Patch "tools/virtio: fix READ_ONCE()" has been added to the 4.9-stable tree

Patch "tools/virtio: fix READ_ONCE()" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    tools/virtio: fix READ_ONCE()

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     tools-virtio-fix-read_once.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 5da889c795b1fbefc9d8f058b54717ab8ab17891 Mon Sep 17 00:00:00 2001
From: Mark Rutland <mark.rutland@arm.com>
Date: Thu, 24 Nov 2016 10:25:12 +0000
Subject: tools/virtio: fix READ_ONCE()

From: Mark Rutland <mark.rutland@arm.com>

commit 5da889c795b1fbefc9d8f058b54717ab8ab17891 upstream.

The virtio tools implementation of READ_ONCE() has a single parameter called
'var', but erroneously refers to 'val' for its cast, and thus won't work unless
there's a variable of the correct type that happens to be called 'var'.

Fix this with s/var/val/, making READ_ONCE() work as expected regardless.

Fixes: a7c490333df3cff5 ("tools/virtio: use virt_xxx barriers")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: linux-kernel@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 tools/virtio/linux/compiler.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/tools/virtio/linux/compiler.h
+++ b/tools/virtio/linux/compiler.h
@@ -4,6 +4,6 @@
 #define WRITE_ONCE(var, val) \
 	(*((volatile typeof(val) *)(&(var))) = (val))
 
-#define READ_ONCE(var) (*((volatile typeof(val) *)(&(var))))
+#define READ_ONCE(var) (*((volatile typeof(var) *)(&(var))))
 
 #endif


Patches currently in stable-queue which might be from mark.rutland@arm.com are

queue-4.9/tools-virtio-fix-read_once.patch
queue-4.9/bus-arm-ccn-prevent-hotplug-callback-leak.patch