rcu: fix rcutorture bug

Fix an rcutorture bug that prevents the shutdown notifier from ever
actually having any effect, due to the fact that kthreads ignore all
signals.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 8 insertions, 10 deletions

diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index 3245b40952c..1cff28db56b 100644
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -136,7 +136,7 @@ static int stutter_pause_test = 0;
 #endif
 int rcutorture_runnable = RCUTORTURE_RUNNABLE_INIT;
 
-#define FULLSTOP_SIGNALED 1     /* Bail due to signal. */
+#define FULLSTOP_SHUTDOWN 1     /* Bail due to system shutdown/panic. */
 #define FULLSTOP_CLEANUP  2     /* Orderly shutdown. */
 static int fullstop;            /* stop generating callbacks at test end. */
 DEFINE_MUTEX(fullstop_mutex);   /* protect fullstop transitions and */
@@ -151,12 +151,10 @@ rcutorture_shutdown_notify(struct notifier_block *unused1,
 {
         if (fullstop)
                 return NOTIFY_DONE;
-        if (signal_pending(current)) {
-                mutex_lock(&fullstop_mutex);
-                if (!ACCESS_ONCE(fullstop))
-                        fullstop = FULLSTOP_SIGNALED;
-                mutex_unlock(&fullstop_mutex);
-        }
+        mutex_lock(&fullstop_mutex);
+        if (!fullstop)
+                fullstop = FULLSTOP_SHUTDOWN;
+        mutex_unlock(&fullstop_mutex);
         return NOTIFY_DONE;
 }
 
@@ -624,7 +622,7 @@ rcu_torture_writer(void *arg)
                 rcu_stutter_wait();
         } while (!kthread_should_stop() && !fullstop);
         VERBOSE_PRINTK_STRING("rcu_torture_writer task stopping");
-        while (!kthread_should_stop() && fullstop != FULLSTOP_SIGNALED)
+        while (!kthread_should_stop() && fullstop != FULLSTOP_SHUTDOWN)
                 schedule_timeout_uninterruptible(1);
         return 0;
 }
@@ -649,7 +647,7 @@ rcu_torture_fakewriter(void *arg)
         } while (!kthread_should_stop() && !fullstop);
 
         VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task stopping");
-        while (!kthread_should_stop() && fullstop != FULLSTOP_SIGNALED)
+        while (!kthread_should_stop() && fullstop != FULLSTOP_SHUTDOWN)
                 schedule_timeout_uninterruptible(1);
         return 0;
 }
@@ -759,7 +757,7 @@ rcu_torture_reader(void *arg)
         VERBOSE_PRINTK_STRING("rcu_torture_reader task stopping");
         if (irqreader && cur_ops->irqcapable)
                 del_timer_sync(&t);
-        while (!kthread_should_stop() && fullstop != FULLSTOP_SIGNALED)
+        while (!kthread_should_stop() && fullstop != FULLSTOP_SHUTDOWN)
                 schedule_timeout_uninterruptible(1);
         return 0;
 }