diff options
Diffstat (limited to 'lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp')
| -rw-r--r-- | lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp | 295 |
1 files changed, 270 insertions, 25 deletions
diff --git a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp index 2896c2d..7a2b858 100644 --- a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp +++ b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp @@ -26,45 +26,290 @@ RuntimeDyldImpl::~RuntimeDyldImpl() {} namespace llvm { -void RuntimeDyldImpl::extractFunction(StringRef Name, uint8_t *StartAddress, - uint8_t *EndAddress) { - // FIXME: DEPRECATED in favor of by-section allocation. - // Allocate memory for the function via the memory manager. - uintptr_t Size = EndAddress - StartAddress + 1; - uintptr_t AllocSize = Size; - uint8_t *Mem = MemMgr->startFunctionBody(Name.data(), AllocSize); - assert(Size >= (uint64_t)(EndAddress - StartAddress + 1) && - "Memory manager failed to allocate enough memory!"); - // Copy the function payload into the memory block. - memcpy(Mem, StartAddress, Size); - MemMgr->endFunctionBody(Name.data(), Mem, Mem + Size); - // Remember where we put it. - unsigned SectionID = Sections.size(); - Sections.push_back(sys::MemoryBlock(Mem, Size)); +namespace { + // Helper for extensive error checking in debug builds. + error_code Check(error_code Err) { + if (Err) { + report_fatal_error(Err.message()); + } + return Err; + } +} // end anonymous namespace - // Default the assigned address for this symbol to wherever this - // allocated it. - SymbolTable[Name] = SymbolLoc(SectionID, 0); - DEBUG(dbgs() << " allocated to [" << Mem << ", " << Mem + Size << "]\n"); -} // Resolve the relocations for all symbols we currently know about. void RuntimeDyldImpl::resolveRelocations() { + // First, resolve relocations assotiated with external symbols. + resolveSymbols(); + // Just iterate over the sections we have and resolve all the relocations // in them. Gross overkill, but it gets the job done. for (int i = 0, e = Sections.size(); i != e; ++i) { - reassignSectionAddress(i, SectionLoadAddress[i]); + reassignSectionAddress(i, Sections[i].LoadAddress); } } void RuntimeDyldImpl::mapSectionAddress(void *LocalAddress, uint64_t TargetAddress) { - assert(SectionLocalMemToID.count(LocalAddress) && - "Attempting to remap address of unknown section!"); - unsigned SectionID = SectionLocalMemToID[LocalAddress]; - reassignSectionAddress(SectionID, TargetAddress); + for (unsigned i = 0, e = Sections.size(); i != e; ++i) { + if (Sections[i].Address == LocalAddress) { + reassignSectionAddress(i, TargetAddress); + return; + } + } + llvm_unreachable("Attempting to remap address of unknown section!"); +} + +bool RuntimeDyldImpl::loadObject(const MemoryBuffer *InputBuffer) { + // FIXME: ObjectFile don't modify MemoryBuffer. + // It should use const MemoryBuffer as parameter. + ObjectFile *obj + = ObjectFile::createObjectFile(const_cast<MemoryBuffer*>(InputBuffer)); + + Arch = (Triple::ArchType)obj->getArch(); + + LocalSymbolMap LocalSymbols; // Functions and data symbols from the + // object file. + ObjSectionToIDMap LocalSections; // Used sections from the object file + + error_code err; + // Parse symbols + DEBUG(dbgs() << "Parse symbols:\n"); + for (symbol_iterator i = obj->begin_symbols(), e = obj->end_symbols(); + i != e; i.increment(err)) { + Check(err); + object::SymbolRef::Type SymType; + StringRef Name; + Check(i->getType(SymType)); + Check(i->getName(Name)); + + if (SymType == object::SymbolRef::ST_Function || + SymType == object::SymbolRef::ST_Data) { + uint64_t FileOffset; + uint32_t flags; + StringRef sData; + section_iterator si = obj->end_sections(); + Check(i->getFileOffset(FileOffset)); + Check(i->getFlags(flags)); + Check(i->getSection(si)); + if (si == obj->end_sections()) continue; + Check(si->getContents(sData)); + const uint8_t* SymPtr = (const uint8_t*)InputBuffer->getBufferStart() + + (uintptr_t)FileOffset; + uintptr_t SectOffset = (uintptr_t)(SymPtr - (const uint8_t*)sData.begin()); + unsigned SectionID + = findOrEmitSection(*si, + SymType == object::SymbolRef::ST_Function, + LocalSections); + bool isGlobal = flags & SymbolRef::SF_Global; + LocalSymbols[Name.data()] = SymbolLoc(SectionID, SectOffset); + DEBUG(dbgs() << "\tFileOffset: " << format("%p", (uintptr_t)FileOffset) + << " flags: " << flags + << " SID: " << SectionID + << " Offset: " << format("%p", SectOffset)); + if (isGlobal) + SymbolTable[Name] = SymbolLoc(SectionID, SectOffset); + } + DEBUG(dbgs() << "\tType: " << SymType << " Name: " << Name << "\n"); + } + + // Parse and proccess relocations + DEBUG(dbgs() << "Parse relocations:\n"); + for (section_iterator si = obj->begin_sections(), + se = obj->end_sections(); si != se; si.increment(err)) { + Check(err); + bool isFirstRelocation = true; + unsigned SectionID = 0; + StubMap Stubs; + + for (relocation_iterator i = si->begin_relocations(), + e = si->end_relocations(); i != e; i.increment(err)) { + Check(err); + + // If it's first relocation in this section, find its SectionID + if (isFirstRelocation) { + SectionID = findOrEmitSection(*si, true, LocalSections); + DEBUG(dbgs() << "\tSectionID: " << SectionID << "\n"); + isFirstRelocation = false; + } + + ObjRelocationInfo RI; + RI.SectionID = SectionID; + Check(i->getAdditionalInfo(RI.AdditionalInfo)); + Check(i->getOffset(RI.Offset)); + Check(i->getSymbol(RI.Symbol)); + Check(i->getType(RI.Type)); + + DEBUG(dbgs() << "\t\tAddend: " << RI.AdditionalInfo + << " Offset: " << format("%p", (uintptr_t)RI.Offset) + << " Type: " << (uint32_t)(RI.Type & 0xffffffffL) + << "\n"); + processRelocationRef(RI, *obj, LocalSections, LocalSymbols, Stubs); + } + } + return false; +} + +unsigned RuntimeDyldImpl::emitSection(const SectionRef &Section, + bool IsCode) { + + unsigned StubBufSize = 0, + StubSize = getMaxStubSize(); + error_code err; + if (StubSize > 0) { + for (relocation_iterator i = Section.begin_relocations(), + e = Section.end_relocations(); i != e; i.increment(err)) + StubBufSize += StubSize; + } + StringRef data; + uint64_t Alignment64; + Check(Section.getContents(data)); + Check(Section.getAlignment(Alignment64)); + + unsigned Alignment = (unsigned)Alignment64 & 0xffffffffL; + unsigned DataSize = data.size(); + unsigned Allocate = DataSize + StubBufSize; + unsigned SectionID = Sections.size(); + const char *pData = data.data(); + uint8_t *Addr = IsCode + ? MemMgr->allocateCodeSection(Allocate, Alignment, SectionID) + : MemMgr->allocateDataSection(Allocate, Alignment, SectionID); + + memcpy(Addr, pData, DataSize); + DEBUG(dbgs() << "emitSection SectionID: " << SectionID + << " obj addr: " << format("%p", pData) + << " new addr: " << format("%p", Addr) + << " DataSize: " << DataSize + << " StubBufSize: " << StubBufSize + << " Allocate: " << Allocate + << "\n"); + Sections.push_back(SectionEntry(Addr, Allocate, DataSize,(uintptr_t)pData)); + return SectionID; +} + +unsigned RuntimeDyldImpl::findOrEmitSection(const SectionRef &Section, + bool IsCode, + ObjSectionToIDMap &LocalSections) { + + unsigned SectionID = 0; + ObjSectionToIDMap::iterator i = LocalSections.find(Section); + if (i != LocalSections.end()) + SectionID = i->second; + else { + SectionID = emitSection(Section, IsCode); + LocalSections[Section] = SectionID; + } + return SectionID; +} + +void RuntimeDyldImpl::AddRelocation(const RelocationValueRef &Value, + unsigned SectionID, uintptr_t Offset, + uint32_t RelType) { + DEBUG(dbgs() << "AddRelocation SymNamePtr: " << format("%p", Value.SymbolName) + << " SID: " << Value.SectionID + << " Addend: " << format("%p", Value.Addend) + << " Offset: " << format("%p", Offset) + << " RelType: " << format("%x", RelType) + << "\n"); + + if (Value.SymbolName == 0) { + Relocations[Value.SectionID].push_back(RelocationEntry( + SectionID, + Offset, + RelType, + Value.Addend)); + } else + SymbolRelocations[Value.SymbolName].push_back(RelocationEntry( + SectionID, + Offset, + RelType, + Value.Addend)); +} + +uint8_t *RuntimeDyldImpl::createStubFunction(uint8_t *Addr) { + // TODO: There is only ARM far stub now. We should add the Thumb stub, + // and stubs for branches Thumb - ARM and ARM - Thumb. + if (Arch == Triple::arm) { + uint32_t *StubAddr = (uint32_t*)Addr; + *StubAddr = 0xe51ff004; // ldr pc,<label> + return (uint8_t*)++StubAddr; + } + else + return Addr; } +// Assign an address to a symbol name and resolve all the relocations +// associated with it. +void RuntimeDyldImpl::reassignSectionAddress(unsigned SectionID, + uint64_t Addr) { + // The address to use for relocation resolution is not + // the address of the local section buffer. We must be doing + // a remote execution environment of some sort. Re-apply any + // relocations referencing this section with the given address. + // + // Addr is a uint64_t because we can't assume the pointer width + // of the target is the same as that of the host. Just use a generic + // "big enough" type. + Sections[SectionID].LoadAddress = Addr; + DEBUG(dbgs() << "Resolving relocations Section #" << SectionID + << "\t" << format("%p", (uint8_t *)Addr) + << "\n"); + resolveRelocationList(Relocations[SectionID], Addr); +} + +void RuntimeDyldImpl::resolveRelocationEntry(const RelocationEntry &RE, + uint64_t Value) { + uint8_t *Target = Sections[RE.SectionID].Address + RE.Offset; + DEBUG(dbgs() << "\tSectionID: " << RE.SectionID + << " + " << RE.Offset << " (" << format("%p", Target) << ")" + << " Data: " << RE.Data + << " Addend: " << RE.Addend + << "\n"); + + resolveRelocation(Target, Sections[RE.SectionID].LoadAddress + RE.Offset, + Value, RE.Data, RE.Addend); +} + +void RuntimeDyldImpl::resolveRelocationList(const RelocationList &Relocs, + uint64_t Value) { + for (unsigned i = 0, e = Relocs.size(); i != e; ++i) { + resolveRelocationEntry(Relocs[i], Value); + } +} + +// resolveSymbols - Resolve any relocations to the specified symbols if +// we know where it lives. +void RuntimeDyldImpl::resolveSymbols() { + StringMap<RelocationList>::iterator i = SymbolRelocations.begin(), + e = SymbolRelocations.end(); + for (; i != e; i++) { + StringRef Name = i->first(); + RelocationList &Relocs = i->second; + StringMap<SymbolLoc>::const_iterator Loc = SymbolTable.find(Name); + if (Loc == SymbolTable.end()) { + // This is an external symbol, try to get it address from + // MemoryManager. + uint8_t *Addr = (uint8_t*) MemMgr->getPointerToNamedFunction(Name.data(), + true); + DEBUG(dbgs() << "Resolving relocations Name: " << Name + << "\t" << format("%p", Addr) + << "\n"); + resolveRelocationList(Relocs, (uintptr_t)Addr); + } else { + // Change the relocation to be section relative rather than symbol + // relative and move it to the resolved relocation list. + DEBUG(dbgs() << "Resolving symbol '" << Name << "'\n"); + for (int i = 0, e = Relocs.size(); i != e; ++i) { + RelocationEntry Entry = Relocs[i]; + Entry.Addend += Loc->second.second; + Relocations[Loc->second.first].push_back(Entry); + } + Relocs.clear(); + } + } +} + + //===----------------------------------------------------------------------===// // RuntimeDyld class implementation RuntimeDyld::RuntimeDyld(RTDyldMemoryManager *mm) { |