Messages in this thread Patch in this message | | | From | Kamal Mostafa <> | Subject | [PATCH 3.8 12/65] hrtimer: Set expiry time before switch_hrtimer_base() | Date | Tue, 24 Jun 2014 13:29:32 -0700 |
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3.8.13.25 -stable review patch. If anyone has any objections, please let me know.
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From: Viresh Kumar <viresh.kumar@linaro.org>
commit 84ea7fe37908254c3bd90910921f6e1045c1747a upstream.
switch_hrtimer_base() calls hrtimer_check_target() which ensures that we do not migrate a timer to a remote cpu if the timer expires before the current programmed expiry time on that remote cpu.
But __hrtimer_start_range_ns() calls switch_hrtimer_base() before the new expiry time is set. So the sanity check in hrtimer_check_target() is operating on stale or even uninitialized data.
Update expiry time before calling switch_hrtimer_base().
[ tglx: Rewrote changelog once again ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: linaro-kernel@lists.linaro.org Cc: linaro-networking@linaro.org Cc: fweisbec@gmail.com Cc: arvind.chauhan@arm.com Link: http://lkml.kernel.org/r/81999e148745fc51bbcd0615823fbab9b2e87e23.1399882253.git.viresh.kumar@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- kernel/hrtimer.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index 9873816..20e88af 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -980,11 +980,8 @@ int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, /* Remove an active timer from the queue: */ ret = remove_hrtimer(timer, base); - /* Switch the timer base, if necessary: */ - new_base = switch_hrtimer_base(timer, base, mode & HRTIMER_MODE_PINNED); - if (mode & HRTIMER_MODE_REL) { - tim = ktime_add_safe(tim, new_base->get_time()); + tim = ktime_add_safe(tim, base->get_time()); /* * CONFIG_TIME_LOW_RES is a temporary way for architectures * to signal that they simply return xtime in @@ -999,6 +996,9 @@ int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, hrtimer_set_expires_range_ns(timer, tim, delta_ns); + /* Switch the timer base, if necessary: */ + new_base = switch_hrtimer_base(timer, base, mode & HRTIMER_MODE_PINNED); + timer_stats_hrtimer_set_start_info(timer); leftmost = enqueue_hrtimer(timer, new_base); -- 1.9.1
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