Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755583Ab3CRVG5 (ORCPT ); Mon, 18 Mar 2013 17:06:57 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:45602 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755528Ab3CRVGz (ORCPT ); Mon, 18 Mar 2013 17:06:55 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Marcin Jurkowski , Evgeniy Polyakov , Josh Boyer , Sven Geggus Subject: [ 35/75] w1: fix oops when w1_search is called from netlink connector Date: Mon, 18 Mar 2013 14:06:58 -0700 Message-Id: <20130318210512.746394425@linuxfoundation.org> X-Mailer: git-send-email 1.8.1.2.434.g9a6c84e.dirty In-Reply-To: <20130318210510.203500214@linuxfoundation.org> References: <20130318210510.203500214@linuxfoundation.org> User-Agent: quilt/0.60-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2143 Lines: 59 3.8-stable review patch. If anyone has any objections, please let me know. ------------------ 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 --- drivers/w1/w1.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/w1/w1.c +++ b/drivers/w1/w1.c @@ -924,7 +924,8 @@ void w1_search(struct w1_master *dev, u8 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()) { mutex_unlock(&dev->bus_mutex); dev_dbg(&dev->dev, "Abort w1_search\n"); return; -- 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/