From: Hans Wennborg <hans@hanshq.net>
Date: Fri, 6 Feb 2015 22:06:43 +0000 (+0000)
Subject: Merging r228444:
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=d085961d8c02c5b13163e70298b89ca08cea3ece;p=llvm

Merging r228444:
------------------------------------------------------------------------
r228444 | eugenis | 2015-02-06 13:47:39 -0800 (Fri, 06 Feb 2015) | 8 lines

[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/branches/release_36@228445 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Transforms/Instrumentation/MemorySanitizer.cpp b/lib/Transforms/Instrumentation/MemorySanitizer.cpp
index 9f00d3d6c82..d7d752ff524 100644
--- a/lib/Transforms/Instrumentation/MemorySanitizer.cpp
+++ b/lib/Transforms/Instrumentation/MemorySanitizer.cpp
@@ -631,7 +631,7 @@ 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"