1 //===-- RuntimeDyldELF.cpp - 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 // Implementation of ELF support for the MC-JIT runtime dynamic linker.
10 //
11 //===----------------------------------------------------------------------===//
12
13 #include "RuntimeDyldELF.h"
14 #include "RuntimeDyldCheckerImpl.h"
15 #include "Targets/RuntimeDyldELFMips.h"
16 #include "llvm/ADT/STLExtras.h"
17 #include "llvm/ADT/StringRef.h"
18 #include "llvm/ADT/Triple.h"
19 #include "llvm/BinaryFormat/ELF.h"
20 #include "llvm/Object/ELFObjectFile.h"
21 #include "llvm/Object/ObjectFile.h"
22 #include "llvm/Support/Endian.h"
23 #include "llvm/Support/MemoryBuffer.h"
24
25 using namespace llvm;
26 using namespace llvm::object;
27 using namespace llvm::support::endian;
28
29 #define DEBUG_TYPE "dyld"
30
or32le(void * P,int32_t V)31 static void or32le(void *P, int32_t V) { write32le(P, read32le(P) | V); }
32
or32AArch64Imm(void * L,uint64_t Imm)33 static void or32AArch64Imm(void *L, uint64_t Imm) {
34 or32le(L, (Imm & 0xFFF) << 10);
35 }
36
write(bool isBE,void * P,T V)37 template <class T> static void write(bool isBE, void *P, T V) {
38 isBE ? write<T, support::big>(P, V) : write<T, support::little>(P, V);
39 }
40
write32AArch64Addr(void * L,uint64_t Imm)41 static void write32AArch64Addr(void *L, uint64_t Imm) {
42 uint32_t ImmLo = (Imm & 0x3) << 29;
43 uint32_t ImmHi = (Imm & 0x1FFFFC) << 3;
44 uint64_t Mask = (0x3 << 29) | (0x1FFFFC << 3);
45 write32le(L, (read32le(L) & ~Mask) | ImmLo | ImmHi);
46 }
47
48 // Return the bits [Start, End] from Val shifted Start bits.
49 // For instance, getBits(0xF0, 4, 8) returns 0xF.
getBits(uint64_t Val,int Start,int End)50 static uint64_t getBits(uint64_t Val, int Start, int End) {
51 uint64_t Mask = ((uint64_t)1 << (End + 1 - Start)) - 1;
52 return (Val >> Start) & Mask;
53 }
54
55 namespace {
56
57 template <class ELFT> class DyldELFObject : public ELFObjectFile<ELFT> {
58 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
59
60 typedef typename ELFT::uint addr_type;
61
62 DyldELFObject(ELFObjectFile<ELFT> &&Obj);
63
64 public:
65 static Expected<std::unique_ptr<DyldELFObject>>
66 create(MemoryBufferRef Wrapper);
67
68 void updateSectionAddress(const SectionRef &Sec, uint64_t Addr);
69
70 void updateSymbolAddress(const SymbolRef &SymRef, uint64_t Addr);
71
72 // Methods for type inquiry through isa, cast and dyn_cast
classof(const Binary * v)73 static bool classof(const Binary *v) {
74 return (isa<ELFObjectFile<ELFT>>(v) &&
75 classof(cast<ELFObjectFile<ELFT>>(v)));
76 }
classof(const ELFObjectFile<ELFT> * v)77 static bool classof(const ELFObjectFile<ELFT> *v) {
78 return v->isDyldType();
79 }
80 };
81
82
83
84 // The MemoryBuffer passed into this constructor is just a wrapper around the
85 // actual memory. Ultimately, the Binary parent class will take ownership of
86 // this MemoryBuffer object but not the underlying memory.
87 template <class ELFT>
DyldELFObject(ELFObjectFile<ELFT> && Obj)88 DyldELFObject<ELFT>::DyldELFObject(ELFObjectFile<ELFT> &&Obj)
89 : ELFObjectFile<ELFT>(std::move(Obj)) {
90 this->isDyldELFObject = true;
91 }
92
93 template <class ELFT>
94 Expected<std::unique_ptr<DyldELFObject<ELFT>>>
create(MemoryBufferRef Wrapper)95 DyldELFObject<ELFT>::create(MemoryBufferRef Wrapper) {
96 auto Obj = ELFObjectFile<ELFT>::create(Wrapper);
97 if (auto E = Obj.takeError())
98 return std::move(E);
99 std::unique_ptr<DyldELFObject<ELFT>> Ret(
100 new DyldELFObject<ELFT>(std::move(*Obj)));
101 return std::move(Ret);
102 }
103
104 template <class ELFT>
updateSectionAddress(const SectionRef & Sec,uint64_t Addr)105 void DyldELFObject<ELFT>::updateSectionAddress(const SectionRef &Sec,
106 uint64_t Addr) {
107 DataRefImpl ShdrRef = Sec.getRawDataRefImpl();
108 Elf_Shdr *shdr =
109 const_cast<Elf_Shdr *>(reinterpret_cast<const Elf_Shdr *>(ShdrRef.p));
110
111 // This assumes the address passed in matches the target address bitness
112 // The template-based type cast handles everything else.
113 shdr->sh_addr = static_cast<addr_type>(Addr);
114 }
115
116 template <class ELFT>
updateSymbolAddress(const SymbolRef & SymRef,uint64_t Addr)117 void DyldELFObject<ELFT>::updateSymbolAddress(const SymbolRef &SymRef,
118 uint64_t Addr) {
119
120 Elf_Sym *sym = const_cast<Elf_Sym *>(
121 ELFObjectFile<ELFT>::getSymbol(SymRef.getRawDataRefImpl()));
122
123 // This assumes the address passed in matches the target address bitness
124 // The template-based type cast handles everything else.
125 sym->st_value = static_cast<addr_type>(Addr);
126 }
127
128 class LoadedELFObjectInfo final
129 : public LoadedObjectInfoHelper<LoadedELFObjectInfo,
130 RuntimeDyld::LoadedObjectInfo> {
131 public:
LoadedELFObjectInfo(RuntimeDyldImpl & RTDyld,ObjSectionToIDMap ObjSecToIDMap)132 LoadedELFObjectInfo(RuntimeDyldImpl &RTDyld, ObjSectionToIDMap ObjSecToIDMap)
133 : LoadedObjectInfoHelper(RTDyld, std::move(ObjSecToIDMap)) {}
134
135 OwningBinary<ObjectFile>
136 getObjectForDebug(const ObjectFile &Obj) const override;
137 };
138
139 template <typename ELFT>
140 static Expected<std::unique_ptr<DyldELFObject<ELFT>>>
createRTDyldELFObject(MemoryBufferRef Buffer,const ObjectFile & SourceObject,const LoadedELFObjectInfo & L)141 createRTDyldELFObject(MemoryBufferRef Buffer, const ObjectFile &SourceObject,
142 const LoadedELFObjectInfo &L) {
143 typedef typename ELFT::Shdr Elf_Shdr;
144 typedef typename ELFT::uint addr_type;
145
146 Expected<std::unique_ptr<DyldELFObject<ELFT>>> ObjOrErr =
147 DyldELFObject<ELFT>::create(Buffer);
148 if (Error E = ObjOrErr.takeError())
149 return std::move(E);
150
151 std::unique_ptr<DyldELFObject<ELFT>> Obj = std::move(*ObjOrErr);
152
153 // Iterate over all sections in the object.
154 auto SI = SourceObject.section_begin();
155 for (const auto &Sec : Obj->sections()) {
156 Expected<StringRef> NameOrErr = Sec.getName();
157 if (!NameOrErr) {
158 consumeError(NameOrErr.takeError());
159 continue;
160 }
161
162 if (*NameOrErr != "") {
163 DataRefImpl ShdrRef = Sec.getRawDataRefImpl();
164 Elf_Shdr *shdr = const_cast<Elf_Shdr *>(
165 reinterpret_cast<const Elf_Shdr *>(ShdrRef.p));
166
167 if (uint64_t SecLoadAddr = L.getSectionLoadAddress(*SI)) {
168 // This assumes that the address passed in matches the target address
169 // bitness. The template-based type cast handles everything else.
170 shdr->sh_addr = static_cast<addr_type>(SecLoadAddr);
171 }
172 }
173 ++SI;
174 }
175
176 return std::move(Obj);
177 }
178
179 static OwningBinary<ObjectFile>
createELFDebugObject(const ObjectFile & Obj,const LoadedELFObjectInfo & L)180 createELFDebugObject(const ObjectFile &Obj, const LoadedELFObjectInfo &L) {
181 assert(Obj.isELF() && "Not an ELF object file.");
182
183 std::unique_ptr<MemoryBuffer> Buffer =
184 MemoryBuffer::getMemBufferCopy(Obj.getData(), Obj.getFileName());
185
186 Expected<std::unique_ptr<ObjectFile>> DebugObj(nullptr);
187 handleAllErrors(DebugObj.takeError());
188 if (Obj.getBytesInAddress() == 4 && Obj.isLittleEndian())
189 DebugObj =
190 createRTDyldELFObject<ELF32LE>(Buffer->getMemBufferRef(), Obj, L);
191 else if (Obj.getBytesInAddress() == 4 && !Obj.isLittleEndian())
192 DebugObj =
193 createRTDyldELFObject<ELF32BE>(Buffer->getMemBufferRef(), Obj, L);
194 else if (Obj.getBytesInAddress() == 8 && !Obj.isLittleEndian())
195 DebugObj =
196 createRTDyldELFObject<ELF64BE>(Buffer->getMemBufferRef(), Obj, L);
197 else if (Obj.getBytesInAddress() == 8 && Obj.isLittleEndian())
198 DebugObj =
199 createRTDyldELFObject<ELF64LE>(Buffer->getMemBufferRef(), Obj, L);
200 else
201 llvm_unreachable("Unexpected ELF format");
202
203 handleAllErrors(DebugObj.takeError());
204 return OwningBinary<ObjectFile>(std::move(*DebugObj), std::move(Buffer));
205 }
206
207 OwningBinary<ObjectFile>
getObjectForDebug(const ObjectFile & Obj) const208 LoadedELFObjectInfo::getObjectForDebug(const ObjectFile &Obj) const {
209 return createELFDebugObject(Obj, *this);
210 }
211
212 } // anonymous namespace
213
214 namespace llvm {
215
RuntimeDyldELF(RuntimeDyld::MemoryManager & MemMgr,JITSymbolResolver & Resolver)216 RuntimeDyldELF::RuntimeDyldELF(RuntimeDyld::MemoryManager &MemMgr,
217 JITSymbolResolver &Resolver)
218 : RuntimeDyldImpl(MemMgr, Resolver), GOTSectionID(0), CurrentGOTIndex(0) {}
~RuntimeDyldELF()219 RuntimeDyldELF::~RuntimeDyldELF() {}
220
registerEHFrames()221 void RuntimeDyldELF::registerEHFrames() {
222 for (int i = 0, e = UnregisteredEHFrameSections.size(); i != e; ++i) {
223 SID EHFrameSID = UnregisteredEHFrameSections[i];
224 uint8_t *EHFrameAddr = Sections[EHFrameSID].getAddress();
225 uint64_t EHFrameLoadAddr = Sections[EHFrameSID].getLoadAddress();
226 size_t EHFrameSize = Sections[EHFrameSID].getSize();
227 MemMgr.registerEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
228 }
229 UnregisteredEHFrameSections.clear();
230 }
231
232 std::unique_ptr<RuntimeDyldELF>
create(Triple::ArchType Arch,RuntimeDyld::MemoryManager & MemMgr,JITSymbolResolver & Resolver)233 llvm::RuntimeDyldELF::create(Triple::ArchType Arch,
234 RuntimeDyld::MemoryManager &MemMgr,
235 JITSymbolResolver &Resolver) {
236 switch (Arch) {
237 default:
238 return std::make_unique<RuntimeDyldELF>(MemMgr, Resolver);
239 case Triple::mips:
240 case Triple::mipsel:
241 case Triple::mips64:
242 case Triple::mips64el:
243 return std::make_unique<RuntimeDyldELFMips>(MemMgr, Resolver);
244 }
245 }
246
247 std::unique_ptr<RuntimeDyld::LoadedObjectInfo>
loadObject(const object::ObjectFile & O)248 RuntimeDyldELF::loadObject(const object::ObjectFile &O) {
249 if (auto ObjSectionToIDOrErr = loadObjectImpl(O))
250 return std::make_unique<LoadedELFObjectInfo>(*this, *ObjSectionToIDOrErr);
251 else {
252 HasError = true;
253 raw_string_ostream ErrStream(ErrorStr);
254 logAllUnhandledErrors(ObjSectionToIDOrErr.takeError(), ErrStream);
255 return nullptr;
256 }
257 }
258
resolveX86_64Relocation(const SectionEntry & Section,uint64_t Offset,uint64_t Value,uint32_t Type,int64_t Addend,uint64_t SymOffset)259 void RuntimeDyldELF::resolveX86_64Relocation(const SectionEntry &Section,
260 uint64_t Offset, uint64_t Value,
261 uint32_t Type, int64_t Addend,
262 uint64_t SymOffset) {
263 switch (Type) {
264 default:
265 report_fatal_error("Relocation type not implemented yet!");
266 break;
267 case ELF::R_X86_64_NONE:
268 break;
269 case ELF::R_X86_64_8: {
270 Value += Addend;
271 assert((int64_t)Value <= INT8_MAX && (int64_t)Value >= INT8_MIN);
272 uint8_t TruncatedAddr = (Value & 0xFF);
273 *Section.getAddressWithOffset(Offset) = TruncatedAddr;
274 LLVM_DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr) << " at "
275 << format("%p\n", Section.getAddressWithOffset(Offset)));
276 break;
277 }
278 case ELF::R_X86_64_16: {
279 Value += Addend;
280 assert((int64_t)Value <= INT16_MAX && (int64_t)Value >= INT16_MIN);
281 uint16_t TruncatedAddr = (Value & 0xFFFF);
282 support::ulittle16_t::ref(Section.getAddressWithOffset(Offset)) =
283 TruncatedAddr;
284 LLVM_DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr) << " at "
285 << format("%p\n", Section.getAddressWithOffset(Offset)));
286 break;
287 }
288 case ELF::R_X86_64_64: {
289 support::ulittle64_t::ref(Section.getAddressWithOffset(Offset)) =
290 Value + Addend;
291 LLVM_DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend)) << " at "
292 << format("%p\n", Section.getAddressWithOffset(Offset)));
293 break;
294 }
295 case ELF::R_X86_64_32:
296 case ELF::R_X86_64_32S: {
297 Value += Addend;
298 assert((Type == ELF::R_X86_64_32 && (Value <= UINT32_MAX)) ||
299 (Type == ELF::R_X86_64_32S &&
300 ((int64_t)Value <= INT32_MAX && (int64_t)Value >= INT32_MIN)));
301 uint32_t TruncatedAddr = (Value & 0xFFFFFFFF);
302 support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) =
303 TruncatedAddr;
304 LLVM_DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr) << " at "
305 << format("%p\n", Section.getAddressWithOffset(Offset)));
306 break;
307 }
308 case ELF::R_X86_64_PC8: {
309 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
310 int64_t RealOffset = Value + Addend - FinalAddress;
311 assert(isInt<8>(RealOffset));
312 int8_t TruncOffset = (RealOffset & 0xFF);
313 Section.getAddress()[Offset] = TruncOffset;
314 break;
315 }
316 case ELF::R_X86_64_PC32: {
317 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
318 int64_t RealOffset = Value + Addend - FinalAddress;
319 assert(isInt<32>(RealOffset));
320 int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
321 support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) =
322 TruncOffset;
323 break;
324 }
325 case ELF::R_X86_64_PC64: {
326 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
327 int64_t RealOffset = Value + Addend - FinalAddress;
328 support::ulittle64_t::ref(Section.getAddressWithOffset(Offset)) =
329 RealOffset;
330 LLVM_DEBUG(dbgs() << "Writing " << format("%p", RealOffset) << " at "
331 << format("%p\n", FinalAddress));
332 break;
333 }
334 case ELF::R_X86_64_GOTOFF64: {
335 // Compute Value - GOTBase.
336 uint64_t GOTBase = 0;
337 for (const auto &Section : Sections) {
338 if (Section.getName() == ".got") {
339 GOTBase = Section.getLoadAddressWithOffset(0);
340 break;
341 }
342 }
343 assert(GOTBase != 0 && "missing GOT");
344 int64_t GOTOffset = Value - GOTBase + Addend;
345 support::ulittle64_t::ref(Section.getAddressWithOffset(Offset)) = GOTOffset;
346 break;
347 }
348 }
349 }
350
resolveX86Relocation(const SectionEntry & Section,uint64_t Offset,uint32_t Value,uint32_t Type,int32_t Addend)351 void RuntimeDyldELF::resolveX86Relocation(const SectionEntry &Section,
352 uint64_t Offset, uint32_t Value,
353 uint32_t Type, int32_t Addend) {
354 switch (Type) {
355 case ELF::R_386_32: {
356 support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) =
357 Value + Addend;
358 break;
359 }
360 // Handle R_386_PLT32 like R_386_PC32 since it should be able to
361 // reach any 32 bit address.
362 case ELF::R_386_PLT32:
363 case ELF::R_386_PC32: {
364 uint32_t FinalAddress =
365 Section.getLoadAddressWithOffset(Offset) & 0xFFFFFFFF;
366 uint32_t RealOffset = Value + Addend - FinalAddress;
367 support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) =
368 RealOffset;
369 break;
370 }
371 default:
372 // There are other relocation types, but it appears these are the
373 // only ones currently used by the LLVM ELF object writer
374 report_fatal_error("Relocation type not implemented yet!");
375 break;
376 }
377 }
378
resolveAArch64Relocation(const SectionEntry & Section,uint64_t Offset,uint64_t Value,uint32_t Type,int64_t Addend)379 void RuntimeDyldELF::resolveAArch64Relocation(const SectionEntry &Section,
380 uint64_t Offset, uint64_t Value,
381 uint32_t Type, int64_t Addend) {
382 uint32_t *TargetPtr =
383 reinterpret_cast<uint32_t *>(Section.getAddressWithOffset(Offset));
384 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
385 // Data should use target endian. Code should always use little endian.
386 bool isBE = Arch == Triple::aarch64_be;
387
388 LLVM_DEBUG(dbgs() << "resolveAArch64Relocation, LocalAddress: 0x"
389 << format("%llx", Section.getAddressWithOffset(Offset))
390 << " FinalAddress: 0x" << format("%llx", FinalAddress)
391 << " Value: 0x" << format("%llx", Value) << " Type: 0x"
392 << format("%x", Type) << " Addend: 0x"
393 << format("%llx", Addend) << "\n");
394
395 switch (Type) {
396 default:
397 report_fatal_error("Relocation type not implemented yet!");
398 break;
399 case ELF::R_AARCH64_ABS16: {
400 uint64_t Result = Value + Addend;
401 assert(static_cast<int64_t>(Result) >= INT16_MIN && Result < UINT16_MAX);
402 write(isBE, TargetPtr, static_cast<uint16_t>(Result & 0xffffU));
403 break;
404 }
405 case ELF::R_AARCH64_ABS32: {
406 uint64_t Result = Value + Addend;
407 assert(static_cast<int64_t>(Result) >= INT32_MIN && Result < UINT32_MAX);
408 write(isBE, TargetPtr, static_cast<uint32_t>(Result & 0xffffffffU));
409 break;
410 }
411 case ELF::R_AARCH64_ABS64:
412 write(isBE, TargetPtr, Value + Addend);
413 break;
414 case ELF::R_AARCH64_PLT32: {
415 uint64_t Result = Value + Addend - FinalAddress;
416 assert(static_cast<int64_t>(Result) >= INT32_MIN &&
417 static_cast<int64_t>(Result) <= INT32_MAX);
418 write(isBE, TargetPtr, static_cast<uint32_t>(Result));
419 break;
420 }
421 case ELF::R_AARCH64_PREL32: {
422 uint64_t Result = Value + Addend - FinalAddress;
423 assert(static_cast<int64_t>(Result) >= INT32_MIN &&
424 static_cast<int64_t>(Result) <= UINT32_MAX);
425 write(isBE, TargetPtr, static_cast<uint32_t>(Result & 0xffffffffU));
426 break;
427 }
428 case ELF::R_AARCH64_PREL64:
429 write(isBE, TargetPtr, Value + Addend - FinalAddress);
430 break;
431 case ELF::R_AARCH64_CONDBR19: {
432 uint64_t BranchImm = Value + Addend - FinalAddress;
433
434 assert(isInt<21>(BranchImm));
435 *TargetPtr &= 0xff00001fU;
436 // Immediate:20:2 goes in bits 23:5 of Bcc, CBZ, CBNZ
437 or32le(TargetPtr, (BranchImm & 0x001FFFFC) << 3);
438 break;
439 }
440 case ELF::R_AARCH64_TSTBR14: {
441 uint64_t BranchImm = Value + Addend - FinalAddress;
442
443 assert(isInt<16>(BranchImm));
444
445 *TargetPtr &= 0xfff8001fU;
446 // Immediate:15:2 goes in bits 18:5 of TBZ, TBNZ
447 or32le(TargetPtr, (BranchImm & 0x0FFFFFFC) << 3);
448 break;
449 }
450 case ELF::R_AARCH64_CALL26: // fallthrough
451 case ELF::R_AARCH64_JUMP26: {
452 // Operation: S+A-P. Set Call or B immediate value to bits fff_fffc of the
453 // calculation.
454 uint64_t BranchImm = Value + Addend - FinalAddress;
455
456 // "Check that -2^27 <= result < 2^27".
457 assert(isInt<28>(BranchImm));
458 or32le(TargetPtr, (BranchImm & 0x0FFFFFFC) >> 2);
459 break;
460 }
461 case ELF::R_AARCH64_MOVW_UABS_G3:
462 or32le(TargetPtr, ((Value + Addend) & 0xFFFF000000000000) >> 43);
463 break;
464 case ELF::R_AARCH64_MOVW_UABS_G2_NC:
465 or32le(TargetPtr, ((Value + Addend) & 0xFFFF00000000) >> 27);
466 break;
467 case ELF::R_AARCH64_MOVW_UABS_G1_NC:
468 or32le(TargetPtr, ((Value + Addend) & 0xFFFF0000) >> 11);
469 break;
470 case ELF::R_AARCH64_MOVW_UABS_G0_NC:
471 or32le(TargetPtr, ((Value + Addend) & 0xFFFF) << 5);
472 break;
473 case ELF::R_AARCH64_ADR_PREL_PG_HI21: {
474 // Operation: Page(S+A) - Page(P)
475 uint64_t Result =
476 ((Value + Addend) & ~0xfffULL) - (FinalAddress & ~0xfffULL);
477
478 // Check that -2^32 <= X < 2^32
479 assert(isInt<33>(Result) && "overflow check failed for relocation");
480
481 // Immediate goes in bits 30:29 + 5:23 of ADRP instruction, taken
482 // from bits 32:12 of X.
483 write32AArch64Addr(TargetPtr, Result >> 12);
484 break;
485 }
486 case ELF::R_AARCH64_ADD_ABS_LO12_NC:
487 // Operation: S + A
488 // Immediate goes in bits 21:10 of LD/ST instruction, taken
489 // from bits 11:0 of X
490 or32AArch64Imm(TargetPtr, Value + Addend);
491 break;
492 case ELF::R_AARCH64_LDST8_ABS_LO12_NC:
493 // Operation: S + A
494 // Immediate goes in bits 21:10 of LD/ST instruction, taken
495 // from bits 11:0 of X
496 or32AArch64Imm(TargetPtr, getBits(Value + Addend, 0, 11));
497 break;
498 case ELF::R_AARCH64_LDST16_ABS_LO12_NC:
499 // Operation: S + A
500 // Immediate goes in bits 21:10 of LD/ST instruction, taken
501 // from bits 11:1 of X
502 or32AArch64Imm(TargetPtr, getBits(Value + Addend, 1, 11));
503 break;
504 case ELF::R_AARCH64_LDST32_ABS_LO12_NC:
505 // Operation: S + A
506 // Immediate goes in bits 21:10 of LD/ST instruction, taken
507 // from bits 11:2 of X
508 or32AArch64Imm(TargetPtr, getBits(Value + Addend, 2, 11));
509 break;
510 case ELF::R_AARCH64_LDST64_ABS_LO12_NC:
511 // Operation: S + A
512 // Immediate goes in bits 21:10 of LD/ST instruction, taken
513 // from bits 11:3 of X
514 or32AArch64Imm(TargetPtr, getBits(Value + Addend, 3, 11));
515 break;
516 case ELF::R_AARCH64_LDST128_ABS_LO12_NC:
517 // Operation: S + A
518 // Immediate goes in bits 21:10 of LD/ST instruction, taken
519 // from bits 11:4 of X
520 or32AArch64Imm(TargetPtr, getBits(Value + Addend, 4, 11));
521 break;
522 case ELF::R_AARCH64_LD_PREL_LO19: {
523 // Operation: S + A - P
524 uint64_t Result = Value + Addend - FinalAddress;
525
526 // "Check that -2^20 <= result < 2^20".
527 assert(isInt<21>(Result));
528
529 *TargetPtr &= 0xff00001fU;
530 // Immediate goes in bits 23:5 of LD imm instruction, taken
531 // from bits 20:2 of X
532 *TargetPtr |= ((Result & 0xffc) << (5 - 2));
533 break;
534 }
535 case ELF::R_AARCH64_ADR_PREL_LO21: {
536 // Operation: S + A - P
537 uint64_t Result = Value + Addend - FinalAddress;
538
539 // "Check that -2^20 <= result < 2^20".
540 assert(isInt<21>(Result));
541
542 *TargetPtr &= 0x9f00001fU;
543 // Immediate goes in bits 23:5, 30:29 of ADR imm instruction, taken
544 // from bits 20:0 of X
545 *TargetPtr |= ((Result & 0xffc) << (5 - 2));
546 *TargetPtr |= (Result & 0x3) << 29;
547 break;
548 }
549 }
550 }
551
resolveARMRelocation(const SectionEntry & Section,uint64_t Offset,uint32_t Value,uint32_t Type,int32_t Addend)552 void RuntimeDyldELF::resolveARMRelocation(const SectionEntry &Section,
553 uint64_t Offset, uint32_t Value,
554 uint32_t Type, int32_t Addend) {
555 // TODO: Add Thumb relocations.
556 uint32_t *TargetPtr =
557 reinterpret_cast<uint32_t *>(Section.getAddressWithOffset(Offset));
558 uint32_t FinalAddress = Section.getLoadAddressWithOffset(Offset) & 0xFFFFFFFF;
559 Value += Addend;
560
561 LLVM_DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: "
562 << Section.getAddressWithOffset(Offset)
563 << " FinalAddress: " << format("%p", FinalAddress)
564 << " Value: " << format("%x", Value)
565 << " Type: " << format("%x", Type)
566 << " Addend: " << format("%x", Addend) << "\n");
567
568 switch (Type) {
569 default:
570 llvm_unreachable("Not implemented relocation type!");
571
572 case ELF::R_ARM_NONE:
573 break;
574 // Write a 31bit signed offset
575 case ELF::R_ARM_PREL31:
576 support::ulittle32_t::ref{TargetPtr} =
577 (support::ulittle32_t::ref{TargetPtr} & 0x80000000) |
578 ((Value - FinalAddress) & ~0x80000000);
579 break;
580 case ELF::R_ARM_TARGET1:
581 case ELF::R_ARM_ABS32:
582 support::ulittle32_t::ref{TargetPtr} = Value;
583 break;
584 // Write first 16 bit of 32 bit value to the mov instruction.
585 // Last 4 bit should be shifted.
586 case ELF::R_ARM_MOVW_ABS_NC:
587 case ELF::R_ARM_MOVT_ABS:
588 if (Type == ELF::R_ARM_MOVW_ABS_NC)
589 Value = Value & 0xFFFF;
590 else if (Type == ELF::R_ARM_MOVT_ABS)
591 Value = (Value >> 16) & 0xFFFF;
592 support::ulittle32_t::ref{TargetPtr} =
593 (support::ulittle32_t::ref{TargetPtr} & ~0x000F0FFF) | (Value & 0xFFF) |
594 (((Value >> 12) & 0xF) << 16);
595 break;
596 // Write 24 bit relative value to the branch instruction.
597 case ELF::R_ARM_PC24: // Fall through.
598 case ELF::R_ARM_CALL: // Fall through.
599 case ELF::R_ARM_JUMP24:
600 int32_t RelValue = static_cast<int32_t>(Value - FinalAddress - 8);
601 RelValue = (RelValue & 0x03FFFFFC) >> 2;
602 assert((support::ulittle32_t::ref{TargetPtr} & 0xFFFFFF) == 0xFFFFFE);
603 support::ulittle32_t::ref{TargetPtr} =
604 (support::ulittle32_t::ref{TargetPtr} & 0xFF000000) | RelValue;
605 break;
606 }
607 }
608
setMipsABI(const ObjectFile & Obj)609 void RuntimeDyldELF::setMipsABI(const ObjectFile &Obj) {
610 if (Arch == Triple::UnknownArch ||
611 !StringRef(Triple::getArchTypePrefix(Arch)).equals("mips")) {
612 IsMipsO32ABI = false;
613 IsMipsN32ABI = false;
614 IsMipsN64ABI = false;
615 return;
616 }
617 if (auto *E = dyn_cast<ELFObjectFileBase>(&Obj)) {
618 unsigned AbiVariant = E->getPlatformFlags();
619 IsMipsO32ABI = AbiVariant & ELF::EF_MIPS_ABI_O32;
620 IsMipsN32ABI = AbiVariant & ELF::EF_MIPS_ABI2;
621 }
622 IsMipsN64ABI = Obj.getFileFormatName().equals("elf64-mips");
623 }
624
625 // Return the .TOC. section and offset.
findPPC64TOCSection(const ELFObjectFileBase & Obj,ObjSectionToIDMap & LocalSections,RelocationValueRef & Rel)626 Error RuntimeDyldELF::findPPC64TOCSection(const ELFObjectFileBase &Obj,
627 ObjSectionToIDMap &LocalSections,
628 RelocationValueRef &Rel) {
629 // Set a default SectionID in case we do not find a TOC section below.
630 // This may happen for references to TOC base base (sym@toc, .odp
631 // relocation) without a .toc directive. In this case just use the
632 // first section (which is usually the .odp) since the code won't
633 // reference the .toc base directly.
634 Rel.SymbolName = nullptr;
635 Rel.SectionID = 0;
636
637 // The TOC consists of sections .got, .toc, .tocbss, .plt in that
638 // order. The TOC starts where the first of these sections starts.
639 for (auto &Section : Obj.sections()) {
640 Expected<StringRef> NameOrErr = Section.getName();
641 if (!NameOrErr)
642 return NameOrErr.takeError();
643 StringRef SectionName = *NameOrErr;
644
645 if (SectionName == ".got"
646 || SectionName == ".toc"
647 || SectionName == ".tocbss"
648 || SectionName == ".plt") {
649 if (auto SectionIDOrErr =
650 findOrEmitSection(Obj, Section, false, LocalSections))
651 Rel.SectionID = *SectionIDOrErr;
652 else
653 return SectionIDOrErr.takeError();
654 break;
655 }
656 }
657
658 // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000
659 // thus permitting a full 64 Kbytes segment.
660 Rel.Addend = 0x8000;
661
662 return Error::success();
663 }
664
665 // Returns the sections and offset associated with the ODP entry referenced
666 // by Symbol.
findOPDEntrySection(const ELFObjectFileBase & Obj,ObjSectionToIDMap & LocalSections,RelocationValueRef & Rel)667 Error RuntimeDyldELF::findOPDEntrySection(const ELFObjectFileBase &Obj,
668 ObjSectionToIDMap &LocalSections,
669 RelocationValueRef &Rel) {
670 // Get the ELF symbol value (st_value) to compare with Relocation offset in
671 // .opd entries
672 for (section_iterator si = Obj.section_begin(), se = Obj.section_end();
673 si != se; ++si) {
674
675 Expected<section_iterator> RelSecOrErr = si->getRelocatedSection();
676 if (!RelSecOrErr)
677 report_fatal_error(toString(RelSecOrErr.takeError()));
678
679 section_iterator RelSecI = *RelSecOrErr;
680 if (RelSecI == Obj.section_end())
681 continue;
682
683 Expected<StringRef> NameOrErr = RelSecI->getName();
684 if (!NameOrErr)
685 return NameOrErr.takeError();
686 StringRef RelSectionName = *NameOrErr;
687
688 if (RelSectionName != ".opd")
689 continue;
690
691 for (elf_relocation_iterator i = si->relocation_begin(),
692 e = si->relocation_end();
693 i != e;) {
694 // The R_PPC64_ADDR64 relocation indicates the first field
695 // of a .opd entry
696 uint64_t TypeFunc = i->getType();
697 if (TypeFunc != ELF::R_PPC64_ADDR64) {
698 ++i;
699 continue;
700 }
701
702 uint64_t TargetSymbolOffset = i->getOffset();
703 symbol_iterator TargetSymbol = i->getSymbol();
704 int64_t Addend;
705 if (auto AddendOrErr = i->getAddend())
706 Addend = *AddendOrErr;
707 else
708 return AddendOrErr.takeError();
709
710 ++i;
711 if (i == e)
712 break;
713
714 // Just check if following relocation is a R_PPC64_TOC
715 uint64_t TypeTOC = i->getType();
716 if (TypeTOC != ELF::R_PPC64_TOC)
717 continue;
718
719 // Finally compares the Symbol value and the target symbol offset
720 // to check if this .opd entry refers to the symbol the relocation
721 // points to.
722 if (Rel.Addend != (int64_t)TargetSymbolOffset)
723 continue;
724
725 section_iterator TSI = Obj.section_end();
726 if (auto TSIOrErr = TargetSymbol->getSection())
727 TSI = *TSIOrErr;
728 else
729 return TSIOrErr.takeError();
730 assert(TSI != Obj.section_end() && "TSI should refer to a valid section");
731
732 bool IsCode = TSI->isText();
733 if (auto SectionIDOrErr = findOrEmitSection(Obj, *TSI, IsCode,
734 LocalSections))
735 Rel.SectionID = *SectionIDOrErr;
736 else
737 return SectionIDOrErr.takeError();
738 Rel.Addend = (intptr_t)Addend;
739 return Error::success();
740 }
741 }
742 llvm_unreachable("Attempting to get address of ODP entry!");
743 }
744
745 // Relocation masks following the #lo(value), #hi(value), #ha(value),
746 // #higher(value), #highera(value), #highest(value), and #highesta(value)
747 // macros defined in section 4.5.1. Relocation Types of the PPC-elf64abi
748 // document.
749
applyPPClo(uint64_t value)750 static inline uint16_t applyPPClo(uint64_t value) { return value & 0xffff; }
751
applyPPChi(uint64_t value)752 static inline uint16_t applyPPChi(uint64_t value) {
753 return (value >> 16) & 0xffff;
754 }
755
applyPPCha(uint64_t value)756 static inline uint16_t applyPPCha (uint64_t value) {
757 return ((value + 0x8000) >> 16) & 0xffff;
758 }
759
applyPPChigher(uint64_t value)760 static inline uint16_t applyPPChigher(uint64_t value) {
761 return (value >> 32) & 0xffff;
762 }
763
applyPPChighera(uint64_t value)764 static inline uint16_t applyPPChighera (uint64_t value) {
765 return ((value + 0x8000) >> 32) & 0xffff;
766 }
767
applyPPChighest(uint64_t value)768 static inline uint16_t applyPPChighest(uint64_t value) {
769 return (value >> 48) & 0xffff;
770 }
771
applyPPChighesta(uint64_t value)772 static inline uint16_t applyPPChighesta (uint64_t value) {
773 return ((value + 0x8000) >> 48) & 0xffff;
774 }
775
resolvePPC32Relocation(const SectionEntry & Section,uint64_t Offset,uint64_t Value,uint32_t Type,int64_t Addend)776 void RuntimeDyldELF::resolvePPC32Relocation(const SectionEntry &Section,
777 uint64_t Offset, uint64_t Value,
778 uint32_t Type, int64_t Addend) {
779 uint8_t *LocalAddress = Section.getAddressWithOffset(Offset);
780 switch (Type) {
781 default:
782 report_fatal_error("Relocation type not implemented yet!");
783 break;
784 case ELF::R_PPC_ADDR16_LO:
785 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
786 break;
787 case ELF::R_PPC_ADDR16_HI:
788 writeInt16BE(LocalAddress, applyPPChi(Value + Addend));
789 break;
790 case ELF::R_PPC_ADDR16_HA:
791 writeInt16BE(LocalAddress, applyPPCha(Value + Addend));
792 break;
793 }
794 }
795
resolvePPC64Relocation(const SectionEntry & Section,uint64_t Offset,uint64_t Value,uint32_t Type,int64_t Addend)796 void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section,
797 uint64_t Offset, uint64_t Value,
798 uint32_t Type, int64_t Addend) {
799 uint8_t *LocalAddress = Section.getAddressWithOffset(Offset);
800 switch (Type) {
801 default:
802 report_fatal_error("Relocation type not implemented yet!");
803 break;
804 case ELF::R_PPC64_ADDR16:
805 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
806 break;
807 case ELF::R_PPC64_ADDR16_DS:
808 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
809 break;
810 case ELF::R_PPC64_ADDR16_LO:
811 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
812 break;
813 case ELF::R_PPC64_ADDR16_LO_DS:
814 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
815 break;
816 case ELF::R_PPC64_ADDR16_HI:
817 case ELF::R_PPC64_ADDR16_HIGH:
818 writeInt16BE(LocalAddress, applyPPChi(Value + Addend));
819 break;
820 case ELF::R_PPC64_ADDR16_HA:
821 case ELF::R_PPC64_ADDR16_HIGHA:
822 writeInt16BE(LocalAddress, applyPPCha(Value + Addend));
823 break;
824 case ELF::R_PPC64_ADDR16_HIGHER:
825 writeInt16BE(LocalAddress, applyPPChigher(Value + Addend));
826 break;
827 case ELF::R_PPC64_ADDR16_HIGHERA:
828 writeInt16BE(LocalAddress, applyPPChighera(Value + Addend));
829 break;
830 case ELF::R_PPC64_ADDR16_HIGHEST:
831 writeInt16BE(LocalAddress, applyPPChighest(Value + Addend));
832 break;
833 case ELF::R_PPC64_ADDR16_HIGHESTA:
834 writeInt16BE(LocalAddress, applyPPChighesta(Value + Addend));
835 break;
836 case ELF::R_PPC64_ADDR14: {
837 assert(((Value + Addend) & 3) == 0);
838 // Preserve the AA/LK bits in the branch instruction
839 uint8_t aalk = *(LocalAddress + 3);
840 writeInt16BE(LocalAddress + 2, (aalk & 3) | ((Value + Addend) & 0xfffc));
841 } break;
842 case ELF::R_PPC64_REL16_LO: {
843 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
844 uint64_t Delta = Value - FinalAddress + Addend;
845 writeInt16BE(LocalAddress, applyPPClo(Delta));
846 } break;
847 case ELF::R_PPC64_REL16_HI: {
848 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
849 uint64_t Delta = Value - FinalAddress + Addend;
850 writeInt16BE(LocalAddress, applyPPChi(Delta));
851 } break;
852 case ELF::R_PPC64_REL16_HA: {
853 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
854 uint64_t Delta = Value - FinalAddress + Addend;
855 writeInt16BE(LocalAddress, applyPPCha(Delta));
856 } break;
857 case ELF::R_PPC64_ADDR32: {
858 int64_t Result = static_cast<int64_t>(Value + Addend);
859 if (SignExtend64<32>(Result) != Result)
860 llvm_unreachable("Relocation R_PPC64_ADDR32 overflow");
861 writeInt32BE(LocalAddress, Result);
862 } break;
863 case ELF::R_PPC64_REL24: {
864 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
865 int64_t delta = static_cast<int64_t>(Value - FinalAddress + Addend);
866 if (SignExtend64<26>(delta) != delta)
867 llvm_unreachable("Relocation R_PPC64_REL24 overflow");
868 // We preserve bits other than LI field, i.e. PO and AA/LK fields.
869 uint32_t Inst = readBytesUnaligned(LocalAddress, 4);
870 writeInt32BE(LocalAddress, (Inst & 0xFC000003) | (delta & 0x03FFFFFC));
871 } break;
872 case ELF::R_PPC64_REL32: {
873 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
874 int64_t delta = static_cast<int64_t>(Value - FinalAddress + Addend);
875 if (SignExtend64<32>(delta) != delta)
876 llvm_unreachable("Relocation R_PPC64_REL32 overflow");
877 writeInt32BE(LocalAddress, delta);
878 } break;
879 case ELF::R_PPC64_REL64: {
880 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
881 uint64_t Delta = Value - FinalAddress + Addend;
882 writeInt64BE(LocalAddress, Delta);
883 } break;
884 case ELF::R_PPC64_ADDR64:
885 writeInt64BE(LocalAddress, Value + Addend);
886 break;
887 }
888 }
889
resolveSystemZRelocation(const SectionEntry & Section,uint64_t Offset,uint64_t Value,uint32_t Type,int64_t Addend)890 void RuntimeDyldELF::resolveSystemZRelocation(const SectionEntry &Section,
891 uint64_t Offset, uint64_t Value,
892 uint32_t Type, int64_t Addend) {
893 uint8_t *LocalAddress = Section.getAddressWithOffset(Offset);
894 switch (Type) {
895 default:
896 report_fatal_error("Relocation type not implemented yet!");
897 break;
898 case ELF::R_390_PC16DBL:
899 case ELF::R_390_PLT16DBL: {
900 int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset);
901 assert(int16_t(Delta / 2) * 2 == Delta && "R_390_PC16DBL overflow");
902 writeInt16BE(LocalAddress, Delta / 2);
903 break;
904 }
905 case ELF::R_390_PC32DBL:
906 case ELF::R_390_PLT32DBL: {
907 int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset);
908 assert(int32_t(Delta / 2) * 2 == Delta && "R_390_PC32DBL overflow");
909 writeInt32BE(LocalAddress, Delta / 2);
910 break;
911 }
912 case ELF::R_390_PC16: {
913 int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset);
914 assert(int16_t(Delta) == Delta && "R_390_PC16 overflow");
915 writeInt16BE(LocalAddress, Delta);
916 break;
917 }
918 case ELF::R_390_PC32: {
919 int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset);
920 assert(int32_t(Delta) == Delta && "R_390_PC32 overflow");
921 writeInt32BE(LocalAddress, Delta);
922 break;
923 }
924 case ELF::R_390_PC64: {
925 int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset);
926 writeInt64BE(LocalAddress, Delta);
927 break;
928 }
929 case ELF::R_390_8:
930 *LocalAddress = (uint8_t)(Value + Addend);
931 break;
932 case ELF::R_390_16:
933 writeInt16BE(LocalAddress, Value + Addend);
934 break;
935 case ELF::R_390_32:
936 writeInt32BE(LocalAddress, Value + Addend);
937 break;
938 case ELF::R_390_64:
939 writeInt64BE(LocalAddress, Value + Addend);
940 break;
941 }
942 }
943
resolveBPFRelocation(const SectionEntry & Section,uint64_t Offset,uint64_t Value,uint32_t Type,int64_t Addend)944 void RuntimeDyldELF::resolveBPFRelocation(const SectionEntry &Section,
945 uint64_t Offset, uint64_t Value,
946 uint32_t Type, int64_t Addend) {
947 bool isBE = Arch == Triple::bpfeb;
948
949 switch (Type) {
950 default:
951 report_fatal_error("Relocation type not implemented yet!");
952 break;
953 case ELF::R_BPF_NONE:
954 break;
955 case ELF::R_BPF_64_64: {
956 write(isBE, Section.getAddressWithOffset(Offset), Value + Addend);
957 LLVM_DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend)) << " at "
958 << format("%p\n", Section.getAddressWithOffset(Offset)));
959 break;
960 }
961 case ELF::R_BPF_64_32: {
962 Value += Addend;
963 assert(Value <= UINT32_MAX);
964 write(isBE, Section.getAddressWithOffset(Offset), static_cast<uint32_t>(Value));
965 LLVM_DEBUG(dbgs() << "Writing " << format("%p", Value) << " at "
966 << format("%p\n", Section.getAddressWithOffset(Offset)));
967 break;
968 }
969 }
970 }
971
972 // The target location for the relocation is described by RE.SectionID and
973 // RE.Offset. RE.SectionID can be used to find the SectionEntry. Each
974 // SectionEntry has three members describing its location.
975 // SectionEntry::Address is the address at which the section has been loaded
976 // into memory in the current (host) process. SectionEntry::LoadAddress is the
977 // address that the section will have in the target process.
978 // SectionEntry::ObjAddress is the address of the bits for this section in the
979 // original emitted object image (also in the current address space).
980 //
981 // Relocations will be applied as if the section were loaded at
982 // SectionEntry::LoadAddress, but they will be applied at an address based
983 // on SectionEntry::Address. SectionEntry::ObjAddress will be used to refer to
984 // Target memory contents if they are required for value calculations.
985 //
986 // The Value parameter here is the load address of the symbol for the
987 // relocation to be applied. For relocations which refer to symbols in the
988 // current object Value will be the LoadAddress of the section in which
989 // the symbol resides (RE.Addend provides additional information about the
990 // symbol location). For external symbols, Value will be the address of the
991 // symbol in the target address space.
resolveRelocation(const RelocationEntry & RE,uint64_t Value)992 void RuntimeDyldELF::resolveRelocation(const RelocationEntry &RE,
993 uint64_t Value) {
994 const SectionEntry &Section = Sections[RE.SectionID];
995 return resolveRelocation(Section, RE.Offset, Value, RE.RelType, RE.Addend,
996 RE.SymOffset, RE.SectionID);
997 }
998
resolveRelocation(const SectionEntry & Section,uint64_t Offset,uint64_t Value,uint32_t Type,int64_t Addend,uint64_t SymOffset,SID SectionID)999 void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section,
1000 uint64_t Offset, uint64_t Value,
1001 uint32_t Type, int64_t Addend,
1002 uint64_t SymOffset, SID SectionID) {
1003 switch (Arch) {
1004 case Triple::x86_64:
1005 resolveX86_64Relocation(Section, Offset, Value, Type, Addend, SymOffset);
1006 break;
1007 case Triple::x86:
1008 resolveX86Relocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
1009 (uint32_t)(Addend & 0xffffffffL));
1010 break;
1011 case Triple::aarch64:
1012 case Triple::aarch64_be:
1013 resolveAArch64Relocation(Section, Offset, Value, Type, Addend);
1014 break;
1015 case Triple::arm: // Fall through.
1016 case Triple::armeb:
1017 case Triple::thumb:
1018 case Triple::thumbeb:
1019 resolveARMRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
1020 (uint32_t)(Addend & 0xffffffffL));
1021 break;
1022 case Triple::ppc: // Fall through.
1023 case Triple::ppcle:
1024 resolvePPC32Relocation(Section, Offset, Value, Type, Addend);
1025 break;
1026 case Triple::ppc64: // Fall through.
1027 case Triple::ppc64le:
1028 resolvePPC64Relocation(Section, Offset, Value, Type, Addend);
1029 break;
1030 case Triple::systemz:
1031 resolveSystemZRelocation(Section, Offset, Value, Type, Addend);
1032 break;
1033 case Triple::bpfel:
1034 case Triple::bpfeb:
1035 resolveBPFRelocation(Section, Offset, Value, Type, Addend);
1036 break;
1037 default:
1038 llvm_unreachable("Unsupported CPU type!");
1039 }
1040 }
1041
computePlaceholderAddress(unsigned SectionID,uint64_t Offset) const1042 void *RuntimeDyldELF::computePlaceholderAddress(unsigned SectionID, uint64_t Offset) const {
1043 return (void *)(Sections[SectionID].getObjAddress() + Offset);
1044 }
1045
processSimpleRelocation(unsigned SectionID,uint64_t Offset,unsigned RelType,RelocationValueRef Value)1046 void RuntimeDyldELF::processSimpleRelocation(unsigned SectionID, uint64_t Offset, unsigned RelType, RelocationValueRef Value) {
1047 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend, Value.Offset);
1048 if (Value.SymbolName)
1049 addRelocationForSymbol(RE, Value.SymbolName);
1050 else
1051 addRelocationForSection(RE, Value.SectionID);
1052 }
1053
getMatchingLoRelocation(uint32_t RelType,bool IsLocal) const1054 uint32_t RuntimeDyldELF::getMatchingLoRelocation(uint32_t RelType,
1055 bool IsLocal) const {
1056 switch (RelType) {
1057 case ELF::R_MICROMIPS_GOT16:
1058 if (IsLocal)
1059 return ELF::R_MICROMIPS_LO16;
1060 break;
1061 case ELF::R_MICROMIPS_HI16:
1062 return ELF::R_MICROMIPS_LO16;
1063 case ELF::R_MIPS_GOT16:
1064 if (IsLocal)
1065 return ELF::R_MIPS_LO16;
1066 break;
1067 case ELF::R_MIPS_HI16:
1068 return ELF::R_MIPS_LO16;
1069 case ELF::R_MIPS_PCHI16:
1070 return ELF::R_MIPS_PCLO16;
1071 default:
1072 break;
1073 }
1074 return ELF::R_MIPS_NONE;
1075 }
1076
1077 // Sometimes we don't need to create thunk for a branch.
1078 // This typically happens when branch target is located
1079 // in the same object file. In such case target is either
1080 // a weak symbol or symbol in a different executable section.
1081 // This function checks if branch target is located in the
1082 // same object file and if distance between source and target
1083 // fits R_AARCH64_CALL26 relocation. If both conditions are
1084 // met, it emits direct jump to the target and returns true.
1085 // Otherwise false is returned and thunk is created.
resolveAArch64ShortBranch(unsigned SectionID,relocation_iterator RelI,const RelocationValueRef & Value)1086 bool RuntimeDyldELF::resolveAArch64ShortBranch(
1087 unsigned SectionID, relocation_iterator RelI,
1088 const RelocationValueRef &Value) {
1089 uint64_t Address;
1090 if (Value.SymbolName) {
1091 auto Loc = GlobalSymbolTable.find(Value.SymbolName);
1092
1093 // Don't create direct branch for external symbols.
1094 if (Loc == GlobalSymbolTable.end())
1095 return false;
1096
1097 const auto &SymInfo = Loc->second;
1098 Address =
1099 uint64_t(Sections[SymInfo.getSectionID()].getLoadAddressWithOffset(
1100 SymInfo.getOffset()));
1101 } else {
1102 Address = uint64_t(Sections[Value.SectionID].getLoadAddress());
1103 }
1104 uint64_t Offset = RelI->getOffset();
1105 uint64_t SourceAddress = Sections[SectionID].getLoadAddressWithOffset(Offset);
1106
1107 // R_AARCH64_CALL26 requires immediate to be in range -2^27 <= imm < 2^27
1108 // If distance between source and target is out of range then we should
1109 // create thunk.
1110 if (!isInt<28>(Address + Value.Addend - SourceAddress))
1111 return false;
1112
1113 resolveRelocation(Sections[SectionID], Offset, Address, RelI->getType(),
1114 Value.Addend);
1115
1116 return true;
1117 }
1118
resolveAArch64Branch(unsigned SectionID,const RelocationValueRef & Value,relocation_iterator RelI,StubMap & Stubs)1119 void RuntimeDyldELF::resolveAArch64Branch(unsigned SectionID,
1120 const RelocationValueRef &Value,
1121 relocation_iterator RelI,
1122 StubMap &Stubs) {
1123
1124 LLVM_DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation.");
1125 SectionEntry &Section = Sections[SectionID];
1126
1127 uint64_t Offset = RelI->getOffset();
1128 unsigned RelType = RelI->getType();
1129 // Look for an existing stub.
1130 StubMap::const_iterator i = Stubs.find(Value);
1131 if (i != Stubs.end()) {
1132 resolveRelocation(Section, Offset,
1133 (uint64_t)Section.getAddressWithOffset(i->second),
1134 RelType, 0);
1135 LLVM_DEBUG(dbgs() << " Stub function found\n");
1136 } else if (!resolveAArch64ShortBranch(SectionID, RelI, Value)) {
1137 // Create a new stub function.
1138 LLVM_DEBUG(dbgs() << " Create a new stub function\n");
1139 Stubs[Value] = Section.getStubOffset();
1140 uint8_t *StubTargetAddr = createStubFunction(
1141 Section.getAddressWithOffset(Section.getStubOffset()));
1142
1143 RelocationEntry REmovz_g3(SectionID, StubTargetAddr - Section.getAddress(),
1144 ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend);
1145 RelocationEntry REmovk_g2(SectionID,
1146 StubTargetAddr - Section.getAddress() + 4,
1147 ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend);
1148 RelocationEntry REmovk_g1(SectionID,
1149 StubTargetAddr - Section.getAddress() + 8,
1150 ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend);
1151 RelocationEntry REmovk_g0(SectionID,
1152 StubTargetAddr - Section.getAddress() + 12,
1153 ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend);
1154
1155 if (Value.SymbolName) {
1156 addRelocationForSymbol(REmovz_g3, Value.SymbolName);
1157 addRelocationForSymbol(REmovk_g2, Value.SymbolName);
1158 addRelocationForSymbol(REmovk_g1, Value.SymbolName);
1159 addRelocationForSymbol(REmovk_g0, Value.SymbolName);
1160 } else {
1161 addRelocationForSection(REmovz_g3, Value.SectionID);
1162 addRelocationForSection(REmovk_g2, Value.SectionID);
1163 addRelocationForSection(REmovk_g1, Value.SectionID);
1164 addRelocationForSection(REmovk_g0, Value.SectionID);
1165 }
1166 resolveRelocation(Section, Offset,
1167 reinterpret_cast<uint64_t>(Section.getAddressWithOffset(
1168 Section.getStubOffset())),
1169 RelType, 0);
1170 Section.advanceStubOffset(getMaxStubSize());
1171 }
1172 }
1173
1174 Expected<relocation_iterator>
processRelocationRef(unsigned SectionID,relocation_iterator RelI,const ObjectFile & O,ObjSectionToIDMap & ObjSectionToID,StubMap & Stubs)1175 RuntimeDyldELF::processRelocationRef(
1176 unsigned SectionID, relocation_iterator RelI, const ObjectFile &O,
1177 ObjSectionToIDMap &ObjSectionToID, StubMap &Stubs) {
1178 const auto &Obj = cast<ELFObjectFileBase>(O);
1179 uint64_t RelType = RelI->getType();
1180 int64_t Addend = 0;
1181 if (Expected<int64_t> AddendOrErr = ELFRelocationRef(*RelI).getAddend())
1182 Addend = *AddendOrErr;
1183 else
1184 consumeError(AddendOrErr.takeError());
1185 elf_symbol_iterator Symbol = RelI->getSymbol();
1186
1187 // Obtain the symbol name which is referenced in the relocation
1188 StringRef TargetName;
1189 if (Symbol != Obj.symbol_end()) {
1190 if (auto TargetNameOrErr = Symbol->getName())
1191 TargetName = *TargetNameOrErr;
1192 else
1193 return TargetNameOrErr.takeError();
1194 }
1195 LLVM_DEBUG(dbgs() << "\t\tRelType: " << RelType << " Addend: " << Addend
1196 << " TargetName: " << TargetName << "\n");
1197 RelocationValueRef Value;
1198 // First search for the symbol in the local symbol table
1199 SymbolRef::Type SymType = SymbolRef::ST_Unknown;
1200
1201 // Search for the symbol in the global symbol table
1202 RTDyldSymbolTable::const_iterator gsi = GlobalSymbolTable.end();
1203 if (Symbol != Obj.symbol_end()) {
1204 gsi = GlobalSymbolTable.find(TargetName.data());
1205 Expected<SymbolRef::Type> SymTypeOrErr = Symbol->getType();
1206 if (!SymTypeOrErr) {
1207 std::string Buf;
1208 raw_string_ostream OS(Buf);
1209 logAllUnhandledErrors(SymTypeOrErr.takeError(), OS);
1210 OS.flush();
1211 report_fatal_error(Buf);
1212 }
1213 SymType = *SymTypeOrErr;
1214 }
1215 if (gsi != GlobalSymbolTable.end()) {
1216 const auto &SymInfo = gsi->second;
1217 Value.SectionID = SymInfo.getSectionID();
1218 Value.Offset = SymInfo.getOffset();
1219 Value.Addend = SymInfo.getOffset() + Addend;
1220 } else {
1221 switch (SymType) {
1222 case SymbolRef::ST_Debug: {
1223 // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously
1224 // and can be changed by another developers. Maybe best way is add
1225 // a new symbol type ST_Section to SymbolRef and use it.
1226 auto SectionOrErr = Symbol->getSection();
1227 if (!SectionOrErr) {
1228 std::string Buf;
1229 raw_string_ostream OS(Buf);
1230 logAllUnhandledErrors(SectionOrErr.takeError(), OS);
1231 OS.flush();
1232 report_fatal_error(Buf);
1233 }
1234 section_iterator si = *SectionOrErr;
1235 if (si == Obj.section_end())
1236 llvm_unreachable("Symbol section not found, bad object file format!");
1237 LLVM_DEBUG(dbgs() << "\t\tThis is section symbol\n");
1238 bool isCode = si->isText();
1239 if (auto SectionIDOrErr = findOrEmitSection(Obj, (*si), isCode,
1240 ObjSectionToID))
1241 Value.SectionID = *SectionIDOrErr;
1242 else
1243 return SectionIDOrErr.takeError();
1244 Value.Addend = Addend;
1245 break;
1246 }
1247 case SymbolRef::ST_Data:
1248 case SymbolRef::ST_Function:
1249 case SymbolRef::ST_Unknown: {
1250 Value.SymbolName = TargetName.data();
1251 Value.Addend = Addend;
1252
1253 // Absolute relocations will have a zero symbol ID (STN_UNDEF), which
1254 // will manifest here as a NULL symbol name.
1255 // We can set this as a valid (but empty) symbol name, and rely
1256 // on addRelocationForSymbol to handle this.
1257 if (!Value.SymbolName)
1258 Value.SymbolName = "";
1259 break;
1260 }
1261 default:
1262 llvm_unreachable("Unresolved symbol type!");
1263 break;
1264 }
1265 }
1266
1267 uint64_t Offset = RelI->getOffset();
1268
1269 LLVM_DEBUG(dbgs() << "\t\tSectionID: " << SectionID << " Offset: " << Offset
1270 << "\n");
1271 if ((Arch == Triple::aarch64 || Arch == Triple::aarch64_be)) {
1272 if ((RelType == ELF::R_AARCH64_CALL26 ||
1273 RelType == ELF::R_AARCH64_JUMP26) &&
1274 MemMgr.allowStubAllocation()) {
1275 resolveAArch64Branch(SectionID, Value, RelI, Stubs);
1276 } else if (RelType == ELF::R_AARCH64_ADR_GOT_PAGE) {
1277 // Craete new GOT entry or find existing one. If GOT entry is
1278 // to be created, then we also emit ABS64 relocation for it.
1279 uint64_t GOTOffset = findOrAllocGOTEntry(Value, ELF::R_AARCH64_ABS64);
1280 resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend,
1281 ELF::R_AARCH64_ADR_PREL_PG_HI21);
1282
1283 } else if (RelType == ELF::R_AARCH64_LD64_GOT_LO12_NC) {
1284 uint64_t GOTOffset = findOrAllocGOTEntry(Value, ELF::R_AARCH64_ABS64);
1285 resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend,
1286 ELF::R_AARCH64_LDST64_ABS_LO12_NC);
1287 } else {
1288 processSimpleRelocation(SectionID, Offset, RelType, Value);
1289 }
1290 } else if (Arch == Triple::arm) {
1291 if (RelType == ELF::R_ARM_PC24 || RelType == ELF::R_ARM_CALL ||
1292 RelType == ELF::R_ARM_JUMP24) {
1293 // This is an ARM branch relocation, need to use a stub function.
1294 LLVM_DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.\n");
1295 SectionEntry &Section = Sections[SectionID];
1296
1297 // Look for an existing stub.
1298 StubMap::const_iterator i = Stubs.find(Value);
1299 if (i != Stubs.end()) {
1300 resolveRelocation(
1301 Section, Offset,
1302 reinterpret_cast<uint64_t>(Section.getAddressWithOffset(i->second)),
1303 RelType, 0);
1304 LLVM_DEBUG(dbgs() << " Stub function found\n");
1305 } else {
1306 // Create a new stub function.
1307 LLVM_DEBUG(dbgs() << " Create a new stub function\n");
1308 Stubs[Value] = Section.getStubOffset();
1309 uint8_t *StubTargetAddr = createStubFunction(
1310 Section.getAddressWithOffset(Section.getStubOffset()));
1311 RelocationEntry RE(SectionID, StubTargetAddr - Section.getAddress(),
1312 ELF::R_ARM_ABS32, Value.Addend);
1313 if (Value.SymbolName)
1314 addRelocationForSymbol(RE, Value.SymbolName);
1315 else
1316 addRelocationForSection(RE, Value.SectionID);
1317
1318 resolveRelocation(Section, Offset, reinterpret_cast<uint64_t>(
1319 Section.getAddressWithOffset(
1320 Section.getStubOffset())),
1321 RelType, 0);
1322 Section.advanceStubOffset(getMaxStubSize());
1323 }
1324 } else {
1325 uint32_t *Placeholder =
1326 reinterpret_cast<uint32_t*>(computePlaceholderAddress(SectionID, Offset));
1327 if (RelType == ELF::R_ARM_PREL31 || RelType == ELF::R_ARM_TARGET1 ||
1328 RelType == ELF::R_ARM_ABS32) {
1329 Value.Addend += *Placeholder;
1330 } else if (RelType == ELF::R_ARM_MOVW_ABS_NC || RelType == ELF::R_ARM_MOVT_ABS) {
1331 // See ELF for ARM documentation
1332 Value.Addend += (int16_t)((*Placeholder & 0xFFF) | (((*Placeholder >> 16) & 0xF) << 12));
1333 }
1334 processSimpleRelocation(SectionID, Offset, RelType, Value);
1335 }
1336 } else if (IsMipsO32ABI) {
1337 uint8_t *Placeholder = reinterpret_cast<uint8_t *>(
1338 computePlaceholderAddress(SectionID, Offset));
1339 uint32_t Opcode = readBytesUnaligned(Placeholder, 4);
1340 if (RelType == ELF::R_MIPS_26) {
1341 // This is an Mips branch relocation, need to use a stub function.
1342 LLVM_DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
1343 SectionEntry &Section = Sections[SectionID];
1344
1345 // Extract the addend from the instruction.
1346 // We shift up by two since the Value will be down shifted again
1347 // when applying the relocation.
1348 uint32_t Addend = (Opcode & 0x03ffffff) << 2;
1349
1350 Value.Addend += Addend;
1351
1352 // Look up for existing stub.
1353 StubMap::const_iterator i = Stubs.find(Value);
1354 if (i != Stubs.end()) {
1355 RelocationEntry RE(SectionID, Offset, RelType, i->second);
1356 addRelocationForSection(RE, SectionID);
1357 LLVM_DEBUG(dbgs() << " Stub function found\n");
1358 } else {
1359 // Create a new stub function.
1360 LLVM_DEBUG(dbgs() << " Create a new stub function\n");
1361 Stubs[Value] = Section.getStubOffset();
1362
1363 unsigned AbiVariant = Obj.getPlatformFlags();
1364
1365 uint8_t *StubTargetAddr = createStubFunction(
1366 Section.getAddressWithOffset(Section.getStubOffset()), AbiVariant);
1367
1368 // Creating Hi and Lo relocations for the filled stub instructions.
1369 RelocationEntry REHi(SectionID, StubTargetAddr - Section.getAddress(),
1370 ELF::R_MIPS_HI16, Value.Addend);
1371 RelocationEntry RELo(SectionID,
1372 StubTargetAddr - Section.getAddress() + 4,
1373 ELF::R_MIPS_LO16, Value.Addend);
1374
1375 if (Value.SymbolName) {
1376 addRelocationForSymbol(REHi, Value.SymbolName);
1377 addRelocationForSymbol(RELo, Value.SymbolName);
1378 } else {
1379 addRelocationForSection(REHi, Value.SectionID);
1380 addRelocationForSection(RELo, Value.SectionID);
1381 }
1382
1383 RelocationEntry RE(SectionID, Offset, RelType, Section.getStubOffset());
1384 addRelocationForSection(RE, SectionID);
1385 Section.advanceStubOffset(getMaxStubSize());
1386 }
1387 } else if (RelType == ELF::R_MIPS_HI16 || RelType == ELF::R_MIPS_PCHI16) {
1388 int64_t Addend = (Opcode & 0x0000ffff) << 16;
1389 RelocationEntry RE(SectionID, Offset, RelType, Addend);
1390 PendingRelocs.push_back(std::make_pair(Value, RE));
1391 } else if (RelType == ELF::R_MIPS_LO16 || RelType == ELF::R_MIPS_PCLO16) {
1392 int64_t Addend = Value.Addend + SignExtend32<16>(Opcode & 0x0000ffff);
1393 for (auto I = PendingRelocs.begin(); I != PendingRelocs.end();) {
1394 const RelocationValueRef &MatchingValue = I->first;
1395 RelocationEntry &Reloc = I->second;
1396 if (MatchingValue == Value &&
1397 RelType == getMatchingLoRelocation(Reloc.RelType) &&
1398 SectionID == Reloc.SectionID) {
1399 Reloc.Addend += Addend;
1400 if (Value.SymbolName)
1401 addRelocationForSymbol(Reloc, Value.SymbolName);
1402 else
1403 addRelocationForSection(Reloc, Value.SectionID);
1404 I = PendingRelocs.erase(I);
1405 } else
1406 ++I;
1407 }
1408 RelocationEntry RE(SectionID, Offset, RelType, Addend);
1409 if (Value.SymbolName)
1410 addRelocationForSymbol(RE, Value.SymbolName);
1411 else
1412 addRelocationForSection(RE, Value.SectionID);
1413 } else {
1414 if (RelType == ELF::R_MIPS_32)
1415 Value.Addend += Opcode;
1416 else if (RelType == ELF::R_MIPS_PC16)
1417 Value.Addend += SignExtend32<18>((Opcode & 0x0000ffff) << 2);
1418 else if (RelType == ELF::R_MIPS_PC19_S2)
1419 Value.Addend += SignExtend32<21>((Opcode & 0x0007ffff) << 2);
1420 else if (RelType == ELF::R_MIPS_PC21_S2)
1421 Value.Addend += SignExtend32<23>((Opcode & 0x001fffff) << 2);
1422 else if (RelType == ELF::R_MIPS_PC26_S2)
1423 Value.Addend += SignExtend32<28>((Opcode & 0x03ffffff) << 2);
1424 processSimpleRelocation(SectionID, Offset, RelType, Value);
1425 }
1426 } else if (IsMipsN32ABI || IsMipsN64ABI) {
1427 uint32_t r_type = RelType & 0xff;
1428 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1429 if (r_type == ELF::R_MIPS_CALL16 || r_type == ELF::R_MIPS_GOT_PAGE
1430 || r_type == ELF::R_MIPS_GOT_DISP) {
1431 StringMap<uint64_t>::iterator i = GOTSymbolOffsets.find(TargetName);
1432 if (i != GOTSymbolOffsets.end())
1433 RE.SymOffset = i->second;
1434 else {
1435 RE.SymOffset = allocateGOTEntries(1);
1436 GOTSymbolOffsets[TargetName] = RE.SymOffset;
1437 }
1438 if (Value.SymbolName)
1439 addRelocationForSymbol(RE, Value.SymbolName);
1440 else
1441 addRelocationForSection(RE, Value.SectionID);
1442 } else if (RelType == ELF::R_MIPS_26) {
1443 // This is an Mips branch relocation, need to use a stub function.
1444 LLVM_DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
1445 SectionEntry &Section = Sections[SectionID];
1446
1447 // Look up for existing stub.
1448 StubMap::const_iterator i = Stubs.find(Value);
1449 if (i != Stubs.end()) {
1450 RelocationEntry RE(SectionID, Offset, RelType, i->second);
1451 addRelocationForSection(RE, SectionID);
1452 LLVM_DEBUG(dbgs() << " Stub function found\n");
1453 } else {
1454 // Create a new stub function.
1455 LLVM_DEBUG(dbgs() << " Create a new stub function\n");
1456 Stubs[Value] = Section.getStubOffset();
1457
1458 unsigned AbiVariant = Obj.getPlatformFlags();
1459
1460 uint8_t *StubTargetAddr = createStubFunction(
1461 Section.getAddressWithOffset(Section.getStubOffset()), AbiVariant);
1462
1463 if (IsMipsN32ABI) {
1464 // Creating Hi and Lo relocations for the filled stub instructions.
1465 RelocationEntry REHi(SectionID, StubTargetAddr - Section.getAddress(),
1466 ELF::R_MIPS_HI16, Value.Addend);
1467 RelocationEntry RELo(SectionID,
1468 StubTargetAddr - Section.getAddress() + 4,
1469 ELF::R_MIPS_LO16, Value.Addend);
1470 if (Value.SymbolName) {
1471 addRelocationForSymbol(REHi, Value.SymbolName);
1472 addRelocationForSymbol(RELo, Value.SymbolName);
1473 } else {
1474 addRelocationForSection(REHi, Value.SectionID);
1475 addRelocationForSection(RELo, Value.SectionID);
1476 }
1477 } else {
1478 // Creating Highest, Higher, Hi and Lo relocations for the filled stub
1479 // instructions.
1480 RelocationEntry REHighest(SectionID,
1481 StubTargetAddr - Section.getAddress(),
1482 ELF::R_MIPS_HIGHEST, Value.Addend);
1483 RelocationEntry REHigher(SectionID,
1484 StubTargetAddr - Section.getAddress() + 4,
1485 ELF::R_MIPS_HIGHER, Value.Addend);
1486 RelocationEntry REHi(SectionID,
1487 StubTargetAddr - Section.getAddress() + 12,
1488 ELF::R_MIPS_HI16, Value.Addend);
1489 RelocationEntry RELo(SectionID,
1490 StubTargetAddr - Section.getAddress() + 20,
1491 ELF::R_MIPS_LO16, Value.Addend);
1492 if (Value.SymbolName) {
1493 addRelocationForSymbol(REHighest, Value.SymbolName);
1494 addRelocationForSymbol(REHigher, Value.SymbolName);
1495 addRelocationForSymbol(REHi, Value.SymbolName);
1496 addRelocationForSymbol(RELo, Value.SymbolName);
1497 } else {
1498 addRelocationForSection(REHighest, Value.SectionID);
1499 addRelocationForSection(REHigher, Value.SectionID);
1500 addRelocationForSection(REHi, Value.SectionID);
1501 addRelocationForSection(RELo, Value.SectionID);
1502 }
1503 }
1504 RelocationEntry RE(SectionID, Offset, RelType, Section.getStubOffset());
1505 addRelocationForSection(RE, SectionID);
1506 Section.advanceStubOffset(getMaxStubSize());
1507 }
1508 } else {
1509 processSimpleRelocation(SectionID, Offset, RelType, Value);
1510 }
1511
1512 } else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) {
1513 if (RelType == ELF::R_PPC64_REL24) {
1514 // Determine ABI variant in use for this object.
1515 unsigned AbiVariant = Obj.getPlatformFlags();
1516 AbiVariant &= ELF::EF_PPC64_ABI;
1517 // A PPC branch relocation will need a stub function if the target is
1518 // an external symbol (either Value.SymbolName is set, or SymType is
1519 // Symbol::ST_Unknown) or if the target address is not within the
1520 // signed 24-bits branch address.
1521 SectionEntry &Section = Sections[SectionID];
1522 uint8_t *Target = Section.getAddressWithOffset(Offset);
1523 bool RangeOverflow = false;
1524 bool IsExtern = Value.SymbolName || SymType == SymbolRef::ST_Unknown;
1525 if (!IsExtern) {
1526 if (AbiVariant != 2) {
1527 // In the ELFv1 ABI, a function call may point to the .opd entry,
1528 // so the final symbol value is calculated based on the relocation
1529 // values in the .opd section.
1530 if (auto Err = findOPDEntrySection(Obj, ObjSectionToID, Value))
1531 return std::move(Err);
1532 } else {
1533 // In the ELFv2 ABI, a function symbol may provide a local entry
1534 // point, which must be used for direct calls.
1535 if (Value.SectionID == SectionID){
1536 uint8_t SymOther = Symbol->getOther();
1537 Value.Addend += ELF::decodePPC64LocalEntryOffset(SymOther);
1538 }
1539 }
1540 uint8_t *RelocTarget =
1541 Sections[Value.SectionID].getAddressWithOffset(Value.Addend);
1542 int64_t delta = static_cast<int64_t>(Target - RelocTarget);
1543 // If it is within 26-bits branch range, just set the branch target
1544 if (SignExtend64<26>(delta) != delta) {
1545 RangeOverflow = true;
1546 } else if ((AbiVariant != 2) ||
1547 (AbiVariant == 2 && Value.SectionID == SectionID)) {
1548 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1549 addRelocationForSection(RE, Value.SectionID);
1550 }
1551 }
1552 if (IsExtern || (AbiVariant == 2 && Value.SectionID != SectionID) ||
1553 RangeOverflow) {
1554 // It is an external symbol (either Value.SymbolName is set, or
1555 // SymType is SymbolRef::ST_Unknown) or out of range.
1556 StubMap::const_iterator i = Stubs.find(Value);
1557 if (i != Stubs.end()) {
1558 // Symbol function stub already created, just relocate to it
1559 resolveRelocation(Section, Offset,
1560 reinterpret_cast<uint64_t>(
1561 Section.getAddressWithOffset(i->second)),
1562 RelType, 0);
1563 LLVM_DEBUG(dbgs() << " Stub function found\n");
1564 } else {
1565 // Create a new stub function.
1566 LLVM_DEBUG(dbgs() << " Create a new stub function\n");
1567 Stubs[Value] = Section.getStubOffset();
1568 uint8_t *StubTargetAddr = createStubFunction(
1569 Section.getAddressWithOffset(Section.getStubOffset()),
1570 AbiVariant);
1571 RelocationEntry RE(SectionID, StubTargetAddr - Section.getAddress(),
1572 ELF::R_PPC64_ADDR64, Value.Addend);
1573
1574 // Generates the 64-bits address loads as exemplified in section
1575 // 4.5.1 in PPC64 ELF ABI. Note that the relocations need to
1576 // apply to the low part of the instructions, so we have to update
1577 // the offset according to the target endianness.
1578 uint64_t StubRelocOffset = StubTargetAddr - Section.getAddress();
1579 if (!IsTargetLittleEndian)
1580 StubRelocOffset += 2;
1581
1582 RelocationEntry REhst(SectionID, StubRelocOffset + 0,
1583 ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend);
1584 RelocationEntry REhr(SectionID, StubRelocOffset + 4,
1585 ELF::R_PPC64_ADDR16_HIGHER, Value.Addend);
1586 RelocationEntry REh(SectionID, StubRelocOffset + 12,
1587 ELF::R_PPC64_ADDR16_HI, Value.Addend);
1588 RelocationEntry REl(SectionID, StubRelocOffset + 16,
1589 ELF::R_PPC64_ADDR16_LO, Value.Addend);
1590
1591 if (Value.SymbolName) {
1592 addRelocationForSymbol(REhst, Value.SymbolName);
1593 addRelocationForSymbol(REhr, Value.SymbolName);
1594 addRelocationForSymbol(REh, Value.SymbolName);
1595 addRelocationForSymbol(REl, Value.SymbolName);
1596 } else {
1597 addRelocationForSection(REhst, Value.SectionID);
1598 addRelocationForSection(REhr, Value.SectionID);
1599 addRelocationForSection(REh, Value.SectionID);
1600 addRelocationForSection(REl, Value.SectionID);
1601 }
1602
1603 resolveRelocation(Section, Offset, reinterpret_cast<uint64_t>(
1604 Section.getAddressWithOffset(
1605 Section.getStubOffset())),
1606 RelType, 0);
1607 Section.advanceStubOffset(getMaxStubSize());
1608 }
1609 if (IsExtern || (AbiVariant == 2 && Value.SectionID != SectionID)) {
1610 // Restore the TOC for external calls
1611 if (AbiVariant == 2)
1612 writeInt32BE(Target + 4, 0xE8410018); // ld r2,24(r1)
1613 else
1614 writeInt32BE(Target + 4, 0xE8410028); // ld r2,40(r1)
1615 }
1616 }
1617 } else if (RelType == ELF::R_PPC64_TOC16 ||
1618 RelType == ELF::R_PPC64_TOC16_DS ||
1619 RelType == ELF::R_PPC64_TOC16_LO ||
1620 RelType == ELF::R_PPC64_TOC16_LO_DS ||
1621 RelType == ELF::R_PPC64_TOC16_HI ||
1622 RelType == ELF::R_PPC64_TOC16_HA) {
1623 // These relocations are supposed to subtract the TOC address from
1624 // the final value. This does not fit cleanly into the RuntimeDyld
1625 // scheme, since there may be *two* sections involved in determining
1626 // the relocation value (the section of the symbol referred to by the
1627 // relocation, and the TOC section associated with the current module).
1628 //
1629 // Fortunately, these relocations are currently only ever generated
1630 // referring to symbols that themselves reside in the TOC, which means
1631 // that the two sections are actually the same. Thus they cancel out
1632 // and we can immediately resolve the relocation right now.
1633 switch (RelType) {
1634 case ELF::R_PPC64_TOC16: RelType = ELF::R_PPC64_ADDR16; break;
1635 case ELF::R_PPC64_TOC16_DS: RelType = ELF::R_PPC64_ADDR16_DS; break;
1636 case ELF::R_PPC64_TOC16_LO: RelType = ELF::R_PPC64_ADDR16_LO; break;
1637 case ELF::R_PPC64_TOC16_LO_DS: RelType = ELF::R_PPC64_ADDR16_LO_DS; break;
1638 case ELF::R_PPC64_TOC16_HI: RelType = ELF::R_PPC64_ADDR16_HI; break;
1639 case ELF::R_PPC64_TOC16_HA: RelType = ELF::R_PPC64_ADDR16_HA; break;
1640 default: llvm_unreachable("Wrong relocation type.");
1641 }
1642
1643 RelocationValueRef TOCValue;
1644 if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, TOCValue))
1645 return std::move(Err);
1646 if (Value.SymbolName || Value.SectionID != TOCValue.SectionID)
1647 llvm_unreachable("Unsupported TOC relocation.");
1648 Value.Addend -= TOCValue.Addend;
1649 resolveRelocation(Sections[SectionID], Offset, Value.Addend, RelType, 0);
1650 } else {
1651 // There are two ways to refer to the TOC address directly: either
1652 // via a ELF::R_PPC64_TOC relocation (where both symbol and addend are
1653 // ignored), or via any relocation that refers to the magic ".TOC."
1654 // symbols (in which case the addend is respected).
1655 if (RelType == ELF::R_PPC64_TOC) {
1656 RelType = ELF::R_PPC64_ADDR64;
1657 if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, Value))
1658 return std::move(Err);
1659 } else if (TargetName == ".TOC.") {
1660 if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, Value))
1661 return std::move(Err);
1662 Value.Addend += Addend;
1663 }
1664
1665 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1666
1667 if (Value.SymbolName)
1668 addRelocationForSymbol(RE, Value.SymbolName);
1669 else
1670 addRelocationForSection(RE, Value.SectionID);
1671 }
1672 } else if (Arch == Triple::systemz &&
1673 (RelType == ELF::R_390_PLT32DBL || RelType == ELF::R_390_GOTENT)) {
1674 // Create function stubs for both PLT and GOT references, regardless of
1675 // whether the GOT reference is to data or code. The stub contains the
1676 // full address of the symbol, as needed by GOT references, and the
1677 // executable part only adds an overhead of 8 bytes.
1678 //
1679 // We could try to conserve space by allocating the code and data
1680 // parts of the stub separately. However, as things stand, we allocate
1681 // a stub for every relocation, so using a GOT in JIT code should be
1682 // no less space efficient than using an explicit constant pool.
1683 LLVM_DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation.");
1684 SectionEntry &Section = Sections[SectionID];
1685
1686 // Look for an existing stub.
1687 StubMap::const_iterator i = Stubs.find(Value);
1688 uintptr_t StubAddress;
1689 if (i != Stubs.end()) {
1690 StubAddress = uintptr_t(Section.getAddressWithOffset(i->second));
1691 LLVM_DEBUG(dbgs() << " Stub function found\n");
1692 } else {
1693 // Create a new stub function.
1694 LLVM_DEBUG(dbgs() << " Create a new stub function\n");
1695
1696 uintptr_t BaseAddress = uintptr_t(Section.getAddress());
1697 uintptr_t StubAlignment = getStubAlignment();
1698 StubAddress =
1699 (BaseAddress + Section.getStubOffset() + StubAlignment - 1) &
1700 -StubAlignment;
1701 unsigned StubOffset = StubAddress - BaseAddress;
1702
1703 Stubs[Value] = StubOffset;
1704 createStubFunction((uint8_t *)StubAddress);
1705 RelocationEntry RE(SectionID, StubOffset + 8, ELF::R_390_64,
1706 Value.Offset);
1707 if (Value.SymbolName)
1708 addRelocationForSymbol(RE, Value.SymbolName);
1709 else
1710 addRelocationForSection(RE, Value.SectionID);
1711 Section.advanceStubOffset(getMaxStubSize());
1712 }
1713
1714 if (RelType == ELF::R_390_GOTENT)
1715 resolveRelocation(Section, Offset, StubAddress + 8, ELF::R_390_PC32DBL,
1716 Addend);
1717 else
1718 resolveRelocation(Section, Offset, StubAddress, RelType, Addend);
1719 } else if (Arch == Triple::x86_64) {
1720 if (RelType == ELF::R_X86_64_PLT32) {
1721 // The way the PLT relocations normally work is that the linker allocates
1722 // the
1723 // PLT and this relocation makes a PC-relative call into the PLT. The PLT
1724 // entry will then jump to an address provided by the GOT. On first call,
1725 // the
1726 // GOT address will point back into PLT code that resolves the symbol. After
1727 // the first call, the GOT entry points to the actual function.
1728 //
1729 // For local functions we're ignoring all of that here and just replacing
1730 // the PLT32 relocation type with PC32, which will translate the relocation
1731 // into a PC-relative call directly to the function. For external symbols we
1732 // can't be sure the function will be within 2^32 bytes of the call site, so
1733 // we need to create a stub, which calls into the GOT. This case is
1734 // equivalent to the usual PLT implementation except that we use the stub
1735 // mechanism in RuntimeDyld (which puts stubs at the end of the section)
1736 // rather than allocating a PLT section.
1737 if (Value.SymbolName && MemMgr.allowStubAllocation()) {
1738 // This is a call to an external function.
1739 // Look for an existing stub.
1740 SectionEntry *Section = &Sections[SectionID];
1741 StubMap::const_iterator i = Stubs.find(Value);
1742 uintptr_t StubAddress;
1743 if (i != Stubs.end()) {
1744 StubAddress = uintptr_t(Section->getAddress()) + i->second;
1745 LLVM_DEBUG(dbgs() << " Stub function found\n");
1746 } else {
1747 // Create a new stub function (equivalent to a PLT entry).
1748 LLVM_DEBUG(dbgs() << " Create a new stub function\n");
1749
1750 uintptr_t BaseAddress = uintptr_t(Section->getAddress());
1751 uintptr_t StubAlignment = getStubAlignment();
1752 StubAddress =
1753 (BaseAddress + Section->getStubOffset() + StubAlignment - 1) &
1754 -StubAlignment;
1755 unsigned StubOffset = StubAddress - BaseAddress;
1756 Stubs[Value] = StubOffset;
1757 createStubFunction((uint8_t *)StubAddress);
1758
1759 // Bump our stub offset counter
1760 Section->advanceStubOffset(getMaxStubSize());
1761
1762 // Allocate a GOT Entry
1763 uint64_t GOTOffset = allocateGOTEntries(1);
1764 // This potentially creates a new Section which potentially
1765 // invalidates the Section pointer, so reload it.
1766 Section = &Sections[SectionID];
1767
1768 // The load of the GOT address has an addend of -4
1769 resolveGOTOffsetRelocation(SectionID, StubOffset + 2, GOTOffset - 4,
1770 ELF::R_X86_64_PC32);
1771
1772 // Fill in the value of the symbol we're targeting into the GOT
1773 addRelocationForSymbol(
1774 computeGOTOffsetRE(GOTOffset, 0, ELF::R_X86_64_64),
1775 Value.SymbolName);
1776 }
1777
1778 // Make the target call a call into the stub table.
1779 resolveRelocation(*Section, Offset, StubAddress, ELF::R_X86_64_PC32,
1780 Addend);
1781 } else {
1782 Value.Addend += support::ulittle32_t::ref(
1783 computePlaceholderAddress(SectionID, Offset));
1784 processSimpleRelocation(SectionID, Offset, ELF::R_X86_64_PC32, Value);
1785 }
1786 } else if (RelType == ELF::R_X86_64_GOTPCREL ||
1787 RelType == ELF::R_X86_64_GOTPCRELX ||
1788 RelType == ELF::R_X86_64_REX_GOTPCRELX) {
1789 uint64_t GOTOffset = allocateGOTEntries(1);
1790 resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend,
1791 ELF::R_X86_64_PC32);
1792
1793 // Fill in the value of the symbol we're targeting into the GOT
1794 RelocationEntry RE =
1795 computeGOTOffsetRE(GOTOffset, Value.Offset, ELF::R_X86_64_64);
1796 if (Value.SymbolName)
1797 addRelocationForSymbol(RE, Value.SymbolName);
1798 else
1799 addRelocationForSection(RE, Value.SectionID);
1800 } else if (RelType == ELF::R_X86_64_GOT64) {
1801 // Fill in a 64-bit GOT offset.
1802 uint64_t GOTOffset = allocateGOTEntries(1);
1803 resolveRelocation(Sections[SectionID], Offset, GOTOffset,
1804 ELF::R_X86_64_64, 0);
1805
1806 // Fill in the value of the symbol we're targeting into the GOT
1807 RelocationEntry RE =
1808 computeGOTOffsetRE(GOTOffset, Value.Offset, ELF::R_X86_64_64);
1809 if (Value.SymbolName)
1810 addRelocationForSymbol(RE, Value.SymbolName);
1811 else
1812 addRelocationForSection(RE, Value.SectionID);
1813 } else if (RelType == ELF::R_X86_64_GOTPC64) {
1814 // Materialize the address of the base of the GOT relative to the PC.
1815 // This doesn't create a GOT entry, but it does mean we need a GOT
1816 // section.
1817 (void)allocateGOTEntries(0);
1818 resolveGOTOffsetRelocation(SectionID, Offset, Addend, ELF::R_X86_64_PC64);
1819 } else if (RelType == ELF::R_X86_64_GOTOFF64) {
1820 // GOTOFF relocations ultimately require a section difference relocation.
1821 (void)allocateGOTEntries(0);
1822 processSimpleRelocation(SectionID, Offset, RelType, Value);
1823 } else if (RelType == ELF::R_X86_64_PC32) {
1824 Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset));
1825 processSimpleRelocation(SectionID, Offset, RelType, Value);
1826 } else if (RelType == ELF::R_X86_64_PC64) {
1827 Value.Addend += support::ulittle64_t::ref(computePlaceholderAddress(SectionID, Offset));
1828 processSimpleRelocation(SectionID, Offset, RelType, Value);
1829 } else {
1830 processSimpleRelocation(SectionID, Offset, RelType, Value);
1831 }
1832 } else {
1833 if (Arch == Triple::x86) {
1834 Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset));
1835 }
1836 processSimpleRelocation(SectionID, Offset, RelType, Value);
1837 }
1838 return ++RelI;
1839 }
1840
getGOTEntrySize()1841 size_t RuntimeDyldELF::getGOTEntrySize() {
1842 // We don't use the GOT in all of these cases, but it's essentially free
1843 // to put them all here.
1844 size_t Result = 0;
1845 switch (Arch) {
1846 case Triple::x86_64:
1847 case Triple::aarch64:
1848 case Triple::aarch64_be:
1849 case Triple::ppc64:
1850 case Triple::ppc64le:
1851 case Triple::systemz:
1852 Result = sizeof(uint64_t);
1853 break;
1854 case Triple::x86:
1855 case Triple::arm:
1856 case Triple::thumb:
1857 Result = sizeof(uint32_t);
1858 break;
1859 case Triple::mips:
1860 case Triple::mipsel:
1861 case Triple::mips64:
1862 case Triple::mips64el:
1863 if (IsMipsO32ABI || IsMipsN32ABI)
1864 Result = sizeof(uint32_t);
1865 else if (IsMipsN64ABI)
1866 Result = sizeof(uint64_t);
1867 else
1868 llvm_unreachable("Mips ABI not handled");
1869 break;
1870 default:
1871 llvm_unreachable("Unsupported CPU type!");
1872 }
1873 return Result;
1874 }
1875
allocateGOTEntries(unsigned no)1876 uint64_t RuntimeDyldELF::allocateGOTEntries(unsigned no) {
1877 if (GOTSectionID == 0) {
1878 GOTSectionID = Sections.size();
1879 // Reserve a section id. We'll allocate the section later
1880 // once we know the total size
1881 Sections.push_back(SectionEntry(".got", nullptr, 0, 0, 0));
1882 }
1883 uint64_t StartOffset = CurrentGOTIndex * getGOTEntrySize();
1884 CurrentGOTIndex += no;
1885 return StartOffset;
1886 }
1887
findOrAllocGOTEntry(const RelocationValueRef & Value,unsigned GOTRelType)1888 uint64_t RuntimeDyldELF::findOrAllocGOTEntry(const RelocationValueRef &Value,
1889 unsigned GOTRelType) {
1890 auto E = GOTOffsetMap.insert({Value, 0});
1891 if (E.second) {
1892 uint64_t GOTOffset = allocateGOTEntries(1);
1893
1894 // Create relocation for newly created GOT entry
1895 RelocationEntry RE =
1896 computeGOTOffsetRE(GOTOffset, Value.Offset, GOTRelType);
1897 if (Value.SymbolName)
1898 addRelocationForSymbol(RE, Value.SymbolName);
1899 else
1900 addRelocationForSection(RE, Value.SectionID);
1901
1902 E.first->second = GOTOffset;
1903 }
1904
1905 return E.first->second;
1906 }
1907
resolveGOTOffsetRelocation(unsigned SectionID,uint64_t Offset,uint64_t GOTOffset,uint32_t Type)1908 void RuntimeDyldELF::resolveGOTOffsetRelocation(unsigned SectionID,
1909 uint64_t Offset,
1910 uint64_t GOTOffset,
1911 uint32_t Type) {
1912 // Fill in the relative address of the GOT Entry into the stub
1913 RelocationEntry GOTRE(SectionID, Offset, Type, GOTOffset);
1914 addRelocationForSection(GOTRE, GOTSectionID);
1915 }
1916
computeGOTOffsetRE(uint64_t GOTOffset,uint64_t SymbolOffset,uint32_t Type)1917 RelocationEntry RuntimeDyldELF::computeGOTOffsetRE(uint64_t GOTOffset,
1918 uint64_t SymbolOffset,
1919 uint32_t Type) {
1920 return RelocationEntry(GOTSectionID, GOTOffset, Type, SymbolOffset);
1921 }
1922
finalizeLoad(const ObjectFile & Obj,ObjSectionToIDMap & SectionMap)1923 Error RuntimeDyldELF::finalizeLoad(const ObjectFile &Obj,
1924 ObjSectionToIDMap &SectionMap) {
1925 if (IsMipsO32ABI)
1926 if (!PendingRelocs.empty())
1927 return make_error<RuntimeDyldError>("Can't find matching LO16 reloc");
1928
1929 // If necessary, allocate the global offset table
1930 if (GOTSectionID != 0) {
1931 // Allocate memory for the section
1932 size_t TotalSize = CurrentGOTIndex * getGOTEntrySize();
1933 uint8_t *Addr = MemMgr.allocateDataSection(TotalSize, getGOTEntrySize(),
1934 GOTSectionID, ".got", false);
1935 if (!Addr)
1936 return make_error<RuntimeDyldError>("Unable to allocate memory for GOT!");
1937
1938 Sections[GOTSectionID] =
1939 SectionEntry(".got", Addr, TotalSize, TotalSize, 0);
1940
1941 // For now, initialize all GOT entries to zero. We'll fill them in as
1942 // needed when GOT-based relocations are applied.
1943 memset(Addr, 0, TotalSize);
1944 if (IsMipsN32ABI || IsMipsN64ABI) {
1945 // To correctly resolve Mips GOT relocations, we need a mapping from
1946 // object's sections to GOTs.
1947 for (section_iterator SI = Obj.section_begin(), SE = Obj.section_end();
1948 SI != SE; ++SI) {
1949 if (SI->relocation_begin() != SI->relocation_end()) {
1950 Expected<section_iterator> RelSecOrErr = SI->getRelocatedSection();
1951 if (!RelSecOrErr)
1952 return make_error<RuntimeDyldError>(
1953 toString(RelSecOrErr.takeError()));
1954
1955 section_iterator RelocatedSection = *RelSecOrErr;
1956 ObjSectionToIDMap::iterator i = SectionMap.find(*RelocatedSection);
1957 assert (i != SectionMap.end());
1958 SectionToGOTMap[i->second] = GOTSectionID;
1959 }
1960 }
1961 GOTSymbolOffsets.clear();
1962 }
1963 }
1964
1965 // Look for and record the EH frame section.
1966 ObjSectionToIDMap::iterator i, e;
1967 for (i = SectionMap.begin(), e = SectionMap.end(); i != e; ++i) {
1968 const SectionRef &Section = i->first;
1969
1970 StringRef Name;
1971 Expected<StringRef> NameOrErr = Section.getName();
1972 if (NameOrErr)
1973 Name = *NameOrErr;
1974 else
1975 consumeError(NameOrErr.takeError());
1976
1977 if (Name == ".eh_frame") {
1978 UnregisteredEHFrameSections.push_back(i->second);
1979 break;
1980 }
1981 }
1982
1983 GOTSectionID = 0;
1984 CurrentGOTIndex = 0;
1985
1986 return Error::success();
1987 }
1988
isCompatibleFile(const object::ObjectFile & Obj) const1989 bool RuntimeDyldELF::isCompatibleFile(const object::ObjectFile &Obj) const {
1990 return Obj.isELF();
1991 }
1992
relocationNeedsGot(const RelocationRef & R) const1993 bool RuntimeDyldELF::relocationNeedsGot(const RelocationRef &R) const {
1994 unsigned RelTy = R.getType();
1995 if (Arch == Triple::aarch64 || Arch == Triple::aarch64_be)
1996 return RelTy == ELF::R_AARCH64_ADR_GOT_PAGE ||
1997 RelTy == ELF::R_AARCH64_LD64_GOT_LO12_NC;
1998
1999 if (Arch == Triple::x86_64)
2000 return RelTy == ELF::R_X86_64_GOTPCREL ||
2001 RelTy == ELF::R_X86_64_GOTPCRELX ||
2002 RelTy == ELF::R_X86_64_GOT64 ||
2003 RelTy == ELF::R_X86_64_REX_GOTPCRELX;
2004 return false;
2005 }
2006
relocationNeedsStub(const RelocationRef & R) const2007 bool RuntimeDyldELF::relocationNeedsStub(const RelocationRef &R) const {
2008 if (Arch != Triple::x86_64)
2009 return true; // Conservative answer
2010
2011 switch (R.getType()) {
2012 default:
2013 return true; // Conservative answer
2014
2015
2016 case ELF::R_X86_64_GOTPCREL:
2017 case ELF::R_X86_64_GOTPCRELX:
2018 case ELF::R_X86_64_REX_GOTPCRELX:
2019 case ELF::R_X86_64_GOTPC64:
2020 case ELF::R_X86_64_GOT64:
2021 case ELF::R_X86_64_GOTOFF64:
2022 case ELF::R_X86_64_PC32:
2023 case ELF::R_X86_64_PC64:
2024 case ELF::R_X86_64_64:
2025 // We know that these reloation types won't need a stub function. This list
2026 // can be extended as needed.
2027 return false;
2028 }
2029 }
2030
2031 } // namespace llvm
2032