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 "RuntimeDyldCheckerImpl.h"
16 #include "llvm/ADT/IntervalMap.h"
17 #include "llvm/ADT/STLExtras.h"
18 #include "llvm/ADT/StringRef.h"
19 #include "llvm/ADT/Triple.h"
20 #include "llvm/MC/MCStreamer.h"
21 #include "llvm/Object/ELFObjectFile.h"
22 #include "llvm/Object/ObjectFile.h"
23 #include "llvm/Support/ELF.h"
24 #include "llvm/Support/Endian.h"
25 #include "llvm/Support/MemoryBuffer.h"
26 #include "llvm/Support/TargetRegistry.h"
29 using namespace llvm::object;
31 #define DEBUG_TYPE "dyld"
33 static inline std::error_code check(std::error_code Err) {
35 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;
55 DyldELFObject(MemoryBufferRef Wrapper, std::error_code &ec);
57 void updateSectionAddress(const SectionRef &Sec, uint64_t Addr);
59 void updateSymbolAddress(const SymbolRef &SymRef, uint64_t Addr);
61 // Methods for type inquiry through isa, cast and dyn_cast
62 static inline bool classof(const Binary *v) {
63 return (isa<ELFObjectFile<ELFT>>(v) &&
64 classof(cast<ELFObjectFile<ELFT>>(v)));
66 static inline bool classof(const ELFObjectFile<ELFT> *v) {
67 return v->isDyldType();
74 // The MemoryBuffer passed into this constructor is just a wrapper around the
75 // actual memory. Ultimately, the Binary parent class will take ownership of
76 // this MemoryBuffer object but not the underlying memory.
78 DyldELFObject<ELFT>::DyldELFObject(MemoryBufferRef Wrapper, std::error_code &EC)
79 : ELFObjectFile<ELFT>(Wrapper, EC) {
80 this->isDyldELFObject = true;
84 void DyldELFObject<ELFT>::updateSectionAddress(const SectionRef &Sec,
86 DataRefImpl ShdrRef = Sec.getRawDataRefImpl();
88 const_cast<Elf_Shdr *>(reinterpret_cast<const Elf_Shdr *>(ShdrRef.p));
90 // This assumes the address passed in matches the target address bitness
91 // The template-based type cast handles everything else.
92 shdr->sh_addr = static_cast<addr_type>(Addr);
96 void DyldELFObject<ELFT>::updateSymbolAddress(const SymbolRef &SymRef,
99 Elf_Sym *sym = const_cast<Elf_Sym *>(
100 ELFObjectFile<ELFT>::getSymbol(SymRef.getRawDataRefImpl()));
102 // This assumes the address passed in matches the target address bitness
103 // The template-based type cast handles everything else.
104 sym->st_value = static_cast<addr_type>(Addr);
107 class LoadedELFObjectInfo
108 : public RuntimeDyld::LoadedObjectInfoHelper<LoadedELFObjectInfo> {
110 LoadedELFObjectInfo(RuntimeDyldImpl &RTDyld, unsigned BeginIdx,
112 : LoadedObjectInfoHelper(RTDyld, BeginIdx, EndIdx) {}
114 OwningBinary<ObjectFile>
115 getObjectForDebug(const ObjectFile &Obj) const override;
118 template <typename ELFT>
119 std::unique_ptr<DyldELFObject<ELFT>>
120 createRTDyldELFObject(MemoryBufferRef Buffer,
121 const LoadedELFObjectInfo &L,
122 std::error_code &ec) {
123 typedef typename ELFFile<ELFT>::Elf_Shdr Elf_Shdr;
124 typedef typename ELFDataTypeTypedefHelper<ELFT>::value_type addr_type;
126 std::unique_ptr<DyldELFObject<ELFT>> Obj =
127 llvm::make_unique<DyldELFObject<ELFT>>(Buffer, ec);
129 // Iterate over all sections in the object.
130 for (const auto &Sec : Obj->sections()) {
131 StringRef SectionName;
132 Sec.getName(SectionName);
133 if (SectionName != "") {
134 DataRefImpl ShdrRef = Sec.getRawDataRefImpl();
135 Elf_Shdr *shdr = const_cast<Elf_Shdr *>(
136 reinterpret_cast<const Elf_Shdr *>(ShdrRef.p));
138 if (uint64_t SecLoadAddr = L.getSectionLoadAddress(SectionName)) {
139 // This assumes that the address passed in matches the target address
140 // bitness. The template-based type cast handles everything else.
141 shdr->sh_addr = static_cast<addr_type>(SecLoadAddr);
149 OwningBinary<ObjectFile> createELFDebugObject(const ObjectFile &Obj,
150 const LoadedELFObjectInfo &L) {
151 assert(Obj.isELF() && "Not an ELF object file.");
153 std::unique_ptr<MemoryBuffer> Buffer =
154 MemoryBuffer::getMemBufferCopy(Obj.getData(), Obj.getFileName());
158 std::unique_ptr<ObjectFile> DebugObj;
159 if (Obj.getBytesInAddress() == 4 && Obj.isLittleEndian()) {
160 typedef ELFType<support::little, false> ELF32LE;
161 DebugObj = createRTDyldELFObject<ELF32LE>(Buffer->getMemBufferRef(), L, ec);
162 } else if (Obj.getBytesInAddress() == 4 && !Obj.isLittleEndian()) {
163 typedef ELFType<support::big, false> ELF32BE;
164 DebugObj = createRTDyldELFObject<ELF32BE>(Buffer->getMemBufferRef(), L, ec);
165 } else if (Obj.getBytesInAddress() == 8 && !Obj.isLittleEndian()) {
166 typedef ELFType<support::big, true> ELF64BE;
167 DebugObj = createRTDyldELFObject<ELF64BE>(Buffer->getMemBufferRef(), L, ec);
168 } else if (Obj.getBytesInAddress() == 8 && Obj.isLittleEndian()) {
169 typedef ELFType<support::little, true> ELF64LE;
170 DebugObj = createRTDyldELFObject<ELF64LE>(Buffer->getMemBufferRef(), L, ec);
172 llvm_unreachable("Unexpected ELF format");
174 assert(!ec && "Could not construct copy ELF object file");
176 return OwningBinary<ObjectFile>(std::move(DebugObj), std::move(Buffer));
179 OwningBinary<ObjectFile>
180 LoadedELFObjectInfo::getObjectForDebug(const ObjectFile &Obj) const {
181 return createELFDebugObject(Obj, *this);
188 RuntimeDyldELF::RuntimeDyldELF(RuntimeDyld::MemoryManager &MemMgr,
189 RuntimeDyld::SymbolResolver &Resolver)
190 : RuntimeDyldImpl(MemMgr, Resolver), GOTSectionID(0), CurrentGOTIndex(0) {}
191 RuntimeDyldELF::~RuntimeDyldELF() {}
193 void RuntimeDyldELF::registerEHFrames() {
194 for (int i = 0, e = UnregisteredEHFrameSections.size(); i != e; ++i) {
195 SID EHFrameSID = UnregisteredEHFrameSections[i];
196 uint8_t *EHFrameAddr = Sections[EHFrameSID].Address;
197 uint64_t EHFrameLoadAddr = Sections[EHFrameSID].LoadAddress;
198 size_t EHFrameSize = Sections[EHFrameSID].Size;
199 MemMgr.registerEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
200 RegisteredEHFrameSections.push_back(EHFrameSID);
202 UnregisteredEHFrameSections.clear();
205 void RuntimeDyldELF::deregisterEHFrames() {
206 for (int i = 0, e = RegisteredEHFrameSections.size(); i != e; ++i) {
207 SID EHFrameSID = RegisteredEHFrameSections[i];
208 uint8_t *EHFrameAddr = Sections[EHFrameSID].Address;
209 uint64_t EHFrameLoadAddr = Sections[EHFrameSID].LoadAddress;
210 size_t EHFrameSize = Sections[EHFrameSID].Size;
211 MemMgr.deregisterEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
213 RegisteredEHFrameSections.clear();
216 std::unique_ptr<RuntimeDyld::LoadedObjectInfo>
217 RuntimeDyldELF::loadObject(const object::ObjectFile &O) {
218 unsigned SectionStartIdx, SectionEndIdx;
219 std::tie(SectionStartIdx, SectionEndIdx) = loadObjectImpl(O);
220 return llvm::make_unique<LoadedELFObjectInfo>(*this, SectionStartIdx,
224 void RuntimeDyldELF::resolveX86_64Relocation(const SectionEntry &Section,
225 uint64_t Offset, uint64_t Value,
226 uint32_t Type, int64_t Addend,
227 uint64_t SymOffset) {
230 llvm_unreachable("Relocation type not implemented yet!");
232 case ELF::R_X86_64_64: {
233 support::ulittle64_t::ref(Section.Address + Offset) = Value + Addend;
234 DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend)) << " at "
235 << format("%p\n", Section.Address + Offset));
238 case ELF::R_X86_64_32:
239 case ELF::R_X86_64_32S: {
241 assert((Type == ELF::R_X86_64_32 && (Value <= UINT32_MAX)) ||
242 (Type == ELF::R_X86_64_32S &&
243 ((int64_t)Value <= INT32_MAX && (int64_t)Value >= INT32_MIN)));
244 uint32_t TruncatedAddr = (Value & 0xFFFFFFFF);
245 support::ulittle32_t::ref(Section.Address + Offset) = TruncatedAddr;
246 DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr) << " at "
247 << format("%p\n", Section.Address + Offset));
250 case ELF::R_X86_64_PC32: {
251 uint64_t FinalAddress = Section.LoadAddress + Offset;
252 int64_t RealOffset = Value + Addend - FinalAddress;
253 assert(isInt<32>(RealOffset));
254 int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
255 support::ulittle32_t::ref(Section.Address + Offset) = TruncOffset;
258 case ELF::R_X86_64_PC64: {
259 uint64_t FinalAddress = Section.LoadAddress + Offset;
260 int64_t RealOffset = Value + Addend - FinalAddress;
261 support::ulittle64_t::ref(Section.Address + Offset) = RealOffset;
267 void RuntimeDyldELF::resolveX86Relocation(const SectionEntry &Section,
268 uint64_t Offset, uint32_t Value,
269 uint32_t Type, int32_t Addend) {
271 case ELF::R_386_32: {
272 support::ulittle32_t::ref(Section.Address + Offset) = Value + Addend;
275 case ELF::R_386_PC32: {
276 uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
277 uint32_t RealOffset = Value + Addend - FinalAddress;
278 support::ulittle32_t::ref(Section.Address + Offset) = RealOffset;
282 // There are other relocation types, but it appears these are the
283 // only ones currently used by the LLVM ELF object writer
284 llvm_unreachable("Relocation type not implemented yet!");
289 void RuntimeDyldELF::resolveAArch64Relocation(const SectionEntry &Section,
290 uint64_t Offset, uint64_t Value,
291 uint32_t Type, int64_t Addend) {
292 uint32_t *TargetPtr = reinterpret_cast<uint32_t *>(Section.Address + Offset);
293 uint64_t FinalAddress = Section.LoadAddress + Offset;
295 DEBUG(dbgs() << "resolveAArch64Relocation, LocalAddress: 0x"
296 << format("%llx", Section.Address + Offset)
297 << " FinalAddress: 0x" << format("%llx", FinalAddress)
298 << " Value: 0x" << format("%llx", Value) << " Type: 0x"
299 << format("%x", Type) << " Addend: 0x" << format("%llx", Addend)
304 llvm_unreachable("Relocation type not implemented yet!");
306 case ELF::R_AARCH64_ABS64: {
307 uint64_t *TargetPtr =
308 reinterpret_cast<uint64_t *>(Section.Address + Offset);
309 *TargetPtr = Value + Addend;
312 case ELF::R_AARCH64_PREL32: {
313 uint64_t Result = Value + Addend - FinalAddress;
314 assert(static_cast<int64_t>(Result) >= INT32_MIN &&
315 static_cast<int64_t>(Result) <= UINT32_MAX);
316 *TargetPtr = static_cast<uint32_t>(Result & 0xffffffffU);
319 case ELF::R_AARCH64_CALL26: // fallthrough
320 case ELF::R_AARCH64_JUMP26: {
321 // Operation: S+A-P. Set Call or B immediate value to bits fff_fffc of the
323 uint64_t BranchImm = Value + Addend - FinalAddress;
325 // "Check that -2^27 <= result < 2^27".
326 assert(isInt<28>(BranchImm));
328 // AArch64 code is emitted with .rela relocations. The data already in any
329 // bits affected by the relocation on entry is garbage.
330 *TargetPtr &= 0xfc000000U;
331 // Immediate goes in bits 25:0 of B and BL.
332 *TargetPtr |= static_cast<uint32_t>(BranchImm & 0xffffffcU) >> 2;
335 case ELF::R_AARCH64_MOVW_UABS_G3: {
336 uint64_t Result = Value + Addend;
338 // AArch64 code is emitted with .rela relocations. The data already in any
339 // bits affected by the relocation on entry is garbage.
340 *TargetPtr &= 0xffe0001fU;
341 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
342 *TargetPtr |= Result >> (48 - 5);
343 // Shift must be "lsl #48", in bits 22:21
344 assert((*TargetPtr >> 21 & 0x3) == 3 && "invalid shift for relocation");
347 case ELF::R_AARCH64_MOVW_UABS_G2_NC: {
348 uint64_t Result = Value + Addend;
350 // AArch64 code is emitted with .rela relocations. The data already in any
351 // bits affected by the relocation on entry is garbage.
352 *TargetPtr &= 0xffe0001fU;
353 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
354 *TargetPtr |= ((Result & 0xffff00000000ULL) >> (32 - 5));
355 // Shift must be "lsl #32", in bits 22:21
356 assert((*TargetPtr >> 21 & 0x3) == 2 && "invalid shift for relocation");
359 case ELF::R_AARCH64_MOVW_UABS_G1_NC: {
360 uint64_t Result = Value + Addend;
362 // AArch64 code is emitted with .rela relocations. The data already in any
363 // bits affected by the relocation on entry is garbage.
364 *TargetPtr &= 0xffe0001fU;
365 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
366 *TargetPtr |= ((Result & 0xffff0000U) >> (16 - 5));
367 // Shift must be "lsl #16", in bits 22:2
368 assert((*TargetPtr >> 21 & 0x3) == 1 && "invalid shift for relocation");
371 case ELF::R_AARCH64_MOVW_UABS_G0_NC: {
372 uint64_t Result = Value + Addend;
374 // AArch64 code is emitted with .rela relocations. The data already in any
375 // bits affected by the relocation on entry is garbage.
376 *TargetPtr &= 0xffe0001fU;
377 // Immediate goes in bits 20:5 of MOVZ/MOVK instruction
378 *TargetPtr |= ((Result & 0xffffU) << 5);
379 // Shift must be "lsl #0", in bits 22:21.
380 assert((*TargetPtr >> 21 & 0x3) == 0 && "invalid shift for relocation");
383 case ELF::R_AARCH64_ADR_PREL_PG_HI21: {
384 // Operation: Page(S+A) - Page(P)
386 ((Value + Addend) & ~0xfffULL) - (FinalAddress & ~0xfffULL);
388 // Check that -2^32 <= X < 2^32
389 assert(isInt<33>(Result) && "overflow check failed for relocation");
391 // AArch64 code is emitted with .rela relocations. The data already in any
392 // bits affected by the relocation on entry is garbage.
393 *TargetPtr &= 0x9f00001fU;
394 // Immediate goes in bits 30:29 + 5:23 of ADRP instruction, taken
395 // from bits 32:12 of X.
396 *TargetPtr |= ((Result & 0x3000U) << (29 - 12));
397 *TargetPtr |= ((Result & 0x1ffffc000ULL) >> (14 - 5));
400 case ELF::R_AARCH64_LDST32_ABS_LO12_NC: {
402 uint64_t Result = Value + Addend;
404 // AArch64 code is emitted with .rela relocations. The data already in any
405 // bits affected by the relocation on entry is garbage.
406 *TargetPtr &= 0xffc003ffU;
407 // Immediate goes in bits 21:10 of LD/ST instruction, taken
408 // from bits 11:2 of X
409 *TargetPtr |= ((Result & 0xffc) << (10 - 2));
412 case ELF::R_AARCH64_LDST64_ABS_LO12_NC: {
414 uint64_t Result = Value + Addend;
416 // AArch64 code is emitted with .rela relocations. The data already in any
417 // bits affected by the relocation on entry is garbage.
418 *TargetPtr &= 0xffc003ffU;
419 // Immediate goes in bits 21:10 of LD/ST instruction, taken
420 // from bits 11:3 of X
421 *TargetPtr |= ((Result & 0xff8) << (10 - 3));
427 void RuntimeDyldELF::resolveARMRelocation(const SectionEntry &Section,
428 uint64_t Offset, uint32_t Value,
429 uint32_t Type, int32_t Addend) {
430 // TODO: Add Thumb relocations.
431 uint32_t *TargetPtr = (uint32_t *)(Section.Address + Offset);
432 uint32_t FinalAddress = ((Section.LoadAddress + Offset) & 0xFFFFFFFF);
435 DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: "
436 << Section.Address + Offset
437 << " FinalAddress: " << format("%p", FinalAddress) << " Value: "
438 << format("%x", Value) << " Type: " << format("%x", Type)
439 << " Addend: " << format("%x", Addend) << "\n");
443 llvm_unreachable("Not implemented relocation type!");
445 case ELF::R_ARM_NONE:
447 case ELF::R_ARM_PREL31:
448 case ELF::R_ARM_TARGET1:
449 case ELF::R_ARM_ABS32:
452 // Write first 16 bit of 32 bit value to the mov instruction.
453 // Last 4 bit should be shifted.
454 case ELF::R_ARM_MOVW_ABS_NC:
455 case ELF::R_ARM_MOVT_ABS:
456 if (Type == ELF::R_ARM_MOVW_ABS_NC)
457 Value = Value & 0xFFFF;
458 else if (Type == ELF::R_ARM_MOVT_ABS)
459 Value = (Value >> 16) & 0xFFFF;
460 *TargetPtr &= ~0x000F0FFF;
461 *TargetPtr |= Value & 0xFFF;
462 *TargetPtr |= ((Value >> 12) & 0xF) << 16;
464 // Write 24 bit relative value to the branch instruction.
465 case ELF::R_ARM_PC24: // Fall through.
466 case ELF::R_ARM_CALL: // Fall through.
467 case ELF::R_ARM_JUMP24:
468 int32_t RelValue = static_cast<int32_t>(Value - FinalAddress - 8);
469 RelValue = (RelValue & 0x03FFFFFC) >> 2;
470 assert((*TargetPtr & 0xFFFFFF) == 0xFFFFFE);
471 *TargetPtr &= 0xFF000000;
472 *TargetPtr |= RelValue;
477 void RuntimeDyldELF::resolveMIPSRelocation(const SectionEntry &Section,
478 uint64_t Offset, uint32_t Value,
479 uint32_t Type, int32_t Addend) {
480 uint32_t *TargetPtr = (uint32_t *)(Section.Address + Offset);
483 DEBUG(dbgs() << "resolveMipselocation, LocalAddress: "
484 << Section.Address + Offset << " FinalAddress: "
485 << format("%p", Section.LoadAddress + Offset) << " Value: "
486 << format("%x", Value) << " Type: " << format("%x", Type)
487 << " Addend: " << format("%x", Addend) << "\n");
491 llvm_unreachable("Not implemented relocation type!");
497 *TargetPtr = ((*TargetPtr) & 0xfc000000) | ((Value & 0x0fffffff) >> 2);
499 case ELF::R_MIPS_HI16:
500 // Get the higher 16-bits. Also add 1 if bit 15 is 1.
502 ((*TargetPtr) & 0xffff0000) | (((Value + 0x8000) >> 16) & 0xffff);
504 case ELF::R_MIPS_LO16:
505 *TargetPtr = ((*TargetPtr) & 0xffff0000) | (Value & 0xffff);
510 void RuntimeDyldELF::setMipsABI(const ObjectFile &Obj) {
511 if (!StringRef(Triple::getArchTypePrefix(Arch)).equals("mips")) {
512 IsMipsO32ABI = false;
513 IsMipsN64ABI = false;
517 Obj.getPlatformFlags(AbiVariant);
518 IsMipsO32ABI = AbiVariant & ELF::EF_MIPS_ABI_O32;
519 IsMipsN64ABI = Obj.getFileFormatName().equals("ELF64-mips");
520 if (AbiVariant & ELF::EF_MIPS_ABI2)
521 llvm_unreachable("Mips N32 ABI is not supported yet");
524 void RuntimeDyldELF::resolveMIPS64Relocation(const SectionEntry &Section,
525 uint64_t Offset, uint64_t Value,
526 uint32_t Type, int64_t Addend,
529 uint32_t r_type = Type & 0xff;
530 uint32_t r_type2 = (Type >> 8) & 0xff;
531 uint32_t r_type3 = (Type >> 16) & 0xff;
533 // RelType is used to keep information for which relocation type we are
534 // applying relocation.
535 uint32_t RelType = r_type;
536 int64_t CalculatedValue = evaluateMIPS64Relocation(Section, Offset, Value,
538 SymOffset, SectionID);
539 if (r_type2 != ELF::R_MIPS_NONE) {
541 CalculatedValue = evaluateMIPS64Relocation(Section, Offset, 0, RelType,
542 CalculatedValue, SymOffset,
545 if (r_type3 != ELF::R_MIPS_NONE) {
547 CalculatedValue = evaluateMIPS64Relocation(Section, Offset, 0, RelType,
548 CalculatedValue, SymOffset,
551 applyMIPS64Relocation(Section.Address + Offset, CalculatedValue, RelType);
555 RuntimeDyldELF::evaluateMIPS64Relocation(const SectionEntry &Section,
556 uint64_t Offset, uint64_t Value,
557 uint32_t Type, int64_t Addend,
558 uint64_t SymOffset, SID SectionID) {
560 DEBUG(dbgs() << "evaluateMIPS64Relocation, LocalAddress: 0x"
561 << format("%llx", Section.Address + Offset)
562 << " FinalAddress: 0x"
563 << format("%llx", Section.LoadAddress + Offset)
564 << " Value: 0x" << format("%llx", Value) << " Type: 0x"
565 << format("%x", Type) << " Addend: 0x" << format("%llx", Addend)
566 << " SymOffset: " << format("%x", SymOffset)
571 llvm_unreachable("Not implemented relocation type!");
573 case ELF::R_MIPS_JALR:
574 case ELF::R_MIPS_NONE:
578 return Value + Addend;
580 return ((Value + Addend) >> 2) & 0x3ffffff;
581 case ELF::R_MIPS_GPREL16: {
582 uint64_t GOTAddr = getSectionLoadAddress(SectionToGOTMap[SectionID]);
583 return Value + Addend - (GOTAddr + 0x7ff0);
585 case ELF::R_MIPS_SUB:
586 return Value - Addend;
587 case ELF::R_MIPS_HI16:
588 // Get the higher 16-bits. Also add 1 if bit 15 is 1.
589 return ((Value + Addend + 0x8000) >> 16) & 0xffff;
590 case ELF::R_MIPS_LO16:
591 return (Value + Addend) & 0xffff;
592 case ELF::R_MIPS_CALL16:
593 case ELF::R_MIPS_GOT_DISP:
594 case ELF::R_MIPS_GOT_PAGE: {
595 uint8_t *LocalGOTAddr =
596 getSectionAddress(SectionToGOTMap[SectionID]) + SymOffset;
597 uint64_t GOTEntry = readBytesUnaligned(LocalGOTAddr, 8);
600 if (Type == ELF::R_MIPS_GOT_PAGE)
601 Value = (Value + 0x8000) & ~0xffff;
604 assert(GOTEntry == Value &&
605 "GOT entry has two different addresses.");
607 writeBytesUnaligned(Value, LocalGOTAddr, 8);
609 return (SymOffset - 0x7ff0) & 0xffff;
611 case ELF::R_MIPS_GOT_OFST: {
612 int64_t page = (Value + Addend + 0x8000) & ~0xffff;
613 return (Value + Addend - page) & 0xffff;
615 case ELF::R_MIPS_GPREL32: {
616 uint64_t GOTAddr = getSectionLoadAddress(SectionToGOTMap[SectionID]);
617 return Value + Addend - (GOTAddr + 0x7ff0);
619 case ELF::R_MIPS_PC16: {
620 uint64_t FinalAddress = (Section.LoadAddress + Offset);
621 return ((Value + Addend - FinalAddress - 4) >> 2) & 0xffff;
623 case ELF::R_MIPS_PC18_S3: {
624 uint64_t FinalAddress = (Section.LoadAddress + Offset);
625 return ((Value + Addend - ((FinalAddress | 7) ^ 7)) >> 3) & 0x3ffff;
627 case ELF::R_MIPS_PC19_S2: {
628 uint64_t FinalAddress = (Section.LoadAddress + Offset);
629 return ((Value + Addend - FinalAddress) >> 2) & 0x7ffff;
631 case ELF::R_MIPS_PC21_S2: {
632 uint64_t FinalAddress = (Section.LoadAddress + Offset);
633 return ((Value + Addend - FinalAddress) >> 2) & 0x1fffff;
635 case ELF::R_MIPS_PC26_S2: {
636 uint64_t FinalAddress = (Section.LoadAddress + Offset);
637 return ((Value + Addend - FinalAddress) >> 2) & 0x3ffffff;
639 case ELF::R_MIPS_PCHI16: {
640 uint64_t FinalAddress = (Section.LoadAddress + Offset);
641 return ((Value + Addend - FinalAddress + 0x8000) >> 16) & 0xffff;
643 case ELF::R_MIPS_PCLO16: {
644 uint64_t FinalAddress = (Section.LoadAddress + Offset);
645 return (Value + Addend - FinalAddress) & 0xffff;
651 void RuntimeDyldELF::applyMIPS64Relocation(uint8_t *TargetPtr,
652 int64_t CalculatedValue,
654 uint32_t Insn = readBytesUnaligned(TargetPtr, 4);
660 case ELF::R_MIPS_GPREL32:
661 writeBytesUnaligned(CalculatedValue & 0xffffffff, TargetPtr, 4);
664 case ELF::R_MIPS_SUB:
665 writeBytesUnaligned(CalculatedValue, TargetPtr, 8);
668 case ELF::R_MIPS_PC26_S2:
669 Insn = (Insn & 0xfc000000) | CalculatedValue;
670 writeBytesUnaligned(Insn, TargetPtr, 4);
672 case ELF::R_MIPS_GPREL16:
673 Insn = (Insn & 0xffff0000) | (CalculatedValue & 0xffff);
674 writeBytesUnaligned(Insn, TargetPtr, 4);
676 case ELF::R_MIPS_HI16:
677 case ELF::R_MIPS_LO16:
678 case ELF::R_MIPS_PCHI16:
679 case ELF::R_MIPS_PCLO16:
680 case ELF::R_MIPS_PC16:
681 case ELF::R_MIPS_CALL16:
682 case ELF::R_MIPS_GOT_DISP:
683 case ELF::R_MIPS_GOT_PAGE:
684 case ELF::R_MIPS_GOT_OFST:
685 Insn = (Insn & 0xffff0000) | CalculatedValue;
686 writeBytesUnaligned(Insn, TargetPtr, 4);
688 case ELF::R_MIPS_PC18_S3:
689 Insn = (Insn & 0xfffc0000) | CalculatedValue;
690 writeBytesUnaligned(Insn, TargetPtr, 4);
692 case ELF::R_MIPS_PC19_S2:
693 Insn = (Insn & 0xfff80000) | CalculatedValue;
694 writeBytesUnaligned(Insn, TargetPtr, 4);
696 case ELF::R_MIPS_PC21_S2:
697 Insn = (Insn & 0xffe00000) | CalculatedValue;
698 writeBytesUnaligned(Insn, TargetPtr, 4);
703 // Return the .TOC. section and offset.
704 void RuntimeDyldELF::findPPC64TOCSection(const ObjectFile &Obj,
705 ObjSectionToIDMap &LocalSections,
706 RelocationValueRef &Rel) {
707 // Set a default SectionID in case we do not find a TOC section below.
708 // This may happen for references to TOC base base (sym@toc, .odp
709 // relocation) without a .toc directive. In this case just use the
710 // first section (which is usually the .odp) since the code won't
711 // reference the .toc base directly.
712 Rel.SymbolName = NULL;
715 // The TOC consists of sections .got, .toc, .tocbss, .plt in that
716 // order. The TOC starts where the first of these sections starts.
717 for (auto &Section: Obj.sections()) {
718 StringRef SectionName;
719 check(Section.getName(SectionName));
721 if (SectionName == ".got"
722 || SectionName == ".toc"
723 || SectionName == ".tocbss"
724 || SectionName == ".plt") {
725 Rel.SectionID = findOrEmitSection(Obj, Section, false, LocalSections);
730 // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000
731 // thus permitting a full 64 Kbytes segment.
735 // Returns the sections and offset associated with the ODP entry referenced
737 void RuntimeDyldELF::findOPDEntrySection(const ObjectFile &Obj,
738 ObjSectionToIDMap &LocalSections,
739 RelocationValueRef &Rel) {
740 // Get the ELF symbol value (st_value) to compare with Relocation offset in
742 for (section_iterator si = Obj.section_begin(), se = Obj.section_end();
744 section_iterator RelSecI = si->getRelocatedSection();
745 if (RelSecI == Obj.section_end())
748 StringRef RelSectionName;
749 check(RelSecI->getName(RelSectionName));
750 if (RelSectionName != ".opd")
753 for (relocation_iterator i = si->relocation_begin(),
754 e = si->relocation_end();
756 // The R_PPC64_ADDR64 relocation indicates the first field
759 check(i->getType(TypeFunc));
760 if (TypeFunc != ELF::R_PPC64_ADDR64) {
765 uint64_t TargetSymbolOffset;
766 symbol_iterator TargetSymbol = i->getSymbol();
767 check(i->getOffset(TargetSymbolOffset));
769 check(getELFRelocationAddend(*i, Addend));
775 // Just check if following relocation is a R_PPC64_TOC
777 check(i->getType(TypeTOC));
778 if (TypeTOC != ELF::R_PPC64_TOC)
781 // Finally compares the Symbol value and the target symbol offset
782 // to check if this .opd entry refers to the symbol the relocation
784 if (Rel.Addend != (int64_t)TargetSymbolOffset)
787 section_iterator tsi(Obj.section_end());
788 check(TargetSymbol->getSection(tsi));
789 bool IsCode = tsi->isText();
790 Rel.SectionID = findOrEmitSection(Obj, (*tsi), IsCode, LocalSections);
791 Rel.Addend = (intptr_t)Addend;
795 llvm_unreachable("Attempting to get address of ODP entry!");
798 // Relocation masks following the #lo(value), #hi(value), #ha(value),
799 // #higher(value), #highera(value), #highest(value), and #highesta(value)
800 // macros defined in section 4.5.1. Relocation Types of the PPC-elf64abi
803 static inline uint16_t applyPPClo(uint64_t value) { return value & 0xffff; }
805 static inline uint16_t applyPPChi(uint64_t value) {
806 return (value >> 16) & 0xffff;
809 static inline uint16_t applyPPCha (uint64_t value) {
810 return ((value + 0x8000) >> 16) & 0xffff;
813 static inline uint16_t applyPPChigher(uint64_t value) {
814 return (value >> 32) & 0xffff;
817 static inline uint16_t applyPPChighera (uint64_t value) {
818 return ((value + 0x8000) >> 32) & 0xffff;
821 static inline uint16_t applyPPChighest(uint64_t value) {
822 return (value >> 48) & 0xffff;
825 static inline uint16_t applyPPChighesta (uint64_t value) {
826 return ((value + 0x8000) >> 48) & 0xffff;
829 void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section,
830 uint64_t Offset, uint64_t Value,
831 uint32_t Type, int64_t Addend) {
832 uint8_t *LocalAddress = Section.Address + Offset;
835 llvm_unreachable("Relocation type not implemented yet!");
837 case ELF::R_PPC64_ADDR16:
838 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
840 case ELF::R_PPC64_ADDR16_DS:
841 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
843 case ELF::R_PPC64_ADDR16_LO:
844 writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
846 case ELF::R_PPC64_ADDR16_LO_DS:
847 writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
849 case ELF::R_PPC64_ADDR16_HI:
850 writeInt16BE(LocalAddress, applyPPChi(Value + Addend));
852 case ELF::R_PPC64_ADDR16_HA:
853 writeInt16BE(LocalAddress, applyPPCha(Value + Addend));
855 case ELF::R_PPC64_ADDR16_HIGHER:
856 writeInt16BE(LocalAddress, applyPPChigher(Value + Addend));
858 case ELF::R_PPC64_ADDR16_HIGHERA:
859 writeInt16BE(LocalAddress, applyPPChighera(Value + Addend));
861 case ELF::R_PPC64_ADDR16_HIGHEST:
862 writeInt16BE(LocalAddress, applyPPChighest(Value + Addend));
864 case ELF::R_PPC64_ADDR16_HIGHESTA:
865 writeInt16BE(LocalAddress, applyPPChighesta(Value + Addend));
867 case ELF::R_PPC64_ADDR14: {
868 assert(((Value + Addend) & 3) == 0);
869 // Preserve the AA/LK bits in the branch instruction
870 uint8_t aalk = *(LocalAddress + 3);
871 writeInt16BE(LocalAddress + 2, (aalk & 3) | ((Value + Addend) & 0xfffc));
873 case ELF::R_PPC64_REL16_LO: {
874 uint64_t FinalAddress = (Section.LoadAddress + Offset);
875 uint64_t Delta = Value - FinalAddress + Addend;
876 writeInt16BE(LocalAddress, applyPPClo(Delta));
878 case ELF::R_PPC64_REL16_HI: {
879 uint64_t FinalAddress = (Section.LoadAddress + Offset);
880 uint64_t Delta = Value - FinalAddress + Addend;
881 writeInt16BE(LocalAddress, applyPPChi(Delta));
883 case ELF::R_PPC64_REL16_HA: {
884 uint64_t FinalAddress = (Section.LoadAddress + Offset);
885 uint64_t Delta = Value - FinalAddress + Addend;
886 writeInt16BE(LocalAddress, applyPPCha(Delta));
888 case ELF::R_PPC64_ADDR32: {
889 int32_t Result = static_cast<int32_t>(Value + Addend);
890 if (SignExtend32<32>(Result) != Result)
891 llvm_unreachable("Relocation R_PPC64_ADDR32 overflow");
892 writeInt32BE(LocalAddress, Result);
894 case ELF::R_PPC64_REL24: {
895 uint64_t FinalAddress = (Section.LoadAddress + Offset);
896 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
897 if (SignExtend32<24>(delta) != delta)
898 llvm_unreachable("Relocation R_PPC64_REL24 overflow");
899 // Generates a 'bl <address>' instruction
900 writeInt32BE(LocalAddress, 0x48000001 | (delta & 0x03FFFFFC));
902 case ELF::R_PPC64_REL32: {
903 uint64_t FinalAddress = (Section.LoadAddress + Offset);
904 int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
905 if (SignExtend32<32>(delta) != delta)
906 llvm_unreachable("Relocation R_PPC64_REL32 overflow");
907 writeInt32BE(LocalAddress, delta);
909 case ELF::R_PPC64_REL64: {
910 uint64_t FinalAddress = (Section.LoadAddress + Offset);
911 uint64_t Delta = Value - FinalAddress + Addend;
912 writeInt64BE(LocalAddress, Delta);
914 case ELF::R_PPC64_ADDR64:
915 writeInt64BE(LocalAddress, Value + Addend);
920 void RuntimeDyldELF::resolveSystemZRelocation(const SectionEntry &Section,
921 uint64_t Offset, uint64_t Value,
922 uint32_t Type, int64_t Addend) {
923 uint8_t *LocalAddress = Section.Address + Offset;
926 llvm_unreachable("Relocation type not implemented yet!");
928 case ELF::R_390_PC16DBL:
929 case ELF::R_390_PLT16DBL: {
930 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
931 assert(int16_t(Delta / 2) * 2 == Delta && "R_390_PC16DBL overflow");
932 writeInt16BE(LocalAddress, Delta / 2);
935 case ELF::R_390_PC32DBL:
936 case ELF::R_390_PLT32DBL: {
937 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
938 assert(int32_t(Delta / 2) * 2 == Delta && "R_390_PC32DBL overflow");
939 writeInt32BE(LocalAddress, Delta / 2);
942 case ELF::R_390_PC32: {
943 int64_t Delta = (Value + Addend) - (Section.LoadAddress + Offset);
944 assert(int32_t(Delta) == Delta && "R_390_PC32 overflow");
945 writeInt32BE(LocalAddress, Delta);
949 writeInt64BE(LocalAddress, Value + Addend);
954 // The target location for the relocation is described by RE.SectionID and
955 // RE.Offset. RE.SectionID can be used to find the SectionEntry. Each
956 // SectionEntry has three members describing its location.
957 // SectionEntry::Address is the address at which the section has been loaded
958 // into memory in the current (host) process. SectionEntry::LoadAddress is the
959 // address that the section will have in the target process.
960 // SectionEntry::ObjAddress is the address of the bits for this section in the
961 // original emitted object image (also in the current address space).
963 // Relocations will be applied as if the section were loaded at
964 // SectionEntry::LoadAddress, but they will be applied at an address based
965 // on SectionEntry::Address. SectionEntry::ObjAddress will be used to refer to
966 // Target memory contents if they are required for value calculations.
968 // The Value parameter here is the load address of the symbol for the
969 // relocation to be applied. For relocations which refer to symbols in the
970 // current object Value will be the LoadAddress of the section in which
971 // the symbol resides (RE.Addend provides additional information about the
972 // symbol location). For external symbols, Value will be the address of the
973 // symbol in the target address space.
974 void RuntimeDyldELF::resolveRelocation(const RelocationEntry &RE,
976 const SectionEntry &Section = Sections[RE.SectionID];
977 return resolveRelocation(Section, RE.Offset, Value, RE.RelType, RE.Addend,
978 RE.SymOffset, RE.SectionID);
981 void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section,
982 uint64_t Offset, uint64_t Value,
983 uint32_t Type, int64_t Addend,
984 uint64_t SymOffset, SID SectionID) {
987 resolveX86_64Relocation(Section, Offset, Value, Type, Addend, SymOffset);
990 resolveX86Relocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
991 (uint32_t)(Addend & 0xffffffffL));
993 case Triple::aarch64:
994 case Triple::aarch64_be:
995 resolveAArch64Relocation(Section, Offset, Value, Type, Addend);
997 case Triple::arm: // Fall through.
1000 case Triple::thumbeb:
1001 resolveARMRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
1002 (uint32_t)(Addend & 0xffffffffL));
1004 case Triple::mips: // Fall through.
1005 case Triple::mipsel:
1006 case Triple::mips64:
1007 case Triple::mips64el:
1009 resolveMIPSRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL),
1010 Type, (uint32_t)(Addend & 0xffffffffL));
1011 else if (IsMipsN64ABI)
1012 resolveMIPS64Relocation(Section, Offset, Value, Type, Addend, SymOffset,
1015 llvm_unreachable("Mips ABI not handled");
1017 case Triple::ppc64: // Fall through.
1018 case Triple::ppc64le:
1019 resolvePPC64Relocation(Section, Offset, Value, Type, Addend);
1021 case Triple::systemz:
1022 resolveSystemZRelocation(Section, Offset, Value, Type, Addend);
1025 llvm_unreachable("Unsupported CPU type!");
1029 void *RuntimeDyldELF::computePlaceholderAddress(unsigned SectionID, uint64_t Offset) const {
1030 return (void*)(Sections[SectionID].ObjAddress + Offset);
1033 void RuntimeDyldELF::processSimpleRelocation(unsigned SectionID, uint64_t Offset, unsigned RelType, RelocationValueRef Value) {
1034 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend, Value.Offset);
1035 if (Value.SymbolName)
1036 addRelocationForSymbol(RE, Value.SymbolName);
1038 addRelocationForSection(RE, Value.SectionID);
1041 relocation_iterator RuntimeDyldELF::processRelocationRef(
1042 unsigned SectionID, relocation_iterator RelI,
1043 const ObjectFile &Obj,
1044 ObjSectionToIDMap &ObjSectionToID,
1047 Check(RelI->getType(RelType));
1049 Check(getELFRelocationAddend(*RelI, Addend));
1050 symbol_iterator Symbol = RelI->getSymbol();
1052 // Obtain the symbol name which is referenced in the relocation
1053 StringRef TargetName;
1054 if (Symbol != Obj.symbol_end())
1055 Symbol->getName(TargetName);
1056 DEBUG(dbgs() << "\t\tRelType: " << RelType << " Addend: " << Addend
1057 << " TargetName: " << TargetName << "\n");
1058 RelocationValueRef Value;
1059 // First search for the symbol in the local symbol table
1060 SymbolRef::Type SymType = SymbolRef::ST_Unknown;
1062 // Search for the symbol in the global symbol table
1063 RTDyldSymbolTable::const_iterator gsi = GlobalSymbolTable.end();
1064 if (Symbol != Obj.symbol_end()) {
1065 gsi = GlobalSymbolTable.find(TargetName.data());
1066 Symbol->getType(SymType);
1068 if (gsi != GlobalSymbolTable.end()) {
1069 const auto &SymInfo = gsi->second;
1070 Value.SectionID = SymInfo.getSectionID();
1071 Value.Offset = SymInfo.getOffset();
1072 Value.Addend = SymInfo.getOffset() + Addend;
1075 case SymbolRef::ST_Debug: {
1076 // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously
1077 // and can be changed by another developers. Maybe best way is add
1078 // a new symbol type ST_Section to SymbolRef and use it.
1079 section_iterator si(Obj.section_end());
1080 Symbol->getSection(si);
1081 if (si == Obj.section_end())
1082 llvm_unreachable("Symbol section not found, bad object file format!");
1083 DEBUG(dbgs() << "\t\tThis is section symbol\n");
1084 bool isCode = si->isText();
1085 Value.SectionID = findOrEmitSection(Obj, (*si), isCode, ObjSectionToID);
1086 Value.Addend = Addend;
1089 case SymbolRef::ST_Data:
1090 case SymbolRef::ST_Unknown: {
1091 Value.SymbolName = TargetName.data();
1092 Value.Addend = Addend;
1094 // Absolute relocations will have a zero symbol ID (STN_UNDEF), which
1095 // will manifest here as a NULL symbol name.
1096 // We can set this as a valid (but empty) symbol name, and rely
1097 // on addRelocationForSymbol to handle this.
1098 if (!Value.SymbolName)
1099 Value.SymbolName = "";
1103 llvm_unreachable("Unresolved symbol type!");
1109 Check(RelI->getOffset(Offset));
1111 DEBUG(dbgs() << "\t\tSectionID: " << SectionID << " Offset: " << Offset
1113 if ((Arch == Triple::aarch64 || Arch == Triple::aarch64_be) &&
1114 (RelType == ELF::R_AARCH64_CALL26 || RelType == ELF::R_AARCH64_JUMP26)) {
1115 // This is an AArch64 branch relocation, need to use a stub function.
1116 DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation.");
1117 SectionEntry &Section = Sections[SectionID];
1119 // Look for an existing stub.
1120 StubMap::const_iterator i = Stubs.find(Value);
1121 if (i != Stubs.end()) {
1122 resolveRelocation(Section, Offset, (uint64_t)Section.Address + i->second,
1124 DEBUG(dbgs() << " Stub function found\n");
1126 // Create a new stub function.
1127 DEBUG(dbgs() << " Create a new stub function\n");
1128 Stubs[Value] = Section.StubOffset;
1129 uint8_t *StubTargetAddr =
1130 createStubFunction(Section.Address + Section.StubOffset);
1132 RelocationEntry REmovz_g3(SectionID, StubTargetAddr - Section.Address,
1133 ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend);
1134 RelocationEntry REmovk_g2(SectionID, StubTargetAddr - Section.Address + 4,
1135 ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend);
1136 RelocationEntry REmovk_g1(SectionID, StubTargetAddr - Section.Address + 8,
1137 ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend);
1138 RelocationEntry REmovk_g0(SectionID,
1139 StubTargetAddr - Section.Address + 12,
1140 ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend);
1142 if (Value.SymbolName) {
1143 addRelocationForSymbol(REmovz_g3, Value.SymbolName);
1144 addRelocationForSymbol(REmovk_g2, Value.SymbolName);
1145 addRelocationForSymbol(REmovk_g1, Value.SymbolName);
1146 addRelocationForSymbol(REmovk_g0, Value.SymbolName);
1148 addRelocationForSection(REmovz_g3, Value.SectionID);
1149 addRelocationForSection(REmovk_g2, Value.SectionID);
1150 addRelocationForSection(REmovk_g1, Value.SectionID);
1151 addRelocationForSection(REmovk_g0, Value.SectionID);
1153 resolveRelocation(Section, Offset,
1154 (uint64_t)Section.Address + Section.StubOffset, RelType,
1156 Section.StubOffset += getMaxStubSize();
1158 } else if (Arch == Triple::arm) {
1159 if (RelType == ELF::R_ARM_PC24 || RelType == ELF::R_ARM_CALL ||
1160 RelType == ELF::R_ARM_JUMP24) {
1161 // This is an ARM branch relocation, need to use a stub function.
1162 DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.");
1163 SectionEntry &Section = Sections[SectionID];
1165 // Look for an existing stub.
1166 StubMap::const_iterator i = Stubs.find(Value);
1167 if (i != Stubs.end()) {
1168 resolveRelocation(Section, Offset, (uint64_t)Section.Address + i->second,
1170 DEBUG(dbgs() << " Stub function found\n");
1172 // Create a new stub function.
1173 DEBUG(dbgs() << " Create a new stub function\n");
1174 Stubs[Value] = Section.StubOffset;
1175 uint8_t *StubTargetAddr =
1176 createStubFunction(Section.Address + Section.StubOffset);
1177 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1178 ELF::R_ARM_ABS32, Value.Addend);
1179 if (Value.SymbolName)
1180 addRelocationForSymbol(RE, Value.SymbolName);
1182 addRelocationForSection(RE, Value.SectionID);
1184 resolveRelocation(Section, Offset,
1185 (uint64_t)Section.Address + Section.StubOffset, RelType,
1187 Section.StubOffset += getMaxStubSize();
1190 uint32_t *Placeholder =
1191 reinterpret_cast<uint32_t*>(computePlaceholderAddress(SectionID, Offset));
1192 if (RelType == ELF::R_ARM_PREL31 || RelType == ELF::R_ARM_TARGET1 ||
1193 RelType == ELF::R_ARM_ABS32) {
1194 Value.Addend += *Placeholder;
1195 } else if (RelType == ELF::R_ARM_MOVW_ABS_NC || RelType == ELF::R_ARM_MOVT_ABS) {
1196 // See ELF for ARM documentation
1197 Value.Addend += (int16_t)((*Placeholder & 0xFFF) | (((*Placeholder >> 16) & 0xF) << 12));
1199 processSimpleRelocation(SectionID, Offset, RelType, Value);
1201 } else if (IsMipsO32ABI) {
1202 uint32_t *Placeholder = reinterpret_cast<uint32_t*>(computePlaceholderAddress(SectionID, Offset));
1203 if (RelType == ELF::R_MIPS_26) {
1204 // This is an Mips branch relocation, need to use a stub function.
1205 DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
1206 SectionEntry &Section = Sections[SectionID];
1208 // Extract the addend from the instruction.
1209 // We shift up by two since the Value will be down shifted again
1210 // when applying the relocation.
1211 uint32_t Addend = ((*Placeholder) & 0x03ffffff) << 2;
1213 Value.Addend += Addend;
1215 // Look up for existing stub.
1216 StubMap::const_iterator i = Stubs.find(Value);
1217 if (i != Stubs.end()) {
1218 RelocationEntry RE(SectionID, Offset, RelType, i->second);
1219 addRelocationForSection(RE, SectionID);
1220 DEBUG(dbgs() << " Stub function found\n");
1222 // Create a new stub function.
1223 DEBUG(dbgs() << " Create a new stub function\n");
1224 Stubs[Value] = Section.StubOffset;
1225 uint8_t *StubTargetAddr =
1226 createStubFunction(Section.Address + Section.StubOffset);
1228 // Creating Hi and Lo relocations for the filled stub instructions.
1229 RelocationEntry REHi(SectionID, StubTargetAddr - Section.Address,
1230 ELF::R_MIPS_HI16, Value.Addend);
1231 RelocationEntry RELo(SectionID, StubTargetAddr - Section.Address + 4,
1232 ELF::R_MIPS_LO16, Value.Addend);
1234 if (Value.SymbolName) {
1235 addRelocationForSymbol(REHi, Value.SymbolName);
1236 addRelocationForSymbol(RELo, Value.SymbolName);
1239 addRelocationForSection(REHi, Value.SectionID);
1240 addRelocationForSection(RELo, Value.SectionID);
1243 RelocationEntry RE(SectionID, Offset, RelType, Section.StubOffset);
1244 addRelocationForSection(RE, SectionID);
1245 Section.StubOffset += getMaxStubSize();
1248 if (RelType == ELF::R_MIPS_HI16)
1249 Value.Addend += ((*Placeholder) & 0x0000ffff) << 16;
1250 else if (RelType == ELF::R_MIPS_LO16)
1251 Value.Addend += ((*Placeholder) & 0x0000ffff);
1252 else if (RelType == ELF::R_MIPS_32)
1253 Value.Addend += *Placeholder;
1254 processSimpleRelocation(SectionID, Offset, RelType, Value);
1256 } else if (IsMipsN64ABI) {
1257 uint32_t r_type = RelType & 0xff;
1258 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1259 if (r_type == ELF::R_MIPS_CALL16 || r_type == ELF::R_MIPS_GOT_PAGE
1260 || r_type == ELF::R_MIPS_GOT_DISP) {
1261 StringMap<uint64_t>::iterator i = GOTSymbolOffsets.find(TargetName);
1262 if (i != GOTSymbolOffsets.end())
1263 RE.SymOffset = i->second;
1265 RE.SymOffset = allocateGOTEntries(SectionID, 1);
1266 GOTSymbolOffsets[TargetName] = RE.SymOffset;
1269 if (Value.SymbolName)
1270 addRelocationForSymbol(RE, Value.SymbolName);
1272 addRelocationForSection(RE, Value.SectionID);
1273 } else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) {
1274 if (RelType == ELF::R_PPC64_REL24) {
1275 // Determine ABI variant in use for this object.
1276 unsigned AbiVariant;
1277 Obj.getPlatformFlags(AbiVariant);
1278 AbiVariant &= ELF::EF_PPC64_ABI;
1279 // A PPC branch relocation will need a stub function if the target is
1280 // an external symbol (Symbol::ST_Unknown) or if the target address
1281 // is not within the signed 24-bits branch address.
1282 SectionEntry &Section = Sections[SectionID];
1283 uint8_t *Target = Section.Address + Offset;
1284 bool RangeOverflow = false;
1285 if (SymType != SymbolRef::ST_Unknown) {
1286 if (AbiVariant != 2) {
1287 // In the ELFv1 ABI, a function call may point to the .opd entry,
1288 // so the final symbol value is calculated based on the relocation
1289 // values in the .opd section.
1290 findOPDEntrySection(Obj, ObjSectionToID, Value);
1292 // In the ELFv2 ABI, a function symbol may provide a local entry
1293 // point, which must be used for direct calls.
1295 Symbol->getOther(SymOther);
1296 Value.Addend += ELF::decodePPC64LocalEntryOffset(SymOther);
1298 uint8_t *RelocTarget = Sections[Value.SectionID].Address + Value.Addend;
1299 int32_t delta = static_cast<int32_t>(Target - RelocTarget);
1300 // If it is within 24-bits branch range, just set the branch target
1301 if (SignExtend32<24>(delta) == delta) {
1302 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1303 if (Value.SymbolName)
1304 addRelocationForSymbol(RE, Value.SymbolName);
1306 addRelocationForSection(RE, Value.SectionID);
1308 RangeOverflow = true;
1311 if (SymType == SymbolRef::ST_Unknown || RangeOverflow) {
1312 // It is an external symbol (SymbolRef::ST_Unknown) or within a range
1313 // larger than 24-bits.
1314 StubMap::const_iterator i = Stubs.find(Value);
1315 if (i != Stubs.end()) {
1316 // Symbol function stub already created, just relocate to it
1317 resolveRelocation(Section, Offset,
1318 (uint64_t)Section.Address + i->second, RelType, 0);
1319 DEBUG(dbgs() << " Stub function found\n");
1321 // Create a new stub function.
1322 DEBUG(dbgs() << " Create a new stub function\n");
1323 Stubs[Value] = Section.StubOffset;
1324 uint8_t *StubTargetAddr =
1325 createStubFunction(Section.Address + Section.StubOffset,
1327 RelocationEntry RE(SectionID, StubTargetAddr - Section.Address,
1328 ELF::R_PPC64_ADDR64, Value.Addend);
1330 // Generates the 64-bits address loads as exemplified in section
1331 // 4.5.1 in PPC64 ELF ABI. Note that the relocations need to
1332 // apply to the low part of the instructions, so we have to update
1333 // the offset according to the target endianness.
1334 uint64_t StubRelocOffset = StubTargetAddr - Section.Address;
1335 if (!IsTargetLittleEndian)
1336 StubRelocOffset += 2;
1338 RelocationEntry REhst(SectionID, StubRelocOffset + 0,
1339 ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend);
1340 RelocationEntry REhr(SectionID, StubRelocOffset + 4,
1341 ELF::R_PPC64_ADDR16_HIGHER, Value.Addend);
1342 RelocationEntry REh(SectionID, StubRelocOffset + 12,
1343 ELF::R_PPC64_ADDR16_HI, Value.Addend);
1344 RelocationEntry REl(SectionID, StubRelocOffset + 16,
1345 ELF::R_PPC64_ADDR16_LO, Value.Addend);
1347 if (Value.SymbolName) {
1348 addRelocationForSymbol(REhst, Value.SymbolName);
1349 addRelocationForSymbol(REhr, Value.SymbolName);
1350 addRelocationForSymbol(REh, Value.SymbolName);
1351 addRelocationForSymbol(REl, Value.SymbolName);
1353 addRelocationForSection(REhst, Value.SectionID);
1354 addRelocationForSection(REhr, Value.SectionID);
1355 addRelocationForSection(REh, Value.SectionID);
1356 addRelocationForSection(REl, Value.SectionID);
1359 resolveRelocation(Section, Offset,
1360 (uint64_t)Section.Address + Section.StubOffset,
1362 Section.StubOffset += getMaxStubSize();
1364 if (SymType == SymbolRef::ST_Unknown) {
1365 // Restore the TOC for external calls
1366 if (AbiVariant == 2)
1367 writeInt32BE(Target + 4, 0xE8410018); // ld r2,28(r1)
1369 writeInt32BE(Target + 4, 0xE8410028); // ld r2,40(r1)
1372 } else if (RelType == ELF::R_PPC64_TOC16 ||
1373 RelType == ELF::R_PPC64_TOC16_DS ||
1374 RelType == ELF::R_PPC64_TOC16_LO ||
1375 RelType == ELF::R_PPC64_TOC16_LO_DS ||
1376 RelType == ELF::R_PPC64_TOC16_HI ||
1377 RelType == ELF::R_PPC64_TOC16_HA) {
1378 // These relocations are supposed to subtract the TOC address from
1379 // the final value. This does not fit cleanly into the RuntimeDyld
1380 // scheme, since there may be *two* sections involved in determining
1381 // the relocation value (the section of the symbol refered to by the
1382 // relocation, and the TOC section associated with the current module).
1384 // Fortunately, these relocations are currently only ever generated
1385 // refering to symbols that themselves reside in the TOC, which means
1386 // that the two sections are actually the same. Thus they cancel out
1387 // and we can immediately resolve the relocation right now.
1389 case ELF::R_PPC64_TOC16: RelType = ELF::R_PPC64_ADDR16; break;
1390 case ELF::R_PPC64_TOC16_DS: RelType = ELF::R_PPC64_ADDR16_DS; break;
1391 case ELF::R_PPC64_TOC16_LO: RelType = ELF::R_PPC64_ADDR16_LO; break;
1392 case ELF::R_PPC64_TOC16_LO_DS: RelType = ELF::R_PPC64_ADDR16_LO_DS; break;
1393 case ELF::R_PPC64_TOC16_HI: RelType = ELF::R_PPC64_ADDR16_HI; break;
1394 case ELF::R_PPC64_TOC16_HA: RelType = ELF::R_PPC64_ADDR16_HA; break;
1395 default: llvm_unreachable("Wrong relocation type.");
1398 RelocationValueRef TOCValue;
1399 findPPC64TOCSection(Obj, ObjSectionToID, TOCValue);
1400 if (Value.SymbolName || Value.SectionID != TOCValue.SectionID)
1401 llvm_unreachable("Unsupported TOC relocation.");
1402 Value.Addend -= TOCValue.Addend;
1403 resolveRelocation(Sections[SectionID], Offset, Value.Addend, RelType, 0);
1405 // There are two ways to refer to the TOC address directly: either
1406 // via a ELF::R_PPC64_TOC relocation (where both symbol and addend are
1407 // ignored), or via any relocation that refers to the magic ".TOC."
1408 // symbols (in which case the addend is respected).
1409 if (RelType == ELF::R_PPC64_TOC) {
1410 RelType = ELF::R_PPC64_ADDR64;
1411 findPPC64TOCSection(Obj, ObjSectionToID, Value);
1412 } else if (TargetName == ".TOC.") {
1413 findPPC64TOCSection(Obj, ObjSectionToID, Value);
1414 Value.Addend += Addend;
1417 RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1419 if (Value.SymbolName)
1420 addRelocationForSymbol(RE, Value.SymbolName);
1422 addRelocationForSection(RE, Value.SectionID);
1424 } else if (Arch == Triple::systemz &&
1425 (RelType == ELF::R_390_PLT32DBL || RelType == ELF::R_390_GOTENT)) {
1426 // Create function stubs for both PLT and GOT references, regardless of
1427 // whether the GOT reference is to data or code. The stub contains the
1428 // full address of the symbol, as needed by GOT references, and the
1429 // executable part only adds an overhead of 8 bytes.
1431 // We could try to conserve space by allocating the code and data
1432 // parts of the stub separately. However, as things stand, we allocate
1433 // a stub for every relocation, so using a GOT in JIT code should be
1434 // no less space efficient than using an explicit constant pool.
1435 DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation.");
1436 SectionEntry &Section = Sections[SectionID];
1438 // Look for an existing stub.
1439 StubMap::const_iterator i = Stubs.find(Value);
1440 uintptr_t StubAddress;
1441 if (i != Stubs.end()) {
1442 StubAddress = uintptr_t(Section.Address) + i->second;
1443 DEBUG(dbgs() << " Stub function found\n");
1445 // Create a new stub function.
1446 DEBUG(dbgs() << " Create a new stub function\n");
1448 uintptr_t BaseAddress = uintptr_t(Section.Address);
1449 uintptr_t StubAlignment = getStubAlignment();
1450 StubAddress = (BaseAddress + Section.StubOffset + StubAlignment - 1) &
1452 unsigned StubOffset = StubAddress - BaseAddress;
1454 Stubs[Value] = StubOffset;
1455 createStubFunction((uint8_t *)StubAddress);
1456 RelocationEntry RE(SectionID, StubOffset + 8, ELF::R_390_64,
1458 if (Value.SymbolName)
1459 addRelocationForSymbol(RE, Value.SymbolName);
1461 addRelocationForSection(RE, Value.SectionID);
1462 Section.StubOffset = StubOffset + getMaxStubSize();
1465 if (RelType == ELF::R_390_GOTENT)
1466 resolveRelocation(Section, Offset, StubAddress + 8, ELF::R_390_PC32DBL,
1469 resolveRelocation(Section, Offset, StubAddress, RelType, Addend);
1470 } else if (Arch == Triple::x86_64) {
1471 if (RelType == ELF::R_X86_64_PLT32) {
1472 // The way the PLT relocations normally work is that the linker allocates
1474 // PLT and this relocation makes a PC-relative call into the PLT. The PLT
1475 // entry will then jump to an address provided by the GOT. On first call,
1477 // GOT address will point back into PLT code that resolves the symbol. After
1478 // the first call, the GOT entry points to the actual function.
1480 // For local functions we're ignoring all of that here and just replacing
1481 // the PLT32 relocation type with PC32, which will translate the relocation
1482 // into a PC-relative call directly to the function. For external symbols we
1483 // can't be sure the function will be within 2^32 bytes of the call site, so
1484 // we need to create a stub, which calls into the GOT. This case is
1485 // equivalent to the usual PLT implementation except that we use the stub
1486 // mechanism in RuntimeDyld (which puts stubs at the end of the section)
1487 // rather than allocating a PLT section.
1488 if (Value.SymbolName) {
1489 // This is a call to an external function.
1490 // Look for an existing stub.
1491 SectionEntry &Section = Sections[SectionID];
1492 StubMap::const_iterator i = Stubs.find(Value);
1493 uintptr_t StubAddress;
1494 if (i != Stubs.end()) {
1495 StubAddress = uintptr_t(Section.Address) + i->second;
1496 DEBUG(dbgs() << " Stub function found\n");
1498 // Create a new stub function (equivalent to a PLT entry).
1499 DEBUG(dbgs() << " Create a new stub function\n");
1501 uintptr_t BaseAddress = uintptr_t(Section.Address);
1502 uintptr_t StubAlignment = getStubAlignment();
1503 StubAddress = (BaseAddress + Section.StubOffset + StubAlignment - 1) &
1505 unsigned StubOffset = StubAddress - BaseAddress;
1506 Stubs[Value] = StubOffset;
1507 createStubFunction((uint8_t *)StubAddress);
1509 // Bump our stub offset counter
1510 Section.StubOffset = StubOffset + getMaxStubSize();
1512 // Allocate a GOT Entry
1513 uint64_t GOTOffset = allocateGOTEntries(SectionID, 1);
1515 // The load of the GOT address has an addend of -4
1516 resolveGOTOffsetRelocation(SectionID, StubOffset + 2, GOTOffset - 4);
1518 // Fill in the value of the symbol we're targeting into the GOT
1519 addRelocationForSymbol(computeGOTOffsetRE(SectionID,GOTOffset,0,ELF::R_X86_64_64),
1523 // Make the target call a call into the stub table.
1524 resolveRelocation(Section, Offset, StubAddress, ELF::R_X86_64_PC32,
1527 RelocationEntry RE(SectionID, Offset, ELF::R_X86_64_PC32, Value.Addend,
1529 addRelocationForSection(RE, Value.SectionID);
1531 } else if (RelType == ELF::R_X86_64_GOTPCREL) {
1532 uint64_t GOTOffset = allocateGOTEntries(SectionID, 1);
1533 resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend);
1535 // Fill in the value of the symbol we're targeting into the GOT
1536 RelocationEntry RE = computeGOTOffsetRE(SectionID, GOTOffset, Value.Offset, ELF::R_X86_64_64);
1537 if (Value.SymbolName)
1538 addRelocationForSymbol(RE, Value.SymbolName);
1540 addRelocationForSection(RE, Value.SectionID);
1541 } else if (RelType == ELF::R_X86_64_PC32) {
1542 Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset));
1543 processSimpleRelocation(SectionID, Offset, RelType, Value);
1544 } else if (RelType == ELF::R_X86_64_PC64) {
1545 Value.Addend += support::ulittle64_t::ref(computePlaceholderAddress(SectionID, Offset));
1546 processSimpleRelocation(SectionID, Offset, RelType, Value);
1548 processSimpleRelocation(SectionID, Offset, RelType, Value);
1551 if (Arch == Triple::x86) {
1552 Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset));
1554 processSimpleRelocation(SectionID, Offset, RelType, Value);
1559 size_t RuntimeDyldELF::getGOTEntrySize() {
1560 // We don't use the GOT in all of these cases, but it's essentially free
1561 // to put them all here.
1564 case Triple::x86_64:
1565 case Triple::aarch64:
1566 case Triple::aarch64_be:
1568 case Triple::ppc64le:
1569 case Triple::systemz:
1570 Result = sizeof(uint64_t);
1575 Result = sizeof(uint32_t);
1578 case Triple::mipsel:
1579 case Triple::mips64:
1580 case Triple::mips64el:
1582 Result = sizeof(uint32_t);
1583 else if (IsMipsN64ABI)
1584 Result = sizeof(uint64_t);
1586 llvm_unreachable("Mips ABI not handled");
1589 llvm_unreachable("Unsupported CPU type!");
1594 uint64_t RuntimeDyldELF::allocateGOTEntries(unsigned SectionID, unsigned no)
1596 (void)SectionID; // The GOT Section is the same for all section in the object file
1597 if (GOTSectionID == 0) {
1598 GOTSectionID = Sections.size();
1599 // Reserve a section id. We'll allocate the section later
1600 // once we know the total size
1601 Sections.push_back(SectionEntry(".got", 0, 0, 0));
1603 uint64_t StartOffset = CurrentGOTIndex * getGOTEntrySize();
1604 CurrentGOTIndex += no;
1608 void RuntimeDyldELF::resolveGOTOffsetRelocation(unsigned SectionID, uint64_t Offset, uint64_t GOTOffset)
1610 // Fill in the relative address of the GOT Entry into the stub
1611 RelocationEntry GOTRE(SectionID, Offset, ELF::R_X86_64_PC32, GOTOffset);
1612 addRelocationForSection(GOTRE, GOTSectionID);
1615 RelocationEntry RuntimeDyldELF::computeGOTOffsetRE(unsigned SectionID, uint64_t GOTOffset, uint64_t SymbolOffset,
1618 (void)SectionID; // The GOT Section is the same for all section in the object file
1619 return RelocationEntry(GOTSectionID, GOTOffset, Type, SymbolOffset);
1622 void RuntimeDyldELF::finalizeLoad(const ObjectFile &Obj,
1623 ObjSectionToIDMap &SectionMap) {
1624 // If necessary, allocate the global offset table
1625 if (GOTSectionID != 0) {
1626 // Allocate memory for the section
1627 size_t TotalSize = CurrentGOTIndex * getGOTEntrySize();
1628 uint8_t *Addr = MemMgr.allocateDataSection(TotalSize, getGOTEntrySize(),
1629 GOTSectionID, ".got", false);
1631 report_fatal_error("Unable to allocate memory for GOT!");
1633 Sections[GOTSectionID] = SectionEntry(".got", Addr, TotalSize, 0);
1636 Checker->registerSection(Obj.getFileName(), GOTSectionID);
1638 // For now, initialize all GOT entries to zero. We'll fill them in as
1639 // needed when GOT-based relocations are applied.
1640 memset(Addr, 0, TotalSize);
1642 // To correctly resolve Mips GOT relocations, we need a mapping from
1643 // object's sections to GOTs.
1644 for (section_iterator SI = Obj.section_begin(), SE = Obj.section_end();
1646 if (SI->relocation_begin() != SI->relocation_end()) {
1647 section_iterator RelocatedSection = SI->getRelocatedSection();
1648 ObjSectionToIDMap::iterator i = SectionMap.find(*RelocatedSection);
1649 assert (i != SectionMap.end());
1650 SectionToGOTMap[i->second] = GOTSectionID;
1653 GOTSymbolOffsets.clear();
1657 // Look for and record the EH frame section.
1658 ObjSectionToIDMap::iterator i, e;
1659 for (i = SectionMap.begin(), e = SectionMap.end(); i != e; ++i) {
1660 const SectionRef &Section = i->first;
1662 Section.getName(Name);
1663 if (Name == ".eh_frame") {
1664 UnregisteredEHFrameSections.push_back(i->second);
1670 CurrentGOTIndex = 0;
1673 bool RuntimeDyldELF::isCompatibleFile(const object::ObjectFile &Obj) const {