Subject: Re: tun issue after e0b46d0ee9c: tun: Use iovec iterators

From: Al Viro <[email-masked]>
Date: Fri, 28 Nov 2014 22:35:03 +0000

On Fri, Nov 28, 2014 at 08:10:03PM -0200, Marcelo Ricardo Leitner wrote:
> >Could you print vnet_hdr_sz and sizeof(gso) right after that
> >copy_from_iter(&gso, ...)?
> 
> Did a:
>         else {
>                 err = skb_copy_datagram_from_iter(skb, 0, from, len);
> +               pr_err("vnet_hdr_sz=%d sizeof(gso)=%lu\n",
> tun->vnet_hdr_sz, sizeof(gso));
>                 if (!err && msg_control) {
> 
> Got, for tun:
> [   50.514165] tun: vnet_hdr_sz=12 sizeof(gso)=10
> 
> for tap:
> [   82.911840] tun: vnet_hdr_sz=10 sizeof(gso)=10
> 
> other values were just as before.

Hmm...  Do you have
commit 8c847d254146d32c86574a1b16923ff91bb784dd
Author: Jason Wang <[email-masked]>
Date:   Thu Nov 13 16:54:14 2014 +0800

    tun: fix issues of iovec iterators using in tun_put_user()
in your tree?