Commit 04257da0 authored by Nam Cao's avatar Nam Cao Committed by Ingo Molnar
Browse files

hrtimers: Make callback function pointer private 



Make the struct hrtimer::function field private, to prevent users from
changing this field in an unsafe way. hrtimer_update_function() should be
used if the callback function needs to be changed.

Signed-off-by: default avatarNam Cao <namcao@linutronix.de>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/all/7d0e6e0c5c59a64a9bea940051aac05d750bc0c2.1738746927.git.namcao@linutronix.de
parent 87d82cff

include/linux/hrtimer_types.h

+1 −1
Original line number Diff line number Diff line
@@ -39,7 +39,7 @@ enum hrtimer_restart { 
struct hrtimer {

	struct timerqueue_node		node;

	ktime_t				_softexpires;

	enum hrtimer_restart		(*function)(struct hrtimer *);

	enum hrtimer_restart		(*__private function)(struct hrtimer *);

	struct hrtimer_clock_base	*base;

	u8				state;

	u8				is_rel;

include/trace/events/timer.h

+2 −2
Original line number Diff line number Diff line
@@ -235,7 +235,7 @@ TRACE_EVENT(hrtimer_start, 


	TP_fast_assign(

		__entry->hrtimer	= hrtimer;

		__entry->function	= hrtimer->function;

		__entry->function	= ACCESS_PRIVATE(hrtimer, function);

		__entry->expires	= hrtimer_get_expires(hrtimer);

		__entry->softexpires	= hrtimer_get_softexpires(hrtimer);

		__entry->mode		= mode;
@@ -271,7 +271,7 @@ TRACE_EVENT(hrtimer_expire_entry, 
	TP_fast_assign(

		__entry->hrtimer	= hrtimer;

		__entry->now		= *now;

		__entry->function	= hrtimer->function;

		__entry->function	= ACCESS_PRIVATE(hrtimer, function);

	),



	TP_printk("hrtimer=%p function=%ps now=%llu",

kernel/time/hrtimer.c

+4 −4
Original line number Diff line number Diff line
@@ -1316,7 +1316,7 @@ void hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, 
	struct hrtimer_clock_base *base;

	unsigned long flags;



	if (WARN_ON_ONCE(!timer->function))

	if (WARN_ON_ONCE(!ACCESS_PRIVATE(timer, function)))

		return;

	/*

	 * Check whether the HRTIMER_MODE_SOFT bit and hrtimer.is_soft
@@ -1629,9 +1629,9 @@ static void __hrtimer_setup(struct hrtimer *timer, 
	timerqueue_init(&timer->node);



	if (WARN_ON_ONCE(!function))

		timer->function = hrtimer_dummy_timeout;

		ACCESS_PRIVATE(timer, function) = hrtimer_dummy_timeout;

	else

		timer->function = function;

		ACCESS_PRIVATE(timer, function) = function;

}



/**
@@ -1743,7 +1743,7 @@ static void __run_hrtimer(struct hrtimer_cpu_base *cpu_base, 
	raw_write_seqcount_barrier(&base->seq);



	__remove_hrtimer(timer, base, HRTIMER_STATE_INACTIVE, 0);

	fn = timer->function;

	fn = ACCESS_PRIVATE(timer, function);



	/*

	 * Clear the 'is relative' flag for the TIME_LOW_RES case. If the

kernel/time/timer_list.c

+1 −1
Original line number Diff line number Diff line
@@ -46,7 +46,7 @@ static void 
print_timer(struct seq_file *m, struct hrtimer *taddr, struct hrtimer *timer,

	    int idx, u64 now)

{

	SEQ_printf(m, " #%d: <%p>, %ps", idx, taddr, timer->function);

	SEQ_printf(m, " #%d: <%p>, %ps", idx, taddr, ACCESS_PRIVATE(timer, function));

	SEQ_printf(m, ", S:%02x", timer->state);

	SEQ_printf(m, "\n");

	SEQ_printf(m, " # expires at %Lu-%Lu nsecs [in %Ld to %Ld nsecs]\n",