[natty/ti-omap4 CVE 1/1] oom: use pte pages in OOM score

[Colin Ian King]

On 06/02/12 09:37, Andy Whitcroft wrote:
> From: KOSAKI Motohiro<kosaki.motohiro at jp.fujitsu.com>
>
> PTE pages eat up memory just like anything else, but we do not account for
> them in any way in the OOM scores.  They are also _guaranteed_ to get
> freed up when a process is OOM killed, while RSS is not.
>
> Reported-by: Dave Hansen<dave at linux.vnet.ibm.com>
> Signed-off-by: KOSAKI Motohiro<kosaki.motohiro at jp.fujitsu.com>
> Cc: Hugh Dickins<hughd at google.com>
> Cc: KAMEZAWA Hiroyuki<kamezawa.hiroyu at jp.fujitsu.com>
> Cc: Oleg Nesterov<oleg at redhat.com>
> Acked-by: David Rientjes<rientjes at google.com>
> Cc:<stable at kernel.org>		[2.6.36+]
> Signed-off-by: Andrew Morton<akpm at linux-foundation.org>
> Signed-off-by: Linus Torvalds<torvalds at linux-foundation.org>
>
> (cherry picked from commit f755a042d82b51b54f3bdd0890e5ea56c0fb6807)
> CVE-2011-2498
> BugLink: http://bugs.launchpad.net/bugs/922374
> Signed-off-by: Andy Whitcroft<apw at canonical.com>
> ---
>   mm/oom_kill.c |    9 ++++++---
>   1 files changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/mm/oom_kill.c b/mm/oom_kill.c
> index ea16f72..49ea0cc 100644
> --- a/mm/oom_kill.c
> +++ b/mm/oom_kill.c
> @@ -172,10 +172,13 @@ unsigned int oom_badness(struct task_struct *p, struct mem_cgroup *mem,
>
>   	/*
>   	 * The baseline for the badness score is the proportion of RAM that each
> -	 * task's rss and swap space use.
> +	 * task's rss, pagetable and swap space use.
>   	 */
> -	points = (get_mm_rss(p->mm) + get_mm_counter(p->mm, MM_SWAPENTS)) * 1000 /
> -			totalpages;
> +	points = get_mm_rss(p->mm) + p->mm->nr_ptes;
> +	points += get_mm_counter(p->mm, MM_SWAPENTS);
> +
> +	points *= 1000;
> +	points /= totalpages;
>   	task_unlock(p);
>
>   	/*

Makes sense to add in the pte count, and this is cherry pick, so..

Acked-by: Colin King <colin.king at canonical.com>