netdev - Re: [PATCH bpf-next v7 0/3] Add skb + xdp dynptrs

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: <CAADnVQKhv2YBrUAQJq6UyqoZJ-FGNQbKenGoPySPNK+GaOjBOg@mail.gmail.com>
Date:   Thu, 20 Oct 2022 18:19:52 -0700
From:   Alexei Starovoitov <alexei.starovoitov@...il.com>
To:     Joanne Koong <joannelkoong@...il.com>
Cc:     bpf <bpf@...r.kernel.org>, Daniel Borkmann <daniel@...earbox.net>,
        Martin KaFai Lau <martin.lau@...nel.org>,
        Andrii Nakryiko <andrii@...nel.org>,
        Alexei Starovoitov <ast@...nel.org>,
        Network Development <netdev@...r.kernel.org>,
        Kernel Team <Kernel-team@...com>
Subject: Re: [PATCH bpf-next v7 0/3] Add skb + xdp dynptrs

On Thu, Oct 20, 2022 at 6:15 PM Joanne Koong <joannelkoong@...il.com> wrote:
>
> This patchset is the 2nd in the dynptr series. The 1st can be found here [0].
>
> This patchset adds skb and xdp type dynptrs, which have two main benefits for
> packet parsing:
>     * allowing operations on sizes that are not statically known at
>       compile-time (eg variable-sized accesses).
>     * more ergonomic and less brittle iteration through data (eg does not need
>       manual if checking for being within bounds of data_end)
>
> When comparing the differences in runtime for packet parsing without dynptrs
> vs. with dynptrs for the more simple cases, there is no noticeable difference.
> For the more complex cases where lengths are non-statically known at compile
> time, there can be a significant speed-up when using dynptrs (eg a 2x speed up
> for cls redirection). Patch 3 contains more details as well as examples of how
> to use skb and xdp dynptrs.

Before proceeding with this patchset I think we gotta resolve the
issues with dynptr-s that Kumar found.