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 uint32_t *TargetPtr = (uint32_t *)(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");
491 llvm_unreachable("Not implemented relocation type!");
497 *TargetPtr = ((*TargetPtr) & 0xfc000000) | ((Value & 0x0fffffff) >> 2);
499 case ELF::R_MIPS_HI16:
500 // Get the higher 16-bits. Also add 1 if bit 15 is 1.
502 ((*TargetPtr) & 0xffff0000) | (((Value + 0x8000) >> 16) & 0xffff);
504 case ELF::R_MIPS_LO16:
505 *TargetPtr = ((*TargetPtr) & 0xffff0000) | (Value & 0xffff);
507 case ELF::R_MIPS_PC32:
508 uint32_t FinalAddress = (Section.LoadAddress + Offset);
509 writeBytesUnaligned(Value + Addend - FinalAddress, (uint8_t *)TargetPtr, 4);
514 void RuntimeDyldELF::setMipsABI(const ObjectFile &Obj) {
515 if (!StringRef(Triple::getArchTypePrefix(Arch)).equals("mips")) {
516 IsMipsO32ABI = false;
517 IsMipsN64ABI = false;
521 Obj.getPlatformFlags(AbiVariant);
522 IsMipsO32ABI = AbiVariant & ELF::EF_MIPS_ABI_O32;
523 IsMipsN64ABI = Obj.getFileFormatName().equals("ELF64-mips");
524 if (AbiVariant & ELF::EF_MIPS_ABI2)
525 llvm_unreachable("Mips N32 ABI is not supported yet");
528 void RuntimeDyldELF::resolveMIPS64Relocation(const SectionEntry &Section,
529 uint64_t Offset, uint64_t Value,
530 uint32_t Type, int64_t Addend,
533 uint32_t r_type = Type & 0xff;
534 uint32_t r_type2 = (Type >> 8) & 0xff;
535 uint32_t r_type3 = (Type >> 16) & 0xff;
537 // RelType is used to keep information for which relocation type we are
538 // applying relocation.
539 uint32_t RelType = r_type;
540 int64_t CalculatedValue = evaluateMIPS64Relocation(Section, Offset, Value,
542 SymOffset, SectionID);
543 if (r_type2 != ELF::R_MIPS_NONE) {
545 CalculatedValue = evaluateMIPS64Relocation(Section, Offset, 0, RelType,
546 CalculatedValue, SymOffset,
549 if (r_type3 != ELF::R_MIPS_NONE) {
551 CalculatedValue = evaluateMIPS64Relocation(Section, Offset, 0, RelType,
552 CalculatedValue, SymOffset,
555 applyMIPS64Relocation(Section.Address + Offset, CalculatedValue, RelType);
559 RuntimeDyldELF::evaluateMIPS64Relocation(const SectionEntry &Section,
560 uint64_t Offset, uint64_t Value,
561 uint32_t Type, int64_t Addend,
562 uint64_t SymOffset, SID SectionID) {
564 DEBUG(dbgs() << "evaluateMIPS64Relocation, LocalAddress: 0x"
565 << format("%llx", Section.Address + Offset)
566 << " FinalAddress: 0x"
567 << format("%llx", Section.LoadAddress + Offset)
568 << " Value: 0x" << format("%llx", Value) << " Type: 0x"
569 << format("%x", Type) << " Addend: 0x" << format("%llx", Addend)
570 << " SymOffset: " << format("%x", SymOffset)
575 llvm_unreachable("Not implemented relocation type!");
577 case ELF::R_MIPS_JALR:
578 case ELF::R_MIPS_NONE:
582 return Value + Addend;
584 return ((Value + Addend) >> 2) & 0x3ffffff;
585 case ELF::R_MIPS_GPREL16: {
586 uint64_t GOTAddr = getSectionLoadAddress(SectionToGOTMap[SectionID]);
587 return Value + Addend - (GOTAddr + 0x7ff0);
589 case ELF::R_MIPS_SUB:
590 return Value - Addend;
591 case ELF::R_MIPS_HI16:
592 // Get the higher 16-bits. Also add 1 if bit 15 is 1.
593 return ((Value + Addend + 0x8000) >> 16) & 0xffff;
594 case ELF::R_MIPS_LO16:
595 return (Value + Addend) & 0xffff;
596 case ELF::R_MIPS_CALL16:
597 case ELF::R_MIPS_GOT_DISP:
598 case ELF::R_MIPS_GOT_PAGE: {
599 uint8_t *LocalGOTAddr =
600 getSectionAddress(SectionToGOTMap[SectionID]) + SymOffset;
601 uint64_t GOTEntry = readBytesUnaligned(LocalGOTAddr, 8);
604 if (Type == ELF::R_MIPS_GOT_PAGE)
605 Value = (Value + 0x8000) & ~0xffff;
608 assert(GOTEntry == Value &&
609 "GOT entry has two different addresses.");
611 writeBytesUnaligned(Value, LocalGOTAddr, 8);
613 return (SymOffset - 0x7ff0) & 0xffff;
615 case ELF::R_MIPS_GOT_OFST: {
616 int64_t page = (Value + Addend + 0x8000) & ~0xffff;
617 return (Value + Addend - page) & 0xffff;
619 case ELF::R_MIPS_GPREL32: {
620 uint64_t GOTAddr = getSectionLoadAddress(SectionToGOTMap[SectionID]);
621 return Value + Addend - (GOTAddr + 0x7ff0);
623 case ELF::R_MIPS_PC16: {
624 uint64_t FinalAddress = (Section.LoadAddress + Offset);
625 return ((Value + Addend - FinalAddress - 4) >> 2) & 0xffff;
627 case ELF::R_MIPS_PC18_S3: {
628 uint64_t FinalAddress = (Section.LoadAddress + Offset);
629 return ((Value + Addend - ((FinalAddress | 7) ^ 7)) >> 3) & 0x3ffff;
631 case ELF::R_MIPS_PC19_S2: {
632 uint64_t FinalAddress = (Section.LoadAddress + Offset);
633 return ((Value + Addend - FinalAddress) >> 2) & 0x7ffff;
635 case ELF::R_MIPS_PC21_S2: {
636 uint64_t FinalAddress = (Section.LoadAddress + Offset);
637 return ((Value + Addend - FinalAddress) >> 2) & 0x1fffff;
639 case ELF::R_MIPS_PC26_S2: {
640 uint64_t FinalAddress = (Section.LoadAddress + Offset);
641 return ((Value + Addend - FinalAddress) >> 2) & 0x3ffffff;
643 case ELF::R_MIPS_PCHI16: {
644 uint64_t FinalAddress = (Section.LoadAddress + Offset);
645 return ((Value + Addend - FinalAddress + 0x8000) >> 16) & 0xffff;
647 case ELF::R_MIPS_PCLO16: {
648 uint64_t FinalAddress = (Section.LoadAddress + Offset);
649 return (Value + Addend - FinalAddress) & 0xffff;
655 void RuntimeDyldELF::applyMIPS64Relocation(uint8_t *TargetPtr,
656 int64_t CalculatedValue,
658 uint32_t Insn = readBytesUnaligned(TargetPtr, 4);
664 case ELF::R_MIPS_GPREL32:
665 writeBytesUnaligned(CalculatedValue & 0xffffffff, TargetPtr, 4);
668 case ELF::R_MIPS_SUB:
669 writeBytesUnaligned(CalculatedValue, TargetPtr, 8);
672 case ELF::R_MIPS_PC26_S2:
673 Insn = (Insn & 0xfc000000) | CalculatedValue;
674 writeBytesUnaligned(Insn, TargetPtr, 4);
676 case ELF::R_MIPS_GPREL16:
677 Insn = (Insn & 0xffff0000) | (CalculatedValue & 0xffff);
678 writeBytesUnaligned(Insn, TargetPtr, 4);
680 case ELF::R_MIPS_HI16:
681 case ELF::R_MIPS_LO16:
682 case ELF::R_MIPS_PCHI16:
683 case ELF::R_MIPS_PCLO16:
684 case ELF::R_MIPS_PC16:
685 case ELF::R_MIPS_CALL16:
686 case ELF::R_MIPS_GOT_DISP:
687 case ELF::R_MIPS_GOT_PAGE:
688 case ELF::R_MIPS_GOT_OFST:
689 Insn = (Insn & 0xffff0000) | CalculatedValue;
690 writeBytesUnaligned(Insn, TargetPtr, 4);
692 case ELF::R_MIPS_PC18_S3:
693 Insn = (Insn & 0xfffc0000) | CalculatedValue;
694 writeBytesUnaligned(Insn, TargetPtr, 4);
696 case ELF::R_MIPS_PC19_S2:
697 Insn = (Insn & 0xfff80000) | CalculatedValue;
698 writeBytesUnaligned(Insn, TargetPtr, 4);
700 case ELF::R_MIPS_PC21_S2:
701 Insn = (Insn & 0xffe00000) | CalculatedValue;
702 writeBytesUnaligned(Insn, TargetPtr, 4);
707 // Return the .TOC. section and offset.
708 void RuntimeDyldELF::findPPC64TOCSection(const ObjectFile &Obj,
709 ObjSectionToIDMap &LocalSections,
710 RelocationValueRef &Rel) {
711 // Set a default SectionID in case we do not find a TOC section below.
712 // This may happen for references to TOC base base (sym@toc, .odp
713 // relocation) without a .toc directive. In this case just use the
714 // first section (which is usually the .odp) since the code won't
715 // reference the .toc base directly.
716 Rel.SymbolName = NULL;
719 // The TOC consists of sections .got, .toc, .tocbss, .plt in that
720 // order. The TOC starts where the first of these sections starts.
721 for (auto &Section: Obj.sections()) {
722 StringRef SectionName;
723 check(Section.getName(SectionName));
725 if (SectionName == ".got"
726 || SectionName == ".toc"
727 || SectionName == ".tocbss"
728 || SectionName == ".plt") {
729 Rel.SectionID = findOrEmitSection(Obj, Section, false, LocalSections);
734 // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000
735 // thus permitting a full 64 Kbytes segment.
739 // Returns the sections and offset associated with the ODP entry referenced
741 void RuntimeDyldELF::findOPDEntrySection(const ObjectFile &Obj,
742 ObjSectionToIDMap &LocalSections,
743 RelocationValueRef &Rel) {
744 // Get the ELF symbol value (st_value) to compare with Relocation offset in
746 for (section_iterator si = Obj.section_begin(), se = Obj.section_end();
748 section_iterator RelSecI = si->getRelocatedSection();
749 if (RelSecI == Obj.section_end())
752 StringRef RelSectionName;
753 check(RelSecI->getName(RelSectionName));
754 if (RelSectionName != ".opd")
757 for (relocation_iterator i = si->relocation_begin(),
758 e = si->relocation_end();
760 // The R_PPC64_ADDR64 relocation indicates the first field
763 check(i->getType(TypeFunc));
764 if (TypeFunc != ELF::R_PPC64_ADDR64) {
769 uint64_t TargetSymbolOffset;
770 symbol_iterator TargetSymbol = i->getSymbol();
771 check(i->getOffset(TargetSymbolOffset));
773 check(getELFRelocationAddend(*i, Addend));
779 // Just check if following relocation is a R_PPC64_TOC
781 check(i->getType(TypeTOC));
782 if (TypeTOC != ELF::R_PPC64_TOC)
785 // Finally compares the Symbol value and the target symbol offset
786 // to check if this .opd entry refers to the symbol the relocation
788 if (Rel.Addend != (int64_t)TargetSymbolOffset)
791 section_iterator tsi(Obj.section_end());
792 check(TargetSymbol->getSection(tsi));
793 bool IsCode = tsi->isText();
794 Rel.SectionID = findOrEmitSection(Obj, (*tsi), IsCode, LocalSections);
795 Rel.Addend = (intptr_t)Addend;
799 llvm_unreachable("Attempting to get address of ODP entry!");
802 // Relocation masks following the #lo(value), #hi(value), #ha(value),
803 // #higher(value), #highera(value), #highest(value), and #highesta(value)
804 // macros defined in section 4.5.1. Relocation Types of the PPC-elf64abi
807 static inline uint16_t applyPPClo(uint64_t value) { return value & 0xffff; }
809 static inline uint16_t applyPPChi(uint64_t value) {
810 return (value >> 16) & 0xffff;
813 static inline uint16_t applyPPCha (uint64_t value) {
814 return ((value + 0x8000) >> 16) & 0xffff;
817 static inline uint16_t applyPPChigher(uint64_t value) {
818 return (value >> 32) & 0xffff;
821 static inline uint16_t applyPPChighera (uint64_t value) {
822 return ((value + 0x8000) >> 32) & 0xffff;
825 static inline uint16_t applyPPChighest(uint64_t value) {
826 return (value >> 48) & 0xffff;
829 static inline uint16_t applyPPChighesta (uint64_t value) {
830 return ((value + 0x8000) >> 48) & 0xffff;
833 void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section,
834 uint64_t Offset, uint64_t Value,
835 uint32_t Type, int64_t Addend) {
836 uint8_t *LocalAddress = Section.Address + Offset;
839 llvm_unreachable("Relocation type not implemented yet!");
841 case ELF::R_PPC64_ADDR16:
842 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
844 case ELF::R_PPC64_ADDR16_DS:
845 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
847 case ELF::R_PPC64_ADDR16_LO:
848 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
850 case ELF::R_PPC64_ADDR16_LO_DS:
851 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
853 case ELF::R_PPC64_ADDR16_HI:
854 writeInt16BE(LocalAddress, applyPPChi(Value + Addend));
856 case ELF::R_PPC64_ADDR16_HA:
857 writeInt16BE(LocalAddress, applyPPCha(Value + Addend));
859 case ELF::R_PPC64_ADDR16_HIGHER:
860 writeInt16BE(LocalAddress, applyPPChigher(Value + Addend));
862 case ELF::R_PPC64_ADDR16_HIGHERA:
863 writeInt16BE(LocalAddress, applyPPChighera(Value + Addend));
865 case ELF::R_PPC64_ADDR16_HIGHEST:
866 writeInt16BE(LocalAddress, applyPPChighest(Value + Addend));
868 case ELF::R_PPC64_ADDR16_HIGHESTA:
869 writeInt16BE(LocalAddress, applyPPChighesta(Value + Addend));
871 case ELF::R_PPC64_ADDR14: {
872 assert(((Value + Addend) & 3) == 0);
873 // Preserve the AA/LK bits in the branch instruction
874 uint8_t aalk = *(LocalAddress + 3);
875 writeInt16BE(LocalAddress + 2, (aalk & 3) | ((Value + Addend) & 0xfffc));
877 case ELF::R_PPC64_REL16_LO: {
878 uint64_t FinalAddress = (Section.LoadAddress + Offset);
879 uint64_t Delta = Value - FinalAddress + Addend;
880 writeInt16BE(LocalAddress, applyPPClo(Delta));
882 case ELF::R_PPC64_REL16_HI: {
883 uint64_t FinalAddress = (Section.LoadAddress + Offset);
884 uint64_t Delta = Value - FinalAddress + Addend;
885 writeInt16BE(LocalAddress, applyPPChi(Delta));
887 case ELF::R_PPC64_REL16_HA: {
888 uint64_t FinalAddress = (Section.LoadAddress + Offset);
889 uint64_t Delta = Value - FinalAddress + Addend;
890 writeInt16BE(LocalAddress, applyPPCha(Delta));
892 case ELF::R_PPC64_ADDR32: {
893 int32_t Result = static_cast<int32_t>(Value + Addend);
894 if (SignExtend32<32>(Result) != Result)
895 llvm_unreachable("Relocation R_PPC64_ADDR32 overflow");
896 writeInt32BE(LocalAddress, Result);
898 case ELF::R_PPC64_REL24: {
899 uint64_t FinalAddress = (Section.LoadAddress + Offset);
900 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
901 if (SignExtend32<24>(delta) != delta)
902 llvm_unreachable("Relocation R_PPC64_REL24 overflow");
903 // Generates a 'bl <address>' instruction
904 writeInt32BE(LocalAddress, 0x48000001 | (delta & 0x03FFFFFC));
906 case ELF::R_PPC64_REL32: {
907 uint64_t FinalAddress = (Section.LoadAddress + Offset);
908 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
909 if (SignExtend32<32>(delta) != delta)
910 llvm_unreachable("Relocation R_PPC64_REL32 overflow");
911 writeInt32BE(LocalAddress, delta);
913 case ELF::R_PPC64_REL64: {
914 uint64_t FinalAddress = (Section.LoadAddress + Offset);
915 uint64_t Delta = Value - FinalAddress + Addend;
916 writeInt64BE(LocalAddress, Delta);
918 case ELF::R_PPC64_ADDR64:
919 writeInt64BE(LocalAddress, Value + Addend);
924 void RuntimeDyldELF::resolveSystemZRelocation(const SectionEntry &Section,
925 uint64_t Offset, uint64_t Value,
926 uint32_t Type, int64_t Addend) {
927 uint8_t *LocalAddress = Section.Address + Offset;
930 llvm_unreachable("Relocation type not implemented yet!");
932 case ELF::R_390_PC16DBL:
933 case ELF::R_390_PLT16DBL: {
934 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
935 assert(int16_t(Delta / 2) * 2 == Delta && "R_390_PC16DBL overflow");
936 writeInt16BE(LocalAddress, Delta / 2);
939 case ELF::R_390_PC32DBL:
940 case ELF::R_390_PLT32DBL: {
941 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
942 assert(int32_t(Delta / 2) * 2 == Delta && "R_390_PC32DBL overflow");
943 writeInt32BE(LocalAddress, Delta / 2);
946 case ELF::R_390_PC32: {
947 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
948 assert(int32_t(Delta) == Delta && "R_390_PC32 overflow");
949 writeInt32BE(LocalAddress, Delta);
953 writeInt64BE(LocalAddress, Value + Addend);
958 // The target location for the relocation is described by RE.SectionID and
959 // RE.Offset. RE.SectionID can be used to find the SectionEntry. Each
960 // SectionEntry has three members describing its location.
961 // SectionEntry::Address is the address at which the section has been loaded
962 // into memory in the current (host) process. SectionEntry::LoadAddress is the
963 // address that the section will have in the target process.
964 // SectionEntry::ObjAddress is the address of the bits for this section in the
965 // original emitted object image (also in the current address space).
967 // Relocations will be applied as if the section were loaded at
968 // SectionEntry::LoadAddress, but they will be applied at an address based
969 // on SectionEntry::Address. SectionEntry::ObjAddress will be used to refer to
970 // Target memory contents if they are required for value calculations.
972 // The Value parameter here is the load address of the symbol for the
973 // relocation to be applied. For relocations which refer to symbols in the
974 // current object Value will be the LoadAddress of the section in which
975 // the symbol resides (RE.Addend provides additional information about the
976 // symbol location). For external symbols, Value will be the address of the
977 // symbol in the target address space.
978 void RuntimeDyldELF::resolveRelocation(const RelocationEntry &RE,
980 const SectionEntry &Section = Sections[RE.SectionID];
981 return resolveRelocation(Section, RE.Offset, Value, RE.RelType, RE.Addend,
982 RE.SymOffset, RE.SectionID);
985 void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section,
986 uint64_t Offset, uint64_t Value,
987 uint32_t Type, int64_t Addend,
988 uint64_t SymOffset, SID SectionID) {
991 resolveX86_64Relocation(Section, Offset, Value, Type, Addend, SymOffset);
994 resolveX86Relocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
995 (uint32_t)(Addend & 0xffffffffL));
997 case Triple::aarch64:
998 case Triple::aarch64_be:
999 resolveAArch64Relocation(Section, Offset, Value, Type, Addend);
1001 case Triple::arm: // Fall through.
1004 case Triple::thumbeb:
1005 resolveARMRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
1006 (uint32_t)(Addend & 0xffffffffL));
1008 case Triple::mips: // Fall through.
1009 case Triple::mipsel:
1010 case Triple::mips64:
1011 case Triple::mips64el:
1013 resolveMIPSRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL),
1014 Type, (uint32_t)(Addend & 0xffffffffL));
1015 else if (IsMipsN64ABI)
1016 resolveMIPS64Relocation(Section, Offset, Value, Type, Addend, SymOffset,
1019 llvm_unreachable("Mips ABI not handled");
1021 case Triple::ppc64: // Fall through.
1022 case Triple::ppc64le:
1023 resolvePPC64Relocation(Section, Offset, Value, Type, Addend);
1025 case Triple::systemz:
1026 resolveSystemZRelocation(Section, Offset, Value, Type, Addend);
1029 llvm_unreachable("Unsupported CPU type!");
1033 void *RuntimeDyldELF::computePlaceholderAddress(unsigned SectionID, uint64_t Offset) const {
1034 return (void*)(Sections[SectionID].ObjAddress + Offset);
1037 void RuntimeDyldELF::processSimpleRelocation(unsigned SectionID, uint64_t Offset, unsigned RelType, RelocationValueRef Value) {
1038 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend, Value.Offset);
1039 if (Value.SymbolName)
1040 addRelocationForSymbol(RE, Value.SymbolName);
1042 addRelocationForSection(RE, Value.SectionID);
1045 relocation_iterator RuntimeDyldELF::processRelocationRef(
1046 unsigned SectionID, relocation_iterator RelI,
1047 const ObjectFile &Obj,
1048 ObjSectionToIDMap &ObjSectionToID,
1051 Check(RelI->getType(RelType));
1053 Check(getELFRelocationAddend(*RelI, Addend));
1054 symbol_iterator Symbol = RelI->getSymbol();
1056 // Obtain the symbol name which is referenced in the relocation
1057 StringRef TargetName;
1058 if (Symbol != Obj.symbol_end())
1059 Symbol->getName(TargetName);
1060 DEBUG(dbgs() << "\t\tRelType: " << RelType << " Addend: " << Addend
1061 << " TargetName: " << TargetName << "\n");
1062 RelocationValueRef Value;
1063 // First search for the symbol in the local symbol table
1064 SymbolRef::Type SymType = SymbolRef::ST_Unknown;
1066 // Search for the symbol in the global symbol table
1067 RTDyldSymbolTable::const_iterator gsi = GlobalSymbolTable.end();
1068 if (Symbol != Obj.symbol_end()) {
1069 gsi = GlobalSymbolTable.find(TargetName.data());
1070 Symbol->getType(SymType);
1072 if (gsi != GlobalSymbolTable.end()) {
1073 const auto &SymInfo = gsi->second;
1074 Value.SectionID = SymInfo.getSectionID();
1075 Value.Offset = SymInfo.getOffset();
1076 Value.Addend = SymInfo.getOffset() + Addend;
1079 case SymbolRef::ST_Debug: {
1080 // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously
1081 // and can be changed by another developers. Maybe best way is add
1082 // a new symbol type ST_Section to SymbolRef and use it.
1083 section_iterator si(Obj.section_end());
1084 Symbol->getSection(si);
1085 if (si == Obj.section_end())
1086 llvm_unreachable("Symbol section not found, bad object file format!");
1087 DEBUG(dbgs() << "\t\tThis is section symbol\n");
1088 bool isCode = si->isText();
1089 Value.SectionID = findOrEmitSection(Obj, (*si), isCode, ObjSectionToID);
1090 Value.Addend = Addend;
1093 case SymbolRef::ST_Data:
1094 case SymbolRef::ST_Unknown: {
1095 Value.SymbolName = TargetName.data();
1096 Value.Addend = Addend;
1098 // Absolute relocations will have a zero symbol ID (STN_UNDEF), which
1099 // will manifest here as a NULL symbol name.
1100 // We can set this as a valid (but empty) symbol name, and rely
1101 // on addRelocationForSymbol to handle this.
1102 if (!Value.SymbolName)
1103 Value.SymbolName = "";
1107 llvm_unreachable("Unresolved symbol type!");
1113 Check(RelI->getOffset(Offset));
1115 DEBUG(dbgs() << "\t\tSectionID: " << SectionID << " Offset: " << Offset
1117 if ((Arch == Triple::aarch64 || Arch == Triple::aarch64_be) &&
1118 (RelType == ELF::R_AARCH64_CALL26 || RelType == ELF::R_AARCH64_JUMP26)) {
1119 // This is an AArch64 branch relocation, need to use a stub function.
1120 DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation.");
1121 SectionEntry &Section = Sections[SectionID];
1123 // Look for an existing stub.
1124 StubMap::const_iterator i = Stubs.find(Value);
1125 if (i != Stubs.end()) {
1126 resolveRelocation(Section, Offset, (uint64_t)Section.Address + i->second,
1128 DEBUG(dbgs() << " Stub function found\n");
1130 // Create a new stub function.
1131 DEBUG(dbgs() << " Create a new stub function\n");
1132 Stubs[Value] = Section.StubOffset;
1133 uint8_t *StubTargetAddr =
1134 createStubFunction(Section.Address + Section.StubOffset);
1136 RelocationEntry REmovz_g3(SectionID, StubTargetAddr - Section.Address,
1137 ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend);
1138 RelocationEntry REmovk_g2(SectionID, StubTargetAddr - Section.Address + 4,
1139 ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend);
1140 RelocationEntry REmovk_g1(SectionID, StubTargetAddr - Section.Address + 8,
1141 ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend);
1142 RelocationEntry REmovk_g0(SectionID,
1143 StubTargetAddr - Section.Address + 12,
1144 ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend);
1146 if (Value.SymbolName) {
1147 addRelocationForSymbol(REmovz_g3, Value.SymbolName);
1148 addRelocationForSymbol(REmovk_g2, Value.SymbolName);
1149 addRelocationForSymbol(REmovk_g1, Value.SymbolName);
1150 addRelocationForSymbol(REmovk_g0, Value.SymbolName);
1152 addRelocationForSection(REmovz_g3, Value.SectionID);
1153 addRelocationForSection(REmovk_g2, Value.SectionID);
1154 addRelocationForSection(REmovk_g1, Value.SectionID);
1155 addRelocationForSection(REmovk_g0, Value.SectionID);
1157 resolveRelocation(Section, Offset,
1158 (uint64_t)Section.Address + Section.StubOffset, RelType,
1160 Section.StubOffset += getMaxStubSize();
1162 } else if (Arch == Triple::arm) {
1163 if (RelType == ELF::R_ARM_PC24 || RelType == ELF::R_ARM_CALL ||
1164 RelType == ELF::R_ARM_JUMP24) {
1165 // This is an ARM branch relocation, need to use a stub function.
1166 DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.");
1167 SectionEntry &Section = Sections[SectionID];
1169 // Look for an existing stub.
1170 StubMap::const_iterator i = Stubs.find(Value);
1171 if (i != Stubs.end()) {
1172 resolveRelocation(Section, Offset, (uint64_t)Section.Address + i->second,
1174 DEBUG(dbgs() << " Stub function found\n");
1176 // Create a new stub function.
1177 DEBUG(dbgs() << " Create a new stub function\n");
1178 Stubs[Value] = Section.StubOffset;
1179 uint8_t *StubTargetAddr =
1180 createStubFunction(Section.Address + Section.StubOffset);
1181 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1182 ELF::R_ARM_ABS32, Value.Addend);
1183 if (Value.SymbolName)
1184 addRelocationForSymbol(RE, Value.SymbolName);
1186 addRelocationForSection(RE, Value.SectionID);
1188 resolveRelocation(Section, Offset,
1189 (uint64_t)Section.Address + Section.StubOffset, RelType,
1191 Section.StubOffset += getMaxStubSize();
1194 uint32_t *Placeholder =
1195 reinterpret_cast<uint32_t*>(computePlaceholderAddress(SectionID, Offset));
1196 if (RelType == ELF::R_ARM_PREL31 || RelType == ELF::R_ARM_TARGET1 ||
1197 RelType == ELF::R_ARM_ABS32) {
1198 Value.Addend += *Placeholder;
1199 } else if (RelType == ELF::R_ARM_MOVW_ABS_NC || RelType == ELF::R_ARM_MOVT_ABS) {
1200 // See ELF for ARM documentation
1201 Value.Addend += (int16_t)((*Placeholder & 0xFFF) | (((*Placeholder >> 16) & 0xF) << 12));
1203 processSimpleRelocation(SectionID, Offset, RelType, Value);
1205 } else if (IsMipsO32ABI) {
1206 uint32_t *Placeholder = reinterpret_cast<uint32_t*>(computePlaceholderAddress(SectionID, Offset));
1207 if (RelType == ELF::R_MIPS_26) {
1208 // This is an Mips branch relocation, need to use a stub function.
1209 DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
1210 SectionEntry &Section = Sections[SectionID];
1212 // Extract the addend from the instruction.
1213 // We shift up by two since the Value will be down shifted again
1214 // when applying the relocation.
1215 uint32_t Addend = ((*Placeholder) & 0x03ffffff) << 2;
1217 Value.Addend += Addend;
1219 // Look up for existing stub.
1220 StubMap::const_iterator i = Stubs.find(Value);
1221 if (i != Stubs.end()) {
1222 RelocationEntry RE(SectionID, Offset, RelType, i->second);
1223 addRelocationForSection(RE, SectionID);
1224 DEBUG(dbgs() << " Stub function found\n");
1226 // Create a new stub function.
1227 DEBUG(dbgs() << " Create a new stub function\n");
1228 Stubs[Value] = Section.StubOffset;
1229 uint8_t *StubTargetAddr =
1230 createStubFunction(Section.Address + Section.StubOffset);
1232 // Creating Hi and Lo relocations for the filled stub instructions.
1233 RelocationEntry REHi(SectionID, StubTargetAddr - Section.Address,
1234 ELF::R_MIPS_HI16, Value.Addend);
1235 RelocationEntry RELo(SectionID, StubTargetAddr - Section.Address + 4,
1236 ELF::R_MIPS_LO16, Value.Addend);
1238 if (Value.SymbolName) {
1239 addRelocationForSymbol(REHi, Value.SymbolName);
1240 addRelocationForSymbol(RELo, Value.SymbolName);
1243 addRelocationForSection(REHi, Value.SectionID);
1244 addRelocationForSection(RELo, Value.SectionID);
1247 RelocationEntry RE(SectionID, Offset, RelType, Section.StubOffset);
1248 addRelocationForSection(RE, SectionID);
1249 Section.StubOffset += getMaxStubSize();
1252 if (RelType == ELF::R_MIPS_HI16)
1253 Value.Addend += ((*Placeholder) & 0x0000ffff) << 16;
1254 else if (RelType == ELF::R_MIPS_LO16)
1255 Value.Addend += ((*Placeholder) & 0x0000ffff);
1256 else if (RelType == ELF::R_MIPS_32)
1257 Value.Addend += *Placeholder;
1258 processSimpleRelocation(SectionID, Offset, RelType, Value);
1260 } else if (IsMipsN64ABI) {
1261 uint32_t r_type = RelType & 0xff;
1262 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1263 if (r_type == ELF::R_MIPS_CALL16 || r_type == ELF::R_MIPS_GOT_PAGE
1264 || r_type == ELF::R_MIPS_GOT_DISP) {
1265 StringMap<uint64_t>::iterator i = GOTSymbolOffsets.find(TargetName);
1266 if (i != GOTSymbolOffsets.end())
1267 RE.SymOffset = i->second;
1269 RE.SymOffset = allocateGOTEntries(SectionID, 1);
1270 GOTSymbolOffsets[TargetName] = RE.SymOffset;
1273 if (Value.SymbolName)
1274 addRelocationForSymbol(RE, Value.SymbolName);
1276 addRelocationForSection(RE, Value.SectionID);
1277 } else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) {
1278 if (RelType == ELF::R_PPC64_REL24) {
1279 // Determine ABI variant in use for this object.
1280 unsigned AbiVariant;
1281 Obj.getPlatformFlags(AbiVariant);
1282 AbiVariant &= ELF::EF_PPC64_ABI;
1283 // A PPC branch relocation will need a stub function if the target is
1284 // an external symbol (Symbol::ST_Unknown) or if the target address
1285 // is not within the signed 24-bits branch address.
1286 SectionEntry &Section = Sections[SectionID];
1287 uint8_t *Target = Section.Address + Offset;
1288 bool RangeOverflow = false;
1289 if (SymType != SymbolRef::ST_Unknown) {
1290 if (AbiVariant != 2) {
1291 // In the ELFv1 ABI, a function call may point to the .opd entry,
1292 // so the final symbol value is calculated based on the relocation
1293 // values in the .opd section.
1294 findOPDEntrySection(Obj, ObjSectionToID, Value);
1296 // In the ELFv2 ABI, a function symbol may provide a local entry
1297 // point, which must be used for direct calls.
1299 Symbol->getOther(SymOther);
1300 Value.Addend += ELF::decodePPC64LocalEntryOffset(SymOther);
1302 uint8_t *RelocTarget = Sections[Value.SectionID].Address + Value.Addend;
1303 int32_t delta = static_cast<int32_t>(Target - RelocTarget);
1304 // If it is within 24-bits branch range, just set the branch target
1305 if (SignExtend32<24>(delta) == delta) {
1306 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1307 if (Value.SymbolName)
1308 addRelocationForSymbol(RE, Value.SymbolName);
1310 addRelocationForSection(RE, Value.SectionID);
1312 RangeOverflow = true;
1315 if (SymType == SymbolRef::ST_Unknown || RangeOverflow) {
1316 // It is an external symbol (SymbolRef::ST_Unknown) or within a range
1317 // larger than 24-bits.
1318 StubMap::const_iterator i = Stubs.find(Value);
1319 if (i != Stubs.end()) {
1320 // Symbol function stub already created, just relocate to it
1321 resolveRelocation(Section, Offset,
1322 (uint64_t)Section.Address + i->second, RelType, 0);
1323 DEBUG(dbgs() << " Stub function found\n");
1325 // Create a new stub function.
1326 DEBUG(dbgs() << " Create a new stub function\n");
1327 Stubs[Value] = Section.StubOffset;
1328 uint8_t *StubTargetAddr =
1329 createStubFunction(Section.Address + Section.StubOffset,
1331 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1332 ELF::R_PPC64_ADDR64, Value.Addend);
1334 // Generates the 64-bits address loads as exemplified in section
1335 // 4.5.1 in PPC64 ELF ABI. Note that the relocations need to
1336 // apply to the low part of the instructions, so we have to update
1337 // the offset according to the target endianness.
1338 uint64_t StubRelocOffset = StubTargetAddr - Section.Address;
1339 if (!IsTargetLittleEndian)
1340 StubRelocOffset += 2;
1342 RelocationEntry REhst(SectionID, StubRelocOffset + 0,
1343 ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend);
1344 RelocationEntry REhr(SectionID, StubRelocOffset + 4,
1345 ELF::R_PPC64_ADDR16_HIGHER, Value.Addend);
1346 RelocationEntry REh(SectionID, StubRelocOffset + 12,
1347 ELF::R_PPC64_ADDR16_HI, Value.Addend);
1348 RelocationEntry REl(SectionID, StubRelocOffset + 16,
1349 ELF::R_PPC64_ADDR16_LO, Value.Addend);
1351 if (Value.SymbolName) {
1352 addRelocationForSymbol(REhst, Value.SymbolName);
1353 addRelocationForSymbol(REhr, Value.SymbolName);
1354 addRelocationForSymbol(REh, Value.SymbolName);
1355 addRelocationForSymbol(REl, Value.SymbolName);
1357 addRelocationForSection(REhst, Value.SectionID);
1358 addRelocationForSection(REhr, Value.SectionID);
1359 addRelocationForSection(REh, Value.SectionID);
1360 addRelocationForSection(REl, Value.SectionID);
1363 resolveRelocation(Section, Offset,
1364 (uint64_t)Section.Address + Section.StubOffset,
1366 Section.StubOffset += getMaxStubSize();
1368 if (SymType == SymbolRef::ST_Unknown) {
1369 // Restore the TOC for external calls
1370 if (AbiVariant == 2)
1371 writeInt32BE(Target + 4, 0xE8410018); // ld r2,28(r1)
1373 writeInt32BE(Target + 4, 0xE8410028); // ld r2,40(r1)
1376 } else if (RelType == ELF::R_PPC64_TOC16 ||
1377 RelType == ELF::R_PPC64_TOC16_DS ||
1378 RelType == ELF::R_PPC64_TOC16_LO ||
1379 RelType == ELF::R_PPC64_TOC16_LO_DS ||
1380 RelType == ELF::R_PPC64_TOC16_HI ||
1381 RelType == ELF::R_PPC64_TOC16_HA) {
1382 // These relocations are supposed to subtract the TOC address from
1383 // the final value. This does not fit cleanly into the RuntimeDyld
1384 // scheme, since there may be *two* sections involved in determining
1385 // the relocation value (the section of the symbol refered to by the
1386 // relocation, and the TOC section associated with the current module).
1388 // Fortunately, these relocations are currently only ever generated
1389 // refering to symbols that themselves reside in the TOC, which means
1390 // that the two sections are actually the same. Thus they cancel out
1391 // and we can immediately resolve the relocation right now.
1393 case ELF::R_PPC64_TOC16: RelType = ELF::R_PPC64_ADDR16; break;
1394 case ELF::R_PPC64_TOC16_DS: RelType = ELF::R_PPC64_ADDR16_DS; break;
1395 case ELF::R_PPC64_TOC16_LO: RelType = ELF::R_PPC64_ADDR16_LO; break;
1396 case ELF::R_PPC64_TOC16_LO_DS: RelType = ELF::R_PPC64_ADDR16_LO_DS; break;
1397 case ELF::R_PPC64_TOC16_HI: RelType = ELF::R_PPC64_ADDR16_HI; break;
1398 case ELF::R_PPC64_TOC16_HA: RelType = ELF::R_PPC64_ADDR16_HA; break;
1399 default: llvm_unreachable("Wrong relocation type.");
1402 RelocationValueRef TOCValue;
1403 findPPC64TOCSection(Obj, ObjSectionToID, TOCValue);
1404 if (Value.SymbolName || Value.SectionID != TOCValue.SectionID)
1405 llvm_unreachable("Unsupported TOC relocation.");
1406 Value.Addend -= TOCValue.Addend;
1407 resolveRelocation(Sections[SectionID], Offset, Value.Addend, RelType, 0);
1409 // There are two ways to refer to the TOC address directly: either
1410 // via a ELF::R_PPC64_TOC relocation (where both symbol and addend are
1411 // ignored), or via any relocation that refers to the magic ".TOC."
1412 // symbols (in which case the addend is respected).
1413 if (RelType == ELF::R_PPC64_TOC) {
1414 RelType = ELF::R_PPC64_ADDR64;
1415 findPPC64TOCSection(Obj, ObjSectionToID, Value);
1416 } else if (TargetName == ".TOC.") {
1417 findPPC64TOCSection(Obj, ObjSectionToID, Value);
1418 Value.Addend += Addend;
1421 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1423 if (Value.SymbolName)
1424 addRelocationForSymbol(RE, Value.SymbolName);
1426 addRelocationForSection(RE, Value.SectionID);
1428 } else if (Arch == Triple::systemz &&
1429 (RelType == ELF::R_390_PLT32DBL || RelType == ELF::R_390_GOTENT)) {
1430 // Create function stubs for both PLT and GOT references, regardless of
1431 // whether the GOT reference is to data or code. The stub contains the
1432 // full address of the symbol, as needed by GOT references, and the
1433 // executable part only adds an overhead of 8 bytes.
1435 // We could try to conserve space by allocating the code and data
1436 // parts of the stub separately. However, as things stand, we allocate
1437 // a stub for every relocation, so using a GOT in JIT code should be
1438 // no less space efficient than using an explicit constant pool.
1439 DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation.");
1440 SectionEntry &Section = Sections[SectionID];
1442 // Look for an existing stub.
1443 StubMap::const_iterator i = Stubs.find(Value);
1444 uintptr_t StubAddress;
1445 if (i != Stubs.end()) {
1446 StubAddress = uintptr_t(Section.Address) + i->second;
1447 DEBUG(dbgs() << " Stub function found\n");
1449 // Create a new stub function.
1450 DEBUG(dbgs() << " Create a new stub function\n");
1452 uintptr_t BaseAddress = uintptr_t(Section.Address);
1453 uintptr_t StubAlignment = getStubAlignment();
1454 StubAddress = (BaseAddress + Section.StubOffset + StubAlignment - 1) &
1456 unsigned StubOffset = StubAddress - BaseAddress;
1458 Stubs[Value] = StubOffset;
1459 createStubFunction((uint8_t *)StubAddress);
1460 RelocationEntry RE(SectionID, StubOffset + 8, ELF::R_390_64,
1462 if (Value.SymbolName)
1463 addRelocationForSymbol(RE, Value.SymbolName);
1465 addRelocationForSection(RE, Value.SectionID);
1466 Section.StubOffset = StubOffset + getMaxStubSize();
1469 if (RelType == ELF::R_390_GOTENT)
1470 resolveRelocation(Section, Offset, StubAddress + 8, ELF::R_390_PC32DBL,
1473 resolveRelocation(Section, Offset, StubAddress, RelType, Addend);
1474 } else if (Arch == Triple::x86_64) {
1475 if (RelType == ELF::R_X86_64_PLT32) {
1476 // The way the PLT relocations normally work is that the linker allocates
1478 // PLT and this relocation makes a PC-relative call into the PLT. The PLT
1479 // entry will then jump to an address provided by the GOT. On first call,
1481 // GOT address will point back into PLT code that resolves the symbol. After
1482 // the first call, the GOT entry points to the actual function.
1484 // For local functions we're ignoring all of that here and just replacing
1485 // the PLT32 relocation type with PC32, which will translate the relocation
1486 // into a PC-relative call directly to the function. For external symbols we
1487 // can't be sure the function will be within 2^32 bytes of the call site, so
1488 // we need to create a stub, which calls into the GOT. This case is
1489 // equivalent to the usual PLT implementation except that we use the stub
1490 // mechanism in RuntimeDyld (which puts stubs at the end of the section)
1491 // rather than allocating a PLT section.
1492 if (Value.SymbolName) {
1493 // This is a call to an external function.
1494 // Look for an existing stub.
1495 SectionEntry &Section = Sections[SectionID];
1496 StubMap::const_iterator i = Stubs.find(Value);
1497 uintptr_t StubAddress;
1498 if (i != Stubs.end()) {
1499 StubAddress = uintptr_t(Section.Address) + i->second;
1500 DEBUG(dbgs() << " Stub function found\n");
1502 // Create a new stub function (equivalent to a PLT entry).
1503 DEBUG(dbgs() << " Create a new stub function\n");
1505 uintptr_t BaseAddress = uintptr_t(Section.Address);
1506 uintptr_t StubAlignment = getStubAlignment();
1507 StubAddress = (BaseAddress + Section.StubOffset + StubAlignment - 1) &
1509 unsigned StubOffset = StubAddress - BaseAddress;
1510 Stubs[Value] = StubOffset;
1511 createStubFunction((uint8_t *)StubAddress);
1513 // Bump our stub offset counter
1514 Section.StubOffset = StubOffset + getMaxStubSize();
1516 // Allocate a GOT Entry
1517 uint64_t GOTOffset = allocateGOTEntries(SectionID, 1);
1519 // The load of the GOT address has an addend of -4
1520 resolveGOTOffsetRelocation(SectionID, StubOffset + 2, GOTOffset - 4);
1522 // Fill in the value of the symbol we're targeting into the GOT
1523 addRelocationForSymbol(computeGOTOffsetRE(SectionID,GOTOffset,0,ELF::R_X86_64_64),
1527 // Make the target call a call into the stub table.
1528 resolveRelocation(Section, Offset, StubAddress, ELF::R_X86_64_PC32,
1531 RelocationEntry RE(SectionID, Offset, ELF::R_X86_64_PC32, Value.Addend,
1533 addRelocationForSection(RE, Value.SectionID);
1535 } else if (RelType == ELF::R_X86_64_GOTPCREL) {
1536 uint64_t GOTOffset = allocateGOTEntries(SectionID, 1);
1537 resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend);
1539 // Fill in the value of the symbol we're targeting into the GOT
1540 RelocationEntry RE = computeGOTOffsetRE(SectionID, GOTOffset, Value.Offset, ELF::R_X86_64_64);
1541 if (Value.SymbolName)
1542 addRelocationForSymbol(RE, Value.SymbolName);
1544 addRelocationForSection(RE, Value.SectionID);
1545 } else if (RelType == ELF::R_X86_64_PC32) {
1546 Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset));
1547 processSimpleRelocation(SectionID, Offset, RelType, Value);
1548 } else if (RelType == ELF::R_X86_64_PC64) {
1549 Value.Addend += support::ulittle64_t::ref(computePlaceholderAddress(SectionID, Offset));
1550 processSimpleRelocation(SectionID, Offset, RelType, Value);
1552 processSimpleRelocation(SectionID, Offset, RelType, Value);
1555 if (Arch == Triple::x86) {
1556 Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset));
1558 processSimpleRelocation(SectionID, Offset, RelType, Value);
1563 size_t RuntimeDyldELF::getGOTEntrySize() {
1564 // We don't use the GOT in all of these cases, but it's essentially free
1565 // to put them all here.
1568 case Triple::x86_64:
1569 case Triple::aarch64:
1570 case Triple::aarch64_be:
1572 case Triple::ppc64le:
1573 case Triple::systemz:
1574 Result = sizeof(uint64_t);
1579 Result = sizeof(uint32_t);
1582 case Triple::mipsel:
1583 case Triple::mips64:
1584 case Triple::mips64el:
1586 Result = sizeof(uint32_t);
1587 else if (IsMipsN64ABI)
1588 Result = sizeof(uint64_t);
1590 llvm_unreachable("Mips ABI not handled");
1593 llvm_unreachable("Unsupported CPU type!");
1598 uint64_t RuntimeDyldELF::allocateGOTEntries(unsigned SectionID, unsigned no)
1600 (void)SectionID; // The GOT Section is the same for all section in the object file
1601 if (GOTSectionID == 0) {
1602 GOTSectionID = Sections.size();
1603 // Reserve a section id. We'll allocate the section later
1604 // once we know the total size
1605 Sections.push_back(SectionEntry(".got", 0, 0, 0));
1607 uint64_t StartOffset = CurrentGOTIndex * getGOTEntrySize();
1608 CurrentGOTIndex += no;
1612 void RuntimeDyldELF::resolveGOTOffsetRelocation(unsigned SectionID, uint64_t Offset, uint64_t GOTOffset)
1614 // Fill in the relative address of the GOT Entry into the stub
1615 RelocationEntry GOTRE(SectionID, Offset, ELF::R_X86_64_PC32, GOTOffset);
1616 addRelocationForSection(GOTRE, GOTSectionID);
1619 RelocationEntry RuntimeDyldELF::computeGOTOffsetRE(unsigned SectionID, uint64_t GOTOffset, uint64_t SymbolOffset,
1622 (void)SectionID; // The GOT Section is the same for all section in the object file
1623 return RelocationEntry(GOTSectionID, GOTOffset, Type, SymbolOffset);
1626 void RuntimeDyldELF::finalizeLoad(const ObjectFile &Obj,
1627 ObjSectionToIDMap &SectionMap) {
1628 // If necessary, allocate the global offset table
1629 if (GOTSectionID != 0) {
1630 // Allocate memory for the section
1631 size_t TotalSize = CurrentGOTIndex * getGOTEntrySize();
1632 uint8_t *Addr = MemMgr.allocateDataSection(TotalSize, getGOTEntrySize(),
1633 GOTSectionID, ".got", false);
1635 report_fatal_error("Unable to allocate memory for GOT!");
1637 Sections[GOTSectionID] = SectionEntry(".got", Addr, TotalSize, 0);
1640 Checker->registerSection(Obj.getFileName(), GOTSectionID);
1642 // For now, initialize all GOT entries to zero. We'll fill them in as
1643 // needed when GOT-based relocations are applied.
1644 memset(Addr, 0, TotalSize);
1646 // To correctly resolve Mips GOT relocations, we need a mapping from
1647 // object's sections to GOTs.
1648 for (section_iterator SI = Obj.section_begin(), SE = Obj.section_end();
1650 if (SI->relocation_begin() != SI->relocation_end()) {
1651 section_iterator RelocatedSection = SI->getRelocatedSection();
1652 ObjSectionToIDMap::iterator i = SectionMap.find(*RelocatedSection);
1653 assert (i != SectionMap.end());
1654 SectionToGOTMap[i->second] = GOTSectionID;
1657 GOTSymbolOffsets.clear();
1661 // Look for and record the EH frame section.
1662 ObjSectionToIDMap::iterator i, e;
1663 for (i = SectionMap.begin(), e = SectionMap.end(); i != e; ++i) {
1664 const SectionRef &Section = i->first;
1666 Section.getName(Name);
1667 if (Name == ".eh_frame") {
1668 UnregisteredEHFrameSections.push_back(i->second);
1674 CurrentGOTIndex = 0;
1677 bool RuntimeDyldELF::isCompatibleFile(const object::ObjectFile &Obj) const {