| 1 | // i386.cc -- i386 target support for gold. |
| 2 | |
| 3 | // Copyright 2006, 2007, 2008 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 | |
| 23 | #include "gold.h" |
| 24 | |
| 25 | #include <cstring> |
| 26 | |
| 27 | #include "elfcpp.h" |
| 28 | #include "parameters.h" |
| 29 | #include "reloc.h" |
| 30 | #include "i386.h" |
| 31 | #include "object.h" |
| 32 | #include "symtab.h" |
| 33 | #include "layout.h" |
| 34 | #include "output.h" |
| 35 | #include "copy-relocs.h" |
| 36 | #include "target.h" |
| 37 | #include "target-reloc.h" |
| 38 | #include "target-select.h" |
| 39 | #include "tls.h" |
| 40 | |
| 41 | namespace |
| 42 | { |
| 43 | |
| 44 | using namespace gold; |
| 45 | |
| 46 | class Output_data_plt_i386; |
| 47 | |
| 48 | // The i386 target class. |
| 49 | // TLS info comes from |
| 50 | // http://people.redhat.com/drepper/tls.pdf |
| 51 | // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt |
| 52 | |
| 53 | class Target_i386 : public Sized_target<32, false> |
| 54 | { |
| 55 | public: |
| 56 | typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section; |
| 57 | |
| 58 | Target_i386() |
| 59 | : Sized_target<32, false>(&i386_info), |
| 60 | got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL), |
| 61 | copy_relocs_(elfcpp::R_386_COPY), dynbss_(NULL), |
| 62 | got_mod_index_offset_(-1U), tls_base_symbol_defined_(false) |
| 63 | { } |
| 64 | |
| 65 | // Scan the relocations to look for symbol adjustments. |
| 66 | void |
| 67 | scan_relocs(const General_options& options, |
| 68 | Symbol_table* symtab, |
| 69 | Layout* layout, |
| 70 | Sized_relobj<32, false>* object, |
| 71 | unsigned int data_shndx, |
| 72 | unsigned int sh_type, |
| 73 | const unsigned char* prelocs, |
| 74 | size_t reloc_count, |
| 75 | Output_section* output_section, |
| 76 | bool needs_special_offset_handling, |
| 77 | size_t local_symbol_count, |
| 78 | const unsigned char* plocal_symbols); |
| 79 | |
| 80 | // Finalize the sections. |
| 81 | void |
| 82 | do_finalize_sections(Layout*); |
| 83 | |
| 84 | // Return the value to use for a dynamic which requires special |
| 85 | // treatment. |
| 86 | uint64_t |
| 87 | do_dynsym_value(const Symbol*) const; |
| 88 | |
| 89 | // Relocate a section. |
| 90 | void |
| 91 | relocate_section(const Relocate_info<32, false>*, |
| 92 | unsigned int sh_type, |
| 93 | const unsigned char* prelocs, |
| 94 | size_t reloc_count, |
| 95 | Output_section* output_section, |
| 96 | bool needs_special_offset_handling, |
| 97 | unsigned char* view, |
| 98 | elfcpp::Elf_types<32>::Elf_Addr view_address, |
| 99 | section_size_type view_size); |
| 100 | |
| 101 | // Scan the relocs during a relocatable link. |
| 102 | void |
| 103 | scan_relocatable_relocs(const General_options& options, |
| 104 | Symbol_table* symtab, |
| 105 | Layout* layout, |
| 106 | Sized_relobj<32, false>* object, |
| 107 | unsigned int data_shndx, |
| 108 | unsigned int sh_type, |
| 109 | const unsigned char* prelocs, |
| 110 | size_t reloc_count, |
| 111 | Output_section* output_section, |
| 112 | bool needs_special_offset_handling, |
| 113 | size_t local_symbol_count, |
| 114 | const unsigned char* plocal_symbols, |
| 115 | Relocatable_relocs*); |
| 116 | |
| 117 | // Relocate a section during a relocatable link. |
| 118 | void |
| 119 | relocate_for_relocatable(const Relocate_info<32, false>*, |
| 120 | unsigned int sh_type, |
| 121 | const unsigned char* prelocs, |
| 122 | size_t reloc_count, |
| 123 | Output_section* output_section, |
| 124 | off_t offset_in_output_section, |
| 125 | const Relocatable_relocs*, |
| 126 | unsigned char* view, |
| 127 | elfcpp::Elf_types<32>::Elf_Addr view_address, |
| 128 | section_size_type view_size, |
| 129 | unsigned char* reloc_view, |
| 130 | section_size_type reloc_view_size); |
| 131 | |
| 132 | // Return a string used to fill a code section with nops. |
| 133 | std::string |
| 134 | do_code_fill(section_size_type length) const; |
| 135 | |
| 136 | // Return whether SYM is defined by the ABI. |
| 137 | bool |
| 138 | do_is_defined_by_abi(const Symbol* sym) const |
| 139 | { return strcmp(sym->name(), "___tls_get_addr") == 0; } |
| 140 | |
| 141 | // Return the size of the GOT section. |
| 142 | section_size_type |
| 143 | got_size() |
| 144 | { |
| 145 | gold_assert(this->got_ != NULL); |
| 146 | return this->got_->data_size(); |
| 147 | } |
| 148 | |
| 149 | private: |
| 150 | // The class which scans relocations. |
| 151 | struct Scan |
| 152 | { |
| 153 | inline void |
| 154 | local(const General_options& options, Symbol_table* symtab, |
| 155 | Layout* layout, Target_i386* target, |
| 156 | Sized_relobj<32, false>* object, |
| 157 | unsigned int data_shndx, |
| 158 | Output_section* output_section, |
| 159 | const elfcpp::Rel<32, false>& reloc, unsigned int r_type, |
| 160 | const elfcpp::Sym<32, false>& lsym); |
| 161 | |
| 162 | inline void |
| 163 | global(const General_options& options, Symbol_table* symtab, |
| 164 | Layout* layout, Target_i386* target, |
| 165 | Sized_relobj<32, false>* object, |
| 166 | unsigned int data_shndx, |
| 167 | Output_section* output_section, |
| 168 | const elfcpp::Rel<32, false>& reloc, unsigned int r_type, |
| 169 | Symbol* gsym); |
| 170 | |
| 171 | static void |
| 172 | unsupported_reloc_local(Sized_relobj<32, false>*, unsigned int r_type); |
| 173 | |
| 174 | static void |
| 175 | unsupported_reloc_global(Sized_relobj<32, false>*, unsigned int r_type, |
| 176 | Symbol*); |
| 177 | }; |
| 178 | |
| 179 | // The class which implements relocation. |
| 180 | class Relocate |
| 181 | { |
| 182 | public: |
| 183 | Relocate() |
| 184 | : skip_call_tls_get_addr_(false), |
| 185 | local_dynamic_type_(LOCAL_DYNAMIC_NONE) |
| 186 | { } |
| 187 | |
| 188 | ~Relocate() |
| 189 | { |
| 190 | if (this->skip_call_tls_get_addr_) |
| 191 | { |
| 192 | // FIXME: This needs to specify the location somehow. |
| 193 | gold_error(_("missing expected TLS relocation")); |
| 194 | } |
| 195 | } |
| 196 | |
| 197 | // Return whether the static relocation needs to be applied. |
| 198 | inline bool |
| 199 | should_apply_static_reloc(const Sized_symbol<32>* gsym, |
| 200 | int ref_flags, |
| 201 | bool is_32bit); |
| 202 | |
| 203 | // Do a relocation. Return false if the caller should not issue |
| 204 | // any warnings about this relocation. |
| 205 | inline bool |
| 206 | relocate(const Relocate_info<32, false>*, Target_i386*, size_t relnum, |
| 207 | const elfcpp::Rel<32, false>&, |
| 208 | unsigned int r_type, const Sized_symbol<32>*, |
| 209 | const Symbol_value<32>*, |
| 210 | unsigned char*, elfcpp::Elf_types<32>::Elf_Addr, |
| 211 | section_size_type); |
| 212 | |
| 213 | private: |
| 214 | // Do a TLS relocation. |
| 215 | inline void |
| 216 | relocate_tls(const Relocate_info<32, false>*, Target_i386* target, |
| 217 | size_t relnum, const elfcpp::Rel<32, false>&, |
| 218 | unsigned int r_type, const Sized_symbol<32>*, |
| 219 | const Symbol_value<32>*, |
| 220 | unsigned char*, elfcpp::Elf_types<32>::Elf_Addr, |
| 221 | section_size_type); |
| 222 | |
| 223 | // Do a TLS General-Dynamic to Initial-Exec transition. |
| 224 | inline void |
| 225 | tls_gd_to_ie(const Relocate_info<32, false>*, size_t relnum, |
| 226 | Output_segment* tls_segment, |
| 227 | const elfcpp::Rel<32, false>&, unsigned int r_type, |
| 228 | elfcpp::Elf_types<32>::Elf_Addr value, |
| 229 | unsigned char* view, |
| 230 | section_size_type view_size); |
| 231 | |
| 232 | // Do a TLS General-Dynamic to Local-Exec transition. |
| 233 | inline void |
| 234 | tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum, |
| 235 | Output_segment* tls_segment, |
| 236 | const elfcpp::Rel<32, false>&, unsigned int r_type, |
| 237 | elfcpp::Elf_types<32>::Elf_Addr value, |
| 238 | unsigned char* view, |
| 239 | section_size_type view_size); |
| 240 | |
| 241 | // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec |
| 242 | // transition. |
| 243 | inline void |
| 244 | tls_desc_gd_to_ie(const Relocate_info<32, false>*, size_t relnum, |
| 245 | Output_segment* tls_segment, |
| 246 | const elfcpp::Rel<32, false>&, unsigned int r_type, |
| 247 | elfcpp::Elf_types<32>::Elf_Addr value, |
| 248 | unsigned char* view, |
| 249 | section_size_type view_size); |
| 250 | |
| 251 | // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec |
| 252 | // transition. |
| 253 | inline void |
| 254 | tls_desc_gd_to_le(const Relocate_info<32, false>*, size_t relnum, |
| 255 | Output_segment* tls_segment, |
| 256 | const elfcpp::Rel<32, false>&, unsigned int r_type, |
| 257 | elfcpp::Elf_types<32>::Elf_Addr value, |
| 258 | unsigned char* view, |
| 259 | section_size_type view_size); |
| 260 | |
| 261 | // Do a TLS Local-Dynamic to Local-Exec transition. |
| 262 | inline void |
| 263 | tls_ld_to_le(const Relocate_info<32, false>*, size_t relnum, |
| 264 | Output_segment* tls_segment, |
| 265 | const elfcpp::Rel<32, false>&, unsigned int r_type, |
| 266 | elfcpp::Elf_types<32>::Elf_Addr value, |
| 267 | unsigned char* view, |
| 268 | section_size_type view_size); |
| 269 | |
| 270 | // Do a TLS Initial-Exec to Local-Exec transition. |
| 271 | static inline void |
| 272 | tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum, |
| 273 | Output_segment* tls_segment, |
| 274 | const elfcpp::Rel<32, false>&, unsigned int r_type, |
| 275 | elfcpp::Elf_types<32>::Elf_Addr value, |
| 276 | unsigned char* view, |
| 277 | section_size_type view_size); |
| 278 | |
| 279 | // We need to keep track of which type of local dynamic relocation |
| 280 | // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly. |
| 281 | enum Local_dynamic_type |
| 282 | { |
| 283 | LOCAL_DYNAMIC_NONE, |
| 284 | LOCAL_DYNAMIC_SUN, |
| 285 | LOCAL_DYNAMIC_GNU |
| 286 | }; |
| 287 | |
| 288 | // This is set if we should skip the next reloc, which should be a |
| 289 | // PLT32 reloc against ___tls_get_addr. |
| 290 | bool skip_call_tls_get_addr_; |
| 291 | // The type of local dynamic relocation we have seen in the section |
| 292 | // being relocated, if any. |
| 293 | Local_dynamic_type local_dynamic_type_; |
| 294 | }; |
| 295 | |
| 296 | // A class which returns the size required for a relocation type, |
| 297 | // used while scanning relocs during a relocatable link. |
| 298 | class Relocatable_size_for_reloc |
| 299 | { |
| 300 | public: |
| 301 | unsigned int |
| 302 | get_size_for_reloc(unsigned int, Relobj*); |
| 303 | }; |
| 304 | |
| 305 | // Adjust TLS relocation type based on the options and whether this |
| 306 | // is a local symbol. |
| 307 | static tls::Tls_optimization |
| 308 | optimize_tls_reloc(bool is_final, int r_type); |
| 309 | |
| 310 | // Get the GOT section, creating it if necessary. |
| 311 | Output_data_got<32, false>* |
| 312 | got_section(Symbol_table*, Layout*); |
| 313 | |
| 314 | // Get the GOT PLT section. |
| 315 | Output_data_space* |
| 316 | got_plt_section() const |
| 317 | { |
| 318 | gold_assert(this->got_plt_ != NULL); |
| 319 | return this->got_plt_; |
| 320 | } |
| 321 | |
| 322 | // Create a PLT entry for a global symbol. |
| 323 | void |
| 324 | make_plt_entry(Symbol_table*, Layout*, Symbol*); |
| 325 | |
| 326 | // Define the _TLS_MODULE_BASE_ symbol in the TLS segment. |
| 327 | void |
| 328 | define_tls_base_symbol(Symbol_table*, Layout*); |
| 329 | |
| 330 | // Create a GOT entry for the TLS module index. |
| 331 | unsigned int |
| 332 | got_mod_index_entry(Symbol_table* symtab, Layout* layout, |
| 333 | Sized_relobj<32, false>* object); |
| 334 | |
| 335 | // Get the PLT section. |
| 336 | const Output_data_plt_i386* |
| 337 | plt_section() const |
| 338 | { |
| 339 | gold_assert(this->plt_ != NULL); |
| 340 | return this->plt_; |
| 341 | } |
| 342 | |
| 343 | // Get the dynamic reloc section, creating it if necessary. |
| 344 | Reloc_section* |
| 345 | rel_dyn_section(Layout*); |
| 346 | |
| 347 | // Return true if the symbol may need a COPY relocation. |
| 348 | // References from an executable object to non-function symbols |
| 349 | // defined in a dynamic object may need a COPY relocation. |
| 350 | bool |
| 351 | may_need_copy_reloc(Symbol* gsym) |
| 352 | { |
| 353 | return (!parameters->options().shared() |
| 354 | && gsym->is_from_dynobj() |
| 355 | && gsym->type() != elfcpp::STT_FUNC); |
| 356 | } |
| 357 | |
| 358 | // Add a potential copy relocation. |
| 359 | void |
| 360 | copy_reloc(Symbol_table* symtab, Layout* layout, |
| 361 | Sized_relobj<32, false>* object, |
| 362 | unsigned int shndx, Output_section* output_section, |
| 363 | Symbol* sym, const elfcpp::Rel<32, false>& reloc) |
| 364 | { |
| 365 | this->copy_relocs_.copy_reloc(symtab, layout, |
| 366 | symtab->get_sized_symbol<32>(sym), |
| 367 | object, shndx, output_section, reloc, |
| 368 | this->rel_dyn_section(layout)); |
| 369 | } |
| 370 | |
| 371 | // Information about this specific target which we pass to the |
| 372 | // general Target structure. |
| 373 | static const Target::Target_info i386_info; |
| 374 | |
| 375 | // The types of GOT entries needed for this platform. |
| 376 | enum Got_type |
| 377 | { |
| 378 | GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol |
| 379 | GOT_TYPE_TLS_NOFFSET = 1, // GOT entry for negative TLS offset |
| 380 | GOT_TYPE_TLS_OFFSET = 2, // GOT entry for positive TLS offset |
| 381 | GOT_TYPE_TLS_PAIR = 3, // GOT entry for TLS module/offset pair |
| 382 | GOT_TYPE_TLS_DESC = 4 // GOT entry for TLS_DESC pair |
| 383 | }; |
| 384 | |
| 385 | // The GOT section. |
| 386 | Output_data_got<32, false>* got_; |
| 387 | // The PLT section. |
| 388 | Output_data_plt_i386* plt_; |
| 389 | // The GOT PLT section. |
| 390 | Output_data_space* got_plt_; |
| 391 | // The dynamic reloc section. |
| 392 | Reloc_section* rel_dyn_; |
| 393 | // Relocs saved to avoid a COPY reloc. |
| 394 | Copy_relocs<elfcpp::SHT_REL, 32, false> copy_relocs_; |
| 395 | // Space for variables copied with a COPY reloc. |
| 396 | Output_data_space* dynbss_; |
| 397 | // Offset of the GOT entry for the TLS module index. |
| 398 | unsigned int got_mod_index_offset_; |
| 399 | // True if the _TLS_MODULE_BASE_ symbol has been defined. |
| 400 | bool tls_base_symbol_defined_; |
| 401 | }; |
| 402 | |
| 403 | const Target::Target_info Target_i386::i386_info = |
| 404 | { |
| 405 | 32, // size |
| 406 | false, // is_big_endian |
| 407 | elfcpp::EM_386, // machine_code |
| 408 | false, // has_make_symbol |
| 409 | false, // has_resolve |
| 410 | true, // has_code_fill |
| 411 | true, // is_default_stack_executable |
| 412 | '\0', // wrap_char |
| 413 | "/usr/lib/libc.so.1", // dynamic_linker |
| 414 | 0x08048000, // default_text_segment_address |
| 415 | 0x1000, // abi_pagesize (overridable by -z max-page-size) |
| 416 | 0x1000 // common_pagesize (overridable by -z common-page-size) |
| 417 | }; |
| 418 | |
| 419 | // Get the GOT section, creating it if necessary. |
| 420 | |
| 421 | Output_data_got<32, false>* |
| 422 | Target_i386::got_section(Symbol_table* symtab, Layout* layout) |
| 423 | { |
| 424 | if (this->got_ == NULL) |
| 425 | { |
| 426 | gold_assert(symtab != NULL && layout != NULL); |
| 427 | |
| 428 | this->got_ = new Output_data_got<32, false>(); |
| 429 | |
| 430 | Output_section* os; |
| 431 | os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS, |
| 432 | (elfcpp::SHF_ALLOC |
| 433 | | elfcpp::SHF_WRITE), |
| 434 | this->got_); |
| 435 | os->set_is_relro(); |
| 436 | |
| 437 | // The old GNU linker creates a .got.plt section. We just |
| 438 | // create another set of data in the .got section. Note that we |
| 439 | // always create a PLT if we create a GOT, although the PLT |
| 440 | // might be empty. |
| 441 | this->got_plt_ = new Output_data_space(4, "** GOT PLT"); |
| 442 | os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS, |
| 443 | (elfcpp::SHF_ALLOC |
| 444 | | elfcpp::SHF_WRITE), |
| 445 | this->got_plt_); |
| 446 | os->set_is_relro(); |
| 447 | |
| 448 | // The first three entries are reserved. |
| 449 | this->got_plt_->set_current_data_size(3 * 4); |
| 450 | |
| 451 | // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT. |
| 452 | symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL, |
| 453 | this->got_plt_, |
| 454 | 0, 0, elfcpp::STT_OBJECT, |
| 455 | elfcpp::STB_LOCAL, |
| 456 | elfcpp::STV_HIDDEN, 0, |
| 457 | false, false); |
| 458 | } |
| 459 | |
| 460 | return this->got_; |
| 461 | } |
| 462 | |
| 463 | // Get the dynamic reloc section, creating it if necessary. |
| 464 | |
| 465 | Target_i386::Reloc_section* |
| 466 | Target_i386::rel_dyn_section(Layout* layout) |
| 467 | { |
| 468 | if (this->rel_dyn_ == NULL) |
| 469 | { |
| 470 | gold_assert(layout != NULL); |
| 471 | this->rel_dyn_ = new Reloc_section(parameters->options().combreloc()); |
| 472 | layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL, |
| 473 | elfcpp::SHF_ALLOC, this->rel_dyn_); |
| 474 | } |
| 475 | return this->rel_dyn_; |
| 476 | } |
| 477 | |
| 478 | // A class to handle the PLT data. |
| 479 | |
| 480 | class Output_data_plt_i386 : public Output_section_data |
| 481 | { |
| 482 | public: |
| 483 | typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section; |
| 484 | |
| 485 | Output_data_plt_i386(Layout*, Output_data_space*); |
| 486 | |
| 487 | // Add an entry to the PLT. |
| 488 | void |
| 489 | add_entry(Symbol* gsym); |
| 490 | |
| 491 | // Return the .rel.plt section data. |
| 492 | const Reloc_section* |
| 493 | rel_plt() const |
| 494 | { return this->rel_; } |
| 495 | |
| 496 | protected: |
| 497 | void |
| 498 | do_adjust_output_section(Output_section* os); |
| 499 | |
| 500 | // Write to a map file. |
| 501 | void |
| 502 | do_print_to_mapfile(Mapfile* mapfile) const |
| 503 | { mapfile->print_output_data(this, _("** PLT")); } |
| 504 | |
| 505 | private: |
| 506 | // The size of an entry in the PLT. |
| 507 | static const int plt_entry_size = 16; |
| 508 | |
| 509 | // The first entry in the PLT for an executable. |
| 510 | static unsigned char exec_first_plt_entry[plt_entry_size]; |
| 511 | |
| 512 | // The first entry in the PLT for a shared object. |
| 513 | static unsigned char dyn_first_plt_entry[plt_entry_size]; |
| 514 | |
| 515 | // Other entries in the PLT for an executable. |
| 516 | static unsigned char exec_plt_entry[plt_entry_size]; |
| 517 | |
| 518 | // Other entries in the PLT for a shared object. |
| 519 | static unsigned char dyn_plt_entry[plt_entry_size]; |
| 520 | |
| 521 | // Set the final size. |
| 522 | void |
| 523 | set_final_data_size() |
| 524 | { this->set_data_size((this->count_ + 1) * plt_entry_size); } |
| 525 | |
| 526 | // Write out the PLT data. |
| 527 | void |
| 528 | do_write(Output_file*); |
| 529 | |
| 530 | // The reloc section. |
| 531 | Reloc_section* rel_; |
| 532 | // The .got.plt section. |
| 533 | Output_data_space* got_plt_; |
| 534 | // The number of PLT entries. |
| 535 | unsigned int count_; |
| 536 | }; |
| 537 | |
| 538 | // Create the PLT section. The ordinary .got section is an argument, |
| 539 | // since we need to refer to the start. We also create our own .got |
| 540 | // section just for PLT entries. |
| 541 | |
| 542 | Output_data_plt_i386::Output_data_plt_i386(Layout* layout, |
| 543 | Output_data_space* got_plt) |
| 544 | : Output_section_data(4), got_plt_(got_plt), count_(0) |
| 545 | { |
| 546 | this->rel_ = new Reloc_section(false); |
| 547 | layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL, |
| 548 | elfcpp::SHF_ALLOC, this->rel_); |
| 549 | } |
| 550 | |
| 551 | void |
| 552 | Output_data_plt_i386::do_adjust_output_section(Output_section* os) |
| 553 | { |
| 554 | // UnixWare sets the entsize of .plt to 4, and so does the old GNU |
| 555 | // linker, and so do we. |
| 556 | os->set_entsize(4); |
| 557 | } |
| 558 | |
| 559 | // Add an entry to the PLT. |
| 560 | |
| 561 | void |
| 562 | Output_data_plt_i386::add_entry(Symbol* gsym) |
| 563 | { |
| 564 | gold_assert(!gsym->has_plt_offset()); |
| 565 | |
| 566 | // Note that when setting the PLT offset we skip the initial |
| 567 | // reserved PLT entry. |
| 568 | gsym->set_plt_offset((this->count_ + 1) * plt_entry_size); |
| 569 | |
| 570 | ++this->count_; |
| 571 | |
| 572 | section_offset_type got_offset = this->got_plt_->current_data_size(); |
| 573 | |
| 574 | // Every PLT entry needs a GOT entry which points back to the PLT |
| 575 | // entry (this will be changed by the dynamic linker, normally |
| 576 | // lazily when the function is called). |
| 577 | this->got_plt_->set_current_data_size(got_offset + 4); |
| 578 | |
| 579 | // Every PLT entry needs a reloc. |
| 580 | gsym->set_needs_dynsym_entry(); |
| 581 | this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_, |
| 582 | got_offset); |
| 583 | |
| 584 | // Note that we don't need to save the symbol. The contents of the |
| 585 | // PLT are independent of which symbols are used. The symbols only |
| 586 | // appear in the relocations. |
| 587 | } |
| 588 | |
| 589 | // The first entry in the PLT for an executable. |
| 590 | |
| 591 | unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] = |
| 592 | { |
| 593 | 0xff, 0x35, // pushl contents of memory address |
| 594 | 0, 0, 0, 0, // replaced with address of .got + 4 |
| 595 | 0xff, 0x25, // jmp indirect |
| 596 | 0, 0, 0, 0, // replaced with address of .got + 8 |
| 597 | 0, 0, 0, 0 // unused |
| 598 | }; |
| 599 | |
| 600 | // The first entry in the PLT for a shared object. |
| 601 | |
| 602 | unsigned char Output_data_plt_i386::dyn_first_plt_entry[plt_entry_size] = |
| 603 | { |
| 604 | 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx) |
| 605 | 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx) |
| 606 | 0, 0, 0, 0 // unused |
| 607 | }; |
| 608 | |
| 609 | // Subsequent entries in the PLT for an executable. |
| 610 | |
| 611 | unsigned char Output_data_plt_i386::exec_plt_entry[plt_entry_size] = |
| 612 | { |
| 613 | 0xff, 0x25, // jmp indirect |
| 614 | 0, 0, 0, 0, // replaced with address of symbol in .got |
| 615 | 0x68, // pushl immediate |
| 616 | 0, 0, 0, 0, // replaced with offset into relocation table |
| 617 | 0xe9, // jmp relative |
| 618 | 0, 0, 0, 0 // replaced with offset to start of .plt |
| 619 | }; |
| 620 | |
| 621 | // Subsequent entries in the PLT for a shared object. |
| 622 | |
| 623 | unsigned char Output_data_plt_i386::dyn_plt_entry[plt_entry_size] = |
| 624 | { |
| 625 | 0xff, 0xa3, // jmp *offset(%ebx) |
| 626 | 0, 0, 0, 0, // replaced with offset of symbol in .got |
| 627 | 0x68, // pushl immediate |
| 628 | 0, 0, 0, 0, // replaced with offset into relocation table |
| 629 | 0xe9, // jmp relative |
| 630 | 0, 0, 0, 0 // replaced with offset to start of .plt |
| 631 | }; |
| 632 | |
| 633 | // Write out the PLT. This uses the hand-coded instructions above, |
| 634 | // and adjusts them as needed. This is all specified by the i386 ELF |
| 635 | // Processor Supplement. |
| 636 | |
| 637 | void |
| 638 | Output_data_plt_i386::do_write(Output_file* of) |
| 639 | { |
| 640 | const off_t offset = this->offset(); |
| 641 | const section_size_type oview_size = |
| 642 | convert_to_section_size_type(this->data_size()); |
| 643 | unsigned char* const oview = of->get_output_view(offset, oview_size); |
| 644 | |
| 645 | const off_t got_file_offset = this->got_plt_->offset(); |
| 646 | const section_size_type got_size = |
| 647 | convert_to_section_size_type(this->got_plt_->data_size()); |
| 648 | unsigned char* const got_view = of->get_output_view(got_file_offset, |
| 649 | got_size); |
| 650 | |
| 651 | unsigned char* pov = oview; |
| 652 | |
| 653 | elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address(); |
| 654 | elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address(); |
| 655 | |
| 656 | if (parameters->options().shared()) |
| 657 | memcpy(pov, dyn_first_plt_entry, plt_entry_size); |
| 658 | else |
| 659 | { |
| 660 | memcpy(pov, exec_first_plt_entry, plt_entry_size); |
| 661 | elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4); |
| 662 | elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8); |
| 663 | } |
| 664 | pov += plt_entry_size; |
| 665 | |
| 666 | unsigned char* got_pov = got_view; |
| 667 | |
| 668 | memset(got_pov, 0, 12); |
| 669 | got_pov += 12; |
| 670 | |
| 671 | const int rel_size = elfcpp::Elf_sizes<32>::rel_size; |
| 672 | |
| 673 | unsigned int plt_offset = plt_entry_size; |
| 674 | unsigned int plt_rel_offset = 0; |
| 675 | unsigned int got_offset = 12; |
| 676 | const unsigned int count = this->count_; |
| 677 | for (unsigned int i = 0; |
| 678 | i < count; |
| 679 | ++i, |
| 680 | pov += plt_entry_size, |
| 681 | got_pov += 4, |
| 682 | plt_offset += plt_entry_size, |
| 683 | plt_rel_offset += rel_size, |
| 684 | got_offset += 4) |
| 685 | { |
| 686 | // Set and adjust the PLT entry itself. |
| 687 | |
| 688 | if (parameters->options().shared()) |
| 689 | { |
| 690 | memcpy(pov, dyn_plt_entry, plt_entry_size); |
| 691 | elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset); |
| 692 | } |
| 693 | else |
| 694 | { |
| 695 | memcpy(pov, exec_plt_entry, plt_entry_size); |
| 696 | elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, |
| 697 | (got_address |
| 698 | + got_offset)); |
| 699 | } |
| 700 | |
| 701 | elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset); |
| 702 | elfcpp::Swap<32, false>::writeval(pov + 12, |
| 703 | - (plt_offset + plt_entry_size)); |
| 704 | |
| 705 | // Set the entry in the GOT. |
| 706 | elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6); |
| 707 | } |
| 708 | |
| 709 | gold_assert(static_cast<section_size_type>(pov - oview) == oview_size); |
| 710 | gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size); |
| 711 | |
| 712 | of->write_output_view(offset, oview_size, oview); |
| 713 | of->write_output_view(got_file_offset, got_size, got_view); |
| 714 | } |
| 715 | |
| 716 | // Create a PLT entry for a global symbol. |
| 717 | |
| 718 | void |
| 719 | Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym) |
| 720 | { |
| 721 | if (gsym->has_plt_offset()) |
| 722 | return; |
| 723 | |
| 724 | if (this->plt_ == NULL) |
| 725 | { |
| 726 | // Create the GOT sections first. |
| 727 | this->got_section(symtab, layout); |
| 728 | |
| 729 | this->plt_ = new Output_data_plt_i386(layout, this->got_plt_); |
| 730 | layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS, |
| 731 | (elfcpp::SHF_ALLOC |
| 732 | | elfcpp::SHF_EXECINSTR), |
| 733 | this->plt_); |
| 734 | } |
| 735 | |
| 736 | this->plt_->add_entry(gsym); |
| 737 | } |
| 738 | |
| 739 | // Define the _TLS_MODULE_BASE_ symbol in the TLS segment. |
| 740 | |
| 741 | void |
| 742 | Target_i386::define_tls_base_symbol(Symbol_table* symtab, Layout* layout) |
| 743 | { |
| 744 | if (this->tls_base_symbol_defined_) |
| 745 | return; |
| 746 | |
| 747 | Output_segment* tls_segment = layout->tls_segment(); |
| 748 | if (tls_segment != NULL) |
| 749 | { |
| 750 | bool is_exec = parameters->options().output_is_executable(); |
| 751 | symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL, |
| 752 | tls_segment, 0, 0, |
| 753 | elfcpp::STT_TLS, |
| 754 | elfcpp::STB_LOCAL, |
| 755 | elfcpp::STV_HIDDEN, 0, |
| 756 | (is_exec |
| 757 | ? Symbol::SEGMENT_END |
| 758 | : Symbol::SEGMENT_START), |
| 759 | true); |
| 760 | } |
| 761 | this->tls_base_symbol_defined_ = true; |
| 762 | } |
| 763 | |
| 764 | // Create a GOT entry for the TLS module index. |
| 765 | |
| 766 | unsigned int |
| 767 | Target_i386::got_mod_index_entry(Symbol_table* symtab, Layout* layout, |
| 768 | Sized_relobj<32, false>* object) |
| 769 | { |
| 770 | if (this->got_mod_index_offset_ == -1U) |
| 771 | { |
| 772 | gold_assert(symtab != NULL && layout != NULL && object != NULL); |
| 773 | Reloc_section* rel_dyn = this->rel_dyn_section(layout); |
| 774 | Output_data_got<32, false>* got = this->got_section(symtab, layout); |
| 775 | unsigned int got_offset = got->add_constant(0); |
| 776 | rel_dyn->add_local(object, 0, elfcpp::R_386_TLS_DTPMOD32, got, |
| 777 | got_offset); |
| 778 | got->add_constant(0); |
| 779 | this->got_mod_index_offset_ = got_offset; |
| 780 | } |
| 781 | return this->got_mod_index_offset_; |
| 782 | } |
| 783 | |
| 784 | // Optimize the TLS relocation type based on what we know about the |
| 785 | // symbol. IS_FINAL is true if the final address of this symbol is |
| 786 | // known at link time. |
| 787 | |
| 788 | tls::Tls_optimization |
| 789 | Target_i386::optimize_tls_reloc(bool is_final, int r_type) |
| 790 | { |
| 791 | // If we are generating a shared library, then we can't do anything |
| 792 | // in the linker. |
| 793 | if (parameters->options().shared()) |
| 794 | return tls::TLSOPT_NONE; |
| 795 | |
| 796 | switch (r_type) |
| 797 | { |
| 798 | case elfcpp::R_386_TLS_GD: |
| 799 | case elfcpp::R_386_TLS_GOTDESC: |
| 800 | case elfcpp::R_386_TLS_DESC_CALL: |
| 801 | // These are General-Dynamic which permits fully general TLS |
| 802 | // access. Since we know that we are generating an executable, |
| 803 | // we can convert this to Initial-Exec. If we also know that |
| 804 | // this is a local symbol, we can further switch to Local-Exec. |
| 805 | if (is_final) |
| 806 | return tls::TLSOPT_TO_LE; |
| 807 | return tls::TLSOPT_TO_IE; |
| 808 | |
| 809 | case elfcpp::R_386_TLS_LDM: |
| 810 | // This is Local-Dynamic, which refers to a local symbol in the |
| 811 | // dynamic TLS block. Since we know that we generating an |
| 812 | // executable, we can switch to Local-Exec. |
| 813 | return tls::TLSOPT_TO_LE; |
| 814 | |
| 815 | case elfcpp::R_386_TLS_LDO_32: |
| 816 | // Another type of Local-Dynamic relocation. |
| 817 | return tls::TLSOPT_TO_LE; |
| 818 | |
| 819 | case elfcpp::R_386_TLS_IE: |
| 820 | case elfcpp::R_386_TLS_GOTIE: |
| 821 | case elfcpp::R_386_TLS_IE_32: |
| 822 | // These are Initial-Exec relocs which get the thread offset |
| 823 | // from the GOT. If we know that we are linking against the |
| 824 | // local symbol, we can switch to Local-Exec, which links the |
| 825 | // thread offset into the instruction. |
| 826 | if (is_final) |
| 827 | return tls::TLSOPT_TO_LE; |
| 828 | return tls::TLSOPT_NONE; |
| 829 | |
| 830 | case elfcpp::R_386_TLS_LE: |
| 831 | case elfcpp::R_386_TLS_LE_32: |
| 832 | // When we already have Local-Exec, there is nothing further we |
| 833 | // can do. |
| 834 | return tls::TLSOPT_NONE; |
| 835 | |
| 836 | default: |
| 837 | gold_unreachable(); |
| 838 | } |
| 839 | } |
| 840 | |
| 841 | // Report an unsupported relocation against a local symbol. |
| 842 | |
| 843 | void |
| 844 | Target_i386::Scan::unsupported_reloc_local(Sized_relobj<32, false>* object, |
| 845 | unsigned int r_type) |
| 846 | { |
| 847 | gold_error(_("%s: unsupported reloc %u against local symbol"), |
| 848 | object->name().c_str(), r_type); |
| 849 | } |
| 850 | |
| 851 | // Scan a relocation for a local symbol. |
| 852 | |
| 853 | inline void |
| 854 | Target_i386::Scan::local(const General_options&, |
| 855 | Symbol_table* symtab, |
| 856 | Layout* layout, |
| 857 | Target_i386* target, |
| 858 | Sized_relobj<32, false>* object, |
| 859 | unsigned int data_shndx, |
| 860 | Output_section* output_section, |
| 861 | const elfcpp::Rel<32, false>& reloc, |
| 862 | unsigned int r_type, |
| 863 | const elfcpp::Sym<32, false>& lsym) |
| 864 | { |
| 865 | switch (r_type) |
| 866 | { |
| 867 | case elfcpp::R_386_NONE: |
| 868 | case elfcpp::R_386_GNU_VTINHERIT: |
| 869 | case elfcpp::R_386_GNU_VTENTRY: |
| 870 | break; |
| 871 | |
| 872 | case elfcpp::R_386_32: |
| 873 | // If building a shared library (or a position-independent |
| 874 | // executable), we need to create a dynamic relocation for |
| 875 | // this location. The relocation applied at link time will |
| 876 | // apply the link-time value, so we flag the location with |
| 877 | // an R_386_RELATIVE relocation so the dynamic loader can |
| 878 | // relocate it easily. |
| 879 | if (parameters->options().output_is_position_independent()) |
| 880 | { |
| 881 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
| 882 | unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); |
| 883 | rel_dyn->add_local_relative(object, r_sym, elfcpp::R_386_RELATIVE, |
| 884 | output_section, data_shndx, |
| 885 | reloc.get_r_offset()); |
| 886 | } |
| 887 | break; |
| 888 | |
| 889 | case elfcpp::R_386_16: |
| 890 | case elfcpp::R_386_8: |
| 891 | // If building a shared library (or a position-independent |
| 892 | // executable), we need to create a dynamic relocation for |
| 893 | // this location. Because the addend needs to remain in the |
| 894 | // data section, we need to be careful not to apply this |
| 895 | // relocation statically. |
| 896 | if (parameters->options().output_is_position_independent()) |
| 897 | { |
| 898 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
| 899 | unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); |
| 900 | if (lsym.get_st_type() != elfcpp::STT_SECTION) |
| 901 | rel_dyn->add_local(object, r_sym, r_type, output_section, |
| 902 | data_shndx, reloc.get_r_offset()); |
| 903 | else |
| 904 | { |
| 905 | gold_assert(lsym.get_st_value() == 0); |
| 906 | unsigned int shndx = lsym.get_st_shndx(); |
| 907 | bool is_ordinary; |
| 908 | shndx = object->adjust_sym_shndx(r_sym, shndx, |
| 909 | &is_ordinary); |
| 910 | if (!is_ordinary) |
| 911 | object->error(_("section symbol %u has bad shndx %u"), |
| 912 | r_sym, shndx); |
| 913 | else |
| 914 | rel_dyn->add_local_section(object, shndx, |
| 915 | r_type, output_section, |
| 916 | data_shndx, reloc.get_r_offset()); |
| 917 | } |
| 918 | } |
| 919 | break; |
| 920 | |
| 921 | case elfcpp::R_386_PC32: |
| 922 | case elfcpp::R_386_PC16: |
| 923 | case elfcpp::R_386_PC8: |
| 924 | break; |
| 925 | |
| 926 | case elfcpp::R_386_PLT32: |
| 927 | // Since we know this is a local symbol, we can handle this as a |
| 928 | // PC32 reloc. |
| 929 | break; |
| 930 | |
| 931 | case elfcpp::R_386_GOTOFF: |
| 932 | case elfcpp::R_386_GOTPC: |
| 933 | // We need a GOT section. |
| 934 | target->got_section(symtab, layout); |
| 935 | break; |
| 936 | |
| 937 | case elfcpp::R_386_GOT32: |
| 938 | { |
| 939 | // The symbol requires a GOT entry. |
| 940 | Output_data_got<32, false>* got = target->got_section(symtab, layout); |
| 941 | unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); |
| 942 | if (got->add_local(object, r_sym, GOT_TYPE_STANDARD)) |
| 943 | { |
| 944 | // If we are generating a shared object, we need to add a |
| 945 | // dynamic RELATIVE relocation for this symbol's GOT entry. |
| 946 | if (parameters->options().output_is_position_independent()) |
| 947 | { |
| 948 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
| 949 | unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); |
| 950 | rel_dyn->add_local_relative( |
| 951 | object, r_sym, elfcpp::R_386_RELATIVE, got, |
| 952 | object->local_got_offset(r_sym, GOT_TYPE_STANDARD)); |
| 953 | } |
| 954 | } |
| 955 | } |
| 956 | break; |
| 957 | |
| 958 | // These are relocations which should only be seen by the |
| 959 | // dynamic linker, and should never be seen here. |
| 960 | case elfcpp::R_386_COPY: |
| 961 | case elfcpp::R_386_GLOB_DAT: |
| 962 | case elfcpp::R_386_JUMP_SLOT: |
| 963 | case elfcpp::R_386_RELATIVE: |
| 964 | case elfcpp::R_386_TLS_TPOFF: |
| 965 | case elfcpp::R_386_TLS_DTPMOD32: |
| 966 | case elfcpp::R_386_TLS_DTPOFF32: |
| 967 | case elfcpp::R_386_TLS_TPOFF32: |
| 968 | case elfcpp::R_386_TLS_DESC: |
| 969 | gold_error(_("%s: unexpected reloc %u in object file"), |
| 970 | object->name().c_str(), r_type); |
| 971 | break; |
| 972 | |
| 973 | // These are initial TLS relocs, which are expected when |
| 974 | // linking. |
| 975 | case elfcpp::R_386_TLS_GD: // Global-dynamic |
| 976 | case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url) |
| 977 | case elfcpp::R_386_TLS_DESC_CALL: |
| 978 | case elfcpp::R_386_TLS_LDM: // Local-dynamic |
| 979 | case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic |
| 980 | case elfcpp::R_386_TLS_IE: // Initial-exec |
| 981 | case elfcpp::R_386_TLS_IE_32: |
| 982 | case elfcpp::R_386_TLS_GOTIE: |
| 983 | case elfcpp::R_386_TLS_LE: // Local-exec |
| 984 | case elfcpp::R_386_TLS_LE_32: |
| 985 | { |
| 986 | bool output_is_shared = parameters->options().shared(); |
| 987 | const tls::Tls_optimization optimized_type |
| 988 | = Target_i386::optimize_tls_reloc(!output_is_shared, r_type); |
| 989 | switch (r_type) |
| 990 | { |
| 991 | case elfcpp::R_386_TLS_GD: // Global-dynamic |
| 992 | if (optimized_type == tls::TLSOPT_NONE) |
| 993 | { |
| 994 | // Create a pair of GOT entries for the module index and |
| 995 | // dtv-relative offset. |
| 996 | Output_data_got<32, false>* got |
| 997 | = target->got_section(symtab, layout); |
| 998 | unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); |
| 999 | unsigned int shndx = lsym.get_st_shndx(); |
| 1000 | bool is_ordinary; |
| 1001 | shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary); |
| 1002 | if (!is_ordinary) |
| 1003 | object->error(_("local symbol %u has bad shndx %u"), |
| 1004 | r_sym, shndx); |
| 1005 | else |
| 1006 | got->add_local_pair_with_rel(object, r_sym, shndx, |
| 1007 | GOT_TYPE_TLS_PAIR, |
| 1008 | target->rel_dyn_section(layout), |
| 1009 | elfcpp::R_386_TLS_DTPMOD32, 0); |
| 1010 | } |
| 1011 | else if (optimized_type != tls::TLSOPT_TO_LE) |
| 1012 | unsupported_reloc_local(object, r_type); |
| 1013 | break; |
| 1014 | |
| 1015 | case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva) |
| 1016 | target->define_tls_base_symbol(symtab, layout); |
| 1017 | if (optimized_type == tls::TLSOPT_NONE) |
| 1018 | { |
| 1019 | // Create a double GOT entry with an R_386_TLS_DESC reloc. |
| 1020 | Output_data_got<32, false>* got |
| 1021 | = target->got_section(symtab, layout); |
| 1022 | unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); |
| 1023 | unsigned int shndx = lsym.get_st_shndx(); |
| 1024 | bool is_ordinary; |
| 1025 | shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary); |
| 1026 | if (!is_ordinary) |
| 1027 | object->error(_("local symbol %u has bad shndx %u"), |
| 1028 | r_sym, shndx); |
| 1029 | else |
| 1030 | got->add_local_pair_with_rel(object, r_sym, shndx, |
| 1031 | GOT_TYPE_TLS_DESC, |
| 1032 | target->rel_dyn_section(layout), |
| 1033 | elfcpp::R_386_TLS_DESC, 0); |
| 1034 | } |
| 1035 | else if (optimized_type != tls::TLSOPT_TO_LE) |
| 1036 | unsupported_reloc_local(object, r_type); |
| 1037 | break; |
| 1038 | |
| 1039 | case elfcpp::R_386_TLS_DESC_CALL: |
| 1040 | break; |
| 1041 | |
| 1042 | case elfcpp::R_386_TLS_LDM: // Local-dynamic |
| 1043 | if (optimized_type == tls::TLSOPT_NONE) |
| 1044 | { |
| 1045 | // Create a GOT entry for the module index. |
| 1046 | target->got_mod_index_entry(symtab, layout, object); |
| 1047 | } |
| 1048 | else if (optimized_type != tls::TLSOPT_TO_LE) |
| 1049 | unsupported_reloc_local(object, r_type); |
| 1050 | break; |
| 1051 | |
| 1052 | case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic |
| 1053 | break; |
| 1054 | |
| 1055 | case elfcpp::R_386_TLS_IE: // Initial-exec |
| 1056 | case elfcpp::R_386_TLS_IE_32: |
| 1057 | case elfcpp::R_386_TLS_GOTIE: |
| 1058 | layout->set_has_static_tls(); |
| 1059 | if (optimized_type == tls::TLSOPT_NONE) |
| 1060 | { |
| 1061 | // For the R_386_TLS_IE relocation, we need to create a |
| 1062 | // dynamic relocation when building a shared library. |
| 1063 | if (r_type == elfcpp::R_386_TLS_IE |
| 1064 | && parameters->options().shared()) |
| 1065 | { |
| 1066 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
| 1067 | unsigned int r_sym |
| 1068 | = elfcpp::elf_r_sym<32>(reloc.get_r_info()); |
| 1069 | rel_dyn->add_local_relative(object, r_sym, |
| 1070 | elfcpp::R_386_RELATIVE, |
| 1071 | output_section, data_shndx, |
| 1072 | reloc.get_r_offset()); |
| 1073 | } |
| 1074 | // Create a GOT entry for the tp-relative offset. |
| 1075 | Output_data_got<32, false>* got |
| 1076 | = target->got_section(symtab, layout); |
| 1077 | unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); |
| 1078 | unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32 |
| 1079 | ? elfcpp::R_386_TLS_TPOFF32 |
| 1080 | : elfcpp::R_386_TLS_TPOFF); |
| 1081 | unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32 |
| 1082 | ? GOT_TYPE_TLS_OFFSET |
| 1083 | : GOT_TYPE_TLS_NOFFSET); |
| 1084 | got->add_local_with_rel(object, r_sym, got_type, |
| 1085 | target->rel_dyn_section(layout), |
| 1086 | dyn_r_type); |
| 1087 | } |
| 1088 | else if (optimized_type != tls::TLSOPT_TO_LE) |
| 1089 | unsupported_reloc_local(object, r_type); |
| 1090 | break; |
| 1091 | |
| 1092 | case elfcpp::R_386_TLS_LE: // Local-exec |
| 1093 | case elfcpp::R_386_TLS_LE_32: |
| 1094 | layout->set_has_static_tls(); |
| 1095 | if (output_is_shared) |
| 1096 | { |
| 1097 | // We need to create a dynamic relocation. |
| 1098 | gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION); |
| 1099 | unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); |
| 1100 | unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32 |
| 1101 | ? elfcpp::R_386_TLS_TPOFF32 |
| 1102 | : elfcpp::R_386_TLS_TPOFF); |
| 1103 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
| 1104 | rel_dyn->add_local(object, r_sym, dyn_r_type, output_section, |
| 1105 | data_shndx, reloc.get_r_offset()); |
| 1106 | } |
| 1107 | break; |
| 1108 | |
| 1109 | default: |
| 1110 | gold_unreachable(); |
| 1111 | } |
| 1112 | } |
| 1113 | break; |
| 1114 | |
| 1115 | case elfcpp::R_386_32PLT: |
| 1116 | case elfcpp::R_386_TLS_GD_32: |
| 1117 | case elfcpp::R_386_TLS_GD_PUSH: |
| 1118 | case elfcpp::R_386_TLS_GD_CALL: |
| 1119 | case elfcpp::R_386_TLS_GD_POP: |
| 1120 | case elfcpp::R_386_TLS_LDM_32: |
| 1121 | case elfcpp::R_386_TLS_LDM_PUSH: |
| 1122 | case elfcpp::R_386_TLS_LDM_CALL: |
| 1123 | case elfcpp::R_386_TLS_LDM_POP: |
| 1124 | case elfcpp::R_386_USED_BY_INTEL_200: |
| 1125 | default: |
| 1126 | unsupported_reloc_local(object, r_type); |
| 1127 | break; |
| 1128 | } |
| 1129 | } |
| 1130 | |
| 1131 | // Report an unsupported relocation against a global symbol. |
| 1132 | |
| 1133 | void |
| 1134 | Target_i386::Scan::unsupported_reloc_global(Sized_relobj<32, false>* object, |
| 1135 | unsigned int r_type, |
| 1136 | Symbol* gsym) |
| 1137 | { |
| 1138 | gold_error(_("%s: unsupported reloc %u against global symbol %s"), |
| 1139 | object->name().c_str(), r_type, gsym->demangled_name().c_str()); |
| 1140 | } |
| 1141 | |
| 1142 | // Scan a relocation for a global symbol. |
| 1143 | |
| 1144 | inline void |
| 1145 | Target_i386::Scan::global(const General_options&, |
| 1146 | Symbol_table* symtab, |
| 1147 | Layout* layout, |
| 1148 | Target_i386* target, |
| 1149 | Sized_relobj<32, false>* object, |
| 1150 | unsigned int data_shndx, |
| 1151 | Output_section* output_section, |
| 1152 | const elfcpp::Rel<32, false>& reloc, |
| 1153 | unsigned int r_type, |
| 1154 | Symbol* gsym) |
| 1155 | { |
| 1156 | switch (r_type) |
| 1157 | { |
| 1158 | case elfcpp::R_386_NONE: |
| 1159 | case elfcpp::R_386_GNU_VTINHERIT: |
| 1160 | case elfcpp::R_386_GNU_VTENTRY: |
| 1161 | break; |
| 1162 | |
| 1163 | case elfcpp::R_386_32: |
| 1164 | case elfcpp::R_386_16: |
| 1165 | case elfcpp::R_386_8: |
| 1166 | { |
| 1167 | // Make a PLT entry if necessary. |
| 1168 | if (gsym->needs_plt_entry()) |
| 1169 | { |
| 1170 | target->make_plt_entry(symtab, layout, gsym); |
| 1171 | // Since this is not a PC-relative relocation, we may be |
| 1172 | // taking the address of a function. In that case we need to |
| 1173 | // set the entry in the dynamic symbol table to the address of |
| 1174 | // the PLT entry. |
| 1175 | if (gsym->is_from_dynobj() && !parameters->options().shared()) |
| 1176 | gsym->set_needs_dynsym_value(); |
| 1177 | } |
| 1178 | // Make a dynamic relocation if necessary. |
| 1179 | if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF)) |
| 1180 | { |
| 1181 | if (target->may_need_copy_reloc(gsym)) |
| 1182 | { |
| 1183 | target->copy_reloc(symtab, layout, object, |
| 1184 | data_shndx, output_section, gsym, reloc); |
| 1185 | } |
| 1186 | else if (r_type == elfcpp::R_386_32 |
| 1187 | && gsym->can_use_relative_reloc(false)) |
| 1188 | { |
| 1189 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
| 1190 | rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE, |
| 1191 | output_section, object, |
| 1192 | data_shndx, reloc.get_r_offset()); |
| 1193 | } |
| 1194 | else |
| 1195 | { |
| 1196 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
| 1197 | rel_dyn->add_global(gsym, r_type, output_section, object, |
| 1198 | data_shndx, reloc.get_r_offset()); |
| 1199 | } |
| 1200 | } |
| 1201 | } |
| 1202 | break; |
| 1203 | |
| 1204 | case elfcpp::R_386_PC32: |
| 1205 | case elfcpp::R_386_PC16: |
| 1206 | case elfcpp::R_386_PC8: |
| 1207 | { |
| 1208 | // Make a PLT entry if necessary. |
| 1209 | if (gsym->needs_plt_entry()) |
| 1210 | { |
| 1211 | // These relocations are used for function calls only in |
| 1212 | // non-PIC code. For a 32-bit relocation in a shared library, |
| 1213 | // we'll need a text relocation anyway, so we can skip the |
| 1214 | // PLT entry and let the dynamic linker bind the call directly |
| 1215 | // to the target. For smaller relocations, we should use a |
| 1216 | // PLT entry to ensure that the call can reach. |
| 1217 | if (!parameters->options().shared() |
| 1218 | || r_type != elfcpp::R_386_PC32) |
| 1219 | target->make_plt_entry(symtab, layout, gsym); |
| 1220 | } |
| 1221 | // Make a dynamic relocation if necessary. |
| 1222 | int flags = Symbol::NON_PIC_REF; |
| 1223 | if (gsym->type() == elfcpp::STT_FUNC) |
| 1224 | flags |= Symbol::FUNCTION_CALL; |
| 1225 | if (gsym->needs_dynamic_reloc(flags)) |
| 1226 | { |
| 1227 | if (target->may_need_copy_reloc(gsym)) |
| 1228 | { |
| 1229 | target->copy_reloc(symtab, layout, object, |
| 1230 | data_shndx, output_section, gsym, reloc); |
| 1231 | } |
| 1232 | else |
| 1233 | { |
| 1234 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
| 1235 | rel_dyn->add_global(gsym, r_type, output_section, object, |
| 1236 | data_shndx, reloc.get_r_offset()); |
| 1237 | } |
| 1238 | } |
| 1239 | } |
| 1240 | break; |
| 1241 | |
| 1242 | case elfcpp::R_386_GOT32: |
| 1243 | { |
| 1244 | // The symbol requires a GOT entry. |
| 1245 | Output_data_got<32, false>* got = target->got_section(symtab, layout); |
| 1246 | if (gsym->final_value_is_known()) |
| 1247 | got->add_global(gsym, GOT_TYPE_STANDARD); |
| 1248 | else |
| 1249 | { |
| 1250 | // If this symbol is not fully resolved, we need to add a |
| 1251 | // GOT entry with a dynamic relocation. |
| 1252 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
| 1253 | if (gsym->is_from_dynobj() |
| 1254 | || gsym->is_undefined() |
| 1255 | || gsym->is_preemptible()) |
| 1256 | got->add_global_with_rel(gsym, GOT_TYPE_STANDARD, |
| 1257 | rel_dyn, elfcpp::R_386_GLOB_DAT); |
| 1258 | else |
| 1259 | { |
| 1260 | if (got->add_global(gsym, GOT_TYPE_STANDARD)) |
| 1261 | rel_dyn->add_global_relative( |
| 1262 | gsym, elfcpp::R_386_RELATIVE, got, |
| 1263 | gsym->got_offset(GOT_TYPE_STANDARD)); |
| 1264 | } |
| 1265 | } |
| 1266 | } |
| 1267 | break; |
| 1268 | |
| 1269 | case elfcpp::R_386_PLT32: |
| 1270 | // If the symbol is fully resolved, this is just a PC32 reloc. |
| 1271 | // Otherwise we need a PLT entry. |
| 1272 | if (gsym->final_value_is_known()) |
| 1273 | break; |
| 1274 | // If building a shared library, we can also skip the PLT entry |
| 1275 | // if the symbol is defined in the output file and is protected |
| 1276 | // or hidden. |
| 1277 | if (gsym->is_defined() |
| 1278 | && !gsym->is_from_dynobj() |
| 1279 | && !gsym->is_preemptible()) |
| 1280 | break; |
| 1281 | target->make_plt_entry(symtab, layout, gsym); |
| 1282 | break; |
| 1283 | |
| 1284 | case elfcpp::R_386_GOTOFF: |
| 1285 | case elfcpp::R_386_GOTPC: |
| 1286 | // We need a GOT section. |
| 1287 | target->got_section(symtab, layout); |
| 1288 | break; |
| 1289 | |
| 1290 | // These are relocations which should only be seen by the |
| 1291 | // dynamic linker, and should never be seen here. |
| 1292 | case elfcpp::R_386_COPY: |
| 1293 | case elfcpp::R_386_GLOB_DAT: |
| 1294 | case elfcpp::R_386_JUMP_SLOT: |
| 1295 | case elfcpp::R_386_RELATIVE: |
| 1296 | case elfcpp::R_386_TLS_TPOFF: |
| 1297 | case elfcpp::R_386_TLS_DTPMOD32: |
| 1298 | case elfcpp::R_386_TLS_DTPOFF32: |
| 1299 | case elfcpp::R_386_TLS_TPOFF32: |
| 1300 | case elfcpp::R_386_TLS_DESC: |
| 1301 | gold_error(_("%s: unexpected reloc %u in object file"), |
| 1302 | object->name().c_str(), r_type); |
| 1303 | break; |
| 1304 | |
| 1305 | // These are initial tls relocs, which are expected when |
| 1306 | // linking. |
| 1307 | case elfcpp::R_386_TLS_GD: // Global-dynamic |
| 1308 | case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url) |
| 1309 | case elfcpp::R_386_TLS_DESC_CALL: |
| 1310 | case elfcpp::R_386_TLS_LDM: // Local-dynamic |
| 1311 | case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic |
| 1312 | case elfcpp::R_386_TLS_IE: // Initial-exec |
| 1313 | case elfcpp::R_386_TLS_IE_32: |
| 1314 | case elfcpp::R_386_TLS_GOTIE: |
| 1315 | case elfcpp::R_386_TLS_LE: // Local-exec |
| 1316 | case elfcpp::R_386_TLS_LE_32: |
| 1317 | { |
| 1318 | const bool is_final = gsym->final_value_is_known(); |
| 1319 | const tls::Tls_optimization optimized_type |
| 1320 | = Target_i386::optimize_tls_reloc(is_final, r_type); |
| 1321 | switch (r_type) |
| 1322 | { |
| 1323 | case elfcpp::R_386_TLS_GD: // Global-dynamic |
| 1324 | if (optimized_type == tls::TLSOPT_NONE) |
| 1325 | { |
| 1326 | // Create a pair of GOT entries for the module index and |
| 1327 | // dtv-relative offset. |
| 1328 | Output_data_got<32, false>* got |
| 1329 | = target->got_section(symtab, layout); |
| 1330 | got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR, |
| 1331 | target->rel_dyn_section(layout), |
| 1332 | elfcpp::R_386_TLS_DTPMOD32, |
| 1333 | elfcpp::R_386_TLS_DTPOFF32); |
| 1334 | } |
| 1335 | else if (optimized_type == tls::TLSOPT_TO_IE) |
| 1336 | { |
| 1337 | // Create a GOT entry for the tp-relative offset. |
| 1338 | Output_data_got<32, false>* got |
| 1339 | = target->got_section(symtab, layout); |
| 1340 | got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET, |
| 1341 | target->rel_dyn_section(layout), |
| 1342 | elfcpp::R_386_TLS_TPOFF); |
| 1343 | } |
| 1344 | else if (optimized_type != tls::TLSOPT_TO_LE) |
| 1345 | unsupported_reloc_global(object, r_type, gsym); |
| 1346 | break; |
| 1347 | |
| 1348 | case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (~oliva url) |
| 1349 | target->define_tls_base_symbol(symtab, layout); |
| 1350 | if (optimized_type == tls::TLSOPT_NONE) |
| 1351 | { |
| 1352 | // Create a double GOT entry with an R_386_TLS_DESC reloc. |
| 1353 | Output_data_got<32, false>* got |
| 1354 | = target->got_section(symtab, layout); |
| 1355 | got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC, |
| 1356 | target->rel_dyn_section(layout), |
| 1357 | elfcpp::R_386_TLS_DESC, 0); |
| 1358 | } |
| 1359 | else if (optimized_type == tls::TLSOPT_TO_IE) |
| 1360 | { |
| 1361 | // Create a GOT entry for the tp-relative offset. |
| 1362 | Output_data_got<32, false>* got |
| 1363 | = target->got_section(symtab, layout); |
| 1364 | got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET, |
| 1365 | target->rel_dyn_section(layout), |
| 1366 | elfcpp::R_386_TLS_TPOFF); |
| 1367 | } |
| 1368 | else if (optimized_type != tls::TLSOPT_TO_LE) |
| 1369 | unsupported_reloc_global(object, r_type, gsym); |
| 1370 | break; |
| 1371 | |
| 1372 | case elfcpp::R_386_TLS_DESC_CALL: |
| 1373 | break; |
| 1374 | |
| 1375 | case elfcpp::R_386_TLS_LDM: // Local-dynamic |
| 1376 | if (optimized_type == tls::TLSOPT_NONE) |
| 1377 | { |
| 1378 | // Create a GOT entry for the module index. |
| 1379 | target->got_mod_index_entry(symtab, layout, object); |
| 1380 | } |
| 1381 | else if (optimized_type != tls::TLSOPT_TO_LE) |
| 1382 | unsupported_reloc_global(object, r_type, gsym); |
| 1383 | break; |
| 1384 | |
| 1385 | case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic |
| 1386 | break; |
| 1387 | |
| 1388 | case elfcpp::R_386_TLS_IE: // Initial-exec |
| 1389 | case elfcpp::R_386_TLS_IE_32: |
| 1390 | case elfcpp::R_386_TLS_GOTIE: |
| 1391 | layout->set_has_static_tls(); |
| 1392 | if (optimized_type == tls::TLSOPT_NONE) |
| 1393 | { |
| 1394 | // For the R_386_TLS_IE relocation, we need to create a |
| 1395 | // dynamic relocation when building a shared library. |
| 1396 | if (r_type == elfcpp::R_386_TLS_IE |
| 1397 | && parameters->options().shared()) |
| 1398 | { |
| 1399 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
| 1400 | rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE, |
| 1401 | output_section, object, |
| 1402 | data_shndx, |
| 1403 | reloc.get_r_offset()); |
| 1404 | } |
| 1405 | // Create a GOT entry for the tp-relative offset. |
| 1406 | Output_data_got<32, false>* got |
| 1407 | = target->got_section(symtab, layout); |
| 1408 | unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32 |
| 1409 | ? elfcpp::R_386_TLS_TPOFF32 |
| 1410 | : elfcpp::R_386_TLS_TPOFF); |
| 1411 | unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32 |
| 1412 | ? GOT_TYPE_TLS_OFFSET |
| 1413 | : GOT_TYPE_TLS_NOFFSET); |
| 1414 | got->add_global_with_rel(gsym, got_type, |
| 1415 | target->rel_dyn_section(layout), |
| 1416 | dyn_r_type); |
| 1417 | } |
| 1418 | else if (optimized_type != tls::TLSOPT_TO_LE) |
| 1419 | unsupported_reloc_global(object, r_type, gsym); |
| 1420 | break; |
| 1421 | |
| 1422 | case elfcpp::R_386_TLS_LE: // Local-exec |
| 1423 | case elfcpp::R_386_TLS_LE_32: |
| 1424 | layout->set_has_static_tls(); |
| 1425 | if (parameters->options().shared()) |
| 1426 | { |
| 1427 | // We need to create a dynamic relocation. |
| 1428 | unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32 |
| 1429 | ? elfcpp::R_386_TLS_TPOFF32 |
| 1430 | : elfcpp::R_386_TLS_TPOFF); |
| 1431 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
| 1432 | rel_dyn->add_global(gsym, dyn_r_type, output_section, object, |
| 1433 | data_shndx, reloc.get_r_offset()); |
| 1434 | } |
| 1435 | break; |
| 1436 | |
| 1437 | default: |
| 1438 | gold_unreachable(); |
| 1439 | } |
| 1440 | } |
| 1441 | break; |
| 1442 | |
| 1443 | case elfcpp::R_386_32PLT: |
| 1444 | case elfcpp::R_386_TLS_GD_32: |
| 1445 | case elfcpp::R_386_TLS_GD_PUSH: |
| 1446 | case elfcpp::R_386_TLS_GD_CALL: |
| 1447 | case elfcpp::R_386_TLS_GD_POP: |
| 1448 | case elfcpp::R_386_TLS_LDM_32: |
| 1449 | case elfcpp::R_386_TLS_LDM_PUSH: |
| 1450 | case elfcpp::R_386_TLS_LDM_CALL: |
| 1451 | case elfcpp::R_386_TLS_LDM_POP: |
| 1452 | case elfcpp::R_386_USED_BY_INTEL_200: |
| 1453 | default: |
| 1454 | unsupported_reloc_global(object, r_type, gsym); |
| 1455 | break; |
| 1456 | } |
| 1457 | } |
| 1458 | |
| 1459 | // Scan relocations for a section. |
| 1460 | |
| 1461 | void |
| 1462 | Target_i386::scan_relocs(const General_options& options, |
| 1463 | Symbol_table* symtab, |
| 1464 | Layout* layout, |
| 1465 | Sized_relobj<32, false>* object, |
| 1466 | unsigned int data_shndx, |
| 1467 | unsigned int sh_type, |
| 1468 | const unsigned char* prelocs, |
| 1469 | size_t reloc_count, |
| 1470 | Output_section* output_section, |
| 1471 | bool needs_special_offset_handling, |
| 1472 | size_t local_symbol_count, |
| 1473 | const unsigned char* plocal_symbols) |
| 1474 | { |
| 1475 | if (sh_type == elfcpp::SHT_RELA) |
| 1476 | { |
| 1477 | gold_error(_("%s: unsupported RELA reloc section"), |
| 1478 | object->name().c_str()); |
| 1479 | return; |
| 1480 | } |
| 1481 | |
| 1482 | gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL, |
| 1483 | Target_i386::Scan>( |
| 1484 | options, |
| 1485 | symtab, |
| 1486 | layout, |
| 1487 | this, |
| 1488 | object, |
| 1489 | data_shndx, |
| 1490 | prelocs, |
| 1491 | reloc_count, |
| 1492 | output_section, |
| 1493 | needs_special_offset_handling, |
| 1494 | local_symbol_count, |
| 1495 | plocal_symbols); |
| 1496 | } |
| 1497 | |
| 1498 | // Finalize the sections. |
| 1499 | |
| 1500 | void |
| 1501 | Target_i386::do_finalize_sections(Layout* layout) |
| 1502 | { |
| 1503 | // Fill in some more dynamic tags. |
| 1504 | Output_data_dynamic* const odyn = layout->dynamic_data(); |
| 1505 | if (odyn != NULL) |
| 1506 | { |
| 1507 | if (this->got_plt_ != NULL) |
| 1508 | odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_); |
| 1509 | |
| 1510 | if (this->plt_ != NULL) |
| 1511 | { |
| 1512 | const Output_data* od = this->plt_->rel_plt(); |
| 1513 | odyn->add_section_size(elfcpp::DT_PLTRELSZ, od); |
| 1514 | odyn->add_section_address(elfcpp::DT_JMPREL, od); |
| 1515 | odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_REL); |
| 1516 | } |
| 1517 | |
| 1518 | if (this->rel_dyn_ != NULL) |
| 1519 | { |
| 1520 | const Output_data* od = this->rel_dyn_; |
| 1521 | odyn->add_section_address(elfcpp::DT_REL, od); |
| 1522 | odyn->add_section_size(elfcpp::DT_RELSZ, od); |
| 1523 | odyn->add_constant(elfcpp::DT_RELENT, |
| 1524 | elfcpp::Elf_sizes<32>::rel_size); |
| 1525 | } |
| 1526 | |
| 1527 | if (!parameters->options().shared()) |
| 1528 | { |
| 1529 | // The value of the DT_DEBUG tag is filled in by the dynamic |
| 1530 | // linker at run time, and used by the debugger. |
| 1531 | odyn->add_constant(elfcpp::DT_DEBUG, 0); |
| 1532 | } |
| 1533 | } |
| 1534 | |
| 1535 | // Emit any relocs we saved in an attempt to avoid generating COPY |
| 1536 | // relocs. |
| 1537 | if (this->copy_relocs_.any_saved_relocs()) |
| 1538 | this->copy_relocs_.emit(this->rel_dyn_section(layout)); |
| 1539 | } |
| 1540 | |
| 1541 | // Return whether a direct absolute static relocation needs to be applied. |
| 1542 | // In cases where Scan::local() or Scan::global() has created |
| 1543 | // a dynamic relocation other than R_386_RELATIVE, the addend |
| 1544 | // of the relocation is carried in the data, and we must not |
| 1545 | // apply the static relocation. |
| 1546 | |
| 1547 | inline bool |
| 1548 | Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol<32>* gsym, |
| 1549 | int ref_flags, |
| 1550 | bool is_32bit) |
| 1551 | { |
| 1552 | // For local symbols, we will have created a non-RELATIVE dynamic |
| 1553 | // relocation only if (a) the output is position independent, |
| 1554 | // (b) the relocation is absolute (not pc- or segment-relative), and |
| 1555 | // (c) the relocation is not 32 bits wide. |
| 1556 | if (gsym == NULL) |
| 1557 | return !(parameters->options().output_is_position_independent() |
| 1558 | && (ref_flags & Symbol::ABSOLUTE_REF) |
| 1559 | && !is_32bit); |
| 1560 | |
| 1561 | // For global symbols, we use the same helper routines used in the |
| 1562 | // scan pass. If we did not create a dynamic relocation, or if we |
| 1563 | // created a RELATIVE dynamic relocation, we should apply the static |
| 1564 | // relocation. |
| 1565 | bool has_dyn = gsym->needs_dynamic_reloc(ref_flags); |
| 1566 | bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF) |
| 1567 | && gsym->can_use_relative_reloc(ref_flags |
| 1568 | & Symbol::FUNCTION_CALL); |
| 1569 | return !has_dyn || is_rel; |
| 1570 | } |
| 1571 | |
| 1572 | // Perform a relocation. |
| 1573 | |
| 1574 | inline bool |
| 1575 | Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo, |
| 1576 | Target_i386* target, |
| 1577 | size_t relnum, |
| 1578 | const elfcpp::Rel<32, false>& rel, |
| 1579 | unsigned int r_type, |
| 1580 | const Sized_symbol<32>* gsym, |
| 1581 | const Symbol_value<32>* psymval, |
| 1582 | unsigned char* view, |
| 1583 | elfcpp::Elf_types<32>::Elf_Addr address, |
| 1584 | section_size_type view_size) |
| 1585 | { |
| 1586 | if (this->skip_call_tls_get_addr_) |
| 1587 | { |
| 1588 | if (r_type != elfcpp::R_386_PLT32 |
| 1589 | || gsym == NULL |
| 1590 | || strcmp(gsym->name(), "___tls_get_addr") != 0) |
| 1591 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
| 1592 | _("missing expected TLS relocation")); |
| 1593 | else |
| 1594 | { |
| 1595 | this->skip_call_tls_get_addr_ = false; |
| 1596 | return false; |
| 1597 | } |
| 1598 | } |
| 1599 | |
| 1600 | // Pick the value to use for symbols defined in shared objects. |
| 1601 | Symbol_value<32> symval; |
| 1602 | if (gsym != NULL |
| 1603 | && gsym->use_plt_offset(r_type == elfcpp::R_386_PC8 |
| 1604 | || r_type == elfcpp::R_386_PC16 |
| 1605 | || r_type == elfcpp::R_386_PC32)) |
| 1606 | { |
| 1607 | symval.set_output_value(target->plt_section()->address() |
| 1608 | + gsym->plt_offset()); |
| 1609 | psymval = &symval; |
| 1610 | } |
| 1611 | |
| 1612 | const Sized_relobj<32, false>* object = relinfo->object; |
| 1613 | |
| 1614 | // Get the GOT offset if needed. |
| 1615 | // The GOT pointer points to the end of the GOT section. |
| 1616 | // We need to subtract the size of the GOT section to get |
| 1617 | // the actual offset to use in the relocation. |
| 1618 | bool have_got_offset = false; |
| 1619 | unsigned int got_offset = 0; |
| 1620 | switch (r_type) |
| 1621 | { |
| 1622 | case elfcpp::R_386_GOT32: |
| 1623 | if (gsym != NULL) |
| 1624 | { |
| 1625 | gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD)); |
| 1626 | got_offset = (gsym->got_offset(GOT_TYPE_STANDARD) |
| 1627 | - target->got_size()); |
| 1628 | } |
| 1629 | else |
| 1630 | { |
| 1631 | unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info()); |
| 1632 | gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD)); |
| 1633 | got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD) |
| 1634 | - target->got_size()); |
| 1635 | } |
| 1636 | have_got_offset = true; |
| 1637 | break; |
| 1638 | |
| 1639 | default: |
| 1640 | break; |
| 1641 | } |
| 1642 | |
| 1643 | switch (r_type) |
| 1644 | { |
| 1645 | case elfcpp::R_386_NONE: |
| 1646 | case elfcpp::R_386_GNU_VTINHERIT: |
| 1647 | case elfcpp::R_386_GNU_VTENTRY: |
| 1648 | break; |
| 1649 | |
| 1650 | case elfcpp::R_386_32: |
| 1651 | if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true)) |
| 1652 | Relocate_functions<32, false>::rel32(view, object, psymval); |
| 1653 | break; |
| 1654 | |
| 1655 | case elfcpp::R_386_PC32: |
| 1656 | { |
| 1657 | int ref_flags = Symbol::NON_PIC_REF; |
| 1658 | if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC) |
| 1659 | ref_flags |= Symbol::FUNCTION_CALL; |
| 1660 | if (should_apply_static_reloc(gsym, ref_flags, true)) |
| 1661 | Relocate_functions<32, false>::pcrel32(view, object, psymval, address); |
| 1662 | } |
| 1663 | break; |
| 1664 | |
| 1665 | case elfcpp::R_386_16: |
| 1666 | if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false)) |
| 1667 | Relocate_functions<32, false>::rel16(view, object, psymval); |
| 1668 | break; |
| 1669 | |
| 1670 | case elfcpp::R_386_PC16: |
| 1671 | { |
| 1672 | int ref_flags = Symbol::NON_PIC_REF; |
| 1673 | if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC) |
| 1674 | ref_flags |= Symbol::FUNCTION_CALL; |
| 1675 | if (should_apply_static_reloc(gsym, ref_flags, false)) |
| 1676 | Relocate_functions<32, false>::pcrel16(view, object, psymval, address); |
| 1677 | } |
| 1678 | break; |
| 1679 | |
| 1680 | case elfcpp::R_386_8: |
| 1681 | if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false)) |
| 1682 | Relocate_functions<32, false>::rel8(view, object, psymval); |
| 1683 | break; |
| 1684 | |
| 1685 | case elfcpp::R_386_PC8: |
| 1686 | { |
| 1687 | int ref_flags = Symbol::NON_PIC_REF; |
| 1688 | if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC) |
| 1689 | ref_flags |= Symbol::FUNCTION_CALL; |
| 1690 | if (should_apply_static_reloc(gsym, ref_flags, false)) |
| 1691 | Relocate_functions<32, false>::pcrel8(view, object, psymval, address); |
| 1692 | } |
| 1693 | break; |
| 1694 | |
| 1695 | case elfcpp::R_386_PLT32: |
| 1696 | gold_assert(gsym == NULL |
| 1697 | || gsym->has_plt_offset() |
| 1698 | || gsym->final_value_is_known() |
| 1699 | || (gsym->is_defined() |
| 1700 | && !gsym->is_from_dynobj() |
| 1701 | && !gsym->is_preemptible())); |
| 1702 | Relocate_functions<32, false>::pcrel32(view, object, psymval, address); |
| 1703 | break; |
| 1704 | |
| 1705 | case elfcpp::R_386_GOT32: |
| 1706 | gold_assert(have_got_offset); |
| 1707 | Relocate_functions<32, false>::rel32(view, got_offset); |
| 1708 | break; |
| 1709 | |
| 1710 | case elfcpp::R_386_GOTOFF: |
| 1711 | { |
| 1712 | elfcpp::Elf_types<32>::Elf_Addr value; |
| 1713 | value = (psymval->value(object, 0) |
| 1714 | - target->got_plt_section()->address()); |
| 1715 | Relocate_functions<32, false>::rel32(view, value); |
| 1716 | } |
| 1717 | break; |
| 1718 | |
| 1719 | case elfcpp::R_386_GOTPC: |
| 1720 | { |
| 1721 | elfcpp::Elf_types<32>::Elf_Addr value; |
| 1722 | value = target->got_plt_section()->address(); |
| 1723 | Relocate_functions<32, false>::pcrel32(view, value, address); |
| 1724 | } |
| 1725 | break; |
| 1726 | |
| 1727 | case elfcpp::R_386_COPY: |
| 1728 | case elfcpp::R_386_GLOB_DAT: |
| 1729 | case elfcpp::R_386_JUMP_SLOT: |
| 1730 | case elfcpp::R_386_RELATIVE: |
| 1731 | // These are outstanding tls relocs, which are unexpected when |
| 1732 | // linking. |
| 1733 | case elfcpp::R_386_TLS_TPOFF: |
| 1734 | case elfcpp::R_386_TLS_DTPMOD32: |
| 1735 | case elfcpp::R_386_TLS_DTPOFF32: |
| 1736 | case elfcpp::R_386_TLS_TPOFF32: |
| 1737 | case elfcpp::R_386_TLS_DESC: |
| 1738 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
| 1739 | _("unexpected reloc %u in object file"), |
| 1740 | r_type); |
| 1741 | break; |
| 1742 | |
| 1743 | // These are initial tls relocs, which are expected when |
| 1744 | // linking. |
| 1745 | case elfcpp::R_386_TLS_GD: // Global-dynamic |
| 1746 | case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url) |
| 1747 | case elfcpp::R_386_TLS_DESC_CALL: |
| 1748 | case elfcpp::R_386_TLS_LDM: // Local-dynamic |
| 1749 | case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic |
| 1750 | case elfcpp::R_386_TLS_IE: // Initial-exec |
| 1751 | case elfcpp::R_386_TLS_IE_32: |
| 1752 | case elfcpp::R_386_TLS_GOTIE: |
| 1753 | case elfcpp::R_386_TLS_LE: // Local-exec |
| 1754 | case elfcpp::R_386_TLS_LE_32: |
| 1755 | this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval, |
| 1756 | view, address, view_size); |
| 1757 | break; |
| 1758 | |
| 1759 | case elfcpp::R_386_32PLT: |
| 1760 | case elfcpp::R_386_TLS_GD_32: |
| 1761 | case elfcpp::R_386_TLS_GD_PUSH: |
| 1762 | case elfcpp::R_386_TLS_GD_CALL: |
| 1763 | case elfcpp::R_386_TLS_GD_POP: |
| 1764 | case elfcpp::R_386_TLS_LDM_32: |
| 1765 | case elfcpp::R_386_TLS_LDM_PUSH: |
| 1766 | case elfcpp::R_386_TLS_LDM_CALL: |
| 1767 | case elfcpp::R_386_TLS_LDM_POP: |
| 1768 | case elfcpp::R_386_USED_BY_INTEL_200: |
| 1769 | default: |
| 1770 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
| 1771 | _("unsupported reloc %u"), |
| 1772 | r_type); |
| 1773 | break; |
| 1774 | } |
| 1775 | |
| 1776 | return true; |
| 1777 | } |
| 1778 | |
| 1779 | // Perform a TLS relocation. |
| 1780 | |
| 1781 | inline void |
| 1782 | Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo, |
| 1783 | Target_i386* target, |
| 1784 | size_t relnum, |
| 1785 | const elfcpp::Rel<32, false>& rel, |
| 1786 | unsigned int r_type, |
| 1787 | const Sized_symbol<32>* gsym, |
| 1788 | const Symbol_value<32>* psymval, |
| 1789 | unsigned char* view, |
| 1790 | elfcpp::Elf_types<32>::Elf_Addr, |
| 1791 | section_size_type view_size) |
| 1792 | { |
| 1793 | Output_segment* tls_segment = relinfo->layout->tls_segment(); |
| 1794 | |
| 1795 | const Sized_relobj<32, false>* object = relinfo->object; |
| 1796 | |
| 1797 | elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0); |
| 1798 | |
| 1799 | const bool is_final = |
| 1800 | (gsym == NULL |
| 1801 | ? !parameters->options().output_is_position_independent() |
| 1802 | : gsym->final_value_is_known()); |
| 1803 | const tls::Tls_optimization optimized_type |
| 1804 | = Target_i386::optimize_tls_reloc(is_final, r_type); |
| 1805 | switch (r_type) |
| 1806 | { |
| 1807 | case elfcpp::R_386_TLS_GD: // Global-dynamic |
| 1808 | if (optimized_type == tls::TLSOPT_TO_LE) |
| 1809 | { |
| 1810 | gold_assert(tls_segment != NULL); |
| 1811 | this->tls_gd_to_le(relinfo, relnum, tls_segment, |
| 1812 | rel, r_type, value, view, |
| 1813 | view_size); |
| 1814 | break; |
| 1815 | } |
| 1816 | else |
| 1817 | { |
| 1818 | unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE |
| 1819 | ? GOT_TYPE_TLS_NOFFSET |
| 1820 | : GOT_TYPE_TLS_PAIR); |
| 1821 | unsigned int got_offset; |
| 1822 | if (gsym != NULL) |
| 1823 | { |
| 1824 | gold_assert(gsym->has_got_offset(got_type)); |
| 1825 | got_offset = gsym->got_offset(got_type) - target->got_size(); |
| 1826 | } |
| 1827 | else |
| 1828 | { |
| 1829 | unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info()); |
| 1830 | gold_assert(object->local_has_got_offset(r_sym, got_type)); |
| 1831 | got_offset = (object->local_got_offset(r_sym, got_type) |
| 1832 | - target->got_size()); |
| 1833 | } |
| 1834 | if (optimized_type == tls::TLSOPT_TO_IE) |
| 1835 | { |
| 1836 | gold_assert(tls_segment != NULL); |
| 1837 | this->tls_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type, |
| 1838 | got_offset, view, view_size); |
| 1839 | break; |
| 1840 | } |
| 1841 | else if (optimized_type == tls::TLSOPT_NONE) |
| 1842 | { |
| 1843 | // Relocate the field with the offset of the pair of GOT |
| 1844 | // entries. |
| 1845 | Relocate_functions<32, false>::rel32(view, got_offset); |
| 1846 | break; |
| 1847 | } |
| 1848 | } |
| 1849 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
| 1850 | _("unsupported reloc %u"), |
| 1851 | r_type); |
| 1852 | break; |
| 1853 | |
| 1854 | case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url) |
| 1855 | case elfcpp::R_386_TLS_DESC_CALL: |
| 1856 | this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU; |
| 1857 | if (optimized_type == tls::TLSOPT_TO_LE) |
| 1858 | { |
| 1859 | gold_assert(tls_segment != NULL); |
| 1860 | this->tls_desc_gd_to_le(relinfo, relnum, tls_segment, |
| 1861 | rel, r_type, value, view, |
| 1862 | view_size); |
| 1863 | break; |
| 1864 | } |
| 1865 | else |
| 1866 | { |
| 1867 | unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE |
| 1868 | ? GOT_TYPE_TLS_NOFFSET |
| 1869 | : GOT_TYPE_TLS_DESC); |
| 1870 | unsigned int got_offset; |
| 1871 | if (gsym != NULL) |
| 1872 | { |
| 1873 | gold_assert(gsym->has_got_offset(got_type)); |
| 1874 | got_offset = gsym->got_offset(got_type) - target->got_size(); |
| 1875 | } |
| 1876 | else |
| 1877 | { |
| 1878 | unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info()); |
| 1879 | gold_assert(object->local_has_got_offset(r_sym, got_type)); |
| 1880 | got_offset = (object->local_got_offset(r_sym, got_type) |
| 1881 | - target->got_size()); |
| 1882 | } |
| 1883 | if (optimized_type == tls::TLSOPT_TO_IE) |
| 1884 | { |
| 1885 | gold_assert(tls_segment != NULL); |
| 1886 | this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type, |
| 1887 | got_offset, view, view_size); |
| 1888 | break; |
| 1889 | } |
| 1890 | else if (optimized_type == tls::TLSOPT_NONE) |
| 1891 | { |
| 1892 | if (r_type == elfcpp::R_386_TLS_GOTDESC) |
| 1893 | { |
| 1894 | // Relocate the field with the offset of the pair of GOT |
| 1895 | // entries. |
| 1896 | Relocate_functions<32, false>::rel32(view, got_offset); |
| 1897 | } |
| 1898 | break; |
| 1899 | } |
| 1900 | } |
| 1901 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
| 1902 | _("unsupported reloc %u"), |
| 1903 | r_type); |
| 1904 | break; |
| 1905 | |
| 1906 | case elfcpp::R_386_TLS_LDM: // Local-dynamic |
| 1907 | if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN) |
| 1908 | { |
| 1909 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
| 1910 | _("both SUN and GNU model " |
| 1911 | "TLS relocations")); |
| 1912 | break; |
| 1913 | } |
| 1914 | this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU; |
| 1915 | if (optimized_type == tls::TLSOPT_TO_LE) |
| 1916 | { |
| 1917 | gold_assert(tls_segment != NULL); |
| 1918 | this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, r_type, |
| 1919 | value, view, view_size); |
| 1920 | break; |
| 1921 | } |
| 1922 | else if (optimized_type == tls::TLSOPT_NONE) |
| 1923 | { |
| 1924 | // Relocate the field with the offset of the GOT entry for |
| 1925 | // the module index. |
| 1926 | unsigned int got_offset; |
| 1927 | got_offset = (target->got_mod_index_entry(NULL, NULL, NULL) |
| 1928 | - target->got_size()); |
| 1929 | Relocate_functions<32, false>::rel32(view, got_offset); |
| 1930 | break; |
| 1931 | } |
| 1932 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
| 1933 | _("unsupported reloc %u"), |
| 1934 | r_type); |
| 1935 | break; |
| 1936 | |
| 1937 | case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic |
| 1938 | // This reloc can appear in debugging sections, in which case we |
| 1939 | // won't see the TLS_LDM reloc. The local_dynamic_type field |
| 1940 | // tells us this. |
| 1941 | if (optimized_type == tls::TLSOPT_TO_LE |
| 1942 | && this->local_dynamic_type_ != LOCAL_DYNAMIC_NONE) |
| 1943 | { |
| 1944 | gold_assert(tls_segment != NULL); |
| 1945 | value -= tls_segment->memsz(); |
| 1946 | } |
| 1947 | Relocate_functions<32, false>::rel32(view, value); |
| 1948 | break; |
| 1949 | |
| 1950 | case elfcpp::R_386_TLS_IE: // Initial-exec |
| 1951 | case elfcpp::R_386_TLS_GOTIE: |
| 1952 | case elfcpp::R_386_TLS_IE_32: |
| 1953 | if (optimized_type == tls::TLSOPT_TO_LE) |
| 1954 | { |
| 1955 | gold_assert(tls_segment != NULL); |
| 1956 | Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment, |
| 1957 | rel, r_type, value, view, |
| 1958 | view_size); |
| 1959 | break; |
| 1960 | } |
| 1961 | else if (optimized_type == tls::TLSOPT_NONE) |
| 1962 | { |
| 1963 | // Relocate the field with the offset of the GOT entry for |
| 1964 | // the tp-relative offset of the symbol. |
| 1965 | unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32 |
| 1966 | ? GOT_TYPE_TLS_OFFSET |
| 1967 | : GOT_TYPE_TLS_NOFFSET); |
| 1968 | unsigned int got_offset; |
| 1969 | if (gsym != NULL) |
| 1970 | { |
| 1971 | gold_assert(gsym->has_got_offset(got_type)); |
| 1972 | got_offset = gsym->got_offset(got_type); |
| 1973 | } |
| 1974 | else |
| 1975 | { |
| 1976 | unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info()); |
| 1977 | gold_assert(object->local_has_got_offset(r_sym, got_type)); |
| 1978 | got_offset = object->local_got_offset(r_sym, got_type); |
| 1979 | } |
| 1980 | // For the R_386_TLS_IE relocation, we need to apply the |
| 1981 | // absolute address of the GOT entry. |
| 1982 | if (r_type == elfcpp::R_386_TLS_IE) |
| 1983 | got_offset += target->got_plt_section()->address(); |
| 1984 | // All GOT offsets are relative to the end of the GOT. |
| 1985 | got_offset -= target->got_size(); |
| 1986 | Relocate_functions<32, false>::rel32(view, got_offset); |
| 1987 | break; |
| 1988 | } |
| 1989 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
| 1990 | _("unsupported reloc %u"), |
| 1991 | r_type); |
| 1992 | break; |
| 1993 | |
| 1994 | case elfcpp::R_386_TLS_LE: // Local-exec |
| 1995 | // If we're creating a shared library, a dynamic relocation will |
| 1996 | // have been created for this location, so do not apply it now. |
| 1997 | if (!parameters->options().shared()) |
| 1998 | { |
| 1999 | gold_assert(tls_segment != NULL); |
| 2000 | value -= tls_segment->memsz(); |
| 2001 | Relocate_functions<32, false>::rel32(view, value); |
| 2002 | } |
| 2003 | break; |
| 2004 | |
| 2005 | case elfcpp::R_386_TLS_LE_32: |
| 2006 | // If we're creating a shared library, a dynamic relocation will |
| 2007 | // have been created for this location, so do not apply it now. |
| 2008 | if (!parameters->options().shared()) |
| 2009 | { |
| 2010 | gold_assert(tls_segment != NULL); |
| 2011 | value = tls_segment->memsz() - value; |
| 2012 | Relocate_functions<32, false>::rel32(view, value); |
| 2013 | } |
| 2014 | break; |
| 2015 | } |
| 2016 | } |
| 2017 | |
| 2018 | // Do a relocation in which we convert a TLS General-Dynamic to a |
| 2019 | // Local-Exec. |
| 2020 | |
| 2021 | inline void |
| 2022 | Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo, |
| 2023 | size_t relnum, |
| 2024 | Output_segment* tls_segment, |
| 2025 | const elfcpp::Rel<32, false>& rel, |
| 2026 | unsigned int, |
| 2027 | elfcpp::Elf_types<32>::Elf_Addr value, |
| 2028 | unsigned char* view, |
| 2029 | section_size_type view_size) |
| 2030 | { |
| 2031 | // leal foo(,%reg,1),%eax; call ___tls_get_addr |
| 2032 | // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax |
| 2033 | // leal foo(%reg),%eax; call ___tls_get_addr |
| 2034 | // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax |
| 2035 | |
| 2036 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2); |
| 2037 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9); |
| 2038 | |
| 2039 | unsigned char op1 = view[-1]; |
| 2040 | unsigned char op2 = view[-2]; |
| 2041 | |
| 2042 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
| 2043 | op2 == 0x8d || op2 == 0x04); |
| 2044 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8); |
| 2045 | |
| 2046 | int roff = 5; |
| 2047 | |
| 2048 | if (op2 == 0x04) |
| 2049 | { |
| 2050 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3); |
| 2051 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d); |
| 2052 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
| 2053 | ((op1 & 0xc7) == 0x05 && op1 != (4 << 3))); |
| 2054 | memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12); |
| 2055 | } |
| 2056 | else |
| 2057 | { |
| 2058 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
| 2059 | (op1 & 0xf8) == 0x80 && (op1 & 7) != 4); |
| 2060 | if (rel.get_r_offset() + 9 < view_size |
| 2061 | && view[9] == 0x90) |
| 2062 | { |
| 2063 | // There is a trailing nop. Use the size byte subl. |
| 2064 | memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12); |
| 2065 | roff = 6; |
| 2066 | } |
| 2067 | else |
| 2068 | { |
| 2069 | // Use the five byte subl. |
| 2070 | memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11); |
| 2071 | } |
| 2072 | } |
| 2073 | |
| 2074 | value = tls_segment->memsz() - value; |
| 2075 | Relocate_functions<32, false>::rel32(view + roff, value); |
| 2076 | |
| 2077 | // The next reloc should be a PLT32 reloc against __tls_get_addr. |
| 2078 | // We can skip it. |
| 2079 | this->skip_call_tls_get_addr_ = true; |
| 2080 | } |
| 2081 | |
| 2082 | // Do a relocation in which we convert a TLS General-Dynamic to an |
| 2083 | // Initial-Exec. |
| 2084 | |
| 2085 | inline void |
| 2086 | Target_i386::Relocate::tls_gd_to_ie(const Relocate_info<32, false>* relinfo, |
| 2087 | size_t relnum, |
| 2088 | Output_segment*, |
| 2089 | const elfcpp::Rel<32, false>& rel, |
| 2090 | unsigned int, |
| 2091 | elfcpp::Elf_types<32>::Elf_Addr value, |
| 2092 | unsigned char* view, |
| 2093 | section_size_type view_size) |
| 2094 | { |
| 2095 | // leal foo(,%ebx,1),%eax; call ___tls_get_addr |
| 2096 | // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax |
| 2097 | |
| 2098 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2); |
| 2099 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9); |
| 2100 | |
| 2101 | unsigned char op1 = view[-1]; |
| 2102 | unsigned char op2 = view[-2]; |
| 2103 | |
| 2104 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
| 2105 | op2 == 0x8d || op2 == 0x04); |
| 2106 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8); |
| 2107 | |
| 2108 | int roff = 5; |
| 2109 | |
| 2110 | // FIXME: For now, support only the first (SIB) form. |
| 2111 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), op2 == 0x04); |
| 2112 | |
| 2113 | if (op2 == 0x04) |
| 2114 | { |
| 2115 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3); |
| 2116 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d); |
| 2117 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
| 2118 | ((op1 & 0xc7) == 0x05 && op1 != (4 << 3))); |
| 2119 | memcpy(view - 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12); |
| 2120 | } |
| 2121 | else |
| 2122 | { |
| 2123 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
| 2124 | (op1 & 0xf8) == 0x80 && (op1 & 7) != 4); |
| 2125 | if (rel.get_r_offset() + 9 < view_size |
| 2126 | && view[9] == 0x90) |
| 2127 | { |
| 2128 | // FIXME: This is not the right instruction sequence. |
| 2129 | // There is a trailing nop. Use the size byte subl. |
| 2130 | memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12); |
| 2131 | roff = 6; |
| 2132 | } |
| 2133 | else |
| 2134 | { |
| 2135 | // FIXME: This is not the right instruction sequence. |
| 2136 | // Use the five byte subl. |
| 2137 | memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11); |
| 2138 | } |
| 2139 | } |
| 2140 | |
| 2141 | Relocate_functions<32, false>::rel32(view + roff, value); |
| 2142 | |
| 2143 | // The next reloc should be a PLT32 reloc against __tls_get_addr. |
| 2144 | // We can skip it. |
| 2145 | this->skip_call_tls_get_addr_ = true; |
| 2146 | } |
| 2147 | |
| 2148 | // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL |
| 2149 | // General-Dynamic to a Local-Exec. |
| 2150 | |
| 2151 | inline void |
| 2152 | Target_i386::Relocate::tls_desc_gd_to_le( |
| 2153 | const Relocate_info<32, false>* relinfo, |
| 2154 | size_t relnum, |
| 2155 | Output_segment* tls_segment, |
| 2156 | const elfcpp::Rel<32, false>& rel, |
| 2157 | unsigned int r_type, |
| 2158 | elfcpp::Elf_types<32>::Elf_Addr value, |
| 2159 | unsigned char* view, |
| 2160 | section_size_type view_size) |
| 2161 | { |
| 2162 | if (r_type == elfcpp::R_386_TLS_GOTDESC) |
| 2163 | { |
| 2164 | // leal foo@TLSDESC(%ebx), %eax |
| 2165 | // ==> leal foo@NTPOFF, %eax |
| 2166 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2); |
| 2167 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4); |
| 2168 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
| 2169 | view[-2] == 0x8d && view[-1] == 0x83); |
| 2170 | view[-1] = 0x05; |
| 2171 | value -= tls_segment->memsz(); |
| 2172 | Relocate_functions<32, false>::rel32(view, value); |
| 2173 | } |
| 2174 | else |
| 2175 | { |
| 2176 | // call *foo@TLSCALL(%eax) |
| 2177 | // ==> nop; nop |
| 2178 | gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL); |
| 2179 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2); |
| 2180 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
| 2181 | view[0] == 0xff && view[1] == 0x10); |
| 2182 | view[0] = 0x66; |
| 2183 | view[1] = 0x90; |
| 2184 | } |
| 2185 | } |
| 2186 | |
| 2187 | // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL |
| 2188 | // General-Dynamic to an Initial-Exec. |
| 2189 | |
| 2190 | inline void |
| 2191 | Target_i386::Relocate::tls_desc_gd_to_ie( |
| 2192 | const Relocate_info<32, false>* relinfo, |
| 2193 | size_t relnum, |
| 2194 | Output_segment*, |
| 2195 | const elfcpp::Rel<32, false>& rel, |
| 2196 | unsigned int r_type, |
| 2197 | elfcpp::Elf_types<32>::Elf_Addr value, |
| 2198 | unsigned char* view, |
| 2199 | section_size_type view_size) |
| 2200 | { |
| 2201 | if (r_type == elfcpp::R_386_TLS_GOTDESC) |
| 2202 | { |
| 2203 | // leal foo@TLSDESC(%ebx), %eax |
| 2204 | // ==> movl foo@GOTNTPOFF(%ebx), %eax |
| 2205 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2); |
| 2206 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4); |
| 2207 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
| 2208 | view[-2] == 0x8d && view[-1] == 0x83); |
| 2209 | view[-2] = 0x8b; |
| 2210 | Relocate_functions<32, false>::rel32(view, value); |
| 2211 | } |
| 2212 | else |
| 2213 | { |
| 2214 | // call *foo@TLSCALL(%eax) |
| 2215 | // ==> nop; nop |
| 2216 | gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL); |
| 2217 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2); |
| 2218 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
| 2219 | view[0] == 0xff && view[1] == 0x10); |
| 2220 | view[0] = 0x66; |
| 2221 | view[1] = 0x90; |
| 2222 | } |
| 2223 | } |
| 2224 | |
| 2225 | // Do a relocation in which we convert a TLS Local-Dynamic to a |
| 2226 | // Local-Exec. |
| 2227 | |
| 2228 | inline void |
| 2229 | Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo, |
| 2230 | size_t relnum, |
| 2231 | Output_segment*, |
| 2232 | const elfcpp::Rel<32, false>& rel, |
| 2233 | unsigned int, |
| 2234 | elfcpp::Elf_types<32>::Elf_Addr, |
| 2235 | unsigned char* view, |
| 2236 | section_size_type view_size) |
| 2237 | { |
| 2238 | // leal foo(%reg), %eax; call ___tls_get_addr |
| 2239 | // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi |
| 2240 | |
| 2241 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2); |
| 2242 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9); |
| 2243 | |
| 2244 | // FIXME: Does this test really always pass? |
| 2245 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
| 2246 | view[-2] == 0x8d && view[-1] == 0x83); |
| 2247 | |
| 2248 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8); |
| 2249 | |
| 2250 | memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11); |
| 2251 | |
| 2252 | // The next reloc should be a PLT32 reloc against __tls_get_addr. |
| 2253 | // We can skip it. |
| 2254 | this->skip_call_tls_get_addr_ = true; |
| 2255 | } |
| 2256 | |
| 2257 | // Do a relocation in which we convert a TLS Initial-Exec to a |
| 2258 | // Local-Exec. |
| 2259 | |
| 2260 | inline void |
| 2261 | Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo, |
| 2262 | size_t relnum, |
| 2263 | Output_segment* tls_segment, |
| 2264 | const elfcpp::Rel<32, false>& rel, |
| 2265 | unsigned int r_type, |
| 2266 | elfcpp::Elf_types<32>::Elf_Addr value, |
| 2267 | unsigned char* view, |
| 2268 | section_size_type view_size) |
| 2269 | { |
| 2270 | // We have to actually change the instructions, which means that we |
| 2271 | // need to examine the opcodes to figure out which instruction we |
| 2272 | // are looking at. |
| 2273 | if (r_type == elfcpp::R_386_TLS_IE) |
| 2274 | { |
| 2275 | // movl %gs:XX,%eax ==> movl $YY,%eax |
| 2276 | // movl %gs:XX,%reg ==> movl $YY,%reg |
| 2277 | // addl %gs:XX,%reg ==> addl $YY,%reg |
| 2278 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -1); |
| 2279 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4); |
| 2280 | |
| 2281 | unsigned char op1 = view[-1]; |
| 2282 | if (op1 == 0xa1) |
| 2283 | { |
| 2284 | // movl XX,%eax ==> movl $YY,%eax |
| 2285 | view[-1] = 0xb8; |
| 2286 | } |
| 2287 | else |
| 2288 | { |
| 2289 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2); |
| 2290 | |
| 2291 | unsigned char op2 = view[-2]; |
| 2292 | if (op2 == 0x8b) |
| 2293 | { |
| 2294 | // movl XX,%reg ==> movl $YY,%reg |
| 2295 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
| 2296 | (op1 & 0xc7) == 0x05); |
| 2297 | view[-2] = 0xc7; |
| 2298 | view[-1] = 0xc0 | ((op1 >> 3) & 7); |
| 2299 | } |
| 2300 | else if (op2 == 0x03) |
| 2301 | { |
| 2302 | // addl XX,%reg ==> addl $YY,%reg |
| 2303 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
| 2304 | (op1 & 0xc7) == 0x05); |
| 2305 | view[-2] = 0x81; |
| 2306 | view[-1] = 0xc0 | ((op1 >> 3) & 7); |
| 2307 | } |
| 2308 | else |
| 2309 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0); |
| 2310 | } |
| 2311 | } |
| 2312 | else |
| 2313 | { |
| 2314 | // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2 |
| 2315 | // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2 |
| 2316 | // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2 |
| 2317 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2); |
| 2318 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4); |
| 2319 | |
| 2320 | unsigned char op1 = view[-1]; |
| 2321 | unsigned char op2 = view[-2]; |
| 2322 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
| 2323 | (op1 & 0xc0) == 0x80 && (op1 & 7) != 4); |
| 2324 | if (op2 == 0x8b) |
| 2325 | { |
| 2326 | // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2 |
| 2327 | view[-2] = 0xc7; |
| 2328 | view[-1] = 0xc0 | ((op1 >> 3) & 7); |
| 2329 | } |
| 2330 | else if (op2 == 0x2b) |
| 2331 | { |
| 2332 | // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2 |
| 2333 | view[-2] = 0x81; |
| 2334 | view[-1] = 0xe8 | ((op1 >> 3) & 7); |
| 2335 | } |
| 2336 | else if (op2 == 0x03) |
| 2337 | { |
| 2338 | // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2 |
| 2339 | view[-2] = 0x81; |
| 2340 | view[-1] = 0xc0 | ((op1 >> 3) & 7); |
| 2341 | } |
| 2342 | else |
| 2343 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0); |
| 2344 | } |
| 2345 | |
| 2346 | value = tls_segment->memsz() - value; |
| 2347 | if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE) |
| 2348 | value = - value; |
| 2349 | |
| 2350 | Relocate_functions<32, false>::rel32(view, value); |
| 2351 | } |
| 2352 | |
| 2353 | // Relocate section data. |
| 2354 | |
| 2355 | void |
| 2356 | Target_i386::relocate_section(const Relocate_info<32, false>* relinfo, |
| 2357 | unsigned int sh_type, |
| 2358 | const unsigned char* prelocs, |
| 2359 | size_t reloc_count, |
| 2360 | Output_section* output_section, |
| 2361 | bool needs_special_offset_handling, |
| 2362 | unsigned char* view, |
| 2363 | elfcpp::Elf_types<32>::Elf_Addr address, |
| 2364 | section_size_type view_size) |
| 2365 | { |
| 2366 | gold_assert(sh_type == elfcpp::SHT_REL); |
| 2367 | |
| 2368 | gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL, |
| 2369 | Target_i386::Relocate>( |
| 2370 | relinfo, |
| 2371 | this, |
| 2372 | prelocs, |
| 2373 | reloc_count, |
| 2374 | output_section, |
| 2375 | needs_special_offset_handling, |
| 2376 | view, |
| 2377 | address, |
| 2378 | view_size); |
| 2379 | } |
| 2380 | |
| 2381 | // Return the size of a relocation while scanning during a relocatable |
| 2382 | // link. |
| 2383 | |
| 2384 | unsigned int |
| 2385 | Target_i386::Relocatable_size_for_reloc::get_size_for_reloc( |
| 2386 | unsigned int r_type, |
| 2387 | Relobj* object) |
| 2388 | { |
| 2389 | switch (r_type) |
| 2390 | { |
| 2391 | case elfcpp::R_386_NONE: |
| 2392 | case elfcpp::R_386_GNU_VTINHERIT: |
| 2393 | case elfcpp::R_386_GNU_VTENTRY: |
| 2394 | case elfcpp::R_386_TLS_GD: // Global-dynamic |
| 2395 | case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url) |
| 2396 | case elfcpp::R_386_TLS_DESC_CALL: |
| 2397 | case elfcpp::R_386_TLS_LDM: // Local-dynamic |
| 2398 | case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic |
| 2399 | case elfcpp::R_386_TLS_IE: // Initial-exec |
| 2400 | case elfcpp::R_386_TLS_IE_32: |
| 2401 | case elfcpp::R_386_TLS_GOTIE: |
| 2402 | case elfcpp::R_386_TLS_LE: // Local-exec |
| 2403 | case elfcpp::R_386_TLS_LE_32: |
| 2404 | return 0; |
| 2405 | |
| 2406 | case elfcpp::R_386_32: |
| 2407 | case elfcpp::R_386_PC32: |
| 2408 | case elfcpp::R_386_GOT32: |
| 2409 | case elfcpp::R_386_PLT32: |
| 2410 | case elfcpp::R_386_GOTOFF: |
| 2411 | case elfcpp::R_386_GOTPC: |
| 2412 | return 4; |
| 2413 | |
| 2414 | case elfcpp::R_386_16: |
| 2415 | case elfcpp::R_386_PC16: |
| 2416 | return 2; |
| 2417 | |
| 2418 | case elfcpp::R_386_8: |
| 2419 | case elfcpp::R_386_PC8: |
| 2420 | return 1; |
| 2421 | |
| 2422 | // These are relocations which should only be seen by the |
| 2423 | // dynamic linker, and should never be seen here. |
| 2424 | case elfcpp::R_386_COPY: |
| 2425 | case elfcpp::R_386_GLOB_DAT: |
| 2426 | case elfcpp::R_386_JUMP_SLOT: |
| 2427 | case elfcpp::R_386_RELATIVE: |
| 2428 | case elfcpp::R_386_TLS_TPOFF: |
| 2429 | case elfcpp::R_386_TLS_DTPMOD32: |
| 2430 | case elfcpp::R_386_TLS_DTPOFF32: |
| 2431 | case elfcpp::R_386_TLS_TPOFF32: |
| 2432 | case elfcpp::R_386_TLS_DESC: |
| 2433 | object->error(_("unexpected reloc %u in object file"), r_type); |
| 2434 | return 0; |
| 2435 | |
| 2436 | case elfcpp::R_386_32PLT: |
| 2437 | case elfcpp::R_386_TLS_GD_32: |
| 2438 | case elfcpp::R_386_TLS_GD_PUSH: |
| 2439 | case elfcpp::R_386_TLS_GD_CALL: |
| 2440 | case elfcpp::R_386_TLS_GD_POP: |
| 2441 | case elfcpp::R_386_TLS_LDM_32: |
| 2442 | case elfcpp::R_386_TLS_LDM_PUSH: |
| 2443 | case elfcpp::R_386_TLS_LDM_CALL: |
| 2444 | case elfcpp::R_386_TLS_LDM_POP: |
| 2445 | case elfcpp::R_386_USED_BY_INTEL_200: |
| 2446 | default: |
| 2447 | object->error(_("unsupported reloc %u in object file"), r_type); |
| 2448 | return 0; |
| 2449 | } |
| 2450 | } |
| 2451 | |
| 2452 | // Scan the relocs during a relocatable link. |
| 2453 | |
| 2454 | void |
| 2455 | Target_i386::scan_relocatable_relocs(const General_options& options, |
| 2456 | Symbol_table* symtab, |
| 2457 | Layout* layout, |
| 2458 | Sized_relobj<32, false>* object, |
| 2459 | unsigned int data_shndx, |
| 2460 | unsigned int sh_type, |
| 2461 | const unsigned char* prelocs, |
| 2462 | size_t reloc_count, |
| 2463 | Output_section* output_section, |
| 2464 | bool needs_special_offset_handling, |
| 2465 | size_t local_symbol_count, |
| 2466 | const unsigned char* plocal_symbols, |
| 2467 | Relocatable_relocs* rr) |
| 2468 | { |
| 2469 | gold_assert(sh_type == elfcpp::SHT_REL); |
| 2470 | |
| 2471 | typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_REL, |
| 2472 | Relocatable_size_for_reloc> Scan_relocatable_relocs; |
| 2473 | |
| 2474 | gold::scan_relocatable_relocs<32, false, elfcpp::SHT_REL, |
| 2475 | Scan_relocatable_relocs>( |
| 2476 | options, |
| 2477 | symtab, |
| 2478 | layout, |
| 2479 | object, |
| 2480 | data_shndx, |
| 2481 | prelocs, |
| 2482 | reloc_count, |
| 2483 | output_section, |
| 2484 | needs_special_offset_handling, |
| 2485 | local_symbol_count, |
| 2486 | plocal_symbols, |
| 2487 | rr); |
| 2488 | } |
| 2489 | |
| 2490 | // Relocate a section during a relocatable link. |
| 2491 | |
| 2492 | void |
| 2493 | Target_i386::relocate_for_relocatable( |
| 2494 | const Relocate_info<32, false>* relinfo, |
| 2495 | unsigned int sh_type, |
| 2496 | const unsigned char* prelocs, |
| 2497 | size_t reloc_count, |
| 2498 | Output_section* output_section, |
| 2499 | off_t offset_in_output_section, |
| 2500 | const Relocatable_relocs* rr, |
| 2501 | unsigned char* view, |
| 2502 | elfcpp::Elf_types<32>::Elf_Addr view_address, |
| 2503 | section_size_type view_size, |
| 2504 | unsigned char* reloc_view, |
| 2505 | section_size_type reloc_view_size) |
| 2506 | { |
| 2507 | gold_assert(sh_type == elfcpp::SHT_REL); |
| 2508 | |
| 2509 | gold::relocate_for_relocatable<32, false, elfcpp::SHT_REL>( |
| 2510 | relinfo, |
| 2511 | prelocs, |
| 2512 | reloc_count, |
| 2513 | output_section, |
| 2514 | offset_in_output_section, |
| 2515 | rr, |
| 2516 | view, |
| 2517 | view_address, |
| 2518 | view_size, |
| 2519 | reloc_view, |
| 2520 | reloc_view_size); |
| 2521 | } |
| 2522 | |
| 2523 | // Return the value to use for a dynamic which requires special |
| 2524 | // treatment. This is how we support equality comparisons of function |
| 2525 | // pointers across shared library boundaries, as described in the |
| 2526 | // processor specific ABI supplement. |
| 2527 | |
| 2528 | uint64_t |
| 2529 | Target_i386::do_dynsym_value(const Symbol* gsym) const |
| 2530 | { |
| 2531 | gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset()); |
| 2532 | return this->plt_section()->address() + gsym->plt_offset(); |
| 2533 | } |
| 2534 | |
| 2535 | // Return a string used to fill a code section with nops to take up |
| 2536 | // the specified length. |
| 2537 | |
| 2538 | std::string |
| 2539 | Target_i386::do_code_fill(section_size_type length) const |
| 2540 | { |
| 2541 | if (length >= 16) |
| 2542 | { |
| 2543 | // Build a jmp instruction to skip over the bytes. |
| 2544 | unsigned char jmp[5]; |
| 2545 | jmp[0] = 0xe9; |
| 2546 | elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5); |
| 2547 | return (std::string(reinterpret_cast<char*>(&jmp[0]), 5) |
| 2548 | + std::string(length - 5, '\0')); |
| 2549 | } |
| 2550 | |
| 2551 | // Nop sequences of various lengths. |
| 2552 | const char nop1[1] = { 0x90 }; // nop |
| 2553 | const char nop2[2] = { 0x66, 0x90 }; // xchg %ax %ax |
| 2554 | const char nop3[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi |
| 2555 | const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi |
| 2556 | const char nop5[5] = { 0x90, 0x8d, 0x74, 0x26, // nop |
| 2557 | 0x00 }; // leal 0(%esi,1),%esi |
| 2558 | const char nop6[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi |
| 2559 | 0x00, 0x00 }; |
| 2560 | const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi |
| 2561 | 0x00, 0x00, 0x00 }; |
| 2562 | const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop |
| 2563 | 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi |
| 2564 | const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi |
| 2565 | 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi |
| 2566 | 0x00 }; |
| 2567 | const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi |
| 2568 | 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi |
| 2569 | 0x00, 0x00 }; |
| 2570 | const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi |
| 2571 | 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi |
| 2572 | 0x00, 0x00, 0x00 }; |
| 2573 | const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi |
| 2574 | 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi |
| 2575 | 0x00, 0x00, 0x00, 0x00 }; |
| 2576 | const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi |
| 2577 | 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi |
| 2578 | 0x27, 0x00, 0x00, 0x00, |
| 2579 | 0x00 }; |
| 2580 | const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi |
| 2581 | 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi |
| 2582 | 0xbc, 0x27, 0x00, 0x00, |
| 2583 | 0x00, 0x00 }; |
| 2584 | const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15 |
| 2585 | 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,... |
| 2586 | 0x90, 0x90, 0x90, 0x90, |
| 2587 | 0x90, 0x90, 0x90 }; |
| 2588 | |
| 2589 | const char* nops[16] = { |
| 2590 | NULL, |
| 2591 | nop1, nop2, nop3, nop4, nop5, nop6, nop7, |
| 2592 | nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15 |
| 2593 | }; |
| 2594 | |
| 2595 | return std::string(nops[length], length); |
| 2596 | } |
| 2597 | |
| 2598 | // The selector for i386 object files. |
| 2599 | |
| 2600 | class Target_selector_i386 : public Target_selector |
| 2601 | { |
| 2602 | public: |
| 2603 | Target_selector_i386() |
| 2604 | : Target_selector(elfcpp::EM_386, 32, false, "elf32-i386") |
| 2605 | { } |
| 2606 | |
| 2607 | Target* |
| 2608 | do_instantiate_target() |
| 2609 | { return new Target_i386(); } |
| 2610 | }; |
| 2611 | |
| 2612 | Target_selector_i386 target_selector_i386; |
| 2613 | |
| 2614 | } // End anonymous namespace. |