1 //===--- Relocation.cpp - Interface for object file relocations ----------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 //===----------------------------------------------------------------------===// 10 11 #include "bolt/Core/Relocation.h" 12 #include "llvm/MC/MCContext.h" 13 #include "llvm/MC/MCStreamer.h" 14 #include "llvm/Object/ELF.h" 15 16 using namespace llvm; 17 using namespace bolt; 18 19 Triple::ArchType Relocation::Arch; 20 21 namespace { 22 23 bool isSupportedX86(uint64_t Type) { 24 switch (Type) { 25 default: 26 return false; 27 case ELF::R_X86_64_8: 28 case ELF::R_X86_64_16: 29 case ELF::R_X86_64_32: 30 case ELF::R_X86_64_32S: 31 case ELF::R_X86_64_64: 32 case ELF::R_X86_64_PC8: 33 case ELF::R_X86_64_PC32: 34 case ELF::R_X86_64_PC64: 35 case ELF::R_X86_64_PLT32: 36 case ELF::R_X86_64_GOTPCREL: 37 case ELF::R_X86_64_GOTTPOFF: 38 case ELF::R_X86_64_TPOFF32: 39 case ELF::R_X86_64_GOTPCRELX: 40 case ELF::R_X86_64_REX_GOTPCRELX: 41 return true; 42 } 43 } 44 45 bool isSupportedAArch64(uint64_t Type) { 46 switch (Type) { 47 default: 48 return false; 49 case ELF::R_AARCH64_CALL26: 50 case ELF::R_AARCH64_JUMP26: 51 case ELF::R_AARCH64_TSTBR14: 52 case ELF::R_AARCH64_CONDBR19: 53 case ELF::R_AARCH64_ADR_PREL_LO21: 54 case ELF::R_AARCH64_ADR_PREL_PG_HI21: 55 case ELF::R_AARCH64_ADR_PREL_PG_HI21_NC: 56 case ELF::R_AARCH64_LDST64_ABS_LO12_NC: 57 case ELF::R_AARCH64_ADD_ABS_LO12_NC: 58 case ELF::R_AARCH64_LDST128_ABS_LO12_NC: 59 case ELF::R_AARCH64_LDST32_ABS_LO12_NC: 60 case ELF::R_AARCH64_LDST16_ABS_LO12_NC: 61 case ELF::R_AARCH64_LDST8_ABS_LO12_NC: 62 case ELF::R_AARCH64_ADR_GOT_PAGE: 63 case ELF::R_AARCH64_TLSDESC_ADR_PREL21: 64 case ELF::R_AARCH64_TLSDESC_ADR_PAGE21: 65 case ELF::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC: 66 case ELF::R_AARCH64_TLSLE_ADD_TPREL_HI12: 67 case ELF::R_AARCH64_TLSLE_ADD_TPREL_LO12_NC: 68 case ELF::R_AARCH64_LD64_GOT_LO12_NC: 69 case ELF::R_AARCH64_TLSDESC_LD64_LO12: 70 case ELF::R_AARCH64_TLSDESC_ADD_LO12: 71 case ELF::R_AARCH64_TLSDESC_CALL: 72 case ELF::R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21: 73 case ELF::R_AARCH64_PREL32: 74 case ELF::R_AARCH64_ABS16: 75 case ELF::R_AARCH64_ABS32: 76 case ELF::R_AARCH64_ABS64: 77 case ELF::R_AARCH64_MOVW_UABS_G0: 78 case ELF::R_AARCH64_MOVW_UABS_G0_NC: 79 case ELF::R_AARCH64_MOVW_UABS_G1: 80 case ELF::R_AARCH64_MOVW_UABS_G1_NC: 81 case ELF::R_AARCH64_MOVW_UABS_G2: 82 case ELF::R_AARCH64_MOVW_UABS_G2_NC: 83 case ELF::R_AARCH64_MOVW_UABS_G3: 84 return true; 85 } 86 } 87 88 size_t getSizeForTypeX86(uint64_t Type) { 89 switch (Type) { 90 default: 91 errs() << object::getELFRelocationTypeName(ELF::EM_X86_64, Type) << '\n'; 92 llvm_unreachable("unsupported relocation type"); 93 case ELF::R_X86_64_8: 94 case ELF::R_X86_64_PC8: 95 return 1; 96 case ELF::R_X86_64_16: 97 return 2; 98 case ELF::R_X86_64_PLT32: 99 case ELF::R_X86_64_PC32: 100 case ELF::R_X86_64_32S: 101 case ELF::R_X86_64_32: 102 case ELF::R_X86_64_GOTPCREL: 103 case ELF::R_X86_64_GOTTPOFF: 104 case ELF::R_X86_64_TPOFF32: 105 case ELF::R_X86_64_GOTPCRELX: 106 case ELF::R_X86_64_REX_GOTPCRELX: 107 return 4; 108 case ELF::R_X86_64_PC64: 109 case ELF::R_X86_64_64: 110 return 8; 111 } 112 } 113 114 size_t getSizeForTypeAArch64(uint64_t Type) { 115 switch (Type) { 116 default: 117 errs() << object::getELFRelocationTypeName(ELF::EM_AARCH64, Type) << '\n'; 118 llvm_unreachable("unsupported relocation type"); 119 case ELF::R_AARCH64_ABS16: 120 return 2; 121 case ELF::R_AARCH64_CALL26: 122 case ELF::R_AARCH64_JUMP26: 123 case ELF::R_AARCH64_TSTBR14: 124 case ELF::R_AARCH64_CONDBR19: 125 case ELF::R_AARCH64_ADR_PREL_LO21: 126 case ELF::R_AARCH64_ADR_PREL_PG_HI21: 127 case ELF::R_AARCH64_ADR_PREL_PG_HI21_NC: 128 case ELF::R_AARCH64_LDST64_ABS_LO12_NC: 129 case ELF::R_AARCH64_ADD_ABS_LO12_NC: 130 case ELF::R_AARCH64_LDST128_ABS_LO12_NC: 131 case ELF::R_AARCH64_LDST32_ABS_LO12_NC: 132 case ELF::R_AARCH64_LDST16_ABS_LO12_NC: 133 case ELF::R_AARCH64_LDST8_ABS_LO12_NC: 134 case ELF::R_AARCH64_ADR_GOT_PAGE: 135 case ELF::R_AARCH64_TLSDESC_ADR_PREL21: 136 case ELF::R_AARCH64_TLSDESC_ADR_PAGE21: 137 case ELF::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC: 138 case ELF::R_AARCH64_TLSLE_ADD_TPREL_HI12: 139 case ELF::R_AARCH64_TLSLE_ADD_TPREL_LO12_NC: 140 case ELF::R_AARCH64_LD64_GOT_LO12_NC: 141 case ELF::R_AARCH64_TLSDESC_LD64_LO12: 142 case ELF::R_AARCH64_TLSDESC_ADD_LO12: 143 case ELF::R_AARCH64_TLSDESC_CALL: 144 case ELF::R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21: 145 case ELF::R_AARCH64_PREL32: 146 case ELF::R_AARCH64_MOVW_UABS_G0: 147 case ELF::R_AARCH64_MOVW_UABS_G0_NC: 148 case ELF::R_AARCH64_MOVW_UABS_G1: 149 case ELF::R_AARCH64_MOVW_UABS_G1_NC: 150 case ELF::R_AARCH64_MOVW_UABS_G2: 151 case ELF::R_AARCH64_MOVW_UABS_G2_NC: 152 case ELF::R_AARCH64_MOVW_UABS_G3: 153 case ELF::R_AARCH64_ABS32: 154 return 4; 155 case ELF::R_AARCH64_ABS64: 156 return 8; 157 } 158 } 159 160 bool skipRelocationProcessX86(uint64_t Type, uint64_t Contents) { 161 return false; 162 } 163 164 bool skipRelocationProcessAArch64(uint64_t Type, uint64_t Contents) { 165 auto IsMov = [](uint64_t Contents) -> bool { 166 // The bits 28-23 are 0b100101 167 if ((Contents & 0x1f800000) == 0x12800000) 168 return true; 169 return false; 170 }; 171 172 auto IsB = [](uint64_t Contents) -> bool { 173 // The bits 31-26 are 0b000101 174 if ((Contents & 0xfc000000) == 0x14000000) 175 return true; 176 return false; 177 }; 178 179 auto IsNop = [](uint64_t Contents) -> bool { return Contents == 0xd503201f; }; 180 181 // The linker might eliminate the instruction and replace it with NOP, ignore 182 if (IsNop(Contents)) 183 return true; 184 185 // The linker might perform TLS relocations relaxations, such as 186 // changed TLS access model (e.g. changed global dynamic model 187 // to initial exec), thus changing the instructions. The static 188 // relocations might be invalid at this point and we might no 189 // need to proccess these relocations anymore. 190 // More information could be found by searching 191 // elfNN_aarch64_tls_relax in bfd 192 switch (Type) { 193 default: 194 break; 195 case ELF::R_AARCH64_TLSDESC_LD64_LO12: 196 case ELF::R_AARCH64_TLSDESC_ADR_PAGE21: 197 case ELF::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC: 198 case ELF::R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21: { 199 if (IsMov(Contents)) 200 return true; 201 } 202 } 203 204 // The ld might replace load/store instruction with jump and 205 // veneer due to errata 843419 206 // https://documentation-service.arm.com/static/5fa29fddb209f547eebd361d 207 // Thus load/store relocations for these instructions must be ignored 208 // NOTE: We only process GOT and TLS relocations this way since the 209 // addend used in load/store instructions won't change after bolt 210 // (it is important since the instruction in veneer won't have relocation) 211 switch (Type) { 212 default: 213 break; 214 case ELF::R_AARCH64_LD64_GOT_LO12_NC: 215 case ELF::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC: 216 case ELF::R_AARCH64_TLSDESC_LD64_LO12: { 217 if (IsB(Contents)) 218 return true; 219 } 220 } 221 222 return false; 223 } 224 225 uint64_t extractValueX86(uint64_t Type, uint64_t Contents, uint64_t PC) { 226 if (Type == ELF::R_X86_64_32S) 227 return SignExtend64<32>(Contents & 0xffffffff); 228 return Contents; 229 } 230 231 uint64_t extractValueAArch64(uint64_t Type, uint64_t Contents, uint64_t PC) { 232 switch (Type) { 233 default: 234 errs() << object::getELFRelocationTypeName(ELF::EM_AARCH64, Type) << '\n'; 235 llvm_unreachable("unsupported relocation type"); 236 case ELF::R_AARCH64_ABS16: 237 case ELF::R_AARCH64_ABS32: 238 case ELF::R_AARCH64_ABS64: 239 return Contents; 240 case ELF::R_AARCH64_PREL32: 241 return static_cast<int64_t>(PC) + SignExtend64<32>(Contents & 0xffffffff); 242 case ELF::R_AARCH64_TLSDESC_CALL: 243 case ELF::R_AARCH64_JUMP26: 244 case ELF::R_AARCH64_CALL26: 245 // Immediate goes in bits 25:0 of B and BL. 246 Contents &= ~0xfffffffffc000000ULL; 247 return static_cast<int64_t>(PC) + SignExtend64<28>(Contents << 2); 248 case ELF::R_AARCH64_TSTBR14: 249 // Immediate:15:2 goes in bits 18:5 of TBZ, TBNZ 250 Contents &= ~0xfffffffffff8001fULL; 251 return static_cast<int64_t>(PC) + SignExtend64<16>(Contents >> 3); 252 case ELF::R_AARCH64_CONDBR19: 253 // Immediate:20:2 goes in bits 23:5 of Bcc, CBZ, CBNZ 254 Contents &= ~0xffffffffff00001fULL; 255 return static_cast<int64_t>(PC) + SignExtend64<21>(Contents >> 3); 256 case ELF::R_AARCH64_ADR_GOT_PAGE: 257 case ELF::R_AARCH64_TLSDESC_ADR_PREL21: 258 case ELF::R_AARCH64_TLSDESC_ADR_PAGE21: 259 case ELF::R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21: 260 case ELF::R_AARCH64_ADR_PREL_LO21: 261 case ELF::R_AARCH64_ADR_PREL_PG_HI21: 262 case ELF::R_AARCH64_ADR_PREL_PG_HI21_NC: { 263 // Bits 32:12 of Symbol address goes in bits 30:29 + 23:5 of ADRP 264 // and ADR instructions 265 bool IsAdr = !!(((Contents >> 31) & 0x1) == 0); 266 Contents &= ~0xffffffff9f00001fUll; 267 uint64_t LowBits = (Contents >> 29) & 0x3; 268 uint64_t HighBits = (Contents >> 5) & 0x7ffff; 269 Contents = LowBits | (HighBits << 2); 270 if (IsAdr) 271 return static_cast<int64_t>(PC) + SignExtend64<21>(Contents); 272 273 // ADRP instruction 274 Contents = static_cast<int64_t>(PC) + SignExtend64<33>(Contents << 12); 275 Contents &= ~0xfffUll; 276 return Contents; 277 } 278 case ELF::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC: 279 case ELF::R_AARCH64_TLSDESC_LD64_LO12: 280 case ELF::R_AARCH64_LD64_GOT_LO12_NC: 281 case ELF::R_AARCH64_LDST64_ABS_LO12_NC: { 282 // Immediate goes in bits 21:10 of LD/ST instruction, taken 283 // from bits 11:3 of Symbol address 284 Contents &= ~0xffffffffffc003ffU; 285 return Contents >> (10 - 3); 286 } 287 case ELF::R_AARCH64_TLSLE_ADD_TPREL_HI12: 288 case ELF::R_AARCH64_TLSLE_ADD_TPREL_LO12_NC: 289 case ELF::R_AARCH64_TLSDESC_ADD_LO12: 290 case ELF::R_AARCH64_ADD_ABS_LO12_NC: { 291 // Immediate goes in bits 21:10 of ADD instruction 292 Contents &= ~0xffffffffffc003ffU; 293 return Contents >> (10 - 0); 294 } 295 case ELF::R_AARCH64_LDST128_ABS_LO12_NC: { 296 // Immediate goes in bits 21:10 of ADD instruction, taken 297 // from bits 11:4 of Symbol address 298 Contents &= ~0xffffffffffc003ffU; 299 return Contents >> (10 - 4); 300 } 301 case ELF::R_AARCH64_LDST32_ABS_LO12_NC: { 302 // Immediate goes in bits 21:10 of ADD instruction, taken 303 // from bits 11:2 of Symbol address 304 Contents &= ~0xffffffffffc003ffU; 305 return Contents >> (10 - 2); 306 } 307 case ELF::R_AARCH64_LDST16_ABS_LO12_NC: { 308 // Immediate goes in bits 21:10 of ADD instruction, taken 309 // from bits 11:1 of Symbol address 310 Contents &= ~0xffffffffffc003ffU; 311 return Contents >> (10 - 1); 312 } 313 case ELF::R_AARCH64_LDST8_ABS_LO12_NC: { 314 // Immediate goes in bits 21:10 of ADD instruction, taken 315 // from bits 11:0 of Symbol address 316 Contents &= ~0xffffffffffc003ffU; 317 return Contents >> (10 - 0); 318 } 319 case ELF::R_AARCH64_MOVW_UABS_G3: 320 case ELF::R_AARCH64_MOVW_UABS_G2_NC: 321 case ELF::R_AARCH64_MOVW_UABS_G2: 322 case ELF::R_AARCH64_MOVW_UABS_G1_NC: 323 case ELF::R_AARCH64_MOVW_UABS_G1: 324 case ELF::R_AARCH64_MOVW_UABS_G0_NC: 325 case ELF::R_AARCH64_MOVW_UABS_G0: 326 // The shift goest in bits 22:21 of MOV* instructions 327 uint8_t Shift = (Contents >> 21) & 0x3; 328 // Immediate goes in bits 20:5 329 Contents = (Contents >> 5) & 0xffff; 330 return Contents << (16 * Shift); 331 } 332 } 333 334 bool isGOTX86(uint64_t Type) { 335 switch (Type) { 336 default: 337 return false; 338 case ELF::R_X86_64_GOT32: 339 case ELF::R_X86_64_GOTPCREL: 340 case ELF::R_X86_64_GOTTPOFF: 341 case ELF::R_X86_64_GOTOFF64: 342 case ELF::R_X86_64_GOTPC32: 343 case ELF::R_X86_64_GOT64: 344 case ELF::R_X86_64_GOTPCREL64: 345 case ELF::R_X86_64_GOTPC64: 346 case ELF::R_X86_64_GOTPLT64: 347 case ELF::R_X86_64_GOTPC32_TLSDESC: 348 case ELF::R_X86_64_GOTPCRELX: 349 case ELF::R_X86_64_REX_GOTPCRELX: 350 return true; 351 } 352 } 353 354 bool isGOTAArch64(uint64_t Type) { 355 switch (Type) { 356 default: 357 return false; 358 case ELF::R_AARCH64_ADR_GOT_PAGE: 359 case ELF::R_AARCH64_LD64_GOT_LO12_NC: 360 case ELF::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC: 361 case ELF::R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21: 362 case ELF::R_AARCH64_TLSDESC_ADR_PREL21: 363 case ELF::R_AARCH64_TLSDESC_ADR_PAGE21: 364 case ELF::R_AARCH64_TLSDESC_LD64_LO12: 365 case ELF::R_AARCH64_TLSDESC_ADD_LO12: 366 case ELF::R_AARCH64_TLSDESC_CALL: 367 return true; 368 } 369 } 370 371 bool isTLSX86(uint64_t Type) { 372 switch (Type) { 373 default: 374 return false; 375 case ELF::R_X86_64_TPOFF32: 376 case ELF::R_X86_64_TPOFF64: 377 case ELF::R_X86_64_GOTTPOFF: 378 return true; 379 } 380 } 381 382 bool isTLSAArch64(uint64_t Type) { 383 switch (Type) { 384 default: 385 return false; 386 case ELF::R_AARCH64_TLSDESC_ADR_PREL21: 387 case ELF::R_AARCH64_TLSDESC_ADR_PAGE21: 388 case ELF::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC: 389 case ELF::R_AARCH64_TLSLE_ADD_TPREL_HI12: 390 case ELF::R_AARCH64_TLSLE_ADD_TPREL_LO12_NC: 391 case ELF::R_AARCH64_TLSDESC_LD64_LO12: 392 case ELF::R_AARCH64_TLSDESC_ADD_LO12: 393 case ELF::R_AARCH64_TLSDESC_CALL: 394 case ELF::R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21: 395 return true; 396 } 397 } 398 399 bool isPCRelativeX86(uint64_t Type) { 400 switch (Type) { 401 default: 402 llvm_unreachable("Unknown relocation type"); 403 case ELF::R_X86_64_64: 404 case ELF::R_X86_64_32: 405 case ELF::R_X86_64_32S: 406 case ELF::R_X86_64_16: 407 case ELF::R_X86_64_8: 408 case ELF::R_X86_64_TPOFF32: 409 return false; 410 case ELF::R_X86_64_PC8: 411 case ELF::R_X86_64_PC32: 412 case ELF::R_X86_64_PC64: 413 case ELF::R_X86_64_GOTPCREL: 414 case ELF::R_X86_64_PLT32: 415 case ELF::R_X86_64_GOTTPOFF: 416 case ELF::R_X86_64_GOTPCRELX: 417 case ELF::R_X86_64_REX_GOTPCRELX: 418 return true; 419 } 420 } 421 422 bool isPCRelativeAArch64(uint64_t Type) { 423 switch (Type) { 424 default: 425 llvm_unreachable("Unknown relocation type"); 426 case ELF::R_AARCH64_ABS16: 427 case ELF::R_AARCH64_ABS32: 428 case ELF::R_AARCH64_ABS64: 429 case ELF::R_AARCH64_LDST64_ABS_LO12_NC: 430 case ELF::R_AARCH64_ADD_ABS_LO12_NC: 431 case ELF::R_AARCH64_LDST128_ABS_LO12_NC: 432 case ELF::R_AARCH64_LDST32_ABS_LO12_NC: 433 case ELF::R_AARCH64_LDST16_ABS_LO12_NC: 434 case ELF::R_AARCH64_LDST8_ABS_LO12_NC: 435 case ELF::R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC: 436 case ELF::R_AARCH64_TLSLE_ADD_TPREL_HI12: 437 case ELF::R_AARCH64_TLSLE_ADD_TPREL_LO12_NC: 438 case ELF::R_AARCH64_LD64_GOT_LO12_NC: 439 case ELF::R_AARCH64_TLSDESC_LD64_LO12: 440 case ELF::R_AARCH64_TLSDESC_ADD_LO12: 441 case ELF::R_AARCH64_MOVW_UABS_G0: 442 case ELF::R_AARCH64_MOVW_UABS_G0_NC: 443 case ELF::R_AARCH64_MOVW_UABS_G1: 444 case ELF::R_AARCH64_MOVW_UABS_G1_NC: 445 case ELF::R_AARCH64_MOVW_UABS_G2: 446 case ELF::R_AARCH64_MOVW_UABS_G2_NC: 447 case ELF::R_AARCH64_MOVW_UABS_G3: 448 return false; 449 case ELF::R_AARCH64_TLSDESC_CALL: 450 case ELF::R_AARCH64_CALL26: 451 case ELF::R_AARCH64_JUMP26: 452 case ELF::R_AARCH64_TSTBR14: 453 case ELF::R_AARCH64_CONDBR19: 454 case ELF::R_AARCH64_ADR_PREL_LO21: 455 case ELF::R_AARCH64_ADR_PREL_PG_HI21: 456 case ELF::R_AARCH64_ADR_PREL_PG_HI21_NC: 457 case ELF::R_AARCH64_ADR_GOT_PAGE: 458 case ELF::R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21: 459 case ELF::R_AARCH64_TLSDESC_ADR_PREL21: 460 case ELF::R_AARCH64_TLSDESC_ADR_PAGE21: 461 case ELF::R_AARCH64_PREL32: 462 return true; 463 } 464 } 465 466 } // end anonymous namespace 467 468 bool Relocation::isSupported(uint64_t Type) { 469 if (Arch == Triple::aarch64) 470 return isSupportedAArch64(Type); 471 return isSupportedX86(Type); 472 } 473 474 size_t Relocation::getSizeForType(uint64_t Type) { 475 if (Arch == Triple::aarch64) 476 return getSizeForTypeAArch64(Type); 477 return getSizeForTypeX86(Type); 478 } 479 480 bool Relocation::skipRelocationProcess(uint64_t Type, uint64_t Contents) { 481 if (Arch == Triple::aarch64) 482 return skipRelocationProcessAArch64(Type, Contents); 483 return skipRelocationProcessX86(Type, Contents); 484 } 485 486 uint64_t Relocation::extractValue(uint64_t Type, uint64_t Contents, 487 uint64_t PC) { 488 if (Arch == Triple::aarch64) 489 return extractValueAArch64(Type, Contents, PC); 490 return extractValueX86(Type, Contents, PC); 491 } 492 493 bool Relocation::isGOT(uint64_t Type) { 494 if (Arch == Triple::aarch64) 495 return isGOTAArch64(Type); 496 return isGOTX86(Type); 497 } 498 499 bool Relocation::isNone(uint64_t Type) { 500 if (Arch == Triple::aarch64) 501 return Type == ELF::R_AARCH64_NONE; 502 return Type == ELF::R_X86_64_NONE; 503 } 504 505 bool Relocation::isRelative(uint64_t Type) { 506 if (Arch == Triple::aarch64) 507 return Type == ELF::R_AARCH64_RELATIVE; 508 return Type == ELF::R_X86_64_RELATIVE; 509 } 510 511 bool Relocation::isIRelative(uint64_t Type) { 512 if (Arch == Triple::aarch64) 513 return Type == ELF::R_AARCH64_IRELATIVE; 514 return Type == ELF::R_X86_64_IRELATIVE; 515 } 516 517 bool Relocation::isTLS(uint64_t Type) { 518 if (Arch == Triple::aarch64) 519 return isTLSAArch64(Type); 520 return isTLSX86(Type); 521 } 522 523 bool Relocation::isPCRelative(uint64_t Type) { 524 if (Arch == Triple::aarch64) 525 return isPCRelativeAArch64(Type); 526 return isPCRelativeX86(Type); 527 } 528 529 uint64_t Relocation::getPC32() { 530 if (Arch == Triple::aarch64) 531 return ELF::R_AARCH64_PREL32; 532 return ELF::R_X86_64_PC32; 533 } 534 535 uint64_t Relocation::getPC64() { 536 if (Arch == Triple::aarch64) 537 return ELF::R_AARCH64_PREL64; 538 return ELF::R_X86_64_PC64; 539 } 540 541 size_t Relocation::emit(MCStreamer *Streamer) const { 542 const size_t Size = getSizeForType(Type); 543 MCContext &Ctx = Streamer->getContext(); 544 if (isPCRelative(Type)) { 545 MCSymbol *TempLabel = Ctx.createNamedTempSymbol(); 546 Streamer->emitLabel(TempLabel); 547 const MCExpr *Value = nullptr; 548 if (Symbol) { 549 Value = MCSymbolRefExpr::create(Symbol, Ctx); 550 if (Addend) { 551 Value = MCBinaryExpr::createAdd( 552 Value, MCConstantExpr::create(Addend, Ctx), Ctx); 553 } 554 } else { 555 Value = MCConstantExpr::create(Addend, Ctx); 556 } 557 Value = MCBinaryExpr::createSub( 558 Value, MCSymbolRefExpr::create(TempLabel, Ctx), Ctx); 559 Streamer->emitValue(Value, Size); 560 561 return Size; 562 } 563 564 if (Symbol && Addend) { 565 auto Value = 566 MCBinaryExpr::createAdd(MCSymbolRefExpr::create(Symbol, Ctx), 567 MCConstantExpr::create(Addend, Ctx), Ctx); 568 Streamer->emitValue(Value, Size); 569 } else if (Symbol) { 570 Streamer->emitSymbolValue(Symbol, Size); 571 } else { 572 Streamer->emitIntValue(Addend, Size); 573 } 574 575 return Size; 576 } 577 578 #define ELF_RELOC(name, value) #name, 579 580 void Relocation::print(raw_ostream &OS) const { 581 static const char *X86RelocNames[] = { 582 #include "llvm/BinaryFormat/ELFRelocs/x86_64.def" 583 }; 584 static const char *AArch64RelocNames[] = { 585 #include "llvm/BinaryFormat/ELFRelocs/AArch64.def" 586 }; 587 if (Arch == Triple::aarch64) 588 OS << AArch64RelocNames[Type]; 589 else 590 OS << X86RelocNames[Type]; 591 OS << ", 0x" << Twine::utohexstr(Offset); 592 if (Symbol) { 593 OS << ", " << Symbol->getName(); 594 } 595 if (int64_t(Addend) < 0) 596 OS << ", -0x" << Twine::utohexstr(-int64_t(Addend)); 597 else 598 OS << ", 0x" << Twine::utohexstr(Addend); 599 OS << ", 0x" << Twine::utohexstr(Value); 600 } 601