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8f8e76c0 | 1 | // SPDX-License-Identifier: GPL-2.0+ |
51b1130e PM |
2 | /* |
3 | * Common functions for in-kernel torture tests. | |
4 | * | |
51b1130e PM |
5 | * Copyright (C) IBM Corporation, 2014 |
6 | * | |
8f8e76c0 | 7 | * Author: Paul E. McKenney <paulmck@linux.ibm.com> |
51b1130e PM |
8 | * Based on kernel/rcu/torture.c. |
9 | */ | |
60500037 PM |
10 | |
11 | #define pr_fmt(fmt) fmt | |
12 | ||
51b1130e PM |
13 | #include <linux/types.h> |
14 | #include <linux/kernel.h> | |
15 | #include <linux/init.h> | |
16 | #include <linux/module.h> | |
17 | #include <linux/kthread.h> | |
18 | #include <linux/err.h> | |
19 | #include <linux/spinlock.h> | |
20 | #include <linux/smp.h> | |
21 | #include <linux/interrupt.h> | |
22 | #include <linux/sched.h> | |
e6017571 | 23 | #include <linux/sched/clock.h> |
51b1130e PM |
24 | #include <linux/atomic.h> |
25 | #include <linux/bitops.h> | |
26 | #include <linux/completion.h> | |
27 | #include <linux/moduleparam.h> | |
28 | #include <linux/percpu.h> | |
29 | #include <linux/notifier.h> | |
30 | #include <linux/reboot.h> | |
31 | #include <linux/freezer.h> | |
32 | #include <linux/cpu.h> | |
33 | #include <linux/delay.h> | |
34 | #include <linux/stat.h> | |
35 | #include <linux/slab.h> | |
36 | #include <linux/trace_clock.h> | |
31257c3c | 37 | #include <linux/ktime.h> |
51b1130e PM |
38 | #include <asm/byteorder.h> |
39 | #include <linux/torture.h> | |
dac95906 | 40 | #include "rcu/rcu.h" |
51b1130e PM |
41 | |
42 | MODULE_LICENSE("GPL"); | |
8f8e76c0 | 43 | MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com>"); |
51b1130e | 44 | |
b5daa8f3 | 45 | static char *torture_type; |
90127d60 | 46 | static int verbose; |
b5daa8f3 | 47 | |
36970bb9 PM |
48 | /* Mediate rmmod and system shutdown. Concurrent rmmod & shutdown illegal! */ |
49 | #define FULLSTOP_DONTSTOP 0 /* Normal operation. */ | |
50 | #define FULLSTOP_SHUTDOWN 1 /* System shutdown with torture running. */ | |
51 | #define FULLSTOP_RMMOD 2 /* Normal rmmod of torture. */ | |
52 | static int fullstop = FULLSTOP_RMMOD; | |
4622b487 | 53 | static DEFINE_MUTEX(fullstop_mutex); |
f67a3356 | 54 | |
2e9e8081 PM |
55 | #ifdef CONFIG_HOTPLUG_CPU |
56 | ||
57 | /* | |
58 | * Variables for online-offline handling. Only present if CPU hotplug | |
59 | * is enabled, otherwise does nothing. | |
60 | */ | |
61 | ||
62 | static struct task_struct *onoff_task; | |
63 | static long onoff_holdoff; | |
64 | static long onoff_interval; | |
3a6cb58f | 65 | static torture_ofl_func *onoff_f; |
2e9e8081 PM |
66 | static long n_offline_attempts; |
67 | static long n_offline_successes; | |
68 | static unsigned long sum_offline; | |
69 | static int min_offline = -1; | |
70 | static int max_offline; | |
71 | static long n_online_attempts; | |
72 | static long n_online_successes; | |
73 | static unsigned long sum_online; | |
74 | static int min_online = -1; | |
75 | static int max_online; | |
76 | ||
d95f5ba9 PM |
77 | /* |
78 | * Attempt to take a CPU offline. Return false if the CPU is already | |
79 | * offline or if it is not subject to CPU-hotplug operations. The | |
80 | * caller can detect other failures by looking at the statistics. | |
81 | */ | |
82 | bool torture_offline(int cpu, long *n_offl_attempts, long *n_offl_successes, | |
83 | unsigned long *sum_offl, int *min_offl, int *max_offl) | |
84 | { | |
85 | unsigned long delta; | |
86 | int ret; | |
87 | unsigned long starttime; | |
88 | ||
89 | if (!cpu_online(cpu) || !cpu_is_hotpluggable(cpu)) | |
90 | return false; | |
91 | ||
90127d60 | 92 | if (verbose > 1) |
d95f5ba9 PM |
93 | pr_alert("%s" TORTURE_FLAG |
94 | "torture_onoff task: offlining %d\n", | |
95 | torture_type, cpu); | |
96 | starttime = jiffies; | |
97 | (*n_offl_attempts)++; | |
98 | ret = cpu_down(cpu); | |
99 | if (ret) { | |
100 | if (verbose) | |
101 | pr_alert("%s" TORTURE_FLAG | |
102 | "torture_onoff task: offline %d failed: errno %d\n", | |
103 | torture_type, cpu, ret); | |
104 | } else { | |
90127d60 | 105 | if (verbose > 1) |
d95f5ba9 PM |
106 | pr_alert("%s" TORTURE_FLAG |
107 | "torture_onoff task: offlined %d\n", | |
108 | torture_type, cpu); | |
3a6cb58f PM |
109 | if (onoff_f) |
110 | onoff_f(); | |
d95f5ba9 PM |
111 | (*n_offl_successes)++; |
112 | delta = jiffies - starttime; | |
a2b2df20 | 113 | *sum_offl += delta; |
d95f5ba9 PM |
114 | if (*min_offl < 0) { |
115 | *min_offl = delta; | |
116 | *max_offl = delta; | |
117 | } | |
118 | if (*min_offl > delta) | |
119 | *min_offl = delta; | |
120 | if (*max_offl < delta) | |
121 | *max_offl = delta; | |
122 | } | |
123 | ||
124 | return true; | |
125 | } | |
126 | EXPORT_SYMBOL_GPL(torture_offline); | |
127 | ||
128 | /* | |
129 | * Attempt to bring a CPU online. Return false if the CPU is already | |
130 | * online or if it is not subject to CPU-hotplug operations. The | |
131 | * caller can detect other failures by looking at the statistics. | |
132 | */ | |
133 | bool torture_online(int cpu, long *n_onl_attempts, long *n_onl_successes, | |
134 | unsigned long *sum_onl, int *min_onl, int *max_onl) | |
135 | { | |
136 | unsigned long delta; | |
137 | int ret; | |
138 | unsigned long starttime; | |
139 | ||
140 | if (cpu_online(cpu) || !cpu_is_hotpluggable(cpu)) | |
141 | return false; | |
142 | ||
90127d60 | 143 | if (verbose > 1) |
d95f5ba9 PM |
144 | pr_alert("%s" TORTURE_FLAG |
145 | "torture_onoff task: onlining %d\n", | |
146 | torture_type, cpu); | |
147 | starttime = jiffies; | |
148 | (*n_onl_attempts)++; | |
149 | ret = cpu_up(cpu); | |
150 | if (ret) { | |
151 | if (verbose) | |
152 | pr_alert("%s" TORTURE_FLAG | |
153 | "torture_onoff task: online %d failed: errno %d\n", | |
154 | torture_type, cpu, ret); | |
155 | } else { | |
90127d60 | 156 | if (verbose > 1) |
d95f5ba9 PM |
157 | pr_alert("%s" TORTURE_FLAG |
158 | "torture_onoff task: onlined %d\n", | |
159 | torture_type, cpu); | |
160 | (*n_onl_successes)++; | |
161 | delta = jiffies - starttime; | |
162 | *sum_onl += delta; | |
163 | if (*min_onl < 0) { | |
164 | *min_onl = delta; | |
165 | *max_onl = delta; | |
166 | } | |
167 | if (*min_onl > delta) | |
168 | *min_onl = delta; | |
169 | if (*max_onl < delta) | |
170 | *max_onl = delta; | |
171 | } | |
172 | ||
173 | return true; | |
174 | } | |
175 | EXPORT_SYMBOL_GPL(torture_online); | |
176 | ||
2e9e8081 PM |
177 | /* |
178 | * Execute random CPU-hotplug operations at the interval specified | |
179 | * by the onoff_interval. | |
180 | */ | |
181 | static int | |
182 | torture_onoff(void *arg) | |
183 | { | |
184 | int cpu; | |
2e9e8081 PM |
185 | int maxcpu = -1; |
186 | DEFINE_TORTURE_RANDOM(rand); | |
28cf5952 | 187 | int ret; |
2e9e8081 PM |
188 | |
189 | VERBOSE_TOROUT_STRING("torture_onoff task started"); | |
190 | for_each_online_cpu(cpu) | |
191 | maxcpu = cpu; | |
192 | WARN_ON(maxcpu < 0); | |
28cf5952 PM |
193 | if (!IS_MODULE(CONFIG_TORTURE_TEST)) |
194 | for_each_possible_cpu(cpu) { | |
195 | if (cpu_online(cpu)) | |
196 | continue; | |
197 | ret = cpu_up(cpu); | |
198 | if (ret && verbose) { | |
199 | pr_alert("%s" TORTURE_FLAG | |
200 | "%s: Initial online %d: errno %d\n", | |
201 | __func__, torture_type, cpu, ret); | |
202 | } | |
203 | } | |
750db0f5 BF |
204 | |
205 | if (maxcpu == 0) { | |
206 | VERBOSE_TOROUT_STRING("Only one CPU, so CPU-hotplug testing is disabled"); | |
207 | goto stop; | |
208 | } | |
209 | ||
2e9e8081 PM |
210 | if (onoff_holdoff > 0) { |
211 | VERBOSE_TOROUT_STRING("torture_onoff begin holdoff"); | |
212 | schedule_timeout_interruptible(onoff_holdoff); | |
213 | VERBOSE_TOROUT_STRING("torture_onoff end holdoff"); | |
214 | } | |
215 | while (!torture_must_stop()) { | |
216 | cpu = (torture_random(&rand) >> 4) % (maxcpu + 1); | |
d95f5ba9 PM |
217 | if (!torture_offline(cpu, |
218 | &n_offline_attempts, &n_offline_successes, | |
219 | &sum_offline, &min_offline, &max_offline)) | |
220 | torture_online(cpu, | |
221 | &n_online_attempts, &n_online_successes, | |
222 | &sum_online, &min_online, &max_online); | |
2e9e8081 PM |
223 | schedule_timeout_interruptible(onoff_interval); |
224 | } | |
750db0f5 BF |
225 | |
226 | stop: | |
7fafaac5 | 227 | torture_kthread_stopping("torture_onoff"); |
2e9e8081 PM |
228 | return 0; |
229 | } | |
230 | ||
231 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ | |
232 | ||
233 | /* | |
234 | * Initiate online-offline handling. | |
235 | */ | |
3a6cb58f | 236 | int torture_onoff_init(long ooholdoff, long oointerval, torture_ofl_func *f) |
2e9e8081 | 237 | { |
47cf29b9 | 238 | #ifdef CONFIG_HOTPLUG_CPU |
2e9e8081 PM |
239 | onoff_holdoff = ooholdoff; |
240 | onoff_interval = oointerval; | |
3a6cb58f | 241 | onoff_f = f; |
2e9e8081 PM |
242 | if (onoff_interval <= 0) |
243 | return 0; | |
2a7d9688 PG |
244 | return torture_create_kthread(torture_onoff, NULL, onoff_task); |
245 | #else /* #ifdef CONFIG_HOTPLUG_CPU */ | |
246 | return 0; | |
247 | #endif /* #else #ifdef CONFIG_HOTPLUG_CPU */ | |
2e9e8081 PM |
248 | } |
249 | EXPORT_SYMBOL_GPL(torture_onoff_init); | |
250 | ||
251 | /* | |
252 | * Clean up after online/offline testing. | |
253 | */ | |
cc47ae08 | 254 | static void torture_onoff_cleanup(void) |
2e9e8081 PM |
255 | { |
256 | #ifdef CONFIG_HOTPLUG_CPU | |
257 | if (onoff_task == NULL) | |
258 | return; | |
259 | VERBOSE_TOROUT_STRING("Stopping torture_onoff task"); | |
260 | kthread_stop(onoff_task); | |
261 | onoff_task = NULL; | |
262 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ | |
263 | } | |
264 | EXPORT_SYMBOL_GPL(torture_onoff_cleanup); | |
265 | ||
266 | /* | |
267 | * Print online/offline testing statistics. | |
268 | */ | |
eea203fe | 269 | void torture_onoff_stats(void) |
2e9e8081 PM |
270 | { |
271 | #ifdef CONFIG_HOTPLUG_CPU | |
eea203fe JP |
272 | pr_cont("onoff: %ld/%ld:%ld/%ld %d,%d:%d,%d %lu:%lu (HZ=%d) ", |
273 | n_online_successes, n_online_attempts, | |
274 | n_offline_successes, n_offline_attempts, | |
275 | min_online, max_online, | |
276 | min_offline, max_offline, | |
277 | sum_online, sum_offline, HZ); | |
2e9e8081 | 278 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ |
2e9e8081 PM |
279 | } |
280 | EXPORT_SYMBOL_GPL(torture_onoff_stats); | |
281 | ||
282 | /* | |
283 | * Were all the online/offline operations successful? | |
284 | */ | |
285 | bool torture_onoff_failures(void) | |
286 | { | |
287 | #ifdef CONFIG_HOTPLUG_CPU | |
288 | return n_online_successes != n_online_attempts || | |
289 | n_offline_successes != n_offline_attempts; | |
290 | #else /* #ifdef CONFIG_HOTPLUG_CPU */ | |
291 | return false; | |
292 | #endif /* #else #ifdef CONFIG_HOTPLUG_CPU */ | |
293 | } | |
294 | EXPORT_SYMBOL_GPL(torture_onoff_failures); | |
295 | ||
51b1130e PM |
296 | #define TORTURE_RANDOM_MULT 39916801 /* prime */ |
297 | #define TORTURE_RANDOM_ADD 479001701 /* prime */ | |
298 | #define TORTURE_RANDOM_REFRESH 10000 | |
299 | ||
300 | /* | |
301 | * Crude but fast random-number generator. Uses a linear congruential | |
302 | * generator, with occasional help from cpu_clock(). | |
303 | */ | |
304 | unsigned long | |
305 | torture_random(struct torture_random_state *trsp) | |
306 | { | |
307 | if (--trsp->trs_count < 0) { | |
308 | trsp->trs_state += (unsigned long)local_clock(); | |
309 | trsp->trs_count = TORTURE_RANDOM_REFRESH; | |
310 | } | |
311 | trsp->trs_state = trsp->trs_state * TORTURE_RANDOM_MULT + | |
312 | TORTURE_RANDOM_ADD; | |
313 | return swahw32(trsp->trs_state); | |
314 | } | |
315 | EXPORT_SYMBOL_GPL(torture_random); | |
f67a3356 | 316 | |
3808dc9f PM |
317 | /* |
318 | * Variables for shuffling. The idea is to ensure that each CPU stays | |
319 | * idle for an extended period to test interactions with dyntick idle, | |
b564d62e | 320 | * as well as interactions with any per-CPU variables. |
3808dc9f PM |
321 | */ |
322 | struct shuffle_task { | |
323 | struct list_head st_l; | |
324 | struct task_struct *st_t; | |
325 | }; | |
326 | ||
327 | static long shuffle_interval; /* In jiffies. */ | |
328 | static struct task_struct *shuffler_task; | |
329 | static cpumask_var_t shuffle_tmp_mask; | |
330 | static int shuffle_idle_cpu; /* Force all torture tasks off this CPU */ | |
331 | static struct list_head shuffle_task_list = LIST_HEAD_INIT(shuffle_task_list); | |
332 | static DEFINE_MUTEX(shuffle_task_mutex); | |
333 | ||
334 | /* | |
335 | * Register a task to be shuffled. If there is no memory, just splat | |
336 | * and don't bother registering. | |
337 | */ | |
338 | void torture_shuffle_task_register(struct task_struct *tp) | |
339 | { | |
340 | struct shuffle_task *stp; | |
341 | ||
342 | if (WARN_ON_ONCE(tp == NULL)) | |
343 | return; | |
344 | stp = kmalloc(sizeof(*stp), GFP_KERNEL); | |
345 | if (WARN_ON_ONCE(stp == NULL)) | |
346 | return; | |
347 | stp->st_t = tp; | |
348 | mutex_lock(&shuffle_task_mutex); | |
349 | list_add(&stp->st_l, &shuffle_task_list); | |
350 | mutex_unlock(&shuffle_task_mutex); | |
351 | } | |
352 | EXPORT_SYMBOL_GPL(torture_shuffle_task_register); | |
353 | ||
354 | /* | |
355 | * Unregister all tasks, for example, at the end of the torture run. | |
356 | */ | |
357 | static void torture_shuffle_task_unregister_all(void) | |
358 | { | |
359 | struct shuffle_task *stp; | |
360 | struct shuffle_task *p; | |
361 | ||
362 | mutex_lock(&shuffle_task_mutex); | |
363 | list_for_each_entry_safe(stp, p, &shuffle_task_list, st_l) { | |
364 | list_del(&stp->st_l); | |
365 | kfree(stp); | |
366 | } | |
367 | mutex_unlock(&shuffle_task_mutex); | |
368 | } | |
369 | ||
370 | /* Shuffle tasks such that we allow shuffle_idle_cpu to become idle. | |
371 | * A special case is when shuffle_idle_cpu = -1, in which case we allow | |
372 | * the tasks to run on all CPUs. | |
373 | */ | |
374 | static void torture_shuffle_tasks(void) | |
375 | { | |
376 | struct shuffle_task *stp; | |
377 | ||
378 | cpumask_setall(shuffle_tmp_mask); | |
379 | get_online_cpus(); | |
380 | ||
381 | /* No point in shuffling if there is only one online CPU (ex: UP) */ | |
382 | if (num_online_cpus() == 1) { | |
383 | put_online_cpus(); | |
384 | return; | |
385 | } | |
386 | ||
387 | /* Advance to the next CPU. Upon overflow, don't idle any CPUs. */ | |
388 | shuffle_idle_cpu = cpumask_next(shuffle_idle_cpu, shuffle_tmp_mask); | |
389 | if (shuffle_idle_cpu >= nr_cpu_ids) | |
390 | shuffle_idle_cpu = -1; | |
5ed63b19 | 391 | else |
3808dc9f | 392 | cpumask_clear_cpu(shuffle_idle_cpu, shuffle_tmp_mask); |
3808dc9f PM |
393 | |
394 | mutex_lock(&shuffle_task_mutex); | |
395 | list_for_each_entry(stp, &shuffle_task_list, st_l) | |
396 | set_cpus_allowed_ptr(stp->st_t, shuffle_tmp_mask); | |
397 | mutex_unlock(&shuffle_task_mutex); | |
398 | ||
399 | put_online_cpus(); | |
400 | } | |
401 | ||
402 | /* Shuffle tasks across CPUs, with the intent of allowing each CPU in the | |
403 | * system to become idle at a time and cut off its timer ticks. This is meant | |
404 | * to test the support for such tickless idle CPU in RCU. | |
405 | */ | |
406 | static int torture_shuffle(void *arg) | |
407 | { | |
408 | VERBOSE_TOROUT_STRING("torture_shuffle task started"); | |
409 | do { | |
410 | schedule_timeout_interruptible(shuffle_interval); | |
411 | torture_shuffle_tasks(); | |
412 | torture_shutdown_absorb("torture_shuffle"); | |
413 | } while (!torture_must_stop()); | |
7fafaac5 | 414 | torture_kthread_stopping("torture_shuffle"); |
3808dc9f PM |
415 | return 0; |
416 | } | |
417 | ||
418 | /* | |
419 | * Start the shuffler, with shuffint in jiffies. | |
420 | */ | |
421 | int torture_shuffle_init(long shuffint) | |
422 | { | |
3808dc9f PM |
423 | shuffle_interval = shuffint; |
424 | ||
425 | shuffle_idle_cpu = -1; | |
426 | ||
427 | if (!alloc_cpumask_var(&shuffle_tmp_mask, GFP_KERNEL)) { | |
428 | VERBOSE_TOROUT_ERRSTRING("Failed to alloc mask"); | |
429 | return -ENOMEM; | |
430 | } | |
431 | ||
432 | /* Create the shuffler thread */ | |
47cf29b9 | 433 | return torture_create_kthread(torture_shuffle, NULL, shuffler_task); |
3808dc9f PM |
434 | } |
435 | EXPORT_SYMBOL_GPL(torture_shuffle_init); | |
436 | ||
437 | /* | |
438 | * Stop the shuffling. | |
439 | */ | |
cc47ae08 | 440 | static void torture_shuffle_cleanup(void) |
3808dc9f PM |
441 | { |
442 | torture_shuffle_task_unregister_all(); | |
443 | if (shuffler_task) { | |
444 | VERBOSE_TOROUT_STRING("Stopping torture_shuffle task"); | |
445 | kthread_stop(shuffler_task); | |
446 | free_cpumask_var(shuffle_tmp_mask); | |
447 | } | |
448 | shuffler_task = NULL; | |
449 | } | |
450 | EXPORT_SYMBOL_GPL(torture_shuffle_cleanup); | |
451 | ||
e991dbc0 PM |
452 | /* |
453 | * Variables for auto-shutdown. This allows "lights out" torture runs | |
454 | * to be fully scripted. | |
455 | */ | |
e991dbc0 | 456 | static struct task_struct *shutdown_task; |
31257c3c | 457 | static ktime_t shutdown_time; /* time to system shutdown. */ |
e991dbc0 PM |
458 | static void (*torture_shutdown_hook)(void); |
459 | ||
f67a3356 PM |
460 | /* |
461 | * Absorb kthreads into a kernel function that won't return, so that | |
462 | * they won't ever access module text or data again. | |
463 | */ | |
464 | void torture_shutdown_absorb(const char *title) | |
465 | { | |
7d0ae808 | 466 | while (READ_ONCE(fullstop) == FULLSTOP_SHUTDOWN) { |
4622b487 PM |
467 | pr_notice("torture thread %s parking due to system shutdown\n", |
468 | title); | |
f67a3356 PM |
469 | schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT); |
470 | } | |
471 | } | |
472 | EXPORT_SYMBOL_GPL(torture_shutdown_absorb); | |
b5daa8f3 | 473 | |
e991dbc0 PM |
474 | /* |
475 | * Cause the torture test to shutdown the system after the test has | |
476 | * run for the time specified by the shutdown_secs parameter. | |
477 | */ | |
478 | static int torture_shutdown(void *arg) | |
479 | { | |
31257c3c | 480 | ktime_t ktime_snap; |
e991dbc0 PM |
481 | |
482 | VERBOSE_TOROUT_STRING("torture_shutdown task started"); | |
31257c3c PM |
483 | ktime_snap = ktime_get(); |
484 | while (ktime_before(ktime_snap, shutdown_time) && | |
e991dbc0 | 485 | !torture_must_stop()) { |
e991dbc0 PM |
486 | if (verbose) |
487 | pr_alert("%s" TORTURE_FLAG | |
31257c3c PM |
488 | "torture_shutdown task: %llu ms remaining\n", |
489 | torture_type, | |
490 | ktime_ms_delta(shutdown_time, ktime_snap)); | |
491 | set_current_state(TASK_INTERRUPTIBLE); | |
492 | schedule_hrtimeout(&shutdown_time, HRTIMER_MODE_ABS); | |
493 | ktime_snap = ktime_get(); | |
e991dbc0 PM |
494 | } |
495 | if (torture_must_stop()) { | |
7fafaac5 | 496 | torture_kthread_stopping("torture_shutdown"); |
e991dbc0 PM |
497 | return 0; |
498 | } | |
499 | ||
500 | /* OK, shut down the system. */ | |
501 | ||
502 | VERBOSE_TOROUT_STRING("torture_shutdown task shutting down system"); | |
503 | shutdown_task = NULL; /* Avoid self-kill deadlock. */ | |
f881825a PM |
504 | if (torture_shutdown_hook) |
505 | torture_shutdown_hook(); | |
506 | else | |
507 | VERBOSE_TOROUT_STRING("No torture_shutdown_hook(), skipping."); | |
dac95906 | 508 | rcu_ftrace_dump(DUMP_ALL); |
e991dbc0 PM |
509 | kernel_power_off(); /* Shut down the system. */ |
510 | return 0; | |
511 | } | |
512 | ||
513 | /* | |
514 | * Start up the shutdown task. | |
515 | */ | |
516 | int torture_shutdown_init(int ssecs, void (*cleanup)(void)) | |
517 | { | |
e991dbc0 | 518 | torture_shutdown_hook = cleanup; |
31257c3c PM |
519 | if (ssecs > 0) { |
520 | shutdown_time = ktime_add(ktime_get(), ktime_set(ssecs, 0)); | |
2a7d9688 | 521 | return torture_create_kthread(torture_shutdown, NULL, |
47cf29b9 | 522 | shutdown_task); |
e991dbc0 | 523 | } |
2a7d9688 | 524 | return 0; |
e991dbc0 PM |
525 | } |
526 | EXPORT_SYMBOL_GPL(torture_shutdown_init); | |
527 | ||
4622b487 PM |
528 | /* |
529 | * Detect and respond to a system shutdown. | |
530 | */ | |
531 | static int torture_shutdown_notify(struct notifier_block *unused1, | |
532 | unsigned long unused2, void *unused3) | |
533 | { | |
534 | mutex_lock(&fullstop_mutex); | |
7d0ae808 | 535 | if (READ_ONCE(fullstop) == FULLSTOP_DONTSTOP) { |
fac480ef | 536 | VERBOSE_TOROUT_STRING("Unscheduled system shutdown detected"); |
7d0ae808 | 537 | WRITE_ONCE(fullstop, FULLSTOP_SHUTDOWN); |
fac480ef | 538 | } else { |
4622b487 | 539 | pr_warn("Concurrent rmmod and shutdown illegal!\n"); |
fac480ef | 540 | } |
4622b487 PM |
541 | mutex_unlock(&fullstop_mutex); |
542 | return NOTIFY_DONE; | |
543 | } | |
544 | ||
545 | static struct notifier_block torture_shutdown_nb = { | |
546 | .notifier_call = torture_shutdown_notify, | |
547 | }; | |
548 | ||
bfefc73a PM |
549 | /* |
550 | * Shut down the shutdown task. Say what??? Heh! This can happen if | |
551 | * the torture module gets an rmmod before the shutdown time arrives. ;-) | |
552 | */ | |
553 | static void torture_shutdown_cleanup(void) | |
554 | { | |
555 | unregister_reboot_notifier(&torture_shutdown_nb); | |
556 | if (shutdown_task != NULL) { | |
557 | VERBOSE_TOROUT_STRING("Stopping torture_shutdown task"); | |
558 | kthread_stop(shutdown_task); | |
559 | } | |
560 | shutdown_task = NULL; | |
561 | } | |
562 | ||
628edaa5 PM |
563 | /* |
564 | * Variables for stuttering, which means to periodically pause and | |
565 | * restart testing in order to catch bugs that appear when load is | |
566 | * suddenly applied to or removed from the system. | |
567 | */ | |
568 | static struct task_struct *stutter_task; | |
569 | static int stutter_pause_test; | |
570 | static int stutter; | |
571 | ||
572 | /* | |
573 | * Block until the stutter interval ends. This must be called periodically | |
574 | * by all running kthreads that need to be subject to stuttering. | |
575 | */ | |
474e59b4 | 576 | bool stutter_wait(const char *title) |
628edaa5 | 577 | { |
4ced3314 PM |
578 | int spt; |
579 | ||
cee43939 | 580 | cond_resched_tasks_rcu_qs(); |
4ced3314 | 581 | spt = READ_ONCE(stutter_pause_test); |
29d39390 | 582 | for (; spt; spt = READ_ONCE(stutter_pause_test)) { |
4ced3314 PM |
583 | if (spt == 1) { |
584 | schedule_timeout_interruptible(1); | |
585 | } else if (spt == 2) { | |
586 | while (READ_ONCE(stutter_pause_test)) | |
587 | cond_resched(); | |
588 | } else { | |
628edaa5 | 589 | schedule_timeout_interruptible(round_jiffies_relative(HZ)); |
4ced3314 | 590 | } |
628edaa5 PM |
591 | torture_shutdown_absorb(title); |
592 | } | |
474e59b4 | 593 | return !!spt; |
628edaa5 PM |
594 | } |
595 | EXPORT_SYMBOL_GPL(stutter_wait); | |
596 | ||
597 | /* | |
598 | * Cause the torture test to "stutter", starting and stopping all | |
599 | * threads periodically. | |
600 | */ | |
601 | static int torture_stutter(void *arg) | |
602 | { | |
603 | VERBOSE_TOROUT_STRING("torture_stutter task started"); | |
604 | do { | |
4ced3314 | 605 | if (!torture_must_stop() && stutter > 1) { |
7d0ae808 | 606 | WRITE_ONCE(stutter_pause_test, 1); |
4ced3314 PM |
607 | schedule_timeout_interruptible(stutter - 1); |
608 | WRITE_ONCE(stutter_pause_test, 2); | |
609 | schedule_timeout_interruptible(1); | |
628edaa5 | 610 | } |
4ced3314 | 611 | WRITE_ONCE(stutter_pause_test, 0); |
628edaa5 PM |
612 | if (!torture_must_stop()) |
613 | schedule_timeout_interruptible(stutter); | |
628edaa5 PM |
614 | torture_shutdown_absorb("torture_stutter"); |
615 | } while (!torture_must_stop()); | |
7fafaac5 | 616 | torture_kthread_stopping("torture_stutter"); |
628edaa5 PM |
617 | return 0; |
618 | } | |
619 | ||
620 | /* | |
621 | * Initialize and kick off the torture_stutter kthread. | |
622 | */ | |
2a7d9688 | 623 | int torture_stutter_init(const int s) |
628edaa5 | 624 | { |
628edaa5 | 625 | stutter = s; |
2a7d9688 | 626 | return torture_create_kthread(torture_stutter, NULL, stutter_task); |
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 | */ |
90127d60 | 651 | bool torture_init_begin(char *ttype, int v) |
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; | |
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); |