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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> | |
e6017571 | 33 | #include <linux/sched/clock.h> |
51b1130e PM |
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> | |
31257c3c | 47 | #include <linux/ktime.h> |
51b1130e PM |
48 | #include <asm/byteorder.h> |
49 | #include <linux/torture.h> | |
dac95906 | 50 | #include "rcu/rcu.h" |
51b1130e PM |
51 | |
52 | MODULE_LICENSE("GPL"); | |
53 | MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com>"); | |
54 | ||
b5daa8f3 PM |
55 | static char *torture_type; |
56 | static bool verbose; | |
57 | ||
36970bb9 PM |
58 | /* Mediate rmmod and system shutdown. Concurrent rmmod & shutdown illegal! */ |
59 | #define FULLSTOP_DONTSTOP 0 /* Normal operation. */ | |
60 | #define FULLSTOP_SHUTDOWN 1 /* System shutdown with torture running. */ | |
61 | #define FULLSTOP_RMMOD 2 /* Normal rmmod of torture. */ | |
62 | static int fullstop = FULLSTOP_RMMOD; | |
4622b487 | 63 | static DEFINE_MUTEX(fullstop_mutex); |
628edaa5 | 64 | static int *torture_runnable; |
f67a3356 | 65 | |
2e9e8081 PM |
66 | #ifdef CONFIG_HOTPLUG_CPU |
67 | ||
68 | /* | |
69 | * Variables for online-offline handling. Only present if CPU hotplug | |
70 | * is enabled, otherwise does nothing. | |
71 | */ | |
72 | ||
73 | static struct task_struct *onoff_task; | |
74 | static long onoff_holdoff; | |
75 | static long onoff_interval; | |
76 | static long n_offline_attempts; | |
77 | static long n_offline_successes; | |
78 | static unsigned long sum_offline; | |
79 | static int min_offline = -1; | |
80 | static int max_offline; | |
81 | static long n_online_attempts; | |
82 | static long n_online_successes; | |
83 | static unsigned long sum_online; | |
84 | static int min_online = -1; | |
85 | static int max_online; | |
86 | ||
d95f5ba9 PM |
87 | /* |
88 | * Attempt to take a CPU offline. Return false if the CPU is already | |
89 | * offline or if it is not subject to CPU-hotplug operations. The | |
90 | * caller can detect other failures by looking at the statistics. | |
91 | */ | |
92 | bool torture_offline(int cpu, long *n_offl_attempts, long *n_offl_successes, | |
93 | unsigned long *sum_offl, int *min_offl, int *max_offl) | |
94 | { | |
95 | unsigned long delta; | |
96 | int ret; | |
97 | unsigned long starttime; | |
98 | ||
99 | if (!cpu_online(cpu) || !cpu_is_hotpluggable(cpu)) | |
100 | return false; | |
101 | ||
102 | if (verbose) | |
103 | pr_alert("%s" TORTURE_FLAG | |
104 | "torture_onoff task: offlining %d\n", | |
105 | torture_type, cpu); | |
106 | starttime = jiffies; | |
107 | (*n_offl_attempts)++; | |
108 | ret = cpu_down(cpu); | |
109 | if (ret) { | |
110 | if (verbose) | |
111 | pr_alert("%s" TORTURE_FLAG | |
112 | "torture_onoff task: offline %d failed: errno %d\n", | |
113 | torture_type, cpu, ret); | |
114 | } else { | |
115 | if (verbose) | |
116 | pr_alert("%s" TORTURE_FLAG | |
117 | "torture_onoff task: offlined %d\n", | |
118 | torture_type, cpu); | |
119 | (*n_offl_successes)++; | |
120 | delta = jiffies - starttime; | |
a2b2df20 | 121 | *sum_offl += delta; |
d95f5ba9 PM |
122 | if (*min_offl < 0) { |
123 | *min_offl = delta; | |
124 | *max_offl = delta; | |
125 | } | |
126 | if (*min_offl > delta) | |
127 | *min_offl = delta; | |
128 | if (*max_offl < delta) | |
129 | *max_offl = delta; | |
130 | } | |
131 | ||
132 | return true; | |
133 | } | |
134 | EXPORT_SYMBOL_GPL(torture_offline); | |
135 | ||
136 | /* | |
137 | * Attempt to bring a CPU online. Return false if the CPU is already | |
138 | * online or if it is not subject to CPU-hotplug operations. The | |
139 | * caller can detect other failures by looking at the statistics. | |
140 | */ | |
141 | bool torture_online(int cpu, long *n_onl_attempts, long *n_onl_successes, | |
142 | unsigned long *sum_onl, int *min_onl, int *max_onl) | |
143 | { | |
144 | unsigned long delta; | |
145 | int ret; | |
146 | unsigned long starttime; | |
147 | ||
148 | if (cpu_online(cpu) || !cpu_is_hotpluggable(cpu)) | |
149 | return false; | |
150 | ||
151 | if (verbose) | |
152 | pr_alert("%s" TORTURE_FLAG | |
153 | "torture_onoff task: onlining %d\n", | |
154 | torture_type, cpu); | |
155 | starttime = jiffies; | |
156 | (*n_onl_attempts)++; | |
157 | ret = cpu_up(cpu); | |
158 | if (ret) { | |
159 | if (verbose) | |
160 | pr_alert("%s" TORTURE_FLAG | |
161 | "torture_onoff task: online %d failed: errno %d\n", | |
162 | torture_type, cpu, ret); | |
163 | } else { | |
164 | if (verbose) | |
165 | pr_alert("%s" TORTURE_FLAG | |
166 | "torture_onoff task: onlined %d\n", | |
167 | torture_type, cpu); | |
168 | (*n_onl_successes)++; | |
169 | delta = jiffies - starttime; | |
170 | *sum_onl += delta; | |
171 | if (*min_onl < 0) { | |
172 | *min_onl = delta; | |
173 | *max_onl = delta; | |
174 | } | |
175 | if (*min_onl > delta) | |
176 | *min_onl = delta; | |
177 | if (*max_onl < delta) | |
178 | *max_onl = delta; | |
179 | } | |
180 | ||
181 | return true; | |
182 | } | |
183 | EXPORT_SYMBOL_GPL(torture_online); | |
184 | ||
2e9e8081 PM |
185 | /* |
186 | * Execute random CPU-hotplug operations at the interval specified | |
187 | * by the onoff_interval. | |
188 | */ | |
189 | static int | |
190 | torture_onoff(void *arg) | |
191 | { | |
192 | int cpu; | |
2e9e8081 PM |
193 | int maxcpu = -1; |
194 | DEFINE_TORTURE_RANDOM(rand); | |
2e9e8081 PM |
195 | |
196 | VERBOSE_TOROUT_STRING("torture_onoff task started"); | |
197 | for_each_online_cpu(cpu) | |
198 | maxcpu = cpu; | |
199 | WARN_ON(maxcpu < 0); | |
750db0f5 BF |
200 | |
201 | if (maxcpu == 0) { | |
202 | VERBOSE_TOROUT_STRING("Only one CPU, so CPU-hotplug testing is disabled"); | |
203 | goto stop; | |
204 | } | |
205 | ||
2e9e8081 PM |
206 | if (onoff_holdoff > 0) { |
207 | VERBOSE_TOROUT_STRING("torture_onoff begin holdoff"); | |
208 | schedule_timeout_interruptible(onoff_holdoff); | |
209 | VERBOSE_TOROUT_STRING("torture_onoff end holdoff"); | |
210 | } | |
211 | while (!torture_must_stop()) { | |
212 | cpu = (torture_random(&rand) >> 4) % (maxcpu + 1); | |
d95f5ba9 PM |
213 | if (!torture_offline(cpu, |
214 | &n_offline_attempts, &n_offline_successes, | |
215 | &sum_offline, &min_offline, &max_offline)) | |
216 | torture_online(cpu, | |
217 | &n_online_attempts, &n_online_successes, | |
218 | &sum_online, &min_online, &max_online); | |
2e9e8081 PM |
219 | schedule_timeout_interruptible(onoff_interval); |
220 | } | |
750db0f5 BF |
221 | |
222 | stop: | |
7fafaac5 | 223 | torture_kthread_stopping("torture_onoff"); |
2e9e8081 PM |
224 | return 0; |
225 | } | |
226 | ||
227 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ | |
228 | ||
229 | /* | |
230 | * Initiate online-offline handling. | |
231 | */ | |
232 | int torture_onoff_init(long ooholdoff, long oointerval) | |
233 | { | |
47cf29b9 | 234 | int ret = 0; |
2e9e8081 | 235 | |
47cf29b9 | 236 | #ifdef CONFIG_HOTPLUG_CPU |
2e9e8081 PM |
237 | onoff_holdoff = ooholdoff; |
238 | onoff_interval = oointerval; | |
239 | if (onoff_interval <= 0) | |
240 | return 0; | |
47cf29b9 | 241 | ret = torture_create_kthread(torture_onoff, NULL, onoff_task); |
2e9e8081 | 242 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ |
47cf29b9 | 243 | return ret; |
2e9e8081 PM |
244 | } |
245 | EXPORT_SYMBOL_GPL(torture_onoff_init); | |
246 | ||
247 | /* | |
248 | * Clean up after online/offline testing. | |
249 | */ | |
cc47ae08 | 250 | static void torture_onoff_cleanup(void) |
2e9e8081 PM |
251 | { |
252 | #ifdef CONFIG_HOTPLUG_CPU | |
253 | if (onoff_task == NULL) | |
254 | return; | |
255 | VERBOSE_TOROUT_STRING("Stopping torture_onoff task"); | |
256 | kthread_stop(onoff_task); | |
257 | onoff_task = NULL; | |
258 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ | |
259 | } | |
260 | EXPORT_SYMBOL_GPL(torture_onoff_cleanup); | |
261 | ||
262 | /* | |
263 | * Print online/offline testing statistics. | |
264 | */ | |
eea203fe | 265 | void torture_onoff_stats(void) |
2e9e8081 PM |
266 | { |
267 | #ifdef CONFIG_HOTPLUG_CPU | |
eea203fe JP |
268 | pr_cont("onoff: %ld/%ld:%ld/%ld %d,%d:%d,%d %lu:%lu (HZ=%d) ", |
269 | n_online_successes, n_online_attempts, | |
270 | n_offline_successes, n_offline_attempts, | |
271 | min_online, max_online, | |
272 | min_offline, max_offline, | |
273 | sum_online, sum_offline, HZ); | |
2e9e8081 | 274 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ |
2e9e8081 PM |
275 | } |
276 | EXPORT_SYMBOL_GPL(torture_onoff_stats); | |
277 | ||
278 | /* | |
279 | * Were all the online/offline operations successful? | |
280 | */ | |
281 | bool torture_onoff_failures(void) | |
282 | { | |
283 | #ifdef CONFIG_HOTPLUG_CPU | |
284 | return n_online_successes != n_online_attempts || | |
285 | n_offline_successes != n_offline_attempts; | |
286 | #else /* #ifdef CONFIG_HOTPLUG_CPU */ | |
287 | return false; | |
288 | #endif /* #else #ifdef CONFIG_HOTPLUG_CPU */ | |
289 | } | |
290 | EXPORT_SYMBOL_GPL(torture_onoff_failures); | |
291 | ||
51b1130e PM |
292 | #define TORTURE_RANDOM_MULT 39916801 /* prime */ |
293 | #define TORTURE_RANDOM_ADD 479001701 /* prime */ | |
294 | #define TORTURE_RANDOM_REFRESH 10000 | |
295 | ||
296 | /* | |
297 | * Crude but fast random-number generator. Uses a linear congruential | |
298 | * generator, with occasional help from cpu_clock(). | |
299 | */ | |
300 | unsigned long | |
301 | torture_random(struct torture_random_state *trsp) | |
302 | { | |
303 | if (--trsp->trs_count < 0) { | |
304 | trsp->trs_state += (unsigned long)local_clock(); | |
305 | trsp->trs_count = TORTURE_RANDOM_REFRESH; | |
306 | } | |
307 | trsp->trs_state = trsp->trs_state * TORTURE_RANDOM_MULT + | |
308 | TORTURE_RANDOM_ADD; | |
309 | return swahw32(trsp->trs_state); | |
310 | } | |
311 | EXPORT_SYMBOL_GPL(torture_random); | |
f67a3356 | 312 | |
3808dc9f PM |
313 | /* |
314 | * Variables for shuffling. The idea is to ensure that each CPU stays | |
315 | * idle for an extended period to test interactions with dyntick idle, | |
b564d62e | 316 | * as well as interactions with any per-CPU variables. |
3808dc9f PM |
317 | */ |
318 | struct shuffle_task { | |
319 | struct list_head st_l; | |
320 | struct task_struct *st_t; | |
321 | }; | |
322 | ||
323 | static long shuffle_interval; /* In jiffies. */ | |
324 | static struct task_struct *shuffler_task; | |
325 | static cpumask_var_t shuffle_tmp_mask; | |
326 | static int shuffle_idle_cpu; /* Force all torture tasks off this CPU */ | |
327 | static struct list_head shuffle_task_list = LIST_HEAD_INIT(shuffle_task_list); | |
328 | static DEFINE_MUTEX(shuffle_task_mutex); | |
329 | ||
330 | /* | |
331 | * Register a task to be shuffled. If there is no memory, just splat | |
332 | * and don't bother registering. | |
333 | */ | |
334 | void torture_shuffle_task_register(struct task_struct *tp) | |
335 | { | |
336 | struct shuffle_task *stp; | |
337 | ||
338 | if (WARN_ON_ONCE(tp == NULL)) | |
339 | return; | |
340 | stp = kmalloc(sizeof(*stp), GFP_KERNEL); | |
341 | if (WARN_ON_ONCE(stp == NULL)) | |
342 | return; | |
343 | stp->st_t = tp; | |
344 | mutex_lock(&shuffle_task_mutex); | |
345 | list_add(&stp->st_l, &shuffle_task_list); | |
346 | mutex_unlock(&shuffle_task_mutex); | |
347 | } | |
348 | EXPORT_SYMBOL_GPL(torture_shuffle_task_register); | |
349 | ||
350 | /* | |
351 | * Unregister all tasks, for example, at the end of the torture run. | |
352 | */ | |
353 | static void torture_shuffle_task_unregister_all(void) | |
354 | { | |
355 | struct shuffle_task *stp; | |
356 | struct shuffle_task *p; | |
357 | ||
358 | mutex_lock(&shuffle_task_mutex); | |
359 | list_for_each_entry_safe(stp, p, &shuffle_task_list, st_l) { | |
360 | list_del(&stp->st_l); | |
361 | kfree(stp); | |
362 | } | |
363 | mutex_unlock(&shuffle_task_mutex); | |
364 | } | |
365 | ||
366 | /* Shuffle tasks such that we allow shuffle_idle_cpu to become idle. | |
367 | * A special case is when shuffle_idle_cpu = -1, in which case we allow | |
368 | * the tasks to run on all CPUs. | |
369 | */ | |
370 | static void torture_shuffle_tasks(void) | |
371 | { | |
372 | struct shuffle_task *stp; | |
373 | ||
374 | cpumask_setall(shuffle_tmp_mask); | |
375 | get_online_cpus(); | |
376 | ||
377 | /* No point in shuffling if there is only one online CPU (ex: UP) */ | |
378 | if (num_online_cpus() == 1) { | |
379 | put_online_cpus(); | |
380 | return; | |
381 | } | |
382 | ||
383 | /* Advance to the next CPU. Upon overflow, don't idle any CPUs. */ | |
384 | shuffle_idle_cpu = cpumask_next(shuffle_idle_cpu, shuffle_tmp_mask); | |
385 | if (shuffle_idle_cpu >= nr_cpu_ids) | |
386 | shuffle_idle_cpu = -1; | |
5ed63b19 | 387 | else |
3808dc9f | 388 | cpumask_clear_cpu(shuffle_idle_cpu, shuffle_tmp_mask); |
3808dc9f PM |
389 | |
390 | mutex_lock(&shuffle_task_mutex); | |
391 | list_for_each_entry(stp, &shuffle_task_list, st_l) | |
392 | set_cpus_allowed_ptr(stp->st_t, shuffle_tmp_mask); | |
393 | mutex_unlock(&shuffle_task_mutex); | |
394 | ||
395 | put_online_cpus(); | |
396 | } | |
397 | ||
398 | /* Shuffle tasks across CPUs, with the intent of allowing each CPU in the | |
399 | * system to become idle at a time and cut off its timer ticks. This is meant | |
400 | * to test the support for such tickless idle CPU in RCU. | |
401 | */ | |
402 | static int torture_shuffle(void *arg) | |
403 | { | |
404 | VERBOSE_TOROUT_STRING("torture_shuffle task started"); | |
405 | do { | |
406 | schedule_timeout_interruptible(shuffle_interval); | |
407 | torture_shuffle_tasks(); | |
408 | torture_shutdown_absorb("torture_shuffle"); | |
409 | } while (!torture_must_stop()); | |
7fafaac5 | 410 | torture_kthread_stopping("torture_shuffle"); |
3808dc9f PM |
411 | return 0; |
412 | } | |
413 | ||
414 | /* | |
415 | * Start the shuffler, with shuffint in jiffies. | |
416 | */ | |
417 | int torture_shuffle_init(long shuffint) | |
418 | { | |
3808dc9f PM |
419 | shuffle_interval = shuffint; |
420 | ||
421 | shuffle_idle_cpu = -1; | |
422 | ||
423 | if (!alloc_cpumask_var(&shuffle_tmp_mask, GFP_KERNEL)) { | |
424 | VERBOSE_TOROUT_ERRSTRING("Failed to alloc mask"); | |
425 | return -ENOMEM; | |
426 | } | |
427 | ||
428 | /* Create the shuffler thread */ | |
47cf29b9 | 429 | return torture_create_kthread(torture_shuffle, NULL, shuffler_task); |
3808dc9f PM |
430 | } |
431 | EXPORT_SYMBOL_GPL(torture_shuffle_init); | |
432 | ||
433 | /* | |
434 | * Stop the shuffling. | |
435 | */ | |
cc47ae08 | 436 | static void torture_shuffle_cleanup(void) |
3808dc9f PM |
437 | { |
438 | torture_shuffle_task_unregister_all(); | |
439 | if (shuffler_task) { | |
440 | VERBOSE_TOROUT_STRING("Stopping torture_shuffle task"); | |
441 | kthread_stop(shuffler_task); | |
442 | free_cpumask_var(shuffle_tmp_mask); | |
443 | } | |
444 | shuffler_task = NULL; | |
445 | } | |
446 | EXPORT_SYMBOL_GPL(torture_shuffle_cleanup); | |
447 | ||
e991dbc0 PM |
448 | /* |
449 | * Variables for auto-shutdown. This allows "lights out" torture runs | |
450 | * to be fully scripted. | |
451 | */ | |
e991dbc0 | 452 | static struct task_struct *shutdown_task; |
31257c3c | 453 | static ktime_t shutdown_time; /* time to system shutdown. */ |
e991dbc0 PM |
454 | static void (*torture_shutdown_hook)(void); |
455 | ||
f67a3356 PM |
456 | /* |
457 | * Absorb kthreads into a kernel function that won't return, so that | |
458 | * they won't ever access module text or data again. | |
459 | */ | |
460 | void torture_shutdown_absorb(const char *title) | |
461 | { | |
7d0ae808 | 462 | while (READ_ONCE(fullstop) == FULLSTOP_SHUTDOWN) { |
4622b487 PM |
463 | pr_notice("torture thread %s parking due to system shutdown\n", |
464 | title); | |
f67a3356 PM |
465 | schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT); |
466 | } | |
467 | } | |
468 | EXPORT_SYMBOL_GPL(torture_shutdown_absorb); | |
b5daa8f3 | 469 | |
e991dbc0 PM |
470 | /* |
471 | * Cause the torture test to shutdown the system after the test has | |
472 | * run for the time specified by the shutdown_secs parameter. | |
473 | */ | |
474 | static int torture_shutdown(void *arg) | |
475 | { | |
31257c3c | 476 | ktime_t ktime_snap; |
e991dbc0 PM |
477 | |
478 | VERBOSE_TOROUT_STRING("torture_shutdown task started"); | |
31257c3c PM |
479 | ktime_snap = ktime_get(); |
480 | while (ktime_before(ktime_snap, shutdown_time) && | |
e991dbc0 | 481 | !torture_must_stop()) { |
e991dbc0 PM |
482 | if (verbose) |
483 | pr_alert("%s" TORTURE_FLAG | |
31257c3c PM |
484 | "torture_shutdown task: %llu ms remaining\n", |
485 | torture_type, | |
486 | ktime_ms_delta(shutdown_time, ktime_snap)); | |
487 | set_current_state(TASK_INTERRUPTIBLE); | |
488 | schedule_hrtimeout(&shutdown_time, HRTIMER_MODE_ABS); | |
489 | ktime_snap = ktime_get(); | |
e991dbc0 PM |
490 | } |
491 | if (torture_must_stop()) { | |
7fafaac5 | 492 | torture_kthread_stopping("torture_shutdown"); |
e991dbc0 PM |
493 | return 0; |
494 | } | |
495 | ||
496 | /* OK, shut down the system. */ | |
497 | ||
498 | VERBOSE_TOROUT_STRING("torture_shutdown task shutting down system"); | |
499 | shutdown_task = NULL; /* Avoid self-kill deadlock. */ | |
f881825a PM |
500 | if (torture_shutdown_hook) |
501 | torture_shutdown_hook(); | |
502 | else | |
503 | VERBOSE_TOROUT_STRING("No torture_shutdown_hook(), skipping."); | |
dac95906 | 504 | rcu_ftrace_dump(DUMP_ALL); |
e991dbc0 PM |
505 | kernel_power_off(); /* Shut down the system. */ |
506 | return 0; | |
507 | } | |
508 | ||
509 | /* | |
510 | * Start up the shutdown task. | |
511 | */ | |
512 | int torture_shutdown_init(int ssecs, void (*cleanup)(void)) | |
513 | { | |
47cf29b9 | 514 | int ret = 0; |
e991dbc0 | 515 | |
e991dbc0 | 516 | torture_shutdown_hook = cleanup; |
31257c3c PM |
517 | if (ssecs > 0) { |
518 | shutdown_time = ktime_add(ktime_get(), ktime_set(ssecs, 0)); | |
47cf29b9 PM |
519 | ret = torture_create_kthread(torture_shutdown, NULL, |
520 | shutdown_task); | |
e991dbc0 | 521 | } |
47cf29b9 | 522 | return ret; |
e991dbc0 PM |
523 | } |
524 | EXPORT_SYMBOL_GPL(torture_shutdown_init); | |
525 | ||
4622b487 PM |
526 | /* |
527 | * Detect and respond to a system shutdown. | |
528 | */ | |
529 | static int torture_shutdown_notify(struct notifier_block *unused1, | |
530 | unsigned long unused2, void *unused3) | |
531 | { | |
532 | mutex_lock(&fullstop_mutex); | |
7d0ae808 | 533 | if (READ_ONCE(fullstop) == FULLSTOP_DONTSTOP) { |
fac480ef | 534 | VERBOSE_TOROUT_STRING("Unscheduled system shutdown detected"); |
7d0ae808 | 535 | WRITE_ONCE(fullstop, FULLSTOP_SHUTDOWN); |
fac480ef | 536 | } else { |
4622b487 | 537 | pr_warn("Concurrent rmmod and shutdown illegal!\n"); |
fac480ef | 538 | } |
4622b487 PM |
539 | mutex_unlock(&fullstop_mutex); |
540 | return NOTIFY_DONE; | |
541 | } | |
542 | ||
543 | static struct notifier_block torture_shutdown_nb = { | |
544 | .notifier_call = torture_shutdown_notify, | |
545 | }; | |
546 | ||
bfefc73a PM |
547 | /* |
548 | * Shut down the shutdown task. Say what??? Heh! This can happen if | |
549 | * the torture module gets an rmmod before the shutdown time arrives. ;-) | |
550 | */ | |
551 | static void torture_shutdown_cleanup(void) | |
552 | { | |
553 | unregister_reboot_notifier(&torture_shutdown_nb); | |
554 | if (shutdown_task != NULL) { | |
555 | VERBOSE_TOROUT_STRING("Stopping torture_shutdown task"); | |
556 | kthread_stop(shutdown_task); | |
557 | } | |
558 | shutdown_task = NULL; | |
559 | } | |
560 | ||
628edaa5 PM |
561 | /* |
562 | * Variables for stuttering, which means to periodically pause and | |
563 | * restart testing in order to catch bugs that appear when load is | |
564 | * suddenly applied to or removed from the system. | |
565 | */ | |
566 | static struct task_struct *stutter_task; | |
567 | static int stutter_pause_test; | |
568 | static int stutter; | |
569 | ||
570 | /* | |
571 | * Block until the stutter interval ends. This must be called periodically | |
572 | * by all running kthreads that need to be subject to stuttering. | |
573 | */ | |
574 | void stutter_wait(const char *title) | |
575 | { | |
3836f533 | 576 | cond_resched_rcu_qs(); |
7d0ae808 PM |
577 | while (READ_ONCE(stutter_pause_test) || |
578 | (torture_runnable && !READ_ONCE(*torture_runnable))) { | |
628edaa5 | 579 | if (stutter_pause_test) |
7d0ae808 | 580 | if (READ_ONCE(stutter_pause_test) == 1) |
ab7d4505 PM |
581 | schedule_timeout_interruptible(1); |
582 | else | |
7d0ae808 | 583 | while (READ_ONCE(stutter_pause_test)) |
ab7d4505 | 584 | cond_resched(); |
628edaa5 PM |
585 | else |
586 | schedule_timeout_interruptible(round_jiffies_relative(HZ)); | |
587 | torture_shutdown_absorb(title); | |
588 | } | |
589 | } | |
590 | EXPORT_SYMBOL_GPL(stutter_wait); | |
591 | ||
592 | /* | |
593 | * Cause the torture test to "stutter", starting and stopping all | |
594 | * threads periodically. | |
595 | */ | |
596 | static int torture_stutter(void *arg) | |
597 | { | |
598 | VERBOSE_TOROUT_STRING("torture_stutter task started"); | |
599 | do { | |
600 | if (!torture_must_stop()) { | |
ab7d4505 PM |
601 | if (stutter > 1) { |
602 | schedule_timeout_interruptible(stutter - 1); | |
7d0ae808 | 603 | WRITE_ONCE(stutter_pause_test, 2); |
ab7d4505 PM |
604 | } |
605 | schedule_timeout_interruptible(1); | |
7d0ae808 | 606 | WRITE_ONCE(stutter_pause_test, 1); |
628edaa5 PM |
607 | } |
608 | if (!torture_must_stop()) | |
609 | schedule_timeout_interruptible(stutter); | |
7d0ae808 | 610 | WRITE_ONCE(stutter_pause_test, 0); |
628edaa5 PM |
611 | torture_shutdown_absorb("torture_stutter"); |
612 | } while (!torture_must_stop()); | |
7fafaac5 | 613 | torture_kthread_stopping("torture_stutter"); |
628edaa5 PM |
614 | return 0; |
615 | } | |
616 | ||
617 | /* | |
618 | * Initialize and kick off the torture_stutter kthread. | |
619 | */ | |
620 | int torture_stutter_init(int s) | |
621 | { | |
622 | int ret; | |
623 | ||
624 | stutter = s; | |
47cf29b9 PM |
625 | ret = torture_create_kthread(torture_stutter, NULL, stutter_task); |
626 | return ret; | |
628edaa5 PM |
627 | } |
628 | EXPORT_SYMBOL_GPL(torture_stutter_init); | |
629 | ||
630 | /* | |
631 | * Cleanup after the torture_stutter kthread. | |
632 | */ | |
bfefc73a | 633 | static void torture_stutter_cleanup(void) |
628edaa5 PM |
634 | { |
635 | if (!stutter_task) | |
636 | return; | |
637 | VERBOSE_TOROUT_STRING("Stopping torture_stutter task"); | |
638 | kthread_stop(stutter_task); | |
639 | stutter_task = NULL; | |
640 | } | |
628edaa5 | 641 | |
b5daa8f3 PM |
642 | /* |
643 | * Initialize torture module. Please note that this is -not- invoked via | |
644 | * the usual module_init() mechanism, but rather by an explicit call from | |
645 | * the client torture module. This call must be paired with a later | |
646 | * torture_init_end(). | |
628edaa5 PM |
647 | * |
648 | * The runnable parameter points to a flag that controls whether or not | |
649 | * the test is currently runnable. If there is no such flag, pass in NULL. | |
b5daa8f3 | 650 | */ |
2b3f8ffe | 651 | bool torture_init_begin(char *ttype, bool v, int *runnable) |
b5daa8f3 PM |
652 | { |
653 | mutex_lock(&fullstop_mutex); | |
5228084e | 654 | if (torture_type != NULL) { |
9eb5188a | 655 | pr_alert("torture_init_begin: Refusing %s init: %s running.\n", |
5228084e | 656 | ttype, torture_type); |
9eb5188a | 657 | pr_alert("torture_init_begin: One torture test at a time!\n"); |
5228084e PM |
658 | mutex_unlock(&fullstop_mutex); |
659 | return false; | |
660 | } | |
b5daa8f3 PM |
661 | torture_type = ttype; |
662 | verbose = v; | |
628edaa5 | 663 | torture_runnable = runnable; |
36970bb9 | 664 | fullstop = FULLSTOP_DONTSTOP; |
5228084e | 665 | return true; |
b5daa8f3 PM |
666 | } |
667 | EXPORT_SYMBOL_GPL(torture_init_begin); | |
668 | ||
669 | /* | |
670 | * Tell the torture module that initialization is complete. | |
671 | */ | |
2b3f8ffe | 672 | void torture_init_end(void) |
b5daa8f3 PM |
673 | { |
674 | mutex_unlock(&fullstop_mutex); | |
4622b487 | 675 | register_reboot_notifier(&torture_shutdown_nb); |
b5daa8f3 PM |
676 | } |
677 | EXPORT_SYMBOL_GPL(torture_init_end); | |
cc47ae08 PM |
678 | |
679 | /* | |
680 | * Clean up torture module. Please note that this is -not- invoked via | |
681 | * the usual module_exit() mechanism, but rather by an explicit call from | |
682 | * the client torture module. Returns true if a race with system shutdown | |
bfefc73a PM |
683 | * is detected, otherwise, all kthreads started by functions in this file |
684 | * will be shut down. | |
cc47ae08 PM |
685 | * |
686 | * This must be called before the caller starts shutting down its own | |
687 | * kthreads. | |
d36a7a0d DB |
688 | * |
689 | * Both torture_cleanup_begin() and torture_cleanup_end() must be paired, | |
690 | * in order to correctly perform the cleanup. They are separated because | |
691 | * threads can still need to reference the torture_type type, thus nullify | |
692 | * only after completing all other relevant calls. | |
cc47ae08 | 693 | */ |
d36a7a0d | 694 | bool torture_cleanup_begin(void) |
cc47ae08 PM |
695 | { |
696 | mutex_lock(&fullstop_mutex); | |
7d0ae808 | 697 | if (READ_ONCE(fullstop) == FULLSTOP_SHUTDOWN) { |
cc47ae08 PM |
698 | pr_warn("Concurrent rmmod and shutdown illegal!\n"); |
699 | mutex_unlock(&fullstop_mutex); | |
700 | schedule_timeout_uninterruptible(10); | |
701 | return true; | |
702 | } | |
7d0ae808 | 703 | WRITE_ONCE(fullstop, FULLSTOP_RMMOD); |
cc47ae08 | 704 | mutex_unlock(&fullstop_mutex); |
bfefc73a | 705 | torture_shutdown_cleanup(); |
cc47ae08 | 706 | torture_shuffle_cleanup(); |
bfefc73a | 707 | torture_stutter_cleanup(); |
cc47ae08 | 708 | torture_onoff_cleanup(); |
d36a7a0d DB |
709 | return false; |
710 | } | |
711 | EXPORT_SYMBOL_GPL(torture_cleanup_begin); | |
712 | ||
713 | void torture_cleanup_end(void) | |
714 | { | |
5228084e PM |
715 | mutex_lock(&fullstop_mutex); |
716 | torture_type = NULL; | |
717 | mutex_unlock(&fullstop_mutex); | |
cc47ae08 | 718 | } |
d36a7a0d | 719 | EXPORT_SYMBOL_GPL(torture_cleanup_end); |
36970bb9 PM |
720 | |
721 | /* | |
722 | * Is it time for the current torture test to stop? | |
723 | */ | |
724 | bool torture_must_stop(void) | |
725 | { | |
726 | return torture_must_stop_irq() || kthread_should_stop(); | |
727 | } | |
728 | EXPORT_SYMBOL_GPL(torture_must_stop); | |
729 | ||
730 | /* | |
731 | * Is it time for the current torture test to stop? This is the irq-safe | |
732 | * version, hence no check for kthread_should_stop(). | |
733 | */ | |
734 | bool torture_must_stop_irq(void) | |
735 | { | |
7d0ae808 | 736 | return READ_ONCE(fullstop) != FULLSTOP_DONTSTOP; |
36970bb9 PM |
737 | } |
738 | EXPORT_SYMBOL_GPL(torture_must_stop_irq); | |
7fafaac5 PM |
739 | |
740 | /* | |
741 | * Each kthread must wait for kthread_should_stop() before returning from | |
742 | * its top-level function, otherwise segfaults ensue. This function | |
743 | * prints a "stopping" message and waits for kthread_should_stop(), and | |
744 | * should be called from all torture kthreads immediately prior to | |
745 | * returning. | |
746 | */ | |
747 | void torture_kthread_stopping(char *title) | |
748 | { | |
0d6821d5 PM |
749 | char buf[128]; |
750 | ||
751 | snprintf(buf, sizeof(buf), "Stopping %s", title); | |
752 | VERBOSE_TOROUT_STRING(buf); | |
7fafaac5 PM |
753 | while (!kthread_should_stop()) { |
754 | torture_shutdown_absorb(title); | |
755 | schedule_timeout_uninterruptible(1); | |
756 | } | |
757 | } | |
758 | EXPORT_SYMBOL_GPL(torture_kthread_stopping); | |
47cf29b9 PM |
759 | |
760 | /* | |
761 | * Create a generic torture kthread that is immediately runnable. If you | |
762 | * need the kthread to be stopped so that you can do something to it before | |
763 | * it starts, you will need to open-code your own. | |
764 | */ | |
765 | int _torture_create_kthread(int (*fn)(void *arg), void *arg, char *s, char *m, | |
766 | char *f, struct task_struct **tp) | |
767 | { | |
768 | int ret = 0; | |
769 | ||
770 | VERBOSE_TOROUT_STRING(m); | |
6945915e | 771 | *tp = kthread_run(fn, arg, "%s", s); |
47cf29b9 PM |
772 | if (IS_ERR(*tp)) { |
773 | ret = PTR_ERR(*tp); | |
774 | VERBOSE_TOROUT_ERRSTRING(f); | |
775 | *tp = NULL; | |
776 | } | |
777 | torture_shuffle_task_register(*tp); | |
778 | return ret; | |
779 | } | |
780 | EXPORT_SYMBOL_GPL(_torture_create_kthread); | |
9c029b86 PM |
781 | |
782 | /* | |
783 | * Stop a generic kthread, emitting a message. | |
784 | */ | |
785 | void _torture_stop_kthread(char *m, struct task_struct **tp) | |
786 | { | |
787 | if (*tp == NULL) | |
788 | return; | |
789 | VERBOSE_TOROUT_STRING(m); | |
790 | kthread_stop(*tp); | |
791 | *tp = NULL; | |
792 | } | |
793 | EXPORT_SYMBOL_GPL(_torture_stop_kthread); |