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;
31 #define DEBUG_TYPE "dyld"
35 static inline std::error_code check(std::error_code Err) {
37 report_fatal_error(Err.message());
42 template <class ELFT> class DyldELFObject : public ELFObjectFile<ELFT> {
43 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
45 typedef Elf_Shdr_Impl<ELFT> Elf_Shdr;
46 typedef Elf_Sym_Impl<ELFT> Elf_Sym;
47 typedef Elf_Rel_Impl<ELFT, false> Elf_Rel;
48 typedef Elf_Rel_Impl<ELFT, true> Elf_Rela;
50 typedef Elf_Ehdr_Impl<ELFT> Elf_Ehdr;
52 typedef typename ELFDataTypeTypedefHelper<ELFT>::value_type addr_type;
54 std::unique_ptr<ObjectFile> UnderlyingFile;
57 DyldELFObject(std::unique_ptr<ObjectFile> UnderlyingFile,
58 MemoryBuffer *Wrapper, std::error_code &ec);
60 DyldELFObject(MemoryBuffer *Wrapper, std::error_code &ec);
62 void updateSectionAddress(const SectionRef &Sec, uint64_t Addr);
63 void updateSymbolAddress(const SymbolRef &Sym, uint64_t Addr);
65 // Methods for type inquiry through isa, cast and dyn_cast
66 static inline bool classof(const Binary *v) {
67 return (isa<ELFObjectFile<ELFT>>(v) &&
68 classof(cast<ELFObjectFile<ELFT>>(v)));
70 static inline bool classof(const ELFObjectFile<ELFT> *v) {
71 return v->isDyldType();
75 template <class ELFT> class ELFObjectImage : public ObjectImageCommon {
79 ELFObjectImage(ObjectBuffer *Input, std::unique_ptr<DyldELFObject<ELFT>> Obj)
80 : ObjectImageCommon(Input, std::move(Obj)), Registered(false) {}
82 virtual ~ELFObjectImage() {
84 deregisterWithDebugger();
87 // Subclasses can override these methods to update the image with loaded
88 // addresses for sections and common symbols
89 void updateSectionAddress(const SectionRef &Sec, uint64_t Addr) override {
90 static_cast<DyldELFObject<ELFT>*>(getObjectFile())
91 ->updateSectionAddress(Sec, Addr);
94 void updateSymbolAddress(const SymbolRef &Sym, uint64_t Addr) override {
95 static_cast<DyldELFObject<ELFT>*>(getObjectFile())
96 ->updateSymbolAddress(Sym, Addr);
99 void registerWithDebugger() override {
100 JITRegistrar::getGDBRegistrar().registerObject(*Buffer);
103 void deregisterWithDebugger() override {
104 JITRegistrar::getGDBRegistrar().deregisterObject(*Buffer);
108 // The MemoryBuffer passed into this constructor is just a wrapper around the
109 // actual memory. Ultimately, the Binary parent class will take ownership of
110 // this MemoryBuffer object but not the underlying memory.
111 template <class ELFT>
112 DyldELFObject<ELFT>::DyldELFObject(MemoryBuffer *Wrapper, std::error_code &ec)
113 : ELFObjectFile<ELFT>(Wrapper, ec) {
114 this->isDyldELFObject = true;
117 template <class ELFT>
118 DyldELFObject<ELFT>::DyldELFObject(std::unique_ptr<ObjectFile> UnderlyingFile,
119 MemoryBuffer *Wrapper, std::error_code &ec)
120 : ELFObjectFile<ELFT>(Wrapper, ec),
121 UnderlyingFile(std::move(UnderlyingFile)) {
122 this->isDyldELFObject = true;
125 template <class ELFT>
126 void DyldELFObject<ELFT>::updateSectionAddress(const SectionRef &Sec,
128 DataRefImpl ShdrRef = Sec.getRawDataRefImpl();
130 const_cast<Elf_Shdr *>(reinterpret_cast<const Elf_Shdr *>(ShdrRef.p));
132 // This assumes the address passed in matches the target address bitness
133 // The template-based type cast handles everything else.
134 shdr->sh_addr = static_cast<addr_type>(Addr);
137 template <class ELFT>
138 void DyldELFObject<ELFT>::updateSymbolAddress(const SymbolRef &SymRef,
141 Elf_Sym *sym = const_cast<Elf_Sym *>(
142 ELFObjectFile<ELFT>::getSymbol(SymRef.getRawDataRefImpl()));
144 // This assumes the address passed in matches the target address bitness
145 // The template-based type cast handles everything else.
146 sym->st_value = static_cast<addr_type>(Addr);
153 void RuntimeDyldELF::registerEHFrames() {
156 for (int i = 0, e = UnregisteredEHFrameSections.size(); i != e; ++i) {
157 SID EHFrameSID = UnregisteredEHFrameSections[i];
158 uint8_t *EHFrameAddr = Sections[EHFrameSID].Address;
159 uint64_t EHFrameLoadAddr = Sections[EHFrameSID].LoadAddress;
160 size_t EHFrameSize = Sections[EHFrameSID].Size;
161 MemMgr->registerEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
162 RegisteredEHFrameSections.push_back(EHFrameSID);
164 UnregisteredEHFrameSections.clear();
167 void RuntimeDyldELF::deregisterEHFrames() {
170 for (int i = 0, e = RegisteredEHFrameSections.size(); i != e; ++i) {
171 SID EHFrameSID = RegisteredEHFrameSections[i];
172 uint8_t *EHFrameAddr = Sections[EHFrameSID].Address;
173 uint64_t EHFrameLoadAddr = Sections[EHFrameSID].LoadAddress;
174 size_t EHFrameSize = Sections[EHFrameSID].Size;
175 MemMgr->deregisterEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
177 RegisteredEHFrameSections.clear();
181 RuntimeDyldELF::createObjectImageFromFile(std::unique_ptr<object::ObjectFile> ObjFile) {
186 MemoryBuffer *Buffer =
187 MemoryBuffer::getMemBuffer(ObjFile->getData(), "", false);
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 if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2LSB) {
225 llvm::make_unique<DyldELFObject<ELFType<support::little, 4, false>>>(
226 Buffer->getMemBuffer(), ec);
227 return new ELFObjectImage<ELFType<support::little, 4, false>>(
228 Buffer, std::move(Obj));
229 } else if (Ident.first == ELF::ELFCLASS32 &&
230 Ident.second == ELF::ELFDATA2MSB) {
232 llvm::make_unique<DyldELFObject<ELFType<support::big, 4, false>>>(
233 Buffer->getMemBuffer(), ec);
234 return new ELFObjectImage<ELFType<support::big, 4, false>>(Buffer,
236 } else if (Ident.first == ELF::ELFCLASS64 &&
237 Ident.second == ELF::ELFDATA2MSB) {
238 auto Obj = llvm::make_unique<DyldELFObject<ELFType<support::big, 8, true>>>(
239 Buffer->getMemBuffer(), ec);
240 return new ELFObjectImage<ELFType<support::big, 8, true>>(Buffer, std::move(Obj));
241 } else if (Ident.first == ELF::ELFCLASS64 &&
242 Ident.second == ELF::ELFDATA2LSB) {
244 llvm::make_unique<DyldELFObject<ELFType<support::little, 8, true>>>(
245 Buffer->getMemBuffer(), ec);
246 return new ELFObjectImage<ELFType<support::little, 8, true>>(Buffer, std::move(Obj));
248 llvm_unreachable("Unexpected ELF format");
251 RuntimeDyldELF::~RuntimeDyldELF() {}
253 void RuntimeDyldELF::resolveX86_64Relocation(const SectionEntry &Section,
254 uint64_t Offset, uint64_t Value,
255 uint32_t Type, int64_t Addend,
256 uint64_t SymOffset) {
259 llvm_unreachable("Relocation type not implemented yet!");
261 case ELF::R_X86_64_64: {
262 uint64_t *Target = reinterpret_cast<uint64_t *>(Section.Address + Offset);
263 *Target = Value + Addend;
264 DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend)) << " at "
265 << format("%p\n", Target));
268 case ELF::R_X86_64_32:
269 case ELF::R_X86_64_32S: {
271 assert((Type == ELF::R_X86_64_32 && (Value <= UINT32_MAX)) ||
272 (Type == ELF::R_X86_64_32S &&
273 ((int64_t)Value <= INT32_MAX && (int64_t)Value >= INT32_MIN)));
274 uint32_t TruncatedAddr = (Value & 0xFFFFFFFF);
275 uint32_t *Target = reinterpret_cast<uint32_t *>(Section.Address + Offset);
276 *Target = TruncatedAddr;
277 DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr) << " at "
278 << format("%p\n", Target));
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 uint32_t *Target = reinterpret_cast<uint32_t *>(Section.Address + Offset);
286 uint64_t FinalAddress = Section.LoadAddress + Offset;
287 // The processRelocationRef method combines the symbol offset and the addend
288 // and in most cases that's what we want. For this relocation type, we need
289 // the raw addend, so we subtract the symbol offset to get it.
290 int64_t RealOffset = GOTAddr + Addend - SymOffset - FinalAddress;
291 assert(RealOffset <= INT32_MAX && RealOffset >= INT32_MIN);
292 int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
293 *Target = TruncOffset;
296 case ELF::R_X86_64_PC32: {
297 // Get the placeholder value from the generated object since
298 // a previous relocation attempt may have overwritten the loaded version
299 uint32_t *Placeholder =
300 reinterpret_cast<uint32_t *>(Section.ObjAddress + Offset);
301 uint32_t *Target = reinterpret_cast<uint32_t *>(Section.Address + Offset);
302 uint64_t FinalAddress = Section.LoadAddress + Offset;
303 int64_t RealOffset = *Placeholder + Value + Addend - FinalAddress;
304 assert(RealOffset <= INT32_MAX && RealOffset >= INT32_MIN);
305 int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
306 *Target = TruncOffset;
309 case ELF::R_X86_64_PC64: {
310 // Get the placeholder value from the generated object since
311 // a previous relocation attempt may have overwritten the loaded version
312 uint64_t *Placeholder =
313 reinterpret_cast<uint64_t *>(Section.ObjAddress + Offset);
314 uint64_t *Target = reinterpret_cast<uint64_t *>(Section.Address + Offset);
315 uint64_t FinalAddress = Section.LoadAddress + Offset;
316 *Target = *Placeholder + Value + Addend - FinalAddress;
322 void RuntimeDyldELF::resolveX86Relocation(const SectionEntry &Section,
323 uint64_t Offset, uint32_t Value,
324 uint32_t Type, int32_t Addend) {
326 case ELF::R_386_32: {
327 // Get the placeholder value from the generated object since
328 // a previous relocation attempt may have overwritten the loaded version
329 uint32_t *Placeholder =
330 reinterpret_cast<uint32_t *>(Section.ObjAddress + Offset);
331 uint32_t *Target = reinterpret_cast<uint32_t *>(Section.Address + Offset);
332 *Target = *Placeholder + Value + Addend;
335 case ELF::R_386_PC32: {
336 // Get the placeholder value from the generated object since
337 // a previous relocation attempt may have overwritten the loaded version
338 uint32_t *Placeholder =
339 reinterpret_cast<uint32_t *>(Section.ObjAddress + Offset);
340 uint32_t *Target = reinterpret_cast<uint32_t *>(Section.Address + Offset);
341 uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
342 uint32_t RealOffset = *Placeholder + Value + Addend - FinalAddress;
343 *Target = RealOffset;
347 // There are other relocation types, but it appears these are the
348 // only ones currently used by the LLVM ELF object writer
349 llvm_unreachable("Relocation type not implemented yet!");
354 void RuntimeDyldELF::resolveAArch64Relocation(const SectionEntry &Section,
355 uint64_t Offset, uint64_t Value,
356 uint32_t Type, int64_t Addend) {
357 uint32_t *TargetPtr = reinterpret_cast<uint32_t *>(Section.Address + Offset);
358 uint64_t FinalAddress = Section.LoadAddress + Offset;
360 DEBUG(dbgs() << "resolveAArch64Relocation, LocalAddress: 0x"
361 << format("%llx", Section.Address + Offset)
362 << " FinalAddress: 0x" << format("%llx", FinalAddress)
363 << " Value: 0x" << format("%llx", Value) << " Type: 0x"
364 << format("%x", Type) << " Addend: 0x" << format("%llx", Addend)
369 llvm_unreachable("Relocation type not implemented yet!");
371 case ELF::R_AARCH64_ABS64: {
372 uint64_t *TargetPtr =
373 reinterpret_cast<uint64_t *>(Section.Address + Offset);
374 *TargetPtr = Value + Addend;
377 case ELF::R_AARCH64_PREL32: {
378 uint64_t Result = Value + Addend - FinalAddress;
379 assert(static_cast<int64_t>(Result) >= INT32_MIN &&
380 static_cast<int64_t>(Result) <= UINT32_MAX);
381 *TargetPtr = static_cast<uint32_t>(Result & 0xffffffffU);
384 case ELF::R_AARCH64_CALL26: // fallthrough
385 case ELF::R_AARCH64_JUMP26: {
386 // Operation: S+A-P. Set Call or B immediate value to bits fff_fffc of the
388 uint64_t BranchImm = Value + Addend - FinalAddress;
390 // "Check that -2^27 <= result < 2^27".
391 assert(-(1LL << 27) <= static_cast<int64_t>(BranchImm) &&
392 static_cast<int64_t>(BranchImm) < (1LL << 27));
394 // AArch64 code is emitted with .rela relocations. The data already in any
395 // bits affected by the relocation on entry is garbage.
396 *TargetPtr &= 0xfc000000U;
397 // Immediate goes in bits 25:0 of B and BL.
398 *TargetPtr |= static_cast<uint32_t>(BranchImm & 0xffffffcU) >> 2;
401 case ELF::R_AARCH64_MOVW_UABS_G3: {
402 uint64_t Result = Value + Addend;
404 // AArch64 code is emitted with .rela relocations. The data already in any
405 // bits affected by the relocation on entry is garbage.
406 *TargetPtr &= 0xffe0001fU;
407 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
408 *TargetPtr |= Result >> (48 - 5);
409 // Shift must be "lsl #48", in bits 22:21
410 assert((*TargetPtr >> 21 & 0x3) == 3 && "invalid shift for relocation");
413 case ELF::R_AARCH64_MOVW_UABS_G2_NC: {
414 uint64_t Result = Value + Addend;
416 // AArch64 code is emitted with .rela relocations. The data already in any
417 // bits affected by the relocation on entry is garbage.
418 *TargetPtr &= 0xffe0001fU;
419 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
420 *TargetPtr |= ((Result & 0xffff00000000ULL) >> (32 - 5));
421 // Shift must be "lsl #32", in bits 22:21
422 assert((*TargetPtr >> 21 & 0x3) == 2 && "invalid shift for relocation");
425 case ELF::R_AARCH64_MOVW_UABS_G1_NC: {
426 uint64_t Result = Value + Addend;
428 // AArch64 code is emitted with .rela relocations. The data already in any
429 // bits affected by the relocation on entry is garbage.
430 *TargetPtr &= 0xffe0001fU;
431 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
432 *TargetPtr |= ((Result & 0xffff0000U) >> (16 - 5));
433 // Shift must be "lsl #16", in bits 22:2
434 assert((*TargetPtr >> 21 & 0x3) == 1 && "invalid shift for relocation");
437 case ELF::R_AARCH64_MOVW_UABS_G0_NC: {
438 uint64_t Result = Value + Addend;
440 // AArch64 code is emitted with .rela relocations. The data already in any
441 // bits affected by the relocation on entry is garbage.
442 *TargetPtr &= 0xffe0001fU;
443 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
444 *TargetPtr |= ((Result & 0xffffU) << 5);
445 // Shift must be "lsl #0", in bits 22:21.
446 assert((*TargetPtr >> 21 & 0x3) == 0 && "invalid shift for relocation");
449 case ELF::R_AARCH64_ADR_PREL_PG_HI21: {
450 // Operation: Page(S+A) - Page(P)
452 ((Value + Addend) & ~0xfffULL) - (FinalAddress & ~0xfffULL);
454 // Check that -2^32 <= X < 2^32
455 assert(static_cast<int64_t>(Result) >= (-1LL << 32) &&
456 static_cast<int64_t>(Result) < (1LL << 32) &&
457 "overflow check failed for relocation");
459 // AArch64 code is emitted with .rela relocations. The data already in any
460 // bits affected by the relocation on entry is garbage.
461 *TargetPtr &= 0x9f00001fU;
462 // Immediate goes in bits 30:29 + 5:23 of ADRP instruction, taken
463 // from bits 32:12 of X.
464 *TargetPtr |= ((Result & 0x3000U) << (29 - 12));
465 *TargetPtr |= ((Result & 0x1ffffc000ULL) >> (14 - 5));
468 case ELF::R_AARCH64_LDST32_ABS_LO12_NC: {
470 uint64_t Result = Value + Addend;
472 // AArch64 code is emitted with .rela relocations. The data already in any
473 // bits affected by the relocation on entry is garbage.
474 *TargetPtr &= 0xffc003ffU;
475 // Immediate goes in bits 21:10 of LD/ST instruction, taken
476 // from bits 11:2 of X
477 *TargetPtr |= ((Result & 0xffc) << (10 - 2));
480 case ELF::R_AARCH64_LDST64_ABS_LO12_NC: {
482 uint64_t Result = Value + Addend;
484 // AArch64 code is emitted with .rela relocations. The data already in any
485 // bits affected by the relocation on entry is garbage.
486 *TargetPtr &= 0xffc003ffU;
487 // Immediate goes in bits 21:10 of LD/ST instruction, taken
488 // from bits 11:3 of X
489 *TargetPtr |= ((Result & 0xff8) << (10 - 3));
495 void RuntimeDyldELF::resolveARMRelocation(const SectionEntry &Section,
496 uint64_t Offset, uint32_t Value,
497 uint32_t Type, int32_t Addend) {
498 // TODO: Add Thumb relocations.
499 uint32_t *Placeholder =
500 reinterpret_cast<uint32_t *>(Section.ObjAddress + Offset);
501 uint32_t *TargetPtr = (uint32_t *)(Section.Address + Offset);
502 uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
505 DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: "
506 << Section.Address + Offset
507 << " FinalAddress: " << format("%p", FinalAddress) << " Value: "
508 << format("%x", Value) << " Type: " << format("%x", Type)
509 << " Addend: " << format("%x", Addend) << "\n");
513 llvm_unreachable("Not implemented relocation type!");
515 case ELF::R_ARM_NONE:
517 // Write a 32bit value to relocation address, taking into account the
518 // implicit addend encoded in the target.
519 case ELF::R_ARM_PREL31:
520 case ELF::R_ARM_TARGET1:
521 case ELF::R_ARM_ABS32:
522 *TargetPtr = *Placeholder + Value;
524 // Write first 16 bit of 32 bit value to the mov instruction.
525 // Last 4 bit should be shifted.
526 case ELF::R_ARM_MOVW_ABS_NC:
527 // We are not expecting any other addend in the relocation address.
528 // Using 0x000F0FFF because MOVW has its 16 bit immediate split into 2
529 // non-contiguous fields.
530 assert((*Placeholder & 0x000F0FFF) == 0);
531 Value = Value & 0xFFFF;
532 *TargetPtr = *Placeholder | (Value & 0xFFF);
533 *TargetPtr |= ((Value >> 12) & 0xF) << 16;
535 // Write last 16 bit of 32 bit value to the mov instruction.
536 // Last 4 bit should be shifted.
537 case ELF::R_ARM_MOVT_ABS:
538 // We are not expecting any other addend in the relocation address.
539 // Use 0x000F0FFF for the same reason as R_ARM_MOVW_ABS_NC.
540 assert((*Placeholder & 0x000F0FFF) == 0);
542 Value = (Value >> 16) & 0xFFFF;
543 *TargetPtr = *Placeholder | (Value & 0xFFF);
544 *TargetPtr |= ((Value >> 12) & 0xF) << 16;
546 // Write 24 bit relative value to the branch instruction.
547 case ELF::R_ARM_PC24: // Fall through.
548 case ELF::R_ARM_CALL: // Fall through.
549 case ELF::R_ARM_JUMP24: {
550 int32_t RelValue = static_cast<int32_t>(Value - FinalAddress - 8);
551 RelValue = (RelValue & 0x03FFFFFC) >> 2;
552 assert((*TargetPtr & 0xFFFFFF) == 0xFFFFFE);
553 *TargetPtr &= 0xFF000000;
554 *TargetPtr |= RelValue;
557 case ELF::R_ARM_PRIVATE_0:
558 // This relocation is reserved by the ARM ELF ABI for internal use. We
559 // appropriate it here to act as an R_ARM_ABS32 without any addend for use
560 // in the stubs created during JIT (which can't put an addend into the
561 // original object file).
567 void RuntimeDyldELF::resolveMIPSRelocation(const SectionEntry &Section,
568 uint64_t Offset, uint32_t Value,
569 uint32_t Type, int32_t Addend) {
570 uint32_t *Placeholder =
571 reinterpret_cast<uint32_t *>(Section.ObjAddress + Offset);
572 uint32_t *TargetPtr = (uint32_t *)(Section.Address + Offset);
575 DEBUG(dbgs() << "resolveMipselocation, LocalAddress: "
576 << Section.Address + Offset << " FinalAddress: "
577 << format("%p", Section.LoadAddress + Offset) << " Value: "
578 << format("%x", Value) << " Type: " << format("%x", Type)
579 << " Addend: " << format("%x", Addend) << "\n");
583 llvm_unreachable("Not implemented relocation type!");
586 *TargetPtr = Value + (*Placeholder);
589 *TargetPtr = ((*Placeholder) & 0xfc000000) | ((Value & 0x0fffffff) >> 2);
591 case ELF::R_MIPS_HI16:
592 // Get the higher 16-bits. Also add 1 if bit 15 is 1.
593 Value += ((*Placeholder) & 0x0000ffff) << 16;
595 ((*Placeholder) & 0xffff0000) | (((Value + 0x8000) >> 16) & 0xffff);
597 case ELF::R_MIPS_LO16:
598 Value += ((*Placeholder) & 0x0000ffff);
599 *TargetPtr = ((*Placeholder) & 0xffff0000) | (Value & 0xffff);
601 case ELF::R_MIPS_UNUSED1:
602 // Similar to ELF::R_ARM_PRIVATE_0, R_MIPS_UNUSED1 and R_MIPS_UNUSED2
603 // are used for internal JIT purpose. These relocations are similar to
604 // R_MIPS_HI16 and R_MIPS_LO16, but they do not take any addend into
607 ((*TargetPtr) & 0xffff0000) | (((Value + 0x8000) >> 16) & 0xffff);
609 case ELF::R_MIPS_UNUSED2:
610 *TargetPtr = ((*TargetPtr) & 0xffff0000) | (Value & 0xffff);
615 // Return the .TOC. section address to R_PPC64_TOC relocations.
616 uint64_t RuntimeDyldELF::findPPC64TOC() const {
617 // The TOC consists of sections .got, .toc, .tocbss, .plt in that
618 // order. The TOC starts where the first of these sections starts.
619 SectionList::const_iterator it = Sections.begin();
620 SectionList::const_iterator ite = Sections.end();
621 for (; it != ite; ++it) {
622 if (it->Name == ".got" || it->Name == ".toc" || it->Name == ".tocbss" ||
627 // This may happen for
628 // * references to TOC base base (sym@toc, .odp relocation) without
630 // In this case just use the first section (which is usually
631 // the .odp) since the code won't reference the .toc base
633 it = Sections.begin();
636 // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000
637 // thus permitting a full 64 Kbytes segment.
638 return it->LoadAddress + 0x8000;
641 // Returns the sections and offset associated with the ODP entry referenced
643 void RuntimeDyldELF::findOPDEntrySection(ObjectImage &Obj,
644 ObjSectionToIDMap &LocalSections,
645 RelocationValueRef &Rel) {
646 // Get the ELF symbol value (st_value) to compare with Relocation offset in
648 for (section_iterator si = Obj.begin_sections(), se = Obj.end_sections();
650 section_iterator RelSecI = si->getRelocatedSection();
651 if (RelSecI == Obj.end_sections())
654 StringRef RelSectionName;
655 check(RelSecI->getName(RelSectionName));
656 if (RelSectionName != ".opd")
659 for (relocation_iterator i = si->relocation_begin(),
660 e = si->relocation_end();
662 // The R_PPC64_ADDR64 relocation indicates the first field
665 check(i->getType(TypeFunc));
666 if (TypeFunc != ELF::R_PPC64_ADDR64) {
671 uint64_t TargetSymbolOffset;
672 symbol_iterator TargetSymbol = i->getSymbol();
673 check(i->getOffset(TargetSymbolOffset));
675 check(getELFRelocationAddend(*i, Addend));
681 // Just check if following relocation is a R_PPC64_TOC
683 check(i->getType(TypeTOC));
684 if (TypeTOC != ELF::R_PPC64_TOC)
687 // Finally compares the Symbol value and the target symbol offset
688 // to check if this .opd entry refers to the symbol the relocation
690 if (Rel.Addend != (int64_t)TargetSymbolOffset)
693 section_iterator tsi(Obj.end_sections());
694 check(TargetSymbol->getSection(tsi));
697 Rel.SectionID = findOrEmitSection(Obj, (*tsi), IsCode, LocalSections);
698 Rel.Addend = (intptr_t)Addend;
702 llvm_unreachable("Attempting to get address of ODP entry!");
705 // Relocation masks following the #lo(value), #hi(value), #ha(value),
706 // #higher(value), #highera(value), #highest(value), and #highesta(value)
707 // macros defined in section 4.5.1. Relocation Types of the PPC-elf64abi
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 applyPPCha (uint64_t value) {
717 return ((value + 0x8000) >> 16) & 0xffff;
720 static inline uint16_t applyPPChigher(uint64_t value) {
721 return (value >> 32) & 0xffff;
724 static inline uint16_t applyPPChighera (uint64_t value) {
725 return ((value + 0x8000) >> 32) & 0xffff;
728 static inline uint16_t applyPPChighest(uint64_t value) {
729 return (value >> 48) & 0xffff;
732 static inline uint16_t applyPPChighesta (uint64_t value) {
733 return ((value + 0x8000) >> 48) & 0xffff;
736 void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section,
737 uint64_t Offset, uint64_t Value,
738 uint32_t Type, int64_t Addend) {
739 uint8_t *LocalAddress = Section.Address + Offset;
742 llvm_unreachable("Relocation type not implemented yet!");
744 case ELF::R_PPC64_ADDR16:
745 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
747 case ELF::R_PPC64_ADDR16_DS:
748 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
750 case ELF::R_PPC64_ADDR16_LO:
751 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
753 case ELF::R_PPC64_ADDR16_LO_DS:
754 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
756 case ELF::R_PPC64_ADDR16_HI:
757 writeInt16BE(LocalAddress, applyPPChi(Value + Addend));
759 case ELF::R_PPC64_ADDR16_HA:
760 writeInt16BE(LocalAddress, applyPPCha(Value + Addend));
762 case ELF::R_PPC64_ADDR16_HIGHER:
763 writeInt16BE(LocalAddress, applyPPChigher(Value + Addend));
765 case ELF::R_PPC64_ADDR16_HIGHERA:
766 writeInt16BE(LocalAddress, applyPPChighera(Value + Addend));
768 case ELF::R_PPC64_ADDR16_HIGHEST:
769 writeInt16BE(LocalAddress, applyPPChighest(Value + Addend));
771 case ELF::R_PPC64_ADDR16_HIGHESTA:
772 writeInt16BE(LocalAddress, applyPPChighesta(Value + Addend));
774 case ELF::R_PPC64_ADDR14: {
775 assert(((Value + Addend) & 3) == 0);
776 // Preserve the AA/LK bits in the branch instruction
777 uint8_t aalk = *(LocalAddress + 3);
778 writeInt16BE(LocalAddress + 2, (aalk & 3) | ((Value + Addend) & 0xfffc));
780 case ELF::R_PPC64_REL16_LO: {
781 uint64_t FinalAddress = (Section.LoadAddress + Offset);
782 uint64_t Delta = Value - FinalAddress + Addend;
783 writeInt16BE(LocalAddress, applyPPClo(Delta));
785 case ELF::R_PPC64_REL16_HI: {
786 uint64_t FinalAddress = (Section.LoadAddress + Offset);
787 uint64_t Delta = Value - FinalAddress + Addend;
788 writeInt16BE(LocalAddress, applyPPChi(Delta));
790 case ELF::R_PPC64_REL16_HA: {
791 uint64_t FinalAddress = (Section.LoadAddress + Offset);
792 uint64_t Delta = Value - FinalAddress + Addend;
793 writeInt16BE(LocalAddress, applyPPCha(Delta));
795 case ELF::R_PPC64_ADDR32: {
796 int32_t Result = static_cast<int32_t>(Value + Addend);
797 if (SignExtend32<32>(Result) != Result)
798 llvm_unreachable("Relocation R_PPC64_ADDR32 overflow");
799 writeInt32BE(LocalAddress, Result);
801 case ELF::R_PPC64_REL24: {
802 uint64_t FinalAddress = (Section.LoadAddress + Offset);
803 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
804 if (SignExtend32<24>(delta) != delta)
805 llvm_unreachable("Relocation R_PPC64_REL24 overflow");
806 // Generates a 'bl <address>' instruction
807 writeInt32BE(LocalAddress, 0x48000001 | (delta & 0x03FFFFFC));
809 case ELF::R_PPC64_REL32: {
810 uint64_t FinalAddress = (Section.LoadAddress + Offset);
811 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
812 if (SignExtend32<32>(delta) != delta)
813 llvm_unreachable("Relocation R_PPC64_REL32 overflow");
814 writeInt32BE(LocalAddress, delta);
816 case ELF::R_PPC64_REL64: {
817 uint64_t FinalAddress = (Section.LoadAddress + Offset);
818 uint64_t Delta = Value - FinalAddress + Addend;
819 writeInt64BE(LocalAddress, Delta);
821 case ELF::R_PPC64_ADDR64:
822 writeInt64BE(LocalAddress, Value + Addend);
824 case ELF::R_PPC64_TOC:
825 writeInt64BE(LocalAddress, findPPC64TOC());
827 case ELF::R_PPC64_TOC16: {
828 uint64_t TOCStart = findPPC64TOC();
829 Value = applyPPClo((Value + Addend) - TOCStart);
830 writeInt16BE(LocalAddress, applyPPClo(Value));
832 case ELF::R_PPC64_TOC16_DS: {
833 uint64_t TOCStart = findPPC64TOC();
834 Value = ((Value + Addend) - TOCStart);
835 writeInt16BE(LocalAddress, applyPPClo(Value) & ~3);
837 case ELF::R_PPC64_TOC16_LO: {
838 uint64_t TOCStart = findPPC64TOC();
839 Value = ((Value + Addend) - TOCStart);
840 writeInt16BE(LocalAddress, applyPPClo(Value));
842 case ELF::R_PPC64_TOC16_LO_DS: {
843 uint64_t TOCStart = findPPC64TOC();
844 Value = ((Value + Addend) - TOCStart);
845 writeInt16BE(LocalAddress, applyPPClo(Value) & ~3);
847 case ELF::R_PPC64_TOC16_HI: {
848 uint64_t TOCStart = findPPC64TOC();
849 Value = ((Value + Addend) - TOCStart);
850 writeInt16BE(LocalAddress, applyPPChi(Value));
852 case ELF::R_PPC64_TOC16_HA: {
853 uint64_t TOCStart = findPPC64TOC();
854 Value = ((Value + Addend) - TOCStart);
855 writeInt16BE(LocalAddress, applyPPCha(Value));
860 void RuntimeDyldELF::resolveSystemZRelocation(const SectionEntry &Section,
861 uint64_t Offset, uint64_t Value,
862 uint32_t Type, int64_t Addend) {
863 uint8_t *LocalAddress = Section.Address + Offset;
866 llvm_unreachable("Relocation type not implemented yet!");
868 case ELF::R_390_PC16DBL:
869 case ELF::R_390_PLT16DBL: {
870 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
871 assert(int16_t(Delta / 2) * 2 == Delta && "R_390_PC16DBL overflow");
872 writeInt16BE(LocalAddress, Delta / 2);
875 case ELF::R_390_PC32DBL:
876 case ELF::R_390_PLT32DBL: {
877 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
878 assert(int32_t(Delta / 2) * 2 == Delta && "R_390_PC32DBL overflow");
879 writeInt32BE(LocalAddress, Delta / 2);
882 case ELF::R_390_PC32: {
883 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
884 assert(int32_t(Delta) == Delta && "R_390_PC32 overflow");
885 writeInt32BE(LocalAddress, Delta);
889 writeInt64BE(LocalAddress, Value + Addend);
894 // The target location for the relocation is described by RE.SectionID and
895 // RE.Offset. RE.SectionID can be used to find the SectionEntry. Each
896 // SectionEntry has three members describing its location.
897 // SectionEntry::Address is the address at which the section has been loaded
898 // into memory in the current (host) process. SectionEntry::LoadAddress is the
899 // address that the section will have in the target process.
900 // SectionEntry::ObjAddress is the address of the bits for this section in the
901 // original emitted object image (also in the current address space).
903 // Relocations will be applied as if the section were loaded at
904 // SectionEntry::LoadAddress, but they will be applied at an address based
905 // on SectionEntry::Address. SectionEntry::ObjAddress will be used to refer to
906 // Target memory contents if they are required for value calculations.
908 // The Value parameter here is the load address of the symbol for the
909 // relocation to be applied. For relocations which refer to symbols in the
910 // current object Value will be the LoadAddress of the section in which
911 // the symbol resides (RE.Addend provides additional information about the
912 // symbol location). For external symbols, Value will be the address of the
913 // symbol in the target address space.
914 void RuntimeDyldELF::resolveRelocation(const RelocationEntry &RE,
916 const SectionEntry &Section = Sections[RE.SectionID];
917 return resolveRelocation(Section, RE.Offset, Value, RE.RelType, RE.Addend,
921 void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section,
922 uint64_t Offset, uint64_t Value,
923 uint32_t Type, int64_t Addend,
924 uint64_t SymOffset) {
927 resolveX86_64Relocation(Section, Offset, Value, Type, Addend, SymOffset);
930 resolveX86Relocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
931 (uint32_t)(Addend & 0xffffffffL));
933 case Triple::aarch64:
934 case Triple::aarch64_be:
936 case Triple::arm64_be:
937 resolveAArch64Relocation(Section, Offset, Value, Type, Addend);
939 case Triple::arm: // Fall through.
942 case Triple::thumbeb:
943 resolveARMRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
944 (uint32_t)(Addend & 0xffffffffL));
946 case Triple::mips: // Fall through.
948 resolveMIPSRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL),
949 Type, (uint32_t)(Addend & 0xffffffffL));
951 case Triple::ppc64: // Fall through.
952 case Triple::ppc64le:
953 resolvePPC64Relocation(Section, Offset, Value, Type, Addend);
955 case Triple::systemz:
956 resolveSystemZRelocation(Section, Offset, Value, Type, Addend);
959 llvm_unreachable("Unsupported CPU type!");
963 relocation_iterator RuntimeDyldELF::processRelocationRef(
964 unsigned SectionID, relocation_iterator RelI, ObjectImage &Obj,
965 ObjSectionToIDMap &ObjSectionToID, const SymbolTableMap &Symbols,
968 Check(RelI->getType(RelType));
970 Check(getELFRelocationAddend(*RelI, Addend));
971 symbol_iterator Symbol = RelI->getSymbol();
973 // Obtain the symbol name which is referenced in the relocation
974 StringRef TargetName;
975 if (Symbol != Obj.end_symbols())
976 Symbol->getName(TargetName);
977 DEBUG(dbgs() << "\t\tRelType: " << RelType << " Addend: " << Addend
978 << " TargetName: " << TargetName << "\n");
979 RelocationValueRef Value;
980 // First search for the symbol in the local symbol table
981 SymbolTableMap::const_iterator lsi = Symbols.end();
982 SymbolRef::Type SymType = SymbolRef::ST_Unknown;
983 if (Symbol != Obj.end_symbols()) {
984 lsi = Symbols.find(TargetName.data());
985 Symbol->getType(SymType);
987 if (lsi != Symbols.end()) {
988 Value.SectionID = lsi->second.first;
989 Value.Offset = lsi->second.second;
990 Value.Addend = lsi->second.second + Addend;
992 // Search for the symbol in the global symbol table
993 SymbolTableMap::const_iterator gsi = GlobalSymbolTable.end();
994 if (Symbol != Obj.end_symbols())
995 gsi = GlobalSymbolTable.find(TargetName.data());
996 if (gsi != GlobalSymbolTable.end()) {
997 Value.SectionID = gsi->second.first;
998 Value.Offset = gsi->second.second;
999 Value.Addend = gsi->second.second + Addend;
1002 case SymbolRef::ST_Debug: {
1003 // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously
1004 // and can be changed by another developers. Maybe best way is add
1005 // a new symbol type ST_Section to SymbolRef and use it.
1006 section_iterator si(Obj.end_sections());
1007 Symbol->getSection(si);
1008 if (si == Obj.end_sections())
1009 llvm_unreachable("Symbol section not found, bad object file format!");
1010 DEBUG(dbgs() << "\t\tThis is section symbol\n");
1011 // Default to 'true' in case isText fails (though it never does).
1014 Value.SectionID = findOrEmitSection(Obj, (*si), isCode, ObjSectionToID);
1015 Value.Addend = Addend;
1018 case SymbolRef::ST_Data:
1019 case SymbolRef::ST_Unknown: {
1020 Value.SymbolName = TargetName.data();
1021 Value.Addend = Addend;
1023 // Absolute relocations will have a zero symbol ID (STN_UNDEF), which
1024 // will manifest here as a NULL symbol name.
1025 // We can set this as a valid (but empty) symbol name, and rely
1026 // on addRelocationForSymbol to handle this.
1027 if (!Value.SymbolName)
1028 Value.SymbolName = "";
1032 llvm_unreachable("Unresolved symbol type!");
1038 Check(RelI->getOffset(Offset));
1040 DEBUG(dbgs() << "\t\tSectionID: " << SectionID << " Offset: " << Offset
1042 if ((Arch == Triple::aarch64 || Arch == Triple::aarch64_be ||
1043 Arch == Triple::arm64 || Arch == Triple::arm64_be) &&
1044 (RelType == ELF::R_AARCH64_CALL26 || RelType == ELF::R_AARCH64_JUMP26)) {
1045 // This is an AArch64 branch relocation, need to use a stub function.
1046 DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation.");
1047 SectionEntry &Section = Sections[SectionID];
1049 // Look for an existing stub.
1050 StubMap::const_iterator i = Stubs.find(Value);
1051 if (i != Stubs.end()) {
1052 resolveRelocation(Section, Offset, (uint64_t)Section.Address + i->second,
1054 DEBUG(dbgs() << " Stub function found\n");
1056 // Create a new stub function.
1057 DEBUG(dbgs() << " Create a new stub function\n");
1058 Stubs[Value] = Section.StubOffset;
1059 uint8_t *StubTargetAddr =
1060 createStubFunction(Section.Address + Section.StubOffset);
1062 RelocationEntry REmovz_g3(SectionID, StubTargetAddr - Section.Address,
1063 ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend);
1064 RelocationEntry REmovk_g2(SectionID, StubTargetAddr - Section.Address + 4,
1065 ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend);
1066 RelocationEntry REmovk_g1(SectionID, StubTargetAddr - Section.Address + 8,
1067 ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend);
1068 RelocationEntry REmovk_g0(SectionID,
1069 StubTargetAddr - Section.Address + 12,
1070 ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend);
1072 if (Value.SymbolName) {
1073 addRelocationForSymbol(REmovz_g3, Value.SymbolName);
1074 addRelocationForSymbol(REmovk_g2, Value.SymbolName);
1075 addRelocationForSymbol(REmovk_g1, Value.SymbolName);
1076 addRelocationForSymbol(REmovk_g0, Value.SymbolName);
1078 addRelocationForSection(REmovz_g3, Value.SectionID);
1079 addRelocationForSection(REmovk_g2, Value.SectionID);
1080 addRelocationForSection(REmovk_g1, Value.SectionID);
1081 addRelocationForSection(REmovk_g0, Value.SectionID);
1083 resolveRelocation(Section, Offset,
1084 (uint64_t)Section.Address + Section.StubOffset, RelType,
1086 Section.StubOffset += getMaxStubSize();
1088 } else if (Arch == Triple::arm &&
1089 (RelType == ELF::R_ARM_PC24 || RelType == ELF::R_ARM_CALL ||
1090 RelType == ELF::R_ARM_JUMP24)) {
1091 // This is an ARM branch relocation, need to use a stub function.
1092 DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.");
1093 SectionEntry &Section = Sections[SectionID];
1095 // Look for an existing stub.
1096 StubMap::const_iterator i = Stubs.find(Value);
1097 if (i != Stubs.end()) {
1098 resolveRelocation(Section, Offset, (uint64_t)Section.Address + i->second,
1100 DEBUG(dbgs() << " Stub function found\n");
1102 // Create a new stub function.
1103 DEBUG(dbgs() << " Create a new stub function\n");
1104 Stubs[Value] = Section.StubOffset;
1105 uint8_t *StubTargetAddr =
1106 createStubFunction(Section.Address + Section.StubOffset);
1107 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1108 ELF::R_ARM_PRIVATE_0, Value.Addend);
1109 if (Value.SymbolName)
1110 addRelocationForSymbol(RE, Value.SymbolName);
1112 addRelocationForSection(RE, Value.SectionID);
1114 resolveRelocation(Section, Offset,
1115 (uint64_t)Section.Address + Section.StubOffset, RelType,
1117 Section.StubOffset += getMaxStubSize();
1119 } else if ((Arch == Triple::mipsel || Arch == Triple::mips) &&
1120 RelType == ELF::R_MIPS_26) {
1121 // This is an Mips branch relocation, need to use a stub function.
1122 DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
1123 SectionEntry &Section = Sections[SectionID];
1124 uint8_t *Target = Section.Address + Offset;
1125 uint32_t *TargetAddress = (uint32_t *)Target;
1127 // Extract the addend from the instruction.
1128 uint32_t Addend = ((*TargetAddress) & 0x03ffffff) << 2;
1130 Value.Addend += Addend;
1132 // Look up for existing stub.
1133 StubMap::const_iterator i = Stubs.find(Value);
1134 if (i != Stubs.end()) {
1135 RelocationEntry RE(SectionID, Offset, RelType, i->second);
1136 addRelocationForSection(RE, SectionID);
1137 DEBUG(dbgs() << " Stub function found\n");
1139 // Create a new stub function.
1140 DEBUG(dbgs() << " Create a new stub function\n");
1141 Stubs[Value] = Section.StubOffset;
1142 uint8_t *StubTargetAddr =
1143 createStubFunction(Section.Address + Section.StubOffset);
1145 // Creating Hi and Lo relocations for the filled stub instructions.
1146 RelocationEntry REHi(SectionID, StubTargetAddr - Section.Address,
1147 ELF::R_MIPS_UNUSED1, Value.Addend);
1148 RelocationEntry RELo(SectionID, StubTargetAddr - Section.Address + 4,
1149 ELF::R_MIPS_UNUSED2, Value.Addend);
1151 if (Value.SymbolName) {
1152 addRelocationForSymbol(REHi, Value.SymbolName);
1153 addRelocationForSymbol(RELo, Value.SymbolName);
1155 addRelocationForSection(REHi, Value.SectionID);
1156 addRelocationForSection(RELo, Value.SectionID);
1159 RelocationEntry RE(SectionID, Offset, RelType, Section.StubOffset);
1160 addRelocationForSection(RE, SectionID);
1161 Section.StubOffset += getMaxStubSize();
1163 } else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) {
1164 if (RelType == ELF::R_PPC64_REL24) {
1165 // A PPC branch relocation will need a stub function if the target is
1166 // an external symbol (Symbol::ST_Unknown) or if the target address
1167 // is not within the signed 24-bits branch address.
1168 SectionEntry &Section = Sections[SectionID];
1169 uint8_t *Target = Section.Address + Offset;
1170 bool RangeOverflow = false;
1171 if (SymType != SymbolRef::ST_Unknown) {
1172 // A function call may points to the .opd entry, so the final symbol
1174 // in calculated based in the relocation values in .opd section.
1175 findOPDEntrySection(Obj, ObjSectionToID, Value);
1176 uint8_t *RelocTarget = Sections[Value.SectionID].Address + Value.Addend;
1177 int32_t delta = static_cast<int32_t>(Target - RelocTarget);
1178 // If it is within 24-bits branch range, just set the branch target
1179 if (SignExtend32<24>(delta) == delta) {
1180 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1181 if (Value.SymbolName)
1182 addRelocationForSymbol(RE, Value.SymbolName);
1184 addRelocationForSection(RE, Value.SectionID);
1186 RangeOverflow = true;
1189 if (SymType == SymbolRef::ST_Unknown || RangeOverflow == true) {
1190 // It is an external symbol (SymbolRef::ST_Unknown) or within a range
1191 // larger than 24-bits.
1192 StubMap::const_iterator i = Stubs.find(Value);
1193 if (i != Stubs.end()) {
1194 // Symbol function stub already created, just relocate to it
1195 resolveRelocation(Section, Offset,
1196 (uint64_t)Section.Address + i->second, RelType, 0);
1197 DEBUG(dbgs() << " Stub function found\n");
1199 // Create a new stub function.
1200 DEBUG(dbgs() << " Create a new stub function\n");
1201 Stubs[Value] = Section.StubOffset;
1202 uint8_t *StubTargetAddr =
1203 createStubFunction(Section.Address + Section.StubOffset);
1204 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1205 ELF::R_PPC64_ADDR64, Value.Addend);
1207 // Generates the 64-bits address loads as exemplified in section
1208 // 4.5.1 in PPC64 ELF ABI. Note that the relocations need to
1209 // apply to the low part of the instructions, so we have to update
1210 // the offset according to the target endianness.
1211 uint64_t StubRelocOffset = StubTargetAddr - Section.Address;
1212 if (!IsTargetLittleEndian)
1213 StubRelocOffset += 2;
1215 RelocationEntry REhst(SectionID, StubRelocOffset + 0,
1216 ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend);
1217 RelocationEntry REhr(SectionID, StubRelocOffset + 4,
1218 ELF::R_PPC64_ADDR16_HIGHER, Value.Addend);
1219 RelocationEntry REh(SectionID, StubRelocOffset + 12,
1220 ELF::R_PPC64_ADDR16_HI, Value.Addend);
1221 RelocationEntry REl(SectionID, StubRelocOffset + 16,
1222 ELF::R_PPC64_ADDR16_LO, Value.Addend);
1224 if (Value.SymbolName) {
1225 addRelocationForSymbol(REhst, Value.SymbolName);
1226 addRelocationForSymbol(REhr, Value.SymbolName);
1227 addRelocationForSymbol(REh, Value.SymbolName);
1228 addRelocationForSymbol(REl, Value.SymbolName);
1230 addRelocationForSection(REhst, Value.SectionID);
1231 addRelocationForSection(REhr, Value.SectionID);
1232 addRelocationForSection(REh, Value.SectionID);
1233 addRelocationForSection(REl, Value.SectionID);
1236 resolveRelocation(Section, Offset,
1237 (uint64_t)Section.Address + Section.StubOffset,
1239 Section.StubOffset += getMaxStubSize();
1241 if (SymType == SymbolRef::ST_Unknown)
1242 // Restore the TOC for external calls
1243 writeInt32BE(Target + 4, 0xE8410028); // ld r2,40(r1)
1246 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1247 // Extra check to avoid relocation againt empty symbols (usually
1248 // the R_PPC64_TOC).
1249 if (SymType != SymbolRef::ST_Unknown && TargetName.empty())
1250 Value.SymbolName = nullptr;
1252 if (Value.SymbolName)
1253 addRelocationForSymbol(RE, Value.SymbolName);
1255 addRelocationForSection(RE, Value.SectionID);
1257 } else if (Arch == Triple::systemz &&
1258 (RelType == ELF::R_390_PLT32DBL || RelType == ELF::R_390_GOTENT)) {
1259 // Create function stubs for both PLT and GOT references, regardless of
1260 // whether the GOT reference is to data or code. The stub contains the
1261 // full address of the symbol, as needed by GOT references, and the
1262 // executable part only adds an overhead of 8 bytes.
1264 // We could try to conserve space by allocating the code and data
1265 // parts of the stub separately. However, as things stand, we allocate
1266 // a stub for every relocation, so using a GOT in JIT code should be
1267 // no less space efficient than using an explicit constant pool.
1268 DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation.");
1269 SectionEntry &Section = Sections[SectionID];
1271 // Look for an existing stub.
1272 StubMap::const_iterator i = Stubs.find(Value);
1273 uintptr_t StubAddress;
1274 if (i != Stubs.end()) {
1275 StubAddress = uintptr_t(Section.Address) + i->second;
1276 DEBUG(dbgs() << " Stub function found\n");
1278 // Create a new stub function.
1279 DEBUG(dbgs() << " Create a new stub function\n");
1281 uintptr_t BaseAddress = uintptr_t(Section.Address);
1282 uintptr_t StubAlignment = getStubAlignment();
1283 StubAddress = (BaseAddress + Section.StubOffset + StubAlignment - 1) &
1285 unsigned StubOffset = StubAddress - BaseAddress;
1287 Stubs[Value] = StubOffset;
1288 createStubFunction((uint8_t *)StubAddress);
1289 RelocationEntry RE(SectionID, StubOffset + 8, ELF::R_390_64,
1290 Value.Addend - Addend);
1291 if (Value.SymbolName)
1292 addRelocationForSymbol(RE, Value.SymbolName);
1294 addRelocationForSection(RE, Value.SectionID);
1295 Section.StubOffset = StubOffset + getMaxStubSize();
1298 if (RelType == ELF::R_390_GOTENT)
1299 resolveRelocation(Section, Offset, StubAddress + 8, ELF::R_390_PC32DBL,
1302 resolveRelocation(Section, Offset, StubAddress, RelType, Addend);
1303 } else if (Arch == Triple::x86_64 && RelType == ELF::R_X86_64_PLT32) {
1304 // The way the PLT relocations normally work is that the linker allocates
1306 // PLT and this relocation makes a PC-relative call into the PLT. The PLT
1307 // entry will then jump to an address provided by the GOT. On first call,
1309 // GOT address will point back into PLT code that resolves the symbol. After
1310 // the first call, the GOT entry points to the actual function.
1312 // For local functions we're ignoring all of that here and just replacing
1313 // the PLT32 relocation type with PC32, which will translate the relocation
1314 // into a PC-relative call directly to the function. For external symbols we
1315 // can't be sure the function will be within 2^32 bytes of the call site, so
1316 // we need to create a stub, which calls into the GOT. This case is
1317 // equivalent to the usual PLT implementation except that we use the stub
1318 // mechanism in RuntimeDyld (which puts stubs at the end of the section)
1319 // rather than allocating a PLT section.
1320 if (Value.SymbolName) {
1321 // This is a call to an external function.
1322 // Look for an existing stub.
1323 SectionEntry &Section = Sections[SectionID];
1324 StubMap::const_iterator i = Stubs.find(Value);
1325 uintptr_t StubAddress;
1326 if (i != Stubs.end()) {
1327 StubAddress = uintptr_t(Section.Address) + i->second;
1328 DEBUG(dbgs() << " Stub function found\n");
1330 // Create a new stub function (equivalent to a PLT entry).
1331 DEBUG(dbgs() << " Create a new stub function\n");
1333 uintptr_t BaseAddress = uintptr_t(Section.Address);
1334 uintptr_t StubAlignment = getStubAlignment();
1335 StubAddress = (BaseAddress + Section.StubOffset + StubAlignment - 1) &
1337 unsigned StubOffset = StubAddress - BaseAddress;
1338 Stubs[Value] = StubOffset;
1339 createStubFunction((uint8_t *)StubAddress);
1341 // Create a GOT entry for the external function.
1342 GOTEntries.push_back(Value);
1344 // Make our stub function a relative call to the GOT entry.
1345 RelocationEntry RE(SectionID, StubOffset + 2, ELF::R_X86_64_GOTPCREL,
1347 addRelocationForSymbol(RE, Value.SymbolName);
1349 // Bump our stub offset counter
1350 Section.StubOffset = StubOffset + getMaxStubSize();
1353 // Make the target call a call into the stub table.
1354 resolveRelocation(Section, Offset, StubAddress, ELF::R_X86_64_PC32,
1357 RelocationEntry RE(SectionID, Offset, ELF::R_X86_64_PC32, Value.Addend,
1359 addRelocationForSection(RE, Value.SectionID);
1362 if (Arch == Triple::x86_64 && RelType == ELF::R_X86_64_GOTPCREL) {
1363 GOTEntries.push_back(Value);
1365 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend, Value.Offset);
1366 if (Value.SymbolName)
1367 addRelocationForSymbol(RE, Value.SymbolName);
1369 addRelocationForSection(RE, Value.SectionID);
1374 void RuntimeDyldELF::updateGOTEntries(StringRef Name, uint64_t Addr) {
1376 SmallVectorImpl<std::pair<SID, GOTRelocations>>::iterator it;
1377 SmallVectorImpl<std::pair<SID, GOTRelocations>>::iterator end = GOTs.end();
1379 for (it = GOTs.begin(); it != end; ++it) {
1380 GOTRelocations &GOTEntries = it->second;
1381 for (int i = 0, e = GOTEntries.size(); i != e; ++i) {
1382 if (GOTEntries[i].SymbolName != nullptr &&
1383 GOTEntries[i].SymbolName == Name) {
1384 GOTEntries[i].Offset = Addr;
1390 size_t RuntimeDyldELF::getGOTEntrySize() {
1391 // We don't use the GOT in all of these cases, but it's essentially free
1392 // to put them all here.
1395 case Triple::x86_64:
1396 case Triple::aarch64:
1397 case Triple::aarch64_be:
1399 case Triple::arm64_be:
1401 case Triple::ppc64le:
1402 case Triple::systemz:
1403 Result = sizeof(uint64_t);
1409 case Triple::mipsel:
1410 Result = sizeof(uint32_t);
1413 llvm_unreachable("Unsupported CPU type!");
1418 uint64_t RuntimeDyldELF::findGOTEntry(uint64_t LoadAddress, uint64_t Offset) {
1420 const size_t GOTEntrySize = getGOTEntrySize();
1422 SmallVectorImpl<std::pair<SID, GOTRelocations>>::const_iterator it;
1423 SmallVectorImpl<std::pair<SID, GOTRelocations>>::const_iterator end =
1427 for (it = GOTs.begin(); it != end; ++it) {
1428 SID GOTSectionID = it->first;
1429 const GOTRelocations &GOTEntries = it->second;
1431 // Find the matching entry in our vector.
1432 uint64_t SymbolOffset = 0;
1433 for (int i = 0, e = GOTEntries.size(); i != e; ++i) {
1434 if (!GOTEntries[i].SymbolName) {
1435 if (getSectionLoadAddress(GOTEntries[i].SectionID) == LoadAddress &&
1436 GOTEntries[i].Offset == Offset) {
1438 SymbolOffset = GOTEntries[i].Offset;
1442 // GOT entries for external symbols use the addend as the address when
1443 // the external symbol has been resolved.
1444 if (GOTEntries[i].Offset == LoadAddress) {
1446 // Don't use the Addend here. The relocation handler will use it.
1452 if (GOTIndex != -1) {
1453 if (GOTEntrySize == sizeof(uint64_t)) {
1454 uint64_t *LocalGOTAddr = (uint64_t *)getSectionAddress(GOTSectionID);
1455 // Fill in this entry with the address of the symbol being referenced.
1456 LocalGOTAddr[GOTIndex] = LoadAddress + SymbolOffset;
1458 uint32_t *LocalGOTAddr = (uint32_t *)getSectionAddress(GOTSectionID);
1459 // Fill in this entry with the address of the symbol being referenced.
1460 LocalGOTAddr[GOTIndex] = (uint32_t)(LoadAddress + SymbolOffset);
1463 // Calculate the load address of this entry
1464 return getSectionLoadAddress(GOTSectionID) + (GOTIndex * GOTEntrySize);
1468 assert(GOTIndex != -1 && "Unable to find requested GOT entry.");
1472 void RuntimeDyldELF::finalizeLoad(ObjectImage &ObjImg,
1473 ObjSectionToIDMap &SectionMap) {
1474 // If necessary, allocate the global offset table
1476 // Allocate the GOT if necessary
1477 size_t numGOTEntries = GOTEntries.size();
1478 if (numGOTEntries != 0) {
1479 // Allocate memory for the section
1480 unsigned SectionID = Sections.size();
1481 size_t TotalSize = numGOTEntries * getGOTEntrySize();
1482 uint8_t *Addr = MemMgr->allocateDataSection(TotalSize, getGOTEntrySize(),
1483 SectionID, ".got", false);
1485 report_fatal_error("Unable to allocate memory for GOT!");
1487 GOTs.push_back(std::make_pair(SectionID, GOTEntries));
1488 Sections.push_back(SectionEntry(".got", Addr, TotalSize, 0));
1489 // For now, initialize all GOT entries to zero. We'll fill them in as
1490 // needed when GOT-based relocations are applied.
1491 memset(Addr, 0, TotalSize);
1494 report_fatal_error("Unable to allocate memory for GOT!");
1497 // Look for and record the EH frame section.
1498 ObjSectionToIDMap::iterator i, e;
1499 for (i = SectionMap.begin(), e = SectionMap.end(); i != e; ++i) {
1500 const SectionRef &Section = i->first;
1502 Section.getName(Name);
1503 if (Name == ".eh_frame") {
1504 UnregisteredEHFrameSections.push_back(i->second);
1510 bool RuntimeDyldELF::isCompatibleFormat(const ObjectBuffer *Buffer) const {
1511 if (Buffer->getBufferSize() < strlen(ELF::ElfMagic))
1513 return (memcmp(Buffer->getBufferStart(), ELF::ElfMagic,
1514 strlen(ELF::ElfMagic))) == 0;
1517 bool RuntimeDyldELF::isCompatibleFile(const object::ObjectFile *Obj) const {
1518 return Obj->isELF();