1 //===-- ThreadSanitizer.cpp - race detector -------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file is a part of ThreadSanitizer, a race detector.
12 // The tool is under development, for the details about previous versions see
13 // http://code.google.com/p/data-race-test
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 //===----------------------------------------------------------------------===//
22 #include "llvm/Transforms/Instrumentation.h"
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"
28 #include "llvm/Analysis/CaptureTracking.h"
29 #include "llvm/Analysis/ValueTracking.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"
39 #include "llvm/Support/CommandLine.h"
40 #include "llvm/Support/Debug.h"
41 #include "llvm/Support/MathExtras.h"
42 #include "llvm/Support/raw_ostream.h"
43 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
44 #include "llvm/Transforms/Utils/ModuleUtils.h"
48 #define DEBUG_TYPE "tsan"
50 static cl::opt<bool> ClInstrumentMemoryAccesses(
51 "tsan-instrument-memory-accesses", cl::init(true),
52 cl::desc("Instrument memory accesses"), cl::Hidden);
53 static cl::opt<bool> ClInstrumentFuncEntryExit(
54 "tsan-instrument-func-entry-exit", cl::init(true),
55 cl::desc("Instrument function entry and exit"), cl::Hidden);
56 static cl::opt<bool> ClInstrumentAtomics(
57 "tsan-instrument-atomics", cl::init(true),
58 cl::desc("Instrument atomics"), cl::Hidden);
59 static cl::opt<bool> ClInstrumentMemIntrinsics(
60 "tsan-instrument-memintrinsics", cl::init(true),
61 cl::desc("Instrument memintrinsics (memset/memcpy/memmove)"), cl::Hidden);
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");
75 static const char *const kTsanModuleCtorName = "tsan.module_ctor";
76 static const char *const kTsanInitName = "__tsan_init";
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.
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,
94 SmallVectorImpl<Instruction *> &All,
95 const DataLayout &DL);
96 bool addrPointsToConstantData(Value *Addr);
97 int getMemoryAccessFuncIndex(Value *Addr, const DataLayout &DL);
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];
112 Function *TsanAtomicRMW[AtomicRMWInst::LAST_BINOP + 1][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;
123 char ThreadSanitizer::ID = 0;
124 INITIALIZE_PASS(ThreadSanitizer, "tsan",
125 "ThreadSanitizer: detects data races.",
128 const char *ThreadSanitizer::getPassName() const {
129 return "ThreadSanitizer";
132 FunctionPass *llvm::createThreadSanitizerPass() {
133 return new ThreadSanitizer();
136 void ThreadSanitizer::initializeCallbacks(Module &M) {
137 IRBuilder<> IRB(M.getContext());
138 // Initialize the callbacks.
139 TsanFuncEntry = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
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 unsigned ByteSize = 1U << i;
146 const unsigned BitSize = ByteSize * 8;
147 std::string ByteSizeStr = utostr(ByteSize);
148 std::string BitSizeStr = utostr(BitSize);
149 SmallString<32> ReadName("__tsan_read" + ByteSizeStr);
150 TsanRead[i] = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
151 ReadName, IRB.getVoidTy(), IRB.getInt8PtrTy(), nullptr));
153 SmallString<32> WriteName("__tsan_write" + ByteSizeStr);
154 TsanWrite[i] = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
155 WriteName, IRB.getVoidTy(), IRB.getInt8PtrTy(), nullptr));
157 SmallString<64> UnalignedReadName("__tsan_unaligned_read" + ByteSizeStr);
158 TsanUnalignedRead[i] =
159 checkSanitizerInterfaceFunction(M.getOrInsertFunction(
160 UnalignedReadName, IRB.getVoidTy(), IRB.getInt8PtrTy(), nullptr));
162 SmallString<64> UnalignedWriteName("__tsan_unaligned_write" + ByteSizeStr);
163 TsanUnalignedWrite[i] =
164 checkSanitizerInterfaceFunction(M.getOrInsertFunction(
165 UnalignedWriteName, IRB.getVoidTy(), IRB.getInt8PtrTy(), nullptr));
167 Type *Ty = Type::getIntNTy(M.getContext(), BitSize);
168 Type *PtrTy = Ty->getPointerTo();
169 SmallString<32> AtomicLoadName("__tsan_atomic" + BitSizeStr + "_load");
170 TsanAtomicLoad[i] = checkSanitizerInterfaceFunction(
171 M.getOrInsertFunction(AtomicLoadName, Ty, PtrTy, OrdTy, nullptr));
173 SmallString<32> AtomicStoreName("__tsan_atomic" + BitSizeStr + "_store");
174 TsanAtomicStore[i] = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
175 AtomicStoreName, IRB.getVoidTy(), PtrTy, Ty, OrdTy, nullptr));
177 for (int op = AtomicRMWInst::FIRST_BINOP;
178 op <= AtomicRMWInst::LAST_BINOP; ++op) {
179 TsanAtomicRMW[op][i] = nullptr;
180 const char *NamePart = nullptr;
181 if (op == AtomicRMWInst::Xchg)
182 NamePart = "_exchange";
183 else if (op == AtomicRMWInst::Add)
184 NamePart = "_fetch_add";
185 else if (op == AtomicRMWInst::Sub)
186 NamePart = "_fetch_sub";
187 else if (op == AtomicRMWInst::And)
188 NamePart = "_fetch_and";
189 else if (op == AtomicRMWInst::Or)
190 NamePart = "_fetch_or";
191 else if (op == AtomicRMWInst::Xor)
192 NamePart = "_fetch_xor";
193 else if (op == AtomicRMWInst::Nand)
194 NamePart = "_fetch_nand";
197 SmallString<32> RMWName("__tsan_atomic" + itostr(BitSize) + NamePart);
198 TsanAtomicRMW[op][i] = checkSanitizerInterfaceFunction(
199 M.getOrInsertFunction(RMWName, Ty, PtrTy, Ty, OrdTy, nullptr));
202 SmallString<32> AtomicCASName("__tsan_atomic" + BitSizeStr +
203 "_compare_exchange_val");
204 TsanAtomicCAS[i] = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
205 AtomicCASName, Ty, PtrTy, Ty, Ty, OrdTy, OrdTy, nullptr));
207 TsanVptrUpdate = checkSanitizerInterfaceFunction(
208 M.getOrInsertFunction("__tsan_vptr_update", IRB.getVoidTy(),
209 IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), nullptr));
210 TsanVptrLoad = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
211 "__tsan_vptr_read", IRB.getVoidTy(), IRB.getInt8PtrTy(), nullptr));
212 TsanAtomicThreadFence = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
213 "__tsan_atomic_thread_fence", IRB.getVoidTy(), OrdTy, nullptr));
214 TsanAtomicSignalFence = checkSanitizerInterfaceFunction(M.getOrInsertFunction(
215 "__tsan_atomic_signal_fence", IRB.getVoidTy(), OrdTy, nullptr));
217 MemmoveFn = checkSanitizerInterfaceFunction(
218 M.getOrInsertFunction("memmove", IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
219 IRB.getInt8PtrTy(), IntptrTy, nullptr));
220 MemcpyFn = checkSanitizerInterfaceFunction(
221 M.getOrInsertFunction("memcpy", IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
222 IRB.getInt8PtrTy(), IntptrTy, nullptr));
223 MemsetFn = checkSanitizerInterfaceFunction(
224 M.getOrInsertFunction("memset", IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
225 IRB.getInt32Ty(), IntptrTy, nullptr));
228 bool ThreadSanitizer::doInitialization(Module &M) {
229 const DataLayout &DL = M.getDataLayout();
230 IntptrTy = DL.getIntPtrType(M.getContext());
231 std::tie(TsanCtorFunction, std::ignore) = createSanitizerCtorAndInitFunctions(
232 M, kTsanModuleCtorName, kTsanInitName, /*InitArgTypes=*/{},
235 appendToGlobalCtors(M, TsanCtorFunction, 0);
240 static bool isVtableAccess(Instruction *I) {
241 if (MDNode *Tag = I->getMetadata(LLVMContext::MD_tbaa))
242 return Tag->isTBAAVtableAccess();
246 bool ThreadSanitizer::addrPointsToConstantData(Value *Addr) {
247 // If this is a GEP, just analyze its pointer operand.
248 if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Addr))
249 Addr = GEP->getPointerOperand();
251 if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Addr)) {
252 if (GV->isConstant()) {
253 // Reads from constant globals can not race with any writes.
254 NumOmittedReadsFromConstantGlobals++;
257 } else if (LoadInst *L = dyn_cast<LoadInst>(Addr)) {
258 if (isVtableAccess(L)) {
259 // Reads from a vtable pointer can not race with any writes.
260 NumOmittedReadsFromVtable++;
267 // Instrumenting some of the accesses may be proven redundant.
268 // Currently handled:
269 // - read-before-write (within same BB, no calls between)
270 // - not captured variables
272 // We do not handle some of the patterns that should not survive
273 // after the classic compiler optimizations.
274 // E.g. two reads from the same temp should be eliminated by CSE,
275 // two writes should be eliminated by DSE, etc.
277 // 'Local' is a vector of insns within the same BB (no calls between).
278 // 'All' is a vector of insns that will be instrumented.
279 void ThreadSanitizer::chooseInstructionsToInstrument(
280 SmallVectorImpl<Instruction *> &Local, SmallVectorImpl<Instruction *> &All,
281 const DataLayout &DL) {
282 SmallSet<Value*, 8> WriteTargets;
283 // Iterate from the end.
284 for (SmallVectorImpl<Instruction*>::reverse_iterator It = Local.rbegin(),
285 E = Local.rend(); It != E; ++It) {
286 Instruction *I = *It;
287 if (StoreInst *Store = dyn_cast<StoreInst>(I)) {
288 WriteTargets.insert(Store->getPointerOperand());
290 LoadInst *Load = cast<LoadInst>(I);
291 Value *Addr = Load->getPointerOperand();
292 if (WriteTargets.count(Addr)) {
293 // We will write to this temp, so no reason to analyze the read.
294 NumOmittedReadsBeforeWrite++;
297 if (addrPointsToConstantData(Addr)) {
298 // Addr points to some constant data -- it can not race with any writes.
302 Value *Addr = isa<StoreInst>(*I)
303 ? cast<StoreInst>(I)->getPointerOperand()
304 : cast<LoadInst>(I)->getPointerOperand();
305 if (isa<AllocaInst>(GetUnderlyingObject(Addr, DL)) &&
306 !PointerMayBeCaptured(Addr, true, true)) {
307 // The variable is addressable but not captured, so it cannot be
308 // referenced from a different thread and participate in a data race
309 // (see llvm/Analysis/CaptureTracking.h for details).
310 NumOmittedNonCaptured++;
318 static bool isAtomic(Instruction *I) {
319 if (LoadInst *LI = dyn_cast<LoadInst>(I))
320 return LI->isAtomic() && LI->getSynchScope() == CrossThread;
321 if (StoreInst *SI = dyn_cast<StoreInst>(I))
322 return SI->isAtomic() && SI->getSynchScope() == CrossThread;
323 if (isa<AtomicRMWInst>(I))
325 if (isa<AtomicCmpXchgInst>(I))
327 if (isa<FenceInst>(I))
332 bool ThreadSanitizer::runOnFunction(Function &F) {
333 // This is required to prevent instrumenting call to __tsan_init from within
334 // the module constructor.
335 if (&F == TsanCtorFunction)
337 initializeCallbacks(*F.getParent());
338 SmallVector<Instruction*, 8> RetVec;
339 SmallVector<Instruction*, 8> AllLoadsAndStores;
340 SmallVector<Instruction*, 8> LocalLoadsAndStores;
341 SmallVector<Instruction*, 8> AtomicAccesses;
342 SmallVector<Instruction*, 8> MemIntrinCalls;
344 bool HasCalls = false;
345 bool SanitizeFunction = F.hasFnAttribute(Attribute::SanitizeThread);
346 const DataLayout &DL = F.getParent()->getDataLayout();
348 // Traverse all instructions, collect loads/stores/returns, check for calls.
350 for (auto &Inst : BB) {
352 AtomicAccesses.push_back(&Inst);
353 else if (isa<LoadInst>(Inst) || isa<StoreInst>(Inst))
354 LocalLoadsAndStores.push_back(&Inst);
355 else if (isa<ReturnInst>(Inst))
356 RetVec.push_back(&Inst);
357 else if (isa<CallInst>(Inst) || isa<InvokeInst>(Inst)) {
358 if (isa<MemIntrinsic>(Inst))
359 MemIntrinCalls.push_back(&Inst);
361 chooseInstructionsToInstrument(LocalLoadsAndStores, AllLoadsAndStores,
365 chooseInstructionsToInstrument(LocalLoadsAndStores, AllLoadsAndStores, DL);
368 // We have collected all loads and stores.
369 // FIXME: many of these accesses do not need to be checked for races
370 // (e.g. variables that do not escape, etc).
372 // Instrument memory accesses only if we want to report bugs in the function.
373 if (ClInstrumentMemoryAccesses && SanitizeFunction)
374 for (auto Inst : AllLoadsAndStores) {
375 Res |= instrumentLoadOrStore(Inst, DL);
378 // Instrument atomic memory accesses in any case (they can be used to
379 // implement synchronization).
380 if (ClInstrumentAtomics)
381 for (auto Inst : AtomicAccesses) {
382 Res |= instrumentAtomic(Inst, DL);
385 if (ClInstrumentMemIntrinsics && SanitizeFunction)
386 for (auto Inst : MemIntrinCalls) {
387 Res |= instrumentMemIntrinsic(Inst);
390 // Instrument function entry/exit points if there were instrumented accesses.
391 if ((Res || HasCalls) && ClInstrumentFuncEntryExit) {
392 IRBuilder<> IRB(F.getEntryBlock().getFirstNonPHI());
393 Value *ReturnAddress = IRB.CreateCall(
394 Intrinsic::getDeclaration(F.getParent(), Intrinsic::returnaddress),
396 IRB.CreateCall(TsanFuncEntry, ReturnAddress);
397 for (auto RetInst : RetVec) {
398 IRBuilder<> IRBRet(RetInst);
399 IRBRet.CreateCall(TsanFuncExit, {});
406 bool ThreadSanitizer::instrumentLoadOrStore(Instruction *I,
407 const DataLayout &DL) {
409 bool IsWrite = isa<StoreInst>(*I);
410 Value *Addr = IsWrite
411 ? cast<StoreInst>(I)->getPointerOperand()
412 : cast<LoadInst>(I)->getPointerOperand();
413 int Idx = getMemoryAccessFuncIndex(Addr, DL);
416 if (IsWrite && isVtableAccess(I)) {
417 DEBUG(dbgs() << " VPTR : " << *I << "\n");
418 Value *StoredValue = cast<StoreInst>(I)->getValueOperand();
419 // StoredValue may be a vector type if we are storing several vptrs at once.
420 // In this case, just take the first element of the vector since this is
421 // enough to find vptr races.
422 if (isa<VectorType>(StoredValue->getType()))
423 StoredValue = IRB.CreateExtractElement(
424 StoredValue, ConstantInt::get(IRB.getInt32Ty(), 0));
425 if (StoredValue->getType()->isIntegerTy())
426 StoredValue = IRB.CreateIntToPtr(StoredValue, IRB.getInt8PtrTy());
427 // Call TsanVptrUpdate.
428 IRB.CreateCall(TsanVptrUpdate,
429 {IRB.CreatePointerCast(Addr, IRB.getInt8PtrTy()),
430 IRB.CreatePointerCast(StoredValue, IRB.getInt8PtrTy())});
431 NumInstrumentedVtableWrites++;
434 if (!IsWrite && isVtableAccess(I)) {
435 IRB.CreateCall(TsanVptrLoad,
436 IRB.CreatePointerCast(Addr, IRB.getInt8PtrTy()));
437 NumInstrumentedVtableReads++;
440 const unsigned Alignment = IsWrite
441 ? cast<StoreInst>(I)->getAlignment()
442 : cast<LoadInst>(I)->getAlignment();
443 Type *OrigTy = cast<PointerType>(Addr->getType())->getElementType();
444 const uint32_t TypeSize = DL.getTypeStoreSizeInBits(OrigTy);
445 Value *OnAccessFunc = nullptr;
446 if (Alignment == 0 || Alignment >= 8 || (Alignment % (TypeSize / 8)) == 0)
447 OnAccessFunc = IsWrite ? TsanWrite[Idx] : TsanRead[Idx];
449 OnAccessFunc = IsWrite ? TsanUnalignedWrite[Idx] : TsanUnalignedRead[Idx];
450 IRB.CreateCall(OnAccessFunc, IRB.CreatePointerCast(Addr, IRB.getInt8PtrTy()));
451 if (IsWrite) NumInstrumentedWrites++;
452 else NumInstrumentedReads++;
456 static ConstantInt *createOrdering(IRBuilder<> *IRB, AtomicOrdering ord) {
459 case NotAtomic: llvm_unreachable("unexpected atomic ordering!");
460 case Unordered: // Fall-through.
461 case Monotonic: v = 0; break;
462 // case Consume: v = 1; break; // Not specified yet.
463 case Acquire: v = 2; break;
464 case Release: v = 3; break;
465 case AcquireRelease: v = 4; break;
466 case SequentiallyConsistent: v = 5; break;
468 return IRB->getInt32(v);
471 // If a memset intrinsic gets inlined by the code gen, we will miss races on it.
472 // So, we either need to ensure the intrinsic is not inlined, or instrument it.
473 // We do not instrument memset/memmove/memcpy intrinsics (too complicated),
474 // instead we simply replace them with regular function calls, which are then
475 // intercepted by the run-time.
476 // Since tsan is running after everyone else, the calls should not be
477 // replaced back with intrinsics. If that becomes wrong at some point,
478 // we will need to call e.g. __tsan_memset to avoid the intrinsics.
479 bool ThreadSanitizer::instrumentMemIntrinsic(Instruction *I) {
481 if (MemSetInst *M = dyn_cast<MemSetInst>(I)) {
484 {IRB.CreatePointerCast(M->getArgOperand(0), IRB.getInt8PtrTy()),
485 IRB.CreateIntCast(M->getArgOperand(1), IRB.getInt32Ty(), false),
486 IRB.CreateIntCast(M->getArgOperand(2), IntptrTy, false)});
487 I->eraseFromParent();
488 } else if (MemTransferInst *M = dyn_cast<MemTransferInst>(I)) {
490 isa<MemCpyInst>(M) ? MemcpyFn : MemmoveFn,
491 {IRB.CreatePointerCast(M->getArgOperand(0), IRB.getInt8PtrTy()),
492 IRB.CreatePointerCast(M->getArgOperand(1), IRB.getInt8PtrTy()),
493 IRB.CreateIntCast(M->getArgOperand(2), IntptrTy, false)});
494 I->eraseFromParent();
499 // Both llvm and ThreadSanitizer atomic operations are based on C++11/C1x
500 // standards. For background see C++11 standard. A slightly older, publicly
501 // available draft of the standard (not entirely up-to-date, but close enough
502 // for casual browsing) is available here:
503 // http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2011/n3242.pdf
504 // The following page contains more background information:
505 // http://www.hpl.hp.com/personal/Hans_Boehm/c++mm/
507 bool ThreadSanitizer::instrumentAtomic(Instruction *I, const DataLayout &DL) {
509 if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
510 Value *Addr = LI->getPointerOperand();
511 int Idx = getMemoryAccessFuncIndex(Addr, DL);
514 const unsigned ByteSize = 1U << Idx;
515 const unsigned BitSize = ByteSize * 8;
516 Type *Ty = Type::getIntNTy(IRB.getContext(), BitSize);
517 Type *PtrTy = Ty->getPointerTo();
518 Value *Args[] = {IRB.CreatePointerCast(Addr, PtrTy),
519 createOrdering(&IRB, LI->getOrdering())};
520 CallInst *C = CallInst::Create(TsanAtomicLoad[Idx], Args);
521 ReplaceInstWithInst(I, C);
523 } else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
524 Value *Addr = SI->getPointerOperand();
525 int Idx = getMemoryAccessFuncIndex(Addr, DL);
528 const unsigned ByteSize = 1U << Idx;
529 const unsigned BitSize = ByteSize * 8;
530 Type *Ty = Type::getIntNTy(IRB.getContext(), BitSize);
531 Type *PtrTy = Ty->getPointerTo();
532 Value *Args[] = {IRB.CreatePointerCast(Addr, PtrTy),
533 IRB.CreateIntCast(SI->getValueOperand(), Ty, false),
534 createOrdering(&IRB, SI->getOrdering())};
535 CallInst *C = CallInst::Create(TsanAtomicStore[Idx], Args);
536 ReplaceInstWithInst(I, C);
537 } else if (AtomicRMWInst *RMWI = dyn_cast<AtomicRMWInst>(I)) {
538 Value *Addr = RMWI->getPointerOperand();
539 int Idx = getMemoryAccessFuncIndex(Addr, DL);
542 Function *F = TsanAtomicRMW[RMWI->getOperation()][Idx];
545 const unsigned ByteSize = 1U << Idx;
546 const unsigned BitSize = ByteSize * 8;
547 Type *Ty = Type::getIntNTy(IRB.getContext(), BitSize);
548 Type *PtrTy = Ty->getPointerTo();
549 Value *Args[] = {IRB.CreatePointerCast(Addr, PtrTy),
550 IRB.CreateIntCast(RMWI->getValOperand(), Ty, false),
551 createOrdering(&IRB, RMWI->getOrdering())};
552 CallInst *C = CallInst::Create(F, Args);
553 ReplaceInstWithInst(I, C);
554 } else if (AtomicCmpXchgInst *CASI = dyn_cast<AtomicCmpXchgInst>(I)) {
555 Value *Addr = CASI->getPointerOperand();
556 int Idx = getMemoryAccessFuncIndex(Addr, DL);
559 const unsigned ByteSize = 1U << Idx;
560 const unsigned BitSize = ByteSize * 8;
561 Type *Ty = Type::getIntNTy(IRB.getContext(), BitSize);
562 Type *PtrTy = Ty->getPointerTo();
563 Value *Args[] = {IRB.CreatePointerCast(Addr, PtrTy),
564 IRB.CreateIntCast(CASI->getCompareOperand(), Ty, false),
565 IRB.CreateIntCast(CASI->getNewValOperand(), Ty, false),
566 createOrdering(&IRB, CASI->getSuccessOrdering()),
567 createOrdering(&IRB, CASI->getFailureOrdering())};
568 CallInst *C = IRB.CreateCall(TsanAtomicCAS[Idx], Args);
569 Value *Success = IRB.CreateICmpEQ(C, CASI->getCompareOperand());
571 Value *Res = IRB.CreateInsertValue(UndefValue::get(CASI->getType()), C, 0);
572 Res = IRB.CreateInsertValue(Res, Success, 1);
574 I->replaceAllUsesWith(Res);
575 I->eraseFromParent();
576 } else if (FenceInst *FI = dyn_cast<FenceInst>(I)) {
577 Value *Args[] = {createOrdering(&IRB, FI->getOrdering())};
578 Function *F = FI->getSynchScope() == SingleThread ?
579 TsanAtomicSignalFence : TsanAtomicThreadFence;
580 CallInst *C = CallInst::Create(F, Args);
581 ReplaceInstWithInst(I, C);
586 int ThreadSanitizer::getMemoryAccessFuncIndex(Value *Addr,
587 const DataLayout &DL) {
588 Type *OrigPtrTy = Addr->getType();
589 Type *OrigTy = cast<PointerType>(OrigPtrTy)->getElementType();
590 assert(OrigTy->isSized());
591 uint32_t TypeSize = DL.getTypeStoreSizeInBits(OrigTy);
592 if (TypeSize != 8 && TypeSize != 16 &&
593 TypeSize != 32 && TypeSize != 64 && TypeSize != 128) {
594 NumAccessesWithBadSize++;
595 // Ignore all unusual sizes.
598 size_t Idx = countTrailingZeros(TypeSize / 8);
599 assert(Idx < kNumberOfAccessSizes);