1 //===------- ELF_riscv.cpp -JIT linker implementation for ELF/riscv -------===// 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 // ELF/riscv jit-link implementation. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "llvm/ExecutionEngine/JITLink/ELF_riscv.h" 14 #include "ELFLinkGraphBuilder.h" 15 #include "JITLinkGeneric.h" 16 #include "PerGraphGOTAndPLTStubsBuilder.h" 17 #include "llvm/BinaryFormat/ELF.h" 18 #include "llvm/ExecutionEngine/JITLink/JITLink.h" 19 #include "llvm/ExecutionEngine/JITLink/riscv.h" 20 #include "llvm/Object/ELF.h" 21 #include "llvm/Object/ELFObjectFile.h" 22 #include "llvm/Support/Endian.h" 23 24 #define DEBUG_TYPE "jitlink" 25 using namespace llvm; 26 using namespace llvm::jitlink; 27 using namespace llvm::jitlink::riscv; 28 29 namespace { 30 31 class PerGraphGOTAndPLTStubsBuilder_ELF_riscv 32 : public PerGraphGOTAndPLTStubsBuilder< 33 PerGraphGOTAndPLTStubsBuilder_ELF_riscv> { 34 public: 35 static constexpr size_t StubEntrySize = 16; 36 static const uint8_t NullGOTEntryContent[8]; 37 static const uint8_t RV64StubContent[StubEntrySize]; 38 static const uint8_t RV32StubContent[StubEntrySize]; 39 40 using PerGraphGOTAndPLTStubsBuilder< 41 PerGraphGOTAndPLTStubsBuilder_ELF_riscv>::PerGraphGOTAndPLTStubsBuilder; 42 43 bool isRV64() const { return G.getPointerSize() == 8; } 44 45 bool isGOTEdgeToFix(Edge &E) const { return E.getKind() == R_RISCV_GOT_HI20; } 46 47 Symbol &createGOTEntry(Symbol &Target) { 48 Block &GOTBlock = 49 G.createContentBlock(getGOTSection(), getGOTEntryBlockContent(), 50 orc::ExecutorAddr(), G.getPointerSize(), 0); 51 GOTBlock.addEdge(isRV64() ? R_RISCV_64 : R_RISCV_32, 0, Target, 0); 52 return G.addAnonymousSymbol(GOTBlock, 0, G.getPointerSize(), false, false); 53 } 54 55 Symbol &createPLTStub(Symbol &Target) { 56 Block &StubContentBlock = G.createContentBlock( 57 getStubsSection(), getStubBlockContent(), orc::ExecutorAddr(), 4, 0); 58 auto &GOTEntrySymbol = getGOTEntry(Target); 59 StubContentBlock.addEdge(R_RISCV_CALL, 0, GOTEntrySymbol, 0); 60 return G.addAnonymousSymbol(StubContentBlock, 0, StubEntrySize, true, 61 false); 62 } 63 64 void fixGOTEdge(Edge &E, Symbol &GOTEntry) { 65 // Replace the relocation pair (R_RISCV_GOT_HI20, R_RISCV_PCREL_LO12) 66 // with (R_RISCV_PCREL_HI20, R_RISCV_PCREL_LO12) 67 // Therefore, here just change the R_RISCV_GOT_HI20 to R_RISCV_PCREL_HI20 68 E.setKind(R_RISCV_PCREL_HI20); 69 E.setTarget(GOTEntry); 70 } 71 72 void fixPLTEdge(Edge &E, Symbol &PLTStubs) { 73 assert(E.getKind() == R_RISCV_CALL_PLT && "Not a R_RISCV_CALL_PLT edge?"); 74 E.setKind(R_RISCV_CALL); 75 E.setTarget(PLTStubs); 76 } 77 78 bool isExternalBranchEdge(Edge &E) const { 79 return E.getKind() == R_RISCV_CALL_PLT; 80 } 81 82 private: 83 Section &getGOTSection() const { 84 if (!GOTSection) 85 GOTSection = &G.createSection("$__GOT", orc::MemProt::Read); 86 return *GOTSection; 87 } 88 89 Section &getStubsSection() const { 90 if (!StubsSection) 91 StubsSection = 92 &G.createSection("$__STUBS", orc::MemProt::Read | orc::MemProt::Exec); 93 return *StubsSection; 94 } 95 96 ArrayRef<char> getGOTEntryBlockContent() { 97 return {reinterpret_cast<const char *>(NullGOTEntryContent), 98 G.getPointerSize()}; 99 } 100 101 ArrayRef<char> getStubBlockContent() { 102 auto StubContent = isRV64() ? RV64StubContent : RV32StubContent; 103 return {reinterpret_cast<const char *>(StubContent), StubEntrySize}; 104 } 105 106 mutable Section *GOTSection = nullptr; 107 mutable Section *StubsSection = nullptr; 108 }; 109 110 const uint8_t PerGraphGOTAndPLTStubsBuilder_ELF_riscv::NullGOTEntryContent[8] = 111 {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}; 112 113 const uint8_t 114 PerGraphGOTAndPLTStubsBuilder_ELF_riscv::RV64StubContent[StubEntrySize] = { 115 0x17, 0x0e, 0x00, 0x00, // auipc t3, literal 116 0x03, 0x3e, 0x0e, 0x00, // ld t3, literal(t3) 117 0x67, 0x00, 0x0e, 0x00, // jr t3 118 0x13, 0x00, 0x00, 0x00}; // nop 119 120 const uint8_t 121 PerGraphGOTAndPLTStubsBuilder_ELF_riscv::RV32StubContent[StubEntrySize] = { 122 0x17, 0x0e, 0x00, 0x00, // auipc t3, literal 123 0x03, 0x2e, 0x0e, 0x00, // lw t3, literal(t3) 124 0x67, 0x00, 0x0e, 0x00, // jr t3 125 0x13, 0x00, 0x00, 0x00}; // nop 126 } // namespace 127 namespace llvm { 128 namespace jitlink { 129 130 static Expected<const Edge &> getRISCVPCRelHi20(const Edge &E) { 131 using namespace riscv; 132 assert((E.getKind() == R_RISCV_PCREL_LO12_I || 133 E.getKind() == R_RISCV_PCREL_LO12_S) && 134 "Can only have high relocation for R_RISCV_PCREL_LO12_I or " 135 "R_RISCV_PCREL_LO12_S"); 136 137 const Symbol &Sym = E.getTarget(); 138 const Block &B = Sym.getBlock(); 139 orc::ExecutorAddrDiff Offset = Sym.getOffset(); 140 141 struct Comp { 142 bool operator()(const Edge &Lhs, orc::ExecutorAddrDiff Offset) { 143 return Lhs.getOffset() < Offset; 144 } 145 bool operator()(orc::ExecutorAddrDiff Offset, const Edge &Rhs) { 146 return Offset < Rhs.getOffset(); 147 } 148 }; 149 150 auto Bound = 151 std::equal_range(B.edges().begin(), B.edges().end(), Offset, Comp{}); 152 153 for (auto It = Bound.first; It != Bound.second; ++It) { 154 if (It->getKind() == R_RISCV_PCREL_HI20) 155 return *It; 156 } 157 158 return make_error<JITLinkError>( 159 "No HI20 PCREL relocation type be found for LO12 PCREL relocation type"); 160 } 161 162 static uint32_t extractBits(uint32_t Num, unsigned Low, unsigned Size) { 163 return (Num & (((1ULL << Size) - 1) << Low)) >> Low; 164 } 165 166 static inline bool isAlignmentCorrect(uint64_t Value, int N) { 167 return (Value & (N - 1)) ? false : true; 168 } 169 170 // Requires 0 < N <= 64. 171 static inline bool isInRangeForImm(int64_t Value, int N) { 172 return Value == llvm::SignExtend64(Value, N); 173 } 174 175 class ELFJITLinker_riscv : public JITLinker<ELFJITLinker_riscv> { 176 friend class JITLinker<ELFJITLinker_riscv>; 177 178 public: 179 ELFJITLinker_riscv(std::unique_ptr<JITLinkContext> Ctx, 180 std::unique_ptr<LinkGraph> G, PassConfiguration PassConfig) 181 : JITLinker(std::move(Ctx), std::move(G), std::move(PassConfig)) {} 182 183 private: 184 Error applyFixup(LinkGraph &G, Block &B, const Edge &E) const { 185 using namespace riscv; 186 using namespace llvm::support; 187 188 char *BlockWorkingMem = B.getAlreadyMutableContent().data(); 189 char *FixupPtr = BlockWorkingMem + E.getOffset(); 190 orc::ExecutorAddr FixupAddress = B.getAddress() + E.getOffset(); 191 switch (E.getKind()) { 192 case R_RISCV_32: { 193 int64_t Value = (E.getTarget().getAddress() + E.getAddend()).getValue(); 194 *(little32_t *)FixupPtr = static_cast<uint32_t>(Value); 195 break; 196 } 197 case R_RISCV_64: { 198 int64_t Value = (E.getTarget().getAddress() + E.getAddend()).getValue(); 199 *(little64_t *)FixupPtr = static_cast<uint64_t>(Value); 200 break; 201 } 202 case R_RISCV_BRANCH: { 203 int64_t Value = E.getTarget().getAddress() + E.getAddend() - FixupAddress; 204 if (LLVM_UNLIKELY(!isInRangeForImm(Value >> 1, 12))) 205 return makeTargetOutOfRangeError(G, B, E); 206 if (LLVM_UNLIKELY(!isAlignmentCorrect(Value, 2))) 207 return makeAlignmentError(FixupAddress, Value, 2, E); 208 uint32_t Imm31_25 = 209 extractBits(Value, 5, 6) << 25 | extractBits(Value, 12, 1) << 31; 210 uint32_t Imm11_7 = 211 extractBits(Value, 1, 4) << 8 | extractBits(Value, 11, 1) << 7; 212 uint32_t RawInstr = *(little32_t *)FixupPtr; 213 *(little32_t *)FixupPtr = (RawInstr & 0x1FFF07F) | Imm31_25 | Imm11_7; 214 break; 215 } 216 case R_RISCV_JAL: { 217 int64_t Value = E.getTarget().getAddress() + E.getAddend() - FixupAddress; 218 if (LLVM_UNLIKELY(!isInRangeForImm(Value >> 1, 20))) 219 return makeTargetOutOfRangeError(G, B, E); 220 if (LLVM_UNLIKELY(!isAlignmentCorrect(Value, 2))) 221 return makeAlignmentError(FixupAddress, Value, 2, E); 222 uint32_t Imm20 = extractBits(Value, 20, 1) << 31; 223 uint32_t Imm10_1 = extractBits(Value, 1, 10) << 21; 224 uint32_t Imm11 = extractBits(Value, 11, 1) << 20; 225 uint32_t Imm19_12 = extractBits(Value, 12, 8) << 12; 226 uint32_t RawInstr = *(little32_t *)FixupPtr; 227 *(little32_t *)FixupPtr = RawInstr | Imm20 | Imm10_1 | Imm11 | Imm19_12; 228 break; 229 } 230 case R_RISCV_HI20: { 231 int64_t Value = (E.getTarget().getAddress() + E.getAddend()).getValue(); 232 int64_t Hi = Value + 0x800; 233 if (LLVM_UNLIKELY(!isInRangeForImm(Hi, 32))) 234 return makeTargetOutOfRangeError(G, B, E); 235 uint32_t RawInstr = *(little32_t *)FixupPtr; 236 *(little32_t *)FixupPtr = 237 (RawInstr & 0xFFF) | (static_cast<uint32_t>(Hi & 0xFFFFF000)); 238 break; 239 } 240 case R_RISCV_LO12_I: { 241 // FIXME: We assume that R_RISCV_HI20 is present in object code and pairs 242 // with current relocation R_RISCV_LO12_I. So here may need a check. 243 int64_t Value = (E.getTarget().getAddress() + E.getAddend()).getValue(); 244 int32_t Lo = Value & 0xFFF; 245 uint32_t RawInstr = *(little32_t *)FixupPtr; 246 *(little32_t *)FixupPtr = 247 (RawInstr & 0xFFFFF) | (static_cast<uint32_t>(Lo & 0xFFF) << 20); 248 break; 249 } 250 case R_RISCV_LO12_S: { 251 // FIXME: We assume that R_RISCV_HI20 is present in object code and pairs 252 // with current relocation R_RISCV_LO12_S. So here may need a check. 253 int64_t Value = (E.getTarget().getAddress() + E.getAddend()).getValue(); 254 int64_t Lo = Value & 0xFFF; 255 uint32_t Imm31_25 = extractBits(Lo, 5, 7) << 25; 256 uint32_t Imm11_7 = extractBits(Lo, 0, 5) << 7; 257 uint32_t RawInstr = *(little32_t *)FixupPtr; 258 *(little32_t *)FixupPtr = (RawInstr & 0x1FFF07F) | Imm31_25 | Imm11_7; 259 break; 260 } 261 case R_RISCV_CALL: { 262 int64_t Value = E.getTarget().getAddress() + E.getAddend() - FixupAddress; 263 int64_t Hi = Value + 0x800; 264 if (LLVM_UNLIKELY(!isInRangeForImm(Hi, 32))) 265 return makeTargetOutOfRangeError(G, B, E); 266 int32_t Lo = Value & 0xFFF; 267 uint32_t RawInstrAuipc = *(little32_t *)FixupPtr; 268 uint32_t RawInstrJalr = *(little32_t *)(FixupPtr + 4); 269 *(little32_t *)FixupPtr = 270 RawInstrAuipc | (static_cast<uint32_t>(Hi & 0xFFFFF000)); 271 *(little32_t *)(FixupPtr + 4) = 272 RawInstrJalr | (static_cast<uint32_t>(Lo) << 20); 273 break; 274 } 275 case R_RISCV_PCREL_HI20: { 276 int64_t Value = E.getTarget().getAddress() + E.getAddend() - FixupAddress; 277 int64_t Hi = Value + 0x800; 278 if (LLVM_UNLIKELY(!isInRangeForImm(Hi, 32))) 279 return makeTargetOutOfRangeError(G, B, E); 280 uint32_t RawInstr = *(little32_t *)FixupPtr; 281 *(little32_t *)FixupPtr = 282 (RawInstr & 0xFFF) | (static_cast<uint32_t>(Hi & 0xFFFFF000)); 283 break; 284 } 285 case R_RISCV_PCREL_LO12_I: { 286 // FIXME: We assume that R_RISCV_PCREL_HI20 is present in object code and 287 // pairs with current relocation R_RISCV_PCREL_LO12_I. So here may need a 288 // check. 289 auto RelHI20 = getRISCVPCRelHi20(E); 290 if (!RelHI20) 291 return RelHI20.takeError(); 292 int64_t Value = RelHI20->getTarget().getAddress() + 293 RelHI20->getAddend() - E.getTarget().getAddress(); 294 int64_t Lo = Value & 0xFFF; 295 uint32_t RawInstr = *(little32_t *)FixupPtr; 296 *(little32_t *)FixupPtr = 297 (RawInstr & 0xFFFFF) | (static_cast<uint32_t>(Lo & 0xFFF) << 20); 298 break; 299 } 300 case R_RISCV_PCREL_LO12_S: { 301 // FIXME: We assume that R_RISCV_PCREL_HI20 is present in object code and 302 // pairs with current relocation R_RISCV_PCREL_LO12_S. So here may need a 303 // check. 304 auto RelHI20 = getRISCVPCRelHi20(E); 305 int64_t Value = RelHI20->getTarget().getAddress() + 306 RelHI20->getAddend() - E.getTarget().getAddress(); 307 int64_t Lo = Value & 0xFFF; 308 uint32_t Imm31_25 = extractBits(Lo, 5, 7) << 25; 309 uint32_t Imm11_7 = extractBits(Lo, 0, 5) << 7; 310 uint32_t RawInstr = *(little32_t *)FixupPtr; 311 312 *(little32_t *)FixupPtr = (RawInstr & 0x1FFF07F) | Imm31_25 | Imm11_7; 313 break; 314 } 315 case R_RISCV_ADD64: { 316 int64_t Value = (E.getTarget().getAddress() + 317 support::endian::read64le(reinterpret_cast<const void *>( 318 FixupAddress.getValue())) + 319 E.getAddend()) 320 .getValue(); 321 *(little64_t *)FixupPtr = static_cast<uint64_t>(Value); 322 break; 323 } 324 case R_RISCV_ADD32: { 325 int64_t Value = (E.getTarget().getAddress() + 326 support::endian::read32le(reinterpret_cast<const void *>( 327 FixupAddress.getValue())) + 328 E.getAddend()) 329 .getValue(); 330 *(little32_t *)FixupPtr = static_cast<uint32_t>(Value); 331 break; 332 } 333 case R_RISCV_ADD16: { 334 int64_t Value = (E.getTarget().getAddress() + 335 support::endian::read16le(reinterpret_cast<const void *>( 336 FixupAddress.getValue())) + 337 E.getAddend()) 338 .getValue(); 339 *(little16_t *)FixupPtr = static_cast<uint32_t>(Value); 340 break; 341 } 342 case R_RISCV_ADD8: { 343 int64_t Value = 344 (E.getTarget().getAddress() + 345 *(reinterpret_cast<const uint8_t *>(FixupAddress.getValue())) + 346 E.getAddend()) 347 .getValue(); 348 *FixupPtr = static_cast<uint8_t>(Value); 349 break; 350 } 351 case R_RISCV_SUB64: { 352 int64_t Value = support::endian::read64le(reinterpret_cast<const void *>( 353 FixupAddress.getValue())) - 354 E.getTarget().getAddress().getValue() - E.getAddend(); 355 *(little64_t *)FixupPtr = static_cast<uint64_t>(Value); 356 break; 357 } 358 case R_RISCV_SUB32: { 359 int64_t Value = support::endian::read32le(reinterpret_cast<const void *>( 360 FixupAddress.getValue())) - 361 E.getTarget().getAddress().getValue() - E.getAddend(); 362 *(little32_t *)FixupPtr = static_cast<uint32_t>(Value); 363 break; 364 } 365 case R_RISCV_SUB16: { 366 int64_t Value = support::endian::read16le(reinterpret_cast<const void *>( 367 FixupAddress.getValue())) - 368 E.getTarget().getAddress().getValue() - E.getAddend(); 369 *(little16_t *)FixupPtr = static_cast<uint32_t>(Value); 370 break; 371 } 372 case R_RISCV_SUB8: { 373 int64_t Value = 374 *(reinterpret_cast<const uint8_t *>(FixupAddress.getValue())) - 375 E.getTarget().getAddress().getValue() - E.getAddend(); 376 *FixupPtr = static_cast<uint8_t>(Value); 377 break; 378 } 379 case R_RISCV_SUB6: { 380 int64_t Value = 381 *(reinterpret_cast<const uint8_t *>(FixupAddress.getValue())) & 0x3f; 382 Value -= E.getTarget().getAddress().getValue() - E.getAddend(); 383 *FixupPtr = (*FixupPtr & 0xc0) | (static_cast<uint8_t>(Value) & 0x3f); 384 break; 385 } 386 case R_RISCV_SET6: { 387 int64_t Value = (E.getTarget().getAddress() + E.getAddend()).getValue(); 388 uint32_t RawData = *(little32_t *)FixupPtr; 389 int64_t Word6 = Value & 0x3f; 390 *(little32_t *)FixupPtr = (RawData & 0xffffffc0) | Word6; 391 break; 392 } 393 case R_RISCV_SET8: { 394 int64_t Value = (E.getTarget().getAddress() + E.getAddend()).getValue(); 395 uint32_t RawData = *(little32_t *)FixupPtr; 396 int64_t Word8 = Value & 0xff; 397 *(little32_t *)FixupPtr = (RawData & 0xffffff00) | Word8; 398 break; 399 } 400 case R_RISCV_SET16: { 401 int64_t Value = (E.getTarget().getAddress() + E.getAddend()).getValue(); 402 uint32_t RawData = *(little32_t *)FixupPtr; 403 int64_t Word16 = Value & 0xffff; 404 *(little32_t *)FixupPtr = (RawData & 0xffff0000) | Word16; 405 break; 406 } 407 case R_RISCV_SET32: { 408 int64_t Value = (E.getTarget().getAddress() + E.getAddend()).getValue(); 409 int64_t Word32 = Value & 0xffffffff; 410 *(little32_t *)FixupPtr = Word32; 411 break; 412 } 413 case R_RISCV_32_PCREL: { 414 int64_t Value = E.getTarget().getAddress() + E.getAddend() - FixupAddress; 415 int64_t Word32 = Value & 0xffffffff; 416 *(little32_t *)FixupPtr = Word32; 417 break; 418 } 419 } 420 return Error::success(); 421 } 422 }; 423 424 template <typename ELFT> 425 class ELFLinkGraphBuilder_riscv : public ELFLinkGraphBuilder<ELFT> { 426 private: 427 static Expected<riscv::EdgeKind_riscv> 428 getRelocationKind(const uint32_t Type) { 429 using namespace riscv; 430 switch (Type) { 431 case ELF::R_RISCV_32: 432 return EdgeKind_riscv::R_RISCV_32; 433 case ELF::R_RISCV_64: 434 return EdgeKind_riscv::R_RISCV_64; 435 case ELF::R_RISCV_BRANCH: 436 return EdgeKind_riscv::R_RISCV_BRANCH; 437 case ELF::R_RISCV_JAL: 438 return EdgeKind_riscv::R_RISCV_JAL; 439 case ELF::R_RISCV_HI20: 440 return EdgeKind_riscv::R_RISCV_HI20; 441 case ELF::R_RISCV_LO12_I: 442 return EdgeKind_riscv::R_RISCV_LO12_I; 443 case ELF::R_RISCV_LO12_S: 444 return EdgeKind_riscv::R_RISCV_LO12_S; 445 case ELF::R_RISCV_CALL: 446 return EdgeKind_riscv::R_RISCV_CALL; 447 case ELF::R_RISCV_PCREL_HI20: 448 return EdgeKind_riscv::R_RISCV_PCREL_HI20; 449 case ELF::R_RISCV_PCREL_LO12_I: 450 return EdgeKind_riscv::R_RISCV_PCREL_LO12_I; 451 case ELF::R_RISCV_PCREL_LO12_S: 452 return EdgeKind_riscv::R_RISCV_PCREL_LO12_S; 453 case ELF::R_RISCV_GOT_HI20: 454 return EdgeKind_riscv::R_RISCV_GOT_HI20; 455 case ELF::R_RISCV_CALL_PLT: 456 return EdgeKind_riscv::R_RISCV_CALL_PLT; 457 case ELF::R_RISCV_ADD64: 458 return EdgeKind_riscv::R_RISCV_ADD64; 459 case ELF::R_RISCV_ADD32: 460 return EdgeKind_riscv::R_RISCV_ADD32; 461 case ELF::R_RISCV_ADD16: 462 return EdgeKind_riscv::R_RISCV_ADD16; 463 case ELF::R_RISCV_ADD8: 464 return EdgeKind_riscv::R_RISCV_ADD8; 465 case ELF::R_RISCV_SUB64: 466 return EdgeKind_riscv::R_RISCV_SUB64; 467 case ELF::R_RISCV_SUB32: 468 return EdgeKind_riscv::R_RISCV_SUB32; 469 case ELF::R_RISCV_SUB16: 470 return EdgeKind_riscv::R_RISCV_SUB16; 471 case ELF::R_RISCV_SUB8: 472 return EdgeKind_riscv::R_RISCV_SUB8; 473 case ELF::R_RISCV_SUB6: 474 return EdgeKind_riscv::R_RISCV_SUB6; 475 case ELF::R_RISCV_SET6: 476 return EdgeKind_riscv::R_RISCV_SET6; 477 case ELF::R_RISCV_SET8: 478 return EdgeKind_riscv::R_RISCV_SET8; 479 case ELF::R_RISCV_SET16: 480 return EdgeKind_riscv::R_RISCV_SET16; 481 case ELF::R_RISCV_SET32: 482 return EdgeKind_riscv::R_RISCV_SET32; 483 case ELF::R_RISCV_32_PCREL: 484 return EdgeKind_riscv::R_RISCV_32_PCREL; 485 } 486 487 return make_error<JITLinkError>( 488 "Unsupported riscv relocation:" + formatv("{0:d}: ", Type) + 489 object::getELFRelocationTypeName(ELF::EM_RISCV, Type)); 490 } 491 492 Error addRelocations() override { 493 LLVM_DEBUG(dbgs() << "Processing relocations:\n"); 494 495 using Base = ELFLinkGraphBuilder<ELFT>; 496 using Self = ELFLinkGraphBuilder_riscv<ELFT>; 497 for (const auto &RelSect : Base::Sections) 498 if (Error Err = Base::forEachRelaRelocation(RelSect, this, 499 &Self::addSingleRelocation)) 500 return Err; 501 502 return Error::success(); 503 } 504 505 Error addSingleRelocation(const typename ELFT::Rela &Rel, 506 const typename ELFT::Shdr &FixupSect, 507 Block &BlockToFix) { 508 using Base = ELFLinkGraphBuilder<ELFT>; 509 510 uint32_t Type = Rel.getType(false); 511 // We do not implement linker relaxation, except what is required for 512 // alignment (see below). 513 if (Type == llvm::ELF::R_RISCV_RELAX) 514 return Error::success(); 515 516 int64_t Addend = Rel.r_addend; 517 if (Type == llvm::ELF::R_RISCV_ALIGN) { 518 uint64_t Alignment = PowerOf2Ceil(Addend); 519 // FIXME: Implement support for ensuring alignment together with linker 520 // relaxation; 2 bytes are guaranteed by the length of compressed 521 // instructions, so this does not need any action from our side. 522 if (Alignment > 2) 523 return make_error<JITLinkError>( 524 formatv("Unsupported relocation R_RISCV_ALIGN with alignment {0} " 525 "larger than 2 (addend: {1})", 526 Alignment, Addend)); 527 return Error::success(); 528 } 529 530 Expected<riscv::EdgeKind_riscv> Kind = getRelocationKind(Type); 531 if (!Kind) 532 return Kind.takeError(); 533 534 uint32_t SymbolIndex = Rel.getSymbol(false); 535 auto ObjSymbol = Base::Obj.getRelocationSymbol(Rel, Base::SymTabSec); 536 if (!ObjSymbol) 537 return ObjSymbol.takeError(); 538 539 Symbol *GraphSymbol = Base::getGraphSymbol(SymbolIndex); 540 if (!GraphSymbol) 541 return make_error<StringError>( 542 formatv("Could not find symbol at given index, did you add it to " 543 "JITSymbolTable? index: {0}, shndx: {1} Size of table: {2}", 544 SymbolIndex, (*ObjSymbol)->st_shndx, 545 Base::GraphSymbols.size()), 546 inconvertibleErrorCode()); 547 548 auto FixupAddress = orc::ExecutorAddr(FixupSect.sh_addr) + Rel.r_offset; 549 Edge::OffsetT Offset = FixupAddress - BlockToFix.getAddress(); 550 Edge GE(*Kind, Offset, *GraphSymbol, Addend); 551 LLVM_DEBUG({ 552 dbgs() << " "; 553 printEdge(dbgs(), BlockToFix, GE, riscv::getEdgeKindName(*Kind)); 554 dbgs() << "\n"; 555 }); 556 557 BlockToFix.addEdge(std::move(GE)); 558 return Error::success(); 559 } 560 561 public: 562 ELFLinkGraphBuilder_riscv(StringRef FileName, 563 const object::ELFFile<ELFT> &Obj, const Triple T) 564 : ELFLinkGraphBuilder<ELFT>(Obj, std::move(T), FileName, 565 riscv::getEdgeKindName) {} 566 }; 567 568 Expected<std::unique_ptr<LinkGraph>> 569 createLinkGraphFromELFObject_riscv(MemoryBufferRef ObjectBuffer) { 570 LLVM_DEBUG({ 571 dbgs() << "Building jitlink graph for new input " 572 << ObjectBuffer.getBufferIdentifier() << "...\n"; 573 }); 574 575 auto ELFObj = object::ObjectFile::createELFObjectFile(ObjectBuffer); 576 if (!ELFObj) 577 return ELFObj.takeError(); 578 579 if ((*ELFObj)->getArch() == Triple::riscv64) { 580 auto &ELFObjFile = cast<object::ELFObjectFile<object::ELF64LE>>(**ELFObj); 581 return ELFLinkGraphBuilder_riscv<object::ELF64LE>( 582 (*ELFObj)->getFileName(), ELFObjFile.getELFFile(), 583 (*ELFObj)->makeTriple()) 584 .buildGraph(); 585 } else { 586 assert((*ELFObj)->getArch() == Triple::riscv32 && 587 "Invalid triple for RISCV ELF object file"); 588 auto &ELFObjFile = cast<object::ELFObjectFile<object::ELF32LE>>(**ELFObj); 589 return ELFLinkGraphBuilder_riscv<object::ELF32LE>( 590 (*ELFObj)->getFileName(), ELFObjFile.getELFFile(), 591 (*ELFObj)->makeTriple()) 592 .buildGraph(); 593 } 594 } 595 596 void link_ELF_riscv(std::unique_ptr<LinkGraph> G, 597 std::unique_ptr<JITLinkContext> Ctx) { 598 PassConfiguration Config; 599 const Triple &TT = G->getTargetTriple(); 600 if (Ctx->shouldAddDefaultTargetPasses(TT)) { 601 if (auto MarkLive = Ctx->getMarkLivePass(TT)) 602 Config.PrePrunePasses.push_back(std::move(MarkLive)); 603 else 604 Config.PrePrunePasses.push_back(markAllSymbolsLive); 605 Config.PostPrunePasses.push_back( 606 PerGraphGOTAndPLTStubsBuilder_ELF_riscv::asPass); 607 } 608 if (auto Err = Ctx->modifyPassConfig(*G, Config)) 609 return Ctx->notifyFailed(std::move(Err)); 610 611 ELFJITLinker_riscv::link(std::move(Ctx), std::move(G), std::move(Config)); 612 } 613 614 } // namespace jitlink 615 } // namespace llvm 616