Date: Sun, 8 Sep 2013 19:00:01 +0200
From: Oleg Nesterov <oleg@redhat.com>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Linux Containers <containers@lists.linux-foundation.org>,
        "Serge E. Hallyn" <serge@hallyn.com>, linux-kernel@vger.kernel.org
Subject: Re: [REVIEW][PATCH 3/5] pidns: Don't have unshare(CLONE_NEWPID)
	imply CLONE_THREAD
Message-ID: <20130908170001.GA1835@redhat.com>
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Sorry for delay, vacation.

On 08/29, Eric W. Biederman wrote:
>
> I goofed when I made unshare(CLONE_NEWPID) only work in a
> single-threaded process.  There is no need for that requirement and in
> fact I analyzied things right for setns.  The hard requirement
> is for tasks that share a VM to all be in the pid namespace and
> we properly prevent that in do_fork.

Yes, agreed, with the current meaning of ->pid_ns unshare(NEWPID)
looks safe even if the caller is multi-threaded... and this matches
pidns_install() which doesn't require single-threaded.

Oleg.

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