382 lines · cpp
1//===-- RuntimeDyldMachO.cpp - Run-time dynamic linker for MC-JIT -*- C++ -*-=//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8//9// Implementation of the MC-JIT runtime dynamic linker.10//11//===----------------------------------------------------------------------===//12 13#include "RuntimeDyldMachO.h"14#include "Targets/RuntimeDyldMachOAArch64.h"15#include "Targets/RuntimeDyldMachOARM.h"16#include "Targets/RuntimeDyldMachOI386.h"17#include "Targets/RuntimeDyldMachOX86_64.h"18#include "llvm/ADT/StringRef.h"19 20using namespace llvm;21using namespace llvm::object;22 23#define DEBUG_TYPE "dyld"24 25namespace {26 27class LoadedMachOObjectInfo final28 : public LoadedObjectInfoHelper<LoadedMachOObjectInfo,29 RuntimeDyld::LoadedObjectInfo> {30public:31 LoadedMachOObjectInfo(RuntimeDyldImpl &RTDyld,32 ObjSectionToIDMap ObjSecToIDMap)33 : LoadedObjectInfoHelper(RTDyld, std::move(ObjSecToIDMap)) {}34 35 OwningBinary<ObjectFile>36 getObjectForDebug(const ObjectFile &Obj) const override {37 return OwningBinary<ObjectFile>();38 }39};40 41}42 43namespace llvm {44 45int64_t RuntimeDyldMachO::memcpyAddend(const RelocationEntry &RE) const {46 unsigned NumBytes = 1 << RE.Size;47 uint8_t *Src = Sections[RE.SectionID].getAddress() + RE.Offset;48 49 return static_cast<int64_t>(readBytesUnaligned(Src, NumBytes));50}51 52Expected<relocation_iterator>53RuntimeDyldMachO::processScatteredVANILLA(54 unsigned SectionID, relocation_iterator RelI,55 const ObjectFile &BaseObjT,56 RuntimeDyldMachO::ObjSectionToIDMap &ObjSectionToID,57 bool TargetIsLocalThumbFunc) {58 const MachOObjectFile &Obj =59 static_cast<const MachOObjectFile&>(BaseObjT);60 MachO::any_relocation_info RE =61 Obj.getRelocation(RelI->getRawDataRefImpl());62 63 SectionEntry &Section = Sections[SectionID];64 uint32_t RelocType = Obj.getAnyRelocationType(RE);65 bool IsPCRel = Obj.getAnyRelocationPCRel(RE);66 unsigned Size = Obj.getAnyRelocationLength(RE);67 uint64_t Offset = RelI->getOffset();68 uint8_t *LocalAddress = Section.getAddressWithOffset(Offset);69 unsigned NumBytes = 1 << Size;70 int64_t Addend = readBytesUnaligned(LocalAddress, NumBytes);71 72 unsigned SymbolBaseAddr = Obj.getScatteredRelocationValue(RE);73 section_iterator TargetSI = getSectionByAddress(Obj, SymbolBaseAddr);74 assert(TargetSI != Obj.section_end() && "Can't find section for symbol");75 uint64_t SectionBaseAddr = TargetSI->getAddress();76 SectionRef TargetSection = *TargetSI;77 bool IsCode = TargetSection.isText();78 uint32_t TargetSectionID = ~0U;79 if (auto TargetSectionIDOrErr =80 findOrEmitSection(Obj, TargetSection, IsCode, ObjSectionToID))81 TargetSectionID = *TargetSectionIDOrErr;82 else83 return TargetSectionIDOrErr.takeError();84 85 Addend -= SectionBaseAddr;86 RelocationEntry R(SectionID, Offset, RelocType, Addend, IsPCRel, Size);87 R.IsTargetThumbFunc = TargetIsLocalThumbFunc;88 89 addRelocationForSection(R, TargetSectionID);90 91 return ++RelI;92}93 94 95Expected<RelocationValueRef>96RuntimeDyldMachO::getRelocationValueRef(97 const ObjectFile &BaseTObj, const relocation_iterator &RI,98 const RelocationEntry &RE, ObjSectionToIDMap &ObjSectionToID) {99 100 const MachOObjectFile &Obj =101 static_cast<const MachOObjectFile &>(BaseTObj);102 MachO::any_relocation_info RelInfo =103 Obj.getRelocation(RI->getRawDataRefImpl());104 RelocationValueRef Value;105 106 bool IsExternal = Obj.getPlainRelocationExternal(RelInfo);107 if (IsExternal) {108 symbol_iterator Symbol = RI->getSymbol();109 StringRef TargetName;110 if (auto TargetNameOrErr = Symbol->getName())111 TargetName = *TargetNameOrErr;112 else113 return TargetNameOrErr.takeError();114 RTDyldSymbolTable::const_iterator SI =115 GlobalSymbolTable.find(TargetName.data());116 if (SI != GlobalSymbolTable.end()) {117 const auto &SymInfo = SI->second;118 Value.SectionID = SymInfo.getSectionID();119 Value.Offset = SymInfo.getOffset() + RE.Addend;120 } else {121 Value.SymbolName = TargetName.data();122 Value.Offset = RE.Addend;123 }124 } else {125 SectionRef Sec = Obj.getAnyRelocationSection(RelInfo);126 bool IsCode = Sec.isText();127 if (auto SectionIDOrErr = findOrEmitSection(Obj, Sec, IsCode,128 ObjSectionToID))129 Value.SectionID = *SectionIDOrErr;130 else131 return SectionIDOrErr.takeError();132 uint64_t Addr = Sec.getAddress();133 Value.Offset = RE.Addend - Addr;134 }135 136 return Value;137}138 139void RuntimeDyldMachO::makeValueAddendPCRel(RelocationValueRef &Value,140 const relocation_iterator &RI,141 unsigned OffsetToNextPC) {142 auto &O = *cast<MachOObjectFile>(RI->getObject());143 section_iterator SecI = O.getRelocationRelocatedSection(RI);144 Value.Offset += RI->getOffset() + OffsetToNextPC + SecI->getAddress();145}146 147void RuntimeDyldMachO::dumpRelocationToResolve(const RelocationEntry &RE,148 uint64_t Value) const {149 const SectionEntry &Section = Sections[RE.SectionID];150 uint8_t *LocalAddress = Section.getAddress() + RE.Offset;151 uint64_t FinalAddress = Section.getLoadAddress() + RE.Offset;152 153 dbgs() << "resolveRelocation Section: " << RE.SectionID154 << " LocalAddress: " << format("%p", LocalAddress)155 << " FinalAddress: " << format("0x%016" PRIx64, FinalAddress)156 << " Value: " << format("0x%016" PRIx64, Value) << " Addend: " << RE.Addend157 << " isPCRel: " << RE.IsPCRel << " MachoType: " << RE.RelType158 << " Size: " << (1 << RE.Size) << "\n";159}160 161section_iterator162RuntimeDyldMachO::getSectionByAddress(const MachOObjectFile &Obj,163 uint64_t Addr) {164 section_iterator SI = Obj.section_begin();165 section_iterator SE = Obj.section_end();166 167 for (; SI != SE; ++SI) {168 uint64_t SAddr = SI->getAddress();169 uint64_t SSize = SI->getSize();170 if ((Addr >= SAddr) && (Addr < SAddr + SSize))171 return SI;172 }173 174 return SE;175}176 177 178// Populate __pointers section.179Error RuntimeDyldMachO::populateIndirectSymbolPointersSection(180 const MachOObjectFile &Obj,181 const SectionRef &PTSection,182 unsigned PTSectionID) {183 assert(!Obj.is64Bit() &&184 "Pointer table section not supported in 64-bit MachO.");185 186 MachO::dysymtab_command DySymTabCmd = Obj.getDysymtabLoadCommand();187 MachO::section Sec32 = Obj.getSection(PTSection.getRawDataRefImpl());188 uint32_t PTSectionSize = Sec32.size;189 unsigned FirstIndirectSymbol = Sec32.reserved1;190 const unsigned PTEntrySize = 4;191 unsigned NumPTEntries = PTSectionSize / PTEntrySize;192 unsigned PTEntryOffset = 0;193 194 assert((PTSectionSize % PTEntrySize) == 0 &&195 "Pointers section does not contain a whole number of stubs?");196 197 LLVM_DEBUG(dbgs() << "Populating pointer table section "198 << Sections[PTSectionID].getName() << ", Section ID "199 << PTSectionID << ", " << NumPTEntries << " entries, "200 << PTEntrySize << " bytes each:\n");201 202 for (unsigned i = 0; i < NumPTEntries; ++i) {203 unsigned SymbolIndex =204 Obj.getIndirectSymbolTableEntry(DySymTabCmd, FirstIndirectSymbol + i);205 symbol_iterator SI = Obj.getSymbolByIndex(SymbolIndex);206 StringRef IndirectSymbolName;207 if (auto IndirectSymbolNameOrErr = SI->getName())208 IndirectSymbolName = *IndirectSymbolNameOrErr;209 else210 return IndirectSymbolNameOrErr.takeError();211 LLVM_DEBUG(dbgs() << " " << IndirectSymbolName << ": index " << SymbolIndex212 << ", PT offset: " << PTEntryOffset << "\n");213 RelocationEntry RE(PTSectionID, PTEntryOffset,214 MachO::GENERIC_RELOC_VANILLA, 0, false, 2);215 addRelocationForSymbol(RE, IndirectSymbolName);216 PTEntryOffset += PTEntrySize;217 }218 return Error::success();219}220 221bool RuntimeDyldMachO::isCompatibleFile(const object::ObjectFile &Obj) const {222 return Obj.isMachO();223}224 225template <typename Impl>226Error227RuntimeDyldMachOCRTPBase<Impl>::finalizeLoad(const ObjectFile &Obj,228 ObjSectionToIDMap &SectionMap) {229 unsigned EHFrameSID = RTDYLD_INVALID_SECTION_ID;230 unsigned TextSID = RTDYLD_INVALID_SECTION_ID;231 unsigned ExceptTabSID = RTDYLD_INVALID_SECTION_ID;232 233 for (const auto &Section : Obj.sections()) {234 StringRef Name;235 if (Expected<StringRef> NameOrErr = Section.getName())236 Name = *NameOrErr;237 else238 consumeError(NameOrErr.takeError());239 240 // Force emission of the __text, __eh_frame, and __gcc_except_tab sections241 // if they're present. Otherwise call down to the impl to handle other242 // sections that have already been emitted.243 if (Name == "__text") {244 if (auto TextSIDOrErr = findOrEmitSection(Obj, Section, true, SectionMap))245 TextSID = *TextSIDOrErr;246 else247 return TextSIDOrErr.takeError();248 } else if (Name == "__eh_frame") {249 if (auto EHFrameSIDOrErr = findOrEmitSection(Obj, Section, false,250 SectionMap))251 EHFrameSID = *EHFrameSIDOrErr;252 else253 return EHFrameSIDOrErr.takeError();254 } else if (Name == "__gcc_except_tab") {255 if (auto ExceptTabSIDOrErr = findOrEmitSection(Obj, Section, true,256 SectionMap))257 ExceptTabSID = *ExceptTabSIDOrErr;258 else259 return ExceptTabSIDOrErr.takeError();260 } else {261 auto I = SectionMap.find(Section);262 if (I != SectionMap.end())263 if (auto Err = impl().finalizeSection(Obj, I->second, Section))264 return Err;265 }266 }267 UnregisteredEHFrameSections.push_back(268 EHFrameRelatedSections(EHFrameSID, TextSID, ExceptTabSID));269 270 return Error::success();271}272 273template <typename Impl>274unsigned char *RuntimeDyldMachOCRTPBase<Impl>::processFDE(uint8_t *P,275 int64_t DeltaForText,276 int64_t DeltaForEH) {277 typedef typename Impl::TargetPtrT TargetPtrT;278 279 LLVM_DEBUG(dbgs() << "Processing FDE: Delta for text: " << DeltaForText280 << ", Delta for EH: " << DeltaForEH << "\n");281 uint32_t Length = readBytesUnaligned(P, 4);282 P += 4;283 uint8_t *Ret = P + Length;284 uint32_t Offset = readBytesUnaligned(P, 4);285 if (Offset == 0) // is a CIE286 return Ret;287 288 P += 4;289 TargetPtrT FDELocation = readBytesUnaligned(P, sizeof(TargetPtrT));290 TargetPtrT NewLocation = FDELocation - DeltaForText;291 writeBytesUnaligned(NewLocation, P, sizeof(TargetPtrT));292 293 P += sizeof(TargetPtrT);294 295 // Skip the FDE address range296 P += sizeof(TargetPtrT);297 298 uint8_t Augmentationsize = *P;299 P += 1;300 if (Augmentationsize != 0) {301 TargetPtrT LSDA = readBytesUnaligned(P, sizeof(TargetPtrT));302 TargetPtrT NewLSDA = LSDA - DeltaForEH;303 writeBytesUnaligned(NewLSDA, P, sizeof(TargetPtrT));304 }305 306 return Ret;307}308 309static int64_t computeDelta(SectionEntry *A, SectionEntry *B) {310 int64_t ObjDistance = static_cast<int64_t>(A->getObjAddress()) -311 static_cast<int64_t>(B->getObjAddress());312 int64_t MemDistance = A->getLoadAddress() - B->getLoadAddress();313 return ObjDistance - MemDistance;314}315 316template <typename Impl>317void RuntimeDyldMachOCRTPBase<Impl>::registerEHFrames() {318 319 for (int i = 0, e = UnregisteredEHFrameSections.size(); i != e; ++i) {320 EHFrameRelatedSections &SectionInfo = UnregisteredEHFrameSections[i];321 if (SectionInfo.EHFrameSID == RTDYLD_INVALID_SECTION_ID ||322 SectionInfo.TextSID == RTDYLD_INVALID_SECTION_ID)323 continue;324 SectionEntry *Text = &Sections[SectionInfo.TextSID];325 SectionEntry *EHFrame = &Sections[SectionInfo.EHFrameSID];326 SectionEntry *ExceptTab = nullptr;327 if (SectionInfo.ExceptTabSID != RTDYLD_INVALID_SECTION_ID)328 ExceptTab = &Sections[SectionInfo.ExceptTabSID];329 330 int64_t DeltaForText = computeDelta(Text, EHFrame);331 int64_t DeltaForEH = 0;332 if (ExceptTab)333 DeltaForEH = computeDelta(ExceptTab, EHFrame);334 335 uint8_t *P = EHFrame->getAddress();336 uint8_t *End = P + EHFrame->getSize();337 while (P != End) {338 P = processFDE(P, DeltaForText, DeltaForEH);339 }340 341 MemMgr.registerEHFrames(EHFrame->getAddress(), EHFrame->getLoadAddress(),342 EHFrame->getSize());343 }344 UnregisteredEHFrameSections.clear();345}346 347std::unique_ptr<RuntimeDyldMachO>348RuntimeDyldMachO::create(Triple::ArchType Arch,349 RuntimeDyld::MemoryManager &MemMgr,350 JITSymbolResolver &Resolver) {351 switch (Arch) {352 default:353 llvm_unreachable("Unsupported target for RuntimeDyldMachO.");354 break;355 case Triple::arm:356 return std::make_unique<RuntimeDyldMachOARM>(MemMgr, Resolver);357 case Triple::aarch64:358 return std::make_unique<RuntimeDyldMachOAArch64>(MemMgr, Resolver);359 case Triple::aarch64_32:360 return std::make_unique<RuntimeDyldMachOAArch64>(MemMgr, Resolver);361 case Triple::x86:362 return std::make_unique<RuntimeDyldMachOI386>(MemMgr, Resolver);363 case Triple::x86_64:364 return std::make_unique<RuntimeDyldMachOX86_64>(MemMgr, Resolver);365 }366}367 368std::unique_ptr<RuntimeDyld::LoadedObjectInfo>369RuntimeDyldMachO::loadObject(const object::ObjectFile &O) {370 if (auto ObjSectionToIDOrErr = loadObjectImpl(O))371 return std::make_unique<LoadedMachOObjectInfo>(*this,372 *ObjSectionToIDOrErr);373 else {374 HasError = true;375 raw_string_ostream ErrStream(ErrorStr);376 logAllUnhandledErrors(ObjSectionToIDOrErr.takeError(), ErrStream);377 return nullptr;378 }379}380 381} // end namespace llvm382