Message-id: <1417101862.1805.23.camel@samsung.com>
Subject: Re: [RFC] lsm: namespace hooks
From: Lukasz Pawelczyk <l.pawelczyk@samsung.com>
To: Richard Weinberger <richard@nod.at>
Cc: Ingo Molnar <mingo@redhat.com>, Peter Zijlstra <peterz@infradead.org>,
        James Morris <james.l.morris@oracle.com>,
        "Serge E. Hallyn" <serge@hallyn.com>,
        Serge Hallyn <serge.hallyn@canonical.com>,
        Al Viro <viro@zeniv.linux.org.uk>, Paul Moore <pmoore@redhat.com>,
        Kees Cook <keescook@chromium.org>, Miklos Szeredi <mszeredi@suse.cz>,
        Jeff Kirsher <jeffrey.t.kirsher@intel.com>,
        Nikolay Aleksandrov <nikolay@redhat.com>,
        Mark Rustad <mark.d.rustad@intel.com>,
        David Howells <dhowells@redhat.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Oleg Nesterov <oleg@redhat.com>, Juri Lelli <juri.lelli@gmail.com>,
        Daeseok Youn <daeseok.youn@gmail.com>,
        David Rientjes <rientjes@google.com>,
        Dario Faggioli <raistlin@linux.it>, Alex Thorlton <athorlton@sgi.com>,
        Matthew Dempsky <mdempsky@chromium.org>,
        Vladimir Davydov <vdavydov@parallels.com>,
        "Eric W. Biederman" <ebiederm@xmission.com>,
        Casey Schaufler <casey@schaufler-ca.com>,
        LKML <linux-kernel@vger.kernel.org>,
        "open list:ABI/API" <linux-api@vger.kernel.org>,
        linux-security-module@vger.kernel.org,
        Linux Containers <containers@lists.linux-foundation.org>,
        Lukasz Pawelczyk <havner@gmail.com>
Date: Thu, 27 Nov 2014 16:24:22 +0100
In-reply-to: <547740A0.4040700@nod.at>
References: <1417096866-25563-1-git-send-email-l.pawelczyk@samsung.com>
 <1417096866-25563-2-git-send-email-l.pawelczyk@samsung.com>
 <CAFLxGvzw4N4QFv5Vg1dDf9pdRe+Szbevmqn5QNwjLHN4xrokCg@mail.gmail.com>
 <1417098928.1805.15.camel@samsung.com> <54773757.8090905@nod.at>
 <1417099455.1805.17.camel@samsung.com> <54773CE7.5040303@nod.at>
 <1417101060.1805.21.camel@samsung.com> <547740A0.4040700@nod.at>
Content-type: text/plain; charset=UTF-8
MIME-version: 1.0
Content-transfer-encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org

On czw, 2014-11-27 at 16:17 +0100, Richard Weinberger wrote:
> Am 27.11.2014 um 16:11 schrieb Lukasz Pawelczyk:
> > On czw, 2014-11-27 at 16:01 +0100, Richard Weinberger wrote:
> >> Am 27.11.2014 um 15:44 schrieb Lukasz Pawelczyk:
> >>> True, the last one is 0x80000000. I did not notice that. Thanks for
> >>> pointing out.
> >>
> >> Isn't this CLONE_IO?
> > 
> > Yes, I was merely noticing out loud that it's the last bit of 32bit.
> > 
> > After close look though the 0x00001000 appears to be unused
> 
> This was CLONE_PID.
> I'm not sure if we can reuse this. man 2 clone states "It disappeared in Linux 2.5.16.".
> Maybe one of the CC'd parties can tell more...

Would really like someone to comment on this. I'd like to avoid creating
a new syscall at this point.

According to clone(2):
CLONE_STOPPED has been removed in 2.6.38 and can be reused.
CLONE_PID as you mentioned has been removed in 2.5.16 but since 2.3.21
it could only be used by boot process (PID 0).

So this was really long time ago and effectively regular user space
cannot use it since 2.3.21.


-- 
Lukasz Pawelczyk
Samsung R&D Institute Poland
Samsung Electronics


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/