17 files changed, 1433 insertions, 824 deletions

diff --git a/kernel/Makefile b/kernel/Makefile
index bc010ee272b6..5c0e7666811d 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -93,6 +93,7 @@ obj-$(CONFIG_PADATA) += padata.o
 obj-$(CONFIG_CRASH_DUMP) += crash_dump.o
 obj-$(CONFIG_JUMP_LABEL) += jump_label.o
 obj-$(CONFIG_CONTEXT_TRACKING) += context_tracking.o
+obj-$(CONFIG_TORTURE_TEST) += torture.o
 
 $(obj)/configs.o: $(obj)/config_data.h
 
diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c
index d945a949760f..e660964086e2 100644
--- a/kernel/ksysfs.c
+++ b/kernel/ksysfs.c
@@ -19,6 +19,8 @@
 #include <linux/sched.h>
 #include <linux/capability.h>
 
+#include <linux/rcupdate.h>     /* rcu_expedited */
+
 #define KERNEL_ATTR_RO(_name) \
 static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
 
diff --git a/kernel/locking/Makefile b/kernel/locking/Makefile
index baab8e5e7f66..a28ea6d9e6e8 100644
--- a/kernel/locking/Makefile
+++ b/kernel/locking/Makefile
@@ -23,3 +23,4 @@ obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock_debug.o
 obj-$(CONFIG_RWSEM_GENERIC_SPINLOCK) += rwsem-spinlock.o
 obj-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem-xadd.o
 obj-$(CONFIG_PERCPU_RWSEM) += percpu-rwsem.o
+obj-$(CONFIG_LOCK_TORTURE_TEST) += locktorture.o
diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c
new file mode 100644
index 000000000000..f26b1a18e34e
--- /dev/null
+++ b/kernel/locking/locktorture.c
@@ -0,0 +1,452 @@
+/*
+ * Module-based torture test facility for locking
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, you can access it online at
+ * http://www.gnu.org/licenses/gpl-2.0.html.
+ *
+ * Copyright (C) IBM Corporation, 2014
+ *
+ * Author: Paul E. McKenney <paulmck@us.ibm.com>
+ *      Based on kernel/rcu/torture.c.
+ */
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kthread.h>
+#include <linux/err.h>
+#include <linux/spinlock.h>
+#include <linux/smp.h>
+#include <linux/interrupt.h>
+#include <linux/sched.h>
+#include <linux/atomic.h>
+#include <linux/bitops.h>
+#include <linux/completion.h>
+#include <linux/moduleparam.h>
+#include <linux/percpu.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/freezer.h>
+#include <linux/cpu.h>
+#include <linux/delay.h>
+#include <linux/stat.h>
+#include <linux/slab.h>
+#include <linux/trace_clock.h>
+#include <asm/byteorder.h>
+#include <linux/torture.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com>");
+
+torture_param(int, nwriters_stress, -1,
+             "Number of write-locking stress-test threads");
+torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)");
+torture_param(int, onoff_interval, 0,
+             "Time between CPU hotplugs (s), 0=disable");
+torture_param(int, shuffle_interval, 3,
+             "Number of jiffies between shuffles, 0=disable");
+torture_param(int, shutdown_secs, 0, "Shutdown time (j), <= zero to disable.");
+torture_param(int, stat_interval, 60,
+             "Number of seconds between stats printk()s");
+torture_param(int, stutter, 5, "Number of jiffies to run/halt test, 0=disable");
+torture_param(bool, verbose, true,
+             "Enable verbose debugging printk()s");
+
+static char *torture_type = "spin_lock";
+module_param(torture_type, charp, 0444);
+MODULE_PARM_DESC(torture_type,
+                 "Type of lock to torture (spin_lock, spin_lock_irq, ...)");
+
+static atomic_t n_lock_torture_errors;
+
+static struct task_struct *stats_task;
+static struct task_struct **writer_tasks;
+
+static int nrealwriters_stress;
+static bool lock_is_write_held;
+
+struct lock_writer_stress_stats {
+        long n_write_lock_fail;
+        long n_write_lock_acquired;
+};
+static struct lock_writer_stress_stats *lwsa;
+
+#if defined(MODULE) || defined(CONFIG_LOCK_TORTURE_TEST_RUNNABLE)
+#define LOCKTORTURE_RUNNABLE_INIT 1
+#else
+#define LOCKTORTURE_RUNNABLE_INIT 0
+#endif
+int locktorture_runnable = LOCKTORTURE_RUNNABLE_INIT;
+module_param(locktorture_runnable, int, 0444);
+MODULE_PARM_DESC(locktorture_runnable, "Start locktorture at boot");
+
+/* Forward reference. */
+static void lock_torture_cleanup(void);
+
+/*
+ * Operations vector for selecting different types of tests.
+ */
+struct lock_torture_ops {
+        void (*init)(void);
+        int (*writelock)(void);
+        void (*write_delay)(struct torture_random_state *trsp);
+        void (*writeunlock)(void);
+        unsigned long flags;
+        const char *name;
+};
+
+static struct lock_torture_ops *cur_ops;
+
+/*
+ * Definitions for lock torture testing.
+ */
+
+static int torture_lock_busted_write_lock(void)
+{
+        return 0;  /* BUGGY, do not use in real life!!! */
+}
+
+static void torture_lock_busted_write_delay(struct torture_random_state *trsp)
+{
+        const unsigned long longdelay_us = 100;
+
+        /* We want a long delay occasionally to force massive contention.  */
+        if (!(torture_random(trsp) %
+              (nrealwriters_stress * 2000 * longdelay_us)))
+                mdelay(longdelay_us);
+#ifdef CONFIG_PREEMPT
+        if (!(torture_random(trsp) % (nrealwriters_stress * 20000)))
+                preempt_schedule();  /* Allow test to be preempted. */
+#endif
+}
+
+static void torture_lock_busted_write_unlock(void)
+{
+          /* BUGGY, do not use in real life!!! */
+}
+
+static struct lock_torture_ops lock_busted_ops = {
+        .writelock      = torture_lock_busted_write_lock,
+        .write_delay    = torture_lock_busted_write_delay,
+        .writeunlock    = torture_lock_busted_write_unlock,
+        .name           = "lock_busted"
+};
+
+static DEFINE_SPINLOCK(torture_spinlock);
+
+static int torture_spin_lock_write_lock(void) __acquires(torture_spinlock)
+{
+        spin_lock(&torture_spinlock);
+        return 0;
+}
+
+static void torture_spin_lock_write_delay(struct torture_random_state *trsp)
+{
+        const unsigned long shortdelay_us = 2;
+        const unsigned long longdelay_us = 100;
+
+        /* We want a short delay mostly to emulate likely code, and
+         * we want a long delay occasionally to force massive contention.
+         */
+        if (!(torture_random(trsp) %
+              (nrealwriters_stress * 2000 * longdelay_us)))
+                mdelay(longdelay_us);
+        if (!(torture_random(trsp) %
+              (nrealwriters_stress * 2 * shortdelay_us)))
+                udelay(shortdelay_us);
+#ifdef CONFIG_PREEMPT
+        if (!(torture_random(trsp) % (nrealwriters_stress * 20000)))
+                preempt_schedule();  /* Allow test to be preempted. */
+#endif
+}
+
+static void torture_spin_lock_write_unlock(void) __releases(torture_spinlock)
+{
+        spin_unlock(&torture_spinlock);
+}
+
+static struct lock_torture_ops spin_lock_ops = {
+        .writelock      = torture_spin_lock_write_lock,
+        .write_delay    = torture_spin_lock_write_delay,
+        .writeunlock    = torture_spin_lock_write_unlock,
+        .name           = "spin_lock"
+};
+
+static int torture_spin_lock_write_lock_irq(void)
+__acquires(torture_spinlock_irq)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(&torture_spinlock, flags);
+        cur_ops->flags = flags;
+        return 0;
+}
+
+static void torture_lock_spin_write_unlock_irq(void)
+__releases(torture_spinlock)
+{
+        spin_unlock_irqrestore(&torture_spinlock, cur_ops->flags);
+}
+
+static struct lock_torture_ops spin_lock_irq_ops = {
+        .writelock      = torture_spin_lock_write_lock_irq,
+        .write_delay    = torture_spin_lock_write_delay,
+        .writeunlock    = torture_lock_spin_write_unlock_irq,
+        .name           = "spin_lock_irq"
+};
+
+/*
+ * Lock torture writer kthread.  Repeatedly acquires and releases
+ * the lock, checking for duplicate acquisitions.
+ */
+static int lock_torture_writer(void *arg)
+{
+        struct lock_writer_stress_stats *lwsp = arg;
+        static DEFINE_TORTURE_RANDOM(rand);
+
+        VERBOSE_TOROUT_STRING("lock_torture_writer task started");
+        set_user_nice(current, 19);
+
+        do {
+                schedule_timeout_uninterruptible(1);
+                cur_ops->writelock();
+                if (WARN_ON_ONCE(lock_is_write_held))
+                        lwsp->n_write_lock_fail++;
+                lock_is_write_held = 1;
+                lwsp->n_write_lock_acquired++;
+                cur_ops->write_delay(&rand);
+                lock_is_write_held = 0;
+                cur_ops->writeunlock();
+                stutter_wait("lock_torture_writer");
+        } while (!torture_must_stop());
+        torture_kthread_stopping("lock_torture_writer");
+        return 0;
+}
+
+/*
+ * Create an lock-torture-statistics message in the specified buffer.
+ */
+static void lock_torture_printk(char *page)
+{
+        bool fail = 0;
+        int i;
+        long max = 0;
+        long min = lwsa[0].n_write_lock_acquired;
+        long long sum = 0;
+
+        for (i = 0; i < nrealwriters_stress; i++) {
+                if (lwsa[i].n_write_lock_fail)
+                        fail = true;
+                sum += lwsa[i].n_write_lock_acquired;
+                if (max < lwsa[i].n_write_lock_fail)
+                        max = lwsa[i].n_write_lock_fail;
+                if (min > lwsa[i].n_write_lock_fail)
+                        min = lwsa[i].n_write_lock_fail;
+        }
+        page += sprintf(page, "%s%s ", torture_type, TORTURE_FLAG);
+        page += sprintf(page,
+                        "Writes:  Total: %lld  Max/Min: %ld/%ld %s  Fail: %d %s\n",
+                        sum, max, min, max / 2 > min ? "???" : "",
+                        fail, fail ? "!!!" : "");
+        if (fail)
+                atomic_inc(&n_lock_torture_errors);
+}
+
+/*
+ * Print torture statistics.  Caller must ensure that there is only one
+ * call to this function at a given time!!!  This is normally accomplished
+ * by relying on the module system to only have one copy of the module
+ * loaded, and then by giving the lock_torture_stats kthread full control
+ * (or the init/cleanup functions when lock_torture_stats thread is not
+ * running).
+ */
+static void lock_torture_stats_print(void)
+{
+        int size = nrealwriters_stress * 200 + 8192;
+        char *buf;
+
+        buf = kmalloc(size, GFP_KERNEL);
+        if (!buf) {
+                pr_err("lock_torture_stats_print: Out of memory, need: %d",
+                       size);
+                return;
+        }
+        lock_torture_printk(buf);
+        pr_alert("%s", buf);
+        kfree(buf);
+}
+
+/*
+ * Periodically prints torture statistics, if periodic statistics printing
+ * was specified via the stat_interval module parameter.
+ *
+ * No need to worry about fullstop here, since this one doesn't reference
+ * volatile state or register callbacks.
+ */
+static int lock_torture_stats(void *arg)
+{
+        VERBOSE_TOROUT_STRING("lock_torture_stats task started");
+        do {
+                schedule_timeout_interruptible(stat_interval * HZ);
+                lock_torture_stats_print();
+                torture_shutdown_absorb("lock_torture_stats");
+        } while (!torture_must_stop());
+        torture_kthread_stopping("lock_torture_stats");
+        return 0;
+}
+
+static inline void
+lock_torture_print_module_parms(struct lock_torture_ops *cur_ops,
+                                const char *tag)
+{
+        pr_alert("%s" TORTURE_FLAG
+                 "--- %s: nwriters_stress=%d stat_interval=%d verbose=%d shuffle_interval=%d stutter=%d shutdown_secs=%d onoff_interval=%d onoff_holdoff=%d\n",
+                 torture_type, tag, nrealwriters_stress, stat_interval, verbose,
+                 shuffle_interval, stutter, shutdown_secs,
+                 onoff_interval, onoff_holdoff);
+}
+
+static void lock_torture_cleanup(void)
+{
+        int i;
+
+        if (torture_cleanup())
+                return;
+
+        if (writer_tasks) {
+                for (i = 0; i < nrealwriters_stress; i++)
+                        torture_stop_kthread(lock_torture_writer,
+                                             writer_tasks[i]);
+                kfree(writer_tasks);
+                writer_tasks = NULL;
+        }
+
+        torture_stop_kthread(lock_torture_stats, stats_task);
+        lock_torture_stats_print();  /* -After- the stats thread is stopped! */
+
+        if (atomic_read(&n_lock_torture_errors))
+                lock_torture_print_module_parms(cur_ops,
+                                                "End of test: FAILURE");
+        else if (torture_onoff_failures())
+                lock_torture_print_module_parms(cur_ops,
+                                                "End of test: LOCK_HOTPLUG");
+        else
+                lock_torture_print_module_parms(cur_ops,
+                                                "End of test: SUCCESS");
+}
+
+static int __init lock_torture_init(void)
+{
+        int i;
+        int firsterr = 0;
+        static struct lock_torture_ops *torture_ops[] = {
+                &lock_busted_ops, &spin_lock_ops, &spin_lock_irq_ops,
+        };
+
+        torture_init_begin(torture_type, verbose, &locktorture_runnable);
+
+        /* Process args and tell the world that the torturer is on the job. */
+        for (i = 0; i < ARRAY_SIZE(torture_ops); i++) {
+                cur_ops = torture_ops[i];
+                if (strcmp(torture_type, cur_ops->name) == 0)
+                        break;
+        }
+        if (i == ARRAY_SIZE(torture_ops)) {
+                pr_alert("lock-torture: invalid torture type: \"%s\"\n",
+                         torture_type);
+                pr_alert("lock-torture types:");
+                for (i = 0; i < ARRAY_SIZE(torture_ops); i++)
+                        pr_alert(" %s", torture_ops[i]->name);
+                pr_alert("\n");
+                torture_init_end();
+                return -EINVAL;
+        }
+        if (cur_ops->init)
+                cur_ops->init(); /* no "goto unwind" prior to this point!!! */
+
+        if (nwriters_stress >= 0)
+                nrealwriters_stress = nwriters_stress;
+        else
+                nrealwriters_stress = 2 * num_online_cpus();
+        lock_torture_print_module_parms(cur_ops, "Start of test");
+
+        /* Initialize the statistics so that each run gets its own numbers. */
+
+        lock_is_write_held = 0;
+        lwsa = kmalloc(sizeof(*lwsa) * nrealwriters_stress, GFP_KERNEL);
+        if (lwsa == NULL) {
+                VERBOSE_TOROUT_STRING("lwsa: Out of memory");
+                firsterr = -ENOMEM;
+                goto unwind;
+        }
+        for (i = 0; i < nrealwriters_stress; i++) {
+                lwsa[i].n_write_lock_fail = 0;
+                lwsa[i].n_write_lock_acquired = 0;
+        }
+
+        /* Start up the kthreads. */
+
+        if (onoff_interval > 0) {
+                firsterr = torture_onoff_init(onoff_holdoff * HZ,
+                                              onoff_interval * HZ);
+                if (firsterr)
+                        goto unwind;
+        }
+        if (shuffle_interval > 0) {
+                firsterr = torture_shuffle_init(shuffle_interval);
+                if (firsterr)
+                        goto unwind;
+        }
+        if (shutdown_secs > 0) {
+                firsterr = torture_shutdown_init(shutdown_secs,
+                                                 lock_torture_cleanup);
+                if (firsterr)
+                        goto unwind;
+        }
+        if (stutter > 0) {
+                firsterr = torture_stutter_init(stutter);
+                if (firsterr)
+                        goto unwind;
+        }
+
+        writer_tasks = kzalloc(nrealwriters_stress * sizeof(writer_tasks[0]),
+                               GFP_KERNEL);
+        if (writer_tasks == NULL) {
+                VERBOSE_TOROUT_ERRSTRING("writer_tasks: Out of memory");
+                firsterr = -ENOMEM;
+                goto unwind;
+        }
+        for (i = 0; i < nrealwriters_stress; i++) {
+                firsterr = torture_create_kthread(lock_torture_writer, &lwsa[i],
+                                                  writer_tasks[i]);
+                if (firsterr)
+                        goto unwind;
+        }
+        if (stat_interval > 0) {
+                firsterr = torture_create_kthread(lock_torture_stats, NULL,
+                                                  stats_task);
+                if (firsterr)
+                        goto unwind;
+        }
+        torture_init_end();
+        return 0;
+
+unwind:
+        torture_init_end();
+        lock_torture_cleanup();
+        return firsterr;
+}
+
+module_init(lock_torture_init);
+module_exit(lock_torture_cleanup);
diff --git a/kernel/notifier.c b/kernel/notifier.c
index 2d5cc4ccff7f..db4c8b08a50c 100644
--- a/kernel/notifier.c
+++ b/kernel/notifier.c
@@ -309,7 +309,7 @@ int __blocking_notifier_call_chain(struct blocking_notifier_head *nh,
          * racy then it does not matter what the result of the test
          * is, we re-check the list after having taken the lock anyway:
          */
-        if (rcu_dereference_raw(nh->head)) {
+        if (rcu_access_pointer(nh->head)) {
                 down_read(&nh->rwsem);
                 ret = notifier_call_chain(&nh->head, val, v, nr_to_call,
                                         nr_calls);
diff --git a/kernel/rcu/Makefile b/kernel/rcu/Makefile
index 01e9ec37a3e3..807ccfbf69b3 100644
--- a/kernel/rcu/Makefile
+++ b/kernel/rcu/Makefile
@@ -1,5 +1,5 @@
 obj-y += update.o srcu.o
-obj-$(CONFIG_RCU_TORTURE_TEST) += torture.o
+obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o
 obj-$(CONFIG_TREE_RCU) += tree.o
 obj-$(CONFIG_TREE_PREEMPT_RCU) += tree.o
 obj-$(CONFIG_TREE_RCU_TRACE) += tree_trace.o
diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h
index 79c3877e9c5b..bfda2726ca45 100644
--- a/kernel/rcu/rcu.h
+++ b/kernel/rcu/rcu.h
@@ -12,8 +12,8 @@
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ * along with this program; if not, you can access it online at
+ * http://www.gnu.org/licenses/gpl-2.0.html.
  *
  * Copyright IBM Corporation, 2011
  *
@@ -23,6 +23,7 @@
 #ifndef __LINUX_RCU_H
 #define __LINUX_RCU_H
 
+#include <trace/events/rcu.h>
 #ifdef CONFIG_RCU_TRACE
 #define RCU_TRACE(stmt) stmt
 #else /* #ifdef CONFIG_RCU_TRACE */
@@ -116,8 +117,6 @@ static inline bool __rcu_reclaim(const char *rn, struct rcu_head *head)
         }
 }
 
-extern int rcu_expedited;
-
 #ifdef CONFIG_RCU_STALL_COMMON
 
 extern int rcu_cpu_stall_suppress;
diff --git a/kernel/rcu/torture.c b/kernel/rcu/rcutorture.c
index 732f8ae3086a..f59d48597dde 100644
--- a/kernel/rcu/torture.c
+++ b/kernel/rcu/rcutorture.c
@@ -12,8 +12,8 @@
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ * along with this program; if not, you can access it online at
+ * http://www.gnu.org/licenses/gpl-2.0.html.
  *
  * Copyright (C) IBM Corporation, 2005, 2006
  *
@@ -48,110 +48,58 @@
 #include <linux/slab.h>
 #include <linux/trace_clock.h>
 #include <asm/byteorder.h>
+#include <linux/torture.h>
 
 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."
-
-static int fqs_duration;
-module_param(fqs_duration, int, 0444);
-MODULE_PARM_DESC(fqs_duration, "Duration of fqs bursts (us), 0 to disable");
-static int fqs_holdoff;
-module_param(fqs_holdoff, int, 0444);
-MODULE_PARM_DESC(fqs_holdoff, "Holdoff time within fqs bursts (us)");
-static int fqs_stutter = 3;
-module_param(fqs_stutter, int, 0444);
-MODULE_PARM_DESC(fqs_stutter, "Wait time between fqs bursts (s)");
-static bool gp_exp;
-module_param(gp_exp, bool, 0444);
-MODULE_PARM_DESC(gp_exp, "Use expedited GP wait primitives");
-static bool gp_normal;
-module_param(gp_normal, bool, 0444);
-MODULE_PARM_DESC(gp_normal, "Use normal (non-expedited) GP wait primitives");
-static int irqreader = 1;
-module_param(irqreader, int, 0444);
-MODULE_PARM_DESC(irqreader, "Allow RCU readers from irq handlers");
-static int n_barrier_cbs;
-module_param(n_barrier_cbs, int, 0444);
-MODULE_PARM_DESC(n_barrier_cbs, "# of callbacks/kthreads for barrier testing");
-static int nfakewriters = 4;
-module_param(nfakewriters, int, 0444);
-MODULE_PARM_DESC(nfakewriters, "Number of RCU fake writer threads");
-static int nreaders = -1;
-module_param(nreaders, int, 0444);
-MODULE_PARM_DESC(nreaders, "Number of RCU reader threads");
-static int object_debug;
-module_param(object_debug, int, 0444);
-MODULE_PARM_DESC(object_debug, "Enable debug-object double call_rcu() testing");
-static int onoff_holdoff;
-module_param(onoff_holdoff, int, 0444);
-MODULE_PARM_DESC(onoff_holdoff, "Time after boot before CPU hotplugs (s)");
-static int onoff_interval;
-module_param(onoff_interval, int, 0444);
-MODULE_PARM_DESC(onoff_interval, "Time between CPU hotplugs (s), 0=disable");
-static int shuffle_interval = 3;
-module_param(shuffle_interval, int, 0444);
-MODULE_PARM_DESC(shuffle_interval, "Number of seconds between shuffles");
-static int shutdown_secs;
-module_param(shutdown_secs, int, 0444);
-MODULE_PARM_DESC(shutdown_secs, "Shutdown time (s), <= zero to disable.");
-static int stall_cpu;
-module_param(stall_cpu, int, 0444);
-MODULE_PARM_DESC(stall_cpu, "Stall duration (s), zero to disable.");
-static int stall_cpu_holdoff = 10;
-module_param(stall_cpu_holdoff, int, 0444);
-MODULE_PARM_DESC(stall_cpu_holdoff, "Time to wait before starting stall (s).");
-static int stat_interval = 60;
-module_param(stat_interval, int, 0644);
-MODULE_PARM_DESC(stat_interval, "Number of seconds between stats printk()s");
-static int stutter = 5;
-module_param(stutter, int, 0444);
-MODULE_PARM_DESC(stutter, "Number of seconds to run/halt test");
-static int test_boost = 1;
-module_param(test_boost, int, 0444);
-MODULE_PARM_DESC(test_boost, "Test RCU prio boost: 0=no, 1=maybe, 2=yes.");
-static int test_boost_duration = 4;
-module_param(test_boost_duration, int, 0444);
-MODULE_PARM_DESC(test_boost_duration, "Duration of each boost test, seconds.");
-static int test_boost_interval = 7;
-module_param(test_boost_interval, int, 0444);
-MODULE_PARM_DESC(test_boost_interval, "Interval between boost tests, seconds.");
-static bool test_no_idle_hz = true;
-module_param(test_no_idle_hz, bool, 0444);
-MODULE_PARM_DESC(test_no_idle_hz, "Test support for tickless idle CPUs");
+
+torture_param(int, fqs_duration, 0,
+              "Duration of fqs bursts (us), 0 to disable");
+torture_param(int, fqs_holdoff, 0, "Holdoff time within fqs bursts (us)");
+torture_param(int, fqs_stutter, 3, "Wait time between fqs bursts (s)");
+torture_param(bool, gp_exp, false, "Use expedited GP wait primitives");
+torture_param(bool, gp_normal, false,
+             "Use normal (non-expedited) GP wait primitives");
+torture_param(int, irqreader, 1, "Allow RCU readers from irq handlers");
+torture_param(int, n_barrier_cbs, 0,
+             "# of callbacks/kthreads for barrier testing");
+torture_param(int, nfakewriters, 4, "Number of RCU fake writer threads");
+torture_param(int, nreaders, -1, "Number of RCU reader threads");
+torture_param(int, object_debug, 0,
+             "Enable debug-object double call_rcu() testing");
+torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)");
+torture_param(int, onoff_interval, 0,
+             "Time between CPU hotplugs (s), 0=disable");
+torture_param(int, shuffle_interval, 3, "Number of seconds between shuffles");
+torture_param(int, shutdown_secs, 0, "Shutdown time (s), <= zero to disable.");
+torture_param(int, stall_cpu, 0, "Stall duration (s), zero to disable.");
+torture_param(int, stall_cpu_holdoff, 10,
+             "Time to wait before starting stall (s).");
+torture_param(int, stat_interval, 60,
+             "Number of seconds between stats printk()s");
+torture_param(int, stutter, 5, "Number of seconds to run/halt test");
+torture_param(int, test_boost, 1, "Test RCU prio boost: 0=no, 1=maybe, 2=yes.");
+torture_param(int, test_boost_duration, 4,
+             "Duration of each boost test, seconds.");
+torture_param(int, test_boost_interval, 7,
+             "Interval between boost tests, seconds.");
+torture_param(bool, test_no_idle_hz, true,
+             "Test support for tickless idle CPUs");
+torture_param(bool, verbose, true,
+             "Enable verbose debugging printk()s");
+
 static char *torture_type = "rcu";
 module_param(torture_type, charp, 0444);
 MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh, ...)");
-static bool verbose;
-module_param(verbose, bool, 0444);
-MODULE_PARM_DESC(verbose, "Enable verbose debugging printk()s");
-
-#define TORTURE_FLAG "-torture:"
-#define PRINTK_STRING(s) \
-        do { pr_alert("%s" TORTURE_FLAG s "\n", torture_type); } while (0)
-#define VERBOSE_PRINTK_STRING(s) \
-        do { if (verbose) pr_alert("%s" TORTURE_FLAG s "\n", torture_type); } while (0)
-#define VERBOSE_PRINTK_ERRSTRING(s) \
-        do { if (verbose) pr_alert("%s" TORTURE_FLAG "!!! " s "\n", torture_type); } while (0)
 
 static int nrealreaders;
 static struct task_struct *writer_task;
 static struct task_struct **fakewriter_tasks;
 static struct task_struct **reader_tasks;
 static struct task_struct *stats_task;
-static struct task_struct *shuffler_task;
-static struct task_struct *stutter_task;
 static struct task_struct *fqs_task;
 static struct task_struct *boost_tasks[NR_CPUS];
-static struct task_struct *shutdown_task;
-#ifdef CONFIG_HOTPLUG_CPU
-static struct task_struct *onoff_task;
-#endif /* #ifdef CONFIG_HOTPLUG_CPU */
 static struct task_struct *stall_task;
 static struct task_struct **barrier_cbs_tasks;
 static struct task_struct *barrier_task;
@@ -170,10 +118,10 @@ static struct rcu_torture __rcu *rcu_torture_current;
 static unsigned long rcu_torture_current_version;
 static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN];
 static DEFINE_SPINLOCK(rcu_torture_lock);
-static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count) =
-        { 0 };
-static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch) =
-        { 0 };
+static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1],
+                      rcu_torture_count) = { 0 };
+static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1],
+                      rcu_torture_batch) = { 0 };
 static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1];
 static atomic_t n_rcu_torture_alloc;
 static atomic_t n_rcu_torture_alloc_fail;
@@ -186,22 +134,9 @@ static long n_rcu_torture_boost_rterror;
 static long n_rcu_torture_boost_failure;
 static long n_rcu_torture_boosts;
 static long n_rcu_torture_timers;
-static long n_offline_attempts;
-static long n_offline_successes;
-static unsigned long sum_offline;
-static int min_offline = -1;
-static int max_offline;
-static long n_online_attempts;
-static long n_online_successes;
-static unsigned long sum_online;
-static int min_online = -1;
-static int max_online;
 static long n_barrier_attempts;
 static long n_barrier_successes;
 static struct list_head rcu_torture_removed;
-static cpumask_var_t shuffle_tmp_mask;
-
-static int stutter_pause_test;
 
 #if defined(MODULE) || defined(CONFIG_RCU_TORTURE_TEST_RUNNABLE)
 #define RCUTORTURE_RUNNABLE_INIT 1
@@ -232,7 +167,6 @@ static u64 notrace rcu_trace_clock_local(void)
 }
 #endif /* #else #ifdef CONFIG_RCU_TRACE */
 
-static unsigned long shutdown_time;     /* jiffies to system shutdown. */
 static unsigned long boost_starttime;   /* jiffies of next boost test start. */
 DEFINE_MUTEX(boost_mutex);              /* protect setting boost_starttime */
                                         /*  and boost task create/destroy. */
@@ -242,51 +176,6 @@ static atomic_t barrier_cbs_invoked;	/* Barrier callbacks invoked. */
 static wait_queue_head_t *barrier_cbs_wq; /* Coordinate barrier testing. */
 static DECLARE_WAIT_QUEUE_HEAD(barrier_wq);
 
-/* Mediate rmmod and system shutdown.  Concurrent rmmod & shutdown illegal! */
-
-#define FULLSTOP_DONTSTOP 0     /* Normal operation. */
-#define FULLSTOP_SHUTDOWN 1     /* System shutdown with rcutorture running. */
-#define FULLSTOP_RMMOD    2     /* Normal rmmod of rcutorture. */
-static int fullstop = FULLSTOP_RMMOD;
-/*
- * Protect fullstop transitions and spawning of kthreads.
- */
-static DEFINE_MUTEX(fullstop_mutex);
-
-/* Forward reference. */
-static void rcu_torture_cleanup(void);
-
-/*
- * Detect and respond to a system shutdown.
- */
-static int
-rcutorture_shutdown_notify(struct notifier_block *unused1,
-                           unsigned long unused2, void *unused3)
-{
-        mutex_lock(&fullstop_mutex);
-        if (fullstop == FULLSTOP_DONTSTOP)
-                fullstop = FULLSTOP_SHUTDOWN;
-        else
-                pr_warn(/* but going down anyway, so... */
-                       "Concurrent 'rmmod rcutorture' and shutdown illegal!\n");
-        mutex_unlock(&fullstop_mutex);
-        return NOTIFY_DONE;
-}
-
-/*
- * Absorb kthreads into a kernel function that won't return, so that
- * they won't ever access module text or data again.
- */
-static void rcutorture_shutdown_absorb(const char *title)
-{
-        if (ACCESS_ONCE(fullstop) == FULLSTOP_SHUTDOWN) {
-                pr_notice(
-                       "rcutorture thread %s parking due to system shutdown\n",
-                       title);
-                schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT);
-        }
-}
-
 /*
  * Allocate an element from the rcu_tortures pool.
  */
@@ -320,44 +209,6 @@ rcu_torture_free(struct rcu_torture *p)
         spin_unlock_bh(&rcu_torture_lock);
 }
 
-struct rcu_random_state {
-        unsigned long rrs_state;
-        long rrs_count;
-};
-
-#define RCU_RANDOM_MULT 39916801  /* prime */
-#define RCU_RANDOM_ADD  479001701 /* prime */
-#define RCU_RANDOM_REFRESH 10000
-
-#define DEFINE_RCU_RANDOM(name) struct rcu_random_state name = { 0, 0 }
-
-/*
- * Crude but fast random-number generator.  Uses a linear congruential
- * generator, with occasional help from cpu_clock().
- */
-static unsigned long
-rcu_random(struct rcu_random_state *rrsp)
-{
-        if (--rrsp->rrs_count < 0) {
-                rrsp->rrs_state += (unsigned long)local_clock();
-                rrsp->rrs_count = RCU_RANDOM_REFRESH;
-        }
-        rrsp->rrs_state = rrsp->rrs_state * RCU_RANDOM_MULT + RCU_RANDOM_ADD;
-        return swahw32(rrsp->rrs_state);
-}
-
-static void
-rcu_stutter_wait(const char *title)
-{
-        while (stutter_pause_test || !rcutorture_runnable) {
-                if (rcutorture_runnable)
-                        schedule_timeout_interruptible(1);
-                else
-                        schedule_timeout_interruptible(round_jiffies_relative(HZ));
-                rcutorture_shutdown_absorb(title);
-        }
-}
-
 /*
  * Operations vector for selecting different types of tests.
  */
@@ -365,7 +216,7 @@ rcu_stutter_wait(const char *title)
 struct rcu_torture_ops {
         void (*init)(void);
         int (*readlock)(void);
-        void (*read_delay)(struct rcu_random_state *rrsp);
+        void (*read_delay)(struct torture_random_state *rrsp);
         void (*readunlock)(int idx);
         int (*completed)(void);
         void (*deferred_free)(struct rcu_torture *p);
@@ -392,7 +243,7 @@ static int rcu_torture_read_lock(void) __acquires(RCU)
         return 0;
 }
 
-static void rcu_read_delay(struct rcu_random_state *rrsp)
+static void rcu_read_delay(struct torture_random_state *rrsp)
 {
         const unsigned long shortdelay_us = 200;
         const unsigned long longdelay_ms = 50;
@@ -401,12 +252,13 @@ static void rcu_read_delay(struct rcu_random_state *rrsp)
          * period, and we want a long delay occasionally to trigger
          * force_quiescent_state. */
 
-        if (!(rcu_random(rrsp) % (nrealreaders * 2000 * longdelay_ms)))
+        if (!(torture_random(rrsp) % (nrealreaders * 2000 * longdelay_ms)))
                 mdelay(longdelay_ms);
-        if (!(rcu_random(rrsp) % (nrealreaders * 2 * shortdelay_us)))
+        if (!(torture_random(rrsp) % (nrealreaders * 2 * shortdelay_us)))
                 udelay(shortdelay_us);
 #ifdef CONFIG_PREEMPT
-        if (!preempt_count() && !(rcu_random(rrsp) % (nrealreaders * 20000)))
+        if (!preempt_count() &&
+            !(torture_random(rrsp) % (nrealreaders * 20000)))
                 preempt_schedule();  /* No QS if preempt_disable() in effect */
 #endif
 }
@@ -427,7 +279,7 @@ rcu_torture_cb(struct rcu_head *p)
         int i;
         struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu);
 
-        if (fullstop != FULLSTOP_DONTSTOP) {
+        if (torture_must_stop_irq()) {
                 /* Test is ending, just drop callbacks on the floor. */
                 /* The next initialization will pick up the pieces. */
                 return;
@@ -520,6 +372,48 @@ static struct rcu_torture_ops rcu_bh_ops = {
 };
 
 /*
+ * Don't even think about trying any of these in real life!!!
+ * The names includes "busted", and they really means it!
+ * The only purpose of these functions is to provide a buggy RCU
+ * implementation to make sure that rcutorture correctly emits
+ * buggy-RCU error messages.
+ */
+static void rcu_busted_torture_deferred_free(struct rcu_torture *p)
+{
+        /* This is a deliberate bug for testing purposes only! */
+        rcu_torture_cb(&p->rtort_rcu);
+}
+
+static void synchronize_rcu_busted(void)
+{
+        /* This is a deliberate bug for testing purposes only! */
+}
+
+static void
+call_rcu_busted(struct rcu_head *head, void (*func)(struct rcu_head *rcu))
+{
+        /* This is a deliberate bug for testing purposes only! */
+        func(head);
+}
+
+static struct rcu_torture_ops rcu_busted_ops = {
+        .init           = rcu_sync_torture_init,
+        .readlock       = rcu_torture_read_lock,
+        .read_delay     = rcu_read_delay,  /* just reuse rcu's version. */
+        .readunlock     = rcu_torture_read_unlock,
+        .completed      = rcu_no_completed,
+        .deferred_free  = rcu_busted_torture_deferred_free,
+        .sync           = synchronize_rcu_busted,
+        .exp_sync       = synchronize_rcu_busted,
+        .call           = call_rcu_busted,
+        .cb_barrier     = NULL,
+        .fqs            = NULL,
+        .stats          = NULL,
+        .irq_capable    = 1,
+        .name           = "rcu_busted"
+};
+
+/*
  * Definitions for srcu torture testing.
  */
 
@@ -530,7 +424,7 @@ static int srcu_torture_read_lock(void) __acquires(&srcu_ctl)
         return srcu_read_lock(&srcu_ctl);
 }
 
-static void srcu_read_delay(struct rcu_random_state *rrsp)
+static void srcu_read_delay(struct torture_random_state *rrsp)
 {
         long delay;
         const long uspertick = 1000000 / HZ;
@@ -538,7 +432,8 @@ static void srcu_read_delay(struct rcu_random_state *rrsp)
 
         /* We want there to be long-running readers, but not all the time. */
 
-        delay = rcu_random(rrsp) % (nrealreaders * 2 * longdelay * uspertick);
+        delay = torture_random(rrsp) %
+                (nrealreaders * 2 * longdelay * uspertick);
         if (!delay)
                 schedule_timeout_interruptible(longdelay);
         else
@@ -677,12 +572,12 @@ static int rcu_torture_boost(void *arg)
         struct rcu_boost_inflight rbi = { .inflight = 0 };
         struct sched_param sp;
 
-        VERBOSE_PRINTK_STRING("rcu_torture_boost started");
+        VERBOSE_TOROUT_STRING("rcu_torture_boost started");
 
         /* Set real-time priority. */
         sp.sched_priority = 1;
         if (sched_setscheduler(current, SCHED_FIFO, &sp) < 0) {
-                VERBOSE_PRINTK_STRING("rcu_torture_boost RT prio failed!");
+                VERBOSE_TOROUT_STRING("rcu_torture_boost RT prio failed!");
                 n_rcu_torture_boost_rterror++;
         }
 
@@ -693,9 +588,8 @@ static int rcu_torture_boost(void *arg)
                 oldstarttime = boost_starttime;
                 while (ULONG_CMP_LT(jiffies, oldstarttime)) {
                         schedule_timeout_interruptible(oldstarttime - jiffies);
-                        rcu_stutter_wait("rcu_torture_boost");
-                        if (kthread_should_stop() ||
-                            fullstop != FULLSTOP_DONTSTOP)
+                        stutter_wait("rcu_torture_boost");
+                        if (torture_must_stop())
                                 goto checkwait;
                 }
 
@@ -710,15 +604,14 @@ static int rcu_torture_boost(void *arg)
                                 call_rcu(&rbi.rcu, rcu_torture_boost_cb);
                                 if (jiffies - call_rcu_time >
                                          test_boost_duration * HZ - HZ / 2) {
-                                        VERBOSE_PRINTK_STRING("rcu_torture_boost boosting failed");
+                                        VERBOSE_TOROUT_STRING("rcu_torture_boost boosting failed");
                                         n_rcu_torture_boost_failure++;
                                 }
                                 call_rcu_time = jiffies;
                         }
                         cond_resched();
-                        rcu_stutter_wait("rcu_torture_boost");
-                        if (kthread_should_stop() ||
-                            fullstop != FULLSTOP_DONTSTOP)
+                        stutter_wait("rcu_torture_boost");
+                        if (torture_must_stop())
                                 goto checkwait;
                 }
 
@@ -742,16 +635,17 @@ static int rcu_torture_boost(void *arg)
                 }
 
                 /* Go do the stutter. */
-checkwait:      rcu_stutter_wait("rcu_torture_boost");
-        } while (!kthread_should_stop() && fullstop  == FULLSTOP_DONTSTOP);
+checkwait:      stutter_wait("rcu_torture_boost");
+        } while (!torture_must_stop());
 
         /* Clean up and exit. */
-        VERBOSE_PRINTK_STRING("rcu_torture_boost task stopping");
-        rcutorture_shutdown_absorb("rcu_torture_boost");
-        while (!kthread_should_stop() || rbi.inflight)
+        while (!kthread_should_stop() || rbi.inflight) {
+                torture_shutdown_absorb("rcu_torture_boost");
                 schedule_timeout_uninterruptible(1);
+        }
         smp_mb(); /* order accesses to ->inflight before stack-frame death. */
         destroy_rcu_head_on_stack(&rbi.rcu);
+        torture_kthread_stopping("rcu_torture_boost");
         return 0;
 }
 
@@ -766,7 +660,7 @@ rcu_torture_fqs(void *arg)
         unsigned long fqs_resume_time;
         int fqs_burst_remaining;
 
-        VERBOSE_PRINTK_STRING("rcu_torture_fqs task started");
+        VERBOSE_TOROUT_STRING("rcu_torture_fqs task started");
         do {
                 fqs_resume_time = jiffies + fqs_stutter * HZ;
                 while (ULONG_CMP_LT(jiffies, fqs_resume_time) &&
@@ -780,12 +674,9 @@ rcu_torture_fqs(void *arg)
                         udelay(fqs_holdoff);
                         fqs_burst_remaining -= fqs_holdoff;
                 }
-                rcu_stutter_wait("rcu_torture_fqs");
-        } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP);
-        VERBOSE_PRINTK_STRING("rcu_torture_fqs task stopping");
-        rcutorture_shutdown_absorb("rcu_torture_fqs");
-        while (!kthread_should_stop())
-                schedule_timeout_uninterruptible(1);
+                stutter_wait("rcu_torture_fqs");
+        } while (!torture_must_stop());
+        torture_kthread_stopping("rcu_torture_fqs");
         return 0;
 }
 
@@ -802,9 +693,9 @@ rcu_torture_writer(void *arg)
         struct rcu_torture *rp;
         struct rcu_torture *rp1;
         struct rcu_torture *old_rp;
-        static DEFINE_RCU_RANDOM(rand);
+        static DEFINE_TORTURE_RANDOM(rand);
 
-        VERBOSE_PRINTK_STRING("rcu_torture_writer task started");
+        VERBOSE_TOROUT_STRING("rcu_torture_writer task started");
         set_user_nice(current, 19);
 
         do {
@@ -813,7 +704,7 @@ rcu_torture_writer(void *arg)
                 if (rp == NULL)
                         continue;
                 rp->rtort_pipe_count = 0;
-                udelay(rcu_random(&rand) & 0x3ff);
+                udelay(torture_random(&rand) & 0x3ff);
                 old_rp = rcu_dereference_check(rcu_torture_current,
                                                current == writer_task);
                 rp->rtort_mbtest = 1;
@@ -826,7 +717,7 @@ rcu_torture_writer(void *arg)
                         atomic_inc(&rcu_torture_wcount[i]);
                         old_rp->rtort_pipe_count++;
                         if (gp_normal == gp_exp)
-                                exp = !!(rcu_random(&rand) & 0x80);
+                                exp = !!(torture_random(&rand) & 0x80);
                         else
                                 exp = gp_exp;
                         if (!exp) {
@@ -852,12 +743,9 @@ rcu_torture_writer(void *arg)
                         }
                 }
                 rcutorture_record_progress(++rcu_torture_current_version);
-                rcu_stutter_wait("rcu_torture_writer");
-        } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP);
-        VERBOSE_PRINTK_STRING("rcu_torture_writer task stopping");
-        rcutorture_shutdown_absorb("rcu_torture_writer");
-        while (!kthread_should_stop())
-                schedule_timeout_uninterruptible(1);
+                stutter_wait("rcu_torture_writer");
+        } while (!torture_must_stop());
+        torture_kthread_stopping("rcu_torture_writer");
         return 0;
 }
 
@@ -868,19 +756,19 @@ rcu_torture_writer(void *arg)
 static int
 rcu_torture_fakewriter(void *arg)
 {
-        DEFINE_RCU_RANDOM(rand);
+        DEFINE_TORTURE_RANDOM(rand);
 
-        VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task started");
+        VERBOSE_TOROUT_STRING("rcu_torture_fakewriter task started");
         set_user_nice(current, 19);
 
         do {
-                schedule_timeout_uninterruptible(1 + rcu_random(&rand)%10);
-                udelay(rcu_random(&rand) & 0x3ff);
+                schedule_timeout_uninterruptible(1 + torture_random(&rand)%10);
+                udelay(torture_random(&rand) & 0x3ff);
                 if (cur_ops->cb_barrier != NULL &&
-                    rcu_random(&rand) % (nfakewriters * 8) == 0) {
+                    torture_random(&rand) % (nfakewriters * 8) == 0) {
                         cur_ops->cb_barrier();
                 } else if (gp_normal == gp_exp) {
-                        if (rcu_random(&rand) & 0x80)
+                        if (torture_random(&rand) & 0x80)
                                 cur_ops->sync();
                         else
                                 cur_ops->exp_sync();
@@ -889,13 +777,10 @@ rcu_torture_fakewriter(void *arg)
                 } else {
                         cur_ops->exp_sync();
                 }
-                rcu_stutter_wait("rcu_torture_fakewriter");
-        } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP);
+                stutter_wait("rcu_torture_fakewriter");
+        } while (!torture_must_stop());
 
-        VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task stopping");
-        rcutorture_shutdown_absorb("rcu_torture_fakewriter");
-        while (!kthread_should_stop())
-                schedule_timeout_uninterruptible(1);
+        torture_kthread_stopping("rcu_torture_fakewriter");
         return 0;
 }
 
@@ -921,7 +806,7 @@ static void rcu_torture_timer(unsigned long unused)
         int idx;
         int completed;
         int completed_end;
-        static DEFINE_RCU_RANDOM(rand);
+        static DEFINE_TORTURE_RANDOM(rand);
         static DEFINE_SPINLOCK(rand_lock);
         struct rcu_torture *p;
         int pipe_count;
@@ -980,13 +865,13 @@ rcu_torture_reader(void *arg)
         int completed;
         int completed_end;
         int idx;
-        DEFINE_RCU_RANDOM(rand);
+        DEFINE_TORTURE_RANDOM(rand);
         struct rcu_torture *p;
         int pipe_count;
         struct timer_list t;
         unsigned long long ts;
 
-        VERBOSE_PRINTK_STRING("rcu_torture_reader task started");
+        VERBOSE_TOROUT_STRING("rcu_torture_reader task started");
         set_user_nice(current, 19);
         if (irqreader && cur_ops->irq_capable)
                 setup_timer_on_stack(&t, rcu_torture_timer, 0);
@@ -1034,14 +919,11 @@ rcu_torture_reader(void *arg)
                 preempt_enable();
                 cur_ops->readunlock(idx);
                 schedule();
-                rcu_stutter_wait("rcu_torture_reader");
-        } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP);
-        VERBOSE_PRINTK_STRING("rcu_torture_reader task stopping");
-        rcutorture_shutdown_absorb("rcu_torture_reader");
+                stutter_wait("rcu_torture_reader");
+        } while (!torture_must_stop());
         if (irqreader && cur_ops->irq_capable)
                 del_timer_sync(&t);
-        while (!kthread_should_stop())
-                schedule_timeout_uninterruptible(1);
+        torture_kthread_stopping("rcu_torture_reader");
         return 0;
 }
 
@@ -1083,13 +965,7 @@ rcu_torture_printk(char *page)
                        n_rcu_torture_boost_failure,
                        n_rcu_torture_boosts,
                        n_rcu_torture_timers);
-        page += sprintf(page,
-                       "onoff: %ld/%ld:%ld/%ld %d,%d:%d,%d %lu:%lu (HZ=%d) ",
-                       n_online_successes, n_online_attempts,
-                       n_offline_successes, n_offline_attempts,
-                       min_online, max_online,
-                       min_offline, max_offline,
-                       sum_online, sum_offline, HZ);
+        page = torture_onoff_stats(page);
         page += sprintf(page, "barrier: %ld/%ld:%ld",
                        n_barrier_successes,
                        n_barrier_attempts,
@@ -1150,123 +1026,17 @@ rcu_torture_stats_print(void)
 /*
  * Periodically prints torture statistics, if periodic statistics printing
  * was specified via the stat_interval module parameter.
- *
- * No need to worry about fullstop here, since this one doesn't reference
- * volatile state or register callbacks.
  */
 static int
 rcu_torture_stats(void *arg)
 {
-        VERBOSE_PRINTK_STRING("rcu_torture_stats task started");
+        VERBOSE_TOROUT_STRING("rcu_torture_stats task started");
         do {
                 schedule_timeout_interruptible(stat_interval * HZ);
                 rcu_torture_stats_print();
-                rcutorture_shutdown_absorb("rcu_torture_stats");
-        } while (!kthread_should_stop());
-        VERBOSE_PRINTK_STRING("rcu_torture_stats task stopping");
-        return 0;
-}
-
-static int rcu_idle_cpu;        /* Force all torture tasks off this CPU */
-
-/* Shuffle tasks such that we allow @rcu_idle_cpu to become idle. A special case
- * is when @rcu_idle_cpu = -1, when we allow the tasks to run on all CPUs.
- */
-static void rcu_torture_shuffle_tasks(void)
-{
-        int i;
-
-        cpumask_setall(shuffle_tmp_mask);
-        get_online_cpus();
-
-        /* No point in shuffling if there is only one online CPU (ex: UP) */
-        if (num_online_cpus() == 1) {
-                put_online_cpus();
-                return;
-        }
-
-        if (rcu_idle_cpu != -1)
-                cpumask_clear_cpu(rcu_idle_cpu, shuffle_tmp_mask);
-
-        set_cpus_allowed_ptr(current, shuffle_tmp_mask);
-
-        if (reader_tasks) {
-                for (i = 0; i < nrealreaders; i++)
-                        if (reader_tasks[i])
-                                set_cpus_allowed_ptr(reader_tasks[i],
-                                                     shuffle_tmp_mask);
-        }
-        if (fakewriter_tasks) {
-                for (i = 0; i < nfakewriters; i++)
-                        if (fakewriter_tasks[i])
-                                set_cpus_allowed_ptr(fakewriter_tasks[i],
-                                                     shuffle_tmp_mask);
-        }
-        if (writer_task)
-                set_cpus_allowed_ptr(writer_task, shuffle_tmp_mask);
-        if (stats_task)
-                set_cpus_allowed_ptr(stats_task, shuffle_tmp_mask);
-        if (stutter_task)
-                set_cpus_allowed_ptr(stutter_task, shuffle_tmp_mask);
-        if (fqs_task)
-                set_cpus_allowed_ptr(fqs_task, shuffle_tmp_mask);
-        if (shutdown_task)
-                set_cpus_allowed_ptr(shutdown_task, shuffle_tmp_mask);
-#ifdef CONFIG_HOTPLUG_CPU
-        if (onoff_task)
-                set_cpus_allowed_ptr(onoff_task, shuffle_tmp_mask);
-#endif /* #ifdef CONFIG_HOTPLUG_CPU */
-        if (stall_task)
-                set_cpus_allowed_ptr(stall_task, shuffle_tmp_mask);
-        if (barrier_cbs_tasks)
-                for (i = 0; i < n_barrier_cbs; i++)
-                        if (barrier_cbs_tasks[i])
-                                set_cpus_allowed_ptr(barrier_cbs_tasks[i],
-                                                     shuffle_tmp_mask);
-        if (barrier_task)
-                set_cpus_allowed_ptr(barrier_task, shuffle_tmp_mask);
-
-        if (rcu_idle_cpu == -1)
-                rcu_idle_cpu = num_online_cpus() - 1;
-        else
-                rcu_idle_cpu--;
-
-        put_online_cpus();
-}
-
-/* Shuffle tasks across CPUs, with the intent of allowing each CPU in the
- * system to become idle at a time and cut off its timer ticks. This is meant
- * to test the support for such tickless idle CPU in RCU.
- */
-static int
-rcu_torture_shuffle(void *arg)
-{
-        VERBOSE_PRINTK_STRING("rcu_torture_shuffle task started");
-        do {
-                schedule_timeout_interruptible(shuffle_interval * HZ);
-                rcu_torture_shuffle_tasks();
-                rcutorture_shutdown_absorb("rcu_torture_shuffle");
-        } while (!kthread_should_stop());
-        VERBOSE_PRINTK_STRING("rcu_torture_shuffle task stopping");
-        return 0;
-}
-
-/* Cause the rcutorture test to "stutter", starting and stopping all
- * threads periodically.
- */
-static int
-rcu_torture_stutter(void *arg)
-{
-        VERBOSE_PRINTK_STRING("rcu_torture_stutter task started");
-        do {
-                schedule_timeout_interruptible(stutter * HZ);
-                stutter_pause_test = 1;
-                if (!kthread_should_stop())
-                        schedule_timeout_interruptible(stutter * HZ);
-                stutter_pause_test = 0;
-                rcutorture_shutdown_absorb("rcu_torture_stutter");
-        } while (!kthread_should_stop());
-        VERBOSE_PRINTK_STRING("rcu_torture_stutter task stopping");
+                torture_shutdown_absorb("rcu_torture_stats");
+        } while (!torture_must_stop());
+        torture_kthread_stopping("rcu_torture_stats");
         return 0;
 }
 
@@ -1293,10 +1063,6 @@ rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag)
                  onoff_interval, onoff_holdoff);
 }
 
-static struct notifier_block rcutorture_shutdown_nb = {
-        .notifier_call = rcutorture_shutdown_notify,
-};
-
 static void rcutorture_booster_cleanup(int cpu)
 {
         struct task_struct *t;
@@ -1304,14 +1070,12 @@ static void rcutorture_booster_cleanup(int cpu)
         if (boost_tasks[cpu] == NULL)
                 return;
         mutex_lock(&boost_mutex);
-        VERBOSE_PRINTK_STRING("Stopping rcu_torture_boost task");
         t = boost_tasks[cpu];
         boost_tasks[cpu] = NULL;
         mutex_unlock(&boost_mutex);
 
         /* This must be outside of the mutex, otherwise deadlock! */
-        kthread_stop(t);
-        boost_tasks[cpu] = NULL;
+        torture_stop_kthread(rcu_torture_boost, t);
 }
 
 static int rcutorture_booster_init(int cpu)
@@ -1323,13 +1087,13 @@ static int rcutorture_booster_init(int cpu)
 
         /* Don't allow time recalculation while creating a new task. */
         mutex_lock(&boost_mutex);
-        VERBOSE_PRINTK_STRING("Creating rcu_torture_boost task");
+        VERBOSE_TOROUT_STRING("Creating rcu_torture_boost task");
         boost_tasks[cpu] = kthread_create_on_node(rcu_torture_boost, NULL,
                                                   cpu_to_node(cpu),
                                                   "rcu_torture_boost");
         if (IS_ERR(boost_tasks[cpu])) {
                 retval = PTR_ERR(boost_tasks[cpu]);
-                VERBOSE_PRINTK_STRING("rcu_torture_boost task create failed");
+                VERBOSE_TOROUT_STRING("rcu_torture_boost task create failed");
                 n_rcu_torture_boost_ktrerror++;
                 boost_tasks[cpu] = NULL;
                 mutex_unlock(&boost_mutex);
@@ -1342,175 +1106,6 @@ static int rcutorture_booster_init(int cpu)
 }
 
 /*
- * Cause the rcutorture test to shutdown the system after the test has
- * run for the time specified by the shutdown_secs module parameter.
- */
-static int
-rcu_torture_shutdown(void *arg)
-{
-        long delta;
-        unsigned long jiffies_snap;
-
-        VERBOSE_PRINTK_STRING("rcu_torture_shutdown task started");
-        jiffies_snap = ACCESS_ONCE(jiffies);
-        while (ULONG_CMP_LT(jiffies_snap, shutdown_time) &&
-               !kthread_should_stop()) {
-                delta = shutdown_time - jiffies_snap;
-                if (verbose)
-                        pr_alert("%s" TORTURE_FLAG
-                                 "rcu_torture_shutdown task: %lu jiffies remaining\n",
-                                 torture_type, delta);
-                schedule_timeout_interruptible(delta);
-                jiffies_snap = ACCESS_ONCE(jiffies);
-        }
-        if (kthread_should_stop()) {
-                VERBOSE_PRINTK_STRING("rcu_torture_shutdown task stopping");
-                return 0;
-        }
-
-        /* OK, shut down the system. */
-
-        VERBOSE_PRINTK_STRING("rcu_torture_shutdown task shutting down system");
-        shutdown_task = NULL;   /* Avoid self-kill deadlock. */
-        rcu_torture_cleanup();  /* Get the success/failure message. */
-        kernel_power_off();     /* Shut down the system. */
-        return 0;
-}
-
-#ifdef CONFIG_HOTPLUG_CPU
-
-/*
- * Execute random CPU-hotplug operations at the interval specified
- * by the onoff_interval.
- */
-static int
-rcu_torture_onoff(void *arg)
-{
-        int cpu;
-        unsigned long delta;
-        int maxcpu = -1;
-        DEFINE_RCU_RANDOM(rand);
-        int ret;
-        unsigned long starttime;
-
-        VERBOSE_PRINTK_STRING("rcu_torture_onoff task started");
-        for_each_online_cpu(cpu)
-                maxcpu = cpu;
-        WARN_ON(maxcpu < 0);
-        if (onoff_holdoff > 0) {
-                VERBOSE_PRINTK_STRING("rcu_torture_onoff begin holdoff");
-                schedule_timeout_interruptible(onoff_holdoff * HZ);
-                VERBOSE_PRINTK_STRING("rcu_torture_onoff end holdoff");
-        }
-        while (!kthread_should_stop()) {
-                cpu = (rcu_random(&rand) >> 4) % (maxcpu + 1);
-                if (cpu_online(cpu) && cpu_is_hotpluggable(cpu)) {
-                        if (verbose)
-                                pr_alert("%s" TORTURE_FLAG
-                                         "rcu_torture_onoff task: offlining %d\n",
-                                         torture_type, cpu);
-                        starttime = jiffies;
-                        n_offline_attempts++;
-                        ret = cpu_down(cpu);
-                        if (ret) {
-                                if (verbose)
-                                        pr_alert("%s" TORTURE_FLAG
-                                                 "rcu_torture_onoff task: offline %d failed: errno %d\n",
-                                                 torture_type, cpu, ret);
-                        } else {
-                                if (verbose)
-                                        pr_alert("%s" TORTURE_FLAG
-                                                 "rcu_torture_onoff task: offlined %d\n",
-                                                 torture_type, cpu);
-                                n_offline_successes++;
-                                delta = jiffies - starttime;
-                                sum_offline += delta;
-                                if (min_offline < 0) {
-                                        min_offline = delta;
-                                        max_offline = delta;
-                                }
-                                if (min_offline > delta)
-                                        min_offline = delta;
-                                if (max_offline < delta)
-                                        max_offline = delta;
-                        }
-                } else if (cpu_is_hotpluggable(cpu)) {
-                        if (verbose)
-                                pr_alert("%s" TORTURE_FLAG
-                                         "rcu_torture_onoff task: onlining %d\n",
-                                         torture_type, cpu);
-                        starttime = jiffies;
-                        n_online_attempts++;
-                        ret = cpu_up(cpu);
-                        if (ret) {
-                                if (verbose)
-                                        pr_alert("%s" TORTURE_FLAG
-                                                 "rcu_torture_onoff task: online %d failed: errno %d\n",
-                                                 torture_type, cpu, ret);
-                        } else {
-                                if (verbose)
-                                        pr_alert("%s" TORTURE_FLAG
-                                                 "rcu_torture_onoff task: onlined %d\n",
-                                                 torture_type, cpu);
-                                n_online_successes++;
-                                delta = jiffies - starttime;
-                                sum_online += delta;
-                                if (min_online < 0) {
-                                        min_online = delta;
-                                        max_online = delta;
-                                }
-                                if (min_online > delta)
-                                        min_online = delta;
-                                if (max_online < delta)
-                                        max_online = delta;
-                        }
-                }
-                schedule_timeout_interruptible(onoff_interval * HZ);
-        }
-        VERBOSE_PRINTK_STRING("rcu_torture_onoff task stopping");
-        return 0;
-}
-
-static int
-rcu_torture_onoff_init(void)
-{
-        int ret;
-
-        if (onoff_interval <= 0)
-                return 0;
-        onoff_task = kthread_run(rcu_torture_onoff, NULL, "rcu_torture_onoff");
-        if (IS_ERR(onoff_task)) {
-                ret = PTR_ERR(onoff_task);
-                onoff_task = NULL;
-                return ret;
-        }
-        return 0;
-}
-
-static void rcu_torture_onoff_cleanup(void)
-{
-        if (onoff_task == NULL)
-                return;
-        VERBOSE_PRINTK_STRING("Stopping rcu_torture_onoff task");
-        kthread_stop(onoff_task);
-        onoff_task = NULL;
-}
-
-#else /* #ifdef CONFIG_HOTPLUG_CPU */
-
-static int
-rcu_torture_onoff_init(void)
-{
-        return 0;
-}
-
-static void rcu_torture_onoff_cleanup(void)
-{
-}
-
-#endif /* #else #ifdef CONFIG_HOTPLUG_CPU */
-
-/*
  * CPU-stall kthread.  It waits as specified by stall_cpu_holdoff, then
  * induces a CPU stall for the time specified by stall_cpu.
  */
@@ -1518,11 +1113,11 @@ static int rcu_torture_stall(void *args)
 {
         unsigned long stop_at;
 
-        VERBOSE_PRINTK_STRING("rcu_torture_stall task started");
+        VERBOSE_TOROUT_STRING("rcu_torture_stall task started");
         if (stall_cpu_holdoff > 0) {
-                VERBOSE_PRINTK_STRING("rcu_torture_stall begin holdoff");
+                VERBOSE_TOROUT_STRING("rcu_torture_stall begin holdoff");
                 schedule_timeout_interruptible(stall_cpu_holdoff * HZ);
-                VERBOSE_PRINTK_STRING("rcu_torture_stall end holdoff");
+                VERBOSE_TOROUT_STRING("rcu_torture_stall end holdoff");
         }
         if (!kthread_should_stop()) {
                 stop_at = get_seconds() + stall_cpu;
@@ -1536,7 +1131,7 @@ static int rcu_torture_stall(void *args)
                 rcu_read_unlock();
                 pr_alert("rcu_torture_stall end.\n");
         }
-        rcutorture_shutdown_absorb("rcu_torture_stall");
+        torture_shutdown_absorb("rcu_torture_stall");
         while (!kthread_should_stop())
                 schedule_timeout_interruptible(10 * HZ);
         return 0;
@@ -1545,27 +1140,9 @@ static int rcu_torture_stall(void *args)
 /* Spawn CPU-stall kthread, if stall_cpu specified. */
 static int __init rcu_torture_stall_init(void)
 {
-        int ret;
-
         if (stall_cpu <= 0)
                 return 0;
-        stall_task = kthread_run(rcu_torture_stall, NULL, "rcu_torture_stall");
-        if (IS_ERR(stall_task)) {
-                ret = PTR_ERR(stall_task);
-                stall_task = NULL;
-                return ret;
-        }
-        return 0;
-}
-
-/* Clean up after the CPU-stall kthread, if one was spawned. */
-static void rcu_torture_stall_cleanup(void)
-{
-        if (stall_task == NULL)
-                return;
-        VERBOSE_PRINTK_STRING("Stopping rcu_torture_stall_task.");
-        kthread_stop(stall_task);
-        stall_task = NULL;
+        return torture_create_kthread(rcu_torture_stall, NULL, stall_task);
 }
 
 /* Callback function for RCU barrier testing. */
@@ -1583,28 +1160,24 @@ static int rcu_torture_barrier_cbs(void *arg)
         struct rcu_head rcu;
 
         init_rcu_head_on_stack(&rcu);
-        VERBOSE_PRINTK_STRING("rcu_torture_barrier_cbs task started");
+        VERBOSE_TOROUT_STRING("rcu_torture_barrier_cbs task started");
         set_user_nice(current, 19);
         do {
                 wait_event(barrier_cbs_wq[myid],
                            (newphase =
                             ACCESS_ONCE(barrier_phase)) != lastphase ||
-                           kthread_should_stop() ||
-                           fullstop != FULLSTOP_DONTSTOP);
+                           torture_must_stop());
                 lastphase = newphase;
                 smp_mb(); /* ensure barrier_phase load before ->call(). */
-                if (kthread_should_stop() || fullstop != FULLSTOP_DONTSTOP)
+                if (torture_must_stop())
                         break;
                 cur_ops->call(&rcu, rcu_torture_barrier_cbf);
                 if (atomic_dec_and_test(&barrier_cbs_count))
                         wake_up(&barrier_wq);
-        } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP);
-        VERBOSE_PRINTK_STRING("rcu_torture_barrier_cbs task stopping");
-        rcutorture_shutdown_absorb("rcu_torture_barrier_cbs");
-        while (!kthread_should_stop())
-                schedule_timeout_interruptible(1);
+        } while (!torture_must_stop());
         cur_ops->cb_barrier();
         destroy_rcu_head_on_stack(&rcu);
+        torture_kthread_stopping("rcu_torture_barrier_cbs");
         return 0;
 }
 
@@ -1613,7 +1186,7 @@ static int rcu_torture_barrier(void *arg)
 {
         int i;
 
-        VERBOSE_PRINTK_STRING("rcu_torture_barrier task starting");
+        VERBOSE_TOROUT_STRING("rcu_torture_barrier task starting");
         do {
                 atomic_set(&barrier_cbs_invoked, 0);
                 atomic_set(&barrier_cbs_count, n_barrier_cbs);
@@ -1623,9 +1196,8 @@ static int rcu_torture_barrier(void *arg)
                         wake_up(&barrier_cbs_wq[i]);
                 wait_event(barrier_wq,
                            atomic_read(&barrier_cbs_count) == 0 ||
-                           kthread_should_stop() ||
-                           fullstop != FULLSTOP_DONTSTOP);
-                if (kthread_should_stop() || fullstop != FULLSTOP_DONTSTOP)
+                           torture_must_stop());
+                if (torture_must_stop())
                         break;
                 n_barrier_attempts++;
                 cur_ops->cb_barrier(); /* Implies smp_mb() for wait_event(). */
@@ -1635,11 +1207,8 @@ static int rcu_torture_barrier(void *arg)
                 }
                 n_barrier_successes++;
                 schedule_timeout_interruptible(HZ / 10);
-        } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP);
-        VERBOSE_PRINTK_STRING("rcu_torture_barrier task stopping");
-        rcutorture_shutdown_absorb("rcu_torture_barrier");
-        while (!kthread_should_stop())
-                schedule_timeout_interruptible(1);
+        } while (!torture_must_stop());
+        torture_kthread_stopping("rcu_torture_barrier");
         return 0;
 }
 
@@ -1672,24 +1241,13 @@ static int rcu_torture_barrier_init(void)
                 return -ENOMEM;
         for (i = 0; i < n_barrier_cbs; i++) {
                 init_waitqueue_head(&barrier_cbs_wq[i]);
-                barrier_cbs_tasks[i] = kthread_run(rcu_torture_barrier_cbs,
-                                                   (void *)(long)i,
-                                                   "rcu_torture_barrier_cbs");
-                if (IS_ERR(barrier_cbs_tasks[i])) {
-                        ret = PTR_ERR(barrier_cbs_tasks[i]);
-                        VERBOSE_PRINTK_ERRSTRING("Failed to create rcu_torture_barrier_cbs");
-                        barrier_cbs_tasks[i] = NULL;
+                ret = torture_create_kthread(rcu_torture_barrier_cbs,
+                                             (void *)(long)i,
+                                             barrier_cbs_tasks[i]);
+                if (ret)
                         return ret;
-                }
         }
-        barrier_task = kthread_run(rcu_torture_barrier, NULL,
-                                   "rcu_torture_barrier");
-        if (IS_ERR(barrier_task)) {
-                ret = PTR_ERR(barrier_task);
-                VERBOSE_PRINTK_ERRSTRING("Failed to create rcu_torture_barrier");
-                barrier_task = NULL;
-        }
-        return 0;
+        return torture_create_kthread(rcu_torture_barrier, NULL, barrier_task);
 }
 
 /* Clean up after RCU barrier testing. */
@@ -1697,19 +1255,11 @@ static void rcu_torture_barrier_cleanup(void)
 {
         int i;
 
-        if (barrier_task != NULL) {
-                VERBOSE_PRINTK_STRING("Stopping rcu_torture_barrier task");
-                kthread_stop(barrier_task);
-                barrier_task = NULL;
-        }
+        torture_stop_kthread(rcu_torture_barrier, barrier_task);
         if (barrier_cbs_tasks != NULL) {
-                for (i = 0; i < n_barrier_cbs; i++) {
-                        if (barrier_cbs_tasks[i] != NULL) {
-                                VERBOSE_PRINTK_STRING("Stopping rcu_torture_barrier_cbs task");
-                                kthread_stop(barrier_cbs_tasks[i]);
-                                barrier_cbs_tasks[i] = NULL;
-                        }
-                }
+                for (i = 0; i < n_barrier_cbs; i++)
+                        torture_stop_kthread(rcu_torture_barrier_cbs,
+                                             barrier_cbs_tasks[i]);
                 kfree(barrier_cbs_tasks);
                 barrier_cbs_tasks = NULL;
         }
@@ -1747,90 +1297,42 @@ rcu_torture_cleanup(void)
 {
         int i;
 
-        mutex_lock(&fullstop_mutex);
         rcutorture_record_test_transition();
-        if (fullstop == FULLSTOP_SHUTDOWN) {
-                pr_warn(/* but going down anyway, so... */
-                       "Concurrent 'rmmod rcutorture' and shutdown illegal!\n");
-                mutex_unlock(&fullstop_mutex);
-                schedule_timeout_uninterruptible(10);
+        if (torture_cleanup()) {
                 if (cur_ops->cb_barrier != NULL)
                         cur_ops->cb_barrier();
                 return;
         }
-        fullstop = FULLSTOP_RMMOD;
-        mutex_unlock(&fullstop_mutex);
-        unregister_reboot_notifier(&rcutorture_shutdown_nb);
-        rcu_torture_barrier_cleanup();
-        rcu_torture_stall_cleanup();
-        if (stutter_task) {
-                VERBOSE_PRINTK_STRING("Stopping rcu_torture_stutter task");
-                kthread_stop(stutter_task);
-        }
-        stutter_task = NULL;
-        if (shuffler_task) {
-                VERBOSE_PRINTK_STRING("Stopping rcu_torture_shuffle task");
-                kthread_stop(shuffler_task);
-                free_cpumask_var(shuffle_tmp_mask);
-        }
-        shuffler_task = NULL;
 
-        if (writer_task) {
-                VERBOSE_PRINTK_STRING("Stopping rcu_torture_writer task");
-                kthread_stop(writer_task);
-        }
-        writer_task = NULL;
+        rcu_torture_barrier_cleanup();
+        torture_stop_kthread(rcu_torture_stall, stall_task);
+        torture_stop_kthread(rcu_torture_writer, writer_task);
 
         if (reader_tasks) {
-                for (i = 0; i < nrealreaders; i++) {
-                        if (reader_tasks[i]) {
-                                VERBOSE_PRINTK_STRING(
-                                        "Stopping rcu_torture_reader task");
-                                kthread_stop(reader_tasks[i]);
-                        }
-                        reader_tasks[i] = NULL;
-                }
+                for (i = 0; i < nrealreaders; i++)
+                        torture_stop_kthread(rcu_torture_reader,
+                                             reader_tasks[i]);
                 kfree(reader_tasks);
-                reader_tasks = NULL;
         }
         rcu_torture_current = NULL;
 
         if (fakewriter_tasks) {
                 for (i = 0; i < nfakewriters; i++) {
-                        if (fakewriter_tasks[i]) {
-                                VERBOSE_PRINTK_STRING(
-                                        "Stopping rcu_torture_fakewriter task");
-                                kthread_stop(fakewriter_tasks[i]);
-                        }
-                        fakewriter_tasks[i] = NULL;
+                        torture_stop_kthread(rcu_torture_fakewriter,
+                                             fakewriter_tasks[i]);
                 }
                 kfree(fakewriter_tasks);
                 fakewriter_tasks = NULL;
         }
 
-        if (stats_task) {
-                VERBOSE_PRINTK_STRING("Stopping rcu_torture_stats task");
-                kthread_stop(stats_task);
-        }
-        stats_task = NULL;
-
-        if (fqs_task) {
-                VERBOSE_PRINTK_STRING("Stopping rcu_torture_fqs task");
-                kthread_stop(fqs_task);
-        }
-        fqs_task = NULL;
+        torture_stop_kthread(rcu_torture_stats, stats_task);
+        torture_stop_kthread(rcu_torture_fqs, fqs_task);
         if ((test_boost == 1 && cur_ops->can_boost) ||
             test_boost == 2) {
                 unregister_cpu_notifier(&rcutorture_cpu_nb);
                 for_each_possible_cpu(i)
                         rcutorture_booster_cleanup(i);
         }
-        if (shutdown_task != NULL) {
-                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.  */
 
@@ -1841,8 +1343,7 @@ rcu_torture_cleanup(void)
 
         if (atomic_read(&n_rcu_torture_error) || n_rcu_torture_barrier_error)
                 rcu_torture_print_module_parms(cur_ops, "End of test: FAILURE");
-        else if (n_online_successes != n_online_attempts ||
-                 n_offline_successes != n_offline_attempts)
+        else if (torture_onoff_failures())
                 rcu_torture_print_module_parms(cur_ops,
                                                "End of test: RCU_HOTPLUG");
         else
@@ -1911,12 +1412,11 @@ rcu_torture_init(void)
         int i;
         int cpu;
         int firsterr = 0;
-        int retval;
         static struct rcu_torture_ops *torture_ops[] = {
-                &rcu_ops, &rcu_bh_ops, &srcu_ops, &sched_ops,
+                &rcu_ops, &rcu_bh_ops, &rcu_busted_ops, &srcu_ops, &sched_ops,
         };
 
-        mutex_lock(&fullstop_mutex);
+        torture_init_begin(torture_type, verbose, &rcutorture_runnable);
 
         /* Process args and tell the world that the torturer is on the job. */
         for (i = 0; i < ARRAY_SIZE(torture_ops); i++) {
@@ -1931,7 +1431,7 @@ rcu_torture_init(void)
                 for (i = 0; i < ARRAY_SIZE(torture_ops); i++)
                         pr_alert(" %s", torture_ops[i]->name);
                 pr_alert("\n");
-                mutex_unlock(&fullstop_mutex);
+                torture_init_end();
                 return -EINVAL;
         }
         if (cur_ops->fqs == NULL && fqs_duration != 0) {
@@ -1946,7 +1446,6 @@ rcu_torture_init(void)
         else
                 nrealreaders = 2 * num_online_cpus();
         rcu_torture_print_module_parms(cur_ops, "Start of test");
-        fullstop = FULLSTOP_DONTSTOP;
 
         /* Set up the freelist. */
 
@@ -1982,108 +1481,61 @@ rcu_torture_init(void)
 
         /* Start up the kthreads. */
 
-        VERBOSE_PRINTK_STRING("Creating rcu_torture_writer task");
-        writer_task = kthread_create(rcu_torture_writer, NULL,
-                                     "rcu_torture_writer");
-        if (IS_ERR(writer_task)) {
-                firsterr = PTR_ERR(writer_task);
-                VERBOSE_PRINTK_ERRSTRING("Failed to create writer");
-                writer_task = NULL;
+        firsterr = torture_create_kthread(rcu_torture_writer, NULL,
+                                          writer_task);
+        if (firsterr)
                 goto unwind;
-        }
-        wake_up_process(writer_task);
         fakewriter_tasks = kzalloc(nfakewriters * sizeof(fakewriter_tasks[0]),
                                    GFP_KERNEL);
         if (fakewriter_tasks == NULL) {
-                VERBOSE_PRINTK_ERRSTRING("out of memory");
+                VERBOSE_TOROUT_ERRSTRING("out of memory");
                 firsterr = -ENOMEM;
                 goto unwind;
         }
         for (i = 0; i < nfakewriters; i++) {
-                VERBOSE_PRINTK_STRING("Creating rcu_torture_fakewriter task");
-                fakewriter_tasks[i] = kthread_run(rcu_torture_fakewriter, NULL,
-                                                  "rcu_torture_fakewriter");
-                if (IS_ERR(fakewriter_tasks[i])) {
-                        firsterr = PTR_ERR(fakewriter_tasks[i]);
-                        VERBOSE_PRINTK_ERRSTRING("Failed to create fakewriter");
-                        fakewriter_tasks[i] = NULL;
+                firsterr = torture_create_kthread(rcu_torture_fakewriter,
+                                                  NULL, fakewriter_tasks[i]);
+                if (firsterr)
                         goto unwind;
-                }
         }
         reader_tasks = kzalloc(nrealreaders * sizeof(reader_tasks[0]),
                                GFP_KERNEL);
         if (reader_tasks == NULL) {
-                VERBOSE_PRINTK_ERRSTRING("out of memory");
+                VERBOSE_TOROUT_ERRSTRING("out of memory");
                 firsterr = -ENOMEM;
                 goto unwind;
         }
         for (i = 0; i < nrealreaders; i++) {
-                VERBOSE_PRINTK_STRING("Creating rcu_torture_reader task");
-                reader_tasks[i] = kthread_run(rcu_torture_reader, NULL,
-                                              "rcu_torture_reader");
-                if (IS_ERR(reader_tasks[i])) {
-                        firsterr = PTR_ERR(reader_tasks[i]);
-                        VERBOSE_PRINTK_ERRSTRING("Failed to create reader");
-                        reader_tasks[i] = NULL;
+                firsterr = torture_create_kthread(rcu_torture_reader, NULL,
+                                                  reader_tasks[i]);
+                if (firsterr)
                         goto unwind;
-                }
         }
         if (stat_interval > 0) {
-                VERBOSE_PRINTK_STRING("Creating rcu_torture_stats task");
-                stats_task = kthread_run(rcu_torture_stats, NULL,
-                                        "rcu_torture_stats");
-                if (IS_ERR(stats_task)) {
-                        firsterr = PTR_ERR(stats_task);
-                        VERBOSE_PRINTK_ERRSTRING("Failed to create stats");
-                        stats_task = NULL;
+                firsterr = torture_create_kthread(rcu_torture_stats, NULL,
+                                                  stats_task);
+                if (firsterr)
                         goto unwind;
-                }
         }
         if (test_no_idle_hz) {
-                rcu_idle_cpu = num_online_cpus() - 1;
-
-                if (!alloc_cpumask_var(&shuffle_tmp_mask, GFP_KERNEL)) {
-                        firsterr = -ENOMEM;
-                        VERBOSE_PRINTK_ERRSTRING("Failed to alloc mask");
-                        goto unwind;
-                }
-
-                /* Create the shuffler thread */
-                shuffler_task = kthread_run(rcu_torture_shuffle, NULL,
-                                          "rcu_torture_shuffle");
-                if (IS_ERR(shuffler_task)) {
-                        free_cpumask_var(shuffle_tmp_mask);
-                        firsterr = PTR_ERR(shuffler_task);
-                        VERBOSE_PRINTK_ERRSTRING("Failed to create shuffler");
-                        shuffler_task = NULL;
+                firsterr = torture_shuffle_init(shuffle_interval * HZ);
+                if (firsterr)
                         goto unwind;
-                }
         }
         if (stutter < 0)
                 stutter = 0;
         if (stutter) {
-                /* Create the stutter thread */
-                stutter_task = kthread_run(rcu_torture_stutter, NULL,
-                                          "rcu_torture_stutter");
-                if (IS_ERR(stutter_task)) {
-                        firsterr = PTR_ERR(stutter_task);
-                        VERBOSE_PRINTK_ERRSTRING("Failed to create stutter");
-                        stutter_task = NULL;
+                firsterr = torture_stutter_init(stutter * HZ);
+                if (firsterr)
                         goto unwind;
-                }
         }
         if (fqs_duration < 0)
                 fqs_duration = 0;
         if (fqs_duration) {
-                /* Create the stutter thread */
-                fqs_task = kthread_run(rcu_torture_fqs, NULL,
-                                       "rcu_torture_fqs");
-                if (IS_ERR(fqs_task)) {
-                        firsterr = PTR_ERR(fqs_task);
-                        VERBOSE_PRINTK_ERRSTRING("Failed to create fqs");
-                        fqs_task = NULL;
+                /* Create the fqs thread */
+                torture_create_kthread(rcu_torture_fqs, NULL, fqs_task);
+                if (firsterr)
                         goto unwind;
-                }
         }
         if (test_boost_interval < 1)
                 test_boost_interval = 1;
@@ -2097,49 +1549,31 @@ rcu_torture_init(void)
                 for_each_possible_cpu(i) {
                         if (cpu_is_offline(i))
                                 continue;  /* Heuristic: CPU can go offline. */
-                        retval = rcutorture_booster_init(i);
-                        if (retval < 0) {
-                                firsterr = retval;
+                        firsterr = rcutorture_booster_init(i);
+                        if (firsterr)
                                 goto unwind;
-                        }
                 }
         }
-        if (shutdown_secs > 0) {
-                shutdown_time = jiffies + shutdown_secs * HZ;
-                shutdown_task = kthread_create(rcu_torture_shutdown, NULL,
-                                               "rcu_torture_shutdown");
-                if (IS_ERR(shutdown_task)) {
-                        firsterr = PTR_ERR(shutdown_task);
-                        VERBOSE_PRINTK_ERRSTRING("Failed to create shutdown");
-                        shutdown_task = NULL;
-                        goto unwind;
-                }
-                wake_up_process(shutdown_task);
-        }
-        i = rcu_torture_onoff_init();
-        if (i != 0) {
-                firsterr = i;
+        firsterr = torture_shutdown_init(shutdown_secs, rcu_torture_cleanup);
+        if (firsterr)
                 goto unwind;
-        }
-        register_reboot_notifier(&rcutorture_shutdown_nb);
-        i = rcu_torture_stall_init();
-        if (i != 0) {
-                firsterr = i;
+        firsterr = torture_onoff_init(onoff_holdoff * HZ, onoff_interval * HZ);
+        if (firsterr)
                 goto unwind;
-        }
-        retval = rcu_torture_barrier_init();
-        if (retval != 0) {
-                firsterr = retval;
+        firsterr = rcu_torture_stall_init();
+        if (firsterr)
+                goto unwind;
+        firsterr = rcu_torture_barrier_init();
+        if (firsterr)
                 goto unwind;
-        }
         if (object_debug)
                 rcu_test_debug_objects();
         rcutorture_record_test_transition();
-        mutex_unlock(&fullstop_mutex);
+        torture_init_end();
         return 0;
 
 unwind:
-        mutex_unlock(&fullstop_mutex);
+        torture_init_end();
         rcu_torture_cleanup();
         return firsterr;
 }
diff --git a/kernel/rcu/srcu.c b/kernel/rcu/srcu.c
index 3318d8284384..c639556f3fa0 100644
--- a/kernel/rcu/srcu.c
+++ b/kernel/rcu/srcu.c
@@ -12,8 +12,8 @@
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ * along with this program; if not, you can access it online at
+ * http://www.gnu.org/licenses/gpl-2.0.html.
  *
  * Copyright (C) IBM Corporation, 2006
  * Copyright (C) Fujitsu, 2012
@@ -36,8 +36,6 @@
 #include <linux/delay.h>
 #include <linux/srcu.h>
 
-#include <trace/events/rcu.h>
-
 #include "rcu.h"
 
 /*
@@ -398,7 +396,7 @@ void call_srcu(struct srcu_struct *sp, struct rcu_head *head,
         rcu_batch_queue(&sp->batch_queue, head);
         if (!sp->running) {
                 sp->running = true;
-                schedule_delayed_work(&sp->work, 0);
+                queue_delayed_work(system_power_efficient_wq, &sp->work, 0);
         }
         spin_unlock_irqrestore(&sp->queue_lock, flags);
 }
@@ -674,7 +672,8 @@ static void srcu_reschedule(struct srcu_struct *sp)
         }
 
         if (pending)
-                schedule_delayed_work(&sp->work, SRCU_INTERVAL);
+                queue_delayed_work(system_power_efficient_wq,
+                                   &sp->work, SRCU_INTERVAL);
 }
 
 /*
diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c
index 1254f312d024..d9efcc13008c 100644
--- a/kernel/rcu/tiny.c
+++ b/kernel/rcu/tiny.c
@@ -12,8 +12,8 @@
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ * along with this program; if not, you can access it online at
+ * http://www.gnu.org/licenses/gpl-2.0.html.
  *
  * Copyright IBM Corporation, 2008
  *
@@ -37,10 +37,6 @@
 #include <linux/prefetch.h>
 #include <linux/ftrace_event.h>
 
-#ifdef CONFIG_RCU_TRACE
-#include <trace/events/rcu.h>
-#endif /* #else #ifdef CONFIG_RCU_TRACE */
-
 #include "rcu.h"
 
 /* Forward declarations for tiny_plugin.h. */
diff --git a/kernel/rcu/tiny_plugin.h b/kernel/rcu/tiny_plugin.h
index 280d06cae352..431528520562 100644
--- a/kernel/rcu/tiny_plugin.h
+++ b/kernel/rcu/tiny_plugin.h
@@ -14,8 +14,8 @@
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ * along with this program; if not, you can access it online at
+ * http://www.gnu.org/licenses/gpl-2.0.html.
  *
  * Copyright (c) 2010 Linaro
  *
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index b3d116cd072d..351faba48b91 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -12,8 +12,8 @@
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ * along with this program; if not, you can access it online at
+ * http://www.gnu.org/licenses/gpl-2.0.html.
  *
  * Copyright IBM Corporation, 2008
  *
@@ -58,8 +58,6 @@
 #include <linux/suspend.h>
 
 #include "tree.h"
-#include <trace/events/rcu.h>
-
 #include "rcu.h"
 
 MODULE_ALIAS("rcutree");
@@ -837,7 +835,7 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp,
          * to the next.  Only do this for the primary flavor of RCU.
          */
         if (rdp->rsp == rcu_state &&
-            ULONG_CMP_GE(ACCESS_ONCE(jiffies), rdp->rsp->jiffies_resched)) {
+            ULONG_CMP_GE(jiffies, rdp->rsp->jiffies_resched)) {
                 rdp->rsp->jiffies_resched += 5;
                 resched_cpu(rdp->cpu);
         }
@@ -847,7 +845,7 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp,
 
 static void record_gp_stall_check_time(struct rcu_state *rsp)
 {
-        unsigned long j = ACCESS_ONCE(jiffies);
+        unsigned long j = jiffies;
         unsigned long j1;
 
         rsp->gp_start = j;
@@ -1005,7 +1003,7 @@ static void check_cpu_stall(struct rcu_state *rsp, struct rcu_data *rdp)
 
         if (rcu_cpu_stall_suppress || !rcu_gp_in_progress(rsp))
                 return;
-        j = ACCESS_ONCE(jiffies);
+        j = jiffies;
 
         /*
          * Lots of memory barriers to reject false positives.
@@ -2304,7 +2302,7 @@ static void force_quiescent_state(struct rcu_state *rsp)
                 if (rnp_old != NULL)
                         raw_spin_unlock(&rnp_old->fqslock);
                 if (ret) {
-                        rsp->n_force_qs_lh++;
+                        ACCESS_ONCE(rsp->n_force_qs_lh)++;
                         return;
                 }
                 rnp_old = rnp;
@@ -2316,7 +2314,7 @@ static void force_quiescent_state(struct rcu_state *rsp)
         smp_mb__after_unlock_lock();
         raw_spin_unlock(&rnp_old->fqslock);
         if (ACCESS_ONCE(rsp->gp_flags) & RCU_GP_FLAG_FQS) {
-                rsp->n_force_qs_lh++;
+                ACCESS_ONCE(rsp->n_force_qs_lh)++;
                 raw_spin_unlock_irqrestore(&rnp_old->lock, flags);
                 return;  /* Someone beat us to it. */
         }
@@ -2880,7 +2878,7 @@ static int rcu_pending(int cpu)
  * non-NULL, store an indication of whether all callbacks are lazy.
  * (If there are no callbacks, all of them are deemed to be lazy.)
  */
-static int rcu_cpu_has_callbacks(int cpu, bool *all_lazy)
+static int __maybe_unused rcu_cpu_has_callbacks(int cpu, bool *all_lazy)
 {
         bool al = true;
         bool hc = false;
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index 8c19873f1ac9..75dc3c39a02a 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -13,8 +13,8 @@
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ * along with this program; if not, you can access it online at
+ * http://www.gnu.org/licenses/gpl-2.0.html.
  *
  * Copyright IBM Corporation, 2008
  *
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 6e2ef4b2b920..962d1d589929 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -14,8 +14,8 @@
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ * along with this program; if not, you can access it online at
+ * http://www.gnu.org/licenses/gpl-2.0.html.
  *
  * Copyright Red Hat, 2009
  * Copyright IBM Corporation, 2009
@@ -1586,11 +1586,13 @@ static void rcu_prepare_kthreads(int cpu)
  * Because we not have RCU_FAST_NO_HZ, just check whether this CPU needs
  * any flavor of RCU.
  */
+#ifndef CONFIG_RCU_NOCB_CPU_ALL
 int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies)
 {
         *delta_jiffies = ULONG_MAX;
         return rcu_cpu_has_callbacks(cpu, NULL);
 }
+#endif /* #ifndef CONFIG_RCU_NOCB_CPU_ALL */
 
 /*
  * Because we do not have RCU_FAST_NO_HZ, don't bother cleaning up
@@ -1656,7 +1658,7 @@ extern int tick_nohz_active;
  * only if it has been awhile since the last time we did so.  Afterwards,
  * if there are any callbacks ready for immediate invocation, return true.
  */
-static bool rcu_try_advance_all_cbs(void)
+static bool __maybe_unused rcu_try_advance_all_cbs(void)
 {
         bool cbs_ready = false;
         struct rcu_data *rdp;
@@ -1696,6 +1698,7 @@ static bool rcu_try_advance_all_cbs(void)
  *
  * The caller must have disabled interrupts.
  */
+#ifndef CONFIG_RCU_NOCB_CPU_ALL
 int rcu_needs_cpu(int cpu, unsigned long *dj)
 {
         struct rcu_dynticks *rdtp = &per_cpu(rcu_dynticks, cpu);
@@ -1726,6 +1729,7 @@ int rcu_needs_cpu(int cpu, unsigned long *dj)
         }
         return 0;
 }
+#endif /* #ifndef CONFIG_RCU_NOCB_CPU_ALL */
 
 /*
  * Prepare a CPU for idle from an RCU perspective.  The first major task
@@ -1739,6 +1743,7 @@ int rcu_needs_cpu(int cpu, unsigned long *dj)
  */
 static void rcu_prepare_for_idle(int cpu)
 {
+#ifndef CONFIG_RCU_NOCB_CPU_ALL
         struct rcu_data *rdp;
         struct rcu_dynticks *rdtp = &per_cpu(rcu_dynticks, cpu);
         struct rcu_node *rnp;
@@ -1790,6 +1795,7 @@ static void rcu_prepare_for_idle(int cpu)
                 rcu_accelerate_cbs(rsp, rnp, rdp);
                 raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */
         }
+#endif /* #ifndef CONFIG_RCU_NOCB_CPU_ALL */
 }
 
 /*
@@ -1799,11 +1805,12 @@ static void rcu_prepare_for_idle(int cpu)
  */
 static void rcu_cleanup_after_idle(int cpu)
 {
-
+#ifndef CONFIG_RCU_NOCB_CPU_ALL
         if (rcu_is_nocb_cpu(cpu))
                 return;
         if (rcu_try_advance_all_cbs())
                 invoke_rcu_core();
+#endif /* #ifndef CONFIG_RCU_NOCB_CPU_ALL */
 }
 
 /*
@@ -2101,6 +2108,7 @@ static void rcu_init_one_nocb(struct rcu_node *rnp)
         init_waitqueue_head(&rnp->nocb_gp_wq[1]);
 }
 
+#ifndef CONFIG_RCU_NOCB_CPU_ALL
 /* Is the specified CPU a no-CPUs CPU? */
 bool rcu_is_nocb_cpu(int cpu)
 {
@@ -2108,6 +2116,7 @@ bool rcu_is_nocb_cpu(int cpu)
                 return cpumask_test_cpu(cpu, rcu_nocb_mask);
         return false;
 }
+#endif /* #ifndef CONFIG_RCU_NOCB_CPU_ALL */
 
 /*
  * Enqueue the specified string of rcu_head structures onto the specified
@@ -2893,7 +2902,7 @@ static void rcu_sysidle_init_percpu_data(struct rcu_dynticks *rdtp)
  * CPU unless the grace period has extended for too long.
  *
  * This code relies on the fact that all NO_HZ_FULL CPUs are also
- * CONFIG_RCU_NOCB_CPUs.
+ * CONFIG_RCU_NOCB_CPU CPUs.
  */
 static bool rcu_nohz_full_cpu(struct rcu_state *rsp)
 {
diff --git a/kernel/rcu/tree_trace.c b/kernel/rcu/tree_trace.c
index 4def475336d4..5cdc62e1beeb 100644
--- a/kernel/rcu/tree_trace.c
+++ b/kernel/rcu/tree_trace.c
@@ -12,8 +12,8 @@
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ * along with this program; if not, you can access it online at
+ * http://www.gnu.org/licenses/gpl-2.0.html.
  *
  * Copyright IBM Corporation, 2008
  *
@@ -273,7 +273,7 @@ static void print_one_rcu_state(struct seq_file *m, struct rcu_state *rsp)
         seq_printf(m, "nfqs=%lu/nfqsng=%lu(%lu) fqlh=%lu oqlen=%ld/%ld\n",
                    rsp->n_force_qs, rsp->n_force_qs_ngp,
                    rsp->n_force_qs - rsp->n_force_qs_ngp,
-                   rsp->n_force_qs_lh, rsp->qlen_lazy, rsp->qlen);
+                   ACCESS_ONCE(rsp->n_force_qs_lh), rsp->qlen_lazy, rsp->qlen);
         for (rnp = &rsp->node[0]; rnp - &rsp->node[0] < rcu_num_nodes; rnp++) {
                 if (rnp->level != level) {
                         seq_puts(m, "\n");
diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c
index c54609faf233..4c0a9b0af469 100644
--- a/kernel/rcu/update.c
+++ b/kernel/rcu/update.c
@@ -12,8 +12,8 @@
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ * along with this program; if not, you can access it online at
+ * http://www.gnu.org/licenses/gpl-2.0.html.
  *
  * Copyright IBM Corporation, 2001
  *
@@ -49,7 +49,6 @@
 #include <linux/module.h>
 
 #define CREATE_TRACE_POINTS
-#include <trace/events/rcu.h>
 
 #include "rcu.h"
 
diff --git a/kernel/torture.c b/kernel/torture.c
new file mode 100644
index 000000000000..acc9afc2f26e
--- /dev/null
+++ b/kernel/torture.c
@@ -0,0 +1,719 @@
+/*
+ * Common functions for in-kernel torture tests.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, you can access it online at
+ * http://www.gnu.org/licenses/gpl-2.0.html.
+ *
+ * Copyright (C) IBM Corporation, 2014
+ *
+ * Author: Paul E. McKenney <paulmck@us.ibm.com>
+ *      Based on kernel/rcu/torture.c.
+ */
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kthread.h>
+#include <linux/err.h>
+#include <linux/spinlock.h>
+#include <linux/smp.h>
+#include <linux/interrupt.h>
+#include <linux/sched.h>
+#include <linux/atomic.h>
+#include <linux/bitops.h>
+#include <linux/completion.h>
+#include <linux/moduleparam.h>
+#include <linux/percpu.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/freezer.h>
+#include <linux/cpu.h>
+#include <linux/delay.h>
+#include <linux/stat.h>
+#include <linux/slab.h>
+#include <linux/trace_clock.h>
+#include <asm/byteorder.h>
+#include <linux/torture.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com>");
+
+static char *torture_type;
+static bool verbose;
+
+/* Mediate rmmod and system shutdown.  Concurrent rmmod & shutdown illegal! */
+#define FULLSTOP_DONTSTOP 0     /* Normal operation. */
+#define FULLSTOP_SHUTDOWN 1     /* System shutdown with torture running. */
+#define FULLSTOP_RMMOD    2     /* Normal rmmod of torture. */
+static int fullstop = FULLSTOP_RMMOD;
+static DEFINE_MUTEX(fullstop_mutex);
+static int *torture_runnable;
+
+#ifdef CONFIG_HOTPLUG_CPU
+
+/*
+ * Variables for online-offline handling.  Only present if CPU hotplug
+ * is enabled, otherwise does nothing.
+ */
+
+static struct task_struct *onoff_task;
+static long onoff_holdoff;
+static long onoff_interval;
+static long n_offline_attempts;
+static long n_offline_successes;
+static unsigned long sum_offline;
+static int min_offline = -1;
+static int max_offline;
+static long n_online_attempts;
+static long n_online_successes;
+static unsigned long sum_online;
+static int min_online = -1;
+static int max_online;
+
+/*
+ * Execute random CPU-hotplug operations at the interval specified
+ * by the onoff_interval.
+ */
+static int
+torture_onoff(void *arg)
+{
+        int cpu;
+        unsigned long delta;
+        int maxcpu = -1;
+        DEFINE_TORTURE_RANDOM(rand);
+        int ret;
+        unsigned long starttime;
+
+        VERBOSE_TOROUT_STRING("torture_onoff task started");
+        for_each_online_cpu(cpu)
+                maxcpu = cpu;
+        WARN_ON(maxcpu < 0);
+        if (onoff_holdoff > 0) {
+                VERBOSE_TOROUT_STRING("torture_onoff begin holdoff");
+                schedule_timeout_interruptible(onoff_holdoff);
+                VERBOSE_TOROUT_STRING("torture_onoff end holdoff");
+        }
+        while (!torture_must_stop()) {
+                cpu = (torture_random(&rand) >> 4) % (maxcpu + 1);
+                if (cpu_online(cpu) && cpu_is_hotpluggable(cpu)) {
+                        if (verbose)
+                                pr_alert("%s" TORTURE_FLAG
+                                         "torture_onoff task: offlining %d\n",
+                                         torture_type, cpu);
+                        starttime = jiffies;
+                        n_offline_attempts++;
+                        ret = cpu_down(cpu);
+                        if (ret) {
+                                if (verbose)
+                                        pr_alert("%s" TORTURE_FLAG
+                                                 "torture_onoff task: offline %d failed: errno %d\n",
+                                                 torture_type, cpu, ret);
+                        } else {
+                                if (verbose)
+                                        pr_alert("%s" TORTURE_FLAG
+                                                 "torture_onoff task: offlined %d\n",
+                                                 torture_type, cpu);
+                                n_offline_successes++;
+                                delta = jiffies - starttime;
+                                sum_offline += delta;
+                                if (min_offline < 0) {
+                                        min_offline = delta;
+                                        max_offline = delta;
+                                }
+                                if (min_offline > delta)
+                                        min_offline = delta;
+                                if (max_offline < delta)
+                                        max_offline = delta;
+                        }
+                } else if (cpu_is_hotpluggable(cpu)) {
+                        if (verbose)
+                                pr_alert("%s" TORTURE_FLAG
+                                         "torture_onoff task: onlining %d\n",
+                                         torture_type, cpu);
+                        starttime = jiffies;
+                        n_online_attempts++;
+                        ret = cpu_up(cpu);
+                        if (ret) {
+                                if (verbose)
+                                        pr_alert("%s" TORTURE_FLAG
+                                                 "torture_onoff task: online %d failed: errno %d\n",
+                                                 torture_type, cpu, ret);
+                        } else {
+                                if (verbose)
+                                        pr_alert("%s" TORTURE_FLAG
+                                                 "torture_onoff task: onlined %d\n",
+                                                 torture_type, cpu);
+                                n_online_successes++;
+                                delta = jiffies - starttime;
+                                sum_online += delta;
+                                if (min_online < 0) {
+                                        min_online = delta;
+                                        max_online = delta;
+                                }
+                                if (min_online > delta)
+                                        min_online = delta;
+                                if (max_online < delta)
+                                        max_online = delta;
+                        }
+                }
+                schedule_timeout_interruptible(onoff_interval);
+        }
+        torture_kthread_stopping("torture_onoff");
+        return 0;
+}
+
+#endif /* #ifdef CONFIG_HOTPLUG_CPU */
+
+/*
+ * Initiate online-offline handling.
+ */
+int torture_onoff_init(long ooholdoff, long oointerval)
+{
+        int ret = 0;
+
+#ifdef CONFIG_HOTPLUG_CPU
+        onoff_holdoff = ooholdoff;
+        onoff_interval = oointerval;
+        if (onoff_interval <= 0)
+                return 0;
+        ret = torture_create_kthread(torture_onoff, NULL, onoff_task);
+#endif /* #ifdef CONFIG_HOTPLUG_CPU */
+        return ret;
+}
+EXPORT_SYMBOL_GPL(torture_onoff_init);
+
+/*
+ * Clean up after online/offline testing.
+ */
+static void torture_onoff_cleanup(void)
+{
+#ifdef CONFIG_HOTPLUG_CPU
+        if (onoff_task == NULL)
+                return;
+        VERBOSE_TOROUT_STRING("Stopping torture_onoff task");
+        kthread_stop(onoff_task);
+        onoff_task = NULL;
+#endif /* #ifdef CONFIG_HOTPLUG_CPU */
+}
+EXPORT_SYMBOL_GPL(torture_onoff_cleanup);
+
+/*
+ * Print online/offline testing statistics.
+ */
+char *torture_onoff_stats(char *page)
+{
+#ifdef CONFIG_HOTPLUG_CPU
+        page += sprintf(page,
+                       "onoff: %ld/%ld:%ld/%ld %d,%d:%d,%d %lu:%lu (HZ=%d) ",
+                       n_online_successes, n_online_attempts,
+                       n_offline_successes, n_offline_attempts,
+                       min_online, max_online,
+                       min_offline, max_offline,
+                       sum_online, sum_offline, HZ);
+#endif /* #ifdef CONFIG_HOTPLUG_CPU */
+        return page;
+}
+EXPORT_SYMBOL_GPL(torture_onoff_stats);
+
+/*
+ * Were all the online/offline operations successful?
+ */
+bool torture_onoff_failures(void)
+{
+#ifdef CONFIG_HOTPLUG_CPU
+        return n_online_successes != n_online_attempts ||
+               n_offline_successes != n_offline_attempts;
+#else /* #ifdef CONFIG_HOTPLUG_CPU */
+        return false;
+#endif /* #else #ifdef CONFIG_HOTPLUG_CPU */
+}
+EXPORT_SYMBOL_GPL(torture_onoff_failures);
+
+#define TORTURE_RANDOM_MULT     39916801  /* prime */
+#define TORTURE_RANDOM_ADD      479001701 /* prime */
+#define TORTURE_RANDOM_REFRESH  10000
+
+/*
+ * Crude but fast random-number generator.  Uses a linear congruential
+ * generator, with occasional help from cpu_clock().
+ */
+unsigned long
+torture_random(struct torture_random_state *trsp)
+{
+        if (--trsp->trs_count < 0) {
+                trsp->trs_state += (unsigned long)local_clock();
+                trsp->trs_count = TORTURE_RANDOM_REFRESH;
+        }
+        trsp->trs_state = trsp->trs_state * TORTURE_RANDOM_MULT +
+                TORTURE_RANDOM_ADD;
+        return swahw32(trsp->trs_state);
+}
+EXPORT_SYMBOL_GPL(torture_random);
+
+/*
+ * Variables for shuffling.  The idea is to ensure that each CPU stays
+ * idle for an extended period to test interactions with dyntick idle,
+ * as well as interactions with any per-CPU varibles.
+ */
+struct shuffle_task {
+        struct list_head st_l;
+        struct task_struct *st_t;
+};
+
+static long shuffle_interval;   /* In jiffies. */
+static struct task_struct *shuffler_task;
+static cpumask_var_t shuffle_tmp_mask;
+static int shuffle_idle_cpu;    /* Force all torture tasks off this CPU */
+static struct list_head shuffle_task_list = LIST_HEAD_INIT(shuffle_task_list);
+static DEFINE_MUTEX(shuffle_task_mutex);
+
+/*
+ * Register a task to be shuffled.  If there is no memory, just splat
+ * and don't bother registering.
+ */
+void torture_shuffle_task_register(struct task_struct *tp)
+{
+        struct shuffle_task *stp;
+
+        if (WARN_ON_ONCE(tp == NULL))
+                return;
+        stp = kmalloc(sizeof(*stp), GFP_KERNEL);
+        if (WARN_ON_ONCE(stp == NULL))
+                return;
+        stp->st_t = tp;
+        mutex_lock(&shuffle_task_mutex);
+        list_add(&stp->st_l, &shuffle_task_list);
+        mutex_unlock(&shuffle_task_mutex);
+}
+EXPORT_SYMBOL_GPL(torture_shuffle_task_register);
+
+/*
+ * Unregister all tasks, for example, at the end of the torture run.
+ */
+static void torture_shuffle_task_unregister_all(void)
+{
+        struct shuffle_task *stp;
+        struct shuffle_task *p;
+
+        mutex_lock(&shuffle_task_mutex);
+        list_for_each_entry_safe(stp, p, &shuffle_task_list, st_l) {
+                list_del(&stp->st_l);
+                kfree(stp);
+        }
+        mutex_unlock(&shuffle_task_mutex);
+}
+
+/* Shuffle tasks such that we allow shuffle_idle_cpu to become idle.
+ * A special case is when shuffle_idle_cpu = -1, in which case we allow
+ * the tasks to run on all CPUs.
+ */
+static void torture_shuffle_tasks(void)
+{
+        struct shuffle_task *stp;
+
+        cpumask_setall(shuffle_tmp_mask);
+        get_online_cpus();
+
+        /* No point in shuffling if there is only one online CPU (ex: UP) */
+        if (num_online_cpus() == 1) {
+                put_online_cpus();
+                return;
+        }
+
+        /* Advance to the next CPU.  Upon overflow, don't idle any CPUs. */
+        shuffle_idle_cpu = cpumask_next(shuffle_idle_cpu, shuffle_tmp_mask);
+        if (shuffle_idle_cpu >= nr_cpu_ids)
+                shuffle_idle_cpu = -1;
+        if (shuffle_idle_cpu != -1) {
+                cpumask_clear_cpu(shuffle_idle_cpu, shuffle_tmp_mask);
+                if (cpumask_empty(shuffle_tmp_mask)) {
+                        put_online_cpus();
+                        return;
+                }
+        }
+
+        mutex_lock(&shuffle_task_mutex);
+        list_for_each_entry(stp, &shuffle_task_list, st_l)
+                set_cpus_allowed_ptr(stp->st_t, shuffle_tmp_mask);
+        mutex_unlock(&shuffle_task_mutex);
+
+        put_online_cpus();
+}
+
+/* Shuffle tasks across CPUs, with the intent of allowing each CPU in the
+ * system to become idle at a time and cut off its timer ticks. This is meant
+ * to test the support for such tickless idle CPU in RCU.
+ */
+static int torture_shuffle(void *arg)
+{
+        VERBOSE_TOROUT_STRING("torture_shuffle task started");
+        do {
+                schedule_timeout_interruptible(shuffle_interval);
+                torture_shuffle_tasks();
+                torture_shutdown_absorb("torture_shuffle");
+        } while (!torture_must_stop());
+        torture_kthread_stopping("torture_shuffle");
+        return 0;
+}
+
+/*
+ * Start the shuffler, with shuffint in jiffies.
+ */
+int torture_shuffle_init(long shuffint)
+{
+        shuffle_interval = shuffint;
+
+        shuffle_idle_cpu = -1;
+
+        if (!alloc_cpumask_var(&shuffle_tmp_mask, GFP_KERNEL)) {
+                VERBOSE_TOROUT_ERRSTRING("Failed to alloc mask");
+                return -ENOMEM;
+        }
+
+        /* Create the shuffler thread */
+        return torture_create_kthread(torture_shuffle, NULL, shuffler_task);
+}
+EXPORT_SYMBOL_GPL(torture_shuffle_init);
+
+/*
+ * Stop the shuffling.
+ */
+static void torture_shuffle_cleanup(void)
+{
+        torture_shuffle_task_unregister_all();
+        if (shuffler_task) {
+                VERBOSE_TOROUT_STRING("Stopping torture_shuffle task");
+                kthread_stop(shuffler_task);
+                free_cpumask_var(shuffle_tmp_mask);
+        }
+        shuffler_task = NULL;
+}
+EXPORT_SYMBOL_GPL(torture_shuffle_cleanup);
+
+/*
+ * Variables for auto-shutdown.  This allows "lights out" torture runs
+ * to be fully scripted.
+ */
+static int shutdown_secs;               /* desired test duration in seconds. */
+static struct task_struct *shutdown_task;
+static unsigned long shutdown_time;     /* jiffies to system shutdown. */
+static void (*torture_shutdown_hook)(void);
+
+/*
+ * Absorb kthreads into a kernel function that won't return, so that
+ * they won't ever access module text or data again.
+ */
+void torture_shutdown_absorb(const char *title)
+{
+        while (ACCESS_ONCE(fullstop) == FULLSTOP_SHUTDOWN) {
+                pr_notice("torture thread %s parking due to system shutdown\n",
+                          title);
+                schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT);
+        }
+}
+EXPORT_SYMBOL_GPL(torture_shutdown_absorb);
+
+/*
+ * Cause the torture test to shutdown the system after the test has
+ * run for the time specified by the shutdown_secs parameter.
+ */
+static int torture_shutdown(void *arg)
+{
+        long delta;
+        unsigned long jiffies_snap;
+
+        VERBOSE_TOROUT_STRING("torture_shutdown task started");
+        jiffies_snap = jiffies;
+        while (ULONG_CMP_LT(jiffies_snap, shutdown_time) &&
+               !torture_must_stop()) {
+                delta = shutdown_time - jiffies_snap;
+                if (verbose)
+                        pr_alert("%s" TORTURE_FLAG
+                                 "torture_shutdown task: %lu jiffies remaining\n",
+                                 torture_type, delta);
+                schedule_timeout_interruptible(delta);
+                jiffies_snap = jiffies;
+        }
+        if (torture_must_stop()) {
+                torture_kthread_stopping("torture_shutdown");
+                return 0;
+        }
+
+        /* OK, shut down the system. */
+
+        VERBOSE_TOROUT_STRING("torture_shutdown task shutting down system");
+        shutdown_task = NULL;   /* Avoid self-kill deadlock. */
+        if (torture_shutdown_hook)
+                torture_shutdown_hook();
+        else
+                VERBOSE_TOROUT_STRING("No torture_shutdown_hook(), skipping.");
+        kernel_power_off();     /* Shut down the system. */
+        return 0;
+}
+
+/*
+ * Start up the shutdown task.
+ */
+int torture_shutdown_init(int ssecs, void (*cleanup)(void))
+{
+        int ret = 0;
+
+        shutdown_secs = ssecs;
+        torture_shutdown_hook = cleanup;
+        if (shutdown_secs > 0) {
+                shutdown_time = jiffies + shutdown_secs * HZ;
+                ret = torture_create_kthread(torture_shutdown, NULL,
+                                             shutdown_task);
+        }
+        return ret;
+}
+EXPORT_SYMBOL_GPL(torture_shutdown_init);
+
+/*
+ * Detect and respond to a system shutdown.
+ */
+static int torture_shutdown_notify(struct notifier_block *unused1,
+                                   unsigned long unused2, void *unused3)
+{
+        mutex_lock(&fullstop_mutex);
+        if (ACCESS_ONCE(fullstop) == FULLSTOP_DONTSTOP) {
+                VERBOSE_TOROUT_STRING("Unscheduled system shutdown detected");
+                ACCESS_ONCE(fullstop) = FULLSTOP_SHUTDOWN;
+        } else {
+                pr_warn("Concurrent rmmod and shutdown illegal!\n");
+        }
+        mutex_unlock(&fullstop_mutex);
+        return NOTIFY_DONE;
+}
+
+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
+ * suddenly applied to or removed from the system.
+ */
+static struct task_struct *stutter_task;
+static int stutter_pause_test;
+static int stutter;
+
+/*
+ * Block until the stutter interval ends.  This must be called periodically
+ * by all running kthreads that need to be subject to stuttering.
+ */
+void stutter_wait(const char *title)
+{
+        while (ACCESS_ONCE(stutter_pause_test) ||
+               (torture_runnable && !ACCESS_ONCE(*torture_runnable))) {
+                if (stutter_pause_test)
+                        schedule_timeout_interruptible(1);
+                else
+                        schedule_timeout_interruptible(round_jiffies_relative(HZ));
+                torture_shutdown_absorb(title);
+        }
+}
+EXPORT_SYMBOL_GPL(stutter_wait);
+
+/*
+ * Cause the torture test to "stutter", starting and stopping all
+ * threads periodically.
+ */
+static int torture_stutter(void *arg)
+{
+        VERBOSE_TOROUT_STRING("torture_stutter task started");
+        do {
+                if (!torture_must_stop()) {
+                        schedule_timeout_interruptible(stutter);
+                        ACCESS_ONCE(stutter_pause_test) = 1;
+                }
+                if (!torture_must_stop())
+                        schedule_timeout_interruptible(stutter);
+                ACCESS_ONCE(stutter_pause_test) = 0;
+                torture_shutdown_absorb("torture_stutter");
+        } while (!torture_must_stop());
+        torture_kthread_stopping("torture_stutter");
+        return 0;
+}
+
+/*
+ * Initialize and kick off the torture_stutter kthread.
+ */
+int torture_stutter_init(int s)
+{
+        int ret;
+
+        stutter = s;
+        ret = torture_create_kthread(torture_stutter, NULL, stutter_task);
+        return ret;
+}
+EXPORT_SYMBOL_GPL(torture_stutter_init);
+
+/*
+ * Cleanup after the torture_stutter kthread.
+ */
+static void torture_stutter_cleanup(void)
+{
+        if (!stutter_task)
+                return;
+        VERBOSE_TOROUT_STRING("Stopping torture_stutter task");
+        kthread_stop(stutter_task);
+        stutter_task = NULL;
+}
+
+/*
+ * Initialize torture module.  Please note that this is -not- invoked via
+ * the usual module_init() mechanism, but rather by an explicit call from
+ * the client torture module.  This call must be paired with a later
+ * torture_init_end().
+ *
+ * The runnable parameter points to a flag that controls whether or not
+ * the test is currently runnable.  If there is no such flag, pass in NULL.
+ */
+void __init torture_init_begin(char *ttype, bool v, int *runnable)
+{
+        mutex_lock(&fullstop_mutex);
+        torture_type = ttype;
+        verbose = v;
+        torture_runnable = runnable;
+        fullstop = FULLSTOP_DONTSTOP;
+
+}
+EXPORT_SYMBOL_GPL(torture_init_begin);
+
+/*
+ * Tell the torture module that initialization is complete.
+ */
+void __init torture_init_end(void)
+{
+        mutex_unlock(&fullstop_mutex);
+        register_reboot_notifier(&torture_shutdown_nb);
+}
+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, 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.
+ */
+bool torture_cleanup(void)
+{
+        mutex_lock(&fullstop_mutex);
+        if (ACCESS_ONCE(fullstop) == FULLSTOP_SHUTDOWN) {
+                pr_warn("Concurrent rmmod and shutdown illegal!\n");
+                mutex_unlock(&fullstop_mutex);
+                schedule_timeout_uninterruptible(10);
+                return true;
+        }
+        ACCESS_ONCE(fullstop) = FULLSTOP_RMMOD;
+        mutex_unlock(&fullstop_mutex);
+        torture_shutdown_cleanup();
+        torture_shuffle_cleanup();
+        torture_stutter_cleanup();
+        torture_onoff_cleanup();
+        return false;
+}
+EXPORT_SYMBOL_GPL(torture_cleanup);
+
+/*
+ * Is it time for the current torture test to stop?
+ */
+bool torture_must_stop(void)
+{
+        return torture_must_stop_irq() || kthread_should_stop();
+}
+EXPORT_SYMBOL_GPL(torture_must_stop);
+
+/*
+ * Is it time for the current torture test to stop?  This is the irq-safe
+ * version, hence no check for kthread_should_stop().
+ */
+bool torture_must_stop_irq(void)
+{
+        return ACCESS_ONCE(fullstop) != FULLSTOP_DONTSTOP;
+}
+EXPORT_SYMBOL_GPL(torture_must_stop_irq);
+
+/*
+ * Each kthread must wait for kthread_should_stop() before returning from
+ * its top-level function, otherwise segfaults ensue.  This function
+ * prints a "stopping" message and waits for kthread_should_stop(), and
+ * should be called from all torture kthreads immediately prior to
+ * returning.
+ */
+void torture_kthread_stopping(char *title)
+{
+        if (verbose)
+                VERBOSE_TOROUT_STRING(title);
+        while (!kthread_should_stop()) {
+                torture_shutdown_absorb(title);
+                schedule_timeout_uninterruptible(1);
+        }
+}
+EXPORT_SYMBOL_GPL(torture_kthread_stopping);
+
+/*
+ * Create a generic torture kthread that is immediately runnable.  If you
+ * need the kthread to be stopped so that you can do something to it before
+ * it starts, you will need to open-code your own.
+ */
+int _torture_create_kthread(int (*fn)(void *arg), void *arg, char *s, char *m,
+                            char *f, struct task_struct **tp)
+{
+        int ret = 0;
+
+        VERBOSE_TOROUT_STRING(m);
+        *tp = kthread_run(fn, arg, s);
+        if (IS_ERR(*tp)) {
+                ret = PTR_ERR(*tp);
+                VERBOSE_TOROUT_ERRSTRING(f);
+                *tp = NULL;
+        }
+        torture_shuffle_task_register(*tp);
+        return ret;
+}
+EXPORT_SYMBOL_GPL(_torture_create_kthread);
+
+/*
+ * Stop a generic kthread, emitting a message.
+ */
+void _torture_stop_kthread(char *m, struct task_struct **tp)
+{
+        if (*tp == NULL)
+                return;
+        VERBOSE_TOROUT_STRING(m);
+        kthread_stop(*tp);
+        *tp = NULL;
+}
+EXPORT_SYMBOL_GPL(_torture_stop_kthread);