From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Srivatsa S. Bhat" Subject: Re: [PATCH] cpufreq: Avoid double kobject_put() for the same kobject in error code path Date: Fri, 02 Aug 2013 12:24:01 +0530 Message-ID: <51FB5789.6030401@linux.vnet.ibm.com> References: <2204970.DYsqYi7YjZ@vostro.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from e28smtp09.in.ibm.com ([122.248.162.9]:35342 "EHLO e28smtp09.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754669Ab3HBG5m (ORCPT ); Fri, 2 Aug 2013 02:57:42 -0400 Received: from /spool/local by e28smtp09.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 2 Aug 2013 12:22:13 +0530 In-Reply-To: <2204970.DYsqYi7YjZ@vostro.rjw.lan> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: "Rafael J. Wysocki" Cc: Linux PM list , cpufreq@vger.kernel.org, LKML , Viresh Kumar On 08/02/2013 03:01 AM, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > > The only case triggering a jump to the err_out_unregister label in > __cpufreq_add_dev() is when cpufreq_add_dev_interface() fails. > However, if cpufreq_add_dev_interface() fails, it calls kobject_put() > for the policy kobject in its error code path and since that causes > the kobject's refcount to become 0, the additional kobject_put() for > the same kobject under err_out_unregister and the > wait_for_completion() following it are pointless, so drop them. > > Signed-off-by: Rafael J. Wysocki Reviewed-by: Srivatsa S. Bhat Regards, Srivatsa S. Bhat > --- > drivers/cpufreq/cpufreq.c | 3 --- > 1 file changed, 3 deletions(-) > > Index: linux-pm/drivers/cpufreq/cpufreq.c > =================================================================== > --- linux-pm.orig/drivers/cpufreq/cpufreq.c > +++ linux-pm/drivers/cpufreq/cpufreq.c > @@ -1109,9 +1109,6 @@ err_out_unregister: > } > write_unlock_irqrestore(&cpufreq_driver_lock, flags); > > - kobject_put(&policy->kobj); > - wait_for_completion(&policy->kobj_unregister); > - > err_set_policy_cpu: > per_cpu(cpufreq_policy_cpu, cpu) = -1; > cpufreq_policy_free(policy); >