[PATCH] xen: unitialised return value in xenbus_write_transaction

[PATCH] xen: unitialised return value in xenbus_write_transaction

[Ian Campbell]

The return value of xenbus_write_transaction can be uninitialised in
the success case leading to the userspace xenstore utilities failing.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Adam Wendt <thelsdj@gmail.com>
Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Ingo Molnar <mingo@elte.hu>

---
 drivers/xen/xenfs/xenbus.c |   11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff -r 7c66d3ac6805 -r 03f51a1eb4a7 drivers/xen/xenfs/xenbus.c
--- a/drivers/xen/xenfs/xenbus.c	Fri Jan 23 16:42:41 2009 +0000
+++ b/drivers/xen/xenfs/xenbus.c	Fri Jan 23 16:42:41 2009 +0000
@@ -291,7 +291,7 @@
 static int xenbus_write_transaction(unsigned msg_type,
 				    struct xenbus_file_priv *u)
 {
-	int rc, ret;
+	int rc;
 	void *reply;
 	struct xenbus_transaction_holder *trans = NULL;
 	LIST_HEAD(staging_q);
@@ -326,15 +326,14 @@
 	}
 
 	mutex_lock(&u->reply_mutex);
-	ret = queue_reply(&staging_q, &u->u.msg, sizeof(u->u.msg));
-	if (!ret)
-		ret = queue_reply(&staging_q, reply, u->u.msg.len);
-	if (!ret) {
+	rc = queue_reply(&staging_q, &u->u.msg, sizeof(u->u.msg));
+	if (!rc)
+		rc = queue_reply(&staging_q, reply, u->u.msg.len);
+	if (!rc) {
 		list_splice_tail(&staging_q, &u->read_buffers);
 		wake_up(&u->read_waitq);
 	} else {
 		queue_cleanup(&staging_q);
-		rc = ret;
 	}
 	mutex_unlock(&u->reply_mutex);
 

Re: [PATCH] xen: unitialised return value in xenbus_write_transaction

[Ingo Molnar]

* Ian Campbell <ian.campbell@citrix.com> wrote:

> The return value of xenbus_write_transaction can be uninitialised in
> the success case leading to the userspace xenstore utilities failing.
> 
> Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
> Cc: Adam Wendt <thelsdj@gmail.com>
> Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
> Cc: Ingo Molnar <mingo@elte.hu>
> 
> ---
>  drivers/xen/xenfs/xenbus.c |   11 +++++------
>  1 file changed, 5 insertions(+), 6 deletions(-)

applied to tip/x86/urgent, thanks Ian!

	Ingo