Merge tag 'timers_urgent_for_v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer fixes from Borislav Petkov:

 - Reset hrtimers correctly when a CPU hotplug state traversal happens
   "half-ways" and leaves hrtimers not (re-)initialized properly

 - Annotate accesses to a timer group's ignore flag to prevent KCSAN
   from raising data_race warnings

 - Make sure timer group initialization is visible to timer tree walkers
   and avoid a hypothetical race

 - Fix another race between CPU hotplug and idle entry/exit where timers
   on a fully idle system are getting ignored

 - Fix a case where an ignored signal is still being handled which it
   shouldn't be

* tag 'timers_urgent_for_v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  hrtimers: Handle CPU state correctly on hotplug
  timers/migration: Annotate accesses to ignore flag
  timers/migration: Enforce group initialization visibility to tree walkers
  timers/migration: Fix another race between hotplug and idle entry/exit
  signal/posixtimers: Handle ignore/blocked sequences correctly

1 files changed, 10 insertions, 1 deletions

diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index 80fe3749d2db..030426c8c944 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -2202,6 +2202,15 @@ int hrtimers_prepare_cpu(unsigned int cpu)
 	}
 
 	cpu_base->cpu = cpu;
+	hrtimer_cpu_base_init_expiry_lock(cpu_base);
+	return 0;
+}
+
+int hrtimers_cpu_starting(unsigned int cpu)
+{
+	struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases);
+
+	/* Clear out any left over state from a CPU down operation */
 	cpu_base->active_bases = 0;
 	cpu_base->hres_active = 0;
 	cpu_base->hang_detected = 0;
@@ -2210,7 +2219,6 @@ int hrtimers_prepare_cpu(unsigned int cpu)
 	cpu_base->expires_next = KTIME_MAX;
 	cpu_base->softirq_expires_next = KTIME_MAX;
 	cpu_base->online = 1;
-	hrtimer_cpu_base_init_expiry_lock(cpu_base);
 	return 0;
 }
 
@@ -2286,5 +2294,6 @@ int hrtimers_cpu_dying(unsigned int dying_cpu)
 void __init hrtimers_init(void)
 {
 	hrtimers_prepare_cpu(smp_processor_id());
+	hrtimers_cpu_starting(smp_processor_id());
 	open_softirq(HRTIMER_SOFTIRQ, hrtimer_run_softirq);
 }