2 * Common functions for in-kernel torture tests.
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.
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.
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.
18 * Copyright (C) IBM Corporation, 2014
20 * Author: Paul E. McKenney <paulmck@us.ibm.com>
21 * Based on kernel/rcu/torture.c.
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>
49 MODULE_LICENSE("GPL");
50 MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com>");
52 int fullstop = FULLSTOP_RMMOD;
53 EXPORT_SYMBOL_GPL(fullstop);
54 DEFINE_MUTEX(fullstop_mutex);
55 EXPORT_SYMBOL_GPL(fullstop_mutex);
57 #define TORTURE_RANDOM_MULT 39916801 /* prime */
58 #define TORTURE_RANDOM_ADD 479001701 /* prime */
59 #define TORTURE_RANDOM_REFRESH 10000
62 * Crude but fast random-number generator. Uses a linear congruential
63 * generator, with occasional help from cpu_clock().
66 torture_random(struct torture_random_state *trsp)
68 if (--trsp->trs_count < 0) {
69 trsp->trs_state += (unsigned long)local_clock();
70 trsp->trs_count = TORTURE_RANDOM_REFRESH;
72 trsp->trs_state = trsp->trs_state * TORTURE_RANDOM_MULT +
74 return swahw32(trsp->trs_state);
76 EXPORT_SYMBOL_GPL(torture_random);
79 * Absorb kthreads into a kernel function that won't return, so that
80 * they won't ever access module text or data again.
82 void torture_shutdown_absorb(const char *title)
84 while (ACCESS_ONCE(fullstop) == FULLSTOP_SHUTDOWN) {
86 "torture thread %s parking due to system shutdown\n",
88 schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT);
91 EXPORT_SYMBOL_GPL(torture_shutdown_absorb);