| Message ID | 20230811062738.1066787-1-anshuman.khandual@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | coresight: etm4x: Ensure valid drvdata and clock before clk_put() | expand |
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. Reviewed-by: James Clark <james.clark@arm.com>
On Fri, 11 Aug 2023 at 07:27, Anshuman Khandual <anshuman.khandual@arm.com> 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; > -- > 2.25.1 > Reviewed-by: Mike Leach <mike.leach@lnaro.org>
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. Cheers Suzuki > > Reviewed-by: James Clark <james.clark@arm.com>
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 ?
On Fri, Aug 11, 2023 at 10:09:43AM +0100, 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. drvdata->pclk can't actually be an error pointer. probe() will correctly not allow that. All the IS_ERR(drvdata->pclk) checks should be removed except for the first check in probe(). There is also no need to check "drvdata->pclk" for NULL because clk_put() accepts NULL pointers. (Returning NULL means the clk subsystem has been disabled deliberately). Also drvdata can't actually be NULL either. regards, dan carpenter
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/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 ? 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.
On 8/11/23 15:44, James Clark wrote: > > > 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/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 ? > > 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. Let's just go with the above change as you had suggested unless there is any particular objection. if (drvdata && !IS_ERR_OR_NULL(drvdata->pclk)) clk_put(drvdata->pclk);
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;
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(-)