diff --git a/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp --- a/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp +++ b/llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp @@ -186,6 +186,13 @@ "labels to 16."), cl::Hidden, cl::init(false)); +// Controls whether the pass tracks the control flow of select instructions. +static cl::opt ClTrackSelectControlFlow( + "dfsan-track-select-control-flow", + cl::desc("Propagate labels from condition values of select instructions " + "to results."), + cl::Hidden, cl::init(true)); + static StringRef GetGlobalTypeString(const GlobalValue &G) { // Types of GlobalVariables are always pointer types. Type *GType = G.getValueType(); @@ -1541,22 +1548,21 @@ Value *CondShadow = DFSF.getShadow(I.getCondition()); Value *TrueShadow = DFSF.getShadow(I.getTrueValue()); Value *FalseShadow = DFSF.getShadow(I.getFalseValue()); + Value *ShadowSel = nullptr; if (isa(I.getCondition()->getType())) { - DFSF.setShadow( - &I, - DFSF.combineShadows( - CondShadow, DFSF.combineShadows(TrueShadow, FalseShadow, &I), &I)); + ShadowSel = DFSF.combineShadows(TrueShadow, FalseShadow, &I); } else { - Value *ShadowSel; if (TrueShadow == FalseShadow) { ShadowSel = TrueShadow; } else { ShadowSel = SelectInst::Create(I.getCondition(), TrueShadow, FalseShadow, "", &I); } - DFSF.setShadow(&I, DFSF.combineShadows(CondShadow, ShadowSel, &I)); } + DFSF.setShadow(&I, ClTrackSelectControlFlow + ? DFSF.combineShadows(CondShadow, ShadowSel, &I) + : ShadowSel); } void DFSanVisitor::visitMemSetInst(MemSetInst &I) { diff --git a/llvm/test/Instrumentation/DataFlowSanitizer/select.ll b/llvm/test/Instrumentation/DataFlowSanitizer/select.ll new file mode 100644 --- /dev/null +++ b/llvm/test/Instrumentation/DataFlowSanitizer/select.ll @@ -0,0 +1,72 @@ +; RUN: opt < %s -dfsan -dfsan-track-select-control-flow=1 -S | FileCheck %s --check-prefix=TRACK_CONTROL_FLOW +; RUN: opt < %s -dfsan -dfsan-track-select-control-flow=0 -S | FileCheck %s --check-prefix=NO_TRACK_CONTROL_FLOW +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" +target triple = "x86_64-unknown-linux-gnu" + +define i8 @select8(i1 %c, i8 %t, i8 %f) { + ; TRACK_CONTROL_FLOW: %1 = load i16, i16* getelementptr inbounds ([64 x i16], [64 x i16]* @__dfsan_arg_tls, i64 0, i64 2) + ; TRACK_CONTROL_FLOW: %2 = load i16, i16* getelementptr inbounds ([64 x i16], [64 x i16]* @__dfsan_arg_tls, i64 0, i64 1) + ; TRACK_CONTROL_FLOW: %3 = load i16, i16* getelementptr inbounds ([64 x i16], [64 x i16]* @__dfsan_arg_tls, i64 0, i64 0) + ; TRACK_CONTROL_FLOW: %4 = select i1 %c, i16 %2, i16 %1 + ; TRACK_CONTROL_FLOW: %5 = icmp ne i16 %3, %4 + ; TRACK_CONTROL_FLOW: %7 = call {{.*}} i16 @__dfsan_union(i16 {{.*}} %3, i16 {{.*}} %4) + ; TRACK_CONTROL_FLOW: %9 = phi i16 [ %7, {{.*}} ], [ %3, {{.*}} ] + ; TRACK_CONTROL_FLOW: %a = select i1 %c, i8 %t, i8 %f + ; TRACK_CONTROL_FLOW: store i16 %9, i16* @__dfsan_retval_tls + ; TRACK_CONTROL_FLOW: ret i8 %a + + ; NO_TRACK_CONTROL_FLOW: %1 = load i16, i16* getelementptr inbounds ([64 x i16], [64 x i16]* @__dfsan_arg_tls, i64 0, i64 2) + ; NO_TRACK_CONTROL_FLOW: %2 = load i16, i16* getelementptr inbounds ([64 x i16], [64 x i16]* @__dfsan_arg_tls, i64 0, i64 1) + ; NO_TRACK_CONTROL_FLOW: %3 = load i16, i16* getelementptr inbounds ([64 x i16], [64 x i16]* @__dfsan_arg_tls, i64 0, i64 0) + ; NO_TRACK_CONTROL_FLOW: %4 = select i1 %c, i16 %2, i16 %1 + ; NO_TRACK_CONTROL_FLOW: %a = select i1 %c, i8 %t, i8 %f + ; NO_TRACK_CONTROL_FLOW: store i16 %4, i16* @__dfsan_retval_tls + ; NO_TRACK_CONTROL_FLOW: ret i8 %a + + %a = select i1 %c, i8 %t, i8 %f + ret i8 %a +} + +define i8 @select8e(i1 %c, i8 %tf) { + ; TRACK_CONTROL_FLOW: %1 = load i16, i16* getelementptr inbounds ([64 x i16], [64 x i16]* @__dfsan_arg_tls, i64 0, i64 1) + ; TRACK_CONTROL_FLOW: %2 = load i16, i16* getelementptr inbounds ([64 x i16], [64 x i16]* @__dfsan_arg_tls, i64 0, i64 0) + ; TRACK_CONTROL_FLOW: %3 = icmp ne i16 %2, %1 + ; TRACK_CONTROL_FLOW: %5 = call {{.*}} i16 @__dfsan_union(i16 {{.*}} %2, i16 {{.*}} %1) + ; TRACK_CONTROL_FLOW: %7 = phi i16 [ %5, {{.*}} ], [ %2, {{.*}} ] + ; TRACK_CONTROL_FLOW: %a = select i1 %c, i8 %tf, i8 %tf + ; TRACK_CONTROL_FLOW: store i16 %7, i16* @__dfsan_retval_tls + ; TRACK_CONTROL_FLOW: ret i8 %a + + ; NO_TRACK_CONTROL_FLOW: %1 = load i16, i16* getelementptr inbounds ([64 x i16], [64 x i16]* @__dfsan_arg_tls, i64 0, i64 1) + ; NO_TRACK_CONTROL_FLOW: %2 = load i16, i16* getelementptr inbounds ([64 x i16], [64 x i16]* @__dfsan_arg_tls, i64 0, i64 0) + ; NO_TRACK_CONTROL_FLOW: %a = select i1 %c, i8 %tf, i8 %tf + ; NO_TRACK_CONTROL_FLOW: store i16 %1, i16* @__dfsan_retval_tls + ; NO_TRACK_CONTROL_FLOW: ret i8 %a + + %a = select i1 %c, i8 %tf, i8 %tf + ret i8 %a +} + +define <4 x i8> @select8v(i1 %c, <4 x i8> %t, <4 x i8> %f) { + ; TRACK_CONTROL_FLOW: %1 = load i16, i16* getelementptr inbounds ([64 x i16], [64 x i16]* @__dfsan_arg_tls, i64 0, i64 2) + ; TRACK_CONTROL_FLOW: %2 = load i16, i16* getelementptr inbounds ([64 x i16], [64 x i16]* @__dfsan_arg_tls, i64 0, i64 1) + ; TRACK_CONTROL_FLOW: %3 = load i16, i16* getelementptr inbounds ([64 x i16], [64 x i16]* @__dfsan_arg_tls, i64 0, i64 0) + ; TRACK_CONTROL_FLOW: %4 = select i1 %c, i16 %2, i16 %1 + ; TRACK_CONTROL_FLOW: %5 = icmp ne i16 %3, %4 + ; TRACK_CONTROL_FLOW: %7 = call {{.*}} i16 @__dfsan_union(i16 {{.*}} %3, i16 {{.*}} %4) + ; TRACK_CONTROL_FLOW: %9 = phi i16 [ %7, {{.*}} ], [ %3, {{.*}} ] + ; TRACK_CONTROL_FLOW: %a = select i1 %c, <4 x i8> %t, <4 x i8> %f + ; TRACK_CONTROL_FLOW: store i16 %9, i16* @__dfsan_retval_tls + ; TRACK_CONTROL_FLOW: ret <4 x i8> %a + + ; NO_TRACK_CONTROL_FLOW: %1 = load i16, i16* getelementptr inbounds ([64 x i16], [64 x i16]* @__dfsan_arg_tls, i64 0, i64 2) + ; NO_TRACK_CONTROL_FLOW: %2 = load i16, i16* getelementptr inbounds ([64 x i16], [64 x i16]* @__dfsan_arg_tls, i64 0, i64 1) + ; NO_TRACK_CONTROL_FLOW: %3 = load i16, i16* getelementptr inbounds ([64 x i16], [64 x i16]* @__dfsan_arg_tls, i64 0, i64 0) + ; NO_TRACK_CONTROL_FLOW: %4 = select i1 %c, i16 %2, i16 %1 + ; NO_TRACK_CONTROL_FLOW: %a = select i1 %c, <4 x i8> %t, <4 x i8> %f + ; NO_TRACK_CONTROL_FLOW: store i16 %4, i16* @__dfsan_retval_tls + ; NO_TRACK_CONTROL_FLOW: ret <4 x i8> %a + + %a = select i1 %c, <4 x i8> %t, <4 x i8> %f + ret <4 x i8> %a +} \ No newline at end of file