xen: close evtchn port if binding to irq fails

CC: stable@vger.kernel.org
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
diff --git a/drivers/xen/evtchn.c b/drivers/xen/evtchn.c
index 4ebd501..45c8efa 100644
--- a/drivers/xen/evtchn.c
+++ b/drivers/xen/evtchn.c
@@ -269,6 +269,14 @@
 				       u->name, (void *)(unsigned long)port);
 	if (rc >= 0)
 		rc = evtchn_make_refcounted(port);
+	else {
+		/* bind failed, should close the port now */
+		struct evtchn_close close;
+		close.port = port;
+		if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
+			BUG();
+		set_port_user(port, NULL);
+	}
 
 	return rc;
 }
@@ -277,6 +285,8 @@
 {
 	int irq = irq_from_evtchn(port);
 
+	BUG_ON(irq < 0);
+
 	unbind_from_irqhandler(irq, (void *)(unsigned long)port);
 
 	set_port_user(port, NULL);