2021-05-11 04:56:56

by Guenter Roeck

Subject: [PATCH] mei: Drop unnecessary NULL check after container_of

The result of container_of() operations is never NULL unless the embedded
element is the first element of the data structure, which is not the case
here. The NULL check is therefore unnecessary and misleading. Remove it.

This change was made automatically with the following Coccinelle script.

@@
type t;
identifier v;
statement s;
@@

<+...
(
t v = container_of(...);
|
v = container_of(...);
)
...
when != v
- if (\( !v \| v == NULL \) ) s
...+>

Signed-off-by: Guenter Roeck <[email protected]>
---
drivers/misc/mei/main.c | 2 --
1 file changed, 2 deletions(-)

diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c
index 28937b6e7e0c..9001c45f6fc4 100644
--- a/drivers/misc/mei/main.c
+++ b/drivers/misc/mei/main.c
@@ -50,8 +50,6 @@ static int mei_open(struct inode *inode, struct file *file)
int err;

dev = container_of(inode->i_cdev, struct mei_device, cdev);
- if (!dev)
- return -ENODEV;

mutex_lock(&dev->device_lock);

--
2.25.1

2021-05-11 05:18:07

by Tomas Winkler

Subject: RE: [PATCH] mei: Drop unnecessary NULL check after container_of

>
> The result of container_of() operations is never NULL unless the embedded
> element is the first element of the data structure, which is not the case here.
> The NULL check is therefore unnecessary and misleading. Remove it.
>
> This change was made automatically with the following Coccinelle script.
>
> @@
> type t;
> identifier v;
> statement s;
> @@
>
> <+...
> (
> t v = container_of(...);
> |
> v = container_of(...);
> )
> ...
> when != v
> - if (\( !v \| v == NULL \) ) s
> ...+>
>
> Signed-off-by: Guenter Roeck <[email protected]>
Acked-by: Tomas Winkler <[email protected]>
> ---
> drivers/misc/mei/main.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c index
> 28937b6e7e0c..9001c45f6fc4 100644
> --- a/drivers/misc/mei/main.c
> +++ b/drivers/misc/mei/main.c
> @@ -50,8 +50,6 @@ static int mei_open(struct inode *inode, struct file *file)
> int err;
>
> dev = container_of(inode->i_cdev, struct mei_device, cdev);
> - if (!dev)
> - return -ENODEV;
>
> mutex_lock(&dev->device_lock);
>
> --
> 2.25.1