Messages in this thread | | | Date | Fri, 11 Aug 2023 14:52:53 +0530 | Subject | Re: [PATCH] coresight: etm4x: Ensure valid drvdata and clock before clk_put() | From | Anshuman Khandual <> |
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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 <suzuki.poulose@arm.com> >>> Cc: Mike Leach <mike.leach@linaro.org> >>> Cc: James Clark <james.clark@arm.com> >>> Cc: coresight@lists.linaro.org >>> Cc: linux-arm-kernel@lists.infradead.org >>> Cc: linux-kernel@vger.kernel.org >>> Reported-by: Dan Carpenter <dan.carpenter@linaro.org> >>> Closes: https://lists.linaro.org/archives/list/coresight@lists.linaro.org/thread/G4N6P4OXELPLLQSNU3GU2MR4LOLRXRMJ/ >>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> >>> --- >>> 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 ?
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