From: Paul Durrant <paul.durrant@citrix.com>
Date: Mon, 26 Jan 2015 15:39:54 +0000 (+0000)
Subject: Add missing barrier
X-Git-Tag: 8.1.0-rc1~79
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=a9133a8f1988aa6154d16960f6f0b93ae200d129;p=pvdrivers%2Fwin%2Fxenbus.git

Add missing barrier

Testing an event word flag should always be preceded by a barrier (unless
using a locked operation).

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
---

diff --git a/src/xenbus/evtchn_fifo.c b/src/xenbus/evtchn_fifo.c
index e045cd0..cef639d 100644
--- a/src/xenbus/evtchn_fifo.c
+++ b/src/xenbus/evtchn_fifo.c
@@ -102,6 +102,7 @@ __EvtchnFifoTestFlag(
     IN  ULONG           Flag
     )
 {
+    KeMemoryBarrier();
     return (*EventWord & (1 << Flag)) ? TRUE : FALSE;
 }