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From:   Ricardo Ribalda <ribalda@chromium.org>
Date:   Wed, 28 Jun 2023 17:59:59 +0200
Message-ID: <CANiDSCtu1OvoRe0ReqBVctzd8euZDt-h7dyx+xACWzdQeHkxBA@mail.gmail.com>
Subject: Re: [PATCH 1/1] Add a new sysctl to disable io_uring system-wide
To:     Matteo Rizzo <matteorizzo@google.com>
Cc:     Bart Van Assche <bvanassche@acm.org>, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org, io-uring@vger.kernel.org,
        jordyzomer@google.com, evn@google.com, poprdi@google.com,
        corbet@lwn.net, axboe@kernel.dk, asml.silence@gmail.com,
        akpm@linux-foundation.org, keescook@chromium.org,
        rostedt@goodmis.org, dave.hansen@linux.intel.com,
        chenhuacai@kernel.org, steve@sk2.org, gpiccoli@igalia.com,
        ldufour@linux.ibm.com
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HI Matteo

On Wed, 28 Jun 2023 at 17:12, Matteo Rizzo <matteorizzo@google.com> wrote:
>
> On Wed, 28 Jun 2023 at 13:44, Ricardo Ribalda <ribalda@chromium.org> wrote:
> >
> > Have you considered that the new sysctl is "sticky like kexec_load_disabled.
> > When the user disables it there is no way to turn it back on until the
> > system is rebooted.
>
> Are you suggesting making this sysctl sticky? Are there any examples of how to
> implement a sticky sysctl that can take more than 2 values in case we want to
> add an intermediate level that still allows privileged processes to use
> io_uring? Also, what would be the use case? Preventing privileged processes
> from re-enabling io_uring?

Yes, if this sysctl is accepted, I think it would make sense to make it sticky.

For more than one value take a look to  kexec_load_limit_reboot and
kexec_load_limit_panic

Thanks!

>
> Thanks!
> --
> Matteo


-- 
Ricardo Ribalda