From mboxrd@z Thu Jan  1 00:00:00 1970
From: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Subject: Re: cgroup: BUG: unable to handle kernel NULL pointer dereference
Date: Sat, 2 Jan 2016 06:54:37 -0500
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To: Jeremiah Mahler <jmmahler-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Serge Hallyn <serge.hallyn-GeWIH/nMZzLQT0dZR+AlfA@public.gmane.org>, Stephen Rothwell <sfr-3FnU+UHB4dNDw9hX6IcOSA@public.gmane.org>, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org

On Fri, Jan 01, 2016 at 03:40:28PM -0800, Jeremiah Mahler wrote:
> all,
> 
> When running the latest linux-next (20151231) two of my machines
> hang early in the boot sequence.  The initial message is for a
> NULL pointer dereference.
> 
>   BUG: unable to handle kernel NULL pointer dereference at 0000000000000030
> 
> And the RIP line refers to cgroup_path.
> 
>   RIP [<ffffffff810eb178>] cgroup_path+0x30/0x80
> 
> Attached are pictures of the back trace.
> 
> Let me know if I can do anything else to help.  I will investigate the
> problem further if I get a chance.

This is most likely from the recent changes from cgroup ns support.
Reverted the patchset for now as it also introduced a bisectability
issue.  Serge, can you please look into this one?

Thanks.

-- 
tejun