Re: [PATCH v2 4/4] firmware_loader: fix up to_fw_sysfs() to preserve const

[Rafael J. Wysocki]

On Mon, Dec 5, 2022 at 1:12 PM Greg Kroah-Hartman
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> to_fw_sysfs() was changed in commit 23680f0b7d7f ("driver core: make
> struct class.dev_uevent() take a const *") to pass in a const pointer
> but not pass it back out to handle some changes in the driver core.
> That isn't the best idea as it could cause problems if used incorrectly,
> so switch to use the container_of_const() macro instead which will
> preserve the const status of the pointer and enforce it by the compiler.
>
> Cc: Luis Chamberlain <mcgrof@xxxxxxxxxx>
> Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
> Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
> Acked-by: Russ Weight <russell.h.weight@xxxxxxxxx>
> Fixes: 23680f0b7d7f ("driver core: make struct class.dev_uevent() take a const *")
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

Acked-by: Rafael J. Wysocki <rafael@xxxxxxxxxx>

> ---
> v2: - respin with changed container_of_const() parameters
>
>  drivers/base/firmware_loader/sysfs.h | 6 +-----
>  1 file changed, 1 insertion(+), 5 deletions(-)
>
> diff --git a/drivers/base/firmware_loader/sysfs.h b/drivers/base/firmware_loader/sysfs.h
> index fd0b4ad9bdbb..2060add8ef81 100644
> --- a/drivers/base/firmware_loader/sysfs.h
> +++ b/drivers/base/firmware_loader/sysfs.h
> @@ -80,11 +80,7 @@ struct fw_sysfs {
>         struct firmware *fw;
>         void *fw_upload_priv;
>  };
> -
> -static inline struct fw_sysfs *to_fw_sysfs(const struct device *dev)
> -{
> -       return container_of(dev, struct fw_sysfs, dev);
> -}
> +#define to_fw_sysfs(__dev)     container_of_const(__dev, struct fw_sysfs, dev)
>
>  void __fw_load_abort(struct fw_priv *fw_priv);
>
> --
> 2.38.1
>