Re: [PATCH v3 8/9] virtio: console: fix locking around send_sigio_to_port()

[Rusty Russell <rusty@rustcorp.com.au>]

Amit Shah <amit.shah@redhat.com> writes:
> 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>

Applied,
Rusty.

> ---
>  drivers/char/virtio_console.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
> index e8b707d..4e380c1 100644
> --- a/drivers/char/virtio_console.c
> +++ b/drivers/char/virtio_console.c
> @@ -1670,7 +1670,9 @@ static void handle_control_message(struct ports_device *portdev,
>  		 * 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:
>  		/*
> @@ -1790,13 +1792,13 @@ static void in_intr(struct virtqueue *vq)
>  	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();
>  }
> -- 
> 1.8.1.4