1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * lib/debug_locks.c
4  *
5  * Generic place for common debugging facilities for various locks:
6  * spinlocks, rwlocks, mutexes and rwsems.
7  *
8  * Started by Ingo Molnar:
9  *
10  *  Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
11  */
12 #include <linux/rwsem.h>
13 #include <linux/mutex.h>
14 #include <linux/export.h>
15 #include <linux/spinlock.h>
16 #include <linux/debug_locks.h>
17 
18 /*
19  * We want to turn all lock-debugging facilities on/off at once,
20  * via a global flag. The reason is that once a single bug has been
21  * detected and reported, there might be cascade of followup bugs
22  * that would just muddy the log. So we report the first one and
23  * shut up after that.
24  */
25 int debug_locks __read_mostly = 1;
26 EXPORT_SYMBOL_GPL(debug_locks);
27 
28 /*
29  * The locking-testsuite uses <debug_locks_silent> to get a
30  * 'silent failure': nothing is printed to the console when
31  * a locking bug is detected.
32  */
33 int debug_locks_silent __read_mostly;
34 EXPORT_SYMBOL_GPL(debug_locks_silent);
35 
36 /*
37  * Generic 'turn off all lock debugging' function:
38  */
debug_locks_off(void)39 noinstr int debug_locks_off(void)
40 {
41 	if (debug_locks && __debug_locks_off()) {
42 		if (!debug_locks_silent) {
43 			console_verbose();
44 			return 1;
45 		}
46 	}
47 	return 0;
48 }
49 EXPORT_SYMBOL_GPL(debug_locks_off);
50