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 "JITRegistrar.h"
16 #include "ObjectImageCommon.h"
17 #include "llvm/ADT/IntervalMap.h"
18 #include "llvm/ADT/STLExtras.h"
19 #include "llvm/ADT/StringRef.h"
20 #include "llvm/ADT/Triple.h"
21 #include "llvm/ExecutionEngine/ObjectBuffer.h"
22 #include "llvm/ExecutionEngine/ObjectImage.h"
23 #include "llvm/Object/ELFObjectFile.h"
24 #include "llvm/Object/ObjectFile.h"
25 #include "llvm/Support/ELF.h"
26 #include "llvm/Support/Endian.h"
27 #include "llvm/Support/MemoryBuffer.h"
30 using namespace llvm::object;
32 #define DEBUG_TYPE "dyld"
36 static inline std::error_code check(std::error_code Err) {
38 report_fatal_error(Err.message());
43 template <class ELFT> class DyldELFObject : public ELFObjectFile<ELFT> {
44 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
46 typedef Elf_Shdr_Impl<ELFT> Elf_Shdr;
47 typedef Elf_Sym_Impl<ELFT> Elf_Sym;
48 typedef Elf_Rel_Impl<ELFT, false> Elf_Rel;
49 typedef Elf_Rel_Impl<ELFT, true> Elf_Rela;
51 typedef Elf_Ehdr_Impl<ELFT> Elf_Ehdr;
53 typedef typename ELFDataTypeTypedefHelper<ELFT>::value_type addr_type;
55 std::unique_ptr<ObjectFile> UnderlyingFile;
58 DyldELFObject(std::unique_ptr<ObjectFile> UnderlyingFile,
59 MemoryBufferRef Wrapper, std::error_code &ec);
61 DyldELFObject(MemoryBufferRef Wrapper, std::error_code &ec);
63 void updateSectionAddress(const SectionRef &Sec, uint64_t Addr);
64 void updateSymbolAddress(const SymbolRef &Sym, uint64_t Addr);
66 // Methods for type inquiry through isa, cast and dyn_cast
67 static inline bool classof(const Binary *v) {
68 return (isa<ELFObjectFile<ELFT>>(v) &&
69 classof(cast<ELFObjectFile<ELFT>>(v)));
71 static inline bool classof(const ELFObjectFile<ELFT> *v) {
72 return v->isDyldType();
76 template <class ELFT> class ELFObjectImage : public ObjectImageCommon {
80 ELFObjectImage(ObjectBuffer *Input, std::unique_ptr<DyldELFObject<ELFT>> Obj)
81 : ObjectImageCommon(Input, std::move(Obj)), Registered(false) {}
83 virtual ~ELFObjectImage() {
85 deregisterWithDebugger();
88 // Subclasses can override these methods to update the image with loaded
89 // addresses for sections and common symbols
90 void updateSectionAddress(const SectionRef &Sec, uint64_t Addr) override {
91 static_cast<DyldELFObject<ELFT>*>(getObjectFile())
92 ->updateSectionAddress(Sec, Addr);
95 void updateSymbolAddress(const SymbolRef &Sym, uint64_t Addr) override {
96 static_cast<DyldELFObject<ELFT>*>(getObjectFile())
97 ->updateSymbolAddress(Sym, Addr);
100 void registerWithDebugger() override {
101 JITRegistrar::getGDBRegistrar().registerObject(*Buffer);
104 void deregisterWithDebugger() override {
105 JITRegistrar::getGDBRegistrar().deregisterObject(*Buffer);
109 // The MemoryBuffer passed into this constructor is just a wrapper around the
110 // actual memory. Ultimately, the Binary parent class will take ownership of
111 // this MemoryBuffer object but not the underlying memory.
112 template <class ELFT>
113 DyldELFObject<ELFT>::DyldELFObject(MemoryBufferRef Wrapper, std::error_code &EC)
114 : ELFObjectFile<ELFT>(Wrapper, EC) {
115 this->isDyldELFObject = true;
118 template <class ELFT>
119 DyldELFObject<ELFT>::DyldELFObject(std::unique_ptr<ObjectFile> UnderlyingFile,
120 MemoryBufferRef Wrapper, std::error_code &EC)
121 : ELFObjectFile<ELFT>(Wrapper, EC),
122 UnderlyingFile(std::move(UnderlyingFile)) {
123 this->isDyldELFObject = true;
126 template <class ELFT>
127 void DyldELFObject<ELFT>::updateSectionAddress(const SectionRef &Sec,
129 DataRefImpl ShdrRef = Sec.getRawDataRefImpl();
131 const_cast<Elf_Shdr *>(reinterpret_cast<const Elf_Shdr *>(ShdrRef.p));
133 // This assumes the address passed in matches the target address bitness
134 // The template-based type cast handles everything else.
135 shdr->sh_addr = static_cast<addr_type>(Addr);
138 template <class ELFT>
139 void DyldELFObject<ELFT>::updateSymbolAddress(const SymbolRef &SymRef,
142 Elf_Sym *sym = const_cast<Elf_Sym *>(
143 ELFObjectFile<ELFT>::getSymbol(SymRef.getRawDataRefImpl()));
145 // This assumes the address passed in matches the target address bitness
146 // The template-based type cast handles everything else.
147 sym->st_value = static_cast<addr_type>(Addr);
154 void RuntimeDyldELF::registerEHFrames() {
157 for (int i = 0, e = UnregisteredEHFrameSections.size(); i != e; ++i) {
158 SID EHFrameSID = UnregisteredEHFrameSections[i];
159 uint8_t *EHFrameAddr = Sections[EHFrameSID].Address;
160 uint64_t EHFrameLoadAddr = Sections[EHFrameSID].LoadAddress;
161 size_t EHFrameSize = Sections[EHFrameSID].Size;
162 MemMgr->registerEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
163 RegisteredEHFrameSections.push_back(EHFrameSID);
165 UnregisteredEHFrameSections.clear();
168 void RuntimeDyldELF::deregisterEHFrames() {
171 for (int i = 0, e = RegisteredEHFrameSections.size(); i != e; ++i) {
172 SID EHFrameSID = RegisteredEHFrameSections[i];
173 uint8_t *EHFrameAddr = Sections[EHFrameSID].Address;
174 uint64_t EHFrameLoadAddr = Sections[EHFrameSID].LoadAddress;
175 size_t EHFrameSize = Sections[EHFrameSID].Size;
176 MemMgr->deregisterEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
178 RegisteredEHFrameSections.clear();
182 RuntimeDyldELF::createObjectImageFromFile(std::unique_ptr<object::ObjectFile> ObjFile) {
187 MemoryBufferRef Buffer = ObjFile->getMemoryBufferRef();
189 if (ObjFile->getBytesInAddress() == 4 && ObjFile->isLittleEndian()) {
191 llvm::make_unique<DyldELFObject<ELFType<support::little, 2, false>>>(
192 std::move(ObjFile), Buffer, ec);
193 return new ELFObjectImage<ELFType<support::little, 2, false>>(
194 nullptr, std::move(Obj));
195 } else if (ObjFile->getBytesInAddress() == 4 && !ObjFile->isLittleEndian()) {
197 llvm::make_unique<DyldELFObject<ELFType<support::big, 2, false>>>(
198 std::move(ObjFile), Buffer, ec);
199 return new ELFObjectImage<ELFType<support::big, 2, false>>(nullptr, std::move(Obj));
200 } else if (ObjFile->getBytesInAddress() == 8 && !ObjFile->isLittleEndian()) {
201 auto Obj = llvm::make_unique<DyldELFObject<ELFType<support::big, 2, true>>>(
202 std::move(ObjFile), Buffer, ec);
203 return new ELFObjectImage<ELFType<support::big, 2, true>>(nullptr,
205 } else if (ObjFile->getBytesInAddress() == 8 && ObjFile->isLittleEndian()) {
207 llvm::make_unique<DyldELFObject<ELFType<support::little, 2, true>>>(
208 std::move(ObjFile), Buffer, ec);
209 return new ELFObjectImage<ELFType<support::little, 2, true>>(
210 nullptr, std::move(Obj));
212 llvm_unreachable("Unexpected ELF format");
215 ObjectImage *RuntimeDyldELF::createObjectImage(ObjectBuffer *Buffer) {
216 if (Buffer->getBufferSize() < ELF::EI_NIDENT)
217 llvm_unreachable("Unexpected ELF object size");
218 std::pair<unsigned char, unsigned char> Ident =
219 std::make_pair((uint8_t)Buffer->getBufferStart()[ELF::EI_CLASS],
220 (uint8_t)Buffer->getBufferStart()[ELF::EI_DATA]);
223 MemoryBufferRef Buf = Buffer->getMemBuffer();
225 if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2LSB) {
227 llvm::make_unique<DyldELFObject<ELFType<support::little, 4, false>>>(
229 return new ELFObjectImage<ELFType<support::little, 4, false>>(
230 Buffer, std::move(Obj));
231 } else if (Ident.first == ELF::ELFCLASS32 &&
232 Ident.second == ELF::ELFDATA2MSB) {
234 llvm::make_unique<DyldELFObject<ELFType<support::big, 4, false>>>(Buf,
236 return new ELFObjectImage<ELFType<support::big, 4, false>>(Buffer,
238 } else if (Ident.first == ELF::ELFCLASS64 &&
239 Ident.second == ELF::ELFDATA2MSB) {
240 auto Obj = llvm::make_unique<DyldELFObject<ELFType<support::big, 8, true>>>(
242 return new ELFObjectImage<ELFType<support::big, 8, true>>(Buffer, std::move(Obj));
243 } else if (Ident.first == ELF::ELFCLASS64 &&
244 Ident.second == ELF::ELFDATA2LSB) {
246 llvm::make_unique<DyldELFObject<ELFType<support::little, 8, true>>>(Buf,
248 return new ELFObjectImage<ELFType<support::little, 8, true>>(Buffer, std::move(Obj));
250 llvm_unreachable("Unexpected ELF format");
253 RuntimeDyldELF::~RuntimeDyldELF() {}
255 void RuntimeDyldELF::resolveX86_64Relocation(const SectionEntry &Section,
256 uint64_t Offset, uint64_t Value,
257 uint32_t Type, int64_t Addend,
258 uint64_t SymOffset) {
261 llvm_unreachable("Relocation type not implemented yet!");
263 case ELF::R_X86_64_64: {
264 support::ulittle64_t::ref(Section.Address + Offset) = Value + Addend;
265 DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend)) << " at "
266 << format("%p\n", Section.Address + Offset));
269 case ELF::R_X86_64_32:
270 case ELF::R_X86_64_32S: {
272 assert((Type == ELF::R_X86_64_32 && (Value <= UINT32_MAX)) ||
273 (Type == ELF::R_X86_64_32S &&
274 ((int64_t)Value <= INT32_MAX && (int64_t)Value >= INT32_MIN)));
275 uint32_t TruncatedAddr = (Value & 0xFFFFFFFF);
276 support::ulittle32_t::ref(Section.Address + Offset) = TruncatedAddr;
277 DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr) << " at "
278 << format("%p\n", Section.Address + Offset));
281 case ELF::R_X86_64_GOTPCREL: {
282 // findGOTEntry returns the 'G + GOT' part of the relocation calculation
283 // based on the load/target address of the GOT (not the current/local addr).
284 uint64_t GOTAddr = findGOTEntry(Value, SymOffset);
285 uint64_t FinalAddress = Section.LoadAddress + Offset;
286 // The processRelocationRef method combines the symbol offset and the addend
287 // and in most cases that's what we want. For this relocation type, we need
288 // the raw addend, so we subtract the symbol offset to get it.
289 int64_t RealOffset = GOTAddr + Addend - SymOffset - FinalAddress;
290 assert(RealOffset <= INT32_MAX && RealOffset >= INT32_MIN);
291 int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
292 support::ulittle32_t::ref(Section.Address + Offset) = TruncOffset;
295 case ELF::R_X86_64_PC32: {
296 // Get the placeholder value from the generated object since
297 // a previous relocation attempt may have overwritten the loaded version
298 support::ulittle32_t::ref Placeholder(
299 (void *)(Section.ObjAddress + Offset));
300 uint64_t FinalAddress = Section.LoadAddress + Offset;
301 int64_t RealOffset = Placeholder + Value + Addend - FinalAddress;
302 assert(RealOffset <= INT32_MAX && RealOffset >= INT32_MIN);
303 int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
304 support::ulittle32_t::ref(Section.Address + Offset) = TruncOffset;
307 case ELF::R_X86_64_PC64: {
308 // Get the placeholder value from the generated object since
309 // a previous relocation attempt may have overwritten the loaded version
310 support::ulittle64_t::ref Placeholder(
311 (void *)(Section.ObjAddress + Offset));
312 uint64_t FinalAddress = Section.LoadAddress + Offset;
313 support::ulittle64_t::ref(Section.Address + Offset) =
314 Placeholder + Value + Addend - FinalAddress;
320 void RuntimeDyldELF::resolveX86Relocation(const SectionEntry &Section,
321 uint64_t Offset, uint32_t Value,
322 uint32_t Type, int32_t Addend) {
324 case ELF::R_386_32: {
325 // Get the placeholder value from the generated object since
326 // a previous relocation attempt may have overwritten the loaded version
327 support::ulittle32_t::ref Placeholder(
328 (void *)(Section.ObjAddress + Offset));
329 support::ulittle32_t::ref(Section.Address + Offset) =
330 Placeholder + Value + Addend;
333 case ELF::R_386_PC32: {
334 // Get the placeholder value from the generated object since
335 // a previous relocation attempt may have overwritten the loaded version
336 support::ulittle32_t::ref Placeholder(
337 (void *)(Section.ObjAddress + Offset));
338 uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
339 uint32_t RealOffset = Placeholder + Value + Addend - FinalAddress;
340 support::ulittle32_t::ref(Section.Address + Offset) = RealOffset;
344 // There are other relocation types, but it appears these are the
345 // only ones currently used by the LLVM ELF object writer
346 llvm_unreachable("Relocation type not implemented yet!");
351 void RuntimeDyldELF::resolveAArch64Relocation(const SectionEntry &Section,
352 uint64_t Offset, uint64_t Value,
353 uint32_t Type, int64_t Addend) {
354 uint32_t *TargetPtr = reinterpret_cast<uint32_t *>(Section.Address + Offset);
355 uint64_t FinalAddress = Section.LoadAddress + Offset;
357 DEBUG(dbgs() << "resolveAArch64Relocation, LocalAddress: 0x"
358 << format("%llx", Section.Address + Offset)
359 << " FinalAddress: 0x" << format("%llx", FinalAddress)
360 << " Value: 0x" << format("%llx", Value) << " Type: 0x"
361 << format("%x", Type) << " Addend: 0x" << format("%llx", Addend)
366 llvm_unreachable("Relocation type not implemented yet!");
368 case ELF::R_AARCH64_ABS64: {
369 uint64_t *TargetPtr =
370 reinterpret_cast<uint64_t *>(Section.Address + Offset);
371 *TargetPtr = Value + Addend;
374 case ELF::R_AARCH64_PREL32: {
375 uint64_t Result = Value + Addend - FinalAddress;
376 assert(static_cast<int64_t>(Result) >= INT32_MIN &&
377 static_cast<int64_t>(Result) <= UINT32_MAX);
378 *TargetPtr = static_cast<uint32_t>(Result & 0xffffffffU);
381 case ELF::R_AARCH64_CALL26: // fallthrough
382 case ELF::R_AARCH64_JUMP26: {
383 // Operation: S+A-P. Set Call or B immediate value to bits fff_fffc of the
385 uint64_t BranchImm = Value + Addend - FinalAddress;
387 // "Check that -2^27 <= result < 2^27".
388 assert(-(1LL << 27) <= static_cast<int64_t>(BranchImm) &&
389 static_cast<int64_t>(BranchImm) < (1LL << 27));
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 &= 0xfc000000U;
394 // Immediate goes in bits 25:0 of B and BL.
395 *TargetPtr |= static_cast<uint32_t>(BranchImm & 0xffffffcU) >> 2;
398 case ELF::R_AARCH64_MOVW_UABS_G3: {
399 uint64_t Result = Value + Addend;
401 // AArch64 code is emitted with .rela relocations. The data already in any
402 // bits affected by the relocation on entry is garbage.
403 *TargetPtr &= 0xffe0001fU;
404 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
405 *TargetPtr |= Result >> (48 - 5);
406 // Shift must be "lsl #48", in bits 22:21
407 assert((*TargetPtr >> 21 & 0x3) == 3 && "invalid shift for relocation");
410 case ELF::R_AARCH64_MOVW_UABS_G2_NC: {
411 uint64_t Result = Value + Addend;
413 // AArch64 code is emitted with .rela relocations. The data already in any
414 // bits affected by the relocation on entry is garbage.
415 *TargetPtr &= 0xffe0001fU;
416 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
417 *TargetPtr |= ((Result & 0xffff00000000ULL) >> (32 - 5));
418 // Shift must be "lsl #32", in bits 22:21
419 assert((*TargetPtr >> 21 & 0x3) == 2 && "invalid shift for relocation");
422 case ELF::R_AARCH64_MOVW_UABS_G1_NC: {
423 uint64_t Result = Value + Addend;
425 // AArch64 code is emitted with .rela relocations. The data already in any
426 // bits affected by the relocation on entry is garbage.
427 *TargetPtr &= 0xffe0001fU;
428 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
429 *TargetPtr |= ((Result & 0xffff0000U) >> (16 - 5));
430 // Shift must be "lsl #16", in bits 22:2
431 assert((*TargetPtr >> 21 & 0x3) == 1 && "invalid shift for relocation");
434 case ELF::R_AARCH64_MOVW_UABS_G0_NC: {
435 uint64_t Result = Value + Addend;
437 // AArch64 code is emitted with .rela relocations. The data already in any
438 // bits affected by the relocation on entry is garbage.
439 *TargetPtr &= 0xffe0001fU;
440 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
441 *TargetPtr |= ((Result & 0xffffU) << 5);
442 // Shift must be "lsl #0", in bits 22:21.
443 assert((*TargetPtr >> 21 & 0x3) == 0 && "invalid shift for relocation");
446 case ELF::R_AARCH64_ADR_PREL_PG_HI21: {
447 // Operation: Page(S+A) - Page(P)
449 ((Value + Addend) & ~0xfffULL) - (FinalAddress & ~0xfffULL);
451 // Check that -2^32 <= X < 2^32
452 assert(static_cast<int64_t>(Result) >= (-1LL << 32) &&
453 static_cast<int64_t>(Result) < (1LL << 32) &&
454 "overflow check failed for relocation");
456 // AArch64 code is emitted with .rela relocations. The data already in any
457 // bits affected by the relocation on entry is garbage.
458 *TargetPtr &= 0x9f00001fU;
459 // Immediate goes in bits 30:29 + 5:23 of ADRP instruction, taken
460 // from bits 32:12 of X.
461 *TargetPtr |= ((Result & 0x3000U) << (29 - 12));
462 *TargetPtr |= ((Result & 0x1ffffc000ULL) >> (14 - 5));
465 case ELF::R_AARCH64_LDST32_ABS_LO12_NC: {
467 uint64_t Result = Value + Addend;
469 // AArch64 code is emitted with .rela relocations. The data already in any
470 // bits affected by the relocation on entry is garbage.
471 *TargetPtr &= 0xffc003ffU;
472 // Immediate goes in bits 21:10 of LD/ST instruction, taken
473 // from bits 11:2 of X
474 *TargetPtr |= ((Result & 0xffc) << (10 - 2));
477 case ELF::R_AARCH64_LDST64_ABS_LO12_NC: {
479 uint64_t Result = Value + Addend;
481 // AArch64 code is emitted with .rela relocations. The data already in any
482 // bits affected by the relocation on entry is garbage.
483 *TargetPtr &= 0xffc003ffU;
484 // Immediate goes in bits 21:10 of LD/ST instruction, taken
485 // from bits 11:3 of X
486 *TargetPtr |= ((Result & 0xff8) << (10 - 3));
492 void RuntimeDyldELF::resolveARMRelocation(const SectionEntry &Section,
493 uint64_t Offset, uint32_t Value,
494 uint32_t Type, int32_t Addend) {
495 // TODO: Add Thumb relocations.
496 uint32_t *Placeholder =
497 reinterpret_cast<uint32_t *>(Section.ObjAddress + Offset);
498 uint32_t *TargetPtr = (uint32_t *)(Section.Address + Offset);
499 uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
502 DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: "
503 << Section.Address + Offset
504 << " FinalAddress: " << format("%p", FinalAddress) << " Value: "
505 << format("%x", Value) << " Type: " << format("%x", Type)
506 << " Addend: " << format("%x", Addend) << "\n");
510 llvm_unreachable("Not implemented relocation type!");
512 case ELF::R_ARM_NONE:
514 // Write a 32bit value to relocation address, taking into account the
515 // implicit addend encoded in the target.
516 case ELF::R_ARM_PREL31:
517 case ELF::R_ARM_TARGET1:
518 case ELF::R_ARM_ABS32:
519 *TargetPtr = *Placeholder + Value;
521 // Write first 16 bit of 32 bit value to the mov instruction.
522 // Last 4 bit should be shifted.
523 case ELF::R_ARM_MOVW_ABS_NC:
524 // We are not expecting any other addend in the relocation address.
525 // Using 0x000F0FFF because MOVW has its 16 bit immediate split into 2
526 // non-contiguous fields.
527 assert((*Placeholder & 0x000F0FFF) == 0);
528 Value = Value & 0xFFFF;
529 *TargetPtr = *Placeholder | (Value & 0xFFF);
530 *TargetPtr |= ((Value >> 12) & 0xF) << 16;
532 // Write last 16 bit of 32 bit value to the mov instruction.
533 // Last 4 bit should be shifted.
534 case ELF::R_ARM_MOVT_ABS:
535 // We are not expecting any other addend in the relocation address.
536 // Use 0x000F0FFF for the same reason as R_ARM_MOVW_ABS_NC.
537 assert((*Placeholder & 0x000F0FFF) == 0);
539 Value = (Value >> 16) & 0xFFFF;
540 *TargetPtr = *Placeholder | (Value & 0xFFF);
541 *TargetPtr |= ((Value >> 12) & 0xF) << 16;
543 // Write 24 bit relative value to the branch instruction.
544 case ELF::R_ARM_PC24: // Fall through.
545 case ELF::R_ARM_CALL: // Fall through.
546 case ELF::R_ARM_JUMP24: {
547 int32_t RelValue = static_cast<int32_t>(Value - FinalAddress - 8);
548 RelValue = (RelValue & 0x03FFFFFC) >> 2;
549 assert((*TargetPtr & 0xFFFFFF) == 0xFFFFFE);
550 *TargetPtr &= 0xFF000000;
551 *TargetPtr |= RelValue;
554 case ELF::R_ARM_PRIVATE_0:
555 // This relocation is reserved by the ARM ELF ABI for internal use. We
556 // appropriate it here to act as an R_ARM_ABS32 without any addend for use
557 // in the stubs created during JIT (which can't put an addend into the
558 // original object file).
564 void RuntimeDyldELF::resolveMIPSRelocation(const SectionEntry &Section,
565 uint64_t Offset, uint32_t Value,
566 uint32_t Type, int32_t Addend) {
567 uint32_t *Placeholder =
568 reinterpret_cast<uint32_t *>(Section.ObjAddress + Offset);
569 uint32_t *TargetPtr = (uint32_t *)(Section.Address + Offset);
572 DEBUG(dbgs() << "resolveMipselocation, LocalAddress: "
573 << Section.Address + Offset << " FinalAddress: "
574 << format("%p", Section.LoadAddress + Offset) << " Value: "
575 << format("%x", Value) << " Type: " << format("%x", Type)
576 << " Addend: " << format("%x", Addend) << "\n");
580 llvm_unreachable("Not implemented relocation type!");
583 *TargetPtr = Value + (*Placeholder);
586 *TargetPtr = ((*Placeholder) & 0xfc000000) | ((Value & 0x0fffffff) >> 2);
588 case ELF::R_MIPS_HI16:
589 // Get the higher 16-bits. Also add 1 if bit 15 is 1.
590 Value += ((*Placeholder) & 0x0000ffff) << 16;
592 ((*Placeholder) & 0xffff0000) | (((Value + 0x8000) >> 16) & 0xffff);
594 case ELF::R_MIPS_LO16:
595 Value += ((*Placeholder) & 0x0000ffff);
596 *TargetPtr = ((*Placeholder) & 0xffff0000) | (Value & 0xffff);
598 case ELF::R_MIPS_UNUSED1:
599 // Similar to ELF::R_ARM_PRIVATE_0, R_MIPS_UNUSED1 and R_MIPS_UNUSED2
600 // are used for internal JIT purpose. These relocations are similar to
601 // R_MIPS_HI16 and R_MIPS_LO16, but they do not take any addend into
604 ((*TargetPtr) & 0xffff0000) | (((Value + 0x8000) >> 16) & 0xffff);
606 case ELF::R_MIPS_UNUSED2:
607 *TargetPtr = ((*TargetPtr) & 0xffff0000) | (Value & 0xffff);
612 // Return the .TOC. section and offset.
613 void RuntimeDyldELF::findPPC64TOCSection(ObjectImage &Obj,
614 ObjSectionToIDMap &LocalSections,
615 RelocationValueRef &Rel) {
616 // Set a default SectionID in case we do not find a TOC section below.
617 // This may happen for references to TOC base base (sym@toc, .odp
618 // relocation) without a .toc directive. In this case just use the
619 // first section (which is usually the .odp) since the code won't
620 // reference the .toc base directly.
621 Rel.SymbolName = NULL;
624 // The TOC consists of sections .got, .toc, .tocbss, .plt in that
625 // order. The TOC starts where the first of these sections starts.
626 for (section_iterator si = Obj.begin_sections(), se = Obj.end_sections();
629 StringRef SectionName;
630 check(si->getName(SectionName));
632 if (SectionName == ".got"
633 || SectionName == ".toc"
634 || SectionName == ".tocbss"
635 || SectionName == ".plt") {
636 Rel.SectionID = findOrEmitSection(Obj, *si, false, LocalSections);
641 // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000
642 // thus permitting a full 64 Kbytes segment.
646 // Returns the sections and offset associated with the ODP entry referenced
648 void RuntimeDyldELF::findOPDEntrySection(ObjectImage &Obj,
649 ObjSectionToIDMap &LocalSections,
650 RelocationValueRef &Rel) {
651 // Get the ELF symbol value (st_value) to compare with Relocation offset in
653 for (section_iterator si = Obj.begin_sections(), se = Obj.end_sections();
655 section_iterator RelSecI = si->getRelocatedSection();
656 if (RelSecI == Obj.end_sections())
659 StringRef RelSectionName;
660 check(RelSecI->getName(RelSectionName));
661 if (RelSectionName != ".opd")
664 for (relocation_iterator i = si->relocation_begin(),
665 e = si->relocation_end();
667 // The R_PPC64_ADDR64 relocation indicates the first field
670 check(i->getType(TypeFunc));
671 if (TypeFunc != ELF::R_PPC64_ADDR64) {
676 uint64_t TargetSymbolOffset;
677 symbol_iterator TargetSymbol = i->getSymbol();
678 check(i->getOffset(TargetSymbolOffset));
680 check(getELFRelocationAddend(*i, Addend));
686 // Just check if following relocation is a R_PPC64_TOC
688 check(i->getType(TypeTOC));
689 if (TypeTOC != ELF::R_PPC64_TOC)
692 // Finally compares the Symbol value and the target symbol offset
693 // to check if this .opd entry refers to the symbol the relocation
695 if (Rel.Addend != (int64_t)TargetSymbolOffset)
698 section_iterator tsi(Obj.end_sections());
699 check(TargetSymbol->getSection(tsi));
702 Rel.SectionID = findOrEmitSection(Obj, (*tsi), IsCode, LocalSections);
703 Rel.Addend = (intptr_t)Addend;
707 llvm_unreachable("Attempting to get address of ODP entry!");
710 // Relocation masks following the #lo(value), #hi(value), #ha(value),
711 // #higher(value), #highera(value), #highest(value), and #highesta(value)
712 // macros defined in section 4.5.1. Relocation Types of the PPC-elf64abi
715 static inline uint16_t applyPPClo(uint64_t value) { return value & 0xffff; }
717 static inline uint16_t applyPPChi(uint64_t value) {
718 return (value >> 16) & 0xffff;
721 static inline uint16_t applyPPCha (uint64_t value) {
722 return ((value + 0x8000) >> 16) & 0xffff;
725 static inline uint16_t applyPPChigher(uint64_t value) {
726 return (value >> 32) & 0xffff;
729 static inline uint16_t applyPPChighera (uint64_t value) {
730 return ((value + 0x8000) >> 32) & 0xffff;
733 static inline uint16_t applyPPChighest(uint64_t value) {
734 return (value >> 48) & 0xffff;
737 static inline uint16_t applyPPChighesta (uint64_t value) {
738 return ((value + 0x8000) >> 48) & 0xffff;
741 void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section,
742 uint64_t Offset, uint64_t Value,
743 uint32_t Type, int64_t Addend) {
744 uint8_t *LocalAddress = Section.Address + Offset;
747 llvm_unreachable("Relocation type not implemented yet!");
749 case ELF::R_PPC64_ADDR16:
750 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
752 case ELF::R_PPC64_ADDR16_DS:
753 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
755 case ELF::R_PPC64_ADDR16_LO:
756 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
758 case ELF::R_PPC64_ADDR16_LO_DS:
759 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
761 case ELF::R_PPC64_ADDR16_HI:
762 writeInt16BE(LocalAddress, applyPPChi(Value + Addend));
764 case ELF::R_PPC64_ADDR16_HA:
765 writeInt16BE(LocalAddress, applyPPCha(Value + Addend));
767 case ELF::R_PPC64_ADDR16_HIGHER:
768 writeInt16BE(LocalAddress, applyPPChigher(Value + Addend));
770 case ELF::R_PPC64_ADDR16_HIGHERA:
771 writeInt16BE(LocalAddress, applyPPChighera(Value + Addend));
773 case ELF::R_PPC64_ADDR16_HIGHEST:
774 writeInt16BE(LocalAddress, applyPPChighest(Value + Addend));
776 case ELF::R_PPC64_ADDR16_HIGHESTA:
777 writeInt16BE(LocalAddress, applyPPChighesta(Value + Addend));
779 case ELF::R_PPC64_ADDR14: {
780 assert(((Value + Addend) & 3) == 0);
781 // Preserve the AA/LK bits in the branch instruction
782 uint8_t aalk = *(LocalAddress + 3);
783 writeInt16BE(LocalAddress + 2, (aalk & 3) | ((Value + Addend) & 0xfffc));
785 case ELF::R_PPC64_REL16_LO: {
786 uint64_t FinalAddress = (Section.LoadAddress + Offset);
787 uint64_t Delta = Value - FinalAddress + Addend;
788 writeInt16BE(LocalAddress, applyPPClo(Delta));
790 case ELF::R_PPC64_REL16_HI: {
791 uint64_t FinalAddress = (Section.LoadAddress + Offset);
792 uint64_t Delta = Value - FinalAddress + Addend;
793 writeInt16BE(LocalAddress, applyPPChi(Delta));
795 case ELF::R_PPC64_REL16_HA: {
796 uint64_t FinalAddress = (Section.LoadAddress + Offset);
797 uint64_t Delta = Value - FinalAddress + Addend;
798 writeInt16BE(LocalAddress, applyPPCha(Delta));
800 case ELF::R_PPC64_ADDR32: {
801 int32_t Result = static_cast<int32_t>(Value + Addend);
802 if (SignExtend32<32>(Result) != Result)
803 llvm_unreachable("Relocation R_PPC64_ADDR32 overflow");
804 writeInt32BE(LocalAddress, Result);
806 case ELF::R_PPC64_REL24: {
807 uint64_t FinalAddress = (Section.LoadAddress + Offset);
808 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
809 if (SignExtend32<24>(delta) != delta)
810 llvm_unreachable("Relocation R_PPC64_REL24 overflow");
811 // Generates a 'bl <address>' instruction
812 writeInt32BE(LocalAddress, 0x48000001 | (delta & 0x03FFFFFC));
814 case ELF::R_PPC64_REL32: {
815 uint64_t FinalAddress = (Section.LoadAddress + Offset);
816 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
817 if (SignExtend32<32>(delta) != delta)
818 llvm_unreachable("Relocation R_PPC64_REL32 overflow");
819 writeInt32BE(LocalAddress, delta);
821 case ELF::R_PPC64_REL64: {
822 uint64_t FinalAddress = (Section.LoadAddress + Offset);
823 uint64_t Delta = Value - FinalAddress + Addend;
824 writeInt64BE(LocalAddress, Delta);
826 case ELF::R_PPC64_ADDR64:
827 writeInt64BE(LocalAddress, Value + Addend);
832 void RuntimeDyldELF::resolveSystemZRelocation(const SectionEntry &Section,
833 uint64_t Offset, uint64_t Value,
834 uint32_t Type, int64_t Addend) {
835 uint8_t *LocalAddress = Section.Address + Offset;
838 llvm_unreachable("Relocation type not implemented yet!");
840 case ELF::R_390_PC16DBL:
841 case ELF::R_390_PLT16DBL: {
842 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
843 assert(int16_t(Delta / 2) * 2 == Delta && "R_390_PC16DBL overflow");
844 writeInt16BE(LocalAddress, Delta / 2);
847 case ELF::R_390_PC32DBL:
848 case ELF::R_390_PLT32DBL: {
849 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
850 assert(int32_t(Delta / 2) * 2 == Delta && "R_390_PC32DBL overflow");
851 writeInt32BE(LocalAddress, Delta / 2);
854 case ELF::R_390_PC32: {
855 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
856 assert(int32_t(Delta) == Delta && "R_390_PC32 overflow");
857 writeInt32BE(LocalAddress, Delta);
861 writeInt64BE(LocalAddress, Value + Addend);
866 // The target location for the relocation is described by RE.SectionID and
867 // RE.Offset. RE.SectionID can be used to find the SectionEntry. Each
868 // SectionEntry has three members describing its location.
869 // SectionEntry::Address is the address at which the section has been loaded
870 // into memory in the current (host) process. SectionEntry::LoadAddress is the
871 // address that the section will have in the target process.
872 // SectionEntry::ObjAddress is the address of the bits for this section in the
873 // original emitted object image (also in the current address space).
875 // Relocations will be applied as if the section were loaded at
876 // SectionEntry::LoadAddress, but they will be applied at an address based
877 // on SectionEntry::Address. SectionEntry::ObjAddress will be used to refer to
878 // Target memory contents if they are required for value calculations.
880 // The Value parameter here is the load address of the symbol for the
881 // relocation to be applied. For relocations which refer to symbols in the
882 // current object Value will be the LoadAddress of the section in which
883 // the symbol resides (RE.Addend provides additional information about the
884 // symbol location). For external symbols, Value will be the address of the
885 // symbol in the target address space.
886 void RuntimeDyldELF::resolveRelocation(const RelocationEntry &RE,
888 const SectionEntry &Section = Sections[RE.SectionID];
889 return resolveRelocation(Section, RE.Offset, Value, RE.RelType, RE.Addend,
893 void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section,
894 uint64_t Offset, uint64_t Value,
895 uint32_t Type, int64_t Addend,
896 uint64_t SymOffset) {
899 resolveX86_64Relocation(Section, Offset, Value, Type, Addend, SymOffset);
902 resolveX86Relocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
903 (uint32_t)(Addend & 0xffffffffL));
905 case Triple::aarch64:
906 case Triple::aarch64_be:
907 resolveAArch64Relocation(Section, Offset, Value, Type, Addend);
909 case Triple::arm: // Fall through.
912 case Triple::thumbeb:
913 resolveARMRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
914 (uint32_t)(Addend & 0xffffffffL));
916 case Triple::mips: // Fall through.
918 resolveMIPSRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL),
919 Type, (uint32_t)(Addend & 0xffffffffL));
921 case Triple::ppc64: // Fall through.
922 case Triple::ppc64le:
923 resolvePPC64Relocation(Section, Offset, Value, Type, Addend);
925 case Triple::systemz:
926 resolveSystemZRelocation(Section, Offset, Value, Type, Addend);
929 llvm_unreachable("Unsupported CPU type!");
933 relocation_iterator RuntimeDyldELF::processRelocationRef(
934 unsigned SectionID, relocation_iterator RelI, ObjectImage &Obj,
935 ObjSectionToIDMap &ObjSectionToID, const SymbolTableMap &Symbols,
938 Check(RelI->getType(RelType));
940 Check(getELFRelocationAddend(*RelI, Addend));
941 symbol_iterator Symbol = RelI->getSymbol();
943 // Obtain the symbol name which is referenced in the relocation
944 StringRef TargetName;
945 if (Symbol != Obj.end_symbols())
946 Symbol->getName(TargetName);
947 DEBUG(dbgs() << "\t\tRelType: " << RelType << " Addend: " << Addend
948 << " TargetName: " << TargetName << "\n");
949 RelocationValueRef Value;
950 // First search for the symbol in the local symbol table
951 SymbolTableMap::const_iterator lsi = Symbols.end();
952 SymbolRef::Type SymType = SymbolRef::ST_Unknown;
953 if (Symbol != Obj.end_symbols()) {
954 lsi = Symbols.find(TargetName.data());
955 Symbol->getType(SymType);
957 if (lsi != Symbols.end()) {
958 Value.SectionID = lsi->second.first;
959 Value.Offset = lsi->second.second;
960 Value.Addend = lsi->second.second + Addend;
962 // Search for the symbol in the global symbol table
963 SymbolTableMap::const_iterator gsi = GlobalSymbolTable.end();
964 if (Symbol != Obj.end_symbols())
965 gsi = GlobalSymbolTable.find(TargetName.data());
966 if (gsi != GlobalSymbolTable.end()) {
967 Value.SectionID = gsi->second.first;
968 Value.Offset = gsi->second.second;
969 Value.Addend = gsi->second.second + Addend;
972 case SymbolRef::ST_Debug: {
973 // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously
974 // and can be changed by another developers. Maybe best way is add
975 // a new symbol type ST_Section to SymbolRef and use it.
976 section_iterator si(Obj.end_sections());
977 Symbol->getSection(si);
978 if (si == Obj.end_sections())
979 llvm_unreachable("Symbol section not found, bad object file format!");
980 DEBUG(dbgs() << "\t\tThis is section symbol\n");
981 // Default to 'true' in case isText fails (though it never does).
984 Value.SectionID = findOrEmitSection(Obj, (*si), isCode, ObjSectionToID);
985 Value.Addend = Addend;
988 case SymbolRef::ST_Data:
989 case SymbolRef::ST_Unknown: {
990 Value.SymbolName = TargetName.data();
991 Value.Addend = Addend;
993 // Absolute relocations will have a zero symbol ID (STN_UNDEF), which
994 // will manifest here as a NULL symbol name.
995 // We can set this as a valid (but empty) symbol name, and rely
996 // on addRelocationForSymbol to handle this.
997 if (!Value.SymbolName)
998 Value.SymbolName = "";
1002 llvm_unreachable("Unresolved symbol type!");
1008 Check(RelI->getOffset(Offset));
1010 DEBUG(dbgs() << "\t\tSectionID: " << SectionID << " Offset: " << Offset
1012 if ((Arch == Triple::aarch64 || Arch == Triple::aarch64_be) &&
1013 (RelType == ELF::R_AARCH64_CALL26 || RelType == ELF::R_AARCH64_JUMP26)) {
1014 // This is an AArch64 branch relocation, need to use a stub function.
1015 DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation.");
1016 SectionEntry &Section = Sections[SectionID];
1018 // Look for an existing stub.
1019 StubMap::const_iterator i = Stubs.find(Value);
1020 if (i != Stubs.end()) {
1021 resolveRelocation(Section, Offset, (uint64_t)Section.Address + i->second,
1023 DEBUG(dbgs() << " Stub function found\n");
1025 // Create a new stub function.
1026 DEBUG(dbgs() << " Create a new stub function\n");
1027 Stubs[Value] = Section.StubOffset;
1028 uint8_t *StubTargetAddr =
1029 createStubFunction(Section.Address + Section.StubOffset);
1031 RelocationEntry REmovz_g3(SectionID, StubTargetAddr - Section.Address,
1032 ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend);
1033 RelocationEntry REmovk_g2(SectionID, StubTargetAddr - Section.Address + 4,
1034 ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend);
1035 RelocationEntry REmovk_g1(SectionID, StubTargetAddr - Section.Address + 8,
1036 ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend);
1037 RelocationEntry REmovk_g0(SectionID,
1038 StubTargetAddr - Section.Address + 12,
1039 ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend);
1041 if (Value.SymbolName) {
1042 addRelocationForSymbol(REmovz_g3, Value.SymbolName);
1043 addRelocationForSymbol(REmovk_g2, Value.SymbolName);
1044 addRelocationForSymbol(REmovk_g1, Value.SymbolName);
1045 addRelocationForSymbol(REmovk_g0, Value.SymbolName);
1047 addRelocationForSection(REmovz_g3, Value.SectionID);
1048 addRelocationForSection(REmovk_g2, Value.SectionID);
1049 addRelocationForSection(REmovk_g1, Value.SectionID);
1050 addRelocationForSection(REmovk_g0, Value.SectionID);
1052 resolveRelocation(Section, Offset,
1053 (uint64_t)Section.Address + Section.StubOffset, RelType,
1055 Section.StubOffset += getMaxStubSize();
1057 } else if (Arch == Triple::arm &&
1058 (RelType == ELF::R_ARM_PC24 || RelType == ELF::R_ARM_CALL ||
1059 RelType == ELF::R_ARM_JUMP24)) {
1060 // This is an ARM branch relocation, need to use a stub function.
1061 DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.");
1062 SectionEntry &Section = Sections[SectionID];
1064 // Look for an existing stub.
1065 StubMap::const_iterator i = Stubs.find(Value);
1066 if (i != Stubs.end()) {
1067 resolveRelocation(Section, Offset, (uint64_t)Section.Address + i->second,
1069 DEBUG(dbgs() << " Stub function found\n");
1071 // Create a new stub function.
1072 DEBUG(dbgs() << " Create a new stub function\n");
1073 Stubs[Value] = Section.StubOffset;
1074 uint8_t *StubTargetAddr =
1075 createStubFunction(Section.Address + Section.StubOffset);
1076 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1077 ELF::R_ARM_PRIVATE_0, Value.Addend);
1078 if (Value.SymbolName)
1079 addRelocationForSymbol(RE, Value.SymbolName);
1081 addRelocationForSection(RE, Value.SectionID);
1083 resolveRelocation(Section, Offset,
1084 (uint64_t)Section.Address + Section.StubOffset, RelType,
1086 Section.StubOffset += getMaxStubSize();
1088 } else if ((Arch == Triple::mipsel || Arch == Triple::mips) &&
1089 RelType == ELF::R_MIPS_26) {
1090 // This is an Mips branch relocation, need to use a stub function.
1091 DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
1092 SectionEntry &Section = Sections[SectionID];
1093 uint8_t *Target = Section.Address + Offset;
1094 uint32_t *TargetAddress = (uint32_t *)Target;
1096 // Extract the addend from the instruction.
1097 uint32_t Addend = ((*TargetAddress) & 0x03ffffff) << 2;
1099 Value.Addend += Addend;
1101 // Look up for existing stub.
1102 StubMap::const_iterator i = Stubs.find(Value);
1103 if (i != Stubs.end()) {
1104 RelocationEntry RE(SectionID, Offset, RelType, i->second);
1105 addRelocationForSection(RE, SectionID);
1106 DEBUG(dbgs() << " Stub function found\n");
1108 // Create a new stub function.
1109 DEBUG(dbgs() << " Create a new stub function\n");
1110 Stubs[Value] = Section.StubOffset;
1111 uint8_t *StubTargetAddr =
1112 createStubFunction(Section.Address + Section.StubOffset);
1114 // Creating Hi and Lo relocations for the filled stub instructions.
1115 RelocationEntry REHi(SectionID, StubTargetAddr - Section.Address,
1116 ELF::R_MIPS_UNUSED1, Value.Addend);
1117 RelocationEntry RELo(SectionID, StubTargetAddr - Section.Address + 4,
1118 ELF::R_MIPS_UNUSED2, Value.Addend);
1120 if (Value.SymbolName) {
1121 addRelocationForSymbol(REHi, Value.SymbolName);
1122 addRelocationForSymbol(RELo, Value.SymbolName);
1124 addRelocationForSection(REHi, Value.SectionID);
1125 addRelocationForSection(RELo, Value.SectionID);
1128 RelocationEntry RE(SectionID, Offset, RelType, Section.StubOffset);
1129 addRelocationForSection(RE, SectionID);
1130 Section.StubOffset += getMaxStubSize();
1132 } else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) {
1133 if (RelType == ELF::R_PPC64_REL24) {
1134 // Determine ABI variant in use for this object.
1135 unsigned AbiVariant;
1136 Obj.getObjectFile()->getPlatformFlags(AbiVariant);
1137 AbiVariant &= ELF::EF_PPC64_ABI;
1138 // A PPC branch relocation will need a stub function if the target is
1139 // an external symbol (Symbol::ST_Unknown) or if the target address
1140 // is not within the signed 24-bits branch address.
1141 SectionEntry &Section = Sections[SectionID];
1142 uint8_t *Target = Section.Address + Offset;
1143 bool RangeOverflow = false;
1144 if (SymType != SymbolRef::ST_Unknown) {
1145 if (AbiVariant != 2) {
1146 // In the ELFv1 ABI, a function call may point to the .opd entry,
1147 // so the final symbol value is calculated based on the relocation
1148 // values in the .opd section.
1149 findOPDEntrySection(Obj, ObjSectionToID, Value);
1151 // In the ELFv2 ABI, a function symbol may provide a local entry
1152 // point, which must be used for direct calls.
1154 Symbol->getOther(SymOther);
1155 Value.Addend += ELF::decodePPC64LocalEntryOffset(SymOther);
1157 uint8_t *RelocTarget = Sections[Value.SectionID].Address + Value.Addend;
1158 int32_t delta = static_cast<int32_t>(Target - RelocTarget);
1159 // If it is within 24-bits branch range, just set the branch target
1160 if (SignExtend32<24>(delta) == delta) {
1161 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1162 if (Value.SymbolName)
1163 addRelocationForSymbol(RE, Value.SymbolName);
1165 addRelocationForSection(RE, Value.SectionID);
1167 RangeOverflow = true;
1170 if (SymType == SymbolRef::ST_Unknown || RangeOverflow == true) {
1171 // It is an external symbol (SymbolRef::ST_Unknown) or within a range
1172 // larger than 24-bits.
1173 StubMap::const_iterator i = Stubs.find(Value);
1174 if (i != Stubs.end()) {
1175 // Symbol function stub already created, just relocate to it
1176 resolveRelocation(Section, Offset,
1177 (uint64_t)Section.Address + i->second, RelType, 0);
1178 DEBUG(dbgs() << " Stub function found\n");
1180 // Create a new stub function.
1181 DEBUG(dbgs() << " Create a new stub function\n");
1182 Stubs[Value] = Section.StubOffset;
1183 uint8_t *StubTargetAddr =
1184 createStubFunction(Section.Address + Section.StubOffset,
1186 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1187 ELF::R_PPC64_ADDR64, Value.Addend);
1189 // Generates the 64-bits address loads as exemplified in section
1190 // 4.5.1 in PPC64 ELF ABI. Note that the relocations need to
1191 // apply to the low part of the instructions, so we have to update
1192 // the offset according to the target endianness.
1193 uint64_t StubRelocOffset = StubTargetAddr - Section.Address;
1194 if (!IsTargetLittleEndian)
1195 StubRelocOffset += 2;
1197 RelocationEntry REhst(SectionID, StubRelocOffset + 0,
1198 ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend);
1199 RelocationEntry REhr(SectionID, StubRelocOffset + 4,
1200 ELF::R_PPC64_ADDR16_HIGHER, Value.Addend);
1201 RelocationEntry REh(SectionID, StubRelocOffset + 12,
1202 ELF::R_PPC64_ADDR16_HI, Value.Addend);
1203 RelocationEntry REl(SectionID, StubRelocOffset + 16,
1204 ELF::R_PPC64_ADDR16_LO, Value.Addend);
1206 if (Value.SymbolName) {
1207 addRelocationForSymbol(REhst, Value.SymbolName);
1208 addRelocationForSymbol(REhr, Value.SymbolName);
1209 addRelocationForSymbol(REh, Value.SymbolName);
1210 addRelocationForSymbol(REl, Value.SymbolName);
1212 addRelocationForSection(REhst, Value.SectionID);
1213 addRelocationForSection(REhr, Value.SectionID);
1214 addRelocationForSection(REh, Value.SectionID);
1215 addRelocationForSection(REl, Value.SectionID);
1218 resolveRelocation(Section, Offset,
1219 (uint64_t)Section.Address + Section.StubOffset,
1221 Section.StubOffset += getMaxStubSize();
1223 if (SymType == SymbolRef::ST_Unknown) {
1224 // Restore the TOC for external calls
1225 if (AbiVariant == 2)
1226 writeInt32BE(Target + 4, 0xE8410018); // ld r2,28(r1)
1228 writeInt32BE(Target + 4, 0xE8410028); // ld r2,40(r1)
1231 } else if (RelType == ELF::R_PPC64_TOC16 ||
1232 RelType == ELF::R_PPC64_TOC16_DS ||
1233 RelType == ELF::R_PPC64_TOC16_LO ||
1234 RelType == ELF::R_PPC64_TOC16_LO_DS ||
1235 RelType == ELF::R_PPC64_TOC16_HI ||
1236 RelType == ELF::R_PPC64_TOC16_HA) {
1237 // These relocations are supposed to subtract the TOC address from
1238 // the final value. This does not fit cleanly into the RuntimeDyld
1239 // scheme, since there may be *two* sections involved in determining
1240 // the relocation value (the section of the symbol refered to by the
1241 // relocation, and the TOC section associated with the current module).
1243 // Fortunately, these relocations are currently only ever generated
1244 // refering to symbols that themselves reside in the TOC, which means
1245 // that the two sections are actually the same. Thus they cancel out
1246 // and we can immediately resolve the relocation right now.
1248 case ELF::R_PPC64_TOC16: RelType = ELF::R_PPC64_ADDR16; break;
1249 case ELF::R_PPC64_TOC16_DS: RelType = ELF::R_PPC64_ADDR16_DS; break;
1250 case ELF::R_PPC64_TOC16_LO: RelType = ELF::R_PPC64_ADDR16_LO; break;
1251 case ELF::R_PPC64_TOC16_LO_DS: RelType = ELF::R_PPC64_ADDR16_LO_DS; break;
1252 case ELF::R_PPC64_TOC16_HI: RelType = ELF::R_PPC64_ADDR16_HI; break;
1253 case ELF::R_PPC64_TOC16_HA: RelType = ELF::R_PPC64_ADDR16_HA; break;
1254 default: llvm_unreachable("Wrong relocation type.");
1257 RelocationValueRef TOCValue;
1258 findPPC64TOCSection(Obj, ObjSectionToID, TOCValue);
1259 if (Value.SymbolName || Value.SectionID != TOCValue.SectionID)
1260 llvm_unreachable("Unsupported TOC relocation.");
1261 Value.Addend -= TOCValue.Addend;
1262 resolveRelocation(Sections[SectionID], Offset, Value.Addend, RelType, 0);
1264 // There are two ways to refer to the TOC address directly: either
1265 // via a ELF::R_PPC64_TOC relocation (where both symbol and addend are
1266 // ignored), or via any relocation that refers to the magic ".TOC."
1267 // symbols (in which case the addend is respected).
1268 if (RelType == ELF::R_PPC64_TOC) {
1269 RelType = ELF::R_PPC64_ADDR64;
1270 findPPC64TOCSection(Obj, ObjSectionToID, Value);
1271 } else if (TargetName == ".TOC.") {
1272 findPPC64TOCSection(Obj, ObjSectionToID, Value);
1273 Value.Addend += Addend;
1276 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1278 if (Value.SymbolName)
1279 addRelocationForSymbol(RE, Value.SymbolName);
1281 addRelocationForSection(RE, Value.SectionID);
1283 } else if (Arch == Triple::systemz &&
1284 (RelType == ELF::R_390_PLT32DBL || RelType == ELF::R_390_GOTENT)) {
1285 // Create function stubs for both PLT and GOT references, regardless of
1286 // whether the GOT reference is to data or code. The stub contains the
1287 // full address of the symbol, as needed by GOT references, and the
1288 // executable part only adds an overhead of 8 bytes.
1290 // We could try to conserve space by allocating the code and data
1291 // parts of the stub separately. However, as things stand, we allocate
1292 // a stub for every relocation, so using a GOT in JIT code should be
1293 // no less space efficient than using an explicit constant pool.
1294 DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation.");
1295 SectionEntry &Section = Sections[SectionID];
1297 // Look for an existing stub.
1298 StubMap::const_iterator i = Stubs.find(Value);
1299 uintptr_t StubAddress;
1300 if (i != Stubs.end()) {
1301 StubAddress = uintptr_t(Section.Address) + i->second;
1302 DEBUG(dbgs() << " Stub function found\n");
1304 // Create a new stub function.
1305 DEBUG(dbgs() << " Create a new stub function\n");
1307 uintptr_t BaseAddress = uintptr_t(Section.Address);
1308 uintptr_t StubAlignment = getStubAlignment();
1309 StubAddress = (BaseAddress + Section.StubOffset + StubAlignment - 1) &
1311 unsigned StubOffset = StubAddress - BaseAddress;
1313 Stubs[Value] = StubOffset;
1314 createStubFunction((uint8_t *)StubAddress);
1315 RelocationEntry RE(SectionID, StubOffset + 8, ELF::R_390_64,
1317 if (Value.SymbolName)
1318 addRelocationForSymbol(RE, Value.SymbolName);
1320 addRelocationForSection(RE, Value.SectionID);
1321 Section.StubOffset = StubOffset + getMaxStubSize();
1324 if (RelType == ELF::R_390_GOTENT)
1325 resolveRelocation(Section, Offset, StubAddress + 8, ELF::R_390_PC32DBL,
1328 resolveRelocation(Section, Offset, StubAddress, RelType, Addend);
1329 } else if (Arch == Triple::x86_64 && RelType == ELF::R_X86_64_PLT32) {
1330 // The way the PLT relocations normally work is that the linker allocates
1332 // PLT and this relocation makes a PC-relative call into the PLT. The PLT
1333 // entry will then jump to an address provided by the GOT. On first call,
1335 // GOT address will point back into PLT code that resolves the symbol. After
1336 // the first call, the GOT entry points to the actual function.
1338 // For local functions we're ignoring all of that here and just replacing
1339 // the PLT32 relocation type with PC32, which will translate the relocation
1340 // into a PC-relative call directly to the function. For external symbols we
1341 // can't be sure the function will be within 2^32 bytes of the call site, so
1342 // we need to create a stub, which calls into the GOT. This case is
1343 // equivalent to the usual PLT implementation except that we use the stub
1344 // mechanism in RuntimeDyld (which puts stubs at the end of the section)
1345 // rather than allocating a PLT section.
1346 if (Value.SymbolName) {
1347 // This is a call to an external function.
1348 // Look for an existing stub.
1349 SectionEntry &Section = Sections[SectionID];
1350 StubMap::const_iterator i = Stubs.find(Value);
1351 uintptr_t StubAddress;
1352 if (i != Stubs.end()) {
1353 StubAddress = uintptr_t(Section.Address) + i->second;
1354 DEBUG(dbgs() << " Stub function found\n");
1356 // Create a new stub function (equivalent to a PLT entry).
1357 DEBUG(dbgs() << " Create a new stub function\n");
1359 uintptr_t BaseAddress = uintptr_t(Section.Address);
1360 uintptr_t StubAlignment = getStubAlignment();
1361 StubAddress = (BaseAddress + Section.StubOffset + StubAlignment - 1) &
1363 unsigned StubOffset = StubAddress - BaseAddress;
1364 Stubs[Value] = StubOffset;
1365 createStubFunction((uint8_t *)StubAddress);
1367 // Create a GOT entry for the external function.
1368 GOTEntries.push_back(Value);
1370 // Make our stub function a relative call to the GOT entry.
1371 RelocationEntry RE(SectionID, StubOffset + 2, ELF::R_X86_64_GOTPCREL,
1373 addRelocationForSymbol(RE, Value.SymbolName);
1375 // Bump our stub offset counter
1376 Section.StubOffset = StubOffset + getMaxStubSize();
1379 // Make the target call a call into the stub table.
1380 resolveRelocation(Section, Offset, StubAddress, ELF::R_X86_64_PC32,
1383 RelocationEntry RE(SectionID, Offset, ELF::R_X86_64_PC32, Value.Addend,
1385 addRelocationForSection(RE, Value.SectionID);
1388 if (Arch == Triple::x86_64 && RelType == ELF::R_X86_64_GOTPCREL) {
1389 GOTEntries.push_back(Value);
1391 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend, Value.Offset);
1392 if (Value.SymbolName)
1393 addRelocationForSymbol(RE, Value.SymbolName);
1395 addRelocationForSection(RE, Value.SectionID);
1400 void RuntimeDyldELF::updateGOTEntries(StringRef Name, uint64_t Addr) {
1402 SmallVectorImpl<std::pair<SID, GOTRelocations>>::iterator it;
1403 SmallVectorImpl<std::pair<SID, GOTRelocations>>::iterator end = GOTs.end();
1405 for (it = GOTs.begin(); it != end; ++it) {
1406 GOTRelocations &GOTEntries = it->second;
1407 for (int i = 0, e = GOTEntries.size(); i != e; ++i) {
1408 if (GOTEntries[i].SymbolName != nullptr &&
1409 GOTEntries[i].SymbolName == Name) {
1410 GOTEntries[i].Offset = Addr;
1416 size_t RuntimeDyldELF::getGOTEntrySize() {
1417 // We don't use the GOT in all of these cases, but it's essentially free
1418 // to put them all here.
1421 case Triple::x86_64:
1422 case Triple::aarch64:
1423 case Triple::aarch64_be:
1425 case Triple::ppc64le:
1426 case Triple::systemz:
1427 Result = sizeof(uint64_t);
1433 case Triple::mipsel:
1434 Result = sizeof(uint32_t);
1437 llvm_unreachable("Unsupported CPU type!");
1442 uint64_t RuntimeDyldELF::findGOTEntry(uint64_t LoadAddress, uint64_t Offset) {
1444 const size_t GOTEntrySize = getGOTEntrySize();
1446 SmallVectorImpl<std::pair<SID, GOTRelocations>>::const_iterator it;
1447 SmallVectorImpl<std::pair<SID, GOTRelocations>>::const_iterator end =
1451 for (it = GOTs.begin(); it != end; ++it) {
1452 SID GOTSectionID = it->first;
1453 const GOTRelocations &GOTEntries = it->second;
1455 // Find the matching entry in our vector.
1456 uint64_t SymbolOffset = 0;
1457 for (int i = 0, e = GOTEntries.size(); i != e; ++i) {
1458 if (!GOTEntries[i].SymbolName) {
1459 if (getSectionLoadAddress(GOTEntries[i].SectionID) == LoadAddress &&
1460 GOTEntries[i].Offset == Offset) {
1462 SymbolOffset = GOTEntries[i].Offset;
1466 // GOT entries for external symbols use the addend as the address when
1467 // the external symbol has been resolved.
1468 if (GOTEntries[i].Offset == LoadAddress) {
1470 // Don't use the Addend here. The relocation handler will use it.
1476 if (GOTIndex != -1) {
1477 if (GOTEntrySize == sizeof(uint64_t)) {
1478 uint64_t *LocalGOTAddr = (uint64_t *)getSectionAddress(GOTSectionID);
1479 // Fill in this entry with the address of the symbol being referenced.
1480 LocalGOTAddr[GOTIndex] = LoadAddress + SymbolOffset;
1482 uint32_t *LocalGOTAddr = (uint32_t *)getSectionAddress(GOTSectionID);
1483 // Fill in this entry with the address of the symbol being referenced.
1484 LocalGOTAddr[GOTIndex] = (uint32_t)(LoadAddress + SymbolOffset);
1487 // Calculate the load address of this entry
1488 return getSectionLoadAddress(GOTSectionID) + (GOTIndex * GOTEntrySize);
1492 assert(GOTIndex != -1 && "Unable to find requested GOT entry.");
1496 void RuntimeDyldELF::finalizeLoad(ObjectImage &ObjImg,
1497 ObjSectionToIDMap &SectionMap) {
1498 // If necessary, allocate the global offset table
1500 // Allocate the GOT if necessary
1501 size_t numGOTEntries = GOTEntries.size();
1502 if (numGOTEntries != 0) {
1503 // Allocate memory for the section
1504 unsigned SectionID = Sections.size();
1505 size_t TotalSize = numGOTEntries * getGOTEntrySize();
1506 uint8_t *Addr = MemMgr->allocateDataSection(TotalSize, getGOTEntrySize(),
1507 SectionID, ".got", false);
1509 report_fatal_error("Unable to allocate memory for GOT!");
1511 GOTs.push_back(std::make_pair(SectionID, GOTEntries));
1512 Sections.push_back(SectionEntry(".got", Addr, TotalSize, 0));
1513 // For now, initialize all GOT entries to zero. We'll fill them in as
1514 // needed when GOT-based relocations are applied.
1515 memset(Addr, 0, TotalSize);
1518 report_fatal_error("Unable to allocate memory for GOT!");
1521 // Look for and record the EH frame section.
1522 ObjSectionToIDMap::iterator i, e;
1523 for (i = SectionMap.begin(), e = SectionMap.end(); i != e; ++i) {
1524 const SectionRef &Section = i->first;
1526 Section.getName(Name);
1527 if (Name == ".eh_frame") {
1528 UnregisteredEHFrameSections.push_back(i->second);
1534 bool RuntimeDyldELF::isCompatibleFormat(const ObjectBuffer *Buffer) const {
1535 if (Buffer->getBufferSize() < strlen(ELF::ElfMagic))
1537 return (memcmp(Buffer->getBufferStart(), ELF::ElfMagic,
1538 strlen(ELF::ElfMagic))) == 0;
1541 bool RuntimeDyldELF::isCompatibleFile(const object::ObjectFile *Obj) const {
1542 return Obj->isELF();