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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 | { | |
47cf29b9 | 183 | int ret = 0; |
2e9e8081 | 184 | |
47cf29b9 | 185 | #ifdef CONFIG_HOTPLUG_CPU |
2e9e8081 PM |
186 | onoff_holdoff = ooholdoff; |
187 | onoff_interval = oointerval; | |
188 | if (onoff_interval <= 0) | |
189 | return 0; | |
47cf29b9 | 190 | ret = torture_create_kthread(torture_onoff, NULL, onoff_task); |
2e9e8081 | 191 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ |
47cf29b9 | 192 | return ret; |
2e9e8081 PM |
193 | } |
194 | EXPORT_SYMBOL_GPL(torture_onoff_init); | |
195 | ||
196 | /* | |
197 | * Clean up after online/offline testing. | |
198 | */ | |
cc47ae08 | 199 | static void torture_onoff_cleanup(void) |
2e9e8081 PM |
200 | { |
201 | #ifdef CONFIG_HOTPLUG_CPU | |
202 | if (onoff_task == NULL) | |
203 | return; | |
204 | VERBOSE_TOROUT_STRING("Stopping torture_onoff task"); | |
205 | kthread_stop(onoff_task); | |
206 | onoff_task = NULL; | |
207 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ | |
208 | } | |
209 | EXPORT_SYMBOL_GPL(torture_onoff_cleanup); | |
210 | ||
211 | /* | |
212 | * Print online/offline testing statistics. | |
213 | */ | |
214 | char *torture_onoff_stats(char *page) | |
215 | { | |
216 | #ifdef CONFIG_HOTPLUG_CPU | |
217 | page += sprintf(page, | |
218 | "onoff: %ld/%ld:%ld/%ld %d,%d:%d,%d %lu:%lu (HZ=%d) ", | |
219 | n_online_successes, n_online_attempts, | |
220 | n_offline_successes, n_offline_attempts, | |
221 | min_online, max_online, | |
222 | min_offline, max_offline, | |
223 | sum_online, sum_offline, HZ); | |
224 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ | |
225 | return page; | |
226 | } | |
227 | EXPORT_SYMBOL_GPL(torture_onoff_stats); | |
228 | ||
229 | /* | |
230 | * Were all the online/offline operations successful? | |
231 | */ | |
232 | bool torture_onoff_failures(void) | |
233 | { | |
234 | #ifdef CONFIG_HOTPLUG_CPU | |
235 | return n_online_successes != n_online_attempts || | |
236 | n_offline_successes != n_offline_attempts; | |
237 | #else /* #ifdef CONFIG_HOTPLUG_CPU */ | |
238 | return false; | |
239 | #endif /* #else #ifdef CONFIG_HOTPLUG_CPU */ | |
240 | } | |
241 | EXPORT_SYMBOL_GPL(torture_onoff_failures); | |
242 | ||
51b1130e PM |
243 | #define TORTURE_RANDOM_MULT 39916801 /* prime */ |
244 | #define TORTURE_RANDOM_ADD 479001701 /* prime */ | |
245 | #define TORTURE_RANDOM_REFRESH 10000 | |
246 | ||
247 | /* | |
248 | * Crude but fast random-number generator. Uses a linear congruential | |
249 | * generator, with occasional help from cpu_clock(). | |
250 | */ | |
251 | unsigned long | |
252 | torture_random(struct torture_random_state *trsp) | |
253 | { | |
254 | if (--trsp->trs_count < 0) { | |
255 | trsp->trs_state += (unsigned long)local_clock(); | |
256 | trsp->trs_count = TORTURE_RANDOM_REFRESH; | |
257 | } | |
258 | trsp->trs_state = trsp->trs_state * TORTURE_RANDOM_MULT + | |
259 | TORTURE_RANDOM_ADD; | |
260 | return swahw32(trsp->trs_state); | |
261 | } | |
262 | EXPORT_SYMBOL_GPL(torture_random); | |
f67a3356 | 263 | |
3808dc9f PM |
264 | /* |
265 | * Variables for shuffling. The idea is to ensure that each CPU stays | |
266 | * idle for an extended period to test interactions with dyntick idle, | |
267 | * as well as interactions with any per-CPU varibles. | |
268 | */ | |
269 | struct shuffle_task { | |
270 | struct list_head st_l; | |
271 | struct task_struct *st_t; | |
272 | }; | |
273 | ||
274 | static long shuffle_interval; /* In jiffies. */ | |
275 | static struct task_struct *shuffler_task; | |
276 | static cpumask_var_t shuffle_tmp_mask; | |
277 | static int shuffle_idle_cpu; /* Force all torture tasks off this CPU */ | |
278 | static struct list_head shuffle_task_list = LIST_HEAD_INIT(shuffle_task_list); | |
279 | static DEFINE_MUTEX(shuffle_task_mutex); | |
280 | ||
281 | /* | |
282 | * Register a task to be shuffled. If there is no memory, just splat | |
283 | * and don't bother registering. | |
284 | */ | |
285 | void torture_shuffle_task_register(struct task_struct *tp) | |
286 | { | |
287 | struct shuffle_task *stp; | |
288 | ||
289 | if (WARN_ON_ONCE(tp == NULL)) | |
290 | return; | |
291 | stp = kmalloc(sizeof(*stp), GFP_KERNEL); | |
292 | if (WARN_ON_ONCE(stp == NULL)) | |
293 | return; | |
294 | stp->st_t = tp; | |
295 | mutex_lock(&shuffle_task_mutex); | |
296 | list_add(&stp->st_l, &shuffle_task_list); | |
297 | mutex_unlock(&shuffle_task_mutex); | |
298 | } | |
299 | EXPORT_SYMBOL_GPL(torture_shuffle_task_register); | |
300 | ||
301 | /* | |
302 | * Unregister all tasks, for example, at the end of the torture run. | |
303 | */ | |
304 | static void torture_shuffle_task_unregister_all(void) | |
305 | { | |
306 | struct shuffle_task *stp; | |
307 | struct shuffle_task *p; | |
308 | ||
309 | mutex_lock(&shuffle_task_mutex); | |
310 | list_for_each_entry_safe(stp, p, &shuffle_task_list, st_l) { | |
311 | list_del(&stp->st_l); | |
312 | kfree(stp); | |
313 | } | |
314 | mutex_unlock(&shuffle_task_mutex); | |
315 | } | |
316 | ||
317 | /* Shuffle tasks such that we allow shuffle_idle_cpu to become idle. | |
318 | * A special case is when shuffle_idle_cpu = -1, in which case we allow | |
319 | * the tasks to run on all CPUs. | |
320 | */ | |
321 | static void torture_shuffle_tasks(void) | |
322 | { | |
323 | struct shuffle_task *stp; | |
324 | ||
325 | cpumask_setall(shuffle_tmp_mask); | |
326 | get_online_cpus(); | |
327 | ||
328 | /* No point in shuffling if there is only one online CPU (ex: UP) */ | |
329 | if (num_online_cpus() == 1) { | |
330 | put_online_cpus(); | |
331 | return; | |
332 | } | |
333 | ||
334 | /* Advance to the next CPU. Upon overflow, don't idle any CPUs. */ | |
335 | shuffle_idle_cpu = cpumask_next(shuffle_idle_cpu, shuffle_tmp_mask); | |
336 | if (shuffle_idle_cpu >= nr_cpu_ids) | |
337 | shuffle_idle_cpu = -1; | |
338 | if (shuffle_idle_cpu != -1) { | |
339 | cpumask_clear_cpu(shuffle_idle_cpu, shuffle_tmp_mask); | |
340 | if (cpumask_empty(shuffle_tmp_mask)) { | |
341 | put_online_cpus(); | |
342 | return; | |
343 | } | |
344 | } | |
345 | ||
346 | mutex_lock(&shuffle_task_mutex); | |
347 | list_for_each_entry(stp, &shuffle_task_list, st_l) | |
348 | set_cpus_allowed_ptr(stp->st_t, shuffle_tmp_mask); | |
349 | mutex_unlock(&shuffle_task_mutex); | |
350 | ||
351 | put_online_cpus(); | |
352 | } | |
353 | ||
354 | /* Shuffle tasks across CPUs, with the intent of allowing each CPU in the | |
355 | * system to become idle at a time and cut off its timer ticks. This is meant | |
356 | * to test the support for such tickless idle CPU in RCU. | |
357 | */ | |
358 | static int torture_shuffle(void *arg) | |
359 | { | |
360 | VERBOSE_TOROUT_STRING("torture_shuffle task started"); | |
361 | do { | |
362 | schedule_timeout_interruptible(shuffle_interval); | |
363 | torture_shuffle_tasks(); | |
364 | torture_shutdown_absorb("torture_shuffle"); | |
365 | } while (!torture_must_stop()); | |
7fafaac5 | 366 | torture_kthread_stopping("torture_shuffle"); |
3808dc9f PM |
367 | return 0; |
368 | } | |
369 | ||
370 | /* | |
371 | * Start the shuffler, with shuffint in jiffies. | |
372 | */ | |
373 | int torture_shuffle_init(long shuffint) | |
374 | { | |
3808dc9f PM |
375 | shuffle_interval = shuffint; |
376 | ||
377 | shuffle_idle_cpu = -1; | |
378 | ||
379 | if (!alloc_cpumask_var(&shuffle_tmp_mask, GFP_KERNEL)) { | |
380 | VERBOSE_TOROUT_ERRSTRING("Failed to alloc mask"); | |
381 | return -ENOMEM; | |
382 | } | |
383 | ||
384 | /* Create the shuffler thread */ | |
47cf29b9 | 385 | return torture_create_kthread(torture_shuffle, NULL, shuffler_task); |
3808dc9f PM |
386 | } |
387 | EXPORT_SYMBOL_GPL(torture_shuffle_init); | |
388 | ||
389 | /* | |
390 | * Stop the shuffling. | |
391 | */ | |
cc47ae08 | 392 | static void torture_shuffle_cleanup(void) |
3808dc9f PM |
393 | { |
394 | torture_shuffle_task_unregister_all(); | |
395 | if (shuffler_task) { | |
396 | VERBOSE_TOROUT_STRING("Stopping torture_shuffle task"); | |
397 | kthread_stop(shuffler_task); | |
398 | free_cpumask_var(shuffle_tmp_mask); | |
399 | } | |
400 | shuffler_task = NULL; | |
401 | } | |
402 | EXPORT_SYMBOL_GPL(torture_shuffle_cleanup); | |
403 | ||
e991dbc0 PM |
404 | /* |
405 | * Variables for auto-shutdown. This allows "lights out" torture runs | |
406 | * to be fully scripted. | |
407 | */ | |
408 | static int shutdown_secs; /* desired test duration in seconds. */ | |
409 | static struct task_struct *shutdown_task; | |
410 | static unsigned long shutdown_time; /* jiffies to system shutdown. */ | |
411 | static void (*torture_shutdown_hook)(void); | |
412 | ||
f67a3356 PM |
413 | /* |
414 | * Absorb kthreads into a kernel function that won't return, so that | |
415 | * they won't ever access module text or data again. | |
416 | */ | |
417 | void torture_shutdown_absorb(const char *title) | |
418 | { | |
419 | while (ACCESS_ONCE(fullstop) == FULLSTOP_SHUTDOWN) { | |
4622b487 PM |
420 | pr_notice("torture thread %s parking due to system shutdown\n", |
421 | title); | |
f67a3356 PM |
422 | schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT); |
423 | } | |
424 | } | |
425 | EXPORT_SYMBOL_GPL(torture_shutdown_absorb); | |
b5daa8f3 | 426 | |
e991dbc0 PM |
427 | /* |
428 | * Cause the torture test to shutdown the system after the test has | |
429 | * run for the time specified by the shutdown_secs parameter. | |
430 | */ | |
431 | static int torture_shutdown(void *arg) | |
432 | { | |
433 | long delta; | |
434 | unsigned long jiffies_snap; | |
435 | ||
436 | VERBOSE_TOROUT_STRING("torture_shutdown task started"); | |
437 | jiffies_snap = jiffies; | |
438 | while (ULONG_CMP_LT(jiffies_snap, shutdown_time) && | |
439 | !torture_must_stop()) { | |
440 | delta = shutdown_time - jiffies_snap; | |
441 | if (verbose) | |
442 | pr_alert("%s" TORTURE_FLAG | |
443 | "torture_shutdown task: %lu jiffies remaining\n", | |
444 | torture_type, delta); | |
445 | schedule_timeout_interruptible(delta); | |
446 | jiffies_snap = jiffies; | |
447 | } | |
448 | if (torture_must_stop()) { | |
7fafaac5 | 449 | torture_kthread_stopping("torture_shutdown"); |
e991dbc0 PM |
450 | return 0; |
451 | } | |
452 | ||
453 | /* OK, shut down the system. */ | |
454 | ||
455 | VERBOSE_TOROUT_STRING("torture_shutdown task shutting down system"); | |
456 | shutdown_task = NULL; /* Avoid self-kill deadlock. */ | |
f881825a PM |
457 | if (torture_shutdown_hook) |
458 | torture_shutdown_hook(); | |
459 | else | |
460 | VERBOSE_TOROUT_STRING("No torture_shutdown_hook(), skipping."); | |
e991dbc0 PM |
461 | kernel_power_off(); /* Shut down the system. */ |
462 | return 0; | |
463 | } | |
464 | ||
465 | /* | |
466 | * Start up the shutdown task. | |
467 | */ | |
468 | int torture_shutdown_init(int ssecs, void (*cleanup)(void)) | |
469 | { | |
47cf29b9 | 470 | int ret = 0; |
e991dbc0 PM |
471 | |
472 | shutdown_secs = ssecs; | |
473 | torture_shutdown_hook = cleanup; | |
474 | if (shutdown_secs > 0) { | |
475 | shutdown_time = jiffies + shutdown_secs * HZ; | |
47cf29b9 PM |
476 | ret = torture_create_kthread(torture_shutdown, NULL, |
477 | shutdown_task); | |
e991dbc0 | 478 | } |
47cf29b9 | 479 | return ret; |
e991dbc0 PM |
480 | } |
481 | EXPORT_SYMBOL_GPL(torture_shutdown_init); | |
482 | ||
4622b487 PM |
483 | /* |
484 | * Detect and respond to a system shutdown. | |
485 | */ | |
486 | static int torture_shutdown_notify(struct notifier_block *unused1, | |
487 | unsigned long unused2, void *unused3) | |
488 | { | |
489 | mutex_lock(&fullstop_mutex); | |
57a2fe90 | 490 | if (ACCESS_ONCE(fullstop) == FULLSTOP_DONTSTOP) { |
fac480ef | 491 | VERBOSE_TOROUT_STRING("Unscheduled system shutdown detected"); |
57a2fe90 | 492 | ACCESS_ONCE(fullstop) = FULLSTOP_SHUTDOWN; |
fac480ef | 493 | } else { |
4622b487 | 494 | pr_warn("Concurrent rmmod and shutdown illegal!\n"); |
fac480ef | 495 | } |
4622b487 PM |
496 | mutex_unlock(&fullstop_mutex); |
497 | return NOTIFY_DONE; | |
498 | } | |
499 | ||
500 | static struct notifier_block torture_shutdown_nb = { | |
501 | .notifier_call = torture_shutdown_notify, | |
502 | }; | |
503 | ||
bfefc73a PM |
504 | /* |
505 | * Shut down the shutdown task. Say what??? Heh! This can happen if | |
506 | * the torture module gets an rmmod before the shutdown time arrives. ;-) | |
507 | */ | |
508 | static void torture_shutdown_cleanup(void) | |
509 | { | |
510 | unregister_reboot_notifier(&torture_shutdown_nb); | |
511 | if (shutdown_task != NULL) { | |
512 | VERBOSE_TOROUT_STRING("Stopping torture_shutdown task"); | |
513 | kthread_stop(shutdown_task); | |
514 | } | |
515 | shutdown_task = NULL; | |
516 | } | |
517 | ||
628edaa5 PM |
518 | /* |
519 | * Variables for stuttering, which means to periodically pause and | |
520 | * restart testing in order to catch bugs that appear when load is | |
521 | * suddenly applied to or removed from the system. | |
522 | */ | |
523 | static struct task_struct *stutter_task; | |
524 | static int stutter_pause_test; | |
525 | static int stutter; | |
526 | ||
527 | /* | |
528 | * Block until the stutter interval ends. This must be called periodically | |
529 | * by all running kthreads that need to be subject to stuttering. | |
530 | */ | |
531 | void stutter_wait(const char *title) | |
532 | { | |
533 | while (ACCESS_ONCE(stutter_pause_test) || | |
534 | (torture_runnable && !ACCESS_ONCE(*torture_runnable))) { | |
535 | if (stutter_pause_test) | |
536 | schedule_timeout_interruptible(1); | |
537 | else | |
538 | schedule_timeout_interruptible(round_jiffies_relative(HZ)); | |
539 | torture_shutdown_absorb(title); | |
540 | } | |
541 | } | |
542 | EXPORT_SYMBOL_GPL(stutter_wait); | |
543 | ||
544 | /* | |
545 | * Cause the torture test to "stutter", starting and stopping all | |
546 | * threads periodically. | |
547 | */ | |
548 | static int torture_stutter(void *arg) | |
549 | { | |
550 | VERBOSE_TOROUT_STRING("torture_stutter task started"); | |
551 | do { | |
552 | if (!torture_must_stop()) { | |
553 | schedule_timeout_interruptible(stutter); | |
554 | ACCESS_ONCE(stutter_pause_test) = 1; | |
555 | } | |
556 | if (!torture_must_stop()) | |
557 | schedule_timeout_interruptible(stutter); | |
558 | ACCESS_ONCE(stutter_pause_test) = 0; | |
559 | torture_shutdown_absorb("torture_stutter"); | |
560 | } while (!torture_must_stop()); | |
7fafaac5 | 561 | torture_kthread_stopping("torture_stutter"); |
628edaa5 PM |
562 | return 0; |
563 | } | |
564 | ||
565 | /* | |
566 | * Initialize and kick off the torture_stutter kthread. | |
567 | */ | |
568 | int torture_stutter_init(int s) | |
569 | { | |
570 | int ret; | |
571 | ||
572 | stutter = s; | |
47cf29b9 PM |
573 | ret = torture_create_kthread(torture_stutter, NULL, stutter_task); |
574 | return ret; | |
628edaa5 PM |
575 | } |
576 | EXPORT_SYMBOL_GPL(torture_stutter_init); | |
577 | ||
578 | /* | |
579 | * Cleanup after the torture_stutter kthread. | |
580 | */ | |
bfefc73a | 581 | static void torture_stutter_cleanup(void) |
628edaa5 PM |
582 | { |
583 | if (!stutter_task) | |
584 | return; | |
585 | VERBOSE_TOROUT_STRING("Stopping torture_stutter task"); | |
586 | kthread_stop(stutter_task); | |
587 | stutter_task = NULL; | |
588 | } | |
628edaa5 | 589 | |
b5daa8f3 PM |
590 | /* |
591 | * Initialize torture module. Please note that this is -not- invoked via | |
592 | * the usual module_init() mechanism, but rather by an explicit call from | |
593 | * the client torture module. This call must be paired with a later | |
594 | * torture_init_end(). | |
628edaa5 PM |
595 | * |
596 | * The runnable parameter points to a flag that controls whether or not | |
597 | * the test is currently runnable. If there is no such flag, pass in NULL. | |
b5daa8f3 | 598 | */ |
628edaa5 | 599 | void __init torture_init_begin(char *ttype, bool v, int *runnable) |
b5daa8f3 PM |
600 | { |
601 | mutex_lock(&fullstop_mutex); | |
602 | torture_type = ttype; | |
603 | verbose = v; | |
628edaa5 | 604 | torture_runnable = runnable; |
36970bb9 | 605 | fullstop = FULLSTOP_DONTSTOP; |
b5daa8f3 PM |
606 | |
607 | } | |
608 | EXPORT_SYMBOL_GPL(torture_init_begin); | |
609 | ||
610 | /* | |
611 | * Tell the torture module that initialization is complete. | |
612 | */ | |
613 | void __init torture_init_end(void) | |
614 | { | |
615 | mutex_unlock(&fullstop_mutex); | |
4622b487 | 616 | register_reboot_notifier(&torture_shutdown_nb); |
b5daa8f3 PM |
617 | } |
618 | EXPORT_SYMBOL_GPL(torture_init_end); | |
cc47ae08 PM |
619 | |
620 | /* | |
621 | * Clean up torture module. Please note that this is -not- invoked via | |
622 | * the usual module_exit() mechanism, but rather by an explicit call from | |
623 | * the client torture module. Returns true if a race with system shutdown | |
bfefc73a PM |
624 | * is detected, otherwise, all kthreads started by functions in this file |
625 | * will be shut down. | |
cc47ae08 PM |
626 | * |
627 | * This must be called before the caller starts shutting down its own | |
628 | * kthreads. | |
629 | */ | |
630 | bool torture_cleanup(void) | |
631 | { | |
632 | mutex_lock(&fullstop_mutex); | |
57a2fe90 | 633 | if (ACCESS_ONCE(fullstop) == FULLSTOP_SHUTDOWN) { |
cc47ae08 PM |
634 | pr_warn("Concurrent rmmod and shutdown illegal!\n"); |
635 | mutex_unlock(&fullstop_mutex); | |
636 | schedule_timeout_uninterruptible(10); | |
637 | return true; | |
638 | } | |
57a2fe90 | 639 | ACCESS_ONCE(fullstop) = FULLSTOP_RMMOD; |
cc47ae08 | 640 | mutex_unlock(&fullstop_mutex); |
bfefc73a | 641 | torture_shutdown_cleanup(); |
cc47ae08 | 642 | torture_shuffle_cleanup(); |
bfefc73a | 643 | torture_stutter_cleanup(); |
cc47ae08 PM |
644 | torture_onoff_cleanup(); |
645 | return false; | |
646 | } | |
647 | EXPORT_SYMBOL_GPL(torture_cleanup); | |
36970bb9 PM |
648 | |
649 | /* | |
650 | * Is it time for the current torture test to stop? | |
651 | */ | |
652 | bool torture_must_stop(void) | |
653 | { | |
654 | return torture_must_stop_irq() || kthread_should_stop(); | |
655 | } | |
656 | EXPORT_SYMBOL_GPL(torture_must_stop); | |
657 | ||
658 | /* | |
659 | * Is it time for the current torture test to stop? This is the irq-safe | |
660 | * version, hence no check for kthread_should_stop(). | |
661 | */ | |
662 | bool torture_must_stop_irq(void) | |
663 | { | |
57a2fe90 | 664 | return ACCESS_ONCE(fullstop) != FULLSTOP_DONTSTOP; |
36970bb9 PM |
665 | } |
666 | EXPORT_SYMBOL_GPL(torture_must_stop_irq); | |
7fafaac5 PM |
667 | |
668 | /* | |
669 | * Each kthread must wait for kthread_should_stop() before returning from | |
670 | * its top-level function, otherwise segfaults ensue. This function | |
671 | * prints a "stopping" message and waits for kthread_should_stop(), and | |
672 | * should be called from all torture kthreads immediately prior to | |
673 | * returning. | |
674 | */ | |
675 | void torture_kthread_stopping(char *title) | |
676 | { | |
0d6821d5 PM |
677 | char buf[128]; |
678 | ||
679 | snprintf(buf, sizeof(buf), "Stopping %s", title); | |
680 | VERBOSE_TOROUT_STRING(buf); | |
7fafaac5 PM |
681 | while (!kthread_should_stop()) { |
682 | torture_shutdown_absorb(title); | |
683 | schedule_timeout_uninterruptible(1); | |
684 | } | |
685 | } | |
686 | EXPORT_SYMBOL_GPL(torture_kthread_stopping); | |
47cf29b9 PM |
687 | |
688 | /* | |
689 | * Create a generic torture kthread that is immediately runnable. If you | |
690 | * need the kthread to be stopped so that you can do something to it before | |
691 | * it starts, you will need to open-code your own. | |
692 | */ | |
693 | int _torture_create_kthread(int (*fn)(void *arg), void *arg, char *s, char *m, | |
694 | char *f, struct task_struct **tp) | |
695 | { | |
696 | int ret = 0; | |
697 | ||
698 | VERBOSE_TOROUT_STRING(m); | |
699 | *tp = kthread_run(fn, arg, s); | |
700 | if (IS_ERR(*tp)) { | |
701 | ret = PTR_ERR(*tp); | |
702 | VERBOSE_TOROUT_ERRSTRING(f); | |
703 | *tp = NULL; | |
704 | } | |
705 | torture_shuffle_task_register(*tp); | |
706 | return ret; | |
707 | } | |
708 | EXPORT_SYMBOL_GPL(_torture_create_kthread); | |
9c029b86 PM |
709 | |
710 | /* | |
711 | * Stop a generic kthread, emitting a message. | |
712 | */ | |
713 | void _torture_stop_kthread(char *m, struct task_struct **tp) | |
714 | { | |
715 | if (*tp == NULL) | |
716 | return; | |
717 | VERBOSE_TOROUT_STRING(m); | |
718 | kthread_stop(*tp); | |
719 | *tp = NULL; | |
720 | } | |
721 | EXPORT_SYMBOL_GPL(_torture_stop_kthread); |