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 "llvm/ADT/IntervalMap.h"
17 #include "llvm/ADT/STLExtras.h"
18 #include "llvm/ADT/StringRef.h"
19 #include "llvm/ADT/Triple.h"
20 #include "llvm/MC/MCStreamer.h"
21 #include "llvm/Object/ELFObjectFile.h"
22 #include "llvm/Object/ObjectFile.h"
23 #include "llvm/Support/ELF.h"
24 #include "llvm/Support/Endian.h"
25 #include "llvm/Support/MemoryBuffer.h"
26 #include "llvm/Support/TargetRegistry.h"
29 using namespace llvm::object;
31 #define DEBUG_TYPE "dyld"
33 static inline std::error_code check(std::error_code Err) {
35 report_fatal_error(Err.message());
42 template <class ELFT> class DyldELFObject : public ELFObjectFile<ELFT> {
43 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
45 typedef Elf_Shdr_Impl<ELFT> Elf_Shdr;
46 typedef Elf_Sym_Impl<ELFT> Elf_Sym;
47 typedef Elf_Rel_Impl<ELFT, false> Elf_Rel;
48 typedef Elf_Rel_Impl<ELFT, true> Elf_Rela;
50 typedef Elf_Ehdr_Impl<ELFT> Elf_Ehdr;
52 typedef typename ELFDataTypeTypedefHelper<ELFT>::value_type addr_type;
55 DyldELFObject(MemoryBufferRef Wrapper, std::error_code &ec);
57 void updateSectionAddress(const SectionRef &Sec, uint64_t Addr);
59 void updateSymbolAddress(const SymbolRef &SymRef, uint64_t Addr);
61 // Methods for type inquiry through isa, cast and dyn_cast
62 static inline bool classof(const Binary *v) {
63 return (isa<ELFObjectFile<ELFT>>(v) &&
64 classof(cast<ELFObjectFile<ELFT>>(v)));
66 static inline bool classof(const ELFObjectFile<ELFT> *v) {
67 return v->isDyldType();
74 // The MemoryBuffer passed into this constructor is just a wrapper around the
75 // actual memory. Ultimately, the Binary parent class will take ownership of
76 // this MemoryBuffer object but not the underlying memory.
78 DyldELFObject<ELFT>::DyldELFObject(MemoryBufferRef Wrapper, std::error_code &EC)
79 : ELFObjectFile<ELFT>(Wrapper, EC) {
80 this->isDyldELFObject = true;
84 void DyldELFObject<ELFT>::updateSectionAddress(const SectionRef &Sec,
86 DataRefImpl ShdrRef = Sec.getRawDataRefImpl();
88 const_cast<Elf_Shdr *>(reinterpret_cast<const Elf_Shdr *>(ShdrRef.p));
90 // This assumes the address passed in matches the target address bitness
91 // The template-based type cast handles everything else.
92 shdr->sh_addr = static_cast<addr_type>(Addr);
96 void DyldELFObject<ELFT>::updateSymbolAddress(const SymbolRef &SymRef,
99 Elf_Sym *sym = const_cast<Elf_Sym *>(
100 ELFObjectFile<ELFT>::getSymbol(SymRef.getRawDataRefImpl()));
102 // This assumes the address passed in matches the target address bitness
103 // The template-based type cast handles everything else.
104 sym->st_value = static_cast<addr_type>(Addr);
107 class LoadedELFObjectInfo
108 : public RuntimeDyld::LoadedObjectInfoHelper<LoadedELFObjectInfo> {
110 LoadedELFObjectInfo(RuntimeDyldImpl &RTDyld, unsigned BeginIdx,
112 : LoadedObjectInfoHelper(RTDyld, BeginIdx, EndIdx) {}
114 OwningBinary<ObjectFile>
115 getObjectForDebug(const ObjectFile &Obj) const override;
118 template <typename ELFT>
119 std::unique_ptr<DyldELFObject<ELFT>>
120 createRTDyldELFObject(MemoryBufferRef Buffer,
121 const LoadedELFObjectInfo &L,
122 std::error_code &ec) {
123 typedef typename ELFFile<ELFT>::Elf_Shdr Elf_Shdr;
124 typedef typename ELFDataTypeTypedefHelper<ELFT>::value_type addr_type;
126 std::unique_ptr<DyldELFObject<ELFT>> Obj =
127 llvm::make_unique<DyldELFObject<ELFT>>(Buffer, ec);
129 // Iterate over all sections in the object.
130 for (const auto &Sec : Obj->sections()) {
131 StringRef SectionName;
132 Sec.getName(SectionName);
133 if (SectionName != "") {
134 DataRefImpl ShdrRef = Sec.getRawDataRefImpl();
135 Elf_Shdr *shdr = const_cast<Elf_Shdr *>(
136 reinterpret_cast<const Elf_Shdr *>(ShdrRef.p));
138 if (uint64_t SecLoadAddr = L.getSectionLoadAddress(SectionName)) {
139 // This assumes that the address passed in matches the target address
140 // bitness. The template-based type cast handles everything else.
141 shdr->sh_addr = static_cast<addr_type>(SecLoadAddr);
149 OwningBinary<ObjectFile> createELFDebugObject(const ObjectFile &Obj,
150 const LoadedELFObjectInfo &L) {
151 assert(Obj.isELF() && "Not an ELF object file.");
153 std::unique_ptr<MemoryBuffer> Buffer =
154 MemoryBuffer::getMemBufferCopy(Obj.getData(), Obj.getFileName());
158 std::unique_ptr<ObjectFile> DebugObj;
159 if (Obj.getBytesInAddress() == 4 && Obj.isLittleEndian()) {
160 typedef ELFType<support::little, false> ELF32LE;
161 DebugObj = createRTDyldELFObject<ELF32LE>(Buffer->getMemBufferRef(), L, ec);
162 } else if (Obj.getBytesInAddress() == 4 && !Obj.isLittleEndian()) {
163 typedef ELFType<support::big, false> ELF32BE;
164 DebugObj = createRTDyldELFObject<ELF32BE>(Buffer->getMemBufferRef(), L, ec);
165 } else if (Obj.getBytesInAddress() == 8 && !Obj.isLittleEndian()) {
166 typedef ELFType<support::big, true> ELF64BE;
167 DebugObj = createRTDyldELFObject<ELF64BE>(Buffer->getMemBufferRef(), L, ec);
168 } else if (Obj.getBytesInAddress() == 8 && Obj.isLittleEndian()) {
169 typedef ELFType<support::little, true> ELF64LE;
170 DebugObj = createRTDyldELFObject<ELF64LE>(Buffer->getMemBufferRef(), L, ec);
172 llvm_unreachable("Unexpected ELF format");
174 assert(!ec && "Could not construct copy ELF object file");
176 return OwningBinary<ObjectFile>(std::move(DebugObj), std::move(Buffer));
179 OwningBinary<ObjectFile>
180 LoadedELFObjectInfo::getObjectForDebug(const ObjectFile &Obj) const {
181 return createELFDebugObject(Obj, *this);
188 RuntimeDyldELF::RuntimeDyldELF(RuntimeDyld::MemoryManager &MemMgr,
189 RuntimeDyld::SymbolResolver &Resolver)
190 : RuntimeDyldImpl(MemMgr, Resolver), GOTSectionID(0), CurrentGOTIndex(0) {}
191 RuntimeDyldELF::~RuntimeDyldELF() {}
193 void RuntimeDyldELF::registerEHFrames() {
194 for (int i = 0, e = UnregisteredEHFrameSections.size(); i != e; ++i) {
195 SID EHFrameSID = UnregisteredEHFrameSections[i];
196 uint8_t *EHFrameAddr = Sections[EHFrameSID].Address;
197 uint64_t EHFrameLoadAddr = Sections[EHFrameSID].LoadAddress;
198 size_t EHFrameSize = Sections[EHFrameSID].Size;
199 MemMgr.registerEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
200 RegisteredEHFrameSections.push_back(EHFrameSID);
202 UnregisteredEHFrameSections.clear();
205 void RuntimeDyldELF::deregisterEHFrames() {
206 for (int i = 0, e = RegisteredEHFrameSections.size(); i != e; ++i) {
207 SID EHFrameSID = RegisteredEHFrameSections[i];
208 uint8_t *EHFrameAddr = Sections[EHFrameSID].Address;
209 uint64_t EHFrameLoadAddr = Sections[EHFrameSID].LoadAddress;
210 size_t EHFrameSize = Sections[EHFrameSID].Size;
211 MemMgr.deregisterEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
213 RegisteredEHFrameSections.clear();
216 std::unique_ptr<RuntimeDyld::LoadedObjectInfo>
217 RuntimeDyldELF::loadObject(const object::ObjectFile &O) {
218 unsigned SectionStartIdx, SectionEndIdx;
219 std::tie(SectionStartIdx, SectionEndIdx) = loadObjectImpl(O);
220 return llvm::make_unique<LoadedELFObjectInfo>(*this, SectionStartIdx,
224 void RuntimeDyldELF::resolveX86_64Relocation(const SectionEntry &Section,
225 uint64_t Offset, uint64_t Value,
226 uint32_t Type, int64_t Addend,
227 uint64_t SymOffset) {
230 llvm_unreachable("Relocation type not implemented yet!");
232 case ELF::R_X86_64_64: {
233 support::ulittle64_t::ref(Section.Address + Offset) = Value + Addend;
234 DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend)) << " at "
235 << format("%p\n", Section.Address + Offset));
238 case ELF::R_X86_64_32:
239 case ELF::R_X86_64_32S: {
241 assert((Type == ELF::R_X86_64_32 && (Value <= UINT32_MAX)) ||
242 (Type == ELF::R_X86_64_32S &&
243 ((int64_t)Value <= INT32_MAX && (int64_t)Value >= INT32_MIN)));
244 uint32_t TruncatedAddr = (Value & 0xFFFFFFFF);
245 support::ulittle32_t::ref(Section.Address + Offset) = TruncatedAddr;
246 DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr) << " at "
247 << format("%p\n", Section.Address + Offset));
250 case ELF::R_X86_64_PC32: {
251 uint64_t FinalAddress = Section.LoadAddress + Offset;
252 int64_t RealOffset = Value + Addend - FinalAddress;
253 assert(isInt<32>(RealOffset));
254 int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
255 support::ulittle32_t::ref(Section.Address + Offset) = TruncOffset;
258 case ELF::R_X86_64_PC64: {
259 uint64_t FinalAddress = Section.LoadAddress + Offset;
260 int64_t RealOffset = Value + Addend - FinalAddress;
261 support::ulittle64_t::ref(Section.Address + Offset) = RealOffset;
267 void RuntimeDyldELF::resolveX86Relocation(const SectionEntry &Section,
268 uint64_t Offset, uint32_t Value,
269 uint32_t Type, int32_t Addend) {
271 case ELF::R_386_32: {
272 support::ulittle32_t::ref(Section.Address + Offset) = Value + Addend;
275 case ELF::R_386_PC32: {
276 uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
277 uint32_t RealOffset = Value + Addend - FinalAddress;
278 support::ulittle32_t::ref(Section.Address + Offset) = RealOffset;
282 // There are other relocation types, but it appears these are the
283 // only ones currently used by the LLVM ELF object writer
284 llvm_unreachable("Relocation type not implemented yet!");
289 void RuntimeDyldELF::resolveAArch64Relocation(const SectionEntry &Section,
290 uint64_t Offset, uint64_t Value,
291 uint32_t Type, int64_t Addend) {
292 uint32_t *TargetPtr = reinterpret_cast<uint32_t *>(Section.Address + Offset);
293 uint64_t FinalAddress = Section.LoadAddress + Offset;
295 DEBUG(dbgs() << "resolveAArch64Relocation, LocalAddress: 0x"
296 << format("%llx", Section.Address + Offset)
297 << " FinalAddress: 0x" << format("%llx", FinalAddress)
298 << " Value: 0x" << format("%llx", Value) << " Type: 0x"
299 << format("%x", Type) << " Addend: 0x" << format("%llx", Addend)
304 llvm_unreachable("Relocation type not implemented yet!");
306 case ELF::R_AARCH64_ABS64: {
307 uint64_t *TargetPtr =
308 reinterpret_cast<uint64_t *>(Section.Address + Offset);
309 *TargetPtr = Value + Addend;
312 case ELF::R_AARCH64_PREL32: {
313 uint64_t Result = Value + Addend - FinalAddress;
314 assert(static_cast<int64_t>(Result) >= INT32_MIN &&
315 static_cast<int64_t>(Result) <= UINT32_MAX);
316 *TargetPtr = static_cast<uint32_t>(Result & 0xffffffffU);
319 case ELF::R_AARCH64_CALL26: // fallthrough
320 case ELF::R_AARCH64_JUMP26: {
321 // Operation: S+A-P. Set Call or B immediate value to bits fff_fffc of the
323 uint64_t BranchImm = Value + Addend - FinalAddress;
325 // "Check that -2^27 <= result < 2^27".
326 assert(isInt<28>(BranchImm));
328 // AArch64 code is emitted with .rela relocations. The data already in any
329 // bits affected by the relocation on entry is garbage.
330 *TargetPtr &= 0xfc000000U;
331 // Immediate goes in bits 25:0 of B and BL.
332 *TargetPtr |= static_cast<uint32_t>(BranchImm & 0xffffffcU) >> 2;
335 case ELF::R_AARCH64_MOVW_UABS_G3: {
336 uint64_t Result = Value + Addend;
338 // AArch64 code is emitted with .rela relocations. The data already in any
339 // bits affected by the relocation on entry is garbage.
340 *TargetPtr &= 0xffe0001fU;
341 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
342 *TargetPtr |= Result >> (48 - 5);
343 // Shift must be "lsl #48", in bits 22:21
344 assert((*TargetPtr >> 21 & 0x3) == 3 && "invalid shift for relocation");
347 case ELF::R_AARCH64_MOVW_UABS_G2_NC: {
348 uint64_t Result = Value + Addend;
350 // AArch64 code is emitted with .rela relocations. The data already in any
351 // bits affected by the relocation on entry is garbage.
352 *TargetPtr &= 0xffe0001fU;
353 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
354 *TargetPtr |= ((Result & 0xffff00000000ULL) >> (32 - 5));
355 // Shift must be "lsl #32", in bits 22:21
356 assert((*TargetPtr >> 21 & 0x3) == 2 && "invalid shift for relocation");
359 case ELF::R_AARCH64_MOVW_UABS_G1_NC: {
360 uint64_t Result = Value + Addend;
362 // AArch64 code is emitted with .rela relocations. The data already in any
363 // bits affected by the relocation on entry is garbage.
364 *TargetPtr &= 0xffe0001fU;
365 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
366 *TargetPtr |= ((Result & 0xffff0000U) >> (16 - 5));
367 // Shift must be "lsl #16", in bits 22:2
368 assert((*TargetPtr >> 21 & 0x3) == 1 && "invalid shift for relocation");
371 case ELF::R_AARCH64_MOVW_UABS_G0_NC: {
372 uint64_t Result = Value + Addend;
374 // AArch64 code is emitted with .rela relocations. The data already in any
375 // bits affected by the relocation on entry is garbage.
376 *TargetPtr &= 0xffe0001fU;
377 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
378 *TargetPtr |= ((Result & 0xffffU) << 5);
379 // Shift must be "lsl #0", in bits 22:21.
380 assert((*TargetPtr >> 21 & 0x3) == 0 && "invalid shift for relocation");
383 case ELF::R_AARCH64_ADR_PREL_PG_HI21: {
384 // Operation: Page(S+A) - Page(P)
386 ((Value + Addend) & ~0xfffULL) - (FinalAddress & ~0xfffULL);
388 // Check that -2^32 <= X < 2^32
389 assert(isInt<33>(Result) && "overflow check failed for relocation");
391 // AArch64 code is emitted with .rela relocations. The data already in any
392 // bits affected by the relocation on entry is garbage.
393 *TargetPtr &= 0x9f00001fU;
394 // Immediate goes in bits 30:29 + 5:23 of ADRP instruction, taken
395 // from bits 32:12 of X.
396 *TargetPtr |= ((Result & 0x3000U) << (29 - 12));
397 *TargetPtr |= ((Result & 0x1ffffc000ULL) >> (14 - 5));
400 case ELF::R_AARCH64_LDST32_ABS_LO12_NC: {
402 uint64_t Result = Value + Addend;
404 // AArch64 code is emitted with .rela relocations. The data already in any
405 // bits affected by the relocation on entry is garbage.
406 *TargetPtr &= 0xffc003ffU;
407 // Immediate goes in bits 21:10 of LD/ST instruction, taken
408 // from bits 11:2 of X
409 *TargetPtr |= ((Result & 0xffc) << (10 - 2));
412 case ELF::R_AARCH64_LDST64_ABS_LO12_NC: {
414 uint64_t Result = Value + Addend;
416 // AArch64 code is emitted with .rela relocations. The data already in any
417 // bits affected by the relocation on entry is garbage.
418 *TargetPtr &= 0xffc003ffU;
419 // Immediate goes in bits 21:10 of LD/ST instruction, taken
420 // from bits 11:3 of X
421 *TargetPtr |= ((Result & 0xff8) << (10 - 3));
427 void RuntimeDyldELF::resolveARMRelocation(const SectionEntry &Section,
428 uint64_t Offset, uint32_t Value,
429 uint32_t Type, int32_t Addend) {
430 // TODO: Add Thumb relocations.
431 uint32_t *TargetPtr = (uint32_t *)(Section.Address + Offset);
432 uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
435 DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: "
436 << Section.Address + Offset
437 << " FinalAddress: " << format("%p", FinalAddress) << " Value: "
438 << format("%x", Value) << " Type: " << format("%x", Type)
439 << " Addend: " << format("%x", Addend) << "\n");
443 llvm_unreachable("Not implemented relocation type!");
445 case ELF::R_ARM_NONE:
447 case ELF::R_ARM_PREL31:
448 case ELF::R_ARM_TARGET1:
449 case ELF::R_ARM_ABS32:
452 // Write first 16 bit of 32 bit value to the mov instruction.
453 // Last 4 bit should be shifted.
454 case ELF::R_ARM_MOVW_ABS_NC:
455 case ELF::R_ARM_MOVT_ABS:
456 if (Type == ELF::R_ARM_MOVW_ABS_NC)
457 Value = Value & 0xFFFF;
458 else if (Type == ELF::R_ARM_MOVT_ABS)
459 Value = (Value >> 16) & 0xFFFF;
460 *TargetPtr &= ~0x000F0FFF;
461 *TargetPtr |= Value & 0xFFF;
462 *TargetPtr |= ((Value >> 12) & 0xF) << 16;
464 // Write 24 bit relative value to the branch instruction.
465 case ELF::R_ARM_PC24: // Fall through.
466 case ELF::R_ARM_CALL: // Fall through.
467 case ELF::R_ARM_JUMP24:
468 int32_t RelValue = static_cast<int32_t>(Value - FinalAddress - 8);
469 RelValue = (RelValue & 0x03FFFFFC) >> 2;
470 assert((*TargetPtr & 0xFFFFFF) == 0xFFFFFE);
471 *TargetPtr &= 0xFF000000;
472 *TargetPtr |= RelValue;
477 void RuntimeDyldELF::resolveMIPSRelocation(const SectionEntry &Section,
478 uint64_t Offset, uint32_t Value,
479 uint32_t Type, int32_t Addend) {
480 uint8_t *TargetPtr = Section.Address + Offset;
483 DEBUG(dbgs() << "resolveMIPSRelocation, LocalAddress: "
484 << Section.Address + Offset << " FinalAddress: "
485 << format("%p", Section.LoadAddress + Offset) << " Value: "
486 << format("%x", Value) << " Type: " << format("%x", Type)
487 << " Addend: " << format("%x", Addend) << "\n");
489 uint32_t Insn = readBytesUnaligned(TargetPtr, 4);
493 llvm_unreachable("Not implemented relocation type!");
496 writeBytesUnaligned(Value, TargetPtr, 4);
500 Insn |= (Value & 0x0fffffff) >> 2;
501 writeBytesUnaligned(Insn, TargetPtr, 4);
503 case ELF::R_MIPS_HI16:
504 // Get the higher 16-bits. Also add 1 if bit 15 is 1.
506 Insn |= ((Value + 0x8000) >> 16) & 0xffff;
507 writeBytesUnaligned(Insn, TargetPtr, 4);
509 case ELF::R_MIPS_LO16:
511 Insn |= Value & 0xffff;
512 writeBytesUnaligned(Insn, TargetPtr, 4);
514 case ELF::R_MIPS_PC32: {
515 uint32_t FinalAddress = (Section.LoadAddress + Offset);
516 writeBytesUnaligned(Value - FinalAddress, (uint8_t *)TargetPtr, 4);
519 case ELF::R_MIPS_PC16: {
520 uint32_t FinalAddress = (Section.LoadAddress + Offset);
522 Insn |= ((Value - FinalAddress) >> 2) & 0xffff;
523 writeBytesUnaligned(Insn, TargetPtr, 4);
526 case ELF::R_MIPS_PC19_S2: {
527 uint32_t FinalAddress = (Section.LoadAddress + Offset);
529 Insn |= ((Value - (FinalAddress & ~0x3)) >> 2) & 0x7ffff;
530 writeBytesUnaligned(Insn, TargetPtr, 4);
533 case ELF::R_MIPS_PC21_S2: {
534 uint32_t FinalAddress = (Section.LoadAddress + Offset);
536 Insn |= ((Value - FinalAddress) >> 2) & 0x1fffff;
537 writeBytesUnaligned(Insn, TargetPtr, 4);
540 case ELF::R_MIPS_PC26_S2: {
541 uint32_t FinalAddress = (Section.LoadAddress + Offset);
543 Insn |= ((Value - FinalAddress) >> 2) & 0x3ffffff;
544 writeBytesUnaligned(Insn, TargetPtr, 4);
547 case ELF::R_MIPS_PCHI16: {
548 uint32_t FinalAddress = (Section.LoadAddress + Offset);
550 Insn |= ((Value - FinalAddress + 0x8000) >> 16) & 0xffff;
551 writeBytesUnaligned(Insn, TargetPtr, 4);
554 case ELF::R_MIPS_PCLO16: {
555 uint32_t FinalAddress = (Section.LoadAddress + Offset);
557 Insn |= (Value - FinalAddress) & 0xffff;
558 writeBytesUnaligned(Insn, TargetPtr, 4);
564 void RuntimeDyldELF::setMipsABI(const ObjectFile &Obj) {
565 if (Arch == Triple::UnknownArch ||
566 !StringRef(Triple::getArchTypePrefix(Arch)).equals("mips")) {
567 IsMipsO32ABI = false;
568 IsMipsN64ABI = false;
572 Obj.getPlatformFlags(AbiVariant);
573 IsMipsO32ABI = AbiVariant & ELF::EF_MIPS_ABI_O32;
574 IsMipsN64ABI = Obj.getFileFormatName().equals("ELF64-mips");
575 if (AbiVariant & ELF::EF_MIPS_ABI2)
576 llvm_unreachable("Mips N32 ABI is not supported yet");
579 void RuntimeDyldELF::resolveMIPS64Relocation(const SectionEntry &Section,
580 uint64_t Offset, uint64_t Value,
581 uint32_t Type, int64_t Addend,
584 uint32_t r_type = Type & 0xff;
585 uint32_t r_type2 = (Type >> 8) & 0xff;
586 uint32_t r_type3 = (Type >> 16) & 0xff;
588 // RelType is used to keep information for which relocation type we are
589 // applying relocation.
590 uint32_t RelType = r_type;
591 int64_t CalculatedValue = evaluateMIPS64Relocation(Section, Offset, Value,
593 SymOffset, SectionID);
594 if (r_type2 != ELF::R_MIPS_NONE) {
596 CalculatedValue = evaluateMIPS64Relocation(Section, Offset, 0, RelType,
597 CalculatedValue, SymOffset,
600 if (r_type3 != ELF::R_MIPS_NONE) {
602 CalculatedValue = evaluateMIPS64Relocation(Section, Offset, 0, RelType,
603 CalculatedValue, SymOffset,
606 applyMIPS64Relocation(Section.Address + Offset, CalculatedValue, RelType);
610 RuntimeDyldELF::evaluateMIPS64Relocation(const SectionEntry &Section,
611 uint64_t Offset, uint64_t Value,
612 uint32_t Type, int64_t Addend,
613 uint64_t SymOffset, SID SectionID) {
615 DEBUG(dbgs() << "evaluateMIPS64Relocation, LocalAddress: 0x"
616 << format("%llx", Section.Address + Offset)
617 << " FinalAddress: 0x"
618 << format("%llx", Section.LoadAddress + Offset)
619 << " Value: 0x" << format("%llx", Value) << " Type: 0x"
620 << format("%x", Type) << " Addend: 0x" << format("%llx", Addend)
621 << " SymOffset: " << format("%x", SymOffset)
626 llvm_unreachable("Not implemented relocation type!");
628 case ELF::R_MIPS_JALR:
629 case ELF::R_MIPS_NONE:
633 return Value + Addend;
635 return ((Value + Addend) >> 2) & 0x3ffffff;
636 case ELF::R_MIPS_GPREL16: {
637 uint64_t GOTAddr = getSectionLoadAddress(SectionToGOTMap[SectionID]);
638 return Value + Addend - (GOTAddr + 0x7ff0);
640 case ELF::R_MIPS_SUB:
641 return Value - Addend;
642 case ELF::R_MIPS_HI16:
643 // Get the higher 16-bits. Also add 1 if bit 15 is 1.
644 return ((Value + Addend + 0x8000) >> 16) & 0xffff;
645 case ELF::R_MIPS_LO16:
646 return (Value + Addend) & 0xffff;
647 case ELF::R_MIPS_CALL16:
648 case ELF::R_MIPS_GOT_DISP:
649 case ELF::R_MIPS_GOT_PAGE: {
650 uint8_t *LocalGOTAddr =
651 getSectionAddress(SectionToGOTMap[SectionID]) + SymOffset;
652 uint64_t GOTEntry = readBytesUnaligned(LocalGOTAddr, 8);
655 if (Type == ELF::R_MIPS_GOT_PAGE)
656 Value = (Value + 0x8000) & ~0xffff;
659 assert(GOTEntry == Value &&
660 "GOT entry has two different addresses.");
662 writeBytesUnaligned(Value, LocalGOTAddr, 8);
664 return (SymOffset - 0x7ff0) & 0xffff;
666 case ELF::R_MIPS_GOT_OFST: {
667 int64_t page = (Value + Addend + 0x8000) & ~0xffff;
668 return (Value + Addend - page) & 0xffff;
670 case ELF::R_MIPS_GPREL32: {
671 uint64_t GOTAddr = getSectionLoadAddress(SectionToGOTMap[SectionID]);
672 return Value + Addend - (GOTAddr + 0x7ff0);
674 case ELF::R_MIPS_PC16: {
675 uint64_t FinalAddress = (Section.LoadAddress + Offset);
676 return ((Value + Addend - FinalAddress) >> 2) & 0xffff;
678 case ELF::R_MIPS_PC32: {
679 uint64_t FinalAddress = (Section.LoadAddress + Offset);
680 return Value + Addend - FinalAddress;
682 case ELF::R_MIPS_PC18_S3: {
683 uint64_t FinalAddress = (Section.LoadAddress + Offset);
684 return ((Value + Addend - ((FinalAddress | 7) ^ 7)) >> 3) & 0x3ffff;
686 case ELF::R_MIPS_PC19_S2: {
687 uint64_t FinalAddress = (Section.LoadAddress + Offset);
688 return ((Value + Addend - FinalAddress) >> 2) & 0x7ffff;
690 case ELF::R_MIPS_PC21_S2: {
691 uint64_t FinalAddress = (Section.LoadAddress + Offset);
692 return ((Value + Addend - FinalAddress) >> 2) & 0x1fffff;
694 case ELF::R_MIPS_PC26_S2: {
695 uint64_t FinalAddress = (Section.LoadAddress + Offset);
696 return ((Value + Addend - FinalAddress) >> 2) & 0x3ffffff;
698 case ELF::R_MIPS_PCHI16: {
699 uint64_t FinalAddress = (Section.LoadAddress + Offset);
700 return ((Value + Addend - FinalAddress + 0x8000) >> 16) & 0xffff;
702 case ELF::R_MIPS_PCLO16: {
703 uint64_t FinalAddress = (Section.LoadAddress + Offset);
704 return (Value + Addend - FinalAddress) & 0xffff;
710 void RuntimeDyldELF::applyMIPS64Relocation(uint8_t *TargetPtr,
711 int64_t CalculatedValue,
713 uint32_t Insn = readBytesUnaligned(TargetPtr, 4);
719 case ELF::R_MIPS_GPREL32:
720 case ELF::R_MIPS_PC32:
721 writeBytesUnaligned(CalculatedValue & 0xffffffff, TargetPtr, 4);
724 case ELF::R_MIPS_SUB:
725 writeBytesUnaligned(CalculatedValue, TargetPtr, 8);
728 case ELF::R_MIPS_PC26_S2:
729 Insn = (Insn & 0xfc000000) | CalculatedValue;
730 writeBytesUnaligned(Insn, TargetPtr, 4);
732 case ELF::R_MIPS_GPREL16:
733 Insn = (Insn & 0xffff0000) | (CalculatedValue & 0xffff);
734 writeBytesUnaligned(Insn, TargetPtr, 4);
736 case ELF::R_MIPS_HI16:
737 case ELF::R_MIPS_LO16:
738 case ELF::R_MIPS_PCHI16:
739 case ELF::R_MIPS_PCLO16:
740 case ELF::R_MIPS_PC16:
741 case ELF::R_MIPS_CALL16:
742 case ELF::R_MIPS_GOT_DISP:
743 case ELF::R_MIPS_GOT_PAGE:
744 case ELF::R_MIPS_GOT_OFST:
745 Insn = (Insn & 0xffff0000) | CalculatedValue;
746 writeBytesUnaligned(Insn, TargetPtr, 4);
748 case ELF::R_MIPS_PC18_S3:
749 Insn = (Insn & 0xfffc0000) | CalculatedValue;
750 writeBytesUnaligned(Insn, TargetPtr, 4);
752 case ELF::R_MIPS_PC19_S2:
753 Insn = (Insn & 0xfff80000) | CalculatedValue;
754 writeBytesUnaligned(Insn, TargetPtr, 4);
756 case ELF::R_MIPS_PC21_S2:
757 Insn = (Insn & 0xffe00000) | CalculatedValue;
758 writeBytesUnaligned(Insn, TargetPtr, 4);
763 // Return the .TOC. section and offset.
764 void RuntimeDyldELF::findPPC64TOCSection(const ELFObjectFileBase &Obj,
765 ObjSectionToIDMap &LocalSections,
766 RelocationValueRef &Rel) {
767 // Set a default SectionID in case we do not find a TOC section below.
768 // This may happen for references to TOC base base (sym@toc, .odp
769 // relocation) without a .toc directive. In this case just use the
770 // first section (which is usually the .odp) since the code won't
771 // reference the .toc base directly.
772 Rel.SymbolName = NULL;
775 // The TOC consists of sections .got, .toc, .tocbss, .plt in that
776 // order. The TOC starts where the first of these sections starts.
777 for (auto &Section: Obj.sections()) {
778 StringRef SectionName;
779 check(Section.getName(SectionName));
781 if (SectionName == ".got"
782 || SectionName == ".toc"
783 || SectionName == ".tocbss"
784 || SectionName == ".plt") {
785 Rel.SectionID = findOrEmitSection(Obj, Section, false, LocalSections);
790 // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000
791 // thus permitting a full 64 Kbytes segment.
795 // Returns the sections and offset associated with the ODP entry referenced
797 void RuntimeDyldELF::findOPDEntrySection(const ELFObjectFileBase &Obj,
798 ObjSectionToIDMap &LocalSections,
799 RelocationValueRef &Rel) {
800 // Get the ELF symbol value (st_value) to compare with Relocation offset in
802 for (section_iterator si = Obj.section_begin(), se = Obj.section_end();
804 section_iterator RelSecI = si->getRelocatedSection();
805 if (RelSecI == Obj.section_end())
808 StringRef RelSectionName;
809 check(RelSecI->getName(RelSectionName));
810 if (RelSectionName != ".opd")
813 for (elf_relocation_iterator i = si->relocation_begin(),
814 e = si->relocation_end();
816 // The R_PPC64_ADDR64 relocation indicates the first field
818 uint64_t TypeFunc = i->getType();
819 if (TypeFunc != ELF::R_PPC64_ADDR64) {
824 uint64_t TargetSymbolOffset = i->getOffset();
825 symbol_iterator TargetSymbol = i->getSymbol();
826 ErrorOr<int64_t> AddendOrErr = i->getAddend();
827 Check(AddendOrErr.getError());
828 int64_t Addend = *AddendOrErr;
834 // Just check if following relocation is a R_PPC64_TOC
835 uint64_t TypeTOC = i->getType();
836 if (TypeTOC != ELF::R_PPC64_TOC)
839 // Finally compares the Symbol value and the target symbol offset
840 // to check if this .opd entry refers to the symbol the relocation
842 if (Rel.Addend != (int64_t)TargetSymbolOffset)
845 section_iterator tsi(Obj.section_end());
846 check(TargetSymbol->getSection(tsi));
847 bool IsCode = tsi->isText();
848 Rel.SectionID = findOrEmitSection(Obj, (*tsi), IsCode, LocalSections);
849 Rel.Addend = (intptr_t)Addend;
853 llvm_unreachable("Attempting to get address of ODP entry!");
856 // Relocation masks following the #lo(value), #hi(value), #ha(value),
857 // #higher(value), #highera(value), #highest(value), and #highesta(value)
858 // macros defined in section 4.5.1. Relocation Types of the PPC-elf64abi
861 static inline uint16_t applyPPClo(uint64_t value) { return value & 0xffff; }
863 static inline uint16_t applyPPChi(uint64_t value) {
864 return (value >> 16) & 0xffff;
867 static inline uint16_t applyPPCha (uint64_t value) {
868 return ((value + 0x8000) >> 16) & 0xffff;
871 static inline uint16_t applyPPChigher(uint64_t value) {
872 return (value >> 32) & 0xffff;
875 static inline uint16_t applyPPChighera (uint64_t value) {
876 return ((value + 0x8000) >> 32) & 0xffff;
879 static inline uint16_t applyPPChighest(uint64_t value) {
880 return (value >> 48) & 0xffff;
883 static inline uint16_t applyPPChighesta (uint64_t value) {
884 return ((value + 0x8000) >> 48) & 0xffff;
887 void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section,
888 uint64_t Offset, uint64_t Value,
889 uint32_t Type, int64_t Addend) {
890 uint8_t *LocalAddress = Section.Address + Offset;
893 llvm_unreachable("Relocation type not implemented yet!");
895 case ELF::R_PPC64_ADDR16:
896 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
898 case ELF::R_PPC64_ADDR16_DS:
899 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
901 case ELF::R_PPC64_ADDR16_LO:
902 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
904 case ELF::R_PPC64_ADDR16_LO_DS:
905 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
907 case ELF::R_PPC64_ADDR16_HI:
908 writeInt16BE(LocalAddress, applyPPChi(Value + Addend));
910 case ELF::R_PPC64_ADDR16_HA:
911 writeInt16BE(LocalAddress, applyPPCha(Value + Addend));
913 case ELF::R_PPC64_ADDR16_HIGHER:
914 writeInt16BE(LocalAddress, applyPPChigher(Value + Addend));
916 case ELF::R_PPC64_ADDR16_HIGHERA:
917 writeInt16BE(LocalAddress, applyPPChighera(Value + Addend));
919 case ELF::R_PPC64_ADDR16_HIGHEST:
920 writeInt16BE(LocalAddress, applyPPChighest(Value + Addend));
922 case ELF::R_PPC64_ADDR16_HIGHESTA:
923 writeInt16BE(LocalAddress, applyPPChighesta(Value + Addend));
925 case ELF::R_PPC64_ADDR14: {
926 assert(((Value + Addend) & 3) == 0);
927 // Preserve the AA/LK bits in the branch instruction
928 uint8_t aalk = *(LocalAddress + 3);
929 writeInt16BE(LocalAddress + 2, (aalk & 3) | ((Value + Addend) & 0xfffc));
931 case ELF::R_PPC64_REL16_LO: {
932 uint64_t FinalAddress = (Section.LoadAddress + Offset);
933 uint64_t Delta = Value - FinalAddress + Addend;
934 writeInt16BE(LocalAddress, applyPPClo(Delta));
936 case ELF::R_PPC64_REL16_HI: {
937 uint64_t FinalAddress = (Section.LoadAddress + Offset);
938 uint64_t Delta = Value - FinalAddress + Addend;
939 writeInt16BE(LocalAddress, applyPPChi(Delta));
941 case ELF::R_PPC64_REL16_HA: {
942 uint64_t FinalAddress = (Section.LoadAddress + Offset);
943 uint64_t Delta = Value - FinalAddress + Addend;
944 writeInt16BE(LocalAddress, applyPPCha(Delta));
946 case ELF::R_PPC64_ADDR32: {
947 int32_t Result = static_cast<int32_t>(Value + Addend);
948 if (SignExtend32<32>(Result) != Result)
949 llvm_unreachable("Relocation R_PPC64_ADDR32 overflow");
950 writeInt32BE(LocalAddress, Result);
952 case ELF::R_PPC64_REL24: {
953 uint64_t FinalAddress = (Section.LoadAddress + Offset);
954 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
955 if (SignExtend32<24>(delta) != delta)
956 llvm_unreachable("Relocation R_PPC64_REL24 overflow");
957 // Generates a 'bl <address>' instruction
958 writeInt32BE(LocalAddress, 0x48000001 | (delta & 0x03FFFFFC));
960 case ELF::R_PPC64_REL32: {
961 uint64_t FinalAddress = (Section.LoadAddress + Offset);
962 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
963 if (SignExtend32<32>(delta) != delta)
964 llvm_unreachable("Relocation R_PPC64_REL32 overflow");
965 writeInt32BE(LocalAddress, delta);
967 case ELF::R_PPC64_REL64: {
968 uint64_t FinalAddress = (Section.LoadAddress + Offset);
969 uint64_t Delta = Value - FinalAddress + Addend;
970 writeInt64BE(LocalAddress, Delta);
972 case ELF::R_PPC64_ADDR64:
973 writeInt64BE(LocalAddress, Value + Addend);
978 void RuntimeDyldELF::resolveSystemZRelocation(const SectionEntry &Section,
979 uint64_t Offset, uint64_t Value,
980 uint32_t Type, int64_t Addend) {
981 uint8_t *LocalAddress = Section.Address + Offset;
984 llvm_unreachable("Relocation type not implemented yet!");
986 case ELF::R_390_PC16DBL:
987 case ELF::R_390_PLT16DBL: {
988 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
989 assert(int16_t(Delta / 2) * 2 == Delta && "R_390_PC16DBL overflow");
990 writeInt16BE(LocalAddress, Delta / 2);
993 case ELF::R_390_PC32DBL:
994 case ELF::R_390_PLT32DBL: {
995 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
996 assert(int32_t(Delta / 2) * 2 == Delta && "R_390_PC32DBL overflow");
997 writeInt32BE(LocalAddress, Delta / 2);
1000 case ELF::R_390_PC32: {
1001 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
1002 assert(int32_t(Delta) == Delta && "R_390_PC32 overflow");
1003 writeInt32BE(LocalAddress, Delta);
1007 writeInt64BE(LocalAddress, Value + Addend);
1012 // The target location for the relocation is described by RE.SectionID and
1013 // RE.Offset. RE.SectionID can be used to find the SectionEntry. Each
1014 // SectionEntry has three members describing its location.
1015 // SectionEntry::Address is the address at which the section has been loaded
1016 // into memory in the current (host) process. SectionEntry::LoadAddress is the
1017 // address that the section will have in the target process.
1018 // SectionEntry::ObjAddress is the address of the bits for this section in the
1019 // original emitted object image (also in the current address space).
1021 // Relocations will be applied as if the section were loaded at
1022 // SectionEntry::LoadAddress, but they will be applied at an address based
1023 // on SectionEntry::Address. SectionEntry::ObjAddress will be used to refer to
1024 // Target memory contents if they are required for value calculations.
1026 // The Value parameter here is the load address of the symbol for the
1027 // relocation to be applied. For relocations which refer to symbols in the
1028 // current object Value will be the LoadAddress of the section in which
1029 // the symbol resides (RE.Addend provides additional information about the
1030 // symbol location). For external symbols, Value will be the address of the
1031 // symbol in the target address space.
1032 void RuntimeDyldELF::resolveRelocation(const RelocationEntry &RE,
1034 const SectionEntry &Section = Sections[RE.SectionID];
1035 return resolveRelocation(Section, RE.Offset, Value, RE.RelType, RE.Addend,
1036 RE.SymOffset, RE.SectionID);
1039 void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section,
1040 uint64_t Offset, uint64_t Value,
1041 uint32_t Type, int64_t Addend,
1042 uint64_t SymOffset, SID SectionID) {
1044 case Triple::x86_64:
1045 resolveX86_64Relocation(Section, Offset, Value, Type, Addend, SymOffset);
1048 resolveX86Relocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
1049 (uint32_t)(Addend & 0xffffffffL));
1051 case Triple::aarch64:
1052 case Triple::aarch64_be:
1053 resolveAArch64Relocation(Section, Offset, Value, Type, Addend);
1055 case Triple::arm: // Fall through.
1058 case Triple::thumbeb:
1059 resolveARMRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
1060 (uint32_t)(Addend & 0xffffffffL));
1062 case Triple::mips: // Fall through.
1063 case Triple::mipsel:
1064 case Triple::mips64:
1065 case Triple::mips64el:
1067 resolveMIPSRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL),
1068 Type, (uint32_t)(Addend & 0xffffffffL));
1069 else if (IsMipsN64ABI)
1070 resolveMIPS64Relocation(Section, Offset, Value, Type, Addend, SymOffset,
1073 llvm_unreachable("Mips ABI not handled");
1075 case Triple::ppc64: // Fall through.
1076 case Triple::ppc64le:
1077 resolvePPC64Relocation(Section, Offset, Value, Type, Addend);
1079 case Triple::systemz:
1080 resolveSystemZRelocation(Section, Offset, Value, Type, Addend);
1083 llvm_unreachable("Unsupported CPU type!");
1087 void *RuntimeDyldELF::computePlaceholderAddress(unsigned SectionID, uint64_t Offset) const {
1088 return (void*)(Sections[SectionID].ObjAddress + Offset);
1091 void RuntimeDyldELF::processSimpleRelocation(unsigned SectionID, uint64_t Offset, unsigned RelType, RelocationValueRef Value) {
1092 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend, Value.Offset);
1093 if (Value.SymbolName)
1094 addRelocationForSymbol(RE, Value.SymbolName);
1096 addRelocationForSection(RE, Value.SectionID);
1099 relocation_iterator RuntimeDyldELF::processRelocationRef(
1100 unsigned SectionID, relocation_iterator RelI, const ObjectFile &O,
1101 ObjSectionToIDMap &ObjSectionToID, StubMap &Stubs) {
1102 const auto &Obj = cast<ELFObjectFileBase>(O);
1103 uint64_t RelType = RelI->getType();
1104 ErrorOr<int64_t> AddendOrErr = ELFRelocationRef(*RelI).getAddend();
1105 int64_t Addend = AddendOrErr ? *AddendOrErr : 0;
1106 elf_symbol_iterator Symbol = RelI->getSymbol();
1108 // Obtain the symbol name which is referenced in the relocation
1109 StringRef TargetName;
1110 if (Symbol != Obj.symbol_end()) {
1111 ErrorOr<StringRef> TargetNameOrErr = Symbol->getName();
1112 if (std::error_code EC = TargetNameOrErr.getError())
1113 report_fatal_error(EC.message());
1114 TargetName = *TargetNameOrErr;
1116 DEBUG(dbgs() << "\t\tRelType: " << RelType << " Addend: " << Addend
1117 << " TargetName: " << TargetName << "\n");
1118 RelocationValueRef Value;
1119 // First search for the symbol in the local symbol table
1120 SymbolRef::Type SymType = SymbolRef::ST_Unknown;
1122 // Search for the symbol in the global symbol table
1123 RTDyldSymbolTable::const_iterator gsi = GlobalSymbolTable.end();
1124 if (Symbol != Obj.symbol_end()) {
1125 gsi = GlobalSymbolTable.find(TargetName.data());
1126 SymType = Symbol->getType();
1128 if (gsi != GlobalSymbolTable.end()) {
1129 const auto &SymInfo = gsi->second;
1130 Value.SectionID = SymInfo.getSectionID();
1131 Value.Offset = SymInfo.getOffset();
1132 Value.Addend = SymInfo.getOffset() + Addend;
1135 case SymbolRef::ST_Debug: {
1136 // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously
1137 // and can be changed by another developers. Maybe best way is add
1138 // a new symbol type ST_Section to SymbolRef and use it.
1139 section_iterator si(Obj.section_end());
1140 Symbol->getSection(si);
1141 if (si == Obj.section_end())
1142 llvm_unreachable("Symbol section not found, bad object file format!");
1143 DEBUG(dbgs() << "\t\tThis is section symbol\n");
1144 bool isCode = si->isText();
1145 Value.SectionID = findOrEmitSection(Obj, (*si), isCode, ObjSectionToID);
1146 Value.Addend = Addend;
1149 case SymbolRef::ST_Data:
1150 case SymbolRef::ST_Unknown: {
1151 Value.SymbolName = TargetName.data();
1152 Value.Addend = Addend;
1154 // Absolute relocations will have a zero symbol ID (STN_UNDEF), which
1155 // will manifest here as a NULL symbol name.
1156 // We can set this as a valid (but empty) symbol name, and rely
1157 // on addRelocationForSymbol to handle this.
1158 if (!Value.SymbolName)
1159 Value.SymbolName = "";
1163 llvm_unreachable("Unresolved symbol type!");
1168 uint64_t Offset = RelI->getOffset();
1170 DEBUG(dbgs() << "\t\tSectionID: " << SectionID << " Offset: " << Offset
1172 if ((Arch == Triple::aarch64 || Arch == Triple::aarch64_be) &&
1173 (RelType == ELF::R_AARCH64_CALL26 || RelType == ELF::R_AARCH64_JUMP26)) {
1174 // This is an AArch64 branch relocation, need to use a stub function.
1175 DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation.");
1176 SectionEntry &Section = Sections[SectionID];
1178 // Look for an existing stub.
1179 StubMap::const_iterator i = Stubs.find(Value);
1180 if (i != Stubs.end()) {
1181 resolveRelocation(Section, Offset, (uint64_t)Section.Address + i->second,
1183 DEBUG(dbgs() << " Stub function found\n");
1185 // Create a new stub function.
1186 DEBUG(dbgs() << " Create a new stub function\n");
1187 Stubs[Value] = Section.StubOffset;
1188 uint8_t *StubTargetAddr =
1189 createStubFunction(Section.Address + Section.StubOffset);
1191 RelocationEntry REmovz_g3(SectionID, StubTargetAddr - Section.Address,
1192 ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend);
1193 RelocationEntry REmovk_g2(SectionID, StubTargetAddr - Section.Address + 4,
1194 ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend);
1195 RelocationEntry REmovk_g1(SectionID, StubTargetAddr - Section.Address + 8,
1196 ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend);
1197 RelocationEntry REmovk_g0(SectionID,
1198 StubTargetAddr - Section.Address + 12,
1199 ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend);
1201 if (Value.SymbolName) {
1202 addRelocationForSymbol(REmovz_g3, Value.SymbolName);
1203 addRelocationForSymbol(REmovk_g2, Value.SymbolName);
1204 addRelocationForSymbol(REmovk_g1, Value.SymbolName);
1205 addRelocationForSymbol(REmovk_g0, Value.SymbolName);
1207 addRelocationForSection(REmovz_g3, Value.SectionID);
1208 addRelocationForSection(REmovk_g2, Value.SectionID);
1209 addRelocationForSection(REmovk_g1, Value.SectionID);
1210 addRelocationForSection(REmovk_g0, Value.SectionID);
1212 resolveRelocation(Section, Offset,
1213 (uint64_t)Section.Address + Section.StubOffset, RelType,
1215 Section.StubOffset += getMaxStubSize();
1217 } else if (Arch == Triple::arm) {
1218 if (RelType == ELF::R_ARM_PC24 || RelType == ELF::R_ARM_CALL ||
1219 RelType == ELF::R_ARM_JUMP24) {
1220 // This is an ARM branch relocation, need to use a stub function.
1221 DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.");
1222 SectionEntry &Section = Sections[SectionID];
1224 // Look for an existing stub.
1225 StubMap::const_iterator i = Stubs.find(Value);
1226 if (i != Stubs.end()) {
1227 resolveRelocation(Section, Offset, (uint64_t)Section.Address + i->second,
1229 DEBUG(dbgs() << " Stub function found\n");
1231 // Create a new stub function.
1232 DEBUG(dbgs() << " Create a new stub function\n");
1233 Stubs[Value] = Section.StubOffset;
1234 uint8_t *StubTargetAddr =
1235 createStubFunction(Section.Address + Section.StubOffset);
1236 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1237 ELF::R_ARM_ABS32, Value.Addend);
1238 if (Value.SymbolName)
1239 addRelocationForSymbol(RE, Value.SymbolName);
1241 addRelocationForSection(RE, Value.SectionID);
1243 resolveRelocation(Section, Offset,
1244 (uint64_t)Section.Address + Section.StubOffset, RelType,
1246 Section.StubOffset += getMaxStubSize();
1249 uint32_t *Placeholder =
1250 reinterpret_cast<uint32_t*>(computePlaceholderAddress(SectionID, Offset));
1251 if (RelType == ELF::R_ARM_PREL31 || RelType == ELF::R_ARM_TARGET1 ||
1252 RelType == ELF::R_ARM_ABS32) {
1253 Value.Addend += *Placeholder;
1254 } else if (RelType == ELF::R_ARM_MOVW_ABS_NC || RelType == ELF::R_ARM_MOVT_ABS) {
1255 // See ELF for ARM documentation
1256 Value.Addend += (int16_t)((*Placeholder & 0xFFF) | (((*Placeholder >> 16) & 0xF) << 12));
1258 processSimpleRelocation(SectionID, Offset, RelType, Value);
1260 } else if (IsMipsO32ABI) {
1261 uint8_t *Placeholder = reinterpret_cast<uint8_t *>(
1262 computePlaceholderAddress(SectionID, Offset));
1263 uint32_t Opcode = readBytesUnaligned(Placeholder, 4);
1264 if (RelType == ELF::R_MIPS_26) {
1265 // This is an Mips branch relocation, need to use a stub function.
1266 DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
1267 SectionEntry &Section = Sections[SectionID];
1269 // Extract the addend from the instruction.
1270 // We shift up by two since the Value will be down shifted again
1271 // when applying the relocation.
1272 uint32_t Addend = (Opcode & 0x03ffffff) << 2;
1274 Value.Addend += Addend;
1276 // Look up for existing stub.
1277 StubMap::const_iterator i = Stubs.find(Value);
1278 if (i != Stubs.end()) {
1279 RelocationEntry RE(SectionID, Offset, RelType, i->second);
1280 addRelocationForSection(RE, SectionID);
1281 DEBUG(dbgs() << " Stub function found\n");
1283 // Create a new stub function.
1284 DEBUG(dbgs() << " Create a new stub function\n");
1285 Stubs[Value] = Section.StubOffset;
1286 uint8_t *StubTargetAddr =
1287 createStubFunction(Section.Address + Section.StubOffset);
1289 // Creating Hi and Lo relocations for the filled stub instructions.
1290 RelocationEntry REHi(SectionID, StubTargetAddr - Section.Address,
1291 ELF::R_MIPS_HI16, Value.Addend);
1292 RelocationEntry RELo(SectionID, StubTargetAddr - Section.Address + 4,
1293 ELF::R_MIPS_LO16, Value.Addend);
1295 if (Value.SymbolName) {
1296 addRelocationForSymbol(REHi, Value.SymbolName);
1297 addRelocationForSymbol(RELo, Value.SymbolName);
1300 addRelocationForSection(REHi, Value.SectionID);
1301 addRelocationForSection(RELo, Value.SectionID);
1304 RelocationEntry RE(SectionID, Offset, RelType, Section.StubOffset);
1305 addRelocationForSection(RE, SectionID);
1306 Section.StubOffset += getMaxStubSize();
1309 // FIXME: Calculate correct addends for R_MIPS_HI16, R_MIPS_LO16,
1310 // R_MIPS_PCHI16 and R_MIPS_PCLO16 relocations.
1311 if (RelType == ELF::R_MIPS_HI16 || RelType == ELF::R_MIPS_PCHI16)
1312 Value.Addend += (Opcode & 0x0000ffff) << 16;
1313 else if (RelType == ELF::R_MIPS_LO16)
1314 Value.Addend += (Opcode & 0x0000ffff);
1315 else if (RelType == ELF::R_MIPS_32)
1316 Value.Addend += Opcode;
1317 else if (RelType == ELF::R_MIPS_PCLO16)
1318 Value.Addend += SignExtend32<16>((Opcode & 0x0000ffff));
1319 else if (RelType == ELF::R_MIPS_PC16)
1320 Value.Addend += SignExtend32<18>((Opcode & 0x0000ffff) << 2);
1321 else if (RelType == ELF::R_MIPS_PC19_S2)
1322 Value.Addend += SignExtend32<21>((Opcode & 0x0007ffff) << 2);
1323 else if (RelType == ELF::R_MIPS_PC21_S2)
1324 Value.Addend += SignExtend32<23>((Opcode & 0x001fffff) << 2);
1325 else if (RelType == ELF::R_MIPS_PC26_S2)
1326 Value.Addend += SignExtend32<28>((Opcode & 0x03ffffff) << 2);
1327 processSimpleRelocation(SectionID, Offset, RelType, Value);
1329 } else if (IsMipsN64ABI) {
1330 uint32_t r_type = RelType & 0xff;
1331 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1332 if (r_type == ELF::R_MIPS_CALL16 || r_type == ELF::R_MIPS_GOT_PAGE
1333 || r_type == ELF::R_MIPS_GOT_DISP) {
1334 StringMap<uint64_t>::iterator i = GOTSymbolOffsets.find(TargetName);
1335 if (i != GOTSymbolOffsets.end())
1336 RE.SymOffset = i->second;
1338 RE.SymOffset = allocateGOTEntries(SectionID, 1);
1339 GOTSymbolOffsets[TargetName] = RE.SymOffset;
1342 if (Value.SymbolName)
1343 addRelocationForSymbol(RE, Value.SymbolName);
1345 addRelocationForSection(RE, Value.SectionID);
1346 } else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) {
1347 if (RelType == ELF::R_PPC64_REL24) {
1348 // Determine ABI variant in use for this object.
1349 unsigned AbiVariant;
1350 Obj.getPlatformFlags(AbiVariant);
1351 AbiVariant &= ELF::EF_PPC64_ABI;
1352 // A PPC branch relocation will need a stub function if the target is
1353 // an external symbol (Symbol::ST_Unknown) or if the target address
1354 // is not within the signed 24-bits branch address.
1355 SectionEntry &Section = Sections[SectionID];
1356 uint8_t *Target = Section.Address + Offset;
1357 bool RangeOverflow = false;
1358 if (SymType != SymbolRef::ST_Unknown) {
1359 if (AbiVariant != 2) {
1360 // In the ELFv1 ABI, a function call may point to the .opd entry,
1361 // so the final symbol value is calculated based on the relocation
1362 // values in the .opd section.
1363 findOPDEntrySection(Obj, ObjSectionToID, Value);
1365 // In the ELFv2 ABI, a function symbol may provide a local entry
1366 // point, which must be used for direct calls.
1367 uint8_t SymOther = Symbol->getOther();
1368 Value.Addend += ELF::decodePPC64LocalEntryOffset(SymOther);
1370 uint8_t *RelocTarget = Sections[Value.SectionID].Address + Value.Addend;
1371 int32_t delta = static_cast<int32_t>(Target - RelocTarget);
1372 // If it is within 24-bits branch range, just set the branch target
1373 if (SignExtend32<24>(delta) == delta) {
1374 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1375 if (Value.SymbolName)
1376 addRelocationForSymbol(RE, Value.SymbolName);
1378 addRelocationForSection(RE, Value.SectionID);
1380 RangeOverflow = true;
1383 if (SymType == SymbolRef::ST_Unknown || RangeOverflow) {
1384 // It is an external symbol (SymbolRef::ST_Unknown) or within a range
1385 // larger than 24-bits.
1386 StubMap::const_iterator i = Stubs.find(Value);
1387 if (i != Stubs.end()) {
1388 // Symbol function stub already created, just relocate to it
1389 resolveRelocation(Section, Offset,
1390 (uint64_t)Section.Address + i->second, RelType, 0);
1391 DEBUG(dbgs() << " Stub function found\n");
1393 // Create a new stub function.
1394 DEBUG(dbgs() << " Create a new stub function\n");
1395 Stubs[Value] = Section.StubOffset;
1396 uint8_t *StubTargetAddr =
1397 createStubFunction(Section.Address + Section.StubOffset,
1399 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1400 ELF::R_PPC64_ADDR64, Value.Addend);
1402 // Generates the 64-bits address loads as exemplified in section
1403 // 4.5.1 in PPC64 ELF ABI. Note that the relocations need to
1404 // apply to the low part of the instructions, so we have to update
1405 // the offset according to the target endianness.
1406 uint64_t StubRelocOffset = StubTargetAddr - Section.Address;
1407 if (!IsTargetLittleEndian)
1408 StubRelocOffset += 2;
1410 RelocationEntry REhst(SectionID, StubRelocOffset + 0,
1411 ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend);
1412 RelocationEntry REhr(SectionID, StubRelocOffset + 4,
1413 ELF::R_PPC64_ADDR16_HIGHER, Value.Addend);
1414 RelocationEntry REh(SectionID, StubRelocOffset + 12,
1415 ELF::R_PPC64_ADDR16_HI, Value.Addend);
1416 RelocationEntry REl(SectionID, StubRelocOffset + 16,
1417 ELF::R_PPC64_ADDR16_LO, Value.Addend);
1419 if (Value.SymbolName) {
1420 addRelocationForSymbol(REhst, Value.SymbolName);
1421 addRelocationForSymbol(REhr, Value.SymbolName);
1422 addRelocationForSymbol(REh, Value.SymbolName);
1423 addRelocationForSymbol(REl, Value.SymbolName);
1425 addRelocationForSection(REhst, Value.SectionID);
1426 addRelocationForSection(REhr, Value.SectionID);
1427 addRelocationForSection(REh, Value.SectionID);
1428 addRelocationForSection(REl, Value.SectionID);
1431 resolveRelocation(Section, Offset,
1432 (uint64_t)Section.Address + Section.StubOffset,
1434 Section.StubOffset += getMaxStubSize();
1436 if (SymType == SymbolRef::ST_Unknown) {
1437 // Restore the TOC for external calls
1438 if (AbiVariant == 2)
1439 writeInt32BE(Target + 4, 0xE8410018); // ld r2,28(r1)
1441 writeInt32BE(Target + 4, 0xE8410028); // ld r2,40(r1)
1444 } else if (RelType == ELF::R_PPC64_TOC16 ||
1445 RelType == ELF::R_PPC64_TOC16_DS ||
1446 RelType == ELF::R_PPC64_TOC16_LO ||
1447 RelType == ELF::R_PPC64_TOC16_LO_DS ||
1448 RelType == ELF::R_PPC64_TOC16_HI ||
1449 RelType == ELF::R_PPC64_TOC16_HA) {
1450 // These relocations are supposed to subtract the TOC address from
1451 // the final value. This does not fit cleanly into the RuntimeDyld
1452 // scheme, since there may be *two* sections involved in determining
1453 // the relocation value (the section of the symbol refered to by the
1454 // relocation, and the TOC section associated with the current module).
1456 // Fortunately, these relocations are currently only ever generated
1457 // refering to symbols that themselves reside in the TOC, which means
1458 // that the two sections are actually the same. Thus they cancel out
1459 // and we can immediately resolve the relocation right now.
1461 case ELF::R_PPC64_TOC16: RelType = ELF::R_PPC64_ADDR16; break;
1462 case ELF::R_PPC64_TOC16_DS: RelType = ELF::R_PPC64_ADDR16_DS; break;
1463 case ELF::R_PPC64_TOC16_LO: RelType = ELF::R_PPC64_ADDR16_LO; break;
1464 case ELF::R_PPC64_TOC16_LO_DS: RelType = ELF::R_PPC64_ADDR16_LO_DS; break;
1465 case ELF::R_PPC64_TOC16_HI: RelType = ELF::R_PPC64_ADDR16_HI; break;
1466 case ELF::R_PPC64_TOC16_HA: RelType = ELF::R_PPC64_ADDR16_HA; break;
1467 default: llvm_unreachable("Wrong relocation type.");
1470 RelocationValueRef TOCValue;
1471 findPPC64TOCSection(Obj, ObjSectionToID, TOCValue);
1472 if (Value.SymbolName || Value.SectionID != TOCValue.SectionID)
1473 llvm_unreachable("Unsupported TOC relocation.");
1474 Value.Addend -= TOCValue.Addend;
1475 resolveRelocation(Sections[SectionID], Offset, Value.Addend, RelType, 0);
1477 // There are two ways to refer to the TOC address directly: either
1478 // via a ELF::R_PPC64_TOC relocation (where both symbol and addend are
1479 // ignored), or via any relocation that refers to the magic ".TOC."
1480 // symbols (in which case the addend is respected).
1481 if (RelType == ELF::R_PPC64_TOC) {
1482 RelType = ELF::R_PPC64_ADDR64;
1483 findPPC64TOCSection(Obj, ObjSectionToID, Value);
1484 } else if (TargetName == ".TOC.") {
1485 findPPC64TOCSection(Obj, ObjSectionToID, Value);
1486 Value.Addend += Addend;
1489 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1491 if (Value.SymbolName)
1492 addRelocationForSymbol(RE, Value.SymbolName);
1494 addRelocationForSection(RE, Value.SectionID);
1496 } else if (Arch == Triple::systemz &&
1497 (RelType == ELF::R_390_PLT32DBL || RelType == ELF::R_390_GOTENT)) {
1498 // Create function stubs for both PLT and GOT references, regardless of
1499 // whether the GOT reference is to data or code. The stub contains the
1500 // full address of the symbol, as needed by GOT references, and the
1501 // executable part only adds an overhead of 8 bytes.
1503 // We could try to conserve space by allocating the code and data
1504 // parts of the stub separately. However, as things stand, we allocate
1505 // a stub for every relocation, so using a GOT in JIT code should be
1506 // no less space efficient than using an explicit constant pool.
1507 DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation.");
1508 SectionEntry &Section = Sections[SectionID];
1510 // Look for an existing stub.
1511 StubMap::const_iterator i = Stubs.find(Value);
1512 uintptr_t StubAddress;
1513 if (i != Stubs.end()) {
1514 StubAddress = uintptr_t(Section.Address) + i->second;
1515 DEBUG(dbgs() << " Stub function found\n");
1517 // Create a new stub function.
1518 DEBUG(dbgs() << " Create a new stub function\n");
1520 uintptr_t BaseAddress = uintptr_t(Section.Address);
1521 uintptr_t StubAlignment = getStubAlignment();
1522 StubAddress = (BaseAddress + Section.StubOffset + StubAlignment - 1) &
1524 unsigned StubOffset = StubAddress - BaseAddress;
1526 Stubs[Value] = StubOffset;
1527 createStubFunction((uint8_t *)StubAddress);
1528 RelocationEntry RE(SectionID, StubOffset + 8, ELF::R_390_64,
1530 if (Value.SymbolName)
1531 addRelocationForSymbol(RE, Value.SymbolName);
1533 addRelocationForSection(RE, Value.SectionID);
1534 Section.StubOffset = StubOffset + getMaxStubSize();
1537 if (RelType == ELF::R_390_GOTENT)
1538 resolveRelocation(Section, Offset, StubAddress + 8, ELF::R_390_PC32DBL,
1541 resolveRelocation(Section, Offset, StubAddress, RelType, Addend);
1542 } else if (Arch == Triple::x86_64) {
1543 if (RelType == ELF::R_X86_64_PLT32) {
1544 // The way the PLT relocations normally work is that the linker allocates
1546 // PLT and this relocation makes a PC-relative call into the PLT. The PLT
1547 // entry will then jump to an address provided by the GOT. On first call,
1549 // GOT address will point back into PLT code that resolves the symbol. After
1550 // the first call, the GOT entry points to the actual function.
1552 // For local functions we're ignoring all of that here and just replacing
1553 // the PLT32 relocation type with PC32, which will translate the relocation
1554 // into a PC-relative call directly to the function. For external symbols we
1555 // can't be sure the function will be within 2^32 bytes of the call site, so
1556 // we need to create a stub, which calls into the GOT. This case is
1557 // equivalent to the usual PLT implementation except that we use the stub
1558 // mechanism in RuntimeDyld (which puts stubs at the end of the section)
1559 // rather than allocating a PLT section.
1560 if (Value.SymbolName) {
1561 // This is a call to an external function.
1562 // Look for an existing stub.
1563 SectionEntry &Section = Sections[SectionID];
1564 StubMap::const_iterator i = Stubs.find(Value);
1565 uintptr_t StubAddress;
1566 if (i != Stubs.end()) {
1567 StubAddress = uintptr_t(Section.Address) + i->second;
1568 DEBUG(dbgs() << " Stub function found\n");
1570 // Create a new stub function (equivalent to a PLT entry).
1571 DEBUG(dbgs() << " Create a new stub function\n");
1573 uintptr_t BaseAddress = uintptr_t(Section.Address);
1574 uintptr_t StubAlignment = getStubAlignment();
1575 StubAddress = (BaseAddress + Section.StubOffset + StubAlignment - 1) &
1577 unsigned StubOffset = StubAddress - BaseAddress;
1578 Stubs[Value] = StubOffset;
1579 createStubFunction((uint8_t *)StubAddress);
1581 // Bump our stub offset counter
1582 Section.StubOffset = StubOffset + getMaxStubSize();
1584 // Allocate a GOT Entry
1585 uint64_t GOTOffset = allocateGOTEntries(SectionID, 1);
1587 // The load of the GOT address has an addend of -4
1588 resolveGOTOffsetRelocation(SectionID, StubOffset + 2, GOTOffset - 4);
1590 // Fill in the value of the symbol we're targeting into the GOT
1591 addRelocationForSymbol(computeGOTOffsetRE(SectionID,GOTOffset,0,ELF::R_X86_64_64),
1595 // Make the target call a call into the stub table.
1596 resolveRelocation(Section, Offset, StubAddress, ELF::R_X86_64_PC32,
1599 RelocationEntry RE(SectionID, Offset, ELF::R_X86_64_PC32, Value.Addend,
1601 addRelocationForSection(RE, Value.SectionID);
1603 } else if (RelType == ELF::R_X86_64_GOTPCREL) {
1604 uint64_t GOTOffset = allocateGOTEntries(SectionID, 1);
1605 resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend);
1607 // Fill in the value of the symbol we're targeting into the GOT
1608 RelocationEntry RE = computeGOTOffsetRE(SectionID, GOTOffset, Value.Offset, ELF::R_X86_64_64);
1609 if (Value.SymbolName)
1610 addRelocationForSymbol(RE, Value.SymbolName);
1612 addRelocationForSection(RE, Value.SectionID);
1613 } else if (RelType == ELF::R_X86_64_PC32) {
1614 Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset));
1615 processSimpleRelocation(SectionID, Offset, RelType, Value);
1616 } else if (RelType == ELF::R_X86_64_PC64) {
1617 Value.Addend += support::ulittle64_t::ref(computePlaceholderAddress(SectionID, Offset));
1618 processSimpleRelocation(SectionID, Offset, RelType, Value);
1620 processSimpleRelocation(SectionID, Offset, RelType, Value);
1623 if (Arch == Triple::x86) {
1624 Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset));
1626 processSimpleRelocation(SectionID, Offset, RelType, Value);
1631 size_t RuntimeDyldELF::getGOTEntrySize() {
1632 // We don't use the GOT in all of these cases, but it's essentially free
1633 // to put them all here.
1636 case Triple::x86_64:
1637 case Triple::aarch64:
1638 case Triple::aarch64_be:
1640 case Triple::ppc64le:
1641 case Triple::systemz:
1642 Result = sizeof(uint64_t);
1647 Result = sizeof(uint32_t);
1650 case Triple::mipsel:
1651 case Triple::mips64:
1652 case Triple::mips64el:
1654 Result = sizeof(uint32_t);
1655 else if (IsMipsN64ABI)
1656 Result = sizeof(uint64_t);
1658 llvm_unreachable("Mips ABI not handled");
1661 llvm_unreachable("Unsupported CPU type!");
1666 uint64_t RuntimeDyldELF::allocateGOTEntries(unsigned SectionID, unsigned no)
1668 (void)SectionID; // The GOT Section is the same for all section in the object file
1669 if (GOTSectionID == 0) {
1670 GOTSectionID = Sections.size();
1671 // Reserve a section id. We'll allocate the section later
1672 // once we know the total size
1673 Sections.push_back(SectionEntry(".got", 0, 0, 0));
1675 uint64_t StartOffset = CurrentGOTIndex * getGOTEntrySize();
1676 CurrentGOTIndex += no;
1680 void RuntimeDyldELF::resolveGOTOffsetRelocation(unsigned SectionID, uint64_t Offset, uint64_t GOTOffset)
1682 // Fill in the relative address of the GOT Entry into the stub
1683 RelocationEntry GOTRE(SectionID, Offset, ELF::R_X86_64_PC32, GOTOffset);
1684 addRelocationForSection(GOTRE, GOTSectionID);
1687 RelocationEntry RuntimeDyldELF::computeGOTOffsetRE(unsigned SectionID, uint64_t GOTOffset, uint64_t SymbolOffset,
1690 (void)SectionID; // The GOT Section is the same for all section in the object file
1691 return RelocationEntry(GOTSectionID, GOTOffset, Type, SymbolOffset);
1694 void RuntimeDyldELF::finalizeLoad(const ObjectFile &Obj,
1695 ObjSectionToIDMap &SectionMap) {
1696 // If necessary, allocate the global offset table
1697 if (GOTSectionID != 0) {
1698 // Allocate memory for the section
1699 size_t TotalSize = CurrentGOTIndex * getGOTEntrySize();
1700 uint8_t *Addr = MemMgr.allocateDataSection(TotalSize, getGOTEntrySize(),
1701 GOTSectionID, ".got", false);
1703 report_fatal_error("Unable to allocate memory for GOT!");
1705 Sections[GOTSectionID] = SectionEntry(".got", Addr, TotalSize, 0);
1708 Checker->registerSection(Obj.getFileName(), GOTSectionID);
1710 // For now, initialize all GOT entries to zero. We'll fill them in as
1711 // needed when GOT-based relocations are applied.
1712 memset(Addr, 0, TotalSize);
1714 // To correctly resolve Mips GOT relocations, we need a mapping from
1715 // object's sections to GOTs.
1716 for (section_iterator SI = Obj.section_begin(), SE = Obj.section_end();
1718 if (SI->relocation_begin() != SI->relocation_end()) {
1719 section_iterator RelocatedSection = SI->getRelocatedSection();
1720 ObjSectionToIDMap::iterator i = SectionMap.find(*RelocatedSection);
1721 assert (i != SectionMap.end());
1722 SectionToGOTMap[i->second] = GOTSectionID;
1725 GOTSymbolOffsets.clear();
1729 // Look for and record the EH frame section.
1730 ObjSectionToIDMap::iterator i, e;
1731 for (i = SectionMap.begin(), e = SectionMap.end(); i != e; ++i) {
1732 const SectionRef &Section = i->first;
1734 Section.getName(Name);
1735 if (Name == ".eh_frame") {
1736 UnregisteredEHFrameSections.push_back(i->second);
1742 CurrentGOTIndex = 0;
1745 bool RuntimeDyldELF::isCompatibleFile(const object::ObjectFile &Obj) const {