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Date: Mon, 17 Oct 2011 20:55:26 +0200
From: Oleg Nesterov <oleg@redhat.com>
To: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Eric Paris <eparis@parisplace.org>, Ingo Molnar <mingo@elte.hu>,
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        Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>,
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        Andrew Morton <akpm@linux-foundation.org>,
        Jim Keniston <jkenisto@linux.vnet.ibm.com>,
        Roland McGrath <roland@hack.frob.com>,
        LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 6/X] uprobes: reimplement xol_add_vma() via
	install_special_mapping()
Message-ID: <20111017185526.GA9244@redhat.com>
References: <20110920115938.25326.93059.sendpatchset@srdronam.in.ibm.com> <20111015190007.GA30243@redhat.com> <20111016161359.GA24893@redhat.com> <20111017105054.GC11831@linux.vnet.ibm.com> <1318858455.7251.12.camel@moss-pluto>
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On 10/17, Stephen Smalley wrote:
>
> > Since selinux wasnt happy to have an anonymous vma attached, we would
> > create a pseudo file using shmem_file_setup. However after comments from
> > Peter and Stephan's suggestions we started using override_creds. Peter and
> > Oleg suggest that we use install_special_mapping.
> >
> > Are you okay with using install_special_mapping instead of
> > override_creds()?
>
> That's fine with me.

Good.

> But I'm still not clear on how you are controlling
> the use of this facility from userspace, which is my primary concern.

Yes, but just in case... Any security check in xol_add_vma() is pointless.
The task is already "owned" by uprobes when xol_add_vma() is called.

Oleg.