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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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#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 <linux/sched/rt.h>#include "rcu/rcu.h"
MODULE_DESCRIPTION("Common functions for in-kernel torture tests");MODULE_LICENSE("GPL");MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com>");
static bool disable_onoff_at_boot;module_param(disable_onoff_at_boot, bool, 0444);
static bool ftrace_dump_at_shutdown;module_param(ftrace_dump_at_shutdown, bool, 0444);
static int verbose_sleep_frequency;module_param(verbose_sleep_frequency, int, 0444);
static int verbose_sleep_duration = 1;module_param(verbose_sleep_duration, int, 0444);
static int random_shuffle;module_param(random_shuffle, int, 0444);
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);
static atomic_t verbose_sleep_counter;
/* * Sleep if needed from VERBOSE_TOROUT*(). */void verbose_torout_sleep(void){ if (verbose_sleep_frequency > 0 && verbose_sleep_duration > 0 && !(atomic_inc_return(&verbose_sleep_counter) % verbose_sleep_frequency)) schedule_timeout_uninterruptible(verbose_sleep_duration);}EXPORT_SYMBOL_GPL(verbose_torout_sleep);
/* * Schedule a high-resolution-timer sleep in nanoseconds, with a 32-bit * nanosecond random fuzz. This function and its friends desynchronize * testing from the timer wheel. */int torture_hrtimeout_ns(ktime_t baset_ns, u32 fuzzt_ns, const enum hrtimer_mode mode, struct torture_random_state *trsp){ ktime_t hto = baset_ns;
if (trsp && fuzzt_ns) hto += torture_random(trsp) % fuzzt_ns; set_current_state(TASK_IDLE); return schedule_hrtimeout(&hto, mode);}EXPORT_SYMBOL_GPL(torture_hrtimeout_ns);
/* * Schedule a high-resolution-timer sleep in microseconds, with a 32-bit * nanosecond (not microsecond!) random fuzz. */int torture_hrtimeout_us(u32 baset_us, u32 fuzzt_ns, struct torture_random_state *trsp){ ktime_t baset_ns = baset_us * NSEC_PER_USEC;
return torture_hrtimeout_ns(baset_ns, fuzzt_ns, HRTIMER_MODE_REL, trsp);}EXPORT_SYMBOL_GPL(torture_hrtimeout_us);
/* * Schedule a high-resolution-timer sleep in milliseconds, with a 32-bit * microsecond (not millisecond!) random fuzz. */int torture_hrtimeout_ms(u32 baset_ms, u32 fuzzt_us, struct torture_random_state *trsp){ ktime_t baset_ns = baset_ms * NSEC_PER_MSEC; u32 fuzzt_ns;
if ((u32)~0U / NSEC_PER_USEC < fuzzt_us) fuzzt_ns = (u32)~0U; else fuzzt_ns = fuzzt_us * NSEC_PER_USEC; return torture_hrtimeout_ns(baset_ns, fuzzt_ns, HRTIMER_MODE_REL, trsp);}EXPORT_SYMBOL_GPL(torture_hrtimeout_ms);
/* * Schedule a high-resolution-timer sleep in jiffies, with an * implied one-jiffy random fuzz. This is intended to replace calls to * schedule_timeout_interruptible() and friends. */int torture_hrtimeout_jiffies(u32 baset_j, struct torture_random_state *trsp){ ktime_t baset_ns = jiffies_to_nsecs(baset_j);
return torture_hrtimeout_ns(baset_ns, jiffies_to_nsecs(1), HRTIMER_MODE_REL, trsp);}EXPORT_SYMBOL_GPL(torture_hrtimeout_jiffies);
/* * Schedule a high-resolution-timer sleep in milliseconds, with a 32-bit * millisecond (not second!) random fuzz. */int torture_hrtimeout_s(u32 baset_s, u32 fuzzt_ms, struct torture_random_state *trsp){ ktime_t baset_ns = baset_s * NSEC_PER_SEC; u32 fuzzt_ns;
if ((u32)~0U / NSEC_PER_MSEC < fuzzt_ms) fuzzt_ns = (u32)~0U; else fuzzt_ns = fuzzt_ms * NSEC_PER_MSEC; return torture_hrtimeout_ns(baset_ns, fuzzt_ns, HRTIMER_MODE_REL, trsp);}EXPORT_SYMBOL_GPL(torture_hrtimeout_s);
#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 torture_ofl_func *onoff_f;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;
static int torture_online_cpus = NR_CPUS;
/* * Some torture testing leverages confusion as to the number of online * CPUs. This function returns the torture-testing view of this number, * which allows torture tests to load-balance appropriately. */int torture_num_online_cpus(void){ return READ_ONCE(torture_online_cpus);}EXPORT_SYMBOL_GPL(torture_num_online_cpus);
/* * 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; char *s; unsigned long starttime;
if (!cpu_online(cpu) || !cpu_is_hotpluggable(cpu)) return false; if (num_online_cpus() <= 1) return false; /* Can't offline the last CPU. */
if (verbose > 1) pr_alert("%s" TORTURE_FLAG "torture_onoff task: offlining %d\n", torture_type, cpu); starttime = jiffies; (*n_offl_attempts)++; ret = remove_cpu(cpu); if (ret) { s = ""; if (!rcu_inkernel_boot_has_ended() && ret == -EBUSY) { // PCI probe frequently disables hotplug during boot. (*n_offl_attempts)--; s = " (-EBUSY forgiven during boot)"; } if (verbose) pr_alert("%s" TORTURE_FLAG "torture_onoff task: offline %d failed%s: errno %d\n", torture_type, cpu, s, ret); } else { if (verbose > 1) pr_alert("%s" TORTURE_FLAG "torture_onoff task: offlined %d\n", torture_type, cpu); if (onoff_f) onoff_f(); (*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; WRITE_ONCE(torture_online_cpus, torture_online_cpus - 1); WARN_ON_ONCE(torture_online_cpus <= 0); }
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; char *s; 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 = add_cpu(cpu); if (ret) { s = ""; if (!rcu_inkernel_boot_has_ended() && ret == -EBUSY) { // PCI probe frequently disables hotplug during boot. (*n_onl_attempts)--; s = " (-EBUSY forgiven during boot)"; } if (verbose) pr_alert("%s" TORTURE_FLAG "torture_onoff task: online %d failed%s: errno %d\n", torture_type, cpu, s, 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; WRITE_ONCE(torture_online_cpus, torture_online_cpus + 1); }
return true;}EXPORT_SYMBOL_GPL(torture_online);
/* * Get everything online at the beginning and ends of tests. */static void torture_online_all(char *phase){ int cpu; int ret;
for_each_possible_cpu(cpu) { if (cpu_online(cpu)) continue; ret = add_cpu(cpu); if (ret && verbose) { pr_alert("%s" TORTURE_FLAG "%s: %s online %d: errno %d\n", __func__, phase, torture_type, cpu, ret); } }}
/* * Execute random CPU-hotplug operations at the interval specified * by the onoff_interval. */static inttorture_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); torture_online_all("Initial"); 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"); torture_hrtimeout_jiffies(onoff_holdoff, &rand); VERBOSE_TOROUT_STRING("torture_onoff end holdoff"); } while (!rcu_inkernel_boot_has_ended()) schedule_timeout_interruptible(HZ / 10); while (!torture_must_stop()) { if (disable_onoff_at_boot && !rcu_inkernel_boot_has_ended()) { torture_hrtimeout_jiffies(HZ / 10, &rand); continue; } cpu = torture_random(&rand) % (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); torture_hrtimeout_jiffies(onoff_interval, &rand); }
stop: torture_kthread_stopping("torture_onoff"); torture_online_all("Final"); return 0;}
#endif /* #ifdef CONFIG_HOTPLUG_CPU */
/* * Initiate online-offline handling. */int torture_onoff_init(long ooholdoff, long oointerval, torture_ofl_func *f){#ifdef CONFIG_HOTPLUG_CPU onoff_holdoff = ooholdoff; onoff_interval = oointerval; onoff_f = f; if (onoff_interval <= 0) return 0; return torture_create_kthread(torture_onoff, NULL, onoff_task);#else /* #ifdef CONFIG_HOTPLUG_CPU */ return 0;#endif /* #else #ifdef CONFIG_HOTPLUG_CPU */}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 */}
/* * 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 longtorture_random(struct torture_random_state *trsp){ if (--trsp->trs_count < 0) { trsp->trs_state += (unsigned long)local_clock() + raw_smp_processor_id(); 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_obj(*stp); 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(struct torture_random_state *trp){ struct shuffle_task *stp;
cpumask_setall(shuffle_tmp_mask); cpus_read_lock();
/* No point in shuffling if there is only one online CPU (ex: UP) */ if (num_online_cpus() == 1) { cpus_read_unlock(); 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) { if (!random_shuffle || torture_random(trp) & 0x1) set_cpus_allowed_ptr(stp->st_t, shuffle_tmp_mask); } mutex_unlock(&shuffle_task_mutex);
cpus_read_unlock();}
/* 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){ DEFINE_TORTURE_RANDOM(rand);
VERBOSE_TOROUT_STRING("torture_shuffle task started"); do { torture_hrtimeout_jiffies(shuffle_interval, &rand); torture_shuffle_tasks(&rand); 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)) { 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;}
/* * 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."); if (ftrace_dump_at_shutdown) 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)){ torture_shutdown_hook = cleanup; if (ssecs > 0) { shutdown_time = ktime_add(ktime_get(), ktime_set(ssecs, 0)); return torture_create_kthread(torture_shutdown, NULL, shutdown_task); } return 0;}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 ktime_t stutter_till_abs_time;static int stutter;static int stutter_gap;
/* * 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){ bool ret = false; ktime_t till_ns;
cond_resched_tasks_rcu_qs(); till_ns = READ_ONCE(stutter_till_abs_time); if (till_ns && ktime_before(ktime_get(), till_ns)) { torture_hrtimeout_ns(till_ns, 0, HRTIMER_MODE_ABS, NULL); ret = true; } torture_shutdown_absorb(title); return ret;}EXPORT_SYMBOL_GPL(stutter_wait);
/* * Cause the torture test to "stutter", starting and stopping all * threads periodically. */static int torture_stutter(void *arg){ ktime_t till_ns;
VERBOSE_TOROUT_STRING("torture_stutter task started"); do { if (!torture_must_stop() && stutter > 1) { till_ns = ktime_add_ns(ktime_get(), jiffies_to_nsecs(stutter)); WRITE_ONCE(stutter_till_abs_time, till_ns); torture_hrtimeout_jiffies(stutter - 1, NULL); } if (!torture_must_stop()) torture_hrtimeout_jiffies(stutter_gap, NULL); 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(const int s, const int sgap){ stutter = s; stutter_gap = sgap; return torture_create_kthread(torture_stutter, NULL, stutter_task);}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;}
static unsigned long torture_init_jiffies;
static voidtorture_print_module_parms(void){ 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%s\n", torture_type, disable_onoff_at_boot, ftrace_dump_at_shutdown, verbose_sleep_frequency, verbose_sleep_duration, random_shuffle, rcu_inkernel_boot_has_ended() ? "" : " still booting");}
/* * 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("%s: Refusing %s init: %s running.\n", __func__, ttype, torture_type); pr_alert("%s: One torture test at a time!\n", __func__); mutex_unlock(&fullstop_mutex); return false; } torture_type = ttype; verbose = v; fullstop = FULLSTOP_DONTSTOP; WRITE_ONCE(torture_init_jiffies, jiffies); // Lockless reads. torture_print_module_parms(); 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);
/* * Get the torture_init_begin()-time value of the jiffies counter. */unsigned long get_torture_init_jiffies(void){ return READ_ONCE(torture_init_jiffies);}EXPORT_SYMBOL_GPL(get_torture_init_jiffies);
/* * 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), "%s is stopping", title); VERBOSE_TOROUT_STRING(buf); while (!kthread_should_stop()) { torture_shutdown_absorb(title); schedule_timeout_uninterruptible(HZ / 20); }}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, void (*cbf)(struct task_struct *tp)){ int ret = 0;
VERBOSE_TOROUT_STRING(m); *tp = kthread_create(fn, arg, "%s", s); if (IS_ERR(*tp)) { ret = PTR_ERR(*tp); TOROUT_ERRSTRING(f); *tp = NULL; return ret; }
if (cbf) cbf(*tp);
wake_up_process(*tp); // Process is sleeping, so ordering provided. 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);
/* * Set the specified task's niceness value, saturating at limits. * Saturating noisily, but saturating. */void torture_sched_set_normal(struct task_struct *t, int nice){ int realnice = nice;
if (WARN_ON_ONCE(realnice > MAX_NICE)) realnice = MAX_NICE; if (WARN_ON_ONCE(realnice < MIN_NICE)) realnice = MIN_NICE; sched_set_normal(t, realnice);}EXPORT_SYMBOL_GPL(torture_sched_set_normal);