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51b1130e PM |
1 | /* |
2 | * Common functions for in-kernel torture tests. | |
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 | ||
49 | MODULE_LICENSE("GPL"); | |
50 | MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com>"); | |
51 | ||
b5daa8f3 PM |
52 | static char *torture_type; |
53 | static bool verbose; | |
54 | ||
36970bb9 PM |
55 | /* Mediate rmmod and system shutdown. Concurrent rmmod & shutdown illegal! */ |
56 | #define FULLSTOP_DONTSTOP 0 /* Normal operation. */ | |
57 | #define FULLSTOP_SHUTDOWN 1 /* System shutdown with torture running. */ | |
58 | #define FULLSTOP_RMMOD 2 /* Normal rmmod of torture. */ | |
59 | static int fullstop = FULLSTOP_RMMOD; | |
4622b487 | 60 | static DEFINE_MUTEX(fullstop_mutex); |
628edaa5 | 61 | static int *torture_runnable; |
f67a3356 | 62 | |
2e9e8081 PM |
63 | #ifdef CONFIG_HOTPLUG_CPU |
64 | ||
65 | /* | |
66 | * Variables for online-offline handling. Only present if CPU hotplug | |
67 | * is enabled, otherwise does nothing. | |
68 | */ | |
69 | ||
70 | static struct task_struct *onoff_task; | |
71 | static long onoff_holdoff; | |
72 | static long onoff_interval; | |
73 | static long n_offline_attempts; | |
74 | static long n_offline_successes; | |
75 | static unsigned long sum_offline; | |
76 | static int min_offline = -1; | |
77 | static int max_offline; | |
78 | static long n_online_attempts; | |
79 | static long n_online_successes; | |
80 | static unsigned long sum_online; | |
81 | static int min_online = -1; | |
82 | static int max_online; | |
83 | ||
84 | /* | |
85 | * Execute random CPU-hotplug operations at the interval specified | |
86 | * by the onoff_interval. | |
87 | */ | |
88 | static int | |
89 | torture_onoff(void *arg) | |
90 | { | |
91 | int cpu; | |
92 | unsigned long delta; | |
93 | int maxcpu = -1; | |
94 | DEFINE_TORTURE_RANDOM(rand); | |
95 | int ret; | |
96 | unsigned long starttime; | |
97 | ||
98 | VERBOSE_TOROUT_STRING("torture_onoff task started"); | |
99 | for_each_online_cpu(cpu) | |
100 | maxcpu = cpu; | |
101 | WARN_ON(maxcpu < 0); | |
102 | if (onoff_holdoff > 0) { | |
103 | VERBOSE_TOROUT_STRING("torture_onoff begin holdoff"); | |
104 | schedule_timeout_interruptible(onoff_holdoff); | |
105 | VERBOSE_TOROUT_STRING("torture_onoff end holdoff"); | |
106 | } | |
107 | while (!torture_must_stop()) { | |
108 | cpu = (torture_random(&rand) >> 4) % (maxcpu + 1); | |
109 | if (cpu_online(cpu) && cpu_is_hotpluggable(cpu)) { | |
110 | if (verbose) | |
111 | pr_alert("%s" TORTURE_FLAG | |
112 | "torture_onoff task: offlining %d\n", | |
113 | torture_type, cpu); | |
114 | starttime = jiffies; | |
115 | n_offline_attempts++; | |
116 | ret = cpu_down(cpu); | |
117 | if (ret) { | |
118 | if (verbose) | |
119 | pr_alert("%s" TORTURE_FLAG | |
120 | "torture_onoff task: offline %d failed: errno %d\n", | |
121 | torture_type, cpu, ret); | |
122 | } else { | |
123 | if (verbose) | |
124 | pr_alert("%s" TORTURE_FLAG | |
125 | "torture_onoff task: offlined %d\n", | |
126 | torture_type, cpu); | |
127 | n_offline_successes++; | |
128 | delta = jiffies - starttime; | |
129 | sum_offline += delta; | |
130 | if (min_offline < 0) { | |
131 | min_offline = delta; | |
132 | max_offline = delta; | |
133 | } | |
134 | if (min_offline > delta) | |
135 | min_offline = delta; | |
136 | if (max_offline < delta) | |
137 | max_offline = delta; | |
138 | } | |
139 | } else if (cpu_is_hotpluggable(cpu)) { | |
140 | if (verbose) | |
141 | pr_alert("%s" TORTURE_FLAG | |
142 | "torture_onoff task: onlining %d\n", | |
143 | torture_type, cpu); | |
144 | starttime = jiffies; | |
145 | n_online_attempts++; | |
146 | ret = cpu_up(cpu); | |
147 | if (ret) { | |
148 | if (verbose) | |
149 | pr_alert("%s" TORTURE_FLAG | |
150 | "torture_onoff task: online %d failed: errno %d\n", | |
151 | torture_type, cpu, ret); | |
152 | } else { | |
153 | if (verbose) | |
154 | pr_alert("%s" TORTURE_FLAG | |
155 | "torture_onoff task: onlined %d\n", | |
156 | torture_type, cpu); | |
157 | n_online_successes++; | |
158 | delta = jiffies - starttime; | |
159 | sum_online += delta; | |
160 | if (min_online < 0) { | |
161 | min_online = delta; | |
162 | max_online = delta; | |
163 | } | |
164 | if (min_online > delta) | |
165 | min_online = delta; | |
166 | if (max_online < delta) | |
167 | max_online = delta; | |
168 | } | |
169 | } | |
170 | schedule_timeout_interruptible(onoff_interval); | |
171 | } | |
7fafaac5 | 172 | torture_kthread_stopping("torture_onoff"); |
2e9e8081 PM |
173 | return 0; |
174 | } | |
175 | ||
176 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ | |
177 | ||
178 | /* | |
179 | * Initiate online-offline handling. | |
180 | */ | |
181 | int torture_onoff_init(long ooholdoff, long oointerval) | |
182 | { | |
183 | #ifdef CONFIG_HOTPLUG_CPU | |
184 | int ret; | |
185 | ||
186 | onoff_holdoff = ooholdoff; | |
187 | onoff_interval = oointerval; | |
188 | if (onoff_interval <= 0) | |
189 | return 0; | |
14562d1c | 190 | VERBOSE_TOROUT_STRING("Creating torture_onoff task"); |
2e9e8081 PM |
191 | onoff_task = kthread_run(torture_onoff, NULL, "torture_onoff"); |
192 | if (IS_ERR(onoff_task)) { | |
193 | ret = PTR_ERR(onoff_task); | |
194 | onoff_task = NULL; | |
195 | return ret; | |
196 | } | |
197 | torture_shuffle_task_register(onoff_task); | |
198 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ | |
199 | return 0; | |
200 | } | |
201 | EXPORT_SYMBOL_GPL(torture_onoff_init); | |
202 | ||
203 | /* | |
204 | * Clean up after online/offline testing. | |
205 | */ | |
cc47ae08 | 206 | static void torture_onoff_cleanup(void) |
2e9e8081 PM |
207 | { |
208 | #ifdef CONFIG_HOTPLUG_CPU | |
209 | if (onoff_task == NULL) | |
210 | return; | |
211 | VERBOSE_TOROUT_STRING("Stopping torture_onoff task"); | |
212 | kthread_stop(onoff_task); | |
213 | onoff_task = NULL; | |
214 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ | |
215 | } | |
216 | EXPORT_SYMBOL_GPL(torture_onoff_cleanup); | |
217 | ||
218 | /* | |
219 | * Print online/offline testing statistics. | |
220 | */ | |
221 | char *torture_onoff_stats(char *page) | |
222 | { | |
223 | #ifdef CONFIG_HOTPLUG_CPU | |
224 | page += sprintf(page, | |
225 | "onoff: %ld/%ld:%ld/%ld %d,%d:%d,%d %lu:%lu (HZ=%d) ", | |
226 | n_online_successes, n_online_attempts, | |
227 | n_offline_successes, n_offline_attempts, | |
228 | min_online, max_online, | |
229 | min_offline, max_offline, | |
230 | sum_online, sum_offline, HZ); | |
231 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ | |
232 | return page; | |
233 | } | |
234 | EXPORT_SYMBOL_GPL(torture_onoff_stats); | |
235 | ||
236 | /* | |
237 | * Were all the online/offline operations successful? | |
238 | */ | |
239 | bool torture_onoff_failures(void) | |
240 | { | |
241 | #ifdef CONFIG_HOTPLUG_CPU | |
242 | return n_online_successes != n_online_attempts || | |
243 | n_offline_successes != n_offline_attempts; | |
244 | #else /* #ifdef CONFIG_HOTPLUG_CPU */ | |
245 | return false; | |
246 | #endif /* #else #ifdef CONFIG_HOTPLUG_CPU */ | |
247 | } | |
248 | EXPORT_SYMBOL_GPL(torture_onoff_failures); | |
249 | ||
51b1130e PM |
250 | #define TORTURE_RANDOM_MULT 39916801 /* prime */ |
251 | #define TORTURE_RANDOM_ADD 479001701 /* prime */ | |
252 | #define TORTURE_RANDOM_REFRESH 10000 | |
253 | ||
254 | /* | |
255 | * Crude but fast random-number generator. Uses a linear congruential | |
256 | * generator, with occasional help from cpu_clock(). | |
257 | */ | |
258 | unsigned long | |
259 | torture_random(struct torture_random_state *trsp) | |
260 | { | |
261 | if (--trsp->trs_count < 0) { | |
262 | trsp->trs_state += (unsigned long)local_clock(); | |
263 | trsp->trs_count = TORTURE_RANDOM_REFRESH; | |
264 | } | |
265 | trsp->trs_state = trsp->trs_state * TORTURE_RANDOM_MULT + | |
266 | TORTURE_RANDOM_ADD; | |
267 | return swahw32(trsp->trs_state); | |
268 | } | |
269 | EXPORT_SYMBOL_GPL(torture_random); | |
f67a3356 | 270 | |
3808dc9f PM |
271 | /* |
272 | * Variables for shuffling. The idea is to ensure that each CPU stays | |
273 | * idle for an extended period to test interactions with dyntick idle, | |
274 | * as well as interactions with any per-CPU varibles. | |
275 | */ | |
276 | struct shuffle_task { | |
277 | struct list_head st_l; | |
278 | struct task_struct *st_t; | |
279 | }; | |
280 | ||
281 | static long shuffle_interval; /* In jiffies. */ | |
282 | static struct task_struct *shuffler_task; | |
283 | static cpumask_var_t shuffle_tmp_mask; | |
284 | static int shuffle_idle_cpu; /* Force all torture tasks off this CPU */ | |
285 | static struct list_head shuffle_task_list = LIST_HEAD_INIT(shuffle_task_list); | |
286 | static DEFINE_MUTEX(shuffle_task_mutex); | |
287 | ||
288 | /* | |
289 | * Register a task to be shuffled. If there is no memory, just splat | |
290 | * and don't bother registering. | |
291 | */ | |
292 | void torture_shuffle_task_register(struct task_struct *tp) | |
293 | { | |
294 | struct shuffle_task *stp; | |
295 | ||
296 | if (WARN_ON_ONCE(tp == NULL)) | |
297 | return; | |
298 | stp = kmalloc(sizeof(*stp), GFP_KERNEL); | |
299 | if (WARN_ON_ONCE(stp == NULL)) | |
300 | return; | |
301 | stp->st_t = tp; | |
302 | mutex_lock(&shuffle_task_mutex); | |
303 | list_add(&stp->st_l, &shuffle_task_list); | |
304 | mutex_unlock(&shuffle_task_mutex); | |
305 | } | |
306 | EXPORT_SYMBOL_GPL(torture_shuffle_task_register); | |
307 | ||
308 | /* | |
309 | * Unregister all tasks, for example, at the end of the torture run. | |
310 | */ | |
311 | static void torture_shuffle_task_unregister_all(void) | |
312 | { | |
313 | struct shuffle_task *stp; | |
314 | struct shuffle_task *p; | |
315 | ||
316 | mutex_lock(&shuffle_task_mutex); | |
317 | list_for_each_entry_safe(stp, p, &shuffle_task_list, st_l) { | |
318 | list_del(&stp->st_l); | |
319 | kfree(stp); | |
320 | } | |
321 | mutex_unlock(&shuffle_task_mutex); | |
322 | } | |
323 | ||
324 | /* Shuffle tasks such that we allow shuffle_idle_cpu to become idle. | |
325 | * A special case is when shuffle_idle_cpu = -1, in which case we allow | |
326 | * the tasks to run on all CPUs. | |
327 | */ | |
328 | static void torture_shuffle_tasks(void) | |
329 | { | |
330 | struct shuffle_task *stp; | |
331 | ||
332 | cpumask_setall(shuffle_tmp_mask); | |
333 | get_online_cpus(); | |
334 | ||
335 | /* No point in shuffling if there is only one online CPU (ex: UP) */ | |
336 | if (num_online_cpus() == 1) { | |
337 | put_online_cpus(); | |
338 | return; | |
339 | } | |
340 | ||
341 | /* Advance to the next CPU. Upon overflow, don't idle any CPUs. */ | |
342 | shuffle_idle_cpu = cpumask_next(shuffle_idle_cpu, shuffle_tmp_mask); | |
343 | if (shuffle_idle_cpu >= nr_cpu_ids) | |
344 | shuffle_idle_cpu = -1; | |
345 | if (shuffle_idle_cpu != -1) { | |
346 | cpumask_clear_cpu(shuffle_idle_cpu, shuffle_tmp_mask); | |
347 | if (cpumask_empty(shuffle_tmp_mask)) { | |
348 | put_online_cpus(); | |
349 | return; | |
350 | } | |
351 | } | |
352 | ||
353 | mutex_lock(&shuffle_task_mutex); | |
354 | list_for_each_entry(stp, &shuffle_task_list, st_l) | |
355 | set_cpus_allowed_ptr(stp->st_t, shuffle_tmp_mask); | |
356 | mutex_unlock(&shuffle_task_mutex); | |
357 | ||
358 | put_online_cpus(); | |
359 | } | |
360 | ||
361 | /* Shuffle tasks across CPUs, with the intent of allowing each CPU in the | |
362 | * system to become idle at a time and cut off its timer ticks. This is meant | |
363 | * to test the support for such tickless idle CPU in RCU. | |
364 | */ | |
365 | static int torture_shuffle(void *arg) | |
366 | { | |
367 | VERBOSE_TOROUT_STRING("torture_shuffle task started"); | |
368 | do { | |
369 | schedule_timeout_interruptible(shuffle_interval); | |
370 | torture_shuffle_tasks(); | |
371 | torture_shutdown_absorb("torture_shuffle"); | |
372 | } while (!torture_must_stop()); | |
7fafaac5 | 373 | torture_kthread_stopping("torture_shuffle"); |
3808dc9f PM |
374 | return 0; |
375 | } | |
376 | ||
377 | /* | |
378 | * Start the shuffler, with shuffint in jiffies. | |
379 | */ | |
380 | int torture_shuffle_init(long shuffint) | |
381 | { | |
382 | int ret; | |
383 | ||
384 | shuffle_interval = shuffint; | |
385 | ||
386 | shuffle_idle_cpu = -1; | |
387 | ||
388 | if (!alloc_cpumask_var(&shuffle_tmp_mask, GFP_KERNEL)) { | |
389 | VERBOSE_TOROUT_ERRSTRING("Failed to alloc mask"); | |
390 | return -ENOMEM; | |
391 | } | |
392 | ||
393 | /* Create the shuffler thread */ | |
14562d1c | 394 | VERBOSE_TOROUT_STRING("Creating torture_shuffle task"); |
3808dc9f PM |
395 | shuffler_task = kthread_run(torture_shuffle, NULL, "torture_shuffle"); |
396 | if (IS_ERR(shuffler_task)) { | |
397 | ret = PTR_ERR(shuffler_task); | |
398 | free_cpumask_var(shuffle_tmp_mask); | |
399 | VERBOSE_TOROUT_ERRSTRING("Failed to create shuffler"); | |
400 | shuffler_task = NULL; | |
401 | return ret; | |
402 | } | |
403 | torture_shuffle_task_register(shuffler_task); | |
404 | return 0; | |
405 | } | |
406 | EXPORT_SYMBOL_GPL(torture_shuffle_init); | |
407 | ||
408 | /* | |
409 | * Stop the shuffling. | |
410 | */ | |
cc47ae08 | 411 | static void torture_shuffle_cleanup(void) |
3808dc9f PM |
412 | { |
413 | torture_shuffle_task_unregister_all(); | |
414 | if (shuffler_task) { | |
415 | VERBOSE_TOROUT_STRING("Stopping torture_shuffle task"); | |
416 | kthread_stop(shuffler_task); | |
417 | free_cpumask_var(shuffle_tmp_mask); | |
418 | } | |
419 | shuffler_task = NULL; | |
420 | } | |
421 | EXPORT_SYMBOL_GPL(torture_shuffle_cleanup); | |
422 | ||
e991dbc0 PM |
423 | /* |
424 | * Variables for auto-shutdown. This allows "lights out" torture runs | |
425 | * to be fully scripted. | |
426 | */ | |
427 | static int shutdown_secs; /* desired test duration in seconds. */ | |
428 | static struct task_struct *shutdown_task; | |
429 | static unsigned long shutdown_time; /* jiffies to system shutdown. */ | |
430 | static void (*torture_shutdown_hook)(void); | |
431 | ||
f67a3356 PM |
432 | /* |
433 | * Absorb kthreads into a kernel function that won't return, so that | |
434 | * they won't ever access module text or data again. | |
435 | */ | |
436 | void torture_shutdown_absorb(const char *title) | |
437 | { | |
438 | while (ACCESS_ONCE(fullstop) == FULLSTOP_SHUTDOWN) { | |
4622b487 PM |
439 | pr_notice("torture thread %s parking due to system shutdown\n", |
440 | title); | |
f67a3356 PM |
441 | schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT); |
442 | } | |
443 | } | |
444 | EXPORT_SYMBOL_GPL(torture_shutdown_absorb); | |
b5daa8f3 | 445 | |
e991dbc0 PM |
446 | /* |
447 | * Cause the torture test to shutdown the system after the test has | |
448 | * run for the time specified by the shutdown_secs parameter. | |
449 | */ | |
450 | static int torture_shutdown(void *arg) | |
451 | { | |
452 | long delta; | |
453 | unsigned long jiffies_snap; | |
454 | ||
455 | VERBOSE_TOROUT_STRING("torture_shutdown task started"); | |
456 | jiffies_snap = jiffies; | |
457 | while (ULONG_CMP_LT(jiffies_snap, shutdown_time) && | |
458 | !torture_must_stop()) { | |
459 | delta = shutdown_time - jiffies_snap; | |
460 | if (verbose) | |
461 | pr_alert("%s" TORTURE_FLAG | |
462 | "torture_shutdown task: %lu jiffies remaining\n", | |
463 | torture_type, delta); | |
464 | schedule_timeout_interruptible(delta); | |
465 | jiffies_snap = jiffies; | |
466 | } | |
467 | if (torture_must_stop()) { | |
7fafaac5 | 468 | torture_kthread_stopping("torture_shutdown"); |
e991dbc0 PM |
469 | return 0; |
470 | } | |
471 | ||
472 | /* OK, shut down the system. */ | |
473 | ||
474 | VERBOSE_TOROUT_STRING("torture_shutdown task shutting down system"); | |
475 | shutdown_task = NULL; /* Avoid self-kill deadlock. */ | |
476 | torture_shutdown_hook();/* Shut down the enclosing torture test. */ | |
477 | kernel_power_off(); /* Shut down the system. */ | |
478 | return 0; | |
479 | } | |
480 | ||
481 | /* | |
482 | * Start up the shutdown task. | |
483 | */ | |
484 | int torture_shutdown_init(int ssecs, void (*cleanup)(void)) | |
485 | { | |
486 | int ret; | |
487 | ||
488 | shutdown_secs = ssecs; | |
489 | torture_shutdown_hook = cleanup; | |
490 | if (shutdown_secs > 0) { | |
14562d1c | 491 | VERBOSE_TOROUT_STRING("Creating torture_shutdown task"); |
e991dbc0 PM |
492 | shutdown_time = jiffies + shutdown_secs * HZ; |
493 | shutdown_task = kthread_create(torture_shutdown, NULL, | |
494 | "torture_shutdown"); | |
495 | if (IS_ERR(shutdown_task)) { | |
496 | ret = PTR_ERR(shutdown_task); | |
497 | VERBOSE_TOROUT_ERRSTRING("Failed to create shutdown"); | |
498 | shutdown_task = NULL; | |
499 | return ret; | |
500 | } | |
501 | torture_shuffle_task_register(shutdown_task); | |
502 | wake_up_process(shutdown_task); | |
503 | } | |
504 | return 0; | |
505 | } | |
506 | EXPORT_SYMBOL_GPL(torture_shutdown_init); | |
507 | ||
508 | /* | |
509 | * Shut down the shutdown task. Say what??? Heh! This can happen if | |
510 | * the torture module gets an rmmod before the shutdown time arrives. ;-) | |
511 | */ | |
512 | void torture_shutdown_cleanup(void) | |
513 | { | |
514 | if (shutdown_task != NULL) { | |
515 | VERBOSE_TOROUT_STRING("Stopping torture_shutdown task"); | |
516 | kthread_stop(shutdown_task); | |
517 | } | |
518 | shutdown_task = NULL; | |
519 | } | |
520 | EXPORT_SYMBOL_GPL(torture_shutdown_cleanup); | |
521 | ||
4622b487 PM |
522 | /* |
523 | * Detect and respond to a system shutdown. | |
524 | */ | |
525 | static int torture_shutdown_notify(struct notifier_block *unused1, | |
526 | unsigned long unused2, void *unused3) | |
527 | { | |
528 | mutex_lock(&fullstop_mutex); | |
57a2fe90 | 529 | if (ACCESS_ONCE(fullstop) == FULLSTOP_DONTSTOP) { |
fac480ef | 530 | VERBOSE_TOROUT_STRING("Unscheduled system shutdown detected"); |
57a2fe90 | 531 | ACCESS_ONCE(fullstop) = FULLSTOP_SHUTDOWN; |
fac480ef | 532 | } else { |
4622b487 | 533 | pr_warn("Concurrent rmmod and shutdown illegal!\n"); |
fac480ef | 534 | } |
4622b487 PM |
535 | mutex_unlock(&fullstop_mutex); |
536 | return NOTIFY_DONE; | |
537 | } | |
538 | ||
539 | static struct notifier_block torture_shutdown_nb = { | |
540 | .notifier_call = torture_shutdown_notify, | |
541 | }; | |
542 | ||
628edaa5 PM |
543 | /* |
544 | * Variables for stuttering, which means to periodically pause and | |
545 | * restart testing in order to catch bugs that appear when load is | |
546 | * suddenly applied to or removed from the system. | |
547 | */ | |
548 | static struct task_struct *stutter_task; | |
549 | static int stutter_pause_test; | |
550 | static int stutter; | |
551 | ||
552 | /* | |
553 | * Block until the stutter interval ends. This must be called periodically | |
554 | * by all running kthreads that need to be subject to stuttering. | |
555 | */ | |
556 | void stutter_wait(const char *title) | |
557 | { | |
558 | while (ACCESS_ONCE(stutter_pause_test) || | |
559 | (torture_runnable && !ACCESS_ONCE(*torture_runnable))) { | |
560 | if (stutter_pause_test) | |
561 | schedule_timeout_interruptible(1); | |
562 | else | |
563 | schedule_timeout_interruptible(round_jiffies_relative(HZ)); | |
564 | torture_shutdown_absorb(title); | |
565 | } | |
566 | } | |
567 | EXPORT_SYMBOL_GPL(stutter_wait); | |
568 | ||
569 | /* | |
570 | * Cause the torture test to "stutter", starting and stopping all | |
571 | * threads periodically. | |
572 | */ | |
573 | static int torture_stutter(void *arg) | |
574 | { | |
575 | VERBOSE_TOROUT_STRING("torture_stutter task started"); | |
576 | do { | |
577 | if (!torture_must_stop()) { | |
578 | schedule_timeout_interruptible(stutter); | |
579 | ACCESS_ONCE(stutter_pause_test) = 1; | |
580 | } | |
581 | if (!torture_must_stop()) | |
582 | schedule_timeout_interruptible(stutter); | |
583 | ACCESS_ONCE(stutter_pause_test) = 0; | |
584 | torture_shutdown_absorb("torture_stutter"); | |
585 | } while (!torture_must_stop()); | |
7fafaac5 | 586 | torture_kthread_stopping("torture_stutter"); |
628edaa5 PM |
587 | return 0; |
588 | } | |
589 | ||
590 | /* | |
591 | * Initialize and kick off the torture_stutter kthread. | |
592 | */ | |
593 | int torture_stutter_init(int s) | |
594 | { | |
595 | int ret; | |
596 | ||
597 | stutter = s; | |
14562d1c | 598 | VERBOSE_TOROUT_STRING("Creating torture_stutter task"); |
628edaa5 PM |
599 | stutter_task = kthread_run(torture_stutter, NULL, "torture_stutter"); |
600 | if (IS_ERR(stutter_task)) { | |
601 | ret = PTR_ERR(stutter_task); | |
602 | VERBOSE_TOROUT_ERRSTRING("Failed to create stutter"); | |
603 | stutter_task = NULL; | |
604 | return ret; | |
605 | } | |
606 | torture_shuffle_task_register(stutter_task); | |
607 | return 0; | |
608 | } | |
609 | EXPORT_SYMBOL_GPL(torture_stutter_init); | |
610 | ||
611 | /* | |
612 | * Cleanup after the torture_stutter kthread. | |
613 | */ | |
614 | void torture_stutter_cleanup(void) | |
615 | { | |
616 | if (!stutter_task) | |
617 | return; | |
618 | VERBOSE_TOROUT_STRING("Stopping torture_stutter task"); | |
619 | kthread_stop(stutter_task); | |
620 | stutter_task = NULL; | |
621 | } | |
622 | EXPORT_SYMBOL_GPL(torture_stutter_cleanup); | |
623 | ||
b5daa8f3 PM |
624 | /* |
625 | * Initialize torture module. Please note that this is -not- invoked via | |
626 | * the usual module_init() mechanism, but rather by an explicit call from | |
627 | * the client torture module. This call must be paired with a later | |
628 | * torture_init_end(). | |
628edaa5 PM |
629 | * |
630 | * The runnable parameter points to a flag that controls whether or not | |
631 | * the test is currently runnable. If there is no such flag, pass in NULL. | |
b5daa8f3 | 632 | */ |
628edaa5 | 633 | void __init torture_init_begin(char *ttype, bool v, int *runnable) |
b5daa8f3 PM |
634 | { |
635 | mutex_lock(&fullstop_mutex); | |
636 | torture_type = ttype; | |
637 | verbose = v; | |
628edaa5 | 638 | torture_runnable = runnable; |
36970bb9 | 639 | fullstop = FULLSTOP_DONTSTOP; |
b5daa8f3 PM |
640 | |
641 | } | |
642 | EXPORT_SYMBOL_GPL(torture_init_begin); | |
643 | ||
644 | /* | |
645 | * Tell the torture module that initialization is complete. | |
646 | */ | |
647 | void __init torture_init_end(void) | |
648 | { | |
649 | mutex_unlock(&fullstop_mutex); | |
4622b487 | 650 | register_reboot_notifier(&torture_shutdown_nb); |
b5daa8f3 PM |
651 | } |
652 | EXPORT_SYMBOL_GPL(torture_init_end); | |
cc47ae08 PM |
653 | |
654 | /* | |
655 | * Clean up torture module. Please note that this is -not- invoked via | |
656 | * the usual module_exit() mechanism, but rather by an explicit call from | |
657 | * the client torture module. Returns true if a race with system shutdown | |
658 | * is detected. | |
659 | * | |
660 | * This must be called before the caller starts shutting down its own | |
661 | * kthreads. | |
662 | */ | |
663 | bool torture_cleanup(void) | |
664 | { | |
665 | mutex_lock(&fullstop_mutex); | |
57a2fe90 | 666 | if (ACCESS_ONCE(fullstop) == FULLSTOP_SHUTDOWN) { |
cc47ae08 PM |
667 | pr_warn("Concurrent rmmod and shutdown illegal!\n"); |
668 | mutex_unlock(&fullstop_mutex); | |
669 | schedule_timeout_uninterruptible(10); | |
670 | return true; | |
671 | } | |
57a2fe90 | 672 | ACCESS_ONCE(fullstop) = FULLSTOP_RMMOD; |
cc47ae08 | 673 | mutex_unlock(&fullstop_mutex); |
4622b487 | 674 | unregister_reboot_notifier(&torture_shutdown_nb); |
cc47ae08 PM |
675 | torture_shuffle_cleanup(); |
676 | torture_onoff_cleanup(); | |
677 | return false; | |
678 | } | |
679 | EXPORT_SYMBOL_GPL(torture_cleanup); | |
36970bb9 PM |
680 | |
681 | /* | |
682 | * Is it time for the current torture test to stop? | |
683 | */ | |
684 | bool torture_must_stop(void) | |
685 | { | |
686 | return torture_must_stop_irq() || kthread_should_stop(); | |
687 | } | |
688 | EXPORT_SYMBOL_GPL(torture_must_stop); | |
689 | ||
690 | /* | |
691 | * Is it time for the current torture test to stop? This is the irq-safe | |
692 | * version, hence no check for kthread_should_stop(). | |
693 | */ | |
694 | bool torture_must_stop_irq(void) | |
695 | { | |
57a2fe90 | 696 | return ACCESS_ONCE(fullstop) != FULLSTOP_DONTSTOP; |
36970bb9 PM |
697 | } |
698 | EXPORT_SYMBOL_GPL(torture_must_stop_irq); | |
7fafaac5 PM |
699 | |
700 | /* | |
701 | * Each kthread must wait for kthread_should_stop() before returning from | |
702 | * its top-level function, otherwise segfaults ensue. This function | |
703 | * prints a "stopping" message and waits for kthread_should_stop(), and | |
704 | * should be called from all torture kthreads immediately prior to | |
705 | * returning. | |
706 | */ | |
707 | void torture_kthread_stopping(char *title) | |
708 | { | |
709 | if (verbose) | |
710 | VERBOSE_TOROUT_STRING(title); | |
711 | while (!kthread_should_stop()) { | |
712 | torture_shutdown_absorb(title); | |
713 | schedule_timeout_uninterruptible(1); | |
714 | } | |
715 | } | |
716 | EXPORT_SYMBOL_GPL(torture_kthread_stopping); |