netdev - Re: [PATCH v3 net-next 1/1] net_sched: Introduce skbmod action

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <57C415EB.80806@iogearbox.net>
Date:   Mon, 29 Aug 2016 13:00:59 +0200
From:   Daniel Borkmann <daniel@...earbox.net>
To:     Jamal Hadi Salim <jhs@...atatu.com>,
        Eric Dumazet <eric.dumazet@...il.com>
CC:     davem@...emloft.net, netdev@...r.kernel.org,
        xiyou.wangcong@...il.com
Subject: Re: [PATCH v3 net-next 1/1] net_sched: Introduce skbmod action

On 08/29/2016 12:38 PM, Jamal Hadi Salim wrote:
> On 16-08-28 12:07 PM, Eric Dumazet wrote:
>
>> Adding an action with a spinlock held in fast path in 2016 is
>> a way to tell people : It is a toy, do not use it for real.
>>
>> Sorry guys. Friends do not let friends do that anymore.
>
> Generally agree.
> Cong says he is working on generic patches. Let me see if i can
> try something. Trickery with RCU is not one of my virtues -
> so i may get it wrong but hope you can comment.

You could probably just keep these meta data in a separate struct
managed by RCU that tcf_skbmod points to.

One more thing I commented on your last patch already is that you
would also need f.e. skb_ensure_writable() before mangling.