1 // SPDX-License-Identifier: GPL-2.0+ 1
2 /*
3 * Common functions for in-kernel torture test
4 *
5 * Copyright (C) IBM Corporation, 2014
6 *
7 * Author: Paul E. McKenney <paulmck@linux.ibm
8 * Based on kernel/rcu/torture.c.
9 */
10
11 #define pr_fmt(fmt) fmt
12
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>
40 #include <linux/sched/rt.h>
41 #include "rcu/rcu.h"
42
43 MODULE_DESCRIPTION("Common functions for in-ke
44 MODULE_LICENSE("GPL");
45 MODULE_AUTHOR("Paul E. McKenney <paulmck@linux
46
47 static bool disable_onoff_at_boot;
48 module_param(disable_onoff_at_boot, bool, 0444
49
50 static bool ftrace_dump_at_shutdown;
51 module_param(ftrace_dump_at_shutdown, bool, 04
52
53 static int verbose_sleep_frequency;
54 module_param(verbose_sleep_frequency, int, 044
55
56 static int verbose_sleep_duration = 1;
57 module_param(verbose_sleep_duration, int, 0444
58
59 static int random_shuffle;
60 module_param(random_shuffle, int, 0444);
61
62 static char *torture_type;
63 static int verbose;
64
65 /* Mediate rmmod and system shutdown. Concurr
66 #define FULLSTOP_DONTSTOP 0 /* Normal oper
67 #define FULLSTOP_SHUTDOWN 1 /* System shut
68 #define FULLSTOP_RMMOD 2 /* Normal rmmo
69 static int fullstop = FULLSTOP_RMMOD;
70 static DEFINE_MUTEX(fullstop_mutex);
71
72 static atomic_t verbose_sleep_counter;
73
74 /*
75 * Sleep if needed from VERBOSE_TOROUT*().
76 */
77 void verbose_torout_sleep(void)
78 {
79 if (verbose_sleep_frequency > 0 &&
80 verbose_sleep_duration > 0 &&
81 !(atomic_inc_return(&verbose_sleep
82 schedule_timeout_uninterruptib
83 }
84 EXPORT_SYMBOL_GPL(verbose_torout_sleep);
85
86 /*
87 * Schedule a high-resolution-timer sleep in n
88 * nanosecond random fuzz. This function and
89 * testing from the timer wheel.
90 */
91 int torture_hrtimeout_ns(ktime_t baset_ns, u32
92 struct torture_random
93 {
94 ktime_t hto = baset_ns;
95
96 if (trsp)
97 hto += torture_random(trsp) %
98 set_current_state(TASK_IDLE);
99 return schedule_hrtimeout(&hto, mode);
100 }
101 EXPORT_SYMBOL_GPL(torture_hrtimeout_ns);
102
103 /*
104 * Schedule a high-resolution-timer sleep in m
105 * nanosecond (not microsecond!) random fuzz.
106 */
107 int torture_hrtimeout_us(u32 baset_us, u32 fuz
108 {
109 ktime_t baset_ns = baset_us * NSEC_PER
110
111 return torture_hrtimeout_ns(baset_ns,
112 }
113 EXPORT_SYMBOL_GPL(torture_hrtimeout_us);
114
115 /*
116 * Schedule a high-resolution-timer sleep in m
117 * microsecond (not millisecond!) random fuzz.
118 */
119 int torture_hrtimeout_ms(u32 baset_ms, u32 fuz
120 {
121 ktime_t baset_ns = baset_ms * NSEC_PER
122 u32 fuzzt_ns;
123
124 if ((u32)~0U / NSEC_PER_USEC < fuzzt_u
125 fuzzt_ns = (u32)~0U;
126 else
127 fuzzt_ns = fuzzt_us * NSEC_PER
128 return torture_hrtimeout_ns(baset_ns,
129 }
130 EXPORT_SYMBOL_GPL(torture_hrtimeout_ms);
131
132 /*
133 * Schedule a high-resolution-timer sleep in j
134 * implied one-jiffy random fuzz. This is int
135 * schedule_timeout_interruptible() and friend
136 */
137 int torture_hrtimeout_jiffies(u32 baset_j, str
138 {
139 ktime_t baset_ns = jiffies_to_nsecs(ba
140
141 return torture_hrtimeout_ns(baset_ns,
142 }
143 EXPORT_SYMBOL_GPL(torture_hrtimeout_jiffies);
144
145 /*
146 * Schedule a high-resolution-timer sleep in m
147 * millisecond (not second!) random fuzz.
148 */
149 int torture_hrtimeout_s(u32 baset_s, u32 fuzzt
150 {
151 ktime_t baset_ns = baset_s * NSEC_PER_
152 u32 fuzzt_ns;
153
154 if ((u32)~0U / NSEC_PER_MSEC < fuzzt_m
155 fuzzt_ns = (u32)~0U;
156 else
157 fuzzt_ns = fuzzt_ms * NSEC_PER
158 return torture_hrtimeout_ns(baset_ns,
159 }
160 EXPORT_SYMBOL_GPL(torture_hrtimeout_s);
161
162 #ifdef CONFIG_HOTPLUG_CPU
163
164 /*
165 * Variables for online-offline handling. Onl
166 * is enabled, otherwise does nothing.
167 */
168
169 static struct task_struct *onoff_task;
170 static long onoff_holdoff;
171 static long onoff_interval;
172 static torture_ofl_func *onoff_f;
173 static long n_offline_attempts;
174 static long n_offline_successes;
175 static unsigned long sum_offline;
176 static int min_offline = -1;
177 static int max_offline;
178 static long n_online_attempts;
179 static long n_online_successes;
180 static unsigned long sum_online;
181 static int min_online = -1;
182 static int max_online;
183
184 static int torture_online_cpus = NR_CPUS;
185
186 /*
187 * Some torture testing leverages confusion as
188 * CPUs. This function returns the torture-te
189 * which allows torture tests to load-balance
190 */
191 int torture_num_online_cpus(void)
192 {
193 return READ_ONCE(torture_online_cpus);
194 }
195 EXPORT_SYMBOL_GPL(torture_num_online_cpus);
196
197 /*
198 * Attempt to take a CPU offline. Return fals
199 * offline or if it is not subject to CPU-hotp
200 * caller can detect other failures by looking
201 */
202 bool torture_offline(int cpu, long *n_offl_att
203 unsigned long *sum_offl,
204 {
205 unsigned long delta;
206 int ret;
207 char *s;
208 unsigned long starttime;
209
210 if (!cpu_online(cpu) || !cpu_is_hotplu
211 return false;
212 if (num_online_cpus() <= 1)
213 return false; /* Can't offlin
214
215 if (verbose > 1)
216 pr_alert("%s" TORTURE_FLAG
217 "torture_onoff task:
218 torture_type, cpu);
219 starttime = jiffies;
220 (*n_offl_attempts)++;
221 ret = remove_cpu(cpu);
222 if (ret) {
223 s = "";
224 if (!rcu_inkernel_boot_has_end
225 // PCI probe frequentl
226 (*n_offl_attempts)--;
227 s = " (-EBUSY forgiven
228 }
229 if (verbose)
230 pr_alert("%s" TORTURE_
231 "torture_onof
232 torture_type,
233 } else {
234 if (verbose > 1)
235 pr_alert("%s" TORTURE_
236 "torture_onof
237 torture_type,
238 if (onoff_f)
239 onoff_f();
240 (*n_offl_successes)++;
241 delta = jiffies - starttime;
242 *sum_offl += delta;
243 if (*min_offl < 0) {
244 *min_offl = delta;
245 *max_offl = delta;
246 }
247 if (*min_offl > delta)
248 *min_offl = delta;
249 if (*max_offl < delta)
250 *max_offl = delta;
251 WRITE_ONCE(torture_online_cpus
252 WARN_ON_ONCE(torture_online_cp
253 }
254
255 return true;
256 }
257 EXPORT_SYMBOL_GPL(torture_offline);
258
259 /*
260 * Attempt to bring a CPU online. Return fals
261 * online or if it is not subject to CPU-hotpl
262 * caller can detect other failures by looking
263 */
264 bool torture_online(int cpu, long *n_onl_attem
265 unsigned long *sum_onl, in
266 {
267 unsigned long delta;
268 int ret;
269 char *s;
270 unsigned long starttime;
271
272 if (cpu_online(cpu) || !cpu_is_hotplug
273 return false;
274
275 if (verbose > 1)
276 pr_alert("%s" TORTURE_FLAG
277 "torture_onoff task:
278 torture_type, cpu);
279 starttime = jiffies;
280 (*n_onl_attempts)++;
281 ret = add_cpu(cpu);
282 if (ret) {
283 s = "";
284 if (!rcu_inkernel_boot_has_end
285 // PCI probe frequentl
286 (*n_onl_attempts)--;
287 s = " (-EBUSY forgiven
288 }
289 if (verbose)
290 pr_alert("%s" TORTURE_
291 "torture_onof
292 torture_type,
293 } else {
294 if (verbose > 1)
295 pr_alert("%s" TORTURE_
296 "torture_onof
297 torture_type,
298 (*n_onl_successes)++;
299 delta = jiffies - starttime;
300 *sum_onl += delta;
301 if (*min_onl < 0) {
302 *min_onl = delta;
303 *max_onl = delta;
304 }
305 if (*min_onl > delta)
306 *min_onl = delta;
307 if (*max_onl < delta)
308 *max_onl = delta;
309 WRITE_ONCE(torture_online_cpus
310 }
311
312 return true;
313 }
314 EXPORT_SYMBOL_GPL(torture_online);
315
316 /*
317 * Get everything online at the beginning and
318 */
319 static void torture_online_all(char *phase)
320 {
321 int cpu;
322 int ret;
323
324 for_each_possible_cpu(cpu) {
325 if (cpu_online(cpu))
326 continue;
327 ret = add_cpu(cpu);
328 if (ret && verbose) {
329 pr_alert("%s" TORTURE_
330 "%s: %s onlin
331 __func__, pha
332 }
333 }
334 }
335
336 /*
337 * Execute random CPU-hotplug operations at th
338 * by the onoff_interval.
339 */
340 static int
341 torture_onoff(void *arg)
342 {
343 int cpu;
344 int maxcpu = -1;
345 DEFINE_TORTURE_RANDOM(rand);
346
347 VERBOSE_TOROUT_STRING("torture_onoff t
348 for_each_online_cpu(cpu)
349 maxcpu = cpu;
350 WARN_ON(maxcpu < 0);
351 torture_online_all("Initial");
352 if (maxcpu == 0) {
353 VERBOSE_TOROUT_STRING("Only on
354 goto stop;
355 }
356
357 if (onoff_holdoff > 0) {
358 VERBOSE_TOROUT_STRING("torture
359 torture_hrtimeout_jiffies(onof
360 VERBOSE_TOROUT_STRING("torture
361 }
362 while (!torture_must_stop()) {
363 if (disable_onoff_at_boot && !
364 torture_hrtimeout_jiff
365 continue;
366 }
367 cpu = torture_random(&rand) %
368 if (!torture_offline(cpu,
369 &n_offlin
370 &sum_offl
371 torture_online(cpu,
372 &n_onli
373 &sum_on
374 torture_hrtimeout_jiffies(onof
375 }
376
377 stop:
378 torture_kthread_stopping("torture_onof
379 torture_online_all("Final");
380 return 0;
381 }
382
383 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
384
385 /*
386 * Initiate online-offline handling.
387 */
388 int torture_onoff_init(long ooholdoff, long oo
389 {
390 #ifdef CONFIG_HOTPLUG_CPU
391 onoff_holdoff = ooholdoff;
392 onoff_interval = oointerval;
393 onoff_f = f;
394 if (onoff_interval <= 0)
395 return 0;
396 return torture_create_kthread(torture_
397 #else /* #ifdef CONFIG_HOTPLUG_CPU */
398 return 0;
399 #endif /* #else #ifdef CONFIG_HOTPLUG_CPU */
400 }
401 EXPORT_SYMBOL_GPL(torture_onoff_init);
402
403 /*
404 * Clean up after online/offline testing.
405 */
406 static void torture_onoff_cleanup(void)
407 {
408 #ifdef CONFIG_HOTPLUG_CPU
409 if (onoff_task == NULL)
410 return;
411 VERBOSE_TOROUT_STRING("Stopping tortur
412 kthread_stop(onoff_task);
413 onoff_task = NULL;
414 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
415 }
416
417 /*
418 * Print online/offline testing statistics.
419 */
420 void torture_onoff_stats(void)
421 {
422 #ifdef CONFIG_HOTPLUG_CPU
423 pr_cont("onoff: %ld/%ld:%ld/%ld %d,%d:
424 n_online_successes, n_online_a
425 n_offline_successes, n_offline
426 min_online, max_online,
427 min_offline, max_offline,
428 sum_online, sum_offline, HZ);
429 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
430 }
431 EXPORT_SYMBOL_GPL(torture_onoff_stats);
432
433 /*
434 * Were all the online/offline operations succ
435 */
436 bool torture_onoff_failures(void)
437 {
438 #ifdef CONFIG_HOTPLUG_CPU
439 return n_online_successes != n_online_
440 n_offline_successes != n_offlin
441 #else /* #ifdef CONFIG_HOTPLUG_CPU */
442 return false;
443 #endif /* #else #ifdef CONFIG_HOTPLUG_CPU */
444 }
445 EXPORT_SYMBOL_GPL(torture_onoff_failures);
446
447 #define TORTURE_RANDOM_MULT 39916801 /* p
448 #define TORTURE_RANDOM_ADD 479001701 /* p
449 #define TORTURE_RANDOM_REFRESH 10000
450
451 /*
452 * Crude but fast random-number generator. Us
453 * generator, with occasional help from cpu_cl
454 */
455 unsigned long
456 torture_random(struct torture_random_state *tr
457 {
458 if (--trsp->trs_count < 0) {
459 trsp->trs_state += (unsigned l
460 trsp->trs_count = TORTURE_RAND
461 }
462 trsp->trs_state = trsp->trs_state * TO
463 TORTURE_RANDOM_ADD;
464 return swahw32(trsp->trs_state);
465 }
466 EXPORT_SYMBOL_GPL(torture_random);
467
468 /*
469 * Variables for shuffling. The idea is to en
470 * idle for an extended period to test interac
471 * as well as interactions with any per-CPU va
472 */
473 struct shuffle_task {
474 struct list_head st_l;
475 struct task_struct *st_t;
476 };
477
478 static long shuffle_interval; /* In jiffies.
479 static struct task_struct *shuffler_task;
480 static cpumask_var_t shuffle_tmp_mask;
481 static int shuffle_idle_cpu; /* Force all t
482 static struct list_head shuffle_task_list = LI
483 static DEFINE_MUTEX(shuffle_task_mutex);
484
485 /*
486 * Register a task to be shuffled. If there i
487 * and don't bother registering.
488 */
489 void torture_shuffle_task_register(struct task
490 {
491 struct shuffle_task *stp;
492
493 if (WARN_ON_ONCE(tp == NULL))
494 return;
495 stp = kmalloc(sizeof(*stp), GFP_KERNEL
496 if (WARN_ON_ONCE(stp == NULL))
497 return;
498 stp->st_t = tp;
499 mutex_lock(&shuffle_task_mutex);
500 list_add(&stp->st_l, &shuffle_task_lis
501 mutex_unlock(&shuffle_task_mutex);
502 }
503 EXPORT_SYMBOL_GPL(torture_shuffle_task_registe
504
505 /*
506 * Unregister all tasks, for example, at the e
507 */
508 static void torture_shuffle_task_unregister_al
509 {
510 struct shuffle_task *stp;
511 struct shuffle_task *p;
512
513 mutex_lock(&shuffle_task_mutex);
514 list_for_each_entry_safe(stp, p, &shuf
515 list_del(&stp->st_l);
516 kfree(stp);
517 }
518 mutex_unlock(&shuffle_task_mutex);
519 }
520
521 /* Shuffle tasks such that we allow shuffle_id
522 * A special case is when shuffle_idle_cpu = -
523 * the tasks to run on all CPUs.
524 */
525 static void torture_shuffle_tasks(struct tortu
526 {
527 struct shuffle_task *stp;
528
529 cpumask_setall(shuffle_tmp_mask);
530 cpus_read_lock();
531
532 /* No point in shuffling if there is o
533 if (num_online_cpus() == 1) {
534 cpus_read_unlock();
535 return;
536 }
537
538 /* Advance to the next CPU. Upon over
539 shuffle_idle_cpu = cpumask_next(shuffl
540 if (shuffle_idle_cpu >= nr_cpu_ids)
541 shuffle_idle_cpu = -1;
542 else
543 cpumask_clear_cpu(shuffle_idle
544
545 mutex_lock(&shuffle_task_mutex);
546 list_for_each_entry(stp, &shuffle_task
547 if (!random_shuffle || torture
548 set_cpus_allowed_ptr(s
549 }
550 mutex_unlock(&shuffle_task_mutex);
551
552 cpus_read_unlock();
553 }
554
555 /* Shuffle tasks across CPUs, with the intent
556 * system to become idle at a time and cut off
557 * to test the support for such tickless idle
558 */
559 static int torture_shuffle(void *arg)
560 {
561 DEFINE_TORTURE_RANDOM(rand);
562
563 VERBOSE_TOROUT_STRING("torture_shuffle
564 do {
565 torture_hrtimeout_jiffies(shuf
566 torture_shuffle_tasks(&rand);
567 torture_shutdown_absorb("tortu
568 } while (!torture_must_stop());
569 torture_kthread_stopping("torture_shuf
570 return 0;
571 }
572
573 /*
574 * Start the shuffler, with shuffint in jiffie
575 */
576 int torture_shuffle_init(long shuffint)
577 {
578 shuffle_interval = shuffint;
579
580 shuffle_idle_cpu = -1;
581
582 if (!alloc_cpumask_var(&shuffle_tmp_ma
583 TOROUT_ERRSTRING("Failed to al
584 return -ENOMEM;
585 }
586
587 /* Create the shuffler thread */
588 return torture_create_kthread(torture_
589 }
590 EXPORT_SYMBOL_GPL(torture_shuffle_init);
591
592 /*
593 * Stop the shuffling.
594 */
595 static void torture_shuffle_cleanup(void)
596 {
597 torture_shuffle_task_unregister_all();
598 if (shuffler_task) {
599 VERBOSE_TOROUT_STRING("Stoppin
600 kthread_stop(shuffler_task);
601 free_cpumask_var(shuffle_tmp_m
602 }
603 shuffler_task = NULL;
604 }
605
606 /*
607 * Variables for auto-shutdown. This allows "
608 * to be fully scripted.
609 */
610 static struct task_struct *shutdown_task;
611 static ktime_t shutdown_time; /* tim
612 static void (*torture_shutdown_hook)(void);
613
614 /*
615 * Absorb kthreads into a kernel function that
616 * they won't ever access module text or data
617 */
618 void torture_shutdown_absorb(const char *title
619 {
620 while (READ_ONCE(fullstop) == FULLSTOP
621 pr_notice("torture thread %s p
622 title);
623 schedule_timeout_uninterruptib
624 }
625 }
626 EXPORT_SYMBOL_GPL(torture_shutdown_absorb);
627
628 /*
629 * Cause the torture test to shutdown the syst
630 * run for the time specified by the shutdown_
631 */
632 static int torture_shutdown(void *arg)
633 {
634 ktime_t ktime_snap;
635
636 VERBOSE_TOROUT_STRING("torture_shutdow
637 ktime_snap = ktime_get();
638 while (ktime_before(ktime_snap, shutdo
639 !torture_must_stop()) {
640 if (verbose)
641 pr_alert("%s" TORTURE_
642 "torture_shut
643 torture_type,
644 ktime_ms_delt
645 set_current_state(TASK_INTERRU
646 schedule_hrtimeout(&shutdown_t
647 ktime_snap = ktime_get();
648 }
649 if (torture_must_stop()) {
650 torture_kthread_stopping("tort
651 return 0;
652 }
653
654 /* OK, shut down the system. */
655
656 VERBOSE_TOROUT_STRING("torture_shutdow
657 shutdown_task = NULL; /* Avoid self-
658 if (torture_shutdown_hook)
659 torture_shutdown_hook();
660 else
661 VERBOSE_TOROUT_STRING("No tort
662 if (ftrace_dump_at_shutdown)
663 rcu_ftrace_dump(DUMP_ALL);
664 kernel_power_off(); /* Shut down t
665 return 0;
666 }
667
668 /*
669 * Start up the shutdown task.
670 */
671 int torture_shutdown_init(int ssecs, void (*cl
672 {
673 torture_shutdown_hook = cleanup;
674 if (ssecs > 0) {
675 shutdown_time = ktime_add(ktim
676 return torture_create_kthread(
677
678 }
679 return 0;
680 }
681 EXPORT_SYMBOL_GPL(torture_shutdown_init);
682
683 /*
684 * Detect and respond to a system shutdown.
685 */
686 static int torture_shutdown_notify(struct noti
687 unsigned lo
688 {
689 mutex_lock(&fullstop_mutex);
690 if (READ_ONCE(fullstop) == FULLSTOP_DO
691 VERBOSE_TOROUT_STRING("Unsched
692 WRITE_ONCE(fullstop, FULLSTOP_
693 } else {
694 pr_warn("Concurrent rmmod and
695 }
696 mutex_unlock(&fullstop_mutex);
697 return NOTIFY_DONE;
698 }
699
700 static struct notifier_block torture_shutdown_
701 .notifier_call = torture_shutdown_noti
702 };
703
704 /*
705 * Shut down the shutdown task. Say what???
706 * the torture module gets an rmmod before the
707 */
708 static void torture_shutdown_cleanup(void)
709 {
710 unregister_reboot_notifier(&torture_sh
711 if (shutdown_task != NULL) {
712 VERBOSE_TOROUT_STRING("Stoppin
713 kthread_stop(shutdown_task);
714 }
715 shutdown_task = NULL;
716 }
717
718 /*
719 * Variables for stuttering, which means to pe
720 * restart testing in order to catch bugs that
721 * suddenly applied to or removed from the sys
722 */
723 static struct task_struct *stutter_task;
724 static ktime_t stutter_till_abs_time;
725 static int stutter;
726 static int stutter_gap;
727
728 /*
729 * Block until the stutter interval ends. Thi
730 * by all running kthreads that need to be sub
731 */
732 bool stutter_wait(const char *title)
733 {
734 bool ret = false;
735 ktime_t till_ns;
736
737 cond_resched_tasks_rcu_qs();
738 till_ns = READ_ONCE(stutter_till_abs_t
739 if (till_ns && ktime_before(ktime_get(
740 torture_hrtimeout_ns(till_ns,
741 ret = true;
742 }
743 torture_shutdown_absorb(title);
744 return ret;
745 }
746 EXPORT_SYMBOL_GPL(stutter_wait);
747
748 /*
749 * Cause the torture test to "stutter", starti
750 * threads periodically.
751 */
752 static int torture_stutter(void *arg)
753 {
754 ktime_t till_ns;
755
756 VERBOSE_TOROUT_STRING("torture_stutter
757 do {
758 if (!torture_must_stop() && st
759 till_ns = ktime_add_ns
760
761 WRITE_ONCE(stutter_til
762 torture_hrtimeout_jiff
763 }
764 if (!torture_must_stop())
765 torture_hrtimeout_jiff
766 torture_shutdown_absorb("tortu
767 } while (!torture_must_stop());
768 torture_kthread_stopping("torture_stut
769 return 0;
770 }
771
772 /*
773 * Initialize and kick off the torture_stutter
774 */
775 int torture_stutter_init(const int s, const in
776 {
777 stutter = s;
778 stutter_gap = sgap;
779 return torture_create_kthread(torture_
780 }
781 EXPORT_SYMBOL_GPL(torture_stutter_init);
782
783 /*
784 * Cleanup after the torture_stutter kthread.
785 */
786 static void torture_stutter_cleanup(void)
787 {
788 if (!stutter_task)
789 return;
790 VERBOSE_TOROUT_STRING("Stopping tortur
791 kthread_stop(stutter_task);
792 stutter_task = NULL;
793 }
794
795 static void
796 torture_print_module_parms(void)
797 {
798 pr_alert("torture module --- %s: disa
799 torture_type, disable_onoff_a
800 }
801
802 /*
803 * Initialize torture module. Please note tha
804 * the usual module_init() mechanism, but rath
805 * the client torture module. This call must
806 * torture_init_end().
807 *
808 * The runnable parameter points to a flag tha
809 * the test is currently runnable. If there i
810 */
811 bool torture_init_begin(char *ttype, int v)
812 {
813 mutex_lock(&fullstop_mutex);
814 if (torture_type != NULL) {
815 pr_alert("%s: Refusing %s init
816 __func__, ttype, tor
817 pr_alert("%s: One torture test
818 mutex_unlock(&fullstop_mutex);
819 return false;
820 }
821 torture_type = ttype;
822 verbose = v;
823 fullstop = FULLSTOP_DONTSTOP;
824 torture_print_module_parms();
825 return true;
826 }
827 EXPORT_SYMBOL_GPL(torture_init_begin);
828
829 /*
830 * Tell the torture module that initialization
831 */
832 void torture_init_end(void)
833 {
834 mutex_unlock(&fullstop_mutex);
835 register_reboot_notifier(&torture_shut
836 }
837 EXPORT_SYMBOL_GPL(torture_init_end);
838
839 /*
840 * Clean up torture module. Please note that
841 * the usual module_exit() mechanism, but rath
842 * the client torture module. Returns true if
843 * is detected, otherwise, all kthreads starte
844 * will be shut down.
845 *
846 * This must be called before the caller start
847 * kthreads.
848 *
849 * Both torture_cleanup_begin() and torture_cl
850 * in order to correctly perform the cleanup.
851 * threads can still need to reference the tor
852 * only after completing all other relevant ca
853 */
854 bool torture_cleanup_begin(void)
855 {
856 mutex_lock(&fullstop_mutex);
857 if (READ_ONCE(fullstop) == FULLSTOP_SH
858 pr_warn("Concurrent rmmod and
859 mutex_unlock(&fullstop_mutex);
860 schedule_timeout_uninterruptib
861 return true;
862 }
863 WRITE_ONCE(fullstop, FULLSTOP_RMMOD);
864 mutex_unlock(&fullstop_mutex);
865 torture_shutdown_cleanup();
866 torture_shuffle_cleanup();
867 torture_stutter_cleanup();
868 torture_onoff_cleanup();
869 return false;
870 }
871 EXPORT_SYMBOL_GPL(torture_cleanup_begin);
872
873 void torture_cleanup_end(void)
874 {
875 mutex_lock(&fullstop_mutex);
876 torture_type = NULL;
877 mutex_unlock(&fullstop_mutex);
878 }
879 EXPORT_SYMBOL_GPL(torture_cleanup_end);
880
881 /*
882 * Is it time for the current torture test to
883 */
884 bool torture_must_stop(void)
885 {
886 return torture_must_stop_irq() || kthr
887 }
888 EXPORT_SYMBOL_GPL(torture_must_stop);
889
890 /*
891 * Is it time for the current torture test to
892 * version, hence no check for kthread_should_
893 */
894 bool torture_must_stop_irq(void)
895 {
896 return READ_ONCE(fullstop) != FULLSTOP
897 }
898 EXPORT_SYMBOL_GPL(torture_must_stop_irq);
899
900 /*
901 * Each kthread must wait for kthread_should_s
902 * its top-level function, otherwise segfaults
903 * prints a "stopping" message and waits for k
904 * should be called from all torture kthreads
905 * returning.
906 */
907 void torture_kthread_stopping(char *title)
908 {
909 char buf[128];
910
911 snprintf(buf, sizeof(buf), "%s is stop
912 VERBOSE_TOROUT_STRING(buf);
913 while (!kthread_should_stop()) {
914 torture_shutdown_absorb(title)
915 schedule_timeout_uninterruptib
916 }
917 }
918 EXPORT_SYMBOL_GPL(torture_kthread_stopping);
919
920 /*
921 * Create a generic torture kthread that is im
922 * need the kthread to be stopped so that you
923 * it starts, you will need to open-code your
924 */
925 int _torture_create_kthread(int (*fn)(void *ar
926 char *f, struct ta
927 {
928 int ret = 0;
929
930 VERBOSE_TOROUT_STRING(m);
931 *tp = kthread_create(fn, arg, "%s", s)
932 if (IS_ERR(*tp)) {
933 ret = PTR_ERR(*tp);
934 TOROUT_ERRSTRING(f);
935 *tp = NULL;
936 return ret;
937 }
938
939 if (cbf)
940 cbf(*tp);
941
942 wake_up_process(*tp); // Process is s
943 torture_shuffle_task_register(*tp);
944 return ret;
945 }
946 EXPORT_SYMBOL_GPL(_torture_create_kthread);
947
948 /*
949 * Stop a generic kthread, emitting a message.
950 */
951 void _torture_stop_kthread(char *m, struct tas
952 {
953 if (*tp == NULL)
954 return;
955 VERBOSE_TOROUT_STRING(m);
956 kthread_stop(*tp);
957 *tp = NULL;
958 }
959 EXPORT_SYMBOL_GPL(_torture_stop_kthread);
960
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