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0af3fe1e PM |
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> | |
42ddc75d | 30 | #include <linux/mutex.h> |
0af3fe1e PM |
31 | #include <linux/smp.h> |
32 | #include <linux/interrupt.h> | |
33 | #include <linux/sched.h> | |
34 | #include <linux/atomic.h> | |
35 | #include <linux/bitops.h> | |
36 | #include <linux/completion.h> | |
37 | #include <linux/moduleparam.h> | |
38 | #include <linux/percpu.h> | |
39 | #include <linux/notifier.h> | |
40 | #include <linux/reboot.h> | |
41 | #include <linux/freezer.h> | |
42 | #include <linux/cpu.h> | |
43 | #include <linux/delay.h> | |
44 | #include <linux/stat.h> | |
45 | #include <linux/slab.h> | |
46 | #include <linux/trace_clock.h> | |
47 | #include <asm/byteorder.h> | |
48 | #include <linux/torture.h> | |
49 | ||
50 | MODULE_LICENSE("GPL"); | |
51 | MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com>"); | |
52 | ||
53 | torture_param(int, nwriters_stress, -1, | |
54 | "Number of write-locking stress-test threads"); | |
55 | torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)"); | |
56 | torture_param(int, onoff_interval, 0, | |
57 | "Time between CPU hotplugs (s), 0=disable"); | |
58 | torture_param(int, shuffle_interval, 3, | |
59 | "Number of jiffies between shuffles, 0=disable"); | |
60 | torture_param(int, shutdown_secs, 0, "Shutdown time (j), <= zero to disable."); | |
61 | torture_param(int, stat_interval, 60, | |
62 | "Number of seconds between stats printk()s"); | |
63 | torture_param(int, stutter, 5, "Number of jiffies to run/halt test, 0=disable"); | |
64 | torture_param(bool, verbose, true, | |
65 | "Enable verbose debugging printk()s"); | |
66 | ||
f095bfc0 | 67 | static bool debug_lock = false; |
0af3fe1e PM |
68 | static char *torture_type = "spin_lock"; |
69 | module_param(torture_type, charp, 0444); | |
70 | MODULE_PARM_DESC(torture_type, | |
42ddc75d | 71 | "Type of lock to torture (spin_lock, spin_lock_irq, mutex_lock, ...)"); |
0af3fe1e PM |
72 | |
73 | static atomic_t n_lock_torture_errors; | |
74 | ||
75 | static struct task_struct *stats_task; | |
76 | static struct task_struct **writer_tasks; | |
77 | ||
78 | static int nrealwriters_stress; | |
79 | static bool lock_is_write_held; | |
80 | ||
1e6757a9 DB |
81 | struct lock_stress_stats { |
82 | long n_lock_fail; | |
83 | long n_lock_acquired; | |
0af3fe1e | 84 | }; |
1e6757a9 | 85 | static struct lock_stress_stats *lwsa; /* writer statistics */ |
0af3fe1e | 86 | |
d065eacf | 87 | #if defined(MODULE) |
0af3fe1e PM |
88 | #define LOCKTORTURE_RUNNABLE_INIT 1 |
89 | #else | |
90 | #define LOCKTORTURE_RUNNABLE_INIT 0 | |
91 | #endif | |
23a8e5c2 DB |
92 | int torture_runnable = LOCKTORTURE_RUNNABLE_INIT; |
93 | module_param(torture_runnable, int, 0444); | |
94 | MODULE_PARM_DESC(torture_runnable, "Start locktorture at module init"); | |
0af3fe1e PM |
95 | |
96 | /* Forward reference. */ | |
97 | static void lock_torture_cleanup(void); | |
98 | ||
99 | /* | |
100 | * Operations vector for selecting different types of tests. | |
101 | */ | |
102 | struct lock_torture_ops { | |
103 | void (*init)(void); | |
104 | int (*writelock)(void); | |
105 | void (*write_delay)(struct torture_random_state *trsp); | |
106 | void (*writeunlock)(void); | |
107 | unsigned long flags; | |
108 | const char *name; | |
109 | }; | |
110 | ||
111 | static struct lock_torture_ops *cur_ops; | |
112 | ||
113 | /* | |
114 | * Definitions for lock torture testing. | |
115 | */ | |
116 | ||
e086481b PM |
117 | static int torture_lock_busted_write_lock(void) |
118 | { | |
119 | return 0; /* BUGGY, do not use in real life!!! */ | |
120 | } | |
121 | ||
122 | static void torture_lock_busted_write_delay(struct torture_random_state *trsp) | |
123 | { | |
124 | const unsigned long longdelay_us = 100; | |
125 | ||
126 | /* We want a long delay occasionally to force massive contention. */ | |
127 | if (!(torture_random(trsp) % | |
128 | (nrealwriters_stress * 2000 * longdelay_us))) | |
129 | mdelay(longdelay_us); | |
130 | #ifdef CONFIG_PREEMPT | |
131 | if (!(torture_random(trsp) % (nrealwriters_stress * 20000))) | |
132 | preempt_schedule(); /* Allow test to be preempted. */ | |
133 | #endif | |
134 | } | |
135 | ||
136 | static void torture_lock_busted_write_unlock(void) | |
137 | { | |
138 | /* BUGGY, do not use in real life!!! */ | |
139 | } | |
140 | ||
141 | static struct lock_torture_ops lock_busted_ops = { | |
142 | .writelock = torture_lock_busted_write_lock, | |
143 | .write_delay = torture_lock_busted_write_delay, | |
144 | .writeunlock = torture_lock_busted_write_unlock, | |
145 | .name = "lock_busted" | |
146 | }; | |
147 | ||
0af3fe1e PM |
148 | static DEFINE_SPINLOCK(torture_spinlock); |
149 | ||
150 | static int torture_spin_lock_write_lock(void) __acquires(torture_spinlock) | |
151 | { | |
152 | spin_lock(&torture_spinlock); | |
153 | return 0; | |
154 | } | |
155 | ||
156 | static void torture_spin_lock_write_delay(struct torture_random_state *trsp) | |
157 | { | |
158 | const unsigned long shortdelay_us = 2; | |
159 | const unsigned long longdelay_us = 100; | |
160 | ||
161 | /* We want a short delay mostly to emulate likely code, and | |
162 | * we want a long delay occasionally to force massive contention. | |
163 | */ | |
164 | if (!(torture_random(trsp) % | |
165 | (nrealwriters_stress * 2000 * longdelay_us))) | |
166 | mdelay(longdelay_us); | |
167 | if (!(torture_random(trsp) % | |
168 | (nrealwriters_stress * 2 * shortdelay_us))) | |
169 | udelay(shortdelay_us); | |
170 | #ifdef CONFIG_PREEMPT | |
171 | if (!(torture_random(trsp) % (nrealwriters_stress * 20000))) | |
172 | preempt_schedule(); /* Allow test to be preempted. */ | |
173 | #endif | |
174 | } | |
175 | ||
176 | static void torture_spin_lock_write_unlock(void) __releases(torture_spinlock) | |
177 | { | |
178 | spin_unlock(&torture_spinlock); | |
179 | } | |
180 | ||
181 | static struct lock_torture_ops spin_lock_ops = { | |
182 | .writelock = torture_spin_lock_write_lock, | |
183 | .write_delay = torture_spin_lock_write_delay, | |
184 | .writeunlock = torture_spin_lock_write_unlock, | |
185 | .name = "spin_lock" | |
186 | }; | |
187 | ||
188 | static int torture_spin_lock_write_lock_irq(void) | |
189 | __acquires(torture_spinlock_irq) | |
190 | { | |
191 | unsigned long flags; | |
192 | ||
193 | spin_lock_irqsave(&torture_spinlock, flags); | |
194 | cur_ops->flags = flags; | |
195 | return 0; | |
196 | } | |
197 | ||
198 | static void torture_lock_spin_write_unlock_irq(void) | |
199 | __releases(torture_spinlock) | |
200 | { | |
201 | spin_unlock_irqrestore(&torture_spinlock, cur_ops->flags); | |
202 | } | |
203 | ||
204 | static struct lock_torture_ops spin_lock_irq_ops = { | |
205 | .writelock = torture_spin_lock_write_lock_irq, | |
206 | .write_delay = torture_spin_lock_write_delay, | |
207 | .writeunlock = torture_lock_spin_write_unlock_irq, | |
208 | .name = "spin_lock_irq" | |
209 | }; | |
210 | ||
42ddc75d DB |
211 | static DEFINE_MUTEX(torture_mutex); |
212 | ||
213 | static int torture_mutex_lock(void) __acquires(torture_mutex) | |
214 | { | |
215 | mutex_lock(&torture_mutex); | |
216 | return 0; | |
217 | } | |
218 | ||
219 | static void torture_mutex_delay(struct torture_random_state *trsp) | |
220 | { | |
221 | const unsigned long longdelay_ms = 100; | |
222 | ||
223 | /* We want a long delay occasionally to force massive contention. */ | |
224 | if (!(torture_random(trsp) % | |
225 | (nrealwriters_stress * 2000 * longdelay_ms))) | |
226 | mdelay(longdelay_ms * 5); | |
227 | else | |
228 | mdelay(longdelay_ms / 5); | |
229 | #ifdef CONFIG_PREEMPT | |
230 | if (!(torture_random(trsp) % (nrealwriters_stress * 20000))) | |
231 | preempt_schedule(); /* Allow test to be preempted. */ | |
232 | #endif | |
233 | } | |
234 | ||
235 | static void torture_mutex_unlock(void) __releases(torture_mutex) | |
236 | { | |
237 | mutex_unlock(&torture_mutex); | |
238 | } | |
239 | ||
240 | static struct lock_torture_ops mutex_lock_ops = { | |
241 | .writelock = torture_mutex_lock, | |
242 | .write_delay = torture_mutex_delay, | |
243 | .writeunlock = torture_mutex_unlock, | |
244 | .name = "mutex_lock" | |
245 | }; | |
246 | ||
0af3fe1e PM |
247 | /* |
248 | * Lock torture writer kthread. Repeatedly acquires and releases | |
249 | * the lock, checking for duplicate acquisitions. | |
250 | */ | |
251 | static int lock_torture_writer(void *arg) | |
252 | { | |
1e6757a9 | 253 | struct lock_stress_stats *lwsp = arg; |
0af3fe1e PM |
254 | static DEFINE_TORTURE_RANDOM(rand); |
255 | ||
256 | VERBOSE_TOROUT_STRING("lock_torture_writer task started"); | |
8698a745 | 257 | set_user_nice(current, MAX_NICE); |
0af3fe1e PM |
258 | |
259 | do { | |
da601c63 PM |
260 | if ((torture_random(&rand) & 0xfffff) == 0) |
261 | schedule_timeout_uninterruptible(1); | |
0af3fe1e PM |
262 | cur_ops->writelock(); |
263 | if (WARN_ON_ONCE(lock_is_write_held)) | |
1e6757a9 | 264 | lwsp->n_lock_fail++; |
0af3fe1e | 265 | lock_is_write_held = 1; |
1e6757a9 | 266 | lwsp->n_lock_acquired++; |
0af3fe1e PM |
267 | cur_ops->write_delay(&rand); |
268 | lock_is_write_held = 0; | |
269 | cur_ops->writeunlock(); | |
270 | stutter_wait("lock_torture_writer"); | |
271 | } while (!torture_must_stop()); | |
272 | torture_kthread_stopping("lock_torture_writer"); | |
273 | return 0; | |
274 | } | |
275 | ||
276 | /* | |
277 | * Create an lock-torture-statistics message in the specified buffer. | |
278 | */ | |
279 | static void lock_torture_printk(char *page) | |
280 | { | |
281 | bool fail = 0; | |
282 | int i; | |
283 | long max = 0; | |
1e6757a9 | 284 | long min = lwsa[0].n_lock_acquired; |
0af3fe1e PM |
285 | long long sum = 0; |
286 | ||
287 | for (i = 0; i < nrealwriters_stress; i++) { | |
1e6757a9 | 288 | if (lwsa[i].n_lock_fail) |
0af3fe1e | 289 | fail = true; |
1e6757a9 DB |
290 | sum += lwsa[i].n_lock_acquired; |
291 | if (max < lwsa[i].n_lock_fail) | |
292 | max = lwsa[i].n_lock_fail; | |
293 | if (min > lwsa[i].n_lock_fail) | |
294 | min = lwsa[i].n_lock_fail; | |
0af3fe1e PM |
295 | } |
296 | page += sprintf(page, "%s%s ", torture_type, TORTURE_FLAG); | |
297 | page += sprintf(page, | |
298 | "Writes: Total: %lld Max/Min: %ld/%ld %s Fail: %d %s\n", | |
299 | sum, max, min, max / 2 > min ? "???" : "", | |
300 | fail, fail ? "!!!" : ""); | |
301 | if (fail) | |
302 | atomic_inc(&n_lock_torture_errors); | |
303 | } | |
304 | ||
305 | /* | |
306 | * Print torture statistics. Caller must ensure that there is only one | |
307 | * call to this function at a given time!!! This is normally accomplished | |
308 | * by relying on the module system to only have one copy of the module | |
309 | * loaded, and then by giving the lock_torture_stats kthread full control | |
310 | * (or the init/cleanup functions when lock_torture_stats thread is not | |
311 | * running). | |
312 | */ | |
313 | static void lock_torture_stats_print(void) | |
314 | { | |
315 | int size = nrealwriters_stress * 200 + 8192; | |
316 | char *buf; | |
317 | ||
318 | buf = kmalloc(size, GFP_KERNEL); | |
319 | if (!buf) { | |
320 | pr_err("lock_torture_stats_print: Out of memory, need: %d", | |
321 | size); | |
322 | return; | |
323 | } | |
324 | lock_torture_printk(buf); | |
325 | pr_alert("%s", buf); | |
326 | kfree(buf); | |
327 | } | |
328 | ||
329 | /* | |
330 | * Periodically prints torture statistics, if periodic statistics printing | |
331 | * was specified via the stat_interval module parameter. | |
332 | * | |
333 | * No need to worry about fullstop here, since this one doesn't reference | |
334 | * volatile state or register callbacks. | |
335 | */ | |
336 | static int lock_torture_stats(void *arg) | |
337 | { | |
338 | VERBOSE_TOROUT_STRING("lock_torture_stats task started"); | |
339 | do { | |
340 | schedule_timeout_interruptible(stat_interval * HZ); | |
341 | lock_torture_stats_print(); | |
342 | torture_shutdown_absorb("lock_torture_stats"); | |
343 | } while (!torture_must_stop()); | |
344 | torture_kthread_stopping("lock_torture_stats"); | |
345 | return 0; | |
346 | } | |
347 | ||
348 | static inline void | |
349 | lock_torture_print_module_parms(struct lock_torture_ops *cur_ops, | |
350 | const char *tag) | |
351 | { | |
352 | pr_alert("%s" TORTURE_FLAG | |
f095bfc0 DB |
353 | "--- %s%s: nwriters_stress=%d stat_interval=%d verbose=%d shuffle_interval=%d stutter=%d shutdown_secs=%d onoff_interval=%d onoff_holdoff=%d\n", |
354 | torture_type, tag, debug_lock ? " [debug]": "", | |
355 | nrealwriters_stress, stat_interval, verbose, | |
0af3fe1e PM |
356 | shuffle_interval, stutter, shutdown_secs, |
357 | onoff_interval, onoff_holdoff); | |
358 | } | |
359 | ||
360 | static void lock_torture_cleanup(void) | |
361 | { | |
362 | int i; | |
363 | ||
d36a7a0d | 364 | if (torture_cleanup_begin()) |
0af3fe1e PM |
365 | return; |
366 | ||
367 | if (writer_tasks) { | |
368 | for (i = 0; i < nrealwriters_stress; i++) | |
369 | torture_stop_kthread(lock_torture_writer, | |
370 | writer_tasks[i]); | |
371 | kfree(writer_tasks); | |
372 | writer_tasks = NULL; | |
373 | } | |
374 | ||
375 | torture_stop_kthread(lock_torture_stats, stats_task); | |
376 | lock_torture_stats_print(); /* -After- the stats thread is stopped! */ | |
377 | ||
378 | if (atomic_read(&n_lock_torture_errors)) | |
379 | lock_torture_print_module_parms(cur_ops, | |
380 | "End of test: FAILURE"); | |
381 | else if (torture_onoff_failures()) | |
382 | lock_torture_print_module_parms(cur_ops, | |
383 | "End of test: LOCK_HOTPLUG"); | |
384 | else | |
385 | lock_torture_print_module_parms(cur_ops, | |
386 | "End of test: SUCCESS"); | |
d36a7a0d | 387 | torture_cleanup_end(); |
0af3fe1e PM |
388 | } |
389 | ||
390 | static int __init lock_torture_init(void) | |
391 | { | |
392 | int i; | |
393 | int firsterr = 0; | |
394 | static struct lock_torture_ops *torture_ops[] = { | |
42ddc75d | 395 | &lock_busted_ops, &spin_lock_ops, &spin_lock_irq_ops, &mutex_lock_ops, |
0af3fe1e PM |
396 | }; |
397 | ||
23a8e5c2 | 398 | if (!torture_init_begin(torture_type, verbose, &torture_runnable)) |
5228084e | 399 | return -EBUSY; |
0af3fe1e PM |
400 | |
401 | /* Process args and tell the world that the torturer is on the job. */ | |
402 | for (i = 0; i < ARRAY_SIZE(torture_ops); i++) { | |
403 | cur_ops = torture_ops[i]; | |
404 | if (strcmp(torture_type, cur_ops->name) == 0) | |
405 | break; | |
406 | } | |
407 | if (i == ARRAY_SIZE(torture_ops)) { | |
408 | pr_alert("lock-torture: invalid torture type: \"%s\"\n", | |
409 | torture_type); | |
410 | pr_alert("lock-torture types:"); | |
411 | for (i = 0; i < ARRAY_SIZE(torture_ops); i++) | |
412 | pr_alert(" %s", torture_ops[i]->name); | |
413 | pr_alert("\n"); | |
414 | torture_init_end(); | |
415 | return -EINVAL; | |
416 | } | |
417 | if (cur_ops->init) | |
418 | cur_ops->init(); /* no "goto unwind" prior to this point!!! */ | |
419 | ||
420 | if (nwriters_stress >= 0) | |
421 | nrealwriters_stress = nwriters_stress; | |
422 | else | |
423 | nrealwriters_stress = 2 * num_online_cpus(); | |
f095bfc0 DB |
424 | |
425 | #ifdef CONFIG_DEBUG_MUTEXES | |
426 | if (strncmp(torture_type, "mutex", 5) == 0) | |
427 | debug_lock = true; | |
428 | #endif | |
429 | #ifdef CONFIG_DEBUG_SPINLOCK | |
430 | if (strncmp(torture_type, "spin", 4) == 0) | |
431 | debug_lock = true; | |
432 | #endif | |
0af3fe1e PM |
433 | lock_torture_print_module_parms(cur_ops, "Start of test"); |
434 | ||
435 | /* Initialize the statistics so that each run gets its own numbers. */ | |
436 | ||
437 | lock_is_write_held = 0; | |
438 | lwsa = kmalloc(sizeof(*lwsa) * nrealwriters_stress, GFP_KERNEL); | |
439 | if (lwsa == NULL) { | |
440 | VERBOSE_TOROUT_STRING("lwsa: Out of memory"); | |
441 | firsterr = -ENOMEM; | |
442 | goto unwind; | |
443 | } | |
444 | for (i = 0; i < nrealwriters_stress; i++) { | |
1e6757a9 DB |
445 | lwsa[i].n_lock_fail = 0; |
446 | lwsa[i].n_lock_acquired = 0; | |
0af3fe1e PM |
447 | } |
448 | ||
449 | /* Start up the kthreads. */ | |
450 | ||
451 | if (onoff_interval > 0) { | |
452 | firsterr = torture_onoff_init(onoff_holdoff * HZ, | |
453 | onoff_interval * HZ); | |
454 | if (firsterr) | |
455 | goto unwind; | |
456 | } | |
457 | if (shuffle_interval > 0) { | |
458 | firsterr = torture_shuffle_init(shuffle_interval); | |
459 | if (firsterr) | |
460 | goto unwind; | |
461 | } | |
462 | if (shutdown_secs > 0) { | |
463 | firsterr = torture_shutdown_init(shutdown_secs, | |
464 | lock_torture_cleanup); | |
465 | if (firsterr) | |
466 | goto unwind; | |
467 | } | |
468 | if (stutter > 0) { | |
469 | firsterr = torture_stutter_init(stutter); | |
470 | if (firsterr) | |
471 | goto unwind; | |
472 | } | |
473 | ||
474 | writer_tasks = kzalloc(nrealwriters_stress * sizeof(writer_tasks[0]), | |
475 | GFP_KERNEL); | |
476 | if (writer_tasks == NULL) { | |
477 | VERBOSE_TOROUT_ERRSTRING("writer_tasks: Out of memory"); | |
478 | firsterr = -ENOMEM; | |
479 | goto unwind; | |
480 | } | |
481 | for (i = 0; i < nrealwriters_stress; i++) { | |
482 | firsterr = torture_create_kthread(lock_torture_writer, &lwsa[i], | |
483 | writer_tasks[i]); | |
484 | if (firsterr) | |
485 | goto unwind; | |
486 | } | |
487 | if (stat_interval > 0) { | |
488 | firsterr = torture_create_kthread(lock_torture_stats, NULL, | |
489 | stats_task); | |
490 | if (firsterr) | |
491 | goto unwind; | |
492 | } | |
493 | torture_init_end(); | |
494 | return 0; | |
495 | ||
496 | unwind: | |
497 | torture_init_end(); | |
498 | lock_torture_cleanup(); | |
499 | return firsterr; | |
500 | } | |
501 | ||
502 | module_init(lock_torture_init); | |
503 | module_exit(lock_torture_cleanup); |