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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AAA6AC001DB for ; Fri, 11 Aug 2023 09:23:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234722AbjHKJXG (ORCPT ); Fri, 11 Aug 2023 05:23:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44394 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229835AbjHKJXF (ORCPT ); Fri, 11 Aug 2023 05:23:05 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 8DCE2C5 for ; Fri, 11 Aug 2023 02:23:04 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B560ED75; Fri, 11 Aug 2023 02:23:46 -0700 (PDT) Received: from [10.163.54.13] (unknown [10.163.54.13]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D47E03F59C; Fri, 11 Aug 2023 02:22:56 -0700 (PDT) Message-ID: <32017de8-7b92-a88f-0bf6-da1dfe3a7f7d@arm.com> Date: Fri, 11 Aug 2023 14:52:53 +0530 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.13.0 Subject: Re: [PATCH] coresight: etm4x: Ensure valid drvdata and clock before clk_put() Content-Language: en-US To: Suzuki K Poulose , James Clark , linux-arm-kernel@lists.infradead.org Cc: Mike Leach , coresight@lists.linaro.org, linux-kernel@vger.kernel.org, Dan Carpenter References: <20230811062738.1066787-1-anshuman.khandual@arm.com> <07b0dabb-5409-9ba8-543f-aeecafe083e9@arm.com> <72960b11-9e35-a259-3ea6-bae91ff94838@arm.com> From: Anshuman Khandual In-Reply-To: <72960b11-9e35-a259-3ea6-bae91ff94838@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/11/23 14:39, Suzuki K Poulose wrote: > On 11/08/2023 09:39, James Clark wrote: >> >> >> On 11/08/2023 07:27, Anshuman Khandual wrote: >>> This validates 'drvdata' and 'drvdata->pclk' clock before calling clk_put() >>> in etm4_remove_platform_dev(). The problem was detected using Smatch static >>> checker as reported. >>> >>> Cc: Suzuki K Poulose >>> Cc: Mike Leach >>> Cc: James Clark >>> Cc: coresight@lists.linaro.org >>> Cc: linux-arm-kernel@lists.infradead.org >>> Cc: linux-kernel@vger.kernel.org >>> Reported-by: Dan Carpenter >>> Closes: https://lists.linaro.org/archives/list/coresight@lists.linaro.org/thread/G4N6P4OXELPLLQSNU3GU2MR4LOLRXRMJ/ >>> Signed-off-by: Anshuman Khandual >>> --- >>> This applies on coresight-next >>> >>>   drivers/hwtracing/coresight/coresight-etm4x-core.c | 2 +- >>>   1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c >>> index 703b6fcbb6a5..eb412ce302cc 100644 >>> --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c >>> +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c >>> @@ -2269,7 +2269,7 @@ static int __exit etm4_remove_platform_dev(struct platform_device *pdev) >>>           etm4_remove_dev(drvdata); >>>       pm_runtime_disable(&pdev->dev); >>>   -    if (drvdata->pclk) >>> +    if (drvdata && drvdata->pclk && !IS_ERR(drvdata->pclk)) >>>           clk_put(drvdata->pclk); >>>         return 0; >> >> It could be !IS_ERR_OR_NULL(drvdata->pclk), but I wouldn't bother >> changing it at this point. > > +1, please could we have that. Someone else will run a code scanner and > send a patch later. Given this is straight and easy change, lets do it > in the first place. But we already have a drvdata->pclk validation check before IS_ERR(). Would not _OR_NULL be redundant ?