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       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                 :          0 : int debug_locks_off(void)
      40                 :            : {
      41   [ #  #  #  # ]:          0 :         if (debug_locks && __debug_locks_off()) {
      42         [ #  # ]:          0 :                 if (!debug_locks_silent) {
      43         [ #  # ]:          0 :                         console_verbose();
      44                 :          0 :                         return 1;
      45                 :            :                 }
      46                 :            :         }
      47                 :            :         return 0;
      48                 :            : }
      49                 :            : EXPORT_SYMBOL_GPL(debug_locks_off);