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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 * Author: Paul E. McKenney <paulmck@us.ibm.com>
21 * Based on kernel/rcu/torture.c.
22 */
23#include <linux/types.h>
24#include <linux/kernel.h>
25#include <linux/init.h>
26#include <linux/module.h>
27#include <linux/kthread.h>
28#include <linux/err.h>
29#include <linux/spinlock.h>
30#include <linux/smp.h>
31#include <linux/interrupt.h>
32#include <linux/sched.h>
33#include <linux/atomic.h>
34#include <linux/bitops.h>
35#include <linux/completion.h>
36#include <linux/moduleparam.h>
37#include <linux/percpu.h>
38#include <linux/notifier.h>
39#include <linux/reboot.h>
40#include <linux/freezer.h>
41#include <linux/cpu.h>
42#include <linux/delay.h>
43#include <linux/stat.h>
44#include <linux/slab.h>
45#include <linux/trace_clock.h>
46#include <asm/byteorder.h>
47#include <linux/torture.h>
48
49MODULE_LICENSE("GPL");
50MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com>");
51
52torture_param(int, nwriters_stress, -1,
53 "Number of write-locking stress-test threads");
54torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)");
55torture_param(int, onoff_interval, 0,
56 "Time between CPU hotplugs (s), 0=disable");
57torture_param(int, shuffle_interval, 3,
58 "Number of jiffies between shuffles, 0=disable");
59torture_param(int, shutdown_secs, 0, "Shutdown time (j), <= zero to disable.");
60torture_param(int, stat_interval, 60,
61 "Number of seconds between stats printk()s");
62torture_param(int, stutter, 5, "Number of jiffies to run/halt test, 0=disable");
63torture_param(bool, verbose, true,
64 "Enable verbose debugging printk()s");
65
66static char *torture_type = "spin_lock";
67module_param(torture_type, charp, 0444);
68MODULE_PARM_DESC(torture_type,
69 "Type of lock to torture (spin_lock, spin_lock_irq, ...)");
70
71static atomic_t n_lock_torture_errors;
72
73static struct task_struct *stats_task;
74static struct task_struct **writer_tasks;
75
76static int nrealwriters_stress;
77static bool lock_is_write_held;
78
79struct lock_writer_stress_stats {
80 long n_write_lock_fail;
81 long n_write_lock_acquired;
82};
83static struct lock_writer_stress_stats *lwsa;
84
85#if defined(MODULE) || defined(CONFIG_LOCK_TORTURE_TEST_RUNNABLE)
86#define LOCKTORTURE_RUNNABLE_INIT 1
87#else
88#define LOCKTORTURE_RUNNABLE_INIT 0
89#endif
90int locktorture_runnable = LOCKTORTURE_RUNNABLE_INIT;
91module_param(locktorture_runnable, int, 0444);
92MODULE_PARM_DESC(locktorture_runnable, "Start locktorture at boot");
93
94/* Forward reference. */
95static void lock_torture_cleanup(void);
96
97/*
98 * Operations vector for selecting different types of tests.
99 */
100struct lock_torture_ops {
101 void (*init)(void);
102 int (*writelock)(void);
103 void (*write_delay)(struct torture_random_state *trsp);
104 void (*writeunlock)(void);
105 unsigned long flags;
106 const char *name;
107};
108
109static struct lock_torture_ops *cur_ops;
110
111/*
112 * Definitions for lock torture testing.
113 */
114
115static int torture_lock_busted_write_lock(void)
116{
117 return 0; /* BUGGY, do not use in real life!!! */
118}
119
120static void torture_lock_busted_write_delay(struct torture_random_state *trsp)
121{
122 const unsigned long longdelay_us = 100;
123
124 /* We want a long delay occasionally to force massive contention. */
125 if (!(torture_random(trsp) %
126 (nrealwriters_stress * 2000 * longdelay_us)))
127 mdelay(longdelay_us);
128#ifdef CONFIG_PREEMPT
129 if (!(torture_random(trsp) % (nrealwriters_stress * 20000)))
130 preempt_schedule(); /* Allow test to be preempted. */
131#endif
132}
133
134static void torture_lock_busted_write_unlock(void)
135{
136 /* BUGGY, do not use in real life!!! */
137}
138
139static struct lock_torture_ops lock_busted_ops = {
140 .writelock = torture_lock_busted_write_lock,
141 .write_delay = torture_lock_busted_write_delay,
142 .writeunlock = torture_lock_busted_write_unlock,
143 .name = "lock_busted"
144};
145
146static DEFINE_SPINLOCK(torture_spinlock);
147
148static int torture_spin_lock_write_lock(void) __acquires(torture_spinlock)
149{
150 spin_lock(&torture_spinlock);
151 return 0;
152}
153
154static void torture_spin_lock_write_delay(struct torture_random_state *trsp)
155{
156 const unsigned long shortdelay_us = 2;
157 const unsigned long longdelay_us = 100;
158
159 /* We want a short delay mostly to emulate likely code, and
160 * we want a long delay occasionally to force massive contention.
161 */
162 if (!(torture_random(trsp) %
163 (nrealwriters_stress * 2000 * longdelay_us)))
164 mdelay(longdelay_us);
165 if (!(torture_random(trsp) %
166 (nrealwriters_stress * 2 * shortdelay_us)))
167 udelay(shortdelay_us);
168#ifdef CONFIG_PREEMPT
169 if (!(torture_random(trsp) % (nrealwriters_stress * 20000)))
170 preempt_schedule(); /* Allow test to be preempted. */
171#endif
172}
173
174static void torture_spin_lock_write_unlock(void) __releases(torture_spinlock)
175{
176 spin_unlock(&torture_spinlock);
177}
178
179static struct lock_torture_ops spin_lock_ops = {
180 .writelock = torture_spin_lock_write_lock,
181 .write_delay = torture_spin_lock_write_delay,
182 .writeunlock = torture_spin_lock_write_unlock,
183 .name = "spin_lock"
184};
185
186static int torture_spin_lock_write_lock_irq(void)
187__acquires(torture_spinlock_irq)
188{
189 unsigned long flags;
190
191 spin_lock_irqsave(&torture_spinlock, flags);
192 cur_ops->flags = flags;
193 return 0;
194}
195
196static void torture_lock_spin_write_unlock_irq(void)
197__releases(torture_spinlock)
198{
199 spin_unlock_irqrestore(&torture_spinlock, cur_ops->flags);
200}
201
202static struct lock_torture_ops spin_lock_irq_ops = {
203 .writelock = torture_spin_lock_write_lock_irq,
204 .write_delay = torture_spin_lock_write_delay,
205 .writeunlock = torture_lock_spin_write_unlock_irq,
206 .name = "spin_lock_irq"
207};
208
209/*
210 * Lock torture writer kthread. Repeatedly acquires and releases
211 * the lock, checking for duplicate acquisitions.
212 */
213static int lock_torture_writer(void *arg)
214{
215 struct lock_writer_stress_stats *lwsp = arg;
216 static DEFINE_TORTURE_RANDOM(rand);
217
218 VERBOSE_TOROUT_STRING("lock_torture_writer task started");
219 set_user_nice(current, 19);
220
221 do {
222 schedule_timeout_uninterruptible(1);
223 cur_ops->writelock();
224 if (WARN_ON_ONCE(lock_is_write_held))
225 lwsp->n_write_lock_fail++;
226 lock_is_write_held = 1;
227 lwsp->n_write_lock_acquired++;
228 cur_ops->write_delay(&rand);
229 lock_is_write_held = 0;
230 cur_ops->writeunlock();
231 stutter_wait("lock_torture_writer");
232 } while (!torture_must_stop());
233 torture_kthread_stopping("lock_torture_writer");
234 return 0;
235}
236
237/*
238 * Create an lock-torture-statistics message in the specified buffer.
239 */
240static void lock_torture_printk(char *page)
241{
242 bool fail = 0;
243 int i;
244 long max = 0;
245 long min = lwsa[0].n_write_lock_acquired;
246 long long sum = 0;
247
248 for (i = 0; i < nrealwriters_stress; i++) {
249 if (lwsa[i].n_write_lock_fail)
250 fail = true;
251 sum += lwsa[i].n_write_lock_acquired;
252 if (max < lwsa[i].n_write_lock_fail)
253 max = lwsa[i].n_write_lock_fail;
254 if (min > lwsa[i].n_write_lock_fail)
255 min = lwsa[i].n_write_lock_fail;
256 }
257 page += sprintf(page, "%s%s ", torture_type, TORTURE_FLAG);
258 page += sprintf(page,
259 "Writes: Total: %lld Max/Min: %ld/%ld %s Fail: %d %s\n",
260 sum, max, min, max / 2 > min ? "???" : "",
261 fail, fail ? "!!!" : "");
262 if (fail)
263 atomic_inc(&n_lock_torture_errors);
264}
265
266/*
267 * Print torture statistics. Caller must ensure that there is only one
268 * call to this function at a given time!!! This is normally accomplished
269 * by relying on the module system to only have one copy of the module
270 * loaded, and then by giving the lock_torture_stats kthread full control
271 * (or the init/cleanup functions when lock_torture_stats thread is not
272 * running).
273 */
274static void lock_torture_stats_print(void)
275{
276 int size = nrealwriters_stress * 200 + 8192;
277 char *buf;
278
279 buf = kmalloc(size, GFP_KERNEL);
280 if (!buf) {
281 pr_err("lock_torture_stats_print: Out of memory, need: %d",
282 size);
283 return;
284 }
285 lock_torture_printk(buf);
286 pr_alert("%s", buf);
287 kfree(buf);
288}
289
290/*
291 * Periodically prints torture statistics, if periodic statistics printing
292 * was specified via the stat_interval module parameter.
293 *
294 * No need to worry about fullstop here, since this one doesn't reference
295 * volatile state or register callbacks.
296 */
297static int lock_torture_stats(void *arg)
298{
299 VERBOSE_TOROUT_STRING("lock_torture_stats task started");
300 do {
301 schedule_timeout_interruptible(stat_interval * HZ);
302 lock_torture_stats_print();
303 torture_shutdown_absorb("lock_torture_stats");
304 } while (!torture_must_stop());
305 torture_kthread_stopping("lock_torture_stats");
306 return 0;
307}
308
309static inline void
310lock_torture_print_module_parms(struct lock_torture_ops *cur_ops,
311 const char *tag)
312{
313 pr_alert("%s" TORTURE_FLAG
314 "--- %s: nwriters_stress=%d stat_interval=%d verbose=%d shuffle_interval=%d stutter=%d shutdown_secs=%d onoff_interval=%d onoff_holdoff=%d\n",
315 torture_type, tag, nrealwriters_stress, stat_interval, verbose,
316 shuffle_interval, stutter, shutdown_secs,
317 onoff_interval, onoff_holdoff);
318}
319
320static void lock_torture_cleanup(void)
321{
322 int i;
323
324 if (torture_cleanup())
325 return;
326
327 if (writer_tasks) {
328 for (i = 0; i < nrealwriters_stress; i++)
329 torture_stop_kthread(lock_torture_writer,
330 writer_tasks[i]);
331 kfree(writer_tasks);
332 writer_tasks = NULL;
333 }
334
335 torture_stop_kthread(lock_torture_stats, stats_task);
336 lock_torture_stats_print(); /* -After- the stats thread is stopped! */
337
338 if (atomic_read(&n_lock_torture_errors))
339 lock_torture_print_module_parms(cur_ops,
340 "End of test: FAILURE");
341 else if (torture_onoff_failures())
342 lock_torture_print_module_parms(cur_ops,
343 "End of test: LOCK_HOTPLUG");
344 else
345 lock_torture_print_module_parms(cur_ops,
346 "End of test: SUCCESS");
347}
348
349static int __init lock_torture_init(void)
350{
351 int i;
352 int firsterr = 0;
353 static struct lock_torture_ops *torture_ops[] = {
354 &lock_busted_ops, &spin_lock_ops, &spin_lock_irq_ops,
355 };
356
357 torture_init_begin(torture_type, verbose, &locktorture_runnable);
358
359 /* Process args and tell the world that the torturer is on the job. */
360 for (i = 0; i < ARRAY_SIZE(torture_ops); i++) {
361 cur_ops = torture_ops[i];
362 if (strcmp(torture_type, cur_ops->name) == 0)
363 break;
364 }
365 if (i == ARRAY_SIZE(torture_ops)) {
366 pr_alert("lock-torture: invalid torture type: \"%s\"\n",
367 torture_type);
368 pr_alert("lock-torture types:");
369 for (i = 0; i < ARRAY_SIZE(torture_ops); i++)
370 pr_alert(" %s", torture_ops[i]->name);
371 pr_alert("\n");
372 torture_init_end();
373 return -EINVAL;
374 }
375 if (cur_ops->init)
376 cur_ops->init(); /* no "goto unwind" prior to this point!!! */
377
378 if (nwriters_stress >= 0)
379 nrealwriters_stress = nwriters_stress;
380 else
381 nrealwriters_stress = 2 * num_online_cpus();
382 lock_torture_print_module_parms(cur_ops, "Start of test");
383
384 /* Initialize the statistics so that each run gets its own numbers. */
385
386 lock_is_write_held = 0;
387 lwsa = kmalloc(sizeof(*lwsa) * nrealwriters_stress, GFP_KERNEL);
388 if (lwsa == NULL) {
389 VERBOSE_TOROUT_STRING("lwsa: Out of memory");
390 firsterr = -ENOMEM;
391 goto unwind;
392 }
393 for (i = 0; i < nrealwriters_stress; i++) {
394 lwsa[i].n_write_lock_fail = 0;
395 lwsa[i].n_write_lock_acquired = 0;
396 }
397
398 /* Start up the kthreads. */
399
400 if (onoff_interval > 0) {
401 firsterr = torture_onoff_init(onoff_holdoff * HZ,
402 onoff_interval * HZ);
403 if (firsterr)
404 goto unwind;
405 }
406 if (shuffle_interval > 0) {
407 firsterr = torture_shuffle_init(shuffle_interval);
408 if (firsterr)
409 goto unwind;
410 }
411 if (shutdown_secs > 0) {
412 firsterr = torture_shutdown_init(shutdown_secs,
413 lock_torture_cleanup);
414 if (firsterr)
415 goto unwind;
416 }
417 if (stutter > 0) {
418 firsterr = torture_stutter_init(stutter);
419 if (firsterr)
420 goto unwind;
421 }
422
423 writer_tasks = kzalloc(nrealwriters_stress * sizeof(writer_tasks[0]),
424 GFP_KERNEL);
425 if (writer_tasks == NULL) {
426 VERBOSE_TOROUT_ERRSTRING("writer_tasks: Out of memory");
427 firsterr = -ENOMEM;
428 goto unwind;
429 }
430 for (i = 0; i < nrealwriters_stress; i++) {
431 firsterr = torture_create_kthread(lock_torture_writer, &lwsa[i],
432 writer_tasks[i]);
433 if (firsterr)
434 goto unwind;
435 }
436 if (stat_interval > 0) {
437 firsterr = torture_create_kthread(lock_torture_stats, NULL,
438 stats_task);
439 if (firsterr)
440 goto unwind;
441 }
442 torture_init_end();
443 return 0;
444
445unwind:
446 torture_init_end();
447 lock_torture_cleanup();
448 return firsterr;
449}
450
451module_init(lock_torture_init);
452module_exit(lock_torture_cleanup);
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Module-based torture test facility for locking
4 *
5 * Copyright (C) IBM Corporation, 2014
6 *
7 * Authors: Paul E. McKenney <paulmck@linux.ibm.com>
8 * Davidlohr Bueso <dave@stgolabs.net>
9 * Based on kernel/rcu/torture.c.
10 */
11
12#define pr_fmt(fmt) fmt
13
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/kthread.h>
17#include <linux/sched/rt.h>
18#include <linux/spinlock.h>
19#include <linux/mutex.h>
20#include <linux/rwsem.h>
21#include <linux/smp.h>
22#include <linux/interrupt.h>
23#include <linux/sched.h>
24#include <uapi/linux/sched/types.h>
25#include <linux/rtmutex.h>
26#include <linux/atomic.h>
27#include <linux/moduleparam.h>
28#include <linux/delay.h>
29#include <linux/slab.h>
30#include <linux/torture.h>
31#include <linux/reboot.h>
32
33MODULE_LICENSE("GPL");
34MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com>");
35
36torture_param(int, nwriters_stress, -1,
37 "Number of write-locking stress-test threads");
38torture_param(int, nreaders_stress, -1,
39 "Number of read-locking stress-test threads");
40torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)");
41torture_param(int, onoff_interval, 0,
42 "Time between CPU hotplugs (s), 0=disable");
43torture_param(int, shuffle_interval, 3,
44 "Number of jiffies between shuffles, 0=disable");
45torture_param(int, shutdown_secs, 0, "Shutdown time (j), <= zero to disable.");
46torture_param(int, stat_interval, 60,
47 "Number of seconds between stats printk()s");
48torture_param(int, stutter, 5, "Number of jiffies to run/halt test, 0=disable");
49torture_param(int, verbose, 1,
50 "Enable verbose debugging printk()s");
51
52static char *torture_type = "spin_lock";
53module_param(torture_type, charp, 0444);
54MODULE_PARM_DESC(torture_type,
55 "Type of lock to torture (spin_lock, spin_lock_irq, mutex_lock, ...)");
56
57static struct task_struct *stats_task;
58static struct task_struct **writer_tasks;
59static struct task_struct **reader_tasks;
60
61static bool lock_is_write_held;
62static bool lock_is_read_held;
63static unsigned long last_lock_release;
64
65struct lock_stress_stats {
66 long n_lock_fail;
67 long n_lock_acquired;
68};
69
70/* Forward reference. */
71static void lock_torture_cleanup(void);
72
73/*
74 * Operations vector for selecting different types of tests.
75 */
76struct lock_torture_ops {
77 void (*init)(void);
78 void (*exit)(void);
79 int (*writelock)(int tid);
80 void (*write_delay)(struct torture_random_state *trsp);
81 void (*task_boost)(struct torture_random_state *trsp);
82 void (*writeunlock)(int tid);
83 int (*readlock)(int tid);
84 void (*read_delay)(struct torture_random_state *trsp);
85 void (*readunlock)(int tid);
86
87 unsigned long flags; /* for irq spinlocks */
88 const char *name;
89};
90
91struct lock_torture_cxt {
92 int nrealwriters_stress;
93 int nrealreaders_stress;
94 bool debug_lock;
95 bool init_called;
96 atomic_t n_lock_torture_errors;
97 struct lock_torture_ops *cur_ops;
98 struct lock_stress_stats *lwsa; /* writer statistics */
99 struct lock_stress_stats *lrsa; /* reader statistics */
100};
101static struct lock_torture_cxt cxt = { 0, 0, false, false,
102 ATOMIC_INIT(0),
103 NULL, NULL};
104/*
105 * Definitions for lock torture testing.
106 */
107
108static int torture_lock_busted_write_lock(int tid __maybe_unused)
109{
110 return 0; /* BUGGY, do not use in real life!!! */
111}
112
113static void torture_lock_busted_write_delay(struct torture_random_state *trsp)
114{
115 const unsigned long longdelay_ms = 100;
116
117 /* We want a long delay occasionally to force massive contention. */
118 if (!(torture_random(trsp) %
119 (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
120 mdelay(longdelay_ms);
121 if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
122 torture_preempt_schedule(); /* Allow test to be preempted. */
123}
124
125static void torture_lock_busted_write_unlock(int tid __maybe_unused)
126{
127 /* BUGGY, do not use in real life!!! */
128}
129
130static void torture_boost_dummy(struct torture_random_state *trsp)
131{
132 /* Only rtmutexes care about priority */
133}
134
135static struct lock_torture_ops lock_busted_ops = {
136 .writelock = torture_lock_busted_write_lock,
137 .write_delay = torture_lock_busted_write_delay,
138 .task_boost = torture_boost_dummy,
139 .writeunlock = torture_lock_busted_write_unlock,
140 .readlock = NULL,
141 .read_delay = NULL,
142 .readunlock = NULL,
143 .name = "lock_busted"
144};
145
146static DEFINE_SPINLOCK(torture_spinlock);
147
148static int torture_spin_lock_write_lock(int tid __maybe_unused)
149__acquires(torture_spinlock)
150{
151 spin_lock(&torture_spinlock);
152 return 0;
153}
154
155static void torture_spin_lock_write_delay(struct torture_random_state *trsp)
156{
157 const unsigned long shortdelay_us = 2;
158 const unsigned long longdelay_ms = 100;
159
160 /* We want a short delay mostly to emulate likely code, and
161 * we want a long delay occasionally to force massive contention.
162 */
163 if (!(torture_random(trsp) %
164 (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
165 mdelay(longdelay_ms);
166 if (!(torture_random(trsp) %
167 (cxt.nrealwriters_stress * 2 * shortdelay_us)))
168 udelay(shortdelay_us);
169 if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
170 torture_preempt_schedule(); /* Allow test to be preempted. */
171}
172
173static void torture_spin_lock_write_unlock(int tid __maybe_unused)
174__releases(torture_spinlock)
175{
176 spin_unlock(&torture_spinlock);
177}
178
179static struct lock_torture_ops spin_lock_ops = {
180 .writelock = torture_spin_lock_write_lock,
181 .write_delay = torture_spin_lock_write_delay,
182 .task_boost = torture_boost_dummy,
183 .writeunlock = torture_spin_lock_write_unlock,
184 .readlock = NULL,
185 .read_delay = NULL,
186 .readunlock = NULL,
187 .name = "spin_lock"
188};
189
190static int torture_spin_lock_write_lock_irq(int tid __maybe_unused)
191__acquires(torture_spinlock)
192{
193 unsigned long flags;
194
195 spin_lock_irqsave(&torture_spinlock, flags);
196 cxt.cur_ops->flags = flags;
197 return 0;
198}
199
200static void torture_lock_spin_write_unlock_irq(int tid __maybe_unused)
201__releases(torture_spinlock)
202{
203 spin_unlock_irqrestore(&torture_spinlock, cxt.cur_ops->flags);
204}
205
206static struct lock_torture_ops spin_lock_irq_ops = {
207 .writelock = torture_spin_lock_write_lock_irq,
208 .write_delay = torture_spin_lock_write_delay,
209 .task_boost = torture_boost_dummy,
210 .writeunlock = torture_lock_spin_write_unlock_irq,
211 .readlock = NULL,
212 .read_delay = NULL,
213 .readunlock = NULL,
214 .name = "spin_lock_irq"
215};
216
217static DEFINE_RWLOCK(torture_rwlock);
218
219static int torture_rwlock_write_lock(int tid __maybe_unused)
220__acquires(torture_rwlock)
221{
222 write_lock(&torture_rwlock);
223 return 0;
224}
225
226static void torture_rwlock_write_delay(struct torture_random_state *trsp)
227{
228 const unsigned long shortdelay_us = 2;
229 const unsigned long longdelay_ms = 100;
230
231 /* We want a short delay mostly to emulate likely code, and
232 * we want a long delay occasionally to force massive contention.
233 */
234 if (!(torture_random(trsp) %
235 (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
236 mdelay(longdelay_ms);
237 else
238 udelay(shortdelay_us);
239}
240
241static void torture_rwlock_write_unlock(int tid __maybe_unused)
242__releases(torture_rwlock)
243{
244 write_unlock(&torture_rwlock);
245}
246
247static int torture_rwlock_read_lock(int tid __maybe_unused)
248__acquires(torture_rwlock)
249{
250 read_lock(&torture_rwlock);
251 return 0;
252}
253
254static void torture_rwlock_read_delay(struct torture_random_state *trsp)
255{
256 const unsigned long shortdelay_us = 10;
257 const unsigned long longdelay_ms = 100;
258
259 /* We want a short delay mostly to emulate likely code, and
260 * we want a long delay occasionally to force massive contention.
261 */
262 if (!(torture_random(trsp) %
263 (cxt.nrealreaders_stress * 2000 * longdelay_ms)))
264 mdelay(longdelay_ms);
265 else
266 udelay(shortdelay_us);
267}
268
269static void torture_rwlock_read_unlock(int tid __maybe_unused)
270__releases(torture_rwlock)
271{
272 read_unlock(&torture_rwlock);
273}
274
275static struct lock_torture_ops rw_lock_ops = {
276 .writelock = torture_rwlock_write_lock,
277 .write_delay = torture_rwlock_write_delay,
278 .task_boost = torture_boost_dummy,
279 .writeunlock = torture_rwlock_write_unlock,
280 .readlock = torture_rwlock_read_lock,
281 .read_delay = torture_rwlock_read_delay,
282 .readunlock = torture_rwlock_read_unlock,
283 .name = "rw_lock"
284};
285
286static int torture_rwlock_write_lock_irq(int tid __maybe_unused)
287__acquires(torture_rwlock)
288{
289 unsigned long flags;
290
291 write_lock_irqsave(&torture_rwlock, flags);
292 cxt.cur_ops->flags = flags;
293 return 0;
294}
295
296static void torture_rwlock_write_unlock_irq(int tid __maybe_unused)
297__releases(torture_rwlock)
298{
299 write_unlock_irqrestore(&torture_rwlock, cxt.cur_ops->flags);
300}
301
302static int torture_rwlock_read_lock_irq(int tid __maybe_unused)
303__acquires(torture_rwlock)
304{
305 unsigned long flags;
306
307 read_lock_irqsave(&torture_rwlock, flags);
308 cxt.cur_ops->flags = flags;
309 return 0;
310}
311
312static void torture_rwlock_read_unlock_irq(int tid __maybe_unused)
313__releases(torture_rwlock)
314{
315 read_unlock_irqrestore(&torture_rwlock, cxt.cur_ops->flags);
316}
317
318static struct lock_torture_ops rw_lock_irq_ops = {
319 .writelock = torture_rwlock_write_lock_irq,
320 .write_delay = torture_rwlock_write_delay,
321 .task_boost = torture_boost_dummy,
322 .writeunlock = torture_rwlock_write_unlock_irq,
323 .readlock = torture_rwlock_read_lock_irq,
324 .read_delay = torture_rwlock_read_delay,
325 .readunlock = torture_rwlock_read_unlock_irq,
326 .name = "rw_lock_irq"
327};
328
329static DEFINE_MUTEX(torture_mutex);
330
331static int torture_mutex_lock(int tid __maybe_unused)
332__acquires(torture_mutex)
333{
334 mutex_lock(&torture_mutex);
335 return 0;
336}
337
338static void torture_mutex_delay(struct torture_random_state *trsp)
339{
340 const unsigned long longdelay_ms = 100;
341
342 /* We want a long delay occasionally to force massive contention. */
343 if (!(torture_random(trsp) %
344 (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
345 mdelay(longdelay_ms * 5);
346 else
347 mdelay(longdelay_ms / 5);
348 if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
349 torture_preempt_schedule(); /* Allow test to be preempted. */
350}
351
352static void torture_mutex_unlock(int tid __maybe_unused)
353__releases(torture_mutex)
354{
355 mutex_unlock(&torture_mutex);
356}
357
358static struct lock_torture_ops mutex_lock_ops = {
359 .writelock = torture_mutex_lock,
360 .write_delay = torture_mutex_delay,
361 .task_boost = torture_boost_dummy,
362 .writeunlock = torture_mutex_unlock,
363 .readlock = NULL,
364 .read_delay = NULL,
365 .readunlock = NULL,
366 .name = "mutex_lock"
367};
368
369#include <linux/ww_mutex.h>
370/*
371 * The torture ww_mutexes should belong to the same lock class as
372 * torture_ww_class to avoid lockdep problem. The ww_mutex_init()
373 * function is called for initialization to ensure that.
374 */
375static DEFINE_WD_CLASS(torture_ww_class);
376static struct ww_mutex torture_ww_mutex_0, torture_ww_mutex_1, torture_ww_mutex_2;
377static struct ww_acquire_ctx *ww_acquire_ctxs;
378
379static void torture_ww_mutex_init(void)
380{
381 ww_mutex_init(&torture_ww_mutex_0, &torture_ww_class);
382 ww_mutex_init(&torture_ww_mutex_1, &torture_ww_class);
383 ww_mutex_init(&torture_ww_mutex_2, &torture_ww_class);
384
385 ww_acquire_ctxs = kmalloc_array(cxt.nrealwriters_stress,
386 sizeof(*ww_acquire_ctxs),
387 GFP_KERNEL);
388 if (!ww_acquire_ctxs)
389 VERBOSE_TOROUT_STRING("ww_acquire_ctx: Out of memory");
390}
391
392static void torture_ww_mutex_exit(void)
393{
394 kfree(ww_acquire_ctxs);
395}
396
397static int torture_ww_mutex_lock(int tid)
398__acquires(torture_ww_mutex_0)
399__acquires(torture_ww_mutex_1)
400__acquires(torture_ww_mutex_2)
401{
402 LIST_HEAD(list);
403 struct reorder_lock {
404 struct list_head link;
405 struct ww_mutex *lock;
406 } locks[3], *ll, *ln;
407 struct ww_acquire_ctx *ctx = &ww_acquire_ctxs[tid];
408
409 locks[0].lock = &torture_ww_mutex_0;
410 list_add(&locks[0].link, &list);
411
412 locks[1].lock = &torture_ww_mutex_1;
413 list_add(&locks[1].link, &list);
414
415 locks[2].lock = &torture_ww_mutex_2;
416 list_add(&locks[2].link, &list);
417
418 ww_acquire_init(ctx, &torture_ww_class);
419
420 list_for_each_entry(ll, &list, link) {
421 int err;
422
423 err = ww_mutex_lock(ll->lock, ctx);
424 if (!err)
425 continue;
426
427 ln = ll;
428 list_for_each_entry_continue_reverse(ln, &list, link)
429 ww_mutex_unlock(ln->lock);
430
431 if (err != -EDEADLK)
432 return err;
433
434 ww_mutex_lock_slow(ll->lock, ctx);
435 list_move(&ll->link, &list);
436 }
437
438 return 0;
439}
440
441static void torture_ww_mutex_unlock(int tid)
442__releases(torture_ww_mutex_0)
443__releases(torture_ww_mutex_1)
444__releases(torture_ww_mutex_2)
445{
446 struct ww_acquire_ctx *ctx = &ww_acquire_ctxs[tid];
447
448 ww_mutex_unlock(&torture_ww_mutex_0);
449 ww_mutex_unlock(&torture_ww_mutex_1);
450 ww_mutex_unlock(&torture_ww_mutex_2);
451 ww_acquire_fini(ctx);
452}
453
454static struct lock_torture_ops ww_mutex_lock_ops = {
455 .init = torture_ww_mutex_init,
456 .exit = torture_ww_mutex_exit,
457 .writelock = torture_ww_mutex_lock,
458 .write_delay = torture_mutex_delay,
459 .task_boost = torture_boost_dummy,
460 .writeunlock = torture_ww_mutex_unlock,
461 .readlock = NULL,
462 .read_delay = NULL,
463 .readunlock = NULL,
464 .name = "ww_mutex_lock"
465};
466
467#ifdef CONFIG_RT_MUTEXES
468static DEFINE_RT_MUTEX(torture_rtmutex);
469
470static int torture_rtmutex_lock(int tid __maybe_unused)
471__acquires(torture_rtmutex)
472{
473 rt_mutex_lock(&torture_rtmutex);
474 return 0;
475}
476
477static void torture_rtmutex_boost(struct torture_random_state *trsp)
478{
479 const unsigned int factor = 50000; /* yes, quite arbitrary */
480
481 if (!rt_task(current)) {
482 /*
483 * Boost priority once every ~50k operations. When the
484 * task tries to take the lock, the rtmutex it will account
485 * for the new priority, and do any corresponding pi-dance.
486 */
487 if (trsp && !(torture_random(trsp) %
488 (cxt.nrealwriters_stress * factor))) {
489 sched_set_fifo(current);
490 } else /* common case, do nothing */
491 return;
492 } else {
493 /*
494 * The task will remain boosted for another ~500k operations,
495 * then restored back to its original prio, and so forth.
496 *
497 * When @trsp is nil, we want to force-reset the task for
498 * stopping the kthread.
499 */
500 if (!trsp || !(torture_random(trsp) %
501 (cxt.nrealwriters_stress * factor * 2))) {
502 sched_set_normal(current, 0);
503 } else /* common case, do nothing */
504 return;
505 }
506}
507
508static void torture_rtmutex_delay(struct torture_random_state *trsp)
509{
510 const unsigned long shortdelay_us = 2;
511 const unsigned long longdelay_ms = 100;
512
513 /*
514 * We want a short delay mostly to emulate likely code, and
515 * we want a long delay occasionally to force massive contention.
516 */
517 if (!(torture_random(trsp) %
518 (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
519 mdelay(longdelay_ms);
520 if (!(torture_random(trsp) %
521 (cxt.nrealwriters_stress * 2 * shortdelay_us)))
522 udelay(shortdelay_us);
523 if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
524 torture_preempt_schedule(); /* Allow test to be preempted. */
525}
526
527static void torture_rtmutex_unlock(int tid __maybe_unused)
528__releases(torture_rtmutex)
529{
530 rt_mutex_unlock(&torture_rtmutex);
531}
532
533static struct lock_torture_ops rtmutex_lock_ops = {
534 .writelock = torture_rtmutex_lock,
535 .write_delay = torture_rtmutex_delay,
536 .task_boost = torture_rtmutex_boost,
537 .writeunlock = torture_rtmutex_unlock,
538 .readlock = NULL,
539 .read_delay = NULL,
540 .readunlock = NULL,
541 .name = "rtmutex_lock"
542};
543#endif
544
545static DECLARE_RWSEM(torture_rwsem);
546static int torture_rwsem_down_write(int tid __maybe_unused)
547__acquires(torture_rwsem)
548{
549 down_write(&torture_rwsem);
550 return 0;
551}
552
553static void torture_rwsem_write_delay(struct torture_random_state *trsp)
554{
555 const unsigned long longdelay_ms = 100;
556
557 /* We want a long delay occasionally to force massive contention. */
558 if (!(torture_random(trsp) %
559 (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
560 mdelay(longdelay_ms * 10);
561 else
562 mdelay(longdelay_ms / 10);
563 if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
564 torture_preempt_schedule(); /* Allow test to be preempted. */
565}
566
567static void torture_rwsem_up_write(int tid __maybe_unused)
568__releases(torture_rwsem)
569{
570 up_write(&torture_rwsem);
571}
572
573static int torture_rwsem_down_read(int tid __maybe_unused)
574__acquires(torture_rwsem)
575{
576 down_read(&torture_rwsem);
577 return 0;
578}
579
580static void torture_rwsem_read_delay(struct torture_random_state *trsp)
581{
582 const unsigned long longdelay_ms = 100;
583
584 /* We want a long delay occasionally to force massive contention. */
585 if (!(torture_random(trsp) %
586 (cxt.nrealreaders_stress * 2000 * longdelay_ms)))
587 mdelay(longdelay_ms * 2);
588 else
589 mdelay(longdelay_ms / 2);
590 if (!(torture_random(trsp) % (cxt.nrealreaders_stress * 20000)))
591 torture_preempt_schedule(); /* Allow test to be preempted. */
592}
593
594static void torture_rwsem_up_read(int tid __maybe_unused)
595__releases(torture_rwsem)
596{
597 up_read(&torture_rwsem);
598}
599
600static struct lock_torture_ops rwsem_lock_ops = {
601 .writelock = torture_rwsem_down_write,
602 .write_delay = torture_rwsem_write_delay,
603 .task_boost = torture_boost_dummy,
604 .writeunlock = torture_rwsem_up_write,
605 .readlock = torture_rwsem_down_read,
606 .read_delay = torture_rwsem_read_delay,
607 .readunlock = torture_rwsem_up_read,
608 .name = "rwsem_lock"
609};
610
611#include <linux/percpu-rwsem.h>
612static struct percpu_rw_semaphore pcpu_rwsem;
613
614static void torture_percpu_rwsem_init(void)
615{
616 BUG_ON(percpu_init_rwsem(&pcpu_rwsem));
617}
618
619static void torture_percpu_rwsem_exit(void)
620{
621 percpu_free_rwsem(&pcpu_rwsem);
622}
623
624static int torture_percpu_rwsem_down_write(int tid __maybe_unused)
625__acquires(pcpu_rwsem)
626{
627 percpu_down_write(&pcpu_rwsem);
628 return 0;
629}
630
631static void torture_percpu_rwsem_up_write(int tid __maybe_unused)
632__releases(pcpu_rwsem)
633{
634 percpu_up_write(&pcpu_rwsem);
635}
636
637static int torture_percpu_rwsem_down_read(int tid __maybe_unused)
638__acquires(pcpu_rwsem)
639{
640 percpu_down_read(&pcpu_rwsem);
641 return 0;
642}
643
644static void torture_percpu_rwsem_up_read(int tid __maybe_unused)
645__releases(pcpu_rwsem)
646{
647 percpu_up_read(&pcpu_rwsem);
648}
649
650static struct lock_torture_ops percpu_rwsem_lock_ops = {
651 .init = torture_percpu_rwsem_init,
652 .exit = torture_percpu_rwsem_exit,
653 .writelock = torture_percpu_rwsem_down_write,
654 .write_delay = torture_rwsem_write_delay,
655 .task_boost = torture_boost_dummy,
656 .writeunlock = torture_percpu_rwsem_up_write,
657 .readlock = torture_percpu_rwsem_down_read,
658 .read_delay = torture_rwsem_read_delay,
659 .readunlock = torture_percpu_rwsem_up_read,
660 .name = "percpu_rwsem_lock"
661};
662
663/*
664 * Lock torture writer kthread. Repeatedly acquires and releases
665 * the lock, checking for duplicate acquisitions.
666 */
667static int lock_torture_writer(void *arg)
668{
669 struct lock_stress_stats *lwsp = arg;
670 int tid = lwsp - cxt.lwsa;
671 DEFINE_TORTURE_RANDOM(rand);
672
673 VERBOSE_TOROUT_STRING("lock_torture_writer task started");
674 set_user_nice(current, MAX_NICE);
675
676 do {
677 if ((torture_random(&rand) & 0xfffff) == 0)
678 schedule_timeout_uninterruptible(1);
679
680 cxt.cur_ops->task_boost(&rand);
681 cxt.cur_ops->writelock(tid);
682 if (WARN_ON_ONCE(lock_is_write_held))
683 lwsp->n_lock_fail++;
684 lock_is_write_held = true;
685 if (WARN_ON_ONCE(lock_is_read_held))
686 lwsp->n_lock_fail++; /* rare, but... */
687
688 lwsp->n_lock_acquired++;
689 cxt.cur_ops->write_delay(&rand);
690 lock_is_write_held = false;
691 WRITE_ONCE(last_lock_release, jiffies);
692 cxt.cur_ops->writeunlock(tid);
693
694 stutter_wait("lock_torture_writer");
695 } while (!torture_must_stop());
696
697 cxt.cur_ops->task_boost(NULL); /* reset prio */
698 torture_kthread_stopping("lock_torture_writer");
699 return 0;
700}
701
702/*
703 * Lock torture reader kthread. Repeatedly acquires and releases
704 * the reader lock.
705 */
706static int lock_torture_reader(void *arg)
707{
708 struct lock_stress_stats *lrsp = arg;
709 int tid = lrsp - cxt.lrsa;
710 DEFINE_TORTURE_RANDOM(rand);
711
712 VERBOSE_TOROUT_STRING("lock_torture_reader task started");
713 set_user_nice(current, MAX_NICE);
714
715 do {
716 if ((torture_random(&rand) & 0xfffff) == 0)
717 schedule_timeout_uninterruptible(1);
718
719 cxt.cur_ops->readlock(tid);
720 lock_is_read_held = true;
721 if (WARN_ON_ONCE(lock_is_write_held))
722 lrsp->n_lock_fail++; /* rare, but... */
723
724 lrsp->n_lock_acquired++;
725 cxt.cur_ops->read_delay(&rand);
726 lock_is_read_held = false;
727 cxt.cur_ops->readunlock(tid);
728
729 stutter_wait("lock_torture_reader");
730 } while (!torture_must_stop());
731 torture_kthread_stopping("lock_torture_reader");
732 return 0;
733}
734
735/*
736 * Create an lock-torture-statistics message in the specified buffer.
737 */
738static void __torture_print_stats(char *page,
739 struct lock_stress_stats *statp, bool write)
740{
741 bool fail = false;
742 int i, n_stress;
743 long max = 0, min = statp ? statp[0].n_lock_acquired : 0;
744 long long sum = 0;
745
746 n_stress = write ? cxt.nrealwriters_stress : cxt.nrealreaders_stress;
747 for (i = 0; i < n_stress; i++) {
748 if (statp[i].n_lock_fail)
749 fail = true;
750 sum += statp[i].n_lock_acquired;
751 if (max < statp[i].n_lock_acquired)
752 max = statp[i].n_lock_acquired;
753 if (min > statp[i].n_lock_acquired)
754 min = statp[i].n_lock_acquired;
755 }
756 page += sprintf(page,
757 "%s: Total: %lld Max/Min: %ld/%ld %s Fail: %d %s\n",
758 write ? "Writes" : "Reads ",
759 sum, max, min,
760 !onoff_interval && max / 2 > min ? "???" : "",
761 fail, fail ? "!!!" : "");
762 if (fail)
763 atomic_inc(&cxt.n_lock_torture_errors);
764}
765
766/*
767 * Print torture statistics. Caller must ensure that there is only one
768 * call to this function at a given time!!! This is normally accomplished
769 * by relying on the module system to only have one copy of the module
770 * loaded, and then by giving the lock_torture_stats kthread full control
771 * (or the init/cleanup functions when lock_torture_stats thread is not
772 * running).
773 */
774static void lock_torture_stats_print(void)
775{
776 int size = cxt.nrealwriters_stress * 200 + 8192;
777 char *buf;
778
779 if (cxt.cur_ops->readlock)
780 size += cxt.nrealreaders_stress * 200 + 8192;
781
782 buf = kmalloc(size, GFP_KERNEL);
783 if (!buf) {
784 pr_err("lock_torture_stats_print: Out of memory, need: %d",
785 size);
786 return;
787 }
788
789 __torture_print_stats(buf, cxt.lwsa, true);
790 pr_alert("%s", buf);
791 kfree(buf);
792
793 if (cxt.cur_ops->readlock) {
794 buf = kmalloc(size, GFP_KERNEL);
795 if (!buf) {
796 pr_err("lock_torture_stats_print: Out of memory, need: %d",
797 size);
798 return;
799 }
800
801 __torture_print_stats(buf, cxt.lrsa, false);
802 pr_alert("%s", buf);
803 kfree(buf);
804 }
805}
806
807/*
808 * Periodically prints torture statistics, if periodic statistics printing
809 * was specified via the stat_interval module parameter.
810 *
811 * No need to worry about fullstop here, since this one doesn't reference
812 * volatile state or register callbacks.
813 */
814static int lock_torture_stats(void *arg)
815{
816 VERBOSE_TOROUT_STRING("lock_torture_stats task started");
817 do {
818 schedule_timeout_interruptible(stat_interval * HZ);
819 lock_torture_stats_print();
820 torture_shutdown_absorb("lock_torture_stats");
821 } while (!torture_must_stop());
822 torture_kthread_stopping("lock_torture_stats");
823 return 0;
824}
825
826static inline void
827lock_torture_print_module_parms(struct lock_torture_ops *cur_ops,
828 const char *tag)
829{
830 pr_alert("%s" TORTURE_FLAG
831 "--- %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",
832 torture_type, tag, cxt.debug_lock ? " [debug]": "",
833 cxt.nrealwriters_stress, cxt.nrealreaders_stress, stat_interval,
834 verbose, shuffle_interval, stutter, shutdown_secs,
835 onoff_interval, onoff_holdoff);
836}
837
838static void lock_torture_cleanup(void)
839{
840 int i;
841
842 if (torture_cleanup_begin())
843 return;
844
845 /*
846 * Indicates early cleanup, meaning that the test has not run,
847 * such as when passing bogus args when loading the module.
848 * However cxt->cur_ops.init() may have been invoked, so beside
849 * perform the underlying torture-specific cleanups, cur_ops.exit()
850 * will be invoked if needed.
851 */
852 if (!cxt.lwsa && !cxt.lrsa)
853 goto end;
854
855 if (writer_tasks) {
856 for (i = 0; i < cxt.nrealwriters_stress; i++)
857 torture_stop_kthread(lock_torture_writer,
858 writer_tasks[i]);
859 kfree(writer_tasks);
860 writer_tasks = NULL;
861 }
862
863 if (reader_tasks) {
864 for (i = 0; i < cxt.nrealreaders_stress; i++)
865 torture_stop_kthread(lock_torture_reader,
866 reader_tasks[i]);
867 kfree(reader_tasks);
868 reader_tasks = NULL;
869 }
870
871 torture_stop_kthread(lock_torture_stats, stats_task);
872 lock_torture_stats_print(); /* -After- the stats thread is stopped! */
873
874 if (atomic_read(&cxt.n_lock_torture_errors))
875 lock_torture_print_module_parms(cxt.cur_ops,
876 "End of test: FAILURE");
877 else if (torture_onoff_failures())
878 lock_torture_print_module_parms(cxt.cur_ops,
879 "End of test: LOCK_HOTPLUG");
880 else
881 lock_torture_print_module_parms(cxt.cur_ops,
882 "End of test: SUCCESS");
883
884 kfree(cxt.lwsa);
885 cxt.lwsa = NULL;
886 kfree(cxt.lrsa);
887 cxt.lrsa = NULL;
888
889end:
890 if (cxt.init_called) {
891 if (cxt.cur_ops->exit)
892 cxt.cur_ops->exit();
893 cxt.init_called = false;
894 }
895 torture_cleanup_end();
896}
897
898static int __init lock_torture_init(void)
899{
900 int i, j;
901 int firsterr = 0;
902 static struct lock_torture_ops *torture_ops[] = {
903 &lock_busted_ops,
904 &spin_lock_ops, &spin_lock_irq_ops,
905 &rw_lock_ops, &rw_lock_irq_ops,
906 &mutex_lock_ops,
907 &ww_mutex_lock_ops,
908#ifdef CONFIG_RT_MUTEXES
909 &rtmutex_lock_ops,
910#endif
911 &rwsem_lock_ops,
912 &percpu_rwsem_lock_ops,
913 };
914
915 if (!torture_init_begin(torture_type, verbose))
916 return -EBUSY;
917
918 /* Process args and tell the world that the torturer is on the job. */
919 for (i = 0; i < ARRAY_SIZE(torture_ops); i++) {
920 cxt.cur_ops = torture_ops[i];
921 if (strcmp(torture_type, cxt.cur_ops->name) == 0)
922 break;
923 }
924 if (i == ARRAY_SIZE(torture_ops)) {
925 pr_alert("lock-torture: invalid torture type: \"%s\"\n",
926 torture_type);
927 pr_alert("lock-torture types:");
928 for (i = 0; i < ARRAY_SIZE(torture_ops); i++)
929 pr_alert(" %s", torture_ops[i]->name);
930 pr_alert("\n");
931 firsterr = -EINVAL;
932 goto unwind;
933 }
934
935 if (nwriters_stress == 0 &&
936 (!cxt.cur_ops->readlock || nreaders_stress == 0)) {
937 pr_alert("lock-torture: must run at least one locking thread\n");
938 firsterr = -EINVAL;
939 goto unwind;
940 }
941
942 if (nwriters_stress >= 0)
943 cxt.nrealwriters_stress = nwriters_stress;
944 else
945 cxt.nrealwriters_stress = 2 * num_online_cpus();
946
947 if (cxt.cur_ops->init) {
948 cxt.cur_ops->init();
949 cxt.init_called = true;
950 }
951
952#ifdef CONFIG_DEBUG_MUTEXES
953 if (str_has_prefix(torture_type, "mutex"))
954 cxt.debug_lock = true;
955#endif
956#ifdef CONFIG_DEBUG_RT_MUTEXES
957 if (str_has_prefix(torture_type, "rtmutex"))
958 cxt.debug_lock = true;
959#endif
960#ifdef CONFIG_DEBUG_SPINLOCK
961 if ((str_has_prefix(torture_type, "spin")) ||
962 (str_has_prefix(torture_type, "rw_lock")))
963 cxt.debug_lock = true;
964#endif
965
966 /* Initialize the statistics so that each run gets its own numbers. */
967 if (nwriters_stress) {
968 lock_is_write_held = false;
969 cxt.lwsa = kmalloc_array(cxt.nrealwriters_stress,
970 sizeof(*cxt.lwsa),
971 GFP_KERNEL);
972 if (cxt.lwsa == NULL) {
973 VERBOSE_TOROUT_STRING("cxt.lwsa: Out of memory");
974 firsterr = -ENOMEM;
975 goto unwind;
976 }
977
978 for (i = 0; i < cxt.nrealwriters_stress; i++) {
979 cxt.lwsa[i].n_lock_fail = 0;
980 cxt.lwsa[i].n_lock_acquired = 0;
981 }
982 }
983
984 if (cxt.cur_ops->readlock) {
985 if (nreaders_stress >= 0)
986 cxt.nrealreaders_stress = nreaders_stress;
987 else {
988 /*
989 * By default distribute evenly the number of
990 * readers and writers. We still run the same number
991 * of threads as the writer-only locks default.
992 */
993 if (nwriters_stress < 0) /* user doesn't care */
994 cxt.nrealwriters_stress = num_online_cpus();
995 cxt.nrealreaders_stress = cxt.nrealwriters_stress;
996 }
997
998 if (nreaders_stress) {
999 lock_is_read_held = false;
1000 cxt.lrsa = kmalloc_array(cxt.nrealreaders_stress,
1001 sizeof(*cxt.lrsa),
1002 GFP_KERNEL);
1003 if (cxt.lrsa == NULL) {
1004 VERBOSE_TOROUT_STRING("cxt.lrsa: Out of memory");
1005 firsterr = -ENOMEM;
1006 kfree(cxt.lwsa);
1007 cxt.lwsa = NULL;
1008 goto unwind;
1009 }
1010
1011 for (i = 0; i < cxt.nrealreaders_stress; i++) {
1012 cxt.lrsa[i].n_lock_fail = 0;
1013 cxt.lrsa[i].n_lock_acquired = 0;
1014 }
1015 }
1016 }
1017
1018 lock_torture_print_module_parms(cxt.cur_ops, "Start of test");
1019
1020 /* Prepare torture context. */
1021 if (onoff_interval > 0) {
1022 firsterr = torture_onoff_init(onoff_holdoff * HZ,
1023 onoff_interval * HZ, NULL);
1024 if (firsterr)
1025 goto unwind;
1026 }
1027 if (shuffle_interval > 0) {
1028 firsterr = torture_shuffle_init(shuffle_interval);
1029 if (firsterr)
1030 goto unwind;
1031 }
1032 if (shutdown_secs > 0) {
1033 firsterr = torture_shutdown_init(shutdown_secs,
1034 lock_torture_cleanup);
1035 if (firsterr)
1036 goto unwind;
1037 }
1038 if (stutter > 0) {
1039 firsterr = torture_stutter_init(stutter, stutter);
1040 if (firsterr)
1041 goto unwind;
1042 }
1043
1044 if (nwriters_stress) {
1045 writer_tasks = kcalloc(cxt.nrealwriters_stress,
1046 sizeof(writer_tasks[0]),
1047 GFP_KERNEL);
1048 if (writer_tasks == NULL) {
1049 VERBOSE_TOROUT_ERRSTRING("writer_tasks: Out of memory");
1050 firsterr = -ENOMEM;
1051 goto unwind;
1052 }
1053 }
1054
1055 if (cxt.cur_ops->readlock) {
1056 reader_tasks = kcalloc(cxt.nrealreaders_stress,
1057 sizeof(reader_tasks[0]),
1058 GFP_KERNEL);
1059 if (reader_tasks == NULL) {
1060 VERBOSE_TOROUT_ERRSTRING("reader_tasks: Out of memory");
1061 kfree(writer_tasks);
1062 writer_tasks = NULL;
1063 firsterr = -ENOMEM;
1064 goto unwind;
1065 }
1066 }
1067
1068 /*
1069 * Create the kthreads and start torturing (oh, those poor little locks).
1070 *
1071 * TODO: Note that we interleave writers with readers, giving writers a
1072 * slight advantage, by creating its kthread first. This can be modified
1073 * for very specific needs, or even let the user choose the policy, if
1074 * ever wanted.
1075 */
1076 for (i = 0, j = 0; i < cxt.nrealwriters_stress ||
1077 j < cxt.nrealreaders_stress; i++, j++) {
1078 if (i >= cxt.nrealwriters_stress)
1079 goto create_reader;
1080
1081 /* Create writer. */
1082 firsterr = torture_create_kthread(lock_torture_writer, &cxt.lwsa[i],
1083 writer_tasks[i]);
1084 if (firsterr)
1085 goto unwind;
1086
1087 create_reader:
1088 if (cxt.cur_ops->readlock == NULL || (j >= cxt.nrealreaders_stress))
1089 continue;
1090 /* Create reader. */
1091 firsterr = torture_create_kthread(lock_torture_reader, &cxt.lrsa[j],
1092 reader_tasks[j]);
1093 if (firsterr)
1094 goto unwind;
1095 }
1096 if (stat_interval > 0) {
1097 firsterr = torture_create_kthread(lock_torture_stats, NULL,
1098 stats_task);
1099 if (firsterr)
1100 goto unwind;
1101 }
1102 torture_init_end();
1103 return 0;
1104
1105unwind:
1106 torture_init_end();
1107 lock_torture_cleanup();
1108 if (shutdown_secs) {
1109 WARN_ON(!IS_MODULE(CONFIG_LOCK_TORTURE_TEST));
1110 kernel_power_off();
1111 }
1112 return firsterr;
1113}
1114
1115module_init(lock_torture_init);
1116module_exit(lock_torture_cleanup);