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RuntimeDyldELF.h
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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-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // ELF support for MC-JIT runtime dynamic linker.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_RUNTIMEDYLDELF_H
14 #define LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_RUNTIMEDYLDELF_H
15 
16 #include "RuntimeDyldImpl.h"
17 #include "llvm/ADT/DenseMap.h"
18 
19 using namespace llvm;
20 
21 namespace llvm {
22 namespace object {
23 class ELFObjectFileBase;
24 }
25 
27 
28  void resolveRelocation(const SectionEntry &Section, uint64_t Offset,
29  uint64_t Value, uint32_t Type, int64_t Addend,
30  uint64_t SymOffset = 0, SID SectionID = 0);
31 
32  void resolveX86_64Relocation(const SectionEntry &Section, uint64_t Offset,
33  uint64_t Value, uint32_t Type, int64_t Addend,
34  uint64_t SymOffset);
35 
36  void resolveX86Relocation(const SectionEntry &Section, uint64_t Offset,
37  uint32_t Value, uint32_t Type, int32_t Addend);
38 
39  void resolveAArch64Relocation(const SectionEntry &Section, uint64_t Offset,
40  uint64_t Value, uint32_t Type, int64_t Addend);
41 
42  bool resolveAArch64ShortBranch(unsigned SectionID, relocation_iterator RelI,
43  const RelocationValueRef &Value);
44 
45  void resolveAArch64Branch(unsigned SectionID, const RelocationValueRef &Value,
46  relocation_iterator RelI, StubMap &Stubs);
47 
48  void resolveARMRelocation(const SectionEntry &Section, uint64_t Offset,
49  uint32_t Value, uint32_t Type, int32_t Addend);
50 
51  void resolvePPC32Relocation(const SectionEntry &Section, uint64_t Offset,
52  uint64_t Value, uint32_t Type, int64_t Addend);
53 
54  void resolvePPC64Relocation(const SectionEntry &Section, uint64_t Offset,
55  uint64_t Value, uint32_t Type, int64_t Addend);
56 
57  void resolveSystemZRelocation(const SectionEntry &Section, uint64_t Offset,
58  uint64_t Value, uint32_t Type, int64_t Addend);
59 
60  void resolveBPFRelocation(const SectionEntry &Section, uint64_t Offset,
61  uint64_t Value, uint32_t Type, int64_t Addend);
62 
63  unsigned getMaxStubSize() const override {
65  return 20; // movz; movk; movk; movk; br
66  if (Arch == Triple::arm || Arch == Triple::thumb)
67  return 8; // 32-bit instruction and 32-bit address
68  else if (IsMipsO32ABI || IsMipsN32ABI)
69  return 16;
70  else if (IsMipsN64ABI)
71  return 32;
72  else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le)
73  return 44;
74  else if (Arch == Triple::x86_64)
75  return 6; // 2-byte jmp instruction + 32-bit relative address
76  else if (Arch == Triple::systemz)
77  return 16;
78  else
79  return 0;
80  }
81 
82  unsigned getStubAlignment() override {
83  if (Arch == Triple::systemz)
84  return 8;
85  else
86  return 1;
87  }
88 
89  void setMipsABI(const ObjectFile &Obj) override;
90 
91  Error findPPC64TOCSection(const object::ELFObjectFileBase &Obj,
92  ObjSectionToIDMap &LocalSections,
93  RelocationValueRef &Rel);
94  Error findOPDEntrySection(const object::ELFObjectFileBase &Obj,
95  ObjSectionToIDMap &LocalSections,
96  RelocationValueRef &Rel);
97 
98 protected:
99  size_t getGOTEntrySize() override;
100 
101 private:
102  SectionEntry &getSection(unsigned SectionID) { return Sections[SectionID]; }
103 
104  // Allocate no GOT entries for use in the given section.
105  uint64_t allocateGOTEntries(unsigned no);
106 
107  // Find GOT entry corresponding to relocation or create new one.
108  uint64_t findOrAllocGOTEntry(const RelocationValueRef &Value,
109  unsigned GOTRelType);
110 
111  // Resolve the relvative address of GOTOffset in Section ID and place
112  // it at the given Offset
113  void resolveGOTOffsetRelocation(unsigned SectionID, uint64_t Offset,
114  uint64_t GOTOffset, uint32_t Type);
115 
116  // For a GOT entry referenced from SectionID, compute a relocation entry
117  // that will place the final resolved value in the GOT slot
118  RelocationEntry computeGOTOffsetRE(uint64_t GOTOffset, uint64_t SymbolOffset,
119  unsigned Type);
120 
121  // Compute the address in memory where we can find the placeholder
122  void *computePlaceholderAddress(unsigned SectionID, uint64_t Offset) const;
123 
124  // Split out common case for createing the RelocationEntry for when the relocation requires
125  // no particular advanced processing.
126  void processSimpleRelocation(unsigned SectionID, uint64_t Offset, unsigned RelType, RelocationValueRef Value);
127 
128  // Return matching *LO16 relocation (Mips specific)
129  uint32_t getMatchingLoRelocation(uint32_t RelType,
130  bool IsLocal = false) const;
131 
132  // The tentative ID for the GOT section
133  unsigned GOTSectionID;
134 
135  // Records the current number of allocated slots in the GOT
136  // (This would be equivalent to GOTEntries.size() were it not for relocations
137  // that consume more than one slot)
138  unsigned CurrentGOTIndex;
139 
140 protected:
141  // A map from section to a GOT section that has entries for section's GOT
142  // relocations. (Mips64 specific)
144 
145 private:
146  // A map to avoid duplicate got entries (Mips64 specific)
147  StringMap<uint64_t> GOTSymbolOffsets;
148 
149  // *HI16 relocations will be added for resolving when we find matching
150  // *LO16 part. (Mips specific)
152 
153  // When a module is loaded we save the SectionID of the EH frame section
154  // in a table until we receive a request to register all unregistered
155  // EH frame sections with the memory manager.
156  SmallVector<SID, 2> UnregisteredEHFrameSections;
157 
158  // Map between GOT relocation value and corresponding GOT offset
159  std::map<RelocationValueRef, uint64_t> GOTOffsetMap;
160 
161  bool relocationNeedsGot(const RelocationRef &R) const override;
162  bool relocationNeedsStub(const RelocationRef &R) const override;
163 
164  // Process a GOTTPOFF TLS relocation for x86-64
165  // NOLINTNEXTLINE(readability-identifier-naming)
166  void processX86_64GOTTPOFFRelocation(unsigned SectionID, uint64_t Offset,
168  int64_t Addend);
169  // Process a TLSLD/TLSGD relocation for x86-64
170  // NOLINTNEXTLINE(readability-identifier-naming)
171  void processX86_64TLSRelocation(unsigned SectionID, uint64_t Offset,
173  int64_t Addend,
174  const RelocationRef &GetAddrRelocation);
175 
176 public:
179  ~RuntimeDyldELF() override;
180 
181  static std::unique_ptr<RuntimeDyldELF>
184 
185  std::unique_ptr<RuntimeDyld::LoadedObjectInfo>
186  loadObject(const object::ObjectFile &O) override;
187 
188  void resolveRelocation(const RelocationEntry &RE, uint64_t Value) override;
190  processRelocationRef(unsigned SectionID, relocation_iterator RelI,
191  const ObjectFile &Obj,
192  ObjSectionToIDMap &ObjSectionToID,
193  StubMap &Stubs) override;
194  bool isCompatibleFile(const object::ObjectFile &Obj) const override;
195  void registerEHFrames() override;
196  Error finalizeLoad(const ObjectFile &Obj,
197  ObjSectionToIDMap &SectionMap) override;
198 };
199 
200 } // end namespace llvm
201 
202 #endif
RuntimeDyldImpl.h
llvm
---------------------— PointerInfo ------------------------------------—
Definition: AllocatorList.h:23
llvm::RuntimeDyldImpl::MemMgr
RuntimeDyld::MemoryManager & MemMgr
Definition: RuntimeDyldImpl.h:244
llvm::RuntimeDyldELF::registerEHFrames
void registerEHFrames() override
Definition: RuntimeDyldELF.cpp:221
llvm::RuntimeDyldELF::isCompatibleFile
bool isCompatibleFile(const object::ObjectFile &Obj) const override
Definition: RuntimeDyldELF.cpp:2354
llvm::RuntimeDyldImpl::Sections
SectionList Sections
Definition: RuntimeDyldImpl.h:254
llvm::SmallVector
This is a 'vector' (really, a variable-sized array), optimized for the case when the array is small.
Definition: SmallVector.h:1168
llvm::Type
The instances of the Type class are immutable: once they are created, they are never changed.
Definition: Type.h:45
DenseMap.h
llvm::Triple::x86_64
@ x86_64
Definition: Triple.h:84
Offset
uint64_t Offset
Definition: ELFObjHandler.cpp:81
llvm::Expected
Tagged union holding either a T or a Error.
Definition: APFloat.h:42
llvm::RuntimeDyldImpl
Definition: RuntimeDyldImpl.h:238
llvm::RuntimeDyldImpl::IsMipsO32ABI
bool IsMipsO32ABI
Definition: RuntimeDyldImpl.h:290
llvm::object::ELFObjectFileBase
Definition: ELFObjectFile.h:49
llvm::ARMBuildAttrs::Section
@ Section
Legacy Tags.
Definition: ARMBuildAttributes.h:78
llvm::Resolver
Interface for looking up the initializer for a variable name, used by Init::resolveReferences.
Definition: Record.h:2000
llvm::RuntimeDyldELF::finalizeLoad
Error finalizeLoad(const ObjectFile &Obj, ObjSectionToIDMap &SectionMap) override
Definition: RuntimeDyldELF.cpp:2288
llvm::Triple::ArchType
ArchType
Definition: Triple.h:47
llvm::RuntimeDyldImpl::SID
unsigned SID
Definition: RuntimeDyldImpl.h:256
llvm::RuntimeDyldImpl::IsMipsN64ABI
bool IsMipsN64ABI
Definition: RuntimeDyldImpl.h:292
llvm::Triple::ppc64
@ ppc64
Definition: Triple.h:69
llvm::StringMap< uint64_t >
llvm::RelocationEntry
RelocationEntry - used to represent relocations internally in the dynamic linker.
Definition: RuntimeDyldImpl.h:117
llvm::Triple::ppc64le
@ ppc64le
Definition: Triple.h:70
llvm::RISCVFenceField::O
@ O
Definition: RISCVBaseInfo.h:192
object
bar al al movzbl eax ret Missed when stored in a memory object
Definition: README.txt:1411
uint64_t
llvm::RuntimeDyldELF::RuntimeDyldELF
RuntimeDyldELF(RuntimeDyld::MemoryManager &MemMgr, JITSymbolResolver &Resolver)
Definition: RuntimeDyldELF.cpp:216
llvm::DenseMap< SID, SID >
llvm::SectionEntry
SectionEntry - represents a section emitted into memory by the dynamic linker.
Definition: RuntimeDyldImpl.h:45
llvm::object::content_iterator
Definition: SymbolicFile.h:67
llvm::RuntimeDyldImpl::IsMipsN32ABI
bool IsMipsN32ABI
Definition: RuntimeDyldImpl.h:291
llvm::Triple::arm
@ arm
Definition: Triple.h:50
llvm::Triple::aarch64_be
@ aarch64_be
Definition: Triple.h:53
llvm::object::ObjectFile
This class is the base class for all object file types.
Definition: ObjectFile.h:228
uint32_t
llvm::Triple::thumb
@ thumb
Definition: Triple.h:81
llvm::RuntimeDyldELF::getGOTEntrySize
size_t getGOTEntrySize() override
Definition: RuntimeDyldELF.cpp:2206
llvm::RuntimeDyldELF
Definition: RuntimeDyldELF.h:26
llvm::JITSymbolResolver
Symbol resolution interface.
Definition: JITSymbol.h:371
llvm::RuntimeDyldELF::create
static std::unique_ptr< RuntimeDyldELF > create(Triple::ArchType Arch, RuntimeDyld::MemoryManager &MemMgr, JITSymbolResolver &Resolver)
Definition: RuntimeDyldELF.cpp:233
llvm::Error
Lightweight error class with error context and mandatory checking.
Definition: Error.h:157
llvm::Triple::systemz
@ systemz
Definition: Triple.h:78
llvm::RuntimeDyldImpl::Arch
Triple::ArchType Arch
Definition: RuntimeDyldImpl.h:288
llvm::RuntimeDyldELF::SectionToGOTMap
DenseMap< SID, SID > SectionToGOTMap
Definition: RuntimeDyldELF.h:143
llvm::RuntimeDyldELF::loadObject
std::unique_ptr< RuntimeDyld::LoadedObjectInfo > loadObject(const object::ObjectFile &O) override
Definition: RuntimeDyldELF.cpp:248
llvm::RuntimeDyldImpl::StubMap
std::map< RelocationValueRef, uintptr_t > StubMap
Definition: RuntimeDyldImpl.h:286
llvm::object::RelocationRef
This is a value type class that represents a single relocation in the list of relocations in the obje...
Definition: ObjectFile.h:51
llvm::RuntimeDyldELF::~RuntimeDyldELF
~RuntimeDyldELF() override
Definition: RuntimeDyldELF.cpp:219
llvm::RelocationValueRef
Definition: RuntimeDyldImpl.h:190
llvm::Value
LLVM Value Representation.
Definition: Value.h:75
llvm::Triple::aarch64
@ aarch64
Definition: Triple.h:52
llvm::RuntimeDyldELF::processRelocationRef
Expected< relocation_iterator > processRelocationRef(unsigned SectionID, relocation_iterator RelI, const ObjectFile &Obj, ObjSectionToIDMap &ObjSectionToID, StubMap &Stubs) override
Parses one or more object file relocations (some object files use relocation pairs) and stores it to ...
Definition: RuntimeDyldELF.cpp:1204
llvm::RuntimeDyldImpl::ObjSectionToIDMap
std::map< SectionRef, unsigned > ObjSectionToIDMap
Definition: RuntimeDyldImpl.h:261
llvm::object::resolveRelocation
uint64_t resolveRelocation(RelocationResolver Resolver, const RelocationRef &R, uint64_t S, uint64_t LocData)
Definition: RelocationResolver.cpp:736
llvm::RuntimeDyld::MemoryManager
Memory Management.
Definition: RuntimeDyld.h:92