1 //===-- RuntimeDyldELF.cpp - Run-time dynamic linker for MC-JIT -*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // Implementation of ELF support for the MC-JIT runtime dynamic linker.
12 //===----------------------------------------------------------------------===//
14 #include "RuntimeDyldELF.h"
15 #include "JITRegistrar.h"
16 #include "ObjectImageCommon.h"
17 #include "llvm/ADT/IntervalMap.h"
18 #include "llvm/ADT/STLExtras.h"
19 #include "llvm/ADT/StringRef.h"
20 #include "llvm/ADT/Triple.h"
21 #include "llvm/ExecutionEngine/ObjectBuffer.h"
22 #include "llvm/ExecutionEngine/ObjectImage.h"
23 #include "llvm/Object/ELFObjectFile.h"
24 #include "llvm/Object/ObjectFile.h"
25 #include "llvm/Support/ELF.h"
26 #include "llvm/Support/Endian.h"
27 #include "llvm/Support/MemoryBuffer.h"
30 using namespace llvm::object;
32 #define DEBUG_TYPE "dyld"
36 static inline std::error_code check(std::error_code Err) {
38 report_fatal_error(Err.message());
43 template <class ELFT> class DyldELFObject : public ELFObjectFile<ELFT> {
44 LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
46 typedef Elf_Shdr_Impl<ELFT> Elf_Shdr;
47 typedef Elf_Sym_Impl<ELFT> Elf_Sym;
48 typedef Elf_Rel_Impl<ELFT, false> Elf_Rel;
49 typedef Elf_Rel_Impl<ELFT, true> Elf_Rela;
51 typedef Elf_Ehdr_Impl<ELFT> Elf_Ehdr;
53 typedef typename ELFDataTypeTypedefHelper<ELFT>::value_type addr_type;
55 std::unique_ptr<ObjectFile> UnderlyingFile;
58 DyldELFObject(std::unique_ptr<ObjectFile> UnderlyingFile,
59 MemoryBufferRef Wrapper, std::error_code &ec);
61 DyldELFObject(MemoryBufferRef Wrapper, std::error_code &ec);
63 void updateSectionAddress(const SectionRef &Sec, uint64_t Addr);
64 void updateSymbolAddress(const SymbolRef &Sym, uint64_t Addr);
66 // Methods for type inquiry through isa, cast and dyn_cast
67 static inline bool classof(const Binary *v) {
68 return (isa<ELFObjectFile<ELFT>>(v) &&
69 classof(cast<ELFObjectFile<ELFT>>(v)));
71 static inline bool classof(const ELFObjectFile<ELFT> *v) {
72 return v->isDyldType();
76 template <class ELFT> class ELFObjectImage : public ObjectImageCommon {
80 ELFObjectImage(std::unique_ptr<ObjectBuffer> Input,
81 std::unique_ptr<DyldELFObject<ELFT>> Obj)
82 : ObjectImageCommon(std::move(Input), std::move(Obj)), Registered(false) {
85 virtual ~ELFObjectImage() {
87 deregisterWithDebugger();
90 // Subclasses can override these methods to update the image with loaded
91 // addresses for sections and common symbols
92 void updateSectionAddress(const SectionRef &Sec, uint64_t Addr) override {
93 static_cast<DyldELFObject<ELFT>*>(getObjectFile())
94 ->updateSectionAddress(Sec, Addr);
97 void updateSymbolAddress(const SymbolRef &Sym, uint64_t Addr) override {
98 static_cast<DyldELFObject<ELFT>*>(getObjectFile())
99 ->updateSymbolAddress(Sym, Addr);
102 void registerWithDebugger() override {
103 JITRegistrar::getGDBRegistrar().registerObject(*Buffer);
106 void deregisterWithDebugger() override {
107 JITRegistrar::getGDBRegistrar().deregisterObject(*Buffer);
111 // The MemoryBuffer passed into this constructor is just a wrapper around the
112 // actual memory. Ultimately, the Binary parent class will take ownership of
113 // this MemoryBuffer object but not the underlying memory.
114 template <class ELFT>
115 DyldELFObject<ELFT>::DyldELFObject(MemoryBufferRef Wrapper, std::error_code &EC)
116 : ELFObjectFile<ELFT>(Wrapper, EC) {
117 this->isDyldELFObject = true;
120 template <class ELFT>
121 DyldELFObject<ELFT>::DyldELFObject(std::unique_ptr<ObjectFile> UnderlyingFile,
122 MemoryBufferRef Wrapper, std::error_code &EC)
123 : ELFObjectFile<ELFT>(Wrapper, EC),
124 UnderlyingFile(std::move(UnderlyingFile)) {
125 this->isDyldELFObject = true;
128 template <class ELFT>
129 void DyldELFObject<ELFT>::updateSectionAddress(const SectionRef &Sec,
131 DataRefImpl ShdrRef = Sec.getRawDataRefImpl();
133 const_cast<Elf_Shdr *>(reinterpret_cast<const Elf_Shdr *>(ShdrRef.p));
135 // This assumes the address passed in matches the target address bitness
136 // The template-based type cast handles everything else.
137 shdr->sh_addr = static_cast<addr_type>(Addr);
140 template <class ELFT>
141 void DyldELFObject<ELFT>::updateSymbolAddress(const SymbolRef &SymRef,
144 Elf_Sym *sym = const_cast<Elf_Sym *>(
145 ELFObjectFile<ELFT>::getSymbol(SymRef.getRawDataRefImpl()));
147 // This assumes the address passed in matches the target address bitness
148 // The template-based type cast handles everything else.
149 sym->st_value = static_cast<addr_type>(Addr);
156 void RuntimeDyldELF::registerEHFrames() {
159 for (int i = 0, e = UnregisteredEHFrameSections.size(); i != e; ++i) {
160 SID EHFrameSID = UnregisteredEHFrameSections[i];
161 uint8_t *EHFrameAddr = Sections[EHFrameSID].Address;
162 uint64_t EHFrameLoadAddr = Sections[EHFrameSID].LoadAddress;
163 size_t EHFrameSize = Sections[EHFrameSID].Size;
164 MemMgr->registerEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
165 RegisteredEHFrameSections.push_back(EHFrameSID);
167 UnregisteredEHFrameSections.clear();
170 void RuntimeDyldELF::deregisterEHFrames() {
173 for (int i = 0, e = RegisteredEHFrameSections.size(); i != e; ++i) {
174 SID EHFrameSID = RegisteredEHFrameSections[i];
175 uint8_t *EHFrameAddr = Sections[EHFrameSID].Address;
176 uint64_t EHFrameLoadAddr = Sections[EHFrameSID].LoadAddress;
177 size_t EHFrameSize = Sections[EHFrameSID].Size;
178 MemMgr->deregisterEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
180 RegisteredEHFrameSections.clear();
184 RuntimeDyldELF::createObjectImageFromFile(std::unique_ptr<object::ObjectFile> ObjFile) {
189 MemoryBufferRef Buffer = ObjFile->getMemoryBufferRef();
191 if (ObjFile->getBytesInAddress() == 4 && ObjFile->isLittleEndian()) {
193 llvm::make_unique<DyldELFObject<ELFType<support::little, 2, false>>>(
194 std::move(ObjFile), 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), 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), 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), Buffer, ec);
211 return new ELFObjectImage<ELFType<support::little, 2, true>>(
212 nullptr, std::move(Obj));
214 llvm_unreachable("Unexpected ELF format");
217 std::unique_ptr<ObjectImage>
218 RuntimeDyldELF::createObjectImage(std::unique_ptr<ObjectBuffer> Buffer) {
219 if (Buffer->getBufferSize() < ELF::EI_NIDENT)
220 llvm_unreachable("Unexpected ELF object size");
221 std::pair<unsigned char, unsigned char> Ident =
222 std::make_pair((uint8_t)Buffer->getBufferStart()[ELF::EI_CLASS],
223 (uint8_t)Buffer->getBufferStart()[ELF::EI_DATA]);
226 MemoryBufferRef Buf = Buffer->getMemBuffer();
228 if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2LSB) {
230 llvm::make_unique<DyldELFObject<ELFType<support::little, 4, false>>>(
232 return llvm::make_unique<
233 ELFObjectImage<ELFType<support::little, 4, false>>>(std::move(Buffer),
236 if (Ident.first == ELF::ELFCLASS32 && Ident.second == ELF::ELFDATA2MSB) {
238 llvm::make_unique<DyldELFObject<ELFType<support::big, 4, false>>>(Buf,
240 return llvm::make_unique<ELFObjectImage<ELFType<support::big, 4, false>>>(
241 std::move(Buffer), std::move(Obj));
243 if (Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2MSB) {
244 auto Obj = llvm::make_unique<DyldELFObject<ELFType<support::big, 8, true>>>(
246 return llvm::make_unique<ELFObjectImage<ELFType<support::big, 8, true>>>(
247 std::move(Buffer), std::move(Obj));
249 assert(Ident.first == ELF::ELFCLASS64 && Ident.second == ELF::ELFDATA2LSB &&
250 "Unexpected ELF format");
252 llvm::make_unique<DyldELFObject<ELFType<support::little, 8, true>>>(Buf,
254 return llvm::make_unique<ELFObjectImage<ELFType<support::little, 8, true>>>(
255 std::move(Buffer), std::move(Obj));
258 RuntimeDyldELF::~RuntimeDyldELF() {}
260 void RuntimeDyldELF::resolveX86_64Relocation(const SectionEntry &Section,
261 uint64_t Offset, uint64_t Value,
262 uint32_t Type, int64_t Addend,
263 uint64_t SymOffset) {
266 llvm_unreachable("Relocation type not implemented yet!");
268 case ELF::R_X86_64_64: {
269 support::ulittle64_t::ref(Section.Address + Offset) = Value + Addend;
270 DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend)) << " at "
271 << format("%p\n", Section.Address + Offset));
274 case ELF::R_X86_64_32:
275 case ELF::R_X86_64_32S: {
277 assert((Type == ELF::R_X86_64_32 && (Value <= UINT32_MAX)) ||
278 (Type == ELF::R_X86_64_32S &&
279 ((int64_t)Value <= INT32_MAX && (int64_t)Value >= INT32_MIN)));
280 uint32_t TruncatedAddr = (Value & 0xFFFFFFFF);
281 support::ulittle32_t::ref(Section.Address + Offset) = TruncatedAddr;
282 DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr) << " at "
283 << format("%p\n", Section.Address + Offset));
286 case ELF::R_X86_64_GOTPCREL: {
287 // findGOTEntry returns the 'G + GOT' part of the relocation calculation
288 // based on the load/target address of the GOT (not the current/local addr).
289 uint64_t GOTAddr = findGOTEntry(Value, SymOffset);
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 support::ulittle32_t::ref(Section.Address + Offset) = 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 support::ulittle32_t::ref Placeholder(
304 (void *)(Section.ObjAddress + Offset));
305 uint64_t FinalAddress = Section.LoadAddress + Offset;
306 int64_t RealOffset = Placeholder + Value + Addend - FinalAddress;
307 assert(RealOffset <= INT32_MAX && RealOffset >= INT32_MIN);
308 int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
309 support::ulittle32_t::ref(Section.Address + Offset) = TruncOffset;
312 case ELF::R_X86_64_PC64: {
313 // Get the placeholder value from the generated object since
314 // a previous relocation attempt may have overwritten the loaded version
315 support::ulittle64_t::ref Placeholder(
316 (void *)(Section.ObjAddress + Offset));
317 uint64_t FinalAddress = Section.LoadAddress + Offset;
318 support::ulittle64_t::ref(Section.Address + Offset) =
319 Placeholder + Value + Addend - FinalAddress;
325 void RuntimeDyldELF::resolveX86Relocation(const SectionEntry &Section,
326 uint64_t Offset, uint32_t Value,
327 uint32_t Type, int32_t Addend) {
329 case ELF::R_386_32: {
330 // Get the placeholder value from the generated object since
331 // a previous relocation attempt may have overwritten the loaded version
332 support::ulittle32_t::ref Placeholder(
333 (void *)(Section.ObjAddress + Offset));
334 support::ulittle32_t::ref(Section.Address + Offset) =
335 Placeholder + Value + Addend;
338 case ELF::R_386_PC32: {
339 // Get the placeholder value from the generated object since
340 // a previous relocation attempt may have overwritten the loaded version
341 support::ulittle32_t::ref Placeholder(
342 (void *)(Section.ObjAddress + Offset));
343 uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
344 uint32_t RealOffset = Placeholder + Value + Addend - FinalAddress;
345 support::ulittle32_t::ref(Section.Address + Offset) = RealOffset;
349 // There are other relocation types, but it appears these are the
350 // only ones currently used by the LLVM ELF object writer
351 llvm_unreachable("Relocation type not implemented yet!");
356 void RuntimeDyldELF::resolveAArch64Relocation(const SectionEntry &Section,
357 uint64_t Offset, uint64_t Value,
358 uint32_t Type, int64_t Addend) {
359 uint32_t *TargetPtr = reinterpret_cast<uint32_t *>(Section.Address + Offset);
360 uint64_t FinalAddress = Section.LoadAddress + Offset;
362 DEBUG(dbgs() << "resolveAArch64Relocation, LocalAddress: 0x"
363 << format("%llx", Section.Address + Offset)
364 << " FinalAddress: 0x" << format("%llx", FinalAddress)
365 << " Value: 0x" << format("%llx", Value) << " Type: 0x"
366 << format("%x", Type) << " Addend: 0x" << format("%llx", Addend)
371 llvm_unreachable("Relocation type not implemented yet!");
373 case ELF::R_AARCH64_ABS64: {
374 uint64_t *TargetPtr =
375 reinterpret_cast<uint64_t *>(Section.Address + Offset);
376 *TargetPtr = Value + Addend;
379 case ELF::R_AARCH64_PREL32: {
380 uint64_t Result = Value + Addend - FinalAddress;
381 assert(static_cast<int64_t>(Result) >= INT32_MIN &&
382 static_cast<int64_t>(Result) <= UINT32_MAX);
383 *TargetPtr = static_cast<uint32_t>(Result & 0xffffffffU);
386 case ELF::R_AARCH64_CALL26: // fallthrough
387 case ELF::R_AARCH64_JUMP26: {
388 // Operation: S+A-P. Set Call or B immediate value to bits fff_fffc of the
390 uint64_t BranchImm = Value + Addend - FinalAddress;
392 // "Check that -2^27 <= result < 2^27".
393 assert(-(1LL << 27) <= static_cast<int64_t>(BranchImm) &&
394 static_cast<int64_t>(BranchImm) < (1LL << 27));
396 // AArch64 code is emitted with .rela relocations. The data already in any
397 // bits affected by the relocation on entry is garbage.
398 *TargetPtr &= 0xfc000000U;
399 // Immediate goes in bits 25:0 of B and BL.
400 *TargetPtr |= static_cast<uint32_t>(BranchImm & 0xffffffcU) >> 2;
403 case ELF::R_AARCH64_MOVW_UABS_G3: {
404 uint64_t Result = Value + Addend;
406 // AArch64 code is emitted with .rela relocations. The data already in any
407 // bits affected by the relocation on entry is garbage.
408 *TargetPtr &= 0xffe0001fU;
409 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
410 *TargetPtr |= Result >> (48 - 5);
411 // Shift must be "lsl #48", in bits 22:21
412 assert((*TargetPtr >> 21 & 0x3) == 3 && "invalid shift for relocation");
415 case ELF::R_AARCH64_MOVW_UABS_G2_NC: {
416 uint64_t Result = Value + Addend;
418 // AArch64 code is emitted with .rela relocations. The data already in any
419 // bits affected by the relocation on entry is garbage.
420 *TargetPtr &= 0xffe0001fU;
421 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
422 *TargetPtr |= ((Result & 0xffff00000000ULL) >> (32 - 5));
423 // Shift must be "lsl #32", in bits 22:21
424 assert((*TargetPtr >> 21 & 0x3) == 2 && "invalid shift for relocation");
427 case ELF::R_AARCH64_MOVW_UABS_G1_NC: {
428 uint64_t Result = Value + Addend;
430 // AArch64 code is emitted with .rela relocations. The data already in any
431 // bits affected by the relocation on entry is garbage.
432 *TargetPtr &= 0xffe0001fU;
433 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
434 *TargetPtr |= ((Result & 0xffff0000U) >> (16 - 5));
435 // Shift must be "lsl #16", in bits 22:2
436 assert((*TargetPtr >> 21 & 0x3) == 1 && "invalid shift for relocation");
439 case ELF::R_AARCH64_MOVW_UABS_G0_NC: {
440 uint64_t Result = Value + Addend;
442 // AArch64 code is emitted with .rela relocations. The data already in any
443 // bits affected by the relocation on entry is garbage.
444 *TargetPtr &= 0xffe0001fU;
445 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
446 *TargetPtr |= ((Result & 0xffffU) << 5);
447 // Shift must be "lsl #0", in bits 22:21.
448 assert((*TargetPtr >> 21 & 0x3) == 0 && "invalid shift for relocation");
451 case ELF::R_AARCH64_ADR_PREL_PG_HI21: {
452 // Operation: Page(S+A) - Page(P)
454 ((Value + Addend) & ~0xfffULL) - (FinalAddress & ~0xfffULL);
456 // Check that -2^32 <= X < 2^32
457 assert(static_cast<int64_t>(Result) >= (-1LL << 32) &&
458 static_cast<int64_t>(Result) < (1LL << 32) &&
459 "overflow check failed for relocation");
461 // AArch64 code is emitted with .rela relocations. The data already in any
462 // bits affected by the relocation on entry is garbage.
463 *TargetPtr &= 0x9f00001fU;
464 // Immediate goes in bits 30:29 + 5:23 of ADRP instruction, taken
465 // from bits 32:12 of X.
466 *TargetPtr |= ((Result & 0x3000U) << (29 - 12));
467 *TargetPtr |= ((Result & 0x1ffffc000ULL) >> (14 - 5));
470 case ELF::R_AARCH64_LDST32_ABS_LO12_NC: {
472 uint64_t Result = Value + Addend;
474 // AArch64 code is emitted with .rela relocations. The data already in any
475 // bits affected by the relocation on entry is garbage.
476 *TargetPtr &= 0xffc003ffU;
477 // Immediate goes in bits 21:10 of LD/ST instruction, taken
478 // from bits 11:2 of X
479 *TargetPtr |= ((Result & 0xffc) << (10 - 2));
482 case ELF::R_AARCH64_LDST64_ABS_LO12_NC: {
484 uint64_t Result = Value + Addend;
486 // AArch64 code is emitted with .rela relocations. The data already in any
487 // bits affected by the relocation on entry is garbage.
488 *TargetPtr &= 0xffc003ffU;
489 // Immediate goes in bits 21:10 of LD/ST instruction, taken
490 // from bits 11:3 of X
491 *TargetPtr |= ((Result & 0xff8) << (10 - 3));
497 void RuntimeDyldELF::resolveARMRelocation(const SectionEntry &Section,
498 uint64_t Offset, uint32_t Value,
499 uint32_t Type, int32_t Addend) {
500 // TODO: Add Thumb relocations.
501 uint32_t *Placeholder =
502 reinterpret_cast<uint32_t *>(Section.ObjAddress + Offset);
503 uint32_t *TargetPtr = (uint32_t *)(Section.Address + Offset);
504 uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
507 DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: "
508 << Section.Address + Offset
509 << " FinalAddress: " << format("%p", FinalAddress) << " Value: "
510 << format("%x", Value) << " Type: " << format("%x", Type)
511 << " Addend: " << format("%x", Addend) << "\n");
515 llvm_unreachable("Not implemented relocation type!");
517 case ELF::R_ARM_NONE:
519 // Write a 32bit value to relocation address, taking into account the
520 // implicit addend encoded in the target.
521 case ELF::R_ARM_PREL31:
522 case ELF::R_ARM_TARGET1:
523 case ELF::R_ARM_ABS32:
524 *TargetPtr = *Placeholder + Value;
526 // Write first 16 bit of 32 bit value to the mov instruction.
527 // Last 4 bit should be shifted.
528 case ELF::R_ARM_MOVW_ABS_NC:
529 // We are not expecting any other addend in the relocation address.
530 // Using 0x000F0FFF because MOVW has its 16 bit immediate split into 2
531 // non-contiguous fields.
532 assert((*Placeholder & 0x000F0FFF) == 0);
533 Value = Value & 0xFFFF;
534 *TargetPtr = *Placeholder | (Value & 0xFFF);
535 *TargetPtr |= ((Value >> 12) & 0xF) << 16;
537 // Write last 16 bit of 32 bit value to the mov instruction.
538 // Last 4 bit should be shifted.
539 case ELF::R_ARM_MOVT_ABS:
540 // We are not expecting any other addend in the relocation address.
541 // Use 0x000F0FFF for the same reason as R_ARM_MOVW_ABS_NC.
542 assert((*Placeholder & 0x000F0FFF) == 0);
544 Value = (Value >> 16) & 0xFFFF;
545 *TargetPtr = *Placeholder | (Value & 0xFFF);
546 *TargetPtr |= ((Value >> 12) & 0xF) << 16;
548 // Write 24 bit relative value to the branch instruction.
549 case ELF::R_ARM_PC24: // Fall through.
550 case ELF::R_ARM_CALL: // Fall through.
551 case ELF::R_ARM_JUMP24: {
552 int32_t RelValue = static_cast<int32_t>(Value - FinalAddress - 8);
553 RelValue = (RelValue & 0x03FFFFFC) >> 2;
554 assert((*TargetPtr & 0xFFFFFF) == 0xFFFFFE);
555 *TargetPtr &= 0xFF000000;
556 *TargetPtr |= RelValue;
559 case ELF::R_ARM_PRIVATE_0:
560 // This relocation is reserved by the ARM ELF ABI for internal use. We
561 // appropriate it here to act as an R_ARM_ABS32 without any addend for use
562 // in the stubs created during JIT (which can't put an addend into the
563 // original object file).
569 void RuntimeDyldELF::resolveMIPSRelocation(const SectionEntry &Section,
570 uint64_t Offset, uint32_t Value,
571 uint32_t Type, int32_t Addend) {
572 uint32_t *Placeholder =
573 reinterpret_cast<uint32_t *>(Section.ObjAddress + Offset);
574 uint32_t *TargetPtr = (uint32_t *)(Section.Address + Offset);
577 DEBUG(dbgs() << "resolveMipselocation, LocalAddress: "
578 << Section.Address + Offset << " FinalAddress: "
579 << format("%p", Section.LoadAddress + Offset) << " Value: "
580 << format("%x", Value) << " Type: " << format("%x", Type)
581 << " Addend: " << format("%x", Addend) << "\n");
585 llvm_unreachable("Not implemented relocation type!");
588 *TargetPtr = Value + (*Placeholder);
591 *TargetPtr = ((*Placeholder) & 0xfc000000) | ((Value & 0x0fffffff) >> 2);
593 case ELF::R_MIPS_HI16:
594 // Get the higher 16-bits. Also add 1 if bit 15 is 1.
595 Value += ((*Placeholder) & 0x0000ffff) << 16;
597 ((*Placeholder) & 0xffff0000) | (((Value + 0x8000) >> 16) & 0xffff);
599 case ELF::R_MIPS_LO16:
600 Value += ((*Placeholder) & 0x0000ffff);
601 *TargetPtr = ((*Placeholder) & 0xffff0000) | (Value & 0xffff);
603 case ELF::R_MIPS_UNUSED1:
604 // Similar to ELF::R_ARM_PRIVATE_0, R_MIPS_UNUSED1 and R_MIPS_UNUSED2
605 // are used for internal JIT purpose. These relocations are similar to
606 // R_MIPS_HI16 and R_MIPS_LO16, but they do not take any addend into
609 ((*TargetPtr) & 0xffff0000) | (((Value + 0x8000) >> 16) & 0xffff);
611 case ELF::R_MIPS_UNUSED2:
612 *TargetPtr = ((*TargetPtr) & 0xffff0000) | (Value & 0xffff);
617 // Return the .TOC. section and offset.
618 void RuntimeDyldELF::findPPC64TOCSection(ObjectImage &Obj,
619 ObjSectionToIDMap &LocalSections,
620 RelocationValueRef &Rel) {
621 // Set a default SectionID in case we do not find a TOC section below.
622 // This may happen for references to TOC base base (sym@toc, .odp
623 // relocation) without a .toc directive. In this case just use the
624 // first section (which is usually the .odp) since the code won't
625 // reference the .toc base directly.
626 Rel.SymbolName = NULL;
629 // The TOC consists of sections .got, .toc, .tocbss, .plt in that
630 // order. The TOC starts where the first of these sections starts.
631 for (section_iterator si = Obj.begin_sections(), se = Obj.end_sections();
634 StringRef SectionName;
635 check(si->getName(SectionName));
637 if (SectionName == ".got"
638 || SectionName == ".toc"
639 || SectionName == ".tocbss"
640 || SectionName == ".plt") {
641 Rel.SectionID = findOrEmitSection(Obj, *si, false, LocalSections);
646 // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000
647 // thus permitting a full 64 Kbytes segment.
651 // Returns the sections and offset associated with the ODP entry referenced
653 void RuntimeDyldELF::findOPDEntrySection(ObjectImage &Obj,
654 ObjSectionToIDMap &LocalSections,
655 RelocationValueRef &Rel) {
656 // Get the ELF symbol value (st_value) to compare with Relocation offset in
658 for (section_iterator si = Obj.begin_sections(), se = Obj.end_sections();
660 section_iterator RelSecI = si->getRelocatedSection();
661 if (RelSecI == Obj.end_sections())
664 StringRef RelSectionName;
665 check(RelSecI->getName(RelSectionName));
666 if (RelSectionName != ".opd")
669 for (relocation_iterator i = si->relocation_begin(),
670 e = si->relocation_end();
672 // The R_PPC64_ADDR64 relocation indicates the first field
675 check(i->getType(TypeFunc));
676 if (TypeFunc != ELF::R_PPC64_ADDR64) {
681 uint64_t TargetSymbolOffset;
682 symbol_iterator TargetSymbol = i->getSymbol();
683 check(i->getOffset(TargetSymbolOffset));
685 check(getELFRelocationAddend(*i, Addend));
691 // Just check if following relocation is a R_PPC64_TOC
693 check(i->getType(TypeTOC));
694 if (TypeTOC != ELF::R_PPC64_TOC)
697 // Finally compares the Symbol value and the target symbol offset
698 // to check if this .opd entry refers to the symbol the relocation
700 if (Rel.Addend != (int64_t)TargetSymbolOffset)
703 section_iterator tsi(Obj.end_sections());
704 check(TargetSymbol->getSection(tsi));
705 bool IsCode = tsi->isText();
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 bool isCode = si->isText();
986 Value.SectionID = findOrEmitSection(Obj, (*si), isCode, ObjSectionToID);
987 Value.Addend = Addend;
990 case SymbolRef::ST_Data:
991 case SymbolRef::ST_Unknown: {
992 Value.SymbolName = TargetName.data();
993 Value.Addend = Addend;
995 // Absolute relocations will have a zero symbol ID (STN_UNDEF), which
996 // will manifest here as a NULL symbol name.
997 // We can set this as a valid (but empty) symbol name, and rely
998 // on addRelocationForSymbol to handle this.
999 if (!Value.SymbolName)
1000 Value.SymbolName = "";
1004 llvm_unreachable("Unresolved symbol type!");
1010 Check(RelI->getOffset(Offset));
1012 DEBUG(dbgs() << "\t\tSectionID: " << SectionID << " Offset: " << Offset
1014 if ((Arch == Triple::aarch64 || Arch == Triple::aarch64_be) &&
1015 (RelType == ELF::R_AARCH64_CALL26 || RelType == ELF::R_AARCH64_JUMP26)) {
1016 // This is an AArch64 branch relocation, need to use a stub function.
1017 DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation.");
1018 SectionEntry &Section = Sections[SectionID];
1020 // Look for an existing stub.
1021 StubMap::const_iterator i = Stubs.find(Value);
1022 if (i != Stubs.end()) {
1023 resolveRelocation(Section, Offset, (uint64_t)Section.Address + i->second,
1025 DEBUG(dbgs() << " Stub function found\n");
1027 // Create a new stub function.
1028 DEBUG(dbgs() << " Create a new stub function\n");
1029 Stubs[Value] = Section.StubOffset;
1030 uint8_t *StubTargetAddr =
1031 createStubFunction(Section.Address + Section.StubOffset);
1033 RelocationEntry REmovz_g3(SectionID, StubTargetAddr - Section.Address,
1034 ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend);
1035 RelocationEntry REmovk_g2(SectionID, StubTargetAddr - Section.Address + 4,
1036 ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend);
1037 RelocationEntry REmovk_g1(SectionID, StubTargetAddr - Section.Address + 8,
1038 ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend);
1039 RelocationEntry REmovk_g0(SectionID,
1040 StubTargetAddr - Section.Address + 12,
1041 ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend);
1043 if (Value.SymbolName) {
1044 addRelocationForSymbol(REmovz_g3, Value.SymbolName);
1045 addRelocationForSymbol(REmovk_g2, Value.SymbolName);
1046 addRelocationForSymbol(REmovk_g1, Value.SymbolName);
1047 addRelocationForSymbol(REmovk_g0, Value.SymbolName);
1049 addRelocationForSection(REmovz_g3, Value.SectionID);
1050 addRelocationForSection(REmovk_g2, Value.SectionID);
1051 addRelocationForSection(REmovk_g1, Value.SectionID);
1052 addRelocationForSection(REmovk_g0, Value.SectionID);
1054 resolveRelocation(Section, Offset,
1055 (uint64_t)Section.Address + Section.StubOffset, RelType,
1057 Section.StubOffset += getMaxStubSize();
1059 } else if (Arch == Triple::arm &&
1060 (RelType == ELF::R_ARM_PC24 || RelType == ELF::R_ARM_CALL ||
1061 RelType == ELF::R_ARM_JUMP24)) {
1062 // This is an ARM branch relocation, need to use a stub function.
1063 DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.");
1064 SectionEntry &Section = Sections[SectionID];
1066 // Look for an existing stub.
1067 StubMap::const_iterator i = Stubs.find(Value);
1068 if (i != Stubs.end()) {
1069 resolveRelocation(Section, Offset, (uint64_t)Section.Address + i->second,
1071 DEBUG(dbgs() << " Stub function found\n");
1073 // Create a new stub function.
1074 DEBUG(dbgs() << " Create a new stub function\n");
1075 Stubs[Value] = Section.StubOffset;
1076 uint8_t *StubTargetAddr =
1077 createStubFunction(Section.Address + Section.StubOffset);
1078 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1079 ELF::R_ARM_PRIVATE_0, Value.Addend);
1080 if (Value.SymbolName)
1081 addRelocationForSymbol(RE, Value.SymbolName);
1083 addRelocationForSection(RE, Value.SectionID);
1085 resolveRelocation(Section, Offset,
1086 (uint64_t)Section.Address + Section.StubOffset, RelType,
1088 Section.StubOffset += getMaxStubSize();
1090 } else if ((Arch == Triple::mipsel || Arch == Triple::mips) &&
1091 RelType == ELF::R_MIPS_26) {
1092 // This is an Mips branch relocation, need to use a stub function.
1093 DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
1094 SectionEntry &Section = Sections[SectionID];
1095 uint8_t *Target = Section.Address + Offset;
1096 uint32_t *TargetAddress = (uint32_t *)Target;
1098 // Extract the addend from the instruction.
1099 uint32_t Addend = ((*TargetAddress) & 0x03ffffff) << 2;
1101 Value.Addend += Addend;
1103 // Look up for existing stub.
1104 StubMap::const_iterator i = Stubs.find(Value);
1105 if (i != Stubs.end()) {
1106 RelocationEntry RE(SectionID, Offset, RelType, i->second);
1107 addRelocationForSection(RE, SectionID);
1108 DEBUG(dbgs() << " Stub function found\n");
1110 // Create a new stub function.
1111 DEBUG(dbgs() << " Create a new stub function\n");
1112 Stubs[Value] = Section.StubOffset;
1113 uint8_t *StubTargetAddr =
1114 createStubFunction(Section.Address + Section.StubOffset);
1116 // Creating Hi and Lo relocations for the filled stub instructions.
1117 RelocationEntry REHi(SectionID, StubTargetAddr - Section.Address,
1118 ELF::R_MIPS_UNUSED1, Value.Addend);
1119 RelocationEntry RELo(SectionID, StubTargetAddr - Section.Address + 4,
1120 ELF::R_MIPS_UNUSED2, Value.Addend);
1122 if (Value.SymbolName) {
1123 addRelocationForSymbol(REHi, Value.SymbolName);
1124 addRelocationForSymbol(RELo, Value.SymbolName);
1126 addRelocationForSection(REHi, Value.SectionID);
1127 addRelocationForSection(RELo, Value.SectionID);
1130 RelocationEntry RE(SectionID, Offset, RelType, Section.StubOffset);
1131 addRelocationForSection(RE, SectionID);
1132 Section.StubOffset += getMaxStubSize();
1134 } else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) {
1135 if (RelType == ELF::R_PPC64_REL24) {
1136 // Determine ABI variant in use for this object.
1137 unsigned AbiVariant;
1138 Obj.getObjectFile()->getPlatformFlags(AbiVariant);
1139 AbiVariant &= ELF::EF_PPC64_ABI;
1140 // A PPC branch relocation will need a stub function if the target is
1141 // an external symbol (Symbol::ST_Unknown) or if the target address
1142 // is not within the signed 24-bits branch address.
1143 SectionEntry &Section = Sections[SectionID];
1144 uint8_t *Target = Section.Address + Offset;
1145 bool RangeOverflow = false;
1146 if (SymType != SymbolRef::ST_Unknown) {
1147 if (AbiVariant != 2) {
1148 // In the ELFv1 ABI, a function call may point to the .opd entry,
1149 // so the final symbol value is calculated based on the relocation
1150 // values in the .opd section.
1151 findOPDEntrySection(Obj, ObjSectionToID, Value);
1153 // In the ELFv2 ABI, a function symbol may provide a local entry
1154 // point, which must be used for direct calls.
1156 Symbol->getOther(SymOther);
1157 Value.Addend += ELF::decodePPC64LocalEntryOffset(SymOther);
1159 uint8_t *RelocTarget = Sections[Value.SectionID].Address + Value.Addend;
1160 int32_t delta = static_cast<int32_t>(Target - RelocTarget);
1161 // If it is within 24-bits branch range, just set the branch target
1162 if (SignExtend32<24>(delta) == delta) {
1163 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1164 if (Value.SymbolName)
1165 addRelocationForSymbol(RE, Value.SymbolName);
1167 addRelocationForSection(RE, Value.SectionID);
1169 RangeOverflow = true;
1172 if (SymType == SymbolRef::ST_Unknown || RangeOverflow == true) {
1173 // It is an external symbol (SymbolRef::ST_Unknown) or within a range
1174 // larger than 24-bits.
1175 StubMap::const_iterator i = Stubs.find(Value);
1176 if (i != Stubs.end()) {
1177 // Symbol function stub already created, just relocate to it
1178 resolveRelocation(Section, Offset,
1179 (uint64_t)Section.Address + i->second, RelType, 0);
1180 DEBUG(dbgs() << " Stub function found\n");
1182 // Create a new stub function.
1183 DEBUG(dbgs() << " Create a new stub function\n");
1184 Stubs[Value] = Section.StubOffset;
1185 uint8_t *StubTargetAddr =
1186 createStubFunction(Section.Address + Section.StubOffset,
1188 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1189 ELF::R_PPC64_ADDR64, Value.Addend);
1191 // Generates the 64-bits address loads as exemplified in section
1192 // 4.5.1 in PPC64 ELF ABI. Note that the relocations need to
1193 // apply to the low part of the instructions, so we have to update
1194 // the offset according to the target endianness.
1195 uint64_t StubRelocOffset = StubTargetAddr - Section.Address;
1196 if (!IsTargetLittleEndian)
1197 StubRelocOffset += 2;
1199 RelocationEntry REhst(SectionID, StubRelocOffset + 0,
1200 ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend);
1201 RelocationEntry REhr(SectionID, StubRelocOffset + 4,
1202 ELF::R_PPC64_ADDR16_HIGHER, Value.Addend);
1203 RelocationEntry REh(SectionID, StubRelocOffset + 12,
1204 ELF::R_PPC64_ADDR16_HI, Value.Addend);
1205 RelocationEntry REl(SectionID, StubRelocOffset + 16,
1206 ELF::R_PPC64_ADDR16_LO, Value.Addend);
1208 if (Value.SymbolName) {
1209 addRelocationForSymbol(REhst, Value.SymbolName);
1210 addRelocationForSymbol(REhr, Value.SymbolName);
1211 addRelocationForSymbol(REh, Value.SymbolName);
1212 addRelocationForSymbol(REl, Value.SymbolName);
1214 addRelocationForSection(REhst, Value.SectionID);
1215 addRelocationForSection(REhr, Value.SectionID);
1216 addRelocationForSection(REh, Value.SectionID);
1217 addRelocationForSection(REl, Value.SectionID);
1220 resolveRelocation(Section, Offset,
1221 (uint64_t)Section.Address + Section.StubOffset,
1223 Section.StubOffset += getMaxStubSize();
1225 if (SymType == SymbolRef::ST_Unknown) {
1226 // Restore the TOC for external calls
1227 if (AbiVariant == 2)
1228 writeInt32BE(Target + 4, 0xE8410018); // ld r2,28(r1)
1230 writeInt32BE(Target + 4, 0xE8410028); // ld r2,40(r1)
1233 } else if (RelType == ELF::R_PPC64_TOC16 ||
1234 RelType == ELF::R_PPC64_TOC16_DS ||
1235 RelType == ELF::R_PPC64_TOC16_LO ||
1236 RelType == ELF::R_PPC64_TOC16_LO_DS ||
1237 RelType == ELF::R_PPC64_TOC16_HI ||
1238 RelType == ELF::R_PPC64_TOC16_HA) {
1239 // These relocations are supposed to subtract the TOC address from
1240 // the final value. This does not fit cleanly into the RuntimeDyld
1241 // scheme, since there may be *two* sections involved in determining
1242 // the relocation value (the section of the symbol refered to by the
1243 // relocation, and the TOC section associated with the current module).
1245 // Fortunately, these relocations are currently only ever generated
1246 // refering to symbols that themselves reside in the TOC, which means
1247 // that the two sections are actually the same. Thus they cancel out
1248 // and we can immediately resolve the relocation right now.
1250 case ELF::R_PPC64_TOC16: RelType = ELF::R_PPC64_ADDR16; break;
1251 case ELF::R_PPC64_TOC16_DS: RelType = ELF::R_PPC64_ADDR16_DS; break;
1252 case ELF::R_PPC64_TOC16_LO: RelType = ELF::R_PPC64_ADDR16_LO; break;
1253 case ELF::R_PPC64_TOC16_LO_DS: RelType = ELF::R_PPC64_ADDR16_LO_DS; break;
1254 case ELF::R_PPC64_TOC16_HI: RelType = ELF::R_PPC64_ADDR16_HI; break;
1255 case ELF::R_PPC64_TOC16_HA: RelType = ELF::R_PPC64_ADDR16_HA; break;
1256 default: llvm_unreachable("Wrong relocation type.");
1259 RelocationValueRef TOCValue;
1260 findPPC64TOCSection(Obj, ObjSectionToID, TOCValue);
1261 if (Value.SymbolName || Value.SectionID != TOCValue.SectionID)
1262 llvm_unreachable("Unsupported TOC relocation.");
1263 Value.Addend -= TOCValue.Addend;
1264 resolveRelocation(Sections[SectionID], Offset, Value.Addend, RelType, 0);
1266 // There are two ways to refer to the TOC address directly: either
1267 // via a ELF::R_PPC64_TOC relocation (where both symbol and addend are
1268 // ignored), or via any relocation that refers to the magic ".TOC."
1269 // symbols (in which case the addend is respected).
1270 if (RelType == ELF::R_PPC64_TOC) {
1271 RelType = ELF::R_PPC64_ADDR64;
1272 findPPC64TOCSection(Obj, ObjSectionToID, Value);
1273 } else if (TargetName == ".TOC.") {
1274 findPPC64TOCSection(Obj, ObjSectionToID, Value);
1275 Value.Addend += Addend;
1278 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1280 if (Value.SymbolName)
1281 addRelocationForSymbol(RE, Value.SymbolName);
1283 addRelocationForSection(RE, Value.SectionID);
1285 } else if (Arch == Triple::systemz &&
1286 (RelType == ELF::R_390_PLT32DBL || RelType == ELF::R_390_GOTENT)) {
1287 // Create function stubs for both PLT and GOT references, regardless of
1288 // whether the GOT reference is to data or code. The stub contains the
1289 // full address of the symbol, as needed by GOT references, and the
1290 // executable part only adds an overhead of 8 bytes.
1292 // We could try to conserve space by allocating the code and data
1293 // parts of the stub separately. However, as things stand, we allocate
1294 // a stub for every relocation, so using a GOT in JIT code should be
1295 // no less space efficient than using an explicit constant pool.
1296 DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation.");
1297 SectionEntry &Section = Sections[SectionID];
1299 // Look for an existing stub.
1300 StubMap::const_iterator i = Stubs.find(Value);
1301 uintptr_t StubAddress;
1302 if (i != Stubs.end()) {
1303 StubAddress = uintptr_t(Section.Address) + i->second;
1304 DEBUG(dbgs() << " Stub function found\n");
1306 // Create a new stub function.
1307 DEBUG(dbgs() << " Create a new stub function\n");
1309 uintptr_t BaseAddress = uintptr_t(Section.Address);
1310 uintptr_t StubAlignment = getStubAlignment();
1311 StubAddress = (BaseAddress + Section.StubOffset + StubAlignment - 1) &
1313 unsigned StubOffset = StubAddress - BaseAddress;
1315 Stubs[Value] = StubOffset;
1316 createStubFunction((uint8_t *)StubAddress);
1317 RelocationEntry RE(SectionID, StubOffset + 8, ELF::R_390_64,
1319 if (Value.SymbolName)
1320 addRelocationForSymbol(RE, Value.SymbolName);
1322 addRelocationForSection(RE, Value.SectionID);
1323 Section.StubOffset = StubOffset + getMaxStubSize();
1326 if (RelType == ELF::R_390_GOTENT)
1327 resolveRelocation(Section, Offset, StubAddress + 8, ELF::R_390_PC32DBL,
1330 resolveRelocation(Section, Offset, StubAddress, RelType, Addend);
1331 } else if (Arch == Triple::x86_64 && RelType == ELF::R_X86_64_PLT32) {
1332 // The way the PLT relocations normally work is that the linker allocates
1334 // PLT and this relocation makes a PC-relative call into the PLT. The PLT
1335 // entry will then jump to an address provided by the GOT. On first call,
1337 // GOT address will point back into PLT code that resolves the symbol. After
1338 // the first call, the GOT entry points to the actual function.
1340 // For local functions we're ignoring all of that here and just replacing
1341 // the PLT32 relocation type with PC32, which will translate the relocation
1342 // into a PC-relative call directly to the function. For external symbols we
1343 // can't be sure the function will be within 2^32 bytes of the call site, so
1344 // we need to create a stub, which calls into the GOT. This case is
1345 // equivalent to the usual PLT implementation except that we use the stub
1346 // mechanism in RuntimeDyld (which puts stubs at the end of the section)
1347 // rather than allocating a PLT section.
1348 if (Value.SymbolName) {
1349 // This is a call to an external function.
1350 // Look for an existing stub.
1351 SectionEntry &Section = Sections[SectionID];
1352 StubMap::const_iterator i = Stubs.find(Value);
1353 uintptr_t StubAddress;
1354 if (i != Stubs.end()) {
1355 StubAddress = uintptr_t(Section.Address) + i->second;
1356 DEBUG(dbgs() << " Stub function found\n");
1358 // Create a new stub function (equivalent to a PLT entry).
1359 DEBUG(dbgs() << " Create a new stub function\n");
1361 uintptr_t BaseAddress = uintptr_t(Section.Address);
1362 uintptr_t StubAlignment = getStubAlignment();
1363 StubAddress = (BaseAddress + Section.StubOffset + StubAlignment - 1) &
1365 unsigned StubOffset = StubAddress - BaseAddress;
1366 Stubs[Value] = StubOffset;
1367 createStubFunction((uint8_t *)StubAddress);
1369 // Create a GOT entry for the external function.
1370 GOTEntries.push_back(Value);
1372 // Make our stub function a relative call to the GOT entry.
1373 RelocationEntry RE(SectionID, StubOffset + 2, ELF::R_X86_64_GOTPCREL,
1375 addRelocationForSymbol(RE, Value.SymbolName);
1377 // Bump our stub offset counter
1378 Section.StubOffset = StubOffset + getMaxStubSize();
1381 // Make the target call a call into the stub table.
1382 resolveRelocation(Section, Offset, StubAddress, ELF::R_X86_64_PC32,
1385 RelocationEntry RE(SectionID, Offset, ELF::R_X86_64_PC32, Value.Addend,
1387 addRelocationForSection(RE, Value.SectionID);
1390 if (Arch == Triple::x86_64 && RelType == ELF::R_X86_64_GOTPCREL) {
1391 GOTEntries.push_back(Value);
1393 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend, Value.Offset);
1394 if (Value.SymbolName)
1395 addRelocationForSymbol(RE, Value.SymbolName);
1397 addRelocationForSection(RE, Value.SectionID);
1402 void RuntimeDyldELF::updateGOTEntries(StringRef Name, uint64_t Addr) {
1404 SmallVectorImpl<std::pair<SID, GOTRelocations>>::iterator it;
1405 SmallVectorImpl<std::pair<SID, GOTRelocations>>::iterator end = GOTs.end();
1407 for (it = GOTs.begin(); it != end; ++it) {
1408 GOTRelocations &GOTEntries = it->second;
1409 for (int i = 0, e = GOTEntries.size(); i != e; ++i) {
1410 if (GOTEntries[i].SymbolName != nullptr &&
1411 GOTEntries[i].SymbolName == Name) {
1412 GOTEntries[i].Offset = Addr;
1418 size_t RuntimeDyldELF::getGOTEntrySize() {
1419 // We don't use the GOT in all of these cases, but it's essentially free
1420 // to put them all here.
1423 case Triple::x86_64:
1424 case Triple::aarch64:
1425 case Triple::aarch64_be:
1427 case Triple::ppc64le:
1428 case Triple::systemz:
1429 Result = sizeof(uint64_t);
1435 case Triple::mipsel:
1436 Result = sizeof(uint32_t);
1439 llvm_unreachable("Unsupported CPU type!");
1444 uint64_t RuntimeDyldELF::findGOTEntry(uint64_t LoadAddress, uint64_t Offset) {
1446 const size_t GOTEntrySize = getGOTEntrySize();
1448 SmallVectorImpl<std::pair<SID, GOTRelocations>>::const_iterator it;
1449 SmallVectorImpl<std::pair<SID, GOTRelocations>>::const_iterator end =
1453 for (it = GOTs.begin(); it != end; ++it) {
1454 SID GOTSectionID = it->first;
1455 const GOTRelocations &GOTEntries = it->second;
1457 // Find the matching entry in our vector.
1458 uint64_t SymbolOffset = 0;
1459 for (int i = 0, e = GOTEntries.size(); i != e; ++i) {
1460 if (!GOTEntries[i].SymbolName) {
1461 if (getSectionLoadAddress(GOTEntries[i].SectionID) == LoadAddress &&
1462 GOTEntries[i].Offset == Offset) {
1464 SymbolOffset = GOTEntries[i].Offset;
1468 // GOT entries for external symbols use the addend as the address when
1469 // the external symbol has been resolved.
1470 if (GOTEntries[i].Offset == LoadAddress) {
1472 // Don't use the Addend here. The relocation handler will use it.
1478 if (GOTIndex != -1) {
1479 if (GOTEntrySize == sizeof(uint64_t)) {
1480 uint64_t *LocalGOTAddr = (uint64_t *)getSectionAddress(GOTSectionID);
1481 // Fill in this entry with the address of the symbol being referenced.
1482 LocalGOTAddr[GOTIndex] = LoadAddress + SymbolOffset;
1484 uint32_t *LocalGOTAddr = (uint32_t *)getSectionAddress(GOTSectionID);
1485 // Fill in this entry with the address of the symbol being referenced.
1486 LocalGOTAddr[GOTIndex] = (uint32_t)(LoadAddress + SymbolOffset);
1489 // Calculate the load address of this entry
1490 return getSectionLoadAddress(GOTSectionID) + (GOTIndex * GOTEntrySize);
1494 assert(GOTIndex != -1 && "Unable to find requested GOT entry.");
1498 void RuntimeDyldELF::finalizeLoad(ObjectImage &ObjImg,
1499 ObjSectionToIDMap &SectionMap) {
1500 // If necessary, allocate the global offset table
1502 // Allocate the GOT if necessary
1503 size_t numGOTEntries = GOTEntries.size();
1504 if (numGOTEntries != 0) {
1505 // Allocate memory for the section
1506 unsigned SectionID = Sections.size();
1507 size_t TotalSize = numGOTEntries * getGOTEntrySize();
1508 uint8_t *Addr = MemMgr->allocateDataSection(TotalSize, getGOTEntrySize(),
1509 SectionID, ".got", false);
1511 report_fatal_error("Unable to allocate memory for GOT!");
1513 GOTs.push_back(std::make_pair(SectionID, GOTEntries));
1514 Sections.push_back(SectionEntry(".got", Addr, TotalSize, 0));
1515 // For now, initialize all GOT entries to zero. We'll fill them in as
1516 // needed when GOT-based relocations are applied.
1517 memset(Addr, 0, TotalSize);
1520 report_fatal_error("Unable to allocate memory for GOT!");
1523 // Look for and record the EH frame section.
1524 ObjSectionToIDMap::iterator i, e;
1525 for (i = SectionMap.begin(), e = SectionMap.end(); i != e; ++i) {
1526 const SectionRef &Section = i->first;
1528 Section.getName(Name);
1529 if (Name == ".eh_frame") {
1530 UnregisteredEHFrameSections.push_back(i->second);
1536 bool RuntimeDyldELF::isCompatibleFormat(const ObjectBuffer *Buffer) const {
1537 if (Buffer->getBufferSize() < strlen(ELF::ElfMagic))
1539 return (memcmp(Buffer->getBufferStart(), ELF::ElfMagic,
1540 strlen(ELF::ElfMagic))) == 0;
1543 bool RuntimeDyldELF::isCompatibleFile(const object::ObjectFile *Obj) const {
1544 return Obj->isELF();