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/MemoryBuffer.h"
29 using namespace llvm::object;
30 using std::error_code;
32 #define DEBUG_TYPE "dyld"
36 static inline error_code check(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 MemoryBuffer *Wrapper, error_code &ec);
61 DyldELFObject(MemoryBuffer *Wrapper, 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(MemoryBuffer *Wrapper, 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 MemoryBuffer *Wrapper, 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 MemoryBuffer *Buffer =
188 MemoryBuffer::getMemBuffer(ObjFile->getData(), "", false);
190 if (ObjFile->getBytesInAddress() == 4 && ObjFile->isLittleEndian()) {
192 llvm::make_unique<DyldELFObject<ELFType<support::little, 2, false>>>(
193 std::move(ObjFile), Buffer, ec);
194 return new ELFObjectImage<ELFType<support::little, 2, false>>(
195 nullptr, std::move(Obj));
196 } else if (ObjFile->getBytesInAddress() == 4 && !ObjFile->isLittleEndian()) {
198 llvm::make_unique<DyldELFObject<ELFType<support::big, 2, false>>>(
199 std::move(ObjFile), Buffer, ec);
200 return new ELFObjectImage<ELFType<support::big, 2, false>>(nullptr, std::move(Obj));
201 } else if (ObjFile->getBytesInAddress() == 8 && !ObjFile->isLittleEndian()) {
202 auto Obj = llvm::make_unique<DyldELFObject<ELFType<support::big, 2, true>>>(
203 std::move(ObjFile), Buffer, ec);
204 return new ELFObjectImage<ELFType<support::big, 2, true>>(nullptr,
206 } else if (ObjFile->getBytesInAddress() == 8 && ObjFile->isLittleEndian()) {
208 llvm::make_unique<DyldELFObject<ELFType<support::little, 2, true>>>(
209 std::move(ObjFile), Buffer, ec);
210 return new ELFObjectImage<ELFType<support::little, 2, true>>(
211 nullptr, std::move(Obj));
213 llvm_unreachable("Unexpected ELF format");
216 ObjectImage *RuntimeDyldELF::createObjectImage(ObjectBuffer *Buffer) {
217 if (Buffer->getBufferSize() < ELF::EI_NIDENT)
218 llvm_unreachable("Unexpected ELF object size");
219 std::pair<unsigned char, unsigned char> Ident =
220 std::make_pair((uint8_t)Buffer->getBufferStart()[ELF::EI_CLASS],
221 (uint8_t)Buffer->getBufferStart()[ELF::EI_DATA]);
224 if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2LSB) {
226 llvm::make_unique<DyldELFObject<ELFType<support::little, 4, false>>>(
227 Buffer->getMemBuffer(), ec);
228 return new ELFObjectImage<ELFType<support::little, 4, false>>(
229 Buffer, std::move(Obj));
230 } else if (Ident.first == ELF::ELFCLASS32 &&
231 Ident.second == ELF::ELFDATA2MSB) {
233 llvm::make_unique<DyldELFObject<ELFType<support::big, 4, false>>>(
234 Buffer->getMemBuffer(), ec);
235 return new ELFObjectImage<ELFType<support::big, 4, false>>(Buffer,
237 } else if (Ident.first == ELF::ELFCLASS64 &&
238 Ident.second == ELF::ELFDATA2MSB) {
239 auto Obj = llvm::make_unique<DyldELFObject<ELFType<support::big, 8, true>>>(
240 Buffer->getMemBuffer(), ec);
241 return new ELFObjectImage<ELFType<support::big, 8, true>>(Buffer, std::move(Obj));
242 } else if (Ident.first == ELF::ELFCLASS64 &&
243 Ident.second == ELF::ELFDATA2LSB) {
245 llvm::make_unique<DyldELFObject<ELFType<support::little, 8, true>>>(
246 Buffer->getMemBuffer(), ec);
247 return new ELFObjectImage<ELFType<support::little, 8, true>>(Buffer, std::move(Obj));
249 llvm_unreachable("Unexpected ELF format");
252 RuntimeDyldELF::~RuntimeDyldELF() {}
254 void RuntimeDyldELF::resolveX86_64Relocation(const SectionEntry &Section,
255 uint64_t Offset, uint64_t Value,
256 uint32_t Type, int64_t Addend,
257 uint64_t SymOffset) {
260 llvm_unreachable("Relocation type not implemented yet!");
262 case ELF::R_X86_64_64: {
263 uint64_t *Target = reinterpret_cast<uint64_t *>(Section.Address + Offset);
264 *Target = Value + Addend;
265 DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend)) << " at "
266 << format("%p\n", Target));
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 uint32_t *Target = reinterpret_cast<uint32_t *>(Section.Address + Offset);
277 *Target = TruncatedAddr;
278 DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr) << " at "
279 << format("%p\n", Target));
282 case ELF::R_X86_64_GOTPCREL: {
283 // findGOTEntry returns the 'G + GOT' part of the relocation calculation
284 // based on the load/target address of the GOT (not the current/local addr).
285 uint64_t GOTAddr = findGOTEntry(Value, SymOffset);
286 uint32_t *Target = reinterpret_cast<uint32_t *>(Section.Address + Offset);
287 uint64_t FinalAddress = Section.LoadAddress + Offset;
288 // The processRelocationRef method combines the symbol offset and the addend
289 // and in most cases that's what we want. For this relocation type, we need
290 // the raw addend, so we subtract the symbol offset to get it.
291 int64_t RealOffset = GOTAddr + Addend - SymOffset - FinalAddress;
292 assert(RealOffset <= INT32_MAX && RealOffset >= INT32_MIN);
293 int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
294 *Target = TruncOffset;
297 case ELF::R_X86_64_PC32: {
298 // Get the placeholder value from the generated object since
299 // a previous relocation attempt may have overwritten the loaded version
300 uint32_t *Placeholder =
301 reinterpret_cast<uint32_t *>(Section.ObjAddress + Offset);
302 uint32_t *Target = reinterpret_cast<uint32_t *>(Section.Address + Offset);
303 uint64_t FinalAddress = Section.LoadAddress + Offset;
304 int64_t RealOffset = *Placeholder + Value + Addend - FinalAddress;
305 assert(RealOffset <= INT32_MAX && RealOffset >= INT32_MIN);
306 int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
307 *Target = TruncOffset;
310 case ELF::R_X86_64_PC64: {
311 // Get the placeholder value from the generated object since
312 // a previous relocation attempt may have overwritten the loaded version
313 uint64_t *Placeholder =
314 reinterpret_cast<uint64_t *>(Section.ObjAddress + Offset);
315 uint64_t *Target = reinterpret_cast<uint64_t *>(Section.Address + Offset);
316 uint64_t FinalAddress = Section.LoadAddress + Offset;
317 *Target = *Placeholder + Value + Addend - FinalAddress;
323 void RuntimeDyldELF::resolveX86Relocation(const SectionEntry &Section,
324 uint64_t Offset, uint32_t Value,
325 uint32_t Type, int32_t Addend) {
327 case ELF::R_386_32: {
328 // Get the placeholder value from the generated object since
329 // a previous relocation attempt may have overwritten the loaded version
330 uint32_t *Placeholder =
331 reinterpret_cast<uint32_t *>(Section.ObjAddress + Offset);
332 uint32_t *Target = reinterpret_cast<uint32_t *>(Section.Address + Offset);
333 *Target = *Placeholder + Value + Addend;
336 case ELF::R_386_PC32: {
337 // Get the placeholder value from the generated object since
338 // a previous relocation attempt may have overwritten the loaded version
339 uint32_t *Placeholder =
340 reinterpret_cast<uint32_t *>(Section.ObjAddress + Offset);
341 uint32_t *Target = reinterpret_cast<uint32_t *>(Section.Address + Offset);
342 uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
343 uint32_t RealOffset = *Placeholder + Value + Addend - FinalAddress;
344 *Target = RealOffset;
348 // There are other relocation types, but it appears these are the
349 // only ones currently used by the LLVM ELF object writer
350 llvm_unreachable("Relocation type not implemented yet!");
355 void RuntimeDyldELF::resolveAArch64Relocation(const SectionEntry &Section,
356 uint64_t Offset, uint64_t Value,
357 uint32_t Type, int64_t Addend) {
358 uint32_t *TargetPtr = reinterpret_cast<uint32_t *>(Section.Address + Offset);
359 uint64_t FinalAddress = Section.LoadAddress + Offset;
361 DEBUG(dbgs() << "resolveAArch64Relocation, LocalAddress: 0x"
362 << format("%llx", Section.Address + Offset)
363 << " FinalAddress: 0x" << format("%llx", FinalAddress)
364 << " Value: 0x" << format("%llx", Value) << " Type: 0x"
365 << format("%x", Type) << " Addend: 0x" << format("%llx", Addend)
370 llvm_unreachable("Relocation type not implemented yet!");
372 case ELF::R_AARCH64_ABS64: {
373 uint64_t *TargetPtr =
374 reinterpret_cast<uint64_t *>(Section.Address + Offset);
375 *TargetPtr = Value + Addend;
378 case ELF::R_AARCH64_PREL32: {
379 uint64_t Result = Value + Addend - FinalAddress;
380 assert(static_cast<int64_t>(Result) >= INT32_MIN &&
381 static_cast<int64_t>(Result) <= UINT32_MAX);
382 *TargetPtr = static_cast<uint32_t>(Result & 0xffffffffU);
385 case ELF::R_AARCH64_CALL26: // fallthrough
386 case ELF::R_AARCH64_JUMP26: {
387 // Operation: S+A-P. Set Call or B immediate value to bits fff_fffc of the
389 uint64_t BranchImm = Value + Addend - FinalAddress;
391 // "Check that -2^27 <= result < 2^27".
392 assert(-(1LL << 27) <= static_cast<int64_t>(BranchImm) &&
393 static_cast<int64_t>(BranchImm) < (1LL << 27));
395 // AArch64 code is emitted with .rela relocations. The data already in any
396 // bits affected by the relocation on entry is garbage.
397 *TargetPtr &= 0xfc000000U;
398 // Immediate goes in bits 25:0 of B and BL.
399 *TargetPtr |= static_cast<uint32_t>(BranchImm & 0xffffffcU) >> 2;
402 case ELF::R_AARCH64_MOVW_UABS_G3: {
403 uint64_t Result = Value + Addend;
405 // AArch64 code is emitted with .rela relocations. The data already in any
406 // bits affected by the relocation on entry is garbage.
407 *TargetPtr &= 0xffe0001fU;
408 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
409 *TargetPtr |= Result >> (48 - 5);
410 // Shift must be "lsl #48", in bits 22:21
411 assert((*TargetPtr >> 21 & 0x3) == 3 && "invalid shift for relocation");
414 case ELF::R_AARCH64_MOVW_UABS_G2_NC: {
415 uint64_t Result = Value + Addend;
417 // AArch64 code is emitted with .rela relocations. The data already in any
418 // bits affected by the relocation on entry is garbage.
419 *TargetPtr &= 0xffe0001fU;
420 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
421 *TargetPtr |= ((Result & 0xffff00000000ULL) >> (32 - 5));
422 // Shift must be "lsl #32", in bits 22:21
423 assert((*TargetPtr >> 21 & 0x3) == 2 && "invalid shift for relocation");
426 case ELF::R_AARCH64_MOVW_UABS_G1_NC: {
427 uint64_t Result = Value + Addend;
429 // AArch64 code is emitted with .rela relocations. The data already in any
430 // bits affected by the relocation on entry is garbage.
431 *TargetPtr &= 0xffe0001fU;
432 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
433 *TargetPtr |= ((Result & 0xffff0000U) >> (16 - 5));
434 // Shift must be "lsl #16", in bits 22:2
435 assert((*TargetPtr >> 21 & 0x3) == 1 && "invalid shift for relocation");
438 case ELF::R_AARCH64_MOVW_UABS_G0_NC: {
439 uint64_t Result = Value + Addend;
441 // AArch64 code is emitted with .rela relocations. The data already in any
442 // bits affected by the relocation on entry is garbage.
443 *TargetPtr &= 0xffe0001fU;
444 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
445 *TargetPtr |= ((Result & 0xffffU) << 5);
446 // Shift must be "lsl #0", in bits 22:21.
447 assert((*TargetPtr >> 21 & 0x3) == 0 && "invalid shift for relocation");
450 case ELF::R_AARCH64_ADR_PREL_PG_HI21: {
451 // Operation: Page(S+A) - Page(P)
453 ((Value + Addend) & ~0xfffULL) - (FinalAddress & ~0xfffULL);
455 // Check that -2^32 <= X < 2^32
456 assert(static_cast<int64_t>(Result) >= (-1LL << 32) &&
457 static_cast<int64_t>(Result) < (1LL << 32) &&
458 "overflow check failed for relocation");
460 // AArch64 code is emitted with .rela relocations. The data already in any
461 // bits affected by the relocation on entry is garbage.
462 *TargetPtr &= 0x9f00001fU;
463 // Immediate goes in bits 30:29 + 5:23 of ADRP instruction, taken
464 // from bits 32:12 of X.
465 *TargetPtr |= ((Result & 0x3000U) << (29 - 12));
466 *TargetPtr |= ((Result & 0x1ffffc000ULL) >> (14 - 5));
469 case ELF::R_AARCH64_LDST32_ABS_LO12_NC: {
471 uint64_t Result = Value + Addend;
473 // AArch64 code is emitted with .rela relocations. The data already in any
474 // bits affected by the relocation on entry is garbage.
475 *TargetPtr &= 0xffc003ffU;
476 // Immediate goes in bits 21:10 of LD/ST instruction, taken
477 // from bits 11:2 of X
478 *TargetPtr |= ((Result & 0xffc) << (10 - 2));
481 case ELF::R_AARCH64_LDST64_ABS_LO12_NC: {
483 uint64_t Result = Value + Addend;
485 // AArch64 code is emitted with .rela relocations. The data already in any
486 // bits affected by the relocation on entry is garbage.
487 *TargetPtr &= 0xffc003ffU;
488 // Immediate goes in bits 21:10 of LD/ST instruction, taken
489 // from bits 11:3 of X
490 *TargetPtr |= ((Result & 0xff8) << (10 - 3));
496 void RuntimeDyldELF::resolveARMRelocation(const SectionEntry &Section,
497 uint64_t Offset, uint32_t Value,
498 uint32_t Type, int32_t Addend) {
499 // TODO: Add Thumb relocations.
500 uint32_t *Placeholder =
501 reinterpret_cast<uint32_t *>(Section.ObjAddress + Offset);
502 uint32_t *TargetPtr = (uint32_t *)(Section.Address + Offset);
503 uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
506 DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: "
507 << Section.Address + Offset
508 << " FinalAddress: " << format("%p", FinalAddress) << " Value: "
509 << format("%x", Value) << " Type: " << format("%x", Type)
510 << " Addend: " << format("%x", Addend) << "\n");
514 llvm_unreachable("Not implemented relocation type!");
516 case ELF::R_ARM_NONE:
518 // Write a 32bit value to relocation address, taking into account the
519 // implicit addend encoded in the target.
520 case ELF::R_ARM_PREL31:
521 case ELF::R_ARM_TARGET1:
522 case ELF::R_ARM_ABS32:
523 *TargetPtr = *Placeholder + Value;
525 // Write first 16 bit of 32 bit value to the mov instruction.
526 // Last 4 bit should be shifted.
527 case ELF::R_ARM_MOVW_ABS_NC:
528 // We are not expecting any other addend in the relocation address.
529 // Using 0x000F0FFF because MOVW has its 16 bit immediate split into 2
530 // non-contiguous fields.
531 assert((*Placeholder & 0x000F0FFF) == 0);
532 Value = Value & 0xFFFF;
533 *TargetPtr = *Placeholder | (Value & 0xFFF);
534 *TargetPtr |= ((Value >> 12) & 0xF) << 16;
536 // Write last 16 bit of 32 bit value to the mov instruction.
537 // Last 4 bit should be shifted.
538 case ELF::R_ARM_MOVT_ABS:
539 // We are not expecting any other addend in the relocation address.
540 // Use 0x000F0FFF for the same reason as R_ARM_MOVW_ABS_NC.
541 assert((*Placeholder & 0x000F0FFF) == 0);
543 Value = (Value >> 16) & 0xFFFF;
544 *TargetPtr = *Placeholder | (Value & 0xFFF);
545 *TargetPtr |= ((Value >> 12) & 0xF) << 16;
547 // Write 24 bit relative value to the branch instruction.
548 case ELF::R_ARM_PC24: // Fall through.
549 case ELF::R_ARM_CALL: // Fall through.
550 case ELF::R_ARM_JUMP24: {
551 int32_t RelValue = static_cast<int32_t>(Value - FinalAddress - 8);
552 RelValue = (RelValue & 0x03FFFFFC) >> 2;
553 assert((*TargetPtr & 0xFFFFFF) == 0xFFFFFE);
554 *TargetPtr &= 0xFF000000;
555 *TargetPtr |= RelValue;
558 case ELF::R_ARM_PRIVATE_0:
559 // This relocation is reserved by the ARM ELF ABI for internal use. We
560 // appropriate it here to act as an R_ARM_ABS32 without any addend for use
561 // in the stubs created during JIT (which can't put an addend into the
562 // original object file).
568 void RuntimeDyldELF::resolveMIPSRelocation(const SectionEntry &Section,
569 uint64_t Offset, uint32_t Value,
570 uint32_t Type, int32_t Addend) {
571 uint32_t *Placeholder =
572 reinterpret_cast<uint32_t *>(Section.ObjAddress + Offset);
573 uint32_t *TargetPtr = (uint32_t *)(Section.Address + Offset);
576 DEBUG(dbgs() << "resolveMipselocation, LocalAddress: "
577 << Section.Address + Offset << " FinalAddress: "
578 << format("%p", Section.LoadAddress + Offset) << " Value: "
579 << format("%x", Value) << " Type: " << format("%x", Type)
580 << " Addend: " << format("%x", Addend) << "\n");
584 llvm_unreachable("Not implemented relocation type!");
587 *TargetPtr = Value + (*Placeholder);
590 *TargetPtr = ((*Placeholder) & 0xfc000000) | ((Value & 0x0fffffff) >> 2);
592 case ELF::R_MIPS_HI16:
593 // Get the higher 16-bits. Also add 1 if bit 15 is 1.
594 Value += ((*Placeholder) & 0x0000ffff) << 16;
596 ((*Placeholder) & 0xffff0000) | (((Value + 0x8000) >> 16) & 0xffff);
598 case ELF::R_MIPS_LO16:
599 Value += ((*Placeholder) & 0x0000ffff);
600 *TargetPtr = ((*Placeholder) & 0xffff0000) | (Value & 0xffff);
602 case ELF::R_MIPS_UNUSED1:
603 // Similar to ELF::R_ARM_PRIVATE_0, R_MIPS_UNUSED1 and R_MIPS_UNUSED2
604 // are used for internal JIT purpose. These relocations are similar to
605 // R_MIPS_HI16 and R_MIPS_LO16, but they do not take any addend into
608 ((*TargetPtr) & 0xffff0000) | (((Value + 0x8000) >> 16) & 0xffff);
610 case ELF::R_MIPS_UNUSED2:
611 *TargetPtr = ((*TargetPtr) & 0xffff0000) | (Value & 0xffff);
616 // Return the .TOC. section address to R_PPC64_TOC relocations.
617 uint64_t RuntimeDyldELF::findPPC64TOC() const {
618 // The TOC consists of sections .got, .toc, .tocbss, .plt in that
619 // order. The TOC starts where the first of these sections starts.
620 SectionList::const_iterator it = Sections.begin();
621 SectionList::const_iterator ite = Sections.end();
622 for (; it != ite; ++it) {
623 if (it->Name == ".got" || it->Name == ".toc" || it->Name == ".tocbss" ||
628 // This may happen for
629 // * references to TOC base base (sym@toc, .odp relocation) without
631 // In this case just use the first section (which is usually
632 // the .odp) since the code won't reference the .toc base
634 it = Sections.begin();
637 // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000
638 // thus permitting a full 64 Kbytes segment.
639 return it->LoadAddress + 0x8000;
642 // Returns the sections and offset associated with the ODP entry referenced
644 void RuntimeDyldELF::findOPDEntrySection(ObjectImage &Obj,
645 ObjSectionToIDMap &LocalSections,
646 RelocationValueRef &Rel) {
647 // Get the ELF symbol value (st_value) to compare with Relocation offset in
649 for (section_iterator si = Obj.begin_sections(), se = Obj.end_sections();
651 section_iterator RelSecI = si->getRelocatedSection();
652 if (RelSecI == Obj.end_sections())
655 StringRef RelSectionName;
656 check(RelSecI->getName(RelSectionName));
657 if (RelSectionName != ".opd")
660 for (relocation_iterator i = si->relocation_begin(),
661 e = si->relocation_end();
663 // The R_PPC64_ADDR64 relocation indicates the first field
666 check(i->getType(TypeFunc));
667 if (TypeFunc != ELF::R_PPC64_ADDR64) {
672 uint64_t TargetSymbolOffset;
673 symbol_iterator TargetSymbol = i->getSymbol();
674 check(i->getOffset(TargetSymbolOffset));
676 check(getELFRelocationAddend(*i, Addend));
682 // Just check if following relocation is a R_PPC64_TOC
684 check(i->getType(TypeTOC));
685 if (TypeTOC != ELF::R_PPC64_TOC)
688 // Finally compares the Symbol value and the target symbol offset
689 // to check if this .opd entry refers to the symbol the relocation
691 if (Rel.Addend != (int64_t)TargetSymbolOffset)
694 section_iterator tsi(Obj.end_sections());
695 check(TargetSymbol->getSection(tsi));
698 Rel.SectionID = findOrEmitSection(Obj, (*tsi), IsCode, LocalSections);
699 Rel.Addend = (intptr_t)Addend;
703 llvm_unreachable("Attempting to get address of ODP entry!");
706 // Relocation masks following the #lo(value), #hi(value), #higher(value),
707 // and #highest(value) macros defined in section 4.5.1. Relocation Types
708 // in PPC-elf64abi document.
710 static inline uint16_t applyPPClo(uint64_t value) { return value & 0xffff; }
712 static inline uint16_t applyPPChi(uint64_t value) {
713 return (value >> 16) & 0xffff;
716 static inline uint16_t applyPPChigher(uint64_t value) {
717 return (value >> 32) & 0xffff;
720 static inline uint16_t applyPPChighest(uint64_t value) {
721 return (value >> 48) & 0xffff;
724 void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section,
725 uint64_t Offset, uint64_t Value,
726 uint32_t Type, int64_t Addend) {
727 uint8_t *LocalAddress = Section.Address + Offset;
730 llvm_unreachable("Relocation type not implemented yet!");
732 case ELF::R_PPC64_ADDR16_LO:
733 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
735 case ELF::R_PPC64_ADDR16_HI:
736 writeInt16BE(LocalAddress, applyPPChi(Value + Addend));
738 case ELF::R_PPC64_ADDR16_HIGHER:
739 writeInt16BE(LocalAddress, applyPPChigher(Value + Addend));
741 case ELF::R_PPC64_ADDR16_HIGHEST:
742 writeInt16BE(LocalAddress, applyPPChighest(Value + Addend));
744 case ELF::R_PPC64_ADDR14: {
745 assert(((Value + Addend) & 3) == 0);
746 // Preserve the AA/LK bits in the branch instruction
747 uint8_t aalk = *(LocalAddress + 3);
748 writeInt16BE(LocalAddress + 2, (aalk & 3) | ((Value + Addend) & 0xfffc));
750 case ELF::R_PPC64_ADDR32: {
751 int32_t Result = static_cast<int32_t>(Value + Addend);
752 if (SignExtend32<32>(Result) != Result)
753 llvm_unreachable("Relocation R_PPC64_ADDR32 overflow");
754 writeInt32BE(LocalAddress, Result);
756 case ELF::R_PPC64_REL24: {
757 uint64_t FinalAddress = (Section.LoadAddress + Offset);
758 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
759 if (SignExtend32<24>(delta) != delta)
760 llvm_unreachable("Relocation R_PPC64_REL24 overflow");
761 // Generates a 'bl <address>' instruction
762 writeInt32BE(LocalAddress, 0x48000001 | (delta & 0x03FFFFFC));
764 case ELF::R_PPC64_REL32: {
765 uint64_t FinalAddress = (Section.LoadAddress + Offset);
766 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
767 if (SignExtend32<32>(delta) != delta)
768 llvm_unreachable("Relocation R_PPC64_REL32 overflow");
769 writeInt32BE(LocalAddress, delta);
771 case ELF::R_PPC64_REL64: {
772 uint64_t FinalAddress = (Section.LoadAddress + Offset);
773 uint64_t Delta = Value - FinalAddress + Addend;
774 writeInt64BE(LocalAddress, Delta);
776 case ELF::R_PPC64_ADDR64:
777 writeInt64BE(LocalAddress, Value + Addend);
779 case ELF::R_PPC64_TOC:
780 writeInt64BE(LocalAddress, findPPC64TOC());
782 case ELF::R_PPC64_TOC16: {
783 uint64_t TOCStart = findPPC64TOC();
784 Value = applyPPClo((Value + Addend) - TOCStart);
785 writeInt16BE(LocalAddress, applyPPClo(Value));
787 case ELF::R_PPC64_TOC16_DS: {
788 uint64_t TOCStart = findPPC64TOC();
789 Value = ((Value + Addend) - TOCStart);
790 writeInt16BE(LocalAddress, applyPPClo(Value));
795 void RuntimeDyldELF::resolveSystemZRelocation(const SectionEntry &Section,
796 uint64_t Offset, uint64_t Value,
797 uint32_t Type, int64_t Addend) {
798 uint8_t *LocalAddress = Section.Address + Offset;
801 llvm_unreachable("Relocation type not implemented yet!");
803 case ELF::R_390_PC16DBL:
804 case ELF::R_390_PLT16DBL: {
805 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
806 assert(int16_t(Delta / 2) * 2 == Delta && "R_390_PC16DBL overflow");
807 writeInt16BE(LocalAddress, Delta / 2);
810 case ELF::R_390_PC32DBL:
811 case ELF::R_390_PLT32DBL: {
812 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
813 assert(int32_t(Delta / 2) * 2 == Delta && "R_390_PC32DBL overflow");
814 writeInt32BE(LocalAddress, Delta / 2);
817 case ELF::R_390_PC32: {
818 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
819 assert(int32_t(Delta) == Delta && "R_390_PC32 overflow");
820 writeInt32BE(LocalAddress, Delta);
824 writeInt64BE(LocalAddress, Value + Addend);
829 // The target location for the relocation is described by RE.SectionID and
830 // RE.Offset. RE.SectionID can be used to find the SectionEntry. Each
831 // SectionEntry has three members describing its location.
832 // SectionEntry::Address is the address at which the section has been loaded
833 // into memory in the current (host) process. SectionEntry::LoadAddress is the
834 // address that the section will have in the target process.
835 // SectionEntry::ObjAddress is the address of the bits for this section in the
836 // original emitted object image (also in the current address space).
838 // Relocations will be applied as if the section were loaded at
839 // SectionEntry::LoadAddress, but they will be applied at an address based
840 // on SectionEntry::Address. SectionEntry::ObjAddress will be used to refer to
841 // Target memory contents if they are required for value calculations.
843 // The Value parameter here is the load address of the symbol for the
844 // relocation to be applied. For relocations which refer to symbols in the
845 // current object Value will be the LoadAddress of the section in which
846 // the symbol resides (RE.Addend provides additional information about the
847 // symbol location). For external symbols, Value will be the address of the
848 // symbol in the target address space.
849 void RuntimeDyldELF::resolveRelocation(const RelocationEntry &RE,
851 const SectionEntry &Section = Sections[RE.SectionID];
852 return resolveRelocation(Section, RE.Offset, Value, RE.RelType, RE.Addend,
856 void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section,
857 uint64_t Offset, uint64_t Value,
858 uint32_t Type, int64_t Addend,
859 uint64_t SymOffset) {
862 resolveX86_64Relocation(Section, Offset, Value, Type, Addend, SymOffset);
865 resolveX86Relocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
866 (uint32_t)(Addend & 0xffffffffL));
868 case Triple::aarch64:
869 case Triple::aarch64_be:
871 case Triple::arm64_be:
872 resolveAArch64Relocation(Section, Offset, Value, Type, Addend);
874 case Triple::arm: // Fall through.
877 case Triple::thumbeb:
878 resolveARMRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
879 (uint32_t)(Addend & 0xffffffffL));
881 case Triple::mips: // Fall through.
883 resolveMIPSRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL),
884 Type, (uint32_t)(Addend & 0xffffffffL));
886 case Triple::ppc64: // Fall through.
887 case Triple::ppc64le:
888 resolvePPC64Relocation(Section, Offset, Value, Type, Addend);
890 case Triple::systemz:
891 resolveSystemZRelocation(Section, Offset, Value, Type, Addend);
894 llvm_unreachable("Unsupported CPU type!");
898 relocation_iterator RuntimeDyldELF::processRelocationRef(
899 unsigned SectionID, relocation_iterator RelI, ObjectImage &Obj,
900 ObjSectionToIDMap &ObjSectionToID, const SymbolTableMap &Symbols,
903 Check(RelI->getType(RelType));
905 Check(getELFRelocationAddend(*RelI, Addend));
906 symbol_iterator Symbol = RelI->getSymbol();
908 // Obtain the symbol name which is referenced in the relocation
909 StringRef TargetName;
910 if (Symbol != Obj.end_symbols())
911 Symbol->getName(TargetName);
912 DEBUG(dbgs() << "\t\tRelType: " << RelType << " Addend: " << Addend
913 << " TargetName: " << TargetName << "\n");
914 RelocationValueRef Value;
915 // First search for the symbol in the local symbol table
916 SymbolTableMap::const_iterator lsi = Symbols.end();
917 SymbolRef::Type SymType = SymbolRef::ST_Unknown;
918 if (Symbol != Obj.end_symbols()) {
919 lsi = Symbols.find(TargetName.data());
920 Symbol->getType(SymType);
922 if (lsi != Symbols.end()) {
923 Value.SectionID = lsi->second.first;
924 Value.Offset = lsi->second.second;
925 Value.Addend = lsi->second.second + Addend;
927 // Search for the symbol in the global symbol table
928 SymbolTableMap::const_iterator gsi = GlobalSymbolTable.end();
929 if (Symbol != Obj.end_symbols())
930 gsi = GlobalSymbolTable.find(TargetName.data());
931 if (gsi != GlobalSymbolTable.end()) {
932 Value.SectionID = gsi->second.first;
933 Value.Offset = gsi->second.second;
934 Value.Addend = gsi->second.second + Addend;
937 case SymbolRef::ST_Debug: {
938 // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously
939 // and can be changed by another developers. Maybe best way is add
940 // a new symbol type ST_Section to SymbolRef and use it.
941 section_iterator si(Obj.end_sections());
942 Symbol->getSection(si);
943 if (si == Obj.end_sections())
944 llvm_unreachable("Symbol section not found, bad object file format!");
945 DEBUG(dbgs() << "\t\tThis is section symbol\n");
946 // Default to 'true' in case isText fails (though it never does).
949 Value.SectionID = findOrEmitSection(Obj, (*si), isCode, ObjSectionToID);
950 Value.Addend = Addend;
953 case SymbolRef::ST_Data:
954 case SymbolRef::ST_Unknown: {
955 Value.SymbolName = TargetName.data();
956 Value.Addend = Addend;
958 // Absolute relocations will have a zero symbol ID (STN_UNDEF), which
959 // will manifest here as a NULL symbol name.
960 // We can set this as a valid (but empty) symbol name, and rely
961 // on addRelocationForSymbol to handle this.
962 if (!Value.SymbolName)
963 Value.SymbolName = "";
967 llvm_unreachable("Unresolved symbol type!");
973 Check(RelI->getOffset(Offset));
975 DEBUG(dbgs() << "\t\tSectionID: " << SectionID << " Offset: " << Offset
977 if ((Arch == Triple::aarch64 || Arch == Triple::aarch64_be ||
978 Arch == Triple::arm64 || Arch == Triple::arm64_be) &&
979 (RelType == ELF::R_AARCH64_CALL26 || RelType == ELF::R_AARCH64_JUMP26)) {
980 // This is an AArch64 branch relocation, need to use a stub function.
981 DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation.");
982 SectionEntry &Section = Sections[SectionID];
984 // Look for an existing stub.
985 StubMap::const_iterator i = Stubs.find(Value);
986 if (i != Stubs.end()) {
987 resolveRelocation(Section, Offset, (uint64_t)Section.Address + i->second,
989 DEBUG(dbgs() << " Stub function found\n");
991 // Create a new stub function.
992 DEBUG(dbgs() << " Create a new stub function\n");
993 Stubs[Value] = Section.StubOffset;
994 uint8_t *StubTargetAddr =
995 createStubFunction(Section.Address + Section.StubOffset);
997 RelocationEntry REmovz_g3(SectionID, StubTargetAddr - Section.Address,
998 ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend);
999 RelocationEntry REmovk_g2(SectionID, StubTargetAddr - Section.Address + 4,
1000 ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend);
1001 RelocationEntry REmovk_g1(SectionID, StubTargetAddr - Section.Address + 8,
1002 ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend);
1003 RelocationEntry REmovk_g0(SectionID,
1004 StubTargetAddr - Section.Address + 12,
1005 ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend);
1007 if (Value.SymbolName) {
1008 addRelocationForSymbol(REmovz_g3, Value.SymbolName);
1009 addRelocationForSymbol(REmovk_g2, Value.SymbolName);
1010 addRelocationForSymbol(REmovk_g1, Value.SymbolName);
1011 addRelocationForSymbol(REmovk_g0, Value.SymbolName);
1013 addRelocationForSection(REmovz_g3, Value.SectionID);
1014 addRelocationForSection(REmovk_g2, Value.SectionID);
1015 addRelocationForSection(REmovk_g1, Value.SectionID);
1016 addRelocationForSection(REmovk_g0, Value.SectionID);
1018 resolveRelocation(Section, Offset,
1019 (uint64_t)Section.Address + Section.StubOffset, RelType,
1021 Section.StubOffset += getMaxStubSize();
1023 } else if (Arch == Triple::arm &&
1024 (RelType == ELF::R_ARM_PC24 || RelType == ELF::R_ARM_CALL ||
1025 RelType == ELF::R_ARM_JUMP24)) {
1026 // This is an ARM branch relocation, need to use a stub function.
1027 DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.");
1028 SectionEntry &Section = Sections[SectionID];
1030 // Look for an existing stub.
1031 StubMap::const_iterator i = Stubs.find(Value);
1032 if (i != Stubs.end()) {
1033 resolveRelocation(Section, Offset, (uint64_t)Section.Address + i->second,
1035 DEBUG(dbgs() << " Stub function found\n");
1037 // Create a new stub function.
1038 DEBUG(dbgs() << " Create a new stub function\n");
1039 Stubs[Value] = Section.StubOffset;
1040 uint8_t *StubTargetAddr =
1041 createStubFunction(Section.Address + Section.StubOffset);
1042 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1043 ELF::R_ARM_PRIVATE_0, Value.Addend);
1044 if (Value.SymbolName)
1045 addRelocationForSymbol(RE, Value.SymbolName);
1047 addRelocationForSection(RE, Value.SectionID);
1049 resolveRelocation(Section, Offset,
1050 (uint64_t)Section.Address + Section.StubOffset, RelType,
1052 Section.StubOffset += getMaxStubSize();
1054 } else if ((Arch == Triple::mipsel || Arch == Triple::mips) &&
1055 RelType == ELF::R_MIPS_26) {
1056 // This is an Mips branch relocation, need to use a stub function.
1057 DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
1058 SectionEntry &Section = Sections[SectionID];
1059 uint8_t *Target = Section.Address + Offset;
1060 uint32_t *TargetAddress = (uint32_t *)Target;
1062 // Extract the addend from the instruction.
1063 uint32_t Addend = ((*TargetAddress) & 0x03ffffff) << 2;
1065 Value.Addend += Addend;
1067 // Look up for existing stub.
1068 StubMap::const_iterator i = Stubs.find(Value);
1069 if (i != Stubs.end()) {
1070 RelocationEntry RE(SectionID, Offset, RelType, i->second);
1071 addRelocationForSection(RE, SectionID);
1072 DEBUG(dbgs() << " Stub function found\n");
1074 // Create a new stub function.
1075 DEBUG(dbgs() << " Create a new stub function\n");
1076 Stubs[Value] = Section.StubOffset;
1077 uint8_t *StubTargetAddr =
1078 createStubFunction(Section.Address + Section.StubOffset);
1080 // Creating Hi and Lo relocations for the filled stub instructions.
1081 RelocationEntry REHi(SectionID, StubTargetAddr - Section.Address,
1082 ELF::R_MIPS_UNUSED1, Value.Addend);
1083 RelocationEntry RELo(SectionID, StubTargetAddr - Section.Address + 4,
1084 ELF::R_MIPS_UNUSED2, Value.Addend);
1086 if (Value.SymbolName) {
1087 addRelocationForSymbol(REHi, Value.SymbolName);
1088 addRelocationForSymbol(RELo, Value.SymbolName);
1090 addRelocationForSection(REHi, Value.SectionID);
1091 addRelocationForSection(RELo, Value.SectionID);
1094 RelocationEntry RE(SectionID, Offset, RelType, Section.StubOffset);
1095 addRelocationForSection(RE, SectionID);
1096 Section.StubOffset += getMaxStubSize();
1098 } else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) {
1099 if (RelType == ELF::R_PPC64_REL24) {
1100 // A PPC branch relocation will need a stub function if the target is
1101 // an external symbol (Symbol::ST_Unknown) or if the target address
1102 // is not within the signed 24-bits branch address.
1103 SectionEntry &Section = Sections[SectionID];
1104 uint8_t *Target = Section.Address + Offset;
1105 bool RangeOverflow = false;
1106 if (SymType != SymbolRef::ST_Unknown) {
1107 // A function call may points to the .opd entry, so the final symbol
1109 // in calculated based in the relocation values in .opd section.
1110 findOPDEntrySection(Obj, ObjSectionToID, Value);
1111 uint8_t *RelocTarget = Sections[Value.SectionID].Address + Value.Addend;
1112 int32_t delta = static_cast<int32_t>(Target - RelocTarget);
1113 // If it is within 24-bits branch range, just set the branch target
1114 if (SignExtend32<24>(delta) == delta) {
1115 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1116 if (Value.SymbolName)
1117 addRelocationForSymbol(RE, Value.SymbolName);
1119 addRelocationForSection(RE, Value.SectionID);
1121 RangeOverflow = true;
1124 if (SymType == SymbolRef::ST_Unknown || RangeOverflow == true) {
1125 // It is an external symbol (SymbolRef::ST_Unknown) or within a range
1126 // larger than 24-bits.
1127 StubMap::const_iterator i = Stubs.find(Value);
1128 if (i != Stubs.end()) {
1129 // Symbol function stub already created, just relocate to it
1130 resolveRelocation(Section, Offset,
1131 (uint64_t)Section.Address + i->second, RelType, 0);
1132 DEBUG(dbgs() << " Stub function found\n");
1134 // Create a new stub function.
1135 DEBUG(dbgs() << " Create a new stub function\n");
1136 Stubs[Value] = Section.StubOffset;
1137 uint8_t *StubTargetAddr =
1138 createStubFunction(Section.Address + Section.StubOffset);
1139 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1140 ELF::R_PPC64_ADDR64, Value.Addend);
1142 // Generates the 64-bits address loads as exemplified in section
1143 // 4.5.1 in PPC64 ELF ABI.
1144 RelocationEntry REhst(SectionID, StubTargetAddr - Section.Address + 2,
1145 ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend);
1146 RelocationEntry REhr(SectionID, StubTargetAddr - Section.Address + 6,
1147 ELF::R_PPC64_ADDR16_HIGHER, Value.Addend);
1148 RelocationEntry REh(SectionID, StubTargetAddr - Section.Address + 14,
1149 ELF::R_PPC64_ADDR16_HI, Value.Addend);
1150 RelocationEntry REl(SectionID, StubTargetAddr - Section.Address + 18,
1151 ELF::R_PPC64_ADDR16_LO, Value.Addend);
1153 if (Value.SymbolName) {
1154 addRelocationForSymbol(REhst, Value.SymbolName);
1155 addRelocationForSymbol(REhr, Value.SymbolName);
1156 addRelocationForSymbol(REh, Value.SymbolName);
1157 addRelocationForSymbol(REl, Value.SymbolName);
1159 addRelocationForSection(REhst, Value.SectionID);
1160 addRelocationForSection(REhr, Value.SectionID);
1161 addRelocationForSection(REh, Value.SectionID);
1162 addRelocationForSection(REl, Value.SectionID);
1165 resolveRelocation(Section, Offset,
1166 (uint64_t)Section.Address + Section.StubOffset,
1168 Section.StubOffset += getMaxStubSize();
1170 if (SymType == SymbolRef::ST_Unknown)
1171 // Restore the TOC for external calls
1172 writeInt32BE(Target + 4, 0xE8410028); // ld r2,40(r1)
1175 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1176 // Extra check to avoid relocation againt empty symbols (usually
1177 // the R_PPC64_TOC).
1178 if (SymType != SymbolRef::ST_Unknown && TargetName.empty())
1179 Value.SymbolName = nullptr;
1181 if (Value.SymbolName)
1182 addRelocationForSymbol(RE, Value.SymbolName);
1184 addRelocationForSection(RE, Value.SectionID);
1186 } else if (Arch == Triple::systemz &&
1187 (RelType == ELF::R_390_PLT32DBL || RelType == ELF::R_390_GOTENT)) {
1188 // Create function stubs for both PLT and GOT references, regardless of
1189 // whether the GOT reference is to data or code. The stub contains the
1190 // full address of the symbol, as needed by GOT references, and the
1191 // executable part only adds an overhead of 8 bytes.
1193 // We could try to conserve space by allocating the code and data
1194 // parts of the stub separately. However, as things stand, we allocate
1195 // a stub for every relocation, so using a GOT in JIT code should be
1196 // no less space efficient than using an explicit constant pool.
1197 DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation.");
1198 SectionEntry &Section = Sections[SectionID];
1200 // Look for an existing stub.
1201 StubMap::const_iterator i = Stubs.find(Value);
1202 uintptr_t StubAddress;
1203 if (i != Stubs.end()) {
1204 StubAddress = uintptr_t(Section.Address) + i->second;
1205 DEBUG(dbgs() << " Stub function found\n");
1207 // Create a new stub function.
1208 DEBUG(dbgs() << " Create a new stub function\n");
1210 uintptr_t BaseAddress = uintptr_t(Section.Address);
1211 uintptr_t StubAlignment = getStubAlignment();
1212 StubAddress = (BaseAddress + Section.StubOffset + StubAlignment - 1) &
1214 unsigned StubOffset = StubAddress - BaseAddress;
1216 Stubs[Value] = StubOffset;
1217 createStubFunction((uint8_t *)StubAddress);
1218 RelocationEntry RE(SectionID, StubOffset + 8, ELF::R_390_64,
1219 Value.Addend - Addend);
1220 if (Value.SymbolName)
1221 addRelocationForSymbol(RE, Value.SymbolName);
1223 addRelocationForSection(RE, Value.SectionID);
1224 Section.StubOffset = StubOffset + getMaxStubSize();
1227 if (RelType == ELF::R_390_GOTENT)
1228 resolveRelocation(Section, Offset, StubAddress + 8, ELF::R_390_PC32DBL,
1231 resolveRelocation(Section, Offset, StubAddress, RelType, Addend);
1232 } else if (Arch == Triple::x86_64 && RelType == ELF::R_X86_64_PLT32) {
1233 // The way the PLT relocations normally work is that the linker allocates
1235 // PLT and this relocation makes a PC-relative call into the PLT. The PLT
1236 // entry will then jump to an address provided by the GOT. On first call,
1238 // GOT address will point back into PLT code that resolves the symbol. After
1239 // the first call, the GOT entry points to the actual function.
1241 // For local functions we're ignoring all of that here and just replacing
1242 // the PLT32 relocation type with PC32, which will translate the relocation
1243 // into a PC-relative call directly to the function. For external symbols we
1244 // can't be sure the function will be within 2^32 bytes of the call site, so
1245 // we need to create a stub, which calls into the GOT. This case is
1246 // equivalent to the usual PLT implementation except that we use the stub
1247 // mechanism in RuntimeDyld (which puts stubs at the end of the section)
1248 // rather than allocating a PLT section.
1249 if (Value.SymbolName) {
1250 // This is a call to an external function.
1251 // Look for an existing stub.
1252 SectionEntry &Section = Sections[SectionID];
1253 StubMap::const_iterator i = Stubs.find(Value);
1254 uintptr_t StubAddress;
1255 if (i != Stubs.end()) {
1256 StubAddress = uintptr_t(Section.Address) + i->second;
1257 DEBUG(dbgs() << " Stub function found\n");
1259 // Create a new stub function (equivalent to a PLT entry).
1260 DEBUG(dbgs() << " Create a new stub function\n");
1262 uintptr_t BaseAddress = uintptr_t(Section.Address);
1263 uintptr_t StubAlignment = getStubAlignment();
1264 StubAddress = (BaseAddress + Section.StubOffset + StubAlignment - 1) &
1266 unsigned StubOffset = StubAddress - BaseAddress;
1267 Stubs[Value] = StubOffset;
1268 createStubFunction((uint8_t *)StubAddress);
1270 // Create a GOT entry for the external function.
1271 GOTEntries.push_back(Value);
1273 // Make our stub function a relative call to the GOT entry.
1274 RelocationEntry RE(SectionID, StubOffset + 2, ELF::R_X86_64_GOTPCREL,
1276 addRelocationForSymbol(RE, Value.SymbolName);
1278 // Bump our stub offset counter
1279 Section.StubOffset = StubOffset + getMaxStubSize();
1282 // Make the target call a call into the stub table.
1283 resolveRelocation(Section, Offset, StubAddress, ELF::R_X86_64_PC32,
1286 RelocationEntry RE(SectionID, Offset, ELF::R_X86_64_PC32, Value.Addend,
1288 addRelocationForSection(RE, Value.SectionID);
1291 if (Arch == Triple::x86_64 && RelType == ELF::R_X86_64_GOTPCREL) {
1292 GOTEntries.push_back(Value);
1294 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend, Value.Offset);
1295 if (Value.SymbolName)
1296 addRelocationForSymbol(RE, Value.SymbolName);
1298 addRelocationForSection(RE, Value.SectionID);
1303 void RuntimeDyldELF::updateGOTEntries(StringRef Name, uint64_t Addr) {
1305 SmallVectorImpl<std::pair<SID, GOTRelocations>>::iterator it;
1306 SmallVectorImpl<std::pair<SID, GOTRelocations>>::iterator end = GOTs.end();
1308 for (it = GOTs.begin(); it != end; ++it) {
1309 GOTRelocations &GOTEntries = it->second;
1310 for (int i = 0, e = GOTEntries.size(); i != e; ++i) {
1311 if (GOTEntries[i].SymbolName != nullptr &&
1312 GOTEntries[i].SymbolName == Name) {
1313 GOTEntries[i].Offset = Addr;
1319 size_t RuntimeDyldELF::getGOTEntrySize() {
1320 // We don't use the GOT in all of these cases, but it's essentially free
1321 // to put them all here.
1324 case Triple::x86_64:
1325 case Triple::aarch64:
1326 case Triple::aarch64_be:
1328 case Triple::arm64_be:
1330 case Triple::ppc64le:
1331 case Triple::systemz:
1332 Result = sizeof(uint64_t);
1338 case Triple::mipsel:
1339 Result = sizeof(uint32_t);
1342 llvm_unreachable("Unsupported CPU type!");
1347 uint64_t RuntimeDyldELF::findGOTEntry(uint64_t LoadAddress, uint64_t Offset) {
1349 const size_t GOTEntrySize = getGOTEntrySize();
1351 SmallVectorImpl<std::pair<SID, GOTRelocations>>::const_iterator it;
1352 SmallVectorImpl<std::pair<SID, GOTRelocations>>::const_iterator end =
1356 for (it = GOTs.begin(); it != end; ++it) {
1357 SID GOTSectionID = it->first;
1358 const GOTRelocations &GOTEntries = it->second;
1360 // Find the matching entry in our vector.
1361 uint64_t SymbolOffset = 0;
1362 for (int i = 0, e = GOTEntries.size(); i != e; ++i) {
1363 if (!GOTEntries[i].SymbolName) {
1364 if (getSectionLoadAddress(GOTEntries[i].SectionID) == LoadAddress &&
1365 GOTEntries[i].Offset == Offset) {
1367 SymbolOffset = GOTEntries[i].Offset;
1371 // GOT entries for external symbols use the addend as the address when
1372 // the external symbol has been resolved.
1373 if (GOTEntries[i].Offset == LoadAddress) {
1375 // Don't use the Addend here. The relocation handler will use it.
1381 if (GOTIndex != -1) {
1382 if (GOTEntrySize == sizeof(uint64_t)) {
1383 uint64_t *LocalGOTAddr = (uint64_t *)getSectionAddress(GOTSectionID);
1384 // Fill in this entry with the address of the symbol being referenced.
1385 LocalGOTAddr[GOTIndex] = LoadAddress + SymbolOffset;
1387 uint32_t *LocalGOTAddr = (uint32_t *)getSectionAddress(GOTSectionID);
1388 // Fill in this entry with the address of the symbol being referenced.
1389 LocalGOTAddr[GOTIndex] = (uint32_t)(LoadAddress + SymbolOffset);
1392 // Calculate the load address of this entry
1393 return getSectionLoadAddress(GOTSectionID) + (GOTIndex * GOTEntrySize);
1397 assert(GOTIndex != -1 && "Unable to find requested GOT entry.");
1401 void RuntimeDyldELF::finalizeLoad(ObjectImage &ObjImg,
1402 ObjSectionToIDMap &SectionMap) {
1403 // If necessary, allocate the global offset table
1405 // Allocate the GOT if necessary
1406 size_t numGOTEntries = GOTEntries.size();
1407 if (numGOTEntries != 0) {
1408 // Allocate memory for the section
1409 unsigned SectionID = Sections.size();
1410 size_t TotalSize = numGOTEntries * getGOTEntrySize();
1411 uint8_t *Addr = MemMgr->allocateDataSection(TotalSize, getGOTEntrySize(),
1412 SectionID, ".got", false);
1414 report_fatal_error("Unable to allocate memory for GOT!");
1416 GOTs.push_back(std::make_pair(SectionID, GOTEntries));
1417 Sections.push_back(SectionEntry(".got", Addr, TotalSize, 0));
1418 // For now, initialize all GOT entries to zero. We'll fill them in as
1419 // needed when GOT-based relocations are applied.
1420 memset(Addr, 0, TotalSize);
1423 report_fatal_error("Unable to allocate memory for GOT!");
1426 // Look for and record the EH frame section.
1427 ObjSectionToIDMap::iterator i, e;
1428 for (i = SectionMap.begin(), e = SectionMap.end(); i != e; ++i) {
1429 const SectionRef &Section = i->first;
1431 Section.getName(Name);
1432 if (Name == ".eh_frame") {
1433 UnregisteredEHFrameSections.push_back(i->second);
1439 bool RuntimeDyldELF::isCompatibleFormat(const ObjectBuffer *Buffer) const {
1440 if (Buffer->getBufferSize() < strlen(ELF::ElfMagic))
1442 return (memcmp(Buffer->getBufferStart(), ELF::ElfMagic,
1443 strlen(ELF::ElfMagic))) == 0;
1446 bool RuntimeDyldELF::isCompatibleFile(const object::ObjectFile *Obj) const {
1447 return Obj->isELF();