xref: /openbmc/linux/lib/debug_locks.c (revision ccb01374)
1 /*
2  * lib/debug_locks.c
3  *
4  * Generic place for common debugging facilities for various locks:
5  * spinlocks, rwlocks, mutexes and rwsems.
6  *
7  * Started by Ingo Molnar:
8  *
9  *  Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
10  */
11 #include <linux/rwsem.h>
12 #include <linux/mutex.h>
13 #include <linux/export.h>
14 #include <linux/spinlock.h>
15 #include <linux/debug_locks.h>
16 
17 /*
18  * We want to turn all lock-debugging facilities on/off at once,
19  * via a global flag. The reason is that once a single bug has been
20  * detected and reported, there might be cascade of followup bugs
21  * that would just muddy the log. So we report the first one and
22  * shut up after that.
23  */
24 int debug_locks __read_mostly = 1;
25 EXPORT_SYMBOL_GPL(debug_locks);
26 
27 /*
28  * The locking-testsuite uses <debug_locks_silent> to get a
29  * 'silent failure': nothing is printed to the console when
30  * a locking bug is detected.
31  */
32 int debug_locks_silent __read_mostly;
33 EXPORT_SYMBOL_GPL(debug_locks_silent);
34 
35 /*
36  * Generic 'turn off all lock debugging' function:
37  */
38 int debug_locks_off(void)
39 {
40 	if (debug_locks && __debug_locks_off()) {
41 		if (!debug_locks_silent) {
42 			console_verbose();
43 			return 1;
44 		}
45 	}
46 	return 0;
47 }
48 EXPORT_SYMBOL_GPL(debug_locks_off);
49