[PATCH RT 2/3] Fix latency histogram after "hrtimer: Set expiry time before switch_hrtimer_base()"

[Steven Rostedt]

3.10.44-rt46-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Ben Hutchings <ben@xxxxxxxxxxxxxxx>

In an rt-kernel with CONFIG_MISSED_TIMER_OFFSETS_HIST enabled,
__hrtimer_start_range_ns() now crashes, as new_base is not assigned
before it is used.

Tested-by: Carsten Emde <C.Emde@xxxxxxxxx>
Cc: stable-rt@xxxxxxxxxxxxxxx
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
---
 kernel/hrtimer.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index f7a3a7a5a61b..1defbda1def8 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -1102,6 +1102,11 @@ int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
 #endif
 	}
 
+	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);
+
 #ifdef CONFIG_MISSED_TIMER_OFFSETS_HIST
 	{
 		ktime_t now = new_base->get_time();
@@ -1113,11 +1118,6 @@ int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
 	}
 #endif
 
-	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);
-- 
2.0.0


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