2022-10-11 07:59:45

by Aashish Sharma

Subject: [PATCH] drm/msm: Remove redundant check for 'submit'

Rectify the below smatch warning:
drivers/gpu/drm/msm/msm_gem_submit.c:963 msm_ioctl_gem_submit() warn:
variable dereferenced before check 'submit'

'submit' is normally error pointer or valid, so remove its NULL
initializer as it's confusing and also remove a redundant check for it's
value.

Signed-off-by: Aashish Sharma <[email protected]>
Reported-by: kernel test robot <[email protected]>
Reported-by: Dan Carpenter <[email protected]>
---
drivers/gpu/drm/msm/msm_gem_submit.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c
index 5599d93ec0d2..74fe1c56cd65 100644
--- a/drivers/gpu/drm/msm/msm_gem_submit.c
+++ b/drivers/gpu/drm/msm/msm_gem_submit.c
@@ -706,7 +706,7 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
struct msm_drm_private *priv = dev->dev_private;
struct drm_msm_gem_submit *args = data;
struct msm_file_private *ctx = file->driver_priv;
- struct msm_gem_submit *submit = NULL;
+ struct msm_gem_submit *submit;
struct msm_gpu *gpu = priv->gpu;
struct msm_gpu_submitqueue *queue;
struct msm_ringbuffer *ring;
@@ -946,8 +946,7 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
put_unused_fd(out_fence_fd);
mutex_unlock(&queue->lock);
out_post_unlock:
- if (submit)
- msm_gem_submit_put(submit);
+ msm_gem_submit_put(submit);
if (!IS_ERR_OR_NULL(post_deps)) {
for (i = 0; i < args->nr_out_syncobjs; ++i) {
kfree(post_deps[i].chain);
--
2.38.0.rc2.412.g84df46c1b4-goog

2022-10-11 16:11:59

by Guenter Roeck

Subject: Re: [PATCH] drm/msm: Remove redundant check for 'submit'

On Tue, Oct 11, 2022 at 12:55 AM Aashish Sharma <[email protected]> wrote:
>
> Rectify the below smatch warning:
> drivers/gpu/drm/msm/msm_gem_submit.c:963 msm_ioctl_gem_submit() warn:
> variable dereferenced before check 'submit'
>
> 'submit' is normally error pointer or valid, so remove its NULL
> initializer as it's confusing and also remove a redundant check for it's
> value.
>
> Signed-off-by: Aashish Sharma <[email protected]>
> Reported-by: kernel test robot <[email protected]>
> Reported-by: Dan Carpenter <[email protected]>

Reviewed-by: Guenter Roeck <[email protected]>

> ---
> drivers/gpu/drm/msm/msm_gem_submit.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c
> index 5599d93ec0d2..74fe1c56cd65 100644
> --- a/drivers/gpu/drm/msm/msm_gem_submit.c
> +++ b/drivers/gpu/drm/msm/msm_gem_submit.c
> @@ -706,7 +706,7 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
> struct msm_drm_private *priv = dev->dev_private;
> struct drm_msm_gem_submit *args = data;
> struct msm_file_private *ctx = file->driver_priv;
> - struct msm_gem_submit *submit = NULL;
> + struct msm_gem_submit *submit;
> struct msm_gpu *gpu = priv->gpu;
> struct msm_gpu_submitqueue *queue;
> struct msm_ringbuffer *ring;
> @@ -946,8 +946,7 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
> put_unused_fd(out_fence_fd);
> mutex_unlock(&queue->lock);
> out_post_unlock:
> - if (submit)
> - msm_gem_submit_put(submit);
> + msm_gem_submit_put(submit);
> if (!IS_ERR_OR_NULL(post_deps)) {
> for (i = 0; i < args->nr_out_syncobjs; ++i) {
> kfree(post_deps[i].chain);
> --
> 2.38.0.rc2.412.g84df46c1b4-goog
>