From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 75E2AC4707F for ; Thu, 27 May 2021 13:50:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 50BB2613BF for ; Thu, 27 May 2021 13:50:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236622AbhE0Nvj (ORCPT ); Thu, 27 May 2021 09:51:39 -0400 Received: from szxga03-in.huawei.com ([45.249.212.189]:2374 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236590AbhE0Nvh (ORCPT ); Thu, 27 May 2021 09:51:37 -0400 Received: from dggeml710-chm.china.huawei.com (unknown [172.30.72.57]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4FrTcZ4xJFz66BM; Thu, 27 May 2021 21:46:22 +0800 (CST) Received: from dggpeml500017.china.huawei.com (7.185.36.243) by dggeml710-chm.china.huawei.com (10.3.17.140) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Thu, 27 May 2021 21:50:00 +0800 Received: from [10.174.178.174] (10.174.178.174) by dggpeml500017.china.huawei.com (7.185.36.243) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Thu, 27 May 2021 21:49:54 +0800 Subject: Re: [PATCH -next] i3c: master: svc: drop free_irq of devm_request_irq allocated irq To: Miquel Raynal CC: , , References: <20210518131127.1308550-1-yangyingliang@huawei.com> <20210527120123.75f2ea09@xps13> From: Yang Yingliang Message-ID: <7052d19a-54cb-d634-f195-dbd8ef37f1e7@huawei.com> Date: Thu, 27 May 2021 21:49:53 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <20210527120123.75f2ea09@xps13> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Originating-IP: [10.174.178.174] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpeml500017.china.huawei.com (7.185.36.243) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 2021/5/27 18:01, Miquel Raynal wrote: > Hi Yang, > > Yang Yingliang wrote on Tue, 18 May 2021 > 21:11:27 +0800: > >> irq allocated with devm_request_irq should not be freed using >> free_irq, because doing so causes a dangling pointer, and a >> subsequent double free. >> >> Reported-by: Hulk Robot >> Signed-off-by: Yang Yingliang >> --- >> drivers/i3c/master/svc-i3c-master.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c >> index 1f6ba4221817..761c9c468357 100644 >> --- a/drivers/i3c/master/svc-i3c-master.c >> +++ b/drivers/i3c/master/svc-i3c-master.c >> @@ -1448,7 +1448,7 @@ static int svc_i3c_master_remove(struct platform_device *pdev) >> if (ret) >> return ret; >> >> - free_irq(master->irq, master); >> + devm_free_irq(&pdev->dev, master->irq, master); > Wouldn't removing this call the right solution? If it's a device > managed resource, it won't probably be needed to free it explicitly in > the remove path. Some drivers would expect to free irq itself, I am not sure if it's ok to remove the free_irq() in i3c, I just keep the original logic here and avoid double free. Thanks, Yang > >> clk_disable_unprepare(master->pclk); >> clk_disable_unprepare(master->fclk); >> clk_disable_unprepare(master->sclk); > Thanks, > Miquèl > .