LLVM  4.0.0
RuntimeDyldELF.cpp
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1 //===-- RuntimeDyldELF.cpp - Run-time dynamic linker for MC-JIT -*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // Implementation of ELF support for the MC-JIT runtime dynamic linker.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "RuntimeDyldELF.h"
15 #include "RuntimeDyldCheckerImpl.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/MC/MCStreamer.h"
23 #include "llvm/Object/ObjectFile.h"
24 #include "llvm/Support/ELF.h"
25 #include "llvm/Support/Endian.h"
28 
29 using namespace llvm;
30 using namespace llvm::object;
31 using namespace llvm::support::endian;
32 
33 #define DEBUG_TYPE "dyld"
34 
35 static void or32le(void *P, int32_t V) { write32le(P, read32le(P) | V); }
36 
37 static void or32AArch64Imm(void *L, uint64_t Imm) {
38  or32le(L, (Imm & 0xFFF) << 10);
39 }
40 
41 template <class T> static void write(bool isBE, void *P, T V) {
42  isBE ? write<T, support::big>(P, V) : write<T, support::little>(P, V);
43 }
44 
45 static void write32AArch64Addr(void *L, uint64_t Imm) {
46  uint32_t ImmLo = (Imm & 0x3) << 29;
47  uint32_t ImmHi = (Imm & 0x1FFFFC) << 3;
48  uint64_t Mask = (0x3 << 29) | (0x1FFFFC << 3);
49  write32le(L, (read32le(L) & ~Mask) | ImmLo | ImmHi);
50 }
51 
52 // Return the bits [Start, End] from Val shifted Start bits.
53 // For instance, getBits(0xF0, 4, 8) returns 0xF.
54 static uint64_t getBits(uint64_t Val, int Start, int End) {
55  uint64_t Mask = ((uint64_t)1 << (End + 1 - Start)) - 1;
56  return (Val >> Start) & Mask;
57 }
58 
59 namespace {
60 
61 template <class ELFT> class DyldELFObject : public ELFObjectFile<ELFT> {
63 
64  typedef Elf_Shdr_Impl<ELFT> Elf_Shdr;
65  typedef Elf_Sym_Impl<ELFT> Elf_Sym;
66  typedef Elf_Rel_Impl<ELFT, false> Elf_Rel;
67  typedef Elf_Rel_Impl<ELFT, true> Elf_Rela;
68 
69  typedef Elf_Ehdr_Impl<ELFT> Elf_Ehdr;
70 
71  typedef typename ELFDataTypeTypedefHelper<ELFT>::value_type addr_type;
72 
73 public:
74  DyldELFObject(MemoryBufferRef Wrapper, std::error_code &ec);
75 
76  void updateSectionAddress(const SectionRef &Sec, uint64_t Addr);
77 
78  void updateSymbolAddress(const SymbolRef &SymRef, uint64_t Addr);
79 
80  // Methods for type inquiry through isa, cast and dyn_cast
81  static inline bool classof(const Binary *v) {
82  return (isa<ELFObjectFile<ELFT>>(v) &&
83  classof(cast<ELFObjectFile<ELFT>>(v)));
84  }
85  static inline bool classof(const ELFObjectFile<ELFT> *v) {
86  return v->isDyldType();
87  }
88 };
89 
90 
91 
92 // The MemoryBuffer passed into this constructor is just a wrapper around the
93 // actual memory. Ultimately, the Binary parent class will take ownership of
94 // this MemoryBuffer object but not the underlying memory.
95 template <class ELFT>
96 DyldELFObject<ELFT>::DyldELFObject(MemoryBufferRef Wrapper, std::error_code &EC)
97  : ELFObjectFile<ELFT>(Wrapper, EC) {
98  this->isDyldELFObject = true;
99 }
100 
101 template <class ELFT>
102 void DyldELFObject<ELFT>::updateSectionAddress(const SectionRef &Sec,
103  uint64_t Addr) {
104  DataRefImpl ShdrRef = Sec.getRawDataRefImpl();
105  Elf_Shdr *shdr =
106  const_cast<Elf_Shdr *>(reinterpret_cast<const Elf_Shdr *>(ShdrRef.p));
107 
108  // This assumes the address passed in matches the target address bitness
109  // The template-based type cast handles everything else.
110  shdr->sh_addr = static_cast<addr_type>(Addr);
111 }
112 
113 template <class ELFT>
114 void DyldELFObject<ELFT>::updateSymbolAddress(const SymbolRef &SymRef,
115  uint64_t Addr) {
116 
117  Elf_Sym *sym = const_cast<Elf_Sym *>(
119 
120  // This assumes the address passed in matches the target address bitness
121  // The template-based type cast handles everything else.
122  sym->st_value = static_cast<addr_type>(Addr);
123 }
124 
125 class LoadedELFObjectInfo final
126  : public RuntimeDyld::LoadedObjectInfoHelper<LoadedELFObjectInfo> {
127 public:
128  LoadedELFObjectInfo(RuntimeDyldImpl &RTDyld, ObjSectionToIDMap ObjSecToIDMap)
129  : LoadedObjectInfoHelper(RTDyld, std::move(ObjSecToIDMap)) {}
130 
132  getObjectForDebug(const ObjectFile &Obj) const override;
133 };
134 
135 template <typename ELFT>
136 std::unique_ptr<DyldELFObject<ELFT>>
137 createRTDyldELFObject(MemoryBufferRef Buffer,
138  const ObjectFile &SourceObject,
139  const LoadedELFObjectInfo &L,
140  std::error_code &ec) {
141  typedef typename ELFFile<ELFT>::Elf_Shdr Elf_Shdr;
142  typedef typename ELFDataTypeTypedefHelper<ELFT>::value_type addr_type;
143 
144  std::unique_ptr<DyldELFObject<ELFT>> Obj =
145  llvm::make_unique<DyldELFObject<ELFT>>(Buffer, ec);
146 
147  // Iterate over all sections in the object.
148  auto SI = SourceObject.section_begin();
149  for (const auto &Sec : Obj->sections()) {
151  Sec.getName(SectionName);
152  if (SectionName != "") {
153  DataRefImpl ShdrRef = Sec.getRawDataRefImpl();
154  Elf_Shdr *shdr = const_cast<Elf_Shdr *>(
155  reinterpret_cast<const Elf_Shdr *>(ShdrRef.p));
156 
157  if (uint64_t SecLoadAddr = L.getSectionLoadAddress(*SI)) {
158  // This assumes that the address passed in matches the target address
159  // bitness. The template-based type cast handles everything else.
160  shdr->sh_addr = static_cast<addr_type>(SecLoadAddr);
161  }
162  }
163  ++SI;
164  }
165 
166  return Obj;
167 }
168 
169 OwningBinary<ObjectFile> createELFDebugObject(const ObjectFile &Obj,
170  const LoadedELFObjectInfo &L) {
171  assert(Obj.isELF() && "Not an ELF object file.");
172 
173  std::unique_ptr<MemoryBuffer> Buffer =
174  MemoryBuffer::getMemBufferCopy(Obj.getData(), Obj.getFileName());
175 
176  std::error_code ec;
177 
178  std::unique_ptr<ObjectFile> DebugObj;
179  if (Obj.getBytesInAddress() == 4 && Obj.isLittleEndian()) {
181  DebugObj = createRTDyldELFObject<ELF32LE>(Buffer->getMemBufferRef(), Obj, L,
182  ec);
183  } else if (Obj.getBytesInAddress() == 4 && !Obj.isLittleEndian()) {
185  DebugObj = createRTDyldELFObject<ELF32BE>(Buffer->getMemBufferRef(), Obj, L,
186  ec);
187  } else if (Obj.getBytesInAddress() == 8 && !Obj.isLittleEndian()) {
189  DebugObj = createRTDyldELFObject<ELF64BE>(Buffer->getMemBufferRef(), Obj, L,
190  ec);
191  } else if (Obj.getBytesInAddress() == 8 && Obj.isLittleEndian()) {
193  DebugObj = createRTDyldELFObject<ELF64LE>(Buffer->getMemBufferRef(), Obj, L,
194  ec);
195  } else
196  llvm_unreachable("Unexpected ELF format");
197 
198  assert(!ec && "Could not construct copy ELF object file");
199 
200  return OwningBinary<ObjectFile>(std::move(DebugObj), std::move(Buffer));
201 }
202 
204 LoadedELFObjectInfo::getObjectForDebug(const ObjectFile &Obj) const {
205  return createELFDebugObject(Obj, *this);
206 }
207 
208 } // anonymous namespace
209 
210 namespace llvm {
211 
213  JITSymbolResolver &Resolver)
214  : RuntimeDyldImpl(MemMgr, Resolver), GOTSectionID(0), CurrentGOTIndex(0) {}
216 
218  for (int i = 0, e = UnregisteredEHFrameSections.size(); i != e; ++i) {
219  SID EHFrameSID = UnregisteredEHFrameSections[i];
220  uint8_t *EHFrameAddr = Sections[EHFrameSID].getAddress();
221  uint64_t EHFrameLoadAddr = Sections[EHFrameSID].getLoadAddress();
222  size_t EHFrameSize = Sections[EHFrameSID].getSize();
223  MemMgr.registerEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
224  RegisteredEHFrameSections.push_back(EHFrameSID);
225  }
226  UnregisteredEHFrameSections.clear();
227 }
228 
230  for (int i = 0, e = RegisteredEHFrameSections.size(); i != e; ++i) {
231  SID EHFrameSID = RegisteredEHFrameSections[i];
232  uint8_t *EHFrameAddr = Sections[EHFrameSID].getAddress();
233  uint64_t EHFrameLoadAddr = Sections[EHFrameSID].getLoadAddress();
234  size_t EHFrameSize = Sections[EHFrameSID].getSize();
235  MemMgr.deregisterEHFrames(EHFrameAddr, EHFrameLoadAddr, EHFrameSize);
236  }
237  RegisteredEHFrameSections.clear();
238 }
239 
240 std::unique_ptr<RuntimeDyldELF>
243  JITSymbolResolver &Resolver) {
244  switch (Arch) {
245  default:
246  return make_unique<RuntimeDyldELF>(MemMgr, Resolver);
247  case Triple::mips:
248  case Triple::mipsel:
249  case Triple::mips64:
250  case Triple::mips64el:
251  return make_unique<RuntimeDyldELFMips>(MemMgr, Resolver);
252  }
253 }
254 
255 std::unique_ptr<RuntimeDyld::LoadedObjectInfo>
257  if (auto ObjSectionToIDOrErr = loadObjectImpl(O))
258  return llvm::make_unique<LoadedELFObjectInfo>(*this, *ObjSectionToIDOrErr);
259  else {
260  HasError = true;
261  raw_string_ostream ErrStream(ErrorStr);
262  logAllUnhandledErrors(ObjSectionToIDOrErr.takeError(), ErrStream, "");
263  return nullptr;
264  }
265 }
266 
267 void RuntimeDyldELF::resolveX86_64Relocation(const SectionEntry &Section,
268  uint64_t Offset, uint64_t Value,
269  uint32_t Type, int64_t Addend,
270  uint64_t SymOffset) {
271  switch (Type) {
272  default:
273  llvm_unreachable("Relocation type not implemented yet!");
274  break;
275  case ELF::R_X86_64_64: {
277  Value + Addend;
278  DEBUG(dbgs() << "Writing " << format("%p", (Value + Addend)) << " at "
279  << format("%p\n", Section.getAddressWithOffset(Offset)));
280  break;
281  }
282  case ELF::R_X86_64_32:
283  case ELF::R_X86_64_32S: {
284  Value += Addend;
285  assert((Type == ELF::R_X86_64_32 && (Value <= UINT32_MAX)) ||
286  (Type == ELF::R_X86_64_32S &&
287  ((int64_t)Value <= INT32_MAX && (int64_t)Value >= INT32_MIN)));
288  uint32_t TruncatedAddr = (Value & 0xFFFFFFFF);
290  TruncatedAddr;
291  DEBUG(dbgs() << "Writing " << format("%p", TruncatedAddr) << " at "
292  << format("%p\n", Section.getAddressWithOffset(Offset)));
293  break;
294  }
295  case ELF::R_X86_64_PC8: {
296  uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
297  int64_t RealOffset = Value + Addend - FinalAddress;
298  assert(isInt<8>(RealOffset));
299  int8_t TruncOffset = (RealOffset & 0xFF);
300  Section.getAddress()[Offset] = TruncOffset;
301  break;
302  }
303  case ELF::R_X86_64_PC32: {
304  uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
305  int64_t RealOffset = Value + Addend - FinalAddress;
306  assert(isInt<32>(RealOffset));
307  int32_t TruncOffset = (RealOffset & 0xFFFFFFFF);
309  TruncOffset;
310  break;
311  }
312  case ELF::R_X86_64_PC64: {
313  uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
314  int64_t RealOffset = Value + Addend - FinalAddress;
316  RealOffset;
317  break;
318  }
319  }
320 }
321 
322 void RuntimeDyldELF::resolveX86Relocation(const SectionEntry &Section,
323  uint64_t Offset, uint32_t Value,
324  uint32_t Type, int32_t Addend) {
325  switch (Type) {
326  case ELF::R_386_32: {
328  Value + Addend;
329  break;
330  }
331  case ELF::R_386_PC32: {
332  uint32_t FinalAddress =
333  Section.getLoadAddressWithOffset(Offset) & 0xFFFFFFFF;
334  uint32_t RealOffset = Value + Addend - FinalAddress;
336  RealOffset;
337  break;
338  }
339  default:
340  // There are other relocation types, but it appears these are the
341  // only ones currently used by the LLVM ELF object writer
342  llvm_unreachable("Relocation type not implemented yet!");
343  break;
344  }
345 }
346 
347 void RuntimeDyldELF::resolveAArch64Relocation(const SectionEntry &Section,
348  uint64_t Offset, uint64_t Value,
349  uint32_t Type, int64_t Addend) {
350  uint32_t *TargetPtr =
351  reinterpret_cast<uint32_t *>(Section.getAddressWithOffset(Offset));
352  uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
353  // Data should use target endian. Code should always use little endian.
354  bool isBE = Arch == Triple::aarch64_be;
355 
356  DEBUG(dbgs() << "resolveAArch64Relocation, LocalAddress: 0x"
357  << format("%llx", Section.getAddressWithOffset(Offset))
358  << " FinalAddress: 0x" << format("%llx", FinalAddress)
359  << " Value: 0x" << format("%llx", Value) << " Type: 0x"
360  << format("%x", Type) << " Addend: 0x" << format("%llx", Addend)
361  << "\n");
362 
363  switch (Type) {
364  default:
365  llvm_unreachable("Relocation type not implemented yet!");
366  break;
367  case ELF::R_AARCH64_ABS64:
368  write(isBE, TargetPtr, Value + Addend);
369  break;
370  case ELF::R_AARCH64_PREL32: {
371  uint64_t Result = Value + Addend - FinalAddress;
372  assert(static_cast<int64_t>(Result) >= INT32_MIN &&
373  static_cast<int64_t>(Result) <= UINT32_MAX);
374  write(isBE, TargetPtr, static_cast<uint32_t>(Result & 0xffffffffU));
375  break;
376  }
377  case ELF::R_AARCH64_PREL64:
378  write(isBE, TargetPtr, Value + Addend - FinalAddress);
379  break;
380  case ELF::R_AARCH64_CALL26: // fallthrough
381  case ELF::R_AARCH64_JUMP26: {
382  // Operation: S+A-P. Set Call or B immediate value to bits fff_fffc of the
383  // calculation.
384  uint64_t BranchImm = Value + Addend - FinalAddress;
385 
386  // "Check that -2^27 <= result < 2^27".
387  assert(isInt<28>(BranchImm));
388  or32le(TargetPtr, (BranchImm & 0x0FFFFFFC) >> 2);
389  break;
390  }
391  case ELF::R_AARCH64_MOVW_UABS_G3:
392  or32le(TargetPtr, ((Value + Addend) & 0xFFFF000000000000) >> 43);
393  break;
394  case ELF::R_AARCH64_MOVW_UABS_G2_NC:
395  or32le(TargetPtr, ((Value + Addend) & 0xFFFF00000000) >> 27);
396  break;
397  case ELF::R_AARCH64_MOVW_UABS_G1_NC:
398  or32le(TargetPtr, ((Value + Addend) & 0xFFFF0000) >> 11);
399  break;
400  case ELF::R_AARCH64_MOVW_UABS_G0_NC:
401  or32le(TargetPtr, ((Value + Addend) & 0xFFFF) << 5);
402  break;
403  case ELF::R_AARCH64_ADR_PREL_PG_HI21: {
404  // Operation: Page(S+A) - Page(P)
405  uint64_t Result =
406  ((Value + Addend) & ~0xfffULL) - (FinalAddress & ~0xfffULL);
407 
408  // Check that -2^32 <= X < 2^32
409  assert(isInt<33>(Result) && "overflow check failed for relocation");
410 
411  // Immediate goes in bits 30:29 + 5:23 of ADRP instruction, taken
412  // from bits 32:12 of X.
413  write32AArch64Addr(TargetPtr, Result >> 12);
414  break;
415  }
416  case ELF::R_AARCH64_ADD_ABS_LO12_NC:
417  // Operation: S + A
418  // Immediate goes in bits 21:10 of LD/ST instruction, taken
419  // from bits 11:0 of X
420  or32AArch64Imm(TargetPtr, Value + Addend);
421  break;
422  case ELF::R_AARCH64_LDST32_ABS_LO12_NC:
423  // Operation: S + A
424  // Immediate goes in bits 21:10 of LD/ST instruction, taken
425  // from bits 11:2 of X
426  or32AArch64Imm(TargetPtr, getBits(Value + Addend, 2, 11));
427  break;
428  case ELF::R_AARCH64_LDST64_ABS_LO12_NC:
429  // Operation: S + A
430  // Immediate goes in bits 21:10 of LD/ST instruction, taken
431  // from bits 11:3 of X
432  or32AArch64Imm(TargetPtr, getBits(Value + Addend, 3, 11));
433  break;
434  }
435 }
436 
437 void RuntimeDyldELF::resolveARMRelocation(const SectionEntry &Section,
438  uint64_t Offset, uint32_t Value,
439  uint32_t Type, int32_t Addend) {
440  // TODO: Add Thumb relocations.
441  uint32_t *TargetPtr =
442  reinterpret_cast<uint32_t *>(Section.getAddressWithOffset(Offset));
443  uint32_t FinalAddress = Section.getLoadAddressWithOffset(Offset) & 0xFFFFFFFF;
444  Value += Addend;
445 
446  DEBUG(dbgs() << "resolveARMRelocation, LocalAddress: "
447  << Section.getAddressWithOffset(Offset)
448  << " FinalAddress: " << format("%p", FinalAddress) << " Value: "
449  << format("%x", Value) << " Type: " << format("%x", Type)
450  << " Addend: " << format("%x", Addend) << "\n");
451 
452  switch (Type) {
453  default:
454  llvm_unreachable("Not implemented relocation type!");
455 
456  case ELF::R_ARM_NONE:
457  break;
458  // Write a 31bit signed offset
459  case ELF::R_ARM_PREL31:
460  support::ulittle32_t::ref{TargetPtr} =
461  (support::ulittle32_t::ref{TargetPtr} & 0x80000000) |
462  ((Value - FinalAddress) & ~0x80000000);
463  break;
464  case ELF::R_ARM_TARGET1:
465  case ELF::R_ARM_ABS32:
466  support::ulittle32_t::ref{TargetPtr} = Value;
467  break;
468  // Write first 16 bit of 32 bit value to the mov instruction.
469  // Last 4 bit should be shifted.
470  case ELF::R_ARM_MOVW_ABS_NC:
471  case ELF::R_ARM_MOVT_ABS:
472  if (Type == ELF::R_ARM_MOVW_ABS_NC)
473  Value = Value & 0xFFFF;
474  else if (Type == ELF::R_ARM_MOVT_ABS)
475  Value = (Value >> 16) & 0xFFFF;
476  support::ulittle32_t::ref{TargetPtr} =
477  (support::ulittle32_t::ref{TargetPtr} & ~0x000F0FFF) | (Value & 0xFFF) |
478  (((Value >> 12) & 0xF) << 16);
479  break;
480  // Write 24 bit relative value to the branch instruction.
481  case ELF::R_ARM_PC24: // Fall through.
482  case ELF::R_ARM_CALL: // Fall through.
483  case ELF::R_ARM_JUMP24:
484  int32_t RelValue = static_cast<int32_t>(Value - FinalAddress - 8);
485  RelValue = (RelValue & 0x03FFFFFC) >> 2;
486  assert((support::ulittle32_t::ref{TargetPtr} & 0xFFFFFF) == 0xFFFFFE);
487  support::ulittle32_t::ref{TargetPtr} =
488  (support::ulittle32_t::ref{TargetPtr} & 0xFF000000) | RelValue;
489  break;
490  }
491 }
492 
493 void RuntimeDyldELF::setMipsABI(const ObjectFile &Obj) {
494  if (Arch == Triple::UnknownArch ||
495  !StringRef(Triple::getArchTypePrefix(Arch)).equals("mips")) {
496  IsMipsO32ABI = false;
497  IsMipsN32ABI = false;
498  IsMipsN64ABI = false;
499  return;
500  }
501  unsigned AbiVariant;
502  Obj.getPlatformFlags(AbiVariant);
503  IsMipsO32ABI = AbiVariant & ELF::EF_MIPS_ABI_O32;
504  IsMipsN32ABI = AbiVariant & ELF::EF_MIPS_ABI2;
505  IsMipsN64ABI = Obj.getFileFormatName().equals("ELF64-mips");
506 }
507 
508 // Return the .TOC. section and offset.
509 Error RuntimeDyldELF::findPPC64TOCSection(const ELFObjectFileBase &Obj,
510  ObjSectionToIDMap &LocalSections,
511  RelocationValueRef &Rel) {
512  // Set a default SectionID in case we do not find a TOC section below.
513  // This may happen for references to TOC base base (sym@toc, .odp
514  // relocation) without a .toc directive. In this case just use the
515  // first section (which is usually the .odp) since the code won't
516  // reference the .toc base directly.
517  Rel.SymbolName = nullptr;
518  Rel.SectionID = 0;
519 
520  // The TOC consists of sections .got, .toc, .tocbss, .plt in that
521  // order. The TOC starts where the first of these sections starts.
522  for (auto &Section: Obj.sections()) {
524  if (auto EC = Section.getName(SectionName))
525  return errorCodeToError(EC);
526 
527  if (SectionName == ".got"
528  || SectionName == ".toc"
529  || SectionName == ".tocbss"
530  || SectionName == ".plt") {
531  if (auto SectionIDOrErr =
532  findOrEmitSection(Obj, Section, false, LocalSections))
533  Rel.SectionID = *SectionIDOrErr;
534  else
535  return SectionIDOrErr.takeError();
536  break;
537  }
538  }
539 
540  // Per the ppc64-elf-linux ABI, The TOC base is TOC value plus 0x8000
541  // thus permitting a full 64 Kbytes segment.
542  Rel.Addend = 0x8000;
543 
544  return Error::success();
545 }
546 
547 // Returns the sections and offset associated with the ODP entry referenced
548 // by Symbol.
549 Error RuntimeDyldELF::findOPDEntrySection(const ELFObjectFileBase &Obj,
550  ObjSectionToIDMap &LocalSections,
551  RelocationValueRef &Rel) {
552  // Get the ELF symbol value (st_value) to compare with Relocation offset in
553  // .opd entries
554  for (section_iterator si = Obj.section_begin(), se = Obj.section_end();
555  si != se; ++si) {
556  section_iterator RelSecI = si->getRelocatedSection();
557  if (RelSecI == Obj.section_end())
558  continue;
559 
560  StringRef RelSectionName;
561  if (auto EC = RelSecI->getName(RelSectionName))
562  return errorCodeToError(EC);
563 
564  if (RelSectionName != ".opd")
565  continue;
566 
567  for (elf_relocation_iterator i = si->relocation_begin(),
568  e = si->relocation_end();
569  i != e;) {
570  // The R_PPC64_ADDR64 relocation indicates the first field
571  // of a .opd entry
572  uint64_t TypeFunc = i->getType();
573  if (TypeFunc != ELF::R_PPC64_ADDR64) {
574  ++i;
575  continue;
576  }
577 
578  uint64_t TargetSymbolOffset = i->getOffset();
579  symbol_iterator TargetSymbol = i->getSymbol();
580  int64_t Addend;
581  if (auto AddendOrErr = i->getAddend())
582  Addend = *AddendOrErr;
583  else
584  return errorCodeToError(AddendOrErr.getError());
585 
586  ++i;
587  if (i == e)
588  break;
589 
590  // Just check if following relocation is a R_PPC64_TOC
591  uint64_t TypeTOC = i->getType();
592  if (TypeTOC != ELF::R_PPC64_TOC)
593  continue;
594 
595  // Finally compares the Symbol value and the target symbol offset
596  // to check if this .opd entry refers to the symbol the relocation
597  // points to.
598  if (Rel.Addend != (int64_t)TargetSymbolOffset)
599  continue;
600 
601  section_iterator TSI = Obj.section_end();
602  if (auto TSIOrErr = TargetSymbol->getSection())
603  TSI = *TSIOrErr;
604  else
605  return TSIOrErr.takeError();
606  assert(TSI != Obj.section_end() && "TSI should refer to a valid section");
607 
608  bool IsCode = TSI->isText();
609  if (auto SectionIDOrErr = findOrEmitSection(Obj, *TSI, IsCode,
610  LocalSections))
611  Rel.SectionID = *SectionIDOrErr;
612  else
613  return SectionIDOrErr.takeError();
614  Rel.Addend = (intptr_t)Addend;
615  return Error::success();
616  }
617  }
618  llvm_unreachable("Attempting to get address of ODP entry!");
619 }
620 
621 // Relocation masks following the #lo(value), #hi(value), #ha(value),
622 // #higher(value), #highera(value), #highest(value), and #highesta(value)
623 // macros defined in section 4.5.1. Relocation Types of the PPC-elf64abi
624 // document.
625 
626 static inline uint16_t applyPPClo(uint64_t value) { return value & 0xffff; }
627 
628 static inline uint16_t applyPPChi(uint64_t value) {
629  return (value >> 16) & 0xffff;
630 }
631 
632 static inline uint16_t applyPPCha (uint64_t value) {
633  return ((value + 0x8000) >> 16) & 0xffff;
634 }
635 
636 static inline uint16_t applyPPChigher(uint64_t value) {
637  return (value >> 32) & 0xffff;
638 }
639 
640 static inline uint16_t applyPPChighera (uint64_t value) {
641  return ((value + 0x8000) >> 32) & 0xffff;
642 }
643 
644 static inline uint16_t applyPPChighest(uint64_t value) {
645  return (value >> 48) & 0xffff;
646 }
647 
648 static inline uint16_t applyPPChighesta (uint64_t value) {
649  return ((value + 0x8000) >> 48) & 0xffff;
650 }
651 
652 void RuntimeDyldELF::resolvePPC32Relocation(const SectionEntry &Section,
653  uint64_t Offset, uint64_t Value,
654  uint32_t Type, int64_t Addend) {
655  uint8_t *LocalAddress = Section.getAddressWithOffset(Offset);
656  switch (Type) {
657  default:
658  llvm_unreachable("Relocation type not implemented yet!");
659  break;
660  case ELF::R_PPC_ADDR16_LO:
661  writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
662  break;
663  case ELF::R_PPC_ADDR16_HI:
664  writeInt16BE(LocalAddress, applyPPChi(Value + Addend));
665  break;
666  case ELF::R_PPC_ADDR16_HA:
667  writeInt16BE(LocalAddress, applyPPCha(Value + Addend));
668  break;
669  }
670 }
671 
672 void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section,
673  uint64_t Offset, uint64_t Value,
674  uint32_t Type, int64_t Addend) {
675  uint8_t *LocalAddress = Section.getAddressWithOffset(Offset);
676  switch (Type) {
677  default:
678  llvm_unreachable("Relocation type not implemented yet!");
679  break;
680  case ELF::R_PPC64_ADDR16:
681  writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
682  break;
683  case ELF::R_PPC64_ADDR16_DS:
684  writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
685  break;
686  case ELF::R_PPC64_ADDR16_LO:
687  writeInt16BE(LocalAddress, applyPPClo(Value + Addend));
688  break;
689  case ELF::R_PPC64_ADDR16_LO_DS:
690  writeInt16BE(LocalAddress, applyPPClo(Value + Addend) & ~3);
691  break;
692  case ELF::R_PPC64_ADDR16_HI:
693  writeInt16BE(LocalAddress, applyPPChi(Value + Addend));
694  break;
695  case ELF::R_PPC64_ADDR16_HA:
696  writeInt16BE(LocalAddress, applyPPCha(Value + Addend));
697  break;
698  case ELF::R_PPC64_ADDR16_HIGHER:
699  writeInt16BE(LocalAddress, applyPPChigher(Value + Addend));
700  break;
701  case ELF::R_PPC64_ADDR16_HIGHERA:
702  writeInt16BE(LocalAddress, applyPPChighera(Value + Addend));
703  break;
704  case ELF::R_PPC64_ADDR16_HIGHEST:
705  writeInt16BE(LocalAddress, applyPPChighest(Value + Addend));
706  break;
707  case ELF::R_PPC64_ADDR16_HIGHESTA:
708  writeInt16BE(LocalAddress, applyPPChighesta(Value + Addend));
709  break;
710  case ELF::R_PPC64_ADDR14: {
711  assert(((Value + Addend) & 3) == 0);
712  // Preserve the AA/LK bits in the branch instruction
713  uint8_t aalk = *(LocalAddress + 3);
714  writeInt16BE(LocalAddress + 2, (aalk & 3) | ((Value + Addend) & 0xfffc));
715  } break;
716  case ELF::R_PPC64_REL16_LO: {
717  uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
718  uint64_t Delta = Value - FinalAddress + Addend;
719  writeInt16BE(LocalAddress, applyPPClo(Delta));
720  } break;
721  case ELF::R_PPC64_REL16_HI: {
722  uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
723  uint64_t Delta = Value - FinalAddress + Addend;
724  writeInt16BE(LocalAddress, applyPPChi(Delta));
725  } break;
726  case ELF::R_PPC64_REL16_HA: {
727  uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
728  uint64_t Delta = Value - FinalAddress + Addend;
729  writeInt16BE(LocalAddress, applyPPCha(Delta));
730  } break;
731  case ELF::R_PPC64_ADDR32: {
732  int32_t Result = static_cast<int32_t>(Value + Addend);
733  if (SignExtend32<32>(Result) != Result)
734  llvm_unreachable("Relocation R_PPC64_ADDR32 overflow");
735  writeInt32BE(LocalAddress, Result);
736  } break;
737  case ELF::R_PPC64_REL24: {
738  uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
739  int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
740  if (SignExtend32<26>(delta) != delta)
741  llvm_unreachable("Relocation R_PPC64_REL24 overflow");
742  // Generates a 'bl <address>' instruction
743  writeInt32BE(LocalAddress, 0x48000001 | (delta & 0x03FFFFFC));
744  } break;
745  case ELF::R_PPC64_REL32: {
746  uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
747  int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
748  if (SignExtend32<32>(delta) != delta)
749  llvm_unreachable("Relocation R_PPC64_REL32 overflow");
750  writeInt32BE(LocalAddress, delta);
751  } break;
752  case ELF::R_PPC64_REL64: {
753  uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
754  uint64_t Delta = Value - FinalAddress + Addend;
755  writeInt64BE(LocalAddress, Delta);
756  } break;
757  case ELF::R_PPC64_ADDR64:
758  writeInt64BE(LocalAddress, Value + Addend);
759  break;
760  }
761 }
762 
763 void RuntimeDyldELF::resolveSystemZRelocation(const SectionEntry &Section,
764  uint64_t Offset, uint64_t Value,
765  uint32_t Type, int64_t Addend) {
766  uint8_t *LocalAddress = Section.getAddressWithOffset(Offset);
767  switch (Type) {
768  default:
769  llvm_unreachable("Relocation type not implemented yet!");
770  break;
771  case ELF::R_390_PC16DBL:
772  case ELF::R_390_PLT16DBL: {
773  int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset);
774  assert(int16_t(Delta / 2) * 2 == Delta && "R_390_PC16DBL overflow");
775  writeInt16BE(LocalAddress, Delta / 2);
776  break;
777  }
778  case ELF::R_390_PC32DBL:
779  case ELF::R_390_PLT32DBL: {
780  int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset);
781  assert(int32_t(Delta / 2) * 2 == Delta && "R_390_PC32DBL overflow");
782  writeInt32BE(LocalAddress, Delta / 2);
783  break;
784  }
785  case ELF::R_390_PC32: {
786  int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset);
787  assert(int32_t(Delta) == Delta && "R_390_PC32 overflow");
788  writeInt32BE(LocalAddress, Delta);
789  break;
790  }
791  case ELF::R_390_64:
792  writeInt64BE(LocalAddress, Value + Addend);
793  break;
794  case ELF::R_390_PC64: {
795  int64_t Delta = (Value + Addend) - Section.getLoadAddressWithOffset(Offset);
796  writeInt64BE(LocalAddress, Delta);
797  break;
798  }
799  }
800 }
801 
802 // The target location for the relocation is described by RE.SectionID and
803 // RE.Offset. RE.SectionID can be used to find the SectionEntry. Each
804 // SectionEntry has three members describing its location.
805 // SectionEntry::Address is the address at which the section has been loaded
806 // into memory in the current (host) process. SectionEntry::LoadAddress is the
807 // address that the section will have in the target process.
808 // SectionEntry::ObjAddress is the address of the bits for this section in the
809 // original emitted object image (also in the current address space).
810 //
811 // Relocations will be applied as if the section were loaded at
812 // SectionEntry::LoadAddress, but they will be applied at an address based
813 // on SectionEntry::Address. SectionEntry::ObjAddress will be used to refer to
814 // Target memory contents if they are required for value calculations.
815 //
816 // The Value parameter here is the load address of the symbol for the
817 // relocation to be applied. For relocations which refer to symbols in the
818 // current object Value will be the LoadAddress of the section in which
819 // the symbol resides (RE.Addend provides additional information about the
820 // symbol location). For external symbols, Value will be the address of the
821 // symbol in the target address space.
822 void RuntimeDyldELF::resolveRelocation(const RelocationEntry &RE,
823  uint64_t Value) {
824  const SectionEntry &Section = Sections[RE.SectionID];
825  return resolveRelocation(Section, RE.Offset, Value, RE.RelType, RE.Addend,
826  RE.SymOffset, RE.SectionID);
827 }
828 
829 void RuntimeDyldELF::resolveRelocation(const SectionEntry &Section,
830  uint64_t Offset, uint64_t Value,
831  uint32_t Type, int64_t Addend,
832  uint64_t SymOffset, SID SectionID) {
833  switch (Arch) {
834  case Triple::x86_64:
835  resolveX86_64Relocation(Section, Offset, Value, Type, Addend, SymOffset);
836  break;
837  case Triple::x86:
838  resolveX86Relocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
839  (uint32_t)(Addend & 0xffffffffL));
840  break;
841  case Triple::aarch64:
842  case Triple::aarch64_be:
843  resolveAArch64Relocation(Section, Offset, Value, Type, Addend);
844  break;
845  case Triple::arm: // Fall through.
846  case Triple::armeb:
847  case Triple::thumb:
848  case Triple::thumbeb:
849  resolveARMRelocation(Section, Offset, (uint32_t)(Value & 0xffffffffL), Type,
850  (uint32_t)(Addend & 0xffffffffL));
851  break;
852  case Triple::ppc:
853  resolvePPC32Relocation(Section, Offset, Value, Type, Addend);
854  break;
855  case Triple::ppc64: // Fall through.
856  case Triple::ppc64le:
857  resolvePPC64Relocation(Section, Offset, Value, Type, Addend);
858  break;
859  case Triple::systemz:
860  resolveSystemZRelocation(Section, Offset, Value, Type, Addend);
861  break;
862  default:
863  llvm_unreachable("Unsupported CPU type!");
864  }
865 }
866 
867 void *RuntimeDyldELF::computePlaceholderAddress(unsigned SectionID, uint64_t Offset) const {
868  return (void *)(Sections[SectionID].getObjAddress() + Offset);
869 }
870 
871 void RuntimeDyldELF::processSimpleRelocation(unsigned SectionID, uint64_t Offset, unsigned RelType, RelocationValueRef Value) {
872  RelocationEntry RE(SectionID, Offset, RelType, Value.Addend, Value.Offset);
873  if (Value.SymbolName)
875  else
877 }
878 
879 uint32_t RuntimeDyldELF::getMatchingLoRelocation(uint32_t RelType,
880  bool IsLocal) const {
881  switch (RelType) {
882  case ELF::R_MICROMIPS_GOT16:
883  if (IsLocal)
884  return ELF::R_MICROMIPS_LO16;
885  break;
886  case ELF::R_MICROMIPS_HI16:
887  return ELF::R_MICROMIPS_LO16;
888  case ELF::R_MIPS_GOT16:
889  if (IsLocal)
890  return ELF::R_MIPS_LO16;
891  break;
892  case ELF::R_MIPS_HI16:
893  return ELF::R_MIPS_LO16;
894  case ELF::R_MIPS_PCHI16:
895  return ELF::R_MIPS_PCLO16;
896  default:
897  break;
898  }
899  return ELF::R_MIPS_NONE;
900 }
901 
902 // Sometimes we don't need to create thunk for a branch.
903 // This typically happens when branch target is located
904 // in the same object file. In such case target is either
905 // a weak symbol or symbol in a different executable section.
906 // This function checks if branch target is located in the
907 // same object file and if distance between source and target
908 // fits R_AARCH64_CALL26 relocation. If both conditions are
909 // met, it emits direct jump to the target and returns true.
910 // Otherwise false is returned and thunk is created.
911 bool RuntimeDyldELF::resolveAArch64ShortBranch(
912  unsigned SectionID, relocation_iterator RelI,
913  const RelocationValueRef &Value) {
914  uint64_t Address;
915  if (Value.SymbolName) {
916  auto Loc = GlobalSymbolTable.find(Value.SymbolName);
917 
918  // Don't create direct branch for external symbols.
919  if (Loc == GlobalSymbolTable.end())
920  return false;
921 
922  const auto &SymInfo = Loc->second;
923  Address =
924  uint64_t(Sections[SymInfo.getSectionID()].getLoadAddressWithOffset(
925  SymInfo.getOffset()));
926  } else {
927  Address = uint64_t(Sections[Value.SectionID].getLoadAddress());
928  }
929  uint64_t Offset = RelI->getOffset();
930  uint64_t SourceAddress = Sections[SectionID].getLoadAddressWithOffset(Offset);
931 
932  // R_AARCH64_CALL26 requires immediate to be in range -2^27 <= imm < 2^27
933  // If distance between source and target is out of range then we should
934  // create thunk.
935  if (!isInt<28>(Address + Value.Addend - SourceAddress))
936  return false;
937 
938  resolveRelocation(Sections[SectionID], Offset, Address, RelI->getType(),
939  Value.Addend);
940 
941  return true;
942 }
943 
946  unsigned SectionID, relocation_iterator RelI, const ObjectFile &O,
947  ObjSectionToIDMap &ObjSectionToID, StubMap &Stubs) {
948  const auto &Obj = cast<ELFObjectFileBase>(O);
949  uint64_t RelType = RelI->getType();
950  ErrorOr<int64_t> AddendOrErr = ELFRelocationRef(*RelI).getAddend();
951  int64_t Addend = AddendOrErr ? *AddendOrErr : 0;
952  elf_symbol_iterator Symbol = RelI->getSymbol();
953 
954  // Obtain the symbol name which is referenced in the relocation
955  StringRef TargetName;
956  if (Symbol != Obj.symbol_end()) {
957  if (auto TargetNameOrErr = Symbol->getName())
958  TargetName = *TargetNameOrErr;
959  else
960  return TargetNameOrErr.takeError();
961  }
962  DEBUG(dbgs() << "\t\tRelType: " << RelType << " Addend: " << Addend
963  << " TargetName: " << TargetName << "\n");
964  RelocationValueRef Value;
965  // First search for the symbol in the local symbol table
967 
968  // Search for the symbol in the global symbol table
970  if (Symbol != Obj.symbol_end()) {
971  gsi = GlobalSymbolTable.find(TargetName.data());
972  Expected<SymbolRef::Type> SymTypeOrErr = Symbol->getType();
973  if (!SymTypeOrErr) {
974  std::string Buf;
975  raw_string_ostream OS(Buf);
976  logAllUnhandledErrors(SymTypeOrErr.takeError(), OS, "");
977  OS.flush();
978  report_fatal_error(Buf);
979  }
980  SymType = *SymTypeOrErr;
981  }
982  if (gsi != GlobalSymbolTable.end()) {
983  const auto &SymInfo = gsi->second;
984  Value.SectionID = SymInfo.getSectionID();
985  Value.Offset = SymInfo.getOffset();
986  Value.Addend = SymInfo.getOffset() + Addend;
987  } else {
988  switch (SymType) {
989  case SymbolRef::ST_Debug: {
990  // TODO: Now ELF SymbolRef::ST_Debug = STT_SECTION, it's not obviously
991  // and can be changed by another developers. Maybe best way is add
992  // a new symbol type ST_Section to SymbolRef and use it.
993  auto SectionOrErr = Symbol->getSection();
994  if (!SectionOrErr) {
995  std::string Buf;
996  raw_string_ostream OS(Buf);
997  logAllUnhandledErrors(SectionOrErr.takeError(), OS, "");
998  OS.flush();
999  report_fatal_error(Buf);
1000  }
1001  section_iterator si = *SectionOrErr;
1002  if (si == Obj.section_end())
1003  llvm_unreachable("Symbol section not found, bad object file format!");
1004  DEBUG(dbgs() << "\t\tThis is section symbol\n");
1005  bool isCode = si->isText();
1006  if (auto SectionIDOrErr = findOrEmitSection(Obj, (*si), isCode,
1007  ObjSectionToID))
1008  Value.SectionID = *SectionIDOrErr;
1009  else
1010  return SectionIDOrErr.takeError();
1011  Value.Addend = Addend;
1012  break;
1013  }
1014  case SymbolRef::ST_Data:
1016  case SymbolRef::ST_Unknown: {
1017  Value.SymbolName = TargetName.data();
1018  Value.Addend = Addend;
1019 
1020  // Absolute relocations will have a zero symbol ID (STN_UNDEF), which
1021  // will manifest here as a NULL symbol name.
1022  // We can set this as a valid (but empty) symbol name, and rely
1023  // on addRelocationForSymbol to handle this.
1024  if (!Value.SymbolName)
1025  Value.SymbolName = "";
1026  break;
1027  }
1028  default:
1029  llvm_unreachable("Unresolved symbol type!");
1030  break;
1031  }
1032  }
1033 
1034  uint64_t Offset = RelI->getOffset();
1035 
1036  DEBUG(dbgs() << "\t\tSectionID: " << SectionID << " Offset: " << Offset
1037  << "\n");
1038  if ((Arch == Triple::aarch64 || Arch == Triple::aarch64_be) &&
1039  (RelType == ELF::R_AARCH64_CALL26 || RelType == ELF::R_AARCH64_JUMP26)) {
1040  // This is an AArch64 branch relocation, need to use a stub function.
1041  DEBUG(dbgs() << "\t\tThis is an AArch64 branch relocation.");
1042  SectionEntry &Section = Sections[SectionID];
1043 
1044  // Look for an existing stub.
1045  StubMap::const_iterator i = Stubs.find(Value);
1046  if (i != Stubs.end()) {
1047  resolveRelocation(Section, Offset,
1048  (uint64_t)Section.getAddressWithOffset(i->second),
1049  RelType, 0);
1050  DEBUG(dbgs() << " Stub function found\n");
1051  } else if (!resolveAArch64ShortBranch(SectionID, RelI, Value)) {
1052  // Create a new stub function.
1053  DEBUG(dbgs() << " Create a new stub function\n");
1054  Stubs[Value] = Section.getStubOffset();
1055  uint8_t *StubTargetAddr = createStubFunction(
1056  Section.getAddressWithOffset(Section.getStubOffset()));
1057 
1058  RelocationEntry REmovz_g3(SectionID,
1059  StubTargetAddr - Section.getAddress(),
1060  ELF::R_AARCH64_MOVW_UABS_G3, Value.Addend);
1061  RelocationEntry REmovk_g2(SectionID, StubTargetAddr -
1062  Section.getAddress() + 4,
1063  ELF::R_AARCH64_MOVW_UABS_G2_NC, Value.Addend);
1064  RelocationEntry REmovk_g1(SectionID, StubTargetAddr -
1065  Section.getAddress() + 8,
1066  ELF::R_AARCH64_MOVW_UABS_G1_NC, Value.Addend);
1067  RelocationEntry REmovk_g0(SectionID, StubTargetAddr -
1068  Section.getAddress() + 12,
1069  ELF::R_AARCH64_MOVW_UABS_G0_NC, Value.Addend);
1070 
1071  if (Value.SymbolName) {
1072  addRelocationForSymbol(REmovz_g3, Value.SymbolName);
1073  addRelocationForSymbol(REmovk_g2, Value.SymbolName);
1074  addRelocationForSymbol(REmovk_g1, Value.SymbolName);
1075  addRelocationForSymbol(REmovk_g0, Value.SymbolName);
1076  } else {
1077  addRelocationForSection(REmovz_g3, Value.SectionID);
1078  addRelocationForSection(REmovk_g2, Value.SectionID);
1079  addRelocationForSection(REmovk_g1, Value.SectionID);
1080  addRelocationForSection(REmovk_g0, Value.SectionID);
1081  }
1082  resolveRelocation(Section, Offset,
1083  reinterpret_cast<uint64_t>(Section.getAddressWithOffset(
1084  Section.getStubOffset())),
1085  RelType, 0);
1086  Section.advanceStubOffset(getMaxStubSize());
1087  }
1088  } else if (Arch == Triple::arm) {
1089  if (RelType == ELF::R_ARM_PC24 || RelType == ELF::R_ARM_CALL ||
1090  RelType == ELF::R_ARM_JUMP24) {
1091  // This is an ARM branch relocation, need to use a stub function.
1092  DEBUG(dbgs() << "\t\tThis is an ARM branch relocation.\n");
1093  SectionEntry &Section = Sections[SectionID];
1094 
1095  // Look for an existing stub.
1096  StubMap::const_iterator i = Stubs.find(Value);
1097  if (i != Stubs.end()) {
1098  resolveRelocation(
1099  Section, Offset,
1100  reinterpret_cast<uint64_t>(Section.getAddressWithOffset(i->second)),
1101  RelType, 0);
1102  DEBUG(dbgs() << " Stub function found\n");
1103  } else {
1104  // Create a new stub function.
1105  DEBUG(dbgs() << " Create a new stub function\n");
1106  Stubs[Value] = Section.getStubOffset();
1107  uint8_t *StubTargetAddr = createStubFunction(
1108  Section.getAddressWithOffset(Section.getStubOffset()));
1109  RelocationEntry RE(SectionID, StubTargetAddr - Section.getAddress(),
1110  ELF::R_ARM_ABS32, Value.Addend);
1111  if (Value.SymbolName)
1113  else
1115 
1116  resolveRelocation(Section, Offset, reinterpret_cast<uint64_t>(
1117  Section.getAddressWithOffset(
1118  Section.getStubOffset())),
1119  RelType, 0);
1120  Section.advanceStubOffset(getMaxStubSize());
1121  }
1122  } else {
1123  uint32_t *Placeholder =
1124  reinterpret_cast<uint32_t*>(computePlaceholderAddress(SectionID, Offset));
1125  if (RelType == ELF::R_ARM_PREL31 || RelType == ELF::R_ARM_TARGET1 ||
1126  RelType == ELF::R_ARM_ABS32) {
1127  Value.Addend += *Placeholder;
1128  } else if (RelType == ELF::R_ARM_MOVW_ABS_NC || RelType == ELF::R_ARM_MOVT_ABS) {
1129  // See ELF for ARM documentation
1130  Value.Addend += (int16_t)((*Placeholder & 0xFFF) | (((*Placeholder >> 16) & 0xF) << 12));
1131  }
1132  processSimpleRelocation(SectionID, Offset, RelType, Value);
1133  }
1134  } else if (IsMipsO32ABI) {
1135  uint8_t *Placeholder = reinterpret_cast<uint8_t *>(
1136  computePlaceholderAddress(SectionID, Offset));
1137  uint32_t Opcode = readBytesUnaligned(Placeholder, 4);
1138  if (RelType == ELF::R_MIPS_26) {
1139  // This is an Mips branch relocation, need to use a stub function.
1140  DEBUG(dbgs() << "\t\tThis is a Mips branch relocation.");
1141  SectionEntry &Section = Sections[SectionID];
1142 
1143  // Extract the addend from the instruction.
1144  // We shift up by two since the Value will be down shifted again
1145  // when applying the relocation.
1146  uint32_t Addend = (Opcode & 0x03ffffff) << 2;
1147 
1148  Value.Addend += Addend;
1149 
1150  // Look up for existing stub.
1151  StubMap::const_iterator i = Stubs.find(Value);
1152  if (i != Stubs.end()) {
1153  RelocationEntry RE(SectionID, Offset, RelType, i->second);
1154  addRelocationForSection(RE, SectionID);
1155  DEBUG(dbgs() << " Stub function found\n");
1156  } else {
1157  // Create a new stub function.
1158  DEBUG(dbgs() << " Create a new stub function\n");
1159  Stubs[Value] = Section.getStubOffset();
1160 
1161  unsigned AbiVariant;
1162  O.getPlatformFlags(AbiVariant);
1163 
1164  uint8_t *StubTargetAddr = createStubFunction(
1165  Section.getAddressWithOffset(Section.getStubOffset()), AbiVariant);
1166 
1167  // Creating Hi and Lo relocations for the filled stub instructions.
1168  RelocationEntry REHi(SectionID, StubTargetAddr - Section.getAddress(),
1169  ELF::R_MIPS_HI16, Value.Addend);
1170  RelocationEntry RELo(SectionID,
1171  StubTargetAddr - Section.getAddress() + 4,
1172  ELF::R_MIPS_LO16, Value.Addend);
1173 
1174  if (Value.SymbolName) {
1175  addRelocationForSymbol(REHi, Value.SymbolName);
1176  addRelocationForSymbol(RELo, Value.SymbolName);
1177  }
1178  else {
1179  addRelocationForSection(REHi, Value.SectionID);
1180  addRelocationForSection(RELo, Value.SectionID);
1181  }
1182 
1183  RelocationEntry RE(SectionID, Offset, RelType, Section.getStubOffset());
1184  addRelocationForSection(RE, SectionID);
1185  Section.advanceStubOffset(getMaxStubSize());
1186  }
1187  } else if (RelType == ELF::R_MIPS_HI16 || RelType == ELF::R_MIPS_PCHI16) {
1188  int64_t Addend = (Opcode & 0x0000ffff) << 16;
1189  RelocationEntry RE(SectionID, Offset, RelType, Addend);
1190  PendingRelocs.push_back(std::make_pair(Value, RE));
1191  } else if (RelType == ELF::R_MIPS_LO16 || RelType == ELF::R_MIPS_PCLO16) {
1192  int64_t Addend = Value.Addend + SignExtend32<16>(Opcode & 0x0000ffff);
1193  for (auto I = PendingRelocs.begin(); I != PendingRelocs.end();) {
1194  const RelocationValueRef &MatchingValue = I->first;
1195  RelocationEntry &Reloc = I->second;
1196  if (MatchingValue == Value &&
1197  RelType == getMatchingLoRelocation(Reloc.RelType) &&
1198  SectionID == Reloc.SectionID) {
1199  Reloc.Addend += Addend;
1200  if (Value.SymbolName)
1201  addRelocationForSymbol(Reloc, Value.SymbolName);
1202  else
1203  addRelocationForSection(Reloc, Value.SectionID);
1204  I = PendingRelocs.erase(I);
1205  } else
1206  ++I;
1207  }
1208  RelocationEntry RE(SectionID, Offset, RelType, Addend);
1209  if (Value.SymbolName)
1211  else
1213  } else {
1214  if (RelType == ELF::R_MIPS_32)
1215  Value.Addend += Opcode;
1216  else if (RelType == ELF::R_MIPS_PC16)
1217  Value.Addend += SignExtend32<18>((Opcode & 0x0000ffff) << 2);
1218  else if (RelType == ELF::R_MIPS_PC19_S2)
1219  Value.Addend += SignExtend32<21>((Opcode & 0x0007ffff) << 2);
1220  else if (RelType == ELF::R_MIPS_PC21_S2)
1221  Value.Addend += SignExtend32<23>((Opcode & 0x001fffff) << 2);
1222  else if (RelType == ELF::R_MIPS_PC26_S2)
1223  Value.Addend += SignExtend32<28>((Opcode & 0x03ffffff) << 2);
1224  processSimpleRelocation(SectionID, Offset, RelType, Value);
1225  }
1226  } else if (IsMipsN32ABI || IsMipsN64ABI) {
1227  uint32_t r_type = RelType & 0xff;
1228  RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1229  if (r_type == ELF::R_MIPS_CALL16 || r_type == ELF::R_MIPS_GOT_PAGE
1230  || r_type == ELF::R_MIPS_GOT_DISP) {
1231  StringMap<uint64_t>::iterator i = GOTSymbolOffsets.find(TargetName);
1232  if (i != GOTSymbolOffsets.end())
1233  RE.SymOffset = i->second;
1234  else {
1235  RE.SymOffset = allocateGOTEntries(SectionID, 1);
1236  GOTSymbolOffsets[TargetName] = RE.SymOffset;
1237  }
1238  }
1239  if (Value.SymbolName)
1241  else
1243  } else if (Arch == Triple::ppc64 || Arch == Triple::ppc64le) {
1244  if (RelType == ELF::R_PPC64_REL24) {
1245  // Determine ABI variant in use for this object.
1246  unsigned AbiVariant;
1247  Obj.getPlatformFlags(AbiVariant);
1248  AbiVariant &= ELF::EF_PPC64_ABI;
1249  // A PPC branch relocation will need a stub function if the target is
1250  // an external symbol (Symbol::ST_Unknown) or if the target address
1251  // is not within the signed 24-bits branch address.
1252  SectionEntry &Section = Sections[SectionID];
1253  uint8_t *Target = Section.getAddressWithOffset(Offset);
1254  bool RangeOverflow = false;
1255  if (SymType != SymbolRef::ST_Unknown) {
1256  if (AbiVariant != 2) {
1257  // In the ELFv1 ABI, a function call may point to the .opd entry,
1258  // so the final symbol value is calculated based on the relocation
1259  // values in the .opd section.
1260  if (auto Err = findOPDEntrySection(Obj, ObjSectionToID, Value))
1261  return std::move(Err);
1262  } else {
1263  // In the ELFv2 ABI, a function symbol may provide a local entry
1264  // point, which must be used for direct calls.
1265  uint8_t SymOther = Symbol->getOther();
1266  Value.Addend += ELF::decodePPC64LocalEntryOffset(SymOther);
1267  }
1268  uint8_t *RelocTarget =
1269  Sections[Value.SectionID].getAddressWithOffset(Value.Addend);
1270  int32_t delta = static_cast<int32_t>(Target - RelocTarget);
1271  // If it is within 26-bits branch range, just set the branch target
1272  if (SignExtend32<26>(delta) == delta) {
1273  RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1274  if (Value.SymbolName)
1275  addRelocationForSymbol(RE, Value.SymbolName);
1276  else
1277  addRelocationForSection(RE, Value.SectionID);
1278  } else {
1279  RangeOverflow = true;
1280  }
1281  }
1282  if (SymType == SymbolRef::ST_Unknown || RangeOverflow) {
1283  // It is an external symbol (SymbolRef::ST_Unknown) or within a range
1284  // larger than 24-bits.
1285  StubMap::const_iterator i = Stubs.find(Value);
1286  if (i != Stubs.end()) {
1287  // Symbol function stub already created, just relocate to it
1288  resolveRelocation(Section, Offset,
1289  reinterpret_cast<uint64_t>(
1290  Section.getAddressWithOffset(i->second)),
1291  RelType, 0);
1292  DEBUG(dbgs() << " Stub function found\n");
1293  } else {
1294  // Create a new stub function.
1295  DEBUG(dbgs() << " Create a new stub function\n");
1296  Stubs[Value] = Section.getStubOffset();
1297  uint8_t *StubTargetAddr = createStubFunction(
1298  Section.getAddressWithOffset(Section.getStubOffset()),
1299  AbiVariant);
1300  RelocationEntry RE(SectionID, StubTargetAddr - Section.getAddress(),
1301  ELF::R_PPC64_ADDR64, Value.Addend);
1302 
1303  // Generates the 64-bits address loads as exemplified in section
1304  // 4.5.1 in PPC64 ELF ABI. Note that the relocations need to
1305  // apply to the low part of the instructions, so we have to update
1306  // the offset according to the target endianness.
1307  uint64_t StubRelocOffset = StubTargetAddr - Section.getAddress();
1308  if (!IsTargetLittleEndian)
1309  StubRelocOffset += 2;
1310 
1311  RelocationEntry REhst(SectionID, StubRelocOffset + 0,
1312  ELF::R_PPC64_ADDR16_HIGHEST, Value.Addend);
1313  RelocationEntry REhr(SectionID, StubRelocOffset + 4,
1314  ELF::R_PPC64_ADDR16_HIGHER, Value.Addend);
1315  RelocationEntry REh(SectionID, StubRelocOffset + 12,
1316  ELF::R_PPC64_ADDR16_HI, Value.Addend);
1317  RelocationEntry REl(SectionID, StubRelocOffset + 16,
1318  ELF::R_PPC64_ADDR16_LO, Value.Addend);
1319 
1320  if (Value.SymbolName) {
1321  addRelocationForSymbol(REhst, Value.SymbolName);
1322  addRelocationForSymbol(REhr, Value.SymbolName);
1323  addRelocationForSymbol(REh, Value.SymbolName);
1324  addRelocationForSymbol(REl, Value.SymbolName);
1325  } else {
1326  addRelocationForSection(REhst, Value.SectionID);
1327  addRelocationForSection(REhr, Value.SectionID);
1328  addRelocationForSection(REh, Value.SectionID);
1329  addRelocationForSection(REl, Value.SectionID);
1330  }
1331 
1332  resolveRelocation(Section, Offset, reinterpret_cast<uint64_t>(
1333  Section.getAddressWithOffset(
1334  Section.getStubOffset())),
1335  RelType, 0);
1336  Section.advanceStubOffset(getMaxStubSize());
1337  }
1338  if (SymType == SymbolRef::ST_Unknown) {
1339  // Restore the TOC for external calls
1340  if (AbiVariant == 2)
1341  writeInt32BE(Target + 4, 0xE8410018); // ld r2,28(r1)
1342  else
1343  writeInt32BE(Target + 4, 0xE8410028); // ld r2,40(r1)
1344  }
1345  }
1346  } else if (RelType == ELF::R_PPC64_TOC16 ||
1347  RelType == ELF::R_PPC64_TOC16_DS ||
1348  RelType == ELF::R_PPC64_TOC16_LO ||
1349  RelType == ELF::R_PPC64_TOC16_LO_DS ||
1350  RelType == ELF::R_PPC64_TOC16_HI ||
1351  RelType == ELF::R_PPC64_TOC16_HA) {
1352  // These relocations are supposed to subtract the TOC address from
1353  // the final value. This does not fit cleanly into the RuntimeDyld
1354  // scheme, since there may be *two* sections involved in determining
1355  // the relocation value (the section of the symbol referred to by the
1356  // relocation, and the TOC section associated with the current module).
1357  //
1358  // Fortunately, these relocations are currently only ever generated
1359  // referring to symbols that themselves reside in the TOC, which means
1360  // that the two sections are actually the same. Thus they cancel out
1361  // and we can immediately resolve the relocation right now.
1362  switch (RelType) {
1363  case ELF::R_PPC64_TOC16: RelType = ELF::R_PPC64_ADDR16; break;
1364  case ELF::R_PPC64_TOC16_DS: RelType = ELF::R_PPC64_ADDR16_DS; break;
1365  case ELF::R_PPC64_TOC16_LO: RelType = ELF::R_PPC64_ADDR16_LO; break;
1366  case ELF::R_PPC64_TOC16_LO_DS: RelType = ELF::R_PPC64_ADDR16_LO_DS; break;
1367  case ELF::R_PPC64_TOC16_HI: RelType = ELF::R_PPC64_ADDR16_HI; break;
1368  case ELF::R_PPC64_TOC16_HA: RelType = ELF::R_PPC64_ADDR16_HA; break;
1369  default: llvm_unreachable("Wrong relocation type.");
1370  }
1371 
1372  RelocationValueRef TOCValue;
1373  if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, TOCValue))
1374  return std::move(Err);
1375  if (Value.SymbolName || Value.SectionID != TOCValue.SectionID)
1376  llvm_unreachable("Unsupported TOC relocation.");
1377  Value.Addend -= TOCValue.Addend;
1378  resolveRelocation(Sections[SectionID], Offset, Value.Addend, RelType, 0);
1379  } else {
1380  // There are two ways to refer to the TOC address directly: either
1381  // via a ELF::R_PPC64_TOC relocation (where both symbol and addend are
1382  // ignored), or via any relocation that refers to the magic ".TOC."
1383  // symbols (in which case the addend is respected).
1384  if (RelType == ELF::R_PPC64_TOC) {
1385  RelType = ELF::R_PPC64_ADDR64;
1386  if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, Value))
1387  return std::move(Err);
1388  } else if (TargetName == ".TOC.") {
1389  if (auto Err = findPPC64TOCSection(Obj, ObjSectionToID, Value))
1390  return std::move(Err);
1391  Value.Addend += Addend;
1392  }
1393 
1394  RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
1395 
1396  if (Value.SymbolName)
1397  addRelocationForSymbol(RE, Value.SymbolName);
1398  else
1399  addRelocationForSection(RE, Value.SectionID);
1400  }
1401  } else if (Arch == Triple::systemz &&
1402  (RelType == ELF::R_390_PLT32DBL || RelType == ELF::R_390_GOTENT)) {
1403  // Create function stubs for both PLT and GOT references, regardless of
1404  // whether the GOT reference is to data or code. The stub contains the
1405  // full address of the symbol, as needed by GOT references, and the
1406  // executable part only adds an overhead of 8 bytes.
1407  //
1408  // We could try to conserve space by allocating the code and data
1409  // parts of the stub separately. However, as things stand, we allocate
1410  // a stub for every relocation, so using a GOT in JIT code should be
1411  // no less space efficient than using an explicit constant pool.
1412  DEBUG(dbgs() << "\t\tThis is a SystemZ indirect relocation.");
1413  SectionEntry &Section = Sections[SectionID];
1414 
1415  // Look for an existing stub.
1416  StubMap::const_iterator i = Stubs.find(Value);
1417  uintptr_t StubAddress;
1418  if (i != Stubs.end()) {
1419  StubAddress = uintptr_t(Section.getAddressWithOffset(i->second));
1420  DEBUG(dbgs() << " Stub function found\n");
1421  } else {
1422  // Create a new stub function.
1423  DEBUG(dbgs() << " Create a new stub function\n");
1424 
1425  uintptr_t BaseAddress = uintptr_t(Section.getAddress());
1426  uintptr_t StubAlignment = getStubAlignment();
1427  StubAddress =
1428  (BaseAddress + Section.getStubOffset() + StubAlignment - 1) &
1429  -StubAlignment;
1430  unsigned StubOffset = StubAddress - BaseAddress;
1431 
1432  Stubs[Value] = StubOffset;
1433  createStubFunction((uint8_t *)StubAddress);
1434  RelocationEntry RE(SectionID, StubOffset + 8, ELF::R_390_64,
1435  Value.Offset);
1436  if (Value.SymbolName)
1437  addRelocationForSymbol(RE, Value.SymbolName);
1438  else
1439  addRelocationForSection(RE, Value.SectionID);
1440  Section.advanceStubOffset(getMaxStubSize());
1441  }
1442 
1443  if (RelType == ELF::R_390_GOTENT)
1444  resolveRelocation(Section, Offset, StubAddress + 8, ELF::R_390_PC32DBL,
1445  Addend);
1446  else
1447  resolveRelocation(Section, Offset, StubAddress, RelType, Addend);
1448  } else if (Arch == Triple::x86_64) {
1449  if (RelType == ELF::R_X86_64_PLT32) {
1450  // The way the PLT relocations normally work is that the linker allocates
1451  // the
1452  // PLT and this relocation makes a PC-relative call into the PLT. The PLT
1453  // entry will then jump to an address provided by the GOT. On first call,
1454  // the
1455  // GOT address will point back into PLT code that resolves the symbol. After
1456  // the first call, the GOT entry points to the actual function.
1457  //
1458  // For local functions we're ignoring all of that here and just replacing
1459  // the PLT32 relocation type with PC32, which will translate the relocation
1460  // into a PC-relative call directly to the function. For external symbols we
1461  // can't be sure the function will be within 2^32 bytes of the call site, so
1462  // we need to create a stub, which calls into the GOT. This case is
1463  // equivalent to the usual PLT implementation except that we use the stub
1464  // mechanism in RuntimeDyld (which puts stubs at the end of the section)
1465  // rather than allocating a PLT section.
1466  if (Value.SymbolName) {
1467  // This is a call to an external function.
1468  // Look for an existing stub.
1469  SectionEntry &Section = Sections[SectionID];
1470  StubMap::const_iterator i = Stubs.find(Value);
1471  uintptr_t StubAddress;
1472  if (i != Stubs.end()) {
1473  StubAddress = uintptr_t(Section.getAddress()) + i->second;
1474  DEBUG(dbgs() << " Stub function found\n");
1475  } else {
1476  // Create a new stub function (equivalent to a PLT entry).
1477  DEBUG(dbgs() << " Create a new stub function\n");
1478 
1479  uintptr_t BaseAddress = uintptr_t(Section.getAddress());
1480  uintptr_t StubAlignment = getStubAlignment();
1481  StubAddress =
1482  (BaseAddress + Section.getStubOffset() + StubAlignment - 1) &
1483  -StubAlignment;
1484  unsigned StubOffset = StubAddress - BaseAddress;
1485  Stubs[Value] = StubOffset;
1486  createStubFunction((uint8_t *)StubAddress);
1487 
1488  // Bump our stub offset counter
1489  Section.advanceStubOffset(getMaxStubSize());
1490 
1491  // Allocate a GOT Entry
1492  uint64_t GOTOffset = allocateGOTEntries(SectionID, 1);
1493 
1494  // The load of the GOT address has an addend of -4
1495  resolveGOTOffsetRelocation(SectionID, StubOffset + 2, GOTOffset - 4);
1496 
1497  // Fill in the value of the symbol we're targeting into the GOT
1498  addRelocationForSymbol(
1499  computeGOTOffsetRE(SectionID, GOTOffset, 0, ELF::R_X86_64_64),
1500  Value.SymbolName);
1501  }
1502 
1503  // Make the target call a call into the stub table.
1504  resolveRelocation(Section, Offset, StubAddress, ELF::R_X86_64_PC32,
1505  Addend);
1506  } else {
1507  RelocationEntry RE(SectionID, Offset, ELF::R_X86_64_PC32, Value.Addend,
1508  Value.Offset);
1509  addRelocationForSection(RE, Value.SectionID);
1510  }
1511  } else if (RelType == ELF::R_X86_64_GOTPCREL ||
1512  RelType == ELF::R_X86_64_GOTPCRELX ||
1513  RelType == ELF::R_X86_64_REX_GOTPCRELX) {
1514  uint64_t GOTOffset = allocateGOTEntries(SectionID, 1);
1515  resolveGOTOffsetRelocation(SectionID, Offset, GOTOffset + Addend);
1516 
1517  // Fill in the value of the symbol we're targeting into the GOT
1518  RelocationEntry RE = computeGOTOffsetRE(SectionID, GOTOffset, Value.Offset, ELF::R_X86_64_64);
1519  if (Value.SymbolName)
1520  addRelocationForSymbol(RE, Value.SymbolName);
1521  else
1522  addRelocationForSection(RE, Value.SectionID);
1523  } else if (RelType == ELF::R_X86_64_PC32) {
1524  Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset));
1525  processSimpleRelocation(SectionID, Offset, RelType, Value);
1526  } else if (RelType == ELF::R_X86_64_PC64) {
1527  Value.Addend += support::ulittle64_t::ref(computePlaceholderAddress(SectionID, Offset));
1528  processSimpleRelocation(SectionID, Offset, RelType, Value);
1529  } else {
1530  processSimpleRelocation(SectionID, Offset, RelType, Value);
1531  }
1532  } else {
1533  if (Arch == Triple::x86) {
1534  Value.Addend += support::ulittle32_t::ref(computePlaceholderAddress(SectionID, Offset));
1535  }
1536  processSimpleRelocation(SectionID, Offset, RelType, Value);
1537  }
1538  return ++RelI;
1539 }
1540 
1541 size_t RuntimeDyldELF::getGOTEntrySize() {
1542  // We don't use the GOT in all of these cases, but it's essentially free
1543  // to put them all here.
1544  size_t Result = 0;
1545  switch (Arch) {
1546  case Triple::x86_64:
1547  case Triple::aarch64:
1548  case Triple::aarch64_be:
1549  case Triple::ppc64:
1550  case Triple::ppc64le:
1551  case Triple::systemz:
1552  Result = sizeof(uint64_t);
1553  break;
1554  case Triple::x86:
1555  case Triple::arm:
1556  case Triple::thumb:
1557  Result = sizeof(uint32_t);
1558  break;
1559  case Triple::mips:
1560  case Triple::mipsel:
1561  case Triple::mips64:
1562  case Triple::mips64el:
1563  if (IsMipsO32ABI || IsMipsN32ABI)
1564  Result = sizeof(uint32_t);
1565  else if (IsMipsN64ABI)
1566  Result = sizeof(uint64_t);
1567  else
1568  llvm_unreachable("Mips ABI not handled");
1569  break;
1570  default:
1571  llvm_unreachable("Unsupported CPU type!");
1572  }
1573  return Result;
1574 }
1575 
1576 uint64_t RuntimeDyldELF::allocateGOTEntries(unsigned SectionID, unsigned no)
1577 {
1578  (void)SectionID; // The GOT Section is the same for all section in the object file
1579  if (GOTSectionID == 0) {
1580  GOTSectionID = Sections.size();
1581  // Reserve a section id. We'll allocate the section later
1582  // once we know the total size
1583  Sections.push_back(SectionEntry(".got", nullptr, 0, 0, 0));
1584  }
1585  uint64_t StartOffset = CurrentGOTIndex * getGOTEntrySize();
1586  CurrentGOTIndex += no;
1587  return StartOffset;
1588 }
1589 
1590 void RuntimeDyldELF::resolveGOTOffsetRelocation(unsigned SectionID, uint64_t Offset, uint64_t GOTOffset)
1591 {
1592  // Fill in the relative address of the GOT Entry into the stub
1593  RelocationEntry GOTRE(SectionID, Offset, ELF::R_X86_64_PC32, GOTOffset);
1594  addRelocationForSection(GOTRE, GOTSectionID);
1595 }
1596 
1597 RelocationEntry RuntimeDyldELF::computeGOTOffsetRE(unsigned SectionID, uint64_t GOTOffset, uint64_t SymbolOffset,
1598  uint32_t Type)
1599 {
1600  (void)SectionID; // The GOT Section is the same for all section in the object file
1601  return RelocationEntry(GOTSectionID, GOTOffset, Type, SymbolOffset);
1602 }
1603 
1605  ObjSectionToIDMap &SectionMap) {
1606  if (IsMipsO32ABI)
1607  if (!PendingRelocs.empty())
1608  return make_error<RuntimeDyldError>("Can't find matching LO16 reloc");
1609 
1610  // If necessary, allocate the global offset table
1611  if (GOTSectionID != 0) {
1612  // Allocate memory for the section
1613  size_t TotalSize = CurrentGOTIndex * getGOTEntrySize();
1614  uint8_t *Addr = MemMgr.allocateDataSection(TotalSize, getGOTEntrySize(),
1615  GOTSectionID, ".got", false);
1616  if (!Addr)
1617  return make_error<RuntimeDyldError>("Unable to allocate memory for GOT!");
1618 
1619  Sections[GOTSectionID] =
1620  SectionEntry(".got", Addr, TotalSize, TotalSize, 0);
1621 
1622  if (Checker)
1623  Checker->registerSection(Obj.getFileName(), GOTSectionID);
1624 
1625  // For now, initialize all GOT entries to zero. We'll fill them in as
1626  // needed when GOT-based relocations are applied.
1627  memset(Addr, 0, TotalSize);
1628  if (IsMipsN32ABI || IsMipsN64ABI) {
1629  // To correctly resolve Mips GOT relocations, we need a mapping from
1630  // object's sections to GOTs.
1631  for (section_iterator SI = Obj.section_begin(), SE = Obj.section_end();
1632  SI != SE; ++SI) {
1633  if (SI->relocation_begin() != SI->relocation_end()) {
1634  section_iterator RelocatedSection = SI->getRelocatedSection();
1635  ObjSectionToIDMap::iterator i = SectionMap.find(*RelocatedSection);
1636  assert (i != SectionMap.end());
1637  SectionToGOTMap[i->second] = GOTSectionID;
1638  }
1639  }
1640  GOTSymbolOffsets.clear();
1641  }
1642  }
1643 
1644  // Look for and record the EH frame section.
1645  ObjSectionToIDMap::iterator i, e;
1646  for (i = SectionMap.begin(), e = SectionMap.end(); i != e; ++i) {
1647  const SectionRef &Section = i->first;
1648  StringRef Name;
1649  Section.getName(Name);
1650  if (Name == ".eh_frame") {
1651  UnregisteredEHFrameSections.push_back(i->second);
1652  break;
1653  }
1654  }
1655 
1656  GOTSectionID = 0;
1657  CurrentGOTIndex = 0;
1658 
1659  return Error::success();
1660 }
1661 
1663  return Obj.isELF();
1664 }
1665 
1666 bool RuntimeDyldELF::relocationNeedsStub(const RelocationRef &R) const {
1667  if (Arch != Triple::x86_64)
1668  return true; // Conservative answer
1669 
1670  switch (R.getType()) {
1671  default:
1672  return true; // Conservative answer
1673 
1674 
1675  case ELF::R_X86_64_GOTPCREL:
1676  case ELF::R_X86_64_GOTPCRELX:
1677  case ELF::R_X86_64_REX_GOTPCRELX:
1678  case ELF::R_X86_64_PC32:
1679  case ELF::R_X86_64_PC64:
1680  case ELF::R_X86_64_64:
1681  // We know that these reloation types won't need a stub function. This list
1682  // can be extended as needed.
1683  return false;
1684  }
1685 }
1686 
1687 } // namespace llvm
MachineLoop * L
bool isELF() const
Definition: Binary.h:108
RelocationEntry - used to represent relocations internally in the dynamic linker. ...
void push_back(const T &Elt)
Definition: SmallVector.h:211
Represents either an error or a value T.
Definition: ErrorOr.h:68
static void or32AArch64Imm(void *L, uint64_t Imm)
Expected< StringRef > getName() const
Definition: ObjectFile.h:316
DataRefImpl getRawDataRefImpl() const
Definition: SymbolicFile.h:192
LLVM_ATTRIBUTE_NORETURN void report_fatal_error(Error Err, bool gen_crash_diag=true)
Report a serious error, calling any installed error handler.
size_t i
void writeInt16BE(uint8_t *Addr, uint16_t Value)
void logAllUnhandledErrors(Error E, raw_ostream &OS, Twine ErrorBanner)
Log all errors (if any) in E to OS.
RuntimeDyld::MemoryManager & MemMgr
uint8_t * getAddress() const
iterator find(StringRef Key)
Definition: StringMap.h:315
constexpr bool isInt< 8 >(int64_t x)
Definition: MathExtras.h:268
This class is the base class for all object file types.
Definition: ObjectFile.h:178
RuntimeDyldCheckerImpl * Checker
static uint16_t applyPPChigher(uint64_t value)
void write32le(void *P, uint32_t V)
Definition: Endian.h:339
static uint16_t applyPPChighesta(uint64_t value)
Error takeError()
Take ownership of the stored error.
DataRefImpl getRawDataRefImpl() const
Definition: ObjectFile.h:428
static uint16_t applyPPChighera(uint64_t value)
ELFType< support::little, true > ELF64LE
Definition: ELFTypes.h:82
static std::unique_ptr< RuntimeDyldELF > create(Triple::ArchType Arch, RuntimeDyld::MemoryManager &MemMgr, JITSymbolResolver &Resolver)
ELFType< support::big, false > ELF32BE
Definition: ELFTypes.h:81
static int64_t decodePPC64LocalEntryOffset(unsigned Other)
Definition: Support/ELF.h:392
unsigned SectionID
SectionID - the section this relocation points to.
This is a value type class that represents a single relocation in the list of relocations in the obje...
Definition: ObjectFile.h:41
StringRef getData() const
Definition: Binary.cpp:33
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE bool equals(StringRef RHS) const
equals - Check for string equality, this is more efficient than compare() when the relative ordering ...
Definition: StringRef.h:166
virtual void deregisterEHFrames(uint8_t *addr, uint64_t LoadAddr, size_t Size)=0
std::unique_ptr< RuntimeDyld::LoadedObjectInfo > loadObject(const object::ObjectFile &O) override
std::map< RelocationValueRef, uintptr_t > StubMap
Tagged union holding either a T or a Error.
std::error_code getName(StringRef &Result) const
Definition: ObjectFile.h:372
Function Alias Analysis false
Expected< SymbolRef::Type > getType() const
Definition: ObjectFile.h:340
uint64_t getLoadAddressWithOffset(unsigned OffsetBytes) const
Return the load address of this section with an offset.
Expected< relocation_iterator > processRelocationRef(unsigned SectionID, relocation_iterator RelI, const ObjectFile &Obj, ObjSectionToIDMap &ObjSectionToID, StubMap &Stubs) override
Parses one or more object file relocations (some object files use relocation pairs) and stores it to ...
static uint16_t applyPPChi(uint64_t value)
Expected< const typename ELFT::Sym * > getSymbol(typename ELFT::SymRange Symbols, uint32_t Index)
Definition: Object/ELF.h:236
std::enable_if<!is_simple_type< Y >::value, typename cast_retty< X, const Y >::ret_type >::type cast(const Y &Val)
Definition: Casting.h:221
format_object< Ts...> format(const char *Fmt, const Ts &...Vals)
These are helper functions used to produce formatted output.
Definition: Format.h:124
#define P(N)
void addRelocationForSymbol(const RelocationEntry &RE, StringRef SymbolName)
uint8_t * getAddressWithOffset(unsigned OffsetBytes) const
Return the address of this section with an offset.
virtual uint8_t getBytesInAddress() const =0
The number of bytes used to represent an address in this object file format.
ELFType< support::little, false > ELF32LE
Definition: ELFTypes.h:80
The instances of the Type class are immutable: once they are created, they are never changed...
Definition: Type.h:45
void registerEHFrames() override
Error errorCodeToError(std::error_code EC)
Helper for converting an std::error_code to a Error.
static uint64_t getBits(uint64_t Val, int Start, int End)
void addRelocationForSection(const RelocationEntry &RE, unsigned SectionID)
uint64_t readBytesUnaligned(uint8_t *Src, unsigned Size) const
Endian-aware read Read the least significant Size bytes from Src.
static StringRef getArchTypePrefix(ArchType Kind)
getArchTypePrefix - Get the "prefix" canonical name for the Kind architecture.
Definition: Triple.cpp:77
uint32_t Offset
Symbol resolution.
Definition: JITSymbol.h:165
static const unsigned End
ELFType< support::big, true > ELF64BE
Definition: ELFTypes.h:83
static uint16_t applyPPClo(uint64_t value)
uintptr_t getStubOffset() const
virtual basic_symbol_iterator symbol_end() const =0
virtual std::error_code getPlatformFlags(unsigned &Result) const
Returns platform-specific object flags, if any.
Definition: ObjectFile.h:270
void writeInt32BE(uint8_t *Addr, uint32_t Value)
Expected< unsigned > findOrEmitSection(const ObjectFile &Obj, const SectionRef &Section, bool IsCode, ObjSectionToIDMap &LocalSections)
Find Section in LocalSections.
section_iterator_range sections() const
Definition: ObjectFile.h:257
bool isCompatibleFile(const object::ObjectFile &Obj) const override
DenseMap< SID, SID > SectionToGOTMap
static void write(bool isBE, void *P, T V)
virtual uint8_t * allocateDataSection(uintptr_t Size, unsigned Alignment, unsigned SectionID, StringRef SectionName, bool IsReadOnly)=0
Allocate a memory block of (at least) the given size suitable for data.
StringRef getFileName() const
Definition: Binary.cpp:35
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
static uint16_t applyPPChighest(uint64_t value)
ELFT::Shdr Elf_Shdr
Definition: Object/ELF.h:46
static ErrorSuccess success()
Create a success value.
constexpr bool isInt< 32 >(int64_t x)
Definition: MathExtras.h:274
void deregisterEHFrames() override
virtual object::OwningBinary< object::ObjectFile > getObjectForDebug(const object::ObjectFile &Obj) const =0
Error finalizeLoad(const ObjectFile &Obj, ObjSectionToIDMap &SectionMap) override
virtual section_iterator section_begin() const =0
int64_t Addend
Addend - the relocation addend encoded in the instruction itself.
uint32_t RelType
RelType - relocation type.
ErrorOr< int64_t > getAddend() const
always inline
LLVM_NODISCARD bool isa(const Y &Val)
Definition: Casting.h:131
static void or32le(void *P, int32_t V)
uint8_t * createStubFunction(uint8_t *Addr, unsigned AbiVariant=0)
Emits long jump instruction to Addr.
raw_ostream & dbgs()
dbgs() - This returns a reference to a raw_ostream for debugging messages.
Definition: Debug.cpp:132
StringMap - This is an unconventional map that is specialized for handling keys that are "strings"...
Definition: StringMap.h:223
Target - Wrapper for Target specific information.
This is a value type class that represents a single symbol in the list of symbols in the object file...
Definition: ObjectFile.h:116
Expected< section_iterator > getSection() const
Get section this symbol is defined in reference to.
Definition: ObjectFile.h:336
Triple::ArchType Arch
Basic Alias true
uint64_t getType() const
Definition: ObjectFile.h:458
uint64_t Offset
Offset - offset into the section.
virtual section_iterator section_end() const =0
std::map< SectionRef, unsigned > ObjSectionToIDMap
#define I(x, y, z)
Definition: MD5.cpp:54
void writeInt64BE(uint8_t *Addr, uint64_t Value)
LLVM_ATTRIBUTE_ALWAYS_INLINE size_type size() const
Definition: SmallVector.h:135
uint32_t read32le(const void *P)
Definition: Endian.h:318
bool isLittleEndian() const
Definition: Binary.h:132
const char SectionName[]
Definition: AMDGPUPTNote.h:24
SectionEntry - represents a section emitted into memory by the dynamic linker.
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
RuntimeDyldELF(RuntimeDyld::MemoryManager &MemMgr, JITSymbolResolver &Resolver)
A raw_ostream that writes to an std::string.
Definition: raw_ostream.h:463
aarch64 promote const
LLVM Value Representation.
Definition: Value.h:71
RTDyldSymbolTable GlobalSymbolTable
Lightweight error class with error context and mandatory checking.
std::underlying_type< E >::type Mask()
Get a bitmask with 1s in all places up to the high-order bit of E's largest value.
Definition: BitmaskEnum.h:81
static void write32AArch64Addr(void *L, uint64_t Imm)
LLVM_NODISCARD LLVM_ATTRIBUTE_ALWAYS_INLINE const char * data() const
data - Get a pointer to the start of the string (which may not be null terminated).
Definition: StringRef.h:125
#define DEBUG(X)
Definition: Debug.h:100
void advanceStubOffset(unsigned StubSize)
#define LLVM_ELF_IMPORT_TYPES_ELFT(ELFT)
Definition: ELFTypes.h:128
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:47
virtual void registerEHFrames(uint8_t *Addr, uint64_t LoadAddr, size_t Size)=0
Register the EH frames with the runtime so that c++ exceptions work.
Expected< ObjSectionToIDMap > loadObjectImpl(const object::ObjectFile &Obj)
StringRef getName() const
static uint16_t applyPPCha(uint64_t value)
virtual StringRef getFileFormatName() const =0
iterator end()
Definition: StringMap.h:305
This is a value type class that represents a single section in the list of sections in the object fil...
Definition: ObjectFile.h:70