1283625Sdim//===-- RuntimeDyldCOFFX86_64.h --- COFF/X86_64 specific code ---*- C++ -*-===// 2283625Sdim// 3353358Sdim// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4353358Sdim// See https://llvm.org/LICENSE.txt for license information. 5353358Sdim// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6283625Sdim// 7283625Sdim//===----------------------------------------------------------------------===// 8283625Sdim// 9283625Sdim// COFF x86_x64 support for MC-JIT runtime dynamic linker. 10283625Sdim// 11283625Sdim//===----------------------------------------------------------------------===// 12283625Sdim 13283625Sdim#ifndef LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_TARGETS_RUNTIMEDYLDCOFF86_64_H 14283625Sdim#define LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_TARGETS_RUNTIMEDYLDCOFF86_64_H 15283625Sdim 16321369Sdim#include "../RuntimeDyldCOFF.h" 17321369Sdim#include "llvm/BinaryFormat/COFF.h" 18283625Sdim#include "llvm/Object/COFF.h" 19283625Sdim 20283625Sdim#define DEBUG_TYPE "dyld" 21283625Sdim 22283625Sdimnamespace llvm { 23283625Sdim 24283625Sdimclass RuntimeDyldCOFFX86_64 : public RuntimeDyldCOFF { 25283625Sdim 26283625Sdimprivate: 27283625Sdim // When a module is loaded we save the SectionID of the unwind 28283625Sdim // sections in a table until we receive a request to register all 29283625Sdim // unregisteredEH frame sections with the memory manager. 30283625Sdim SmallVector<SID, 2> UnregisteredEHFrameSections; 31283625Sdim SmallVector<SID, 2> RegisteredEHFrameSections; 32341825Sdim uint64_t ImageBase; 33283625Sdim 34341825Sdim // Fake an __ImageBase pointer by returning the section with the lowest adress 35341825Sdim uint64_t getImageBase() { 36341825Sdim if (!ImageBase) { 37341825Sdim ImageBase = std::numeric_limits<uint64_t>::max(); 38341825Sdim for (const SectionEntry &Section : Sections) 39344779Sdim // The Sections list may contain sections that weren't loaded for 40344779Sdim // whatever reason: they may be debug sections, and ProcessAllSections 41344779Sdim // is false, or they may be sections that contain 0 bytes. If the 42344779Sdim // section isn't loaded, the load address will be 0, and it should not 43344779Sdim // be included in the ImageBase calculation. 44344779Sdim if (Section.getLoadAddress() != 0) 45344779Sdim ImageBase = std::min(ImageBase, Section.getLoadAddress()); 46341825Sdim } 47341825Sdim return ImageBase; 48341825Sdim } 49341825Sdim 50341825Sdim void write32BitOffset(uint8_t *Target, int64_t Addend, uint64_t Delta) { 51341825Sdim uint64_t Result = Addend + Delta; 52341825Sdim assert(Result <= UINT32_MAX && "Relocation overflow"); 53341825Sdim writeBytesUnaligned(Result, Target, 4); 54341825Sdim } 55341825Sdim 56283625Sdimpublic: 57283625Sdim RuntimeDyldCOFFX86_64(RuntimeDyld::MemoryManager &MM, 58314564Sdim JITSymbolResolver &Resolver) 59341825Sdim : RuntimeDyldCOFF(MM, Resolver), ImageBase(0) {} 60283625Sdim 61341825Sdim unsigned getStubAlignment() override { return 1; } 62283625Sdim 63341825Sdim // 2-byte jmp instruction + 32-bit relative address + 64-bit absolute jump 64353358Sdim unsigned getMaxStubSize() const override { return 14; } 65341825Sdim 66283625Sdim // The target location for the relocation is described by RE.SectionID and 67283625Sdim // RE.Offset. RE.SectionID can be used to find the SectionEntry. Each 68283625Sdim // SectionEntry has three members describing its location. 69283625Sdim // SectionEntry::Address is the address at which the section has been loaded 70283625Sdim // into memory in the current (host) process. SectionEntry::LoadAddress is 71283625Sdim // the address that the section will have in the target process. 72283625Sdim // SectionEntry::ObjAddress is the address of the bits for this section in the 73283625Sdim // original emitted object image (also in the current address space). 74283625Sdim // 75283625Sdim // Relocations will be applied as if the section were loaded at 76283625Sdim // SectionEntry::LoadAddress, but they will be applied at an address based 77283625Sdim // on SectionEntry::Address. SectionEntry::ObjAddress will be used to refer 78283625Sdim // to Target memory contents if they are required for value calculations. 79283625Sdim // 80283625Sdim // The Value parameter here is the load address of the symbol for the 81283625Sdim // relocation to be applied. For relocations which refer to symbols in the 82283625Sdim // current object Value will be the LoadAddress of the section in which 83283625Sdim // the symbol resides (RE.Addend provides additional information about the 84283625Sdim // symbol location). For external symbols, Value will be the address of the 85283625Sdim // symbol in the target address space. 86283625Sdim void resolveRelocation(const RelocationEntry &RE, uint64_t Value) override { 87283625Sdim const SectionEntry &Section = Sections[RE.SectionID]; 88296417Sdim uint8_t *Target = Section.getAddressWithOffset(RE.Offset); 89283625Sdim 90283625Sdim switch (RE.RelType) { 91283625Sdim 92283625Sdim case COFF::IMAGE_REL_AMD64_REL32: 93283625Sdim case COFF::IMAGE_REL_AMD64_REL32_1: 94283625Sdim case COFF::IMAGE_REL_AMD64_REL32_2: 95283625Sdim case COFF::IMAGE_REL_AMD64_REL32_3: 96283625Sdim case COFF::IMAGE_REL_AMD64_REL32_4: 97283625Sdim case COFF::IMAGE_REL_AMD64_REL32_5: { 98296417Sdim uint64_t FinalAddress = Section.getLoadAddressWithOffset(RE.Offset); 99283625Sdim // Delta is the distance from the start of the reloc to the end of the 100283625Sdim // instruction with the reloc. 101283625Sdim uint64_t Delta = 4 + (RE.RelType - COFF::IMAGE_REL_AMD64_REL32); 102283625Sdim Value -= FinalAddress + Delta; 103283625Sdim uint64_t Result = Value + RE.Addend; 104283625Sdim assert(((int64_t)Result <= INT32_MAX) && "Relocation overflow"); 105283625Sdim assert(((int64_t)Result >= INT32_MIN) && "Relocation underflow"); 106296417Sdim writeBytesUnaligned(Result, Target, 4); 107283625Sdim break; 108283625Sdim } 109283625Sdim 110283625Sdim case COFF::IMAGE_REL_AMD64_ADDR32NB: { 111341825Sdim // ADDR32NB requires an offset less than 2GB from 'ImageBase'. 112341825Sdim // The MemoryManager can make sure this is always true by forcing the 113341825Sdim // memory layout to be: CodeSection < ReadOnlySection < ReadWriteSection. 114341825Sdim const uint64_t ImageBase = getImageBase(); 115341825Sdim if (Value < ImageBase || ((Value - ImageBase) > UINT32_MAX)) { 116341825Sdim llvm::errs() << "IMAGE_REL_AMD64_ADDR32NB relocation requires an" 117341825Sdim << "ordered section layout.\n"; 118341825Sdim write32BitOffset(Target, 0, 0); 119341825Sdim } else { 120341825Sdim write32BitOffset(Target, RE.Addend, Value - ImageBase); 121341825Sdim } 122283625Sdim break; 123283625Sdim } 124283625Sdim 125283625Sdim case COFF::IMAGE_REL_AMD64_ADDR64: { 126296417Sdim writeBytesUnaligned(Value + RE.Addend, Target, 8); 127283625Sdim break; 128283625Sdim } 129283625Sdim 130344779Sdim case COFF::IMAGE_REL_AMD64_SECREL: { 131344779Sdim assert(static_cast<int64_t>(RE.Addend) <= INT32_MAX && "Relocation overflow"); 132344779Sdim assert(static_cast<int64_t>(RE.Addend) >= INT32_MIN && "Relocation underflow"); 133344779Sdim writeBytesUnaligned(RE.Addend, Target, 4); 134344779Sdim break; 135344779Sdim } 136344779Sdim 137283625Sdim default: 138283625Sdim llvm_unreachable("Relocation type not implemented yet!"); 139283625Sdim break; 140283625Sdim } 141283625Sdim } 142283625Sdim 143341825Sdim std::tuple<uint64_t, uint64_t, uint64_t> 144341825Sdim generateRelocationStub(unsigned SectionID, StringRef TargetName, 145341825Sdim uint64_t Offset, uint64_t RelType, uint64_t Addend, 146341825Sdim StubMap &Stubs) { 147341825Sdim uintptr_t StubOffset; 148341825Sdim SectionEntry &Section = Sections[SectionID]; 149341825Sdim 150341825Sdim RelocationValueRef OriginalRelValueRef; 151341825Sdim OriginalRelValueRef.SectionID = SectionID; 152341825Sdim OriginalRelValueRef.Offset = Offset; 153341825Sdim OriginalRelValueRef.Addend = Addend; 154341825Sdim OriginalRelValueRef.SymbolName = TargetName.data(); 155341825Sdim 156341825Sdim auto Stub = Stubs.find(OriginalRelValueRef); 157341825Sdim if (Stub == Stubs.end()) { 158341825Sdim LLVM_DEBUG(dbgs() << " Create a new stub function for " 159341825Sdim << TargetName.data() << "\n"); 160341825Sdim 161341825Sdim StubOffset = Section.getStubOffset(); 162341825Sdim Stubs[OriginalRelValueRef] = StubOffset; 163341825Sdim createStubFunction(Section.getAddressWithOffset(StubOffset)); 164341825Sdim Section.advanceStubOffset(getMaxStubSize()); 165341825Sdim } else { 166341825Sdim LLVM_DEBUG(dbgs() << " Stub function found for " << TargetName.data() 167341825Sdim << "\n"); 168341825Sdim StubOffset = Stub->second; 169341825Sdim } 170341825Sdim 171341825Sdim // FIXME: If RelType == COFF::IMAGE_REL_AMD64_ADDR32NB we should be able 172341825Sdim // to ignore the __ImageBase requirement and just forward to the stub 173341825Sdim // directly as an offset of this section: 174341825Sdim // write32BitOffset(Section.getAddressWithOffset(Offset), 0, StubOffset); 175341825Sdim // .xdata exception handler's aren't having this though. 176341825Sdim 177341825Sdim // Resolve original relocation to stub function. 178341825Sdim const RelocationEntry RE(SectionID, Offset, RelType, Addend); 179341825Sdim resolveRelocation(RE, Section.getLoadAddressWithOffset(StubOffset)); 180341825Sdim 181341825Sdim // adjust relocation info so resolution writes to the stub function 182341825Sdim Addend = 0; 183341825Sdim Offset = StubOffset + 6; 184341825Sdim RelType = COFF::IMAGE_REL_AMD64_ADDR64; 185341825Sdim 186341825Sdim return std::make_tuple(Offset, RelType, Addend); 187341825Sdim } 188341825Sdim 189353358Sdim Expected<object::relocation_iterator> 190309124Sdim processRelocationRef(unsigned SectionID, 191353358Sdim object::relocation_iterator RelI, 192353358Sdim const object::ObjectFile &Obj, 193309124Sdim ObjSectionToIDMap &ObjSectionToID, 194309124Sdim StubMap &Stubs) override { 195283625Sdim // If possible, find the symbol referred to in the relocation, 196283625Sdim // and the section that contains it. 197353358Sdim object::symbol_iterator Symbol = RelI->getSymbol(); 198283625Sdim if (Symbol == Obj.symbol_end()) 199283625Sdim report_fatal_error("Unknown symbol in relocation"); 200309124Sdim auto SectionOrError = Symbol->getSection(); 201309124Sdim if (!SectionOrError) 202309124Sdim return SectionOrError.takeError(); 203353358Sdim object::section_iterator SecI = *SectionOrError; 204283625Sdim // If there is no section, this must be an external reference. 205283625Sdim const bool IsExtern = SecI == Obj.section_end(); 206283625Sdim 207283625Sdim // Determine the Addend used to adjust the relocation value. 208285181Sdim uint64_t RelType = RelI->getType(); 209285181Sdim uint64_t Offset = RelI->getOffset(); 210283625Sdim uint64_t Addend = 0; 211283625Sdim SectionEntry &Section = Sections[SectionID]; 212296417Sdim uintptr_t ObjTarget = Section.getObjAddress() + Offset; 213283625Sdim 214341825Sdim Expected<StringRef> TargetNameOrErr = Symbol->getName(); 215341825Sdim if (!TargetNameOrErr) 216341825Sdim return TargetNameOrErr.takeError(); 217341825Sdim StringRef TargetName = *TargetNameOrErr; 218341825Sdim 219283625Sdim switch (RelType) { 220283625Sdim 221283625Sdim case COFF::IMAGE_REL_AMD64_REL32: 222283625Sdim case COFF::IMAGE_REL_AMD64_REL32_1: 223283625Sdim case COFF::IMAGE_REL_AMD64_REL32_2: 224283625Sdim case COFF::IMAGE_REL_AMD64_REL32_3: 225283625Sdim case COFF::IMAGE_REL_AMD64_REL32_4: 226283625Sdim case COFF::IMAGE_REL_AMD64_REL32_5: 227283625Sdim case COFF::IMAGE_REL_AMD64_ADDR32NB: { 228296417Sdim uint8_t *Displacement = (uint8_t *)ObjTarget; 229296417Sdim Addend = readBytesUnaligned(Displacement, 4); 230341825Sdim 231341825Sdim if (IsExtern) 232341825Sdim std::tie(Offset, RelType, Addend) = generateRelocationStub( 233341825Sdim SectionID, TargetName, Offset, RelType, Addend, Stubs); 234341825Sdim 235283625Sdim break; 236283625Sdim } 237283625Sdim 238283625Sdim case COFF::IMAGE_REL_AMD64_ADDR64: { 239296417Sdim uint8_t *Displacement = (uint8_t *)ObjTarget; 240296417Sdim Addend = readBytesUnaligned(Displacement, 8); 241283625Sdim break; 242283625Sdim } 243283625Sdim 244283625Sdim default: 245283625Sdim break; 246283625Sdim } 247283625Sdim 248341825Sdim LLVM_DEBUG(dbgs() << "\t\tIn Section " << SectionID << " Offset " << Offset 249341825Sdim << " RelType: " << RelType << " TargetName: " 250341825Sdim << TargetName << " Addend " << Addend << "\n"); 251283625Sdim 252283625Sdim if (IsExtern) { 253283625Sdim RelocationEntry RE(SectionID, Offset, RelType, Addend); 254283625Sdim addRelocationForSymbol(RE, TargetName); 255283625Sdim } else { 256283625Sdim bool IsCode = SecI->isText(); 257309124Sdim unsigned TargetSectionID; 258309124Sdim if (auto TargetSectionIDOrErr = 259309124Sdim findOrEmitSection(Obj, *SecI, IsCode, ObjSectionToID)) 260309124Sdim TargetSectionID = *TargetSectionIDOrErr; 261309124Sdim else 262309124Sdim return TargetSectionIDOrErr.takeError(); 263283625Sdim uint64_t TargetOffset = getSymbolOffset(*Symbol); 264283625Sdim RelocationEntry RE(SectionID, Offset, RelType, TargetOffset + Addend); 265283625Sdim addRelocationForSection(RE, TargetSectionID); 266283625Sdim } 267283625Sdim 268283625Sdim return ++RelI; 269283625Sdim } 270283625Sdim 271283625Sdim void registerEHFrames() override { 272283625Sdim for (auto const &EHFrameSID : UnregisteredEHFrameSections) { 273296417Sdim uint8_t *EHFrameAddr = Sections[EHFrameSID].getAddress(); 274296417Sdim uint64_t EHFrameLoadAddr = Sections[EHFrameSID].getLoadAddress(); 275296417Sdim size_t EHFrameSize = Sections[EHFrameSID].getSize(); 276283625Sdim MemMgr.registerEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize); 277283625Sdim RegisteredEHFrameSections.push_back(EHFrameSID); 278283625Sdim } 279283625Sdim UnregisteredEHFrameSections.clear(); 280283625Sdim } 281341825Sdim 282353358Sdim Error finalizeLoad(const object::ObjectFile &Obj, 283309124Sdim ObjSectionToIDMap &SectionMap) override { 284283625Sdim // Look for and record the EH frame section IDs. 285283625Sdim for (const auto &SectionPair : SectionMap) { 286353358Sdim const object::SectionRef &Section = SectionPair.first; 287360784Sdim Expected<StringRef> NameOrErr = Section.getName(); 288360784Sdim if (!NameOrErr) 289360784Sdim return NameOrErr.takeError(); 290341825Sdim 291341825Sdim // Note unwind info is stored in .pdata but often points to .xdata 292341825Sdim // with an IMAGE_REL_AMD64_ADDR32NB relocation. Using a memory manager 293341825Sdim // that keeps sections ordered in relation to __ImageBase is necessary. 294360784Sdim if ((*NameOrErr) == ".pdata") 295283625Sdim UnregisteredEHFrameSections.push_back(SectionPair.second); 296283625Sdim } 297309124Sdim return Error::success(); 298283625Sdim } 299283625Sdim}; 300283625Sdim 301283625Sdim} // end namespace llvm 302283625Sdim 303283625Sdim#undef DEBUG_TYPE 304283625Sdim 305283625Sdim#endif 306