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| //===-- RuntimeDyldELF.cpp - Run-time dynamic linker for MC-JIT -*- C++ -*-===// | |
| // | |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. | |
| // See https://llvm.org/LICENSE.txt for license information. | |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception | |
| // | |
| //===----------------------------------------------------------------------===// | |
| // | |
| // Implementation of ELF support for the MC-JIT runtime dynamic linker. | |
| // | |
| //===----------------------------------------------------------------------===// | |
| #include "RuntimeDyldELF.h" | |
| #include "RuntimeDyldCheckerImpl.h" | |
| #include "Targets/RuntimeDyldELFMips.h" | |
| #include "llvm/ADT/STLExtras.h" | |
| #include "llvm/ADT/StringRef.h" | |
| #include "llvm/ADT/Triple.h" | |
| #include "llvm/BinaryFormat/ELF.h" | |
| #include "llvm/Object/ELFObjectFile.h" | |
| #include "llvm/Object/ObjectFile.h" | |
| #include "llvm/Support/Endian.h" | |
| #include "llvm/Support/MemoryBuffer.h" | |
| using namespace llvm; | |
| using namespace llvm::object; | |
| using namespace llvm::support::endian; | |
| #define DEBUG_TYPE "dyld" | |
| static void or32le(void *P, int32_t V) { write32le(P, read32le(P) | V); } | |
| static void or32AArch64Imm(void *L, uint64_t Imm) { | |
| or32le(L, (Imm & 0xFFF) << 10); | |
| } | |
| template <class T> static void write(bool isBE, void *P, T V) { | |
| isBE ? write<T, support::big>(P, V) : write<T, support::little>(P, V); | |
| } | |
| static void write32AArch64Addr(void *L, uint64_t Imm) { | |
| uint32_t ImmLo = (Imm & 0x3) << 29; | |
| uint32_t ImmHi = (Imm & 0x1FFFFC) << 3; | |
| uint64_t Mask = (0x3 << 29) | (0x1FFFFC << 3); | |
| write32le(L, (read32le(L) & ~Mask) | ImmLo | ImmHi); | |
| } | |
| // Return the bits [Start, End] from Val shifted Start bits. | |
| // For instance, getBits(0xF0, 4, 8) returns 0xF. | |
| static uint64_t getBits(uint64_t Val, int Start, int End) { | |
| uint64_t Mask = ((uint64_t)1 << (End + 1 - Start)) - 1; | |
| return (Val >> Start) & Mask; | |
| } | |
| namespace { | |
| template <class ELFT> class DyldELFObject : public ELFObjectFile<ELFT> { | |
| LLVM_ELF_IMPORT_TYPES_ELFT(ELFT) | |
| typedef Elf_Shdr_Impl<ELFT> Elf_Shdr; | |
| typedef Elf_Sym_Impl<ELFT> Elf_Sym; | |
| typedef Elf_Rel_Impl<ELFT, false> Elf_Rel; | |
| typedef Elf_Rel_Impl<ELFT, true> Elf_Rela; | |
| typedef Elf_Ehdr_Impl<ELFT> Elf_Ehdr; | |
| typedef typename ELFT::uint addr_type; | |
| DyldELFObject(ELFObjectFile<ELFT> &&Obj); | |
| public: | |
| static Expected<std::unique_ptr<DyldELFObject>> | |
| create(MemoryBufferRef Wrapper); | |
| void updateSectionAddress(const SectionRef &Sec, uint64_t Addr); | |
| void updateSymbolAddress(const SymbolRef &SymRef, uint64_t Addr); | |
| // Methods for type inquiry through isa, cast and dyn_cast | |
| static bool classof(const Binary *v) { | |
| return (isa<ELFObjectFile<ELFT>>(v) && | |
| classof(cast<ELFObjectFile<ELFT>>(v))); | |
| } | |
| static bool classof(const ELFObjectFile<ELFT> *v) { | |
| return v->isDyldType(); | |
| } | |
| }; | |
| // The MemoryBuffer passed into this constructor is just a wrapper around the | |
| // actual memory. Ultimately, the Binary parent class will take ownership of | |
| // this MemoryBuffer object but not the underlying memory. | |
| template <class ELFT> | |
| DyldELFObject<ELFT>::DyldELFObject(ELFObjectFile<ELFT> &&Obj) | |
| : ELFObjectFile<ELFT>(std::move(Obj)) { | |
| this->isDyldELFObject = true; | |
| } | |
| template <class ELFT> | |
| Expected<std::unique_ptr<DyldELFObject<ELFT>>> | |
| DyldELFObject<ELFT>::create(MemoryBufferRef Wrapper) { | |
| auto Obj = ELFObjectFile<ELFT>::create(Wrapper); | |
| if (auto E = Obj.takeError()) | |
| return std::move(E); | |
| std::unique_ptr<DyldELFObject<ELFT>> Ret( | |
| new DyldELFObject<ELFT>(std::move(*Obj))); | |
| return std::move(Ret); | |
| } | |
| template <class ELFT> | |
| void DyldELFObject<ELFT>::updateSectionAddress(const SectionRef &Sec, | |
| uint64_t Addr) { | |
| DataRefImpl ShdrRef = Sec.getRawDataRefImpl(); | |
| Elf_Shdr *shdr = | |
| const_cast<Elf_Shdr *>(reinterpret_cast<const Elf_Shdr *>(ShdrRef.p)); | |
| // This assumes the address passed in matches the target address bitness | |
| // The template-based type cast handles everything else. | |
| shdr->sh_addr = static_cast<addr_type>(Addr); | |
| } | |
| template <class ELFT> | |
| void DyldELFObject<ELFT>::updateSymbolAddress(const SymbolRef &SymRef, | |
| uint64_t Addr) { | |
| Elf_Sym *sym = const_cast<Elf_Sym *>( | |
| ELFObjectFile<ELFT>::getSymbol(SymRef.getRawDataRefImpl())); | |
| // This assumes the address passed in matches the target address bitness | |
| // The template-based type cast handles everything else. | |
| sym->st_value = static_cast<addr_type>(Addr); | |
| } | |
| class LoadedELFObjectInfo final | |
| : public LoadedObjectInfoHelper<LoadedELFObjectInfo, | |
| RuntimeDyld::LoadedObjectInfo> { | |
| public: | |
| LoadedELFObjectInfo(RuntimeDyldImpl &RTDyld, ObjSectionToIDMap ObjSecToIDMap) | |
| : LoadedObjectInfoHelper(RTDyld, std::move(ObjSecToIDMap)) {} | |
| OwningBinary<ObjectFile> | |
| getObjectForDebug(const ObjectFile &Obj) const override; | |
| }; | |
| template <typename ELFT> | |
| static Expected<std::unique_ptr<DyldELFObject<ELFT>>> | |
| createRTDyldELFObject(MemoryBufferRef Buffer, const ObjectFile &SourceObject, | |
| const LoadedELFObjectInfo &L) { | |
| typedef typename ELFT::Shdr Elf_Shdr; | |
| typedef typename ELFT::uint addr_type; | |
| Expected<std::unique_ptr<DyldELFObject<ELFT>>> ObjOrErr = | |
| DyldELFObject<ELFT>::create(Buffer); | |
| if (Error E = ObjOrErr.takeError()) | |
| return std::move(E); | |
| std::unique_ptr<DyldELFObject<ELFT>> Obj = std::move(*ObjOrErr); | |
| // Iterate over all sections in the object. | |
| auto SI = SourceObject.section_begin(); | |
| for (const auto &Sec : Obj->sections()) { | |
| Expected<StringRef> NameOrErr = Sec.getName(); | |
| if (!NameOrErr) { | |
| consumeError(NameOrErr.takeError()); | |
| continue; | |
| } | |
| if (*NameOrErr != "") { | |
| DataRefImpl ShdrRef = Sec.getRawDataRefImpl(); | |
| Elf_Shdr *shdr = const_cast<Elf_Shdr *>( | |
| reinterpret_cast<const Elf_Shdr *>(ShdrRef.p)); | |
| if (uint64_t SecLoadAddr = L.getSectionLoadAddress(*SI)) { | |
| // This assumes that the address passed in matches the target address | |
| // bitness. The template-based type cast handles everything else. | |
| shdr->sh_addr = static_cast<addr_type>(SecLoadAddr); | |
| } | |
| } | |
| ++SI; | |
| } | |
| return std::move(Obj); | |
| } | |
| static OwningBinary<ObjectFile> | |
| createELFDebugObject(const ObjectFile &Obj, const LoadedELFObjectInfo &L) { | |
| assert(Obj.isELF() && "Not an ELF object file."); | |
| std::unique_ptr<MemoryBuffer> Buffer = | |
| MemoryBuffer::getMemBufferCopy(Obj.getData(), Obj.getFileName()); | |
| Expected<std::unique_ptr<ObjectFile>> DebugObj(nullptr); | |
| handleAllErrors(DebugObj.takeError()); | |
| if (Obj.getBytesInAddress() == 4 && Obj.isLittleEndian()) | |
| DebugObj = | |
| createRTDyldELFObject<ELF32LE>(Buffer->getMemBufferRef(), Obj, L); | |
| else if (Obj.getBytesInAddress() == 4 && !Obj.isLittleEndian()) | |
| DebugObj = | |
| createRTDyldELFObject<ELF32BE>(Buffer->getMemBufferRef(), Obj, L); | |
| else if (Obj.getBytesInAddress() == 8 && !Obj.isLittleEndian()) | |
| DebugObj = | |
| createRTDyldELFObject<ELF64BE>(Buffer->getMemBufferRef(), Obj, L); | |
| else if (Obj.getBytesInAddress() == 8 && Obj.isLittleEndian()) | |
| DebugObj = | |
| createRTDyldELFObject<ELF64LE>(Buffer->getMemBufferRef(), Obj, L); | |
| else | |
| llvm_unreachable("Unexpected ELF format"); | |
| handleAllErrors(DebugObj.takeError()); | |
| return OwningBinary<ObjectFile>(std::move(*DebugObj), std::move(Buffer)); | |
| } | |
| OwningBinary<ObjectFile> | |
| LoadedELFObjectInfo::getObjectForDebug(const ObjectFile &Obj) const { | |
| return createELFDebugObject(Obj, *this); | |
| } | |
| } // anonymous namespace | |
| namespace llvm { | |
| RuntimeDyldELF::RuntimeDyldELF(RuntimeDyld::MemoryManager &MemMgr, | |
| JITSymbolResolver &Resolver) | |
| : RuntimeDyldImpl(MemMgr, Resolver), GOTSectionID(0), CurrentGOTIndex(0) {} | |
| RuntimeDyldELF::~RuntimeDyldELF() {} | |
| void RuntimeDyldELF::registerEHFrames() { | |
| for (int i = 0, e = UnregisteredEHFrameSections.size(); i != e; ++i) { | |
| SID EHFrameSID = UnregisteredEHFrameSections[i]; | |
| uint8_t *EHFrameAddr = Sections[EHFrameSID].getAddress(); | |
| uint64_t EHFrameLoadAddr = Sections[EHFrameSID].getLoadAddress(); | |
| size_t EHFrameSize = Sections[EHFrameSID].getSize(); | |
| MemMgr.registerEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize); | |
| } | |
| UnregisteredEHFrameSections.clear(); | |
| } | |
| std::unique_ptr<RuntimeDyldELF> | |
| llvm::RuntimeDyldELF::create(Triple::ArchType Arch, | |
| RuntimeDyld::MemoryManager &MemMgr, | |
| JITSymbolResolver &Resolver) { | |
| switch (Arch) { | |
| default: | |
| return std::make_unique<RuntimeDyldELF>(MemMgr, Resolver); | |
| case Triple::mips: | |
| case Triple::mipsel: | |
| case Triple::mips64: | |
| case Triple::mips64el: | |
| return std::make_unique<RuntimeDyldELFMips>(MemMgr, Resolver); | |
| } | |
| } | |
| std::unique_ptr<RuntimeDyld::LoadedObjectInfo> | |
| RuntimeDyldELF::loadObject(const object::ObjectFile &O) { | |
| if (auto ObjSectionToIDOrErr = loadObjectImpl(O)) | |
| return std::make_unique<LoadedELFObjectInfo>(*this, *ObjSectionToIDOrErr); | |
| else { | |
| HasError = true; | |
| raw_string_ostream ErrStream(ErrorStr); | |
| logAllUnhandledErrors(ObjSectionToIDOrErr.takeError(), ErrStream); | |
| return nullptr; | |
| } | |
| } | |
| void RuntimeDyldELF::resolveX86_64Relocation(const SectionEntry &Section, | |
| uint64_t Offset, uint64_t Value, | |
| uint32_t Type, int64_t Addend, | |
| uint64_t SymOffset) { | |
| switch (Type) { | |
| default: | |
| report_fatal_error("Relocation type not implemented yet!"); | |
| break; | |
| case ELF::R_X86_64_NONE: | |
| break; | |
| case ELF::R_X86_64_64: { | |
| support::ulittle64_t::ref(Section.getAddressWithOffset(Offset)) = | |
| Value + Addend; | |
| LLVM_DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend)) << " at " | |
| << format("%p\n", Section.getAddressWithOffset(Offset))); | |
| break; | |
| } | |
| case ELF::R_X86_64_32: | |
| case ELF::R_X86_64_32S: { | |
| Value += Addend; | |
| assert((Type == ELF::R_X86_64_32 && (Value <= UINT32_MAX)) || | |
| (Type == ELF::R_X86_64_32S && | |
| ((int64_t)Value <= INT32_MAX && (int64_t)Value >= INT32_MIN))); | |
| uint32_t TruncatedAddr = (Value & 0xFFFFFFFF); | |
| support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) = | |
| TruncatedAddr; | |
| LLVM_DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr) << " at " | |
| << format("%p\n", Section.getAddressWithOffset(Offset))); | |
| break; | |
| } | |
| case ELF::R_X86_64_PC8: { | |
| uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); | |
| int64_t RealOffset = Value + Addend - FinalAddress; | |
| assert(isInt<8>(RealOffset)); | |
| int8_t TruncOffset = (RealOffset & 0xFF); | |
| Section.getAddress()[Offset] = TruncOffset; | |
| break; | |
| } | |
| case ELF::R_X86_64_PC32: { | |
| uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); | |
| int64_t RealOffset = Value + Addend - FinalAddress; | |
| assert(isInt<32>(RealOffset)); | |
| int32_t TruncOffset = (RealOffset & 0xFFFFFFFF); | |
| support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) = | |
| TruncOffset; | |
| break; | |
| } | |
| case ELF::R_X86_64_PC64: { | |
| uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); | |
| int64_t RealOffset = Value + Addend - FinalAddress; | |
| support::ulittle64_t::ref(Section.getAddressWithOffset(Offset)) = | |
| RealOffset; | |
| LLVM_DEBUG(dbgs() << "Writing " << format("%p", RealOffset) << " at " | |
| << format("%p\n", FinalAddress)); | |
| break; | |
| } | |
| case ELF::R_X86_64_GOTOFF64: { | |
| // Compute Value - GOTBase. | |
| uint64_t GOTBase = 0; | |
| for (const auto &Section : Sections) { | |
| if (Section.getName() == ".got") { | |
| GOTBase = Section.getLoadAddressWithOffset(0); | |
| break; | |
| } | |
| } | |
| assert(GOTBase != 0 && "missing GOT"); | |
| int64_t GOTOffset = Value - GOTBase + Addend; | |
| support::ulittle64_t::ref(Section.getAddressWithOffset(Offset)) = GOTOffset; | |
| break; | |
| } | |
| } | |
| } | |
| void RuntimeDyldELF::resolveX86Relocation(const SectionEntry &Section, | |
| uint64_t Offset, uint32_t Value, | |
| uint32_t Type, int32_t Addend) { | |
| switch (Type) { | |
| case ELF::R_386_32: { | |
| support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) = | |
| Value + Addend; | |
| break; | |
| } | |
| // Handle R_386_PLT32 like R_386_PC32 since it should be able to | |
| // reach any 32 bit address. | |
| case ELF::R_386_PLT32: | |
| case ELF::R_386_PC32: { | |
| uint32_t FinalAddress = | |
| Section.getLoadAddressWithOffset(Offset) & 0xFFFFFFFF; | |
| uint32_t RealOffset = Value + Addend - FinalAddress; | |
| support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) = | |
| RealOffset; | |
| break; | |
| } | |
| default: | |
| // There are other relocation types, but it appears these are the | |
| // only ones currently used by the LLVM ELF object writer | |
| report_fatal_error("Relocation type not implemented yet!"); | |
| break; | |
| } | |
| } | |
| void RuntimeDyldELF::resolveAArch64Relocation(const SectionEntry &Section, | |
| uint64_t Offset, uint64_t Value, | |
| uint32_t Type, int64_t Addend) { | |
| uint32_t *TargetPtr = | |
| reinterpret_cast<uint32_t *>(Section.getAddressWithOffset(Offset)); | |
| uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); | |
| // Data should use target endian. Code should always use little endian. | |
| bool isBE = Arch == Triple::aarch64_be; | |
| LLVM_DEBUG(dbgs() << "resolveAArch64Relocation, LocalAddress: 0x" | |
| << format("%llx", Section.getAddressWithOffset(Offset)) | |
| << " FinalAddress: 0x" << format("%llx", FinalAddress) | |
| << " Value: 0x" << format("%llx", Value) << " Type: 0x" | |
| << format("%x", Type) << " Addend: 0x" | |
| << format("%llx", Addend) << "\n"); | |
| switch (Type) { | |
| default: | |
| report_fatal_error("Relocation type not implemented yet!"); | |
| break; | |
| case ELF::R_AARCH64_ABS16: { | |
| uint64_t Result = Value + Addend; | |
| assert(static_cast<int64_t>(Result) >= INT16_MIN && Result < UINT16_MAX); | |
| write(isBE, TargetPtr, static_cast<uint16_t>(Result & 0xffffU)); | |
| break; | |
| } | |
| case ELF::R_AARCH64_ABS32: { | |
| uint64_t Result = Value + Addend; | |
| assert(static_cast<int64_t>(Result) >= INT32_MIN && Result < UINT32_MAX); | |
| write(isBE, TargetPtr, static_cast<uint32_t>(Result & 0xffffffffU)); | |
| break; | |
| } | |
| case ELF::R_AARCH64_ABS64: | |
| write(isBE, TargetPtr, Value + Addend); | |
| break; | |
| case ELF::R_AARCH64_PLT32: { | |
| uint64_t Result = Value + Addend - FinalAddress; | |
| assert(static_cast<int64_t>(Result) >= INT32_MIN && | |
| static_cast<int64_t>(Result) <= INT32_MAX); | |
| write(isBE, TargetPtr, static_cast<uint32_t>(Result)); | |
| break; | |
| } | |
| case ELF::R_AARCH64_PREL32: { | |
| uint64_t Result = Value + Addend - FinalAddress; | |
| assert(static_cast<int64_t>(Result) >= INT32_MIN && | |
| static_cast<int64_t>(Result) <= UINT32_MAX); | |
| write(isBE, TargetPtr, static_cast<uint32_t>(Result & 0xffffffffU)); | |
| break; | |
| } | |
| case ELF::R_AARCH64_PREL64: | |
| write(isBE, TargetPtr, Value + Addend - FinalAddress); | |
| break; | |
| case ELF::R_AARCH64_CALL26: // fallthrough | |
| case ELF::R_AARCH64_JUMP26: { | |
| // Operation: S+A-P. Set Call or B immediate value to bits fff_fffc of the | |
| // calculation. | |
| uint64_t BranchImm = Value + Addend - FinalAddress; | |
| // "Check that -2^27 <= result < 2^27". | |
| assert(isInt<28>(BranchImm)); | |
| or32le(TargetPtr, (BranchImm & 0x0FFFFFFC) >> 2); | |
| break; | |
| } | |
| case ELF::R_AARCH64_MOVW_UABS_G3: | |
| or32le(TargetPtr, ((Value + Addend) & 0xFFFF000000000000) >> 43); | |
| break; | |
| case ELF::R_AARCH64_MOVW_UABS_G2_NC: | |
| or32le(TargetPtr, ((Value + Addend) & 0xFFFF00000000) >> 27); | |
| break; | |
| case ELF::R_AARCH64_MOVW_UABS_G1_NC: | |
| or32le(TargetPtr, ((Value + Addend) & 0xFFFF0000) >> 11); | |
| break; | |
| case ELF::R_AARCH64_MOVW_UABS_G0_NC: | |
| or32le(TargetPtr, ((Value + Addend) & 0xFFFF) << 5); | |
| break; | |
| case ELF::R_AARCH64_ADR_PREL_PG_HI21: { | |
| // Operation: Page(S+A) - Page(P) | |
| uint64_t Result = | |
| ((Value + Addend) & ~0xfffULL) - (FinalAddress & ~0xfffULL); | |
| // Check that -2^32 <= X < 2^32 | |
| assert(isInt<33>(Result) && "overflow check failed for relocation"); | |
| // Immediate goes in bits 30:29 + 5:23 of ADRP instruction, taken | |
| // from bits 32:12 of X. | |
| write32AArch64Addr(TargetPtr, Result >> 12); | |
| break; | |
| } | |
| case ELF::R_AARCH64_ADD_ABS_LO12_NC: | |
| // Operation: S + A | |
| // Immediate goes in bits 21:10 of LD/ST instruction, taken | |
| // from bits 11:0 of X | |
| or32AArch64Imm(TargetPtr, Value + Addend); | |
| break; | |
| case ELF::R_AARCH64_LDST8_ABS_LO12_NC: | |
| // Operation: S + A | |
| // Immediate goes in bits 21:10 of LD/ST instruction, taken | |
| // from bits 11:0 of X | |
| or32AArch64Imm(TargetPtr, getBits(Value + Addend, 0, 11)); | |
| break; | |
| case ELF::R_AARCH64_LDST16_ABS_LO12_NC: | |
| // Operation: S + A | |
| // Immediate goes in bits 21:10 of LD/ST instruction, taken | |
| // from bits 11:1 of X | |
| or32AArch64Imm(TargetPtr, getBits(Value + Addend, 1, 11)); | |
| break; | |
| case ELF::R_AARCH64_LDST32_ABS_LO12_NC: | |
| // Operation: S + A | |
| // Immediate goes in bits 21:10 of LD/ST instruction, taken | |
| // from bits 11:2 of X | |
| or32AArch64Imm(TargetPtr, getBits(Value + Addend, 2, 11)); | |
| break; | |
| case ELF::R_AARCH64_LDST64_ABS_LO12_NC: | |
| // Operation: S + A | |
| // Immediate goes in bits 21:10 of LD/ST instruction, taken | |
| // from bits 11:3 of X | |
| or32AArch64Imm(TargetPtr, getBits(Value + Addend, 3, 11)); | |
| break; | |
| case ELF::R_AARCH64_LDST128_ABS_LO12_NC: | |
| // Operation: S + A | |
| // Immediate goes in bits 21:10 of LD/ST instruction, taken | |
| // from bits 11:4 of X | |
| or32AArch64Imm(TargetPtr, getBits(Value + Addend, 4, 11)); | |
| break; | |
| } | |
| } | |
| void RuntimeDyldELF::resolveARMRelocation(const SectionEntry &Section, | |
| uint64_t Offset, uint32_t Value, | |
| uint32_t Type, int32_t Addend) { | |
| // TODO: Add Thumb relocations. | |
| uint32_t *TargetPtr = | |
| reinterpret_cast<uint32_t *>(Section.getAddressWithOffset(Offset)); | |
| uint32_t FinalAddress = Section.getLoadAddressWithOffset(Offset) & 0xFFFFFFFF; | |
| Value += Addend; | |
| LLVM_DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: " | |
| << Section.getAddressWithOffset(Offset) | |
| << " FinalAddress: " << format("%p", FinalAddress) | |
| << " Value: " << format("%x", Value) | |
| << " Type: " << format("%x", Type) | |
| << " Addend: " << format("%x", Addend) << "\n"); | |
| switch (Type) { | |
| default: | |
| llvm_unreachable("Not implemented relocation type!"); | |
| case ELF::R_ARM_NONE: | |
| break; | |
| // Write a 31bit signed offset | |
| case ELF::R_ARM_PREL31: | |
| support::ulittle32_t::ref{TargetPtr} = | |
| (support::ulittle32_t::ref{TargetPtr} & 0x80000000) | | |
| ((Value - FinalAddress) & ~0x80000000); | |
| break; | |
| case ELF::R_ARM_TARGET1: | |
| case ELF::R_ARM_ABS32: | |
| support::ulittle32_t::ref{TargetPtr} = Value; | |
| break; | |
| // Write first 16 bit of 32 bit value to the mov instruction. | |
| // Last 4 bit should be shifted. | |
| case ELF::R_ARM_MOVW_ABS_NC: | |
| case ELF::R_ARM_MOVT_ABS: | |
| if (Type == ELF::R_ARM_MOVW_ABS_NC) | |
| Value = Value & 0xFFFF; | |
| else if (Type == ELF::R_ARM_MOVT_ABS) | |
| Value = (Value >> 16) & 0xFFFF; | |
| support::ulittle32_t::ref{TargetPtr} = | |
| (support::ulittle32_t::ref{TargetPtr} & ~0x000F0FFF) | (Value & 0xFFF) | | |
| (((Value >> 12) & 0xF) << 16); | |
| break; | |
| // Write 24 bit relative value to the branch instruction. | |
| case ELF::R_ARM_PC24: // Fall through. | |
| case ELF::R_ARM_CALL: // Fall through. | |
| case ELF::R_ARM_JUMP24: | |
| int32_t RelValue = static_cast<int32_t>(Value - FinalAddress - 8); | |
| RelValue = (RelValue & 0x03FFFFFC) >> 2; | |
| assert((support::ulittle32_t::ref{TargetPtr} & 0xFFFFFF) == 0xFFFFFE); | |
| support::ulittle32_t::ref{TargetPtr} = | |
| (support::ulittle32_t::ref{TargetPtr} & 0xFF000000) | RelValue; | |
| break; | |
| } | |
| } | |
| void RuntimeDyldELF::setMipsABI(const ObjectFile &Obj) { | |
| if (Arch == Triple::UnknownArch || | |
| !StringRef(Triple::getArchTypePrefix(Arch)).equals("mips")) { | |
| IsMipsO32ABI = false; | |
| IsMipsN32ABI = false; | |
| IsMipsN64ABI = false; | |
| return; | |
| } | |
| if (auto *E = dyn_cast<ELFObjectFileBase>(&Obj)) { | |
| unsigned AbiVariant = E->getPlatformFlags(); | |
| IsMipsO32ABI = AbiVariant & ELF::EF_MIPS_ABI_O32; | |
| IsMipsN32ABI = AbiVariant & ELF::EF_MIPS_ABI2; | |
| } | |
| IsMipsN64ABI = Obj.getFileFormatName().equals("elf64-mips"); | |
| } | |
| // Return the .TOC. section and offset. | |
| Error RuntimeDyldELF::findPPC64TOCSection(const ELFObjectFileBase &Obj, | |
| ObjSectionToIDMap &LocalSections, | |
| RelocationValueRef &Rel) { | |
| // Set a default SectionID in case we do not find a TOC section below. | |
| // This may happen for references to TOC base base (sym@toc, .odp | |
| // relocation) without a .toc directive. In this case just use the | |
| // first section (which is usually the .odp) since the code won't | |
| // reference the .toc base directly. | |
| Rel.SymbolName = nullptr; | |
| Rel.SectionID = 0; | |
| // The TOC consists of sections .got, .toc, .tocbss, .plt in that | |
| // order. The TOC starts where the first of these sections starts. | |
| for (auto &Section : Obj.sections()) { | |
| Expected<StringRef> NameOrErr = Section.getName(); | |
| if (!NameOrErr) | |
| return NameOrErr.takeError(); | |
| StringRef SectionName = *NameOrErr; | |
| if (SectionName == ".got" | |
| || SectionName == ".toc" | |
| || SectionName == ".tocbss" | |
| || SectionName == ".plt") { | |
| if (auto SectionIDOrErr = | |
| findOrEmitSection(Obj, Section, false, LocalSections)) | |
| Rel.SectionID = *SectionIDOrErr; | |
| else | |
| return SectionIDOrErr.takeError(); | |
| break; | |
| } | |
| } | |
| // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000 | |
| // thus permitting a full 64 Kbytes segment. | |
| Rel.Addend = 0x8000; | |
| return Error::success(); | |
| } | |
| // Returns the sections and offset associated with the ODP entry referenced | |
| // by Symbol. | |
| Error RuntimeDyldELF::findOPDEntrySection(const ELFObjectFileBase &Obj, | |
| ObjSectionToIDMap &LocalSections, | |
| RelocationValueRef &Rel) { | |
| // Get the ELF symbol value (st_value) to compare with Relocation offset in | |
| // .opd entries | |
| for (section_iterator si = Obj.section_begin(), se = Obj.section_end(); | |
| si != se; ++si) { | |
| Expected<section_iterator> RelSecOrErr = si->getRelocatedSection(); | |
| if (!RelSecOrErr) | |
| report_fatal_error(toString(RelSecOrErr.takeError())); | |
| section_iterator RelSecI = *RelSecOrErr; | |
| if (RelSecI == Obj.section_end()) | |
| continue; | |
| Expected<StringRef> NameOrErr = RelSecI->getName(); | |
| if (!NameOrErr) | |
| return NameOrErr.takeError(); | |
| StringRef RelSectionName = *NameOrErr; | |
| if (RelSectionName != ".opd") | |
| continue; | |
| for (elf_relocation_iterator i = si->relocation_begin(), | |
| e = si->relocation_end(); | |
| i != e;) { | |
| // The R_PPC64_ADDR64 relocation indicates the first field | |
| // of a .opd entry | |
| uint64_t TypeFunc = i->getType(); | |
| if (TypeFunc != ELF::R_PPC64_ADDR64) { | |
| ++i; | |
| continue; | |
| } | |
| uint64_t TargetSymbolOffset = i->getOffset(); | |
| symbol_iterator TargetSymbol = i->getSymbol(); | |
| int64_t Addend; | |
| if (auto AddendOrErr = i->getAddend()) | |
| Addend = *AddendOrErr; | |
| else | |
| return AddendOrErr.takeError(); | |
| ++i; | |
| if (i == e) | |
| break; | |
| // Just check if following relocation is a R_PPC64_TOC | |
| uint64_t TypeTOC = i->getType(); | |
| if (TypeTOC != ELF::R_PPC64_TOC) | |
| continue; | |
| // Finally compares the Symbol value and the target symbol offset | |
| // to check if this .opd entry refers to the symbol the relocation | |
| // points to. | |
| if (Rel.Addend != (int64_t)TargetSymbolOffset) | |
| continue; | |
| section_iterator TSI = Obj.section_end(); | |
| if (auto TSIOrErr = TargetSymbol->getSection()) | |
| TSI = *TSIOrErr; | |
| else | |
| return TSIOrErr.takeError(); | |
| assert(TSI != Obj.section_end() && "TSI should refer to a valid section"); | |
| bool IsCode = TSI->isText(); | |
| if (auto SectionIDOrErr = findOrEmitSection(Obj, *TSI, IsCode, | |
| LocalSections)) | |
| Rel.SectionID = *SectionIDOrErr; | |
| else | |
| return SectionIDOrErr.takeError(); | |
| Rel.Addend = (intptr_t)Addend; | |
| return Error::success(); | |
| } | |
| } | |
| llvm_unreachable("Attempting to get address of ODP entry!"); | |
| } | |
| // Relocation masks following the #lo(value), #hi(value), #ha(value), | |
| // #higher(value), #highera(value), #highest(value), and #highesta(value) | |
| // macros defined in section 4.5.1. Relocation Types of the PPC-elf64abi | |
| // document. | |
| static inline uint16_t applyPPClo(uint64_t value) { return value & 0xffff; } | |
| static inline uint16_t applyPPChi(uint64_t value) { | |
| return (value >> 16) & 0xffff; | |
| } | |
| static inline uint16_t applyPPCha (uint64_t value) { | |
| return ((value + 0x8000) >> 16) & 0xffff; | |
| } | |
| static inline uint16_t applyPPChigher(uint64_t value) { | |
| return (value >> 32) & 0xffff; | |
| } | |
| static inline uint16_t applyPPChighera (uint64_t value) { | |
| return ((value + 0x8000) >> 32) & 0xffff; | |
| } | |
| static inline uint16_t applyPPChighest(uint64_t value) { | |
| return (value >> 48) & 0xffff; | |
| } | |
| static inline uint16_t applyPPChighesta (uint64_t value) { | |
| return ((value + 0x8000) >> 48) & 0xffff; | |
| } | |
| void RuntimeDyldELF::resolvePPC32Relocation(const SectionEntry &Section, | |
| uint64_t Offset, uint64_t Value, | |
| uint32_t Type, int64_t Addend) { | |
| uint8_t *LocalAddress = Section.getAddressWithOffset(Offset); | |
| switch (Type) { | |
| default: | |
| report_fatal_error("Relocation type not implemented yet!"); | |
| break; | |
| case ELF::R_PPC_ADDR16_LO: | |
| writeInt16BE(LocalAddress, applyPPClo(Value + Addend)); | |
| break; | |
| case ELF::R_PPC_ADDR16_HI: | |
| writeInt16BE(LocalAddress, applyPPChi(Value + Addend)); | |
| break; | |
| case ELF::R_PPC_ADDR16_HA: | |
| writeInt16BE(LocalAddress, applyPPCha(Value + Addend)); | |
| break; | |
| } | |
| } | |
| void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section, | |
| uint64_t Offset, uint64_t Value, | |
| uint32_t Type, int64_t Addend) { | |
| uint8_t *LocalAddress = Section.getAddressWithOffset(Offset); | |
| switch (Type) { | |
| default: | |
| report_fatal_error("Relocation type not implemented yet!"); | |
| break; | |
| case ELF::R_PPC64_ADDR16: | |
| writeInt16BE(LocalAddress, applyPPClo(Value + Addend)); | |
| break; | |
| case ELF::R_PPC64_ADDR16_DS: | |
| writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3); | |
| break; | |
| case ELF::R_PPC64_ADDR16_LO: | |
| writeInt16BE(LocalAddress, applyPPClo(Value + Addend)); | |
| break; | |
| case ELF::R_PPC64_ADDR16_LO_DS: | |
| writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3); | |
| break; | |
| case ELF::R_PPC64_ADDR16_HI: | |
| case ELF::R_PPC64_ADDR16_HIGH: | |
| writeInt16BE(LocalAddress, applyPPChi(Value + Addend)); | |
| break; | |
| case ELF::R_PPC64_ADDR16_HA: | |
| case ELF::R_PPC64_ADDR16_HIGHA: | |
| writeInt16BE(LocalAddress, applyPPCha(Value + Addend)); | |
| break; | |
| case ELF::R_PPC64_ADDR16_HIGHER: | |
| writeInt16BE(LocalAddress, applyPPChigher(Value + Addend)); | |
| break; | |
| case ELF::R_PPC64_ADDR16_HIGHERA: | |
| writeInt16BE(LocalAddress, applyPPChighera(Value + Addend)); | |
| break; | |
| case ELF::R_PPC64_ADDR16_HIGHEST: | |
| writeInt16BE(LocalAddress, applyPPChighest(Value + Addend)); | |
| break; | |
| case ELF::R_PPC64_ADDR16_HIGHESTA: | |
| writeInt16BE(LocalAddress, applyPPChighesta(Value + Addend)); | |
| break; | |
| case ELF::R_PPC64_ADDR14: { | |
| assert(((Value + Addend) & 3) == 0); | |
| // Preserve the AA/LK bits in the branch instruction | |
| uint8_t aalk = *(LocalAddress + 3); | |
| writeInt16BE(LocalAddress + 2, (aalk & 3) | ((Value + Addend) & 0xfffc)); | |
| } break; | |
| case ELF::R_PPC64_REL16_LO: { | |
| uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); | |
| uint64_t Delta = Value - FinalAddress + Addend; | |
| writeInt16BE(LocalAddress, applyPPClo(Delta)); | |
| } break; | |
| case ELF::R_PPC64_REL16_HI: { | |
| uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); | |
| uint64_t Delta = Value - FinalAddress + Addend; | |
| writeInt16BE(LocalAddress, applyPPChi(Delta)); | |
| } break; | |
| case ELF::R_PPC64_REL16_HA: { | |
| uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); | |
| uint64_t Delta = Value - FinalAddress + Addend; | |
| writeInt16BE(LocalAddress, applyPPCha(Delta)); | |
| } break; | |
| case ELF::R_PPC64_ADDR32: { | |
| int64_t Result = static_cast<int64_t>(Value + Addend); | |
| if (SignExtend64<32>(Result) != Result) | |
| llvm_unreachable("Relocation R_PPC64_ADDR32 overflow"); | |
| writeInt32BE(LocalAddress, Result); | |
| } break; | |
| case ELF::R_PPC64_REL24: { | |
| uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); | |
| int64_t delta = static_cast<int64_t>(Value - FinalAddress + Addend); | |
| if (SignExtend64<26>(delta) != delta) | |
| llvm_unreachable("Relocation R_PPC64_REL24 overflow"); | |
| // We preserve bits other than LI field, i.e. PO and AA/LK fields. | |
| uint32_t Inst = readBytesUnaligned(LocalAddress, 4); | |
| writeInt32BE(LocalAddress, (Inst & 0xFC000003) | (delta & 0x03FFFFFC)); | |
| } break; | |
| case ELF::R_PPC64_REL32: { | |
| uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); | |
| int64_t delta = static_cast<int64_t>(Value - FinalAddress + Addend); | |
| if (SignExtend64<32>(delta) != delta) | |
| llvm_unreachable("Relocation R_PPC64_REL32 overflow"); | |
| writeInt32BE(LocalAddress, delta); | |
| } break; | |
| case ELF::R_PPC64_REL64: { | |
| uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); | |
| uint64_t Delta = Value - FinalAddress + Addend; | |
| writeInt64BE(LocalAddress, Delta); | |
| } break; | |
| case ELF::R_PPC64_ADDR64: | |
| writeInt64BE(LocalAddress, Value + Addend); | |
| break; | |
| } | |
| } | |
| void RuntimeDyldELF::resolveSystemZRelocation(const SectionEntry &Section, | |
| uint64_t Offset, uint64_t Value, | |
| uint32_t Type, int64_t Addend) { | |
| uint8_t *LocalAddress = Section.getAddressWithOffset(Offset); | |
| switch (Type) { | |
| default: | |
| report_fatal_error("Relocation type not implemented yet!"); | |
| break; | |
| case ELF::R_390_PC16DBL: | |
| case ELF::R_390_PLT16DBL: { | |
| int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset); | |
| assert(int16_t(Delta / 2) * 2 == Delta && "R_390_PC16DBL overflow"); | |
| writeInt16BE(LocalAddress, Delta / 2); | |
| break; | |
| } | |
| case ELF::R_390_PC32DBL: | |
| case ELF::R_390_PLT32DBL: { | |
| int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset); | |
| assert(int32_t(Delta / 2) * 2 == Delta && "R_390_PC32DBL overflow"); | |
| writeInt32BE(LocalAddress, Delta / 2); | |
| break; | |
| } | |
| case ELF::R_390_PC16: { | |
| int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset); | |
| assert(int16_t(Delta) == Delta && "R_390_PC16 overflow"); | |
| writeInt16BE(LocalAddress, Delta); | |
| break; | |
| } | |
| case ELF::R_390_PC32: { | |
| int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset); | |
| assert(int32_t(Delta) == Delta && "R_390_PC32 overflow"); | |
| writeInt32BE(LocalAddress, Delta); | |
| break; | |
| } | |
| case ELF::R_390_PC64: { | |
| int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset); | |
| writeInt64BE(LocalAddress, Delta); | |
| break; | |
| } | |
| case ELF::R_390_8: | |
| *LocalAddress = (uint8_t)(Value + Addend); | |
| break; | |
| case ELF::R_390_16: | |
| writeInt16BE(LocalAddress, Value + Addend); | |
| break; | |
| case ELF::R_390_32: | |
| writeInt32BE(LocalAddress, Value + Addend); | |
| break; | |
| case ELF::R_390_64: | |
| writeInt64BE(LocalAddress, Value + Addend); | |
| break; | |
| } | |
| } | |
| void RuntimeDyldELF::resolveBPFRelocation(const SectionEntry &Section, | |
| uint64_t Offset, uint64_t Value, | |
| uint32_t Type, int64_t Addend) { | |
| bool isBE = Arch == Triple::bpfeb; | |
| switch (Type) { | |
| default: | |
| report_fatal_error("Relocation type not implemented yet!"); | |
| break; | |
| case ELF::R_BPF_NONE: | |
| break; | |
| case ELF::R_BPF_64_64: { | |
| write(isBE, Section.getAddressWithOffset(Offset), Value + Addend); | |
| LLVM_DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend)) << " at " | |
| << format("%p\n", Section.getAddressWithOffset(Offset))); | |
| break; | |
| } | |
| case ELF::R_BPF_64_32: { | |
| Value += Addend; | |
| assert(Value <= UINT32_MAX); | |
| write(isBE, Section.getAddressWithOffset(Offset), static_cast<uint32_t>(Value)); | |
| LLVM_DEBUG(dbgs() << "Writing " << format("%p", Value) << " at " | |
| << format("%p\n", Section.getAddressWithOffset(Offset))); | |
| break; | |
| } | |
| } | |
| } | |
| // The target location for the relocation is described by RE.SectionID and | |
| // RE.Offset. RE.SectionID can be used to find the SectionEntry. Each | |
| // SectionEntry has three members describing its location. | |
| // SectionEntry::Address is the address at which the section has been loaded | |
| // into memory in the current (host) process. SectionEntry::LoadAddress is the | |
| // address that the section will have in the target process. | |
| // SectionEntry::ObjAddress is the address of the bits for this section in the | |
| // original emitted object image (also in the current address space). | |
| // | |
| // Relocations will be applied as if the section were loaded at | |
| // SectionEntry::LoadAddress, but they will be applied at an address based | |
| // on SectionEntry::Address. SectionEntry::ObjAddress will be used to refer to | |
| // Target memory contents if they are required for value calculations. | |
| // | |
| // The Value parameter here is the load address of the symbol for the | |
| // relocation to be applied. For relocations which refer to symbols in the | |
| // current object Value will be the LoadAddress of the section in which | |
| // the symbol resides (RE.Addend provides additional information about the | |
| // symbol location). For external symbols, Value will be the address of the | |
| // symbol in the target address space. | |
| void RuntimeDyldELF::resolveRelocation(const RelocationEntry &RE, | |
| uint64_t Value) { | |
| const SectionEntry &Section = Sections[RE.SectionID]; | |
| return resolveRelocation(Section, RE.Offset, Value, RE.RelType, RE.Addend, | |
| RE.SymOffset, RE.SectionID); | |
| } | |
| void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section, | |
| uint64_t Offset, uint64_t Value, | |
| uint32_t Type, int64_t Addend, | |
| uint64_t SymOffset, SID SectionID) { | |
| switch (Arch) { | |
| case Triple::x86_64: | |
| resolveX86_64Relocation(Section, Offset, Value, Type, Addend, SymOffset); | |
| break; | |
| case Triple::x86: | |
| resolveX86Relocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type, | |
| (uint32_t)(Addend & 0xffffffffL)); | |
| break; | |
| case Triple::aarch64: | |
| case Triple::aarch64_be: | |
| resolveAArch64Relocation(Section, Offset, Value, Type, Addend); | |
| break; | |
| case Triple::arm: // Fall through. | |
| case Triple::armeb: | |
| case Triple::thumb: | |
| case Triple::thumbeb: | |
| resolveARMRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type, | |
| (uint32_t)(Addend & 0xffffffffL)); | |
| break; | |
| case Triple::ppc: | |
| resolvePPC32Relocation(Section, Offset, Value, Type, Addend); | |
| break; | |
| case Triple::ppc64: // Fall through. | |
| case Triple::ppc64le: | |
| resolvePPC64Relocation(Section, Offset, Value, Type, Addend); | |
| break; | |
| case Triple::systemz: | |
| resolveSystemZRelocation(Section, Offset, Value, Type, Addend); | |
| break; | |
| case Triple::bpfel: | |
| case Triple::bpfeb: | |
| resolveBPFRelocation(Section, Offset, Value, Type, Addend); | |
| break; | |
| default: | |
| llvm_unreachable("Unsupported CPU type!"); | |
| } | |
| } | |
| void *RuntimeDyldELF::computePlaceholderAddress(unsigned SectionID, uint64_t Offset) const { | |
| return (void *)(Sections[SectionID].getObjAddress() + Offset); | |
| } | |
| void RuntimeDyldELF::processSimpleRelocation(unsigned SectionID, uint64_t Offset, unsigned RelType, RelocationValueRef Value) { | |
| RelocationEntry RE(SectionID, Offset, RelType, Value.Addend, Value.Offset); | |
| if (Value.SymbolName) | |
| addRelocationForSymbol(RE, Value.SymbolName); | |
| else | |
| addRelocationForSection(RE, Value.SectionID); | |
| } | |
| uint32_t RuntimeDyldELF::getMatchingLoRelocation(uint32_t RelType, | |
| bool IsLocal) const { | |
| switch (RelType) { | |
| case ELF::R_MICROMIPS_GOT16: | |
| if (IsLocal) | |
| return ELF::R_MICROMIPS_LO16; | |
| break; | |
| case ELF::R_MICROMIPS_HI16: | |
| return ELF::R_MICROMIPS_LO16; | |
| case ELF::R_MIPS_GOT16: | |
| if (IsLocal) | |
| return ELF::R_MIPS_LO16; | |
| break; | |
| case ELF::R_MIPS_HI16: | |
| return ELF::R_MIPS_LO16; | |
| case ELF::R_MIPS_PCHI16: | |
| return ELF::R_MIPS_PCLO16; | |
| default: | |
| break; | |
| } | |
| return ELF::R_MIPS_NONE; | |
| } | |
| // Sometimes we don't need to create thunk for a branch. | |
| // This typically happens when branch target is located | |
| // in the same object file. In such case target is either | |
| // a weak symbol or symbol in a different executable section. | |
| // This function checks if branch target is located in the | |
| // same object file and if distance between source and target | |
| // fits R_AARCH64_CALL26 relocation. If both conditions are | |
| // met, it emits direct jump to the target and returns true. | |
| // Otherwise false is returned and thunk is created. | |
| bool RuntimeDyldELF::resolveAArch64ShortBranch( | |
| unsigned SectionID, relocation_iterator RelI, | |
| const RelocationValueRef &Value) { | |
| uint64_t Address; | |
| if (Value.SymbolName) { | |
| auto Loc = GlobalSymbolTable.find(Value.SymbolName); | |
| // Don't create direct branch for external symbols. | |
| if (Loc == GlobalSymbolTable.end()) | |
| return false; | |
| const auto &SymInfo = Loc->second; | |
| Address = | |
| uint64_t(Sections[SymInfo.getSectionID()].getLoadAddressWithOffset( | |
| SymInfo.getOffset())); | |
| } else { | |
| Address = uint64_t(Sections[Value.SectionID].getLoadAddress()); | |
| } | |
| uint64_t Offset = RelI->getOffset(); | |
| uint64_t SourceAddress = Sections[SectionID].getLoadAddressWithOffset(Offset); | |
| // R_AARCH64_CALL26 requires immediate to be in range -2^27 <= imm < 2^27 | |
| // If distance between source and target is out of range then we should | |
| // create thunk. | |
| if (!isInt<28>(Address + Value.Addend - SourceAddress)) | |
| return false; | |
| resolveRelocation(Sections[SectionID], Offset, Address, RelI->getType(), | |
| Value.Addend); | |
| return true; | |
| } | |
| void RuntimeDyldELF::resolveAArch64Branch(unsigned SectionID, | |
| const RelocationValueRef &Value, | |
| relocation_iterator RelI, | |
| StubMap &Stubs) { | |
| LLVM_DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation."); | |
| SectionEntry &Section = Sections[SectionID]; | |
| uint64_t Offset = RelI->getOffset(); | |
| unsigned RelType = RelI->getType(); | |
| // Look for an existing stub. | |
| StubMap::const_iterator i = Stubs.find(Value); | |
| if (i != Stubs.end()) { | |
| resolveRelocation(Section, Offset, | |
| (uint64_t)Section.getAddressWithOffset(i->second), | |
| RelType, 0); | |
| LLVM_DEBUG(dbgs() << " Stub function found\n"); | |
| } else if (!resolveAArch64ShortBranch(SectionID, RelI, Value)) { | |
| // Create a new stub function. | |
| LLVM_DEBUG(dbgs() << " Create a new stub function\n"); | |
| Stubs[Value] = Section.getStubOffset(); | |
| uint8_t *StubTargetAddr = createStubFunction( | |
| Section.getAddressWithOffset(Section.getStubOffset())); | |
| RelocationEntry REmovz_g3(SectionID, StubTargetAddr - Section.getAddress(), | |
| ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend); | |
| RelocationEntry REmovk_g2(SectionID, | |
| StubTargetAddr - Section.getAddress() + 4, | |
| ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend); | |
| RelocationEntry REmovk_g1(SectionID, | |
| StubTargetAddr - Section.getAddress() + 8, | |
| ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend); | |
| RelocationEntry REmovk_g0(SectionID, | |
| StubTargetAddr - Section.getAddress() + 12, | |
| ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend); | |
| if (Value.SymbolName) { | |
| addRelocationForSymbol(REmovz_g3, Value.SymbolName); | |
| addRelocationForSymbol(REmovk_g2, Value.SymbolName); | |
| addRelocationForSymbol(REmovk_g1, Value.SymbolName); | |
| addRelocationForSymbol(REmovk_g0, Value.SymbolName); | |
| } else { | |
| addRelocationForSection(REmovz_g3, Value.SectionID); | |
| addRelocationForSection(REmovk_g2, Value.SectionID); | |
| addRelocationForSection(REmovk_g1, Value.SectionID); | |
| addRelocationForSection(REmovk_g0, Value.SectionID); | |
| } | |
| resolveRelocation(Section, Offset, | |
| reinterpret_cast<uint64_t>(Section.getAddressWithOffset( | |
| Section.getStubOffset())), | |
| RelType, 0); | |
| Section.advanceStubOffset(getMaxStubSize()); | |
| } | |
| } | |
| Expected<relocation_iterator> | |
| RuntimeDyldELF::processRelocationRef( | |
| unsigned SectionID, relocation_iterator RelI, const ObjectFile &O, | |
| ObjSectionToIDMap &ObjSectionToID, StubMap &Stubs) { | |
| const auto &Obj = cast<ELFObjectFileBase>(O); | |
| uint64_t RelType = RelI->getType(); | |
| int64_t Addend = 0; | |
| if (Expected<int64_t> AddendOrErr = ELFRelocationRef(*RelI).getAddend()) | |
| Addend = *AddendOrErr; | |
| else | |
| consumeError(AddendOrErr.takeError()); | |
| elf_symbol_iterator Symbol = RelI->getSymbol(); | |
| // Obtain the symbol name which is referenced in the relocation | |
| StringRef TargetName; | |
| if (Symbol != Obj.symbol_end()) { | |
| if (auto TargetNameOrErr = Symbol->getName()) | |
| TargetName = *TargetNameOrErr; | |
| else | |
| return TargetNameOrErr.takeError(); | |
| } | |
| LLVM_DEBUG(dbgs() << "\t\tRelType: " << RelType << " Addend: " << Addend | |
| << " TargetName: " << TargetName << "\n"); | |
| RelocationValueRef Value; | |
| // First search for the symbol in the local symbol table | |
| SymbolRef::Type SymType = SymbolRef::ST_Unknown; | |
| // Search for the symbol in the global symbol table | |
| RTDyldSymbolTable::const_iterator gsi = GlobalSymbolTable.end(); | |
| if (Symbol != Obj.symbol_end()) { | |
| gsi = GlobalSymbolTable.find(TargetName.data()); | |
| Expected<SymbolRef::Type> SymTypeOrErr = Symbol->getType(); | |
| if (!SymTypeOrErr) { | |
| std::string Buf; | |
| raw_string_ostream OS(Buf); | |
| logAllUnhandledErrors(SymTypeOrErr.takeError(), OS); | |
| OS.flush(); | |
| report_fatal_error(Buf); | |
| } | |
| SymType = *SymTypeOrErr; | |
| } | |
| if (gsi != GlobalSymbolTable.end()) { | |
| const auto &SymInfo = gsi->second; | |
| Value.SectionID = SymInfo.getSectionID(); | |
| Value.Offset = SymInfo.getOffset(); | |
| Value.Addend = SymInfo.getOffset() + Addend; | |
| } else { | |
| switch (SymType) { | |
| case SymbolRef::ST_Debug: { | |
| // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously | |
| // and can be changed by another developers. Maybe best way is add | |
| // a new symbol type ST_Section to SymbolRef and use it. | |
| auto SectionOrErr = Symbol->getSection(); | |
| if (!SectionOrErr) { | |
| std::string Buf; | |
| raw_string_ostream OS(Buf); | |
| logAllUnhandledErrors(SectionOrErr.takeError(), OS); | |
| OS.flush(); | |
| report_fatal_error(Buf); | |
| } | |
| section_iterator si = *SectionOrErr; | |
| if (si == Obj.section_end()) | |
| llvm_unreachable("Symbol section not found, bad object file format!"); | |
| LLVM_DEBUG(dbgs() << "\t\tThis is section symbol\n"); | |
| bool isCode = si->isText(); | |
| if (auto SectionIDOrErr = findOrEmitSection(Obj, (*si), isCode, | |
| ObjSectionToID)) | |
| Value.SectionID = *SectionIDOrErr; | |
| else | |
| return SectionIDOrErr.takeError(); | |
| Value.Addend = Addend; | |
| break; | |
| } | |
| case SymbolRef::ST_Data: | |
| case SymbolRef::ST_Function: | |
| case SymbolRef::ST_Unknown: { | |
| Value.SymbolName = TargetName.data(); | |
| Value.Addend = Addend; | |
| // Absolute relocations will have a zero symbol ID (STN_UNDEF), which | |
| // will manifest here as a NULL symbol name. | |
| // We can set this as a valid (but empty) symbol name, and rely | |
| // on addRelocationForSymbol to handle this. | |
| if (!Value.SymbolName) | |
| Value.SymbolName = ""; | |
| break; | |
| } | |
| default: | |
| llvm_unreachable("Unresolved symbol type!"); | |
| break; | |
| } | |
| } | |
| uint64_t Offset = RelI->getOffset(); | |
| LLVM_DEBUG(dbgs() << "\t\tSectionID: " << SectionID << " Offset: " << Offset | |
| << "\n"); | |
| if ((Arch == Triple::aarch64 || Arch == Triple::aarch64_be)) { | |
| if (RelType == ELF::R_AARCH64_CALL26 || RelType == ELF::R_AARCH64_JUMP26) { | |
| resolveAArch64Branch(SectionID, Value, RelI, Stubs); | |
| } else if (RelType == ELF::R_AARCH64_ADR_GOT_PAGE) { | |
| // Craete new GOT entry or find existing one. If GOT entry is | |
| // to be created, then we also emit ABS64 relocation for it. | |
| uint64_t GOTOffset = findOrAllocGOTEntry(Value, ELF::R_AARCH64_ABS64); | |
| resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend, | |
| ELF::R_AARCH64_ADR_PREL_PG_HI21); | |
| } else if (RelType == ELF::R_AARCH64_LD64_GOT_LO12_NC) { | |
| uint64_t GOTOffset = findOrAllocGOTEntry(Value, ELF::R_AARCH64_ABS64); | |
| resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend, | |
| ELF::R_AARCH64_LDST64_ABS_LO12_NC); | |
| } else { | |
| processSimpleRelocation(SectionID, Offset, RelType, Value); | |
| } | |
| } else if (Arch == Triple::arm) { | |
| if (RelType == ELF::R_ARM_PC24 || RelType == ELF::R_ARM_CALL || | |
| RelType == ELF::R_ARM_JUMP24) { | |
| // This is an ARM branch relocation, need to use a stub function. | |
| LLVM_DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.\n"); | |
| SectionEntry &Section = Sections[SectionID]; | |
| // Look for an existing stub. | |
| StubMap::const_iterator i = Stubs.find(Value); | |
| if (i != Stubs.end()) { | |
| resolveRelocation( | |
| Section, Offset, | |
| reinterpret_cast<uint64_t>(Section.getAddressWithOffset(i->second)), | |
| RelType, 0); | |
| LLVM_DEBUG(dbgs() << " Stub function found\n"); | |
| } else { | |
| // Create a new stub function. | |
| LLVM_DEBUG(dbgs() << " Create a new stub function\n"); | |
| Stubs[Value] = Section.getStubOffset(); | |
| uint8_t *StubTargetAddr = createStubFunction( | |
| Section.getAddressWithOffset(Section.getStubOffset())); | |
| RelocationEntry RE(SectionID, StubTargetAddr - Section.getAddress(), | |
| ELF::R_ARM_ABS32, Value.Addend); | |
| if (Value.SymbolName) | |
| addRelocationForSymbol(RE, Value.SymbolName); | |
| else | |
| addRelocationForSection(RE, Value.SectionID); | |
| resolveRelocation(Section, Offset, reinterpret_cast<uint64_t>( | |
| Section.getAddressWithOffset( | |
| Section.getStubOffset())), | |
| RelType, 0); | |
| Section.advanceStubOffset(getMaxStubSize()); | |
| } | |
| } else { | |
| uint32_t *Placeholder = | |
| reinterpret_cast<uint32_t*>(computePlaceholderAddress(SectionID, Offset)); | |
| if (RelType == ELF::R_ARM_PREL31 || RelType == ELF::R_ARM_TARGET1 || | |
| RelType == ELF::R_ARM_ABS32) { | |
| Value.Addend += *Placeholder; | |
| } else if (RelType == ELF::R_ARM_MOVW_ABS_NC || RelType == ELF::R_ARM_MOVT_ABS) { | |
| // See ELF for ARM documentation | |
| Value.Addend += (int16_t)((*Placeholder & 0xFFF) | (((*Placeholder >> 16) & 0xF) << 12)); | |
| } | |
| processSimpleRelocation(SectionID, Offset, RelType, Value); | |
| } | |
| } else if (IsMipsO32ABI) { | |
| uint8_t *Placeholder = reinterpret_cast<uint8_t *>( | |
| computePlaceholderAddress(SectionID, Offset)); | |
| uint32_t Opcode = readBytesUnaligned(Placeholder, 4); | |
| if (RelType == ELF::R_MIPS_26) { | |
| // This is an Mips branch relocation, need to use a stub function. | |
| LLVM_DEBUG(dbgs() << "\t\tThis is a Mips branch relocation."); | |
| SectionEntry &Section = Sections[SectionID]; | |
| // Extract the addend from the instruction. | |
| // We shift up by two since the Value will be down shifted again | |
| // when applying the relocation. | |
| uint32_t Addend = (Opcode & 0x03ffffff) << 2; | |
| Value.Addend += Addend; | |
| // Look up for existing stub. | |
| StubMap::const_iterator i = Stubs.find(Value); | |
| if (i != Stubs.end()) { | |
| RelocationEntry RE(SectionID, Offset, RelType, i->second); | |
| addRelocationForSection(RE, SectionID); | |
| LLVM_DEBUG(dbgs() << " Stub function found\n"); | |
| } else { | |
| // Create a new stub function. | |
| LLVM_DEBUG(dbgs() << " Create a new stub function\n"); | |
| Stubs[Value] = Section.getStubOffset(); | |
| unsigned AbiVariant = Obj.getPlatformFlags(); | |
| uint8_t *StubTargetAddr = createStubFunction( | |
| Section.getAddressWithOffset(Section.getStubOffset()), AbiVariant); | |
| // Creating Hi and Lo relocations for the filled stub instructions. | |
| RelocationEntry REHi(SectionID, StubTargetAddr - Section.getAddress(), | |
| ELF::R_MIPS_HI16, Value.Addend); | |
| RelocationEntry RELo(SectionID, | |
| StubTargetAddr - Section.getAddress() + 4, | |
| ELF::R_MIPS_LO16, Value.Addend); | |
| if (Value.SymbolName) { | |
| addRelocationForSymbol(REHi, Value.SymbolName); | |
| addRelocationForSymbol(RELo, Value.SymbolName); | |
| } else { | |
| addRelocationForSection(REHi, Value.SectionID); | |
| addRelocationForSection(RELo, Value.SectionID); | |
| } | |
| RelocationEntry RE(SectionID, Offset, RelType, Section.getStubOffset()); | |
| addRelocationForSection(RE, SectionID); | |
| Section.advanceStubOffset(getMaxStubSize()); | |
| } | |
| } else if (RelType == ELF::R_MIPS_HI16 || RelType == ELF::R_MIPS_PCHI16) { | |
| int64_t Addend = (Opcode & 0x0000ffff) << 16; | |
| RelocationEntry RE(SectionID, Offset, RelType, Addend); | |
| PendingRelocs.push_back(std::make_pair(Value, RE)); | |
| } else if (RelType == ELF::R_MIPS_LO16 || RelType == ELF::R_MIPS_PCLO16) { | |
| int64_t Addend = Value.Addend + SignExtend32<16>(Opcode & 0x0000ffff); | |
| for (auto I = PendingRelocs.begin(); I != PendingRelocs.end();) { | |
| const RelocationValueRef &MatchingValue = I->first; | |
| RelocationEntry &Reloc = I->second; | |
| if (MatchingValue == Value && | |
| RelType == getMatchingLoRelocation(Reloc.RelType) && | |
| SectionID == Reloc.SectionID) { | |
| Reloc.Addend += Addend; | |
| if (Value.SymbolName) | |
| addRelocationForSymbol(Reloc, Value.SymbolName); | |
| else | |
| addRelocationForSection(Reloc, Value.SectionID); | |
| I = PendingRelocs.erase(I); | |
| } else | |
| ++I; | |
| } | |
| RelocationEntry RE(SectionID, Offset, RelType, Addend); | |
| if (Value.SymbolName) | |
| addRelocationForSymbol(RE, Value.SymbolName); | |
| else | |
| addRelocationForSection(RE, Value.SectionID); | |
| } else { | |
| if (RelType == ELF::R_MIPS_32) | |
| Value.Addend += Opcode; | |
| else if (RelType == ELF::R_MIPS_PC16) | |
| Value.Addend += SignExtend32<18>((Opcode & 0x0000ffff) << 2); | |
| else if (RelType == ELF::R_MIPS_PC19_S2) | |
| Value.Addend += SignExtend32<21>((Opcode & 0x0007ffff) << 2); | |
| else if (RelType == ELF::R_MIPS_PC21_S2) | |
| Value.Addend += SignExtend32<23>((Opcode & 0x001fffff) << 2); | |
| else if (RelType == ELF::R_MIPS_PC26_S2) | |
| Value.Addend += SignExtend32<28>((Opcode & 0x03ffffff) << 2); | |
| processSimpleRelocation(SectionID, Offset, RelType, Value); | |
| } | |
| } else if (IsMipsN32ABI || IsMipsN64ABI) { | |
| uint32_t r_type = RelType & 0xff; | |
| RelocationEntry RE(SectionID, Offset, RelType, Value.Addend); | |
| if (r_type == ELF::R_MIPS_CALL16 || r_type == ELF::R_MIPS_GOT_PAGE | |
| || r_type == ELF::R_MIPS_GOT_DISP) { | |
| StringMap<uint64_t>::iterator i = GOTSymbolOffsets.find(TargetName); | |
| if (i != GOTSymbolOffsets.end()) | |
| RE.SymOffset = i->second; | |
| else { | |
| RE.SymOffset = allocateGOTEntries(1); | |
| GOTSymbolOffsets[TargetName] = RE.SymOffset; | |
| } | |
| if (Value.SymbolName) | |
| addRelocationForSymbol(RE, Value.SymbolName); | |
| else | |
| addRelocationForSection(RE, Value.SectionID); | |
| } else if (RelType == ELF::R_MIPS_26) { | |
| // This is an Mips branch relocation, need to use a stub function. | |
| LLVM_DEBUG(dbgs() << "\t\tThis is a Mips branch relocation."); | |
| SectionEntry &Section = Sections[SectionID]; | |
| // Look up for existing stub. | |
| StubMap::const_iterator i = Stubs.find(Value); | |
| if (i != Stubs.end()) { | |
| RelocationEntry RE(SectionID, Offset, RelType, i->second); | |
| addRelocationForSection(RE, SectionID); | |
| LLVM_DEBUG(dbgs() << " Stub function found\n"); | |
| } else { | |
| // Create a new stub function. | |
| LLVM_DEBUG(dbgs() << " Create a new stub function\n"); | |
| Stubs[Value] = Section.getStubOffset(); | |
| unsigned AbiVariant = Obj.getPlatformFlags(); | |
| uint8_t *StubTargetAddr = createStubFunction( | |
| Section.getAddressWithOffset(Section.getStubOffset()), AbiVariant); | |
| if (IsMipsN32ABI) { | |
| // Creating Hi and Lo relocations for the filled stub instructions. | |
| RelocationEntry REHi(SectionID, StubTargetAddr - Section.getAddress(), | |
| ELF::R_MIPS_HI16, Value.Addend); | |
| RelocationEntry RELo(SectionID, | |
| StubTargetAddr - Section.getAddress() + 4, | |
| ELF::R_MIPS_LO16, Value.Addend); | |
| if (Value.SymbolName) { | |
| addRelocationForSymbol(REHi, Value.SymbolName); | |
| addRelocationForSymbol(RELo, Value.SymbolName); | |
| } else { | |
| addRelocationForSection(REHi, Value.SectionID); | |
| addRelocationForSection(RELo, Value.SectionID); | |
| } | |
| } else { | |
| // Creating Highest, Higher, Hi and Lo relocations for the filled stub | |
| // instructions. | |
| RelocationEntry REHighest(SectionID, | |
| StubTargetAddr - Section.getAddress(), | |
| ELF::R_MIPS_HIGHEST, Value.Addend); | |
| RelocationEntry REHigher(SectionID, | |
| StubTargetAddr - Section.getAddress() + 4, | |
| ELF::R_MIPS_HIGHER, Value.Addend); | |
| RelocationEntry REHi(SectionID, | |
| StubTargetAddr - Section.getAddress() + 12, | |
| ELF::R_MIPS_HI16, Value.Addend); | |
| RelocationEntry RELo(SectionID, | |
| StubTargetAddr - Section.getAddress() + 20, | |
| ELF::R_MIPS_LO16, Value.Addend); | |
| if (Value.SymbolName) { | |
| addRelocationForSymbol(REHighest, Value.SymbolName); | |
| addRelocationForSymbol(REHigher, Value.SymbolName); | |
| addRelocationForSymbol(REHi, Value.SymbolName); | |
| addRelocationForSymbol(RELo, Value.SymbolName); | |
| } else { | |
| addRelocationForSection(REHighest, Value.SectionID); | |
| addRelocationForSection(REHigher, Value.SectionID); | |
| addRelocationForSection(REHi, Value.SectionID); | |
| addRelocationForSection(RELo, Value.SectionID); | |
| } | |
| } | |
| RelocationEntry RE(SectionID, Offset, RelType, Section.getStubOffset()); | |
| addRelocationForSection(RE, SectionID); | |
| Section.advanceStubOffset(getMaxStubSize()); | |
| } | |
| } else { | |
| processSimpleRelocation(SectionID, Offset, RelType, Value); | |
| } | |
| } else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) { | |
| if (RelType == ELF::R_PPC64_REL24) { | |
| // Determine ABI variant in use for this object. | |
| unsigned AbiVariant = Obj.getPlatformFlags(); | |
| AbiVariant &= ELF::EF_PPC64_ABI; | |
| // A PPC branch relocation will need a stub function if the target is | |
| // an external symbol (either Value.SymbolName is set, or SymType is | |
| // Symbol::ST_Unknown) or if the target address is not within the | |
| // signed 24-bits branch address. | |
| SectionEntry &Section = Sections[SectionID]; | |
| uint8_t *Target = Section.getAddressWithOffset(Offset); | |
| bool RangeOverflow = false; | |
| bool IsExtern = Value.SymbolName || SymType == SymbolRef::ST_Unknown; | |
| if (!IsExtern) { | |
| if (AbiVariant != 2) { | |
| // In the ELFv1 ABI, a function call may point to the .opd entry, | |
| // so the final symbol value is calculated based on the relocation | |
| // values in the .opd section. | |
| if (auto Err = findOPDEntrySection(Obj, ObjSectionToID, Value)) | |
| return std::move(Err); | |
| } else { | |
| // In the ELFv2 ABI, a function symbol may provide a local entry | |
| // point, which must be used for direct calls. | |
| if (Value.SectionID == SectionID){ | |
| uint8_t SymOther = Symbol->getOther(); | |
| Value.Addend += ELF::decodePPC64LocalEntryOffset(SymOther); | |
| } | |
| } | |
| uint8_t *RelocTarget = | |
| Sections[Value.SectionID].getAddressWithOffset(Value.Addend); | |
| int64_t delta = static_cast<int64_t>(Target - RelocTarget); | |
| // If it is within 26-bits branch range, just set the branch target | |
| if (SignExtend64<26>(delta) != delta) { | |
| RangeOverflow = true; | |
| } else if ((AbiVariant != 2) || | |
| (AbiVariant == 2 && Value.SectionID == SectionID)) { | |
| RelocationEntry RE(SectionID, Offset, RelType, Value.Addend); | |
| addRelocationForSection(RE, Value.SectionID); | |
| } | |
| } | |
| if (IsExtern || (AbiVariant == 2 && Value.SectionID != SectionID) || | |
| RangeOverflow) { | |
| // It is an external symbol (either Value.SymbolName is set, or | |
| // SymType is SymbolRef::ST_Unknown) or out of range. | |
| StubMap::const_iterator i = Stubs.find(Value); | |
| if (i != Stubs.end()) { | |
| // Symbol function stub already created, just relocate to it | |
| resolveRelocation(Section, Offset, | |
| reinterpret_cast<uint64_t>( | |
| Section.getAddressWithOffset(i->second)), | |
| RelType, 0); | |
| LLVM_DEBUG(dbgs() << " Stub function found\n"); | |
| } else { | |
| // Create a new stub function. | |
| LLVM_DEBUG(dbgs() << " Create a new stub function\n"); | |
| Stubs[Value] = Section.getStubOffset(); | |
| uint8_t *StubTargetAddr = createStubFunction( | |
| Section.getAddressWithOffset(Section.getStubOffset()), | |
| AbiVariant); | |
| RelocationEntry RE(SectionID, StubTargetAddr - Section.getAddress(), | |
| ELF::R_PPC64_ADDR64, Value.Addend); | |
| // Generates the 64-bits address loads as exemplified in section | |
| // 4.5.1 in PPC64 ELF ABI. Note that the relocations need to | |
| // apply to the low part of the instructions, so we have to update | |
| // the offset according to the target endianness. | |
| uint64_t StubRelocOffset = StubTargetAddr - Section.getAddress(); | |
| if (!IsTargetLittleEndian) | |
| StubRelocOffset += 2; | |
| RelocationEntry REhst(SectionID, StubRelocOffset + 0, | |
| ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend); | |
| RelocationEntry REhr(SectionID, StubRelocOffset + 4, | |
| ELF::R_PPC64_ADDR16_HIGHER, Value.Addend); | |
| RelocationEntry REh(SectionID, StubRelocOffset + 12, | |
| ELF::R_PPC64_ADDR16_HI, Value.Addend); | |
| RelocationEntry REl(SectionID, StubRelocOffset + 16, | |
| ELF::R_PPC64_ADDR16_LO, Value.Addend); | |
| if (Value.SymbolName) { | |
| addRelocationForSymbol(REhst, Value.SymbolName); | |
| addRelocationForSymbol(REhr, Value.SymbolName); | |
| addRelocationForSymbol(REh, Value.SymbolName); | |
| addRelocationForSymbol(REl, Value.SymbolName); | |
| } else { | |
| addRelocationForSection(REhst, Value.SectionID); | |
| addRelocationForSection(REhr, Value.SectionID); | |
| addRelocationForSection(REh, Value.SectionID); | |
| addRelocationForSection(REl, Value.SectionID); | |
| } | |
| resolveRelocation(Section, Offset, reinterpret_cast<uint64_t>( | |
| Section.getAddressWithOffset( | |
| Section.getStubOffset())), | |
| RelType, 0); | |
| Section.advanceStubOffset(getMaxStubSize()); | |
| } | |
| if (IsExtern || (AbiVariant == 2 && Value.SectionID != SectionID)) { | |
| // Restore the TOC for external calls | |
| if (AbiVariant == 2) | |
| writeInt32BE(Target + 4, 0xE8410018); // ld r2,24(r1) | |
| else | |
| writeInt32BE(Target + 4, 0xE8410028); // ld r2,40(r1) | |
| } | |
| } | |
| } else if (RelType == ELF::R_PPC64_TOC16 || | |
| RelType == ELF::R_PPC64_TOC16_DS || | |
| RelType == ELF::R_PPC64_TOC16_LO || | |
| RelType == ELF::R_PPC64_TOC16_LO_DS || | |
| RelType == ELF::R_PPC64_TOC16_HI || | |
| RelType == ELF::R_PPC64_TOC16_HA) { | |
| // These relocations are supposed to subtract the TOC address from | |
| // the final value. This does not fit cleanly into the RuntimeDyld | |
| // scheme, since there may be *two* sections involved in determining | |
| // the relocation value (the section of the symbol referred to by the | |
| // relocation, and the TOC section associated with the current module). | |
| // | |
| // Fortunately, these relocations are currently only ever generated | |
| // referring to symbols that themselves reside in the TOC, which means | |
| // that the two sections are actually the same. Thus they cancel out | |
| // and we can immediately resolve the relocation right now. | |
| switch (RelType) { | |
| case ELF::R_PPC64_TOC16: RelType = ELF::R_PPC64_ADDR16; break; | |
| case ELF::R_PPC64_TOC16_DS: RelType = ELF::R_PPC64_ADDR16_DS; break; | |
| case ELF::R_PPC64_TOC16_LO: RelType = ELF::R_PPC64_ADDR16_LO; break; | |
| case ELF::R_PPC64_TOC16_LO_DS: RelType = ELF::R_PPC64_ADDR16_LO_DS; break; | |
| case ELF::R_PPC64_TOC16_HI: RelType = ELF::R_PPC64_ADDR16_HI; break; | |
| case ELF::R_PPC64_TOC16_HA: RelType = ELF::R_PPC64_ADDR16_HA; break; | |
| default: llvm_unreachable("Wrong relocation type."); | |
| } | |
| RelocationValueRef TOCValue; | |
| if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, TOCValue)) | |
| return std::move(Err); | |
| if (Value.SymbolName || Value.SectionID != TOCValue.SectionID) | |
| llvm_unreachable("Unsupported TOC relocation."); | |
| Value.Addend -= TOCValue.Addend; | |
| resolveRelocation(Sections[SectionID], Offset, Value.Addend, RelType, 0); | |
| } else { | |
| // There are two ways to refer to the TOC address directly: either | |
| // via a ELF::R_PPC64_TOC relocation (where both symbol and addend are | |
| // ignored), or via any relocation that refers to the magic ".TOC." | |
| // symbols (in which case the addend is respected). | |
| if (RelType == ELF::R_PPC64_TOC) { | |
| RelType = ELF::R_PPC64_ADDR64; | |
| if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, Value)) | |
| return std::move(Err); | |
| } else if (TargetName == ".TOC.") { | |
| if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, Value)) | |
| return std::move(Err); | |
| Value.Addend += Addend; | |
| } | |
| RelocationEntry RE(SectionID, Offset, RelType, Value.Addend); | |
| if (Value.SymbolName) | |
| addRelocationForSymbol(RE, Value.SymbolName); | |
| else | |
| addRelocationForSection(RE, Value.SectionID); | |
| } | |
| } else if (Arch == Triple::systemz && | |
| (RelType == ELF::R_390_PLT32DBL || RelType == ELF::R_390_GOTENT)) { | |
| // Create function stubs for both PLT and GOT references, regardless of | |
| // whether the GOT reference is to data or code. The stub contains the | |
| // full address of the symbol, as needed by GOT references, and the | |
| // executable part only adds an overhead of 8 bytes. | |
| // | |
| // We could try to conserve space by allocating the code and data | |
| // parts of the stub separately. However, as things stand, we allocate | |
| // a stub for every relocation, so using a GOT in JIT code should be | |
| // no less space efficient than using an explicit constant pool. | |
| LLVM_DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation."); | |
| SectionEntry &Section = Sections[SectionID]; | |
| // Look for an existing stub. | |
| StubMap::const_iterator i = Stubs.find(Value); | |
| uintptr_t StubAddress; | |
| if (i != Stubs.end()) { | |
| StubAddress = uintptr_t(Section.getAddressWithOffset(i->second)); | |
| LLVM_DEBUG(dbgs() << " Stub function found\n"); | |
| } else { | |
| // Create a new stub function. | |
| LLVM_DEBUG(dbgs() << " Create a new stub function\n"); | |
| uintptr_t BaseAddress = uintptr_t(Section.getAddress()); | |
| uintptr_t StubAlignment = getStubAlignment(); | |
| StubAddress = | |
| (BaseAddress + Section.getStubOffset() + StubAlignment - 1) & | |
| -StubAlignment; | |
| unsigned StubOffset = StubAddress - BaseAddress; | |
| Stubs[Value] = StubOffset; | |
| createStubFunction((uint8_t *)StubAddress); | |
| RelocationEntry RE(SectionID, StubOffset + 8, ELF::R_390_64, | |
| Value.Offset); | |
| if (Value.SymbolName) | |
| addRelocationForSymbol(RE, Value.SymbolName); | |
| else | |
| addRelocationForSection(RE, Value.SectionID); | |
| Section.advanceStubOffset(getMaxStubSize()); | |
| } | |
| if (RelType == ELF::R_390_GOTENT) | |
| resolveRelocation(Section, Offset, StubAddress + 8, ELF::R_390_PC32DBL, | |
| Addend); | |
| else | |
| resolveRelocation(Section, Offset, StubAddress, RelType, Addend); | |
| } else if (Arch == Triple::x86_64) { | |
| if (RelType == ELF::R_X86_64_PLT32) { | |
| // The way the PLT relocations normally work is that the linker allocates | |
| // the | |
| // PLT and this relocation makes a PC-relative call into the PLT. The PLT | |
| // entry will then jump to an address provided by the GOT. On first call, | |
| // the | |
| // GOT address will point back into PLT code that resolves the symbol. After | |
| // the first call, the GOT entry points to the actual function. | |
| // | |
| // For local functions we're ignoring all of that here and just replacing | |
| // the PLT32 relocation type with PC32, which will translate the relocation | |
| // into a PC-relative call directly to the function. For external symbols we | |
| // can't be sure the function will be within 2^32 bytes of the call site, so | |
| // we need to create a stub, which calls into the GOT. This case is | |
| // equivalent to the usual PLT implementation except that we use the stub | |
| // mechanism in RuntimeDyld (which puts stubs at the end of the section) | |
| // rather than allocating a PLT section. | |
| if (Value.SymbolName) { | |
| // This is a call to an external function. | |
| // Look for an existing stub. | |
| SectionEntry &Section = Sections[SectionID]; | |
| StubMap::const_iterator i = Stubs.find(Value); | |
| uintptr_t StubAddress; | |
| if (i != Stubs.end()) { | |
| StubAddress = uintptr_t(Section.getAddress()) + i->second; | |
| LLVM_DEBUG(dbgs() << " Stub function found\n"); | |
| } else { | |
| // Create a new stub function (equivalent to a PLT entry). | |
| LLVM_DEBUG(dbgs() << " Create a new stub function\n"); | |
| uintptr_t BaseAddress = uintptr_t(Section.getAddress()); | |
| uintptr_t StubAlignment = getStubAlignment(); | |
| StubAddress = | |
| (BaseAddress + Section.getStubOffset() + StubAlignment - 1) & | |
| -StubAlignment; | |
| unsigned StubOffset = StubAddress - BaseAddress; | |
| Stubs[Value] = StubOffset; | |
| createStubFunction((uint8_t *)StubAddress); | |
| // Bump our stub offset counter | |
| Section.advanceStubOffset(getMaxStubSize()); | |
| // Allocate a GOT Entry | |
| uint64_t GOTOffset = allocateGOTEntries(1); | |
| // The load of the GOT address has an addend of -4 | |
| resolveGOTOffsetRelocation(SectionID, StubOffset + 2, GOTOffset - 4, | |
| ELF::R_X86_64_PC32); | |
| // Fill in the value of the symbol we're targeting into the GOT | |
| addRelocationForSymbol( | |
| computeGOTOffsetRE(GOTOffset, 0, ELF::R_X86_64_64), | |
| Value.SymbolName); | |
| } | |
| // Make the target call a call into the stub table. | |
| resolveRelocation(Section, Offset, StubAddress, ELF::R_X86_64_PC32, | |
| Addend); | |
| } else { | |
| RelocationEntry RE(SectionID, Offset, ELF::R_X86_64_PC32, Value.Addend, | |
| Value.Offset); | |
| addRelocationForSection(RE, Value.SectionID); | |
| } | |
| } else if (RelType == ELF::R_X86_64_GOTPCREL || | |
| RelType == ELF::R_X86_64_GOTPCRELX || | |
| RelType == ELF::R_X86_64_REX_GOTPCRELX) { | |
| uint64_t GOTOffset = allocateGOTEntries(1); | |
| resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend, | |
| ELF::R_X86_64_PC32); | |
| // Fill in the value of the symbol we're targeting into the GOT | |
| RelocationEntry RE = | |
| computeGOTOffsetRE(GOTOffset, Value.Offset, ELF::R_X86_64_64); | |
| if (Value.SymbolName) | |
| addRelocationForSymbol(RE, Value.SymbolName); | |
| else | |
| addRelocationForSection(RE, Value.SectionID); | |
| } else if (RelType == ELF::R_X86_64_GOT64) { | |
| // Fill in a 64-bit GOT offset. | |
| uint64_t GOTOffset = allocateGOTEntries(1); | |
| resolveRelocation(Sections[SectionID], Offset, GOTOffset, | |
| ELF::R_X86_64_64, 0); | |
| // Fill in the value of the symbol we're targeting into the GOT | |
| RelocationEntry RE = | |
| computeGOTOffsetRE(GOTOffset, Value.Offset, ELF::R_X86_64_64); | |
| if (Value.SymbolName) | |
| addRelocationForSymbol(RE, Value.SymbolName); | |
| else | |
| addRelocationForSection(RE, Value.SectionID); | |
| } else if (RelType == ELF::R_X86_64_GOTPC64) { | |
| // Materialize the address of the base of the GOT relative to the PC. | |
| // This doesn't create a GOT entry, but it does mean we need a GOT | |
| // section. | |
| (void)allocateGOTEntries(0); | |
| resolveGOTOffsetRelocation(SectionID, Offset, Addend, ELF::R_X86_64_PC64); | |
| } else if (RelType == ELF::R_X86_64_GOTOFF64) { | |
| // GOTOFF relocations ultimately require a section difference relocation. | |
| (void)allocateGOTEntries(0); | |
| processSimpleRelocation(SectionID, Offset, RelType, Value); | |
| } else if (RelType == ELF::R_X86_64_PC32) { | |
| Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset)); | |
| processSimpleRelocation(SectionID, Offset, RelType, Value); | |
| } else if (RelType == ELF::R_X86_64_PC64) { | |
| Value.Addend += support::ulittle64_t::ref(computePlaceholderAddress(SectionID, Offset)); | |
| processSimpleRelocation(SectionID, Offset, RelType, Value); | |
| } else { | |
| processSimpleRelocation(SectionID, Offset, RelType, Value); | |
| } | |
| } else { | |
| if (Arch == Triple::x86) { | |
| Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset)); | |
| } | |
| processSimpleRelocation(SectionID, Offset, RelType, Value); | |
| } | |
| return ++RelI; | |
| } | |
| size_t RuntimeDyldELF::getGOTEntrySize() { | |
| // We don't use the GOT in all of these cases, but it's essentially free | |
| // to put them all here. | |
| size_t Result = 0; | |
| switch (Arch) { | |
| case Triple::x86_64: | |
| case Triple::aarch64: | |
| case Triple::aarch64_be: | |
| case Triple::ppc64: | |
| case Triple::ppc64le: | |
| case Triple::systemz: | |
| Result = sizeof(uint64_t); | |
| break; | |
| case Triple::x86: | |
| case Triple::arm: | |
| case Triple::thumb: | |
| Result = sizeof(uint32_t); | |
| break; | |
| case Triple::mips: | |
| case Triple::mipsel: | |
| case Triple::mips64: | |
| case Triple::mips64el: | |
| if (IsMipsO32ABI || IsMipsN32ABI) | |
| Result = sizeof(uint32_t); | |
| else if (IsMipsN64ABI) | |
| Result = sizeof(uint64_t); | |
| else | |
| llvm_unreachable("Mips ABI not handled"); | |
| break; | |
| default: | |
| llvm_unreachable("Unsupported CPU type!"); | |
| } | |
| return Result; | |
| } | |
| uint64_t RuntimeDyldELF::allocateGOTEntries(unsigned no) { | |
| if (GOTSectionID == 0) { | |
| GOTSectionID = Sections.size(); | |
| // Reserve a section id. We'll allocate the section later | |
| // once we know the total size | |
| Sections.push_back(SectionEntry(".got", nullptr, 0, 0, 0)); | |
| } | |
| uint64_t StartOffset = CurrentGOTIndex * getGOTEntrySize(); | |
| CurrentGOTIndex += no; | |
| return StartOffset; | |
| } | |
| uint64_t RuntimeDyldELF::findOrAllocGOTEntry(const RelocationValueRef &Value, | |
| unsigned GOTRelType) { | |
| auto E = GOTOffsetMap.insert({Value, 0}); | |
| if (E.second) { | |
| uint64_t GOTOffset = allocateGOTEntries(1); | |
| // Create relocation for newly created GOT entry | |
| RelocationEntry RE = | |
| computeGOTOffsetRE(GOTOffset, Value.Offset, GOTRelType); | |
| if (Value.SymbolName) | |
| addRelocationForSymbol(RE, Value.SymbolName); | |
| else | |
| addRelocationForSection(RE, Value.SectionID); | |
| E.first->second = GOTOffset; | |
| } | |
| return E.first->second; | |
| } | |
| void RuntimeDyldELF::resolveGOTOffsetRelocation(unsigned SectionID, | |
| uint64_t Offset, | |
| uint64_t GOTOffset, | |
| uint32_t Type) { | |
| // Fill in the relative address of the GOT Entry into the stub | |
| RelocationEntry GOTRE(SectionID, Offset, Type, GOTOffset); | |
| addRelocationForSection(GOTRE, GOTSectionID); | |
| } | |
| RelocationEntry RuntimeDyldELF::computeGOTOffsetRE(uint64_t GOTOffset, | |
| uint64_t SymbolOffset, | |
| uint32_t Type) { | |
| return RelocationEntry(GOTSectionID, GOTOffset, Type, SymbolOffset); | |
| } | |
| Error RuntimeDyldELF::finalizeLoad(const ObjectFile &Obj, | |
| ObjSectionToIDMap &SectionMap) { | |
| if (IsMipsO32ABI) | |
| if (!PendingRelocs.empty()) | |
| return make_error<RuntimeDyldError>("Can't find matching LO16 reloc"); | |
| // If necessary, allocate the global offset table | |
| if (GOTSectionID != 0) { | |
| // Allocate memory for the section | |
| size_t TotalSize = CurrentGOTIndex * getGOTEntrySize(); | |
| uint8_t *Addr = MemMgr.allocateDataSection(TotalSize, getGOTEntrySize(), | |
| GOTSectionID, ".got", false); | |
| if (!Addr) | |
| return make_error<RuntimeDyldError>("Unable to allocate memory for GOT!"); | |
| Sections[GOTSectionID] = | |
| SectionEntry(".got", Addr, TotalSize, TotalSize, 0); | |
| // For now, initialize all GOT entries to zero. We'll fill them in as | |
| // needed when GOT-based relocations are applied. | |
| memset(Addr, 0, TotalSize); | |
| if (IsMipsN32ABI || IsMipsN64ABI) { | |
| // To correctly resolve Mips GOT relocations, we need a mapping from | |
| // object's sections to GOTs. | |
| for (section_iterator SI = Obj.section_begin(), SE = Obj.section_end(); | |
| SI != SE; ++SI) { | |
| if (SI->relocation_begin() != SI->relocation_end()) { | |
| Expected<section_iterator> RelSecOrErr = SI->getRelocatedSection(); | |
| if (!RelSecOrErr) | |
| return make_error<RuntimeDyldError>( | |
| toString(RelSecOrErr.takeError())); | |
| section_iterator RelocatedSection = *RelSecOrErr; | |
| ObjSectionToIDMap::iterator i = SectionMap.find(*RelocatedSection); | |
| assert (i != SectionMap.end()); | |
| SectionToGOTMap[i->second] = GOTSectionID; | |
| } | |
| } | |
| GOTSymbolOffsets.clear(); | |
| } | |
| } | |
| // Look for and record the EH frame section. | |
| ObjSectionToIDMap::iterator i, e; | |
| for (i = SectionMap.begin(), e = SectionMap.end(); i != e; ++i) { | |
| const SectionRef &Section = i->first; | |
| StringRef Name; | |
| Expected<StringRef> NameOrErr = Section.getName(); | |
| if (NameOrErr) | |
| Name = *NameOrErr; | |
| else | |
| consumeError(NameOrErr.takeError()); | |
| if (Name == ".eh_frame") { | |
| UnregisteredEHFrameSections.push_back(i->second); | |
| break; | |
| } | |
| } | |
| GOTSectionID = 0; | |
| CurrentGOTIndex = 0; | |
| return Error::success(); | |
| } | |
| bool RuntimeDyldELF::isCompatibleFile(const object::ObjectFile &Obj) const { | |
| return Obj.isELF(); | |
| } | |
| bool RuntimeDyldELF::relocationNeedsGot(const RelocationRef &R) const { | |
| unsigned RelTy = R.getType(); | |
| if (Arch == Triple::aarch64 || Arch == Triple::aarch64_be) | |
| return RelTy == ELF::R_AARCH64_ADR_GOT_PAGE || | |
| RelTy == ELF::R_AARCH64_LD64_GOT_LO12_NC; | |
| if (Arch == Triple::x86_64) | |
| return RelTy == ELF::R_X86_64_GOTPCREL || | |
| RelTy == ELF::R_X86_64_GOTPCRELX || | |
| RelTy == ELF::R_X86_64_GOT64 || | |
| RelTy == ELF::R_X86_64_REX_GOTPCRELX; | |
| return false; | |
| } | |
| bool RuntimeDyldELF::relocationNeedsStub(const RelocationRef &R) const { | |
| if (Arch != Triple::x86_64) | |
| return true; // Conservative answer | |
| switch (R.getType()) { | |
| default: | |
| return true; // Conservative answer | |
| case ELF::R_X86_64_GOTPCREL: | |
| case ELF::R_X86_64_GOTPCRELX: | |
| case ELF::R_X86_64_REX_GOTPCRELX: | |
| case ELF::R_X86_64_GOTPC64: | |
| case ELF::R_X86_64_GOT64: | |
| case ELF::R_X86_64_GOTOFF64: | |
| case ELF::R_X86_64_PC32: | |
| case ELF::R_X86_64_PC64: | |
| case ELF::R_X86_64_64: | |
| // We know that these reloation types won't need a stub function. This list | |
| // can be extended as needed. | |
| return false; | |
| } | |
| } | |
| } // namespace llvm |