[PATCH] perf: xgene: Remove bogus IS_ERR() check

[PATCH] perf: xgene: Remove bogus IS_ERR() check

[Tai Nguyen]

This patch fixes the warning issue with static checker.
The bug is reported in [1]

[1] https://www.spinics.net/lists/arm-kernel/msg535957.html

Signed-off-by: Tai Nguyen <ttnguyen@apm.com>
---
 drivers/perf/xgene_pmu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/perf/xgene_pmu.c b/drivers/perf/xgene_pmu.c
index c2ac764..a8ac4bc 100644
--- a/drivers/perf/xgene_pmu.c
+++ b/drivers/perf/xgene_pmu.c
@@ -1011,7 +1011,7 @@ xgene_pmu_dev_ctx *acpi_get_pmu_hw_inf(struct xgene_pmu *xgene_pmu,
 	rc = acpi_dev_get_resources(adev, &resource_list,
 				    acpi_pmu_dev_add_resource, &res);
 	acpi_dev_free_resource_list(&resource_list);
-	if (rc < 0 || IS_ERR(&res)) {
+	if (rc < 0) {
 		dev_err(dev, "PMU type %d: No resource address found\n", type);
 		goto err;
 	}
-- 
1.9.1

[PATCH] perf: xgene: Remove bogus IS_ERR() check

[Mark Rutland]

On Wed, Oct 12, 2016 at 09:39:27AM -0700, Tai Nguyen wrote:
> This patch fixes the warning issue with static checker.
> The bug is reported in [1]
> 
> [1] https://www.spinics.net/lists/arm-kernel/msg535957.html
> 
> Signed-off-by: Tai Nguyen <ttnguyen@apm.com>

Please put the problem description in the commit message:

  In acpi_get_pmu_hw_inf we pass the address of a local variable to IS_ERR(),
  which doesn't make sense, as the pointer must be a real, valid pointer. This
  doesn't cause a functional problem, as IS_ERR() will evaluate as false, but
  the check is bogus and causes static checkers to complain.

  Remove the bogus check.

Please also add a Reported-by for Dan.

The patch itself is fine, so with the above, you can add:

Acked-by: Mark Rutland <mark.rutland@arm.com>

Please Cc Will Deacon when sending that, I expect that he will pick it up
(though perhaps not until rc1 given this is not a critical issue).

Thanks,
Mark.

> ---
>  drivers/perf/xgene_pmu.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/perf/xgene_pmu.c b/drivers/perf/xgene_pmu.c
> index c2ac764..a8ac4bc 100644
> --- a/drivers/perf/xgene_pmu.c
> +++ b/drivers/perf/xgene_pmu.c
> @@ -1011,7 +1011,7 @@ xgene_pmu_dev_ctx *acpi_get_pmu_hw_inf(struct xgene_pmu *xgene_pmu,
>  	rc = acpi_dev_get_resources(adev, &resource_list,
>  				    acpi_pmu_dev_add_resource, &res);
>  	acpi_dev_free_resource_list(&resource_list);
> -	if (rc < 0 || IS_ERR(&res)) {
> +	if (rc < 0) {
>  		dev_err(dev, "PMU type %d: No resource address found\n", type);
>  		goto err;
>  	}
> -- 
> 1.9.1
> 

[PATCH] perf: xgene: Remove bogus IS_ERR() check

[Tai Tri Nguyen]

Hi Mark,

On Thu, Oct 13, 2016 at 3:29 AM, Mark Rutland <mark.rutland@arm.com> wrote:
> On Wed, Oct 12, 2016 at 09:39:27AM -0700, Tai Nguyen wrote:
>> This patch fixes the warning issue with static checker.
>> The bug is reported in [1]
>>
>> [1] https://www.spinics.net/lists/arm-kernel/msg535957.html
>>
>> Signed-off-by: Tai Nguyen <ttnguyen@apm.com>
>
> Please put the problem description in the commit message:
>
>   In acpi_get_pmu_hw_inf we pass the address of a local variable to IS_ERR(),
>   which doesn't make sense, as the pointer must be a real, valid pointer. This
>   doesn't cause a functional problem, as IS_ERR() will evaluate as false, but
>   the check is bogus and causes static checkers to complain.
>
>   Remove the bogus check.
>
> Please also add a Reported-by for Dan.
>
> The patch itself is fine, so with the above, you can add:
>
> Acked-by: Mark Rutland <mark.rutland@arm.com>
>
> Please Cc Will Deacon when sending that, I expect that he will pick it up
> (though perhaps not until rc1 given this is not a critical issue).
>

Thanks. I'll send the updated patch shortly.

Regards,
Tai

[...]
>> ---
>>  drivers/perf/xgene_pmu.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/perf/xgene_pmu.c b/drivers/perf/xgene_pmu.c
>> index c2ac764..a8ac4bc 100644
>> --- a/drivers/perf/xgene_pmu.c
>> +++ b/drivers/perf/xgene_pmu.c
>> @@ -1011,7 +1011,7 @@ xgene_pmu_dev_ctx *acpi_get_pmu_hw_inf(struct xgene_pmu *xgene_pmu,
>>       rc = acpi_dev_get_resources(adev, &resource_list,
>>                                   acpi_pmu_dev_add_resource, &res);
>>       acpi_dev_free_resource_list(&resource_list);
>> -     if (rc < 0 || IS_ERR(&res)) {
>> +     if (rc < 0) {
>>               dev_err(dev, "PMU type %d: No resource address found\n", type);
>>               goto err;
>>       }
>> --
>> 1.9.1
>>



-- 
Tai