From: tip-bot for Peter Zijlstra <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: peterz@infradead.org, hpa@zytor.com, mingo@kernel.org,
tglx@linutronix.de, linux-kernel@vger.kernel.org,
oleg@redhat.com
Subject: [tip:timers/core] hrtimer: Fix hrtimer_is_queued() hole
Date: Thu, 18 Jun 2015 15:18:53 -0700 [thread overview]
Message-ID: <tip-8edfb0362e8e52dec2de08fa163af01c9da2c9d0@git.kernel.org> (raw)
In-Reply-To: <20150611124743.175989138@infradead.org>
Commit-ID: 8edfb0362e8e52dec2de08fa163af01c9da2c9d0
Gitweb: http://git.kernel.org/tip/8edfb0362e8e52dec2de08fa163af01c9da2c9d0
Author: Peter Zijlstra <peterz@infradead.org>
AuthorDate: Thu, 11 Jun 2015 14:46:45 +0200
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Fri, 19 Jun 2015 00:09:56 +0200
hrtimer: Fix hrtimer_is_queued() hole
A queued hrtimer that gets restarted (hrtimer_start*() while
hrtimer_is_queued()) will briefly appear as unqueued/inactive, even
though the timer has always been active, we just moved it.
Close this hole by preserving timer->state in
hrtimer_start_range_ns()'s remove_hrtimer() call.
Reported-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: ktkhai@parallels.com
Cc: rostedt@goodmis.org
Cc: juri.lelli@gmail.com
Cc: pang.xunlei@linaro.org
Cc: wanpeng.li@linux.intel.com
Cc: umgwanakikbuti@gmail.com
Link: http://lkml.kernel.org/r/20150611124743.175989138@infradead.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
kernel/time/hrtimer.c | 23 +++++++++++++----------
1 file changed, 13 insertions(+), 10 deletions(-)
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index b1b795e..1604157 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -889,10 +889,10 @@ static void __remove_hrtimer(struct hrtimer *timer,
* remove hrtimer, called with base lock held
*/
static inline int
-remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base)
+remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base, bool restart)
{
if (hrtimer_is_queued(timer)) {
- unsigned long state;
+ unsigned long state = timer->state;
int reprogram;
/*
@@ -906,12 +906,15 @@ remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base)
debug_deactivate(timer);
timer_stats_hrtimer_clear_start_info(timer);
reprogram = base->cpu_base == this_cpu_ptr(&hrtimer_bases);
- /*
- * We must preserve the CALLBACK state flag here,
- * otherwise we could move the timer base in
- * switch_hrtimer_base.
- */
- state = timer->state & HRTIMER_STATE_CALLBACK;
+
+ if (!restart) {
+ /*
+ * We must preserve the CALLBACK state flag here,
+ * otherwise we could move the timer base in
+ * switch_hrtimer_base.
+ */
+ state &= HRTIMER_STATE_CALLBACK;
+ }
__remove_hrtimer(timer, base, state, reprogram);
return 1;
}
@@ -936,7 +939,7 @@ void hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
base = lock_hrtimer_base(timer, &flags);
/* Remove an active timer from the queue: */
- remove_hrtimer(timer, base);
+ remove_hrtimer(timer, base, true);
if (mode & HRTIMER_MODE_REL) {
tim = ktime_add_safe(tim, base->get_time());
@@ -1005,7 +1008,7 @@ int hrtimer_try_to_cancel(struct hrtimer *timer)
base = lock_hrtimer_base(timer, &flags);
if (!hrtimer_callback_running(timer))
- ret = remove_hrtimer(timer, base);
+ ret = remove_hrtimer(timer, base, false);
unlock_hrtimer_base(timer, &flags);
next prev parent reply other threads:[~2015-06-18 22:19 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-11 12:46 [PATCH 00/18] sched: balance callbacks v4 Peter Zijlstra
2015-06-11 12:46 ` [PATCH 01/18] sched: Replace post_schedule with a balance callback list Peter Zijlstra
2015-06-11 15:32 ` Kirill Tkhai
2015-06-18 23:00 ` [tip:sched/hrtimers] " tip-bot for Peter Zijlstra
2015-06-11 12:46 ` [PATCH 02/18] sched: Use replace normalize_task() with __sched_setscheduler() Peter Zijlstra
2015-06-18 23:00 ` [tip:sched/hrtimers] " tip-bot for Peter Zijlstra
2015-06-11 12:46 ` [PATCH 03/18] sched: Allow balance callbacks for check_class_changed() Peter Zijlstra
2015-06-18 23:01 ` [tip:sched/hrtimers] " tip-bot for Peter Zijlstra
2015-06-11 12:46 ` [PATCH 04/18] sched,rt: Remove return value from pull_rt_task() Peter Zijlstra
2015-06-18 23:01 ` [tip:sched/hrtimers] " tip-bot for Peter Zijlstra
2015-06-11 12:46 ` [PATCH 05/18] sched,rt: Convert switched_{from,to}_rt() / prio_changed_rt() to balance callbacks Peter Zijlstra
2015-06-18 23:01 ` [tip:sched/hrtimers] sched, rt: Convert switched_{from, to}_rt() " tip-bot for Peter Zijlstra
2015-06-11 12:46 ` [PATCH 06/18] sched,dl: Remove return value from pull_dl_task() Peter Zijlstra
2015-06-18 23:02 ` [tip:sched/hrtimers] " tip-bot for Peter Zijlstra
2015-06-11 12:46 ` [PATCH 07/18] sched,dl: Convert switched_{from,to}_dl() / prio_changed_dl() to balance callbacks Peter Zijlstra
2015-06-18 23:02 ` [tip:sched/hrtimers] sched, dl: Convert switched_{from, to}_dl() " tip-bot for Peter Zijlstra
2015-06-11 12:46 ` [PATCH 08/18] hrtimer: Remove HRTIMER_STATE_MIGRATE Peter Zijlstra
2015-06-18 22:18 ` [tip:timers/core] " tip-bot for Oleg Nesterov
2015-06-11 12:46 ` [PATCH 09/18] hrtimer: Fix hrtimer_is_queued() hole Peter Zijlstra
2015-06-18 22:18 ` tip-bot for Peter Zijlstra [this message]
2015-06-11 12:46 ` [PATCH 10/18] seqcount: Rename write_seqcount_barrier() Peter Zijlstra
2015-06-18 22:19 ` [tip:timers/core] " tip-bot for Peter Zijlstra
2015-06-11 12:46 ` [PATCH 11/18] seqcount: Introduce raw_write_seqcount_barrier() Peter Zijlstra
2015-06-11 15:33 ` Paul E. McKenney
2015-06-11 21:45 ` Paul E. McKenney
2015-06-12 7:08 ` Peter Zijlstra
2015-06-12 18:59 ` Oleg Nesterov
2015-06-17 12:29 ` Peter Zijlstra
2015-06-17 14:57 ` Paul E. McKenney
2015-06-17 15:11 ` Peter Zijlstra
2015-06-17 15:42 ` Paul E. McKenney
2015-06-17 16:58 ` Peter Zijlstra
2015-06-17 15:49 ` Peter Zijlstra
2015-06-17 16:37 ` Paul E. McKenney
2015-06-17 17:11 ` Peter Zijlstra
2015-06-17 18:02 ` Paul E. McKenney
2015-06-18 9:15 ` Peter Zijlstra
2015-06-18 9:40 ` Ingo Molnar
2015-06-18 10:40 ` Peter Zijlstra
2015-06-18 16:54 ` Paul E. McKenney
2015-06-18 17:10 ` Steven Rostedt
2015-06-18 17:51 ` Paul E. McKenney
2015-06-18 22:19 ` [tip:timers/core] seqcount: Introduce raw_write_seqcount_barrier( ) tip-bot for Peter Zijlstra
2015-06-11 12:46 ` [PATCH 12/18] hrtimer: Allow hrtimer::function() to free the timer Peter Zijlstra
2015-06-18 22:19 ` [tip:timers/core] " tip-bot for Peter Zijlstra
2015-06-11 12:46 ` [PATCH 13/18] sched,dl: Fix sched class hopping CBS hole Peter Zijlstra
2015-06-18 23:02 ` [tip:sched/hrtimers] " tip-bot for Peter Zijlstra
2015-06-11 12:46 ` [PATCH 14/18] sched: Move code around Peter Zijlstra
2015-06-18 23:02 ` [tip:sched/hrtimers] " tip-bot for Peter Zijlstra
2015-06-11 12:46 ` [PATCH 15/18] sched: Streamline the task migration locking a little Peter Zijlstra
2015-06-18 23:03 ` [tip:sched/hrtimers] " tip-bot for Peter Zijlstra
2015-06-11 12:46 ` [PATCH 16/18] lockdep: Simplify lock_release() Peter Zijlstra
2015-06-18 23:03 ` [tip:sched/hrtimers] " tip-bot for Peter Zijlstra
2015-06-11 12:46 ` [PATCH 17/18] lockdep: Implement lock pinning Peter Zijlstra
2015-06-18 23:03 ` [tip:sched/hrtimers] " tip-bot for Peter Zijlstra
2015-06-11 12:46 ` [PATCH 18/18] sched,lockdep: Employ " Peter Zijlstra
2015-06-18 23:04 ` [tip:sched/hrtimers] " tip-bot for Peter Zijlstra
2015-12-29 5:41 ` [PATCH 00/18] sched: balance callbacks v4 Byungchul Park
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