From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751338AbdKLW2p (ORCPT ); Sun, 12 Nov 2017 17:28:45 -0500 Received: from mailout4.samsung.com ([203.254.224.34]:36449 "EHLO mailout4.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751337AbdKLW2n (ORCPT ); Sun, 12 Nov 2017 17:28:43 -0500 DKIM-Filter: OpenDKIM Filter v2.11.0 mailout4.samsung.com 20171112222841epoutp04901ffe05a87778f56a91a14c3ec138c2~2dyPnp-U92005220052epoutp04J X-AuditID: b6c32a36-325ff70000001039-2f-5a08cb181428 MIME-version: 1.0 Content-transfer-encoding: 8BIT Content-type: text/plain; charset="UTF-8" Message-id: <5A08CB1B.6000201@samsung.com> Date: Mon, 13 Nov 2017 07:28:43 +0900 From: Chanwoo Choi Organization: Samsung Electronics User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 To: "Gustavo A. R. Silva" , MyungJoo Ham , Kyungmin Park Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] PM / devfreq: Remove unnecessary NULL check before kfree In-reply-to: <20171112082739.GA20464@embeddedor.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFnrGKsWRmVeSWpSXmKPExsWy7bCmga7EaY4og+cPBS1WLtnPZnG26Q27 xeVdc9gsPvceYbS43biCzYHVY91BVY++LasYPT5vkgtgjkq1yUhNTEktUkjNS85PycxLt1Xy Do53jjc1MzDUNbS0MFdSyEvMTbVVcvEJ0HXLzAHaqKRQlphTChQKSCwuVtK3synKLy1JVcjI Ly6xVYo2NDTSMzQw1zMyMtIzMY61MjIFKklIzZiwfAdjQTNnxbnNNxgbGDexdzFyckgImEgc Pd/D1MXIxSEksINRYsaFV6wQzndGiR033zDCVP08cZEFxBYS2MAo0dEhCWLzCghK/Jh8DyjO wcEsIC9x5FI2SJhZQFNi6+717BBz7jFKPJk1nRGiXkui9/s5NhCbRUBV4t/bHlYQmw0ovv/F DbA4v4CixNUfj8HqRQUiJHbO/wY2SESgk1Fi6bHd7BAbrCRef+wGs4UF/CWWXu8Ba+AEOvTp xHvMIA0SAmvYJN48amGD+MBFomPCIhYIW1ji1fEt7CBXSwhIS1w6agtR384osXkOyDcgTgej xP2VjawQDcYSp7oamSA280m8+wpyNkgzr0RHmxCE6SHxuqUIotpR4tv2NmiQAs28d/wd6wRG uVlIATYLEWCzkAJsASPzKkax1ILi3PTUYsMCI73ixNzi0rx0veT83E2M4DSmZbaDcdE5n0OM AhyMSjy8EpHsUUKsiWXFlbmHGCU4mJVEeP2eAYV4UxIrq1KL8uOLSnNSiw8xmgLDeyKzlGhy PjDF5pXEG5pYGpiYGQGTl6WhoZI4r+j6axFCAumJJanZqakFqUUwfUwcnFINjC6r7Qzm/Jk8 kacn6aDmqzXMG5k2yz/o1fn+x2by6UkG2suuPDz11Tf6h3nppHOGsbdjKyqK6m+aT/V4v/5w e7JSZIns3siNTz6ZLYtvM74aE2N+IPer/5PyiMZjva3rjQqErOsMeqPcG/1ZdbubZxiEbnm+ vPO0y5YDvO2PHty65/vh3rv210osxRmJhlrMRcWJAHKb/Fl5AwAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrFLMWRmVeSWpSXmKPExsVy+t9jQV3x0xxRBoe32VisXLKfzeJs0xt2 i8u75rBZfO49wmhxu3EFmwOrx7qDqh59W1YxenzeJBfAHMVlk5Kak1mWWqRvl8CVMWH5DsaC Zs6Kc5tvMDYwbmLvYuTkkBAwkfh54iJLFyMXh5DAOkaJCf8aWEESvAKCEj8m3wNKcHAwC8hL HLmUDRJmFlCXmDRvETNE/QNGiQeLTzFD1GtJ9H4/xwZiswioSvx72wM2hw0ovv/FDbA4v4Ci xNUfjxlBZooKREh0n6gEmSMi0M0oMaN1DxvEAiuJ1x+7wY4TFvCV+DPlEtRxnYwSvUuvgRVx Al39dOI95gmMArOQ3DoL4dZZSG5dwMi8ilEytaA4Nz232KjAMC+1XK84Mbe4NC9dLzk/dxMj MIS3Hdbq28F4f0n8IUYBDkYlHt6CaPYoIdbEsuLK3EOMEhzMSiK8fs+AQrwpiZVVqUX58UWl OanFhxilOViUxHlv5x2LFBJITyxJzU5NLUgtgskycXBKNTD27GHIuLueuWp98NQLRuJPb/3f pJZaGPjtzccT87WXS75cccBiJmtJ3p+C6hOMdhMcmn94r7i0a33/1rCCKMOD8ifPGT3LLfNx SQmc2p3pIc3x2Fz67ZV/Z93i+b9cCnD8NNPiU+6G9X/dYov3KfRVNoe9MX7un6Qfu6jq2/O5 7/YHBJXwBf1WYinOSDTUYi4qTgQAPl73VV0CAAA= X-CMS-MailID: 20171112222840epcas1p24ceb7c021375008b8b979d65dde75c45 X-Msg-Generator: CA CMS-TYPE: 101P DLP-Filter: Pass X-CFilter-Loop: Reflected X-CMS-RootMailID: 20171112082944epcas5p216efba5e38d3bf17ee993abe51aa4dc3 X-RootMTR: 20171112082944epcas5p216efba5e38d3bf17ee993abe51aa4dc3 References: <20171112082739.GA20464@embeddedor.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 2017년 11월 12일 17:27, Gustavo A. R. Silva wrote: > NULL check before freeing functions like kfree is not needed. > > This issue was detected with the help of Coccinelle. > > Signed-off-by: Gustavo A. R. Silva > --- > drivers/devfreq/devfreq.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c > index 78fb496..21164a9 100644 > --- a/drivers/devfreq/devfreq.c > +++ b/drivers/devfreq/devfreq.c > @@ -672,8 +672,7 @@ struct devfreq *devfreq_add_device(struct device *dev, > > device_unregister(&devfreq->dev); > err_dev: > - if (devfreq) > - kfree(devfreq); > + kfree(devfreq); > err_out: > return ERR_PTR(err); > } > It prevents the memory leak when the registration of devfreq device is failed. You can check the detailed reason on patch1[1]. [1] PM / devfreq: Fix memory leak when fail to register device - https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9e14de1077e9c34f141cf98bdba60cdd5193d962 -- Best Regards, Chanwoo Choi Samsung Electronics