From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Serge E. Hallyn" Subject: Re: [Patch resend v3 3/3] binfmt_misc: add F option description to documentation Date: Tue, 19 Apr 2016 14:58:32 -0500 Message-ID: <20160419195832.GA32382@mail.hallyn.com> References: <1461068670.2435.0.camel@HansenPartnership.com> <1461068980.2435.6.camel@HansenPartnership.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1461068980.2435.6.camel-d9PhHud1JfjCXq6kfMZ53/egYHeGw8Jk@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: James Bottomley Cc: linux-fsdevel , containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, Jan Kara , Al Viro List-Id: containers.vger.kernel.org Quoting James Bottomley (James.Bottomley-d9PhHud1JfjCXq6kfMZ53/egYHeGw8Jk@public.gmane.org): > Signed-off-by: James Bottomley Acked-by: Serge Hallyn Thanks, James. Which tree were you thinking this would go in through? > --- > Documentation/binfmt_misc.txt | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/Documentation/binfmt_misc.txt b/Documentation/binfmt_misc.txt > index 6b1de70..ec83bbc 100644 > --- a/Documentation/binfmt_misc.txt > +++ b/Documentation/binfmt_misc.txt > @@ -66,6 +66,13 @@ Here is what the fields mean: > This feature should be used with care as the interpreter > will run with root permissions when a setuid binary owned by root > is run with binfmt_misc. > + 'F' - fix binary. The usual behaviour of binfmt_misc is to spawn the > + binary lazily when the misc format file is invoked. However, > + this doesn't work very well in the face of mount namespaces and > + changeroots, so the F mode opens the binary as soon as the > + emulation is installed and uses the opened image to spawn the > + emulator, meaning it is always available once installed, > + regardless of how the environment changes. > > > There are some restrictions: > -- > 2.6.6 > > _______________________________________________ > Containers mailing list > Containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org > https://lists.linuxfoundation.org/mailman/listinfo/containers From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from h2.hallyn.com ([78.46.35.8]:52294 "EHLO h2.hallyn.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753129AbcDST6f (ORCPT ); Tue, 19 Apr 2016 15:58:35 -0400 Date: Tue, 19 Apr 2016 14:58:32 -0500 From: "Serge E. Hallyn" To: James Bottomley Cc: containers@lists.linux-foundation.org, linux-fsdevel , Jan Kara , Al Viro Subject: Re: [Patch resend v3 3/3] binfmt_misc: add F option description to documentation Message-ID: <20160419195832.GA32382@mail.hallyn.com> References: <1461068670.2435.0.camel@HansenPartnership.com> <1461068980.2435.6.camel@HansenPartnership.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1461068980.2435.6.camel@HansenPartnership.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Quoting James Bottomley (James.Bottomley@HansenPartnership.com): > Signed-off-by: James Bottomley Acked-by: Serge Hallyn Thanks, James. Which tree were you thinking this would go in through? > --- > Documentation/binfmt_misc.txt | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/Documentation/binfmt_misc.txt b/Documentation/binfmt_misc.txt > index 6b1de70..ec83bbc 100644 > --- a/Documentation/binfmt_misc.txt > +++ b/Documentation/binfmt_misc.txt > @@ -66,6 +66,13 @@ Here is what the fields mean: > This feature should be used with care as the interpreter > will run with root permissions when a setuid binary owned by root > is run with binfmt_misc. > + 'F' - fix binary. The usual behaviour of binfmt_misc is to spawn the > + binary lazily when the misc format file is invoked. However, > + this doesn't work very well in the face of mount namespaces and > + changeroots, so the F mode opens the binary as soon as the > + emulation is installed and uses the opened image to spawn the > + emulator, meaning it is always available once installed, > + regardless of how the environment changes. > > > There are some restrictions: > -- > 2.6.6 > > _______________________________________________ > Containers mailing list > Containers@lists.linux-foundation.org > https://lists.linuxfoundation.org/mailman/listinfo/containers