1 files changed, 16 insertions, 18 deletions

diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index 79747b7d9420..3b7df8653913 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -788,7 +788,6 @@ static void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp)
 {
         unsigned long long now;
         struct task_struct *p = timer->it.cpu.task;
-        int clear_dead;
 
         /*
          * Easy part: convert the reload time.
@@ -802,6 +801,7 @@ static void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp)
         }
 
         if (unlikely(p == NULL)) {
+                WARN_ON_ONCE(CPUCLOCK_PERTHREAD(timer->it_clock));
                 /*
                  * This task already died and the timer will never fire.
                  * In this case, expires is actually the dead value.
@@ -817,7 +817,6 @@ static void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp)
          */
         if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
                 cpu_clock_sample(timer->it_clock, p, &now);
-                clear_dead = p->exit_state;
         } else {
                 read_lock(&tasklist_lock);
                 if (unlikely(p->sighand == NULL)) {
@@ -833,22 +832,20 @@ static void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp)
                         goto dead;
                 } else {
                         cpu_timer_sample_group(timer->it_clock, p, &now);
-                        clear_dead = (unlikely(p->exit_state) &&
-                                      thread_group_empty(p));
+                        if (unlikely(p->exit_state) && thread_group_empty(p)) {
+                                read_unlock(&tasklist_lock);
+                                /*
+                                 * We've noticed that the thread is dead, but
+                                 * not yet reaped.  Take this opportunity to
+                                 * drop our task ref.
+                                 */
+                                clear_dead_task(timer, now);
+                                goto dead;
+                        }
                 }
                 read_unlock(&tasklist_lock);
         }
 
-        if (unlikely(clear_dead)) {
-                /*
-                 * We've noticed that the thread is dead, but
-                 * not yet reaped.  Take this opportunity to
-                 * drop our task ref.
-                 */
-                clear_dead_task(timer, now);
-                goto dead;
-        }
-
         if (now < timer->it.cpu.expires) {
                 sample_to_timespec(timer->it_clock,
                                    timer->it.cpu.expires - now,
@@ -1063,11 +1060,13 @@ void posix_cpu_timer_schedule(struct k_itimer *timer)
         struct task_struct *p = timer->it.cpu.task;
         unsigned long long now;
 
-        if (unlikely(p == NULL))
+        if (unlikely(p == NULL)) {
+                WARN_ON_ONCE(CPUCLOCK_PERTHREAD(timer->it_clock));
                 /*
                  * The task was cleaned up already, no future firings.
                  */
                 goto out;
+        }
 
         /*
          * Fetch the current sample and update the timer's expiry time.
@@ -1075,10 +1074,9 @@ void posix_cpu_timer_schedule(struct k_itimer *timer)
         if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
                 cpu_clock_sample(timer->it_clock, p, &now);
                 bump_cpu_timer(timer, now);
-                if (unlikely(p->exit_state)) {
-                        clear_dead_task(timer, now);
+                if (unlikely(p->exit_state))
                         goto out;
-                }
+
                 read_lock(&tasklist_lock); /* arm_timer needs it.  */
                 spin_lock(&p->sighand->siglock);
         } else {