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 Imm12 = extractBits(Value, 12, 1) << 31; 209 uint32_t Imm10_5 = extractBits(Value, 5, 6) << 25; 210 uint32_t Imm4_1 = extractBits(Value, 1, 4) << 8; 211 uint32_t Imm11 = extractBits(Value, 11, 1) << 7; 212 uint32_t RawInstr = *(little32_t *)FixupPtr; 213 *(little32_t *)FixupPtr = 214 (RawInstr & 0x1FFF07F) | Imm12 | Imm10_5 | Imm4_1 | Imm11; 215 break; 216 } 217 case R_RISCV_JAL: { 218 int64_t Value = E.getTarget().getAddress() + E.getAddend() - FixupAddress; 219 if (LLVM_UNLIKELY(!isInRangeForImm(Value >> 1, 20))) 220 return makeTargetOutOfRangeError(G, B, E); 221 if (LLVM_UNLIKELY(!isAlignmentCorrect(Value, 2))) 222 return makeAlignmentError(FixupAddress, Value, 2, E); 223 uint32_t Imm20 = extractBits(Value, 20, 1) << 31; 224 uint32_t Imm10_1 = extractBits(Value, 1, 10) << 21; 225 uint32_t Imm11 = extractBits(Value, 11, 1) << 20; 226 uint32_t Imm19_12 = extractBits(Value, 12, 8) << 12; 227 uint32_t RawInstr = *(little32_t *)FixupPtr; 228 *(little32_t *)FixupPtr = 229 (RawInstr & 0xFFF) | Imm20 | Imm10_1 | Imm11 | Imm19_12; 230 break; 231 } 232 case R_RISCV_CALL: { 233 int64_t Value = E.getTarget().getAddress() + E.getAddend() - FixupAddress; 234 int64_t Hi = Value + 0x800; 235 if (LLVM_UNLIKELY(!isInRangeForImm(Hi, 32))) 236 return makeTargetOutOfRangeError(G, B, E); 237 int32_t Lo = Value & 0xFFF; 238 uint32_t RawInstrAuipc = *(little32_t *)FixupPtr; 239 uint32_t RawInstrJalr = *(little32_t *)(FixupPtr + 4); 240 *(little32_t *)FixupPtr = 241 RawInstrAuipc | (static_cast<uint32_t>(Hi & 0xFFFFF000)); 242 *(little32_t *)(FixupPtr + 4) = 243 RawInstrJalr | (static_cast<uint32_t>(Lo) << 20); 244 break; 245 } 246 // The relocations R_RISCV_CALL_PLT and R_RISCV_GOT_HI20 are handled by 247 // PerGraphGOTAndPLTStubsBuilder_ELF_riscv and are transformed into 248 // R_RISCV_CALL and R_RISCV_PCREL_HI20. 249 case R_RISCV_PCREL_HI20: { 250 int64_t Value = E.getTarget().getAddress() + E.getAddend() - FixupAddress; 251 int64_t Hi = Value + 0x800; 252 if (LLVM_UNLIKELY(!isInRangeForImm(Hi, 32))) 253 return makeTargetOutOfRangeError(G, B, E); 254 uint32_t RawInstr = *(little32_t *)FixupPtr; 255 *(little32_t *)FixupPtr = 256 (RawInstr & 0xFFF) | (static_cast<uint32_t>(Hi & 0xFFFFF000)); 257 break; 258 } 259 case R_RISCV_PCREL_LO12_I: { 260 // FIXME: We assume that R_RISCV_PCREL_HI20 is present in object code and 261 // pairs with current relocation R_RISCV_PCREL_LO12_I. So here may need a 262 // check. 263 auto RelHI20 = getRISCVPCRelHi20(E); 264 if (!RelHI20) 265 return RelHI20.takeError(); 266 int64_t Value = RelHI20->getTarget().getAddress() + 267 RelHI20->getAddend() - E.getTarget().getAddress(); 268 int64_t Lo = Value & 0xFFF; 269 uint32_t RawInstr = *(little32_t *)FixupPtr; 270 *(little32_t *)FixupPtr = 271 (RawInstr & 0xFFFFF) | (static_cast<uint32_t>(Lo & 0xFFF) << 20); 272 break; 273 } 274 case R_RISCV_PCREL_LO12_S: { 275 // FIXME: We assume that R_RISCV_PCREL_HI20 is present in object code and 276 // pairs with current relocation R_RISCV_PCREL_LO12_S. So here may need a 277 // check. 278 auto RelHI20 = getRISCVPCRelHi20(E); 279 if (!RelHI20) 280 return RelHI20.takeError(); 281 int64_t Value = RelHI20->getTarget().getAddress() + 282 RelHI20->getAddend() - E.getTarget().getAddress(); 283 int64_t Lo = Value & 0xFFF; 284 uint32_t Imm11_5 = extractBits(Lo, 5, 7) << 25; 285 uint32_t Imm4_0 = extractBits(Lo, 0, 5) << 7; 286 uint32_t RawInstr = *(little32_t *)FixupPtr; 287 288 *(little32_t *)FixupPtr = (RawInstr & 0x1FFF07F) | Imm11_5 | Imm4_0; 289 break; 290 } 291 case R_RISCV_HI20: { 292 int64_t Value = (E.getTarget().getAddress() + E.getAddend()).getValue(); 293 int64_t Hi = Value + 0x800; 294 if (LLVM_UNLIKELY(!isInRangeForImm(Hi, 32))) 295 return makeTargetOutOfRangeError(G, B, E); 296 uint32_t RawInstr = *(little32_t *)FixupPtr; 297 *(little32_t *)FixupPtr = 298 (RawInstr & 0xFFF) | (static_cast<uint32_t>(Hi & 0xFFFFF000)); 299 break; 300 } 301 case R_RISCV_LO12_I: { 302 // FIXME: We assume that R_RISCV_HI20 is present in object code and pairs 303 // with current relocation R_RISCV_LO12_I. So here may need a check. 304 int64_t Value = (E.getTarget().getAddress() + E.getAddend()).getValue(); 305 int32_t Lo = Value & 0xFFF; 306 uint32_t RawInstr = *(little32_t *)FixupPtr; 307 *(little32_t *)FixupPtr = 308 (RawInstr & 0xFFFFF) | (static_cast<uint32_t>(Lo & 0xFFF) << 20); 309 break; 310 } 311 case R_RISCV_LO12_S: { 312 // FIXME: We assume that R_RISCV_HI20 is present in object code and pairs 313 // with current relocation R_RISCV_LO12_S. So here may need a check. 314 int64_t Value = (E.getTarget().getAddress() + E.getAddend()).getValue(); 315 int64_t Lo = Value & 0xFFF; 316 uint32_t Imm11_5 = extractBits(Lo, 5, 7) << 25; 317 uint32_t Imm4_0 = extractBits(Lo, 0, 5) << 7; 318 uint32_t RawInstr = *(little32_t *)FixupPtr; 319 *(little32_t *)FixupPtr = (RawInstr & 0x1FFF07F) | Imm11_5 | Imm4_0; 320 break; 321 } 322 case R_RISCV_ADD8: { 323 int64_t Value = 324 (E.getTarget().getAddress() + 325 *(reinterpret_cast<const uint8_t *>(FixupAddress.getValue())) + 326 E.getAddend()) 327 .getValue(); 328 *FixupPtr = static_cast<uint8_t>(Value); 329 break; 330 } 331 case R_RISCV_ADD16: { 332 int64_t Value = (E.getTarget().getAddress() + 333 support::endian::read16le(reinterpret_cast<const void *>( 334 FixupAddress.getValue())) + 335 E.getAddend()) 336 .getValue(); 337 *(little16_t *)FixupPtr = static_cast<uint16_t>(Value); 338 break; 339 } 340 case R_RISCV_ADD32: { 341 int64_t Value = (E.getTarget().getAddress() + 342 support::endian::read32le(reinterpret_cast<const void *>( 343 FixupAddress.getValue())) + 344 E.getAddend()) 345 .getValue(); 346 *(little32_t *)FixupPtr = static_cast<uint32_t>(Value); 347 break; 348 } 349 case R_RISCV_ADD64: { 350 int64_t Value = (E.getTarget().getAddress() + 351 support::endian::read64le(reinterpret_cast<const void *>( 352 FixupAddress.getValue())) + 353 E.getAddend()) 354 .getValue(); 355 *(little64_t *)FixupPtr = static_cast<uint64_t>(Value); 356 break; 357 } 358 case R_RISCV_SUB8: { 359 int64_t Value = 360 *(reinterpret_cast<const uint8_t *>(FixupAddress.getValue())) - 361 E.getTarget().getAddress().getValue() - E.getAddend(); 362 *FixupPtr = static_cast<uint8_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_SUB32: { 373 int64_t Value = support::endian::read32le(reinterpret_cast<const void *>( 374 FixupAddress.getValue())) - 375 E.getTarget().getAddress().getValue() - E.getAddend(); 376 *(little32_t *)FixupPtr = static_cast<uint32_t>(Value); 377 break; 378 } 379 case R_RISCV_SUB64: { 380 int64_t Value = support::endian::read64le(reinterpret_cast<const void *>( 381 FixupAddress.getValue())) - 382 E.getTarget().getAddress().getValue() - E.getAddend(); 383 *(little64_t *)FixupPtr = static_cast<uint64_t>(Value); 384 break; 385 } 386 case R_RISCV_SUB6: { 387 int64_t Value = 388 *(reinterpret_cast<const uint8_t *>(FixupAddress.getValue())) & 0x3f; 389 Value -= E.getTarget().getAddress().getValue() - E.getAddend(); 390 *FixupPtr = (*FixupPtr & 0xc0) | (static_cast<uint8_t>(Value) & 0x3f); 391 break; 392 } 393 case R_RISCV_SET6: { 394 int64_t Value = (E.getTarget().getAddress() + E.getAddend()).getValue(); 395 uint32_t RawData = *(little32_t *)FixupPtr; 396 int64_t Word6 = Value & 0x3f; 397 *(little32_t *)FixupPtr = (RawData & 0xffffffc0) | Word6; 398 break; 399 } 400 case R_RISCV_SET8: { 401 int64_t Value = (E.getTarget().getAddress() + E.getAddend()).getValue(); 402 uint32_t RawData = *(little32_t *)FixupPtr; 403 int64_t Word8 = Value & 0xff; 404 *(little32_t *)FixupPtr = (RawData & 0xffffff00) | Word8; 405 break; 406 } 407 case R_RISCV_SET16: { 408 int64_t Value = (E.getTarget().getAddress() + E.getAddend()).getValue(); 409 uint32_t RawData = *(little32_t *)FixupPtr; 410 int64_t Word16 = Value & 0xffff; 411 *(little32_t *)FixupPtr = (RawData & 0xffff0000) | Word16; 412 break; 413 } 414 case R_RISCV_SET32: { 415 int64_t Value = (E.getTarget().getAddress() + E.getAddend()).getValue(); 416 int64_t Word32 = Value & 0xffffffff; 417 *(little32_t *)FixupPtr = Word32; 418 break; 419 } 420 case R_RISCV_32_PCREL: { 421 int64_t Value = E.getTarget().getAddress() + E.getAddend() - FixupAddress; 422 int64_t Word32 = Value & 0xffffffff; 423 *(little32_t *)FixupPtr = Word32; 424 break; 425 } 426 } 427 return Error::success(); 428 } 429 }; 430 431 template <typename ELFT> 432 class ELFLinkGraphBuilder_riscv : public ELFLinkGraphBuilder<ELFT> { 433 private: 434 static Expected<riscv::EdgeKind_riscv> 435 getRelocationKind(const uint32_t Type) { 436 using namespace riscv; 437 switch (Type) { 438 case ELF::R_RISCV_32: 439 return EdgeKind_riscv::R_RISCV_32; 440 case ELF::R_RISCV_64: 441 return EdgeKind_riscv::R_RISCV_64; 442 case ELF::R_RISCV_BRANCH: 443 return EdgeKind_riscv::R_RISCV_BRANCH; 444 case ELF::R_RISCV_JAL: 445 return EdgeKind_riscv::R_RISCV_JAL; 446 case ELF::R_RISCV_CALL: 447 return EdgeKind_riscv::R_RISCV_CALL; 448 case ELF::R_RISCV_CALL_PLT: 449 return EdgeKind_riscv::R_RISCV_CALL_PLT; 450 case ELF::R_RISCV_GOT_HI20: 451 return EdgeKind_riscv::R_RISCV_GOT_HI20; 452 case ELF::R_RISCV_PCREL_HI20: 453 return EdgeKind_riscv::R_RISCV_PCREL_HI20; 454 case ELF::R_RISCV_PCREL_LO12_I: 455 return EdgeKind_riscv::R_RISCV_PCREL_LO12_I; 456 case ELF::R_RISCV_PCREL_LO12_S: 457 return EdgeKind_riscv::R_RISCV_PCREL_LO12_S; 458 case ELF::R_RISCV_HI20: 459 return EdgeKind_riscv::R_RISCV_HI20; 460 case ELF::R_RISCV_LO12_I: 461 return EdgeKind_riscv::R_RISCV_LO12_I; 462 case ELF::R_RISCV_LO12_S: 463 return EdgeKind_riscv::R_RISCV_LO12_S; 464 case ELF::R_RISCV_ADD8: 465 return EdgeKind_riscv::R_RISCV_ADD8; 466 case ELF::R_RISCV_ADD16: 467 return EdgeKind_riscv::R_RISCV_ADD16; 468 case ELF::R_RISCV_ADD32: 469 return EdgeKind_riscv::R_RISCV_ADD32; 470 case ELF::R_RISCV_ADD64: 471 return EdgeKind_riscv::R_RISCV_ADD64; 472 case ELF::R_RISCV_SUB8: 473 return EdgeKind_riscv::R_RISCV_SUB8; 474 case ELF::R_RISCV_SUB16: 475 return EdgeKind_riscv::R_RISCV_SUB16; 476 case ELF::R_RISCV_SUB32: 477 return EdgeKind_riscv::R_RISCV_SUB32; 478 case ELF::R_RISCV_SUB64: 479 return EdgeKind_riscv::R_RISCV_SUB64; 480 case ELF::R_RISCV_SUB6: 481 return EdgeKind_riscv::R_RISCV_SUB6; 482 case ELF::R_RISCV_SET6: 483 return EdgeKind_riscv::R_RISCV_SET6; 484 case ELF::R_RISCV_SET8: 485 return EdgeKind_riscv::R_RISCV_SET8; 486 case ELF::R_RISCV_SET16: 487 return EdgeKind_riscv::R_RISCV_SET16; 488 case ELF::R_RISCV_SET32: 489 return EdgeKind_riscv::R_RISCV_SET32; 490 case ELF::R_RISCV_32_PCREL: 491 return EdgeKind_riscv::R_RISCV_32_PCREL; 492 } 493 494 return make_error<JITLinkError>( 495 "Unsupported riscv relocation:" + formatv("{0:d}: ", Type) + 496 object::getELFRelocationTypeName(ELF::EM_RISCV, Type)); 497 } 498 499 Error addRelocations() override { 500 LLVM_DEBUG(dbgs() << "Processing relocations:\n"); 501 502 using Base = ELFLinkGraphBuilder<ELFT>; 503 using Self = ELFLinkGraphBuilder_riscv<ELFT>; 504 for (const auto &RelSect : Base::Sections) 505 if (Error Err = Base::forEachRelaRelocation(RelSect, this, 506 &Self::addSingleRelocation)) 507 return Err; 508 509 return Error::success(); 510 } 511 512 Error addSingleRelocation(const typename ELFT::Rela &Rel, 513 const typename ELFT::Shdr &FixupSect, 514 Block &BlockToFix) { 515 using Base = ELFLinkGraphBuilder<ELFT>; 516 517 uint32_t Type = Rel.getType(false); 518 // We do not implement linker relaxation, except what is required for 519 // alignment (see below). 520 if (Type == llvm::ELF::R_RISCV_RELAX) 521 return Error::success(); 522 523 int64_t Addend = Rel.r_addend; 524 if (Type == llvm::ELF::R_RISCV_ALIGN) { 525 uint64_t Alignment = PowerOf2Ceil(Addend); 526 // FIXME: Implement support for ensuring alignment together with linker 527 // relaxation; 2 bytes are guaranteed by the length of compressed 528 // instructions, so this does not need any action from our side. 529 if (Alignment > 2) 530 return make_error<JITLinkError>( 531 formatv("Unsupported relocation R_RISCV_ALIGN with alignment {0} " 532 "larger than 2 (addend: {1})", 533 Alignment, Addend)); 534 return Error::success(); 535 } 536 537 Expected<riscv::EdgeKind_riscv> Kind = getRelocationKind(Type); 538 if (!Kind) 539 return Kind.takeError(); 540 541 uint32_t SymbolIndex = Rel.getSymbol(false); 542 auto ObjSymbol = Base::Obj.getRelocationSymbol(Rel, Base::SymTabSec); 543 if (!ObjSymbol) 544 return ObjSymbol.takeError(); 545 546 Symbol *GraphSymbol = Base::getGraphSymbol(SymbolIndex); 547 if (!GraphSymbol) 548 return make_error<StringError>( 549 formatv("Could not find symbol at given index, did you add it to " 550 "JITSymbolTable? index: {0}, shndx: {1} Size of table: {2}", 551 SymbolIndex, (*ObjSymbol)->st_shndx, 552 Base::GraphSymbols.size()), 553 inconvertibleErrorCode()); 554 555 auto FixupAddress = orc::ExecutorAddr(FixupSect.sh_addr) + Rel.r_offset; 556 Edge::OffsetT Offset = FixupAddress - BlockToFix.getAddress(); 557 Edge GE(*Kind, Offset, *GraphSymbol, Addend); 558 LLVM_DEBUG({ 559 dbgs() << " "; 560 printEdge(dbgs(), BlockToFix, GE, riscv::getEdgeKindName(*Kind)); 561 dbgs() << "\n"; 562 }); 563 564 BlockToFix.addEdge(std::move(GE)); 565 return Error::success(); 566 } 567 568 public: 569 ELFLinkGraphBuilder_riscv(StringRef FileName, 570 const object::ELFFile<ELFT> &Obj, const Triple T) 571 : ELFLinkGraphBuilder<ELFT>(Obj, std::move(T), FileName, 572 riscv::getEdgeKindName) {} 573 }; 574 575 Expected<std::unique_ptr<LinkGraph>> 576 createLinkGraphFromELFObject_riscv(MemoryBufferRef ObjectBuffer) { 577 LLVM_DEBUG({ 578 dbgs() << "Building jitlink graph for new input " 579 << ObjectBuffer.getBufferIdentifier() << "...\n"; 580 }); 581 582 auto ELFObj = object::ObjectFile::createELFObjectFile(ObjectBuffer); 583 if (!ELFObj) 584 return ELFObj.takeError(); 585 586 if ((*ELFObj)->getArch() == Triple::riscv64) { 587 auto &ELFObjFile = cast<object::ELFObjectFile<object::ELF64LE>>(**ELFObj); 588 return ELFLinkGraphBuilder_riscv<object::ELF64LE>( 589 (*ELFObj)->getFileName(), ELFObjFile.getELFFile(), 590 (*ELFObj)->makeTriple()) 591 .buildGraph(); 592 } else { 593 assert((*ELFObj)->getArch() == Triple::riscv32 && 594 "Invalid triple for RISCV ELF object file"); 595 auto &ELFObjFile = cast<object::ELFObjectFile<object::ELF32LE>>(**ELFObj); 596 return ELFLinkGraphBuilder_riscv<object::ELF32LE>( 597 (*ELFObj)->getFileName(), ELFObjFile.getELFFile(), 598 (*ELFObj)->makeTriple()) 599 .buildGraph(); 600 } 601 } 602 603 void link_ELF_riscv(std::unique_ptr<LinkGraph> G, 604 std::unique_ptr<JITLinkContext> Ctx) { 605 PassConfiguration Config; 606 const Triple &TT = G->getTargetTriple(); 607 if (Ctx->shouldAddDefaultTargetPasses(TT)) { 608 if (auto MarkLive = Ctx->getMarkLivePass(TT)) 609 Config.PrePrunePasses.push_back(std::move(MarkLive)); 610 else 611 Config.PrePrunePasses.push_back(markAllSymbolsLive); 612 Config.PostPrunePasses.push_back( 613 PerGraphGOTAndPLTStubsBuilder_ELF_riscv::asPass); 614 } 615 if (auto Err = Ctx->modifyPassConfig(*G, Config)) 616 return Ctx->notifyFailed(std::move(Err)); 617 618 ELFJITLinker_riscv::link(std::move(Ctx), std::move(G), std::move(Config)); 619 } 620 621 } // namespace jitlink 622 } // namespace llvm 623