[PATCH 09/10] virtio: console: add locking in port unplug path

[Amit Shah <amit.shah@redhat.com>]

Port unplug can race with close() in port_fops_release().
port_fops_release() already takes the necessary locks, ensure
unplug_port() does that too.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
---
 drivers/char/virtio_console.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index dd0020d..b174945 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -1545,6 +1545,7 @@ static void unplug_port(struct port *port)
 	list_del(&port->list);
 	spin_unlock_irq(&port->portdev->ports_lock);
 
+	spin_lock_irq(&port->inbuf_lock);
 	if (port->guest_connected) {
 		port->host_connected = false;
 		wake_up_interruptible(&port->waitqueue);
@@ -1555,6 +1556,7 @@ static void unplug_port(struct port *port)
 		/* Do this last so that sigio is actually sent */
 		port->guest_connected = false;
 	}
+	spin_unlock_irq(&port->inbuf_lock);
 
 	if (is_console_port(port)) {
 		spin_lock_irq(&pdrvdata_lock);
-- 
1.8.1.4