1 // SPDX-License-Identifier: GPL-2.0+
3 * Common functions for in-kernel torture tests.
5 * Copyright (C) IBM Corporation, 2014
7 * Author: Paul E. McKenney <paulmck@linux.ibm.com>
8 * Based on kernel/rcu/torture.c.
11 #define pr_fmt(fmt) fmt
13 #include <linux/types.h>
14 #include <linux/kernel.h>
15 #include <linux/init.h>
16 #include <linux/module.h>
17 #include <linux/kthread.h>
18 #include <linux/err.h>
19 #include <linux/spinlock.h>
20 #include <linux/smp.h>
21 #include <linux/interrupt.h>
22 #include <linux/sched.h>
23 #include <linux/sched/clock.h>
24 #include <linux/atomic.h>
25 #include <linux/bitops.h>
26 #include <linux/completion.h>
27 #include <linux/moduleparam.h>
28 #include <linux/percpu.h>
29 #include <linux/notifier.h>
30 #include <linux/reboot.h>
31 #include <linux/freezer.h>
32 #include <linux/cpu.h>
33 #include <linux/delay.h>
34 #include <linux/stat.h>
35 #include <linux/slab.h>
36 #include <linux/trace_clock.h>
37 #include <linux/ktime.h>
38 #include <asm/byteorder.h>
39 #include <linux/torture.h>
42 MODULE_LICENSE("GPL");
43 MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com>");
45 static bool disable_onoff_at_boot
;
46 module_param(disable_onoff_at_boot
, bool, 0444);
48 static bool ftrace_dump_at_shutdown
;
49 module_param(ftrace_dump_at_shutdown
, bool, 0444);
51 static int verbose_sleep_frequency
;
52 module_param(verbose_sleep_frequency
, int, 0444);
54 static int verbose_sleep_duration
= 1;
55 module_param(verbose_sleep_duration
, int, 0444);
57 static char *torture_type
;
60 /* Mediate rmmod and system shutdown. Concurrent rmmod & shutdown illegal! */
61 #define FULLSTOP_DONTSTOP 0 /* Normal operation. */
62 #define FULLSTOP_SHUTDOWN 1 /* System shutdown with torture running. */
63 #define FULLSTOP_RMMOD 2 /* Normal rmmod of torture. */
64 static int fullstop
= FULLSTOP_RMMOD
;
65 static DEFINE_MUTEX(fullstop_mutex
);
67 static atomic_t verbose_sleep_counter
;
70 * Sleep if needed from VERBOSE_TOROUT*().
72 void verbose_torout_sleep(void)
74 if (verbose_sleep_frequency
> 0 &&
75 verbose_sleep_duration
> 0 &&
76 !(atomic_inc_return(&verbose_sleep_counter
) % verbose_sleep_frequency
))
77 schedule_timeout_uninterruptible(verbose_sleep_duration
);
79 EXPORT_SYMBOL_GPL(verbose_torout_sleep
);
82 * Schedule a high-resolution-timer sleep in nanoseconds, with a 32-bit
83 * nanosecond random fuzz. This function and its friends desynchronize
84 * testing from the timer wheel.
86 int torture_hrtimeout_ns(ktime_t baset_ns
, u32 fuzzt_ns
, struct torture_random_state
*trsp
)
88 ktime_t hto
= baset_ns
;
91 hto
+= (torture_random(trsp
) >> 3) % fuzzt_ns
;
92 set_current_state(TASK_UNINTERRUPTIBLE
);
93 return schedule_hrtimeout(&hto
, HRTIMER_MODE_REL
);
95 EXPORT_SYMBOL_GPL(torture_hrtimeout_ns
);
98 * Schedule a high-resolution-timer sleep in microseconds, with a 32-bit
99 * nanosecond (not microsecond!) random fuzz.
101 int torture_hrtimeout_us(u32 baset_us
, u32 fuzzt_ns
, struct torture_random_state
*trsp
)
103 ktime_t baset_ns
= baset_us
* NSEC_PER_USEC
;
105 return torture_hrtimeout_ns(baset_ns
, fuzzt_ns
, trsp
);
107 EXPORT_SYMBOL_GPL(torture_hrtimeout_us
);
110 * Schedule a high-resolution-timer sleep in milliseconds, with a 32-bit
111 * microsecond (not millisecond!) random fuzz.
113 int torture_hrtimeout_ms(u32 baset_ms
, u32 fuzzt_us
, struct torture_random_state
*trsp
)
115 ktime_t baset_ns
= baset_ms
* NSEC_PER_MSEC
;
118 if ((u32
)~0U / NSEC_PER_USEC
< fuzzt_us
)
121 fuzzt_ns
= fuzzt_us
* NSEC_PER_USEC
;
122 return torture_hrtimeout_ns(baset_ns
, fuzzt_ns
, trsp
);
124 EXPORT_SYMBOL_GPL(torture_hrtimeout_ms
);
127 * Schedule a high-resolution-timer sleep in jiffies, with an
128 * implied one-jiffy random fuzz. This is intended to replace calls to
129 * schedule_timeout_interruptible() and friends.
131 int torture_hrtimeout_jiffies(u32 baset_j
, struct torture_random_state
*trsp
)
133 ktime_t baset_ns
= jiffies_to_nsecs(baset_j
);
135 return torture_hrtimeout_ns(baset_ns
, jiffies_to_nsecs(1), trsp
);
137 EXPORT_SYMBOL_GPL(torture_hrtimeout_jiffies
);
140 * Schedule a high-resolution-timer sleep in milliseconds, with a 32-bit
141 * millisecond (not second!) random fuzz.
143 int torture_hrtimeout_s(u32 baset_s
, u32 fuzzt_ms
, struct torture_random_state
*trsp
)
145 ktime_t baset_ns
= baset_s
* NSEC_PER_SEC
;
148 if ((u32
)~0U / NSEC_PER_MSEC
< fuzzt_ms
)
151 fuzzt_ns
= fuzzt_ms
* NSEC_PER_MSEC
;
152 return torture_hrtimeout_ns(baset_ns
, fuzzt_ns
, trsp
);
154 EXPORT_SYMBOL_GPL(torture_hrtimeout_s
);
156 #ifdef CONFIG_HOTPLUG_CPU
159 * Variables for online-offline handling. Only present if CPU hotplug
160 * is enabled, otherwise does nothing.
163 static struct task_struct
*onoff_task
;
164 static long onoff_holdoff
;
165 static long onoff_interval
;
166 static torture_ofl_func
*onoff_f
;
167 static long n_offline_attempts
;
168 static long n_offline_successes
;
169 static unsigned long sum_offline
;
170 static int min_offline
= -1;
171 static int max_offline
;
172 static long n_online_attempts
;
173 static long n_online_successes
;
174 static unsigned long sum_online
;
175 static int min_online
= -1;
176 static int max_online
;
178 static int torture_online_cpus
= NR_CPUS
;
181 * Some torture testing leverages confusion as to the number of online
182 * CPUs. This function returns the torture-testing view of this number,
183 * which allows torture tests to load-balance appropriately.
185 int torture_num_online_cpus(void)
187 return READ_ONCE(torture_online_cpus
);
189 EXPORT_SYMBOL_GPL(torture_num_online_cpus
);
192 * Attempt to take a CPU offline. Return false if the CPU is already
193 * offline or if it is not subject to CPU-hotplug operations. The
194 * caller can detect other failures by looking at the statistics.
196 bool torture_offline(int cpu
, long *n_offl_attempts
, long *n_offl_successes
,
197 unsigned long *sum_offl
, int *min_offl
, int *max_offl
)
202 unsigned long starttime
;
204 if (!cpu_online(cpu
) || !cpu_is_hotpluggable(cpu
))
206 if (num_online_cpus() <= 1)
207 return false; /* Can't offline the last CPU. */
210 pr_alert("%s" TORTURE_FLAG
211 "torture_onoff task: offlining %d\n",
214 (*n_offl_attempts
)++;
215 ret
= remove_cpu(cpu
);
218 if (!rcu_inkernel_boot_has_ended() && ret
== -EBUSY
) {
219 // PCI probe frequently disables hotplug during boot.
220 (*n_offl_attempts
)--;
221 s
= " (-EBUSY forgiven during boot)";
224 pr_alert("%s" TORTURE_FLAG
225 "torture_onoff task: offline %d failed%s: errno %d\n",
226 torture_type
, cpu
, s
, ret
);
229 pr_alert("%s" TORTURE_FLAG
230 "torture_onoff task: offlined %d\n",
234 (*n_offl_successes
)++;
235 delta
= jiffies
- starttime
;
241 if (*min_offl
> delta
)
243 if (*max_offl
< delta
)
245 WRITE_ONCE(torture_online_cpus
, torture_online_cpus
- 1);
246 WARN_ON_ONCE(torture_online_cpus
<= 0);
251 EXPORT_SYMBOL_GPL(torture_offline
);
254 * Attempt to bring a CPU online. Return false if the CPU is already
255 * online or if it is not subject to CPU-hotplug operations. The
256 * caller can detect other failures by looking at the statistics.
258 bool torture_online(int cpu
, long *n_onl_attempts
, long *n_onl_successes
,
259 unsigned long *sum_onl
, int *min_onl
, int *max_onl
)
264 unsigned long starttime
;
266 if (cpu_online(cpu
) || !cpu_is_hotpluggable(cpu
))
270 pr_alert("%s" TORTURE_FLAG
271 "torture_onoff task: onlining %d\n",
278 if (!rcu_inkernel_boot_has_ended() && ret
== -EBUSY
) {
279 // PCI probe frequently disables hotplug during boot.
281 s
= " (-EBUSY forgiven during boot)";
284 pr_alert("%s" TORTURE_FLAG
285 "torture_onoff task: online %d failed%s: errno %d\n",
286 torture_type
, cpu
, s
, ret
);
289 pr_alert("%s" TORTURE_FLAG
290 "torture_onoff task: onlined %d\n",
292 (*n_onl_successes
)++;
293 delta
= jiffies
- starttime
;
299 if (*min_onl
> delta
)
301 if (*max_onl
< delta
)
303 WRITE_ONCE(torture_online_cpus
, torture_online_cpus
+ 1);
308 EXPORT_SYMBOL_GPL(torture_online
);
311 * Get everything online at the beginning and ends of tests.
313 static void torture_online_all(char *phase
)
318 for_each_possible_cpu(cpu
) {
322 if (ret
&& verbose
) {
323 pr_alert("%s" TORTURE_FLAG
324 "%s: %s online %d: errno %d\n",
325 __func__
, phase
, torture_type
, cpu
, ret
);
331 * Execute random CPU-hotplug operations at the interval specified
332 * by the onoff_interval.
335 torture_onoff(void *arg
)
339 DEFINE_TORTURE_RANDOM(rand
);
341 VERBOSE_TOROUT_STRING("torture_onoff task started");
342 for_each_online_cpu(cpu
)
345 torture_online_all("Initial");
347 VERBOSE_TOROUT_STRING("Only one CPU, so CPU-hotplug testing is disabled");
351 if (onoff_holdoff
> 0) {
352 VERBOSE_TOROUT_STRING("torture_onoff begin holdoff");
353 schedule_timeout_interruptible(onoff_holdoff
);
354 VERBOSE_TOROUT_STRING("torture_onoff end holdoff");
356 while (!torture_must_stop()) {
357 if (disable_onoff_at_boot
&& !rcu_inkernel_boot_has_ended()) {
358 schedule_timeout_interruptible(HZ
/ 10);
361 cpu
= (torture_random(&rand
) >> 4) % (maxcpu
+ 1);
362 if (!torture_offline(cpu
,
363 &n_offline_attempts
, &n_offline_successes
,
364 &sum_offline
, &min_offline
, &max_offline
))
366 &n_online_attempts
, &n_online_successes
,
367 &sum_online
, &min_online
, &max_online
);
368 schedule_timeout_interruptible(onoff_interval
);
372 torture_kthread_stopping("torture_onoff");
373 torture_online_all("Final");
377 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
380 * Initiate online-offline handling.
382 int torture_onoff_init(long ooholdoff
, long oointerval
, torture_ofl_func
*f
)
384 #ifdef CONFIG_HOTPLUG_CPU
385 onoff_holdoff
= ooholdoff
;
386 onoff_interval
= oointerval
;
388 if (onoff_interval
<= 0)
390 return torture_create_kthread(torture_onoff
, NULL
, onoff_task
);
391 #else /* #ifdef CONFIG_HOTPLUG_CPU */
393 #endif /* #else #ifdef CONFIG_HOTPLUG_CPU */
395 EXPORT_SYMBOL_GPL(torture_onoff_init
);
398 * Clean up after online/offline testing.
400 static void torture_onoff_cleanup(void)
402 #ifdef CONFIG_HOTPLUG_CPU
403 if (onoff_task
== NULL
)
405 VERBOSE_TOROUT_STRING("Stopping torture_onoff task");
406 kthread_stop(onoff_task
);
408 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
412 * Print online/offline testing statistics.
414 void torture_onoff_stats(void)
416 #ifdef CONFIG_HOTPLUG_CPU
417 pr_cont("onoff: %ld/%ld:%ld/%ld %d,%d:%d,%d %lu:%lu (HZ=%d) ",
418 n_online_successes
, n_online_attempts
,
419 n_offline_successes
, n_offline_attempts
,
420 min_online
, max_online
,
421 min_offline
, max_offline
,
422 sum_online
, sum_offline
, HZ
);
423 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
425 EXPORT_SYMBOL_GPL(torture_onoff_stats
);
428 * Were all the online/offline operations successful?
430 bool torture_onoff_failures(void)
432 #ifdef CONFIG_HOTPLUG_CPU
433 return n_online_successes
!= n_online_attempts
||
434 n_offline_successes
!= n_offline_attempts
;
435 #else /* #ifdef CONFIG_HOTPLUG_CPU */
437 #endif /* #else #ifdef CONFIG_HOTPLUG_CPU */
439 EXPORT_SYMBOL_GPL(torture_onoff_failures
);
441 #define TORTURE_RANDOM_MULT 39916801 /* prime */
442 #define TORTURE_RANDOM_ADD 479001701 /* prime */
443 #define TORTURE_RANDOM_REFRESH 10000
446 * Crude but fast random-number generator. Uses a linear congruential
447 * generator, with occasional help from cpu_clock().
450 torture_random(struct torture_random_state
*trsp
)
452 if (--trsp
->trs_count
< 0) {
453 trsp
->trs_state
+= (unsigned long)local_clock();
454 trsp
->trs_count
= TORTURE_RANDOM_REFRESH
;
456 trsp
->trs_state
= trsp
->trs_state
* TORTURE_RANDOM_MULT
+
458 return swahw32(trsp
->trs_state
);
460 EXPORT_SYMBOL_GPL(torture_random
);
463 * Variables for shuffling. The idea is to ensure that each CPU stays
464 * idle for an extended period to test interactions with dyntick idle,
465 * as well as interactions with any per-CPU variables.
467 struct shuffle_task
{
468 struct list_head st_l
;
469 struct task_struct
*st_t
;
472 static long shuffle_interval
; /* In jiffies. */
473 static struct task_struct
*shuffler_task
;
474 static cpumask_var_t shuffle_tmp_mask
;
475 static int shuffle_idle_cpu
; /* Force all torture tasks off this CPU */
476 static struct list_head shuffle_task_list
= LIST_HEAD_INIT(shuffle_task_list
);
477 static DEFINE_MUTEX(shuffle_task_mutex
);
480 * Register a task to be shuffled. If there is no memory, just splat
481 * and don't bother registering.
483 void torture_shuffle_task_register(struct task_struct
*tp
)
485 struct shuffle_task
*stp
;
487 if (WARN_ON_ONCE(tp
== NULL
))
489 stp
= kmalloc(sizeof(*stp
), GFP_KERNEL
);
490 if (WARN_ON_ONCE(stp
== NULL
))
493 mutex_lock(&shuffle_task_mutex
);
494 list_add(&stp
->st_l
, &shuffle_task_list
);
495 mutex_unlock(&shuffle_task_mutex
);
497 EXPORT_SYMBOL_GPL(torture_shuffle_task_register
);
500 * Unregister all tasks, for example, at the end of the torture run.
502 static void torture_shuffle_task_unregister_all(void)
504 struct shuffle_task
*stp
;
505 struct shuffle_task
*p
;
507 mutex_lock(&shuffle_task_mutex
);
508 list_for_each_entry_safe(stp
, p
, &shuffle_task_list
, st_l
) {
509 list_del(&stp
->st_l
);
512 mutex_unlock(&shuffle_task_mutex
);
515 /* Shuffle tasks such that we allow shuffle_idle_cpu to become idle.
516 * A special case is when shuffle_idle_cpu = -1, in which case we allow
517 * the tasks to run on all CPUs.
519 static void torture_shuffle_tasks(void)
521 struct shuffle_task
*stp
;
523 cpumask_setall(shuffle_tmp_mask
);
526 /* No point in shuffling if there is only one online CPU (ex: UP) */
527 if (num_online_cpus() == 1) {
532 /* Advance to the next CPU. Upon overflow, don't idle any CPUs. */
533 shuffle_idle_cpu
= cpumask_next(shuffle_idle_cpu
, shuffle_tmp_mask
);
534 if (shuffle_idle_cpu
>= nr_cpu_ids
)
535 shuffle_idle_cpu
= -1;
537 cpumask_clear_cpu(shuffle_idle_cpu
, shuffle_tmp_mask
);
539 mutex_lock(&shuffle_task_mutex
);
540 list_for_each_entry(stp
, &shuffle_task_list
, st_l
)
541 set_cpus_allowed_ptr(stp
->st_t
, shuffle_tmp_mask
);
542 mutex_unlock(&shuffle_task_mutex
);
547 /* Shuffle tasks across CPUs, with the intent of allowing each CPU in the
548 * system to become idle at a time and cut off its timer ticks. This is meant
549 * to test the support for such tickless idle CPU in RCU.
551 static int torture_shuffle(void *arg
)
553 VERBOSE_TOROUT_STRING("torture_shuffle task started");
555 schedule_timeout_interruptible(shuffle_interval
);
556 torture_shuffle_tasks();
557 torture_shutdown_absorb("torture_shuffle");
558 } while (!torture_must_stop());
559 torture_kthread_stopping("torture_shuffle");
564 * Start the shuffler, with shuffint in jiffies.
566 int torture_shuffle_init(long shuffint
)
568 shuffle_interval
= shuffint
;
570 shuffle_idle_cpu
= -1;
572 if (!alloc_cpumask_var(&shuffle_tmp_mask
, GFP_KERNEL
)) {
573 VERBOSE_TOROUT_ERRSTRING("Failed to alloc mask");
577 /* Create the shuffler thread */
578 return torture_create_kthread(torture_shuffle
, NULL
, shuffler_task
);
580 EXPORT_SYMBOL_GPL(torture_shuffle_init
);
583 * Stop the shuffling.
585 static void torture_shuffle_cleanup(void)
587 torture_shuffle_task_unregister_all();
589 VERBOSE_TOROUT_STRING("Stopping torture_shuffle task");
590 kthread_stop(shuffler_task
);
591 free_cpumask_var(shuffle_tmp_mask
);
593 shuffler_task
= NULL
;
597 * Variables for auto-shutdown. This allows "lights out" torture runs
598 * to be fully scripted.
600 static struct task_struct
*shutdown_task
;
601 static ktime_t shutdown_time
; /* time to system shutdown. */
602 static void (*torture_shutdown_hook
)(void);
605 * Absorb kthreads into a kernel function that won't return, so that
606 * they won't ever access module text or data again.
608 void torture_shutdown_absorb(const char *title
)
610 while (READ_ONCE(fullstop
) == FULLSTOP_SHUTDOWN
) {
611 pr_notice("torture thread %s parking due to system shutdown\n",
613 schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT
);
616 EXPORT_SYMBOL_GPL(torture_shutdown_absorb
);
619 * Cause the torture test to shutdown the system after the test has
620 * run for the time specified by the shutdown_secs parameter.
622 static int torture_shutdown(void *arg
)
626 VERBOSE_TOROUT_STRING("torture_shutdown task started");
627 ktime_snap
= ktime_get();
628 while (ktime_before(ktime_snap
, shutdown_time
) &&
629 !torture_must_stop()) {
631 pr_alert("%s" TORTURE_FLAG
632 "torture_shutdown task: %llu ms remaining\n",
634 ktime_ms_delta(shutdown_time
, ktime_snap
));
635 set_current_state(TASK_INTERRUPTIBLE
);
636 schedule_hrtimeout(&shutdown_time
, HRTIMER_MODE_ABS
);
637 ktime_snap
= ktime_get();
639 if (torture_must_stop()) {
640 torture_kthread_stopping("torture_shutdown");
644 /* OK, shut down the system. */
646 VERBOSE_TOROUT_STRING("torture_shutdown task shutting down system");
647 shutdown_task
= NULL
; /* Avoid self-kill deadlock. */
648 if (torture_shutdown_hook
)
649 torture_shutdown_hook();
651 VERBOSE_TOROUT_STRING("No torture_shutdown_hook(), skipping.");
652 if (ftrace_dump_at_shutdown
)
653 rcu_ftrace_dump(DUMP_ALL
);
654 kernel_power_off(); /* Shut down the system. */
659 * Start up the shutdown task.
661 int torture_shutdown_init(int ssecs
, void (*cleanup
)(void))
663 torture_shutdown_hook
= cleanup
;
665 shutdown_time
= ktime_add(ktime_get(), ktime_set(ssecs
, 0));
666 return torture_create_kthread(torture_shutdown
, NULL
,
671 EXPORT_SYMBOL_GPL(torture_shutdown_init
);
674 * Detect and respond to a system shutdown.
676 static int torture_shutdown_notify(struct notifier_block
*unused1
,
677 unsigned long unused2
, void *unused3
)
679 mutex_lock(&fullstop_mutex
);
680 if (READ_ONCE(fullstop
) == FULLSTOP_DONTSTOP
) {
681 VERBOSE_TOROUT_STRING("Unscheduled system shutdown detected");
682 WRITE_ONCE(fullstop
, FULLSTOP_SHUTDOWN
);
684 pr_warn("Concurrent rmmod and shutdown illegal!\n");
686 mutex_unlock(&fullstop_mutex
);
690 static struct notifier_block torture_shutdown_nb
= {
691 .notifier_call
= torture_shutdown_notify
,
695 * Shut down the shutdown task. Say what??? Heh! This can happen if
696 * the torture module gets an rmmod before the shutdown time arrives. ;-)
698 static void torture_shutdown_cleanup(void)
700 unregister_reboot_notifier(&torture_shutdown_nb
);
701 if (shutdown_task
!= NULL
) {
702 VERBOSE_TOROUT_STRING("Stopping torture_shutdown task");
703 kthread_stop(shutdown_task
);
705 shutdown_task
= NULL
;
709 * Variables for stuttering, which means to periodically pause and
710 * restart testing in order to catch bugs that appear when load is
711 * suddenly applied to or removed from the system.
713 static struct task_struct
*stutter_task
;
714 static int stutter_pause_test
;
716 static int stutter_gap
;
719 * Block until the stutter interval ends. This must be called periodically
720 * by all running kthreads that need to be subject to stuttering.
722 bool stutter_wait(const char *title
)
728 cond_resched_tasks_rcu_qs();
729 spt
= READ_ONCE(stutter_pause_test
);
730 for (; spt
; spt
= READ_ONCE(stutter_pause_test
)) {
732 sched_set_normal(current
, MAX_NICE
);
736 schedule_timeout_interruptible(1);
737 } else if (spt
== 2) {
738 while (READ_ONCE(stutter_pause_test
)) {
740 torture_hrtimeout_us(10, 0, NULL
);
744 schedule_timeout_interruptible(round_jiffies_relative(HZ
));
746 torture_shutdown_absorb(title
);
750 EXPORT_SYMBOL_GPL(stutter_wait
);
753 * Cause the torture test to "stutter", starting and stopping all
754 * threads periodically.
756 static int torture_stutter(void *arg
)
758 DEFINE_TORTURE_RANDOM(rand
);
761 VERBOSE_TOROUT_STRING("torture_stutter task started");
763 if (!torture_must_stop() && stutter
> 1) {
766 WRITE_ONCE(stutter_pause_test
, 1);
768 torture_hrtimeout_jiffies(wtime
, &rand
);
771 WRITE_ONCE(stutter_pause_test
, 2);
772 torture_hrtimeout_jiffies(wtime
, NULL
);
774 WRITE_ONCE(stutter_pause_test
, 0);
775 if (!torture_must_stop())
776 torture_hrtimeout_jiffies(stutter_gap
, NULL
);
777 torture_shutdown_absorb("torture_stutter");
778 } while (!torture_must_stop());
779 torture_kthread_stopping("torture_stutter");
784 * Initialize and kick off the torture_stutter kthread.
786 int torture_stutter_init(const int s
, const int sgap
)
790 return torture_create_kthread(torture_stutter
, NULL
, stutter_task
);
792 EXPORT_SYMBOL_GPL(torture_stutter_init
);
795 * Cleanup after the torture_stutter kthread.
797 static void torture_stutter_cleanup(void)
801 VERBOSE_TOROUT_STRING("Stopping torture_stutter task");
802 kthread_stop(stutter_task
);
807 * Initialize torture module. Please note that this is -not- invoked via
808 * the usual module_init() mechanism, but rather by an explicit call from
809 * the client torture module. This call must be paired with a later
810 * torture_init_end().
812 * The runnable parameter points to a flag that controls whether or not
813 * the test is currently runnable. If there is no such flag, pass in NULL.
815 bool torture_init_begin(char *ttype
, int v
)
817 mutex_lock(&fullstop_mutex
);
818 if (torture_type
!= NULL
) {
819 pr_alert("%s: Refusing %s init: %s running.\n",
820 __func__
, ttype
, torture_type
);
821 pr_alert("%s: One torture test at a time!\n", __func__
);
822 mutex_unlock(&fullstop_mutex
);
825 torture_type
= ttype
;
827 fullstop
= FULLSTOP_DONTSTOP
;
830 EXPORT_SYMBOL_GPL(torture_init_begin
);
833 * Tell the torture module that initialization is complete.
835 void torture_init_end(void)
837 mutex_unlock(&fullstop_mutex
);
838 register_reboot_notifier(&torture_shutdown_nb
);
840 EXPORT_SYMBOL_GPL(torture_init_end
);
843 * Clean up torture module. Please note that this is -not- invoked via
844 * the usual module_exit() mechanism, but rather by an explicit call from
845 * the client torture module. Returns true if a race with system shutdown
846 * is detected, otherwise, all kthreads started by functions in this file
849 * This must be called before the caller starts shutting down its own
852 * Both torture_cleanup_begin() and torture_cleanup_end() must be paired,
853 * in order to correctly perform the cleanup. They are separated because
854 * threads can still need to reference the torture_type type, thus nullify
855 * only after completing all other relevant calls.
857 bool torture_cleanup_begin(void)
859 mutex_lock(&fullstop_mutex
);
860 if (READ_ONCE(fullstop
) == FULLSTOP_SHUTDOWN
) {
861 pr_warn("Concurrent rmmod and shutdown illegal!\n");
862 mutex_unlock(&fullstop_mutex
);
863 schedule_timeout_uninterruptible(10);
866 WRITE_ONCE(fullstop
, FULLSTOP_RMMOD
);
867 mutex_unlock(&fullstop_mutex
);
868 torture_shutdown_cleanup();
869 torture_shuffle_cleanup();
870 torture_stutter_cleanup();
871 torture_onoff_cleanup();
874 EXPORT_SYMBOL_GPL(torture_cleanup_begin
);
876 void torture_cleanup_end(void)
878 mutex_lock(&fullstop_mutex
);
880 mutex_unlock(&fullstop_mutex
);
882 EXPORT_SYMBOL_GPL(torture_cleanup_end
);
885 * Is it time for the current torture test to stop?
887 bool torture_must_stop(void)
889 return torture_must_stop_irq() || kthread_should_stop();
891 EXPORT_SYMBOL_GPL(torture_must_stop
);
894 * Is it time for the current torture test to stop? This is the irq-safe
895 * version, hence no check for kthread_should_stop().
897 bool torture_must_stop_irq(void)
899 return READ_ONCE(fullstop
) != FULLSTOP_DONTSTOP
;
901 EXPORT_SYMBOL_GPL(torture_must_stop_irq
);
904 * Each kthread must wait for kthread_should_stop() before returning from
905 * its top-level function, otherwise segfaults ensue. This function
906 * prints a "stopping" message and waits for kthread_should_stop(), and
907 * should be called from all torture kthreads immediately prior to
910 void torture_kthread_stopping(char *title
)
914 snprintf(buf
, sizeof(buf
), "Stopping %s", title
);
915 VERBOSE_TOROUT_STRING(buf
);
916 while (!kthread_should_stop()) {
917 torture_shutdown_absorb(title
);
918 schedule_timeout_uninterruptible(1);
921 EXPORT_SYMBOL_GPL(torture_kthread_stopping
);
924 * Create a generic torture kthread that is immediately runnable. If you
925 * need the kthread to be stopped so that you can do something to it before
926 * it starts, you will need to open-code your own.
928 int _torture_create_kthread(int (*fn
)(void *arg
), void *arg
, char *s
, char *m
,
929 char *f
, struct task_struct
**tp
)
933 VERBOSE_TOROUT_STRING(m
);
934 *tp
= kthread_run(fn
, arg
, "%s", s
);
937 VERBOSE_TOROUT_ERRSTRING(f
);
940 torture_shuffle_task_register(*tp
);
943 EXPORT_SYMBOL_GPL(_torture_create_kthread
);
946 * Stop a generic kthread, emitting a message.
948 void _torture_stop_kthread(char *m
, struct task_struct
**tp
)
952 VERBOSE_TOROUT_STRING(m
);
956 EXPORT_SYMBOL_GPL(_torture_stop_kthread
);