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1/*
2 * Module-based torture test facility for locking
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, you can access it online at
16 * http://www.gnu.org/licenses/gpl-2.0.html.
17 *
18 * Copyright (C) IBM Corporation, 2014
19 *
20 * Authors: Paul E. McKenney <paulmck@us.ibm.com>
21 * Davidlohr Bueso <dave@stgolabs.net>
22 * Based on kernel/rcu/torture.c.
23 */
24#include <linux/kernel.h>
25#include <linux/module.h>
26#include <linux/kthread.h>
27#include <linux/sched/rt.h>
28#include <linux/spinlock.h>
29#include <linux/rwlock.h>
30#include <linux/mutex.h>
31#include <linux/rwsem.h>
32#include <linux/smp.h>
33#include <linux/interrupt.h>
34#include <linux/sched.h>
35#include <linux/atomic.h>
36#include <linux/moduleparam.h>
37#include <linux/delay.h>
38#include <linux/slab.h>
39#include <linux/percpu-rwsem.h>
40#include <linux/torture.h>
41
42MODULE_LICENSE("GPL");
43MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com>");
44
45torture_param(int, nwriters_stress, -1,
46 "Number of write-locking stress-test threads");
47torture_param(int, nreaders_stress, -1,
48 "Number of read-locking stress-test threads");
49torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)");
50torture_param(int, onoff_interval, 0,
51 "Time between CPU hotplugs (s), 0=disable");
52torture_param(int, shuffle_interval, 3,
53 "Number of jiffies between shuffles, 0=disable");
54torture_param(int, shutdown_secs, 0, "Shutdown time (j), <= zero to disable.");
55torture_param(int, stat_interval, 60,
56 "Number of seconds between stats printk()s");
57torture_param(int, stutter, 5, "Number of jiffies to run/halt test, 0=disable");
58torture_param(bool, verbose, true,
59 "Enable verbose debugging printk()s");
60
61static char *torture_type = "spin_lock";
62module_param(torture_type, charp, 0444);
63MODULE_PARM_DESC(torture_type,
64 "Type of lock to torture (spin_lock, spin_lock_irq, mutex_lock, ...)");
65
66static struct task_struct *stats_task;
67static struct task_struct **writer_tasks;
68static struct task_struct **reader_tasks;
69
70static bool lock_is_write_held;
71static bool lock_is_read_held;
72
73struct lock_stress_stats {
74 long n_lock_fail;
75 long n_lock_acquired;
76};
77
78#if defined(MODULE)
79#define LOCKTORTURE_RUNNABLE_INIT 1
80#else
81#define LOCKTORTURE_RUNNABLE_INIT 0
82#endif
83int torture_runnable = LOCKTORTURE_RUNNABLE_INIT;
84module_param(torture_runnable, int, 0444);
85MODULE_PARM_DESC(torture_runnable, "Start locktorture at module init");
86
87/* Forward reference. */
88static void lock_torture_cleanup(void);
89
90/*
91 * Operations vector for selecting different types of tests.
92 */
93struct lock_torture_ops {
94 void (*init)(void);
95 int (*writelock)(void);
96 void (*write_delay)(struct torture_random_state *trsp);
97 void (*task_boost)(struct torture_random_state *trsp);
98 void (*writeunlock)(void);
99 int (*readlock)(void);
100 void (*read_delay)(struct torture_random_state *trsp);
101 void (*readunlock)(void);
102
103 unsigned long flags; /* for irq spinlocks */
104 const char *name;
105};
106
107struct lock_torture_cxt {
108 int nrealwriters_stress;
109 int nrealreaders_stress;
110 bool debug_lock;
111 atomic_t n_lock_torture_errors;
112 struct lock_torture_ops *cur_ops;
113 struct lock_stress_stats *lwsa; /* writer statistics */
114 struct lock_stress_stats *lrsa; /* reader statistics */
115};
116static struct lock_torture_cxt cxt = { 0, 0, false,
117 ATOMIC_INIT(0),
118 NULL, NULL};
119/*
120 * Definitions for lock torture testing.
121 */
122
123static int torture_lock_busted_write_lock(void)
124{
125 return 0; /* BUGGY, do not use in real life!!! */
126}
127
128static void torture_lock_busted_write_delay(struct torture_random_state *trsp)
129{
130 const unsigned long longdelay_ms = 100;
131
132 /* We want a long delay occasionally to force massive contention. */
133 if (!(torture_random(trsp) %
134 (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
135 mdelay(longdelay_ms);
136#ifdef CONFIG_PREEMPT
137 if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
138 preempt_schedule(); /* Allow test to be preempted. */
139#endif
140}
141
142static void torture_lock_busted_write_unlock(void)
143{
144 /* BUGGY, do not use in real life!!! */
145}
146
147static void torture_boost_dummy(struct torture_random_state *trsp)
148{
149 /* Only rtmutexes care about priority */
150}
151
152static struct lock_torture_ops lock_busted_ops = {
153 .writelock = torture_lock_busted_write_lock,
154 .write_delay = torture_lock_busted_write_delay,
155 .task_boost = torture_boost_dummy,
156 .writeunlock = torture_lock_busted_write_unlock,
157 .readlock = NULL,
158 .read_delay = NULL,
159 .readunlock = NULL,
160 .name = "lock_busted"
161};
162
163static DEFINE_SPINLOCK(torture_spinlock);
164
165static int torture_spin_lock_write_lock(void) __acquires(torture_spinlock)
166{
167 spin_lock(&torture_spinlock);
168 return 0;
169}
170
171static void torture_spin_lock_write_delay(struct torture_random_state *trsp)
172{
173 const unsigned long shortdelay_us = 2;
174 const unsigned long longdelay_ms = 100;
175
176 /* We want a short delay mostly to emulate likely code, and
177 * we want a long delay occasionally to force massive contention.
178 */
179 if (!(torture_random(trsp) %
180 (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
181 mdelay(longdelay_ms);
182 if (!(torture_random(trsp) %
183 (cxt.nrealwriters_stress * 2 * shortdelay_us)))
184 udelay(shortdelay_us);
185#ifdef CONFIG_PREEMPT
186 if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
187 preempt_schedule(); /* Allow test to be preempted. */
188#endif
189}
190
191static void torture_spin_lock_write_unlock(void) __releases(torture_spinlock)
192{
193 spin_unlock(&torture_spinlock);
194}
195
196static struct lock_torture_ops spin_lock_ops = {
197 .writelock = torture_spin_lock_write_lock,
198 .write_delay = torture_spin_lock_write_delay,
199 .task_boost = torture_boost_dummy,
200 .writeunlock = torture_spin_lock_write_unlock,
201 .readlock = NULL,
202 .read_delay = NULL,
203 .readunlock = NULL,
204 .name = "spin_lock"
205};
206
207static int torture_spin_lock_write_lock_irq(void)
208__acquires(torture_spinlock)
209{
210 unsigned long flags;
211
212 spin_lock_irqsave(&torture_spinlock, flags);
213 cxt.cur_ops->flags = flags;
214 return 0;
215}
216
217static void torture_lock_spin_write_unlock_irq(void)
218__releases(torture_spinlock)
219{
220 spin_unlock_irqrestore(&torture_spinlock, cxt.cur_ops->flags);
221}
222
223static struct lock_torture_ops spin_lock_irq_ops = {
224 .writelock = torture_spin_lock_write_lock_irq,
225 .write_delay = torture_spin_lock_write_delay,
226 .task_boost = torture_boost_dummy,
227 .writeunlock = torture_lock_spin_write_unlock_irq,
228 .readlock = NULL,
229 .read_delay = NULL,
230 .readunlock = NULL,
231 .name = "spin_lock_irq"
232};
233
234static DEFINE_RWLOCK(torture_rwlock);
235
236static int torture_rwlock_write_lock(void) __acquires(torture_rwlock)
237{
238 write_lock(&torture_rwlock);
239 return 0;
240}
241
242static void torture_rwlock_write_delay(struct torture_random_state *trsp)
243{
244 const unsigned long shortdelay_us = 2;
245 const unsigned long longdelay_ms = 100;
246
247 /* We want a short delay mostly to emulate likely code, and
248 * we want a long delay occasionally to force massive contention.
249 */
250 if (!(torture_random(trsp) %
251 (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
252 mdelay(longdelay_ms);
253 else
254 udelay(shortdelay_us);
255}
256
257static void torture_rwlock_write_unlock(void) __releases(torture_rwlock)
258{
259 write_unlock(&torture_rwlock);
260}
261
262static int torture_rwlock_read_lock(void) __acquires(torture_rwlock)
263{
264 read_lock(&torture_rwlock);
265 return 0;
266}
267
268static void torture_rwlock_read_delay(struct torture_random_state *trsp)
269{
270 const unsigned long shortdelay_us = 10;
271 const unsigned long longdelay_ms = 100;
272
273 /* We want a short delay mostly to emulate likely code, and
274 * we want a long delay occasionally to force massive contention.
275 */
276 if (!(torture_random(trsp) %
277 (cxt.nrealreaders_stress * 2000 * longdelay_ms)))
278 mdelay(longdelay_ms);
279 else
280 udelay(shortdelay_us);
281}
282
283static void torture_rwlock_read_unlock(void) __releases(torture_rwlock)
284{
285 read_unlock(&torture_rwlock);
286}
287
288static struct lock_torture_ops rw_lock_ops = {
289 .writelock = torture_rwlock_write_lock,
290 .write_delay = torture_rwlock_write_delay,
291 .task_boost = torture_boost_dummy,
292 .writeunlock = torture_rwlock_write_unlock,
293 .readlock = torture_rwlock_read_lock,
294 .read_delay = torture_rwlock_read_delay,
295 .readunlock = torture_rwlock_read_unlock,
296 .name = "rw_lock"
297};
298
299static int torture_rwlock_write_lock_irq(void) __acquires(torture_rwlock)
300{
301 unsigned long flags;
302
303 write_lock_irqsave(&torture_rwlock, flags);
304 cxt.cur_ops->flags = flags;
305 return 0;
306}
307
308static void torture_rwlock_write_unlock_irq(void)
309__releases(torture_rwlock)
310{
311 write_unlock_irqrestore(&torture_rwlock, cxt.cur_ops->flags);
312}
313
314static int torture_rwlock_read_lock_irq(void) __acquires(torture_rwlock)
315{
316 unsigned long flags;
317
318 read_lock_irqsave(&torture_rwlock, flags);
319 cxt.cur_ops->flags = flags;
320 return 0;
321}
322
323static void torture_rwlock_read_unlock_irq(void)
324__releases(torture_rwlock)
325{
326 read_unlock_irqrestore(&torture_rwlock, cxt.cur_ops->flags);
327}
328
329static struct lock_torture_ops rw_lock_irq_ops = {
330 .writelock = torture_rwlock_write_lock_irq,
331 .write_delay = torture_rwlock_write_delay,
332 .task_boost = torture_boost_dummy,
333 .writeunlock = torture_rwlock_write_unlock_irq,
334 .readlock = torture_rwlock_read_lock_irq,
335 .read_delay = torture_rwlock_read_delay,
336 .readunlock = torture_rwlock_read_unlock_irq,
337 .name = "rw_lock_irq"
338};
339
340static DEFINE_MUTEX(torture_mutex);
341
342static int torture_mutex_lock(void) __acquires(torture_mutex)
343{
344 mutex_lock(&torture_mutex);
345 return 0;
346}
347
348static void torture_mutex_delay(struct torture_random_state *trsp)
349{
350 const unsigned long longdelay_ms = 100;
351
352 /* We want a long delay occasionally to force massive contention. */
353 if (!(torture_random(trsp) %
354 (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
355 mdelay(longdelay_ms * 5);
356 else
357 mdelay(longdelay_ms / 5);
358#ifdef CONFIG_PREEMPT
359 if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
360 preempt_schedule(); /* Allow test to be preempted. */
361#endif
362}
363
364static void torture_mutex_unlock(void) __releases(torture_mutex)
365{
366 mutex_unlock(&torture_mutex);
367}
368
369static struct lock_torture_ops mutex_lock_ops = {
370 .writelock = torture_mutex_lock,
371 .write_delay = torture_mutex_delay,
372 .task_boost = torture_boost_dummy,
373 .writeunlock = torture_mutex_unlock,
374 .readlock = NULL,
375 .read_delay = NULL,
376 .readunlock = NULL,
377 .name = "mutex_lock"
378};
379
380#ifdef CONFIG_RT_MUTEXES
381static DEFINE_RT_MUTEX(torture_rtmutex);
382
383static int torture_rtmutex_lock(void) __acquires(torture_rtmutex)
384{
385 rt_mutex_lock(&torture_rtmutex);
386 return 0;
387}
388
389static void torture_rtmutex_boost(struct torture_random_state *trsp)
390{
391 int policy;
392 struct sched_param param;
393 const unsigned int factor = 50000; /* yes, quite arbitrary */
394
395 if (!rt_task(current)) {
396 /*
397 * (1) Boost priority once every ~50k operations. When the
398 * task tries to take the lock, the rtmutex it will account
399 * for the new priority, and do any corresponding pi-dance.
400 */
401 if (!(torture_random(trsp) %
402 (cxt.nrealwriters_stress * factor))) {
403 policy = SCHED_FIFO;
404 param.sched_priority = MAX_RT_PRIO - 1;
405 } else /* common case, do nothing */
406 return;
407 } else {
408 /*
409 * The task will remain boosted for another ~500k operations,
410 * then restored back to its original prio, and so forth.
411 *
412 * When @trsp is nil, we want to force-reset the task for
413 * stopping the kthread.
414 */
415 if (!trsp || !(torture_random(trsp) %
416 (cxt.nrealwriters_stress * factor * 2))) {
417 policy = SCHED_NORMAL;
418 param.sched_priority = 0;
419 } else /* common case, do nothing */
420 return;
421 }
422
423 sched_setscheduler_nocheck(current, policy, ¶m);
424}
425
426static void torture_rtmutex_delay(struct torture_random_state *trsp)
427{
428 const unsigned long shortdelay_us = 2;
429 const unsigned long longdelay_ms = 100;
430
431 /*
432 * We want a short delay mostly to emulate likely code, and
433 * we want a long delay occasionally to force massive contention.
434 */
435 if (!(torture_random(trsp) %
436 (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
437 mdelay(longdelay_ms);
438 if (!(torture_random(trsp) %
439 (cxt.nrealwriters_stress * 2 * shortdelay_us)))
440 udelay(shortdelay_us);
441#ifdef CONFIG_PREEMPT
442 if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
443 preempt_schedule(); /* Allow test to be preempted. */
444#endif
445}
446
447static void torture_rtmutex_unlock(void) __releases(torture_rtmutex)
448{
449 rt_mutex_unlock(&torture_rtmutex);
450}
451
452static struct lock_torture_ops rtmutex_lock_ops = {
453 .writelock = torture_rtmutex_lock,
454 .write_delay = torture_rtmutex_delay,
455 .task_boost = torture_rtmutex_boost,
456 .writeunlock = torture_rtmutex_unlock,
457 .readlock = NULL,
458 .read_delay = NULL,
459 .readunlock = NULL,
460 .name = "rtmutex_lock"
461};
462#endif
463
464static DECLARE_RWSEM(torture_rwsem);
465static int torture_rwsem_down_write(void) __acquires(torture_rwsem)
466{
467 down_write(&torture_rwsem);
468 return 0;
469}
470
471static void torture_rwsem_write_delay(struct torture_random_state *trsp)
472{
473 const unsigned long longdelay_ms = 100;
474
475 /* We want a long delay occasionally to force massive contention. */
476 if (!(torture_random(trsp) %
477 (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
478 mdelay(longdelay_ms * 10);
479 else
480 mdelay(longdelay_ms / 10);
481#ifdef CONFIG_PREEMPT
482 if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
483 preempt_schedule(); /* Allow test to be preempted. */
484#endif
485}
486
487static void torture_rwsem_up_write(void) __releases(torture_rwsem)
488{
489 up_write(&torture_rwsem);
490}
491
492static int torture_rwsem_down_read(void) __acquires(torture_rwsem)
493{
494 down_read(&torture_rwsem);
495 return 0;
496}
497
498static void torture_rwsem_read_delay(struct torture_random_state *trsp)
499{
500 const unsigned long longdelay_ms = 100;
501
502 /* We want a long delay occasionally to force massive contention. */
503 if (!(torture_random(trsp) %
504 (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
505 mdelay(longdelay_ms * 2);
506 else
507 mdelay(longdelay_ms / 2);
508#ifdef CONFIG_PREEMPT
509 if (!(torture_random(trsp) % (cxt.nrealreaders_stress * 20000)))
510 preempt_schedule(); /* Allow test to be preempted. */
511#endif
512}
513
514static void torture_rwsem_up_read(void) __releases(torture_rwsem)
515{
516 up_read(&torture_rwsem);
517}
518
519static struct lock_torture_ops rwsem_lock_ops = {
520 .writelock = torture_rwsem_down_write,
521 .write_delay = torture_rwsem_write_delay,
522 .task_boost = torture_boost_dummy,
523 .writeunlock = torture_rwsem_up_write,
524 .readlock = torture_rwsem_down_read,
525 .read_delay = torture_rwsem_read_delay,
526 .readunlock = torture_rwsem_up_read,
527 .name = "rwsem_lock"
528};
529
530#include <linux/percpu-rwsem.h>
531static struct percpu_rw_semaphore pcpu_rwsem;
532
533void torture_percpu_rwsem_init(void)
534{
535 BUG_ON(percpu_init_rwsem(&pcpu_rwsem));
536}
537
538static int torture_percpu_rwsem_down_write(void) __acquires(pcpu_rwsem)
539{
540 percpu_down_write(&pcpu_rwsem);
541 return 0;
542}
543
544static void torture_percpu_rwsem_up_write(void) __releases(pcpu_rwsem)
545{
546 percpu_up_write(&pcpu_rwsem);
547}
548
549static int torture_percpu_rwsem_down_read(void) __acquires(pcpu_rwsem)
550{
551 percpu_down_read(&pcpu_rwsem);
552 return 0;
553}
554
555static void torture_percpu_rwsem_up_read(void) __releases(pcpu_rwsem)
556{
557 percpu_up_read(&pcpu_rwsem);
558}
559
560static struct lock_torture_ops percpu_rwsem_lock_ops = {
561 .init = torture_percpu_rwsem_init,
562 .writelock = torture_percpu_rwsem_down_write,
563 .write_delay = torture_rwsem_write_delay,
564 .task_boost = torture_boost_dummy,
565 .writeunlock = torture_percpu_rwsem_up_write,
566 .readlock = torture_percpu_rwsem_down_read,
567 .read_delay = torture_rwsem_read_delay,
568 .readunlock = torture_percpu_rwsem_up_read,
569 .name = "percpu_rwsem_lock"
570};
571
572/*
573 * Lock torture writer kthread. Repeatedly acquires and releases
574 * the lock, checking for duplicate acquisitions.
575 */
576static int lock_torture_writer(void *arg)
577{
578 struct lock_stress_stats *lwsp = arg;
579 static DEFINE_TORTURE_RANDOM(rand);
580
581 VERBOSE_TOROUT_STRING("lock_torture_writer task started");
582 set_user_nice(current, MAX_NICE);
583
584 do {
585 if ((torture_random(&rand) & 0xfffff) == 0)
586 schedule_timeout_uninterruptible(1);
587
588 cxt.cur_ops->task_boost(&rand);
589 cxt.cur_ops->writelock();
590 if (WARN_ON_ONCE(lock_is_write_held))
591 lwsp->n_lock_fail++;
592 lock_is_write_held = 1;
593 if (WARN_ON_ONCE(lock_is_read_held))
594 lwsp->n_lock_fail++; /* rare, but... */
595
596 lwsp->n_lock_acquired++;
597 cxt.cur_ops->write_delay(&rand);
598 lock_is_write_held = 0;
599 cxt.cur_ops->writeunlock();
600
601 stutter_wait("lock_torture_writer");
602 } while (!torture_must_stop());
603
604 cxt.cur_ops->task_boost(NULL); /* reset prio */
605 torture_kthread_stopping("lock_torture_writer");
606 return 0;
607}
608
609/*
610 * Lock torture reader kthread. Repeatedly acquires and releases
611 * the reader lock.
612 */
613static int lock_torture_reader(void *arg)
614{
615 struct lock_stress_stats *lrsp = arg;
616 static DEFINE_TORTURE_RANDOM(rand);
617
618 VERBOSE_TOROUT_STRING("lock_torture_reader task started");
619 set_user_nice(current, MAX_NICE);
620
621 do {
622 if ((torture_random(&rand) & 0xfffff) == 0)
623 schedule_timeout_uninterruptible(1);
624
625 cxt.cur_ops->readlock();
626 lock_is_read_held = 1;
627 if (WARN_ON_ONCE(lock_is_write_held))
628 lrsp->n_lock_fail++; /* rare, but... */
629
630 lrsp->n_lock_acquired++;
631 cxt.cur_ops->read_delay(&rand);
632 lock_is_read_held = 0;
633 cxt.cur_ops->readunlock();
634
635 stutter_wait("lock_torture_reader");
636 } while (!torture_must_stop());
637 torture_kthread_stopping("lock_torture_reader");
638 return 0;
639}
640
641/*
642 * Create an lock-torture-statistics message in the specified buffer.
643 */
644static void __torture_print_stats(char *page,
645 struct lock_stress_stats *statp, bool write)
646{
647 bool fail = 0;
648 int i, n_stress;
649 long max = 0;
650 long min = statp[0].n_lock_acquired;
651 long long sum = 0;
652
653 n_stress = write ? cxt.nrealwriters_stress : cxt.nrealreaders_stress;
654 for (i = 0; i < n_stress; i++) {
655 if (statp[i].n_lock_fail)
656 fail = true;
657 sum += statp[i].n_lock_acquired;
658 if (max < statp[i].n_lock_fail)
659 max = statp[i].n_lock_fail;
660 if (min > statp[i].n_lock_fail)
661 min = statp[i].n_lock_fail;
662 }
663 page += sprintf(page,
664 "%s: Total: %lld Max/Min: %ld/%ld %s Fail: %d %s\n",
665 write ? "Writes" : "Reads ",
666 sum, max, min, max / 2 > min ? "???" : "",
667 fail, fail ? "!!!" : "");
668 if (fail)
669 atomic_inc(&cxt.n_lock_torture_errors);
670}
671
672/*
673 * Print torture statistics. Caller must ensure that there is only one
674 * call to this function at a given time!!! This is normally accomplished
675 * by relying on the module system to only have one copy of the module
676 * loaded, and then by giving the lock_torture_stats kthread full control
677 * (or the init/cleanup functions when lock_torture_stats thread is not
678 * running).
679 */
680static void lock_torture_stats_print(void)
681{
682 int size = cxt.nrealwriters_stress * 200 + 8192;
683 char *buf;
684
685 if (cxt.cur_ops->readlock)
686 size += cxt.nrealreaders_stress * 200 + 8192;
687
688 buf = kmalloc(size, GFP_KERNEL);
689 if (!buf) {
690 pr_err("lock_torture_stats_print: Out of memory, need: %d",
691 size);
692 return;
693 }
694
695 __torture_print_stats(buf, cxt.lwsa, true);
696 pr_alert("%s", buf);
697 kfree(buf);
698
699 if (cxt.cur_ops->readlock) {
700 buf = kmalloc(size, GFP_KERNEL);
701 if (!buf) {
702 pr_err("lock_torture_stats_print: Out of memory, need: %d",
703 size);
704 return;
705 }
706
707 __torture_print_stats(buf, cxt.lrsa, false);
708 pr_alert("%s", buf);
709 kfree(buf);
710 }
711}
712
713/*
714 * Periodically prints torture statistics, if periodic statistics printing
715 * was specified via the stat_interval module parameter.
716 *
717 * No need to worry about fullstop here, since this one doesn't reference
718 * volatile state or register callbacks.
719 */
720static int lock_torture_stats(void *arg)
721{
722 VERBOSE_TOROUT_STRING("lock_torture_stats task started");
723 do {
724 schedule_timeout_interruptible(stat_interval * HZ);
725 lock_torture_stats_print();
726 torture_shutdown_absorb("lock_torture_stats");
727 } while (!torture_must_stop());
728 torture_kthread_stopping("lock_torture_stats");
729 return 0;
730}
731
732static inline void
733lock_torture_print_module_parms(struct lock_torture_ops *cur_ops,
734 const char *tag)
735{
736 pr_alert("%s" TORTURE_FLAG
737 "--- %s%s: nwriters_stress=%d nreaders_stress=%d stat_interval=%d verbose=%d shuffle_interval=%d stutter=%d shutdown_secs=%d onoff_interval=%d onoff_holdoff=%d\n",
738 torture_type, tag, cxt.debug_lock ? " [debug]": "",
739 cxt.nrealwriters_stress, cxt.nrealreaders_stress, stat_interval,
740 verbose, shuffle_interval, stutter, shutdown_secs,
741 onoff_interval, onoff_holdoff);
742}
743
744static void lock_torture_cleanup(void)
745{
746 int i;
747
748 if (torture_cleanup_begin())
749 return;
750
751 if (writer_tasks) {
752 for (i = 0; i < cxt.nrealwriters_stress; i++)
753 torture_stop_kthread(lock_torture_writer,
754 writer_tasks[i]);
755 kfree(writer_tasks);
756 writer_tasks = NULL;
757 }
758
759 if (reader_tasks) {
760 for (i = 0; i < cxt.nrealreaders_stress; i++)
761 torture_stop_kthread(lock_torture_reader,
762 reader_tasks[i]);
763 kfree(reader_tasks);
764 reader_tasks = NULL;
765 }
766
767 torture_stop_kthread(lock_torture_stats, stats_task);
768 lock_torture_stats_print(); /* -After- the stats thread is stopped! */
769
770 if (atomic_read(&cxt.n_lock_torture_errors))
771 lock_torture_print_module_parms(cxt.cur_ops,
772 "End of test: FAILURE");
773 else if (torture_onoff_failures())
774 lock_torture_print_module_parms(cxt.cur_ops,
775 "End of test: LOCK_HOTPLUG");
776 else
777 lock_torture_print_module_parms(cxt.cur_ops,
778 "End of test: SUCCESS");
779 torture_cleanup_end();
780}
781
782static int __init lock_torture_init(void)
783{
784 int i, j;
785 int firsterr = 0;
786 static struct lock_torture_ops *torture_ops[] = {
787 &lock_busted_ops,
788 &spin_lock_ops, &spin_lock_irq_ops,
789 &rw_lock_ops, &rw_lock_irq_ops,
790 &mutex_lock_ops,
791#ifdef CONFIG_RT_MUTEXES
792 &rtmutex_lock_ops,
793#endif
794 &rwsem_lock_ops,
795 &percpu_rwsem_lock_ops,
796 };
797
798 if (!torture_init_begin(torture_type, verbose, &torture_runnable))
799 return -EBUSY;
800
801 /* Process args and tell the world that the torturer is on the job. */
802 for (i = 0; i < ARRAY_SIZE(torture_ops); i++) {
803 cxt.cur_ops = torture_ops[i];
804 if (strcmp(torture_type, cxt.cur_ops->name) == 0)
805 break;
806 }
807 if (i == ARRAY_SIZE(torture_ops)) {
808 pr_alert("lock-torture: invalid torture type: \"%s\"\n",
809 torture_type);
810 pr_alert("lock-torture types:");
811 for (i = 0; i < ARRAY_SIZE(torture_ops); i++)
812 pr_alert(" %s", torture_ops[i]->name);
813 pr_alert("\n");
814 firsterr = -EINVAL;
815 goto unwind;
816 }
817 if (cxt.cur_ops->init)
818 cxt.cur_ops->init();
819
820 if (nwriters_stress >= 0)
821 cxt.nrealwriters_stress = nwriters_stress;
822 else
823 cxt.nrealwriters_stress = 2 * num_online_cpus();
824
825#ifdef CONFIG_DEBUG_MUTEXES
826 if (strncmp(torture_type, "mutex", 5) == 0)
827 cxt.debug_lock = true;
828#endif
829#ifdef CONFIG_DEBUG_RT_MUTEXES
830 if (strncmp(torture_type, "rtmutex", 7) == 0)
831 cxt.debug_lock = true;
832#endif
833#ifdef CONFIG_DEBUG_SPINLOCK
834 if ((strncmp(torture_type, "spin", 4) == 0) ||
835 (strncmp(torture_type, "rw_lock", 7) == 0))
836 cxt.debug_lock = true;
837#endif
838
839 /* Initialize the statistics so that each run gets its own numbers. */
840
841 lock_is_write_held = 0;
842 cxt.lwsa = kmalloc(sizeof(*cxt.lwsa) * cxt.nrealwriters_stress, GFP_KERNEL);
843 if (cxt.lwsa == NULL) {
844 VERBOSE_TOROUT_STRING("cxt.lwsa: Out of memory");
845 firsterr = -ENOMEM;
846 goto unwind;
847 }
848 for (i = 0; i < cxt.nrealwriters_stress; i++) {
849 cxt.lwsa[i].n_lock_fail = 0;
850 cxt.lwsa[i].n_lock_acquired = 0;
851 }
852
853 if (cxt.cur_ops->readlock) {
854 if (nreaders_stress >= 0)
855 cxt.nrealreaders_stress = nreaders_stress;
856 else {
857 /*
858 * By default distribute evenly the number of
859 * readers and writers. We still run the same number
860 * of threads as the writer-only locks default.
861 */
862 if (nwriters_stress < 0) /* user doesn't care */
863 cxt.nrealwriters_stress = num_online_cpus();
864 cxt.nrealreaders_stress = cxt.nrealwriters_stress;
865 }
866
867 lock_is_read_held = 0;
868 cxt.lrsa = kmalloc(sizeof(*cxt.lrsa) * cxt.nrealreaders_stress, GFP_KERNEL);
869 if (cxt.lrsa == NULL) {
870 VERBOSE_TOROUT_STRING("cxt.lrsa: Out of memory");
871 firsterr = -ENOMEM;
872 kfree(cxt.lwsa);
873 goto unwind;
874 }
875
876 for (i = 0; i < cxt.nrealreaders_stress; i++) {
877 cxt.lrsa[i].n_lock_fail = 0;
878 cxt.lrsa[i].n_lock_acquired = 0;
879 }
880 }
881 lock_torture_print_module_parms(cxt.cur_ops, "Start of test");
882
883 /* Prepare torture context. */
884 if (onoff_interval > 0) {
885 firsterr = torture_onoff_init(onoff_holdoff * HZ,
886 onoff_interval * HZ);
887 if (firsterr)
888 goto unwind;
889 }
890 if (shuffle_interval > 0) {
891 firsterr = torture_shuffle_init(shuffle_interval);
892 if (firsterr)
893 goto unwind;
894 }
895 if (shutdown_secs > 0) {
896 firsterr = torture_shutdown_init(shutdown_secs,
897 lock_torture_cleanup);
898 if (firsterr)
899 goto unwind;
900 }
901 if (stutter > 0) {
902 firsterr = torture_stutter_init(stutter);
903 if (firsterr)
904 goto unwind;
905 }
906
907 writer_tasks = kzalloc(cxt.nrealwriters_stress * sizeof(writer_tasks[0]),
908 GFP_KERNEL);
909 if (writer_tasks == NULL) {
910 VERBOSE_TOROUT_ERRSTRING("writer_tasks: Out of memory");
911 firsterr = -ENOMEM;
912 goto unwind;
913 }
914
915 if (cxt.cur_ops->readlock) {
916 reader_tasks = kzalloc(cxt.nrealreaders_stress * sizeof(reader_tasks[0]),
917 GFP_KERNEL);
918 if (reader_tasks == NULL) {
919 VERBOSE_TOROUT_ERRSTRING("reader_tasks: Out of memory");
920 firsterr = -ENOMEM;
921 goto unwind;
922 }
923 }
924
925 /*
926 * Create the kthreads and start torturing (oh, those poor little locks).
927 *
928 * TODO: Note that we interleave writers with readers, giving writers a
929 * slight advantage, by creating its kthread first. This can be modified
930 * for very specific needs, or even let the user choose the policy, if
931 * ever wanted.
932 */
933 for (i = 0, j = 0; i < cxt.nrealwriters_stress ||
934 j < cxt.nrealreaders_stress; i++, j++) {
935 if (i >= cxt.nrealwriters_stress)
936 goto create_reader;
937
938 /* Create writer. */
939 firsterr = torture_create_kthread(lock_torture_writer, &cxt.lwsa[i],
940 writer_tasks[i]);
941 if (firsterr)
942 goto unwind;
943
944 create_reader:
945 if (cxt.cur_ops->readlock == NULL || (j >= cxt.nrealreaders_stress))
946 continue;
947 /* Create reader. */
948 firsterr = torture_create_kthread(lock_torture_reader, &cxt.lrsa[j],
949 reader_tasks[j]);
950 if (firsterr)
951 goto unwind;
952 }
953 if (stat_interval > 0) {
954 firsterr = torture_create_kthread(lock_torture_stats, NULL,
955 stats_task);
956 if (firsterr)
957 goto unwind;
958 }
959 torture_init_end();
960 return 0;
961
962unwind:
963 torture_init_end();
964 lock_torture_cleanup();
965 return firsterr;
966}
967
968module_init(lock_torture_init);
969module_exit(lock_torture_cleanup);