genirq: No need to check IRQTF_DIED before stopping a thread handler

Since 63706172f332fd3f6e7458ebfb35fa6de9c21dc5 kthread_stop() is not
afraid of dead kernel threads. So no need to check if a thread is
alive before stopping it. These checks still were racy.

Reported-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Link: http://lkml.kernel.org/r/20120309135939.GC2114@dhcp-26-207.brq.redhat.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 2 insertions, 4 deletions

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 0fa3ce998ecb..3feab4ab6877 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -1106,8 +1106,7 @@ out_thread:
                 struct task_struct *t = new->thread;
 
                 new->thread = NULL;
-                if (likely(!test_bit(IRQTF_DIED, &new->thread_flags)))
-                        kthread_stop(t);
+                kthread_stop(t);
                 put_task_struct(t);
         }
 out_mput:
@@ -1217,8 +1216,7 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
 #endif
 
         if (action->thread) {
-                if (!test_bit(IRQTF_DIED, &action->thread_flags))
-                        kthread_stop(action->thread);
+                kthread_stop(action->thread);
                 put_task_struct(action->thread);
         }