Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751134AbaDOXBa (ORCPT ); Tue, 15 Apr 2014 19:01:30 -0400 Received: from mail-ig0-f180.google.com ([209.85.213.180]:57095 "EHLO mail-ig0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750898AbaDOXB3 (ORCPT ); Tue, 15 Apr 2014 19:01:29 -0400 MIME-Version: 1.0 In-Reply-To: <20140415144324.GJ1863@htj.dyndns.org> References: <1798086.IHnGGWGxmu@daeseok-laptop.cloud.net> <20140415144324.GJ1863@htj.dyndns.org> Date: Wed, 16 Apr 2014 08:01:28 +0900 Message-ID: Subject: Re: [PATCH V3] workqueue: fix double unlock bug From: DaeSeok Youn To: Tejun Heo Cc: =?UTF-8?B?6LWW5rGf5bGx?= , linux-kernel Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Tejun. 2014-04-15 23:43 GMT+09:00 Tejun Heo : > On Tue, Apr 15, 2014 at 08:17:43AM +0900, Daeseok Youn wrote: >> >> Use default pwq when alloc_unbound_pwq() is failed. >> >> And remove "if" condition for whether "pwq" is same as "wq->dfl_pwq" >> when wq_calc_node_cpumask() returns false and just use "goto use_dfl_pwq" >> >> Signed-off-by: Daeseok Youn > > This is an awfully inadequate patch description. Can you change it to > something like the following? OK. I will change the patch description as your comment. > > workqueue: fix bugs in wq_update_unbound_numa() failure path > > wq_update_unbound_numa() failure path has the following two bugs. > > * alloc_unbound_pwq() is called without holding wq->mutex; however, if > the allocation fails, it jumps to out_unlock which tries to unlock > wq->mutex. > > * The function should switch to dfl_pwq on failure but didn't do so > after alloc_unbound_pwq() failure. > > Fix it by regrabbing wq->mutex and jumping to use_dfl_pwq on > alloc_unbound_pwq() failure. > > >> diff --git a/kernel/workqueue.c b/kernel/workqueue.c >> index 0ee63af..0679854 100644 >> --- a/kernel/workqueue.c >> +++ b/kernel/workqueue.c >> @@ -4087,10 +4087,7 @@ static void wq_update_unbound_numa(struct workqueue_struct *wq, int cpu, >> if (cpumask_equal(cpumask, pwq->pool->attrs->cpumask)) >> goto out_unlock; >> } else { >> - if (pwq == wq->dfl_pwq) >> - goto out_unlock; >> - else >> - goto use_dfl_pwq; >> + goto use_dfl_pwq; > > And please put this in a separate patch. Patches which are to be > backported through -stable should be minimal. Also, please update the > comment above to reflect the change. Yes, I will do. Thanks for review. Regards, Daeseok Youn. > > Thanks. > > -- > tejun -- 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/