From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756864Ab2C0W3H (ORCPT ); Tue, 27 Mar 2012 18:29:07 -0400 Received: from 50-56-35-84.static.cloud-ips.com ([50.56.35.84]:45703 "EHLO mail.hallyn.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753570Ab2C0W3G (ORCPT ); Tue, 27 Mar 2012 18:29:06 -0400 Date: Tue, 27 Mar 2012 22:29:23 +0000 From: "Serge E. Hallyn" To: Cyrill Gorcunov Cc: Oleg Nesterov , LKML , Andrew Morton , Pavel Emelyanov , "Eric W. Biederman" , "Serge E. Hallyn" Subject: Re: [rfc] fcntl: Add F_GETOWNER_UIDS option Message-ID: <20120327222923.GA31692@mail.hallyn.com> References: <20120326150924.GG19395@moon> <20120326164347.GA24394@redhat.com> <20120326183330.GM19395@moon> <20120327152534.GA18478@redhat.com> <20120327165853.GH11875@moon> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120327165853.GH11875@moon> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Quoting Cyrill Gorcunov (gorcunov@openvz.org): > On Tue, Mar 27, 2012 at 05:25:34PM +0200, Oleg Nesterov wrote: > > user_ns_map_uid() should translate uid_t from one namespace to another, > > in this case the namespace is the same. > > > > user_ns_map_uid(cred->user_ns, cred) must be the identical mapping, > > no matter how we change the implementation. > > > > What I think you need is > > user_ns_map_uid(current_user_ns(), filp->f_owner.cred), the only > > problem is that f_owner.cred doesn't exist. > > > > Hmm, I was confused by likely() in user_ns_map_uid. But indeed, I think > you're so right. Is there some reason why we can't carry f_owner.cred > pointer? We would need that for this, yes. However, Eric is working on a new patchset which changes the cross-userns uid mappings. I think it's worth simply leaving a comment that this will need to be addressed, and leave in the unconverted uid. thanks, -serge