diff options
Diffstat (limited to 'lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp')
-rw-r--r-- | lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp | 555 |
1 files changed, 475 insertions, 80 deletions
diff --git a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp index 75bb586..1ebcaf7 100644 --- a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp +++ b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp @@ -12,21 +12,32 @@ //===----------------------------------------------------------------------===// #define DEBUG_TYPE "dyld" +#include "RuntimeDyldELF.h" +#include "JITRegistrar.h" +#include "ObjectImageCommon.h" #include "llvm/ADT/OwningPtr.h" #include "llvm/ADT/StringRef.h" #include "llvm/ADT/STLExtras.h" #include "llvm/ADT/IntervalMap.h" -#include "RuntimeDyldELF.h" #include "llvm/Object/ObjectFile.h" +#include "llvm/ExecutionEngine/ObjectImage.h" +#include "llvm/ExecutionEngine/ObjectBuffer.h" #include "llvm/Support/ELF.h" #include "llvm/ADT/Triple.h" #include "llvm/Object/ELF.h" -#include "JITRegistrar.h" using namespace llvm; using namespace llvm::object; namespace { +static inline +error_code check(error_code Err) { + if (Err) { + report_fatal_error(Err.message()); + } + return Err; +} + template<support::endianness target_endianness, bool is64Bits> class DyldELFObject : public ELFObjectFile<target_endianness, is64Bits> { LLVM_ELF_IMPORT_TYPES(target_endianness, is64Bits) @@ -36,25 +47,17 @@ class DyldELFObject : public ELFObjectFile<target_endianness, is64Bits> { typedef Elf_Rel_Impl<target_endianness, is64Bits, false> Elf_Rel; typedef Elf_Rel_Impl<target_endianness, is64Bits, true> Elf_Rela; - typedef typename ELFObjectFile<target_endianness, is64Bits>:: - Elf_Ehdr Elf_Ehdr; + typedef Elf_Ehdr_Impl<target_endianness, is64Bits> Elf_Ehdr; typedef typename ELFDataTypeTypedefHelper< target_endianness, is64Bits>::value_type addr_type; -protected: - // This duplicates the 'Data' member in the 'Binary' base class - // but it is necessary to workaround a bug in gcc 4.2 - MemoryBuffer *InputData; - public: - DyldELFObject(MemoryBuffer *Object, error_code &ec); + DyldELFObject(MemoryBuffer *Wrapper, error_code &ec); void updateSectionAddress(const SectionRef &Sec, uint64_t Addr); void updateSymbolAddress(const SymbolRef &Sym, uint64_t Addr); - const MemoryBuffer& getBuffer() const { return *InputData; } - // Methods for type inquiry through isa, cast and dyn_cast static inline bool classof(const Binary *v) { return (isa<ELFObjectFile<target_endianness, is64Bits> >(v) @@ -64,20 +67,18 @@ public: const ELFObjectFile<target_endianness, is64Bits> *v) { return v->isDyldType(); } - static inline bool classof(const DyldELFObject *v) { - return true; - } }; template<support::endianness target_endianness, bool is64Bits> -class ELFObjectImage : public ObjectImage { +class ELFObjectImage : public ObjectImageCommon { protected: DyldELFObject<target_endianness, is64Bits> *DyldObj; bool Registered; public: - ELFObjectImage(DyldELFObject<target_endianness, is64Bits> *Obj) - : ObjectImage(Obj), + ELFObjectImage(ObjectBuffer *Input, + DyldELFObject<target_endianness, is64Bits> *Obj) + : ObjectImageCommon(Input, Obj), DyldObj(Obj), Registered(false) {} @@ -100,20 +101,22 @@ class ELFObjectImage : public ObjectImage { virtual void registerWithDebugger() { - JITRegistrar::getGDBRegistrar().registerObject(DyldObj->getBuffer()); + JITRegistrar::getGDBRegistrar().registerObject(*Buffer); Registered = true; } virtual void deregisterWithDebugger() { - JITRegistrar::getGDBRegistrar().deregisterObject(DyldObj->getBuffer()); + JITRegistrar::getGDBRegistrar().deregisterObject(*Buffer); } }; +// 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<support::endianness target_endianness, bool is64Bits> -DyldELFObject<target_endianness, is64Bits>::DyldELFObject(MemoryBuffer *Object, +DyldELFObject<target_endianness, is64Bits>::DyldELFObject(MemoryBuffer *Wrapper, error_code &ec) - : ELFObjectFile<target_endianness, is64Bits>(Object, ec), - InputData(Object) { + : ELFObjectFile<target_endianness, is64Bits>(Wrapper, ec) { this->isDyldELFObject = true; } @@ -149,50 +152,43 @@ void DyldELFObject<target_endianness, is64Bits>::updateSymbolAddress( namespace llvm { -ObjectImage *RuntimeDyldELF::createObjectImage( - const MemoryBuffer *ConstInputBuffer) { - MemoryBuffer *InputBuffer = const_cast<MemoryBuffer*>(ConstInputBuffer); - std::pair<unsigned char, unsigned char> Ident = getElfArchType(InputBuffer); +ObjectImage *RuntimeDyldELF::createObjectImage(ObjectBuffer *Buffer) { + if (Buffer->getBufferSize() < ELF::EI_NIDENT) + llvm_unreachable("Unexpected ELF object size"); + std::pair<unsigned char, unsigned char> Ident = std::make_pair( + (uint8_t)Buffer->getBufferStart()[ELF::EI_CLASS], + (uint8_t)Buffer->getBufferStart()[ELF::EI_DATA]); error_code ec; if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2LSB) { DyldELFObject<support::little, false> *Obj = - new DyldELFObject<support::little, false>(InputBuffer, ec); - return new ELFObjectImage<support::little, false>(Obj); + new DyldELFObject<support::little, false>(Buffer->getMemBuffer(), ec); + return new ELFObjectImage<support::little, false>(Buffer, Obj); } else if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2MSB) { DyldELFObject<support::big, false> *Obj = - new DyldELFObject<support::big, false>(InputBuffer, ec); - return new ELFObjectImage<support::big, false>(Obj); + new DyldELFObject<support::big, false>(Buffer->getMemBuffer(), ec); + return new ELFObjectImage<support::big, false>(Buffer, Obj); } else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2MSB) { DyldELFObject<support::big, true> *Obj = - new DyldELFObject<support::big, true>(InputBuffer, ec); - return new ELFObjectImage<support::big, true>(Obj); + new DyldELFObject<support::big, true>(Buffer->getMemBuffer(), ec); + return new ELFObjectImage<support::big, true>(Buffer, Obj); } else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2LSB) { DyldELFObject<support::little, true> *Obj = - new DyldELFObject<support::little, true>(InputBuffer, ec); - return new ELFObjectImage<support::little, true>(Obj); + new DyldELFObject<support::little, true>(Buffer->getMemBuffer(), ec); + return new ELFObjectImage<support::little, true>(Buffer, Obj); } else llvm_unreachable("Unexpected ELF format"); } -void RuntimeDyldELF::handleObjectLoaded(ObjectImage *Obj) -{ - Obj->registerWithDebugger(); - // Save the loaded object. It will deregister itself when deleted - LoadedObject = Obj; -} - RuntimeDyldELF::~RuntimeDyldELF() { - if (LoadedObject) - delete LoadedObject; } -void RuntimeDyldELF::resolveX86_64Relocation(uint8_t *LocalAddress, - uint64_t FinalAddress, +void RuntimeDyldELF::resolveX86_64Relocation(const SectionEntry &Section, + uint64_t Offset, uint64_t Value, uint32_t Type, int64_t Addend) { @@ -201,8 +197,10 @@ void RuntimeDyldELF::resolveX86_64Relocation(uint8_t *LocalAddress, llvm_unreachable("Relocation type not implemented yet!"); break; case ELF::R_X86_64_64: { - uint64_t *Target = (uint64_t*)(LocalAddress); + uint64_t *Target = reinterpret_cast<uint64_t*>(Section.Address + Offset); *Target = Value + Addend; + DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend)) + << " at " << format("%p\n",Target)); break; } case ELF::R_X86_64_32: @@ -212,37 +210,52 @@ void RuntimeDyldELF::resolveX86_64Relocation(uint8_t *LocalAddress, (Type == ELF::R_X86_64_32S && ((int64_t)Value <= INT32_MAX && (int64_t)Value >= INT32_MIN))); uint32_t TruncatedAddr = (Value & 0xFFFFFFFF); - uint32_t *Target = reinterpret_cast<uint32_t*>(LocalAddress); + uint32_t *Target = reinterpret_cast<uint32_t*>(Section.Address + Offset); *Target = TruncatedAddr; + DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr) + << " at " << format("%p\n",Target)); break; } case ELF::R_X86_64_PC32: { - uint32_t *Placeholder = reinterpret_cast<uint32_t*>(LocalAddress); + // Get the placeholder value from the generated object since + // a previous relocation attempt may have overwritten the loaded version + uint32_t *Placeholder = reinterpret_cast<uint32_t*>(Section.ObjAddress + + Offset); + uint32_t *Target = reinterpret_cast<uint32_t*>(Section.Address + Offset); + uint64_t FinalAddress = Section.LoadAddress + Offset; int64_t RealOffset = *Placeholder + Value + Addend - FinalAddress; assert(RealOffset <= INT32_MAX && RealOffset >= INT32_MIN); int32_t TruncOffset = (RealOffset & 0xFFFFFFFF); - *Placeholder = TruncOffset; + *Target = TruncOffset; break; } } } -void RuntimeDyldELF::resolveX86Relocation(uint8_t *LocalAddress, - uint32_t FinalAddress, +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: { - uint32_t *Target = (uint32_t*)(LocalAddress); - uint32_t Placeholder = *Target; - *Target = Placeholder + Value + Addend; + // Get the placeholder value from the generated object since + // a previous relocation attempt may have overwritten the loaded version + uint32_t *Placeholder = reinterpret_cast<uint32_t*>(Section.ObjAddress + + Offset); + uint32_t *Target = reinterpret_cast<uint32_t*>(Section.Address + Offset); + *Target = *Placeholder + Value + Addend; break; } case ELF::R_386_PC32: { - uint32_t *Placeholder = reinterpret_cast<uint32_t*>(LocalAddress); + // Get the placeholder value from the generated object since + // a previous relocation attempt may have overwritten the loaded version + uint32_t *Placeholder = reinterpret_cast<uint32_t*>(Section.ObjAddress + + Offset); + uint32_t *Target = reinterpret_cast<uint32_t*>(Section.Address + Offset); + uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF); uint32_t RealOffset = *Placeholder + Value + Addend - FinalAddress; - *Placeholder = RealOffset; + *Target = RealOffset; break; } default: @@ -253,16 +266,18 @@ void RuntimeDyldELF::resolveX86Relocation(uint8_t *LocalAddress, } } -void RuntimeDyldELF::resolveARMRelocation(uint8_t *LocalAddress, - uint32_t FinalAddress, +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 = (uint32_t*)LocalAddress; + uint32_t* TargetPtr = (uint32_t*)(Section.Address + Offset); + uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF); Value += Addend; - DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: " << LocalAddress + DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: " + << Section.Address + Offset << " FinalAddress: " << format("%p",FinalAddress) << " Value: " << format("%x",Value) << " Type: " << format("%x",Type) @@ -273,14 +288,19 @@ void RuntimeDyldELF::resolveARMRelocation(uint8_t *LocalAddress, default: llvm_unreachable("Not implemented relocation type!"); - // Just write 32bit value to relocation address + // Write a 32bit value to relocation address, taking into account the + // implicit addend encoded in the target. case ELF::R_ARM_ABS32 : - *TargetPtr = Value; + *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 : + // We are not expecting any other addend in the relocation address. + // Using 0x000F0FFF because MOVW has its 16 bit immediate split into 2 + // non-contiguous fields. + assert((*TargetPtr & 0x000F0FFF) == 0); Value = Value & 0xFFFF; *TargetPtr |= Value & 0xFFF; *TargetPtr |= ((Value >> 12) & 0xF) << 16; @@ -289,6 +309,9 @@ void RuntimeDyldELF::resolveARMRelocation(uint8_t *LocalAddress, // Write last 16 bit of 32 bit value to the mov instruction. // Last 4 bit should be shifted. case ELF::R_ARM_MOVT_ABS : + // We are not expecting any other addend in the relocation address. + // Use 0x000F0FFF for the same reason as R_ARM_MOVW_ABS_NC. + assert((*TargetPtr & 0x000F0FFF) == 0); Value = (Value >> 16) & 0xFFFF; *TargetPtr |= Value & 0xFFF; *TargetPtr |= ((Value >> 12) & 0xF) << 16; @@ -306,26 +329,250 @@ void RuntimeDyldELF::resolveARMRelocation(uint8_t *LocalAddress, } } -void RuntimeDyldELF::resolveRelocation(uint8_t *LocalAddress, - uint64_t FinalAddress, +void RuntimeDyldELF::resolveMIPSRelocation(const SectionEntry &Section, + uint64_t Offset, + uint32_t Value, + uint32_t Type, + int32_t Addend) { + uint32_t* TargetPtr = (uint32_t*)(Section.Address + Offset); + Value += Addend; + + DEBUG(dbgs() << "resolveMipselocation, LocalAddress: " + << Section.Address + Offset + << " FinalAddress: " + << format("%p",Section.LoadAddress + Offset) + << " Value: " << format("%x",Value) + << " Type: " << format("%x",Type) + << " Addend: " << format("%x",Addend) + << "\n"); + + switch(Type) { + default: + llvm_unreachable("Not implemented relocation type!"); + break; + case ELF::R_MIPS_32: + *TargetPtr = Value + (*TargetPtr); + break; + case ELF::R_MIPS_26: + *TargetPtr = ((*TargetPtr) & 0xfc000000) | (( Value & 0x0fffffff) >> 2); + break; + case ELF::R_MIPS_HI16: + // Get the higher 16-bits. Also add 1 if bit 15 is 1. + Value += ((*TargetPtr) & 0x0000ffff) << 16; + *TargetPtr = ((*TargetPtr) & 0xffff0000) | + (((Value + 0x8000) >> 16) & 0xffff); + break; + case ELF::R_MIPS_LO16: + Value += ((*TargetPtr) & 0x0000ffff); + *TargetPtr = ((*TargetPtr) & 0xffff0000) | (Value & 0xffff); + break; + } +} + +// Return the .TOC. section address to R_PPC64_TOC relocations. +uint64_t RuntimeDyldELF::findPPC64TOC() const { + // The TOC consists of sections .got, .toc, .tocbss, .plt in that + // order. The TOC starts where the first of these sections starts. + SectionList::const_iterator it = Sections.begin(); + SectionList::const_iterator ite = Sections.end(); + for (; it != ite; ++it) { + if (it->Name == ".got" || + it->Name == ".toc" || + it->Name == ".tocbss" || + it->Name == ".plt") + break; + } + if (it == ite) { + // 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. + it = Sections.begin(); + } + assert (it != ite); + // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000 + // thus permitting a full 64 Kbytes segment. + return it->LoadAddress + 0x8000; +} + +// Returns the sections and offset associated with the ODP entry referenced +// by Symbol. +void RuntimeDyldELF::findOPDEntrySection(ObjectImage &Obj, + ObjSectionToIDMap &LocalSections, + RelocationValueRef &Rel) { + // Get the ELF symbol value (st_value) to compare with Relocation offset in + // .opd entries + + error_code err; + for (section_iterator si = Obj.begin_sections(), + se = Obj.end_sections(); si != se; si.increment(err)) { + StringRef SectionName; + check(si->getName(SectionName)); + if (SectionName != ".opd") + continue; + + for (relocation_iterator i = si->begin_relocations(), + e = si->end_relocations(); i != e;) { + check(err); + + // The R_PPC64_ADDR64 relocation indicates the first field + // of a .opd entry + uint64_t TypeFunc; + check(i->getType(TypeFunc)); + if (TypeFunc != ELF::R_PPC64_ADDR64) { + i.increment(err); + continue; + } + + SymbolRef TargetSymbol; + uint64_t TargetSymbolOffset; + int64_t TargetAdditionalInfo; + check(i->getSymbol(TargetSymbol)); + check(i->getOffset(TargetSymbolOffset)); + check(i->getAdditionalInfo(TargetAdditionalInfo)); + + i = i.increment(err); + if (i == e) + break; + check(err); + + // Just check if following relocation is a R_PPC64_TOC + uint64_t TypeTOC; + check(i->getType(TypeTOC)); + 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 != (intptr_t)TargetSymbolOffset) + continue; + + section_iterator tsi(Obj.end_sections()); + check(TargetSymbol.getSection(tsi)); + Rel.SectionID = findOrEmitSection(Obj, (*tsi), true, LocalSections); + Rel.Addend = (intptr_t)TargetAdditionalInfo; + return; + } + } + llvm_unreachable("Attempting to get address of ODP entry!"); +} + +// Relocation masks following the #lo(value), #hi(value), #higher(value), +// and #highest(value) macros defined in section 4.5.1. Relocation Types +// in 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 applyPPChigher (uint64_t value) +{ + return (value >> 32) & 0xffff; +} + +static inline +uint16_t applyPPChighest (uint64_t value) +{ + return (value >> 48) & 0xffff; +} + +void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section, + uint64_t Offset, + uint64_t Value, + uint32_t Type, + int64_t Addend) { + uint8_t* LocalAddress = Section.Address + Offset; + switch (Type) { + default: + llvm_unreachable("Relocation type not implemented yet!"); + break; + case ELF::R_PPC64_ADDR16_LO : + writeInt16BE(LocalAddress, applyPPClo (Value + Addend)); + break; + case ELF::R_PPC64_ADDR16_HI : + writeInt16BE(LocalAddress, applyPPChi (Value + Addend)); + break; + case ELF::R_PPC64_ADDR16_HIGHER : + writeInt16BE(LocalAddress, applyPPChigher (Value + Addend)); + break; + case ELF::R_PPC64_ADDR16_HIGHEST : + writeInt16BE(LocalAddress, applyPPChighest (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_REL24 : { + uint64_t FinalAddress = (Section.LoadAddress + Offset); + int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend); + if (SignExtend32<24>(delta) != delta) + llvm_unreachable("Relocation R_PPC64_REL24 overflow"); + // Generates a 'bl <address>' instruction + writeInt32BE(LocalAddress, 0x48000001 | (delta & 0x03FFFFFC)); + } break; + case ELF::R_PPC64_ADDR64 : + writeInt64BE(LocalAddress, Value + Addend); + break; + case ELF::R_PPC64_TOC : + writeInt64BE(LocalAddress, findPPC64TOC()); + break; + case ELF::R_PPC64_TOC16 : { + uint64_t TOCStart = findPPC64TOC(); + Value = applyPPClo((Value + Addend) - TOCStart); + writeInt16BE(LocalAddress, applyPPClo(Value)); + } break; + case ELF::R_PPC64_TOC16_DS : { + uint64_t TOCStart = findPPC64TOC(); + Value = ((Value + Addend) - TOCStart); + writeInt16BE(LocalAddress, applyPPClo(Value)); + } break; + } +} + + +void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section, + uint64_t Offset, uint64_t Value, uint32_t Type, int64_t Addend) { switch (Arch) { case Triple::x86_64: - resolveX86_64Relocation(LocalAddress, FinalAddress, Value, Type, Addend); + resolveX86_64Relocation(Section, Offset, Value, Type, Addend); break; case Triple::x86: - resolveX86Relocation(LocalAddress, (uint32_t)(FinalAddress & 0xffffffffL), + resolveX86Relocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type, (uint32_t)(Addend & 0xffffffffL)); break; case Triple::arm: // Fall through. case Triple::thumb: - resolveARMRelocation(LocalAddress, (uint32_t)(FinalAddress & 0xffffffffL), + resolveARMRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type, (uint32_t)(Addend & 0xffffffffL)); break; + case Triple::mips: // Fall through. + case Triple::mipsel: + resolveMIPSRelocation(Section, Offset, + (uint32_t)(Value & 0xffffffffL), Type, + (uint32_t)(Addend & 0xffffffffL)); + break; + case Triple::ppc64: + resolvePPC64Relocation(Section, Offset, Value, Type, Addend); + break; default: llvm_unreachable("Unsupported CPU type!"); } } @@ -350,6 +597,8 @@ void RuntimeDyldELF::processRelocationRef(const ObjRelocationInfo &Rel, RelocationValueRef Value; // First search for the symbol in the local symbol table SymbolTableMap::const_iterator lsi = Symbols.find(TargetName.data()); + SymbolRef::Type SymType; + Symbol.getType(SymType); if (lsi != Symbols.end()) { Value.SectionID = lsi->second.first; Value.Addend = lsi->second.second; @@ -361,8 +610,6 @@ void RuntimeDyldELF::processRelocationRef(const ObjRelocationInfo &Rel, Value.SectionID = gsi->second.first; Value.Addend = gsi->second.second; } else { - SymbolRef::Type SymType; - Symbol.getType(SymType); switch (SymType) { case SymbolRef::ST_Debug: { // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously @@ -373,7 +620,13 @@ void RuntimeDyldELF::processRelocationRef(const ObjRelocationInfo &Rel, if (si == Obj.end_sections()) llvm_unreachable("Symbol section not found, bad object file format!"); DEBUG(dbgs() << "\t\tThis is section symbol\n"); - Value.SectionID = findOrEmitSection(Obj, (*si), true, ObjSectionToID); + // Default to 'true' in case isText fails (though it never does). + bool isCode = true; + si->isText(isCode); + Value.SectionID = findOrEmitSection(Obj, + (*si), + isCode, + ObjSectionToID); Value.Addend = Addend; break; } @@ -398,13 +651,12 @@ void RuntimeDyldELF::processRelocationRef(const ObjRelocationInfo &Rel, // This is an ARM branch relocation, need to use a stub function. DEBUG(dbgs() << "\t\tThis is an ARM branch relocation."); SectionEntry &Section = Sections[Rel.SectionID]; - uint8_t *Target = Section.Address + Rel.Offset; - // Look up for existing stub. + // Look for an existing stub. StubMap::const_iterator i = Stubs.find(Value); if (i != Stubs.end()) { - resolveRelocation(Target, (uint64_t)Target, (uint64_t)Section.Address + - i->second, RelType, 0); + resolveRelocation(Section, Rel.Offset, + (uint64_t)Section.Address + i->second, RelType, 0); DEBUG(dbgs() << " Stub function found\n"); } else { // Create a new stub function. @@ -419,10 +671,145 @@ void RuntimeDyldELF::processRelocationRef(const ObjRelocationInfo &Rel, else addRelocationForSection(RE, Value.SectionID); - resolveRelocation(Target, (uint64_t)Target, (uint64_t)Section.Address + - Section.StubOffset, RelType, 0); + resolveRelocation(Section, Rel.Offset, + (uint64_t)Section.Address + Section.StubOffset, + RelType, 0); Section.StubOffset += getMaxStubSize(); } + } else if (Arch == Triple::mipsel && 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[Rel.SectionID]; + uint8_t *Target = Section.Address + Rel.Offset; + uint32_t *TargetAddress = (uint32_t *)Target; + + // Extract the addend from the instruction. + uint32_t Addend = ((*TargetAddress) & 0x03ffffff) << 2; + + Value.Addend += Addend; + + // Look up for existing stub. + StubMap::const_iterator i = Stubs.find(Value); + if (i != Stubs.end()) { + resolveRelocation(Section, Rel.Offset, + (uint64_t)Section.Address + 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.StubOffset; + uint8_t *StubTargetAddr = createStubFunction(Section.Address + + Section.StubOffset); + + // Creating Hi and Lo relocations for the filled stub instructions. + RelocationEntry REHi(Rel.SectionID, + StubTargetAddr - Section.Address, + ELF::R_MIPS_HI16, Value.Addend); + RelocationEntry RELo(Rel.SectionID, + StubTargetAddr - Section.Address + 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); + } + + resolveRelocation(Section, Rel.Offset, + (uint64_t)Section.Address + Section.StubOffset, + RelType, 0); + Section.StubOffset += getMaxStubSize(); + } + } else if (Arch == Triple::ppc64) { + if (RelType == ELF::R_PPC64_REL24) { + // 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[Rel.SectionID]; + uint8_t *Target = Section.Address + Rel.Offset; + bool RangeOverflow = false; + if (SymType != SymbolRef::ST_Unknown) { + // A function call may points to the .opd entry, so the final symbol value + // in calculated based in the relocation values in .opd section. + findOPDEntrySection(Obj, ObjSectionToID, Value); + uint8_t *RelocTarget = Sections[Value.SectionID].Address + Value.Addend; + int32_t delta = static_cast<int32_t>(Target - RelocTarget); + // If it is within 24-bits branch range, just set the branch target + if (SignExtend32<24>(delta) == delta) { + RelocationEntry RE(Rel.SectionID, Rel.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 == true) { + // 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, Rel.Offset, + (uint64_t)Section.Address + 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.StubOffset; + uint8_t *StubTargetAddr = createStubFunction(Section.Address + + Section.StubOffset); + RelocationEntry RE(Rel.SectionID, StubTargetAddr - Section.Address, + ELF::R_PPC64_ADDR64, Value.Addend); + + // Generates the 64-bits address loads as exemplified in section + // 4.5.1 in PPC64 ELF ABI. + RelocationEntry REhst(Rel.SectionID, + StubTargetAddr - Section.Address + 2, + ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend); + RelocationEntry REhr(Rel.SectionID, + StubTargetAddr - Section.Address + 6, + ELF::R_PPC64_ADDR16_HIGHER, Value.Addend); + RelocationEntry REh(Rel.SectionID, + StubTargetAddr - Section.Address + 14, + ELF::R_PPC64_ADDR16_HI, Value.Addend); + RelocationEntry REl(Rel.SectionID, + StubTargetAddr - Section.Address + 18, + 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, Rel.Offset, + (uint64_t)Section.Address + Section.StubOffset, + RelType, 0); + if (SymType == SymbolRef::ST_Unknown) + // Restore the TOC for external calls + writeInt32BE(Target+4, 0xE8410028); // ld r2,40(r1) + Section.StubOffset += getMaxStubSize(); + } + } + } else { + RelocationEntry RE(Rel.SectionID, Rel.Offset, RelType, Value.Addend); + // Extra check to avoid relocation againt empty symbols (usually + // the R_PPC64_TOC). + if (Value.SymbolName && !TargetName.empty()) + addRelocationForSymbol(RE, Value.SymbolName); + else + addRelocationForSection(RE, Value.SectionID); + } } else { RelocationEntry RE(Rel.SectionID, Rel.Offset, RelType, Value.Addend); if (Value.SymbolName) @@ -432,8 +819,16 @@ void RuntimeDyldELF::processRelocationRef(const ObjRelocationInfo &Rel, } } -bool RuntimeDyldELF::isCompatibleFormat(const MemoryBuffer *InputBuffer) const { - StringRef Magic = InputBuffer->getBuffer().slice(0, ELF::EI_NIDENT); - return (memcmp(Magic.data(), ELF::ElfMagic, strlen(ELF::ElfMagic))) == 0; +unsigned RuntimeDyldELF::getCommonSymbolAlignment(const SymbolRef &Sym) { + // In ELF, the value of an SHN_COMMON symbol is its alignment requirement. + uint64_t Align; + Check(Sym.getValue(Align)); + return Align; +} + +bool RuntimeDyldELF::isCompatibleFormat(const ObjectBuffer *Buffer) const { + if (Buffer->getBufferSize() < strlen(ELF::ElfMagic)) + return false; + return (memcmp(Buffer->getBufferStart(), ELF::ElfMagic, strlen(ELF::ElfMagic))) == 0; } } // namespace llvm |