rcu: Fixes to rcutorture error handling and cleanup

The rcutorture initialization code ignored the error returns from
rcu_torture_onoff_init() and rcu_torture_stall_init().  The rcutorture
cleanup code failed to NULL out a number of pointers.  These bugs will
normally have no effect, but this commit fixes them nevertheless.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

1 files changed, 16 insertions, 3 deletions

diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index a89b381a8c6e..1463a0636443 100644
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -1337,6 +1337,7 @@ static void rcutorture_booster_cleanup(int cpu)
 
         /* This must be outside of the mutex, otherwise deadlock! */
         kthread_stop(t);
+        boost_tasks[cpu] = NULL;
 }
 
 static int rcutorture_booster_init(int cpu)
@@ -1484,13 +1485,15 @@ static void rcu_torture_onoff_cleanup(void)
                 return;
         VERBOSE_PRINTK_STRING("Stopping rcu_torture_onoff task");
         kthread_stop(onoff_task);
+        onoff_task = NULL;
 }
 
 #else /* #ifdef CONFIG_HOTPLUG_CPU */
 
-static void
+static int
 rcu_torture_onoff_init(void)
 {
+        return 0;
 }
 
 static void rcu_torture_onoff_cleanup(void)
@@ -1554,6 +1557,7 @@ static void rcu_torture_stall_cleanup(void)
                 return;
         VERBOSE_PRINTK_STRING("Stopping rcu_torture_stall_task.");
         kthread_stop(stall_task);
+        stall_task = NULL;
 }
 
 static int rcutorture_cpu_notify(struct notifier_block *self,
@@ -1665,6 +1669,7 @@ rcu_torture_cleanup(void)
                 VERBOSE_PRINTK_STRING("Stopping rcu_torture_shutdown task");
                 kthread_stop(shutdown_task);
         }
+        shutdown_task = NULL;
         rcu_torture_onoff_cleanup();
 
         /* Wait for all RCU callbacks to fire.  */
@@ -1897,9 +1902,17 @@ rcu_torture_init(void)
                         goto unwind;
                 }
         }
-        rcu_torture_onoff_init();
+        i = rcu_torture_onoff_init();
+        if (i != 0) {
+                firsterr = i;
+                goto unwind;
+        }
         register_reboot_notifier(&rcutorture_shutdown_nb);
-        rcu_torture_stall_init();
+        i = rcu_torture_stall_init();
+        if (i != 0) {
+                firsterr = i;
+                goto unwind;
+        }
         rcutorture_record_test_transition();
         mutex_unlock(&fullstop_mutex);
         return 0;