[PATCH 0/3] driver core: make struct device_driver and bus_type groups members constant arrays

[PATCH 0/3] driver core: make struct device_driver and bus_type groups members constant arrays

[Heiner Kallweit]

This series constifies the attribute group groups arrays in struct
device_driver and bus_type, allowing to assign constant arrays.

Heiner Kallweit (3):
  driver core: constify group arrays arguments in driver_add_groups and
    driver_remove_groups
  driver core: make struct bus_type groups members constant arrays
  device core: make struct device_driver groups members constant arrays

 drivers/base/base.h           | 6 ++++--
 drivers/base/driver.c         | 4 ++--
 include/linux/device/bus.h    | 6 +++---
 include/linux/device/driver.h | 4 ++--
 4 files changed, 11 insertions(+), 9 deletions(-)

-- 
2.53.0

[PATCH 1/3] driver core: constify group arrays arguments in driver_add_groups and driver_remove_groups

[Heiner Kallweit]

Constify the groups array argument in driver_add_groups and
driver_remove_groups. This allows to pass constant arrays as
arguments.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
 drivers/base/base.h   | 6 ++++--
 drivers/base/driver.c | 4 ++--
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/base/base.h b/drivers/base/base.h
index 3bc8e6fd0..747530465 100644
--- a/drivers/base/base.h
+++ b/drivers/base/base.h
@@ -196,8 +196,10 @@ static inline void dev_sync_state(struct device *dev)
 		dev->driver->sync_state(dev);
 }
 
-int driver_add_groups(const struct device_driver *drv, const struct attribute_group **groups);
-void driver_remove_groups(const struct device_driver *drv, const struct attribute_group **groups);
+int driver_add_groups(const struct device_driver *drv,
+		      const struct attribute_group *const *groups);
+void driver_remove_groups(const struct device_driver *drv,
+			  const struct attribute_group *const *groups);
 void device_driver_detach(struct device *dev);
 
 static inline void device_set_driver(struct device *dev, const struct device_driver *drv)
diff --git a/drivers/base/driver.c b/drivers/base/driver.c
index 8ab010ddf..c5ebf1fda 100644
--- a/drivers/base/driver.c
+++ b/drivers/base/driver.c
@@ -203,13 +203,13 @@ void driver_remove_file(const struct device_driver *drv,
 EXPORT_SYMBOL_GPL(driver_remove_file);
 
 int driver_add_groups(const struct device_driver *drv,
-		      const struct attribute_group **groups)
+		      const struct attribute_group *const *groups)
 {
 	return sysfs_create_groups(&drv->p->kobj, groups);
 }
 
 void driver_remove_groups(const struct device_driver *drv,
-			  const struct attribute_group **groups)
+			  const struct attribute_group *const *groups)
 {
 	sysfs_remove_groups(&drv->p->kobj, groups);
 }
-- 
2.53.0

Re: [PATCH 1/3] driver core: constify group arrays arguments in driver_add_groups and driver_remove_groups

[Greg Kroah-Hartman]

On Mon, Mar 16, 2026 at 11:09:37PM +0100, Heiner Kallweit wrote:
> Constify the groups array argument in driver_add_groups and
> driver_remove_groups. This allows to pass constant arrays as
> arguments.

But do we?  How down the * const depth do we want to go?  :)

And does any of this series require any other fixups?  If not, does it
actually do anything?

thanks,

greg k-h

Re: [PATCH 1/3] driver core: constify group arrays arguments in driver_add_groups and driver_remove_groups

[Heiner Kallweit]

On 02.04.2026 17:11, Greg Kroah-Hartman wrote:
> On Mon, Mar 16, 2026 at 11:09:37PM +0100, Heiner Kallweit wrote:
>> Constify the groups array argument in driver_add_groups and
>> driver_remove_groups. This allows to pass constant arrays as
>> arguments.
> 
> But do we?  How down the * const depth do we want to go?  :)
> 
Not yet, but this is the next step. __ATTRIBUTE_GROUPS() would be
complemented by a version creating a constant array. If something
that de-facto is constant, lives in .rodata, then that's a good
thing IMO.

> And does any of this series require any other fixups?  If not, does it
> actually do anything?
> 
According to my checks no fixups are needed. And so far no CI
complained about the series, what I interpret as a positive sign.
This series doesn't do anything, it's a prerequisite for changes
like the one described in aforementioned comment.

> thanks,
> 
> greg k-h

Heiner

[PATCH 2/3] driver core: make struct bus_type groups members constant arrays

[Heiner Kallweit]

Constify the groups arrays, allowing to assign constant arrays.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
 include/linux/device/bus.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/linux/device/bus.h b/include/linux/device/bus.h
index 63de5f053..c6a3e16b7 100644
--- a/include/linux/device/bus.h
+++ b/include/linux/device/bus.h
@@ -80,9 +80,9 @@ struct fwnode_handle;
 struct bus_type {
 	const char		*name;
 	const char		*dev_name;
-	const struct attribute_group **bus_groups;
-	const struct attribute_group **dev_groups;
-	const struct attribute_group **drv_groups;
+	const struct attribute_group *const *bus_groups;
+	const struct attribute_group *const *dev_groups;
+	const struct attribute_group *const *drv_groups;
 
 	int (*match)(struct device *dev, const struct device_driver *drv);
 	int (*uevent)(const struct device *dev, struct kobj_uevent_env *env);
-- 
2.53.0

[PATCH 3/3] device core: make struct device_driver groups members constant arrays

[Heiner Kallweit]

Constify the groups arrays, allowing to assign constant arrays.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
 include/linux/device/driver.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/linux/device/driver.h b/include/linux/device/driver.h
index bbc67ec51..c882daaef 100644
--- a/include/linux/device/driver.h
+++ b/include/linux/device/driver.h
@@ -114,8 +114,8 @@ struct device_driver {
 	void (*shutdown) (struct device *dev);
 	int (*suspend) (struct device *dev, pm_message_t state);
 	int (*resume) (struct device *dev);
-	const struct attribute_group **groups;
-	const struct attribute_group **dev_groups;
+	const struct attribute_group *const *groups;
+	const struct attribute_group *const *dev_groups;
 
 	const struct dev_pm_ops *pm;
 	void (*coredump) (struct device *dev);
-- 
2.53.0