netdev - Re: [RFC PATCH bpf-next] bpf: Introduce bpf

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]

Date:   Mon, 24 May 2021 20:16:44 -0700
From:   Cong Wang <xiyou.wangcong@...il.com>
To:     Alexei Starovoitov <alexei.starovoitov@...il.com>
Cc:     David Miller <davem@...emloft.net>,
        Daniel Borkmann <daniel@...earbox.net>,
        Andrii Nakryiko <andrii@...nel.org>,
        John Fastabend <john.fastabend@...il.com>,
        Lorenz Bauer <lmb@...udflare.com>,
        Linux Kernel Network Developers <netdev@...r.kernel.org>,
        bpf <bpf@...r.kernel.org>, kernel-team <kernel-team@...com>
Subject: Re: [RFC PATCH bpf-next] bpf: Introduce bpf_timer

On Sun, May 23, 2021 at 9:01 AM Alexei Starovoitov
<alexei.starovoitov@...il.com> wrote:
>
> On Fri, May 21, 2021 at 2:37 PM Cong Wang <xiyou.wangcong@...il.com> wrote:
> >
> > Hi, Alexei
> >
> > On Thu, May 20, 2021 at 11:52 PM Alexei Starovoitov
> > <alexei.starovoitov@...il.com> wrote:
> > >
> > > From: Alexei Starovoitov <ast@...nel.org>
> >
> > Why do you intentionally keep people in the original discussion
> > out of your CC? Remember you are the one who objected the
> > idea by questioning its usefulness no matter how I hard I tried
> > to explain? I am glad you changed your mind, but it does not
> > mean you should forget to credit other people.
>
> I didn't change my mind and I still object to your stated
> _reasons_ for timers.

What is _your reason_ to introduce timers? Clearly you provide
absolutely nothing here. ;)


>
> > >
> > > Introduce 'struct bpf_timer' that can be embedded in most BPF map types
> > > and helpers to operate on it:
> > > long bpf_timer_init(struct bpf_timer *timer, void *callback, int flags)
> > > long bpf_timer_mod(struct bpf_timer *timer, u64 msecs)
> > > long bpf_timer_del(struct bpf_timer *timer)
> >
> > Like we discussed, this approach would make the timer harder
> > to be independent of other eBPF programs, which is a must-have
> > for both of our use cases (mine and Jamal's). Like you explained,
> > this requires at least another program array, a tail call, a mandatory
> > prog pinning to work.
>
> That is simply not true.

Which part is not true? The above is what I got from your explanation.

Thanks.