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Date: Sat, 25 Sep 2010 13:19:28 -0500
From: "Serge E. Hallyn" <serge@hallyn.com>
To: Matt Helsley <matthltc@us.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
        Shailabh Nagar <nagar1234@in.ibm.com>, linux-s390@vger.kernel.org,
        Peter Zijlstra <a.p.zijlstra@chello.nl>,
        Venkatesh Pallipadi <venki@google.com>,
        John stultz <johnstul@us.ibm.com>,
        containers@lists.linux-foundation.org,
        Heiko Carstens <heiko.carstens@de.ibm.com>,
        Oleg Nesterov <oleg@redhat.com>, linux-kernel@vger.kernel.org,
        Suresh Siddha <suresh.b.siddha@intel.com>,
        Martin Schwidefsky <schwidefsky@de.ibm.com>,
        Ingo Molnar <mingo@elte.hu>, holzheu@linux.vnet.ibm.com,
        Thomas Gleixner <tglx@linutronix.de>,
        Balbir Singh <balbir@linux.vnet.ibm.com>
Subject: Re: [RFC][PATCH 00/10] taskstats: Enhancements for precise
 accounting
Message-ID: <20100925181928.GA19611@hallyn.com>
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Quoting Matt Helsley (matthltc@us.ibm.com):
> I don't think even "root" can see/use pids outside its namespace (without

Just to be clear on this, you're right in what you say, but if a task in a child
pidns still has access to the /proc mount of the parent pidns, then it can see
the pids in there, and get information from them, i.e. /proc/pid/maps.  So
in that sense, some people could misinterpret "see/use pids" and think you
weren't right.

-serge