From: Evgeniy Stepanov <eugeni.stepanov@gmail.com>
Date: Fri, 6 Feb 2015 21:47:39 +0000 (+0000)
Subject: [msan] Fix "missing origin" in atomic store.
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=e9f5367fed0c8f64610ba5188b5885c9ccb5902d;p=oota-llvm.git

[msan] Fix "missing origin" in atomic store.

An atomic store always make the target location fully initialized (in the
current implementation). It should not store origin. Initialized memory can't
have meaningful origin, and, due to origin granularity (4 bytes) there is a
chance that this extra store would overwrite meaningfull origin for an adjacent
location.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228444 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Transforms/Instrumentation/MemorySanitizer.cpp b/lib/Transforms/Instrumentation/MemorySanitizer.cpp
index 4109bfdc304..b475234a4a2 100644
--- a/lib/Transforms/Instrumentation/MemorySanitizer.cpp
+++ b/lib/Transforms/Instrumentation/MemorySanitizer.cpp
@@ -702,7 +702,7 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
 
       if (SI.isAtomic()) SI.setOrdering(addReleaseOrdering(SI.getOrdering()));
 
-      if (MS.TrackOrigins)
+      if (MS.TrackOrigins && !SI.isAtomic())
         storeOrigin(IRB, Addr, Shadow, getOrigin(Val), SI.getAlignment(),
                     InstrumentWithCalls);
     }
diff --git a/test/Instrumentation/MemorySanitizer/atomics.ll b/test/Instrumentation/MemorySanitizer/atomics.ll
index c8f3b88815b..28736ad7902 100644
--- a/test/Instrumentation/MemorySanitizer/atomics.ll
+++ b/test/Instrumentation/MemorySanitizer/atomics.ll
@@ -1,4 +1,6 @@
 ; RUN: opt < %s -msan -msan-check-access-address=0 -S | FileCheck %s
+; RUN: opt < %s -msan -msan-check-access-address=0 -msan-track-origins=1 -S | FileCheck %s
+; RUN: opt < %s -msan -msan-check-access-address=0 -msan-track-origins=2 -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"
 target triple = "x86_64-unknown-linux-gnu"