[PATCH] drm/vc4: clean up error handling on devm_kzalloc failure

[PATCH] drm/vc4: clean up error handling on devm_kzalloc failure

[Colin King]

From: Colin Ian King <colin.king@canonical.com>

The current error handling on devm_kzalloc failures performs a non-null
check on connector. Thss check is redundant because connector is null
at that failure point.  With this check removed, we may as well make
the failure path into a trivial -ENOMEM return to clean up the error
handling.

Detected by CoverityScan CID#1339527 ("Logically dead code")

Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/gpu/drm/vc4/vc4_hdmi.c | 13 ++-----------
 1 file changed, 2 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index 937da8dd65b8..a8808c1a1e03 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -311,14 +311,11 @@ static struct drm_connector *vc4_hdmi_connector_init(struct drm_device *dev,
 {
 	struct drm_connector *connector = NULL;
 	struct vc4_hdmi_connector *hdmi_connector;
-	int ret = 0;
 
 	hdmi_connector = devm_kzalloc(dev->dev, sizeof(*hdmi_connector),
 				      GFP_KERNEL);
-	if (!hdmi_connector) {
-		ret = -ENOMEM;
-		goto fail;
-	}
+	if (!hdmi_connector)
+		return ERR_PTR(-ENOMEM);
 	connector = &hdmi_connector->base;
 
 	hdmi_connector->encoder = encoder;
@@ -336,12 +333,6 @@ static struct drm_connector *vc4_hdmi_connector_init(struct drm_device *dev,
 	drm_mode_connector_attach_encoder(connector, encoder);
 
 	return connector;
-
- fail:
-	if (connector)
-		vc4_hdmi_connector_destroy(connector);
-
-	return ERR_PTR(ret);
 }
 
 static void vc4_hdmi_encoder_destroy(struct drm_encoder *encoder)
-- 
2.14.1

Re: [PATCH] drm/vc4: clean up error handling on devm_kzalloc failure

[Eric Engestrom]

On Friday, 2017-09-08 14:17:04 +0100, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
> 
> The current error handling on devm_kzalloc failures performs a non-null
> check on connector. Thss check is redundant because connector is null
> at that failure point.  With this check removed, we may as well make
> the failure path into a trivial -ENOMEM return to clean up the error
> handling.
> 
> Detected by CoverityScan CID#1339527 ("Logically dead code")
> 
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>  drivers/gpu/drm/vc4/vc4_hdmi.c | 13 ++-----------
>  1 file changed, 2 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
> index 937da8dd65b8..a8808c1a1e03 100644
> --- a/drivers/gpu/drm/vc4/vc4_hdmi.c
> +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
> @@ -311,14 +311,11 @@ static struct drm_connector *vc4_hdmi_connector_init(struct drm_device *dev,
>  {
>  	struct drm_connector *connector = NULL;

This `= NULL` isn't needed anymore either.

Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com>

>  	struct vc4_hdmi_connector *hdmi_connector;
> -	int ret = 0;
>  
>  	hdmi_connector = devm_kzalloc(dev->dev, sizeof(*hdmi_connector),
>  				      GFP_KERNEL);
> -	if (!hdmi_connector) {
> -		ret = -ENOMEM;
> -		goto fail;
> -	}
> +	if (!hdmi_connector)
> +		return ERR_PTR(-ENOMEM);
>  	connector = &hdmi_connector->base;
>  
>  	hdmi_connector->encoder = encoder;
> @@ -336,12 +333,6 @@ static struct drm_connector *vc4_hdmi_connector_init(struct drm_device *dev,
>  	drm_mode_connector_attach_encoder(connector, encoder);
>  
>  	return connector;
> -
> - fail:
> -	if (connector)
> -		vc4_hdmi_connector_destroy(connector);
> -
> -	return ERR_PTR(ret);
>  }
>  
>  static void vc4_hdmi_encoder_destroy(struct drm_encoder *encoder)
> -- 
> 2.14.1
> 

Re: [PATCH] drm/vc4: clean up error handling on devm_kzalloc failure

[Emil Velikov]

Hi Colin,

On 8 September 2017 at 14:17, Colin King <colin.king@canonical.com> wrote:
> From: Colin Ian King <colin.king@canonical.com>
>
> The current error handling on devm_kzalloc failures performs a non-null
> check on connector. Thss check is redundant because connector is null
> at that failure point.  With this check removed, we may as well make
> the failure path into a trivial -ENOMEM return to clean up the error
> handling.
>
> Detected by CoverityScan CID#1339527 ("Logically dead code")
>
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>  drivers/gpu/drm/vc4/vc4_hdmi.c | 13 ++-----------
>  1 file changed, 2 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
> index 937da8dd65b8..a8808c1a1e03 100644
> --- a/drivers/gpu/drm/vc4/vc4_hdmi.c
> +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
> @@ -311,14 +311,11 @@ static struct drm_connector *vc4_hdmi_connector_init(struct drm_device *dev,
>  {
>         struct drm_connector *connector = NULL;
I think you can drop the initializer now.

-Emil

Re: [PATCH] drm/vc4: clean up error handling on devm_kzalloc failure

[Eric Anholt]

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Colin King <colin.king@canonical.com> writes:

> From: Colin Ian King <colin.king@canonical.com>
>
> The current error handling on devm_kzalloc failures performs a non-null
> check on connector. Thss check is redundant because connector is null
> at that failure point.  With this check removed, we may as well make
> the failure path into a trivial -ENOMEM return to clean up the error
> handling.
>
> Detected by CoverityScan CID#1339527 ("Logically dead code")

Reviewed and applied.  Thanks!

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