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>

2 files changed, 8 insertions, 9 deletions

diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index 642e3377441a..ba9bbdef9ef5 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -343,7 +343,7 @@ static void class_pktcdvd_release(struct class *cls)
 	kfree(cls);
 }
 
-static ssize_t device_map_show(struct class *c, struct class_attribute *attr,
+static ssize_t device_map_show(const struct class *c, const struct class_attribute *attr,
 			       char *data)
 {
 	int n = 0;
@@ -364,7 +364,7 @@ static ssize_t device_map_show(struct class *c, struct class_attribute *attr,
 }
 static CLASS_ATTR_RO(device_map);
 
-static ssize_t add_store(struct class *c, struct class_attribute *attr,
+static ssize_t add_store(const struct class *c, const struct class_attribute *attr,
 			 const char *buf, size_t count)
 {
 	unsigned int major, minor;
@@ -385,7 +385,7 @@ static ssize_t add_store(struct class *c, struct class_attribute *attr,
 }
 static CLASS_ATTR_WO(add);
 
-static ssize_t remove_store(struct class *c, struct class_attribute *attr,
+static ssize_t remove_store(const struct class *c, const struct class_attribute *attr,
 			    const char *buf, size_t count)
 {
 	unsigned int major, minor;
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index b7bb52f8dfbd..3feadfb96114 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -2424,8 +2424,8 @@ static int zram_remove(struct zram *zram)
  * creates a new un-initialized zram device and returns back this device's
  * device_id (or an error code if it fails to create a new device).
  */
-static ssize_t hot_add_show(struct class *class,
-			struct class_attribute *attr,
+static ssize_t hot_add_show(const struct class *class,
+			const struct class_attribute *attr,
 			char *buf)
 {
 	int ret;
@@ -2438,11 +2438,10 @@ static ssize_t hot_add_show(struct class *class,
 		return ret;
 	return scnprintf(buf, PAGE_SIZE, "%d\n", ret);
 }
-static struct class_attribute class_attr_hot_add =
-	__ATTR(hot_add, 0400, hot_add_show, NULL);
+static CLASS_ATTR_RO(hot_add);
 
-static ssize_t hot_remove_store(struct class *class,
-			struct class_attribute *attr,
+static ssize_t hot_remove_store(const struct class *class,
+			const struct class_attribute *attr,
 			const char *buf,
 			size_t count)
 {