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Diffstat (limited to 'contrib/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp')
-rw-r--r-- | contrib/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp | 1086 |
1 files changed, 1086 insertions, 0 deletions
diff --git a/contrib/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp b/contrib/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp new file mode 100644 index 0000000..d4d84d3 --- /dev/null +++ b/contrib/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp @@ -0,0 +1,1086 @@ +//===-- 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. +// +//===----------------------------------------------------------------------===// + +#define DEBUG_TYPE "dyld" +#include "RuntimeDyldELF.h" +#include "JITRegistrar.h" +#include "ObjectImageCommon.h" +#include "llvm/ADT/IntervalMap.h" +#include "llvm/ADT/OwningPtr.h" +#include "llvm/ADT/STLExtras.h" +#include "llvm/ADT/StringRef.h" +#include "llvm/ADT/Triple.h" +#include "llvm/ExecutionEngine/ObjectBuffer.h" +#include "llvm/ExecutionEngine/ObjectImage.h" +#include "llvm/Object/ELF.h" +#include "llvm/Object/ObjectFile.h" +#include "llvm/Support/ELF.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<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(MemoryBuffer *Wrapper, error_code &ec); + + void updateSectionAddress(const SectionRef &Sec, uint64_t Addr); + void updateSymbolAddress(const SymbolRef &Sym, 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(); + } +}; + +template<class ELFT> +class ELFObjectImage : public ObjectImageCommon { + protected: + DyldELFObject<ELFT> *DyldObj; + bool Registered; + + public: + ELFObjectImage(ObjectBuffer *Input, + DyldELFObject<ELFT> *Obj) + : ObjectImageCommon(Input, Obj), + DyldObj(Obj), + Registered(false) {} + + virtual ~ELFObjectImage() { + if (Registered) + deregisterWithDebugger(); + } + + // Subclasses can override these methods to update the image with loaded + // addresses for sections and common symbols + virtual void updateSectionAddress(const SectionRef &Sec, uint64_t Addr) + { + DyldObj->updateSectionAddress(Sec, Addr); + } + + virtual void updateSymbolAddress(const SymbolRef &Sym, uint64_t Addr) + { + DyldObj->updateSymbolAddress(Sym, Addr); + } + + virtual void registerWithDebugger() + { + JITRegistrar::getGDBRegistrar().registerObject(*Buffer); + Registered = true; + } + virtual void deregisterWithDebugger() + { + 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<class ELFT> +DyldELFObject<ELFT>::DyldELFObject(MemoryBuffer *Wrapper, 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); +} + +} // namespace + +namespace llvm { + +StringRef RuntimeDyldELF::getEHFrameSection() { + for (int i = 0, e = Sections.size(); i != e; ++i) { + if (Sections[i].Name == ".eh_frame") + return StringRef((const char*)Sections[i].Address, Sections[i].Size); + } + return StringRef(); +} + +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<ELFType<support::little, 4, false> > *Obj = + new DyldELFObject<ELFType<support::little, 4, false> >( + Buffer->getMemBuffer(), ec); + return new ELFObjectImage<ELFType<support::little, 4, false> >(Buffer, Obj); + } + else if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2MSB) { + DyldELFObject<ELFType<support::big, 4, false> > *Obj = + new DyldELFObject<ELFType<support::big, 4, false> >( + Buffer->getMemBuffer(), ec); + return new ELFObjectImage<ELFType<support::big, 4, false> >(Buffer, Obj); + } + else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2MSB) { + DyldELFObject<ELFType<support::big, 8, true> > *Obj = + new DyldELFObject<ELFType<support::big, 8, true> >( + Buffer->getMemBuffer(), ec); + return new ELFObjectImage<ELFType<support::big, 8, true> >(Buffer, Obj); + } + else if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2LSB) { + DyldELFObject<ELFType<support::little, 8, true> > *Obj = + new DyldELFObject<ELFType<support::little, 8, true> >( + Buffer->getMemBuffer(), ec); + return new ELFObjectImage<ELFType<support::little, 8, true> >(Buffer, Obj); + } + else + llvm_unreachable("Unexpected ELF format"); +} + +RuntimeDyldELF::~RuntimeDyldELF() { +} + +void RuntimeDyldELF::resolveX86_64Relocation(const SectionEntry &Section, + uint64_t Offset, + uint64_t Value, + uint32_t Type, + int64_t Addend) { + switch (Type) { + default: + llvm_unreachable("Relocation type not implemented yet!"); + break; + case ELF::R_X86_64_64: { + 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: + 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); + 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: { + // 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); + *Target = TruncOffset; + 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: { + // 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: { + // 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; + *Target = 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.Address + Offset); + uint64_t FinalAddress = Section.LoadAddress + Offset; + + DEBUG(dbgs() << "resolveAArch64Relocation, LocalAddress: 0x" + << format("%llx", Section.Address + 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.Address + Offset); + *TargetPtr = Value + Addend; + break; + } + case ELF::R_AARCH64_PREL32: { // test-shift.ll (.eh_frame) + 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(-(1LL << 27) <= static_cast<int64_t>(BranchImm) && + static_cast<int64_t>(BranchImm) < (1LL << 27)); + // 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; + // Immediate goes in bits 20:5 of MOVZ/MOVK instruction + *TargetPtr |= Result >> (48 - 5); + // Shift is "lsl #48", in bits 22:21 + *TargetPtr |= 3 << 21; + break; + } + case ELF::R_AARCH64_MOVW_UABS_G2_NC: { + uint64_t Result = Value + Addend; + // Immediate goes in bits 20:5 of MOVZ/MOVK instruction + *TargetPtr |= ((Result & 0xffff00000000ULL) >> (32 - 5)); + // Shift is "lsl #32", in bits 22:21 + *TargetPtr |= 2 << 21; + break; + } + case ELF::R_AARCH64_MOVW_UABS_G1_NC: { + uint64_t Result = Value + Addend; + // Immediate goes in bits 20:5 of MOVZ/MOVK instruction + *TargetPtr |= ((Result & 0xffff0000U) >> (16 - 5)); + // Shift is "lsl #16", in bits 22:21 + *TargetPtr |= 1 << 21; + break; + } + case ELF::R_AARCH64_MOVW_UABS_G0_NC: { + uint64_t Result = Value + Addend; + // Immediate goes in bits 20:5 of MOVZ/MOVK instruction + *TargetPtr |= ((Result & 0xffffU) << 5); + // Shift is "lsl #0", in bits 22:21. No action needed. + 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 = (uint32_t*)(Section.Address + Offset); + uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF); + Value += Addend; + + DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: " + << Section.Address + 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!"); + + // Write a 32bit value to relocation address, taking into account the + // implicit addend encoded in the target. + case ELF::R_ARM_TARGET1 : + case ELF::R_ARM_ABS32 : + *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; + break; + + // 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; + 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; + *TargetPtr &= 0xFF000000; + *TargetPtr |= RelValue; + break; + } +} + +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_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.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_REL32 : { + uint64_t FinalAddress = (Section.LoadAddress + 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.LoadAddress + Offset); + uint64_t Delta = Value - FinalAddress + Addend; + writeInt64BE(LocalAddress, Delta); + } 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::resolveSystemZRelocation(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_390_PC16DBL: + case ELF::R_390_PLT16DBL: { + int64_t Delta = (Value + Addend) - (Section.LoadAddress + 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.LoadAddress + 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.LoadAddress + Offset); + assert(int32_t(Delta) == Delta && "R_390_PC32 overflow"); + writeInt32BE(LocalAddress, Delta); + break; + } + case ELF::R_390_64: + writeInt64BE(LocalAddress, Value + Addend); + break; + } +} + +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); +} + +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(Section, Offset, Value, Type, Addend); + break; + case Triple::x86: + resolveX86Relocation(Section, Offset, + (uint32_t)(Value & 0xffffffffL), Type, + (uint32_t)(Addend & 0xffffffffL)); + break; + case Triple::aarch64: + resolveAArch64Relocation(Section, Offset, Value, Type, Addend); + break; + case Triple::arm: // Fall through. + case Triple::thumb: + 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; + case Triple::systemz: + resolveSystemZRelocation(Section, Offset, Value, Type, Addend); + break; + default: llvm_unreachable("Unsupported CPU type!"); + } +} + +void RuntimeDyldELF::processRelocationRef(unsigned SectionID, + RelocationRef RelI, + ObjectImage &Obj, + ObjSectionToIDMap &ObjSectionToID, + const SymbolTableMap &Symbols, + StubMap &Stubs) { + uint64_t RelType; + Check(RelI.getType(RelType)); + int64_t Addend; + Check(RelI.getAdditionalInfo(Addend)); + SymbolRef Symbol; + Check(RelI.getSymbol(Symbol)); + + // Obtain the symbol name which is referenced in the relocation + StringRef TargetName; + Symbol.getName(TargetName); + DEBUG(dbgs() << "\t\tRelType: " << RelType + << " Addend: " << Addend + << " TargetName: " << TargetName + << "\n"); + 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 + Addend; + } else { + // Search for the symbol in the global symbol table + SymbolTableMap::const_iterator gsi = + GlobalSymbolTable.find(TargetName.data()); + if (gsi != GlobalSymbolTable.end()) { + Value.SectionID = gsi->second.first; + Value.Addend = gsi->second.second + 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. + section_iterator si(Obj.end_sections()); + Symbol.getSection(si); + if (si == Obj.end_sections()) + llvm_unreachable("Symbol section not found, bad object file format!"); + DEBUG(dbgs() << "\t\tThis is section symbol\n"); + // 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; + } + case SymbolRef::ST_Unknown: { + Value.SymbolName = TargetName.data(); + Value.Addend = Addend; + break; + } + default: + llvm_unreachable("Unresolved symbol type!"); + break; + } + } + } + uint64_t Offset; + Check(RelI.getOffset(Offset)); + + DEBUG(dbgs() << "\t\tSectionID: " << SectionID + << " Offset: " << Offset + << "\n"); + if (Arch == Triple::aarch64 && + (RelType == ELF::R_AARCH64_CALL26 || + RelType == ELF::R_AARCH64_JUMP26)) { + // This is an AArch64 branch relocation, need to use a stub function. + DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation."); + SectionEntry &Section = Sections[SectionID]; + + // Look for an existing stub. + StubMap::const_iterator i = Stubs.find(Value); + if (i != Stubs.end()) { + resolveRelocation(Section, 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 REmovz_g3(SectionID, + StubTargetAddr - Section.Address, + ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend); + RelocationEntry REmovk_g2(SectionID, + StubTargetAddr - Section.Address + 4, + ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend); + RelocationEntry REmovk_g1(SectionID, + StubTargetAddr - Section.Address + 8, + ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend); + RelocationEntry REmovk_g0(SectionID, + StubTargetAddr - Section.Address + 12, + ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend); + + if (Value.SymbolName) { + addRelocationForSymbol(REmovz_g3, Value.SymbolName); + addRelocationForSymbol(REmovk_g2, Value.SymbolName); + addRelocationForSymbol(REmovk_g1, Value.SymbolName); + addRelocationForSymbol(REmovk_g0, Value.SymbolName); + } else { + addRelocationForSection(REmovz_g3, Value.SectionID); + addRelocationForSection(REmovk_g2, Value.SectionID); + addRelocationForSection(REmovk_g1, Value.SectionID); + addRelocationForSection(REmovk_g0, Value.SectionID); + } + resolveRelocation(Section, Offset, + (uint64_t)Section.Address + Section.StubOffset, + RelType, 0); + Section.StubOffset += getMaxStubSize(); + } + } else if (Arch == Triple::arm && + (RelType == ELF::R_ARM_PC24 || + RelType == ELF::R_ARM_CALL || + RelType == ELF::R_ARM_JUMP24)) { + // This is an ARM branch relocation, need to use a stub function. + DEBUG(dbgs() << "\t\tThis is an ARM branch relocation."); + SectionEntry &Section = Sections[SectionID]; + + // Look for an existing stub. + StubMap::const_iterator i = Stubs.find(Value); + if (i != Stubs.end()) { + resolveRelocation(Section, 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(SectionID, StubTargetAddr - Section.Address, + ELF::R_ARM_ABS32, Value.Addend); + if (Value.SymbolName) + addRelocationForSymbol(RE, Value.SymbolName); + else + addRelocationForSection(RE, Value.SectionID); + + resolveRelocation(Section, Offset, + (uint64_t)Section.Address + Section.StubOffset, + RelType, 0); + Section.StubOffset += getMaxStubSize(); + } + } else if ((Arch == Triple::mipsel || Arch == Triple::mips) && + 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[SectionID]; + uint8_t *Target = Section.Address + 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, 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(SectionID, + StubTargetAddr - Section.Address, + ELF::R_MIPS_HI16, Value.Addend); + RelocationEntry RELo(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, 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[SectionID]; + uint8_t *Target = Section.Address + 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(SectionID, 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, 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(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(SectionID, + StubTargetAddr - Section.Address + 2, + ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend); + RelocationEntry REhr(SectionID, + StubTargetAddr - Section.Address + 6, + ELF::R_PPC64_ADDR16_HIGHER, Value.Addend); + RelocationEntry REh(SectionID, + StubTargetAddr - Section.Address + 14, + ELF::R_PPC64_ADDR16_HI, Value.Addend); + RelocationEntry 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, 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(SectionID, 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 if (Arch == Triple::systemz && + (RelType == ELF::R_390_PLT32DBL || + RelType == ELF::R_390_GOTENT)) { + // Create function stubs for both PLT and GOT references, regardless of + // whether the GOT reference is to data or code. The stub contains the + // full address of the symbol, as needed by GOT references, and the + // executable part only adds an overhead of 8 bytes. + // + // We could try to conserve space by allocating the code and data + // parts of the stub separately. However, as things stand, we allocate + // a stub for every relocation, so using a GOT in JIT code should be + // no less space efficient than using an explicit constant pool. + DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation."); + SectionEntry &Section = Sections[SectionID]; + + // Look for an existing stub. + StubMap::const_iterator i = Stubs.find(Value); + uintptr_t StubAddress; + if (i != Stubs.end()) { + StubAddress = uintptr_t(Section.Address) + i->second; + DEBUG(dbgs() << " Stub function found\n"); + } else { + // Create a new stub function. + DEBUG(dbgs() << " Create a new stub function\n"); + + uintptr_t BaseAddress = uintptr_t(Section.Address); + uintptr_t StubAlignment = getStubAlignment(); + StubAddress = (BaseAddress + Section.StubOffset + + StubAlignment - 1) & -StubAlignment; + unsigned StubOffset = StubAddress - BaseAddress; + + Stubs[Value] = StubOffset; + createStubFunction((uint8_t *)StubAddress); + RelocationEntry RE(SectionID, StubOffset + 8, + ELF::R_390_64, Value.Addend - Addend); + if (Value.SymbolName) + addRelocationForSymbol(RE, Value.SymbolName); + else + addRelocationForSection(RE, Value.SectionID); + Section.StubOffset = StubOffset + getMaxStubSize(); + } + + if (RelType == ELF::R_390_GOTENT) + resolveRelocation(Section, Offset, StubAddress + 8, + ELF::R_390_PC32DBL, Addend); + else + resolveRelocation(Section, Offset, StubAddress, RelType, Addend); + } else { + RelocationEntry RE(SectionID, Offset, RelType, Value.Addend); + if (Value.SymbolName) + addRelocationForSymbol(RE, Value.SymbolName); + else + addRelocationForSection(RE, Value.SectionID); + } +} + +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 |