leds: triggers: Constify 'struct bin_attribute'

The sysfs core now allows instances of 'struct bin_attribute' to be
moved into read-only memory. Make use of that to protect them against
accidental or malicious modifications.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/r/20241222-sysfs-const-bin_attr-led-v1-1-ecc5212a31fa@weissschuh.net
Signed-off-by: Lee Jones <lee@kernel.org>

drivers/leds/led-class.c

@@ -85,13 +85,13 @@ static ssize_t max_brightness_show(struct device *dev,
 static DEVICE_ATTR_RO(max_brightness);
 
 #ifdef CONFIG_LEDS_TRIGGERS
-static BIN_ATTR(trigger, 0644, led_trigger_read, led_trigger_write, 0);
-static struct bin_attribute *led_trigger_bin_attrs[] = {
+static const BIN_ATTR(trigger, 0644, led_trigger_read, led_trigger_write, 0);
+static const struct bin_attribute *const led_trigger_bin_attrs[] = {
 	&bin_attr_trigger,
 	NULL,
 };
 static const struct attribute_group led_trigger_group = {
-	.bin_attrs = led_trigger_bin_attrs,
+	.bin_attrs_new = led_trigger_bin_attrs,
 };
 #endif
 

drivers/leds/led-triggers.c

@@ -34,7 +34,7 @@ trigger_relevant(struct led_classdev *led_cdev, struct led_trigger *trig)
 }
 
 ssize_t led_trigger_write(struct file *filp, struct kobject *kobj,
-			  struct bin_attribute *bin_attr, char *buf,
+			  const struct bin_attribute *bin_attr, char *buf,
 			  loff_t pos, size_t count)
 {
 	struct device *dev = kobj_to_dev(kobj);
@@ -123,7 +123,7 @@ static int led_trigger_format(char *buf, size_t size,
  * copy it.
  */
 ssize_t led_trigger_read(struct file *filp, struct kobject *kobj,
-			struct bin_attribute *attr, char *buf,
+			const struct bin_attribute *attr, char *buf,
 			loff_t pos, size_t count)
 {
 	struct device *dev = kobj_to_dev(kobj);

drivers/leds/leds.h

@@ -22,10 +22,10 @@ void led_stop_software_blink(struct led_classdev *led_cdev);
 void led_set_brightness_nopm(struct led_classdev *led_cdev, unsigned int value);
 void led_set_brightness_nosleep(struct led_classdev *led_cdev, unsigned int value);
 ssize_t led_trigger_read(struct file *filp, struct kobject *kobj,
-			struct bin_attribute *attr, char *buf,
+			const struct bin_attribute *attr, char *buf,
 			loff_t pos, size_t count);
 ssize_t led_trigger_write(struct file *filp, struct kobject *kobj,
-			struct bin_attribute *bin_attr, char *buf,
+			const struct bin_attribute *bin_attr, char *buf,
 			loff_t pos, size_t count);
 
 extern struct rw_semaphore leds_list_lock;