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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 | |
8171d3e0 PM |
45 | static bool disable_onoff_at_boot; |
46 | module_param(disable_onoff_at_boot, bool, 0444); | |
47 | ||
2102ad29 PM |
48 | static bool ftrace_dump_at_shutdown; |
49 | module_param(ftrace_dump_at_shutdown, bool, 0444); | |
50 | ||
b5daa8f3 | 51 | static char *torture_type; |
90127d60 | 52 | static int verbose; |
b5daa8f3 | 53 | |
36970bb9 PM |
54 | /* Mediate rmmod and system shutdown. Concurrent rmmod & shutdown illegal! */ |
55 | #define FULLSTOP_DONTSTOP 0 /* Normal operation. */ | |
56 | #define FULLSTOP_SHUTDOWN 1 /* System shutdown with torture running. */ | |
57 | #define FULLSTOP_RMMOD 2 /* Normal rmmod of torture. */ | |
58 | static int fullstop = FULLSTOP_RMMOD; | |
4622b487 | 59 | static DEFINE_MUTEX(fullstop_mutex); |
f67a3356 | 60 | |
2e9e8081 PM |
61 | #ifdef CONFIG_HOTPLUG_CPU |
62 | ||
63 | /* | |
64 | * Variables for online-offline handling. Only present if CPU hotplug | |
65 | * is enabled, otherwise does nothing. | |
66 | */ | |
67 | ||
68 | static struct task_struct *onoff_task; | |
69 | static long onoff_holdoff; | |
70 | static long onoff_interval; | |
3a6cb58f | 71 | static torture_ofl_func *onoff_f; |
2e9e8081 PM |
72 | static long n_offline_attempts; |
73 | static long n_offline_successes; | |
74 | static unsigned long sum_offline; | |
75 | static int min_offline = -1; | |
76 | static int max_offline; | |
77 | static long n_online_attempts; | |
78 | static long n_online_successes; | |
79 | static unsigned long sum_online; | |
80 | static int min_online = -1; | |
81 | static int max_online; | |
82 | ||
d95f5ba9 PM |
83 | /* |
84 | * Attempt to take a CPU offline. Return false if the CPU is already | |
85 | * offline or if it is not subject to CPU-hotplug operations. The | |
86 | * caller can detect other failures by looking at the statistics. | |
87 | */ | |
88 | bool torture_offline(int cpu, long *n_offl_attempts, long *n_offl_successes, | |
89 | unsigned long *sum_offl, int *min_offl, int *max_offl) | |
90 | { | |
91 | unsigned long delta; | |
92 | int ret; | |
a59ee765 | 93 | char *s; |
d95f5ba9 PM |
94 | unsigned long starttime; |
95 | ||
96 | if (!cpu_online(cpu) || !cpu_is_hotpluggable(cpu)) | |
97 | return false; | |
24aca4ae PM |
98 | if (num_online_cpus() <= 1) |
99 | return false; /* Can't offline the last CPU. */ | |
d95f5ba9 | 100 | |
90127d60 | 101 | if (verbose > 1) |
d95f5ba9 PM |
102 | pr_alert("%s" TORTURE_FLAG |
103 | "torture_onoff task: offlining %d\n", | |
104 | torture_type, cpu); | |
105 | starttime = jiffies; | |
106 | (*n_offl_attempts)++; | |
457bc8ed | 107 | ret = remove_cpu(cpu); |
d95f5ba9 | 108 | if (ret) { |
a59ee765 PM |
109 | s = ""; |
110 | if (!rcu_inkernel_boot_has_ended() && ret == -EBUSY) { | |
111 | // PCI probe frequently disables hotplug during boot. | |
112 | (*n_offl_attempts)--; | |
113 | s = " (-EBUSY forgiven during boot)"; | |
114 | } | |
d95f5ba9 PM |
115 | if (verbose) |
116 | pr_alert("%s" TORTURE_FLAG | |
a59ee765 PM |
117 | "torture_onoff task: offline %d failed%s: errno %d\n", |
118 | torture_type, cpu, s, ret); | |
d95f5ba9 | 119 | } else { |
90127d60 | 120 | if (verbose > 1) |
d95f5ba9 PM |
121 | pr_alert("%s" TORTURE_FLAG |
122 | "torture_onoff task: offlined %d\n", | |
123 | torture_type, cpu); | |
3a6cb58f PM |
124 | if (onoff_f) |
125 | onoff_f(); | |
d95f5ba9 PM |
126 | (*n_offl_successes)++; |
127 | delta = jiffies - starttime; | |
a2b2df20 | 128 | *sum_offl += delta; |
d95f5ba9 PM |
129 | if (*min_offl < 0) { |
130 | *min_offl = delta; | |
131 | *max_offl = delta; | |
132 | } | |
133 | if (*min_offl > delta) | |
134 | *min_offl = delta; | |
135 | if (*max_offl < delta) | |
136 | *max_offl = delta; | |
137 | } | |
138 | ||
139 | return true; | |
140 | } | |
141 | EXPORT_SYMBOL_GPL(torture_offline); | |
142 | ||
143 | /* | |
144 | * Attempt to bring a CPU online. Return false if the CPU is already | |
145 | * online or if it is not subject to CPU-hotplug operations. The | |
146 | * caller can detect other failures by looking at the statistics. | |
147 | */ | |
148 | bool torture_online(int cpu, long *n_onl_attempts, long *n_onl_successes, | |
149 | unsigned long *sum_onl, int *min_onl, int *max_onl) | |
150 | { | |
151 | unsigned long delta; | |
152 | int ret; | |
a59ee765 | 153 | char *s; |
d95f5ba9 PM |
154 | unsigned long starttime; |
155 | ||
156 | if (cpu_online(cpu) || !cpu_is_hotpluggable(cpu)) | |
157 | return false; | |
158 | ||
90127d60 | 159 | if (verbose > 1) |
d95f5ba9 PM |
160 | pr_alert("%s" TORTURE_FLAG |
161 | "torture_onoff task: onlining %d\n", | |
162 | torture_type, cpu); | |
163 | starttime = jiffies; | |
164 | (*n_onl_attempts)++; | |
457bc8ed | 165 | ret = add_cpu(cpu); |
d95f5ba9 | 166 | if (ret) { |
a59ee765 PM |
167 | s = ""; |
168 | if (!rcu_inkernel_boot_has_ended() && ret == -EBUSY) { | |
169 | // PCI probe frequently disables hotplug during boot. | |
170 | (*n_onl_attempts)--; | |
171 | s = " (-EBUSY forgiven during boot)"; | |
172 | } | |
d95f5ba9 PM |
173 | if (verbose) |
174 | pr_alert("%s" TORTURE_FLAG | |
a59ee765 PM |
175 | "torture_onoff task: online %d failed%s: errno %d\n", |
176 | torture_type, cpu, s, ret); | |
d95f5ba9 | 177 | } else { |
90127d60 | 178 | if (verbose > 1) |
d95f5ba9 PM |
179 | pr_alert("%s" TORTURE_FLAG |
180 | "torture_onoff task: onlined %d\n", | |
181 | torture_type, cpu); | |
182 | (*n_onl_successes)++; | |
183 | delta = jiffies - starttime; | |
184 | *sum_onl += delta; | |
185 | if (*min_onl < 0) { | |
186 | *min_onl = delta; | |
187 | *max_onl = delta; | |
188 | } | |
189 | if (*min_onl > delta) | |
190 | *min_onl = delta; | |
191 | if (*max_onl < delta) | |
192 | *max_onl = delta; | |
193 | } | |
194 | ||
195 | return true; | |
196 | } | |
197 | EXPORT_SYMBOL_GPL(torture_online); | |
198 | ||
2e9e8081 PM |
199 | /* |
200 | * Execute random CPU-hotplug operations at the interval specified | |
201 | * by the onoff_interval. | |
202 | */ | |
203 | static int | |
204 | torture_onoff(void *arg) | |
205 | { | |
206 | int cpu; | |
2e9e8081 PM |
207 | int maxcpu = -1; |
208 | DEFINE_TORTURE_RANDOM(rand); | |
28cf5952 | 209 | int ret; |
2e9e8081 PM |
210 | |
211 | VERBOSE_TOROUT_STRING("torture_onoff task started"); | |
212 | for_each_online_cpu(cpu) | |
213 | maxcpu = cpu; | |
214 | WARN_ON(maxcpu < 0); | |
457bc8ed | 215 | if (!IS_MODULE(CONFIG_TORTURE_TEST)) { |
28cf5952 PM |
216 | for_each_possible_cpu(cpu) { |
217 | if (cpu_online(cpu)) | |
218 | continue; | |
457bc8ed | 219 | ret = add_cpu(cpu); |
28cf5952 PM |
220 | if (ret && verbose) { |
221 | pr_alert("%s" TORTURE_FLAG | |
222 | "%s: Initial online %d: errno %d\n", | |
223 | __func__, torture_type, cpu, ret); | |
224 | } | |
225 | } | |
457bc8ed | 226 | } |
750db0f5 BF |
227 | |
228 | if (maxcpu == 0) { | |
229 | VERBOSE_TOROUT_STRING("Only one CPU, so CPU-hotplug testing is disabled"); | |
230 | goto stop; | |
231 | } | |
232 | ||
2e9e8081 PM |
233 | if (onoff_holdoff > 0) { |
234 | VERBOSE_TOROUT_STRING("torture_onoff begin holdoff"); | |
235 | schedule_timeout_interruptible(onoff_holdoff); | |
236 | VERBOSE_TOROUT_STRING("torture_onoff end holdoff"); | |
237 | } | |
238 | while (!torture_must_stop()) { | |
8171d3e0 PM |
239 | if (disable_onoff_at_boot && !rcu_inkernel_boot_has_ended()) { |
240 | schedule_timeout_interruptible(HZ / 10); | |
241 | continue; | |
242 | } | |
2e9e8081 | 243 | cpu = (torture_random(&rand) >> 4) % (maxcpu + 1); |
d95f5ba9 PM |
244 | if (!torture_offline(cpu, |
245 | &n_offline_attempts, &n_offline_successes, | |
246 | &sum_offline, &min_offline, &max_offline)) | |
247 | torture_online(cpu, | |
248 | &n_online_attempts, &n_online_successes, | |
249 | &sum_online, &min_online, &max_online); | |
2e9e8081 PM |
250 | schedule_timeout_interruptible(onoff_interval); |
251 | } | |
750db0f5 BF |
252 | |
253 | stop: | |
7fafaac5 | 254 | torture_kthread_stopping("torture_onoff"); |
2e9e8081 PM |
255 | return 0; |
256 | } | |
257 | ||
258 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ | |
259 | ||
260 | /* | |
261 | * Initiate online-offline handling. | |
262 | */ | |
3a6cb58f | 263 | int torture_onoff_init(long ooholdoff, long oointerval, torture_ofl_func *f) |
2e9e8081 | 264 | { |
47cf29b9 | 265 | #ifdef CONFIG_HOTPLUG_CPU |
2e9e8081 PM |
266 | onoff_holdoff = ooholdoff; |
267 | onoff_interval = oointerval; | |
3a6cb58f | 268 | onoff_f = f; |
2e9e8081 PM |
269 | if (onoff_interval <= 0) |
270 | return 0; | |
2a7d9688 PG |
271 | return torture_create_kthread(torture_onoff, NULL, onoff_task); |
272 | #else /* #ifdef CONFIG_HOTPLUG_CPU */ | |
273 | return 0; | |
274 | #endif /* #else #ifdef CONFIG_HOTPLUG_CPU */ | |
2e9e8081 PM |
275 | } |
276 | EXPORT_SYMBOL_GPL(torture_onoff_init); | |
277 | ||
278 | /* | |
279 | * Clean up after online/offline testing. | |
280 | */ | |
cc47ae08 | 281 | static void torture_onoff_cleanup(void) |
2e9e8081 PM |
282 | { |
283 | #ifdef CONFIG_HOTPLUG_CPU | |
284 | if (onoff_task == NULL) | |
285 | return; | |
286 | VERBOSE_TOROUT_STRING("Stopping torture_onoff task"); | |
287 | kthread_stop(onoff_task); | |
288 | onoff_task = NULL; | |
289 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ | |
290 | } | |
2e9e8081 PM |
291 | |
292 | /* | |
293 | * Print online/offline testing statistics. | |
294 | */ | |
eea203fe | 295 | void torture_onoff_stats(void) |
2e9e8081 PM |
296 | { |
297 | #ifdef CONFIG_HOTPLUG_CPU | |
eea203fe JP |
298 | pr_cont("onoff: %ld/%ld:%ld/%ld %d,%d:%d,%d %lu:%lu (HZ=%d) ", |
299 | n_online_successes, n_online_attempts, | |
300 | n_offline_successes, n_offline_attempts, | |
301 | min_online, max_online, | |
302 | min_offline, max_offline, | |
303 | sum_online, sum_offline, HZ); | |
2e9e8081 | 304 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ |
2e9e8081 PM |
305 | } |
306 | EXPORT_SYMBOL_GPL(torture_onoff_stats); | |
307 | ||
308 | /* | |
309 | * Were all the online/offline operations successful? | |
310 | */ | |
311 | bool torture_onoff_failures(void) | |
312 | { | |
313 | #ifdef CONFIG_HOTPLUG_CPU | |
314 | return n_online_successes != n_online_attempts || | |
315 | n_offline_successes != n_offline_attempts; | |
316 | #else /* #ifdef CONFIG_HOTPLUG_CPU */ | |
317 | return false; | |
318 | #endif /* #else #ifdef CONFIG_HOTPLUG_CPU */ | |
319 | } | |
320 | EXPORT_SYMBOL_GPL(torture_onoff_failures); | |
321 | ||
51b1130e PM |
322 | #define TORTURE_RANDOM_MULT 39916801 /* prime */ |
323 | #define TORTURE_RANDOM_ADD 479001701 /* prime */ | |
324 | #define TORTURE_RANDOM_REFRESH 10000 | |
325 | ||
326 | /* | |
327 | * Crude but fast random-number generator. Uses a linear congruential | |
328 | * generator, with occasional help from cpu_clock(). | |
329 | */ | |
330 | unsigned long | |
331 | torture_random(struct torture_random_state *trsp) | |
332 | { | |
333 | if (--trsp->trs_count < 0) { | |
334 | trsp->trs_state += (unsigned long)local_clock(); | |
335 | trsp->trs_count = TORTURE_RANDOM_REFRESH; | |
336 | } | |
337 | trsp->trs_state = trsp->trs_state * TORTURE_RANDOM_MULT + | |
338 | TORTURE_RANDOM_ADD; | |
339 | return swahw32(trsp->trs_state); | |
340 | } | |
341 | EXPORT_SYMBOL_GPL(torture_random); | |
f67a3356 | 342 | |
3808dc9f PM |
343 | /* |
344 | * Variables for shuffling. The idea is to ensure that each CPU stays | |
345 | * idle for an extended period to test interactions with dyntick idle, | |
b564d62e | 346 | * as well as interactions with any per-CPU variables. |
3808dc9f PM |
347 | */ |
348 | struct shuffle_task { | |
349 | struct list_head st_l; | |
350 | struct task_struct *st_t; | |
351 | }; | |
352 | ||
353 | static long shuffle_interval; /* In jiffies. */ | |
354 | static struct task_struct *shuffler_task; | |
355 | static cpumask_var_t shuffle_tmp_mask; | |
356 | static int shuffle_idle_cpu; /* Force all torture tasks off this CPU */ | |
357 | static struct list_head shuffle_task_list = LIST_HEAD_INIT(shuffle_task_list); | |
358 | static DEFINE_MUTEX(shuffle_task_mutex); | |
359 | ||
360 | /* | |
361 | * Register a task to be shuffled. If there is no memory, just splat | |
362 | * and don't bother registering. | |
363 | */ | |
364 | void torture_shuffle_task_register(struct task_struct *tp) | |
365 | { | |
366 | struct shuffle_task *stp; | |
367 | ||
368 | if (WARN_ON_ONCE(tp == NULL)) | |
369 | return; | |
370 | stp = kmalloc(sizeof(*stp), GFP_KERNEL); | |
371 | if (WARN_ON_ONCE(stp == NULL)) | |
372 | return; | |
373 | stp->st_t = tp; | |
374 | mutex_lock(&shuffle_task_mutex); | |
375 | list_add(&stp->st_l, &shuffle_task_list); | |
376 | mutex_unlock(&shuffle_task_mutex); | |
377 | } | |
378 | EXPORT_SYMBOL_GPL(torture_shuffle_task_register); | |
379 | ||
380 | /* | |
381 | * Unregister all tasks, for example, at the end of the torture run. | |
382 | */ | |
383 | static void torture_shuffle_task_unregister_all(void) | |
384 | { | |
385 | struct shuffle_task *stp; | |
386 | struct shuffle_task *p; | |
387 | ||
388 | mutex_lock(&shuffle_task_mutex); | |
389 | list_for_each_entry_safe(stp, p, &shuffle_task_list, st_l) { | |
390 | list_del(&stp->st_l); | |
391 | kfree(stp); | |
392 | } | |
393 | mutex_unlock(&shuffle_task_mutex); | |
394 | } | |
395 | ||
396 | /* Shuffle tasks such that we allow shuffle_idle_cpu to become idle. | |
397 | * A special case is when shuffle_idle_cpu = -1, in which case we allow | |
398 | * the tasks to run on all CPUs. | |
399 | */ | |
400 | static void torture_shuffle_tasks(void) | |
401 | { | |
402 | struct shuffle_task *stp; | |
403 | ||
404 | cpumask_setall(shuffle_tmp_mask); | |
405 | get_online_cpus(); | |
406 | ||
407 | /* No point in shuffling if there is only one online CPU (ex: UP) */ | |
408 | if (num_online_cpus() == 1) { | |
409 | put_online_cpus(); | |
410 | return; | |
411 | } | |
412 | ||
413 | /* Advance to the next CPU. Upon overflow, don't idle any CPUs. */ | |
414 | shuffle_idle_cpu = cpumask_next(shuffle_idle_cpu, shuffle_tmp_mask); | |
415 | if (shuffle_idle_cpu >= nr_cpu_ids) | |
416 | shuffle_idle_cpu = -1; | |
5ed63b19 | 417 | else |
3808dc9f | 418 | cpumask_clear_cpu(shuffle_idle_cpu, shuffle_tmp_mask); |
3808dc9f PM |
419 | |
420 | mutex_lock(&shuffle_task_mutex); | |
421 | list_for_each_entry(stp, &shuffle_task_list, st_l) | |
422 | set_cpus_allowed_ptr(stp->st_t, shuffle_tmp_mask); | |
423 | mutex_unlock(&shuffle_task_mutex); | |
424 | ||
425 | put_online_cpus(); | |
426 | } | |
427 | ||
428 | /* Shuffle tasks across CPUs, with the intent of allowing each CPU in the | |
429 | * system to become idle at a time and cut off its timer ticks. This is meant | |
430 | * to test the support for such tickless idle CPU in RCU. | |
431 | */ | |
432 | static int torture_shuffle(void *arg) | |
433 | { | |
434 | VERBOSE_TOROUT_STRING("torture_shuffle task started"); | |
435 | do { | |
436 | schedule_timeout_interruptible(shuffle_interval); | |
437 | torture_shuffle_tasks(); | |
438 | torture_shutdown_absorb("torture_shuffle"); | |
439 | } while (!torture_must_stop()); | |
7fafaac5 | 440 | torture_kthread_stopping("torture_shuffle"); |
3808dc9f PM |
441 | return 0; |
442 | } | |
443 | ||
444 | /* | |
445 | * Start the shuffler, with shuffint in jiffies. | |
446 | */ | |
447 | int torture_shuffle_init(long shuffint) | |
448 | { | |
3808dc9f PM |
449 | shuffle_interval = shuffint; |
450 | ||
451 | shuffle_idle_cpu = -1; | |
452 | ||
453 | if (!alloc_cpumask_var(&shuffle_tmp_mask, GFP_KERNEL)) { | |
454 | VERBOSE_TOROUT_ERRSTRING("Failed to alloc mask"); | |
455 | return -ENOMEM; | |
456 | } | |
457 | ||
458 | /* Create the shuffler thread */ | |
47cf29b9 | 459 | return torture_create_kthread(torture_shuffle, NULL, shuffler_task); |
3808dc9f PM |
460 | } |
461 | EXPORT_SYMBOL_GPL(torture_shuffle_init); | |
462 | ||
463 | /* | |
464 | * Stop the shuffling. | |
465 | */ | |
cc47ae08 | 466 | static void torture_shuffle_cleanup(void) |
3808dc9f PM |
467 | { |
468 | torture_shuffle_task_unregister_all(); | |
469 | if (shuffler_task) { | |
470 | VERBOSE_TOROUT_STRING("Stopping torture_shuffle task"); | |
471 | kthread_stop(shuffler_task); | |
472 | free_cpumask_var(shuffle_tmp_mask); | |
473 | } | |
474 | shuffler_task = NULL; | |
475 | } | |
3808dc9f | 476 | |
e991dbc0 PM |
477 | /* |
478 | * Variables for auto-shutdown. This allows "lights out" torture runs | |
479 | * to be fully scripted. | |
480 | */ | |
e991dbc0 | 481 | static struct task_struct *shutdown_task; |
31257c3c | 482 | static ktime_t shutdown_time; /* time to system shutdown. */ |
e991dbc0 PM |
483 | static void (*torture_shutdown_hook)(void); |
484 | ||
f67a3356 PM |
485 | /* |
486 | * Absorb kthreads into a kernel function that won't return, so that | |
487 | * they won't ever access module text or data again. | |
488 | */ | |
489 | void torture_shutdown_absorb(const char *title) | |
490 | { | |
7d0ae808 | 491 | while (READ_ONCE(fullstop) == FULLSTOP_SHUTDOWN) { |
4622b487 PM |
492 | pr_notice("torture thread %s parking due to system shutdown\n", |
493 | title); | |
f67a3356 PM |
494 | schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT); |
495 | } | |
496 | } | |
497 | EXPORT_SYMBOL_GPL(torture_shutdown_absorb); | |
b5daa8f3 | 498 | |
e991dbc0 PM |
499 | /* |
500 | * Cause the torture test to shutdown the system after the test has | |
501 | * run for the time specified by the shutdown_secs parameter. | |
502 | */ | |
503 | static int torture_shutdown(void *arg) | |
504 | { | |
31257c3c | 505 | ktime_t ktime_snap; |
e991dbc0 PM |
506 | |
507 | VERBOSE_TOROUT_STRING("torture_shutdown task started"); | |
31257c3c PM |
508 | ktime_snap = ktime_get(); |
509 | while (ktime_before(ktime_snap, shutdown_time) && | |
e991dbc0 | 510 | !torture_must_stop()) { |
e991dbc0 PM |
511 | if (verbose) |
512 | pr_alert("%s" TORTURE_FLAG | |
31257c3c PM |
513 | "torture_shutdown task: %llu ms remaining\n", |
514 | torture_type, | |
515 | ktime_ms_delta(shutdown_time, ktime_snap)); | |
516 | set_current_state(TASK_INTERRUPTIBLE); | |
517 | schedule_hrtimeout(&shutdown_time, HRTIMER_MODE_ABS); | |
518 | ktime_snap = ktime_get(); | |
e991dbc0 PM |
519 | } |
520 | if (torture_must_stop()) { | |
7fafaac5 | 521 | torture_kthread_stopping("torture_shutdown"); |
e991dbc0 PM |
522 | return 0; |
523 | } | |
524 | ||
525 | /* OK, shut down the system. */ | |
526 | ||
527 | VERBOSE_TOROUT_STRING("torture_shutdown task shutting down system"); | |
528 | shutdown_task = NULL; /* Avoid self-kill deadlock. */ | |
f881825a PM |
529 | if (torture_shutdown_hook) |
530 | torture_shutdown_hook(); | |
531 | else | |
532 | VERBOSE_TOROUT_STRING("No torture_shutdown_hook(), skipping."); | |
2102ad29 PM |
533 | if (ftrace_dump_at_shutdown) |
534 | rcu_ftrace_dump(DUMP_ALL); | |
e991dbc0 PM |
535 | kernel_power_off(); /* Shut down the system. */ |
536 | return 0; | |
537 | } | |
538 | ||
539 | /* | |
540 | * Start up the shutdown task. | |
541 | */ | |
542 | int torture_shutdown_init(int ssecs, void (*cleanup)(void)) | |
543 | { | |
e991dbc0 | 544 | torture_shutdown_hook = cleanup; |
31257c3c PM |
545 | if (ssecs > 0) { |
546 | shutdown_time = ktime_add(ktime_get(), ktime_set(ssecs, 0)); | |
2a7d9688 | 547 | return torture_create_kthread(torture_shutdown, NULL, |
47cf29b9 | 548 | shutdown_task); |
e991dbc0 | 549 | } |
2a7d9688 | 550 | return 0; |
e991dbc0 PM |
551 | } |
552 | EXPORT_SYMBOL_GPL(torture_shutdown_init); | |
553 | ||
4622b487 PM |
554 | /* |
555 | * Detect and respond to a system shutdown. | |
556 | */ | |
557 | static int torture_shutdown_notify(struct notifier_block *unused1, | |
558 | unsigned long unused2, void *unused3) | |
559 | { | |
560 | mutex_lock(&fullstop_mutex); | |
7d0ae808 | 561 | if (READ_ONCE(fullstop) == FULLSTOP_DONTSTOP) { |
fac480ef | 562 | VERBOSE_TOROUT_STRING("Unscheduled system shutdown detected"); |
7d0ae808 | 563 | WRITE_ONCE(fullstop, FULLSTOP_SHUTDOWN); |
fac480ef | 564 | } else { |
4622b487 | 565 | pr_warn("Concurrent rmmod and shutdown illegal!\n"); |
fac480ef | 566 | } |
4622b487 PM |
567 | mutex_unlock(&fullstop_mutex); |
568 | return NOTIFY_DONE; | |
569 | } | |
570 | ||
571 | static struct notifier_block torture_shutdown_nb = { | |
572 | .notifier_call = torture_shutdown_notify, | |
573 | }; | |
574 | ||
bfefc73a PM |
575 | /* |
576 | * Shut down the shutdown task. Say what??? Heh! This can happen if | |
577 | * the torture module gets an rmmod before the shutdown time arrives. ;-) | |
578 | */ | |
579 | static void torture_shutdown_cleanup(void) | |
580 | { | |
581 | unregister_reboot_notifier(&torture_shutdown_nb); | |
582 | if (shutdown_task != NULL) { | |
583 | VERBOSE_TOROUT_STRING("Stopping torture_shutdown task"); | |
584 | kthread_stop(shutdown_task); | |
585 | } | |
586 | shutdown_task = NULL; | |
587 | } | |
588 | ||
628edaa5 PM |
589 | /* |
590 | * Variables for stuttering, which means to periodically pause and | |
591 | * restart testing in order to catch bugs that appear when load is | |
592 | * suddenly applied to or removed from the system. | |
593 | */ | |
594 | static struct task_struct *stutter_task; | |
595 | static int stutter_pause_test; | |
596 | static int stutter; | |
ff3bf92d | 597 | static int stutter_gap; |
628edaa5 PM |
598 | |
599 | /* | |
600 | * Block until the stutter interval ends. This must be called periodically | |
601 | * by all running kthreads that need to be subject to stuttering. | |
602 | */ | |
474e59b4 | 603 | bool stutter_wait(const char *title) |
628edaa5 | 604 | { |
4ced3314 | 605 | int spt; |
e8516c64 | 606 | bool ret = false; |
4ced3314 | 607 | |
cee43939 | 608 | cond_resched_tasks_rcu_qs(); |
4ced3314 | 609 | spt = READ_ONCE(stutter_pause_test); |
29d39390 | 610 | for (; spt; spt = READ_ONCE(stutter_pause_test)) { |
e8516c64 | 611 | ret = true; |
4ced3314 PM |
612 | if (spt == 1) { |
613 | schedule_timeout_interruptible(1); | |
614 | } else if (spt == 2) { | |
615 | while (READ_ONCE(stutter_pause_test)) | |
616 | cond_resched(); | |
617 | } else { | |
628edaa5 | 618 | schedule_timeout_interruptible(round_jiffies_relative(HZ)); |
4ced3314 | 619 | } |
628edaa5 PM |
620 | torture_shutdown_absorb(title); |
621 | } | |
e8516c64 | 622 | return ret; |
628edaa5 PM |
623 | } |
624 | EXPORT_SYMBOL_GPL(stutter_wait); | |
625 | ||
626 | /* | |
627 | * Cause the torture test to "stutter", starting and stopping all | |
628 | * threads periodically. | |
629 | */ | |
630 | static int torture_stutter(void *arg) | |
631 | { | |
e8516c64 PM |
632 | int wtime; |
633 | ||
628edaa5 PM |
634 | VERBOSE_TOROUT_STRING("torture_stutter task started"); |
635 | do { | |
4ced3314 | 636 | if (!torture_must_stop() && stutter > 1) { |
e8516c64 PM |
637 | wtime = stutter; |
638 | if (stutter > HZ + 1) { | |
639 | WRITE_ONCE(stutter_pause_test, 1); | |
640 | wtime = stutter - HZ - 1; | |
641 | schedule_timeout_interruptible(wtime); | |
642 | wtime = HZ + 1; | |
643 | } | |
4ced3314 | 644 | WRITE_ONCE(stutter_pause_test, 2); |
e8516c64 | 645 | schedule_timeout_interruptible(wtime); |
628edaa5 | 646 | } |
4ced3314 | 647 | WRITE_ONCE(stutter_pause_test, 0); |
628edaa5 | 648 | if (!torture_must_stop()) |
ff3bf92d | 649 | schedule_timeout_interruptible(stutter_gap); |
628edaa5 PM |
650 | torture_shutdown_absorb("torture_stutter"); |
651 | } while (!torture_must_stop()); | |
7fafaac5 | 652 | torture_kthread_stopping("torture_stutter"); |
628edaa5 PM |
653 | return 0; |
654 | } | |
655 | ||
656 | /* | |
657 | * Initialize and kick off the torture_stutter kthread. | |
658 | */ | |
ff3bf92d | 659 | int torture_stutter_init(const int s, const int sgap) |
628edaa5 | 660 | { |
628edaa5 | 661 | stutter = s; |
ff3bf92d | 662 | stutter_gap = sgap; |
2a7d9688 | 663 | return torture_create_kthread(torture_stutter, NULL, stutter_task); |
628edaa5 PM |
664 | } |
665 | EXPORT_SYMBOL_GPL(torture_stutter_init); | |
666 | ||
667 | /* | |
668 | * Cleanup after the torture_stutter kthread. | |
669 | */ | |
bfefc73a | 670 | static void torture_stutter_cleanup(void) |
628edaa5 PM |
671 | { |
672 | if (!stutter_task) | |
673 | return; | |
674 | VERBOSE_TOROUT_STRING("Stopping torture_stutter task"); | |
675 | kthread_stop(stutter_task); | |
676 | stutter_task = NULL; | |
677 | } | |
628edaa5 | 678 | |
b5daa8f3 PM |
679 | /* |
680 | * Initialize torture module. Please note that this is -not- invoked via | |
681 | * the usual module_init() mechanism, but rather by an explicit call from | |
682 | * the client torture module. This call must be paired with a later | |
683 | * torture_init_end(). | |
628edaa5 PM |
684 | * |
685 | * The runnable parameter points to a flag that controls whether or not | |
686 | * the test is currently runnable. If there is no such flag, pass in NULL. | |
b5daa8f3 | 687 | */ |
90127d60 | 688 | bool torture_init_begin(char *ttype, int v) |
b5daa8f3 PM |
689 | { |
690 | mutex_lock(&fullstop_mutex); | |
5228084e | 691 | if (torture_type != NULL) { |
9eb5188a | 692 | pr_alert("torture_init_begin: Refusing %s init: %s running.\n", |
5228084e | 693 | ttype, torture_type); |
9eb5188a | 694 | pr_alert("torture_init_begin: One torture test at a time!\n"); |
5228084e PM |
695 | mutex_unlock(&fullstop_mutex); |
696 | return false; | |
697 | } | |
b5daa8f3 PM |
698 | torture_type = ttype; |
699 | verbose = v; | |
36970bb9 | 700 | fullstop = FULLSTOP_DONTSTOP; |
5228084e | 701 | return true; |
b5daa8f3 PM |
702 | } |
703 | EXPORT_SYMBOL_GPL(torture_init_begin); | |
704 | ||
705 | /* | |
706 | * Tell the torture module that initialization is complete. | |
707 | */ | |
2b3f8ffe | 708 | void torture_init_end(void) |
b5daa8f3 PM |
709 | { |
710 | mutex_unlock(&fullstop_mutex); | |
4622b487 | 711 | register_reboot_notifier(&torture_shutdown_nb); |
b5daa8f3 PM |
712 | } |
713 | EXPORT_SYMBOL_GPL(torture_init_end); | |
cc47ae08 PM |
714 | |
715 | /* | |
716 | * Clean up torture module. Please note that this is -not- invoked via | |
717 | * the usual module_exit() mechanism, but rather by an explicit call from | |
718 | * the client torture module. Returns true if a race with system shutdown | |
bfefc73a PM |
719 | * is detected, otherwise, all kthreads started by functions in this file |
720 | * will be shut down. | |
cc47ae08 PM |
721 | * |
722 | * This must be called before the caller starts shutting down its own | |
723 | * kthreads. | |
d36a7a0d DB |
724 | * |
725 | * Both torture_cleanup_begin() and torture_cleanup_end() must be paired, | |
726 | * in order to correctly perform the cleanup. They are separated because | |
727 | * threads can still need to reference the torture_type type, thus nullify | |
728 | * only after completing all other relevant calls. | |
cc47ae08 | 729 | */ |
d36a7a0d | 730 | bool torture_cleanup_begin(void) |
cc47ae08 PM |
731 | { |
732 | mutex_lock(&fullstop_mutex); | |
7d0ae808 | 733 | if (READ_ONCE(fullstop) == FULLSTOP_SHUTDOWN) { |
cc47ae08 PM |
734 | pr_warn("Concurrent rmmod and shutdown illegal!\n"); |
735 | mutex_unlock(&fullstop_mutex); | |
736 | schedule_timeout_uninterruptible(10); | |
737 | return true; | |
738 | } | |
7d0ae808 | 739 | WRITE_ONCE(fullstop, FULLSTOP_RMMOD); |
cc47ae08 | 740 | mutex_unlock(&fullstop_mutex); |
bfefc73a | 741 | torture_shutdown_cleanup(); |
cc47ae08 | 742 | torture_shuffle_cleanup(); |
bfefc73a | 743 | torture_stutter_cleanup(); |
cc47ae08 | 744 | torture_onoff_cleanup(); |
d36a7a0d DB |
745 | return false; |
746 | } | |
747 | EXPORT_SYMBOL_GPL(torture_cleanup_begin); | |
748 | ||
749 | void torture_cleanup_end(void) | |
750 | { | |
5228084e PM |
751 | mutex_lock(&fullstop_mutex); |
752 | torture_type = NULL; | |
753 | mutex_unlock(&fullstop_mutex); | |
cc47ae08 | 754 | } |
d36a7a0d | 755 | EXPORT_SYMBOL_GPL(torture_cleanup_end); |
36970bb9 PM |
756 | |
757 | /* | |
758 | * Is it time for the current torture test to stop? | |
759 | */ | |
760 | bool torture_must_stop(void) | |
761 | { | |
762 | return torture_must_stop_irq() || kthread_should_stop(); | |
763 | } | |
764 | EXPORT_SYMBOL_GPL(torture_must_stop); | |
765 | ||
766 | /* | |
767 | * Is it time for the current torture test to stop? This is the irq-safe | |
768 | * version, hence no check for kthread_should_stop(). | |
769 | */ | |
770 | bool torture_must_stop_irq(void) | |
771 | { | |
7d0ae808 | 772 | return READ_ONCE(fullstop) != FULLSTOP_DONTSTOP; |
36970bb9 PM |
773 | } |
774 | EXPORT_SYMBOL_GPL(torture_must_stop_irq); | |
7fafaac5 PM |
775 | |
776 | /* | |
777 | * Each kthread must wait for kthread_should_stop() before returning from | |
778 | * its top-level function, otherwise segfaults ensue. This function | |
779 | * prints a "stopping" message and waits for kthread_should_stop(), and | |
780 | * should be called from all torture kthreads immediately prior to | |
781 | * returning. | |
782 | */ | |
783 | void torture_kthread_stopping(char *title) | |
784 | { | |
0d6821d5 PM |
785 | char buf[128]; |
786 | ||
787 | snprintf(buf, sizeof(buf), "Stopping %s", title); | |
788 | VERBOSE_TOROUT_STRING(buf); | |
7fafaac5 PM |
789 | while (!kthread_should_stop()) { |
790 | torture_shutdown_absorb(title); | |
791 | schedule_timeout_uninterruptible(1); | |
792 | } | |
793 | } | |
794 | EXPORT_SYMBOL_GPL(torture_kthread_stopping); | |
47cf29b9 PM |
795 | |
796 | /* | |
797 | * Create a generic torture kthread that is immediately runnable. If you | |
798 | * need the kthread to be stopped so that you can do something to it before | |
799 | * it starts, you will need to open-code your own. | |
800 | */ | |
801 | int _torture_create_kthread(int (*fn)(void *arg), void *arg, char *s, char *m, | |
802 | char *f, struct task_struct **tp) | |
803 | { | |
804 | int ret = 0; | |
805 | ||
806 | VERBOSE_TOROUT_STRING(m); | |
6945915e | 807 | *tp = kthread_run(fn, arg, "%s", s); |
47cf29b9 PM |
808 | if (IS_ERR(*tp)) { |
809 | ret = PTR_ERR(*tp); | |
810 | VERBOSE_TOROUT_ERRSTRING(f); | |
811 | *tp = NULL; | |
812 | } | |
813 | torture_shuffle_task_register(*tp); | |
814 | return ret; | |
815 | } | |
816 | EXPORT_SYMBOL_GPL(_torture_create_kthread); | |
9c029b86 PM |
817 | |
818 | /* | |
819 | * Stop a generic kthread, emitting a message. | |
820 | */ | |
821 | void _torture_stop_kthread(char *m, struct task_struct **tp) | |
822 | { | |
823 | if (*tp == NULL) | |
824 | return; | |
825 | VERBOSE_TOROUT_STRING(m); | |
826 | kthread_stop(*tp); | |
827 | *tp = NULL; | |
828 | } | |
829 | EXPORT_SYMBOL_GPL(_torture_stop_kthread); |