From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with ESMTP id C437F6B0203 for ; Tue, 13 Apr 2010 00:31:55 -0400 (EDT) Date: Mon, 12 Apr 2010 21:29:13 -0400 From: Andrew Morton Subject: Re: [PATCH 67 of 67] memcg fix prepare migration Message-Id: <20100412212913.55be5ce5.akpm@linux-foundation.org> In-Reply-To: <20100408125722.2a11257d.nishimura@mxp.nes.nec.co.jp> References: <545969ff079730c4d7f7.1270691510@v2.random> <20100408125722.2a11257d.nishimura@mxp.nes.nec.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Daisuke Nishimura Cc: Andrea Arcangeli , linux-mm@kvack.org, Marcelo Tosatti , Adam Litke , Avi Kivity , Izik Eidus , Hugh Dickins , Nick Piggin , Rik van Riel , Mel Gorman , Dave Hansen , Benjamin Herrenschmidt , Ingo Molnar , Mike Travis , KAMEZAWA Hiroyuki , Christoph Lameter , Chris Wright , bpicco@redhat.com, KOSAKI Motohiro , Balbir Singh , Arnd Bergmann , "Michael S. Tsirkin" , Peter Zijlstra , Johannes Weiner , Chris Mason , stable@kernel.org List-ID: On Thu, 8 Apr 2010 12:57:22 +0900 Daisuke Nishimura wrote: > On Thu, 08 Apr 2010 03:51:50 +0200, Andrea Arcangeli wrote: > > From: Andrea Arcangeli > > > > If a signal is pending (task being killed by sigkill) __mem_cgroup_try_charge > > will write NULL into &mem, and css_put will oops on null pointer dereference. > > > > BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 > > IP: [] mem_cgroup_prepare_migration+0x7c/0xc0 > > PGD a5d89067 PUD a5d8a067 PMD 0 > > Oops: 0000 [#1] SMP > > last sysfs file: /sys/devices/platform/microcode/firmware/microcode/loading > > CPU 0 > > Modules linked in: nfs lockd nfs_acl auth_rpcgss sunrpc acpi_cpufreq pcspkr sg [last unloaded: microcode] > > > > Pid: 5299, comm: largepages Tainted: G W 2.6.34-rc3 #3 Penryn1600SLI-110dB/To Be Filled By O.E.M. > > RIP: 0010:[] [] mem_cgroup_prepare_migration+0x7c/0xc0 > > > > Signed-off-by: Andrea Arcangeli > Nice catch ! > > But I think this fix should be forwarded to 34-rc and stable. They all have > the same problem if the "current" which is doing the page migration is being > oom-killed. OK. I added the cc:stable. The patch gets a trivial reject vs 2.6.33, but they'll work it out ;) -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org