1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
| //===-- RuntimeDyldMachOX86_64.h ---- MachO/X86_64 specific code. -*- C++ -*-=//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_TARGETS_RUNTIMEDYLDMACHOX86_64_H
#define LLVM_LIB_EXECUTIONENGINE_RUNTIMEDYLD_TARGETS_RUNTIMEDYLDMACHOX86_64_H
#include "../RuntimeDyldMachO.h"
#include <string>
#define DEBUG_TYPE "dyld"
namespace llvm {
class RuntimeDyldMachOX86_64
: public RuntimeDyldMachOCRTPBase<RuntimeDyldMachOX86_64> {
public:
typedef uint64_t TargetPtrT;
RuntimeDyldMachOX86_64(RuntimeDyld::MemoryManager &MM,
JITSymbolResolver &Resolver)
: RuntimeDyldMachOCRTPBase(MM, Resolver) {}
unsigned getMaxStubSize() const override { return 8; }
unsigned getStubAlignment() override { return 8; }
Expected<relocation_iterator>
processRelocationRef(unsigned SectionID, relocation_iterator RelI,
const ObjectFile &BaseObjT,
ObjSectionToIDMap &ObjSectionToID,
StubMap &Stubs) override {
const MachOObjectFile &Obj =
static_cast<const MachOObjectFile &>(BaseObjT);
MachO::any_relocation_info RelInfo =
Obj.getRelocation(RelI->getRawDataRefImpl());
uint32_t RelType = Obj.getAnyRelocationType(RelInfo);
if (RelType == MachO::X86_64_RELOC_SUBTRACTOR)
return processSubtractRelocation(SectionID, RelI, Obj, ObjSectionToID);
assert(!Obj.isRelocationScattered(RelInfo) &&
"Scattered relocations not supported on X86_64");
RelocationEntry RE(getRelocationEntry(SectionID, Obj, RelI));
RE.Addend = memcpyAddend(RE);
RelocationValueRef Value;
if (auto ValueOrErr = getRelocationValueRef(Obj, RelI, RE, ObjSectionToID))
Value = *ValueOrErr;
else
return ValueOrErr.takeError();
bool IsExtern = Obj.getPlainRelocationExternal(RelInfo);
if (!IsExtern && RE.IsPCRel)
makeValueAddendPCRel(Value, RelI, 1 << RE.Size);
switch (RelType) {
UNIMPLEMENTED_RELOC(MachO::X86_64_RELOC_TLV);
default:
if (RelType > MachO::X86_64_RELOC_TLV)
return make_error<RuntimeDyldError>(("MachO X86_64 relocation type " +
Twine(RelType) +
" is out of range").str());
break;
}
if (RE.RelType == MachO::X86_64_RELOC_GOT ||
RE.RelType == MachO::X86_64_RELOC_GOT_LOAD)
processGOTRelocation(RE, Value, Stubs);
else {
RE.Addend = Value.Offset;
if (Value.SymbolName)
addRelocationForSymbol(RE, Value.SymbolName);
else
addRelocationForSection(RE, Value.SectionID);
}
return ++RelI;
}
void resolveRelocation(const RelocationEntry &RE, uint64_t Value) override {
LLVM_DEBUG(dumpRelocationToResolve(RE, Value));
const SectionEntry &Section = Sections[RE.SectionID];
uint8_t *LocalAddress = Section.getAddressWithOffset(RE.Offset);
// If the relocation is PC-relative, the value to be encoded is the
// pointer difference.
if (RE.IsPCRel) {
// FIXME: It seems this value needs to be adjusted by 4 for an effective
// PC address. Is that expected? Only for branches, perhaps?
uint64_t FinalAddress = Section.getLoadAddressWithOffset(RE.Offset);
Value -= FinalAddress + 4;
}
switch (RE.RelType) {
default:
llvm_unreachable("Invalid relocation type!");
case MachO::X86_64_RELOC_SIGNED_1:
case MachO::X86_64_RELOC_SIGNED_2:
case MachO::X86_64_RELOC_SIGNED_4:
case MachO::X86_64_RELOC_SIGNED:
case MachO::X86_64_RELOC_UNSIGNED:
case MachO::X86_64_RELOC_BRANCH:
writeBytesUnaligned(Value + RE.Addend, LocalAddress, 1 << RE.Size);
break;
case MachO::X86_64_RELOC_SUBTRACTOR: {
uint64_t SectionABase = Sections[RE.Sections.SectionA].getLoadAddress();
uint64_t SectionBBase = Sections[RE.Sections.SectionB].getLoadAddress();
assert((Value == SectionABase || Value == SectionBBase) &&
"Unexpected SUBTRACTOR relocation value.");
Value = SectionABase - SectionBBase + RE.Addend;
writeBytesUnaligned(Value, LocalAddress, 1 << RE.Size);
break;
}
}
}
Error finalizeSection(const ObjectFile &Obj, unsigned SectionID,
const SectionRef &Section) {
return Error::success();
}
private:
void processGOTRelocation(const RelocationEntry &RE,
RelocationValueRef &Value, StubMap &Stubs) {
SectionEntry &Section = Sections[RE.SectionID];
assert(RE.IsPCRel);
assert(RE.Size == 2);
Value.Offset -= RE.Addend;
RuntimeDyldMachO::StubMap::const_iterator i = Stubs.find(Value);
uint8_t *Addr;
if (i != Stubs.end()) {
Addr = Section.getAddressWithOffset(i->second);
} else {
Stubs[Value] = Section.getStubOffset();
uint8_t *GOTEntry = Section.getAddressWithOffset(Section.getStubOffset());
RelocationEntry GOTRE(RE.SectionID, Section.getStubOffset(),
MachO::X86_64_RELOC_UNSIGNED, Value.Offset, false,
3);
if (Value.SymbolName)
addRelocationForSymbol(GOTRE, Value.SymbolName);
else
addRelocationForSection(GOTRE, Value.SectionID);
Section.advanceStubOffset(8);
Addr = GOTEntry;
}
RelocationEntry TargetRE(RE.SectionID, RE.Offset,
MachO::X86_64_RELOC_UNSIGNED, RE.Addend, true, 2);
resolveRelocation(TargetRE, (uint64_t)Addr);
}
Expected<relocation_iterator>
processSubtractRelocation(unsigned SectionID, relocation_iterator RelI,
const MachOObjectFile &BaseObj,
ObjSectionToIDMap &ObjSectionToID) {
const MachOObjectFile &Obj =
static_cast<const MachOObjectFile&>(BaseObj);
MachO::any_relocation_info RE =
Obj.getRelocation(RelI->getRawDataRefImpl());
unsigned Size = Obj.getAnyRelocationLength(RE);
uint64_t Offset = RelI->getOffset();
uint8_t *LocalAddress = Sections[SectionID].getAddressWithOffset(Offset);
unsigned NumBytes = 1 << Size;
int64_t Addend =
SignExtend64(readBytesUnaligned(LocalAddress, NumBytes), NumBytes * 8);
unsigned SectionBID = ~0U;
uint64_t SectionBOffset = 0;
MachO::any_relocation_info RelInfo =
Obj.getRelocation(RelI->getRawDataRefImpl());
bool AIsExternal = BaseObj.getPlainRelocationExternal(RelInfo);
if (AIsExternal) {
Expected<StringRef> SubtrahendNameOrErr = RelI->getSymbol()->getName();
if (!SubtrahendNameOrErr)
return SubtrahendNameOrErr.takeError();
auto SubtrahendI = GlobalSymbolTable.find(*SubtrahendNameOrErr);
SectionBID = SubtrahendI->second.getSectionID();
SectionBOffset = SubtrahendI->second.getOffset();
} else {
SectionRef SecB = Obj.getAnyRelocationSection(RelInfo);
bool IsCode = SecB.isText();
Expected<unsigned> SectionBIDOrErr =
findOrEmitSection(Obj, SecB, IsCode, ObjSectionToID);
if (!SectionBIDOrErr)
return SectionBIDOrErr.takeError();
SectionBID = *SectionBIDOrErr;
Addend += SecB.getAddress();
}
++RelI;
unsigned SectionAID = ~0U;
uint64_t SectionAOffset = 0;
RelInfo = Obj.getRelocation(RelI->getRawDataRefImpl());
bool BIsExternal = BaseObj.getPlainRelocationExternal(RelInfo);
if (BIsExternal) {
Expected<StringRef> MinuendNameOrErr = RelI->getSymbol()->getName();
if (!MinuendNameOrErr)
return MinuendNameOrErr.takeError();
auto MinuendI = GlobalSymbolTable.find(*MinuendNameOrErr);
SectionAID = MinuendI->second.getSectionID();
SectionAOffset = MinuendI->second.getOffset();
} else {
SectionRef SecA = Obj.getAnyRelocationSection(RelInfo);
bool IsCode = SecA.isText();
Expected<unsigned> SectionAIDOrErr =
findOrEmitSection(Obj, SecA, IsCode, ObjSectionToID);
if (!SectionAIDOrErr)
return SectionAIDOrErr.takeError();
SectionAID = *SectionAIDOrErr;
Addend -= SecA.getAddress();
}
RelocationEntry R(SectionID, Offset, MachO::X86_64_RELOC_SUBTRACTOR, (uint64_t)Addend,
SectionAID, SectionAOffset, SectionBID, SectionBOffset,
false, Size);
addRelocationForSection(R, SectionAID);
return ++RelI;
}
};
}
#undef DEBUG_TYPE
#endif
|