From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chanwoo Choi Subject: Re: [PATCH] PM / devfreq: use put_device() instead of kfree() Date: Fri, 13 Apr 2018 10:13:01 +0900 Message-ID: <5AD0041D.2050506@samsung.com> References: <5AD001C5.2040406@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8BIT Return-path: In-reply-to: <5AD001C5.2040406@samsung.com> Sender: linux-kernel-owner@vger.kernel.org To: Arvind Yadav , myungjoo.ham@samsung.com, kyungmin.park@samsung.com Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org List-Id: linux-pm@vger.kernel.org On 2018년 04월 13일 10:03, Chanwoo Choi wrote: > Hi, > > I'm sorry for the late reply. > > On 2018년 03월 30일 20:44, Arvind Yadav wrote: >> Never directly free @dev after calling device_register() or >> device_unregister(), even if device_register() returned an error. >> Always use put_device() to give up the reference initialized. >> >> Signed-off-by: Arvind Yadav >> --- >> drivers/devfreq/devfreq.c | 4 +++- >> 1 file changed, 3 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c >> index fe2af6a..a225b94 100644 >> --- a/drivers/devfreq/devfreq.c >> +++ b/drivers/devfreq/devfreq.c >> @@ -625,7 +625,8 @@ struct devfreq *devfreq_add_device(struct device *dev, >> err = device_register(&devfreq->dev); >> if (err) { >> mutex_unlock(&devfreq->lock); >> - goto err_dev; >> + put_device(&devfreq->dev); >> + goto err_out; > > why do you change the goto postion? > err_out is correct to free the memory of devfreq instance. Sorry. err_dev is correct instead of err_out. > >> } >> >> devfreq->trans_table = devm_kzalloc(&devfreq->dev, >> @@ -671,6 +672,7 @@ struct devfreq *devfreq_add_device(struct device *dev, >> mutex_unlock(&devfreq_list_lock); >> >> device_unregister(&devfreq->dev); >> + devfreq = NULL; > > It is wrong. If you initialize the devfreq as NULL, > never free the 'devfreq' instance. > >> err_dev: >> if (devfreq) >> kfree(devfreq); >> > > -- Best Regards, Chanwoo Choi Samsung Electronics