1 files changed, 16 insertions, 10 deletions

diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 2b465dfde426..47e63349d1b2 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -664,14 +664,6 @@ static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
 
                 /* Timer is expired, act upon the callback mode */
                 switch(timer->cb_mode) {
-                case HRTIMER_CB_IRQSAFE_NO_RESTART:
-                        debug_hrtimer_deactivate(timer);
-                        /*
-                         * We can call the callback from here. No restart
-                         * happens, so no danger of recursion
-                         */
-                        BUG_ON(timer->function(timer) != HRTIMER_NORESTART);
-                        return 1;
                 case HRTIMER_CB_IRQSAFE_PERCPU:
                 case HRTIMER_CB_IRQSAFE_UNLOCKED:
                         /*
@@ -683,7 +675,6 @@ static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
                          */
                         debug_hrtimer_deactivate(timer);
                         return 1;
-                case HRTIMER_CB_IRQSAFE:
                 case HRTIMER_CB_SOFTIRQ:
                         /*
                          * Move everything else into the softirq pending list !
@@ -1209,6 +1200,7 @@ static void run_hrtimer_pending(struct hrtimer_cpu_base *cpu_base)
                 enum hrtimer_restart (*fn)(struct hrtimer *);
                 struct hrtimer *timer;
                 int restart;
+                int emulate_hardirq_ctx = 0;
 
                 timer = list_entry(cpu_base->cb_pending.next,
                                    struct hrtimer, cb_entry);
@@ -1217,10 +1209,24 @@ static void run_hrtimer_pending(struct hrtimer_cpu_base *cpu_base)
                 timer_stats_account_hrtimer(timer);
 
                 fn = timer->function;
+                /*
+                 * A timer might have been added to the cb_pending list
+                 * when it was migrated during a cpu-offline operation.
+                 * Emulate hardirq context for such timers.
+                 */
+                if (timer->cb_mode == HRTIMER_CB_IRQSAFE_PERCPU ||
+                    timer->cb_mode == HRTIMER_CB_IRQSAFE_UNLOCKED)
+                        emulate_hardirq_ctx = 1;
+
                 __remove_hrtimer(timer, timer->base, HRTIMER_STATE_CALLBACK, 0);
                 spin_unlock_irq(&cpu_base->lock);
 
-                restart = fn(timer);
+                if (unlikely(emulate_hardirq_ctx)) {
+                        local_irq_disable();
+                        restart = fn(timer);
+                        local_irq_enable();
+                } else
+                        restart = fn(timer);
 
                 spin_lock_irq(&cpu_base->lock);