_LDM_POP: | |
1004 | case elfcpp::R_386_USED_BY_INTEL_200: | |
1005 | default: | |
af6359d5 | 1006 | unsupported_reloc_local(object, r_type); |
92e059d8 ILT |
1007 | break; |
1008 | } | |
1009 | } | |
1010 | ||
af6359d5 ILT |
1011 | // Report an unsupported relocation against a global symbol. |
1012 | ||
1013 | void | |
1014 | Target_i386::Scan::unsupported_reloc_global(Sized_relobj<32, false>* object, | |
1015 | unsigned int r_type, | |
1016 | Symbol* gsym) | |
1017 | { | |
75f2446e | 1018 | gold_error(_("%s: unsupported reloc %u against global symbol %s"), |
a2b1aa12 | 1019 | object->name().c_str(), r_type, gsym->demangled_name().c_str()); |
af6359d5 ILT |
1020 | } |
1021 | ||
92e059d8 ILT |
1022 | // Scan a relocation for a global symbol. |
1023 | ||
1024 | inline void | |
1025 | Target_i386::Scan::global(const General_options& options, | |
ead1e424 ILT |
1026 | Symbol_table* symtab, |
1027 | Layout* layout, | |
1028 | Target_i386* target, | |
f6ce93d6 | 1029 | Sized_relobj<32, false>* object, |
a3ad94ed | 1030 | unsigned int data_shndx, |
07f397ab | 1031 | Output_section* output_section, |
a3ad94ed ILT |
1032 | const elfcpp::Rel<32, false>& reloc, |
1033 | unsigned int r_type, | |
92e059d8 ILT |
1034 | Symbol* gsym) |
1035 | { | |
1036 | switch (r_type) | |
1037 | { | |
1038 | case elfcpp::R_386_NONE: | |
1039 | case elfcpp::R_386_GNU_VTINHERIT: | |
8462ae85 | 1040 | case elfcpp::R_386_GNU_VTENTRY: |
92e059d8 ILT |
1041 | break; |
1042 | ||
1043 | case elfcpp::R_386_32: | |
92e059d8 | 1044 | case elfcpp::R_386_16: |
92e059d8 | 1045 | case elfcpp::R_386_8: |
96f2030e | 1046 | { |
d61c6bd4 ILT |
1047 | // Make a PLT entry if necessary. |
1048 | if (gsym->needs_plt_entry()) | |
1049 | { | |
1050 | target->make_plt_entry(symtab, layout, gsym); | |
1051 | // Since this is not a PC-relative relocation, we may be | |
1052 | // taking the address of a function. In that case we need to | |
1053 | // set the entry in the dynamic symbol table to the address of | |
1054 | // the PLT entry. | |
1055 | if (gsym->is_from_dynobj()) | |
1056 | gsym->set_needs_dynsym_value(); | |
1057 | } | |
1058 | // Make a dynamic relocation if necessary. | |
1059 | if (gsym->needs_dynamic_reloc(true, false)) | |
1060 | { | |
1061 | if (target->may_need_copy_reloc(gsym)) | |
1062 | { | |
07f397ab | 1063 | target->copy_reloc(&options, symtab, layout, object, |
4f4c5f80 | 1064 | data_shndx, output_section, gsym, reloc); |
d61c6bd4 ILT |
1065 | } |
1066 | else if (r_type == elfcpp::R_386_32 | |
1067 | && gsym->can_use_relative_reloc(false)) | |
1068 | { | |
1069 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); | |
07f397ab | 1070 | rel_dyn->add_local(object, 0, elfcpp::R_386_RELATIVE, |
4f4c5f80 ILT |
1071 | output_section, data_shndx, |
1072 | reloc.get_r_offset()); | |
d61c6bd4 ILT |
1073 | } |
1074 | else | |
1075 | { | |
96f2030e | 1076 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
4f4c5f80 ILT |
1077 | rel_dyn->add_global(gsym, r_type, output_section, object, |
1078 | data_shndx, reloc.get_r_offset()); | |
d61c6bd4 ILT |
1079 | } |
1080 | } | |
1081 | } | |
1082 | break; | |
1083 | ||
1084 | case elfcpp::R_386_PC32: | |
1085 | case elfcpp::R_386_PC16: | |
1086 | case elfcpp::R_386_PC8: | |
1087 | { | |
1088 | // Make a PLT entry if necessary. | |
1089 | if (gsym->needs_plt_entry()) | |
1090 | target->make_plt_entry(symtab, layout, gsym); | |
1091 | // Make a dynamic relocation if necessary. | |
1092 | bool is_function_call = (gsym->type() == elfcpp::STT_FUNC); | |
1093 | if (gsym->needs_dynamic_reloc(false, is_function_call)) | |
96f2030e | 1094 | { |
d61c6bd4 ILT |
1095 | if (target->may_need_copy_reloc(gsym)) |
1096 | { | |
07f397ab | 1097 | target->copy_reloc(&options, symtab, layout, object, |
4f4c5f80 | 1098 | data_shndx, output_section, gsym, reloc); |
d61c6bd4 | 1099 | } |
86849f1f | 1100 | else |
d61c6bd4 ILT |
1101 | { |
1102 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); | |
4f4c5f80 ILT |
1103 | rel_dyn->add_global(gsym, r_type, output_section, object, |
1104 | data_shndx, reloc.get_r_offset()); | |
d61c6bd4 | 1105 | } |
96f2030e ILT |
1106 | } |
1107 | } | |
92e059d8 ILT |
1108 | break; |
1109 | ||
ead1e424 | 1110 | case elfcpp::R_386_GOT32: |
8462ae85 ILT |
1111 | { |
1112 | // The symbol requires a GOT entry. | |
7e1edb90 | 1113 | Output_data_got<32, false>* got = target->got_section(symtab, layout); |
8462ae85 ILT |
1114 | if (got->add_global(gsym)) |
1115 | { | |
1116 | // If this symbol is not fully resolved, we need to add a | |
1117 | // dynamic relocation for it. | |
7e1edb90 | 1118 | if (!gsym->final_value_is_known()) |
8462ae85 ILT |
1119 | { |
1120 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); | |
386c048c ILT |
1121 | if (gsym->is_from_dynobj() |
1122 | || gsym->is_preemptible()) | |
1123 | rel_dyn->add_global(gsym, elfcpp::R_386_GLOB_DAT, got, | |
1124 | gsym->got_offset()); | |
d61c6bd4 ILT |
1125 | else |
1126 | { | |
1127 | rel_dyn->add_local(object, 0, elfcpp::R_386_RELATIVE, | |
1128 | got, gsym->got_offset()); | |
1129 | // Make sure we write the link-time value to the GOT. | |
1130 | gsym->set_needs_value_in_got(); | |
1131 | } | |
8462ae85 ILT |
1132 | } |
1133 | } | |
1134 | } | |
ead1e424 ILT |
1135 | break; |
1136 | ||
1137 | case elfcpp::R_386_PLT32: | |
a3ad94ed ILT |
1138 | // If the symbol is fully resolved, this is just a PC32 reloc. |
1139 | // Otherwise we need a PLT entry. | |
7e1edb90 | 1140 | if (gsym->final_value_is_known()) |
ead1e424 | 1141 | break; |
436ca963 ILT |
1142 | // If building a shared library, we can also skip the PLT entry |
1143 | // if the symbol is defined in the output file and is protected | |
1144 | // or hidden. | |
1145 | if (gsym->is_defined() | |
1146 | && !gsym->is_from_dynobj() | |
1147 | && !gsym->is_preemptible()) | |
1148 | break; | |
7e1edb90 | 1149 | target->make_plt_entry(symtab, layout, gsym); |
ead1e424 ILT |
1150 | break; |
1151 | ||
1152 | case elfcpp::R_386_GOTOFF: | |
1153 | case elfcpp::R_386_GOTPC: | |
1154 | // We need a GOT section. | |
7e1edb90 | 1155 | target->got_section(symtab, layout); |
ead1e424 ILT |
1156 | break; |
1157 | ||
af6359d5 ILT |
1158 | // These are relocations which should only be seen by the |
1159 | // dynamic linker, and should never be seen here. | |
92e059d8 ILT |
1160 | case elfcpp::R_386_COPY: |
1161 | case elfcpp::R_386_GLOB_DAT: | |
1162 | case elfcpp::R_386_JUMP_SLOT: | |
1163 | case elfcpp::R_386_RELATIVE: | |
1164 | case elfcpp::R_386_TLS_TPOFF: | |
1165 | case elfcpp::R_386_TLS_DTPMOD32: | |
1166 | case elfcpp::R_386_TLS_DTPOFF32: | |
1167 | case elfcpp::R_386_TLS_TPOFF32: | |
1168 | case elfcpp::R_386_TLS_DESC: | |
75f2446e ILT |
1169 | gold_error(_("%s: unexpected reloc %u in object file"), |
1170 | object->name().c_str(), r_type); | |
92e059d8 ILT |
1171 | break; |
1172 | ||
d61c17ea ILT |
1173 | // These are initial tls relocs, which are expected when |
1174 | // linking. | |
56622147 ILT |
1175 | case elfcpp::R_386_TLS_GD: // Global-dynamic |
1176 | case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url) | |
1177 | case elfcpp::R_386_TLS_DESC_CALL: | |
1178 | case elfcpp::R_386_TLS_LDM: // Local-dynamic | |
1179 | case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic | |
1180 | case elfcpp::R_386_TLS_IE: // Initial-exec | |
92e059d8 | 1181 | case elfcpp::R_386_TLS_IE_32: |
56622147 ILT |
1182 | case elfcpp::R_386_TLS_GOTIE: |
1183 | case elfcpp::R_386_TLS_LE: // Local-exec | |
92e059d8 | 1184 | case elfcpp::R_386_TLS_LE_32: |
a3ad94ed | 1185 | { |
7e1edb90 | 1186 | const bool is_final = gsym->final_value_is_known(); |
af6359d5 ILT |
1187 | const tls::Tls_optimization optimized_type |
1188 | = Target_i386::optimize_tls_reloc(is_final, r_type); | |
a3ad94ed ILT |
1189 | switch (r_type) |
1190 | { | |
56622147 | 1191 | case elfcpp::R_386_TLS_GD: // Global-dynamic |
07f397ab ILT |
1192 | if (optimized_type == tls::TLSOPT_NONE) |
1193 | { | |
1194 | // Create a pair of GOT entries for the module index and | |
1195 | // dtv-relative offset. | |
1196 | Output_data_got<32, false>* got | |
1197 | = target->got_section(symtab, layout); | |
1198 | if (got->add_global_tls(gsym, true)) | |
1199 | { | |
1200 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); | |
1201 | unsigned int got_off = gsym->tls_got_offset(true); | |
1202 | rel_dyn->add_global(gsym, elfcpp::R_386_TLS_DTPMOD32, | |
1203 | got, got_off); | |
1204 | rel_dyn->add_global(gsym, elfcpp::R_386_TLS_DTPOFF32, | |
1205 | got, got_off + 4); | |
1206 | } | |
1207 | } | |
1208 | else if (optimized_type == tls::TLSOPT_TO_IE) | |
1209 | { | |
1210 | // Create a GOT entry for the tp-relative offset. | |
1211 | Output_data_got<32, false>* got | |
1212 | = target->got_section(symtab, layout); | |
1213 | if (got->add_global(gsym)) | |
1214 | { | |
1215 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); | |
1216 | unsigned int got_off = gsym->got_offset(); | |
1217 | rel_dyn->add_global(gsym, elfcpp::R_386_TLS_TPOFF32, | |
1218 | got, got_off); | |
1219 | } | |
1220 | } | |
1221 | else if (optimized_type != tls::TLSOPT_TO_LE) | |
1222 | unsupported_reloc_global(object, r_type, gsym); | |
1223 | break; | |
1224 | ||
56622147 ILT |
1225 | case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (~oliva url) |
1226 | case elfcpp::R_386_TLS_DESC_CALL: | |
07f397ab | 1227 | unsupported_reloc_global(object, r_type, gsym); |
af6359d5 ILT |
1228 | break; |
1229 | ||
56622147 | 1230 | case elfcpp::R_386_TLS_LDM: // Local-dynamic |
af6359d5 ILT |
1231 | // FIXME: If not relaxing to LE, we need to generate a |
1232 | // DTPMOD32 reloc. | |
07f397ab ILT |
1233 | if (optimized_type == tls::TLSOPT_NONE) |
1234 | { | |
1235 | // Create a GOT entry for the module index. | |
1236 | Output_data_got<32, false>* got | |
1237 | = target->got_section(symtab, layout); | |
1238 | if (got->add_global_tls(gsym, false)) | |
1239 | { | |
1240 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); | |
1241 | unsigned int got_off = gsym->tls_got_offset(false); | |
1242 | rel_dyn->add_global(gsym, elfcpp::R_386_TLS_DTPMOD32, | |
1243 | got, got_off); | |
1244 | } | |
1245 | } | |
1246 | else if (optimized_type != tls::TLSOPT_TO_LE) | |
af6359d5 ILT |
1247 | unsupported_reloc_global(object, r_type, gsym); |
1248 | break; | |
1249 | ||
56622147 | 1250 | case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic |
46cf9fa2 ILT |
1251 | break; |
1252 | ||
56622147 ILT |
1253 | case elfcpp::R_386_TLS_IE: // Initial-exec |
1254 | case elfcpp::R_386_TLS_IE_32: | |
1255 | case elfcpp::R_386_TLS_GOTIE: | |
07f397ab ILT |
1256 | if (optimized_type == tls::TLSOPT_NONE) |
1257 | { | |
1258 | // Create a GOT entry for the tp-relative offset. | |
1259 | Output_data_got<32, false>* got | |
1260 | = target->got_section(symtab, layout); | |
1261 | if (got->add_global(gsym)) | |
1262 | { | |
1263 | unsigned int dyn_r_type | |
1264 | = (r_type == elfcpp::R_386_TLS_IE_32 | |
1265 | ? elfcpp::R_386_TLS_TPOFF32 | |
1266 | : elfcpp::R_386_TLS_TPOFF); | |
1267 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); | |
1268 | unsigned int got_off = gsym->got_offset(); | |
1269 | rel_dyn->add_global(gsym, dyn_r_type, got, got_off); | |
1270 | } | |
1271 | } | |
1272 | else if (optimized_type != tls::TLSOPT_TO_LE) | |
af6359d5 | 1273 | unsupported_reloc_global(object, r_type, gsym); |
a3ad94ed | 1274 | break; |
af6359d5 | 1275 | |
56622147 ILT |
1276 | case elfcpp::R_386_TLS_LE: // Local-exec |
1277 | case elfcpp::R_386_TLS_LE_32: | |
07f397ab ILT |
1278 | if (parameters->output_is_shared()) |
1279 | unsupported_reloc_global(object, r_type, gsym); | |
56622147 ILT |
1280 | break; |
1281 | ||
af6359d5 ILT |
1282 | default: |
1283 | gold_unreachable(); | |
a3ad94ed ILT |
1284 | } |
1285 | } | |
92e059d8 ILT |
1286 | break; |
1287 | ||
92e059d8 ILT |
1288 | case elfcpp::R_386_32PLT: |
1289 | case elfcpp::R_386_TLS_GD_32: | |
1290 | case elfcpp::R_386_TLS_GD_PUSH: | |
1291 | case elfcpp::R_386_TLS_GD_CALL: | |
1292 | case elfcpp::R_386_TLS_GD_POP: | |
1293 | case elfcpp::R_386_TLS_LDM_32: | |
1294 | case elfcpp::R_386_TLS_LDM_PUSH: | |
1295 | case elfcpp::R_386_TLS_LDM_CALL: | |
1296 | case elfcpp::R_386_TLS_LDM_POP: | |
1297 | case elfcpp::R_386_USED_BY_INTEL_200: | |
1298 | default: | |
af6359d5 | 1299 | unsupported_reloc_global(object, r_type, gsym); |
92e059d8 ILT |
1300 | break; |
1301 | } | |
1302 | } | |
1303 | ||
1304 | // Scan relocations for a section. | |
1305 | ||
1306 | void | |
1307 | Target_i386::scan_relocs(const General_options& options, | |
1308 | Symbol_table* symtab, | |
ead1e424 | 1309 | Layout* layout, |
f6ce93d6 | 1310 | Sized_relobj<32, false>* object, |
a3ad94ed | 1311 | unsigned int data_shndx, |
92e059d8 ILT |
1312 | unsigned int sh_type, |
1313 | const unsigned char* prelocs, | |
1314 | size_t reloc_count, | |
730cdc88 ILT |
1315 | Output_section* output_section, |
1316 | bool needs_special_offset_handling, | |
92e059d8 | 1317 | size_t local_symbol_count, |
730cdc88 | 1318 | const unsigned char* plocal_symbols) |
92e059d8 ILT |
1319 | { |
1320 | if (sh_type == elfcpp::SHT_RELA) | |
1321 | { | |
75f2446e ILT |
1322 | gold_error(_("%s: unsupported RELA reloc section"), |
1323 | object->name().c_str()); | |
1324 | return; | |
92e059d8 ILT |
1325 | } |
1326 | ||
ead1e424 ILT |
1327 | gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL, |
1328 | Target_i386::Scan>( | |
92e059d8 ILT |
1329 | options, |
1330 | symtab, | |
ead1e424 ILT |
1331 | layout, |
1332 | this, | |
92e059d8 | 1333 | object, |
a3ad94ed | 1334 | data_shndx, |
92e059d8 ILT |
1335 | prelocs, |
1336 | reloc_count, | |
730cdc88 ILT |
1337 | output_section, |
1338 | needs_special_offset_handling, | |
92e059d8 | 1339 | local_symbol_count, |
730cdc88 | 1340 | plocal_symbols); |
92e059d8 ILT |
1341 | } |
1342 | ||
16649710 | 1343 | // Finalize the sections. |
5a6f7e2d ILT |
1344 | |
1345 | void | |
7e1edb90 | 1346 | Target_i386::do_finalize_sections(Layout* layout) |
5a6f7e2d | 1347 | { |
16649710 ILT |
1348 | // Fill in some more dynamic tags. |
1349 | Output_data_dynamic* const odyn = layout->dynamic_data(); | |
1350 | if (odyn != NULL) | |
1351 | { | |
1352 | if (this->got_plt_ != NULL) | |
1353 | odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_); | |
1354 | ||
1355 | if (this->plt_ != NULL) | |
1356 | { | |
1357 | const Output_data* od = this->plt_->rel_plt(); | |
1358 | odyn->add_section_size(elfcpp::DT_PLTRELSZ, od); | |
1359 | odyn->add_section_address(elfcpp::DT_JMPREL, od); | |
1360 | odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_REL); | |
1361 | } | |
1362 | ||
1363 | if (this->rel_dyn_ != NULL) | |
1364 | { | |
1365 | const Output_data* od = this->rel_dyn_; | |
1366 | odyn->add_section_address(elfcpp::DT_REL, od); | |
1367 | odyn->add_section_size(elfcpp::DT_RELSZ, od); | |
1368 | odyn->add_constant(elfcpp::DT_RELENT, | |
1369 | elfcpp::Elf_sizes<32>::rel_size); | |
1370 | } | |
1371 | ||
7e1edb90 | 1372 | if (!parameters->output_is_shared()) |
16649710 ILT |
1373 | { |
1374 | // The value of the DT_DEBUG tag is filled in by the dynamic | |
1375 | // linker at run time, and used by the debugger. | |
1376 | odyn->add_constant(elfcpp::DT_DEBUG, 0); | |
1377 | } | |
1378 | } | |
1379 | ||
1380 | // Emit any relocs we saved in an attempt to avoid generating COPY | |
1381 | // relocs. | |
5a6f7e2d ILT |
1382 | if (this->copy_relocs_ == NULL) |
1383 | return; | |
1384 | if (this->copy_relocs_->any_to_emit()) | |
1385 | { | |
1386 | Reloc_section* rel_dyn = this->rel_dyn_section(layout); | |
1387 | this->copy_relocs_->emit(rel_dyn); | |
1388 | } | |
1389 | delete this->copy_relocs_; | |
1390 | this->copy_relocs_ = NULL; | |
1391 | } | |
1392 | ||
86849f1f ILT |
1393 | // Return whether a direct absolute static relocation needs to be applied. |
1394 | // In cases where Scan::local() or Scan::global() has created | |
1395 | // a dynamic relocation other than R_386_RELATIVE, the addend | |
1396 | // of the relocation is carried in the data, and we must not | |
1397 | // apply the static relocation. | |
1398 | ||
1399 | inline bool | |
1400 | Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol<32>* gsym, | |
d61c6bd4 ILT |
1401 | bool is_absolute_ref, |
1402 | bool is_function_call, | |
86849f1f ILT |
1403 | bool is_32bit) |
1404 | { | |
d61c6bd4 ILT |
1405 | // For local symbols, we will have created a non-RELATIVE dynamic |
1406 | // relocation only if (a) the output is position independent, | |
1407 | // (b) the relocation is absolute (not pc- or segment-relative), and | |
1408 | // (c) the relocation is not 32 bits wide. | |
86849f1f | 1409 | if (gsym == NULL) |
d61c6bd4 ILT |
1410 | return !(parameters->output_is_position_independent() |
1411 | && is_absolute_ref | |
1412 | && !is_32bit); | |
86849f1f | 1413 | |
d61c6bd4 ILT |
1414 | // For global symbols, we use the same helper routines used in the scan pass. |
1415 | return !(gsym->needs_dynamic_reloc(is_absolute_ref, is_function_call) | |
1416 | && !gsym->can_use_relative_reloc(is_function_call)); | |
86849f1f ILT |
1417 | } |
1418 | ||
61ba1cf9 ILT |
1419 | // Perform a relocation. |
1420 | ||
ead1e424 | 1421 | inline bool |
92e059d8 | 1422 | Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo, |
ead1e424 | 1423 | Target_i386* target, |
92e059d8 ILT |
1424 | size_t relnum, |
1425 | const elfcpp::Rel<32, false>& rel, | |
1426 | unsigned int r_type, | |
c06b7b0b | 1427 | const Sized_symbol<32>* gsym, |
b8e6aad9 | 1428 | const Symbol_value<32>* psymval, |
92e059d8 ILT |
1429 | unsigned char* view, |
1430 | elfcpp::Elf_types<32>::Elf_Addr address, | |
1431 | off_t view_size) | |
61ba1cf9 | 1432 | { |
ead1e424 ILT |
1433 | if (this->skip_call_tls_get_addr_) |
1434 | { | |
1435 | if (r_type != elfcpp::R_386_PLT32 | |
1436 | || gsym == NULL | |
1437 | || strcmp(gsym->name(), "___tls_get_addr") != 0) | |
75f2446e ILT |
1438 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
1439 | _("missing expected TLS relocation")); | |
1440 | else | |
ead1e424 | 1441 | { |
75f2446e ILT |
1442 | this->skip_call_tls_get_addr_ = false; |
1443 | return false; | |
ead1e424 | 1444 | } |
ead1e424 ILT |
1445 | } |
1446 | ||
a3ad94ed | 1447 | // Pick the value to use for symbols defined in shared objects. |
b8e6aad9 | 1448 | Symbol_value<32> symval; |
436ca963 ILT |
1449 | if (gsym != NULL |
1450 | && (gsym->is_from_dynobj() | |
1451 | || (parameters->output_is_shared() | |
1452 | && gsym->is_preemptible())) | |
1453 | && gsym->has_plt_offset()) | |
a3ad94ed | 1454 | { |
b8e6aad9 ILT |
1455 | symval.set_output_value(target->plt_section()->address() |
1456 | + gsym->plt_offset()); | |
1457 | psymval = &symval; | |
a3ad94ed ILT |
1458 | } |
1459 | ||
b8e6aad9 ILT |
1460 | const Sized_relobj<32, false>* object = relinfo->object; |
1461 | ||
1b64748b | 1462 | // Get the GOT offset if needed. |
96f2030e ILT |
1463 | // The GOT pointer points to the end of the GOT section. |
1464 | // We need to subtract the size of the GOT section to get | |
1465 | // the actual offset to use in the relocation. | |
1b64748b ILT |
1466 | bool have_got_offset = false; |
1467 | unsigned int got_offset = 0; | |
1468 | switch (r_type) | |
1469 | { | |
1470 | case elfcpp::R_386_GOT32: | |
1471 | if (gsym != NULL) | |
1472 | { | |
1473 | gold_assert(gsym->has_got_offset()); | |
96f2030e | 1474 | got_offset = gsym->got_offset() - target->got_size(); |
1b64748b ILT |
1475 | } |
1476 | else | |
1477 | { | |
1478 | unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info()); | |
07f397ab | 1479 | gold_assert(object->local_has_got_offset(r_sym)); |
96f2030e | 1480 | got_offset = object->local_got_offset(r_sym) - target->got_size(); |
1b64748b ILT |
1481 | } |
1482 | have_got_offset = true; | |
1483 | break; | |
1484 | ||
1485 | default: | |
1486 | break; | |
1487 | } | |
1488 | ||
61ba1cf9 ILT |
1489 | switch (r_type) |
1490 | { | |
1491 | case elfcpp::R_386_NONE: | |
92e059d8 ILT |
1492 | case elfcpp::R_386_GNU_VTINHERIT: |
1493 | case elfcpp::R_386_GNU_VTENTRY: | |
61ba1cf9 ILT |
1494 | break; |
1495 | ||
1496 | case elfcpp::R_386_32: | |
d61c6bd4 | 1497 | if (should_apply_static_reloc(gsym, true, false, true)) |
86849f1f | 1498 | Relocate_functions<32, false>::rel32(view, object, psymval); |
61ba1cf9 ILT |
1499 | break; |
1500 | ||
1501 | case elfcpp::R_386_PC32: | |
d61c6bd4 ILT |
1502 | { |
1503 | bool is_function_call = (gsym != NULL | |
1504 | && gsym->type() == elfcpp::STT_FUNC); | |
1505 | if (should_apply_static_reloc(gsym, false, is_function_call, true)) | |
1506 | Relocate_functions<32, false>::pcrel32(view, object, psymval, address); | |
1507 | } | |
92e059d8 ILT |
1508 | break; |
1509 | ||
1510 | case elfcpp::R_386_16: | |
d61c6bd4 | 1511 | if (should_apply_static_reloc(gsym, true, false, false)) |
86849f1f | 1512 | Relocate_functions<32, false>::rel16(view, object, psymval); |
92e059d8 ILT |
1513 | break; |
1514 | ||
1515 | case elfcpp::R_386_PC16: | |
d61c6bd4 ILT |
1516 | { |
1517 | bool is_function_call = (gsym != NULL | |
1518 | && gsym->type() == elfcpp::STT_FUNC); | |
1519 | if (should_apply_static_reloc(gsym, false, is_function_call, false)) | |
1520 | Relocate_functions<32, false>::pcrel32(view, object, psymval, address); | |
1521 | } | |
61ba1cf9 ILT |
1522 | break; |
1523 | ||
92e059d8 | 1524 | case elfcpp::R_386_8: |
d61c6bd4 | 1525 | if (should_apply_static_reloc(gsym, true, false, false)) |
86849f1f | 1526 | Relocate_functions<32, false>::rel8(view, object, psymval); |
92e059d8 ILT |
1527 | break; |
1528 | ||
1529 | case elfcpp::R_386_PC8: | |
d61c6bd4 ILT |
1530 | { |
1531 | bool is_function_call = (gsym != NULL | |
1532 | && gsym->type() == elfcpp::STT_FUNC); | |
1533 | if (should_apply_static_reloc(gsym, false, is_function_call, false)) | |
1534 | Relocate_functions<32, false>::pcrel32(view, object, psymval, address); | |
1535 | } | |
92e059d8 ILT |
1536 | break; |
1537 | ||
ead1e424 | 1538 | case elfcpp::R_386_PLT32: |
df2efe71 ILT |
1539 | gold_assert(gsym == NULL |
1540 | || gsym->has_plt_offset() | |
1541 | || gsym->final_value_is_known()); | |
b8e6aad9 | 1542 | Relocate_functions<32, false>::pcrel32(view, object, psymval, address); |
ead1e424 ILT |
1543 | break; |
1544 | ||
1545 | case elfcpp::R_386_GOT32: | |
1b64748b ILT |
1546 | gold_assert(have_got_offset); |
1547 | Relocate_functions<32, false>::rel32(view, got_offset); | |
ead1e424 ILT |
1548 | break; |
1549 | ||
1550 | case elfcpp::R_386_GOTOFF: | |
b8e6aad9 ILT |
1551 | { |
1552 | elfcpp::Elf_types<32>::Elf_Addr value; | |
1553 | value = (psymval->value(object, 0) | |
96f2030e | 1554 | - target->got_plt_section()->address()); |
b8e6aad9 ILT |
1555 | Relocate_functions<32, false>::rel32(view, value); |
1556 | } | |
ead1e424 ILT |
1557 | break; |
1558 | ||
1559 | case elfcpp::R_386_GOTPC: | |
b8e6aad9 ILT |
1560 | { |
1561 | elfcpp::Elf_types<32>::Elf_Addr value; | |
96f2030e | 1562 | value = target->got_plt_section()->address(); |
b8e6aad9 ILT |
1563 | Relocate_functions<32, false>::pcrel32(view, value, address); |
1564 | } | |
ead1e424 ILT |
1565 | break; |
1566 | ||
92e059d8 ILT |
1567 | case elfcpp::R_386_COPY: |
1568 | case elfcpp::R_386_GLOB_DAT: | |
1569 | case elfcpp::R_386_JUMP_SLOT: | |
1570 | case elfcpp::R_386_RELATIVE: | |
d61c17ea ILT |
1571 | // These are outstanding tls relocs, which are unexpected when |
1572 | // linking. | |
92e059d8 ILT |
1573 | case elfcpp::R_386_TLS_TPOFF: |
1574 | case elfcpp::R_386_TLS_DTPMOD32: | |
1575 | case elfcpp::R_386_TLS_DTPOFF32: | |
1576 | case elfcpp::R_386_TLS_TPOFF32: | |
1577 | case elfcpp::R_386_TLS_DESC: | |
75f2446e ILT |
1578 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
1579 | _("unexpected reloc %u in object file"), | |
1580 | r_type); | |
92e059d8 ILT |
1581 | break; |
1582 | ||
d61c17ea ILT |
1583 | // These are initial tls relocs, which are expected when |
1584 | // linking. | |
56622147 ILT |
1585 | case elfcpp::R_386_TLS_GD: // Global-dynamic |
1586 | case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url) | |
1587 | case elfcpp::R_386_TLS_DESC_CALL: | |
1588 | case elfcpp::R_386_TLS_LDM: // Local-dynamic | |
1589 | case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic | |
1590 | case elfcpp::R_386_TLS_IE: // Initial-exec | |
92e059d8 | 1591 | case elfcpp::R_386_TLS_IE_32: |
56622147 ILT |
1592 | case elfcpp::R_386_TLS_GOTIE: |
1593 | case elfcpp::R_386_TLS_LE: // Local-exec | |
92e059d8 | 1594 | case elfcpp::R_386_TLS_LE_32: |
07f397ab ILT |
1595 | this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval, |
1596 | view, address, view_size); | |
92e059d8 ILT |
1597 | break; |
1598 | ||
92e059d8 ILT |
1599 | case elfcpp::R_386_32PLT: |
1600 | case elfcpp::R_386_TLS_GD_32: | |
1601 | case elfcpp::R_386_TLS_GD_PUSH: | |
1602 | case elfcpp::R_386_TLS_GD_CALL: | |
1603 | case elfcpp::R_386_TLS_GD_POP: | |
1604 | case elfcpp::R_386_TLS_LDM_32: | |
1605 | case elfcpp::R_386_TLS_LDM_PUSH: | |
1606 | case elfcpp::R_386_TLS_LDM_CALL: | |
1607 | case elfcpp::R_386_TLS_LDM_POP: | |
1608 | case elfcpp::R_386_USED_BY_INTEL_200: | |
61ba1cf9 | 1609 | default: |
75f2446e ILT |
1610 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
1611 | _("unsupported reloc %u"), | |
1612 | r_type); | |
92e059d8 ILT |
1613 | break; |
1614 | } | |
ead1e424 ILT |
1615 | |
1616 | return true; | |
92e059d8 ILT |
1617 | } |
1618 | ||
1619 | // Perform a TLS relocation. | |
1620 | ||
1621 | inline void | |
1622 | Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo, | |
07f397ab | 1623 | Target_i386* target, |
92e059d8 ILT |
1624 | size_t relnum, |
1625 | const elfcpp::Rel<32, false>& rel, | |
1626 | unsigned int r_type, | |
c06b7b0b | 1627 | const Sized_symbol<32>* gsym, |
b8e6aad9 | 1628 | const Symbol_value<32>* psymval, |
92e059d8 ILT |
1629 | unsigned char* view, |
1630 | elfcpp::Elf_types<32>::Elf_Addr, | |
1631 | off_t view_size) | |
1632 | { | |
1633 | Output_segment* tls_segment = relinfo->layout->tls_segment(); | |
92e059d8 | 1634 | |
07f397ab ILT |
1635 | const Sized_relobj<32, false>* object = relinfo->object; |
1636 | ||
1637 | elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0); | |
b8e6aad9 | 1638 | |
a3ad94ed | 1639 | const bool is_final = (gsym == NULL |
436ca963 | 1640 | ? !parameters->output_is_position_independent() |
7e1edb90 | 1641 | : gsym->final_value_is_known()); |
af6359d5 ILT |
1642 | const tls::Tls_optimization optimized_type |
1643 | = Target_i386::optimize_tls_reloc(is_final, r_type); | |
92e059d8 ILT |
1644 | switch (r_type) |
1645 | { | |
56622147 | 1646 | case elfcpp::R_386_TLS_GD: // Global-dynamic |
af6359d5 | 1647 | if (optimized_type == tls::TLSOPT_TO_LE) |
92e059d8 | 1648 | { |
07f397ab | 1649 | gold_assert(tls_segment != NULL); |
56622147 ILT |
1650 | this->tls_gd_to_le(relinfo, relnum, tls_segment, |
1651 | rel, r_type, value, view, | |
1652 | view_size); | |
92e059d8 ILT |
1653 | break; |
1654 | } | |
07f397ab ILT |
1655 | else |
1656 | { | |
1657 | unsigned int got_offset; | |
1658 | if (gsym != NULL) | |
1659 | { | |
1660 | gold_assert(gsym->has_tls_got_offset(true)); | |
1661 | got_offset = gsym->tls_got_offset(true) - target->got_size(); | |
1662 | } | |
1663 | else | |
1664 | { | |
1665 | unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info()); | |
1666 | gold_assert(object->local_has_tls_got_offset(r_sym, true)); | |
1667 | got_offset = (object->local_tls_got_offset(r_sym, true) | |
1668 | - target->got_size()); | |
1669 | } | |
1670 | if (optimized_type == tls::TLSOPT_TO_IE) | |
1671 | { | |
1672 | gold_assert(tls_segment != NULL); | |
1673 | this->tls_gd_to_ie(relinfo, relnum, tls_segment, | |
1674 | rel, r_type, got_offset, view, | |
1675 | view_size); | |
1676 | break; | |
1677 | } | |
1678 | else if (optimized_type == tls::TLSOPT_NONE) | |
1679 | { | |
1680 | // Relocate the field with the offset of the pair of GOT | |
1681 | // entries. | |
1682 | Relocate_functions<32, false>::rel32(view, got_offset); | |
1683 | break; | |
1684 | } | |
1685 | } | |
75f2446e ILT |
1686 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
1687 | _("unsupported reloc %u"), | |
1688 | r_type); | |
92e059d8 ILT |
1689 | break; |
1690 | ||
56622147 ILT |
1691 | case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url) |
1692 | case elfcpp::R_386_TLS_DESC_CALL: | |
75f2446e ILT |
1693 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
1694 | _("unsupported reloc %u"), | |
1695 | r_type); | |
ead1e424 ILT |
1696 | break; |
1697 | ||
56622147 | 1698 | case elfcpp::R_386_TLS_LDM: // Local-dynamic |
46cf9fa2 ILT |
1699 | if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN) |
1700 | { | |
75f2446e ILT |
1701 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
1702 | _("both SUN and GNU model " | |
1703 | "TLS relocations")); | |
1704 | break; | |
46cf9fa2 ILT |
1705 | } |
1706 | this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU; | |
af6359d5 | 1707 | if (optimized_type == tls::TLSOPT_TO_LE) |
46cf9fa2 | 1708 | { |
07f397ab | 1709 | gold_assert(tls_segment != NULL); |
46cf9fa2 ILT |
1710 | this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, r_type, |
1711 | value, view, view_size); | |
1712 | break; | |
1713 | } | |
07f397ab ILT |
1714 | else if (optimized_type == tls::TLSOPT_NONE) |
1715 | { | |
1716 | // Relocate the field with the offset of the GOT entry for | |
1717 | // the module index. | |
1718 | unsigned int got_offset; | |
1719 | if (gsym != NULL) | |
1720 | { | |
1721 | gold_assert(gsym->has_tls_got_offset(false)); | |
1722 | got_offset = gsym->tls_got_offset(false) - target->got_size(); | |
1723 | } | |
1724 | else | |
1725 | { | |
1726 | unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info()); | |
1727 | gold_assert(object->local_has_tls_got_offset(r_sym, false)); | |
1728 | got_offset = (object->local_tls_got_offset(r_sym, false) | |
1729 | - target->got_size()); | |
1730 | } | |
1731 | Relocate_functions<32, false>::rel32(view, got_offset); | |
1732 | break; | |
1733 | } | |
75f2446e ILT |
1734 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
1735 | _("unsupported reloc %u"), | |
1736 | r_type); | |
46cf9fa2 ILT |
1737 | break; |
1738 | ||
56622147 | 1739 | case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic |
46cf9fa2 ILT |
1740 | // This reloc can appear in debugging sections, in which case we |
1741 | // won't see the TLS_LDM reloc. The local_dynamic_type field | |
1742 | // tells us this. | |
07f397ab | 1743 | gold_assert(tls_segment != NULL); |
af6359d5 | 1744 | if (optimized_type != tls::TLSOPT_TO_LE |
46cf9fa2 ILT |
1745 | || this->local_dynamic_type_ == LOCAL_DYNAMIC_NONE) |
1746 | value = value - tls_segment->vaddr(); | |
1747 | else if (this->local_dynamic_type_ == LOCAL_DYNAMIC_GNU) | |
1748 | value = value - (tls_segment->vaddr() + tls_segment->memsz()); | |
1749 | else | |
1750 | value = tls_segment->vaddr() + tls_segment->memsz() - value; | |
1751 | Relocate_functions<32, false>::rel32(view, value); | |
1752 | break; | |
1753 | ||
56622147 ILT |
1754 | case elfcpp::R_386_TLS_IE: // Initial-exec |
1755 | case elfcpp::R_386_TLS_GOTIE: | |
1756 | case elfcpp::R_386_TLS_IE_32: | |
1757 | if (optimized_type == tls::TLSOPT_TO_LE) | |
1758 | { | |
07f397ab | 1759 | gold_assert(tls_segment != NULL); |
56622147 ILT |
1760 | Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment, |
1761 | rel, r_type, value, view, | |
1762 | view_size); | |
1763 | break; | |
1764 | } | |
07f397ab ILT |
1765 | else if (optimized_type == tls::TLSOPT_NONE) |
1766 | { | |
1767 | // Relocate the field with the offset of the GOT entry for | |
1768 | // the tp-relative offset of the symbol. | |
1769 | unsigned int got_offset; | |
1770 | if (gsym != NULL) | |
1771 | { | |
1772 | gold_assert(gsym->has_got_offset()); | |
1773 | got_offset = gsym->got_offset(); | |
1774 | } | |
1775 | else | |
1776 | { | |
1777 | unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info()); | |
1778 | gold_assert(object->local_has_got_offset(r_sym)); | |
1779 | got_offset = object->local_got_offset(r_sym); | |
1780 | } | |
1781 | // For the R_386_TLS_IE relocation, we need to apply the | |
1782 | // absolute address of the GOT entry. | |
1783 | if (r_type == elfcpp::R_386_TLS_IE) | |
1784 | got_offset += target->got_plt_section()->address(); | |
1785 | // All GOT offsets are relative to the end of the GOT. | |
1786 | got_offset -= target->got_size(); | |
1787 | Relocate_functions<32, false>::rel32(view, got_offset); | |
1788 | break; | |
1789 | } | |
75f2446e ILT |
1790 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
1791 | _("unsupported reloc %u"), | |
1792 | r_type); | |
92e059d8 | 1793 | break; |
92e059d8 | 1794 | |
56622147 | 1795 | case elfcpp::R_386_TLS_LE: // Local-exec |
07f397ab | 1796 | gold_assert(tls_segment != NULL); |
56622147 ILT |
1797 | value = value - (tls_segment->vaddr() + tls_segment->memsz()); |
1798 | Relocate_functions<32, false>::rel32(view, value); | |
1799 | break; | |
92e059d8 | 1800 | |
56622147 | 1801 | case elfcpp::R_386_TLS_LE_32: |
07f397ab | 1802 | gold_assert(tls_segment != NULL); |
56622147 ILT |
1803 | value = tls_segment->vaddr() + tls_segment->memsz() - value; |
1804 | Relocate_functions<32, false>::rel32(view, value); | |
1805 | break; | |
92e059d8 | 1806 | } |
92e059d8 ILT |
1807 | } |
1808 | ||
e041f13d | 1809 | // Do a relocation in which we convert a TLS General-Dynamic to a |
ead1e424 ILT |
1810 | // Local-Exec. |
1811 | ||
1812 | inline void | |
1813 | Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo, | |
1814 | size_t relnum, | |
1815 | Output_segment* tls_segment, | |
1816 | const elfcpp::Rel<32, false>& rel, | |
1817 | unsigned int, | |
1818 | elfcpp::Elf_types<32>::Elf_Addr value, | |
1819 | unsigned char* view, | |
1820 | off_t view_size) | |
1821 | { | |
1822 | // leal foo(,%reg,1),%eax; call ___tls_get_addr | |
46cf9fa2 | 1823 | // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax |
ead1e424 ILT |
1824 | // leal foo(%reg),%eax; call ___tls_get_addr |
1825 | // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax | |
1826 | ||
af6359d5 ILT |
1827 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2); |
1828 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9); | |
ead1e424 ILT |
1829 | |
1830 | unsigned char op1 = view[-1]; | |
1831 | unsigned char op2 = view[-2]; | |
1832 | ||
af6359d5 ILT |
1833 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
1834 | op2 == 0x8d || op2 == 0x04); | |
1835 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8); | |
ead1e424 ILT |
1836 | |
1837 | int roff = 5; | |
1838 | ||
1839 | if (op2 == 0x04) | |
1840 | { | |
af6359d5 ILT |
1841 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3); |
1842 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d); | |
1843 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), | |
1844 | ((op1 & 0xc7) == 0x05 && op1 != (4 << 3))); | |
ead1e424 ILT |
1845 | memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12); |
1846 | } | |
1847 | else | |
1848 | { | |
af6359d5 ILT |
1849 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
1850 | (op1 & 0xf8) == 0x80 && (op1 & 7) != 4); | |
d61c17ea ILT |
1851 | if (static_cast<off_t>(rel.get_r_offset() + 9) < view_size |
1852 | && view[9] == 0x90) | |
ead1e424 ILT |
1853 | { |
1854 | // There is a trailing nop. Use the size byte subl. | |
1855 | memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12); | |
1856 | roff = 6; | |
1857 | } | |
1858 | else | |
1859 | { | |
1860 | // Use the five byte subl. | |
1861 | memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11); | |
1862 | } | |
1863 | } | |
1864 | ||
1865 | value = tls_segment->vaddr() + tls_segment->memsz() - value; | |
1866 | Relocate_functions<32, false>::rel32(view + roff, value); | |
1867 | ||
1868 | // The next reloc should be a PLT32 reloc against __tls_get_addr. | |
1869 | // We can skip it. | |
1870 | this->skip_call_tls_get_addr_ = true; | |
1871 | } | |
1872 | ||
07f397ab ILT |
1873 | // Do a relocation in which we convert a TLS General-Dynamic to a |
1874 | // Initial-Exec. | |
1875 | ||
1876 | inline void | |
1877 | Target_i386::Relocate::tls_gd_to_ie(const Relocate_info<32, false>* relinfo, | |
1878 | size_t relnum, | |
1879 | Output_segment* tls_segment, | |
1880 | const elfcpp::Rel<32, false>& rel, | |
1881 | unsigned int, | |
1882 | elfcpp::Elf_types<32>::Elf_Addr value, | |
1883 | unsigned char* view, | |
1884 | off_t view_size) | |
1885 | { | |
1886 | // leal foo(,%ebx,1),%eax; call ___tls_get_addr | |
1887 | // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax | |
1888 | ||
1889 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2); | |
1890 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9); | |
1891 | ||
1892 | unsigned char op1 = view[-1]; | |
1893 | unsigned char op2 = view[-2]; | |
1894 | ||
1895 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), | |
1896 | op2 == 0x8d || op2 == 0x04); | |
1897 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8); | |
1898 | ||
1899 | int roff = 5; | |
1900 | ||
1901 | // FIXME: For now, support only one form. | |
1902 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), | |
1903 | op1 == 0x8d && op2 == 0x04); | |
1904 | ||
1905 | if (op2 == 0x04) | |
1906 | { | |
1907 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3); | |
1908 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d); | |
1909 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), | |
1910 | ((op1 & 0xc7) == 0x05 && op1 != (4 << 3))); | |
1911 | memcpy(view - 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12); | |
1912 | } | |
1913 | else | |
1914 | { | |
1915 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), | |
1916 | (op1 & 0xf8) == 0x80 && (op1 & 7) != 4); | |
1917 | if (static_cast<off_t>(rel.get_r_offset() + 9) < view_size | |
1918 | && view[9] == 0x90) | |
1919 | { | |
1920 | // FIXME: This is not the right instruction sequence. | |
1921 | // There is a trailing nop. Use the size byte subl. | |
1922 | memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12); | |
1923 | roff = 6; | |
1924 | } | |
1925 | else | |
1926 | { | |
1927 | // FIXME: This is not the right instruction sequence. | |
1928 | // Use the five byte subl. | |
1929 | memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11); | |
1930 | } | |
1931 | } | |
1932 | ||
1933 | value = tls_segment->vaddr() + tls_segment->memsz() - value; | |
1934 | Relocate_functions<32, false>::rel32(view + roff, value); | |
1935 | ||
1936 | // The next reloc should be a PLT32 reloc against __tls_get_addr. | |
1937 | // We can skip it. | |
1938 | this->skip_call_tls_get_addr_ = true; | |
1939 | } | |
1940 | ||
46cf9fa2 ILT |
1941 | // Do a relocation in which we convert a TLS Local-Dynamic to a |
1942 | // Local-Exec. | |
1943 | ||
1944 | inline void | |
1945 | Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo, | |
1946 | size_t relnum, | |
1947 | Output_segment*, | |
1948 | const elfcpp::Rel<32, false>& rel, | |
1949 | unsigned int, | |
1950 | elfcpp::Elf_types<32>::Elf_Addr, | |
1951 | unsigned char* view, | |
1952 | off_t view_size) | |
1953 | { | |
1954 | // leal foo(%reg), %eax; call ___tls_get_addr | |
1955 | // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi | |
1956 | ||
af6359d5 ILT |
1957 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2); |
1958 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9); | |
46cf9fa2 ILT |
1959 | |
1960 | // FIXME: Does this test really always pass? | |
af6359d5 ILT |
1961 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
1962 | view[-2] == 0x8d && view[-1] == 0x83); | |
46cf9fa2 | 1963 | |
af6359d5 | 1964 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8); |
46cf9fa2 ILT |
1965 | |
1966 | memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11); | |
1967 | ||
1968 | // The next reloc should be a PLT32 reloc against __tls_get_addr. | |
1969 | // We can skip it. | |
1970 | this->skip_call_tls_get_addr_ = true; | |
1971 | } | |
1972 | ||
56622147 ILT |
1973 | // Do a relocation in which we convert a TLS Initial-Exec to a |
1974 | // Local-Exec. | |
1975 | ||
1976 | inline void | |
1977 | Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo, | |
1978 | size_t relnum, | |
1979 | Output_segment* tls_segment, | |
1980 | const elfcpp::Rel<32, false>& rel, | |
1981 | unsigned int r_type, | |
1982 | elfcpp::Elf_types<32>::Elf_Addr value, | |
1983 | unsigned char* view, | |
1984 | off_t view_size) | |
1985 | { | |
1986 | // We have to actually change the instructions, which means that we | |
1987 | // need to examine the opcodes to figure out which instruction we | |
1988 | // are looking at. | |
1989 | if (r_type == elfcpp::R_386_TLS_IE) | |
1990 | { | |
1991 | // movl %gs:XX,%eax ==> movl $YY,%eax | |
1992 | // movl %gs:XX,%reg ==> movl $YY,%reg | |
1993 | // addl %gs:XX,%reg ==> addl $YY,%reg | |
1994 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -1); | |
1995 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4); | |
1996 | ||
1997 | unsigned char op1 = view[-1]; | |
1998 | if (op1 == 0xa1) | |
1999 | { | |
2000 | // movl XX,%eax ==> movl $YY,%eax | |
2001 | view[-1] = 0xb8; | |
2002 | } | |
2003 | else | |
2004 | { | |
2005 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2); | |
2006 | ||
2007 | unsigned char op2 = view[-2]; | |
2008 | if (op2 == 0x8b) | |
2009 | { | |
2010 | // movl XX,%reg ==> movl $YY,%reg | |
2011 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), | |
2012 | (op1 & 0xc7) == 0x05); | |
2013 | view[-2] = 0xc7; | |
2014 | view[-1] = 0xc0 | ((op1 >> 3) & 7); | |
2015 | } | |
2016 | else if (op2 == 0x03) | |
2017 | { | |
2018 | // addl XX,%reg ==> addl $YY,%reg | |
2019 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), | |
2020 | (op1 & 0xc7) == 0x05); | |
2021 | view[-2] = 0x81; | |
2022 | view[-1] = 0xc0 | ((op1 >> 3) & 7); | |
2023 | } | |
2024 | else | |
2025 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0); | |
2026 | } | |
2027 | } | |
2028 | else | |
2029 | { | |
2030 | // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2 | |
2031 | // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2 | |
2032 | // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2 | |
2033 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2); | |
2034 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4); | |
2035 | ||
2036 | unsigned char op1 = view[-1]; | |
2037 | unsigned char op2 = view[-2]; | |
2038 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), | |
2039 | (op1 & 0xc0) == 0x80 && (op1 & 7) != 4); | |
2040 | if (op2 == 0x8b) | |
2041 | { | |
2042 | // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2 | |
2043 | view[-2] = 0xc7; | |
2044 | view[-1] = 0xc0 | ((op1 >> 3) & 7); | |
2045 | } | |
2046 | else if (op2 == 0x2b) | |
2047 | { | |
2048 | // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2 | |
2049 | view[-2] = 0x81; | |
2050 | view[-1] = 0xe8 | ((op1 >> 3) & 7); | |
2051 | } | |
2052 | else if (op2 == 0x03) | |
2053 | { | |
2054 | // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2 | |
2055 | view[-2] = 0x81; | |
2056 | view[-1] = 0xc0 | ((op1 >> 3) & 7); | |
2057 | } | |
2058 | else | |
2059 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0); | |
2060 | } | |
2061 | ||
2062 | value = tls_segment->vaddr() + tls_segment->memsz() - value; | |
2063 | if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE) | |
2064 | value = - value; | |
2065 | ||
2066 | Relocate_functions<32, false>::rel32(view, value); | |
2067 | } | |
2068 | ||
61ba1cf9 ILT |
2069 | // Relocate section data. |
2070 | ||
2071 | void | |
92e059d8 | 2072 | Target_i386::relocate_section(const Relocate_info<32, false>* relinfo, |
61ba1cf9 ILT |
2073 | unsigned int sh_type, |
2074 | const unsigned char* prelocs, | |
2075 | size_t reloc_count, | |
730cdc88 ILT |
2076 | Output_section* output_section, |
2077 | bool needs_special_offset_handling, | |
61ba1cf9 ILT |
2078 | unsigned char* view, |
2079 | elfcpp::Elf_types<32>::Elf_Addr address, | |
2080 | off_t view_size) | |
2081 | { | |
a3ad94ed | 2082 | gold_assert(sh_type == elfcpp::SHT_REL); |
61ba1cf9 | 2083 | |
ead1e424 ILT |
2084 | gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL, |
2085 | Target_i386::Relocate>( | |
92e059d8 | 2086 | relinfo, |
ead1e424 | 2087 | this, |
61ba1cf9 ILT |
2088 | prelocs, |
2089 | reloc_count, | |
730cdc88 ILT |
2090 | output_section, |
2091 | needs_special_offset_handling, | |
61ba1cf9 ILT |
2092 | view, |
2093 | address, | |
2094 | view_size); | |
2095 | } | |
2096 | ||
ab5c9e90 ILT |
2097 | // Return the value to use for a dynamic which requires special |
2098 | // treatment. This is how we support equality comparisons of function | |
2099 | // pointers across shared library boundaries, as described in the | |
2100 | // processor specific ABI supplement. | |
2101 | ||
2102 | uint64_t | |
2103 | Target_i386::do_dynsym_value(const Symbol* gsym) const | |
2104 | { | |
2105 | gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset()); | |
2106 | return this->plt_section()->address() + gsym->plt_offset(); | |
2107 | } | |
2108 | ||
c51e6221 ILT |
2109 | // Return a string used to fill a code section with nops to take up |
2110 | // the specified length. | |
2111 | ||
2112 | std::string | |
2113 | Target_i386::do_code_fill(off_t length) | |
2114 | { | |
2115 | if (length >= 16) | |
2116 | { | |
2117 | // Build a jmp instruction to skip over the bytes. | |
2118 | unsigned char jmp[5]; | |
2119 | jmp[0] = 0xe9; | |
2120 | elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5); | |
2121 | return (std::string(reinterpret_cast<char*>(&jmp[0]), 5) | |
2122 | + std::string(length - 5, '\0')); | |
2123 | } | |
2124 | ||
2125 | // Nop sequences of various lengths. | |
2126 | const char nop1[1] = { 0x90 }; // nop | |
2127 | const char nop2[2] = { 0x66, 0x90 }; // xchg %ax %ax | |
2128 | const char nop3[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi | |
2129 | const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi | |
2130 | const char nop5[5] = { 0x90, 0x8d, 0x74, 0x26, // nop | |
2131 | 0x00 }; // leal 0(%esi,1),%esi | |
2132 | const char nop6[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi | |
2133 | 0x00, 0x00 }; | |
2134 | const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi | |
2135 | 0x00, 0x00, 0x00 }; | |
2136 | const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop | |
2137 | 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi | |
2138 | const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi | |
2139 | 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi | |
2140 | 0x00 }; | |
2141 | const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi | |
2142 | 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi | |
2143 | 0x00, 0x00 }; | |
2144 | const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi | |
2145 | 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi | |
2146 | 0x00, 0x00, 0x00 }; | |
2147 | const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi | |
2148 | 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi | |
2149 | 0x00, 0x00, 0x00, 0x00 }; | |
2150 | const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi | |
2151 | 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi | |
2152 | 0x27, 0x00, 0x00, 0x00, | |
2153 | 0x00 }; | |
2154 | const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi | |
2155 | 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi | |
2156 | 0xbc, 0x27, 0x00, 0x00, | |
2157 | 0x00, 0x00 }; | |
2158 | const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15 | |
2159 | 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,... | |
2160 | 0x90, 0x90, 0x90, 0x90, | |
2161 | 0x90, 0x90, 0x90 }; | |
2162 | ||
2163 | const char* nops[16] = { | |
2164 | NULL, | |
2165 | nop1, nop2, nop3, nop4, nop5, nop6, nop7, | |
2166 | nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15 | |
2167 | }; | |
2168 | ||
2169 | return std::string(nops[length], length); | |
2170 | } | |
2171 | ||
14bfc3f5 ILT |
2172 | // The selector for i386 object files. |
2173 | ||
2174 | class Target_selector_i386 : public Target_selector | |
2175 | { | |
2176 | public: | |
2177 | Target_selector_i386() | |
2178 | : Target_selector(elfcpp::EM_386, 32, false) | |
2179 | { } | |
2180 | ||
2181 | Target* | |
ead1e424 ILT |
2182 | recognize(int machine, int osabi, int abiversion); |
2183 | ||
2184 | private: | |
2185 | Target_i386* target_; | |
14bfc3f5 ILT |
2186 | }; |
2187 | ||
2188 | // Recognize an i386 object file when we already know that the machine | |
2189 | // number is EM_386. | |
2190 | ||
2191 | Target* | |
ead1e424 | 2192 | Target_selector_i386::recognize(int, int, int) |
14bfc3f5 | 2193 | { |
ead1e424 ILT |
2194 | if (this->target_ == NULL) |
2195 | this->target_ = new Target_i386(); | |
2196 | return this->target_; | |
14bfc3f5 ILT |
2197 | } |
2198 | ||
2199 | Target_selector_i386 target_selector_i386; | |
2200 | ||
2201 | } // End anonymous namespace. |