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 std::unique_ptr<MemoryBuffer> Wrapper, std::error_code &ec);
60 DyldELFObject(std::unique_ptr<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(std::unique_ptr<MemoryBuffer> Wrapper,
114 : ELFObjectFile<ELFT>(std::move(Wrapper), EC) {
115 this->isDyldELFObject = true;
118 template <class ELFT>
119 DyldELFObject<ELFT>::DyldELFObject(std::unique_ptr<ObjectFile> UnderlyingFile,
120 std::unique_ptr<MemoryBuffer> Wrapper,
122 : ELFObjectFile<ELFT>(std::move(Wrapper), EC),
123 UnderlyingFile(std::move(UnderlyingFile)) {
124 this->isDyldELFObject = true;
127 template <class ELFT>
128 void DyldELFObject<ELFT>::updateSectionAddress(const SectionRef &Sec,
130 DataRefImpl ShdrRef = Sec.getRawDataRefImpl();
132 const_cast<Elf_Shdr *>(reinterpret_cast<const Elf_Shdr *>(ShdrRef.p));
134 // This assumes the address passed in matches the target address bitness
135 // The template-based type cast handles everything else.
136 shdr->sh_addr = static_cast<addr_type>(Addr);
139 template <class ELFT>
140 void DyldELFObject<ELFT>::updateSymbolAddress(const SymbolRef &SymRef,
143 Elf_Sym *sym = const_cast<Elf_Sym *>(
144 ELFObjectFile<ELFT>::getSymbol(SymRef.getRawDataRefImpl()));
146 // This assumes the address passed in matches the target address bitness
147 // The template-based type cast handles everything else.
148 sym->st_value = static_cast<addr_type>(Addr);
155 void RuntimeDyldELF::registerEHFrames() {
158 for (int i = 0, e = UnregisteredEHFrameSections.size(); i != e; ++i) {
159 SID EHFrameSID = UnregisteredEHFrameSections[i];
160 uint8_t *EHFrameAddr = Sections[EHFrameSID].Address;
161 uint64_t EHFrameLoadAddr = Sections[EHFrameSID].LoadAddress;
162 size_t EHFrameSize = Sections[EHFrameSID].Size;
163 MemMgr->registerEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
164 RegisteredEHFrameSections.push_back(EHFrameSID);
166 UnregisteredEHFrameSections.clear();
169 void RuntimeDyldELF::deregisterEHFrames() {
172 for (int i = 0, e = RegisteredEHFrameSections.size(); i != e; ++i) {
173 SID EHFrameSID = RegisteredEHFrameSections[i];
174 uint8_t *EHFrameAddr = Sections[EHFrameSID].Address;
175 uint64_t EHFrameLoadAddr = Sections[EHFrameSID].LoadAddress;
176 size_t EHFrameSize = Sections[EHFrameSID].Size;
177 MemMgr->deregisterEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
179 RegisteredEHFrameSections.clear();
183 RuntimeDyldELF::createObjectImageFromFile(std::unique_ptr<object::ObjectFile> ObjFile) {
188 std::unique_ptr<MemoryBuffer> Buffer(
189 MemoryBuffer::getMemBuffer(ObjFile->getData(), "", false));
191 if (ObjFile->getBytesInAddress() == 4 && ObjFile->isLittleEndian()) {
193 llvm::make_unique<DyldELFObject<ELFType<support::little, 2, false>>>(
194 std::move(ObjFile), std::move(Buffer), ec);
195 return new ELFObjectImage<ELFType<support::little, 2, false>>(
196 nullptr, std::move(Obj));
197 } else if (ObjFile->getBytesInAddress() == 4 && !ObjFile->isLittleEndian()) {
199 llvm::make_unique<DyldELFObject<ELFType<support::big, 2, false>>>(
200 std::move(ObjFile), std::move(Buffer), ec);
201 return new ELFObjectImage<ELFType<support::big, 2, false>>(nullptr, std::move(Obj));
202 } else if (ObjFile->getBytesInAddress() == 8 && !ObjFile->isLittleEndian()) {
203 auto Obj = llvm::make_unique<DyldELFObject<ELFType<support::big, 2, true>>>(
204 std::move(ObjFile), std::move(Buffer), ec);
205 return new ELFObjectImage<ELFType<support::big, 2, true>>(nullptr,
207 } else if (ObjFile->getBytesInAddress() == 8 && ObjFile->isLittleEndian()) {
209 llvm::make_unique<DyldELFObject<ELFType<support::little, 2, true>>>(
210 std::move(ObjFile), std::move(Buffer), ec);
211 return new ELFObjectImage<ELFType<support::little, 2, true>>(
212 nullptr, std::move(Obj));
214 llvm_unreachable("Unexpected ELF format");
217 ObjectImage *RuntimeDyldELF::createObjectImage(ObjectBuffer *Buffer) {
218 if (Buffer->getBufferSize() < ELF::EI_NIDENT)
219 llvm_unreachable("Unexpected ELF object size");
220 std::pair<unsigned char, unsigned char> Ident =
221 std::make_pair((uint8_t)Buffer->getBufferStart()[ELF::EI_CLASS],
222 (uint8_t)Buffer->getBufferStart()[ELF::EI_DATA]);
225 std::unique_ptr<MemoryBuffer> Buf(Buffer->getMemBuffer());
227 if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2LSB) {
229 llvm::make_unique<DyldELFObject<ELFType<support::little, 4, false>>>(
231 return new ELFObjectImage<ELFType<support::little, 4, false>>(
232 Buffer, std::move(Obj));
233 } else if (Ident.first == ELF::ELFCLASS32 &&
234 Ident.second == ELF::ELFDATA2MSB) {
236 llvm::make_unique<DyldELFObject<ELFType<support::big, 4, false>>>(
238 return new ELFObjectImage<ELFType<support::big, 4, false>>(Buffer,
240 } else if (Ident.first == ELF::ELFCLASS64 &&
241 Ident.second == ELF::ELFDATA2MSB) {
242 auto Obj = llvm::make_unique<DyldELFObject<ELFType<support::big, 8, true>>>(
244 return new ELFObjectImage<ELFType<support::big, 8, true>>(Buffer, std::move(Obj));
245 } else if (Ident.first == ELF::ELFCLASS64 &&
246 Ident.second == ELF::ELFDATA2LSB) {
248 llvm::make_unique<DyldELFObject<ELFType<support::little, 8, true>>>(
250 return new ELFObjectImage<ELFType<support::little, 8, true>>(Buffer, std::move(Obj));
252 llvm_unreachable("Unexpected ELF format");
255 RuntimeDyldELF::~RuntimeDyldELF() {}
257 void RuntimeDyldELF::resolveX86_64Relocation(const SectionEntry &Section,
258 uint64_t Offset, uint64_t Value,
259 uint32_t Type, int64_t Addend,
260 uint64_t SymOffset) {
263 llvm_unreachable("Relocation type not implemented yet!");
265 case ELF::R_X86_64_64: {
266 uint64_t *Target = reinterpret_cast<uint64_t *>(Section.Address + Offset);
267 *Target = Value + Addend;
268 DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend)) << " at "
269 << format("%p\n", Target));
272 case ELF::R_X86_64_32:
273 case ELF::R_X86_64_32S: {
275 assert((Type == ELF::R_X86_64_32 && (Value <= UINT32_MAX)) ||
276 (Type == ELF::R_X86_64_32S &&
277 ((int64_t)Value <= INT32_MAX && (int64_t)Value >= INT32_MIN)));
278 uint32_t TruncatedAddr = (Value & 0xFFFFFFFF);
279 uint32_t *Target = reinterpret_cast<uint32_t *>(Section.Address + Offset);
280 *Target = TruncatedAddr;
281 DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr) << " at "
282 << format("%p\n", Target));
285 case ELF::R_X86_64_GOTPCREL: {
286 // findGOTEntry returns the 'G + GOT' part of the relocation calculation
287 // based on the load/target address of the GOT (not the current/local addr).
288 uint64_t GOTAddr = findGOTEntry(Value, SymOffset);
289 uint32_t *Target = reinterpret_cast<uint32_t *>(Section.Address + Offset);
290 uint64_t FinalAddress = Section.LoadAddress + Offset;
291 // The processRelocationRef method combines the symbol offset and the addend
292 // and in most cases that's what we want. For this relocation type, we need
293 // the raw addend, so we subtract the symbol offset to get it.
294 int64_t RealOffset = GOTAddr + Addend - SymOffset - FinalAddress;
295 assert(RealOffset <= INT32_MAX && RealOffset >= INT32_MIN);
296 int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
297 *Target = TruncOffset;
300 case ELF::R_X86_64_PC32: {
301 // Get the placeholder value from the generated object since
302 // a previous relocation attempt may have overwritten the loaded version
303 uint32_t *Placeholder =
304 reinterpret_cast<uint32_t *>(Section.ObjAddress + Offset);
305 uint32_t *Target = reinterpret_cast<uint32_t *>(Section.Address + Offset);
306 uint64_t FinalAddress = Section.LoadAddress + Offset;
307 int64_t RealOffset = *Placeholder + Value + Addend - FinalAddress;
308 assert(RealOffset <= INT32_MAX && RealOffset >= INT32_MIN);
309 int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
310 *Target = TruncOffset;
313 case ELF::R_X86_64_PC64: {
314 // Get the placeholder value from the generated object since
315 // a previous relocation attempt may have overwritten the loaded version
316 uint64_t *Placeholder =
317 reinterpret_cast<uint64_t *>(Section.ObjAddress + Offset);
318 uint64_t *Target = reinterpret_cast<uint64_t *>(Section.Address + Offset);
319 uint64_t FinalAddress = Section.LoadAddress + Offset;
320 *Target = *Placeholder + Value + Addend - FinalAddress;
326 void RuntimeDyldELF::resolveX86Relocation(const SectionEntry &Section,
327 uint64_t Offset, uint32_t Value,
328 uint32_t Type, int32_t Addend) {
330 case ELF::R_386_32: {
331 // Get the placeholder value from the generated object since
332 // a previous relocation attempt may have overwritten the loaded version
333 uint32_t *Placeholder =
334 reinterpret_cast<uint32_t *>(Section.ObjAddress + Offset);
335 uint32_t *Target = reinterpret_cast<uint32_t *>(Section.Address + Offset);
336 *Target = *Placeholder + Value + Addend;
339 case ELF::R_386_PC32: {
340 // Get the placeholder value from the generated object since
341 // a previous relocation attempt may have overwritten the loaded version
342 uint32_t *Placeholder =
343 reinterpret_cast<uint32_t *>(Section.ObjAddress + Offset);
344 uint32_t *Target = reinterpret_cast<uint32_t *>(Section.Address + Offset);
345 uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
346 uint32_t RealOffset = *Placeholder + Value + Addend - FinalAddress;
347 *Target = RealOffset;
351 // There are other relocation types, but it appears these are the
352 // only ones currently used by the LLVM ELF object writer
353 llvm_unreachable("Relocation type not implemented yet!");
358 void RuntimeDyldELF::resolveAArch64Relocation(const SectionEntry &Section,
359 uint64_t Offset, uint64_t Value,
360 uint32_t Type, int64_t Addend) {
361 uint32_t *TargetPtr = reinterpret_cast<uint32_t *>(Section.Address + Offset);
362 uint64_t FinalAddress = Section.LoadAddress + Offset;
364 DEBUG(dbgs() << "resolveAArch64Relocation, LocalAddress: 0x"
365 << format("%llx", Section.Address + Offset)
366 << " FinalAddress: 0x" << format("%llx", FinalAddress)
367 << " Value: 0x" << format("%llx", Value) << " Type: 0x"
368 << format("%x", Type) << " Addend: 0x" << format("%llx", Addend)
373 llvm_unreachable("Relocation type not implemented yet!");
375 case ELF::R_AARCH64_ABS64: {
376 uint64_t *TargetPtr =
377 reinterpret_cast<uint64_t *>(Section.Address + Offset);
378 *TargetPtr = Value + Addend;
381 case ELF::R_AARCH64_PREL32: {
382 uint64_t Result = Value + Addend - FinalAddress;
383 assert(static_cast<int64_t>(Result) >= INT32_MIN &&
384 static_cast<int64_t>(Result) <= UINT32_MAX);
385 *TargetPtr = static_cast<uint32_t>(Result & 0xffffffffU);
388 case ELF::R_AARCH64_CALL26: // fallthrough
389 case ELF::R_AARCH64_JUMP26: {
390 // Operation: S+A-P. Set Call or B immediate value to bits fff_fffc of the
392 uint64_t BranchImm = Value + Addend - FinalAddress;
394 // "Check that -2^27 <= result < 2^27".
395 assert(-(1LL << 27) <= static_cast<int64_t>(BranchImm) &&
396 static_cast<int64_t>(BranchImm) < (1LL << 27));
398 // AArch64 code is emitted with .rela relocations. The data already in any
399 // bits affected by the relocation on entry is garbage.
400 *TargetPtr &= 0xfc000000U;
401 // Immediate goes in bits 25:0 of B and BL.
402 *TargetPtr |= static_cast<uint32_t>(BranchImm & 0xffffffcU) >> 2;
405 case ELF::R_AARCH64_MOVW_UABS_G3: {
406 uint64_t Result = Value + Addend;
408 // AArch64 code is emitted with .rela relocations. The data already in any
409 // bits affected by the relocation on entry is garbage.
410 *TargetPtr &= 0xffe0001fU;
411 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
412 *TargetPtr |= Result >> (48 - 5);
413 // Shift must be "lsl #48", in bits 22:21
414 assert((*TargetPtr >> 21 & 0x3) == 3 && "invalid shift for relocation");
417 case ELF::R_AARCH64_MOVW_UABS_G2_NC: {
418 uint64_t Result = Value + Addend;
420 // AArch64 code is emitted with .rela relocations. The data already in any
421 // bits affected by the relocation on entry is garbage.
422 *TargetPtr &= 0xffe0001fU;
423 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
424 *TargetPtr |= ((Result & 0xffff00000000ULL) >> (32 - 5));
425 // Shift must be "lsl #32", in bits 22:21
426 assert((*TargetPtr >> 21 & 0x3) == 2 && "invalid shift for relocation");
429 case ELF::R_AARCH64_MOVW_UABS_G1_NC: {
430 uint64_t Result = Value + Addend;
432 // AArch64 code is emitted with .rela relocations. The data already in any
433 // bits affected by the relocation on entry is garbage.
434 *TargetPtr &= 0xffe0001fU;
435 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
436 *TargetPtr |= ((Result & 0xffff0000U) >> (16 - 5));
437 // Shift must be "lsl #16", in bits 22:2
438 assert((*TargetPtr >> 21 & 0x3) == 1 && "invalid shift for relocation");
441 case ELF::R_AARCH64_MOVW_UABS_G0_NC: {
442 uint64_t Result = Value + Addend;
444 // AArch64 code is emitted with .rela relocations. The data already in any
445 // bits affected by the relocation on entry is garbage.
446 *TargetPtr &= 0xffe0001fU;
447 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
448 *TargetPtr |= ((Result & 0xffffU) << 5);
449 // Shift must be "lsl #0", in bits 22:21.
450 assert((*TargetPtr >> 21 & 0x3) == 0 && "invalid shift for relocation");
453 case ELF::R_AARCH64_ADR_PREL_PG_HI21: {
454 // Operation: Page(S+A) - Page(P)
456 ((Value + Addend) & ~0xfffULL) - (FinalAddress & ~0xfffULL);
458 // Check that -2^32 <= X < 2^32
459 assert(static_cast<int64_t>(Result) >= (-1LL << 32) &&
460 static_cast<int64_t>(Result) < (1LL << 32) &&
461 "overflow check failed for relocation");
463 // AArch64 code is emitted with .rela relocations. The data already in any
464 // bits affected by the relocation on entry is garbage.
465 *TargetPtr &= 0x9f00001fU;
466 // Immediate goes in bits 30:29 + 5:23 of ADRP instruction, taken
467 // from bits 32:12 of X.
468 *TargetPtr |= ((Result & 0x3000U) << (29 - 12));
469 *TargetPtr |= ((Result & 0x1ffffc000ULL) >> (14 - 5));
472 case ELF::R_AARCH64_LDST32_ABS_LO12_NC: {
474 uint64_t Result = Value + Addend;
476 // AArch64 code is emitted with .rela relocations. The data already in any
477 // bits affected by the relocation on entry is garbage.
478 *TargetPtr &= 0xffc003ffU;
479 // Immediate goes in bits 21:10 of LD/ST instruction, taken
480 // from bits 11:2 of X
481 *TargetPtr |= ((Result & 0xffc) << (10 - 2));
484 case ELF::R_AARCH64_LDST64_ABS_LO12_NC: {
486 uint64_t Result = Value + Addend;
488 // AArch64 code is emitted with .rela relocations. The data already in any
489 // bits affected by the relocation on entry is garbage.
490 *TargetPtr &= 0xffc003ffU;
491 // Immediate goes in bits 21:10 of LD/ST instruction, taken
492 // from bits 11:3 of X
493 *TargetPtr |= ((Result & 0xff8) << (10 - 3));
499 void RuntimeDyldELF::resolveARMRelocation(const SectionEntry &Section,
500 uint64_t Offset, uint32_t Value,
501 uint32_t Type, int32_t Addend) {
502 // TODO: Add Thumb relocations.
503 uint32_t *Placeholder =
504 reinterpret_cast<uint32_t *>(Section.ObjAddress + Offset);
505 uint32_t *TargetPtr = (uint32_t *)(Section.Address + Offset);
506 uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
509 DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: "
510 << Section.Address + Offset
511 << " FinalAddress: " << format("%p", FinalAddress) << " Value: "
512 << format("%x", Value) << " Type: " << format("%x", Type)
513 << " Addend: " << format("%x", Addend) << "\n");
517 llvm_unreachable("Not implemented relocation type!");
519 case ELF::R_ARM_NONE:
521 // Write a 32bit value to relocation address, taking into account the
522 // implicit addend encoded in the target.
523 case ELF::R_ARM_PREL31:
524 case ELF::R_ARM_TARGET1:
525 case ELF::R_ARM_ABS32:
526 *TargetPtr = *Placeholder + Value;
528 // Write first 16 bit of 32 bit value to the mov instruction.
529 // Last 4 bit should be shifted.
530 case ELF::R_ARM_MOVW_ABS_NC:
531 // We are not expecting any other addend in the relocation address.
532 // Using 0x000F0FFF because MOVW has its 16 bit immediate split into 2
533 // non-contiguous fields.
534 assert((*Placeholder & 0x000F0FFF) == 0);
535 Value = Value & 0xFFFF;
536 *TargetPtr = *Placeholder | (Value & 0xFFF);
537 *TargetPtr |= ((Value >> 12) & 0xF) << 16;
539 // Write last 16 bit of 32 bit value to the mov instruction.
540 // Last 4 bit should be shifted.
541 case ELF::R_ARM_MOVT_ABS:
542 // We are not expecting any other addend in the relocation address.
543 // Use 0x000F0FFF for the same reason as R_ARM_MOVW_ABS_NC.
544 assert((*Placeholder & 0x000F0FFF) == 0);
546 Value = (Value >> 16) & 0xFFFF;
547 *TargetPtr = *Placeholder | (Value & 0xFFF);
548 *TargetPtr |= ((Value >> 12) & 0xF) << 16;
550 // Write 24 bit relative value to the branch instruction.
551 case ELF::R_ARM_PC24: // Fall through.
552 case ELF::R_ARM_CALL: // Fall through.
553 case ELF::R_ARM_JUMP24: {
554 int32_t RelValue = static_cast<int32_t>(Value - FinalAddress - 8);
555 RelValue = (RelValue & 0x03FFFFFC) >> 2;
556 assert((*TargetPtr & 0xFFFFFF) == 0xFFFFFE);
557 *TargetPtr &= 0xFF000000;
558 *TargetPtr |= RelValue;
561 case ELF::R_ARM_PRIVATE_0:
562 // This relocation is reserved by the ARM ELF ABI for internal use. We
563 // appropriate it here to act as an R_ARM_ABS32 without any addend for use
564 // in the stubs created during JIT (which can't put an addend into the
565 // original object file).
571 void RuntimeDyldELF::resolveMIPSRelocation(const SectionEntry &Section,
572 uint64_t Offset, uint32_t Value,
573 uint32_t Type, int32_t Addend) {
574 uint32_t *Placeholder =
575 reinterpret_cast<uint32_t *>(Section.ObjAddress + Offset);
576 uint32_t *TargetPtr = (uint32_t *)(Section.Address + Offset);
579 DEBUG(dbgs() << "resolveMipselocation, LocalAddress: "
580 << Section.Address + Offset << " FinalAddress: "
581 << format("%p", Section.LoadAddress + Offset) << " Value: "
582 << format("%x", Value) << " Type: " << format("%x", Type)
583 << " Addend: " << format("%x", Addend) << "\n");
587 llvm_unreachable("Not implemented relocation type!");
590 *TargetPtr = Value + (*Placeholder);
593 *TargetPtr = ((*Placeholder) & 0xfc000000) | ((Value & 0x0fffffff) >> 2);
595 case ELF::R_MIPS_HI16:
596 // Get the higher 16-bits. Also add 1 if bit 15 is 1.
597 Value += ((*Placeholder) & 0x0000ffff) << 16;
599 ((*Placeholder) & 0xffff0000) | (((Value + 0x8000) >> 16) & 0xffff);
601 case ELF::R_MIPS_LO16:
602 Value += ((*Placeholder) & 0x0000ffff);
603 *TargetPtr = ((*Placeholder) & 0xffff0000) | (Value & 0xffff);
605 case ELF::R_MIPS_UNUSED1:
606 // Similar to ELF::R_ARM_PRIVATE_0, R_MIPS_UNUSED1 and R_MIPS_UNUSED2
607 // are used for internal JIT purpose. These relocations are similar to
608 // R_MIPS_HI16 and R_MIPS_LO16, but they do not take any addend into
611 ((*TargetPtr) & 0xffff0000) | (((Value + 0x8000) >> 16) & 0xffff);
613 case ELF::R_MIPS_UNUSED2:
614 *TargetPtr = ((*TargetPtr) & 0xffff0000) | (Value & 0xffff);
619 // Return the .TOC. section address to R_PPC64_TOC relocations.
620 uint64_t RuntimeDyldELF::findPPC64TOC() const {
621 // The TOC consists of sections .got, .toc, .tocbss, .plt in that
622 // order. The TOC starts where the first of these sections starts.
623 SectionList::const_iterator it = Sections.begin();
624 SectionList::const_iterator ite = Sections.end();
625 for (; it != ite; ++it) {
626 if (it->Name == ".got" || it->Name == ".toc" || it->Name == ".tocbss" ||
631 // This may happen for
632 // * references to TOC base base (sym@toc, .odp relocation) without
634 // In this case just use the first section (which is usually
635 // the .odp) since the code won't reference the .toc base
637 it = Sections.begin();
640 // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000
641 // thus permitting a full 64 Kbytes segment.
642 return it->LoadAddress + 0x8000;
645 // Returns the sections and offset associated with the ODP entry referenced
647 void RuntimeDyldELF::findOPDEntrySection(ObjectImage &Obj,
648 ObjSectionToIDMap &LocalSections,
649 RelocationValueRef &Rel) {
650 // Get the ELF symbol value (st_value) to compare with Relocation offset in
652 for (section_iterator si = Obj.begin_sections(), se = Obj.end_sections();
654 section_iterator RelSecI = si->getRelocatedSection();
655 if (RelSecI == Obj.end_sections())
658 StringRef RelSectionName;
659 check(RelSecI->getName(RelSectionName));
660 if (RelSectionName != ".opd")
663 for (relocation_iterator i = si->relocation_begin(),
664 e = si->relocation_end();
666 // The R_PPC64_ADDR64 relocation indicates the first field
669 check(i->getType(TypeFunc));
670 if (TypeFunc != ELF::R_PPC64_ADDR64) {
675 uint64_t TargetSymbolOffset;
676 symbol_iterator TargetSymbol = i->getSymbol();
677 check(i->getOffset(TargetSymbolOffset));
679 check(getELFRelocationAddend(*i, Addend));
685 // Just check if following relocation is a R_PPC64_TOC
687 check(i->getType(TypeTOC));
688 if (TypeTOC != ELF::R_PPC64_TOC)
691 // Finally compares the Symbol value and the target symbol offset
692 // to check if this .opd entry refers to the symbol the relocation
694 if (Rel.Addend != (int64_t)TargetSymbolOffset)
697 section_iterator tsi(Obj.end_sections());
698 check(TargetSymbol->getSection(tsi));
701 Rel.SectionID = findOrEmitSection(Obj, (*tsi), IsCode, LocalSections);
702 Rel.Addend = (intptr_t)Addend;
706 llvm_unreachable("Attempting to get address of ODP entry!");
709 // Relocation masks following the #lo(value), #hi(value), #ha(value),
710 // #higher(value), #highera(value), #highest(value), and #highesta(value)
711 // macros defined in section 4.5.1. Relocation Types of the PPC-elf64abi
714 static inline uint16_t applyPPClo(uint64_t value) { return value & 0xffff; }
716 static inline uint16_t applyPPChi(uint64_t value) {
717 return (value >> 16) & 0xffff;
720 static inline uint16_t applyPPCha (uint64_t value) {
721 return ((value + 0x8000) >> 16) & 0xffff;
724 static inline uint16_t applyPPChigher(uint64_t value) {
725 return (value >> 32) & 0xffff;
728 static inline uint16_t applyPPChighera (uint64_t value) {
729 return ((value + 0x8000) >> 32) & 0xffff;
732 static inline uint16_t applyPPChighest(uint64_t value) {
733 return (value >> 48) & 0xffff;
736 static inline uint16_t applyPPChighesta (uint64_t value) {
737 return ((value + 0x8000) >> 48) & 0xffff;
740 void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section,
741 uint64_t Offset, uint64_t Value,
742 uint32_t Type, int64_t Addend) {
743 uint8_t *LocalAddress = Section.Address + Offset;
746 llvm_unreachable("Relocation type not implemented yet!");
748 case ELF::R_PPC64_ADDR16:
749 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
751 case ELF::R_PPC64_ADDR16_DS:
752 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
754 case ELF::R_PPC64_ADDR16_LO:
755 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
757 case ELF::R_PPC64_ADDR16_LO_DS:
758 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
760 case ELF::R_PPC64_ADDR16_HI:
761 writeInt16BE(LocalAddress, applyPPChi(Value + Addend));
763 case ELF::R_PPC64_ADDR16_HA:
764 writeInt16BE(LocalAddress, applyPPCha(Value + Addend));
766 case ELF::R_PPC64_ADDR16_HIGHER:
767 writeInt16BE(LocalAddress, applyPPChigher(Value + Addend));
769 case ELF::R_PPC64_ADDR16_HIGHERA:
770 writeInt16BE(LocalAddress, applyPPChighera(Value + Addend));
772 case ELF::R_PPC64_ADDR16_HIGHEST:
773 writeInt16BE(LocalAddress, applyPPChighest(Value + Addend));
775 case ELF::R_PPC64_ADDR16_HIGHESTA:
776 writeInt16BE(LocalAddress, applyPPChighesta(Value + Addend));
778 case ELF::R_PPC64_ADDR14: {
779 assert(((Value + Addend) & 3) == 0);
780 // Preserve the AA/LK bits in the branch instruction
781 uint8_t aalk = *(LocalAddress + 3);
782 writeInt16BE(LocalAddress + 2, (aalk & 3) | ((Value + Addend) & 0xfffc));
784 case ELF::R_PPC64_REL16_LO: {
785 uint64_t FinalAddress = (Section.LoadAddress + Offset);
786 uint64_t Delta = Value - FinalAddress + Addend;
787 writeInt16BE(LocalAddress, applyPPClo(Delta));
789 case ELF::R_PPC64_REL16_HI: {
790 uint64_t FinalAddress = (Section.LoadAddress + Offset);
791 uint64_t Delta = Value - FinalAddress + Addend;
792 writeInt16BE(LocalAddress, applyPPChi(Delta));
794 case ELF::R_PPC64_REL16_HA: {
795 uint64_t FinalAddress = (Section.LoadAddress + Offset);
796 uint64_t Delta = Value - FinalAddress + Addend;
797 writeInt16BE(LocalAddress, applyPPCha(Delta));
799 case ELF::R_PPC64_ADDR32: {
800 int32_t Result = static_cast<int32_t>(Value + Addend);
801 if (SignExtend32<32>(Result) != Result)
802 llvm_unreachable("Relocation R_PPC64_ADDR32 overflow");
803 writeInt32BE(LocalAddress, Result);
805 case ELF::R_PPC64_REL24: {
806 uint64_t FinalAddress = (Section.LoadAddress + Offset);
807 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
808 if (SignExtend32<24>(delta) != delta)
809 llvm_unreachable("Relocation R_PPC64_REL24 overflow");
810 // Generates a 'bl <address>' instruction
811 writeInt32BE(LocalAddress, 0x48000001 | (delta & 0x03FFFFFC));
813 case ELF::R_PPC64_REL32: {
814 uint64_t FinalAddress = (Section.LoadAddress + Offset);
815 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
816 if (SignExtend32<32>(delta) != delta)
817 llvm_unreachable("Relocation R_PPC64_REL32 overflow");
818 writeInt32BE(LocalAddress, delta);
820 case ELF::R_PPC64_REL64: {
821 uint64_t FinalAddress = (Section.LoadAddress + Offset);
822 uint64_t Delta = Value - FinalAddress + Addend;
823 writeInt64BE(LocalAddress, Delta);
825 case ELF::R_PPC64_ADDR64:
826 writeInt64BE(LocalAddress, Value + Addend);
828 case ELF::R_PPC64_TOC:
829 writeInt64BE(LocalAddress, findPPC64TOC());
831 case ELF::R_PPC64_TOC16: {
832 uint64_t TOCStart = findPPC64TOC();
833 Value = applyPPClo((Value + Addend) - TOCStart);
834 writeInt16BE(LocalAddress, applyPPClo(Value));
836 case ELF::R_PPC64_TOC16_DS: {
837 uint64_t TOCStart = findPPC64TOC();
838 Value = ((Value + Addend) - TOCStart);
839 writeInt16BE(LocalAddress, applyPPClo(Value) & ~3);
841 case ELF::R_PPC64_TOC16_LO: {
842 uint64_t TOCStart = findPPC64TOC();
843 Value = ((Value + Addend) - TOCStart);
844 writeInt16BE(LocalAddress, applyPPClo(Value));
846 case ELF::R_PPC64_TOC16_LO_DS: {
847 uint64_t TOCStart = findPPC64TOC();
848 Value = ((Value + Addend) - TOCStart);
849 writeInt16BE(LocalAddress, applyPPClo(Value) & ~3);
851 case ELF::R_PPC64_TOC16_HI: {
852 uint64_t TOCStart = findPPC64TOC();
853 Value = ((Value + Addend) - TOCStart);
854 writeInt16BE(LocalAddress, applyPPChi(Value));
856 case ELF::R_PPC64_TOC16_HA: {
857 uint64_t TOCStart = findPPC64TOC();
858 Value = ((Value + Addend) - TOCStart);
859 writeInt16BE(LocalAddress, applyPPCha(Value));
864 void RuntimeDyldELF::resolveSystemZRelocation(const SectionEntry &Section,
865 uint64_t Offset, uint64_t Value,
866 uint32_t Type, int64_t Addend) {
867 uint8_t *LocalAddress = Section.Address + Offset;
870 llvm_unreachable("Relocation type not implemented yet!");
872 case ELF::R_390_PC16DBL:
873 case ELF::R_390_PLT16DBL: {
874 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
875 assert(int16_t(Delta / 2) * 2 == Delta && "R_390_PC16DBL overflow");
876 writeInt16BE(LocalAddress, Delta / 2);
879 case ELF::R_390_PC32DBL:
880 case ELF::R_390_PLT32DBL: {
881 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
882 assert(int32_t(Delta / 2) * 2 == Delta && "R_390_PC32DBL overflow");
883 writeInt32BE(LocalAddress, Delta / 2);
886 case ELF::R_390_PC32: {
887 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
888 assert(int32_t(Delta) == Delta && "R_390_PC32 overflow");
889 writeInt32BE(LocalAddress, Delta);
893 writeInt64BE(LocalAddress, Value + Addend);
898 // The target location for the relocation is described by RE.SectionID and
899 // RE.Offset. RE.SectionID can be used to find the SectionEntry. Each
900 // SectionEntry has three members describing its location.
901 // SectionEntry::Address is the address at which the section has been loaded
902 // into memory in the current (host) process. SectionEntry::LoadAddress is the
903 // address that the section will have in the target process.
904 // SectionEntry::ObjAddress is the address of the bits for this section in the
905 // original emitted object image (also in the current address space).
907 // Relocations will be applied as if the section were loaded at
908 // SectionEntry::LoadAddress, but they will be applied at an address based
909 // on SectionEntry::Address. SectionEntry::ObjAddress will be used to refer to
910 // Target memory contents if they are required for value calculations.
912 // The Value parameter here is the load address of the symbol for the
913 // relocation to be applied. For relocations which refer to symbols in the
914 // current object Value will be the LoadAddress of the section in which
915 // the symbol resides (RE.Addend provides additional information about the
916 // symbol location). For external symbols, Value will be the address of the
917 // symbol in the target address space.
918 void RuntimeDyldELF::resolveRelocation(const RelocationEntry &RE,
920 const SectionEntry &Section = Sections[RE.SectionID];
921 return resolveRelocation(Section, RE.Offset, Value, RE.RelType, RE.Addend,
925 void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section,
926 uint64_t Offset, uint64_t Value,
927 uint32_t Type, int64_t Addend,
928 uint64_t SymOffset) {
931 resolveX86_64Relocation(Section, Offset, Value, Type, Addend, SymOffset);
934 resolveX86Relocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
935 (uint32_t)(Addend & 0xffffffffL));
937 case Triple::aarch64:
938 case Triple::aarch64_be:
940 case Triple::arm64_be:
941 resolveAArch64Relocation(Section, Offset, Value, Type, Addend);
943 case Triple::arm: // Fall through.
946 case Triple::thumbeb:
947 resolveARMRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
948 (uint32_t)(Addend & 0xffffffffL));
950 case Triple::mips: // Fall through.
952 resolveMIPSRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL),
953 Type, (uint32_t)(Addend & 0xffffffffL));
955 case Triple::ppc64: // Fall through.
956 case Triple::ppc64le:
957 resolvePPC64Relocation(Section, Offset, Value, Type, Addend);
959 case Triple::systemz:
960 resolveSystemZRelocation(Section, Offset, Value, Type, Addend);
963 llvm_unreachable("Unsupported CPU type!");
967 relocation_iterator RuntimeDyldELF::processRelocationRef(
968 unsigned SectionID, relocation_iterator RelI, ObjectImage &Obj,
969 ObjSectionToIDMap &ObjSectionToID, const SymbolTableMap &Symbols,
972 Check(RelI->getType(RelType));
974 Check(getELFRelocationAddend(*RelI, Addend));
975 symbol_iterator Symbol = RelI->getSymbol();
977 // Obtain the symbol name which is referenced in the relocation
978 StringRef TargetName;
979 if (Symbol != Obj.end_symbols())
980 Symbol->getName(TargetName);
981 DEBUG(dbgs() << "\t\tRelType: " << RelType << " Addend: " << Addend
982 << " TargetName: " << TargetName << "\n");
983 RelocationValueRef Value;
984 // First search for the symbol in the local symbol table
985 SymbolTableMap::const_iterator lsi = Symbols.end();
986 SymbolRef::Type SymType = SymbolRef::ST_Unknown;
987 if (Symbol != Obj.end_symbols()) {
988 lsi = Symbols.find(TargetName.data());
989 Symbol->getType(SymType);
991 if (lsi != Symbols.end()) {
992 Value.SectionID = lsi->second.first;
993 Value.Offset = lsi->second.second;
994 Value.Addend = lsi->second.second + Addend;
996 // Search for the symbol in the global symbol table
997 SymbolTableMap::const_iterator gsi = GlobalSymbolTable.end();
998 if (Symbol != Obj.end_symbols())
999 gsi = GlobalSymbolTable.find(TargetName.data());
1000 if (gsi != GlobalSymbolTable.end()) {
1001 Value.SectionID = gsi->second.first;
1002 Value.Offset = gsi->second.second;
1003 Value.Addend = gsi->second.second + Addend;
1006 case SymbolRef::ST_Debug: {
1007 // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously
1008 // and can be changed by another developers. Maybe best way is add
1009 // a new symbol type ST_Section to SymbolRef and use it.
1010 section_iterator si(Obj.end_sections());
1011 Symbol->getSection(si);
1012 if (si == Obj.end_sections())
1013 llvm_unreachable("Symbol section not found, bad object file format!");
1014 DEBUG(dbgs() << "\t\tThis is section symbol\n");
1015 // Default to 'true' in case isText fails (though it never does).
1018 Value.SectionID = findOrEmitSection(Obj, (*si), isCode, ObjSectionToID);
1019 Value.Addend = Addend;
1022 case SymbolRef::ST_Data:
1023 case SymbolRef::ST_Unknown: {
1024 Value.SymbolName = TargetName.data();
1025 Value.Addend = Addend;
1027 // Absolute relocations will have a zero symbol ID (STN_UNDEF), which
1028 // will manifest here as a NULL symbol name.
1029 // We can set this as a valid (but empty) symbol name, and rely
1030 // on addRelocationForSymbol to handle this.
1031 if (!Value.SymbolName)
1032 Value.SymbolName = "";
1036 llvm_unreachable("Unresolved symbol type!");
1042 Check(RelI->getOffset(Offset));
1044 DEBUG(dbgs() << "\t\tSectionID: " << SectionID << " Offset: " << Offset
1046 if ((Arch == Triple::aarch64 || Arch == Triple::aarch64_be ||
1047 Arch == Triple::arm64 || Arch == Triple::arm64_be) &&
1048 (RelType == ELF::R_AARCH64_CALL26 || RelType == ELF::R_AARCH64_JUMP26)) {
1049 // This is an AArch64 branch relocation, need to use a stub function.
1050 DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation.");
1051 SectionEntry &Section = Sections[SectionID];
1053 // Look for an existing stub.
1054 StubMap::const_iterator i = Stubs.find(Value);
1055 if (i != Stubs.end()) {
1056 resolveRelocation(Section, Offset, (uint64_t)Section.Address + i->second,
1058 DEBUG(dbgs() << " Stub function found\n");
1060 // Create a new stub function.
1061 DEBUG(dbgs() << " Create a new stub function\n");
1062 Stubs[Value] = Section.StubOffset;
1063 uint8_t *StubTargetAddr =
1064 createStubFunction(Section.Address + Section.StubOffset);
1066 RelocationEntry REmovz_g3(SectionID, StubTargetAddr - Section.Address,
1067 ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend);
1068 RelocationEntry REmovk_g2(SectionID, StubTargetAddr - Section.Address + 4,
1069 ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend);
1070 RelocationEntry REmovk_g1(SectionID, StubTargetAddr - Section.Address + 8,
1071 ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend);
1072 RelocationEntry REmovk_g0(SectionID,
1073 StubTargetAddr - Section.Address + 12,
1074 ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend);
1076 if (Value.SymbolName) {
1077 addRelocationForSymbol(REmovz_g3, Value.SymbolName);
1078 addRelocationForSymbol(REmovk_g2, Value.SymbolName);
1079 addRelocationForSymbol(REmovk_g1, Value.SymbolName);
1080 addRelocationForSymbol(REmovk_g0, Value.SymbolName);
1082 addRelocationForSection(REmovz_g3, Value.SectionID);
1083 addRelocationForSection(REmovk_g2, Value.SectionID);
1084 addRelocationForSection(REmovk_g1, Value.SectionID);
1085 addRelocationForSection(REmovk_g0, Value.SectionID);
1087 resolveRelocation(Section, Offset,
1088 (uint64_t)Section.Address + Section.StubOffset, RelType,
1090 Section.StubOffset += getMaxStubSize();
1092 } else if (Arch == Triple::arm &&
1093 (RelType == ELF::R_ARM_PC24 || RelType == ELF::R_ARM_CALL ||
1094 RelType == ELF::R_ARM_JUMP24)) {
1095 // This is an ARM branch relocation, need to use a stub function.
1096 DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.");
1097 SectionEntry &Section = Sections[SectionID];
1099 // Look for an existing stub.
1100 StubMap::const_iterator i = Stubs.find(Value);
1101 if (i != Stubs.end()) {
1102 resolveRelocation(Section, Offset, (uint64_t)Section.Address + i->second,
1104 DEBUG(dbgs() << " Stub function found\n");
1106 // Create a new stub function.
1107 DEBUG(dbgs() << " Create a new stub function\n");
1108 Stubs[Value] = Section.StubOffset;
1109 uint8_t *StubTargetAddr =
1110 createStubFunction(Section.Address + Section.StubOffset);
1111 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1112 ELF::R_ARM_PRIVATE_0, Value.Addend);
1113 if (Value.SymbolName)
1114 addRelocationForSymbol(RE, Value.SymbolName);
1116 addRelocationForSection(RE, Value.SectionID);
1118 resolveRelocation(Section, Offset,
1119 (uint64_t)Section.Address + Section.StubOffset, RelType,
1121 Section.StubOffset += getMaxStubSize();
1123 } else if ((Arch == Triple::mipsel || Arch == Triple::mips) &&
1124 RelType == ELF::R_MIPS_26) {
1125 // This is an Mips branch relocation, need to use a stub function.
1126 DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
1127 SectionEntry &Section = Sections[SectionID];
1128 uint8_t *Target = Section.Address + Offset;
1129 uint32_t *TargetAddress = (uint32_t *)Target;
1131 // Extract the addend from the instruction.
1132 uint32_t Addend = ((*TargetAddress) & 0x03ffffff) << 2;
1134 Value.Addend += Addend;
1136 // Look up for existing stub.
1137 StubMap::const_iterator i = Stubs.find(Value);
1138 if (i != Stubs.end()) {
1139 RelocationEntry RE(SectionID, Offset, RelType, i->second);
1140 addRelocationForSection(RE, SectionID);
1141 DEBUG(dbgs() << " Stub function found\n");
1143 // Create a new stub function.
1144 DEBUG(dbgs() << " Create a new stub function\n");
1145 Stubs[Value] = Section.StubOffset;
1146 uint8_t *StubTargetAddr =
1147 createStubFunction(Section.Address + Section.StubOffset);
1149 // Creating Hi and Lo relocations for the filled stub instructions.
1150 RelocationEntry REHi(SectionID, StubTargetAddr - Section.Address,
1151 ELF::R_MIPS_UNUSED1, Value.Addend);
1152 RelocationEntry RELo(SectionID, StubTargetAddr - Section.Address + 4,
1153 ELF::R_MIPS_UNUSED2, Value.Addend);
1155 if (Value.SymbolName) {
1156 addRelocationForSymbol(REHi, Value.SymbolName);
1157 addRelocationForSymbol(RELo, Value.SymbolName);
1159 addRelocationForSection(REHi, Value.SectionID);
1160 addRelocationForSection(RELo, Value.SectionID);
1163 RelocationEntry RE(SectionID, Offset, RelType, Section.StubOffset);
1164 addRelocationForSection(RE, SectionID);
1165 Section.StubOffset += getMaxStubSize();
1167 } else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) {
1168 if (RelType == ELF::R_PPC64_REL24) {
1169 // A PPC branch relocation will need a stub function if the target is
1170 // an external symbol (Symbol::ST_Unknown) or if the target address
1171 // is not within the signed 24-bits branch address.
1172 SectionEntry &Section = Sections[SectionID];
1173 uint8_t *Target = Section.Address + Offset;
1174 bool RangeOverflow = false;
1175 if (SymType != SymbolRef::ST_Unknown) {
1176 // A function call may points to the .opd entry, so the final symbol
1178 // in calculated based in the relocation values in .opd section.
1179 findOPDEntrySection(Obj, ObjSectionToID, Value);
1180 uint8_t *RelocTarget = Sections[Value.SectionID].Address + Value.Addend;
1181 int32_t delta = static_cast<int32_t>(Target - RelocTarget);
1182 // If it is within 24-bits branch range, just set the branch target
1183 if (SignExtend32<24>(delta) == delta) {
1184 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1185 if (Value.SymbolName)
1186 addRelocationForSymbol(RE, Value.SymbolName);
1188 addRelocationForSection(RE, Value.SectionID);
1190 RangeOverflow = true;
1193 if (SymType == SymbolRef::ST_Unknown || RangeOverflow == true) {
1194 // It is an external symbol (SymbolRef::ST_Unknown) or within a range
1195 // larger than 24-bits.
1196 StubMap::const_iterator i = Stubs.find(Value);
1197 if (i != Stubs.end()) {
1198 // Symbol function stub already created, just relocate to it
1199 resolveRelocation(Section, Offset,
1200 (uint64_t)Section.Address + i->second, RelType, 0);
1201 DEBUG(dbgs() << " Stub function found\n");
1203 // Create a new stub function.
1204 DEBUG(dbgs() << " Create a new stub function\n");
1205 Stubs[Value] = Section.StubOffset;
1206 uint8_t *StubTargetAddr =
1207 createStubFunction(Section.Address + Section.StubOffset);
1208 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1209 ELF::R_PPC64_ADDR64, Value.Addend);
1211 // Generates the 64-bits address loads as exemplified in section
1212 // 4.5.1 in PPC64 ELF ABI. Note that the relocations need to
1213 // apply to the low part of the instructions, so we have to update
1214 // the offset according to the target endianness.
1215 uint64_t StubRelocOffset = StubTargetAddr - Section.Address;
1216 if (!IsTargetLittleEndian)
1217 StubRelocOffset += 2;
1219 RelocationEntry REhst(SectionID, StubRelocOffset + 0,
1220 ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend);
1221 RelocationEntry REhr(SectionID, StubRelocOffset + 4,
1222 ELF::R_PPC64_ADDR16_HIGHER, Value.Addend);
1223 RelocationEntry REh(SectionID, StubRelocOffset + 12,
1224 ELF::R_PPC64_ADDR16_HI, Value.Addend);
1225 RelocationEntry REl(SectionID, StubRelocOffset + 16,
1226 ELF::R_PPC64_ADDR16_LO, Value.Addend);
1228 if (Value.SymbolName) {
1229 addRelocationForSymbol(REhst, Value.SymbolName);
1230 addRelocationForSymbol(REhr, Value.SymbolName);
1231 addRelocationForSymbol(REh, Value.SymbolName);
1232 addRelocationForSymbol(REl, Value.SymbolName);
1234 addRelocationForSection(REhst, Value.SectionID);
1235 addRelocationForSection(REhr, Value.SectionID);
1236 addRelocationForSection(REh, Value.SectionID);
1237 addRelocationForSection(REl, Value.SectionID);
1240 resolveRelocation(Section, Offset,
1241 (uint64_t)Section.Address + Section.StubOffset,
1243 Section.StubOffset += getMaxStubSize();
1245 if (SymType == SymbolRef::ST_Unknown)
1246 // Restore the TOC for external calls
1247 writeInt32BE(Target + 4, 0xE8410028); // ld r2,40(r1)
1250 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1251 // Extra check to avoid relocation againt empty symbols (usually
1252 // the R_PPC64_TOC).
1253 if (SymType != SymbolRef::ST_Unknown && TargetName.empty())
1254 Value.SymbolName = nullptr;
1256 if (Value.SymbolName)
1257 addRelocationForSymbol(RE, Value.SymbolName);
1259 addRelocationForSection(RE, Value.SectionID);
1261 } else if (Arch == Triple::systemz &&
1262 (RelType == ELF::R_390_PLT32DBL || RelType == ELF::R_390_GOTENT)) {
1263 // Create function stubs for both PLT and GOT references, regardless of
1264 // whether the GOT reference is to data or code. The stub contains the
1265 // full address of the symbol, as needed by GOT references, and the
1266 // executable part only adds an overhead of 8 bytes.
1268 // We could try to conserve space by allocating the code and data
1269 // parts of the stub separately. However, as things stand, we allocate
1270 // a stub for every relocation, so using a GOT in JIT code should be
1271 // no less space efficient than using an explicit constant pool.
1272 DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation.");
1273 SectionEntry &Section = Sections[SectionID];
1275 // Look for an existing stub.
1276 StubMap::const_iterator i = Stubs.find(Value);
1277 uintptr_t StubAddress;
1278 if (i != Stubs.end()) {
1279 StubAddress = uintptr_t(Section.Address) + i->second;
1280 DEBUG(dbgs() << " Stub function found\n");
1282 // Create a new stub function.
1283 DEBUG(dbgs() << " Create a new stub function\n");
1285 uintptr_t BaseAddress = uintptr_t(Section.Address);
1286 uintptr_t StubAlignment = getStubAlignment();
1287 StubAddress = (BaseAddress + Section.StubOffset + StubAlignment - 1) &
1289 unsigned StubOffset = StubAddress - BaseAddress;
1291 Stubs[Value] = StubOffset;
1292 createStubFunction((uint8_t *)StubAddress);
1293 RelocationEntry RE(SectionID, StubOffset + 8, ELF::R_390_64,
1294 Value.Addend - Addend);
1295 if (Value.SymbolName)
1296 addRelocationForSymbol(RE, Value.SymbolName);
1298 addRelocationForSection(RE, Value.SectionID);
1299 Section.StubOffset = StubOffset + getMaxStubSize();
1302 if (RelType == ELF::R_390_GOTENT)
1303 resolveRelocation(Section, Offset, StubAddress + 8, ELF::R_390_PC32DBL,
1306 resolveRelocation(Section, Offset, StubAddress, RelType, Addend);
1307 } else if (Arch == Triple::x86_64 && RelType == ELF::R_X86_64_PLT32) {
1308 // The way the PLT relocations normally work is that the linker allocates
1310 // PLT and this relocation makes a PC-relative call into the PLT. The PLT
1311 // entry will then jump to an address provided by the GOT. On first call,
1313 // GOT address will point back into PLT code that resolves the symbol. After
1314 // the first call, the GOT entry points to the actual function.
1316 // For local functions we're ignoring all of that here and just replacing
1317 // the PLT32 relocation type with PC32, which will translate the relocation
1318 // into a PC-relative call directly to the function. For external symbols we
1319 // can't be sure the function will be within 2^32 bytes of the call site, so
1320 // we need to create a stub, which calls into the GOT. This case is
1321 // equivalent to the usual PLT implementation except that we use the stub
1322 // mechanism in RuntimeDyld (which puts stubs at the end of the section)
1323 // rather than allocating a PLT section.
1324 if (Value.SymbolName) {
1325 // This is a call to an external function.
1326 // Look for an existing stub.
1327 SectionEntry &Section = Sections[SectionID];
1328 StubMap::const_iterator i = Stubs.find(Value);
1329 uintptr_t StubAddress;
1330 if (i != Stubs.end()) {
1331 StubAddress = uintptr_t(Section.Address) + i->second;
1332 DEBUG(dbgs() << " Stub function found\n");
1334 // Create a new stub function (equivalent to a PLT entry).
1335 DEBUG(dbgs() << " Create a new stub function\n");
1337 uintptr_t BaseAddress = uintptr_t(Section.Address);
1338 uintptr_t StubAlignment = getStubAlignment();
1339 StubAddress = (BaseAddress + Section.StubOffset + StubAlignment - 1) &
1341 unsigned StubOffset = StubAddress - BaseAddress;
1342 Stubs[Value] = StubOffset;
1343 createStubFunction((uint8_t *)StubAddress);
1345 // Create a GOT entry for the external function.
1346 GOTEntries.push_back(Value);
1348 // Make our stub function a relative call to the GOT entry.
1349 RelocationEntry RE(SectionID, StubOffset + 2, ELF::R_X86_64_GOTPCREL,
1351 addRelocationForSymbol(RE, Value.SymbolName);
1353 // Bump our stub offset counter
1354 Section.StubOffset = StubOffset + getMaxStubSize();
1357 // Make the target call a call into the stub table.
1358 resolveRelocation(Section, Offset, StubAddress, ELF::R_X86_64_PC32,
1361 RelocationEntry RE(SectionID, Offset, ELF::R_X86_64_PC32, Value.Addend,
1363 addRelocationForSection(RE, Value.SectionID);
1366 if (Arch == Triple::x86_64 && RelType == ELF::R_X86_64_GOTPCREL) {
1367 GOTEntries.push_back(Value);
1369 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend, Value.Offset);
1370 if (Value.SymbolName)
1371 addRelocationForSymbol(RE, Value.SymbolName);
1373 addRelocationForSection(RE, Value.SectionID);
1378 void RuntimeDyldELF::updateGOTEntries(StringRef Name, uint64_t Addr) {
1380 SmallVectorImpl<std::pair<SID, GOTRelocations>>::iterator it;
1381 SmallVectorImpl<std::pair<SID, GOTRelocations>>::iterator end = GOTs.end();
1383 for (it = GOTs.begin(); it != end; ++it) {
1384 GOTRelocations &GOTEntries = it->second;
1385 for (int i = 0, e = GOTEntries.size(); i != e; ++i) {
1386 if (GOTEntries[i].SymbolName != nullptr &&
1387 GOTEntries[i].SymbolName == Name) {
1388 GOTEntries[i].Offset = Addr;
1394 size_t RuntimeDyldELF::getGOTEntrySize() {
1395 // We don't use the GOT in all of these cases, but it's essentially free
1396 // to put them all here.
1399 case Triple::x86_64:
1400 case Triple::aarch64:
1401 case Triple::aarch64_be:
1403 case Triple::arm64_be:
1405 case Triple::ppc64le:
1406 case Triple::systemz:
1407 Result = sizeof(uint64_t);
1413 case Triple::mipsel:
1414 Result = sizeof(uint32_t);
1417 llvm_unreachable("Unsupported CPU type!");
1422 uint64_t RuntimeDyldELF::findGOTEntry(uint64_t LoadAddress, uint64_t Offset) {
1424 const size_t GOTEntrySize = getGOTEntrySize();
1426 SmallVectorImpl<std::pair<SID, GOTRelocations>>::const_iterator it;
1427 SmallVectorImpl<std::pair<SID, GOTRelocations>>::const_iterator end =
1431 for (it = GOTs.begin(); it != end; ++it) {
1432 SID GOTSectionID = it->first;
1433 const GOTRelocations &GOTEntries = it->second;
1435 // Find the matching entry in our vector.
1436 uint64_t SymbolOffset = 0;
1437 for (int i = 0, e = GOTEntries.size(); i != e; ++i) {
1438 if (!GOTEntries[i].SymbolName) {
1439 if (getSectionLoadAddress(GOTEntries[i].SectionID) == LoadAddress &&
1440 GOTEntries[i].Offset == Offset) {
1442 SymbolOffset = GOTEntries[i].Offset;
1446 // GOT entries for external symbols use the addend as the address when
1447 // the external symbol has been resolved.
1448 if (GOTEntries[i].Offset == LoadAddress) {
1450 // Don't use the Addend here. The relocation handler will use it.
1456 if (GOTIndex != -1) {
1457 if (GOTEntrySize == sizeof(uint64_t)) {
1458 uint64_t *LocalGOTAddr = (uint64_t *)getSectionAddress(GOTSectionID);
1459 // Fill in this entry with the address of the symbol being referenced.
1460 LocalGOTAddr[GOTIndex] = LoadAddress + SymbolOffset;
1462 uint32_t *LocalGOTAddr = (uint32_t *)getSectionAddress(GOTSectionID);
1463 // Fill in this entry with the address of the symbol being referenced.
1464 LocalGOTAddr[GOTIndex] = (uint32_t)(LoadAddress + SymbolOffset);
1467 // Calculate the load address of this entry
1468 return getSectionLoadAddress(GOTSectionID) + (GOTIndex * GOTEntrySize);
1472 assert(GOTIndex != -1 && "Unable to find requested GOT entry.");
1476 void RuntimeDyldELF::finalizeLoad(ObjectImage &ObjImg,
1477 ObjSectionToIDMap &SectionMap) {
1478 // If necessary, allocate the global offset table
1480 // Allocate the GOT if necessary
1481 size_t numGOTEntries = GOTEntries.size();
1482 if (numGOTEntries != 0) {
1483 // Allocate memory for the section
1484 unsigned SectionID = Sections.size();
1485 size_t TotalSize = numGOTEntries * getGOTEntrySize();
1486 uint8_t *Addr = MemMgr->allocateDataSection(TotalSize, getGOTEntrySize(),
1487 SectionID, ".got", false);
1489 report_fatal_error("Unable to allocate memory for GOT!");
1491 GOTs.push_back(std::make_pair(SectionID, GOTEntries));
1492 Sections.push_back(SectionEntry(".got", Addr, TotalSize, 0));
1493 // For now, initialize all GOT entries to zero. We'll fill them in as
1494 // needed when GOT-based relocations are applied.
1495 memset(Addr, 0, TotalSize);
1498 report_fatal_error("Unable to allocate memory for GOT!");
1501 // Look for and record the EH frame section.
1502 ObjSectionToIDMap::iterator i, e;
1503 for (i = SectionMap.begin(), e = SectionMap.end(); i != e; ++i) {
1504 const SectionRef &Section = i->first;
1506 Section.getName(Name);
1507 if (Name == ".eh_frame") {
1508 UnregisteredEHFrameSections.push_back(i->second);
1514 bool RuntimeDyldELF::isCompatibleFormat(const ObjectBuffer *Buffer) const {
1515 if (Buffer->getBufferSize() < strlen(ELF::ElfMagic))
1517 return (memcmp(Buffer->getBufferStart(), ELF::ElfMagic,
1518 strlen(ELF::ElfMagic))) == 0;
1521 bool RuntimeDyldELF::isCompatibleFile(const object::ObjectFile *Obj) const {
1522 return Obj->isELF();