lib/debug_locks.c

   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/module.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 = 1;
  25
  26 /*
  27  * The locking-testsuite uses <debug_locks_silent> to get a
  28  * 'silent failure': nothing is printed to the console when
  29  * a locking bug is detected.
  30  */
  31 int debug_locks_silent;
  32
  33 /*
  34  * Generic 'turn off all lock debugging' function:
  35  */
  36 int debug_locks_off(void)
  37 {
  38         if (xchg(&debug_locks, 0)) {
  39                 if (!debug_locks_silent) {
  40                         console_verbose();
  41                         return 1;
  42                 }
  43         }
  44         return 0;
  45 }