2017-09-08 13:17:10

by Colin King

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

From: Colin Ian King <[email protected]>

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 <[email protected]>
---
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


2017-09-08 13:45:46

by Emil Velikov

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

Hi Colin,

On 8 September 2017 at 14:17, Colin King <[email protected]> wrote:
> From: Colin Ian King <[email protected]>
>
> 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 <[email protected]>
> ---
> 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

2017-09-08 14:25:33

by Eric Engestrom

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

On Friday, 2017-09-08 14:17:04 +0100, Colin King wrote:
> From: Colin Ian King <[email protected]>
>
> 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 <[email protected]>
> ---
> 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 <[email protected]>

> 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
>

2017-09-08 18:08:23

by Eric Anholt

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

Colin King <[email protected]> writes:

> From: Colin Ian King <[email protected]>
>
> 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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