From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754245Ab3FDXLL (ORCPT ); Tue, 4 Jun 2013 19:11:11 -0400 Received: from 1wt.eu ([62.212.114.60]:35495 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753100Ab3FDWma (ORCPT ); Tue, 4 Jun 2013 18:42:30 -0400 Message-Id: <20130604172133.042602242@1wt.eu> User-Agent: quilt/0.48-1 Date: Tue, 04 Jun 2013 19:22:36 +0200 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Marcin Jurkowski , Evgeniy Polyakov , Josh Boyer , Greg Kroah-Hartman , Willy Tarreau Subject: [ 066/184] w1: fix oops when w1_search is called from netlink In-Reply-To: <58df134a4b98edf5b0073e2e1e988fe6@local> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-longterm review patch. If anyone has any objections, please let me know. ------------------ connector From: Marcin Jurkowski commit 9d1817cab2f030f6af360e961cc69bb1da8ad765 upstream. On Sat, Mar 02, 2013 at 10:45:10AM +0100, Sven Geggus wrote: > This is the bad commit I found doing git bisect: > 04f482faf50535229a5a5c8d629cf963899f857c is the first bad commit > commit 04f482faf50535229a5a5c8d629cf963899f857c > Author: Patrick McHardy > Date: Mon Mar 28 08:39:36 2011 +0000 Good job. I was too lazy to bisect for bad commit;) Reading the code I found problematic kthread_should_stop call from netlink connector which causes the oops. After applying a patch, I've been testing owfs+w1 setup for nearly two days and it seems to work very reliable (no hangs, no memleaks etc). More detailed description and possible fix is given below: Function w1_search can be called from either kthread or netlink callback. While the former works fine, the latter causes oops due to kthread_should_stop invocation. This patch adds a check if w1_search is serving netlink command, skipping kthread_should_stop invocation if so. Signed-off-by: Marcin Jurkowski Acked-by: Evgeniy Polyakov Cc: Josh Boyer Tested-by: Sven Geggus Signed-off-by: Greg Kroah-Hartman Signed-off-by: Willy Tarreau --- drivers/w1/w1.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c index acc7e3b..74284bd 100644 --- a/drivers/w1/w1.c +++ b/drivers/w1/w1.c @@ -918,7 +918,8 @@ void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb tmp64 = (triplet_ret >> 2); rn |= (tmp64 << i); - if (kthread_should_stop()) { + /* ensure we're called from kthread and not by netlink callback */ + if (!dev->priv && kthread_should_stop()) { dev_dbg(&dev->dev, "Abort w1_search\n"); return; } -- 1.7.12.2.21.g234cd45.dirty