[PATCH] xen/9pfs: initialize len to 0 to detect xenbus_read errors

[PATCH] xen/9pfs: initialize len to 0 to detect xenbus_read errors

[Stefano Stabellini]

In order to use "len" to check for xenbus_read errors properly, we need
to initialize len to 0 before passing it to xenbus_read.

Signed-off-by: Stefano Stabellini <stefano@aporeto.com>
CC: dan.carpenter@oracle.com
CC: jgross@suse.com
CC: boris.ostrovsky@oracle.com
CC: Eric Van Hensbergen <ericvh@gmail.com>
CC: Ron Minnich <rminnich@sandia.gov>
CC: Latchesar Ionkov <lucho@ionkov.net>
CC: v9fs-developer@lists.sourceforge.net

---
Juergen, you could also merge this patch into commit
e9c53da56ff36458b1b8df95573f5dac80a1a956
---
---
 net/9p/trans_xen.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/9p/trans_xen.c b/net/9p/trans_xen.c
index 4786424..71e8564 100644
--- a/net/9p/trans_xen.c
+++ b/net/9p/trans_xen.c
@@ -386,7 +386,7 @@ static int xen_9pfs_front_probe(struct xenbus_device *dev,
 	struct xenbus_transaction xbt;
 	struct xen_9pfs_front_priv *priv = NULL;
 	char *versions;
-	unsigned int max_rings, max_ring_order, len;
+	unsigned int max_rings, max_ring_order, len = 0;
 
 	versions = xenbus_read(XBT_NIL, dev->otherend, "versions", &len);
 	if (!len)
-- 
1.9.1

Re: [PATCH] xen/9pfs: initialize len to 0 to detect xenbus_read errors

[Juergen Gross]

On 13/04/17 19:57, Stefano Stabellini wrote:
> In order to use "len" to check for xenbus_read errors properly, we need
> to initialize len to 0 before passing it to xenbus_read.
> 
> Signed-off-by: Stefano Stabellini <stefano@aporeto.com>
> CC: dan.carpenter@oracle.com
> CC: jgross@suse.com
> CC: boris.ostrovsky@oracle.com
> CC: Eric Van Hensbergen <ericvh@gmail.com>
> CC: Ron Minnich <rminnich@sandia.gov>
> CC: Latchesar Ionkov <lucho@ionkov.net>
> CC: v9fs-developer@lists.sourceforge.net

Committed to xen/tip for-linus-4.12


Thanks,

Juergen