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 + Addend - FinalAddress, (uint8_t *)TargetPtr, 4);
521 void RuntimeDyldELF::setMipsABI(const ObjectFile &Obj) {
522 if (Arch == Triple::UnknownArch ||
523 !StringRef(Triple::getArchTypePrefix(Arch)).equals("mips")) {
524 IsMipsO32ABI = false;
525 IsMipsN64ABI = false;
529 Obj.getPlatformFlags(AbiVariant);
530 IsMipsO32ABI = AbiVariant & ELF::EF_MIPS_ABI_O32;
531 IsMipsN64ABI = Obj.getFileFormatName().equals("ELF64-mips");
532 if (AbiVariant & ELF::EF_MIPS_ABI2)
533 llvm_unreachable("Mips N32 ABI is not supported yet");
536 void RuntimeDyldELF::resolveMIPS64Relocation(const SectionEntry &Section,
537 uint64_t Offset, uint64_t Value,
538 uint32_t Type, int64_t Addend,
541 uint32_t r_type = Type & 0xff;
542 uint32_t r_type2 = (Type >> 8) & 0xff;
543 uint32_t r_type3 = (Type >> 16) & 0xff;
545 // RelType is used to keep information for which relocation type we are
546 // applying relocation.
547 uint32_t RelType = r_type;
548 int64_t CalculatedValue = evaluateMIPS64Relocation(Section, Offset, Value,
550 SymOffset, SectionID);
551 if (r_type2 != ELF::R_MIPS_NONE) {
553 CalculatedValue = evaluateMIPS64Relocation(Section, Offset, 0, RelType,
554 CalculatedValue, SymOffset,
557 if (r_type3 != ELF::R_MIPS_NONE) {
559 CalculatedValue = evaluateMIPS64Relocation(Section, Offset, 0, RelType,
560 CalculatedValue, SymOffset,
563 applyMIPS64Relocation(Section.Address + Offset, CalculatedValue, RelType);
567 RuntimeDyldELF::evaluateMIPS64Relocation(const SectionEntry &Section,
568 uint64_t Offset, uint64_t Value,
569 uint32_t Type, int64_t Addend,
570 uint64_t SymOffset, SID SectionID) {
572 DEBUG(dbgs() << "evaluateMIPS64Relocation, LocalAddress: 0x"
573 << format("%llx", Section.Address + Offset)
574 << " FinalAddress: 0x"
575 << format("%llx", Section.LoadAddress + Offset)
576 << " Value: 0x" << format("%llx", Value) << " Type: 0x"
577 << format("%x", Type) << " Addend: 0x" << format("%llx", Addend)
578 << " SymOffset: " << format("%x", SymOffset)
583 llvm_unreachable("Not implemented relocation type!");
585 case ELF::R_MIPS_JALR:
586 case ELF::R_MIPS_NONE:
590 return Value + Addend;
592 return ((Value + Addend) >> 2) & 0x3ffffff;
593 case ELF::R_MIPS_GPREL16: {
594 uint64_t GOTAddr = getSectionLoadAddress(SectionToGOTMap[SectionID]);
595 return Value + Addend - (GOTAddr + 0x7ff0);
597 case ELF::R_MIPS_SUB:
598 return Value - Addend;
599 case ELF::R_MIPS_HI16:
600 // Get the higher 16-bits. Also add 1 if bit 15 is 1.
601 return ((Value + Addend + 0x8000) >> 16) & 0xffff;
602 case ELF::R_MIPS_LO16:
603 return (Value + Addend) & 0xffff;
604 case ELF::R_MIPS_CALL16:
605 case ELF::R_MIPS_GOT_DISP:
606 case ELF::R_MIPS_GOT_PAGE: {
607 uint8_t *LocalGOTAddr =
608 getSectionAddress(SectionToGOTMap[SectionID]) + SymOffset;
609 uint64_t GOTEntry = readBytesUnaligned(LocalGOTAddr, 8);
612 if (Type == ELF::R_MIPS_GOT_PAGE)
613 Value = (Value + 0x8000) & ~0xffff;
616 assert(GOTEntry == Value &&
617 "GOT entry has two different addresses.");
619 writeBytesUnaligned(Value, LocalGOTAddr, 8);
621 return (SymOffset - 0x7ff0) & 0xffff;
623 case ELF::R_MIPS_GOT_OFST: {
624 int64_t page = (Value + Addend + 0x8000) & ~0xffff;
625 return (Value + Addend - page) & 0xffff;
627 case ELF::R_MIPS_GPREL32: {
628 uint64_t GOTAddr = getSectionLoadAddress(SectionToGOTMap[SectionID]);
629 return Value + Addend - (GOTAddr + 0x7ff0);
631 case ELF::R_MIPS_PC16: {
632 uint64_t FinalAddress = (Section.LoadAddress + Offset);
633 return ((Value + Addend - FinalAddress) >> 2) & 0xffff;
635 case ELF::R_MIPS_PC32: {
636 uint64_t FinalAddress = (Section.LoadAddress + Offset);
637 return Value + Addend - FinalAddress;
639 case ELF::R_MIPS_PC18_S3: {
640 uint64_t FinalAddress = (Section.LoadAddress + Offset);
641 return ((Value + Addend - ((FinalAddress | 7) ^ 7)) >> 3) & 0x3ffff;
643 case ELF::R_MIPS_PC19_S2: {
644 uint64_t FinalAddress = (Section.LoadAddress + Offset);
645 return ((Value + Addend - FinalAddress) >> 2) & 0x7ffff;
647 case ELF::R_MIPS_PC21_S2: {
648 uint64_t FinalAddress = (Section.LoadAddress + Offset);
649 return ((Value + Addend - FinalAddress) >> 2) & 0x1fffff;
651 case ELF::R_MIPS_PC26_S2: {
652 uint64_t FinalAddress = (Section.LoadAddress + Offset);
653 return ((Value + Addend - FinalAddress) >> 2) & 0x3ffffff;
655 case ELF::R_MIPS_PCHI16: {
656 uint64_t FinalAddress = (Section.LoadAddress + Offset);
657 return ((Value + Addend - FinalAddress + 0x8000) >> 16) & 0xffff;
659 case ELF::R_MIPS_PCLO16: {
660 uint64_t FinalAddress = (Section.LoadAddress + Offset);
661 return (Value + Addend - FinalAddress) & 0xffff;
667 void RuntimeDyldELF::applyMIPS64Relocation(uint8_t *TargetPtr,
668 int64_t CalculatedValue,
670 uint32_t Insn = readBytesUnaligned(TargetPtr, 4);
676 case ELF::R_MIPS_GPREL32:
677 case ELF::R_MIPS_PC32:
678 writeBytesUnaligned(CalculatedValue & 0xffffffff, TargetPtr, 4);
681 case ELF::R_MIPS_SUB:
682 writeBytesUnaligned(CalculatedValue, TargetPtr, 8);
685 case ELF::R_MIPS_PC26_S2:
686 Insn = (Insn & 0xfc000000) | CalculatedValue;
687 writeBytesUnaligned(Insn, TargetPtr, 4);
689 case ELF::R_MIPS_GPREL16:
690 Insn = (Insn & 0xffff0000) | (CalculatedValue & 0xffff);
691 writeBytesUnaligned(Insn, TargetPtr, 4);
693 case ELF::R_MIPS_HI16:
694 case ELF::R_MIPS_LO16:
695 case ELF::R_MIPS_PCHI16:
696 case ELF::R_MIPS_PCLO16:
697 case ELF::R_MIPS_PC16:
698 case ELF::R_MIPS_CALL16:
699 case ELF::R_MIPS_GOT_DISP:
700 case ELF::R_MIPS_GOT_PAGE:
701 case ELF::R_MIPS_GOT_OFST:
702 Insn = (Insn & 0xffff0000) | CalculatedValue;
703 writeBytesUnaligned(Insn, TargetPtr, 4);
705 case ELF::R_MIPS_PC18_S3:
706 Insn = (Insn & 0xfffc0000) | CalculatedValue;
707 writeBytesUnaligned(Insn, TargetPtr, 4);
709 case ELF::R_MIPS_PC19_S2:
710 Insn = (Insn & 0xfff80000) | CalculatedValue;
711 writeBytesUnaligned(Insn, TargetPtr, 4);
713 case ELF::R_MIPS_PC21_S2:
714 Insn = (Insn & 0xffe00000) | CalculatedValue;
715 writeBytesUnaligned(Insn, TargetPtr, 4);
720 // Return the .TOC. section and offset.
721 void RuntimeDyldELF::findPPC64TOCSection(const ELFObjectFileBase &Obj,
722 ObjSectionToIDMap &LocalSections,
723 RelocationValueRef &Rel) {
724 // Set a default SectionID in case we do not find a TOC section below.
725 // This may happen for references to TOC base base (sym@toc, .odp
726 // relocation) without a .toc directive. In this case just use the
727 // first section (which is usually the .odp) since the code won't
728 // reference the .toc base directly.
729 Rel.SymbolName = NULL;
732 // The TOC consists of sections .got, .toc, .tocbss, .plt in that
733 // order. The TOC starts where the first of these sections starts.
734 for (auto &Section: Obj.sections()) {
735 StringRef SectionName;
736 check(Section.getName(SectionName));
738 if (SectionName == ".got"
739 || SectionName == ".toc"
740 || SectionName == ".tocbss"
741 || SectionName == ".plt") {
742 Rel.SectionID = findOrEmitSection(Obj, Section, false, LocalSections);
747 // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000
748 // thus permitting a full 64 Kbytes segment.
752 // Returns the sections and offset associated with the ODP entry referenced
754 void RuntimeDyldELF::findOPDEntrySection(const ELFObjectFileBase &Obj,
755 ObjSectionToIDMap &LocalSections,
756 RelocationValueRef &Rel) {
757 // Get the ELF symbol value (st_value) to compare with Relocation offset in
759 for (section_iterator si = Obj.section_begin(), se = Obj.section_end();
761 section_iterator RelSecI = si->getRelocatedSection();
762 if (RelSecI == Obj.section_end())
765 StringRef RelSectionName;
766 check(RelSecI->getName(RelSectionName));
767 if (RelSectionName != ".opd")
770 for (relocation_iterator i = si->relocation_begin(),
771 e = si->relocation_end();
773 // The R_PPC64_ADDR64 relocation indicates the first field
776 check(i->getType(TypeFunc));
777 if (TypeFunc != ELF::R_PPC64_ADDR64) {
782 uint64_t TargetSymbolOffset;
783 symbol_iterator TargetSymbol = i->getSymbol();
784 check(i->getOffset(TargetSymbolOffset));
785 ErrorOr<int64_t> AddendOrErr =
786 Obj.getRelocationAddend(i->getRawDataRefImpl());
787 Check(AddendOrErr.getError());
788 int64_t Addend = *AddendOrErr;
794 // Just check if following relocation is a R_PPC64_TOC
796 check(i->getType(TypeTOC));
797 if (TypeTOC != ELF::R_PPC64_TOC)
800 // Finally compares the Symbol value and the target symbol offset
801 // to check if this .opd entry refers to the symbol the relocation
803 if (Rel.Addend != (int64_t)TargetSymbolOffset)
806 section_iterator tsi(Obj.section_end());
807 check(TargetSymbol->getSection(tsi));
808 bool IsCode = tsi->isText();
809 Rel.SectionID = findOrEmitSection(Obj, (*tsi), IsCode, LocalSections);
810 Rel.Addend = (intptr_t)Addend;
814 llvm_unreachable("Attempting to get address of ODP entry!");
817 // Relocation masks following the #lo(value), #hi(value), #ha(value),
818 // #higher(value), #highera(value), #highest(value), and #highesta(value)
819 // macros defined in section 4.5.1. Relocation Types of the PPC-elf64abi
822 static inline uint16_t applyPPClo(uint64_t value) { return value & 0xffff; }
824 static inline uint16_t applyPPChi(uint64_t value) {
825 return (value >> 16) & 0xffff;
828 static inline uint16_t applyPPCha (uint64_t value) {
829 return ((value + 0x8000) >> 16) & 0xffff;
832 static inline uint16_t applyPPChigher(uint64_t value) {
833 return (value >> 32) & 0xffff;
836 static inline uint16_t applyPPChighera (uint64_t value) {
837 return ((value + 0x8000) >> 32) & 0xffff;
840 static inline uint16_t applyPPChighest(uint64_t value) {
841 return (value >> 48) & 0xffff;
844 static inline uint16_t applyPPChighesta (uint64_t value) {
845 return ((value + 0x8000) >> 48) & 0xffff;
848 void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section,
849 uint64_t Offset, uint64_t Value,
850 uint32_t Type, int64_t Addend) {
851 uint8_t *LocalAddress = Section.Address + Offset;
854 llvm_unreachable("Relocation type not implemented yet!");
856 case ELF::R_PPC64_ADDR16:
857 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
859 case ELF::R_PPC64_ADDR16_DS:
860 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
862 case ELF::R_PPC64_ADDR16_LO:
863 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
865 case ELF::R_PPC64_ADDR16_LO_DS:
866 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
868 case ELF::R_PPC64_ADDR16_HI:
869 writeInt16BE(LocalAddress, applyPPChi(Value + Addend));
871 case ELF::R_PPC64_ADDR16_HA:
872 writeInt16BE(LocalAddress, applyPPCha(Value + Addend));
874 case ELF::R_PPC64_ADDR16_HIGHER:
875 writeInt16BE(LocalAddress, applyPPChigher(Value + Addend));
877 case ELF::R_PPC64_ADDR16_HIGHERA:
878 writeInt16BE(LocalAddress, applyPPChighera(Value + Addend));
880 case ELF::R_PPC64_ADDR16_HIGHEST:
881 writeInt16BE(LocalAddress, applyPPChighest(Value + Addend));
883 case ELF::R_PPC64_ADDR16_HIGHESTA:
884 writeInt16BE(LocalAddress, applyPPChighesta(Value + Addend));
886 case ELF::R_PPC64_ADDR14: {
887 assert(((Value + Addend) & 3) == 0);
888 // Preserve the AA/LK bits in the branch instruction
889 uint8_t aalk = *(LocalAddress + 3);
890 writeInt16BE(LocalAddress + 2, (aalk & 3) | ((Value + Addend) & 0xfffc));
892 case ELF::R_PPC64_REL16_LO: {
893 uint64_t FinalAddress = (Section.LoadAddress + Offset);
894 uint64_t Delta = Value - FinalAddress + Addend;
895 writeInt16BE(LocalAddress, applyPPClo(Delta));
897 case ELF::R_PPC64_REL16_HI: {
898 uint64_t FinalAddress = (Section.LoadAddress + Offset);
899 uint64_t Delta = Value - FinalAddress + Addend;
900 writeInt16BE(LocalAddress, applyPPChi(Delta));
902 case ELF::R_PPC64_REL16_HA: {
903 uint64_t FinalAddress = (Section.LoadAddress + Offset);
904 uint64_t Delta = Value - FinalAddress + Addend;
905 writeInt16BE(LocalAddress, applyPPCha(Delta));
907 case ELF::R_PPC64_ADDR32: {
908 int32_t Result = static_cast<int32_t>(Value + Addend);
909 if (SignExtend32<32>(Result) != Result)
910 llvm_unreachable("Relocation R_PPC64_ADDR32 overflow");
911 writeInt32BE(LocalAddress, Result);
913 case ELF::R_PPC64_REL24: {
914 uint64_t FinalAddress = (Section.LoadAddress + Offset);
915 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
916 if (SignExtend32<24>(delta) != delta)
917 llvm_unreachable("Relocation R_PPC64_REL24 overflow");
918 // Generates a 'bl <address>' instruction
919 writeInt32BE(LocalAddress, 0x48000001 | (delta & 0x03FFFFFC));
921 case ELF::R_PPC64_REL32: {
922 uint64_t FinalAddress = (Section.LoadAddress + Offset);
923 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
924 if (SignExtend32<32>(delta) != delta)
925 llvm_unreachable("Relocation R_PPC64_REL32 overflow");
926 writeInt32BE(LocalAddress, delta);
928 case ELF::R_PPC64_REL64: {
929 uint64_t FinalAddress = (Section.LoadAddress + Offset);
930 uint64_t Delta = Value - FinalAddress + Addend;
931 writeInt64BE(LocalAddress, Delta);
933 case ELF::R_PPC64_ADDR64:
934 writeInt64BE(LocalAddress, Value + Addend);
939 void RuntimeDyldELF::resolveSystemZRelocation(const SectionEntry &Section,
940 uint64_t Offset, uint64_t Value,
941 uint32_t Type, int64_t Addend) {
942 uint8_t *LocalAddress = Section.Address + Offset;
945 llvm_unreachable("Relocation type not implemented yet!");
947 case ELF::R_390_PC16DBL:
948 case ELF::R_390_PLT16DBL: {
949 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
950 assert(int16_t(Delta / 2) * 2 == Delta && "R_390_PC16DBL overflow");
951 writeInt16BE(LocalAddress, Delta / 2);
954 case ELF::R_390_PC32DBL:
955 case ELF::R_390_PLT32DBL: {
956 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
957 assert(int32_t(Delta / 2) * 2 == Delta && "R_390_PC32DBL overflow");
958 writeInt32BE(LocalAddress, Delta / 2);
961 case ELF::R_390_PC32: {
962 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
963 assert(int32_t(Delta) == Delta && "R_390_PC32 overflow");
964 writeInt32BE(LocalAddress, Delta);
968 writeInt64BE(LocalAddress, Value + Addend);
973 // The target location for the relocation is described by RE.SectionID and
974 // RE.Offset. RE.SectionID can be used to find the SectionEntry. Each
975 // SectionEntry has three members describing its location.
976 // SectionEntry::Address is the address at which the section has been loaded
977 // into memory in the current (host) process. SectionEntry::LoadAddress is the
978 // address that the section will have in the target process.
979 // SectionEntry::ObjAddress is the address of the bits for this section in the
980 // original emitted object image (also in the current address space).
982 // Relocations will be applied as if the section were loaded at
983 // SectionEntry::LoadAddress, but they will be applied at an address based
984 // on SectionEntry::Address. SectionEntry::ObjAddress will be used to refer to
985 // Target memory contents if they are required for value calculations.
987 // The Value parameter here is the load address of the symbol for the
988 // relocation to be applied. For relocations which refer to symbols in the
989 // current object Value will be the LoadAddress of the section in which
990 // the symbol resides (RE.Addend provides additional information about the
991 // symbol location). For external symbols, Value will be the address of the
992 // symbol in the target address space.
993 void RuntimeDyldELF::resolveRelocation(const RelocationEntry &RE,
995 const SectionEntry &Section = Sections[RE.SectionID];
996 return resolveRelocation(Section, RE.Offset, Value, RE.RelType, RE.Addend,
997 RE.SymOffset, RE.SectionID);
1000 void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section,
1001 uint64_t Offset, uint64_t Value,
1002 uint32_t Type, int64_t Addend,
1003 uint64_t SymOffset, SID SectionID) {
1005 case Triple::x86_64:
1006 resolveX86_64Relocation(Section, Offset, Value, Type, Addend, SymOffset);
1009 resolveX86Relocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
1010 (uint32_t)(Addend & 0xffffffffL));
1012 case Triple::aarch64:
1013 case Triple::aarch64_be:
1014 resolveAArch64Relocation(Section, Offset, Value, Type, Addend);
1016 case Triple::arm: // Fall through.
1019 case Triple::thumbeb:
1020 resolveARMRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
1021 (uint32_t)(Addend & 0xffffffffL));
1023 case Triple::mips: // Fall through.
1024 case Triple::mipsel:
1025 case Triple::mips64:
1026 case Triple::mips64el:
1028 resolveMIPSRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL),
1029 Type, (uint32_t)(Addend & 0xffffffffL));
1030 else if (IsMipsN64ABI)
1031 resolveMIPS64Relocation(Section, Offset, Value, Type, Addend, SymOffset,
1034 llvm_unreachable("Mips ABI not handled");
1036 case Triple::ppc64: // Fall through.
1037 case Triple::ppc64le:
1038 resolvePPC64Relocation(Section, Offset, Value, Type, Addend);
1040 case Triple::systemz:
1041 resolveSystemZRelocation(Section, Offset, Value, Type, Addend);
1044 llvm_unreachable("Unsupported CPU type!");
1048 void *RuntimeDyldELF::computePlaceholderAddress(unsigned SectionID, uint64_t Offset) const {
1049 return (void*)(Sections[SectionID].ObjAddress + Offset);
1052 void RuntimeDyldELF::processSimpleRelocation(unsigned SectionID, uint64_t Offset, unsigned RelType, RelocationValueRef Value) {
1053 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend, Value.Offset);
1054 if (Value.SymbolName)
1055 addRelocationForSymbol(RE, Value.SymbolName);
1057 addRelocationForSection(RE, Value.SectionID);
1060 relocation_iterator RuntimeDyldELF::processRelocationRef(
1061 unsigned SectionID, relocation_iterator RelI, const ObjectFile &O,
1062 ObjSectionToIDMap &ObjSectionToID, StubMap &Stubs) {
1063 const auto &Obj = cast<ELFObjectFileBase>(O);
1065 Check(RelI->getType(RelType));
1067 if (Obj.hasRelocationAddend(RelI->getRawDataRefImpl()))
1068 Addend = *Obj.getRelocationAddend(RelI->getRawDataRefImpl());
1069 symbol_iterator Symbol = RelI->getSymbol();
1071 // Obtain the symbol name which is referenced in the relocation
1072 StringRef TargetName;
1073 if (Symbol != Obj.symbol_end())
1074 Symbol->getName(TargetName);
1075 DEBUG(dbgs() << "\t\tRelType: " << RelType << " Addend: " << Addend
1076 << " TargetName: " << TargetName << "\n");
1077 RelocationValueRef Value;
1078 // First search for the symbol in the local symbol table
1079 SymbolRef::Type SymType = SymbolRef::ST_Unknown;
1081 // Search for the symbol in the global symbol table
1082 RTDyldSymbolTable::const_iterator gsi = GlobalSymbolTable.end();
1083 if (Symbol != Obj.symbol_end()) {
1084 gsi = GlobalSymbolTable.find(TargetName.data());
1085 Symbol->getType(SymType);
1087 if (gsi != GlobalSymbolTable.end()) {
1088 const auto &SymInfo = gsi->second;
1089 Value.SectionID = SymInfo.getSectionID();
1090 Value.Offset = SymInfo.getOffset();
1091 Value.Addend = SymInfo.getOffset() + Addend;
1094 case SymbolRef::ST_Debug: {
1095 // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously
1096 // and can be changed by another developers. Maybe best way is add
1097 // a new symbol type ST_Section to SymbolRef and use it.
1098 section_iterator si(Obj.section_end());
1099 Symbol->getSection(si);
1100 if (si == Obj.section_end())
1101 llvm_unreachable("Symbol section not found, bad object file format!");
1102 DEBUG(dbgs() << "\t\tThis is section symbol\n");
1103 bool isCode = si->isText();
1104 Value.SectionID = findOrEmitSection(Obj, (*si), isCode, ObjSectionToID);
1105 Value.Addend = Addend;
1108 case SymbolRef::ST_Data:
1109 case SymbolRef::ST_Unknown: {
1110 Value.SymbolName = TargetName.data();
1111 Value.Addend = Addend;
1113 // Absolute relocations will have a zero symbol ID (STN_UNDEF), which
1114 // will manifest here as a NULL symbol name.
1115 // We can set this as a valid (but empty) symbol name, and rely
1116 // on addRelocationForSymbol to handle this.
1117 if (!Value.SymbolName)
1118 Value.SymbolName = "";
1122 llvm_unreachable("Unresolved symbol type!");
1128 Check(RelI->getOffset(Offset));
1130 DEBUG(dbgs() << "\t\tSectionID: " << SectionID << " Offset: " << Offset
1132 if ((Arch == Triple::aarch64 || Arch == Triple::aarch64_be) &&
1133 (RelType == ELF::R_AARCH64_CALL26 || RelType == ELF::R_AARCH64_JUMP26)) {
1134 // This is an AArch64 branch relocation, need to use a stub function.
1135 DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation.");
1136 SectionEntry &Section = Sections[SectionID];
1138 // Look for an existing stub.
1139 StubMap::const_iterator i = Stubs.find(Value);
1140 if (i != Stubs.end()) {
1141 resolveRelocation(Section, Offset, (uint64_t)Section.Address + i->second,
1143 DEBUG(dbgs() << " Stub function found\n");
1145 // Create a new stub function.
1146 DEBUG(dbgs() << " Create a new stub function\n");
1147 Stubs[Value] = Section.StubOffset;
1148 uint8_t *StubTargetAddr =
1149 createStubFunction(Section.Address + Section.StubOffset);
1151 RelocationEntry REmovz_g3(SectionID, StubTargetAddr - Section.Address,
1152 ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend);
1153 RelocationEntry REmovk_g2(SectionID, StubTargetAddr - Section.Address + 4,
1154 ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend);
1155 RelocationEntry REmovk_g1(SectionID, StubTargetAddr - Section.Address + 8,
1156 ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend);
1157 RelocationEntry REmovk_g0(SectionID,
1158 StubTargetAddr - Section.Address + 12,
1159 ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend);
1161 if (Value.SymbolName) {
1162 addRelocationForSymbol(REmovz_g3, Value.SymbolName);
1163 addRelocationForSymbol(REmovk_g2, Value.SymbolName);
1164 addRelocationForSymbol(REmovk_g1, Value.SymbolName);
1165 addRelocationForSymbol(REmovk_g0, Value.SymbolName);
1167 addRelocationForSection(REmovz_g3, Value.SectionID);
1168 addRelocationForSection(REmovk_g2, Value.SectionID);
1169 addRelocationForSection(REmovk_g1, Value.SectionID);
1170 addRelocationForSection(REmovk_g0, Value.SectionID);
1172 resolveRelocation(Section, Offset,
1173 (uint64_t)Section.Address + Section.StubOffset, RelType,
1175 Section.StubOffset += getMaxStubSize();
1177 } else if (Arch == Triple::arm) {
1178 if (RelType == ELF::R_ARM_PC24 || RelType == ELF::R_ARM_CALL ||
1179 RelType == ELF::R_ARM_JUMP24) {
1180 // This is an ARM branch relocation, need to use a stub function.
1181 DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.");
1182 SectionEntry &Section = Sections[SectionID];
1184 // Look for an existing stub.
1185 StubMap::const_iterator i = Stubs.find(Value);
1186 if (i != Stubs.end()) {
1187 resolveRelocation(Section, Offset, (uint64_t)Section.Address + i->second,
1189 DEBUG(dbgs() << " Stub function found\n");
1191 // Create a new stub function.
1192 DEBUG(dbgs() << " Create a new stub function\n");
1193 Stubs[Value] = Section.StubOffset;
1194 uint8_t *StubTargetAddr =
1195 createStubFunction(Section.Address + Section.StubOffset);
1196 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1197 ELF::R_ARM_ABS32, Value.Addend);
1198 if (Value.SymbolName)
1199 addRelocationForSymbol(RE, Value.SymbolName);
1201 addRelocationForSection(RE, Value.SectionID);
1203 resolveRelocation(Section, Offset,
1204 (uint64_t)Section.Address + Section.StubOffset, RelType,
1206 Section.StubOffset += getMaxStubSize();
1209 uint32_t *Placeholder =
1210 reinterpret_cast<uint32_t*>(computePlaceholderAddress(SectionID, Offset));
1211 if (RelType == ELF::R_ARM_PREL31 || RelType == ELF::R_ARM_TARGET1 ||
1212 RelType == ELF::R_ARM_ABS32) {
1213 Value.Addend += *Placeholder;
1214 } else if (RelType == ELF::R_ARM_MOVW_ABS_NC || RelType == ELF::R_ARM_MOVT_ABS) {
1215 // See ELF for ARM documentation
1216 Value.Addend += (int16_t)((*Placeholder & 0xFFF) | (((*Placeholder >> 16) & 0xF) << 12));
1218 processSimpleRelocation(SectionID, Offset, RelType, Value);
1220 } else if (IsMipsO32ABI) {
1221 uint8_t *Placeholder = reinterpret_cast<uint8_t *>(
1222 computePlaceholderAddress(SectionID, Offset));
1223 uint32_t Opcode = readBytesUnaligned(Placeholder, 4);
1224 if (RelType == ELF::R_MIPS_26) {
1225 // This is an Mips branch relocation, need to use a stub function.
1226 DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
1227 SectionEntry &Section = Sections[SectionID];
1229 // Extract the addend from the instruction.
1230 // We shift up by two since the Value will be down shifted again
1231 // when applying the relocation.
1232 uint32_t Addend = (Opcode & 0x03ffffff) << 2;
1234 Value.Addend += Addend;
1236 // Look up for existing stub.
1237 StubMap::const_iterator i = Stubs.find(Value);
1238 if (i != Stubs.end()) {
1239 RelocationEntry RE(SectionID, Offset, RelType, i->second);
1240 addRelocationForSection(RE, SectionID);
1241 DEBUG(dbgs() << " Stub function found\n");
1243 // Create a new stub function.
1244 DEBUG(dbgs() << " Create a new stub function\n");
1245 Stubs[Value] = Section.StubOffset;
1246 uint8_t *StubTargetAddr =
1247 createStubFunction(Section.Address + Section.StubOffset);
1249 // Creating Hi and Lo relocations for the filled stub instructions.
1250 RelocationEntry REHi(SectionID, StubTargetAddr - Section.Address,
1251 ELF::R_MIPS_HI16, Value.Addend);
1252 RelocationEntry RELo(SectionID, StubTargetAddr - Section.Address + 4,
1253 ELF::R_MIPS_LO16, Value.Addend);
1255 if (Value.SymbolName) {
1256 addRelocationForSymbol(REHi, Value.SymbolName);
1257 addRelocationForSymbol(RELo, Value.SymbolName);
1260 addRelocationForSection(REHi, Value.SectionID);
1261 addRelocationForSection(RELo, Value.SectionID);
1264 RelocationEntry RE(SectionID, Offset, RelType, Section.StubOffset);
1265 addRelocationForSection(RE, SectionID);
1266 Section.StubOffset += getMaxStubSize();
1269 if (RelType == ELF::R_MIPS_HI16)
1270 Value.Addend += (Opcode & 0x0000ffff) << 16;
1271 else if (RelType == ELF::R_MIPS_LO16)
1272 Value.Addend += (Opcode & 0x0000ffff);
1273 else if (RelType == ELF::R_MIPS_32)
1274 Value.Addend += Opcode;
1275 processSimpleRelocation(SectionID, Offset, RelType, Value);
1277 } else if (IsMipsN64ABI) {
1278 uint32_t r_type = RelType & 0xff;
1279 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1280 if (r_type == ELF::R_MIPS_CALL16 || r_type == ELF::R_MIPS_GOT_PAGE
1281 || r_type == ELF::R_MIPS_GOT_DISP) {
1282 StringMap<uint64_t>::iterator i = GOTSymbolOffsets.find(TargetName);
1283 if (i != GOTSymbolOffsets.end())
1284 RE.SymOffset = i->second;
1286 RE.SymOffset = allocateGOTEntries(SectionID, 1);
1287 GOTSymbolOffsets[TargetName] = RE.SymOffset;
1290 if (Value.SymbolName)
1291 addRelocationForSymbol(RE, Value.SymbolName);
1293 addRelocationForSection(RE, Value.SectionID);
1294 } else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) {
1295 if (RelType == ELF::R_PPC64_REL24) {
1296 // Determine ABI variant in use for this object.
1297 unsigned AbiVariant;
1298 Obj.getPlatformFlags(AbiVariant);
1299 AbiVariant &= ELF::EF_PPC64_ABI;
1300 // A PPC branch relocation will need a stub function if the target is
1301 // an external symbol (Symbol::ST_Unknown) or if the target address
1302 // is not within the signed 24-bits branch address.
1303 SectionEntry &Section = Sections[SectionID];
1304 uint8_t *Target = Section.Address + Offset;
1305 bool RangeOverflow = false;
1306 if (SymType != SymbolRef::ST_Unknown) {
1307 if (AbiVariant != 2) {
1308 // In the ELFv1 ABI, a function call may point to the .opd entry,
1309 // so the final symbol value is calculated based on the relocation
1310 // values in the .opd section.
1311 findOPDEntrySection(Obj, ObjSectionToID, Value);
1313 // In the ELFv2 ABI, a function symbol may provide a local entry
1314 // point, which must be used for direct calls.
1316 Symbol->getOther(SymOther);
1317 Value.Addend += ELF::decodePPC64LocalEntryOffset(SymOther);
1319 uint8_t *RelocTarget = Sections[Value.SectionID].Address + Value.Addend;
1320 int32_t delta = static_cast<int32_t>(Target - RelocTarget);
1321 // If it is within 24-bits branch range, just set the branch target
1322 if (SignExtend32<24>(delta) == delta) {
1323 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1324 if (Value.SymbolName)
1325 addRelocationForSymbol(RE, Value.SymbolName);
1327 addRelocationForSection(RE, Value.SectionID);
1329 RangeOverflow = true;
1332 if (SymType == SymbolRef::ST_Unknown || RangeOverflow) {
1333 // It is an external symbol (SymbolRef::ST_Unknown) or within a range
1334 // larger than 24-bits.
1335 StubMap::const_iterator i = Stubs.find(Value);
1336 if (i != Stubs.end()) {
1337 // Symbol function stub already created, just relocate to it
1338 resolveRelocation(Section, Offset,
1339 (uint64_t)Section.Address + i->second, RelType, 0);
1340 DEBUG(dbgs() << " Stub function found\n");
1342 // Create a new stub function.
1343 DEBUG(dbgs() << " Create a new stub function\n");
1344 Stubs[Value] = Section.StubOffset;
1345 uint8_t *StubTargetAddr =
1346 createStubFunction(Section.Address + Section.StubOffset,
1348 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1349 ELF::R_PPC64_ADDR64, Value.Addend);
1351 // Generates the 64-bits address loads as exemplified in section
1352 // 4.5.1 in PPC64 ELF ABI. Note that the relocations need to
1353 // apply to the low part of the instructions, so we have to update
1354 // the offset according to the target endianness.
1355 uint64_t StubRelocOffset = StubTargetAddr - Section.Address;
1356 if (!IsTargetLittleEndian)
1357 StubRelocOffset += 2;
1359 RelocationEntry REhst(SectionID, StubRelocOffset + 0,
1360 ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend);
1361 RelocationEntry REhr(SectionID, StubRelocOffset + 4,
1362 ELF::R_PPC64_ADDR16_HIGHER, Value.Addend);
1363 RelocationEntry REh(SectionID, StubRelocOffset + 12,
1364 ELF::R_PPC64_ADDR16_HI, Value.Addend);
1365 RelocationEntry REl(SectionID, StubRelocOffset + 16,
1366 ELF::R_PPC64_ADDR16_LO, Value.Addend);
1368 if (Value.SymbolName) {
1369 addRelocationForSymbol(REhst, Value.SymbolName);
1370 addRelocationForSymbol(REhr, Value.SymbolName);
1371 addRelocationForSymbol(REh, Value.SymbolName);
1372 addRelocationForSymbol(REl, Value.SymbolName);
1374 addRelocationForSection(REhst, Value.SectionID);
1375 addRelocationForSection(REhr, Value.SectionID);
1376 addRelocationForSection(REh, Value.SectionID);
1377 addRelocationForSection(REl, Value.SectionID);
1380 resolveRelocation(Section, Offset,
1381 (uint64_t)Section.Address + Section.StubOffset,
1383 Section.StubOffset += getMaxStubSize();
1385 if (SymType == SymbolRef::ST_Unknown) {
1386 // Restore the TOC for external calls
1387 if (AbiVariant == 2)
1388 writeInt32BE(Target + 4, 0xE8410018); // ld r2,28(r1)
1390 writeInt32BE(Target + 4, 0xE8410028); // ld r2,40(r1)
1393 } else if (RelType == ELF::R_PPC64_TOC16 ||
1394 RelType == ELF::R_PPC64_TOC16_DS ||
1395 RelType == ELF::R_PPC64_TOC16_LO ||
1396 RelType == ELF::R_PPC64_TOC16_LO_DS ||
1397 RelType == ELF::R_PPC64_TOC16_HI ||
1398 RelType == ELF::R_PPC64_TOC16_HA) {
1399 // These relocations are supposed to subtract the TOC address from
1400 // the final value. This does not fit cleanly into the RuntimeDyld
1401 // scheme, since there may be *two* sections involved in determining
1402 // the relocation value (the section of the symbol refered to by the
1403 // relocation, and the TOC section associated with the current module).
1405 // Fortunately, these relocations are currently only ever generated
1406 // refering to symbols that themselves reside in the TOC, which means
1407 // that the two sections are actually the same. Thus they cancel out
1408 // and we can immediately resolve the relocation right now.
1410 case ELF::R_PPC64_TOC16: RelType = ELF::R_PPC64_ADDR16; break;
1411 case ELF::R_PPC64_TOC16_DS: RelType = ELF::R_PPC64_ADDR16_DS; break;
1412 case ELF::R_PPC64_TOC16_LO: RelType = ELF::R_PPC64_ADDR16_LO; break;
1413 case ELF::R_PPC64_TOC16_LO_DS: RelType = ELF::R_PPC64_ADDR16_LO_DS; break;
1414 case ELF::R_PPC64_TOC16_HI: RelType = ELF::R_PPC64_ADDR16_HI; break;
1415 case ELF::R_PPC64_TOC16_HA: RelType = ELF::R_PPC64_ADDR16_HA; break;
1416 default: llvm_unreachable("Wrong relocation type.");
1419 RelocationValueRef TOCValue;
1420 findPPC64TOCSection(Obj, ObjSectionToID, TOCValue);
1421 if (Value.SymbolName || Value.SectionID != TOCValue.SectionID)
1422 llvm_unreachable("Unsupported TOC relocation.");
1423 Value.Addend -= TOCValue.Addend;
1424 resolveRelocation(Sections[SectionID], Offset, Value.Addend, RelType, 0);
1426 // There are two ways to refer to the TOC address directly: either
1427 // via a ELF::R_PPC64_TOC relocation (where both symbol and addend are
1428 // ignored), or via any relocation that refers to the magic ".TOC."
1429 // symbols (in which case the addend is respected).
1430 if (RelType == ELF::R_PPC64_TOC) {
1431 RelType = ELF::R_PPC64_ADDR64;
1432 findPPC64TOCSection(Obj, ObjSectionToID, Value);
1433 } else if (TargetName == ".TOC.") {
1434 findPPC64TOCSection(Obj, ObjSectionToID, Value);
1435 Value.Addend += Addend;
1438 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1440 if (Value.SymbolName)
1441 addRelocationForSymbol(RE, Value.SymbolName);
1443 addRelocationForSection(RE, Value.SectionID);
1445 } else if (Arch == Triple::systemz &&
1446 (RelType == ELF::R_390_PLT32DBL || RelType == ELF::R_390_GOTENT)) {
1447 // Create function stubs for both PLT and GOT references, regardless of
1448 // whether the GOT reference is to data or code. The stub contains the
1449 // full address of the symbol, as needed by GOT references, and the
1450 // executable part only adds an overhead of 8 bytes.
1452 // We could try to conserve space by allocating the code and data
1453 // parts of the stub separately. However, as things stand, we allocate
1454 // a stub for every relocation, so using a GOT in JIT code should be
1455 // no less space efficient than using an explicit constant pool.
1456 DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation.");
1457 SectionEntry &Section = Sections[SectionID];
1459 // Look for an existing stub.
1460 StubMap::const_iterator i = Stubs.find(Value);
1461 uintptr_t StubAddress;
1462 if (i != Stubs.end()) {
1463 StubAddress = uintptr_t(Section.Address) + i->second;
1464 DEBUG(dbgs() << " Stub function found\n");
1466 // Create a new stub function.
1467 DEBUG(dbgs() << " Create a new stub function\n");
1469 uintptr_t BaseAddress = uintptr_t(Section.Address);
1470 uintptr_t StubAlignment = getStubAlignment();
1471 StubAddress = (BaseAddress + Section.StubOffset + StubAlignment - 1) &
1473 unsigned StubOffset = StubAddress - BaseAddress;
1475 Stubs[Value] = StubOffset;
1476 createStubFunction((uint8_t *)StubAddress);
1477 RelocationEntry RE(SectionID, StubOffset + 8, ELF::R_390_64,
1479 if (Value.SymbolName)
1480 addRelocationForSymbol(RE, Value.SymbolName);
1482 addRelocationForSection(RE, Value.SectionID);
1483 Section.StubOffset = StubOffset + getMaxStubSize();
1486 if (RelType == ELF::R_390_GOTENT)
1487 resolveRelocation(Section, Offset, StubAddress + 8, ELF::R_390_PC32DBL,
1490 resolveRelocation(Section, Offset, StubAddress, RelType, Addend);
1491 } else if (Arch == Triple::x86_64) {
1492 if (RelType == ELF::R_X86_64_PLT32) {
1493 // The way the PLT relocations normally work is that the linker allocates
1495 // PLT and this relocation makes a PC-relative call into the PLT. The PLT
1496 // entry will then jump to an address provided by the GOT. On first call,
1498 // GOT address will point back into PLT code that resolves the symbol. After
1499 // the first call, the GOT entry points to the actual function.
1501 // For local functions we're ignoring all of that here and just replacing
1502 // the PLT32 relocation type with PC32, which will translate the relocation
1503 // into a PC-relative call directly to the function. For external symbols we
1504 // can't be sure the function will be within 2^32 bytes of the call site, so
1505 // we need to create a stub, which calls into the GOT. This case is
1506 // equivalent to the usual PLT implementation except that we use the stub
1507 // mechanism in RuntimeDyld (which puts stubs at the end of the section)
1508 // rather than allocating a PLT section.
1509 if (Value.SymbolName) {
1510 // This is a call to an external function.
1511 // Look for an existing stub.
1512 SectionEntry &Section = Sections[SectionID];
1513 StubMap::const_iterator i = Stubs.find(Value);
1514 uintptr_t StubAddress;
1515 if (i != Stubs.end()) {
1516 StubAddress = uintptr_t(Section.Address) + i->second;
1517 DEBUG(dbgs() << " Stub function found\n");
1519 // Create a new stub function (equivalent to a PLT entry).
1520 DEBUG(dbgs() << " Create a new stub function\n");
1522 uintptr_t BaseAddress = uintptr_t(Section.Address);
1523 uintptr_t StubAlignment = getStubAlignment();
1524 StubAddress = (BaseAddress + Section.StubOffset + StubAlignment - 1) &
1526 unsigned StubOffset = StubAddress - BaseAddress;
1527 Stubs[Value] = StubOffset;
1528 createStubFunction((uint8_t *)StubAddress);
1530 // Bump our stub offset counter
1531 Section.StubOffset = StubOffset + getMaxStubSize();
1533 // Allocate a GOT Entry
1534 uint64_t GOTOffset = allocateGOTEntries(SectionID, 1);
1536 // The load of the GOT address has an addend of -4
1537 resolveGOTOffsetRelocation(SectionID, StubOffset + 2, GOTOffset - 4);
1539 // Fill in the value of the symbol we're targeting into the GOT
1540 addRelocationForSymbol(computeGOTOffsetRE(SectionID,GOTOffset,0,ELF::R_X86_64_64),
1544 // Make the target call a call into the stub table.
1545 resolveRelocation(Section, Offset, StubAddress, ELF::R_X86_64_PC32,
1548 RelocationEntry RE(SectionID, Offset, ELF::R_X86_64_PC32, Value.Addend,
1550 addRelocationForSection(RE, Value.SectionID);
1552 } else if (RelType == ELF::R_X86_64_GOTPCREL) {
1553 uint64_t GOTOffset = allocateGOTEntries(SectionID, 1);
1554 resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend);
1556 // Fill in the value of the symbol we're targeting into the GOT
1557 RelocationEntry RE = computeGOTOffsetRE(SectionID, GOTOffset, Value.Offset, ELF::R_X86_64_64);
1558 if (Value.SymbolName)
1559 addRelocationForSymbol(RE, Value.SymbolName);
1561 addRelocationForSection(RE, Value.SectionID);
1562 } else if (RelType == ELF::R_X86_64_PC32) {
1563 Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset));
1564 processSimpleRelocation(SectionID, Offset, RelType, Value);
1565 } else if (RelType == ELF::R_X86_64_PC64) {
1566 Value.Addend += support::ulittle64_t::ref(computePlaceholderAddress(SectionID, Offset));
1567 processSimpleRelocation(SectionID, Offset, RelType, Value);
1569 processSimpleRelocation(SectionID, Offset, RelType, Value);
1572 if (Arch == Triple::x86) {
1573 Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset));
1575 processSimpleRelocation(SectionID, Offset, RelType, Value);
1580 size_t RuntimeDyldELF::getGOTEntrySize() {
1581 // We don't use the GOT in all of these cases, but it's essentially free
1582 // to put them all here.
1585 case Triple::x86_64:
1586 case Triple::aarch64:
1587 case Triple::aarch64_be:
1589 case Triple::ppc64le:
1590 case Triple::systemz:
1591 Result = sizeof(uint64_t);
1596 Result = sizeof(uint32_t);
1599 case Triple::mipsel:
1600 case Triple::mips64:
1601 case Triple::mips64el:
1603 Result = sizeof(uint32_t);
1604 else if (IsMipsN64ABI)
1605 Result = sizeof(uint64_t);
1607 llvm_unreachable("Mips ABI not handled");
1610 llvm_unreachable("Unsupported CPU type!");
1615 uint64_t RuntimeDyldELF::allocateGOTEntries(unsigned SectionID, unsigned no)
1617 (void)SectionID; // The GOT Section is the same for all section in the object file
1618 if (GOTSectionID == 0) {
1619 GOTSectionID = Sections.size();
1620 // Reserve a section id. We'll allocate the section later
1621 // once we know the total size
1622 Sections.push_back(SectionEntry(".got", 0, 0, 0));
1624 uint64_t StartOffset = CurrentGOTIndex * getGOTEntrySize();
1625 CurrentGOTIndex += no;
1629 void RuntimeDyldELF::resolveGOTOffsetRelocation(unsigned SectionID, uint64_t Offset, uint64_t GOTOffset)
1631 // Fill in the relative address of the GOT Entry into the stub
1632 RelocationEntry GOTRE(SectionID, Offset, ELF::R_X86_64_PC32, GOTOffset);
1633 addRelocationForSection(GOTRE, GOTSectionID);
1636 RelocationEntry RuntimeDyldELF::computeGOTOffsetRE(unsigned SectionID, uint64_t GOTOffset, uint64_t SymbolOffset,
1639 (void)SectionID; // The GOT Section is the same for all section in the object file
1640 return RelocationEntry(GOTSectionID, GOTOffset, Type, SymbolOffset);
1643 void RuntimeDyldELF::finalizeLoad(const ObjectFile &Obj,
1644 ObjSectionToIDMap &SectionMap) {
1645 // If necessary, allocate the global offset table
1646 if (GOTSectionID != 0) {
1647 // Allocate memory for the section
1648 size_t TotalSize = CurrentGOTIndex * getGOTEntrySize();
1649 uint8_t *Addr = MemMgr.allocateDataSection(TotalSize, getGOTEntrySize(),
1650 GOTSectionID, ".got", false);
1652 report_fatal_error("Unable to allocate memory for GOT!");
1654 Sections[GOTSectionID] = SectionEntry(".got", Addr, TotalSize, 0);
1657 Checker->registerSection(Obj.getFileName(), GOTSectionID);
1659 // For now, initialize all GOT entries to zero. We'll fill them in as
1660 // needed when GOT-based relocations are applied.
1661 memset(Addr, 0, TotalSize);
1663 // To correctly resolve Mips GOT relocations, we need a mapping from
1664 // object's sections to GOTs.
1665 for (section_iterator SI = Obj.section_begin(), SE = Obj.section_end();
1667 if (SI->relocation_begin() != SI->relocation_end()) {
1668 section_iterator RelocatedSection = SI->getRelocatedSection();
1669 ObjSectionToIDMap::iterator i = SectionMap.find(*RelocatedSection);
1670 assert (i != SectionMap.end());
1671 SectionToGOTMap[i->second] = GOTSectionID;
1674 GOTSymbolOffsets.clear();
1678 // Look for and record the EH frame section.
1679 ObjSectionToIDMap::iterator i, e;
1680 for (i = SectionMap.begin(), e = SectionMap.end(); i != e; ++i) {
1681 const SectionRef &Section = i->first;
1683 Section.getName(Name);
1684 if (Name == ".eh_frame") {
1685 UnregisteredEHFrameSections.push_back(i->second);
1691 CurrentGOTIndex = 0;
1694 bool RuntimeDyldELF::isCompatibleFile(const object::ObjectFile &Obj) const {