101 lines
4.7 KiB
Diff
101 lines
4.7 KiB
Diff
|
|
Delivered-To: jwboyer@gmail.com
|
|
Received: by 10.220.45.11 with SMTP id c11cs62970vcf;
|
|
Mon, 31 Oct 2011 08:56:49 -0700 (PDT)
|
|
Received: by 10.101.15.19 with SMTP id s19mr2706064ani.103.1320076596057;
|
|
Mon, 31 Oct 2011 08:56:36 -0700 (PDT)
|
|
Return-Path: <linux-kernel-owner@vger.kernel.org>
|
|
Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67])
|
|
by mx.google.com with ESMTP id x8si7676575ani.27.2011.10.31.08.56.32;
|
|
Mon, 31 Oct 2011 08:56:36 -0700 (PDT)
|
|
Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
|
|
Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mail=linux-kernel-owner@vger.kernel.org
|
|
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
|
|
id S934545Ab1JaP4X (ORCPT <rfc822;mel.lkml@gmail.com> + 99 others);
|
|
Mon, 31 Oct 2011 11:56:23 -0400
|
|
Received: from mx1.redhat.com ([209.132.183.28]:23653 "EHLO mx1.redhat.com"
|
|
rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
|
|
id S934538Ab1JaP4X (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
|
|
Mon, 31 Oct 2011 11:56:23 -0400
|
|
Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22])
|
|
by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id p9VFuHOO027543
|
|
(version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK);
|
|
Mon, 31 Oct 2011 11:56:18 -0400
|
|
Received: from dhcp-26-164.brq.redhat.com (dhcp-26-164.brq.redhat.com [10.34.26.164])
|
|
by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id p9VFuEK3018476;
|
|
Mon, 31 Oct 2011 11:56:15 -0400
|
|
From: Frantisek Hrbata <fhrbata@redhat.com>
|
|
To: rientjes@google.com
|
|
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
|
|
akpm@linux-foundation.org, kosaki.motohiro@jp.fujitsu.com,
|
|
oleg@redhat.com, minchan.kim@gmail.com, stable@kernel.org,
|
|
eteo@redhat.com, pmatouse@redhat.com
|
|
Subject: [PATCH v2] oom: fix integer overflow of points in oom_badness
|
|
Date: Mon, 31 Oct 2011 16:56:09 +0100
|
|
Message-Id: <1320076569-23872-1-git-send-email-fhrbata@redhat.com>
|
|
In-Reply-To: <1320048865-13175-1-git-send-email-fhrbata@redhat.com>
|
|
References: <1320048865-13175-1-git-send-email-fhrbata@redhat.com>
|
|
X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22
|
|
Sender: linux-kernel-owner@vger.kernel.org
|
|
Precedence: bulk
|
|
List-ID: <linux-kernel.vger.kernel.org>
|
|
X-Mailing-List: linux-kernel@vger.kernel.org
|
|
|
|
An integer overflow will happen on 64bit archs if task's sum of rss, swapents
|
|
and nr_ptes exceeds (2^31)/1000 value. This was introduced by commit
|
|
|
|
f755a04 oom: use pte pages in OOM score
|
|
|
|
where the oom score computation was divided into several steps and it's no
|
|
longer computed as one expression in unsigned long(rss, swapents, nr_pte are
|
|
unsigned long), where the result value assigned to points(int) is in
|
|
range(1..1000). So there could be an int overflow while computing
|
|
|
|
176 points *= 1000;
|
|
|
|
and points may have negative value. Meaning the oom score for a mem hog task
|
|
will be one.
|
|
|
|
196 if (points <= 0)
|
|
197 return 1;
|
|
|
|
For example:
|
|
[ 3366] 0 3366 35390480 24303939 5 0 0 oom01
|
|
Out of memory: Kill process 3366 (oom01) score 1 or sacrifice child
|
|
|
|
Here the oom1 process consumes more than 24303939(rss)*4096~=92GB physical
|
|
memory, but it's oom score is one.
|
|
|
|
In this situation the mem hog task is skipped and oom killer kills another and
|
|
most probably innocent task with oom score greater than one.
|
|
|
|
The points variable should be of type long instead of int to prevent the int
|
|
overflow.
|
|
|
|
Signed-off-by: Frantisek Hrbata <fhrbata@redhat.com>
|
|
---
|
|
mm/oom_kill.c | 2 +-
|
|
1 files changed, 1 insertions(+), 1 deletions(-)
|
|
|
|
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
|
|
index 626303b..e9a1785 100644
|
|
--- a/mm/oom_kill.c
|
|
+++ b/mm/oom_kill.c
|
|
@@ -162,7 +162,7 @@ static bool oom_unkillable_task(struct task_struct *p,
|
|
unsigned int oom_badness(struct task_struct *p, struct mem_cgroup *mem,
|
|
const nodemask_t *nodemask, unsigned long totalpages)
|
|
{
|
|
- int points;
|
|
+ long points;
|
|
|
|
if (oom_unkillable_task(p, mem, nodemask))
|
|
return 0;
|
|
--
|
|
1.7.6.4
|
|
|
|
--
|
|
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
|
|
the body of a message to majordomo@vger.kernel.org
|
|
More majordomo info at http://vger.kernel.org/majordomo-info.html
|
|
Please read the FAQ at http://www.tux.org/lkml/
|