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From:   Kees Cook <keescook@chromium.org>
Date:   Fri, 30 Nov 2018 20:28:50 -0800
Message-ID: <CAGXu5jKmz+zDH9nmYo=dwxWRNh=gYxb--Qy4x+KrFuBaT+L31w@mail.gmail.com>
Subject: Re: [PATCH] prctl: add PR_{GET,SET}_KILL_DESCENDANTS_ON_EXIT
To:     Oleg Nesterov <oleg@redhat.com>
Cc:     j@bitron.ch, "Eric W. Biederman" <ebiederm@xmission.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Andy Lutomirski <luto@kernel.org>,
        Linux API <linux-api@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>
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On Fri, Nov 30, 2018 at 2:33 AM Oleg Nesterov <oleg@redhat.com> wrote:
>
> On 11/29, J=C3=BCrg Billeter wrote:
> >
> > On Thu, 2018-11-29 at 13:34 +0100, Oleg Nesterov wrote:
> > > So I think the patch is mostly fine, the only problem I can see is th=
at
> > > PR_SET_KILL_DESCENDANTS_ON_EXIT can race with PR_SET_CHILD_SUBREAPER,=
 they both
> > > need to update the bits in the same word.
> >
> > Good point. I'll make it a regular bool instead of a bitfield for v2,
>
> Agreed,

Is it worth doing something for singal_struct like we did for
task_struct with the TASK_PFA_* and atomic_flags?

--=20
Kees Cook