1 //===-- RuntimeDyldELF.cpp - Run-time dynamic linker for MC-JIT -*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // Implementation of ELF support for the MC-JIT runtime dynamic linker.
12 //===----------------------------------------------------------------------===//
14 #include "RuntimeDyldELF.h"
15 #include "RuntimeDyldCheckerImpl.h"
16 #include "Targets/RuntimeDyldELFMips.h"
17 #include "llvm/ADT/IntervalMap.h"
18 #include "llvm/ADT/STLExtras.h"
19 #include "llvm/ADT/StringRef.h"
20 #include "llvm/ADT/Triple.h"
21 #include "llvm/MC/MCStreamer.h"
22 #include "llvm/Object/ELFObjectFile.h"
23 #include "llvm/Object/ObjectFile.h"
24 #include "llvm/Support/ELF.h"
25 #include "llvm/Support/Endian.h"
26 #include "llvm/Support/MemoryBuffer.h"
27 #include "llvm/Support/TargetRegistry.h"
30 using namespace llvm::object;
31 using namespace llvm::support::endian;
33 #define DEBUG_TYPE "dyld"
35 static void or32le(void *P, int32_t V) { write32le(P, read32le(P) | V); }
37 static void or32AArch64Imm(void *L, uint64_t Imm) {
38 or32le(L, (Imm & 0xFFF) << 10);
41 template <class T> static void write(bool isBE, void *P, T V) {
42 isBE ? write<T, support::big>(P, V) : write<T, support::little>(P, V);
45 static void write32AArch64Addr(void *L, uint64_t Imm) {
46 uint32_t ImmLo = (Imm & 0x3) << 29;
47 uint32_t ImmHi = (Imm & 0x1FFFFC) << 3;
48 uint64_t Mask = (0x3 << 29) | (0x1FFFFC << 3);
49 write32le(L, (read32le(L) & ~Mask) | ImmLo | ImmHi);
52 // Return the bits [Start, End] from Val shifted Start bits.
53 // For instance, getBits(0xF0, 4, 8) returns 0xF.
54 static uint64_t getBits(uint64_t Val, int Start, int End) {
55 uint64_t Mask = ((uint64_t)1 << (End + 1 - Start)) - 1;
56 return (Val >> Start) & Mask;
61 template <class ELFT> class DyldELFObject : public ELFObjectFile<ELFT> {
62 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
64 typedef Elf_Shdr_Impl<ELFT> Elf_Shdr;
65 typedef Elf_Sym_Impl<ELFT> Elf_Sym;
66 typedef Elf_Rel_Impl<ELFT, false> Elf_Rel;
67 typedef Elf_Rel_Impl<ELFT, true> Elf_Rela;
69 typedef Elf_Ehdr_Impl<ELFT> Elf_Ehdr;
71 typedef typename ELFDataTypeTypedefHelper<ELFT>::value_type addr_type;
74 DyldELFObject(MemoryBufferRef Wrapper, std::error_code &ec);
76 void updateSectionAddress(const SectionRef &Sec, uint64_t Addr);
78 void updateSymbolAddress(const SymbolRef &SymRef, uint64_t Addr);
80 // Methods for type inquiry through isa, cast and dyn_cast
81 static inline bool classof(const Binary *v) {
82 return (isa<ELFObjectFile<ELFT>>(v) &&
83 classof(cast<ELFObjectFile<ELFT>>(v)));
85 static inline bool classof(const ELFObjectFile<ELFT> *v) {
86 return v->isDyldType();
92 // The MemoryBuffer passed into this constructor is just a wrapper around the
93 // actual memory. Ultimately, the Binary parent class will take ownership of
94 // this MemoryBuffer object but not the underlying memory.
96 DyldELFObject<ELFT>::DyldELFObject(MemoryBufferRef Wrapper, std::error_code &EC)
97 : ELFObjectFile<ELFT>(Wrapper, EC) {
98 this->isDyldELFObject = true;
101 template <class ELFT>
102 void DyldELFObject<ELFT>::updateSectionAddress(const SectionRef &Sec,
104 DataRefImpl ShdrRef = Sec.getRawDataRefImpl();
106 const_cast<Elf_Shdr *>(reinterpret_cast<const Elf_Shdr *>(ShdrRef.p));
108 // This assumes the address passed in matches the target address bitness
109 // The template-based type cast handles everything else.
110 shdr->sh_addr = static_cast<addr_type>(Addr);
113 template <class ELFT>
114 void DyldELFObject<ELFT>::updateSymbolAddress(const SymbolRef &SymRef,
117 Elf_Sym *sym = const_cast<Elf_Sym *>(
118 ELFObjectFile<ELFT>::getSymbol(SymRef.getRawDataRefImpl()));
120 // This assumes the address passed in matches the target address bitness
121 // The template-based type cast handles everything else.
122 sym->st_value = static_cast<addr_type>(Addr);
125 class LoadedELFObjectInfo final
126 : public RuntimeDyld::LoadedObjectInfoHelper<LoadedELFObjectInfo> {
128 LoadedELFObjectInfo(RuntimeDyldImpl &RTDyld, ObjSectionToIDMap ObjSecToIDMap)
129 : LoadedObjectInfoHelper(RTDyld, std::move(ObjSecToIDMap)) {}
131 OwningBinary<ObjectFile>
132 getObjectForDebug(const ObjectFile &Obj) const override;
135 template <typename ELFT>
136 std::unique_ptr<DyldELFObject<ELFT>>
137 createRTDyldELFObject(MemoryBufferRef Buffer,
138 const ObjectFile &SourceObject,
139 const LoadedELFObjectInfo &L,
140 std::error_code &ec) {
141 typedef typename ELFFile<ELFT>::Elf_Shdr Elf_Shdr;
142 typedef typename ELFDataTypeTypedefHelper<ELFT>::value_type addr_type;
144 std::unique_ptr<DyldELFObject<ELFT>> Obj =
145 llvm::make_unique<DyldELFObject<ELFT>>(Buffer, ec);
147 // Iterate over all sections in the object.
148 auto SI = SourceObject.section_begin();
149 for (const auto &Sec : Obj->sections()) {
150 StringRef SectionName;
151 Sec.getName(SectionName);
152 if (SectionName != "") {
153 DataRefImpl ShdrRef = Sec.getRawDataRefImpl();
154 Elf_Shdr *shdr = const_cast<Elf_Shdr *>(
155 reinterpret_cast<const Elf_Shdr *>(ShdrRef.p));
157 if (uint64_t SecLoadAddr = L.getSectionLoadAddress(*SI)) {
158 // This assumes that the address passed in matches the target address
159 // bitness. The template-based type cast handles everything else.
160 shdr->sh_addr = static_cast<addr_type>(SecLoadAddr);
169 OwningBinary<ObjectFile> createELFDebugObject(const ObjectFile &Obj,
170 const LoadedELFObjectInfo &L) {
171 assert(Obj.isELF() && "Not an ELF object file.");
173 std::unique_ptr<MemoryBuffer> Buffer =
174 MemoryBuffer::getMemBufferCopy(Obj.getData(), Obj.getFileName());
178 std::unique_ptr<ObjectFile> DebugObj;
179 if (Obj.getBytesInAddress() == 4 && Obj.isLittleEndian()) {
180 typedef ELFType<support::little, false> ELF32LE;
181 DebugObj = createRTDyldELFObject<ELF32LE>(Buffer->getMemBufferRef(), Obj, L,
183 } else if (Obj.getBytesInAddress() == 4 && !Obj.isLittleEndian()) {
184 typedef ELFType<support::big, false> ELF32BE;
185 DebugObj = createRTDyldELFObject<ELF32BE>(Buffer->getMemBufferRef(), Obj, L,
187 } else if (Obj.getBytesInAddress() == 8 && !Obj.isLittleEndian()) {
188 typedef ELFType<support::big, true> ELF64BE;
189 DebugObj = createRTDyldELFObject<ELF64BE>(Buffer->getMemBufferRef(), Obj, L,
191 } else if (Obj.getBytesInAddress() == 8 && Obj.isLittleEndian()) {
192 typedef ELFType<support::little, true> ELF64LE;
193 DebugObj = createRTDyldELFObject<ELF64LE>(Buffer->getMemBufferRef(), Obj, L,
196 llvm_unreachable("Unexpected ELF format");
198 assert(!ec && "Could not construct copy ELF object file");
200 return OwningBinary<ObjectFile>(std::move(DebugObj), std::move(Buffer));
203 OwningBinary<ObjectFile>
204 LoadedELFObjectInfo::getObjectForDebug(const ObjectFile &Obj) const {
205 return createELFDebugObject(Obj, *this);
208 } // anonymous namespace
212 RuntimeDyldELF::RuntimeDyldELF(RuntimeDyld::MemoryManager &MemMgr,
213 JITSymbolResolver &Resolver)
214 : RuntimeDyldImpl(MemMgr, Resolver), GOTSectionID(0), CurrentGOTIndex(0) {}
215 RuntimeDyldELF::~RuntimeDyldELF() {}
217 void RuntimeDyldELF::registerEHFrames() {
218 for (int i = 0, e = UnregisteredEHFrameSections.size(); i != e; ++i) {
219 SID EHFrameSID = UnregisteredEHFrameSections[i];
220 uint8_t *EHFrameAddr = Sections[EHFrameSID].getAddress();
221 uint64_t EHFrameLoadAddr = Sections[EHFrameSID].getLoadAddress();
222 size_t EHFrameSize = Sections[EHFrameSID].getSize();
223 MemMgr.registerEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
225 UnregisteredEHFrameSections.clear();
228 std::unique_ptr<RuntimeDyldELF>
229 llvm::RuntimeDyldELF::create(Triple::ArchType Arch,
230 RuntimeDyld::MemoryManager &MemMgr,
231 JITSymbolResolver &Resolver) {
234 return make_unique<RuntimeDyldELF>(MemMgr, Resolver);
238 case Triple::mips64el:
239 return make_unique<RuntimeDyldELFMips>(MemMgr, Resolver);
243 std::unique_ptr<RuntimeDyld::LoadedObjectInfo>
244 RuntimeDyldELF::loadObject(const object::ObjectFile &O) {
245 if (auto ObjSectionToIDOrErr = loadObjectImpl(O))
246 return llvm::make_unique<LoadedELFObjectInfo>(*this, *ObjSectionToIDOrErr);
249 raw_string_ostream ErrStream(ErrorStr);
250 logAllUnhandledErrors(ObjSectionToIDOrErr.takeError(), ErrStream, "");
255 void RuntimeDyldELF::resolveX86_64Relocation(const SectionEntry &Section,
256 uint64_t Offset, uint64_t Value,
257 uint32_t Type, int64_t Addend,
258 uint64_t SymOffset) {
261 llvm_unreachable("Relocation type not implemented yet!");
263 case ELF::R_X86_64_NONE:
265 case ELF::R_X86_64_64: {
266 support::ulittle64_t::ref(Section.getAddressWithOffset(Offset)) =
268 DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend)) << " at "
269 << format("%p\n", Section.getAddressWithOffset(Offset)));
272 case ELF::R_X86_64_32:
273 case ELF::R_X86_64_32S: {
275 assert((Type == ELF::R_X86_64_32 && (Value <= UINT32_MAX)) ||
276 (Type == ELF::R_X86_64_32S &&
277 ((int64_t)Value <= INT32_MAX && (int64_t)Value >= INT32_MIN)));
278 uint32_t TruncatedAddr = (Value & 0xFFFFFFFF);
279 support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) =
281 DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr) << " at "
282 << format("%p\n", Section.getAddressWithOffset(Offset)));
285 case ELF::R_X86_64_PC8: {
286 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
287 int64_t RealOffset = Value + Addend - FinalAddress;
288 assert(isInt<8>(RealOffset));
289 int8_t TruncOffset = (RealOffset & 0xFF);
290 Section.getAddress()[Offset] = TruncOffset;
293 case ELF::R_X86_64_PC32: {
294 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
295 int64_t RealOffset = Value + Addend - FinalAddress;
296 assert(isInt<32>(RealOffset));
297 int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
298 support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) =
302 case ELF::R_X86_64_PC64: {
303 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
304 int64_t RealOffset = Value + Addend - FinalAddress;
305 support::ulittle64_t::ref(Section.getAddressWithOffset(Offset)) =
312 void RuntimeDyldELF::resolveX86Relocation(const SectionEntry &Section,
313 uint64_t Offset, uint32_t Value,
314 uint32_t Type, int32_t Addend) {
316 case ELF::R_386_32: {
317 support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) =
321 case ELF::R_386_PC32: {
322 uint32_t FinalAddress =
323 Section.getLoadAddressWithOffset(Offset) & 0xFFFFFFFF;
324 uint32_t RealOffset = Value + Addend - FinalAddress;
325 support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) =
330 // There are other relocation types, but it appears these are the
331 // only ones currently used by the LLVM ELF object writer
332 llvm_unreachable("Relocation type not implemented yet!");
337 void RuntimeDyldELF::resolveAArch64Relocation(const SectionEntry &Section,
338 uint64_t Offset, uint64_t Value,
339 uint32_t Type, int64_t Addend) {
340 uint32_t *TargetPtr =
341 reinterpret_cast<uint32_t *>(Section.getAddressWithOffset(Offset));
342 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
343 // Data should use target endian. Code should always use little endian.
344 bool isBE = Arch == Triple::aarch64_be;
346 DEBUG(dbgs() << "resolveAArch64Relocation, LocalAddress: 0x"
347 << format("%llx", Section.getAddressWithOffset(Offset))
348 << " FinalAddress: 0x" << format("%llx", FinalAddress)
349 << " Value: 0x" << format("%llx", Value) << " Type: 0x"
350 << format("%x", Type) << " Addend: 0x" << format("%llx", Addend)
355 llvm_unreachable("Relocation type not implemented yet!");
357 case ELF::R_AARCH64_ABS64:
358 write(isBE, TargetPtr, Value + Addend);
360 case ELF::R_AARCH64_PREL32: {
361 uint64_t Result = Value + Addend - FinalAddress;
362 assert(static_cast<int64_t>(Result) >= INT32_MIN &&
363 static_cast<int64_t>(Result) <= UINT32_MAX);
364 write(isBE, TargetPtr, static_cast<uint32_t>(Result & 0xffffffffU));
367 case ELF::R_AARCH64_PREL64:
368 write(isBE, TargetPtr, Value + Addend - FinalAddress);
370 case ELF::R_AARCH64_CALL26: // fallthrough
371 case ELF::R_AARCH64_JUMP26: {
372 // Operation: S+A-P. Set Call or B immediate value to bits fff_fffc of the
374 uint64_t BranchImm = Value + Addend - FinalAddress;
376 // "Check that -2^27 <= result < 2^27".
377 assert(isInt<28>(BranchImm));
378 or32le(TargetPtr, (BranchImm & 0x0FFFFFFC) >> 2);
381 case ELF::R_AARCH64_MOVW_UABS_G3:
382 or32le(TargetPtr, ((Value + Addend) & 0xFFFF000000000000) >> 43);
384 case ELF::R_AARCH64_MOVW_UABS_G2_NC:
385 or32le(TargetPtr, ((Value + Addend) & 0xFFFF00000000) >> 27);
387 case ELF::R_AARCH64_MOVW_UABS_G1_NC:
388 or32le(TargetPtr, ((Value + Addend) & 0xFFFF0000) >> 11);
390 case ELF::R_AARCH64_MOVW_UABS_G0_NC:
391 or32le(TargetPtr, ((Value + Addend) & 0xFFFF) << 5);
393 case ELF::R_AARCH64_ADR_PREL_PG_HI21: {
394 // Operation: Page(S+A) - Page(P)
396 ((Value + Addend) & ~0xfffULL) - (FinalAddress & ~0xfffULL);
398 // Check that -2^32 <= X < 2^32
399 assert(isInt<33>(Result) && "overflow check failed for relocation");
401 // Immediate goes in bits 30:29 + 5:23 of ADRP instruction, taken
402 // from bits 32:12 of X.
403 write32AArch64Addr(TargetPtr, Result >> 12);
406 case ELF::R_AARCH64_ADD_ABS_LO12_NC:
408 // Immediate goes in bits 21:10 of LD/ST instruction, taken
409 // from bits 11:0 of X
410 or32AArch64Imm(TargetPtr, Value + Addend);
412 case ELF::R_AARCH64_LDST8_ABS_LO12_NC:
414 // Immediate goes in bits 21:10 of LD/ST instruction, taken
415 // from bits 11:0 of X
416 or32AArch64Imm(TargetPtr, getBits(Value + Addend, 0, 11));
418 case ELF::R_AARCH64_LDST16_ABS_LO12_NC:
420 // Immediate goes in bits 21:10 of LD/ST instruction, taken
421 // from bits 11:1 of X
422 or32AArch64Imm(TargetPtr, getBits(Value + Addend, 1, 11));
424 case ELF::R_AARCH64_LDST32_ABS_LO12_NC:
426 // Immediate goes in bits 21:10 of LD/ST instruction, taken
427 // from bits 11:2 of X
428 or32AArch64Imm(TargetPtr, getBits(Value + Addend, 2, 11));
430 case ELF::R_AARCH64_LDST64_ABS_LO12_NC:
432 // Immediate goes in bits 21:10 of LD/ST instruction, taken
433 // from bits 11:3 of X
434 or32AArch64Imm(TargetPtr, getBits(Value + Addend, 3, 11));
436 case ELF::R_AARCH64_LDST128_ABS_LO12_NC:
438 // Immediate goes in bits 21:10 of LD/ST instruction, taken
439 // from bits 11:4 of X
440 or32AArch64Imm(TargetPtr, getBits(Value + Addend, 4, 11));
445 void RuntimeDyldELF::resolveARMRelocation(const SectionEntry &Section,
446 uint64_t Offset, uint32_t Value,
447 uint32_t Type, int32_t Addend) {
448 // TODO: Add Thumb relocations.
449 uint32_t *TargetPtr =
450 reinterpret_cast<uint32_t *>(Section.getAddressWithOffset(Offset));
451 uint32_t FinalAddress = Section.getLoadAddressWithOffset(Offset) & 0xFFFFFFFF;
454 DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: "
455 << Section.getAddressWithOffset(Offset)
456 << " FinalAddress: " << format("%p", FinalAddress) << " Value: "
457 << format("%x", Value) << " Type: " << format("%x", Type)
458 << " Addend: " << format("%x", Addend) << "\n");
462 llvm_unreachable("Not implemented relocation type!");
464 case ELF::R_ARM_NONE:
466 // Write a 31bit signed offset
467 case ELF::R_ARM_PREL31:
468 support::ulittle32_t::ref{TargetPtr} =
469 (support::ulittle32_t::ref{TargetPtr} & 0x80000000) |
470 ((Value - FinalAddress) & ~0x80000000);
472 case ELF::R_ARM_TARGET1:
473 case ELF::R_ARM_ABS32:
474 support::ulittle32_t::ref{TargetPtr} = Value;
476 // Write first 16 bit of 32 bit value to the mov instruction.
477 // Last 4 bit should be shifted.
478 case ELF::R_ARM_MOVW_ABS_NC:
479 case ELF::R_ARM_MOVT_ABS:
480 if (Type == ELF::R_ARM_MOVW_ABS_NC)
481 Value = Value & 0xFFFF;
482 else if (Type == ELF::R_ARM_MOVT_ABS)
483 Value = (Value >> 16) & 0xFFFF;
484 support::ulittle32_t::ref{TargetPtr} =
485 (support::ulittle32_t::ref{TargetPtr} & ~0x000F0FFF) | (Value & 0xFFF) |
486 (((Value >> 12) & 0xF) << 16);
488 // Write 24 bit relative value to the branch instruction.
489 case ELF::R_ARM_PC24: // Fall through.
490 case ELF::R_ARM_CALL: // Fall through.
491 case ELF::R_ARM_JUMP24:
492 int32_t RelValue = static_cast<int32_t>(Value - FinalAddress - 8);
493 RelValue = (RelValue & 0x03FFFFFC) >> 2;
494 assert((support::ulittle32_t::ref{TargetPtr} & 0xFFFFFF) == 0xFFFFFE);
495 support::ulittle32_t::ref{TargetPtr} =
496 (support::ulittle32_t::ref{TargetPtr} & 0xFF000000) | RelValue;
501 void RuntimeDyldELF::setMipsABI(const ObjectFile &Obj) {
502 if (Arch == Triple::UnknownArch ||
503 !StringRef(Triple::getArchTypePrefix(Arch)).equals("mips")) {
504 IsMipsO32ABI = false;
505 IsMipsN32ABI = false;
506 IsMipsN64ABI = false;
510 Obj.getPlatformFlags(AbiVariant);
511 IsMipsO32ABI = AbiVariant & ELF::EF_MIPS_ABI_O32;
512 IsMipsN32ABI = AbiVariant & ELF::EF_MIPS_ABI2;
513 IsMipsN64ABI = Obj.getFileFormatName().equals("ELF64-mips");
516 // Return the .TOC. section and offset.
517 Error RuntimeDyldELF::findPPC64TOCSection(const ELFObjectFileBase &Obj,
518 ObjSectionToIDMap &LocalSections,
519 RelocationValueRef &Rel) {
520 // Set a default SectionID in case we do not find a TOC section below.
521 // This may happen for references to TOC base base (sym@toc, .odp
522 // relocation) without a .toc directive. In this case just use the
523 // first section (which is usually the .odp) since the code won't
524 // reference the .toc base directly.
525 Rel.SymbolName = nullptr;
528 // The TOC consists of sections .got, .toc, .tocbss, .plt in that
529 // order. The TOC starts where the first of these sections starts.
530 for (auto &Section: Obj.sections()) {
531 StringRef SectionName;
532 if (auto EC = Section.getName(SectionName))
533 return errorCodeToError(EC);
535 if (SectionName == ".got"
536 || SectionName == ".toc"
537 || SectionName == ".tocbss"
538 || SectionName == ".plt") {
539 if (auto SectionIDOrErr =
540 findOrEmitSection(Obj, Section, false, LocalSections))
541 Rel.SectionID = *SectionIDOrErr;
543 return SectionIDOrErr.takeError();
548 // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000
549 // thus permitting a full 64 Kbytes segment.
552 return Error::success();
555 // Returns the sections and offset associated with the ODP entry referenced
557 Error RuntimeDyldELF::findOPDEntrySection(const ELFObjectFileBase &Obj,
558 ObjSectionToIDMap &LocalSections,
559 RelocationValueRef &Rel) {
560 // Get the ELF symbol value (st_value) to compare with Relocation offset in
562 for (section_iterator si = Obj.section_begin(), se = Obj.section_end();
564 section_iterator RelSecI = si->getRelocatedSection();
565 if (RelSecI == Obj.section_end())
568 StringRef RelSectionName;
569 if (auto EC = RelSecI->getName(RelSectionName))
570 return errorCodeToError(EC);
572 if (RelSectionName != ".opd")
575 for (elf_relocation_iterator i = si->relocation_begin(),
576 e = si->relocation_end();
578 // The R_PPC64_ADDR64 relocation indicates the first field
580 uint64_t TypeFunc = i->getType();
581 if (TypeFunc != ELF::R_PPC64_ADDR64) {
586 uint64_t TargetSymbolOffset = i->getOffset();
587 symbol_iterator TargetSymbol = i->getSymbol();
589 if (auto AddendOrErr = i->getAddend())
590 Addend = *AddendOrErr;
592 return errorCodeToError(AddendOrErr.getError());
598 // Just check if following relocation is a R_PPC64_TOC
599 uint64_t TypeTOC = i->getType();
600 if (TypeTOC != ELF::R_PPC64_TOC)
603 // Finally compares the Symbol value and the target symbol offset
604 // to check if this .opd entry refers to the symbol the relocation
606 if (Rel.Addend != (int64_t)TargetSymbolOffset)
609 section_iterator TSI = Obj.section_end();
610 if (auto TSIOrErr = TargetSymbol->getSection())
613 return TSIOrErr.takeError();
614 assert(TSI != Obj.section_end() && "TSI should refer to a valid section");
616 bool IsCode = TSI->isText();
617 if (auto SectionIDOrErr = findOrEmitSection(Obj, *TSI, IsCode,
619 Rel.SectionID = *SectionIDOrErr;
621 return SectionIDOrErr.takeError();
622 Rel.Addend = (intptr_t)Addend;
623 return Error::success();
626 llvm_unreachable("Attempting to get address of ODP entry!");
629 // Relocation masks following the #lo(value), #hi(value), #ha(value),
630 // #higher(value), #highera(value), #highest(value), and #highesta(value)
631 // macros defined in section 4.5.1. Relocation Types of the PPC-elf64abi
634 static inline uint16_t applyPPClo(uint64_t value) { return value & 0xffff; }
636 static inline uint16_t applyPPChi(uint64_t value) {
637 return (value >> 16) & 0xffff;
640 static inline uint16_t applyPPCha (uint64_t value) {
641 return ((value + 0x8000) >> 16) & 0xffff;
644 static inline uint16_t applyPPChigher(uint64_t value) {
645 return (value >> 32) & 0xffff;
648 static inline uint16_t applyPPChighera (uint64_t value) {
649 return ((value + 0x8000) >> 32) & 0xffff;
652 static inline uint16_t applyPPChighest(uint64_t value) {
653 return (value >> 48) & 0xffff;
656 static inline uint16_t applyPPChighesta (uint64_t value) {
657 return ((value + 0x8000) >> 48) & 0xffff;
660 void RuntimeDyldELF::resolvePPC32Relocation(const SectionEntry &Section,
661 uint64_t Offset, uint64_t Value,
662 uint32_t Type, int64_t Addend) {
663 uint8_t *LocalAddress = Section.getAddressWithOffset(Offset);
666 llvm_unreachable("Relocation type not implemented yet!");
668 case ELF::R_PPC_ADDR16_LO:
669 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
671 case ELF::R_PPC_ADDR16_HI:
672 writeInt16BE(LocalAddress, applyPPChi(Value + Addend));
674 case ELF::R_PPC_ADDR16_HA:
675 writeInt16BE(LocalAddress, applyPPCha(Value + Addend));
680 void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section,
681 uint64_t Offset, uint64_t Value,
682 uint32_t Type, int64_t Addend) {
683 uint8_t *LocalAddress = Section.getAddressWithOffset(Offset);
686 llvm_unreachable("Relocation type not implemented yet!");
688 case ELF::R_PPC64_ADDR16:
689 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
691 case ELF::R_PPC64_ADDR16_DS:
692 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
694 case ELF::R_PPC64_ADDR16_LO:
695 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
697 case ELF::R_PPC64_ADDR16_LO_DS:
698 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
700 case ELF::R_PPC64_ADDR16_HI:
701 writeInt16BE(LocalAddress, applyPPChi(Value + Addend));
703 case ELF::R_PPC64_ADDR16_HA:
704 writeInt16BE(LocalAddress, applyPPCha(Value + Addend));
706 case ELF::R_PPC64_ADDR16_HIGHER:
707 writeInt16BE(LocalAddress, applyPPChigher(Value + Addend));
709 case ELF::R_PPC64_ADDR16_HIGHERA:
710 writeInt16BE(LocalAddress, applyPPChighera(Value + Addend));
712 case ELF::R_PPC64_ADDR16_HIGHEST:
713 writeInt16BE(LocalAddress, applyPPChighest(Value + Addend));
715 case ELF::R_PPC64_ADDR16_HIGHESTA:
716 writeInt16BE(LocalAddress, applyPPChighesta(Value + Addend));
718 case ELF::R_PPC64_ADDR14: {
719 assert(((Value + Addend) & 3) == 0);
720 // Preserve the AA/LK bits in the branch instruction
721 uint8_t aalk = *(LocalAddress + 3);
722 writeInt16BE(LocalAddress + 2, (aalk & 3) | ((Value + Addend) & 0xfffc));
724 case ELF::R_PPC64_REL16_LO: {
725 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
726 uint64_t Delta = Value - FinalAddress + Addend;
727 writeInt16BE(LocalAddress, applyPPClo(Delta));
729 case ELF::R_PPC64_REL16_HI: {
730 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
731 uint64_t Delta = Value - FinalAddress + Addend;
732 writeInt16BE(LocalAddress, applyPPChi(Delta));
734 case ELF::R_PPC64_REL16_HA: {
735 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
736 uint64_t Delta = Value - FinalAddress + Addend;
737 writeInt16BE(LocalAddress, applyPPCha(Delta));
739 case ELF::R_PPC64_ADDR32: {
740 int64_t Result = static_cast<int64_t>(Value + Addend);
741 if (SignExtend64<32>(Result) != Result)
742 llvm_unreachable("Relocation R_PPC64_ADDR32 overflow");
743 writeInt32BE(LocalAddress, Result);
745 case ELF::R_PPC64_REL24: {
746 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
747 int64_t delta = static_cast<int64_t>(Value - FinalAddress + Addend);
748 if (SignExtend64<26>(delta) != delta)
749 llvm_unreachable("Relocation R_PPC64_REL24 overflow");
750 // Generates a 'bl <address>' instruction
751 writeInt32BE(LocalAddress, 0x48000001 | (delta & 0x03FFFFFC));
753 case ELF::R_PPC64_REL32: {
754 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
755 int64_t delta = static_cast<int64_t>(Value - FinalAddress + Addend);
756 if (SignExtend64<32>(delta) != delta)
757 llvm_unreachable("Relocation R_PPC64_REL32 overflow");
758 writeInt32BE(LocalAddress, delta);
760 case ELF::R_PPC64_REL64: {
761 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
762 uint64_t Delta = Value - FinalAddress + Addend;
763 writeInt64BE(LocalAddress, Delta);
765 case ELF::R_PPC64_ADDR64:
766 writeInt64BE(LocalAddress, Value + Addend);
771 void RuntimeDyldELF::resolveSystemZRelocation(const SectionEntry &Section,
772 uint64_t Offset, uint64_t Value,
773 uint32_t Type, int64_t Addend) {
774 uint8_t *LocalAddress = Section.getAddressWithOffset(Offset);
777 llvm_unreachable("Relocation type not implemented yet!");
779 case ELF::R_390_PC16DBL:
780 case ELF::R_390_PLT16DBL: {
781 int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset);
782 assert(int16_t(Delta / 2) * 2 == Delta && "R_390_PC16DBL overflow");
783 writeInt16BE(LocalAddress, Delta / 2);
786 case ELF::R_390_PC32DBL:
787 case ELF::R_390_PLT32DBL: {
788 int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset);
789 assert(int32_t(Delta / 2) * 2 == Delta && "R_390_PC32DBL overflow");
790 writeInt32BE(LocalAddress, Delta / 2);
793 case ELF::R_390_PC16: {
794 int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset);
795 assert(int16_t(Delta) == Delta && "R_390_PC16 overflow");
796 writeInt16BE(LocalAddress, Delta);
799 case ELF::R_390_PC32: {
800 int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset);
801 assert(int32_t(Delta) == Delta && "R_390_PC32 overflow");
802 writeInt32BE(LocalAddress, Delta);
805 case ELF::R_390_PC64: {
806 int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset);
807 writeInt64BE(LocalAddress, Delta);
811 *LocalAddress = (uint8_t)(Value + Addend);
814 writeInt16BE(LocalAddress, Value + Addend);
817 writeInt32BE(LocalAddress, Value + Addend);
820 writeInt64BE(LocalAddress, Value + Addend);
825 void RuntimeDyldELF::resolveBPFRelocation(const SectionEntry &Section,
826 uint64_t Offset, uint64_t Value,
827 uint32_t Type, int64_t Addend) {
828 bool isBE = Arch == Triple::bpfeb;
832 llvm_unreachable("Relocation type not implemented yet!");
834 case ELF::R_BPF_NONE:
836 case ELF::R_BPF_64_64: {
837 write(isBE, Section.getAddressWithOffset(Offset), Value + Addend);
838 DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend)) << " at "
839 << format("%p\n", Section.getAddressWithOffset(Offset)));
842 case ELF::R_BPF_64_32: {
844 assert(Value <= UINT32_MAX);
845 write(isBE, Section.getAddressWithOffset(Offset), static_cast<uint32_t>(Value));
846 DEBUG(dbgs() << "Writing " << format("%p", Value) << " at "
847 << format("%p\n", Section.getAddressWithOffset(Offset)));
853 // The target location for the relocation is described by RE.SectionID and
854 // RE.Offset. RE.SectionID can be used to find the SectionEntry. Each
855 // SectionEntry has three members describing its location.
856 // SectionEntry::Address is the address at which the section has been loaded
857 // into memory in the current (host) process. SectionEntry::LoadAddress is the
858 // address that the section will have in the target process.
859 // SectionEntry::ObjAddress is the address of the bits for this section in the
860 // original emitted object image (also in the current address space).
862 // Relocations will be applied as if the section were loaded at
863 // SectionEntry::LoadAddress, but they will be applied at an address based
864 // on SectionEntry::Address. SectionEntry::ObjAddress will be used to refer to
865 // Target memory contents if they are required for value calculations.
867 // The Value parameter here is the load address of the symbol for the
868 // relocation to be applied. For relocations which refer to symbols in the
869 // current object Value will be the LoadAddress of the section in which
870 // the symbol resides (RE.Addend provides additional information about the
871 // symbol location). For external symbols, Value will be the address of the
872 // symbol in the target address space.
873 void RuntimeDyldELF::resolveRelocation(const RelocationEntry &RE,
875 const SectionEntry &Section = Sections[RE.SectionID];
876 return resolveRelocation(Section, RE.Offset, Value, RE.RelType, RE.Addend,
877 RE.SymOffset, RE.SectionID);
880 void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section,
881 uint64_t Offset, uint64_t Value,
882 uint32_t Type, int64_t Addend,
883 uint64_t SymOffset, SID SectionID) {
886 resolveX86_64Relocation(Section, Offset, Value, Type, Addend, SymOffset);
889 resolveX86Relocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
890 (uint32_t)(Addend & 0xffffffffL));
892 case Triple::aarch64:
893 case Triple::aarch64_be:
894 resolveAArch64Relocation(Section, Offset, Value, Type, Addend);
896 case Triple::arm: // Fall through.
899 case Triple::thumbeb:
900 resolveARMRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
901 (uint32_t)(Addend & 0xffffffffL));
904 resolvePPC32Relocation(Section, Offset, Value, Type, Addend);
906 case Triple::ppc64: // Fall through.
907 case Triple::ppc64le:
908 resolvePPC64Relocation(Section, Offset, Value, Type, Addend);
910 case Triple::systemz:
911 resolveSystemZRelocation(Section, Offset, Value, Type, Addend);
915 resolveBPFRelocation(Section, Offset, Value, Type, Addend);
918 llvm_unreachable("Unsupported CPU type!");
922 void *RuntimeDyldELF::computePlaceholderAddress(unsigned SectionID, uint64_t Offset) const {
923 return (void *)(Sections[SectionID].getObjAddress() + Offset);
926 void RuntimeDyldELF::processSimpleRelocation(unsigned SectionID, uint64_t Offset, unsigned RelType, RelocationValueRef Value) {
927 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend, Value.Offset);
928 if (Value.SymbolName)
929 addRelocationForSymbol(RE, Value.SymbolName);
931 addRelocationForSection(RE, Value.SectionID);
934 uint32_t RuntimeDyldELF::getMatchingLoRelocation(uint32_t RelType,
935 bool IsLocal) const {
937 case ELF::R_MICROMIPS_GOT16:
939 return ELF::R_MICROMIPS_LO16;
941 case ELF::R_MICROMIPS_HI16:
942 return ELF::R_MICROMIPS_LO16;
943 case ELF::R_MIPS_GOT16:
945 return ELF::R_MIPS_LO16;
947 case ELF::R_MIPS_HI16:
948 return ELF::R_MIPS_LO16;
949 case ELF::R_MIPS_PCHI16:
950 return ELF::R_MIPS_PCLO16;
954 return ELF::R_MIPS_NONE;
957 // Sometimes we don't need to create thunk for a branch.
958 // This typically happens when branch target is located
959 // in the same object file. In such case target is either
960 // a weak symbol or symbol in a different executable section.
961 // This function checks if branch target is located in the
962 // same object file and if distance between source and target
963 // fits R_AARCH64_CALL26 relocation. If both conditions are
964 // met, it emits direct jump to the target and returns true.
965 // Otherwise false is returned and thunk is created.
966 bool RuntimeDyldELF::resolveAArch64ShortBranch(
967 unsigned SectionID, relocation_iterator RelI,
968 const RelocationValueRef &Value) {
970 if (Value.SymbolName) {
971 auto Loc = GlobalSymbolTable.find(Value.SymbolName);
973 // Don't create direct branch for external symbols.
974 if (Loc == GlobalSymbolTable.end())
977 const auto &SymInfo = Loc->second;
979 uint64_t(Sections[SymInfo.getSectionID()].getLoadAddressWithOffset(
980 SymInfo.getOffset()));
982 Address = uint64_t(Sections[Value.SectionID].getLoadAddress());
984 uint64_t Offset = RelI->getOffset();
985 uint64_t SourceAddress = Sections[SectionID].getLoadAddressWithOffset(Offset);
987 // R_AARCH64_CALL26 requires immediate to be in range -2^27 <= imm < 2^27
988 // If distance between source and target is out of range then we should
990 if (!isInt<28>(Address + Value.Addend - SourceAddress))
993 resolveRelocation(Sections[SectionID], Offset, Address, RelI->getType(),
999 void RuntimeDyldELF::resolveAArch64Branch(unsigned SectionID,
1000 const RelocationValueRef &Value,
1001 relocation_iterator RelI,
1004 DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation.");
1005 SectionEntry &Section = Sections[SectionID];
1007 uint64_t Offset = RelI->getOffset();
1008 unsigned RelType = RelI->getType();
1009 // Look for an existing stub.
1010 StubMap::const_iterator i = Stubs.find(Value);
1011 if (i != Stubs.end()) {
1012 resolveRelocation(Section, Offset,
1013 (uint64_t)Section.getAddressWithOffset(i->second),
1015 DEBUG(dbgs() << " Stub function found\n");
1016 } else if (!resolveAArch64ShortBranch(SectionID, RelI, Value)) {
1017 // Create a new stub function.
1018 DEBUG(dbgs() << " Create a new stub function\n");
1019 Stubs[Value] = Section.getStubOffset();
1020 uint8_t *StubTargetAddr = createStubFunction(
1021 Section.getAddressWithOffset(Section.getStubOffset()));
1023 RelocationEntry REmovz_g3(SectionID, StubTargetAddr - Section.getAddress(),
1024 ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend);
1025 RelocationEntry REmovk_g2(SectionID,
1026 StubTargetAddr - Section.getAddress() + 4,
1027 ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend);
1028 RelocationEntry REmovk_g1(SectionID,
1029 StubTargetAddr - Section.getAddress() + 8,
1030 ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend);
1031 RelocationEntry REmovk_g0(SectionID,
1032 StubTargetAddr - Section.getAddress() + 12,
1033 ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend);
1035 if (Value.SymbolName) {
1036 addRelocationForSymbol(REmovz_g3, Value.SymbolName);
1037 addRelocationForSymbol(REmovk_g2, Value.SymbolName);
1038 addRelocationForSymbol(REmovk_g1, Value.SymbolName);
1039 addRelocationForSymbol(REmovk_g0, Value.SymbolName);
1041 addRelocationForSection(REmovz_g3, Value.SectionID);
1042 addRelocationForSection(REmovk_g2, Value.SectionID);
1043 addRelocationForSection(REmovk_g1, Value.SectionID);
1044 addRelocationForSection(REmovk_g0, Value.SectionID);
1046 resolveRelocation(Section, Offset,
1047 reinterpret_cast<uint64_t>(Section.getAddressWithOffset(
1048 Section.getStubOffset())),
1050 Section.advanceStubOffset(getMaxStubSize());
1054 Expected<relocation_iterator>
1055 RuntimeDyldELF::processRelocationRef(
1056 unsigned SectionID, relocation_iterator RelI, const ObjectFile &O,
1057 ObjSectionToIDMap &ObjSectionToID, StubMap &Stubs) {
1058 const auto &Obj = cast<ELFObjectFileBase>(O);
1059 uint64_t RelType = RelI->getType();
1060 ErrorOr<int64_t> AddendOrErr = ELFRelocationRef(*RelI).getAddend();
1061 int64_t Addend = AddendOrErr ? *AddendOrErr : 0;
1062 elf_symbol_iterator Symbol = RelI->getSymbol();
1064 // Obtain the symbol name which is referenced in the relocation
1065 StringRef TargetName;
1066 if (Symbol != Obj.symbol_end()) {
1067 if (auto TargetNameOrErr = Symbol->getName())
1068 TargetName = *TargetNameOrErr;
1070 return TargetNameOrErr.takeError();
1072 DEBUG(dbgs() << "\t\tRelType: " << RelType << " Addend: " << Addend
1073 << " TargetName: " << TargetName << "\n");
1074 RelocationValueRef Value;
1075 // First search for the symbol in the local symbol table
1076 SymbolRef::Type SymType = SymbolRef::ST_Unknown;
1078 // Search for the symbol in the global symbol table
1079 RTDyldSymbolTable::const_iterator gsi = GlobalSymbolTable.end();
1080 if (Symbol != Obj.symbol_end()) {
1081 gsi = GlobalSymbolTable.find(TargetName.data());
1082 Expected<SymbolRef::Type> SymTypeOrErr = Symbol->getType();
1083 if (!SymTypeOrErr) {
1085 raw_string_ostream OS(Buf);
1086 logAllUnhandledErrors(SymTypeOrErr.takeError(), OS, "");
1088 report_fatal_error(Buf);
1090 SymType = *SymTypeOrErr;
1092 if (gsi != GlobalSymbolTable.end()) {
1093 const auto &SymInfo = gsi->second;
1094 Value.SectionID = SymInfo.getSectionID();
1095 Value.Offset = SymInfo.getOffset();
1096 Value.Addend = SymInfo.getOffset() + Addend;
1099 case SymbolRef::ST_Debug: {
1100 // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously
1101 // and can be changed by another developers. Maybe best way is add
1102 // a new symbol type ST_Section to SymbolRef and use it.
1103 auto SectionOrErr = Symbol->getSection();
1104 if (!SectionOrErr) {
1106 raw_string_ostream OS(Buf);
1107 logAllUnhandledErrors(SectionOrErr.takeError(), OS, "");
1109 report_fatal_error(Buf);
1111 section_iterator si = *SectionOrErr;
1112 if (si == Obj.section_end())
1113 llvm_unreachable("Symbol section not found, bad object file format!");
1114 DEBUG(dbgs() << "\t\tThis is section symbol\n");
1115 bool isCode = si->isText();
1116 if (auto SectionIDOrErr = findOrEmitSection(Obj, (*si), isCode,
1118 Value.SectionID = *SectionIDOrErr;
1120 return SectionIDOrErr.takeError();
1121 Value.Addend = Addend;
1124 case SymbolRef::ST_Data:
1125 case SymbolRef::ST_Function:
1126 case SymbolRef::ST_Unknown: {
1127 Value.SymbolName = TargetName.data();
1128 Value.Addend = Addend;
1130 // Absolute relocations will have a zero symbol ID (STN_UNDEF), which
1131 // will manifest here as a NULL symbol name.
1132 // We can set this as a valid (but empty) symbol name, and rely
1133 // on addRelocationForSymbol to handle this.
1134 if (!Value.SymbolName)
1135 Value.SymbolName = "";
1139 llvm_unreachable("Unresolved symbol type!");
1144 uint64_t Offset = RelI->getOffset();
1146 DEBUG(dbgs() << "\t\tSectionID: " << SectionID << " Offset: " << Offset
1148 if ((Arch == Triple::aarch64 || Arch == Triple::aarch64_be)) {
1149 if (RelType == ELF::R_AARCH64_CALL26 || RelType == ELF::R_AARCH64_JUMP26) {
1150 resolveAArch64Branch(SectionID, Value, RelI, Stubs);
1151 } else if (RelType == ELF::R_AARCH64_ADR_GOT_PAGE) {
1152 // Craete new GOT entry or find existing one. If GOT entry is
1153 // to be created, then we also emit ABS64 relocation for it.
1154 uint64_t GOTOffset = findOrAllocGOTEntry(Value, ELF::R_AARCH64_ABS64);
1155 resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend,
1156 ELF::R_AARCH64_ADR_PREL_PG_HI21);
1158 } else if (RelType == ELF::R_AARCH64_LD64_GOT_LO12_NC) {
1159 uint64_t GOTOffset = findOrAllocGOTEntry(Value, ELF::R_AARCH64_ABS64);
1160 resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend,
1161 ELF::R_AARCH64_LDST64_ABS_LO12_NC);
1163 processSimpleRelocation(SectionID, Offset, RelType, Value);
1165 } else if (Arch == Triple::arm) {
1166 if (RelType == ELF::R_ARM_PC24 || RelType == ELF::R_ARM_CALL ||
1167 RelType == ELF::R_ARM_JUMP24) {
1168 // This is an ARM branch relocation, need to use a stub function.
1169 DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.\n");
1170 SectionEntry &Section = Sections[SectionID];
1172 // Look for an existing stub.
1173 StubMap::const_iterator i = Stubs.find(Value);
1174 if (i != Stubs.end()) {
1177 reinterpret_cast<uint64_t>(Section.getAddressWithOffset(i->second)),
1179 DEBUG(dbgs() << " Stub function found\n");
1181 // Create a new stub function.
1182 DEBUG(dbgs() << " Create a new stub function\n");
1183 Stubs[Value] = Section.getStubOffset();
1184 uint8_t *StubTargetAddr = createStubFunction(
1185 Section.getAddressWithOffset(Section.getStubOffset()));
1186 RelocationEntry RE(SectionID, StubTargetAddr - Section.getAddress(),
1187 ELF::R_ARM_ABS32, Value.Addend);
1188 if (Value.SymbolName)
1189 addRelocationForSymbol(RE, Value.SymbolName);
1191 addRelocationForSection(RE, Value.SectionID);
1193 resolveRelocation(Section, Offset, reinterpret_cast<uint64_t>(
1194 Section.getAddressWithOffset(
1195 Section.getStubOffset())),
1197 Section.advanceStubOffset(getMaxStubSize());
1200 uint32_t *Placeholder =
1201 reinterpret_cast<uint32_t*>(computePlaceholderAddress(SectionID, Offset));
1202 if (RelType == ELF::R_ARM_PREL31 || RelType == ELF::R_ARM_TARGET1 ||
1203 RelType == ELF::R_ARM_ABS32) {
1204 Value.Addend += *Placeholder;
1205 } else if (RelType == ELF::R_ARM_MOVW_ABS_NC || RelType == ELF::R_ARM_MOVT_ABS) {
1206 // See ELF for ARM documentation
1207 Value.Addend += (int16_t)((*Placeholder & 0xFFF) | (((*Placeholder >> 16) & 0xF) << 12));
1209 processSimpleRelocation(SectionID, Offset, RelType, Value);
1211 } else if (IsMipsO32ABI) {
1212 uint8_t *Placeholder = reinterpret_cast<uint8_t *>(
1213 computePlaceholderAddress(SectionID, Offset));
1214 uint32_t Opcode = readBytesUnaligned(Placeholder, 4);
1215 if (RelType == ELF::R_MIPS_26) {
1216 // This is an Mips branch relocation, need to use a stub function.
1217 DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
1218 SectionEntry &Section = Sections[SectionID];
1220 // Extract the addend from the instruction.
1221 // We shift up by two since the Value will be down shifted again
1222 // when applying the relocation.
1223 uint32_t Addend = (Opcode & 0x03ffffff) << 2;
1225 Value.Addend += Addend;
1227 // Look up for existing stub.
1228 StubMap::const_iterator i = Stubs.find(Value);
1229 if (i != Stubs.end()) {
1230 RelocationEntry RE(SectionID, Offset, RelType, i->second);
1231 addRelocationForSection(RE, SectionID);
1232 DEBUG(dbgs() << " Stub function found\n");
1234 // Create a new stub function.
1235 DEBUG(dbgs() << " Create a new stub function\n");
1236 Stubs[Value] = Section.getStubOffset();
1238 unsigned AbiVariant;
1239 O.getPlatformFlags(AbiVariant);
1241 uint8_t *StubTargetAddr = createStubFunction(
1242 Section.getAddressWithOffset(Section.getStubOffset()), AbiVariant);
1244 // Creating Hi and Lo relocations for the filled stub instructions.
1245 RelocationEntry REHi(SectionID, StubTargetAddr - Section.getAddress(),
1246 ELF::R_MIPS_HI16, Value.Addend);
1247 RelocationEntry RELo(SectionID,
1248 StubTargetAddr - Section.getAddress() + 4,
1249 ELF::R_MIPS_LO16, Value.Addend);
1251 if (Value.SymbolName) {
1252 addRelocationForSymbol(REHi, Value.SymbolName);
1253 addRelocationForSymbol(RELo, Value.SymbolName);
1256 addRelocationForSection(REHi, Value.SectionID);
1257 addRelocationForSection(RELo, Value.SectionID);
1260 RelocationEntry RE(SectionID, Offset, RelType, Section.getStubOffset());
1261 addRelocationForSection(RE, SectionID);
1262 Section.advanceStubOffset(getMaxStubSize());
1264 } else if (RelType == ELF::R_MIPS_HI16 || RelType == ELF::R_MIPS_PCHI16) {
1265 int64_t Addend = (Opcode & 0x0000ffff) << 16;
1266 RelocationEntry RE(SectionID, Offset, RelType, Addend);
1267 PendingRelocs.push_back(std::make_pair(Value, RE));
1268 } else if (RelType == ELF::R_MIPS_LO16 || RelType == ELF::R_MIPS_PCLO16) {
1269 int64_t Addend = Value.Addend + SignExtend32<16>(Opcode & 0x0000ffff);
1270 for (auto I = PendingRelocs.begin(); I != PendingRelocs.end();) {
1271 const RelocationValueRef &MatchingValue = I->first;
1272 RelocationEntry &Reloc = I->second;
1273 if (MatchingValue == Value &&
1274 RelType == getMatchingLoRelocation(Reloc.RelType) &&
1275 SectionID == Reloc.SectionID) {
1276 Reloc.Addend += Addend;
1277 if (Value.SymbolName)
1278 addRelocationForSymbol(Reloc, Value.SymbolName);
1280 addRelocationForSection(Reloc, Value.SectionID);
1281 I = PendingRelocs.erase(I);
1285 RelocationEntry RE(SectionID, Offset, RelType, Addend);
1286 if (Value.SymbolName)
1287 addRelocationForSymbol(RE, Value.SymbolName);
1289 addRelocationForSection(RE, Value.SectionID);
1291 if (RelType == ELF::R_MIPS_32)
1292 Value.Addend += Opcode;
1293 else if (RelType == ELF::R_MIPS_PC16)
1294 Value.Addend += SignExtend32<18>((Opcode & 0x0000ffff) << 2);
1295 else if (RelType == ELF::R_MIPS_PC19_S2)
1296 Value.Addend += SignExtend32<21>((Opcode & 0x0007ffff) << 2);
1297 else if (RelType == ELF::R_MIPS_PC21_S2)
1298 Value.Addend += SignExtend32<23>((Opcode & 0x001fffff) << 2);
1299 else if (RelType == ELF::R_MIPS_PC26_S2)
1300 Value.Addend += SignExtend32<28>((Opcode & 0x03ffffff) << 2);
1301 processSimpleRelocation(SectionID, Offset, RelType, Value);
1303 } else if (IsMipsN32ABI || IsMipsN64ABI) {
1304 uint32_t r_type = RelType & 0xff;
1305 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1306 if (r_type == ELF::R_MIPS_CALL16 || r_type == ELF::R_MIPS_GOT_PAGE
1307 || r_type == ELF::R_MIPS_GOT_DISP) {
1308 StringMap<uint64_t>::iterator i = GOTSymbolOffsets.find(TargetName);
1309 if (i != GOTSymbolOffsets.end())
1310 RE.SymOffset = i->second;
1312 RE.SymOffset = allocateGOTEntries(1);
1313 GOTSymbolOffsets[TargetName] = RE.SymOffset;
1316 if (Value.SymbolName)
1317 addRelocationForSymbol(RE, Value.SymbolName);
1319 addRelocationForSection(RE, Value.SectionID);
1320 } else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) {
1321 if (RelType == ELF::R_PPC64_REL24) {
1322 // Determine ABI variant in use for this object.
1323 unsigned AbiVariant;
1324 Obj.getPlatformFlags(AbiVariant);
1325 AbiVariant &= ELF::EF_PPC64_ABI;
1326 // A PPC branch relocation will need a stub function if the target is
1327 // an external symbol (either Value.SymbolName is set, or SymType is
1328 // Symbol::ST_Unknown) or if the target address is not within the
1329 // signed 24-bits branch address.
1330 SectionEntry &Section = Sections[SectionID];
1331 uint8_t *Target = Section.getAddressWithOffset(Offset);
1332 bool RangeOverflow = false;
1333 if (!Value.SymbolName && SymType != SymbolRef::ST_Unknown) {
1334 if (AbiVariant != 2) {
1335 // In the ELFv1 ABI, a function call may point to the .opd entry,
1336 // so the final symbol value is calculated based on the relocation
1337 // values in the .opd section.
1338 if (auto Err = findOPDEntrySection(Obj, ObjSectionToID, Value))
1339 return std::move(Err);
1341 // In the ELFv2 ABI, a function symbol may provide a local entry
1342 // point, which must be used for direct calls.
1343 uint8_t SymOther = Symbol->getOther();
1344 Value.Addend += ELF::decodePPC64LocalEntryOffset(SymOther);
1346 uint8_t *RelocTarget =
1347 Sections[Value.SectionID].getAddressWithOffset(Value.Addend);
1348 int64_t delta = static_cast<int64_t>(Target - RelocTarget);
1349 // If it is within 26-bits branch range, just set the branch target
1350 if (SignExtend64<26>(delta) == delta) {
1351 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1352 addRelocationForSection(RE, Value.SectionID);
1354 RangeOverflow = true;
1357 if (Value.SymbolName || SymType == SymbolRef::ST_Unknown ||
1359 // It is an external symbol (either Value.SymbolName is set, or
1360 // SymType is SymbolRef::ST_Unknown) or out of range.
1361 StubMap::const_iterator i = Stubs.find(Value);
1362 if (i != Stubs.end()) {
1363 // Symbol function stub already created, just relocate to it
1364 resolveRelocation(Section, Offset,
1365 reinterpret_cast<uint64_t>(
1366 Section.getAddressWithOffset(i->second)),
1368 DEBUG(dbgs() << " Stub function found\n");
1370 // Create a new stub function.
1371 DEBUG(dbgs() << " Create a new stub function\n");
1372 Stubs[Value] = Section.getStubOffset();
1373 uint8_t *StubTargetAddr = createStubFunction(
1374 Section.getAddressWithOffset(Section.getStubOffset()),
1376 RelocationEntry RE(SectionID, StubTargetAddr - Section.getAddress(),
1377 ELF::R_PPC64_ADDR64, Value.Addend);
1379 // Generates the 64-bits address loads as exemplified in section
1380 // 4.5.1 in PPC64 ELF ABI. Note that the relocations need to
1381 // apply to the low part of the instructions, so we have to update
1382 // the offset according to the target endianness.
1383 uint64_t StubRelocOffset = StubTargetAddr - Section.getAddress();
1384 if (!IsTargetLittleEndian)
1385 StubRelocOffset += 2;
1387 RelocationEntry REhst(SectionID, StubRelocOffset + 0,
1388 ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend);
1389 RelocationEntry REhr(SectionID, StubRelocOffset + 4,
1390 ELF::R_PPC64_ADDR16_HIGHER, Value.Addend);
1391 RelocationEntry REh(SectionID, StubRelocOffset + 12,
1392 ELF::R_PPC64_ADDR16_HI, Value.Addend);
1393 RelocationEntry REl(SectionID, StubRelocOffset + 16,
1394 ELF::R_PPC64_ADDR16_LO, Value.Addend);
1396 if (Value.SymbolName) {
1397 addRelocationForSymbol(REhst, Value.SymbolName);
1398 addRelocationForSymbol(REhr, Value.SymbolName);
1399 addRelocationForSymbol(REh, Value.SymbolName);
1400 addRelocationForSymbol(REl, Value.SymbolName);
1402 addRelocationForSection(REhst, Value.SectionID);
1403 addRelocationForSection(REhr, Value.SectionID);
1404 addRelocationForSection(REh, Value.SectionID);
1405 addRelocationForSection(REl, Value.SectionID);
1408 resolveRelocation(Section, Offset, reinterpret_cast<uint64_t>(
1409 Section.getAddressWithOffset(
1410 Section.getStubOffset())),
1412 Section.advanceStubOffset(getMaxStubSize());
1414 if (Value.SymbolName || SymType == SymbolRef::ST_Unknown) {
1415 // Restore the TOC for external calls
1416 if (AbiVariant == 2)
1417 writeInt32BE(Target + 4, 0xE8410018); // ld r2,28(r1)
1419 writeInt32BE(Target + 4, 0xE8410028); // ld r2,40(r1)
1422 } else if (RelType == ELF::R_PPC64_TOC16 ||
1423 RelType == ELF::R_PPC64_TOC16_DS ||
1424 RelType == ELF::R_PPC64_TOC16_LO ||
1425 RelType == ELF::R_PPC64_TOC16_LO_DS ||
1426 RelType == ELF::R_PPC64_TOC16_HI ||
1427 RelType == ELF::R_PPC64_TOC16_HA) {
1428 // These relocations are supposed to subtract the TOC address from
1429 // the final value. This does not fit cleanly into the RuntimeDyld
1430 // scheme, since there may be *two* sections involved in determining
1431 // the relocation value (the section of the symbol referred to by the
1432 // relocation, and the TOC section associated with the current module).
1434 // Fortunately, these relocations are currently only ever generated
1435 // referring to symbols that themselves reside in the TOC, which means
1436 // that the two sections are actually the same. Thus they cancel out
1437 // and we can immediately resolve the relocation right now.
1439 case ELF::R_PPC64_TOC16: RelType = ELF::R_PPC64_ADDR16; break;
1440 case ELF::R_PPC64_TOC16_DS: RelType = ELF::R_PPC64_ADDR16_DS; break;
1441 case ELF::R_PPC64_TOC16_LO: RelType = ELF::R_PPC64_ADDR16_LO; break;
1442 case ELF::R_PPC64_TOC16_LO_DS: RelType = ELF::R_PPC64_ADDR16_LO_DS; break;
1443 case ELF::R_PPC64_TOC16_HI: RelType = ELF::R_PPC64_ADDR16_HI; break;
1444 case ELF::R_PPC64_TOC16_HA: RelType = ELF::R_PPC64_ADDR16_HA; break;
1445 default: llvm_unreachable("Wrong relocation type.");
1448 RelocationValueRef TOCValue;
1449 if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, TOCValue))
1450 return std::move(Err);
1451 if (Value.SymbolName || Value.SectionID != TOCValue.SectionID)
1452 llvm_unreachable("Unsupported TOC relocation.");
1453 Value.Addend -= TOCValue.Addend;
1454 resolveRelocation(Sections[SectionID], Offset, Value.Addend, RelType, 0);
1456 // There are two ways to refer to the TOC address directly: either
1457 // via a ELF::R_PPC64_TOC relocation (where both symbol and addend are
1458 // ignored), or via any relocation that refers to the magic ".TOC."
1459 // symbols (in which case the addend is respected).
1460 if (RelType == ELF::R_PPC64_TOC) {
1461 RelType = ELF::R_PPC64_ADDR64;
1462 if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, Value))
1463 return std::move(Err);
1464 } else if (TargetName == ".TOC.") {
1465 if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, Value))
1466 return std::move(Err);
1467 Value.Addend += Addend;
1470 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1472 if (Value.SymbolName)
1473 addRelocationForSymbol(RE, Value.SymbolName);
1475 addRelocationForSection(RE, Value.SectionID);
1477 } else if (Arch == Triple::systemz &&
1478 (RelType == ELF::R_390_PLT32DBL || RelType == ELF::R_390_GOTENT)) {
1479 // Create function stubs for both PLT and GOT references, regardless of
1480 // whether the GOT reference is to data or code. The stub contains the
1481 // full address of the symbol, as needed by GOT references, and the
1482 // executable part only adds an overhead of 8 bytes.
1484 // We could try to conserve space by allocating the code and data
1485 // parts of the stub separately. However, as things stand, we allocate
1486 // a stub for every relocation, so using a GOT in JIT code should be
1487 // no less space efficient than using an explicit constant pool.
1488 DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation.");
1489 SectionEntry &Section = Sections[SectionID];
1491 // Look for an existing stub.
1492 StubMap::const_iterator i = Stubs.find(Value);
1493 uintptr_t StubAddress;
1494 if (i != Stubs.end()) {
1495 StubAddress = uintptr_t(Section.getAddressWithOffset(i->second));
1496 DEBUG(dbgs() << " Stub function found\n");
1498 // Create a new stub function.
1499 DEBUG(dbgs() << " Create a new stub function\n");
1501 uintptr_t BaseAddress = uintptr_t(Section.getAddress());
1502 uintptr_t StubAlignment = getStubAlignment();
1504 (BaseAddress + Section.getStubOffset() + StubAlignment - 1) &
1506 unsigned StubOffset = StubAddress - BaseAddress;
1508 Stubs[Value] = StubOffset;
1509 createStubFunction((uint8_t *)StubAddress);
1510 RelocationEntry RE(SectionID, StubOffset + 8, ELF::R_390_64,
1512 if (Value.SymbolName)
1513 addRelocationForSymbol(RE, Value.SymbolName);
1515 addRelocationForSection(RE, Value.SectionID);
1516 Section.advanceStubOffset(getMaxStubSize());
1519 if (RelType == ELF::R_390_GOTENT)
1520 resolveRelocation(Section, Offset, StubAddress + 8, ELF::R_390_PC32DBL,
1523 resolveRelocation(Section, Offset, StubAddress, RelType, Addend);
1524 } else if (Arch == Triple::x86_64) {
1525 if (RelType == ELF::R_X86_64_PLT32) {
1526 // The way the PLT relocations normally work is that the linker allocates
1528 // PLT and this relocation makes a PC-relative call into the PLT. The PLT
1529 // entry will then jump to an address provided by the GOT. On first call,
1531 // GOT address will point back into PLT code that resolves the symbol. After
1532 // the first call, the GOT entry points to the actual function.
1534 // For local functions we're ignoring all of that here and just replacing
1535 // the PLT32 relocation type with PC32, which will translate the relocation
1536 // into a PC-relative call directly to the function. For external symbols we
1537 // can't be sure the function will be within 2^32 bytes of the call site, so
1538 // we need to create a stub, which calls into the GOT. This case is
1539 // equivalent to the usual PLT implementation except that we use the stub
1540 // mechanism in RuntimeDyld (which puts stubs at the end of the section)
1541 // rather than allocating a PLT section.
1542 if (Value.SymbolName) {
1543 // This is a call to an external function.
1544 // Look for an existing stub.
1545 SectionEntry &Section = Sections[SectionID];
1546 StubMap::const_iterator i = Stubs.find(Value);
1547 uintptr_t StubAddress;
1548 if (i != Stubs.end()) {
1549 StubAddress = uintptr_t(Section.getAddress()) + i->second;
1550 DEBUG(dbgs() << " Stub function found\n");
1552 // Create a new stub function (equivalent to a PLT entry).
1553 DEBUG(dbgs() << " Create a new stub function\n");
1555 uintptr_t BaseAddress = uintptr_t(Section.getAddress());
1556 uintptr_t StubAlignment = getStubAlignment();
1558 (BaseAddress + Section.getStubOffset() + StubAlignment - 1) &
1560 unsigned StubOffset = StubAddress - BaseAddress;
1561 Stubs[Value] = StubOffset;
1562 createStubFunction((uint8_t *)StubAddress);
1564 // Bump our stub offset counter
1565 Section.advanceStubOffset(getMaxStubSize());
1567 // Allocate a GOT Entry
1568 uint64_t GOTOffset = allocateGOTEntries(1);
1570 // The load of the GOT address has an addend of -4
1571 resolveGOTOffsetRelocation(SectionID, StubOffset + 2, GOTOffset - 4,
1572 ELF::R_X86_64_PC32);
1574 // Fill in the value of the symbol we're targeting into the GOT
1575 addRelocationForSymbol(
1576 computeGOTOffsetRE(GOTOffset, 0, ELF::R_X86_64_64),
1580 // Make the target call a call into the stub table.
1581 resolveRelocation(Section, Offset, StubAddress, ELF::R_X86_64_PC32,
1584 RelocationEntry RE(SectionID, Offset, ELF::R_X86_64_PC32, Value.Addend,
1586 addRelocationForSection(RE, Value.SectionID);
1588 } else if (RelType == ELF::R_X86_64_GOTPCREL ||
1589 RelType == ELF::R_X86_64_GOTPCRELX ||
1590 RelType == ELF::R_X86_64_REX_GOTPCRELX) {
1591 uint64_t GOTOffset = allocateGOTEntries(1);
1592 resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend,
1593 ELF::R_X86_64_PC32);
1595 // Fill in the value of the symbol we're targeting into the GOT
1596 RelocationEntry RE =
1597 computeGOTOffsetRE(GOTOffset, Value.Offset, ELF::R_X86_64_64);
1598 if (Value.SymbolName)
1599 addRelocationForSymbol(RE, Value.SymbolName);
1601 addRelocationForSection(RE, Value.SectionID);
1602 } else if (RelType == ELF::R_X86_64_PC32) {
1603 Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset));
1604 processSimpleRelocation(SectionID, Offset, RelType, Value);
1605 } else if (RelType == ELF::R_X86_64_PC64) {
1606 Value.Addend += support::ulittle64_t::ref(computePlaceholderAddress(SectionID, Offset));
1607 processSimpleRelocation(SectionID, Offset, RelType, Value);
1609 processSimpleRelocation(SectionID, Offset, RelType, Value);
1612 if (Arch == Triple::x86) {
1613 Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset));
1615 processSimpleRelocation(SectionID, Offset, RelType, Value);
1620 size_t RuntimeDyldELF::getGOTEntrySize() {
1621 // We don't use the GOT in all of these cases, but it's essentially free
1622 // to put them all here.
1625 case Triple::x86_64:
1626 case Triple::aarch64:
1627 case Triple::aarch64_be:
1629 case Triple::ppc64le:
1630 case Triple::systemz:
1631 Result = sizeof(uint64_t);
1636 Result = sizeof(uint32_t);
1639 case Triple::mipsel:
1640 case Triple::mips64:
1641 case Triple::mips64el:
1642 if (IsMipsO32ABI || IsMipsN32ABI)
1643 Result = sizeof(uint32_t);
1644 else if (IsMipsN64ABI)
1645 Result = sizeof(uint64_t);
1647 llvm_unreachable("Mips ABI not handled");
1650 llvm_unreachable("Unsupported CPU type!");
1655 uint64_t RuntimeDyldELF::allocateGOTEntries(unsigned no) {
1656 if (GOTSectionID == 0) {
1657 GOTSectionID = Sections.size();
1658 // Reserve a section id. We'll allocate the section later
1659 // once we know the total size
1660 Sections.push_back(SectionEntry(".got", nullptr, 0, 0, 0));
1662 uint64_t StartOffset = CurrentGOTIndex * getGOTEntrySize();
1663 CurrentGOTIndex += no;
1667 uint64_t RuntimeDyldELF::findOrAllocGOTEntry(const RelocationValueRef &Value,
1668 unsigned GOTRelType) {
1669 auto E = GOTOffsetMap.insert({Value, 0});
1671 uint64_t GOTOffset = allocateGOTEntries(1);
1673 // Create relocation for newly created GOT entry
1674 RelocationEntry RE =
1675 computeGOTOffsetRE(GOTOffset, Value.Offset, GOTRelType);
1676 if (Value.SymbolName)
1677 addRelocationForSymbol(RE, Value.SymbolName);
1679 addRelocationForSection(RE, Value.SectionID);
1681 E.first->second = GOTOffset;
1684 return E.first->second;
1687 void RuntimeDyldELF::resolveGOTOffsetRelocation(unsigned SectionID,
1691 // Fill in the relative address of the GOT Entry into the stub
1692 RelocationEntry GOTRE(SectionID, Offset, Type, GOTOffset);
1693 addRelocationForSection(GOTRE, GOTSectionID);
1696 RelocationEntry RuntimeDyldELF::computeGOTOffsetRE(uint64_t GOTOffset,
1697 uint64_t SymbolOffset,
1699 return RelocationEntry(GOTSectionID, GOTOffset, Type, SymbolOffset);
1702 Error RuntimeDyldELF::finalizeLoad(const ObjectFile &Obj,
1703 ObjSectionToIDMap &SectionMap) {
1705 if (!PendingRelocs.empty())
1706 return make_error<RuntimeDyldError>("Can't find matching LO16 reloc");
1708 // If necessary, allocate the global offset table
1709 if (GOTSectionID != 0) {
1710 // Allocate memory for the section
1711 size_t TotalSize = CurrentGOTIndex * getGOTEntrySize();
1712 uint8_t *Addr = MemMgr.allocateDataSection(TotalSize, getGOTEntrySize(),
1713 GOTSectionID, ".got", false);
1715 return make_error<RuntimeDyldError>("Unable to allocate memory for GOT!");
1717 Sections[GOTSectionID] =
1718 SectionEntry(".got", Addr, TotalSize, TotalSize, 0);
1721 Checker->registerSection(Obj.getFileName(), GOTSectionID);
1723 // For now, initialize all GOT entries to zero. We'll fill them in as
1724 // needed when GOT-based relocations are applied.
1725 memset(Addr, 0, TotalSize);
1726 if (IsMipsN32ABI || IsMipsN64ABI) {
1727 // To correctly resolve Mips GOT relocations, we need a mapping from
1728 // object's sections to GOTs.
1729 for (section_iterator SI = Obj.section_begin(), SE = Obj.section_end();
1731 if (SI->relocation_begin() != SI->relocation_end()) {
1732 section_iterator RelocatedSection = SI->getRelocatedSection();
1733 ObjSectionToIDMap::iterator i = SectionMap.find(*RelocatedSection);
1734 assert (i != SectionMap.end());
1735 SectionToGOTMap[i->second] = GOTSectionID;
1738 GOTSymbolOffsets.clear();
1742 // Look for and record the EH frame section.
1743 ObjSectionToIDMap::iterator i, e;
1744 for (i = SectionMap.begin(), e = SectionMap.end(); i != e; ++i) {
1745 const SectionRef &Section = i->first;
1747 Section.getName(Name);
1748 if (Name == ".eh_frame") {
1749 UnregisteredEHFrameSections.push_back(i->second);
1755 CurrentGOTIndex = 0;
1757 return Error::success();
1760 bool RuntimeDyldELF::isCompatibleFile(const object::ObjectFile &Obj) const {
1764 bool RuntimeDyldELF::relocationNeedsGot(const RelocationRef &R) const {
1765 unsigned RelTy = R.getType();
1766 if (Arch == Triple::aarch64 || Arch == Triple::aarch64_be)
1767 return RelTy == ELF::R_AARCH64_ADR_GOT_PAGE ||
1768 RelTy == ELF::R_AARCH64_LD64_GOT_LO12_NC;
1770 if (Arch == Triple::x86_64)
1771 return RelTy == ELF::R_X86_64_GOTPCREL ||
1772 RelTy == ELF::R_X86_64_GOTPCRELX ||
1773 RelTy == ELF::R_X86_64_REX_GOTPCRELX;
1777 bool RuntimeDyldELF::relocationNeedsStub(const RelocationRef &R) const {
1778 if (Arch != Triple::x86_64)
1779 return true; // Conservative answer
1781 switch (R.getType()) {
1783 return true; // Conservative answer
1786 case ELF::R_X86_64_GOTPCREL:
1787 case ELF::R_X86_64_GOTPCRELX:
1788 case ELF::R_X86_64_REX_GOTPCRELX:
1789 case ELF::R_X86_64_PC32:
1790 case ELF::R_X86_64_PC64:
1791 case ELF::R_X86_64_64:
1792 // We know that these reloation types won't need a stub function. This list
1793 // can be extended as needed.