Re: [PATCH] vfio: mdev: make mdev_bus_type const

From: Alex Williamson
Date: Thu Feb 22 2024 - 16:38:49 EST


On Thu, 08 Feb 2024 17:02:04 -0300
"Ricardo B. Marliere" <ricardo@xxxxxxxxxxxx> wrote:

> Now that the driver core can properly handle constant struct bus_type,
> move the mdev_bus_type variable to be a constant structure as well,
> placing it into read-only memory which can not be modified at runtime.
>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Suggested-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Ricardo B. Marliere <ricardo@xxxxxxxxxxxx>
> ---
> drivers/vfio/mdev/mdev_driver.c | 2 +-
> drivers/vfio/mdev/mdev_private.h | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/vfio/mdev/mdev_driver.c b/drivers/vfio/mdev/mdev_driver.c
> index 7825d83a55f8..b98322966b3e 100644
> --- a/drivers/vfio/mdev/mdev_driver.c
> +++ b/drivers/vfio/mdev/mdev_driver.c
> @@ -40,7 +40,7 @@ static int mdev_match(struct device *dev, struct device_driver *drv)
> return 0;
> }
>
> -struct bus_type mdev_bus_type = {
> +const struct bus_type mdev_bus_type = {
> .name = "mdev",
> .probe = mdev_probe,
> .remove = mdev_remove,
> diff --git a/drivers/vfio/mdev/mdev_private.h b/drivers/vfio/mdev/mdev_private.h
> index af457b27f607..63a1316b08b7 100644
> --- a/drivers/vfio/mdev/mdev_private.h
> +++ b/drivers/vfio/mdev/mdev_private.h
> @@ -13,7 +13,7 @@
> int mdev_bus_register(void);
> void mdev_bus_unregister(void);
>
> -extern struct bus_type mdev_bus_type;
> +extern const struct bus_type mdev_bus_type;
> extern const struct attribute_group *mdev_device_groups[];
>
> #define to_mdev_type_attr(_attr) \
>
> ---
> base-commit: 78f70c02bdbccb5e9b0b0c728185d4aeb7044ace
> change-id: 20240208-bus_cleanup-vfio-75a6180b5efe
>
> Best regards,

Applied to vfio next branch for v6.9. Thanks,

Alex