[llvm] r206746 - [asan] instead of inserting inline instrumentation around memset/memcpy/memmove, replace the intrinsic with __asan_memset/etc. This makes the memset/etc handling more complete and consistent with what we do in msan. It may slowdown some cases (when the intrinsic was actually inlined) and speedup other cases (when it was not inlined)

[Kostya Serebryany]

Author: kcc
Date: Mon Apr 21 06:50:42 2014
New Revision: 206746

URL: http://llvm.org/viewvc/llvm-project?rev=206746&view=rev
Log:
[asan] instead of inserting inline instrumentation around memset/memcpy/memmove, replace the intrinsic with __asan_memset/etc. This makes the memset/etc handling more complete and consistent with what we do in msan. It may slowdown some cases (when the intrinsic was actually inlined) and speedup other cases (when it was not inlined)

Modified:
    llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp

Modified: llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp?rev=206746&r1=206745&r2=206746&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp (original)
+++ llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp Mon Apr 21 06:50:42 2014
@@ -141,8 +141,6 @@ static cl::opt<int> ClCoverageBlockThres
        cl::Hidden, cl::init(1500));
 static cl::opt<bool> ClInitializers("asan-initialization-order",
        cl::desc("Handle C++ initializer order"), cl::Hidden, cl::init(false));
-static cl::opt<bool> ClMemIntrin("asan-memintrin",
-       cl::desc("Handle memset/memcpy/memmove"), cl::Hidden, cl::init(true));
 static cl::opt<bool> ClInvalidPointerPairs("asan-detect-invalid-pointer-pair",
        cl::desc("Instrument <, <=, >, >=, - with pointer operands"),
        cl::Hidden, cl::init(false));
@@ -327,7 +325,7 @@ struct AddressSanitizer : public Functio
   Instruction *generateCrashCode(Instruction *InsertBefore, Value *Addr,
                                  bool IsWrite, size_t AccessSizeIndex,
                                  Value *SizeArgument);
-  bool instrumentMemIntrinsic(MemIntrinsic *MI, bool UseCalls);
+  void instrumentMemIntrinsic(MemIntrinsic *MI);
   void instrumentMemIntrinsicParam(Instruction *OrigIns, Value *Addr,
                                    Value *Size, Instruction *InsertBefore,
                                    bool IsWrite, bool UseCalls);
@@ -367,6 +365,7 @@ struct AddressSanitizer : public Functio
   // This array is indexed by AccessIsWrite.
   Function *AsanErrorCallbackSized[2],
            *AsanMemoryAccessCallbackSized[2];
+  Function *AsanMemmove, *AsanMemcpy, *AsanMemset;
   InlineAsm *EmptyAsm;
   SetOfDynamicallyInitializedGlobals DynamicallyInitializedGlobals;
 
@@ -623,29 +622,24 @@ void AddressSanitizer::instrumentMemIntr
 }
 
 // Instrument memset/memmove/memcpy
-bool AddressSanitizer::instrumentMemIntrinsic(MemIntrinsic *MI, bool UseCalls) {
-  Value *Dst = MI->getDest();
-  MemTransferInst *MemTran = dyn_cast<MemTransferInst>(MI);
-  Value *Src = MemTran ? MemTran->getSource() : 0;
-  Value *Length = MI->getLength();
-
-  Constant *ConstLength = dyn_cast<Constant>(Length);
-  Instruction *InsertBefore = MI;
-  if (ConstLength) {
-    if (ConstLength->isNullValue()) return false;
-  } else {
-    // The size is not a constant so it could be zero -- check at run-time.
-    IRBuilder<> IRB(InsertBefore);
-
-    Value *Cmp = IRB.CreateICmpNE(Length,
-                                  Constant::getNullValue(Length->getType()));
-    InsertBefore = SplitBlockAndInsertIfThen(Cmp, InsertBefore, false);
+void AddressSanitizer::instrumentMemIntrinsic(MemIntrinsic *MI) {
+  IRBuilder<> IRB(MI);
+  Instruction *Call = 0;
+  if (isa<MemTransferInst>(MI)) {
+    Call = IRB.CreateCall3(
+        isa<MemMoveInst>(MI) ? AsanMemmove : AsanMemcpy,
+        IRB.CreatePointerCast(MI->getOperand(0), IRB.getInt8PtrTy()),
+        IRB.CreatePointerCast(MI->getOperand(1), IRB.getInt8PtrTy()),
+        IRB.CreateIntCast(MI->getOperand(2), IntptrTy, false));
+  } else if (isa<MemSetInst>(MI)) {
+    Call = IRB.CreateCall3(
+        AsanMemset,
+        IRB.CreatePointerCast(MI->getOperand(0), IRB.getInt8PtrTy()),
+        IRB.CreateIntCast(MI->getOperand(1), IRB.getInt32Ty(), false),
+        IRB.CreateIntCast(MI->getOperand(2), IntptrTy, false));
   }
-
-  instrumentMemIntrinsicParam(MI, Dst, Length, InsertBefore, true, UseCalls);
-  if (Src)
-    instrumentMemIntrinsicParam(MI, Src, Length, InsertBefore, false, UseCalls);
-  return true;
+  Call->setDebugLoc(MI->getDebugLoc());
+  MI->eraseFromParent();
 }
 
 // If I is an interesting memory access, return the PointerOperand
@@ -1156,8 +1150,18 @@ void AddressSanitizer::initializeCallbac
       M.getOrInsertFunction(ClMemoryAccessCallbackPrefix + "storeN",
                             IRB.getVoidTy(), IntptrTy, IntptrTy, NULL));
 
-  AsanHandleNoReturnFunc = checkInterfaceFunction(M.getOrInsertFunction(
-      kAsanHandleNoReturnName, IRB.getVoidTy(), NULL));
+  AsanMemmove = checkInterfaceFunction(M.getOrInsertFunction(
+      ClMemoryAccessCallbackPrefix + "memmove", IRB.getInt8PtrTy(),
+      IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), IntptrTy, NULL));
+  AsanMemcpy = checkInterfaceFunction(M.getOrInsertFunction(
+      ClMemoryAccessCallbackPrefix + "memcpy", IRB.getInt8PtrTy(),
+      IRB.getInt8PtrTy(), IRB.getInt8PtrTy(), IntptrTy, NULL));
+  AsanMemset = checkInterfaceFunction(M.getOrInsertFunction(
+      ClMemoryAccessCallbackPrefix + "memset", IRB.getInt8PtrTy(),
+      IRB.getInt8PtrTy(), IRB.getInt32Ty(), IntptrTy, NULL));
+
+  AsanHandleNoReturnFunc = checkInterfaceFunction(
+      M.getOrInsertFunction(kAsanHandleNoReturnName, IRB.getVoidTy(), NULL));
   AsanCovFunction = checkInterfaceFunction(M.getOrInsertFunction(
       kAsanCovName, IRB.getVoidTy(), NULL));
   AsanPtrCmpFunction = checkInterfaceFunction(M.getOrInsertFunction(
@@ -1328,7 +1332,7 @@ bool AddressSanitizer::runOnFunction(Fun
                  isInterestingPointerComparisonOrSubtraction(BI)) {
         PointerComparisonsOrSubtracts.push_back(BI);
         continue;
-      } else if (isa<MemIntrinsic>(BI) && ClMemIntrin) {
+      } else if (isa<MemIntrinsic>(BI)) {
         // ok, take it.
       } else {
         if (isa<AllocaInst>(BI))
@@ -1374,7 +1378,7 @@ bool AddressSanitizer::runOnFunction(Fun
       if (isInterestingMemoryAccess(Inst, &IsWrite))
         instrumentMop(Inst, UseCalls);
       else
-        instrumentMemIntrinsic(cast<MemIntrinsic>(Inst), UseCalls);
+        instrumentMemIntrinsic(cast<MemIntrinsic>(Inst));
     }
     NumInstrumented++;
   }