/* * Module-based torture test facility for locking * * 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 <asm/byteorder.h>#include <linux/torture.h> MODULE_LICENSE("GPL");MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com>"); torture_param(int, nwriters_stress, -1,	     "Number of write-locking stress-test threads");torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)");torture_param(int, onoff_interval, 0,	     "Time between CPU hotplugs (s), 0=disable");torture_param(int, shuffle_interval, 3,	     "Number of jiffies between shuffles, 0=disable");torture_param(int, shutdown_secs, 0, "Shutdown time (j), <= zero to disable.");torture_param(int, stat_interval, 60,	     "Number of seconds between stats printk()s");torture_param(int, stutter, 5, "Number of jiffies to run/halt test, 0=disable");torture_param(bool, verbose, true,	     "Enable verbose debugging printk()s"); static char *torture_type = "spin_lock";module_param(torture_type, charp, 0444);MODULE_PARM_DESC(torture_type,		 "Type of lock to torture (spin_lock, spin_lock_irq, ...)"); static atomic_t n_lock_torture_errors; static struct task_struct *stats_task;static struct task_struct **writer_tasks; static int nrealwriters_stress;static bool lock_is_write_held; struct lock_writer_stress_stats {	long n_write_lock_fail;	long n_write_lock_acquired;};static struct lock_writer_stress_stats *lwsa; #if defined(MODULE)#define LOCKTORTURE_RUNNABLE_INIT 1#else#define LOCKTORTURE_RUNNABLE_INIT 0#endifint locktorture_runnable = LOCKTORTURE_RUNNABLE_INIT;module_param(locktorture_runnable, int, 0444);MODULE_PARM_DESC(locktorture_runnable, "Start locktorture at module init"); /* Forward reference. */static void lock_torture_cleanup(void); /* * Operations vector for selecting different types of tests. */struct lock_torture_ops {	void (*init)(void);	int (*writelock)(void);	void (*write_delay)(struct torture_random_state *trsp);	void (*writeunlock)(void);	unsigned long flags;	const char *name;}; static struct lock_torture_ops *cur_ops; /* * Definitions for lock torture testing. */ static int torture_lock_busted_write_lock(void){	return 0;  /* BUGGY, do not use in real life!!! */} static void torture_lock_busted_write_delay(struct torture_random_state *trsp){	const unsigned long longdelay_us = 100; 	/* We want a long delay occasionally to force massive contention.  */	if (!(torture_random(trsp) %	      (nrealwriters_stress * 2000 * longdelay_us)))		mdelay(longdelay_us);#ifdef CONFIG_PREEMPT	if (!(torture_random(trsp) % (nrealwriters_stress * 20000)))		preempt_schedule();  /* Allow test to be preempted. */#endif} static void torture_lock_busted_write_unlock(void){	  /* BUGGY, do not use in real life!!! */} static struct lock_torture_ops lock_busted_ops = {	.writelock	= torture_lock_busted_write_lock,	.write_delay	= torture_lock_busted_write_delay,	.writeunlock	= torture_lock_busted_write_unlock,	.name		= "lock_busted"}; static DEFINE_SPINLOCK(torture_spinlock); static int torture_spin_lock_write_lock(void) __acquires(torture_spinlock){	spin_lock(&torture_spinlock);	return 0;} static void torture_spin_lock_write_delay(struct torture_random_state *trsp){	const unsigned long shortdelay_us = 2;	const unsigned long longdelay_us = 100; 	/* We want a short delay mostly to emulate likely code, and	 * we want a long delay occasionally to force massive contention.	 */	if (!(torture_random(trsp) %	      (nrealwriters_stress * 2000 * longdelay_us)))		mdelay(longdelay_us);	if (!(torture_random(trsp) %	      (nrealwriters_stress * 2 * shortdelay_us)))		udelay(shortdelay_us);#ifdef CONFIG_PREEMPT	if (!(torture_random(trsp) % (nrealwriters_stress * 20000)))		preempt_schedule();  /* Allow test to be preempted. */#endif} static void torture_spin_lock_write_unlock(void) __releases(torture_spinlock){	spin_unlock(&torture_spinlock);} static struct lock_torture_ops spin_lock_ops = {	.writelock	= torture_spin_lock_write_lock,	.write_delay	= torture_spin_lock_write_delay,	.writeunlock	= torture_spin_lock_write_unlock,	.name		= "spin_lock"}; static int torture_spin_lock_write_lock_irq(void)__acquires(torture_spinlock_irq){	unsigned long flags; 	spin_lock_irqsave(&torture_spinlock, flags);	cur_ops->flags = flags;	return 0;} static void torture_lock_spin_write_unlock_irq(void)__releases(torture_spinlock){	spin_unlock_irqrestore(&torture_spinlock, cur_ops->flags);} static struct lock_torture_ops spin_lock_irq_ops = {	.writelock	= torture_spin_lock_write_lock_irq,	.write_delay	= torture_spin_lock_write_delay,	.writeunlock	= torture_lock_spin_write_unlock_irq,	.name		= "spin_lock_irq"}; /* * Lock torture writer kthread.  Repeatedly acquires and releases * the lock, checking for duplicate acquisitions. */static int lock_torture_writer(void *arg){	struct lock_writer_stress_stats *lwsp = arg;	static DEFINE_TORTURE_RANDOM(rand); 	VERBOSE_TOROUT_STRING("lock_torture_writer task started");	set_user_nice(current, MAX_NICE); 	do {		if ((torture_random(&rand) & 0xfffff) == 0)			schedule_timeout_uninterruptible(1);		cur_ops->writelock();		if (WARN_ON_ONCE(lock_is_write_held))			lwsp->n_write_lock_fail++;		lock_is_write_held = 1;		lwsp->n_write_lock_acquired++;		cur_ops->write_delay(&rand);		lock_is_write_held = 0;		cur_ops->writeunlock();		stutter_wait("lock_torture_writer");	} while (!torture_must_stop());	torture_kthread_stopping("lock_torture_writer");	return 0;} /* * Create an lock-torture-statistics message in the specified buffer. */static void lock_torture_printk(char *page){	bool fail = 0;	int i;	long max = 0;	long min = lwsa[0].n_write_lock_acquired;	long long sum = 0; 	for (i = 0; i < nrealwriters_stress; i++) {		if (lwsa[i].n_write_lock_fail)			fail = true;		sum += lwsa[i].n_write_lock_acquired;		if (max < lwsa[i].n_write_lock_fail)			max = lwsa[i].n_write_lock_fail;		if (min > lwsa[i].n_write_lock_fail)			min = lwsa[i].n_write_lock_fail;	}	page += sprintf(page, "%s%s ", torture_type, TORTURE_FLAG);	page += sprintf(page,			"Writes:  Total: %lld  Max/Min: %ld/%ld %s  Fail: %d %s\n",			sum, max, min, max / 2 > min ? "???" : "",			fail, fail ? "!!!" : "");	if (fail)		atomic_inc(&n_lock_torture_errors);} /* * Print torture statistics.  Caller must ensure that there is only one * call to this function at a given time!!!  This is normally accomplished * by relying on the module system to only have one copy of the module * loaded, and then by giving the lock_torture_stats kthread full control * (or the init/cleanup functions when lock_torture_stats thread is not * running). */static void lock_torture_stats_print(void){	int size = nrealwriters_stress * 200 + 8192;	char *buf; 	buf = kmalloc(size, GFP_KERNEL);	if (!buf) {		pr_err("lock_torture_stats_print: Out of memory, need: %d",		       size);		return;	}	lock_torture_printk(buf);	pr_alert("%s", buf);	kfree(buf);} /* * Periodically prints torture statistics, if periodic statistics printing * was specified via the stat_interval module parameter. * * No need to worry about fullstop here, since this one doesn't reference * volatile state or register callbacks. */static int lock_torture_stats(void *arg){	VERBOSE_TOROUT_STRING("lock_torture_stats task started");	do {		schedule_timeout_interruptible(stat_interval * HZ);		lock_torture_stats_print();		torture_shutdown_absorb("lock_torture_stats");	} while (!torture_must_stop());	torture_kthread_stopping("lock_torture_stats");	return 0;} static inline voidlock_torture_print_module_parms(struct lock_torture_ops *cur_ops,				const char *tag){	pr_alert("%s" TORTURE_FLAG		 "--- %s: nwriters_stress=%d stat_interval=%d verbose=%d shuffle_interval=%d stutter=%d shutdown_secs=%d onoff_interval=%d onoff_holdoff=%d\n",		 torture_type, tag, nrealwriters_stress, stat_interval, verbose,		 shuffle_interval, stutter, shutdown_secs,		 onoff_interval, onoff_holdoff);} static void lock_torture_cleanup(void){	int i; 	if (torture_cleanup())		return; 	if (writer_tasks) {		for (i = 0; i < nrealwriters_stress; i++)			torture_stop_kthread(lock_torture_writer,					     writer_tasks[i]);		kfree(writer_tasks);		writer_tasks = NULL;	} 	torture_stop_kthread(lock_torture_stats, stats_task);	lock_torture_stats_print();  /* -After- the stats thread is stopped! */ 	if (atomic_read(&n_lock_torture_errors))		lock_torture_print_module_parms(cur_ops,						"End of test: FAILURE");	else if (torture_onoff_failures())		lock_torture_print_module_parms(cur_ops,						"End of test: LOCK_HOTPLUG");	else		lock_torture_print_module_parms(cur_ops,						"End of test: SUCCESS");} static int __init lock_torture_init(void){	int i;	int firsterr = 0;	static struct lock_torture_ops *torture_ops[] = {		&lock_busted_ops, &spin_lock_ops, &spin_lock_irq_ops,	}; 	if (!torture_init_begin(torture_type, verbose, &locktorture_runnable))		return -EBUSY; 	/* Process args and tell the world that the torturer is on the job. */	for (i = 0; i < ARRAY_SIZE(torture_ops); i++) {		cur_ops = torture_ops[i];		if (strcmp(torture_type, cur_ops->name) == 0)			break;	}	if (i == ARRAY_SIZE(torture_ops)) {		pr_alert("lock-torture: invalid torture type: \"%s\"\n",			 torture_type);		pr_alert("lock-torture types:");		for (i = 0; i < ARRAY_SIZE(torture_ops); i++)			pr_alert(" %s", torture_ops[i]->name);		pr_alert("\n");		torture_init_end();		return -EINVAL;	}	if (cur_ops->init)		cur_ops->init(); /* no "goto unwind" prior to this point!!! */ 	if (nwriters_stress >= 0)		nrealwriters_stress = nwriters_stress;	else		nrealwriters_stress = 2 * num_online_cpus();	lock_torture_print_module_parms(cur_ops, "Start of test"); 	/* Initialize the statistics so that each run gets its own numbers. */ 	lock_is_write_held = 0;	lwsa = kmalloc(sizeof(*lwsa) * nrealwriters_stress, GFP_KERNEL);	if (lwsa == NULL) {		VERBOSE_TOROUT_STRING("lwsa: Out of memory");		firsterr = -ENOMEM;		goto unwind;	}	for (i = 0; i < nrealwriters_stress; i++) {		lwsa[i].n_write_lock_fail = 0;		lwsa[i].n_write_lock_acquired = 0;	} 	/* Start up the kthreads. */ 	if (onoff_interval > 0) {		firsterr = torture_onoff_init(onoff_holdoff * HZ,					      onoff_interval * HZ);		if (firsterr)			goto unwind;	}	if (shuffle_interval > 0) {		firsterr = torture_shuffle_init(shuffle_interval);		if (firsterr)			goto unwind;	}	if (shutdown_secs > 0) {		firsterr = torture_shutdown_init(shutdown_secs,						 lock_torture_cleanup);		if (firsterr)			goto unwind;	}	if (stutter > 0) {		firsterr = torture_stutter_init(stutter);		if (firsterr)			goto unwind;	} 	writer_tasks = kzalloc(nrealwriters_stress * sizeof(writer_tasks[0]),			       GFP_KERNEL);	if (writer_tasks == NULL) {		VERBOSE_TOROUT_ERRSTRING("writer_tasks: Out of memory");		firsterr = -ENOMEM;		goto unwind;	}	for (i = 0; i < nrealwriters_stress; i++) {		firsterr = torture_create_kthread(lock_torture_writer, &lwsa[i],						  writer_tasks[i]);		if (firsterr)			goto unwind;	}	if (stat_interval > 0) {		firsterr = torture_create_kthread(lock_torture_stats, NULL,						  stats_task);		if (firsterr)			goto unwind;	}	torture_init_end();	return 0; unwind:	torture_init_end();	lock_torture_cleanup();	return firsterr;} module_init(lock_torture_init);module_exit(lock_torture_cleanup);