1 files changed, 30 insertions, 4 deletions

diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index f78777abe769..dea4c9124ac8 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -590,7 +590,6 @@ static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
                         list_add_tail(&timer->cb_entry,
                                       &base->cpu_base->cb_pending);
                         timer->state = HRTIMER_STATE_PENDING;
-                        raise_softirq(HRTIMER_SOFTIRQ);
                         return 1;
                 default:
                         BUG();
@@ -633,6 +632,11 @@ static int hrtimer_switch_to_hres(void)
         return 1;
 }
 
+static inline void hrtimer_raise_softirq(void)
+{
+        raise_softirq(HRTIMER_SOFTIRQ);
+}
+
 #else
 
 static inline int hrtimer_hres_active(void) { return 0; }
@@ -651,6 +655,7 @@ static inline int hrtimer_reprogram(struct hrtimer *timer,
 {
         return 0;
 }
+static inline void hrtimer_raise_softirq(void) { }
 
 #endif /* CONFIG_HIGH_RES_TIMERS */
 
@@ -850,7 +855,7 @@ hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
 {
         struct hrtimer_clock_base *base, *new_base;
         unsigned long flags;
-        int ret;
+        int ret, raise;
 
         base = lock_hrtimer_base(timer, &flags);
 
@@ -884,8 +889,18 @@ hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
         enqueue_hrtimer(timer, new_base,
                         new_base->cpu_base == &__get_cpu_var(hrtimer_bases));
 
+        /*
+         * The timer may be expired and moved to the cb_pending
+         * list. We can not raise the softirq with base lock held due
+         * to a possible deadlock with runqueue lock.
+         */
+        raise = timer->state == HRTIMER_STATE_PENDING;
+
         unlock_hrtimer_base(timer, &flags);
 
+        if (raise)
+                hrtimer_raise_softirq();
+
         return ret;
 }
 EXPORT_SYMBOL_GPL(hrtimer_start);
@@ -1080,8 +1095,19 @@ static void run_hrtimer_pending(struct hrtimer_cpu_base *cpu_base)
                          * If the timer was rearmed on another CPU, reprogram
                          * the event device.
                          */
-                        if (timer->base->first == &timer->node)
-                                hrtimer_reprogram(timer, timer->base);
+                        struct hrtimer_clock_base *base = timer->base;
+
+                        if (base->first == &timer->node &&
+                            hrtimer_reprogram(timer, base)) {
+                                /*
+                                 * Timer is expired. Thus move it from tree to
+                                 * pending list again.
+                                 */
+                                __remove_hrtimer(timer, base,
+                                                 HRTIMER_STATE_PENDING, 0);
+                                list_add_tail(&timer->cb_entry,
+                                              &base->cpu_base->cb_pending);
+                        }
                 }
         }
         spin_unlock_irq(&cpu_base->lock);