Subject: Re: [PATCH net] tun: handle copy failure in tun_put_user()

From: Jason Wang <[email-masked]>
Date: Mon, 20 Jan 2014 13:02:38 +0800

On 01/20/2014 11:48 AM, David Miller wrote:
> From: Jason Wang <[email-masked]>
> Date: Mon, 20 Jan 2014 11:16:48 +0800
>
>> This patch return the error code of copy helpers in tun_put_user() instead of
>> ignoring them.
>>
>> Cc: Michael S. Tsirkin <[email-masked]>
>> Signed-off-by: Jason Wang <[email-masked]>
> If you perform some of the copy successfully, you have to report that
> length rather than just an error.
>
> Otherwise userland has no way to determine how much of the data was
> successfully sourced.
>
> I'm not applying this, sorry.

Right, looks like we need more changes in tun to return the accurate
length copied in this case.