| //===-- RuntimeDyldMachO.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 the MC-JIT runtime dynamic linker. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "RuntimeDyldMachO.h" |
| #include "Targets/RuntimeDyldMachOAArch64.h" |
| #include "Targets/RuntimeDyldMachOARM.h" |
| #include "Targets/RuntimeDyldMachOI386.h" |
| #include "Targets/RuntimeDyldMachOX86_64.h" |
| #include "llvm/ADT/STLExtras.h" |
| #include "llvm/ADT/StringRef.h" |
| |
| using namespace llvm; |
| using namespace llvm::object; |
| |
| #define DEBUG_TYPE "dyld" |
| |
| namespace { |
| |
| class LoadedMachOObjectInfo final |
| : public LoadedObjectInfoHelper<LoadedMachOObjectInfo, |
| RuntimeDyld::LoadedObjectInfo> { |
| public: |
| LoadedMachOObjectInfo(RuntimeDyldImpl &RTDyld, |
| ObjSectionToIDMap ObjSecToIDMap) |
| : LoadedObjectInfoHelper(RTDyld, std::move(ObjSecToIDMap)) {} |
| |
| OwningBinary<ObjectFile> |
| getObjectForDebug(const ObjectFile &Obj) const override { |
| return OwningBinary<ObjectFile>(); |
| } |
| }; |
| |
| } |
| |
| namespace llvm { |
| |
| int64_t RuntimeDyldMachO::memcpyAddend(const RelocationEntry &RE) const { |
| unsigned NumBytes = 1 << RE.Size; |
| uint8_t *Src = Sections[RE.SectionID].getAddress() + RE.Offset; |
| |
| return static_cast<int64_t>(readBytesUnaligned(Src, NumBytes)); |
| } |
| |
| Expected<relocation_iterator> |
| RuntimeDyldMachO::processScatteredVANILLA( |
| unsigned SectionID, relocation_iterator RelI, |
| const ObjectFile &BaseObjT, |
| RuntimeDyldMachO::ObjSectionToIDMap &ObjSectionToID, |
| bool TargetIsLocalThumbFunc) { |
| const MachOObjectFile &Obj = |
| static_cast<const MachOObjectFile&>(BaseObjT); |
| MachO::any_relocation_info RE = |
| Obj.getRelocation(RelI->getRawDataRefImpl()); |
| |
| SectionEntry &Section = Sections[SectionID]; |
| uint32_t RelocType = Obj.getAnyRelocationType(RE); |
| bool IsPCRel = Obj.getAnyRelocationPCRel(RE); |
| unsigned Size = Obj.getAnyRelocationLength(RE); |
| uint64_t Offset = RelI->getOffset(); |
| uint8_t *LocalAddress = Section.getAddressWithOffset(Offset); |
| unsigned NumBytes = 1 << Size; |
| int64_t Addend = readBytesUnaligned(LocalAddress, NumBytes); |
| |
| unsigned SymbolBaseAddr = Obj.getScatteredRelocationValue(RE); |
| section_iterator TargetSI = getSectionByAddress(Obj, SymbolBaseAddr); |
| assert(TargetSI != Obj.section_end() && "Can't find section for symbol"); |
| uint64_t SectionBaseAddr = TargetSI->getAddress(); |
| SectionRef TargetSection = *TargetSI; |
| bool IsCode = TargetSection.isText(); |
| uint32_t TargetSectionID = ~0U; |
| if (auto TargetSectionIDOrErr = |
| findOrEmitSection(Obj, TargetSection, IsCode, ObjSectionToID)) |
| TargetSectionID = *TargetSectionIDOrErr; |
| else |
| return TargetSectionIDOrErr.takeError(); |
| |
| Addend -= SectionBaseAddr; |
| RelocationEntry R(SectionID, Offset, RelocType, Addend, IsPCRel, Size); |
| R.IsTargetThumbFunc = TargetIsLocalThumbFunc; |
| |
| addRelocationForSection(R, TargetSectionID); |
| |
| return ++RelI; |
| } |
| |
| |
| Expected<RelocationValueRef> |
| RuntimeDyldMachO::getRelocationValueRef( |
| const ObjectFile &BaseTObj, const relocation_iterator &RI, |
| const RelocationEntry &RE, ObjSectionToIDMap &ObjSectionToID) { |
| |
| const MachOObjectFile &Obj = |
| static_cast<const MachOObjectFile &>(BaseTObj); |
| MachO::any_relocation_info RelInfo = |
| Obj.getRelocation(RI->getRawDataRefImpl()); |
| RelocationValueRef Value; |
| |
| bool IsExternal = Obj.getPlainRelocationExternal(RelInfo); |
| if (IsExternal) { |
| symbol_iterator Symbol = RI->getSymbol(); |
| StringRef TargetName; |
| if (auto TargetNameOrErr = Symbol->getName()) |
| TargetName = *TargetNameOrErr; |
| else |
| return TargetNameOrErr.takeError(); |
| RTDyldSymbolTable::const_iterator SI = |
| GlobalSymbolTable.find(TargetName.data()); |
| if (SI != GlobalSymbolTable.end()) { |
| const auto &SymInfo = SI->second; |
| Value.SectionID = SymInfo.getSectionID(); |
| Value.Offset = SymInfo.getOffset() + RE.Addend; |
| } else { |
| Value.SymbolName = TargetName.data(); |
| Value.Offset = RE.Addend; |
| } |
| } else { |
| SectionRef Sec = Obj.getAnyRelocationSection(RelInfo); |
| bool IsCode = Sec.isText(); |
| if (auto SectionIDOrErr = findOrEmitSection(Obj, Sec, IsCode, |
| ObjSectionToID)) |
| Value.SectionID = *SectionIDOrErr; |
| else |
| return SectionIDOrErr.takeError(); |
| uint64_t Addr = Sec.getAddress(); |
| Value.Offset = RE.Addend - Addr; |
| } |
| |
| return Value; |
| } |
| |
| void RuntimeDyldMachO::makeValueAddendPCRel(RelocationValueRef &Value, |
| const relocation_iterator &RI, |
| unsigned OffsetToNextPC) { |
| auto &O = *cast<MachOObjectFile>(RI->getObject()); |
| section_iterator SecI = O.getRelocationRelocatedSection(RI); |
| Value.Offset += RI->getOffset() + OffsetToNextPC + SecI->getAddress(); |
| } |
| |
| void RuntimeDyldMachO::dumpRelocationToResolve(const RelocationEntry &RE, |
| uint64_t Value) const { |
| const SectionEntry &Section = Sections[RE.SectionID]; |
| uint8_t *LocalAddress = Section.getAddress() + RE.Offset; |
| uint64_t FinalAddress = Section.getLoadAddress() + RE.Offset; |
| |
| dbgs() << "resolveRelocation Section: " << RE.SectionID |
| << " LocalAddress: " << format("%p", LocalAddress) |
| << " FinalAddress: " << format("0x%016" PRIx64, FinalAddress) |
| << " Value: " << format("0x%016" PRIx64, Value) << " Addend: " << RE.Addend |
| << " isPCRel: " << RE.IsPCRel << " MachoType: " << RE.RelType |
| << " Size: " << (1 << RE.Size) << "\n"; |
| } |
| |
| section_iterator |
| RuntimeDyldMachO::getSectionByAddress(const MachOObjectFile &Obj, |
| uint64_t Addr) { |
| section_iterator SI = Obj.section_begin(); |
| section_iterator SE = Obj.section_end(); |
| |
| for (; SI != SE; ++SI) { |
| uint64_t SAddr = SI->getAddress(); |
| uint64_t SSize = SI->getSize(); |
| if ((Addr >= SAddr) && (Addr < SAddr + SSize)) |
| return SI; |
| } |
| |
| return SE; |
| } |
| |
| |
| // Populate __pointers section. |
| Error RuntimeDyldMachO::populateIndirectSymbolPointersSection( |
| const MachOObjectFile &Obj, |
| const SectionRef &PTSection, |
| unsigned PTSectionID) { |
| assert(!Obj.is64Bit() && |
| "Pointer table section not supported in 64-bit MachO."); |
| |
| MachO::dysymtab_command DySymTabCmd = Obj.getDysymtabLoadCommand(); |
| MachO::section Sec32 = Obj.getSection(PTSection.getRawDataRefImpl()); |
| uint32_t PTSectionSize = Sec32.size; |
| unsigned FirstIndirectSymbol = Sec32.reserved1; |
| const unsigned PTEntrySize = 4; |
| unsigned NumPTEntries = PTSectionSize / PTEntrySize; |
| unsigned PTEntryOffset = 0; |
| |
| assert((PTSectionSize % PTEntrySize) == 0 && |
| "Pointers section does not contain a whole number of stubs?"); |
| |
| LLVM_DEBUG(dbgs() << "Populating pointer table section " |
| << Sections[PTSectionID].getName() << ", Section ID " |
| << PTSectionID << ", " << NumPTEntries << " entries, " |
| << PTEntrySize << " bytes each:\n"); |
| |
| for (unsigned i = 0; i < NumPTEntries; ++i) { |
| unsigned SymbolIndex = |
| Obj.getIndirectSymbolTableEntry(DySymTabCmd, FirstIndirectSymbol + i); |
| symbol_iterator SI = Obj.getSymbolByIndex(SymbolIndex); |
| StringRef IndirectSymbolName; |
| if (auto IndirectSymbolNameOrErr = SI->getName()) |
| IndirectSymbolName = *IndirectSymbolNameOrErr; |
| else |
| return IndirectSymbolNameOrErr.takeError(); |
| LLVM_DEBUG(dbgs() << " " << IndirectSymbolName << ": index " << SymbolIndex |
| << ", PT offset: " << PTEntryOffset << "\n"); |
| RelocationEntry RE(PTSectionID, PTEntryOffset, |
| MachO::GENERIC_RELOC_VANILLA, 0, false, 2); |
| addRelocationForSymbol(RE, IndirectSymbolName); |
| PTEntryOffset += PTEntrySize; |
| } |
| return Error::success(); |
| } |
| |
| bool RuntimeDyldMachO::isCompatibleFile(const object::ObjectFile &Obj) const { |
| return Obj.isMachO(); |
| } |
| |
| template <typename Impl> |
| Error |
| RuntimeDyldMachOCRTPBase<Impl>::finalizeLoad(const ObjectFile &Obj, |
| ObjSectionToIDMap &SectionMap) { |
| unsigned EHFrameSID = RTDYLD_INVALID_SECTION_ID; |
| unsigned TextSID = RTDYLD_INVALID_SECTION_ID; |
| unsigned ExceptTabSID = RTDYLD_INVALID_SECTION_ID; |
| |
| for (const auto &Section : Obj.sections()) { |
| StringRef Name; |
| if (Expected<StringRef> NameOrErr = Section.getName()) |
| Name = *NameOrErr; |
| else |
| consumeError(NameOrErr.takeError()); |
| |
| // Force emission of the __text, __eh_frame, and __gcc_except_tab sections |
| // if they're present. Otherwise call down to the impl to handle other |
| // sections that have already been emitted. |
| if (Name == "__text") { |
| if (auto TextSIDOrErr = findOrEmitSection(Obj, Section, true, SectionMap)) |
| TextSID = *TextSIDOrErr; |
| else |
| return TextSIDOrErr.takeError(); |
| } else if (Name == "__eh_frame") { |
| if (auto EHFrameSIDOrErr = findOrEmitSection(Obj, Section, false, |
| SectionMap)) |
| EHFrameSID = *EHFrameSIDOrErr; |
| else |
| return EHFrameSIDOrErr.takeError(); |
| } else if (Name == "__gcc_except_tab") { |
| if (auto ExceptTabSIDOrErr = findOrEmitSection(Obj, Section, true, |
| SectionMap)) |
| ExceptTabSID = *ExceptTabSIDOrErr; |
| else |
| return ExceptTabSIDOrErr.takeError(); |
| } else { |
| auto I = SectionMap.find(Section); |
| if (I != SectionMap.end()) |
| if (auto Err = impl().finalizeSection(Obj, I->second, Section)) |
| return Err; |
| } |
| } |
| UnregisteredEHFrameSections.push_back( |
| EHFrameRelatedSections(EHFrameSID, TextSID, ExceptTabSID)); |
| |
| return Error::success(); |
| } |
| |
| template <typename Impl> |
| unsigned char *RuntimeDyldMachOCRTPBase<Impl>::processFDE(uint8_t *P, |
| int64_t DeltaForText, |
| int64_t DeltaForEH) { |
| typedef typename Impl::TargetPtrT TargetPtrT; |
| |
| LLVM_DEBUG(dbgs() << "Processing FDE: Delta for text: " << DeltaForText |
| << ", Delta for EH: " << DeltaForEH << "\n"); |
| uint32_t Length = readBytesUnaligned(P, 4); |
| P += 4; |
| uint8_t *Ret = P + Length; |
| uint32_t Offset = readBytesUnaligned(P, 4); |
| if (Offset == 0) // is a CIE |
| return Ret; |
| |
| P += 4; |
| TargetPtrT FDELocation = readBytesUnaligned(P, sizeof(TargetPtrT)); |
| TargetPtrT NewLocation = FDELocation - DeltaForText; |
| writeBytesUnaligned(NewLocation, P, sizeof(TargetPtrT)); |
| |
| P += sizeof(TargetPtrT); |
| |
| // Skip the FDE address range |
| P += sizeof(TargetPtrT); |
| |
| uint8_t Augmentationsize = *P; |
| P += 1; |
| if (Augmentationsize != 0) { |
| TargetPtrT LSDA = readBytesUnaligned(P, sizeof(TargetPtrT)); |
| TargetPtrT NewLSDA = LSDA - DeltaForEH; |
| writeBytesUnaligned(NewLSDA, P, sizeof(TargetPtrT)); |
| } |
| |
| return Ret; |
| } |
| |
| static int64_t computeDelta(SectionEntry *A, SectionEntry *B) { |
| int64_t ObjDistance = static_cast<int64_t>(A->getObjAddress()) - |
| static_cast<int64_t>(B->getObjAddress()); |
| int64_t MemDistance = A->getLoadAddress() - B->getLoadAddress(); |
| return ObjDistance - MemDistance; |
| } |
| |
| template <typename Impl> |
| void RuntimeDyldMachOCRTPBase<Impl>::registerEHFrames() { |
| |
| for (int i = 0, e = UnregisteredEHFrameSections.size(); i != e; ++i) { |
| EHFrameRelatedSections &SectionInfo = UnregisteredEHFrameSections[i]; |
| if (SectionInfo.EHFrameSID == RTDYLD_INVALID_SECTION_ID || |
| SectionInfo.TextSID == RTDYLD_INVALID_SECTION_ID) |
| continue; |
| SectionEntry *Text = &Sections[SectionInfo.TextSID]; |
| SectionEntry *EHFrame = &Sections[SectionInfo.EHFrameSID]; |
| SectionEntry *ExceptTab = nullptr; |
| if (SectionInfo.ExceptTabSID != RTDYLD_INVALID_SECTION_ID) |
| ExceptTab = &Sections[SectionInfo.ExceptTabSID]; |
| |
| int64_t DeltaForText = computeDelta(Text, EHFrame); |
| int64_t DeltaForEH = 0; |
| if (ExceptTab) |
| DeltaForEH = computeDelta(ExceptTab, EHFrame); |
| |
| uint8_t *P = EHFrame->getAddress(); |
| uint8_t *End = P + EHFrame->getSize(); |
| while (P != End) { |
| P = processFDE(P, DeltaForText, DeltaForEH); |
| } |
| |
| MemMgr.registerEHFrames(EHFrame->getAddress(), EHFrame->getLoadAddress(), |
| EHFrame->getSize()); |
| } |
| UnregisteredEHFrameSections.clear(); |
| } |
| |
| std::unique_ptr<RuntimeDyldMachO> |
| RuntimeDyldMachO::create(Triple::ArchType Arch, |
| RuntimeDyld::MemoryManager &MemMgr, |
| JITSymbolResolver &Resolver) { |
| switch (Arch) { |
| default: |
| llvm_unreachable("Unsupported target for RuntimeDyldMachO."); |
| break; |
| case Triple::arm: |
| return std::make_unique<RuntimeDyldMachOARM>(MemMgr, Resolver); |
| case Triple::aarch64: |
| return std::make_unique<RuntimeDyldMachOAArch64>(MemMgr, Resolver); |
| case Triple::aarch64_32: |
| return std::make_unique<RuntimeDyldMachOAArch64>(MemMgr, Resolver); |
| case Triple::x86: |
| return std::make_unique<RuntimeDyldMachOI386>(MemMgr, Resolver); |
| case Triple::x86_64: |
| return std::make_unique<RuntimeDyldMachOX86_64>(MemMgr, Resolver); |
| } |
| } |
| |
| std::unique_ptr<RuntimeDyld::LoadedObjectInfo> |
| RuntimeDyldMachO::loadObject(const object::ObjectFile &O) { |
| if (auto ObjSectionToIDOrErr = loadObjectImpl(O)) |
| return std::make_unique<LoadedMachOObjectInfo>(*this, |
| *ObjSectionToIDOrErr); |
| else { |
| HasError = true; |
| raw_string_ostream ErrStream(ErrorStr); |
| logAllUnhandledErrors(ObjSectionToIDOrErr.takeError(), ErrStream); |
| return nullptr; |
| } |
| } |
| |
| } // end namespace llvm |
