On Wed, Jul 20, 2011 at 07:26:02PM +0530, Krishna Kumar wrote:
> Fix a panic in virtnet_remove. unregister_netdev has already
> freed up the netdev (and virtnet_info) due to dev->destructor
> being set, while virtnet_info is still required. Remove
> virtnet_free altogether, and move the freeing of the per-cpu
> statistics from virtnet_free to virtnet_remove.
>
> Tested patch below.
>
> Signed-off-by: Krishna Kumar <krkumar2@xxxxxxxxxx>
Also note that the crash was apparently introduced by
3fa2a1df909482cc234524906e4bd30dee3514df in net-next,
so this is a net-next only patch.
Stephen, was there any special reason to free the memory
in the destructor like you did?
Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
> ---
> (Michael suggested me to re-post with copy to all maintainers)
>
> drivers/net/virtio_net.c | 10 +---------
> 1 file changed, 1 insertion(+), 9 deletions(-)
>
> diff -ruNp org/drivers/net/virtio_net.c new/drivers/net/virtio_net.c
> --- org/drivers/net/virtio_net.c 2011-07-18 09:14:02.000000000 +0530
> +++ new/drivers/net/virtio_net.c 2011-07-18 09:16:35.000000000 +0530
> @@ -705,14 +705,6 @@ static void virtnet_netpoll(struct net_d
> }
> #endif
>
> -static void virtnet_free(struct net_device *dev)
> -{
> - struct virtnet_info *vi = netdev_priv(dev);
> -
> - free_percpu(vi->stats);
> - free_netdev(dev);
> -}
> -
> static int virtnet_open(struct net_device *dev)
> {
> struct virtnet_info *vi = netdev_priv(dev);
> @@ -959,7 +951,6 @@ static int virtnet_probe(struct virtio_d
> /* Set up network device as normal. */
> dev->netdev_ops = &virtnet_netdev;
> dev->features = NETIF_F_HIGHDMA;
> - dev->destructor = virtnet_free;
>
> SET_ETHTOOL_OPS(dev, &virtnet_ethtool_ops);
> SET_NETDEV_DEV(dev, &vdev->dev);
> @@ -1122,6 +1113,7 @@ static void __devexit virtnet_remove(str
> while (vi->pages)
> __free_pages(get_a_page(vi, GFP_KERNEL), 0);
>
> + free_percpu(vi->stats);
> free_netdev(vi->dev);
> }
>
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