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, 2, false> ELF32LE;
161 DebugObj = createRTDyldELFObject<ELF32LE>(Buffer->getMemBufferRef(), L, ec);
162 } else if (Obj.getBytesInAddress() == 4 && !Obj.isLittleEndian()) {
163 typedef ELFType<support::big, 2, false> ELF32BE;
164 DebugObj = createRTDyldELFObject<ELF32BE>(Buffer->getMemBufferRef(), L, ec);
165 } else if (Obj.getBytesInAddress() == 8 && !Obj.isLittleEndian()) {
166 typedef ELFType<support::big, 2, true> ELF64BE;
167 DebugObj = createRTDyldELFObject<ELF64BE>(Buffer->getMemBufferRef(), L, ec);
168 } else if (Obj.getBytesInAddress() == 8 && Obj.isLittleEndian()) {
169 typedef ELFType<support::little, 2, 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() << "resolveMipselocation, 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);
510 void RuntimeDyldELF::setMipsABI(const ObjectFile &Obj) {
511 if (!StringRef(Triple::getArchTypePrefix(Arch)).equals("mips")) {
512 IsMipsO32ABI = false;
513 IsMipsN64ABI = false;
517 Obj.getPlatformFlags(AbiVariant);
518 IsMipsO32ABI = AbiVariant & ELF::EF_MIPS_ABI_O32;
519 IsMipsN64ABI = Obj.getFileFormatName().equals("ELF64-mips");
520 if (AbiVariant & ELF::EF_MIPS_ABI2)
521 llvm_unreachable("Mips N32 ABI is not supported yet");
524 void RuntimeDyldELF::resolveMIPS64Relocation(const SectionEntry &Section,
525 uint64_t Offset, uint64_t Value,
526 uint32_t Type, int64_t Addend,
529 uint32_t r_type = Type & 0xff;
530 uint32_t r_type2 = (Type >> 8) & 0xff;
531 uint32_t r_type3 = (Type >> 16) & 0xff;
533 // RelType is used to keep information for which relocation type we are
534 // applying relocation.
535 uint32_t RelType = r_type;
536 int64_t CalculatedValue = evaluateMIPS64Relocation(Section, Offset, Value,
538 SymOffset, SectionID);
539 if (r_type2 != ELF::R_MIPS_NONE) {
541 CalculatedValue = evaluateMIPS64Relocation(Section, Offset, 0, RelType,
542 CalculatedValue, SymOffset,
545 if (r_type3 != ELF::R_MIPS_NONE) {
547 CalculatedValue = evaluateMIPS64Relocation(Section, Offset, 0, RelType,
548 CalculatedValue, SymOffset,
551 applyMIPS64Relocation(Section.Address + Offset, CalculatedValue, RelType);
555 RuntimeDyldELF::evaluateMIPS64Relocation(const SectionEntry &Section,
556 uint64_t Offset, uint64_t Value,
557 uint32_t Type, int64_t Addend,
558 uint64_t SymOffset, SID SectionID) {
560 DEBUG(dbgs() << "evaluateMIPS64Relocation, LocalAddress: 0x"
561 << format("%llx", Section.Address + Offset)
562 << " FinalAddress: 0x"
563 << format("%llx", Section.LoadAddress + Offset)
564 << " Value: 0x" << format("%llx", Value) << " Type: 0x"
565 << format("%x", Type) << " Addend: 0x" << format("%llx", Addend)
566 << " SymOffset: " << format("%x", SymOffset)
571 llvm_unreachable("Not implemented relocation type!");
573 case ELF::R_MIPS_JALR:
574 case ELF::R_MIPS_NONE:
578 return Value + Addend;
580 return ((Value + Addend) >> 2) & 0x3ffffff;
581 case ELF::R_MIPS_GPREL16: {
582 uint64_t GOTAddr = getSectionLoadAddress(SectionToGOTMap[SectionID]);
583 return Value + Addend - (GOTAddr + 0x7ff0);
585 case ELF::R_MIPS_SUB:
586 return Value - Addend;
587 case ELF::R_MIPS_HI16:
588 // Get the higher 16-bits. Also add 1 if bit 15 is 1.
589 return ((Value + Addend + 0x8000) >> 16) & 0xffff;
590 case ELF::R_MIPS_LO16:
591 return (Value + Addend) & 0xffff;
592 case ELF::R_MIPS_CALL16:
593 case ELF::R_MIPS_GOT_DISP:
594 case ELF::R_MIPS_GOT_PAGE: {
595 uint8_t *LocalGOTAddr =
596 getSectionAddress(SectionToGOTMap[SectionID]) + SymOffset;
597 uint64_t GOTEntry = readBytesUnaligned(LocalGOTAddr, 8);
600 if (Type == ELF::R_MIPS_GOT_PAGE)
601 Value = (Value + 0x8000) & ~0xffff;
604 assert(GOTEntry == Value &&
605 "GOT entry has two different addresses.");
607 writeBytesUnaligned(Value, LocalGOTAddr, 8);
609 return (SymOffset - 0x7ff0) & 0xffff;
611 case ELF::R_MIPS_GOT_OFST: {
612 int64_t page = (Value + Addend + 0x8000) & ~0xffff;
613 return (Value + Addend - page) & 0xffff;
615 case ELF::R_MIPS_GPREL32: {
616 uint64_t GOTAddr = getSectionLoadAddress(SectionToGOTMap[SectionID]);
617 return Value + Addend - (GOTAddr + 0x7ff0);
619 case ELF::R_MIPS_PC16: {
620 uint64_t FinalAddress = (Section.LoadAddress + Offset);
621 return ((Value + Addend - FinalAddress - 4) >> 2) & 0xffff;
623 case ELF::R_MIPS_PC18_S3: {
624 uint64_t FinalAddress = (Section.LoadAddress + Offset);
625 return ((Value + Addend - ((FinalAddress | 7) ^ 7)) >> 3) & 0x3ffff;
627 case ELF::R_MIPS_PC19_S2: {
628 uint64_t FinalAddress = (Section.LoadAddress + Offset);
629 return ((Value + Addend - FinalAddress) >> 2) & 0x7ffff;
631 case ELF::R_MIPS_PC21_S2: {
632 uint64_t FinalAddress = (Section.LoadAddress + Offset);
633 return ((Value + Addend - FinalAddress) >> 2) & 0x1fffff;
635 case ELF::R_MIPS_PC26_S2: {
636 uint64_t FinalAddress = (Section.LoadAddress + Offset);
637 return ((Value + Addend - FinalAddress) >> 2) & 0x3ffffff;
639 case ELF::R_MIPS_PCHI16: {
640 uint64_t FinalAddress = (Section.LoadAddress + Offset);
641 return ((Value + Addend - FinalAddress + 0x8000) >> 16) & 0xffff;
643 case ELF::R_MIPS_PCLO16: {
644 uint64_t FinalAddress = (Section.LoadAddress + Offset);
645 return (Value + Addend - FinalAddress) & 0xffff;
651 void RuntimeDyldELF::applyMIPS64Relocation(uint8_t *TargetPtr,
652 int64_t CalculatedValue,
654 uint32_t Insn = readBytesUnaligned(TargetPtr, 4);
660 case ELF::R_MIPS_GPREL32:
661 writeBytesUnaligned(CalculatedValue & 0xffffffff, TargetPtr, 4);
664 case ELF::R_MIPS_SUB:
665 writeBytesUnaligned(CalculatedValue, TargetPtr, 8);
668 case ELF::R_MIPS_PC26_S2:
669 Insn = (Insn & 0xfc000000) | CalculatedValue;
670 writeBytesUnaligned(Insn, TargetPtr, 4);
672 case ELF::R_MIPS_GPREL16:
673 Insn = (Insn & 0xffff0000) | (CalculatedValue & 0xffff);
674 writeBytesUnaligned(Insn, TargetPtr, 4);
676 case ELF::R_MIPS_HI16:
677 case ELF::R_MIPS_LO16:
678 case ELF::R_MIPS_PCHI16:
679 case ELF::R_MIPS_PCLO16:
680 case ELF::R_MIPS_PC16:
681 case ELF::R_MIPS_CALL16:
682 case ELF::R_MIPS_GOT_DISP:
683 case ELF::R_MIPS_GOT_PAGE:
684 case ELF::R_MIPS_GOT_OFST:
685 Insn = (Insn & 0xffff0000) | CalculatedValue;
686 writeBytesUnaligned(Insn, TargetPtr, 4);
688 case ELF::R_MIPS_PC18_S3:
689 Insn = (Insn & 0xfffc0000) | CalculatedValue;
690 writeBytesUnaligned(Insn, TargetPtr, 4);
692 case ELF::R_MIPS_PC19_S2:
693 Insn = (Insn & 0xfff80000) | CalculatedValue;
694 writeBytesUnaligned(Insn, TargetPtr, 4);
696 case ELF::R_MIPS_PC21_S2:
697 Insn = (Insn & 0xffe00000) | CalculatedValue;
698 writeBytesUnaligned(Insn, TargetPtr, 4);
703 // Return the .TOC. section and offset.
704 void RuntimeDyldELF::findPPC64TOCSection(const ObjectFile &Obj,
705 ObjSectionToIDMap &LocalSections,
706 RelocationValueRef &Rel) {
707 // Set a default SectionID in case we do not find a TOC section below.
708 // This may happen for references to TOC base base (sym@toc, .odp
709 // relocation) without a .toc directive. In this case just use the
710 // first section (which is usually the .odp) since the code won't
711 // reference the .toc base directly.
712 Rel.SymbolName = NULL;
715 // The TOC consists of sections .got, .toc, .tocbss, .plt in that
716 // order. The TOC starts where the first of these sections starts.
717 for (section_iterator si = Obj.section_begin(), se = Obj.section_end();
720 StringRef SectionName;
721 check(si->getName(SectionName));
723 if (SectionName == ".got"
724 || SectionName == ".toc"
725 || SectionName == ".tocbss"
726 || SectionName == ".plt") {
727 Rel.SectionID = findOrEmitSection(Obj, *si, false, LocalSections);
732 // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000
733 // thus permitting a full 64 Kbytes segment.
737 // Returns the sections and offset associated with the ODP entry referenced
739 void RuntimeDyldELF::findOPDEntrySection(const ObjectFile &Obj,
740 ObjSectionToIDMap &LocalSections,
741 RelocationValueRef &Rel) {
742 // Get the ELF symbol value (st_value) to compare with Relocation offset in
744 for (section_iterator si = Obj.section_begin(), se = Obj.section_end();
746 section_iterator RelSecI = si->getRelocatedSection();
747 if (RelSecI == Obj.section_end())
750 StringRef RelSectionName;
751 check(RelSecI->getName(RelSectionName));
752 if (RelSectionName != ".opd")
755 for (relocation_iterator i = si->relocation_begin(),
756 e = si->relocation_end();
758 // The R_PPC64_ADDR64 relocation indicates the first field
761 check(i->getType(TypeFunc));
762 if (TypeFunc != ELF::R_PPC64_ADDR64) {
767 uint64_t TargetSymbolOffset;
768 symbol_iterator TargetSymbol = i->getSymbol();
769 check(i->getOffset(TargetSymbolOffset));
771 check(getELFRelocationAddend(*i, Addend));
777 // Just check if following relocation is a R_PPC64_TOC
779 check(i->getType(TypeTOC));
780 if (TypeTOC != ELF::R_PPC64_TOC)
783 // Finally compares the Symbol value and the target symbol offset
784 // to check if this .opd entry refers to the symbol the relocation
786 if (Rel.Addend != (int64_t)TargetSymbolOffset)
789 section_iterator tsi(Obj.section_end());
790 check(TargetSymbol->getSection(tsi));
791 bool IsCode = tsi->isText();
792 Rel.SectionID = findOrEmitSection(Obj, (*tsi), IsCode, LocalSections);
793 Rel.Addend = (intptr_t)Addend;
797 llvm_unreachable("Attempting to get address of ODP entry!");
800 // Relocation masks following the #lo(value), #hi(value), #ha(value),
801 // #higher(value), #highera(value), #highest(value), and #highesta(value)
802 // macros defined in section 4.5.1. Relocation Types of the PPC-elf64abi
805 static inline uint16_t applyPPClo(uint64_t value) { return value & 0xffff; }
807 static inline uint16_t applyPPChi(uint64_t value) {
808 return (value >> 16) & 0xffff;
811 static inline uint16_t applyPPCha (uint64_t value) {
812 return ((value + 0x8000) >> 16) & 0xffff;
815 static inline uint16_t applyPPChigher(uint64_t value) {
816 return (value >> 32) & 0xffff;
819 static inline uint16_t applyPPChighera (uint64_t value) {
820 return ((value + 0x8000) >> 32) & 0xffff;
823 static inline uint16_t applyPPChighest(uint64_t value) {
824 return (value >> 48) & 0xffff;
827 static inline uint16_t applyPPChighesta (uint64_t value) {
828 return ((value + 0x8000) >> 48) & 0xffff;
831 void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section,
832 uint64_t Offset, uint64_t Value,
833 uint32_t Type, int64_t Addend) {
834 uint8_t *LocalAddress = Section.Address + Offset;
837 llvm_unreachable("Relocation type not implemented yet!");
839 case ELF::R_PPC64_ADDR16:
840 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
842 case ELF::R_PPC64_ADDR16_DS:
843 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
845 case ELF::R_PPC64_ADDR16_LO:
846 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
848 case ELF::R_PPC64_ADDR16_LO_DS:
849 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
851 case ELF::R_PPC64_ADDR16_HI:
852 writeInt16BE(LocalAddress, applyPPChi(Value + Addend));
854 case ELF::R_PPC64_ADDR16_HA:
855 writeInt16BE(LocalAddress, applyPPCha(Value + Addend));
857 case ELF::R_PPC64_ADDR16_HIGHER:
858 writeInt16BE(LocalAddress, applyPPChigher(Value + Addend));
860 case ELF::R_PPC64_ADDR16_HIGHERA:
861 writeInt16BE(LocalAddress, applyPPChighera(Value + Addend));
863 case ELF::R_PPC64_ADDR16_HIGHEST:
864 writeInt16BE(LocalAddress, applyPPChighest(Value + Addend));
866 case ELF::R_PPC64_ADDR16_HIGHESTA:
867 writeInt16BE(LocalAddress, applyPPChighesta(Value + Addend));
869 case ELF::R_PPC64_ADDR14: {
870 assert(((Value + Addend) & 3) == 0);
871 // Preserve the AA/LK bits in the branch instruction
872 uint8_t aalk = *(LocalAddress + 3);
873 writeInt16BE(LocalAddress + 2, (aalk & 3) | ((Value + Addend) & 0xfffc));
875 case ELF::R_PPC64_REL16_LO: {
876 uint64_t FinalAddress = (Section.LoadAddress + Offset);
877 uint64_t Delta = Value - FinalAddress + Addend;
878 writeInt16BE(LocalAddress, applyPPClo(Delta));
880 case ELF::R_PPC64_REL16_HI: {
881 uint64_t FinalAddress = (Section.LoadAddress + Offset);
882 uint64_t Delta = Value - FinalAddress + Addend;
883 writeInt16BE(LocalAddress, applyPPChi(Delta));
885 case ELF::R_PPC64_REL16_HA: {
886 uint64_t FinalAddress = (Section.LoadAddress + Offset);
887 uint64_t Delta = Value - FinalAddress + Addend;
888 writeInt16BE(LocalAddress, applyPPCha(Delta));
890 case ELF::R_PPC64_ADDR32: {
891 int32_t Result = static_cast<int32_t>(Value + Addend);
892 if (SignExtend32<32>(Result) != Result)
893 llvm_unreachable("Relocation R_PPC64_ADDR32 overflow");
894 writeInt32BE(LocalAddress, Result);
896 case ELF::R_PPC64_REL24: {
897 uint64_t FinalAddress = (Section.LoadAddress + Offset);
898 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
899 if (SignExtend32<24>(delta) != delta)
900 llvm_unreachable("Relocation R_PPC64_REL24 overflow");
901 // Generates a 'bl <address>' instruction
902 writeInt32BE(LocalAddress, 0x48000001 | (delta & 0x03FFFFFC));
904 case ELF::R_PPC64_REL32: {
905 uint64_t FinalAddress = (Section.LoadAddress + Offset);
906 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
907 if (SignExtend32<32>(delta) != delta)
908 llvm_unreachable("Relocation R_PPC64_REL32 overflow");
909 writeInt32BE(LocalAddress, delta);
911 case ELF::R_PPC64_REL64: {
912 uint64_t FinalAddress = (Section.LoadAddress + Offset);
913 uint64_t Delta = Value - FinalAddress + Addend;
914 writeInt64BE(LocalAddress, Delta);
916 case ELF::R_PPC64_ADDR64:
917 writeInt64BE(LocalAddress, Value + Addend);
922 void RuntimeDyldELF::resolveSystemZRelocation(const SectionEntry &Section,
923 uint64_t Offset, uint64_t Value,
924 uint32_t Type, int64_t Addend) {
925 uint8_t *LocalAddress = Section.Address + Offset;
928 llvm_unreachable("Relocation type not implemented yet!");
930 case ELF::R_390_PC16DBL:
931 case ELF::R_390_PLT16DBL: {
932 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
933 assert(int16_t(Delta / 2) * 2 == Delta && "R_390_PC16DBL overflow");
934 writeInt16BE(LocalAddress, Delta / 2);
937 case ELF::R_390_PC32DBL:
938 case ELF::R_390_PLT32DBL: {
939 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
940 assert(int32_t(Delta / 2) * 2 == Delta && "R_390_PC32DBL overflow");
941 writeInt32BE(LocalAddress, Delta / 2);
944 case ELF::R_390_PC32: {
945 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
946 assert(int32_t(Delta) == Delta && "R_390_PC32 overflow");
947 writeInt32BE(LocalAddress, Delta);
951 writeInt64BE(LocalAddress, Value + Addend);
956 // The target location for the relocation is described by RE.SectionID and
957 // RE.Offset. RE.SectionID can be used to find the SectionEntry. Each
958 // SectionEntry has three members describing its location.
959 // SectionEntry::Address is the address at which the section has been loaded
960 // into memory in the current (host) process. SectionEntry::LoadAddress is the
961 // address that the section will have in the target process.
962 // SectionEntry::ObjAddress is the address of the bits for this section in the
963 // original emitted object image (also in the current address space).
965 // Relocations will be applied as if the section were loaded at
966 // SectionEntry::LoadAddress, but they will be applied at an address based
967 // on SectionEntry::Address. SectionEntry::ObjAddress will be used to refer to
968 // Target memory contents if they are required for value calculations.
970 // The Value parameter here is the load address of the symbol for the
971 // relocation to be applied. For relocations which refer to symbols in the
972 // current object Value will be the LoadAddress of the section in which
973 // the symbol resides (RE.Addend provides additional information about the
974 // symbol location). For external symbols, Value will be the address of the
975 // symbol in the target address space.
976 void RuntimeDyldELF::resolveRelocation(const RelocationEntry &RE,
978 const SectionEntry &Section = Sections[RE.SectionID];
979 return resolveRelocation(Section, RE.Offset, Value, RE.RelType, RE.Addend,
980 RE.SymOffset, RE.SectionID);
983 void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section,
984 uint64_t Offset, uint64_t Value,
985 uint32_t Type, int64_t Addend,
986 uint64_t SymOffset, SID SectionID) {
989 resolveX86_64Relocation(Section, Offset, Value, Type, Addend, SymOffset);
992 resolveX86Relocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
993 (uint32_t)(Addend & 0xffffffffL));
995 case Triple::aarch64:
996 case Triple::aarch64_be:
997 resolveAArch64Relocation(Section, Offset, Value, Type, Addend);
999 case Triple::arm: // Fall through.
1002 case Triple::thumbeb:
1003 resolveARMRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
1004 (uint32_t)(Addend & 0xffffffffL));
1006 case Triple::mips: // Fall through.
1007 case Triple::mipsel:
1008 case Triple::mips64:
1009 case Triple::mips64el:
1011 resolveMIPSRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL),
1012 Type, (uint32_t)(Addend & 0xffffffffL));
1013 else if (IsMipsN64ABI)
1014 resolveMIPS64Relocation(Section, Offset, Value, Type, Addend, SymOffset,
1017 llvm_unreachable("Mips ABI not handled");
1019 case Triple::ppc64: // Fall through.
1020 case Triple::ppc64le:
1021 resolvePPC64Relocation(Section, Offset, Value, Type, Addend);
1023 case Triple::systemz:
1024 resolveSystemZRelocation(Section, Offset, Value, Type, Addend);
1027 llvm_unreachable("Unsupported CPU type!");
1031 void *RuntimeDyldELF::computePlaceholderAddress(unsigned SectionID, uint64_t Offset) const {
1032 return (void*)(Sections[SectionID].ObjAddress + Offset);
1035 void RuntimeDyldELF::processSimpleRelocation(unsigned SectionID, uint64_t Offset, unsigned RelType, RelocationValueRef Value) {
1036 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend, Value.Offset);
1037 if (Value.SymbolName)
1038 addRelocationForSymbol(RE, Value.SymbolName);
1040 addRelocationForSection(RE, Value.SectionID);
1043 relocation_iterator RuntimeDyldELF::processRelocationRef(
1044 unsigned SectionID, relocation_iterator RelI,
1045 const ObjectFile &Obj,
1046 ObjSectionToIDMap &ObjSectionToID,
1049 Check(RelI->getType(RelType));
1051 Check(getELFRelocationAddend(*RelI, Addend));
1052 symbol_iterator Symbol = RelI->getSymbol();
1054 // Obtain the symbol name which is referenced in the relocation
1055 StringRef TargetName;
1056 if (Symbol != Obj.symbol_end())
1057 Symbol->getName(TargetName);
1058 DEBUG(dbgs() << "\t\tRelType: " << RelType << " Addend: " << Addend
1059 << " TargetName: " << TargetName << "\n");
1060 RelocationValueRef Value;
1061 // First search for the symbol in the local symbol table
1062 SymbolRef::Type SymType = SymbolRef::ST_Unknown;
1064 // Search for the symbol in the global symbol table
1065 RTDyldSymbolTable::const_iterator gsi = GlobalSymbolTable.end();
1066 if (Symbol != Obj.symbol_end()) {
1067 gsi = GlobalSymbolTable.find(TargetName.data());
1068 Symbol->getType(SymType);
1070 if (gsi != GlobalSymbolTable.end()) {
1071 const auto &SymInfo = gsi->second;
1072 Value.SectionID = SymInfo.getSectionID();
1073 Value.Offset = SymInfo.getOffset();
1074 Value.Addend = SymInfo.getOffset() + Addend;
1077 case SymbolRef::ST_Debug: {
1078 // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously
1079 // and can be changed by another developers. Maybe best way is add
1080 // a new symbol type ST_Section to SymbolRef and use it.
1081 section_iterator si(Obj.section_end());
1082 Symbol->getSection(si);
1083 if (si == Obj.section_end())
1084 llvm_unreachable("Symbol section not found, bad object file format!");
1085 DEBUG(dbgs() << "\t\tThis is section symbol\n");
1086 bool isCode = si->isText();
1087 Value.SectionID = findOrEmitSection(Obj, (*si), isCode, ObjSectionToID);
1088 Value.Addend = Addend;
1091 case SymbolRef::ST_Data:
1092 case SymbolRef::ST_Unknown: {
1093 Value.SymbolName = TargetName.data();
1094 Value.Addend = Addend;
1096 // Absolute relocations will have a zero symbol ID (STN_UNDEF), which
1097 // will manifest here as a NULL symbol name.
1098 // We can set this as a valid (but empty) symbol name, and rely
1099 // on addRelocationForSymbol to handle this.
1100 if (!Value.SymbolName)
1101 Value.SymbolName = "";
1105 llvm_unreachable("Unresolved symbol type!");
1111 Check(RelI->getOffset(Offset));
1113 DEBUG(dbgs() << "\t\tSectionID: " << SectionID << " Offset: " << Offset
1115 if ((Arch == Triple::aarch64 || Arch == Triple::aarch64_be) &&
1116 (RelType == ELF::R_AARCH64_CALL26 || RelType == ELF::R_AARCH64_JUMP26)) {
1117 // This is an AArch64 branch relocation, need to use a stub function.
1118 DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation.");
1119 SectionEntry &Section = Sections[SectionID];
1121 // Look for an existing stub.
1122 StubMap::const_iterator i = Stubs.find(Value);
1123 if (i != Stubs.end()) {
1124 resolveRelocation(Section, Offset, (uint64_t)Section.Address + i->second,
1126 DEBUG(dbgs() << " Stub function found\n");
1128 // Create a new stub function.
1129 DEBUG(dbgs() << " Create a new stub function\n");
1130 Stubs[Value] = Section.StubOffset;
1131 uint8_t *StubTargetAddr =
1132 createStubFunction(Section.Address + Section.StubOffset);
1134 RelocationEntry REmovz_g3(SectionID, StubTargetAddr - Section.Address,
1135 ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend);
1136 RelocationEntry REmovk_g2(SectionID, StubTargetAddr - Section.Address + 4,
1137 ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend);
1138 RelocationEntry REmovk_g1(SectionID, StubTargetAddr - Section.Address + 8,
1139 ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend);
1140 RelocationEntry REmovk_g0(SectionID,
1141 StubTargetAddr - Section.Address + 12,
1142 ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend);
1144 if (Value.SymbolName) {
1145 addRelocationForSymbol(REmovz_g3, Value.SymbolName);
1146 addRelocationForSymbol(REmovk_g2, Value.SymbolName);
1147 addRelocationForSymbol(REmovk_g1, Value.SymbolName);
1148 addRelocationForSymbol(REmovk_g0, Value.SymbolName);
1150 addRelocationForSection(REmovz_g3, Value.SectionID);
1151 addRelocationForSection(REmovk_g2, Value.SectionID);
1152 addRelocationForSection(REmovk_g1, Value.SectionID);
1153 addRelocationForSection(REmovk_g0, Value.SectionID);
1155 resolveRelocation(Section, Offset,
1156 (uint64_t)Section.Address + Section.StubOffset, RelType,
1158 Section.StubOffset += getMaxStubSize();
1160 } else if (Arch == Triple::arm) {
1161 if (RelType == ELF::R_ARM_PC24 || RelType == ELF::R_ARM_CALL ||
1162 RelType == ELF::R_ARM_JUMP24) {
1163 // This is an ARM branch relocation, need to use a stub function.
1164 DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.");
1165 SectionEntry &Section = Sections[SectionID];
1167 // Look for an existing stub.
1168 StubMap::const_iterator i = Stubs.find(Value);
1169 if (i != Stubs.end()) {
1170 resolveRelocation(Section, Offset, (uint64_t)Section.Address + i->second,
1172 DEBUG(dbgs() << " Stub function found\n");
1174 // Create a new stub function.
1175 DEBUG(dbgs() << " Create a new stub function\n");
1176 Stubs[Value] = Section.StubOffset;
1177 uint8_t *StubTargetAddr =
1178 createStubFunction(Section.Address + Section.StubOffset);
1179 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1180 ELF::R_ARM_ABS32, Value.Addend);
1181 if (Value.SymbolName)
1182 addRelocationForSymbol(RE, Value.SymbolName);
1184 addRelocationForSection(RE, Value.SectionID);
1186 resolveRelocation(Section, Offset,
1187 (uint64_t)Section.Address + Section.StubOffset, RelType,
1189 Section.StubOffset += getMaxStubSize();
1192 uint32_t *Placeholder =
1193 reinterpret_cast<uint32_t*>(computePlaceholderAddress(SectionID, Offset));
1194 if (RelType == ELF::R_ARM_PREL31 || RelType == ELF::R_ARM_TARGET1 ||
1195 RelType == ELF::R_ARM_ABS32) {
1196 Value.Addend += *Placeholder;
1197 } else if (RelType == ELF::R_ARM_MOVW_ABS_NC || RelType == ELF::R_ARM_MOVT_ABS) {
1198 // See ELF for ARM documentation
1199 Value.Addend += (int16_t)((*Placeholder & 0xFFF) | (((*Placeholder >> 16) & 0xF) << 12));
1201 processSimpleRelocation(SectionID, Offset, RelType, Value);
1203 } else if (IsMipsO32ABI) {
1204 uint32_t *Placeholder = reinterpret_cast<uint32_t*>(computePlaceholderAddress(SectionID, Offset));
1205 if (RelType == ELF::R_MIPS_26) {
1206 // This is an Mips branch relocation, need to use a stub function.
1207 DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
1208 SectionEntry &Section = Sections[SectionID];
1210 // Extract the addend from the instruction.
1211 // We shift up by two since the Value will be down shifted again
1212 // when applying the relocation.
1213 uint32_t Addend = ((*Placeholder) & 0x03ffffff) << 2;
1215 Value.Addend += Addend;
1217 // Look up for existing stub.
1218 StubMap::const_iterator i = Stubs.find(Value);
1219 if (i != Stubs.end()) {
1220 RelocationEntry RE(SectionID, Offset, RelType, i->second);
1221 addRelocationForSection(RE, SectionID);
1222 DEBUG(dbgs() << " Stub function found\n");
1224 // Create a new stub function.
1225 DEBUG(dbgs() << " Create a new stub function\n");
1226 Stubs[Value] = Section.StubOffset;
1227 uint8_t *StubTargetAddr =
1228 createStubFunction(Section.Address + Section.StubOffset);
1230 // Creating Hi and Lo relocations for the filled stub instructions.
1231 RelocationEntry REHi(SectionID, StubTargetAddr - Section.Address,
1232 ELF::R_MIPS_HI16, Value.Addend);
1233 RelocationEntry RELo(SectionID, StubTargetAddr - Section.Address + 4,
1234 ELF::R_MIPS_LO16, Value.Addend);
1236 if (Value.SymbolName) {
1237 addRelocationForSymbol(REHi, Value.SymbolName);
1238 addRelocationForSymbol(RELo, Value.SymbolName);
1241 addRelocationForSection(REHi, Value.SectionID);
1242 addRelocationForSection(RELo, Value.SectionID);
1245 RelocationEntry RE(SectionID, Offset, RelType, Section.StubOffset);
1246 addRelocationForSection(RE, SectionID);
1247 Section.StubOffset += getMaxStubSize();
1250 if (RelType == ELF::R_MIPS_HI16)
1251 Value.Addend += ((*Placeholder) & 0x0000ffff) << 16;
1252 else if (RelType == ELF::R_MIPS_LO16)
1253 Value.Addend += ((*Placeholder) & 0x0000ffff);
1254 else if (RelType == ELF::R_MIPS_32)
1255 Value.Addend += *Placeholder;
1256 processSimpleRelocation(SectionID, Offset, RelType, Value);
1258 } else if (IsMipsN64ABI) {
1259 uint32_t r_type = RelType & 0xff;
1260 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1261 if (r_type == ELF::R_MIPS_CALL16 || r_type == ELF::R_MIPS_GOT_PAGE
1262 || r_type == ELF::R_MIPS_GOT_DISP) {
1263 StringMap<uint64_t>::iterator i = GOTSymbolOffsets.find(TargetName);
1264 if (i != GOTSymbolOffsets.end())
1265 RE.SymOffset = i->second;
1267 RE.SymOffset = allocateGOTEntries(SectionID, 1);
1268 GOTSymbolOffsets[TargetName] = RE.SymOffset;
1271 if (Value.SymbolName)
1272 addRelocationForSymbol(RE, Value.SymbolName);
1274 addRelocationForSection(RE, Value.SectionID);
1275 } else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) {
1276 if (RelType == ELF::R_PPC64_REL24) {
1277 // Determine ABI variant in use for this object.
1278 unsigned AbiVariant;
1279 Obj.getPlatformFlags(AbiVariant);
1280 AbiVariant &= ELF::EF_PPC64_ABI;
1281 // A PPC branch relocation will need a stub function if the target is
1282 // an external symbol (Symbol::ST_Unknown) or if the target address
1283 // is not within the signed 24-bits branch address.
1284 SectionEntry &Section = Sections[SectionID];
1285 uint8_t *Target = Section.Address + Offset;
1286 bool RangeOverflow = false;
1287 if (SymType != SymbolRef::ST_Unknown) {
1288 if (AbiVariant != 2) {
1289 // In the ELFv1 ABI, a function call may point to the .opd entry,
1290 // so the final symbol value is calculated based on the relocation
1291 // values in the .opd section.
1292 findOPDEntrySection(Obj, ObjSectionToID, Value);
1294 // In the ELFv2 ABI, a function symbol may provide a local entry
1295 // point, which must be used for direct calls.
1297 Symbol->getOther(SymOther);
1298 Value.Addend += ELF::decodePPC64LocalEntryOffset(SymOther);
1300 uint8_t *RelocTarget = Sections[Value.SectionID].Address + Value.Addend;
1301 int32_t delta = static_cast<int32_t>(Target - RelocTarget);
1302 // If it is within 24-bits branch range, just set the branch target
1303 if (SignExtend32<24>(delta) == delta) {
1304 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1305 if (Value.SymbolName)
1306 addRelocationForSymbol(RE, Value.SymbolName);
1308 addRelocationForSection(RE, Value.SectionID);
1310 RangeOverflow = true;
1313 if (SymType == SymbolRef::ST_Unknown || RangeOverflow) {
1314 // It is an external symbol (SymbolRef::ST_Unknown) or within a range
1315 // larger than 24-bits.
1316 StubMap::const_iterator i = Stubs.find(Value);
1317 if (i != Stubs.end()) {
1318 // Symbol function stub already created, just relocate to it
1319 resolveRelocation(Section, Offset,
1320 (uint64_t)Section.Address + i->second, RelType, 0);
1321 DEBUG(dbgs() << " Stub function found\n");
1323 // Create a new stub function.
1324 DEBUG(dbgs() << " Create a new stub function\n");
1325 Stubs[Value] = Section.StubOffset;
1326 uint8_t *StubTargetAddr =
1327 createStubFunction(Section.Address + Section.StubOffset,
1329 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1330 ELF::R_PPC64_ADDR64, Value.Addend);
1332 // Generates the 64-bits address loads as exemplified in section
1333 // 4.5.1 in PPC64 ELF ABI. Note that the relocations need to
1334 // apply to the low part of the instructions, so we have to update
1335 // the offset according to the target endianness.
1336 uint64_t StubRelocOffset = StubTargetAddr - Section.Address;
1337 if (!IsTargetLittleEndian)
1338 StubRelocOffset += 2;
1340 RelocationEntry REhst(SectionID, StubRelocOffset + 0,
1341 ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend);
1342 RelocationEntry REhr(SectionID, StubRelocOffset + 4,
1343 ELF::R_PPC64_ADDR16_HIGHER, Value.Addend);
1344 RelocationEntry REh(SectionID, StubRelocOffset + 12,
1345 ELF::R_PPC64_ADDR16_HI, Value.Addend);
1346 RelocationEntry REl(SectionID, StubRelocOffset + 16,
1347 ELF::R_PPC64_ADDR16_LO, Value.Addend);
1349 if (Value.SymbolName) {
1350 addRelocationForSymbol(REhst, Value.SymbolName);
1351 addRelocationForSymbol(REhr, Value.SymbolName);
1352 addRelocationForSymbol(REh, Value.SymbolName);
1353 addRelocationForSymbol(REl, Value.SymbolName);
1355 addRelocationForSection(REhst, Value.SectionID);
1356 addRelocationForSection(REhr, Value.SectionID);
1357 addRelocationForSection(REh, Value.SectionID);
1358 addRelocationForSection(REl, Value.SectionID);
1361 resolveRelocation(Section, Offset,
1362 (uint64_t)Section.Address + Section.StubOffset,
1364 Section.StubOffset += getMaxStubSize();
1366 if (SymType == SymbolRef::ST_Unknown) {
1367 // Restore the TOC for external calls
1368 if (AbiVariant == 2)
1369 writeInt32BE(Target + 4, 0xE8410018); // ld r2,28(r1)
1371 writeInt32BE(Target + 4, 0xE8410028); // ld r2,40(r1)
1374 } else if (RelType == ELF::R_PPC64_TOC16 ||
1375 RelType == ELF::R_PPC64_TOC16_DS ||
1376 RelType == ELF::R_PPC64_TOC16_LO ||
1377 RelType == ELF::R_PPC64_TOC16_LO_DS ||
1378 RelType == ELF::R_PPC64_TOC16_HI ||
1379 RelType == ELF::R_PPC64_TOC16_HA) {
1380 // These relocations are supposed to subtract the TOC address from
1381 // the final value. This does not fit cleanly into the RuntimeDyld
1382 // scheme, since there may be *two* sections involved in determining
1383 // the relocation value (the section of the symbol refered to by the
1384 // relocation, and the TOC section associated with the current module).
1386 // Fortunately, these relocations are currently only ever generated
1387 // refering to symbols that themselves reside in the TOC, which means
1388 // that the two sections are actually the same. Thus they cancel out
1389 // and we can immediately resolve the relocation right now.
1391 case ELF::R_PPC64_TOC16: RelType = ELF::R_PPC64_ADDR16; break;
1392 case ELF::R_PPC64_TOC16_DS: RelType = ELF::R_PPC64_ADDR16_DS; break;
1393 case ELF::R_PPC64_TOC16_LO: RelType = ELF::R_PPC64_ADDR16_LO; break;
1394 case ELF::R_PPC64_TOC16_LO_DS: RelType = ELF::R_PPC64_ADDR16_LO_DS; break;
1395 case ELF::R_PPC64_TOC16_HI: RelType = ELF::R_PPC64_ADDR16_HI; break;
1396 case ELF::R_PPC64_TOC16_HA: RelType = ELF::R_PPC64_ADDR16_HA; break;
1397 default: llvm_unreachable("Wrong relocation type.");
1400 RelocationValueRef TOCValue;
1401 findPPC64TOCSection(Obj, ObjSectionToID, TOCValue);
1402 if (Value.SymbolName || Value.SectionID != TOCValue.SectionID)
1403 llvm_unreachable("Unsupported TOC relocation.");
1404 Value.Addend -= TOCValue.Addend;
1405 resolveRelocation(Sections[SectionID], Offset, Value.Addend, RelType, 0);
1407 // There are two ways to refer to the TOC address directly: either
1408 // via a ELF::R_PPC64_TOC relocation (where both symbol and addend are
1409 // ignored), or via any relocation that refers to the magic ".TOC."
1410 // symbols (in which case the addend is respected).
1411 if (RelType == ELF::R_PPC64_TOC) {
1412 RelType = ELF::R_PPC64_ADDR64;
1413 findPPC64TOCSection(Obj, ObjSectionToID, Value);
1414 } else if (TargetName == ".TOC.") {
1415 findPPC64TOCSection(Obj, ObjSectionToID, Value);
1416 Value.Addend += Addend;
1419 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1421 if (Value.SymbolName)
1422 addRelocationForSymbol(RE, Value.SymbolName);
1424 addRelocationForSection(RE, Value.SectionID);
1426 } else if (Arch == Triple::systemz &&
1427 (RelType == ELF::R_390_PLT32DBL || RelType == ELF::R_390_GOTENT)) {
1428 // Create function stubs for both PLT and GOT references, regardless of
1429 // whether the GOT reference is to data or code. The stub contains the
1430 // full address of the symbol, as needed by GOT references, and the
1431 // executable part only adds an overhead of 8 bytes.
1433 // We could try to conserve space by allocating the code and data
1434 // parts of the stub separately. However, as things stand, we allocate
1435 // a stub for every relocation, so using a GOT in JIT code should be
1436 // no less space efficient than using an explicit constant pool.
1437 DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation.");
1438 SectionEntry &Section = Sections[SectionID];
1440 // Look for an existing stub.
1441 StubMap::const_iterator i = Stubs.find(Value);
1442 uintptr_t StubAddress;
1443 if (i != Stubs.end()) {
1444 StubAddress = uintptr_t(Section.Address) + i->second;
1445 DEBUG(dbgs() << " Stub function found\n");
1447 // Create a new stub function.
1448 DEBUG(dbgs() << " Create a new stub function\n");
1450 uintptr_t BaseAddress = uintptr_t(Section.Address);
1451 uintptr_t StubAlignment = getStubAlignment();
1452 StubAddress = (BaseAddress + Section.StubOffset + StubAlignment - 1) &
1454 unsigned StubOffset = StubAddress - BaseAddress;
1456 Stubs[Value] = StubOffset;
1457 createStubFunction((uint8_t *)StubAddress);
1458 RelocationEntry RE(SectionID, StubOffset + 8, ELF::R_390_64,
1460 if (Value.SymbolName)
1461 addRelocationForSymbol(RE, Value.SymbolName);
1463 addRelocationForSection(RE, Value.SectionID);
1464 Section.StubOffset = StubOffset + getMaxStubSize();
1467 if (RelType == ELF::R_390_GOTENT)
1468 resolveRelocation(Section, Offset, StubAddress + 8, ELF::R_390_PC32DBL,
1471 resolveRelocation(Section, Offset, StubAddress, RelType, Addend);
1472 } else if (Arch == Triple::x86_64) {
1473 if (RelType == ELF::R_X86_64_PLT32) {
1474 // The way the PLT relocations normally work is that the linker allocates
1476 // PLT and this relocation makes a PC-relative call into the PLT. The PLT
1477 // entry will then jump to an address provided by the GOT. On first call,
1479 // GOT address will point back into PLT code that resolves the symbol. After
1480 // the first call, the GOT entry points to the actual function.
1482 // For local functions we're ignoring all of that here and just replacing
1483 // the PLT32 relocation type with PC32, which will translate the relocation
1484 // into a PC-relative call directly to the function. For external symbols we
1485 // can't be sure the function will be within 2^32 bytes of the call site, so
1486 // we need to create a stub, which calls into the GOT. This case is
1487 // equivalent to the usual PLT implementation except that we use the stub
1488 // mechanism in RuntimeDyld (which puts stubs at the end of the section)
1489 // rather than allocating a PLT section.
1490 if (Value.SymbolName) {
1491 // This is a call to an external function.
1492 // Look for an existing stub.
1493 SectionEntry &Section = Sections[SectionID];
1494 StubMap::const_iterator i = Stubs.find(Value);
1495 uintptr_t StubAddress;
1496 if (i != Stubs.end()) {
1497 StubAddress = uintptr_t(Section.Address) + i->second;
1498 DEBUG(dbgs() << " Stub function found\n");
1500 // Create a new stub function (equivalent to a PLT entry).
1501 DEBUG(dbgs() << " Create a new stub function\n");
1503 uintptr_t BaseAddress = uintptr_t(Section.Address);
1504 uintptr_t StubAlignment = getStubAlignment();
1505 StubAddress = (BaseAddress + Section.StubOffset + StubAlignment - 1) &
1507 unsigned StubOffset = StubAddress - BaseAddress;
1508 Stubs[Value] = StubOffset;
1509 createStubFunction((uint8_t *)StubAddress);
1511 // Bump our stub offset counter
1512 Section.StubOffset = StubOffset + getMaxStubSize();
1514 // Allocate a GOT Entry
1515 uint64_t GOTOffset = allocateGOTEntries(SectionID, 1);
1517 // The load of the GOT address has an addend of -4
1518 resolveGOTOffsetRelocation(SectionID, StubOffset + 2, GOTOffset - 4);
1520 // Fill in the value of the symbol we're targeting into the GOT
1521 addRelocationForSymbol(computeGOTOffsetRE(SectionID,GOTOffset,0,ELF::R_X86_64_64),
1525 // Make the target call a call into the stub table.
1526 resolveRelocation(Section, Offset, StubAddress, ELF::R_X86_64_PC32,
1529 RelocationEntry RE(SectionID, Offset, ELF::R_X86_64_PC32, Value.Addend,
1531 addRelocationForSection(RE, Value.SectionID);
1533 } else if (RelType == ELF::R_X86_64_GOTPCREL) {
1534 uint64_t GOTOffset = allocateGOTEntries(SectionID, 1);
1535 resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend);
1537 // Fill in the value of the symbol we're targeting into the GOT
1538 RelocationEntry RE = computeGOTOffsetRE(SectionID, GOTOffset, Value.Offset, ELF::R_X86_64_64);
1539 if (Value.SymbolName)
1540 addRelocationForSymbol(RE, Value.SymbolName);
1542 addRelocationForSection(RE, Value.SectionID);
1543 } else if (RelType == ELF::R_X86_64_PC32) {
1544 Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset));
1545 processSimpleRelocation(SectionID, Offset, RelType, Value);
1546 } else if (RelType == ELF::R_X86_64_PC64) {
1547 Value.Addend += support::ulittle64_t::ref(computePlaceholderAddress(SectionID, Offset));
1548 processSimpleRelocation(SectionID, Offset, RelType, Value);
1550 processSimpleRelocation(SectionID, Offset, RelType, Value);
1553 if (Arch == Triple::x86) {
1554 Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset));
1556 processSimpleRelocation(SectionID, Offset, RelType, Value);
1561 size_t RuntimeDyldELF::getGOTEntrySize() {
1562 // We don't use the GOT in all of these cases, but it's essentially free
1563 // to put them all here.
1566 case Triple::x86_64:
1567 case Triple::aarch64:
1568 case Triple::aarch64_be:
1570 case Triple::ppc64le:
1571 case Triple::systemz:
1572 Result = sizeof(uint64_t);
1577 Result = sizeof(uint32_t);
1580 case Triple::mipsel:
1581 case Triple::mips64:
1582 case Triple::mips64el:
1584 Result = sizeof(uint32_t);
1585 else if (IsMipsN64ABI)
1586 Result = sizeof(uint64_t);
1588 llvm_unreachable("Mips ABI not handled");
1591 llvm_unreachable("Unsupported CPU type!");
1596 uint64_t RuntimeDyldELF::allocateGOTEntries(unsigned SectionID, unsigned no)
1598 (void)SectionID; // The GOT Section is the same for all section in the object file
1599 if (GOTSectionID == 0) {
1600 GOTSectionID = Sections.size();
1601 // Reserve a section id. We'll allocate the section later
1602 // once we know the total size
1603 Sections.push_back(SectionEntry(".got", 0, 0, 0));
1605 uint64_t StartOffset = CurrentGOTIndex * getGOTEntrySize();
1606 CurrentGOTIndex += no;
1610 void RuntimeDyldELF::resolveGOTOffsetRelocation(unsigned SectionID, uint64_t Offset, uint64_t GOTOffset)
1612 // Fill in the relative address of the GOT Entry into the stub
1613 RelocationEntry GOTRE(SectionID, Offset, ELF::R_X86_64_PC32, GOTOffset);
1614 addRelocationForSection(GOTRE, GOTSectionID);
1617 RelocationEntry RuntimeDyldELF::computeGOTOffsetRE(unsigned SectionID, uint64_t GOTOffset, uint64_t SymbolOffset,
1620 (void)SectionID; // The GOT Section is the same for all section in the object file
1621 return RelocationEntry(GOTSectionID, GOTOffset, Type, SymbolOffset);
1624 void RuntimeDyldELF::finalizeLoad(const ObjectFile &Obj,
1625 ObjSectionToIDMap &SectionMap) {
1626 // If necessary, allocate the global offset table
1627 if (GOTSectionID != 0) {
1628 // Allocate memory for the section
1629 size_t TotalSize = CurrentGOTIndex * getGOTEntrySize();
1630 uint8_t *Addr = MemMgr.allocateDataSection(TotalSize, getGOTEntrySize(),
1631 GOTSectionID, ".got", false);
1633 report_fatal_error("Unable to allocate memory for GOT!");
1635 Sections[GOTSectionID] = SectionEntry(".got", Addr, TotalSize, 0);
1638 Checker->registerSection(Obj.getFileName(), GOTSectionID);
1640 // For now, initialize all GOT entries to zero. We'll fill them in as
1641 // needed when GOT-based relocations are applied.
1642 memset(Addr, 0, TotalSize);
1644 // To correctly resolve Mips GOT relocations, we need a mapping from
1645 // object's sections to GOTs.
1646 for (section_iterator SI = Obj.section_begin(), SE = Obj.section_end();
1648 if (SI->relocation_begin() != SI->relocation_end()) {
1649 section_iterator RelocatedSection = SI->getRelocatedSection();
1650 ObjSectionToIDMap::iterator i = SectionMap.find(*RelocatedSection);
1651 assert (i != SectionMap.end());
1652 SectionToGOTMap[i->second] = GOTSectionID;
1655 GOTSymbolOffsets.clear();
1659 // Look for and record the EH frame section.
1660 ObjSectionToIDMap::iterator i, e;
1661 for (i = SectionMap.begin(), e = SectionMap.end(); i != e; ++i) {
1662 const SectionRef &Section = i->first;
1664 Section.getName(Name);
1665 if (Name == ".eh_frame") {
1666 UnregisteredEHFrameSections.push_back(i->second);
1672 CurrentGOTIndex = 0;
1675 bool RuntimeDyldELF::isCompatibleFile(const object::ObjectFile &Obj) const {