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RuntimeDyldELF.cpp
1669 lines (1522 loc) · 65.1 KB
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RuntimeDyldELF.cpp
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//===-- 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;
#define DEBUG_TYPE "dyld"
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);
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: {
uint64_t *TargetPtr =
reinterpret_cast<uint64_t *>(Section.getAddressWithOffset(Offset));
*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);
*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));
// AArch64 code is emitted with .rela relocations. The data already in any
// bits affected by the relocation on entry is garbage.
*TargetPtr &= 0xfc000000U;
// Immediate goes in bits 25:0 of B and BL.
*TargetPtr |= static_cast<uint32_t>(BranchImm & 0xffffffcU) >> 2;
break;
}
case ELF::R_AARCH64_MOVW_UABS_G3: {
uint64_t Result = Value + Addend;
// AArch64 code is emitted with .rela relocations. The data already in any
// bits affected by the relocation on entry is garbage.
*TargetPtr &= 0xffe0001fU;
// Immediate goes in bits 20:5 of MOVZ/MOVK instruction
*TargetPtr |= Result >> (48 - 5);
// Shift must be "lsl #48", in bits 22:21
assert((*TargetPtr >> 21 & 0x3) == 3 && "invalid shift for relocation");
break;
}
case ELF::R_AARCH64_MOVW_UABS_G2_NC: {
uint64_t Result = Value + Addend;
// AArch64 code is emitted with .rela relocations. The data already in any
// bits affected by the relocation on entry is garbage.
*TargetPtr &= 0xffe0001fU;
// Immediate goes in bits 20:5 of MOVZ/MOVK instruction
*TargetPtr |= ((Result & 0xffff00000000ULL) >> (32 - 5));
// Shift must be "lsl #32", in bits 22:21
assert((*TargetPtr >> 21 & 0x3) == 2 && "invalid shift for relocation");
break;
}
case ELF::R_AARCH64_MOVW_UABS_G1_NC: {
uint64_t Result = Value + Addend;
// AArch64 code is emitted with .rela relocations. The data already in any
// bits affected by the relocation on entry is garbage.
*TargetPtr &= 0xffe0001fU;
// Immediate goes in bits 20:5 of MOVZ/MOVK instruction
*TargetPtr |= ((Result & 0xffff0000U) >> (16 - 5));
// Shift must be "lsl #16", in bits 22:2
assert((*TargetPtr >> 21 & 0x3) == 1 && "invalid shift for relocation");
break;
}
case ELF::R_AARCH64_MOVW_UABS_G0_NC: {
uint64_t Result = Value + Addend;
// AArch64 code is emitted with .rela relocations. The data already in any
// bits affected by the relocation on entry is garbage.
*TargetPtr &= 0xffe0001fU;
// Immediate goes in bits 20:5 of MOVZ/MOVK instruction
*TargetPtr |= ((Result & 0xffffU) << 5);
// Shift must be "lsl #0", in bits 22:21.
assert((*TargetPtr >> 21 & 0x3) == 0 && "invalid shift for relocation");
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");
// AArch64 code is emitted with .rela relocations. The data already in any
// bits affected by the relocation on entry is garbage.
*TargetPtr &= 0x9f00001fU;
// Immediate goes in bits 30:29 + 5:23 of ADRP instruction, taken
// from bits 32:12 of X.
*TargetPtr |= ((Result & 0x3000U) << (29 - 12));
*TargetPtr |= ((Result & 0x1ffffc000ULL) >> (14 - 5));
break;
}
case ELF::R_AARCH64_LDST32_ABS_LO12_NC: {
// Operation: S + A
uint64_t Result = Value + Addend;
// AArch64 code is emitted with .rela relocations. The data already in any
// bits affected by the relocation on entry is garbage.
*TargetPtr &= 0xffc003ffU;
// Immediate goes in bits 21:10 of LD/ST instruction, taken
// from bits 11:2 of X
*TargetPtr |= ((Result & 0xffc) << (10 - 2));
break;
}
case ELF::R_AARCH64_LDST64_ABS_LO12_NC: {
// Operation: S + A
uint64_t Result = Value + Addend;
// AArch64 code is emitted with .rela relocations. The data already in any
// bits affected by the relocation on entry is garbage.
*TargetPtr &= 0xffc003ffU;
// Immediate goes in bits 21:10 of LD/ST instruction, taken
// from bits 11:3 of X
*TargetPtr |= ((Result & 0xff8) << (10 - 3));
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;
}
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;