Re: [Qemu-devel] [PATCHv4 01/11] virtio-serial-bus: use correct lengths in control_out() message

[Anthony Liguori <anthony@codemonkey.ws>]

On 03/15/2012 04:00 PM, Michael Tokarev wrote:
> In case of more than one control message, the code will use
> size of the largest message so far for all subsequent messages,
> instead of using size of current one.  Fix it.
>
> Signed-off-by: Michael Tokarev<mjt@tls.msk.ru>
> ---
>   hw/virtio-serial-bus.c |    6 +++---
>   1 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/hw/virtio-serial-bus.c b/hw/virtio-serial-bus.c
> index e22940e..abe48ec 100644
> --- a/hw/virtio-serial-bus.c
> +++ b/hw/virtio-serial-bus.c
> @@ -454,7 +454,7 @@ static void control_out(VirtIODevice *vdev, VirtQueue *vq)
>       len = 0;
>       buf = NULL;
>       while (virtqueue_pop(vq,&elem)) {
> -        size_t cur_len, copied;
> +        size_t cur_len;
>
>           cur_len = iov_size(elem.out_sg, elem.out_num);
>           /*
> @@ -467,9 +467,9 @@ static void control_out(VirtIODevice *vdev, VirtQueue *vq)
>               buf = g_malloc(cur_len);
>               len = cur_len;
>           }
> -        copied = iov_to_buf(elem.out_sg, elem.out_num, buf, 0, len);
> +        iov_to_buf(elem.out_sg, elem.out_num, buf, 0, cur_len);

I don't understand what this is fixing.  copied = cur_len unless for some reason 
a full copy couldn't be done.

But you're assuming a full copy is done.  So I'm confused by what is being fixed 
here.

Regards,

Anthony Liguori

> -        handle_control_message(vser, buf, copied);
> +        handle_control_message(vser, buf, cur_len);
>           virtqueue_push(vq,&elem, 0);
>       }
>       g_free(buf);