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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> | |
5d248bb3 | 40 | #include <linux/sched/rt.h> |
dac95906 | 41 | #include "rcu/rcu.h" |
51b1130e | 42 | |
a8469dc6 | 43 | MODULE_DESCRIPTION("Common functions for in-kernel torture tests"); |
51b1130e | 44 | MODULE_LICENSE("GPL"); |
8f8e76c0 | 45 | MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com>"); |
51b1130e | 46 | |
8171d3e0 PM |
47 | static bool disable_onoff_at_boot; |
48 | module_param(disable_onoff_at_boot, bool, 0444); | |
49 | ||
2102ad29 PM |
50 | static bool ftrace_dump_at_shutdown; |
51 | module_param(ftrace_dump_at_shutdown, bool, 0444); | |
52 | ||
8a67a20b PM |
53 | static int verbose_sleep_frequency; |
54 | module_param(verbose_sleep_frequency, int, 0444); | |
55 | ||
56 | static int verbose_sleep_duration = 1; | |
57 | module_param(verbose_sleep_duration, int, 0444); | |
58 | ||
e2a0b786 CB |
59 | static int random_shuffle; |
60 | module_param(random_shuffle, int, 0444); | |
61 | ||
b5daa8f3 | 62 | static char *torture_type; |
90127d60 | 63 | static int verbose; |
b5daa8f3 | 64 | |
36970bb9 PM |
65 | /* Mediate rmmod and system shutdown. Concurrent rmmod & shutdown illegal! */ |
66 | #define FULLSTOP_DONTSTOP 0 /* Normal operation. */ | |
67 | #define FULLSTOP_SHUTDOWN 1 /* System shutdown with torture running. */ | |
68 | #define FULLSTOP_RMMOD 2 /* Normal rmmod of torture. */ | |
69 | static int fullstop = FULLSTOP_RMMOD; | |
4622b487 | 70 | static DEFINE_MUTEX(fullstop_mutex); |
f67a3356 | 71 | |
8a67a20b PM |
72 | static atomic_t verbose_sleep_counter; |
73 | ||
74 | /* | |
75 | * Sleep if needed from VERBOSE_TOROUT*(). | |
76 | */ | |
77 | void verbose_torout_sleep(void) | |
78 | { | |
79 | if (verbose_sleep_frequency > 0 && | |
80 | verbose_sleep_duration > 0 && | |
81 | !(atomic_inc_return(&verbose_sleep_counter) % verbose_sleep_frequency)) | |
82 | schedule_timeout_uninterruptible(verbose_sleep_duration); | |
83 | } | |
84 | EXPORT_SYMBOL_GPL(verbose_torout_sleep); | |
85 | ||
ae19aaaf PM |
86 | /* |
87 | * Schedule a high-resolution-timer sleep in nanoseconds, with a 32-bit | |
88 | * nanosecond random fuzz. This function and its friends desynchronize | |
89 | * testing from the timer wheel. | |
90 | */ | |
a741deac PM |
91 | int torture_hrtimeout_ns(ktime_t baset_ns, u32 fuzzt_ns, const enum hrtimer_mode mode, |
92 | struct torture_random_state *trsp) | |
ae19aaaf PM |
93 | { |
94 | ktime_t hto = baset_ns; | |
95 | ||
96 | if (trsp) | |
6cab60ce | 97 | hto += torture_random(trsp) % fuzzt_ns; |
872948c6 | 98 | set_current_state(TASK_IDLE); |
a741deac | 99 | return schedule_hrtimeout(&hto, mode); |
ae19aaaf PM |
100 | } |
101 | EXPORT_SYMBOL_GPL(torture_hrtimeout_ns); | |
102 | ||
103 | /* | |
104 | * Schedule a high-resolution-timer sleep in microseconds, with a 32-bit | |
105 | * nanosecond (not microsecond!) random fuzz. | |
106 | */ | |
107 | int torture_hrtimeout_us(u32 baset_us, u32 fuzzt_ns, struct torture_random_state *trsp) | |
108 | { | |
109 | ktime_t baset_ns = baset_us * NSEC_PER_USEC; | |
110 | ||
a741deac | 111 | return torture_hrtimeout_ns(baset_ns, fuzzt_ns, HRTIMER_MODE_REL, trsp); |
ae19aaaf PM |
112 | } |
113 | EXPORT_SYMBOL_GPL(torture_hrtimeout_us); | |
114 | ||
115 | /* | |
116 | * Schedule a high-resolution-timer sleep in milliseconds, with a 32-bit | |
117 | * microsecond (not millisecond!) random fuzz. | |
118 | */ | |
119 | int torture_hrtimeout_ms(u32 baset_ms, u32 fuzzt_us, struct torture_random_state *trsp) | |
120 | { | |
121 | ktime_t baset_ns = baset_ms * NSEC_PER_MSEC; | |
122 | u32 fuzzt_ns; | |
123 | ||
124 | if ((u32)~0U / NSEC_PER_USEC < fuzzt_us) | |
125 | fuzzt_ns = (u32)~0U; | |
126 | else | |
127 | fuzzt_ns = fuzzt_us * NSEC_PER_USEC; | |
a741deac | 128 | return torture_hrtimeout_ns(baset_ns, fuzzt_ns, HRTIMER_MODE_REL, trsp); |
ae19aaaf PM |
129 | } |
130 | EXPORT_SYMBOL_GPL(torture_hrtimeout_ms); | |
131 | ||
132 | /* | |
133 | * Schedule a high-resolution-timer sleep in jiffies, with an | |
134 | * implied one-jiffy random fuzz. This is intended to replace calls to | |
135 | * schedule_timeout_interruptible() and friends. | |
136 | */ | |
137 | int torture_hrtimeout_jiffies(u32 baset_j, struct torture_random_state *trsp) | |
138 | { | |
139 | ktime_t baset_ns = jiffies_to_nsecs(baset_j); | |
140 | ||
a741deac | 141 | return torture_hrtimeout_ns(baset_ns, jiffies_to_nsecs(1), HRTIMER_MODE_REL, trsp); |
ae19aaaf PM |
142 | } |
143 | EXPORT_SYMBOL_GPL(torture_hrtimeout_jiffies); | |
144 | ||
145 | /* | |
146 | * Schedule a high-resolution-timer sleep in milliseconds, with a 32-bit | |
147 | * millisecond (not second!) random fuzz. | |
148 | */ | |
149 | int torture_hrtimeout_s(u32 baset_s, u32 fuzzt_ms, struct torture_random_state *trsp) | |
150 | { | |
151 | ktime_t baset_ns = baset_s * NSEC_PER_SEC; | |
152 | u32 fuzzt_ns; | |
153 | ||
154 | if ((u32)~0U / NSEC_PER_MSEC < fuzzt_ms) | |
155 | fuzzt_ns = (u32)~0U; | |
156 | else | |
157 | fuzzt_ns = fuzzt_ms * NSEC_PER_MSEC; | |
a741deac | 158 | return torture_hrtimeout_ns(baset_ns, fuzzt_ns, HRTIMER_MODE_REL, trsp); |
ae19aaaf PM |
159 | } |
160 | EXPORT_SYMBOL_GPL(torture_hrtimeout_s); | |
161 | ||
2e9e8081 PM |
162 | #ifdef CONFIG_HOTPLUG_CPU |
163 | ||
164 | /* | |
165 | * Variables for online-offline handling. Only present if CPU hotplug | |
166 | * is enabled, otherwise does nothing. | |
167 | */ | |
168 | ||
169 | static struct task_struct *onoff_task; | |
170 | static long onoff_holdoff; | |
171 | static long onoff_interval; | |
3a6cb58f | 172 | static torture_ofl_func *onoff_f; |
2e9e8081 PM |
173 | static long n_offline_attempts; |
174 | static long n_offline_successes; | |
175 | static unsigned long sum_offline; | |
176 | static int min_offline = -1; | |
177 | static int max_offline; | |
178 | static long n_online_attempts; | |
179 | static long n_online_successes; | |
180 | static unsigned long sum_online; | |
181 | static int min_online = -1; | |
182 | static int max_online; | |
183 | ||
1afb95fe PM |
184 | static int torture_online_cpus = NR_CPUS; |
185 | ||
186 | /* | |
187 | * Some torture testing leverages confusion as to the number of online | |
188 | * CPUs. This function returns the torture-testing view of this number, | |
189 | * which allows torture tests to load-balance appropriately. | |
190 | */ | |
191 | int torture_num_online_cpus(void) | |
192 | { | |
193 | return READ_ONCE(torture_online_cpus); | |
194 | } | |
195 | EXPORT_SYMBOL_GPL(torture_num_online_cpus); | |
196 | ||
d95f5ba9 PM |
197 | /* |
198 | * Attempt to take a CPU offline. Return false if the CPU is already | |
199 | * offline or if it is not subject to CPU-hotplug operations. The | |
200 | * caller can detect other failures by looking at the statistics. | |
201 | */ | |
202 | bool torture_offline(int cpu, long *n_offl_attempts, long *n_offl_successes, | |
203 | unsigned long *sum_offl, int *min_offl, int *max_offl) | |
204 | { | |
205 | unsigned long delta; | |
206 | int ret; | |
a59ee765 | 207 | char *s; |
d95f5ba9 PM |
208 | unsigned long starttime; |
209 | ||
210 | if (!cpu_online(cpu) || !cpu_is_hotpluggable(cpu)) | |
211 | return false; | |
24aca4ae PM |
212 | if (num_online_cpus() <= 1) |
213 | return false; /* Can't offline the last CPU. */ | |
d95f5ba9 | 214 | |
90127d60 | 215 | if (verbose > 1) |
d95f5ba9 PM |
216 | pr_alert("%s" TORTURE_FLAG |
217 | "torture_onoff task: offlining %d\n", | |
218 | torture_type, cpu); | |
219 | starttime = jiffies; | |
220 | (*n_offl_attempts)++; | |
457bc8ed | 221 | ret = remove_cpu(cpu); |
d95f5ba9 | 222 | if (ret) { |
a59ee765 PM |
223 | s = ""; |
224 | if (!rcu_inkernel_boot_has_ended() && ret == -EBUSY) { | |
225 | // PCI probe frequently disables hotplug during boot. | |
226 | (*n_offl_attempts)--; | |
227 | s = " (-EBUSY forgiven during boot)"; | |
228 | } | |
d95f5ba9 PM |
229 | if (verbose) |
230 | pr_alert("%s" TORTURE_FLAG | |
a59ee765 PM |
231 | "torture_onoff task: offline %d failed%s: errno %d\n", |
232 | torture_type, cpu, s, ret); | |
d95f5ba9 | 233 | } else { |
90127d60 | 234 | if (verbose > 1) |
d95f5ba9 PM |
235 | pr_alert("%s" TORTURE_FLAG |
236 | "torture_onoff task: offlined %d\n", | |
237 | torture_type, cpu); | |
3a6cb58f PM |
238 | if (onoff_f) |
239 | onoff_f(); | |
d95f5ba9 PM |
240 | (*n_offl_successes)++; |
241 | delta = jiffies - starttime; | |
a2b2df20 | 242 | *sum_offl += delta; |
d95f5ba9 PM |
243 | if (*min_offl < 0) { |
244 | *min_offl = delta; | |
245 | *max_offl = delta; | |
246 | } | |
247 | if (*min_offl > delta) | |
248 | *min_offl = delta; | |
249 | if (*max_offl < delta) | |
250 | *max_offl = delta; | |
1afb95fe PM |
251 | WRITE_ONCE(torture_online_cpus, torture_online_cpus - 1); |
252 | WARN_ON_ONCE(torture_online_cpus <= 0); | |
d95f5ba9 PM |
253 | } |
254 | ||
255 | return true; | |
256 | } | |
257 | EXPORT_SYMBOL_GPL(torture_offline); | |
258 | ||
259 | /* | |
260 | * Attempt to bring a CPU online. Return false if the CPU is already | |
261 | * online or if it is not subject to CPU-hotplug operations. The | |
262 | * caller can detect other failures by looking at the statistics. | |
263 | */ | |
264 | bool torture_online(int cpu, long *n_onl_attempts, long *n_onl_successes, | |
265 | unsigned long *sum_onl, int *min_onl, int *max_onl) | |
266 | { | |
267 | unsigned long delta; | |
268 | int ret; | |
a59ee765 | 269 | char *s; |
d95f5ba9 PM |
270 | unsigned long starttime; |
271 | ||
272 | if (cpu_online(cpu) || !cpu_is_hotpluggable(cpu)) | |
273 | return false; | |
274 | ||
90127d60 | 275 | if (verbose > 1) |
d95f5ba9 PM |
276 | pr_alert("%s" TORTURE_FLAG |
277 | "torture_onoff task: onlining %d\n", | |
278 | torture_type, cpu); | |
279 | starttime = jiffies; | |
280 | (*n_onl_attempts)++; | |
457bc8ed | 281 | ret = add_cpu(cpu); |
d95f5ba9 | 282 | if (ret) { |
a59ee765 PM |
283 | s = ""; |
284 | if (!rcu_inkernel_boot_has_ended() && ret == -EBUSY) { | |
285 | // PCI probe frequently disables hotplug during boot. | |
286 | (*n_onl_attempts)--; | |
287 | s = " (-EBUSY forgiven during boot)"; | |
288 | } | |
d95f5ba9 PM |
289 | if (verbose) |
290 | pr_alert("%s" TORTURE_FLAG | |
a59ee765 PM |
291 | "torture_onoff task: online %d failed%s: errno %d\n", |
292 | torture_type, cpu, s, ret); | |
d95f5ba9 | 293 | } else { |
90127d60 | 294 | if (verbose > 1) |
d95f5ba9 PM |
295 | pr_alert("%s" TORTURE_FLAG |
296 | "torture_onoff task: onlined %d\n", | |
297 | torture_type, cpu); | |
298 | (*n_onl_successes)++; | |
299 | delta = jiffies - starttime; | |
300 | *sum_onl += delta; | |
301 | if (*min_onl < 0) { | |
302 | *min_onl = delta; | |
303 | *max_onl = delta; | |
304 | } | |
305 | if (*min_onl > delta) | |
306 | *min_onl = delta; | |
307 | if (*max_onl < delta) | |
308 | *max_onl = delta; | |
1afb95fe | 309 | WRITE_ONCE(torture_online_cpus, torture_online_cpus + 1); |
d95f5ba9 PM |
310 | } |
311 | ||
312 | return true; | |
313 | } | |
314 | EXPORT_SYMBOL_GPL(torture_online); | |
315 | ||
0b962c8f PM |
316 | /* |
317 | * Get everything online at the beginning and ends of tests. | |
318 | */ | |
319 | static void torture_online_all(char *phase) | |
320 | { | |
321 | int cpu; | |
322 | int ret; | |
323 | ||
324 | for_each_possible_cpu(cpu) { | |
325 | if (cpu_online(cpu)) | |
326 | continue; | |
327 | ret = add_cpu(cpu); | |
328 | if (ret && verbose) { | |
329 | pr_alert("%s" TORTURE_FLAG | |
330 | "%s: %s online %d: errno %d\n", | |
331 | __func__, phase, torture_type, cpu, ret); | |
332 | } | |
333 | } | |
334 | } | |
335 | ||
2e9e8081 PM |
336 | /* |
337 | * Execute random CPU-hotplug operations at the interval specified | |
338 | * by the onoff_interval. | |
339 | */ | |
340 | static int | |
341 | torture_onoff(void *arg) | |
342 | { | |
343 | int cpu; | |
2e9e8081 PM |
344 | int maxcpu = -1; |
345 | DEFINE_TORTURE_RANDOM(rand); | |
2e9e8081 PM |
346 | |
347 | VERBOSE_TOROUT_STRING("torture_onoff task started"); | |
348 | for_each_online_cpu(cpu) | |
349 | maxcpu = cpu; | |
350 | WARN_ON(maxcpu < 0); | |
0b962c8f | 351 | torture_online_all("Initial"); |
750db0f5 BF |
352 | if (maxcpu == 0) { |
353 | VERBOSE_TOROUT_STRING("Only one CPU, so CPU-hotplug testing is disabled"); | |
354 | goto stop; | |
355 | } | |
356 | ||
2e9e8081 PM |
357 | if (onoff_holdoff > 0) { |
358 | VERBOSE_TOROUT_STRING("torture_onoff begin holdoff"); | |
3f0c06e1 | 359 | torture_hrtimeout_jiffies(onoff_holdoff, &rand); |
2e9e8081 PM |
360 | VERBOSE_TOROUT_STRING("torture_onoff end holdoff"); |
361 | } | |
362 | while (!torture_must_stop()) { | |
8171d3e0 | 363 | if (disable_onoff_at_boot && !rcu_inkernel_boot_has_ended()) { |
3f0c06e1 | 364 | torture_hrtimeout_jiffies(HZ / 10, &rand); |
8171d3e0 PM |
365 | continue; |
366 | } | |
6cab60ce | 367 | cpu = torture_random(&rand) % (maxcpu + 1); |
d95f5ba9 PM |
368 | if (!torture_offline(cpu, |
369 | &n_offline_attempts, &n_offline_successes, | |
370 | &sum_offline, &min_offline, &max_offline)) | |
371 | torture_online(cpu, | |
372 | &n_online_attempts, &n_online_successes, | |
373 | &sum_online, &min_online, &max_online); | |
3f0c06e1 | 374 | torture_hrtimeout_jiffies(onoff_interval, &rand); |
2e9e8081 | 375 | } |
750db0f5 BF |
376 | |
377 | stop: | |
7fafaac5 | 378 | torture_kthread_stopping("torture_onoff"); |
0b962c8f | 379 | torture_online_all("Final"); |
2e9e8081 PM |
380 | return 0; |
381 | } | |
382 | ||
383 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ | |
384 | ||
385 | /* | |
386 | * Initiate online-offline handling. | |
387 | */ | |
3a6cb58f | 388 | int torture_onoff_init(long ooholdoff, long oointerval, torture_ofl_func *f) |
2e9e8081 | 389 | { |
47cf29b9 | 390 | #ifdef CONFIG_HOTPLUG_CPU |
2e9e8081 PM |
391 | onoff_holdoff = ooholdoff; |
392 | onoff_interval = oointerval; | |
3a6cb58f | 393 | onoff_f = f; |
2e9e8081 PM |
394 | if (onoff_interval <= 0) |
395 | return 0; | |
2a7d9688 PG |
396 | return torture_create_kthread(torture_onoff, NULL, onoff_task); |
397 | #else /* #ifdef CONFIG_HOTPLUG_CPU */ | |
398 | return 0; | |
399 | #endif /* #else #ifdef CONFIG_HOTPLUG_CPU */ | |
2e9e8081 PM |
400 | } |
401 | EXPORT_SYMBOL_GPL(torture_onoff_init); | |
402 | ||
403 | /* | |
404 | * Clean up after online/offline testing. | |
405 | */ | |
cc47ae08 | 406 | static void torture_onoff_cleanup(void) |
2e9e8081 PM |
407 | { |
408 | #ifdef CONFIG_HOTPLUG_CPU | |
409 | if (onoff_task == NULL) | |
410 | return; | |
411 | VERBOSE_TOROUT_STRING("Stopping torture_onoff task"); | |
412 | kthread_stop(onoff_task); | |
413 | onoff_task = NULL; | |
414 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ | |
415 | } | |
2e9e8081 PM |
416 | |
417 | /* | |
418 | * Print online/offline testing statistics. | |
419 | */ | |
eea203fe | 420 | void torture_onoff_stats(void) |
2e9e8081 PM |
421 | { |
422 | #ifdef CONFIG_HOTPLUG_CPU | |
eea203fe JP |
423 | pr_cont("onoff: %ld/%ld:%ld/%ld %d,%d:%d,%d %lu:%lu (HZ=%d) ", |
424 | n_online_successes, n_online_attempts, | |
425 | n_offline_successes, n_offline_attempts, | |
426 | min_online, max_online, | |
427 | min_offline, max_offline, | |
428 | sum_online, sum_offline, HZ); | |
2e9e8081 | 429 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ |
2e9e8081 PM |
430 | } |
431 | EXPORT_SYMBOL_GPL(torture_onoff_stats); | |
432 | ||
433 | /* | |
434 | * Were all the online/offline operations successful? | |
435 | */ | |
436 | bool torture_onoff_failures(void) | |
437 | { | |
438 | #ifdef CONFIG_HOTPLUG_CPU | |
439 | return n_online_successes != n_online_attempts || | |
440 | n_offline_successes != n_offline_attempts; | |
441 | #else /* #ifdef CONFIG_HOTPLUG_CPU */ | |
442 | return false; | |
443 | #endif /* #else #ifdef CONFIG_HOTPLUG_CPU */ | |
444 | } | |
445 | EXPORT_SYMBOL_GPL(torture_onoff_failures); | |
446 | ||
51b1130e PM |
447 | #define TORTURE_RANDOM_MULT 39916801 /* prime */ |
448 | #define TORTURE_RANDOM_ADD 479001701 /* prime */ | |
449 | #define TORTURE_RANDOM_REFRESH 10000 | |
450 | ||
451 | /* | |
452 | * Crude but fast random-number generator. Uses a linear congruential | |
453 | * generator, with occasional help from cpu_clock(). | |
454 | */ | |
455 | unsigned long | |
456 | torture_random(struct torture_random_state *trsp) | |
457 | { | |
458 | if (--trsp->trs_count < 0) { | |
95f93e97 | 459 | trsp->trs_state += (unsigned long)local_clock() + raw_smp_processor_id(); |
51b1130e PM |
460 | trsp->trs_count = TORTURE_RANDOM_REFRESH; |
461 | } | |
462 | trsp->trs_state = trsp->trs_state * TORTURE_RANDOM_MULT + | |
463 | TORTURE_RANDOM_ADD; | |
464 | return swahw32(trsp->trs_state); | |
465 | } | |
466 | EXPORT_SYMBOL_GPL(torture_random); | |
f67a3356 | 467 | |
3808dc9f PM |
468 | /* |
469 | * Variables for shuffling. The idea is to ensure that each CPU stays | |
470 | * idle for an extended period to test interactions with dyntick idle, | |
b564d62e | 471 | * as well as interactions with any per-CPU variables. |
3808dc9f PM |
472 | */ |
473 | struct shuffle_task { | |
474 | struct list_head st_l; | |
475 | struct task_struct *st_t; | |
476 | }; | |
477 | ||
478 | static long shuffle_interval; /* In jiffies. */ | |
479 | static struct task_struct *shuffler_task; | |
480 | static cpumask_var_t shuffle_tmp_mask; | |
481 | static int shuffle_idle_cpu; /* Force all torture tasks off this CPU */ | |
482 | static struct list_head shuffle_task_list = LIST_HEAD_INIT(shuffle_task_list); | |
483 | static DEFINE_MUTEX(shuffle_task_mutex); | |
484 | ||
485 | /* | |
486 | * Register a task to be shuffled. If there is no memory, just splat | |
487 | * and don't bother registering. | |
488 | */ | |
489 | void torture_shuffle_task_register(struct task_struct *tp) | |
490 | { | |
491 | struct shuffle_task *stp; | |
492 | ||
493 | if (WARN_ON_ONCE(tp == NULL)) | |
494 | return; | |
495 | stp = kmalloc(sizeof(*stp), GFP_KERNEL); | |
496 | if (WARN_ON_ONCE(stp == NULL)) | |
497 | return; | |
498 | stp->st_t = tp; | |
499 | mutex_lock(&shuffle_task_mutex); | |
500 | list_add(&stp->st_l, &shuffle_task_list); | |
501 | mutex_unlock(&shuffle_task_mutex); | |
502 | } | |
503 | EXPORT_SYMBOL_GPL(torture_shuffle_task_register); | |
504 | ||
505 | /* | |
506 | * Unregister all tasks, for example, at the end of the torture run. | |
507 | */ | |
508 | static void torture_shuffle_task_unregister_all(void) | |
509 | { | |
510 | struct shuffle_task *stp; | |
511 | struct shuffle_task *p; | |
512 | ||
513 | mutex_lock(&shuffle_task_mutex); | |
514 | list_for_each_entry_safe(stp, p, &shuffle_task_list, st_l) { | |
515 | list_del(&stp->st_l); | |
516 | kfree(stp); | |
517 | } | |
518 | mutex_unlock(&shuffle_task_mutex); | |
519 | } | |
520 | ||
521 | /* Shuffle tasks such that we allow shuffle_idle_cpu to become idle. | |
522 | * A special case is when shuffle_idle_cpu = -1, in which case we allow | |
523 | * the tasks to run on all CPUs. | |
524 | */ | |
d0b654e1 | 525 | static void torture_shuffle_tasks(struct torture_random_state *trp) |
3808dc9f PM |
526 | { |
527 | struct shuffle_task *stp; | |
528 | ||
529 | cpumask_setall(shuffle_tmp_mask); | |
ed4fa244 | 530 | cpus_read_lock(); |
3808dc9f PM |
531 | |
532 | /* No point in shuffling if there is only one online CPU (ex: UP) */ | |
533 | if (num_online_cpus() == 1) { | |
ed4fa244 | 534 | cpus_read_unlock(); |
3808dc9f PM |
535 | return; |
536 | } | |
537 | ||
538 | /* Advance to the next CPU. Upon overflow, don't idle any CPUs. */ | |
539 | shuffle_idle_cpu = cpumask_next(shuffle_idle_cpu, shuffle_tmp_mask); | |
540 | if (shuffle_idle_cpu >= nr_cpu_ids) | |
541 | shuffle_idle_cpu = -1; | |
5ed63b19 | 542 | else |
3808dc9f | 543 | cpumask_clear_cpu(shuffle_idle_cpu, shuffle_tmp_mask); |
3808dc9f PM |
544 | |
545 | mutex_lock(&shuffle_task_mutex); | |
e2a0b786 | 546 | list_for_each_entry(stp, &shuffle_task_list, st_l) { |
d0b654e1 | 547 | if (!random_shuffle || torture_random(trp) & 0x1) |
e2a0b786 CB |
548 | set_cpus_allowed_ptr(stp->st_t, shuffle_tmp_mask); |
549 | } | |
3808dc9f PM |
550 | mutex_unlock(&shuffle_task_mutex); |
551 | ||
ed4fa244 | 552 | cpus_read_unlock(); |
3808dc9f PM |
553 | } |
554 | ||
555 | /* Shuffle tasks across CPUs, with the intent of allowing each CPU in the | |
556 | * system to become idle at a time and cut off its timer ticks. This is meant | |
557 | * to test the support for such tickless idle CPU in RCU. | |
558 | */ | |
559 | static int torture_shuffle(void *arg) | |
560 | { | |
dea81dcf PM |
561 | DEFINE_TORTURE_RANDOM(rand); |
562 | ||
3808dc9f PM |
563 | VERBOSE_TOROUT_STRING("torture_shuffle task started"); |
564 | do { | |
dea81dcf | 565 | torture_hrtimeout_jiffies(shuffle_interval, &rand); |
d0b654e1 | 566 | torture_shuffle_tasks(&rand); |
3808dc9f PM |
567 | torture_shutdown_absorb("torture_shuffle"); |
568 | } while (!torture_must_stop()); | |
7fafaac5 | 569 | torture_kthread_stopping("torture_shuffle"); |
3808dc9f PM |
570 | return 0; |
571 | } | |
572 | ||
573 | /* | |
574 | * Start the shuffler, with shuffint in jiffies. | |
575 | */ | |
576 | int torture_shuffle_init(long shuffint) | |
577 | { | |
3808dc9f PM |
578 | shuffle_interval = shuffint; |
579 | ||
580 | shuffle_idle_cpu = -1; | |
581 | ||
582 | if (!alloc_cpumask_var(&shuffle_tmp_mask, GFP_KERNEL)) { | |
81faa4f6 | 583 | TOROUT_ERRSTRING("Failed to alloc mask"); |
3808dc9f PM |
584 | return -ENOMEM; |
585 | } | |
586 | ||
587 | /* Create the shuffler thread */ | |
47cf29b9 | 588 | return torture_create_kthread(torture_shuffle, NULL, shuffler_task); |
3808dc9f PM |
589 | } |
590 | EXPORT_SYMBOL_GPL(torture_shuffle_init); | |
591 | ||
592 | /* | |
593 | * Stop the shuffling. | |
594 | */ | |
cc47ae08 | 595 | static void torture_shuffle_cleanup(void) |
3808dc9f PM |
596 | { |
597 | torture_shuffle_task_unregister_all(); | |
598 | if (shuffler_task) { | |
599 | VERBOSE_TOROUT_STRING("Stopping torture_shuffle task"); | |
600 | kthread_stop(shuffler_task); | |
601 | free_cpumask_var(shuffle_tmp_mask); | |
602 | } | |
603 | shuffler_task = NULL; | |
604 | } | |
3808dc9f | 605 | |
e991dbc0 PM |
606 | /* |
607 | * Variables for auto-shutdown. This allows "lights out" torture runs | |
608 | * to be fully scripted. | |
609 | */ | |
e991dbc0 | 610 | static struct task_struct *shutdown_task; |
31257c3c | 611 | static ktime_t shutdown_time; /* time to system shutdown. */ |
e991dbc0 PM |
612 | static void (*torture_shutdown_hook)(void); |
613 | ||
f67a3356 PM |
614 | /* |
615 | * Absorb kthreads into a kernel function that won't return, so that | |
616 | * they won't ever access module text or data again. | |
617 | */ | |
618 | void torture_shutdown_absorb(const char *title) | |
619 | { | |
7d0ae808 | 620 | while (READ_ONCE(fullstop) == FULLSTOP_SHUTDOWN) { |
4622b487 PM |
621 | pr_notice("torture thread %s parking due to system shutdown\n", |
622 | title); | |
f67a3356 PM |
623 | schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT); |
624 | } | |
625 | } | |
626 | EXPORT_SYMBOL_GPL(torture_shutdown_absorb); | |
b5daa8f3 | 627 | |
e991dbc0 PM |
628 | /* |
629 | * Cause the torture test to shutdown the system after the test has | |
630 | * run for the time specified by the shutdown_secs parameter. | |
631 | */ | |
632 | static int torture_shutdown(void *arg) | |
633 | { | |
31257c3c | 634 | ktime_t ktime_snap; |
e991dbc0 PM |
635 | |
636 | VERBOSE_TOROUT_STRING("torture_shutdown task started"); | |
31257c3c PM |
637 | ktime_snap = ktime_get(); |
638 | while (ktime_before(ktime_snap, shutdown_time) && | |
e991dbc0 | 639 | !torture_must_stop()) { |
e991dbc0 PM |
640 | if (verbose) |
641 | pr_alert("%s" TORTURE_FLAG | |
31257c3c PM |
642 | "torture_shutdown task: %llu ms remaining\n", |
643 | torture_type, | |
644 | ktime_ms_delta(shutdown_time, ktime_snap)); | |
645 | set_current_state(TASK_INTERRUPTIBLE); | |
646 | schedule_hrtimeout(&shutdown_time, HRTIMER_MODE_ABS); | |
647 | ktime_snap = ktime_get(); | |
e991dbc0 PM |
648 | } |
649 | if (torture_must_stop()) { | |
7fafaac5 | 650 | torture_kthread_stopping("torture_shutdown"); |
e991dbc0 PM |
651 | return 0; |
652 | } | |
653 | ||
654 | /* OK, shut down the system. */ | |
655 | ||
656 | VERBOSE_TOROUT_STRING("torture_shutdown task shutting down system"); | |
657 | shutdown_task = NULL; /* Avoid self-kill deadlock. */ | |
f881825a PM |
658 | if (torture_shutdown_hook) |
659 | torture_shutdown_hook(); | |
660 | else | |
661 | VERBOSE_TOROUT_STRING("No torture_shutdown_hook(), skipping."); | |
2102ad29 PM |
662 | if (ftrace_dump_at_shutdown) |
663 | rcu_ftrace_dump(DUMP_ALL); | |
e991dbc0 PM |
664 | kernel_power_off(); /* Shut down the system. */ |
665 | return 0; | |
666 | } | |
667 | ||
668 | /* | |
669 | * Start up the shutdown task. | |
670 | */ | |
671 | int torture_shutdown_init(int ssecs, void (*cleanup)(void)) | |
672 | { | |
e991dbc0 | 673 | torture_shutdown_hook = cleanup; |
31257c3c PM |
674 | if (ssecs > 0) { |
675 | shutdown_time = ktime_add(ktime_get(), ktime_set(ssecs, 0)); | |
2a7d9688 | 676 | return torture_create_kthread(torture_shutdown, NULL, |
d0b654e1 | 677 | shutdown_task); |
e991dbc0 | 678 | } |
2a7d9688 | 679 | return 0; |
e991dbc0 PM |
680 | } |
681 | EXPORT_SYMBOL_GPL(torture_shutdown_init); | |
682 | ||
4622b487 PM |
683 | /* |
684 | * Detect and respond to a system shutdown. | |
685 | */ | |
686 | static int torture_shutdown_notify(struct notifier_block *unused1, | |
687 | unsigned long unused2, void *unused3) | |
688 | { | |
689 | mutex_lock(&fullstop_mutex); | |
7d0ae808 | 690 | if (READ_ONCE(fullstop) == FULLSTOP_DONTSTOP) { |
fac480ef | 691 | VERBOSE_TOROUT_STRING("Unscheduled system shutdown detected"); |
7d0ae808 | 692 | WRITE_ONCE(fullstop, FULLSTOP_SHUTDOWN); |
fac480ef | 693 | } else { |
4622b487 | 694 | pr_warn("Concurrent rmmod and shutdown illegal!\n"); |
fac480ef | 695 | } |
4622b487 PM |
696 | mutex_unlock(&fullstop_mutex); |
697 | return NOTIFY_DONE; | |
698 | } | |
699 | ||
700 | static struct notifier_block torture_shutdown_nb = { | |
701 | .notifier_call = torture_shutdown_notify, | |
702 | }; | |
703 | ||
bfefc73a PM |
704 | /* |
705 | * Shut down the shutdown task. Say what??? Heh! This can happen if | |
706 | * the torture module gets an rmmod before the shutdown time arrives. ;-) | |
707 | */ | |
708 | static void torture_shutdown_cleanup(void) | |
709 | { | |
710 | unregister_reboot_notifier(&torture_shutdown_nb); | |
711 | if (shutdown_task != NULL) { | |
712 | VERBOSE_TOROUT_STRING("Stopping torture_shutdown task"); | |
713 | kthread_stop(shutdown_task); | |
714 | } | |
715 | shutdown_task = NULL; | |
716 | } | |
717 | ||
628edaa5 PM |
718 | /* |
719 | * Variables for stuttering, which means to periodically pause and | |
720 | * restart testing in order to catch bugs that appear when load is | |
721 | * suddenly applied to or removed from the system. | |
722 | */ | |
723 | static struct task_struct *stutter_task; | |
cca42bd8 | 724 | static ktime_t stutter_till_abs_time; |
628edaa5 | 725 | static int stutter; |
ff3bf92d | 726 | static int stutter_gap; |
628edaa5 PM |
727 | |
728 | /* | |
729 | * Block until the stutter interval ends. This must be called periodically | |
730 | * by all running kthreads that need to be subject to stuttering. | |
731 | */ | |
474e59b4 | 732 | bool stutter_wait(const char *title) |
628edaa5 | 733 | { |
e8516c64 | 734 | bool ret = false; |
cca42bd8 | 735 | ktime_t till_ns; |
4ced3314 | 736 | |
cee43939 | 737 | cond_resched_tasks_rcu_qs(); |
cca42bd8 JFG |
738 | till_ns = READ_ONCE(stutter_till_abs_time); |
739 | if (till_ns && ktime_before(ktime_get(), till_ns)) { | |
740 | torture_hrtimeout_ns(till_ns, 0, HRTIMER_MODE_ABS, NULL); | |
741 | ret = true; | |
628edaa5 | 742 | } |
cca42bd8 | 743 | torture_shutdown_absorb(title); |
e8516c64 | 744 | return ret; |
628edaa5 PM |
745 | } |
746 | EXPORT_SYMBOL_GPL(stutter_wait); | |
747 | ||
748 | /* | |
749 | * Cause the torture test to "stutter", starting and stopping all | |
750 | * threads periodically. | |
751 | */ | |
752 | static int torture_stutter(void *arg) | |
753 | { | |
cca42bd8 | 754 | ktime_t till_ns; |
e8516c64 | 755 | |
628edaa5 PM |
756 | VERBOSE_TOROUT_STRING("torture_stutter task started"); |
757 | do { | |
4ced3314 | 758 | if (!torture_must_stop() && stutter > 1) { |
cca42bd8 JFG |
759 | till_ns = ktime_add_ns(ktime_get(), |
760 | jiffies_to_nsecs(stutter)); | |
761 | WRITE_ONCE(stutter_till_abs_time, till_ns); | |
762 | torture_hrtimeout_jiffies(stutter - 1, NULL); | |
628edaa5 PM |
763 | } |
764 | if (!torture_must_stop()) | |
ed24affa | 765 | torture_hrtimeout_jiffies(stutter_gap, NULL); |
628edaa5 PM |
766 | torture_shutdown_absorb("torture_stutter"); |
767 | } while (!torture_must_stop()); | |
7fafaac5 | 768 | torture_kthread_stopping("torture_stutter"); |
628edaa5 PM |
769 | return 0; |
770 | } | |
771 | ||
772 | /* | |
773 | * Initialize and kick off the torture_stutter kthread. | |
774 | */ | |
ff3bf92d | 775 | int torture_stutter_init(const int s, const int sgap) |
628edaa5 | 776 | { |
628edaa5 | 777 | stutter = s; |
ff3bf92d | 778 | stutter_gap = sgap; |
2a7d9688 | 779 | return torture_create_kthread(torture_stutter, NULL, stutter_task); |
628edaa5 PM |
780 | } |
781 | EXPORT_SYMBOL_GPL(torture_stutter_init); | |
782 | ||
783 | /* | |
784 | * Cleanup after the torture_stutter kthread. | |
785 | */ | |
bfefc73a | 786 | static void torture_stutter_cleanup(void) |
628edaa5 PM |
787 | { |
788 | if (!stutter_task) | |
789 | return; | |
790 | VERBOSE_TOROUT_STRING("Stopping torture_stutter task"); | |
791 | kthread_stop(stutter_task); | |
792 | stutter_task = NULL; | |
793 | } | |
628edaa5 | 794 | |
394473d8 PM |
795 | static void |
796 | torture_print_module_parms(void) | |
797 | { | |
798 | pr_alert("torture module --- %s: disable_onoff_at_boot=%d ftrace_dump_at_shutdown=%d verbose_sleep_frequency=%d verbose_sleep_duration=%d random_shuffle=%d\n", | |
799 | torture_type, disable_onoff_at_boot, ftrace_dump_at_shutdown, verbose_sleep_frequency, verbose_sleep_duration, random_shuffle); | |
800 | } | |
801 | ||
b5daa8f3 PM |
802 | /* |
803 | * Initialize torture module. Please note that this is -not- invoked via | |
804 | * the usual module_init() mechanism, but rather by an explicit call from | |
805 | * the client torture module. This call must be paired with a later | |
806 | * torture_init_end(). | |
628edaa5 PM |
807 | * |
808 | * The runnable parameter points to a flag that controls whether or not | |
809 | * the test is currently runnable. If there is no such flag, pass in NULL. | |
b5daa8f3 | 810 | */ |
90127d60 | 811 | bool torture_init_begin(char *ttype, int v) |
b5daa8f3 PM |
812 | { |
813 | mutex_lock(&fullstop_mutex); | |
5228084e | 814 | if (torture_type != NULL) { |
4ac9de07 SZ |
815 | pr_alert("%s: Refusing %s init: %s running.\n", |
816 | __func__, ttype, torture_type); | |
817 | pr_alert("%s: One torture test at a time!\n", __func__); | |
5228084e PM |
818 | mutex_unlock(&fullstop_mutex); |
819 | return false; | |
820 | } | |
b5daa8f3 PM |
821 | torture_type = ttype; |
822 | verbose = v; | |
36970bb9 | 823 | fullstop = FULLSTOP_DONTSTOP; |
394473d8 | 824 | torture_print_module_parms(); |
5228084e | 825 | return true; |
b5daa8f3 PM |
826 | } |
827 | EXPORT_SYMBOL_GPL(torture_init_begin); | |
828 | ||
829 | /* | |
830 | * Tell the torture module that initialization is complete. | |
831 | */ | |
2b3f8ffe | 832 | void torture_init_end(void) |
b5daa8f3 PM |
833 | { |
834 | mutex_unlock(&fullstop_mutex); | |
4622b487 | 835 | register_reboot_notifier(&torture_shutdown_nb); |
b5daa8f3 PM |
836 | } |
837 | EXPORT_SYMBOL_GPL(torture_init_end); | |
cc47ae08 PM |
838 | |
839 | /* | |
840 | * Clean up torture module. Please note that this is -not- invoked via | |
841 | * the usual module_exit() mechanism, but rather by an explicit call from | |
842 | * the client torture module. Returns true if a race with system shutdown | |
bfefc73a PM |
843 | * is detected, otherwise, all kthreads started by functions in this file |
844 | * will be shut down. | |
cc47ae08 PM |
845 | * |
846 | * This must be called before the caller starts shutting down its own | |
847 | * kthreads. | |
d36a7a0d DB |
848 | * |
849 | * Both torture_cleanup_begin() and torture_cleanup_end() must be paired, | |
850 | * in order to correctly perform the cleanup. They are separated because | |
851 | * threads can still need to reference the torture_type type, thus nullify | |
852 | * only after completing all other relevant calls. | |
cc47ae08 | 853 | */ |
d36a7a0d | 854 | bool torture_cleanup_begin(void) |
cc47ae08 PM |
855 | { |
856 | mutex_lock(&fullstop_mutex); | |
7d0ae808 | 857 | if (READ_ONCE(fullstop) == FULLSTOP_SHUTDOWN) { |
cc47ae08 PM |
858 | pr_warn("Concurrent rmmod and shutdown illegal!\n"); |
859 | mutex_unlock(&fullstop_mutex); | |
860 | schedule_timeout_uninterruptible(10); | |
861 | return true; | |
862 | } | |
7d0ae808 | 863 | WRITE_ONCE(fullstop, FULLSTOP_RMMOD); |
cc47ae08 | 864 | mutex_unlock(&fullstop_mutex); |
bfefc73a | 865 | torture_shutdown_cleanup(); |
cc47ae08 | 866 | torture_shuffle_cleanup(); |
bfefc73a | 867 | torture_stutter_cleanup(); |
cc47ae08 | 868 | torture_onoff_cleanup(); |
d36a7a0d DB |
869 | return false; |
870 | } | |
871 | EXPORT_SYMBOL_GPL(torture_cleanup_begin); | |
872 | ||
873 | void torture_cleanup_end(void) | |
874 | { | |
5228084e PM |
875 | mutex_lock(&fullstop_mutex); |
876 | torture_type = NULL; | |
877 | mutex_unlock(&fullstop_mutex); | |
cc47ae08 | 878 | } |
d36a7a0d | 879 | EXPORT_SYMBOL_GPL(torture_cleanup_end); |
36970bb9 PM |
880 | |
881 | /* | |
882 | * Is it time for the current torture test to stop? | |
883 | */ | |
884 | bool torture_must_stop(void) | |
885 | { | |
886 | return torture_must_stop_irq() || kthread_should_stop(); | |
887 | } | |
888 | EXPORT_SYMBOL_GPL(torture_must_stop); | |
889 | ||
890 | /* | |
891 | * Is it time for the current torture test to stop? This is the irq-safe | |
892 | * version, hence no check for kthread_should_stop(). | |
893 | */ | |
894 | bool torture_must_stop_irq(void) | |
895 | { | |
7d0ae808 | 896 | return READ_ONCE(fullstop) != FULLSTOP_DONTSTOP; |
36970bb9 PM |
897 | } |
898 | EXPORT_SYMBOL_GPL(torture_must_stop_irq); | |
7fafaac5 PM |
899 | |
900 | /* | |
901 | * Each kthread must wait for kthread_should_stop() before returning from | |
902 | * its top-level function, otherwise segfaults ensue. This function | |
903 | * prints a "stopping" message and waits for kthread_should_stop(), and | |
904 | * should be called from all torture kthreads immediately prior to | |
905 | * returning. | |
906 | */ | |
907 | void torture_kthread_stopping(char *title) | |
908 | { | |
0d6821d5 PM |
909 | char buf[128]; |
910 | ||
2b4a7f20 | 911 | snprintf(buf, sizeof(buf), "%s is stopping", title); |
0d6821d5 | 912 | VERBOSE_TOROUT_STRING(buf); |
7fafaac5 PM |
913 | while (!kthread_should_stop()) { |
914 | torture_shutdown_absorb(title); | |
d52d3a2b | 915 | schedule_timeout_uninterruptible(HZ / 20); |
7fafaac5 PM |
916 | } |
917 | } | |
918 | EXPORT_SYMBOL_GPL(torture_kthread_stopping); | |
47cf29b9 PM |
919 | |
920 | /* | |
921 | * Create a generic torture kthread that is immediately runnable. If you | |
922 | * need the kthread to be stopped so that you can do something to it before | |
923 | * it starts, you will need to open-code your own. | |
924 | */ | |
925 | int _torture_create_kthread(int (*fn)(void *arg), void *arg, char *s, char *m, | |
67d5404d | 926 | char *f, struct task_struct **tp, void (*cbf)(struct task_struct *tp)) |
47cf29b9 PM |
927 | { |
928 | int ret = 0; | |
929 | ||
930 | VERBOSE_TOROUT_STRING(m); | |
6b8646a9 | 931 | *tp = kthread_create(fn, arg, "%s", s); |
47cf29b9 PM |
932 | if (IS_ERR(*tp)) { |
933 | ret = PTR_ERR(*tp); | |
81faa4f6 | 934 | TOROUT_ERRSTRING(f); |
47cf29b9 | 935 | *tp = NULL; |
6b8646a9 | 936 | return ret; |
47cf29b9 | 937 | } |
67d5404d PM |
938 | |
939 | if (cbf) | |
940 | cbf(*tp); | |
941 | ||
6b8646a9 | 942 | wake_up_process(*tp); // Process is sleeping, so ordering provided. |
47cf29b9 PM |
943 | torture_shuffle_task_register(*tp); |
944 | return ret; | |
945 | } | |
946 | EXPORT_SYMBOL_GPL(_torture_create_kthread); | |
9c029b86 PM |
947 | |
948 | /* | |
949 | * Stop a generic kthread, emitting a message. | |
950 | */ | |
951 | void _torture_stop_kthread(char *m, struct task_struct **tp) | |
952 | { | |
953 | if (*tp == NULL) | |
954 | return; | |
955 | VERBOSE_TOROUT_STRING(m); | |
956 | kthread_stop(*tp); | |
957 | *tp = NULL; | |
958 | } | |
959 | EXPORT_SYMBOL_GPL(_torture_stop_kthread); |