Re: [PATCH] PM / Hibernate: Fix memory corruption related to swap

KAMEZAWA Hiroyuki
2010-12-03T00:21:03Z

On Fri, 3 Dec 2010 00:40:36 +0100
"Rafael J. Wysocki" <rjw@sisk.pl> wrote:

> From: Rafael J. Wysocki <rjw@sisk.pl>
>
> There is a problem that swap pages allocated before the creation of
> a hibernation image can be released and used for storing the contents
> of different memory pages while the image is being saved. Since the
> kernel stored in the image doesn't know of that, it causes memory
> corruption to occur after resume from hibernation, especially on
> systems with relatively small RAM that need to swap often.
>
> This issue can be addressed by keeping the GFP_IOFS bits clear
> in gfp_allowed_mask during the entire hibernation, including the
> saving of the image, until the system is finally turned off or
> the hibernation is aborted. Unfortunately, for this purpose
> it's necessary to rework the way in which the hibernate and
> suspend code manipulates gfp_allowed_mask.
>
> This change is based on an earlier patch from Hugh Dickins.
>
> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
> Reported-by: Ondrej Zary <linux@rainbow-software.org>
> Acked-by: Hugh Dickins <hughd@google.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>

Thanks,
-Kame