From d2736470196f2432ca05755fc65136b57a2a6343 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sat, 29 Nov 2025 01:05:30 +0900 Subject: timers: Get rid of del_singleshot_timer_sync() [ Upstream commit 9a5a305686971f4be10c6d7251c8348d74b3e014 ] del_singleshot_timer_sync() used to be an optimization for deleting timers which are not rearmed from the timer callback function. This optimization turned out to be broken and got mapped to del_timer_sync() about 17 years ago. Get rid of the undocumented indirection and use del_timer_sync() directly. No functional change. Signed-off-by: Thomas Gleixner Tested-by: Guenter Roeck Reviewed-by: Jacob Keller Reviewed-by: Anna-Maria Behnsen Link: https://lore.kernel.org/r/20221123201624.706987932@linutronix.de Signed-off-by: Jeongjun Park Signed-off-by: Greg Kroah-Hartman --- include/linux/timer.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include/linux/timer.h') diff --git a/include/linux/timer.h b/include/linux/timer.h index e78521bce565..3c166b4f704d 100644 --- a/include/linux/timer.h +++ b/include/linux/timer.h @@ -198,8 +198,6 @@ static inline int del_timer_sync(struct timer_list *timer) return timer_delete_sync(timer); } -#define del_singleshot_timer_sync(t) del_timer_sync(t) - extern void init_timers(void); struct hrtimer; extern enum hrtimer_restart it_real_fn(struct hrtimer *); -- cgit v1.2.3 From 29d5751350cdf6790aadbe6bd485616f3f0ba86f Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sat, 29 Nov 2025 01:05:32 +0900 Subject: timers: Rename del_timer() to timer_delete() [ Upstream commit bb663f0f3c396c6d05f6c5eeeea96ced20ff112e ] The timer related functions do not have a strict timer_ prefixed namespace which is really annoying. Rename del_timer() to timer_delete() and provide del_timer() as a wrapper. Document that del_timer() is not for new code. Signed-off-by: Thomas Gleixner Tested-by: Guenter Roeck Reviewed-by: Steven Rostedt (Google) Reviewed-by: Jacob Keller Reviewed-by: Anna-Maria Behnsen Link: https://lore.kernel.org/r/20221123201625.015535022@linutronix.de Signed-off-by: Jeongjun Park Signed-off-by: Greg Kroah-Hartman --- include/linux/timer.h | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) (limited to 'include/linux/timer.h') diff --git a/include/linux/timer.h b/include/linux/timer.h index 3c166b4f704d..4bdfa08a2d15 100644 --- a/include/linux/timer.h +++ b/include/linux/timer.h @@ -169,7 +169,6 @@ static inline int timer_pending(const struct timer_list * timer) } extern void add_timer_on(struct timer_list *timer, int cpu); -extern int del_timer(struct timer_list * timer); extern int mod_timer(struct timer_list *timer, unsigned long expires); extern int mod_timer_pending(struct timer_list *timer, unsigned long expires); extern int timer_reduce(struct timer_list *timer, unsigned long expires); @@ -184,6 +183,7 @@ extern void add_timer(struct timer_list *timer); extern int try_to_del_timer_sync(struct timer_list *timer); extern int timer_delete_sync(struct timer_list *timer); +extern int timer_delete(struct timer_list *timer); /** * del_timer_sync - Delete a pending timer and wait for a running callback @@ -198,6 +198,19 @@ static inline int del_timer_sync(struct timer_list *timer) return timer_delete_sync(timer); } +/** + * del_timer - Delete a pending timer + * @timer: The timer to be deleted + * + * See timer_delete() for detailed explanation. + * + * Do not use in new code. Use timer_delete() instead. + */ +static inline int del_timer(struct timer_list *timer) +{ + return timer_delete(timer); +} + extern void init_timers(void); struct hrtimer; extern enum hrtimer_restart it_real_fn(struct hrtimer *); -- cgit v1.2.3 From 36bdfa51a1ad719e3e5f954295874b1e9d8fc072 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sat, 29 Nov 2025 01:05:37 +0900 Subject: timers: Provide timer_shutdown[_sync]() [ Upstream commit f571faf6e443b6011ccb585d57866177af1f643c ] Tearing down timers which have circular dependencies to other functionality, e.g. workqueues, where the timer can schedule work and work can arm timers, is not trivial. In those cases it is desired to shutdown the timer in a way which prevents rearming of the timer. The mechanism to do so is to set timer->function to NULL and use this as an indicator for the timer arming functions to ignore the (re)arm request. Expose new interfaces for this: timer_shutdown_sync() and timer_shutdown(). timer_shutdown_sync() has the same functionality as timer_delete_sync() plus the NULL-ification of the timer function. timer_shutdown() has the same functionality as timer_delete() plus the NULL-ification of the timer function. In both cases the rearming of the timer is prevented by silently discarding rearm attempts due to timer->function being NULL. Co-developed-by: Steven Rostedt Signed-off-by: Steven Rostedt Signed-off-by: Thomas Gleixner Tested-by: Guenter Roeck Reviewed-by: Jacob Keller Reviewed-by: Anna-Maria Behnsen Link: https://lore.kernel.org/all/20220407161745.7d6754b3@gandalf.local.home Link: https://lore.kernel.org/all/20221110064101.429013735@goodmis.org Link: https://lore.kernel.org/r/20221123201625.314230270@linutronix.de Signed-off-by: Jeongjun Park Signed-off-by: Greg Kroah-Hartman --- include/linux/timer.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/timer.h') diff --git a/include/linux/timer.h b/include/linux/timer.h index 4bdfa08a2d15..00ee960be028 100644 --- a/include/linux/timer.h +++ b/include/linux/timer.h @@ -184,6 +184,8 @@ extern void add_timer(struct timer_list *timer); extern int try_to_del_timer_sync(struct timer_list *timer); extern int timer_delete_sync(struct timer_list *timer); extern int timer_delete(struct timer_list *timer); +extern int timer_shutdown_sync(struct timer_list *timer); +extern int timer_shutdown(struct timer_list *timer); /** * del_timer_sync - Delete a pending timer and wait for a running callback -- cgit v1.2.3