lib/debug_locks.c

   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  */
  39 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);