timer: Pass function down to initialization routines

In preparation for removing more macros, pass the function down to the
initialization routines instead of doing it in macros.

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

include/linux/timer.h

@@ -78,53 +78,56 @@ struct timer_list {
 	struct timer_list _name =				\
 		__TIMER_INITIALIZER((TIMER_FUNC_TYPE)_function, 0)
 
-void init_timer_key(struct timer_list *timer, unsigned int flags,
+void init_timer_key(struct timer_list *timer,
+		    void (*func)(struct timer_list *), unsigned int flags,
 		    const char *name, struct lock_class_key *key);
 
 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
 extern void init_timer_on_stack_key(struct timer_list *timer,
+				    void (*func)(struct timer_list *),
 				    unsigned int flags, const char *name,
 				    struct lock_class_key *key);
 extern void destroy_timer_on_stack(struct timer_list *timer);
 #else
 static inline void destroy_timer_on_stack(struct timer_list *timer) { }
 static inline void init_timer_on_stack_key(struct timer_list *timer,
-					   unsigned int flags, const char *name,
+					   void (*func)(struct timer_list *),
+					   unsigned int flags,
+					   const char *name,
 					   struct lock_class_key *key)
 {
-	init_timer_key(timer, flags, name, key);
+	init_timer_key(timer, func, flags, name, key);
 }
 #endif
 
 #ifdef CONFIG_LOCKDEP
-#define __init_timer(_timer, _flags)					\
+#define __init_timer(_timer, _fn, _flags)				\
 	do {								\
 		static struct lock_class_key __key;			\
-		init_timer_key((_timer), (_flags), #_timer, &__key);	\
+		init_timer_key((_timer), (_fn), (_flags), #_timer, &__key);\
 	} while (0)
 
-#define __init_timer_on_stack(_timer, _flags)				\
+#define __init_timer_on_stack(_timer, _fn, _flags)			\
 	do {								\
 		static struct lock_class_key __key;			\
-		init_timer_on_stack_key((_timer), (_flags), #_timer, &__key); \
+		init_timer_on_stack_key((_timer), (_fn), (_flags),	\
+					#_timer, &__key);		 \
 	} while (0)
 #else
-#define __init_timer(_timer, _flags)					\
-	init_timer_key((_timer), (_flags), NULL, NULL)
-#define __init_timer_on_stack(_timer, _flags)				\
-	init_timer_on_stack_key((_timer), (_flags), NULL, NULL)
+#define __init_timer(_timer, _fn, _flags)				\
+	init_timer_key((_timer), (_fn), (_flags), NULL, NULL)
+#define __init_timer_on_stack(_timer, _fn, _flags)			\
+	init_timer_on_stack_key((_timer), (_fn), (_flags), NULL, NULL)
 #endif
 
 #define __setup_timer(_timer, _fn, _flags)				\
 	do {								\
-		__init_timer((_timer), (_flags));			\
-		(_timer)->function = (_fn);				\
+		__init_timer((_timer), (_fn), (_flags));		\
 	} while (0)
 
 #define __setup_timer_on_stack(_timer, _fn, _flags)			\
 	do {								\
-		__init_timer_on_stack((_timer), (_flags));		\
-		(_timer)->function = (_fn);				\
+		__init_timer_on_stack((_timer), (_fn), (_flags));	\
 	} while (0)
 
 #ifndef CONFIG_LOCKDEP

kernel/time/timer.c

@@ -707,14 +707,18 @@ static inline void debug_timer_assert_init(struct timer_list *timer)
 	debug_object_assert_init(timer, &timer_debug_descr);
 }
 
-static void do_init_timer(struct timer_list *timer, unsigned int flags,
+static void do_init_timer(struct timer_list *timer,
+			  void (*func)(struct timer_list *),
+			  unsigned int flags,
 			  const char *name, struct lock_class_key *key);
 
-void init_timer_on_stack_key(struct timer_list *timer, unsigned int flags,
+void init_timer_on_stack_key(struct timer_list *timer,
+			     void (*func)(struct timer_list *),
+			     unsigned int flags,
 			     const char *name, struct lock_class_key *key)
 {
 	debug_object_init_on_stack(timer, &timer_debug_descr);
-	do_init_timer(timer, flags, name, key);
+	do_init_timer(timer, func, flags, name, key);
 }
 EXPORT_SYMBOL_GPL(init_timer_on_stack_key);
 
@@ -755,10 +759,13 @@ static inline void debug_assert_init(struct timer_list *timer)
 	debug_timer_assert_init(timer);
 }
 
-static void do_init_timer(struct timer_list *timer, unsigned int flags,
+static void do_init_timer(struct timer_list *timer,
+			  void (*func)(struct timer_list *),
+			  unsigned int flags,
 			  const char *name, struct lock_class_key *key)
 {
 	timer->entry.pprev = NULL;
+	timer->function = func;
 	timer->flags = flags | raw_smp_processor_id();
 	lockdep_init_map(&timer->lockdep_map, name, key, 0);
 }
@@ -766,6 +773,7 @@ static void do_init_timer(struct timer_list *timer, unsigned int flags,
 /**
  * init_timer_key - initialize a timer
  * @timer: the timer to be initialized
+ * @func: timer callback function
  * @flags: timer flags
  * @name: name of the timer
  * @key: lockdep class key of the fake lock used for tracking timer
@@ -774,11 +782,12 @@ static void do_init_timer(struct timer_list *timer, unsigned int flags,
  * init_timer_key() must be done to a timer prior calling *any* of the
  * other timer functions.
  */
-void init_timer_key(struct timer_list *timer, unsigned int flags,
+void init_timer_key(struct timer_list *timer,
+		    void (*func)(struct timer_list *), unsigned int flags,
 		    const char *name, struct lock_class_key *key)
 {
 	debug_init(timer);
-	do_init_timer(timer, flags, name, key);
+	do_init_timer(timer, func, flags, name, key);
 }
 EXPORT_SYMBOL(init_timer_key);