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 MemoryBufferRef Wrapper, std::error_code &ec);
60 DyldELFObject(MemoryBufferRef 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(MemoryBufferRef 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 MemoryBufferRef 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 MemoryBufferRef Buffer = ObjFile->getMemoryBufferRef();
188 if (ObjFile->getBytesInAddress() == 4 && ObjFile->isLittleEndian()) {
190 llvm::make_unique<DyldELFObject<ELFType<support::little, 2, false>>>(
191 std::move(ObjFile), Buffer, ec);
192 return new ELFObjectImage<ELFType<support::little, 2, false>>(
193 nullptr, std::move(Obj));
194 } else if (ObjFile->getBytesInAddress() == 4 && !ObjFile->isLittleEndian()) {
196 llvm::make_unique<DyldELFObject<ELFType<support::big, 2, false>>>(
197 std::move(ObjFile), Buffer, ec);
198 return new ELFObjectImage<ELFType<support::big, 2, false>>(nullptr, std::move(Obj));
199 } else if (ObjFile->getBytesInAddress() == 8 && !ObjFile->isLittleEndian()) {
200 auto Obj = llvm::make_unique<DyldELFObject<ELFType<support::big, 2, true>>>(
201 std::move(ObjFile), Buffer, ec);
202 return new ELFObjectImage<ELFType<support::big, 2, true>>(nullptr,
204 } else if (ObjFile->getBytesInAddress() == 8 && ObjFile->isLittleEndian()) {
206 llvm::make_unique<DyldELFObject<ELFType<support::little, 2, true>>>(
207 std::move(ObjFile), Buffer, ec);
208 return new ELFObjectImage<ELFType<support::little, 2, true>>(
209 nullptr, std::move(Obj));
211 llvm_unreachable("Unexpected ELF format");
214 ObjectImage *RuntimeDyldELF::createObjectImage(ObjectBuffer *Buffer) {
215 if (Buffer->getBufferSize() < ELF::EI_NIDENT)
216 llvm_unreachable("Unexpected ELF object size");
217 std::pair<unsigned char, unsigned char> Ident =
218 std::make_pair((uint8_t)Buffer->getBufferStart()[ELF::EI_CLASS],
219 (uint8_t)Buffer->getBufferStart()[ELF::EI_DATA]);
222 MemoryBufferRef Buf = Buffer->getMemBuffer();
224 if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2LSB) {
226 llvm::make_unique<DyldELFObject<ELFType<support::little, 4, false>>>(
228 return new ELFObjectImage<ELFType<support::little, 4, false>>(
229 Buffer, std::move(Obj));
230 } else if (Ident.first == ELF::ELFCLASS32 &&
231 Ident.second == ELF::ELFDATA2MSB) {
233 llvm::make_unique<DyldELFObject<ELFType<support::big, 4, false>>>(Buf,
235 return new ELFObjectImage<ELFType<support::big, 4, false>>(Buffer,
237 } else if (Ident.first == ELF::ELFCLASS64 &&
238 Ident.second == ELF::ELFDATA2MSB) {
239 auto Obj = llvm::make_unique<DyldELFObject<ELFType<support::big, 8, true>>>(
241 return new ELFObjectImage<ELFType<support::big, 8, true>>(Buffer, std::move(Obj));
242 } else if (Ident.first == ELF::ELFCLASS64 &&
243 Ident.second == ELF::ELFDATA2LSB) {
245 llvm::make_unique<DyldELFObject<ELFType<support::little, 8, true>>>(Buf,
247 return new ELFObjectImage<ELFType<support::little, 8, true>>(Buffer, std::move(Obj));
249 llvm_unreachable("Unexpected ELF format");
252 RuntimeDyldELF::~RuntimeDyldELF() {}
254 void RuntimeDyldELF::resolveX86_64Relocation(const SectionEntry &Section,
255 uint64_t Offset, uint64_t Value,
256 uint32_t Type, int64_t Addend,
257 uint64_t SymOffset) {
260 llvm_unreachable("Relocation type not implemented yet!");
262 case ELF::R_X86_64_64: {
263 uint64_t *Target = reinterpret_cast<uint64_t *>(Section.Address + Offset);
264 *Target = Value + Addend;
265 DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend)) << " at "
266 << format("%p\n", Target));
269 case ELF::R_X86_64_32:
270 case ELF::R_X86_64_32S: {
272 assert((Type == ELF::R_X86_64_32 && (Value <= UINT32_MAX)) ||
273 (Type == ELF::R_X86_64_32S &&
274 ((int64_t)Value <= INT32_MAX && (int64_t)Value >= INT32_MIN)));
275 uint32_t TruncatedAddr = (Value & 0xFFFFFFFF);
276 uint32_t *Target = reinterpret_cast<uint32_t *>(Section.Address + Offset);
277 *Target = TruncatedAddr;
278 DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr) << " at "
279 << format("%p\n", Target));
282 case ELF::R_X86_64_GOTPCREL: {
283 // findGOTEntry returns the 'G + GOT' part of the relocation calculation
284 // based on the load/target address of the GOT (not the current/local addr).
285 uint64_t GOTAddr = findGOTEntry(Value, SymOffset);
286 uint32_t *Target = reinterpret_cast<uint32_t *>(Section.Address + Offset);
287 uint64_t FinalAddress = Section.LoadAddress + Offset;
288 // The processRelocationRef method combines the symbol offset and the addend
289 // and in most cases that's what we want. For this relocation type, we need
290 // the raw addend, so we subtract the symbol offset to get it.
291 int64_t RealOffset = GOTAddr + Addend - SymOffset - FinalAddress;
292 assert(RealOffset <= INT32_MAX && RealOffset >= INT32_MIN);
293 int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
294 *Target = TruncOffset;
297 case ELF::R_X86_64_PC32: {
298 // Get the placeholder value from the generated object since
299 // a previous relocation attempt may have overwritten the loaded version
300 uint32_t *Placeholder =
301 reinterpret_cast<uint32_t *>(Section.ObjAddress + Offset);
302 uint32_t *Target = reinterpret_cast<uint32_t *>(Section.Address + Offset);
303 uint64_t FinalAddress = Section.LoadAddress + Offset;
304 int64_t RealOffset = *Placeholder + Value + Addend - FinalAddress;
305 assert(RealOffset <= INT32_MAX && RealOffset >= INT32_MIN);
306 int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
307 *Target = TruncOffset;
310 case ELF::R_X86_64_PC64: {
311 // Get the placeholder value from the generated object since
312 // a previous relocation attempt may have overwritten the loaded version
313 uint64_t *Placeholder =
314 reinterpret_cast<uint64_t *>(Section.ObjAddress + Offset);
315 uint64_t *Target = reinterpret_cast<uint64_t *>(Section.Address + Offset);
316 uint64_t FinalAddress = Section.LoadAddress + Offset;
317 *Target = *Placeholder + Value + Addend - FinalAddress;
323 void RuntimeDyldELF::resolveX86Relocation(const SectionEntry &Section,
324 uint64_t Offset, uint32_t Value,
325 uint32_t Type, int32_t Addend) {
327 case ELF::R_386_32: {
328 // Get the placeholder value from the generated object since
329 // a previous relocation attempt may have overwritten the loaded version
330 uint32_t *Placeholder =
331 reinterpret_cast<uint32_t *>(Section.ObjAddress + Offset);
332 uint32_t *Target = reinterpret_cast<uint32_t *>(Section.Address + Offset);
333 *Target = *Placeholder + Value + Addend;
336 case ELF::R_386_PC32: {
337 // Get the placeholder value from the generated object since
338 // a previous relocation attempt may have overwritten the loaded version
339 uint32_t *Placeholder =
340 reinterpret_cast<uint32_t *>(Section.ObjAddress + Offset);
341 uint32_t *Target = reinterpret_cast<uint32_t *>(Section.Address + Offset);
342 uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
343 uint32_t RealOffset = *Placeholder + Value + Addend - FinalAddress;
344 *Target = RealOffset;
348 // There are other relocation types, but it appears these are the
349 // only ones currently used by the LLVM ELF object writer
350 llvm_unreachable("Relocation type not implemented yet!");
355 void RuntimeDyldELF::resolveAArch64Relocation(const SectionEntry &Section,
356 uint64_t Offset, uint64_t Value,
357 uint32_t Type, int64_t Addend) {
358 uint32_t *TargetPtr = reinterpret_cast<uint32_t *>(Section.Address + Offset);
359 uint64_t FinalAddress = Section.LoadAddress + Offset;
361 DEBUG(dbgs() << "resolveAArch64Relocation, LocalAddress: 0x"
362 << format("%llx", Section.Address + Offset)
363 << " FinalAddress: 0x" << format("%llx", FinalAddress)
364 << " Value: 0x" << format("%llx", Value) << " Type: 0x"
365 << format("%x", Type) << " Addend: 0x" << format("%llx", Addend)
370 llvm_unreachable("Relocation type not implemented yet!");
372 case ELF::R_AARCH64_ABS64: {
373 uint64_t *TargetPtr =
374 reinterpret_cast<uint64_t *>(Section.Address + Offset);
375 *TargetPtr = Value + Addend;
378 case ELF::R_AARCH64_PREL32: {
379 uint64_t Result = Value + Addend - FinalAddress;
380 assert(static_cast<int64_t>(Result) >= INT32_MIN &&
381 static_cast<int64_t>(Result) <= UINT32_MAX);
382 *TargetPtr = static_cast<uint32_t>(Result & 0xffffffffU);
385 case ELF::R_AARCH64_CALL26: // fallthrough
386 case ELF::R_AARCH64_JUMP26: {
387 // Operation: S+A-P. Set Call or B immediate value to bits fff_fffc of the
389 uint64_t BranchImm = Value + Addend - FinalAddress;
391 // "Check that -2^27 <= result < 2^27".
392 assert(-(1LL << 27) <= static_cast<int64_t>(BranchImm) &&
393 static_cast<int64_t>(BranchImm) < (1LL << 27));
395 // AArch64 code is emitted with .rela relocations. The data already in any
396 // bits affected by the relocation on entry is garbage.
397 *TargetPtr &= 0xfc000000U;
398 // Immediate goes in bits 25:0 of B and BL.
399 *TargetPtr |= static_cast<uint32_t>(BranchImm & 0xffffffcU) >> 2;
402 case ELF::R_AARCH64_MOVW_UABS_G3: {
403 uint64_t Result = Value + Addend;
405 // AArch64 code is emitted with .rela relocations. The data already in any
406 // bits affected by the relocation on entry is garbage.
407 *TargetPtr &= 0xffe0001fU;
408 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
409 *TargetPtr |= Result >> (48 - 5);
410 // Shift must be "lsl #48", in bits 22:21
411 assert((*TargetPtr >> 21 & 0x3) == 3 && "invalid shift for relocation");
414 case ELF::R_AARCH64_MOVW_UABS_G2_NC: {
415 uint64_t Result = Value + Addend;
417 // AArch64 code is emitted with .rela relocations. The data already in any
418 // bits affected by the relocation on entry is garbage.
419 *TargetPtr &= 0xffe0001fU;
420 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
421 *TargetPtr |= ((Result & 0xffff00000000ULL) >> (32 - 5));
422 // Shift must be "lsl #32", in bits 22:21
423 assert((*TargetPtr >> 21 & 0x3) == 2 && "invalid shift for relocation");
426 case ELF::R_AARCH64_MOVW_UABS_G1_NC: {
427 uint64_t Result = Value + Addend;
429 // AArch64 code is emitted with .rela relocations. The data already in any
430 // bits affected by the relocation on entry is garbage.
431 *TargetPtr &= 0xffe0001fU;
432 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
433 *TargetPtr |= ((Result & 0xffff0000U) >> (16 - 5));
434 // Shift must be "lsl #16", in bits 22:2
435 assert((*TargetPtr >> 21 & 0x3) == 1 && "invalid shift for relocation");
438 case ELF::R_AARCH64_MOVW_UABS_G0_NC: {
439 uint64_t Result = Value + Addend;
441 // AArch64 code is emitted with .rela relocations. The data already in any
442 // bits affected by the relocation on entry is garbage.
443 *TargetPtr &= 0xffe0001fU;
444 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
445 *TargetPtr |= ((Result & 0xffffU) << 5);
446 // Shift must be "lsl #0", in bits 22:21.
447 assert((*TargetPtr >> 21 & 0x3) == 0 && "invalid shift for relocation");
450 case ELF::R_AARCH64_ADR_PREL_PG_HI21: {
451 // Operation: Page(S+A) - Page(P)
453 ((Value + Addend) & ~0xfffULL) - (FinalAddress & ~0xfffULL);
455 // Check that -2^32 <= X < 2^32
456 assert(static_cast<int64_t>(Result) >= (-1LL << 32) &&
457 static_cast<int64_t>(Result) < (1LL << 32) &&
458 "overflow check failed for relocation");
460 // AArch64 code is emitted with .rela relocations. The data already in any
461 // bits affected by the relocation on entry is garbage.
462 *TargetPtr &= 0x9f00001fU;
463 // Immediate goes in bits 30:29 + 5:23 of ADRP instruction, taken
464 // from bits 32:12 of X.
465 *TargetPtr |= ((Result & 0x3000U) << (29 - 12));
466 *TargetPtr |= ((Result & 0x1ffffc000ULL) >> (14 - 5));
469 case ELF::R_AARCH64_LDST32_ABS_LO12_NC: {
471 uint64_t Result = Value + Addend;
473 // AArch64 code is emitted with .rela relocations. The data already in any
474 // bits affected by the relocation on entry is garbage.
475 *TargetPtr &= 0xffc003ffU;
476 // Immediate goes in bits 21:10 of LD/ST instruction, taken
477 // from bits 11:2 of X
478 *TargetPtr |= ((Result & 0xffc) << (10 - 2));
481 case ELF::R_AARCH64_LDST64_ABS_LO12_NC: {
483 uint64_t Result = Value + Addend;
485 // AArch64 code is emitted with .rela relocations. The data already in any
486 // bits affected by the relocation on entry is garbage.
487 *TargetPtr &= 0xffc003ffU;
488 // Immediate goes in bits 21:10 of LD/ST instruction, taken
489 // from bits 11:3 of X
490 *TargetPtr |= ((Result & 0xff8) << (10 - 3));
496 void RuntimeDyldELF::resolveARMRelocation(const SectionEntry &Section,
497 uint64_t Offset, uint32_t Value,
498 uint32_t Type, int32_t Addend) {
499 // TODO: Add Thumb relocations.
500 uint32_t *Placeholder =
501 reinterpret_cast<uint32_t *>(Section.ObjAddress + Offset);
502 uint32_t *TargetPtr = (uint32_t *)(Section.Address + Offset);
503 uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
506 DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: "
507 << Section.Address + Offset
508 << " FinalAddress: " << format("%p", FinalAddress) << " Value: "
509 << format("%x", Value) << " Type: " << format("%x", Type)
510 << " Addend: " << format("%x", Addend) << "\n");
514 llvm_unreachable("Not implemented relocation type!");
516 case ELF::R_ARM_NONE:
518 // Write a 32bit value to relocation address, taking into account the
519 // implicit addend encoded in the target.
520 case ELF::R_ARM_PREL31:
521 case ELF::R_ARM_TARGET1:
522 case ELF::R_ARM_ABS32:
523 *TargetPtr = *Placeholder + Value;
525 // Write first 16 bit of 32 bit value to the mov instruction.
526 // Last 4 bit should be shifted.
527 case ELF::R_ARM_MOVW_ABS_NC:
528 // We are not expecting any other addend in the relocation address.
529 // Using 0x000F0FFF because MOVW has its 16 bit immediate split into 2
530 // non-contiguous fields.
531 assert((*Placeholder & 0x000F0FFF) == 0);
532 Value = Value & 0xFFFF;
533 *TargetPtr = *Placeholder | (Value & 0xFFF);
534 *TargetPtr |= ((Value >> 12) & 0xF) << 16;
536 // Write last 16 bit of 32 bit value to the mov instruction.
537 // Last 4 bit should be shifted.
538 case ELF::R_ARM_MOVT_ABS:
539 // We are not expecting any other addend in the relocation address.
540 // Use 0x000F0FFF for the same reason as R_ARM_MOVW_ABS_NC.
541 assert((*Placeholder & 0x000F0FFF) == 0);
543 Value = (Value >> 16) & 0xFFFF;
544 *TargetPtr = *Placeholder | (Value & 0xFFF);
545 *TargetPtr |= ((Value >> 12) & 0xF) << 16;
547 // Write 24 bit relative value to the branch instruction.
548 case ELF::R_ARM_PC24: // Fall through.
549 case ELF::R_ARM_CALL: // Fall through.
550 case ELF::R_ARM_JUMP24: {
551 int32_t RelValue = static_cast<int32_t>(Value - FinalAddress - 8);
552 RelValue = (RelValue & 0x03FFFFFC) >> 2;
553 assert((*TargetPtr & 0xFFFFFF) == 0xFFFFFE);
554 *TargetPtr &= 0xFF000000;
555 *TargetPtr |= RelValue;
558 case ELF::R_ARM_PRIVATE_0:
559 // This relocation is reserved by the ARM ELF ABI for internal use. We
560 // appropriate it here to act as an R_ARM_ABS32 without any addend for use
561 // in the stubs created during JIT (which can't put an addend into the
562 // original object file).
568 void RuntimeDyldELF::resolveMIPSRelocation(const SectionEntry &Section,
569 uint64_t Offset, uint32_t Value,
570 uint32_t Type, int32_t Addend) {
571 uint32_t *Placeholder =
572 reinterpret_cast<uint32_t *>(Section.ObjAddress + Offset);
573 uint32_t *TargetPtr = (uint32_t *)(Section.Address + Offset);
576 DEBUG(dbgs() << "resolveMipselocation, LocalAddress: "
577 << Section.Address + Offset << " FinalAddress: "
578 << format("%p", Section.LoadAddress + Offset) << " Value: "
579 << format("%x", Value) << " Type: " << format("%x", Type)
580 << " Addend: " << format("%x", Addend) << "\n");
584 llvm_unreachable("Not implemented relocation type!");
587 *TargetPtr = Value + (*Placeholder);
590 *TargetPtr = ((*Placeholder) & 0xfc000000) | ((Value & 0x0fffffff) >> 2);
592 case ELF::R_MIPS_HI16:
593 // Get the higher 16-bits. Also add 1 if bit 15 is 1.
594 Value += ((*Placeholder) & 0x0000ffff) << 16;
596 ((*Placeholder) & 0xffff0000) | (((Value + 0x8000) >> 16) & 0xffff);
598 case ELF::R_MIPS_LO16:
599 Value += ((*Placeholder) & 0x0000ffff);
600 *TargetPtr = ((*Placeholder) & 0xffff0000) | (Value & 0xffff);
602 case ELF::R_MIPS_UNUSED1:
603 // Similar to ELF::R_ARM_PRIVATE_0, R_MIPS_UNUSED1 and R_MIPS_UNUSED2
604 // are used for internal JIT purpose. These relocations are similar to
605 // R_MIPS_HI16 and R_MIPS_LO16, but they do not take any addend into
608 ((*TargetPtr) & 0xffff0000) | (((Value + 0x8000) >> 16) & 0xffff);
610 case ELF::R_MIPS_UNUSED2:
611 *TargetPtr = ((*TargetPtr) & 0xffff0000) | (Value & 0xffff);
616 // Return the .TOC. section and offset.
617 void RuntimeDyldELF::findPPC64TOCSection(ObjectImage &Obj,
618 ObjSectionToIDMap &LocalSections,
619 RelocationValueRef &Rel) {
620 // Set a default SectionID in case we do not find a TOC section below.
621 // This may happen for references to TOC base base (sym@toc, .odp
622 // relocation) without a .toc directive. In this case just use the
623 // first section (which is usually the .odp) since the code won't
624 // reference the .toc base directly.
625 Rel.SymbolName = NULL;
628 // The TOC consists of sections .got, .toc, .tocbss, .plt in that
629 // order. The TOC starts where the first of these sections starts.
630 for (section_iterator si = Obj.begin_sections(), se = Obj.end_sections();
633 StringRef SectionName;
634 check(si->getName(SectionName));
636 if (SectionName == ".got"
637 || SectionName == ".toc"
638 || SectionName == ".tocbss"
639 || SectionName == ".plt") {
640 Rel.SectionID = findOrEmitSection(Obj, *si, false, LocalSections);
645 // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000
646 // thus permitting a full 64 Kbytes segment.
650 // Returns the sections and offset associated with the ODP entry referenced
652 void RuntimeDyldELF::findOPDEntrySection(ObjectImage &Obj,
653 ObjSectionToIDMap &LocalSections,
654 RelocationValueRef &Rel) {
655 // Get the ELF symbol value (st_value) to compare with Relocation offset in
657 for (section_iterator si = Obj.begin_sections(), se = Obj.end_sections();
659 section_iterator RelSecI = si->getRelocatedSection();
660 if (RelSecI == Obj.end_sections())
663 StringRef RelSectionName;
664 check(RelSecI->getName(RelSectionName));
665 if (RelSectionName != ".opd")
668 for (relocation_iterator i = si->relocation_begin(),
669 e = si->relocation_end();
671 // The R_PPC64_ADDR64 relocation indicates the first field
674 check(i->getType(TypeFunc));
675 if (TypeFunc != ELF::R_PPC64_ADDR64) {
680 uint64_t TargetSymbolOffset;
681 symbol_iterator TargetSymbol = i->getSymbol();
682 check(i->getOffset(TargetSymbolOffset));
684 check(getELFRelocationAddend(*i, Addend));
690 // Just check if following relocation is a R_PPC64_TOC
692 check(i->getType(TypeTOC));
693 if (TypeTOC != ELF::R_PPC64_TOC)
696 // Finally compares the Symbol value and the target symbol offset
697 // to check if this .opd entry refers to the symbol the relocation
699 if (Rel.Addend != (int64_t)TargetSymbolOffset)
702 section_iterator tsi(Obj.end_sections());
703 check(TargetSymbol->getSection(tsi));
706 Rel.SectionID = findOrEmitSection(Obj, (*tsi), IsCode, LocalSections);
707 Rel.Addend = (intptr_t)Addend;
711 llvm_unreachable("Attempting to get address of ODP entry!");
714 // Relocation masks following the #lo(value), #hi(value), #ha(value),
715 // #higher(value), #highera(value), #highest(value), and #highesta(value)
716 // macros defined in section 4.5.1. Relocation Types of the PPC-elf64abi
719 static inline uint16_t applyPPClo(uint64_t value) { return value & 0xffff; }
721 static inline uint16_t applyPPChi(uint64_t value) {
722 return (value >> 16) & 0xffff;
725 static inline uint16_t applyPPCha (uint64_t value) {
726 return ((value + 0x8000) >> 16) & 0xffff;
729 static inline uint16_t applyPPChigher(uint64_t value) {
730 return (value >> 32) & 0xffff;
733 static inline uint16_t applyPPChighera (uint64_t value) {
734 return ((value + 0x8000) >> 32) & 0xffff;
737 static inline uint16_t applyPPChighest(uint64_t value) {
738 return (value >> 48) & 0xffff;
741 static inline uint16_t applyPPChighesta (uint64_t value) {
742 return ((value + 0x8000) >> 48) & 0xffff;
745 void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section,
746 uint64_t Offset, uint64_t Value,
747 uint32_t Type, int64_t Addend) {
748 uint8_t *LocalAddress = Section.Address + Offset;
751 llvm_unreachable("Relocation type not implemented yet!");
753 case ELF::R_PPC64_ADDR16:
754 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
756 case ELF::R_PPC64_ADDR16_DS:
757 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
759 case ELF::R_PPC64_ADDR16_LO:
760 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
762 case ELF::R_PPC64_ADDR16_LO_DS:
763 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
765 case ELF::R_PPC64_ADDR16_HI:
766 writeInt16BE(LocalAddress, applyPPChi(Value + Addend));
768 case ELF::R_PPC64_ADDR16_HA:
769 writeInt16BE(LocalAddress, applyPPCha(Value + Addend));
771 case ELF::R_PPC64_ADDR16_HIGHER:
772 writeInt16BE(LocalAddress, applyPPChigher(Value + Addend));
774 case ELF::R_PPC64_ADDR16_HIGHERA:
775 writeInt16BE(LocalAddress, applyPPChighera(Value + Addend));
777 case ELF::R_PPC64_ADDR16_HIGHEST:
778 writeInt16BE(LocalAddress, applyPPChighest(Value + Addend));
780 case ELF::R_PPC64_ADDR16_HIGHESTA:
781 writeInt16BE(LocalAddress, applyPPChighesta(Value + Addend));
783 case ELF::R_PPC64_ADDR14: {
784 assert(((Value + Addend) & 3) == 0);
785 // Preserve the AA/LK bits in the branch instruction
786 uint8_t aalk = *(LocalAddress + 3);
787 writeInt16BE(LocalAddress + 2, (aalk & 3) | ((Value + Addend) & 0xfffc));
789 case ELF::R_PPC64_REL16_LO: {
790 uint64_t FinalAddress = (Section.LoadAddress + Offset);
791 uint64_t Delta = Value - FinalAddress + Addend;
792 writeInt16BE(LocalAddress, applyPPClo(Delta));
794 case ELF::R_PPC64_REL16_HI: {
795 uint64_t FinalAddress = (Section.LoadAddress + Offset);
796 uint64_t Delta = Value - FinalAddress + Addend;
797 writeInt16BE(LocalAddress, applyPPChi(Delta));
799 case ELF::R_PPC64_REL16_HA: {
800 uint64_t FinalAddress = (Section.LoadAddress + Offset);
801 uint64_t Delta = Value - FinalAddress + Addend;
802 writeInt16BE(LocalAddress, applyPPCha(Delta));
804 case ELF::R_PPC64_ADDR32: {
805 int32_t Result = static_cast<int32_t>(Value + Addend);
806 if (SignExtend32<32>(Result) != Result)
807 llvm_unreachable("Relocation R_PPC64_ADDR32 overflow");
808 writeInt32BE(LocalAddress, Result);
810 case ELF::R_PPC64_REL24: {
811 uint64_t FinalAddress = (Section.LoadAddress + Offset);
812 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
813 if (SignExtend32<24>(delta) != delta)
814 llvm_unreachable("Relocation R_PPC64_REL24 overflow");
815 // Generates a 'bl <address>' instruction
816 writeInt32BE(LocalAddress, 0x48000001 | (delta & 0x03FFFFFC));
818 case ELF::R_PPC64_REL32: {
819 uint64_t FinalAddress = (Section.LoadAddress + Offset);
820 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
821 if (SignExtend32<32>(delta) != delta)
822 llvm_unreachable("Relocation R_PPC64_REL32 overflow");
823 writeInt32BE(LocalAddress, delta);
825 case ELF::R_PPC64_REL64: {
826 uint64_t FinalAddress = (Section.LoadAddress + Offset);
827 uint64_t Delta = Value - FinalAddress + Addend;
828 writeInt64BE(LocalAddress, Delta);
830 case ELF::R_PPC64_ADDR64:
831 writeInt64BE(LocalAddress, Value + Addend);
836 void RuntimeDyldELF::resolveSystemZRelocation(const SectionEntry &Section,
837 uint64_t Offset, uint64_t Value,
838 uint32_t Type, int64_t Addend) {
839 uint8_t *LocalAddress = Section.Address + Offset;
842 llvm_unreachable("Relocation type not implemented yet!");
844 case ELF::R_390_PC16DBL:
845 case ELF::R_390_PLT16DBL: {
846 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
847 assert(int16_t(Delta / 2) * 2 == Delta && "R_390_PC16DBL overflow");
848 writeInt16BE(LocalAddress, Delta / 2);
851 case ELF::R_390_PC32DBL:
852 case ELF::R_390_PLT32DBL: {
853 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
854 assert(int32_t(Delta / 2) * 2 == Delta && "R_390_PC32DBL overflow");
855 writeInt32BE(LocalAddress, Delta / 2);
858 case ELF::R_390_PC32: {
859 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
860 assert(int32_t(Delta) == Delta && "R_390_PC32 overflow");
861 writeInt32BE(LocalAddress, Delta);
865 writeInt64BE(LocalAddress, Value + Addend);
870 // The target location for the relocation is described by RE.SectionID and
871 // RE.Offset. RE.SectionID can be used to find the SectionEntry. Each
872 // SectionEntry has three members describing its location.
873 // SectionEntry::Address is the address at which the section has been loaded
874 // into memory in the current (host) process. SectionEntry::LoadAddress is the
875 // address that the section will have in the target process.
876 // SectionEntry::ObjAddress is the address of the bits for this section in the
877 // original emitted object image (also in the current address space).
879 // Relocations will be applied as if the section were loaded at
880 // SectionEntry::LoadAddress, but they will be applied at an address based
881 // on SectionEntry::Address. SectionEntry::ObjAddress will be used to refer to
882 // Target memory contents if they are required for value calculations.
884 // The Value parameter here is the load address of the symbol for the
885 // relocation to be applied. For relocations which refer to symbols in the
886 // current object Value will be the LoadAddress of the section in which
887 // the symbol resides (RE.Addend provides additional information about the
888 // symbol location). For external symbols, Value will be the address of the
889 // symbol in the target address space.
890 void RuntimeDyldELF::resolveRelocation(const RelocationEntry &RE,
892 const SectionEntry &Section = Sections[RE.SectionID];
893 return resolveRelocation(Section, RE.Offset, Value, RE.RelType, RE.Addend,
897 void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section,
898 uint64_t Offset, uint64_t Value,
899 uint32_t Type, int64_t Addend,
900 uint64_t SymOffset) {
903 resolveX86_64Relocation(Section, Offset, Value, Type, Addend, SymOffset);
906 resolveX86Relocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
907 (uint32_t)(Addend & 0xffffffffL));
909 case Triple::aarch64:
910 case Triple::aarch64_be:
911 resolveAArch64Relocation(Section, Offset, Value, Type, Addend);
913 case Triple::arm: // Fall through.
916 case Triple::thumbeb:
917 resolveARMRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
918 (uint32_t)(Addend & 0xffffffffL));
920 case Triple::mips: // Fall through.
922 resolveMIPSRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL),
923 Type, (uint32_t)(Addend & 0xffffffffL));
925 case Triple::ppc64: // Fall through.
926 case Triple::ppc64le:
927 resolvePPC64Relocation(Section, Offset, Value, Type, Addend);
929 case Triple::systemz:
930 resolveSystemZRelocation(Section, Offset, Value, Type, Addend);
933 llvm_unreachable("Unsupported CPU type!");
937 relocation_iterator RuntimeDyldELF::processRelocationRef(
938 unsigned SectionID, relocation_iterator RelI, ObjectImage &Obj,
939 ObjSectionToIDMap &ObjSectionToID, const SymbolTableMap &Symbols,
942 Check(RelI->getType(RelType));
944 Check(getELFRelocationAddend(*RelI, Addend));
945 symbol_iterator Symbol = RelI->getSymbol();
947 // Obtain the symbol name which is referenced in the relocation
948 StringRef TargetName;
949 if (Symbol != Obj.end_symbols())
950 Symbol->getName(TargetName);
951 DEBUG(dbgs() << "\t\tRelType: " << RelType << " Addend: " << Addend
952 << " TargetName: " << TargetName << "\n");
953 RelocationValueRef Value;
954 // First search for the symbol in the local symbol table
955 SymbolTableMap::const_iterator lsi = Symbols.end();
956 SymbolRef::Type SymType = SymbolRef::ST_Unknown;
957 if (Symbol != Obj.end_symbols()) {
958 lsi = Symbols.find(TargetName.data());
959 Symbol->getType(SymType);
961 if (lsi != Symbols.end()) {
962 Value.SectionID = lsi->second.first;
963 Value.Offset = lsi->second.second;
964 Value.Addend = lsi->second.second + Addend;
966 // Search for the symbol in the global symbol table
967 SymbolTableMap::const_iterator gsi = GlobalSymbolTable.end();
968 if (Symbol != Obj.end_symbols())
969 gsi = GlobalSymbolTable.find(TargetName.data());
970 if (gsi != GlobalSymbolTable.end()) {
971 Value.SectionID = gsi->second.first;
972 Value.Offset = gsi->second.second;
973 Value.Addend = gsi->second.second + Addend;
976 case SymbolRef::ST_Debug: {
977 // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously
978 // and can be changed by another developers. Maybe best way is add
979 // a new symbol type ST_Section to SymbolRef and use it.
980 section_iterator si(Obj.end_sections());
981 Symbol->getSection(si);
982 if (si == Obj.end_sections())
983 llvm_unreachable("Symbol section not found, bad object file format!");
984 DEBUG(dbgs() << "\t\tThis is section symbol\n");
985 // Default to 'true' in case isText fails (though it never does).
988 Value.SectionID = findOrEmitSection(Obj, (*si), isCode, ObjSectionToID);
989 Value.Addend = Addend;
992 case SymbolRef::ST_Data:
993 case SymbolRef::ST_Unknown: {
994 Value.SymbolName = TargetName.data();
995 Value.Addend = Addend;
997 // Absolute relocations will have a zero symbol ID (STN_UNDEF), which
998 // will manifest here as a NULL symbol name.
999 // We can set this as a valid (but empty) symbol name, and rely
1000 // on addRelocationForSymbol to handle this.
1001 if (!Value.SymbolName)
1002 Value.SymbolName = "";
1006 llvm_unreachable("Unresolved symbol type!");
1012 Check(RelI->getOffset(Offset));
1014 DEBUG(dbgs() << "\t\tSectionID: " << SectionID << " Offset: " << Offset
1016 if ((Arch == Triple::aarch64 || Arch == Triple::aarch64_be) &&
1017 (RelType == ELF::R_AARCH64_CALL26 || RelType == ELF::R_AARCH64_JUMP26)) {
1018 // This is an AArch64 branch relocation, need to use a stub function.
1019 DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation.");
1020 SectionEntry &Section = Sections[SectionID];
1022 // Look for an existing stub.
1023 StubMap::const_iterator i = Stubs.find(Value);
1024 if (i != Stubs.end()) {
1025 resolveRelocation(Section, Offset, (uint64_t)Section.Address + i->second,
1027 DEBUG(dbgs() << " Stub function found\n");
1029 // Create a new stub function.
1030 DEBUG(dbgs() << " Create a new stub function\n");
1031 Stubs[Value] = Section.StubOffset;
1032 uint8_t *StubTargetAddr =
1033 createStubFunction(Section.Address + Section.StubOffset);
1035 RelocationEntry REmovz_g3(SectionID, StubTargetAddr - Section.Address,
1036 ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend);
1037 RelocationEntry REmovk_g2(SectionID, StubTargetAddr - Section.Address + 4,
1038 ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend);
1039 RelocationEntry REmovk_g1(SectionID, StubTargetAddr - Section.Address + 8,
1040 ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend);
1041 RelocationEntry REmovk_g0(SectionID,
1042 StubTargetAddr - Section.Address + 12,
1043 ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend);
1045 if (Value.SymbolName) {
1046 addRelocationForSymbol(REmovz_g3, Value.SymbolName);
1047 addRelocationForSymbol(REmovk_g2, Value.SymbolName);
1048 addRelocationForSymbol(REmovk_g1, Value.SymbolName);
1049 addRelocationForSymbol(REmovk_g0, Value.SymbolName);
1051 addRelocationForSection(REmovz_g3, Value.SectionID);
1052 addRelocationForSection(REmovk_g2, Value.SectionID);
1053 addRelocationForSection(REmovk_g1, Value.SectionID);
1054 addRelocationForSection(REmovk_g0, Value.SectionID);
1056 resolveRelocation(Section, Offset,
1057 (uint64_t)Section.Address + Section.StubOffset, RelType,
1059 Section.StubOffset += getMaxStubSize();
1061 } else if (Arch == Triple::arm &&
1062 (RelType == ELF::R_ARM_PC24 || RelType == ELF::R_ARM_CALL ||
1063 RelType == ELF::R_ARM_JUMP24)) {
1064 // This is an ARM branch relocation, need to use a stub function.
1065 DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.");
1066 SectionEntry &Section = Sections[SectionID];
1068 // Look for an existing stub.
1069 StubMap::const_iterator i = Stubs.find(Value);
1070 if (i != Stubs.end()) {
1071 resolveRelocation(Section, Offset, (uint64_t)Section.Address + i->second,
1073 DEBUG(dbgs() << " Stub function found\n");
1075 // Create a new stub function.
1076 DEBUG(dbgs() << " Create a new stub function\n");
1077 Stubs[Value] = Section.StubOffset;
1078 uint8_t *StubTargetAddr =
1079 createStubFunction(Section.Address + Section.StubOffset);
1080 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1081 ELF::R_ARM_PRIVATE_0, Value.Addend);
1082 if (Value.SymbolName)
1083 addRelocationForSymbol(RE, Value.SymbolName);
1085 addRelocationForSection(RE, Value.SectionID);
1087 resolveRelocation(Section, Offset,
1088 (uint64_t)Section.Address + Section.StubOffset, RelType,
1090 Section.StubOffset += getMaxStubSize();
1092 } else if ((Arch == Triple::mipsel || Arch == Triple::mips) &&
1093 RelType == ELF::R_MIPS_26) {
1094 // This is an Mips branch relocation, need to use a stub function.
1095 DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
1096 SectionEntry &Section = Sections[SectionID];
1097 uint8_t *Target = Section.Address + Offset;
1098 uint32_t *TargetAddress = (uint32_t *)Target;
1100 // Extract the addend from the instruction.
1101 uint32_t Addend = ((*TargetAddress) & 0x03ffffff) << 2;
1103 Value.Addend += Addend;
1105 // Look up for existing stub.
1106 StubMap::const_iterator i = Stubs.find(Value);
1107 if (i != Stubs.end()) {
1108 RelocationEntry RE(SectionID, Offset, RelType, i->second);
1109 addRelocationForSection(RE, SectionID);
1110 DEBUG(dbgs() << " Stub function found\n");
1112 // Create a new stub function.
1113 DEBUG(dbgs() << " Create a new stub function\n");
1114 Stubs[Value] = Section.StubOffset;
1115 uint8_t *StubTargetAddr =
1116 createStubFunction(Section.Address + Section.StubOffset);
1118 // Creating Hi and Lo relocations for the filled stub instructions.
1119 RelocationEntry REHi(SectionID, StubTargetAddr - Section.Address,
1120 ELF::R_MIPS_UNUSED1, Value.Addend);
1121 RelocationEntry RELo(SectionID, StubTargetAddr - Section.Address + 4,
1122 ELF::R_MIPS_UNUSED2, Value.Addend);
1124 if (Value.SymbolName) {
1125 addRelocationForSymbol(REHi, Value.SymbolName);
1126 addRelocationForSymbol(RELo, Value.SymbolName);
1128 addRelocationForSection(REHi, Value.SectionID);
1129 addRelocationForSection(RELo, Value.SectionID);
1132 RelocationEntry RE(SectionID, Offset, RelType, Section.StubOffset);
1133 addRelocationForSection(RE, SectionID);
1134 Section.StubOffset += getMaxStubSize();
1136 } else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) {
1137 if (RelType == ELF::R_PPC64_REL24) {
1138 // Determine ABI variant in use for this object.
1139 unsigned AbiVariant;
1140 Obj.getObjectFile()->getPlatformFlags(AbiVariant);
1141 AbiVariant &= ELF::EF_PPC64_ABI;
1142 // A PPC branch relocation will need a stub function if the target is
1143 // an external symbol (Symbol::ST_Unknown) or if the target address
1144 // is not within the signed 24-bits branch address.
1145 SectionEntry &Section = Sections[SectionID];
1146 uint8_t *Target = Section.Address + Offset;
1147 bool RangeOverflow = false;
1148 if (SymType != SymbolRef::ST_Unknown) {
1149 if (AbiVariant != 2) {
1150 // In the ELFv1 ABI, a function call may point to the .opd entry,
1151 // so the final symbol value is calculated based on the relocation
1152 // values in the .opd section.
1153 findOPDEntrySection(Obj, ObjSectionToID, Value);
1155 // In the ELFv2 ABI, a function symbol may provide a local entry
1156 // point, which must be used for direct calls.
1158 Symbol->getOther(SymOther);
1159 Value.Addend += ELF::decodePPC64LocalEntryOffset(SymOther);
1161 uint8_t *RelocTarget = Sections[Value.SectionID].Address + Value.Addend;
1162 int32_t delta = static_cast<int32_t>(Target - RelocTarget);
1163 // If it is within 24-bits branch range, just set the branch target
1164 if (SignExtend32<24>(delta) == delta) {
1165 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1166 if (Value.SymbolName)
1167 addRelocationForSymbol(RE, Value.SymbolName);
1169 addRelocationForSection(RE, Value.SectionID);
1171 RangeOverflow = true;
1174 if (SymType == SymbolRef::ST_Unknown || RangeOverflow == true) {
1175 // It is an external symbol (SymbolRef::ST_Unknown) or within a range
1176 // larger than 24-bits.
1177 StubMap::const_iterator i = Stubs.find(Value);
1178 if (i != Stubs.end()) {
1179 // Symbol function stub already created, just relocate to it
1180 resolveRelocation(Section, Offset,
1181 (uint64_t)Section.Address + i->second, RelType, 0);
1182 DEBUG(dbgs() << " Stub function found\n");
1184 // Create a new stub function.
1185 DEBUG(dbgs() << " Create a new stub function\n");
1186 Stubs[Value] = Section.StubOffset;
1187 uint8_t *StubTargetAddr =
1188 createStubFunction(Section.Address + Section.StubOffset,
1190 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1191 ELF::R_PPC64_ADDR64, Value.Addend);
1193 // Generates the 64-bits address loads as exemplified in section
1194 // 4.5.1 in PPC64 ELF ABI. Note that the relocations need to
1195 // apply to the low part of the instructions, so we have to update
1196 // the offset according to the target endianness.
1197 uint64_t StubRelocOffset = StubTargetAddr - Section.Address;
1198 if (!IsTargetLittleEndian)
1199 StubRelocOffset += 2;
1201 RelocationEntry REhst(SectionID, StubRelocOffset + 0,
1202 ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend);
1203 RelocationEntry REhr(SectionID, StubRelocOffset + 4,
1204 ELF::R_PPC64_ADDR16_HIGHER, Value.Addend);
1205 RelocationEntry REh(SectionID, StubRelocOffset + 12,
1206 ELF::R_PPC64_ADDR16_HI, Value.Addend);
1207 RelocationEntry REl(SectionID, StubRelocOffset + 16,
1208 ELF::R_PPC64_ADDR16_LO, Value.Addend);
1210 if (Value.SymbolName) {
1211 addRelocationForSymbol(REhst, Value.SymbolName);
1212 addRelocationForSymbol(REhr, Value.SymbolName);
1213 addRelocationForSymbol(REh, Value.SymbolName);
1214 addRelocationForSymbol(REl, Value.SymbolName);
1216 addRelocationForSection(REhst, Value.SectionID);
1217 addRelocationForSection(REhr, Value.SectionID);
1218 addRelocationForSection(REh, Value.SectionID);
1219 addRelocationForSection(REl, Value.SectionID);
1222 resolveRelocation(Section, Offset,
1223 (uint64_t)Section.Address + Section.StubOffset,
1225 Section.StubOffset += getMaxStubSize();
1227 if (SymType == SymbolRef::ST_Unknown) {
1228 // Restore the TOC for external calls
1229 if (AbiVariant == 2)
1230 writeInt32BE(Target + 4, 0xE8410018); // ld r2,28(r1)
1232 writeInt32BE(Target + 4, 0xE8410028); // ld r2,40(r1)
1235 } else if (RelType == ELF::R_PPC64_TOC16 ||
1236 RelType == ELF::R_PPC64_TOC16_DS ||
1237 RelType == ELF::R_PPC64_TOC16_LO ||
1238 RelType == ELF::R_PPC64_TOC16_LO_DS ||
1239 RelType == ELF::R_PPC64_TOC16_HI ||
1240 RelType == ELF::R_PPC64_TOC16_HA) {
1241 // These relocations are supposed to subtract the TOC address from
1242 // the final value. This does not fit cleanly into the RuntimeDyld
1243 // scheme, since there may be *two* sections involved in determining
1244 // the relocation value (the section of the symbol refered to by the
1245 // relocation, and the TOC section associated with the current module).
1247 // Fortunately, these relocations are currently only ever generated
1248 // refering to symbols that themselves reside in the TOC, which means
1249 // that the two sections are actually the same. Thus they cancel out
1250 // and we can immediately resolve the relocation right now.
1252 case ELF::R_PPC64_TOC16: RelType = ELF::R_PPC64_ADDR16; break;
1253 case ELF::R_PPC64_TOC16_DS: RelType = ELF::R_PPC64_ADDR16_DS; break;
1254 case ELF::R_PPC64_TOC16_LO: RelType = ELF::R_PPC64_ADDR16_LO; break;
1255 case ELF::R_PPC64_TOC16_LO_DS: RelType = ELF::R_PPC64_ADDR16_LO_DS; break;
1256 case ELF::R_PPC64_TOC16_HI: RelType = ELF::R_PPC64_ADDR16_HI; break;
1257 case ELF::R_PPC64_TOC16_HA: RelType = ELF::R_PPC64_ADDR16_HA; break;
1258 default: llvm_unreachable("Wrong relocation type.");
1261 RelocationValueRef TOCValue;
1262 findPPC64TOCSection(Obj, ObjSectionToID, TOCValue);
1263 if (Value.SymbolName || Value.SectionID != TOCValue.SectionID)
1264 llvm_unreachable("Unsupported TOC relocation.");
1265 Value.Addend -= TOCValue.Addend;
1266 resolveRelocation(Sections[SectionID], Offset, Value.Addend, RelType, 0);
1268 // There are two ways to refer to the TOC address directly: either
1269 // via a ELF::R_PPC64_TOC relocation (where both symbol and addend are
1270 // ignored), or via any relocation that refers to the magic ".TOC."
1271 // symbols (in which case the addend is respected).
1272 if (RelType == ELF::R_PPC64_TOC) {
1273 RelType = ELF::R_PPC64_ADDR64;
1274 findPPC64TOCSection(Obj, ObjSectionToID, Value);
1275 } else if (TargetName == ".TOC.") {
1276 findPPC64TOCSection(Obj, ObjSectionToID, Value);
1277 Value.Addend += Addend;
1280 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1282 if (Value.SymbolName)
1283 addRelocationForSymbol(RE, Value.SymbolName);
1285 addRelocationForSection(RE, Value.SectionID);
1287 } else if (Arch == Triple::systemz &&
1288 (RelType == ELF::R_390_PLT32DBL || RelType == ELF::R_390_GOTENT)) {
1289 // Create function stubs for both PLT and GOT references, regardless of
1290 // whether the GOT reference is to data or code. The stub contains the
1291 // full address of the symbol, as needed by GOT references, and the
1292 // executable part only adds an overhead of 8 bytes.
1294 // We could try to conserve space by allocating the code and data
1295 // parts of the stub separately. However, as things stand, we allocate
1296 // a stub for every relocation, so using a GOT in JIT code should be
1297 // no less space efficient than using an explicit constant pool.
1298 DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation.");
1299 SectionEntry &Section = Sections[SectionID];
1301 // Look for an existing stub.
1302 StubMap::const_iterator i = Stubs.find(Value);
1303 uintptr_t StubAddress;
1304 if (i != Stubs.end()) {
1305 StubAddress = uintptr_t(Section.Address) + i->second;
1306 DEBUG(dbgs() << " Stub function found\n");
1308 // Create a new stub function.
1309 DEBUG(dbgs() << " Create a new stub function\n");
1311 uintptr_t BaseAddress = uintptr_t(Section.Address);
1312 uintptr_t StubAlignment = getStubAlignment();
1313 StubAddress = (BaseAddress + Section.StubOffset + StubAlignment - 1) &
1315 unsigned StubOffset = StubAddress - BaseAddress;
1317 Stubs[Value] = StubOffset;
1318 createStubFunction((uint8_t *)StubAddress);
1319 RelocationEntry RE(SectionID, StubOffset + 8, ELF::R_390_64,
1320 Value.Addend - Addend);
1321 if (Value.SymbolName)
1322 addRelocationForSymbol(RE, Value.SymbolName);
1324 addRelocationForSection(RE, Value.SectionID);
1325 Section.StubOffset = StubOffset + getMaxStubSize();
1328 if (RelType == ELF::R_390_GOTENT)
1329 resolveRelocation(Section, Offset, StubAddress + 8, ELF::R_390_PC32DBL,
1332 resolveRelocation(Section, Offset, StubAddress, RelType, Addend);
1333 } else if (Arch == Triple::x86_64 && RelType == ELF::R_X86_64_PLT32) {
1334 // The way the PLT relocations normally work is that the linker allocates
1336 // PLT and this relocation makes a PC-relative call into the PLT. The PLT
1337 // entry will then jump to an address provided by the GOT. On first call,
1339 // GOT address will point back into PLT code that resolves the symbol. After
1340 // the first call, the GOT entry points to the actual function.
1342 // For local functions we're ignoring all of that here and just replacing
1343 // the PLT32 relocation type with PC32, which will translate the relocation
1344 // into a PC-relative call directly to the function. For external symbols we
1345 // can't be sure the function will be within 2^32 bytes of the call site, so
1346 // we need to create a stub, which calls into the GOT. This case is
1347 // equivalent to the usual PLT implementation except that we use the stub
1348 // mechanism in RuntimeDyld (which puts stubs at the end of the section)
1349 // rather than allocating a PLT section.
1350 if (Value.SymbolName) {
1351 // This is a call to an external function.
1352 // Look for an existing stub.
1353 SectionEntry &Section = Sections[SectionID];
1354 StubMap::const_iterator i = Stubs.find(Value);
1355 uintptr_t StubAddress;
1356 if (i != Stubs.end()) {
1357 StubAddress = uintptr_t(Section.Address) + i->second;
1358 DEBUG(dbgs() << " Stub function found\n");
1360 // Create a new stub function (equivalent to a PLT entry).
1361 DEBUG(dbgs() << " Create a new stub function\n");
1363 uintptr_t BaseAddress = uintptr_t(Section.Address);
1364 uintptr_t StubAlignment = getStubAlignment();
1365 StubAddress = (BaseAddress + Section.StubOffset + StubAlignment - 1) &
1367 unsigned StubOffset = StubAddress - BaseAddress;
1368 Stubs[Value] = StubOffset;
1369 createStubFunction((uint8_t *)StubAddress);
1371 // Create a GOT entry for the external function.
1372 GOTEntries.push_back(Value);
1374 // Make our stub function a relative call to the GOT entry.
1375 RelocationEntry RE(SectionID, StubOffset + 2, ELF::R_X86_64_GOTPCREL,
1377 addRelocationForSymbol(RE, Value.SymbolName);
1379 // Bump our stub offset counter
1380 Section.StubOffset = StubOffset + getMaxStubSize();
1383 // Make the target call a call into the stub table.
1384 resolveRelocation(Section, Offset, StubAddress, ELF::R_X86_64_PC32,
1387 RelocationEntry RE(SectionID, Offset, ELF::R_X86_64_PC32, Value.Addend,
1389 addRelocationForSection(RE, Value.SectionID);
1392 if (Arch == Triple::x86_64 && RelType == ELF::R_X86_64_GOTPCREL) {
1393 GOTEntries.push_back(Value);
1395 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend, Value.Offset);
1396 if (Value.SymbolName)
1397 addRelocationForSymbol(RE, Value.SymbolName);
1399 addRelocationForSection(RE, Value.SectionID);
1404 void RuntimeDyldELF::updateGOTEntries(StringRef Name, uint64_t Addr) {
1406 SmallVectorImpl<std::pair<SID, GOTRelocations>>::iterator it;
1407 SmallVectorImpl<std::pair<SID, GOTRelocations>>::iterator end = GOTs.end();
1409 for (it = GOTs.begin(); it != end; ++it) {
1410 GOTRelocations &GOTEntries = it->second;
1411 for (int i = 0, e = GOTEntries.size(); i != e; ++i) {
1412 if (GOTEntries[i].SymbolName != nullptr &&
1413 GOTEntries[i].SymbolName == Name) {
1414 GOTEntries[i].Offset = Addr;
1420 size_t RuntimeDyldELF::getGOTEntrySize() {
1421 // We don't use the GOT in all of these cases, but it's essentially free
1422 // to put them all here.
1425 case Triple::x86_64:
1426 case Triple::aarch64:
1427 case Triple::aarch64_be:
1429 case Triple::ppc64le:
1430 case Triple::systemz:
1431 Result = sizeof(uint64_t);
1437 case Triple::mipsel:
1438 Result = sizeof(uint32_t);
1441 llvm_unreachable("Unsupported CPU type!");
1446 uint64_t RuntimeDyldELF::findGOTEntry(uint64_t LoadAddress, uint64_t Offset) {
1448 const size_t GOTEntrySize = getGOTEntrySize();
1450 SmallVectorImpl<std::pair<SID, GOTRelocations>>::const_iterator it;
1451 SmallVectorImpl<std::pair<SID, GOTRelocations>>::const_iterator end =
1455 for (it = GOTs.begin(); it != end; ++it) {
1456 SID GOTSectionID = it->first;
1457 const GOTRelocations &GOTEntries = it->second;
1459 // Find the matching entry in our vector.
1460 uint64_t SymbolOffset = 0;
1461 for (int i = 0, e = GOTEntries.size(); i != e; ++i) {
1462 if (!GOTEntries[i].SymbolName) {
1463 if (getSectionLoadAddress(GOTEntries[i].SectionID) == LoadAddress &&
1464 GOTEntries[i].Offset == Offset) {
1466 SymbolOffset = GOTEntries[i].Offset;
1470 // GOT entries for external symbols use the addend as the address when
1471 // the external symbol has been resolved.
1472 if (GOTEntries[i].Offset == LoadAddress) {
1474 // Don't use the Addend here. The relocation handler will use it.
1480 if (GOTIndex != -1) {
1481 if (GOTEntrySize == sizeof(uint64_t)) {
1482 uint64_t *LocalGOTAddr = (uint64_t *)getSectionAddress(GOTSectionID);
1483 // Fill in this entry with the address of the symbol being referenced.
1484 LocalGOTAddr[GOTIndex] = LoadAddress + SymbolOffset;
1486 uint32_t *LocalGOTAddr = (uint32_t *)getSectionAddress(GOTSectionID);
1487 // Fill in this entry with the address of the symbol being referenced.
1488 LocalGOTAddr[GOTIndex] = (uint32_t)(LoadAddress + SymbolOffset);
1491 // Calculate the load address of this entry
1492 return getSectionLoadAddress(GOTSectionID) + (GOTIndex * GOTEntrySize);
1496 assert(GOTIndex != -1 && "Unable to find requested GOT entry.");
1500 void RuntimeDyldELF::finalizeLoad(ObjectImage &ObjImg,
1501 ObjSectionToIDMap &SectionMap) {
1502 // If necessary, allocate the global offset table
1504 // Allocate the GOT if necessary
1505 size_t numGOTEntries = GOTEntries.size();
1506 if (numGOTEntries != 0) {
1507 // Allocate memory for the section
1508 unsigned SectionID = Sections.size();
1509 size_t TotalSize = numGOTEntries * getGOTEntrySize();
1510 uint8_t *Addr = MemMgr->allocateDataSection(TotalSize, getGOTEntrySize(),
1511 SectionID, ".got", false);
1513 report_fatal_error("Unable to allocate memory for GOT!");
1515 GOTs.push_back(std::make_pair(SectionID, GOTEntries));
1516 Sections.push_back(SectionEntry(".got", Addr, TotalSize, 0));
1517 // For now, initialize all GOT entries to zero. We'll fill them in as
1518 // needed when GOT-based relocations are applied.
1519 memset(Addr, 0, TotalSize);
1522 report_fatal_error("Unable to allocate memory for GOT!");
1525 // Look for and record the EH frame section.
1526 ObjSectionToIDMap::iterator i, e;
1527 for (i = SectionMap.begin(), e = SectionMap.end(); i != e; ++i) {
1528 const SectionRef &Section = i->first;
1530 Section.getName(Name);
1531 if (Name == ".eh_frame") {
1532 UnregisteredEHFrameSections.push_back(i->second);
1538 bool RuntimeDyldELF::isCompatibleFormat(const ObjectBuffer *Buffer) const {
1539 if (Buffer->getBufferSize() < strlen(ELF::ElfMagic))
1541 return (memcmp(Buffer->getBufferStart(), ELF::ElfMagic,
1542 strlen(ELF::ElfMagic))) == 0;
1545 bool RuntimeDyldELF::isCompatibleFile(const object::ObjectFile *Obj) const {
1546 return Obj->isELF();