1797 lines
69 KiB
C++
1797 lines
69 KiB
C++
//===-- RuntimeDyldELF.cpp - Run-time dynamic linker for MC-JIT -*- C++ -*-===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// Implementation of ELF support for the MC-JIT runtime dynamic linker.
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//
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//===----------------------------------------------------------------------===//
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#include "RuntimeDyldELF.h"
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#include "RuntimeDyldCheckerImpl.h"
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#include "Targets/RuntimeDyldELFMips.h"
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#include "llvm/ADT/IntervalMap.h"
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#include "llvm/ADT/STLExtras.h"
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#include "llvm/ADT/StringRef.h"
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#include "llvm/ADT/Triple.h"
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#include "llvm/MC/MCStreamer.h"
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#include "llvm/Object/ELFObjectFile.h"
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#include "llvm/Object/ObjectFile.h"
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#include "llvm/Support/ELF.h"
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#include "llvm/Support/Endian.h"
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#include "llvm/Support/MemoryBuffer.h"
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#include "llvm/Support/TargetRegistry.h"
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using namespace llvm;
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using namespace llvm::object;
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using namespace llvm::support::endian;
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#define DEBUG_TYPE "dyld"
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static void or32le(void *P, int32_t V) { write32le(P, read32le(P) | V); }
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static void or32AArch64Imm(void *L, uint64_t Imm) {
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or32le(L, (Imm & 0xFFF) << 10);
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}
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template <class T> static void write(bool isBE, void *P, T V) {
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isBE ? write<T, support::big>(P, V) : write<T, support::little>(P, V);
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}
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static void write32AArch64Addr(void *L, uint64_t Imm) {
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uint32_t ImmLo = (Imm & 0x3) << 29;
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uint32_t ImmHi = (Imm & 0x1FFFFC) << 3;
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uint64_t Mask = (0x3 << 29) | (0x1FFFFC << 3);
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write32le(L, (read32le(L) & ~Mask) | ImmLo | ImmHi);
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}
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// Return the bits [Start, End] from Val shifted Start bits.
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// For instance, getBits(0xF0, 4, 8) returns 0xF.
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static uint64_t getBits(uint64_t Val, int Start, int End) {
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uint64_t Mask = ((uint64_t)1 << (End + 1 - Start)) - 1;
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return (Val >> Start) & Mask;
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}
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namespace {
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template <class ELFT> class DyldELFObject : public ELFObjectFile<ELFT> {
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LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
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typedef Elf_Shdr_Impl<ELFT> Elf_Shdr;
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typedef Elf_Sym_Impl<ELFT> Elf_Sym;
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typedef Elf_Rel_Impl<ELFT, false> Elf_Rel;
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typedef Elf_Rel_Impl<ELFT, true> Elf_Rela;
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typedef Elf_Ehdr_Impl<ELFT> Elf_Ehdr;
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typedef typename ELFDataTypeTypedefHelper<ELFT>::value_type addr_type;
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public:
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DyldELFObject(MemoryBufferRef Wrapper, std::error_code &ec);
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void updateSectionAddress(const SectionRef &Sec, uint64_t Addr);
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void updateSymbolAddress(const SymbolRef &SymRef, uint64_t Addr);
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// Methods for type inquiry through isa, cast and dyn_cast
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static inline bool classof(const Binary *v) {
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return (isa<ELFObjectFile<ELFT>>(v) &&
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classof(cast<ELFObjectFile<ELFT>>(v)));
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}
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static inline bool classof(const ELFObjectFile<ELFT> *v) {
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return v->isDyldType();
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}
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};
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// The MemoryBuffer passed into this constructor is just a wrapper around the
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// actual memory. Ultimately, the Binary parent class will take ownership of
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// this MemoryBuffer object but not the underlying memory.
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template <class ELFT>
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DyldELFObject<ELFT>::DyldELFObject(MemoryBufferRef Wrapper, std::error_code &EC)
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: ELFObjectFile<ELFT>(Wrapper, EC) {
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this->isDyldELFObject = true;
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}
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template <class ELFT>
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void DyldELFObject<ELFT>::updateSectionAddress(const SectionRef &Sec,
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uint64_t Addr) {
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DataRefImpl ShdrRef = Sec.getRawDataRefImpl();
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Elf_Shdr *shdr =
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const_cast<Elf_Shdr *>(reinterpret_cast<const Elf_Shdr *>(ShdrRef.p));
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// This assumes the address passed in matches the target address bitness
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// The template-based type cast handles everything else.
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shdr->sh_addr = static_cast<addr_type>(Addr);
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}
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template <class ELFT>
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void DyldELFObject<ELFT>::updateSymbolAddress(const SymbolRef &SymRef,
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uint64_t Addr) {
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Elf_Sym *sym = const_cast<Elf_Sym *>(
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ELFObjectFile<ELFT>::getSymbol(SymRef.getRawDataRefImpl()));
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// This assumes the address passed in matches the target address bitness
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// The template-based type cast handles everything else.
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sym->st_value = static_cast<addr_type>(Addr);
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}
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class LoadedELFObjectInfo final
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: public RuntimeDyld::LoadedObjectInfoHelper<LoadedELFObjectInfo> {
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public:
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LoadedELFObjectInfo(RuntimeDyldImpl &RTDyld, ObjSectionToIDMap ObjSecToIDMap)
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: LoadedObjectInfoHelper(RTDyld, std::move(ObjSecToIDMap)) {}
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OwningBinary<ObjectFile>
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getObjectForDebug(const ObjectFile &Obj) const override;
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};
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template <typename ELFT>
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std::unique_ptr<DyldELFObject<ELFT>>
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createRTDyldELFObject(MemoryBufferRef Buffer,
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const ObjectFile &SourceObject,
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const LoadedELFObjectInfo &L,
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std::error_code &ec) {
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typedef typename ELFFile<ELFT>::Elf_Shdr Elf_Shdr;
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typedef typename ELFDataTypeTypedefHelper<ELFT>::value_type addr_type;
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std::unique_ptr<DyldELFObject<ELFT>> Obj =
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llvm::make_unique<DyldELFObject<ELFT>>(Buffer, ec);
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// Iterate over all sections in the object.
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auto SI = SourceObject.section_begin();
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for (const auto &Sec : Obj->sections()) {
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StringRef SectionName;
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Sec.getName(SectionName);
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if (SectionName != "") {
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DataRefImpl ShdrRef = Sec.getRawDataRefImpl();
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Elf_Shdr *shdr = const_cast<Elf_Shdr *>(
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reinterpret_cast<const Elf_Shdr *>(ShdrRef.p));
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if (uint64_t SecLoadAddr = L.getSectionLoadAddress(*SI)) {
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// This assumes that the address passed in matches the target address
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// bitness. The template-based type cast handles everything else.
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shdr->sh_addr = static_cast<addr_type>(SecLoadAddr);
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}
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}
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++SI;
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}
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return Obj;
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}
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OwningBinary<ObjectFile> createELFDebugObject(const ObjectFile &Obj,
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const LoadedELFObjectInfo &L) {
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assert(Obj.isELF() && "Not an ELF object file.");
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std::unique_ptr<MemoryBuffer> Buffer =
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MemoryBuffer::getMemBufferCopy(Obj.getData(), Obj.getFileName());
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std::error_code ec;
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std::unique_ptr<ObjectFile> DebugObj;
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if (Obj.getBytesInAddress() == 4 && Obj.isLittleEndian()) {
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typedef ELFType<support::little, false> ELF32LE;
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DebugObj = createRTDyldELFObject<ELF32LE>(Buffer->getMemBufferRef(), Obj, L,
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ec);
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} else if (Obj.getBytesInAddress() == 4 && !Obj.isLittleEndian()) {
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typedef ELFType<support::big, false> ELF32BE;
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DebugObj = createRTDyldELFObject<ELF32BE>(Buffer->getMemBufferRef(), Obj, L,
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ec);
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} else if (Obj.getBytesInAddress() == 8 && !Obj.isLittleEndian()) {
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typedef ELFType<support::big, true> ELF64BE;
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DebugObj = createRTDyldELFObject<ELF64BE>(Buffer->getMemBufferRef(), Obj, L,
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ec);
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} else if (Obj.getBytesInAddress() == 8 && Obj.isLittleEndian()) {
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typedef ELFType<support::little, true> ELF64LE;
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DebugObj = createRTDyldELFObject<ELF64LE>(Buffer->getMemBufferRef(), Obj, L,
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ec);
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} else
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llvm_unreachable("Unexpected ELF format");
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assert(!ec && "Could not construct copy ELF object file");
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return OwningBinary<ObjectFile>(std::move(DebugObj), std::move(Buffer));
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}
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OwningBinary<ObjectFile>
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LoadedELFObjectInfo::getObjectForDebug(const ObjectFile &Obj) const {
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return createELFDebugObject(Obj, *this);
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}
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} // anonymous namespace
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namespace llvm {
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RuntimeDyldELF::RuntimeDyldELF(RuntimeDyld::MemoryManager &MemMgr,
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JITSymbolResolver &Resolver)
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: RuntimeDyldImpl(MemMgr, Resolver), GOTSectionID(0), CurrentGOTIndex(0) {}
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RuntimeDyldELF::~RuntimeDyldELF() {}
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void RuntimeDyldELF::registerEHFrames() {
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for (int i = 0, e = UnregisteredEHFrameSections.size(); i != e; ++i) {
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SID EHFrameSID = UnregisteredEHFrameSections[i];
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uint8_t *EHFrameAddr = Sections[EHFrameSID].getAddress();
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uint64_t EHFrameLoadAddr = Sections[EHFrameSID].getLoadAddress();
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size_t EHFrameSize = Sections[EHFrameSID].getSize();
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MemMgr.registerEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
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RegisteredEHFrameSections.push_back(EHFrameSID);
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}
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UnregisteredEHFrameSections.clear();
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}
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void RuntimeDyldELF::deregisterEHFrames() {
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for (int i = 0, e = RegisteredEHFrameSections.size(); i != e; ++i) {
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SID EHFrameSID = RegisteredEHFrameSections[i];
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uint8_t *EHFrameAddr = Sections[EHFrameSID].getAddress();
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uint64_t EHFrameLoadAddr = Sections[EHFrameSID].getLoadAddress();
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size_t EHFrameSize = Sections[EHFrameSID].getSize();
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MemMgr.deregisterEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
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}
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RegisteredEHFrameSections.clear();
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}
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std::unique_ptr<RuntimeDyldELF>
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llvm::RuntimeDyldELF::create(Triple::ArchType Arch,
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RuntimeDyld::MemoryManager &MemMgr,
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JITSymbolResolver &Resolver) {
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switch (Arch) {
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default:
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return make_unique<RuntimeDyldELF>(MemMgr, Resolver);
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case Triple::mips:
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case Triple::mipsel:
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case Triple::mips64:
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case Triple::mips64el:
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return make_unique<RuntimeDyldELFMips>(MemMgr, Resolver);
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}
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}
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std::unique_ptr<RuntimeDyld::LoadedObjectInfo>
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RuntimeDyldELF::loadObject(const object::ObjectFile &O) {
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if (auto ObjSectionToIDOrErr = loadObjectImpl(O))
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return llvm::make_unique<LoadedELFObjectInfo>(*this, *ObjSectionToIDOrErr);
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else {
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HasError = true;
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raw_string_ostream ErrStream(ErrorStr);
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logAllUnhandledErrors(ObjSectionToIDOrErr.takeError(), ErrStream, "");
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return nullptr;
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}
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}
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void RuntimeDyldELF::resolveX86_64Relocation(const SectionEntry &Section,
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uint64_t Offset, uint64_t Value,
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uint32_t Type, int64_t Addend,
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uint64_t SymOffset) {
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switch (Type) {
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default:
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llvm_unreachable("Relocation type not implemented yet!");
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break;
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case ELF::R_X86_64_NONE:
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break;
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case ELF::R_X86_64_64: {
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support::ulittle64_t::ref(Section.getAddressWithOffset(Offset)) =
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Value + Addend;
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DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend)) << " at "
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<< format("%p\n", Section.getAddressWithOffset(Offset)));
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break;
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}
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case ELF::R_X86_64_32:
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case ELF::R_X86_64_32S: {
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Value += Addend;
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assert((Type == ELF::R_X86_64_32 && (Value <= UINT32_MAX)) ||
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(Type == ELF::R_X86_64_32S &&
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((int64_t)Value <= INT32_MAX && (int64_t)Value >= INT32_MIN)));
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uint32_t TruncatedAddr = (Value & 0xFFFFFFFF);
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support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) =
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TruncatedAddr;
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DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr) << " at "
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<< format("%p\n", Section.getAddressWithOffset(Offset)));
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break;
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}
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case ELF::R_X86_64_PC8: {
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uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
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int64_t RealOffset = Value + Addend - FinalAddress;
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assert(isInt<8>(RealOffset));
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int8_t TruncOffset = (RealOffset & 0xFF);
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Section.getAddress()[Offset] = TruncOffset;
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break;
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}
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case ELF::R_X86_64_PC32: {
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uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
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int64_t RealOffset = Value + Addend - FinalAddress;
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assert(isInt<32>(RealOffset));
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int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
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support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) =
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TruncOffset;
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break;
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}
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case ELF::R_X86_64_PC64: {
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uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
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int64_t RealOffset = Value + Addend - FinalAddress;
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support::ulittle64_t::ref(Section.getAddressWithOffset(Offset)) =
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RealOffset;
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break;
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}
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}
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}
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void RuntimeDyldELF::resolveX86Relocation(const SectionEntry &Section,
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uint64_t Offset, uint32_t Value,
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uint32_t Type, int32_t Addend) {
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switch (Type) {
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case ELF::R_386_32: {
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support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) =
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Value + Addend;
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break;
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}
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case ELF::R_386_PC32: {
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uint32_t FinalAddress =
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Section.getLoadAddressWithOffset(Offset) & 0xFFFFFFFF;
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uint32_t RealOffset = Value + Addend - FinalAddress;
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support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) =
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RealOffset;
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break;
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}
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default:
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// There are other relocation types, but it appears these are the
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// only ones currently used by the LLVM ELF object writer
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llvm_unreachable("Relocation type not implemented yet!");
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break;
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}
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}
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void RuntimeDyldELF::resolveAArch64Relocation(const SectionEntry &Section,
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uint64_t Offset, uint64_t Value,
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uint32_t Type, int64_t Addend) {
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uint32_t *TargetPtr =
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reinterpret_cast<uint32_t *>(Section.getAddressWithOffset(Offset));
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uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
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// Data should use target endian. Code should always use little endian.
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bool isBE = Arch == Triple::aarch64_be;
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DEBUG(dbgs() << "resolveAArch64Relocation, LocalAddress: 0x"
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<< format("%llx", Section.getAddressWithOffset(Offset))
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<< " FinalAddress: 0x" << format("%llx", FinalAddress)
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<< " Value: 0x" << format("%llx", Value) << " Type: 0x"
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<< format("%x", Type) << " Addend: 0x" << format("%llx", Addend)
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<< "\n");
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switch (Type) {
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default:
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llvm_unreachable("Relocation type not implemented yet!");
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break;
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case ELF::R_AARCH64_ABS64:
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write(isBE, TargetPtr, Value + Addend);
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break;
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case ELF::R_AARCH64_PREL32: {
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uint64_t Result = Value + Addend - FinalAddress;
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assert(static_cast<int64_t>(Result) >= INT32_MIN &&
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static_cast<int64_t>(Result) <= UINT32_MAX);
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write(isBE, TargetPtr, static_cast<uint32_t>(Result & 0xffffffffU));
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break;
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}
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case ELF::R_AARCH64_PREL64:
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write(isBE, TargetPtr, Value + Addend - FinalAddress);
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break;
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case ELF::R_AARCH64_CALL26: // fallthrough
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case ELF::R_AARCH64_JUMP26: {
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// Operation: S+A-P. Set Call or B immediate value to bits fff_fffc of the
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// calculation.
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uint64_t BranchImm = Value + Addend - FinalAddress;
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// "Check that -2^27 <= result < 2^27".
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assert(isInt<28>(BranchImm));
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or32le(TargetPtr, (BranchImm & 0x0FFFFFFC) >> 2);
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break;
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}
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case ELF::R_AARCH64_MOVW_UABS_G3:
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or32le(TargetPtr, ((Value + Addend) & 0xFFFF000000000000) >> 43);
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break;
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case ELF::R_AARCH64_MOVW_UABS_G2_NC:
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or32le(TargetPtr, ((Value + Addend) & 0xFFFF00000000) >> 27);
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break;
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case ELF::R_AARCH64_MOVW_UABS_G1_NC:
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or32le(TargetPtr, ((Value + Addend) & 0xFFFF0000) >> 11);
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break;
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case ELF::R_AARCH64_MOVW_UABS_G0_NC:
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or32le(TargetPtr, ((Value + Addend) & 0xFFFF) << 5);
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break;
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case ELF::R_AARCH64_ADR_PREL_PG_HI21: {
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// Operation: Page(S+A) - Page(P)
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uint64_t Result =
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((Value + Addend) & ~0xfffULL) - (FinalAddress & ~0xfffULL);
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// Check that -2^32 <= X < 2^32
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assert(isInt<33>(Result) && "overflow check failed for relocation");
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// Immediate goes in bits 30:29 + 5:23 of ADRP instruction, taken
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// from bits 32:12 of X.
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write32AArch64Addr(TargetPtr, Result >> 12);
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break;
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}
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case ELF::R_AARCH64_ADD_ABS_LO12_NC:
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// Operation: S + A
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// Immediate goes in bits 21:10 of LD/ST instruction, taken
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// from bits 11:0 of X
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or32AArch64Imm(TargetPtr, Value + Addend);
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break;
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case ELF::R_AARCH64_LDST8_ABS_LO12_NC:
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// Operation: S + A
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// Immediate goes in bits 21:10 of LD/ST instruction, taken
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// from bits 11:0 of X
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or32AArch64Imm(TargetPtr, getBits(Value + Addend, 0, 11));
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break;
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case ELF::R_AARCH64_LDST16_ABS_LO12_NC:
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// Operation: S + A
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// Immediate goes in bits 21:10 of LD/ST instruction, taken
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// from bits 11:1 of X
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or32AArch64Imm(TargetPtr, getBits(Value + Addend, 1, 11));
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break;
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case ELF::R_AARCH64_LDST32_ABS_LO12_NC:
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// Operation: S + A
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// Immediate goes in bits 21:10 of LD/ST instruction, taken
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// 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;
|
|
|
|
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;
|
|
}
|
|
}
|
|
}
|
|
|
|
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:
|
|
llvm_unreachable("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);
|
|
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));
|
|
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) {
|
|
|
|
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);
|
|
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());
|
|
}
|
|
}
|
|
|
|
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)) {
|
|
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.
|
|
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(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(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_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);
|
|
|
|
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::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_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_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
|