| From 84ea7fe37908254c3bd90910921f6e1045c1747a Mon Sep 17 00:00:00 2001 |
| From: Viresh Kumar <viresh.kumar@linaro.org> |
| Date: Mon, 12 May 2014 13:42:29 +0530 |
| Subject: hrtimer: Set expiry time before switch_hrtimer_base() |
| |
| 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: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| kernel/hrtimer.c | 8 ++++---- |
| 1 file changed, 4 insertions(+), 4 deletions(-) |
| |
| --- a/kernel/hrtimer.c |
| +++ b/kernel/hrtimer.c |
| @@ -999,11 +999,8 @@ int __hrtimer_start_range_ns(struct hrti |
| /* 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 |
| @@ -1018,6 +1015,9 @@ int __hrtimer_start_range_ns(struct hrti |
| |
| 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); |