netdev - Re: [PATCH bpf-next] bpf: Add BPF-helper for accessing CLOCK

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: <CAADnVQ+aDn9ku8p0M2yaPQb_Qi3CxkcyhHbcKTq8y2hrDP5A8Q@mail.gmail.com>
Date:   Tue, 2 Aug 2022 08:03:34 -0700
From:   Alexei Starovoitov <alexei.starovoitov@...il.com>
To:     Kurt Kanzenbach <kurt@...utronix.de>
Cc:     Jesper Dangaard Brouer <jbrouer@...hat.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Jesper Dangaard Brouer <brouer@...hat.com>,
        Alexei Starovoitov <ast@...nel.org>,
        Daniel Borkmann <daniel@...earbox.net>,
        Andrii Nakryiko <andrii@...nel.org>,
        Martin KaFai Lau <kafai@...com>,
        Song Liu <songliubraving@...com>, Yonghong Song <yhs@...com>,
        John Fastabend <john.fastabend@...il.com>,
        KP Singh <kpsingh@...nel.org>,
        Joanne Koong <joannelkoong@...il.com>,
        Jiri Olsa <jolsa@...nel.org>,
        Dave Marchevsky <davemarchevsky@...com>,
        Lorenzo Bianconi <lorenzo@...nel.org>,
        Geliang Tang <geliang.tang@...e.com>,
        Jakub Sitnicki <jakub@...udflare.com>,
        Network Development <netdev@...r.kernel.org>,
        bpf <bpf@...r.kernel.org>
Subject: Re: [PATCH bpf-next] bpf: Add BPF-helper for accessing CLOCK_TAI

On Tue, Aug 2, 2022 at 12:06 AM Kurt Kanzenbach <kurt@...utronix.de> wrote:
>
> Hi Alexei,
>
> On Tue Jun 07 2022, Alexei Starovoitov wrote:
> > Anyway I guess new helper bpf_ktime_get_tai_ns() is ok, since
> > it's so trivial, but selftest is necessary.
>
> So, I did write a selftest [1] for testing bpf_ktime_get_tai_ns() and
> verifying that the access to the clock works. It uses AF_XDP sockets and
> timestamps the incoming packets. The timestamps are then validated in
> user space.
>
> Since AF_XDP related code is migrating from libbpf to libxdp, I'm
> wondering if that sample fits into the kernel's selftests or not. What
> kind of selftest are you looking for?

Please use selftests/bpf framework.
There are plenty of networking tests in there.
bpf_ktime_get_tai_ns() doesn't have to rely on af_xdp.
It can be skb based.