From: Nam Cao Date: Wed, 5 Feb 2025 10:55:16 +0000 (+0100) Subject: hrtimers: Make callback function pointer private X-Git-Tag: v6.15-rc1~7^2~5 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=04257da0c99c9d4ff7c5bb93046482e1f7d34938;p=thirdparty%2Flinux.git 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: Nam Cao Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/all/7d0e6e0c5c59a64a9bea940051aac05d750bc0c2.1738746927.git.namcao@linutronix.de --- diff --git a/include/linux/hrtimer_types.h b/include/linux/hrtimer_types.h index 7c5b27daa89d0..8fbbb6bdf7a18 100644 --- a/include/linux/hrtimer_types.h +++ b/include/linux/hrtimer_types.h @@ -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; diff --git a/include/trace/events/timer.h b/include/trace/events/timer.h index 1ef58a04fc579..f8c906be4cd0d 100644 --- a/include/trace/events/timer.h +++ b/include/trace/events/timer.h @@ -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", diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 163cde35f0c36..88ea4bbea9c1e 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -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 diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c index cfbb46cc4e761..b03d0ada64695 100644 --- a/kernel/time/timer_list.c +++ b/kernel/time/timer_list.c @@ -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",