Merge tag 'timers-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer updates from Thomas Gleixner:
 "A rather large update for timekeeping and timers:

   - The final step to get rid of auto-rearming posix-timers

     posix-timers are currently auto-rearmed by the kernel when the
     signal of the timer is ignored so that the timer signal can be
     delivered once the corresponding signal is unignored.

     This requires to throttle the timer to prevent a DoS by small
     intervals and keeps the system pointlessly out of low power states
     for no value. This is a long standing non-trivial problem due to
     the lock order of posix-timer lock and the sighand lock along with
     life time issues as the timer and the sigqueue have different life
     time rules.

     Cure this by:

       - Embedding the sigqueue into the timer struct to have the same
         life time rules. Aside of that this also avoids the lookup of
         the timer in the signal delivery and rearm path as it's just a
         always valid container_of() now.

       - Queuing ignored timer signals onto a seperate ignored list.

       - Moving queued timer signals onto the ignored list when the
         signal is switched to SIG_IGN before it could be delivered.

       - Walking the ignored list when SIG_IGN is lifted and requeue the
         signals to the actual signal lists. This allows the signal
         delivery code to rearm the timer.

     This also required to consolidate the signal delivery rules so they
     are consistent across all situations. With that all self test
     scenarios finally succeed.

   - Core infrastructure for VFS multigrain timestamping

     This is required to allow the kernel to use coarse grained time
     stamps by default and switch to fine grained time stamps when inode
     attributes are actively observed via getattr().

     These changes have been provided to the VFS tree as well, so that
     the VFS specific infrastructure could be built on top.

   - Cleanup and consolidation of the sleep() infrastructure

       - Move all sleep and timeout functions into one file

       - Rework udelay() and ndelay() into proper documented inline
         functions and replace the hardcoded magic numbers by proper
         defines.

       - Rework the fsleep() implementation to take the reality of the
         timer wheel granularity on different HZ values into account.
         Right now the boundaries are hard coded time ranges which fail
         to provide the requested accuracy on different HZ settings.

       - Update documentation for all sleep/timeout related functions
         and fix up stale documentation links all over the place

       - Fixup a few usage sites

   - Rework of timekeeping and adjtimex(2) to prepare for multiple PTP
     clocks

     A system can have multiple PTP clocks which are participating in
     seperate and independent PTP clock domains. So far the kernel only
     considers the PTP clock which is based on CLOCK TAI relevant as
     that's the clock which drives the timekeeping adjustments via the
     various user space daemons through adjtimex(2).

     The non TAI based clock domains are accessible via the file
     descriptor based posix clocks, but their usability is very limited.
     They can't be accessed fast as they always go all the way out to
     the hardware and they cannot be utilized in the kernel itself.

     As Time Sensitive Networking (TSN) gains traction it is required to
     provide fast user and kernel space access to these clocks.

     The approach taken is to utilize the timekeeping and adjtimex(2)
     infrastructure to provide this access in a similar way how the
     kernel provides access to clock MONOTONIC, REALTIME etc.

     Instead of creating a duplicated infrastructure this rework
     converts timekeeping and adjtimex(2) into generic functionality
     which operates on pointers to data structures instead of using
     static variables.

     This allows to provide time accessors and adjtimex(2) functionality
     for the independent PTP clocks in a subsequent step.

   - Consolidate hrtimer initialization

     hrtimers are set up by initializing the data structure and then
     seperately setting the callback function for historical reasons.

     That's an extra unnecessary step and makes Rust support less
     straight forward than it should be.

     Provide a new set of hrtimer_setup*() functions and convert the
     core code and a few usage sites of the less frequently used
     interfaces over.

     The bulk of the htimer_init() to hrtimer_setup() conversion is
     already prepared and scheduled for the next merge window.

   - Drivers:

       - Ensure that the global timekeeping clocksource is utilizing the
         cluster 0 timer on MIPS multi-cluster systems.

         Otherwise CPUs on different clusters use their cluster specific
         clocksource which is not guaranteed to be synchronized with
         other clusters.

       - Mostly boring cleanups, fixes, improvements and code movement"

* tag 'timers-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (140 commits)
  posix-timers: Fix spurious warning on double enqueue versus do_exit()
  clocksource/drivers/arm_arch_timer: Use of_property_present() for non-boolean properties
  clocksource/drivers/gpx: Remove redundant casts
  clocksource/drivers/timer-ti-dm: Fix child node refcount handling
  dt-bindings: timer: actions,owl-timer: convert to YAML
  clocksource/drivers/ralink: Add Ralink System Tick Counter driver
  clocksource/drivers/mips-gic-timer: Always use cluster 0 counter as clocksource
  clocksource/drivers/timer-ti-dm: Don't fail probe if int not found
  clocksource/drivers:sp804: Make user selectable
  clocksource/drivers/dw_apb: Remove unused dw_apb_clockevent functions
  hrtimers: Delete hrtimer_init_on_stack()
  alarmtimer: Switch to use hrtimer_setup() and hrtimer_setup_on_stack()
  io_uring: Switch to use hrtimer_setup_on_stack()
  sched/idle: Switch to use hrtimer_setup_on_stack()
  hrtimers: Delete hrtimer_init_sleeper_on_stack()
  wait: Switch to use hrtimer_setup_sleeper_on_stack()
  timers: Switch to use hrtimer_setup_sleeper_on_stack()
  net: pktgen: Switch to use hrtimer_setup_sleeper_on_stack()
  futex: Switch to use hrtimer_setup_sleeper_on_stack()
  fs/aio: Switch to use hrtimer_setup_sleeper_on_stack()
  ...

19 files changed, 1354 insertions, 1437 deletions

diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig
index 8ebb6d5a106b..b0b97a60aaa6 100644
--- a/kernel/time/Kconfig
+++ b/kernel/time/Kconfig
@@ -17,11 +17,6 @@ config ARCH_CLOCKSOURCE_DATA
 config ARCH_CLOCKSOURCE_INIT
 	bool
 
-# Clocksources require validation of the clocksource against the last
-# cycle update - x86/TSC misfeature
-config CLOCKSOURCE_VALIDATE_LAST_CYCLE
-	bool
-
 # Timekeeping vsyscall support
 config GENERIC_TIME_VSYSCALL
 	bool
diff --git a/kernel/time/Makefile b/kernel/time/Makefile
index 4af2a264a160..fe0ae82124fe 100644
--- a/kernel/time/Makefile
+++ b/kernel/time/Makefile
@@ -1,5 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0
-obj-y += time.o timer.o hrtimer.o
+obj-y += time.o timer.o hrtimer.o sleep_timeout.o
 obj-y += timekeeping.o ntp.o clocksource.o jiffies.o timer_list.o
 obj-y += timeconv.o timecounter.o alarmtimer.o
 
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index 8bf888641694..0ddccdff119a 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -197,28 +197,15 @@ static enum hrtimer_restart alarmtimer_fired(struct hrtimer *timer)
 {
 	struct alarm *alarm = container_of(timer, struct alarm, timer);
 	struct alarm_base *base = &alarm_bases[alarm->type];
-	unsigned long flags;
-	int ret = HRTIMER_NORESTART;
-	int restart = ALARMTIMER_NORESTART;
 
-	spin_lock_irqsave(&base->lock, flags);
-	alarmtimer_dequeue(base, alarm);
-	spin_unlock_irqrestore(&base->lock, flags);
+	scoped_guard (spinlock_irqsave, &base->lock)
+		alarmtimer_dequeue(base, alarm);
 
 	if (alarm->function)
-		restart = alarm->function(alarm, base->get_ktime());
-
-	spin_lock_irqsave(&base->lock, flags);
-	if (restart != ALARMTIMER_NORESTART) {
-		hrtimer_set_expires(&alarm->timer, alarm->node.expires);
-		alarmtimer_enqueue(base, alarm);
-		ret = HRTIMER_RESTART;
-	}
-	spin_unlock_irqrestore(&base->lock, flags);
+		alarm->function(alarm, base->get_ktime());
 
 	trace_alarmtimer_fired(alarm, base->get_ktime());
-	return ret;
-
+	return HRTIMER_NORESTART;
 }
 
 ktime_t alarm_expires_remaining(const struct alarm *alarm)
@@ -334,10 +321,9 @@ static int alarmtimer_resume(struct device *dev)
 
 static void
 __alarm_init(struct alarm *alarm, enum alarmtimer_type type,
-	     enum alarmtimer_restart (*function)(struct alarm *, ktime_t))
+	     void (*function)(struct alarm *, ktime_t))
 {
 	timerqueue_init(&alarm->node);
-	alarm->timer.function = alarmtimer_fired;
 	alarm->function = function;
 	alarm->type = type;
 	alarm->state = ALARMTIMER_STATE_INACTIVE;
@@ -350,10 +336,10 @@ __alarm_init(struct alarm *alarm, enum alarmtimer_type type,
  * @function: callback that is run when the alarm fires
  */
 void alarm_init(struct alarm *alarm, enum alarmtimer_type type,
-		enum alarmtimer_restart (*function)(struct alarm *, ktime_t))
+		void (*function)(struct alarm *, ktime_t))
 {
-	hrtimer_init(&alarm->timer, alarm_bases[type].base_clockid,
-		     HRTIMER_MODE_ABS);
+	hrtimer_setup(&alarm->timer, alarmtimer_fired, alarm_bases[type].base_clockid,
+		      HRTIMER_MODE_ABS);
 	__alarm_init(alarm, type, function);
 }
 EXPORT_SYMBOL_GPL(alarm_init);
@@ -480,35 +466,11 @@ u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval)
 }
 EXPORT_SYMBOL_GPL(alarm_forward);
 
-static u64 __alarm_forward_now(struct alarm *alarm, ktime_t interval, bool throttle)
+u64 alarm_forward_now(struct alarm *alarm, ktime_t interval)
 {
 	struct alarm_base *base = &alarm_bases[alarm->type];
-	ktime_t now = base->get_ktime();
-
-	if (IS_ENABLED(CONFIG_HIGH_RES_TIMERS) && throttle) {
-		/*
-		 * Same issue as with posix_timer_fn(). Timers which are
-		 * periodic but the signal is ignored can starve the system
-		 * with a very small interval. The real fix which was
-		 * promised in the context of posix_timer_fn() never
-		 * materialized, but someone should really work on it.
-		 *
-		 * To prevent DOS fake @now to be 1 jiffy out which keeps
-		 * the overrun accounting correct but creates an
-		 * inconsistency vs. timer_gettime(2).
-		 */
-		ktime_t kj = NSEC_PER_SEC / HZ;
 
-		if (interval < kj)
-			now = ktime_add(now, kj);
-	}
-
-	return alarm_forward(alarm, now, interval);
-}
-
-u64 alarm_forward_now(struct alarm *alarm, ktime_t interval)
-{
-	return __alarm_forward_now(alarm, interval, false);
+	return alarm_forward(alarm, base->get_ktime(), interval);
 }
 EXPORT_SYMBOL_GPL(alarm_forward_now);
 
@@ -567,30 +529,12 @@ static enum alarmtimer_type clock2alarm(clockid_t clockid)
  *
  * Return: whether the timer is to be restarted
  */
-static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm,
-							ktime_t now)
+static void alarm_handle_timer(struct alarm *alarm, ktime_t now)
 {
-	struct k_itimer *ptr = container_of(alarm, struct k_itimer,
-					    it.alarm.alarmtimer);
-	enum alarmtimer_restart result = ALARMTIMER_NORESTART;
-	unsigned long flags;
+	struct k_itimer *ptr = container_of(alarm, struct k_itimer, it.alarm.alarmtimer);
 
-	spin_lock_irqsave(&ptr->it_lock, flags);
-
-	if (posix_timer_queue_signal(ptr) && ptr->it_interval) {
-		/*
-		 * Handle ignored signals and rearm the timer. This will go
-		 * away once we handle ignored signals proper. Ensure that
-		 * small intervals cannot starve the system.
-		 */
-		ptr->it_overrun += __alarm_forward_now(alarm, ptr->it_interval, true);
-		++ptr->it_requeue_pending;
-		ptr->it_active = 1;
-		result = ALARMTIMER_RESTART;
-	}
-	spin_unlock_irqrestore(&ptr->it_lock, flags);
-
-	return result;
+	guard(spinlock_irqsave)(&ptr->it_lock);
+	posix_timer_queue_signal(ptr);
 }
 
 /**
@@ -751,18 +695,14 @@ static int alarm_timer_create(struct k_itimer *new_timer)
  * @now: time at the timer expiration
  *
  * Wakes up the task that set the alarmtimer
- *
- * Return: ALARMTIMER_NORESTART
  */
-static enum alarmtimer_restart alarmtimer_nsleep_wakeup(struct alarm *alarm,
-								ktime_t now)
+static void alarmtimer_nsleep_wakeup(struct alarm *alarm, ktime_t now)
 {
 	struct task_struct *task = alarm->data;
 
 	alarm->data = NULL;
 	if (task)
 		wake_up_process(task);
-	return ALARMTIMER_NORESTART;
 }
 
 /**
@@ -814,10 +754,10 @@ static int alarmtimer_do_nsleep(struct alarm *alarm, ktime_t absexp,
 
 static void
 alarm_init_on_stack(struct alarm *alarm, enum alarmtimer_type type,
-		    enum alarmtimer_restart (*function)(struct alarm *, ktime_t))
+		    void (*function)(struct alarm *, ktime_t))
 {
-	hrtimer_init_on_stack(&alarm->timer, alarm_bases[type].base_clockid,
-			      HRTIMER_MODE_ABS);
+	hrtimer_setup_on_stack(&alarm->timer, alarmtimer_fired, alarm_bases[type].base_clockid,
+			       HRTIMER_MODE_ABS);
 	__alarm_init(alarm, type, function);
 }
 
diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index 78c7bd64d0dd..f3e831f62906 100644
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -337,13 +337,21 @@ int clockevents_program_event(struct clock_event_device *dev, ktime_t expires,
 }
 
 /*
- * Called after a notify add to make devices available which were
- * released from the notifier call.
+ * Called after a clockevent has been added which might
+ * have replaced a current regular or broadcast device. A
+ * released normal device might be a suitable replacement
+ * for the current broadcast device. Similarly a released
+ * broadcast device might be a suitable replacement for a
+ * normal device.
  */
 static void clockevents_notify_released(void)
 {
 	struct clock_event_device *dev;
 
+	/*
+	 * Keep iterating as long as tick_check_new_device()
+	 * replaces a device.
+	 */
 	while (!list_empty(&clockevents_released)) {
 		dev = list_entry(clockevents_released.next,
 				 struct clock_event_device, list);
@@ -610,39 +618,30 @@ void clockevents_resume(void)
 
 #ifdef CONFIG_HOTPLUG_CPU
 
-# ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
 /**
- * tick_offline_cpu - Take CPU out of the broadcast mechanism
+ * tick_offline_cpu - Shutdown all clock events related
+ *                    to this CPU and take it out of the
+ *                    broadcast mechanism.
  * @cpu:	The outgoing CPU
  *
- * Called on the outgoing CPU after it took itself offline.
+ * Called by the dying CPU during teardown.
  */
 void tick_offline_cpu(unsigned int cpu)
 {
-	raw_spin_lock(&clockevents_lock);
-	tick_broadcast_offline(cpu);
-	raw_spin_unlock(&clockevents_lock);
-}
-# endif
-
-/**
- * tick_cleanup_dead_cpu - Cleanup the tick and clockevents of a dead cpu
- * @cpu:	The dead CPU
- */
-void tick_cleanup_dead_cpu(int cpu)
-{
 	struct clock_event_device *dev, *tmp;
-	unsigned long flags;
 
-	raw_spin_lock_irqsave(&clockevents_lock, flags);
+	raw_spin_lock(&clockevents_lock);
 
+	tick_broadcast_offline(cpu);
 	tick_shutdown(cpu);
+
 	/*
 	 * Unregister the clock event devices which were
-	 * released from the users in the notify chain.
+	 * released above.
 	 */
 	list_for_each_entry_safe(dev, tmp, &clockevents_released, list)
 		list_del(&dev->list);
+
 	/*
 	 * Now check whether the CPU has left unused per cpu devices
 	 */
@@ -654,7 +653,8 @@ void tick_cleanup_dead_cpu(int cpu)
 			list_del(&dev->list);
 		}
 	}
-	raw_spin_unlock_irqrestore(&clockevents_lock, flags);
+
+	raw_spin_unlock(&clockevents_lock);
 }
 #endif
 
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 23336eecb4f4..aab6472853fa 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -20,6 +20,8 @@
 #include "tick-internal.h"
 #include "timekeeping_internal.h"
 
+static void clocksource_enqueue(struct clocksource *cs);
+
 static noinline u64 cycles_to_nsec_safe(struct clocksource *cs, u64 start, u64 end)
 {
 	u64 delta = clocksource_delta(end, start, cs->mask);
@@ -171,7 +173,6 @@ static inline void clocksource_watchdog_unlock(unsigned long *flags)
 }
 
 static int clocksource_watchdog_kthread(void *data);
-static void __clocksource_change_rating(struct clocksource *cs, int rating);
 
 static void clocksource_watchdog_work(struct work_struct *work)
 {
@@ -191,6 +192,13 @@ static void clocksource_watchdog_work(struct work_struct *work)
 	kthread_run(clocksource_watchdog_kthread, NULL, "kwatchdog");
 }
 
+static void clocksource_change_rating(struct clocksource *cs, int rating)
+{
+	list_del(&cs->list);
+	cs->rating = rating;
+	clocksource_enqueue(cs);
+}
+
 static void __clocksource_unstable(struct clocksource *cs)
 {
 	cs->flags &= ~(CLOCK_SOURCE_VALID_FOR_HRES | CLOCK_SOURCE_WATCHDOG);
@@ -697,7 +705,7 @@ static int __clocksource_watchdog_kthread(void)
 	list_for_each_entry_safe(cs, tmp, &watchdog_list, wd_list) {
 		if (cs->flags & CLOCK_SOURCE_UNSTABLE) {
 			list_del_init(&cs->wd_list);
-			__clocksource_change_rating(cs, 0);
+			clocksource_change_rating(cs, 0);
 			select = 1;
 		}
 		if (cs->flags & CLOCK_SOURCE_RESELECT) {
@@ -1255,34 +1263,6 @@ int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq)
 }
 EXPORT_SYMBOL_GPL(__clocksource_register_scale);
 
-static void __clocksource_change_rating(struct clocksource *cs, int rating)
-{
-	list_del(&cs->list);
-	cs->rating = rating;
-	clocksource_enqueue(cs);
-}
-
-/**
- * clocksource_change_rating - Change the rating of a registered clocksource
- * @cs:		clocksource to be changed
- * @rating:	new rating
- */
-void clocksource_change_rating(struct clocksource *cs, int rating)
-{
-	unsigned long flags;
-
-	mutex_lock(&clocksource_mutex);
-	clocksource_watchdog_lock(&flags);
-	__clocksource_change_rating(cs, rating);
-	clocksource_watchdog_unlock(&flags);
-
-	clocksource_select();
-	clocksource_select_watchdog(false);
-	clocksource_suspend_select(false);
-	mutex_unlock(&clocksource_mutex);
-}
-EXPORT_SYMBOL(clocksource_change_rating);
-
 /*
  * Unbind clocksource @cs. Called with clocksource_mutex held
  */
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index d9911516e743..80fe3749d2db 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -417,6 +417,11 @@ static inline void debug_hrtimer_init(struct hrtimer *timer)
 	debug_object_init(timer, &hrtimer_debug_descr);
 }
 
+static inline void debug_hrtimer_init_on_stack(struct hrtimer *timer)
+{
+	debug_object_init_on_stack(timer, &hrtimer_debug_descr);
+}
+
 static inline void debug_hrtimer_activate(struct hrtimer *timer,
 					  enum hrtimer_mode mode)
 {
@@ -428,28 +433,6 @@ static inline void debug_hrtimer_deactivate(struct hrtimer *timer)
 	debug_object_deactivate(timer, &hrtimer_debug_descr);
 }
 
-static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
-			   enum hrtimer_mode mode);
-
-void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t clock_id,
-			   enum hrtimer_mode mode)
-{
-	debug_object_init_on_stack(timer, &hrtimer_debug_descr);
-	__hrtimer_init(timer, clock_id, mode);
-}
-EXPORT_SYMBOL_GPL(hrtimer_init_on_stack);
-
-static void __hrtimer_init_sleeper(struct hrtimer_sleeper *sl,
-				   clockid_t clock_id, enum hrtimer_mode mode);
-
-void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl,
-				   clockid_t clock_id, enum hrtimer_mode mode)
-{
-	debug_object_init_on_stack(&sl->timer, &hrtimer_debug_descr);
-	__hrtimer_init_sleeper(sl, clock_id, mode);
-}
-EXPORT_SYMBOL_GPL(hrtimer_init_sleeper_on_stack);
-
 void destroy_hrtimer_on_stack(struct hrtimer *timer)
 {
 	debug_object_free(timer, &hrtimer_debug_descr);
@@ -459,6 +442,7 @@ EXPORT_SYMBOL_GPL(destroy_hrtimer_on_stack);
 #else
 
 static inline void debug_hrtimer_init(struct hrtimer *timer) { }
+static inline void debug_hrtimer_init_on_stack(struct hrtimer *timer) { }
 static inline void debug_hrtimer_activate(struct hrtimer *timer,
 					  enum hrtimer_mode mode) { }
 static inline void debug_hrtimer_deactivate(struct hrtimer *timer) { }
@@ -472,6 +456,13 @@ debug_init(struct hrtimer *timer, clockid_t clockid,
 	trace_hrtimer_init(timer, clockid, mode);
 }
 
+static inline void debug_init_on_stack(struct hrtimer *timer, clockid_t clockid,
+				       enum hrtimer_mode mode)
+{
+	debug_hrtimer_init_on_stack(timer);
+	trace_hrtimer_init(timer, clockid, mode);
+}
+
 static inline void debug_activate(struct hrtimer *timer,
 				  enum hrtimer_mode mode)
 {
@@ -1544,6 +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)
 {
@@ -1580,6 +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
@@ -1600,6 +1608,46 @@ 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_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
@@ -1944,7 +1992,7 @@ void hrtimer_sleeper_start_expires(struct hrtimer_sleeper *sl,
 	 * Make the enqueue delivery mode check work on RT. If the sleeper
 	 * was initialized for hard interrupt delivery, force the mode bit.
 	 * This is a special case for hrtimer_sleepers because
-	 * hrtimer_init_sleeper() determines the delivery mode on RT so the
+	 * __hrtimer_init_sleeper() determines the delivery mode on RT so the
 	 * fiddling with this decision is avoided at the call sites.
 	 */
 	if (IS_ENABLED(CONFIG_PREEMPT_RT) && sl->timer.is_hard)
@@ -1987,19 +2035,18 @@ static void __hrtimer_init_sleeper(struct hrtimer_sleeper *sl,
 }
 
 /**
- * hrtimer_init_sleeper - initialize sleeper to the given clock
+ * 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_init_sleeper(struct hrtimer_sleeper *sl, clockid_t clock_id,
-			  enum hrtimer_mode mode)
+void hrtimer_setup_sleeper_on_stack(struct hrtimer_sleeper *sl,
+				    clockid_t clock_id, enum hrtimer_mode mode)
 {
-	debug_init(&sl->timer, clock_id, mode);
+	debug_init_on_stack(&sl->timer, clock_id, mode);
 	__hrtimer_init_sleeper(sl, clock_id, mode);
-
 }
-EXPORT_SYMBOL_GPL(hrtimer_init_sleeper);
+EXPORT_SYMBOL_GPL(hrtimer_setup_sleeper_on_stack);
 
 int nanosleep_copyout(struct restart_block *restart, struct timespec64 *ts)
 {
@@ -2060,8 +2107,7 @@ static long __sched hrtimer_nanosleep_restart(struct restart_block *restart)
 	struct hrtimer_sleeper t;
 	int ret;
 
-	hrtimer_init_sleeper_on_stack(&t, restart->nanosleep.clockid,
-				      HRTIMER_MODE_ABS);
+	hrtimer_setup_sleeper_on_stack(&t, restart->nanosleep.clockid, HRTIMER_MODE_ABS);
 	hrtimer_set_expires_tv64(&t.timer, restart->nanosleep.expires);
 	ret = do_nanosleep(&t, HRTIMER_MODE_ABS);
 	destroy_hrtimer_on_stack(&t.timer);
@@ -2075,7 +2121,7 @@ long hrtimer_nanosleep(ktime_t rqtp, const enum hrtimer_mode mode,
 	struct hrtimer_sleeper t;
 	int ret = 0;
 
-	hrtimer_init_sleeper_on_stack(&t, clockid, mode);
+	hrtimer_setup_sleeper_on_stack(&t, clockid, mode);
 	hrtimer_set_expires_range_ns(&t.timer, rqtp, current->timer_slack_ns);
 	ret = do_nanosleep(&t, mode);
 	if (ret != -ERESTART_RESTARTBLOCK)
@@ -2242,123 +2288,3 @@ void __init hrtimers_init(void)
 	hrtimers_prepare_cpu(smp_processor_id());
 	open_softirq(HRTIMER_SOFTIRQ, hrtimer_run_softirq);
 }
-
-/**
- * schedule_hrtimeout_range_clock - sleep until timeout
- * @expires:	timeout value (ktime_t)
- * @delta:	slack in expires timeout (ktime_t)
- * @mode:	timer mode
- * @clock_id:	timer clock to be used
- */
-int __sched
-schedule_hrtimeout_range_clock(ktime_t *expires, u64 delta,
-			       const enum hrtimer_mode mode, clockid_t clock_id)
-{
-	struct hrtimer_sleeper t;
-
-	/*
-	 * Optimize when a zero timeout value is given. It does not
-	 * matter whether this is an absolute or a relative time.
-	 */
-	if (expires && *expires == 0) {
-		__set_current_state(TASK_RUNNING);
-		return 0;
-	}
-
-	/*
-	 * A NULL parameter means "infinite"
-	 */
-	if (!expires) {
-		schedule();
-		return -EINTR;
-	}
-
-	hrtimer_init_sleeper_on_stack(&t, clock_id, mode);
-	hrtimer_set_expires_range_ns(&t.timer, *expires, delta);
-	hrtimer_sleeper_start_expires(&t, mode);
-
-	if (likely(t.task))
-		schedule();
-
-	hrtimer_cancel(&t.timer);
-	destroy_hrtimer_on_stack(&t.timer);
-
-	__set_current_state(TASK_RUNNING);
-
-	return !t.task ? 0 : -EINTR;
-}
-EXPORT_SYMBOL_GPL(schedule_hrtimeout_range_clock);
-
-/**
- * schedule_hrtimeout_range - sleep until timeout
- * @expires:	timeout value (ktime_t)
- * @delta:	slack in expires timeout (ktime_t)
- * @mode:	timer mode
- *
- * Make the current task sleep until the given expiry time has
- * elapsed. The routine will return immediately unless
- * the current task state has been set (see set_current_state()).
- *
- * The @delta argument gives the kernel the freedom to schedule the
- * actual wakeup to a time that is both power and performance friendly
- * for regular (non RT/DL) tasks.
- * The kernel give the normal best effort behavior for "@expires+@delta",
- * but may decide to fire the timer earlier, but no earlier than @expires.
- *
- * You can set the task state as follows -
- *
- * %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to
- * pass before the routine returns unless the current task is explicitly
- * woken up, (e.g. by wake_up_process()).
- *
- * %TASK_INTERRUPTIBLE - the routine may return early if a signal is
- * delivered to the current task or the current task is explicitly woken
- * up.
- *
- * The current task state is guaranteed to be TASK_RUNNING when this
- * routine returns.
- *
- * Returns 0 when the timer has expired. If the task was woken before the
- * timer expired by a signal (only possible in state TASK_INTERRUPTIBLE) or
- * by an explicit wakeup, it returns -EINTR.
- */
-int __sched schedule_hrtimeout_range(ktime_t *expires, u64 delta,
-				     const enum hrtimer_mode mode)
-{
-	return schedule_hrtimeout_range_clock(expires, delta, mode,
-					      CLOCK_MONOTONIC);
-}
-EXPORT_SYMBOL_GPL(schedule_hrtimeout_range);
-
-/**
- * schedule_hrtimeout - sleep until timeout
- * @expires:	timeout value (ktime_t)
- * @mode:	timer mode
- *
- * Make the current task sleep until the given expiry time has
- * elapsed. The routine will return immediately unless
- * the current task state has been set (see set_current_state()).
- *
- * You can set the task state as follows -
- *
- * %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to
- * pass before the routine returns unless the current task is explicitly
- * woken up, (e.g. by wake_up_process()).
- *
- * %TASK_INTERRUPTIBLE - the routine may return early if a signal is
- * delivered to the current task or the current task is explicitly woken
- * up.
- *
- * The current task state is guaranteed to be TASK_RUNNING when this
- * routine returns.
- *
- * Returns 0 when the timer has expired. If the task was woken before the
- * timer expired by a signal (only possible in state TASK_INTERRUPTIBLE) or
- * by an explicit wakeup, it returns -EINTR.
- */
-int __sched schedule_hrtimeout(ktime_t *expires,
-			       const enum hrtimer_mode mode)
-{
-	return schedule_hrtimeout_range(expires, 0, mode);
-}
-EXPORT_SYMBOL_GPL(schedule_hrtimeout);
diff --git a/kernel/time/itimer.c b/kernel/time/itimer.c
index 00629e658ca1..876d389b2e21 100644
--- a/kernel/time/itimer.c
+++ b/kernel/time/itimer.c
@@ -151,7 +151,27 @@ COMPAT_SYSCALL_DEFINE2(getitimer, int, which,
 #endif
 
 /*
- * The timer is automagically restarted, when interval != 0
+ * Invoked from dequeue_signal() when SIG_ALRM is delivered.
+ *
+ * Restart the ITIMER_REAL timer if it is armed as periodic timer.  Doing
+ * this in the signal delivery path instead of self rearming prevents a DoS
+ * with small increments in the high reolution timer case and reduces timer
+ * noise in general.
+ */
+void posixtimer_rearm_itimer(struct task_struct *tsk)
+{
+	struct hrtimer *tmr = &tsk->signal->real_timer;
+
+	if (!hrtimer_is_queued(tmr) && tsk->signal->it_real_incr != 0) {
+		hrtimer_forward(tmr, tmr->base->get_time(),
+				tsk->signal->it_real_incr);
+		hrtimer_restart(tmr);
+	}
+}
+
+/*
+ * Interval timers are restarted in the signal delivery path.  See
+ * posixtimer_rearm_itimer().
  */
 enum hrtimer_restart it_real_fn(struct hrtimer *timer)
 {
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index 802b336f4b8c..b550ebe0f03b 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -22,22 +22,79 @@
 #include "ntp_internal.h"
 #include "timekeeping_internal.h"
 
-
-/*
- * NTP timekeeping variables:
+/**
+ * struct ntp_data - Structure holding all NTP related state
+ * @tick_usec:		USER_HZ period in microseconds
+ * @tick_length:	Adjusted tick length
+ * @tick_length_base:	Base value for @tick_length
+ * @time_state:		State of the clock synchronization
+ * @time_status:	Clock status bits
+ * @time_offset:	Time adjustment in nanoseconds
+ * @time_constant:	PLL time constant
+ * @time_maxerror:	Maximum error in microseconds holding the NTP sync distance
+ *			(NTP dispersion + delay / 2)
+ * @time_esterror:	Estimated error in microseconds holding NTP dispersion
+ * @time_freq:		Frequency offset scaled nsecs/secs
+ * @time_reftime:	Time at last adjustment in seconds
+ * @time_adjust:	Adjustment value
+ * @ntp_tick_adj:	Constant boot-param configurable NTP tick adjustment (upscaled)
+ * @ntp_next_leap_sec:	Second value of the next pending leapsecond, or TIME64_MAX if no leap
  *
- * Note: All of the NTP state is protected by the timekeeping locks.
+ * @pps_valid:		PPS signal watchdog counter
+ * @pps_tf:		PPS phase median filter
+ * @pps_jitter:		PPS current jitter in nanoseconds
+ * @pps_fbase:		PPS beginning of the last freq interval
+ * @pps_shift:		PPS current interval duration in seconds (shift value)
+ * @pps_intcnt:		PPS interval counter
+ * @pps_freq:		PPS frequency offset in scaled ns/s
+ * @pps_stabil:		PPS current stability in scaled ns/s
+ * @pps_calcnt:		PPS monitor: calibration intervals
+ * @pps_jitcnt:		PPS monitor: jitter limit exceeded
+ * @pps_stbcnt:		PPS monitor: stability limit exceeded
+ * @pps_errcnt:		PPS monitor: calibration errors
+ *
+ * Protected by the timekeeping locks.
  */
+struct ntp_data {
+	unsigned long		tick_usec;
+	u64			tick_length;
+	u64			tick_length_base;
+	int			time_state;
+	int			time_status;
+	s64			time_offset;
+	long			time_constant;
+	long			time_maxerror;
+	long			time_esterror;
+	s64			time_freq;
+	time64_t		time_reftime;
+	long			time_adjust;
+	s64			ntp_tick_adj;
+	time64_t		ntp_next_leap_sec;
+#ifdef CONFIG_NTP_PPS
+	int			pps_valid;
+	long			pps_tf[3];
+	long			pps_jitter;
+	struct timespec64	pps_fbase;
+	int			pps_shift;
+	int			pps_intcnt;
+	s64			pps_freq;
+	long			pps_stabil;
+	long			pps_calcnt;
+	long			pps_jitcnt;
+	long			pps_stbcnt;
+	long			pps_errcnt;
+#endif
+};
 
-
-/* USER_HZ period (usecs): */
-unsigned long			tick_usec = USER_TICK_USEC;
-
-/* SHIFTED_HZ period (nsecs): */
-unsigned long			tick_nsec;
-
-static u64			tick_length;
-static u64			tick_length_base;
+static struct ntp_data tk_ntp_data = {
+	.tick_usec		= USER_TICK_USEC,
+	.time_state		= TIME_OK,
+	.time_status		= STA_UNSYNC,
+	.time_constant		= 2,
+	.time_maxerror		= NTP_PHASE_LIMIT,
+	.time_esterror		= NTP_PHASE_LIMIT,
+	.ntp_next_leap_sec	= TIME64_MAX,
+};
 
 #define SECS_PER_DAY		86400
 #define MAX_TICKADJ		500LL		/* usecs */
@@ -45,46 +102,6 @@ static u64			tick_length_base;
 	(((MAX_TICKADJ * NSEC_PER_USEC) << NTP_SCALE_SHIFT) / NTP_INTERVAL_FREQ)
 #define MAX_TAI_OFFSET		100000
 
-/*
- * phase-lock loop variables
- */
-
-/*
- * clock synchronization status
- *
- * (TIME_ERROR prevents overwriting the CMOS clock)
- */
-static int			time_state = TIME_OK;
-
-/* clock status bits:							*/
-static int			time_status = STA_UNSYNC;
-
-/* time adjustment (nsecs):						*/
-static s64			time_offset;
-
-/* pll time constant:							*/
-static long			time_constant = 2;
-
-/* maximum error (usecs):						*/
-static long			time_maxerror = NTP_PHASE_LIMIT;
-
-/* estimated error (usecs):						*/
-static long			time_esterror = NTP_PHASE_LIMIT;
-
-/* frequency offset (scaled nsecs/secs):				*/
-static s64			time_freq;
-
-/* time at last adjustment (secs):					*/
-static time64_t		time_reftime;
-
-static long			time_adjust;
-
-/* constant (boot-param configurable) NTP tick adjustment (upscaled)	*/
-static s64			ntp_tick_adj;
-
-/* second value of the next pending leapsecond, or TIME64_MAX if no leap */
-static time64_t			ntp_next_leap_sec = TIME64_MAX;
-
 #ifdef CONFIG_NTP_PPS
 
 /*
@@ -101,128 +118,115 @@ static time64_t			ntp_next_leap_sec = TIME64_MAX;
 				   intervals to decrease it */
 #define PPS_MAXWANDER	100000	/* max PPS freq wander (ns/s) */
 
-static int pps_valid;		/* signal watchdog counter */
-static long pps_tf[3];		/* phase median filter */
-static long pps_jitter;		/* current jitter (ns) */
-static struct timespec64 pps_fbase; /* beginning of the last freq interval */
-static int pps_shift;		/* current interval duration (s) (shift) */
-static int pps_intcnt;		/* interval counter */
-static s64 pps_freq;		/* frequency offset (scaled ns/s) */
-static long pps_stabil;		/* current stability (scaled ns/s) */
-
 /*
- * PPS signal quality monitors
- */
-static long pps_calcnt;		/* calibration intervals */
-static long pps_jitcnt;		/* jitter limit exceeded */
-static long pps_stbcnt;		/* stability limit exceeded */
-static long pps_errcnt;		/* calibration errors */
-
-
-/* PPS kernel consumer compensates the whole phase error immediately.
+ * PPS kernel consumer compensates the whole phase error immediately.
  * Otherwise, reduce the offset by a fixed factor times the time constant.
  */
-static inline s64 ntp_offset_chunk(s64 offset)
+static inline s64 ntp_offset_chunk(struct ntp_data *ntpdata, s64 offset)
 {
-	if (time_status & STA_PPSTIME && time_status & STA_PPSSIGNAL)
+	if (ntpdata->time_status & STA_PPSTIME && ntpdata->time_status & STA_PPSSIGNAL)
 		return offset;
 	else
-		return shift_right(offset, SHIFT_PLL + time_constant);
+		return shift_right(offset, SHIFT_PLL + ntpdata->time_constant);
 }
 
-static inline void pps_reset_freq_interval(void)
+static inline void pps_reset_freq_interval(struct ntp_data *ntpdata)
 {
-	/* the PPS calibration interval may end
-	   surprisingly early */
-	pps_shift = PPS_INTMIN;
-	pps_intcnt = 0;
+	/* The PPS calibration interval may end surprisingly early */
+	ntpdata->pps_shift = PPS_INTMIN;
+	ntpdata->pps_intcnt = 0;
 }
 
 /**
  * pps_clear - Clears the PPS state variables
+ * @ntpdata:	Pointer to ntp data
  */
-static inline void pps_clear(void)
+static inline void pps_clear(struct ntp_data *ntpdata)
 {
-	pps_reset_freq_interval();
-	pps_tf[0] = 0;
-	pps_tf[1] = 0;
-	pps_tf[2] = 0;
-	pps_fbase.tv_sec = pps_fbase.tv_nsec = 0;
-	pps_freq = 0;
+	pps_reset_freq_interval(ntpdata);
+	ntpdata->pps_tf[0] = 0;
+	ntpdata->pps_tf[1] = 0;
+	ntpdata->pps_tf[2] = 0;
+	ntpdata->pps_fbase.tv_sec = ntpdata->pps_fbase.tv_nsec = 0;
+	ntpdata->pps_freq = 0;
 }
 
-/* Decrease pps_valid to indicate that another second has passed since
- * the last PPS signal. When it reaches 0, indicate that PPS signal is
- * missing.
+/*
+ * Decrease pps_valid to indicate that another second has passed since the
+ * last PPS signal. When it reaches 0, indicate that PPS signal is missing.
  */
-static inline void pps_dec_valid(void)
+static inline void pps_dec_valid(struct ntp_data *ntpdata)
 {
-	if (pps_valid > 0)
-		pps_valid--;
-	else {
-		time_status &= ~(STA_PPSSIGNAL | STA_PPSJITTER |
-				 STA_PPSWANDER | STA_PPSERROR);
-		pps_clear();
+	if (ntpdata->pps_valid > 0) {
+		ntpdata->pps_valid--;
+	} else {
+		ntpdata->time_status &= ~(STA_PPSSIGNAL | STA_PPSJITTER |
+					  STA_PPSWANDER | STA_PPSERROR);
+		pps_clear(ntpdata);
 	}
 }
 
-static inline void pps_set_freq(s64 freq)
+static inline void pps_set_freq(struct ntp_data *ntpdata)
 {
-	pps_freq = freq;
+	ntpdata->pps_freq = ntpdata->time_freq;
 }
 
-static inline int is_error_status(int status)
+static inline bool is_error_status(int status)
 {
 	return (status & (STA_UNSYNC|STA_CLOCKERR))
-		/* PPS signal lost when either PPS time or
-		 * PPS frequency synchronization requested
+		/*
+		 * PPS signal lost when either PPS time or PPS frequency
+		 * synchronization requested
 		 */
 		|| ((status & (STA_PPSFREQ|STA_PPSTIME))
 			&& !(status & STA_PPSSIGNAL))
-		/* PPS jitter exceeded when
-		 * PPS time synchronization requested */
+		/*
+		 * PPS jitter exceeded when PPS time synchronization
+		 * requested
+		 */
 		|| ((status & (STA_PPSTIME|STA_PPSJITTER))
 			== (STA_PPSTIME|STA_PPSJITTER))
-		/* PPS wander exceeded or calibration error when
-		 * PPS frequency synchronization requested
+		/*
+		 * PPS wander exceeded or calibration error when PPS
+		 * frequency synchronization requested
 		 */
 		|| ((status & STA_PPSFREQ)
 			&& (status & (STA_PPSWANDER|STA_PPSERROR)));
 }
 
-static inline void pps_fill_timex(struct __kernel_timex *txc)
+static inline void pps_fill_timex(struct ntp_data *ntpdata, struct __kernel_timex *txc)
 {
-	txc->ppsfreq	   = shift_right((pps_freq >> PPM_SCALE_INV_SHIFT) *
+	txc->ppsfreq	   = shift_right((ntpdata->pps_freq >> PPM_SCALE_INV_SHIFT) *
 					 PPM_SCALE_INV, NTP_SCALE_SHIFT);
-	txc->jitter	   = pps_jitter;
-	if (!(time_status & STA_NANO))
-		txc->jitter = pps_jitter / NSEC_PER_USEC;
-	txc->shift	   = pps_shift;
-	txc->stabil	   = pps_stabil;
-	txc->jitcnt	   = pps_jitcnt;
-	txc->calcnt	   = pps_calcnt;
-	txc->errcnt	   = pps_errcnt;
-	txc->stbcnt	   = pps_stbcnt;
+	txc->jitter	   = ntpdata->pps_jitter;
+	if (!(ntpdata->time_status & STA_NANO))
+		txc->jitter = ntpdata->pps_jitter / NSEC_PER_USEC;
+	txc->shift	   = ntpdata->pps_shift;
+	txc->stabil	   = ntpdata->pps_stabil;
+	txc->jitcnt	   = ntpdata->pps_jitcnt;
+	txc->calcnt	   = ntpdata->pps_calcnt;
+	txc->errcnt	   = ntpdata->pps_errcnt;
+	txc->stbcnt	   = ntpdata->pps_stbcnt;
 }
 
 #else /* !CONFIG_NTP_PPS */
 
-static inline s64 ntp_offset_chunk(s64 offset)
+static inline s64 ntp_offset_chunk(struct ntp_data *ntpdata, s64 offset)
 {
-	return shift_right(offset, SHIFT_PLL + time_constant);
+	return shift_right(offset, SHIFT_PLL + ntpdata->time_constant);
 }
 
-static inline void pps_reset_freq_interval(void) {}
-static inline void pps_clear(void) {}
-static inline void pps_dec_valid(void) {}
-static inline void pps_set_freq(s64 freq) {}
+static inline void pps_reset_freq_interval(struct ntp_data *ntpdata) {}
+static inline void pps_clear(struct ntp_data *ntpdata) {}
+static inline void pps_dec_valid(struct ntp_data *ntpdata) {}
+static inline void pps_set_freq(struct ntp_data *ntpdata) {}
 
-static inline int is_error_status(int status)
+static inline bool is_error_status(int status)
 {
 	return status & (STA_UNSYNC|STA_CLOCKERR);
 }
 
-static inline void pps_fill_timex(struct __kernel_timex *txc)
+static inline void pps_fill_timex(struct ntp_data *ntpdata, struct __kernel_timex *txc)
 {
 	/* PPS is not implemented, so these are zero */
 	txc->ppsfreq	   = 0;
@@ -237,138 +241,123 @@ static inline void pps_fill_timex(struct __kernel_timex *txc)
 
 #endif /* CONFIG_NTP_PPS */
 
-
-/**
- * ntp_synced - Returns 1 if the NTP status is not UNSYNC
- *
- */
-static inline int ntp_synced(void)
-{
-	return !(time_status & STA_UNSYNC);
-}
-
-
 /*
- * NTP methods:
+ * Update tick_length and tick_length_base, based on tick_usec, ntp_tick_adj and
+ * time_freq:
  */
-
-/*
- * Update (tick_length, tick_length_base, tick_nsec), based
- * on (tick_usec, ntp_tick_adj, time_freq):
- */
-static void ntp_update_frequency(void)
+static void ntp_update_frequency(struct ntp_data *ntpdata)
 {
-	u64 second_length;
-	u64 new_base;
+	u64 second_length, new_base, tick_usec = (u64)ntpdata->tick_usec;
 
-	second_length		 = (u64)(tick_usec * NSEC_PER_USEC * USER_HZ)
-						<< NTP_SCALE_SHIFT;
+	second_length		 = (u64)(tick_usec * NSEC_PER_USEC * USER_HZ) << NTP_SCALE_SHIFT;
 
-	second_length		+= ntp_tick_adj;
-	second_length		+= time_freq;
+	second_length		+= ntpdata->ntp_tick_adj;
+	second_length		+= ntpdata->time_freq;
 
-	tick_nsec		 = div_u64(second_length, HZ) >> NTP_SCALE_SHIFT;
 	new_base		 = div_u64(second_length, NTP_INTERVAL_FREQ);
 
 	/*
-	 * Don't wait for the next second_overflow, apply
-	 * the change to the tick length immediately:
+	 * Don't wait for the next second_overflow, apply the change to the
+	 * tick length immediately:
 	 */
-	tick_length		+= new_base - tick_length_base;
-	tick_length_base	 = new_base;
+	ntpdata->tick_length		+= new_base - ntpdata->tick_length_base;
+	ntpdata->tick_length_base	 = new_base;
 }
 
-static inline s64 ntp_update_offset_fll(s64 offset64, long secs)
+static inline s64 ntp_update_offset_fll(struct ntp_data *ntpdata, s64 offset64, long secs)
 {
-	time_status &= ~STA_MODE;
+	ntpdata->time_status &= ~STA_MODE;
 
 	if (secs < MINSEC)
 		return 0;
 
-	if (!(time_status & STA_FLL) && (secs <= MAXSEC))
+	if (!(ntpdata->time_status & STA_FLL) && (secs <= MAXSEC))
 		return 0;
 
-	time_status |= STA_MODE;
+	ntpdata->time_status |= STA_MODE;
 
 	return div64_long(offset64 << (NTP_SCALE_SHIFT - SHIFT_FLL), secs);
 }
 
-static void ntp_update_offset(long offset)
+static void ntp_update_offset(struct ntp_data *ntpdata, long offset)
 {
-	s64 freq_adj;
-	s64 offset64;
-	long secs;
+	s64 freq_adj, offset64;
+	long secs, real_secs;
 
-	if (!(time_status & STA_PLL))
+	if (!(ntpdata->time_status & STA_PLL))
 		return;
 
-	if (!(time_status & STA_NANO)) {
+	if (!(ntpdata->time_status & STA_NANO)) {
 		/* Make sure the multiplication below won't overflow */
 		offset = clamp(offset, -USEC_PER_SEC, USEC_PER_SEC);
 		offset *= NSEC_PER_USEC;
 	}
 
-	/*
-	 * Scale the phase adjustment and
-	 * clamp to the operating range.
-	 */
+	/* Scale the phase adjustment and clamp to the operating range. */
 	offset = clamp(offset, -MAXPHASE, MAXPHASE);
 
 	/*
 	 * Select how the frequency is to be controlled
 	 * and in which mode (PLL or FLL).
 	 */
-	secs = (long)(__ktime_get_real_seconds() - time_reftime);
-	if (unlikely(time_status & STA_FREQHOLD))
+	real_secs = __ktime_get_real_seconds();
+	secs = (long)(real_secs - ntpdata->time_reftime);
+	if (unlikely(ntpdata->time_status & STA_FREQHOLD))
 		secs = 0;
 
-	time_reftime = __ktime_get_real_seconds();
+	ntpdata->time_reftime = real_secs;
 
 	offset64    = offset;
-	freq_adj    = ntp_update_offset_fll(offset64, secs);
+	freq_adj    = ntp_update_offset_fll(ntpdata, offset64, secs);
 
 	/*
 	 * Clamp update interval to reduce PLL gain with low
 	 * sampling rate (e.g. intermittent network connection)
 	 * to avoid instability.
 	 */
-	if (unlikely(secs > 1 << (SHIFT_PLL + 1 + time_constant)))
-		secs = 1 << (SHIFT_PLL + 1 + time_constant);
+	if (unlikely(secs > 1 << (SHIFT_PLL + 1 + ntpdata->time_constant)))
+		secs = 1 << (SHIFT_PLL + 1 + ntpdata->time_constant);
 
 	freq_adj    += (offset64 * secs) <<
-			(NTP_SCALE_SHIFT - 2 * (SHIFT_PLL + 2 + time_constant));
+			(NTP_SCALE_SHIFT - 2 * (SHIFT_PLL + 2 + ntpdata->time_constant));
 
-	freq_adj    = min(freq_adj + time_freq, MAXFREQ_SCALED);
+	freq_adj    = min(freq_adj + ntpdata->time_freq, MAXFREQ_SCALED);
 
-	time_freq   = max(freq_adj, -MAXFREQ_SCALED);
+	ntpdata->time_freq   = max(freq_adj, -MAXFREQ_SCALED);
 
-	time_offset = div_s64(offset64 << NTP_SCALE_SHIFT, NTP_INTERVAL_FREQ);
+	ntpdata->time_offset = div_s64(offset64 << NTP_SCALE_SHIFT, NTP_INTERVAL_FREQ);
 }
 
-/**
- * ntp_clear - Clears the NTP state variables
- */
-void ntp_clear(void)
+static void __ntp_clear(struct ntp_data *ntpdata)
 {
-	time_adjust	= 0;		/* stop active adjtime() */
-	time_status	|= STA_UNSYNC;
-	time_maxerror	= NTP_PHASE_LIMIT;
-	time_esterror	= NTP_PHASE_LIMIT;
+	/* Stop active adjtime() */
+	ntpdata->time_adjust	= 0;
+	ntpdata->time_status	|= STA_UNSYNC;
+	ntpdata->time_maxerror	= NTP_PHASE_LIMIT;
+	ntpdata->time_esterror	= NTP_PHASE_LIMIT;
 
-	ntp_update_frequency();
+	ntp_update_frequency(ntpdata);
 
-	tick_length	= tick_length_base;
-	time_offset	= 0;
+	ntpdata->tick_length	= ntpdata->tick_length_base;
+	ntpdata->time_offset	= 0;
 
-	ntp_next_leap_sec = TIME64_MAX;
+	ntpdata->ntp_next_leap_sec = TIME64_MAX;
 	/* Clear PPS state variables */
-	pps_clear();
+	pps_clear(ntpdata);
+}
+
+/**
+ * ntp_clear - Clears the NTP state variables
+ */
+void ntp_clear(void)
+{
+	__ntp_clear(&tk_ntp_data);
 }
 
 
 u64 ntp_tick_length(void)
 {
-	return tick_length;
+	return tk_ntp_data.tick_length;
 }
 
 /**
@@ -379,16 +368,17 @@ u64 ntp_tick_length(void)
  */
 ktime_t ntp_get_next_leap(void)
 {
+	struct ntp_data *ntpdata = &tk_ntp_data;
 	ktime_t ret;
 
-	if ((time_state == TIME_INS) && (time_status & STA_INS))
-		return ktime_set(ntp_next_leap_sec, 0);
+	if ((ntpdata->time_state == TIME_INS) && (ntpdata->time_status & STA_INS))
+		return ktime_set(ntpdata->ntp_next_leap_sec, 0);
 	ret = KTIME_MAX;
 	return ret;
 }
 
 /*
- * this routine handles the overflow of the microsecond field
+ * This routine handles the overflow of the microsecond field
  *
  * The tricky bits of code to handle the accurate clock support
  * were provided by Dave Mills (Mills@UDEL.EDU) of NTP fame.
@@ -399,6 +389,7 @@ ktime_t ntp_get_next_leap(void)
  */
 int second_overflow(time64_t secs)
 {
+	struct ntp_data *ntpdata = &tk_ntp_data;
 	s64 delta;
 	int leap = 0;
 	s32 rem;
@@ -408,87 +399,84 @@ int second_overflow(time64_t secs)
 	 * day, the system clock is set back one second; if in leap-delete
 	 * state, the system clock is set ahead one second.
 	 */
-	switch (time_state) {
+	switch (ntpdata->time_state) {
 	case TIME_OK:
-		if (time_status & STA_INS) {
-			time_state = TIME_INS;
+		if (ntpdata->time_status & STA_INS) {
+			ntpdata->time_state = TIME_INS;
 			div_s64_rem(secs, SECS_PER_DAY, &rem);
-			ntp_next_leap_sec = secs + SECS_PER_DAY - rem;
-		} else if (time_status & STA_DEL) {
-			time_state = TIME_DEL;
+			ntpdata->ntp_next_leap_sec = secs + SECS_PER_DAY - rem;
+		} else if (ntpdata->time_status & STA_DEL) {
+			ntpdata->time_state = TIME_DEL;
 			div_s64_rem(secs + 1, SECS_PER_DAY, &rem);
-			ntp_next_leap_sec = secs + SECS_PER_DAY - rem;
+			ntpdata->ntp_next_leap_sec = secs + SECS_PER_DAY - rem;
 		}
 		break;
 	case TIME_INS:
-		if (!(time_status & STA_INS)) {
-			ntp_next_leap_sec = TIME64_MAX;
-			time_state = TIME_OK;
-		} else if (secs == ntp_next_leap_sec) {
+		if (!(ntpdata->time_status & STA_INS)) {
+			ntpdata->ntp_next_leap_sec = TIME64_MAX;
+			ntpdata->time_state = TIME_OK;
+		} else if (secs == ntpdata->ntp_next_leap_sec) {
 			leap = -1;
-			time_state = TIME_OOP;
-			printk(KERN_NOTICE
-				"Clock: inserting leap second 23:59:60 UTC\n");
+			ntpdata->time_state = TIME_OOP;
+			pr_notice("Clock: inserting leap second 23:59:60 UTC\n");
 		}
 		break;
 	case TIME_DEL:
-		if (!(time_status & STA_DEL)) {
-			ntp_next_leap_sec = TIME64_MAX;
-			time_state = TIME_OK;
-		} else if (secs == ntp_next_leap_sec) {
+		if (!(ntpdata->time_status & STA_DEL)) {
+			ntpdata->ntp_next_leap_sec = TIME64_MAX;
+			ntpdata->time_state = TIME_OK;
+		} else if (secs == ntpdata->ntp_next_leap_sec) {
 			leap = 1;
-			ntp_next_leap_sec = TIME64_MAX;
-			time_state = TIME_WAIT;
-			printk(KERN_NOTICE
-				"Clock: deleting leap second 23:59:59 UTC\n");
+			ntpdata->ntp_next_leap_sec = TIME64_MAX;
+			ntpdata->time_state = TIME_WAIT;
+			pr_notice("Clock: deleting leap second 23:59:59 UTC\n");
 		}
 		break;
 	case TIME_OOP:
-		ntp_next_leap_sec = TIME64_MAX;
-		time_state = TIME_WAIT;
+		ntpdata->ntp_next_leap_sec = TIME64_MAX;
+		ntpdata->time_state = TIME_WAIT;
 		break;
 	case TIME_WAIT:
-		if (!(time_status & (STA_INS | STA_DEL)))
-			time_state = TIME_OK;
+		if (!(ntpdata->time_status & (STA_INS | STA_DEL)))
+			ntpdata->time_state = TIME_OK;
 		break;
 	}
 
-
 	/* Bump the maxerror field */
-	time_maxerror += MAXFREQ / NSEC_PER_USEC;
-	if (time_maxerror > NTP_PHASE_LIMIT) {
-		time_maxerror = NTP_PHASE_LIMIT;
-		time_status |= STA_UNSYNC;
+	ntpdata->time_maxerror += MAXFREQ / NSEC_PER_USEC;
+	if (ntpdata->time_maxerror > NTP_PHASE_LIMIT) {
+		ntpdata->time_maxerror = NTP_PHASE_LIMIT;
+		ntpdata->time_status |= STA_UNSYNC;
 	}
 
 	/* Compute the phase adjustment for the next second */
-	tick_length	 = tick_length_base;
+	ntpdata->tick_length	 = ntpdata->tick_length_base;
 
-	delta		 = ntp_offset_chunk(time_offset);
-	time_offset	-= delta;
-	tick_length	+= delta;
+	delta			 = ntp_offset_chunk(ntpdata, ntpdata->time_offset);
+	ntpdata->time_offset	-= delta;
+	ntpdata->tick_length	+= delta;
 
 	/* Check PPS signal */
-	pps_dec_valid();
+	pps_dec_valid(ntpdata);
 
-	if (!time_adjust)
+	if (!ntpdata->time_adjust)
 		goto out;
 
-	if (time_adjust > MAX_TICKADJ) {
-		time_adjust -= MAX_TICKADJ;
-		tick_length += MAX_TICKADJ_SCALED;
+	if (ntpdata->time_adjust > MAX_TICKADJ) {
+		ntpdata->time_adjust -= MAX_TICKADJ;
+		ntpdata->tick_length += MAX_TICKADJ_SCALED;
 		goto out;
 	}
 
-	if (time_adjust < -MAX_TICKADJ) {
-		time_adjust += MAX_TICKADJ;
-		tick_length -= MAX_TICKADJ_SCALED;
+	if (ntpdata->time_adjust < -MAX_TICKADJ) {
+		ntpdata->time_adjust += MAX_TICKADJ;
+		ntpdata->tick_length -= MAX_TICKADJ_SCALED;
 		goto out;
 	}
 
-	tick_length += (s64)(time_adjust * NSEC_PER_USEC / NTP_INTERVAL_FREQ)
-							 << NTP_SCALE_SHIFT;
-	time_adjust = 0;
+	ntpdata->tick_length += (s64)(ntpdata->time_adjust * NSEC_PER_USEC / NTP_INTERVAL_FREQ)
+				<< NTP_SCALE_SHIFT;
+	ntpdata->time_adjust = 0;
 
 out:
 	return leap;
@@ -611,6 +599,15 @@ static inline int update_rtc(struct timespec64 *to_set, unsigned long *offset_ns
 }
 #endif
 
+/**
+ * ntp_synced - Tells whether the NTP status is not UNSYNC
+ * Returns:	true if not UNSYNC, false otherwise
+ */
+static inline bool ntp_synced(void)
+{
+	return !(tk_ntp_data.time_status & STA_UNSYNC);
+}
+
 /*
  * If we have an externally synchronized Linux clock, then update RTC clock
  * accordingly every ~11 minutes. Generally RTCs can only store second
@@ -691,162 +688,156 @@ static inline void __init ntp_init_cmos_sync(void) { }
 /*
  * Propagate a new txc->status value into the NTP state:
  */
-static inline void process_adj_status(const struct __kernel_timex *txc)
+static inline void process_adj_status(struct ntp_data *ntpdata, const struct __kernel_timex *txc)
 {
-	if ((time_status & STA_PLL) && !(txc->status & STA_PLL)) {
-		time_state = TIME_OK;
-		time_status = STA_UNSYNC;
-		ntp_next_leap_sec = TIME64_MAX;
-		/* restart PPS frequency calibration */
-		pps_reset_freq_interval();
+	if ((ntpdata->time_status & STA_PLL) && !(txc->status & STA_PLL)) {
+		ntpdata->time_state = TIME_OK;
+		ntpdata->time_status = STA_UNSYNC;
+		ntpdata->ntp_next_leap_sec = TIME64_MAX;
+		/* Restart PPS frequency calibration */
+		pps_reset_freq_interval(ntpdata);
 	}
 
 	/*
 	 * If we turn on PLL adjustments then reset the
 	 * reference time to current time.
 	 */
-	if (!(time_status & STA_PLL) && (txc->status & STA_PLL))
-		time_reftime = __ktime_get_real_seconds();
+	if (!(ntpdata->time_status & STA_PLL) && (txc->status & STA_PLL))
+		ntpdata->time_reftime = __ktime_get_real_seconds();
 
 	/* only set allowed bits */
-	time_status &= STA_RONLY;
-	time_status |= txc->status & ~STA_RONLY;
+	ntpdata->time_status &= STA_RONLY;
+	ntpdata->time_status |= txc->status & ~STA_RONLY;
 }
 
-
-static inline void process_adjtimex_modes(const struct __kernel_timex *txc,
+static inline void process_adjtimex_modes(struct ntp_data *ntpdata, const struct __kernel_timex *txc,
 					  s32 *time_tai)
 {
 	if (txc->modes & ADJ_STATUS)
-		process_adj_status(txc);
+		process_adj_status(ntpdata, txc);
 
 	if (txc->modes & ADJ_NANO)
-		time_status |= STA_NANO;
+		ntpdata->time_status |= STA_NANO;
 
 	if (txc->modes & ADJ_MICRO)
-		time_status &= ~STA_NANO;
+		ntpdata->time_status &= ~STA_NANO;
 
 	if (txc->modes & ADJ_FREQUENCY) {
-		time_freq = txc->freq * PPM_SCALE;
-		time_freq = min(time_freq, MAXFREQ_SCALED);
-		time_freq = max(time_freq, -MAXFREQ_SCALED);
-		/* update pps_freq */
-		pps_set_freq(time_freq);
+		ntpdata->time_freq = txc->freq * PPM_SCALE;
+		ntpdata->time_freq = min(ntpdata->time_freq, MAXFREQ_SCALED);
+		ntpdata->time_freq = max(ntpdata->time_freq, -MAXFREQ_SCALED);
+		/* Update pps_freq */
+		pps_set_freq(ntpdata);
 	}
 
 	if (txc->modes & ADJ_MAXERROR)
-		time_maxerror = clamp(txc->maxerror, 0, NTP_PHASE_LIMIT);
+		ntpdata->time_maxerror = clamp(txc->maxerror, 0, NTP_PHASE_LIMIT);
 
 	if (txc->modes & ADJ_ESTERROR)
-		time_esterror = clamp(txc->esterror, 0, NTP_PHASE_LIMIT);
+		ntpdata->time_esterror = clamp(txc->esterror, 0, NTP_PHASE_LIMIT);
 
 	if (txc->modes & ADJ_TIMECONST) {
-		time_constant = clamp(txc->constant, 0, MAXTC);
-		if (!(time_status & STA_NANO))
-			time_constant += 4;
-		time_constant = clamp(time_constant, 0, MAXTC);
+		ntpdata->time_constant = clamp(txc->constant, 0, MAXTC);
+		if (!(ntpdata->time_status & STA_NANO))
+			ntpdata->time_constant += 4;
+		ntpdata->time_constant = clamp(ntpdata->time_constant, 0, MAXTC);
 	}
 
-	if (txc->modes & ADJ_TAI &&
-			txc->constant >= 0 && txc->constant <= MAX_TAI_OFFSET)
+	if (txc->modes & ADJ_TAI && txc->constant >= 0 && txc->constant <= MAX_TAI_OFFSET)
 		*time_tai = txc->constant;
 
 	if (txc->modes & ADJ_OFFSET)
-		ntp_update_offset(txc->offset);
+		ntp_update_offset(ntpdata, txc->offset);
 
 	if (txc->modes & ADJ_TICK)
-		tick_usec = txc->tick;
+		ntpdata->tick_usec = txc->tick;
 
 	if (txc->modes & (ADJ_TICK|ADJ_FREQUENCY|ADJ_OFFSET))
-		ntp_update_frequency();
+		ntp_update_frequency(ntpdata);
 }
 
-
 /*
- * adjtimex mainly allows reading (and writing, if superuser) of
+ * adjtimex() mainly allows reading (and writing, if superuser) of
  * kernel time-keeping variables. used by xntpd.
  */
 int __do_adjtimex(struct __kernel_timex *txc, const struct timespec64 *ts,
 		  s32 *time_tai, struct audit_ntp_data *ad)
 {
+	struct ntp_data *ntpdata = &tk_ntp_data;
 	int result;
 
 	if (txc->modes & ADJ_ADJTIME) {
-		long save_adjust = time_adjust;
+		long save_adjust = ntpdata->time_adjust;
 
 		if (!(txc->modes & ADJ_OFFSET_READONLY)) {
 			/* adjtime() is independent from ntp_adjtime() */
-			time_adjust = txc->offset;
-			ntp_update_frequency();
+			ntpdata->time_adjust = txc->offset;
+			ntp_update_frequency(ntpdata);
 
 			audit_ntp_set_old(ad, AUDIT_NTP_ADJUST,	save_adjust);
-			audit_ntp_set_new(ad, AUDIT_NTP_ADJUST,	time_adjust);
+			audit_ntp_set_new(ad, AUDIT_NTP_ADJUST,	ntpdata->time_adjust);
 		}
 		txc->offset = save_adjust;
 	} else {
 		/* If there are input parameters, then process them: */
 		if (txc->modes) {
-			audit_ntp_set_old(ad, AUDIT_NTP_OFFSET,	time_offset);
-			audit_ntp_set_old(ad, AUDIT_NTP_FREQ,	time_freq);
-			audit_ntp_set_old(ad, AUDIT_NTP_STATUS,	time_status);
+			audit_ntp_set_old(ad, AUDIT_NTP_OFFSET,	ntpdata->time_offset);
+			audit_ntp_set_old(ad, AUDIT_NTP_FREQ,	ntpdata->time_freq);
+			audit_ntp_set_old(ad, AUDIT_NTP_STATUS,	ntpdata->time_status);
 			audit_ntp_set_old(ad, AUDIT_NTP_TAI,	*time_tai);
-			audit_ntp_set_old(ad, AUDIT_NTP_TICK,	tick_usec);
+			audit_ntp_set_old(ad, AUDIT_NTP_TICK,	ntpdata->tick_usec);
 
-			process_adjtimex_modes(txc, time_tai);
+			process_adjtimex_modes(ntpdata, txc, time_tai);
 
-			audit_ntp_set_new(ad, AUDIT_NTP_OFFSET,	time_offset);
-			audit_ntp_set_new(ad, AUDIT_NTP_FREQ,	time_freq);
-			audit_ntp_set_new(ad, AUDIT_NTP_STATUS,	time_status);
+			audit_ntp_set_new(ad, AUDIT_NTP_OFFSET,	ntpdata->time_offset);
+			audit_ntp_set_new(ad, AUDIT_NTP_FREQ,	ntpdata->time_freq);
+			audit_ntp_set_new(ad, AUDIT_NTP_STATUS,	ntpdata->time_status);
 			audit_ntp_set_new(ad, AUDIT_NTP_TAI,	*time_tai);
-			audit_ntp_set_new(ad, AUDIT_NTP_TICK,	tick_usec);
+			audit_ntp_set_new(ad, AUDIT_NTP_TICK,	ntpdata->tick_usec);
 		}
 
-		txc->offset = shift_right(time_offset * NTP_INTERVAL_FREQ,
-				  NTP_SCALE_SHIFT);
-		if (!(time_status & STA_NANO))
+		txc->offset = shift_right(ntpdata->time_offset * NTP_INTERVAL_FREQ, NTP_SCALE_SHIFT);
+		if (!(ntpdata->time_status & STA_NANO))
 			txc->offset = (u32)txc->offset / NSEC_PER_USEC;
 	}
 
-	result = time_state;	/* mostly `TIME_OK' */
-	/* check for errors */
-	if (is_error_status(time_status))
+	result = ntpdata->time_state;
+	if (is_error_status(ntpdata->time_status))
 		result = TIME_ERROR;
 
-	txc->freq	   = shift_right((time_freq >> PPM_SCALE_INV_SHIFT) *
+	txc->freq	   = shift_right((ntpdata->time_freq >> PPM_SCALE_INV_SHIFT) *
 					 PPM_SCALE_INV, NTP_SCALE_SHIFT);
-	txc->maxerror	   = time_maxerror;
-	txc->esterror	   = time_esterror;
-	txc->status	   = time_status;
-	txc->constant	   = time_constant;
+	txc->maxerror	   = ntpdata->time_maxerror;
+	txc->esterror	   = ntpdata->time_esterror;
+	txc->status	   = ntpdata->time_status;
+	txc->constant	   = ntpdata->time_constant;
 	txc->precision	   = 1;
 	txc->tolerance	   = MAXFREQ_SCALED / PPM_SCALE;
-	txc->tick	   = tick_usec;
+	txc->tick	   = ntpdata->tick_usec;
 	txc->tai	   = *time_tai;
 
-	/* fill PPS status fields */
-	pps_fill_timex(txc);
+	/* Fill PPS status fields */
+	pps_fill_timex(ntpdata, txc);
 
 	txc->time.tv_sec = ts->tv_sec;
 	txc->time.tv_usec = ts->tv_nsec;
-	if (!(time_status & STA_NANO))
+	if (!(ntpdata->time_status & STA_NANO))
 		txc->time.tv_usec = ts->tv_nsec / NSEC_PER_USEC;
 
 	/* Handle leapsec adjustments */
-	if (unlikely(ts->tv_sec >= ntp_next_leap_sec)) {
-		if ((time_state == TIME_INS) && (time_status & STA_INS)) {
+	if (unlikely(ts->tv_sec >= ntpdata->ntp_next_leap_sec)) {
+		if ((ntpdata->time_state == TIME_INS) && (ntpdata->time_status & STA_INS)) {
 			result = TIME_OOP;
 			txc->tai++;
 			txc->time.tv_sec--;
 		}
-		if ((time_state == TIME_DEL) && (time_status & STA_DEL)) {
+		if ((ntpdata->time_state == TIME_DEL) && (ntpdata->time_status & STA_DEL)) {
 			result = TIME_WAIT;
 			txc->tai--;
 			txc->time.tv_sec++;
 		}
-		if ((time_state == TIME_OOP) &&
-					(ts->tv_sec == ntp_next_leap_sec)) {
+		if ((ntpdata->time_state == TIME_OOP) && (ts->tv_sec == ntpdata->ntp_next_leap_sec))
 			result = TIME_WAIT;
-		}
 	}
 
 	return result;
@@ -854,17 +845,21 @@ int __do_adjtimex(struct __kernel_timex *txc, const struct timespec64 *ts,
 
 #ifdef	CONFIG_NTP_PPS
 
-/* actually struct pps_normtime is good old struct timespec, but it is
+/*
+ * struct pps_normtime is basically a struct timespec, but it is
  * semantically different (and it is the reason why it was invented):
  * pps_normtime.nsec has a range of ( -NSEC_PER_SEC / 2, NSEC_PER_SEC / 2 ]
- * while timespec.tv_nsec has a range of [0, NSEC_PER_SEC) */
+ * while timespec.tv_nsec has a range of [0, NSEC_PER_SEC)
+ */
 struct pps_normtime {
 	s64		sec;	/* seconds */
 	long		nsec;	/* nanoseconds */
 };
 
-/* normalize the timestamp so that nsec is in the
-   ( -NSEC_PER_SEC / 2, NSEC_PER_SEC / 2 ] interval */
+/*
+ * Normalize the timestamp so that nsec is in the
+ * [ -NSEC_PER_SEC / 2, NSEC_PER_SEC / 2 ] interval
+ */
 static inline struct pps_normtime pps_normalize_ts(struct timespec64 ts)
 {
 	struct pps_normtime norm = {
@@ -880,54 +875,57 @@ static inline struct pps_normtime pps_normalize_ts(struct timespec64 ts)
 	return norm;
 }
 
-/* get current phase correction and jitter */
-static inline long pps_phase_filter_get(long *jitter)
+/* Get current phase correction and jitter */
+static inline long pps_phase_filter_get(struct ntp_data *ntpdata, long *jitter)
 {
-	*jitter = pps_tf[0] - pps_tf[1];
+	*jitter = ntpdata->pps_tf[0] - ntpdata->pps_tf[1];
 	if (*jitter < 0)
 		*jitter = -*jitter;
 
 	/* TODO: test various filters */
-	return pps_tf[0];
+	return ntpdata->pps_tf[0];
 }
 
-/* add the sample to the phase filter */
-static inline void pps_phase_filter_add(long err)
+/* Add the sample to the phase filter */
+static inline void pps_phase_filter_add(struct ntp_data *ntpdata, long err)
 {
-	pps_tf[2] = pps_tf[1];
-	pps_tf[1] = pps_tf[0];
-	pps_tf[0] = err;
+	ntpdata->pps_tf[2] = ntpdata->pps_tf[1];
+	ntpdata->pps_tf[1] = ntpdata->pps_tf[0];
+	ntpdata->pps_tf[0] = err;
 }
 
-/* decrease frequency calibration interval length.
- * It is halved after four consecutive unstable intervals.
+/*
+ * Decrease frequency calibration interval length. It is halved after four
+ * consecutive unstable intervals.
  */
-static inline void pps_dec_freq_interval(void)
+static inline void pps_dec_freq_interval(struct ntp_data *ntpdata)
 {
-	if (--pps_intcnt <= -PPS_INTCOUNT) {
-		pps_intcnt = -PPS_INTCOUNT;
-		if (pps_shift > PPS_INTMIN) {
-			pps_shift--;
-			pps_intcnt = 0;
+	if (--ntpdata->pps_intcnt <= -PPS_INTCOUNT) {
+		ntpdata->pps_intcnt = -PPS_INTCOUNT;
+		if (ntpdata->pps_shift > PPS_INTMIN) {
+			ntpdata->pps_shift--;
+			ntpdata->pps_intcnt = 0;
 		}
 	}
 }
 
-/* increase frequency calibration interval length.
- * It is doubled after four consecutive stable intervals.
+/*
+ * Increase frequency calibration interval length. It is doubled after
+ * four consecutive stable intervals.
  */
-static inline void pps_inc_freq_interval(void)
+static inline void pps_inc_freq_interval(struct ntp_data *ntpdata)
 {
-	if (++pps_intcnt >= PPS_INTCOUNT) {
-		pps_intcnt = PPS_INTCOUNT;
-		if (pps_shift < PPS_INTMAX) {
-			pps_shift++;
-			pps_intcnt = 0;
+	if (++ntpdata->pps_intcnt >= PPS_INTCOUNT) {
+		ntpdata->pps_intcnt = PPS_INTCOUNT;
+		if (ntpdata->pps_shift < PPS_INTMAX) {
+			ntpdata->pps_shift++;
+			ntpdata->pps_intcnt = 0;
 		}
 	}
 }
 
-/* update clock frequency based on MONOTONIC_RAW clock PPS signal
+/*
+ * Update clock frequency based on MONOTONIC_RAW clock PPS signal
  * timestamps
  *
  * At the end of the calibration interval the difference between the
@@ -936,90 +934,88 @@ static inline void pps_inc_freq_interval(void)
  * too long, the data are discarded.
  * Returns the difference between old and new frequency values.
  */
-static long hardpps_update_freq(struct pps_normtime freq_norm)
+static long hardpps_update_freq(struct ntp_data *ntpdata, struct pps_normtime freq_norm)
 {
 	long delta, delta_mod;
 	s64 ftemp;
 
-	/* check if the frequency interval was too long */
-	if (freq_norm.sec > (2 << pps_shift)) {
-		time_status |= STA_PPSERROR;
-		pps_errcnt++;
-		pps_dec_freq_interval();
-		printk_deferred(KERN_ERR
-			"hardpps: PPSERROR: interval too long - %lld s\n",
-			freq_norm.sec);
+	/* Check if the frequency interval was too long */
+	if (freq_norm.sec > (2 << ntpdata->pps_shift)) {
+		ntpdata->time_status |= STA_PPSERROR;
+		ntpdata->pps_errcnt++;
+		pps_dec_freq_interval(ntpdata);
+		printk_deferred(KERN_ERR "hardpps: PPSERROR: interval too long - %lld s\n",
+				freq_norm.sec);
 		return 0;
 	}
 
-	/* here the raw frequency offset and wander (stability) is
-	 * calculated. If the wander is less than the wander threshold
-	 * the interval is increased; otherwise it is decreased.
+	/*
+	 * Here the raw frequency offset and wander (stability) is
+	 * calculated. If the wander is less than the wander threshold the
+	 * interval is increased; otherwise it is decreased.
 	 */
 	ftemp = div_s64(((s64)(-freq_norm.nsec)) << NTP_SCALE_SHIFT,
 			freq_norm.sec);
-	delta = shift_right(ftemp - pps_freq, NTP_SCALE_SHIFT);
-	pps_freq = ftemp;
+	delta = shift_right(ftemp - ntpdata->pps_freq, NTP_SCALE_SHIFT);
+	ntpdata->pps_freq = ftemp;
 	if (delta > PPS_MAXWANDER || delta < -PPS_MAXWANDER) {
-		printk_deferred(KERN_WARNING
-				"hardpps: PPSWANDER: change=%ld\n", delta);
-		time_status |= STA_PPSWANDER;
-		pps_stbcnt++;
-		pps_dec_freq_interval();
-	} else {	/* good sample */
-		pps_inc_freq_interval();
+		printk_deferred(KERN_WARNING "hardpps: PPSWANDER: change=%ld\n", delta);
+		ntpdata->time_status |= STA_PPSWANDER;
+		ntpdata->pps_stbcnt++;
+		pps_dec_freq_interval(ntpdata);
+	} else {
+		/* Good sample */
+		pps_inc_freq_interval(ntpdata);
 	}
 
-	/* the stability metric is calculated as the average of recent
-	 * frequency changes, but is used only for performance
-	 * monitoring
+	/*
+	 * The stability metric is calculated as the average of recent
+	 * frequency changes, but is used only for performance monitoring
 	 */
 	delta_mod = delta;
 	if (delta_mod < 0)
 		delta_mod = -delta_mod;
-	pps_stabil += (div_s64(((s64)delta_mod) <<
-				(NTP_SCALE_SHIFT - SHIFT_USEC),
-				NSEC_PER_USEC) - pps_stabil) >> PPS_INTMIN;
-
-	/* if enabled, the system clock frequency is updated */
-	if ((time_status & STA_PPSFREQ) != 0 &&
-	    (time_status & STA_FREQHOLD) == 0) {
-		time_freq = pps_freq;
-		ntp_update_frequency();
+	ntpdata->pps_stabil += (div_s64(((s64)delta_mod) << (NTP_SCALE_SHIFT - SHIFT_USEC),
+				     NSEC_PER_USEC) - ntpdata->pps_stabil) >> PPS_INTMIN;
+
+	/* If enabled, the system clock frequency is updated */
+	if ((ntpdata->time_status & STA_PPSFREQ) && !(ntpdata->time_status & STA_FREQHOLD)) {
+		ntpdata->time_freq = ntpdata->pps_freq;
+		ntp_update_frequency(ntpdata);
 	}
 
 	return delta;
 }
 
-/* correct REALTIME clock phase error against PPS signal */
-static void hardpps_update_phase(long error)
+/* Correct REALTIME clock phase error against PPS signal */
+static void hardpps_update_phase(struct ntp_data *ntpdata, long error)
 {
 	long correction = -error;
 	long jitter;
 
-	/* add the sample to the median filter */
-	pps_phase_filter_add(correction);
-	correction = pps_phase_filter_get(&jitter);
+	/* Add the sample to the median filter */
+	pps_phase_filter_add(ntpdata, correction);
+	correction = pps_phase_filter_get(ntpdata, &jitter);
 
-	/* Nominal jitter is due to PPS signal noise. If it exceeds the
+	/*
+	 * Nominal jitter is due to PPS signal noise. If it exceeds the
 	 * threshold, the sample is discarded; otherwise, if so enabled,
 	 * the time offset is updated.
 	 */
-	if (jitter > (pps_jitter << PPS_POPCORN)) {
-		printk_deferred(KERN_WARNING
-				"hardpps: PPSJITTER: jitter=%ld, limit=%ld\n",
-				jitter, (pps_jitter << PPS_POPCORN));
-		time_status |= STA_PPSJITTER;
-		pps_jitcnt++;
-	} else if (time_status & STA_PPSTIME) {
-		/* correct the time using the phase offset */
-		time_offset = div_s64(((s64)correction) << NTP_SCALE_SHIFT,
-				NTP_INTERVAL_FREQ);
-		/* cancel running adjtime() */
-		time_adjust = 0;
+	if (jitter > (ntpdata->pps_jitter << PPS_POPCORN)) {
+		printk_deferred(KERN_WARNING "hardpps: PPSJITTER: jitter=%ld, limit=%ld\n",
+				jitter, (ntpdata->pps_jitter << PPS_POPCORN));
+		ntpdata->time_status |= STA_PPSJITTER;
+		ntpdata->pps_jitcnt++;
+	} else if (ntpdata->time_status & STA_PPSTIME) {
+		/* Correct the time using the phase offset */
+		ntpdata->time_offset = div_s64(((s64)correction) << NTP_SCALE_SHIFT,
+					       NTP_INTERVAL_FREQ);
+		/* Cancel running adjtime() */
+		ntpdata->time_adjust = 0;
 	}
-	/* update jitter */
-	pps_jitter += (jitter - pps_jitter) >> PPS_INTMIN;
+	/* Update jitter */
+	ntpdata->pps_jitter += (jitter - ntpdata->pps_jitter) >> PPS_INTMIN;
 }
 
 /*
@@ -1037,60 +1033,62 @@ static void hardpps_update_phase(long error)
 void __hardpps(const struct timespec64 *phase_ts, const struct timespec64 *raw_ts)
 {
 	struct pps_normtime pts_norm, freq_norm;
+	struct ntp_data *ntpdata = &tk_ntp_data;
 
 	pts_norm = pps_normalize_ts(*phase_ts);
 
-	/* clear the error bits, they will be set again if needed */
-	time_status &= ~(STA_PPSJITTER | STA_PPSWANDER | STA_PPSERROR);
+	/* Clear the error bits, they will be set again if needed */
+	ntpdata->time_status &= ~(STA_PPSJITTER | STA_PPSWANDER | STA_PPSERROR);
 
 	/* indicate signal presence */
-	time_status |= STA_PPSSIGNAL;
-	pps_valid = PPS_VALID;
+	ntpdata->time_status |= STA_PPSSIGNAL;
+	ntpdata->pps_valid = PPS_VALID;
 
-	/* when called for the first time,
-	 * just start the frequency interval */
-	if (unlikely(pps_fbase.tv_sec == 0)) {
-		pps_fbase = *raw_ts;
+	/*
+	 * When called for the first time, just start the frequency
+	 * interval
+	 */
+	if (unlikely(ntpdata->pps_fbase.tv_sec == 0)) {
+		ntpdata->pps_fbase = *raw_ts;
 		return;
 	}
 
-	/* ok, now we have a base for frequency calculation */
-	freq_norm = pps_normalize_ts(timespec64_sub(*raw_ts, pps_fbase));
-
-	/* check that the signal is in the range
-	 * [1s - MAXFREQ us, 1s + MAXFREQ us], otherwise reject it */
-	if ((freq_norm.sec == 0) ||
-			(freq_norm.nsec > MAXFREQ * freq_norm.sec) ||
-			(freq_norm.nsec < -MAXFREQ * freq_norm.sec)) {
-		time_status |= STA_PPSJITTER;
-		/* restart the frequency calibration interval */
-		pps_fbase = *raw_ts;
+	/* Ok, now we have a base for frequency calculation */
+	freq_norm = pps_normalize_ts(timespec64_sub(*raw_ts, ntpdata->pps_fbase));
+
+	/*
+	 * Check that the signal is in the range
+	 * [1s - MAXFREQ us, 1s + MAXFREQ us], otherwise reject it
+	 */
+	if ((freq_norm.sec == 0) || (freq_norm.nsec > MAXFREQ * freq_norm.sec) ||
+	    (freq_norm.nsec < -MAXFREQ * freq_norm.sec)) {
+		ntpdata->time_status |= STA_PPSJITTER;
+		/* Restart the frequency calibration interval */
+		ntpdata->pps_fbase = *raw_ts;
 		printk_deferred(KERN_ERR "hardpps: PPSJITTER: bad pulse\n");
 		return;
 	}
 
-	/* signal is ok */
-
-	/* check if the current frequency interval is finished */
-	if (freq_norm.sec >= (1 << pps_shift)) {
-		pps_calcnt++;
-		/* restart the frequency calibration interval */
-		pps_fbase = *raw_ts;
-		hardpps_update_freq(freq_norm);
+	/* Signal is ok. Check if the current frequency interval is finished */
+	if (freq_norm.sec >= (1 << ntpdata->pps_shift)) {
+		ntpdata->pps_calcnt++;
+		/* Restart the frequency calibration interval */
+		ntpdata->pps_fbase = *raw_ts;
+		hardpps_update_freq(ntpdata, freq_norm);
 	}
 
-	hardpps_update_phase(pts_norm.nsec);
+	hardpps_update_phase(ntpdata, pts_norm.nsec);
 
 }
 #endif	/* CONFIG_NTP_PPS */
 
 static int __init ntp_tick_adj_setup(char *str)
 {
-	int rc = kstrtos64(str, 0, &ntp_tick_adj);
+	int rc = kstrtos64(str, 0, &tk_ntp_data.ntp_tick_adj);
 	if (rc)
 		return rc;
 
-	ntp_tick_adj <<= NTP_SCALE_SHIFT;
+	tk_ntp_data.ntp_tick_adj <<= NTP_SCALE_SHIFT;
 	return 1;
 }
 
diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c
index 6bcee4704059..50e8d04ab661 100644
--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -453,7 +453,6 @@ static void disarm_timer(struct k_itimer *timer, struct task_struct *p)
 	struct cpu_timer *ctmr = &timer->it.cpu;
 	struct posix_cputimer_base *base;
 
-	timer->it_active = 0;
 	if (!cpu_timer_dequeue(ctmr))
 		return;
 
@@ -494,19 +493,28 @@ static int posix_cpu_timer_del(struct k_itimer *timer)
 		 */
 		WARN_ON_ONCE(ctmr->head || timerqueue_node_queued(&ctmr->node));
 	} else {
-		if (timer->it.cpu.firing)
+		if (timer->it.cpu.firing) {
+			/*
+			 * Prevent signal delivery. The timer cannot be dequeued
+			 * because it is on the firing list which is not protected
+			 * by sighand->lock. The delivery path is waiting for
+			 * the timer lock. So go back, unlock and retry.
+			 */
+			timer->it.cpu.firing = false;
 			ret = TIMER_RETRY;
-		else
+		} else {
 			disarm_timer(timer, p);
-
+		}
 		unlock_task_sighand(p, &flags);
 	}
 
 out:
 	rcu_read_unlock();
-	if (!ret)
-		put_pid(ctmr->pid);
 
+	if (!ret) {
+		put_pid(ctmr->pid);
+		timer->it_status = POSIX_TIMER_DISARMED;
+	}
 	return ret;
 }
 
@@ -560,7 +568,7 @@ static void arm_timer(struct k_itimer *timer, struct task_struct *p)
 	struct cpu_timer *ctmr = &timer->it.cpu;
 	u64 newexp = cpu_timer_getexpires(ctmr);
 
-	timer->it_active = 1;
+	timer->it_status = POSIX_TIMER_ARMED;
 	if (!cpu_timer_enqueue(&base->tqhead, ctmr))
 		return;
 
@@ -586,29 +594,20 @@ static void cpu_timer_fire(struct k_itimer *timer)
 {
 	struct cpu_timer *ctmr = &timer->it.cpu;
 
-	timer->it_active = 0;
-	if (unlikely(timer->sigq == NULL)) {
+	timer->it_status = POSIX_TIMER_DISARMED;
+
+	if (unlikely(ctmr->nanosleep)) {
 		/*
 		 * This a special case for clock_nanosleep,
 		 * not a normal timer from sys_timer_create.
 		 */
 		wake_up_process(timer->it_process);
 		cpu_timer_setexpires(ctmr, 0);
-	} else if (!timer->it_interval) {
-		/*
-		 * One-shot timer.  Clear it as soon as it's fired.
-		 */
+	} else {
 		posix_timer_queue_signal(timer);
-		cpu_timer_setexpires(ctmr, 0);
-	} else if (posix_timer_queue_signal(timer)) {
-		/*
-		 * The signal did not get queued because the signal
-		 * was ignored, so we won't get any callback to
-		 * reload the timer.  But we need to keep it
-		 * ticking in case the signal is deliverable next time.
-		 */
-		posix_cpu_timer_rearm(timer);
-		++timer->it_requeue_pending;
+		/* Disable oneshot timers */
+		if (!timer->it_interval)
+			cpu_timer_setexpires(ctmr, 0);
 	}
 }
 
@@ -667,11 +666,17 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
 	old_expires = cpu_timer_getexpires(ctmr);
 
 	if (unlikely(timer->it.cpu.firing)) {
-		timer->it.cpu.firing = -1;
+		/*
+		 * Prevent signal delivery. The timer cannot be dequeued
+		 * because it is on the firing list which is not protected
+		 * by sighand->lock. The delivery path is waiting for
+		 * the timer lock. So go back, unlock and retry.
+		 */
+		timer->it.cpu.firing = false;
 		ret = TIMER_RETRY;
 	} else {
 		cpu_timer_dequeue(ctmr);
-		timer->it_active = 0;
+		timer->it_status = POSIX_TIMER_DISARMED;
 	}
 
 	/*
@@ -745,7 +750,7 @@ static void __posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec64 *i
 	 *  - Timers which expired, but the signal has not yet been
 	 *    delivered
 	 */
-	if (iv && ((timer->it_requeue_pending & REQUEUE_PENDING) || sigev_none))
+	if (iv && timer->it_status != POSIX_TIMER_ARMED)
 		expires = bump_cpu_timer(timer, now);
 	else
 		expires = cpu_timer_getexpires(&timer->it.cpu);
@@ -808,7 +813,7 @@ static u64 collect_timerqueue(struct timerqueue_head *head,
 		if (++i == MAX_COLLECTED || now < expires)
 			return expires;
 
-		ctmr->firing = 1;
+		ctmr->firing = true;
 		/* See posix_cpu_timer_wait_running() */
 		rcu_assign_pointer(ctmr->handling, current);
 		cpu_timer_dequeue(ctmr);
@@ -1363,7 +1368,7 @@ static void handle_posix_cpu_timers(struct task_struct *tsk)
 	 * timer call will interfere.
 	 */
 	list_for_each_entry_safe(timer, next, &firing, it.cpu.elist) {
-		int cpu_firing;
+		bool cpu_firing;
 
 		/*
 		 * spin_lock() is sufficient here even independent of the
@@ -1375,13 +1380,13 @@ static void handle_posix_cpu_timers(struct task_struct *tsk)
 		spin_lock(&timer->it_lock);
 		list_del_init(&timer->it.cpu.elist);
 		cpu_firing = timer->it.cpu.firing;
-		timer->it.cpu.firing = 0;
+		timer->it.cpu.firing = false;
 		/*
-		 * The firing flag is -1 if we collided with a reset
-		 * of the timer, which already reported this
-		 * almost-firing as an overrun.  So don't generate an event.
+		 * If the firing flag is cleared then this raced with a
+		 * timer rearm/delete operation. So don't generate an
+		 * event.
 		 */
-		if (likely(cpu_firing >= 0))
+		if (likely(cpu_firing))
 			cpu_timer_fire(timer);
 		/* See posix_cpu_timer_wait_running() */
 		rcu_assign_pointer(timer->it.cpu.handling, NULL);
@@ -1478,6 +1483,7 @@ static int do_cpu_nanosleep(const clockid_t which_clock, int flags,
 	timer.it_overrun = -1;
 	error = posix_cpu_timer_create(&timer);
 	timer.it_process = current;
+	timer.it.cpu.nanosleep = true;
 
 	if (!error) {
 		static struct itimerspec64 zero_it;
diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index 4576aaed13b2..881a9ce96af7 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -233,11 +233,12 @@ __initcall(init_posix_timers);
  * The siginfo si_overrun field and the return value of timer_getoverrun(2)
  * are of type int. Clamp the overrun value to INT_MAX
  */
-static inline int timer_overrun_to_int(struct k_itimer *timr, int baseval)
+static inline int timer_overrun_to_int(struct k_itimer *timr)
 {
-	s64 sum = timr->it_overrun_last + (s64)baseval;
+	if (timr->it_overrun_last > (s64)INT_MAX)
+		return INT_MAX;
 
-	return sum > (s64)INT_MAX ? INT_MAX : (int)sum;
+	return (int)timr->it_overrun_last;
 }
 
 static void common_hrtimer_rearm(struct k_itimer *timr)
@@ -249,62 +250,62 @@ static void common_hrtimer_rearm(struct k_itimer *timr)
 	hrtimer_restart(timer);
 }
 
+static bool __posixtimer_deliver_signal(struct kernel_siginfo *info, struct k_itimer *timr)
+{
+	guard(spinlock)(&timr->it_lock);
+
+	/*
+	 * Check if the timer is still alive or whether it got modified
+	 * since the signal was queued. In either case, don't rearm and
+	 * drop the signal.
+	 */
+	if (timr->it_signal_seq != timr->it_sigqueue_seq || WARN_ON_ONCE(!timr->it_signal))
+		return false;
+
+	if (!timr->it_interval || WARN_ON_ONCE(timr->it_status != POSIX_TIMER_REQUEUE_PENDING))
+		return true;
+
+	timr->kclock->timer_rearm(timr);
+	timr->it_status = POSIX_TIMER_ARMED;
+	timr->it_overrun_last = timr->it_overrun;
+	timr->it_overrun = -1LL;
+	++timr->it_signal_seq;
+	info->si_overrun = timer_overrun_to_int(timr);
+	return true;
+}
+
 /*
- * This function is called from the signal delivery code if
- * info->si_sys_private is not zero, which indicates that the timer has to
- * be rearmed. Restart the timer and update info::si_overrun.
+ * This function is called from the signal delivery code. It decides
+ * whether the signal should be dropped and rearms interval timers.  The
+ * timer can be unconditionally accessed as there is a reference held on
+ * it.
  */
-void posixtimer_rearm(struct kernel_siginfo *info)
+bool posixtimer_deliver_signal(struct kernel_siginfo *info, struct sigqueue *timer_sigq)
 {
-	struct k_itimer *timr;
-	unsigned long flags;
-
-	timr = lock_timer(info->si_tid, &flags);
-	if (!timr)
-		return;
+	struct k_itimer *timr = container_of(timer_sigq, struct k_itimer, sigq);
+	bool ret;
 
-	if (timr->it_interval && timr->it_requeue_pending == info->si_sys_private) {
-		timr->kclock->timer_rearm(timr);
+	/*
+	 * Release siglock to ensure proper locking order versus
+	 * timr::it_lock. Keep interrupts disabled.
+	 */
+	spin_unlock(&current->sighand->siglock);
 
-		timr->it_active = 1;
-		timr->it_overrun_last = timr->it_overrun;
-		timr->it_overrun = -1LL;
-		++timr->it_requeue_pending;
+	ret = __posixtimer_deliver_signal(info, timr);
 
-		info->si_overrun = timer_overrun_to_int(timr, info->si_overrun);
-	}
+	/* Drop the reference which was acquired when the signal was queued */
+	posixtimer_putref(timr);
 
-	unlock_timer(timr, flags);
+	spin_lock(&current->sighand->siglock);
+	return ret;
 }
 
-int posix_timer_queue_signal(struct k_itimer *timr)
+void posix_timer_queue_signal(struct k_itimer *timr)
 {
-	int ret, si_private = 0;
-	enum pid_type type;
-
 	lockdep_assert_held(&timr->it_lock);
 
-	timr->it_active = 0;
-	if (timr->it_interval)
-		si_private = ++timr->it_requeue_pending;
-
-	/*
-	 * FIXME: if ->sigq is queued we can race with
-	 * dequeue_signal()->posixtimer_rearm().
-	 *
-	 * If dequeue_signal() sees the "right" value of
-	 * si_sys_private it calls posixtimer_rearm().
-	 * We re-queue ->sigq and drop ->it_lock().
-	 * posixtimer_rearm() locks the timer
-	 * and re-schedules it while ->sigq is pending.
-	 * Not really bad, but not that we want.
-	 */
-	timr->sigq->info.si_sys_private = si_private;
-
-	type = !(timr->it_sigev_notify & SIGEV_THREAD_ID) ? PIDTYPE_TGID : PIDTYPE_PID;
-	ret = send_sigqueue(timr->sigq, timr->it_pid, type);
-	/* If we failed to send the signal the timer stops. */
-	return ret > 0;
+	timr->it_status = timr->it_interval ? POSIX_TIMER_REQUEUE_PENDING : POSIX_TIMER_DISARMED;
+	posixtimer_send_sigqueue(timr);
 }
 
 /*
@@ -317,62 +318,10 @@ int posix_timer_queue_signal(struct k_itimer *timr)
 static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer)
 {
 	struct k_itimer *timr = container_of(timer, struct k_itimer, it.real.timer);
-	enum hrtimer_restart ret = HRTIMER_NORESTART;
-	unsigned long flags;
-
-	spin_lock_irqsave(&timr->it_lock, flags);
-
-	if (posix_timer_queue_signal(timr)) {
-		/*
-		 * The signal was not queued due to SIG_IGN. As a
-		 * consequence the timer is not going to be rearmed from
-		 * the signal delivery path. But as a real signal handler
-		 * can be installed later the timer must be rearmed here.
-		 */
-		if (timr->it_interval != 0) {
-			ktime_t now = hrtimer_cb_get_time(timer);
-
-			/*
-			 * FIXME: What we really want, is to stop this
-			 * timer completely and restart it in case the
-			 * SIG_IGN is removed. This is a non trivial
-			 * change to the signal handling code.
-			 *
-			 * For now let timers with an interval less than a
-			 * jiffy expire every jiffy and recheck for a
-			 * valid signal handler.
-			 *
-			 * This avoids interrupt starvation in case of a
-			 * very small interval, which would expire the
-			 * timer immediately again.
-			 *
-			 * Moving now ahead of time by one jiffy tricks
-			 * hrtimer_forward() to expire the timer later,
-			 * while it still maintains the overrun accuracy
-			 * for the price of a slight inconsistency in the
-			 * timer_gettime() case. This is at least better
-			 * than a timer storm.
-			 *
-			 * Only required when high resolution timers are
-			 * enabled as the periodic tick based timers are
-			 * automatically aligned to the next tick.
-			 */
-			if (IS_ENABLED(CONFIG_HIGH_RES_TIMERS)) {
-				ktime_t kj = TICK_NSEC;
-
-				if (timr->it_interval < kj)
-					now = ktime_add(now, kj);
-			}
-
-			timr->it_overrun += hrtimer_forward(timer, now, timr->it_interval);
-			ret = HRTIMER_RESTART;
-			++timr->it_requeue_pending;
-			timr->it_active = 1;
-		}
-	}
 
-	unlock_timer(timr, flags);
-	return ret;
+	guard(spinlock_irqsave)(&timr->it_lock);
+	posix_timer_queue_signal(timr);
+	return HRTIMER_NORESTART;
 }
 
 static struct pid *good_sigevent(sigevent_t * event)
@@ -399,32 +348,27 @@ static struct pid *good_sigevent(sigevent_t * event)
 	}
 }
 
-static struct k_itimer * alloc_posix_timer(void)
+static struct k_itimer *alloc_posix_timer(void)
 {
 	struct k_itimer *tmr = kmem_cache_zalloc(posix_timers_cache, GFP_KERNEL);
 
 	if (!tmr)
 		return tmr;
-	if (unlikely(!(tmr->sigq = sigqueue_alloc()))) {
+
+	if (unlikely(!posixtimer_init_sigqueue(&tmr->sigq))) {
 		kmem_cache_free(posix_timers_cache, tmr);
 		return NULL;
 	}
-	clear_siginfo(&tmr->sigq->info);
+	rcuref_init(&tmr->rcuref, 1);
 	return tmr;
 }
 
-static void k_itimer_rcu_free(struct rcu_head *head)
-{
-	struct k_itimer *tmr = container_of(head, struct k_itimer, rcu);
-
-	kmem_cache_free(posix_timers_cache, tmr);
-}
-
-static void posix_timer_free(struct k_itimer *tmr)
+void posixtimer_free_timer(struct k_itimer *tmr)
 {
 	put_pid(tmr->it_pid);
-	sigqueue_free(tmr->sigq);
-	call_rcu(&tmr->rcu, k_itimer_rcu_free);
+	if (tmr->sigq.ucounts)
+		dec_rlimit_put_ucounts(tmr->sigq.ucounts, UCOUNT_RLIMIT_SIGPENDING);
+	kfree_rcu(tmr, rcu);
 }
 
 static void posix_timer_unhash_and_free(struct k_itimer *tmr)
@@ -432,7 +376,7 @@ static void posix_timer_unhash_and_free(struct k_itimer *tmr)
 	spin_lock(&hash_lock);
 	hlist_del_rcu(&tmr->t_hash);
 	spin_unlock(&hash_lock);
-	posix_timer_free(tmr);
+	posixtimer_putref(tmr);
 }
 
 static int common_timer_create(struct k_itimer *new_timer)
@@ -467,7 +411,7 @@ static int do_timer_create(clockid_t which_clock, struct sigevent *event,
 	 */
 	new_timer_id = posix_timer_add(new_timer);
 	if (new_timer_id < 0) {
-		posix_timer_free(new_timer);
+		posixtimer_free_timer(new_timer);
 		return new_timer_id;
 	}
 
@@ -485,18 +429,23 @@ static int do_timer_create(clockid_t which_clock, struct sigevent *event,
 			goto out;
 		}
 		new_timer->it_sigev_notify     = event->sigev_notify;
-		new_timer->sigq->info.si_signo = event->sigev_signo;
-		new_timer->sigq->info.si_value = event->sigev_value;
+		new_timer->sigq.info.si_signo = event->sigev_signo;
+		new_timer->sigq.info.si_value = event->sigev_value;
 	} else {
 		new_timer->it_sigev_notify     = SIGEV_SIGNAL;
-		new_timer->sigq->info.si_signo = SIGALRM;
-		memset(&new_timer->sigq->info.si_value, 0, sizeof(sigval_t));
-		new_timer->sigq->info.si_value.sival_int = new_timer->it_id;
+		new_timer->sigq.info.si_signo = SIGALRM;
+		memset(&new_timer->sigq.info.si_value, 0, sizeof(sigval_t));
+		new_timer->sigq.info.si_value.sival_int = new_timer->it_id;
 		new_timer->it_pid = get_pid(task_tgid(current));
 	}
 
-	new_timer->sigq->info.si_tid   = new_timer->it_id;
-	new_timer->sigq->info.si_code  = SI_TIMER;
+	if (new_timer->it_sigev_notify & SIGEV_THREAD_ID)
+		new_timer->it_pid_type = PIDTYPE_PID;
+	else
+		new_timer->it_pid_type = PIDTYPE_TGID;
+
+	new_timer->sigq.info.si_tid = new_timer->it_id;
+	new_timer->sigq.info.si_code = SI_TIMER;
 
 	if (copy_to_user(created_timer_id, &new_timer_id, sizeof (new_timer_id))) {
 		error = -EFAULT;
@@ -580,7 +529,14 @@ static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags)
 	 *  1) Set timr::it_signal to NULL with timr::it_lock held
 	 *  2) Release timr::it_lock
 	 *  3) Remove from the hash under hash_lock
-	 *  4) Call RCU for removal after the grace period
+	 *  4) Put the reference count.
+	 *
+	 * The reference count might not drop to zero if timr::sigq is
+	 * queued. In that case the signal delivery or flush will put the
+	 * last reference count.
+	 *
+	 * When the reference count reaches zero, the timer is scheduled
+	 * for RCU removal after the grace period.
 	 *
 	 * Holding rcu_read_lock() accross the lookup ensures that
 	 * the timer cannot be freed.
@@ -647,10 +603,10 @@ void common_timer_get(struct k_itimer *timr, struct itimerspec64 *cur_setting)
 	/* interval timer ? */
 	if (iv) {
 		cur_setting->it_interval = ktime_to_timespec64(iv);
-	} else if (!timr->it_active) {
+	} else if (timr->it_status == POSIX_TIMER_DISARMED) {
 		/*
 		 * SIGEV_NONE oneshot timers are never queued and therefore
-		 * timr->it_active is always false. The check below
+		 * timr->it_status is always DISARMED. The check below
 		 * vs. remaining time will handle this case.
 		 *
 		 * For all other timers there is nothing to update here, so
@@ -667,7 +623,7 @@ void common_timer_get(struct k_itimer *timr, struct itimerspec64 *cur_setting)
 	 * is a SIGEV_NONE timer move the expiry time forward by intervals,
 	 * so expiry is > now.
 	 */
-	if (iv && (timr->it_requeue_pending & REQUEUE_PENDING || sig_none))
+	if (iv && timr->it_status != POSIX_TIMER_ARMED)
 		timr->it_overrun += kc->timer_forward(timr, now);
 
 	remaining = kc->timer_remaining(timr, now);
@@ -775,7 +731,7 @@ SYSCALL_DEFINE1(timer_getoverrun, timer_t, timer_id)
 	if (!timr)
 		return -EINVAL;
 
-	overrun = timer_overrun_to_int(timr, 0);
+	overrun = timer_overrun_to_int(timr);
 	unlock_timer(timr, flags);
 
 	return overrun;
@@ -867,8 +823,6 @@ void posix_timer_set_common(struct k_itimer *timer, struct itimerspec64 *new_set
 	else
 		timer->it_interval = 0;
 
-	/* Prevent reloading in case there is a signal pending */
-	timer->it_requeue_pending = (timer->it_requeue_pending + 2) & ~REQUEUE_PENDING;
 	/* Reset overrun accounting */
 	timer->it_overrun_last = 0;
 	timer->it_overrun = -1LL;
@@ -886,8 +840,6 @@ int common_timer_set(struct k_itimer *timr, int flags,
 	if (old_setting)
 		common_timer_get(timr, old_setting);
 
-	/* Prevent rearming by clearing the interval */
-	timr->it_interval = 0;
 	/*
 	 * Careful here. On SMP systems the timer expiry function could be
 	 * active and spinning on timr->it_lock.
@@ -895,7 +847,7 @@ int common_timer_set(struct k_itimer *timr, int flags,
 	if (kc->timer_try_to_cancel(timr) < 0)
 		return TIMER_RETRY;
 
-	timr->it_active = 0;
+	timr->it_status = POSIX_TIMER_DISARMED;
 	posix_timer_set_common(timr, new_setting);
 
 	/* Keep timer disarmed when it_value is zero */
@@ -908,7 +860,8 @@ int common_timer_set(struct k_itimer *timr, int flags,
 	sigev_none = timr->it_sigev_notify == SIGEV_NONE;
 
 	kc->timer_arm(timr, expires, flags & TIMER_ABSTIME, sigev_none);
-	timr->it_active = !sigev_none;
+	if (!sigev_none)
+		timr->it_status = POSIX_TIMER_ARMED;
 	return 0;
 }
 
@@ -936,6 +889,9 @@ retry:
 	if (old_spec64)
 		old_spec64->it_interval = ktime_to_timespec64(timr->it_interval);
 
+	/* Prevent signal delivery and rearming. */
+	timr->it_signal_seq++;
+
 	kc = timr->kclock;
 	if (WARN_ON_ONCE(!kc || !kc->timer_set))
 		error = -EINVAL;
@@ -1004,17 +960,31 @@ int common_timer_del(struct k_itimer *timer)
 {
 	const struct k_clock *kc = timer->kclock;
 
-	timer->it_interval = 0;
 	if (kc->timer_try_to_cancel(timer) < 0)
 		return TIMER_RETRY;
-	timer->it_active = 0;
+	timer->it_status = POSIX_TIMER_DISARMED;
 	return 0;
 }
 
+/*
+ * If the deleted timer is on the ignored list, remove it and
+ * drop the associated reference.
+ */
+static inline void posix_timer_cleanup_ignored(struct k_itimer *tmr)
+{
+	if (!hlist_unhashed(&tmr->ignored_list)) {
+		hlist_del_init(&tmr->ignored_list);
+		posixtimer_putref(tmr);
+	}
+}
+
 static inline int timer_delete_hook(struct k_itimer *timer)
 {
 	const struct k_clock *kc = timer->kclock;
 
+	/* Prevent signal delivery and rearming. */
+	timer->it_signal_seq++;
+
 	if (WARN_ON_ONCE(!kc || !kc->timer_del))
 		return -EINVAL;
 	return kc->timer_del(timer);
@@ -1040,12 +1010,18 @@ retry_delete:
 
 	spin_lock(&current->sighand->siglock);
 	hlist_del(&timer->list);
-	spin_unlock(&current->sighand->siglock);
+	posix_timer_cleanup_ignored(timer);
 	/*
 	 * A concurrent lookup could check timer::it_signal lockless. It
 	 * will reevaluate with timer::it_lock held and observe the NULL.
+	 *
+	 * It must be written with siglock held so that the signal code
+	 * observes timer->it_signal == NULL in do_sigaction(SIG_IGN),
+	 * which prevents it from moving a pending signal of a deleted
+	 * timer to the ignore list.
 	 */
 	WRITE_ONCE(timer->it_signal, NULL);
+	spin_unlock(&current->sighand->siglock);
 
 	unlock_timer(timer, flags);
 	posix_timer_unhash_and_free(timer);
@@ -1091,6 +1067,8 @@ retry_delete:
 	}
 	hlist_del(&timer->list);
 
+	posix_timer_cleanup_ignored(timer);
+
 	/*
 	 * Setting timer::it_signal to NULL is technically not required
 	 * here as nothing can access the timer anymore legitimately via
@@ -1123,6 +1101,19 @@ void exit_itimers(struct task_struct *tsk)
 	/* The timers are not longer accessible via tsk::signal */
 	while (!hlist_empty(&timers))
 		itimer_delete(hlist_entry(timers.first, struct k_itimer, list));
+
+	/*
+	 * There should be no timers on the ignored list. itimer_delete() has
+	 * mopped them up.
+	 */
+	if (!WARN_ON_ONCE(!hlist_empty(&tsk->signal->ignored_posix_timers)))
+		return;
+
+	hlist_move_list(&tsk->signal->ignored_posix_timers, &timers);
+	while (!hlist_empty(&timers)) {
+		posix_timer_cleanup_ignored(hlist_entry(timers.first, struct k_itimer,
+							ignored_list));
+	}
 }
 
 SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
diff --git a/kernel/time/posix-timers.h b/kernel/time/posix-timers.h
index 4784ea65f685..61906f0688c1 100644
--- a/kernel/time/posix-timers.h
+++ b/kernel/time/posix-timers.h
@@ -1,6 +1,12 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 #define TIMER_RETRY 1
 
+enum posix_timer_state {
+	POSIX_TIMER_DISARMED,
+	POSIX_TIMER_ARMED,
+	POSIX_TIMER_REQUEUE_PENDING,
+};
+
 struct k_clock {
 	int	(*clock_getres)(const clockid_t which_clock,
 				struct timespec64 *tp);
@@ -36,7 +42,7 @@ extern const struct k_clock clock_process;
 extern const struct k_clock clock_thread;
 extern const struct k_clock alarm_clock;
 
-int posix_timer_queue_signal(struct k_itimer *timr);
+void posix_timer_queue_signal(struct k_itimer *timr);
 
 void common_timer_get(struct k_itimer *timr, struct itimerspec64 *cur_setting);
 int common_timer_set(struct k_itimer *timr, int flags,
diff --git a/kernel/time/sleep_timeout.c b/kernel/time/sleep_timeout.c
new file mode 100644
index 000000000000..dfe939f6e4ec
--- /dev/null
+++ b/kernel/time/sleep_timeout.c
@@ -0,0 +1,377 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Kernel internal schedule timeout and sleeping functions
+ */
+
+#include <linux/delay.h>
+#include <linux/jiffies.h>
+#include <linux/timer.h>
+#include <linux/sched/signal.h>
+#include <linux/sched/debug.h>
+
+#include "tick-internal.h"
+
+/*
+ * Since schedule_timeout()'s timer is defined on the stack, it must store
+ * the target task on the stack as well.
+ */
+struct process_timer {
+	struct timer_list timer;
+	struct task_struct *task;
+};
+
+static void process_timeout(struct timer_list *t)
+{
+	struct process_timer *timeout = from_timer(timeout, t, timer);
+
+	wake_up_process(timeout->task);
+}
+
+/**
+ * schedule_timeout - sleep until timeout
+ * @timeout: timeout value in jiffies
+ *
+ * Make the current task sleep until @timeout jiffies have elapsed.
+ * The function behavior depends on the current task state
+ * (see also set_current_state() description):
+ *
+ * %TASK_RUNNING - the scheduler is called, but the task does not sleep
+ * at all. That happens because sched_submit_work() does nothing for
+ * tasks in %TASK_RUNNING state.
+ *
+ * %TASK_UNINTERRUPTIBLE - at least @timeout jiffies are guaranteed to
+ * pass before the routine returns unless the current task is explicitly
+ * woken up, (e.g. by wake_up_process()).
+ *
+ * %TASK_INTERRUPTIBLE - the routine may return early if a signal is
+ * delivered to the current task or the current task is explicitly woken
+ * up.
+ *
+ * The current task state is guaranteed to be %TASK_RUNNING when this
+ * routine returns.
+ *
+ * Specifying a @timeout value of %MAX_SCHEDULE_TIMEOUT will schedule
+ * the CPU away without a bound on the timeout. In this case the return
+ * value will be %MAX_SCHEDULE_TIMEOUT.
+ *
+ * Returns: 0 when the timer has expired otherwise the remaining time in
+ * jiffies will be returned. In all cases the return value is guaranteed
+ * to be non-negative.
+ */
+signed long __sched schedule_timeout(signed long timeout)
+{
+	struct process_timer timer;
+	unsigned long expire;
+
+	switch (timeout) {
+	case MAX_SCHEDULE_TIMEOUT:
+		/*
+		 * These two special cases are useful to be comfortable
+		 * in the caller. Nothing more. We could take
+		 * MAX_SCHEDULE_TIMEOUT from one of the negative value
+		 * but I' d like to return a valid offset (>=0) to allow
+		 * the caller to do everything it want with the retval.
+		 */
+		schedule();
+		goto out;
+	default:
+		/*
+		 * Another bit of PARANOID. Note that the retval will be
+		 * 0 since no piece of kernel is supposed to do a check
+		 * for a negative retval of schedule_timeout() (since it
+		 * should never happens anyway). You just have the printk()
+		 * that will tell you if something is gone wrong and where.
+		 */
+		if (timeout < 0) {
+			pr_err("%s: wrong timeout value %lx\n", __func__, timeout);
+			dump_stack();
+			__set_current_state(TASK_RUNNING);
+			goto out;
+		}
+	}
+
+	expire = timeout + jiffies;
+
+	timer.task = current;
+	timer_setup_on_stack(&timer.timer, process_timeout, 0);
+	timer.timer.expires = expire;
+	add_timer(&timer.timer);
+	schedule();
+	del_timer_sync(&timer.timer);
+
+	/* Remove the timer from the object tracker */
+	destroy_timer_on_stack(&timer.timer);
+
+	timeout = expire - jiffies;
+
+ out:
+	return timeout < 0 ? 0 : timeout;
+}
+EXPORT_SYMBOL(schedule_timeout);
+
+/*
+ * __set_current_state() can be used in schedule_timeout_*() functions, because
+ * schedule_timeout() calls schedule() unconditionally.
+ */
+
+/**
+ * schedule_timeout_interruptible - sleep until timeout (interruptible)
+ * @timeout: timeout value in jiffies
+ *
+ * See schedule_timeout() for details.
+ *
+ * Task state is set to TASK_INTERRUPTIBLE before starting the timeout.
+ */
+signed long __sched schedule_timeout_interruptible(signed long timeout)
+{
+	__set_current_state(TASK_INTERRUPTIBLE);
+	return schedule_timeout(timeout);
+}
+EXPORT_SYMBOL(schedule_timeout_interruptible);
+
+/**
+ * schedule_timeout_killable - sleep until timeout (killable)
+ * @timeout: timeout value in jiffies
+ *
+ * See schedule_timeout() for details.
+ *
+ * Task state is set to TASK_KILLABLE before starting the timeout.
+ */
+signed long __sched schedule_timeout_killable(signed long timeout)
+{
+	__set_current_state(TASK_KILLABLE);
+	return schedule_timeout(timeout);
+}
+EXPORT_SYMBOL(schedule_timeout_killable);
+
+/**
+ * schedule_timeout_uninterruptible - sleep until timeout (uninterruptible)
+ * @timeout: timeout value in jiffies
+ *
+ * See schedule_timeout() for details.
+ *
+ * Task state is set to TASK_UNINTERRUPTIBLE before starting the timeout.
+ */
+signed long __sched schedule_timeout_uninterruptible(signed long timeout)
+{
+	__set_current_state(TASK_UNINTERRUPTIBLE);
+	return schedule_timeout(timeout);
+}
+EXPORT_SYMBOL(schedule_timeout_uninterruptible);
+
+/**
+ * schedule_timeout_idle - sleep until timeout (idle)
+ * @timeout: timeout value in jiffies
+ *
+ * See schedule_timeout() for details.
+ *
+ * Task state is set to TASK_IDLE before starting the timeout. It is similar to
+ * schedule_timeout_uninterruptible(), except this task will not contribute to
+ * load average.
+ */
+signed long __sched schedule_timeout_idle(signed long timeout)
+{
+	__set_current_state(TASK_IDLE);
+	return schedule_timeout(timeout);
+}
+EXPORT_SYMBOL(schedule_timeout_idle);
+
+/**
+ * schedule_hrtimeout_range_clock - sleep until timeout
+ * @expires:	timeout value (ktime_t)
+ * @delta:	slack in expires timeout (ktime_t)
+ * @mode:	timer mode
+ * @clock_id:	timer clock to be used
+ *
+ * Details are explained in schedule_hrtimeout_range() function description as
+ * this function is commonly used.
+ */
+int __sched schedule_hrtimeout_range_clock(ktime_t *expires, u64 delta,
+					   const enum hrtimer_mode mode, clockid_t clock_id)
+{
+	struct hrtimer_sleeper t;
+
+	/*
+	 * Optimize when a zero timeout value is given. It does not
+	 * matter whether this is an absolute or a relative time.
+	 */
+	if (expires && *expires == 0) {
+		__set_current_state(TASK_RUNNING);
+		return 0;
+	}
+
+	/*
+	 * A NULL parameter means "infinite"
+	 */
+	if (!expires) {
+		schedule();
+		return -EINTR;
+	}
+
+	hrtimer_setup_sleeper_on_stack(&t, clock_id, mode);
+	hrtimer_set_expires_range_ns(&t.timer, *expires, delta);
+	hrtimer_sleeper_start_expires(&t, mode);
+
+	if (likely(t.task))
+		schedule();
+
+	hrtimer_cancel(&t.timer);
+	destroy_hrtimer_on_stack(&t.timer);
+
+	__set_current_state(TASK_RUNNING);
+
+	return !t.task ? 0 : -EINTR;
+}
+EXPORT_SYMBOL_GPL(schedule_hrtimeout_range_clock);
+
+/**
+ * schedule_hrtimeout_range - sleep until timeout
+ * @expires:	timeout value (ktime_t)
+ * @delta:	slack in expires timeout (ktime_t)
+ * @mode:	timer mode
+ *
+ * Make the current task sleep until the given expiry time has
+ * elapsed. The routine will return immediately unless
+ * the current task state has been set (see set_current_state()).
+ *
+ * The @delta argument gives the kernel the freedom to schedule the
+ * actual wakeup to a time that is both power and performance friendly
+ * for regular (non RT/DL) tasks.
+ * The kernel give the normal best effort behavior for "@expires+@delta",
+ * but may decide to fire the timer earlier, but no earlier than @expires.
+ *
+ * You can set the task state as follows -
+ *
+ * %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to
+ * pass before the routine returns unless the current task is explicitly
+ * woken up, (e.g. by wake_up_process()).
+ *
+ * %TASK_INTERRUPTIBLE - the routine may return early if a signal is
+ * delivered to the current task or the current task is explicitly woken
+ * up.
+ *
+ * The current task state is guaranteed to be TASK_RUNNING when this
+ * routine returns.
+ *
+ * Returns: 0 when the timer has expired. If the task was woken before the
+ * timer expired by a signal (only possible in state TASK_INTERRUPTIBLE) or
+ * by an explicit wakeup, it returns -EINTR.
+ */
+int __sched schedule_hrtimeout_range(ktime_t *expires, u64 delta,
+				     const enum hrtimer_mode mode)
+{
+	return schedule_hrtimeout_range_clock(expires, delta, mode,
+					      CLOCK_MONOTONIC);
+}
+EXPORT_SYMBOL_GPL(schedule_hrtimeout_range);
+
+/**
+ * schedule_hrtimeout - sleep until timeout
+ * @expires:	timeout value (ktime_t)
+ * @mode:	timer mode
+ *
+ * See schedule_hrtimeout_range() for details. @delta argument of
+ * schedule_hrtimeout_range() is set to 0 and has therefore no impact.
+ */
+int __sched schedule_hrtimeout(ktime_t *expires, const enum hrtimer_mode mode)
+{
+	return schedule_hrtimeout_range(expires, 0, mode);
+}
+EXPORT_SYMBOL_GPL(schedule_hrtimeout);
+
+/**
+ * msleep - sleep safely even with waitqueue interruptions
+ * @msecs:	Requested sleep duration in milliseconds
+ *
+ * msleep() uses jiffy based timeouts for the sleep duration. Because of the
+ * design of the timer wheel, the maximum additional percentage delay (slack) is
+ * 12.5%. This is only valid for timers which will end up in level 1 or a higher
+ * level of the timer wheel. For explanation of those 12.5% please check the
+ * detailed description about the basics of the timer wheel.
+ *
+ * The slack of timers which will end up in level 0 depends on sleep duration
+ * (msecs) and HZ configuration and can be calculated in the following way (with
+ * the timer wheel design restriction that the slack is not less than 12.5%):
+ *
+ *   ``slack = MSECS_PER_TICK / msecs``
+ *
+ * When the allowed slack of the callsite is known, the calculation could be
+ * turned around to find the minimal allowed sleep duration to meet the
+ * constraints. For example:
+ *
+ * * ``HZ=1000`` with ``slack=25%``: ``MSECS_PER_TICK / slack = 1 / (1/4) = 4``:
+ *   all sleep durations greater or equal 4ms will meet the constraints.
+ * * ``HZ=1000`` with ``slack=12.5%``: ``MSECS_PER_TICK / slack = 1 / (1/8) = 8``:
+ *   all sleep durations greater or equal 8ms will meet the constraints.
+ * * ``HZ=250`` with ``slack=25%``: ``MSECS_PER_TICK / slack = 4 / (1/4) = 16``:
+ *   all sleep durations greater or equal 16ms will meet the constraints.
+ * * ``HZ=250`` with ``slack=12.5%``: ``MSECS_PER_TICK / slack = 4 / (1/8) = 32``:
+ *   all sleep durations greater or equal 32ms will meet the constraints.
+ *
+ * See also the signal aware variant msleep_interruptible().
+ */
+void msleep(unsigned int msecs)
+{
+	unsigned long timeout = msecs_to_jiffies(msecs);
+
+	while (timeout)
+		timeout = schedule_timeout_uninterruptible(timeout);
+}
+EXPORT_SYMBOL(msleep);
+
+/**
+ * msleep_interruptible - sleep waiting for signals
+ * @msecs:	Requested sleep duration in milliseconds
+ *
+ * See msleep() for some basic information.
+ *
+ * The difference between msleep() and msleep_interruptible() is that the sleep
+ * could be interrupted by a signal delivery and then returns early.
+ *
+ * Returns: The remaining time of the sleep duration transformed to msecs (see
+ * schedule_timeout() for details).
+ */
+unsigned long msleep_interruptible(unsigned int msecs)
+{
+	unsigned long timeout = msecs_to_jiffies(msecs);
+
+	while (timeout && !signal_pending(current))
+		timeout = schedule_timeout_interruptible(timeout);
+	return jiffies_to_msecs(timeout);
+}
+EXPORT_SYMBOL(msleep_interruptible);
+
+/**
+ * usleep_range_state - Sleep for an approximate time in a given state
+ * @min:	Minimum time in usecs to sleep
+ * @max:	Maximum time in usecs to sleep
+ * @state:	State of the current task that will be while sleeping
+ *
+ * usleep_range_state() sleeps at least for the minimum specified time but not
+ * longer than the maximum specified amount of time. The range might reduce
+ * power usage by allowing hrtimers to coalesce an already scheduled interrupt
+ * with this hrtimer. In the worst case, an interrupt is scheduled for the upper
+ * bound.
+ *
+ * The sleeping task is set to the specified state before starting the sleep.
+ *
+ * In non-atomic context where the exact wakeup time is flexible, use
+ * usleep_range() or its variants instead of udelay(). The sleep improves
+ * responsiveness by avoiding the CPU-hogging busy-wait of udelay().
+ */
+void __sched usleep_range_state(unsigned long min, unsigned long max, unsigned int state)
+{
+	ktime_t exp = ktime_add_us(ktime_get(), min);
+	u64 delta = (u64)(max - min) * NSEC_PER_USEC;
+
+	if (WARN_ON_ONCE(max < min))
+		delta = 0;
+
+	for (;;) {
+		__set_current_state(state);
+		/* Do not return before the requested sleep time has elapsed */
+		if (!schedule_hrtimeout_range(&exp, delta, HRTIMER_MODE_ABS))
+			break;
+	}
+}
+EXPORT_SYMBOL(usleep_range_state);
diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h
index 5f2105e637bd..faac36de35b9 100644
--- a/kernel/time/tick-internal.h
+++ b/kernel/time/tick-internal.h
@@ -25,6 +25,7 @@ extern int tick_do_timer_cpu __read_mostly;
 extern void tick_setup_periodic(struct clock_event_device *dev, int broadcast);
 extern void tick_handle_periodic(struct clock_event_device *dev);
 extern void tick_check_new_device(struct clock_event_device *dev);
+extern void tick_offline_cpu(unsigned int cpu);
 extern void tick_shutdown(unsigned int cpu);
 extern void tick_suspend(void);
 extern void tick_resume(void);
@@ -142,10 +143,8 @@ static inline bool tick_broadcast_oneshot_available(void) { return tick_oneshot_
 #endif /* !(BROADCAST && ONESHOT) */
 
 #if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_HOTPLUG_CPU)
-extern void tick_offline_cpu(unsigned int cpu);
 extern void tick_broadcast_offline(unsigned int cpu);
 #else
-static inline void tick_offline_cpu(unsigned int cpu) { }
 static inline void tick_broadcast_offline(unsigned int cpu) { }
 #endif
 
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index e0c47259e91a..fa058510af9c 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -311,14 +311,6 @@ static enum hrtimer_restart tick_nohz_handler(struct hrtimer *timer)
 	return HRTIMER_RESTART;
 }
 
-static void tick_sched_timer_cancel(struct tick_sched *ts)
-{
-	if (tick_sched_flag_test(ts, TS_FLAG_HIGHRES))
-		hrtimer_cancel(&ts->sched_timer);
-	else if (tick_sched_flag_test(ts, TS_FLAG_NOHZ))
-		tick_program_event(KTIME_MAX, 1);
-}
-
 #ifdef CONFIG_NO_HZ_FULL
 cpumask_var_t tick_nohz_full_mask;
 EXPORT_SYMBOL_GPL(tick_nohz_full_mask);
@@ -1061,7 +1053,10 @@ static void tick_nohz_stop_tick(struct tick_sched *ts, int cpu)
 	 * the tick timer.
 	 */
 	if (unlikely(expires == KTIME_MAX)) {
-		tick_sched_timer_cancel(ts);
+		if (tick_sched_flag_test(ts, TS_FLAG_HIGHRES))
+			hrtimer_cancel(&ts->sched_timer);
+		else
+			tick_program_event(KTIME_MAX, 1);
 		return;
 	}
 
@@ -1610,21 +1605,13 @@ void tick_setup_sched_timer(bool hrtimer)
  */
 void tick_sched_timer_dying(int cpu)
 {
-	struct tick_device *td = &per_cpu(tick_cpu_device, cpu);
 	struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
-	struct clock_event_device *dev = td->evtdev;
 	ktime_t idle_sleeptime, iowait_sleeptime;
 	unsigned long idle_calls, idle_sleeps;
 
 	/* This must happen before hrtimers are migrated! */
-	tick_sched_timer_cancel(ts);
-
-	/*
-	 * If the clockevents doesn't support CLOCK_EVT_STATE_ONESHOT_STOPPED,
-	 * make sure not to call low-res tick handler.
-	 */
-	if (tick_sched_flag_test(ts, TS_FLAG_NOHZ))
-		dev->event_handler = clockevents_handle_noop;
+	if (tick_sched_flag_test(ts, TS_FLAG_HIGHRES))
+		hrtimer_cancel(&ts->sched_timer);
 
 	idle_sleeptime = ts->idle_sleeptime;
 	iowait_sleeptime = ts->iowait_sleeptime;
diff --git a/kernel/time/time.c b/kernel/time/time.c
index 642647f5046b..1b69caa87480 100644
--- a/kernel/time/time.c
+++ b/kernel/time/time.c
@@ -556,9 +556,9 @@ EXPORT_SYMBOL(ns_to_timespec64);
  * - all other values are converted to jiffies by either multiplying
  *   the input value by a factor or dividing it with a factor and
  *   handling any 32-bit overflows.
- *   for the details see __msecs_to_jiffies()
+ *   for the details see _msecs_to_jiffies()
  *
- * __msecs_to_jiffies() checks for the passed in value being a constant
+ * msecs_to_jiffies() checks for the passed in value being a constant
  * via __builtin_constant_p() allowing gcc to eliminate most of the
  * code, __msecs_to_jiffies() is called if the value passed does not
  * allow constant folding and the actual conversion must be done at
@@ -866,7 +866,7 @@ struct timespec64 timespec64_add_safe(const struct timespec64 lhs,
  *
  * Handles compat or 32-bit modes.
  *
- * Return: %0 on success or negative errno on error
+ * Return: 0 on success or negative errno on error
  */
 int get_timespec64(struct timespec64 *ts,
 		   const struct __kernel_timespec __user *uts)
@@ -897,7 +897,7 @@ EXPORT_SYMBOL_GPL(get_timespec64);
  * @ts: input &struct timespec64
  * @uts: user's &struct __kernel_timespec
  *
- * Return: %0 on success or negative errno on error
+ * Return: 0 on success or negative errno on error
  */
 int put_timespec64(const struct timespec64 *ts,
 		   struct __kernel_timespec __user *uts)
@@ -944,7 +944,7 @@ static int __put_old_timespec32(const struct timespec64 *ts64,
  *
  * Handles X86_X32_ABI compatibility conversion.
  *
- * Return: %0 on success or negative errno on error
+ * Return: 0 on success or negative errno on error
  */
 int get_old_timespec32(struct timespec64 *ts, const void __user *uts)
 {
@@ -963,7 +963,7 @@ EXPORT_SYMBOL_GPL(get_old_timespec32);
  *
  * Handles X86_X32_ABI compatibility conversion.
  *
- * Return: %0 on success or negative errno on error
+ * Return: 0 on success or negative errno on error
  */
 int put_old_timespec32(const struct timespec64 *ts, void __user *uts)
 {
@@ -979,7 +979,7 @@ EXPORT_SYMBOL_GPL(put_old_timespec32);
  * @it: destination &struct itimerspec64
  * @uit: user's &struct __kernel_itimerspec
  *
- * Return: %0 on success or negative errno on error
+ * Return: 0 on success or negative errno on error
  */
 int get_itimerspec64(struct itimerspec64 *it,
 			const struct __kernel_itimerspec __user *uit)
@@ -1002,7 +1002,7 @@ EXPORT_SYMBOL_GPL(get_itimerspec64);
  * @it: input &struct itimerspec64
  * @uit: user's &struct __kernel_itimerspec
  *
- * Return: %0 on success or negative errno on error
+ * Return: 0 on success or negative errno on error
  */
 int put_itimerspec64(const struct itimerspec64 *it,
 			struct __kernel_itimerspec __user *uit)
@@ -1024,7 +1024,7 @@ EXPORT_SYMBOL_GPL(put_itimerspec64);
  * @its: destination &struct itimerspec64
  * @uits: user's &struct old_itimerspec32
  *
- * Return: %0 on success or negative errno on error
+ * Return: 0 on success or negative errno on error
  */
 int get_old_itimerspec32(struct itimerspec64 *its,
 			const struct old_itimerspec32 __user *uits)
@@ -1043,7 +1043,7 @@ EXPORT_SYMBOL_GPL(get_old_itimerspec32);
  * @its: input &struct itimerspec64
  * @uits: user's &struct old_itimerspec32
  *
- * Return: %0 on success or negative errno on error
+ * Return: 0 on success or negative errno on error
  */
 int put_old_itimerspec32(const struct itimerspec64 *its,
 			struct old_itimerspec32 __user *uits)
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index cdd61990cd14..0ca85ff4fbb4 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -30,8 +30,9 @@
 #include "timekeeping_internal.h"
 
 #define TK_CLEAR_NTP		(1 << 0)
-#define TK_MIRROR		(1 << 1)
-#define TK_CLOCK_WAS_SET	(1 << 2)
+#define TK_CLOCK_WAS_SET	(1 << 1)
+
+#define TK_UPDATE_ALL		(TK_CLEAR_NTP | TK_CLOCK_WAS_SET)
 
 enum timekeeping_adv_mode {
 	/* Update timekeeper when a tick has passed */
@@ -41,20 +42,18 @@ enum timekeeping_adv_mode {
 	TK_ADV_FREQ
 };
 
-DEFINE_RAW_SPINLOCK(timekeeper_lock);
-
 /*
  * The most important data for readout fits into a single 64 byte
  * cache line.
  */
-static struct {
+struct tk_data {
 	seqcount_raw_spinlock_t	seq;
 	struct timekeeper	timekeeper;
-} tk_core ____cacheline_aligned = {
-	.seq = SEQCNT_RAW_SPINLOCK_ZERO(tk_core.seq, &timekeeper_lock),
-};
+	struct timekeeper	shadow_timekeeper;
+	raw_spinlock_t		lock;
+} ____cacheline_aligned;
 
-static struct timekeeper shadow_timekeeper;
+static struct tk_data tk_core;
 
 /* flag for if timekeeping is suspended */
 int __read_mostly timekeeping_suspended;
@@ -114,6 +113,19 @@ static struct tk_fast tk_fast_raw  ____cacheline_aligned = {
 	.base[1] = FAST_TK_INIT,
 };
 
+unsigned long timekeeper_lock_irqsave(void)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&tk_core.lock, flags);
+	return flags;
+}
+
+void timekeeper_unlock_irqrestore(unsigned long flags)
+{
+	raw_spin_unlock_irqrestore(&tk_core.lock, flags);
+}
+
 /*
  * Multigrain timestamps require tracking the latest fine-grained timestamp
  * that has been issued, and never returning a coarse-grained timestamp that is
@@ -178,13 +190,15 @@ static void tk_set_wall_to_mono(struct timekeeper *tk, struct timespec64 wtm)
 	WARN_ON_ONCE(tk->offs_real != timespec64_to_ktime(tmp));
 	tk->wall_to_monotonic = wtm;
 	set_normalized_timespec64(&tmp, -wtm.tv_sec, -wtm.tv_nsec);
-	tk->offs_real = timespec64_to_ktime(tmp);
-	tk->offs_tai = ktime_add(tk->offs_real, ktime_set(tk->tai_offset, 0));
+	/* Paired with READ_ONCE() in ktime_mono_to_any() */
+	WRITE_ONCE(tk->offs_real, timespec64_to_ktime(tmp));
+	WRITE_ONCE(tk->offs_tai, ktime_add(tk->offs_real, ktime_set(tk->tai_offset, 0)));
 }
 
 static inline void tk_update_sleep_time(struct timekeeper *tk, ktime_t delta)
 {
-	tk->offs_boot = ktime_add(tk->offs_boot, delta);
+	/* Paired with READ_ONCE() in ktime_mono_to_any() */
+	WRITE_ONCE(tk->offs_boot, ktime_add(tk->offs_boot, delta));
 	/*
 	 * Timespec representation for VDSO update to avoid 64bit division
 	 * on every update.
@@ -201,7 +215,7 @@ static inline void tk_update_sleep_time(struct timekeeper *tk, ktime_t delta)
  * the tkr's clocksource may change between the read reference, and the
  * clock reference passed to the read function.  This can cause crashes if
  * the wrong clocksource is passed to the wrong read function.
- * This isn't necessary to use when holding the timekeeper_lock or doing
+ * This isn't necessary to use when holding the tk_core.lock or doing
  * a read of the fast-timekeeper tkrs (which is protected by its own locking
  * and update logic).
  */
@@ -212,97 +226,6 @@ static inline u64 tk_clock_read(const struct tk_read_base *tkr)
 	return clock->read(clock);
 }
 
-#ifdef CONFIG_DEBUG_TIMEKEEPING
-#define WARNING_FREQ (HZ*300) /* 5 minute rate-limiting */
-
-static void timekeeping_check_update(struct timekeeper *tk, u64 offset)
-{
-
-	u64 max_cycles = tk->tkr_mono.clock->max_cycles;
-	const char *name = tk->tkr_mono.clock->name;
-
-	if (offset > max_cycles) {
-		printk_deferred("WARNING: timekeeping: Cycle offset (%lld) is larger than allowed by the '%s' clock's max_cycles value (%lld): time overflow danger\n",
-				offset, name, max_cycles);
-		printk_deferred("         timekeeping: Your kernel is sick, but tries to cope by capping time updates\n");
-	} else {
-		if (offset > (max_cycles >> 1)) {
-			printk_deferred("INFO: timekeeping: Cycle offset (%lld) is larger than the '%s' clock's 50%% safety margin (%lld)\n",
-					offset, name, max_cycles >> 1);
-			printk_deferred("      timekeeping: Your kernel is still fine, but is feeling a bit nervous\n");
-		}
-	}
-
-	if (tk->underflow_seen) {
-		if (jiffies - tk->last_warning > WARNING_FREQ) {
-			printk_deferred("WARNING: Underflow in clocksource '%s' observed, time update ignored.\n", name);
-			printk_deferred("         Please report this, consider using a different clocksource, if possible.\n");
-			printk_deferred("         Your kernel is probably still fine.\n");
-			tk->last_warning = jiffies;
-		}
-		tk->underflow_seen = 0;
-	}
-
-	if (tk->overflow_seen) {
-		if (jiffies - tk->last_warning > WARNING_FREQ) {
-			printk_deferred("WARNING: Overflow in clocksource '%s' observed, time update capped.\n", name);
-			printk_deferred("         Please report this, consider using a different clocksource, if possible.\n");
-			printk_deferred("         Your kernel is probably still fine.\n");
-			tk->last_warning = jiffies;
-		}
-		tk->overflow_seen = 0;
-	}
-}
-
-static inline u64 timekeeping_cycles_to_ns(const struct tk_read_base *tkr, u64 cycles);
-
-static inline u64 timekeeping_debug_get_ns(const struct tk_read_base *tkr)
-{
-	struct timekeeper *tk = &tk_core.timekeeper;
-	u64 now, last, mask, max, delta;
-	unsigned int seq;
-
-	/*
-	 * Since we're called holding a seqcount, the data may shift
-	 * under us while we're doing the calculation. This can cause
-	 * false positives, since we'd note a problem but throw the
-	 * results away. So nest another seqcount here to atomically
-	 * grab the points we are checking with.
-	 */
-	do {
-		seq = read_seqcount_begin(&tk_core.seq);
-		now = tk_clock_read(tkr);
-		last = tkr->cycle_last;
-		mask = tkr->mask;
-		max = tkr->clock->max_cycles;
-	} while (read_seqcount_retry(&tk_core.seq, seq));
-
-	delta = clocksource_delta(now, last, mask);
-
-	/*
-	 * Try to catch underflows by checking if we are seeing small
-	 * mask-relative negative values.
-	 */
-	if (unlikely((~delta & mask) < (mask >> 3)))
-		tk->underflow_seen = 1;
-
-	/* Check for multiplication overflows */
-	if (unlikely(delta > max))
-		tk->overflow_seen = 1;
-
-	/* timekeeping_cycles_to_ns() handles both under and overflow */
-	return timekeeping_cycles_to_ns(tkr, now);
-}
-#else
-static inline void timekeeping_check_update(struct timekeeper *tk, u64 offset)
-{
-}
-static inline u64 timekeeping_debug_get_ns(const struct tk_read_base *tkr)
-{
-	BUG();
-}
-#endif
-
 /**
  * tk_setup_internals - Set up internals to use clocksource clock.
  *
@@ -407,19 +330,11 @@ static inline u64 timekeeping_cycles_to_ns(const struct tk_read_base *tkr, u64 c
 	return ((delta * tkr->mult) + tkr->xtime_nsec) >> tkr->shift;
 }
 
-static __always_inline u64 __timekeeping_get_ns(const struct tk_read_base *tkr)
+static __always_inline u64 timekeeping_get_ns(const struct tk_read_base *tkr)
 {
 	return timekeeping_cycles_to_ns(tkr, tk_clock_read(tkr));
 }
 
-static inline u64 timekeeping_get_ns(const struct tk_read_base *tkr)
-{
-	if (IS_ENABLED(CONFIG_DEBUG_TIMEKEEPING))
-		return timekeeping_debug_get_ns(tkr);
-
-	return __timekeeping_get_ns(tkr);
-}
-
 /**
  * update_fast_timekeeper - Update the fast and NMI safe monotonic timekeeper.
  * @tkr: Timekeeping readout base from which we take the update
@@ -465,7 +380,7 @@ static __always_inline u64 __ktime_get_fast_ns(struct tk_fast *tkf)
 		seq = read_seqcount_latch(&tkf->seq);
 		tkr = tkf->base + (seq & 0x01);
 		now = ktime_to_ns(tkr->base);
-		now += __timekeeping_get_ns(tkr);
+		now += timekeeping_get_ns(tkr);
 	} while (read_seqcount_latch_retry(&tkf->seq, seq));
 
 	return now;
@@ -536,7 +451,7 @@ EXPORT_SYMBOL_GPL(ktime_get_raw_fast_ns);
  *    timekeeping_inject_sleeptime64()
  *    __timekeeping_inject_sleeptime(tk, delta);
  *                                                 timestamp();
- *    timekeeping_update(tk, TK_CLEAR_NTP...);
+ *    timekeeping_update_staged(tkd, TK_CLEAR_NTP...);
  *
  * (2) On 32-bit systems, the 64-bit boot offset (tk->offs_boot) may be
  * partially updated.  Since the tk->offs_boot update is a rare event, this
@@ -581,7 +496,7 @@ static __always_inline u64 __ktime_get_real_fast(struct tk_fast *tkf, u64 *mono)
 		tkr = tkf->base + (seq & 0x01);
 		basem = ktime_to_ns(tkr->base);
 		baser = ktime_to_ns(tkr->base_real);
-		delta = __timekeeping_get_ns(tkr);
+		delta = timekeeping_get_ns(tkr);
 	} while (raw_read_seqcount_latch_retry(&tkf->seq, seq));
 
 	if (mono)
@@ -695,13 +610,11 @@ static void update_pvclock_gtod(struct timekeeper *tk, bool was_set)
 int pvclock_gtod_register_notifier(struct notifier_block *nb)
 {
 	struct timekeeper *tk = &tk_core.timekeeper;
-	unsigned long flags;
 	int ret;
 
-	raw_spin_lock_irqsave(&timekeeper_lock, flags);
+	guard(raw_spinlock_irqsave)(&tk_core.lock);
 	ret = raw_notifier_chain_register(&pvclock_gtod_chain, nb);
 	update_pvclock_gtod(tk, true);
-	raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
 
 	return ret;
 }
@@ -714,14 +627,8 @@ EXPORT_SYMBOL_GPL(pvclock_gtod_register_notifier);
  */
 int pvclock_gtod_unregister_notifier(struct notifier_block *nb)
 {
-	unsigned long flags;
-	int ret;
-
-	raw_spin_lock_irqsave(&timekeeper_lock, flags);
-	ret = raw_notifier_chain_unregister(&pvclock_gtod_chain, nb);
-	raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
-
-	return ret;
+	guard(raw_spinlock_irqsave)(&tk_core.lock);
+	return raw_notifier_chain_unregister(&pvclock_gtod_chain, nb);
 }
 EXPORT_SYMBOL_GPL(pvclock_gtod_unregister_notifier);
 
@@ -737,6 +644,18 @@ static inline void tk_update_leap_state(struct timekeeper *tk)
 }
 
 /*
+ * Leap state update for both shadow and the real timekeeper
+ * Separate to spare a full memcpy() of the timekeeper.
+ */
+static void tk_update_leap_state_all(struct tk_data *tkd)
+{
+	write_seqcount_begin(&tkd->seq);
+	tk_update_leap_state(&tkd->shadow_timekeeper);
+	tkd->timekeeper.next_leap_ktime = tkd->shadow_timekeeper.next_leap_ktime;
+	write_seqcount_end(&tkd->seq);
+}
+
+/*
  * Update the ktime_t based scalar nsec members of the timekeeper
  */
 static inline void tk_update_ktime_data(struct timekeeper *tk)
@@ -769,9 +688,30 @@ static inline void tk_update_ktime_data(struct timekeeper *tk)
 	tk->tkr_raw.base = ns_to_ktime(tk->raw_sec * NSEC_PER_SEC);
 }
 
-/* must hold timekeeper_lock */
-static void timekeeping_update(struct timekeeper *tk, unsigned int action)
+/*
+ * Restore the shadow timekeeper from the real timekeeper.
+ */
+static void timekeeping_restore_shadow(struct tk_data *tkd)
+{
+	lockdep_assert_held(&tkd->lock);
+	memcpy(&tkd->shadow_timekeeper, &tkd->timekeeper, sizeof(tkd->timekeeper));
+}
+
+static void timekeeping_update_from_shadow(struct tk_data *tkd, unsigned int action)
 {
+	struct timekeeper *tk = &tk_core.shadow_timekeeper;
+
+	lockdep_assert_held(&tkd->lock);
+
+	/*
+	 * Block out readers before running the updates below because that
+	 * updates VDSO and other time related infrastructure. Not blocking
+	 * the readers might let a reader see time going backwards when
+	 * reading from the VDSO after the VDSO update and then reading in
+	 * the kernel from the timekeeper before that got updated.
+	 */
+	write_seqcount_begin(&tkd->seq);
+
 	if (action & TK_CLEAR_NTP) {
 		tk->ntp_error = 0;
 		ntp_clear();
@@ -789,14 +729,17 @@ static void timekeeping_update(struct timekeeper *tk, unsigned int action)
 
 	if (action & TK_CLOCK_WAS_SET)
 		tk->clock_was_set_seq++;
+
 	/*
-	 * The mirroring of the data to the shadow-timekeeper needs
-	 * to happen last here to ensure we don't over-write the
-	 * timekeeper structure on the next update with stale data
+	 * Update the real timekeeper.
+	 *
+	 * We could avoid this memcpy() by switching pointers, but that has
+	 * the downside that the reader side does not longer benefit from
+	 * the cacheline optimized data layout of the timekeeper and requires
+	 * another indirection.
 	 */
-	if (action & TK_MIRROR)
-		memcpy(&shadow_timekeeper, &tk_core.timekeeper,
-		       sizeof(tk_core.timekeeper));
+	memcpy(&tkd->timekeeper, tk, sizeof(*tk));
+	write_seqcount_end(&tkd->seq);
 }
 
 /**
@@ -949,6 +892,14 @@ ktime_t ktime_mono_to_any(ktime_t tmono, enum tk_offsets offs)
 	unsigned int seq;
 	ktime_t tconv;
 
+	if (IS_ENABLED(CONFIG_64BIT)) {
+		/*
+		 * Paired with WRITE_ONCE()s in tk_set_wall_to_mono() and
+		 * tk_update_sleep_time().
+		 */
+		return ktime_add(tmono, READ_ONCE(*offset));
+	}
+
 	do {
 		seq = read_seqcount_begin(&tk_core.seq);
 		tconv = ktime_add(tmono, *offset);
@@ -1079,6 +1030,7 @@ void ktime_get_snapshot(struct system_time_snapshot *systime_snapshot)
 	unsigned int seq;
 	ktime_t base_raw;
 	ktime_t base_real;
+	ktime_t base_boot;
 	u64 nsec_raw;
 	u64 nsec_real;
 	u64 now;
@@ -1093,6 +1045,8 @@ void ktime_get_snapshot(struct system_time_snapshot *systime_snapshot)
 		systime_snapshot->clock_was_set_seq = tk->clock_was_set_seq;
 		base_real = ktime_add(tk->tkr_mono.base,
 				      tk_core.timekeeper.offs_real);
+		base_boot = ktime_add(tk->tkr_mono.base,
+				      tk_core.timekeeper.offs_boot);
 		base_raw = tk->tkr_raw.base;
 		nsec_real = timekeeping_cycles_to_ns(&tk->tkr_mono, now);
 		nsec_raw  = timekeeping_cycles_to_ns(&tk->tkr_raw, now);
@@ -1100,6 +1054,7 @@ void ktime_get_snapshot(struct system_time_snapshot *systime_snapshot)
 
 	systime_snapshot->cycles = now;
 	systime_snapshot->real = ktime_add_ns(base_real, nsec_real);
+	systime_snapshot->boot = ktime_add_ns(base_boot, nsec_real);
 	systime_snapshot->raw = ktime_add_ns(base_raw, nsec_raw);
 }
 EXPORT_SYMBOL_GPL(ktime_get_snapshot);
@@ -1459,45 +1414,35 @@ EXPORT_SYMBOL_GPL(timekeeping_clocksource_has_base);
  */
 int do_settimeofday64(const struct timespec64 *ts)
 {
-	struct timekeeper *tk = &tk_core.timekeeper;
 	struct timespec64 ts_delta, xt;
-	unsigned long flags;
-	int ret = 0;
 
 	if (!timespec64_valid_settod(ts))
 		return -EINVAL;
 
-	raw_spin_lock_irqsave(&timekeeper_lock, flags);
-	write_seqcount_begin(&tk_core.seq);
-
-	timekeeping_forward_now(tk);
+	scoped_guard (raw_spinlock_irqsave, &tk_core.lock) {
+		struct timekeeper *tks = &tk_core.shadow_timekeeper;
 
-	xt = tk_xtime(tk);
-	ts_delta = timespec64_sub(*ts, xt);
+		timekeeping_forward_now(tks);
 
-	if (timespec64_compare(&tk->wall_to_monotonic, &ts_delta) > 0) {
-		ret = -EINVAL;
-		goto out;
-	}
-
-	tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, ts_delta));
+		xt = tk_xtime(tks);
+		ts_delta = timespec64_sub(*ts, xt);
 
-	tk_set_xtime(tk, ts);
-out:
-	timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET);
+		if (timespec64_compare(&tks->wall_to_monotonic, &ts_delta) > 0) {
+			timekeeping_restore_shadow(&tk_core);
+			return -EINVAL;
+		}
 
-	write_seqcount_end(&tk_core.seq);
-	raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
+		tk_set_wall_to_mono(tks, timespec64_sub(tks->wall_to_monotonic, ts_delta));
+		tk_set_xtime(tks, ts);
+		timekeeping_update_from_shadow(&tk_core, TK_UPDATE_ALL);
+	}
 
 	/* Signal hrtimers about time change */
 	clock_was_set(CLOCK_SET_WALL);
 
-	if (!ret) {
-		audit_tk_injoffset(ts_delta);
-		add_device_randomness(ts, sizeof(*ts));
-	}
-
-	return ret;
+	audit_tk_injoffset(ts_delta);
+	add_device_randomness(ts, sizeof(*ts));
+	return 0;
 }
 EXPORT_SYMBOL(do_settimeofday64);
 
@@ -1509,40 +1454,31 @@ EXPORT_SYMBOL(do_settimeofday64);
  */
 static int timekeeping_inject_offset(const struct timespec64 *ts)
 {
-	struct timekeeper *tk = &tk_core.timekeeper;
-	unsigned long flags;
-	struct timespec64 tmp;
-	int ret = 0;
-
 	if (ts->tv_nsec < 0 || ts->tv_nsec >= NSEC_PER_SEC)
 		return -EINVAL;
 
-	raw_spin_lock_irqsave(&timekeeper_lock, flags);
-	write_seqcount_begin(&tk_core.seq);
-
-	timekeeping_forward_now(tk);
-
-	/* Make sure the proposed value is valid */
-	tmp = timespec64_add(tk_xtime(tk), *ts);
-	if (timespec64_compare(&tk->wall_to_monotonic, ts) > 0 ||
-	    !timespec64_valid_settod(&tmp)) {
-		ret = -EINVAL;
-		goto error;
-	}
+	scoped_guard (raw_spinlock_irqsave, &tk_core.lock) {
+		struct timekeeper *tks = &tk_core.shadow_timekeeper;
+		struct timespec64 tmp;
 
-	tk_xtime_add(tk, ts);
-	tk_set_wall_to_mono(tk, timespec64_sub(tk->wall_to_monotonic, *ts));
+		timekeeping_forward_now(tks);
 
-error: /* even if we error out, we forwarded the time, so call update */
-	timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET);
+		/* Make sure the proposed value is valid */
+		tmp = timespec64_add(tk_xtime(tks), *ts);
+		if (timespec64_compare(&tks->wall_to_monotonic, ts) > 0 ||
+		    !timespec64_valid_settod(&tmp)) {
+			timekeeping_restore_shadow(&tk_core);
+			return -EINVAL;
+		}
 
-	write_seqcount_end(&tk_core.seq);
-	raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
+		tk_xtime_add(tks, ts);
+		tk_set_wall_to_mono(tks, timespec64_sub(tks->wall_to_monotonic, *ts));
+		timekeeping_update_from_shadow(&tk_core, TK_UPDATE_ALL);
+	}
 
 	/* Signal hrtimers about time change */
 	clock_was_set(CLOCK_SET_WALL);
-
-	return ret;
+	return 0;
 }
 
 /*
@@ -1595,43 +1531,34 @@ static void __timekeeping_set_tai_offset(struct timekeeper *tk, s32 tai_offset)
  */
 static int change_clocksource(void *data)
 {
-	struct timekeeper *tk = &tk_core.timekeeper;
-	struct clocksource *new, *old = NULL;
-	unsigned long flags;
-	bool change = false;
-
-	new = (struct clocksource *) data;
+	struct clocksource *new = data, *old = NULL;
 
 	/*
-	 * If the cs is in module, get a module reference. Succeeds
-	 * for built-in code (owner == NULL) as well.
+	 * If the clocksource is in a module, get a module reference.
+	 * Succeeds for built-in code (owner == NULL) as well. Abort if the
+	 * reference can't be acquired.
 	 */
-	if (try_module_get(new->owner)) {
-		if (!new->enable || new->enable(new) == 0)
-			change = true;
-		else
-			module_put(new->owner);
-	}
-
-	raw_spin_lock_irqsave(&timekeeper_lock, flags);
-	write_seqcount_begin(&tk_core.seq);
-
-	timekeeping_forward_now(tk);
+	if (!try_module_get(new->owner))
+		return 0;
 
-	if (change) {
-		old = tk->tkr_mono.clock;
-		tk_setup_internals(tk, new);
+	/* Abort if the device can't be enabled */
+	if (new->enable && new->enable(new) != 0) {
+		module_put(new->owner);
+		return 0;
 	}
 
-	timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET);
+	scoped_guard (raw_spinlock_irqsave, &tk_core.lock) {
+		struct timekeeper *tks = &tk_core.shadow_timekeeper;
 
-	write_seqcount_end(&tk_core.seq);
-	raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
+		timekeeping_forward_now(tks);
+		old = tks->tkr_mono.clock;
+		tk_setup_internals(tks, new);
+		timekeeping_update_from_shadow(&tk_core, TK_UPDATE_ALL);
+	}
 
 	if (old) {
 		if (old->disable)
 			old->disable(old);
-
 		module_put(old->owner);
 	}
 
@@ -1756,6 +1683,12 @@ read_persistent_wall_and_boot_offset(struct timespec64 *wall_time,
 	*boot_offset = ns_to_timespec64(local_clock());
 }
 
+static __init void tkd_basic_setup(struct tk_data *tkd)
+{
+	raw_spin_lock_init(&tkd->lock);
+	seqcount_raw_spinlock_init(&tkd->seq, &tkd->lock);
+}
+
 /*
  * Flag reflecting whether timekeeping_resume() has injected sleeptime.
  *
@@ -1780,9 +1713,10 @@ static bool persistent_clock_exists;
 void __init timekeeping_init(void)
 {
 	struct timespec64 wall_time, boot_offset, wall_to_mono;
-	struct timekeeper *tk = &tk_core.timekeeper;
+	struct timekeeper *tks = &tk_core.shadow_timekeeper;
 	struct clocksource *clock;
-	unsigned long flags;
+
+	tkd_basic_setup(&tk_core);
 
 	read_persistent_wall_and_boot_offset(&wall_time, &boot_offset);
 	if (timespec64_valid_settod(&wall_time) &&
@@ -1802,24 +1736,21 @@ void __init timekeeping_init(void)
 	 */
 	wall_to_mono = timespec64_sub(boot_offset, wall_time);
 
-	raw_spin_lock_irqsave(&timekeeper_lock, flags);
-	write_seqcount_begin(&tk_core.seq);
+	guard(raw_spinlock_irqsave)(&tk_core.lock);
+
 	ntp_init();
 
 	clock = clocksource_default_clock();
 	if (clock->enable)
 		clock->enable(clock);
-	tk_setup_internals(tk, clock);
-
-	tk_set_xtime(tk, &wall_time);
-	tk->raw_sec = 0;
+	tk_setup_internals(tks, clock);
 
-	tk_set_wall_to_mono(tk, wall_to_mono);
+	tk_set_xtime(tks, &wall_time);
+	tks->raw_sec = 0;
 
-	timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET);
+	tk_set_wall_to_mono(tks, wall_to_mono);
 
-	write_seqcount_end(&tk_core.seq);
-	raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
+	timekeeping_update_from_shadow(&tk_core, TK_CLOCK_WAS_SET);
 }
 
 /* time in seconds when suspend began for persistent clock */
@@ -1897,22 +1828,14 @@ bool timekeeping_rtc_skipsuspend(void)
  */
 void timekeeping_inject_sleeptime64(const struct timespec64 *delta)
 {
-	struct timekeeper *tk = &tk_core.timekeeper;
-	unsigned long flags;
+	scoped_guard(raw_spinlock_irqsave, &tk_core.lock) {
+		struct timekeeper *tks = &tk_core.shadow_timekeeper;
 
-	raw_spin_lock_irqsave(&timekeeper_lock, flags);
-	write_seqcount_begin(&tk_core.seq);
-
-	suspend_timing_needed = false;
-
-	timekeeping_forward_now(tk);
-
-	__timekeeping_inject_sleeptime(tk, delta);
-
-	timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET);
-
-	write_seqcount_end(&tk_core.seq);
-	raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
+		suspend_timing_needed = false;
+		timekeeping_forward_now(tks);
+		__timekeeping_inject_sleeptime(tks, delta);
+		timekeeping_update_from_shadow(&tk_core, TK_UPDATE_ALL);
+	}
 
 	/* Signal hrtimers about time change */
 	clock_was_set(CLOCK_SET_WALL | CLOCK_SET_BOOT);
@@ -1924,20 +1847,19 @@ void timekeeping_inject_sleeptime64(const struct timespec64 *delta)
  */
 void timekeeping_resume(void)
 {
-	struct timekeeper *tk = &tk_core.timekeeper;
-	struct clocksource *clock = tk->tkr_mono.clock;
-	unsigned long flags;
+	struct timekeeper *tks = &tk_core.shadow_timekeeper;
+	struct clocksource *clock = tks->tkr_mono.clock;
 	struct timespec64 ts_new, ts_delta;
-	u64 cycle_now, nsec;
 	bool inject_sleeptime = false;
+	u64 cycle_now, nsec;
+	unsigned long flags;
 
 	read_persistent_clock64(&ts_new);
 
 	clockevents_resume();
 	clocksource_resume();
 
-	raw_spin_lock_irqsave(&timekeeper_lock, flags);
-	write_seqcount_begin(&tk_core.seq);
+	raw_spin_lock_irqsave(&tk_core.lock, flags);
 
 	/*
 	 * After system resumes, we need to calculate the suspended time and
@@ -1951,7 +1873,7 @@ void timekeeping_resume(void)
 	 * The less preferred source will only be tried if there is no better
 	 * usable source. The rtc part is handled separately in rtc core code.
 	 */
-	cycle_now = tk_clock_read(&tk->tkr_mono);
+	cycle_now = tk_clock_read(&tks->tkr_mono);
 	nsec = clocksource_stop_suspend_timing(clock, cycle_now);
 	if (nsec > 0) {
 		ts_delta = ns_to_timespec64(nsec);
@@ -1963,18 +1885,17 @@ void timekeeping_resume(void)
 
 	if (inject_sleeptime) {
 		suspend_timing_needed = false;
-		__timekeeping_inject_sleeptime(tk, &ts_delta);
+		__timekeeping_inject_sleeptime(tks, &ts_delta);
 	}
 
 	/* Re-base the last cycle value */
-	tk->tkr_mono.cycle_last = cycle_now;
-	tk->tkr_raw.cycle_last  = cycle_now;
+	tks->tkr_mono.cycle_last = cycle_now;
+	tks->tkr_raw.cycle_last  = cycle_now;
 
-	tk->ntp_error = 0;
+	tks->ntp_error = 0;
 	timekeeping_suspended = 0;
-	timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET);
-	write_seqcount_end(&tk_core.seq);
-	raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
+	timekeeping_update_from_shadow(&tk_core, TK_CLOCK_WAS_SET);
+	raw_spin_unlock_irqrestore(&tk_core.lock, flags);
 
 	touch_softlockup_watchdog();
 
@@ -1986,11 +1907,11 @@ void timekeeping_resume(void)
 
 int timekeeping_suspend(void)
 {
-	struct timekeeper *tk = &tk_core.timekeeper;
-	unsigned long flags;
-	struct timespec64		delta, delta_delta;
-	static struct timespec64	old_delta;
+	struct timekeeper *tks = &tk_core.shadow_timekeeper;
+	struct timespec64 delta, delta_delta;
+	static struct timespec64 old_delta;
 	struct clocksource *curr_clock;
+	unsigned long flags;
 	u64 cycle_now;
 
 	read_persistent_clock64(&timekeeping_suspend_time);
@@ -2005,9 +1926,8 @@ int timekeeping_suspend(void)
 
 	suspend_timing_needed = true;
 
-	raw_spin_lock_irqsave(&timekeeper_lock, flags);
-	write_seqcount_begin(&tk_core.seq);
-	timekeeping_forward_now(tk);
+	raw_spin_lock_irqsave(&tk_core.lock, flags);
+	timekeeping_forward_now(tks);
 	timekeeping_suspended = 1;
 
 	/*
@@ -2015,8 +1935,8 @@ int timekeeping_suspend(void)
 	 * just read from the current clocksource. Save this to potentially
 	 * use in suspend timing.
 	 */
-	curr_clock = tk->tkr_mono.clock;
-	cycle_now = tk->tkr_mono.cycle_last;
+	curr_clock = tks->tkr_mono.clock;
+	cycle_now = tks->tkr_mono.cycle_last;
 	clocksource_start_suspend_timing(curr_clock, cycle_now);
 
 	if (persistent_clock_exists) {
@@ -2026,7 +1946,7 @@ int timekeeping_suspend(void)
 		 * try to compensate so the difference in system time
 		 * and persistent_clock time stays close to constant.
 		 */
-		delta = timespec64_sub(tk_xtime(tk), timekeeping_suspend_time);
+		delta = timespec64_sub(tk_xtime(tks), timekeeping_suspend_time);
 		delta_delta = timespec64_sub(delta, old_delta);
 		if (abs(delta_delta.tv_sec) >= 2) {
 			/*
@@ -2041,10 +1961,9 @@ int timekeeping_suspend(void)
 		}
 	}
 
-	timekeeping_update(tk, TK_MIRROR);
-	halt_fast_timekeeper(tk);
-	write_seqcount_end(&tk_core.seq);
-	raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
+	timekeeping_update_from_shadow(&tk_core, 0);
+	halt_fast_timekeeper(tks);
+	raw_spin_unlock_irqrestore(&tk_core.lock, flags);
 
 	tick_suspend();
 	clocksource_suspend();
@@ -2149,16 +2068,17 @@ static __always_inline void timekeeping_apply_adjustment(struct timekeeper *tk,
  */
 static void timekeeping_adjust(struct timekeeper *tk, s64 offset)
 {
+	u64 ntp_tl = ntp_tick_length();
 	u32 mult;
 
 	/*
 	 * Determine the multiplier from the current NTP tick length.
 	 * Avoid expensive division when the tick length doesn't change.
 	 */
-	if (likely(tk->ntp_tick == ntp_tick_length())) {
+	if (likely(tk->ntp_tick == ntp_tl)) {
 		mult = tk->tkr_mono.mult - tk->ntp_err_mult;
 	} else {
-		tk->ntp_tick = ntp_tick_length();
+		tk->ntp_tick = ntp_tl;
 		mult = div64_u64((tk->ntp_tick >> tk->ntp_error_shift) -
 				 tk->xtime_remainder, tk->cycle_interval);
 	}
@@ -2297,28 +2217,24 @@ static u64 logarithmic_accumulation(struct timekeeper *tk, u64 offset,
  */
 static bool timekeeping_advance(enum timekeeping_adv_mode mode)
 {
+	struct timekeeper *tk = &tk_core.shadow_timekeeper;
 	struct timekeeper *real_tk = &tk_core.timekeeper;
-	struct timekeeper *tk = &shadow_timekeeper;
-	u64 offset;
-	int shift = 0, maxshift;
 	unsigned int clock_set = 0;
-	unsigned long flags;
+	int shift = 0, maxshift;
+	u64 offset;
 
-	raw_spin_lock_irqsave(&timekeeper_lock, flags);
+	guard(raw_spinlock_irqsave)(&tk_core.lock);
 
 	/* Make sure we're fully resumed: */
 	if (unlikely(timekeeping_suspended))
-		goto out;
+		return false;
 
 	offset = clocksource_delta(tk_clock_read(&tk->tkr_mono),
 				   tk->tkr_mono.cycle_last, tk->tkr_mono.mask);
 
 	/* Check if there's really nothing to do */
 	if (offset < real_tk->cycle_interval && mode == TK_ADV_TICK)
-		goto out;
-
-	/* Do some additional sanity checking */
-	timekeeping_check_update(tk, offset);
+		return false;
 
 	/*
 	 * With NO_HZ we may have to accumulate many cycle_intervals
@@ -2334,8 +2250,7 @@ static bool timekeeping_advance(enum timekeeping_adv_mode mode)
 	maxshift = (64 - (ilog2(ntp_tick_length())+1)) - 1;
 	shift = min(shift, maxshift);
 	while (offset >= tk->cycle_interval) {
-		offset = logarithmic_accumulation(tk, offset, shift,
-							&clock_set);
+		offset = logarithmic_accumulation(tk, offset, shift, &clock_set);
 		if (offset < tk->cycle_interval<<shift)
 			shift--;
 	}
@@ -2349,23 +2264,7 @@ static bool timekeeping_advance(enum timekeeping_adv_mode mode)
 	 */
 	clock_set |= accumulate_nsecs_to_secs(tk);
 
-	write_seqcount_begin(&tk_core.seq);
-	/*
-	 * Update the real timekeeper.
-	 *
-	 * We could avoid this memcpy by switching pointers, but that
-	 * requires changes to all other timekeeper usage sites as
-	 * well, i.e. move the timekeeper pointer getter into the
-	 * spinlocked/seqcount protected sections. And we trade this
-	 * memcpy under the tk_core.seq against one before we start
-	 * updating.
-	 */
-	timekeeping_update(tk, clock_set);
-	memcpy(real_tk, tk, sizeof(*tk));
-	/* The memcpy must come last. Do not put anything here! */
-	write_seqcount_end(&tk_core.seq);
-out:
-	raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
+	timekeeping_update_from_shadow(&tk_core, clock_set);
 
 	return !!clock_set;
 }
@@ -2658,13 +2557,10 @@ EXPORT_SYMBOL_GPL(random_get_entropy_fallback);
  */
 int do_adjtimex(struct __kernel_timex *txc)
 {
-	struct timekeeper *tk = &tk_core.timekeeper;
 	struct audit_ntp_data ad;
 	bool offset_set = false;
 	bool clock_set = false;
 	struct timespec64 ts;
-	unsigned long flags;
-	s32 orig_tai, tai;
 	int ret;
 
 	/* Validate the data before disabling interrupts */
@@ -2675,6 +2571,7 @@ int do_adjtimex(struct __kernel_timex *txc)
 
 	if (txc->modes & ADJ_SETOFFSET) {
 		struct timespec64 delta;
+
 		delta.tv_sec  = txc->time.tv_sec;
 		delta.tv_nsec = txc->time.tv_usec;
 		if (!(txc->modes & ADJ_NANO))
@@ -2692,21 +2589,21 @@ int do_adjtimex(struct __kernel_timex *txc)
 	ktime_get_real_ts64(&ts);
 	add_device_randomness(&ts, sizeof(ts));
 
-	raw_spin_lock_irqsave(&timekeeper_lock, flags);
-	write_seqcount_begin(&tk_core.seq);
+	scoped_guard (raw_spinlock_irqsave, &tk_core.lock) {
+		struct timekeeper *tks = &tk_core.shadow_timekeeper;
+		s32 orig_tai, tai;
 
-	orig_tai = tai = tk->tai_offset;
-	ret = __do_adjtimex(txc, &ts, &tai, &ad);
+		orig_tai = tai = tks->tai_offset;
+		ret = __do_adjtimex(txc, &ts, &tai, &ad);
 
-	if (tai != orig_tai) {
-		__timekeeping_set_tai_offset(tk, tai);
-		timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET);
-		clock_set = true;
+		if (tai != orig_tai) {
+			__timekeeping_set_tai_offset(tks, tai);
+			timekeeping_update_from_shadow(&tk_core, TK_CLOCK_WAS_SET);
+			clock_set = true;
+		} else {
+			tk_update_leap_state_all(&tk_core);
+		}
 	}
-	tk_update_leap_state(tk);
-
-	write_seqcount_end(&tk_core.seq);
-	raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
 
 	audit_ntp_log(&ad);
 
@@ -2730,15 +2627,8 @@ int do_adjtimex(struct __kernel_timex *txc)
  */
 void hardpps(const struct timespec64 *phase_ts, const struct timespec64 *raw_ts)
 {
-	unsigned long flags;
-
-	raw_spin_lock_irqsave(&timekeeper_lock, flags);
-	write_seqcount_begin(&tk_core.seq);
-
+	guard(raw_spinlock_irqsave)(&tk_core.lock);
 	__hardpps(phase_ts, raw_ts);
-
-	write_seqcount_end(&tk_core.seq);
-	raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
 }
 EXPORT_SYMBOL(hardpps);
 #endif /* CONFIG_NTP_PPS */
diff --git a/kernel/time/timekeeping_internal.h b/kernel/time/timekeeping_internal.h
index 0bbae825bc02..63e600e943a7 100644
--- a/kernel/time/timekeeping_internal.h
+++ b/kernel/time/timekeeping_internal.h
@@ -30,7 +30,6 @@ static inline void timekeeping_inc_mg_floor_swaps(void)
 
 #endif
 
-#ifdef CONFIG_CLOCKSOURCE_VALIDATE_LAST_CYCLE
 static inline u64 clocksource_delta(u64 now, u64 last, u64 mask)
 {
 	u64 ret = (now - last) & mask;
@@ -41,14 +40,9 @@ static inline u64 clocksource_delta(u64 now, u64 last, u64 mask)
 	 */
 	return ret & ~(mask >> 1) ? 0 : ret;
 }
-#else
-static inline u64 clocksource_delta(u64 now, u64 last, u64 mask)
-{
-	return (now - last) & mask;
-}
-#endif
 
 /* Semi public for serialization of non timekeeper VDSO updates. */
-extern raw_spinlock_t timekeeper_lock;
+unsigned long timekeeper_lock_irqsave(void);
+void timekeeper_unlock_irqrestore(unsigned long flags);
 
 #endif /* _TIMEKEEPING_INTERNAL_H */
diff --git a/kernel/time/timer.c b/kernel/time/timer.c
index 06f0bc1db6d9..a5860bf6d16f 100644
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -37,7 +37,6 @@
 #include <linux/tick.h>
 #include <linux/kallsyms.h>
 #include <linux/irq_work.h>
-#include <linux/sched/signal.h>
 #include <linux/sched/sysctl.h>
 #include <linux/sched/nohz.h>
 #include <linux/sched/debug.h>
@@ -2422,7 +2421,8 @@ static inline void __run_timers(struct timer_base *base)
 
 static void __run_timer_base(struct timer_base *base)
 {
-	if (time_before(jiffies, base->next_expiry))
+	/* Can race against a remote CPU updating next_expiry under the lock */
+	if (time_before(jiffies, READ_ONCE(base->next_expiry)))
 		return;
 
 	timer_base_lock_expiry(base);
@@ -2526,141 +2526,6 @@ void update_process_times(int user_tick)
 		run_posix_cpu_timers();
 }
 
-/*
- * Since schedule_timeout()'s timer is defined on the stack, it must store
- * the target task on the stack as well.
- */
-struct process_timer {
-	struct timer_list timer;
-	struct task_struct *task;
-};
-
-static void process_timeout(struct timer_list *t)
-{
-	struct process_timer *timeout = from_timer(timeout, t, timer);
-
-	wake_up_process(timeout->task);
-}
-
-/**
- * schedule_timeout - sleep until timeout
- * @timeout: timeout value in jiffies
- *
- * Make the current task sleep until @timeout jiffies have elapsed.
- * The function behavior depends on the current task state
- * (see also set_current_state() description):
- *
- * %TASK_RUNNING - the scheduler is called, but the task does not sleep
- * at all. That happens because sched_submit_work() does nothing for
- * tasks in %TASK_RUNNING state.
- *
- * %TASK_UNINTERRUPTIBLE - at least @timeout jiffies are guaranteed to
- * pass before the routine returns unless the current task is explicitly
- * woken up, (e.g. by wake_up_process()).
- *
- * %TASK_INTERRUPTIBLE - the routine may return early if a signal is
- * delivered to the current task or the current task is explicitly woken
- * up.
- *
- * The current task state is guaranteed to be %TASK_RUNNING when this
- * routine returns.
- *
- * Specifying a @timeout value of %MAX_SCHEDULE_TIMEOUT will schedule
- * the CPU away without a bound on the timeout. In this case the return
- * value will be %MAX_SCHEDULE_TIMEOUT.
- *
- * Returns 0 when the timer has expired otherwise the remaining time in
- * jiffies will be returned. In all cases the return value is guaranteed
- * to be non-negative.
- */
-signed long __sched schedule_timeout(signed long timeout)
-{
-	struct process_timer timer;
-	unsigned long expire;
-
-	switch (timeout)
-	{
-	case MAX_SCHEDULE_TIMEOUT:
-		/*
-		 * These two special cases are useful to be comfortable
-		 * in the caller. Nothing more. We could take
-		 * MAX_SCHEDULE_TIMEOUT from one of the negative value
-		 * but I' d like to return a valid offset (>=0) to allow
-		 * the caller to do everything it want with the retval.
-		 */
-		schedule();
-		goto out;
-	default:
-		/*
-		 * Another bit of PARANOID. Note that the retval will be
-		 * 0 since no piece of kernel is supposed to do a check
-		 * for a negative retval of schedule_timeout() (since it
-		 * should never happens anyway). You just have the printk()
-		 * that will tell you if something is gone wrong and where.
-		 */
-		if (timeout < 0) {
-			printk(KERN_ERR "schedule_timeout: wrong timeout "
-				"value %lx\n", timeout);
-			dump_stack();
-			__set_current_state(TASK_RUNNING);
-			goto out;
-		}
-	}
-
-	expire = timeout + jiffies;
-
-	timer.task = current;
-	timer_setup_on_stack(&timer.timer, process_timeout, 0);
-	__mod_timer(&timer.timer, expire, MOD_TIMER_NOTPENDING);
-	schedule();
-	del_timer_sync(&timer.timer);
-
-	/* Remove the timer from the object tracker */
-	destroy_timer_on_stack(&timer.timer);
-
-	timeout = expire - jiffies;
-
- out:
-	return timeout < 0 ? 0 : timeout;
-}
-EXPORT_SYMBOL(schedule_timeout);
-
-/*
- * We can use __set_current_state() here because schedule_timeout() calls
- * schedule() unconditionally.
- */
-signed long __sched schedule_timeout_interruptible(signed long timeout)
-{
-	__set_current_state(TASK_INTERRUPTIBLE);
-	return schedule_timeout(timeout);
-}
-EXPORT_SYMBOL(schedule_timeout_interruptible);
-
-signed long __sched schedule_timeout_killable(signed long timeout)
-{
-	__set_current_state(TASK_KILLABLE);
-	return schedule_timeout(timeout);
-}
-EXPORT_SYMBOL(schedule_timeout_killable);
-
-signed long __sched schedule_timeout_uninterruptible(signed long timeout)
-{
-	__set_current_state(TASK_UNINTERRUPTIBLE);
-	return schedule_timeout(timeout);
-}
-EXPORT_SYMBOL(schedule_timeout_uninterruptible);
-
-/*
- * Like schedule_timeout_uninterruptible(), except this task will not contribute
- * to load average.
- */
-signed long __sched schedule_timeout_idle(signed long timeout)
-{
-	__set_current_state(TASK_IDLE);
-	return schedule_timeout(timeout);
-}
-EXPORT_SYMBOL(schedule_timeout_idle);
-
 #ifdef CONFIG_HOTPLUG_CPU
 static void migrate_timer_list(struct timer_base *new_base, struct hlist_head *head)
 {
@@ -2757,59 +2622,3 @@ void __init init_timers(void)
 	posix_cputimers_init_work();
 	open_softirq(TIMER_SOFTIRQ, run_timer_softirq);
 }
-
-/**
- * msleep - sleep safely even with waitqueue interruptions
- * @msecs: Time in milliseconds to sleep for
- */
-void msleep(unsigned int msecs)
-{
-	unsigned long timeout = msecs_to_jiffies(msecs);
-
-	while (timeout)
-		timeout = schedule_timeout_uninterruptible(timeout);
-}
-
-EXPORT_SYMBOL(msleep);
-
-/**
- * msleep_interruptible - sleep waiting for signals
- * @msecs: Time in milliseconds to sleep for
- */
-unsigned long msleep_interruptible(unsigned int msecs)
-{
-	unsigned long timeout = msecs_to_jiffies(msecs);
-
-	while (timeout && !signal_pending(current))
-		timeout = schedule_timeout_interruptible(timeout);
-	return jiffies_to_msecs(timeout);
-}
-
-EXPORT_SYMBOL(msleep_interruptible);
-
-/**
- * usleep_range_state - Sleep for an approximate time in a given state
- * @min:	Minimum time in usecs to sleep
- * @max:	Maximum time in usecs to sleep
- * @state:	State of the current task that will be while sleeping
- *
- * In non-atomic context where the exact wakeup time is flexible, use
- * usleep_range_state() instead of udelay().  The sleep improves responsiveness
- * by avoiding the CPU-hogging busy-wait of udelay(), and the range reduces
- * power usage by allowing hrtimers to take advantage of an already-
- * scheduled interrupt instead of scheduling a new one just for this sleep.
- */
-void __sched usleep_range_state(unsigned long min, unsigned long max,
-				unsigned int state)
-{
-	ktime_t exp = ktime_add_us(ktime_get(), min);
-	u64 delta = (u64)(max - min) * NSEC_PER_USEC;
-
-	for (;;) {
-		__set_current_state(state);
-		/* Do not return before the requested sleep time has elapsed */
-		if (!schedule_hrtimeout_range(&exp, delta, HRTIMER_MODE_ABS))
-			break;
-	}
-}
-EXPORT_SYMBOL(usleep_range_state);
diff --git a/kernel/time/vsyscall.c b/kernel/time/vsyscall.c
index 28706a13c222..05d383143165 100644
--- a/kernel/time/vsyscall.c
+++ b/kernel/time/vsyscall.c
@@ -151,9 +151,8 @@ void update_vsyscall_tz(void)
 unsigned long vdso_update_begin(void)
 {
 	struct vdso_data *vdata = __arch_get_k_vdso_data();
-	unsigned long flags;
+	unsigned long flags = timekeeper_lock_irqsave();
 
-	raw_spin_lock_irqsave(&timekeeper_lock, flags);
 	vdso_write_begin(vdata);
 	return flags;
 }
@@ -172,5 +171,5 @@ void vdso_update_end(unsigned long flags)
 
 	vdso_write_end(vdata);
 	__arch_sync_vdso_data(vdata);
-	raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
+	timekeeper_unlock_irqrestore(flags);
 }