| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Paul E. McKenney | 2518 | 98.21% | 34 | 82.93% |
| Boqun Feng | 18 | 0.70% | 1 | 2.44% |
| Davidlohr Bueso A | 18 | 0.70% | 1 | 2.44% |
| Joe Perches | 3 | 0.12% | 1 | 2.44% |
| Ingo Molnar | 3 | 0.12% | 1 | 2.44% |
| Kees Cook | 2 | 0.08% | 1 | 2.44% |
| Iulia Manda | 1 | 0.04% | 1 | 2.44% |
| Masahiro Yamada | 1 | 0.04% | 1 | 2.44% |
| Total | 2564 | 41 |
/* * 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. */ #define pr_fmt(fmt) fmt #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/sched/clock.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> #include "rcu/rcu.h" MODULE_LICENSE("GPL"); MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com>"); static char *torture_type; static int 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); #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 > 1) 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 > 1) 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 > 1) 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 > 1) 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."); rcu_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. */ bool stutter_wait(const char *title) { int spt; cond_resched_tasks_rcu_qs(); spt = READ_ONCE(stutter_pause_test); for (; spt; spt = READ_ONCE(stutter_pause_test)) { if (spt == 1) { schedule_timeout_interruptible(1); } else if (spt == 2) { while (READ_ONCE(stutter_pause_test)) cond_resched(); } else { schedule_timeout_interruptible(round_jiffies_relative(HZ)); } torture_shutdown_absorb(title); } return !!spt; } 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() && stutter > 1) { WRITE_ONCE(stutter_pause_test, 1); schedule_timeout_interruptible(stutter - 1); WRITE_ONCE(stutter_pause_test, 2); schedule_timeout_interruptible(1); } WRITE_ONCE(stutter_pause_test, 0); if (!torture_must_stop()) schedule_timeout_interruptible(stutter); 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, int v) { 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; 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);
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