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In-Reply-To: <f185bb42-b29c-977e-312e-3349eea15383@linuxfoundation.org>
From:   Jeff Xu <jeffxu@google.com>
Date:   Fri, 23 Dec 2022 10:06:49 -0800
Message-ID: <CALmYWFs3Qm_89e8cCcVu0otrZpMVe3rWxqANAQwQDJgaK3S+oA@mail.gmail.com>
Subject: Re: [PATCH v6 3/6] mm/memfd: add MFD_NOEXEC_SEAL and MFD_EXEC
To:     Shuah Khan <skhan@linuxfoundation.org>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Kees Cook <keescook@chromium.org>,
        Peter Xu <peterx@redhat.com>, jeffxu@chromium.org,
        dmitry.torokhov@gmail.com, dverkamp@chromium.org, hughd@google.com,
        jorgelo@chromium.org, linux-kernel@vger.kernel.org,
        linux-kselftest@vger.kernel.org, linux-mm@kvack.org,
        jannh@google.com, linux-hardening@vger.kernel.org,
        kernel test robot <lkp@intel.com>
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On Tue, Dec 20, 2022 at 8:55 AM Shuah Khan <skhan@linuxfoundation.org> wrote:
>
> On 12/16/22 16:40, Jeff Xu wrote:
> > On Fri, Dec 16, 2022 at 2:06 PM Andrew Morton <akpm@linux-foundation.org> wrote:
> >>
> >> On Fri, 16 Dec 2022 13:46:58 -0800 Jeff Xu <jeffxu@google.com> wrote:
> >>
> >>> On Fri, Dec 16, 2022 at 12:35 PM Kees Cook <keescook@chromium.org> wrote:
> >>>>
> >>>> On Fri, Dec 16, 2022 at 10:11:44AM -0800, Jeff Xu wrote:
> >>>>> Once per boot seems too little, it would be nice if we can list all processes.
> >>>>> I agree ratelimited might be too much.
> >>>>> There is a feature gap here for logging.
> >>>>>
> >>>>> Kees, what do you think ?
> >>>>
> >>>> I agree once per boot is kind of frustrating "I fixed the one warning,
> >>>> oh, now it's coming from a different process". But ratelimit is, in
> >>>> retrospect, still too often.
> >>>>
> >>>> Let's go with per boot -- this should be noisy "enough" to get the
> >>>> changes in API into the callers without being too much of a hassle.
> >>>>
> >>> Agreed.  Let's go with per boot.
> >>>
> >>> Hi Andrew, what is your preference ? I can send a patch  or you
> >>> directly fix it in mm-unstable ?
> >>
> >> Like this?
> >>
> > Yes. Thanks!
> >
>
> Sorry jumping into this discussion a bit late. Is it possible to provide
> a way to enable full logging as a debug option to tag more processes?
>
Codewise it is possible, maybe by adding a sysctl or CONFIG_, but I am not sure
the best practice to do this with the kernel?

Kees/Andrew, do you have suggestions ?

Thanks
Jeff


> thanks,
> -- Shuah
>