1 //===-- RuntimeDyldELF.h - Run-time dynamic linker for MC-JIT ---*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // ELF support for MC-JIT runtime dynamic linker. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_RUNTIMEDYLDELF_H 15 #define LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_RUNTIMEDYLDELF_H 16 17 #include "RuntimeDyldImpl.h" 18 #include "llvm/ADT/DenseMap.h" 19 20 using namespace llvm; 21 22 namespace llvm { 23 namespace object { 24 class ELFObjectFileBase; 25 } 26 27 class RuntimeDyldELF : public RuntimeDyldImpl { 28 29 void resolveRelocation(const SectionEntry &Section, uint64_t Offset, 30 uint64_t Value, uint32_t Type, int64_t Addend, 31 uint64_t SymOffset = 0, SID SectionID = 0); 32 33 void resolveX86_64Relocation(const SectionEntry &Section, uint64_t Offset, 34 uint64_t Value, uint32_t Type, int64_t Addend, 35 uint64_t SymOffset); 36 37 void resolveX86Relocation(const SectionEntry &Section, uint64_t Offset, 38 uint32_t Value, uint32_t Type, int32_t Addend); 39 40 void resolveAArch64Relocation(const SectionEntry &Section, uint64_t Offset, 41 uint64_t Value, uint32_t Type, int64_t Addend); 42 43 void resolveARMRelocation(const SectionEntry &Section, uint64_t Offset, 44 uint32_t Value, uint32_t Type, int32_t Addend); 45 46 void resolveMIPSRelocation(const SectionEntry &Section, uint64_t Offset, 47 uint32_t Value, uint32_t Type, int32_t Addend); 48 49 void resolvePPC32Relocation(const SectionEntry &Section, uint64_t Offset, 50 uint64_t Value, uint32_t Type, int64_t Addend); 51 52 void resolvePPC64Relocation(const SectionEntry &Section, uint64_t Offset, 53 uint64_t Value, uint32_t Type, int64_t Addend); 54 55 void resolveSystemZRelocation(const SectionEntry &Section, uint64_t Offset, 56 uint64_t Value, uint32_t Type, int64_t Addend); 57 58 void resolveMIPS64Relocation(const SectionEntry &Section, uint64_t Offset, 59 uint64_t Value, uint32_t Type, int64_t Addend, 60 uint64_t SymOffset, SID SectionID); 61 62 int64_t evaluateMIPS64Relocation(const SectionEntry &Section, 63 uint64_t Offset, uint64_t Value, 64 uint32_t Type, int64_t Addend, 65 uint64_t SymOffset, SID SectionID); 66 67 void applyMIPS64Relocation(uint8_t *TargetPtr, int64_t CalculatedValue, 68 uint32_t Type); 69 70 unsigned getMaxStubSize() override { 71 if (Arch == Triple::aarch64 || Arch == Triple::aarch64_be) 72 return 20; // movz; movk; movk; movk; br 73 if (Arch == Triple::arm || Arch == Triple::thumb) 74 return 8; // 32-bit instruction and 32-bit address 75 else if (IsMipsO32ABI) 76 return 16; 77 else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) 78 return 44; 79 else if (Arch == Triple::x86_64) 80 return 6; // 2-byte jmp instruction + 32-bit relative address 81 else if (Arch == Triple::systemz) 82 return 16; 83 else 84 return 0; 85 } 86 87 unsigned getStubAlignment() override { 88 if (Arch == Triple::systemz) 89 return 8; 90 else 91 return 1; 92 } 93 94 void setMipsABI(const ObjectFile &Obj) override; 95 96 Error findPPC64TOCSection(const ELFObjectFileBase &Obj, 97 ObjSectionToIDMap &LocalSections, 98 RelocationValueRef &Rel); 99 Error findOPDEntrySection(const ELFObjectFileBase &Obj, 100 ObjSectionToIDMap &LocalSections, 101 RelocationValueRef &Rel); 102 103 size_t getGOTEntrySize(); 104 105 SectionEntry &getSection(unsigned SectionID) { return Sections[SectionID]; } 106 107 // Allocate no GOT entries for use in the given section. 108 uint64_t allocateGOTEntries(unsigned SectionID, unsigned no); 109 110 // Resolve the relvative address of GOTOffset in Section ID and place 111 // it at the given Offset 112 void resolveGOTOffsetRelocation(unsigned SectionID, uint64_t Offset, 113 uint64_t GOTOffset); 114 115 // For a GOT entry referenced from SectionID, compute a relocation entry 116 // that will place the final resolved value in the GOT slot 117 RelocationEntry computeGOTOffsetRE(unsigned SectionID, 118 uint64_t GOTOffset, 119 uint64_t SymbolOffset, 120 unsigned Type); 121 122 // Compute the address in memory where we can find the placeholder 123 void *computePlaceholderAddress(unsigned SectionID, uint64_t Offset) const; 124 125 // Split out common case for createing the RelocationEntry for when the relocation requires 126 // no particular advanced processing. 127 void processSimpleRelocation(unsigned SectionID, uint64_t Offset, unsigned RelType, RelocationValueRef Value); 128 129 // Return matching *LO16 relocation (Mips specific) 130 uint32_t getMatchingLoRelocation(uint32_t RelType, 131 bool IsLocal = false) const; 132 133 // The tentative ID for the GOT section 134 unsigned GOTSectionID; 135 136 // Records the current number of allocated slots in the GOT 137 // (This would be equivalent to GOTEntries.size() were it not for relocations 138 // that consume more than one slot) 139 unsigned CurrentGOTIndex; 140 141 // A map from section to a GOT section that has entries for section's GOT 142 // relocations. (Mips64 specific) 143 DenseMap<SID, SID> SectionToGOTMap; 144 145 // A map to avoid duplicate got entries (Mips64 specific) 146 StringMap<uint64_t> GOTSymbolOffsets; 147 148 // *HI16 relocations will be added for resolving when we find matching 149 // *LO16 part. (Mips specific) 150 SmallVector<std::pair<RelocationValueRef, RelocationEntry>, 8> PendingRelocs; 151 152 // When a module is loaded we save the SectionID of the EH frame section 153 // in a table until we receive a request to register all unregistered 154 // EH frame sections with the memory manager. 155 SmallVector<SID, 2> UnregisteredEHFrameSections; 156 SmallVector<SID, 2> RegisteredEHFrameSections; 157 158 bool relocationNeedsStub(const RelocationRef &R) const override; 159 160 public: 161 RuntimeDyldELF(RuntimeDyld::MemoryManager &MemMgr, 162 RuntimeDyld::SymbolResolver &Resolver); 163 ~RuntimeDyldELF() override; 164 165 std::unique_ptr<RuntimeDyld::LoadedObjectInfo> 166 loadObject(const object::ObjectFile &O) override; 167 168 void resolveRelocation(const RelocationEntry &RE, uint64_t Value) override; 169 Expected<relocation_iterator> 170 processRelocationRef(unsigned SectionID, relocation_iterator RelI, 171 const ObjectFile &Obj, 172 ObjSectionToIDMap &ObjSectionToID, 173 StubMap &Stubs) override; 174 bool isCompatibleFile(const object::ObjectFile &Obj) const override; 175 void registerEHFrames() override; 176 void deregisterEHFrames() override; 177 Error finalizeLoad(const ObjectFile &Obj, 178 ObjSectionToIDMap &SectionMap) override; 179 }; 180 181 } // end namespace llvm 182 183 #endif 184
