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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 | ||
d95f5ba9 PM |
84 | /* |
85 | * Attempt to take a CPU offline. Return false if the CPU is already | |
86 | * offline or if it is not subject to CPU-hotplug operations. The | |
87 | * caller can detect other failures by looking at the statistics. | |
88 | */ | |
89 | bool torture_offline(int cpu, long *n_offl_attempts, long *n_offl_successes, | |
90 | unsigned long *sum_offl, int *min_offl, int *max_offl) | |
91 | { | |
92 | unsigned long delta; | |
93 | int ret; | |
94 | unsigned long starttime; | |
95 | ||
96 | if (!cpu_online(cpu) || !cpu_is_hotpluggable(cpu)) | |
97 | return false; | |
98 | ||
99 | if (verbose) | |
100 | pr_alert("%s" TORTURE_FLAG | |
101 | "torture_onoff task: offlining %d\n", | |
102 | torture_type, cpu); | |
103 | starttime = jiffies; | |
104 | (*n_offl_attempts)++; | |
105 | ret = cpu_down(cpu); | |
106 | if (ret) { | |
107 | if (verbose) | |
108 | pr_alert("%s" TORTURE_FLAG | |
109 | "torture_onoff task: offline %d failed: errno %d\n", | |
110 | torture_type, cpu, ret); | |
111 | } else { | |
112 | if (verbose) | |
113 | pr_alert("%s" TORTURE_FLAG | |
114 | "torture_onoff task: offlined %d\n", | |
115 | torture_type, cpu); | |
116 | (*n_offl_successes)++; | |
117 | delta = jiffies - starttime; | |
118 | sum_offl += delta; | |
119 | if (*min_offl < 0) { | |
120 | *min_offl = delta; | |
121 | *max_offl = delta; | |
122 | } | |
123 | if (*min_offl > delta) | |
124 | *min_offl = delta; | |
125 | if (*max_offl < delta) | |
126 | *max_offl = delta; | |
127 | } | |
128 | ||
129 | return true; | |
130 | } | |
131 | EXPORT_SYMBOL_GPL(torture_offline); | |
132 | ||
133 | /* | |
134 | * Attempt to bring a CPU online. Return false if the CPU is already | |
135 | * online or if it is not subject to CPU-hotplug operations. The | |
136 | * caller can detect other failures by looking at the statistics. | |
137 | */ | |
138 | bool torture_online(int cpu, long *n_onl_attempts, long *n_onl_successes, | |
139 | unsigned long *sum_onl, int *min_onl, int *max_onl) | |
140 | { | |
141 | unsigned long delta; | |
142 | int ret; | |
143 | unsigned long starttime; | |
144 | ||
145 | if (cpu_online(cpu) || !cpu_is_hotpluggable(cpu)) | |
146 | return false; | |
147 | ||
148 | if (verbose) | |
149 | pr_alert("%s" TORTURE_FLAG | |
150 | "torture_onoff task: onlining %d\n", | |
151 | torture_type, cpu); | |
152 | starttime = jiffies; | |
153 | (*n_onl_attempts)++; | |
154 | ret = cpu_up(cpu); | |
155 | if (ret) { | |
156 | if (verbose) | |
157 | pr_alert("%s" TORTURE_FLAG | |
158 | "torture_onoff task: online %d failed: errno %d\n", | |
159 | torture_type, cpu, ret); | |
160 | } else { | |
161 | if (verbose) | |
162 | pr_alert("%s" TORTURE_FLAG | |
163 | "torture_onoff task: onlined %d\n", | |
164 | torture_type, cpu); | |
165 | (*n_onl_successes)++; | |
166 | delta = jiffies - starttime; | |
167 | *sum_onl += delta; | |
168 | if (*min_onl < 0) { | |
169 | *min_onl = delta; | |
170 | *max_onl = delta; | |
171 | } | |
172 | if (*min_onl > delta) | |
173 | *min_onl = delta; | |
174 | if (*max_onl < delta) | |
175 | *max_onl = delta; | |
176 | } | |
177 | ||
178 | return true; | |
179 | } | |
180 | EXPORT_SYMBOL_GPL(torture_online); | |
181 | ||
2e9e8081 PM |
182 | /* |
183 | * Execute random CPU-hotplug operations at the interval specified | |
184 | * by the onoff_interval. | |
185 | */ | |
186 | static int | |
187 | torture_onoff(void *arg) | |
188 | { | |
189 | int cpu; | |
2e9e8081 PM |
190 | int maxcpu = -1; |
191 | DEFINE_TORTURE_RANDOM(rand); | |
2e9e8081 PM |
192 | |
193 | VERBOSE_TOROUT_STRING("torture_onoff task started"); | |
194 | for_each_online_cpu(cpu) | |
195 | maxcpu = cpu; | |
196 | WARN_ON(maxcpu < 0); | |
750db0f5 BF |
197 | |
198 | if (maxcpu == 0) { | |
199 | VERBOSE_TOROUT_STRING("Only one CPU, so CPU-hotplug testing is disabled"); | |
200 | goto stop; | |
201 | } | |
202 | ||
2e9e8081 PM |
203 | if (onoff_holdoff > 0) { |
204 | VERBOSE_TOROUT_STRING("torture_onoff begin holdoff"); | |
205 | schedule_timeout_interruptible(onoff_holdoff); | |
206 | VERBOSE_TOROUT_STRING("torture_onoff end holdoff"); | |
207 | } | |
208 | while (!torture_must_stop()) { | |
209 | cpu = (torture_random(&rand) >> 4) % (maxcpu + 1); | |
d95f5ba9 PM |
210 | if (!torture_offline(cpu, |
211 | &n_offline_attempts, &n_offline_successes, | |
212 | &sum_offline, &min_offline, &max_offline)) | |
213 | torture_online(cpu, | |
214 | &n_online_attempts, &n_online_successes, | |
215 | &sum_online, &min_online, &max_online); | |
2e9e8081 PM |
216 | schedule_timeout_interruptible(onoff_interval); |
217 | } | |
750db0f5 BF |
218 | |
219 | stop: | |
7fafaac5 | 220 | torture_kthread_stopping("torture_onoff"); |
2e9e8081 PM |
221 | return 0; |
222 | } | |
223 | ||
224 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ | |
225 | ||
226 | /* | |
227 | * Initiate online-offline handling. | |
228 | */ | |
229 | int torture_onoff_init(long ooholdoff, long oointerval) | |
230 | { | |
47cf29b9 | 231 | int ret = 0; |
2e9e8081 | 232 | |
47cf29b9 | 233 | #ifdef CONFIG_HOTPLUG_CPU |
2e9e8081 PM |
234 | onoff_holdoff = ooholdoff; |
235 | onoff_interval = oointerval; | |
236 | if (onoff_interval <= 0) | |
237 | return 0; | |
47cf29b9 | 238 | ret = torture_create_kthread(torture_onoff, NULL, onoff_task); |
2e9e8081 | 239 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ |
47cf29b9 | 240 | return ret; |
2e9e8081 PM |
241 | } |
242 | EXPORT_SYMBOL_GPL(torture_onoff_init); | |
243 | ||
244 | /* | |
245 | * Clean up after online/offline testing. | |
246 | */ | |
cc47ae08 | 247 | static void torture_onoff_cleanup(void) |
2e9e8081 PM |
248 | { |
249 | #ifdef CONFIG_HOTPLUG_CPU | |
250 | if (onoff_task == NULL) | |
251 | return; | |
252 | VERBOSE_TOROUT_STRING("Stopping torture_onoff task"); | |
253 | kthread_stop(onoff_task); | |
254 | onoff_task = NULL; | |
255 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ | |
256 | } | |
257 | EXPORT_SYMBOL_GPL(torture_onoff_cleanup); | |
258 | ||
259 | /* | |
260 | * Print online/offline testing statistics. | |
261 | */ | |
eea203fe | 262 | void torture_onoff_stats(void) |
2e9e8081 PM |
263 | { |
264 | #ifdef CONFIG_HOTPLUG_CPU | |
eea203fe JP |
265 | pr_cont("onoff: %ld/%ld:%ld/%ld %d,%d:%d,%d %lu:%lu (HZ=%d) ", |
266 | n_online_successes, n_online_attempts, | |
267 | n_offline_successes, n_offline_attempts, | |
268 | min_online, max_online, | |
269 | min_offline, max_offline, | |
270 | sum_online, sum_offline, HZ); | |
2e9e8081 | 271 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ |
2e9e8081 PM |
272 | } |
273 | EXPORT_SYMBOL_GPL(torture_onoff_stats); | |
274 | ||
275 | /* | |
276 | * Were all the online/offline operations successful? | |
277 | */ | |
278 | bool torture_onoff_failures(void) | |
279 | { | |
280 | #ifdef CONFIG_HOTPLUG_CPU | |
281 | return n_online_successes != n_online_attempts || | |
282 | n_offline_successes != n_offline_attempts; | |
283 | #else /* #ifdef CONFIG_HOTPLUG_CPU */ | |
284 | return false; | |
285 | #endif /* #else #ifdef CONFIG_HOTPLUG_CPU */ | |
286 | } | |
287 | EXPORT_SYMBOL_GPL(torture_onoff_failures); | |
288 | ||
51b1130e PM |
289 | #define TORTURE_RANDOM_MULT 39916801 /* prime */ |
290 | #define TORTURE_RANDOM_ADD 479001701 /* prime */ | |
291 | #define TORTURE_RANDOM_REFRESH 10000 | |
292 | ||
293 | /* | |
294 | * Crude but fast random-number generator. Uses a linear congruential | |
295 | * generator, with occasional help from cpu_clock(). | |
296 | */ | |
297 | unsigned long | |
298 | torture_random(struct torture_random_state *trsp) | |
299 | { | |
300 | if (--trsp->trs_count < 0) { | |
301 | trsp->trs_state += (unsigned long)local_clock(); | |
302 | trsp->trs_count = TORTURE_RANDOM_REFRESH; | |
303 | } | |
304 | trsp->trs_state = trsp->trs_state * TORTURE_RANDOM_MULT + | |
305 | TORTURE_RANDOM_ADD; | |
306 | return swahw32(trsp->trs_state); | |
307 | } | |
308 | EXPORT_SYMBOL_GPL(torture_random); | |
f67a3356 | 309 | |
3808dc9f PM |
310 | /* |
311 | * Variables for shuffling. The idea is to ensure that each CPU stays | |
312 | * idle for an extended period to test interactions with dyntick idle, | |
313 | * as well as interactions with any per-CPU varibles. | |
314 | */ | |
315 | struct shuffle_task { | |
316 | struct list_head st_l; | |
317 | struct task_struct *st_t; | |
318 | }; | |
319 | ||
320 | static long shuffle_interval; /* In jiffies. */ | |
321 | static struct task_struct *shuffler_task; | |
322 | static cpumask_var_t shuffle_tmp_mask; | |
323 | static int shuffle_idle_cpu; /* Force all torture tasks off this CPU */ | |
324 | static struct list_head shuffle_task_list = LIST_HEAD_INIT(shuffle_task_list); | |
325 | static DEFINE_MUTEX(shuffle_task_mutex); | |
326 | ||
327 | /* | |
328 | * Register a task to be shuffled. If there is no memory, just splat | |
329 | * and don't bother registering. | |
330 | */ | |
331 | void torture_shuffle_task_register(struct task_struct *tp) | |
332 | { | |
333 | struct shuffle_task *stp; | |
334 | ||
335 | if (WARN_ON_ONCE(tp == NULL)) | |
336 | return; | |
337 | stp = kmalloc(sizeof(*stp), GFP_KERNEL); | |
338 | if (WARN_ON_ONCE(stp == NULL)) | |
339 | return; | |
340 | stp->st_t = tp; | |
341 | mutex_lock(&shuffle_task_mutex); | |
342 | list_add(&stp->st_l, &shuffle_task_list); | |
343 | mutex_unlock(&shuffle_task_mutex); | |
344 | } | |
345 | EXPORT_SYMBOL_GPL(torture_shuffle_task_register); | |
346 | ||
347 | /* | |
348 | * Unregister all tasks, for example, at the end of the torture run. | |
349 | */ | |
350 | static void torture_shuffle_task_unregister_all(void) | |
351 | { | |
352 | struct shuffle_task *stp; | |
353 | struct shuffle_task *p; | |
354 | ||
355 | mutex_lock(&shuffle_task_mutex); | |
356 | list_for_each_entry_safe(stp, p, &shuffle_task_list, st_l) { | |
357 | list_del(&stp->st_l); | |
358 | kfree(stp); | |
359 | } | |
360 | mutex_unlock(&shuffle_task_mutex); | |
361 | } | |
362 | ||
363 | /* Shuffle tasks such that we allow shuffle_idle_cpu to become idle. | |
364 | * A special case is when shuffle_idle_cpu = -1, in which case we allow | |
365 | * the tasks to run on all CPUs. | |
366 | */ | |
367 | static void torture_shuffle_tasks(void) | |
368 | { | |
369 | struct shuffle_task *stp; | |
370 | ||
371 | cpumask_setall(shuffle_tmp_mask); | |
372 | get_online_cpus(); | |
373 | ||
374 | /* No point in shuffling if there is only one online CPU (ex: UP) */ | |
375 | if (num_online_cpus() == 1) { | |
376 | put_online_cpus(); | |
377 | return; | |
378 | } | |
379 | ||
380 | /* Advance to the next CPU. Upon overflow, don't idle any CPUs. */ | |
381 | shuffle_idle_cpu = cpumask_next(shuffle_idle_cpu, shuffle_tmp_mask); | |
382 | if (shuffle_idle_cpu >= nr_cpu_ids) | |
383 | shuffle_idle_cpu = -1; | |
5ed63b19 | 384 | else |
3808dc9f | 385 | cpumask_clear_cpu(shuffle_idle_cpu, shuffle_tmp_mask); |
3808dc9f PM |
386 | |
387 | mutex_lock(&shuffle_task_mutex); | |
388 | list_for_each_entry(stp, &shuffle_task_list, st_l) | |
389 | set_cpus_allowed_ptr(stp->st_t, shuffle_tmp_mask); | |
390 | mutex_unlock(&shuffle_task_mutex); | |
391 | ||
392 | put_online_cpus(); | |
393 | } | |
394 | ||
395 | /* Shuffle tasks across CPUs, with the intent of allowing each CPU in the | |
396 | * system to become idle at a time and cut off its timer ticks. This is meant | |
397 | * to test the support for such tickless idle CPU in RCU. | |
398 | */ | |
399 | static int torture_shuffle(void *arg) | |
400 | { | |
401 | VERBOSE_TOROUT_STRING("torture_shuffle task started"); | |
402 | do { | |
403 | schedule_timeout_interruptible(shuffle_interval); | |
404 | torture_shuffle_tasks(); | |
405 | torture_shutdown_absorb("torture_shuffle"); | |
406 | } while (!torture_must_stop()); | |
7fafaac5 | 407 | torture_kthread_stopping("torture_shuffle"); |
3808dc9f PM |
408 | return 0; |
409 | } | |
410 | ||
411 | /* | |
412 | * Start the shuffler, with shuffint in jiffies. | |
413 | */ | |
414 | int torture_shuffle_init(long shuffint) | |
415 | { | |
3808dc9f PM |
416 | shuffle_interval = shuffint; |
417 | ||
418 | shuffle_idle_cpu = -1; | |
419 | ||
420 | if (!alloc_cpumask_var(&shuffle_tmp_mask, GFP_KERNEL)) { | |
421 | VERBOSE_TOROUT_ERRSTRING("Failed to alloc mask"); | |
422 | return -ENOMEM; | |
423 | } | |
424 | ||
425 | /* Create the shuffler thread */ | |
47cf29b9 | 426 | return torture_create_kthread(torture_shuffle, NULL, shuffler_task); |
3808dc9f PM |
427 | } |
428 | EXPORT_SYMBOL_GPL(torture_shuffle_init); | |
429 | ||
430 | /* | |
431 | * Stop the shuffling. | |
432 | */ | |
cc47ae08 | 433 | static void torture_shuffle_cleanup(void) |
3808dc9f PM |
434 | { |
435 | torture_shuffle_task_unregister_all(); | |
436 | if (shuffler_task) { | |
437 | VERBOSE_TOROUT_STRING("Stopping torture_shuffle task"); | |
438 | kthread_stop(shuffler_task); | |
439 | free_cpumask_var(shuffle_tmp_mask); | |
440 | } | |
441 | shuffler_task = NULL; | |
442 | } | |
443 | EXPORT_SYMBOL_GPL(torture_shuffle_cleanup); | |
444 | ||
e991dbc0 PM |
445 | /* |
446 | * Variables for auto-shutdown. This allows "lights out" torture runs | |
447 | * to be fully scripted. | |
448 | */ | |
449 | static int shutdown_secs; /* desired test duration in seconds. */ | |
450 | static struct task_struct *shutdown_task; | |
451 | static unsigned long shutdown_time; /* jiffies to system shutdown. */ | |
452 | static void (*torture_shutdown_hook)(void); | |
453 | ||
f67a3356 PM |
454 | /* |
455 | * Absorb kthreads into a kernel function that won't return, so that | |
456 | * they won't ever access module text or data again. | |
457 | */ | |
458 | void torture_shutdown_absorb(const char *title) | |
459 | { | |
7d0ae808 | 460 | while (READ_ONCE(fullstop) == FULLSTOP_SHUTDOWN) { |
4622b487 PM |
461 | pr_notice("torture thread %s parking due to system shutdown\n", |
462 | title); | |
f67a3356 PM |
463 | schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT); |
464 | } | |
465 | } | |
466 | EXPORT_SYMBOL_GPL(torture_shutdown_absorb); | |
b5daa8f3 | 467 | |
e991dbc0 PM |
468 | /* |
469 | * Cause the torture test to shutdown the system after the test has | |
470 | * run for the time specified by the shutdown_secs parameter. | |
471 | */ | |
472 | static int torture_shutdown(void *arg) | |
473 | { | |
474 | long delta; | |
475 | unsigned long jiffies_snap; | |
476 | ||
477 | VERBOSE_TOROUT_STRING("torture_shutdown task started"); | |
478 | jiffies_snap = jiffies; | |
479 | while (ULONG_CMP_LT(jiffies_snap, shutdown_time) && | |
480 | !torture_must_stop()) { | |
481 | delta = shutdown_time - jiffies_snap; | |
482 | if (verbose) | |
483 | pr_alert("%s" TORTURE_FLAG | |
484 | "torture_shutdown task: %lu jiffies remaining\n", | |
485 | torture_type, delta); | |
486 | schedule_timeout_interruptible(delta); | |
487 | jiffies_snap = jiffies; | |
488 | } | |
489 | if (torture_must_stop()) { | |
7fafaac5 | 490 | torture_kthread_stopping("torture_shutdown"); |
e991dbc0 PM |
491 | return 0; |
492 | } | |
493 | ||
494 | /* OK, shut down the system. */ | |
495 | ||
496 | VERBOSE_TOROUT_STRING("torture_shutdown task shutting down system"); | |
497 | shutdown_task = NULL; /* Avoid self-kill deadlock. */ | |
f881825a PM |
498 | if (torture_shutdown_hook) |
499 | torture_shutdown_hook(); | |
500 | else | |
501 | VERBOSE_TOROUT_STRING("No torture_shutdown_hook(), skipping."); | |
e9fb365a | 502 | ftrace_dump(DUMP_ALL); |
e991dbc0 PM |
503 | kernel_power_off(); /* Shut down the system. */ |
504 | return 0; | |
505 | } | |
506 | ||
507 | /* | |
508 | * Start up the shutdown task. | |
509 | */ | |
510 | int torture_shutdown_init(int ssecs, void (*cleanup)(void)) | |
511 | { | |
47cf29b9 | 512 | int ret = 0; |
e991dbc0 PM |
513 | |
514 | shutdown_secs = ssecs; | |
515 | torture_shutdown_hook = cleanup; | |
516 | if (shutdown_secs > 0) { | |
517 | shutdown_time = jiffies + shutdown_secs * HZ; | |
47cf29b9 PM |
518 | ret = torture_create_kthread(torture_shutdown, NULL, |
519 | shutdown_task); | |
e991dbc0 | 520 | } |
47cf29b9 | 521 | return ret; |
e991dbc0 PM |
522 | } |
523 | EXPORT_SYMBOL_GPL(torture_shutdown_init); | |
524 | ||
4622b487 PM |
525 | /* |
526 | * Detect and respond to a system shutdown. | |
527 | */ | |
528 | static int torture_shutdown_notify(struct notifier_block *unused1, | |
529 | unsigned long unused2, void *unused3) | |
530 | { | |
531 | mutex_lock(&fullstop_mutex); | |
7d0ae808 | 532 | if (READ_ONCE(fullstop) == FULLSTOP_DONTSTOP) { |
fac480ef | 533 | VERBOSE_TOROUT_STRING("Unscheduled system shutdown detected"); |
7d0ae808 | 534 | WRITE_ONCE(fullstop, FULLSTOP_SHUTDOWN); |
fac480ef | 535 | } else { |
4622b487 | 536 | pr_warn("Concurrent rmmod and shutdown illegal!\n"); |
fac480ef | 537 | } |
4622b487 PM |
538 | mutex_unlock(&fullstop_mutex); |
539 | return NOTIFY_DONE; | |
540 | } | |
541 | ||
542 | static struct notifier_block torture_shutdown_nb = { | |
543 | .notifier_call = torture_shutdown_notify, | |
544 | }; | |
545 | ||
bfefc73a PM |
546 | /* |
547 | * Shut down the shutdown task. Say what??? Heh! This can happen if | |
548 | * the torture module gets an rmmod before the shutdown time arrives. ;-) | |
549 | */ | |
550 | static void torture_shutdown_cleanup(void) | |
551 | { | |
552 | unregister_reboot_notifier(&torture_shutdown_nb); | |
553 | if (shutdown_task != NULL) { | |
554 | VERBOSE_TOROUT_STRING("Stopping torture_shutdown task"); | |
555 | kthread_stop(shutdown_task); | |
556 | } | |
557 | shutdown_task = NULL; | |
558 | } | |
559 | ||
628edaa5 PM |
560 | /* |
561 | * Variables for stuttering, which means to periodically pause and | |
562 | * restart testing in order to catch bugs that appear when load is | |
563 | * suddenly applied to or removed from the system. | |
564 | */ | |
565 | static struct task_struct *stutter_task; | |
566 | static int stutter_pause_test; | |
567 | static int stutter; | |
568 | ||
569 | /* | |
570 | * Block until the stutter interval ends. This must be called periodically | |
571 | * by all running kthreads that need to be subject to stuttering. | |
572 | */ | |
573 | void stutter_wait(const char *title) | |
574 | { | |
3836f533 | 575 | cond_resched_rcu_qs(); |
7d0ae808 PM |
576 | while (READ_ONCE(stutter_pause_test) || |
577 | (torture_runnable && !READ_ONCE(*torture_runnable))) { | |
628edaa5 | 578 | if (stutter_pause_test) |
7d0ae808 | 579 | if (READ_ONCE(stutter_pause_test) == 1) |
ab7d4505 PM |
580 | schedule_timeout_interruptible(1); |
581 | else | |
7d0ae808 | 582 | while (READ_ONCE(stutter_pause_test)) |
ab7d4505 | 583 | cond_resched(); |
628edaa5 PM |
584 | else |
585 | schedule_timeout_interruptible(round_jiffies_relative(HZ)); | |
586 | torture_shutdown_absorb(title); | |
587 | } | |
588 | } | |
589 | EXPORT_SYMBOL_GPL(stutter_wait); | |
590 | ||
591 | /* | |
592 | * Cause the torture test to "stutter", starting and stopping all | |
593 | * threads periodically. | |
594 | */ | |
595 | static int torture_stutter(void *arg) | |
596 | { | |
597 | VERBOSE_TOROUT_STRING("torture_stutter task started"); | |
598 | do { | |
599 | if (!torture_must_stop()) { | |
ab7d4505 PM |
600 | if (stutter > 1) { |
601 | schedule_timeout_interruptible(stutter - 1); | |
7d0ae808 | 602 | WRITE_ONCE(stutter_pause_test, 2); |
ab7d4505 PM |
603 | } |
604 | schedule_timeout_interruptible(1); | |
7d0ae808 | 605 | WRITE_ONCE(stutter_pause_test, 1); |
628edaa5 PM |
606 | } |
607 | if (!torture_must_stop()) | |
608 | schedule_timeout_interruptible(stutter); | |
7d0ae808 | 609 | WRITE_ONCE(stutter_pause_test, 0); |
628edaa5 PM |
610 | torture_shutdown_absorb("torture_stutter"); |
611 | } while (!torture_must_stop()); | |
7fafaac5 | 612 | torture_kthread_stopping("torture_stutter"); |
628edaa5 PM |
613 | return 0; |
614 | } | |
615 | ||
616 | /* | |
617 | * Initialize and kick off the torture_stutter kthread. | |
618 | */ | |
619 | int torture_stutter_init(int s) | |
620 | { | |
621 | int ret; | |
622 | ||
623 | stutter = s; | |
47cf29b9 PM |
624 | ret = torture_create_kthread(torture_stutter, NULL, stutter_task); |
625 | return ret; | |
628edaa5 PM |
626 | } |
627 | EXPORT_SYMBOL_GPL(torture_stutter_init); | |
628 | ||
629 | /* | |
630 | * Cleanup after the torture_stutter kthread. | |
631 | */ | |
bfefc73a | 632 | static void torture_stutter_cleanup(void) |
628edaa5 PM |
633 | { |
634 | if (!stutter_task) | |
635 | return; | |
636 | VERBOSE_TOROUT_STRING("Stopping torture_stutter task"); | |
637 | kthread_stop(stutter_task); | |
638 | stutter_task = NULL; | |
639 | } | |
628edaa5 | 640 | |
b5daa8f3 PM |
641 | /* |
642 | * Initialize torture module. Please note that this is -not- invoked via | |
643 | * the usual module_init() mechanism, but rather by an explicit call from | |
644 | * the client torture module. This call must be paired with a later | |
645 | * torture_init_end(). | |
628edaa5 PM |
646 | * |
647 | * The runnable parameter points to a flag that controls whether or not | |
648 | * the test is currently runnable. If there is no such flag, pass in NULL. | |
b5daa8f3 | 649 | */ |
2b3f8ffe | 650 | bool torture_init_begin(char *ttype, bool v, int *runnable) |
b5daa8f3 PM |
651 | { |
652 | mutex_lock(&fullstop_mutex); | |
5228084e | 653 | if (torture_type != NULL) { |
9eb5188a | 654 | pr_alert("torture_init_begin: Refusing %s init: %s running.\n", |
5228084e | 655 | ttype, torture_type); |
9eb5188a | 656 | pr_alert("torture_init_begin: One torture test at a time!\n"); |
5228084e PM |
657 | mutex_unlock(&fullstop_mutex); |
658 | return false; | |
659 | } | |
b5daa8f3 PM |
660 | torture_type = ttype; |
661 | verbose = v; | |
628edaa5 | 662 | torture_runnable = runnable; |
36970bb9 | 663 | fullstop = FULLSTOP_DONTSTOP; |
5228084e | 664 | return true; |
b5daa8f3 PM |
665 | } |
666 | EXPORT_SYMBOL_GPL(torture_init_begin); | |
667 | ||
668 | /* | |
669 | * Tell the torture module that initialization is complete. | |
670 | */ | |
2b3f8ffe | 671 | void torture_init_end(void) |
b5daa8f3 PM |
672 | { |
673 | mutex_unlock(&fullstop_mutex); | |
4622b487 | 674 | register_reboot_notifier(&torture_shutdown_nb); |
b5daa8f3 PM |
675 | } |
676 | EXPORT_SYMBOL_GPL(torture_init_end); | |
cc47ae08 PM |
677 | |
678 | /* | |
679 | * Clean up torture module. Please note that this is -not- invoked via | |
680 | * the usual module_exit() mechanism, but rather by an explicit call from | |
681 | * the client torture module. Returns true if a race with system shutdown | |
bfefc73a PM |
682 | * is detected, otherwise, all kthreads started by functions in this file |
683 | * will be shut down. | |
cc47ae08 PM |
684 | * |
685 | * This must be called before the caller starts shutting down its own | |
686 | * kthreads. | |
d36a7a0d DB |
687 | * |
688 | * Both torture_cleanup_begin() and torture_cleanup_end() must be paired, | |
689 | * in order to correctly perform the cleanup. They are separated because | |
690 | * threads can still need to reference the torture_type type, thus nullify | |
691 | * only after completing all other relevant calls. | |
cc47ae08 | 692 | */ |
d36a7a0d | 693 | bool torture_cleanup_begin(void) |
cc47ae08 PM |
694 | { |
695 | mutex_lock(&fullstop_mutex); | |
7d0ae808 | 696 | if (READ_ONCE(fullstop) == FULLSTOP_SHUTDOWN) { |
cc47ae08 PM |
697 | pr_warn("Concurrent rmmod and shutdown illegal!\n"); |
698 | mutex_unlock(&fullstop_mutex); | |
699 | schedule_timeout_uninterruptible(10); | |
700 | return true; | |
701 | } | |
7d0ae808 | 702 | WRITE_ONCE(fullstop, FULLSTOP_RMMOD); |
cc47ae08 | 703 | mutex_unlock(&fullstop_mutex); |
bfefc73a | 704 | torture_shutdown_cleanup(); |
cc47ae08 | 705 | torture_shuffle_cleanup(); |
bfefc73a | 706 | torture_stutter_cleanup(); |
cc47ae08 | 707 | torture_onoff_cleanup(); |
d36a7a0d DB |
708 | return false; |
709 | } | |
710 | EXPORT_SYMBOL_GPL(torture_cleanup_begin); | |
711 | ||
712 | void torture_cleanup_end(void) | |
713 | { | |
5228084e PM |
714 | mutex_lock(&fullstop_mutex); |
715 | torture_type = NULL; | |
716 | mutex_unlock(&fullstop_mutex); | |
cc47ae08 | 717 | } |
d36a7a0d | 718 | EXPORT_SYMBOL_GPL(torture_cleanup_end); |
36970bb9 PM |
719 | |
720 | /* | |
721 | * Is it time for the current torture test to stop? | |
722 | */ | |
723 | bool torture_must_stop(void) | |
724 | { | |
725 | return torture_must_stop_irq() || kthread_should_stop(); | |
726 | } | |
727 | EXPORT_SYMBOL_GPL(torture_must_stop); | |
728 | ||
729 | /* | |
730 | * Is it time for the current torture test to stop? This is the irq-safe | |
731 | * version, hence no check for kthread_should_stop(). | |
732 | */ | |
733 | bool torture_must_stop_irq(void) | |
734 | { | |
7d0ae808 | 735 | return READ_ONCE(fullstop) != FULLSTOP_DONTSTOP; |
36970bb9 PM |
736 | } |
737 | EXPORT_SYMBOL_GPL(torture_must_stop_irq); | |
7fafaac5 PM |
738 | |
739 | /* | |
740 | * Each kthread must wait for kthread_should_stop() before returning from | |
741 | * its top-level function, otherwise segfaults ensue. This function | |
742 | * prints a "stopping" message and waits for kthread_should_stop(), and | |
743 | * should be called from all torture kthreads immediately prior to | |
744 | * returning. | |
745 | */ | |
746 | void torture_kthread_stopping(char *title) | |
747 | { | |
0d6821d5 PM |
748 | char buf[128]; |
749 | ||
750 | snprintf(buf, sizeof(buf), "Stopping %s", title); | |
751 | VERBOSE_TOROUT_STRING(buf); | |
7fafaac5 PM |
752 | while (!kthread_should_stop()) { |
753 | torture_shutdown_absorb(title); | |
754 | schedule_timeout_uninterruptible(1); | |
755 | } | |
756 | } | |
757 | EXPORT_SYMBOL_GPL(torture_kthread_stopping); | |
47cf29b9 PM |
758 | |
759 | /* | |
760 | * Create a generic torture kthread that is immediately runnable. If you | |
761 | * need the kthread to be stopped so that you can do something to it before | |
762 | * it starts, you will need to open-code your own. | |
763 | */ | |
764 | int _torture_create_kthread(int (*fn)(void *arg), void *arg, char *s, char *m, | |
765 | char *f, struct task_struct **tp) | |
766 | { | |
767 | int ret = 0; | |
768 | ||
769 | VERBOSE_TOROUT_STRING(m); | |
6945915e | 770 | *tp = kthread_run(fn, arg, "%s", s); |
47cf29b9 PM |
771 | if (IS_ERR(*tp)) { |
772 | ret = PTR_ERR(*tp); | |
773 | VERBOSE_TOROUT_ERRSTRING(f); | |
774 | *tp = NULL; | |
775 | } | |
776 | torture_shuffle_task_register(*tp); | |
777 | return ret; | |
778 | } | |
779 | EXPORT_SYMBOL_GPL(_torture_create_kthread); | |
9c029b86 PM |
780 | |
781 | /* | |
782 | * Stop a generic kthread, emitting a message. | |
783 | */ | |
784 | void _torture_stop_kthread(char *m, struct task_struct **tp) | |
785 | { | |
786 | if (*tp == NULL) | |
787 | return; | |
788 | VERBOSE_TOROUT_STRING(m); | |
789 | kthread_stop(*tp); | |
790 | *tp = NULL; | |
791 | } | |
792 | EXPORT_SYMBOL_GPL(_torture_stop_kthread); |