| 1 | // i386.cc -- i386 target support for gold. |
| 2 | |
| 3 | // Copyright 2006, 2007, 2008, 2009 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 | #include "freebsd.h" |
| 41 | |
| 42 | namespace |
| 43 | { |
| 44 | |
| 45 | using namespace gold; |
| 46 | |
| 47 | class Output_data_plt_i386; |
| 48 | |
| 49 | // The i386 target class. |
| 50 | // TLS info comes from |
| 51 | // http://people.redhat.com/drepper/tls.pdf |
| 52 | // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt |
| 53 | |
| 54 | class Target_i386 : public Target_freebsd<32, false> |
| 55 | { |
| 56 | public: |
| 57 | typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section; |
| 58 | |
| 59 | Target_i386() |
| 60 | : Target_freebsd<32, false>(&i386_info), |
| 61 | got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL), |
| 62 | copy_relocs_(elfcpp::R_386_COPY), dynbss_(NULL), |
| 63 | got_mod_index_offset_(-1U), tls_base_symbol_defined_(false) |
| 64 | { } |
| 65 | |
| 66 | // Process the relocations to determine unreferenced sections for |
| 67 | // garbage collection. |
| 68 | void |
| 69 | gc_process_relocs(const General_options& options, |
| 70 | Symbol_table* symtab, |
| 71 | Layout* layout, |
| 72 | Sized_relobj<32, false>* object, |
| 73 | unsigned int data_shndx, |
| 74 | unsigned int sh_type, |
| 75 | const unsigned char* prelocs, |
| 76 | size_t reloc_count, |
| 77 | Output_section* output_section, |
| 78 | bool needs_special_offset_handling, |
| 79 | size_t local_symbol_count, |
| 80 | const unsigned char* plocal_symbols); |
| 81 | |
| 82 | // Scan the relocations to look for symbol adjustments. |
| 83 | void |
| 84 | scan_relocs(const General_options& options, |
| 85 | Symbol_table* symtab, |
| 86 | Layout* layout, |
| 87 | Sized_relobj<32, false>* object, |
| 88 | unsigned int data_shndx, |
| 89 | unsigned int sh_type, |
| 90 | const unsigned char* prelocs, |
| 91 | size_t reloc_count, |
| 92 | Output_section* output_section, |
| 93 | bool needs_special_offset_handling, |
| 94 | size_t local_symbol_count, |
| 95 | const unsigned char* plocal_symbols); |
| 96 | |
| 97 | // Finalize the sections. |
| 98 | void |
| 99 | do_finalize_sections(Layout*); |
| 100 | |
| 101 | // Return the value to use for a dynamic which requires special |
| 102 | // treatment. |
| 103 | uint64_t |
| 104 | do_dynsym_value(const Symbol*) const; |
| 105 | |
| 106 | // Relocate a section. |
| 107 | void |
| 108 | relocate_section(const Relocate_info<32, false>*, |
| 109 | unsigned int sh_type, |
| 110 | const unsigned char* prelocs, |
| 111 | size_t reloc_count, |
| 112 | Output_section* output_section, |
| 113 | bool needs_special_offset_handling, |
| 114 | unsigned char* view, |
| 115 | elfcpp::Elf_types<32>::Elf_Addr view_address, |
| 116 | section_size_type view_size); |
| 117 | |
| 118 | // Scan the relocs during a relocatable link. |
| 119 | void |
| 120 | scan_relocatable_relocs(const General_options& options, |
| 121 | Symbol_table* symtab, |
| 122 | Layout* layout, |
| 123 | Sized_relobj<32, false>* object, |
| 124 | unsigned int data_shndx, |
| 125 | unsigned int sh_type, |
| 126 | const unsigned char* prelocs, |
| 127 | size_t reloc_count, |
| 128 | Output_section* output_section, |
| 129 | bool needs_special_offset_handling, |
| 130 | size_t local_symbol_count, |
| 131 | const unsigned char* plocal_symbols, |
| 132 | Relocatable_relocs*); |
| 133 | |
| 134 | // Relocate a section during a relocatable link. |
| 135 | void |
| 136 | relocate_for_relocatable(const Relocate_info<32, false>*, |
| 137 | unsigned int sh_type, |
| 138 | const unsigned char* prelocs, |
| 139 | size_t reloc_count, |
| 140 | Output_section* output_section, |
| 141 | off_t offset_in_output_section, |
| 142 | const Relocatable_relocs*, |
| 143 | unsigned char* view, |
| 144 | elfcpp::Elf_types<32>::Elf_Addr view_address, |
| 145 | section_size_type view_size, |
| 146 | unsigned char* reloc_view, |
| 147 | section_size_type reloc_view_size); |
| 148 | |
| 149 | // Return a string used to fill a code section with nops. |
| 150 | std::string |
| 151 | do_code_fill(section_size_type length) const; |
| 152 | |
| 153 | // Return whether SYM is defined by the ABI. |
| 154 | bool |
| 155 | do_is_defined_by_abi(const Symbol* sym) const |
| 156 | { return strcmp(sym->name(), "___tls_get_addr") == 0; } |
| 157 | |
| 158 | // Return whether a symbol name implies a local label. The UnixWare |
| 159 | // 2.1 cc generates temporary symbols that start with .X, so we |
| 160 | // recognize them here. FIXME: do other SVR4 compilers also use .X?. |
| 161 | // If so, we should move the .X recognition into |
| 162 | // Target::do_is_local_label_name. |
| 163 | bool |
| 164 | do_is_local_label_name(const char* name) const |
| 165 | { |
| 166 | if (name[0] == '.' && name[1] == 'X') |
| 167 | return true; |
| 168 | return Target::do_is_local_label_name(name); |
| 169 | } |
| 170 | |
| 171 | // Return the size of the GOT section. |
| 172 | section_size_type |
| 173 | got_size() |
| 174 | { |
| 175 | gold_assert(this->got_ != NULL); |
| 176 | return this->got_->data_size(); |
| 177 | } |
| 178 | |
| 179 | private: |
| 180 | // The class which scans relocations. |
| 181 | struct Scan |
| 182 | { |
| 183 | inline void |
| 184 | local(const General_options& options, Symbol_table* symtab, |
| 185 | Layout* layout, Target_i386* target, |
| 186 | Sized_relobj<32, false>* object, |
| 187 | unsigned int data_shndx, |
| 188 | Output_section* output_section, |
| 189 | const elfcpp::Rel<32, false>& reloc, unsigned int r_type, |
| 190 | const elfcpp::Sym<32, false>& lsym); |
| 191 | |
| 192 | inline void |
| 193 | global(const General_options& options, Symbol_table* symtab, |
| 194 | Layout* layout, Target_i386* target, |
| 195 | Sized_relobj<32, false>* object, |
| 196 | unsigned int data_shndx, |
| 197 | Output_section* output_section, |
| 198 | const elfcpp::Rel<32, false>& reloc, unsigned int r_type, |
| 199 | Symbol* gsym); |
| 200 | |
| 201 | static void |
| 202 | unsupported_reloc_local(Sized_relobj<32, false>*, unsigned int r_type); |
| 203 | |
| 204 | static void |
| 205 | unsupported_reloc_global(Sized_relobj<32, false>*, unsigned int r_type, |
| 206 | Symbol*); |
| 207 | }; |
| 208 | |
| 209 | // The class which implements relocation. |
| 210 | class Relocate |
| 211 | { |
| 212 | public: |
| 213 | Relocate() |
| 214 | : skip_call_tls_get_addr_(false), |
| 215 | local_dynamic_type_(LOCAL_DYNAMIC_NONE) |
| 216 | { } |
| 217 | |
| 218 | ~Relocate() |
| 219 | { |
| 220 | if (this->skip_call_tls_get_addr_) |
| 221 | { |
| 222 | // FIXME: This needs to specify the location somehow. |
| 223 | gold_error(_("missing expected TLS relocation")); |
| 224 | } |
| 225 | } |
| 226 | |
| 227 | // Return whether the static relocation needs to be applied. |
| 228 | inline bool |
| 229 | should_apply_static_reloc(const Sized_symbol<32>* gsym, |
| 230 | int ref_flags, |
| 231 | bool is_32bit, |
| 232 | Output_section* output_section); |
| 233 | |
| 234 | // Do a relocation. Return false if the caller should not issue |
| 235 | // any warnings about this relocation. |
| 236 | inline bool |
| 237 | relocate(const Relocate_info<32, false>*, Target_i386*, Output_section*, |
| 238 | size_t relnum, const elfcpp::Rel<32, false>&, |
| 239 | unsigned int r_type, const Sized_symbol<32>*, |
| 240 | const Symbol_value<32>*, |
| 241 | unsigned char*, elfcpp::Elf_types<32>::Elf_Addr, |
| 242 | section_size_type); |
| 243 | |
| 244 | private: |
| 245 | // Do a TLS relocation. |
| 246 | inline void |
| 247 | relocate_tls(const Relocate_info<32, false>*, Target_i386* target, |
| 248 | size_t relnum, const elfcpp::Rel<32, false>&, |
| 249 | unsigned int r_type, const Sized_symbol<32>*, |
| 250 | const Symbol_value<32>*, |
| 251 | unsigned char*, elfcpp::Elf_types<32>::Elf_Addr, |
| 252 | section_size_type); |
| 253 | |
| 254 | // Do a TLS General-Dynamic to Initial-Exec transition. |
| 255 | inline void |
| 256 | tls_gd_to_ie(const Relocate_info<32, false>*, size_t relnum, |
| 257 | Output_segment* tls_segment, |
| 258 | const elfcpp::Rel<32, false>&, unsigned int r_type, |
| 259 | elfcpp::Elf_types<32>::Elf_Addr value, |
| 260 | unsigned char* view, |
| 261 | section_size_type view_size); |
| 262 | |
| 263 | // Do a TLS General-Dynamic to Local-Exec transition. |
| 264 | inline void |
| 265 | tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum, |
| 266 | Output_segment* tls_segment, |
| 267 | const elfcpp::Rel<32, false>&, unsigned int r_type, |
| 268 | elfcpp::Elf_types<32>::Elf_Addr value, |
| 269 | unsigned char* view, |
| 270 | section_size_type view_size); |
| 271 | |
| 272 | // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec |
| 273 | // transition. |
| 274 | inline void |
| 275 | tls_desc_gd_to_ie(const Relocate_info<32, false>*, size_t relnum, |
| 276 | Output_segment* tls_segment, |
| 277 | const elfcpp::Rel<32, false>&, unsigned int r_type, |
| 278 | elfcpp::Elf_types<32>::Elf_Addr value, |
| 279 | unsigned char* view, |
| 280 | section_size_type view_size); |
| 281 | |
| 282 | // Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec |
| 283 | // transition. |
| 284 | inline void |
| 285 | tls_desc_gd_to_le(const Relocate_info<32, false>*, size_t relnum, |
| 286 | Output_segment* tls_segment, |
| 287 | const elfcpp::Rel<32, false>&, unsigned int r_type, |
| 288 | elfcpp::Elf_types<32>::Elf_Addr value, |
| 289 | unsigned char* view, |
| 290 | section_size_type view_size); |
| 291 | |
| 292 | // Do a TLS Local-Dynamic to Local-Exec transition. |
| 293 | inline void |
| 294 | tls_ld_to_le(const Relocate_info<32, false>*, size_t relnum, |
| 295 | Output_segment* tls_segment, |
| 296 | const elfcpp::Rel<32, false>&, unsigned int r_type, |
| 297 | elfcpp::Elf_types<32>::Elf_Addr value, |
| 298 | unsigned char* view, |
| 299 | section_size_type view_size); |
| 300 | |
| 301 | // Do a TLS Initial-Exec to Local-Exec transition. |
| 302 | static inline void |
| 303 | tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum, |
| 304 | Output_segment* tls_segment, |
| 305 | const elfcpp::Rel<32, false>&, unsigned int r_type, |
| 306 | elfcpp::Elf_types<32>::Elf_Addr value, |
| 307 | unsigned char* view, |
| 308 | section_size_type view_size); |
| 309 | |
| 310 | // We need to keep track of which type of local dynamic relocation |
| 311 | // we have seen, so that we can optimize R_386_TLS_LDO_32 correctly. |
| 312 | enum Local_dynamic_type |
| 313 | { |
| 314 | LOCAL_DYNAMIC_NONE, |
| 315 | LOCAL_DYNAMIC_SUN, |
| 316 | LOCAL_DYNAMIC_GNU |
| 317 | }; |
| 318 | |
| 319 | // This is set if we should skip the next reloc, which should be a |
| 320 | // PLT32 reloc against ___tls_get_addr. |
| 321 | bool skip_call_tls_get_addr_; |
| 322 | // The type of local dynamic relocation we have seen in the section |
| 323 | // being relocated, if any. |
| 324 | Local_dynamic_type local_dynamic_type_; |
| 325 | }; |
| 326 | |
| 327 | // A class which returns the size required for a relocation type, |
| 328 | // used while scanning relocs during a relocatable link. |
| 329 | class Relocatable_size_for_reloc |
| 330 | { |
| 331 | public: |
| 332 | unsigned int |
| 333 | get_size_for_reloc(unsigned int, Relobj*); |
| 334 | }; |
| 335 | |
| 336 | // Adjust TLS relocation type based on the options and whether this |
| 337 | // is a local symbol. |
| 338 | static tls::Tls_optimization |
| 339 | optimize_tls_reloc(bool is_final, int r_type); |
| 340 | |
| 341 | // Get the GOT section, creating it if necessary. |
| 342 | Output_data_got<32, false>* |
| 343 | got_section(Symbol_table*, Layout*); |
| 344 | |
| 345 | // Get the GOT PLT section. |
| 346 | Output_data_space* |
| 347 | got_plt_section() const |
| 348 | { |
| 349 | gold_assert(this->got_plt_ != NULL); |
| 350 | return this->got_plt_; |
| 351 | } |
| 352 | |
| 353 | // Create a PLT entry for a global symbol. |
| 354 | void |
| 355 | make_plt_entry(Symbol_table*, Layout*, Symbol*); |
| 356 | |
| 357 | // Define the _TLS_MODULE_BASE_ symbol in the TLS segment. |
| 358 | void |
| 359 | define_tls_base_symbol(Symbol_table*, Layout*); |
| 360 | |
| 361 | // Create a GOT entry for the TLS module index. |
| 362 | unsigned int |
| 363 | got_mod_index_entry(Symbol_table* symtab, Layout* layout, |
| 364 | Sized_relobj<32, false>* object); |
| 365 | |
| 366 | // Get the PLT section. |
| 367 | const Output_data_plt_i386* |
| 368 | plt_section() const |
| 369 | { |
| 370 | gold_assert(this->plt_ != NULL); |
| 371 | return this->plt_; |
| 372 | } |
| 373 | |
| 374 | // Get the dynamic reloc section, creating it if necessary. |
| 375 | Reloc_section* |
| 376 | rel_dyn_section(Layout*); |
| 377 | |
| 378 | // Return true if the symbol may need a COPY relocation. |
| 379 | // References from an executable object to non-function symbols |
| 380 | // defined in a dynamic object may need a COPY relocation. |
| 381 | bool |
| 382 | may_need_copy_reloc(Symbol* gsym) |
| 383 | { |
| 384 | return (!parameters->options().shared() |
| 385 | && gsym->is_from_dynobj() |
| 386 | && gsym->type() != elfcpp::STT_FUNC); |
| 387 | } |
| 388 | |
| 389 | // Add a potential copy relocation. |
| 390 | void |
| 391 | copy_reloc(Symbol_table* symtab, Layout* layout, |
| 392 | Sized_relobj<32, false>* object, |
| 393 | unsigned int shndx, Output_section* output_section, |
| 394 | Symbol* sym, const elfcpp::Rel<32, false>& reloc) |
| 395 | { |
| 396 | this->copy_relocs_.copy_reloc(symtab, layout, |
| 397 | symtab->get_sized_symbol<32>(sym), |
| 398 | object, shndx, output_section, reloc, |
| 399 | this->rel_dyn_section(layout)); |
| 400 | } |
| 401 | |
| 402 | // Information about this specific target which we pass to the |
| 403 | // general Target structure. |
| 404 | static const Target::Target_info i386_info; |
| 405 | |
| 406 | // The types of GOT entries needed for this platform. |
| 407 | enum Got_type |
| 408 | { |
| 409 | GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol |
| 410 | GOT_TYPE_TLS_NOFFSET = 1, // GOT entry for negative TLS offset |
| 411 | GOT_TYPE_TLS_OFFSET = 2, // GOT entry for positive TLS offset |
| 412 | GOT_TYPE_TLS_PAIR = 3, // GOT entry for TLS module/offset pair |
| 413 | GOT_TYPE_TLS_DESC = 4 // GOT entry for TLS_DESC pair |
| 414 | }; |
| 415 | |
| 416 | // The GOT section. |
| 417 | Output_data_got<32, false>* got_; |
| 418 | // The PLT section. |
| 419 | Output_data_plt_i386* plt_; |
| 420 | // The GOT PLT section. |
| 421 | Output_data_space* got_plt_; |
| 422 | // The dynamic reloc section. |
| 423 | Reloc_section* rel_dyn_; |
| 424 | // Relocs saved to avoid a COPY reloc. |
| 425 | Copy_relocs<elfcpp::SHT_REL, 32, false> copy_relocs_; |
| 426 | // Space for variables copied with a COPY reloc. |
| 427 | Output_data_space* dynbss_; |
| 428 | // Offset of the GOT entry for the TLS module index. |
| 429 | unsigned int got_mod_index_offset_; |
| 430 | // True if the _TLS_MODULE_BASE_ symbol has been defined. |
| 431 | bool tls_base_symbol_defined_; |
| 432 | }; |
| 433 | |
| 434 | const Target::Target_info Target_i386::i386_info = |
| 435 | { |
| 436 | 32, // size |
| 437 | false, // is_big_endian |
| 438 | elfcpp::EM_386, // machine_code |
| 439 | false, // has_make_symbol |
| 440 | false, // has_resolve |
| 441 | true, // has_code_fill |
| 442 | true, // is_default_stack_executable |
| 443 | '\0', // wrap_char |
| 444 | "/usr/lib/libc.so.1", // dynamic_linker |
| 445 | 0x08048000, // default_text_segment_address |
| 446 | 0x1000, // abi_pagesize (overridable by -z max-page-size) |
| 447 | 0x1000, // common_pagesize (overridable by -z common-page-size) |
| 448 | elfcpp::SHN_UNDEF, // small_common_shndx |
| 449 | elfcpp::SHN_UNDEF, // large_common_shndx |
| 450 | 0, // small_common_section_flags |
| 451 | 0 // large_common_section_flags |
| 452 | }; |
| 453 | |
| 454 | // Get the GOT section, creating it if necessary. |
| 455 | |
| 456 | Output_data_got<32, false>* |
| 457 | Target_i386::got_section(Symbol_table* symtab, Layout* layout) |
| 458 | { |
| 459 | if (this->got_ == NULL) |
| 460 | { |
| 461 | gold_assert(symtab != NULL && layout != NULL); |
| 462 | |
| 463 | this->got_ = new Output_data_got<32, false>(); |
| 464 | |
| 465 | Output_section* os; |
| 466 | os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS, |
| 467 | (elfcpp::SHF_ALLOC |
| 468 | | elfcpp::SHF_WRITE), |
| 469 | this->got_); |
| 470 | os->set_is_relro(); |
| 471 | |
| 472 | // The old GNU linker creates a .got.plt section. We just |
| 473 | // create another set of data in the .got section. Note that we |
| 474 | // always create a PLT if we create a GOT, although the PLT |
| 475 | // might be empty. |
| 476 | this->got_plt_ = new Output_data_space(4, "** GOT PLT"); |
| 477 | os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS, |
| 478 | (elfcpp::SHF_ALLOC |
| 479 | | elfcpp::SHF_WRITE), |
| 480 | this->got_plt_); |
| 481 | os->set_is_relro(); |
| 482 | |
| 483 | // The first three entries are reserved. |
| 484 | this->got_plt_->set_current_data_size(3 * 4); |
| 485 | |
| 486 | // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT. |
| 487 | symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL, |
| 488 | this->got_plt_, |
| 489 | 0, 0, elfcpp::STT_OBJECT, |
| 490 | elfcpp::STB_LOCAL, |
| 491 | elfcpp::STV_HIDDEN, 0, |
| 492 | false, false); |
| 493 | } |
| 494 | |
| 495 | return this->got_; |
| 496 | } |
| 497 | |
| 498 | // Get the dynamic reloc section, creating it if necessary. |
| 499 | |
| 500 | Target_i386::Reloc_section* |
| 501 | Target_i386::rel_dyn_section(Layout* layout) |
| 502 | { |
| 503 | if (this->rel_dyn_ == NULL) |
| 504 | { |
| 505 | gold_assert(layout != NULL); |
| 506 | this->rel_dyn_ = new Reloc_section(parameters->options().combreloc()); |
| 507 | layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL, |
| 508 | elfcpp::SHF_ALLOC, this->rel_dyn_); |
| 509 | } |
| 510 | return this->rel_dyn_; |
| 511 | } |
| 512 | |
| 513 | // A class to handle the PLT data. |
| 514 | |
| 515 | class Output_data_plt_i386 : public Output_section_data |
| 516 | { |
| 517 | public: |
| 518 | typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section; |
| 519 | |
| 520 | Output_data_plt_i386(Layout*, Output_data_space*); |
| 521 | |
| 522 | // Add an entry to the PLT. |
| 523 | void |
| 524 | add_entry(Symbol* gsym); |
| 525 | |
| 526 | // Return the .rel.plt section data. |
| 527 | const Reloc_section* |
| 528 | rel_plt() const |
| 529 | { return this->rel_; } |
| 530 | |
| 531 | protected: |
| 532 | void |
| 533 | do_adjust_output_section(Output_section* os); |
| 534 | |
| 535 | // Write to a map file. |
| 536 | void |
| 537 | do_print_to_mapfile(Mapfile* mapfile) const |
| 538 | { mapfile->print_output_data(this, _("** PLT")); } |
| 539 | |
| 540 | private: |
| 541 | // The size of an entry in the PLT. |
| 542 | static const int plt_entry_size = 16; |
| 543 | |
| 544 | // The first entry in the PLT for an executable. |
| 545 | static unsigned char exec_first_plt_entry[plt_entry_size]; |
| 546 | |
| 547 | // The first entry in the PLT for a shared object. |
| 548 | static unsigned char dyn_first_plt_entry[plt_entry_size]; |
| 549 | |
| 550 | // Other entries in the PLT for an executable. |
| 551 | static unsigned char exec_plt_entry[plt_entry_size]; |
| 552 | |
| 553 | // Other entries in the PLT for a shared object. |
| 554 | static unsigned char dyn_plt_entry[plt_entry_size]; |
| 555 | |
| 556 | // Set the final size. |
| 557 | void |
| 558 | set_final_data_size() |
| 559 | { this->set_data_size((this->count_ + 1) * plt_entry_size); } |
| 560 | |
| 561 | // Write out the PLT data. |
| 562 | void |
| 563 | do_write(Output_file*); |
| 564 | |
| 565 | // The reloc section. |
| 566 | Reloc_section* rel_; |
| 567 | // The .got.plt section. |
| 568 | Output_data_space* got_plt_; |
| 569 | // The number of PLT entries. |
| 570 | unsigned int count_; |
| 571 | }; |
| 572 | |
| 573 | // Create the PLT section. The ordinary .got section is an argument, |
| 574 | // since we need to refer to the start. We also create our own .got |
| 575 | // section just for PLT entries. |
| 576 | |
| 577 | Output_data_plt_i386::Output_data_plt_i386(Layout* layout, |
| 578 | Output_data_space* got_plt) |
| 579 | : Output_section_data(4), got_plt_(got_plt), count_(0) |
| 580 | { |
| 581 | this->rel_ = new Reloc_section(false); |
| 582 | layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL, |
| 583 | elfcpp::SHF_ALLOC, this->rel_); |
| 584 | } |
| 585 | |
| 586 | void |
| 587 | Output_data_plt_i386::do_adjust_output_section(Output_section* os) |
| 588 | { |
| 589 | // UnixWare sets the entsize of .plt to 4, and so does the old GNU |
| 590 | // linker, and so do we. |
| 591 | os->set_entsize(4); |
| 592 | } |
| 593 | |
| 594 | // Add an entry to the PLT. |
| 595 | |
| 596 | void |
| 597 | Output_data_plt_i386::add_entry(Symbol* gsym) |
| 598 | { |
| 599 | gold_assert(!gsym->has_plt_offset()); |
| 600 | |
| 601 | // Note that when setting the PLT offset we skip the initial |
| 602 | // reserved PLT entry. |
| 603 | gsym->set_plt_offset((this->count_ + 1) * plt_entry_size); |
| 604 | |
| 605 | ++this->count_; |
| 606 | |
| 607 | section_offset_type got_offset = this->got_plt_->current_data_size(); |
| 608 | |
| 609 | // Every PLT entry needs a GOT entry which points back to the PLT |
| 610 | // entry (this will be changed by the dynamic linker, normally |
| 611 | // lazily when the function is called). |
| 612 | this->got_plt_->set_current_data_size(got_offset + 4); |
| 613 | |
| 614 | // Every PLT entry needs a reloc. |
| 615 | gsym->set_needs_dynsym_entry(); |
| 616 | this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_, |
| 617 | got_offset); |
| 618 | |
| 619 | // Note that we don't need to save the symbol. The contents of the |
| 620 | // PLT are independent of which symbols are used. The symbols only |
| 621 | // appear in the relocations. |
| 622 | } |
| 623 | |
| 624 | // The first entry in the PLT for an executable. |
| 625 | |
| 626 | unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] = |
| 627 | { |
| 628 | 0xff, 0x35, // pushl contents of memory address |
| 629 | 0, 0, 0, 0, // replaced with address of .got + 4 |
| 630 | 0xff, 0x25, // jmp indirect |
| 631 | 0, 0, 0, 0, // replaced with address of .got + 8 |
| 632 | 0, 0, 0, 0 // unused |
| 633 | }; |
| 634 | |
| 635 | // The first entry in the PLT for a shared object. |
| 636 | |
| 637 | unsigned char Output_data_plt_i386::dyn_first_plt_entry[plt_entry_size] = |
| 638 | { |
| 639 | 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx) |
| 640 | 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx) |
| 641 | 0, 0, 0, 0 // unused |
| 642 | }; |
| 643 | |
| 644 | // Subsequent entries in the PLT for an executable. |
| 645 | |
| 646 | unsigned char Output_data_plt_i386::exec_plt_entry[plt_entry_size] = |
| 647 | { |
| 648 | 0xff, 0x25, // jmp indirect |
| 649 | 0, 0, 0, 0, // replaced with address of symbol in .got |
| 650 | 0x68, // pushl immediate |
| 651 | 0, 0, 0, 0, // replaced with offset into relocation table |
| 652 | 0xe9, // jmp relative |
| 653 | 0, 0, 0, 0 // replaced with offset to start of .plt |
| 654 | }; |
| 655 | |
| 656 | // Subsequent entries in the PLT for a shared object. |
| 657 | |
| 658 | unsigned char Output_data_plt_i386::dyn_plt_entry[plt_entry_size] = |
| 659 | { |
| 660 | 0xff, 0xa3, // jmp *offset(%ebx) |
| 661 | 0, 0, 0, 0, // replaced with offset of symbol in .got |
| 662 | 0x68, // pushl immediate |
| 663 | 0, 0, 0, 0, // replaced with offset into relocation table |
| 664 | 0xe9, // jmp relative |
| 665 | 0, 0, 0, 0 // replaced with offset to start of .plt |
| 666 | }; |
| 667 | |
| 668 | // Write out the PLT. This uses the hand-coded instructions above, |
| 669 | // and adjusts them as needed. This is all specified by the i386 ELF |
| 670 | // Processor Supplement. |
| 671 | |
| 672 | void |
| 673 | Output_data_plt_i386::do_write(Output_file* of) |
| 674 | { |
| 675 | const off_t offset = this->offset(); |
| 676 | const section_size_type oview_size = |
| 677 | convert_to_section_size_type(this->data_size()); |
| 678 | unsigned char* const oview = of->get_output_view(offset, oview_size); |
| 679 | |
| 680 | const off_t got_file_offset = this->got_plt_->offset(); |
| 681 | const section_size_type got_size = |
| 682 | convert_to_section_size_type(this->got_plt_->data_size()); |
| 683 | unsigned char* const got_view = of->get_output_view(got_file_offset, |
| 684 | got_size); |
| 685 | |
| 686 | unsigned char* pov = oview; |
| 687 | |
| 688 | elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address(); |
| 689 | elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address(); |
| 690 | |
| 691 | if (parameters->options().shared()) |
| 692 | memcpy(pov, dyn_first_plt_entry, plt_entry_size); |
| 693 | else |
| 694 | { |
| 695 | memcpy(pov, exec_first_plt_entry, plt_entry_size); |
| 696 | elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4); |
| 697 | elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8); |
| 698 | } |
| 699 | pov += plt_entry_size; |
| 700 | |
| 701 | unsigned char* got_pov = got_view; |
| 702 | |
| 703 | memset(got_pov, 0, 12); |
| 704 | got_pov += 12; |
| 705 | |
| 706 | const int rel_size = elfcpp::Elf_sizes<32>::rel_size; |
| 707 | |
| 708 | unsigned int plt_offset = plt_entry_size; |
| 709 | unsigned int plt_rel_offset = 0; |
| 710 | unsigned int got_offset = 12; |
| 711 | const unsigned int count = this->count_; |
| 712 | for (unsigned int i = 0; |
| 713 | i < count; |
| 714 | ++i, |
| 715 | pov += plt_entry_size, |
| 716 | got_pov += 4, |
| 717 | plt_offset += plt_entry_size, |
| 718 | plt_rel_offset += rel_size, |
| 719 | got_offset += 4) |
| 720 | { |
| 721 | // Set and adjust the PLT entry itself. |
| 722 | |
| 723 | if (parameters->options().shared()) |
| 724 | { |
| 725 | memcpy(pov, dyn_plt_entry, plt_entry_size); |
| 726 | elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset); |
| 727 | } |
| 728 | else |
| 729 | { |
| 730 | memcpy(pov, exec_plt_entry, plt_entry_size); |
| 731 | elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, |
| 732 | (got_address |
| 733 | + got_offset)); |
| 734 | } |
| 735 | |
| 736 | elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset); |
| 737 | elfcpp::Swap<32, false>::writeval(pov + 12, |
| 738 | - (plt_offset + plt_entry_size)); |
| 739 | |
| 740 | // Set the entry in the GOT. |
| 741 | elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6); |
| 742 | } |
| 743 | |
| 744 | gold_assert(static_cast<section_size_type>(pov - oview) == oview_size); |
| 745 | gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size); |
| 746 | |
| 747 | of->write_output_view(offset, oview_size, oview); |
| 748 | of->write_output_view(got_file_offset, got_size, got_view); |
| 749 | } |
| 750 | |
| 751 | // Create a PLT entry for a global symbol. |
| 752 | |
| 753 | void |
| 754 | Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym) |
| 755 | { |
| 756 | if (gsym->has_plt_offset()) |
| 757 | return; |
| 758 | |
| 759 | if (this->plt_ == NULL) |
| 760 | { |
| 761 | // Create the GOT sections first. |
| 762 | this->got_section(symtab, layout); |
| 763 | |
| 764 | this->plt_ = new Output_data_plt_i386(layout, this->got_plt_); |
| 765 | layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS, |
| 766 | (elfcpp::SHF_ALLOC |
| 767 | | elfcpp::SHF_EXECINSTR), |
| 768 | this->plt_); |
| 769 | } |
| 770 | |
| 771 | this->plt_->add_entry(gsym); |
| 772 | } |
| 773 | |
| 774 | // Define the _TLS_MODULE_BASE_ symbol in the TLS segment. |
| 775 | |
| 776 | void |
| 777 | Target_i386::define_tls_base_symbol(Symbol_table* symtab, Layout* layout) |
| 778 | { |
| 779 | if (this->tls_base_symbol_defined_) |
| 780 | return; |
| 781 | |
| 782 | Output_segment* tls_segment = layout->tls_segment(); |
| 783 | if (tls_segment != NULL) |
| 784 | { |
| 785 | bool is_exec = parameters->options().output_is_executable(); |
| 786 | symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL, |
| 787 | tls_segment, 0, 0, |
| 788 | elfcpp::STT_TLS, |
| 789 | elfcpp::STB_LOCAL, |
| 790 | elfcpp::STV_HIDDEN, 0, |
| 791 | (is_exec |
| 792 | ? Symbol::SEGMENT_END |
| 793 | : Symbol::SEGMENT_START), |
| 794 | true); |
| 795 | } |
| 796 | this->tls_base_symbol_defined_ = true; |
| 797 | } |
| 798 | |
| 799 | // Create a GOT entry for the TLS module index. |
| 800 | |
| 801 | unsigned int |
| 802 | Target_i386::got_mod_index_entry(Symbol_table* symtab, Layout* layout, |
| 803 | Sized_relobj<32, false>* object) |
| 804 | { |
| 805 | if (this->got_mod_index_offset_ == -1U) |
| 806 | { |
| 807 | gold_assert(symtab != NULL && layout != NULL && object != NULL); |
| 808 | Reloc_section* rel_dyn = this->rel_dyn_section(layout); |
| 809 | Output_data_got<32, false>* got = this->got_section(symtab, layout); |
| 810 | unsigned int got_offset = got->add_constant(0); |
| 811 | rel_dyn->add_local(object, 0, elfcpp::R_386_TLS_DTPMOD32, got, |
| 812 | got_offset); |
| 813 | got->add_constant(0); |
| 814 | this->got_mod_index_offset_ = got_offset; |
| 815 | } |
| 816 | return this->got_mod_index_offset_; |
| 817 | } |
| 818 | |
| 819 | // Optimize the TLS relocation type based on what we know about the |
| 820 | // symbol. IS_FINAL is true if the final address of this symbol is |
| 821 | // known at link time. |
| 822 | |
| 823 | tls::Tls_optimization |
| 824 | Target_i386::optimize_tls_reloc(bool is_final, int r_type) |
| 825 | { |
| 826 | // If we are generating a shared library, then we can't do anything |
| 827 | // in the linker. |
| 828 | if (parameters->options().shared()) |
| 829 | return tls::TLSOPT_NONE; |
| 830 | |
| 831 | switch (r_type) |
| 832 | { |
| 833 | case elfcpp::R_386_TLS_GD: |
| 834 | case elfcpp::R_386_TLS_GOTDESC: |
| 835 | case elfcpp::R_386_TLS_DESC_CALL: |
| 836 | // These are General-Dynamic which permits fully general TLS |
| 837 | // access. Since we know that we are generating an executable, |
| 838 | // we can convert this to Initial-Exec. If we also know that |
| 839 | // this is a local symbol, we can further switch to Local-Exec. |
| 840 | if (is_final) |
| 841 | return tls::TLSOPT_TO_LE; |
| 842 | return tls::TLSOPT_TO_IE; |
| 843 | |
| 844 | case elfcpp::R_386_TLS_LDM: |
| 845 | // This is Local-Dynamic, which refers to a local symbol in the |
| 846 | // dynamic TLS block. Since we know that we generating an |
| 847 | // executable, we can switch to Local-Exec. |
| 848 | return tls::TLSOPT_TO_LE; |
| 849 | |
| 850 | case elfcpp::R_386_TLS_LDO_32: |
| 851 | // Another type of Local-Dynamic relocation. |
| 852 | return tls::TLSOPT_TO_LE; |
| 853 | |
| 854 | case elfcpp::R_386_TLS_IE: |
| 855 | case elfcpp::R_386_TLS_GOTIE: |
| 856 | case elfcpp::R_386_TLS_IE_32: |
| 857 | // These are Initial-Exec relocs which get the thread offset |
| 858 | // from the GOT. If we know that we are linking against the |
| 859 | // local symbol, we can switch to Local-Exec, which links the |
| 860 | // thread offset into the instruction. |
| 861 | if (is_final) |
| 862 | return tls::TLSOPT_TO_LE; |
| 863 | return tls::TLSOPT_NONE; |
| 864 | |
| 865 | case elfcpp::R_386_TLS_LE: |
| 866 | case elfcpp::R_386_TLS_LE_32: |
| 867 | // When we already have Local-Exec, there is nothing further we |
| 868 | // can do. |
| 869 | return tls::TLSOPT_NONE; |
| 870 | |
| 871 | default: |
| 872 | gold_unreachable(); |
| 873 | } |
| 874 | } |
| 875 | |
| 876 | // Report an unsupported relocation against a local symbol. |
| 877 | |
| 878 | void |
| 879 | Target_i386::Scan::unsupported_reloc_local(Sized_relobj<32, false>* object, |
| 880 | unsigned int r_type) |
| 881 | { |
| 882 | gold_error(_("%s: unsupported reloc %u against local symbol"), |
| 883 | object->name().c_str(), r_type); |
| 884 | } |
| 885 | |
| 886 | // Scan a relocation for a local symbol. |
| 887 | |
| 888 | inline void |
| 889 | Target_i386::Scan::local(const General_options&, |
| 890 | Symbol_table* symtab, |
| 891 | Layout* layout, |
| 892 | Target_i386* target, |
| 893 | Sized_relobj<32, false>* object, |
| 894 | unsigned int data_shndx, |
| 895 | Output_section* output_section, |
| 896 | const elfcpp::Rel<32, false>& reloc, |
| 897 | unsigned int r_type, |
| 898 | const elfcpp::Sym<32, false>& lsym) |
| 899 | { |
| 900 | switch (r_type) |
| 901 | { |
| 902 | case elfcpp::R_386_NONE: |
| 903 | case elfcpp::R_386_GNU_VTINHERIT: |
| 904 | case elfcpp::R_386_GNU_VTENTRY: |
| 905 | break; |
| 906 | |
| 907 | case elfcpp::R_386_32: |
| 908 | // If building a shared library (or a position-independent |
| 909 | // executable), we need to create a dynamic relocation for |
| 910 | // this location. The relocation applied at link time will |
| 911 | // apply the link-time value, so we flag the location with |
| 912 | // an R_386_RELATIVE relocation so the dynamic loader can |
| 913 | // relocate it easily. |
| 914 | if (parameters->options().output_is_position_independent()) |
| 915 | { |
| 916 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
| 917 | unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); |
| 918 | rel_dyn->add_local_relative(object, r_sym, elfcpp::R_386_RELATIVE, |
| 919 | output_section, data_shndx, |
| 920 | reloc.get_r_offset()); |
| 921 | } |
| 922 | break; |
| 923 | |
| 924 | case elfcpp::R_386_16: |
| 925 | case elfcpp::R_386_8: |
| 926 | // If building a shared library (or a position-independent |
| 927 | // executable), we need to create a dynamic relocation for |
| 928 | // this location. Because the addend needs to remain in the |
| 929 | // data section, we need to be careful not to apply this |
| 930 | // relocation statically. |
| 931 | if (parameters->options().output_is_position_independent()) |
| 932 | { |
| 933 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
| 934 | unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); |
| 935 | if (lsym.get_st_type() != elfcpp::STT_SECTION) |
| 936 | rel_dyn->add_local(object, r_sym, r_type, output_section, |
| 937 | data_shndx, reloc.get_r_offset()); |
| 938 | else |
| 939 | { |
| 940 | gold_assert(lsym.get_st_value() == 0); |
| 941 | unsigned int shndx = lsym.get_st_shndx(); |
| 942 | bool is_ordinary; |
| 943 | shndx = object->adjust_sym_shndx(r_sym, shndx, |
| 944 | &is_ordinary); |
| 945 | if (!is_ordinary) |
| 946 | object->error(_("section symbol %u has bad shndx %u"), |
| 947 | r_sym, shndx); |
| 948 | else |
| 949 | rel_dyn->add_local_section(object, shndx, |
| 950 | r_type, output_section, |
| 951 | data_shndx, reloc.get_r_offset()); |
| 952 | } |
| 953 | } |
| 954 | break; |
| 955 | |
| 956 | case elfcpp::R_386_PC32: |
| 957 | case elfcpp::R_386_PC16: |
| 958 | case elfcpp::R_386_PC8: |
| 959 | break; |
| 960 | |
| 961 | case elfcpp::R_386_PLT32: |
| 962 | // Since we know this is a local symbol, we can handle this as a |
| 963 | // PC32 reloc. |
| 964 | break; |
| 965 | |
| 966 | case elfcpp::R_386_GOTOFF: |
| 967 | case elfcpp::R_386_GOTPC: |
| 968 | // We need a GOT section. |
| 969 | target->got_section(symtab, layout); |
| 970 | break; |
| 971 | |
| 972 | case elfcpp::R_386_GOT32: |
| 973 | { |
| 974 | // The symbol requires a GOT entry. |
| 975 | Output_data_got<32, false>* got = target->got_section(symtab, layout); |
| 976 | unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); |
| 977 | if (got->add_local(object, r_sym, GOT_TYPE_STANDARD)) |
| 978 | { |
| 979 | // If we are generating a shared object, we need to add a |
| 980 | // dynamic RELATIVE relocation for this symbol's GOT entry. |
| 981 | if (parameters->options().output_is_position_independent()) |
| 982 | { |
| 983 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
| 984 | unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); |
| 985 | rel_dyn->add_local_relative( |
| 986 | object, r_sym, elfcpp::R_386_RELATIVE, got, |
| 987 | object->local_got_offset(r_sym, GOT_TYPE_STANDARD)); |
| 988 | } |
| 989 | } |
| 990 | } |
| 991 | break; |
| 992 | |
| 993 | // These are relocations which should only be seen by the |
| 994 | // dynamic linker, and should never be seen here. |
| 995 | case elfcpp::R_386_COPY: |
| 996 | case elfcpp::R_386_GLOB_DAT: |
| 997 | case elfcpp::R_386_JUMP_SLOT: |
| 998 | case elfcpp::R_386_RELATIVE: |
| 999 | case elfcpp::R_386_TLS_TPOFF: |
| 1000 | case elfcpp::R_386_TLS_DTPMOD32: |
| 1001 | case elfcpp::R_386_TLS_DTPOFF32: |
| 1002 | case elfcpp::R_386_TLS_TPOFF32: |
| 1003 | case elfcpp::R_386_TLS_DESC: |
| 1004 | gold_error(_("%s: unexpected reloc %u in object file"), |
| 1005 | object->name().c_str(), r_type); |
| 1006 | break; |
| 1007 | |
| 1008 | // These are initial TLS relocs, which are expected when |
| 1009 | // linking. |
| 1010 | case elfcpp::R_386_TLS_GD: // Global-dynamic |
| 1011 | case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url) |
| 1012 | case elfcpp::R_386_TLS_DESC_CALL: |
| 1013 | case elfcpp::R_386_TLS_LDM: // Local-dynamic |
| 1014 | case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic |
| 1015 | case elfcpp::R_386_TLS_IE: // Initial-exec |
| 1016 | case elfcpp::R_386_TLS_IE_32: |
| 1017 | case elfcpp::R_386_TLS_GOTIE: |
| 1018 | case elfcpp::R_386_TLS_LE: // Local-exec |
| 1019 | case elfcpp::R_386_TLS_LE_32: |
| 1020 | { |
| 1021 | bool output_is_shared = parameters->options().shared(); |
| 1022 | const tls::Tls_optimization optimized_type |
| 1023 | = Target_i386::optimize_tls_reloc(!output_is_shared, r_type); |
| 1024 | switch (r_type) |
| 1025 | { |
| 1026 | case elfcpp::R_386_TLS_GD: // Global-dynamic |
| 1027 | if (optimized_type == tls::TLSOPT_NONE) |
| 1028 | { |
| 1029 | // Create a pair of GOT entries for the module index and |
| 1030 | // dtv-relative offset. |
| 1031 | Output_data_got<32, false>* got |
| 1032 | = target->got_section(symtab, layout); |
| 1033 | unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); |
| 1034 | unsigned int shndx = lsym.get_st_shndx(); |
| 1035 | bool is_ordinary; |
| 1036 | shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary); |
| 1037 | if (!is_ordinary) |
| 1038 | object->error(_("local symbol %u has bad shndx %u"), |
| 1039 | r_sym, shndx); |
| 1040 | else |
| 1041 | got->add_local_pair_with_rel(object, r_sym, shndx, |
| 1042 | GOT_TYPE_TLS_PAIR, |
| 1043 | target->rel_dyn_section(layout), |
| 1044 | elfcpp::R_386_TLS_DTPMOD32, 0); |
| 1045 | } |
| 1046 | else if (optimized_type != tls::TLSOPT_TO_LE) |
| 1047 | unsupported_reloc_local(object, r_type); |
| 1048 | break; |
| 1049 | |
| 1050 | case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva) |
| 1051 | target->define_tls_base_symbol(symtab, layout); |
| 1052 | if (optimized_type == tls::TLSOPT_NONE) |
| 1053 | { |
| 1054 | // Create a double GOT entry with an R_386_TLS_DESC reloc. |
| 1055 | Output_data_got<32, false>* got |
| 1056 | = target->got_section(symtab, layout); |
| 1057 | unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); |
| 1058 | unsigned int shndx = lsym.get_st_shndx(); |
| 1059 | bool is_ordinary; |
| 1060 | shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary); |
| 1061 | if (!is_ordinary) |
| 1062 | object->error(_("local symbol %u has bad shndx %u"), |
| 1063 | r_sym, shndx); |
| 1064 | else |
| 1065 | got->add_local_pair_with_rel(object, r_sym, shndx, |
| 1066 | GOT_TYPE_TLS_DESC, |
| 1067 | target->rel_dyn_section(layout), |
| 1068 | elfcpp::R_386_TLS_DESC, 0); |
| 1069 | } |
| 1070 | else if (optimized_type != tls::TLSOPT_TO_LE) |
| 1071 | unsupported_reloc_local(object, r_type); |
| 1072 | break; |
| 1073 | |
| 1074 | case elfcpp::R_386_TLS_DESC_CALL: |
| 1075 | break; |
| 1076 | |
| 1077 | case elfcpp::R_386_TLS_LDM: // Local-dynamic |
| 1078 | if (optimized_type == tls::TLSOPT_NONE) |
| 1079 | { |
| 1080 | // Create a GOT entry for the module index. |
| 1081 | target->got_mod_index_entry(symtab, layout, object); |
| 1082 | } |
| 1083 | else if (optimized_type != tls::TLSOPT_TO_LE) |
| 1084 | unsupported_reloc_local(object, r_type); |
| 1085 | break; |
| 1086 | |
| 1087 | case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic |
| 1088 | break; |
| 1089 | |
| 1090 | case elfcpp::R_386_TLS_IE: // Initial-exec |
| 1091 | case elfcpp::R_386_TLS_IE_32: |
| 1092 | case elfcpp::R_386_TLS_GOTIE: |
| 1093 | layout->set_has_static_tls(); |
| 1094 | if (optimized_type == tls::TLSOPT_NONE) |
| 1095 | { |
| 1096 | // For the R_386_TLS_IE relocation, we need to create a |
| 1097 | // dynamic relocation when building a shared library. |
| 1098 | if (r_type == elfcpp::R_386_TLS_IE |
| 1099 | && parameters->options().shared()) |
| 1100 | { |
| 1101 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
| 1102 | unsigned int r_sym |
| 1103 | = elfcpp::elf_r_sym<32>(reloc.get_r_info()); |
| 1104 | rel_dyn->add_local_relative(object, r_sym, |
| 1105 | elfcpp::R_386_RELATIVE, |
| 1106 | output_section, data_shndx, |
| 1107 | reloc.get_r_offset()); |
| 1108 | } |
| 1109 | // Create a GOT entry for the tp-relative offset. |
| 1110 | Output_data_got<32, false>* got |
| 1111 | = target->got_section(symtab, layout); |
| 1112 | unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); |
| 1113 | unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32 |
| 1114 | ? elfcpp::R_386_TLS_TPOFF32 |
| 1115 | : elfcpp::R_386_TLS_TPOFF); |
| 1116 | unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32 |
| 1117 | ? GOT_TYPE_TLS_OFFSET |
| 1118 | : GOT_TYPE_TLS_NOFFSET); |
| 1119 | got->add_local_with_rel(object, r_sym, got_type, |
| 1120 | target->rel_dyn_section(layout), |
| 1121 | dyn_r_type); |
| 1122 | } |
| 1123 | else if (optimized_type != tls::TLSOPT_TO_LE) |
| 1124 | unsupported_reloc_local(object, r_type); |
| 1125 | break; |
| 1126 | |
| 1127 | case elfcpp::R_386_TLS_LE: // Local-exec |
| 1128 | case elfcpp::R_386_TLS_LE_32: |
| 1129 | layout->set_has_static_tls(); |
| 1130 | if (output_is_shared) |
| 1131 | { |
| 1132 | // We need to create a dynamic relocation. |
| 1133 | gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION); |
| 1134 | unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); |
| 1135 | unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32 |
| 1136 | ? elfcpp::R_386_TLS_TPOFF32 |
| 1137 | : elfcpp::R_386_TLS_TPOFF); |
| 1138 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
| 1139 | rel_dyn->add_local(object, r_sym, dyn_r_type, output_section, |
| 1140 | data_shndx, reloc.get_r_offset()); |
| 1141 | } |
| 1142 | break; |
| 1143 | |
| 1144 | default: |
| 1145 | gold_unreachable(); |
| 1146 | } |
| 1147 | } |
| 1148 | break; |
| 1149 | |
| 1150 | case elfcpp::R_386_32PLT: |
| 1151 | case elfcpp::R_386_TLS_GD_32: |
| 1152 | case elfcpp::R_386_TLS_GD_PUSH: |
| 1153 | case elfcpp::R_386_TLS_GD_CALL: |
| 1154 | case elfcpp::R_386_TLS_GD_POP: |
| 1155 | case elfcpp::R_386_TLS_LDM_32: |
| 1156 | case elfcpp::R_386_TLS_LDM_PUSH: |
| 1157 | case elfcpp::R_386_TLS_LDM_CALL: |
| 1158 | case elfcpp::R_386_TLS_LDM_POP: |
| 1159 | case elfcpp::R_386_USED_BY_INTEL_200: |
| 1160 | default: |
| 1161 | unsupported_reloc_local(object, r_type); |
| 1162 | break; |
| 1163 | } |
| 1164 | } |
| 1165 | |
| 1166 | // Report an unsupported relocation against a global symbol. |
| 1167 | |
| 1168 | void |
| 1169 | Target_i386::Scan::unsupported_reloc_global(Sized_relobj<32, false>* object, |
| 1170 | unsigned int r_type, |
| 1171 | Symbol* gsym) |
| 1172 | { |
| 1173 | gold_error(_("%s: unsupported reloc %u against global symbol %s"), |
| 1174 | object->name().c_str(), r_type, gsym->demangled_name().c_str()); |
| 1175 | } |
| 1176 | |
| 1177 | // Scan a relocation for a global symbol. |
| 1178 | |
| 1179 | inline void |
| 1180 | Target_i386::Scan::global(const General_options&, |
| 1181 | Symbol_table* symtab, |
| 1182 | Layout* layout, |
| 1183 | Target_i386* target, |
| 1184 | Sized_relobj<32, false>* object, |
| 1185 | unsigned int data_shndx, |
| 1186 | Output_section* output_section, |
| 1187 | const elfcpp::Rel<32, false>& reloc, |
| 1188 | unsigned int r_type, |
| 1189 | Symbol* gsym) |
| 1190 | { |
| 1191 | switch (r_type) |
| 1192 | { |
| 1193 | case elfcpp::R_386_NONE: |
| 1194 | case elfcpp::R_386_GNU_VTINHERIT: |
| 1195 | case elfcpp::R_386_GNU_VTENTRY: |
| 1196 | break; |
| 1197 | |
| 1198 | case elfcpp::R_386_32: |
| 1199 | case elfcpp::R_386_16: |
| 1200 | case elfcpp::R_386_8: |
| 1201 | { |
| 1202 | // Make a PLT entry if necessary. |
| 1203 | if (gsym->needs_plt_entry()) |
| 1204 | { |
| 1205 | target->make_plt_entry(symtab, layout, gsym); |
| 1206 | // Since this is not a PC-relative relocation, we may be |
| 1207 | // taking the address of a function. In that case we need to |
| 1208 | // set the entry in the dynamic symbol table to the address of |
| 1209 | // the PLT entry. |
| 1210 | if (gsym->is_from_dynobj() && !parameters->options().shared()) |
| 1211 | gsym->set_needs_dynsym_value(); |
| 1212 | } |
| 1213 | // Make a dynamic relocation if necessary. |
| 1214 | if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF)) |
| 1215 | { |
| 1216 | if (target->may_need_copy_reloc(gsym)) |
| 1217 | { |
| 1218 | target->copy_reloc(symtab, layout, object, |
| 1219 | data_shndx, output_section, gsym, reloc); |
| 1220 | } |
| 1221 | else if (r_type == elfcpp::R_386_32 |
| 1222 | && gsym->can_use_relative_reloc(false)) |
| 1223 | { |
| 1224 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
| 1225 | rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE, |
| 1226 | output_section, object, |
| 1227 | data_shndx, reloc.get_r_offset()); |
| 1228 | } |
| 1229 | else |
| 1230 | { |
| 1231 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
| 1232 | rel_dyn->add_global(gsym, r_type, output_section, object, |
| 1233 | data_shndx, reloc.get_r_offset()); |
| 1234 | } |
| 1235 | } |
| 1236 | } |
| 1237 | break; |
| 1238 | |
| 1239 | case elfcpp::R_386_PC32: |
| 1240 | case elfcpp::R_386_PC16: |
| 1241 | case elfcpp::R_386_PC8: |
| 1242 | { |
| 1243 | // Make a PLT entry if necessary. |
| 1244 | if (gsym->needs_plt_entry()) |
| 1245 | { |
| 1246 | // These relocations are used for function calls only in |
| 1247 | // non-PIC code. For a 32-bit relocation in a shared library, |
| 1248 | // we'll need a text relocation anyway, so we can skip the |
| 1249 | // PLT entry and let the dynamic linker bind the call directly |
| 1250 | // to the target. For smaller relocations, we should use a |
| 1251 | // PLT entry to ensure that the call can reach. |
| 1252 | if (!parameters->options().shared() |
| 1253 | || r_type != elfcpp::R_386_PC32) |
| 1254 | target->make_plt_entry(symtab, layout, gsym); |
| 1255 | } |
| 1256 | // Make a dynamic relocation if necessary. |
| 1257 | int flags = Symbol::NON_PIC_REF; |
| 1258 | if (gsym->type() == elfcpp::STT_FUNC) |
| 1259 | flags |= Symbol::FUNCTION_CALL; |
| 1260 | if (gsym->needs_dynamic_reloc(flags)) |
| 1261 | { |
| 1262 | if (target->may_need_copy_reloc(gsym)) |
| 1263 | { |
| 1264 | target->copy_reloc(symtab, layout, object, |
| 1265 | data_shndx, output_section, gsym, reloc); |
| 1266 | } |
| 1267 | else |
| 1268 | { |
| 1269 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
| 1270 | rel_dyn->add_global(gsym, r_type, output_section, object, |
| 1271 | data_shndx, reloc.get_r_offset()); |
| 1272 | } |
| 1273 | } |
| 1274 | } |
| 1275 | break; |
| 1276 | |
| 1277 | case elfcpp::R_386_GOT32: |
| 1278 | { |
| 1279 | // The symbol requires a GOT entry. |
| 1280 | Output_data_got<32, false>* got = target->got_section(symtab, layout); |
| 1281 | if (gsym->final_value_is_known()) |
| 1282 | got->add_global(gsym, GOT_TYPE_STANDARD); |
| 1283 | else |
| 1284 | { |
| 1285 | // If this symbol is not fully resolved, we need to add a |
| 1286 | // GOT entry with a dynamic relocation. |
| 1287 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
| 1288 | if (gsym->is_from_dynobj() |
| 1289 | || gsym->is_undefined() |
| 1290 | || gsym->is_preemptible()) |
| 1291 | got->add_global_with_rel(gsym, GOT_TYPE_STANDARD, |
| 1292 | rel_dyn, elfcpp::R_386_GLOB_DAT); |
| 1293 | else |
| 1294 | { |
| 1295 | if (got->add_global(gsym, GOT_TYPE_STANDARD)) |
| 1296 | rel_dyn->add_global_relative( |
| 1297 | gsym, elfcpp::R_386_RELATIVE, got, |
| 1298 | gsym->got_offset(GOT_TYPE_STANDARD)); |
| 1299 | } |
| 1300 | } |
| 1301 | } |
| 1302 | break; |
| 1303 | |
| 1304 | case elfcpp::R_386_PLT32: |
| 1305 | // If the symbol is fully resolved, this is just a PC32 reloc. |
| 1306 | // Otherwise we need a PLT entry. |
| 1307 | if (gsym->final_value_is_known()) |
| 1308 | break; |
| 1309 | // If building a shared library, we can also skip the PLT entry |
| 1310 | // if the symbol is defined in the output file and is protected |
| 1311 | // or hidden. |
| 1312 | if (gsym->is_defined() |
| 1313 | && !gsym->is_from_dynobj() |
| 1314 | && !gsym->is_preemptible()) |
| 1315 | break; |
| 1316 | target->make_plt_entry(symtab, layout, gsym); |
| 1317 | break; |
| 1318 | |
| 1319 | case elfcpp::R_386_GOTOFF: |
| 1320 | case elfcpp::R_386_GOTPC: |
| 1321 | // We need a GOT section. |
| 1322 | target->got_section(symtab, layout); |
| 1323 | break; |
| 1324 | |
| 1325 | // These are relocations which should only be seen by the |
| 1326 | // dynamic linker, and should never be seen here. |
| 1327 | case elfcpp::R_386_COPY: |
| 1328 | case elfcpp::R_386_GLOB_DAT: |
| 1329 | case elfcpp::R_386_JUMP_SLOT: |
| 1330 | case elfcpp::R_386_RELATIVE: |
| 1331 | case elfcpp::R_386_TLS_TPOFF: |
| 1332 | case elfcpp::R_386_TLS_DTPMOD32: |
| 1333 | case elfcpp::R_386_TLS_DTPOFF32: |
| 1334 | case elfcpp::R_386_TLS_TPOFF32: |
| 1335 | case elfcpp::R_386_TLS_DESC: |
| 1336 | gold_error(_("%s: unexpected reloc %u in object file"), |
| 1337 | object->name().c_str(), r_type); |
| 1338 | break; |
| 1339 | |
| 1340 | // These are initial tls relocs, which are expected when |
| 1341 | // linking. |
| 1342 | case elfcpp::R_386_TLS_GD: // Global-dynamic |
| 1343 | case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url) |
| 1344 | case elfcpp::R_386_TLS_DESC_CALL: |
| 1345 | case elfcpp::R_386_TLS_LDM: // Local-dynamic |
| 1346 | case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic |
| 1347 | case elfcpp::R_386_TLS_IE: // Initial-exec |
| 1348 | case elfcpp::R_386_TLS_IE_32: |
| 1349 | case elfcpp::R_386_TLS_GOTIE: |
| 1350 | case elfcpp::R_386_TLS_LE: // Local-exec |
| 1351 | case elfcpp::R_386_TLS_LE_32: |
| 1352 | { |
| 1353 | const bool is_final = gsym->final_value_is_known(); |
| 1354 | const tls::Tls_optimization optimized_type |
| 1355 | = Target_i386::optimize_tls_reloc(is_final, r_type); |
| 1356 | switch (r_type) |
| 1357 | { |
| 1358 | case elfcpp::R_386_TLS_GD: // Global-dynamic |
| 1359 | if (optimized_type == tls::TLSOPT_NONE) |
| 1360 | { |
| 1361 | // Create a pair of GOT entries for the module index and |
| 1362 | // dtv-relative offset. |
| 1363 | Output_data_got<32, false>* got |
| 1364 | = target->got_section(symtab, layout); |
| 1365 | got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR, |
| 1366 | target->rel_dyn_section(layout), |
| 1367 | elfcpp::R_386_TLS_DTPMOD32, |
| 1368 | elfcpp::R_386_TLS_DTPOFF32); |
| 1369 | } |
| 1370 | else if (optimized_type == tls::TLSOPT_TO_IE) |
| 1371 | { |
| 1372 | // Create a GOT entry for the tp-relative offset. |
| 1373 | Output_data_got<32, false>* got |
| 1374 | = target->got_section(symtab, layout); |
| 1375 | got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET, |
| 1376 | target->rel_dyn_section(layout), |
| 1377 | elfcpp::R_386_TLS_TPOFF); |
| 1378 | } |
| 1379 | else if (optimized_type != tls::TLSOPT_TO_LE) |
| 1380 | unsupported_reloc_global(object, r_type, gsym); |
| 1381 | break; |
| 1382 | |
| 1383 | case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (~oliva url) |
| 1384 | target->define_tls_base_symbol(symtab, layout); |
| 1385 | if (optimized_type == tls::TLSOPT_NONE) |
| 1386 | { |
| 1387 | // Create a double GOT entry with an R_386_TLS_DESC reloc. |
| 1388 | Output_data_got<32, false>* got |
| 1389 | = target->got_section(symtab, layout); |
| 1390 | got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC, |
| 1391 | target->rel_dyn_section(layout), |
| 1392 | elfcpp::R_386_TLS_DESC, 0); |
| 1393 | } |
| 1394 | else if (optimized_type == tls::TLSOPT_TO_IE) |
| 1395 | { |
| 1396 | // Create a GOT entry for the tp-relative offset. |
| 1397 | Output_data_got<32, false>* got |
| 1398 | = target->got_section(symtab, layout); |
| 1399 | got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET, |
| 1400 | target->rel_dyn_section(layout), |
| 1401 | elfcpp::R_386_TLS_TPOFF); |
| 1402 | } |
| 1403 | else if (optimized_type != tls::TLSOPT_TO_LE) |
| 1404 | unsupported_reloc_global(object, r_type, gsym); |
| 1405 | break; |
| 1406 | |
| 1407 | case elfcpp::R_386_TLS_DESC_CALL: |
| 1408 | break; |
| 1409 | |
| 1410 | case elfcpp::R_386_TLS_LDM: // Local-dynamic |
| 1411 | if (optimized_type == tls::TLSOPT_NONE) |
| 1412 | { |
| 1413 | // Create a GOT entry for the module index. |
| 1414 | target->got_mod_index_entry(symtab, layout, object); |
| 1415 | } |
| 1416 | else if (optimized_type != tls::TLSOPT_TO_LE) |
| 1417 | unsupported_reloc_global(object, r_type, gsym); |
| 1418 | break; |
| 1419 | |
| 1420 | case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic |
| 1421 | break; |
| 1422 | |
| 1423 | case elfcpp::R_386_TLS_IE: // Initial-exec |
| 1424 | case elfcpp::R_386_TLS_IE_32: |
| 1425 | case elfcpp::R_386_TLS_GOTIE: |
| 1426 | layout->set_has_static_tls(); |
| 1427 | if (optimized_type == tls::TLSOPT_NONE) |
| 1428 | { |
| 1429 | // For the R_386_TLS_IE relocation, we need to create a |
| 1430 | // dynamic relocation when building a shared library. |
| 1431 | if (r_type == elfcpp::R_386_TLS_IE |
| 1432 | && parameters->options().shared()) |
| 1433 | { |
| 1434 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
| 1435 | rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE, |
| 1436 | output_section, object, |
| 1437 | data_shndx, |
| 1438 | reloc.get_r_offset()); |
| 1439 | } |
| 1440 | // Create a GOT entry for the tp-relative offset. |
| 1441 | Output_data_got<32, false>* got |
| 1442 | = target->got_section(symtab, layout); |
| 1443 | unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32 |
| 1444 | ? elfcpp::R_386_TLS_TPOFF32 |
| 1445 | : elfcpp::R_386_TLS_TPOFF); |
| 1446 | unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32 |
| 1447 | ? GOT_TYPE_TLS_OFFSET |
| 1448 | : GOT_TYPE_TLS_NOFFSET); |
| 1449 | got->add_global_with_rel(gsym, got_type, |
| 1450 | target->rel_dyn_section(layout), |
| 1451 | dyn_r_type); |
| 1452 | } |
| 1453 | else if (optimized_type != tls::TLSOPT_TO_LE) |
| 1454 | unsupported_reloc_global(object, r_type, gsym); |
| 1455 | break; |
| 1456 | |
| 1457 | case elfcpp::R_386_TLS_LE: // Local-exec |
| 1458 | case elfcpp::R_386_TLS_LE_32: |
| 1459 | layout->set_has_static_tls(); |
| 1460 | if (parameters->options().shared()) |
| 1461 | { |
| 1462 | // We need to create a dynamic relocation. |
| 1463 | unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32 |
| 1464 | ? elfcpp::R_386_TLS_TPOFF32 |
| 1465 | : elfcpp::R_386_TLS_TPOFF); |
| 1466 | Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
| 1467 | rel_dyn->add_global(gsym, dyn_r_type, output_section, object, |
| 1468 | data_shndx, reloc.get_r_offset()); |
| 1469 | } |
| 1470 | break; |
| 1471 | |
| 1472 | default: |
| 1473 | gold_unreachable(); |
| 1474 | } |
| 1475 | } |
| 1476 | break; |
| 1477 | |
| 1478 | case elfcpp::R_386_32PLT: |
| 1479 | case elfcpp::R_386_TLS_GD_32: |
| 1480 | case elfcpp::R_386_TLS_GD_PUSH: |
| 1481 | case elfcpp::R_386_TLS_GD_CALL: |
| 1482 | case elfcpp::R_386_TLS_GD_POP: |
| 1483 | case elfcpp::R_386_TLS_LDM_32: |
| 1484 | case elfcpp::R_386_TLS_LDM_PUSH: |
| 1485 | case elfcpp::R_386_TLS_LDM_CALL: |
| 1486 | case elfcpp::R_386_TLS_LDM_POP: |
| 1487 | case elfcpp::R_386_USED_BY_INTEL_200: |
| 1488 | default: |
| 1489 | unsupported_reloc_global(object, r_type, gsym); |
| 1490 | break; |
| 1491 | } |
| 1492 | } |
| 1493 | |
| 1494 | // Process relocations for gc. |
| 1495 | |
| 1496 | void |
| 1497 | Target_i386::gc_process_relocs(const General_options& options, |
| 1498 | Symbol_table* symtab, |
| 1499 | Layout* layout, |
| 1500 | Sized_relobj<32, false>* object, |
| 1501 | unsigned int data_shndx, |
| 1502 | unsigned int, |
| 1503 | const unsigned char* prelocs, |
| 1504 | size_t reloc_count, |
| 1505 | Output_section* output_section, |
| 1506 | bool needs_special_offset_handling, |
| 1507 | size_t local_symbol_count, |
| 1508 | const unsigned char* plocal_symbols) |
| 1509 | { |
| 1510 | gold::gc_process_relocs<32, false, Target_i386, elfcpp::SHT_REL, |
| 1511 | Target_i386::Scan>( |
| 1512 | options, |
| 1513 | symtab, |
| 1514 | layout, |
| 1515 | this, |
| 1516 | object, |
| 1517 | data_shndx, |
| 1518 | prelocs, |
| 1519 | reloc_count, |
| 1520 | output_section, |
| 1521 | needs_special_offset_handling, |
| 1522 | local_symbol_count, |
| 1523 | plocal_symbols); |
| 1524 | } |
| 1525 | |
| 1526 | // Scan relocations for a section. |
| 1527 | |
| 1528 | void |
| 1529 | Target_i386::scan_relocs(const General_options& options, |
| 1530 | Symbol_table* symtab, |
| 1531 | Layout* layout, |
| 1532 | Sized_relobj<32, false>* object, |
| 1533 | unsigned int data_shndx, |
| 1534 | unsigned int sh_type, |
| 1535 | const unsigned char* prelocs, |
| 1536 | size_t reloc_count, |
| 1537 | Output_section* output_section, |
| 1538 | bool needs_special_offset_handling, |
| 1539 | size_t local_symbol_count, |
| 1540 | const unsigned char* plocal_symbols) |
| 1541 | { |
| 1542 | if (sh_type == elfcpp::SHT_RELA) |
| 1543 | { |
| 1544 | gold_error(_("%s: unsupported RELA reloc section"), |
| 1545 | object->name().c_str()); |
| 1546 | return; |
| 1547 | } |
| 1548 | |
| 1549 | gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL, |
| 1550 | Target_i386::Scan>( |
| 1551 | options, |
| 1552 | symtab, |
| 1553 | layout, |
| 1554 | this, |
| 1555 | object, |
| 1556 | data_shndx, |
| 1557 | prelocs, |
| 1558 | reloc_count, |
| 1559 | output_section, |
| 1560 | needs_special_offset_handling, |
| 1561 | local_symbol_count, |
| 1562 | plocal_symbols); |
| 1563 | } |
| 1564 | |
| 1565 | // Finalize the sections. |
| 1566 | |
| 1567 | void |
| 1568 | Target_i386::do_finalize_sections(Layout* layout) |
| 1569 | { |
| 1570 | // Fill in some more dynamic tags. |
| 1571 | Output_data_dynamic* const odyn = layout->dynamic_data(); |
| 1572 | if (odyn != NULL) |
| 1573 | { |
| 1574 | if (this->got_plt_ != NULL) |
| 1575 | odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_); |
| 1576 | |
| 1577 | if (this->plt_ != NULL) |
| 1578 | { |
| 1579 | const Output_data* od = this->plt_->rel_plt(); |
| 1580 | odyn->add_section_size(elfcpp::DT_PLTRELSZ, od); |
| 1581 | odyn->add_section_address(elfcpp::DT_JMPREL, od); |
| 1582 | odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_REL); |
| 1583 | } |
| 1584 | |
| 1585 | if (this->rel_dyn_ != NULL) |
| 1586 | { |
| 1587 | const Output_data* od = this->rel_dyn_; |
| 1588 | odyn->add_section_address(elfcpp::DT_REL, od); |
| 1589 | odyn->add_section_size(elfcpp::DT_RELSZ, od); |
| 1590 | odyn->add_constant(elfcpp::DT_RELENT, |
| 1591 | elfcpp::Elf_sizes<32>::rel_size); |
| 1592 | } |
| 1593 | |
| 1594 | if (!parameters->options().shared()) |
| 1595 | { |
| 1596 | // The value of the DT_DEBUG tag is filled in by the dynamic |
| 1597 | // linker at run time, and used by the debugger. |
| 1598 | odyn->add_constant(elfcpp::DT_DEBUG, 0); |
| 1599 | } |
| 1600 | } |
| 1601 | |
| 1602 | // Emit any relocs we saved in an attempt to avoid generating COPY |
| 1603 | // relocs. |
| 1604 | if (this->copy_relocs_.any_saved_relocs()) |
| 1605 | this->copy_relocs_.emit(this->rel_dyn_section(layout)); |
| 1606 | } |
| 1607 | |
| 1608 | // Return whether a direct absolute static relocation needs to be applied. |
| 1609 | // In cases where Scan::local() or Scan::global() has created |
| 1610 | // a dynamic relocation other than R_386_RELATIVE, the addend |
| 1611 | // of the relocation is carried in the data, and we must not |
| 1612 | // apply the static relocation. |
| 1613 | |
| 1614 | inline bool |
| 1615 | Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol<32>* gsym, |
| 1616 | int ref_flags, |
| 1617 | bool is_32bit, |
| 1618 | Output_section* output_section) |
| 1619 | { |
| 1620 | // If the output section is not allocated, then we didn't call |
| 1621 | // scan_relocs, we didn't create a dynamic reloc, and we must apply |
| 1622 | // the reloc here. |
| 1623 | if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0) |
| 1624 | return true; |
| 1625 | |
| 1626 | // For local symbols, we will have created a non-RELATIVE dynamic |
| 1627 | // relocation only if (a) the output is position independent, |
| 1628 | // (b) the relocation is absolute (not pc- or segment-relative), and |
| 1629 | // (c) the relocation is not 32 bits wide. |
| 1630 | if (gsym == NULL) |
| 1631 | return !(parameters->options().output_is_position_independent() |
| 1632 | && (ref_flags & Symbol::ABSOLUTE_REF) |
| 1633 | && !is_32bit); |
| 1634 | |
| 1635 | // For global symbols, we use the same helper routines used in the |
| 1636 | // scan pass. If we did not create a dynamic relocation, or if we |
| 1637 | // created a RELATIVE dynamic relocation, we should apply the static |
| 1638 | // relocation. |
| 1639 | bool has_dyn = gsym->needs_dynamic_reloc(ref_flags); |
| 1640 | bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF) |
| 1641 | && gsym->can_use_relative_reloc(ref_flags |
| 1642 | & Symbol::FUNCTION_CALL); |
| 1643 | return !has_dyn || is_rel; |
| 1644 | } |
| 1645 | |
| 1646 | // Perform a relocation. |
| 1647 | |
| 1648 | inline bool |
| 1649 | Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo, |
| 1650 | Target_i386* target, |
| 1651 | Output_section *output_section, |
| 1652 | size_t relnum, |
| 1653 | const elfcpp::Rel<32, false>& rel, |
| 1654 | unsigned int r_type, |
| 1655 | const Sized_symbol<32>* gsym, |
| 1656 | const Symbol_value<32>* psymval, |
| 1657 | unsigned char* view, |
| 1658 | elfcpp::Elf_types<32>::Elf_Addr address, |
| 1659 | section_size_type view_size) |
| 1660 | { |
| 1661 | if (this->skip_call_tls_get_addr_) |
| 1662 | { |
| 1663 | if ((r_type != elfcpp::R_386_PLT32 |
| 1664 | && r_type != elfcpp::R_386_PC32) |
| 1665 | || gsym == NULL |
| 1666 | || strcmp(gsym->name(), "___tls_get_addr") != 0) |
| 1667 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
| 1668 | _("missing expected TLS relocation")); |
| 1669 | else |
| 1670 | { |
| 1671 | this->skip_call_tls_get_addr_ = false; |
| 1672 | return false; |
| 1673 | } |
| 1674 | } |
| 1675 | |
| 1676 | // Pick the value to use for symbols defined in shared objects. |
| 1677 | Symbol_value<32> symval; |
| 1678 | if (gsym != NULL |
| 1679 | && gsym->use_plt_offset(r_type == elfcpp::R_386_PC8 |
| 1680 | || r_type == elfcpp::R_386_PC16 |
| 1681 | || r_type == elfcpp::R_386_PC32)) |
| 1682 | { |
| 1683 | symval.set_output_value(target->plt_section()->address() |
| 1684 | + gsym->plt_offset()); |
| 1685 | psymval = &symval; |
| 1686 | } |
| 1687 | |
| 1688 | const Sized_relobj<32, false>* object = relinfo->object; |
| 1689 | |
| 1690 | // Get the GOT offset if needed. |
| 1691 | // The GOT pointer points to the end of the GOT section. |
| 1692 | // We need to subtract the size of the GOT section to get |
| 1693 | // the actual offset to use in the relocation. |
| 1694 | bool have_got_offset = false; |
| 1695 | unsigned int got_offset = 0; |
| 1696 | switch (r_type) |
| 1697 | { |
| 1698 | case elfcpp::R_386_GOT32: |
| 1699 | if (gsym != NULL) |
| 1700 | { |
| 1701 | gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD)); |
| 1702 | got_offset = (gsym->got_offset(GOT_TYPE_STANDARD) |
| 1703 | - target->got_size()); |
| 1704 | } |
| 1705 | else |
| 1706 | { |
| 1707 | unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info()); |
| 1708 | gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD)); |
| 1709 | got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD) |
| 1710 | - target->got_size()); |
| 1711 | } |
| 1712 | have_got_offset = true; |
| 1713 | break; |
| 1714 | |
| 1715 | default: |
| 1716 | break; |
| 1717 | } |
| 1718 | |
| 1719 | switch (r_type) |
| 1720 | { |
| 1721 | case elfcpp::R_386_NONE: |
| 1722 | case elfcpp::R_386_GNU_VTINHERIT: |
| 1723 | case elfcpp::R_386_GNU_VTENTRY: |
| 1724 | break; |
| 1725 | |
| 1726 | case elfcpp::R_386_32: |
| 1727 | if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true, |
| 1728 | output_section)) |
| 1729 | Relocate_functions<32, false>::rel32(view, object, psymval); |
| 1730 | break; |
| 1731 | |
| 1732 | case elfcpp::R_386_PC32: |
| 1733 | { |
| 1734 | int ref_flags = Symbol::NON_PIC_REF; |
| 1735 | if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC) |
| 1736 | ref_flags |= Symbol::FUNCTION_CALL; |
| 1737 | if (should_apply_static_reloc(gsym, ref_flags, true, output_section)) |
| 1738 | Relocate_functions<32, false>::pcrel32(view, object, psymval, address); |
| 1739 | } |
| 1740 | break; |
| 1741 | |
| 1742 | case elfcpp::R_386_16: |
| 1743 | if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false, |
| 1744 | output_section)) |
| 1745 | Relocate_functions<32, false>::rel16(view, object, psymval); |
| 1746 | break; |
| 1747 | |
| 1748 | case elfcpp::R_386_PC16: |
| 1749 | { |
| 1750 | int ref_flags = Symbol::NON_PIC_REF; |
| 1751 | if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC) |
| 1752 | ref_flags |= Symbol::FUNCTION_CALL; |
| 1753 | if (should_apply_static_reloc(gsym, ref_flags, false, output_section)) |
| 1754 | Relocate_functions<32, false>::pcrel16(view, object, psymval, address); |
| 1755 | } |
| 1756 | break; |
| 1757 | |
| 1758 | case elfcpp::R_386_8: |
| 1759 | if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false, |
| 1760 | output_section)) |
| 1761 | Relocate_functions<32, false>::rel8(view, object, psymval); |
| 1762 | break; |
| 1763 | |
| 1764 | case elfcpp::R_386_PC8: |
| 1765 | { |
| 1766 | int ref_flags = Symbol::NON_PIC_REF; |
| 1767 | if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC) |
| 1768 | ref_flags |= Symbol::FUNCTION_CALL; |
| 1769 | if (should_apply_static_reloc(gsym, ref_flags, false, |
| 1770 | output_section)) |
| 1771 | Relocate_functions<32, false>::pcrel8(view, object, psymval, address); |
| 1772 | } |
| 1773 | break; |
| 1774 | |
| 1775 | case elfcpp::R_386_PLT32: |
| 1776 | gold_assert(gsym == NULL |
| 1777 | || gsym->has_plt_offset() |
| 1778 | || gsym->final_value_is_known() |
| 1779 | || (gsym->is_defined() |
| 1780 | && !gsym->is_from_dynobj() |
| 1781 | && !gsym->is_preemptible())); |
| 1782 | Relocate_functions<32, false>::pcrel32(view, object, psymval, address); |
| 1783 | break; |
| 1784 | |
| 1785 | case elfcpp::R_386_GOT32: |
| 1786 | gold_assert(have_got_offset); |
| 1787 | Relocate_functions<32, false>::rel32(view, got_offset); |
| 1788 | break; |
| 1789 | |
| 1790 | case elfcpp::R_386_GOTOFF: |
| 1791 | { |
| 1792 | elfcpp::Elf_types<32>::Elf_Addr value; |
| 1793 | value = (psymval->value(object, 0) |
| 1794 | - target->got_plt_section()->address()); |
| 1795 | Relocate_functions<32, false>::rel32(view, value); |
| 1796 | } |
| 1797 | break; |
| 1798 | |
| 1799 | case elfcpp::R_386_GOTPC: |
| 1800 | { |
| 1801 | elfcpp::Elf_types<32>::Elf_Addr value; |
| 1802 | value = target->got_plt_section()->address(); |
| 1803 | Relocate_functions<32, false>::pcrel32(view, value, address); |
| 1804 | } |
| 1805 | break; |
| 1806 | |
| 1807 | case elfcpp::R_386_COPY: |
| 1808 | case elfcpp::R_386_GLOB_DAT: |
| 1809 | case elfcpp::R_386_JUMP_SLOT: |
| 1810 | case elfcpp::R_386_RELATIVE: |
| 1811 | // These are outstanding tls relocs, which are unexpected when |
| 1812 | // linking. |
| 1813 | case elfcpp::R_386_TLS_TPOFF: |
| 1814 | case elfcpp::R_386_TLS_DTPMOD32: |
| 1815 | case elfcpp::R_386_TLS_DTPOFF32: |
| 1816 | case elfcpp::R_386_TLS_TPOFF32: |
| 1817 | case elfcpp::R_386_TLS_DESC: |
| 1818 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
| 1819 | _("unexpected reloc %u in object file"), |
| 1820 | r_type); |
| 1821 | break; |
| 1822 | |
| 1823 | // These are initial tls relocs, which are expected when |
| 1824 | // linking. |
| 1825 | case elfcpp::R_386_TLS_GD: // Global-dynamic |
| 1826 | case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url) |
| 1827 | case elfcpp::R_386_TLS_DESC_CALL: |
| 1828 | case elfcpp::R_386_TLS_LDM: // Local-dynamic |
| 1829 | case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic |
| 1830 | case elfcpp::R_386_TLS_IE: // Initial-exec |
| 1831 | case elfcpp::R_386_TLS_IE_32: |
| 1832 | case elfcpp::R_386_TLS_GOTIE: |
| 1833 | case elfcpp::R_386_TLS_LE: // Local-exec |
| 1834 | case elfcpp::R_386_TLS_LE_32: |
| 1835 | this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval, |
| 1836 | view, address, view_size); |
| 1837 | break; |
| 1838 | |
| 1839 | case elfcpp::R_386_32PLT: |
| 1840 | case elfcpp::R_386_TLS_GD_32: |
| 1841 | case elfcpp::R_386_TLS_GD_PUSH: |
| 1842 | case elfcpp::R_386_TLS_GD_CALL: |
| 1843 | case elfcpp::R_386_TLS_GD_POP: |
| 1844 | case elfcpp::R_386_TLS_LDM_32: |
| 1845 | case elfcpp::R_386_TLS_LDM_PUSH: |
| 1846 | case elfcpp::R_386_TLS_LDM_CALL: |
| 1847 | case elfcpp::R_386_TLS_LDM_POP: |
| 1848 | case elfcpp::R_386_USED_BY_INTEL_200: |
| 1849 | default: |
| 1850 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
| 1851 | _("unsupported reloc %u"), |
| 1852 | r_type); |
| 1853 | break; |
| 1854 | } |
| 1855 | |
| 1856 | return true; |
| 1857 | } |
| 1858 | |
| 1859 | // Perform a TLS relocation. |
| 1860 | |
| 1861 | inline void |
| 1862 | Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo, |
| 1863 | Target_i386* target, |
| 1864 | size_t relnum, |
| 1865 | const elfcpp::Rel<32, false>& rel, |
| 1866 | unsigned int r_type, |
| 1867 | const Sized_symbol<32>* gsym, |
| 1868 | const Symbol_value<32>* psymval, |
| 1869 | unsigned char* view, |
| 1870 | elfcpp::Elf_types<32>::Elf_Addr, |
| 1871 | section_size_type view_size) |
| 1872 | { |
| 1873 | Output_segment* tls_segment = relinfo->layout->tls_segment(); |
| 1874 | |
| 1875 | const Sized_relobj<32, false>* object = relinfo->object; |
| 1876 | |
| 1877 | elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0); |
| 1878 | |
| 1879 | const bool is_final = |
| 1880 | (gsym == NULL |
| 1881 | ? !parameters->options().output_is_position_independent() |
| 1882 | : gsym->final_value_is_known()); |
| 1883 | const tls::Tls_optimization optimized_type |
| 1884 | = Target_i386::optimize_tls_reloc(is_final, r_type); |
| 1885 | switch (r_type) |
| 1886 | { |
| 1887 | case elfcpp::R_386_TLS_GD: // Global-dynamic |
| 1888 | if (optimized_type == tls::TLSOPT_TO_LE) |
| 1889 | { |
| 1890 | gold_assert(tls_segment != NULL); |
| 1891 | this->tls_gd_to_le(relinfo, relnum, tls_segment, |
| 1892 | rel, r_type, value, view, |
| 1893 | view_size); |
| 1894 | break; |
| 1895 | } |
| 1896 | else |
| 1897 | { |
| 1898 | unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE |
| 1899 | ? GOT_TYPE_TLS_NOFFSET |
| 1900 | : GOT_TYPE_TLS_PAIR); |
| 1901 | unsigned int got_offset; |
| 1902 | if (gsym != NULL) |
| 1903 | { |
| 1904 | gold_assert(gsym->has_got_offset(got_type)); |
| 1905 | got_offset = gsym->got_offset(got_type) - target->got_size(); |
| 1906 | } |
| 1907 | else |
| 1908 | { |
| 1909 | unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info()); |
| 1910 | gold_assert(object->local_has_got_offset(r_sym, got_type)); |
| 1911 | got_offset = (object->local_got_offset(r_sym, got_type) |
| 1912 | - target->got_size()); |
| 1913 | } |
| 1914 | if (optimized_type == tls::TLSOPT_TO_IE) |
| 1915 | { |
| 1916 | gold_assert(tls_segment != NULL); |
| 1917 | this->tls_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type, |
| 1918 | got_offset, view, view_size); |
| 1919 | break; |
| 1920 | } |
| 1921 | else if (optimized_type == tls::TLSOPT_NONE) |
| 1922 | { |
| 1923 | // Relocate the field with the offset of the pair of GOT |
| 1924 | // entries. |
| 1925 | Relocate_functions<32, false>::rel32(view, got_offset); |
| 1926 | break; |
| 1927 | } |
| 1928 | } |
| 1929 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
| 1930 | _("unsupported reloc %u"), |
| 1931 | r_type); |
| 1932 | break; |
| 1933 | |
| 1934 | case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url) |
| 1935 | case elfcpp::R_386_TLS_DESC_CALL: |
| 1936 | this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU; |
| 1937 | if (optimized_type == tls::TLSOPT_TO_LE) |
| 1938 | { |
| 1939 | gold_assert(tls_segment != NULL); |
| 1940 | this->tls_desc_gd_to_le(relinfo, relnum, tls_segment, |
| 1941 | rel, r_type, value, view, |
| 1942 | view_size); |
| 1943 | break; |
| 1944 | } |
| 1945 | else |
| 1946 | { |
| 1947 | unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE |
| 1948 | ? GOT_TYPE_TLS_NOFFSET |
| 1949 | : GOT_TYPE_TLS_DESC); |
| 1950 | unsigned int got_offset; |
| 1951 | if (gsym != NULL) |
| 1952 | { |
| 1953 | gold_assert(gsym->has_got_offset(got_type)); |
| 1954 | got_offset = gsym->got_offset(got_type) - target->got_size(); |
| 1955 | } |
| 1956 | else |
| 1957 | { |
| 1958 | unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info()); |
| 1959 | gold_assert(object->local_has_got_offset(r_sym, got_type)); |
| 1960 | got_offset = (object->local_got_offset(r_sym, got_type) |
| 1961 | - target->got_size()); |
| 1962 | } |
| 1963 | if (optimized_type == tls::TLSOPT_TO_IE) |
| 1964 | { |
| 1965 | gold_assert(tls_segment != NULL); |
| 1966 | this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type, |
| 1967 | got_offset, view, view_size); |
| 1968 | break; |
| 1969 | } |
| 1970 | else if (optimized_type == tls::TLSOPT_NONE) |
| 1971 | { |
| 1972 | if (r_type == elfcpp::R_386_TLS_GOTDESC) |
| 1973 | { |
| 1974 | // Relocate the field with the offset of the pair of GOT |
| 1975 | // entries. |
| 1976 | Relocate_functions<32, false>::rel32(view, got_offset); |
| 1977 | } |
| 1978 | break; |
| 1979 | } |
| 1980 | } |
| 1981 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
| 1982 | _("unsupported reloc %u"), |
| 1983 | r_type); |
| 1984 | break; |
| 1985 | |
| 1986 | case elfcpp::R_386_TLS_LDM: // Local-dynamic |
| 1987 | if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN) |
| 1988 | { |
| 1989 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
| 1990 | _("both SUN and GNU model " |
| 1991 | "TLS relocations")); |
| 1992 | break; |
| 1993 | } |
| 1994 | this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU; |
| 1995 | if (optimized_type == tls::TLSOPT_TO_LE) |
| 1996 | { |
| 1997 | gold_assert(tls_segment != NULL); |
| 1998 | this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, r_type, |
| 1999 | value, view, view_size); |
| 2000 | break; |
| 2001 | } |
| 2002 | else if (optimized_type == tls::TLSOPT_NONE) |
| 2003 | { |
| 2004 | // Relocate the field with the offset of the GOT entry for |
| 2005 | // the module index. |
| 2006 | unsigned int got_offset; |
| 2007 | got_offset = (target->got_mod_index_entry(NULL, NULL, NULL) |
| 2008 | - target->got_size()); |
| 2009 | Relocate_functions<32, false>::rel32(view, got_offset); |
| 2010 | break; |
| 2011 | } |
| 2012 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
| 2013 | _("unsupported reloc %u"), |
| 2014 | r_type); |
| 2015 | break; |
| 2016 | |
| 2017 | case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic |
| 2018 | // This reloc can appear in debugging sections, in which case we |
| 2019 | // won't see the TLS_LDM reloc. The local_dynamic_type field |
| 2020 | // tells us this. |
| 2021 | if (optimized_type == tls::TLSOPT_TO_LE |
| 2022 | && this->local_dynamic_type_ != LOCAL_DYNAMIC_NONE) |
| 2023 | { |
| 2024 | gold_assert(tls_segment != NULL); |
| 2025 | value -= tls_segment->memsz(); |
| 2026 | } |
| 2027 | Relocate_functions<32, false>::rel32(view, value); |
| 2028 | break; |
| 2029 | |
| 2030 | case elfcpp::R_386_TLS_IE: // Initial-exec |
| 2031 | case elfcpp::R_386_TLS_GOTIE: |
| 2032 | case elfcpp::R_386_TLS_IE_32: |
| 2033 | if (optimized_type == tls::TLSOPT_TO_LE) |
| 2034 | { |
| 2035 | gold_assert(tls_segment != NULL); |
| 2036 | Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment, |
| 2037 | rel, r_type, value, view, |
| 2038 | view_size); |
| 2039 | break; |
| 2040 | } |
| 2041 | else if (optimized_type == tls::TLSOPT_NONE) |
| 2042 | { |
| 2043 | // Relocate the field with the offset of the GOT entry for |
| 2044 | // the tp-relative offset of the symbol. |
| 2045 | unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32 |
| 2046 | ? GOT_TYPE_TLS_OFFSET |
| 2047 | : GOT_TYPE_TLS_NOFFSET); |
| 2048 | unsigned int got_offset; |
| 2049 | if (gsym != NULL) |
| 2050 | { |
| 2051 | gold_assert(gsym->has_got_offset(got_type)); |
| 2052 | got_offset = gsym->got_offset(got_type); |
| 2053 | } |
| 2054 | else |
| 2055 | { |
| 2056 | unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info()); |
| 2057 | gold_assert(object->local_has_got_offset(r_sym, got_type)); |
| 2058 | got_offset = object->local_got_offset(r_sym, got_type); |
| 2059 | } |
| 2060 | // For the R_386_TLS_IE relocation, we need to apply the |
| 2061 | // absolute address of the GOT entry. |
| 2062 | if (r_type == elfcpp::R_386_TLS_IE) |
| 2063 | got_offset += target->got_plt_section()->address(); |
| 2064 | // All GOT offsets are relative to the end of the GOT. |
| 2065 | got_offset -= target->got_size(); |
| 2066 | Relocate_functions<32, false>::rel32(view, got_offset); |
| 2067 | break; |
| 2068 | } |
| 2069 | gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
| 2070 | _("unsupported reloc %u"), |
| 2071 | r_type); |
| 2072 | break; |
| 2073 | |
| 2074 | case elfcpp::R_386_TLS_LE: // Local-exec |
| 2075 | // If we're creating a shared library, a dynamic relocation will |
| 2076 | // have been created for this location, so do not apply it now. |
| 2077 | if (!parameters->options().shared()) |
| 2078 | { |
| 2079 | gold_assert(tls_segment != NULL); |
| 2080 | value -= tls_segment->memsz(); |
| 2081 | Relocate_functions<32, false>::rel32(view, value); |
| 2082 | } |
| 2083 | break; |
| 2084 | |
| 2085 | case elfcpp::R_386_TLS_LE_32: |
| 2086 | // If we're creating a shared library, a dynamic relocation will |
| 2087 | // have been created for this location, so do not apply it now. |
| 2088 | if (!parameters->options().shared()) |
| 2089 | { |
| 2090 | gold_assert(tls_segment != NULL); |
| 2091 | value = tls_segment->memsz() - value; |
| 2092 | Relocate_functions<32, false>::rel32(view, value); |
| 2093 | } |
| 2094 | break; |
| 2095 | } |
| 2096 | } |
| 2097 | |
| 2098 | // Do a relocation in which we convert a TLS General-Dynamic to a |
| 2099 | // Local-Exec. |
| 2100 | |
| 2101 | inline void |
| 2102 | Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo, |
| 2103 | size_t relnum, |
| 2104 | Output_segment* tls_segment, |
| 2105 | const elfcpp::Rel<32, false>& rel, |
| 2106 | unsigned int, |
| 2107 | elfcpp::Elf_types<32>::Elf_Addr value, |
| 2108 | unsigned char* view, |
| 2109 | section_size_type view_size) |
| 2110 | { |
| 2111 | // leal foo(,%reg,1),%eax; call ___tls_get_addr |
| 2112 | // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax |
| 2113 | // leal foo(%reg),%eax; call ___tls_get_addr |
| 2114 | // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax |
| 2115 | |
| 2116 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2); |
| 2117 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9); |
| 2118 | |
| 2119 | unsigned char op1 = view[-1]; |
| 2120 | unsigned char op2 = view[-2]; |
| 2121 | |
| 2122 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
| 2123 | op2 == 0x8d || op2 == 0x04); |
| 2124 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8); |
| 2125 | |
| 2126 | int roff = 5; |
| 2127 | |
| 2128 | if (op2 == 0x04) |
| 2129 | { |
| 2130 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3); |
| 2131 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d); |
| 2132 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
| 2133 | ((op1 & 0xc7) == 0x05 && op1 != (4 << 3))); |
| 2134 | memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12); |
| 2135 | } |
| 2136 | else |
| 2137 | { |
| 2138 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
| 2139 | (op1 & 0xf8) == 0x80 && (op1 & 7) != 4); |
| 2140 | if (rel.get_r_offset() + 9 < view_size |
| 2141 | && view[9] == 0x90) |
| 2142 | { |
| 2143 | // There is a trailing nop. Use the size byte subl. |
| 2144 | memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12); |
| 2145 | roff = 6; |
| 2146 | } |
| 2147 | else |
| 2148 | { |
| 2149 | // Use the five byte subl. |
| 2150 | memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11); |
| 2151 | } |
| 2152 | } |
| 2153 | |
| 2154 | value = tls_segment->memsz() - value; |
| 2155 | Relocate_functions<32, false>::rel32(view + roff, value); |
| 2156 | |
| 2157 | // The next reloc should be a PLT32 reloc against __tls_get_addr. |
| 2158 | // We can skip it. |
| 2159 | this->skip_call_tls_get_addr_ = true; |
| 2160 | } |
| 2161 | |
| 2162 | // Do a relocation in which we convert a TLS General-Dynamic to an |
| 2163 | // Initial-Exec. |
| 2164 | |
| 2165 | inline void |
| 2166 | Target_i386::Relocate::tls_gd_to_ie(const Relocate_info<32, false>* relinfo, |
| 2167 | size_t relnum, |
| 2168 | Output_segment*, |
| 2169 | const elfcpp::Rel<32, false>& rel, |
| 2170 | unsigned int, |
| 2171 | elfcpp::Elf_types<32>::Elf_Addr value, |
| 2172 | unsigned char* view, |
| 2173 | section_size_type view_size) |
| 2174 | { |
| 2175 | // leal foo(,%ebx,1),%eax; call ___tls_get_addr |
| 2176 | // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax |
| 2177 | |
| 2178 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2); |
| 2179 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9); |
| 2180 | |
| 2181 | unsigned char op1 = view[-1]; |
| 2182 | unsigned char op2 = view[-2]; |
| 2183 | |
| 2184 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
| 2185 | op2 == 0x8d || op2 == 0x04); |
| 2186 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8); |
| 2187 | |
| 2188 | int roff = 5; |
| 2189 | |
| 2190 | // FIXME: For now, support only the first (SIB) form. |
| 2191 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), op2 == 0x04); |
| 2192 | |
| 2193 | if (op2 == 0x04) |
| 2194 | { |
| 2195 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3); |
| 2196 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d); |
| 2197 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
| 2198 | ((op1 & 0xc7) == 0x05 && op1 != (4 << 3))); |
| 2199 | memcpy(view - 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12); |
| 2200 | } |
| 2201 | else |
| 2202 | { |
| 2203 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
| 2204 | (op1 & 0xf8) == 0x80 && (op1 & 7) != 4); |
| 2205 | if (rel.get_r_offset() + 9 < view_size |
| 2206 | && view[9] == 0x90) |
| 2207 | { |
| 2208 | // FIXME: This is not the right instruction sequence. |
| 2209 | // There is a trailing nop. Use the size byte subl. |
| 2210 | memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12); |
| 2211 | roff = 6; |
| 2212 | } |
| 2213 | else |
| 2214 | { |
| 2215 | // FIXME: This is not the right instruction sequence. |
| 2216 | // Use the five byte subl. |
| 2217 | memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11); |
| 2218 | } |
| 2219 | } |
| 2220 | |
| 2221 | Relocate_functions<32, false>::rel32(view + roff, value); |
| 2222 | |
| 2223 | // The next reloc should be a PLT32 reloc against __tls_get_addr. |
| 2224 | // We can skip it. |
| 2225 | this->skip_call_tls_get_addr_ = true; |
| 2226 | } |
| 2227 | |
| 2228 | // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL |
| 2229 | // General-Dynamic to a Local-Exec. |
| 2230 | |
| 2231 | inline void |
| 2232 | Target_i386::Relocate::tls_desc_gd_to_le( |
| 2233 | const Relocate_info<32, false>* relinfo, |
| 2234 | size_t relnum, |
| 2235 | Output_segment* tls_segment, |
| 2236 | const elfcpp::Rel<32, false>& rel, |
| 2237 | unsigned int r_type, |
| 2238 | elfcpp::Elf_types<32>::Elf_Addr value, |
| 2239 | unsigned char* view, |
| 2240 | section_size_type view_size) |
| 2241 | { |
| 2242 | if (r_type == elfcpp::R_386_TLS_GOTDESC) |
| 2243 | { |
| 2244 | // leal foo@TLSDESC(%ebx), %eax |
| 2245 | // ==> leal foo@NTPOFF, %eax |
| 2246 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2); |
| 2247 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4); |
| 2248 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
| 2249 | view[-2] == 0x8d && view[-1] == 0x83); |
| 2250 | view[-1] = 0x05; |
| 2251 | value -= tls_segment->memsz(); |
| 2252 | Relocate_functions<32, false>::rel32(view, value); |
| 2253 | } |
| 2254 | else |
| 2255 | { |
| 2256 | // call *foo@TLSCALL(%eax) |
| 2257 | // ==> nop; nop |
| 2258 | gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL); |
| 2259 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2); |
| 2260 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
| 2261 | view[0] == 0xff && view[1] == 0x10); |
| 2262 | view[0] = 0x66; |
| 2263 | view[1] = 0x90; |
| 2264 | } |
| 2265 | } |
| 2266 | |
| 2267 | // Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL |
| 2268 | // General-Dynamic to an Initial-Exec. |
| 2269 | |
| 2270 | inline void |
| 2271 | Target_i386::Relocate::tls_desc_gd_to_ie( |
| 2272 | const Relocate_info<32, false>* relinfo, |
| 2273 | size_t relnum, |
| 2274 | Output_segment*, |
| 2275 | const elfcpp::Rel<32, false>& rel, |
| 2276 | unsigned int r_type, |
| 2277 | elfcpp::Elf_types<32>::Elf_Addr value, |
| 2278 | unsigned char* view, |
| 2279 | section_size_type view_size) |
| 2280 | { |
| 2281 | if (r_type == elfcpp::R_386_TLS_GOTDESC) |
| 2282 | { |
| 2283 | // leal foo@TLSDESC(%ebx), %eax |
| 2284 | // ==> movl foo@GOTNTPOFF(%ebx), %eax |
| 2285 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2); |
| 2286 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4); |
| 2287 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
| 2288 | view[-2] == 0x8d && view[-1] == 0x83); |
| 2289 | view[-2] = 0x8b; |
| 2290 | Relocate_functions<32, false>::rel32(view, value); |
| 2291 | } |
| 2292 | else |
| 2293 | { |
| 2294 | // call *foo@TLSCALL(%eax) |
| 2295 | // ==> nop; nop |
| 2296 | gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL); |
| 2297 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2); |
| 2298 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
| 2299 | view[0] == 0xff && view[1] == 0x10); |
| 2300 | view[0] = 0x66; |
| 2301 | view[1] = 0x90; |
| 2302 | } |
| 2303 | } |
| 2304 | |
| 2305 | // Do a relocation in which we convert a TLS Local-Dynamic to a |
| 2306 | // Local-Exec. |
| 2307 | |
| 2308 | inline void |
| 2309 | Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo, |
| 2310 | size_t relnum, |
| 2311 | Output_segment*, |
| 2312 | const elfcpp::Rel<32, false>& rel, |
| 2313 | unsigned int, |
| 2314 | elfcpp::Elf_types<32>::Elf_Addr, |
| 2315 | unsigned char* view, |
| 2316 | section_size_type view_size) |
| 2317 | { |
| 2318 | // leal foo(%reg), %eax; call ___tls_get_addr |
| 2319 | // ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi |
| 2320 | |
| 2321 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2); |
| 2322 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9); |
| 2323 | |
| 2324 | // FIXME: Does this test really always pass? |
| 2325 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
| 2326 | view[-2] == 0x8d && view[-1] == 0x83); |
| 2327 | |
| 2328 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8); |
| 2329 | |
| 2330 | memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11); |
| 2331 | |
| 2332 | // The next reloc should be a PLT32 reloc against __tls_get_addr. |
| 2333 | // We can skip it. |
| 2334 | this->skip_call_tls_get_addr_ = true; |
| 2335 | } |
| 2336 | |
| 2337 | // Do a relocation in which we convert a TLS Initial-Exec to a |
| 2338 | // Local-Exec. |
| 2339 | |
| 2340 | inline void |
| 2341 | Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo, |
| 2342 | size_t relnum, |
| 2343 | Output_segment* tls_segment, |
| 2344 | const elfcpp::Rel<32, false>& rel, |
| 2345 | unsigned int r_type, |
| 2346 | elfcpp::Elf_types<32>::Elf_Addr value, |
| 2347 | unsigned char* view, |
| 2348 | section_size_type view_size) |
| 2349 | { |
| 2350 | // We have to actually change the instructions, which means that we |
| 2351 | // need to examine the opcodes to figure out which instruction we |
| 2352 | // are looking at. |
| 2353 | if (r_type == elfcpp::R_386_TLS_IE) |
| 2354 | { |
| 2355 | // movl %gs:XX,%eax ==> movl $YY,%eax |
| 2356 | // movl %gs:XX,%reg ==> movl $YY,%reg |
| 2357 | // addl %gs:XX,%reg ==> addl $YY,%reg |
| 2358 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -1); |
| 2359 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4); |
| 2360 | |
| 2361 | unsigned char op1 = view[-1]; |
| 2362 | if (op1 == 0xa1) |
| 2363 | { |
| 2364 | // movl XX,%eax ==> movl $YY,%eax |
| 2365 | view[-1] = 0xb8; |
| 2366 | } |
| 2367 | else |
| 2368 | { |
| 2369 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2); |
| 2370 | |
| 2371 | unsigned char op2 = view[-2]; |
| 2372 | if (op2 == 0x8b) |
| 2373 | { |
| 2374 | // movl XX,%reg ==> movl $YY,%reg |
| 2375 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
| 2376 | (op1 & 0xc7) == 0x05); |
| 2377 | view[-2] = 0xc7; |
| 2378 | view[-1] = 0xc0 | ((op1 >> 3) & 7); |
| 2379 | } |
| 2380 | else if (op2 == 0x03) |
| 2381 | { |
| 2382 | // addl XX,%reg ==> addl $YY,%reg |
| 2383 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
| 2384 | (op1 & 0xc7) == 0x05); |
| 2385 | view[-2] = 0x81; |
| 2386 | view[-1] = 0xc0 | ((op1 >> 3) & 7); |
| 2387 | } |
| 2388 | else |
| 2389 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0); |
| 2390 | } |
| 2391 | } |
| 2392 | else |
| 2393 | { |
| 2394 | // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2 |
| 2395 | // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2 |
| 2396 | // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2 |
| 2397 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2); |
| 2398 | tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4); |
| 2399 | |
| 2400 | unsigned char op1 = view[-1]; |
| 2401 | unsigned char op2 = view[-2]; |
| 2402 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), |
| 2403 | (op1 & 0xc0) == 0x80 && (op1 & 7) != 4); |
| 2404 | if (op2 == 0x8b) |
| 2405 | { |
| 2406 | // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2 |
| 2407 | view[-2] = 0xc7; |
| 2408 | view[-1] = 0xc0 | ((op1 >> 3) & 7); |
| 2409 | } |
| 2410 | else if (op2 == 0x2b) |
| 2411 | { |
| 2412 | // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2 |
| 2413 | view[-2] = 0x81; |
| 2414 | view[-1] = 0xe8 | ((op1 >> 3) & 7); |
| 2415 | } |
| 2416 | else if (op2 == 0x03) |
| 2417 | { |
| 2418 | // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2 |
| 2419 | view[-2] = 0x81; |
| 2420 | view[-1] = 0xc0 | ((op1 >> 3) & 7); |
| 2421 | } |
| 2422 | else |
| 2423 | tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0); |
| 2424 | } |
| 2425 | |
| 2426 | value = tls_segment->memsz() - value; |
| 2427 | if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE) |
| 2428 | value = - value; |
| 2429 | |
| 2430 | Relocate_functions<32, false>::rel32(view, value); |
| 2431 | } |
| 2432 | |
| 2433 | // Relocate section data. |
| 2434 | |
| 2435 | void |
| 2436 | Target_i386::relocate_section(const Relocate_info<32, false>* relinfo, |
| 2437 | unsigned int sh_type, |
| 2438 | const unsigned char* prelocs, |
| 2439 | size_t reloc_count, |
| 2440 | Output_section* output_section, |
| 2441 | bool needs_special_offset_handling, |
| 2442 | unsigned char* view, |
| 2443 | elfcpp::Elf_types<32>::Elf_Addr address, |
| 2444 | section_size_type view_size) |
| 2445 | { |
| 2446 | gold_assert(sh_type == elfcpp::SHT_REL); |
| 2447 | |
| 2448 | gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL, |
| 2449 | Target_i386::Relocate>( |
| 2450 | relinfo, |
| 2451 | this, |
| 2452 | prelocs, |
| 2453 | reloc_count, |
| 2454 | output_section, |
| 2455 | needs_special_offset_handling, |
| 2456 | view, |
| 2457 | address, |
| 2458 | view_size); |
| 2459 | } |
| 2460 | |
| 2461 | // Return the size of a relocation while scanning during a relocatable |
| 2462 | // link. |
| 2463 | |
| 2464 | unsigned int |
| 2465 | Target_i386::Relocatable_size_for_reloc::get_size_for_reloc( |
| 2466 | unsigned int r_type, |
| 2467 | Relobj* object) |
| 2468 | { |
| 2469 | switch (r_type) |
| 2470 | { |
| 2471 | case elfcpp::R_386_NONE: |
| 2472 | case elfcpp::R_386_GNU_VTINHERIT: |
| 2473 | case elfcpp::R_386_GNU_VTENTRY: |
| 2474 | case elfcpp::R_386_TLS_GD: // Global-dynamic |
| 2475 | case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url) |
| 2476 | case elfcpp::R_386_TLS_DESC_CALL: |
| 2477 | case elfcpp::R_386_TLS_LDM: // Local-dynamic |
| 2478 | case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic |
| 2479 | case elfcpp::R_386_TLS_IE: // Initial-exec |
| 2480 | case elfcpp::R_386_TLS_IE_32: |
| 2481 | case elfcpp::R_386_TLS_GOTIE: |
| 2482 | case elfcpp::R_386_TLS_LE: // Local-exec |
| 2483 | case elfcpp::R_386_TLS_LE_32: |
| 2484 | return 0; |
| 2485 | |
| 2486 | case elfcpp::R_386_32: |
| 2487 | case elfcpp::R_386_PC32: |
| 2488 | case elfcpp::R_386_GOT32: |
| 2489 | case elfcpp::R_386_PLT32: |
| 2490 | case elfcpp::R_386_GOTOFF: |
| 2491 | case elfcpp::R_386_GOTPC: |
| 2492 | return 4; |
| 2493 | |
| 2494 | case elfcpp::R_386_16: |
| 2495 | case elfcpp::R_386_PC16: |
| 2496 | return 2; |
| 2497 | |
| 2498 | case elfcpp::R_386_8: |
| 2499 | case elfcpp::R_386_PC8: |
| 2500 | return 1; |
| 2501 | |
| 2502 | // These are relocations which should only be seen by the |
| 2503 | // dynamic linker, and should never be seen here. |
| 2504 | case elfcpp::R_386_COPY: |
| 2505 | case elfcpp::R_386_GLOB_DAT: |
| 2506 | case elfcpp::R_386_JUMP_SLOT: |
| 2507 | case elfcpp::R_386_RELATIVE: |
| 2508 | case elfcpp::R_386_TLS_TPOFF: |
| 2509 | case elfcpp::R_386_TLS_DTPMOD32: |
| 2510 | case elfcpp::R_386_TLS_DTPOFF32: |
| 2511 | case elfcpp::R_386_TLS_TPOFF32: |
| 2512 | case elfcpp::R_386_TLS_DESC: |
| 2513 | object->error(_("unexpected reloc %u in object file"), r_type); |
| 2514 | return 0; |
| 2515 | |
| 2516 | case elfcpp::R_386_32PLT: |
| 2517 | case elfcpp::R_386_TLS_GD_32: |
| 2518 | case elfcpp::R_386_TLS_GD_PUSH: |
| 2519 | case elfcpp::R_386_TLS_GD_CALL: |
| 2520 | case elfcpp::R_386_TLS_GD_POP: |
| 2521 | case elfcpp::R_386_TLS_LDM_32: |
| 2522 | case elfcpp::R_386_TLS_LDM_PUSH: |
| 2523 | case elfcpp::R_386_TLS_LDM_CALL: |
| 2524 | case elfcpp::R_386_TLS_LDM_POP: |
| 2525 | case elfcpp::R_386_USED_BY_INTEL_200: |
| 2526 | default: |
| 2527 | object->error(_("unsupported reloc %u in object file"), r_type); |
| 2528 | return 0; |
| 2529 | } |
| 2530 | } |
| 2531 | |
| 2532 | // Scan the relocs during a relocatable link. |
| 2533 | |
| 2534 | void |
| 2535 | Target_i386::scan_relocatable_relocs(const General_options& options, |
| 2536 | Symbol_table* symtab, |
| 2537 | Layout* layout, |
| 2538 | Sized_relobj<32, false>* object, |
| 2539 | unsigned int data_shndx, |
| 2540 | unsigned int sh_type, |
| 2541 | const unsigned char* prelocs, |
| 2542 | size_t reloc_count, |
| 2543 | Output_section* output_section, |
| 2544 | bool needs_special_offset_handling, |
| 2545 | size_t local_symbol_count, |
| 2546 | const unsigned char* plocal_symbols, |
| 2547 | Relocatable_relocs* rr) |
| 2548 | { |
| 2549 | gold_assert(sh_type == elfcpp::SHT_REL); |
| 2550 | |
| 2551 | typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_REL, |
| 2552 | Relocatable_size_for_reloc> Scan_relocatable_relocs; |
| 2553 | |
| 2554 | gold::scan_relocatable_relocs<32, false, elfcpp::SHT_REL, |
| 2555 | Scan_relocatable_relocs>( |
| 2556 | options, |
| 2557 | symtab, |
| 2558 | layout, |
| 2559 | object, |
| 2560 | data_shndx, |
| 2561 | prelocs, |
| 2562 | reloc_count, |
| 2563 | output_section, |
| 2564 | needs_special_offset_handling, |
| 2565 | local_symbol_count, |
| 2566 | plocal_symbols, |
| 2567 | rr); |
| 2568 | } |
| 2569 | |
| 2570 | // Relocate a section during a relocatable link. |
| 2571 | |
| 2572 | void |
| 2573 | Target_i386::relocate_for_relocatable( |
| 2574 | const Relocate_info<32, false>* relinfo, |
| 2575 | unsigned int sh_type, |
| 2576 | const unsigned char* prelocs, |
| 2577 | size_t reloc_count, |
| 2578 | Output_section* output_section, |
| 2579 | off_t offset_in_output_section, |
| 2580 | const Relocatable_relocs* rr, |
| 2581 | unsigned char* view, |
| 2582 | elfcpp::Elf_types<32>::Elf_Addr view_address, |
| 2583 | section_size_type view_size, |
| 2584 | unsigned char* reloc_view, |
| 2585 | section_size_type reloc_view_size) |
| 2586 | { |
| 2587 | gold_assert(sh_type == elfcpp::SHT_REL); |
| 2588 | |
| 2589 | gold::relocate_for_relocatable<32, false, elfcpp::SHT_REL>( |
| 2590 | relinfo, |
| 2591 | prelocs, |
| 2592 | reloc_count, |
| 2593 | output_section, |
| 2594 | offset_in_output_section, |
| 2595 | rr, |
| 2596 | view, |
| 2597 | view_address, |
| 2598 | view_size, |
| 2599 | reloc_view, |
| 2600 | reloc_view_size); |
| 2601 | } |
| 2602 | |
| 2603 | // Return the value to use for a dynamic which requires special |
| 2604 | // treatment. This is how we support equality comparisons of function |
| 2605 | // pointers across shared library boundaries, as described in the |
| 2606 | // processor specific ABI supplement. |
| 2607 | |
| 2608 | uint64_t |
| 2609 | Target_i386::do_dynsym_value(const Symbol* gsym) const |
| 2610 | { |
| 2611 | gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset()); |
| 2612 | return this->plt_section()->address() + gsym->plt_offset(); |
| 2613 | } |
| 2614 | |
| 2615 | // Return a string used to fill a code section with nops to take up |
| 2616 | // the specified length. |
| 2617 | |
| 2618 | std::string |
| 2619 | Target_i386::do_code_fill(section_size_type length) const |
| 2620 | { |
| 2621 | if (length >= 16) |
| 2622 | { |
| 2623 | // Build a jmp instruction to skip over the bytes. |
| 2624 | unsigned char jmp[5]; |
| 2625 | jmp[0] = 0xe9; |
| 2626 | elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5); |
| 2627 | return (std::string(reinterpret_cast<char*>(&jmp[0]), 5) |
| 2628 | + std::string(length - 5, '\0')); |
| 2629 | } |
| 2630 | |
| 2631 | // Nop sequences of various lengths. |
| 2632 | const char nop1[1] = { 0x90 }; // nop |
| 2633 | const char nop2[2] = { 0x66, 0x90 }; // xchg %ax %ax |
| 2634 | const char nop3[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi |
| 2635 | const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi |
| 2636 | const char nop5[5] = { 0x90, 0x8d, 0x74, 0x26, // nop |
| 2637 | 0x00 }; // leal 0(%esi,1),%esi |
| 2638 | const char nop6[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi |
| 2639 | 0x00, 0x00 }; |
| 2640 | const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi |
| 2641 | 0x00, 0x00, 0x00 }; |
| 2642 | const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop |
| 2643 | 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi |
| 2644 | const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi |
| 2645 | 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi |
| 2646 | 0x00 }; |
| 2647 | const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi |
| 2648 | 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi |
| 2649 | 0x00, 0x00 }; |
| 2650 | const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi |
| 2651 | 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi |
| 2652 | 0x00, 0x00, 0x00 }; |
| 2653 | const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi |
| 2654 | 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi |
| 2655 | 0x00, 0x00, 0x00, 0x00 }; |
| 2656 | const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi |
| 2657 | 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi |
| 2658 | 0x27, 0x00, 0x00, 0x00, |
| 2659 | 0x00 }; |
| 2660 | const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi |
| 2661 | 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi |
| 2662 | 0xbc, 0x27, 0x00, 0x00, |
| 2663 | 0x00, 0x00 }; |
| 2664 | const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15 |
| 2665 | 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,... |
| 2666 | 0x90, 0x90, 0x90, 0x90, |
| 2667 | 0x90, 0x90, 0x90 }; |
| 2668 | |
| 2669 | const char* nops[16] = { |
| 2670 | NULL, |
| 2671 | nop1, nop2, nop3, nop4, nop5, nop6, nop7, |
| 2672 | nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15 |
| 2673 | }; |
| 2674 | |
| 2675 | return std::string(nops[length], length); |
| 2676 | } |
| 2677 | |
| 2678 | // The selector for i386 object files. |
| 2679 | |
| 2680 | class Target_selector_i386 : public Target_selector_freebsd |
| 2681 | { |
| 2682 | public: |
| 2683 | Target_selector_i386() |
| 2684 | : Target_selector_freebsd(elfcpp::EM_386, 32, false, |
| 2685 | "elf32-i386", "elf32-i386-freebsd") |
| 2686 | { } |
| 2687 | |
| 2688 | Target* |
| 2689 | do_instantiate_target() |
| 2690 | { return new Target_i386(); } |
| 2691 | }; |
| 2692 | |
| 2693 | Target_selector_i386 target_selector_i386; |
| 2694 | |
| 2695 | } // End anonymous namespace. |