linux-kernel - Re: [PATCH 0/6 v5 RESEND] seccomp: add the synchronous mode for seccomp

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: <CANaxB-yLtPvd7z-9-dAGAM98hjFqTpN_oHbbpCawtFrPW6JBWQ@mail.gmail.com>
Date:   Tue, 21 Mar 2023 11:19:03 -0700
From:   Andrei Vagin <avagin@...il.com>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     Kees Cook <keescook@...omium.org>, linux-kernel@...r.kernel.org,
        Christian Brauner <brauner@...nel.org>,
        Chen Yu <yu.c.chen@...el.com>,
        Andrei Vagin <avagin@...gle.com>,
        Andy Lutomirski <luto@...capital.net>,
        Dietmar Eggemann <dietmar.eggemann@....com>,
        Ingo Molnar <mingo@...hat.com>,
        Juri Lelli <juri.lelli@...hat.com>,
        Peter Oskolkov <posk@...gle.com>,
        Tycho Andersen <tycho@...ho.pizza>,
        Will Drewry <wad@...omium.org>,
        Vincent Guittot <vincent.guittot@...aro.org>
Subject: Re: [PATCH 0/6 v5 RESEND] seccomp: add the synchronous mode for seccomp_unotify

On Tue, Mar 7, 2023 at 11:32 PM Andrei Vagin <avagin@...gle.com> wrote:
>
> seccomp_unotify allows more privileged processes do actions on behalf
> of less privileged processes.
>
> In many cases, the workflow is fully synchronous. It means a target
> process triggers a system call and passes controls to a supervisor
> process that handles the system call and returns controls back to the
> target process. In this context, "synchronous" means that only one
> process is running and another one is waiting.
>
> The new WF_CURRENT_CPU flag advises the scheduler to move the wakee to
> the current CPU. For such synchronous workflows, it makes context
> switches a few times faster.
>
> Right now, each interaction takes 12µs. With this patch, it takes about
> 3µs.
>
> v2: clean up the first patch and add the test.
> v3: update commit messages and a few fixes suggested by Kees Cook.
> v4: update the third patch to avoid code duplications (suggested by
>     Peter Zijlstra)
>     Add the benchmark to the perf bench set.
> v5: Update the author email. No code changes.
>
> Kees is ready to take this patch set, but wants to get Acks from the
> sched folks.

Peter, could you review the second and third patches of this series?

Thanks,
Andrei