drm_aux-dev: fix error handling in drm_dp_aux_dev_init()
diff mbox series

Message ID 1467237135-13075-1-git-send-email-khoroshilov@ispras.ru
State New, archived
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Series
  • drm_aux-dev: fix error handling in drm_dp_aux_dev_init()
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Commit Message

Alexey Khoroshilov June 29, 2016, 9:52 p.m. UTC
If class_create() fails, there is no need for class_destroy().

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
---
 drivers/gpu/drm/drm_dp_aux_dev.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

Comments

Daniel Vetter July 12, 2016, 12:11 p.m. UTC | #1
On Thu, Jun 30, 2016 at 12:52:15AM +0300, Alexey Khoroshilov wrote:
> If class_create() fails, there is no need for class_destroy().
> 
> Found by Linux Driver Verification project (linuxtesting.org).
> 
> Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>

Applied to drm-misc, thanks for the patch. Out of curiosity, how exactly
did you spot this bug?
-Daniel

> ---
>  drivers/gpu/drm/drm_dp_aux_dev.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_dp_aux_dev.c b/drivers/gpu/drm/drm_dp_aux_dev.c
> index 3334baacf43d..734f86a345f6 100644
> --- a/drivers/gpu/drm/drm_dp_aux_dev.c
> +++ b/drivers/gpu/drm/drm_dp_aux_dev.c
> @@ -355,8 +355,7 @@ int drm_dp_aux_dev_init(void)
>  
>  	drm_dp_aux_dev_class = class_create(THIS_MODULE, "drm_dp_aux_dev");
>  	if (IS_ERR(drm_dp_aux_dev_class)) {
> -		res = PTR_ERR(drm_dp_aux_dev_class);
> -		goto out;
> +		return PTR_ERR(drm_dp_aux_dev_class);
>  	}
>  	drm_dp_aux_dev_class->dev_groups = drm_dp_aux_groups;
>  
> -- 
> 1.9.1
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
Alexey Khoroshilov Sept. 23, 2016, 10:26 a.m. UTC | #2
Dear Daniel,

Sorry for long response.

> Applied to drm-misc, thanks for the patch. Out of curiosity, how
> exactly did you spot this bug?

We use static analysis tools that check various rules on correct usage
of kernel core API. An example of error trace for the rm_dp_aux_dev case
you can see here [1].

Some addition details are described in a paper [2].

[1]
http://linuxtesting.org/results/impl_reports_admin?action=preview&num=137
[2]
http://www.ispras.ru/en/publications/configurable_toolset_for_static_verification_of_operating_systems_kernel_modules.pdf


Best regards,
Alexey


On 12.07.2016 14:11, Daniel Vetter wrote:
> On Thu, Jun 30, 2016 at 12:52:15AM +0300, Alexey Khoroshilov wrote:
>> If class_create() fails, there is no need for class_destroy().
>>
>> Found by Linux Driver Verification project (linuxtesting.org).
>>
>> Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
> 
> Applied to drm-misc, thanks for the patch. Out of curiosity, how exactly
> did you spot this bug?
> -Daniel
> 
>> ---
>>  drivers/gpu/drm/drm_dp_aux_dev.c | 3 +--
>>  1 file changed, 1 insertion(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_dp_aux_dev.c b/drivers/gpu/drm/drm_dp_aux_dev.c
>> index 3334baacf43d..734f86a345f6 100644
>> --- a/drivers/gpu/drm/drm_dp_aux_dev.c
>> +++ b/drivers/gpu/drm/drm_dp_aux_dev.c
>> @@ -355,8 +355,7 @@ int drm_dp_aux_dev_init(void)
>>  
>>  	drm_dp_aux_dev_class = class_create(THIS_MODULE, "drm_dp_aux_dev");
>>  	if (IS_ERR(drm_dp_aux_dev_class)) {
>> -		res = PTR_ERR(drm_dp_aux_dev_class);
>> -		goto out;
>> +		return PTR_ERR(drm_dp_aux_dev_class);
>>  	}
>>  	drm_dp_aux_dev_class->dev_groups = drm_dp_aux_groups;
>>  
>> -- 
>> 1.9.1
>>
>> _______________________________________________
>> dri-devel mailing list
>> dri-devel@lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/dri-devel
>

Patch
diff mbox series

diff --git a/drivers/gpu/drm/drm_dp_aux_dev.c b/drivers/gpu/drm/drm_dp_aux_dev.c
index 3334baacf43d..734f86a345f6 100644
--- a/drivers/gpu/drm/drm_dp_aux_dev.c
+++ b/drivers/gpu/drm/drm_dp_aux_dev.c
@@ -355,8 +355,7 @@  int drm_dp_aux_dev_init(void)
 
 	drm_dp_aux_dev_class = class_create(THIS_MODULE, "drm_dp_aux_dev");
 	if (IS_ERR(drm_dp_aux_dev_class)) {
-		res = PTR_ERR(drm_dp_aux_dev_class);
-		goto out;
+		return PTR_ERR(drm_dp_aux_dev_class);
 	}
 	drm_dp_aux_dev_class->dev_groups = drm_dp_aux_groups;