Commit 34833819 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'timers-urgent-2025-04-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull misc timer fixes from Ingo Molnar:

 - Fix missing ACCESS_PRIVATE() that triggered a Sparse warning

 - Fix lockdep false positive in tick_freeze() on CONFIG_PREEMPT_RT=y

 - Avoid <vdso/unaligned.h> macro's variable shadowing to address build
   warning that triggers under W=2 builds

* tag 'timers-urgent-2025-04-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  vdso: Address variable shadowing in macros
  timekeeping: Add a lockdep override in tick_freeze()
  hrtimer: Add missing ACCESS_PRIVATE() for hrtimer::function
parents 3c9de67d acea9943

include/linux/hrtimer.h

+1 −1
Original line number Diff line number Diff line
@@ -345,7 +345,7 @@ static inline void hrtimer_update_function(struct hrtimer *timer, 
	if (WARN_ON_ONCE(!function))

		return;

#endif

	timer->function = function;

	ACCESS_PRIVATE(timer, function) = function;

}



/* Forward a hrtimer so it expires after now: */

include/vdso/unaligned.h

+6 −6
Original line number Diff line number Diff line
@@ -3,13 +3,13 @@ 
#define __VDSO_UNALIGNED_H



#define __get_unaligned_t(type, ptr) ({							\

	const struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr);	\

	__pptr->x;								\

	const struct { type x; } __packed * __get_pptr = (typeof(__get_pptr))(ptr);	\

	__get_pptr->x;									\

})



#define __put_unaligned_t(type, val, ptr) do {						\

	struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr);		\

	__pptr->x = (val);							\

	struct { type x; } __packed * __put_pptr = (typeof(__put_pptr))(ptr);		\

	__put_pptr->x = (val);								\

} while (0)



#endif /* __VDSO_UNALIGNED_H */

kernel/time/hrtimer.c

+1 −1
Original line number Diff line number Diff line
@@ -366,7 +366,7 @@ static const struct debug_obj_descr hrtimer_debug_descr; 


static void *hrtimer_debug_hint(void *addr)

{

	return ((struct hrtimer *) addr)->function;

	return ACCESS_PRIVATE((struct hrtimer *)addr, function);

}



/*

kernel/time/tick-common.c

+22 −0
Original line number Diff line number Diff line
@@ -509,6 +509,7 @@ void tick_resume(void) 


#ifdef CONFIG_SUSPEND

static DEFINE_RAW_SPINLOCK(tick_freeze_lock);

static DEFINE_WAIT_OVERRIDE_MAP(tick_freeze_map, LD_WAIT_SLEEP);

static unsigned int tick_freeze_depth;



/**
@@ -528,9 +529,22 @@ void tick_freeze(void) 
	if (tick_freeze_depth == num_online_cpus()) {

		trace_suspend_resume(TPS("timekeeping_freeze"),

				     smp_processor_id(), true);

		/*

		 * All other CPUs have their interrupts disabled and are

		 * suspended to idle. Other tasks have been frozen so there

		 * is no scheduling happening. This means that there is no

		 * concurrency in the system at this point. Therefore it is

		 * okay to acquire a sleeping lock on PREEMPT_RT, such as a

		 * spinlock, because the lock cannot be held by other CPUs

		 * or threads and acquiring it cannot block.

		 *

		 * Inform lockdep about the situation.

		 */

		lock_map_acquire_try(&tick_freeze_map);

		system_state = SYSTEM_SUSPEND;

		sched_clock_suspend();

		timekeeping_suspend();

		lock_map_release(&tick_freeze_map);

	} else {

		tick_suspend_local();

	}
@@ -552,8 +566,16 @@ void tick_unfreeze(void) 
	raw_spin_lock(&tick_freeze_lock);



	if (tick_freeze_depth == num_online_cpus()) {

		/*

		 * Similar to tick_freeze(). On resumption the first CPU may

		 * acquire uncontended sleeping locks while other CPUs block on

		 * tick_freeze_lock.

		 */

		lock_map_acquire_try(&tick_freeze_map);

		timekeeping_resume();

		sched_clock_resume();

		lock_map_release(&tick_freeze_map);



		system_state = SYSTEM_RUNNING;

		trace_suspend_resume(TPS("timekeeping_freeze"),

				     smp_processor_id(), false);