diff --git a/llvm/lib/Transforms/Instrumentation/ThreadSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/ThreadSanitizer.cpp index 5485998164f1..0d48a350254e 100644 --- a/llvm/lib/Transforms/Instrumentation/ThreadSanitizer.cpp +++ b/llvm/lib/Transforms/Instrumentation/ThreadSanitizer.cpp @@ -80,6 +80,10 @@ static cl::opt ClCompoundReadBeforeWrite( "tsan-compound-read-before-write", cl::init(false), cl::desc("Emit special compound instrumentation for reads-before-writes"), cl::Hidden); +static cl::opt + ClOmitNonCaptured("tsan-omit-by-pointer-capturing", cl::init(true), + cl::desc("Omit accesses due to pointer capturing"), + cl::Hidden); STATISTIC(NumInstrumentedReads, "Number of instrumented reads"); STATISTIC(NumInstrumentedWrites, "Number of instrumented writes"); @@ -450,7 +454,8 @@ void ThreadSanitizer::chooseInstructionsToInstrument( const AllocaInst *AI = findAllocaForValue(Addr); // Instead of Addr, we should check whether its base pointer is captured. - if (AI && !PointerMayBeCaptured(AI, /*ReturnCaptures=*/true)) { + if (AI && !PointerMayBeCaptured(AI, /*ReturnCaptures=*/true) && + ClOmitNonCaptured) { // The variable is addressable but not captured, so it cannot be // referenced from a different thread and participate in a data race // (see llvm/Analysis/CaptureTracking.h for details). diff --git a/llvm/test/Instrumentation/ThreadSanitizer/capture-no-omit.ll b/llvm/test/Instrumentation/ThreadSanitizer/capture-no-omit.ll new file mode 100644 index 000000000000..cae04936002c --- /dev/null +++ b/llvm/test/Instrumentation/ThreadSanitizer/capture-no-omit.ll @@ -0,0 +1,92 @@ +; RUN: opt < %s -passes=tsan -tsan-omit-by-pointer-capturing=0 -S | FileCheck %s + +target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128" + +declare void @escape(ptr) + +@sink = global ptr null, align 4 + + +define void @captured2() nounwind uwtable sanitize_thread { +entry: + %ptr = alloca i32, align 4 + %tmp = alloca ptr, align 8 + ; transitive escape + store ptr %ptr, ptr %tmp, align 8 + %0 = load ptr, ptr %tmp, align 8 + store ptr %0, ptr @sink, align 8 + store i32 42, ptr %ptr, align 4 + ret void +} +; CHECK-LABEL: define void @captured2 +; CHECK: __tsan_write +; CHECK: __tsan_read +; CHECK: __tsan_write +; CHECK: __tsan_write +; CHECK: ret void + +define void @captured3() nounwind uwtable sanitize_thread { +entry: + %stkobj = alloca [2 x i32], align 8 + ; escapes due to store into global + store ptr %stkobj, ptr @sink, align 8 + ; derived is captured as its base object is captured + %derived = getelementptr inbounds i32, ptr %stkobj, i64 1 + store i32 42, ptr %derived, align 4 + ret void +} +; CHECK-LABEL: define void @captured3 +; CHECK: __tsan_write +; CHECK: __tsan_write +; CHECK: ret void + +define void @notcaptured2() nounwind uwtable sanitize_thread { +entry: + %ptr = alloca i32, align 4 + %tmp = alloca ptr, align 8 + store i32 42, ptr %ptr, align 4 + ; transitive escape + store ptr %ptr, ptr %tmp, align 8 + %0 = load ptr, ptr %tmp, align 8 + store ptr %0, ptr @sink, align 8 + ret void +} +; CHECK-LABEL: define void @notcaptured2 +; CHECK: __tsan_write +; CHECK: __tsan_write +; CHECK: __tsan_read +; CHECK: __tsan_write +; CHECK: ret void + +define void @notcaptured3(i1 %cond) nounwind uwtable sanitize_thread { +entry: + %stkobj = alloca [2 x i32], align 8 + %derived = getelementptr inbounds i32, ptr %stkobj, i64 1 + %ptr = select i1 %cond, ptr %derived, ptr %stkobj + store i32 42, ptr %ptr, align 4 + ret void +} +; CHECK-LABEL: define void @notcaptured3 +; CHECK: __tsan_write +; CHECK: ret void + +define void @notcaptured4() nounwind uwtable sanitize_thread { +entry: + %stkobj = alloca [10 x i8], align 1 + br label %loop + +exit: + ret void + +loop: + %count = phi i32 [ 0, %entry ], [ %addone, %loop ] + %derived = phi ptr [ %stkobj, %entry ], [ %ptraddone, %loop ] + store i32 %count, ptr %derived, align 4 + %ptraddone = getelementptr inbounds i32, ptr %derived, i64 1 + %addone = add nuw nsw i32 %count, 1 + %eq10 = icmp eq i32 %addone, 10 + br i1 %eq10, label %exit, label %loop +} +; CHECK-LABEL: define void @notcaptured4 +; CHECK: ret void +; CHECK: __tsan_write diff --git a/llvm/test/Instrumentation/ThreadSanitizer/capture.ll b/llvm/test/Instrumentation/ThreadSanitizer/capture.ll index e1b9e03b8844..5083c790011c 100644 --- a/llvm/test/Instrumentation/ThreadSanitizer/capture.ll +++ b/llvm/test/Instrumentation/ThreadSanitizer/capture.ll @@ -45,6 +45,7 @@ entry: ; CHECK-LABEL: define void @captured2 ; CHECK: __tsan_write ; CHECK: __tsan_write +; CHECK-NOT: __tsan_write ; CHECK: ret void define void @captured3() nounwind uwtable sanitize_thread { @@ -101,6 +102,7 @@ entry: ; CHECK-LABEL: define void @notcaptured2 ; CHECK: __tsan_write ; CHECK: __tsan_write +; CHECK-NOT: __tsan_write ; CHECK: ret void define void @notcaptured3(i1 %cond) nounwind uwtable sanitize_thread {