void Stub::applyFixup(Relocation& pSrcReloc, IRBuilder& pBuilder, BranchIsland& pIsland) { // build a name for stub symbol std::string sym_name("__"); sym_name.append(pSrcReloc.symInfo()->name()) .append("_") .append(name()) .append("@") .append(pIsland.name()); // create LDSymbol for the stub LDSymbol* symbol = pBuilder.AddSymbol<IRBuilder::Force, IRBuilder::Unresolve>( sym_name, ResolveInfo::Function, ResolveInfo::Define, ResolveInfo::Local, size(), initSymValue(), FragmentRef::Create(*this, initSymValue()), ResolveInfo::Default); setSymInfo(symbol->resolveInfo()); // add relocations of this stub (i.e., set the branch target of the stub) for (fixup_iterator it = fixup_begin(), ie = fixup_end(); it != ie; ++it) { Relocation* reloc = Relocation::Create((*it)->type(), *(FragmentRef::Create(*this, (*it)->offset())), (*it)->addend()); reloc->setSymInfo(pSrcReloc.symInfo()); pIsland.addRelocation(*reloc); } }
void X86RelocationFactory::applyRelocation(Relocation& pRelocation, const MCLDInfo& pLDInfo) { Relocation::Type type = pRelocation.type(); /// the prototype of applying function typedef Result (*ApplyFunctionType)(Relocation& pReloc, const MCLDInfo& pLDInfo, X86RelocationFactory& pParent); // the table entry of applying functions struct ApplyFunctionTriple { ApplyFunctionType func; unsigned int type; const char* name; }; // declare the table of applying functions static ApplyFunctionTriple apply_functions[] = { DECL_X86_APPLY_RELOC_FUNC_PTRS }; if (type >= sizeof (apply_functions) / sizeof (apply_functions[0]) ) { llvm::report_fatal_error(llvm::Twine("Unknown relocation type ") + llvm::Twine((int) type) + llvm::Twine(" to symbol `") + pRelocation.symInfo()->name() + llvm::Twine("'.")); return; } // apply the relocation Result result = apply_functions[type].func(pRelocation, pLDInfo, *this); // check result if (Overflow == result) { llvm::report_fatal_error(llvm::Twine("Applying relocation `") + llvm::Twine(apply_functions[type].name) + llvm::Twine("' causes overflow. on symbol: `") + llvm::Twine(pRelocation.symInfo()->name()) + llvm::Twine("'.")); return; } if (BadReloc == result) { llvm::report_fatal_error(llvm::Twine("Applying relocation `") + llvm::Twine(apply_functions[type].name) + llvm::Twine("' encounters unexpected opcode. " "on symbol: `") + llvm::Twine(pRelocation.symInfo()->name()) + llvm::Twine("'.")); return; } }
// R_HEX_PLT_B22_PCREL: PLT(S) + A - P Relocator::Result relocPLTB22PCREL(Relocation& pReloc, HexagonRelocator& pParent) { // PLT_S depends on if there is a PLT entry. Relocator::Address PLT_S; if ((pReloc.symInfo()->reserved() & HexagonRelocator::ReservePLT)) PLT_S = helper_get_PLT_address(*pReloc.symInfo(), pParent); else PLT_S = pReloc.symValue(); Relocator::Address P = pReloc.place(); uint32_t bitMask = FINDBITMASK(pReloc.target()); uint32_t result = (PLT_S + pReloc.addend() - P) >> 2; pReloc.target() = pReloc.target() | ApplyMask<uint32_t>(bitMask, result); return Relocator::OK; }
void HexagonRelocator::scanRelocation(Relocation& pReloc, IRBuilder& pLinker, Module& pModule, LDSection& pSection, Input& pInput) { if (LinkerConfig::Object == config().codeGenType()) return; // rsym - The relocation target symbol ResolveInfo* rsym = pReloc.symInfo(); assert(rsym != NULL && "ResolveInfo of relocation not set while scanRelocation"); if (config().isCodeStatic()) return; assert(pSection.getLink() != NULL); if ((pSection.getLink()->flag() & llvm::ELF::SHF_ALLOC) == 0) return; if (rsym->isLocal()) // rsym is local scanLocalReloc(pReloc, pLinker, pModule, pSection); else // rsym is external scanGlobalReloc(pReloc, pLinker, pModule, pSection); // check if we should issue undefined reference for the relocation target // symbol if (rsym->isUndef() && !rsym->isDyn() && !rsym->isWeak() && !rsym->isNull()) issueUndefRef(pReloc, pSection, pInput); }
uint32_t NyuziRelocator::getDebugStringOffset(Relocation& pReloc) const { if (pReloc.type() != llvm::ELF::R_NYUZI_ABS32) error(diag::unsupport_reloc_for_debug_string) << getName(pReloc.type()); return pReloc.symInfo()->outSymbol()->fragRef()->offset() + pReloc.target() + pReloc.addend(); }
/// addStub - add a stub into the island bool BranchIsland::addStub(const Stub* pPrototype, const Relocation& pReloc, Stub& pStub) { bool exist = false; Key key(pPrototype, pReloc.symInfo()->outSymbol(), pReloc.addend()); StubEntryType* entry = m_StubMap.insert(key, exist); if (!exist) { entry->setValue(&pStub); m_pRear = &pStub; SectionData* sd = m_Entry.getParent(); // insert alignment fragment // TODO: check if we can reduce this alignment fragment for some cases AlignFragment* align_frag = new AlignFragment(pStub.alignment(), 0x0, 1u, pStub.alignment() - 1); align_frag->setParent(sd); sd->getFragmentList().insert(end(), align_frag); align_frag->setOffset(align_frag->getPrevNode()->getOffset() + align_frag->getPrevNode()->size()); // insert stub fragment pStub.setParent(sd); sd->getFragmentList().insert(end(), &pStub); pStub.setOffset(pStub.getPrevNode()->getOffset() + pStub.getPrevNode()->size()); } return !exist; }
bool MipsGNULDBackend::relaxRelocation(IRBuilder& pBuilder, Relocation& pRel) { uint64_t sym_value = 0x0; LDSymbol* symbol = pRel.symInfo()->outSymbol(); if (symbol->hasFragRef()) { uint64_t value = symbol->fragRef()->getOutputOffset(); uint64_t addr = symbol->fragRef()->frag()->getParent()->getSection().addr(); sym_value = addr + value; } Stub* stub = getStubFactory()->create( pRel, sym_value, pBuilder, *getBRIslandFactory()); if (stub == NULL) return false; assert(stub->symInfo() != NULL); // increase the size of .symtab and .strtab LDSection& symtab = getOutputFormat()->getSymTab(); LDSection& strtab = getOutputFormat()->getStrTab(); symtab.setSize(symtab.size() + sizeof(llvm::ELF::Elf32_Sym)); strtab.setSize(strtab.size() + stub->symInfo()->nameSize() + 1); return true; }
Relocator::Result relocPCREL(Relocation& pReloc, HexagonRelocator& pParent) { ResolveInfo* rsym = pReloc.symInfo(); int64_t result; Relocator::Address S = pReloc.symValue(); Relocator::DWord A = pReloc.addend(); Relocator::DWord P = pReloc.place(); FragmentRef& target_fragref = pReloc.targetRef(); Fragment* target_frag = target_fragref.frag(); LDSection& target_sect = target_frag->getParent()->getSection(); result = (int64_t)(S + A - P); // for relocs inside non ALLOC, just apply if ((llvm::ELF::SHF_ALLOC & target_sect.flag()) == 0) { return applyRel(pReloc, result); } if (!rsym->isLocal()) { if (rsym->reserved() & HexagonRelocator::ReservePLT) { S = helper_get_PLT_address(*rsym, pParent); result = (int64_t)(S + A - P); applyRel(pReloc, result); return Relocator::OK; } } return applyRel(pReloc, result); }
void GarbageCollection::setUpReachedSections() { // traverse all the input relocations to setup the reached sections Module::obj_iterator input, inEnd = m_Module.obj_end(); for (input = m_Module.obj_begin(); input != inEnd; ++input) { LDContext::sect_iterator rs, rsEnd = (*input)->context()->relocSectEnd(); for (rs = (*input)->context()->relocSectBegin(); rs != rsEnd; ++rs) { // bypass the discarded relocation section // 1. its section kind is changed to Ignore. (The target section is a // discarded group section.) // 2. it has no reloc data. (All symbols in the input relocs are in the // discarded group sections) LDSection* reloc_sect = *rs; LDSection* apply_sect = reloc_sect->getLink(); if ((LDFileFormat::Ignore == reloc_sect->kind()) || (!reloc_sect->hasRelocData())) continue; // bypass the apply target sections which are not handled by gc (currently // we only handle the Regular and BSS sections) if (apply_sect->kind() != LDFileFormat::Regular && apply_sect->kind() != LDFileFormat::BSS) continue; bool add_first = false; SectionListTy* reached_sects = NULL; RelocData::iterator reloc_it, rEnd = reloc_sect->getRelocData()->end(); for (reloc_it = reloc_sect->getRelocData()->begin(); reloc_it != rEnd; ++reloc_it) { Relocation* reloc = llvm::cast<Relocation>(reloc_it); ResolveInfo* sym = reloc->symInfo(); // only the target symbols defined in the input fragments can make the // reference if (NULL == sym) continue; if (!sym->isDefine() || !sym->outSymbol()->hasFragRef()) continue; // only the target symbols defined in the concerned sections can make // the reference const LDSection* target_sect = &sym->outSymbol()->fragRef()->frag()->getParent()->getSection(); if (target_sect->kind() != LDFileFormat::Regular && target_sect->kind() != LDFileFormat::BSS) continue; // setup the reached list, if we first add the element to reached list // of this section, create an entry in ReachedSections map if (!add_first) { assert(NULL == reached_sects); reached_sects = &m_ReachedSections[apply_sect]; add_first = true; } reached_sects->insert(target_sect); } reached_sects = NULL; add_first = false; } } }
/// checkValidReloc - When we attempt to generate a dynamic relocation for /// ouput file, check if the relocation is supported by dynamic linker. void ARMGNULDBackend::checkValidReloc(Relocation& pReloc, const MCLDInfo& pLDInfo, const Output& pOutput) const { // If not building a PIC object, no relocation type is invalid if (!isPIC(pLDInfo, pOutput)) return; switch(pReloc.type()) { case llvm::ELF::R_ARM_RELATIVE: case llvm::ELF::R_ARM_COPY: case llvm::ELF::R_ARM_GLOB_DAT: case llvm::ELF::R_ARM_JUMP_SLOT: case llvm::ELF::R_ARM_ABS32: case llvm::ELF::R_ARM_ABS32_NOI: case llvm::ELF::R_ARM_PC24: case llvm::ELF::R_ARM_TLS_DTPMOD32: case llvm::ELF::R_ARM_TLS_DTPOFF32: case llvm::ELF::R_ARM_TLS_TPOFF32: break; default: llvm::report_fatal_error(llvm::Twine("Attempt to generate unsupported") + llvm::Twine(" relocation type ") + llvm::Twine((int)pReloc.type()) + llvm::Twine(" for symbol '") + llvm::Twine(pReloc.symInfo()->name()) + llvm::Twine("', recompile with -fPIC") ); break; } }
// R_386_32: S + A X86RelocationFactory::Result abs32(Relocation& pReloc, const MCLDInfo& pLDInfo, X86RelocationFactory& pParent) { ResolveInfo* rsym = pReloc.symInfo(); RelocationFactory::DWord A = pReloc.target() + pReloc.addend(); RelocationFactory::DWord S = pReloc.symValue(); if(rsym->isLocal() && (rsym->reserved() & X86GNULDBackend::ReserveRel)) { helper_DynRel(pReloc, llvm::ELF::R_386_RELATIVE, pParent); pReloc.target() = S + A; return X86RelocationFactory::OK; } else if(!rsym->isLocal()) { if(rsym->reserved() & X86GNULDBackend::ReservePLT) { S = helper_PLT(pReloc, pParent); pReloc.target() = S + A; } if(rsym->reserved() & X86GNULDBackend::ReserveRel) { if(helper_use_relative_reloc(*rsym, pLDInfo, pParent) ) { helper_DynRel(pReloc, llvm::ELF::R_386_RELATIVE, pParent); } else { helper_DynRel(pReloc, pReloc.type(), pParent); return X86RelocationFactory::OK; } } } // perform static relocation pReloc.target() = S + A; return X86RelocationFactory::OK; }
void ARMGNULDBackend::scanRelocation(Relocation& pReloc, const LDSymbol& pInputSym, MCLinker& pLinker, const MCLDInfo& pLDInfo, const Output& pOutput) { // rsym - The relocation target symbol ResolveInfo* rsym = pReloc.symInfo(); assert(NULL != rsym && "ResolveInfo of relocation not set while scanRelocation"); // Scan relocation type to determine if an GOT/PLT/Dynamic Relocation // entries should be created. // FIXME: Below judgements concern only .so is generated as output // FIXME: Below judgements concern nothing about TLS related relocation // A refernece to symbol _GLOBAL_OFFSET_TABLE_ implies that a .got section // is needed if(NULL == m_pGOT && NULL != m_pGOTSymbol) { if(rsym == m_pGOTSymbol->resolveInfo()) { createARMGOT(pLinker, pOutput); } } // rsym is local if(rsym->isLocal()) scanLocalReloc(pReloc, pInputSym, pLinker, pLDInfo, pOutput); // rsym is external else scanGlobalReloc(pReloc, pInputSym, pLinker, pLDInfo, pOutput); }
void ARMGNULDBackend::updateAddend(Relocation& pReloc, const LDSymbol& pInputSym, const Layout& pLayout) const { // Update value keep in addend if we meet a section symbol if(pReloc.symInfo()->type() == ResolveInfo::Section) { pReloc.setAddend(pLayout.getOutputOffset( *pInputSym.fragRef()) + pReloc.addend()); } }
void HexagonRelocator::partialScanRelocation(Relocation& pReloc, Module& pModule, const LDSection& pSection) { pReloc.updateAddend(); // if we meet a section symbol if (pReloc.symInfo()->type() == ResolveInfo::Section) { LDSymbol* input_sym = pReloc.symInfo()->outSymbol(); // 1. update the relocation target offset assert(input_sym->hasFragRef()); // 2. get the output LDSection which the symbol defined in const LDSection& out_sect = input_sym->fragRef()->frag()->getParent()->getSection(); ResolveInfo* sym_info = pModule.getSectionSymbolSet().get(out_sect)->resolveInfo(); // set relocation target symbol to the output section symbol's resolveInfo pReloc.setSymInfo(sym_info); } }
// R_386_32: S + A X86RelocationFactory::Result abs32(Relocation& pReloc, const MCLDInfo& pLDInfo, X86RelocationFactory& pParent) { ResolveInfo* rsym = pReloc.symInfo(); RelocationFactory::DWord A = pReloc.target() + pReloc.addend(); RelocationFactory::DWord S = pReloc.symValue(); bool has_dyn_rel = pParent.getTarget().symbolNeedsDynRel( *rsym, (rsym->reserved() & X86GNULDBackend::ReservePLT), pLDInfo, pLDInfo.output(), true); const LDSection* target_sect = pParent.getLayout().getOutputLDSection( *(pReloc.targetRef().frag())); assert(NULL != target_sect); // If the flag of target section is not ALLOC, we will not scan this relocation // but perform static relocation. (e.g., applying .debug section) if (0x0 == (llvm::ELF::SHF_ALLOC & target_sect->flag())) { pReloc.target() = S + A; return X86RelocationFactory::OK; } // A local symbol may need REL Type dynamic relocation if (rsym->isLocal() && has_dyn_rel) { helper_DynRel(pReloc, llvm::ELF::R_386_RELATIVE, pParent); pReloc.target() = S + A; return X86RelocationFactory::OK; } // An external symbol may need PLT and dynamic relocation if (!rsym->isLocal()) { if (rsym->reserved() & X86GNULDBackend::ReservePLT) { S = helper_PLT(pReloc, pParent); pReloc.target() = S + A; } // If we generate a dynamic relocation (except R_386_RELATIVE) // for a place, we should not perform static relocation on it // in order to keep the addend store in the place correct. if (has_dyn_rel) { if (helper_use_relative_reloc(*rsym, pLDInfo, pParent)) { helper_DynRel(pReloc, llvm::ELF::R_386_RELATIVE, pParent); } else { helper_DynRel(pReloc, pReloc.type(), pParent); return X86RelocationFactory::OK; } } } // perform static relocation pReloc.target() = S + A; return X86RelocationFactory::OK; }
void HexagonRelocator::scanLocalReloc(Relocation& pReloc, IRBuilder& pBuilder, Module& pModule, LDSection& pSection) { // rsym - The relocation target symbol ResolveInfo* rsym = pReloc.symInfo(); switch (pReloc.type()) { case llvm::ELF::R_HEX_LO16: case llvm::ELF::R_HEX_HI16: case llvm::ELF::R_HEX_16: case llvm::ELF::R_HEX_8: case llvm::ELF::R_HEX_32_6_X: case llvm::ELF::R_HEX_16_X: case llvm::ELF::R_HEX_12_X: case llvm::ELF::R_HEX_11_X: case llvm::ELF::R_HEX_10_X: case llvm::ELF::R_HEX_9_X: case llvm::ELF::R_HEX_8_X: case llvm::ELF::R_HEX_7_X: case llvm::ELF::R_HEX_6_X: assert(!(rsym->reserved() & ReserveRel) && "Cannot apply this relocation for read only section"); return; case llvm::ELF::R_HEX_32: // If buiding PIC object (shared library or PIC executable), // a dynamic relocations with RELATIVE type to this location is needed. // Reserve an entry in .rel.dyn if (config().isCodeIndep()) { Relocation& reloc = helper_DynRel_init(rsym, *pReloc.targetRef().frag(), pReloc.targetRef().offset(), llvm::ELF::R_HEX_RELATIVE, *this); // we need to set up the relocation addend at apply relocation, record // the // relocation getRelRelMap().record(pReloc, reloc); // set Rel bit rsym->setReserved(rsym->reserved() | ReserveRel); getTarget().checkAndSetHasTextRel(*pSection.getLink()); } return; default: return; } }
void Relocator::issueUndefRef(Relocation& pReloc, LDSection& pSection, Input& pInput) { FragmentRef::Offset undef_sym_pos = pReloc.targetRef().offset(); std::string sect_name(pSection.name()); sect_name = sect_name.substr(sect_name.find('.', /*pos=*/1)); // Drop .rel(a) prefix std::string reloc_sym(pReloc.symInfo()->name()); if (reloc_sym.substr(0, 2) == "_Z") reloc_sym = demangleSymbol(reloc_sym); std::stringstream ss; ss << "0x" << std::hex << undef_sym_pos; std::string undef_sym_pos_hex(ss.str()); if (sect_name.substr(0, 5) != ".text") { // Function name is only valid for text section fatal(diag::undefined_reference) << reloc_sym << pInput.path() << sect_name << undef_sym_pos_hex; return; } std::string caller_file_name; std::string caller_func_name; for (LDContext::sym_iterator i = pInput.context()->symTabBegin(), e = pInput.context()->symTabEnd(); i != e; ++i) { LDSymbol& sym = **i; if (sym.resolveInfo()->type() == ResolveInfo::File) caller_file_name = sym.resolveInfo()->name(); if (sym.resolveInfo()->type() == ResolveInfo::Function && sym.value() <= undef_sym_pos && sym.value() + sym.size() > undef_sym_pos) { caller_func_name = sym.name(); break; } } if (caller_func_name.substr(0, 2) == "_Z") caller_func_name = demangleSymbol(caller_func_name); fatal(diag::undefined_reference_text) << reloc_sym << pInput.path() << caller_file_name << caller_func_name; }
// R_386_PLT32: PLT(S) + A - P X86RelocationFactory::Result plt32(Relocation& pReloc, const MCLDInfo& pLDInfo, X86RelocationFactory& pParent) { // PLT_S depends on if there is a PLT entry. X86RelocationFactory::Address PLT_S; if((pReloc.symInfo()->reserved() & X86GNULDBackend::ReservePLT)) PLT_S = helper_PLT(pReloc, pParent); else PLT_S = pReloc.symValue(); RelocationFactory::DWord A = pReloc.target() + pReloc.addend(); X86RelocationFactory::Address P = pReloc.place(pParent.getLayout()); pReloc.target() = PLT_S + A - P; return X86RelocationFactory::OK; }
RelocationFactory::Result X86RelocationFactory::applyRelocation(Relocation& pRelocation, const MCLDInfo& pLDInfo) { Relocation::Type type = pRelocation.type(); if (type >= sizeof (ApplyFunctions) / sizeof (ApplyFunctions[0]) ) { fatal(diag::unknown_relocation) << (int)type << pRelocation.symInfo()->name(); return Unknown; } // apply the relocation return ApplyFunctions[type].func(pRelocation, pLDInfo, *this); }
// R_386_GOT32: GOT(S) + A - GOT_ORG X86RelocationFactory::Result got32(Relocation& pReloc, const MCLDInfo& pLDInfo, X86RelocationFactory& pParent) { if(!(pReloc.symInfo()->reserved() & (X86GNULDBackend::ReserveGOT |X86GNULDBackend::GOTRel))) { return X86RelocationFactory::BadReloc; } X86RelocationFactory::Address GOT_S = helper_GOT(pReloc, pLDInfo, pParent); RelocationFactory::DWord A = pReloc.target() + pReloc.addend(); X86RelocationFactory::Address GOT_ORG = helper_GOT_ORG(pParent); // Apply relocation. pReloc.target() = GOT_S + A - GOT_ORG; return X86RelocationFactory::OK; }
void DebugString::applyOffset(Relocation& pReloc, TargetLDBackend& pBackend) { // get the refered string ResolveInfo* info = pReloc.symInfo(); // the symbol should point to the first region fragment in the debug // string section, get the input .debut_str region llvm::StringRef d_str; if (info->outSymbol()->fragRef()->frag()->getKind() == Fragment::Region) { RegionFragment* frag = llvm::cast<RegionFragment>(info->outSymbol()->fragRef()->frag()); d_str = frag->getRegion(); } uint32_t offset = pBackend.getRelocator()->getDebugStringOffset(pReloc); const char* str = d_str.data() + offset; // apply the relocation pBackend.getRelocator()->applyDebugStringOffset(pReloc, m_StringTable.getOutputOffset(llvm::StringRef(str, string_length(str)))); }
void NyuziRelocator::scanRelocation(Relocation& pReloc, IRBuilder& pBuilder, Module& pModule, LDSection& pSection, Input& pInput) { ResolveInfo* rsym = pReloc.symInfo(); assert(NULL != rsym && "ResolveInfo of relocation not set while scanRelocation"); assert(NULL != pSection.getLink()); if (0 == (pSection.getLink()->flag() & llvm::ELF::SHF_ALLOC)) return; // check if we shoule issue undefined reference for the relocation target // symbol if (rsym->isUndef() && !rsym->isDyn() && !rsym->isWeak() && !rsym->isNull()) issueUndefRef(pReloc, pSection, pInput); }
bool MipsLA25Stub::isMyDuty(const Relocation& pReloc, uint64_t pSource, uint64_t pTargetSymValue) const { if (llvm::ELF::R_MIPS_26 != pReloc.type()) return false; const ResolveInfo* rsym = pReloc.symInfo(); if (!rsym->isDefine()) return false; if (rsym->isDyn() || rsym->isUndef()) return false; if (!m_Target.hasNonPICBranch(rsym)) return false; return true; }
// R_386_PC32: S + A - P X86RelocationFactory::Result rel32(Relocation& pReloc, const MCLDInfo& pLDInfo, X86RelocationFactory& pParent) { ResolveInfo* rsym = pReloc.symInfo(); RelocationFactory::DWord A = pReloc.target() + pReloc.addend(); RelocationFactory::DWord S = pReloc.symValue(); RelocationFactory::DWord P = pReloc.place(pParent.getLayout()); const LDSection* target_sect = pParent.getLayout().getOutputLDSection( *(pReloc.targetRef().frag())); assert(NULL != target_sect); // If the flag of target section is not ALLOC, we will not scan this relocation // but perform static relocation. (e.g., applying .debug section) if (0x0 == (llvm::ELF::SHF_ALLOC & target_sect->flag())) { pReloc.target() = S + A - P; return X86RelocationFactory::OK; } // An external symbol may need PLT and dynamic relocation if (!rsym->isLocal()) { if (rsym->reserved() & X86GNULDBackend::ReservePLT) { S = helper_PLT(pReloc, pParent); pReloc.target() = S + A - P; } if (pParent.getTarget().symbolNeedsDynRel( *rsym, (rsym->reserved() & X86GNULDBackend::ReservePLT), pLDInfo, pLDInfo.output(), false)) { if (helper_use_relative_reloc(*rsym, pLDInfo, pParent) ) { helper_DynRel(pReloc, llvm::ELF::R_386_RELATIVE, pParent); } else { helper_DynRel(pReloc, pReloc.type(), pParent); return X86RelocationFactory::OK; } } } // perform static relocation pReloc.target() = S + A - P; return X86RelocationFactory::OK; }
// Get an relocation entry in .rel.dyn and set its type to pType, // its FragmentRef to pReloc->targetFrag() and its ResolveInfo to pReloc->symInfo() static void helper_DynRel(Relocation& pReloc, X86RelocationFactory::Type pType, X86RelocationFactory& pParent) { // rsym - The relocation target symbol ResolveInfo* rsym = pReloc.symInfo(); X86GNULDBackend& ld_backend = pParent.getTarget(); bool exist; Relocation& rel_entry = *ld_backend.getRelDyn().getEntry(*rsym, false, exist); rel_entry.setType(pType); rel_entry.targetRef() = pReloc.targetRef(); if(pType == llvm::ELF::R_386_RELATIVE) rel_entry.setSymInfo(0); else rel_entry.setSymInfo(rsym); }
Relocator::Result relocAbs(Relocation& pReloc, HexagonRelocator& pParent) { ResolveInfo* rsym = pReloc.symInfo(); Relocator::Address S = pReloc.symValue(); Relocator::DWord A = pReloc.addend(); Relocation* rel_entry = pParent.getRelRelMap().lookUp(pReloc); bool has_dyn_rel = (rel_entry != NULL); // if the flag of target section is not ALLOC, we eprform only static // relocation. if (0 == (llvm::ELF::SHF_ALLOC & pReloc.targetRef().frag()->getParent()->getSection().flag())) { return applyAbs(pReloc); } // a local symbol with .rela type relocation if (rsym->isLocal() && has_dyn_rel) { rel_entry->setAddend(S + A); return Relocator::OK; } if (!rsym->isLocal()) { if (rsym->reserved() & HexagonRelocator::ReservePLT) { S = helper_get_PLT_address(*rsym, pParent); } if (has_dyn_rel) { if (llvm::ELF::R_HEX_32 == pReloc.type() && helper_use_relative_reloc(*rsym, pParent)) { rel_entry->setAddend(S + A); } else { rel_entry->setAddend(A); return Relocator::OK; } } } return applyAbs(pReloc); }
void ARMGNULDBackend::scanGlobalReloc(Relocation& pReloc, const LDSymbol& pInputSym, MCLinker& pLinker, const MCLDInfo& pLDInfo, const Output& pOutput) { // rsym - The relocation target symbol ResolveInfo* rsym = pReloc.symInfo(); switch(pReloc.type()) { // Set R_ARM_TARGET1 to R_ARM_ABS32 // Ref: GNU gold 1.11 arm.cc, line 9892 case llvm::ELF::R_ARM_TARGET1: pReloc.setType(llvm::ELF::R_ARM_ABS32); case llvm::ELF::R_ARM_ABS32: case llvm::ELF::R_ARM_ABS16: case llvm::ELF::R_ARM_ABS12: case llvm::ELF::R_ARM_THM_ABS5: case llvm::ELF::R_ARM_ABS8: case llvm::ELF::R_ARM_BASE_ABS: case llvm::ELF::R_ARM_MOVW_ABS_NC: case llvm::ELF::R_ARM_MOVT_ABS: case llvm::ELF::R_ARM_THM_MOVW_ABS_NC: case llvm::ELF::R_ARM_THM_MOVT_ABS: case llvm::ELF::R_ARM_ABS32_NOI: { // Absolute relocation type, symbol may needs PLT entry or // dynamic relocation entry if(isSymbolNeedsPLT(*rsym, pLDInfo, pOutput)) { // create plt for this symbol if it does not have one if(!(rsym->reserved() & 0x8u)){ // Create .got section if it doesn't exist if(NULL == m_pGOT) createARMGOT(pLinker, pOutput); // create .plt and .rel.plt if not exist if(NULL == m_pPLT) createARMPLTandRelPLT(pLinker, pOutput); // Symbol needs PLT entry, we need to reserve a PLT entry // and the corresponding GOT and dynamic relocation entry // in .got and .rel.plt. (GOT entry will be reserved simultaneously // when calling ARMPLT->reserveEntry()) m_pPLT->reserveEntry(); m_pRelPLT->reserveEntry(*m_pRelocFactory); // set PLT bit rsym->setReserved(rsym->reserved() | 0x8u); } } if(isSymbolNeedsDynRel(*rsym, pOutput, true)) { checkValidReloc(pReloc, pLDInfo, pOutput); // symbol needs dynamic relocation entry, reserve an entry in .rel.dyn // create .rel.dyn section if not exist if(NULL == m_pRelDyn) createARMRelDyn(pLinker, pOutput); m_pRelDyn->reserveEntry(*m_pRelocFactory); // set Rel bit rsym->setReserved(rsym->reserved() | 0x1u); } return; } case llvm::ELF::R_ARM_GOTOFF32: case llvm::ELF::R_ARM_GOTOFF12: { // A GOT section is needed if(NULL == m_pGOT) createARMGOT(pLinker, pOutput); return; } case llvm::ELF::R_ARM_BASE_PREL: // FIXME: Currently we only support R_ARM_BASE_PREL against // symbol _GLOBAL_OFFSET_TABLE_ if(rsym != m_pGOTSymbol->resolveInfo()) { llvm::report_fatal_error(llvm::Twine("Do not support relocation '") + llvm::Twine("R_ARM_BASE_PREL' against symbol '") + llvm::Twine(rsym->name()) + llvm::Twine(".'")); } case llvm::ELF::R_ARM_REL32: case llvm::ELF::R_ARM_LDR_PC_G0: case llvm::ELF::R_ARM_SBREL32: case llvm::ELF::R_ARM_THM_PC8: case llvm::ELF::R_ARM_MOVW_PREL_NC: case llvm::ELF::R_ARM_MOVT_PREL: case llvm::ELF::R_ARM_THM_MOVW_PREL_NC: case llvm::ELF::R_ARM_THM_MOVT_PREL: case llvm::ELF::R_ARM_THM_ALU_PREL_11_0: case llvm::ELF::R_ARM_THM_PC12: case llvm::ELF::R_ARM_REL32_NOI: case llvm::ELF::R_ARM_ALU_PC_G0_NC: case llvm::ELF::R_ARM_ALU_PC_G0: case llvm::ELF::R_ARM_ALU_PC_G1_NC: case llvm::ELF::R_ARM_ALU_PC_G1: case llvm::ELF::R_ARM_ALU_PC_G2: case llvm::ELF::R_ARM_LDR_PC_G1: case llvm::ELF::R_ARM_LDR_PC_G2: case llvm::ELF::R_ARM_LDRS_PC_G0: case llvm::ELF::R_ARM_LDRS_PC_G1: case llvm::ELF::R_ARM_LDRS_PC_G2: case llvm::ELF::R_ARM_LDC_PC_G0: case llvm::ELF::R_ARM_LDC_PC_G1: case llvm::ELF::R_ARM_LDC_PC_G2: case llvm::ELF::R_ARM_ALU_SB_G0_NC: case llvm::ELF::R_ARM_ALU_SB_G0: case llvm::ELF::R_ARM_ALU_SB_G1_NC: case llvm::ELF::R_ARM_ALU_SB_G1: case llvm::ELF::R_ARM_ALU_SB_G2: case llvm::ELF::R_ARM_LDR_SB_G0: case llvm::ELF::R_ARM_LDR_SB_G1: case llvm::ELF::R_ARM_LDR_SB_G2: case llvm::ELF::R_ARM_LDRS_SB_G0: case llvm::ELF::R_ARM_LDRS_SB_G1: case llvm::ELF::R_ARM_LDRS_SB_G2: case llvm::ELF::R_ARM_LDC_SB_G0: case llvm::ELF::R_ARM_LDC_SB_G1: case llvm::ELF::R_ARM_LDC_SB_G2: case llvm::ELF::R_ARM_MOVW_BREL_NC: case llvm::ELF::R_ARM_MOVT_BREL: case llvm::ELF::R_ARM_MOVW_BREL: case llvm::ELF::R_ARM_THM_MOVW_BREL_NC: case llvm::ELF::R_ARM_THM_MOVT_BREL: case llvm::ELF::R_ARM_THM_MOVW_BREL: { // Relative addressing relocation, may needs dynamic relocation if(isSymbolNeedsDynRel(*rsym, pOutput, false)) { checkValidReloc(pReloc, pLDInfo, pOutput); // create .rel.dyn section if not exist if(NULL == m_pRelDyn) createARMRelDyn(pLinker, pOutput); m_pRelDyn->reserveEntry(*m_pRelocFactory); // set Rel bit rsym->setReserved(rsym->reserved() | 0x1u); } return; } case llvm::ELF::R_ARM_THM_CALL: case llvm::ELF::R_ARM_PLT32: case llvm::ELF::R_ARM_CALL: case llvm::ELF::R_ARM_JUMP24: case llvm::ELF::R_ARM_THM_JUMP24: case llvm::ELF::R_ARM_SBREL31: case llvm::ELF::R_ARM_PREL31: case llvm::ELF::R_ARM_THM_JUMP19: case llvm::ELF::R_ARM_THM_JUMP6: case llvm::ELF::R_ARM_THM_JUMP11: case llvm::ELF::R_ARM_THM_JUMP8: { // These are branch relocation (except PREL31) // A PLT entry is needed when building shared library // return if we already create plt for this symbol if(rsym->reserved() & 0x8u) return; // if symbol is defined in the ouput file and it's not // preemptible, no need plt if(rsym->isDefine() && !rsym->isDyn() && !isSymbolPreemptible(*rsym, pLDInfo, pOutput)) { return; } // Create .got section if it doesn't exist if(NULL == m_pGOT) createARMGOT(pLinker, pOutput); // create .plt and .rel.plt if not exist if(NULL == m_pPLT) createARMPLTandRelPLT(pLinker, pOutput); // Symbol needs PLT entry, we need to reserve a PLT entry // and the corresponding GOT and dynamic relocation entry // in .got and .rel.plt. (GOT entry will be reserved simultaneously // when calling ARMPLT->reserveEntry()) m_pPLT->reserveEntry(); m_pRelPLT->reserveEntry(*m_pRelocFactory); // set PLT bit rsym->setReserved(rsym->reserved() | 0x8u); return; } // Set R_ARM_TARGET2 to R_ARM_GOT_PREL // Ref: GNU gold 1.11 arm.cc, line 9892 case llvm::ELF::R_ARM_TARGET2: pReloc.setType(llvm::ELF::R_ARM_GOT_PREL); case llvm::ELF::R_ARM_GOT_BREL: case llvm::ELF::R_ARM_GOT_ABS: case llvm::ELF::R_ARM_GOT_PREL: { // Symbol needs GOT entry, reserve entry in .got // return if we already create GOT for this symbol if(rsym->reserved() & 0x6u) return; if(NULL == m_pGOT) createARMGOT(pLinker, pOutput); m_pGOT->reserveEntry(); // If building shared object or the symbol is undefined, a dynamic // relocation is needed to relocate this GOT entry. Reserve an // entry in .rel.dyn if(Output::DynObj == pOutput.type() || rsym->isUndef() || rsym->isDyn()) { // create .rel.dyn section if not exist if(NULL == m_pRelDyn) createARMRelDyn(pLinker, pOutput); m_pRelDyn->reserveEntry(*m_pRelocFactory); // set GOTRel bit rsym->setReserved(rsym->reserved() | 0x4u); return; } // set GOT bit rsym->setReserved(rsym->reserved() | 0x2u); return; } case llvm::ELF::R_ARM_COPY: case llvm::ELF::R_ARM_GLOB_DAT: case llvm::ELF::R_ARM_JUMP_SLOT: case llvm::ELF::R_ARM_RELATIVE: { // These are relocation type for dynamic linker, shold not // appear in object file. llvm::report_fatal_error(llvm::Twine("Unexpected reloc ") + llvm::Twine((int)pReloc.type()) + llvm::Twine(" in object file")); break; } default: { break; } } // end switch }
bool AArch64GNULDBackend::doRelax(Module& pModule, IRBuilder& pBuilder, bool& pFinished) { assert(getStubFactory() != NULL && getBRIslandFactory() != NULL); // Number of new stubs added size_t num_new_stubs = 0; // String lengh to hold new stub symbols size_t stubs_strlen = 0; if (config().targets().fixCA53Erratum835769() || config().targets().fixCA53Erratum843419()) { scanErrata(pModule, pBuilder, num_new_stubs, stubs_strlen); } ELFFileFormat* file_format = getOutputFormat(); // check branch relocs and create the related stubs if needed Module::obj_iterator input, inEnd = pModule.obj_end(); for (input = pModule.obj_begin(); input != inEnd; ++input) { LDContext::sect_iterator rs, rsEnd = (*input)->context()->relocSectEnd(); for (rs = (*input)->context()->relocSectBegin(); rs != rsEnd; ++rs) { if (LDFileFormat::Ignore == (*rs)->kind() || !(*rs)->hasRelocData()) continue; RelocData::iterator reloc, rEnd = (*rs)->getRelocData()->end(); for (reloc = (*rs)->getRelocData()->begin(); reloc != rEnd; ++reloc) { Relocation* relocation = llvm::cast<Relocation>(reloc); switch (relocation->type()) { case llvm::ELF::R_AARCH64_CALL26: case llvm::ELF::R_AARCH64_JUMP26: { // calculate the possible symbol value uint64_t sym_value = 0x0; LDSymbol* symbol = relocation->symInfo()->outSymbol(); if (symbol->hasFragRef()) { uint64_t value = symbol->fragRef()->getOutputOffset(); uint64_t addr = symbol->fragRef()->frag()->getParent()->getSection().addr(); sym_value = addr + value; } if ((relocation->symInfo()->reserved() & AArch64Relocator::ReservePLT) != 0x0) { // FIXME: we need to find out the address of the specific plt // entry assert(file_format->hasPLT()); sym_value = file_format->getPLT().addr(); } Stub* stub = getStubFactory()->create(*relocation, // relocation sym_value, // symbol value pBuilder, *getBRIslandFactory()); if (stub != NULL) { // a stub symbol should be local assert(stub->symInfo() != NULL && stub->symInfo()->isLocal()); // reset the branch target of the reloc to this stub instead relocation->setSymInfo(stub->symInfo()); ++num_new_stubs; stubs_strlen += stub->symInfo()->nameSize() + 1; } break; } default: { break; } } // end of switch } // for all relocations } // for all relocation section } // for all inputs // Find the first fragment w/ invalid offset due to stub insertion. std::vector<Fragment*> invalid_frags; pFinished = true; for (BranchIslandFactory::iterator island = getBRIslandFactory()->begin(), island_end = getBRIslandFactory()->end(); island != island_end; ++island) { if ((*island).size() > stubGroupSize()) { error(diag::err_no_space_to_place_stubs) << stubGroupSize(); return false; } if ((*island).numOfStubs() == 0) { continue; } Fragment* exit = &*(*island).end(); if (exit == (*island).begin()->getParent()->end()) { continue; } if (((*island).offset() + (*island).size()) > exit->getOffset()) { if (invalid_frags.empty() || (invalid_frags.back()->getParent() != (*island).getParent())) { invalid_frags.push_back(exit); pFinished = false; } continue; } } // Reset the offset of invalid fragments. for (auto it = invalid_frags.begin(), ie = invalid_frags.end(); it != ie; ++it) { Fragment* invalid = *it; while (invalid != NULL) { invalid->setOffset(invalid->getPrevNode()->getOffset() + invalid->getPrevNode()->size()); invalid = invalid->getNextNode(); } } // Fix up the size of .symtab, .strtab, and TEXT sections if (num_new_stubs == 0) { return false; } else { switch (config().options().getStripSymbolMode()) { case GeneralOptions::StripSymbolMode::StripAllSymbols: case GeneralOptions::StripSymbolMode::StripLocals: break; default: { LDSection& symtab = file_format->getSymTab(); LDSection& strtab = file_format->getStrTab(); symtab.setSize(symtab.size() + sizeof(llvm::ELF::Elf64_Sym) * num_new_stubs); symtab.setInfo(symtab.getInfo() + num_new_stubs); strtab.setSize(strtab.size() + stubs_strlen); } } // switch (config().options().getStripSymbolMode()) SectionData* prev = NULL; for (BranchIslandFactory::iterator island = getBRIslandFactory()->begin(), island_end = getBRIslandFactory()->end(); island != island_end; ++island) { SectionData* sd = (*island).begin()->getParent(); if ((*island).numOfStubs() != 0) { if (sd != prev) { sd->getSection().setSize(sd->back().getOffset() + sd->back().size()); } } prev = sd; } return true; } // if (num_new_stubs == 0) }
void ARMGNULDBackend::scanLocalReloc(Relocation& pReloc, const LDSymbol& pInputSym, MCLinker& pLinker, const MCLDInfo& pLDInfo, const Output& pOutput) { // rsym - The relocation target symbol ResolveInfo* rsym = pReloc.symInfo(); updateAddend(pReloc, pInputSym, pLinker.getLayout()); switch(pReloc.type()){ // Set R_ARM_TARGET1 to R_ARM_ABS32 // Ref: GNU gold 1.11 arm.cc, line 9892 case llvm::ELF::R_ARM_TARGET1: pReloc.setType(llvm::ELF::R_ARM_ABS32); case llvm::ELF::R_ARM_ABS32: case llvm::ELF::R_ARM_ABS32_NOI: { // If buiding PIC object (shared library or PIC executable), // a dynamic relocations with RELATIVE type to this location is needed. // Reserve an entry in .rel.dyn if(isPIC(pLDInfo, pOutput)) { // create .rel.dyn section if not exist if(NULL == m_pRelDyn) createARMRelDyn(pLinker, pOutput); m_pRelDyn->reserveEntry(*m_pRelocFactory); // set Rel bit rsym->setReserved(rsym->reserved() | 0x1u); } return; } case llvm::ELF::R_ARM_ABS16: case llvm::ELF::R_ARM_ABS12: case llvm::ELF::R_ARM_THM_ABS5: case llvm::ELF::R_ARM_ABS8: case llvm::ELF::R_ARM_BASE_ABS: case llvm::ELF::R_ARM_MOVW_ABS_NC: case llvm::ELF::R_ARM_MOVT_ABS: case llvm::ELF::R_ARM_THM_MOVW_ABS_NC: case llvm::ELF::R_ARM_THM_MOVT_ABS: { // Update value keep in relocation place if we meet a section symbol if(rsym->type() == ResolveInfo::Section) { pReloc.target() = pLinker.getLayout().getOutputOffset( *pInputSym.fragRef()) + pReloc.target(); } // If building PIC object (shared library or PIC executable), // a dynamic relocation for this location is needed. // Reserve an entry in .rel.dyn if(isPIC(pLDInfo, pOutput)) { checkValidReloc(pReloc, pLDInfo, pOutput); // create .rel.dyn section if not exist if(NULL == m_pRelDyn) createARMRelDyn(pLinker, pOutput); m_pRelDyn->reserveEntry(*m_pRelocFactory); // set Rel bit rsym->setReserved(rsym->reserved() | 0x1u); } return; } case llvm::ELF::R_ARM_GOTOFF32: case llvm::ELF::R_ARM_GOTOFF12: { // A GOT section is needed if(NULL == m_pGOT) createARMGOT(pLinker, pOutput); return; } // Set R_ARM_TARGET2 to R_ARM_GOT_PREL // Ref: GNU gold 1.11 arm.cc, line 9892 case llvm::ELF::R_ARM_TARGET2: pReloc.setType(llvm::ELF::R_ARM_GOT_PREL); case llvm::ELF::R_ARM_GOT_BREL: case llvm::ELF::R_ARM_GOT_PREL: { // A GOT entry is needed for these relocation type. // return if we already create GOT for this symbol if(rsym->reserved() & 0x6u) return; if(NULL == m_pGOT) createARMGOT(pLinker, pOutput); m_pGOT->reserveEntry(); // If building PIC object, a dynamic relocation with // type RELATIVE is needed to relocate this GOT entry. // Reserve an entry in .rel.dyn if(isPIC(pLDInfo, pOutput)) { // create .rel.dyn section if not exist if(NULL == m_pRelDyn) createARMRelDyn(pLinker, pOutput); m_pRelDyn->reserveEntry(*m_pRelocFactory); // set GOTRel bit rsym->setReserved(rsym->reserved() | 0x4u); return; } // set GOT bit rsym->setReserved(rsym->reserved() | 0x2u); return; } case llvm::ELF::R_ARM_BASE_PREL: { // FIXME: Currently we only support R_ARM_BASE_PREL against // symbol _GLOBAL_OFFSET_TABLE_ if(rsym != m_pGOTSymbol->resolveInfo()) { llvm::report_fatal_error(llvm::Twine("Do not support relocation '") + llvm::Twine("R_ARM_BASE_PREL' against symbol '") + llvm::Twine(rsym->name()) + llvm::Twine(".'")); } return; } case llvm::ELF::R_ARM_COPY: case llvm::ELF::R_ARM_GLOB_DAT: case llvm::ELF::R_ARM_JUMP_SLOT: case llvm::ELF::R_ARM_RELATIVE: { // These are relocation type for dynamic linker, shold not // appear in object file. llvm::report_fatal_error(llvm::Twine("unexpected reloc ") + llvm::Twine((int)pReloc.type()) + llvm::Twine(" in object file")); break; } default: { break; } } // end switch }
bool HexagonLDBackend::doRelax(Module& pModule, IRBuilder& pBuilder, bool& pFinished) { assert(NULL != getStubFactory() && NULL != getBRIslandFactory()); bool isRelaxed = false; ELFFileFormat* file_format = getOutputFormat(); // check branch relocs and create the related stubs if needed Module::obj_iterator input, inEnd = pModule.obj_end(); for (input = pModule.obj_begin(); input != inEnd; ++input) { LDContext::sect_iterator rs, rsEnd = (*input)->context()->relocSectEnd(); for (rs = (*input)->context()->relocSectBegin(); rs != rsEnd; ++rs) { if (LDFileFormat::Ignore == (*rs)->kind() || !(*rs)->hasRelocData()) continue; RelocData::iterator reloc, rEnd = (*rs)->getRelocData()->end(); for (reloc = (*rs)->getRelocData()->begin(); reloc != rEnd; ++reloc) { switch (reloc->type()) { case llvm::ELF::R_HEX_B22_PCREL: case llvm::ELF::R_HEX_B15_PCREL: case llvm::ELF::R_HEX_B7_PCREL: case llvm::ELF::R_HEX_B13_PCREL: case llvm::ELF::R_HEX_B9_PCREL: { Relocation* relocation = llvm::cast<Relocation>(reloc); uint64_t sym_value = 0x0; LDSymbol* symbol = relocation->symInfo()->outSymbol(); if (symbol->hasFragRef()) { uint64_t value = symbol->fragRef()->getOutputOffset(); uint64_t addr = symbol->fragRef()->frag()->getParent()->getSection().addr(); sym_value = addr + value; } Stub* stub = getStubFactory()->create(*relocation, // relocation sym_value, //symbol value pBuilder, *getBRIslandFactory()); if (NULL != stub) { assert(NULL != stub->symInfo()); // increase the size of .symtab and .strtab LDSection& symtab = file_format->getSymTab(); LDSection& strtab = file_format->getStrTab(); symtab.setSize(symtab.size() + sizeof(llvm::ELF::Elf32_Sym)); strtab.setSize(strtab.size() + stub->symInfo()->nameSize() + 1); isRelaxed = true; } } break; default: break; } } } } // find the first fragment w/ invalid offset due to stub insertion Fragment* invalid = NULL; pFinished = true; for (BranchIslandFactory::iterator island = getBRIslandFactory()->begin(), island_end = getBRIslandFactory()->end(); island != island_end; ++island) { if ((*island).end() == file_format->getText().getSectionData()->end()) break; Fragment* exit = (*island).end(); if (((*island).offset() + (*island).size()) > exit->getOffset()) { invalid = exit; pFinished = false; break; } } // reset the offset of invalid fragments while (NULL != invalid) { invalid->setOffset(invalid->getPrevNode()->getOffset() + invalid->getPrevNode()->size()); invalid = invalid->getNextNode(); } // reset the size of .text if (isRelaxed) { file_format->getText().setSize( file_format->getText().getSectionData()->back().getOffset() + file_format->getText().getSectionData()->back().size()); } return isRelaxed; }