Re: [PATCH -stable 1/1] freezer: PF_FREEZER_NOSIG should be cleared along with PF_NOFREEZE

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Fri, Dec 07, 2012 at 03:49:22PM +0100, Oleg Nesterov wrote:
> This patch is only for pre-v3.3 stable trees which backported
> b40a7959 "freezer: exec should clear PF_NOFREEZE along with PF_KTHREAD".
> v3.3+ doesn't need this fix.
> 
> b40a7959 is the trivial bugfix, but unfortunately I forgot that
> until 34b087e4 "freezer: kill unused set_freezable_with_signal()"
> there were another only-for-kernel-threads flag, PF_FREEZER_NOSIG,
> which should be cleared as well.
> 
> See https://bugs.launchpad.net/ubuntu/+source/v86d/+bug/1080530
> The freezer fails because it expects that a PF_FREEZER_NOSIG task
> doesn't need a signal. Before b40a7959 it wrongly succeeds leaving
> the PF_NOFREEZE | PF_FREEZER_NOSIG task unfrozen.
> 
> Reported-and-tested-by: Joseph Salisbury <joseph.salisbury@canonical.com>
> Cc: stable@vger.kernel.org # pre v3.3 if commit b40a7959 was taken

>From what I can tell, 3.0-stable didn't take this patch, so it should be
fine.  Ben, I don't know about 3.2, you should check this.

Oleg, thanks for doing this work, much appreciated.

greg k-h