| /* |
| * Common functions for in-kernel torture tests. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, you can access it online at |
| * http://www.gnu.org/licenses/gpl-2.0.html. |
| * |
| * Copyright (C) IBM Corporation, 2014 |
| * |
| * Author: Paul E. McKenney <paulmck@us.ibm.com> |
| * Based on kernel/rcu/torture.c. |
| */ |
| #include <linux/types.h> |
| #include <linux/kernel.h> |
| #include <linux/init.h> |
| #include <linux/module.h> |
| #include <linux/kthread.h> |
| #include <linux/err.h> |
| #include <linux/spinlock.h> |
| #include <linux/smp.h> |
| #include <linux/interrupt.h> |
| #include <linux/sched.h> |
| #include <linux/atomic.h> |
| #include <linux/bitops.h> |
| #include <linux/completion.h> |
| #include <linux/moduleparam.h> |
| #include <linux/percpu.h> |
| #include <linux/notifier.h> |
| #include <linux/reboot.h> |
| #include <linux/freezer.h> |
| #include <linux/cpu.h> |
| #include <linux/delay.h> |
| #include <linux/stat.h> |
| #include <linux/slab.h> |
| #include <linux/trace_clock.h> |
| #include <linux/ktime.h> |
| #include <asm/byteorder.h> |
| #include <linux/torture.h> |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com>"); |
| |
| static char *torture_type; |
| static bool verbose; |
| |
| /* Mediate rmmod and system shutdown. Concurrent rmmod & shutdown illegal! */ |
| #define FULLSTOP_DONTSTOP 0 /* Normal operation. */ |
| #define FULLSTOP_SHUTDOWN 1 /* System shutdown with torture running. */ |
| #define FULLSTOP_RMMOD 2 /* Normal rmmod of torture. */ |
| static int fullstop = FULLSTOP_RMMOD; |
| static DEFINE_MUTEX(fullstop_mutex); |
| static int *torture_runnable; |
| |
| #ifdef CONFIG_HOTPLUG_CPU |
| |
| /* |
| * Variables for online-offline handling. Only present if CPU hotplug |
| * is enabled, otherwise does nothing. |
| */ |
| |
| static struct task_struct *onoff_task; |
| static long onoff_holdoff; |
| static long onoff_interval; |
| static long n_offline_attempts; |
| static long n_offline_successes; |
| static unsigned long sum_offline; |
| static int min_offline = -1; |
| static int max_offline; |
| static long n_online_attempts; |
| static long n_online_successes; |
| static unsigned long sum_online; |
| static int min_online = -1; |
| static int max_online; |
| |
| /* |
| * Attempt to take a CPU offline. Return false if the CPU is already |
| * offline or if it is not subject to CPU-hotplug operations. The |
| * caller can detect other failures by looking at the statistics. |
| */ |
| bool torture_offline(int cpu, long *n_offl_attempts, long *n_offl_successes, |
| unsigned long *sum_offl, int *min_offl, int *max_offl) |
| { |
| unsigned long delta; |
| int ret; |
| unsigned long starttime; |
| |
| if (!cpu_online(cpu) || !cpu_is_hotpluggable(cpu)) |
| return false; |
| |
| if (verbose) |
| pr_alert("%s" TORTURE_FLAG |
| "torture_onoff task: offlining %d\n", |
| torture_type, cpu); |
| starttime = jiffies; |
| (*n_offl_attempts)++; |
| ret = cpu_down(cpu); |
| if (ret) { |
| if (verbose) |
| pr_alert("%s" TORTURE_FLAG |
| "torture_onoff task: offline %d failed: errno %d\n", |
| torture_type, cpu, ret); |
| } else { |
| if (verbose) |
| pr_alert("%s" TORTURE_FLAG |
| "torture_onoff task: offlined %d\n", |
| torture_type, cpu); |
| (*n_offl_successes)++; |
| delta = jiffies - starttime; |
| sum_offl += delta; |
| if (*min_offl < 0) { |
| *min_offl = delta; |
| *max_offl = delta; |
| } |
| if (*min_offl > delta) |
| *min_offl = delta; |
| if (*max_offl < delta) |
| *max_offl = delta; |
| } |
| |
| return true; |
| } |
| EXPORT_SYMBOL_GPL(torture_offline); |
| |
| /* |
| * Attempt to bring a CPU online. Return false if the CPU is already |
| * online or if it is not subject to CPU-hotplug operations. The |
| * caller can detect other failures by looking at the statistics. |
| */ |
| bool torture_online(int cpu, long *n_onl_attempts, long *n_onl_successes, |
| unsigned long *sum_onl, int *min_onl, int *max_onl) |
| { |
| unsigned long delta; |
| int ret; |
| unsigned long starttime; |
| |
| if (cpu_online(cpu) || !cpu_is_hotpluggable(cpu)) |
| return false; |
| |
| if (verbose) |
| pr_alert("%s" TORTURE_FLAG |
| "torture_onoff task: onlining %d\n", |
| torture_type, cpu); |
| starttime = jiffies; |
| (*n_onl_attempts)++; |
| ret = cpu_up(cpu); |
| if (ret) { |
| if (verbose) |
| pr_alert("%s" TORTURE_FLAG |
| "torture_onoff task: online %d failed: errno %d\n", |
| torture_type, cpu, ret); |
| } else { |
| if (verbose) |
| pr_alert("%s" TORTURE_FLAG |
| "torture_onoff task: onlined %d\n", |
| torture_type, cpu); |
| (*n_onl_successes)++; |
| delta = jiffies - starttime; |
| *sum_onl += delta; |
| if (*min_onl < 0) { |
| *min_onl = delta; |
| *max_onl = delta; |
| } |
| if (*min_onl > delta) |
| *min_onl = delta; |
| if (*max_onl < delta) |
| *max_onl = delta; |
| } |
| |
| return true; |
| } |
| EXPORT_SYMBOL_GPL(torture_online); |
| |
| /* |
| * Execute random CPU-hotplug operations at the interval specified |
| * by the onoff_interval. |
| */ |
| static int |
| torture_onoff(void *arg) |
| { |
| int cpu; |
| int maxcpu = -1; |
| DEFINE_TORTURE_RANDOM(rand); |
| |
| VERBOSE_TOROUT_STRING("torture_onoff task started"); |
| for_each_online_cpu(cpu) |
| maxcpu = cpu; |
| WARN_ON(maxcpu < 0); |
| |
| if (maxcpu == 0) { |
| VERBOSE_TOROUT_STRING("Only one CPU, so CPU-hotplug testing is disabled"); |
| goto stop; |
| } |
| |
| if (onoff_holdoff > 0) { |
| VERBOSE_TOROUT_STRING("torture_onoff begin holdoff"); |
| schedule_timeout_interruptible(onoff_holdoff); |
| VERBOSE_TOROUT_STRING("torture_onoff end holdoff"); |
| } |
| while (!torture_must_stop()) { |
| cpu = (torture_random(&rand) >> 4) % (maxcpu + 1); |
| if (!torture_offline(cpu, |
| &n_offline_attempts, &n_offline_successes, |
| &sum_offline, &min_offline, &max_offline)) |
| torture_online(cpu, |
| &n_online_attempts, &n_online_successes, |
| &sum_online, &min_online, &max_online); |
| schedule_timeout_interruptible(onoff_interval); |
| } |
| |
| stop: |
| torture_kthread_stopping("torture_onoff"); |
| return 0; |
| } |
| |
| #endif /* #ifdef CONFIG_HOTPLUG_CPU */ |
| |
| /* |
| * Initiate online-offline handling. |
| */ |
| int torture_onoff_init(long ooholdoff, long oointerval) |
| { |
| int ret = 0; |
| |
| #ifdef CONFIG_HOTPLUG_CPU |
| onoff_holdoff = ooholdoff; |
| onoff_interval = oointerval; |
| if (onoff_interval <= 0) |
| return 0; |
| ret = torture_create_kthread(torture_onoff, NULL, onoff_task); |
| #endif /* #ifdef CONFIG_HOTPLUG_CPU */ |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(torture_onoff_init); |
| |
| /* |
| * Clean up after online/offline testing. |
| */ |
| static void torture_onoff_cleanup(void) |
| { |
| #ifdef CONFIG_HOTPLUG_CPU |
| if (onoff_task == NULL) |
| return; |
| VERBOSE_TOROUT_STRING("Stopping torture_onoff task"); |
| kthread_stop(onoff_task); |
| onoff_task = NULL; |
| #endif /* #ifdef CONFIG_HOTPLUG_CPU */ |
| } |
| EXPORT_SYMBOL_GPL(torture_onoff_cleanup); |
| |
| /* |
| * Print online/offline testing statistics. |
| */ |
| void torture_onoff_stats(void) |
| { |
| #ifdef CONFIG_HOTPLUG_CPU |
| pr_cont("onoff: %ld/%ld:%ld/%ld %d,%d:%d,%d %lu:%lu (HZ=%d) ", |
| n_online_successes, n_online_attempts, |
| n_offline_successes, n_offline_attempts, |
| min_online, max_online, |
| min_offline, max_offline, |
| sum_online, sum_offline, HZ); |
| #endif /* #ifdef CONFIG_HOTPLUG_CPU */ |
| } |
| EXPORT_SYMBOL_GPL(torture_onoff_stats); |
| |
| /* |
| * Were all the online/offline operations successful? |
| */ |
| bool torture_onoff_failures(void) |
| { |
| #ifdef CONFIG_HOTPLUG_CPU |
| return n_online_successes != n_online_attempts || |
| n_offline_successes != n_offline_attempts; |
| #else /* #ifdef CONFIG_HOTPLUG_CPU */ |
| return false; |
| #endif /* #else #ifdef CONFIG_HOTPLUG_CPU */ |
| } |
| EXPORT_SYMBOL_GPL(torture_onoff_failures); |
| |
| #define TORTURE_RANDOM_MULT 39916801 /* prime */ |
| #define TORTURE_RANDOM_ADD 479001701 /* prime */ |
| #define TORTURE_RANDOM_REFRESH 10000 |
| |
| /* |
| * Crude but fast random-number generator. Uses a linear congruential |
| * generator, with occasional help from cpu_clock(). |
| */ |
| unsigned long |
| torture_random(struct torture_random_state *trsp) |
| { |
| if (--trsp->trs_count < 0) { |
| trsp->trs_state += (unsigned long)local_clock(); |
| trsp->trs_count = TORTURE_RANDOM_REFRESH; |
| } |
| trsp->trs_state = trsp->trs_state * TORTURE_RANDOM_MULT + |
| TORTURE_RANDOM_ADD; |
| return swahw32(trsp->trs_state); |
| } |
| EXPORT_SYMBOL_GPL(torture_random); |
| |
| /* |
| * Variables for shuffling. The idea is to ensure that each CPU stays |
| * idle for an extended period to test interactions with dyntick idle, |
| * as well as interactions with any per-CPU variables. |
| */ |
| struct shuffle_task { |
| struct list_head st_l; |
| struct task_struct *st_t; |
| }; |
| |
| static long shuffle_interval; /* In jiffies. */ |
| static struct task_struct *shuffler_task; |
| static cpumask_var_t shuffle_tmp_mask; |
| static int shuffle_idle_cpu; /* Force all torture tasks off this CPU */ |
| static struct list_head shuffle_task_list = LIST_HEAD_INIT(shuffle_task_list); |
| static DEFINE_MUTEX(shuffle_task_mutex); |
| |
| /* |
| * Register a task to be shuffled. If there is no memory, just splat |
| * and don't bother registering. |
| */ |
| void torture_shuffle_task_register(struct task_struct *tp) |
| { |
| struct shuffle_task *stp; |
| |
| if (WARN_ON_ONCE(tp == NULL)) |
| return; |
| stp = kmalloc(sizeof(*stp), GFP_KERNEL); |
| if (WARN_ON_ONCE(stp == NULL)) |
| return; |
| stp->st_t = tp; |
| mutex_lock(&shuffle_task_mutex); |
| list_add(&stp->st_l, &shuffle_task_list); |
| mutex_unlock(&shuffle_task_mutex); |
| } |
| EXPORT_SYMBOL_GPL(torture_shuffle_task_register); |
| |
| /* |
| * Unregister all tasks, for example, at the end of the torture run. |
| */ |
| static void torture_shuffle_task_unregister_all(void) |
| { |
| struct shuffle_task *stp; |
| struct shuffle_task *p; |
| |
| mutex_lock(&shuffle_task_mutex); |
| list_for_each_entry_safe(stp, p, &shuffle_task_list, st_l) { |
| list_del(&stp->st_l); |
| kfree(stp); |
| } |
| mutex_unlock(&shuffle_task_mutex); |
| } |
| |
| /* Shuffle tasks such that we allow shuffle_idle_cpu to become idle. |
| * A special case is when shuffle_idle_cpu = -1, in which case we allow |
| * the tasks to run on all CPUs. |
| */ |
| static void torture_shuffle_tasks(void) |
| { |
| struct shuffle_task *stp; |
| |
| cpumask_setall(shuffle_tmp_mask); |
| get_online_cpus(); |
| |
| /* No point in shuffling if there is only one online CPU (ex: UP) */ |
| if (num_online_cpus() == 1) { |
| put_online_cpus(); |
| return; |
| } |
| |
| /* Advance to the next CPU. Upon overflow, don't idle any CPUs. */ |
| shuffle_idle_cpu = cpumask_next(shuffle_idle_cpu, shuffle_tmp_mask); |
| if (shuffle_idle_cpu >= nr_cpu_ids) |
| shuffle_idle_cpu = -1; |
| else |
| cpumask_clear_cpu(shuffle_idle_cpu, shuffle_tmp_mask); |
| |
| mutex_lock(&shuffle_task_mutex); |
| list_for_each_entry(stp, &shuffle_task_list, st_l) |
| set_cpus_allowed_ptr(stp->st_t, shuffle_tmp_mask); |
| mutex_unlock(&shuffle_task_mutex); |
| |
| put_online_cpus(); |
| } |
| |
| /* Shuffle tasks across CPUs, with the intent of allowing each CPU in the |
| * system to become idle at a time and cut off its timer ticks. This is meant |
| * to test the support for such tickless idle CPU in RCU. |
| */ |
| static int torture_shuffle(void *arg) |
| { |
| VERBOSE_TOROUT_STRING("torture_shuffle task started"); |
| do { |
| schedule_timeout_interruptible(shuffle_interval); |
| torture_shuffle_tasks(); |
| torture_shutdown_absorb("torture_shuffle"); |
| } while (!torture_must_stop()); |
| torture_kthread_stopping("torture_shuffle"); |
| return 0; |
| } |
| |
| /* |
| * Start the shuffler, with shuffint in jiffies. |
| */ |
| int torture_shuffle_init(long shuffint) |
| { |
| shuffle_interval = shuffint; |
| |
| shuffle_idle_cpu = -1; |
| |
| if (!alloc_cpumask_var(&shuffle_tmp_mask, GFP_KERNEL)) { |
| VERBOSE_TOROUT_ERRSTRING("Failed to alloc mask"); |
| return -ENOMEM; |
| } |
| |
| /* Create the shuffler thread */ |
| return torture_create_kthread(torture_shuffle, NULL, shuffler_task); |
| } |
| EXPORT_SYMBOL_GPL(torture_shuffle_init); |
| |
| /* |
| * Stop the shuffling. |
| */ |
| static void torture_shuffle_cleanup(void) |
| { |
| torture_shuffle_task_unregister_all(); |
| if (shuffler_task) { |
| VERBOSE_TOROUT_STRING("Stopping torture_shuffle task"); |
| kthread_stop(shuffler_task); |
| free_cpumask_var(shuffle_tmp_mask); |
| } |
| shuffler_task = NULL; |
| } |
| EXPORT_SYMBOL_GPL(torture_shuffle_cleanup); |
| |
| /* |
| * Variables for auto-shutdown. This allows "lights out" torture runs |
| * to be fully scripted. |
| */ |
| static struct task_struct *shutdown_task; |
| static ktime_t shutdown_time; /* time to system shutdown. */ |
| static void (*torture_shutdown_hook)(void); |
| |
| /* |
| * Absorb kthreads into a kernel function that won't return, so that |
| * they won't ever access module text or data again. |
| */ |
| void torture_shutdown_absorb(const char *title) |
| { |
| while (READ_ONCE(fullstop) == FULLSTOP_SHUTDOWN) { |
| pr_notice("torture thread %s parking due to system shutdown\n", |
| title); |
| schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT); |
| } |
| } |
| EXPORT_SYMBOL_GPL(torture_shutdown_absorb); |
| |
| /* |
| * Cause the torture test to shutdown the system after the test has |
| * run for the time specified by the shutdown_secs parameter. |
| */ |
| static int torture_shutdown(void *arg) |
| { |
| ktime_t ktime_snap; |
| |
| VERBOSE_TOROUT_STRING("torture_shutdown task started"); |
| ktime_snap = ktime_get(); |
| while (ktime_before(ktime_snap, shutdown_time) && |
| !torture_must_stop()) { |
| if (verbose) |
| pr_alert("%s" TORTURE_FLAG |
| "torture_shutdown task: %llu ms remaining\n", |
| torture_type, |
| ktime_ms_delta(shutdown_time, ktime_snap)); |
| set_current_state(TASK_INTERRUPTIBLE); |
| schedule_hrtimeout(&shutdown_time, HRTIMER_MODE_ABS); |
| ktime_snap = ktime_get(); |
| } |
| if (torture_must_stop()) { |
| torture_kthread_stopping("torture_shutdown"); |
| return 0; |
| } |
| |
| /* OK, shut down the system. */ |
| |
| VERBOSE_TOROUT_STRING("torture_shutdown task shutting down system"); |
| shutdown_task = NULL; /* Avoid self-kill deadlock. */ |
| if (torture_shutdown_hook) |
| torture_shutdown_hook(); |
| else |
| VERBOSE_TOROUT_STRING("No torture_shutdown_hook(), skipping."); |
| ftrace_dump(DUMP_ALL); |
| kernel_power_off(); /* Shut down the system. */ |
| return 0; |
| } |
| |
| /* |
| * Start up the shutdown task. |
| */ |
| int torture_shutdown_init(int ssecs, void (*cleanup)(void)) |
| { |
| int ret = 0; |
| |
| torture_shutdown_hook = cleanup; |
| if (ssecs > 0) { |
| shutdown_time = ktime_add(ktime_get(), ktime_set(ssecs, 0)); |
| ret = torture_create_kthread(torture_shutdown, NULL, |
| shutdown_task); |
| } |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(torture_shutdown_init); |
| |
| /* |
| * Detect and respond to a system shutdown. |
| */ |
| static int torture_shutdown_notify(struct notifier_block *unused1, |
| unsigned long unused2, void *unused3) |
| { |
| mutex_lock(&fullstop_mutex); |
| if (READ_ONCE(fullstop) == FULLSTOP_DONTSTOP) { |
| VERBOSE_TOROUT_STRING("Unscheduled system shutdown detected"); |
| WRITE_ONCE(fullstop, FULLSTOP_SHUTDOWN); |
| } else { |
| pr_warn("Concurrent rmmod and shutdown illegal!\n"); |
| } |
| mutex_unlock(&fullstop_mutex); |
| return NOTIFY_DONE; |
| } |
| |
| static struct notifier_block torture_shutdown_nb = { |
| .notifier_call = torture_shutdown_notify, |
| }; |
| |
| /* |
| * Shut down the shutdown task. Say what??? Heh! This can happen if |
| * the torture module gets an rmmod before the shutdown time arrives. ;-) |
| */ |
| static void torture_shutdown_cleanup(void) |
| { |
| unregister_reboot_notifier(&torture_shutdown_nb); |
| if (shutdown_task != NULL) { |
| VERBOSE_TOROUT_STRING("Stopping torture_shutdown task"); |
| kthread_stop(shutdown_task); |
| } |
| shutdown_task = NULL; |
| } |
| |
| /* |
| * Variables for stuttering, which means to periodically pause and |
| * restart testing in order to catch bugs that appear when load is |
| * suddenly applied to or removed from the system. |
| */ |
| static struct task_struct *stutter_task; |
| static int stutter_pause_test; |
| static int stutter; |
| |
| /* |
| * Block until the stutter interval ends. This must be called periodically |
| * by all running kthreads that need to be subject to stuttering. |
| */ |
| void stutter_wait(const char *title) |
| { |
| cond_resched_rcu_qs(); |
| while (READ_ONCE(stutter_pause_test) || |
| (torture_runnable && !READ_ONCE(*torture_runnable))) { |
| if (stutter_pause_test) |
| if (READ_ONCE(stutter_pause_test) == 1) |
| schedule_timeout_interruptible(1); |
| else |
| while (READ_ONCE(stutter_pause_test)) |
| cond_resched(); |
| else |
| schedule_timeout_interruptible(round_jiffies_relative(HZ)); |
| torture_shutdown_absorb(title); |
| } |
| } |
| EXPORT_SYMBOL_GPL(stutter_wait); |
| |
| /* |
| * Cause the torture test to "stutter", starting and stopping all |
| * threads periodically. |
| */ |
| static int torture_stutter(void *arg) |
| { |
| VERBOSE_TOROUT_STRING("torture_stutter task started"); |
| do { |
| if (!torture_must_stop()) { |
| if (stutter > 1) { |
| schedule_timeout_interruptible(stutter - 1); |
| WRITE_ONCE(stutter_pause_test, 2); |
| } |
| schedule_timeout_interruptible(1); |
| WRITE_ONCE(stutter_pause_test, 1); |
| } |
| if (!torture_must_stop()) |
| schedule_timeout_interruptible(stutter); |
| WRITE_ONCE(stutter_pause_test, 0); |
| torture_shutdown_absorb("torture_stutter"); |
| } while (!torture_must_stop()); |
| torture_kthread_stopping("torture_stutter"); |
| return 0; |
| } |
| |
| /* |
| * Initialize and kick off the torture_stutter kthread. |
| */ |
| int torture_stutter_init(int s) |
| { |
| int ret; |
| |
| stutter = s; |
| ret = torture_create_kthread(torture_stutter, NULL, stutter_task); |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(torture_stutter_init); |
| |
| /* |
| * Cleanup after the torture_stutter kthread. |
| */ |
| static void torture_stutter_cleanup(void) |
| { |
| if (!stutter_task) |
| return; |
| VERBOSE_TOROUT_STRING("Stopping torture_stutter task"); |
| kthread_stop(stutter_task); |
| stutter_task = NULL; |
| } |
| |
| /* |
| * Initialize torture module. Please note that this is -not- invoked via |
| * the usual module_init() mechanism, but rather by an explicit call from |
| * the client torture module. This call must be paired with a later |
| * torture_init_end(). |
| * |
| * The runnable parameter points to a flag that controls whether or not |
| * the test is currently runnable. If there is no such flag, pass in NULL. |
| */ |
| bool torture_init_begin(char *ttype, bool v, int *runnable) |
| { |
| mutex_lock(&fullstop_mutex); |
| if (torture_type != NULL) { |
| pr_alert("torture_init_begin: Refusing %s init: %s running.\n", |
| ttype, torture_type); |
| pr_alert("torture_init_begin: One torture test at a time!\n"); |
| mutex_unlock(&fullstop_mutex); |
| return false; |
| } |
| torture_type = ttype; |
| verbose = v; |
| torture_runnable = runnable; |
| fullstop = FULLSTOP_DONTSTOP; |
| return true; |
| } |
| EXPORT_SYMBOL_GPL(torture_init_begin); |
| |
| /* |
| * Tell the torture module that initialization is complete. |
| */ |
| void torture_init_end(void) |
| { |
| mutex_unlock(&fullstop_mutex); |
| register_reboot_notifier(&torture_shutdown_nb); |
| } |
| EXPORT_SYMBOL_GPL(torture_init_end); |
| |
| /* |
| * Clean up torture module. Please note that this is -not- invoked via |
| * the usual module_exit() mechanism, but rather by an explicit call from |
| * the client torture module. Returns true if a race with system shutdown |
| * is detected, otherwise, all kthreads started by functions in this file |
| * will be shut down. |
| * |
| * This must be called before the caller starts shutting down its own |
| * kthreads. |
| * |
| * Both torture_cleanup_begin() and torture_cleanup_end() must be paired, |
| * in order to correctly perform the cleanup. They are separated because |
| * threads can still need to reference the torture_type type, thus nullify |
| * only after completing all other relevant calls. |
| */ |
| bool torture_cleanup_begin(void) |
| { |
| mutex_lock(&fullstop_mutex); |
| if (READ_ONCE(fullstop) == FULLSTOP_SHUTDOWN) { |
| pr_warn("Concurrent rmmod and shutdown illegal!\n"); |
| mutex_unlock(&fullstop_mutex); |
| schedule_timeout_uninterruptible(10); |
| return true; |
| } |
| WRITE_ONCE(fullstop, FULLSTOP_RMMOD); |
| mutex_unlock(&fullstop_mutex); |
| torture_shutdown_cleanup(); |
| torture_shuffle_cleanup(); |
| torture_stutter_cleanup(); |
| torture_onoff_cleanup(); |
| return false; |
| } |
| EXPORT_SYMBOL_GPL(torture_cleanup_begin); |
| |
| void torture_cleanup_end(void) |
| { |
| mutex_lock(&fullstop_mutex); |
| torture_type = NULL; |
| mutex_unlock(&fullstop_mutex); |
| } |
| EXPORT_SYMBOL_GPL(torture_cleanup_end); |
| |
| /* |
| * Is it time for the current torture test to stop? |
| */ |
| bool torture_must_stop(void) |
| { |
| return torture_must_stop_irq() || kthread_should_stop(); |
| } |
| EXPORT_SYMBOL_GPL(torture_must_stop); |
| |
| /* |
| * Is it time for the current torture test to stop? This is the irq-safe |
| * version, hence no check for kthread_should_stop(). |
| */ |
| bool torture_must_stop_irq(void) |
| { |
| return READ_ONCE(fullstop) != FULLSTOP_DONTSTOP; |
| } |
| EXPORT_SYMBOL_GPL(torture_must_stop_irq); |
| |
| /* |
| * Each kthread must wait for kthread_should_stop() before returning from |
| * its top-level function, otherwise segfaults ensue. This function |
| * prints a "stopping" message and waits for kthread_should_stop(), and |
| * should be called from all torture kthreads immediately prior to |
| * returning. |
| */ |
| void torture_kthread_stopping(char *title) |
| { |
| char buf[128]; |
| |
| snprintf(buf, sizeof(buf), "Stopping %s", title); |
| VERBOSE_TOROUT_STRING(buf); |
| while (!kthread_should_stop()) { |
| torture_shutdown_absorb(title); |
| schedule_timeout_uninterruptible(1); |
| } |
| } |
| EXPORT_SYMBOL_GPL(torture_kthread_stopping); |
| |
| /* |
| * Create a generic torture kthread that is immediately runnable. If you |
| * need the kthread to be stopped so that you can do something to it before |
| * it starts, you will need to open-code your own. |
| */ |
| int _torture_create_kthread(int (*fn)(void *arg), void *arg, char *s, char *m, |
| char *f, struct task_struct **tp) |
| { |
| int ret = 0; |
| |
| VERBOSE_TOROUT_STRING(m); |
| *tp = kthread_run(fn, arg, "%s", s); |
| if (IS_ERR(*tp)) { |
| ret = PTR_ERR(*tp); |
| VERBOSE_TOROUT_ERRSTRING(f); |
| *tp = NULL; |
| } |
| torture_shuffle_task_register(*tp); |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(_torture_create_kthread); |
| |
| /* |
| * Stop a generic kthread, emitting a message. |
| */ |
| void _torture_stop_kthread(char *m, struct task_struct **tp) |
| { |
| if (*tp == NULL) |
| return; |
| VERBOSE_TOROUT_STRING(m); |
| kthread_stop(*tp); |
| *tp = NULL; |
| } |
| EXPORT_SYMBOL_GPL(_torture_stop_kthread); |