| 1 | // reloc.h -- relocate input files for gold -*- C++ -*- |
| 2 | |
| 3 | // Copyright 2006, 2007, 2008, 2009, 2010, 2011, 2012 |
| 4 | // Free Software Foundation, Inc. |
| 5 | // Written by Ian Lance Taylor <iant@google.com>. |
| 6 | |
| 7 | // This file is part of gold. |
| 8 | |
| 9 | // This program is free software; you can redistribute it and/or modify |
| 10 | // it under the terms of the GNU General Public License as published by |
| 11 | // the Free Software Foundation; either version 3 of the License, or |
| 12 | // (at your option) any later version. |
| 13 | |
| 14 | // This program is distributed in the hope that it will be useful, |
| 15 | // but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 17 | // GNU General Public License for more details. |
| 18 | |
| 19 | // You should have received a copy of the GNU General Public License |
| 20 | // along with this program; if not, write to the Free Software |
| 21 | // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
| 22 | // MA 02110-1301, USA. |
| 23 | |
| 24 | #ifndef GOLD_RELOC_H |
| 25 | #define GOLD_RELOC_H |
| 26 | |
| 27 | #include <vector> |
| 28 | #ifdef HAVE_BYTESWAP_H |
| 29 | #include <byteswap.h> |
| 30 | #endif |
| 31 | |
| 32 | #include "elfcpp.h" |
| 33 | #include "workqueue.h" |
| 34 | |
| 35 | namespace gold |
| 36 | { |
| 37 | |
| 38 | class General_options; |
| 39 | class Object; |
| 40 | class Relobj; |
| 41 | struct Read_relocs_data; |
| 42 | class Symbol; |
| 43 | class Layout; |
| 44 | class Output_data; |
| 45 | class Output_section; |
| 46 | |
| 47 | template<int size> |
| 48 | class Sized_symbol; |
| 49 | |
| 50 | template<int size, bool big_endian> |
| 51 | class Sized_relobj_file; |
| 52 | |
| 53 | template<int size> |
| 54 | class Symbol_value; |
| 55 | |
| 56 | template<int sh_type, bool dynamic, int size, bool big_endian> |
| 57 | class Output_data_reloc; |
| 58 | |
| 59 | // A class to read the relocations for an object file, and then queue |
| 60 | // up a task to see if they require any GOT/PLT/COPY relocations in |
| 61 | // the symbol table. |
| 62 | |
| 63 | class Read_relocs : public Task |
| 64 | { |
| 65 | public: |
| 66 | // THIS_BLOCKER and NEXT_BLOCKER are passed along to a Scan_relocs |
| 67 | // or Gc_process_relocs task, so that they run in a deterministic |
| 68 | // order. |
| 69 | Read_relocs(Symbol_table* symtab, Layout* layout, Relobj* object, |
| 70 | Task_token* this_blocker, Task_token* next_blocker) |
| 71 | : symtab_(symtab), layout_(layout), object_(object), |
| 72 | this_blocker_(this_blocker), next_blocker_(next_blocker) |
| 73 | { } |
| 74 | |
| 75 | // The standard Task methods. |
| 76 | |
| 77 | Task_token* |
| 78 | is_runnable(); |
| 79 | |
| 80 | void |
| 81 | locks(Task_locker*); |
| 82 | |
| 83 | void |
| 84 | run(Workqueue*); |
| 85 | |
| 86 | std::string |
| 87 | get_name() const; |
| 88 | |
| 89 | private: |
| 90 | Symbol_table* symtab_; |
| 91 | Layout* layout_; |
| 92 | Relobj* object_; |
| 93 | Task_token* this_blocker_; |
| 94 | Task_token* next_blocker_; |
| 95 | }; |
| 96 | |
| 97 | // Process the relocs to figure out which sections are garbage. |
| 98 | // Very similar to scan relocs. |
| 99 | |
| 100 | class Gc_process_relocs : public Task |
| 101 | { |
| 102 | public: |
| 103 | // THIS_BLOCKER prevents this task from running until the previous |
| 104 | // one is finished. NEXT_BLOCKER prevents the next task from |
| 105 | // running. |
| 106 | Gc_process_relocs(Symbol_table* symtab, Layout* layout, Relobj* object, |
| 107 | Read_relocs_data* rd, Task_token* this_blocker, |
| 108 | Task_token* next_blocker) |
| 109 | : symtab_(symtab), layout_(layout), object_(object), rd_(rd), |
| 110 | this_blocker_(this_blocker), next_blocker_(next_blocker) |
| 111 | { } |
| 112 | |
| 113 | ~Gc_process_relocs(); |
| 114 | |
| 115 | // The standard Task methods. |
| 116 | |
| 117 | Task_token* |
| 118 | is_runnable(); |
| 119 | |
| 120 | void |
| 121 | locks(Task_locker*); |
| 122 | |
| 123 | void |
| 124 | run(Workqueue*); |
| 125 | |
| 126 | std::string |
| 127 | get_name() const; |
| 128 | |
| 129 | private: |
| 130 | Symbol_table* symtab_; |
| 131 | Layout* layout_; |
| 132 | Relobj* object_; |
| 133 | Read_relocs_data* rd_; |
| 134 | Task_token* this_blocker_; |
| 135 | Task_token* next_blocker_; |
| 136 | }; |
| 137 | |
| 138 | // Scan the relocations for an object to see if they require any |
| 139 | // GOT/PLT/COPY relocations. |
| 140 | |
| 141 | class Scan_relocs : public Task |
| 142 | { |
| 143 | public: |
| 144 | // THIS_BLOCKER prevents this task from running until the previous |
| 145 | // one is finished. NEXT_BLOCKER prevents the next task from |
| 146 | // running. |
| 147 | Scan_relocs(Symbol_table* symtab, Layout* layout, Relobj* object, |
| 148 | Read_relocs_data* rd, Task_token* this_blocker, |
| 149 | Task_token* next_blocker) |
| 150 | : symtab_(symtab), layout_(layout), object_(object), rd_(rd), |
| 151 | this_blocker_(this_blocker), next_blocker_(next_blocker) |
| 152 | { } |
| 153 | |
| 154 | ~Scan_relocs(); |
| 155 | |
| 156 | // The standard Task methods. |
| 157 | |
| 158 | Task_token* |
| 159 | is_runnable(); |
| 160 | |
| 161 | void |
| 162 | locks(Task_locker*); |
| 163 | |
| 164 | void |
| 165 | run(Workqueue*); |
| 166 | |
| 167 | std::string |
| 168 | get_name() const; |
| 169 | |
| 170 | private: |
| 171 | Symbol_table* symtab_; |
| 172 | Layout* layout_; |
| 173 | Relobj* object_; |
| 174 | Read_relocs_data* rd_; |
| 175 | Task_token* this_blocker_; |
| 176 | Task_token* next_blocker_; |
| 177 | }; |
| 178 | |
| 179 | // A class to perform all the relocations for an object file. |
| 180 | |
| 181 | class Relocate_task : public Task |
| 182 | { |
| 183 | public: |
| 184 | Relocate_task(const Symbol_table* symtab, const Layout* layout, |
| 185 | Relobj* object, Output_file* of, |
| 186 | Task_token* input_sections_blocker, |
| 187 | Task_token* output_sections_blocker, Task_token* final_blocker) |
| 188 | : symtab_(symtab), layout_(layout), object_(object), of_(of), |
| 189 | input_sections_blocker_(input_sections_blocker), |
| 190 | output_sections_blocker_(output_sections_blocker), |
| 191 | final_blocker_(final_blocker) |
| 192 | { } |
| 193 | |
| 194 | // The standard Task methods. |
| 195 | |
| 196 | Task_token* |
| 197 | is_runnable(); |
| 198 | |
| 199 | void |
| 200 | locks(Task_locker*); |
| 201 | |
| 202 | void |
| 203 | run(Workqueue*); |
| 204 | |
| 205 | std::string |
| 206 | get_name() const; |
| 207 | |
| 208 | private: |
| 209 | const Symbol_table* symtab_; |
| 210 | const Layout* layout_; |
| 211 | Relobj* object_; |
| 212 | Output_file* of_; |
| 213 | Task_token* input_sections_blocker_; |
| 214 | Task_token* output_sections_blocker_; |
| 215 | Task_token* final_blocker_; |
| 216 | }; |
| 217 | |
| 218 | // During a relocatable link, this class records how relocations |
| 219 | // should be handled for a single input reloc section. An instance of |
| 220 | // this class is created while scanning relocs, and it is used while |
| 221 | // processing relocs. |
| 222 | |
| 223 | class Relocatable_relocs |
| 224 | { |
| 225 | public: |
| 226 | // We use a vector of unsigned char to indicate how the input relocs |
| 227 | // should be handled. Each element is one of the following values. |
| 228 | // We create this vector when we initially scan the relocations. |
| 229 | enum Reloc_strategy |
| 230 | { |
| 231 | // Copy the input reloc. Don't modify it other than updating the |
| 232 | // r_offset field and the r_sym part of the r_info field. |
| 233 | RELOC_COPY, |
| 234 | // Copy the input reloc which is against an STT_SECTION symbol. |
| 235 | // Update the r_offset and r_sym part of the r_info field. Adjust |
| 236 | // the addend by subtracting the value of the old local symbol and |
| 237 | // adding the value of the new local symbol. The addend is in the |
| 238 | // SHT_RELA reloc and the contents of the data section do not need |
| 239 | // to be changed. |
| 240 | RELOC_ADJUST_FOR_SECTION_RELA, |
| 241 | // Like RELOC_ADJUST_FOR_SECTION_RELA but the addend should not be |
| 242 | // adjusted. |
| 243 | RELOC_ADJUST_FOR_SECTION_0, |
| 244 | // Like RELOC_ADJUST_FOR_SECTION_RELA but the contents of the |
| 245 | // section need to be changed. The number indicates the number of |
| 246 | // bytes in the addend in the section contents. |
| 247 | RELOC_ADJUST_FOR_SECTION_1, |
| 248 | RELOC_ADJUST_FOR_SECTION_2, |
| 249 | RELOC_ADJUST_FOR_SECTION_4, |
| 250 | RELOC_ADJUST_FOR_SECTION_8, |
| 251 | // Like RELOC_ADJUST_FOR_SECTION_4 but for unaligned relocs. |
| 252 | RELOC_ADJUST_FOR_SECTION_4_UNALIGNED, |
| 253 | // Discard the input reloc--process it completely when relocating |
| 254 | // the data section contents. |
| 255 | RELOC_DISCARD, |
| 256 | // An input reloc which is not discarded, but which requires |
| 257 | // target specific processing in order to update it. |
| 258 | RELOC_SPECIAL |
| 259 | }; |
| 260 | |
| 261 | Relocatable_relocs() |
| 262 | : reloc_strategies_(), output_reloc_count_(0), posd_(NULL) |
| 263 | { } |
| 264 | |
| 265 | // Record the number of relocs. |
| 266 | void |
| 267 | set_reloc_count(size_t reloc_count) |
| 268 | { this->reloc_strategies_.reserve(reloc_count); } |
| 269 | |
| 270 | // Record what to do for the next reloc. |
| 271 | void |
| 272 | set_next_reloc_strategy(Reloc_strategy strategy) |
| 273 | { |
| 274 | this->reloc_strategies_.push_back(static_cast<unsigned char>(strategy)); |
| 275 | if (strategy != RELOC_DISCARD) |
| 276 | ++this->output_reloc_count_; |
| 277 | } |
| 278 | |
| 279 | // Record the Output_data associated with this reloc section. |
| 280 | void |
| 281 | set_output_data(Output_data* posd) |
| 282 | { |
| 283 | gold_assert(this->posd_ == NULL); |
| 284 | this->posd_ = posd; |
| 285 | } |
| 286 | |
| 287 | // Return the Output_data associated with this reloc section. |
| 288 | Output_data* |
| 289 | output_data() const |
| 290 | { return this->posd_; } |
| 291 | |
| 292 | // Return what to do for reloc I. |
| 293 | Reloc_strategy |
| 294 | strategy(unsigned int i) const |
| 295 | { |
| 296 | gold_assert(i < this->reloc_strategies_.size()); |
| 297 | return static_cast<Reloc_strategy>(this->reloc_strategies_[i]); |
| 298 | } |
| 299 | |
| 300 | // Return the number of relocations to create in the output file. |
| 301 | size_t |
| 302 | output_reloc_count() const |
| 303 | { return this->output_reloc_count_; } |
| 304 | |
| 305 | private: |
| 306 | typedef std::vector<unsigned char> Reloc_strategies; |
| 307 | |
| 308 | // The strategies for the input reloc. There is one entry in this |
| 309 | // vector for each relocation in the input section. |
| 310 | Reloc_strategies reloc_strategies_; |
| 311 | // The number of relocations to be created in the output file. |
| 312 | size_t output_reloc_count_; |
| 313 | // The output data structure associated with this relocation. |
| 314 | Output_data* posd_; |
| 315 | }; |
| 316 | |
| 317 | // Standard relocation routines which are used on many targets. Here |
| 318 | // SIZE and BIG_ENDIAN refer to the target, not the relocation type. |
| 319 | |
| 320 | template<int size, bool big_endian> |
| 321 | class Relocate_functions |
| 322 | { |
| 323 | private: |
| 324 | // Do a simple relocation with the addend in the section contents. |
| 325 | // VALSIZE is the size of the value. |
| 326 | template<int valsize> |
| 327 | static inline void |
| 328 | rel(unsigned char* view, |
| 329 | typename elfcpp::Swap<valsize, big_endian>::Valtype value) |
| 330 | { |
| 331 | typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype; |
| 332 | Valtype* wv = reinterpret_cast<Valtype*>(view); |
| 333 | Valtype x = elfcpp::Swap<valsize, big_endian>::readval(wv); |
| 334 | elfcpp::Swap<valsize, big_endian>::writeval(wv, x + value); |
| 335 | } |
| 336 | |
| 337 | // Like the above but for relocs at unaligned addresses. |
| 338 | template<int valsize> |
| 339 | static inline void |
| 340 | rel_unaligned(unsigned char* view, |
| 341 | typename elfcpp::Swap<valsize, big_endian>::Valtype value) |
| 342 | { |
| 343 | typedef typename elfcpp::Swap_unaligned<valsize, big_endian>::Valtype |
| 344 | Valtype; |
| 345 | Valtype x = elfcpp::Swap_unaligned<valsize, big_endian>::readval(view); |
| 346 | elfcpp::Swap_unaligned<valsize, big_endian>::writeval(view, x + value); |
| 347 | } |
| 348 | |
| 349 | // Do a simple relocation using a Symbol_value with the addend in |
| 350 | // the section contents. VALSIZE is the size of the value to |
| 351 | // relocate. |
| 352 | template<int valsize> |
| 353 | static inline void |
| 354 | rel(unsigned char* view, |
| 355 | const Sized_relobj_file<size, big_endian>* object, |
| 356 | const Symbol_value<size>* psymval) |
| 357 | { |
| 358 | typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype; |
| 359 | Valtype* wv = reinterpret_cast<Valtype*>(view); |
| 360 | Valtype x = elfcpp::Swap<valsize, big_endian>::readval(wv); |
| 361 | x = psymval->value(object, x); |
| 362 | elfcpp::Swap<valsize, big_endian>::writeval(wv, x); |
| 363 | } |
| 364 | |
| 365 | // Like the above but for relocs at unaligned addresses. |
| 366 | template<int valsize> |
| 367 | static inline void |
| 368 | rel_unaligned(unsigned char* view, |
| 369 | const Sized_relobj_file<size, big_endian>* object, |
| 370 | const Symbol_value<size>* psymval) |
| 371 | { |
| 372 | typedef typename elfcpp::Swap_unaligned<valsize, big_endian>::Valtype |
| 373 | Valtype; |
| 374 | Valtype x = elfcpp::Swap_unaligned<valsize, big_endian>::readval(view); |
| 375 | x = psymval->value(object, x); |
| 376 | elfcpp::Swap_unaligned<valsize, big_endian>::writeval(view, x); |
| 377 | } |
| 378 | |
| 379 | // Do a simple relocation with the addend in the relocation. |
| 380 | // VALSIZE is the size of the value. |
| 381 | template<int valsize> |
| 382 | static inline void |
| 383 | rela(unsigned char* view, |
| 384 | typename elfcpp::Swap<valsize, big_endian>::Valtype value, |
| 385 | typename elfcpp::Swap<valsize, big_endian>::Valtype addend) |
| 386 | { |
| 387 | typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype; |
| 388 | Valtype* wv = reinterpret_cast<Valtype*>(view); |
| 389 | elfcpp::Swap<valsize, big_endian>::writeval(wv, value + addend); |
| 390 | } |
| 391 | |
| 392 | // Do a simple relocation using a symbol value with the addend in |
| 393 | // the relocation. VALSIZE is the size of the value. |
| 394 | template<int valsize> |
| 395 | static inline void |
| 396 | rela(unsigned char* view, |
| 397 | const Sized_relobj_file<size, big_endian>* object, |
| 398 | const Symbol_value<size>* psymval, |
| 399 | typename elfcpp::Swap<valsize, big_endian>::Valtype addend) |
| 400 | { |
| 401 | typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype; |
| 402 | Valtype* wv = reinterpret_cast<Valtype*>(view); |
| 403 | Valtype x = psymval->value(object, addend); |
| 404 | elfcpp::Swap<valsize, big_endian>::writeval(wv, x); |
| 405 | } |
| 406 | |
| 407 | // Do a simple PC relative relocation with the addend in the section |
| 408 | // contents. VALSIZE is the size of the value. |
| 409 | template<int valsize> |
| 410 | static inline void |
| 411 | pcrel(unsigned char* view, |
| 412 | typename elfcpp::Swap<valsize, big_endian>::Valtype value, |
| 413 | typename elfcpp::Elf_types<size>::Elf_Addr address) |
| 414 | { |
| 415 | typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype; |
| 416 | Valtype* wv = reinterpret_cast<Valtype*>(view); |
| 417 | Valtype x = elfcpp::Swap<valsize, big_endian>::readval(wv); |
| 418 | elfcpp::Swap<valsize, big_endian>::writeval(wv, x + value - address); |
| 419 | } |
| 420 | |
| 421 | // Like the above but for relocs at unaligned addresses. |
| 422 | template<int valsize> |
| 423 | static inline void |
| 424 | pcrel_unaligned(unsigned char* view, |
| 425 | typename elfcpp::Swap<valsize, big_endian>::Valtype value, |
| 426 | typename elfcpp::Elf_types<size>::Elf_Addr address) |
| 427 | { |
| 428 | typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype; |
| 429 | Valtype x = elfcpp::Swap_unaligned<valsize, big_endian>::readval(view); |
| 430 | elfcpp::Swap_unaligned<valsize, big_endian>::writeval(view, |
| 431 | x + value - address); |
| 432 | } |
| 433 | |
| 434 | // Do a simple PC relative relocation with a Symbol_value with the |
| 435 | // addend in the section contents. VALSIZE is the size of the |
| 436 | // value. |
| 437 | template<int valsize> |
| 438 | static inline void |
| 439 | pcrel(unsigned char* view, |
| 440 | const Sized_relobj_file<size, big_endian>* object, |
| 441 | const Symbol_value<size>* psymval, |
| 442 | typename elfcpp::Elf_types<size>::Elf_Addr address) |
| 443 | { |
| 444 | typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype; |
| 445 | Valtype* wv = reinterpret_cast<Valtype*>(view); |
| 446 | Valtype x = elfcpp::Swap<valsize, big_endian>::readval(wv); |
| 447 | x = psymval->value(object, x); |
| 448 | elfcpp::Swap<valsize, big_endian>::writeval(wv, x - address); |
| 449 | } |
| 450 | |
| 451 | // Do a simple PC relative relocation with the addend in the |
| 452 | // relocation. VALSIZE is the size of the value. |
| 453 | template<int valsize> |
| 454 | static inline void |
| 455 | pcrela(unsigned char* view, |
| 456 | typename elfcpp::Swap<valsize, big_endian>::Valtype value, |
| 457 | typename elfcpp::Swap<valsize, big_endian>::Valtype addend, |
| 458 | typename elfcpp::Elf_types<size>::Elf_Addr address) |
| 459 | { |
| 460 | typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype; |
| 461 | Valtype* wv = reinterpret_cast<Valtype*>(view); |
| 462 | elfcpp::Swap<valsize, big_endian>::writeval(wv, value + addend - address); |
| 463 | } |
| 464 | |
| 465 | // Do a simple PC relative relocation with a Symbol_value with the |
| 466 | // addend in the relocation. VALSIZE is the size of the value. |
| 467 | template<int valsize> |
| 468 | static inline void |
| 469 | pcrela(unsigned char* view, |
| 470 | const Sized_relobj_file<size, big_endian>* object, |
| 471 | const Symbol_value<size>* psymval, |
| 472 | typename elfcpp::Swap<valsize, big_endian>::Valtype addend, |
| 473 | typename elfcpp::Elf_types<size>::Elf_Addr address) |
| 474 | { |
| 475 | typedef typename elfcpp::Swap<valsize, big_endian>::Valtype Valtype; |
| 476 | Valtype* wv = reinterpret_cast<Valtype*>(view); |
| 477 | Valtype x = psymval->value(object, addend); |
| 478 | elfcpp::Swap<valsize, big_endian>::writeval(wv, x - address); |
| 479 | } |
| 480 | |
| 481 | typedef Relocate_functions<size, big_endian> This; |
| 482 | |
| 483 | public: |
| 484 | // Do a simple 8-bit REL relocation with the addend in the section |
| 485 | // contents. |
| 486 | static inline void |
| 487 | rel8(unsigned char* view, unsigned char value) |
| 488 | { This::template rel<8>(view, value); } |
| 489 | |
| 490 | static inline void |
| 491 | rel8(unsigned char* view, |
| 492 | const Sized_relobj_file<size, big_endian>* object, |
| 493 | const Symbol_value<size>* psymval) |
| 494 | { This::template rel<8>(view, object, psymval); } |
| 495 | |
| 496 | // Do an 8-bit RELA relocation with the addend in the relocation. |
| 497 | static inline void |
| 498 | rela8(unsigned char* view, unsigned char value, unsigned char addend) |
| 499 | { This::template rela<8>(view, value, addend); } |
| 500 | |
| 501 | static inline void |
| 502 | rela8(unsigned char* view, |
| 503 | const Sized_relobj_file<size, big_endian>* object, |
| 504 | const Symbol_value<size>* psymval, |
| 505 | unsigned char addend) |
| 506 | { This::template rela<8>(view, object, psymval, addend); } |
| 507 | |
| 508 | // Do a simple 8-bit PC relative relocation with the addend in the |
| 509 | // section contents. |
| 510 | static inline void |
| 511 | pcrel8(unsigned char* view, unsigned char value, |
| 512 | typename elfcpp::Elf_types<size>::Elf_Addr address) |
| 513 | { This::template pcrel<8>(view, value, address); } |
| 514 | |
| 515 | static inline void |
| 516 | pcrel8(unsigned char* view, |
| 517 | const Sized_relobj_file<size, big_endian>* object, |
| 518 | const Symbol_value<size>* psymval, |
| 519 | typename elfcpp::Elf_types<size>::Elf_Addr address) |
| 520 | { This::template pcrel<8>(view, object, psymval, address); } |
| 521 | |
| 522 | // Do a simple 8-bit PC relative RELA relocation with the addend in |
| 523 | // the reloc. |
| 524 | static inline void |
| 525 | pcrela8(unsigned char* view, unsigned char value, unsigned char addend, |
| 526 | typename elfcpp::Elf_types<size>::Elf_Addr address) |
| 527 | { This::template pcrela<8>(view, value, addend, address); } |
| 528 | |
| 529 | static inline void |
| 530 | pcrela8(unsigned char* view, |
| 531 | const Sized_relobj_file<size, big_endian>* object, |
| 532 | const Symbol_value<size>* psymval, |
| 533 | unsigned char addend, |
| 534 | typename elfcpp::Elf_types<size>::Elf_Addr address) |
| 535 | { This::template pcrela<8>(view, object, psymval, addend, address); } |
| 536 | |
| 537 | // Do a simple 16-bit REL relocation with the addend in the section |
| 538 | // contents. |
| 539 | static inline void |
| 540 | rel16(unsigned char* view, elfcpp::Elf_Half value) |
| 541 | { This::template rel<16>(view, value); } |
| 542 | |
| 543 | static inline void |
| 544 | rel16(unsigned char* view, |
| 545 | const Sized_relobj_file<size, big_endian>* object, |
| 546 | const Symbol_value<size>* psymval) |
| 547 | { This::template rel<16>(view, object, psymval); } |
| 548 | |
| 549 | // Do an 16-bit RELA relocation with the addend in the relocation. |
| 550 | static inline void |
| 551 | rela16(unsigned char* view, elfcpp::Elf_Half value, elfcpp::Elf_Half addend) |
| 552 | { This::template rela<16>(view, value, addend); } |
| 553 | |
| 554 | static inline void |
| 555 | rela16(unsigned char* view, |
| 556 | const Sized_relobj_file<size, big_endian>* object, |
| 557 | const Symbol_value<size>* psymval, |
| 558 | elfcpp::Elf_Half addend) |
| 559 | { This::template rela<16>(view, object, psymval, addend); } |
| 560 | |
| 561 | // Do a simple 16-bit PC relative REL relocation with the addend in |
| 562 | // the section contents. |
| 563 | static inline void |
| 564 | pcrel16(unsigned char* view, elfcpp::Elf_Half value, |
| 565 | typename elfcpp::Elf_types<size>::Elf_Addr address) |
| 566 | { This::template pcrel<16>(view, value, address); } |
| 567 | |
| 568 | static inline void |
| 569 | pcrel16(unsigned char* view, |
| 570 | const Sized_relobj_file<size, big_endian>* object, |
| 571 | const Symbol_value<size>* psymval, |
| 572 | typename elfcpp::Elf_types<size>::Elf_Addr address) |
| 573 | { This::template pcrel<16>(view, object, psymval, address); } |
| 574 | |
| 575 | // Do a simple 16-bit PC relative RELA relocation with the addend in |
| 576 | // the reloc. |
| 577 | static inline void |
| 578 | pcrela16(unsigned char* view, elfcpp::Elf_Half value, |
| 579 | elfcpp::Elf_Half addend, |
| 580 | typename elfcpp::Elf_types<size>::Elf_Addr address) |
| 581 | { This::template pcrela<16>(view, value, addend, address); } |
| 582 | |
| 583 | static inline void |
| 584 | pcrela16(unsigned char* view, |
| 585 | const Sized_relobj_file<size, big_endian>* object, |
| 586 | const Symbol_value<size>* psymval, |
| 587 | elfcpp::Elf_Half addend, |
| 588 | typename elfcpp::Elf_types<size>::Elf_Addr address) |
| 589 | { This::template pcrela<16>(view, object, psymval, addend, address); } |
| 590 | |
| 591 | // Do a simple 32-bit REL relocation with the addend in the section |
| 592 | // contents. |
| 593 | static inline void |
| 594 | rel32(unsigned char* view, elfcpp::Elf_Word value) |
| 595 | { This::template rel<32>(view, value); } |
| 596 | |
| 597 | // Like above but for relocs at unaligned addresses. |
| 598 | static inline void |
| 599 | rel32_unaligned(unsigned char* view, elfcpp::Elf_Word value) |
| 600 | { This::template rel_unaligned<32>(view, value); } |
| 601 | |
| 602 | static inline void |
| 603 | rel32(unsigned char* view, |
| 604 | const Sized_relobj_file<size, big_endian>* object, |
| 605 | const Symbol_value<size>* psymval) |
| 606 | { This::template rel<32>(view, object, psymval); } |
| 607 | |
| 608 | // Like above but for relocs at unaligned addresses. |
| 609 | static inline void |
| 610 | rel32_unaligned(unsigned char* view, |
| 611 | const Sized_relobj_file<size, big_endian>* object, |
| 612 | const Symbol_value<size>* psymval) |
| 613 | { This::template rel_unaligned<32>(view, object, psymval); } |
| 614 | |
| 615 | // Do an 32-bit RELA relocation with the addend in the relocation. |
| 616 | static inline void |
| 617 | rela32(unsigned char* view, elfcpp::Elf_Word value, elfcpp::Elf_Word addend) |
| 618 | { This::template rela<32>(view, value, addend); } |
| 619 | |
| 620 | static inline void |
| 621 | rela32(unsigned char* view, |
| 622 | const Sized_relobj_file<size, big_endian>* object, |
| 623 | const Symbol_value<size>* psymval, |
| 624 | elfcpp::Elf_Word addend) |
| 625 | { This::template rela<32>(view, object, psymval, addend); } |
| 626 | |
| 627 | // Do a simple 32-bit PC relative REL relocation with the addend in |
| 628 | // the section contents. |
| 629 | static inline void |
| 630 | pcrel32(unsigned char* view, elfcpp::Elf_Word value, |
| 631 | typename elfcpp::Elf_types<size>::Elf_Addr address) |
| 632 | { This::template pcrel<32>(view, value, address); } |
| 633 | |
| 634 | // Unaligned version of the above. |
| 635 | static inline void |
| 636 | pcrel32_unaligned(unsigned char* view, elfcpp::Elf_Word value, |
| 637 | typename elfcpp::Elf_types<size>::Elf_Addr address) |
| 638 | { This::template pcrel_unaligned<32>(view, value, address); } |
| 639 | |
| 640 | static inline void |
| 641 | pcrel32(unsigned char* view, |
| 642 | const Sized_relobj_file<size, big_endian>* object, |
| 643 | const Symbol_value<size>* psymval, |
| 644 | typename elfcpp::Elf_types<size>::Elf_Addr address) |
| 645 | { This::template pcrel<32>(view, object, psymval, address); } |
| 646 | |
| 647 | // Do a simple 32-bit PC relative RELA relocation with the addend in |
| 648 | // the relocation. |
| 649 | static inline void |
| 650 | pcrela32(unsigned char* view, elfcpp::Elf_Word value, |
| 651 | elfcpp::Elf_Word addend, |
| 652 | typename elfcpp::Elf_types<size>::Elf_Addr address) |
| 653 | { This::template pcrela<32>(view, value, addend, address); } |
| 654 | |
| 655 | static inline void |
| 656 | pcrela32(unsigned char* view, |
| 657 | const Sized_relobj_file<size, big_endian>* object, |
| 658 | const Symbol_value<size>* psymval, |
| 659 | elfcpp::Elf_Word addend, |
| 660 | typename elfcpp::Elf_types<size>::Elf_Addr address) |
| 661 | { This::template pcrela<32>(view, object, psymval, addend, address); } |
| 662 | |
| 663 | // Do a simple 64-bit REL relocation with the addend in the section |
| 664 | // contents. |
| 665 | static inline void |
| 666 | rel64(unsigned char* view, elfcpp::Elf_Xword value) |
| 667 | { This::template rel<64>(view, value); } |
| 668 | |
| 669 | static inline void |
| 670 | rel64(unsigned char* view, |
| 671 | const Sized_relobj_file<size, big_endian>* object, |
| 672 | const Symbol_value<size>* psymval) |
| 673 | { This::template rel<64>(view, object, psymval); } |
| 674 | |
| 675 | // Do a 64-bit RELA relocation with the addend in the relocation. |
| 676 | static inline void |
| 677 | rela64(unsigned char* view, elfcpp::Elf_Xword value, |
| 678 | elfcpp::Elf_Xword addend) |
| 679 | { This::template rela<64>(view, value, addend); } |
| 680 | |
| 681 | static inline void |
| 682 | rela64(unsigned char* view, |
| 683 | const Sized_relobj_file<size, big_endian>* object, |
| 684 | const Symbol_value<size>* psymval, |
| 685 | elfcpp::Elf_Xword addend) |
| 686 | { This::template rela<64>(view, object, psymval, addend); } |
| 687 | |
| 688 | // Do a simple 64-bit PC relative REL relocation with the addend in |
| 689 | // the section contents. |
| 690 | static inline void |
| 691 | pcrel64(unsigned char* view, elfcpp::Elf_Xword value, |
| 692 | typename elfcpp::Elf_types<size>::Elf_Addr address) |
| 693 | { This::template pcrel<64>(view, value, address); } |
| 694 | |
| 695 | static inline void |
| 696 | pcrel64(unsigned char* view, |
| 697 | const Sized_relobj_file<size, big_endian>* object, |
| 698 | const Symbol_value<size>* psymval, |
| 699 | typename elfcpp::Elf_types<size>::Elf_Addr address) |
| 700 | { This::template pcrel<64>(view, object, psymval, address); } |
| 701 | |
| 702 | // Do a simple 64-bit PC relative RELA relocation with the addend in |
| 703 | // the relocation. |
| 704 | static inline void |
| 705 | pcrela64(unsigned char* view, elfcpp::Elf_Xword value, |
| 706 | elfcpp::Elf_Xword addend, |
| 707 | typename elfcpp::Elf_types<size>::Elf_Addr address) |
| 708 | { This::template pcrela<64>(view, value, addend, address); } |
| 709 | |
| 710 | static inline void |
| 711 | pcrela64(unsigned char* view, |
| 712 | const Sized_relobj_file<size, big_endian>* object, |
| 713 | const Symbol_value<size>* psymval, |
| 714 | elfcpp::Elf_Xword addend, |
| 715 | typename elfcpp::Elf_types<size>::Elf_Addr address) |
| 716 | { This::template pcrela<64>(view, object, psymval, addend, address); } |
| 717 | }; |
| 718 | |
| 719 | // Integer manipulation functions used by various targets when |
| 720 | // performing relocations. |
| 721 | |
| 722 | template<int bits> |
| 723 | class Bits |
| 724 | { |
| 725 | public: |
| 726 | // Sign extend an n-bit unsigned integer stored in a uint32_t into |
| 727 | // an int32_t. BITS must be between 1 and 32. |
| 728 | static inline int32_t |
| 729 | sign_extend32(uint32_t val) |
| 730 | { |
| 731 | gold_assert(bits > 0 && bits <= 32); |
| 732 | if (bits == 32) |
| 733 | return static_cast<int32_t>(val); |
| 734 | uint32_t mask = (~static_cast<uint32_t>(0)) >> (32 - bits); |
| 735 | val &= mask; |
| 736 | uint32_t top_bit = 1U << (bits - 1); |
| 737 | int32_t as_signed = static_cast<int32_t>(val); |
| 738 | if ((val & top_bit) != 0) |
| 739 | as_signed -= static_cast<int32_t>(top_bit * 2); |
| 740 | return as_signed; |
| 741 | } |
| 742 | |
| 743 | // Return true if VAL (stored in a uint32_t) has overflowed a signed |
| 744 | // value with BITS bits. |
| 745 | static inline bool |
| 746 | has_overflow32(uint32_t val) |
| 747 | { |
| 748 | gold_assert(bits > 0 && bits <= 32); |
| 749 | if (bits == 32) |
| 750 | return false; |
| 751 | int32_t max = (1 << (bits - 1)) - 1; |
| 752 | int32_t min = -(1 << (bits - 1)); |
| 753 | int32_t as_signed = static_cast<int32_t>(val); |
| 754 | return as_signed > max || as_signed < min; |
| 755 | } |
| 756 | |
| 757 | // Return true if VAL (stored in a uint32_t) has overflowed both a |
| 758 | // signed and an unsigned value. E.g., |
| 759 | // Bits<8>::has_signed_unsigned_overflow32 would check -128 <= VAL < |
| 760 | // 255. |
| 761 | static inline bool |
| 762 | has_signed_unsigned_overflow32(uint32_t val) |
| 763 | { |
| 764 | gold_assert(bits > 0 && bits <= 32); |
| 765 | if (bits == 32) |
| 766 | return false; |
| 767 | int32_t max = static_cast<int32_t>((1U << bits) - 1); |
| 768 | int32_t min = -(1 << (bits - 1)); |
| 769 | int32_t as_signed = static_cast<int32_t>(val); |
| 770 | return as_signed > max || as_signed < min; |
| 771 | } |
| 772 | |
| 773 | // Select bits from A and B using bits in MASK. For each n in |
| 774 | // [0..31], the n-th bit in the result is chosen from the n-th bits |
| 775 | // of A and B. A zero selects A and a one selects B. |
| 776 | static inline uint32_t |
| 777 | bit_select32(uint32_t a, uint32_t b, uint32_t mask) |
| 778 | { return (a & ~mask) | (b & mask); } |
| 779 | |
| 780 | // Sign extend an n-bit unsigned integer stored in a uint64_t into |
| 781 | // an int64_t. BITS must be between 1 and 64. |
| 782 | static inline int64_t |
| 783 | sign_extend(uint64_t val) |
| 784 | { |
| 785 | gold_assert(bits > 0 && bits <= 64); |
| 786 | if (bits == 64) |
| 787 | return static_cast<int64_t>(val); |
| 788 | uint64_t mask = (~static_cast<uint64_t>(0)) >> (64 - bits); |
| 789 | val &= mask; |
| 790 | uint64_t top_bit = static_cast<uint64_t>(1) << (bits - 1); |
| 791 | int64_t as_signed = static_cast<int64_t>(val); |
| 792 | if ((val & top_bit) != 0) |
| 793 | as_signed -= static_cast<int64_t>(top_bit * 2); |
| 794 | return as_signed; |
| 795 | } |
| 796 | |
| 797 | // Return true if VAL (stored in a uint64_t) has overflowed a signed |
| 798 | // value with BITS bits. |
| 799 | static inline bool |
| 800 | has_overflow(uint64_t val) |
| 801 | { |
| 802 | gold_assert(bits > 0 && bits <= 64); |
| 803 | if (bits == 64) |
| 804 | return false; |
| 805 | int64_t max = (static_cast<int64_t>(1) << (bits - 1)) - 1; |
| 806 | int64_t min = -(static_cast<int64_t>(1) << (bits - 1)); |
| 807 | int64_t as_signed = static_cast<int64_t>(val); |
| 808 | return as_signed > max || as_signed < min; |
| 809 | } |
| 810 | |
| 811 | // Return true if VAL (stored in a uint64_t) has overflowed both a |
| 812 | // signed and an unsigned value. E.g., |
| 813 | // Bits<8>::has_signed_unsigned_overflow would check -128 <= VAL < |
| 814 | // 255. |
| 815 | static inline bool |
| 816 | has_signed_unsigned_overflow64(uint64_t val) |
| 817 | { |
| 818 | gold_assert(bits > 0 && bits <= 64); |
| 819 | if (bits == 64) |
| 820 | return false; |
| 821 | int64_t max = static_cast<int64_t>((static_cast<uint64_t>(1) << bits) - 1); |
| 822 | int64_t min = -(static_cast<int64_t>(1) << (bits - 1)); |
| 823 | int64_t as_signed = static_cast<int64_t>(val); |
| 824 | return as_signed > max || as_signed < min; |
| 825 | } |
| 826 | |
| 827 | // Select bits from A and B using bits in MASK. For each n in |
| 828 | // [0..31], the n-th bit in the result is chosen from the n-th bits |
| 829 | // of A and B. A zero selects A and a one selects B. |
| 830 | static inline uint64_t |
| 831 | bit_select64(uint64_t a, uint64_t b, uint64_t mask) |
| 832 | { return (a & ~mask) | (b & mask); } |
| 833 | }; |
| 834 | |
| 835 | // Track relocations while reading a section. This lets you ask for |
| 836 | // the relocation at a certain offset, and see how relocs occur |
| 837 | // between points of interest. |
| 838 | |
| 839 | template<int size, bool big_endian> |
| 840 | class Track_relocs |
| 841 | { |
| 842 | public: |
| 843 | Track_relocs() |
| 844 | : prelocs_(NULL), len_(0), pos_(0), reloc_size_(0) |
| 845 | { } |
| 846 | |
| 847 | // Initialize the Track_relocs object. OBJECT is the object holding |
| 848 | // the reloc section, RELOC_SHNDX is the section index of the reloc |
| 849 | // section, and RELOC_TYPE is the type of the reloc section |
| 850 | // (elfcpp::SHT_REL or elfcpp::SHT_RELA). This returns false if |
| 851 | // something went wrong. |
| 852 | bool |
| 853 | initialize(Object* object, unsigned int reloc_shndx, |
| 854 | unsigned int reloc_type); |
| 855 | |
| 856 | // Return the offset in the data section to which the next reloc |
| 857 | // applies. This returns -1 if there is no next reloc. |
| 858 | off_t |
| 859 | next_offset() const; |
| 860 | |
| 861 | // Return the symbol index of the next reloc. This returns -1U if |
| 862 | // there is no next reloc. |
| 863 | unsigned int |
| 864 | next_symndx() const; |
| 865 | |
| 866 | // Return the addend of the next reloc. This returns 0 if there is |
| 867 | // no next reloc. |
| 868 | uint64_t |
| 869 | next_addend() const; |
| 870 | |
| 871 | // Advance to OFFSET within the data section, and return the number |
| 872 | // of relocs which would be skipped. |
| 873 | int |
| 874 | advance(off_t offset); |
| 875 | |
| 876 | // Checkpoint the current position in the reloc section. |
| 877 | section_size_type |
| 878 | checkpoint() const |
| 879 | { return this->pos_; } |
| 880 | |
| 881 | // Reset the position to CHECKPOINT. |
| 882 | void |
| 883 | reset(section_size_type checkpoint) |
| 884 | { this->pos_ = checkpoint; } |
| 885 | |
| 886 | private: |
| 887 | // The contents of the input object's reloc section. |
| 888 | const unsigned char* prelocs_; |
| 889 | // The length of the reloc section. |
| 890 | section_size_type len_; |
| 891 | // Our current position in the reloc section. |
| 892 | section_size_type pos_; |
| 893 | // The size of the relocs in the section. |
| 894 | int reloc_size_; |
| 895 | }; |
| 896 | |
| 897 | } // End namespace gold. |
| 898 | |
| 899 | #endif // !defined(GOLD_RELOC_H) |