[Bluetooth] Signal user-space for HIDP and BNEP socket errors

When using the HIDP or BNEP kernel support, the user-space needs to
know if the connection has been terminated for some reasons. Wake up
the application if that happens. Otherwise kernel and user-space are
no longer on the same page and weird behaviors can happen.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

net/bluetooth/bnep/core.c

@@ -507,6 +507,11 @@ static int bnep_session(void *arg)
 	/* Delete network device */
 	unregister_netdev(dev);
 
+	/* Wakeup user-space polling for socket errors */
+	s->sock->sk->sk_err = EUNATCH;
+
+	wake_up_interruptible(s->sock->sk->sk_sleep);
+
 	/* Release the socket */
 	fput(s->sock->file);
 

net/bluetooth/hidp/core.c

@@ -581,6 +581,12 @@ static int hidp_session(void *arg)
 		hid_free_device(session->hid);
 	}
 
+	/* Wakeup user-space polling for socket errors */
+	session->intr_sock->sk->sk_err = EUNATCH;
+	session->ctrl_sock->sk->sk_err = EUNATCH;
+
+	hidp_schedule(session);
+
 	fput(session->intr_sock->file);
 
 	wait_event_timeout(*(ctrl_sk->sk_sleep),
@@ -879,6 +885,10 @@ int hidp_del_connection(struct hidp_conndel_req *req)
 			skb_queue_purge(&session->ctrl_transmit);
 			skb_queue_purge(&session->intr_transmit);
 
+			/* Wakeup user-space polling for socket errors */
+			session->intr_sock->sk->sk_err = EUNATCH;
+			session->ctrl_sock->sk->sk_err = EUNATCH;
+
 			/* Kill session thread */
 			atomic_inc(&session->terminate);
 			hidp_schedule(session);