1 files changed, 14 insertions, 7 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index f28f19e65b59..f06950c8a6ce 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -668,6 +668,8 @@ const_debug unsigned int sysctl_sched_nr_migrate = 32;
  */
 unsigned int sysctl_sched_rt_period = 1000000;
 
+static __read_mostly int scheduler_running;
+
 /*
  * part of the period that we allow rt tasks to run in us.
  * default: 0.95s
@@ -689,14 +691,16 @@ unsigned long long cpu_clock(int cpu)
         unsigned long flags;
         struct rq *rq;
 
-        local_irq_save(flags);
-        rq = cpu_rq(cpu);
         /*
          * Only call sched_clock() if the scheduler has already been
          * initialized (some code might call cpu_clock() very early):
          */
-        if (rq->idle)
-                update_rq_clock(rq);
+        if (unlikely(!scheduler_running))
+                return 0;
+
+        local_irq_save(flags);
+        rq = cpu_rq(cpu);
+        update_rq_clock(rq);
         now = rq->clock;
         local_irq_restore(flags);
 
@@ -1831,6 +1835,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
         long old_state;
         struct rq *rq;
 
+        smp_wmb();
         rq = task_rq_lock(p, &flags);
         old_state = p->state;
         if (!(old_state & state))
@@ -3766,7 +3771,7 @@ void scheduler_tick(void)
 
 #if defined(CONFIG_PREEMPT) && defined(CONFIG_DEBUG_PREEMPT)
 
-void add_preempt_count(int val)
+void __kprobes add_preempt_count(int val)
 {
         /*
          * Underflow?
@@ -3782,7 +3787,7 @@ void add_preempt_count(int val)
 }
 EXPORT_SYMBOL(add_preempt_count);
 
-void sub_preempt_count(int val)
+void __kprobes sub_preempt_count(int val)
 {
         /*
          * Underflow?
@@ -3884,7 +3889,7 @@ pick_next_task(struct rq *rq, struct task_struct *prev)
 asmlinkage void __sched schedule(void)
 {
         struct task_struct *prev, *next;
-        long *switch_count;
+        unsigned long *switch_count;
         struct rq *rq;
         int cpu;
 
@@ -7283,6 +7288,8 @@ void __init sched_init(void)
          * During early bootup we pretend to be a normal task:
          */
         current->sched_class = &fair_sched_class;
+
+        scheduler_running = 1;
 }
 
 #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP