From 24f5e55fce66d8c824aadf8dddfa256c040ea68e Mon Sep 17 00:00:00 2001 From: Evgeniy Stepanov Date: Mon, 9 Jun 2014 14:29:34 +0000 Subject: [msan] Workaround for invalid origins in shufflevector. Makes origin propagation ignore literal undef operands, and, in general, any operand we don't have origin for. https://code.google.com/p/memory-sanitizer/issues/detail?id=56 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210472 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Instrumentation/MemorySanitizer.cpp | 12 ++++++++---- .../Instrumentation/MemorySanitizer/missing_origin.ll | 19 +++++++++++++++++++ 2 files changed, 27 insertions(+), 4 deletions(-) create mode 100644 test/Instrumentation/MemorySanitizer/missing_origin.ll diff --git a/lib/Transforms/Instrumentation/MemorySanitizer.cpp b/lib/Transforms/Instrumentation/MemorySanitizer.cpp index 93b09d32e4..e890943c6a 100644 --- a/lib/Transforms/Instrumentation/MemorySanitizer.cpp +++ b/lib/Transforms/Instrumentation/MemorySanitizer.cpp @@ -1302,10 +1302,14 @@ struct MemorySanitizerVisitor : public InstVisitor { if (!Origin) { Origin = OpOrigin; } else { - Value *FlatShadow = MSV->convertToShadowTyNoVec(OpShadow, IRB); - Value *Cond = IRB.CreateICmpNE(FlatShadow, - MSV->getCleanShadow(FlatShadow)); - Origin = IRB.CreateSelect(Cond, OpOrigin, Origin); + Constant *ConstOrigin = dyn_cast(OpOrigin); + // No point in adding something that might result in 0 origin value. + if (!ConstOrigin || !ConstOrigin->isNullValue()) { + Value *FlatShadow = MSV->convertToShadowTyNoVec(OpShadow, IRB); + Value *Cond = + IRB.CreateICmpNE(FlatShadow, MSV->getCleanShadow(FlatShadow)); + Origin = IRB.CreateSelect(Cond, OpOrigin, Origin); + } } } return *this; diff --git a/test/Instrumentation/MemorySanitizer/missing_origin.ll b/test/Instrumentation/MemorySanitizer/missing_origin.ll new file mode 100644 index 0000000000..d8addce0da --- /dev/null +++ b/test/Instrumentation/MemorySanitizer/missing_origin.ll @@ -0,0 +1,19 @@ +; RUN: opt < %s -msan -msan-check-access-address=0 -msan-track-origins=1 -S | FileCheck -check-prefix=CHECK -check-prefix=CHECK %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" +target triple = "x86_64-unknown-linux-gnu" + +; Test that result origin is directy propagated from the argument, +; and is not affected by all the literal undef operands. +; https://code.google.com/p/memory-sanitizer/issues/detail?id=56 + +define <4 x i32> @Shuffle(<4 x i32> %x) nounwind uwtable sanitize_memory { +entry: + %y = shufflevector <4 x i32> %x, <4 x i32> undef, <4 x i32> + ret <4 x i32> %y +} + +; CHECK-LABEL: @Shuffle( +; CHECK: [[A:%.*]] = load i32* {{.*}}@__msan_param_origin_tls, +; CHECK: store i32 [[A]], i32* @__msan_retval_origin_tls +; CHECK: ret <4 x i32> -- cgit v1.2.3