[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20121214090418.GA6044@redhat.com>
Date: Fri, 14 Dec 2012 09:04:18 +0000
From: "Daniel P. Berrange" <berrange@...hat.com>
To: Neil Horman <nhorman@...driver.com>
Cc: Andrew Morton <akpm@...ux-foundation.org>,
Serge Hallyn <serge.hallyn@...onical.com>,
linux-kernel@...r.kernel.org,
Alexander Viro <viro@...iv.linux.org.uk>,
containers@...ts.linux-foundation.org
Subject: Re: [PATCH] core_pattern: set core helpers root and namespace to
crashing process
On Thu, Dec 13, 2012 at 09:49:39PM -0500, Neil Horman wrote:
> On Thu, Dec 13, 2012 at 02:25:34PM -0800, Andrew Morton wrote:
> > On Thu, 13 Dec 2012 13:12:20 -0500
> > Neil Horman <nhorman@...driver.com> wrote:
> >
> > > On Thu, Dec 13, 2012 at 06:20:48AM -0600, Serge Hallyn wrote:
> > > > Quoting Neil Horman (nhorman@...driver.com):
> > > > > Theres one problem I currently see with it, and that is that I'm not sure we can
> > > > > change the current behavior of how the root fs is set for the pipe reader, lest
> > > > > we break some user space expectations. As such, I've added a sysctl in this
> > > > > patch to allow administrators to globally select if a core reader specified via
> > > > > /proc/sys/kernel/core_pattern should use the global rootfs, or the (possibly)
> > > > > chrooted fs of the crashing process.
> > > >
> > > > Practical question: How is the admin to make an educated decision on
> > > > how to set the sysctl?
> >
> > By reading the documentation which Neil didn't include?
> >
> Yeah, that was stupid of me, I'll respin this with docs.
>
> > > My thought was that the admin typically wouldn't touch this at all. I really
> > > added it as a backwards compatibility option only. Setting the user space
> > > helper task to the root of the crashing parent has the possibility of breaking
> > > existing installs because the core_pattern helper might be expecting global file
> > > system access. Moving forward, my expectation would be that core_pattern
> > > helpers would be written with the default setting in mind, and we could
> > > eventually deprecate the control entirely.
> > >
> > > If you have a better mechanism in mind however (or if you think that removing
> > > the control is a resaonable approach), I'm certainly open to that.
> >
> > Yeah, this is a tiresome patch but I can't think of a better way.
> >
> > Except, perhaps, adding a new token to the core_pattern which says
> > "switch namespaces"?
> >
> I like that idea, perhaps '||' instead of '|' as the leading token can indicate
> "use the namespace root" vs. "use the global root". Thoughts?
That seems like a nicer idea to me, than the extra sysctl knob.
Daniel
--
|: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :|
|: http://libvirt.org -o- http://virt-manager.org :|
|: http://autobuild.org -o- http://search.cpan.org/~danberr/ :|
|: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists