vfio: mdev: make mdev_bus_type const

[PATCH] vfio: mdev: make mdev_bus_type const

Posted by Ricardo B. Marliere 2 years ago

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@linuxfoundation.org>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
---
 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,
-- 
Ricardo B. Marliere <ricardo@marliere.net>

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

Posted by Alex Williamson 1 year, 11 months ago

On Thu, 08 Feb 2024 17:02:04 -0300
"Ricardo B. Marliere" <ricardo@marliere.net> 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@linuxfoundation.org>
> Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
> ---
>  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

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

Posted by Jason Gunthorpe 1 year, 12 months ago

On Thu, Feb 08, 2024 at 05:02:04PM -0300, Ricardo B. Marliere 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@linuxfoundation.org>
> Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
> ---
>  drivers/vfio/mdev/mdev_driver.c  | 2 +-
>  drivers/vfio/mdev/mdev_private.h | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Jason

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

Posted by Greg Kroah-Hartman 2 years ago

On Thu, Feb 08, 2024 at 05:02:04PM -0300, Ricardo B. Marliere 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@linuxfoundation.org>
> Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
> ---
>  drivers/vfio/mdev/mdev_driver.c  | 2 +-
>  drivers/vfio/mdev/mdev_private.h | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>