Re: brcmsmac: Drop unnecessary NULL check after container_of

From: Kalle Valo
Date: Tue Jun 15 2021 - 06:43:00 EST


Guenter Roeck <linux@xxxxxxxxxxxx> wrote:

> The parameter passed to ai_detach() is guaranteed to never be NULL
> because it is checked by the caller. Consequently, the result of
> container_of() on it is also never NULL, and a NULL check on it
> is unnecessary. Even without that, the NULL check would still be
> unnecessary because the subsequent kfree() can handle NULL arguments.
> On top of all that, it is misleading to check the result of container_of()
> against NULL because the position of the contained element could change,
> which would make the check invalid. 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 <linux@xxxxxxxxxxxx>

Patch applied to wireless-drivers-next.git, thanks.

34fe7038a3b3 brcmsmac: Drop unnecessary NULL check after container_of

--
https://patchwork.kernel.org/project/linux-wireless/patch/20210511235629.1686038-1-linux@xxxxxxxxxxxx/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches