diff options
Diffstat (limited to 'contrib/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp')
| -rw-r--r-- | contrib/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp | 1684 |
1 files changed, 1684 insertions, 0 deletions
diff --git a/contrib/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp b/contrib/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp new file mode 100644 index 000000000000..8f6b1849169a --- /dev/null +++ b/contrib/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp @@ -0,0 +1,1684 @@ +//===-- RuntimeDyldELF.cpp - Run-time dynamic linker for MC-JIT -*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// Implementation of ELF support for the MC-JIT runtime dynamic linker. +// +//===----------------------------------------------------------------------===// + +#include "RuntimeDyldELF.h" +#include "RuntimeDyldCheckerImpl.h" +#include "Targets/RuntimeDyldELFMips.h" +#include "llvm/ADT/IntervalMap.h" +#include "llvm/ADT/STLExtras.h" +#include "llvm/ADT/StringRef.h" +#include "llvm/ADT/Triple.h" +#include "llvm/MC/MCStreamer.h" +#include "llvm/Object/ELFObjectFile.h" +#include "llvm/Object/ObjectFile.h" +#include "llvm/Support/ELF.h" +#include "llvm/Support/Endian.h" +#include "llvm/Support/MemoryBuffer.h" +#include "llvm/Support/TargetRegistry.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 ELFDataTypeTypedefHelper<ELFT>::value_type addr_type; + +public: + DyldELFObject(MemoryBufferRef Wrapper, std::error_code &ec); + + 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 inline bool classof(const Binary *v) { + return (isa<ELFObjectFile<ELFT>>(v) && + classof(cast<ELFObjectFile<ELFT>>(v))); + } + static inline 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(MemoryBufferRef Wrapper, std::error_code &EC) + : ELFObjectFile<ELFT>(Wrapper, EC) { + this->isDyldELFObject = true; +} + +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 RuntimeDyld::LoadedObjectInfoHelper<LoadedELFObjectInfo> { +public: + LoadedELFObjectInfo(RuntimeDyldImpl &RTDyld, ObjSectionToIDMap ObjSecToIDMap) + : LoadedObjectInfoHelper(RTDyld, std::move(ObjSecToIDMap)) {} + + OwningBinary<ObjectFile> + getObjectForDebug(const ObjectFile &Obj) const override; +}; + +template <typename ELFT> +std::unique_ptr<DyldELFObject<ELFT>> +createRTDyldELFObject(MemoryBufferRef Buffer, + const ObjectFile &SourceObject, + const LoadedELFObjectInfo &L, + std::error_code &ec) { + typedef typename ELFFile<ELFT>::Elf_Shdr Elf_Shdr; + typedef typename ELFDataTypeTypedefHelper<ELFT>::value_type addr_type; + + std::unique_ptr<DyldELFObject<ELFT>> Obj = + llvm::make_unique<DyldELFObject<ELFT>>(Buffer, ec); + + // Iterate over all sections in the object. + auto SI = SourceObject.section_begin(); + for (const auto &Sec : Obj->sections()) { + StringRef SectionName; + Sec.getName(SectionName); + if (SectionName != "") { + 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 Obj; +} + +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()); + + std::error_code ec; + + std::unique_ptr<ObjectFile> DebugObj; + if (Obj.getBytesInAddress() == 4 && Obj.isLittleEndian()) { + typedef ELFType<support::little, false> ELF32LE; + DebugObj = createRTDyldELFObject<ELF32LE>(Buffer->getMemBufferRef(), Obj, L, + ec); + } else if (Obj.getBytesInAddress() == 4 && !Obj.isLittleEndian()) { + typedef ELFType<support::big, false> ELF32BE; + DebugObj = createRTDyldELFObject<ELF32BE>(Buffer->getMemBufferRef(), Obj, L, + ec); + } else if (Obj.getBytesInAddress() == 8 && !Obj.isLittleEndian()) { + typedef ELFType<support::big, true> ELF64BE; + DebugObj = createRTDyldELFObject<ELF64BE>(Buffer->getMemBufferRef(), Obj, L, + ec); + } else if (Obj.getBytesInAddress() == 8 && Obj.isLittleEndian()) { + typedef ELFType<support::little, true> ELF64LE; + DebugObj = createRTDyldELFObject<ELF64LE>(Buffer->getMemBufferRef(), Obj, L, + ec); + } else + llvm_unreachable("Unexpected ELF format"); + + assert(!ec && "Could not construct copy ELF object file"); + + 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); + RegisteredEHFrameSections.push_back(EHFrameSID); + } + UnregisteredEHFrameSections.clear(); +} + +void RuntimeDyldELF::deregisterEHFrames() { + for (int i = 0, e = RegisteredEHFrameSections.size(); i != e; ++i) { + SID EHFrameSID = RegisteredEHFrameSections[i]; + uint8_t *EHFrameAddr = Sections[EHFrameSID].getAddress(); + uint64_t EHFrameLoadAddr = Sections[EHFrameSID].getLoadAddress(); + size_t EHFrameSize = Sections[EHFrameSID].getSize(); + MemMgr.deregisterEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize); + } + RegisteredEHFrameSections.clear(); +} + +std::unique_ptr<RuntimeDyldELF> +llvm::RuntimeDyldELF::create(Triple::ArchType Arch, + RuntimeDyld::MemoryManager &MemMgr, + JITSymbolResolver &Resolver) { + switch (Arch) { + default: + return make_unique<RuntimeDyldELF>(MemMgr, Resolver); + case Triple::mips: + case Triple::mipsel: + case Triple::mips64: + case Triple::mips64el: + return make_unique<RuntimeDyldELFMips>(MemMgr, Resolver); + } +} + +std::unique_ptr<RuntimeDyld::LoadedObjectInfo> +RuntimeDyldELF::loadObject(const object::ObjectFile &O) { + if (auto ObjSectionToIDOrErr = loadObjectImpl(O)) + return llvm::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: + llvm_unreachable("Relocation type not implemented yet!"); + break; + case ELF::R_X86_64_64: { + support::ulittle64_t::ref(Section.getAddressWithOffset(Offset)) = + Value + Addend; + 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; + 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; + 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; + } + 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 + llvm_unreachable("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; + + 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: + llvm_unreachable("Relocation type not implemented yet!"); + break; + case ELF::R_AARCH64_ABS64: + write(isBE, TargetPtr, Value + Addend); + 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_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_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; + } +} + +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; + + 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; + } + unsigned AbiVariant; + Obj.getPlatformFlags(AbiVariant); + 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()) { + StringRef SectionName; + if (auto EC = Section.getName(SectionName)) + return errorCodeToError(EC); + + 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) { + section_iterator RelSecI = si->getRelocatedSection(); + if (RelSecI == Obj.section_end()) + continue; + + StringRef RelSectionName; + if (auto EC = RelSecI->getName(RelSectionName)) + return errorCodeToError(EC); + + 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 errorCodeToError(AddendOrErr.getError()); + + ++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: + llvm_unreachable("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: + llvm_unreachable("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: + writeInt16BE(LocalAddress, applyPPChi(Value + Addend)); + break; + case ELF::R_PPC64_ADDR16_HA: + 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: { + int32_t Result = static_cast<int32_t>(Value + Addend); + if (SignExtend32<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); + int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend); + if (SignExtend32<26>(delta) != delta) + llvm_unreachable("Relocation R_PPC64_REL24 overflow"); + // Generates a 'bl <address>' instruction + writeInt32BE(LocalAddress, 0x48000001 | (delta & 0x03FFFFFC)); + } break; + case ELF::R_PPC64_REL32: { + uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset); + int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend); + if (SignExtend32<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: + llvm_unreachable("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_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_64: + writeInt64BE(LocalAddress, Value + Addend); + break; + case ELF::R_390_PC64: { + int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset); + writeInt64BE(LocalAddress, Delta); + 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; + 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; +} + +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(); + ErrorOr<int64_t> AddendOrErr = ELFRelocationRef(*RelI).getAddend(); + int64_t Addend = AddendOrErr ? *AddendOrErr : 0; + 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(); + } + 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!"); + 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(); + + DEBUG(dbgs() << "\t\tSectionID: " << SectionID << " Offset: " << Offset + << "\n"); + if ((Arch == Triple::aarch64 || Arch == Triple::aarch64_be) && + (RelType == ELF::R_AARCH64_CALL26 || RelType == ELF::R_AARCH64_JUMP26)) { + // This is an AArch64 branch relocation, need to use a stub function. + DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation."); + SectionEntry &Section = Sections[SectionID]; + + // 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); + DEBUG(dbgs() << " Stub function found\n"); + } else if (!resolveAArch64ShortBranch(SectionID, RelI, Value)) { + // Create a new stub function. + 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()); + } + } 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. + 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); + DEBUG(dbgs() << " Stub function found\n"); + } else { + // Create a new stub function. + 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. + 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); + DEBUG(dbgs() << " Stub function found\n"); + } else { + // Create a new stub function. + DEBUG(dbgs() << " Create a new stub function\n"); + Stubs[Value] = Section.getStubOffset(); + + unsigned AbiVariant; + O.getPlatformFlags(AbiVariant); + + 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(SectionID, 1); + GOTSymbolOffsets[TargetName] = RE.SymOffset; + } + } + if (Value.SymbolName) + addRelocationForSymbol(RE, Value.SymbolName); + else + addRelocationForSection(RE, Value.SectionID); + } 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); + AbiVariant &= ELF::EF_PPC64_ABI; + // A PPC branch relocation will need a stub function if the target is + // an external symbol (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; + if (SymType != SymbolRef::ST_Unknown) { + 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. + uint8_t SymOther = Symbol->getOther(); + Value.Addend += ELF::decodePPC64LocalEntryOffset(SymOther); + } + uint8_t *RelocTarget = + Sections[Value.SectionID].getAddressWithOffset(Value.Addend); + int32_t delta = static_cast<int32_t>(Target - RelocTarget); + // If it is within 26-bits branch range, just set the branch target + if (SignExtend32<26>(delta) == delta) { + RelocationEntry RE(SectionID, Offset, RelType, Value.Addend); + if (Value.SymbolName) + addRelocationForSymbol(RE, Value.SymbolName); + else + addRelocationForSection(RE, Value.SectionID); + } else { + RangeOverflow = true; + } + } + if (SymType == SymbolRef::ST_Unknown || RangeOverflow) { + // It is an external symbol (SymbolRef::ST_Unknown) or within a range + // larger than 24-bits. + 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); + DEBUG(dbgs() << " Stub function found\n"); + } else { + // Create a new stub function. + 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 (SymType == SymbolRef::ST_Unknown) { + // Restore the TOC for external calls + if (AbiVariant == 2) + writeInt32BE(Target + 4, 0xE8410018); // ld r2,28(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. + 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)); + DEBUG(dbgs() << " Stub function found\n"); + } else { + // Create a new stub function. + 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; + DEBUG(dbgs() << " Stub function found\n"); + } else { + // Create a new stub function (equivalent to a PLT entry). + 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(SectionID, 1); + + // The load of the GOT address has an addend of -4 + resolveGOTOffsetRelocation(SectionID, StubOffset + 2, GOTOffset - 4); + + // Fill in the value of the symbol we're targeting into the GOT + addRelocationForSymbol( + computeGOTOffsetRE(SectionID, 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(SectionID, 1); + resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend); + + // Fill in the value of the symbol we're targeting into the GOT + RelocationEntry RE = computeGOTOffsetRE(SectionID, 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_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 SectionID, unsigned no) +{ + (void)SectionID; // The GOT Section is the same for all section in the object file + 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; +} + +void RuntimeDyldELF::resolveGOTOffsetRelocation(unsigned SectionID, uint64_t Offset, uint64_t GOTOffset) +{ + // Fill in the relative address of the GOT Entry into the stub + RelocationEntry GOTRE(SectionID, Offset, ELF::R_X86_64_PC32, GOTOffset); + addRelocationForSection(GOTRE, GOTSectionID); +} + +RelocationEntry RuntimeDyldELF::computeGOTOffsetRE(unsigned SectionID, uint64_t GOTOffset, uint64_t SymbolOffset, + uint32_t Type) +{ + (void)SectionID; // The GOT Section is the same for all section in the object file + 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); + + if (Checker) + Checker->registerSection(Obj.getFileName(), GOTSectionID); + + // 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()) { + section_iterator RelocatedSection = SI->getRelocatedSection(); + 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; + Section.getName(Name); + 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::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_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 |