xref: /openbmc/linux/lib/debug_locks.c (revision 9ac8d3fb)
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/kernel.h>
12 #include <linux/rwsem.h>
13 #include <linux/mutex.h>
14 #include <linux/module.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 = 1;
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;
33 
34 /*
35  * Generic 'turn off all lock debugging' function:
36  */
37 int debug_locks_off(void)
38 {
39 	if (xchg(&debug_locks, 0)) {
40 		if (!debug_locks_silent) {
41 			oops_in_progress = 1;
42 			console_verbose();
43 			return 1;
44 		}
45 	}
46 	return 0;
47 }
48