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 e045cd0bbc2d7c26290a429efdb7eb613af631d0..cef639de71880988bc204bf3c67f4e89b6e91f23 100644 (file)
--- 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;
 }