1//===-- RuntimeDyldELF.cpp - Run-time dynamic linker for MC-JIT -*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// Implementation of ELF support for the MC-JIT runtime dynamic linker. 11// 12//===----------------------------------------------------------------------===// 13 14#include "RuntimeDyldELF.h" 15#include "RuntimeDyldCheckerImpl.h" 16#include "llvm/ADT/IntervalMap.h" 17#include "llvm/ADT/STLExtras.h" 18#include "llvm/ADT/StringRef.h" 19#include "llvm/ADT/Triple.h" 20#include "llvm/MC/MCStreamer.h" 21#include "llvm/Object/ELFObjectFile.h" 22#include "llvm/Object/ObjectFile.h" 23#include "llvm/Support/ELF.h" 24#include "llvm/Support/Endian.h" 25#include "llvm/Support/MemoryBuffer.h" 26#include "llvm/Support/TargetRegistry.h" 27 28using namespace llvm; 29using namespace llvm::object; 30 31#define DEBUG_TYPE "dyld" 32 33namespace { 34 35template <class ELFT> class DyldELFObject : public ELFObjectFile<ELFT> { 36 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) 37 38 typedef Elf_Shdr_Impl<ELFT> Elf_Shdr; 39 typedef Elf_Sym_Impl<ELFT> Elf_Sym; 40 typedef Elf_Rel_Impl<ELFT, false> Elf_Rel; 41 typedef Elf_Rel_Impl<ELFT, true> Elf_Rela; 42 43 typedef Elf_Ehdr_Impl<ELFT> Elf_Ehdr; 44 45 typedef typename ELFDataTypeTypedefHelper<ELFT>::value_type addr_type; 46 47public: 48 DyldELFObject(MemoryBufferRef Wrapper, std::error_code &ec); 49 50 void updateSectionAddress(const SectionRef &Sec, uint64_t Addr); 51 52 void updateSymbolAddress(const SymbolRef &SymRef, uint64_t Addr); 53 54 // Methods for type inquiry through isa, cast and dyn_cast 55 static inline bool classof(const Binary *v) { 56 return (isa<ELFObjectFile<ELFT>>(v) && 57 classof(cast<ELFObjectFile<ELFT>>(v))); 58 } 59 static inline bool classof(const ELFObjectFile<ELFT> *v) { 60 return v->isDyldType(); 61 } 62}; 63 64 65 66// The MemoryBuffer passed into this constructor is just a wrapper around the 67// actual memory. Ultimately, the Binary parent class will take ownership of 68// this MemoryBuffer object but not the underlying memory. 69template <class ELFT> 70DyldELFObject<ELFT>::DyldELFObject(MemoryBufferRef Wrapper, std::error_code &EC) 71 : ELFObjectFile<ELFT>(Wrapper, EC) { 72 this->isDyldELFObject = true; 73} 74 75template <class ELFT> 76void DyldELFObject<ELFT>::updateSectionAddress(const SectionRef &Sec, 77 uint64_t Addr) { 78 DataRefImpl ShdrRef = Sec.getRawDataRefImpl(); 79 Elf_Shdr *shdr = 80 const_cast<Elf_Shdr *>(reinterpret_cast<const Elf_Shdr *>(ShdrRef.p)); 81 82 // This assumes the address passed in matches the target address bitness 83 // The template-based type cast handles everything else. 84 shdr->sh_addr = static_cast<addr_type>(Addr); 85} 86 87template <class ELFT> 88void DyldELFObject<ELFT>::updateSymbolAddress(const SymbolRef &SymRef, 89 uint64_t Addr) { 90 91 Elf_Sym *sym = const_cast<Elf_Sym *>( 92 ELFObjectFile<ELFT>::getSymbol(SymRef.getRawDataRefImpl())); 93 94 // This assumes the address passed in matches the target address bitness 95 // The template-based type cast handles everything else. 96 sym->st_value = static_cast<addr_type>(Addr); 97} 98 99class LoadedELFObjectInfo final 100 : public RuntimeDyld::LoadedObjectInfoHelper<LoadedELFObjectInfo> { 101public: 102 LoadedELFObjectInfo(RuntimeDyldImpl &RTDyld, ObjSectionToIDMap ObjSecToIDMap) 103 : LoadedObjectInfoHelper(RTDyld, std::move(ObjSecToIDMap)) {} 104 105 OwningBinary<ObjectFile> 106 getObjectForDebug(const ObjectFile &Obj) const override; 107}; 108 109template <typename ELFT> 110std::unique_ptr<DyldELFObject<ELFT>> 111createRTDyldELFObject(MemoryBufferRef Buffer, 112 const ObjectFile &SourceObject, 113 const LoadedELFObjectInfo &L, 114 std::error_code &ec) { 115 typedef typename ELFFile<ELFT>::Elf_Shdr Elf_Shdr; 116 typedef typename ELFDataTypeTypedefHelper<ELFT>::value_type addr_type; 117 118 std::unique_ptr<DyldELFObject<ELFT>> Obj = 119 llvm::make_unique<DyldELFObject<ELFT>>(Buffer, ec); 120 121 // Iterate over all sections in the object. 122 auto SI = SourceObject.section_begin(); 123 for (const auto &Sec : Obj->sections()) { 124 StringRef SectionName; 125 Sec.getName(SectionName); 126 if (SectionName != "") { 127 DataRefImpl ShdrRef = Sec.getRawDataRefImpl(); 128 Elf_Shdr *shdr = const_cast<Elf_Shdr *>( 129 reinterpret_cast<const Elf_Shdr *>(ShdrRef.p)); 130 131 if (uint64_t SecLoadAddr = L.getSectionLoadAddress(*SI)) { 132 // This assumes that the address passed in matches the target address 133 // bitness. The template-based type cast handles everything else. 134 shdr->sh_addr = static_cast<addr_type>(SecLoadAddr); 135 } 136 } 137 ++SI; 138 } 139 140 return Obj; 141} 142 143OwningBinary<ObjectFile> createELFDebugObject(const ObjectFile &Obj, 144 const LoadedELFObjectInfo &L) { 145 assert(Obj.isELF() && "Not an ELF object file."); 146 147 std::unique_ptr<MemoryBuffer> Buffer = 148 MemoryBuffer::getMemBufferCopy(Obj.getData(), Obj.getFileName()); 149 150 std::error_code ec; 151 152 std::unique_ptr<ObjectFile> DebugObj; 153 if (Obj.getBytesInAddress() == 4 && Obj.isLittleEndian()) { 154 typedef ELFType<support::little, false> ELF32LE; 155 DebugObj = createRTDyldELFObject<ELF32LE>(Buffer->getMemBufferRef(), Obj, L, 156 ec); 157 } else if (Obj.getBytesInAddress() == 4 && !Obj.isLittleEndian()) { 158 typedef ELFType<support::big, false> ELF32BE; 159 DebugObj = createRTDyldELFObject<ELF32BE>(Buffer->getMemBufferRef(), Obj, L, 160 ec); 161 } else if (Obj.getBytesInAddress() == 8 && !Obj.isLittleEndian()) { 162 typedef ELFType<support::big, true> ELF64BE; 163 DebugObj = createRTDyldELFObject<ELF64BE>(Buffer->getMemBufferRef(), Obj, L, 164 ec); 165 } else if (Obj.getBytesInAddress() == 8 && Obj.isLittleEndian()) { 166 typedef ELFType<support::little, true> ELF64LE; 167 DebugObj = createRTDyldELFObject<ELF64LE>(Buffer->getMemBufferRef(), Obj, L, 168 ec); 169 } else 170 llvm_unreachable("Unexpected ELF format"); 171 172 assert(!ec && "Could not construct copy ELF object file"); 173 174 return OwningBinary<ObjectFile>(std::move(DebugObj), std::move(Buffer)); 175} 176 177OwningBinary<ObjectFile> 178LoadedELFObjectInfo::getObjectForDebug(const ObjectFile &Obj) const { 179 return createELFDebugObject(Obj, *this); 180} 181 182} // anonymous namespace 183 184namespace llvm { 185 186RuntimeDyldELF::RuntimeDyldELF(RuntimeDyld::MemoryManager &MemMgr, 187 RuntimeDyld::SymbolResolver &Resolver) 188 : RuntimeDyldImpl(MemMgr, Resolver), GOTSectionID(0), CurrentGOTIndex(0) {} 189RuntimeDyldELF::~RuntimeDyldELF() {} 190 191void RuntimeDyldELF::registerEHFrames() { 192 for (int i = 0, e = UnregisteredEHFrameSections.size(); i != e; ++i) { 193 SID EHFrameSID = UnregisteredEHFrameSections[i]; 194 uint8_t *EHFrameAddr = Sections[EHFrameSID].getAddress(); 195 uint64_t EHFrameLoadAddr = Sections[EHFrameSID].getLoadAddress(); 196 size_t EHFrameSize = Sections[EHFrameSID].getSize(); 197 MemMgr.registerEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize); 198 RegisteredEHFrameSections.push_back(EHFrameSID); 199 } 200 UnregisteredEHFrameSections.clear(); 201} 202 203void RuntimeDyldELF::deregisterEHFrames() { 204 for (int i = 0, e = RegisteredEHFrameSections.size(); i != e; ++i) { 205 SID EHFrameSID = RegisteredEHFrameSections[i]; 206 uint8_t *EHFrameAddr = Sections[EHFrameSID].getAddress(); 207 uint64_t EHFrameLoadAddr = Sections[EHFrameSID].getLoadAddress(); 208 size_t EHFrameSize = Sections[EHFrameSID].getSize(); 209 MemMgr.deregisterEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize); 210 } 211 RegisteredEHFrameSections.clear(); 212} 213 214std::unique_ptr<RuntimeDyld::LoadedObjectInfo> 215RuntimeDyldELF::loadObject(const object::ObjectFile &O) { 216 if (auto ObjSectionToIDOrErr = loadObjectImpl(O)) 217 return llvm::make_unique<LoadedELFObjectInfo>(*this, *ObjSectionToIDOrErr); 218 else { 219 HasError = true; 220 raw_string_ostream ErrStream(ErrorStr); 221 logAllUnhandledErrors(ObjSectionToIDOrErr.takeError(), ErrStream, ""); 222 return nullptr; 223 } 224} 225 226void RuntimeDyldELF::resolveX86_64Relocation(const SectionEntry &Section, 227 uint64_t Offset, uint64_t Value, 228 uint32_t Type, int64_t Addend, 229 uint64_t SymOffset) { 230 switch (Type) { 231 default: 232 llvm_unreachable("Relocation type not implemented yet!"); 233 break; 234 case ELF::R_X86_64_64: { 235 support::ulittle64_t::ref(Section.getAddressWithOffset(Offset)) = 236 Value + Addend; 237 DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend)) << " at " 238 << format("%p\n", Section.getAddressWithOffset(Offset))); 239 break; 240 } 241 case ELF::R_X86_64_32: 242 case ELF::R_X86_64_32S: { 243 Value += Addend; 244 assert((Type == ELF::R_X86_64_32 && (Value <= UINT32_MAX)) || 245 (Type == ELF::R_X86_64_32S && 246 ((int64_t)Value <= INT32_MAX && (int64_t)Value >= INT32_MIN))); 247 uint32_t TruncatedAddr = (Value & 0xFFFFFFFF); 248 support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) = 249 TruncatedAddr; 250 DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr) << " at " 251 << format("%p\n", Section.getAddressWithOffset(Offset))); 252 break; 253 } 254 case ELF::R_X86_64_PC8: { 255 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 256 int64_t RealOffset = Value + Addend - FinalAddress; 257 assert(isInt<8>(RealOffset)); 258 int8_t TruncOffset = (RealOffset & 0xFF); 259 Section.getAddress()[Offset] = TruncOffset; 260 break; 261 } 262 case ELF::R_X86_64_PC32: { 263 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 264 int64_t RealOffset = Value + Addend - FinalAddress; 265 assert(isInt<32>(RealOffset)); 266 int32_t TruncOffset = (RealOffset & 0xFFFFFFFF); 267 support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) = 268 TruncOffset; 269 break; 270 } 271 case ELF::R_X86_64_PC64: { 272 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 273 int64_t RealOffset = Value + Addend - FinalAddress; 274 support::ulittle64_t::ref(Section.getAddressWithOffset(Offset)) = 275 RealOffset; 276 break; 277 } 278 } 279} 280 281void RuntimeDyldELF::resolveX86Relocation(const SectionEntry &Section, 282 uint64_t Offset, uint32_t Value, 283 uint32_t Type, int32_t Addend) { 284 switch (Type) { 285 case ELF::R_386_32: { 286 support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) = 287 Value + Addend; 288 break; 289 } 290 case ELF::R_386_PC32: { 291 uint32_t FinalAddress = 292 Section.getLoadAddressWithOffset(Offset) & 0xFFFFFFFF; 293 uint32_t RealOffset = Value + Addend - FinalAddress; 294 support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) = 295 RealOffset; 296 break; 297 } 298 default: 299 // There are other relocation types, but it appears these are the 300 // only ones currently used by the LLVM ELF object writer 301 llvm_unreachable("Relocation type not implemented yet!"); 302 break; 303 } 304} 305 306void RuntimeDyldELF::resolveAArch64Relocation(const SectionEntry &Section, 307 uint64_t Offset, uint64_t Value, 308 uint32_t Type, int64_t Addend) { 309 uint32_t *TargetPtr = 310 reinterpret_cast<uint32_t *>(Section.getAddressWithOffset(Offset)); 311 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 312 313 DEBUG(dbgs() << "resolveAArch64Relocation, LocalAddress: 0x" 314 << format("%llx", Section.getAddressWithOffset(Offset)) 315 << " FinalAddress: 0x" << format("%llx", FinalAddress) 316 << " Value: 0x" << format("%llx", Value) << " Type: 0x" 317 << format("%x", Type) << " Addend: 0x" << format("%llx", Addend) 318 << "\n"); 319 320 switch (Type) { 321 default: 322 llvm_unreachable("Relocation type not implemented yet!"); 323 break; 324 case ELF::R_AARCH64_ABS64: { 325 uint64_t *TargetPtr = 326 reinterpret_cast<uint64_t *>(Section.getAddressWithOffset(Offset)); 327 *TargetPtr = Value + Addend; 328 break; 329 } 330 case ELF::R_AARCH64_PREL32: { 331 uint64_t Result = Value + Addend - FinalAddress; 332 assert(static_cast<int64_t>(Result) >= INT32_MIN && 333 static_cast<int64_t>(Result) <= UINT32_MAX); 334 *TargetPtr = static_cast<uint32_t>(Result & 0xffffffffU); 335 break; 336 } 337 case ELF::R_AARCH64_CALL26: // fallthrough 338 case ELF::R_AARCH64_JUMP26: { 339 // Operation: S+A-P. Set Call or B immediate value to bits fff_fffc of the 340 // calculation. 341 uint64_t BranchImm = Value + Addend - FinalAddress; 342 343 // "Check that -2^27 <= result < 2^27". 344 assert(isInt<28>(BranchImm)); 345 346 // AArch64 code is emitted with .rela relocations. The data already in any 347 // bits affected by the relocation on entry is garbage. 348 *TargetPtr &= 0xfc000000U; 349 // Immediate goes in bits 25:0 of B and BL. 350 *TargetPtr |= static_cast<uint32_t>(BranchImm & 0xffffffcU) >> 2; 351 break; 352 } 353 case ELF::R_AARCH64_MOVW_UABS_G3: { 354 uint64_t Result = Value + Addend; 355 356 // AArch64 code is emitted with .rela relocations. The data already in any 357 // bits affected by the relocation on entry is garbage. 358 *TargetPtr &= 0xffe0001fU; 359 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction 360 *TargetPtr |= Result >> (48 - 5); 361 // Shift must be "lsl #48", in bits 22:21 362 assert((*TargetPtr >> 21 & 0x3) == 3 && "invalid shift for relocation"); 363 break; 364 } 365 case ELF::R_AARCH64_MOVW_UABS_G2_NC: { 366 uint64_t Result = Value + Addend; 367 368 // AArch64 code is emitted with .rela relocations. The data already in any 369 // bits affected by the relocation on entry is garbage. 370 *TargetPtr &= 0xffe0001fU; 371 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction 372 *TargetPtr |= ((Result & 0xffff00000000ULL) >> (32 - 5)); 373 // Shift must be "lsl #32", in bits 22:21 374 assert((*TargetPtr >> 21 & 0x3) == 2 && "invalid shift for relocation"); 375 break; 376 } 377 case ELF::R_AARCH64_MOVW_UABS_G1_NC: { 378 uint64_t Result = Value + Addend; 379 380 // AArch64 code is emitted with .rela relocations. The data already in any 381 // bits affected by the relocation on entry is garbage. 382 *TargetPtr &= 0xffe0001fU; 383 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction 384 *TargetPtr |= ((Result & 0xffff0000U) >> (16 - 5)); 385 // Shift must be "lsl #16", in bits 22:2 386 assert((*TargetPtr >> 21 & 0x3) == 1 && "invalid shift for relocation"); 387 break; 388 } 389 case ELF::R_AARCH64_MOVW_UABS_G0_NC: { 390 uint64_t Result = Value + Addend; 391 392 // AArch64 code is emitted with .rela relocations. The data already in any 393 // bits affected by the relocation on entry is garbage. 394 *TargetPtr &= 0xffe0001fU; 395 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction 396 *TargetPtr |= ((Result & 0xffffU) << 5); 397 // Shift must be "lsl #0", in bits 22:21. 398 assert((*TargetPtr >> 21 & 0x3) == 0 && "invalid shift for relocation"); 399 break; 400 } 401 case ELF::R_AARCH64_ADR_PREL_PG_HI21: { 402 // Operation: Page(S+A) - Page(P) 403 uint64_t Result = 404 ((Value + Addend) & ~0xfffULL) - (FinalAddress & ~0xfffULL); 405 406 // Check that -2^32 <= X < 2^32 407 assert(isInt<33>(Result) && "overflow check failed for relocation"); 408 409 // AArch64 code is emitted with .rela relocations. The data already in any 410 // bits affected by the relocation on entry is garbage. 411 *TargetPtr &= 0x9f00001fU; 412 // Immediate goes in bits 30:29 + 5:23 of ADRP instruction, taken 413 // from bits 32:12 of X. 414 *TargetPtr |= ((Result & 0x3000U) << (29 - 12)); 415 *TargetPtr |= ((Result & 0x1ffffc000ULL) >> (14 - 5)); 416 break; 417 } 418 case ELF::R_AARCH64_LDST32_ABS_LO12_NC: { 419 // Operation: S + A 420 uint64_t Result = Value + Addend; 421 422 // AArch64 code is emitted with .rela relocations. The data already in any 423 // bits affected by the relocation on entry is garbage. 424 *TargetPtr &= 0xffc003ffU; 425 // Immediate goes in bits 21:10 of LD/ST instruction, taken 426 // from bits 11:2 of X 427 *TargetPtr |= ((Result & 0xffc) << (10 - 2)); 428 break; 429 } 430 case ELF::R_AARCH64_LDST64_ABS_LO12_NC: { 431 // Operation: S + A 432 uint64_t Result = Value + Addend; 433 434 // AArch64 code is emitted with .rela relocations. The data already in any 435 // bits affected by the relocation on entry is garbage. 436 *TargetPtr &= 0xffc003ffU; 437 // Immediate goes in bits 21:10 of LD/ST instruction, taken 438 // from bits 11:3 of X 439 *TargetPtr |= ((Result & 0xff8) << (10 - 3)); 440 break; 441 } 442 } 443} 444 445void RuntimeDyldELF::resolveARMRelocation(const SectionEntry &Section, 446 uint64_t Offset, uint32_t Value, 447 uint32_t Type, int32_t Addend) { 448 // TODO: Add Thumb relocations. 449 uint32_t *TargetPtr = 450 reinterpret_cast<uint32_t *>(Section.getAddressWithOffset(Offset)); 451 uint32_t FinalAddress = Section.getLoadAddressWithOffset(Offset) & 0xFFFFFFFF; 452 Value += Addend; 453 454 DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: " 455 << Section.getAddressWithOffset(Offset) 456 << " FinalAddress: " << format("%p", FinalAddress) << " Value: " 457 << format("%x", Value) << " Type: " << format("%x", Type) 458 << " Addend: " << format("%x", Addend) << "\n"); 459 460 switch (Type) { 461 default: 462 llvm_unreachable("Not implemented relocation type!"); 463 464 case ELF::R_ARM_NONE: 465 break; 466 case ELF::R_ARM_PREL31: 467 case ELF::R_ARM_TARGET1: 468 case ELF::R_ARM_ABS32: 469 *TargetPtr = Value; 470 break; 471 // Write first 16 bit of 32 bit value to the mov instruction. 472 // Last 4 bit should be shifted. 473 case ELF::R_ARM_MOVW_ABS_NC: 474 case ELF::R_ARM_MOVT_ABS: 475 if (Type == ELF::R_ARM_MOVW_ABS_NC) 476 Value = Value & 0xFFFF; 477 else if (Type == ELF::R_ARM_MOVT_ABS) 478 Value = (Value >> 16) & 0xFFFF; 479 *TargetPtr &= ~0x000F0FFF; 480 *TargetPtr |= Value & 0xFFF; 481 *TargetPtr |= ((Value >> 12) & 0xF) << 16; 482 break; 483 // Write 24 bit relative value to the branch instruction. 484 case ELF::R_ARM_PC24: // Fall through. 485 case ELF::R_ARM_CALL: // Fall through. 486 case ELF::R_ARM_JUMP24: 487 int32_t RelValue = static_cast<int32_t>(Value - FinalAddress - 8); 488 RelValue = (RelValue & 0x03FFFFFC) >> 2; 489 assert((*TargetPtr & 0xFFFFFF) == 0xFFFFFE); 490 *TargetPtr &= 0xFF000000; 491 *TargetPtr |= RelValue; 492 break; 493 } 494} 495 496void RuntimeDyldELF::resolveMIPSRelocation(const SectionEntry &Section, 497 uint64_t Offset, uint32_t Value, 498 uint32_t Type, int32_t Addend) { 499 uint8_t *TargetPtr = Section.getAddressWithOffset(Offset); 500 Value += Addend; 501 502 DEBUG(dbgs() << "resolveMIPSRelocation, LocalAddress: " 503 << Section.getAddressWithOffset(Offset) << " FinalAddress: " 504 << format("%p", Section.getLoadAddressWithOffset(Offset)) 505 << " Value: " << format("%x", Value) 506 << " Type: " << format("%x", Type) 507 << " Addend: " << format("%x", Addend) << "\n"); 508 509 uint32_t Insn = readBytesUnaligned(TargetPtr, 4); 510 511 switch (Type) { 512 default: 513 llvm_unreachable("Not implemented relocation type!"); 514 break; 515 case ELF::R_MIPS_32: 516 writeBytesUnaligned(Value, TargetPtr, 4); 517 break; 518 case ELF::R_MIPS_26: 519 Insn &= 0xfc000000; 520 Insn |= (Value & 0x0fffffff) >> 2; 521 writeBytesUnaligned(Insn, TargetPtr, 4); 522 break; 523 case ELF::R_MIPS_HI16: 524 // Get the higher 16-bits. Also add 1 if bit 15 is 1. 525 Insn &= 0xffff0000; 526 Insn |= ((Value + 0x8000) >> 16) & 0xffff; 527 writeBytesUnaligned(Insn, TargetPtr, 4); 528 break; 529 case ELF::R_MIPS_LO16: 530 Insn &= 0xffff0000; 531 Insn |= Value & 0xffff; 532 writeBytesUnaligned(Insn, TargetPtr, 4); 533 break; 534 case ELF::R_MIPS_PC32: { 535 uint32_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 536 writeBytesUnaligned(Value - FinalAddress, (uint8_t *)TargetPtr, 4); 537 break; 538 } 539 case ELF::R_MIPS_PC16: { 540 uint32_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 541 Insn &= 0xffff0000; 542 Insn |= ((Value - FinalAddress) >> 2) & 0xffff; 543 writeBytesUnaligned(Insn, TargetPtr, 4); 544 break; 545 } 546 case ELF::R_MIPS_PC19_S2: { 547 uint32_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 548 Insn &= 0xfff80000; 549 Insn |= ((Value - (FinalAddress & ~0x3)) >> 2) & 0x7ffff; 550 writeBytesUnaligned(Insn, TargetPtr, 4); 551 break; 552 } 553 case ELF::R_MIPS_PC21_S2: { 554 uint32_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 555 Insn &= 0xffe00000; 556 Insn |= ((Value - FinalAddress) >> 2) & 0x1fffff; 557 writeBytesUnaligned(Insn, TargetPtr, 4); 558 break; 559 } 560 case ELF::R_MIPS_PC26_S2: { 561 uint32_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 562 Insn &= 0xfc000000; 563 Insn |= ((Value - FinalAddress) >> 2) & 0x3ffffff; 564 writeBytesUnaligned(Insn, TargetPtr, 4); 565 break; 566 } 567 case ELF::R_MIPS_PCHI16: { 568 uint32_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 569 Insn &= 0xffff0000; 570 Insn |= ((Value - FinalAddress + 0x8000) >> 16) & 0xffff; 571 writeBytesUnaligned(Insn, TargetPtr, 4); 572 break; 573 } 574 case ELF::R_MIPS_PCLO16: { 575 uint32_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 576 Insn &= 0xffff0000; 577 Insn |= (Value - FinalAddress) & 0xffff; 578 writeBytesUnaligned(Insn, TargetPtr, 4); 579 break; 580 } 581 } 582} 583 584void RuntimeDyldELF::setMipsABI(const ObjectFile &Obj) { 585 if (Arch == Triple::UnknownArch || 586 !StringRef(Triple::getArchTypePrefix(Arch)).equals("mips")) { 587 IsMipsO32ABI = false; 588 IsMipsN64ABI = false; 589 return; 590 } 591 unsigned AbiVariant; 592 Obj.getPlatformFlags(AbiVariant); 593 IsMipsO32ABI = AbiVariant & ELF::EF_MIPS_ABI_O32; 594 IsMipsN64ABI = Obj.getFileFormatName().equals("ELF64-mips"); 595 if (AbiVariant & ELF::EF_MIPS_ABI2) 596 llvm_unreachable("Mips N32 ABI is not supported yet"); 597} 598 599void RuntimeDyldELF::resolveMIPS64Relocation(const SectionEntry &Section, 600 uint64_t Offset, uint64_t Value, 601 uint32_t Type, int64_t Addend, 602 uint64_t SymOffset, 603 SID SectionID) { 604 uint32_t r_type = Type & 0xff; 605 uint32_t r_type2 = (Type >> 8) & 0xff; 606 uint32_t r_type3 = (Type >> 16) & 0xff; 607 608 // RelType is used to keep information for which relocation type we are 609 // applying relocation. 610 uint32_t RelType = r_type; 611 int64_t CalculatedValue = evaluateMIPS64Relocation(Section, Offset, Value, 612 RelType, Addend, 613 SymOffset, SectionID); 614 if (r_type2 != ELF::R_MIPS_NONE) { 615 RelType = r_type2; 616 CalculatedValue = evaluateMIPS64Relocation(Section, Offset, 0, RelType, 617 CalculatedValue, SymOffset, 618 SectionID); 619 } 620 if (r_type3 != ELF::R_MIPS_NONE) { 621 RelType = r_type3; 622 CalculatedValue = evaluateMIPS64Relocation(Section, Offset, 0, RelType, 623 CalculatedValue, SymOffset, 624 SectionID); 625 } 626 applyMIPS64Relocation(Section.getAddressWithOffset(Offset), CalculatedValue, 627 RelType); 628} 629 630int64_t 631RuntimeDyldELF::evaluateMIPS64Relocation(const SectionEntry &Section, 632 uint64_t Offset, uint64_t Value, 633 uint32_t Type, int64_t Addend, 634 uint64_t SymOffset, SID SectionID) { 635 636 DEBUG(dbgs() << "evaluateMIPS64Relocation, LocalAddress: 0x" 637 << format("%llx", Section.getAddressWithOffset(Offset)) 638 << " FinalAddress: 0x" 639 << format("%llx", Section.getLoadAddressWithOffset(Offset)) 640 << " Value: 0x" << format("%llx", Value) << " Type: 0x" 641 << format("%x", Type) << " Addend: 0x" << format("%llx", Addend) 642 << " SymOffset: " << format("%x", SymOffset) << "\n"); 643 644 switch (Type) { 645 default: 646 llvm_unreachable("Not implemented relocation type!"); 647 break; 648 case ELF::R_MIPS_JALR: 649 case ELF::R_MIPS_NONE: 650 break; 651 case ELF::R_MIPS_32: 652 case ELF::R_MIPS_64: 653 return Value + Addend; 654 case ELF::R_MIPS_26: 655 return ((Value + Addend) >> 2) & 0x3ffffff; 656 case ELF::R_MIPS_GPREL16: { 657 uint64_t GOTAddr = getSectionLoadAddress(SectionToGOTMap[SectionID]); 658 return Value + Addend - (GOTAddr + 0x7ff0); 659 } 660 case ELF::R_MIPS_SUB: 661 return Value - Addend; 662 case ELF::R_MIPS_HI16: 663 // Get the higher 16-bits. Also add 1 if bit 15 is 1. 664 return ((Value + Addend + 0x8000) >> 16) & 0xffff; 665 case ELF::R_MIPS_LO16: 666 return (Value + Addend) & 0xffff; 667 case ELF::R_MIPS_CALL16: 668 case ELF::R_MIPS_GOT_DISP: 669 case ELF::R_MIPS_GOT_PAGE: { 670 uint8_t *LocalGOTAddr = 671 getSectionAddress(SectionToGOTMap[SectionID]) + SymOffset; 672 uint64_t GOTEntry = readBytesUnaligned(LocalGOTAddr, 8); 673 674 Value += Addend; 675 if (Type == ELF::R_MIPS_GOT_PAGE) 676 Value = (Value + 0x8000) & ~0xffff; 677 678 if (GOTEntry) 679 assert(GOTEntry == Value && 680 "GOT entry has two different addresses."); 681 else 682 writeBytesUnaligned(Value, LocalGOTAddr, 8); 683 684 return (SymOffset - 0x7ff0) & 0xffff; 685 } 686 case ELF::R_MIPS_GOT_OFST: { 687 int64_t page = (Value + Addend + 0x8000) & ~0xffff; 688 return (Value + Addend - page) & 0xffff; 689 } 690 case ELF::R_MIPS_GPREL32: { 691 uint64_t GOTAddr = getSectionLoadAddress(SectionToGOTMap[SectionID]); 692 return Value + Addend - (GOTAddr + 0x7ff0); 693 } 694 case ELF::R_MIPS_PC16: { 695 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 696 return ((Value + Addend - FinalAddress) >> 2) & 0xffff; 697 } 698 case ELF::R_MIPS_PC32: { 699 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 700 return Value + Addend - FinalAddress; 701 } 702 case ELF::R_MIPS_PC18_S3: { 703 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 704 return ((Value + Addend - (FinalAddress & ~0x7)) >> 3) & 0x3ffff; 705 } 706 case ELF::R_MIPS_PC19_S2: { 707 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 708 return ((Value + Addend - (FinalAddress & ~0x3)) >> 2) & 0x7ffff; 709 } 710 case ELF::R_MIPS_PC21_S2: { 711 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 712 return ((Value + Addend - FinalAddress) >> 2) & 0x1fffff; 713 } 714 case ELF::R_MIPS_PC26_S2: { 715 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 716 return ((Value + Addend - FinalAddress) >> 2) & 0x3ffffff; 717 } 718 case ELF::R_MIPS_PCHI16: { 719 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 720 return ((Value + Addend - FinalAddress + 0x8000) >> 16) & 0xffff; 721 } 722 case ELF::R_MIPS_PCLO16: { 723 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 724 return (Value + Addend - FinalAddress) & 0xffff; 725 } 726 } 727 return 0; 728} 729 730void RuntimeDyldELF::applyMIPS64Relocation(uint8_t *TargetPtr, 731 int64_t CalculatedValue, 732 uint32_t Type) { 733 uint32_t Insn = readBytesUnaligned(TargetPtr, 4); 734 735 switch (Type) { 736 default: 737 break; 738 case ELF::R_MIPS_32: 739 case ELF::R_MIPS_GPREL32: 740 case ELF::R_MIPS_PC32: 741 writeBytesUnaligned(CalculatedValue & 0xffffffff, TargetPtr, 4); 742 break; 743 case ELF::R_MIPS_64: 744 case ELF::R_MIPS_SUB: 745 writeBytesUnaligned(CalculatedValue, TargetPtr, 8); 746 break; 747 case ELF::R_MIPS_26: 748 case ELF::R_MIPS_PC26_S2: 749 Insn = (Insn & 0xfc000000) | CalculatedValue; 750 writeBytesUnaligned(Insn, TargetPtr, 4); 751 break; 752 case ELF::R_MIPS_GPREL16: 753 Insn = (Insn & 0xffff0000) | (CalculatedValue & 0xffff); 754 writeBytesUnaligned(Insn, TargetPtr, 4); 755 break; 756 case ELF::R_MIPS_HI16: 757 case ELF::R_MIPS_LO16: 758 case ELF::R_MIPS_PCHI16: 759 case ELF::R_MIPS_PCLO16: 760 case ELF::R_MIPS_PC16: 761 case ELF::R_MIPS_CALL16: 762 case ELF::R_MIPS_GOT_DISP: 763 case ELF::R_MIPS_GOT_PAGE: 764 case ELF::R_MIPS_GOT_OFST: 765 Insn = (Insn & 0xffff0000) | CalculatedValue; 766 writeBytesUnaligned(Insn, TargetPtr, 4); 767 break; 768 case ELF::R_MIPS_PC18_S3: 769 Insn = (Insn & 0xfffc0000) | CalculatedValue; 770 writeBytesUnaligned(Insn, TargetPtr, 4); 771 break; 772 case ELF::R_MIPS_PC19_S2: 773 Insn = (Insn & 0xfff80000) | CalculatedValue; 774 writeBytesUnaligned(Insn, TargetPtr, 4); 775 break; 776 case ELF::R_MIPS_PC21_S2: 777 Insn = (Insn & 0xffe00000) | CalculatedValue; 778 writeBytesUnaligned(Insn, TargetPtr, 4); 779 break; 780 } 781} 782 783// Return the .TOC. section and offset. 784Error RuntimeDyldELF::findPPC64TOCSection(const ELFObjectFileBase &Obj, 785 ObjSectionToIDMap &LocalSections, 786 RelocationValueRef &Rel) { 787 // Set a default SectionID in case we do not find a TOC section below. 788 // This may happen for references to TOC base base (sym@toc, .odp 789 // relocation) without a .toc directive. In this case just use the 790 // first section (which is usually the .odp) since the code won't 791 // reference the .toc base directly. 792 Rel.SymbolName = nullptr; 793 Rel.SectionID = 0; 794 795 // The TOC consists of sections .got, .toc, .tocbss, .plt in that 796 // order. The TOC starts where the first of these sections starts. 797 for (auto &Section: Obj.sections()) { 798 StringRef SectionName; 799 if (auto EC = Section.getName(SectionName)) 800 return errorCodeToError(EC); 801 802 if (SectionName == ".got" 803 || SectionName == ".toc" 804 || SectionName == ".tocbss" 805 || SectionName == ".plt") { 806 if (auto SectionIDOrErr = 807 findOrEmitSection(Obj, Section, false, LocalSections)) 808 Rel.SectionID = *SectionIDOrErr; 809 else 810 return SectionIDOrErr.takeError(); 811 break; 812 } 813 } 814 815 // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000 816 // thus permitting a full 64 Kbytes segment. 817 Rel.Addend = 0x8000; 818 819 return Error::success(); 820} 821 822// Returns the sections and offset associated with the ODP entry referenced 823// by Symbol. 824Error RuntimeDyldELF::findOPDEntrySection(const ELFObjectFileBase &Obj, 825 ObjSectionToIDMap &LocalSections, 826 RelocationValueRef &Rel) { 827 // Get the ELF symbol value (st_value) to compare with Relocation offset in 828 // .opd entries 829 for (section_iterator si = Obj.section_begin(), se = Obj.section_end(); 830 si != se; ++si) { 831 section_iterator RelSecI = si->getRelocatedSection(); 832 if (RelSecI == Obj.section_end()) 833 continue; 834 835 StringRef RelSectionName; 836 if (auto EC = RelSecI->getName(RelSectionName)) 837 return errorCodeToError(EC); 838 839 if (RelSectionName != ".opd") 840 continue; 841 842 for (elf_relocation_iterator i = si->relocation_begin(), 843 e = si->relocation_end(); 844 i != e;) { 845 // The R_PPC64_ADDR64 relocation indicates the first field 846 // of a .opd entry 847 uint64_t TypeFunc = i->getType(); 848 if (TypeFunc != ELF::R_PPC64_ADDR64) { 849 ++i; 850 continue; 851 } 852 853 uint64_t TargetSymbolOffset = i->getOffset(); 854 symbol_iterator TargetSymbol = i->getSymbol(); 855 int64_t Addend; 856 if (auto AddendOrErr = i->getAddend()) 857 Addend = *AddendOrErr; 858 else 859 return errorCodeToError(AddendOrErr.getError()); 860 861 ++i; 862 if (i == e) 863 break; 864 865 // Just check if following relocation is a R_PPC64_TOC 866 uint64_t TypeTOC = i->getType(); 867 if (TypeTOC != ELF::R_PPC64_TOC) 868 continue; 869 870 // Finally compares the Symbol value and the target symbol offset 871 // to check if this .opd entry refers to the symbol the relocation 872 // points to. 873 if (Rel.Addend != (int64_t)TargetSymbolOffset) 874 continue; 875 876 section_iterator TSI = Obj.section_end(); 877 if (auto TSIOrErr = TargetSymbol->getSection()) 878 TSI = *TSIOrErr; 879 else 880 return TSIOrErr.takeError(); 881 assert(TSI != Obj.section_end() && "TSI should refer to a valid section"); 882 883 bool IsCode = TSI->isText(); 884 if (auto SectionIDOrErr = findOrEmitSection(Obj, *TSI, IsCode, 885 LocalSections)) 886 Rel.SectionID = *SectionIDOrErr; 887 else 888 return SectionIDOrErr.takeError(); 889 Rel.Addend = (intptr_t)Addend; 890 return Error::success(); 891 } 892 } 893 llvm_unreachable("Attempting to get address of ODP entry!"); 894} 895 896// Relocation masks following the #lo(value), #hi(value), #ha(value), 897// #higher(value), #highera(value), #highest(value), and #highesta(value) 898// macros defined in section 4.5.1. Relocation Types of the PPC-elf64abi 899// document. 900 901static inline uint16_t applyPPClo(uint64_t value) { return value & 0xffff; } 902 903static inline uint16_t applyPPChi(uint64_t value) { 904 return (value >> 16) & 0xffff; 905} 906 907static inline uint16_t applyPPCha (uint64_t value) { 908 return ((value + 0x8000) >> 16) & 0xffff; 909} 910 911static inline uint16_t applyPPChigher(uint64_t value) { 912 return (value >> 32) & 0xffff; 913} 914 915static inline uint16_t applyPPChighera (uint64_t value) { 916 return ((value + 0x8000) >> 32) & 0xffff; 917} 918 919static inline uint16_t applyPPChighest(uint64_t value) { 920 return (value >> 48) & 0xffff; 921} 922 923static inline uint16_t applyPPChighesta (uint64_t value) { 924 return ((value + 0x8000) >> 48) & 0xffff; 925} 926 927void RuntimeDyldELF::resolvePPC32Relocation(const SectionEntry &Section, 928 uint64_t Offset, uint64_t Value, 929 uint32_t Type, int64_t Addend) { 930 uint8_t *LocalAddress = Section.getAddressWithOffset(Offset); 931 switch (Type) { 932 default: 933 llvm_unreachable("Relocation type not implemented yet!"); 934 break; 935 case ELF::R_PPC_ADDR16_LO: 936 writeInt16BE(LocalAddress, applyPPClo(Value + Addend)); 937 break; 938 case ELF::R_PPC_ADDR16_HI: 939 writeInt16BE(LocalAddress, applyPPChi(Value + Addend)); 940 break; 941 case ELF::R_PPC_ADDR16_HA: 942 writeInt16BE(LocalAddress, applyPPCha(Value + Addend)); 943 break; 944 } 945} 946 947void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section, 948 uint64_t Offset, uint64_t Value, 949 uint32_t Type, int64_t Addend) { 950 uint8_t *LocalAddress = Section.getAddressWithOffset(Offset); 951 switch (Type) { 952 default: 953 llvm_unreachable("Relocation type not implemented yet!"); 954 break; 955 case ELF::R_PPC64_ADDR16: 956 writeInt16BE(LocalAddress, applyPPClo(Value + Addend)); 957 break; 958 case ELF::R_PPC64_ADDR16_DS: 959 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3); 960 break; 961 case ELF::R_PPC64_ADDR16_LO: 962 writeInt16BE(LocalAddress, applyPPClo(Value + Addend)); 963 break; 964 case ELF::R_PPC64_ADDR16_LO_DS: 965 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3); 966 break; 967 case ELF::R_PPC64_ADDR16_HI: 968 writeInt16BE(LocalAddress, applyPPChi(Value + Addend)); 969 break; 970 case ELF::R_PPC64_ADDR16_HA: 971 writeInt16BE(LocalAddress, applyPPCha(Value + Addend)); 972 break; 973 case ELF::R_PPC64_ADDR16_HIGHER: 974 writeInt16BE(LocalAddress, applyPPChigher(Value + Addend)); 975 break; 976 case ELF::R_PPC64_ADDR16_HIGHERA: 977 writeInt16BE(LocalAddress, applyPPChighera(Value + Addend)); 978 break; 979 case ELF::R_PPC64_ADDR16_HIGHEST: 980 writeInt16BE(LocalAddress, applyPPChighest(Value + Addend)); 981 break; 982 case ELF::R_PPC64_ADDR16_HIGHESTA: 983 writeInt16BE(LocalAddress, applyPPChighesta(Value + Addend)); 984 break; 985 case ELF::R_PPC64_ADDR14: { 986 assert(((Value + Addend) & 3) == 0); 987 // Preserve the AA/LK bits in the branch instruction 988 uint8_t aalk = *(LocalAddress + 3); 989 writeInt16BE(LocalAddress + 2, (aalk & 3) | ((Value + Addend) & 0xfffc)); 990 } break; 991 case ELF::R_PPC64_REL16_LO: { 992 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 993 uint64_t Delta = Value - FinalAddress + Addend; 994 writeInt16BE(LocalAddress, applyPPClo(Delta)); 995 } break; 996 case ELF::R_PPC64_REL16_HI: { 997 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 998 uint64_t Delta = Value - FinalAddress + Addend; 999 writeInt16BE(LocalAddress, applyPPChi(Delta)); 1000 } break; 1001 case ELF::R_PPC64_REL16_HA: { 1002 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 1003 uint64_t Delta = Value - FinalAddress + Addend; 1004 writeInt16BE(LocalAddress, applyPPCha(Delta)); 1005 } break; 1006 case ELF::R_PPC64_ADDR32: { 1007 int32_t Result = static_cast<int32_t>(Value + Addend); 1008 if (SignExtend32<32>(Result) != Result) 1009 llvm_unreachable("Relocation R_PPC64_ADDR32 overflow"); 1010 writeInt32BE(LocalAddress, Result); 1011 } break; 1012 case ELF::R_PPC64_REL24: { 1013 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 1014 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend); 1015 if (SignExtend32<26>(delta) != delta) 1016 llvm_unreachable("Relocation R_PPC64_REL24 overflow"); 1017 // Generates a 'bl <address>' instruction 1018 writeInt32BE(LocalAddress, 0x48000001 | (delta & 0x03FFFFFC)); 1019 } break; 1020 case ELF::R_PPC64_REL32: { 1021 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 1022 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend); 1023 if (SignExtend32<32>(delta) != delta) 1024 llvm_unreachable("Relocation R_PPC64_REL32 overflow"); 1025 writeInt32BE(LocalAddress, delta); 1026 } break; 1027 case ELF::R_PPC64_REL64: { 1028 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); 1029 uint64_t Delta = Value - FinalAddress + Addend; 1030 writeInt64BE(LocalAddress, Delta); 1031 } break; 1032 case ELF::R_PPC64_ADDR64: 1033 writeInt64BE(LocalAddress, Value + Addend); 1034 break; 1035 } 1036} 1037 1038void RuntimeDyldELF::resolveSystemZRelocation(const SectionEntry &Section, 1039 uint64_t Offset, uint64_t Value, 1040 uint32_t Type, int64_t Addend) { 1041 uint8_t *LocalAddress = Section.getAddressWithOffset(Offset); 1042 switch (Type) { 1043 default: 1044 llvm_unreachable("Relocation type not implemented yet!"); 1045 break; 1046 case ELF::R_390_PC16DBL: 1047 case ELF::R_390_PLT16DBL: { 1048 int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset); 1049 assert(int16_t(Delta / 2) * 2 == Delta && "R_390_PC16DBL overflow"); 1050 writeInt16BE(LocalAddress, Delta / 2); 1051 break; 1052 } 1053 case ELF::R_390_PC32DBL: 1054 case ELF::R_390_PLT32DBL: { 1055 int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset); 1056 assert(int32_t(Delta / 2) * 2 == Delta && "R_390_PC32DBL overflow"); 1057 writeInt32BE(LocalAddress, Delta / 2); 1058 break; 1059 } 1060 case ELF::R_390_PC32: { 1061 int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset); 1062 assert(int32_t(Delta) == Delta && "R_390_PC32 overflow"); 1063 writeInt32BE(LocalAddress, Delta); 1064 break; 1065 } 1066 case ELF::R_390_64: 1067 writeInt64BE(LocalAddress, Value + Addend); 1068 break; 1069 case ELF::R_390_PC64: { 1070 int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset); 1071 writeInt64BE(LocalAddress, Delta); 1072 break; 1073 } 1074 } 1075} 1076 1077// The target location for the relocation is described by RE.SectionID and 1078// RE.Offset. RE.SectionID can be used to find the SectionEntry. Each 1079// SectionEntry has three members describing its location. 1080// SectionEntry::Address is the address at which the section has been loaded 1081// into memory in the current (host) process. SectionEntry::LoadAddress is the 1082// address that the section will have in the target process. 1083// SectionEntry::ObjAddress is the address of the bits for this section in the 1084// original emitted object image (also in the current address space). 1085// 1086// Relocations will be applied as if the section were loaded at 1087// SectionEntry::LoadAddress, but they will be applied at an address based 1088// on SectionEntry::Address. SectionEntry::ObjAddress will be used to refer to 1089// Target memory contents if they are required for value calculations. 1090// 1091// The Value parameter here is the load address of the symbol for the 1092// relocation to be applied. For relocations which refer to symbols in the 1093// current object Value will be the LoadAddress of the section in which 1094// the symbol resides (RE.Addend provides additional information about the 1095// symbol location). For external symbols, Value will be the address of the 1096// symbol in the target address space. 1097void RuntimeDyldELF::resolveRelocation(const RelocationEntry &RE, 1098 uint64_t Value) { 1099 const SectionEntry &Section = Sections[RE.SectionID]; 1100 return resolveRelocation(Section, RE.Offset, Value, RE.RelType, RE.Addend, 1101 RE.SymOffset, RE.SectionID); 1102} 1103 1104void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section, 1105 uint64_t Offset, uint64_t Value, 1106 uint32_t Type, int64_t Addend, 1107 uint64_t SymOffset, SID SectionID) { 1108 switch (Arch) { 1109 case Triple::x86_64: 1110 resolveX86_64Relocation(Section, Offset, Value, Type, Addend, SymOffset); 1111 break; 1112 case Triple::x86: 1113 resolveX86Relocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type, 1114 (uint32_t)(Addend & 0xffffffffL)); 1115 break; 1116 case Triple::aarch64: 1117 case Triple::aarch64_be: 1118 resolveAArch64Relocation(Section, Offset, Value, Type, Addend); 1119 break; 1120 case Triple::arm: // Fall through. 1121 case Triple::armeb: 1122 case Triple::thumb: 1123 case Triple::thumbeb: 1124 resolveARMRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type, 1125 (uint32_t)(Addend & 0xffffffffL)); 1126 break; 1127 case Triple::mips: // Fall through. 1128 case Triple::mipsel: 1129 case Triple::mips64: 1130 case Triple::mips64el: 1131 if (IsMipsO32ABI) 1132 resolveMIPSRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), 1133 Type, (uint32_t)(Addend & 0xffffffffL)); 1134 else if (IsMipsN64ABI) 1135 resolveMIPS64Relocation(Section, Offset, Value, Type, Addend, SymOffset, 1136 SectionID); 1137 else 1138 llvm_unreachable("Mips ABI not handled"); 1139 break; 1140 case Triple::ppc: 1141 resolvePPC32Relocation(Section, Offset, Value, Type, Addend); 1142 break; 1143 case Triple::ppc64: // Fall through. 1144 case Triple::ppc64le: 1145 resolvePPC64Relocation(Section, Offset, Value, Type, Addend); 1146 break; 1147 case Triple::systemz: 1148 resolveSystemZRelocation(Section, Offset, Value, Type, Addend); 1149 break; 1150 default: 1151 llvm_unreachable("Unsupported CPU type!"); 1152 } 1153} 1154 1155void *RuntimeDyldELF::computePlaceholderAddress(unsigned SectionID, uint64_t Offset) const { 1156 return (void *)(Sections[SectionID].getObjAddress() + Offset); 1157} 1158 1159void RuntimeDyldELF::processSimpleRelocation(unsigned SectionID, uint64_t Offset, unsigned RelType, RelocationValueRef Value) { 1160 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend, Value.Offset); 1161 if (Value.SymbolName) 1162 addRelocationForSymbol(RE, Value.SymbolName); 1163 else 1164 addRelocationForSection(RE, Value.SectionID); 1165} 1166 1167uint32_t RuntimeDyldELF::getMatchingLoRelocation(uint32_t RelType, 1168 bool IsLocal) const { 1169 switch (RelType) { 1170 case ELF::R_MICROMIPS_GOT16: 1171 if (IsLocal) 1172 return ELF::R_MICROMIPS_LO16; 1173 break; 1174 case ELF::R_MICROMIPS_HI16: 1175 return ELF::R_MICROMIPS_LO16; 1176 case ELF::R_MIPS_GOT16: 1177 if (IsLocal) 1178 return ELF::R_MIPS_LO16; 1179 break; 1180 case ELF::R_MIPS_HI16: 1181 return ELF::R_MIPS_LO16; 1182 case ELF::R_MIPS_PCHI16: 1183 return ELF::R_MIPS_PCLO16; 1184 default: 1185 break; 1186 } 1187 return ELF::R_MIPS_NONE; 1188} 1189 1190Expected<relocation_iterator> 1191RuntimeDyldELF::processRelocationRef( 1192 unsigned SectionID, relocation_iterator RelI, const ObjectFile &O, 1193 ObjSectionToIDMap &ObjSectionToID, StubMap &Stubs) { 1194 const auto &Obj = cast<ELFObjectFileBase>(O); 1195 uint64_t RelType = RelI->getType(); 1196 ErrorOr<int64_t> AddendOrErr = ELFRelocationRef(*RelI).getAddend(); 1197 int64_t Addend = AddendOrErr ? *AddendOrErr : 0; 1198 elf_symbol_iterator Symbol = RelI->getSymbol(); 1199 1200 // Obtain the symbol name which is referenced in the relocation 1201 StringRef TargetName; 1202 if (Symbol != Obj.symbol_end()) { 1203 if (auto TargetNameOrErr = Symbol->getName()) 1204 TargetName = *TargetNameOrErr; 1205 else 1206 return TargetNameOrErr.takeError(); 1207 } 1208 DEBUG(dbgs() << "\t\tRelType: " << RelType << " Addend: " << Addend 1209 << " TargetName: " << TargetName << "\n"); 1210 RelocationValueRef Value; 1211 // First search for the symbol in the local symbol table 1212 SymbolRef::Type SymType = SymbolRef::ST_Unknown; 1213 1214 // Search for the symbol in the global symbol table 1215 RTDyldSymbolTable::const_iterator gsi = GlobalSymbolTable.end(); 1216 if (Symbol != Obj.symbol_end()) { 1217 gsi = GlobalSymbolTable.find(TargetName.data()); 1218 Expected<SymbolRef::Type> SymTypeOrErr = Symbol->getType(); 1219 if (!SymTypeOrErr) { 1220 std::string Buf; 1221 raw_string_ostream OS(Buf); 1222 logAllUnhandledErrors(SymTypeOrErr.takeError(), OS, ""); 1223 OS.flush(); 1224 report_fatal_error(Buf); 1225 } 1226 SymType = *SymTypeOrErr; 1227 } 1228 if (gsi != GlobalSymbolTable.end()) { 1229 const auto &SymInfo = gsi->second; 1230 Value.SectionID = SymInfo.getSectionID(); 1231 Value.Offset = SymInfo.getOffset(); 1232 Value.Addend = SymInfo.getOffset() + Addend; 1233 } else { 1234 switch (SymType) { 1235 case SymbolRef::ST_Debug: { 1236 // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously 1237 // and can be changed by another developers. Maybe best way is add 1238 // a new symbol type ST_Section to SymbolRef and use it. 1239 auto SectionOrErr = Symbol->getSection(); 1240 if (!SectionOrErr) { 1241 std::string Buf; 1242 raw_string_ostream OS(Buf); 1243 logAllUnhandledErrors(SectionOrErr.takeError(), OS, ""); 1244 OS.flush(); 1245 report_fatal_error(Buf); 1246 } 1247 section_iterator si = *SectionOrErr; 1248 if (si == Obj.section_end()) 1249 llvm_unreachable("Symbol section not found, bad object file format!"); 1250 DEBUG(dbgs() << "\t\tThis is section symbol\n"); 1251 bool isCode = si->isText(); 1252 if (auto SectionIDOrErr = findOrEmitSection(Obj, (*si), isCode, 1253 ObjSectionToID)) 1254 Value.SectionID = *SectionIDOrErr; 1255 else 1256 return SectionIDOrErr.takeError(); 1257 Value.Addend = Addend; 1258 break; 1259 } 1260 case SymbolRef::ST_Data: 1261 case SymbolRef::ST_Unknown: { 1262 Value.SymbolName = TargetName.data(); 1263 Value.Addend = Addend; 1264 1265 // Absolute relocations will have a zero symbol ID (STN_UNDEF), which 1266 // will manifest here as a NULL symbol name. 1267 // We can set this as a valid (but empty) symbol name, and rely 1268 // on addRelocationForSymbol to handle this. 1269 if (!Value.SymbolName) 1270 Value.SymbolName = ""; 1271 break; 1272 } 1273 default: 1274 llvm_unreachable("Unresolved symbol type!"); 1275 break; 1276 } 1277 } 1278 1279 uint64_t Offset = RelI->getOffset(); 1280 1281 DEBUG(dbgs() << "\t\tSectionID: " << SectionID << " Offset: " << Offset 1282 << "\n"); 1283 if ((Arch == Triple::aarch64 || Arch == Triple::aarch64_be) && 1284 (RelType == ELF::R_AARCH64_CALL26 || RelType == ELF::R_AARCH64_JUMP26)) { 1285 // This is an AArch64 branch relocation, need to use a stub function. 1286 DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation."); 1287 SectionEntry &Section = Sections[SectionID]; 1288 1289 // Look for an existing stub. 1290 StubMap::const_iterator i = Stubs.find(Value); 1291 if (i != Stubs.end()) { 1292 resolveRelocation(Section, Offset, 1293 (uint64_t)Section.getAddressWithOffset(i->second), 1294 RelType, 0); 1295 DEBUG(dbgs() << " Stub function found\n"); 1296 } else { 1297 // Create a new stub function. 1298 DEBUG(dbgs() << " Create a new stub function\n"); 1299 Stubs[Value] = Section.getStubOffset(); 1300 uint8_t *StubTargetAddr = createStubFunction( 1301 Section.getAddressWithOffset(Section.getStubOffset())); 1302 1303 RelocationEntry REmovz_g3(SectionID, 1304 StubTargetAddr - Section.getAddress(), 1305 ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend); 1306 RelocationEntry REmovk_g2(SectionID, StubTargetAddr - 1307 Section.getAddress() + 4, 1308 ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend); 1309 RelocationEntry REmovk_g1(SectionID, StubTargetAddr - 1310 Section.getAddress() + 8, 1311 ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend); 1312 RelocationEntry REmovk_g0(SectionID, StubTargetAddr - 1313 Section.getAddress() + 12, 1314 ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend); 1315 1316 if (Value.SymbolName) { 1317 addRelocationForSymbol(REmovz_g3, Value.SymbolName); 1318 addRelocationForSymbol(REmovk_g2, Value.SymbolName); 1319 addRelocationForSymbol(REmovk_g1, Value.SymbolName); 1320 addRelocationForSymbol(REmovk_g0, Value.SymbolName); 1321 } else { 1322 addRelocationForSection(REmovz_g3, Value.SectionID); 1323 addRelocationForSection(REmovk_g2, Value.SectionID); 1324 addRelocationForSection(REmovk_g1, Value.SectionID); 1325 addRelocationForSection(REmovk_g0, Value.SectionID); 1326 } 1327 resolveRelocation(Section, Offset, 1328 reinterpret_cast<uint64_t>(Section.getAddressWithOffset( 1329 Section.getStubOffset())), 1330 RelType, 0); 1331 Section.advanceStubOffset(getMaxStubSize()); 1332 } 1333 } else if (Arch == Triple::arm) { 1334 if (RelType == ELF::R_ARM_PC24 || RelType == ELF::R_ARM_CALL || 1335 RelType == ELF::R_ARM_JUMP24) { 1336 // This is an ARM branch relocation, need to use a stub function. 1337 DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.\n"); 1338 SectionEntry &Section = Sections[SectionID]; 1339 1340 // Look for an existing stub. 1341 StubMap::const_iterator i = Stubs.find(Value); 1342 if (i != Stubs.end()) { 1343 resolveRelocation( 1344 Section, Offset, 1345 reinterpret_cast<uint64_t>(Section.getAddressWithOffset(i->second)), 1346 RelType, 0); 1347 DEBUG(dbgs() << " Stub function found\n"); 1348 } else { 1349 // Create a new stub function. 1350 DEBUG(dbgs() << " Create a new stub function\n"); 1351 Stubs[Value] = Section.getStubOffset(); 1352 uint8_t *StubTargetAddr = createStubFunction( 1353 Section.getAddressWithOffset(Section.getStubOffset())); 1354 RelocationEntry RE(SectionID, StubTargetAddr - Section.getAddress(), 1355 ELF::R_ARM_ABS32, Value.Addend); 1356 if (Value.SymbolName) 1357 addRelocationForSymbol(RE, Value.SymbolName); 1358 else 1359 addRelocationForSection(RE, Value.SectionID); 1360 1361 resolveRelocation(Section, Offset, reinterpret_cast<uint64_t>( 1362 Section.getAddressWithOffset( 1363 Section.getStubOffset())), 1364 RelType, 0); 1365 Section.advanceStubOffset(getMaxStubSize()); 1366 } 1367 } else { 1368 uint32_t *Placeholder = 1369 reinterpret_cast<uint32_t*>(computePlaceholderAddress(SectionID, Offset)); 1370 if (RelType == ELF::R_ARM_PREL31 || RelType == ELF::R_ARM_TARGET1 || 1371 RelType == ELF::R_ARM_ABS32) { 1372 Value.Addend += *Placeholder; 1373 } else if (RelType == ELF::R_ARM_MOVW_ABS_NC || RelType == ELF::R_ARM_MOVT_ABS) { 1374 // See ELF for ARM documentation 1375 Value.Addend += (int16_t)((*Placeholder & 0xFFF) | (((*Placeholder >> 16) & 0xF) << 12)); 1376 } 1377 processSimpleRelocation(SectionID, Offset, RelType, Value); 1378 } 1379 } else if (IsMipsO32ABI) { 1380 uint8_t *Placeholder = reinterpret_cast<uint8_t *>( 1381 computePlaceholderAddress(SectionID, Offset)); 1382 uint32_t Opcode = readBytesUnaligned(Placeholder, 4); 1383 if (RelType == ELF::R_MIPS_26) { 1384 // This is an Mips branch relocation, need to use a stub function. 1385 DEBUG(dbgs() << "\t\tThis is a Mips branch relocation."); 1386 SectionEntry &Section = Sections[SectionID]; 1387 1388 // Extract the addend from the instruction. 1389 // We shift up by two since the Value will be down shifted again 1390 // when applying the relocation. 1391 uint32_t Addend = (Opcode & 0x03ffffff) << 2; 1392 1393 Value.Addend += Addend; 1394 1395 // Look up for existing stub. 1396 StubMap::const_iterator i = Stubs.find(Value); 1397 if (i != Stubs.end()) { 1398 RelocationEntry RE(SectionID, Offset, RelType, i->second); 1399 addRelocationForSection(RE, SectionID); 1400 DEBUG(dbgs() << " Stub function found\n"); 1401 } else { 1402 // Create a new stub function. 1403 DEBUG(dbgs() << " Create a new stub function\n"); 1404 Stubs[Value] = Section.getStubOffset(); 1405 uint8_t *StubTargetAddr = createStubFunction( 1406 Section.getAddressWithOffset(Section.getStubOffset())); 1407 1408 // Creating Hi and Lo relocations for the filled stub instructions. 1409 RelocationEntry REHi(SectionID, StubTargetAddr - Section.getAddress(), 1410 ELF::R_MIPS_HI16, Value.Addend); 1411 RelocationEntry RELo(SectionID, 1412 StubTargetAddr - Section.getAddress() + 4, 1413 ELF::R_MIPS_LO16, Value.Addend); 1414 1415 if (Value.SymbolName) { 1416 addRelocationForSymbol(REHi, Value.SymbolName); 1417 addRelocationForSymbol(RELo, Value.SymbolName); 1418 } 1419 else { 1420 addRelocationForSection(REHi, Value.SectionID); 1421 addRelocationForSection(RELo, Value.SectionID); 1422 } 1423 1424 RelocationEntry RE(SectionID, Offset, RelType, Section.getStubOffset()); 1425 addRelocationForSection(RE, SectionID); 1426 Section.advanceStubOffset(getMaxStubSize()); 1427 } 1428 } else if (RelType == ELF::R_MIPS_HI16 || RelType == ELF::R_MIPS_PCHI16) { 1429 int64_t Addend = (Opcode & 0x0000ffff) << 16; 1430 RelocationEntry RE(SectionID, Offset, RelType, Addend); 1431 PendingRelocs.push_back(std::make_pair(Value, RE)); 1432 } else if (RelType == ELF::R_MIPS_LO16 || RelType == ELF::R_MIPS_PCLO16) { 1433 int64_t Addend = Value.Addend + SignExtend32<16>(Opcode & 0x0000ffff); 1434 for (auto I = PendingRelocs.begin(); I != PendingRelocs.end();) { 1435 const RelocationValueRef &MatchingValue = I->first; 1436 RelocationEntry &Reloc = I->second; 1437 if (MatchingValue == Value && 1438 RelType == getMatchingLoRelocation(Reloc.RelType) && 1439 SectionID == Reloc.SectionID) { 1440 Reloc.Addend += Addend; 1441 if (Value.SymbolName) 1442 addRelocationForSymbol(Reloc, Value.SymbolName); 1443 else 1444 addRelocationForSection(Reloc, Value.SectionID); 1445 I = PendingRelocs.erase(I); 1446 } else 1447 ++I; 1448 } 1449 RelocationEntry RE(SectionID, Offset, RelType, Addend); 1450 if (Value.SymbolName) 1451 addRelocationForSymbol(RE, Value.SymbolName); 1452 else 1453 addRelocationForSection(RE, Value.SectionID); 1454 } else { 1455 if (RelType == ELF::R_MIPS_32) 1456 Value.Addend += Opcode; 1457 else if (RelType == ELF::R_MIPS_PC16) 1458 Value.Addend += SignExtend32<18>((Opcode & 0x0000ffff) << 2); 1459 else if (RelType == ELF::R_MIPS_PC19_S2) 1460 Value.Addend += SignExtend32<21>((Opcode & 0x0007ffff) << 2); 1461 else if (RelType == ELF::R_MIPS_PC21_S2) 1462 Value.Addend += SignExtend32<23>((Opcode & 0x001fffff) << 2); 1463 else if (RelType == ELF::R_MIPS_PC26_S2) 1464 Value.Addend += SignExtend32<28>((Opcode & 0x03ffffff) << 2); 1465 processSimpleRelocation(SectionID, Offset, RelType, Value); 1466 } 1467 } else if (IsMipsN64ABI) { 1468 uint32_t r_type = RelType & 0xff; 1469 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend); 1470 if (r_type == ELF::R_MIPS_CALL16 || r_type == ELF::R_MIPS_GOT_PAGE 1471 || r_type == ELF::R_MIPS_GOT_DISP) { 1472 StringMap<uint64_t>::iterator i = GOTSymbolOffsets.find(TargetName); 1473 if (i != GOTSymbolOffsets.end()) 1474 RE.SymOffset = i->second; 1475 else { 1476 RE.SymOffset = allocateGOTEntries(SectionID, 1); 1477 GOTSymbolOffsets[TargetName] = RE.SymOffset; 1478 } 1479 } 1480 if (Value.SymbolName) 1481 addRelocationForSymbol(RE, Value.SymbolName); 1482 else 1483 addRelocationForSection(RE, Value.SectionID); 1484 } else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) { 1485 if (RelType == ELF::R_PPC64_REL24) { 1486 // Determine ABI variant in use for this object. 1487 unsigned AbiVariant; 1488 Obj.getPlatformFlags(AbiVariant); 1489 AbiVariant &= ELF::EF_PPC64_ABI; 1490 // A PPC branch relocation will need a stub function if the target is 1491 // an external symbol (Symbol::ST_Unknown) or if the target address 1492 // is not within the signed 24-bits branch address. 1493 SectionEntry &Section = Sections[SectionID]; 1494 uint8_t *Target = Section.getAddressWithOffset(Offset); 1495 bool RangeOverflow = false; 1496 if (SymType != SymbolRef::ST_Unknown) { 1497 if (AbiVariant != 2) { 1498 // In the ELFv1 ABI, a function call may point to the .opd entry, 1499 // so the final symbol value is calculated based on the relocation 1500 // values in the .opd section. 1501 if (auto Err = findOPDEntrySection(Obj, ObjSectionToID, Value)) 1502 return std::move(Err); 1503 } else { 1504 // In the ELFv2 ABI, a function symbol may provide a local entry 1505 // point, which must be used for direct calls. 1506 uint8_t SymOther = Symbol->getOther(); 1507 Value.Addend += ELF::decodePPC64LocalEntryOffset(SymOther); 1508 } 1509 uint8_t *RelocTarget = 1510 Sections[Value.SectionID].getAddressWithOffset(Value.Addend); 1511 int32_t delta = static_cast<int32_t>(Target - RelocTarget); 1512 // If it is within 26-bits branch range, just set the branch target 1513 if (SignExtend32<26>(delta) == delta) { 1514 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend); 1515 if (Value.SymbolName) 1516 addRelocationForSymbol(RE, Value.SymbolName); 1517 else 1518 addRelocationForSection(RE, Value.SectionID); 1519 } else { 1520 RangeOverflow = true; 1521 } 1522 } 1523 if (SymType == SymbolRef::ST_Unknown || RangeOverflow) { 1524 // It is an external symbol (SymbolRef::ST_Unknown) or within a range 1525 // larger than 24-bits. 1526 StubMap::const_iterator i = Stubs.find(Value); 1527 if (i != Stubs.end()) { 1528 // Symbol function stub already created, just relocate to it 1529 resolveRelocation(Section, Offset, 1530 reinterpret_cast<uint64_t>( 1531 Section.getAddressWithOffset(i->second)), 1532 RelType, 0); 1533 DEBUG(dbgs() << " Stub function found\n"); 1534 } else { 1535 // Create a new stub function. 1536 DEBUG(dbgs() << " Create a new stub function\n"); 1537 Stubs[Value] = Section.getStubOffset(); 1538 uint8_t *StubTargetAddr = createStubFunction( 1539 Section.getAddressWithOffset(Section.getStubOffset()), 1540 AbiVariant); 1541 RelocationEntry RE(SectionID, StubTargetAddr - Section.getAddress(), 1542 ELF::R_PPC64_ADDR64, Value.Addend); 1543 1544 // Generates the 64-bits address loads as exemplified in section 1545 // 4.5.1 in PPC64 ELF ABI. Note that the relocations need to 1546 // apply to the low part of the instructions, so we have to update 1547 // the offset according to the target endianness. 1548 uint64_t StubRelocOffset = StubTargetAddr - Section.getAddress(); 1549 if (!IsTargetLittleEndian) 1550 StubRelocOffset += 2; 1551 1552 RelocationEntry REhst(SectionID, StubRelocOffset + 0, 1553 ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend); 1554 RelocationEntry REhr(SectionID, StubRelocOffset + 4, 1555 ELF::R_PPC64_ADDR16_HIGHER, Value.Addend); 1556 RelocationEntry REh(SectionID, StubRelocOffset + 12, 1557 ELF::R_PPC64_ADDR16_HI, Value.Addend); 1558 RelocationEntry REl(SectionID, StubRelocOffset + 16, 1559 ELF::R_PPC64_ADDR16_LO, Value.Addend); 1560 1561 if (Value.SymbolName) { 1562 addRelocationForSymbol(REhst, Value.SymbolName); 1563 addRelocationForSymbol(REhr, Value.SymbolName); 1564 addRelocationForSymbol(REh, Value.SymbolName); 1565 addRelocationForSymbol(REl, Value.SymbolName); 1566 } else { 1567 addRelocationForSection(REhst, Value.SectionID); 1568 addRelocationForSection(REhr, Value.SectionID); 1569 addRelocationForSection(REh, Value.SectionID); 1570 addRelocationForSection(REl, Value.SectionID); 1571 } 1572 1573 resolveRelocation(Section, Offset, reinterpret_cast<uint64_t>( 1574 Section.getAddressWithOffset( 1575 Section.getStubOffset())), 1576 RelType, 0); 1577 Section.advanceStubOffset(getMaxStubSize()); 1578 } 1579 if (SymType == SymbolRef::ST_Unknown) { 1580 // Restore the TOC for external calls 1581 if (AbiVariant == 2) 1582 writeInt32BE(Target + 4, 0xE8410018); // ld r2,28(r1) 1583 else 1584 writeInt32BE(Target + 4, 0xE8410028); // ld r2,40(r1) 1585 } 1586 } 1587 } else if (RelType == ELF::R_PPC64_TOC16 || 1588 RelType == ELF::R_PPC64_TOC16_DS || 1589 RelType == ELF::R_PPC64_TOC16_LO || 1590 RelType == ELF::R_PPC64_TOC16_LO_DS || 1591 RelType == ELF::R_PPC64_TOC16_HI || 1592 RelType == ELF::R_PPC64_TOC16_HA) { 1593 // These relocations are supposed to subtract the TOC address from 1594 // the final value. This does not fit cleanly into the RuntimeDyld 1595 // scheme, since there may be *two* sections involved in determining 1596 // the relocation value (the section of the symbol referred to by the 1597 // relocation, and the TOC section associated with the current module). 1598 // 1599 // Fortunately, these relocations are currently only ever generated 1600 // referring to symbols that themselves reside in the TOC, which means 1601 // that the two sections are actually the same. Thus they cancel out 1602 // and we can immediately resolve the relocation right now. 1603 switch (RelType) { 1604 case ELF::R_PPC64_TOC16: RelType = ELF::R_PPC64_ADDR16; break; 1605 case ELF::R_PPC64_TOC16_DS: RelType = ELF::R_PPC64_ADDR16_DS; break; 1606 case ELF::R_PPC64_TOC16_LO: RelType = ELF::R_PPC64_ADDR16_LO; break; 1607 case ELF::R_PPC64_TOC16_LO_DS: RelType = ELF::R_PPC64_ADDR16_LO_DS; break; 1608 case ELF::R_PPC64_TOC16_HI: RelType = ELF::R_PPC64_ADDR16_HI; break; 1609 case ELF::R_PPC64_TOC16_HA: RelType = ELF::R_PPC64_ADDR16_HA; break; 1610 default: llvm_unreachable("Wrong relocation type."); 1611 } 1612 1613 RelocationValueRef TOCValue; 1614 if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, TOCValue)) 1615 return std::move(Err); 1616 if (Value.SymbolName || Value.SectionID != TOCValue.SectionID) 1617 llvm_unreachable("Unsupported TOC relocation."); 1618 Value.Addend -= TOCValue.Addend; 1619 resolveRelocation(Sections[SectionID], Offset, Value.Addend, RelType, 0); 1620 } else { 1621 // There are two ways to refer to the TOC address directly: either 1622 // via a ELF::R_PPC64_TOC relocation (where both symbol and addend are 1623 // ignored), or via any relocation that refers to the magic ".TOC." 1624 // symbols (in which case the addend is respected). 1625 if (RelType == ELF::R_PPC64_TOC) { 1626 RelType = ELF::R_PPC64_ADDR64; 1627 if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, Value)) 1628 return std::move(Err); 1629 } else if (TargetName == ".TOC.") { 1630 if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, Value)) 1631 return std::move(Err); 1632 Value.Addend += Addend; 1633 } 1634 1635 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend); 1636 1637 if (Value.SymbolName) 1638 addRelocationForSymbol(RE, Value.SymbolName); 1639 else 1640 addRelocationForSection(RE, Value.SectionID); 1641 } 1642 } else if (Arch == Triple::systemz && 1643 (RelType == ELF::R_390_PLT32DBL || RelType == ELF::R_390_GOTENT)) { 1644 // Create function stubs for both PLT and GOT references, regardless of 1645 // whether the GOT reference is to data or code. The stub contains the 1646 // full address of the symbol, as needed by GOT references, and the 1647 // executable part only adds an overhead of 8 bytes. 1648 // 1649 // We could try to conserve space by allocating the code and data 1650 // parts of the stub separately. However, as things stand, we allocate 1651 // a stub for every relocation, so using a GOT in JIT code should be 1652 // no less space efficient than using an explicit constant pool. 1653 DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation."); 1654 SectionEntry &Section = Sections[SectionID]; 1655 1656 // Look for an existing stub. 1657 StubMap::const_iterator i = Stubs.find(Value); 1658 uintptr_t StubAddress; 1659 if (i != Stubs.end()) { 1660 StubAddress = uintptr_t(Section.getAddressWithOffset(i->second)); 1661 DEBUG(dbgs() << " Stub function found\n"); 1662 } else { 1663 // Create a new stub function. 1664 DEBUG(dbgs() << " Create a new stub function\n"); 1665 1666 uintptr_t BaseAddress = uintptr_t(Section.getAddress()); 1667 uintptr_t StubAlignment = getStubAlignment(); 1668 StubAddress = 1669 (BaseAddress + Section.getStubOffset() + StubAlignment - 1) & 1670 -StubAlignment; 1671 unsigned StubOffset = StubAddress - BaseAddress; 1672 1673 Stubs[Value] = StubOffset; 1674 createStubFunction((uint8_t *)StubAddress); 1675 RelocationEntry RE(SectionID, StubOffset + 8, ELF::R_390_64, 1676 Value.Offset); 1677 if (Value.SymbolName) 1678 addRelocationForSymbol(RE, Value.SymbolName); 1679 else 1680 addRelocationForSection(RE, Value.SectionID); 1681 Section.advanceStubOffset(getMaxStubSize()); 1682 } 1683 1684 if (RelType == ELF::R_390_GOTENT) 1685 resolveRelocation(Section, Offset, StubAddress + 8, ELF::R_390_PC32DBL, 1686 Addend); 1687 else 1688 resolveRelocation(Section, Offset, StubAddress, RelType, Addend); 1689 } else if (Arch == Triple::x86_64) { 1690 if (RelType == ELF::R_X86_64_PLT32) { 1691 // The way the PLT relocations normally work is that the linker allocates 1692 // the 1693 // PLT and this relocation makes a PC-relative call into the PLT. The PLT 1694 // entry will then jump to an address provided by the GOT. On first call, 1695 // the 1696 // GOT address will point back into PLT code that resolves the symbol. After 1697 // the first call, the GOT entry points to the actual function. 1698 // 1699 // For local functions we're ignoring all of that here and just replacing 1700 // the PLT32 relocation type with PC32, which will translate the relocation 1701 // into a PC-relative call directly to the function. For external symbols we 1702 // can't be sure the function will be within 2^32 bytes of the call site, so 1703 // we need to create a stub, which calls into the GOT. This case is 1704 // equivalent to the usual PLT implementation except that we use the stub 1705 // mechanism in RuntimeDyld (which puts stubs at the end of the section) 1706 // rather than allocating a PLT section. 1707 if (Value.SymbolName) { 1708 // This is a call to an external function. 1709 // Look for an existing stub. 1710 SectionEntry &Section = Sections[SectionID]; 1711 StubMap::const_iterator i = Stubs.find(Value); 1712 uintptr_t StubAddress; 1713 if (i != Stubs.end()) { 1714 StubAddress = uintptr_t(Section.getAddress()) + i->second; 1715 DEBUG(dbgs() << " Stub function found\n"); 1716 } else { 1717 // Create a new stub function (equivalent to a PLT entry). 1718 DEBUG(dbgs() << " Create a new stub function\n"); 1719 1720 uintptr_t BaseAddress = uintptr_t(Section.getAddress()); 1721 uintptr_t StubAlignment = getStubAlignment(); 1722 StubAddress = 1723 (BaseAddress + Section.getStubOffset() + StubAlignment - 1) & 1724 -StubAlignment; 1725 unsigned StubOffset = StubAddress - BaseAddress; 1726 Stubs[Value] = StubOffset; 1727 createStubFunction((uint8_t *)StubAddress); 1728 1729 // Bump our stub offset counter 1730 Section.advanceStubOffset(getMaxStubSize()); 1731 1732 // Allocate a GOT Entry 1733 uint64_t GOTOffset = allocateGOTEntries(SectionID, 1); 1734 1735 // The load of the GOT address has an addend of -4 1736 resolveGOTOffsetRelocation(SectionID, StubOffset + 2, GOTOffset - 4); 1737 1738 // Fill in the value of the symbol we're targeting into the GOT 1739 addRelocationForSymbol( 1740 computeGOTOffsetRE(SectionID, GOTOffset, 0, ELF::R_X86_64_64), 1741 Value.SymbolName); 1742 } 1743 1744 // Make the target call a call into the stub table. 1745 resolveRelocation(Section, Offset, StubAddress, ELF::R_X86_64_PC32, 1746 Addend); 1747 } else { 1748 RelocationEntry RE(SectionID, Offset, ELF::R_X86_64_PC32, Value.Addend, 1749 Value.Offset); 1750 addRelocationForSection(RE, Value.SectionID); 1751 } 1752 } else if (RelType == ELF::R_X86_64_GOTPCREL || 1753 RelType == ELF::R_X86_64_GOTPCRELX || 1754 RelType == ELF::R_X86_64_REX_GOTPCRELX) { 1755 uint64_t GOTOffset = allocateGOTEntries(SectionID, 1); 1756 resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend); 1757 1758 // Fill in the value of the symbol we're targeting into the GOT 1759 RelocationEntry RE = computeGOTOffsetRE(SectionID, GOTOffset, Value.Offset, ELF::R_X86_64_64); 1760 if (Value.SymbolName) 1761 addRelocationForSymbol(RE, Value.SymbolName); 1762 else 1763 addRelocationForSection(RE, Value.SectionID); 1764 } else if (RelType == ELF::R_X86_64_PC32) { 1765 Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset)); 1766 processSimpleRelocation(SectionID, Offset, RelType, Value); 1767 } else if (RelType == ELF::R_X86_64_PC64) { 1768 Value.Addend += support::ulittle64_t::ref(computePlaceholderAddress(SectionID, Offset)); 1769 processSimpleRelocation(SectionID, Offset, RelType, Value); 1770 } else { 1771 processSimpleRelocation(SectionID, Offset, RelType, Value); 1772 } 1773 } else { 1774 if (Arch == Triple::x86) { 1775 Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset)); 1776 } 1777 processSimpleRelocation(SectionID, Offset, RelType, Value); 1778 } 1779 return ++RelI; 1780} 1781 1782size_t RuntimeDyldELF::getGOTEntrySize() { 1783 // We don't use the GOT in all of these cases, but it's essentially free 1784 // to put them all here. 1785 size_t Result = 0; 1786 switch (Arch) { 1787 case Triple::x86_64: 1788 case Triple::aarch64: 1789 case Triple::aarch64_be: 1790 case Triple::ppc64: 1791 case Triple::ppc64le: 1792 case Triple::systemz: 1793 Result = sizeof(uint64_t); 1794 break; 1795 case Triple::x86: 1796 case Triple::arm: 1797 case Triple::thumb: 1798 Result = sizeof(uint32_t); 1799 break; 1800 case Triple::mips: 1801 case Triple::mipsel: 1802 case Triple::mips64: 1803 case Triple::mips64el: 1804 if (IsMipsO32ABI) 1805 Result = sizeof(uint32_t); 1806 else if (IsMipsN64ABI) 1807 Result = sizeof(uint64_t); 1808 else 1809 llvm_unreachable("Mips ABI not handled"); 1810 break; 1811 default: 1812 llvm_unreachable("Unsupported CPU type!"); 1813 } 1814 return Result; 1815} 1816 1817uint64_t RuntimeDyldELF::allocateGOTEntries(unsigned SectionID, unsigned no) 1818{ 1819 (void)SectionID; // The GOT Section is the same for all section in the object file 1820 if (GOTSectionID == 0) { 1821 GOTSectionID = Sections.size(); 1822 // Reserve a section id. We'll allocate the section later 1823 // once we know the total size 1824 Sections.push_back(SectionEntry(".got", nullptr, 0, 0, 0)); 1825 } 1826 uint64_t StartOffset = CurrentGOTIndex * getGOTEntrySize(); 1827 CurrentGOTIndex += no; 1828 return StartOffset; 1829} 1830 1831void RuntimeDyldELF::resolveGOTOffsetRelocation(unsigned SectionID, uint64_t Offset, uint64_t GOTOffset) 1832{ 1833 // Fill in the relative address of the GOT Entry into the stub 1834 RelocationEntry GOTRE(SectionID, Offset, ELF::R_X86_64_PC32, GOTOffset); 1835 addRelocationForSection(GOTRE, GOTSectionID); 1836} 1837 1838RelocationEntry RuntimeDyldELF::computeGOTOffsetRE(unsigned SectionID, uint64_t GOTOffset, uint64_t SymbolOffset, 1839 uint32_t Type) 1840{ 1841 (void)SectionID; // The GOT Section is the same for all section in the object file 1842 return RelocationEntry(GOTSectionID, GOTOffset, Type, SymbolOffset); 1843} 1844 1845Error RuntimeDyldELF::finalizeLoad(const ObjectFile &Obj, 1846 ObjSectionToIDMap &SectionMap) { 1847 if (IsMipsO32ABI) 1848 if (!PendingRelocs.empty()) 1849 return make_error<RuntimeDyldError>("Can't find matching LO16 reloc"); 1850 1851 // If necessary, allocate the global offset table 1852 if (GOTSectionID != 0) { 1853 // Allocate memory for the section 1854 size_t TotalSize = CurrentGOTIndex * getGOTEntrySize(); 1855 uint8_t *Addr = MemMgr.allocateDataSection(TotalSize, getGOTEntrySize(), 1856 GOTSectionID, ".got", false); 1857 if (!Addr) 1858 return make_error<RuntimeDyldError>("Unable to allocate memory for GOT!"); 1859 1860 Sections[GOTSectionID] = 1861 SectionEntry(".got", Addr, TotalSize, TotalSize, 0); 1862 1863 if (Checker) 1864 Checker->registerSection(Obj.getFileName(), GOTSectionID); 1865 1866 // For now, initialize all GOT entries to zero. We'll fill them in as 1867 // needed when GOT-based relocations are applied. 1868 memset(Addr, 0, TotalSize); 1869 if (IsMipsN64ABI) { 1870 // To correctly resolve Mips GOT relocations, we need a mapping from 1871 // object's sections to GOTs. 1872 for (section_iterator SI = Obj.section_begin(), SE = Obj.section_end(); 1873 SI != SE; ++SI) { 1874 if (SI->relocation_begin() != SI->relocation_end()) { 1875 section_iterator RelocatedSection = SI->getRelocatedSection(); 1876 ObjSectionToIDMap::iterator i = SectionMap.find(*RelocatedSection); 1877 assert (i != SectionMap.end()); 1878 SectionToGOTMap[i->second] = GOTSectionID; 1879 } 1880 } 1881 GOTSymbolOffsets.clear(); 1882 } 1883 } 1884 1885 // Look for and record the EH frame section. 1886 ObjSectionToIDMap::iterator i, e; 1887 for (i = SectionMap.begin(), e = SectionMap.end(); i != e; ++i) { 1888 const SectionRef &Section = i->first; 1889 StringRef Name; 1890 Section.getName(Name); 1891 if (Name == ".eh_frame") { 1892 UnregisteredEHFrameSections.push_back(i->second); 1893 break; 1894 } 1895 } 1896 1897 GOTSectionID = 0; 1898 CurrentGOTIndex = 0; 1899 1900 return Error::success(); 1901} 1902 1903bool RuntimeDyldELF::isCompatibleFile(const object::ObjectFile &Obj) const { 1904 return Obj.isELF(); 1905} 1906 1907bool RuntimeDyldELF::relocationNeedsStub(const RelocationRef &R) const { 1908 if (Arch != Triple::x86_64) 1909 return true; // Conservative answer 1910 1911 switch (R.getType()) { 1912 default: 1913 return true; // Conservative answer 1914 1915 1916 case ELF::R_X86_64_GOTPCREL: 1917 case ELF::R_X86_64_GOTPCRELX: 1918 case ELF::R_X86_64_REX_GOTPCRELX: 1919 case ELF::R_X86_64_PC32: 1920 case ELF::R_X86_64_PC64: 1921 case ELF::R_X86_64_64: 1922 // We know that these reloation types won't need a stub function. This list 1923 // can be extended as needed. 1924 return false; 1925 } 1926} 1927 1928} // namespace llvm 1929