timer: Switch callback prototype to take struct timer_list * argument

Since all callbacks have been converted, we can switch the core
prototype to "struct timer_list *" now too.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Kees Cook <keescook@chromium.org>

include/linux/timer.h

@@ -17,7 +17,7 @@ struct timer_list {
 	 */
 	struct hlist_node	entry;
 	unsigned long		expires;
-	void			(*function)(unsigned long);
+	void			(*function)(struct timer_list *);
 	u32			flags;
 
 #ifdef CONFIG_LOCKDEP
@@ -63,7 +63,7 @@ struct timer_list {
 
 #define TIMER_TRACE_FLAGMASK	(TIMER_MIGRATING | TIMER_DEFERRABLE | TIMER_PINNED | TIMER_IRQSAFE)
 
-#define TIMER_DATA_TYPE		unsigned long
+#define TIMER_DATA_TYPE		struct timer_list *
 #define TIMER_FUNC_TYPE		void (*)(TIMER_DATA_TYPE)
 
 #define __TIMER_INITIALIZER(_function, _data, _flags) {		\

kernel/time/timer.c

@@ -1284,7 +1284,7 @@ int del_timer_sync(struct timer_list *timer)
 EXPORT_SYMBOL(del_timer_sync);
 #endif
 
-static void call_timer_fn(struct timer_list *timer, void (*fn)(unsigned long))
+static void call_timer_fn(struct timer_list *timer, void (*fn)(struct timer_list *))
 {
 	int count = preempt_count();
 
@@ -1308,7 +1308,7 @@ static void call_timer_fn(struct timer_list *timer, void (*fn)(unsigned long))
 	lock_map_acquire(&lockdep_map);
 
 	trace_timer_expire_entry(timer);
-	fn((TIMER_DATA_TYPE)timer);
+	fn(timer);
 	trace_timer_expire_exit(timer);
 
 	lock_map_release(&lockdep_map);
@@ -1330,7 +1330,7 @@ static void expire_timers(struct timer_base *base, struct hlist_head *head)
 {
 	while (!hlist_empty(head)) {
 		struct timer_list *timer;
-		void (*fn)(unsigned long);
+		void (*fn)(struct timer_list *);
 
 		timer = hlist_entry(head->first, struct timer_list, entry);