1 //===-- RuntimeDyldCOFFX86_64.h --- COFF/X86_64 specific code ---*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // COFF x86_x64 support for MC-JIT runtime dynamic linker.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_TARGETS_RUNTIMEDYLDCOFF86_64_H
15 #define LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_TARGETS_RUNTIMEDYLDCOFF86_64_H
17 #include "llvm/Object/COFF.h"
18 #include "llvm/Support/COFF.h"
19 #include "../RuntimeDyldCOFF.h"
21 #define DEBUG_TYPE "dyld"
25 class RuntimeDyldCOFFX86_64 : public RuntimeDyldCOFF {
28 // When a module is loaded we save the SectionID of the unwind
29 // sections in a table until we receive a request to register all
30 // unregisteredEH frame sections with the memory manager.
31 SmallVector<SID, 2> UnregisteredEHFrameSections;
32 SmallVector<SID, 2> RegisteredEHFrameSections;
35 RuntimeDyldCOFFX86_64(RuntimeDyld::MemoryManager &MM,
36 RuntimeDyld::SymbolResolver &Resolver)
37 : RuntimeDyldCOFF(MM, Resolver) {}
39 unsigned getMaxStubSize() override {
40 return 6; // 2-byte jmp instruction + 32-bit relative address
43 // The target location for the relocation is described by RE.SectionID and
44 // RE.Offset. RE.SectionID can be used to find the SectionEntry. Each
45 // SectionEntry has three members describing its location.
46 // SectionEntry::Address is the address at which the section has been loaded
47 // into memory in the current (host) process. SectionEntry::LoadAddress is
48 // the address that the section will have in the target process.
49 // SectionEntry::ObjAddress is the address of the bits for this section in the
50 // original emitted object image (also in the current address space).
52 // Relocations will be applied as if the section were loaded at
53 // SectionEntry::LoadAddress, but they will be applied at an address based
54 // on SectionEntry::Address. SectionEntry::ObjAddress will be used to refer
55 // to Target memory contents if they are required for value calculations.
57 // The Value parameter here is the load address of the symbol for the
58 // relocation to be applied. For relocations which refer to symbols in the
59 // current object Value will be the LoadAddress of the section in which
60 // the symbol resides (RE.Addend provides additional information about the
61 // symbol location). For external symbols, Value will be the address of the
62 // symbol in the target address space.
63 void resolveRelocation(const RelocationEntry &RE, uint64_t Value) override {
64 const SectionEntry &Section = Sections[RE.SectionID];
65 uint8_t *Target = Section.Address + RE.Offset;
69 case COFF::IMAGE_REL_AMD64_REL32:
70 case COFF::IMAGE_REL_AMD64_REL32_1:
71 case COFF::IMAGE_REL_AMD64_REL32_2:
72 case COFF::IMAGE_REL_AMD64_REL32_3:
73 case COFF::IMAGE_REL_AMD64_REL32_4:
74 case COFF::IMAGE_REL_AMD64_REL32_5: {
75 uint32_t *TargetAddress = (uint32_t *)Target;
76 uint64_t FinalAddress = Section.LoadAddress + RE.Offset;
77 // Delta is the distance from the start of the reloc to the end of the
78 // instruction with the reloc.
79 uint64_t Delta = 4 + (RE.RelType - COFF::IMAGE_REL_AMD64_REL32);
80 Value -= FinalAddress + Delta;
81 uint64_t Result = Value + RE.Addend;
82 assert(((int64_t)Result <= INT32_MAX) && "Relocation overflow");
83 assert(((int64_t)Result >= INT32_MIN) && "Relocation underflow");
84 *TargetAddress = Result;
88 case COFF::IMAGE_REL_AMD64_ADDR32NB: {
89 // Note ADDR32NB requires a well-established notion of
90 // image base. This address must be less than or equal
91 // to every section's load address, and all sections must be
92 // within a 32 bit offset from the base.
94 // For now we just set these to zero.
95 uint32_t *TargetAddress = (uint32_t *)Target;
100 case COFF::IMAGE_REL_AMD64_ADDR64: {
101 uint64_t *TargetAddress = (uint64_t *)Target;
102 *TargetAddress = Value + RE.Addend;
107 llvm_unreachable("Relocation type not implemented yet!");
112 relocation_iterator processRelocationRef(unsigned SectionID,
113 relocation_iterator RelI,
114 const ObjectFile &Obj,
115 ObjSectionToIDMap &ObjSectionToID,
116 StubMap &Stubs) override {
117 // If possible, find the symbol referred to in the relocation,
118 // and the section that contains it.
119 symbol_iterator Symbol = RelI->getSymbol();
120 if (Symbol == Obj.symbol_end())
121 report_fatal_error("Unknown symbol in relocation");
122 section_iterator SecI(Obj.section_end());
123 Symbol->getSection(SecI);
124 // If there is no section, this must be an external reference.
125 const bool IsExtern = SecI == Obj.section_end();
127 // Determine the Addend used to adjust the relocation value.
128 uint64_t RelType = RelI->getType();
129 uint64_t Offset = RelI->getOffset();
131 SectionEntry &Section = Sections[SectionID];
132 uintptr_t ObjTarget = Section.ObjAddress + Offset;
136 case COFF::IMAGE_REL_AMD64_REL32:
137 case COFF::IMAGE_REL_AMD64_REL32_1:
138 case COFF::IMAGE_REL_AMD64_REL32_2:
139 case COFF::IMAGE_REL_AMD64_REL32_3:
140 case COFF::IMAGE_REL_AMD64_REL32_4:
141 case COFF::IMAGE_REL_AMD64_REL32_5:
142 case COFF::IMAGE_REL_AMD64_ADDR32NB: {
143 uint32_t *Displacement = (uint32_t *)ObjTarget;
144 Addend = *Displacement;
148 case COFF::IMAGE_REL_AMD64_ADDR64: {
149 uint64_t *Displacement = (uint64_t *)ObjTarget;
150 Addend = *Displacement;
158 ErrorOr<StringRef> TargetNameOrErr = Symbol->getName();
159 if (std::error_code EC = TargetNameOrErr.getError())
160 report_fatal_error(EC.message());
161 StringRef TargetName = *TargetNameOrErr;
163 DEBUG(dbgs() << "\t\tIn Section " << SectionID << " Offset " << Offset
164 << " RelType: " << RelType << " TargetName: " << TargetName
165 << " Addend " << Addend << "\n");
168 RelocationEntry RE(SectionID, Offset, RelType, Addend);
169 addRelocationForSymbol(RE, TargetName);
171 bool IsCode = SecI->isText();
172 unsigned TargetSectionID =
173 findOrEmitSection(Obj, *SecI, IsCode, ObjSectionToID);
174 uint64_t TargetOffset = getSymbolOffset(*Symbol);
175 RelocationEntry RE(SectionID, Offset, RelType, TargetOffset + Addend);
176 addRelocationForSection(RE, TargetSectionID);
182 unsigned getStubAlignment() override { return 1; }
183 void registerEHFrames() override {
184 for (auto const &EHFrameSID : UnregisteredEHFrameSections) {
185 uint8_t *EHFrameAddr = Sections[EHFrameSID].Address;
186 uint64_t EHFrameLoadAddr = Sections[EHFrameSID].LoadAddress;
187 size_t EHFrameSize = Sections[EHFrameSID].Size;
188 MemMgr.registerEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
189 RegisteredEHFrameSections.push_back(EHFrameSID);
191 UnregisteredEHFrameSections.clear();
193 void deregisterEHFrames() override {
196 void finalizeLoad(const ObjectFile &Obj,
197 ObjSectionToIDMap &SectionMap) override {
198 // Look for and record the EH frame section IDs.
199 for (const auto &SectionPair : SectionMap) {
200 const SectionRef &Section = SectionPair.first;
202 Check(Section.getName(Name));
203 // Note unwind info is split across .pdata and .xdata, so this
204 // may not be sufficiently general for all users.
205 if (Name == ".xdata") {
206 UnregisteredEHFrameSections.push_back(SectionPair.second);
212 } // end namespace llvm