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1//===-- RuntimeDyldELF.h - Run-time dynamic linker for MC-JIT ---*- C++ -*-===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8//9// ELF support for MC-JIT runtime dynamic linker.10//11//===----------------------------------------------------------------------===//12 13#ifndef LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_RUNTIMEDYLDELF_H14#define LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_RUNTIMEDYLDELF_H15 16#include "RuntimeDyldImpl.h"17#include "llvm/ADT/DenseMap.h"18 19namespace llvm {20namespace object {21class ELFObjectFileBase;22}23 24class RuntimeDyldELF : public RuntimeDyldImpl {25 26 void resolveRelocation(const SectionEntry &Section, uint64_t Offset,27 uint64_t Value, uint32_t Type, int64_t Addend,28 uint64_t SymOffset = 0, SID SectionID = 0);29 30 void resolveX86_64Relocation(const SectionEntry &Section, uint64_t Offset,31 uint64_t Value, uint32_t Type, int64_t Addend,32 uint64_t SymOffset);33 34 void resolveX86Relocation(const SectionEntry &Section, uint64_t Offset,35 uint32_t Value, uint32_t Type, int32_t Addend);36 37 void resolveAArch64Relocation(const SectionEntry &Section, uint64_t Offset,38 uint64_t Value, uint32_t Type, int64_t Addend);39 40 bool resolveAArch64ShortBranch(unsigned SectionID, relocation_iterator RelI,41 const RelocationValueRef &Value);42 43 void resolveAArch64Branch(unsigned SectionID, const RelocationValueRef &Value,44 relocation_iterator RelI, StubMap &Stubs);45 46 void resolveARMRelocation(const SectionEntry &Section, uint64_t Offset,47 uint32_t Value, uint32_t Type, int32_t Addend);48 49 void resolveLoongArch64Relocation(const SectionEntry &Section,50 uint64_t Offset, uint64_t Value,51 uint32_t Type, int64_t Addend);52 53 bool resolveLoongArch64ShortBranch(unsigned SectionID,54 relocation_iterator RelI,55 const RelocationValueRef &Value);56 57 void resolveLoongArch64Branch(unsigned SectionID,58 const RelocationValueRef &Value,59 relocation_iterator RelI, StubMap &Stubs);60 61 void resolvePPC32Relocation(const SectionEntry &Section, uint64_t Offset,62 uint64_t Value, uint32_t Type, int64_t Addend);63 64 void resolvePPC64Relocation(const SectionEntry &Section, uint64_t Offset,65 uint64_t Value, uint32_t Type, int64_t Addend);66 67 void resolveSystemZRelocation(const SectionEntry &Section, uint64_t Offset,68 uint64_t Value, uint32_t Type, int64_t Addend);69 70 void resolveBPFRelocation(const SectionEntry &Section, uint64_t Offset,71 uint64_t Value, uint32_t Type, int64_t Addend);72 73 void resolveRISCVRelocation(const SectionEntry &Section, uint64_t Offset,74 uint64_t Value, uint32_t Type, int64_t Addend,75 SID SectionID);76 77 unsigned getMaxStubSize() const override {78 if (Arch == Triple::aarch64 || Arch == Triple::aarch64_be)79 return 20; // movz; movk; movk; movk; br80 if (Arch == Triple::arm || Arch == Triple::thumb)81 return 8; // 32-bit instruction and 32-bit address82 else if (IsMipsO32ABI || IsMipsN32ABI)83 return 16;84 else if (IsMipsN64ABI)85 return 32;86 if (Arch == Triple::loongarch64)87 return 20; // lu12i.w; ori; lu32i.d; lu52i.d; jr88 else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le)89 return 44;90 else if (Arch == Triple::x86_64)91 return 6; // 2-byte jmp instruction + 32-bit relative address92 else if (Arch == Triple::systemz)93 return 16;94 else95 return 0;96 }97 98 Align getStubAlignment() override {99 if (Arch == Triple::systemz)100 return Align(8);101 else102 return Align(1);103 }104 105 void setMipsABI(const ObjectFile &Obj) override;106 107 Error findPPC64TOCSection(const object::ELFObjectFileBase &Obj,108 ObjSectionToIDMap &LocalSections,109 RelocationValueRef &Rel);110 Error findOPDEntrySection(const object::ELFObjectFileBase &Obj,111 ObjSectionToIDMap &LocalSections,112 RelocationValueRef &Rel);113 114protected:115 size_t getGOTEntrySize() override;116 117private:118 SectionEntry &getSection(unsigned SectionID) { return Sections[SectionID]; }119 120 // Allocate no GOT entries for use in the given section.121 uint64_t allocateGOTEntries(unsigned no);122 123 // Find GOT entry corresponding to relocation or create new one.124 uint64_t findOrAllocGOTEntry(const RelocationValueRef &Value,125 unsigned GOTRelType);126 127 // Resolve the relative address of GOTOffset in Section ID and place128 // it at the given Offset129 void resolveGOTOffsetRelocation(unsigned SectionID, uint64_t Offset,130 uint64_t GOTOffset, uint32_t Type);131 132 // For a GOT entry referenced from SectionID, compute a relocation entry133 // that will place the final resolved value in the GOT slot134 RelocationEntry computeGOTOffsetRE(uint64_t GOTOffset, uint64_t SymbolOffset,135 unsigned Type);136 137 // Compute the address in memory where we can find the placeholder138 void *computePlaceholderAddress(unsigned SectionID, uint64_t Offset) const;139 140 // Split out common case for creating the RelocationEntry for when the141 // relocation requires no particular advanced processing.142 void processSimpleRelocation(unsigned SectionID, uint64_t Offset, unsigned RelType, RelocationValueRef Value);143 144 // Return matching *LO16 relocation (Mips specific)145 uint32_t getMatchingLoRelocation(uint32_t RelType,146 bool IsLocal = false) const;147 148 // The tentative ID for the GOT section149 unsigned GOTSectionID;150 151 // Records the current number of allocated slots in the GOT152 // (This would be equivalent to GOTEntries.size() were it not for relocations153 // that consume more than one slot)154 unsigned CurrentGOTIndex;155 156protected:157 // A map from section to a GOT section that has entries for section's GOT158 // relocations. (Mips64 specific)159 DenseMap<SID, SID> SectionToGOTMap;160 161private:162 // A map to avoid duplicate got entries (Mips64 specific)163 StringMap<uint64_t> GOTSymbolOffsets;164 165 // *HI16 relocations will be added for resolving when we find matching166 // *LO16 part. (Mips specific)167 //168 // *HI20 relocations will be added for resolving when we find matching169 // *LO12 part. (RISC-V specific)170 SmallVector<std::pair<RelocationValueRef, RelocationEntry>, 8> PendingRelocs;171 172 // When a module is loaded we save the SectionID of the EH frame section173 // in a table until we receive a request to register all unregistered174 // EH frame sections with the memory manager.175 SmallVector<SID, 2> UnregisteredEHFrameSections;176 177 // Map between GOT relocation value and corresponding GOT offset178 std::map<RelocationValueRef, uint64_t> GOTOffsetMap;179 180 /// The ID of the current IFunc stub section181 unsigned IFuncStubSectionID = 0;182 /// The current offset into the IFunc stub section183 uint64_t IFuncStubOffset = 0;184 185 /// A IFunc stub and its original symbol186 struct IFuncStub {187 /// The offset of this stub in the IFunc stub section188 uint64_t StubOffset;189 /// The symbol table entry of the original symbol190 SymbolTableEntry OriginalSymbol;191 };192 193 /// The IFunc stubs194 SmallVector<IFuncStub, 2> IFuncStubs;195 196 /// Create the code for the IFunc resolver at the given address. This code197 /// works together with the stubs created in createIFuncStub() to call the198 /// resolver function and then jump to the real function address.199 /// It must not be larger than 64B.200 void createIFuncResolver(uint8_t *Addr) const;201 /// Create the code for an IFunc stub for the IFunc that is defined in202 /// section IFuncSectionID at offset IFuncOffset. The IFunc resolver created203 /// by createIFuncResolver() is defined in the section IFuncStubSectionID at204 /// offset IFuncResolverOffset. The code should be written into the section205 /// with the id IFuncStubSectionID at the offset IFuncStubOffset.206 void createIFuncStub(unsigned IFuncStubSectionID,207 uint64_t IFuncResolverOffset, uint64_t IFuncStubOffset,208 unsigned IFuncSectionID, uint64_t IFuncOffset);209 /// Return the maximum size of a stub created by createIFuncStub()210 unsigned getMaxIFuncStubSize() const;211 212 void processNewSymbol(const SymbolRef &ObjSymbol,213 SymbolTableEntry &Entry) override;214 bool relocationNeedsGot(const RelocationRef &R) const override;215 bool relocationNeedsStub(const RelocationRef &R) const override;216 217 // Process a GOTTPOFF TLS relocation for x86-64218 // NOLINTNEXTLINE(readability-identifier-naming)219 void processX86_64GOTTPOFFRelocation(unsigned SectionID, uint64_t Offset,220 RelocationValueRef Value,221 int64_t Addend);222 // Process a TLSLD/TLSGD relocation for x86-64223 // NOLINTNEXTLINE(readability-identifier-naming)224 void processX86_64TLSRelocation(unsigned SectionID, uint64_t Offset,225 uint64_t RelType, RelocationValueRef Value,226 int64_t Addend,227 const RelocationRef &GetAddrRelocation);228 229public:230 RuntimeDyldELF(RuntimeDyld::MemoryManager &MemMgr,231 JITSymbolResolver &Resolver);232 ~RuntimeDyldELF() override;233 234 static std::unique_ptr<RuntimeDyldELF>235 create(Triple::ArchType Arch, RuntimeDyld::MemoryManager &MemMgr,236 JITSymbolResolver &Resolver);237 238 std::unique_ptr<RuntimeDyld::LoadedObjectInfo>239 loadObject(const object::ObjectFile &O) override;240 241 void resolveRelocation(const RelocationEntry &RE, uint64_t Value) override;242 Expected<relocation_iterator>243 processRelocationRef(unsigned SectionID, relocation_iterator RelI,244 const ObjectFile &Obj,245 ObjSectionToIDMap &ObjSectionToID,246 StubMap &Stubs) override;247 bool isCompatibleFile(const object::ObjectFile &Obj) const override;248 void registerEHFrames() override;249 Error finalizeLoad(const ObjectFile &Obj,250 ObjSectionToIDMap &SectionMap) override;251};252 253} // end namespace llvm254 255#endif // LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_RUNTIMEDYLDELF_H256