Remove any data that we might have in a port's inbuf when closing a port or when any data is received when a port is closed.
Signed-off-by: Amit Shah <[email protected]> --- drivers/char/virtio_console.c | 40 ++++++++++++++++++++++++++++++++++++++++ 1 files changed, 40 insertions(+), 0 deletions(-) diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index 7154224..0be5562 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -325,6 +325,31 @@ static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf) return ret; } +/* Discard any unread data this port has. Callers lockers. */ +static void discard_port_data(struct port *port) +{ + struct port_buffer *buf; + struct virtqueue *vq; + unsigned int len; + + vq = port->in_vq; + if (port->inbuf) + buf = port->inbuf; + else + buf = vq->vq_ops->get_buf(vq, &len); + + if (!buf) + return; + + if (add_inbuf(vq, buf) < 0) { + buf->len = buf->offset = 0; + dev_warn(port->dev, "Error adding buffer back to vq\n"); + return; + } + + port->inbuf = NULL; +} + static bool port_has_data(struct port *port) { unsigned long flags; @@ -554,8 +579,13 @@ static int port_fops_release(struct inode *inode, struct file *filp) /* Notify host of port being closed */ send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0); + spin_lock_irq(&port->inbuf_lock); port->guest_connected = false; + discard_port_data(port); + + spin_unlock_irq(&port->inbuf_lock); + return 0; } @@ -904,6 +934,16 @@ static void in_intr(struct virtqueue *vq) spin_lock_irqsave(&port->inbuf_lock, flags); port->inbuf = get_inbuf(port); + /* + * Don't queue up data when port is closed. This condition + * can be reached when a console port is not yet connected (no + * tty is spawned) and the host sends out data to console + * ports. For generic serial ports, the host won't + * (shouldn't) send data till the guest is connected. + */ + if (!port->guest_connected) + discard_port_data(port); + spin_unlock_irqrestore(&port->inbuf_lock, flags); wake_up_interruptible(&port->waitqueue); -- 1.6.2.5 _______________________________________________ Virtualization mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/virtualization
