On 11/08/2023 10:22, Anshuman Khandual wrote:
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/G4N... 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 ?
I meant that it could be replaced with the single check:
if (drvdata && !IS_ERR_OR_NULL(drvdata->pclk)) clk_put(drvdata->pclk);
As Dan mentions it can't be an error pointer anyway, but leaving it like this could just be considered defensive coding.