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SubjectRe: [PATCH v2 1/1] linux/container_of.h: Warn about loss of constness
On Mon, Oct 24, 2022 at 02:16:27PM +0300, Sakari Ailus wrote:
> container_of() casts the original type to another which leads to the loss
> of the const qualifier if it is not specified in the caller-provided type.
> This easily leads to container_of() returning a non-const pointer to a
> const struct which the C compiler does not warn about.

Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> ---
> include/linux/container_of.h | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/include/linux/container_of.h b/include/linux/container_of.h
> index 2f4944b791b81..591db643269aa 100644
> --- a/include/linux/container_of.h
> +++ b/include/linux/container_of.h
> @@ -13,6 +13,7 @@
> * @type: the type of the container struct this is embedded in.
> * @member: the name of the member within the struct.
> *
> + * WARNING: any const qualifier of @ptr is lost.
> */
> #define container_of(ptr, type, member) ({ \
> void *__mptr = (void *)(ptr); \
> --
> 2.30.2
>

--
With Best Regards,
Andy Shevchenko


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