[PATCH 11/12] driver core: device: mark struct class in struct device as constant

From: Greg Kroah-Hartman
Date: Mon Mar 13 2023 - 14:19:14 EST


The pointer to a struct class in a struct device should never be used to
change anything in that class. So mark it as constant to enforce this
requirement.

This requires a few minor changes to some internal driver core functions
to enforce the const * being used here now.

Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/base/core.c | 10 +++++-----
include/linux/device.h | 2 +-
2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index f3b7040ef9b6..0970db630839 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -2820,7 +2820,7 @@ EXPORT_SYMBOL_GPL(devm_device_add_groups);

static int device_add_attrs(struct device *dev)
{
- struct class *class = dev->class;
+ const struct class *class = dev->class;
const struct device_type *type = dev->type;
int error;

@@ -2887,7 +2887,7 @@ static int device_add_attrs(struct device *dev)

static void device_remove_attrs(struct device *dev)
{
- struct class *class = dev->class;
+ const struct class *class = dev->class;
const struct device_type *type = dev->type;

if (dev->physical_location) {
@@ -3120,7 +3120,7 @@ struct kobject *virtual_device_parent(struct device *dev)

struct class_dir {
struct kobject kobj;
- struct class *class;
+ const struct class *class;
};

#define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
@@ -3145,7 +3145,7 @@ static const struct kobj_type class_dir_ktype = {
};

static struct kobject *
-class_dir_create_and_add(struct class *class, struct kobject *parent_kobj)
+class_dir_create_and_add(const struct class *class, struct kobject *parent_kobj)
{
struct class_dir *dir;
int retval;
@@ -4580,7 +4580,7 @@ static int device_attrs_change_owner(struct device *dev, kuid_t kuid,
kgid_t kgid)
{
struct kobject *kobj = &dev->kobj;
- struct class *class = dev->class;
+ const struct class *class = dev->class;
const struct device_type *type = dev->type;
int error;

diff --git a/include/linux/device.h b/include/linux/device.h
index c0c02a00fe87..f97a793c6683 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -629,7 +629,7 @@ struct device {
spinlock_t devres_lock;
struct list_head devres_head;

- struct class *class;
+ const struct class *class;
const struct attribute_group **groups; /* optional groups */

void (*release)(struct device *dev);
--
2.39.2