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);
224 RegisteredEHFrameSections.push_back(EHFrameSID);
226 UnregisteredEHFrameSections.clear();
229 void RuntimeDyldELF::deregisterEHFrames() {
230 for (int i = 0, e = RegisteredEHFrameSections.size(); i != e; ++i) {
231 SID EHFrameSID = RegisteredEHFrameSections[i];
232 uint8_t *EHFrameAddr = Sections[EHFrameSID].getAddress();
233 uint64_t EHFrameLoadAddr = Sections[EHFrameSID].getLoadAddress();
234 size_t EHFrameSize = Sections[EHFrameSID].getSize();
235 MemMgr.deregisterEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
237 RegisteredEHFrameSections.clear();
240 std::unique_ptr<RuntimeDyldELF>
241 llvm::RuntimeDyldELF::create(Triple::ArchType Arch,
242 RuntimeDyld::MemoryManager &MemMgr,
243 JITSymbolResolver &Resolver) {
246 return make_unique<RuntimeDyldELF>(MemMgr, Resolver);
250 case Triple::mips64el:
251 return make_unique<RuntimeDyldELFMips>(MemMgr, Resolver);
255 std::unique_ptr<RuntimeDyld::LoadedObjectInfo>
256 RuntimeDyldELF::loadObject(const object::ObjectFile &O) {
257 if (auto ObjSectionToIDOrErr = loadObjectImpl(O))
258 return llvm::make_unique<LoadedELFObjectInfo>(*this, *ObjSectionToIDOrErr);
261 raw_string_ostream ErrStream(ErrorStr);
262 logAllUnhandledErrors(ObjSectionToIDOrErr.takeError(), ErrStream, "");
267 void RuntimeDyldELF::resolveX86_64Relocation(const SectionEntry &Section,
268 uint64_t Offset, uint64_t Value,
269 uint32_t Type, int64_t Addend,
270 uint64_t SymOffset) {
273 llvm_unreachable("Relocation type not implemented yet!");
275 case ELF::R_X86_64_64: {
276 support::ulittle64_t::ref(Section.getAddressWithOffset(Offset)) =
278 DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend)) << " at "
279 << format("%p\n", Section.getAddressWithOffset(Offset)));
282 case ELF::R_X86_64_32:
283 case ELF::R_X86_64_32S: {
285 assert((Type == ELF::R_X86_64_32 && (Value <= UINT32_MAX)) ||
286 (Type == ELF::R_X86_64_32S &&
287 ((int64_t)Value <= INT32_MAX && (int64_t)Value >= INT32_MIN)));
288 uint32_t TruncatedAddr = (Value & 0xFFFFFFFF);
289 support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) =
291 DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr) << " at "
292 << format("%p\n", Section.getAddressWithOffset(Offset)));
295 case ELF::R_X86_64_PC8: {
296 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
297 int64_t RealOffset = Value + Addend - FinalAddress;
298 assert(isInt<8>(RealOffset));
299 int8_t TruncOffset = (RealOffset & 0xFF);
300 Section.getAddress()[Offset] = TruncOffset;
303 case ELF::R_X86_64_PC32: {
304 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
305 int64_t RealOffset = Value + Addend - FinalAddress;
306 assert(isInt<32>(RealOffset));
307 int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
308 support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) =
312 case ELF::R_X86_64_PC64: {
313 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
314 int64_t RealOffset = Value + Addend - FinalAddress;
315 support::ulittle64_t::ref(Section.getAddressWithOffset(Offset)) =
322 void RuntimeDyldELF::resolveX86Relocation(const SectionEntry &Section,
323 uint64_t Offset, uint32_t Value,
324 uint32_t Type, int32_t Addend) {
326 case ELF::R_386_32: {
327 support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) =
331 case ELF::R_386_PC32: {
332 uint32_t FinalAddress =
333 Section.getLoadAddressWithOffset(Offset) & 0xFFFFFFFF;
334 uint32_t RealOffset = Value + Addend - FinalAddress;
335 support::ulittle32_t::ref(Section.getAddressWithOffset(Offset)) =
340 // There are other relocation types, but it appears these are the
341 // only ones currently used by the LLVM ELF object writer
342 llvm_unreachable("Relocation type not implemented yet!");
347 void RuntimeDyldELF::resolveAArch64Relocation(const SectionEntry &Section,
348 uint64_t Offset, uint64_t Value,
349 uint32_t Type, int64_t Addend) {
350 uint32_t *TargetPtr =
351 reinterpret_cast<uint32_t *>(Section.getAddressWithOffset(Offset));
352 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
353 // Data should use target endian. Code should always use little endian.
354 bool isBE = Arch == Triple::aarch64_be;
356 DEBUG(dbgs() << "resolveAArch64Relocation, LocalAddress: 0x"
357 << format("%llx", Section.getAddressWithOffset(Offset))
358 << " FinalAddress: 0x" << format("%llx", FinalAddress)
359 << " Value: 0x" << format("%llx", Value) << " Type: 0x"
360 << format("%x", Type) << " Addend: 0x" << format("%llx", Addend)
365 llvm_unreachable("Relocation type not implemented yet!");
367 case ELF::R_AARCH64_ABS64:
368 write(isBE, TargetPtr, Value + Addend);
370 case ELF::R_AARCH64_PREL32: {
371 uint64_t Result = Value + Addend - FinalAddress;
372 assert(static_cast<int64_t>(Result) >= INT32_MIN &&
373 static_cast<int64_t>(Result) <= UINT32_MAX);
374 write(isBE, TargetPtr, static_cast<uint32_t>(Result & 0xffffffffU));
377 case ELF::R_AARCH64_CALL26: // fallthrough
378 case ELF::R_AARCH64_JUMP26: {
379 // Operation: S+A-P. Set Call or B immediate value to bits fff_fffc of the
381 uint64_t BranchImm = Value + Addend - FinalAddress;
383 // "Check that -2^27 <= result < 2^27".
384 assert(isInt<28>(BranchImm));
385 or32le(TargetPtr, (BranchImm & 0x0FFFFFFC) >> 2);
388 case ELF::R_AARCH64_MOVW_UABS_G3:
389 or32le(TargetPtr, ((Value + Addend) & 0xFFFF000000000000) >> 43);
391 case ELF::R_AARCH64_MOVW_UABS_G2_NC:
392 or32le(TargetPtr, ((Value + Addend) & 0xFFFF00000000) >> 27);
394 case ELF::R_AARCH64_MOVW_UABS_G1_NC:
395 or32le(TargetPtr, ((Value + Addend) & 0xFFFF0000) >> 11);
397 case ELF::R_AARCH64_MOVW_UABS_G0_NC:
398 or32le(TargetPtr, ((Value + Addend) & 0xFFFF) << 5);
400 case ELF::R_AARCH64_ADR_PREL_PG_HI21: {
401 // Operation: Page(S+A) - Page(P)
403 ((Value + Addend) & ~0xfffULL) - (FinalAddress & ~0xfffULL);
405 // Check that -2^32 <= X < 2^32
406 assert(isInt<33>(Result) && "overflow check failed for relocation");
408 // Immediate goes in bits 30:29 + 5:23 of ADRP instruction, taken
409 // from bits 32:12 of X.
410 write32AArch64Addr(TargetPtr, Result >> 12);
413 case ELF::R_AARCH64_ADD_ABS_LO12_NC:
415 // Immediate goes in bits 21:10 of LD/ST instruction, taken
416 // from bits 11:0 of X
417 or32AArch64Imm(TargetPtr, Value + Addend);
419 case ELF::R_AARCH64_LDST32_ABS_LO12_NC:
421 // Immediate goes in bits 21:10 of LD/ST instruction, taken
422 // from bits 11:2 of X
423 or32AArch64Imm(TargetPtr, getBits(Value + Addend, 2, 11));
425 case ELF::R_AARCH64_LDST64_ABS_LO12_NC:
427 // Immediate goes in bits 21:10 of LD/ST instruction, taken
428 // from bits 11:3 of X
429 or32AArch64Imm(TargetPtr, getBits(Value + Addend, 3, 11));
434 void RuntimeDyldELF::resolveARMRelocation(const SectionEntry &Section,
435 uint64_t Offset, uint32_t Value,
436 uint32_t Type, int32_t Addend) {
437 // TODO: Add Thumb relocations.
438 uint32_t *TargetPtr =
439 reinterpret_cast<uint32_t *>(Section.getAddressWithOffset(Offset));
440 uint32_t FinalAddress = Section.getLoadAddressWithOffset(Offset) & 0xFFFFFFFF;
443 DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: "
444 << Section.getAddressWithOffset(Offset)
445 << " FinalAddress: " << format("%p", FinalAddress) << " Value: "
446 << format("%x", Value) << " Type: " << format("%x", Type)
447 << " Addend: " << format("%x", Addend) << "\n");
451 llvm_unreachable("Not implemented relocation type!");
453 case ELF::R_ARM_NONE:
455 // Write a 31bit signed offset
456 case ELF::R_ARM_PREL31:
457 support::ulittle32_t::ref{TargetPtr} =
458 (support::ulittle32_t::ref{TargetPtr} & 0x80000000) |
459 ((Value - FinalAddress) & ~0x80000000);
461 case ELF::R_ARM_TARGET1:
462 case ELF::R_ARM_ABS32:
463 support::ulittle32_t::ref{TargetPtr} = Value;
465 // Write first 16 bit of 32 bit value to the mov instruction.
466 // Last 4 bit should be shifted.
467 case ELF::R_ARM_MOVW_ABS_NC:
468 case ELF::R_ARM_MOVT_ABS:
469 if (Type == ELF::R_ARM_MOVW_ABS_NC)
470 Value = Value & 0xFFFF;
471 else if (Type == ELF::R_ARM_MOVT_ABS)
472 Value = (Value >> 16) & 0xFFFF;
473 support::ulittle32_t::ref{TargetPtr} =
474 (support::ulittle32_t::ref{TargetPtr} & ~0x000F0FFF) | (Value & 0xFFF) |
475 (((Value >> 12) & 0xF) << 16);
477 // Write 24 bit relative value to the branch instruction.
478 case ELF::R_ARM_PC24: // Fall through.
479 case ELF::R_ARM_CALL: // Fall through.
480 case ELF::R_ARM_JUMP24:
481 int32_t RelValue = static_cast<int32_t>(Value - FinalAddress - 8);
482 RelValue = (RelValue & 0x03FFFFFC) >> 2;
483 assert((support::ulittle32_t::ref{TargetPtr} & 0xFFFFFF) == 0xFFFFFE);
484 support::ulittle32_t::ref{TargetPtr} =
485 (support::ulittle32_t::ref{TargetPtr} & 0xFF000000) | RelValue;
490 void RuntimeDyldELF::setMipsABI(const ObjectFile &Obj) {
491 if (Arch == Triple::UnknownArch ||
492 !StringRef(Triple::getArchTypePrefix(Arch)).equals("mips")) {
493 IsMipsO32ABI = false;
494 IsMipsN32ABI = false;
495 IsMipsN64ABI = false;
499 Obj.getPlatformFlags(AbiVariant);
500 IsMipsO32ABI = AbiVariant & ELF::EF_MIPS_ABI_O32;
501 IsMipsN32ABI = AbiVariant & ELF::EF_MIPS_ABI2;
502 IsMipsN64ABI = Obj.getFileFormatName().equals("ELF64-mips");
505 // Return the .TOC. section and offset.
506 Error RuntimeDyldELF::findPPC64TOCSection(const ELFObjectFileBase &Obj,
507 ObjSectionToIDMap &LocalSections,
508 RelocationValueRef &Rel) {
509 // Set a default SectionID in case we do not find a TOC section below.
510 // This may happen for references to TOC base base (sym@toc, .odp
511 // relocation) without a .toc directive. In this case just use the
512 // first section (which is usually the .odp) since the code won't
513 // reference the .toc base directly.
514 Rel.SymbolName = nullptr;
517 // The TOC consists of sections .got, .toc, .tocbss, .plt in that
518 // order. The TOC starts where the first of these sections starts.
519 for (auto &Section: Obj.sections()) {
520 StringRef SectionName;
521 if (auto EC = Section.getName(SectionName))
522 return errorCodeToError(EC);
524 if (SectionName == ".got"
525 || SectionName == ".toc"
526 || SectionName == ".tocbss"
527 || SectionName == ".plt") {
528 if (auto SectionIDOrErr =
529 findOrEmitSection(Obj, Section, false, LocalSections))
530 Rel.SectionID = *SectionIDOrErr;
532 return SectionIDOrErr.takeError();
537 // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000
538 // thus permitting a full 64 Kbytes segment.
541 return Error::success();
544 // Returns the sections and offset associated with the ODP entry referenced
546 Error RuntimeDyldELF::findOPDEntrySection(const ELFObjectFileBase &Obj,
547 ObjSectionToIDMap &LocalSections,
548 RelocationValueRef &Rel) {
549 // Get the ELF symbol value (st_value) to compare with Relocation offset in
551 for (section_iterator si = Obj.section_begin(), se = Obj.section_end();
553 section_iterator RelSecI = si->getRelocatedSection();
554 if (RelSecI == Obj.section_end())
557 StringRef RelSectionName;
558 if (auto EC = RelSecI->getName(RelSectionName))
559 return errorCodeToError(EC);
561 if (RelSectionName != ".opd")
564 for (elf_relocation_iterator i = si->relocation_begin(),
565 e = si->relocation_end();
567 // The R_PPC64_ADDR64 relocation indicates the first field
569 uint64_t TypeFunc = i->getType();
570 if (TypeFunc != ELF::R_PPC64_ADDR64) {
575 uint64_t TargetSymbolOffset = i->getOffset();
576 symbol_iterator TargetSymbol = i->getSymbol();
578 if (auto AddendOrErr = i->getAddend())
579 Addend = *AddendOrErr;
581 return errorCodeToError(AddendOrErr.getError());
587 // Just check if following relocation is a R_PPC64_TOC
588 uint64_t TypeTOC = i->getType();
589 if (TypeTOC != ELF::R_PPC64_TOC)
592 // Finally compares the Symbol value and the target symbol offset
593 // to check if this .opd entry refers to the symbol the relocation
595 if (Rel.Addend != (int64_t)TargetSymbolOffset)
598 section_iterator TSI = Obj.section_end();
599 if (auto TSIOrErr = TargetSymbol->getSection())
602 return TSIOrErr.takeError();
603 assert(TSI != Obj.section_end() && "TSI should refer to a valid section");
605 bool IsCode = TSI->isText();
606 if (auto SectionIDOrErr = findOrEmitSection(Obj, *TSI, IsCode,
608 Rel.SectionID = *SectionIDOrErr;
610 return SectionIDOrErr.takeError();
611 Rel.Addend = (intptr_t)Addend;
612 return Error::success();
615 llvm_unreachable("Attempting to get address of ODP entry!");
618 // Relocation masks following the #lo(value), #hi(value), #ha(value),
619 // #higher(value), #highera(value), #highest(value), and #highesta(value)
620 // macros defined in section 4.5.1. Relocation Types of the PPC-elf64abi
623 static inline uint16_t applyPPClo(uint64_t value) { return value & 0xffff; }
625 static inline uint16_t applyPPChi(uint64_t value) {
626 return (value >> 16) & 0xffff;
629 static inline uint16_t applyPPCha (uint64_t value) {
630 return ((value + 0x8000) >> 16) & 0xffff;
633 static inline uint16_t applyPPChigher(uint64_t value) {
634 return (value >> 32) & 0xffff;
637 static inline uint16_t applyPPChighera (uint64_t value) {
638 return ((value + 0x8000) >> 32) & 0xffff;
641 static inline uint16_t applyPPChighest(uint64_t value) {
642 return (value >> 48) & 0xffff;
645 static inline uint16_t applyPPChighesta (uint64_t value) {
646 return ((value + 0x8000) >> 48) & 0xffff;
649 void RuntimeDyldELF::resolvePPC32Relocation(const SectionEntry &Section,
650 uint64_t Offset, uint64_t Value,
651 uint32_t Type, int64_t Addend) {
652 uint8_t *LocalAddress = Section.getAddressWithOffset(Offset);
655 llvm_unreachable("Relocation type not implemented yet!");
657 case ELF::R_PPC_ADDR16_LO:
658 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
660 case ELF::R_PPC_ADDR16_HI:
661 writeInt16BE(LocalAddress, applyPPChi(Value + Addend));
663 case ELF::R_PPC_ADDR16_HA:
664 writeInt16BE(LocalAddress, applyPPCha(Value + Addend));
669 void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section,
670 uint64_t Offset, uint64_t Value,
671 uint32_t Type, int64_t Addend) {
672 uint8_t *LocalAddress = Section.getAddressWithOffset(Offset);
675 llvm_unreachable("Relocation type not implemented yet!");
677 case ELF::R_PPC64_ADDR16:
678 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
680 case ELF::R_PPC64_ADDR16_DS:
681 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
683 case ELF::R_PPC64_ADDR16_LO:
684 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
686 case ELF::R_PPC64_ADDR16_LO_DS:
687 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
689 case ELF::R_PPC64_ADDR16_HI:
690 writeInt16BE(LocalAddress, applyPPChi(Value + Addend));
692 case ELF::R_PPC64_ADDR16_HA:
693 writeInt16BE(LocalAddress, applyPPCha(Value + Addend));
695 case ELF::R_PPC64_ADDR16_HIGHER:
696 writeInt16BE(LocalAddress, applyPPChigher(Value + Addend));
698 case ELF::R_PPC64_ADDR16_HIGHERA:
699 writeInt16BE(LocalAddress, applyPPChighera(Value + Addend));
701 case ELF::R_PPC64_ADDR16_HIGHEST:
702 writeInt16BE(LocalAddress, applyPPChighest(Value + Addend));
704 case ELF::R_PPC64_ADDR16_HIGHESTA:
705 writeInt16BE(LocalAddress, applyPPChighesta(Value + Addend));
707 case ELF::R_PPC64_ADDR14: {
708 assert(((Value + Addend) & 3) == 0);
709 // Preserve the AA/LK bits in the branch instruction
710 uint8_t aalk = *(LocalAddress + 3);
711 writeInt16BE(LocalAddress + 2, (aalk & 3) | ((Value + Addend) & 0xfffc));
713 case ELF::R_PPC64_REL16_LO: {
714 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
715 uint64_t Delta = Value - FinalAddress + Addend;
716 writeInt16BE(LocalAddress, applyPPClo(Delta));
718 case ELF::R_PPC64_REL16_HI: {
719 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
720 uint64_t Delta = Value - FinalAddress + Addend;
721 writeInt16BE(LocalAddress, applyPPChi(Delta));
723 case ELF::R_PPC64_REL16_HA: {
724 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
725 uint64_t Delta = Value - FinalAddress + Addend;
726 writeInt16BE(LocalAddress, applyPPCha(Delta));
728 case ELF::R_PPC64_ADDR32: {
729 int32_t Result = static_cast<int32_t>(Value + Addend);
730 if (SignExtend32<32>(Result) != Result)
731 llvm_unreachable("Relocation R_PPC64_ADDR32 overflow");
732 writeInt32BE(LocalAddress, Result);
734 case ELF::R_PPC64_REL24: {
735 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
736 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
737 if (SignExtend32<26>(delta) != delta)
738 llvm_unreachable("Relocation R_PPC64_REL24 overflow");
739 // Generates a 'bl <address>' instruction
740 writeInt32BE(LocalAddress, 0x48000001 | (delta & 0x03FFFFFC));
742 case ELF::R_PPC64_REL32: {
743 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
744 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
745 if (SignExtend32<32>(delta) != delta)
746 llvm_unreachable("Relocation R_PPC64_REL32 overflow");
747 writeInt32BE(LocalAddress, delta);
749 case ELF::R_PPC64_REL64: {
750 uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
751 uint64_t Delta = Value - FinalAddress + Addend;
752 writeInt64BE(LocalAddress, Delta);
754 case ELF::R_PPC64_ADDR64:
755 writeInt64BE(LocalAddress, Value + Addend);
760 void RuntimeDyldELF::resolveSystemZRelocation(const SectionEntry &Section,
761 uint64_t Offset, uint64_t Value,
762 uint32_t Type, int64_t Addend) {
763 uint8_t *LocalAddress = Section.getAddressWithOffset(Offset);
766 llvm_unreachable("Relocation type not implemented yet!");
768 case ELF::R_390_PC16DBL:
769 case ELF::R_390_PLT16DBL: {
770 int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset);
771 assert(int16_t(Delta / 2) * 2 == Delta && "R_390_PC16DBL overflow");
772 writeInt16BE(LocalAddress, Delta / 2);
775 case ELF::R_390_PC32DBL:
776 case ELF::R_390_PLT32DBL: {
777 int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset);
778 assert(int32_t(Delta / 2) * 2 == Delta && "R_390_PC32DBL overflow");
779 writeInt32BE(LocalAddress, Delta / 2);
782 case ELF::R_390_PC32: {
783 int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset);
784 assert(int32_t(Delta) == Delta && "R_390_PC32 overflow");
785 writeInt32BE(LocalAddress, Delta);
789 writeInt64BE(LocalAddress, Value + Addend);
791 case ELF::R_390_PC64: {
792 int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset);
793 writeInt64BE(LocalAddress, Delta);
799 // The target location for the relocation is described by RE.SectionID and
800 // RE.Offset. RE.SectionID can be used to find the SectionEntry. Each
801 // SectionEntry has three members describing its location.
802 // SectionEntry::Address is the address at which the section has been loaded
803 // into memory in the current (host) process. SectionEntry::LoadAddress is the
804 // address that the section will have in the target process.
805 // SectionEntry::ObjAddress is the address of the bits for this section in the
806 // original emitted object image (also in the current address space).
808 // Relocations will be applied as if the section were loaded at
809 // SectionEntry::LoadAddress, but they will be applied at an address based
810 // on SectionEntry::Address. SectionEntry::ObjAddress will be used to refer to
811 // Target memory contents if they are required for value calculations.
813 // The Value parameter here is the load address of the symbol for the
814 // relocation to be applied. For relocations which refer to symbols in the
815 // current object Value will be the LoadAddress of the section in which
816 // the symbol resides (RE.Addend provides additional information about the
817 // symbol location). For external symbols, Value will be the address of the
818 // symbol in the target address space.
819 void RuntimeDyldELF::resolveRelocation(const RelocationEntry &RE,
821 const SectionEntry &Section = Sections[RE.SectionID];
822 return resolveRelocation(Section, RE.Offset, Value, RE.RelType, RE.Addend,
823 RE.SymOffset, RE.SectionID);
826 void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section,
827 uint64_t Offset, uint64_t Value,
828 uint32_t Type, int64_t Addend,
829 uint64_t SymOffset, SID SectionID) {
832 resolveX86_64Relocation(Section, Offset, Value, Type, Addend, SymOffset);
835 resolveX86Relocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
836 (uint32_t)(Addend & 0xffffffffL));
838 case Triple::aarch64:
839 case Triple::aarch64_be:
840 resolveAArch64Relocation(Section, Offset, Value, Type, Addend);
842 case Triple::arm: // Fall through.
845 case Triple::thumbeb:
846 resolveARMRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
847 (uint32_t)(Addend & 0xffffffffL));
850 resolvePPC32Relocation(Section, Offset, Value, Type, Addend);
852 case Triple::ppc64: // Fall through.
853 case Triple::ppc64le:
854 resolvePPC64Relocation(Section, Offset, Value, Type, Addend);
856 case Triple::systemz:
857 resolveSystemZRelocation(Section, Offset, Value, Type, Addend);
860 llvm_unreachable("Unsupported CPU type!");
864 void *RuntimeDyldELF::computePlaceholderAddress(unsigned SectionID, uint64_t Offset) const {
865 return (void *)(Sections[SectionID].getObjAddress() + Offset);
868 void RuntimeDyldELF::processSimpleRelocation(unsigned SectionID, uint64_t Offset, unsigned RelType, RelocationValueRef Value) {
869 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend, Value.Offset);
870 if (Value.SymbolName)
871 addRelocationForSymbol(RE, Value.SymbolName);
873 addRelocationForSection(RE, Value.SectionID);
876 uint32_t RuntimeDyldELF::getMatchingLoRelocation(uint32_t RelType,
877 bool IsLocal) const {
879 case ELF::R_MICROMIPS_GOT16:
881 return ELF::R_MICROMIPS_LO16;
883 case ELF::R_MICROMIPS_HI16:
884 return ELF::R_MICROMIPS_LO16;
885 case ELF::R_MIPS_GOT16:
887 return ELF::R_MIPS_LO16;
889 case ELF::R_MIPS_HI16:
890 return ELF::R_MIPS_LO16;
891 case ELF::R_MIPS_PCHI16:
892 return ELF::R_MIPS_PCLO16;
896 return ELF::R_MIPS_NONE;
899 // Sometimes we don't need to create thunk for a branch.
900 // This typically happens when branch target is located
901 // in the same object file. In such case target is either
902 // a weak symbol or symbol in a different executable section.
903 // This function checks if branch target is located in the
904 // same object file and if distance between source and target
905 // fits R_AARCH64_CALL26 relocation. If both conditions are
906 // met, it emits direct jump to the target and returns true.
907 // Otherwise false is returned and thunk is created.
908 bool RuntimeDyldELF::resolveAArch64ShortBranch(
909 unsigned SectionID, relocation_iterator RelI,
910 const RelocationValueRef &Value) {
912 if (Value.SymbolName) {
913 auto Loc = GlobalSymbolTable.find(Value.SymbolName);
915 // Don't create direct branch for external symbols.
916 if (Loc == GlobalSymbolTable.end())
919 const auto &SymInfo = Loc->second;
921 uint64_t(Sections[SymInfo.getSectionID()].getLoadAddressWithOffset(
922 SymInfo.getOffset()));
924 Address = uint64_t(Sections[Value.SectionID].getLoadAddress());
926 uint64_t Offset = RelI->getOffset();
927 uint64_t SourceAddress = Sections[SectionID].getLoadAddressWithOffset(Offset);
929 // R_AARCH64_CALL26 requires immediate to be in range -2^27 <= imm < 2^27
930 // If distance between source and target is out of range then we should
932 if (!isInt<28>(Address + Value.Addend - SourceAddress))
935 resolveRelocation(Sections[SectionID], Offset, Address, RelI->getType(),
941 Expected<relocation_iterator>
942 RuntimeDyldELF::processRelocationRef(
943 unsigned SectionID, relocation_iterator RelI, const ObjectFile &O,
944 ObjSectionToIDMap &ObjSectionToID, StubMap &Stubs) {
945 const auto &Obj = cast<ELFObjectFileBase>(O);
946 uint64_t RelType = RelI->getType();
947 ErrorOr<int64_t> AddendOrErr = ELFRelocationRef(*RelI).getAddend();
948 int64_t Addend = AddendOrErr ? *AddendOrErr : 0;
949 elf_symbol_iterator Symbol = RelI->getSymbol();
951 // Obtain the symbol name which is referenced in the relocation
952 StringRef TargetName;
953 if (Symbol != Obj.symbol_end()) {
954 if (auto TargetNameOrErr = Symbol->getName())
955 TargetName = *TargetNameOrErr;
957 return TargetNameOrErr.takeError();
959 DEBUG(dbgs() << "\t\tRelType: " << RelType << " Addend: " << Addend
960 << " TargetName: " << TargetName << "\n");
961 RelocationValueRef Value;
962 // First search for the symbol in the local symbol table
963 SymbolRef::Type SymType = SymbolRef::ST_Unknown;
965 // Search for the symbol in the global symbol table
966 RTDyldSymbolTable::const_iterator gsi = GlobalSymbolTable.end();
967 if (Symbol != Obj.symbol_end()) {
968 gsi = GlobalSymbolTable.find(TargetName.data());
969 Expected<SymbolRef::Type> SymTypeOrErr = Symbol->getType();
972 raw_string_ostream OS(Buf);
973 logAllUnhandledErrors(SymTypeOrErr.takeError(), OS, "");
975 report_fatal_error(Buf);
977 SymType = *SymTypeOrErr;
979 if (gsi != GlobalSymbolTable.end()) {
980 const auto &SymInfo = gsi->second;
981 Value.SectionID = SymInfo.getSectionID();
982 Value.Offset = SymInfo.getOffset();
983 Value.Addend = SymInfo.getOffset() + Addend;
986 case SymbolRef::ST_Debug: {
987 // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously
988 // and can be changed by another developers. Maybe best way is add
989 // a new symbol type ST_Section to SymbolRef and use it.
990 auto SectionOrErr = Symbol->getSection();
993 raw_string_ostream OS(Buf);
994 logAllUnhandledErrors(SectionOrErr.takeError(), OS, "");
996 report_fatal_error(Buf);
998 section_iterator si = *SectionOrErr;
999 if (si == Obj.section_end())
1000 llvm_unreachable("Symbol section not found, bad object file format!");
1001 DEBUG(dbgs() << "\t\tThis is section symbol\n");
1002 bool isCode = si->isText();
1003 if (auto SectionIDOrErr = findOrEmitSection(Obj, (*si), isCode,
1005 Value.SectionID = *SectionIDOrErr;
1007 return SectionIDOrErr.takeError();
1008 Value.Addend = Addend;
1011 case SymbolRef::ST_Data:
1012 case SymbolRef::ST_Function:
1013 case SymbolRef::ST_Unknown: {
1014 Value.SymbolName = TargetName.data();
1015 Value.Addend = Addend;
1017 // Absolute relocations will have a zero symbol ID (STN_UNDEF), which
1018 // will manifest here as a NULL symbol name.
1019 // We can set this as a valid (but empty) symbol name, and rely
1020 // on addRelocationForSymbol to handle this.
1021 if (!Value.SymbolName)
1022 Value.SymbolName = "";
1026 llvm_unreachable("Unresolved symbol type!");
1031 uint64_t Offset = RelI->getOffset();
1033 DEBUG(dbgs() << "\t\tSectionID: " << SectionID << " Offset: " << Offset
1035 if ((Arch == Triple::aarch64 || Arch == Triple::aarch64_be) &&
1036 (RelType == ELF::R_AARCH64_CALL26 || RelType == ELF::R_AARCH64_JUMP26)) {
1037 // This is an AArch64 branch relocation, need to use a stub function.
1038 DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation.");
1039 SectionEntry &Section = Sections[SectionID];
1041 // Look for an existing stub.
1042 StubMap::const_iterator i = Stubs.find(Value);
1043 if (i != Stubs.end()) {
1044 resolveRelocation(Section, Offset,
1045 (uint64_t)Section.getAddressWithOffset(i->second),
1047 DEBUG(dbgs() << " Stub function found\n");
1048 } else if (!resolveAArch64ShortBranch(SectionID, RelI, Value)) {
1049 // Create a new stub function.
1050 DEBUG(dbgs() << " Create a new stub function\n");
1051 Stubs[Value] = Section.getStubOffset();
1052 uint8_t *StubTargetAddr = createStubFunction(
1053 Section.getAddressWithOffset(Section.getStubOffset()));
1055 RelocationEntry REmovz_g3(SectionID,
1056 StubTargetAddr - Section.getAddress(),
1057 ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend);
1058 RelocationEntry REmovk_g2(SectionID, StubTargetAddr -
1059 Section.getAddress() + 4,
1060 ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend);
1061 RelocationEntry REmovk_g1(SectionID, StubTargetAddr -
1062 Section.getAddress() + 8,
1063 ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend);
1064 RelocationEntry REmovk_g0(SectionID, StubTargetAddr -
1065 Section.getAddress() + 12,
1066 ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend);
1068 if (Value.SymbolName) {
1069 addRelocationForSymbol(REmovz_g3, Value.SymbolName);
1070 addRelocationForSymbol(REmovk_g2, Value.SymbolName);
1071 addRelocationForSymbol(REmovk_g1, Value.SymbolName);
1072 addRelocationForSymbol(REmovk_g0, Value.SymbolName);
1074 addRelocationForSection(REmovz_g3, Value.SectionID);
1075 addRelocationForSection(REmovk_g2, Value.SectionID);
1076 addRelocationForSection(REmovk_g1, Value.SectionID);
1077 addRelocationForSection(REmovk_g0, Value.SectionID);
1079 resolveRelocation(Section, Offset,
1080 reinterpret_cast<uint64_t>(Section.getAddressWithOffset(
1081 Section.getStubOffset())),
1083 Section.advanceStubOffset(getMaxStubSize());
1085 } else if (Arch == Triple::arm) {
1086 if (RelType == ELF::R_ARM_PC24 || RelType == ELF::R_ARM_CALL ||
1087 RelType == ELF::R_ARM_JUMP24) {
1088 // This is an ARM branch relocation, need to use a stub function.
1089 DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.\n");
1090 SectionEntry &Section = Sections[SectionID];
1092 // Look for an existing stub.
1093 StubMap::const_iterator i = Stubs.find(Value);
1094 if (i != Stubs.end()) {
1097 reinterpret_cast<uint64_t>(Section.getAddressWithOffset(i->second)),
1099 DEBUG(dbgs() << " Stub function found\n");
1101 // Create a new stub function.
1102 DEBUG(dbgs() << " Create a new stub function\n");
1103 Stubs[Value] = Section.getStubOffset();
1104 uint8_t *StubTargetAddr = createStubFunction(
1105 Section.getAddressWithOffset(Section.getStubOffset()));
1106 RelocationEntry RE(SectionID, StubTargetAddr - Section.getAddress(),
1107 ELF::R_ARM_ABS32, Value.Addend);
1108 if (Value.SymbolName)
1109 addRelocationForSymbol(RE, Value.SymbolName);
1111 addRelocationForSection(RE, Value.SectionID);
1113 resolveRelocation(Section, Offset, reinterpret_cast<uint64_t>(
1114 Section.getAddressWithOffset(
1115 Section.getStubOffset())),
1117 Section.advanceStubOffset(getMaxStubSize());
1120 uint32_t *Placeholder =
1121 reinterpret_cast<uint32_t*>(computePlaceholderAddress(SectionID, Offset));
1122 if (RelType == ELF::R_ARM_PREL31 || RelType == ELF::R_ARM_TARGET1 ||
1123 RelType == ELF::R_ARM_ABS32) {
1124 Value.Addend += *Placeholder;
1125 } else if (RelType == ELF::R_ARM_MOVW_ABS_NC || RelType == ELF::R_ARM_MOVT_ABS) {
1126 // See ELF for ARM documentation
1127 Value.Addend += (int16_t)((*Placeholder & 0xFFF) | (((*Placeholder >> 16) & 0xF) << 12));
1129 processSimpleRelocation(SectionID, Offset, RelType, Value);
1131 } else if (IsMipsO32ABI) {
1132 uint8_t *Placeholder = reinterpret_cast<uint8_t *>(
1133 computePlaceholderAddress(SectionID, Offset));
1134 uint32_t Opcode = readBytesUnaligned(Placeholder, 4);
1135 if (RelType == ELF::R_MIPS_26) {
1136 // This is an Mips branch relocation, need to use a stub function.
1137 DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
1138 SectionEntry &Section = Sections[SectionID];
1140 // Extract the addend from the instruction.
1141 // We shift up by two since the Value will be down shifted again
1142 // when applying the relocation.
1143 uint32_t Addend = (Opcode & 0x03ffffff) << 2;
1145 Value.Addend += Addend;
1147 // Look up for existing stub.
1148 StubMap::const_iterator i = Stubs.find(Value);
1149 if (i != Stubs.end()) {
1150 RelocationEntry RE(SectionID, Offset, RelType, i->second);
1151 addRelocationForSection(RE, SectionID);
1152 DEBUG(dbgs() << " Stub function found\n");
1154 // Create a new stub function.
1155 DEBUG(dbgs() << " Create a new stub function\n");
1156 Stubs[Value] = Section.getStubOffset();
1158 unsigned AbiVariant;
1159 O.getPlatformFlags(AbiVariant);
1161 uint8_t *StubTargetAddr = createStubFunction(
1162 Section.getAddressWithOffset(Section.getStubOffset()), AbiVariant);
1164 // Creating Hi and Lo relocations for the filled stub instructions.
1165 RelocationEntry REHi(SectionID, StubTargetAddr - Section.getAddress(),
1166 ELF::R_MIPS_HI16, Value.Addend);
1167 RelocationEntry RELo(SectionID,
1168 StubTargetAddr - Section.getAddress() + 4,
1169 ELF::R_MIPS_LO16, Value.Addend);
1171 if (Value.SymbolName) {
1172 addRelocationForSymbol(REHi, Value.SymbolName);
1173 addRelocationForSymbol(RELo, Value.SymbolName);
1176 addRelocationForSection(REHi, Value.SectionID);
1177 addRelocationForSection(RELo, Value.SectionID);
1180 RelocationEntry RE(SectionID, Offset, RelType, Section.getStubOffset());
1181 addRelocationForSection(RE, SectionID);
1182 Section.advanceStubOffset(getMaxStubSize());
1184 } else if (RelType == ELF::R_MIPS_HI16 || RelType == ELF::R_MIPS_PCHI16) {
1185 int64_t Addend = (Opcode & 0x0000ffff) << 16;
1186 RelocationEntry RE(SectionID, Offset, RelType, Addend);
1187 PendingRelocs.push_back(std::make_pair(Value, RE));
1188 } else if (RelType == ELF::R_MIPS_LO16 || RelType == ELF::R_MIPS_PCLO16) {
1189 int64_t Addend = Value.Addend + SignExtend32<16>(Opcode & 0x0000ffff);
1190 for (auto I = PendingRelocs.begin(); I != PendingRelocs.end();) {
1191 const RelocationValueRef &MatchingValue = I->first;
1192 RelocationEntry &Reloc = I->second;
1193 if (MatchingValue == Value &&
1194 RelType == getMatchingLoRelocation(Reloc.RelType) &&
1195 SectionID == Reloc.SectionID) {
1196 Reloc.Addend += Addend;
1197 if (Value.SymbolName)
1198 addRelocationForSymbol(Reloc, Value.SymbolName);
1200 addRelocationForSection(Reloc, Value.SectionID);
1201 I = PendingRelocs.erase(I);
1205 RelocationEntry RE(SectionID, Offset, RelType, Addend);
1206 if (Value.SymbolName)
1207 addRelocationForSymbol(RE, Value.SymbolName);
1209 addRelocationForSection(RE, Value.SectionID);
1211 if (RelType == ELF::R_MIPS_32)
1212 Value.Addend += Opcode;
1213 else if (RelType == ELF::R_MIPS_PC16)
1214 Value.Addend += SignExtend32<18>((Opcode & 0x0000ffff) << 2);
1215 else if (RelType == ELF::R_MIPS_PC19_S2)
1216 Value.Addend += SignExtend32<21>((Opcode & 0x0007ffff) << 2);
1217 else if (RelType == ELF::R_MIPS_PC21_S2)
1218 Value.Addend += SignExtend32<23>((Opcode & 0x001fffff) << 2);
1219 else if (RelType == ELF::R_MIPS_PC26_S2)
1220 Value.Addend += SignExtend32<28>((Opcode & 0x03ffffff) << 2);
1221 processSimpleRelocation(SectionID, Offset, RelType, Value);
1223 } else if (IsMipsN32ABI || IsMipsN64ABI) {
1224 uint32_t r_type = RelType & 0xff;
1225 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1226 if (r_type == ELF::R_MIPS_CALL16 || r_type == ELF::R_MIPS_GOT_PAGE
1227 || r_type == ELF::R_MIPS_GOT_DISP) {
1228 StringMap<uint64_t>::iterator i = GOTSymbolOffsets.find(TargetName);
1229 if (i != GOTSymbolOffsets.end())
1230 RE.SymOffset = i->second;
1232 RE.SymOffset = allocateGOTEntries(SectionID, 1);
1233 GOTSymbolOffsets[TargetName] = RE.SymOffset;
1236 if (Value.SymbolName)
1237 addRelocationForSymbol(RE, Value.SymbolName);
1239 addRelocationForSection(RE, Value.SectionID);
1240 } else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) {
1241 if (RelType == ELF::R_PPC64_REL24) {
1242 // Determine ABI variant in use for this object.
1243 unsigned AbiVariant;
1244 Obj.getPlatformFlags(AbiVariant);
1245 AbiVariant &= ELF::EF_PPC64_ABI;
1246 // A PPC branch relocation will need a stub function if the target is
1247 // an external symbol (Symbol::ST_Unknown) or if the target address
1248 // is not within the signed 24-bits branch address.
1249 SectionEntry &Section = Sections[SectionID];
1250 uint8_t *Target = Section.getAddressWithOffset(Offset);
1251 bool RangeOverflow = false;
1252 if (SymType != SymbolRef::ST_Unknown) {
1253 if (AbiVariant != 2) {
1254 // In the ELFv1 ABI, a function call may point to the .opd entry,
1255 // so the final symbol value is calculated based on the relocation
1256 // values in the .opd section.
1257 if (auto Err = findOPDEntrySection(Obj, ObjSectionToID, Value))
1258 return std::move(Err);
1260 // In the ELFv2 ABI, a function symbol may provide a local entry
1261 // point, which must be used for direct calls.
1262 uint8_t SymOther = Symbol->getOther();
1263 Value.Addend += ELF::decodePPC64LocalEntryOffset(SymOther);
1265 uint8_t *RelocTarget =
1266 Sections[Value.SectionID].getAddressWithOffset(Value.Addend);
1267 int32_t delta = static_cast<int32_t>(Target - RelocTarget);
1268 // If it is within 26-bits branch range, just set the branch target
1269 if (SignExtend32<26>(delta) == delta) {
1270 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1271 if (Value.SymbolName)
1272 addRelocationForSymbol(RE, Value.SymbolName);
1274 addRelocationForSection(RE, Value.SectionID);
1276 RangeOverflow = true;
1279 if (SymType == SymbolRef::ST_Unknown || RangeOverflow) {
1280 // It is an external symbol (SymbolRef::ST_Unknown) or within a range
1281 // larger than 24-bits.
1282 StubMap::const_iterator i = Stubs.find(Value);
1283 if (i != Stubs.end()) {
1284 // Symbol function stub already created, just relocate to it
1285 resolveRelocation(Section, Offset,
1286 reinterpret_cast<uint64_t>(
1287 Section.getAddressWithOffset(i->second)),
1289 DEBUG(dbgs() << " Stub function found\n");
1291 // Create a new stub function.
1292 DEBUG(dbgs() << " Create a new stub function\n");
1293 Stubs[Value] = Section.getStubOffset();
1294 uint8_t *StubTargetAddr = createStubFunction(
1295 Section.getAddressWithOffset(Section.getStubOffset()),
1297 RelocationEntry RE(SectionID, StubTargetAddr - Section.getAddress(),
1298 ELF::R_PPC64_ADDR64, Value.Addend);
1300 // Generates the 64-bits address loads as exemplified in section
1301 // 4.5.1 in PPC64 ELF ABI. Note that the relocations need to
1302 // apply to the low part of the instructions, so we have to update
1303 // the offset according to the target endianness.
1304 uint64_t StubRelocOffset = StubTargetAddr - Section.getAddress();
1305 if (!IsTargetLittleEndian)
1306 StubRelocOffset += 2;
1308 RelocationEntry REhst(SectionID, StubRelocOffset + 0,
1309 ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend);
1310 RelocationEntry REhr(SectionID, StubRelocOffset + 4,
1311 ELF::R_PPC64_ADDR16_HIGHER, Value.Addend);
1312 RelocationEntry REh(SectionID, StubRelocOffset + 12,
1313 ELF::R_PPC64_ADDR16_HI, Value.Addend);
1314 RelocationEntry REl(SectionID, StubRelocOffset + 16,
1315 ELF::R_PPC64_ADDR16_LO, Value.Addend);
1317 if (Value.SymbolName) {
1318 addRelocationForSymbol(REhst, Value.SymbolName);
1319 addRelocationForSymbol(REhr, Value.SymbolName);
1320 addRelocationForSymbol(REh, Value.SymbolName);
1321 addRelocationForSymbol(REl, Value.SymbolName);
1323 addRelocationForSection(REhst, Value.SectionID);
1324 addRelocationForSection(REhr, Value.SectionID);
1325 addRelocationForSection(REh, Value.SectionID);
1326 addRelocationForSection(REl, Value.SectionID);
1329 resolveRelocation(Section, Offset, reinterpret_cast<uint64_t>(
1330 Section.getAddressWithOffset(
1331 Section.getStubOffset())),
1333 Section.advanceStubOffset(getMaxStubSize());
1335 if (SymType == SymbolRef::ST_Unknown) {
1336 // Restore the TOC for external calls
1337 if (AbiVariant == 2)
1338 writeInt32BE(Target + 4, 0xE8410018); // ld r2,28(r1)
1340 writeInt32BE(Target + 4, 0xE8410028); // ld r2,40(r1)
1343 } else if (RelType == ELF::R_PPC64_TOC16 ||
1344 RelType == ELF::R_PPC64_TOC16_DS ||
1345 RelType == ELF::R_PPC64_TOC16_LO ||
1346 RelType == ELF::R_PPC64_TOC16_LO_DS ||
1347 RelType == ELF::R_PPC64_TOC16_HI ||
1348 RelType == ELF::R_PPC64_TOC16_HA) {
1349 // These relocations are supposed to subtract the TOC address from
1350 // the final value. This does not fit cleanly into the RuntimeDyld
1351 // scheme, since there may be *two* sections involved in determining
1352 // the relocation value (the section of the symbol referred to by the
1353 // relocation, and the TOC section associated with the current module).
1355 // Fortunately, these relocations are currently only ever generated
1356 // referring to symbols that themselves reside in the TOC, which means
1357 // that the two sections are actually the same. Thus they cancel out
1358 // and we can immediately resolve the relocation right now.
1360 case ELF::R_PPC64_TOC16: RelType = ELF::R_PPC64_ADDR16; break;
1361 case ELF::R_PPC64_TOC16_DS: RelType = ELF::R_PPC64_ADDR16_DS; break;
1362 case ELF::R_PPC64_TOC16_LO: RelType = ELF::R_PPC64_ADDR16_LO; break;
1363 case ELF::R_PPC64_TOC16_LO_DS: RelType = ELF::R_PPC64_ADDR16_LO_DS; break;
1364 case ELF::R_PPC64_TOC16_HI: RelType = ELF::R_PPC64_ADDR16_HI; break;
1365 case ELF::R_PPC64_TOC16_HA: RelType = ELF::R_PPC64_ADDR16_HA; break;
1366 default: llvm_unreachable("Wrong relocation type.");
1369 RelocationValueRef TOCValue;
1370 if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, TOCValue))
1371 return std::move(Err);
1372 if (Value.SymbolName || Value.SectionID != TOCValue.SectionID)
1373 llvm_unreachable("Unsupported TOC relocation.");
1374 Value.Addend -= TOCValue.Addend;
1375 resolveRelocation(Sections[SectionID], Offset, Value.Addend, RelType, 0);
1377 // There are two ways to refer to the TOC address directly: either
1378 // via a ELF::R_PPC64_TOC relocation (where both symbol and addend are
1379 // ignored), or via any relocation that refers to the magic ".TOC."
1380 // symbols (in which case the addend is respected).
1381 if (RelType == ELF::R_PPC64_TOC) {
1382 RelType = ELF::R_PPC64_ADDR64;
1383 if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, Value))
1384 return std::move(Err);
1385 } else if (TargetName == ".TOC.") {
1386 if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, Value))
1387 return std::move(Err);
1388 Value.Addend += Addend;
1391 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1393 if (Value.SymbolName)
1394 addRelocationForSymbol(RE, Value.SymbolName);
1396 addRelocationForSection(RE, Value.SectionID);
1398 } else if (Arch == Triple::systemz &&
1399 (RelType == ELF::R_390_PLT32DBL || RelType == ELF::R_390_GOTENT)) {
1400 // Create function stubs for both PLT and GOT references, regardless of
1401 // whether the GOT reference is to data or code. The stub contains the
1402 // full address of the symbol, as needed by GOT references, and the
1403 // executable part only adds an overhead of 8 bytes.
1405 // We could try to conserve space by allocating the code and data
1406 // parts of the stub separately. However, as things stand, we allocate
1407 // a stub for every relocation, so using a GOT in JIT code should be
1408 // no less space efficient than using an explicit constant pool.
1409 DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation.");
1410 SectionEntry &Section = Sections[SectionID];
1412 // Look for an existing stub.
1413 StubMap::const_iterator i = Stubs.find(Value);
1414 uintptr_t StubAddress;
1415 if (i != Stubs.end()) {
1416 StubAddress = uintptr_t(Section.getAddressWithOffset(i->second));
1417 DEBUG(dbgs() << " Stub function found\n");
1419 // Create a new stub function.
1420 DEBUG(dbgs() << " Create a new stub function\n");
1422 uintptr_t BaseAddress = uintptr_t(Section.getAddress());
1423 uintptr_t StubAlignment = getStubAlignment();
1425 (BaseAddress + Section.getStubOffset() + StubAlignment - 1) &
1427 unsigned StubOffset = StubAddress - BaseAddress;
1429 Stubs[Value] = StubOffset;
1430 createStubFunction((uint8_t *)StubAddress);
1431 RelocationEntry RE(SectionID, StubOffset + 8, ELF::R_390_64,
1433 if (Value.SymbolName)
1434 addRelocationForSymbol(RE, Value.SymbolName);
1436 addRelocationForSection(RE, Value.SectionID);
1437 Section.advanceStubOffset(getMaxStubSize());
1440 if (RelType == ELF::R_390_GOTENT)
1441 resolveRelocation(Section, Offset, StubAddress + 8, ELF::R_390_PC32DBL,
1444 resolveRelocation(Section, Offset, StubAddress, RelType, Addend);
1445 } else if (Arch == Triple::x86_64) {
1446 if (RelType == ELF::R_X86_64_PLT32) {
1447 // The way the PLT relocations normally work is that the linker allocates
1449 // PLT and this relocation makes a PC-relative call into the PLT. The PLT
1450 // entry will then jump to an address provided by the GOT. On first call,
1452 // GOT address will point back into PLT code that resolves the symbol. After
1453 // the first call, the GOT entry points to the actual function.
1455 // For local functions we're ignoring all of that here and just replacing
1456 // the PLT32 relocation type with PC32, which will translate the relocation
1457 // into a PC-relative call directly to the function. For external symbols we
1458 // can't be sure the function will be within 2^32 bytes of the call site, so
1459 // we need to create a stub, which calls into the GOT. This case is
1460 // equivalent to the usual PLT implementation except that we use the stub
1461 // mechanism in RuntimeDyld (which puts stubs at the end of the section)
1462 // rather than allocating a PLT section.
1463 if (Value.SymbolName) {
1464 // This is a call to an external function.
1465 // Look for an existing stub.
1466 SectionEntry &Section = Sections[SectionID];
1467 StubMap::const_iterator i = Stubs.find(Value);
1468 uintptr_t StubAddress;
1469 if (i != Stubs.end()) {
1470 StubAddress = uintptr_t(Section.getAddress()) + i->second;
1471 DEBUG(dbgs() << " Stub function found\n");
1473 // Create a new stub function (equivalent to a PLT entry).
1474 DEBUG(dbgs() << " Create a new stub function\n");
1476 uintptr_t BaseAddress = uintptr_t(Section.getAddress());
1477 uintptr_t StubAlignment = getStubAlignment();
1479 (BaseAddress + Section.getStubOffset() + StubAlignment - 1) &
1481 unsigned StubOffset = StubAddress - BaseAddress;
1482 Stubs[Value] = StubOffset;
1483 createStubFunction((uint8_t *)StubAddress);
1485 // Bump our stub offset counter
1486 Section.advanceStubOffset(getMaxStubSize());
1488 // Allocate a GOT Entry
1489 uint64_t GOTOffset = allocateGOTEntries(SectionID, 1);
1491 // The load of the GOT address has an addend of -4
1492 resolveGOTOffsetRelocation(SectionID, StubOffset + 2, GOTOffset - 4);
1494 // Fill in the value of the symbol we're targeting into the GOT
1495 addRelocationForSymbol(
1496 computeGOTOffsetRE(SectionID, GOTOffset, 0, ELF::R_X86_64_64),
1500 // Make the target call a call into the stub table.
1501 resolveRelocation(Section, Offset, StubAddress, ELF::R_X86_64_PC32,
1504 RelocationEntry RE(SectionID, Offset, ELF::R_X86_64_PC32, Value.Addend,
1506 addRelocationForSection(RE, Value.SectionID);
1508 } else if (RelType == ELF::R_X86_64_GOTPCREL ||
1509 RelType == ELF::R_X86_64_GOTPCRELX ||
1510 RelType == ELF::R_X86_64_REX_GOTPCRELX) {
1511 uint64_t GOTOffset = allocateGOTEntries(SectionID, 1);
1512 resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend);
1514 // Fill in the value of the symbol we're targeting into the GOT
1515 RelocationEntry RE = computeGOTOffsetRE(SectionID, GOTOffset, Value.Offset, ELF::R_X86_64_64);
1516 if (Value.SymbolName)
1517 addRelocationForSymbol(RE, Value.SymbolName);
1519 addRelocationForSection(RE, Value.SectionID);
1520 } else if (RelType == ELF::R_X86_64_PC32) {
1521 Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset));
1522 processSimpleRelocation(SectionID, Offset, RelType, Value);
1523 } else if (RelType == ELF::R_X86_64_PC64) {
1524 Value.Addend += support::ulittle64_t::ref(computePlaceholderAddress(SectionID, Offset));
1525 processSimpleRelocation(SectionID, Offset, RelType, Value);
1527 processSimpleRelocation(SectionID, Offset, RelType, Value);
1530 if (Arch == Triple::x86) {
1531 Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset));
1533 processSimpleRelocation(SectionID, Offset, RelType, Value);
1538 size_t RuntimeDyldELF::getGOTEntrySize() {
1539 // We don't use the GOT in all of these cases, but it's essentially free
1540 // to put them all here.
1543 case Triple::x86_64:
1544 case Triple::aarch64:
1545 case Triple::aarch64_be:
1547 case Triple::ppc64le:
1548 case Triple::systemz:
1549 Result = sizeof(uint64_t);
1554 Result = sizeof(uint32_t);
1557 case Triple::mipsel:
1558 case Triple::mips64:
1559 case Triple::mips64el:
1560 if (IsMipsO32ABI || IsMipsN32ABI)
1561 Result = sizeof(uint32_t);
1562 else if (IsMipsN64ABI)
1563 Result = sizeof(uint64_t);
1565 llvm_unreachable("Mips ABI not handled");
1568 llvm_unreachable("Unsupported CPU type!");
1573 uint64_t RuntimeDyldELF::allocateGOTEntries(unsigned SectionID, unsigned no)
1575 (void)SectionID; // The GOT Section is the same for all section in the object file
1576 if (GOTSectionID == 0) {
1577 GOTSectionID = Sections.size();
1578 // Reserve a section id. We'll allocate the section later
1579 // once we know the total size
1580 Sections.push_back(SectionEntry(".got", nullptr, 0, 0, 0));
1582 uint64_t StartOffset = CurrentGOTIndex * getGOTEntrySize();
1583 CurrentGOTIndex += no;
1587 void RuntimeDyldELF::resolveGOTOffsetRelocation(unsigned SectionID, uint64_t Offset, uint64_t GOTOffset)
1589 // Fill in the relative address of the GOT Entry into the stub
1590 RelocationEntry GOTRE(SectionID, Offset, ELF::R_X86_64_PC32, GOTOffset);
1591 addRelocationForSection(GOTRE, GOTSectionID);
1594 RelocationEntry RuntimeDyldELF::computeGOTOffsetRE(unsigned SectionID, uint64_t GOTOffset, uint64_t SymbolOffset,
1597 (void)SectionID; // The GOT Section is the same for all section in the object file
1598 return RelocationEntry(GOTSectionID, GOTOffset, Type, SymbolOffset);
1601 Error RuntimeDyldELF::finalizeLoad(const ObjectFile &Obj,
1602 ObjSectionToIDMap &SectionMap) {
1604 if (!PendingRelocs.empty())
1605 return make_error<RuntimeDyldError>("Can't find matching LO16 reloc");
1607 // If necessary, allocate the global offset table
1608 if (GOTSectionID != 0) {
1609 // Allocate memory for the section
1610 size_t TotalSize = CurrentGOTIndex * getGOTEntrySize();
1611 uint8_t *Addr = MemMgr.allocateDataSection(TotalSize, getGOTEntrySize(),
1612 GOTSectionID, ".got", false);
1614 return make_error<RuntimeDyldError>("Unable to allocate memory for GOT!");
1616 Sections[GOTSectionID] =
1617 SectionEntry(".got", Addr, TotalSize, TotalSize, 0);
1620 Checker->registerSection(Obj.getFileName(), GOTSectionID);
1622 // For now, initialize all GOT entries to zero. We'll fill them in as
1623 // needed when GOT-based relocations are applied.
1624 memset(Addr, 0, TotalSize);
1625 if (IsMipsN32ABI || IsMipsN64ABI) {
1626 // To correctly resolve Mips GOT relocations, we need a mapping from
1627 // object's sections to GOTs.
1628 for (section_iterator SI = Obj.section_begin(), SE = Obj.section_end();
1630 if (SI->relocation_begin() != SI->relocation_end()) {
1631 section_iterator RelocatedSection = SI->getRelocatedSection();
1632 ObjSectionToIDMap::iterator i = SectionMap.find(*RelocatedSection);
1633 assert (i != SectionMap.end());
1634 SectionToGOTMap[i->second] = GOTSectionID;
1637 GOTSymbolOffsets.clear();
1641 // Look for and record the EH frame section.
1642 ObjSectionToIDMap::iterator i, e;
1643 for (i = SectionMap.begin(), e = SectionMap.end(); i != e; ++i) {
1644 const SectionRef &Section = i->first;
1646 Section.getName(Name);
1647 if (Name == ".eh_frame") {
1648 UnregisteredEHFrameSections.push_back(i->second);
1654 CurrentGOTIndex = 0;
1656 return Error::success();
1659 bool RuntimeDyldELF::isCompatibleFile(const object::ObjectFile &Obj) const {
1663 bool RuntimeDyldELF::relocationNeedsStub(const RelocationRef &R) const {
1664 if (Arch != Triple::x86_64)
1665 return true; // Conservative answer
1667 switch (R.getType()) {
1669 return true; // Conservative answer
1672 case ELF::R_X86_64_GOTPCREL:
1673 case ELF::R_X86_64_GOTPCRELX:
1674 case ELF::R_X86_64_REX_GOTPCRELX:
1675 case ELF::R_X86_64_PC32:
1676 case ELF::R_X86_64_PC64:
1677 case ELF::R_X86_64_64:
1678 // We know that these reloation types won't need a stub function. This list
1679 // can be extended as needed.