From 35fdeb7b373e416ff00c54abef12e786963af725 Mon Sep 17 00:00:00 2001 From: Jim Grosbach Date: Fri, 18 Mar 2011 18:54:32 +0000 Subject: Add llvm-rtdyld support for loading 32-bit code. Factor out the 64-bit specific bits into a helper function and add an equivalent that loads the 32-bit sections. This allows using llvm-rtdyld on ARM. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127892 91177308-0d34-0410-b5e6-96231b3b80d8 --- tools/llvm-rtdyld/llvm-rtdyld.cpp | 224 +++++++++++++++++++++++++++----------- 1 file changed, 158 insertions(+), 66 deletions(-) (limited to 'tools/llvm-rtdyld') diff --git a/tools/llvm-rtdyld/llvm-rtdyld.cpp b/tools/llvm-rtdyld/llvm-rtdyld.cpp index 42b6f633f1..6de5742a6a 100644 --- a/tools/llvm-rtdyld/llvm-rtdyld.cpp +++ b/tools/llvm-rtdyld/llvm-rtdyld.cpp @@ -51,87 +51,96 @@ static int Error(const Twine &Msg) { } /* *** */ +static bool +loadSegment32(const MachOObject *Obj, + sys::MemoryBlock &Data, + const MachOObject::LoadCommandInfo *SegmentLCI, + const InMemoryStruct &SymtabLC, + StringMap &SymbolTable) { + InMemoryStruct Segment32LC; + Obj->ReadSegmentLoadCommand(*SegmentLCI, Segment32LC); + if (!Segment32LC) + return Error("unable to load segment load command"); -static int executeInput() { - // Load the input memory buffer. - OwningPtr InputBuffer; - if (error_code ec = MemoryBuffer::getFileOrSTDIN(InputFile, InputBuffer)) - return Error("unable to read input: '" + ec.message() + "'"); - - // Load the Mach-O wrapper object. + // Map the segment into memory. std::string ErrorStr; - OwningPtr Obj( - MachOObject::LoadFromBuffer(InputBuffer.take(), &ErrorStr)); - if (!Obj) - return Error("unable to load object: '" + ErrorStr + "'"); + Data = sys::Memory::AllocateRWX(Segment32LC->VMSize, 0, &ErrorStr); + if (!Data.base()) + return Error("unable to allocate memory block: '" + ErrorStr + "'"); + memcpy(Data.base(), Obj->getData(Segment32LC->FileOffset, + Segment32LC->FileSize).data(), + Segment32LC->FileSize); + memset((char*)Data.base() + Segment32LC->FileSize, 0, + Segment32LC->VMSize - Segment32LC->FileSize); - // Validate that the load commands match what we expect. - const MachOObject::LoadCommandInfo *SegmentLCI = 0, *SymtabLCI = 0, - *DysymtabLCI = 0; - for (unsigned i = 0; i != Obj->getHeader().NumLoadCommands; ++i) { - const MachOObject::LoadCommandInfo &LCI = Obj->getLoadCommandInfo(i); - switch (LCI.Command.Type) { - case macho::LCT_Segment: - case macho::LCT_Segment64: - if (SegmentLCI) - return Error("unexpected input object (multiple segments)"); - SegmentLCI = &LCI; - break; - case macho::LCT_Symtab: - if (SymtabLCI) - return Error("unexpected input object (multiple symbol tables)"); - SymtabLCI = &LCI; - break; - case macho::LCT_Dysymtab: - if (DysymtabLCI) - return Error("unexpected input object (multiple symbol tables)"); - DysymtabLCI = &LCI; - break; - default: - return Error("unexpected input object (unexpected load command"); - } + // Bind the section indices to address. + void **SectionBases = new void*[Segment32LC->NumSections]; + for (unsigned i = 0; i != Segment32LC->NumSections; ++i) { + InMemoryStruct Sect; + Obj->ReadSection(*SegmentLCI, i, Sect); + if (!Sect) + return Error("unable to load section: '" + Twine(i) + "'"); + + // FIXME: We don't support relocations yet. + if (Sect->NumRelocationTableEntries != 0) + return Error("not yet implemented: relocations!"); + + // FIXME: Improve check. + if (Sect->Flags != 0x80000400) + return Error("unsupported section type!"); + + SectionBases[i] = (char*) Data.base() + Sect->Address; } - if (!SymtabLCI) - return Error("no symbol table found in object"); - if (!SegmentLCI) - return Error("no symbol table found in object"); + // Bind all the symbols to address. + for (unsigned i = 0; i != SymtabLC->NumSymbolTableEntries; ++i) { + InMemoryStruct STE; + Obj->ReadSymbolTableEntry(SymtabLC->SymbolTableOffset, i, STE); + if (!STE) + return Error("unable to read symbol: '" + Twine(i) + "'"); + if (STE->SectionIndex == 0) + return Error("unexpected undefined symbol!"); - // Read and register the symbol table data. - InMemoryStruct SymtabLC; - Obj->ReadSymtabLoadCommand(*SymtabLCI, SymtabLC); - if (!SymtabLC) - return Error("unable to load symbol table load command"); - Obj->RegisterStringTable(*SymtabLC); + unsigned Index = STE->SectionIndex - 1; + if (Index >= Segment32LC->NumSections) + return Error("invalid section index for symbol: '" + Twine() + "'"); - // Read the dynamic link-edit information, if present (not present in static - // objects). - if (DysymtabLCI) { - InMemoryStruct DysymtabLC; - Obj->ReadDysymtabLoadCommand(*DysymtabLCI, DysymtabLC); - if (!DysymtabLC) - return Error("unable to load dynamic link-exit load command"); + // Get the symbol name. + StringRef Name = Obj->getStringAtIndex(STE->StringIndex); - // FIXME: We don't support anything interesting yet. - if (DysymtabLC->LocalSymbolsIndex != 0) - return Error("NOT YET IMPLEMENTED: local symbol entries"); - if (DysymtabLC->ExternalSymbolsIndex != 0) - return Error("NOT YET IMPLEMENTED: non-external symbol entries"); - if (DysymtabLC->UndefinedSymbolsIndex != SymtabLC->NumSymbolTableEntries) - return Error("NOT YET IMPLEMENTED: undefined symbol entries"); + // Get the section base address. + void *SectionBase = SectionBases[Index]; + + // Get the symbol address. + void *Address = (char*) SectionBase + STE->Value; + + // FIXME: Check the symbol type and flags. + if (STE->Type != 0xF) + return Error("unexpected symbol type!"); + if (STE->Flags != 0x0) + return Error("unexpected symbol type!"); + + SymbolTable[Name] = Address; } - // Load the segment load command. - if (SegmentLCI->Command.Type != macho::LCT_Segment64) - return Error("Segment32 not yet implemented!"); + delete SectionBases; + return false; +} + +static bool +loadSegment64(const MachOObject *Obj, + sys::MemoryBlock &Data, + const MachOObject::LoadCommandInfo *SegmentLCI, + const InMemoryStruct &SymtabLC, + StringMap &SymbolTable) { InMemoryStruct Segment64LC; Obj->ReadSegment64LoadCommand(*SegmentLCI, Segment64LC); if (!Segment64LC) return Error("unable to load segment load command"); // Map the segment into memory. - sys::MemoryBlock Data = sys::Memory::AllocateRWX(Segment64LC->VMSize, - 0, &ErrorStr); + std::string ErrorStr; + Data = sys::Memory::AllocateRWX(Segment64LC->VMSize, 0, &ErrorStr); if (!Data.base()) return Error("unable to allocate memory block: '" + ErrorStr + "'"); memcpy(Data.base(), Obj->getData(Segment64LC->FileOffset, @@ -160,7 +169,6 @@ static int executeInput() { } // Bind all the symbols to address. - StringMap SymbolTable; for (unsigned i = 0; i != SymtabLC->NumSymbolTableEntries; ++i) { InMemoryStruct STE; Obj->ReadSymbol64TableEntry(SymtabLC->SymbolTableOffset, i, STE); @@ -191,6 +199,90 @@ static int executeInput() { SymbolTable[Name] = Address; } + delete SectionBases; + return false; +} + +static int executeInput() { + // Load the input memory buffer. + OwningPtr InputBuffer; + if (error_code ec = MemoryBuffer::getFileOrSTDIN(InputFile, InputBuffer)) + return Error("unable to read input: '" + ec.message() + "'"); + + // Load the Mach-O wrapper object. + std::string ErrorStr; + OwningPtr Obj( + MachOObject::LoadFromBuffer(InputBuffer.take(), &ErrorStr)); + if (!Obj) + return Error("unable to load object: '" + ErrorStr + "'"); + + // Validate that the load commands match what we expect. + const MachOObject::LoadCommandInfo *SegmentLCI = 0, *SymtabLCI = 0, + *DysymtabLCI = 0; + for (unsigned i = 0; i != Obj->getHeader().NumLoadCommands; ++i) { + const MachOObject::LoadCommandInfo &LCI = Obj->getLoadCommandInfo(i); + switch (LCI.Command.Type) { + case macho::LCT_Segment: + case macho::LCT_Segment64: + if (SegmentLCI) + return Error("unexpected input object (multiple segments)"); + SegmentLCI = &LCI; + break; + case macho::LCT_Symtab: + if (SymtabLCI) + return Error("unexpected input object (multiple symbol tables)"); + SymtabLCI = &LCI; + break; + case macho::LCT_Dysymtab: + if (DysymtabLCI) + return Error("unexpected input object (multiple symbol tables)"); + DysymtabLCI = &LCI; + break; + default: + return Error("unexpected input object (unexpected load command"); + } + } + + if (!SymtabLCI) + return Error("no symbol table found in object"); + if (!SegmentLCI) + return Error("no symbol table found in object"); + + // Read and register the symbol table data. + InMemoryStruct SymtabLC; + Obj->ReadSymtabLoadCommand(*SymtabLCI, SymtabLC); + if (!SymtabLC) + return Error("unable to load symbol table load command"); + Obj->RegisterStringTable(*SymtabLC); + + // Read the dynamic link-edit information, if present (not present in static + // objects). + if (DysymtabLCI) { + InMemoryStruct DysymtabLC; + Obj->ReadDysymtabLoadCommand(*DysymtabLCI, DysymtabLC); + if (!DysymtabLC) + return Error("unable to load dynamic link-exit load command"); + + // FIXME: We don't support anything interesting yet. + if (DysymtabLC->LocalSymbolsIndex != 0) + return Error("NOT YET IMPLEMENTED: local symbol entries"); + if (DysymtabLC->ExternalSymbolsIndex != 0) + return Error("NOT YET IMPLEMENTED: non-external symbol entries"); + if (DysymtabLC->UndefinedSymbolsIndex != SymtabLC->NumSymbolTableEntries) + return Error("NOT YET IMPLEMENTED: undefined symbol entries"); + } + + // Load the segment load command. + sys::MemoryBlock Data; + StringMap SymbolTable; + if (SegmentLCI->Command.Type == macho::LCT_Segment) { + if (loadSegment32(Obj.get(), Data, SegmentLCI, SymtabLC, SymbolTable)) + return true; + } else { + if (loadSegment64(Obj.get(), Data, SegmentLCI, SymtabLC, SymbolTable)) + return true; + } + // Get the address of "_main". StringMap::iterator it = SymbolTable.find("_main"); if (it == SymbolTable.end()) -- cgit v1.2.3