virtio: console: fix locking around send_sigio_to_port()
send_sigio_to_port() checks the value of guest_connected, which we
always modify under the inbuf_lock; make sure invocations of
send_sigio_to_port() have take the inbuf_lock around the call.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 3572c5a..d5e2c70 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -1661,7 +1661,9 @@
* If the guest is connected, it'll be interested in
* knowing the host connection state changed.
*/
+ spin_lock_irq(&port->inbuf_lock);
send_sigio_to_port(port);
+ spin_unlock_irq(&port->inbuf_lock);
break;
case VIRTIO_CONSOLE_PORT_NAME:
/*
@@ -1781,13 +1783,13 @@
if (!port->guest_connected && !is_rproc_serial(port->portdev->vdev))
discard_port_data(port);
+ /* Send a SIGIO indicating new data in case the process asked for it */
+ send_sigio_to_port(port);
+
spin_unlock_irqrestore(&port->inbuf_lock, flags);
wake_up_interruptible(&port->waitqueue);
- /* Send a SIGIO indicating new data in case the process asked for it */
- send_sigio_to_port(port);
-
if (is_console_port(port) && hvc_poll(port->cons.hvc))
hvc_kick();
}