LLVM  3.7.0
ThreadSanitizer.cpp
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1 //===-- ThreadSanitizer.cpp - race detector -------------------------------===//
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 // This file is a part of ThreadSanitizer, a race detector.
11 //
12 // The tool is under development, for the details about previous versions see
13 // http://code.google.com/p/data-race-test
14 //
15 // The instrumentation phase is quite simple:
16 // - Insert calls to run-time library before every memory access.
17 // - Optimizations may apply to avoid instrumenting some of the accesses.
18 // - Insert calls at function entry/exit.
19 // The rest is handled by the run-time library.
20 //===----------------------------------------------------------------------===//
21 
23 #include "llvm/ADT/SmallSet.h"
24 #include "llvm/ADT/SmallString.h"
25 #include "llvm/ADT/SmallVector.h"
26 #include "llvm/ADT/Statistic.h"
27 #include "llvm/ADT/StringExtras.h"
30 #include "llvm/IR/DataLayout.h"
31 #include "llvm/IR/Function.h"
32 #include "llvm/IR/IRBuilder.h"
33 #include "llvm/IR/IntrinsicInst.h"
34 #include "llvm/IR/Intrinsics.h"
35 #include "llvm/IR/LLVMContext.h"
36 #include "llvm/IR/Metadata.h"
37 #include "llvm/IR/Module.h"
38 #include "llvm/IR/Type.h"
40 #include "llvm/Support/Debug.h"
45 
46 using namespace llvm;
47 
48 #define DEBUG_TYPE "tsan"
49 
51  "tsan-instrument-memory-accesses", cl::init(true),
52  cl::desc("Instrument memory accesses"), cl::Hidden);
54  "tsan-instrument-func-entry-exit", cl::init(true),
55  cl::desc("Instrument function entry and exit"), cl::Hidden);
57  "tsan-instrument-atomics", cl::init(true),
58  cl::desc("Instrument atomics"), cl::Hidden);
60  "tsan-instrument-memintrinsics", cl::init(true),
61  cl::desc("Instrument memintrinsics (memset/memcpy/memmove)"), cl::Hidden);
62 
63 STATISTIC(NumInstrumentedReads, "Number of instrumented reads");
64 STATISTIC(NumInstrumentedWrites, "Number of instrumented writes");
65 STATISTIC(NumOmittedReadsBeforeWrite,
66  "Number of reads ignored due to following writes");
67 STATISTIC(NumAccessesWithBadSize, "Number of accesses with bad size");
68 STATISTIC(NumInstrumentedVtableWrites, "Number of vtable ptr writes");
69 STATISTIC(NumInstrumentedVtableReads, "Number of vtable ptr reads");
70 STATISTIC(NumOmittedReadsFromConstantGlobals,
71  "Number of reads from constant globals");
72 STATISTIC(NumOmittedReadsFromVtable, "Number of vtable reads");
73 STATISTIC(NumOmittedNonCaptured, "Number of accesses ignored due to capturing");
74 
75 static const char *const kTsanModuleCtorName = "tsan.module_ctor";
76 static const char *const kTsanInitName = "__tsan_init";
77 
78 namespace {
79 
80 /// ThreadSanitizer: instrument the code in module to find races.
81 struct ThreadSanitizer : public FunctionPass {
82  ThreadSanitizer() : FunctionPass(ID) {}
83  const char *getPassName() const override;
84  bool runOnFunction(Function &F) override;
85  bool doInitialization(Module &M) override;
86  static char ID; // Pass identification, replacement for typeid.
87 
88  private:
89  void initializeCallbacks(Module &M);
90  bool instrumentLoadOrStore(Instruction *I, const DataLayout &DL);
91  bool instrumentAtomic(Instruction *I, const DataLayout &DL);
92  bool instrumentMemIntrinsic(Instruction *I);
93  void chooseInstructionsToInstrument(SmallVectorImpl<Instruction *> &Local,
95  const DataLayout &DL);
96  bool addrPointsToConstantData(Value *Addr);
97  int getMemoryAccessFuncIndex(Value *Addr, const DataLayout &DL);
98 
99  Type *IntptrTy;
100  IntegerType *OrdTy;
101  // Callbacks to run-time library are computed in doInitialization.
102  Function *TsanFuncEntry;
103  Function *TsanFuncExit;
104  // Accesses sizes are powers of two: 1, 2, 4, 8, 16.
105  static const size_t kNumberOfAccessSizes = 5;
106  Function *TsanRead[kNumberOfAccessSizes];
107  Function *TsanWrite[kNumberOfAccessSizes];
108  Function *TsanUnalignedRead[kNumberOfAccessSizes];
109  Function *TsanUnalignedWrite[kNumberOfAccessSizes];
110  Function *TsanAtomicLoad[kNumberOfAccessSizes];
111  Function *TsanAtomicStore[kNumberOfAccessSizes];
113  Function *TsanAtomicCAS[kNumberOfAccessSizes];
114  Function *TsanAtomicThreadFence;
115  Function *TsanAtomicSignalFence;
116  Function *TsanVptrUpdate;
117  Function *TsanVptrLoad;
118  Function *MemmoveFn, *MemcpyFn, *MemsetFn;
119  Function *TsanCtorFunction;
120 };
121 } // namespace
122 
123 char ThreadSanitizer::ID = 0;
124 INITIALIZE_PASS(ThreadSanitizer, "tsan",
125  "ThreadSanitizer: detects data races.",
126  false, false)
127 
128 const char *ThreadSanitizer::getPassName() const {
129  return "ThreadSanitizer";
130 }
131 
133  return new ThreadSanitizer();
134 }
135 
136 void ThreadSanitizer::initializeCallbacks(Module &M) {
137  IRBuilder<> IRB(M.getContext());
138  // Initialize the callbacks.
140  "__tsan_func_entry", IRB.getVoidTy(), IRB.getInt8PtrTy(), nullptr));
141  TsanFuncExit = checkSanitizerInterfaceFunction(
142  M.getOrInsertFunction("__tsan_func_exit", IRB.getVoidTy(), nullptr));
143  OrdTy = IRB.getInt32Ty();
144  for (size_t i = 0; i < kNumberOfAccessSizes; ++i) {
145  const size_t ByteSize = 1 << i;
146  const size_t BitSize = ByteSize * 8;
147  SmallString<32> ReadName("__tsan_read" + itostr(ByteSize));
149  ReadName, IRB.getVoidTy(), IRB.getInt8PtrTy(), nullptr));
150 
151  SmallString<32> WriteName("__tsan_write" + itostr(ByteSize));
153  WriteName, IRB.getVoidTy(), IRB.getInt8PtrTy(), nullptr));
154 
155  SmallString<64> UnalignedReadName("__tsan_unaligned_read" +
156  itostr(ByteSize));
157  TsanUnalignedRead[i] =
159  UnalignedReadName, IRB.getVoidTy(), IRB.getInt8PtrTy(), nullptr));
160 
161  SmallString<64> UnalignedWriteName("__tsan_unaligned_write" +
162  itostr(ByteSize));
163  TsanUnalignedWrite[i] =
165  UnalignedWriteName, IRB.getVoidTy(), IRB.getInt8PtrTy(), nullptr));
166 
167  Type *Ty = Type::getIntNTy(M.getContext(), BitSize);
168  Type *PtrTy = Ty->getPointerTo();
169  SmallString<32> AtomicLoadName("__tsan_atomic" + itostr(BitSize) +
170  "_load");
171  TsanAtomicLoad[i] = checkSanitizerInterfaceFunction(
172  M.getOrInsertFunction(AtomicLoadName, Ty, PtrTy, OrdTy, nullptr));
173 
174  SmallString<32> AtomicStoreName("__tsan_atomic" + itostr(BitSize) +
175  "_store");
177  AtomicStoreName, IRB.getVoidTy(), PtrTy, Ty, OrdTy, nullptr));
178 
179  for (int op = AtomicRMWInst::FIRST_BINOP;
181  TsanAtomicRMW[op][i] = nullptr;
182  const char *NamePart = nullptr;
183  if (op == AtomicRMWInst::Xchg)
184  NamePart = "_exchange";
185  else if (op == AtomicRMWInst::Add)
186  NamePart = "_fetch_add";
187  else if (op == AtomicRMWInst::Sub)
188  NamePart = "_fetch_sub";
189  else if (op == AtomicRMWInst::And)
190  NamePart = "_fetch_and";
191  else if (op == AtomicRMWInst::Or)
192  NamePart = "_fetch_or";
193  else if (op == AtomicRMWInst::Xor)
194  NamePart = "_fetch_xor";
195  else if (op == AtomicRMWInst::Nand)
196  NamePart = "_fetch_nand";
197  else
198  continue;
199  SmallString<32> RMWName("__tsan_atomic" + itostr(BitSize) + NamePart);
200  TsanAtomicRMW[op][i] = checkSanitizerInterfaceFunction(
201  M.getOrInsertFunction(RMWName, Ty, PtrTy, Ty, OrdTy, nullptr));
202  }
203 
204  SmallString<32> AtomicCASName("__tsan_atomic" + itostr(BitSize) +
205  "_compare_exchange_val");
207  AtomicCASName, Ty, PtrTy, Ty, Ty, OrdTy, OrdTy, nullptr));
208  }
209  TsanVptrUpdate = checkSanitizerInterfaceFunction(
210  M.getOrInsertFunction("__tsan_vptr_update", IRB.getVoidTy(),
211  IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), nullptr));
213  "__tsan_vptr_read", IRB.getVoidTy(), IRB.getInt8PtrTy(), nullptr));
214  TsanAtomicThreadFence = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
215  "__tsan_atomic_thread_fence", IRB.getVoidTy(), OrdTy, nullptr));
216  TsanAtomicSignalFence = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
217  "__tsan_atomic_signal_fence", IRB.getVoidTy(), OrdTy, nullptr));
218 
220  M.getOrInsertFunction("memmove", IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
221  IRB.getInt8PtrTy(), IntptrTy, nullptr));
223  M.getOrInsertFunction("memcpy", IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
224  IRB.getInt8PtrTy(), IntptrTy, nullptr));
226  M.getOrInsertFunction("memset", IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
227  IRB.getInt32Ty(), IntptrTy, nullptr));
228 }
229 
230 bool ThreadSanitizer::doInitialization(Module &M) {
231  const DataLayout &DL = M.getDataLayout();
232  IntptrTy = DL.getIntPtrType(M.getContext());
233  std::tie(TsanCtorFunction, std::ignore) = createSanitizerCtorAndInitFunctions(
234  M, kTsanModuleCtorName, kTsanInitName, /*InitArgTypes=*/{},
235  /*InitArgs=*/{});
236 
237  appendToGlobalCtors(M, TsanCtorFunction, 0);
238 
239  return true;
240 }
241 
242 static bool isVtableAccess(Instruction *I) {
244  return Tag->isTBAAVtableAccess();
245  return false;
246 }
247 
248 bool ThreadSanitizer::addrPointsToConstantData(Value *Addr) {
249  // If this is a GEP, just analyze its pointer operand.
250  if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Addr))
251  Addr = GEP->getPointerOperand();
252 
253  if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Addr)) {
254  if (GV->isConstant()) {
255  // Reads from constant globals can not race with any writes.
256  NumOmittedReadsFromConstantGlobals++;
257  return true;
258  }
259  } else if (LoadInst *L = dyn_cast<LoadInst>(Addr)) {
260  if (isVtableAccess(L)) {
261  // Reads from a vtable pointer can not race with any writes.
262  NumOmittedReadsFromVtable++;
263  return true;
264  }
265  }
266  return false;
267 }
268 
269 // Instrumenting some of the accesses may be proven redundant.
270 // Currently handled:
271 // - read-before-write (within same BB, no calls between)
272 // - not captured variables
273 //
274 // We do not handle some of the patterns that should not survive
275 // after the classic compiler optimizations.
276 // E.g. two reads from the same temp should be eliminated by CSE,
277 // two writes should be eliminated by DSE, etc.
278 //
279 // 'Local' is a vector of insns within the same BB (no calls between).
280 // 'All' is a vector of insns that will be instrumented.
281 void ThreadSanitizer::chooseInstructionsToInstrument(
283  const DataLayout &DL) {
284  SmallSet<Value*, 8> WriteTargets;
285  // Iterate from the end.
287  E = Local.rend(); It != E; ++It) {
288  Instruction *I = *It;
289  if (StoreInst *Store = dyn_cast<StoreInst>(I)) {
290  WriteTargets.insert(Store->getPointerOperand());
291  } else {
292  LoadInst *Load = cast<LoadInst>(I);
293  Value *Addr = Load->getPointerOperand();
294  if (WriteTargets.count(Addr)) {
295  // We will write to this temp, so no reason to analyze the read.
296  NumOmittedReadsBeforeWrite++;
297  continue;
298  }
299  if (addrPointsToConstantData(Addr)) {
300  // Addr points to some constant data -- it can not race with any writes.
301  continue;
302  }
303  }
304  Value *Addr = isa<StoreInst>(*I)
305  ? cast<StoreInst>(I)->getPointerOperand()
307  if (isa<AllocaInst>(GetUnderlyingObject(Addr, DL)) &&
308  !PointerMayBeCaptured(Addr, true, true)) {
309  // The variable is addressable but not captured, so it cannot be
310  // referenced from a different thread and participate in a data race
311  // (see llvm/Analysis/CaptureTracking.h for details).
312  NumOmittedNonCaptured++;
313  continue;
314  }
315  All.push_back(I);
316  }
317  Local.clear();
318 }
319 
320 static bool isAtomic(Instruction *I) {
321  if (LoadInst *LI = dyn_cast<LoadInst>(I))
322  return LI->isAtomic() && LI->getSynchScope() == CrossThread;
323  if (StoreInst *SI = dyn_cast<StoreInst>(I))
324  return SI->isAtomic() && SI->getSynchScope() == CrossThread;
325  if (isa<AtomicRMWInst>(I))
326  return true;
327  if (isa<AtomicCmpXchgInst>(I))
328  return true;
329  if (isa<FenceInst>(I))
330  return true;
331  return false;
332 }
333 
334 bool ThreadSanitizer::runOnFunction(Function &F) {
335  // This is required to prevent instrumenting call to __tsan_init from within
336  // the module constructor.
337  if (&F == TsanCtorFunction)
338  return false;
339  initializeCallbacks(*F.getParent());
341  SmallVector<Instruction*, 8> AllLoadsAndStores;
342  SmallVector<Instruction*, 8> LocalLoadsAndStores;
343  SmallVector<Instruction*, 8> AtomicAccesses;
344  SmallVector<Instruction*, 8> MemIntrinCalls;
345  bool Res = false;
346  bool HasCalls = false;
347  bool SanitizeFunction = F.hasFnAttribute(Attribute::SanitizeThread);
348  const DataLayout &DL = F.getParent()->getDataLayout();
349 
350  // Traverse all instructions, collect loads/stores/returns, check for calls.
351  for (auto &BB : F) {
352  for (auto &Inst : BB) {
353  if (isAtomic(&Inst))
354  AtomicAccesses.push_back(&Inst);
355  else if (isa<LoadInst>(Inst) || isa<StoreInst>(Inst))
356  LocalLoadsAndStores.push_back(&Inst);
357  else if (isa<ReturnInst>(Inst))
358  RetVec.push_back(&Inst);
359  else if (isa<CallInst>(Inst) || isa<InvokeInst>(Inst)) {
360  if (isa<MemIntrinsic>(Inst))
361  MemIntrinCalls.push_back(&Inst);
362  HasCalls = true;
363  chooseInstructionsToInstrument(LocalLoadsAndStores, AllLoadsAndStores,
364  DL);
365  }
366  }
367  chooseInstructionsToInstrument(LocalLoadsAndStores, AllLoadsAndStores, DL);
368  }
369 
370  // We have collected all loads and stores.
371  // FIXME: many of these accesses do not need to be checked for races
372  // (e.g. variables that do not escape, etc).
373 
374  // Instrument memory accesses only if we want to report bugs in the function.
375  if (ClInstrumentMemoryAccesses && SanitizeFunction)
376  for (auto Inst : AllLoadsAndStores) {
377  Res |= instrumentLoadOrStore(Inst, DL);
378  }
379 
380  // Instrument atomic memory accesses in any case (they can be used to
381  // implement synchronization).
383  for (auto Inst : AtomicAccesses) {
384  Res |= instrumentAtomic(Inst, DL);
385  }
386 
387  if (ClInstrumentMemIntrinsics && SanitizeFunction)
388  for (auto Inst : MemIntrinCalls) {
389  Res |= instrumentMemIntrinsic(Inst);
390  }
391 
392  // Instrument function entry/exit points if there were instrumented accesses.
393  if ((Res || HasCalls) && ClInstrumentFuncEntryExit) {
394  IRBuilder<> IRB(F.getEntryBlock().getFirstNonPHI());
395  Value *ReturnAddress = IRB.CreateCall(
396  Intrinsic::getDeclaration(F.getParent(), Intrinsic::returnaddress),
397  IRB.getInt32(0));
398  IRB.CreateCall(TsanFuncEntry, ReturnAddress);
399  for (auto RetInst : RetVec) {
400  IRBuilder<> IRBRet(RetInst);
401  IRBRet.CreateCall(TsanFuncExit, {});
402  }
403  Res = true;
404  }
405  return Res;
406 }
407 
408 bool ThreadSanitizer::instrumentLoadOrStore(Instruction *I,
409  const DataLayout &DL) {
410  IRBuilder<> IRB(I);
411  bool IsWrite = isa<StoreInst>(*I);
412  Value *Addr = IsWrite
413  ? cast<StoreInst>(I)->getPointerOperand()
415  int Idx = getMemoryAccessFuncIndex(Addr, DL);
416  if (Idx < 0)
417  return false;
418  if (IsWrite && isVtableAccess(I)) {
419  DEBUG(dbgs() << " VPTR : " << *I << "\n");
420  Value *StoredValue = cast<StoreInst>(I)->getValueOperand();
421  // StoredValue may be a vector type if we are storing several vptrs at once.
422  // In this case, just take the first element of the vector since this is
423  // enough to find vptr races.
424  if (isa<VectorType>(StoredValue->getType()))
425  StoredValue = IRB.CreateExtractElement(
426  StoredValue, ConstantInt::get(IRB.getInt32Ty(), 0));
427  if (StoredValue->getType()->isIntegerTy())
428  StoredValue = IRB.CreateIntToPtr(StoredValue, IRB.getInt8PtrTy());
429  // Call TsanVptrUpdate.
430  IRB.CreateCall(TsanVptrUpdate,
431  {IRB.CreatePointerCast(Addr, IRB.getInt8PtrTy()),
432  IRB.CreatePointerCast(StoredValue, IRB.getInt8PtrTy())});
433  NumInstrumentedVtableWrites++;
434  return true;
435  }
436  if (!IsWrite && isVtableAccess(I)) {
437  IRB.CreateCall(TsanVptrLoad,
438  IRB.CreatePointerCast(Addr, IRB.getInt8PtrTy()));
439  NumInstrumentedVtableReads++;
440  return true;
441  }
442  const unsigned Alignment = IsWrite
443  ? cast<StoreInst>(I)->getAlignment()
444  : cast<LoadInst>(I)->getAlignment();
445  Type *OrigTy = cast<PointerType>(Addr->getType())->getElementType();
446  const uint32_t TypeSize = DL.getTypeStoreSizeInBits(OrigTy);
447  Value *OnAccessFunc = nullptr;
448  if (Alignment == 0 || Alignment >= 8 || (Alignment % (TypeSize / 8)) == 0)
449  OnAccessFunc = IsWrite ? TsanWrite[Idx] : TsanRead[Idx];
450  else
451  OnAccessFunc = IsWrite ? TsanUnalignedWrite[Idx] : TsanUnalignedRead[Idx];
452  IRB.CreateCall(OnAccessFunc, IRB.CreatePointerCast(Addr, IRB.getInt8PtrTy()));
453  if (IsWrite) NumInstrumentedWrites++;
454  else NumInstrumentedReads++;
455  return true;
456 }
457 
459  uint32_t v = 0;
460  switch (ord) {
461  case NotAtomic: llvm_unreachable("unexpected atomic ordering!");
462  case Unordered: // Fall-through.
463  case Monotonic: v = 0; break;
464  // case Consume: v = 1; break; // Not specified yet.
465  case Acquire: v = 2; break;
466  case Release: v = 3; break;
467  case AcquireRelease: v = 4; break;
468  case SequentiallyConsistent: v = 5; break;
469  }
470  return IRB->getInt32(v);
471 }
472 
473 // If a memset intrinsic gets inlined by the code gen, we will miss races on it.
474 // So, we either need to ensure the intrinsic is not inlined, or instrument it.
475 // We do not instrument memset/memmove/memcpy intrinsics (too complicated),
476 // instead we simply replace them with regular function calls, which are then
477 // intercepted by the run-time.
478 // Since tsan is running after everyone else, the calls should not be
479 // replaced back with intrinsics. If that becomes wrong at some point,
480 // we will need to call e.g. __tsan_memset to avoid the intrinsics.
481 bool ThreadSanitizer::instrumentMemIntrinsic(Instruction *I) {
482  IRBuilder<> IRB(I);
483  if (MemSetInst *M = dyn_cast<MemSetInst>(I)) {
484  IRB.CreateCall(
485  MemsetFn,
486  {IRB.CreatePointerCast(M->getArgOperand(0), IRB.getInt8PtrTy()),
487  IRB.CreateIntCast(M->getArgOperand(1), IRB.getInt32Ty(), false),
488  IRB.CreateIntCast(M->getArgOperand(2), IntptrTy, false)});
489  I->eraseFromParent();
490  } else if (MemTransferInst *M = dyn_cast<MemTransferInst>(I)) {
491  IRB.CreateCall(
492  isa<MemCpyInst>(M) ? MemcpyFn : MemmoveFn,
493  {IRB.CreatePointerCast(M->getArgOperand(0), IRB.getInt8PtrTy()),
494  IRB.CreatePointerCast(M->getArgOperand(1), IRB.getInt8PtrTy()),
495  IRB.CreateIntCast(M->getArgOperand(2), IntptrTy, false)});
496  I->eraseFromParent();
497  }
498  return false;
499 }
500 
501 // Both llvm and ThreadSanitizer atomic operations are based on C++11/C1x
502 // standards. For background see C++11 standard. A slightly older, publicly
503 // available draft of the standard (not entirely up-to-date, but close enough
504 // for casual browsing) is available here:
505 // http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2011/n3242.pdf
506 // The following page contains more background information:
507 // http://www.hpl.hp.com/personal/Hans_Boehm/c++mm/
508 
509 bool ThreadSanitizer::instrumentAtomic(Instruction *I, const DataLayout &DL) {
510  IRBuilder<> IRB(I);
511  if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
512  Value *Addr = LI->getPointerOperand();
513  int Idx = getMemoryAccessFuncIndex(Addr, DL);
514  if (Idx < 0)
515  return false;
516  const size_t ByteSize = 1 << Idx;
517  const size_t BitSize = ByteSize * 8;
518  Type *Ty = Type::getIntNTy(IRB.getContext(), BitSize);
519  Type *PtrTy = Ty->getPointerTo();
520  Value *Args[] = {IRB.CreatePointerCast(Addr, PtrTy),
521  createOrdering(&IRB, LI->getOrdering())};
522  CallInst *C = CallInst::Create(TsanAtomicLoad[Idx], Args);
523  ReplaceInstWithInst(I, C);
524 
525  } else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
526  Value *Addr = SI->getPointerOperand();
527  int Idx = getMemoryAccessFuncIndex(Addr, DL);
528  if (Idx < 0)
529  return false;
530  const size_t ByteSize = 1 << Idx;
531  const size_t BitSize = ByteSize * 8;
532  Type *Ty = Type::getIntNTy(IRB.getContext(), BitSize);
533  Type *PtrTy = Ty->getPointerTo();
534  Value *Args[] = {IRB.CreatePointerCast(Addr, PtrTy),
535  IRB.CreateIntCast(SI->getValueOperand(), Ty, false),
536  createOrdering(&IRB, SI->getOrdering())};
537  CallInst *C = CallInst::Create(TsanAtomicStore[Idx], Args);
538  ReplaceInstWithInst(I, C);
539  } else if (AtomicRMWInst *RMWI = dyn_cast<AtomicRMWInst>(I)) {
540  Value *Addr = RMWI->getPointerOperand();
541  int Idx = getMemoryAccessFuncIndex(Addr, DL);
542  if (Idx < 0)
543  return false;
544  Function *F = TsanAtomicRMW[RMWI->getOperation()][Idx];
545  if (!F)
546  return false;
547  const size_t ByteSize = 1 << Idx;
548  const size_t BitSize = ByteSize * 8;
549  Type *Ty = Type::getIntNTy(IRB.getContext(), BitSize);
550  Type *PtrTy = Ty->getPointerTo();
551  Value *Args[] = {IRB.CreatePointerCast(Addr, PtrTy),
552  IRB.CreateIntCast(RMWI->getValOperand(), Ty, false),
553  createOrdering(&IRB, RMWI->getOrdering())};
554  CallInst *C = CallInst::Create(F, Args);
555  ReplaceInstWithInst(I, C);
556  } else if (AtomicCmpXchgInst *CASI = dyn_cast<AtomicCmpXchgInst>(I)) {
557  Value *Addr = CASI->getPointerOperand();
558  int Idx = getMemoryAccessFuncIndex(Addr, DL);
559  if (Idx < 0)
560  return false;
561  const size_t ByteSize = 1 << Idx;
562  const size_t BitSize = ByteSize * 8;
563  Type *Ty = Type::getIntNTy(IRB.getContext(), BitSize);
564  Type *PtrTy = Ty->getPointerTo();
565  Value *Args[] = {IRB.CreatePointerCast(Addr, PtrTy),
566  IRB.CreateIntCast(CASI->getCompareOperand(), Ty, false),
567  IRB.CreateIntCast(CASI->getNewValOperand(), Ty, false),
568  createOrdering(&IRB, CASI->getSuccessOrdering()),
569  createOrdering(&IRB, CASI->getFailureOrdering())};
570  CallInst *C = IRB.CreateCall(TsanAtomicCAS[Idx], Args);
571  Value *Success = IRB.CreateICmpEQ(C, CASI->getCompareOperand());
572 
573  Value *Res = IRB.CreateInsertValue(UndefValue::get(CASI->getType()), C, 0);
574  Res = IRB.CreateInsertValue(Res, Success, 1);
575 
576  I->replaceAllUsesWith(Res);
577  I->eraseFromParent();
578  } else if (FenceInst *FI = dyn_cast<FenceInst>(I)) {
579  Value *Args[] = {createOrdering(&IRB, FI->getOrdering())};
580  Function *F = FI->getSynchScope() == SingleThread ?
581  TsanAtomicSignalFence : TsanAtomicThreadFence;
582  CallInst *C = CallInst::Create(F, Args);
583  ReplaceInstWithInst(I, C);
584  }
585  return true;
586 }
587 
588 int ThreadSanitizer::getMemoryAccessFuncIndex(Value *Addr,
589  const DataLayout &DL) {
590  Type *OrigPtrTy = Addr->getType();
591  Type *OrigTy = cast<PointerType>(OrigPtrTy)->getElementType();
592  assert(OrigTy->isSized());
593  uint32_t TypeSize = DL.getTypeStoreSizeInBits(OrigTy);
594  if (TypeSize != 8 && TypeSize != 16 &&
595  TypeSize != 32 && TypeSize != 64 && TypeSize != 128) {
596  NumAccessesWithBadSize++;
597  // Ignore all unusual sizes.
598  return -1;
599  }
600  size_t Idx = countTrailingZeros(TypeSize / 8);
601  assert(Idx < kNumberOfAccessSizes);
602  return Idx;
603 }
iplist< Instruction >::iterator eraseFromParent()
eraseFromParent - This method unlinks 'this' from the containing basic block and deletes it...
Definition: Instruction.cpp:70
A parsed version of the target data layout string in and methods for querying it. ...
Definition: DataLayout.h:104
void ReplaceInstWithInst(BasicBlock::InstListType &BIL, BasicBlock::iterator &BI, Instruction *I)
ReplaceInstWithInst - Replace the instruction specified by BI with the instruction specified by I...
Function * checkSanitizerInterfaceFunction(Constant *FuncOrBitcast)
Definition: ModuleUtils.cpp:98
STATISTIC(NumFunctions,"Total number of functions")
A Module instance is used to store all the information related to an LLVM module. ...
Definition: Module.h:114
FenceInst - an instruction for ordering other memory operations.
Definition: Instructions.h:445
AtomicCmpXchgInst - an instruction that atomically checks whether a specified value is in a memory lo...
Definition: Instructions.h:515
void appendToGlobalCtors(Module &M, Function *F, int Priority)
Append F to the list of global ctors of module M with the given Priority.
Definition: ModuleUtils.cpp:73
CallInst - This class represents a function call, abstracting a target machine's calling convention...
This file contains the declarations for metadata subclasses.
MemSetInst - This class wraps the llvm.memset intrinsic.
Metadata node.
Definition: Metadata.h:740
F(f)
LoadInst - an instruction for reading from memory.
Definition: Instructions.h:177
AtomicRMWInst - an instruction that atomically reads a memory location, combines it with another valu...
Definition: Instructions.h:674
Hexagon Common GEP
#define op(i)
static cl::opt< bool > ClInstrumentAtomics("tsan-instrument-atomics", cl::init(true), cl::desc("Instrument atomics"), cl::Hidden)
static Value * getPointerOperand(Instruction &Inst)
static CallInst * Create(Value *Func, ArrayRef< Value * > Args, const Twine &NameStr="", Instruction *InsertBefore=nullptr)
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
Definition: ErrorHandling.h:98
This class consists of common code factored out of the SmallVector class to reduce code duplication b...
Definition: APInt.h:33
This provides a uniform API for creating instructions and inserting them into a basic block: either a...
Definition: IRBuilder.h:517
bool isSized(SmallPtrSetImpl< const Type * > *Visited=nullptr) const
isSized - Return true if it makes sense to take the size of this type.
Definition: Type.h:268
AtomicOrdering
Definition: Instructions.h:38
FunctionPass * createThreadSanitizerPass()
SmallString - A SmallString is just a SmallVector with methods and accessors that make it work better...
Definition: SmallString.h:25
Function * getDeclaration(Module *M, ID id, ArrayRef< Type * > Tys=None)
Create or insert an LLVM Function declaration for an intrinsic, and return it.
Definition: Function.cpp:866
StoreInst - an instruction for storing to memory.
Definition: Instructions.h:316
void replaceAllUsesWith(Value *V)
Change all uses of this to point to a new Value.
Definition: Value.cpp:351
std::enable_if<!is_simple_type< Y >::value, typename cast_retty< X, const Y >::ret_type >::type cast(const Y &Val)
Definition: Casting.h:222
GetElementPtrInst - an instruction for type-safe pointer arithmetic to access elements of arrays and ...
Definition: Instructions.h:830
static const size_t kNumberOfAccessSizes
initializer< Ty > init(const Ty &Val)
Definition: CommandLine.h:325
std::size_t countTrailingZeros(T Val, ZeroBehavior ZB=ZB_Width)
Count number of 0's from the least significant bit to the most stopping at the first 1...
Definition: MathExtras.h:109
Constant * getOrInsertFunction(StringRef Name, FunctionType *T, AttributeSet AttributeList)
Look up the specified function in the module symbol table.
Definition: Module.cpp:115
The instances of the Type class are immutable: once they are created, they are never changed...
Definition: Type.h:45
uint64_t getTypeStoreSizeInBits(Type *Ty) const
Returns the maximum number of bits that may be overwritten by storing the specified type; always a mu...
Definition: DataLayout.h:379
static const char *const kTsanModuleCtorName
SmallSet - This maintains a set of unique values, optimizing for the case when the set is small (less...
Definition: SmallSet.h:32
FunctionPass class - This class is used to implement most global optimizations.
Definition: Pass.h:294
Value * getPointerOperand()
Definition: Instructions.h:284
Class to represent integer types.
Definition: DerivedTypes.h:37
std::pair< NoneType, bool > insert(const T &V)
insert - Insert an element into the set if it isn't already there.
Definition: SmallSet.h:69
static UndefValue * get(Type *T)
get() - Static factory methods - Return an 'undef' object of the specified type.
Definition: Constants.cpp:1473
static std::string itostr(int64_t X)
Definition: StringExtras.h:109
static cl::opt< bool > ClInstrumentFuncEntryExit("tsan-instrument-func-entry-exit", cl::init(true), cl::desc("Instrument function entry and exit"), cl::Hidden)
bool PointerMayBeCaptured(const Value *V, bool ReturnCaptures, bool StoreCaptures)
PointerMayBeCaptured - Return true if this pointer value may be captured by the enclosing function (w...
static bool isAtomic(Instruction *I)
PointerType * getPointerTo(unsigned AddrSpace=0)
getPointerTo - Return a pointer to the current type.
Definition: Type.cpp:764
Value * GetUnderlyingObject(Value *V, const DataLayout &DL, unsigned MaxLookup=6)
GetUnderlyingObject - This method strips off any GEP address adjustments and pointer casts from the s...
#define INITIALIZE_PASS(passName, arg, name, cfg, analysis)
Definition: PassSupport.h:56
size_type count(const T &V) const
count - Return 1 if the element is in the set, 0 otherwise.
Definition: SmallSet.h:53
IntegerType * getIntPtrType(LLVMContext &C, unsigned AddressSpace=0) const
Returns an integer type with size at least as big as that of a pointer in the given address space...
Definition: DataLayout.cpp:694
This is the shared class of boolean and integer constants.
Definition: Constants.h:47
This is a 'vector' (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:861
Module.h This file contains the declarations for the Module class.
Type * getType() const
All values are typed, get the type of this value.
Definition: Value.h:222
MDNode * getMetadata(unsigned KindID) const
getMetadata - Get the metadata of given kind attached to this Instruction.
Definition: Instruction.h:167
ConstantInt * getInt32(uint32_t C)
Get a constant 32-bit value.
Definition: IRBuilder.h:266
static IntegerType * getIntNTy(LLVMContext &C, unsigned N)
Definition: Type.cpp:243
static Constant * get(Type *Ty, uint64_t V, bool isSigned=false)
If Ty is a vector type, return a Constant with a splat of the given value.
Definition: Constants.cpp:582
static ConstantInt * createOrdering(IRBuilder<> *IRB, AtomicOrdering ord)
raw_ostream & dbgs()
dbgs() - This returns a reference to a raw_ostream for debugging messages.
Definition: Debug.cpp:123
bool isIntegerTy() const
isIntegerTy - True if this is an instance of IntegerType.
Definition: Type.h:193
#define Success
ThreadSanitizer is on.
Definition: Attributes.h:116
MemTransferInst - This class wraps the llvm.memcpy/memmove intrinsics.
const DataLayout & getDataLayout() const
Get the data layout for the module's target platform.
Definition: Module.cpp:372
bool hasFnAttribute(Attribute::AttrKind Kind) const
Return true if the function has the attribute.
Definition: Function.h:217
#define I(x, y, z)
Definition: MD5.cpp:54
static cl::opt< bool > ClInstrumentMemoryAccesses("tsan-instrument-memory-accesses", cl::init(true), cl::desc("Instrument memory accesses"), cl::Hidden)
std::pair< Function *, Function * > createSanitizerCtorAndInitFunctions(Module &M, StringRef CtorName, StringRef InitName, ArrayRef< Type * > InitArgTypes, ArrayRef< Value * > InitArgs)
Creates sanitizer constructor function, and calls sanitizer's init function from it.
static cl::opt< bool > ClInstrumentMemIntrinsics("tsan-instrument-memintrinsics", cl::init(true), cl::desc("Instrument memintrinsics (memset/memcpy/memmove)"), cl::Hidden)
static const char *const kTsanInitName
aarch64 promote const
Module * getParent()
Get the module that this global value is contained inside of...
Definition: GlobalValue.h:365
LLVM Value Representation.
Definition: Value.h:69
#define DEBUG(X)
Definition: Debug.h:92
C - The default llvm calling convention, compatible with C.
Definition: CallingConv.h:34
static bool isVtableAccess(Instruction *I)
LLVMContext & getContext() const
Get the global data context.
Definition: Module.h:265