connector: Keep the skb in cn_callback_data

(cherry picked from commit 5491c43845dae6c68cb4edbcf2e2dde9a32a863d)
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/connector/cn_queue.c

@@ -78,8 +78,9 @@ void cn_queue_wrapper(struct work_struct *work)
 	struct cn_callback_entry *cbq =
 		container_of(work, struct cn_callback_entry, work);
 	struct cn_callback_data *d = &cbq->data;
+	struct cn_msg *msg = NLMSG_DATA(nlmsg_hdr(d->skb));
 
-	d->callback(d->callback_priv);
+	d->callback(msg);
 
 	d->destruct_data(d->ddata);
 	d->ddata = NULL;

drivers/connector/connector.c

@@ -129,10 +129,11 @@ EXPORT_SYMBOL_GPL(cn_netlink_send);
 /*
  * Callback helper - queues work and setup destructor for given data.
  */
-static int cn_call_callback(struct cn_msg *msg, void (*destruct_data)(void *), void *data)
+static int cn_call_callback(struct sk_buff *skb, void (*destruct_data)(void *), void *data)
 {
 	struct cn_callback_entry *__cbq, *__new_cbq;
 	struct cn_dev *dev = &cdev;
+	struct cn_msg *msg = NLMSG_DATA(nlmsg_hdr(skb));
 	int err = -ENODEV;
 
 	spin_lock_bh(&dev->cbdev->queue_lock);
@@ -140,7 +141,7 @@ static int cn_call_callback(struct cn_msg *msg, void (*destruct_data)(void *), v
 		if (cn_cb_equal(&__cbq->id.id, &msg->id)) {
 			if (likely(!work_pending(&__cbq->work) &&
 					__cbq->data.ddata == NULL)) {
-				__cbq->data.callback_priv = msg;
+				__cbq->data.skb = skb;
 
 				__cbq->data.ddata = data;
 				__cbq->data.destruct_data = destruct_data;
@@ -156,7 +157,7 @@ static int cn_call_callback(struct cn_msg *msg, void (*destruct_data)(void *), v
 				__new_cbq = kzalloc(sizeof(struct cn_callback_entry), GFP_ATOMIC);
 				if (__new_cbq) {
 					d = &__new_cbq->data;
-					d->callback_priv = msg;
+					d->skb = skb;
 					d->callback = __cbq->data.callback;
 					d->ddata = data;
 					d->destruct_data = destruct_data;
@@ -191,7 +192,6 @@ static int cn_call_callback(struct cn_msg *msg, void (*destruct_data)(void *), v
  */
 static void cn_rx_skb(struct sk_buff *__skb)
 {
-	struct cn_msg *msg;
 	struct nlmsghdr *nlh;
 	int err;
 	struct sk_buff *skb;
@@ -208,8 +208,7 @@ static void cn_rx_skb(struct sk_buff *__skb)
 			return;
 		}
 
-		msg = NLMSG_DATA(nlh);
-		err = cn_call_callback(msg, (void (*)(void *))kfree_skb, skb);
+		err = cn_call_callback(skb, (void (*)(void *))kfree_skb, skb);
 		if (err < 0)
 			kfree_skb(skb);
 	}

include/linux/connector.h

@@ -135,8 +135,8 @@ struct cn_callback_data {
 	void (*destruct_data) (void *);
 	void *ddata;
 
-	void *callback_priv;
-	void (*callback) (void *);
+	struct sk_buff *skb;
+	void (*callback) (struct cn_msg *);
 
 	void *free;
 };