[C++11] Add 'override' keyword to virtual methods that override their base class.
[oota-llvm.git] / lib / Transforms / Instrumentation / ThreadSanitizer.cpp
index 55a53819622939adefd177d8102acb5c2a9f9580..bc022600cbefae90dbc773e30b4fa443d870d0a2 100644 (file)
 
 #define DEBUG_TYPE "tsan"
 
-#include "BlackList.h"
-#include "llvm/Function.h"
-#include "llvm/IRBuilder.h"
-#include "llvm/Intrinsics.h"
-#include "llvm/LLVMContext.h"
-#include "llvm/Metadata.h"
-#include "llvm/Module.h"
-#include "llvm/Type.h"
+#include "llvm/Transforms/Instrumentation.h"
 #include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/ADT/StringExtras.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/Intrinsics.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Metadata.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IR/Type.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Support/raw_ostream.h"
-#include "llvm/DataLayout.h"
-#include "llvm/Transforms/Instrumentation.h"
 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
 #include "llvm/Transforms/Utils/ModuleUtils.h"
+#include "llvm/Transforms/Utils/SpecialCaseList.h"
 
 using namespace llvm;
 
-static cl::opt<std::string>  ClBlackListFile("tsan-blacklist",
+static cl::opt<std::string>  ClBlacklistFile("tsan-blacklist",
        cl::desc("Blacklist file"), cl::Hidden);
 static cl::opt<bool>  ClInstrumentMemoryAccesses(
     "tsan-instrument-memory-accesses", cl::init(true),
@@ -56,6 +57,9 @@ static cl::opt<bool>  ClInstrumentFuncEntryExit(
 static cl::opt<bool>  ClInstrumentAtomics(
     "tsan-instrument-atomics", cl::init(true),
     cl::desc("Instrument atomics"), cl::Hidden);
+static cl::opt<bool>  ClInstrumentMemIntrinsics(
+    "tsan-instrument-memintrinsics", cl::init(true),
+    cl::desc("Instrument memintrinsics (memset/memcpy/memmove)"), cl::Hidden);
 
 STATISTIC(NumInstrumentedReads, "Number of instrumented reads");
 STATISTIC(NumInstrumentedWrites, "Number of instrumented writes");
@@ -63,6 +67,7 @@ STATISTIC(NumOmittedReadsBeforeWrite,
           "Number of reads ignored due to following writes");
 STATISTIC(NumAccessesWithBadSize, "Number of accesses with bad size");
 STATISTIC(NumInstrumentedVtableWrites, "Number of vtable ptr writes");
+STATISTIC(NumInstrumentedVtableReads, "Number of vtable ptr reads");
 STATISTIC(NumOmittedReadsFromConstantGlobals,
           "Number of reads from constant globals");
 STATISTIC(NumOmittedReadsFromVtable, "Number of vtable reads");
@@ -71,22 +76,30 @@ namespace {
 
 /// ThreadSanitizer: instrument the code in module to find races.
 struct ThreadSanitizer : public FunctionPass {
-  ThreadSanitizer();
-  const char *getPassName() const;
-  bool runOnFunction(Function &F);
-  bool doInitialization(Module &M);
+  ThreadSanitizer(StringRef BlacklistFile = StringRef())
+      : FunctionPass(ID),
+        DL(0),
+        BlacklistFile(BlacklistFile.empty() ? ClBlacklistFile
+                                            : BlacklistFile) { }
+  const char *getPassName() const override;
+  bool runOnFunction(Function &F) override;
+  bool doInitialization(Module &M) override;
   static char ID;  // Pass identification, replacement for typeid.
 
  private:
+  void initializeCallbacks(Module &M);
   bool instrumentLoadOrStore(Instruction *I);
   bool instrumentAtomic(Instruction *I);
+  bool instrumentMemIntrinsic(Instruction *I);
   void chooseInstructionsToInstrument(SmallVectorImpl<Instruction*> &Local,
                                       SmallVectorImpl<Instruction*> &All);
   bool addrPointsToConstantData(Value *Addr);
   int getMemoryAccessFuncIndex(Value *Addr);
 
-  DataLayout *TD;
-  OwningPtr<BlackList> BL;
+  const DataLayout *DL;
+  Type *IntptrTy;
+  SmallString<64> BlacklistFile;
+  OwningPtr<SpecialCaseList> BL;
   IntegerType *OrdTy;
   // Callbacks to run-time library are computed in doInitialization.
   Function *TsanFuncEntry;
@@ -102,6 +115,8 @@ struct ThreadSanitizer : public FunctionPass {
   Function *TsanAtomicThreadFence;
   Function *TsanAtomicSignalFence;
   Function *TsanVptrUpdate;
+  Function *TsanVptrLoad;
+  Function *MemmoveFn, *MemcpyFn, *MemsetFn;
 };
 }  // namespace
 
@@ -114,13 +129,8 @@ const char *ThreadSanitizer::getPassName() const {
   return "ThreadSanitizer";
 }
 
-ThreadSanitizer::ThreadSanitizer()
-  : FunctionPass(ID),
-  TD(NULL) {
-}
-
-FunctionPass *llvm::createThreadSanitizerPass() {
-  return new ThreadSanitizer();
+FunctionPass *llvm::createThreadSanitizerPass(StringRef BlacklistFile) {
+  return new ThreadSanitizer(BlacklistFile);
 }
 
 static Function *checkInterfaceFunction(Constant *FuncOrBitcast) {
@@ -130,18 +140,8 @@ static Function *checkInterfaceFunction(Constant *FuncOrBitcast) {
   report_fatal_error("ThreadSanitizer interface function redefined");
 }
 
-bool ThreadSanitizer::doInitialization(Module &M) {
-  TD = getAnalysisIfAvailable<DataLayout>();
-  if (!TD)
-    return false;
-  BL.reset(new BlackList(ClBlackListFile));
-
-  // Always insert a call to __tsan_init into the module's CTORs.
+void ThreadSanitizer::initializeCallbacks(Module &M) {
   IRBuilder<> IRB(M.getContext());
-  Value *TsanInit = M.getOrInsertFunction("__tsan_init",
-                                          IRB.getVoidTy(), NULL);
-  appendToGlobalCtors(M, cast<Function>(TsanInit), 0);
-
   // Initialize the callbacks.
   TsanFuncEntry = checkInterfaceFunction(M.getOrInsertFunction(
       "__tsan_func_entry", IRB.getVoidTy(), IRB.getInt8PtrTy(), NULL));
@@ -188,6 +188,8 @@ bool ThreadSanitizer::doInitialization(Module &M) {
         NamePart = "_fetch_or";
       else if (op == AtomicRMWInst::Xor)
         NamePart = "_fetch_xor";
+      else if (op == AtomicRMWInst::Nand)
+        NamePart = "_fetch_nand";
       else
         continue;
       SmallString<32> RMWName("__tsan_atomic" + itostr(BitSize) + NamePart);
@@ -203,20 +205,44 @@ bool ThreadSanitizer::doInitialization(Module &M) {
   TsanVptrUpdate = checkInterfaceFunction(M.getOrInsertFunction(
       "__tsan_vptr_update", IRB.getVoidTy(), IRB.getInt8PtrTy(),
       IRB.getInt8PtrTy(), NULL));
+  TsanVptrLoad = checkInterfaceFunction(M.getOrInsertFunction(
+      "__tsan_vptr_read", IRB.getVoidTy(), IRB.getInt8PtrTy(), NULL));
   TsanAtomicThreadFence = checkInterfaceFunction(M.getOrInsertFunction(
       "__tsan_atomic_thread_fence", IRB.getVoidTy(), OrdTy, NULL));
   TsanAtomicSignalFence = checkInterfaceFunction(M.getOrInsertFunction(
       "__tsan_atomic_signal_fence", IRB.getVoidTy(), OrdTy, NULL));
+
+  MemmoveFn = checkInterfaceFunction(M.getOrInsertFunction(
+    "memmove", IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
+    IRB.getInt8PtrTy(), IntptrTy, NULL));
+  MemcpyFn = checkInterfaceFunction(M.getOrInsertFunction(
+    "memcpy", IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
+    IntptrTy, NULL));
+  MemsetFn = checkInterfaceFunction(M.getOrInsertFunction(
+    "memset", IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), IRB.getInt32Ty(),
+    IntptrTy, NULL));
+}
+
+bool ThreadSanitizer::doInitialization(Module &M) {
+  DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>();
+  if (!DLP)
+    return false;
+  DL = &DLP->getDataLayout();
+  BL.reset(SpecialCaseList::createOrDie(BlacklistFile));
+
+  // Always insert a call to __tsan_init into the module's CTORs.
+  IRBuilder<> IRB(M.getContext());
+  IntptrTy = IRB.getIntPtrTy(DL);
+  Value *TsanInit = M.getOrInsertFunction("__tsan_init",
+                                          IRB.getVoidTy(), NULL);
+  appendToGlobalCtors(M, cast<Function>(TsanInit), 0);
+
   return true;
 }
 
 static bool isVtableAccess(Instruction *I) {
-  if (MDNode *Tag = I->getMetadata(LLVMContext::MD_tbaa)) {
-    if (Tag->getNumOperands() < 1) return false;
-    if (MDString *Tag1 = dyn_cast<MDString>(Tag->getOperand(0))) {
-      if (Tag1->getString() == "vtable pointer") return true;
-    }
-  }
+  if (MDNode *Tag = I->getMetadata(LLVMContext::MD_tbaa))
+    return Tag->isTBAAVtableAccess();
   return false;
 }
 
@@ -295,12 +321,14 @@ static bool isAtomic(Instruction *I) {
 }
 
 bool ThreadSanitizer::runOnFunction(Function &F) {
-  if (!TD) return false;
+  if (!DL) return false;
   if (BL->isIn(F)) return false;
+  initializeCallbacks(*F.getParent());
   SmallVector<Instruction*, 8> RetVec;
   SmallVector<Instruction*, 8> AllLoadsAndStores;
   SmallVector<Instruction*, 8> LocalLoadsAndStores;
   SmallVector<Instruction*, 8> AtomicAccesses;
+  SmallVector<Instruction*, 8> MemIntrinCalls;
   bool Res = false;
   bool HasCalls = false;
 
@@ -317,6 +345,8 @@ bool ThreadSanitizer::runOnFunction(Function &F) {
       else if (isa<ReturnInst>(BI))
         RetVec.push_back(BI);
       else if (isa<CallInst>(BI) || isa<InvokeInst>(BI)) {
+        if (isa<MemIntrinsic>(BI))
+          MemIntrinCalls.push_back(BI);
         HasCalls = true;
         chooseInstructionsToInstrument(LocalLoadsAndStores, AllLoadsAndStores);
       }
@@ -329,7 +359,7 @@ bool ThreadSanitizer::runOnFunction(Function &F) {
   // (e.g. variables that do not escape, etc).
 
   // Instrument memory accesses.
-  if (ClInstrumentMemoryAccesses)
+  if (ClInstrumentMemoryAccesses && F.hasFnAttribute(Attribute::SanitizeThread))
     for (size_t i = 0, n = AllLoadsAndStores.size(); i < n; ++i) {
       Res |= instrumentLoadOrStore(AllLoadsAndStores[i]);
     }
@@ -340,6 +370,11 @@ bool ThreadSanitizer::runOnFunction(Function &F) {
       Res |= instrumentAtomic(AtomicAccesses[i]);
     }
 
+  if (ClInstrumentMemIntrinsics)
+    for (size_t i = 0, n = MemIntrinCalls.size(); i < n; ++i) {
+      Res |= instrumentMemIntrinsic(MemIntrinCalls[i]);
+    }
+
   // Instrument function entry/exit points if there were instrumented accesses.
   if ((Res || HasCalls) && ClInstrumentFuncEntryExit) {
     IRBuilder<> IRB(F.getEntryBlock().getFirstNonPHI());
@@ -368,8 +403,13 @@ bool ThreadSanitizer::instrumentLoadOrStore(Instruction *I) {
   if (IsWrite && isVtableAccess(I)) {
     DEBUG(dbgs() << "  VPTR : " << *I << "\n");
     Value *StoredValue = cast<StoreInst>(I)->getValueOperand();
-    // StoredValue does not necessary have a pointer type.
-    if (isa<IntegerType>(StoredValue->getType()))
+    // StoredValue may be a vector type if we are storing several vptrs at once.
+    // In this case, just take the first element of the vector since this is
+    // enough to find vptr races.
+    if (isa<VectorType>(StoredValue->getType()))
+      StoredValue = IRB.CreateExtractElement(
+          StoredValue, ConstantInt::get(IRB.getInt32Ty(), 0));
+    if (StoredValue->getType()->isIntegerTy())
       StoredValue = IRB.CreateIntToPtr(StoredValue, IRB.getInt8PtrTy());
     // Call TsanVptrUpdate.
     IRB.CreateCall2(TsanVptrUpdate,
@@ -378,6 +418,12 @@ bool ThreadSanitizer::instrumentLoadOrStore(Instruction *I) {
     NumInstrumentedVtableWrites++;
     return true;
   }
+  if (!IsWrite && isVtableAccess(I)) {
+    IRB.CreateCall(TsanVptrLoad,
+                   IRB.CreatePointerCast(Addr, IRB.getInt8PtrTy()));
+    NumInstrumentedVtableReads++;
+    return true;
+  }
   Value *OnAccessFunc = IsWrite ? TsanWrite[Idx] : TsanRead[Idx];
   IRB.CreateCall(OnAccessFunc, IRB.CreatePointerCast(Addr, IRB.getInt8PtrTy()));
   if (IsWrite) NumInstrumentedWrites++;
@@ -415,11 +461,37 @@ static ConstantInt *createFailOrdering(IRBuilder<> *IRB, AtomicOrdering ord) {
   return IRB->getInt32(v);
 }
 
+// If a memset intrinsic gets inlined by the code gen, we will miss races on it.
+// So, we either need to ensure the intrinsic is not inlined, or instrument it.
+// We do not instrument memset/memmove/memcpy intrinsics (too complicated),
+// instead we simply replace them with regular function calls, which are then
+// intercepted by the run-time.
+// Since tsan is running after everyone else, the calls should not be
+// replaced back with intrinsics. If that becomes wrong at some point,
+// we will need to call e.g. __tsan_memset to avoid the intrinsics.
+bool ThreadSanitizer::instrumentMemIntrinsic(Instruction *I) {
+  IRBuilder<> IRB(I);
+  if (MemSetInst *M = dyn_cast<MemSetInst>(I)) {
+    IRB.CreateCall3(MemsetFn,
+      IRB.CreatePointerCast(M->getArgOperand(0), IRB.getInt8PtrTy()),
+      IRB.CreateIntCast(M->getArgOperand(1), IRB.getInt32Ty(), false),
+      IRB.CreateIntCast(M->getArgOperand(2), IntptrTy, false));
+    I->eraseFromParent();
+  } else if (MemTransferInst *M = dyn_cast<MemTransferInst>(I)) {
+    IRB.CreateCall3(isa<MemCpyInst>(M) ? MemcpyFn : MemmoveFn,
+      IRB.CreatePointerCast(M->getArgOperand(0), IRB.getInt8PtrTy()),
+      IRB.CreatePointerCast(M->getArgOperand(1), IRB.getInt8PtrTy()),
+      IRB.CreateIntCast(M->getArgOperand(2), IntptrTy, false));
+    I->eraseFromParent();
+  }
+  return false;
+}
+
 // Both llvm and ThreadSanitizer atomic operations are based on C++11/C1x
-// standards.  For background see C++11 standard.  A slightly older, publically
+// standards.  For background see C++11 standard.  A slightly older, publicly
 // available draft of the standard (not entirely up-to-date, but close enough
 // for casual browsing) is available here:
-// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2011/n3242.pdf\
+// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2011/n3242.pdf
 // The following page contains more background information:
 // http://www.hpl.hp.com/personal/Hans_Boehm/c++mm/
 
@@ -502,14 +574,14 @@ int ThreadSanitizer::getMemoryAccessFuncIndex(Value *Addr) {
   Type *OrigPtrTy = Addr->getType();
   Type *OrigTy = cast<PointerType>(OrigPtrTy)->getElementType();
   assert(OrigTy->isSized());
-  uint32_t TypeSize = TD->getTypeStoreSizeInBits(OrigTy);
+  uint32_t TypeSize = DL->getTypeStoreSizeInBits(OrigTy);
   if (TypeSize != 8  && TypeSize != 16 &&
       TypeSize != 32 && TypeSize != 64 && TypeSize != 128) {
     NumAccessesWithBadSize++;
     // Ignore all unusual sizes.
     return -1;
   }
-  size_t Idx = CountTrailingZeros_32(TypeSize / 8);
+  size_t Idx = countTrailingZeros(TypeSize / 8);
   assert(Idx < kNumberOfAccessSizes);
   return Idx;
 }