From fbf920f255315974808ce91d934fe50198294d51 Mon Sep 17 00:00:00 2001 From: Nam Cao Date: Thu, 31 Oct 2024 16:14:15 +0100 Subject: hrtimers: Add missing hrtimer_init() trace points hrtimer_init*_on_stack() is not covered by tracing when CONFIG_DEBUG_OBJECTS_TIMERS=y. Rework the functions similar to hrtimer_init() and hrtimer_init_sleeper() so that the hrtimer_init() tracepoint is unconditionally available. The rework makes hrtimer_init_sleeper() unused. Delete it. Signed-off-by: Nam Cao Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/74528e8abf2bb96e8bee85ffacbf14e15cf89f0d.1730386209.git.namcao@linutronix.de --- include/linux/hrtimer.h | 19 +------------------ 1 file changed, 1 insertion(+), 18 deletions(-) (limited to 'include/linux/hrtimer.h') diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index aa1e65ccb615..5aa9d57528c4 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -228,32 +228,15 @@ static inline void hrtimer_cancel_wait_running(struct hrtimer *timer) /* Initialize timers: */ extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock, enum hrtimer_mode mode); -extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, clockid_t clock_id, - enum hrtimer_mode mode); - -#ifdef CONFIG_DEBUG_OBJECTS_TIMERS extern void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t which_clock, enum hrtimer_mode mode); extern void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl, clockid_t clock_id, enum hrtimer_mode mode); +#ifdef CONFIG_DEBUG_OBJECTS_TIMERS extern void destroy_hrtimer_on_stack(struct hrtimer *timer); #else -static inline void hrtimer_init_on_stack(struct hrtimer *timer, - clockid_t which_clock, - enum hrtimer_mode mode) -{ - hrtimer_init(timer, which_clock, mode); -} - -static inline void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl, - clockid_t clock_id, - enum hrtimer_mode mode) -{ - hrtimer_init_sleeper(sl, clock_id, mode); -} - static inline void destroy_hrtimer_on_stack(struct hrtimer *timer) { } #endif -- cgit v1.2.3 From 908a1d775422ba2e27a5e33d0c130b522419e121 Mon Sep 17 00:00:00 2001 From: Nam Cao Date: Thu, 31 Oct 2024 16:14:20 +0100 Subject: hrtimers: Introduce hrtimer_setup() to replace hrtimer_init() To initialize hrtimer, hrtimer_init() needs to be called and also hrtimer::function must be set. This is error-prone and awkward to use. Introduce hrtimer_setup() which does both of these things, so that users of hrtimer can be simplified. The new setup function also has a sanity check for the provided function pointer. If NULL, a warning is emitted and a dummy callback installed. hrtimer_init() will be removed as soon as all of its users have been converted to the new function. Signed-off-by: Nam Cao Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/5057c1ddbfd4b92033cd93d37fe38e6b069d5ba6.1730386209.git.namcao@linutronix.de --- include/linux/hrtimer.h | 2 ++ kernel/time/hrtimer.c | 38 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 40 insertions(+) (limited to 'include/linux/hrtimer.h') diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index 5aa9d57528c4..bcc0715c59a8 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -228,6 +228,8 @@ static inline void hrtimer_cancel_wait_running(struct hrtimer *timer) /* Initialize timers: */ extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock, enum hrtimer_mode mode); +extern void hrtimer_setup(struct hrtimer *timer, enum hrtimer_restart (*function)(struct hrtimer *), + clockid_t clock_id, enum hrtimer_mode mode); extern void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t which_clock, enum hrtimer_mode mode); extern void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl, diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 4b0507cf38ea..a5ef67edcda9 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -1535,6 +1535,11 @@ static inline int hrtimer_clockid_to_base(clockid_t clock_id) return HRTIMER_BASE_MONOTONIC; } +static enum hrtimer_restart hrtimer_dummy_timeout(struct hrtimer *unused) +{ + return HRTIMER_NORESTART; +} + static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id, enum hrtimer_mode mode) { @@ -1571,6 +1576,18 @@ static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id, timerqueue_init(&timer->node); } +static void __hrtimer_setup(struct hrtimer *timer, + enum hrtimer_restart (*function)(struct hrtimer *), + clockid_t clock_id, enum hrtimer_mode mode) +{ + __hrtimer_init(timer, clock_id, mode); + + if (WARN_ON_ONCE(!function)) + timer->function = hrtimer_dummy_timeout; + else + timer->function = function; +} + /** * hrtimer_init - initialize a timer to the given clock * @timer: the timer to be initialized @@ -1591,6 +1608,27 @@ void hrtimer_init(struct hrtimer *timer, clockid_t clock_id, } EXPORT_SYMBOL_GPL(hrtimer_init); +/** + * hrtimer_setup - initialize a timer to the given clock + * @timer: the timer to be initialized + * @function: the callback function + * @clock_id: the clock to be used + * @mode: The modes which are relevant for initialization: + * HRTIMER_MODE_ABS, HRTIMER_MODE_REL, HRTIMER_MODE_ABS_SOFT, + * HRTIMER_MODE_REL_SOFT + * + * The PINNED variants of the above can be handed in, + * but the PINNED bit is ignored as pinning happens + * when the hrtimer is started + */ +void hrtimer_setup(struct hrtimer *timer, enum hrtimer_restart (*function)(struct hrtimer *), + clockid_t clock_id, enum hrtimer_mode mode) +{ + debug_init(timer, clock_id, mode); + __hrtimer_setup(timer, function, clock_id, mode); +} +EXPORT_SYMBOL_GPL(hrtimer_setup); + /** * hrtimer_init_on_stack - initialize a timer in stack memory * @timer: The timer to be initialized -- cgit v1.2.3 From 444cb7db4c9f9b5d96be17c38b3e989df7bfabd5 Mon Sep 17 00:00:00 2001 From: Nam Cao Date: Thu, 31 Oct 2024 16:14:21 +0100 Subject: hrtimers: Introduce hrtimer_setup_on_stack() To initialize hrtimer on stack, hrtimer_init_on_stack() needs to be called and also hrtimer::function must be set. This is error-prone and awkward to use. Introduce hrtimer_setup_on_stack() which does both of these things, so that users of hrtimer can be simplified. The new setup function also has a sanity check for the provided function pointer. If NULL, a warning is emitted and a dummy callback installed. hrtimer_init_on_stack() will be removed as soon as all of its users have been converted to the new function. Signed-off-by: Nam Cao Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/4b05e2ab3a82c517adf67fabc0f0cd8fe118b97c.1730386209.git.namcao@linutronix.de --- include/linux/hrtimer.h | 3 +++ kernel/time/hrtimer.c | 19 +++++++++++++++++++ 2 files changed, 22 insertions(+) (limited to 'include/linux/hrtimer.h') diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index bcc0715c59a8..2da513f8d66a 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -232,6 +232,9 @@ extern void hrtimer_setup(struct hrtimer *timer, enum hrtimer_restart (*function clockid_t clock_id, enum hrtimer_mode mode); extern void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t which_clock, enum hrtimer_mode mode); +extern void hrtimer_setup_on_stack(struct hrtimer *timer, + enum hrtimer_restart (*function)(struct hrtimer *), + clockid_t clock_id, enum hrtimer_mode mode); extern void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl, clockid_t clock_id, enum hrtimer_mode mode); diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index a5ef67edcda9..daee4e27f839 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -1646,6 +1646,25 @@ void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t clock_id, } EXPORT_SYMBOL_GPL(hrtimer_init_on_stack); +/** + * hrtimer_setup_on_stack - initialize a timer on stack memory + * @timer: The timer to be initialized + * @function: the callback function + * @clock_id: The clock to be used + * @mode: The timer mode + * + * Similar to hrtimer_setup(), except that this one must be used if struct hrtimer is in stack + * memory. + */ +void hrtimer_setup_on_stack(struct hrtimer *timer, + enum hrtimer_restart (*function)(struct hrtimer *), + clockid_t clock_id, enum hrtimer_mode mode) +{ + debug_init_on_stack(timer, clock_id, mode); + __hrtimer_setup(timer, function, clock_id, mode); +} +EXPORT_SYMBOL_GPL(hrtimer_setup_on_stack); + /* * A timer is active, when it is enqueued into the rbtree or the * callback function is running or it's in the state of being migrated -- cgit v1.2.3 From c9bd83abfeb9a9b103e689b251ccff7a01be8366 Mon Sep 17 00:00:00 2001 From: Nam Cao Date: Thu, 31 Oct 2024 16:14:22 +0100 Subject: hrtimers: Introduce hrtimer_setup_sleeper_on_stack() The hrtimer_init*() API is replaced by hrtimer_setup*() variants to initialize the timer including the callback function at once. hrtimer_init_sleeper_on_stack() does not need user to setup the callback function separately, so a new variant would not be strictly necessary. Nonetheless, to keep the naming convention consistent, introduce hrtimer_setup_sleeper_on_stack(). hrtimer_init_on_stack() will be removed once all users are converted. Signed-off-by: Nam Cao Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/7b5e18e6dd0ace9eaa211201528cb9dc23752454.1730386209.git.namcao@linutronix.de --- include/linux/hrtimer.h | 2 ++ kernel/time/hrtimer.c | 14 ++++++++++++++ 2 files changed, 16 insertions(+) (limited to 'include/linux/hrtimer.h') diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index 2da513f8d66a..48872a2b4071 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -238,6 +238,8 @@ extern void hrtimer_setup_on_stack(struct hrtimer *timer, extern void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl, clockid_t clock_id, enum hrtimer_mode mode); +extern void hrtimer_setup_sleeper_on_stack(struct hrtimer_sleeper *sl, clockid_t clock_id, + enum hrtimer_mode mode); #ifdef CONFIG_DEBUG_OBJECTS_TIMERS extern void destroy_hrtimer_on_stack(struct hrtimer *timer); diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index daee4e27f839..1d1f5c03673c 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -2065,6 +2065,20 @@ void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl, } EXPORT_SYMBOL_GPL(hrtimer_init_sleeper_on_stack); +/** + * hrtimer_setup_sleeper_on_stack - initialize a sleeper in stack memory + * @sl: sleeper to be initialized + * @clock_id: the clock to be used + * @mode: timer mode abs/rel + */ +void hrtimer_setup_sleeper_on_stack(struct hrtimer_sleeper *sl, + clockid_t clock_id, enum hrtimer_mode mode) +{ + debug_init_on_stack(&sl->timer, clock_id, mode); + __hrtimer_init_sleeper(sl, clock_id, mode); +} +EXPORT_SYMBOL_GPL(hrtimer_setup_sleeper_on_stack); + int nanosleep_copyout(struct restart_block *restart, struct timespec64 *ts) { switch(restart->nanosleep.type) { -- cgit v1.2.3 From 8f02e3563bb5824eb01c94f2c75f1dcee2d05625 Mon Sep 17 00:00:00 2001 From: Nam Cao Date: Thu, 31 Oct 2024 16:14:23 +0100 Subject: hrtimers: Introduce hrtimer_update_function() Some users of hrtimer need to change the callback function after the initial setup. They write to hrtimer::function directly. That's not safe under all circumstances as the write is lockless and a concurrent timer expiry might end up using the wrong function pointer. Introduce hrtimer_update_function(), which also performs runtime checks whether it is safe to modify the callback. This allows to make hrtimer::function private once all users are converted. Signed-off-by: Nam Cao Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/20a937b0ae09ad54b5b6d86eabead7c570f1b72e.1730386209.git.namcao@linutronix.de --- include/linux/hrtimer.h | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'include/linux/hrtimer.h') diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index 48872a2b4071..6e026730e803 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -327,6 +327,28 @@ static inline int hrtimer_callback_running(struct hrtimer *timer) return timer->base->running == timer; } +/** + * hrtimer_update_function - Update the timer's callback function + * @timer: Timer to update + * @function: New callback function + * + * Only safe to call if the timer is not enqueued. Can be called in the callback function if the + * timer is not enqueued at the same time (see the comments above HRTIMER_STATE_ENQUEUED). + */ +static inline void hrtimer_update_function(struct hrtimer *timer, + enum hrtimer_restart (*function)(struct hrtimer *)) +{ + guard(raw_spinlock_irqsave)(&timer->base->cpu_base->lock); + + if (WARN_ON_ONCE(hrtimer_is_queued(timer))) + return; + + if (WARN_ON_ONCE(!function)) + return; + + timer->function = function; +} + /* Forward a hrtimer so it expires after now: */ extern u64 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval); -- cgit v1.2.3 From f3bef7aaa6c807b78e8fc6929c3226d3038fe505 Mon Sep 17 00:00:00 2001 From: Nam Cao Date: Thu, 31 Oct 2024 16:14:29 +0100 Subject: hrtimers: Delete hrtimer_init_sleeper_on_stack() hrtimer_init_sleeper_on_stack() is now unused. Delete it. Signed-off-by: Nam Cao Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/52549846635c0b3a2abf82101f539efdabcd9778.1730386209.git.namcao@linutronix.de --- include/linux/hrtimer.h | 3 --- kernel/time/hrtimer.c | 14 -------------- 2 files changed, 17 deletions(-) (limited to 'include/linux/hrtimer.h') diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index 6e026730e803..4e4f04b3c0c2 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -235,9 +235,6 @@ extern void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t which_clock, extern void hrtimer_setup_on_stack(struct hrtimer *timer, enum hrtimer_restart (*function)(struct hrtimer *), clockid_t clock_id, enum hrtimer_mode mode); -extern void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl, - clockid_t clock_id, - enum hrtimer_mode mode); extern void hrtimer_setup_sleeper_on_stack(struct hrtimer_sleeper *sl, clockid_t clock_id, enum hrtimer_mode mode); diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 69430467a17d..376b8182b72e 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -2051,20 +2051,6 @@ static void __hrtimer_init_sleeper(struct hrtimer_sleeper *sl, sl->task = current; } -/** - * hrtimer_init_sleeper_on_stack - initialize a sleeper in stack memory - * @sl: sleeper to be initialized - * @clock_id: the clock to be used - * @mode: timer mode abs/rel - */ -void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl, - clockid_t clock_id, enum hrtimer_mode mode) -{ - debug_init_on_stack(&sl->timer, clock_id, mode); - __hrtimer_init_sleeper(sl, clock_id, mode); -} -EXPORT_SYMBOL_GPL(hrtimer_init_sleeper_on_stack); - /** * hrtimer_setup_sleeper_on_stack - initialize a sleeper in stack memory * @sl: sleeper to be initialized -- cgit v1.2.3 From 3c2fb0152175f9f596b40763cdc1378297da60af Mon Sep 17 00:00:00 2001 From: Nam Cao Date: Thu, 31 Oct 2024 16:14:33 +0100 Subject: hrtimers: Delete hrtimer_init_on_stack() hrtimer_init_on_stack() is now unused. Delete it. Signed-off-by: Nam Cao Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/510ce0d2944c4a382ea51e51d03dcfb73ba0f4f7.1730386209.git.namcao@linutronix.de --- include/linux/hrtimer.h | 2 -- kernel/time/hrtimer.c | 17 ----------------- 2 files changed, 19 deletions(-) (limited to 'include/linux/hrtimer.h') diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index 4e4f04b3c0c2..7ef5f7ef31a9 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -230,8 +230,6 @@ extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock, enum hrtimer_mode mode); extern void hrtimer_setup(struct hrtimer *timer, enum hrtimer_restart (*function)(struct hrtimer *), clockid_t clock_id, enum hrtimer_mode mode); -extern void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t which_clock, - enum hrtimer_mode mode); extern void hrtimer_setup_on_stack(struct hrtimer *timer, enum hrtimer_restart (*function)(struct hrtimer *), clockid_t clock_id, enum hrtimer_mode mode); diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 376b8182b72e..55e9ffbcd49a 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -1629,23 +1629,6 @@ void hrtimer_setup(struct hrtimer *timer, enum hrtimer_restart (*function)(struc } EXPORT_SYMBOL_GPL(hrtimer_setup); -/** - * hrtimer_init_on_stack - initialize a timer in stack memory - * @timer: The timer to be initialized - * @clock_id: The clock to be used - * @mode: The timer mode - * - * Similar to hrtimer_init(), except that this one must be used if struct hrtimer is in stack - * memory. - */ -void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t clock_id, - enum hrtimer_mode mode) -{ - debug_init_on_stack(timer, clock_id, mode); - __hrtimer_init(timer, clock_id, mode); -} -EXPORT_SYMBOL_GPL(hrtimer_init_on_stack); - /** * hrtimer_setup_on_stack - initialize a timer on stack memory * @timer: The timer to be initialized -- cgit v1.2.3