rcutorture: Stop generic kthreads in torture_cleanup()

The specific torture modules (like rcutorture) need to call
torture_cleanup() in any case, so this commit makes torture_cleanup()
deal with torture_shutdown_cleanup() and torture_stutter_cleanup() so
that the specific modules don't have to deal with these details.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>

include/linux/torture.h

@@ -75,12 +75,10 @@ int torture_shuffle_init(long shuffint);
 /* Test auto-shutdown handling. */
 void torture_shutdown_absorb(const char *title);
 int torture_shutdown_init(int ssecs, void (*cleanup)(void));
-void torture_shutdown_cleanup(void);
 
 /* Task stuttering, which forces load/no-load transitions. */
 void stutter_wait(const char *title);
 int torture_stutter_init(int s);
-void torture_stutter_cleanup(void);
 
 /* Initialization and cleanup. */
 void torture_init_begin(char *ttype, bool v, int *runnable);

kernel/rcu/rcutorture.c

@@ -53,11 +53,6 @@
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com> and Josh Triplett <josh@freedesktop.org>");
 
-MODULE_ALIAS("rcutorture");
-#ifdef MODULE_PARAM_PREFIX
-#undef MODULE_PARAM_PREFIX
-#endif
-#define MODULE_PARAM_PREFIX "rcutorture."
 
 torture_param(int, fqs_duration, 0,
 	      "Duration of fqs bursts (us), 0 to disable");
@@ -1269,7 +1264,6 @@ rcu_torture_cleanup(void)
 
 	rcu_torture_barrier_cleanup();
 	torture_stop_kthread(rcu_torture_stall, stall_task);
-	torture_stutter_cleanup();
 	torture_stop_kthread(rcu_torture_writer, writer_task);
 
 	if (reader_tasks) {
@@ -1297,7 +1291,6 @@ rcu_torture_cleanup(void)
 		for_each_possible_cpu(i)
 			rcutorture_booster_cleanup(i);
 	}
-	torture_shutdown_cleanup();
 
 	/* Wait for all RCU callbacks to fire.  */
 

kernel/torture.c

@@ -477,20 +477,6 @@ int torture_shutdown_init(int ssecs, void (*cleanup)(void))
 }
 EXPORT_SYMBOL_GPL(torture_shutdown_init);
 
-/*
- * Shut down the shutdown task.  Say what???  Heh!  This can happen if
- * the torture module gets an rmmod before the shutdown time arrives.  ;-)
- */
-void torture_shutdown_cleanup(void)
-{
-	if (shutdown_task != NULL) {
-		VERBOSE_TOROUT_STRING("Stopping torture_shutdown task");
-		kthread_stop(shutdown_task);
-	}
-	shutdown_task = NULL;
-}
-EXPORT_SYMBOL_GPL(torture_shutdown_cleanup);
-
 /*
  * Detect and respond to a system shutdown.
  */
@@ -512,6 +498,20 @@ static struct notifier_block torture_shutdown_nb = {
 	.notifier_call = torture_shutdown_notify,
 };
 
+/*
+ * Shut down the shutdown task.  Say what???  Heh!  This can happen if
+ * the torture module gets an rmmod before the shutdown time arrives.  ;-)
+ */
+static void torture_shutdown_cleanup(void)
+{
+	unregister_reboot_notifier(&torture_shutdown_nb);
+	if (shutdown_task != NULL) {
+		VERBOSE_TOROUT_STRING("Stopping torture_shutdown task");
+		kthread_stop(shutdown_task);
+	}
+	shutdown_task = NULL;
+}
+
 /*
  * Variables for stuttering, which means to periodically pause and
  * restart testing in order to catch bugs that appear when load is
@@ -575,7 +575,7 @@ EXPORT_SYMBOL_GPL(torture_stutter_init);
 /*
  * Cleanup after the torture_stutter kthread.
  */
-void torture_stutter_cleanup(void)
+static void torture_stutter_cleanup(void)
 {
 	if (!stutter_task)
 		return;
@@ -583,7 +583,6 @@ void torture_stutter_cleanup(void)
 	kthread_stop(stutter_task);
 	stutter_task = NULL;
 }
-EXPORT_SYMBOL_GPL(torture_stutter_cleanup);
 
 /*
  * Initialize torture module.  Please note that this is -not- invoked via
@@ -619,7 +618,8 @@ EXPORT_SYMBOL_GPL(torture_init_end);
  * Clean up torture module.  Please note that this is -not- invoked via
  * the usual module_exit() mechanism, but rather by an explicit call from
  * the client torture module.  Returns true if a race with system shutdown
- * is detected.
+ * is detected, otherwise, all kthreads started by functions in this file
+ * will be shut down.
  *
  * This must be called before the caller starts shutting down its own
  * kthreads.
@@ -635,8 +635,9 @@ bool torture_cleanup(void)
 	}
 	ACCESS_ONCE(fullstop) = FULLSTOP_RMMOD;
 	mutex_unlock(&fullstop_mutex);
-	unregister_reboot_notifier(&torture_shutdown_nb);
+	torture_shutdown_cleanup();
 	torture_shuffle_cleanup();
+	torture_stutter_cleanup();
 	torture_onoff_cleanup();
 	return false;
 }