~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/kernel/torture.c

Version: ~ [ linux-5.11-rc3 ] ~ [ linux-5.10.7 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.89 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.167 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.215 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.251 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.251 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.85 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  * Common functions for in-kernel torture tests.
  3  *
  4  * This program is free software; you can redistribute it and/or modify
  5  * it under the terms of the GNU General Public License as published by
  6  * the Free Software Foundation; either version 2 of the License, or
  7  * (at your option) any later version.
  8  *
  9  * This program is distributed in the hope that it will be useful,
 10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
 11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 12  * GNU General Public License for more details.
 13  *
 14  * You should have received a copy of the GNU General Public License
 15  * along with this program; if not, you can access it online at
 16  * http://www.gnu.org/licenses/gpl-2.0.html.
 17  *
 18  * Copyright (C) IBM Corporation, 2014
 19  *
 20  * Author: Paul E. McKenney <paulmck@us.ibm.com>
 21  *      Based on kernel/rcu/torture.c.
 22  */
 23 #include <linux/types.h>
 24 #include <linux/kernel.h>
 25 #include <linux/init.h>
 26 #include <linux/module.h>
 27 #include <linux/kthread.h>
 28 #include <linux/err.h>
 29 #include <linux/spinlock.h>
 30 #include <linux/smp.h>
 31 #include <linux/interrupt.h>
 32 #include <linux/sched.h>
 33 #include <linux/atomic.h>
 34 #include <linux/bitops.h>
 35 #include <linux/completion.h>
 36 #include <linux/moduleparam.h>
 37 #include <linux/percpu.h>
 38 #include <linux/notifier.h>
 39 #include <linux/reboot.h>
 40 #include <linux/freezer.h>
 41 #include <linux/cpu.h>
 42 #include <linux/delay.h>
 43 #include <linux/stat.h>
 44 #include <linux/slab.h>
 45 #include <linux/trace_clock.h>
 46 #include <asm/byteorder.h>
 47 #include <linux/torture.h>
 48 
 49 MODULE_LICENSE("GPL");
 50 MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com>");
 51 
 52 static char *torture_type;
 53 static bool verbose;
 54 
 55 /* Mediate rmmod and system shutdown.  Concurrent rmmod & shutdown illegal! */
 56 #define FULLSTOP_DONTSTOP 0     /* Normal operation. */
 57 #define FULLSTOP_SHUTDOWN 1     /* System shutdown with torture running. */
 58 #define FULLSTOP_RMMOD    2     /* Normal rmmod of torture. */
 59 static int fullstop = FULLSTOP_RMMOD;
 60 static DEFINE_MUTEX(fullstop_mutex);
 61 static int *torture_runnable;
 62 
 63 #ifdef CONFIG_HOTPLUG_CPU
 64 
 65 /*
 66  * Variables for online-offline handling.  Only present if CPU hotplug
 67  * is enabled, otherwise does nothing.
 68  */
 69 
 70 static struct task_struct *onoff_task;
 71 static long onoff_holdoff;
 72 static long onoff_interval;
 73 static long n_offline_attempts;
 74 static long n_offline_successes;
 75 static unsigned long sum_offline;
 76 static int min_offline = -1;
 77 static int max_offline;
 78 static long n_online_attempts;
 79 static long n_online_successes;
 80 static unsigned long sum_online;
 81 static int min_online = -1;
 82 static int max_online;
 83 
 84 /*
 85  * Execute random CPU-hotplug operations at the interval specified
 86  * by the onoff_interval.
 87  */
 88 static int
 89 torture_onoff(void *arg)
 90 {
 91         int cpu;
 92         unsigned long delta;
 93         int maxcpu = -1;
 94         DEFINE_TORTURE_RANDOM(rand);
 95         int ret;
 96         unsigned long starttime;
 97 
 98         VERBOSE_TOROUT_STRING("torture_onoff task started");
 99         for_each_online_cpu(cpu)
100                 maxcpu = cpu;
101         WARN_ON(maxcpu < 0);
102         if (onoff_holdoff > 0) {
103                 VERBOSE_TOROUT_STRING("torture_onoff begin holdoff");
104                 schedule_timeout_interruptible(onoff_holdoff);
105                 VERBOSE_TOROUT_STRING("torture_onoff end holdoff");
106         }
107         while (!torture_must_stop()) {
108                 cpu = (torture_random(&rand) >> 4) % (maxcpu + 1);
109                 if (cpu_online(cpu) && cpu_is_hotpluggable(cpu)) {
110                         if (verbose)
111                                 pr_alert("%s" TORTURE_FLAG
112                                          "torture_onoff task: offlining %d\n",
113                                          torture_type, cpu);
114                         starttime = jiffies;
115                         n_offline_attempts++;
116                         ret = cpu_down(cpu);
117                         if (ret) {
118                                 if (verbose)
119                                         pr_alert("%s" TORTURE_FLAG
120                                                  "torture_onoff task: offline %d failed: errno %d\n",
121                                                  torture_type, cpu, ret);
122                         } else {
123                                 if (verbose)
124                                         pr_alert("%s" TORTURE_FLAG
125                                                  "torture_onoff task: offlined %d\n",
126                                                  torture_type, cpu);
127                                 n_offline_successes++;
128                                 delta = jiffies - starttime;
129                                 sum_offline += delta;
130                                 if (min_offline < 0) {
131                                         min_offline = delta;
132                                         max_offline = delta;
133                                 }
134                                 if (min_offline > delta)
135                                         min_offline = delta;
136                                 if (max_offline < delta)
137                                         max_offline = delta;
138                         }
139                 } else if (cpu_is_hotpluggable(cpu)) {
140                         if (verbose)
141                                 pr_alert("%s" TORTURE_FLAG
142                                          "torture_onoff task: onlining %d\n",
143                                          torture_type, cpu);
144                         starttime = jiffies;
145                         n_online_attempts++;
146                         ret = cpu_up(cpu);
147                         if (ret) {
148                                 if (verbose)
149                                         pr_alert("%s" TORTURE_FLAG
150                                                  "torture_onoff task: online %d failed: errno %d\n",
151                                                  torture_type, cpu, ret);
152                         } else {
153                                 if (verbose)
154                                         pr_alert("%s" TORTURE_FLAG
155                                                  "torture_onoff task: onlined %d\n",
156                                                  torture_type, cpu);
157                                 n_online_successes++;
158                                 delta = jiffies - starttime;
159                                 sum_online += delta;
160                                 if (min_online < 0) {
161                                         min_online = delta;
162                                         max_online = delta;
163                                 }
164                                 if (min_online > delta)
165                                         min_online = delta;
166                                 if (max_online < delta)
167                                         max_online = delta;
168                         }
169                 }
170                 schedule_timeout_interruptible(onoff_interval);
171         }
172         torture_kthread_stopping("torture_onoff");
173         return 0;
174 }
175 
176 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
177 
178 /*
179  * Initiate online-offline handling.
180  */
181 int torture_onoff_init(long ooholdoff, long oointerval)
182 {
183         int ret = 0;
184 
185 #ifdef CONFIG_HOTPLUG_CPU
186         onoff_holdoff = ooholdoff;
187         onoff_interval = oointerval;
188         if (onoff_interval <= 0)
189                 return 0;
190         ret = torture_create_kthread(torture_onoff, NULL, onoff_task);
191 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
192         return ret;
193 }
194 EXPORT_SYMBOL_GPL(torture_onoff_init);
195 
196 /*
197  * Clean up after online/offline testing.
198  */
199 static void torture_onoff_cleanup(void)
200 {
201 #ifdef CONFIG_HOTPLUG_CPU
202         if (onoff_task == NULL)
203                 return;
204         VERBOSE_TOROUT_STRING("Stopping torture_onoff task");
205         kthread_stop(onoff_task);
206         onoff_task = NULL;
207 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
208 }
209 EXPORT_SYMBOL_GPL(torture_onoff_cleanup);
210 
211 /*
212  * Print online/offline testing statistics.
213  */
214 char *torture_onoff_stats(char *page)
215 {
216 #ifdef CONFIG_HOTPLUG_CPU
217         page += sprintf(page,
218                        "onoff: %ld/%ld:%ld/%ld %d,%d:%d,%d %lu:%lu (HZ=%d) ",
219                        n_online_successes, n_online_attempts,
220                        n_offline_successes, n_offline_attempts,
221                        min_online, max_online,
222                        min_offline, max_offline,
223                        sum_online, sum_offline, HZ);
224 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
225         return page;
226 }
227 EXPORT_SYMBOL_GPL(torture_onoff_stats);
228 
229 /*
230  * Were all the online/offline operations successful?
231  */
232 bool torture_onoff_failures(void)
233 {
234 #ifdef CONFIG_HOTPLUG_CPU
235         return n_online_successes != n_online_attempts ||
236                n_offline_successes != n_offline_attempts;
237 #else /* #ifdef CONFIG_HOTPLUG_CPU */
238         return false;
239 #endif /* #else #ifdef CONFIG_HOTPLUG_CPU */
240 }
241 EXPORT_SYMBOL_GPL(torture_onoff_failures);
242 
243 #define TORTURE_RANDOM_MULT     39916801  /* prime */
244 #define TORTURE_RANDOM_ADD      479001701 /* prime */
245 #define TORTURE_RANDOM_REFRESH  10000
246 
247 /*
248  * Crude but fast random-number generator.  Uses a linear congruential
249  * generator, with occasional help from cpu_clock().
250  */
251 unsigned long
252 torture_random(struct torture_random_state *trsp)
253 {
254         if (--trsp->trs_count < 0) {
255                 trsp->trs_state += (unsigned long)local_clock();
256                 trsp->trs_count = TORTURE_RANDOM_REFRESH;
257         }
258         trsp->trs_state = trsp->trs_state * TORTURE_RANDOM_MULT +
259                 TORTURE_RANDOM_ADD;
260         return swahw32(trsp->trs_state);
261 }
262 EXPORT_SYMBOL_GPL(torture_random);
263 
264 /*
265  * Variables for shuffling.  The idea is to ensure that each CPU stays
266  * idle for an extended period to test interactions with dyntick idle,
267  * as well as interactions with any per-CPU varibles.
268  */
269 struct shuffle_task {
270         struct list_head st_l;
271         struct task_struct *st_t;
272 };
273 
274 static long shuffle_interval;   /* In jiffies. */
275 static struct task_struct *shuffler_task;
276 static cpumask_var_t shuffle_tmp_mask;
277 static int shuffle_idle_cpu;    /* Force all torture tasks off this CPU */
278 static struct list_head shuffle_task_list = LIST_HEAD_INIT(shuffle_task_list);
279 static DEFINE_MUTEX(shuffle_task_mutex);
280 
281 /*
282  * Register a task to be shuffled.  If there is no memory, just splat
283  * and don't bother registering.
284  */
285 void torture_shuffle_task_register(struct task_struct *tp)
286 {
287         struct shuffle_task *stp;
288 
289         if (WARN_ON_ONCE(tp == NULL))
290                 return;
291         stp = kmalloc(sizeof(*stp), GFP_KERNEL);
292         if (WARN_ON_ONCE(stp == NULL))
293                 return;
294         stp->st_t = tp;
295         mutex_lock(&shuffle_task_mutex);
296         list_add(&stp->st_l, &shuffle_task_list);
297         mutex_unlock(&shuffle_task_mutex);
298 }
299 EXPORT_SYMBOL_GPL(torture_shuffle_task_register);
300 
301 /*
302  * Unregister all tasks, for example, at the end of the torture run.
303  */
304 static void torture_shuffle_task_unregister_all(void)
305 {
306         struct shuffle_task *stp;
307         struct shuffle_task *p;
308 
309         mutex_lock(&shuffle_task_mutex);
310         list_for_each_entry_safe(stp, p, &shuffle_task_list, st_l) {
311                 list_del(&stp->st_l);
312                 kfree(stp);
313         }
314         mutex_unlock(&shuffle_task_mutex);
315 }
316 
317 /* Shuffle tasks such that we allow shuffle_idle_cpu to become idle.
318  * A special case is when shuffle_idle_cpu = -1, in which case we allow
319  * the tasks to run on all CPUs.
320  */
321 static void torture_shuffle_tasks(void)
322 {
323         struct shuffle_task *stp;
324 
325         cpumask_setall(shuffle_tmp_mask);
326         get_online_cpus();
327 
328         /* No point in shuffling if there is only one online CPU (ex: UP) */
329         if (num_online_cpus() == 1) {
330                 put_online_cpus();
331                 return;
332         }
333 
334         /* Advance to the next CPU.  Upon overflow, don't idle any CPUs. */
335         shuffle_idle_cpu = cpumask_next(shuffle_idle_cpu, shuffle_tmp_mask);
336         if (shuffle_idle_cpu >= nr_cpu_ids)
337                 shuffle_idle_cpu = -1;
338         if (shuffle_idle_cpu != -1) {
339                 cpumask_clear_cpu(shuffle_idle_cpu, shuffle_tmp_mask);
340                 if (cpumask_empty(shuffle_tmp_mask)) {
341                         put_online_cpus();
342                         return;
343                 }
344         }
345 
346         mutex_lock(&shuffle_task_mutex);
347         list_for_each_entry(stp, &shuffle_task_list, st_l)
348                 set_cpus_allowed_ptr(stp->st_t, shuffle_tmp_mask);
349         mutex_unlock(&shuffle_task_mutex);
350 
351         put_online_cpus();
352 }
353 
354 /* Shuffle tasks across CPUs, with the intent of allowing each CPU in the
355  * system to become idle at a time and cut off its timer ticks. This is meant
356  * to test the support for such tickless idle CPU in RCU.
357  */
358 static int torture_shuffle(void *arg)
359 {
360         VERBOSE_TOROUT_STRING("torture_shuffle task started");
361         do {
362                 schedule_timeout_interruptible(shuffle_interval);
363                 torture_shuffle_tasks();
364                 torture_shutdown_absorb("torture_shuffle");
365         } while (!torture_must_stop());
366         torture_kthread_stopping("torture_shuffle");
367         return 0;
368 }
369 
370 /*
371  * Start the shuffler, with shuffint in jiffies.
372  */
373 int torture_shuffle_init(long shuffint)
374 {
375         shuffle_interval = shuffint;
376 
377         shuffle_idle_cpu = -1;
378 
379         if (!alloc_cpumask_var(&shuffle_tmp_mask, GFP_KERNEL)) {
380                 VERBOSE_TOROUT_ERRSTRING("Failed to alloc mask");
381                 return -ENOMEM;
382         }
383 
384         /* Create the shuffler thread */
385         return torture_create_kthread(torture_shuffle, NULL, shuffler_task);
386 }
387 EXPORT_SYMBOL_GPL(torture_shuffle_init);
388 
389 /*
390  * Stop the shuffling.
391  */
392 static void torture_shuffle_cleanup(void)
393 {
394         torture_shuffle_task_unregister_all();
395         if (shuffler_task) {
396                 VERBOSE_TOROUT_STRING("Stopping torture_shuffle task");
397                 kthread_stop(shuffler_task);
398                 free_cpumask_var(shuffle_tmp_mask);
399         }
400         shuffler_task = NULL;
401 }
402 EXPORT_SYMBOL_GPL(torture_shuffle_cleanup);
403 
404 /*
405  * Variables for auto-shutdown.  This allows "lights out" torture runs
406  * to be fully scripted.
407  */
408 static int shutdown_secs;               /* desired test duration in seconds. */
409 static struct task_struct *shutdown_task;
410 static unsigned long shutdown_time;     /* jiffies to system shutdown. */
411 static void (*torture_shutdown_hook)(void);
412 
413 /*
414  * Absorb kthreads into a kernel function that won't return, so that
415  * they won't ever access module text or data again.
416  */
417 void torture_shutdown_absorb(const char *title)
418 {
419         while (ACCESS_ONCE(fullstop) == FULLSTOP_SHUTDOWN) {
420                 pr_notice("torture thread %s parking due to system shutdown\n",
421                           title);
422                 schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT);
423         }
424 }
425 EXPORT_SYMBOL_GPL(torture_shutdown_absorb);
426 
427 /*
428  * Cause the torture test to shutdown the system after the test has
429  * run for the time specified by the shutdown_secs parameter.
430  */
431 static int torture_shutdown(void *arg)
432 {
433         long delta;
434         unsigned long jiffies_snap;
435 
436         VERBOSE_TOROUT_STRING("torture_shutdown task started");
437         jiffies_snap = jiffies;
438         while (ULONG_CMP_LT(jiffies_snap, shutdown_time) &&
439                !torture_must_stop()) {
440                 delta = shutdown_time - jiffies_snap;
441                 if (verbose)
442                         pr_alert("%s" TORTURE_FLAG
443                                  "torture_shutdown task: %lu jiffies remaining\n",
444                                  torture_type, delta);
445                 schedule_timeout_interruptible(delta);
446                 jiffies_snap = jiffies;
447         }
448         if (torture_must_stop()) {
449                 torture_kthread_stopping("torture_shutdown");
450                 return 0;
451         }
452 
453         /* OK, shut down the system. */
454 
455         VERBOSE_TOROUT_STRING("torture_shutdown task shutting down system");
456         shutdown_task = NULL;   /* Avoid self-kill deadlock. */
457         if (torture_shutdown_hook)
458                 torture_shutdown_hook();
459         else
460                 VERBOSE_TOROUT_STRING("No torture_shutdown_hook(), skipping.");
461         kernel_power_off();     /* Shut down the system. */
462         return 0;
463 }
464 
465 /*
466  * Start up the shutdown task.
467  */
468 int torture_shutdown_init(int ssecs, void (*cleanup)(void))
469 {
470         int ret = 0;
471 
472         shutdown_secs = ssecs;
473         torture_shutdown_hook = cleanup;
474         if (shutdown_secs > 0) {
475                 shutdown_time = jiffies + shutdown_secs * HZ;
476                 ret = torture_create_kthread(torture_shutdown, NULL,
477                                              shutdown_task);
478         }
479         return ret;
480 }
481 EXPORT_SYMBOL_GPL(torture_shutdown_init);
482 
483 /*
484  * Detect and respond to a system shutdown.
485  */
486 static int torture_shutdown_notify(struct notifier_block *unused1,
487                                    unsigned long unused2, void *unused3)
488 {
489         mutex_lock(&fullstop_mutex);
490         if (ACCESS_ONCE(fullstop) == FULLSTOP_DONTSTOP) {
491                 VERBOSE_TOROUT_STRING("Unscheduled system shutdown detected");
492                 ACCESS_ONCE(fullstop) = FULLSTOP_SHUTDOWN;
493         } else {
494                 pr_warn("Concurrent rmmod and shutdown illegal!\n");
495         }
496         mutex_unlock(&fullstop_mutex);
497         return NOTIFY_DONE;
498 }
499 
500 static struct notifier_block torture_shutdown_nb = {
501         .notifier_call = torture_shutdown_notify,
502 };
503 
504 /*
505  * Shut down the shutdown task.  Say what???  Heh!  This can happen if
506  * the torture module gets an rmmod before the shutdown time arrives.  ;-)
507  */
508 static void torture_shutdown_cleanup(void)
509 {
510         unregister_reboot_notifier(&torture_shutdown_nb);
511         if (shutdown_task != NULL) {
512                 VERBOSE_TOROUT_STRING("Stopping torture_shutdown task");
513                 kthread_stop(shutdown_task);
514         }
515         shutdown_task = NULL;
516 }
517 
518 /*
519  * Variables for stuttering, which means to periodically pause and
520  * restart testing in order to catch bugs that appear when load is
521  * suddenly applied to or removed from the system.
522  */
523 static struct task_struct *stutter_task;
524 static int stutter_pause_test;
525 static int stutter;
526 
527 /*
528  * Block until the stutter interval ends.  This must be called periodically
529  * by all running kthreads that need to be subject to stuttering.
530  */
531 void stutter_wait(const char *title)
532 {
533         while (ACCESS_ONCE(stutter_pause_test) ||
534                (torture_runnable && !ACCESS_ONCE(*torture_runnable))) {
535                 if (stutter_pause_test)
536                         schedule_timeout_interruptible(1);
537                 else
538                         schedule_timeout_interruptible(round_jiffies_relative(HZ));
539                 torture_shutdown_absorb(title);
540         }
541 }
542 EXPORT_SYMBOL_GPL(stutter_wait);
543 
544 /*
545  * Cause the torture test to "stutter", starting and stopping all
546  * threads periodically.
547  */
548 static int torture_stutter(void *arg)
549 {
550         VERBOSE_TOROUT_STRING("torture_stutter task started");
551         do {
552                 if (!torture_must_stop()) {
553                         schedule_timeout_interruptible(stutter);
554                         ACCESS_ONCE(stutter_pause_test) = 1;
555                 }
556                 if (!torture_must_stop())
557                         schedule_timeout_interruptible(stutter);
558                 ACCESS_ONCE(stutter_pause_test) = 0;
559                 torture_shutdown_absorb("torture_stutter");
560         } while (!torture_must_stop());
561         torture_kthread_stopping("torture_stutter");
562         return 0;
563 }
564 
565 /*
566  * Initialize and kick off the torture_stutter kthread.
567  */
568 int torture_stutter_init(int s)
569 {
570         int ret;
571 
572         stutter = s;
573         ret = torture_create_kthread(torture_stutter, NULL, stutter_task);
574         return ret;
575 }
576 EXPORT_SYMBOL_GPL(torture_stutter_init);
577 
578 /*
579  * Cleanup after the torture_stutter kthread.
580  */
581 static void torture_stutter_cleanup(void)
582 {
583         if (!stutter_task)
584                 return;
585         VERBOSE_TOROUT_STRING("Stopping torture_stutter task");
586         kthread_stop(stutter_task);
587         stutter_task = NULL;
588 }
589 
590 /*
591  * Initialize torture module.  Please note that this is -not- invoked via
592  * the usual module_init() mechanism, but rather by an explicit call from
593  * the client torture module.  This call must be paired with a later
594  * torture_init_end().
595  *
596  * The runnable parameter points to a flag that controls whether or not
597  * the test is currently runnable.  If there is no such flag, pass in NULL.
598  */
599 void __init torture_init_begin(char *ttype, bool v, int *runnable)
600 {
601         mutex_lock(&fullstop_mutex);
602         torture_type = ttype;
603         verbose = v;
604         torture_runnable = runnable;
605         fullstop = FULLSTOP_DONTSTOP;
606 
607 }
608 EXPORT_SYMBOL_GPL(torture_init_begin);
609 
610 /*
611  * Tell the torture module that initialization is complete.
612  */
613 void __init torture_init_end(void)
614 {
615         mutex_unlock(&fullstop_mutex);
616         register_reboot_notifier(&torture_shutdown_nb);
617 }
618 EXPORT_SYMBOL_GPL(torture_init_end);
619 
620 /*
621  * Clean up torture module.  Please note that this is -not- invoked via
622  * the usual module_exit() mechanism, but rather by an explicit call from
623  * the client torture module.  Returns true if a race with system shutdown
624  * is detected, otherwise, all kthreads started by functions in this file
625  * will be shut down.
626  *
627  * This must be called before the caller starts shutting down its own
628  * kthreads.
629  */
630 bool torture_cleanup(void)
631 {
632         mutex_lock(&fullstop_mutex);
633         if (ACCESS_ONCE(fullstop) == FULLSTOP_SHUTDOWN) {
634                 pr_warn("Concurrent rmmod and shutdown illegal!\n");
635                 mutex_unlock(&fullstop_mutex);
636                 schedule_timeout_uninterruptible(10);
637                 return true;
638         }
639         ACCESS_ONCE(fullstop) = FULLSTOP_RMMOD;
640         mutex_unlock(&fullstop_mutex);
641         torture_shutdown_cleanup();
642         torture_shuffle_cleanup();
643         torture_stutter_cleanup();
644         torture_onoff_cleanup();
645         return false;
646 }
647 EXPORT_SYMBOL_GPL(torture_cleanup);
648 
649 /*
650  * Is it time for the current torture test to stop?
651  */
652 bool torture_must_stop(void)
653 {
654         return torture_must_stop_irq() || kthread_should_stop();
655 }
656 EXPORT_SYMBOL_GPL(torture_must_stop);
657 
658 /*
659  * Is it time for the current torture test to stop?  This is the irq-safe
660  * version, hence no check for kthread_should_stop().
661  */
662 bool torture_must_stop_irq(void)
663 {
664         return ACCESS_ONCE(fullstop) != FULLSTOP_DONTSTOP;
665 }
666 EXPORT_SYMBOL_GPL(torture_must_stop_irq);
667 
668 /*
669  * Each kthread must wait for kthread_should_stop() before returning from
670  * its top-level function, otherwise segfaults ensue.  This function
671  * prints a "stopping" message and waits for kthread_should_stop(), and
672  * should be called from all torture kthreads immediately prior to
673  * returning.
674  */
675 void torture_kthread_stopping(char *title)
676 {
677         if (verbose)
678                 VERBOSE_TOROUT_STRING(title);
679         while (!kthread_should_stop()) {
680                 torture_shutdown_absorb(title);
681                 schedule_timeout_uninterruptible(1);
682         }
683 }
684 EXPORT_SYMBOL_GPL(torture_kthread_stopping);
685 
686 /*
687  * Create a generic torture kthread that is immediately runnable.  If you
688  * need the kthread to be stopped so that you can do something to it before
689  * it starts, you will need to open-code your own.
690  */
691 int _torture_create_kthread(int (*fn)(void *arg), void *arg, char *s, char *m,
692                             char *f, struct task_struct **tp)
693 {
694         int ret = 0;
695 
696         VERBOSE_TOROUT_STRING(m);
697         *tp = kthread_run(fn, arg, s);
698         if (IS_ERR(*tp)) {
699                 ret = PTR_ERR(*tp);
700                 VERBOSE_TOROUT_ERRSTRING(f);
701                 *tp = NULL;
702         }
703         torture_shuffle_task_register(*tp);
704         return ret;
705 }
706 EXPORT_SYMBOL_GPL(_torture_create_kthread);
707 
708 /*
709  * Stop a generic kthread, emitting a message.
710  */
711 void _torture_stop_kthread(char *m, struct task_struct **tp)
712 {
713         if (*tp == NULL)
714                 return;
715         VERBOSE_TOROUT_STRING(m);
716         kthread_stop(*tp);
717         *tp = NULL;
718 }
719 EXPORT_SYMBOL_GPL(_torture_stop_kthread);
720 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp