driver core: class: mark the struct class for sysfs callbacks as constant

struct class should never be modified in a sysfs callback as there is
nothing in the structure to modify, and frankly, the structure is almost
never used in a sysfs callback, so mark it as constant to allow struct
class to be moved to read-only memory.

While we are touching all class sysfs callbacks also mark the attribute
as constant as it can not be modified.  The bonding code still uses this
structure so it can not be removed from the function callbacks.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Bartosz Golaszewski <brgl@bgdev.pl>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Russ Weight <russell.h.weight@intel.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Steve French <sfrench@samba.org>
Cc: Vignesh Raghavendra <vigneshr@ti.com>
Cc: linux-cifs@vger.kernel.org
Cc: linux-gpio@vger.kernel.org
Cc: linux-mtd@lists.infradead.org
Cc: linux-rdma@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: netdev@vger.kernel.org
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20230325084537.3622280-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 5 insertions, 4 deletions

diff --git a/include/linux/device/class.h b/include/linux/device/class.h
index 73436c578d37..b53728ca56fb 100644
--- a/include/linux/device/class.h
+++ b/include/linux/device/class.h
@@ -174,10 +174,10 @@ static inline struct device *class_find_device_by_acpi_dev(const struct class *c
 
 struct class_attribute {
 	struct attribute attr;
-	ssize_t (*show)(struct class *class, struct class_attribute *attr,
+	ssize_t (*show)(const struct class *class, const struct class_attribute *attr,
 			char *buf);
-	ssize_t (*store)(struct class *class, struct class_attribute *attr,
-			const char *buf, size_t count);
+	ssize_t (*store)(const struct class *class, const struct class_attribute *attr,
+			 const char *buf, size_t count);
 };
 
 #define CLASS_ATTR_RW(_name) \
@@ -217,7 +217,8 @@ struct class_attribute_string {
 	struct class_attribute_string class_attr_##_name = \
 		_CLASS_ATTR_STRING(_name, _mode, _str)
 
-ssize_t show_class_attr_string(struct class *class, struct class_attribute *attr, char *buf);
+ssize_t show_class_attr_string(const struct class *class, const struct class_attribute *attr,
+			       char *buf);
 
 struct class_interface {
 	struct list_head	node;