diff --git a/lib/Transforms/Instrumentation/MemorySanitizer.cpp b/lib/Transforms/Instrumentation/MemorySanitizer.cpp index a78213de7b3..ae73a2e9c9e 100644 --- a/lib/Transforms/Instrumentation/MemorySanitizer.cpp +++ b/lib/Transforms/Instrumentation/MemorySanitizer.cpp @@ -1970,8 +1970,7 @@ struct VarArgAMD64Helper : public VarArgHelper { Value *OverflowArgAreaPtr = IRB.CreateLoad(OverflowArgAreaPtrPtr); Value *OverflowArgAreaShadowPtr = MSV.getShadowPtr(OverflowArgAreaPtr, IRB.getInt8Ty(), IRB); - Value *SrcPtr = - getShadowPtrForVAArgument(VAArgTLSCopy, IRB, AMD64FpEndOffset); + Value *SrcPtr = IRB.CreateConstGEP1_32(VAArgTLSCopy, AMD64FpEndOffset); IRB.CreateMemCpy(OverflowArgAreaShadowPtr, SrcPtr, VAArgOverflowSize, 16); } } diff --git a/test/Instrumentation/MemorySanitizer/msan_basic.ll b/test/Instrumentation/MemorySanitizer/msan_basic.ll index 4fa031924f5..345b070b538 100644 --- a/test/Instrumentation/MemorySanitizer/msan_basic.ll +++ b/test/Instrumentation/MemorySanitizer/msan_basic.ll @@ -597,6 +597,31 @@ define void @VACopy(i8* %p1, i8* %p2) nounwind uwtable sanitize_memory { ; CHECK: ret void +; Test that va_start instrumentation does not use va_arg_tls*. +; It should work with a local stack copy instead. + +%struct.__va_list_tag = type { i32, i32, i8*, i8* } +declare void @llvm.va_start(i8*) nounwind + +; Function Attrs: nounwind uwtable +define void @VAStart(i32 %x, ...) { +entry: + %x.addr = alloca i32, align 4 + %va = alloca [1 x %struct.__va_list_tag], align 16 + store i32 %x, i32* %x.addr, align 4 + %arraydecay = getelementptr inbounds [1 x %struct.__va_list_tag]* %va, i32 0, i32 0 + %arraydecay1 = bitcast %struct.__va_list_tag* %arraydecay to i8* + call void @llvm.va_start(i8* %arraydecay1) + ret void +} + +; CHECK: @VAStart +; CHECK: call void @llvm.va_start +; CHECK-NOT: @__msan_va_arg_tls +; CHECK-NOT: @__msan_va_arg_overflow_size_tls +; CHECK: ret void + + ; Test handling of volatile stores. ; Check that MemorySanitizer does not add a check of the value being stored.